A novel family VII esterase with industrial potential from compost metagenomic library

<p>Abstract</p> <p>Background</p> <p>Among the vast microbial genomic resources now available, most microbes are unculturable in the laboratory. A culture-independent metagenomic approach is a novel technique that circumvents this culture limitation. For the screening of novel lipolytic enzymes, a metagenomic library was constructed from compost, and the clone of <it>estCS2 </it>was selected for lipolytic properties on a tributyrin-containing medium.</p> <p>Results</p> <p>The <it>estCS2 </it>sequence encodes a protein of 570 amino acid residues, with a predicted molecular mass of 63 kDa, and based on amino acid identity it most closely matches (45%) the carboxylesterase from <it>Haliangium ochraceum </it>DSM 14365. EstCS2 belong to family VII, according to the lipolytic enzyme classification proposed by Arpigny and Jaeger, and it retains the catalytic triad Ser₂₄₅-Glu₃₆₃-His₄₆₆that is typical of an α/β hydrolase. The Ser₂₄₅residue in the catalytic triad of EstCS2 is located in the consensus active site motif GXSXG. The EstCS2 exhibits strong activity toward <it>p</it>-nitrophenyl caproate (C6), and it is stable up to 60°C with an optimal enzymatic activity at 55°C. The maximal activity is observed at pH 9, and it remains active between pH 6-10. EstCS2 shows remarkable stability in up to 50% (v/v) dimethyl sulfoxide (DMSO) or dimethylformamide (DMF). The enzyme has the ability to cleave sterically hindered esters of tertiary alcohol, as well as to degrade polyurethanes, which are widely used in various industries.</p> <p>Conclusions</p> <p>The high stability of EstCS2 in organic solvents and its activity towards esters of ketoprofen and tertiary alcohols, and in polyurethane suggests that it has potential uses for many applications in biotransformation and bioremediation.</p

THE EFFECTS OF WHEELCHAIR CAMBER AND HANDRIM SIZE IN WHEELCHAIR BASKETBALL MOVEMENT

Improving the wheelchair design can be an important determinant of high performance in the wheelchair basketball. Researchers have focused on increasing the efficiency of the wheelchair, looking at the factors such as the seat position, handrim size, and wheel camber. Most handrim and wheel chamber studies, however, have focused only on the propulsive phase. Quick turn as well as fast propulsion is essential to the success in a wheelchair basketball game and the energy efficiency becomes particularly important in a prolonged wheelchair use. The purpose of this study was to investigate the effects of wheelchair camber and handrim size on the linear propulsion, turn velocity, and efficiency

Transparent actuator made with few layer graphene electrode and dielectric elastomer, for variable focus lens

A transparent dielectric elastomer actuator driven by few-layer-graphene (FLG) electrode was experimentally investigated. The electrodes were made of graphene, which was dispersed inN-methyl-pyrrolidone. The transparent actuator was fabricated from developed FLG electrodes.The FLG electrode with its sheet resistance of 0.45 kΩ/sq (80 nm thick) was implemented to mask silicone elastomer. The developed FLG-driven actuator exhibited an optical transparency of over 57% at a wavenumber of 600 nm and produced bending displacement performance ranging from 29 to 946 μm as functions of frequency and voltage. The focus variation was clearly demonstrated under actuation to study its application-feasibility in variable focus lens and various opto-electro-mechanical devices

The Surgical Outcome of Endoscopic Dacryocystorhinostomy According to the Obstruction Levels of Lacrimal Drainage System

ObjectivesMany factors influence the outcome of endoscopic dacryocystorhinostomy (DCR). One of the most important prognostic factors is the level of obstruction in the lacrimal drainage system. The main objective of this report is to evaluate both the frequency of obstruction by anatomical region of the lacrimal drainage system on dacryocystography (DCG) and the surgical outcome of endoscopic DCR according to the obstruction level.MethodsA retrospective series of 48 patients (60 eyes) who had undergone endoscopic DCR from January 2005 to November 2007 were enrolled. Preoperative evaluation consisted of a standard examination which included lacrimal irrigation, probing, DCG and osteomeatal unit (OMU) computed tomography. Patients were classified into four groups according to the obstruction level on DCG. Surgical outcome was evaluated postoperatively by subjective improvement of epiphora and patent rhinostomy opening on nasal endoscopic exam.ResultsOf 60 eyes, the levels of obstruction were the common canaliculus in 14 eyes (23.3%), the lacrimal sac in 13 eyes (21.7%), the duct-sac junction in 13 eyes (21.7%) and the nasolacrimal duct (NLD) in 20 eyes (33.3%). The ductsac junction obstruction was treated most successfully (100%), followed by NLD obstruction (90%), common canaliculus obstruction (78.6%) and saccal obstruction (69.2%).ConclusionIn patients with lacrimal drainage system obstruction, preoperative evaluation of obstruction level using DCG may be helpful for predicting the surgical outcome of endoscopic DCR. The saccal obstruction may have a worse prognosis than the other obstruction levels

Investigation on Health Effects of an Abandoned Metal Mine

To investigate potential health risks associated with exposure to metals from an abandoned metal mine, the authors studied people living near an abandoned mine (n=102) and control groups (n=149). Levels of cadmium, copper, arsenic, lead, and zinc were measured in the air, soil, drinking water, and agricultural products. To assess individual exposure, biomarkers of each metal in blood and urine were measured. β2-microglobulin, α1-microglobulin, and N-acetyl-beta-glucosaminidase and bone mineral density were measured. Surface soil in the study area showed 2-10 times higher levels of metals compared to that of the control area. Metal concentrations in the groundwater and air did not show any notable differences between groups. Mean concentrations of cadmium and copper in rice and barley from the study area were significantly higher than those of the control area (p<0.05). Geometric means of blood and urine cadmium in the study area were 2.9 µg/L and 1.5 µg/g Cr, respectively, significantly higher than those in the control area (p<0.05). There were no differences in the levels of urinary markers of early kidney dysfunction and bone mineral density. The authors conclude that the residents near the abandoned mine were exposed to higher levels of metals through various routes

Cardiac Autonomic Neuropathy as a Predictor of Deterioration of the Renal Function in Normoalbuminuric, Normotensive Patients with Type 2 Diabetes Mellitus

Our study was performed to determine whether cardiac autonomic neuropathy can predict deterioration of the renal function in normoalbuminuric, normotensive people with type 2 diabetes mellitus (DM). One hundred and fifty-six normoalbuminuric, normotensive people with type 2 DM were included in our retrospective longitudinal study. We categorized normal patterns, early patterns, and definite or severe patterns according to the results of the cardiac autonomic function test. Of 156 patients included, 54 had normal patterns, 75 had early patterns, 25 had definite or severe patterns, and 2 had atypical patterns. During a median follow-up of nine years, glomerular filtration rates (GFR) remained stable in the normal and early pattern groups (mean changes, 4.50% and 0.77%, respectively) but declined in those with definite or severe patterns (mean change, -10.28%; p=0.047). An abnormal heart response to the deep breathing test of the cardiac autonomic function tests was an independent predictor of GFR decline. Our data suggest that cardiac autonomic neuropathy, especially with a definite or severe pattern, might be associated with a subsequent deterioration in renal function in normoalbuminuric, normotensive people with type 2 DM

Identification of MYC as an antinecroptotic protein that stifles RIPK1-RIPK3 complex formation

The underlying mechanism of necroptosis in relation to cancer is still unclear. Here, MYC, a potent oncogene, is an antinecroptotic factor that directly suppresses the formation of the RIPK1-RIPK3 complex. Gene set enrichment analyses reveal that the MYC pathway is the most prominently down-regulated signaling pathway during necroptosis. Depletion or deletion of MYC promotes the RIPK1-RIPK3 interaction, thereby stabilizing the RIPK1 and RIPK3 proteins and facilitating necroptosis. Interestingly, MYC binds to RIPK3 in the cytoplasm and inhibits the interaction between RIPK1 and RIPK3 in vitro. Furthermore, MYC-nick, a truncated form that is mainly localized in the cytoplasm, prevented TNF-induced necroptosis. Finally, down-regulation of MYC enhances necroptosis in leukemia cells and suppresses tumor growth in a xenograft model upon treatment with birinapant and emricasan. MYC-mediated suppression of necroptosis is a mechanism of necroptosis resistance in cancer, and approaches targeting MYC to induce necroptosis represent an attractive therapeutic strategy for cancer