BACKGROUND Gastric cancer(GC)is prevalent and aggressive,especially when patients have distant lung metastases,which often places patients into advanced stages.By identifying prognostic variables for lung metastasis i...BACKGROUND Gastric cancer(GC)is prevalent and aggressive,especially when patients have distant lung metastases,which often places patients into advanced stages.By identifying prognostic variables for lung metastasis in GC patients,it may be po-ssible to construct a good prediction model for both overall survival(OS)and the cumulative incidence prediction(CIP)plot of the tumour.AIM To investigate the predictors of GC with lung metastasis(GCLM)to produce nomograms for OS and generate CIP by using cancer-specific survival(CSS)data.METHODS Data from January 2000 to December 2020 involving 1652 patients with GCLM were obtained from the Surveillance,epidemiology,and end results program database.The major observational endpoint was OS;hence,patients were se-parated into training and validation groups.Correlation analysis determined va-rious connections.Univariate and multivariate Cox analyses validated the independent predictive factors.Nomogram distinction and calibration were performed with the time-dependent area under the curve(AUC)and calibration curves.To evaluate the accuracy and clinical usefulness of the nomograms,decision curve analysis(DCA)was performed.The clinical utility of the novel prognostic model was compared to that of the 7th edition of the American Joint Committee on Cancer(AJCC)staging system by utilizing Net Reclassification Improvement(NRI)and Integrated Discrimination Improvement(IDI).Finally,the OS prognostic model and Cox-AJCC risk stratification model modified for the AJCC system were compared.RESULTS For the purpose of creating the OS nomogram,a CIP plot based on CSS was generated.Cox multivariate regression analysis identified eleven significant prognostic factors(P<0.05)related to liver metastasis,bone metastasis,primary site,surgery,regional surgery,treatment sequence,chemotherapy,radiotherapy,positive lymph node count,N staging,and time from diagnosis to treatment.It was clear from the DCA(net benefit>0),time-de-pendent ROC curve(training/validation set AUC>0.7),and calibration curve(reliability slope closer to 45 degrees)results that the OS nomogram demonstrated a high level of predictive efficiency.The OS prediction model(New Model AUC=0.83)also performed much better than the old Cox-AJCC model(AUC difference between the new model and the old model greater than 0)in terms of risk stratification(P<0.0001)and verification using the IDI and NRI.CONCLUSION The OS nomogram for GCLM successfully predicts 1-and 3-year OS.Moreover,this approach can help to ap-propriately classify patients into high-risk and low-risk groups,thereby guiding treatment.展开更多
Two-dimensional(2D)magnetic materials have attracted tremendous research interest because of the promising application in the next-generation microelectronic devices.Here,by the first-principles calculations,we propos...Two-dimensional(2D)magnetic materials have attracted tremendous research interest because of the promising application in the next-generation microelectronic devices.Here,by the first-principles calculations,we propose a twodimensional ferromagnetic material with high Curie temperature,manganese tetranitride MnN4monolayer,which is a square-planar lattice made up of only one layer of atoms.The structure is demonstrated to be stable by the phonon spectra and the molecular dynamic simulations,and the stability is ascribed to theπ–d conjugation betweenπorbital of N=N bond and d orbital of Mn.More interestingly,the MnN_(4)monolayer displays robust 2D ferromagnetism,which originates from the strong exchange couplings between Mn atoms due to theπ–d conjugation.The high critical temperature of 247 K is determined by solving the Heisenberg model using the Monte Carlo method.展开更多
Great advancement has been made on natural gas hydrates exploration and test production in the northern South China Sea.However,there remains a lot of key questions yet to be resolved,particularly about the mechanisms...Great advancement has been made on natural gas hydrates exploration and test production in the northern South China Sea.However,there remains a lot of key questions yet to be resolved,particularly about the mechanisms and the controls of gas hydrates enrichment.Numerical simulaution would play signficant role in addressing these questions.This study focused on the gas hydrate exploration in the Shenhu Area,Northern South China Sea.Based on the newly obtained borehole and multichannel reflection seismic data,the authors conducted an integrated 3D basin modeling study on gas hydrate.The results indicate that the Shenhu Area has favorable conditions for gas hydrate accumulation,such as temperature,pressure,hydrocarbon source,and tectonic setting.Gas hydrates are most concentrated in the Late Miocene strata,particularly in the structual highs between the Baiyun Sag and the Liwan Sag,and area to the south of it.It also proved the existence of overpressure in the main sag of source rocks,which was subject to compaction disequilibrium and hydrocarbon generation.It also shown that the regional fault activity is not conducive to gas hydrate accumulation due to excess gas seepage.The authors conjecture that fault activity may slightly weaken overpressure for the positive effect of hydrocarbon expulsion and areas lacking regional fault activity have better potential.展开更多
Using the tensor renormalization group method based on the higher-order singular value decomposition, we have studied the phase transitions of the five-state clock model on the square lattice. The temperature dependen...Using the tensor renormalization group method based on the higher-order singular value decomposition, we have studied the phase transitions of the five-state clock model on the square lattice. The temperature dependence of the specific heat indicates the system has two phase transitions, as verified clearly by the correlation function at three representative tem- peratures. By calculating the magnetic susceptibility, we obtained only the upper critical temperature as To2 = 0.9565（7）. Investigating the fixed-point tensor, we precisely locate the transition temperatures at Tcl = 0.9029（1） and Tc2 = 0.9520（1）, consistent well with the Monte Carlo and the density matrix renormalization group results.展开更多
We propose a generalized Lanczos method to generate the many-body basis states of quantum lattice models using tensor-network states （TNS）. The ground-state wave function is represented as a linear superposition com...We propose a generalized Lanczos method to generate the many-body basis states of quantum lattice models using tensor-network states （TNS）. The ground-state wave function is represented as a linear superposition composed from a set of TNS generated by Lanczos iteration. This method improves significantly the accuracy of the tensor-network algorithm and provides an effective way to enlarge the maximal bond dimension of TNS. The ground state such obtained contains significantly more entanglement than each individual TNS, reproducing correctly the logarithmic size dependence of the entanglement entropy in a critical system. The method can be generalized to non-Hamiltonian systems and to the calculation of low-lying excited states, dynamical correlation functions, and other physical properties of strongly correlated systems.展开更多
Five novel donor-acceptor （D-A） conjugated cooligomers （F4B-hP, F5B-hP, F5B2[1,2]-hP, F5B2[I,3]-hP and F7B2[1,2]-hP） were synthesized. The absorption spectra of the cooligomers cover a wide range from 300 nm to 63...Five novel donor-acceptor （D-A） conjugated cooligomers （F4B-hP, F5B-hP, F5B2[1,2]-hP, F5B2[I,3]-hP and F7B2[1,2]-hP） were synthesized. The absorption spectra of the cooligomers cover a wide range from 300 nm to 630 nm. The cooligomers could form films featured by alternating D-A lamellar nanostructures with the periods relative to the molecular lengths after thermal annealing or solvent vapor annealing. Single molecule solar cells were fabricated, and FSB-hP exhibited the best device performance. When the film of FSB-hP was thermally annealed, a power conversion efficiency （PCE） of 1.56% was realized. With solvent vapor annealing, the PCE could be further improved to 1.72% with a short-circuit current （J_SC） of 5.76 mA/cm2, an open-circuit voltage （Voc） of 0.87 V and a fill factor （FF） of 0.34.展开更多
In this paper, a new D-A copolymer, PFDBCPDT, which consists of benzo-2,1,3-thiadiazole as acceptor units and cyclopentadithiophene and fluorene as donor units, was synthesized. The thermal, electrochemical, photophys...In this paper, a new D-A copolymer, PFDBCPDT, which consists of benzo-2,1,3-thiadiazole as acceptor units and cyclopentadithiophene and fluorene as donor units, was synthesized. The thermal, electrochemical, photophysical and photovoltaic properties of PFDBCPDT were studied. PFDBCPDT showed a low optical band gap of 1.84 eV, and relatively low HOMO level of-5.69 eV. The best device performance was obtained by PFDBCPDT/PC61BM （1：3） with 0.5 vol% DIO. The device exhibited a power conversion efficiency of 3.06%, with a relatively high open circuit voltage of 0.87 eV.展开更多
Four new low-band-gap alternating copolymers （P-1, P-2, P-3 and P-4） based on electron-rich benzodithiophene and newly developed electron-deficient units, thienopyrazine or dithiadiazatrindene derivatives, were synt...Four new low-band-gap alternating copolymers （P-1, P-2, P-3 and P-4） based on electron-rich benzodithiophene and newly developed electron-deficient units, thienopyrazine or dithiadiazatrindene derivatives, were synthesized by Stille polycondensation. All polymers exhibit good solubility in common organic solvents and a broad absorption band in the visible to near-infrared regions. The film optical band gaps of the polymers are in the range of 1.28-2.07 eV and the highest occupied molecular orbital （HOMO） energy levels are in the range of-4.99 eV to -5.28 eV. Bulk heterojunction polymer solar cells （PSCs） of the polymers were fabricated with phenyl-C61-butyric acid methyl ester （PC61BM） as acceptor material, and a power conversion efficiency of 0.80% was realized with P-1 as donor material.展开更多
基金Supported by Peng-Cheng Talent-Medical Young Reserve Talent Training Program,No.XWRCHT20220002Xuzhou City Health and Health Commission Technology Project Contract,No.XWKYHT20230081and Key Research and Development Plan Project of Xuzhou City,No.KC22179.
文摘BACKGROUND Gastric cancer(GC)is prevalent and aggressive,especially when patients have distant lung metastases,which often places patients into advanced stages.By identifying prognostic variables for lung metastasis in GC patients,it may be po-ssible to construct a good prediction model for both overall survival(OS)and the cumulative incidence prediction(CIP)plot of the tumour.AIM To investigate the predictors of GC with lung metastasis(GCLM)to produce nomograms for OS and generate CIP by using cancer-specific survival(CSS)data.METHODS Data from January 2000 to December 2020 involving 1652 patients with GCLM were obtained from the Surveillance,epidemiology,and end results program database.The major observational endpoint was OS;hence,patients were se-parated into training and validation groups.Correlation analysis determined va-rious connections.Univariate and multivariate Cox analyses validated the independent predictive factors.Nomogram distinction and calibration were performed with the time-dependent area under the curve(AUC)and calibration curves.To evaluate the accuracy and clinical usefulness of the nomograms,decision curve analysis(DCA)was performed.The clinical utility of the novel prognostic model was compared to that of the 7th edition of the American Joint Committee on Cancer(AJCC)staging system by utilizing Net Reclassification Improvement(NRI)and Integrated Discrimination Improvement(IDI).Finally,the OS prognostic model and Cox-AJCC risk stratification model modified for the AJCC system were compared.RESULTS For the purpose of creating the OS nomogram,a CIP plot based on CSS was generated.Cox multivariate regression analysis identified eleven significant prognostic factors(P<0.05)related to liver metastasis,bone metastasis,primary site,surgery,regional surgery,treatment sequence,chemotherapy,radiotherapy,positive lymph node count,N staging,and time from diagnosis to treatment.It was clear from the DCA(net benefit>0),time-de-pendent ROC curve(training/validation set AUC>0.7),and calibration curve(reliability slope closer to 45 degrees)results that the OS nomogram demonstrated a high level of predictive efficiency.The OS prediction model(New Model AUC=0.83)also performed much better than the old Cox-AJCC model(AUC difference between the new model and the old model greater than 0)in terms of risk stratification(P<0.0001)and verification using the IDI and NRI.CONCLUSION The OS nomogram for GCLM successfully predicts 1-and 3-year OS.Moreover,this approach can help to ap-propriately classify patients into high-risk and low-risk groups,thereby guiding treatment.
基金the National Research and Development Program of China(Grant Nos.2016YFA0300503 and 2017YFA0302900)the National Natural Science Foundation of China(Grant Nos.12274458,11774420,and 11974194)the Research Funds of Renmin University of China(Grant No.20XNLG19).
文摘Two-dimensional(2D)magnetic materials have attracted tremendous research interest because of the promising application in the next-generation microelectronic devices.Here,by the first-principles calculations,we propose a twodimensional ferromagnetic material with high Curie temperature,manganese tetranitride MnN4monolayer,which is a square-planar lattice made up of only one layer of atoms.The structure is demonstrated to be stable by the phonon spectra and the molecular dynamic simulations,and the stability is ascribed to theπ–d conjugation betweenπorbital of N=N bond and d orbital of Mn.More interestingly,the MnN_(4)monolayer displays robust 2D ferromagnetism,which originates from the strong exchange couplings between Mn atoms due to theπ–d conjugation.The high critical temperature of 247 K is determined by solving the Heisenberg model using the Monte Carlo method.
基金funded by Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)(GML2019ZD0201,GML2019ZD0104)Finance Science and Technology Project of Hainan Province(ZDKJ202019).
文摘Great advancement has been made on natural gas hydrates exploration and test production in the northern South China Sea.However,there remains a lot of key questions yet to be resolved,particularly about the mechanisms and the controls of gas hydrates enrichment.Numerical simulaution would play signficant role in addressing these questions.This study focused on the gas hydrate exploration in the Shenhu Area,Northern South China Sea.Based on the newly obtained borehole and multichannel reflection seismic data,the authors conducted an integrated 3D basin modeling study on gas hydrate.The results indicate that the Shenhu Area has favorable conditions for gas hydrate accumulation,such as temperature,pressure,hydrocarbon source,and tectonic setting.Gas hydrates are most concentrated in the Late Miocene strata,particularly in the structual highs between the Baiyun Sag and the Liwan Sag,and area to the south of it.It also proved the existence of overpressure in the main sag of source rocks,which was subject to compaction disequilibrium and hydrocarbon generation.It also shown that the regional fault activity is not conducive to gas hydrate accumulation due to excess gas seepage.The authors conjecture that fault activity may slightly weaken overpressure for the positive effect of hydrocarbon expulsion and areas lacking regional fault activity have better potential.
基金Project supported by the Fundamental Research Funds for the Central Universities,China(Grant No.531107040857)the Natural Science Foundation of Hunan Province,China(Grant No.851204035)the National Natural Science Foundation of China(Grant No.11774420)
文摘Using the tensor renormalization group method based on the higher-order singular value decomposition, we have studied the phase transitions of the five-state clock model on the square lattice. The temperature dependence of the specific heat indicates the system has two phase transitions, as verified clearly by the correlation function at three representative tem- peratures. By calculating the magnetic susceptibility, we obtained only the upper critical temperature as To2 = 0.9565（7）. Investigating the fixed-point tensor, we precisely locate the transition temperatures at Tcl = 0.9029（1） and Tc2 = 0.9520（1）, consistent well with the Monte Carlo and the density matrix renormalization group results.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11190024 and 11474331)
文摘We propose a generalized Lanczos method to generate the many-body basis states of quantum lattice models using tensor-network states （TNS）. The ground-state wave function is represented as a linear superposition composed from a set of TNS generated by Lanczos iteration. This method improves significantly the accuracy of the tensor-network algorithm and provides an effective way to enlarge the maximal bond dimension of TNS. The ground state such obtained contains significantly more entanglement than each individual TNS, reproducing correctly the logarithmic size dependence of the entanglement entropy in a critical system. The method can be generalized to non-Hamiltonian systems and to the calculation of low-lying excited states, dynamical correlation functions, and other physical properties of strongly correlated systems.
基金financially supported by the National Basic Research Program of China(973 Project,No.2009CB939702)of Chinese Ministry of Science and TechnologyNSFC(Nos.20921061 and 50833004)
文摘Five novel donor-acceptor （D-A） conjugated cooligomers （F4B-hP, F5B-hP, F5B2[1,2]-hP, F5B2[I,3]-hP and F7B2[1,2]-hP） were synthesized. The absorption spectra of the cooligomers cover a wide range from 300 nm to 630 nm. The cooligomers could form films featured by alternating D-A lamellar nanostructures with the periods relative to the molecular lengths after thermal annealing or solvent vapor annealing. Single molecule solar cells were fabricated, and FSB-hP exhibited the best device performance. When the film of FSB-hP was thermally annealed, a power conversion efficiency （PCE） of 1.56% was realized. With solvent vapor annealing, the PCE could be further improved to 1.72% with a short-circuit current （J_SC） of 5.76 mA/cm2, an open-circuit voltage （Voc） of 0.87 V and a fill factor （FF） of 0.34.
基金financially supported by the 973 Project(Nos.2009CB623601and2009CB930603)the Science Fund for Creative Research Groups(No.20921061)the National Natural Science Foundation of China(Nos.51173179,20904055 and21074130)
文摘In this paper, a new D-A copolymer, PFDBCPDT, which consists of benzo-2,1,3-thiadiazole as acceptor units and cyclopentadithiophene and fluorene as donor units, was synthesized. The thermal, electrochemical, photophysical and photovoltaic properties of PFDBCPDT were studied. PFDBCPDT showed a low optical band gap of 1.84 eV, and relatively low HOMO level of-5.69 eV. The best device performance was obtained by PFDBCPDT/PC61BM （1：3） with 0.5 vol% DIO. The device exhibited a power conversion efficiency of 3.06%, with a relatively high open circuit voltage of 0.87 eV.
基金financially supported by the Russian Foundation for Basic Research(GFEN_a No.12-03-91175)the National Natural Science Foundation of China(No.51211120187)
文摘Four new low-band-gap alternating copolymers （P-1, P-2, P-3 and P-4） based on electron-rich benzodithiophene and newly developed electron-deficient units, thienopyrazine or dithiadiazatrindene derivatives, were synthesized by Stille polycondensation. All polymers exhibit good solubility in common organic solvents and a broad absorption band in the visible to near-infrared regions. The film optical band gaps of the polymers are in the range of 1.28-2.07 eV and the highest occupied molecular orbital （HOMO） energy levels are in the range of-4.99 eV to -5.28 eV. Bulk heterojunction polymer solar cells （PSCs） of the polymers were fabricated with phenyl-C61-butyric acid methyl ester （PC61BM） as acceptor material, and a power conversion efficiency of 0.80% was realized with P-1 as donor material.
