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(R)-2-hydroxy-3-phenylpropionic acid (PLA) is an ideal antimicrobial compound with broad-spectrum activity against a wide range of Gram-positive bacteria, some Gram-negative bacteria, and fungi. We studied the bioconversion of phenylpyruvate (PPA) to PLA using whole recombinant Escherichia coli cells in a series of buffer/organic solvent systems. Octane was found to be the best organic solvent. The optimum volume ratio of the water phase to the n-octane phase, conversion temperature, substrate concentration, and cell concentration were 6:4, 40 °C, 12.5 g/L, and 30 g/L wet cells, respectively. Under the optimized conditions, the average PLA productivity in the aqueous/n-octane system was 30.69% higher than that in the aqueous system, and 32.31 g/L PLA was obtained with the use of a stirred reactor (2-L scale). Taken together, our findings indicated that PLA biosynthesis was more efficient in an aqueous/n-octane biphasic system than in a monophasic aqueous system. The proposed biphasic system is an effective strategy for enhancing PLA yield and the biosynthesis of its analogues. [ABSTRACT FROM AUTHOR]

People living near the equator more easily obtain adequate 25-hydroxyvitamin D [25(OH)D]. However, studies indicated that vitamin D deficiency is common even in the sunniest areas. We mainly analyzed the vitamin D status and dietary patterns of men highly exposed to sunlight, and investigated the correlation of vitamin D status with dietary patterns and time for outdoor work or activities. The average vitamin D levels among men highly exposed to sunlight was sufficient, but parts of the population had vitamin D deficiency or insufficiency. Long-term vitamin D deficiency may correlate with obesity and hypertension. These results provide a scientific basis for future research. [ABSTRACT FROM AUTHOR]

Dietary pattern has been revealed to be associated with metabolic syndrome. However, the association was not well documented in Chinese due to the complexity of Chinese foods. We mainly assessed the dietary patterns and examined their effects on metabolic syndrome among Chinese adults. Four dietary patterns including ‘Refined Grains & Vegetables’ Pattern, ‘Dairy & Eggs’ Pattern, ‘Organ Meat & Poultry’ Pattern, and ‘Coarse Grains & Beans’ Pattern were extracted. ‘Dairy & Eggs’ Pattern was associated with a decreased odds of metabolic syndrome in women, and ‘Coarse Grains & Beans’ Pattern was associated with a decreased odds of hypertension in men. These results provided a scientific basis for future research and dietary guideline perfection. [ABSTRACT FROM AUTHOR]

To estimate the productivity of coal-bed methane (CBM), the premise is the effective description of CBM migration mechanism. The authors have developed a new fracture-permeability relative model by coupling the general Kozeny-Carman equation and the classical cubic law of fracture flow, which takes into account the effects of external and internal friction. In the model developed, the hydraulic tortuosity is responsible for the internal friction, and the surface tortuosity for external friction effect, which is defined as the area ratio between cleat rough surface and the projected one on the macro-flow plane. Consequently, the authors modelled the cleats composed of rough surfaces characterized by the theory of fractal geometry, and simulated the CBM flow through them by lattice Boltzmann method. In addition, the authors investigated the effects, such as surface fractal dimension, absolute surface roughness, as well as the relative surface roughness, on the CBM flow. Based on the results obtained, the validity of the newly derived fracture-permeability relationship is verified by comparative analyses. The results reveal that the newly developed model accounting for the effects of external and internal friction, can effectively describe the migration law of CBM through rough cleats. [ABSTRACT FROM AUTHOR]

Zygentoma occupies a key evolutionary position for understanding the evolution of insect metamorphosis but has received little attention in terms of genetic analysis. To develop functional genomic studies in this insect, we evaluated five candidate internal reference genes for quantitative RT-PCR (qPCR) studies from Thermobia domestica, a representative species of Zygentoma, including Actin 5C (Actin5C), Elongation factor-1 alpha (EF1A), Ribosome protein S26 (RPS26), Ribosome protein L32 (RPL32), and Superoxide dismutase 2 (SOD2), at different developmental stages, in various body parts, and under dsRNA microinjection and starvation stresses, using four algorithms (delta Ct, geNorm, NormFinder and BestKeeper) and a comparative algorithm (RefFinder). Specific suitable reference genes were recommended across specific experimental conditions, and the combination of RPS26 and RPL32 was appropriate for all tested samples. Employing our selected reference gene combination, we investigated the gene expression pattern of Myoglianin (Myo), a crucial gene-regulating insect metamorphosis, in ametabolous T. domestica, and demonstrated the efficiency of RNA interference (RNAi) in firebrat nymphs. This study provides a basis for reliable quantitative studies of genes and greatly benefits evolutionary and functional genomics studies in Zygentoma. [ABSTRACT FROM AUTHOR]

Gene PA4980 from Pseudomonas aeruginosa encodes a putative enoyl-coenzyme A hydratase/isomerase that is associated with the function of the biofilm dispersion-inducing signal molecule cis-2-decenoic acid. To elucidate the role of PA4980 in cis-2-decenoic acid biosynthesis, we reported the crystal structure of its protein product at 2.39 Å. The structural analysis and substrate binding prediction suggest that it acts as a monofunctional enoyl-coenzyme A isomerase, implicating an alternative pathway of the cis-2-decenoic acid synthesis.

Objective: To explore the secular trends of cesarean delivery and cesarean delivery on maternal request (CDMR) among primiparous women with singleton pregnancy in Southern and Northern China., Methods: The Perinatal Healthcare Surveillance System was established in 26 counties/cities of 3 Chinese provinces since 1993. A total of 1 317 774 primiparous women with singleton pregnancy were monitored through the system during the 1993 - 2010 period. Chi-square tests were performed to assess the linear trends in the prevalence of cesarean delivery and CDMR., Results: During the 18-year period, 496 054 cesarean deliveries and 129 219 CDMRs were identified. The prevalence rates of cesarean delivery and CDMR were 37.6% and 10.0% respectively. CDMR accounted for 26.0% of all cesarean births. The prevalence of cesarean delivery increased from 29.4% during the 1993 - 1995 period to 58.7% during the 2006 - 2010 in Southern urban area, from 18.2% to 58.3% in Southern rural area and from 4.3% to 49.5% in Northern rural area. The prevalence of CDMR increased by 34 folds from 0.6% during the 1993 - 1995 period to 21.3% during the 2006 - 2010 period in Southern urban area, by 40 folds from 0.6% to 24.4% in Southern rural area and by 44 folds from 0.6% to 27.3% in Northern rural area. The proportions of CDMR in all cesarean deliveries significantly increased in all three regions. Women aged over 30 years, overweight and well-educated were more likely to experience a cesarean delivery including CDMR., Conclusion: The Chinese prevalence rates of cesarean delivery and CDMR increased dramatically during the 1993 - 2010 period and ranked the highest in the world by 2010. And CDMR became a non-negligible component in all cesarean sections.

Objective: To investigate the existence of functional neuroreceptors in peri-implant bone tissue and to test the peri-implant neural feedback pathway reconstruction and its influential factors., Methods: Three beagle dogs were involved in this study. After the extraction of 3 premolars and 1 molar of the bilateral mandible, 27 implants were placed immediately or delayed. The implants were loaded for 3 - 6 months, then sensory nerve action potential (SNAP) tests were performed. The stimulating electrode was connected to the implant or natural tooth. The recording electrode was fixed near the inferior alveolar nerve (IAN) to record the latency period and amplitude of SNAP. The specimens with peri-implant bone tissues were taken and examined by immunohistochemistry., Results: SNAP of IAN could be recorded following stimulations to natural teeth and implants. The differences in SNAP amplitudes between natural teeth [(44.04 +/- 6.23) microV] and all implant groups were statistically significant (P < 0.01). Free nerve endings and nerve tract were found in the peri-implant bone tissue, but much less than those in periodontal membrane. Some nerve fibers were directly connected with implant surface., Conclusions: Functional neuroreceptors, though much less than that of natural tooth, exist in peri-implant bone tissue. Surgical methods and loading time do not have obvious influences on peri-implant neural feedback pathway reconstruction.

This review focus on the characters of patients with cleft palate and micrognathia, the pathologic and physiological changes of this malformation and their influence on the patients, the risk factors of cleft palate repair, the indication and the outcome of palatoplasty. It is aimed to give a guideline for the optimal timing of cleft palate repair and the reduction of the risk factors,for these unique patients.