How the performance in the course of implementing the logistics network organization is, and how the benefit level is produced, are undoubtedly focuses that cooperative parties pay close attention to, and the key to t...How the performance in the course of implementing the logistics network organization is, and how the benefit level is produced, are undoubtedly focuses that cooperative parties pay close attention to, and the key to the network organization, too. The research on the performance appraisement about the network organization is not only very necessary, but also very important. This paper describes the characteristics of the performance appraisement about the logistics network organization, and sets up the evaluation index through analyzing the principle of constituting the logistics network organization's performance index system.展开更多
BACKGROUND The utility of hepatitis C virus(HCV)organs has increased after the Food and Drug Administration approval of direct acting anti-viral(DAA)medications for the HCV treatment.The efficacy of DAA in treating HC...BACKGROUND The utility of hepatitis C virus(HCV)organs has increased after the Food and Drug Administration approval of direct acting anti-viral(DAA)medications for the HCV treatment.The efficacy of DAA in treating HCV is nearly 100%.AIM To analyze the United Network for Organ Sharing(UNOS)database to compare the survival rates between the hepatitis C positive donors and negative recipients and hepatitis C negative donors and recipients.METHODS We analyzed the adult patients in UNOS database who underwent deceased donor liver transplant from January 2014 to December 2017.The primary endpoint was to compare the survival rates among the four groups with different hepatitis C donor and recipient status:(Group 1)Both donor and recipient negative for HCV(Group 2)Negative donor and positive recipient for HCV(Group 3)Positive donor and negative recipient for HCV(Group 4)Both positive donor and recipient for HCV.SAS 9.4 software was used for the data analysis.Kaplan Meier log rank test was used to analyze the estimated survival rates among the four groups.RESULTS A total of 24512 patients were included:Group 1:16436,Group 2:6174,Group 3:253 and Group 4:1649.The 1-year(Group 1:91.8%,Group 2:92.12%,Group 3:87%,Group 4:92.8%),2-year(Group 1:88.4%,Group 2:88.1%,Group 3:84.3%,Group 4:87.5%),3-year(Group 1:84.9%,Group 2:84.3%,Group 3:75.9%,Group 4:83.2%)survival rates showed no statistical significance among the four groups.Kaplan Meier log rank test did not show any statistical significance difference in the estimated survival rates between Group 3 vs all the other groups.CONCLUSION The survival rates in hepatitis C positive donors and negative recipients are similar as compared to both hepatitis C negative donors and recipients.This could be due to the use of DAA therapy with cure rates of nearly 100%.This study supports the use of hepatitis C positive organs in the selected group of recipients with and without HCV infection.Further long-term studies are needed to further validate these findings.展开更多
By employing a new semi-rigid pyrazole-amide-derived bis(pyridyl)ligand[N,N'-bis(4-picolylamine)-1-hydropyrazole(4-dpap)],a new homopolymolybdate-based two-dimensional(2D)plate-like complex[Co(4-dpap)(H_(2)O)(β-M...By employing a new semi-rigid pyrazole-amide-derived bis(pyridyl)ligand[N,N'-bis(4-picolylamine)-1-hydropyrazole(4-dpap)],a new homopolymolybdate-based two-dimensional(2D)plate-like complex[Co(4-dpap)(H_(2)O)(β-Mo_(8)O_(2)6)1/2](1)has been prepared under solvothermal condition and structurally characterized.Theβ-Mo_(8)anions are fi xed between the 2D metal–organic networks[Co(4-dpap)(H_(2)O)]n 2n+via hydrogen-bonding interaction.Complex 1 possesses satisfactory specifi c capacitance of 1512.4 F·g^(−1)(current density:1 A·g^(−1))and good cycling stability(90.8%after 1000 cycles).Moreover,1 represents a promising amperometric sensor for measurement of Cr(Ⅵ)with low detection limit(0.042μmol·L^(−1))and high durability.The insertion ofβ-Mo_(8)anions between the unique 2D metal−organic networks improves the active area of polyoxometalates,which further promotes electrochemical performance.展开更多
BACKGROUND Early in the coronavirus disease 2019(COVID-19)pandemic,there was a significant impact on routine medical care in the United States,including in fields of transplantation and oncology.AIM To analyze the imp...BACKGROUND Early in the coronavirus disease 2019(COVID-19)pandemic,there was a significant impact on routine medical care in the United States,including in fields of transplantation and oncology.AIM To analyze the impact and outcomes of early COVID-19 pandemic on liver transplantation(LT)for hepatocellular carcinoma(HCC)in the United States.METHODS WHO declared COVID-19 as a pandemic on March 11,2020.We retrospectively analyzed data from the United Network for Organ Sharing(UNOS)database regarding adult LT with confirmed HCC on explant in 2019 and 2020.We defined pre-COVID period from March 11 to September 11,2019,and early-COVID period as from March 11 to September 11,2020.RESULTS Overall,23.5%fewer LT for HCC were performed during the COVID period(518 vs 675,P<0.05).This decrease was most pronounced in the months of March-April 2020 with a rebound in numbers seen from May-July 2020.Among LT recipients for HCC,concurrent diagnosis of non-alcoholic steatohepatitis significantly increased(23 vs 16%)and alcoholic liver disease(ALD)significantly decreased(18 vs 22%)during the COVID period.Recipient age,gender,BMI,and MELD score were statistically similar between two groups,while waiting list time decreased during the COVID period(279 days vs 300 days,P=0.041).Among pathological characteristics of HCC,vascular invasion was more prominent during COVID period(P<0.01),while other features were the same.While the donor age and other characteristics remained same,the distance between donor and recipient hospitals was significantly increased(P<0.01)and donor risk index was significantly higher(1.68 vs 1.59,P<0.01)during COVID period.Among outcomes,90-day overall and graft survival were the same,but 180-day overall and graft were significantly inferior during COVID period(94.7 vs 97.0%,P=0.048).On multivariable Coxhazard regression analysis,COVID period emerged as a significant risk factor of post-transplant mortality(Hazard ratio 1.85;95%CI:1.28-2.68,P=0.001).CONCLUSION During COVID period,there was a significant decrease in LTs performed for HCC.While early postoperative outcomes of LT for HCC were same,the overall and graft survival of LTs for HCC after 180 days were significantly inferior.展开更多
Surface chemical modification of polyolefin separators for lithium ion batteries is attempted to reduce the thermal shrinkage, which is im- portant for the battery energy density. In this study, we grafted organic/ino...Surface chemical modification of polyolefin separators for lithium ion batteries is attempted to reduce the thermal shrinkage, which is im- portant for the battery energy density. In this study, we grafted organic/inorganic hybrid crosslinked networks on the separators, simply by grafting polymerization and condensation reaction. The considerable silicon-oxygen crosslinked heat-resistance networks are responsible for the reduced thermal shrinkage. The strong chemical bonds between networks and separators promise enough mechanical support even at high temperature. The shrinkage at 150 ℃ for 30 min in the mechanical direction was 38.6% and 4.6% for the pristine and present graft-modified separators, respectively. Meanwhile, the grafting organic-inorganic hybrid crosslink networks mainly occupied part of void in the internal pores of the separators, so the thicknesses of the graft-modified separators were similar with the pristine one. The half cells prepared with the modified separators exhibited almost identical electrochemical properties to those with the commercial separators, thus proving that, in order to enhance the thermal stability of lithium ion battery, this kind of grafting-modified separators may be a better alternative to conventional silica nanoparticle layers-coated polyolefin separators.展开更多
The authors of this study note that in liver transplantation(LT),the survival rates of hepatitis C virus(HCV)-positive donors and HCV-negative receivers are compa-rable to those of HCV-negative donors and recipients.D...The authors of this study note that in liver transplantation(LT),the survival rates of hepatitis C virus(HCV)-positive donors and HCV-negative receivers are compa-rable to those of HCV-negative donors and recipients.Direct-acting antiviral(DAA)therapies have nearly 100%effectiveness in treating HCV.Between 2006 and 2016,the percentages of HCV-positive patients on the waiting list and HCVpositive LT recipients fell by 8.2 percent and 7.6 percent,respectively.Records from April 1,2014,in which the donor and receiver were both at least 18 years old and had a positive HCV status,were the only ones eligible for the study.The analysis for this study was restricted to the first transplant recorded for each patient using a data element that documented the number of prior transplants for each recipient,although some recipients appeared multiple times in the data set.HCV-positive recipients or people with fulminant hepatic failure were the main beneficiaries of primary biliary cirrhosis among HCV-positive donors.However,there is still a reticence to use HCV-positive donor organs in HCV recipients due to clinical and ethical considerations.Similar survival rates between HCV-positive donors and recipients and HCV-negative donors and receivers illustrate the efficacy of these DAA regimens.展开更多
In a context where express delivery service is indispensable in urban production and life in China,urban express joint distribution will help reduce the negative impact of logistics activities on urban traffic and env...In a context where express delivery service is indispensable in urban production and life in China,urban express joint distribution will help reduce the negative impact of logistics activities on urban traffic and environment,and eventually promote the coordinated development of the express delivery industry and the city.This paper summarizes the background of urban express joint distribution based on its four driving forces:saving resources,green development,traffic avoidance,and public service.Then it establishes a network structure model of urban express joint distribution based on systems thinking,elaborates the functional orientations of the four layers in the model–the distribution layer,the feeder transport layer,the terminal station layer,and the collection and delivery layer,and discusses the implementation ideas of joint distribution at all layers.Finally,it puts forward four suggestions for promoting the joint distribution:improving inter-departmental coordination mechanism,maintaining a diversified distribution pattern,promoting in-depth cooperation among companies,and practicing a high-tech development path.展开更多
Telemedicine's greatest problem is not found in software and hardware. Many can make software and hardware work. It has for long been clear that telemedicine has diffusion problems. Focus should be shifted over to th...Telemedicine's greatest problem is not found in software and hardware. Many can make software and hardware work. It has for long been clear that telemedicine has diffusion problems. Focus should be shifted over to the humanware. Telemedicine means work is done by virtual organizations. For the future of telemedicine, organizational issues will represent a challenge. Organizations consist of humans in interaction. In Norwegian telemedicine projects, organizational problems were identified and solutions to the problems were designed. More than 40 publications show numerous organizational consequences and numerous types of organizational consequences. When it comes to the solving telemedicine's organizational problems, learning from the experience others have is important. It is not necessary for all to invent what the organizational problems are. Organizing health care around the physical telecommunication networks is associated with the concept of network organization. The electronic networks become an infrastructure around which single health care providers are distributed. Such network organization means a formation of alliances between organizations. Centralization and decentralization are important terms for all organizing. Telemedicine makes the question of centralization or decentralization relevant. Telemedicine requires collaboration between participating parties. Obtaining the benefits of telemedicine is dependent on implementing the right measures for good collaboration. We know there are problems with telemedicine virtual organizations, but solutions to these problems exist. For the future of telemedicine, doing work with organization is important. Skilled managers have an important role to play.展开更多
Managing a large-scale distributed engineering project needs skilled, motivated and committed personnel. Unified and aligned working methods are needed. Project alignment is the process of ensuring that key stakeholde...Managing a large-scale distributed engineering project needs skilled, motivated and committed personnel. Unified and aligned working methods are needed. Project alignment is the process of ensuring that key stakeholders share a common understanding of the project mission, goals, objectives, tactics, work processes and plans and have the required competences and skills. Based on current advances in the area of collaborative networked organizations, project management and Internet web 2.0 technologies, the authors have identified further needs and opportunities for development in the area of Collaborative Project Management. The Project Alignment Booster is a set of software services used to promote collaborative project management. The tool has been developed to suit industrial requirements in the area of large and complicated engineering project management, The paper reports the results of developing a toolkit to support collaborative project alignment.展开更多
Mechanochemistry has been recognized as an efficient and sustainable methodology to provide a unique driven force and reaction environments under ambient and neat conditions for the construction of functionalized mate...Mechanochemistry has been recognized as an efficient and sustainable methodology to provide a unique driven force and reaction environments under ambient and neat conditions for the construction of functionalized materials possessing promising properties.Among them,highly porous conjugated scaffolds with attractive electronic conductivities and high surface areas are one of the representative categories exhibiting diverse taskspecific applications,especially in electrochemical energy storage.In recent years,the mechanochemistry-driven procedures have been deployed to construct conjugated scaffolds with engineered structures and properties leveraging the tunability in chemical structures of building blocks and polymerization capability of diverse catalysts.Therefore,a thorough review of related works is required to gain an in-depth understanding of the mechanochemical synthesis procedure and property-performance relationship of the as-produced conjugated scaffolds.Herein,the mechanochemistry-driven construction of conjugated porous networks(CPNs),the carbon-based materials(e.g.,graphite and graphyne),and carbon supported single atom catalysts(CS-SACs)are discussed and summarized.The electrochemical performance of the afforded conductive scaffolds as electrode materials in supercapacitors and alkali-ion batteries is elucidated.Finally,the challenges and potential opportunities related to the construction of conjugated scaffolds driven by mechanochemistry are also discussed and concluded.展开更多
Fluorinated porous organic networks(F-PONs)have demonstrated unique properties and applications,but approaches capable of affording F-PONs with high fluorine content and robust nanoporous architecture under metal-free...Fluorinated porous organic networks(F-PONs)have demonstrated unique properties and applications,but approaches capable of affording F-PONs with high fluorine content and robust nanoporous architecture under metal-free and easy handling conditions are still rarely reported.Herein,using polydivinylbenzene(PDVB)as an easily available precursor,a novel and straightforward approach was developed to afford F-PONs via a dehydrative Friedel-Crafts reaction using perfluorinated benzylic alcohols as the cross-linking agent promoted by Bronsted acid(trifluoromethanesulfonic acid).The afforded material(F-PDVB)featured high fluorine content(22 at.%),large surface area(771 m^(2)·g^(-1)),and good chemical/thermal stability,rendering them as promising candidates for the adsorption of CO_(2),hydrocarbons,fluorocarbons,and chlorofluorocarbons,with weight capacities up to 520 wt.%being achieved.This simple methodology can be extended to fabricate fluorinated hyper-crosslinked polymers(F-HCPs)from rigid aromatic monomers.The progress made in this work will open new opportunities to further expand the involvement of fluorinated materials in large scale applications.展开更多
Chemotherapy is one of the major approaches for the treatment of metastatic lung cancer.However,systemic chemotherapy is limited by poor therapeutic efficiency and severe toxic side effects,due to the extremely low de...Chemotherapy is one of the major approaches for the treatment of metastatic lung cancer.However,systemic chemotherapy is limited by poor therapeutic efficiency and severe toxic side effects,due to the extremely low delivery efficacy and non-specificity of anticancer drugs.Herein,we report a sericin microparticles enveloped with metal-organic networks as a pulmonary delivery system for treating lung metastasis of breast cancer in an animal model.The sericin microparticles(SMPs)were prepared using water in oil(w/o)emulsification method.After doxorubicin(DOX)loading,tannic acid(TA)/ferric irons(Fe3+)based metal organic networks(MON)were coated on the particles to obtain DOX-loaded microparticles(DOX@SMPs-MON).The SMPs-MON with good biocompatibility could effectively encapsulate DOX and sustainably unload cargos in a pH-dependent manner.The DOX-loaded microparticles could be uptaken by 4T1 cells,and effectively kill the cancer cells.In vivo,DOX@SMPs-MON was deposited in the lungs and remained for over 5 days after pulmonary administration.In contrast to conventional DOX treatment that did not show significantly inhibitory effects on lung metastatic tumor,DOX@SMPs-MON markedly decreased the number and size of metastatic nodules in lungs,and the lung weight and appearance were similar to those of healthy mice.In summary,the sericin microparticles with MON wrapping might be a promising pulmonary delivery system for treating lung metastatic cancer.展开更多
Hydrogen-bonded organic networks(HONs)have attracted intense research interest due to their mild synthesis conditions,good solvent processability and strong reproducibility.Most HONs are constructed by electrically ne...Hydrogen-bonded organic networks(HONs)have attracted intense research interest due to their mild synthesis conditions,good solvent processability and strong reproducibility.Most HONs are constructed by electrically neutral organic ligands through intermo-lecular interactions such as weak hydrogen bonding,n-n stacking.But there are a few charge-assisted hydrogen-bonding networks(CAHONs)constructed by oppositely charged organic components.Under hydrothermal conditions,we successfully synthesized a 3D CAHON(H2CV)(H2BTEC)(1)constructed by H2CV(CV=N,N′-4,4′-bipyridine dipropionate)and H4BTEC(H_(4)BTEC=1,2,4,5-benzene-tetracarboxylic acid)through multiple charge-assisted hydrogen bonding.Upon soft X-ray,ultraviolet light or sunlight irradiation under ambient conditions,1 quickly changes from colorless to blue(IP),and kinetic calculations show that its photochromism meets first-order dynamics.Interestingly,the colored crystals IP with long-lived colored radicals will not fade after being placed for more than two months at room temperature in air,owing to the fact that the photogenerated viologen radicals can be stabilized by the abundant hydrogen bonds,the coplanar pyridinium rings and the slow electron-hole recombination.Moreover,1 is a typical direct band gap semiconductor,evidenced by the calculated band gap of 3.24 eV,in agreement with the experimental value of 3.40 eV.In view of its strong colored stability,1 is designed for distinctive inkless printing.展开更多
Unraveling the nature of complex condensed matter systems is of paramount importance in a variety of fields such as pharmacology and materials science.Here we report the synthesis,by the dynamic covalent chemistry(DCC...Unraveling the nature of complex condensed matter systems is of paramount importance in a variety of fields such as pharmacology and materials science.Here we report the synthesis,by the dynamic covalent chemistry(DCC),of a robust,continuous,and low-defect glassy covalent organic network(GCON).The direct imaging of the molecular structure clearly shows the amorphous nature of GCONs,which consists with the competing(nano)crystallite model,not Zachariasen continuous random networks(Z-CRN).Remarkably,the microscopic friction properties were measured on GCONs by atomic force microscopy(AFM),and the GCONs showed lower friction force in comparison with crystalline covalent organic frameworks(COFs).展开更多
Generalized Farey tree network (GFTN) and generalized Farey organized pyramid network (CFOPN) model are proposed, and their topological characteristics are studied by both theoretical analysis and numerical simula...Generalized Farey tree network (GFTN) and generalized Farey organized pyramid network (CFOPN) model are proposed, and their topological characteristics are studied by both theoretical analysis and numerical simulations, which are in good accordance with each other. Then weighted GFTN is studied using cumulative distributions of its Farey number value, edge weight, and node strength. These results maybe helpful for future theoretical development of hybrid models.展开更多
We report a synthesis of microporous organic nanotube networks(MONNs) by a combination of hyper cross-linking and molecular templating of core-shell bottlebrush copolymers. The intrabrush and interbrush cross-linkin...We report a synthesis of microporous organic nanotube networks(MONNs) by a combination of hyper cross-linking and molecular templating of core-shell bottlebrush copolymers. The intrabrush and interbrush cross-linking of polystyrene(PS) shell layer in the core-shell bottlebrush copolymers led to the formation of micropores and large-sized nanopores(meso/macrospores) in MONNs, respectively, while selective removal of polylactide(PLA) core layer generated mesoporous tubular structure. The size of PLA-templated mesoporous cores and porous structure both at micro-and meso-scale could be controlled by simple tuning of the ratio of core/shell or the PLA core fraction in the bottlebrush precursors. Moreover, the resultant MONNs showed a highly selective adsorption capacity for the positively charged dyes on the basis of multi-porosity and carboxylate group-rich structure. In addition, MONNs also exhibited effective performance in size-selective adsorption of biomacromolecules. This work represents a new avenue for the preparation of MONNs and also provides a new application for molecular bottlebrushes in nanotechnology.展开更多
Bulk density(BD) is an important soil physical property and has significant effect on soil water conservation function. Indirect methods, which are called pedotransfer functions(PTFs), have replaced direct measurement...Bulk density(BD) is an important soil physical property and has significant effect on soil water conservation function. Indirect methods, which are called pedotransfer functions(PTFs), have replaced direct measurement and can acquire the missing data of BD during routine soil surveys. In this study, multiple linear regression(MLR) and artificial neuron network(ANN) methods were used to develop PTFs for predicting BD from soil organic carbon(OC), texture and depth in the Three-River Headwater region of Qinghai Province, China. The performances of the developed PTFs were compared with 14 published PTFs using four indexes, the mean error(ME), standard deviation error(SDE), root mean squared error(RMSE) and coefficient of determination(R^2). Results showed that the performances of published PTFs developed using exponential regression were better than those developed using linear regression from OC. Alexander(1980)-B, Alexander(1980)-A and Manrique and Jones(1991)-B PTFs, which had good predictions, could be applied for the soils in the study area. The PTFs developed using MLR(MLR-PTFs) and ANN(ANN-PTFs) had better soil BD predictions than most of published PTFs. The ANN-PTFs had better performances than the MLR-PTFs and their performances could be improved when soil texture and depth were added as predictor variables. The idea of developing PTFs for predicting soil BD in the study area could provide reference for other areas and the results could lay foundation for the estimation of soil water retention and carbon pool.展开更多
文摘How the performance in the course of implementing the logistics network organization is, and how the benefit level is produced, are undoubtedly focuses that cooperative parties pay close attention to, and the key to the network organization, too. The research on the performance appraisement about the network organization is not only very necessary, but also very important. This paper describes the characteristics of the performance appraisement about the logistics network organization, and sets up the evaluation index through analyzing the principle of constituting the logistics network organization's performance index system.
文摘BACKGROUND The utility of hepatitis C virus(HCV)organs has increased after the Food and Drug Administration approval of direct acting anti-viral(DAA)medications for the HCV treatment.The efficacy of DAA in treating HCV is nearly 100%.AIM To analyze the United Network for Organ Sharing(UNOS)database to compare the survival rates between the hepatitis C positive donors and negative recipients and hepatitis C negative donors and recipients.METHODS We analyzed the adult patients in UNOS database who underwent deceased donor liver transplant from January 2014 to December 2017.The primary endpoint was to compare the survival rates among the four groups with different hepatitis C donor and recipient status:(Group 1)Both donor and recipient negative for HCV(Group 2)Negative donor and positive recipient for HCV(Group 3)Positive donor and negative recipient for HCV(Group 4)Both positive donor and recipient for HCV.SAS 9.4 software was used for the data analysis.Kaplan Meier log rank test was used to analyze the estimated survival rates among the four groups.RESULTS A total of 24512 patients were included:Group 1:16436,Group 2:6174,Group 3:253 and Group 4:1649.The 1-year(Group 1:91.8%,Group 2:92.12%,Group 3:87%,Group 4:92.8%),2-year(Group 1:88.4%,Group 2:88.1%,Group 3:84.3%,Group 4:87.5%),3-year(Group 1:84.9%,Group 2:84.3%,Group 3:75.9%,Group 4:83.2%)survival rates showed no statistical significance among the four groups.Kaplan Meier log rank test did not show any statistical significance difference in the estimated survival rates between Group 3 vs all the other groups.CONCLUSION The survival rates in hepatitis C positive donors and negative recipients are similar as compared to both hepatitis C negative donors and recipients.This could be due to the use of DAA therapy with cure rates of nearly 100%.This study supports the use of hepatitis C positive organs in the selected group of recipients with and without HCV infection.Further long-term studies are needed to further validate these findings.
基金financially supported by the National Natural Science Foundation of China(Nos.22271021,21971024)Liao Ning Revitalization Talents Program(XLYC1902011),which are gratefully acknowledged.
文摘By employing a new semi-rigid pyrazole-amide-derived bis(pyridyl)ligand[N,N'-bis(4-picolylamine)-1-hydropyrazole(4-dpap)],a new homopolymolybdate-based two-dimensional(2D)plate-like complex[Co(4-dpap)(H_(2)O)(β-Mo_(8)O_(2)6)1/2](1)has been prepared under solvothermal condition and structurally characterized.Theβ-Mo_(8)anions are fi xed between the 2D metal–organic networks[Co(4-dpap)(H_(2)O)]n 2n+via hydrogen-bonding interaction.Complex 1 possesses satisfactory specifi c capacitance of 1512.4 F·g^(−1)(current density:1 A·g^(−1))and good cycling stability(90.8%after 1000 cycles).Moreover,1 represents a promising amperometric sensor for measurement of Cr(Ⅵ)with low detection limit(0.042μmol·L^(−1))and high durability.The insertion ofβ-Mo_(8)anions between the unique 2D metal−organic networks improves the active area of polyoxometalates,which further promotes electrochemical performance.
文摘BACKGROUND Early in the coronavirus disease 2019(COVID-19)pandemic,there was a significant impact on routine medical care in the United States,including in fields of transplantation and oncology.AIM To analyze the impact and outcomes of early COVID-19 pandemic on liver transplantation(LT)for hepatocellular carcinoma(HCC)in the United States.METHODS WHO declared COVID-19 as a pandemic on March 11,2020.We retrospectively analyzed data from the United Network for Organ Sharing(UNOS)database regarding adult LT with confirmed HCC on explant in 2019 and 2020.We defined pre-COVID period from March 11 to September 11,2019,and early-COVID period as from March 11 to September 11,2020.RESULTS Overall,23.5%fewer LT for HCC were performed during the COVID period(518 vs 675,P<0.05).This decrease was most pronounced in the months of March-April 2020 with a rebound in numbers seen from May-July 2020.Among LT recipients for HCC,concurrent diagnosis of non-alcoholic steatohepatitis significantly increased(23 vs 16%)and alcoholic liver disease(ALD)significantly decreased(18 vs 22%)during the COVID period.Recipient age,gender,BMI,and MELD score were statistically similar between two groups,while waiting list time decreased during the COVID period(279 days vs 300 days,P=0.041).Among pathological characteristics of HCC,vascular invasion was more prominent during COVID period(P<0.01),while other features were the same.While the donor age and other characteristics remained same,the distance between donor and recipient hospitals was significantly increased(P<0.01)and donor risk index was significantly higher(1.68 vs 1.59,P<0.01)during COVID period.Among outcomes,90-day overall and graft survival were the same,but 180-day overall and graft were significantly inferior during COVID period(94.7 vs 97.0%,P=0.048).On multivariable Coxhazard regression analysis,COVID period emerged as a significant risk factor of post-transplant mortality(Hazard ratio 1.85;95%CI:1.28-2.68,P=0.001).CONCLUSION During COVID period,there was a significant decrease in LTs performed for HCC.While early postoperative outcomes of LT for HCC were same,the overall and graft survival of LTs for HCC after 180 days were significantly inferior.
基金supported by the MOST(Grant No.2013CB934000,2014DFG71590,2011CB935902,2010DFA72760,2011CB711202,2013AA050903,2011AA11A257 and 2011AA11A254)China Postdoctoral Science Foundation(Grant No.2013M530599 and 2013M540929)+2 种基金Tsinghua University Initiative Scientific Research Program(Grant No.2010THZ08116,2011THZ08139,2011THZ01004 and 2012THZ08129)the State Key Laboratory of Automotive Safety and Energy(No.ZZ2012-011)Suzhou(Wujiang)Automotive Research Institute,Tsinghua University,Project No.2012WJ-A-01
文摘Surface chemical modification of polyolefin separators for lithium ion batteries is attempted to reduce the thermal shrinkage, which is im- portant for the battery energy density. In this study, we grafted organic/inorganic hybrid crosslinked networks on the separators, simply by grafting polymerization and condensation reaction. The considerable silicon-oxygen crosslinked heat-resistance networks are responsible for the reduced thermal shrinkage. The strong chemical bonds between networks and separators promise enough mechanical support even at high temperature. The shrinkage at 150 ℃ for 30 min in the mechanical direction was 38.6% and 4.6% for the pristine and present graft-modified separators, respectively. Meanwhile, the grafting organic-inorganic hybrid crosslink networks mainly occupied part of void in the internal pores of the separators, so the thicknesses of the graft-modified separators were similar with the pristine one. The half cells prepared with the modified separators exhibited almost identical electrochemical properties to those with the commercial separators, thus proving that, in order to enhance the thermal stability of lithium ion battery, this kind of grafting-modified separators may be a better alternative to conventional silica nanoparticle layers-coated polyolefin separators.
文摘The authors of this study note that in liver transplantation(LT),the survival rates of hepatitis C virus(HCV)-positive donors and HCV-negative receivers are compa-rable to those of HCV-negative donors and recipients.Direct-acting antiviral(DAA)therapies have nearly 100%effectiveness in treating HCV.Between 2006 and 2016,the percentages of HCV-positive patients on the waiting list and HCVpositive LT recipients fell by 8.2 percent and 7.6 percent,respectively.Records from April 1,2014,in which the donor and receiver were both at least 18 years old and had a positive HCV status,were the only ones eligible for the study.The analysis for this study was restricted to the first transplant recorded for each patient using a data element that documented the number of prior transplants for each recipient,although some recipients appeared multiple times in the data set.HCV-positive recipients or people with fulminant hepatic failure were the main beneficiaries of primary biliary cirrhosis among HCV-positive donors.However,there is still a reticence to use HCV-positive donor organs in HCV recipients due to clinical and ethical considerations.Similar survival rates between HCV-positive donors and recipients and HCV-negative donors and receivers illustrate the efficacy of these DAA regimens.
基金supported by the fund program of the National Natural Science Foundation of China titled Research on the Organization and Evolution of E-Commerce Joint Distribution Service Network Based on Social Channels(71502002)the Soft Science Project of Anhui Province titled Research on Strategies for Developing an E-Commerce Joint Distribution System in Anhui Province(1607a O202059)。
文摘In a context where express delivery service is indispensable in urban production and life in China,urban express joint distribution will help reduce the negative impact of logistics activities on urban traffic and environment,and eventually promote the coordinated development of the express delivery industry and the city.This paper summarizes the background of urban express joint distribution based on its four driving forces:saving resources,green development,traffic avoidance,and public service.Then it establishes a network structure model of urban express joint distribution based on systems thinking,elaborates the functional orientations of the four layers in the model–the distribution layer,the feeder transport layer,the terminal station layer,and the collection and delivery layer,and discusses the implementation ideas of joint distribution at all layers.Finally,it puts forward four suggestions for promoting the joint distribution:improving inter-departmental coordination mechanism,maintaining a diversified distribution pattern,promoting in-depth cooperation among companies,and practicing a high-tech development path.
文摘Telemedicine's greatest problem is not found in software and hardware. Many can make software and hardware work. It has for long been clear that telemedicine has diffusion problems. Focus should be shifted over to the humanware. Telemedicine means work is done by virtual organizations. For the future of telemedicine, organizational issues will represent a challenge. Organizations consist of humans in interaction. In Norwegian telemedicine projects, organizational problems were identified and solutions to the problems were designed. More than 40 publications show numerous organizational consequences and numerous types of organizational consequences. When it comes to the solving telemedicine's organizational problems, learning from the experience others have is important. It is not necessary for all to invent what the organizational problems are. Organizing health care around the physical telecommunication networks is associated with the concept of network organization. The electronic networks become an infrastructure around which single health care providers are distributed. Such network organization means a formation of alliances between organizations. Centralization and decentralization are important terms for all organizing. Telemedicine makes the question of centralization or decentralization relevant. Telemedicine requires collaboration between participating parties. Obtaining the benefits of telemedicine is dependent on implementing the right measures for good collaboration. We know there are problems with telemedicine virtual organizations, but solutions to these problems exist. For the future of telemedicine, doing work with organization is important. Skilled managers have an important role to play.
文摘Managing a large-scale distributed engineering project needs skilled, motivated and committed personnel. Unified and aligned working methods are needed. Project alignment is the process of ensuring that key stakeholders share a common understanding of the project mission, goals, objectives, tactics, work processes and plans and have the required competences and skills. Based on current advances in the area of collaborative networked organizations, project management and Internet web 2.0 technologies, the authors have identified further needs and opportunities for development in the area of Collaborative Project Management. The Project Alignment Booster is a set of software services used to promote collaborative project management. The tool has been developed to suit industrial requirements in the area of large and complicated engineering project management, The paper reports the results of developing a toolkit to support collaborative project alignment.
基金supported by the U.S.Department of Energy,Office of Science,Basic Energy Sciences,Materials Sciences,and Engineering Division
文摘Mechanochemistry has been recognized as an efficient and sustainable methodology to provide a unique driven force and reaction environments under ambient and neat conditions for the construction of functionalized materials possessing promising properties.Among them,highly porous conjugated scaffolds with attractive electronic conductivities and high surface areas are one of the representative categories exhibiting diverse taskspecific applications,especially in electrochemical energy storage.In recent years,the mechanochemistry-driven procedures have been deployed to construct conjugated scaffolds with engineered structures and properties leveraging the tunability in chemical structures of building blocks and polymerization capability of diverse catalysts.Therefore,a thorough review of related works is required to gain an in-depth understanding of the mechanochemical synthesis procedure and property-performance relationship of the as-produced conjugated scaffolds.Herein,the mechanochemistry-driven construction of conjugated porous networks(CPNs),the carbon-based materials(e.g.,graphite and graphyne),and carbon supported single atom catalysts(CS-SACs)are discussed and summarized.The electrochemical performance of the afforded conductive scaffolds as electrode materials in supercapacitors and alkali-ion batteries is elucidated.Finally,the challenges and potential opportunities related to the construction of conjugated scaffolds driven by mechanochemistry are also discussed and concluded.
基金supported financially by the Division of Chemical Sciences,Geosciences,and Biosciences,Office of Basic Energy Sciences,US Department of Energy.
文摘Fluorinated porous organic networks(F-PONs)have demonstrated unique properties and applications,but approaches capable of affording F-PONs with high fluorine content and robust nanoporous architecture under metal-free and easy handling conditions are still rarely reported.Herein,using polydivinylbenzene(PDVB)as an easily available precursor,a novel and straightforward approach was developed to afford F-PONs via a dehydrative Friedel-Crafts reaction using perfluorinated benzylic alcohols as the cross-linking agent promoted by Bronsted acid(trifluoromethanesulfonic acid).The afforded material(F-PDVB)featured high fluorine content(22 at.%),large surface area(771 m^(2)·g^(-1)),and good chemical/thermal stability,rendering them as promising candidates for the adsorption of CO_(2),hydrocarbons,fluorocarbons,and chlorofluorocarbons,with weight capacities up to 520 wt.%being achieved.This simple methodology can be extended to fabricate fluorinated hyper-crosslinked polymers(F-HCPs)from rigid aromatic monomers.The progress made in this work will open new opportunities to further expand the involvement of fluorinated materials in large scale applications.
基金the National Natural Science Foundation of China(81773104,81773263,81873931,81974382 and 21708008)the Natural Science Foundation Program of Hubei Province(2017CFB652 and 2018CFB474)+2 种基金the Fundamental Research Funds for the Central Universities(2017KFYXJJ241)the Integrated Innovative Team for Major Human Diseases Program of Tongji Medical College of HUST,and Health Commission of Hubei Province scientific research project(WJ2019M155)the Graduates'Innovation Fund of Huazhong University of Science and Technology(2019ygscxcy069).
文摘Chemotherapy is one of the major approaches for the treatment of metastatic lung cancer.However,systemic chemotherapy is limited by poor therapeutic efficiency and severe toxic side effects,due to the extremely low delivery efficacy and non-specificity of anticancer drugs.Herein,we report a sericin microparticles enveloped with metal-organic networks as a pulmonary delivery system for treating lung metastasis of breast cancer in an animal model.The sericin microparticles(SMPs)were prepared using water in oil(w/o)emulsification method.After doxorubicin(DOX)loading,tannic acid(TA)/ferric irons(Fe3+)based metal organic networks(MON)were coated on the particles to obtain DOX-loaded microparticles(DOX@SMPs-MON).The SMPs-MON with good biocompatibility could effectively encapsulate DOX and sustainably unload cargos in a pH-dependent manner.The DOX-loaded microparticles could be uptaken by 4T1 cells,and effectively kill the cancer cells.In vivo,DOX@SMPs-MON was deposited in the lungs and remained for over 5 days after pulmonary administration.In contrast to conventional DOX treatment that did not show significantly inhibitory effects on lung metastatic tumor,DOX@SMPs-MON markedly decreased the number and size of metastatic nodules in lungs,and the lung weight and appearance were similar to those of healthy mice.In summary,the sericin microparticles with MON wrapping might be a promising pulmonary delivery system for treating lung metastatic cancer.
基金the NSFC(Grants 22075168,21701105,21871167&91961201)the 1331 Project of Shanxi Province.
文摘Hydrogen-bonded organic networks(HONs)have attracted intense research interest due to their mild synthesis conditions,good solvent processability and strong reproducibility.Most HONs are constructed by electrically neutral organic ligands through intermo-lecular interactions such as weak hydrogen bonding,n-n stacking.But there are a few charge-assisted hydrogen-bonding networks(CAHONs)constructed by oppositely charged organic components.Under hydrothermal conditions,we successfully synthesized a 3D CAHON(H2CV)(H2BTEC)(1)constructed by H2CV(CV=N,N′-4,4′-bipyridine dipropionate)and H4BTEC(H_(4)BTEC=1,2,4,5-benzene-tetracarboxylic acid)through multiple charge-assisted hydrogen bonding.Upon soft X-ray,ultraviolet light or sunlight irradiation under ambient conditions,1 quickly changes from colorless to blue(IP),and kinetic calculations show that its photochromism meets first-order dynamics.Interestingly,the colored crystals IP with long-lived colored radicals will not fade after being placed for more than two months at room temperature in air,owing to the fact that the photogenerated viologen radicals can be stabilized by the abundant hydrogen bonds,the coplanar pyridinium rings and the slow electron-hole recombination.Moreover,1 is a typical direct band gap semiconductor,evidenced by the calculated band gap of 3.24 eV,in agreement with the experimental value of 3.40 eV.In view of its strong colored stability,1 is designed for distinctive inkless printing.
基金This work was financially supported by the National Science Foundation of China(Nos.52073208,21872103,and 51633006)the Ministry of Science and Technology of China(No 2016YFB0401100).
文摘Unraveling the nature of complex condensed matter systems is of paramount importance in a variety of fields such as pharmacology and materials science.Here we report the synthesis,by the dynamic covalent chemistry(DCC),of a robust,continuous,and low-defect glassy covalent organic network(GCON).The direct imaging of the molecular structure clearly shows the amorphous nature of GCONs,which consists with the competing(nano)crystallite model,not Zachariasen continuous random networks(Z-CRN).Remarkably,the microscopic friction properties were measured on GCONs by atomic force microscopy(AFM),and the GCONs showed lower friction force in comparison with crystalline covalent organic frameworks(COFs).
基金supported by the Nature Science Foundation of China under Grand Nos. 70431002, 60874087, 60773120, and 10647001the Nature Science Foundation of Beijing under Grand No. 4092040
文摘Generalized Farey tree network (GFTN) and generalized Farey organized pyramid network (CFOPN) model are proposed, and their topological characteristics are studied by both theoretical analysis and numerical simulations, which are in good accordance with each other. Then weighted GFTN is studied using cumulative distributions of its Farey number value, edge weight, and node strength. These results maybe helpful for future theoretical development of hybrid models.
基金financially supported by the National Natural Science Foundation of China (Nos. 51273066 and 21574042)Shanghai Pujiang Program (No. 13PJ1402300)
文摘We report a synthesis of microporous organic nanotube networks(MONNs) by a combination of hyper cross-linking and molecular templating of core-shell bottlebrush copolymers. The intrabrush and interbrush cross-linking of polystyrene(PS) shell layer in the core-shell bottlebrush copolymers led to the formation of micropores and large-sized nanopores(meso/macrospores) in MONNs, respectively, while selective removal of polylactide(PLA) core layer generated mesoporous tubular structure. The size of PLA-templated mesoporous cores and porous structure both at micro-and meso-scale could be controlled by simple tuning of the ratio of core/shell or the PLA core fraction in the bottlebrush precursors. Moreover, the resultant MONNs showed a highly selective adsorption capacity for the positively charged dyes on the basis of multi-porosity and carboxylate group-rich structure. In addition, MONNs also exhibited effective performance in size-selective adsorption of biomacromolecules. This work represents a new avenue for the preparation of MONNs and also provides a new application for molecular bottlebrushes in nanotechnology.
基金supported by the National Key Technology R&D Program of China(No.2009BAC61B01)the National Basic Research Program(973Program) of China(No.2012CB95570002)the Innovative Team(Investigation and Management for Agricultural Land Resource) of Predominant Science and Technology in Chinese Academy of Agricultural Engineering
文摘Bulk density(BD) is an important soil physical property and has significant effect on soil water conservation function. Indirect methods, which are called pedotransfer functions(PTFs), have replaced direct measurement and can acquire the missing data of BD during routine soil surveys. In this study, multiple linear regression(MLR) and artificial neuron network(ANN) methods were used to develop PTFs for predicting BD from soil organic carbon(OC), texture and depth in the Three-River Headwater region of Qinghai Province, China. The performances of the developed PTFs were compared with 14 published PTFs using four indexes, the mean error(ME), standard deviation error(SDE), root mean squared error(RMSE) and coefficient of determination(R^2). Results showed that the performances of published PTFs developed using exponential regression were better than those developed using linear regression from OC. Alexander(1980)-B, Alexander(1980)-A and Manrique and Jones(1991)-B PTFs, which had good predictions, could be applied for the soils in the study area. The PTFs developed using MLR(MLR-PTFs) and ANN(ANN-PTFs) had better soil BD predictions than most of published PTFs. The ANN-PTFs had better performances than the MLR-PTFs and their performances could be improved when soil texture and depth were added as predictor variables. The idea of developing PTFs for predicting soil BD in the study area could provide reference for other areas and the results could lay foundation for the estimation of soil water retention and carbon pool.