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BACKGROUND: The direct bioconversion of crude glycerol, a byproduct of biodiesel production, into 1,3-propanediol by microbial fermentation constitutes a remarkably promising value-added applications. However, the low activity of glycerol dehydratase, which is the key and rate-limiting enzyme in the 1,3-propanediol synthetic pathway, caused by crude glycerol impurities is one of the main factors affecting the 1,3-propanediol yield. Hence, the exploration of glycerol dehydratase resources suitable for crude glycerol bioconversion is required for the development of 1,3-propanediol-producing engineered strains. RESULTS: In this study, the novel glycerol dehydratase 2eGDHt, which has a tolerance against crude glycerol impurities from Klebsiella pneumoniae 2e, was characterized. The 2eGDHt exhibited the highest activity toward glycerol, with Km and Vm values of 3.42 mM and 58.15 nkat mg-1, respectively. The optimum pH and temperature for 2eGDHt were 7.0 and 37 °C, respectively. 2eGDHt displayed broader pH stability than other reported glycerol dehydratases. Its enzymatic activity was increased by Fe2+ and Tween-20, with 294% and 290% relative activities, respectively. The presence of various concentrations of the crude glycerol impurities, including NaCl, methanol, oleic acid, and linoleic acid, showed limited impact on the 2eGDHt activity. In addition, the enzyme activity was almost unaffected by the presence of an impurity mixture that mimicked the crude glycerol environment. Structural analyses revealed that 2eGDHt possesses more coil structures than reported glycerol dehydratases. Moreover, molecular dynamics simulations and site-directed mutagenesis analyses implied that the existence of unique Val744 from one of the increased coil regions played a key role in the tolerance characteristic by increasing the protein flexibility. CONCLUSIONS: This study provides insight into the mechanism for enzymatic action and the tolerance against crude glycerol impurities, of a novel glycerol dehydratase 2eGDHt, which is a promising glycerol dehydratase candidate for biotechnological conversion of crude glycerol into 1,3-PDO.

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Bauxite wastewater creates soil contamination and produces toxic effects on human health such as respiratory and skin rash problems. In this study, we investigated the phytoremediation ability of Jatropha curcas to remove bauxite wastewater from soil. Pot experiments were conducted to investigate the bauxite wastewater on the phytoremediation potential of J. curcas grown in contaminated soils. J. curcas exhibited a significant increase in plant growth leaf, root activity, plant height, and plant shoot when grown in bauxite contaminated soils compared with J. curcas grown in uncontaminated soils after 30 d treatment. Under bauxite exposure, a higher aluminium removal (88.5%) was observed in soils planted with J. curcas than unplanted soils (39.6%). The bioconcentration factor was also found to be 5.62, indicating that J. curcas have great tolerance and hyperaccumulator of aluminium under high aluminium concentrations and are capable of phytoextraction of soil contaminated with bauxite wastewater.

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OBJECTIVE: To identify a more popularized preparation protocol of leukocytes-rich platelet-rich plasma (L-PRP) for higher tolerance rate. METHODS: The peripheral blood samples of 76 volunteers (45.0 mL/case) were mixed with 5 mL sodium citrate injection for blood transfusion, and L-PRP was prepared by twice centrifugations. All blood samples were divided into three groups according to the parameters of twice centrifugation: experimental group A (12 cases, 400× g, 10 minutes for the first time and 1 100× g, 10 minutes for the second time), experimental group B (27 cases, 800× g, 10 minutes for the first time and 1 100× g, 10 minutes for the second time), and control group (37 cases, 1 360× g, 10 minutes for the first time and 1 360× g, 10 minutes for the second time). The platelet recovery rate and platelet and leukocyte enrichment coefficient of L-PRP in each group were calculated and compared. RESULTS: After removal of abnormal blood samples (platelet recovery rate was more than 100% or white thrombus), the remaining 55 cases were included in the statistical analysis, including 10 cases in experimental group A, 21 cases in experimental group B, and 24 cases in control group. The platelet enrichment coefficient and platelet recovery rate of experimental group B were significantly higher than those of experimental group A and control group ( P<0.05); there was no significant difference between experimental group A and control group ( P>0.05). There was no significant difference in leukocyte enrichment coefficient between experimental groups A, B, and control group ( P>0.05). CONCLUSION: The preparation quality of PRP is affected by various factors, including centrifugal force, centrifugal time, temperature, and operation process, etc. Twice centrifugation (800× g, 10 minutes for the first time and 1 100× g, 10 minutes for the second time) is an ideal and feasible centrifugation scheme, which can obtain satisfactory platelet recovery rate and enrichment coefficient with thicker buffy coat, which can reduce the fine operation requirements for operators, improve the fault tolerance rate and generalization.

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Transgenic engineering is an effective way for plants to obtain strong degradation or detoxification abilities to target pollutants. Acetochlor is an important and widely used herbicide, however, its residue is persistent in soil and is toxic to humans and rotation crops. In this study, the degradation ability and tolerance to acetochlor of transgenic Arabidopsis thaliana synthesizing the oxygenase component, CndA, of the bacterial acetochlor N-dealkylase system, CndABC, were investigated. Two transgenic plants, including a cytoplasm transformant, in which the CndA was located in the cytoplasm, and a chloroplast transformant, in which the CndA was located in the chloroplast, were constructed. The cytoplasm transformant acquired only weak acetochlor degradation activity and displayed little acetochlor tolerance. In contrast, the chloroplast transformant exhibited high degradation efficiency and strong tolerance to acetochlor; it could transform 94.3% of 20 µM acetochlor in water within 48 h and eliminate 80.2% of 5 mg/kg acetochlor in soil within 30 d. The metabolite of acetochlor N-dealkylation catalyzed by CndA, 2-chloro-N-(2-methyl-6-ethylphenyl)acetamide (CMEPA), could be released outside the cells by chloroplast transformant and further degraded by indigenous microorganisms in the soil. This study provides an effective strategy for the phytoremediation of acetochlor residue in water and soil.

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FeOCl Fenton-like catalyst has drawn much attention due to its high catalytic activity. Nevertheless, the potential application of FeOCl is significantly hindered by the sluggish reduction kinetics of Fe3+ to active Fe2+. Here, we report that the incorporation of Fe - O-Mo electron mediator into FeOCl via forming a FeOCl/MoS2 composite can facilitate the Fe2+ regeneration through the oxidation of Mo4+ to Mo6+, which boosts the hydroxyl radicals yields, thus leading to a significantly improved catalytic performance. The removal efficiency of methylene blue (MB, 50 mg L-1) achieves ∼100% within 2 min. with low dosage of FeOCl/MoS2 (0.2 g L-1) and H2O2 (0.6 mM). FeOCl/MoS2 not only has broad working pH range (∼3 - 9) and high salinity tolerance (100 mM), but also capable to degrade various organic pollutants. For practical application, the fabricated FeOCl/MoS2 membrane effectively degrades continuous MB flow. This study demonstrates that incorporating an electron mediator is an effective way to improve the catalytic performance of heterogeneous Fenton-like catalysts.

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Objective: To identify a more popularized preparation protocol of leukocytes-rich platelet-rich plasma (L-PRP) for higher tolerance rate. Methods: The peripheral blood samples of 76 volunteers (45.0 mL/case) were mixed with 5 mL sodium citrate injection for blood transfusion, and L-PRP was prepared by twice centrifugations. All blood samples were divided into three groups according to the parameters of twice centrifugation: experimental group A (12 cases, 400× g, 10 minutes for the first time and 1 100× g, 10 minutes for the second time), experimental group B (27 cases, 800× g, 10 minutes for the first time and 1 100× g, 10 minutes for the second time), and control group (37 cases, 1 360× g, 10 minutes for the first time and 1 360× g, 10 minutes for the second time). The platelet recovery rate and platelet and leukocyte enrichment coefficient of L-PRP in each group were calculated and compared. Results: After removal of abnormal blood samples (platelet recovery rate was more than 100% or white thrombus), the remaining 55 cases were included in the statistical analysis, including 10 cases in experimental group A, 21 cases in experimental group B, and 24 cases in control group. The platelet enrichment coefficient and platelet recovery rate of experimental group B were significantly higher than those of experimental group A and control group ( P0.05). There was no significant difference in leukocyte enrichment coefficient between experimental groups A, B, and control group ( P>0.05). Conclusion: The preparation quality of PRP is affected by various factors, including centrifugal force, centrifugal time, temperature, and operation process, etc. Twice centrifugation (800× g, 10 minutes for the first time and 1 100× g, 10 minutes for the second time) is an ideal and feasible centrifugation scheme, which can obtain satisfactory platelet recovery rate and enrichment coefficient with thicker buffy coat, which can reduce the fine operation requirements for operators, improve the fault tolerance rate and generalization.

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ABSTRACTHip fracture rehabilitation has two streams: high tolerance short duration (HTSD) and low tolerance long duration (LTLD). This study examined patient characteristics and outcomes in HTSD and LTLD associated with length of stay (LOS) and discharge destination. We retrospectively examined patients' medical charts following hip fracture surgery and collected demographic, functional, and health characteristics. A statistical analysis was done to describe the differences between HTSD (n = 73) and LTLD (n = 57) patient characteristics and their relationship with LOS and discharge destination. Those in LTLD were significantly older, less independent with prefracture bathing and instrumental activities of daily living, had lower Functional Independence Measure (FIM) admission scores, and more co-morbidities. Higher FIM motor score on admission in HTSD and greater change in FIM total score in LTLD was significantly correlated with discharge home. Diabetes in LTLD and lower total admission FIM in HTSD was significantly associated with increased LOS.

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