936 research outputs found
An Updated Meta-Analysis: Risk Conferred by Glutathione S-Transferases ( GSTM1
Purpose. To study the effects of glutathione S-transferase M1 (GSTM1) and T1 (GSTT1) polymorphisms on age-related cataract (ARC). Methods. After a systematic literature search, all relevant studies evaluating the association between GSTs polymorphisms and ARC were included. Results. Fifteen studies on GSTM1 and nine studies on GSTT1 were included in this meta-analysis. In the pooled analysis, a significant association between null genotype of GSTT1 and ARC was found (OR = 1.229, 95% CI = 1.057–1.429, and P=0.007). In subgroup analysis, the association between cortical cataract (CC) and GSTM1 null genotype was statistically significant (OR = 0.713, 95% CI = 0.598–0.850, and P<0.001). In addition, GSTM1 null genotype was significantly associated with ARC causing risk to individuals working indoors and not individuals working outdoors. The association between GSTT1 null genotype and risk of ARC was statistically significant in Asians (OR = 1.442, 95% CI = 1.137–1.830, and P=0.003) but not in Caucasians. Conclusions. GSTM1 positive genotype is associated with increased risk of CC and loses the protective role in persons who work outdoors. Considering the ethnic variation, GSTT1 null genotype is found to be associated with increased risk of ARC in Asians but not in Caucasians
Methyl 2-{[2,8-bis(trifluoromethyl)quinolin-4-yl]oxy}acetate
In the crystal structure of the title compound, C14H9F6NO3, molecules are connected by intermolecular C—H⋯O hydrogen bonds. The best planes through the benzene and pyridyl rings make a dihedral angle of 1.59 (12)°
Effect of Substrate Concentration on the Synthesis of Cefaclor by Penicillin Acylase with in Situ Product Removal
Enzymatic synthesis of 3-chloro-7-D-(2-phenylglycinamide)-3-cephem-4-carboxylic
acid (cefaclor) by penicillin acylase (PA) was carried out with in situ product removal (ISPR) under kinetic control. The yield of cefaclor highly depended on substrate concentrations and the ratio of nucleus to acyl donor. Substrate concentrations were optimized
as 50 mmol l–1 of 7-aminodesacetoxymethyl-3-chlorocephalosporanic acid (7ACCA)
and 100 mmol l–1 of phenylglycine methyl ester (PGME) at the conditions: temperature 20 °C, pH 6.3; and enzyme load was 8 IU ml–1. It is effective to improve the transfer of acyl donor through controlling the substrate concentration with feeding acyl donor. The
conversion of nucleus and acyl donor was improved to 93 % and 62 %, respectively
Observing white dwarf tidal stripping with TianQin gravitational wave observatory
Recently discovered regular X-ray bursts known as quasi-periodic eruptions
have a proposed model that suggests a tidal stripping white dwarf inspiralling
into the galaxy's central black hole on an eccentric orbit. According to this
model, the interaction of the stripping white dwarf with the central black hole
would emit gravitational wave signals as well, their detection can help explore
the formation mechanism of quasi-periodic eruptions and facilitate
multi-messenger observations. In this paper, we aim to perform a preliminary
study of the gravitation wave observation of TianQin on this stripping white
dwarf model. We investigated the horizon distance of TianQin on this type of
gravitation wave signal and found it can be set to 200Mpc. We also find that
those stripping white dwarf model sources with central black hole mass within
are more likely to be detected by TianQin. We
assessed the parameter estimation precision of TianQin on those stripping white
dwarf model sources. Our result shows that, even in the worst case, TianQin can
determine the central black hole mass, the white dwarf mass, the central black
hole spin, and the orbital initial eccentricity with a precision of .
In the optimistic case, TianQin can determine the central black hole mass and
the white dwarf mass with a precision of , determine the central black
hole spin with a precision of , and determine the orbital initial
eccentricity with a precision of . Moreover, TianQin can determine the
luminosity distance with a precision of and determine the sky
localization with a precision of .Comment: 9 pages, 4 figure
Seasonal variation in systemic lupus erythematosus and rheumatoid arthritis: an ecological study In based on internet searches
Systemic lupus erythematosus (SLE) is a prototypical autoimmune disease in which immune regulation is disrupted and characterized by intense inflammation and damage to multiple organs or systems. Rheumatoid arthritis (RA) is another systemic autoimmune disease characterized by chronic synovial joint inflammation that leads to disability and poor quality of life. Although the etiologies and pathogenesis of SLE and RA are not fully understood, it is generally accepted that they are both caused by interactions between genetic and environmental factors. In recent years, emerging studies have demonstrated the potential role of seasonality in the development and disease activity of variety of autoimmune diseases [[1], [2], [3]]
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