24 research outputs found

    Aberrant Cerebral Activity in Early Postmenopausal Women: A Resting-State Functional Magnetic Resonance Imaging Study

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    Background: Early postmenopausal women frequently suffer from cognitive impairments and emotional disorders, such as lack of attention, poor memory, deficits in executive function and depression. However, the underlying mechanisms of these impairments remain unclear.Method: Forty-three early postmenopausal women and forty-four age-matched premenopausal controls underwent serum sex hormone analysis, neuropsychological testing and resting-state functional magnetic resonance imaging (rs-fMRI). Degree centrality (DC) analysis was performed to confirm the peak points of the functionally abnormal brain areas as the centers of the seeds. Subsequently, the functional connectivity (FC) between these abnormal seeds and other voxels across the whole brain was calculated. Finally, the sex hormone levels, neuroimaging indices and neuropsychological data were combined to detect potential correlations.Results: Compared with the premenopausal controls, the early postmenopausal women exhibited significantly higher serum follicle-stimulating hormone (FSH) levels, more severe climacteric and depressive symptoms, worse sleep quality and more extensive cognitive impairments. Concurrently, the neuroimaging results showed elevated DC values in the left amygdala (AMYG.L), reduced DC values in the left middle occipital gyrus (MOG.L) and right middle occipital gyrus (MOG.R). When we used the AMYG.L as the seed point, FC with the left insula (INS.L), bilateral prefrontal cortex (PFC) and right superior frontal gyrus (SFG.R) was increased; these regions are related to depressive states, poor sleep quality and decreased executive function. When bilateral MOG were used as the seed points, FC with left inferior parietal gyrus (IPG.L), this area closely associated with impaired memory, was decreased.Conclusion: These results illuminated the regional and network-level brain dysfunction in early postmenopausal women, which might provide information on the underlying mechanisms of the different cognitive impairments and emotional alterations observed in this group

    Aberrant Brain Function in Active-Stage Ulcerative Colitis Patients: A Resting-State Functional MRI Study

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    Background: Patients with ulcerative colitis (UC) usually display cognitive impairments, such as memory loss, attention deficits, and declining executive functions, particularly during the active stage of the disease. However, the potential neurological mechanisms of these symptoms remain unclear.Method: Forty-one patients with mildly to moderately active UC, as well as 42 matched healthy controls, were recruited for an examination using psychological scales, cognitive function tests and resting-state functional magnetic resonance imaging (rs-fMRI). Seed points were identified via analysis of amplitude of low-frequency fluctuation (ALFF), and functional connectivity (FC) was calculated between these seed regions and other voxels in the whole brain. Correlation analyses were performed among clinical indexes, neuropsychological assessments and neuroimaging data.Result: Compared with the healthy controls, patients with UC exhibited lower ALFF values in the bilateral hippocampal/parahippocampal (HIPP/ParaHIPP) region and higher ALFF values in the left posterior cingulate cortex (PCC.L) and left middle frontal gyrus (MFG.L). With HIPP/ParaHIPP as the seed point, the strengths of the FC in the bilateral middle frontal gyri (MFG), anterior cingulate cortex (ACC), and left caudate nucleus (CAU.L) increased; using the PCC.L as the seed point, the strengths of the FC in the middle cingulate cortex (MCC) and the left angular gyrus (AUG.L) increased. These abnormal brain regions were mainly located in the limbic system. By analyzing the correlations between these brain regions and behavioral data, we observed a close correlation between decreased HIPP/ParaHIPP activity and memory loss; increased PCC activity and strength of FC with the AUG.L were related to dysfunction of executive function and attention network in patients with UC.Conclusion: Based on these results, the limbic lobe might be the core of the brain-gut axis (BGA) and play an important role in cognitive impairments, suggesting potential mechanisms for cognitive impairment in patients with UC in the active stage of the disease

    Cassava genome from a wild ancestor to cultivated varieties

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    Cassava is a major tropical food crop in the Euphorbiaceae family that has high carbohydrate production potential and adaptability to diverse environments. Here we present the draft genome sequences of a wild ancestor and a domesticated variety of cassava and comparative analyses with a partial inbred line. We identify 1,584 and 1,678 gene models specific to the wild and domesticated varieties, respectively, and discover high heterozygosity and millions of single-nucleotide variations. Our analyses reveal that genes involved in photosynthesis, starch accumulation and abiotic stresses have been positively selected, whereas those involved in cell wall biosynthesis and secondary metabolism, including cyanogenic glucoside formation, have been negatively selected in the cultivated varieties, reflecting the result of natural selection and domestication. Differences in microRNA genes and retrotransposon regulation could partly explain an increased carbon flux towards starch accumulation and reduced cyanogenic glucoside accumulation in domesticated cassava. These results may contribute to genetic improvement of cassava through better understanding of its biology

    Studies on separation and properties of lumbrokinase in pheretima praepinguis

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    In order to separate lumbrokinase in Pheretima praepinguis and to study the enzymatic properties, with Pheretima praepinguis as material, lumbrokinase was separated with the salting out method. Lumbrokinase activity was measured with casein medium plate method. The effect of pH and temperature on lumbrokinase activity was studied. The activity of lumbrokinase separated from Pheretima praepinguis was relatively high. Lumbrokinase activity in neutral or slightly alkaline environment was higher. Lumbrokinase had tolerance ability to high temperature, with highly enzymatic activity under 60° and wide range of temperature adaptation

    Effects of Nutrient Input on Soil Nitrogen Cycle in Winter in the Alpine Zone

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    Microbial activity is rapidly reduced due to the decrease in temperature, but does not completely cease in the cold season. The snowpack in late winter insulates the soil and further increases soil temperature, allowing microbes to remain active and inducing a shift in the nature of N processing in alpine areas. Microbes need both carbon (C) and nitrogen (N) for their growth and metabolism and the scarcity of either will limit their activity. So soil available N pools and N cycling were closely linked to the C and N of the soil. Many previous studies showed the different results in different regions. Some of the results were considered to be C limited, some considered to be N limited, and also some considered to have little impact. However, which factor limited soil microbes and controlled soil N mineralization was not clear in the alpine belt of the eastern Qinghai Tibet Plateau. In present study, the effects of litter addition in situ and nutrient factors input in laboratory on soil mineral N pools and N mineralization in the eastern Qinghai Tibet Plateau were explored. A significant decrease in soil MBN content, NH4+-N content, increase in soil NO3-N content and net N mineralization, and no change in DON contents were observed with litter input. Direct input of C in laboratory decreased mineral N pools, while mineral N contents increased when N was added. The results suggested that the soil N cycling was influenced by the addition of available C, and the C-limitation occurs in winter in the Eastern Qinghai Tibet Plateau

    Studies on separation and properties of lumbrokinase in <i>Pheretima praepinguis</i>

    No full text
    The purpose of this study was to separate lumbrokinase in Pheretima praepinguis and examine its enzymatic properties. With P. praepinguis as material, lumbrokinase was separated with the salting out method. Lumbrokinase activity was measured with casein medium plate method. Effect of pH and temperature on lumbrokinase activity was studied. Results of lumbrokinase separated from P. praepinguis was relatively high. Lumbrokinase activity in neutral or slightly alkaline environment was higher. Lumbrokinase had tolerance ability to high temperature, with highly enzymatic activity under 60°C and wide range of temperature adaptation.

    Studies on separation and properties of lumbrokinase in Pheretima praepinguis

    No full text
    The purpose of this study was to separate lumbrokinase in Pheretima praepinguis and examine its enzymatic properties. With P. praepinguis as material, lumbrokinase was separated with the salting out method. Lumbrokinase activity was measured with casein medium plate method. Effect of pH and temperature on lumbrokinase activity was studied. Results of lumbrokinase separated from P. praepinguis was relatively high. Lumbrokinase activity in neutral or slightly alkaline environment was higher. Lumbrokinase had tolerance ability to high temperature, with highly enzymatic activity under 60°C and wide range of temperature adaptation

    High lymphatic vessel density and presence of lymphovascular invasion both predict poor prognosis in breast cancer

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    Abstract Background Lymphatic vessel density and lymphovascular invasion are commonly assessed to identify the clinicopathological outcomes in breast cancer. However, the prognostic values of them on patients’ survival are still uncertain. Methods Databases of PubMed, Embase, and Web of Science were searched from inception up to 30 June 2016. The hazard ratio with its 95% confidence interval was used to determine the prognostic effects of lymphatic vessel density and lymphovascular invasion on disease-free survival and overall survival in breast cancer. Results Nineteen studies, involving 4215 participants, were included in this study. With the combination of the results of lymphatic vessel density, the pooled hazard ratios and 95% confidence intervals were 2.02 (1.69–2.40) for disease-free survival and 2.88 (2.07–4.01) for overall survival, respectively. For lymphovascular invasion study, the pooled hazard ratios and 95% confidence intervals were 1.81 (1.57–2.08) for disease-free survival and 1.64 (1.43–1.87) for overall survival, respectively. In addition, 29.56% (827/2798) of participants presented with lymphovascular invasion in total. Conclusions Our study demonstrates that lymphatic vessel density and lymphovascular invasion can predict poor prognosis in breast cancer. Standardized assessments of lymphatic vessel density and lymphovascular invasion are needed
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