164 research outputs found
Effect of Electrical Current Stimulation on the Metabolic Flux Distribution of Corynebacterium crenatum under Anaerobic Conditions
The effect of electrical current stimulation on the fermentation characteristics of Corynebacterium crenatum under anaerobic conditions was investigated, and the impacting mechanism was discussed by calculating metabolic fluxes and measuring gene expression levels. It turned out that electrical current stimulation greatly contributed to glucose metabolism and succinic acid synthesis. Applying an electric current of −5 mA increased the glucose consumption rate, the concentration of succinic acid in the fermentation broth, the yield of succinic acid, the metabolic flux in the pentose phosphate pathway (HMP), and intracellular NADH/NAD+ ratio by 27.4%, 109.4%, 62.5%, 150.6% and 30.8% respectively, compared with the control group (0 mA). The results of metabolic flux and key enzyme gene expression levels indicated that glucose-6-phosphate was the key node that could influence the production of succinic acid. Electrical current stimulation up-regulated the expression levels of the glucose-6-phosphate dehydrogenase gene (zwf) and the phosphoenolpyruvate carboxylase gene (pepc), and increased the metabolic fluxes in the HMP and succinic acid biosynthesis pathway, thereby increasing the production of succinic acid. These results support the combined application of electrochemistry and fermentation
Placental expression of AChE, α7nAChR and NF-κB in patients with preeclampsia
Objectives: This study aimed to investigate placental expression of AChE, α7nAChR and NF-κB in patients with preeclampsia and discuss about its clinical significance.
Material and methods: mRNA expression levels of acetylcholine (AChE), alpha-7 nicotinic acetylcholine receptor (α7nAChR) and nuclear factor-kB (NF-κB) in placenta were detected by qRT-PCR, and protein levels were determined by immunohisÂtological analysis and Western Blot in 35 women with preeclampsia (including 20 cases of mild preeclampsia and 15 cases of severe preeclampsia) and 30 cases in control group, respectively.
Results: The expression of AChE mRNA and protein in placenta increased significantly in patients with preeclampsia compared with the control group (p < 0.01). It was lower in patients with severe preeclampsia than in patients with mild preeclampsia (p < 0.05). The expression of α7nAChR mRNA and protein in placenta decreased significantly in patients with preeclampsia compared with the control group (p < 0.01). However, the expression of α7nAChR mRNA and protein in patients with severe preeclampsia was higher than that in patients with mild preeclampsia, without significant difference(p > 0.05). The expression of NF-κB protein in placenta decreased significantly in patients with preeclampsia compared with the control group(p < 0.01). It was higher in patients with severe preeclampsia than in patients with mild preeclampsia (p < 0.05), but there was no significant difference between preeclampsia group and control group in the expression of NF-κB mRNA in placenta (p > 0.05). The results of Western blotting assay were consistent with those of immunohistochemistry.
Conclusions: Abnormal expression of AChE, α7nAChR and NF-κB in placenta may be associated with preeclampsia. ChoÂlinergic anti-inflammatory pathway may play an important role in the pathogenesis of preeclampsia
NaoXinTong Inhibits the Development of Diabetic Retinopathy in d
Buchang NaoXinTong capsule (NXT) is a Chinese Materia Medica standardized product extracted from 16 Chinese traditional medical herbs and widely used for treatment of patients with cerebrovascular and cardiovascular diseases in China. Formation of microaneurysms plays an important role in the development of diabetic retinopathy. In this study, we investigated if  NXT can protect diabetic mice against the development of diabetic retinopathy. The db/db mice (~6 weeks old), a diabetic animal model, were divided into two groups and fed normal chow or plus NXT for 14 weeks. During the treatment, fasting blood glucose levels were monthly determined. After treatment, retinas were collected to determine retinal thickness, accumulation of carbohydrate macromolecules, and caspase-3 (CAS-3) expression. Our results demonstrate that administration of NXT decreased fasting blood glucose levels. Associated with the decreased glucose levels, NXT blocked the diabetes-induced shrink of multiple layers, such as photoreceptor layer and outer nuclear/plexiform layers, in the retina. NXT also inhibited the diabetes-induced expression of CAS-3 protein and mRNA, MMP-2/9 and TNFα mRNA, accumulation of carbohydrate macromolecules, and formation of acellular capillaries in the retina. Taken together, our study shows that NXT can inhibit the development of diabetic retinopathy and suggests a new potential application of NXT in clinic
Mineralogical characterization of manganese oxide minerals of the Devonian Xialei manganese deposit
The Guangxi Zhuang Autonomous Region is an important manganese ore district in Southwest China, with manganese ore resource reserves accounting for 23% of the total manganese ore resource reserves in China. The Xialei manganese deposit (Daxin County, Guangxi) is the first super-large manganese deposit discovered in China. The Mn oxide in the supergene oxidation zone of the Xialei deposit was characterized using scanning electron microscopy (SEM), energy spectrometer (EDS), transmission electron microscopy (TEM, HRTEM), and X-ray diffraction analysis (XRD). The Mn oxides have a gray-black/steel-gray color, a semi-metallic-earthy luster, and appear as oolitic, pisolitic, banded, massive, and cellular textures. Scanning electron microscopy images show that the manganese oxide minerals are present as fine-spherical particles with an earthy surface. TEM and HRTEM indicate the presence of oriented bundled and staggered nanorods, and nanopores between the crystals. The Mn oxide ore can be classified into two textural types: (1) oolitic and pisolitic (often with annuli) Mn oxide, and (2) massive Mn oxide. Pyrolusite, cryptomelane, and hollandite are the main Mn oxide minerals. The potassium contents of cryptomelane and pyrolusite are discussed. The unit cell parameters of pyrolusite are refined
Effects of aging and macrophages on mice stem Leydig cell proliferation and differentiation in vitro
BackgroundTestosterone plays a critical role in maintaining reproductive functions and well-beings of the males. Adult testicular Leydig cells (LCs) produce testosterone and are generated from stem Leydig cells (SLCs) during puberty through adulthood. In addition, macrophages are critical in the SLC regulatory niche for normal testicular function. Age-related reduction in serum testosterone contributes to a number of metabolic and quality-of-life changes in males, as well as age-related changes in immunological functions. How aging and testicular macrophages may affect SLC function is still unclear.MethodsSLCs and macrophages were purified from adult and aged mice via FACS using CD51 as a marker protein. The sorted cells were first characterized and then co-cultured in vitro to examine how aging and macrophages may affect SLC proliferation and differentiation. To elucidate specific aging effects on both cell types, co-culture of sorted SLCs and macrophages were also carried out across two ages.ResultsCD51+ (weakly positive) and CD51++ (strongly positive) cells expressed typical SLC and macrophage markers, respectively. However, with aging, both cell types increased expression of multiple cytokine genes, such as IL-1b, IL-6 and IL-8. Moreover, old CD51+ SLCs reduced their proliferation and differentiation, with a more significant reduction in differentiation (2X) than proliferation (30%). Age matched CD51++ macrophages inhibited CD51+ SLC development, with a more significant reduction in old cells (60%) than young (40%). Crossed-age co-culture experiments indicated that the age of CD51+ SLCs plays a more significant role in determining age-related inhibitory effects. In LC lineage formation, CD51+ SLC had both reduced LC lineage markers and increased myoid cell lineage markers, suggesting an age-related lineage shift for SLCs.ConclusionThe results suggest that aging affected both SLC function and their regulatory niche cell, macrophages
Comprehensive Evaluation of Tea Cultivars Suitable for Matcha Production Using Multivariate Statistical Analysis
Matcha was prepared from 36 tea cultivars grown in the same tea garden according to the shading requirements for fresh leaves to be used for the production of matcha and its 11 quality indexes such as sensory quality, major physicochemical properties and chroma values were analyzed. In order to select tea cultivars suitable for the manufacturing of matcha, a comprehensive evaluation model of matcha quality was established by cluster analysis (CA), principal component analysis (PCA) and multiple linear regression analysis. The CA results showed that the 36 cultivars could be divided into three groups. Matcha from group I had the best quality with green color, fresh and mellow taste, and low phenol/ammonia ratio. Matcha from group II had high phenol/ammonia ratio and strong astringent taste. Matcha from Group III, consisting of etiolated and albino cultivars, had poor color and aroma quality. The PCA results showed that the cumulative contribution rate of the first five principal components was 88.152%. Comprehensive evaluation of matcha using the evaluation function constructed based on the first five principal components showed that the top 10 cultivars were Zhongcha 102, Taicha 12, Zhongcha 108, Fuding Dahao, Meizhan, Fuding Dabai, Fuyun 6, Zi Mudan, Maolv and Yingshuang. The model describing the relationship between sensory quality and physicochemical properties established by multiple linear regression analysis was as follows: y = 3.167|a*| + 46.850 (R2 = 0.710, P < 0.001). The scores of matcha cultivars evaluated by this model were highly consistent with the comprehensive evaluation results based on principal components, indicating that the a* value of dried tea could be used as a representative index to evaluate the quality of matcha. The results of this study can provide a reference for evaluating the suitability of tea cultivars for matcha manufacturing
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Understanding Research Data Practices of Civil and Environmental Engineering Graduate Students
Research data management is essential for high-quality reproducible research, yet relatively little is known about how research data management is practiced by graduate students in Civil and Environmental Engineering (CEE). Prior research suggests that faculty in CEE delegate research data management to graduate students, prompting this investigation into how graduate students practice data management. This study uses semi-structured interviews and qualitative content analysis to explore how CEE graduate students work with data and practice data management in their research, as well as what resources and support would meet their needs. Many respondents touched on data collection, data management, disseminating research outputs, and collaboration and learning in their interviews. Several themes emerged from the interviews: data quality as a concern, as many CEE graduate students rely on secondary data for research; a gap between values and enacted practices; a connection between disseminating data and reproducibility; and a reliance on peer and self-directed learning for data management education. Based on these themes, the study recommends strategies for librarians and others on campus to better support CEE graduate student research data practices.
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