Comparisons of short-term and long-term results between laparoscopic between open pancreaticoduodenectomy for pancreatic tumors: A systematic review and meta-analysis

Objective: The efficacy of pancreaticoduodenectomy and open pancreaticoduodenectomy for pancreatic tumors is controversial. The study aims to compare the efficacy of laparoscopic pancreaticoduodenectomy (LPD) and open pancreaticoduodenectomy (OPD) in the treatment of pancreatic tumors through systematic evaluation and meta-analysis.Methods: PubMed, Embase, Cochrane Library and Web of science databases were searched for clinical studies on the treatment of pancreatic tumors with LPD and OPD. The end time for the searches was 20 July 2022. Rigorous inclusion and exclusion criteria were used to screen the articles, the Cochrane manual was used to evaluate the quality of the included articles, and the stata15.0 software was used for statistical analysis of the indicators.Results: In total, 16 articles were included, including two randomized controlled trials and 14 retrospective studies. Involving a total of 4416 patients, 1275 patients were included in the LPD group and 3141 patients in the OPD group. The results of the meta-analysis showed that: the operation time of LPD was longer than that of OPD [WMD = 56.14,95% CI (38.39,73.89), p = 0.001]; the amount of intraoperative blood loss of LPD was less than that of OPD [WMD = −120.82,95% CI (−169.33, −72.30), p = 0.001]. No significant difference was observed between LPD and OPD regarding hospitalization time [WMD = −0.5,95% CI (−1.35, 0.35), p = 0.250]. No significant difference was observed regarding postoperative complications [RR = 0.96,95% CI (0.86,1.07, p = 0.463]. And there was no significant difference regarding 1-year OS and 3-year OS: 1-year OS [RR = 1.02,95% CI (0.97,1.08), p = 0.417], 3-year OS [RR = 1.10 95% CI (0.75, 1.62), p = 0.614%].Conclusion: In comparison with OPD, LPD leads to less blood loss but longer operation time, therefore the bleeding rate per unit time of LPD is less than that of OPD. LPD has obvious advantages. With the increase of clinical application of LPD, the usage of LPD in patients with pancreatic cancer has very good prospect. Due to the limitations of this paper, in future studies, more attention should be paid to high-quality, multi-center, randomized controlled studies

Effect of enrichment of plate-type fuel assembly on fuel performance

BackgroundThe enrichment of nuclear fuel may significantly influence the fuel performance of a reactor.PurposeThis study aims to explore the effect of U3Si2-Al plate-type fuel enrichment on its performance,MethodsThe fuel performance analysis code BEEs-Plates, neutronics Monte Carlo code OpenMC, and the one-dimensional system analysis code ZEBRA were coupled together within the MOOSE (Multiphysics Object-Oriented Simulation Environment) framework. Then the coupling code was employed to conduct the multiphysics coupling calculation for JRR-3 (Japanese Research Reactor No.3) fuel assembly enriched at 15%, 20%, and 25%. The data exchange among the three codes were realized with the help of interpolation transfer method implemented in MOOSE. Additionally, neutron physical parameters and fuel performance parameters after 231 d of operation were analyzed when the average fuel consumption of the module was 125.71 GWd∙tU-1.ResultsThe calculation results indicate that the max power density of fuel assembly enriched at 25% is 18% higher than the assembly enriched at 15%. Due to the high thermal conductivity of aluminum, the temperature difference in the fuel assembly is almost negligible whilst there is a significant difference in the fast neutron fluence. The results of fuel temperature and fast neutron fluence show that the volumetric strain is more obviously affected by the fuel temperature. Specifically, the plastic strain of the assembly with 25% enrichment is approximately 40% higher than that of the assembly with 15% enrichment.ConclusionThe analysis results of this study suggest that the assembly with a higher enrichment is more prone to failure

Enantioselective Organocatalyzed Direct α‑Thiocyanation of Cyclic β‑Ketoesters by <i>N</i>‑Thiocyanato­phthalimide

A new electrophilic thiocyanation reagent, <i>N</i>-thiocyanatophthalimide, was synthesized and applied to the first example of catalytic asymmetric electrophilic α-thiocyanation of various cyclic β-ketoesters by the bifunctional cinchona alkaloid catalysis. Thus, a variety of chiral α-thiocyanato β-ketoesters with a quaternary carbon center have been achieved in excellent yields (up to 99%) and high enantioselectivities (up to 94% <i>ee</i>) in a convenient manner

<i>N</i>‑Thiocyanatosaccharin: A “Sweet” Electrophilic Thiocyanation Reagent and the Synthetic Applications

<i>N</i>-Thiocyanatosaccharin (<b>R</b>_<b>1</b>) was readily prepared from the sweet additive Saccharin in two steps with a 71% overall yield. By applying this new reagent to diverse nucleophiles such as benzothiophenes, indoles, oxindoles, aromatic amines, phenols, β-keto carbonyl compounds, and aromatic ketones, a novel electrophilic thiocyanation reaction was achieved with high yields (up to 99%). The potential recycling of Saccharin, the wide scope of substrates, and the mild reaction conditions made this protocol much more practical

Keys Unlocking Redispersion of Reactive PdO_<i>x</i> Nanoclusters on Ce-Functionalized Perovskite Oxides for Methane Activation.

Nowadays, trace CH4 emitted from vehicle exhausts severely threaten the balance of the ecology system of our earth. Thereby, the development of active and stable catalysts capable of methane conversion under mild conditions is critical. Here, we present a convenient method to redisperse catalytically inert PdO nanoparticles (NPs) (>10 nm) into reactive PdOx nanoclusters (∼2 nm) anchored on a Ce-doped LaFeO3 parent. Isothermally activated in an N2 flow, the redispersed catalyst achieved a CH4 conversion of 90% at 400 °C, which is significantly higher than the fresh and H2- and O2-treated counterparts (625, 616, and 641 °C, respectively), indicating the importance of the gas atmosphere in the redispersion of PdO NPs. In addition, the comprehensive catalyst characterizations demonstrated that the isolated Ce ions in the perovskite lattice play an irreplaceable role in the redispersion of reactive sites and the reduction of the energy barrier for C-H scission. More importantly, the Ce additive helps to stabilize the PdOx species by reducing overoxidation, resulting in significant lifetime extension. Through a thorough understanding of structural manipulation, this study sheds light on the design of highly performing supported catalysts for methane oxidation

Understanding climate change impacts on drought in China over the 21st century: a multi-model assessment from CMIP6

Abstract The future state of drought in China under climate change remains uncertain. This study investigates drought events, focusing on the region of China, using simulations from five global climate models (GCMs) under three Shared Socioeconomic Pathways (SSP1-2.6, SSP3-7.0, and SSP5-8.5) participating in the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP3b). The daily Standardized Precipitation Evapotranspiration Index (SPEI) is employed to analyze drought severity, duration, and frequency over three future periods. Evaluation of the GCMs’ simulations against observational data indicates their effectiveness in capturing historical climatic change across China. The rapid increase in CO2 concentration under high-emission scenarios in the mid- and late-future century (2040–2070 and 2071–2100) substantially influences vegetation behavior via regulation on leaf stomata and canopy structure. This regulation decelerates the increase in potential evapotranspiration, thereby mitigating the sharp rise in future drought occurrences in China. These findings offer valuable insights for policymakers and stakeholders to develop strategies and measures for mitigating and adapting to future drought conditions in China

Catalytic Asymmetric Electrophilic Cyanation of 3‑Substituted Oxindoles

The first example of catalytic asymmetric electrophilic cyanation of 3-substituted oxindoles has been achieved using readily accessible 4-acetylphenyl cyanate as the cyano source. Thus, a series of all-carbon quaternary center 3-aryl-3-cyano oxindoles were prepared using a zinc complex of a chiral pincer ligand as the catalyst in high yields (up to 95%) and excellent enantioselectivities (up to >99% ee) in the presence of 4 Å MS and 2,6-lutidine in THF at 0 °C