Home About us Contact
|
Home About us Contact | ||
|
|
||
Cleaning
Kinds of Cleaning Terms modified by Cleaning Selected AbstractsTHE FOULING AND CLEANING OF ULTRAFILTRATION MEMBRANES DURING THE FILTRATION OF MODEL TEA COMPONENT SOLUTIONSJOURNAL OF FOOD PROCESS ENGINEERING, Issue 3 2007DAN WU ABSTRACT Proteins and polyphenols are the principal fouling constituents in the ultrafiltration (UF) of black tea liquor. The aim of this study was to determine the relative importance of individual components in the fouling process, to investigate any synergetic interactions that were occurring and to compare the cleaning characteristics of different fouled membranes. A 30-kD molecular weight cutoff polysulfone UF membrane in dead-end mode was challenged with model solutions of tea components. Model solutions consisted of tea proteins, theaflavins (TFs), thearubigins and caffeine. Sodium hydroxide was used as a cleaning reagent. Permeate flux decline curves were presented for single components and mixtures. Individual component transfer fluxes and rejections were also presented. An unexpected finding was that protein in a mixture with TFs could permeate the membrane to a degree, while a protein solution in the absence of the polyphenol was completely rejected. The inspection of membranes fouled by different solutions revealed different foulant morphologies. Membrane cleaning with 0.2 wt % sodium hydroxide was generally found to be effective. [source] MORNING CLEANING: JEFF WALL AND THE LARGE GLASSART HISTORY, Issue 5 2009CHRISTINE CONLEY Jeff Wall's Morning Cleaning, Mies van der Rohe Foundation, Barcelona, 1999, is a cinematographic digital transparency picturing the German Pavilion designed by Mies for the 1929 International Exposition in Barcelona and reconstructed in the 1980s. The tableau involves the arrested action of a male cleaner, oblivious to the gaze of the spectator, as he washes the windows separating the interior from an outdoor pool, where the morning sun illuminates Georg Kolbe's sculpture Dawn. Contrary to Michael Fried's reading of Morning Cleaning as a renewal of the antitheatrical aims of High Modernist painting, this essay looks to Duchamp's Large Glass as the model for its structuring tensions. Morning Cleaning is considered as a Duchampian delay in relation to the politics of modernist glass architecture in Wall's Kammerspiel essay, and as a ,countermonument' to the reconstructed pavilion as fetish, emptied of social meaning and the traumatic history of modernity. [source] Drug use among female sex workers in Hanoi, VietnamADDICTION, Issue 5 2005Trung Nam Tran ABSTRACT Aims To describe the drug use practices among female sex workers (FSWs) in Hanoi and to identify factors associated with their drug injecting. Design, setting and particicipants A two-stage cluster survey of 400 FSWs was conducted from June to September, 2002. Participating FSWs were both establishment- (160) and street-based (240), who were practising in seven urban and one suburban districts of Hanoi. Measurements Subjects were interviewed face to face using a structured questionnaire. Findings Among the middle-class FSWs, 27% used drugs, of whom 79% injected. Among low-class FSWs, 46% used drugs and 85% injected. Among drug-using FSWs, 86% had started using drugs within the past 6 years. Among drug-injecting FSWs, 81% had started injecting within the past 4 years. Cleaning of injecting equipment was not common among those who shared. Having drug-injecting ,love mates', drug-using clients, longer residence in Hanoi, more clients and not currently cohabiting were found to be independently associated with drug injecting among FSWs. Conclusions The high prevalence of injecting drug use among FSWs makes them susceptible to HIV infection, and is a threat to their clients. There is a strong relationship between drug-using FSWs and male drug-using clients and non-client partners. Intervention to prevent drug use initiation among non-drug-using FSWs and harm reduction among drug-using FSWs are urgently needed. [source] Time-of-flight secondary ion mass spectrometry analysis of the application of a cationic conditioner to ,clean' hairINTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 5 2004A. Harvey In this study the applicability of the surface-sensitive Time-of-flight secondary ion mass spectrometry (ToF-SIMS) technique to hair analysis and associated aqueous processing is evaluated. ToF-SIMS analysis of ,as received' human hair indicates the presence of silicones, anionic surfactants, and cationic conditioners, from previous treatments, on the fiber surface. Cleaning of the hair with SLS or SLES results in adsorption of the surfactants onto the fiber surface. In particular, the more non-polar surfactant components have greater substantivity for the fiber surface, as indicated by the relative increase in their ToF-SIMS intensity. Application of the Incroquat Behenyl 18-MEA conditioner to both ,virgin' and bleached hair results in the adsorption of the cationic C18, C20, C22, and C21 surfactant components onto the hair surface. The ToF-SIMS data indicate higher levels of conditioner on the bleached hair relative to the undamaged hair. [source] Effects on titanium implant surfaces of chemical agents used for the treatment of peri-implantitisJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 1 2010Krisztina Ungvári Abstract The treatment of peri-implantitis, which causes tissue deterioration surrounding osseointegrated implants, involves surface decontamination and cleaning. However, chemical cleaning agents may alter the structure of implant surfaces. We investigated three such cleaning solutions. Commercially pure (grade 4) machined titanium discs (CAMLOG Biotechnologies AG, Switzerland) were treated with 3% H2O2 (5 min), saturated citric acid (pH = 1) (1 min) or chlorhexidine gel (5 min), and their surface properties were examined by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). Human epithelial cell attachment (24-h observation) and proliferation (72-h observation) were investigated via dimethylthiazolyl-diphenyltetrazolium bromide (MTT) and bicinchoninic acid (BCA) protein content assays. AFM revealed no significant difference in roughness of the three treated surfaces. XPS confirmed the constant presence of typical surface elements and an intact TiO2 layer on each surface. The XPS peaks after chlorhexidine gel treatment demonstrated CO and/or CO bond formation, due to chlorhexidine digluconate infiltrating the surface. MTT and BCA assays indicated similar epithelial cell attachments in the three groups; epithelial cell proliferation being significantly higher after H2O2 than after chlorhexidine gel treatment (not shown by BCA assays). These agents do not harm the Ti surface. Cleaning with H2O2 slightly enhances human epithelial cell growth, in contrast to chlorhexidine gel. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010. [source] ASSESSMENT OF MICROBIAL CONTAMINANTS PRESENT ON VACUUM LOADERS IN SHELL EGG PROCESSING FACILITIESJOURNAL OF FOOD SAFETY, Issue 3 2008D.R. JONES ABSTRACT This study was conducted to determine the pathogen prevalence on vacuum loader cup surfaces. An off-line (birds housed off-site) and a mixed (birds housed on-site and eggs brought from outside production) operation shell egg processing facility were sampled three times each. Twenty vacuum loader cups were randomly rinsed with sterile saline per visit. Total aerobic microorganisms and Enterobacteriaceae were enumerated, and the prevalence of Salmonella, Campylobacter and Listeria was determined. Aerobic microorganisms were ,5 log cfu/mL, with higher levels noted in the mixed operation. Enterobacteriaceae levels averaged 2.5 log cfu/mL but were higher in the off-line facility. Campylobacter was detected in 1.6% of the samples. Salmonella was detected in 3.3% of the samples with isolates serotyped as Salmonella anatum and Salmonella heidelberg. There was a high prevalence of Listeria (72%). Confirmed isolates were identified as Listeria innocua (98.8%) and Listeria monocytogenes (1.2%). Identification of the populations present on the cup surfaces will allow for the development of more effective cleaning and disinfection programs. PRACTICAL APPLICATIONS Vacuum loaders have previously been determined to be reservoirs for microorganisms in shell egg processing plants. Assessing the prevalence of prominent foodborne pathogens (Salmonella, Campylobacter and Listeria) on the vacuum loader cup surface would allow for more targeted approaches to cleaning and sanitation. High levels of aerobic organisms and Enterobacteriaceae were detected (,5 and 2.5 log cfu/mL, respectively). Furthermore, Campylobacter and Salmonella were also found, but at low prevalence. Listeria was detected in 72% of the samples. Cleaning and sanitation programs currently utilized in shell egg processing facilities need to be reassessed, and new technologies need to be developed to address the presence of Salmonella, Campylobacter and Listeria. [source] Impact of sorghum processing on phytate, phenolic compounds and in vitro solubility of iron and zinc in thick porridgesJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 5 2007AP Polycarpe Kayodé Abstract This study focussed on the impact of process variables on levels of phytate and phenolic compounds, and in vitro solubility of iron (Fe) and zinc (Zn) in sorghum porridges, a major staple in semi-arid tropics. The aim was to identify practices that enhance the mineral availability in this type of staple food. We studied the example of the West African porridge ,dibou' for which the processing methods involve grain cleaning, milling, sieving and cooking. Regional variations occur in the process, particularly in the cleaning which may be done wet or dry; sieving may be omitted in certain locations. Cleaning reduced the phytate content of the grain by 24,39%, while milling, sieving and cooking had no significant effect on phytate. Phenolic compounds measured as levels of reactive hydroxyl groups, remained constant after cleaning, milling and sieving, but significantly decreased by 38,65% after cooking. The Fe solubility tended to increase after cleaning but was drastically reduced due to cooking, and so was the soluble Zn. Levels of total phenolic compounds highly correlated with the Fe and Zn solubility (r2 = 0.73 and 0.82, respectively). Phenolic reaction products formed during the cooking process are presumably related with the extensive browning phenomenon observed in the dibou porridge, and with the reduction observed in Fe and Zn solubility. Copyright © 2007 Society of Chemical Industry [source] Trichophyton mentagrophytes of rabbit origin causing family incidence of kerion: an environmental studyMYCOSES, Issue 5 2006P. Van Rooij Summary Our laboratory was contacted by a family living directly above a rabbit farm. Both their children had developed a kerion, in consequence of a misdiagnosed superficial mycosis. This study was designed to demonstrate a link between the two kerion cases and the environmental contamination. The degree of contamination was estimated and factors favourising the spread of infection were determined. Dermatophytes were isolated from various environmental sites using Rodac plates. For direct sampling of scalp and fur the brushing technique was used. The farm and home environment initially showed a severe contamination by Trichophyton mentagrophytes. At the farm, cages and surfaces covered with rabbit hair were strongly contaminated. As for the home environment, the dog's basket and clothes from the mother carried a large number of spores. Trichophyton mentagrophytes was identified as responsible agent for the children's kerions and the lesions of the rabbits. Mother, eldest child and dog seemed to be excellent carriers. Cleaning and disinfection measures resulted in a reduction of the overall contamination. The home environment was no longer a source of contamination. Nevertheless, on the farm a fair number of dermatophytes could still be isolated from the wire meshes and roof beams covered with fluff. [source] Are therapeutic ultrasound units a potential vector for nosocomial infection?PHYSIOTHERAPY RESEARCH INTERNATIONAL, Issue 2 2006Siobhan Schabrun Abstract Background and Purpose.,Nosocomial infections present a widespread problem in today's healthcare environment, with a significant number of patients acquiring an infection annually. With the contemporary transition of immunocompromised and high-risk patients to community-based care, therapeutic ultrasound has the potential to be a vector of infection in the physiotherapy setting. The purpose of the present study was to determine the degree of contamination on therapeutic ultrasound transducer heads and ultrasound gel after routine clinical use, and to evaluate the efficacy of recommended infection control procedures.,Method.,The study consisted of two phases. Using a prospective cross-sectional design, microbiological cultures were obtained from 44 transducer heads and 43 gels. Subjects were drawn from a variety of physiotherapy practice settings. All samples containing more than five colony forming units per cm2 were considered contaminated. Following these measurements, a repeated-measures design was used to re-evaluate the 44 transducer heads for the amount and type of bacteria present after cleaning with a 70% alcohol wipe.,Results.,Twenty-seven per cent of transducer heads and 28% of gels were contaminated. Transducer heads showed fairly low levels of contamination across the sample, with the majority of organisms isolated found in normal skin and environmental flora. Gels were heavily contaminated with opportunistic and potentially pathogenic organisms, including Stenotrophomonas maltophilia, Staphylococcus aureus, Acinetobacter baumannii and Rhodotorula mucilaginosa. No multi-resistant organisms were identified. Cleaning with 70% alcohol significantly reduced the level of contamination on transducer heads (p < 0.01).,Conclusions.,Therapeutic ultrasound equipment is a potential vector for nosocomial infection in physiotherapy patients. The risk of infection from transducer heads can be effectively removed by cleaning with 70% alcohol between patients. Further research into possible strategies to reduce the risk of infection from ultrasound gels is needed. Copyright © 2006 John Wiley & Sons, Ltd. [source] Industrial sectors with high risk of women's hospital-treated injuriesAMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 1 2007Pete Kines PhD Abstract Background Women's occupational injury rates are converging with those of males. Associations between female workers' hospital treated injury rates, industrial sector and injured body area were analyzed to provide for better-focused injury prevention of women's hazardous jobs. Methods Females' standardized hospital treatment ratios (SHR) and the excess fraction for five body regions (head/neck, thorax, back, upper and lower extremities) were calculated for 58 industrial sectors for 1999,2003. Results Five industrial sectors, "Cleaning, laundries and dry cleaners," "Transport of passengers," "Hotels and restaurants," "Hospitals" and "Transport of goods" had significantly high SHRs for all five body regions. The excess fraction for upper extremity injuries revealed that 14%,27% of injuries could theoretically have been avoided. Conclusions There is strong evidence for an association between women's hospital treated injuries and industrial sector. The results justify the need for gender-sensitive analyses to orient injury prevention programs. Am. J. Ind. Med. 50:13,21, 2007. © 2006 Wiley-Liss, Inc. [source] Cleaning up the Bush messPUBLIC POLICY RESEARCH, Issue 2 2008Robert Reich After three decades of government starvation of necessary resources, the next US president needs to champion progressive taxation, argues Robert Reich. [source] A New Suction Device in Endolaryngeal Laser Surgery for Simultaneous Manipulation and CleaningTHE LARYNGOSCOPE, Issue 5 2005Karl-Bernd Huttenbrink No abstract is available for this article. [source] Nanoscience for Art Conservation: Oil-in-Water Microemulsions Embedded in a Polymeric Network for the Cleaning of Works of Art,ANGEWANDTE CHEMIE, Issue 47 2009Emiliano Carretti Dr. So gut wie neu: Öl-in-Wasser-Nanobehälter in einem wässrigen Polymernetzwerk ermöglichten ein effektives, weitgehend zerstörungsfreies und selektives Reinigen von bemalten und vergoldeten Oberflächen. Wechselwirkungen mit dem Polymer (im Bild schwarz) veränderten die Struktur der Mikroemulsions-Nanotröpfchen (hellblau und rot) kaum. Ein Foto einer Gleichgewichtsmischung aus Mikroemulsion und Polymer ist ebenfalls gezeigt. [source] MORNING CLEANING: JEFF WALL AND THE LARGE GLASSART HISTORY, Issue 5 2009CHRISTINE CONLEY Jeff Wall's Morning Cleaning, Mies van der Rohe Foundation, Barcelona, 1999, is a cinematographic digital transparency picturing the German Pavilion designed by Mies for the 1929 International Exposition in Barcelona and reconstructed in the 1980s. The tableau involves the arrested action of a male cleaner, oblivious to the gaze of the spectator, as he washes the windows separating the interior from an outdoor pool, where the morning sun illuminates Georg Kolbe's sculpture Dawn. Contrary to Michael Fried's reading of Morning Cleaning as a renewal of the antitheatrical aims of High Modernist painting, this essay looks to Duchamp's Large Glass as the model for its structuring tensions. Morning Cleaning is considered as a Duchampian delay in relation to the politics of modernist glass architecture in Wall's Kammerspiel essay, and as a ,countermonument' to the reconstructed pavilion as fetish, emptied of social meaning and the traumatic history of modernity. [source] An Overview of Complete Artificial Fixed Dentition Supported by Endosseous ImplantsARTIFICIAL ORGANS, Issue 1 2005Dennis Flanagan Abstract:, The construction of a complete restoration of the dentition by the surgical placement of endosseous titanium implants that support a fixed prosthesis in each jaw is possible. The positionings of the implants and teeth in the prostheses are important factors for a successful long-term result. Distribution of the occlusal biting forces over as many implants as possible is important. Off-axial occlusal biting forces should be diverted to the anterior jaws where the forces are not as great. The posterior teeth should be designed with flat occlusal surfaces that separate during excursionary mandibular chewing movements. Medial mandibular flexure caused by the contraction of the medial pterygoid muscle can be addressed by constructing the prosthesis in segments, so as not to have a rigid entity encased in flexing bone that may induce stress in the bone, potentially leading to loss of implant integration and failure. Segmenting also ensures an appropriate fit of the prosthesis with respect to casting and porcelain firing distortion. Lip support by means of a flange in the prosthesis may be necessary when there has been a large amount of bone loss from edentulous resorption. Cleaning and routine maintenance of the prostheses every 3,6 months is essential. [source] The Use of Electrolyzed Solutions for the Cleaning and Disinfecting of DialyzersARTIFICIAL ORGANS, Issue 12 2000Noriaki Tanaka Abstract: Recently, the use of electrolyzed solutions has attracted considerable interest in Japan. This study investigates the efficiency of electrolyzed solutions as disinfecting agents (DA) in the reuse of dialyzers and compares their efficiency to that of other disinfectants currently in use. The following 3 methods were employed. First, the rinsing time and rebound release of reused dialyzers were measured and compared after electrolyzed solutions, electrolyzed strong acid aqueous solution (ESAAS) and electrolyzed strong basic aqueous solution (ESBAS), made from reverse osmosis (RO) water (ESAAS, ESBAS; Generating apparatuses: Super Oxseed , 1000, Amano Corporation, Yokohama, Japan), 2% Dialox-cj (Teijin Gambro Medical, Tokyo, Japan), and 3.8% formalin were used as DAs. This involved performing dialysis with 2 types of dialyzers: a cellulose acetate membrane (CAM) dialyzer and a polysulfone membrane (PSM) dialyzer. The dialyzers were cleaned and disinfected using the different DA and left for 48 h. Next, after performing dialysis the dialyzer membranes were cleaned with a saline solution (0.9% NaCl) and RO water and then cleaned with the various DA. These membranes were observed using a scanning electron microscope (SEM) to check for the presence of physical and biological contaminants. Finally, in vitro tests were performed to determine the level of dialyzer clearance when PSM dialyzers were reused after having been cleaned and disinfected with the electrolyzed solutions. The rinsing time results for both the CAM and PSM dialyzers showed the electrolyzed solutions (ESBAS and ESAAS) as being undetectable within 10 min. With regard to the rebound release, for both the CAM and PSM dialyzers, the electrolyzed solutions were undetectable at all checking times between 30 and 240 min. Observation by SEM showed that cleaning with both ESAAS and ESBAS left the fewest contaminants, and cleaning with 2% Dialox-cj left the highest level of contaminants in the CAM dialyzers. With regard to experiments concerning use in vitro, no major changes in the dialyzer clearance were noticed after 6 uses. In every experiment, the previous investigations showed the electrolyzed solutions to be superior to 3.8% formalin and 2% Dialox-cj DA for the reuse of dialyzers. [source] Prozessstrategien zur optimalen Reinigungsfähigkeit am Beispiel des Titus-Zentrifugentrockners TZT 400CHEMIE-INGENIEUR-TECHNIK (CIT), Issue 11 2007S. Stahl Dipl.-Ing. Abstract Häufige Produktwechsel und immer kürzere Produktionszyklen stellen hohe Anforderungen an die Reinigungsfähigkeit von verfahrenstechnischen Maschinen und Apparaten. Vor allem in der Pharma- bzw. der Lebensmittelindustrie ist die Vermeidung von Kreuzkontamination von besonderer Bedeutung. Einige Apparate verbinden zwei Grundoperationen (Unit-Operations) in einem Verfahrensraum, wodurch sich sowohl die Handhabung als auch der Gesamtreinigungsaufwand reduziert. Der Titus-Zentrifugentrockner verbindet die mechanische Entfeuchtung mit einer nachgeschalteten thermischen Trocknung. Der letzte Verfahrensschritt beinhaltet eine ,Cleaning in Place" (CIP)-Prozedur, die von allen vorangegangenen Verfahrensschritten maßgeblich beeinflusst wird. Im Mittelpunkt dieser Arbeit steht die Bestimmung der optimalen Verfahrensparameter, die einerseits die sichere Verarbeitung von schwierigen Produkten ermöglicht und zum anderen die Grundlage für eine effiziente Reinigung liefert. Da eine validierte Reinigungsprozedur in pharmazeutischen Anwendungen, beispielsweise bei toxischen oder hochaktiven Produkten, einen wesentlichen Teil der Gesamtprozesszeit einnimmt, müssen alle Verfahrensschritte direkt aufeinander abgestimmt sein. [source] Kinetic and DFT Studies on the Photoinduced Desorption of Sulfur from Gold Nanoparticles Loaded on Titanium DioxideCHEMPHYSCHEM, Issue 12 2005Tomokazu Kiyonaga Cleaning poisoned gold catalysts: Kinetic analysis of the photoinduced desorption of sulfur from gold nanoparticles loaded on TiO2 particles in water revealed that the rate constant increases with increasing pH. Photoelectrochemical measurements and DFT calculations led to the conclusion that this reaction results from an upward shift in the Fermi energy of gold nanoparticles by irradiation. The picture shows a high-resolution TEM image of an Au nanoparticle on TiO2. [source] Unified Medical Language System Coverage of Emergency-medicine Chief ComplaintsACADEMIC EMERGENCY MEDICINE, Issue 12 2006Debbie A. Travers PhD Abstract Background Emergency department (ED) chief-complaint (CC) data increasingly are important for clinical-care and secondary uses such as syndromic surveillance. There is no widely used ED CC vocabulary, but experts have suggested evaluation of existing health-care vocabularies for ED CC. Objectives To evaluate the ED CC coverage in existing biomedical vocabularies from the Unified Medical Language System (UMLS). Methods The study sample included all CC entries for all visits to three EDs over one year. The authors used a special-purpose text processor to clean CC entries, which then were mapped to UMLS concepts. The UMLS match rates then were calculated and analyzed for matching concepts and nonmatching entries. Results A total of 203,509 ED visits was included. After cleaning with the text processor, 82% of the CCs matched a UMLS concept. The authors identified 5,617 unique UMLS concepts in the ED CC data, but many were used for only one or two visits. One thousand one hundred thirty-six CC concepts were used more than ten times and covered 99% of all the ED visits. The largest biomedical vocabulary in the UMLS is the Systematized Nomenclature of Medicine Clinical Terms (SNOMED CT), which included concepts for 79% of all ED CC entries. However, some common CCs were not found in SNOMED CT. Conclusions The authors found that ED CC concepts are well covered by the UMLS and that the best source of vocabulary coverage is from SNOMED CT. There are some gaps in UMLS and SNOMED CT coverage of ED CCs. Future work on vocabulary control for ED CCs should build upon existing vocabularies. [source] Differences between the sexes with regard towork-related skin disease ,CONTACT DERMATITIS, Issue 2 2000Birgitta Meding Work-related skin disease is common and usually presents as hand eczema. From the Occupational Injury Information System in Sweden, as well as from registers of industrial injuries in other countries, it is evident that females report skin disease more often than males. Epidemiological studies of hand eczema also show that women are more often affected than men, in particular young women. The most common type of hand eczema is irritant contact dermatitis, which is often caused by wet work. Many female-dominated occupations involve extensive wet work, e.g., hairdressing, catering, cleaning and health-care work. These occupations are also high-risk occupations for hand eczema. Experimental studies of skin irritation have not confirmed differences between the sexes; thus, the higher prevalence of irritant contact dermatitis among females is most likely due to exposure, occupational and non-occupational. Nickel allergy is the most common contact allergy, which is most frequent in young females, and in 30,40% results over time in hand eczema. Hand eczema has an impact on quality of life and females seem to report a higher degree of discomfort than males. To achieve the optimal effect of preventive efforts regarding occupational skin disease, the focus for prevention should aim at reducing wet exposure. [source] Pulp capping with adhesive resin-based composite vs. calcium hydroxide: a reviewDENTAL TRAUMATOLOGY, Issue 6 2000A. H. B. Schuurs Abstract , The results of some short-term experiments suggest that direct capping of a vital pulp with the modern resin-based composite systems may be as effective as capping with calcium hydroxide. Total cavity etching with 10% phosphoric acid seems to be safe for the exposed pulp, but unless annulled by calcium hydroxide 35% phosphoric acid may be disastrous. For hemostasis and cleaning of the pulp wound both sodium hypochlorite and saline seem suitable, whereas the effectiveness of a 2% chlorhexidine solution is questionable. Although hard-setting calcium hydroxide cements may induce the formation of dentin bridges, they appear not to provide an effective long-term seal against bacterial factors. Within a few years, the majority of mechanically exposed and capped pulps show infection and necrosis due to microleakage of such capping materials and tunnel defects in the dentin bridges. It is unknown whether newer types of resin containing calcium-hydroxide-products will act as a permanent barrier. The cytotoxicity of the resin-based composites and the temperature rise during polymerisation may not be of concern, but microleakage, sensitisation and allergic reactions may pose problems. Based on available data, pulp capping with resin-based composites may be said to be promising, but more and long-term research is mandatory before the method can be recommended. [source] Hydrogen Peroxide and Wound Healing: A Theoretical and Practical Review for Hair Transplant SurgeonsDERMATOLOGIC SURGERY, Issue 6 2008SARA WASSERBAUER MD BACKGROUND In most hair restoration practices, hydrogen peroxide has been routinely used to remove blood during and after hair transplant surgery. In other specialties, hydrogen peroxide is also used in these ways: wound cleaning, prevention of infection, hemostasis, and removal of debris. Despite its widespread use, there are still concerns and controversy about the potential toxic effect of hydrogen peroxide. OBJECTIVE The objective was to review all available literature including in vivo and in vitro effects of hydrogen peroxide, as well as general wound healing research. MATERIAL AND METHODS Literature up to and including the past three decades was investigated. RESULTS Two pilot studies were found, and there are not enough data examining the real impact of using hydrogen peroxide in hair transplant surgery. In other specialties, H2O2 appears to have positive effects, such as stimulation of vascular endothelial growth factor, induction of fibroblast proliferation, and collagen, or negative effects, such as cytotoxicity, inhibition of keratinocyte migration, disruption of scarless fetal wound repair, and apoptosis. CONCLUSIONS There are not enough data in hair restoration surgery about the use of hydrogen peroxide, and it is unknown and unclear what the optimum dilution should be. Positive and negative effects were found in other specialties. Further studies are recommended. [source] Simulation of the dissolution of weathered versus unweathered limestone in carbonic acid solutions of varying strengthEARTH SURFACE PROCESSES AND LANDFORMS, Issue 6 2007M. J. Thornbush Abstract A simulation was undertaken within a climatic chamber to investigate limestone dissolution under varied carbonic acid (H2CO3) strengths as a possible analogue for future increases in atmospheric CO2 arising from global warming. Twenty-eight samples cut from a block of Bath (Box Hill) limestone from Somerville College, Oxford, which had been removed during restoration after 150 years in an urban environment, were weighed and placed in closed bottles of thin plastic containing varying concentrations of H2CO3. Half of the stone samples were derived from exposed surfaces of the stone block (weathered) while the others were obtained from the centre of the block on unexposed surfaces (unweathered). The purpose of this was to compare dissolution of previously weathered versus unweathered surfaces in strong (pH 4·73) versus weak (pH 6·43) solutions of H2CO3. A temperature of c. 19 °C was maintained within the chamber representing a plausible future temperature in Oxford for the year 2200 given current warming scenarios. The simulation lasted 25 days with a few stone samples being removed midway. Stone samples show reduced weight in all cases but one. There was greater dissolution of stone samples in a strong H2CO3 solution as conveyed by higher concentrations of total hardness and Ca2+ in the water samples as well as enhanced microscopic dissolution features identified using SEM. The simulation confirms that enhanced atmospheric CO2 under global warming, given adequate moisture, will accelerate dissolution rates particularly of newly replaced limestone building stones. However, previously weathered surfaces, such as those on historical stone exposed for a century or more, appear to be less susceptible to the effects of such increased rainfall acidity. Conservation techniques which remove weathered surfaces, such as stone cleaning, may accelerate future decay of historical limestone structures by increasing their susceptibility to dissolution. Copyright © 2006 John Wiley & Sons, Ltd. [source] Voltammetric Antioxidant Analysis in Mineral Oil Samples Immobilized into Boron-Doped Diamond Micropore Array ElectrodesELECTROANALYSIS, Issue 12 2009Xiaohang Zhang Abstract Mineral oil microdroplets containing the model antioxidant N,N -didodecyl- N,,N, -diethyl-phenylene-diamine (DDPD) are immobilized into a 100×100 pore-array (ca. 10,,m individual pore diameter, 100,,m pitch) in a boron-doped diamond electrode surface. The robust diamond surface allows pore filling, cleaning, and reuse without damage to the electrode surface. The electrode is immersed into aqueous electrolyte media, and voltammetric responses for the oxidation of DDPD are obtained. In order to further improve the current responses, 20,wt% of carbon nanofibers are co-deposited with the oil into the pore array. Voltammetric signals are consistent with the oxidation of DDPD and the associated transfer of perchlorate anions (in aqueous 0.1,M NaClO4) or the transfer of protons (in aqueous 0.1,M HClO4). From the magnitude of the current response, the DDPD content in the mineral oil can be determined down to less than 1,wt% levels. Perhaps surprisingly, the reversible (or midpoint) potential for the DDPD oxidation in mineral oil (when immersed in 0.1 NaClO4) is shown to be concentration-dependent and to shift to more positive potential values for more dilute DDPD in mineral oil solutions. An extraction mechanism and the formation of a separate organic product phase are proposed to explain this behavior. [source] Trace Determination of Chromium by Square-Wave Adsorptive Stripping Voltammetry on Bismuth Film ElectrodesELECTROANALYSIS, Issue 21 2004Eleni Chatzitheodorou Abstract This works reports the use of adsorptive stripping voltammetry (AdSV) for the trace determination of chromium on a rotating-disk bismuth-film electrode (BFE). During the reductive accumulation step, all the chromium species in the sample were reduced to Cr(III) which was complexed with cupferron and the complex was accumulated by adsorption on the surface of a preplated BFE. The stripping step was carried out by using a square-wave (SW) potential-time voltammetric signal. Electrochemical cleaning of the bismuth film was employed, enabling the same bismuth film to be used for a series of measurements in the presence of dissolved oxygen. The experimental variables as well as potential interferences were investigated and the figures of merit of the method were established. Using the selected conditions, the 3, limit of detection for chromium was 100,ng L,1 (for 120,s of preconcentration) and the relative standard deviation was 3.6% at the 2,,g L,1 level (n=8). Finally, the method was applied to the determination of chromium in real samples with satisfactory results. [source] An efficient protein preparation for proteomic analysis of developing cotton fibers by 2-DEELECTROPHORESIS, Issue 22 2006Yuan Yao Abstract Preparation of high-quality proteins from cotton fiber tissues is difficult due to high endogenous levels of polysaccharides, polyphenols, and other interfering compounds. To establish a routine procedure for the application of proteomic analysis to cotton fiber tissues, a new protocol for protein extraction was developed by optimizing a phenol extraction method combined with methanol/ammonium acetate precipitation. The protein extraction for 2-DE was remarkably improved by the combination of chemically and physically modified processes including polyvinylpolypyrrolidone (PVPP) addition, acetone cleaning, and SDS replacement. The protocol gave a higher protein yield and vastly greater resolution and spot intensity. The efficiency of this protocol and its feasibility in fiber proteomic study were demonstrated by comparison of the cotton fiber proteomes at two growth stages. Furthermore, ten protein spots changed significantly were identified by MS/tandem MS and their potential relationships to fiber development were discussed. To the best of our knowledge, this is the first time that a protocol for protein extraction from cotton fiber tissues appears to give satisfactory and reproductive 2-D protein profiles. The protocol is expected to accelerate the process of the proteomic study of cotton fibers and also to be applicable to other recalcitrant plant tissues. [source] Anatomy of an overfill: a reflection on the processENDODONTIC TOPICS, Issue 1 2007ALAN H. GLUSKIN The design and implementation of shaping, cleaning and sealing objectives in root canal therapy are fraught with real and potential pitfalls when the anatomic complexity of the space and technical considerations for its instrumentation, disinfection and obturation are contemplated. This review will focus on the genesis of results that lead to endodontic overfills. We will look at how the literature defines overfill and overextension; attempt to address the consensus opinion on the definition of working length; and determine the effects of shaping geometry on overfill as well as the biological impact of obturation materials that go beyond the root canal space. In addition, this manuscript will highlight evidence for the prevention of overfills as well as focus on the local factors that affect repair and healing. [source] Timeliness and effectiveness in the surgical management of persistent post-treatment periapical pathosisENDODONTIC TOPICS, Issue 1 2005MIN-KAI WU Common problems that cause persistent post-treatment periapical pathosis include infection remaining in the apical inaccessible areas, extraradicular infection including apically extruded dentine debris with bacteria present in dentinal tubules, radicular true cysts, foreign body reactions, inadequate non-surgical root canal treatment with or without iatrogenically altered root canal morphology, and vertical root fractures. Inadequate root canal treatment may be corrected non-surgically, while more complex problems may require surgical intervention. The important factors that warrant a successful surgery include good quality of the orthograde root canal treatment, deep retrograde preparation of the apical canal, and carefully cleaning and filling of the exposed isthmuses and accessory canals. Ideally, apical surgery and orthograde retreatment are performed simultaneously. In a recent study, 97% of the lesions including large ones of >10 mm in diameter healed completely within 1 year after surgical intervention. Of the teeth that showed ,complete healing' at 4 years more than 85% already ,completely healed' at 2 years; thus, the endodontic post-treatment disease might be treated surgically or non-surgically within 2 years after the previous treatment. [source] Root canal morphology and its relationship to endodontic proceduresENDODONTIC TOPICS, Issue 1 2005Frank J. Vertucci The hard tissue repository of the human dental pulp takes on numerous configurations and shapes. A thorough knowledge of tooth morphology, careful interpretation of angled radiographs, proper access preparation and a detailed exploration of the interior of the tooth are essential prerequisites for a successful treatment outcome. Magnification and illumination are aids that must be utilized to achieve this goal. This article describes and illustrates tooth morphology and discusses its relationship to endodontic procedures. A thorough understanding of the complexity of the root canal system is essential for understanding the principles and problems of shaping and cleaning, for determining the apical limits and dimensions of canal preparations, and for performing successful microsurgical procedures. [source] The effect of cleaning and disinfecting the sampling well on the microbial communities of deep subsurface water samplesENVIRONMENTAL MICROBIOLOGY, Issue 1 2005Odile Basso Summary Our knowledge of the microbial characteristics of deep subsurface waters is currently very limited, mainly because of the methods used to collect representative microbial samples from such environments. In order to improve this procedure, a protocol designed to remove the unspecific, contaminant biofilm present on the walls of an approximately 800 m deep well is proposed. This procedure included extensive purges of the well, a mechanical cleaning of its wall, and three successive chlorine injections to disinfect the whole line before sampling. Total bacterial counts in water samples decreased from 2.5 × 105 to 1.0 × 104 per millilitre during the cleaning procedure. Culture experiments showed that the first samples were dominated by sulfate-reducers and heterotrophs, whereas the final sample was dominated by oligotrophic and hydrogenotrophic bacteria. Community structures established on the diversity of the 16S rRNA genes and data analysis revealed that the water sample collected, after a purge without removal of the biofilm, was characterized by numerous phyla which are not representative of the deep subsurface water. On the other hand, several bacterial phyla were only detected after the full cleaning of the well, and were considered as important components of the subsurface ecosystem which would have been missed in the absence of well cleaning. [source] | ||||||||||||||||||||||||||||||||||||||||||||||||||||