62 research outputs found
Interaction of Poly(Ethyleneglycol) Ether in Isotropic Region, L2, of Mixed Sodium Dodecyl Sulphate (SDS) - Sodium Caprylate (SCA) System
Mixed surfactants of SDS-SCA at weight ratio of 2:3 in SDS-SCAI
CJI130HlH20 system gives the largest inverse micelle region. This system is used
for further construction of the wlo microemulsion phase diagram where n-decane is
added into the system The SDS-SCA-CJI130HlCuJlnlH20 system shows a larger
w/o microemulsion region than the pure surfactants in surfactant/l-hexanollndecane/
water system Maximum water solubility is found at 65.0 weight percent of
n-decane and 35.0 weight percent of SDS-SCA-CJI130H. Polymers, mPEG2,000
and PEG8,000 are then added into the line above in the solution. The SDS-SCACJI130H-
CIOH221H20/mPEG2,000 system is observed to have a bigger isotropic
region than the SDS-SCA-CJI130H-CIOH2 20IPEG8,000 system These two systems are sensitive to temperature where the isotropic region change dramatically
as temperature is increased.
Nuclear Magnetic Resonance (NMR) is used to detect the interaction and the degree
of freedom of the molecules in the isotropic solution which consist of SDS, SCA,
CJI130H, ClOH22 aDd H20. This instrument is able to detect the formation of the
inverse micelle and the w/o microemulsion in the SDS-SCAlCJI130HlH20 and
SDS-SCA-CJI130HlClOH2:zIH20 systems. The only interaction between the
molecules are found in the SDS- SCA-CJI130H-Cl(JI2:zIH20ItnPEG2,OOO and the
SDS- SCA-CJI130H-C1oH221H20fPEG8,OOO systems. The viscosity of the solution confirms that the inverse micelle and the w/o
microemulsion are formed m the SDS-SCAlCJI130HlH20 and
SDS-SCA-CJI130HlCloH..20 systems. It is observed that the aggregations are
not geometrically packed together. The presence of the polymers, mPEG2,OOO and
PEG8,OOO in the SDS-SCA-CJI130HlC1oH2:zIH20 system can break the w/o
microemulsion
Emulsion Properties of Mixed Tween20-Span20 in Non-Aqueous System
Oil-in-glycerol (O/G) emulsion was prepared in the presence of different
weight ratios of mixed Tween20-Span20 surfactants. O/G emulsion was
observed to form below 50 wt% of oil content at 3 wt% of mixed Tween20Span20
surfactants. Physical properties of the emulsion were determined by
using a microscope, particle counting and rheological measurement. An
attempt to correlate HLB values of mixed Tween20-Span20 with emulsion
stability was also carried out
The impact of corticosteroid use on inpatients with inflammatory bowel disease and positive polymerase chain reaction for
Background/Aims Optimal management of inflammatory bowel disease (IBD) with concomitant Clostridium difficile infection (CDI) is controversial, especially when CDI diagnosis is made by polymerase chain reaction (PCR) testing, which may reflect colonization without infection. Methods We performed a multicenter review of all inpatients with IBD and PCR diagnosed CDI. Outcomes included length of stay, 30- and 90-day readmission, colectomy during admission and within 3 months, intensive care unit (ICU) admission, CDI relapse and death for patients who received corticosteroid (CS) after CDI diagnosis versus those that did not. Propensity-adjusted regression analysis of outcomes based on CS usage was performed. Results We identified 177 IBD patients with CDI, 112 ulcerative colitis and 65 Crohn’s disease. For IBD overall, CS after CDI diagnosis was associated with prolonged hospitalization (5.5 days: 95% confidence interval [CI], 1.5–9.6 days; P=0.008), higher colectomy rate within 3 months (odds ratio [OR], 5.5; 95% CI, 1.1–28.2; P=0.042) and more frequent ICU admissions (OR, 7.8; 95% CI, 1.5–41.6; P=0.017) versus no CS. CS use post-CDI diagnosis in UC patients was associated with prolonged hospitalization (6.2 days: 95% CI, 0.4– 12.0 days; P=0.036) and more frequent ICU admissions (OR, 7.4; 95% CI, 1.1–48.7; P=0.036). Conclusions CS use among IBD inpatients with CDI diagnosed by PCR is associated with poorer outcomes and would seem to reinforce the importance of C. difficile toxin assay to help distinguish colonization from infection. This adverse effect appears more prominent among those with UC
Optimization of the epoxidation of methyl ester of palm fatty acid distillate
Methyl ester of palm fatty acid distillate (PFAD-ME) can be used for producing epoxide compounds. PFADME consists of 39.3% of oleic acid (C18:1) and has an iodine value of 49.2 g I2/100 g. It can be converted to a low oxirane content epoxide which can be used for several applications, such as plasticizers, polyols or alkanolamines, with appropriate modification. Temperature, mole ratio of hydrogen peroxide to unsaturation, and mole ratio of formic acid to unsaturation were optimized in the epoxidation of PFAD-ME. The study showed that more than 98% conversion of unsaturation to the epoxide ring moiety can be achieved within 3 hr of reaction by using the optimum molar ratio of 1:1:4 (unsaturation: formic acid: hydrogen peroxide) and a temperature of 50°C
Experimental Investigation on Palm-Based Oil as Alternative for Biodegradable Power Transformer Oil Application in Malaysia
Most power transformers used petroleum-based oil or so-called mineral oil as insulation. Power transformer oil functions not only as electrical insulation and cooling medium but also to suppress corona and arcing. Over the years, power transformer oil has been widely used because of its high dielectric field strength, low dielectric losses, and long-term performance. However, petroleum-based power transformer oil is non-biodegradable and non-renewable. A serious spill could contaminate soil and water. As a non-renewable source, depletion of the source will further increase the price. These have encouraged researchers to look for alternative power transformer oil for better sustainability. Palm-based oil has been seen as a potential substitute, because, it is environmentally friendly, biodegradable and renewable. However, a lot of studies need to be carried out before it can be used as alternative power transformer oil commercially. Thus, this work has been carried out to investigate several electrical and physical properties of palm-based transformer oil, such as breakdown voltage, partial discharge characteristics, kinetic viscosity, and flash point. The effect of ageing on electrical properties of the palm-based oil has also been investigated. Two types of palm-based oil, namely Palm Fatty Acid Ester (PFAE) and Refined, Bleached, Deodorized Palm Oil (RBDPO) have been selected in this work. As a comparison, the commercially available soy-based biodegradable oil is also investigated for assessment and further analysis purpose. The results revealed that PFAE and RBDPO have great potential as power transformer insulation because of their good insulating characteristics as commercially available biodegradable oil
Intra-tumor genetic heterogeneity and alternative driver genetic alterations in breast cancers with heterogeneous HER2 gene amplification
Background HER2 is overexpressed and amplified in approximately 15% of invasive breast cancers, and is the molecular target and predictive marker of response to anti-HER2 agents. In a subset of these cases, heterogeneous distribution of HER2 gene amplification can be found, which creates clinically challenging scenarios. Currently, breast cancers with HER2 amplification/overexpression in just over 10% of cancer cells are considered HER2-positive for clinical purposes; however, it is unclear as to whether the HER2-negative components of such tumors would be driven by distinct genetic alterations. Here we sought to characterize the pathologic and genetic features of the HER2-positive and HER2-negative components of breast cancers with heterogeneous HER2 gene amplification and to define the repertoire of potential driver genetic alterations in the HER2-negative components of these cases.Results We separately analyzed the HER2-negative and HER2-positive components of 12 HER2 heterogeneous breast cancers using gene copy number profiling and massively parallel sequencing, and identified potential driver genetic alterations restricted to the HER2-negative cells in each case. In vitro experiments provided functional evidence to suggest that BRF2 and DSN1 overexpression/amplification, and the HER2 I767M mutation may be alterations that compensate for the lack of HER2 amplification in the HER2-negative components of HER2 heterogeneous breast cancers.Conclusions Our results indicate that even driver genetic alterations, such as HER2 gene amplification, can be heterogeneously distributed within a cancer, and that the HER2-negative components are likely driven by genetic alterations not present in the HER2-positive components, including BRF2 and DSN1 amplification and HER2 somatic mutations
Toll-like receptor gene polymorphisms are associated with susceptibility to graves' ophthalmopathy in Taiwan males
<p>Abstract</p> <p>Background</p> <p>Toll-like receptors (TLRs) are a family of pattern-recognition receptors, which plays a role in eliciting innate/adaptive immune responses and developing chronic inflammation. The polymorphisms of TLRs have been associated with the risk of various autoimmune diseases, including systemic lupus erythematosus (SLE), multiple sclerosis and rheumatorid arthritis. The aim of this study was to evaluate whether TLR genes could be used as genetic markers for the development of Graves' ophthalmopathy (GO).</p> <p>Methods</p> <p>6 TLR-4 and 2 TLR-9 gene polymorphisms in 471 GD patients (200 patients with GO and 271 patients without GO) from a Taiwan Chinese population were evaluated.</p> <p>Results</p> <p>No statistically significant difference was observed in the genotypic and allelic frequencies of TLR-4 and TLR-9 gene polymorphisms between the GD patients with and without GO. However, sex-stratified analyses showed that the association between TLR-9 gene polymorphism and GO phenotype was more pronounced in the male patients. The odds ratios (ORs) was 2.11 (95% confidence interval [CI] = 1.14-3.91) for rs187084 AàG polymorphism and 1.97 (95% CI = 1.07-3.62) for rs352140 AàG polymorphism among the male patients. Increasing one G allele of rs287084 and one A allele of rs352140 increased the risk of GO (<it>p </it>values for trend tests were 0.0195 and 0.0345, respectively). Further, in haplotype analyses, the male patients carrying the GA haplotype had a higher risk of GO (odds ratio [OR] = 2.02, 95% confidence interval [CI] = 1.09-3.73) than those not carrying the GA haplotype.</p> <p>Conclusion</p> <p>The present data suggest that TLR-9 gene polymorphisms were significantly associated with increased susceptibility of ophthalmopathy in male GD patients.</p
A friction-wear correlation for four-ball extreme pressure lubrication
A first-ever friction-wear model for Four-Ball Extreme Pressure (EP) Lubrication test (ASTM D2783) is presented in this work. The model considers the rate of entropy generation and dissipation within the lubricated tribosystem to establish the friction-wear correlations for 12 lubricating oils comprising minerals, esters and other formulated oils. The correlations can be used to calculate the probability to pass/fail in the EP lubrication. The probability has similar trend as load-wear index from ASTM D2783 method. Besides, the friction-wear correlations allows quick estimation of EP performance of an unknown lubrication, upon comparing with that of an established one. The methods demonstrated here will help researchers or lubricant technologist to characterize the EP behavior quickly without over-relying on tribotester
New genetic loci link adipose and insulin biology to body fat distribution.
Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms
- …