157 research outputs found

    Augmenting intrinsic fenton-like activities of MOF-derived catalysts via N-molecule-assisted self-catalyzed carbonization

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    To overcome the ever-growing organic pollutions in the water system, abundant efforts have been dedicated to fabricating efficient Fenton-like carbon catalysts. However, the rational design of carbon catalysts with high intrinsic activity remains a long-term goal. Herein, we report a new N-molecule-assisted self-catalytic carbonization process in augmenting the intrinsic Fenton-like activity of metal–organic-framework-derived carbon hybrids. During carbonization, the N-molecules provide alkane/ammonia gases and the formed iron nanocrystals act as the in situ catalysts, which result in the elaborated formation of carbon nanotubes (in situ chemical vapor deposition from alkane/iron catalysts) and micro-/meso-porous structures (ammonia gas etching). The obtained catalysts exhibited with abundant Fe/Fe–Nx/pyridinic-N active species, micro-/meso-porous structures, and conductive carbon nanotubes. Consequently, the catalysts exhibit high efficiency toward the degradation of different organic pollutions, such as bisphenol A, methylene blue, and tetracycline. This study not only creates a new pathway for achieving highly active Fenton-like carbon catalysts but also takes a step toward the customized production of advanced carbon hybrids for diverse energy and environmental applications

    Two-dimensional non-Hermitian skin effect in an ultracold Fermi gas

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    The concept of non-Hermiticity has expanded the understanding of band topology leading to the emergence of counter-intuitive phenomena. One example is the non-Hermitian skin effect (NHSE), which involves the concentration of eigenstates at the boundary. However, despite the potential insights that can be gained from high-dimensional non-Hermitian quantum systems in areas like curved space, high-order topological phases, and black holes, the realization of this effect in high dimensions remains unexplored. Here, we create a two-dimensional (2D) non-Hermitian topological band for ultracold fermions in spin-orbit-coupled optical lattices with tunable dissipation, and experimentally examine the spectral topology in the complex eigenenergy plane. We experimentally demonstrate pronounced nonzero spectral winding numbers when the dissipation is added to the system, which establishes the existence of 2D skin effect. We also demonstrate that a pair of exceptional points (EPs) are created in the momentum space, connected by an open-ended bulk Fermi arc, in contrast to closed loops found in Hermitian systems. The associated EPs emerge and shift with increasing dissipation, leading to the formation of the Fermi arc. Our work sets the stage for further investigation into simulating non-Hermitian physics in high dimensions and paves the way for understanding the interplay of quantum statistics with NHSE.Comment: 10 pages, 4 figures with supplementary informatio

    Age-associated microbiome shows the giant panda lives on hemicelluloses, not on cellulose

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    The giant panda feeds almost exclusively on bamboo, a diet highly enriched in lignin and cellulose, but is characterized by a digestive tract similar to carnivores. It is still large unknown if and how the giant panda gut microbiota contributes to lignin and cellulose degradation. Here we show the giant pandas’ gut microbiota does not significantly contribute to cellulose and lignin degradation. We found that no operational taxonomic unit had a nearest neighbor identified as a cellulolytic species or strain with a significant higher abundance in juvenile than cubs, a very low abundance of putative lignin and cellulose genes existed in part of analyzing samples but a significant higher abundance of genes involved in starch and hemicellulose degradation in juveniles than cubs. Moreover, a significant lower abundance of putative cellulolytic genes and a significant higher abundance of putative α-amylase and hemicellulase gene families were present in giant pandas than in omnivores or herbivores

    The safety and efficacy of Houtou Jianweiling tablet in patients with chronic non-atrophic gastritis: a double-blind, non-inferiority, randomized controlled trial

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    Background: Common symptoms of Chronic Non-atrophic Gastritis (CNAG) include nausea, stomach distension, and abdominal pain. The Houtou Jianweiling Tablet (HTJWT) is a chinese patent medicine (CN1368229A) and it has been used clinically for more than 20 years with proven clinical efficacy in treating CNAG, prompted us to establish the clinical efficacy and safety of HTJWT on patients with mild to moderate CNAG symptoms in Pakistani population.Methods: This phase II, double-blind, randomized, parallel-controlled trial was conducted in a single center between November 2022 and February 2023 in Pakistan. In a ratio of 1:1, total 240 CNAG patients with erosion identified by pathological biopsy and gastroscopy were randomly assigned to control (Omeprazole) group (n = 120) and the treatment (HTJWT) group (n = 120). Patients in the treatment group received orally four HTJWT (0.38g/tablet), three times a day and one placebo of Omeprazole enteric-coated tablet prior to breakfast, daily. On the other hand, patients in the control group received one Omeprazole enteric-coated tablet (20 mg/tablet) prior to breakfast and four placebo of HTJWT, thrice a day. The patients consumed the investigated drugs (i.e., treatment and control) treatment regimen was followed for a duration of 28 days. The safety of the patients were evaluated through adverse events, serious adverse events and laboratory tests such as blood biochemistry, urine analysis, liver and renal function tests. Vital signs like; blood pressure, pulse rate, body temperature, respiratory rate for all the patients were recorded. The cardiac status of the patients were assessed through electrocardiogram (ECG). The primary efficacy indicators were the improvement rate of gastric distention and gastralgia as the main clinical symptoms. Secondary indicators were visual analogue score (VAS); improvement rate of secondary clinical symptoms and signs; improvement rate of total clinical signs and symptoms; the disappearance/remission rate of Gastric pain and, remission/disappearance time of gastric distension; and the negative conversion rate of Helicobacter pylori (H. pylori). The outcomes among each group were compared using the chi-square test.Results: Patients in both groups had good drug compliance (80%–120%), and there was no statistically significant difference in the patients’ baseline characteristics. The clinical improvement rate was found to be 91.1% in the treatment group and 91.0% in the control group with negligible variation among the two groups (p = 0.9824; 95% confidence interval: -0.0781–0.0798). Similarly, hardly no difference was found in the negative conversion rate of H. pylori between the treatment group and the control group (i.e., 70.1% and 71.8% respectively, p = 0.8125). There were no significant differences in respiratory rate, vital signs, blood pressure, laboratory results for blood biochemistry, urine analysis, liver and renal function tests between the two groups. The ECG assessment carried out for the treatment and control group revealed no considerable difference. Margin variation in the disappearance time of gastric pain (p = 0.1860) and remission rate (p = 0.5784) between the two groups were observed. The control group exhibited a faster remission period for gastrointestinal discomfort indications as compared to treatment group (p = 0.0430). Only one patient in the control group experienced mild to moderate adverse events, namely,; epigastric pain and dyspepsia. The results were consistent with the intention-to-treat and per-protocol analysis that included patients who were 100% compliant to the assigned therapy.Conclusion: The lower limit of confidence interval (CI, 95%) for the differences in the effective rate between the treatment and the control groups was found to be −0.0781 which is greater than −0.15, hence the treatment group is non-inferior to the control group. The therapeutic dosage used in the trial and treatment period did not cause any significant adverse event, and there were no obvious changes in the ECG profile, vital signs and biochemistry of the patients. Based on the clinical efficacy evaluation and reported adverse events, it can be concluded that the HTJWT is a safe and effective traditional chinese medicine for the treatment of patients suffering from chronic non-atrophic gastritis with mild to moderate symptoms.Clinical Trial Registration: [www.clinicaltrials.gov], identifier [NCT04672018]
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