Impact of utilization of hepatitis C positive organs in liver transplant:Analysis of united network for organ sharing database

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.

Inferior outcomes of liver transplantation for hepatocellular carcinoma during early-COVID-19 pandemic in the United States

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.

A homopolymolybdate-supported plate-like 2D cobalt network constructed from a new pyrazole-amide-pyridyl ligand: highly electrochemical activity in both capacitive performance and the detection of Cr(Ⅵ)

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.

Surface modification of polyolefin separators for lithium ion batteries to reduce thermal shrinkage without thickness increase

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.

Analysis of hepatitis C virus-positive organs in liver transplantation

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.

Construction of conjugated scaffolds driven by mechanochemistry towards energy storage applications

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.

Robust perfluorinated porous organic networks: Succinct synthetic strategy and application in chlorofluorocarbons adsorption

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.

Sericin microparticles enveloped with metal-organic networks as a pulmonary targeting delivery system for intra-tracheally treating metastatic lung cancer

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.

Microporous Organic Nanotube Networks from Hyper Cross-linking Core-shell Bottlebrush Copolymers for Selective Adsorption Study

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.

A Photo-Responsive Charge-Assisted Hydrogen-Bonded Organic Network with Ultra-Stable Viologen Radicals

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.

Construction and nanotribological study of a glassy covalent organic network on surface

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).

城市快递共同配送的演进动力与网络组织研究

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.