Dysosma versipellis is the rhizome of Bajiaolian in Berberaceae.It is a unique medicinal plant in China and it was the first to be recorded in Shennong’s Classic of Materia Medica(unknown author,25–220 C.E.).It has ...Dysosma versipellis is the rhizome of Bajiaolian in Berberaceae.It is a unique medicinal plant in China and it was the first to be recorded in Shennong’s Classic of Materia Medica(unknown author,25–220 C.E.).It has complex chemical components as well as complex,pharmacological and toxicological effects are extensive.Based on the recent research progress,the chemical constituents,pharmacological activities and toxicological effects of Dysosma versipellis were summarized.Combined with the core concept of quality markers of traditional Chinese medicine,the prediction and analysis were carried out from the aspects of phytogenetics and the source pathway of specific chemical constituents,traditional medicinal properties,traditional efficacy,chemical composition measurability,blood components,and pharmacokinetics,in order to provide reference for further study of Dysosma versipellis.展开更多
Vagus nerve stimulation exerts protective effects against ischemic brain injury; however, the underlying mechanisms remain unclear. In this study, a rat model of focal cerebral ischemia was established using the occlu...Vagus nerve stimulation exerts protective effects against ischemic brain injury; however, the underlying mechanisms remain unclear. In this study, a rat model of focal cerebral ischemia was established using the occlusion method, and the right vagus nerve was given electrical stimula-tion (constant current of 0.5 mA; pulse width, 0.5 ms; frequency, 20 Hz; duration, 30 seconds; every 5 minutes for a total of 60 minutes) 30 minutes, 12 hours, and 1, 2, 3, 7 and 14 days after surgery. Electrical stimulation of the vagus nerve substantially reduced infarct volume, improved neurological function, and decreased the expression levels of tumor necrosis factor-α and in-terleukin-6 in rats with focal cerebral ischemia. The experimental findings indicate that the neuroprotective effect of vagus nerve stimulation following cerebral ischemia may be associated with the inhibition of tumor necrosis factor-α and interleukin-6 expression.展开更多
Here in this paper,we report a room-temperature operating infrared photodetector based on the interband transition of an In As Sb/Ga Sb quantum well.The interband transition energy of 5-nm thick In As(0.91)Sb(0.09...Here in this paper,we report a room-temperature operating infrared photodetector based on the interband transition of an In As Sb/Ga Sb quantum well.The interband transition energy of 5-nm thick In As(0.91)Sb(0.09) embedded in the Ga Sb barrier is calculated to be 0.53 e V(2.35μm),which makes the absorption range of In As Sb cover an entire range from short-wavelength infrared to long-wavelength infrared spectrum.The fabricated photodetector exhibits a narrow response range from 2.0μm to 2.3μm with a peak around 2.1μm at 300 K.The peak responsivity is 0.4 A/W under-500-m Vapplied bias voltage,corresponding to a peak quantum efficiency of 23.8%in the case without any anti-reflection coating.At 300 K,the photodetector exhibits a dark current density of 6.05×10^-3A/cm^2 under-400-m V applied bias voltage and 3.25×10^-5A/cm^2 under zero,separately.The peak detectivity is 6.91×10^10cm·Hz^1/2/W under zero bias voltage at 300 K.展开更多
BACKGROUND Dipeptidyl peptidase-4(DPP4)is commonly targeted to achieve glycemic control and has potent anti-inflammatory and immunoregulatory effects.Recent structural analyses indicated a potential tight interaction ...BACKGROUND Dipeptidyl peptidase-4(DPP4)is commonly targeted to achieve glycemic control and has potent anti-inflammatory and immunoregulatory effects.Recent structural analyses indicated a potential tight interaction between DPP4 and severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),raising a promising hypothesis that DPP4 inhibitor(DPP4i)drugs might be an optimal strategy for treating coronavirus disease 2019(COVID-19)among patients with diabetes.However,there has been no direct clinical evidence illuminating the associations between DPP4i use and COVID-19 outcomes.AIM To illuminate the associations between DPP4i usage and the adverse outcomes of COVID-19.METHODS We conducted a multicenter,retrospective analysis including 2563 patients with type 2 diabetes who were hospitalized due to COVID-19 at 16 hospitals in Hubei Province,China.After excluding ineligible individuals,142 patients who received DPP4i drugs and 1115 patients who received non-DPP4i oral anti-diabetic drugs were included in the subsequent analysis.We performed a strict propensity score matching(PSM)analysis where age,sex,comorbidities,number of oral hypoglycemic agents,heart rate,blood pressure,pulse oxygen saturation(SpO2)<95%,CT diagnosed bilateral lung lesions,laboratory indicators,and proportion of insulin usage were matched.Finally,111 participants treated with DPP4i drugs were successfully matched to 333 non-DPP4i users.Then,a linear logistic model and mixed-effect Cox model were applied to analyze the associations between inhospital DPP4i use and adverse outcomes of COVID-19.RESULTS After rigorous matching and further adjustments for imbalanced variables in the linear logistic model and Cox adjusted model,we found that there was no significant association between in-hospital DPP4i use(DPP4i group)and 28-d allcause mortality(adjusted hazard ratio=0.44,95%CI:0.09-2.11,P=0.31).Likewise,the incidences and risks of secondary outcomes,including septic shock,acute respiratory distress syndrome,or acute organ(kidney,liver,and cardiac)injuries,were also comparable between the DPP4i and non-DPP4i groups.The performance of DPP4i agents in achieving glucose control(e.g.,the median level of fasting blood glucose and random blood glucose)and inflammatory regulation was approximately equivalent in the DPP4i and non-DPP4i groups.Furthermore,we did not observe substantial side effects such as uncontrolled glycemia or acidosis due to DPP4i application relative to the use of non-DPP4i agents in the study cohort.CONCLUSION Our findings demonstrated that DPP4i use is not significantly associated with poor outcomes of COVID-19 or other adverse effects of anti-diabetic treatment.The data support the continuation of DPP4i agents for diabetes management in the setting of COVID-19.展开更多
The optical absorption is the most important macroscopic process to characterize the microscopic optical transition in the semiconductor materials. Recently, great enhancement has been observed in the absorption of th...The optical absorption is the most important macroscopic process to characterize the microscopic optical transition in the semiconductor materials. Recently, great enhancement has been observed in the absorption of the active region within a p–n junction. In this paper, Ga As based p–i–n samples with the active region varied from 100 nm to 3 μm were fabricated and it was observed that the external quantum efficiencies are higher than the typical results, indicating a new mechanism beyond the established theories. We proposed a theoretical model about the abnormal optical absorption process in the active region within a strong electric field, which might provide new theories for the design of the solar cells,photodetectors, and other photoelectric devices.展开更多
The performance of type-Ⅱ superlattice(T2 SL) long-wavelength infrared devices is limited by crystalline quality of T2 SLs. We optimize the process of growing molecular beam epitaxy deposition T2 SL epi-layers on Ga ...The performance of type-Ⅱ superlattice(T2 SL) long-wavelength infrared devices is limited by crystalline quality of T2 SLs. We optimize the process of growing molecular beam epitaxy deposition T2 SL epi-layers on Ga Sb(100)to improve the material properties. Samples with identical structure but diverse In/Ga beam-equivalent pressure(BEP) ratio are studied by various methods, including high-resolution x-ray diffraction, atomic force microscopy and high-resolution transmission electron microscopy. We find that appropriately increasing the In/Ga BEP ratio contributes to improving the quality of T2 SLs, but too large In BEP will much more easily cause a local strain,which can lead to more In Sb islands in the In Sb interfaces. The In Sb islands melt in the In Sb interfaces caused by the change of chemical potential of In atoms may result in the "nail" defects covering the whole T2 SLs, especially the interfaces of Ga Sb-on-In As. When the In/Ga BEP ratio is about 1, the T2 SL material possesses a lower full width at half maximum of +1 first-order satellite peak, much smoother surface and excellently larger area uniformity.展开更多
We present a method to extend the operating wavelength of the interband transition quantum well photodetector from an extended short-wavelength infrared region to a middle-wavelength infrared region. In the modified I...We present a method to extend the operating wavelength of the interband transition quantum well photodetector from an extended short-wavelength infrared region to a middle-wavelength infrared region. In the modified In As Sb quantum well, Ga Sb is replaced with Al Sb/Al Ga Sb, the valence band of the barrier material is lowered, the first restricted energy level is higher than the valence band of the barrier material, the energy band structure forms type-II structure. The photocurrent spectrum manifest that the fabricated photodetector exhibits a response range from 1.9 μm to 3.2 μm with two peaks at 2.18 μm and 3.03 μm at 78 K.展开更多
We report a type of thin film Al Ga In P red light emitting diode(RLED) on a metallic substrate by electroplating copper(Cu) to eliminate the absorption of Ga As grown substrate.The fabrication of the thin film RL...We report a type of thin film Al Ga In P red light emitting diode(RLED) on a metallic substrate by electroplating copper(Cu) to eliminate the absorption of Ga As grown substrate.The fabrication of the thin film RLED is presented in detail.Almost no degradations of epilayers properties are observed after this substrate transferred process.Photoluminescence and electroluminescence are measured to investigate the luminous characteristics.The thin film RLED shows a significant enhancement of light output power(LOP) by improving the injection efficiency and light extraction efficiency compared with the reference RLED on the Ga As parent substrate.The LOPs are specifically enhanced by 73.5% and 142% at typical injections of 2 A/cm^2 and 35 A/cm^2 respectively from electroluminescence.Moreover,reduced forward voltages,stable peak wavelengths and full widths at half maximum are obtained with the injected current increasing.These characteristic improvements are due to the Cu substrate with great current spreading and the back reflection by bottom electrodes.The substrate transferred technology based on electroplating provides an optional way to prepare high-performance optoelectronic devices,especially for thin film types.展开更多
Heterojunction phototransistors(HPTs)with scaling emitters have a higher optical gain compared to HPTs with normal emitters.However,to quantitatively describe the relationship between the emitter-absorber area ratio(A...Heterojunction phototransistors(HPTs)with scaling emitters have a higher optical gain compared to HPTs with normal emitters.However,to quantitatively describe the relationship between the emitter-absorber area ratio(Ae/Aa)and the performance of HPTs,and to find the optimum value of Ae/Aa for the geometric structure design,we develop an analytical model for the optical gain of HPTs.Moreover,five devices with different Ae/Aa are fabricated to verify the numerical analysis result.As is expected,the measurement result is in good agreement with the analysis model,both of them confirmed that devices with a smaller Ae/Aa exhibit higher optical gain.The device with area ratio of 0.0625 has the highest optical gain,which is two orders of magnitude larger than that of the device with area ratio of 1 at 3 V.However,the dark current of the device with the area ratio of 0.0625 is forty times higher than that of the device with the area ratio of 1.By calculating the signal-to-noise ratios(SNRs)of the devices,the optimal value of Ae/Aa can be obtained to be 0.16.The device with the area ratio of 0.16 has the maximum SNR.This result can be used for future design principles for high performance HPTs.展开更多
We demonstrate that a low-temperature Ga N insertion layer could significantly improve the surface morphology of non-polar a-plane Ga N.The two key factors in improving the surface morphology of non-polar a-plane Ga N...We demonstrate that a low-temperature Ga N insertion layer could significantly improve the surface morphology of non-polar a-plane Ga N.The two key factors in improving the surface morphology of non-polar a-plane Ga N are growth temperature and growth time of the Ga N insertion layer.The root-mean-square roughness of a-plane Ga N is reduced by 75%compared to the sample without the Ga N insertion layer.Meanwhile,the Ga N insertion layer is also beneficial for improving crystal quality.This work provides a simple and effective method to improve the surface morphology of non-polar a-plane Ga N.展开更多
It is known that the p–n junction of an absorption region is a crucial part for power conversion efficiency of photovoltaic power converters.We fabricate four samples with different dopant concentrations in base laye...It is known that the p–n junction of an absorption region is a crucial part for power conversion efficiency of photovoltaic power converters.We fabricate four samples with different dopant concentrations in base layers.The dependences of power conversion efficiency and fill factor on input power are displayed by photocurrent–voltage measurement.Photoluminescence characteristics under open circuit and connected circuit conditions are also studied.It is found that the status of p–n junction matching is the critical factor in affecting the power conversion efficiency.In addition,series resistance of photovoltaic power converters impairs the efficiency especially at high input powers.Both the key factors need to be considered to obtain high efficiency,and this work provides promising guidance on designing photovoltaic power converters.展开更多
Copper(0)-mediated reversible-deactivation radical polymerization(Cu(0)-mediated RDRP) of the water-soluble monomer Nisopropylacrylamide(NIPAM) has been challenging with the problems of high dispersity, poor control o...Copper(0)-mediated reversible-deactivation radical polymerization(Cu(0)-mediated RDRP) of the water-soluble monomer Nisopropylacrylamide(NIPAM) has been challenging with the problems of high dispersity, poor control over the molecular weights(MWs) or complex or multi reaction steps, etc. In this work, we report the well-controlled polymerization of NIPAM in water via a facile one-pot and one-step Cu(0)-mediated RDRP. The results of this approach show that the key for kicking off the Cu(0)-mediated NIPAM RDRPs is to ensure sufficient Cu~I at the very beginning, and the key to achieve a well-controlled chain growth is to provide adequate deactivation strength during the polymerization process. For NIPAM, which has a high propagation rate constant, the deactivation control can be effectively enhanced by extra adding deactivator(i.e., Cu~II) to the system. Moreover, a low reaction temperature(4 ℃) is necessary in the controlled synthesis of higher MW poly(Nisopropylacrylamide)(PNIPAM) to avoid the compromise in control caused by the phase transition from its lower critical solution temperature(LCST). Through this new kinetically controlled strategy, PNIPAMs with well-defined structure, narrow molecular weight distributions(MWDs) and varied MWs were successfully achieved.展开更多
China.In this study,we aimed to investigate the clinical characteristics and outcomes of patients with coronavirus disease 2019(COVID-19)in the Beijing region.Methods:In this retrospective study,we enrolled inpatients...China.In this study,we aimed to investigate the clinical characteristics and outcomes of patients with coronavirus disease 2019(COVID-19)in the Beijing region.Methods:In this retrospective study,we enrolled inpatients admitted for COVID-19 in the Fifth Medical Center of Chinese PLA General Hospital in Beijing between November 10,2022,and January 30,2023.Demographic and clinical features and treatment outcomeswere comprehensively analyzed.We used logistic regression and linear regression analyses to explore the risk factors associated with disease severity and time of nucleic acid conversion,respectively.Results:A total of 1010 hospitalized patients with COVID-19 were enrolled.The median age was 43.0 years(interquartile range,28.0–63.0),and patients aged<60 years and≥60 years comprised 71.2%and 28.8%of total included patients,respectively.The clinical classification of mild(74.6%,753/1010),moderate(21.0%,212/1010),severe(2.7%,27/1010),and unidentified(1.8%,18/1010)was separately recorded;1005 patients were discharged,and 5 patients died in the hospital.The outbreak of the emerging epidemic witnessed an evident increase in the proportion of moderate(42.9%vs.16.4%)and severe(10.3%vs.1.1%)cases after December 7,2022.Patients with a moderate/severe classification had higher levels of procalcitonin,IL-6,serum ferritin,C-reactive protein,lactic dehydrogenase,serum urea nitrogen,and D-dimer and lower counts of CD4+T,CD8+T,and B cells(all P<0.001).Multivariable regression analysis revealed that increased odds of disease severity were associated with the following factors:age≥60 years,IL-6>7 pg/mL,lactic dehydrogenase level>245 U/L,cough,and fever at admission.Age≥80 years and chronic lung diseasewere independent risk factors in the nonmild group in elderly patients.In addition,the duration for nucleic acid to turn negativewas approximately 5.0 d(interquartile range,3.0–7.0).Prolonged time of nucleic acid conversion was associated with age≥60 years,serum urea nitrogen level>8.2 mmol/L,neutrophil count>7×10^(9)/L,and the presence of a chronic lung disease or carcinoma.Finally,unvaccinated patients accounted for 37.3%of enrolled patients;children and the elder people accounted for approximately half of that.The univariable analysis found that booster doses reduced disease severity and shortened the time of nucleic acid conversion in elderly patients.Conclusions:The outbreak ofOmicron rapidly increased the number of patientswith COVID-19 in Beijing.In elderly patients,booster doses may reduce disease severity and shorten the time of nucleic acid conversion.Healthcare systems should be optimized before an emerging epidemic outbreak.展开更多
Aims:Patients with liver disease may exhibit higher infection rates and mortality rates from coronavirus disease 2019(COVID-19)than healthy individuals,and vaccination against severe acute respiratory syndrome coronav...Aims:Patients with liver disease may exhibit higher infection rates and mortality rates from coronavirus disease 2019(COVID-19)than healthy individuals,and vaccination against severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)is an effective prevention strategy.This metaanalysis aimed to assess the effectiveness and safety of SARS-CoV-2 vaccines in patients with chronic liver disease(CLD)and post-liver transplantation(LT).Methods:The PubMed,Embase,and Cochrane databases were searched.A random-effects model meta-analysis was used to determine the seropositivity rates of SARS-CoV-2 antibodies,odds ratio(OR)compared with healthy controls(HC),risk ratio(RR)between the booster and standard vaccination regimen,and the rate of adverse reactions(ADR).Results:In the standard vaccination regimen analysis,17 controlled articles were included for effectiveness analysis,and six articles for ADR analysis.The pooled seropositivity rates of SARS-CoV-2 antibodies in patients with CLD and post-LT were 93.3%(95%confidence interval[CI]:89.0%-97.6%)and 69.1%(95%CI:63.0%-75.3%),respectively.Both rates were lower than those in HC(p<0.001).The differences remained significant after sorting by detection interval,vaccine type,antibody type,or CLD type.LT recipients showed much lower seropositivity rates of antibodies than patients with CLD(69.1%vs.93.3%)or HC(OR:0.055).The pooled total ADR rate of patients was 24.0%(95%CI:16.2%-31.8%).In the booster vaccination regimen analysis,11 prospective studies were enrolled,and the seropositivity rates of antibodies after the booster dose were increased by 27%compared with those of the standard vaccination regimen(RR:1.27,95%CI:1.15-1.41,p<0.001).Conclusion:Patients with CLD and post-LT can gain protection against COVID-19 from standard vaccines,demonstrating a potentially weaker immunogenic response than HC.Booster vaccines can compensate for this deficiency.Therefore,patients with CLD and post-LT should be prioritized for receiving the COVID-19 booster vaccine.展开更多
Cu(0)-mediated reversible deactivation radical polymerization(Cu(0)-mediated RDRP) has been demonstrated as an excellent technique to control the polymerization of multiple vinyl monomers(e.g., acrylates, methacrylate...Cu(0)-mediated reversible deactivation radical polymerization(Cu(0)-mediated RDRP) has been demonstrated as an excellent technique to control the polymerization of multiple vinyl monomers(e.g., acrylates, methacrylates, and styrene). However, the complexity of the reaction mechanism and multi-component system nature make it challenging to choose the appropriate conditions and consider the factors of achieving controllable polymerization when switching from one monomer to others with different reactivities. Herein, by polymerizing two examplary monomers: methyl methacrylate(MMA) and styrene via Cu(0)-mediated RDRP under different conditions,we have found that the reaction parameters(e.g., initiator, ligand, solvent, and deactivator) play a crucial role in regulating two equilibriums:(i) mutual conversion of different copper species which determines the relative concentration of Cu(Ⅰ) and Cu(Ⅱ), and(ii)polymerization equilibrium which is the combination of activation/deactivation, propagation and termination processes. We have demonstrated that by taking both the mutual conversion of different copper species and the polymerization equilibrium into account, the optimal reaction conditions could be selected, and the well-controlled Cu(0)-mediated RDRPs of methyl methacrylate and styrene were achieved with narrow molecular weight distributions and predicted molecular weight.展开更多
Highly branched poiy(β-amino ester)s(HPAEs)have emerged as one type of the most viable non-viral gene delivery vectors,both in vitro and in viva.However,the effects of different branching strategies on the gene trans...Highly branched poiy(β-amino ester)s(HPAEs)have emerged as one type of the most viable non-viral gene delivery vectors,both in vitro and in viva.However,the effects of different branching strategies on the gene transfection performance have not yet been explored.Here,using triacrylate(B3)and diamine(B4)as the branching monomers,a series of HPAEs were synthesized via the"A2+B3+C2"and"A2+B4+C2"strategies,respectively.Results show that the branching strategy plays a pivotal role in dictating the physiological properties of the HPAE/DNA polyplexes and thus leads to obviously different cell viability and transfection efficiency.Comparatively,HPAEs synthesized via the"A2+B3+C2"branching strategy are more favorable for DNA transfection than that synthesized via the"A2+B4+C2"strategy.This study may provide new insights into the development of HPAEs based non-viral DNA delivery system.展开更多
基金the National Natural Science foundation of China(No.82204938).
文摘Dysosma versipellis is the rhizome of Bajiaolian in Berberaceae.It is a unique medicinal plant in China and it was the first to be recorded in Shennong’s Classic of Materia Medica(unknown author,25–220 C.E.).It has complex chemical components as well as complex,pharmacological and toxicological effects are extensive.Based on the recent research progress,the chemical constituents,pharmacological activities and toxicological effects of Dysosma versipellis were summarized.Combined with the core concept of quality markers of traditional Chinese medicine,the prediction and analysis were carried out from the aspects of phytogenetics and the source pathway of specific chemical constituents,traditional medicinal properties,traditional efficacy,chemical composition measurability,blood components,and pharmacokinetics,in order to provide reference for further study of Dysosma versipellis.
基金supported by the Beijing Natural Science Foundation of China,No.7122164
文摘Vagus nerve stimulation exerts protective effects against ischemic brain injury; however, the underlying mechanisms remain unclear. In this study, a rat model of focal cerebral ischemia was established using the occlusion method, and the right vagus nerve was given electrical stimula-tion (constant current of 0.5 mA; pulse width, 0.5 ms; frequency, 20 Hz; duration, 30 seconds; every 5 minutes for a total of 60 minutes) 30 minutes, 12 hours, and 1, 2, 3, 7 and 14 days after surgery. Electrical stimulation of the vagus nerve substantially reduced infarct volume, improved neurological function, and decreased the expression levels of tumor necrosis factor-α and in-terleukin-6 in rats with focal cerebral ischemia. The experimental findings indicate that the neuroprotective effect of vagus nerve stimulation following cerebral ischemia may be associated with the inhibition of tumor necrosis factor-α and interleukin-6 expression.
基金Project supported by the National Natural Science Foundation of China(Grant No.11574362)
文摘Here in this paper,we report a room-temperature operating infrared photodetector based on the interband transition of an In As Sb/Ga Sb quantum well.The interband transition energy of 5-nm thick In As(0.91)Sb(0.09) embedded in the Ga Sb barrier is calculated to be 0.53 e V(2.35μm),which makes the absorption range of In As Sb cover an entire range from short-wavelength infrared to long-wavelength infrared spectrum.The fabricated photodetector exhibits a narrow response range from 2.0μm to 2.3μm with a peak around 2.1μm at 300 K.The peak responsivity is 0.4 A/W under-500-m Vapplied bias voltage,corresponding to a peak quantum efficiency of 23.8%in the case without any anti-reflection coating.At 300 K,the photodetector exhibits a dark current density of 6.05×10^-3A/cm^2 under-400-m V applied bias voltage and 3.25×10^-5A/cm^2 under zero,separately.The peak detectivity is 6.91×10^10cm·Hz^1/2/W under zero bias voltage at 300 K.
基金Supported by National Key R&D Program of China,No.2019YFC2004702 and No.2020YFC0845500the National Natural Science Foundation of China,No.81970070 and No.81970011the Hubei Science and Technology Support Project,No.2019BFC582 and No.2018BEC473.
文摘BACKGROUND Dipeptidyl peptidase-4(DPP4)is commonly targeted to achieve glycemic control and has potent anti-inflammatory and immunoregulatory effects.Recent structural analyses indicated a potential tight interaction between DPP4 and severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),raising a promising hypothesis that DPP4 inhibitor(DPP4i)drugs might be an optimal strategy for treating coronavirus disease 2019(COVID-19)among patients with diabetes.However,there has been no direct clinical evidence illuminating the associations between DPP4i use and COVID-19 outcomes.AIM To illuminate the associations between DPP4i usage and the adverse outcomes of COVID-19.METHODS We conducted a multicenter,retrospective analysis including 2563 patients with type 2 diabetes who were hospitalized due to COVID-19 at 16 hospitals in Hubei Province,China.After excluding ineligible individuals,142 patients who received DPP4i drugs and 1115 patients who received non-DPP4i oral anti-diabetic drugs were included in the subsequent analysis.We performed a strict propensity score matching(PSM)analysis where age,sex,comorbidities,number of oral hypoglycemic agents,heart rate,blood pressure,pulse oxygen saturation(SpO2)<95%,CT diagnosed bilateral lung lesions,laboratory indicators,and proportion of insulin usage were matched.Finally,111 participants treated with DPP4i drugs were successfully matched to 333 non-DPP4i users.Then,a linear logistic model and mixed-effect Cox model were applied to analyze the associations between inhospital DPP4i use and adverse outcomes of COVID-19.RESULTS After rigorous matching and further adjustments for imbalanced variables in the linear logistic model and Cox adjusted model,we found that there was no significant association between in-hospital DPP4i use(DPP4i group)and 28-d allcause mortality(adjusted hazard ratio=0.44,95%CI:0.09-2.11,P=0.31).Likewise,the incidences and risks of secondary outcomes,including septic shock,acute respiratory distress syndrome,or acute organ(kidney,liver,and cardiac)injuries,were also comparable between the DPP4i and non-DPP4i groups.The performance of DPP4i agents in achieving glucose control(e.g.,the median level of fasting blood glucose and random blood glucose)and inflammatory regulation was approximately equivalent in the DPP4i and non-DPP4i groups.Furthermore,we did not observe substantial side effects such as uncontrolled glycemia or acidosis due to DPP4i application relative to the use of non-DPP4i agents in the study cohort.CONCLUSION Our findings demonstrated that DPP4i use is not significantly associated with poor outcomes of COVID-19 or other adverse effects of anti-diabetic treatment.The data support the continuation of DPP4i agents for diabetes management in the setting of COVID-19.
基金Project supported by the National Natural Science Foundation of China(Grant No.61991441)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB33000000).
文摘The optical absorption is the most important macroscopic process to characterize the microscopic optical transition in the semiconductor materials. Recently, great enhancement has been observed in the absorption of the active region within a p–n junction. In this paper, Ga As based p–i–n samples with the active region varied from 100 nm to 3 μm were fabricated and it was observed that the external quantum efficiencies are higher than the typical results, indicating a new mechanism beyond the established theories. We proposed a theoretical model about the abnormal optical absorption process in the active region within a strong electric field, which might provide new theories for the design of the solar cells,photodetectors, and other photoelectric devices.
基金Supported by the National Key Research and Development Program of China(Grant Nos.2016YFB0402402 and2016YFB0400601)the National Basic Research Program of China(Grant No.2015CB351902)+3 种基金the National Science and Technology Major Project(2018ZX01005101-010)the National Natural Science Foundation of China(Grant Nos.61835011 and U1431231)the Key Research Projects of the Frontier Science of the Chinese Academy of Sciences(Grant No.QYZDY-SSW-JSC004)the Beijing Science and Technology Projects(Grant No.Z151100001615042)。
文摘The performance of type-Ⅱ superlattice(T2 SL) long-wavelength infrared devices is limited by crystalline quality of T2 SLs. We optimize the process of growing molecular beam epitaxy deposition T2 SL epi-layers on Ga Sb(100)to improve the material properties. Samples with identical structure but diverse In/Ga beam-equivalent pressure(BEP) ratio are studied by various methods, including high-resolution x-ray diffraction, atomic force microscopy and high-resolution transmission electron microscopy. We find that appropriately increasing the In/Ga BEP ratio contributes to improving the quality of T2 SLs, but too large In BEP will much more easily cause a local strain,which can lead to more In Sb islands in the In Sb interfaces. The In Sb islands melt in the In Sb interfaces caused by the change of chemical potential of In atoms may result in the "nail" defects covering the whole T2 SLs, especially the interfaces of Ga Sb-on-In As. When the In/Ga BEP ratio is about 1, the T2 SL material possesses a lower full width at half maximum of +1 first-order satellite peak, much smoother surface and excellently larger area uniformity.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11574362,61210014,11374340,and 11474205)the Innovative Clean-Energy Research and Application Program of Beijing Municipal Science and Technology Commission of China(Grant No.Z151100003515001)the National Key Technology R&D Program of China(Grant No.2016YFB0400302)。
文摘We present a method to extend the operating wavelength of the interband transition quantum well photodetector from an extended short-wavelength infrared region to a middle-wavelength infrared region. In the modified In As Sb quantum well, Ga Sb is replaced with Al Sb/Al Ga Sb, the valence band of the barrier material is lowered, the first restricted energy level is higher than the valence band of the barrier material, the energy band structure forms type-II structure. The photocurrent spectrum manifest that the fabricated photodetector exhibits a response range from 1.9 μm to 3.2 μm with two peaks at 2.18 μm and 3.03 μm at 78 K.
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2016YFB0400600 and 2016YFB0400603)the National Natural Science Foundation of China(Grant Nos.11574362,61210014,and 11374340)
文摘We report a type of thin film Al Ga In P red light emitting diode(RLED) on a metallic substrate by electroplating copper(Cu) to eliminate the absorption of Ga As grown substrate.The fabrication of the thin film RLED is presented in detail.Almost no degradations of epilayers properties are observed after this substrate transferred process.Photoluminescence and electroluminescence are measured to investigate the luminous characteristics.The thin film RLED shows a significant enhancement of light output power(LOP) by improving the injection efficiency and light extraction efficiency compared with the reference RLED on the Ga As parent substrate.The LOPs are specifically enhanced by 73.5% and 142% at typical injections of 2 A/cm^2 and 35 A/cm^2 respectively from electroluminescence.Moreover,reduced forward voltages,stable peak wavelengths and full widths at half maximum are obtained with the injected current increasing.These characteristic improvements are due to the Cu substrate with great current spreading and the back reflection by bottom electrodes.The substrate transferred technology based on electroplating provides an optional way to prepare high-performance optoelectronic devices,especially for thin film types.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11574362,61210014,11374340 and 11474205the Innovative Clean-Energy Research and Application Program of Beijing Municipal Science and Technology Commission under Grant No Z151100003515001the National Key Technology R&D Program of China under Grant No 2016YFB0400302
文摘Heterojunction phototransistors(HPTs)with scaling emitters have a higher optical gain compared to HPTs with normal emitters.However,to quantitatively describe the relationship between the emitter-absorber area ratio(Ae/Aa)and the performance of HPTs,and to find the optimum value of Ae/Aa for the geometric structure design,we develop an analytical model for the optical gain of HPTs.Moreover,five devices with different Ae/Aa are fabricated to verify the numerical analysis result.As is expected,the measurement result is in good agreement with the analysis model,both of them confirmed that devices with a smaller Ae/Aa exhibit higher optical gain.The device with area ratio of 0.0625 has the highest optical gain,which is two orders of magnitude larger than that of the device with area ratio of 1 at 3 V.However,the dark current of the device with the area ratio of 0.0625 is forty times higher than that of the device with the area ratio of 1.By calculating the signal-to-noise ratios(SNRs)of the devices,the optimal value of Ae/Aa can be obtained to be 0.16.The device with the area ratio of 0.16 has the maximum SNR.This result can be used for future design principles for high performance HPTs.
基金Supported by the National Natural Science Foundation of China(Grant Nos.11574362 and 61704008)。
文摘We demonstrate that a low-temperature Ga N insertion layer could significantly improve the surface morphology of non-polar a-plane Ga N.The two key factors in improving the surface morphology of non-polar a-plane Ga N are growth temperature and growth time of the Ga N insertion layer.The root-mean-square roughness of a-plane Ga N is reduced by 75%compared to the sample without the Ga N insertion layer.Meanwhile,the Ga N insertion layer is also beneficial for improving crystal quality.This work provides a simple and effective method to improve the surface morphology of non-polar a-plane Ga N.
基金Supported by the National Natural Science Foundation of China(Grant Nos.61704008 and 11574362)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB33000000).
文摘It is known that the p–n junction of an absorption region is a crucial part for power conversion efficiency of photovoltaic power converters.We fabricate four samples with different dopant concentrations in base layers.The dependences of power conversion efficiency and fill factor on input power are displayed by photocurrent–voltage measurement.Photoluminescence characteristics under open circuit and connected circuit conditions are also studied.It is found that the status of p–n junction matching is the critical factor in affecting the power conversion efficiency.In addition,series resistance of photovoltaic power converters impairs the efficiency especially at high input powers.Both the key factors need to be considered to obtain high efficiency,and this work provides promising guidance on designing photovoltaic power converters.
基金financially supported by the Science Foundation Ireland (SFI) Frontiers for the Future 2019 call (No.19/FFP/6522)the National Natural Science Foundation of China (NSFC)(No.51873179)Irish Research Council (IRC) Government of Ireland Postdoctoral Fellowship (No.GOIPD/2022/209)。
文摘Copper(0)-mediated reversible-deactivation radical polymerization(Cu(0)-mediated RDRP) of the water-soluble monomer Nisopropylacrylamide(NIPAM) has been challenging with the problems of high dispersity, poor control over the molecular weights(MWs) or complex or multi reaction steps, etc. In this work, we report the well-controlled polymerization of NIPAM in water via a facile one-pot and one-step Cu(0)-mediated RDRP. The results of this approach show that the key for kicking off the Cu(0)-mediated NIPAM RDRPs is to ensure sufficient Cu~I at the very beginning, and the key to achieve a well-controlled chain growth is to provide adequate deactivation strength during the polymerization process. For NIPAM, which has a high propagation rate constant, the deactivation control can be effectively enhanced by extra adding deactivator(i.e., Cu~II) to the system. Moreover, a low reaction temperature(4 ℃) is necessary in the controlled synthesis of higher MW poly(Nisopropylacrylamide)(PNIPAM) to avoid the compromise in control caused by the phase transition from its lower critical solution temperature(LCST). Through this new kinetically controlled strategy, PNIPAMs with well-defined structure, narrow molecular weight distributions(MWDs) and varied MWs were successfully achieved.
基金supported by the National Natural Science Foundation of China(82370019)the Emergency Key Program of Guangzhou Laboratory(EKPG21-30-4)+1 种基金the National Key Research and Development Plan(2022YFC2304404,2022YFC2304803)the Military Emergency Research Project on COVID-19(BWS20J006).
文摘China.In this study,we aimed to investigate the clinical characteristics and outcomes of patients with coronavirus disease 2019(COVID-19)in the Beijing region.Methods:In this retrospective study,we enrolled inpatients admitted for COVID-19 in the Fifth Medical Center of Chinese PLA General Hospital in Beijing between November 10,2022,and January 30,2023.Demographic and clinical features and treatment outcomeswere comprehensively analyzed.We used logistic regression and linear regression analyses to explore the risk factors associated with disease severity and time of nucleic acid conversion,respectively.Results:A total of 1010 hospitalized patients with COVID-19 were enrolled.The median age was 43.0 years(interquartile range,28.0–63.0),and patients aged<60 years and≥60 years comprised 71.2%and 28.8%of total included patients,respectively.The clinical classification of mild(74.6%,753/1010),moderate(21.0%,212/1010),severe(2.7%,27/1010),and unidentified(1.8%,18/1010)was separately recorded;1005 patients were discharged,and 5 patients died in the hospital.The outbreak of the emerging epidemic witnessed an evident increase in the proportion of moderate(42.9%vs.16.4%)and severe(10.3%vs.1.1%)cases after December 7,2022.Patients with a moderate/severe classification had higher levels of procalcitonin,IL-6,serum ferritin,C-reactive protein,lactic dehydrogenase,serum urea nitrogen,and D-dimer and lower counts of CD4+T,CD8+T,and B cells(all P<0.001).Multivariable regression analysis revealed that increased odds of disease severity were associated with the following factors:age≥60 years,IL-6>7 pg/mL,lactic dehydrogenase level>245 U/L,cough,and fever at admission.Age≥80 years and chronic lung diseasewere independent risk factors in the nonmild group in elderly patients.In addition,the duration for nucleic acid to turn negativewas approximately 5.0 d(interquartile range,3.0–7.0).Prolonged time of nucleic acid conversion was associated with age≥60 years,serum urea nitrogen level>8.2 mmol/L,neutrophil count>7×10^(9)/L,and the presence of a chronic lung disease or carcinoma.Finally,unvaccinated patients accounted for 37.3%of enrolled patients;children and the elder people accounted for approximately half of that.The univariable analysis found that booster doses reduced disease severity and shortened the time of nucleic acid conversion in elderly patients.Conclusions:The outbreak ofOmicron rapidly increased the number of patientswith COVID-19 in Beijing.In elderly patients,booster doses may reduce disease severity and shorten the time of nucleic acid conversion.Healthcare systems should be optimized before an emerging epidemic outbreak.
基金The National Key R&D Program of China,Grant/Award Number:2020YFC0860900The Emergency Key Program of Guangzhou Laboratory,Grant/Award Number:EKPG21-30-4。
文摘Aims:Patients with liver disease may exhibit higher infection rates and mortality rates from coronavirus disease 2019(COVID-19)than healthy individuals,and vaccination against severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)is an effective prevention strategy.This metaanalysis aimed to assess the effectiveness and safety of SARS-CoV-2 vaccines in patients with chronic liver disease(CLD)and post-liver transplantation(LT).Methods:The PubMed,Embase,and Cochrane databases were searched.A random-effects model meta-analysis was used to determine the seropositivity rates of SARS-CoV-2 antibodies,odds ratio(OR)compared with healthy controls(HC),risk ratio(RR)between the booster and standard vaccination regimen,and the rate of adverse reactions(ADR).Results:In the standard vaccination regimen analysis,17 controlled articles were included for effectiveness analysis,and six articles for ADR analysis.The pooled seropositivity rates of SARS-CoV-2 antibodies in patients with CLD and post-LT were 93.3%(95%confidence interval[CI]:89.0%-97.6%)and 69.1%(95%CI:63.0%-75.3%),respectively.Both rates were lower than those in HC(p<0.001).The differences remained significant after sorting by detection interval,vaccine type,antibody type,or CLD type.LT recipients showed much lower seropositivity rates of antibodies than patients with CLD(69.1%vs.93.3%)or HC(OR:0.055).The pooled total ADR rate of patients was 24.0%(95%CI:16.2%-31.8%).In the booster vaccination regimen analysis,11 prospective studies were enrolled,and the seropositivity rates of antibodies after the booster dose were increased by 27%compared with those of the standard vaccination regimen(RR:1.27,95%CI:1.15-1.41,p<0.001).Conclusion:Patients with CLD and post-LT can gain protection against COVID-19 from standard vaccines,demonstrating a potentially weaker immunogenic response than HC.Booster vaccines can compensate for this deficiency.Therefore,patients with CLD and post-LT should be prioritized for receiving the COVID-19 booster vaccine.
基金financially supported by the National Natural Science Foundation of China (No. 51573129)Science Foundation Ireland (SFI) Principal Investigator Award (No. 13/IA/1962)+1 种基金Investigator Award (No. 12/IP/1688)Health Research Board (No. HRA-POR-2013-412)
文摘Cu(0)-mediated reversible deactivation radical polymerization(Cu(0)-mediated RDRP) has been demonstrated as an excellent technique to control the polymerization of multiple vinyl monomers(e.g., acrylates, methacrylates, and styrene). However, the complexity of the reaction mechanism and multi-component system nature make it challenging to choose the appropriate conditions and consider the factors of achieving controllable polymerization when switching from one monomer to others with different reactivities. Herein, by polymerizing two examplary monomers: methyl methacrylate(MMA) and styrene via Cu(0)-mediated RDRP under different conditions,we have found that the reaction parameters(e.g., initiator, ligand, solvent, and deactivator) play a crucial role in regulating two equilibriums:(i) mutual conversion of different copper species which determines the relative concentration of Cu(Ⅰ) and Cu(Ⅱ), and(ii)polymerization equilibrium which is the combination of activation/deactivation, propagation and termination processes. We have demonstrated that by taking both the mutual conversion of different copper species and the polymerization equilibrium into account, the optimal reaction conditions could be selected, and the well-controlled Cu(0)-mediated RDRPs of methyl methacrylate and styrene were achieved with narrow molecular weight distributions and predicted molecular weight.
基金This work was financially supported by Science Foundation Ireland(SFI)Principal Investigator Program(No.13/IA/1962)the National Natural Science Foundation of China(Nos.51873179,51903202),and University College Dublin。
文摘Highly branched poiy(β-amino ester)s(HPAEs)have emerged as one type of the most viable non-viral gene delivery vectors,both in vitro and in viva.However,the effects of different branching strategies on the gene transfection performance have not yet been explored.Here,using triacrylate(B3)and diamine(B4)as the branching monomers,a series of HPAEs were synthesized via the"A2+B3+C2"and"A2+B4+C2"strategies,respectively.Results show that the branching strategy plays a pivotal role in dictating the physiological properties of the HPAE/DNA polyplexes and thus leads to obviously different cell viability and transfection efficiency.Comparatively,HPAEs synthesized via the"A2+B3+C2"branching strategy are more favorable for DNA transfection than that synthesized via the"A2+B4+C2"strategy.This study may provide new insights into the development of HPAEs based non-viral DNA delivery system.