Interaction of hispidin with pepsin:Multi-spectroscopic analyses and docking simulation

Hispidin is a pyranone compound found in edible and medicinal mushrooms of the Phellinus and Inonotus genera.This investigation used fluorescence spectroscopy,UV absorption spectroscopy,and molecular docking to examine the interaction of hispidin with pepsin.The Stern-Volmer method was used to perform the fluorescence quenching measurements at different temperatures(298 K,303 K,and 310 K).According to the findings,hispidin induced a static quenching mechanism in pepsin that resulted in the creation of a hispidin-pepsin complex with binding constants(Ka)ranging from 9.56×10^(4) to 3.45×10^(5) L mol^(-1).The positive values ofΔH(84.6 kJ mol-1)andΔS(337.9 J mol^(-1) K^(-1))demonstrated that hydrophobic forces contributed to forming the hispidin-pepsin complex.The findings of UV-vis absorption,synchronous fluorescence,and 3D fluorescence spectraspectra demonstrated that hispidin altered the conformation and microenvironment of pepsin.According to the analysis of molecular docking,hispidin got into the pepsin's active cavity.The research clarifies the molecular mechanisms by which hispidin binds to pepsin and helps understand its possible biological activity in vivo.

Machine learning predicts portal vein thrombosis after splenectomy in patients with portal hypertension: Comparative analysis of three practical models

BACKGROUND For patients with portal hypertension(PH),portal vein thrombosis(PVT)is a fatal complication after splenectomy.Postoperative platelet elevation is considered the foremost reason for PVT.However,the value of postoperative platelet elevation rate(PPER)in predicting PVT has never been studied.AIM To investigate the predictive value of PPER for PVT and establish PPER-based prediction models to early identify individuals at high risk of PVT after splenectomy.METHODS We retrospectively reviewed 483 patients with PH related to hepatitis B virus who underwent splenectomy between July 2011 and September 2018,and they were randomized into either a training(n=338)or a validation(n=145)cohort.The generalized linear(GL)method,least absolute shrinkage and selection operator(LASSO),and random forest(RF)were used to construct models.The receiver operating characteristic curves(ROC),calibration curve,decision curve analysis(DCA),and clinical impact curve(CIC)were used to evaluate the robustness and clinical practicability of the GL model(GLM),LASSO model(LSM),and RF model(RFM).RESULTS Multivariate analysis exhibited that the first and third days for PPER(PPER1,PPER3)were strongly associated with PVT[odds ratio(OR):1.78,95%confidence interval(CI):1.24-2.62,P=0.002;OR:1.43,95%CI:1.16-1.77,P<0.001,respectively].The areas under the ROC curves of the GLM,LSM,and RFM in the training cohort were 0.83(95%CI:0.79-0.88),0.84(95%CI:0.79-0.88),and 0.84(95%CI:0.79-0.88),respectively;and were 0.77(95%CI:0.69-0.85),0.83(95%CI:0.76-0.90),and 0.78(95%CI:0.70-0.85)in the validation cohort,respectively.The calibration curves showed satisfactory agreement between prediction by models and actual observation.DCA and CIC indicated that all models conferred high clinical net benefits.CONCLUSION PPER1 and PPER3 are effective indicators for postoperative prediction of PVT.We have successfully developed PPER-based practical models to accurately predict PVT,which would conveniently help clinicians rapidly differentiate individuals at high risk of PVT,and thus guide the adoption of timely interventions.

Emulsion Binders with Multiple Crosslinked Structures for High-Performance Lithium-Sulfur Batteries

Lithium-sulfur batteries suffer a lot from the huge volume change and the shuttle effect. However, conventional poly(vinylidene fluoride) binder has intrinsic drawbacks, such as low ion conductivity, weak polysulfide-trapping ability, poor mechanical properties, and requirement of organic solvents. Herein, we designed a functional emulsion binder with multi crosslinked structure. Such a structure was formed by the covalent crosslinking within and between the emulsion particles, which facilitates the adapting of the volume expansion of sulfur cathode, thereby ensuring the integrity of electrodes. Besides, the polar functional groups endow the binder with strong chemisorption of lithium polysulfide and fast lithium-ion migration ability. Thus, the assembled lithium-sulfur battery displayed a high initial discharge capacity of 1246 mAh·g^(−1) at 0.1 C, and a capacity fading rate of 0.04% per cycle after 500 cycles at 0.5 C. Even at a high sulfur mass loading of 4.8 mg·cm^(−2), a high capacity of 956 mAh·g^(−1) was still obtained at 0.2 C.

Recovery and regeneration of Al_2O_3 with a high specific surface area from spent hydrodesulfurization catalyst CoMo/Al_2O_3

Aluminum recovery is a key issue for the overall recycling of valuable metals from spent catalysts. This paper focuses on the recovery and regeneration of alumina with high additional value from the spent hydrodesulfurization catalyst CoMo/Al_2O_3. The results indicate that 98.13% alumina is successfully leached from the treated spent catalysts by an alkaline leaching process under the conditions of 5 mol·L^(-1) sodium hydroxide,a liquid/solid ratio of 20 ml·g^(-1),a temperature of 160 0 C and a reaction time of 4 h. In the leaching residue, no difficult leaching compound is found and cobalt and nickel are enriched,both of which are conducive to the subsequent metal recovery step. The reaction order of aluminum leaching is 0.99. This reaction fits well with the interfacial chemical reaction model, and its apparent activation energy is calculated as 45.50 kJ mol^(-1). Subsequently, y-Al_2O_3 with a high specific surface area of 278.3 m^2·g^(-1), a mean size of 2.2 μm and an average pore size of 3.10 nm is then regenerated from the lixivium, indicating its suitability for use as a catalyst carrier. The recovery and regeneration of alumina from spent catalysts can not only significantly contribute to the total recycling of such hazardous spent catalysts but also provide a new approach for the preparation of y-Al_2O_3 with a high specific surface area using spent catalysts as the aluminum sources.

Phylogenetic analyses of some genera in Oedipodidae （Orthoptera： Acridoidea） based on 16S mitochondrial partial gene sequences

Basedonthe 16S mitochondrial partial gene sequences of 29 genera, containing 26 from Oedipodidae and one each from Tanaoceridae, Pyrgomorphidae and Tetrigidae （as outgroups）, the homologus sequences were compared and phylogenetic analyses were performed. A phylogenetic tree was inferred by neighbor-joining （N J）. The results of sequences compared show that： （i） in a total of 574 bp of Oedipodidae, the number of substituted nucleotides was 265 bp and the average percentages ofT, C, A and G were 38.3%, 11.4%, 31.8% and 18.5%, respectively, and the content of A＋T （70.1%） was distinctly richer than that of C＋G （29.9%）; and （ii） the average nucleotide divergence of 16S rDNA sequences among genera of Oedipodidae were 9.0%, among families of Acridoidea were 17.0%, and between superfamilies （Tetrigoidea and Acridoidea） were 23.9%, respectively. The phylogenetic tree indicated： （i） the Oedipodidae was a monophyletic group, which suggested that the taxonomic status of this family was confirmed; （ii） the genus Heteropternis separated from the other Oedipodids first and had another unique sound-producing structure in morphology, which is the type-genus of subfamily Heteropterninae; and （iii） the relative intergeneric relationship within the same continent was closer than that of different continents, and between the Eurasian genera and the African genera, was closer than that between Eurasians and Americans.