Quantum Dynamics Calculations on Isotope Effects of Hydrogen Transfer Isomerization in Formic Acid Dimer

We present a quantum dynamics study on the isotope effects of hydro-gen transfer isomerization in the formic acid dimer,and this is achieved by multidimensional dy-namics calculations with an efficient quantum mechanical theoretical scheme developed by our group,on a full-dimensional neural network ab initio potential energy surface.The ground-state and fundamental tun-neling splittings for four deuterium isotopologues of formic acid dimer are considered,and the calculated results are in very good general agreement with the avail-able experimental measurements.Strong isotope effects are revealed,the mode-specific funda-mental excitation effects on the tunneling rate are evidently influenced by the deuterium sub-stitution of H atom with the substitution on the OH bond being more effective than on the CH bond.Our studies are helpful for acquiring a better understanding of isotope effects in the double-hydrogen transfer processes.

Ring Polymer Molecular Dynamics of the C(^(1)D)+H_(2) Reaction on the Most Recent Potential Energy Surfaces

Ring polymer molecular dynamics(RPMD)calculations for the C(^(1)D)+H_(2)reaction are performed on the Zhang-Ma-Bian ab initio potential energy surfaces(PESs)recently constructed by our group,which are unique in very good descriptions of the regions around conical intersections and of van der Waals(vdW)interactions.The calculated reaction thermal rate coefficients are in very good agreement with the latest experimental results.The rate coefficients obtained from the ground˜a^(1)A′ZMB-a PES are much larger than those from the previous RKHS PES,which can be attributed to that the vdW saddles on our PESs have very different dynamical effects from the vdW wells on the previous PESs,indicating that the RPMD approach is able to include dynamical effects of the topological structures caused by vdW interactions.The importance of the excited˜b^(1)A′′ZMB-b PES and quantum effects in the title reaction is also underscored.

Accurate Quantum Dynamics of the Simplest Isomerization System Involving Double-H Transfer

We perform accurate quantum dynamcs calculations on the isomerization of vinylidene-acetylene.Large-scale parallel computations are accomplished by an efficient theoretical scheme developed by our group,in which the basis functions are customized for the double-H transfer process.The A_(1)' and B_(2)'' vinylidene and delocalization states are obtained.The peaks recently observed in the cryo-SEVI spectra are analyzed,and very good agreement for the energy levels is achieved between theory and experiment.The discrepancies of energy levels between our calculations and recent experimental cryo-SEVI spectra are of similar magnitudes to the experimental error bars,or≤30 cm^(-1) excluding those involving the excitation of the CCH_(2) scissor mode.A kind of special state,called the isomerization state,is revealed and reported,which is characterized by large probability densities in both vinylidene and acetylene regions.In addition,several states dominated by vinylidene character are reported for the first time.The present work would contribute to the understanding of the double-H transfer.

Optimizing prostate biopsy for repeat transrectal prostate biopsies patients

Objective： Diagnosis of patients with negative prostate biopsy and persistent suspicion of prostate cancer re- mains a serious problem. In this study, we investigated the application of optimizing prostate biopsy for patients who need repeat prostate biopsy. Methods： In this prospective, non-randomized phase-I clinical trial, the prostate cancer detection rate of initial detection scheme was compared with optimizing prostate biopsy scheme. The number of punctures of initial detection scheme was the same as that of optimizing prostate biopsy scheme. The puncture direction of optimizing prostate biopsy was a 45~ angle to the sagittal plane from front, middle, and back. The two cores from each lateral lobe were horizontally inwardly inclined 45~. Results： A total of 45 patients with initial negative biopsy for cancer were received the optimizing prostate biopsy scheme. The cancer detection rate was 17.8% （8/45）, and prostate intraepithelial neoplasm （PIN） was 6.7% （3/45）. The pa- tients receiving repeat transrectal prostate biopsies were pathologically diagnosed as lower Gleason grade prostate cancers. Conclusion： The cancer detection rate of repeat biopsy prostate cancer is lower than that of initial biopsy. Our study showed that the optimizing prostate biopsy is important to improve the detection rate of repeat transrecta~ prostate biopsies patients.

The efficacy and safety of ureteroscopic lithotripsy and flexible ureteroscopy with continuous anticoagulant or antiplatelet drugs:A multicenter retrospective real-world study

Objective The objective of this study is to assess the effectiveness and safety of ureteroscopic lithotripsy and flexible ureteroscopy(fURS)for treating patients on anticoagulant(AC)or antiplatelet(AP)medications.Patients and Methods The study included 213 patients with urinary stones who underwent ureteroscopic lithotripsy or fURS between January 2019 and October 2022 at the Shanghai Municipal Hospital Urology Specialist Alliance.Among these patients,15 received AC therapy,193 received AP therapy,and 5 received both AC and AP therapy.Patients were divided into 3 groups based on the real-world management of antithrombotic drugs:the continuation group(n=62),the discontinuation group(n=91),and the discontinuation and bridge heparin group(n=60).Intraoperative and postoperative outcomes were compared among the 3 groups.Results Age,sex,body mass index,stone location,stone size,stone side,and residual fragments were not different among the groups.None of the patients received blood transfusions or had thromboembolic events,emergencies for gross hematuria,significant bleeding-related complications,or unplanned secondary ureteroscopic surgery.The mean duration of hospital stay of the continuation group(3.97 days)was significantly lower than that of the discontinuation group(5.99 days)and the discontinuation and bridge heparin group(5.75 days)(p<0.001).Conclusions Ureteroscopic lithotripsy and fURS can be performed safely and effectively in patients on AC or AP drugs,resulting in reduced duration of hospital stay.

Synergetic effect of secondary nucleation and growth on the lithium carbonate particle size in the gas-liquid reactive crystallization of LiCl-NH3·H2O-CO2

In this study,the gas-liquid reactive crystallization of LiCl-NH3·H2O-CO2 was adopted to produce Li2CO3.The weakly alkaline nature of NH3·H2O in the absence of any recarbonation process resulted in a unimodal and easily controllable particle size distribution(PSD)of the obtained Li2CO3.The reaction temperature significantly influenced both the Li2CO3 particle size and PSD.By increasing the temperature from 25 to 60℃,the volume weighted mean particle size increased from 50.5 to 100.5μm,respectively.The Li2CO3 secondary nucleation rate and growth rate were obtained by focused beam reflectance measurements and a laser particle size analyzer,respectively.The secondary nucleation rate of Li2CO3 reduced as a function of temperature,whereas the growth rate increased.In addition to improving the surface energy of the crystals to enhance the growth process,higher temperatures also reduced the supersolubility of Li2CO3,which also plays a role to decrease the secondary nucleation rate.At a constant temperature,supersaturation affects the Li2CO3 particle size through the synergistic effect of secondary nucleation and growth.Hence,with improved supersaturation,the mean particle size of Li2CO3 decreased.The results provide a meaningful way to evaluate the crystallization process and to regulate the particle size.

Effects of sulfur on variations in the chemical speciation of heavy metals from fly ash glass

This work designed a new CaO-Al_(2)O_(3)-SiO_(2)-SO3 glass for the immobilization of multiple heavy metals found in dechlorinated fly ash having high amounts of calcium and sulfur. Increasing the (CaO + SO3)/SiO_(2) mass ratio (M(CS/S)) from 0.28 to 0.85 was found to lower the proportions of Mn, Ni and Zn in an unstable state, while an M(CS/S) ratio of 0.51 gave the lowest proportions of unstable Cr and Pb. Decreasing the degree of polymerization of the glassy network increased the proportions of Mn, Cr, Ni, Pb and Zn in the carbonate bound state. The leaching out of metals in this state was the primary cause of degradation of Q^(3) structural units in the glassy network. The amount of Mn in the iron-manganese oxide bound state was increased by increasing the number of Q^(2) units in the silicate network. Decreasing the CaO/SiO_(2) mass ratio (M(C/S)) raised the proportions of Mn, Ni and Zn in the unstable state. An M(C/S) value of 0.43 lowered the proportions of unstable Cr and Pb. A principal components analysis determined that the leaching of toxic heavy metals from the glass was primarily related to the proportions of these metals in the unstable state while there were no evident correlations between leaching and the proportions in stable states.

Nanoformulations targeting immune cells for cancer therapy: mRNA therapeutics

The approved worldwide use of two messenger RNA(mRNA)vaccines(BNT162b2 and mRNA-1273)in late 2020 has proven the remarkable success of mRNA therapeutics together with lipid nanoformulation technology in protecting people against coronaviruses during COVID-19 pandemic.This unprecedented and exciting dual strategy with nanoformulations and mRNA therapeutics in play is believed to be a promising paradigm in targeted cancer immunotherapy in future.Recent advances in nanoformulation technologies play a prominent role in adapting mRNA platform in cancer treatment.In this review,we introduce the biologic principles and advancements of mRNA technology,and chemistry fundamentals of intriguing mRNA delivery nanoformulations.We discuss the latest promising nano-mRNA therapeutics for enhanced cancer immunotherapy by modulation of targeted specific subtypes of immune cells,such as dendritic cells(DCs)at peripheral lymphoid organs for initiating mRNA cancer vaccine-mediated antigen specific immunotherapy,and DCs,natural killer(NK)cells,cytotoxic T cells,or multiple immunosuppressive immune cells at tumor microenvironment(TME)for reversing immune evasion.We highlight the clinical progress of advanced nano-mRNA therapeutics in targeted cancer therapy and provide our perspectives on future directions of this transformative integrated technology toward clinical implementation.