The hydrocarbon generation effectiveness of lacustrine limestone has been gradually proven. The Da'anzhai Member limestone is the most important Jurassic oil-producing layer in the central Sichuan Basin, and the c...The hydrocarbon generation effectiveness of lacustrine limestone has been gradually proven. The Da'anzhai Member limestone is the most important Jurassic oil-producing layer in the central Sichuan Basin, and the characteristics of limestone organic matter are often overlooked. 175 typical samples of different lithologies from 19 wells were systematically analyzed to determine hydrocarbon generation, controlling factors and formation models by analyses of organic matter, minerals, elements, isotopes and petrography. (1) Lacustrine paleoenvironments can be beneficial for the enrichment of organic matter in limestone. A favorable environment would be a quiet, low-energy zone in a warm and humid climate with an appropriate supply of terrestrial inputs. (2) Lacustrine limestone has a higher organic matter conversion rate, and a lower hydrocarbon generation threshold than argillaceous source rocks, and can be effective source rock. (3) The mud-bearing shell limestone from the forebeach to the lake slope is thick, with a relatively high abundance of organic matter, and its hydrocarbon generation is effective. This study can clarify the effectiveness and enrichment of the limestone organic matters in the study area, and contribute to an understanding of hydrocarbon generation for full-rock system in a lacustrine mixed sedimentary environment.展开更多
AIM: To optimize the perfusates used for hypothermicmachine perfusion(HMP).METHODS: Sprague-Dawley rats were assigned randomly to three groups(n = 12 per group) that received either saline, University of Wisconsin col...AIM: To optimize the perfusates used for hypothermicmachine perfusion(HMP).METHODS: Sprague-Dawley rats were assigned randomly to three groups(n = 12 per group) that received either saline, University of Wisconsin coldstorage solution(UW) or histidine-tryptophan-ketoglutarate solution(HTK) as the perfusate. Each group was divided into two subgroups: static cold storage(SCS) and HMP(n = 6 per subgroup). The liver graft was retrieved according to the method described by Kamada. For the SCS group, the graft was directly placed into cold perfusate(0-4?℃) for 6 h after liver isolation while the portal vein of the graft was connected to the perfusion machine for the HMP group. Then the perfusates were collected at different time points for analysis of aspartate aminotransferase(AST), alanine transaminase(ALT) and lactate dehydrogenase(LDH) levels. Liver tissues were obtained for evaluation of histology, dry/wet weight(D/W) ratio, and malondialdehyde(MDA) and adenosine-triphosphate(ATP) levels. The portal vein pressure and velocity were monitored in real time in all HMP subgroups.RESULTS: Comparison of HMP and SCS: Regardless of the perfusate, HMP improved the architecture of donor graft in reducing the congestion around sinusoids and central vein and maintaining sinusoid lining in morphology; HMP improved liver function in terms of ALT, AST and LDH, especially during the 3-6 h period(SCS vs HMP using saline: ALT3, 225.00 ± 105.62 vs 49.50 ± 18.50, P = 0.047; LDH3, 1362.17 ± 563.30 vs 325.75 ± 147.43, P = 0.041; UW: LDH6, 2880.14 ± 948.46 vs 2135.00 ± 174.27, P = 0.049; HTK, AST6, 307.50 ± 52.95 vs 185.20 ± 20.46, P = 0.041); HMP decreased MDA level(saline, 2.79 ± 0.30 vs 1.09 ± 0.09, P = 0.008; UW, 3.01 ± 0.77 vs 1.23 ± 0.68, P = 0.005; HTK, 3.30 ± 0.52 vs 1.56 ± 0.22, P = 0.006). Comparison among HMP subgroups: HTK showed less portal vein resistance than UW and saline(vs saline, 3.41 ± 0.49 vs 5.00 ± 0.38, P < 0.001; vs UW, 3.41 ± 0.49 vs 4.52 ± 0.63, P = 0.007); UW reduced edema most efficiently(vs saline, 0.68 ± 0.02 vs 0.79 ± 0.05, P = 0.013), while HTK maintained ATP levels best(vs saline, 622.60 ± 29.11 vs 327.43 ± 44.66, P < 0.001; vs UW, 622.60 ± 29.11 vs 301.80 ± 37.68, P < 0.001).CONCLUSION: HMP is superior to SCS in maintaining both architecture and function of liver grafts. Further, HTK was found to be the optimal perfusate for HMP.展开更多
AIM To investigate 30-year treatment outcomes associated with Budd-Chiari syndrome(BCS) at a tertiary hospital in China.METHODS A total of 256 patients diagnosed with primary BCS at our tertiary hospital between Novem...AIM To investigate 30-year treatment outcomes associated with Budd-Chiari syndrome(BCS) at a tertiary hospital in China.METHODS A total of 256 patients diagnosed with primary BCS at our tertiary hospital between November 1983 and September 2013 were followed and retrospectively studied. Cumulative survival rates and cumulative mortality rates of major causes were calculated by Kaplan-Meier analysis, and the independent predictors of survival were identified using a Cox regression model. RESULTS Thirty-four patients were untreated; however, 222 patients were treated by medicine, surgery, or interventional radiology. Forty-four patients were lost to follow-up; however, 212 patients were followed, 67 of whom died. The symptom remission rates of treated and untreated patients were 81.1%(107/132) and 46.2%(6/13), respectively(P = 0.009). The cumulative 1-, 5-, 10-, 20-, and 30-year survival rates of the treated patients were 93.5%, 81.6%, 75.2%, 64.7%, and 58.2%, respectively; however, the 1-, 5-, 10-, 20-, and 30-year survival rates of the untreated patients were 70.8%, 70.8%, 53.1%, 0%, and unavailable, respectively(P = 0.007). Independent predictors of survival for treated patients were gastroesophageal variceal bleeding(HR = 3.043, 95%CI: 1.363-6.791, P = 0.007) and restenosis(HR = 4.610, 95%CI: 1.916-11.091, P = 0.001). The cumulative 1-, 5-, 10-, 20-, and 30-year mortality rates for hepatocellular carcinoma were 0%, 2.6%, 3.5%, 8%, and 17.4%, respectively.CONCLUSION Long-term survival is satisfactory for treated Chinese patients with BCS. Hepatocellular carcinoma is a chronic complication and should be monitored with long-term follow-up.展开更多
BACKGROUND The presence of significant liver fibrosis in hepatitis B virus(HBV)-infected individuals with persistently normal serum alanine aminotransferase(PNALT)levels is a strong indicator for initiating antiviral ...BACKGROUND The presence of significant liver fibrosis in hepatitis B virus(HBV)-infected individuals with persistently normal serum alanine aminotransferase(PNALT)levels is a strong indicator for initiating antiviral therapy.Serum ceruloplasmin(CP)is negatively correlated with liver fibrosis in HBV-infected individuals.AIM To examine the potential value of serum CP and develop a noninvasive index including CP to assess significant fibrosis among HBV-infected individuals with PNALT.METHODS Two hundred and seventy-five HBV-infected individuals with PNALT were retrospectively evaluated.The association between CP and fibrotic stages was statistically analyzed.A predictive index including CP[Ceruloplasmin hepatitis B virus(CPHBV)]was constructed to predict significant fibrosis and compared to previously reported models.RESULTS Serum CP had an inverse correlation with liver fibrosis(r=-0.600).Using CP,the areas under the curves(AUCs)to predict significant fibrosis,advanced fibrosis,and cirrhosis were 0.774,0.812,and 0.853,respectively.The CPHBV model was developed using CP,platelets(PLT),and HBsAg levels to predict significant fibrosis.The AUCs of this model to predict significant fibrosis,advanced fibrosis,and cirrhosis were 0.842,0.920,and 0.904,respectively.CPHBV was superior to previous models like the aspartate aminotransferase(AST)-to-PLT ratio index,Fibrosis-4 score,gamma-glutamyl transpeptidase-to-PLT ratio,Forn’s score,and S-index in predicting significant fibrosis in HBV-infected individuals with PNALT.CONCLUSION CPHBV could accurately predict liver fibrosis in HBV-infected individuals with PNALT.Therefore,CPHBV can be a valuable tool for antiviral treatment decisions.展开更多
BACKGROUND Budd-Chiari syndrome is defined as hepatic venous outflow tract obstruction.For Asian Budd-Chiari syndrome patients,the major treatment modality is recanalization(percutaneous transluminal angioplasty with ...BACKGROUND Budd-Chiari syndrome is defined as hepatic venous outflow tract obstruction.For Asian Budd-Chiari syndrome patients,the major treatment modality is recanalization(percutaneous transluminal angioplasty with or without stent implantation).The cumulative 1-,5-,and 10-year primary patency rates and survival rates are reported to be excellent or satisfactory,but the long-term outcome of patients with restenosis(the most common complication after recanalization)is unknown.AIM To explore the treatment strategy for restenosis in patients with Budd-Chiari syndrome after interventional therapy and to evaluate the long-term follow-up results.METHODS The clinical data and follow-up results of 60 patients with restenosis after interventional therapy from November 1983 to December 2013 were retrospectively analyzed.RESULTS Sixty patients with restenosis were retrospectively divided into a percutaneous transluminal angioplasty(PTA)group(40 patients)and a PTA+stent group(20 patients)according to the primary recanalization method.For the patients with restenosis in the PTA group,13 refused treatment,and 27 received further treatment;among these patients,five had a second restenosis,two had a third restenosis,and one had a fourth restenosis.For the patients with restenosis in the PTA+stent group,nine refused treatment,ten received PTA alone,and the other received PTA+stent implantation.Among the patients who received further treatment,five had a second restenosis,three had a third restenosis,and one had a fourth restenosis.The 1-,5-,10-,20-,and 25-year cumulative survival rates of the 38 patients who received further treatment after restenosis were 100%,78.3%,78.3%,70.5%,and 70.5%,respectively;however,for the 22 patients who refused treatment,the survival rates were 72.7%,45.9%,30.6%,10.2%,and unavailable,respectively(P<0.001).CONCLUSION Long-term follow-up after interventional therapy is very important.Active treatment for patients with restenosis can improve prognosis,and minimally invasive treatment strategies for restenosis allows to obtain satisfactory results.展开更多
Transmission efficiency(TE) and focal ratio degradation(FRD) are two important parameters for evaluating the quality of an optical fiber system used for astronomy. Compared to TE, the focal ratio is more easily influe...Transmission efficiency(TE) and focal ratio degradation(FRD) are two important parameters for evaluating the quality of an optical fiber system used for astronomy. Compared to TE, the focal ratio is more easily influenced by external factors, such as bending or stress. Optical cables are widely implemented for multi-object telescopes and integral field units(IFUs). The design and fabrication process of traditional optical cables seldom considers the requirements of astronomical applications. In this paper, we describe a fiber bundle structure as the basic unit for miniaturized high-density FASOT-IFU optical cables,instead of the micro-tube structure in stranded cables. Seven fibers with hexagonal arrangement were accurately positioned by ultraviolet(UV)-curing acrylate to form the bundle. The coating diameter of a fiber is0.125 mm, and the outer diameter of the bundle is 0.58 mm. Compared with the 0.8 mm micro-tube structure of a traditional stranded cable, the outer diameter of the fiber bundle was reduced by 27.5%. Fiber paste was filled into the bundle to reduce stress between the fibers. We tested the output focal ratio(OFR) in95% of the encircled energy(EE95) of the fibers in the bundle under different conditions. With the incident focal ratio F/8, the maximum difference of OFR is 0.6. In particular, when the incident focal ratio is F/5,the maximum difference of OFR is only 0.1. The jacket formed by the UV-curing acrylate can withstand a certain stress of less than 1.38 N mm-1. The fiber bundle can maintain uniform emitting characteristics with a bending radius of 7.5 cm and with tension less than 6 N. The test results show that the structure of the fiber bundle can be used as a basic unit for miniaturized high-density astronomical optical cables.展开更多
Rice husk (biomass fuel) samples have been dried in drying oven and a series of drying curve for illustrating moisture migration of rice husk have been obtained. It is first research for rice husk drying,and it can pr...Rice husk (biomass fuel) samples have been dried in drying oven and a series of drying curve for illustrating moisture migration of rice husk have been obtained. It is first research for rice husk drying,and it can provide reference of fuel processing for different boilers which require rice husk with various water contents. In this paper,we apply Page equation to reflect the drying process and obtain drying characteristic curve,then analyze the drying law. Kinetic analysis of the results of moisture migration test has been done,after which, effective moisture diffusion coefficient,activation energy and drying kinetic equation of rice husk samples are obtained in test temperature range (80 - 130 ℃) . And these results show specific influence law of temperature for effective moisture diffusion coefficient.展开更多
A V-folded digital laser using a spatial light modulator(SLM)for intra-cavity loss shaping is exploited to generate Hermite-Gaussian modes with on-demand mode order.With aπ/2 astigmatic mode converter,vortex beams ca...A V-folded digital laser using a spatial light modulator(SLM)for intra-cavity loss shaping is exploited to generate Hermite-Gaussian modes with on-demand mode order.With aπ/2 astigmatic mode converter,vortex beams carrying on-demand orbital angular momentum(OAM)with a tunable range from-11h to 12 h are obtained.The mode order of the HG mode,hence the OAM of the vortex beam,is digitally switched by changing the phase pattern imposed on the SLM without requiring any mechanic alignment of the cavity.This work has great potential applications in various OAM-tunable vortex beams.展开更多
Carbonized metallic organic frameworks(CMOF)have been attracting attention in microwave absorption(MA)research area because of their diverse structures,tunable compositions,and rich porosity.Herein,structure regulatio...Carbonized metallic organic frameworks(CMOF)have been attracting attention in microwave absorption(MA)research area because of their diverse structures,tunable compositions,and rich porosity.Herein,structure regulation on metal clusters in CMOF is achieved by tuning the interaction strength between metals and ligands to enhance microwave absorption performance.Due to relatively weak interaction among copper cations and ligands,copper nanoclusters(CuNC)can be uniformly formed and embedded within the cobalt/zinc(Co/Zn)CMOF.Firstly,copper cations are added to the Co/Zn bimetallic zeolitic imidazolate frameworks(ZIFs).Secondly,the CMOF composite particles with CuNCs(CuNCs/CoZn-CMOF)were developed by a pyrolysis process.The CuNCs/CoZn-CMOF with an appropriate amount of CuNCs can harmonize both dielectric and magnetic losses.As a result,the minimum reflection loss(RLmin)reaches–45.1 dB at a matching thickness of 2.30 mm and the effective absorption bandwidth(EAB)is 8.80 GHz at a thickness of 3.10 mm.The broadband response to electromagnetic waves is attributed to interfacial polarization at CuNCs surface and heterogeneous interfaces,impedance matching and multiple scattering of electromagnetic waves.This study provides a feasible method to develop CMOF microwave absorption materials with high EAB values.展开更多
Artificial synapses and neurons are crucial milestones for neuromorphic computing hardware,and memristors with resistive and threshold switching characteristics are regarded as the most promising candidates for the co...Artificial synapses and neurons are crucial milestones for neuromorphic computing hardware,and memristors with resistive and threshold switching characteristics are regarded as the most promising candidates for the construction of hardware neural networks.However,most of the memristors can only operate in one mode,that is,resistive switching or threshold switching,and distinct memristors are required to construct fully memristive neuromorphic computing hardware,making it more complex for the fabrication and integration of the hardware.Herein,we propose a flexible dual-mode memristor array based on core–shell CsPbBr3@graphdiyne nanocrystals,which features a 100%transition yield,small cycle-to-cycle and device-to-device variability,excellent flexibility,and environmental stability.Based on this dual-mode memristor,homo-material-based fully memristive neuromorphic computing hardware—a power-free artificial nociceptive signal processing system and a spiking neural network—are constructed for the first time.Our dual-mode memristors greatly simplify the fabrication and integration of fully memristive neuromorphic systems.展开更多
High-performance low-k and low-loss circuit materials are urgently needed in the field of microelectronics due to the upcoming FifthGeneration Mobile Communications Technology(5 G Technology).Herein,a facile design st...High-performance low-k and low-loss circuit materials are urgently needed in the field of microelectronics due to the upcoming FifthGeneration Mobile Communications Technology(5 G Technology).Herein,a facile design strategy for non-fluorinated intrinsic low-k and low-loss polyimides is reported by fully considering the secondary relaxation behaviors of the polymer chains.A new amorphous non-fluorinated polymer(TmBPPA)with a k value of 2.23 and a loss tangent lower than 3.94×10^-3 at 104 Hz has been designed and synthesized,which to the best of our knowledge is the lowest value amongst the non-fluorinated and non-porous polymers reported in literature.Meanwhile,TmBPPA exhibits excellent overall properties,such as excellent thermostability,good mechanical properties,low moisture absorption,and high bonding strength.As high-performance flexible circuit materials,all these characteristics are highly expected to meet the present and future demands for high density,high speed,and high frequency electronic circuit used in 5 G wireless networks.展开更多
Graphdiyne(GDY)is emerging as a promising material for various applications owing to its unique structure and fascinating properties.However,the application of GDY in electronics and optoelectronics are still in its i...Graphdiyne(GDY)is emerging as a promising material for various applications owing to its unique structure and fascinating properties.However,the application of GDY in electronics and optoelectronics are still in its infancy,primarily owing to the huge challenge in the synthesis of large-area and uniform GDY film for scalable applications.Here a modified van der Waals epitaxy strategy is proposed to synthesize wafer-scale GDY film with high uniformity and controllable thickness directly on graphene(Gr)surface,providing an ideal platform to construct large-scale GDY/Gr-based optoelectronic synapse array.Essential synaptic behaviors have been realized,and the linear and symmetric conductance-update characteristics facilitate the implementation of neuromorphic computing for image recognition with high accuracy and strong fault tolerance.Logic functions including“NAND”and“NOR”are integrated into the synapse which can be executed in an optical pathway.Moreover,a visible information sensing-memory-processing system is constructed to execute real-time image acquisition,in situ image memorization and distinction tasks,avoiding the time latency and energy consumption caused by data conversion and transmission in conventional visual systems.These results highlight the potential of GDY in applications of neuromorphic computing and artificial visual systems.展开更多
Direct growth of large area uniform graphene on functional insulating materials is essential for engineering versatile applications of graphene. However, the existing synthesis approaches can hardly avoid the generati...Direct growth of large area uniform graphene on functional insulating materials is essential for engineering versatile applications of graphene. However, the existing synthesis approaches can hardly avoid the generation of non-uniform multilayer graphene along the gas flow direction, affording huge challenges for further scaling up. Herein, by exploiting the molten state of soda-lime glass, we have accomplished the direct growth of large area uniform (up to 30 cm × 6 cm) graphene via a facile chemical vapor deposition route on low cost soda-lime glass. The use of molten glass eliminates the chemically active sites (surface corrugations, scratches, defects), and improves the mobility of carbon precursors, affording uniform nucleation and growth of monolayer graphene. Intriguingly, thus-obtained graphene acts as an ideal coating layer for the surface crystallographic modification of soda-lime glass, making it epitaxy substrates for synthesizing high-quality PbI2 nanoplates and continues films. Accordingly, a prototype photodetector was fabricated to present excellent photoelectrical properties of high responsivity (~ 600 on/off current ratio) and fast response speed (18 μs). This work hereby paves ways for the batch production and the direct applications of graphene glass as platforms for constructing high performance electronic and optoelectronic devices.展开更多
Herein, a low-cost, biodegradable, and high-performance microwave shielding graphite/starch material was fabricated via constructing a cation-π interaction between ammonium ions and graphite. The graphite flakes and ...Herein, a low-cost, biodegradable, and high-performance microwave shielding graphite/starch material was fabricated via constructing a cation-π interaction between ammonium ions and graphite. The graphite flakes and starch were firstly mixed with distilled water containing ammonium hydroxide to form graphite/starch slurry under an ultrasonic assistant. The cation-π interaction could improve delamination degree and dispersion of graphite in starch matrix. The slurry was first used as a coating material on the surface of wood and paper to develop shielding packages. The effect of coating thickness and coating layers on EM shielding property of the materials was investigated. Second, the composites with a high orientation of graphite were fabricated by compression at high pressures. The electrical conductivity and EM shielding effectiveness(SET) of the materials were greatly enhanced by construction of cation-πinteraction and orientation of graphite. Specifically, the EM SETvalues increased from 56.9 to 66.8 d B for the composites with 50 wt.% graphite and 2.0 mm in thickness by constructing cation-π interaction. The EM SETvalues raised from 17.4 to 66.8 d B via the graphite orientation in the materials with the same components and thickness. The shielding mechanism of the compressed composites with orientation dispersion of graphite was also discussed in comparison to the coating layer with random dispersion of graphite.展开更多
Due to the remarkable electronic,optical,thermal,and mechanical properties,graphene-based materials have shown great potential in a wide range of technique applications.Particularly,the high transparency,conductivity,...Due to the remarkable electronic,optical,thermal,and mechanical properties,graphene-based materials have shown great potential in a wide range of technique applications.Particularly,the high transparency,conductivity,flexibility,and abundance make graphene materials highly attractive for polymer solar cells(PSCs).Graphene-based materials have been regarded as one promising candidate used in various parts in PSCs not only as electrodes,but also as interfacial layers and active layers with an aim to boost the power conversion efficiency of the devices.In this review,we summarize the recent progress about the design and synthesis of graphene-based materials for efficient PSCs along with the related challenges and future perspectives.展开更多
A novel method of patterning high precision copper conductive micropatterns on flexible polymer substrate(polyimide)is developed.We utilized the coordination effect between palladium salts and pyridine structures to f...A novel method of patterning high precision copper conductive micropatterns on flexible polymer substrate(polyimide)is developed.We utilized the coordination effect between palladium salts and pyridine structures to fix the palladium chloride(PdCl_(2))on the surface of polymer film while the 2,6-dimethylpyridine structures formed in the specific areas under ultraviolet light guaranteed the resolution of final patterns.Simultaneous thermal reduction of PdCl_(2) on the surface can be achieved in the process of thermal cyclization of the polymer substrate.As a consequence,the obtained polyimide(PI)film can be patterned with conductive copper micropatterns directly by electroless plating.In particular,we accomplished the deposition of high precision copper pattern with a minimum line width of 50μm and minimum line spacing of 20μm on PI thin films(thickness~10μm)by electroless plating.The prepared conductive copper micropatterns exhibit a low resistivity of 1.78μΩ·cm the same as the pure block copper.And the relationship between the structures of the polymer chains and the physical properties of polymer substrates,such as the dimensional stability,mechanical and dielectric properties were also discussed in detail.This simple and novel method of patterning metal on the polymer surface does not need to achieve the catalytic metal adhesion required for electroless plating at the cost of destroying the substrate surface and avoiding the introduction of unstable interlayers.This patterning method is compatible with the current roll-to-roll production process and can be used to develop high-performance micro-integrated circuits.展开更多
基金supported by the National Natural Science Foundation of China(Grants 41902131 and 41821002 and 4169130014).
文摘The hydrocarbon generation effectiveness of lacustrine limestone has been gradually proven. The Da'anzhai Member limestone is the most important Jurassic oil-producing layer in the central Sichuan Basin, and the characteristics of limestone organic matter are often overlooked. 175 typical samples of different lithologies from 19 wells were systematically analyzed to determine hydrocarbon generation, controlling factors and formation models by analyses of organic matter, minerals, elements, isotopes and petrography. (1) Lacustrine paleoenvironments can be beneficial for the enrichment of organic matter in limestone. A favorable environment would be a quiet, low-energy zone in a warm and humid climate with an appropriate supply of terrestrial inputs. (2) Lacustrine limestone has a higher organic matter conversion rate, and a lower hydrocarbon generation threshold than argillaceous source rocks, and can be effective source rock. (3) The mud-bearing shell limestone from the forebeach to the lake slope is thick, with a relatively high abundance of organic matter, and its hydrocarbon generation is effective. This study can clarify the effectiveness and enrichment of the limestone organic matters in the study area, and contribute to an understanding of hydrocarbon generation for full-rock system in a lacustrine mixed sedimentary environment.
基金Supported by National Science and Technology Major Project,No.2012ZX10002-017Natural Science Foundation of China for Innovative Research Group,No.81121002+4 种基金National Natural Science Foundation of China,No.81000137 and No.81470891The Qianjiang Talent Program of Zhejiang Province,China,No.2012R10045the Scientific Research Program for the Returned Overseas Chinese Scholars,Ministry of Health,China,No.J20112008National High Technology Research and Development Program of China for Young Scientists(863 Program),No.2015AA020923Ministry of Education,Zhejiang Province,China,No.Y201328095
文摘AIM: To optimize the perfusates used for hypothermicmachine perfusion(HMP).METHODS: Sprague-Dawley rats were assigned randomly to three groups(n = 12 per group) that received either saline, University of Wisconsin coldstorage solution(UW) or histidine-tryptophan-ketoglutarate solution(HTK) as the perfusate. Each group was divided into two subgroups: static cold storage(SCS) and HMP(n = 6 per subgroup). The liver graft was retrieved according to the method described by Kamada. For the SCS group, the graft was directly placed into cold perfusate(0-4?℃) for 6 h after liver isolation while the portal vein of the graft was connected to the perfusion machine for the HMP group. Then the perfusates were collected at different time points for analysis of aspartate aminotransferase(AST), alanine transaminase(ALT) and lactate dehydrogenase(LDH) levels. Liver tissues were obtained for evaluation of histology, dry/wet weight(D/W) ratio, and malondialdehyde(MDA) and adenosine-triphosphate(ATP) levels. The portal vein pressure and velocity were monitored in real time in all HMP subgroups.RESULTS: Comparison of HMP and SCS: Regardless of the perfusate, HMP improved the architecture of donor graft in reducing the congestion around sinusoids and central vein and maintaining sinusoid lining in morphology; HMP improved liver function in terms of ALT, AST and LDH, especially during the 3-6 h period(SCS vs HMP using saline: ALT3, 225.00 ± 105.62 vs 49.50 ± 18.50, P = 0.047; LDH3, 1362.17 ± 563.30 vs 325.75 ± 147.43, P = 0.041; UW: LDH6, 2880.14 ± 948.46 vs 2135.00 ± 174.27, P = 0.049; HTK, AST6, 307.50 ± 52.95 vs 185.20 ± 20.46, P = 0.041); HMP decreased MDA level(saline, 2.79 ± 0.30 vs 1.09 ± 0.09, P = 0.008; UW, 3.01 ± 0.77 vs 1.23 ± 0.68, P = 0.005; HTK, 3.30 ± 0.52 vs 1.56 ± 0.22, P = 0.006). Comparison among HMP subgroups: HTK showed less portal vein resistance than UW and saline(vs saline, 3.41 ± 0.49 vs 5.00 ± 0.38, P < 0.001; vs UW, 3.41 ± 0.49 vs 4.52 ± 0.63, P = 0.007); UW reduced edema most efficiently(vs saline, 0.68 ± 0.02 vs 0.79 ± 0.05, P = 0.013), while HTK maintained ATP levels best(vs saline, 622.60 ± 29.11 vs 327.43 ± 44.66, P < 0.001; vs UW, 622.60 ± 29.11 vs 301.80 ± 37.68, P < 0.001).CONCLUSION: HMP is superior to SCS in maintaining both architecture and function of liver grafts. Further, HTK was found to be the optimal perfusate for HMP.
文摘AIM To investigate 30-year treatment outcomes associated with Budd-Chiari syndrome(BCS) at a tertiary hospital in China.METHODS A total of 256 patients diagnosed with primary BCS at our tertiary hospital between November 1983 and September 2013 were followed and retrospectively studied. Cumulative survival rates and cumulative mortality rates of major causes were calculated by Kaplan-Meier analysis, and the independent predictors of survival were identified using a Cox regression model. RESULTS Thirty-four patients were untreated; however, 222 patients were treated by medicine, surgery, or interventional radiology. Forty-four patients were lost to follow-up; however, 212 patients were followed, 67 of whom died. The symptom remission rates of treated and untreated patients were 81.1%(107/132) and 46.2%(6/13), respectively(P = 0.009). The cumulative 1-, 5-, 10-, 20-, and 30-year survival rates of the treated patients were 93.5%, 81.6%, 75.2%, 64.7%, and 58.2%, respectively; however, the 1-, 5-, 10-, 20-, and 30-year survival rates of the untreated patients were 70.8%, 70.8%, 53.1%, 0%, and unavailable, respectively(P = 0.007). Independent predictors of survival for treated patients were gastroesophageal variceal bleeding(HR = 3.043, 95%CI: 1.363-6.791, P = 0.007) and restenosis(HR = 4.610, 95%CI: 1.916-11.091, P = 0.001). The cumulative 1-, 5-, 10-, 20-, and 30-year mortality rates for hepatocellular carcinoma were 0%, 2.6%, 3.5%, 8%, and 17.4%, respectively.CONCLUSION Long-term survival is satisfactory for treated Chinese patients with BCS. Hepatocellular carcinoma is a chronic complication and should be monitored with long-term follow-up.
基金the Science and Technology Department of Fujian Province,No.2018J01164Quanzhou Science and Technology Bureau Planning Project,No.2019N019S.
文摘BACKGROUND The presence of significant liver fibrosis in hepatitis B virus(HBV)-infected individuals with persistently normal serum alanine aminotransferase(PNALT)levels is a strong indicator for initiating antiviral therapy.Serum ceruloplasmin(CP)is negatively correlated with liver fibrosis in HBV-infected individuals.AIM To examine the potential value of serum CP and develop a noninvasive index including CP to assess significant fibrosis among HBV-infected individuals with PNALT.METHODS Two hundred and seventy-five HBV-infected individuals with PNALT were retrospectively evaluated.The association between CP and fibrotic stages was statistically analyzed.A predictive index including CP[Ceruloplasmin hepatitis B virus(CPHBV)]was constructed to predict significant fibrosis and compared to previously reported models.RESULTS Serum CP had an inverse correlation with liver fibrosis(r=-0.600).Using CP,the areas under the curves(AUCs)to predict significant fibrosis,advanced fibrosis,and cirrhosis were 0.774,0.812,and 0.853,respectively.The CPHBV model was developed using CP,platelets(PLT),and HBsAg levels to predict significant fibrosis.The AUCs of this model to predict significant fibrosis,advanced fibrosis,and cirrhosis were 0.842,0.920,and 0.904,respectively.CPHBV was superior to previous models like the aspartate aminotransferase(AST)-to-PLT ratio index,Fibrosis-4 score,gamma-glutamyl transpeptidase-to-PLT ratio,Forn’s score,and S-index in predicting significant fibrosis in HBV-infected individuals with PNALT.CONCLUSION CPHBV could accurately predict liver fibrosis in HBV-infected individuals with PNALT.Therefore,CPHBV can be a valuable tool for antiviral treatment decisions.
文摘BACKGROUND Budd-Chiari syndrome is defined as hepatic venous outflow tract obstruction.For Asian Budd-Chiari syndrome patients,the major treatment modality is recanalization(percutaneous transluminal angioplasty with or without stent implantation).The cumulative 1-,5-,and 10-year primary patency rates and survival rates are reported to be excellent or satisfactory,but the long-term outcome of patients with restenosis(the most common complication after recanalization)is unknown.AIM To explore the treatment strategy for restenosis in patients with Budd-Chiari syndrome after interventional therapy and to evaluate the long-term follow-up results.METHODS The clinical data and follow-up results of 60 patients with restenosis after interventional therapy from November 1983 to December 2013 were retrospectively analyzed.RESULTS Sixty patients with restenosis were retrospectively divided into a percutaneous transluminal angioplasty(PTA)group(40 patients)and a PTA+stent group(20 patients)according to the primary recanalization method.For the patients with restenosis in the PTA group,13 refused treatment,and 27 received further treatment;among these patients,five had a second restenosis,two had a third restenosis,and one had a fourth restenosis.For the patients with restenosis in the PTA+stent group,nine refused treatment,ten received PTA alone,and the other received PTA+stent implantation.Among the patients who received further treatment,five had a second restenosis,three had a third restenosis,and one had a fourth restenosis.The 1-,5-,10-,20-,and 25-year cumulative survival rates of the 38 patients who received further treatment after restenosis were 100%,78.3%,78.3%,70.5%,and 70.5%,respectively;however,for the 22 patients who refused treatment,the survival rates were 72.7%,45.9%,30.6%,10.2%,and unavailable,respectively(P<0.001).CONCLUSION Long-term follow-up after interventional therapy is very important.Active treatment for patients with restenosis can improve prognosis,and minimally invasive treatment strategies for restenosis allows to obtain satisfactory results.
基金funded by the Joint Research Fund in Astronomy under cooperative agreement between the National Natural Science Foundation of China (NSFC)the Chinese Academy of Sciences (Grant Nos. U1631239 and U1831115)+1 种基金the NSFC (Grant No. 11603008)the Fundamental Research Funds for Central Universities to Harbin Engineering University
文摘Transmission efficiency(TE) and focal ratio degradation(FRD) are two important parameters for evaluating the quality of an optical fiber system used for astronomy. Compared to TE, the focal ratio is more easily influenced by external factors, such as bending or stress. Optical cables are widely implemented for multi-object telescopes and integral field units(IFUs). The design and fabrication process of traditional optical cables seldom considers the requirements of astronomical applications. In this paper, we describe a fiber bundle structure as the basic unit for miniaturized high-density FASOT-IFU optical cables,instead of the micro-tube structure in stranded cables. Seven fibers with hexagonal arrangement were accurately positioned by ultraviolet(UV)-curing acrylate to form the bundle. The coating diameter of a fiber is0.125 mm, and the outer diameter of the bundle is 0.58 mm. Compared with the 0.8 mm micro-tube structure of a traditional stranded cable, the outer diameter of the fiber bundle was reduced by 27.5%. Fiber paste was filled into the bundle to reduce stress between the fibers. We tested the output focal ratio(OFR) in95% of the encircled energy(EE95) of the fibers in the bundle under different conditions. With the incident focal ratio F/8, the maximum difference of OFR is 0.6. In particular, when the incident focal ratio is F/5,the maximum difference of OFR is only 0.1. The jacket formed by the UV-curing acrylate can withstand a certain stress of less than 1.38 N mm-1. The fiber bundle can maintain uniform emitting characteristics with a bending radius of 7.5 cm and with tension less than 6 N. The test results show that the structure of the fiber bundle can be used as a basic unit for miniaturized high-density astronomical optical cables.
文摘Rice husk (biomass fuel) samples have been dried in drying oven and a series of drying curve for illustrating moisture migration of rice husk have been obtained. It is first research for rice husk drying,and it can provide reference of fuel processing for different boilers which require rice husk with various water contents. In this paper,we apply Page equation to reflect the drying process and obtain drying characteristic curve,then analyze the drying law. Kinetic analysis of the results of moisture migration test has been done,after which, effective moisture diffusion coefficient,activation energy and drying kinetic equation of rice husk samples are obtained in test temperature range (80 - 130 ℃) . And these results show specific influence law of temperature for effective moisture diffusion coefficient.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61605049 and 61575070the Natural Science Foundation of Fujian Province of China under Grant No 2018J01003+1 种基金the Fundamental Research Funds for the Central Universities under Grant No ZQN-707the Subsidized Project for Postgraduates’ Innovative Fund in Scientific Research of Huaqiao University
文摘A V-folded digital laser using a spatial light modulator(SLM)for intra-cavity loss shaping is exploited to generate Hermite-Gaussian modes with on-demand mode order.With aπ/2 astigmatic mode converter,vortex beams carrying on-demand orbital angular momentum(OAM)with a tunable range from-11h to 12 h are obtained.The mode order of the HG mode,hence the OAM of the vortex beam,is digitally switched by changing the phase pattern imposed on the SLM without requiring any mechanic alignment of the cavity.This work has great potential applications in various OAM-tunable vortex beams.
基金We thank the National Natural Science Foundation of China(No.52173264)for financial support。
文摘Carbonized metallic organic frameworks(CMOF)have been attracting attention in microwave absorption(MA)research area because of their diverse structures,tunable compositions,and rich porosity.Herein,structure regulation on metal clusters in CMOF is achieved by tuning the interaction strength between metals and ligands to enhance microwave absorption performance.Due to relatively weak interaction among copper cations and ligands,copper nanoclusters(CuNC)can be uniformly formed and embedded within the cobalt/zinc(Co/Zn)CMOF.Firstly,copper cations are added to the Co/Zn bimetallic zeolitic imidazolate frameworks(ZIFs).Secondly,the CMOF composite particles with CuNCs(CuNCs/CoZn-CMOF)were developed by a pyrolysis process.The CuNCs/CoZn-CMOF with an appropriate amount of CuNCs can harmonize both dielectric and magnetic losses.As a result,the minimum reflection loss(RLmin)reaches–45.1 dB at a matching thickness of 2.30 mm and the effective absorption bandwidth(EAB)is 8.80 GHz at a thickness of 3.10 mm.The broadband response to electromagnetic waves is attributed to interfacial polarization at CuNCs surface and heterogeneous interfaces,impedance matching and multiple scattering of electromagnetic waves.This study provides a feasible method to develop CMOF microwave absorption materials with high EAB values.
基金Natural Science Foundation of Tianjin City,Grant/Award Number:19JCYBJC17300National Natural Science Foundation of China,Grant/Award Numbers:21790052,51802220。
文摘Artificial synapses and neurons are crucial milestones for neuromorphic computing hardware,and memristors with resistive and threshold switching characteristics are regarded as the most promising candidates for the construction of hardware neural networks.However,most of the memristors can only operate in one mode,that is,resistive switching or threshold switching,and distinct memristors are required to construct fully memristive neuromorphic computing hardware,making it more complex for the fabrication and integration of the hardware.Herein,we propose a flexible dual-mode memristor array based on core–shell CsPbBr3@graphdiyne nanocrystals,which features a 100%transition yield,small cycle-to-cycle and device-to-device variability,excellent flexibility,and environmental stability.Based on this dual-mode memristor,homo-material-based fully memristive neuromorphic computing hardware—a power-free artificial nociceptive signal processing system and a spiking neural network—are constructed for the first time.Our dual-mode memristors greatly simplify the fabrication and integration of fully memristive neuromorphic systems.
基金This work was financially supported by the National Basic Research Program of China （Nos. 2016YFA0200103, 2013CB932603, 2012CB933404, and 2013CB934600）, the National Natural Science Foundation of China （Nos. 51520105003 and 51432002）, the Ministry of Education （No. 20120001130010）, and the Beijing Municipal Science and Technology Planning Project （No. Z151100003315013）.
基金finincially supported by the National Natural Science Foundation of China (Nos. 51373204 and 51873239)the National 973 Program of China (No. 2014CB643605)+3 种基金the Science and Technology Project of Guangdong Province (Nos. 2015B090915003 and 2015B090913003)the Leading Scientific, Technical and Innovation Talents of Guangdong Special Support Program (No. 2016TX03C295)the China Postdoctoral Science Foundation (No. 2017M612801)the Fundamental Research Funds of Sun Yat-sen University
文摘High-performance low-k and low-loss circuit materials are urgently needed in the field of microelectronics due to the upcoming FifthGeneration Mobile Communications Technology(5 G Technology).Herein,a facile design strategy for non-fluorinated intrinsic low-k and low-loss polyimides is reported by fully considering the secondary relaxation behaviors of the polymer chains.A new amorphous non-fluorinated polymer(TmBPPA)with a k value of 2.23 and a loss tangent lower than 3.94×10^-3 at 104 Hz has been designed and synthesized,which to the best of our knowledge is the lowest value amongst the non-fluorinated and non-porous polymers reported in literature.Meanwhile,TmBPPA exhibits excellent overall properties,such as excellent thermostability,good mechanical properties,low moisture absorption,and high bonding strength.As high-performance flexible circuit materials,all these characteristics are highly expected to meet the present and future demands for high density,high speed,and high frequency electronic circuit used in 5 G wireless networks.
基金This work was supported by the National Natural Science Foundation of China(Nos.21790052 and 51802220)Natural Science Foundation of Tianjin City(No.19JCYBJC17300).
文摘Graphdiyne(GDY)is emerging as a promising material for various applications owing to its unique structure and fascinating properties.However,the application of GDY in electronics and optoelectronics are still in its infancy,primarily owing to the huge challenge in the synthesis of large-area and uniform GDY film for scalable applications.Here a modified van der Waals epitaxy strategy is proposed to synthesize wafer-scale GDY film with high uniformity and controllable thickness directly on graphene(Gr)surface,providing an ideal platform to construct large-scale GDY/Gr-based optoelectronic synapse array.Essential synaptic behaviors have been realized,and the linear and symmetric conductance-update characteristics facilitate the implementation of neuromorphic computing for image recognition with high accuracy and strong fault tolerance.Logic functions including“NAND”and“NOR”are integrated into the synapse which can be executed in an optical pathway.Moreover,a visible information sensing-memory-processing system is constructed to execute real-time image acquisition,in situ image memorization and distinction tasks,avoiding the time latency and energy consumption caused by data conversion and transmission in conventional visual systems.These results highlight the potential of GDY in applications of neuromorphic computing and artificial visual systems.
基金supported by the National Basic Research Program of China (No.2016YFA0200103)the National Natural Science Foundation of China (Nos.51432002 and 51290272)the Beijing Municipal Science and Technology Planning Project (No.Z161100002116020).
文摘Direct growth of large area uniform graphene on functional insulating materials is essential for engineering versatile applications of graphene. However, the existing synthesis approaches can hardly avoid the generation of non-uniform multilayer graphene along the gas flow direction, affording huge challenges for further scaling up. Herein, by exploiting the molten state of soda-lime glass, we have accomplished the direct growth of large area uniform (up to 30 cm × 6 cm) graphene via a facile chemical vapor deposition route on low cost soda-lime glass. The use of molten glass eliminates the chemically active sites (surface corrugations, scratches, defects), and improves the mobility of carbon precursors, affording uniform nucleation and growth of monolayer graphene. Intriguingly, thus-obtained graphene acts as an ideal coating layer for the surface crystallographic modification of soda-lime glass, making it epitaxy substrates for synthesizing high-quality PbI2 nanoplates and continues films. Accordingly, a prototype photodetector was fabricated to present excellent photoelectrical properties of high responsivity (~ 600 on/off current ratio) and fast response speed (18 μs). This work hereby paves ways for the batch production and the direct applications of graphene glass as platforms for constructing high performance electronic and optoelectronic devices.
基金financially supported by the National Natural Science Foundation of China(No.52173264)the Natural Scienceof Chongqing(No.cstc2020jcyjmsxmX0401)。
文摘Herein, a low-cost, biodegradable, and high-performance microwave shielding graphite/starch material was fabricated via constructing a cation-π interaction between ammonium ions and graphite. The graphite flakes and starch were firstly mixed with distilled water containing ammonium hydroxide to form graphite/starch slurry under an ultrasonic assistant. The cation-π interaction could improve delamination degree and dispersion of graphite in starch matrix. The slurry was first used as a coating material on the surface of wood and paper to develop shielding packages. The effect of coating thickness and coating layers on EM shielding property of the materials was investigated. Second, the composites with a high orientation of graphite were fabricated by compression at high pressures. The electrical conductivity and EM shielding effectiveness(SET) of the materials were greatly enhanced by construction of cation-πinteraction and orientation of graphite. Specifically, the EM SETvalues increased from 56.9 to 66.8 d B for the composites with 50 wt.% graphite and 2.0 mm in thickness by constructing cation-π interaction. The EM SETvalues raised from 17.4 to 66.8 d B via the graphite orientation in the materials with the same components and thickness. The shielding mechanism of the compressed composites with orientation dispersion of graphite was also discussed in comparison to the coating layer with random dispersion of graphite.
基金the Natural Science Foundations of China(Nos.51573214,51233008)the Youth 1000 Talent Program of China
文摘Due to the remarkable electronic,optical,thermal,and mechanical properties,graphene-based materials have shown great potential in a wide range of technique applications.Particularly,the high transparency,conductivity,flexibility,and abundance make graphene materials highly attractive for polymer solar cells(PSCs).Graphene-based materials have been regarded as one promising candidate used in various parts in PSCs not only as electrodes,but also as interfacial layers and active layers with an aim to boost the power conversion efficiency of the devices.In this review,we summarize the recent progress about the design and synthesis of graphene-based materials for efficient PSCs along with the related challenges and future perspectives.
基金financially supported by the National Natural Science Foundation of China(No.51833011)the National Key Research and Development Program of China(No.2016YT03C077)。
文摘A novel method of patterning high precision copper conductive micropatterns on flexible polymer substrate(polyimide)is developed.We utilized the coordination effect between palladium salts and pyridine structures to fix the palladium chloride(PdCl_(2))on the surface of polymer film while the 2,6-dimethylpyridine structures formed in the specific areas under ultraviolet light guaranteed the resolution of final patterns.Simultaneous thermal reduction of PdCl_(2) on the surface can be achieved in the process of thermal cyclization of the polymer substrate.As a consequence,the obtained polyimide(PI)film can be patterned with conductive copper micropatterns directly by electroless plating.In particular,we accomplished the deposition of high precision copper pattern with a minimum line width of 50μm and minimum line spacing of 20μm on PI thin films(thickness~10μm)by electroless plating.The prepared conductive copper micropatterns exhibit a low resistivity of 1.78μΩ·cm the same as the pure block copper.And the relationship between the structures of the polymer chains and the physical properties of polymer substrates,such as the dimensional stability,mechanical and dielectric properties were also discussed in detail.This simple and novel method of patterning metal on the polymer surface does not need to achieve the catalytic metal adhesion required for electroless plating at the cost of destroying the substrate surface and avoiding the introduction of unstable interlayers.This patterning method is compatible with the current roll-to-roll production process and can be used to develop high-performance micro-integrated circuits.
