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Limited Study (limited + study)
Selected AbstractsMechanisms and modes for ignition of low-voltage, PVC-insulated electrotechnical productsFIRE AND MATERIALS, Issue 2 2006Vytenis BabrauskasArticle first published online: 1 AUG 200 Abstract PVC is the most common insulation material used for wiring in low-voltage (LV) service. ,Low-voltage', in the context of this paper, is taken to be 120,240 VAC. The electrotechnical products considered include insulated wires, cables and cords, and also appurtenant termination devices, e.g. male plugs or female taps. Well-known factors leading to the ignition of PVC-insulated wiring and related products include: (a) manufacturing defects; (b) grossly excessive current; (c) over-insulation, sometimes augmented by overcurrent; (d) localized heating due to strand breakage; (e) localized heating due to mechanical strand severing by staples or nails; and (f) localized heating due to failed terminations. Other failure modes are known but have received only limited study. These include (i) excessive force and creep; (ii) chemical interaction effects; and (iii) breakdown under voltage surge conditions. Additional research is needed in these areas. The proximate cause of ignition involved with many of the above mechanisms is arc tracking (arcing across a carbonized path). In turn, it is shown that PVC is especially susceptible to becoming charred, it requiring only approximately 160°C for the material to become semiconducting during short-term exposure (around 10 h), while longer-term exposure (around 1 month) may cause failures at temperatures as low as 110°C. Some limited data exist which suggest that standard UL and IEC temperature classifications are unduly optimistic, as applied to PVC. Fire can originate if wiring or equipment cannot withstand a powerline surge. Mains-connected electrical appliances need to be designed to resist 6000 V surge voltages, even though this is not mandated in most of the current UL and IEC standards. Data are presented showing that the IEC 60112 wet-tracking test gives especially misleading results for PVC and should be improved or abrogated. Copyright © 2005 John Wiley & Sons, Ltd. [source] Health-related quality of life in patients with Primary Sjögren's Syndrome and Xerostomia: a comparative studyGERODONTOLOGY, Issue 1 2002Jocelyne Rostron Abstract Objective: To compare the health status of groups of Primary Sjögren's and Xerostomia patients, using the Medical Outcomes Short Form 36 (SF-36). The SF-36 is a generic measure, divided into eight domains, used in the assessment of health-related quality of life. Patients and methods: The SF-36 was given to 2 groups: Group 1 comprised 43 patients diagnosed with Primary Sjögren's Syndrome (1SS) and an unstimulated whole salivary flow rate (UFR) of <0.1 ml/min). Group 2 (n = 40) reported Xerosiomia but had an UFR >0.2 ml/min. Sub groups of patients in Groups 1 and 2 were compared with community normative data, for the SF-36 Results: There were trends to suggest lower SF36 scores for 1SS patients but there were no significant differences between the mean domain scores of Groups 1 and 2. 1SS and Xerostomia patients registered lower mean scores across all 8 domains, compared with normative community data. Conclusion: The SF-36 was unable to detect significant differences between subjects with 1SS and Xerostomia but a larger sample size is required to confirm these findings. The results of this limited study suggest that a disease-specific measure is required to assess the impact 1SS on health-related Quality of life (QOL). [source] Maxillary obturators: The relationship between patient satisfaction and speech outcomeHEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 11 2003Jana M. Rieger PhD Abstract Background. Patient satisfaction with a maxillary obturator has been studied in relation to extent of surgical defect, sociodemographic characteristics, scores on mental health inventories, and psychosocial adjustment to illness scales. However, review of the literature reveals limited study of the relationship between patient satisfaction with an obturator and clinical speech outcome measures. The purpose of this study is to relate patient satisfaction scores obtained by questionnaire with those obtained by means of clinical speech measurements. Methods. Acoustical, aeromechanical, and perceptual measurements of speech were collected for 20 patients after receiving a definitive obturator. Patient satisfaction with their obturator was later measured with the Obturator Functioning Scale (OFS). Results. Results reveal that poorer aeromechanical speech results were associated with patient-reported avoidance of social events, whereas lower speech intelligibility outcomes were related to overall poorer perception of speech function on the OFS. Several background patient characteristics were significantly related to several responses on the OFS and to the aeromechanical assessment outcomes. Conclusions. Results from instrumental assessments of speech seem to be informative regarding not only speech outcome but also a patient's satisfaction with the obturator. Consideration of background patient characteristics is important when interpreting both clinically obtained and patient-perceived outcomes. © 2003 Wiley Periodicals, Inc. Head and Neck 25: 000,000, 2003 [source] Mobility of shear thinning viscous drops in a shear Newtonian carrying flow using DR-BEMINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 12 2009M. Giraldo Abstract The study of drop behaviour has attracted great interest in the last years due to its importance in different industrial and biological systems. Most available works focus on Newtonian drops, excluding some very important applications such as polymer mixing. Simulations of non-Newtonian drops have had only limited study, mostly in time-dependent rheologies or simple flow cases. This work presents a boundary-only formulation based on the dual reciprocity method to model the motion and deformation of non-Newtonian shear thinning drops due to a shear Newtonian unbounded carrying flow. Pair-wise interactions at low Reynolds number between two viscous shear thinning non-Newtonian drops are numerically simulated in order to obtain mobility magnitudes under linear shear flow of different strengths. Separation of the drops in the direction perpendicular to the imposed flow field at high capillary number (small surface tension) and low viscosity ratio was favoured by shear thinning, increasing in magnitude as the capillary number increases and the viscous ratio decreases. Higher values of this separation occur at higher values of the viscosity ratio when compared with the case of Newtonian drops. In order to obtain a good physical description of the non-Newtonian drop behaviour, while maintaining good computational performance, the non-Newtonian viscosity is made to obey the truncated power law model. Copyright © 2008 John Wiley & Sons, Ltd. [source] Selective expression of inhibitory Fc, receptor by metastatic melanoma impairs tumor susceptibility to IgG-dependent cellular responseINTERNATIONAL JOURNAL OF CANCER, Issue 12 2008Lydie Cassard Abstract During melanoma progression, patients develop anti-tumor immunity including the production of anti-tumor antibodies. Although the strategies developed by malignant cells to escape anti-tumor cellular immunity have been extensively investigated, little is known about tumor resistance to humoral immunity. The main effect of IgG antibodies is to activate the immune response by binding to host Fc gamma receptors (Fc,R) expressed by immune cells. We previously reported in a limited study that some human metastatic melanoma cells ectopically express the Fc,RIIB1, an inhibitory isoform of Fc,R. By analyzing a large panel of different types of human primary and metastatic solid tumors, we report herein that expression of Fc,RIIB is restricted to melanoma and is acquired during tumor progression. We show that Fc,RIIB expression prevents the lysis of human metastatic melanoma cells by NK cell-mediated antibody-dependent cellular cytotoxicity (ADCC) in vitro, independently of the intracytoplasmic region of Fc,RIIB. Using experimental mouse models, we demonstrate that expression of Fc,RIIB protects B16F0 melanoma tumors from the ADCC induced by monoclonal and polyclonal anti-tumor IgG in vivo. Thus, our results identify Fc,RIIB as a marker of human metastatic melanoma that impairs the tumor susceptibility to Fc,R-dependent innate effector responses. © 2008 Wiley-Liss, Inc. [source] Carbaryl exposure and incident cancer in the Agricultural Health StudyINTERNATIONAL JOURNAL OF CANCER, Issue 8 2007Rajeev Mahajan Abstract Carbaryl is a carbamate insecticide with a broad spectrum of uses in agricultural, commercial and household settings. It has previously been linked with non-Hodgkin lymphoma (NHL) but studies of cancer risk in humans are limited. We examined occupational carbaryl use and risk of all cancers in the Agricultural Health Study, a prospective study of a cohort of pesticide applicators in North Carolina and Iowa. This analysis included 21,416 subjects (1,291 cases) enrolled from 1993,1997 and followed for cancer incidence through 2003. Pesticide exposure and other data were collected using self-administered questionnaires. Poisson regression was used to calculate rate ratios (RRs) and 95% confidence intervals (CIs) while controlling for potential confounders. Carbaryl was not associated with cancer risk overall. Relative to subjects who never used carbaryl, melanoma risk was elevated with >175 lifetime exposure-days (RR = 4.11; 95%CI, 1.33,12.75; p -trend = 0.07), >10 years of use (RR = 3.19; 95%CI, 1.28,7.92; p -trend = 0.04), or ,10 days of use per year (RR = 5.50; 95%CI, 2.19,13.84; p -trend < 0.001). Risk remained after adjusting for sunlight exposure. Although not significant, there appeared to be a trend of decreasing prostate cancer risk with increasing level of exposure. A small increase in NHL risk was observed using some, but not all, exposure measures. No associations were observed with other examined cancer sites. Because the observed results were not hypothesized a priori and because of limited study of their biological plausibility, they should be interpreted with caution. © 2007 Wiley-Liss, Inc. [source] Comparisons of Isolates of Fusarium avenaceum from White Lupin and Other Crops by Pathogenicity Tests, DNA Analyses and Vegetative Compatibility TestsJOURNAL OF PHYTOPATHOLOGY, Issue 4 2000K. Satyaprasad Isolates of Fusarium avenaceum, mostly from crops of white lupin or wheat, were tested for pathogenicity on white lupin and wheat plants and compared by DNA tests and, in a limited study, vegetative compatibility. Most of the 80 isolates were pathogenic on both plant species after inoculation on shoot bases. Disease severity was greater at higher incubation temperatures that ranged from 15/10°C to 25/20°C (day/night temperatures). Isolates from lupin crops tended to be more pathogenic, on average, on lupins than on cereals. Polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) analysis of the internal transcribed spacer region of the rDNA distinguished two groups of isolates that occurred in different proportions among isolates from lupins and cereal crops. Random amplified polymorphic DNA (RAPD)-PCR analyses indicated considerable genetic variation among isolates, but there was some similarity among groups of isolates from populations in the same field. Genetic diversity was confirmed by a high degree of vegetative incompatibility among 20 isolates using nitrate nonutilizing mutants. There were no relationships among pathogenicity, RFLP group, RAPD group and vegetative compatibility group. Zusammenfassung Fusarium-avenaceum -Isolate, die überwiegend von Weißier Lupine oder Weizen stammten, wurden hinsichtlich ihrer Pathogenität für Weißie Lupine und Weizenpflanzen getestet und durch DNA-Tests verglichen. In einer kleineren Studie wurde zudem ihre vegetative Kompatibilität geprüft. Die meisten der 80 Isolate waren nach Inokulation der Stengel-bzw. Halmbasis für beide Pflanzenarten pathogen. Bei hohen Inkubationstemperaturen im Bereich von 15/10°C bis 25/20°C (Tag/Nacht-Temperaturen) war der Befall stärker. Von Lupinen stammende Isolate waren im Durchschnitt stärker pathogen für Lupinen als für Getreide. Eine PCR-RFLP-Analyse der Internal-transcribed-spacer-Region der rDNA teilte die Isolate in zwei Gruppen, die bei den Isolaten von Lupinen und Getreide in verschiedenen Anteilen vertreten waren. RAPD-PCR-Analysen zeigten eine beträchtliche genetische Variation bei den Isolaten, aber auch gewisse Ähnlichkeiten bei den Isolatgruppen, die von Populationen im selben Feld stammten. Die genetische Diversität wurde auch durch ein hohes Ausmaßi an vegetativer Inkompatibilität bei 20 Isolaten deutlich; hier wurden Nitrat nicht verwertende Mutanten verwendet. Zwischen Pathogenität, RFLP-Gruppe, RAPD-Gruppe und vegetativer Kompatibilitätsgruppe bestanden keine Beziehungen. [source] The effect of amitriptyline on pain intensity and perception of stress in bruxersJOURNAL OF PROSTHODONTICS, Issue 2 2001Ariel J. Raigrodski DMD Purpose The purpose of this clinical pilot study was to evaluate the effect of a tricyclic antidepressant, amitriptyline, on pain-intensity level and level of stress in bruxers. Materials and Methods In a randomized, double-blind, crossover experimental design, 10 subjects received active (amitriptyline 25 mg/night) and inactive (placebo 25 mg/night) medication, over a period of 4 weeks. Results The administration of amitriptyline for 4 weeks did not significantly (p > .05) reduce pain intensity. However, it significantly (p < .05) reduced the level of stress perception. Conclusion The results of this limited study do not support the administration of small doses of amitriptyline over a period of 4 weeks for the management of pain resulting from sleep bruxism. However, the results support the administration of small doses of amitriptyline for the management of the perception of stress levels associated with sleep bruxism. [source] USE OF HIGH-DOSE GADOLINIUM AS CONTRAST MEDIA TO AVOID RADIOCONTRAST MEDIA-INDUCED NEPHROPATHYJOURNAL OF RENAL CARE, Issue 1 2009Prajej Ruangkanchanasetr SUMMARY Patients at risk for radiocontrast media-induced nephropathy (RCIN) with suspected peripheral vascular disease were evaluated with high-dose (0.4 mmol/kg) gadolinium-based (Gd) contrast angiography (AG). The patients who were considered susceptible to RCIN were defined by having one or more of the following: (1) pre-existing serum creatinine (SCr) >124 ,mol/l, (2) diabetes mellitus and (3) age >60 years. An increase in SCr , 44 ,mol/l or , 25% of baseline was considered significant. Ten patients underwent peripheral AG using a high dose of Gd without any adverse reaction. The mean age was 67.8 years. Nine (90%) patients were diabetic. The quality of these images was satisfactory for diagnosis in eight out of 10 patients. None of these patients had significant change in SCr. The mean SCr (±SD) before, at 48 hours and at 72 hours after AG were 182 ± 97, 177 ± 99 and 177 ± 98 ,mol/l, respectively. Based on this limited study, Gd is a promising agent for peripheral angiographic study. In patients at risk for RCIN, the high dose of Gd appears to be safe without obvious nephrotoxicity. [source] Improved Cryopreservation of Sperm of Paddlefish (Polyodon spathula)JOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 4 2006ÁKos Horváth Experiments were performed to improve protocols for sperm cryopreservation of paddlefish (Polyodon spathula), a species for which there has been limited study. The first experiment was conducted to investigate the effects of two extenders (modified Tsvetkova's extender: mT and modified Hanks' balanced salt solution: mHBSS) in combination with methanol (MeOH) and dimethyl sulfoxide in two concentrations (5 and 10%) on the postthaw motility and fertilization rates of cryopreserved sperm. The highest postthaw motility (85 ± 5%) was observed when sperm were frozen using mT extender with 10% MeOH as cryoprotectant. Extenders (P = 0.0018) and cryoprotectants (P = 0.0040) each had a significant effect on the postthaw motility of paddlefish sperm. The highest fertilization (80 ± 3%) was found when eggs were fertilized with sperm frozen with mT extender in combination with 10% MeOH. However, there was no significant difference among fertilization rates when MeOH was used as a cryoprotectant in either concentration or in combination with either mT or mHBSS extenders. In the second experiment, 4000 eggs were fertilized with the pooled contents of five straws of thawed sperm (total volume of 1.25 mL) using mT extender in combination with 5% MeOH, and hatch rates as high as 79 ± 5% were observed. A third experiment was also conducted to clarify the role of MeOH concentration; however, no significant difference was found among fertilization and hatch rates when either 5 or 10% MeOH was used as a cryoprotectant. These results suggest that MeOH is a safe and reliable cryoprotectant for freezing of paddlefish sperm and obtaining viable postthaw sperm for consistent fertilization and hatch rates. Further, this experimental protocol is relatively simple and applicable for commercial hatchery production of paddlefish. [source] Experimental autoimmune cholangitis: a mouse model of immune-mediated cholangiopathyLIVER INTERNATIONAL, Issue 5 2000David E. J. Jones Abstract:Background: Primary biliary cirrhosis (PBC) is characterised by intra-hepatic immune-mediated cholangiopathy (non-suppurative destructive cholangitis (NSDC)). Although auto-reactive immune responses against pyruvate dehydrogenase complex (PDC) have been characterised in PBC, the lack of an animal model of the disease has limited study of the mechanisms of disease induction and the development of novel approaches to therapy. Aims: To develop and validate a mouse model of immune-mediated cholangiopathy relevant for future use in the study of the aetio-pathogenesis and therapy of PBC. Methods: Female SJL/J, C57BL/6, NOD and BALB/c mice were sensitised with PDC, its purified E2/E3BP component, and a PDC-E2 derived peptide p163 (a dominant T-cell epitope in humans) in complete Freund's adjuvant (CFA). Morphological changes were assessed under light microscopy by a hepatic histopathologist blinded to the experimental details. Antibody responses to PDC were studied by ELISA and PDC inhibition assay. Results: An initial series of experiments was performed to survey the susceptibility of female mice of a range of strains to the induction of NSDC by i.p. sensitisation with PDC, PDC-E2/E3BP or p163 in CFA. Although each animal showed a specific antibody response following sensitisation, it was found that NSDC development (assessed at 30 weeks post-sensitisation) was restricted to SJL/J mice following sensitisation with any of the mitochondrial antigen preparations. A subsequent series of experiments was performed to examine the specificity and aetiology of this disease. Significant bile duct lesions were only seen in SJL/J animals following sensitisation with CFA containing PDC, and were absent from CFA only and un-sensitised controls. Kinetic analysis revealed that this pathology developed slowly, but a high incidence of animals with severe lesions was observed after 30 weeks. Conclusions: We have described a model of experimental autoimmune cholangitis (EAC) with immunological (anti-PDC antibodies) and histological (immune-mediated cholangiopathy) features suggestive of PBC. This model may be useful in further defining the role of self-tolerance breakdown in the development of this condition. [source] Short-term clinical and quality-of-life outcomes in women treated by the TVT-Secur procedureAUSTRALIAN AND NEW ZEALAND JOURNAL OF OBSTETRICS AND GYNAECOLOGY, Issue 2 2010Jeanette L. LIM Background:, The TVT-Secur (Ethicon, Somerville, NJ, USA) is a minimally invasive suburethral synthetic sling used in the treatment of female stress urinary incontinence. It claims to cause less postoperative pain and to enable performing in an office setting. However, this may be at the expense of a significant learning curve and a higher early failure rate. Aims:, To assess objectively the success rate of the TVT-Secur procedure in the ,U' configuration at six months. Secondary outcomes focussed on subjective success rates, complications, patient satisfaction and quality-of-life (QOL). Methods:, A prospective observational study was undertaken at two tertiary referral urogynaecology centres. A cohort of 42 consecutive patients with urodynamic stress incontinence who underwent the TVT-Secur procedure in the ,U' configuration between November 2006 and August 2007 were followed up for six months. Three standardised QOL questionnaires were completed preoperatively and at six months. A urogenital history, visual analogue score (VAS) for patient satisfaction, uroflow and urinary stress test were performed at six months. Results:, Recruitment was ceased prematurely because of a high number of early failures. Objective and subjective success rates at six months were 58.3% and 51.3% respectively. Complications included urinary tract infections, voiding difficulty, groin discomfort, haematoma, vaginal pain, tape erosion and intra-operative dislodgement of tape. Prevalence of de novo urge incontinence was 10.3%. Only symptom-specific QOL scores improved and only 48.6% indicated a high level satisfaction (VAS , 80%) with TVT-Secur. Conclusion:, On the basis of this limited study, we are hesitant to recommend the ,U' configuration of the TVT-Secur over its more established counterparts, the TVT and TVT-O. [source] Public health impact of isoniazid-resistant Mycobacterium tuberculosis strains with a mutation at amino-acid position 315 of katG: a decade of experience in The NetherlandsCLINICAL MICROBIOLOGY AND INFECTION, Issue 8 2006H. R. Van Doorn Abstract A previous limited study demonstrated that Mycobacterium tuberculosis isolates with a mutation at amino-acid position 315 of katG (,315) exhibited high-level resistance to isoniazid and were more frequently resistant to streptomycin. In the present study, isoniazid-resistant M. tuberculosis isolates from 8332 patients in The Netherlands (1993,2002) were screened for the ,315 mutation. Isoniazid resistance was found in 592 (7%) isolates, of which 323 (55%) carried ,315. IS6110 restriction fragment length polymorphism analysis showed that ,315 isolates occurred in clusters, suggesting recent transmission, at the same frequency as isoniazid-susceptible isolates. In contrast, other isoniazid-resistant isolates clustered significantly less frequently. ,315 isolates were high-level isoniazid-resistant, streptomycin-resistant and multidrug-resistant significantly more often, and may have a greater impact on public health, than other isoniazid-resistant isolates. 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