To evaluate and predict liver fibrosis in patients with nonalcoholic fatty liver disease(NAFLD),several non-invasive scoring systems were built and widely used in the progress of diagnosis and treatment,which showed g...To evaluate and predict liver fibrosis in patients with nonalcoholic fatty liver disease(NAFLD),several non-invasive scoring systems were built and widely used in the progress of diagnosis and treatment,which showed great diagnostic efficiency,such as aspartate aminotransferase to platelet ratio index,fibrosis-4 index,body mass index,aspartate aminotransferase to alanine aminotransferase ratio,diabetes score and NAFLD fibrosis score.Since the new concept of metabolic associated fatty liver disease(MAFLD)was proposed,the clinical application value of the non-invasive scoring systems mentioned above has not been assessed in MAFLD.The evaluation of the diagnostic performance of these non-invasive scoring systems will provide references for clinicians in the diagnosis of MAFLD.展开更多
Electromagnetically induced transparency (EIT) having wide applications in quantum optics and nonlinear optics is explored ordinarily in various atomic systems. In this paper we present a theoretical study of EIT usin...Electromagnetically induced transparency (EIT) having wide applications in quantum optics and nonlinear optics is explored ordinarily in various atomic systems. In this paper we present a theoretical study of EIT using supercon- ducting circuit with a V-type artificial molecule constructed by two Josephson charge qubits coupled each other through a large capacitor. In our theoretical model we make a steady state approximation and obtain the analytical expressions of the complex susceptibility for the artificial system via the density matrix formalism. The complex susceptibility has additional dependence on the qubit parameters and hence can be tuned to a certain extent.展开更多
Numerous studies indicate that target gene silencing by RNA interference (RNAi) could lead to insect death. This phenomenon has been considered as a potential strategy for insect pest control, and it is termed RNAi-...Numerous studies indicate that target gene silencing by RNA interference (RNAi) could lead to insect death. This phenomenon has been considered as a potential strategy for insect pest control, and it is termed RNAi-mediated crop protection. However, there are many limitations using RNAi-based technology for pest control, with the effectiveness target gene selection and reliable double-strand RNA (dsRNA) delivery being two of the major challenges. With respect to target gene selection, at present, the use of homologous genes and genome-scale high-throughput screening are the main strategies adopted by researchers. Once the target gene is identified, dsRNA can be delivered by micro-injection or by feeding as a dietary component. However, micro-injection, which is the most common method, can only be used in laboratory experiments. Expression of dsRNAs directed against insect genes in transgenic plants and spraying dsRNA reagents have been shown to induce RNAi effects on target insects. Hence, RNAi-mediated crop protection has been considered as a potential new-generation technology for pest control, or as a complementary method of existing pest control strategies; however, further devel- opment to improve the efficacy of protection and range of species affected is necessary. In this review, we have summarized current research on RNAi-based technology for pest insect management. Current progress has proven that RNAi technology has the potential to be a tool for designing a new generation of insect control measures. To accelerate its practical application in crop protection, further study on dsRNA uptake mechanisms based on the knowledge of insect physiology and biochemistry is needed.展开更多
Gd50Al3oCo20 wires show excellent magnetocaloric properties and high heat exchange rate due to the microsize. The Weibull and lognormal methods were used for systematically analyzing its mechanical properties for matc...Gd50Al3oCo20 wires show excellent magnetocaloric properties and high heat exchange rate due to the microsize. The Weibull and lognormal methods were used for systematically analyzing its mechanical properties for matching the design requirements in cooling system. The wire exhibits average fracture strength of-969.5 MPa and typical fracture behavior of amorphous character. Moreover, the distributions of stresses for tensile strains at 10 values are estimated by probability plot and Chi-square goodness-of-fit test. The random stresses were best fitted by lognormal probability distribution for most studied cases; however, fracture strength was best fitted by Weibull probability distribution. It is interesting to note that the mean and standard deviation of the stresses (to reach specific tensile strain) increase as the tensile strain grows, accompanied by the coefficients of variation of stresses which decrease smoothly. It is concluded that the inhomogeneity of material does cause the scatter of stresses growth, and the scatter could be considerably large.展开更多
The brown planthopper (BPH, Nilaparvata lugens) is a destructive, monophagous, piercing-sucking insect pest of rice. Previous studies indicated that jasmonic acid (JA) positively regulates rice defense against che...The brown planthopper (BPH, Nilaparvata lugens) is a destructive, monophagous, piercing-sucking insect pest of rice. Previous studies indicated that jasmonic acid (JA) positively regulates rice defense against chewing insect pests but negatively regulates it against the piercing-sucking insect of BPH. We here demonstrated that overexpression of allene oxide cyclase (AOC) but not OPR3 (cis-12-oxo-phytodienoic acid (OPDA) reductase 3, an enzyme adjacent to AOC in the JA synthetic pathway) significantly increased rice resistance to BPH, mainly by reducing the feeding activity and survival rate. Further anal- ysis revealed that plant response to BPH under AOC overexpression was independent of the JA pathway and that significantly higher OPDA levels stimulated rice resistance to BPH. Microarray analysis identified multiple candidate resistance-related genes underAOCoverexpression. OPDA treatment stimulated the resistance of radish seedlings to green peach aphid Myzus persicae, another piercing-sucking insect. These results imply that rice resistance to chewing insects and to sucking insects can be enhanced simultaneously through AOC-mediated increases of JA and OPDA and provide direct evidence of the potential application of OPDA in stimulating plant defense responses to piercing-sucking insect pests in agriculture.展开更多
Background:The coronavirus disease 2019 (COVID-19) outbreak occurred during the flu season around the world. This study aimed to analyze the impact of influenza A virus (IAV) exposure on COVID-19.Methods:Seventy COVID...Background:The coronavirus disease 2019 (COVID-19) outbreak occurred during the flu season around the world. This study aimed to analyze the impact of influenza A virus (IAV) exposure on COVID-19.Methods:Seventy COVID-19 patients admitted to the hospital during January and February 2020 in Wuhan, China were included in this retrospective study. Serum tests including respiratory pathogen immunoglobulin M (IgM) and inflammation biomarkers were performed upon admission. Patients were divided into common, severe, and critical types according to disease severity. Symptoms, inflammation indices, disease severity, and fatality rate were compared between anti-IAV IgM-positive and anti-IAV IgM-negative groups. The effects of the empirical use of oseltamivir were also analyzed in both groups. For comparison between groups, t tests and the Mann-Whitney U test were used according to data distribution. The Chi-squared test was used to compare disease severity and fatality between groups. Results:Thirty-two (45.71%) of the 70 patients had positive anti-IAV IgM. Compared with the IAV-negative group, the positive group showed significantly higher proportions of female patients (59.38% vs. 34.21%, χ^2 = 4.43, P = 0.035) and patients with fatigue (59.38% vs. 34.21%, χ^2 = 4.43, P = 0.035). The levels of soluble interleukin 2 receptor (median 791.00 vs. 1075.50 IU/mL, Z = -2.70, P = 0.007) and tumor necrosis factor α (median 10.75 vs. 11.50 pg/mL, Z = -2.18, P = 0.029) were significantly lower in the IAV-positive group. Furthermore, this group tended to have a higher proportion of critical patients (31.25% vs. 15.79%, P = 0.066) and a higher fatality rate (21.88% vs. 7.89%, P = 0.169). Notably, in the IAV-positive group, patients who received oseltamivir had a significantly lower fatality rate (0 vs. 36.84%, P = 0.025) compared with those not receiving oseltamivir. Conclusions:The study suggests that during the flu season, close attention should be paid to the probability of IAV exposure in COVID-19 patients. Prospective studies with larger sample sizes are needed to clarify whether IAV increases the fatality rate of COVID-19 and to elucidate any benefits of empirical usage of oseltamivir.展开更多
When using RNA interference (RNAi) to study gene functions in Lepidoptera insects, we discovered that some genes could not be suppressed; instead, their expression levels could be up-regulated by double-stranded RNA...When using RNA interference (RNAi) to study gene functions in Lepidoptera insects, we discovered that some genes could not be suppressed; instead, their expression levels could be up-regulated by double-stranded RNA (dsRNA). To predict which genes could be easily silenced, we treated the Asian corn borer (Ostriniafilrnacalis) with dsGFP (green fluorescent protein) and dsMLP (muscle lim protein). A transcriptome sequence analysis was conducted using the cDNAs 6 h after treatment with dsRNA. The results indicated that 160 genes were up-regulated and 44 genes were down-regulated by the two dsRNAs. Then, 50 co-up-regulated, 25 co-down-regulated and 43 unaffected genes were selected to determine their RNAi responses. All the 25 down-regulated genes were knocked down by their corresponding dsRNA. However, several of the up-regulated and unaffected genes were up-regulated when treated with their corresponding dsRNAs instead of being knocked down. The genes up-regulated by the dsGFP treatment may be involved in insect immune responses or the RNAi pathway. When the immune-related genes were excluded, only seven genes were induced by dsGFP, including ago-2 and dicer-2. These results not only provide a reference for efficient RNAi target predications, but also provide some potential RNAi pathway-related genes for further study.展开更多
Four Zn-rich Al-Zn-Mg-Cu alloys with different Mg and Cu contents were fabricated by spray deposition.The effects of Mg and Cu contents on the aging behaviors of the whole precipitation process of the alloys were syst...Four Zn-rich Al-Zn-Mg-Cu alloys with different Mg and Cu contents were fabricated by spray deposition.The effects of Mg and Cu contents on the aging behaviors of the whole precipitation process of the alloys were systematically investigated.The results show that the primary precipitates in the under-aged and peak-aged alloys are GPⅡ and η'phases;no GPⅠ zones were observed.During aging,the dissolution driving force of the precipitates increases with increasing Mg content;therefore,the volume fraction of precipitates in the grain interior and the area fraction of precipitates at the grain boundary increase obviously,which contributes to a considerable improvement in yield strength and decrease in plasticity of the high Mg content alloys.Cu content has no apparent effect on the size and volume fraction of precipitates.However,a higher Cu content can effectively prevent coarsening and transformation of precipitates,which is beneficial to maintain the peak aging state of the alloys.This research provides a basis for the composition optimization of the rapid-solidified highly alloying Al-Zn-Mg-Cu alloys.展开更多
Background and Aims:Previous meta-analyses have shown that aspirin use may reduce the risk of hepatocellular carcinoma(HCC).However,the optimal dose,frequency,and duration of aspirin use or the safety and efficacy of ...Background and Aims:Previous meta-analyses have shown that aspirin use may reduce the risk of hepatocellular carcinoma(HCC).However,the optimal dose,frequency,and duration of aspirin use or the safety and efficacy of aspirin in target populations for HCC prevention remain unclear.The study aim was to investigate the efficacy and safety of aspirin for prevention of HCC.Methods:Publications were retrieved by a comprehensive literature research of several databases.Based on a random-effects model,hazard ratios(HRs)and the corresponding 95%confidence intervals(CIs)were used to assess the pooled risk.The dose-response relationship between aspirin use and HCC risk was assessed with a restricted cubic spline model.Results:Twenty-two studies were included in the metaanalysis.Aspirin use was associated with a reduced risk of HCC(HR=0.64,95%CI:0.56–0.75).The effect was robust across sex and age;however,women and the non-elderly had the greatest benefit from aspirin use.The preventive effect was well reproduced in those with comorbidities.Daily use and long-term use of aspirin appeared to offer greater benefits.Aspirin 100 mg/d was associated with maximum reduction of HCC risk.Aspirin use did slightly increase the risk of bleeding(HR=1.14,95%CI:1.02–1.27).Conclusions:Our meta-analysis confirmed that use of aspirin significantly reduced the incident risk of HCC.Regular and long-term aspirin use offers a greater advantage.Aspirin use was associated with an increased risk of bleeding.We recommend 100 mg/d aspirin as a feasible dose for further research on primary prevention of HCC in a broad at-risk population.展开更多
文摘To evaluate and predict liver fibrosis in patients with nonalcoholic fatty liver disease(NAFLD),several non-invasive scoring systems were built and widely used in the progress of diagnosis and treatment,which showed great diagnostic efficiency,such as aspartate aminotransferase to platelet ratio index,fibrosis-4 index,body mass index,aspartate aminotransferase to alanine aminotransferase ratio,diabetes score and NAFLD fibrosis score.Since the new concept of metabolic associated fatty liver disease(MAFLD)was proposed,the clinical application value of the non-invasive scoring systems mentioned above has not been assessed in MAFLD.The evaluation of the diagnostic performance of these non-invasive scoring systems will provide references for clinicians in the diagnosis of MAFLD.
文摘Electromagnetically induced transparency (EIT) having wide applications in quantum optics and nonlinear optics is explored ordinarily in various atomic systems. In this paper we present a theoretical study of EIT using supercon- ducting circuit with a V-type artificial molecule constructed by two Josephson charge qubits coupled each other through a large capacitor. In our theoretical model we make a steady state approximation and obtain the analytical expressions of the complex susceptibility for the artificial system via the density matrix formalism. The complex susceptibility has additional dependence on the qubit parameters and hence can be tuned to a certain extent.
文摘Numerous studies indicate that target gene silencing by RNA interference (RNAi) could lead to insect death. This phenomenon has been considered as a potential strategy for insect pest control, and it is termed RNAi-mediated crop protection. However, there are many limitations using RNAi-based technology for pest control, with the effectiveness target gene selection and reliable double-strand RNA (dsRNA) delivery being two of the major challenges. With respect to target gene selection, at present, the use of homologous genes and genome-scale high-throughput screening are the main strategies adopted by researchers. Once the target gene is identified, dsRNA can be delivered by micro-injection or by feeding as a dietary component. However, micro-injection, which is the most common method, can only be used in laboratory experiments. Expression of dsRNAs directed against insect genes in transgenic plants and spraying dsRNA reagents have been shown to induce RNAi effects on target insects. Hence, RNAi-mediated crop protection has been considered as a potential new-generation technology for pest control, or as a complementary method of existing pest control strategies; however, further devel- opment to improve the efficacy of protection and range of species affected is necessary. In this review, we have summarized current research on RNAi-based technology for pest insect management. Current progress has proven that RNAi technology has the potential to be a tool for designing a new generation of insect control measures. To accelerate its practical application in crop protection, further study on dsRNA uptake mechanisms based on the knowledge of insect physiology and biochemistry is needed.
基金The authors are thankful for the supports from the Key National Natural Science Foundation of China (No. U1533202), the Shandong Independent Innovation and Achievements Transformation Fund (No. 2014CGZHl101), the Civil Aviation Administration of China (No. MHRD20150104), National Sciencetechnology Support Plan Project "the application paradigm of full lifecycle information closed-loop management for construction machinery" (No. 2015BAF32B01-4) and National Natural Science Foundation of China (Nos. 51775132, 51671071 and 51371067).
文摘Gd50Al3oCo20 wires show excellent magnetocaloric properties and high heat exchange rate due to the microsize. The Weibull and lognormal methods were used for systematically analyzing its mechanical properties for matching the design requirements in cooling system. The wire exhibits average fracture strength of-969.5 MPa and typical fracture behavior of amorphous character. Moreover, the distributions of stresses for tensile strains at 10 values are estimated by probability plot and Chi-square goodness-of-fit test. The random stresses were best fitted by lognormal probability distribution for most studied cases; however, fracture strength was best fitted by Weibull probability distribution. It is interesting to note that the mean and standard deviation of the stresses (to reach specific tensile strain) increase as the tensile strain grows, accompanied by the coefficients of variation of stresses which decrease smoothly. It is concluded that the inhomogeneity of material does cause the scatter of stresses growth, and the scatter could be considerably large.
基金This study was supported by the National Basic Research Program of China (2010CB126200) and the National Natural Science Foundation of China (31371949).
文摘The brown planthopper (BPH, Nilaparvata lugens) is a destructive, monophagous, piercing-sucking insect pest of rice. Previous studies indicated that jasmonic acid (JA) positively regulates rice defense against chewing insect pests but negatively regulates it against the piercing-sucking insect of BPH. We here demonstrated that overexpression of allene oxide cyclase (AOC) but not OPR3 (cis-12-oxo-phytodienoic acid (OPDA) reductase 3, an enzyme adjacent to AOC in the JA synthetic pathway) significantly increased rice resistance to BPH, mainly by reducing the feeding activity and survival rate. Further anal- ysis revealed that plant response to BPH under AOC overexpression was independent of the JA pathway and that significantly higher OPDA levels stimulated rice resistance to BPH. Microarray analysis identified multiple candidate resistance-related genes underAOCoverexpression. OPDA treatment stimulated the resistance of radish seedlings to green peach aphid Myzus persicae, another piercing-sucking insect. These results imply that rice resistance to chewing insects and to sucking insects can be enhanced simultaneously through AOC-mediated increases of JA and OPDA and provide direct evidence of the potential application of OPDA in stimulating plant defense responses to piercing-sucking insect pests in agriculture.
基金grants from the Special Research Fund of Peking University Health Science Center for Prevention and Control of COVID-19the Fundamental Research Funds for the Central Universities(No.BMU2020HKYZX003).
文摘Background:The coronavirus disease 2019 (COVID-19) outbreak occurred during the flu season around the world. This study aimed to analyze the impact of influenza A virus (IAV) exposure on COVID-19.Methods:Seventy COVID-19 patients admitted to the hospital during January and February 2020 in Wuhan, China were included in this retrospective study. Serum tests including respiratory pathogen immunoglobulin M (IgM) and inflammation biomarkers were performed upon admission. Patients were divided into common, severe, and critical types according to disease severity. Symptoms, inflammation indices, disease severity, and fatality rate were compared between anti-IAV IgM-positive and anti-IAV IgM-negative groups. The effects of the empirical use of oseltamivir were also analyzed in both groups. For comparison between groups, t tests and the Mann-Whitney U test were used according to data distribution. The Chi-squared test was used to compare disease severity and fatality between groups. Results:Thirty-two (45.71%) of the 70 patients had positive anti-IAV IgM. Compared with the IAV-negative group, the positive group showed significantly higher proportions of female patients (59.38% vs. 34.21%, χ^2 = 4.43, P = 0.035) and patients with fatigue (59.38% vs. 34.21%, χ^2 = 4.43, P = 0.035). The levels of soluble interleukin 2 receptor (median 791.00 vs. 1075.50 IU/mL, Z = -2.70, P = 0.007) and tumor necrosis factor α (median 10.75 vs. 11.50 pg/mL, Z = -2.18, P = 0.029) were significantly lower in the IAV-positive group. Furthermore, this group tended to have a higher proportion of critical patients (31.25% vs. 15.79%, P = 0.066) and a higher fatality rate (21.88% vs. 7.89%, P = 0.169). Notably, in the IAV-positive group, patients who received oseltamivir had a significantly lower fatality rate (0 vs. 36.84%, P = 0.025) compared with those not receiving oseltamivir. Conclusions:The study suggests that during the flu season, close attention should be paid to the probability of IAV exposure in COVID-19 patients. Prospective studies with larger sample sizes are needed to clarify whether IAV increases the fatality rate of COVID-19 and to elucidate any benefits of empirical usage of oseltamivir.
基金This work was supported by the National Basic Research Program of China (2015CB755703), the National Transgenic Great Subject from the Ministry of Agriculture of China (2016ZX08009-003-001), the Key Deployment Project from the Chinese Academy of Sciences (KSZD-EW-Z-021-2-1) and the National Natural Science Foundation of China (31672354 and 31402012). The funders had no role in study design, data collection or analysis, decision to publish, or preparation of the manuscript.
文摘When using RNA interference (RNAi) to study gene functions in Lepidoptera insects, we discovered that some genes could not be suppressed; instead, their expression levels could be up-regulated by double-stranded RNA (dsRNA). To predict which genes could be easily silenced, we treated the Asian corn borer (Ostriniafilrnacalis) with dsGFP (green fluorescent protein) and dsMLP (muscle lim protein). A transcriptome sequence analysis was conducted using the cDNAs 6 h after treatment with dsRNA. The results indicated that 160 genes were up-regulated and 44 genes were down-regulated by the two dsRNAs. Then, 50 co-up-regulated, 25 co-down-regulated and 43 unaffected genes were selected to determine their RNAi responses. All the 25 down-regulated genes were knocked down by their corresponding dsRNA. However, several of the up-regulated and unaffected genes were up-regulated when treated with their corresponding dsRNAs instead of being knocked down. The genes up-regulated by the dsGFP treatment may be involved in insect immune responses or the RNAi pathway. When the immune-related genes were excluded, only seven genes were induced by dsGFP, including ago-2 and dicer-2. These results not only provide a reference for efficient RNAi target predications, but also provide some potential RNAi pathway-related genes for further study.
基金supported by the National Defense Pre-Research Foundation of China(Grant No.9140C500108140C50225)Shanghai Science and Technology Committee Innovation(Grant Nos.17JC1400600 and 17JC1400601)Open Foundation of Jiangsu Province Key Laboratory of High-end Structure Materials(Grant No.hsm1905).
文摘Four Zn-rich Al-Zn-Mg-Cu alloys with different Mg and Cu contents were fabricated by spray deposition.The effects of Mg and Cu contents on the aging behaviors of the whole precipitation process of the alloys were systematically investigated.The results show that the primary precipitates in the under-aged and peak-aged alloys are GPⅡ and η'phases;no GPⅠ zones were observed.During aging,the dissolution driving force of the precipitates increases with increasing Mg content;therefore,the volume fraction of precipitates in the grain interior and the area fraction of precipitates at the grain boundary increase obviously,which contributes to a considerable improvement in yield strength and decrease in plasticity of the high Mg content alloys.Cu content has no apparent effect on the size and volume fraction of precipitates.However,a higher Cu content can effectively prevent coarsening and transformation of precipitates,which is beneficial to maintain the peak aging state of the alloys.This research provides a basis for the composition optimization of the rapid-solidified highly alloying Al-Zn-Mg-Cu alloys.
基金supported by the grants from the Taishan Scholars Program for Young Expert of Shandong Province(Grant no.tsqn20161064)National Natural Science Foundation of China(Grant nos.82073200 and 81874178)funds for Independent Cultivation of Innovative Team from Universities in Jinan(Grant no.2020GXRC023).
文摘Background and Aims:Previous meta-analyses have shown that aspirin use may reduce the risk of hepatocellular carcinoma(HCC).However,the optimal dose,frequency,and duration of aspirin use or the safety and efficacy of aspirin in target populations for HCC prevention remain unclear.The study aim was to investigate the efficacy and safety of aspirin for prevention of HCC.Methods:Publications were retrieved by a comprehensive literature research of several databases.Based on a random-effects model,hazard ratios(HRs)and the corresponding 95%confidence intervals(CIs)were used to assess the pooled risk.The dose-response relationship between aspirin use and HCC risk was assessed with a restricted cubic spline model.Results:Twenty-two studies were included in the metaanalysis.Aspirin use was associated with a reduced risk of HCC(HR=0.64,95%CI:0.56–0.75).The effect was robust across sex and age;however,women and the non-elderly had the greatest benefit from aspirin use.The preventive effect was well reproduced in those with comorbidities.Daily use and long-term use of aspirin appeared to offer greater benefits.Aspirin 100 mg/d was associated with maximum reduction of HCC risk.Aspirin use did slightly increase the risk of bleeding(HR=1.14,95%CI:1.02–1.27).Conclusions:Our meta-analysis confirmed that use of aspirin significantly reduced the incident risk of HCC.Regular and long-term aspirin use offers a greater advantage.Aspirin use was associated with an increased risk of bleeding.We recommend 100 mg/d aspirin as a feasible dose for further research on primary prevention of HCC in a broad at-risk population.