局部进展期胃癌微创外科进展

胃癌是全球范围内常见的恶性肿瘤之一,中国大部分胃癌患者确诊时已处于局部进展期。目前已证实以腹腔镜手术为代表的微创胃癌根治术具有不亚于传统开腹手术的近、远期疗效,微创外科手术逐渐成为局部进展期胃癌患者的主要手术方式。随着胃癌外科治疗理念不断更新,新技术不断涌现,使胃癌外科朝着微创化、精准化的方向发展。本文结合近年来国内外相关研究,就局部进展期胃癌微创外科进展进行综述。

Effect of visceral obesity on outcomes of fluorescence-guided lymphadenectomy during laparoscopic gastrectomy for gastric cancer:Post hoc analysis of a randomized phase 3 trial

Objective:To explore the impact of visceral fat area(VFA)on the short-and long-term efficacy of indocyanine green(ICG)-guided D2 lymphadenectomy for gastric cancer(GC).Methods:A post hoc analysis was performed in patients who participated in a phase 3 randomized clinical trial of ICG-guided laparoscopic radical gastrectomy vs.conventional laparoscopic radical gastrectomy from November 2018 to July 2019.The VFA was calculated based on preoperative computed tomography images.Short-term efficacy included the quality of lymph node(LN)dissection and surgical outcomes,while long-term efficacy included overall survival(OS)and recurrence-free survival(RFS).Results:This study included 126 patients each in the ICG(high-VFA,n=43)and non-ICG groups(high-VFA,n=38).Compared with the non-ICG group,the ICG group had significantly more retrieved LNs(low-VFA:50.1 vs.43.9,P=0.001;high-VFA:49.6 vs.37.5,P<0.001)and a significantly lower LN noncompliance rate(low-VFA:32.5%vs.50.0%,P=0.020;high-VFA:32.6%vs.73.7%,P<0.001),regardless of the VFA.The ICG group had a shorter postoperative hospital stay and fewer intra-abdominal infections than the ICG group in the high-VFA patients(P=0.025 and P=0.020,respectively)but not in the low-VFA patients.Regardless of the VFA,the 3-year OS(RFS)was better in the ICG group than in the non-ICG group[low-VFA:83.1%(76.9%)vs.73.9%(67.0%);high-VFA:90.7%(90.7%)vs.73.7%(73.5%);P for interaction=0.474(0.547)].Conclusions:The short-and long-term efficacies of ICG tracing were not influenced by visceral obesity.

Accelerating the Screening of Modified MA_(2)Z_(4) Catalysts for Hydrogen Evolution Reaction by Deep Learning-Based Local Geometric Analysis

Machine learning(ML)integrated with density functional theory(DFT)calculations have recently been used to accelerate the design and discovery of single-atom catalysts(SACs)by establishing deep structure–activity relationships.The traditional ML models are always difficult to identify the structural differences among the single-atom systems with different modification methods,leading to the limitation of the potential application range.Aiming to the structural properties of several typical two-dimensional MA_(2)Z_(4)-based single-atom systems(bare MA_(2)Z_(4) and metal single-atom doped/supported MA_(2)Z_(4)),an improved crystal graph convolutional neural network(CGCNN)classification model was employed,instead of the traditional machine learning regression model,to address the challenge of incompatibility in the studied systems.The CGCNN model was optimized using crystal graph representation in which the geometric configuration was divided into active layer,surface layer,and bulk layer(ASB-GCNN).Through ML and DFT calculations,five potential single-atom hydrogen evolution reaction(HER)catalysts were screened from chemical space of 600 MA_(2)Z_(4)-based materials,especially V_(1)/HfSn_(2)N_(4)(S)with high stability and activity(Δ_(GH*)is 0.06 eV).Further projected density of states(pDOS)analysis in combination with the wave function analysis of the SAC-H bond revealed that the SAC-dz^(2)orbital coincided with the H-s orbital around the energy level of−2.50 eV,and orbital analysis confirmed the formation ofσbonds.This study provides an efficient multistep screening design framework of metal single-atom catalyst for HER systems with similar two-dimensional supports but different geometric configurations.

Computational screening of O‐functional MXenes for electrocatalytic ammonia synthesis

The nitrogen reduction reaction(NRR)using new and efficient electrocatalysts is a promising al‐ternative to the traditional Haber‐Bosch process.Nevertheless,it remains a challenge to design efficient catalysts with improved catalytic performance.Herein,various O‐functional MXenes were investigated as NRR catalysts by a combination of density functional theory calculations and least absolute shrinkage and selection operator(LASSO)regression.Nb_(3)C_(2)O_(X) has been regarded as a promising catalyst for the NRR because of its stability,activity,and selectivity.The poten‐tial‐determining step is*NH_(2) hydrogenation to*NH3 with a limiting potential of-0.45 V.Further‐more,via LASSO regression,the descriptors and equations fitting the relationship between the properties of O‐functional MXenes and NRR activity have been proposed.This work not only pro‐vides a rational design strategy for catalysts but also provides machine learning data for further investigation.

Trace water triggers high-efficiency photocatalytic hydrogen peroxide production

Photocatalytic production of hydrogen peroxide(H_(2)O_(2))has attracted much attentions as a promising method for sustainable solar fuel.Here,we demonstrate that trace water can drastically boost highefficiency photocatalytic production of H_(2)O_(2) with a record-high concentration of 113 mmol L^(-1) using alkali-assisted C_(3)N_(4) as photocatalyst in water/alcohol mixture solvents.By electron paramagnetic resonance(EPR)measurement,the radical species generated during the photocatalytic process of H_(2)O_(2) are identified.We propose alcohol is used to provide and stabilize-OOH radicals through hydrogen bond,while trace water could trigger photocatalytic production of H_(2)O_(2) via providing and transferring indispensable free protons to completely consume OOH radicals,which breaks the reaction balance of-OOH radical generation from alcohol.Thus-OOH radicals could be supplied by alcohol continuously to serve as a reservoir for high-efficiency production of H_(2)O_(2).These results pave the way towards photocatalytic method on semiconductor catalysts as an outstanding approach for production of hydrogen peroxide.

Building highly active hybrid double-atom sites in C_(2)N for enhanced electrocatalytic hydrogen peroxide synthesis

Two-electron(2 e^(-))oxygen reduction reaction(ORR)shows great promise for on-site electrochemical synthesis of hydrogen peroxide(H_(2)O_(2)).However,it is still a great challenge to design efficient electrocatalysts for H_(2)O_(2)synthesis.To address this issue,the logical design of the active site by controlling the geometric and electronic structures is urgently desired.Therefore,using density functional theory(DFT)computations,two kinds of hybrid double-atom supported on C_(2)N nanosheet(RuCu@C_(2)N and PdCu@C_(2)N)are screened out and their H_(2)O_(2)performances are predicted.PdCu@C_(2)N exhibits higher activity for H_(2)O_(2)synthesis with a lower overpotential of 0.12 V than RuCu@C_(2)N(0.59 V),Ru_(3)Cu(110)facet(0.60 V),and PdCu(110)facet(0.54 V).In aqueous phase,the adsorbed O_(2)is further stabilized with bulk H_(2)0 and the thermodynamic rate-determining step of 2 e^(-) ORR change.The activation barrier on PdCu@C_(2)N is 0.43 eV lower than the one on RuCu@C_(2)N with 0.68 eV.PdCu@C_(2)N is near the top of 2 e^(-) ORR volcano plot,and exhibits high selectivity of H_(2)O_(2.)This work provides guidelines for designing highly effective hybrid double-atom electrocatalysts(HDACs)for H_(2)O_(2)synthesis.

Geometric and electronic effects on the performance of a bifunctional Ru2P catalyst in the hydrogenation and acceptorless dehydrogenation of N‐heteroarenes

The development of bifunctional catalysts for the efficient hydrogenation and acceptorless dehydrogenation of N‐heterocycles is a challenge.In this study,Ru_(2)P/AC effectively promoted reversible transformations between unsaturated and saturated N‐heterocycles affording yields of 98%and 99%,respectively.Moreover,a remarkable enhancement in the reusability of Ru_(2)P/AC was observed compared with other Ru‐based catalysts.According to density functional theory calculations,the superior performance of Ru_(2)P/AC was ascribed to specific synergistic factors,namely geometric and electronic effects induced by P.P greatly reduced the large Ru‐Ru ensembles and finely modified the electronic structures,leading to a low reaction barrier and high desorption ability of the catalyst,further boosting the hydrogenation and acceptorless dehydrogenation processes.

A first-principles study of reaction mechanism over carbon decorated oxygen-deficient TiO_(2) supported Pd catalyst in direct synthesis of H_(2)O_(2)

The choice of support is one of the most significant components in the direct synthesis of H_(2)O_(2).Aiming to improvement of activity and selectivity of H_(2)O_(2) on Pd/TiO_(2) surface,we systematically investigated the important elementary steps on Pd/TiO_(2)-Vo@C,Pd/TiO_(2)-Vo,Pd/TiO_(2)-2 Vo,Pd/TiO_(2),and Pd/C using the first-principles calculations.The Bader charge analysis and charge density difference of O_(2) adsorption elucidate the relationship between the electronic distribution and chemisorption energy.The effective barrier analysis further enables to quantitatively estimate the reactivity of H_(2)O_(2) and H2O.We demonstrate unambiguously that the selectivity of H2O formation is boosted as the oxygen vacancy concentration raised.Moreover,the introduction of C into a TiO_(2) with appropriate oxygen vacancies can slightly reduce the effective barrier for H_(2)O_(2) formation and increase the effective barrier for H2O formation leading to a higher activity and selectivity of H_(2)O_(2) formation.Our finding suggests that carbon-doped oxygen vacancy TiO_(2) supported Pd is potential alternative catalyst compared with the Pd/TiO_(2).

Synergistic effect of size-dependent PtZn nanoparticles and zinc single-atom sites for electrochemical ozone production in neutral media

Electrochemical ozone production(EOP) via water electrolysis represents an attractive method for the generation of high-purity O3. Herein, the X-PtZn/Zn-N-C electrocatalysts show a strong structural sensitive behavior depends on the size of the PtZn nanoparticles and their EOP activity exhibits a volcano-type dependence for the O3 performance in neutral media. The 7.7-PtZn/Zn-N-C exhibits EOP current efficiency of 4.2%, and shows the prominent performance in the production of gaseous O3 with a value of 1647 ppb at 30 min, which is almost 4-fold compared to 2.2-Pt Zn/Zn-N-C. Based on the experiments and theoretical calculations, the performance of the EOP process was determined by the nanoparticle size-effect and the synergistic effect between the PtZn nanoparticles and atomically dispersed Zn-N-C. Furthermore, the fivemembered cyclic structure of O3 can be stabilized between the PtZn nanoparticle and the Zn-N-C support,indicating that O3 is produced at the interface.

A generalized formula for two-dimensional diffusion of CO in graphene nanoslits with different Pt loadings

Catalytic performance of supported metal catalysts not only depends on the reactivity of metal,but also the adsorption and diffusion properties of gas molecules which are usually affected by many factors,such as temperature,pressure,properties of metal clusters and substrates,etc.To explore the impact of each of these macroscopic factors,we simulated the movement of CO molecules confined in graphene nanoslits with or without supported Pt nanoparticles.The results of molecular dynamics simulations show that the diffusion of gas molecules is accelerated with high temperature,low pressure or low surface-atom number of supported metals.Notably,the supported metal nanoparticles greatly affect the gas diffusion due to the adsorption of gas molecules.Furthermore,to bridge a quantitative relationship between microscopic simulation and macroscopic properties,a generalized formula is derived from the simulation data to calculate the diffusion coefficient.This work helps to advise the diffusion modulation of gas molecules via structural design of catalysts and regulation of reaction conditions.

The Structural and Chemical Reactivity of Lattice Oxygens on β-PbO_(2 ) EOP Electrocatalysts

The oxygen evolution reaction(OER)and electrochemical ozone production(EOP)attracted considerable attention due to their wide applications in electrocatalysis,but the detailed reaction mechanism of product formation as well as the voltage effect on O_(2)/O_(3)formation still remains unclear.In this work,density functional theory calculations were used to systematically investigate the possible reaction mechanisms of OER and EOP on the PbO_(2)(110)surface,with the possible reaction network involving surface lattice oxygen atoms(LOM)proposed.The results show that the LOM-2 reaction pathway involving two surface lattice oxygen atoms(Olatt)and one oxygen atom from H_(2)O was the most thermodynamically reactive.Different potential determining step(PDS)was obtained depending on the multiple reaction pathway,and the results show that the facile diffusion of Olattwould proceed the LOM pathway and promote the formation of surface oxygen vacancies(O_(vac1)/O_(vac2)).Furthermore,O_(vac1)/O_(vac2)formation on the surface would trigger further reactions of H_(2)O adsorption and splitting,which refilled the oxygen vacancy and ensured the considerable stability of the PbO_(2)(110)surface.Multiple H_(2)O dissociation pathways were proposed on PbO_(2)(110)with oxygen vacancy sites:the acid-base interaction mechanism and the vacancy fulfilling mechanism.

Tuning the ratio of Bi/Bi_(2)O_(3)in Bi/PNC nanosheet for highefficiency electrosynthesis hydrogen peroxide

Electrocatalytic two-electron oxygen reduction reaction(2e-ORR)is a promising method for producing green and sustainable H_(2)O_(2)but lacks high selectivity and yields electrocatalysts.And it is critical to develop catalysts that meet industrial demands.Herein,we report the different ratios of Bi0/Bi^(3+)supported on a phosphorus,nitrogen,and carbon nanosheet(Bi/PNC),which can reduce O_(2) to H_(2)O_(2)with high selectivity(up to 97.75%at 0.4 VRHE)in 0.1 M KOH electrolyte and retain 97%selectivity even after 100 h electrolysis.Then a homemade flow-cell system was built for electrocatalytic production of H_(2)O_(2)under an O_(2) atmosphere using an improved gas diffusion electrode.The Bi/PNC-4 can achieve a high H_(2)O_(2)yield of 2.76 mol·gcatalyst^(-1)·h^(-1)(alkaline),5.29 mol·gcatalyst^(-1)·h^(-1)(neutral),and 3.50 mol·gcatalyst^(-1)·h^(-1)(acid)in universal pH conditions.The in-situ generated H_(2)O_(2)can function as a degradation agent for efficiently degrading pesticides and antibiotics.The outstanding selectivity and activities are attributed to the synergistic effects of Bi0 and Bi^(3+)that promote proton-coupled reduction of O_(2) to OOH^(*)(ΔGOOH^(*)=4.27 eV),and the formation of H_(2)O_(2).The fast yield of H_(2)O_(2)on Bi/PNC catalysts in flow-cell provides a promising path of electrocatalytic 2e-ORR for practical H_(2)O_(2)production.