Origin of Limiting and Overlimiting Currents in Bipolar Membranes.

Bipolar membranes (BPMs), a special class of ion exchange membranes with the unique ability to electrochemically induce either water dissociation or recombination, are of growing interest for environmental applications including eliminating chemical dosage for pH adjustment, resource recovery, valorization of brines, and carbon capture. However, ion transport within BPMs, and particularly at its junction, has remained poorly understood. This work aims to theoretically and experimentally investigate ion transport in BPMs under both reverse and forward bias operation modes, taking into account the production or recombination of H+ and OH-, as well as the transport of salt ions (e.g., Na+, Cl-) inside the membrane. We adopt a model based on the Nernst-Planck theory, that requires only three input parameters─membrane thickness, its charge density, and pK of proton adsorption─to predict the concentration profiles of four ions (H+, OH-, Na+, and Cl-) inside the membrane and the resulting current-voltage curve. The model can predict most of the experimental results measured with a commercial BPM, including the observation of limiting and overlimiting currents, which emerge due to particular concentration profiles that develop inside the BPM. This work provides new insights into the physical phenomena in BPMs and helps identify optimal operating conditions for future environmental applications.

Jogging and weight training associated with increased high-density lipoprotein cholesterol levels in Taiwanese adults.

Background: Although previous studies have shown that aerobic and resistance exercise increase high-density lipoprotein cholesterol (HDL-C) levels, the optimal type of exercise has not been determined. Therefore, the purpose of this study was to investigate the association of jogging (a type of aerobic exercise) and weight training (a type of resistance exercise) with HDL-C levels in Taiwanese adults. Methods: The data used in this cross-sectional study were obtained from the Taiwan Biobank (TWB), which is a national health resource that contains the genetic information of Taiwanese volunteers aged 30-70 years. A total of 75,635 subjects (47,881 women and 27,754 men) were included in this study. The subjects were divided into four groups: jogging (n = 2,278), weight training (n = 522), mixed exercise (n = 519), and no exercise (n = 72,316). The TWB data were collected through questionnaires (e.g. basic characteristics, lifestyle factors, and disease history), biochemical tests, and anthropometric measurements. Results: Compared with no exercise, jogging, weight training, and mixed exercise were all associated with higher HDL-C levels (ß = 2.5470, 2.6249, and 3.2117, respectively). As seen, the ß value was highest for the mixed exercise group, followed by weight training and then jogging (p for trend <0.0001). Conclusions: In the current study, jogging and weight training were individually associated with higher levels of HDL-C. Engaging in both activities was associated with much higher levels of HDL-C. Our findings suggest that regular jogging and weight training might play an important role in increasing HDL-C levels.

Associations between cigarette smoking status and health-related physical fitness performance in male Taiwanese adults.

Background: The highest proportion of smoking behavior occurs in male adults in Taiwan. However, to our knowledge, no study has investigated the relationship between smoking behavior and health-related physical fitness according to education level, health status, betel nut-chewing status and obesity in male adults aged 18 years or older in Taiwan. Aims: This study aimed to determine the associations between cigarette smoking and health-related physical fitness performance in male Taiwanese adults. Methods: This was a cross-sectional study conducted on 27,908 male adults (aged 23-64 years) who participated in Taiwan's National Physical Fitness Survey 2014-2015. Data from a standardized structured questionnaire, anthropometric variables, and health-related physical fitness measurements were analyzed. Individuals were categorized as never smoking cigarettes, former smoker, and current smoker. Multiple linear regression analysis was performed to evaluate the association between cigarette smoking and health-related physical fitness performance. Results: Never smoking group exhibited a lower (p < 0.05) proportion of abdominal obesity, higher (p < 0.05) proportion of perceived good health status, and greater (p < 0.05) performance in 1-min sit-up and sit-and-reach tests when compared with current smoking and former smoking group. Former smoking group had the highest (p < 0.05) performance in 3-min step test among all groups. Current smoker was significantly negatively (p < 0.05) associated with 3-min step, 1-min sit-up and sit-and-reach tests. Notably, former smoker was significantly positively (p < 0.05) associated with 3-min step and 1-min sit-up tests, but still negatively (p < 0.05) associated with sit-and-reach performance. Conclusion: Current smoker was associated with an increased the risk of abdominal obesity, reduced the perceived health status and health-related physical fitness performance. Quitting smoking had beneficial effect on the perceived good health status, cardiorespiratory and muscular fitness in male Taiwanese adults, but not on flexibility performance. Further research on the ameliorate mechanism underlying this phenomenon is warranted.

Deep Learning-Based Automatic Detection of ASPECTS in Acute Ischemic Stroke: Improving Stroke Assessment on CT Scans.

(1) Background: The Alberta Stroke Program Early CT Score (ASPECTS) is a standardized scoring tool used to evaluate the severity of acute ischemic stroke (AIS) on non-contrast CT (NCCT). Our aim in this study was to automate ASPECTS. (2) Methods: We utilized a total of 258 patient images with suspected AIS symptoms. Expert ASPECTS readings on NCCT were used as ground truths. A deep learning-based automatic detection (DLAD) algorithm was developed for automated ASPECTS scoring based on 168 training patient images using a convolutional neural network (CNN) architecture. An additional 90 testing patient images were used to evaluate the performance of the DLAD algorithm, which was then compared with ASPECTS readings on NCCT as performed by physicians. (3) Results: The sensitivity, specificity, and accuracy of DLAD for the prediction of ASPECTS were 65%, 82%, and 80%, respectively. These results demonstrate that the DLAD algorithm was not inferior to radiologist-read ASPECTS on NCCT. With the assistance of DLAD, the individual sensitivity of the ER physician, neurologist, and radiologist improved. (4) Conclusion: The proposed DLAD algorithm exhibits a reasonable ability for ASPECTS scoring on NCCT images in patients presenting with AIS symptoms. The DLAD algorithm could be a valuable tool to improve and accelerate the decision-making process of front-line physicians.

Structure-Guided Regulation in the Enantioselectivity of an Epoxide Hydrolase to Produce Enantiomeric Monosubstituted Epoxides and Vicinal Diols via Kinetic Resolution.

Structure-guided microtuning of an Aspergillus usamii epoxide hydrolase was executed. One mutant, A214C/A250I, displayed a 12.6-fold enhanced enantiomeric ratio (E = 202) toward rac-styrene oxide, achieving its nearly perfect kinetic resolution at 0.8 M in pure water or 1.6 M in n-hexanol/water. Several other beneficial mutants also displayed significantly improved E values, offering promising biocatalysts to access 19 structurally diverse chiral monosubstituted epoxides (97.1 - ≥ 99% ees) and vicinal diols (56.2-98.0% eep) with high yields.

Structure-guided improvement in the enantioselectivity of an Aspergillus usamii epoxide hydrolase for the gram-scale kinetic resolution of ortho-trifluoromethyl styrene oxide.

Microtuning the substrate-binding pocket (SBP) of EHs has emerged as an effective approach to manipulate their enantio- or regio-selectivities and activities towards target substrates. Here, the enantioselectivity (enantiomeric ratio, E) of AuEH2 towards a racemic (rac-) ortho-trifluoromethyl styrene oxide (o-TFMSO) was improved via microtuning its SBP. Based on the analysis on the crystal structure of AuEH2, its specific residues I192, Y216, R322 and L344 lining the SBP in close to the catalytic triad were identified for site-saturation mutagenesis. After screening, five single-site mutants were selected with E values elevated from 8 to 12-25 towards rac-o-TFMSO. To further improve E, four double-site mutants were constructed by combinatorial mutagenesis of AuEH2R322V separately with AuEH2I192V, AuEH2Y216F, AuEH2L344A and AuEH2L344C. Among all the mutants, AuEH2R322V/L344C possessed the largest E of 83 with activity of 67 U/g wet cell. The kinetic resolution of 200 mM rac-o-TFMSO was conducted at 0 °C for 5.5 h using 80 mg/mL wet cells of E. coli/Aueh2R322V/L344C, a transformant expressing AuEH2R322V/L344C, retaining (S)-o-TFMSO with 98.4 % ees and 49.3 % yields. Furthermore, the molecular docking simulation analysis indicated that AuEH2R322V/L344C more enantiopreferentially attacks the terminal carbon (Cß) in the oxirane ring of (R)-o-TFMSO than AuEH2.

The effect of redox potential on the removal characteristic of divalent cations during activated carbon-based capacitive deionization.

The main objective of the study is to explore the removal characteristics of Cu2+ and Zn2+ ions in activated carbon-based capacitive deionization (CDI). In this work, CDI experiments were performed to remove divalent ions (e.g., Cu2+, Zn2+, and Ca2+) from single- and multicomponent aqueous solutions. As evidenced, divalent heavy metals could be successfully removed by charging the CDI cell at 1.2 V. Notably, the preferential removal of Cu2+ ions over Zn2+ and Ca2+ ions was observed in the charging step. The removal capacities for Cu2+, Zn2+, and Ca2+ ions in a competitive environment were 29.6, 19.6, and 13.8 µmol/g, respectively. In contrast, the regeneration efficiencies for the removal of Cu2+ and Zn2+ were much lower than that of Ca2+, suggesting the occurrence of irreversible Faradaic reactions on the cathode. X-ray photoelectron spectroscopy analysis demonstrated that Cu2+ ions were reduced to Cu(I) and Zn2+ ions were transformed to ZnO/Zn(OH)2 on the cathode. Therefore, there were two major mechanisms for the removal of divalent heavy metal ions: capacitive electrosorption and cathodic electrodeposition. Specifically, the reduction potential played a crucial role in determining the removal characteristics. When regarding divalent cations with similar hydrated sizes, the divalent cation with a higher reduction potential tended to be separated by cathodic electrodeposition rather than double-layer charging, indicating the high removal selectivity of activated carbon-based CDI. This paper constitutes a significant contribution to promoting the application of CDI for contaminant sequestration.

Nearly perfect kinetic resolution of racemic o-nitrostyrene oxide by AuEH2, a microsomal epoxide hydrolase from Aspergillus usamii, with high enantio- and regio-selectivity.

Only a few known epoxide hydrolases (EHs) displayed activity towards o-nitrostyrene oxide (4a), presumably owing to the large steric hindrance caused by o-nitro substituent. Therefore, excavating EHs with high activity and enantio- and/or regio-selectivity towards racemic (rac-) 4a is essential but challenging. Here, AuEH2 from Aspergillus usamii was expressed in E. coli BL21(DE3). E. coli/Aueh2, an E. coli transformant expressing AuEH2, possessed EH activities of 16.2-184 U/g wet cell towards rac-styrene oxide (1a) and its derivatives (2a-13a), and the largest enantiomeric ratio of 96 towards rac-4a. The regioselectivity coefficients, ßR and ßS, of AuEH2 were determined to be 99.2% and 98.9%, suggesting that it regiopreferentially attacks the Cß in the oxirane rings of (R)- and (S)-4a. Then, the nearly perfect kinetic resolution of 20 mM rac-4a in pure water was carried out using 20 mg/mL wet cells of E. coli/Aueh2 at 25 °C for 50 min, retaining (S)-4a with over 99% ees and 48.9% yields, while producing (R)-o-nitrophenyl-1,2-ethanediol (4b) with 95.3% eep and 49.8% yieldp. To elucidate the molecular mechanism of AuEH2 with high enantiopreference for (R)-4a, its crystal structure was solved by X-ray diffraction and the molecular docking of AuEH2 with (R)- or (S)-4a was simulated.

Highly regio- and enantio-selective hydrolysis of two racemic epoxides by GmEH3, a novel epoxide hydrolase from Glycine max.

A novel epoxide hydrolase from Glycine max, designated GmEH3, was excavated based on the computer-aided analysis. Then, gmeh3, a GmEH3-encoding gene, was cloned and successfully expressed in E. coli Rosetta(DE3). Among the ten investigated rac-epoxides, GmEH3 possessed the highest and best complementary regioselectivities (regioselectivity coefficients, αS = 93.7% and ßR = 97.2%) in the asymmetric hydrolysis of rac-m-chlorostyrene oxide (5a), and the highest enantioselectivity (enantiomeric ratio, E = 55.6) towards rac-phenyl glycidyl ether (7a). The catalytic efficiency (kcatS/KmS = 2.50 mM-1 s-1) of purified GmEH3 for (S)-5a was slightly higher than that (kcatR/KmR = 1.52 mM-1 s-1) for (R)-5a, whereas the kcat/Km (5.16 mM-1 s-1) for (S)-7a was much higher than that (0.09 mM-1 s-1) for (R)-7a. Using 200 mg/mL wet cells of E. coli/gmeh3 as the biocatalyst, the scale-up enantioconvergent hydrolysis of 150 mM rac-5a at 25 °C for 1.5 h afforded (R)-5b with 90.2% eep and 95.4% yieldp, while the kinetic resolution of 500 mM rac-7a for 2.5 h retained (R)-7a with over 99% ees and 43.2% yields. Furthermore, the sources of high regiocomplementarity of GmEH3 for (S)- and (R)-5a as well as high enantioselectivity towards rac-7a were analyzed via molecular docking (MD) simulation.

Near-perfect kinetic resolution of o-methylphenyl glycidyl ether by RpEH, a novel epoxide hydrolase from Rhodotorula paludigena JNU001 with high stereoselectivity.

In order to provide more alternative epoxide hydrolases for industrial production, a novel cDNA gene Rpeh-encoding epoxide hydrolase (RpEH) of Rhodotorula paludigena JNU001 identified by 26S rDNA sequence analysis was amplified by RT-PCR. The open-reading frame (ORF) of Rpeh was 1236 bp encoding RpEH of 411 amino acids and was heterologously expressed in Escherichia coli BL21(DE3). The substrate spectrum of expressed RpEH showed that the transformant E. coli/Rpeh had excellent enantioselectivity to 2a, 3a, and 5a-10a, among which E. coli/Rpeh had the highest activity (2473 U/g wet cells) and wonderful enantioselectivity (E = 101) for 8a, and its regioselectivity coefficients, αR and ßS, toward (R)- and (S)-8a were 99.7 and 83.2%, respectively. Using only 10 mg wet cells/mL of E. coli/Rpeh, the near-perfect kinetic resolution of rac-8a at a high concentration (1000 mM) was achieved within 2.5 h, giving (R)-8a with more than 99% enantiomeric excess (ees) and 46.7% yield and producing (S)-8b with 93.2% eep and 51.4% yield with high space-time yield (STY) for (R)-8a and (S)-8b were 30.6 and 37.3 g/L/h.

Greatly enhancing the enantioselectivity of PvEH2, a Phaseolus vulgaris epoxide hydrolase, towards racemic 1,2-epoxyhexane via replacing its partial cap-loop.

To achieve the kinetic resolution and enantioconvergent hydrolysis of rac-1,2-epoxyhexane, the E value of PvEH2 was enhanced by substituting its partial cap-loop. Based on the experimental results reported previously and computer-aided analysis, the flexible and variable cap-loop, especially its middle segment, was speculated to be related to the catalytic properties of PvEH2. In view of this, four PvEH2's hybrids, Pv2St, Pv2Pv1, Pv2Vr1 and Pv2Vr2, were designed by substituting the middle segment (190EGMGSNLNTSMP201) of a cap-loop in PvEH2 with the corresponding ones in StEH, PvEH1, VrEH1 and VrEH2, respectively. Then, the hybrid-encoding genes, pv2st, pv2pv1, pv2vr1 and pv2vr2, were constructed by fusion PCR, and expressed in E. coli Rosetta(DE3). The expressed hybrid, Pv2St, displayed the highest specific activity of 35.3 U/mg protein towards rac-1,2-epoxyhexane. The corresponding transformant, E. coli/pv2st, exhibited the largest E value of 24.2, which was 11.5-fold that of E. coli/pveh2 expressing PvEH2. The scale-up kinetic resolution of 280 mM rac-1,2-epoxyhexane was carried out using 40 mg dry cells/mL of E. coli/pv2st at 25 °C for 4.5 h, retaining (S)-1,2-epoxyhexane with >99.5% ees and 36.9% yield. Additionally, the chemo-enzymatic enantioconvergent hydrolysis of rac-1,2-epoxyhexane using E. coli/pv2st followed by sulfuric acid produced (R)-hexane-1,2-diol with 73.0% eep and 86.5% yield.

Manipulating regioselectivity of an epoxide hydrolase for single enzymatic synthesis of (R)-1,2-diols from racemic epoxides.

Both the activity and regioselectivity of Phaseolus vulgaris epoxide hydrolase were remarkably improved via reshaping two substrate tunnels based on rational design. The elegant one-step enantioconvergent hydrolysis of seven rac-epoxides was achieved by single mutants, allowing green and efficient access to valuable (R)-1,2 diols with high eep (90.1-98.3%) and yields.

Interaction between Sex and LDLR rs688 Polymorphism on Hyperlipidemia among Taiwan Biobank Adult Participants.

Hyperlipidemia is one of the strong risk factors for ischemic heart disease. Using the Taiwan Biobank (TWB) database, we evaluated the risk of hyperlipidemia and its interaction with sex and rs688 polymorphism on the low-density lipoprotein receptor (LDLR) gene. Data collection in the biobank started in 2008 and is ongoing. Data analysis was performed on the participants' data collected between 2008 and 2015. In general, 27.92% of the 9237 female participants and 32.65% of the 8690 male participants were identified with hyperlipidemia. Compared to the C/C genotype, C/T and T/T genotypes were not significant risk factors for hyperlipidemia (OR = 1.061, CI: 0.976-1.153 for C/T and OR = 1.052, CI: 0.845-1.309 for T/T genotype) in the general model. However, there was a significant interaction between sex and rs6888 on hyperlipidemia risk (p-interaction = 0.0321). With the male sex/CC genotype being the reference group, only the female sex/CT and T/T genotypes were closely associated with hyperlipidemia, with respective ORs of 1.153 (CI: 1.014-1.311) and 1.423 (CI: 1.056-1.917). Our data indicate that rs688 C/T and T/T genotypes may be associated with increased risk of hyperlipidemia in Taiwanese women. These findings may be relevant in lipid-modification therapy.

Near-perfect kinetic resolution of racemic p-chlorostyrene oxide by SlEH1, a novel epoxide hydrolase from Solanum lycopersicum with extremely high enantioselectivity.

An open reading frame of sleh1, a gene encoding for a novel epoxide hydrolase from Solanum lycopersicum (SlEH1), was amplified by RT-PCR and expressed in E. coli BL21(DE3). The substrate spectrum assay showed that E. coli/sleh1 had EH activities towards all tested substrates except for racemic (rac-) 5a, and the highest enantiomeric ratio (E > 200) towards rac-2a, retaining (R)-2a with 99.1% ees and 49.2% yields and affording (R)-2b with 89.8% eep and 46.7% yieldp. Besides, E. coli/sleh1 also hydrolyzed of rac-7a-9a with moderate regioselectivities, producing (S)- or (R)-7b-9b with 40.5-51.3% eep and 69.4-75.2% yieldp. The pH optimum and stability of the purified SlEH1 were 7.5 and at a range of 6.5-8.5, and it was thermostable at or below 40 °C. Its catalytic efficiency (kcatS/KmS = 7.49 mM-1 s-1) for (S)-2a was much higher than that for (R)-2a. The gram-scale kinetic resolution of 150 mM rac-2a was carried out by E. coli/sleh1 at 20 °C for 8 h, producing (R)-2a with 98.2% ees and 45.3% overall yields after purification by silica gel column chromatography. Furthermore, the source of extremely high enantioselectivity of SlEH1 towards rac-2a was analyzed by molecular docking simulations.

Substantially improving the enantioconvergence of PvEH1, a Phaseolus vulgaris epoxide hydrolase, towards m-chlorostyrene oxide by laboratory evolution.

BACKGROUND: Epoxide hydrolase can regioselectively catalyze the oxirane ring-opening hydrolysis of rac-epoxides producing the corresponding chiral diols. In our laboratory, a gene named pveh1 encoding an EH from Phaseolus vulgaris was cloned. Although the directed modification of PvEH1 was carried out, the mutant PvEH1Y3 showed a limited degree of enantioconvergence towards racemic (rac-) m-chlorostyrene oxide (mCSO). RESULTS: PvEH1 and PvEH1Y3 were combinatively subjected to laboratory evolution to further enhance the enantioconvergence of PvEH1Y3 towards rac-mCSO. Firstly, the substrate-binding pocket of PvEH1 was identified using a CAVER 3.0 software, and divided into three zones. After all residues in zones 1 and 3 were subjected to leucine scanning, two E. coli transformants, E. coli/pveh1Y149L and /pveh1P184L, were selected, by which rac-mCSO was transformed into (R)-m-chlorophenyl-1,2-ethanediol (mCPED) having 55.1% and 27.2% eep. Secondly, two saturation mutagenesis libraries, E. coli/pveh1Y149X and /pveh1P184X (X: any one of 20 residues) were created at sites Y149 and P184 of PvEH1. Among all transformants, both E. coli/pveh1Y149L (65.8% αS and 55.1% eep) and /pveh1P184W (66.6% αS and 59.8% eep) possessed the highest enantioconvergences. Finally, the combinatorial mutagenesis was conducted by replacements of both Y149L and P184W in PvEH1Y3, constructing E. coli/pveh1Y3Z2, whose αS reached 97.5%, higher than that (75.3%) of E. coli/pveh1Y3. In addition, the enantioconvergent hydrolysis of 20 mM rac-mCSO was performed by E. coli/pveh1Y3Z2, giving (R)-mCPED with 95.2% eep and 97.2% yield. CONCLUSIONS: In summary, the enantioconvergence of PvEH1Y3Z2 was successfully improved by laboratory evolution, which was based on the study of substrate-binding pocket by leucine scanning. Our present work introduced an effective strategy for the directed modification of enantioconvergence of PvEH1.

Multiple site-directed mutagenesis of a Phaseolus vulgaris epoxide hydrolase to improve its catalytic performance towards p-chlorostyrene oxide based on the computer-aided re-design.

To improve the activity and regioselectivity of a Phaseolus vulgaris epoxide hydrolase (PvEH3) towards p-chlorostyrene oxide (pCSO), the site-directed mutagenesis was conducted based on the computer-aided re-design. Firstly, seven single-site variants of a PvEH3-encoding gene (pveh3) were constructed as designed theoretically and expressed in E. coli BL21(DE3), respectively. One transformant, E. coli/pveh3G170E, had the higher EH activity towards racemic pCSO, while both E. coli/pveh3F187L and /pveh3P237L with enhanced regioselectivity coefficient αS values. Secondly, to combine their respective merits, the double- and triple-site variants, pveh3G170E/F187L, pveh3G170E/P237L and pveh3G170E/F187L/P237L, were also constructed. Among all E. coli transformants, E. coli/pveh3G170E/F187L/P237L simultaneously had the highest EH activity of 20.3 U/g wet cell and αS value of 95.2%, by which the hydrolysis of rac-pCSO enantioconvergently produced (R)-p-chlorophenylethane-1,2-diol with an enantiomeric excess of 93.2%. Furthermore, PvEH3G170E/F187L/P237L expressed in E. coli/pveh3G170E/F187L/P237L was purified. Its specific activity and catalytic efficiency towards rac-pCSO were 4.1 U/mg protein and 1.81 mM-1 s-1, which were 3.0- and 3.1-fold those of PvEH3. Finally, the molecular docking simulation analysis indicated that PvEH3G170E/F187L/P237L preferentially attacks the more hindered benzylic carbon of (S)-pCSO over PvEH3, which was consistent with their αS values measured experimentally.

Directed modification of l-LcLDH1, an l-lactate dehydrogenase from Lactobacillus casei, to improve its specific activity and catalytic efficiency towards phenylpyruvic acid.

To improve the specific activity and catalytic efficiency of l-LcLDH1, an NADH-dependent allosteric l-lactate dehydrogenase from L. casei, towards phenylpyruvic acid (PPA), its directed modification was conducted based on the semi-rational design. The three variant genes, Lcldh1Q88R, Lcldh1I229A and Lcldh1T235G, were constructed by whole-plasmid PCR as designed theoretically, and expressed in E. coli BL21(DE3), respectively. The purified mutant, l-LcLDH1Q88R or l-LcLDH1I229A, displayed the specific activity of 451.5 or 512.4 U/mg towards PPA, by which the asymmetric reduction of PPA afforded l-phenyllactic acid (PLA) with an enantiomeric excess (eep) more than 99%. Their catalytic efficiencies (kcat/Km) without d-fructose-1,6-diphosphate (d-FDP) were 4.8- and 5.2-fold that of l-LcLDH1. Additionally, the kcat/Km values of l-LcLDH1Q88R and l-LcLDH1I229A with d-FDP were 168.4- and 8.5-fold higher than those of the same enzymes without d-FDP, respectively. The analysis of catalytic mechanisms by molecular docking (MD) simulation indicated that substituting I229 in l-LcLDH1 with Ala enlarges the space of substrate-binding pocket, and that the replacement of Q88 with Arg makes the inlet of pocket larger than that of l-LcLDH1.

Duration-response association between exercise and HDL in both male and female Taiwanese adults aged 40 years and above.

BACKGROUND: Exercise is an important cardiovascular risk reducing therapy. OBJECTIVE: The aim of this study was to assess the relationship between weekly exercise duration and high-density lipoprotein cholesterol (HDL-c) in Taiwanese men and women. METHODS: Data were retrieved from the dataset of the national adult preventive medical services which is recorded under the Health Promotion Administration (HPA). The lipid profiles of 194528 eligible participants aged 40 years and above who completed a questionnaire on recent health behavior including smoking, drinking, exercise and other factors in 2014 were determined. Weekly exercise durations of 0.0, <2.5 and ≥2.5 hours were classified as no, below recommended and recommended, respectively. The relationship between exercise and HDL-c was determined using linear regression. RESULTS: After multivariate adjustments, a duration-response association existed between exercise and HDL-c (P-trend <0.0001) in both sexes. Weekly exercise durations of <2.5 and ≥2.5 hours were both positively associated with HDL-c (P <0.0001) in both sexes. However, the associations were stronger in males than females in both exercise groups. Smoking (P <0.05) and BMI (P <0.0001) were negatively associated while drinking was positively associated with HDL-c in both sexes. CONCLUSION: This study demonstrated a duration-response association between exercise and HDL-c. Exercise at durations below the minimum weekly recommendation of 2.5 hours was positively associated with HDL-c.

Exercise might prevent cirrhosis in overweight and obese adults.

BACKGROUND & AIMS: Exercise in overweight patients with liver disease has improved liver enzymes, insulin levels and quality of life. Scientific evidence is incomplete regarding the role of exercise in the prevention of cirrhosis. We investigated the effect of exercise on the occurrence of cirrhosis in obese and overweight adults. METHODS: Exercise was assessed using the 2012 Adult Preventive Medical Service dataset while cirrhosis was identified using the National Health Insurance Research Database. All participants were aged 40 years and older. Unconditional logistic regression was used to estimate the odds ratios for cirrhosis. RESULTS: Overall, 1586 overweight and 1525 obese adults were identified with cirrhosis. Weekly exercise >150 min was significantly protective for cirrhosis in obese men and women. However, exercise <150 min/wk was significantly protective only in men compared to women. For weekly exercise >150 mins, the odds ratio for cirrhosis in obese men and women was 0.701 (95% CI: 0.584-0.841) and 0.736 (95% CI: 0.562-0.964) respectively. The adjusted odds ratios in overweight men and women were 0.734 (95% CI: 0.622-0.866) and 0.503 (CI: 0.37-0.684). For weekly exercise <150 min/wk, overweight and obese men had odds ratios of 0.879 (CI: 0.0.788-0.98) and 0.874 (CI: 0.782-0.977) compared to 0.918 (95% CI: 0.778-1.083) and 0.916 (95% CI: 0.780-1.075) in overweight and obese women respectively. CONCLUSIONS: Moderate exercise might significantly prevent obese and overweight adults from developing cirrhosis. The benefits appear to be greater for persons who exceed the minimum recommendations of 150 min/wk.

Improving the temperature characteristics and catalytic efficiency of a mesophilic xylanase from Aspergillus oryzae, AoXyn11A, by iterative mutagenesis based on in silico design.

To improve the temperature characteristics and catalytic efficiency of a glycoside hydrolase family (GHF) 11 xylanase from Aspergillus oryzae (AoXyn11A), its variants were predicted based on in silico design. Firstly, Gly21 with the maximum B-factor value, which was confirmed by molecular dynamics (MD) simulation on the three-dimensional structure of AoXyn11A, was subjected to site-saturation mutagenesis. Thus, one variant with the highest thermostability, AoXyn11AG21I, was selected from the mutagenesis library, E. coli/Aoxyn11A G21X (X: any one of 20 amino acids). Secondly, based on the primary structure multiple alignment of AoXyn11A with seven thermophilic GHF11 xylanases, AoXyn11AY13F or AoXyn11AG21I-Y13F, was designed by replacing Tyr13 in AoXyn11A or AoXyn11AG21I with Phe. Finally, three variant-encoding genes, Aoxyn11A G21I, Aoxyn11A Y13F and Aoxyn11A G21I-Y13F, were constructed by two-stage whole-plasmid PCR method, and expressed in Pichia pastoris GS115, respectively. The temperature optimum (T opt) of recombinant (re) AoXyn11AG21I-Y13F was 60 °C, being 5 °C higher than that of reAoXyn11AG21I or reAoXyn11AY13F, and 10 °C higher than that of reAoXyn11A. The thermal inactivation half-life (t 1/2) of reAoXyn11AG21I-Y13F at 50 °C was 240 min, being 40-, 3.4- and 2.5-fold longer than those of reAoXyn11A, reAoXyn11AG21I and reAoXyn11AY13F. The melting temperature (T m) values of reAoXyn11A, reAoXyn11AG21I, reAoXyn11AY13F and reAoXyn11AG21I-Y13F were 52.3, 56.5, 58.6 and 61.3 °C, respectively. These findings indicated that the iterative mutagenesis of both Gly21Ile and Tyr13Phe improved the temperature characteristics of AoXyn11A in a synergistic mode. Besides those, the catalytic efficiency (k cat/K m) of reAoXyn11AG21I-Y13F was 473.1 mL mg-1 s-1, which was 1.65-fold higher than that of reAoXyn11A.