The longitudinal dispersion of the projectile in shooting tests of two-dimensional trajectory corrections fused with fixed canards is extremely large that it sometimes exceeds the correction ability of the correction ...The longitudinal dispersion of the projectile in shooting tests of two-dimensional trajectory corrections fused with fixed canards is extremely large that it sometimes exceeds the correction ability of the correction fuse actuator.The impact point easily deviates from the target,and thus the correction result cannot be readily evaluated.However,the cost of shooting tests is considerably high to conduct many tests for data collection.To address this issue,this study proposes an aiming method for shooting tests based on small sample size.The proposed method uses the Bootstrap method to expand the test data;repeatedly iterates and corrects the position of the simulated theoretical impact points through an improved compatibility test method;and dynamically adjusts the weight of the prior distribution of simulation results based on Kullback-Leibler divergence,which to some extent avoids the real data being"submerged"by the simulation data and achieves the fusion Bayesian estimation of the dispersion center.The experimental results show that when the simulation accuracy is sufficiently high,the proposed method yields a smaller mean-square deviation in estimating the dispersion center and higher shooting accuracy than those of the three comparison methods,which is more conducive to reflecting the effect of the control algorithm and facilitating test personnel to iterate their proposed structures and algorithms.;in addition,this study provides a knowledge base for further comprehensive studies in the future.展开更多
In the present work,Fe–Mn–Al–C powder mixtures were manufactured by elemental powders with different ball milling time,and the porous high-Mn and high-Al steel was fabricated by powder sintering.The results indicat...In the present work,Fe–Mn–Al–C powder mixtures were manufactured by elemental powders with different ball milling time,and the porous high-Mn and high-Al steel was fabricated by powder sintering.The results indicated that the powder size significantly decreased,and the morphology of the Fe powder tended to be increasingly flat as the milling time increased.However,the prolonged milling duration had limited impact on the phase transition of the powder mixture.The main phases of all the samples sintered at 640℃ were α-Fe,α-Mn and Al,and a small amount of Fe2Al5 and Al8Mn5.When the sintering temperature increased to 1200℃,the phase composition was mainly comprised of γ-Fe and α-Fe.The weight loss fraction of the sintered sample decreased with milling time,i.e.,8.3wt% after 20 h milling compared to15.3wt% for 10 h.The Mn depletion region(MDR) for the 10,15,and 20 h milled samples was about 780,600,and 370 μm,respectively.The total porosity of samples sintered at 640℃ decreased from ~46.6vol% for the 10 h milled powder to ~44.2vol% for 20 h milled powder.After sintering at 1200℃,the total porosity of sintered samples prepared by 10 and 20 h milled powder was ~58.3vol% and ~51.3vol%,respectively.The compressive strength and ductility of the 1200℃ sintered porous steel increased as the milling time increased.展开更多
Background: Percutaneous radiofrequency ablation(RFA) is a first?line treatment for very?early?stage hepatocellular carcinoma(HCC), whereas the efficacy of percutaneous microwave ablation(MWA) for very?early?stage HCC...Background: Percutaneous radiofrequency ablation(RFA) is a first?line treatment for very?early?stage hepatocellular carcinoma(HCC), whereas the efficacy of percutaneous microwave ablation(MWA) for very?early?stage HCC remains unclear. The purpose of this study was to clarify this issue by comparing the safety and efficacy of percutaneous MWA with percutaneous RFA in treating very?early?stage HCC.Methods: Clinical data of 460 patients who were diagnosed with very?early?stage HCC and treated with percutane?ous MWA or RFA between January 2007 and July 2012 at the Eastern Hepatobiliary Surgery Hospital, The Second Mili?tary Medical University, in Shanghai, China were retrospectively analyzed. Of these 460 patients, 159 received RFA, 301 received MWA. Overall survival(OS), recurrence?free survival(RFS), local tumor progression(LTP), complete ablation, and complication occurrence rates were compared between the two groups, and the prognostic factors associated with survival were analyzed.Results: No significant differences were observed between the two groups in terms of the 1?, 3?, or 5?year OS rates(99.3%, 90.4%, and 78.3% for MWA vs. 98.7%, 86.8%, and 73.3% for RFA, respectively; P = 0.331). Furthermore, no signif?icant differences were observed between the two groups in terms of the corresponding RFS rates(94.4%, 71.8%, and 46.9% for MWA vs. 89.9%, 67.3%, and 54.9% for RFA, respectively; P ete ablation rates(98.3% vs. 98.1%, P = 0.309), the LTP rates(9.6% vs. 10.1%, P = 0.883), the compl multivariate analysis, LTP, an= 0.860), or the occurrence rates of major complications(0.7% vs. 0.6%, P = 0.691). Bytiviral therapy, and treatment of recurrence were independent risk fac?tors for OS(P < 0.001), and the alpha?fetoprotein level was an independent prognostic factor for RFS(P = 0.002).Conclusions: MWA is as safe and effective as RFA in treating very?early?stage HCC, supporting MWA as a first?line treatment option for this disease.展开更多
Flexible,compact,lightweight and sustainable power sources are indispensable for modern wearable and personal electronics and small-unmanned aerial vehicles(UAVs).Hierarchical honeycomb has the unique merits of compac...Flexible,compact,lightweight and sustainable power sources are indispensable for modern wearable and personal electronics and small-unmanned aerial vehicles(UAVs).Hierarchical honeycomb has the unique merits of compact mesostructures,excellent energy absorption properties and considerable weight to strength ratios.Herein,a honeycomb-inspired triboelectric nanogenerator(h-TENG)is proposed for biomechanical and UAV morphing wing energy harvesting based on contact triboelectrification wavy surface of cellular honeycomb structure.The wavy surface comprises a multilayered thin film structure(combining polyethylene terephthalate,silver nanowires and fluorinated ethylene propylene)fabricated through high-temperature thermoplastic molding and wafer-level bonding process.With superior synchronization of large amounts of energy generation units with honeycomb cells,the manufactured h-TENG prototype produces the maximum instantaneous open-circuit voltage,short-circuit current and output power of 1207 V,68.5μA and 12.4 mW,respectively,corresponding to a remarkable peak power density of 0.275 mW cm^(−3)(or 2.48 mW g^(−1))under hand pressing excitations.Attributed to the excellent elastic property of self-rebounding honeycomb structure,the flexible and transparent h-TENG can be easily pressed,bent and integrated into shoes for real-time insole plantar pressure mapping.The lightweight and compact h-TENG is further installed into a morphing wing of small UAVs for efficiently converting the flapping energy of ailerons into electricity for the first time.This research demonstrates this new conceptualizing single h-TENG device’s versatility and viability for broad-range real-world application scenarios.展开更多
Collagen protein is an ideal scaffold material for the transplantation of neural stem cells.In this study,rat neural stem cells were seeded into a three-dimensional collagen gel scaffold,with suspension cultured neura...Collagen protein is an ideal scaffold material for the transplantation of neural stem cells.In this study,rat neural stem cells were seeded into a three-dimensional collagen gel scaffold,with suspension cultured neural stem cells being used as a control group.Neural stem cells,which were cultured in medium containing epidermal growth factor and basic fibroblast growth factor,actively expanded and formed neurospheres in both culture groups.In serum-free medium conditions,the processes extended from neurospheres in the collagen gel group were much longer than those in the suspension culture group.Immunofluorescence staining showed that neurospheres cultured in collagen gels were stained positive for nestin and differentiated cells were stained positive for the neuronal marker βIII-tubulin,the astrocytic marker glial fibrillary acidic protein and the oligodendrocytic marker 2',3'-cyclic nucleotide 3'-phosphodiesterase.Compared with neurospheres cultured in suspension,the differentiation potential of neural stem cells cultured in collagen gels increased,with the formation of neurons at an early stage.Our results show that the three-dimensional collagen gel culture system is superior to suspension culture in the proliferation,differentiation and process outgrowth of neural stem cells.展开更多
In adult mammals,axon regeneration after central nervous system injury is very poor,resulting in persistent functional loss.Enhancing the ability of axonal outgrowth may be a potential treatment strategy because matur...In adult mammals,axon regeneration after central nervous system injury is very poor,resulting in persistent functional loss.Enhancing the ability of axonal outgrowth may be a potential treatment strategy because mature neurons of the adult central nervous system may retain the intrinsic ability to regrow axons after injury.The protocadherin(Pcdh)clusters are thought to function in neuronal morphogenesis and in the assembly of neural circuitry in the brain.We cultured primary hippocampal neurons from E17.5 Pcdhαdeletion(del-α)mouse embryos.After culture for 1 day,axon length was obviously shorter in del-αneurons compared with wild-type neurons.RNA sequencing of hippocampal E17.5 RNA showed that expression levels of BDNF,Fmod,Nrp2,OGN,and Sema3d,which are associated with axon extension,were significantly down-regulated in the absence of the Pcdhαgene cluster.Using transmission electron microscopy,the ratio of myelinated nerve fibers in the axons of del-αhippocampal neurons was significantly decreased;myelin sheaths of P21 Pcdhα-del mice showed lamellar disorder,discrete appearance,and vacuoles.These results indicate that the Pcdhαcluster can promote the growth and myelination of axons in the neurodevelopmental stage.展开更多
BACKGROUND The guiding effect of prognostic stratification in multiple myeloma(MM) for treatment has been increasingly emphasized in recent years. The stratification of risk factors based on the International Staging ...BACKGROUND The guiding effect of prognostic stratification in multiple myeloma(MM) for treatment has been increasingly emphasized in recent years. The stratification of risk factors based on the International Staging System(ISS), Durie-Salmon(DS)staging and related indicators is affected by the renal function of patients,resulting in poor performance. This study assesses the relationship between interleukin-32(IL-32) and related risk factors in 67 patients with MM and their clinical outcomes.AIM To investigate the feasibility of IL-32 in evaluating prognosis in patients with MM and the factors influencing prognosis.METHODS This was a pragmatic, prospective observational study of patients with MM at a single center. According to IL-32 level, patients were divided into two groups.The variables under consideration included age, blood β2-microglobulin,albumin, C-reactive protein, serum calcium, serum creatinine, lactate dehydrogenase, M protein type, ISS stage, DS stage, and IL-32 levels and minimal residual disease(MRD) after induction treatment. The main outcomes were progression-free survival(PFS) and overall survival(OS).RESULTS IL-32 was an important factor affecting PFS and OS in patients with MM.Compared with patients with IL-32 levels ≥ 856.4 pg/m L, patients with IL-32 levels < 856.4 pg/m L had longer PFS(P = 0.0387) and OS(P = 0.0379);Univariate analysis showed that IL-32 level and MRD were significantly associated with OS and PFS(P < 0.05). Multivariate analysis showed that IL-32 levels ≥ 856.4 pg/m L and MRD positive were still independent risk factors for OS and PFS(P < 0.05).CONCLUSION IL-32 is valuable for assessing the prognosis of MM patients. IL-32 level combined with MRD may be a useful routine evaluation index for MM patients after treatment.展开更多
This study sought to assess the potential of brain-derived neurotrophic factor (BDNF) to promote neuronal repair and regeneration in rats with diffuse axonal injury, and to examine the accompanying neurobiological cha...This study sought to assess the potential of brain-derived neurotrophic factor (BDNF) to promote neuronal repair and regeneration in rats with diffuse axonal injury, and to examine the accompanying neurobiological changes. BDNF gene transfection reduced the severity of the pathological changes associated with diffuse axonal injury in cortical neurons of the frontal lobe and increased neurofilament protein expression. These findings demonstrate that BDNF can effectively promote neuronal repair and neurite regeneration after diffuse axonal injury.展开更多
GRACE-based estimates for groundwater storage(GWS)changes in North America substantially depend upon correction of glacialisostatic adjustment(GIA)effects,which are usually removed with GIA models.In this study,GIA ef...GRACE-based estimates for groundwater storage(GWS)changes in North America substantially depend upon correction of glacialisostatic adjustment(GIA)effects,which are usually removed with GIA models.In this study,GIA effects are eliminated by employing an independent separation approach with the aid of Global Navigation Satellite System(GNSS)vertical velocity data.Our goal is to provide an independent estimate for monthly GWS changes within North America in 1-degree-grids and their trends over the whole GRACE mission lifetime from April 2002 to June 2017.This estimate is derived from the release-6 version of GRACE monthly level-2 data,GNSS data,land surface models for soil moisture and snow wa-ter equivalent,and satellite altimetric lake leveldata.We find a GWS anomaly in form of an increasing trend in Saskatchewan,which affects the Saskatchewan Province and the states of Montana,North Dakota and Minnesota,and 4 GWS anomalies with declining trends in Nevada,California,Arizona and Texas,respec-tively.The monthly changes of these GWS anomalies,except for the one in Nevada,are validated by well level data.We provide results for average monthly GWS changes and the trends for the 5 anomalies but also in separate form for the 13 affected states or provinces.The increasing trends of the Saskatchewan GWS anomaly and the affected 3 states are related to increasing precipitation and can be elucidated by the decreasing drought intensity level.On the contrary,the declining trends in GWS can be explained by weakening precipitation and are mostly supported by the increasing drought intensity level in the other 4 anomalies and the affected states,which are Nevada,California,Arizona,New Mexico,Texas,Oklahoma,Kansas,and Colorado.Ourestimates of monthly GWS changes and their trendscan serveas alternativeand beneficial input for the sustainable management of groundwater resources in North America.展开更多
Electrochemical properties of lithium-sulfur(Li-S)batteries are mainly hindered by both the insulating nature of elemental sulfur(i.e.,molecular S8)and the shuttling effect or sluggish redox kinetics of lithium polysu...Electrochemical properties of lithium-sulfur(Li-S)batteries are mainly hindered by both the insulating nature of elemental sulfur(i.e.,molecular S8)and the shuttling effect or sluggish redox kinetics of lithium polysulfide intermediates(Li_(2)S_(n),3≤n≤8).In this paper,a three-dimensional mesoporous reduced graphene oxide-based nanocomposite,with the embedding of metallic Co nanoparticles and the doping of elemental N(Co/NrGO),and its simply ground mixture with powdered S at a mass ratio of 1:6(Co/NrGO/S)are prepared and used as cathode-/separator-coated interlayers and working electrodes in assembled Li-S cells,respectively.One of the effective cell configurations is to paste composite Co/NrGO onto both the S-loading cathode and separator,showing good cycling stability(1070mAh g^(−1) in the 100th cycle at 0.2 C),highrate capability(835mAh g^(−1),2.0 C),and excellent durability(905mAh g^(−1) in the 250th cycle at 0.5 or 0.2 C).Compared with the experimental results of Co-absent NrGO,electrochemical properties of various Co/NrGO-based cell configurations clearly show multiple functions of Co/NrGO,indicating that the absence of Co/NrGO coatings and/or Co nanoparticles may be inadequate to achieve superior S availability of assembled Li-S batteries.展开更多
Objective:to explore the development of drug counseling service,strengthen the quality of pharmacy service in outpatient pharmacy,better service to patients,promote harmonious relations between doctors and patients.Me...Objective:to explore the development of drug counseling service,strengthen the quality of pharmacy service in outpatient pharmacy,better service to patients,promote harmonious relations between doctors and patients.Methods:to analyze the necessity of drug consultation in outpatient pharmacy,in order to improve the quality of pharmacology service in outpatient pharmacy,we will discuss how to effectively provide drug counseling to improve the pharmacological service quality of outpatient pharmacy.Results:the implementation of the complete drug consultation process can effectively improve the quality of pharmaceutical work in outpatient pharmacy.Improve the patient's satisfaction with pharmaceutical work.Conclusion:with the perfection of the medical system,improving the quality of pharmaceutical service in outpatient service,and improving the quality of medical consultation,make it more systematic,normalization is important,only improving the quality of outpatient pharmacy service and strengthening the development of drug consultation work,to achieve the common progress of medical services.展开更多
Ultra-long,single crystal,Eu-doped α-Si3N4 nanowires were prepared by a simple approach involving nitriding Eu-doped cryomilled nanocrystalline Si powder in NH3 flow at 1350℃ for 4 h.Phases,chemical composition and ...Ultra-long,single crystal,Eu-doped α-Si3N4 nanowires were prepared by a simple approach involving nitriding Eu-doped cryomilled nanocrystalline Si powder in NH3 flow at 1350℃ for 4 h.Phases,chemical composition and microcosmic feature were tested by X-ray diffraction(XRD),field emission scanning electron microscopy(FESEM),transmission electron mi-展开更多
The steady-state fluorescence method has been tentatively used to determine the phase structures of microemulsion systems consisting of cetyltrimethylammonium bromide (CTAB), n-butanol (n-C4H9OH), octane (n-C8H18), an...The steady-state fluorescence method has been tentatively used to determine the phase structures of microemulsion systems consisting of cetyltrimethylammonium bromide (CTAB), n-butanol (n-C4H9OH), octane (n-C8H18), and water. The excimer/monomer intensity ratio (Ie/Im) of pyrene has demonstrated that the various structures in the microemulsion phase region can be distinguished. The results are consistent with electrical conductivity data already reported.展开更多
Nanoliposome is a useful dosage form to increase solubility and absorption of simvastatin(SMV), and consequently improves its therapeutic effects. However, in vivo toxicity of SMV could also be elevated accompanied by...Nanoliposome is a useful dosage form to increase solubility and absorption of simvastatin(SMV), and consequently improves its therapeutic effects. However, in vivo toxicity of SMV could also be elevated accompanied by the absorption enhancement, which is a decisive factor for the clinical application of SMV nanoliposome(SMV-Lipo), but has not been studied systematically and reported so far. In this study, organ toxicity of SMV-Lipo was evaluated in mice in the presence and absence of isoproterenol and compared to those of free SMV. Results demonstrated that compared to free SMV, the SMV-Lipo administrated at an equal dose of 25 mg/kg/d led to severe myocardiotoxicity, hepatotoxicity at baseline and more pronounced liver injury with elevation of alanine aminotransferase. In addition, muscular adverse effect was also observed in SMV-Lipo treated group but not in SMV group. Pharmacokinetic studies revealed that compared to free SMV, the SMV-Lipo administration significantly improved the plasma SMV concentration, and the oral bioavailability was 6.5 times of free SMV. Notably, when the dosage of free SMV increased to 50 mg/kg/d, yielding the comparable plasma concentration as SMV-Lipo given at 25 mg/kg/d, the myocardiotoxicity was observed in free SMV treated mice as well, which further confirmed that the enhanced absorption of SMV by the nanoliposomal formulation resulted in more severe myocardiotoxicity than the equal dose of free SMV.展开更多
Mechanical metamaterials can be defined as a class of architected materials that exhibit unprecedented mechanical properties derived from designed artificial architectures rather than their constituent materials.While...Mechanical metamaterials can be defined as a class of architected materials that exhibit unprecedented mechanical properties derived from designed artificial architectures rather than their constituent materials.While macroscale and simple layouts can be realized by conventional top-down manufacturing approaches,many of the sophisticated designs at various length scales remain elusive,due to the lack of adequate manufacturing methods.Recent progress in additive manufacturing(AM)has led to the realization of a myriad of novel metamaterial concepts.AM methods capable of fabricating microscale architectures with high resolution,arbitrary complexity,and high feature fidelity have enabled the rapid development of architected meta materials and drastically reduced the design-computation and experimental-validation cycle.This paper first provides a detailed review of various topologies based on the desired mechanical properties,including stiff,strong,and auxetic(negative Poisson’s ratio)metamaterials,followed by a discussion of the AM technologies capable of fabricating these metamaterials.Finally,we discuss current challenges and recommend future directions for AM and mechanical metamaterials.展开更多
The lytropic liquid crystals in dodecanic acid diethanolamine (DAD) /n-butanol (C4OH) /octane (n-C8H18) /deuteron (D2O) system were studied to determine the phase regions and were investigated by 2H-NMR spectroscopy,o...The lytropic liquid crystals in dodecanic acid diethanolamine (DAD) /n-butanol (C4OH) /octane (n-C8H18) /deuteron (D2O) system were studied to determine the phase regions and were investigated by 2H-NMR spectroscopy,optical polarizing microscope and small-angle X-ray diffraction (SAXD) methods.The results indicate that the lamellar,hexagonal and cubic liquid crystals all exist in the above system.Keeping the weight ratio of DAD and C4OH constant,the microphase Structure,2H quadruple splitting and the interlayer spacing are all changed with the addition of deuteron.展开更多
In order to design and verify control algorithms for flapping wing aerial vehicles(FWAVs),calculation models of the translational force,rotational force and virtual mass force were established with the basis on the mo...In order to design and verify control algorithms for flapping wing aerial vehicles(FWAVs),calculation models of the translational force,rotational force and virtual mass force were established with the basis on the modified quasi-steady aerodynamic theory and high lift mechanisms of insect flight.The simulation results show that the rotational force and virtual mass force can be ignored in the hovering FWAVs with simple harmonic motions in a cycle.The effects of the wing deformation on aerodynamic forces were investigated by regarding the maximum rotational angle of wingtip as a reference variable.The simulation results also show that the average lift coefficient increases and drag coefficient decreases with the increase of the maximum rotational angle of wingtip in the range of 0-90°.展开更多
Spinal cord injury(SCI) is a severe trauma to the central nervous system(CNS). This article reviews recent advances in cellular transplantation to treat SCI. Transplanted cells can supply new neurons to replace injure...Spinal cord injury(SCI) is a severe trauma to the central nervous system(CNS). This article reviews recent advances in cellular transplantation to treat SCI. Transplanted cells can supply new neurons to replace injured ones,promote regeneration of axons and myelin sheath,modulate the inflammatory response,and thus promote recovery from traumatic injury of the CNS. Cellular transplantation is a promising potential method for the treatment of SCI.展开更多
Cervical arthroplasty after anterior decompression with insertion of a prosthetic total disc replacement has been suggested as an alternate to anterior cervical fusion. It develops quickly during recent years. Current...Cervical arthroplasty after anterior decompression with insertion of a prosthetic total disc replacement has been suggested as an alternate to anterior cervical fusion. It develops quickly during recent years. Currently there are several cervical arthroplasty devices. Each device varies in terms of materials, range of motion and constraint. Early studies suggest that in the short term, the complication rate and efficacy is no worse than fusion surgery. Long-term results have not yet been reported. This review examines the current prostheses as well as discussing issues regarding indications and technique. It is hoped that an improvement of cervical arthroplasty occurs in terms of materials and design as spinal surgeons enter a new times of the management of cervical spine disease.展开更多
The W-Cu composites are widely used as weld-ing electrodes,electronic packaging materials,electric discharge materials and heat sinks becauseof the excellent properties.In this research,theW-40wt.%Cu composites were p...The W-Cu composites are widely used as weld-ing electrodes,electronic packaging materials,electric discharge materials and heat sinks becauseof the excellent properties.In this research,theW-40wt.%Cu composites were prepared through thevacuum hot-press sintering method,and the effectof sintering temperature on the microstructure展开更多
基金the National Natural Science Foundation of China(Grant No.61973033)Preliminary Research of Equipment(Grant No.9090102010305)for funding the experiments。
文摘The longitudinal dispersion of the projectile in shooting tests of two-dimensional trajectory corrections fused with fixed canards is extremely large that it sometimes exceeds the correction ability of the correction fuse actuator.The impact point easily deviates from the target,and thus the correction result cannot be readily evaluated.However,the cost of shooting tests is considerably high to conduct many tests for data collection.To address this issue,this study proposes an aiming method for shooting tests based on small sample size.The proposed method uses the Bootstrap method to expand the test data;repeatedly iterates and corrects the position of the simulated theoretical impact points through an improved compatibility test method;and dynamically adjusts the weight of the prior distribution of simulation results based on Kullback-Leibler divergence,which to some extent avoids the real data being"submerged"by the simulation data and achieves the fusion Bayesian estimation of the dispersion center.The experimental results show that when the simulation accuracy is sufficiently high,the proposed method yields a smaller mean-square deviation in estimating the dispersion center and higher shooting accuracy than those of the three comparison methods,which is more conducive to reflecting the effect of the control algorithm and facilitating test personnel to iterate their proposed structures and algorithms.;in addition,this study provides a knowledge base for further comprehensive studies in the future.
基金financially supported by the National Key R&D Program of China(No.2021YFB3802300)the National Natural Science Foundation of China(No.51804239)Guangdong Major Project of Basic and Applied Basic Research,China(No.2021B0301030001)。
文摘In the present work,Fe–Mn–Al–C powder mixtures were manufactured by elemental powders with different ball milling time,and the porous high-Mn and high-Al steel was fabricated by powder sintering.The results indicated that the powder size significantly decreased,and the morphology of the Fe powder tended to be increasingly flat as the milling time increased.However,the prolonged milling duration had limited impact on the phase transition of the powder mixture.The main phases of all the samples sintered at 640℃ were α-Fe,α-Mn and Al,and a small amount of Fe2Al5 and Al8Mn5.When the sintering temperature increased to 1200℃,the phase composition was mainly comprised of γ-Fe and α-Fe.The weight loss fraction of the sintered sample decreased with milling time,i.e.,8.3wt% after 20 h milling compared to15.3wt% for 10 h.The Mn depletion region(MDR) for the 10,15,and 20 h milled samples was about 780,600,and 370 μm,respectively.The total porosity of samples sintered at 640℃ decreased from ~46.6vol% for the 10 h milled powder to ~44.2vol% for 20 h milled powder.After sintering at 1200℃,the total porosity of sintered samples prepared by 10 and 20 h milled powder was ~58.3vol% and ~51.3vol%,respectively.The compressive strength and ductility of the 1200℃ sintered porous steel increased as the milling time increased.
文摘Background: Percutaneous radiofrequency ablation(RFA) is a first?line treatment for very?early?stage hepatocellular carcinoma(HCC), whereas the efficacy of percutaneous microwave ablation(MWA) for very?early?stage HCC remains unclear. The purpose of this study was to clarify this issue by comparing the safety and efficacy of percutaneous MWA with percutaneous RFA in treating very?early?stage HCC.Methods: Clinical data of 460 patients who were diagnosed with very?early?stage HCC and treated with percutane?ous MWA or RFA between January 2007 and July 2012 at the Eastern Hepatobiliary Surgery Hospital, The Second Mili?tary Medical University, in Shanghai, China were retrospectively analyzed. Of these 460 patients, 159 received RFA, 301 received MWA. Overall survival(OS), recurrence?free survival(RFS), local tumor progression(LTP), complete ablation, and complication occurrence rates were compared between the two groups, and the prognostic factors associated with survival were analyzed.Results: No significant differences were observed between the two groups in terms of the 1?, 3?, or 5?year OS rates(99.3%, 90.4%, and 78.3% for MWA vs. 98.7%, 86.8%, and 73.3% for RFA, respectively; P = 0.331). Furthermore, no signif?icant differences were observed between the two groups in terms of the corresponding RFS rates(94.4%, 71.8%, and 46.9% for MWA vs. 89.9%, 67.3%, and 54.9% for RFA, respectively; P ete ablation rates(98.3% vs. 98.1%, P = 0.309), the LTP rates(9.6% vs. 10.1%, P = 0.883), the compl multivariate analysis, LTP, an= 0.860), or the occurrence rates of major complications(0.7% vs. 0.6%, P = 0.691). Bytiviral therapy, and treatment of recurrence were independent risk fac?tors for OS(P < 0.001), and the alpha?fetoprotein level was an independent prognostic factor for RFS(P = 0.002).Conclusions: MWA is as safe and effective as RFA in treating very?early?stage HCC, supporting MWA as a first?line treatment option for this disease.
基金This research is supported by the National Natural Science Foundation of China Grant(Nos.51705429&61801525)the Fundamental Research Funds for the Central Universities,Guangdong Natural Science Funds Grant(2018A030313400)+1 种基金Space Science and Technology Foundation,111 Project No.B13044UK Engineering and Physical Sciences Research Council(EPSRC)for support under grant EP/P018998/1,Newton Mobility Grant(IE161019)through Royal Society.
文摘Flexible,compact,lightweight and sustainable power sources are indispensable for modern wearable and personal electronics and small-unmanned aerial vehicles(UAVs).Hierarchical honeycomb has the unique merits of compact mesostructures,excellent energy absorption properties and considerable weight to strength ratios.Herein,a honeycomb-inspired triboelectric nanogenerator(h-TENG)is proposed for biomechanical and UAV morphing wing energy harvesting based on contact triboelectrification wavy surface of cellular honeycomb structure.The wavy surface comprises a multilayered thin film structure(combining polyethylene terephthalate,silver nanowires and fluorinated ethylene propylene)fabricated through high-temperature thermoplastic molding and wafer-level bonding process.With superior synchronization of large amounts of energy generation units with honeycomb cells,the manufactured h-TENG prototype produces the maximum instantaneous open-circuit voltage,short-circuit current and output power of 1207 V,68.5μA and 12.4 mW,respectively,corresponding to a remarkable peak power density of 0.275 mW cm^(−3)(or 2.48 mW g^(−1))under hand pressing excitations.Attributed to the excellent elastic property of self-rebounding honeycomb structure,the flexible and transparent h-TENG can be easily pressed,bent and integrated into shoes for real-time insole plantar pressure mapping.The lightweight and compact h-TENG is further installed into a morphing wing of small UAVs for efficiently converting the flapping energy of ailerons into electricity for the first time.This research demonstrates this new conceptualizing single h-TENG device’s versatility and viability for broad-range real-world application scenarios.
文摘Collagen protein is an ideal scaffold material for the transplantation of neural stem cells.In this study,rat neural stem cells were seeded into a three-dimensional collagen gel scaffold,with suspension cultured neural stem cells being used as a control group.Neural stem cells,which were cultured in medium containing epidermal growth factor and basic fibroblast growth factor,actively expanded and formed neurospheres in both culture groups.In serum-free medium conditions,the processes extended from neurospheres in the collagen gel group were much longer than those in the suspension culture group.Immunofluorescence staining showed that neurospheres cultured in collagen gels were stained positive for nestin and differentiated cells were stained positive for the neuronal marker βIII-tubulin,the astrocytic marker glial fibrillary acidic protein and the oligodendrocytic marker 2',3'-cyclic nucleotide 3'-phosphodiesterase.Compared with neurospheres cultured in suspension,the differentiation potential of neural stem cells cultured in collagen gels increased,with the formation of neurons at an early stage.Our results show that the three-dimensional collagen gel culture system is superior to suspension culture in the proliferation,differentiation and process outgrowth of neural stem cells.
基金supported by a grant from the Science and Technology Commission of Shanghai Municipality of China,No.12441900702
文摘In adult mammals,axon regeneration after central nervous system injury is very poor,resulting in persistent functional loss.Enhancing the ability of axonal outgrowth may be a potential treatment strategy because mature neurons of the adult central nervous system may retain the intrinsic ability to regrow axons after injury.The protocadherin(Pcdh)clusters are thought to function in neuronal morphogenesis and in the assembly of neural circuitry in the brain.We cultured primary hippocampal neurons from E17.5 Pcdhαdeletion(del-α)mouse embryos.After culture for 1 day,axon length was obviously shorter in del-αneurons compared with wild-type neurons.RNA sequencing of hippocampal E17.5 RNA showed that expression levels of BDNF,Fmod,Nrp2,OGN,and Sema3d,which are associated with axon extension,were significantly down-regulated in the absence of the Pcdhαgene cluster.Using transmission electron microscopy,the ratio of myelinated nerve fibers in the axons of del-αhippocampal neurons was significantly decreased;myelin sheaths of P21 Pcdhα-del mice showed lamellar disorder,discrete appearance,and vacuoles.These results indicate that the Pcdhαcluster can promote the growth and myelination of axons in the neurodevelopmental stage.
基金Supported by Foundation for Excellent Young Medical Talents from the Quzhou People’s Hospital
文摘BACKGROUND The guiding effect of prognostic stratification in multiple myeloma(MM) for treatment has been increasingly emphasized in recent years. The stratification of risk factors based on the International Staging System(ISS), Durie-Salmon(DS)staging and related indicators is affected by the renal function of patients,resulting in poor performance. This study assesses the relationship between interleukin-32(IL-32) and related risk factors in 67 patients with MM and their clinical outcomes.AIM To investigate the feasibility of IL-32 in evaluating prognosis in patients with MM and the factors influencing prognosis.METHODS This was a pragmatic, prospective observational study of patients with MM at a single center. According to IL-32 level, patients were divided into two groups.The variables under consideration included age, blood β2-microglobulin,albumin, C-reactive protein, serum calcium, serum creatinine, lactate dehydrogenase, M protein type, ISS stage, DS stage, and IL-32 levels and minimal residual disease(MRD) after induction treatment. The main outcomes were progression-free survival(PFS) and overall survival(OS).RESULTS IL-32 was an important factor affecting PFS and OS in patients with MM.Compared with patients with IL-32 levels ≥ 856.4 pg/m L, patients with IL-32 levels < 856.4 pg/m L had longer PFS(P = 0.0387) and OS(P = 0.0379);Univariate analysis showed that IL-32 level and MRD were significantly associated with OS and PFS(P < 0.05). Multivariate analysis showed that IL-32 levels ≥ 856.4 pg/m L and MRD positive were still independent risk factors for OS and PFS(P < 0.05).CONCLUSION IL-32 is valuable for assessing the prognosis of MM patients. IL-32 level combined with MRD may be a useful routine evaluation index for MM patients after treatment.
基金the National Natural Science Foundation of China (Key Program and General Program), No. 10832012 10872078
文摘This study sought to assess the potential of brain-derived neurotrophic factor (BDNF) to promote neuronal repair and regeneration in rats with diffuse axonal injury, and to examine the accompanying neurobiological changes. BDNF gene transfection reduced the severity of the pathological changes associated with diffuse axonal injury in cortical neurons of the frontal lobe and increased neurofilament protein expression. These findings demonstrate that BDNF can effectively promote neuronal repair and neurite regeneration after diffuse axonal injury.
基金This work is funded by the National Key R&D Program of China(2017YFA0603103)the National Natural Science Foundation of China(41974009 and 42004007)+1 种基金Key Research Program of Frontier Sciences,CAS(QYZDB-SSW-DQC042 and QYZDJ-SSW-DQC027)Alberta Innovates(the Groundwater Recharge in the Prairies project)。
文摘GRACE-based estimates for groundwater storage(GWS)changes in North America substantially depend upon correction of glacialisostatic adjustment(GIA)effects,which are usually removed with GIA models.In this study,GIA effects are eliminated by employing an independent separation approach with the aid of Global Navigation Satellite System(GNSS)vertical velocity data.Our goal is to provide an independent estimate for monthly GWS changes within North America in 1-degree-grids and their trends over the whole GRACE mission lifetime from April 2002 to June 2017.This estimate is derived from the release-6 version of GRACE monthly level-2 data,GNSS data,land surface models for soil moisture and snow wa-ter equivalent,and satellite altimetric lake leveldata.We find a GWS anomaly in form of an increasing trend in Saskatchewan,which affects the Saskatchewan Province and the states of Montana,North Dakota and Minnesota,and 4 GWS anomalies with declining trends in Nevada,California,Arizona and Texas,respec-tively.The monthly changes of these GWS anomalies,except for the one in Nevada,are validated by well level data.We provide results for average monthly GWS changes and the trends for the 5 anomalies but also in separate form for the 13 affected states or provinces.The increasing trends of the Saskatchewan GWS anomaly and the affected 3 states are related to increasing precipitation and can be elucidated by the decreasing drought intensity level.On the contrary,the declining trends in GWS can be explained by weakening precipitation and are mostly supported by the increasing drought intensity level in the other 4 anomalies and the affected states,which are Nevada,California,Arizona,New Mexico,Texas,Oklahoma,Kansas,and Colorado.Ourestimates of monthly GWS changes and their trendscan serveas alternativeand beneficial input for the sustainable management of groundwater resources in North America.
基金The authors are grateful for the financial support of the National Natural Science Foundation of China(21673131)the Natural Science Foundation of Fujian Province(2019J01800).
文摘Electrochemical properties of lithium-sulfur(Li-S)batteries are mainly hindered by both the insulating nature of elemental sulfur(i.e.,molecular S8)and the shuttling effect or sluggish redox kinetics of lithium polysulfide intermediates(Li_(2)S_(n),3≤n≤8).In this paper,a three-dimensional mesoporous reduced graphene oxide-based nanocomposite,with the embedding of metallic Co nanoparticles and the doping of elemental N(Co/NrGO),and its simply ground mixture with powdered S at a mass ratio of 1:6(Co/NrGO/S)are prepared and used as cathode-/separator-coated interlayers and working electrodes in assembled Li-S cells,respectively.One of the effective cell configurations is to paste composite Co/NrGO onto both the S-loading cathode and separator,showing good cycling stability(1070mAh g^(−1) in the 100th cycle at 0.2 C),highrate capability(835mAh g^(−1),2.0 C),and excellent durability(905mAh g^(−1) in the 250th cycle at 0.5 or 0.2 C).Compared with the experimental results of Co-absent NrGO,electrochemical properties of various Co/NrGO-based cell configurations clearly show multiple functions of Co/NrGO,indicating that the absence of Co/NrGO coatings and/or Co nanoparticles may be inadequate to achieve superior S availability of assembled Li-S batteries.
文摘Objective:to explore the development of drug counseling service,strengthen the quality of pharmacy service in outpatient pharmacy,better service to patients,promote harmonious relations between doctors and patients.Methods:to analyze the necessity of drug consultation in outpatient pharmacy,in order to improve the quality of pharmacology service in outpatient pharmacy,we will discuss how to effectively provide drug counseling to improve the pharmacological service quality of outpatient pharmacy.Results:the implementation of the complete drug consultation process can effectively improve the quality of pharmaceutical work in outpatient pharmacy.Improve the patient's satisfaction with pharmaceutical work.Conclusion:with the perfection of the medical system,improving the quality of pharmaceutical service in outpatient service,and improving the quality of medical consultation,make it more systematic,normalization is important,only improving the quality of outpatient pharmacy service and strengthening the development of drug consultation work,to achieve the common progress of medical services.
文摘Ultra-long,single crystal,Eu-doped α-Si3N4 nanowires were prepared by a simple approach involving nitriding Eu-doped cryomilled nanocrystalline Si powder in NH3 flow at 1350℃ for 4 h.Phases,chemical composition and microcosmic feature were tested by X-ray diffraction(XRD),field emission scanning electron microscopy(FESEM),transmission electron mi-
基金the Science Foundation of Shandong University for the Youth (y34029) and the National Natural Science Foundation of China (29903006).
文摘The steady-state fluorescence method has been tentatively used to determine the phase structures of microemulsion systems consisting of cetyltrimethylammonium bromide (CTAB), n-butanol (n-C4H9OH), octane (n-C8H18), and water. The excimer/monomer intensity ratio (Ie/Im) of pyrene has demonstrated that the various structures in the microemulsion phase region can be distinguished. The results are consistent with electrical conductivity data already reported.
基金This work was supported by grants from the National Natural Science Foundation of China(No.81770268)the National Basic Research Program of China(No.2015CB932100).
文摘Nanoliposome is a useful dosage form to increase solubility and absorption of simvastatin(SMV), and consequently improves its therapeutic effects. However, in vivo toxicity of SMV could also be elevated accompanied by the absorption enhancement, which is a decisive factor for the clinical application of SMV nanoliposome(SMV-Lipo), but has not been studied systematically and reported so far. In this study, organ toxicity of SMV-Lipo was evaluated in mice in the presence and absence of isoproterenol and compared to those of free SMV. Results demonstrated that compared to free SMV, the SMV-Lipo administrated at an equal dose of 25 mg/kg/d led to severe myocardiotoxicity, hepatotoxicity at baseline and more pronounced liver injury with elevation of alanine aminotransferase. In addition, muscular adverse effect was also observed in SMV-Lipo treated group but not in SMV group. Pharmacokinetic studies revealed that compared to free SMV, the SMV-Lipo administration significantly improved the plasma SMV concentration, and the oral bioavailability was 6.5 times of free SMV. Notably, when the dosage of free SMV increased to 50 mg/kg/d, yielding the comparable plasma concentration as SMV-Lipo given at 25 mg/kg/d, the myocardiotoxicity was observed in free SMV treated mice as well, which further confirmed that the enhanced absorption of SMV by the nanoliposomal formulation resulted in more severe myocardiotoxicity than the equal dose of free SMV.
基金supported by the Guangdong Major Project of Basic and Applied Basic Research(2021B0301030001)project supported by the Space Utilization System of China Manned Space Engineering(KJZ-YY-WCL03)+6 种基金National Key Laboratory Foundation of Science and Technology on Materials under Shock and Impact(6142902210109)National Key Research and Development Program of China(2018YFB0905600 and 2017YFB0310400)National Natural Science Foundation of China(51472188 and 51521001)Natural Research Funds of Hubei Province(2016CFB583)Natural Research Funds of Shenzhen,Fundamental Research Funds for the Central Universities China,State Key Laboratory of Advanced Electromagnetic Engineering and Technology(Huazhong University of Science and Technology)the Science and Technology Project of the Global Energy Interconnection Research Institute Co.,Ltd.(SGGR0000WLJS1801080)the 111 Project(B13035)。
文摘Mechanical metamaterials can be defined as a class of architected materials that exhibit unprecedented mechanical properties derived from designed artificial architectures rather than their constituent materials.While macroscale and simple layouts can be realized by conventional top-down manufacturing approaches,many of the sophisticated designs at various length scales remain elusive,due to the lack of adequate manufacturing methods.Recent progress in additive manufacturing(AM)has led to the realization of a myriad of novel metamaterial concepts.AM methods capable of fabricating microscale architectures with high resolution,arbitrary complexity,and high feature fidelity have enabled the rapid development of architected meta materials and drastically reduced the design-computation and experimental-validation cycle.This paper first provides a detailed review of various topologies based on the desired mechanical properties,including stiff,strong,and auxetic(negative Poisson’s ratio)metamaterials,followed by a discussion of the AM technologies capable of fabricating these metamaterials.Finally,we discuss current challenges and recommend future directions for AM and mechanical metamaterials.
文摘The lytropic liquid crystals in dodecanic acid diethanolamine (DAD) /n-butanol (C4OH) /octane (n-C8H18) /deuteron (D2O) system were studied to determine the phase regions and were investigated by 2H-NMR spectroscopy,optical polarizing microscope and small-angle X-ray diffraction (SAXD) methods.The results indicate that the lamellar,hexagonal and cubic liquid crystals all exist in the above system.Keeping the weight ratio of DAD and C4OH constant,the microphase Structure,2H quadruple splitting and the interlayer spacing are all changed with the addition of deuteron.
基金National Natural Science Foundation of China(5177041109)。
文摘In order to design and verify control algorithms for flapping wing aerial vehicles(FWAVs),calculation models of the translational force,rotational force and virtual mass force were established with the basis on the modified quasi-steady aerodynamic theory and high lift mechanisms of insect flight.The simulation results show that the rotational force and virtual mass force can be ignored in the hovering FWAVs with simple harmonic motions in a cycle.The effects of the wing deformation on aerodynamic forces were investigated by regarding the maximum rotational angle of wingtip as a reference variable.The simulation results also show that the average lift coefficient increases and drag coefficient decreases with the increase of the maximum rotational angle of wingtip in the range of 0-90°.
基金supported by Shanghai Science and Technology Development Foundation(054119558)
文摘Spinal cord injury(SCI) is a severe trauma to the central nervous system(CNS). This article reviews recent advances in cellular transplantation to treat SCI. Transplanted cells can supply new neurons to replace injured ones,promote regeneration of axons and myelin sheath,modulate the inflammatory response,and thus promote recovery from traumatic injury of the CNS. Cellular transplantation is a promising potential method for the treatment of SCI.
文摘Cervical arthroplasty after anterior decompression with insertion of a prosthetic total disc replacement has been suggested as an alternate to anterior cervical fusion. It develops quickly during recent years. Currently there are several cervical arthroplasty devices. Each device varies in terms of materials, range of motion and constraint. Early studies suggest that in the short term, the complication rate and efficacy is no worse than fusion surgery. Long-term results have not yet been reported. This review examines the current prostheses as well as discussing issues regarding indications and technique. It is hoped that an improvement of cervical arthroplasty occurs in terms of materials and design as spinal surgeons enter a new times of the management of cervical spine disease.
文摘The W-Cu composites are widely used as weld-ing electrodes,electronic packaging materials,electric discharge materials and heat sinks becauseof the excellent properties.In this research,theW-40wt.%Cu composites were prepared through thevacuum hot-press sintering method,and the effectof sintering temperature on the microstructure
