96 research outputs found
Hierarchically assembled tubular shell-core-shell heterostructure of hybrid transition metal chalcogenides for high-performance supercapacitors with ultrahigh cyclability
Pseudo-capacitive transition metal chalcogenides have recently received considerable attention as a promising class of materials for high performance supercapacitors (SCs) due to their superior intrinsic conductivity to circumvent the limitations of corresponding transition metal oxides with relatively poor conductivity. However, the important challenge associated with the utilization of such high-capacitive electrode materials is the development of desirably structured electrode materials, enabling efficient and rapid Faradaic redox reactions and ultra long-term cycling. Here, we propose a hierarchically integrated hybrid transition metal (Cu-Ni) chalcogenide shell-core-shell (HTMC-SCS) tubular heterostructure using a facile bottom-up synthetic approach. The resultant HTMC-SCS electrode exhibits a high volumetric capacitance of 25.9 F cm−3 at a current density of 2 mA cm−2. Furthermore, asymmetric SCs based on an HTMC-SCS heterostructured electrode demonstrate a high power density (770 mW cm−3) and an energy density (2.63 mWh cm−3) as well as an ultrahigh reversible capacity with a capacitance retention of 84% and a long-term cycling stability of over 10000 cycles. Based on experimental results and density functional theory calculations, these remarkably improved electrochemical features are discussed and explained in terms of the unique combination of the conductive CuS core and active NiS shell materials, hierarchical tubular open geometry with nanoscale inner/outer shell structure, and mechanical stress-mitigating interlayer on shell-core-shell interface, allowing highly reversible and efficient electrochemical redox processes coupled with fast charge transfer kinetics and an electrochemically stable structure
Low Densities of Serotonin and Peptide YY Cells in the Colon of Patients with Irritable Bowel Syndrome
Background The gut hormones are important in regulating gastrointestinal motility. Disturbances in gastrointestinal motility have been reported in patients with irritable bowel syndrome (IBS). Reduced endocrine cell density, as revealed by chromogranin A, has been reported in the colon of IBS patients. Aims To investigate a possible abnormality in the colonic endocrine cells of IBS patients. Methods A total of 41 patients with IBS according to Rome Criteria III and 20 controls were included in the study. Biopsies from the right and left colon were obtained from both patients and controls during colonoscopy. The biopsies were immunostained for serotonin, peptide YY (PYY), pancreatic polypeptide (PP), entroglucagon, and somatostatin cells. Cell densities were quantified by computerized image analysis. Results Serotonin and PYY cell densities were reduced in the colon of IBS patients. PP, entroglucagon, and somatostatin- immunoreactive cells were too few to enable reliable quantification
Epigenetic regulation of prostate cancer
Prostate cancer is a commonly diagnosed cancer in men and a leading cause of cancer deaths. Whilst the underlying mechanisms leading to prostate cancer are still to be determined, it is evident that both genetic and epigenetic changes contribute to the development and progression of this disease. Epigenetic changes involving DNA hypo- and hypermethylation, altered histone modifications and more recently changes in microRNA expression have been detected at a range of genes associated with prostate cancer. Furthermore, there is evidence that particular epigenetic changes are associated with different stages of the disease. Whilst early detection can lead to effective treatment, and androgen deprivation therapy has a high response rate, many tumours develop towards hormone-refractory prostate cancer, for which there is no successful treatment. Reliable markers for early detection and more effective treatment strategies are, therefore, needed. Consequently, there is a considerable interest in the potential of epigenetic changes as markers or targets for therapy in prostate cancer. Epigenetic modifiers that demethylate DNA and inhibit histone deacetylases have recently been explored to reactivate silenced gene expression in cancer. However, further understanding of the mechanisms and the effects of chromatin modulation in prostate cancer are required. In this review, we examine the current literature on epigenetic changes associated with prostate cancer and discuss the potential use of epigenetic modifiers for treatment of this disease
Bilateral signet-ring cell carcinoma of the breast: scintigraphic findings.
Signet-ring cell carcinoma of the breast, first recognized in 1976, behaves aggressively and is associated with a poor prognosis. The tumor is a rare type of breast cancer and often metastasizes to the gastrointestinal tract and female genital tract. The authors report a case of a 48-year-old woman with bilateral signet-ring cell carcinoma of the breasts with multiple skeletal metastases and gastric metastasis. The breast cancer was depicted on a Tc-99m MIBI scintimammogram
Navigation stability: A new isolation level in ORDBMSs
In order to enhance the performance, many database management systems (DBMSs) execute transactions at isolation level 2 rather than at isolation level 3, the strict two phase locking, even if it sacrifices consistency to a certain degree. Cursor stability, a variant of isolation level 2 in relational DBMs (RDBMSs), has been widely used as a useful technique for obtaining concurrency achievable at level 2 without much sacrificing consistency. However, cursor stability is much less usable in object-relational DBMSs (ORDBMSs) because navigational applications in ORDBMSs can suffer from critical inconsistency problems such as dangling pointers, lost updates, and reading inconsistent complex objects. In this paper, we propose a new isolation level, navigation stability, that prevents the inconsistency problems of cursor stability for navigational applications, while avoiding significant degradation of the concurrency of level 3. First, we analyze the inconsistency problems of cursor stability for navigational applications. Second, we define navigation stability as an extension of cursor stability and show that it solves those inconsistency problems of cursor stability in ORDBMSs. Third, through extensive simulation, we show that navigation stability significantly enhances the performance compared with level 3. For workloads consisting of transactions of long duration, compared with level 3, the throughput of navigation stability is enhanced by up to 200%; the average response time reduced by as much as 55%; and the abort ratio reduced by as much as 77%. From these results, we conclude that navigation stability is a useful isolation level in ORDBMSs that can be used in place of isolation level 3 to improve the performance and concurrency without significant sacrifice of consistency
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Effects of Lactobacillus acidophilus 43121 and a mixture of Lactobacillus casei and Bifidobacterium longum on the serum cholesterol level and fecal sterol excretion in hypercholesterolemia-induced pigs
595-60
Recommended from our members
Effects of Lactobacillus acidophilus 43121 and a mixture of Lactobacillus casei and Bifidobacterium longum on the serum cholesterol level and fecal sterol excretion in hypercholesterolemia-induced pigs
595-60
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