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Filter Paper (filter + paper)
Selected AbstractsA Novel Method for Air Drying Aloe Leaf Slices by Covering with Filter Papers as a Shrink-Proof LayerJOURNAL OF FOOD SCIENCE, Issue 9 2009S.A. Kim ABSTRACT:, To prevent the shrinkage of aloe vera slices during air drying, a method utilizing a shrink-proof layer was developed. The sample was configured of whole leaf aloe slices, where 1 side or both sides were covered with filter papers as shrink-proof layers. After air drying by varying the air temperature and the slice thickness, the drying characteristics, as well as several quality factors of the dried aloe vera leaf slices, were analyzed. In the simulation of the drying curves, the modified Page model showed the best fitness, representing a diffusion-controlled drying mechanism. Nonetheless, there was a trace of a constant-rate drying period in the samples dried by the method. Shrinkage was greatly reduced, and the rehydration ratios increased by approximately 50%. Scanning electron microscopic analysis revealed that the surface structure of original fibrous form was well sustained. FT-IR characteristics showed that the dried samples could sustain aloe polysaccharide acetylation. Furthermore, the functional properties of the dried slices including water holding capacity, swelling, and fat absorption capability were improved, and polysaccharide retention levels increased by 20% to 30%. Therefore, we concluded that application of shrink-proof layers on aloe slices provides a novel way to overcome the shrinkage problems commonly found in air drying, thereby improving their functional properties with less cost. Practical Application: This research article demonstrates a novel air drying method using shrink-proof layers to prevent the shrinkage of aloe slices. We analyzed extensively the characteristics of shrinkage mechanism and physical properties of aloe flesh gels in this drying system. We concluded that this method can be a beneficial means to retain the functional properties of dried aloe, and a potential alternative to freeze drying, which is still costly. [source] Carbon Powder Based Films on Traditional Solid Electrodes as an Alternative to Disposable ElectrodesELECTROANALYSIS, Issue 11 2006Bogdan Yosypchuk Abstract The covering of conventional solid electrode with a film using an ink containing a conductive powder and a polymer enables to broaden the potential window of the original solid electrode. A solid silver amalgam electrode covered with such a film exhibits a potential window from ,600,mV to +1400,mV vs. SCE reference electrode. The renewal of the film is fast and simple: the electrode can be simply wiped with a filter paper to remove the old film and immersed into an ink solution or 1,2,,L of this ink solution can be applied to the surface of the electrode with a micro dispenser to form a new film. Therefore, just the inexpensive film at the electrode surface is disposable and there is no need to dispose the whole, more expensive electrode. Moreover, when a suitable electrochemical pretreatment of the film electrode is applied, the same film can be used for reproducible measurements for several days. [source] Transformation of 2,4,6-trinitrotoluene in soil in the presence of the earthworm Eisenia andrei,ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 6 2000Agnès Y. Renoux Abstract The ability of the earthworm Eisenia andrei to metabolize 2,4,6-trinitrotoluene (TNT) was studied in experiments with TNT-spiked soils, dermal contact tests, and with an in vitro assay. Lethality of TNT in a forest sandy soil was first determined (14-d LC50 = 143 mg/kg). Then TNT at lethal and sublethal concentrations was applied to the same soil and was monitored along with its metabolites in extracts of soil and earthworm tissue for up to 14 d postapplication. High performance liquid chromatography-ultra violet analyses indicated that TNT was transformed in the presence of E. andrei by a reductive pathway to 2-amino-4,6-dinitrotoluene (2-ADNT), 4-amino-2,6-dinitrotoluene (4-ADNT), 2,4-diamino-6-nitrotoluene (2,4-DANT), and traces of 2,6-di-amino-4-nitrotoluene (2,6-DANT) in earthworm tissues. This transformation could be explained by either a metabolic mechanism within the earthworm or by the enhancement of an earthworm-associated microbial activity or both. The TNT concentrations decreased from the spiked soils. However, the monoamino-dinitrotoluene (2-ADNT and 4-ADNT) concentrations increased with exposure duration and were dependent on the initial TNT soil concentrations. This was also observed to a lesser extent in the TNT-spiked soils with no earthworms present. The biotransformation of TNT into 2-ADNT, 4-ADNT, and 2,4-DANT and the presence of these metabolites in E. andrei after dermal contact on TNT-spiked filter paper showed that dermal uptake can be a significant exposure route for TNT. In vitro experiments showed that earthworm homogenate could metabolize TNT and form 2-ADNT and 4-ADNT at room temperature and at 37°C. This effect was inhibited by heat inactivation prior to incubation or by incubation at 4°C, suggesting that the biotransformation of TNT in the presence of E. andrei may be enzymatic in nature. [source] Olfactory information saves venom during prey-capture of the hunting spider Cupiennius salei (Araneae: Ctenidae)FUNCTIONAL ECOLOGY, Issue 2 2006S. HOSTETTLER Summary 1The Neotropical spider Cupiennius salei Keyserling (Ctenidae) selects prey in a manner consistent with the amount of venom available in its venom glands. It distinguishes the venom sensitivity of different prey species, and uses its venom economically (according to the venom-optimization hypothesis). 2A prey-choice experiment was performed to test whether spiders use olfactory cues to detect prey and select prey items that are appropriate for their amount of available venom. 3The spider could choose between two similar prey dummies made of agar. We added the odour of two prey species, either by adding minced insects to an agar block or by offering it on filter paper which had previously been exposed to the living prey. Cupiennius salei spiders had either full or emptied venom glands. 4Two insects of distinctive venom sensitivity, but high acceptance, were tested: a sensitive cricket and a less sensitive cockroach. 5Using video surveillance, we found an attraction effect of prey odour in the prey-capture behaviour of C. salei. Spiders preferred agar pieces with minced insects or insect odour on filter paper over non-smelling items. Reaction frequency and attack rates were equal for spiders with full venom glands if they had to choose between cricket and cockroach odour. When the venom glands were empty, however, C. salei significantly preferred the venom-sensitive cricket over the venom-insensitive cockroach. 6We showed for the first time that C. salei uses its olfactory sense to detect prey items, and distinguishes between prey species with low and high sensitivity to spider venom. This study supports the venom-optimization hypothesis. [source] Evaluation of the use of dried spots and of different storage conditions of plasma for HIV-1 RNA quantificationHIV MEDICINE, Issue 6 2007B Amellal Objectives The aim of the study was to evaluate the use of dried plasma spots to determine HIV-1 RNA viral loads. Methods The viral loads of 30 liquid plasma samples were compared with those of corresponding dried plasma spots on filter paper (DPS-FP) and in tubes (DPS-T), both of which were left for 7 days at 22°C. Also, 10 liquid plasma samples with detectable viral load were stored at 4, 22 or 37°C for 7 days and five further liquid plasma samples were air-dried for up to 54 h to assess the effects of temperature and the drying step on HIV-1 viral load. Results The viral loads of the 30 liquid plasma samples correlated significantly with those of the paired dried spots DPS-FP and DPS-T, but with median losses of 0.64 and 0.69 log10 HIV-1 RNA copies/mL, respectively, and a limit of detection of 3 log10 copies/mL. The 10 liquid plasma samples stored for 1 week at 37°C showed a weaker correlation and had a significantly reduced median viral load (,0.92 log10; P=0.005) when compared with the viral load of the matched plasma stored at ,80°C. Most of the loss happened during the drying step. Conclusions Reliable measurement of HIV-1 RNA viral load requires good plasma storage conditions. HIV RNA stability was affected by desiccation and 1 week of storage at 37°C. However, our findings suggest that liquid plasma can be kept at 4 or 22°C for a week with no effect on viral load. [source] Multiple displacement amplification to create a long-lasting source of DNA for genetic studies,HUMAN MUTATION, Issue 7 2006Lovisa Lovmar Abstract In many situations there may not be sufficient DNA collected from patient or population cohorts to meet the requirements of genome-wide analysis of SNPs, genomic copy number polymorphisms, or acquired copy number alternations. When the amount of available DNA for genotype analysis is limited, high performance whole-genome amplification (WGA) represents a new development in genetic analysis. It is especially useful for analysis of DNA extracted from stored histology slides, tissue samples, buccal swabs, or blood stains collected on filter paper. The multiple displacement amplification (MDA) method, which relies on isothermal amplification using the DNA polymerase of the bacteriophage ,29, is a recently developed technique for high performance WGA. This review addresses new trends in the technical performance of MDA and its applications to genetic analyses. The main challenge of WGA methods is to obtain balanced and faithful replication of all chromosomal regions without the loss of or preferential amplification of any genomic loci or allele. In multiple comparisons to other WGA methods, MDA appears to be most reliable for genotyping, with the most favorable call rates, best genomic coverage, and lowest amplification bias. Hum Mutat 27(7), 603,614, 2006. © 2006 Wiley-Liss, Inc. [source] Effect of five diatomaceous earth formulations against Tribolium castaneum (Coleoptera: Tenebrionidae), Oryzaephilus surinamensis (Coleoptera: Silvanidae) and Rhyzopertha dominica (Coleoptera: Bostrychidae)INSECT SCIENCE, Issue 5 2007MASUMEH ZIAEE Abstract Laboratory bioassays were conducted to determine the effect of food source on the survival of Tribolium castaneum Herbst, Oryzaephilus surinamensis L. and Rhyzopertha dominica F., after exposure to five diatomaceous earth (DE) formulations: Protect-It®, Insecto®, Perma-GuardÔ, Dryacide® and SilicoSec®. Adults of these species were exposed to DEs at the rate of 0.5 mg/cm2 for 1 day on filter paper inside plastic Petri dishes. After exposure, the initial mortality was counted and live individuals of the three species were held for a week in glass vials containing 50 mg wheat flour, rice and whole wheat, respectively. In the second experiment, after 1 day exposure to DEs, beetles were transferred to Petri dishes without food and held for a week to determine if the presence of food source would decrease the mortality of beetles. Experiments were carried out at 27°C and 55% RH in the dark. The initial mortality in both of the experiments reached 100% for the three species exposed to Protect-It® and in the case of R. dominica and O. surinamensis exposed to Dryacide®. In contrast, low level of mortality (< 10%) was observed for T. castaneum exposed to Perma-GuardÔ and Insecto®. The mortality after the post-treatment period on food was decreased for the three species exposed to Perma-GuardÔ and in the case of T. castaneum and R. dominica exposed to Insecto® and SilicoSec®. Adults of O. surinamensis were the most susceptible followed by R. dominica and 100% adult mortality was obtained, whereas T. castaneum were the least susceptible beetles to DEs. Protect-It® and Dryacide® were the most efficient DE formulations and can be used effectively in a stored grain integrated pest management program. [source] Baseline susceptibility of western corn rootworm (Coleoptera: Chrysomelidae) to clothianidinJOURNAL OF APPLIED ENTOMOLOGY, Issue 4 2007L. C. Magalhaes Abstract:, Western corn rootworm, Diabrotica virgifera virgifera LeConte, neonate susceptibility to clothianidin, a contact and systemic neonicotinoid insecticide, was determined from both laboratory and field-collected populations. Neonates were exposed to filter paper treated with increasing clothianidin concentrations and mortality was evaluated after 24 h. Additionally, two populations were exposed to an artificial diet which was surface treated with clothianidin. Although larvae were five- to six-fold more sensitive to treated diet, results with treated filter paper were more reliable in terms of control mortality and required much less manipulation of rootworm larvae. Therefore, initial baseline comparisons were conducted using the filter paper assays. The variation among populations exposed to treated filter paper was generally low, 4.4-fold among laboratory populations tested; however, there was a 14.5-fold difference in susceptibility among all populations tested. In general, clothianidin was very toxic to rootworm neonates, with LC50 values ranging from 1.5 to 21.9 ng/cm2. These results indicate the practicability and sensitivity of the paper filter disc assay to establish baseline susceptibility levels, which is an essential first step in resistance management. A baseline response provides a reference for tracking shifts in susceptibility following commercialization of a control agent so that early changes in susceptibility can be detected. [source] Oviposition deterrence of shoots and essential oils of Minthostachys spp. (Lamiaceae) against the potato tuber mothJOURNAL OF APPLIED ENTOMOLOGY, Issue 2 2007P. C. Guerra Abstract:, The potato tuber moth is a noxious pest of potato in stores, where the use of repellent plants is an environmentally sound alternative to the application of chemical pesticides. We evaluated the protective effect of native Minthostachys species (Lamiaceae) against tuber infestation by the potato tuber moth in a rustic store in Cusco, Perú. We covered potato tubers with dried shoots of Minthostachys spicata and Minthostachys glabrescens and compared tuber damage with a control treatment of maize straw. We also conducted a no-choice oviposition bioassay in the laboratory, testing the oviposition deterrence of essential oils of M. spicata, M. glabrescens and Minthostachys mollis at natural concentrations. We recorded the number of eggs laid by mated moths on filter paper treated with essential oils of each of the three species and on two control treatments: hexane and untreated blank. Finally, we tested for differences in oviposition deterrence among five full-sib families of potato tuber moth raised under identical conditions. We found that dried, chopped leaves and flowers of Minthostachys species reduced the percentage of tuber damage in stores in comparison with the control (5% vs. 12%), but no difference in protection was found between species. Essential oils at natural concentrations deterred moth oviposition, reducing the number of eggs laid by about 80% compared with the control treatments; again, there were no significant differences between Minthostachys species. Finally, whereas we detected among-family variation in oviposition on filter papers treated with essential oils, no difference was found in the number of eggs laid on control substrates. Therefore, there was genetic variation for oviposition deterrence in the potato tuber moth and resistance to repellent plants might evolve thereafter. [source] Sterilization system for air purifier by combining ultraviolet light emitting diodes with TiO2JOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 10 2009Xiaohui Huang Abstract BACKGROUND: Ultraviolet light emitting diodes (UV LEDs) were used as a light source in TiO2 photocatalysis because of their many advantages, such as, long life, safety, low pollution, etc. In this experiment, a light source panel was successfully fabricated with UV LEDs, the light intensities of which were relatively uniform. RESULTS: The sterilization process comprised two steps. First, an aerosol was blocked by high efficient particulate air (HEPA) filter paper coated with TiO2 photocatalyst. Second, Staphylococcus aureus in the aerosol decreased gradually in the photocatalysis process of UV LED/TiO2. After 52 h irradiation all the S. aureus were killed. CONCLUSION: The UV LED light source panel had a larger surface for irradiation than a mercury lamp. Thus, its sterilization efficiency was much better than that of traditional methods. The feasibility of UV LED/TiO2 for photocatalysis was proved. Copyright © 2009 Society of Chemical Industry [source] Effect of interleukin-1 gene polymorphism in a periodontally healthy Hispanic population treated with mucogingival surgeryJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 2 2002Raul G. Caffesse Abstract Objectives: A genetic test for susceptibility of periodontal disease has been introduced. A positive test indicates a risk factor for more severe periodontal destruction. The prevalence of genotype positive subjects has been reported around 30%. In a Mexican population, we have found a 26% prevalence of genotype positive individuals. Few studies have reported the response to therapy in these individuals. The purpose of this study was to assess the response to mucogingival surgery in an otherwise periodontally healthy Hispanic population. Materials and methods: 22 subjects (7 male and 15 female) with a mean age of 45 years participated. They were treated 3 years prior for the treatment of Types I and II recession defects using connective tissue grafts. No other active periodontal treatment was required, except for preventive maintenance. A full-mouth clinical evaluation was performed which included assessment of gingival inflammation and measurements of probing pocket depth and clinical attachment levels. Mean values per patient were determined. A finger stick blood sample was collected using specially provided DNA filter paper, let dried, and mailed for processing. Results: Results indicated that 5 out of the 22 subjects were genotype positive. The genotype positive subjects presented the following values: GI 1.13±0.17, PPD 2.48±0.46, and CAL 3.38±0.66. The values for the genotype negative subjects were GI 1.06±0.14, PPD 2.38±0.31 and CAL 3.11±0.53. No statistical significant differences were found when both groups were compared (p>0.05). Furthermore, the treatment of the localized recessions was effective and provided similar amount of coverage in genotype positive and negative subjects. However, more genotype negative subjects showed complete coverage of the recession than genotype positive individuals. Conclusions: Within the limits of this study it is concluded that (1) periodontal health can be maintained with proper preventive maintenance irrespective of the genotype present, (2) the mean response to mucogingival surgery to cover localized gingival recessions is similar irrespective of the IL-1 periodontal genotype, however, full coverage is achieved more frequently in genotype negative subjects. Zusammenfassung Ziele: Es wurde ein Gentest für die Anfälligkeit bezüglich einer Parodontalerkrankung eingeführt. Ein positiver Test ist ein Zeichen für einen Risikofaktor für eine stärkere parodontale Destruktion. Die Prävalenz von genotyp-positiven Personen wurde mit etwa 30% angegeben. In einer mexikanischen Population haben wir eine Prävalenz von 26% von genotyp-positiven Individuen vorgefunden. Nur wenige Studien haben bei diesen Patienten über die Reaktion auf die Therapie berichtet. Der Zweck dieser Studie war es die Heilung nach mukogingivaler Chirurgie in einer im Übrigen parodontal gesunden Population mit spanischen Abstammung. Material und Methode: 22 Patienten (7 Männer und 15 Frauen) mit einem Durchschnittsalter von 45 Jahren nahmen an der Studie teil. Sie wurden vor 3 Jahren zur Deckung einer Rezession von Typ I oder II mit einem Bindegewebetransplantat behandelt. Es war keine weitere parodontale Behandlung außer präventiven Erhaltungstherapie notwendig. Es wurde eine vollständige klinische Untersuchung des Gebisses durchgeführt, die die Bestimmung der gingivalen Etnzündung, sowie die Messung der Sondierungstiefe und des klinischen Attachmentniveaus beinhaltete. Es wurden für jeden Patienten die Mittelwerte bestimmt. Eine Blutprobe von der Fingerbeere wurde entnommen, auf ein specielles DNA-Filterpapier aufgetragen, getrocknet und zur Weiterverarbeitung versendet. Ergebnisse: Die Ergebnisse zeigten, dass 5 von 22 Patienten genotyp-positiven waren. Die genotyp-positiven Patienten wiesen folgende Werte auf: GI 1.13±0.17, PPD 2.48±0.46 und CAL 3.38±0.66. Die Werte für die genotyp-negativen Patienten betrugen: GI 1.06±0.14, PPD 2.38±0.31 und CAL 3.11±0.53. Beim Vergleich beider Gruppen ergaben sich keine statistisch signifikanten Unterschiede (p>0.05). Des weiteren war die Behandlung der lokalisierten Rezession effektiv und lieferte bei genotyp-positiven und genotyp-negativen Patienten einen ähnlichen Anteil an Wurzeldeckung. Jedoch zeigten mehr genotyp-negative Patienten eine vollständige Rezessionsdeckung als genotyp-positive Patienten. Schlussfolgerungen: Mit den Einschränkungen dieser Studie kann die Schlussfolgerung gezogen werden, dass (1) unabhängig vom vorliegenden Genotyp mit geeigneten präventiven Maßnahmen die parodontale Gesundheit erhalten werden kann und (2) dass unabhängig vom IL-1-Genotyp, die durchschnittliche Reaktion auf die mukogingivale Chirurgie zur Deckung von lokalisierten Gingivarezessionen ähnlich ist. Jedoch wird eine vollständige Deckung häufiger bei genotyp-negativen Patienten erreicht. Résumé But: Un test génétique pour la suscpetibilitéà la maladie parodontale est présenté. Un test positif indique un facteur de risque pour une destruction parodontale plus sévère. La fréquence globale de sujets positifs au génotype semblerait être de 30%. Dans une population mexicaine, une fréquence globale de 26% d'individus positifs pour le génotype a été trouvée. Peu d'études ont apporté la réponse au traitement chez ces individus. Le but de cette investigation a été de mesurer la réponse de la chirurgie muco-gingivale dans une population hispanique parodontalement saine. Matériaux et méthodes: 7 hommes et 15 femmes d'un âge moyen de 45 ans y ont participé. Ils avaient été traités 3 ans auparavant pour des lésions de récession de type I et II en utilisant des greffes de tissu conjonctif. Aucun autre traitement parodontal actif n'avait été requis, sauf pour la maintenance. Une évaluation clinique de toute la bouche a été effectuée comprenant l'estimation de l'inflammation gingivale et les measures de la profondeur de poche au sondage et des niveaux d'attache clinique. Les valeurs moyennes par patient ont été déterminées. Un échantillon sanguin par piqûre du doigt a été récolté en utilisant un papier filtre ADN, qui fût séché et envoyé pour analyse. Résultats: Les résultats ont indiqué que 5 des 22 sujets étaient génotype positif. Ces sujets présentaient les valeurs suivantes: GI 1.13±0.17, PPD 2.48±0.46 mm et CAL 3.38±0.66 mm. Les valeurs chez les sujets génotype négatif étaient: GI 1.06±0.14, PPD 2.38±0.31 mm et CAL 3.11±0.53 mm. Aucune différence statistiquement significative n'a été trouvée lorsque les deux groupes ont été comparés. De plus le traitement des récessions locales était effectif et apportait une quantité semblable de recouvrement chez les deux types de sujets. Cependant davantage de sujets génotype négatif bénéficiaient d'un recouvrement complet de la récession. Conclusions: Dans les limites d l'étude présente: (1) la santé parodontale peut être maintenue avec des mesures préventives quelque soit le génotype présent, (2) la réponse moyenne de la chirurgie muco-gingivale pour recouvrir des récessions gingivales locales est semblable quelque soit le génotype parodontal IL-1, bien qu'un recouvrement complet est plus souvent réalisé chez les sujets génotype négatif. [source] Thiopurine S -methyltransferase (TPMT) genetic polymorphisms in Mexican newbornsJOURNAL OF CLINICAL PHARMACY & THERAPEUTICS, Issue 6 2009A. González-del Angel MD Abstract Background:, Thiopurine S -methyltransferase (TPMT) is involved in the toxicity and therapeutic efficacy of thiopurine drugs, and its gene exhibits genetic polymorphisms that differ across diverse populations. Four TPMT polymorphisms (TPMT*2, *3A, *3B and *3C) account for 80,95% of alleles that cause reduced enzyme activity. To date, only a single study in the Mexican population involving 108 individuals has been performed, but the regional and ethnic origin of this population was not described. Accordingly, information about the TPMT polymorphism in the Mexican population is limited. Objective:, To determine the TPMT allele and genotype frequencies in a sample of newborns from Mexico City. Methods:, Three hundred and sixty DNA samples from unrelated, anonymous individuals were obtained from dried blood spots collected on filter paper as part of the Newborn Screening National Program. Allele-specific polymerase chain reaction for the TPMT*2 allele and PCR restriction fragment length polymorphism for TPMT*3A, TPMT*3B, TPMT*3C alleles were used to determine the respective allelic and genotypic frequencies. Results and Discussion:, Of 720 TPMT alleles analysed, 49 (6·81%) were deficiency alleles. The most common deficiency allele was TPMT*3A (5·69%), followed by TPMT*3C (0·56%), TPMT*3B (0·28%) and TPMT*2 (0·28%). Fourty-five newborns were heterozygous for one mutant allele (12·5%) and two showed a genotype with two deficiency alleles (0·56%). Despite its unique ethnic composition, our Mexican population exhibited variant allele frequencies that were similar to some Caucasian populations. Conclusion:, Our data suggest that approximately 1 in 180 persons born in Mexico City might have low or undetectable TPMT enzyme activity, a frequency that, overall, is somewhat higher than that reported for Caucasian populations generally (1 in 300). [source] The Use of Hemastix® and the Subsequent Lack of DNA Recovery Using the Promega DNA IQTM SystemJOURNAL OF FORENSIC SCIENCES, Issue 6 2009Hiron Poon M.Sc. Abstract:, Following implementation of our automated process incorporating the Promega DNA IQTM system as a DNA extraction method, a large number of blood-containing exhibits failed to produce DNA. These exhibits had been tested with the Hemastix® reagent strip, commonly used by police investigators and forensic laboratories as a screening test for blood. Some exhibits were even tainted green following transfer of the presumptive test reagents onto the samples. A series of experiments were carried out to examine the effect of the Hemastix® chemistries on the DNA IQTM system. Our results indicate that one or more chemicals imbedded in the Hemastix® reagent strip severely reduce the ability to recover DNA from any suspected stain using the DNA IQTM magnetic bead technology. The 3,3,,5,5,-tetramethylbenzidine (TMB) used as the reporting dye appears to interact with the magnetic beads to prevent DNA recovery. Hydrogen peroxide does not seem to be involved. The Hemastix® chemistries do not interfere in any way with DNA extraction performed using phenol-chloroform. The incompatibility of the Hemastix® chemistries on the DNA IQTM system forced us to adopt an indirect approach using filter paper to carry out the presumptive test. [source] Seroprevalence of hepatitis A virus antibodies in Turkish and Moroccan children in Rotterdam,JOURNAL OF MEDICAL VIROLOGY, Issue 2 2004J.H. Richardus Abstract Seasonal fluctuations in hepatitis A have been observed in the Netherlands related to Turkish and Moroccan children after visiting their home countries. This study determined the prevalence and associated factors of hepatitis A virus (HAV) antibodies in Turkish and Moroccan children in Rotterdam. A random sample was taken of children in Rotterdam, aged 5,16 years, of Turkish and Moroccan origin, together with a random sample of native Dutch children aged 5,7 and 14,16 years. Blood was collected by finger prick on filter paper. IgG and IgM anti-HAV was detected by an enzyme-linked immunoassay (EIA). The 319 Turkish, 329 Moroccan, and 248 native Dutch children participated in the study. In Turkish children, IgG anti-HAV increased from 2.2% to 22.2% over the age groups. In Moroccan children, IgG anti-HAV increased from 10.2% to 57.7%. In native Dutch children, 0.8% had IgG anti-HAV in the youngest and 3.1% in the oldest age group. The percentage IgG-positive also having IgM anti-HAV was 21% in Turkish, and 41% in Moroccan children. No IgG-positive native Dutch children had IgM anti-HAV. The prevalence of IgG anti-HAV was associated with increased age, being Moroccan, longer stay in the country of origin before migrating to the Netherlands, and known contact to HAV. The majority of Turkish and Moroccan children aged 4,16 years in Rotterdam are not protected against HAV, but do have a high risk of becoming infected while visiting their native country. Active vaccination against HAV of these children is indicated, with as primary aim their own protection. Prevention of HAV-transmission in the general community should be seen as a secondary benefit. In addition, possible Dutch contacts of nonvaccinated Turkish and Moroccan children, such as day care workers and teachers, should also be vaccinated against HAV. J. Med. Virol. 72:197,202, 2004. © 2004 Wiley-Liss, Inc. [source] Technique for visual demonstration of germinating arbuscular mycorrhizal spores and their multiplication in potsJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 5 2007Jitendra Panwar Abstract We describe a simple technique for the germination of arbuscular mycorrhizal (AM),fungal spores and their multiplication in pots. Glomus fasciculatum, G. mosseae, and Gigaspora margarita were used. A single wheat seedling was tied to a glass slide, previously covered with filter paper with the help of thread. One single surface-sterilized AM-fungal spore was placed on the middle portion of the root of the wheat seedling using a sterilized syringe. The slide was placed vertically in a 100,mL glass beaker filled with 25,mL of root exudates,water (1:4, v/v) solution, which was collected by growing twenty wheat seedlings in a 150,mL beaker filled with 100,mL sterilized distilled water for 7 d. The slide was observed daily using a compound microscope to follow the time course of germination. In this technique, the spore is directly in contact with the host root, and a visualization of spore germination, hyphal development, and appressorium formation is possible without disrupting fungal growth or the establishment of the symbiosis. The method allows to document the germination events and to assess hyphal-elongation rates by photographing the same spore on consecutive days. The inoculated seedling was used to initiate single-spore multiplication in a sterilized (autoclave on 3 alternate days at 120°C for 120,min at 1.05,kg,cm,2 pressure) potted sandy soil (150,mL volume) into which the slide with the inoculated seedling was inserted carefully through a previously made slit. The wheat seedlings in all pots (4 treatments and 15 replications) became colonized by mycorrhiza, confirming that the establishment of the AM-fungal symbiosis is highly reproducible. Our technique permits the relatively undisturbed growth of the symbiotic partners, the visualization of germinating AM-fungal spores, and their multiplication in pots. This simple and low-cost method facilitates the production of pure lines of AM fungi from single spores, allowing for the study of intraspecific variation and potentiality for cytological, biochemical, physiological, and taxonomical studies. [source] Breeding of Pleurotus florida (oyster mushroom) for phenotypic pigmentation and high yield potentialJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 15 2008Jatinder Kaur Abstract BACKGROUND: Cross-hybridisation is a technique for exchange of genetic material between two compatible nuclei to develop a recombinant genome with a probable expression for a desirable trait. This technique as an example of classical genetics has been applied in a heterothallic bifactorial/tetrapolar fungus Pleurotus florida. It has worked successfully during this study in a small number of experiments. RESULTS: Fruit bodies from the Pleurotus florida PAU-5 were allowed to shed their basidiospores on filter paper under aseptic conditions. Forty-nine monokaryons were isolated from three spore prints, namely Ja, Jb and K. Three hundred and fifty-six crosses were laid to result in five compatible reactions (PFJ4, PFJ9, PFJ11, PFJ13 and PFJ14). The fruit bodies of the hybrid dikaryon PFJ4 were found to show grey pigmentation. The hybrid dikaryons PFJ11 and PFJ14 grew faster in wheat straw substrate to take 39 and 41 days, respectively, for complete mycelial impregnation as compared to the parent, PAU-5 (48 days). The dikaryon PFJ11 out-yielded the parent by giving 34.2% biological efficiency compared to 29.8% for the parent. CONCLUSION: Through cross-hybridisation various changes at the genetic level are possible, showing altered phenotypic expression of the characters, such as change in fruiting efficiency and variability in fruit body characteristics (e.g., pileus shape and pigmentation). This technique can also be applied to other crops to improve their yield potential and bring about desirable phenotypic changes. Copyright © 2008 Society of Chemical Industry [source] Application of functional group modified substrate in room-temperature phosphorescence, I,, -cyclodextrin modified paper substrate for enrichment and determination of fluorene and acenaphtheneLUMINESCENCE: THE JOURNAL OF BIOLOGICAL AND CHEMICAL LUMINESCENCE, Issue 4-5 2005Ruohua Zhu Abstract A novel method for the determination of fluorene and acenaphthene on solid phase extraction,room-temperature phosphorescence (SPE,RTP) was studied. , -cyclodextrin (, -CD) was chemically bonded onto chromatography paper by reaction with epichorohydrin in an ultrasonic bath. The RTP signal of fluorene and acenaphthene included on the , -CD-modified paper was increased more than 10 times compared with non-modified filter paper, indicating the formation of the inclusion complex. The conditions for the of RTP of compounds were studied in detail. The linear ranges of fluorene and acenaphthene concentrations to the RTP intensity were over two orders of magnitude (8.0 × 10,7,4.0 × 10,5 mol/L for fluorene) with a correlation coefficient of 0.999. The concentration limits of detection for fluorene and acenaphthene were 1.11 × 10,8 mol/L and 3.8 × 10,7 mo/L, respectively. When the sampling volume was 10 µL, the absolute LODs for fluorene and acenaphthene were 18.4 pg/spot and 0.58 ng/spot, respectively. The modified filter paper was used for solid phase extraction (SPE) and the retention behaviour of fluorene and acenaphthene was examined. The enrichment efficiency of the analytes was higher than 100-fold. The SPE,RTP coupling technique was applied directly to the determination of fluorene and acenaphthnene in environmental water samples. Copyright © 2005 John Wiley & Sons, Ltd. [source] Application of functional group modified substrate in room temperature phosphorescence, II,heavy atom-chelated filter paper for selective determination of , -naphthalene acetic acidLUMINESCENCE: THE JOURNAL OF BIOLOGICAL AND CHEMICAL LUMINESCENCE, Issue 4-5 2005Ruohua Zhu Abstract Heavy atom-chelated filter paper was synthesized and used as the substrate for room-temperature phosphorescence (RTP). The synthesis conditions for chelated paper were studied. The Pb-chelated filter paper could selectively induce the RTP of , -naphthalene acetic acid (, -NAA). The excitation and emission wavelengths of RTP of , -NAA were 300 nm and 521 nm, respectively. The concentration of , -NAA was linear with the RTP intensity in the range 2 × 10,6,6 × 10,4 mol/L (correlation coefficient, 0.9999). The concentration detection limit was 1.35 × 10,7 mol/L and the absolute detection limit was 0.25 ng/spot. The RSD (n = 10) was 1.7%. The method was applied to the analysis of water and vegetable samples with satisfactory results. Because the heavy atom was directly chelated onto the filter paper, the heavy-atom effect on the RTP of NAA was further increased and the analysis procedure was simple, fast and economical. Copyright © 2005 John Wiley & Sons, Ltd. [source] Glutamic acid decarboxylase and IA-2 autoantibodies in type 1 diabetes: comparing sample substrates for autoantibody determinationsPEDIATRIC DIABETES, Issue 1 2000C Wasserfall Large-scale programs designed to assess risk for type 1 diabetes through serologic assessment of autoantibodies to recombinant ,-cell autoantigens are hampered by several limitations, including the methods for sample collection and assay performance, as well as the volume required for autoantibody determinations. The present study was designed to develop a low sample-volume, primary screening method for autoantibody detection of high specificity and sensitivity, and to determine the feasibility of dried blood spots collected on filter paper in serving as vehicles for such determinations. Autoantibodies to glutamic acid decarboxylase (GAD) and ICA512bdc (IA-2), both individually and in combination, were determined in persons with type 1 diabetes, healthy controls, or individuals with other autoimmune disorders. Autoantibody results for serum, plasma, and dried blood spots were compared. GAD, IA-2, and combined GAD/IA-2 autoantibodies were concordant in their measurement from minimal volumes of serum, plasma, and whole blood extracted from dried filter paper. The autoantibody levels from the dried blood spots were, however, lower than corresponding serum samples, and, as currently designed, failed to detect low-titer autoantibodies. Despite this limitation, screening for diabetes risk can be performed using small volumes of whole blood, serum, or plasma collected onto filter paper. These methodological improvements should simplify matters, reduce costs, and increase the efficacy of screening programs for type 1 diabetes. Further development of better substrates/methods for blood-specimen collection seems necessary to exploit the full potential of this and other autoantibody measurement strategies for screening large populations. [source] Original Article: Long-term stability of thyroid hormones and DNA in blood spots kept under varying storage conditionsPEDIATRICS INTERNATIONAL, Issue 4 2010Asmahan A. EL Ezzi Abstract Background:, Congenital hypothyroidism is screened using blood spotted on filter paper that may be transported from remote areas to central testing facilities. However, storage conditions and transportation may affect sample quality. Methods:, We examined long-term stability of thyroid-stimulating hormone (TSH) and thyroxin (TT4) in blood spotted on filter paper, which was stored at room temperature (RT), 4°C and ,20°C under continuous or intermittent power supply (six hours on and six hours off around the clock.) Hormone levels in the discs were measured periodically for up to ten years. Extraction of DNA from blood spots and polymerase chain reaction were performed. Results:, Our results showed that TT4 was stable for up to 6.1, 5.34 and 5.16 years when stored at ,20°C, 4°C and RT, respectively. TSH was stable for up to 2.7 years at RT, and for up to 6.5 and 4.1 years when stored at ,20°C and 4°C, respectively, under continuous power supply. However, under intermittent power supply, TSH was stable for up to 3.8 and 2.5 years when stored at 4°C and ,20°C, respectively. Mitochondrial cytochrome oxidase and sex-determining region of Y chromosome genes were successfully amplified from DNA extracted from the blood spots. Conclusion:, Our data indicate that TT4 and TSH are most stable in blood spots stored at ,20°C under continuous power supply. However, they can be stored at RT or at 4°C and ,20°C under interrupted power supply for at least 2.5 years. Moreover, the DNA extracted from the blood spots was intact and suitable for genetic studies. [source] Acaricidal properties of piperazine and its derivatives against house-dust and stored-food mitesPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 6 2009Chi-Hoon Lee Abstract BACKGROUND: Piperazine derivatives possess pharmacological properties, yet the acaricidal activity of these compounds has not been investigated. This study was conducted to evaluate the colour alteration and acaricidal activity of piperazine derivatives against Dermatophagoides spp. and Tyrophagus putrescentiae (Schrank) using filter paper and fumigant methods. RESULTS: In a fumigant bioassay, 1-phenylpiperazine (7.83 µg cm,2) against D. farinae (Hughes) was found to be 4.7 times more toxic than DEET (36.84 µg cm,2), followed by benzyl benzoate (9.72 µg cm,2), piperazine (11.41 µg cm,2), 1-ethoxycarbonylpiperazine (20.14 µg cm,2) and 1-(2-methoxyphenyl)piperazine (22.14 µg cm,2). In a filter paper bioassay, 1-(2-methoxyphenyl)piperazine (3.65 µg cm,2) was 5.7 times more toxic than DEET (20.64 µg cm,2), followed by 1-ethoxycarbonylpiperazine (4.02 µg cm,2), 1-phenylpiperazine (4.75 µg cm,2), benzyl benzoate (7.83 µg cm,2) and piperazine (10.59 µg cm,2). Similar results have been exhibited with piperazine derivatives against D. pteronyssinus (Troussart). However, no activity against T. putrescentiae was observed for piperazine derivatives, except for piperazine. CONCLUSIONS: These results indicate that piperazine derivatives may be suitable as vapour-phase acaricide fumigants owing to their high volatility, acaricidal activity and safety. 1-Phenylpiperazine was found to be an excellent mite indicator based on the colour change it induced. Taken together, these findings indicate that piperazine derivatives may be used to replace existing problematical acaricides owing to their activity and ability to act as a mite indicator. Copyright © 2009 Society of Chemical Industry [source] Enzyme immunoassay for total immunoglobulin E in dried blood spotsAMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 3 2007Susan Tanner Elevated circulating levels of total immunoglobulin E (IgE) are associated with both allergic disease and repeated macro-parasitic infections. Population-based research on IgE has been limited by the logistical constraints associated with obtaining and processing venipuncture blood samples. In this short report, we present an enzyme immunoassay protocol for quantifying circulating total IgE levels in capillary whole blood, collected from a finger prick and dried on filter paper. The assay demonstrated acceptable levels of accuracy, precision, and reliability. IgE remained stable at room temperature for only 2,4 days and degraded rapidly at higher temperatures suggesting that samples should be refrigerated or frozen within 1,2 days of collection. It is hoped that the relative ease of blood spot collection will expand opportunities for population-based research on IgE.Am. J. Hum. Biol. 19:440,442, 2007. © 2007 Wiley-Liss, Inc. [source] Recovery of Growth of Hyphochytrium catenoides after Exposure to Environmental StressTHE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 4 2008FRANK H. GLEASON ABSTRACT. The survival of an isolate of Hyphochytrium catenoides collected from soil in the Blue Mountains in eastern New South Wales, Australia, was tested under extreme conditions in the laboratory. This isolate recovered growth after being subjected to drying on filter paper, to heat while desiccated, to hypersalinity, to strict anaerobic conditions, to freezing temperatures, and to a short period in solutions at pH 2.8,11.2. The capacity to survive under these conditions in the laboratory suggests adaptation to fluctuating conditions in the soil. The partial DNA sequence of the 28S ribosomal RNA gene in the isolate from New South Wales was 98% similar to that in an isolate from Arizona with a similar morphology. [source] Improved RP-HPLC determination of quinine in plasma and whole blood stored on filter paperBIOPHARMACEUTICS AND DRUG DISPOSITION, Issue 9 2000J.A. Kolawole Abstract Analysis of quinine in plasma and whole blood samples dried on filter paper is described. Sample preparation involves liquid extraction of plasma and whole blood from the filter paper and subsequent solid-phase extraction using C8 Bond Elut cartridges. A reverse-phase liquid chromatography system with UV detection and fluorescence detection was used. The analytical characteristics of the method are reported, with a quantification limit of 0.1 µg mL,1 and within an assay coefficient of variation of 5.6,8.4% in plasma and 6.5,12% in whole blood. Representative chromatograms are shown as a function of time for samples from human subjects after ingestion of a single 400-mg dose of quinine sulphate. Quinidine, dihydroquinine and metabolites are well separated from quinine with a resolution of above 1 (Rs>1). Copyright © 2000 John Wiley & Sons, Ltd. [source] Cellulose and Glass Fiber Affinity Membranes for the Chromatographic Separation of BiomoleculesBIOTECHNOLOGY PROGRESS, Issue 1 2004Eli Ruckenstein Macroporous cellulose and glass membranes were prepared from filter paper and glass fiber filter, respectively. To enhance their stability, the cellulose membranes were crosslinked with epichlorohydrin, and the glass membranes were crosslinked with glutaraldehyde or organic bifunctional silanes. Several pathways for the modification, activation, and ligand immobilization were used and compared. For cellulose membranes, the diazotization method provided the best results, whereas the glutaraldehyde method provided the best performance for glass membranes, regarding both their stability and ligand immobilization capacity. The characterization of the membranes was made by using a triazine dye, bovine serum albumin, and trypsin as test ligands. The membrane morphologies and the uniformities of ligand distribution across the membrane cartridges were investigated. Numerous affinity ligands were immobilized onto the membranes, and the prepared affinity membranes have been used to separate or purify concanavalin A, peroxidase, protease inhibitors, globulin, fibronectin, and other biomolecules. [source] Evaluation of the Murex HIV Ag/Ab Combination assay when used with dried blood spotsCLINICAL MICROBIOLOGY AND INFECTION, Issue 11 2007V. Lakshmi Abstract This study evaluated the ability of the Murex HIV Ag/Ab Combination assay to detect human immunodeficiency virus (HIV) antibodies in 12 617 dried blood spots (DBSs) on filter paper. The assay had an overall sensitivity of 99.6% and a specificity of 99.9%. In view of its ability to detect p24 antigen and both HIV-1 and HIV-2 antibodies in samples collected in the form of DBSs, the Murex Ag/Ab Combination assay is suitable for use as a standard screening assay for seroprevalence studies, as well as for routine diagnostic use in clinical laboratories. [source] Detection of the Sexual Identity of Conspecifics through Volatile Chemical Signals in a Territorial SalamanderETHOLOGY, Issue 3 2007Benjamin J. Dantzer Territorial red-backed salamanders (Plethodon cinereus) have been shown to use nonvolatile chemical signals in both territorial defense and to convey a variety of information to conspecifics. We investigated whether or not red-backed salamanders could determine the sexual identity of conspecifics through volatile chemical signals, and we explored their use in the context of territorial defense. We exposed male and female red-backed salamanders to four experimental treatments (i.e. filter papers that had been scent marked by male or female conspecifics for 1 and 5 d) and two control treatments (i.e. unscented filter papers for 1 and 5 d tests). The focal salamanders were prevented from physically accessing the scent marked filter papers and, presumably, some of the substrate scent marks had volatile components that were detected and interpreted by the focal salamanders. Both male and female red-backed salamanders spent significantly more time in threat displays when they were exposed to volatile chemical signals from same-sex conspecifics than they did toward similar signals from opposite-sex conspecifics. A similar statistical pattern was observed for the amount of chemosensory sampling exhibited by focal red-backed salamanders. From these results, we infer that red-backed salamanders can determine the sexual identity of conspecifics through volatile chemical signals, some of which may be used in territorial defense. Further, such airborne pheromones may influence the spatial organization of salamander territories on the forest floor. [source] Oviposition deterrence of shoots and essential oils of Minthostachys spp. (Lamiaceae) against the potato tuber mothJOURNAL OF APPLIED ENTOMOLOGY, Issue 2 2007P. C. Guerra Abstract:, The potato tuber moth is a noxious pest of potato in stores, where the use of repellent plants is an environmentally sound alternative to the application of chemical pesticides. We evaluated the protective effect of native Minthostachys species (Lamiaceae) against tuber infestation by the potato tuber moth in a rustic store in Cusco, Perú. We covered potato tubers with dried shoots of Minthostachys spicata and Minthostachys glabrescens and compared tuber damage with a control treatment of maize straw. We also conducted a no-choice oviposition bioassay in the laboratory, testing the oviposition deterrence of essential oils of M. spicata, M. glabrescens and Minthostachys mollis at natural concentrations. We recorded the number of eggs laid by mated moths on filter paper treated with essential oils of each of the three species and on two control treatments: hexane and untreated blank. Finally, we tested for differences in oviposition deterrence among five full-sib families of potato tuber moth raised under identical conditions. We found that dried, chopped leaves and flowers of Minthostachys species reduced the percentage of tuber damage in stores in comparison with the control (5% vs. 12%), but no difference in protection was found between species. Essential oils at natural concentrations deterred moth oviposition, reducing the number of eggs laid by about 80% compared with the control treatments; again, there were no significant differences between Minthostachys species. Finally, whereas we detected among-family variation in oviposition on filter papers treated with essential oils, no difference was found in the number of eggs laid on control substrates. Therefore, there was genetic variation for oviposition deterrence in the potato tuber moth and resistance to repellent plants might evolve thereafter. [source] A Novel Method for Air Drying Aloe Leaf Slices by Covering with Filter Papers as a Shrink-Proof LayerJOURNAL OF FOOD SCIENCE, Issue 9 2009S.A. Kim ABSTRACT:, To prevent the shrinkage of aloe vera slices during air drying, a method utilizing a shrink-proof layer was developed. The sample was configured of whole leaf aloe slices, where 1 side or both sides were covered with filter papers as shrink-proof layers. After air drying by varying the air temperature and the slice thickness, the drying characteristics, as well as several quality factors of the dried aloe vera leaf slices, were analyzed. In the simulation of the drying curves, the modified Page model showed the best fitness, representing a diffusion-controlled drying mechanism. Nonetheless, there was a trace of a constant-rate drying period in the samples dried by the method. Shrinkage was greatly reduced, and the rehydration ratios increased by approximately 50%. Scanning electron microscopic analysis revealed that the surface structure of original fibrous form was well sustained. FT-IR characteristics showed that the dried samples could sustain aloe polysaccharide acetylation. Furthermore, the functional properties of the dried slices including water holding capacity, swelling, and fat absorption capability were improved, and polysaccharide retention levels increased by 20% to 30%. Therefore, we concluded that application of shrink-proof layers on aloe slices provides a novel way to overcome the shrinkage problems commonly found in air drying, thereby improving their functional properties with less cost. Practical Application: This research article demonstrates a novel air drying method using shrink-proof layers to prevent the shrinkage of aloe slices. We analyzed extensively the characteristics of shrinkage mechanism and physical properties of aloe flesh gels in this drying system. We concluded that this method can be a beneficial means to retain the functional properties of dried aloe, and a potential alternative to freeze drying, which is still costly. [source] Comparison of bacterial plaque samples from titanium implant and tooth surfaces by different methodsCLINICAL ORAL IMPLANTS RESEARCH, Issue 1 2006Jeanne Gerber Abstract: Studies have shown similarities in the microflora between titanium implants or tooth sites when samples are taken by gingival crevicular fluid (GCF) sampling methods. The purpose of the present study was to study the microflora from curette and GCF samples using the checkerboard DNA,DNA hybridization method to assess the microflora of patients who had at least one oral osseo-integrated implant and who were otherwise dentate. Plaque samples were taken from tooth/implant surfaces and from sulcular gingival surfaces with curettes, and from gingival fluid using filter papers. A total of 28 subjects (11 females) were enrolled in the study. The mean age of the subjects was 64.1 years (SD±4.7). On average, the implants studied had been in function for 3.7 years (SD±2.9). The proportion of Streptococcus oralis (P<0.02) and Fusobacterium periodonticum (P<0.02) was significantly higher at tooth sites (curette samples). The GCF samples yielded higher proportions for 28/40 species studies (P -values varying between 0.05 and 0.001). The proportions of Tannerella forsythia (T. forsythensis), and Treponema denticola were both higher in GCF samples (P<0.02 and P<0.05, respectively) than in curette samples (implant sites). The microbial composition in gingival fluid from samples taken at implant sites differed partly from that of curette samples taken from implant surfaces or from sulcular soft tissues, providing higher counts for most bacteria studied at implant surfaces, but with the exception of Porphyromonas gingivalis. A combination of GCF and curette sampling methods might be the most representative sample method. [source] | ||||||||||||||||||||||||||||