Initiating explosive devices(IEDs)are crucial in both military and civilian applications for improving the accuracy of controlled detonations.However,the safety of semiconductor bridge(SCB)wire IEDs,which are the most...Initiating explosive devices(IEDs)are crucial in both military and civilian applications for improving the accuracy of controlled detonations.However,the safety of semiconductor bridge(SCB)wire IEDs,which are the most widely used,is increasingly threatened by complex electromagnetic environments.Although protective devices such as thermistors and zener diodes are commonly employed to enhance safety,traditional discrete components can compromise compactness and provide only marginal improvements.The metal-insulator transition properties of vanadium dioxide(VO_(2))present an innovative approach to enhancing the safety performance of IEDs.Nevertheless,the functional relevance of the VO_(2) phase transition in relation to IEDs has garnered limited scientific attention.The VO_(2) film fabricated via 3D printing demonstrated resistivity modulation ranging from 2 to 5 orders of magnitude,achieving a stable metallic-state resistance of 1.2Ω.The results show that this process increases the 5-min safe current threshold by 90%,from 1 A to 1.9 A,and reduces the temperature generated by the current by approximately 40%when below the safe current threshold.Integrating VO_(2) film into IEDs via semiconductor processes significantly enhances safety performance while maintaining detonation capability,demonstrating its effectiveness as a safety modulator in pyrotechnic engineering.展开更多
Concerning the issue of high-dimensions and low-failure probabilities including implicit and highly nonlinear limit state function, reliability analysis based on the directional importance sampling in combination with...Concerning the issue of high-dimensions and low-failure probabilities including implicit and highly nonlinear limit state function, reliability analysis based on the directional importance sampling in combination with the radial basis function （RBF） neural network is used, and the RBF neural network based on first-order reliability method （FORM） is to approximate the unknown implicit limit state functions and calculate the most probable point （MPP） with iterative algorithm. For good efficiency, based on the ideas that directional sampling reduces dimensionality and importance sampling focuses on the domain contributing to failure probability, the joint probability density function of importance sampling is constructed, and the sampling center is moved to MPP to ensure that more random sample points draw belong to the failure domain and the simulation efficiency is improved. Then the numerical example of initiating explosive devices for rocket booster explosive bolts demonstrates the applicability, versatility and accuracy of the approach compared with other reliability simulation algorithm.展开更多
Powder compaction is one of the most crucial processes in initiating explosive device manufacturing. The quality of powder compaction may influence the performances of product directly. Traditional powder compaction m...Powder compaction is one of the most crucial processes in initiating explosive device manufacturing. The quality of powder compaction may influence the performances of product directly. Traditional powder compaction mainly makes use of manual gravitational spiral loading machine or lever loading machine. Potential accident by the strike in powder compaction of initiating explosive device could risk life, property and the environment. To prevent this risk, automatic control system and control strategy can be used to guarantee no strike in pressing process. The scope of this paper is to analyze and review the control strategy for powder compact and discuss the experimental results for the application of the proposed strategy.展开更多
Emerging evidence points to the existence of pan-creatic cancer stem cells (CSC) as the culprit in the initiation, maintenance, metastasis, and treatment resistance of pancreatic cancer. The existence of such a cell p...Emerging evidence points to the existence of pan-creatic cancer stem cells (CSC) as the culprit in the initiation, maintenance, metastasis, and treatment resistance of pancreatic cancer. The existence of such a cell population would have an important im-pact on the design of novel therapies against this devastating disease. However, no in vivo validation or rebuttal of the pancreatic CSC hypothesis exists. Major backlashes in the discussion on CSC are firstly, the confusion between the terms CSC and cell of origin of pancreatic ductal adenocarcinoma (PDAC), secondly the ambiguity of the cell of origin itself and thirdly, the fact that the CSC hypothesis is based on cell sorting and xenografting experiments; the latter of which often precludes solid conclusions because of the lack of a natural microenvironment and differences in drug delivery. Nonetheless, recent studies in other cancers partially support the CSC hypothesis by demonstrating a link between epithelial-to-mesenchymal transdifferentiation/transition (EMT) and CSC properties. Such a link is again open to dispute as EMT is a reversible process which is highly dependent on major oncogenic pathways in PDAC [e.g. K-Ras, transforming growth factor-β (TGF-β)] rather than on presumed cancer stem cell pathways. Hence, the available evidence does not robustly support the CSC concept in PDAC and a thorough validation of this hypothesis in well-defined genetically engineered mouse models of pancreatic cancer is required.展开更多
The delay arming process of initiating explosive （ IE ） brakes for fuse is complex and hard to be verified. A numerical simulation model of IE brakes was established based on the arbitrary La- grange-Euler method. T...The delay arming process of initiating explosive （ IE ） brakes for fuse is complex and hard to be verified. A numerical simulation model of IE brakes was established based on the arbitrary La- grange-Euler method. The model included the structure, the air filed, etc. The simulation boundary conditions were defined, including the contacts, blasting parameters of the explosive and the fluid- solid coupling interface. The simulation results show that the shear pin of the chosen IE can be cut off. When the piston needs to move 0.8 cm, the time set to the delay arming of the IE brakes model is about 40μS. The maximum displacement of the piston is 1. 17 cm. The model provides basis for parameters design and further improvement of IE brakes.展开更多
The dielectric barrier discharge(DBD)is presently used in many fields,in eluding plasma medicine,surface modification,and ozone synthesis;the influe nee of airflow on the DBD is a widely investigated topic.In this wor...The dielectric barrier discharge(DBD)is presently used in many fields,in eluding plasma medicine,surface modification,and ozone synthesis;the influe nee of airflow on the DBD is a widely investigated topic.In this work,a hysteresis characteristic on the initiating and extinguishing boundaries is observed in a nanosecond pulsed DBD,which is sensitive to the variation in the airflow velocities and pulse repetition frequencies(PRFs).It is found that,at a certain airflow velocity,the initiating PRF is higher than the extinguishing PRF.This differenee between the initiating PRF and the extinguishing PRF leads to a hysteresis phenomenon on the initiating and extinguishing boun daries.When the airflow velocity is in creased,both the initiating and extinguishing PRFs are increased and the differenee between the initiating PRF and the extinguishing PRF also increased.The hysteresis width between the initiating and extinguishing boundaries is enhanced.To explain these results,the physical processes involved with the seed particles and the mechanisms of forming discharge channels are discussed.展开更多
Various applications of volume dielectric barrier discharges(DBDs)with airflows have attracted significant attention such as in the fields of plasma medicine,surface modification,ozone synthesis,etc.In this work,the n...Various applications of volume dielectric barrier discharges(DBDs)with airflows have attracted significant attention such as in the fields of plasma medicine,surface modification,ozone synthesis,etc.In this work,the nonlinearity characteristics of DBDs in initiating and extinguishing boundaries with airflows are experimentally investigated.It is found that the difference between initiating pulse repetition frequencies(PRFs)and extinguishing PRFs is affected by the addition of airflows.A hysteresis region is produced between these two PRFs.A topological rule of Thom's classification theorem is proposed to investigate the hysteresis phenomenon of discharges with airflows.It is concluded that the discharge state is dependent on the operation route.The discharge state would transit from initiating to extinguishing,or in the opposite direction,while passing along a specific operation route.Based on the topological method,two nonlinear laws of discharge structure transition under the typical operation routes are predicted and verified in the discharge experiments.展开更多
The amount of information required for reliability assessment of success/failure products is defined and the formula of equivalent information method is deduced. Based on the formula, a method for assessing reliabilit...The amount of information required for reliability assessment of success/failure products is defined and the formula of equivalent information method is deduced. Based on the formula, a method for assessing reliability of initiating explosive devices with small sample size is established. Compared with the assessment method for devices with large sample size, the new method is correct and feasible and can be used to assess the reliability of initiating explosive devices with high reliability requirements.展开更多
Based on the analysis of weakness on the safety of traditional electric detonators, a BJ-l safety electric detonator initiatingsystem and its corresponding safe examination technique were successfully developed. By le...Based on the analysis of weakness on the safety of traditional electric detonators, a BJ-l safety electric detonator initiatingsystem and its corresponding safe examination technique were successfully developed. By leading false foot wires and taking advantageof the transmitting frequency band of Mo-Zn ferrite, detonators in this new system can completely impede the direct induction of outsidecrosstalk that may cause casual firing in the ordinary as well as eleclromagnetic ones. Possible causality by lightning was discussed. Results are presented, of its safety tests on resistance to direct and alternating current, electrostatic, and crosstalk induced by damp leakagein saturated salty water.展开更多
The past 40 years has seen the remarkable history of the building of not only socialism with Chinese characteristics but also a moderately prosperous society by the Chinese people led by the Communist Party of China.B...The past 40 years has seen the remarkable history of the building of not only socialism with Chinese characteristics but also a moderately prosperous society by the Chinese people led by the Communist Party of China.By 2020,China will have finished building a moderately prosperous society in all respects and realized the second strategic objective of the rejuvenation of the Chinese nation.展开更多
With the development of intelligent and flexible manufacturing, the traditional mechanical press can not meet the needs of the future processing industry because it is difficult to achieve variable speed adjustment an...With the development of intelligent and flexible manufacturing, the traditional mechanical press can not meet the needs of the future processing industry because it is difficult to achieve variable speed adjustment and change the motion characteristics. Servo press is directly driven by servo motor to realize the flexible control of pressure movement, which has become the development trend of the industry in the future. The independent research and development of servo press control system has become the research hotspot and difficulty of the domestic press industry. In this paper, the servo press control system used for initiating explosive device pressing is studied and analyzed for reference.展开更多
In the field of initiating explosive device assembly, it is necessary to continuously optimize the automation system to ensure that various safety indicators of initiating explosive device assembly equipment can meet ...In the field of initiating explosive device assembly, it is necessary to continuously optimize the automation system to ensure that various safety indicators of initiating explosive device assembly equipment can meet the needs of safety management. We analyzed the safety control principle of safety automation of initiating explosive device assembly, and put forward the safety control measures.展开更多
The selective cationic polymerization of isobutylene （IB） initiated by a BF3-cyclohexanol （CL） complex was carried out from the mixed Ca fraction feed containing the 4C saturated and unsaturated hydrocarbons at -2...The selective cationic polymerization of isobutylene （IB） initiated by a BF3-cyclohexanol （CL） complex was carried out from the mixed Ca fraction feed containing the 4C saturated and unsaturated hydrocarbons at -20℃. The effects of CL concentration, BF3 concentration, solvent for preparing BF3·CL complex and polymerization time on the chemical structure of end groups, number-average molecular weight （Mn） and molecular weight distribution （MWD, Mw/Mn） of the resulting polymers were investigated. The experimental results indicate that the BF3·CL complex initiating system exhibited an extremely high selectivity toward the cationic polymerization of IB in the mixed C4 fraction feed and low molecular weight （Mn = 900-3600） polyisobutylenes （PIBs） with large proportion of exo-double bond end groups were obtained. The exo-double bond content in PIB chain ends increased by increasing CL concentration or by decreasing solvent polarity in initiating system, BF3 concentration and polymerization time. The M, and MWD of the resulting PIBs were dependent on the concentrations of CL and BF3. Highly reactive PIBs with around 90 mol% of exo-double bonds were successfully synthesized by the selective polymerization of IB from the mixed Ca fraction feed, providing a potentially practical process for its simplicity and low costs.展开更多
AIM To explore primary care physicians' perspectives on possible barriers to the use of insulin.METHODS This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Me...AIM To explore primary care physicians' perspectives on possible barriers to the use of insulin.METHODS This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Eight electronic databases were searched(between January 1, 1994 and August 31, 2014) for relevant studies. A search for grey literature and a review of the references in the retrieved studies were also conducted. Studies that focused on healthcare providers' perspectives on possible barriers to insulin initiation with type 2 diabetic patients were included, as well as articles suggesting solutions for these barriers. Review articles and studies that only considered patients' perspectives were excluded. RESULTS A total of 19 studies met the inclusion criteria and were therefore included in this study: 10 of these studies used qualitative methods, 8 used quantitative methods and 1 used mixed methods. Studies included a range of different health care settings. The findings are reported under four broad categories: The perceptions of primary care physicians about the barriers to initiate insulin therapy for type 2 diabetes patients, how primary care physicians assess patients prior to initiating insulin, professional roles and possible solutions to overcome these barriers. The barriers described were many and covered doctor, patient, system and technological aspects. Interventions that focused on doctor training and support, or IT-based decision support were few, and did not result in significant improvement. CONCLUSION Primary care physicians' known delay in insulin initiation is multifactorial. Published reports of attempts to find solutions for these barriers were limited in number.展开更多
Conceived as countering market outcomes,British planning focuses on the development and design of land use and the built environment,with a close relationship with the economy.The public and politicians in the UK ofte...Conceived as countering market outcomes,British planning focuses on the development and design of land use and the built environment,with a close relationship with the economy.The public and politicians in the UK often associate planning with rigorous regulations that prevent economic growth,and many stakeholders complain about the restrictions that planning puts on their autonomous activities.To explore this,this essay focuses on the definition and the nature of ‘inhibit’,‘regulate’,‘guide’ and ‘initiate’ features through the plan-making process and management in England,finding out a more proactive role for planning as guiding and initiating development.展开更多
Context: Antiretroviral therapies improve the prognosis of NeuroAIDS contrasting with a high frequency of Minor Neurocognitive Disorders (MND) even in aviremic subjects. Objective: The objective of this study is to pr...Context: Antiretroviral therapies improve the prognosis of NeuroAIDS contrasting with a high frequency of Minor Neurocognitive Disorders (MND) even in aviremic subjects. Objective: The objective of this study is to present the neurological and cognitive profile of People Living with HIV (PLHIV) initiating antiretroviral treatment in Kinshasa in the era of Dolutegravir (DTG). Methods: This is a multicenter, cross-sectional study with a descriptive aim carried out in 16 HIV Outpatient Treatment Centers (OTC) in Kinshasa from October 4, 2021 to February 15, 2022. The International HIV Dementia Scale (IHDS) correlated with the Activities of Daily Living (IADL) scale facilitated the categorization of NeuroCognitive Disorders (NCD) of PLHIV evaluated after carrying out a summary neurological examination. Results: Of the 96 patients recruited, 56.3% were women with a sex ratio of 0.68. The average age was 40.1 ± 12.1 years. The secondary education level was the majority at 64.6%. Malaria (44.8%) and tuberculosis (32.3%) were more common as opportunistic infections. They were alcoholics in (30.2%). Their history was heart disease (15.6%), high blood pressure (18.8%);drug abuse (10.4%). The IHDS score was light in 55.2% of cases. The correlation between IHDS/IADL watches asymptomatic neurocognitive impairments (ANI) in 77.1%, almost all of subjects are found with normal overall functioning (94.8%) and a disturbed neurological examination in 53.1% of cases with a predominance of motor impairments in 79.1%. Conclusion: In view of these results, early and systematic screening of NCD and associated factors remains necessary in our context. .展开更多
Objective To compare evaluations of depressive episodes and suggested treatment protocols generated by Chat Generative Pretrained Transformer(ChatGPT)-3 and ChatGPT-4 with the recommendations of primary care physician...Objective To compare evaluations of depressive episodes and suggested treatment protocols generated by Chat Generative Pretrained Transformer(ChatGPT)-3 and ChatGPT-4 with the recommendations of primary care physicians.Methods Vignettes were input to the ChatGPT interface.These vignettes focused primarily on hypothetical patients with symptoms of depression during initial consultations.The creators of these vignettes meticulously designed eight distinct versions in which they systematically varied patient attributes(sex,socioeconomic status(blue collar worker or white collar worker)and depression severity(mild or severe)).Each variant was subsequently introduced into ChatGPT-3.5 and ChatGPT-4.Each vignette was repeated 10 times to ensure consistency and reliability of the ChatGPT responses.Results For mild depression,ChatGPT-3.5 and ChatGPT-4 recommended psychotherapy in 95.0%and 97.5%of cases,respectively.Primary care physicians,however,recommended psychotherapy in only 4.3%of cases.For severe cases,ChatGPT favoured an approach that combined psychotherapy,while primary care physicians recommended a combined approach.The pharmacological recommendations of ChatGPT-3.5 and ChatGPT-4 showed a preference for exclusive use of antidepressants(74%and 68%,respectively),in contrast with primary care physicians,who typically recommended a mix of antidepressants and anxiolytics/hypnotics(67.4%).Unlike primary care physicians,ChatGPT showed no gender or socioeconomic biases in its recommendations.Conclusion ChatGPT-3.5 and ChatGPT-4 aligned well with accepted guidelines for managing mild and severe depression,without showing the gender or socioeconomic biases observed among primary care physicians.Despite the suggested potential benefit of using atificial intelligence(AI)chatbots like ChatGPT to enhance clinical decision making,further research is needed to refine AI recommendations for severe cases and to consider potential risks and ethical issues.展开更多
A successful tissue regeneration is a very complex process that requires a precise coordination of many molecular,cellular and physiological events.One of the critical steps is to convert the injury signals into regen...A successful tissue regeneration is a very complex process that requires a precise coordination of many molecular,cellular and physiological events.One of the critical steps is to convert the injury signals into regeneration signals to initiate tissue regeneration.Although many efforts have been made to investigate the mechanisms triggering tissue regeneration,the fundamental questions remain unresolved.One of the major obstacles is that the injury and the initiation of regeneration are two highly coupled processes and hard to separate from one another.In this article,we review the major events occurring at the early injury/regeneration stage in a range of species,and discuss the possible common mechanisms during initiation of tissue regeneration.展开更多
As tumor PD-L1 provides signals to anti-tumor PD-1^(+)T cells that blunt their functions,αPD-1 andαPD-L1 antibodies have been developed as anti-cancer immunotherapies based on interrupting this signaling axis.Howeve...As tumor PD-L1 provides signals to anti-tumor PD-1^(+)T cells that blunt their functions,αPD-1 andαPD-L1 antibodies have been developed as anti-cancer immunotherapies based on interrupting this signaling axis.However,tumor cell-intrinsic PD-L1 signals also regulate immune-independent tumor cell proliferation and mTOR signals,among other important effects.Tumor-initiating cells(TICs)generate carcinomas,resist treatments and promote relapse.We show here that in murine B16 melanoma and ID8agg ovarian carcinoma cells,TICs express more PD-L1 versus non-TICs.Silencing PD-L1 in B16 and ID8agg cells by shRNA(‘PD-L1lo’)reduced TIC numbers,the canonical TIC genes nanog and pou5f1(oct4),and functions as assessed by tumorosphere development,immune-dependent and immune-independent tumorigenesis,and serial transplantability in vivo.Strikingly,tumor PD-L1 sensitized TIC to interferon-γand rapamycin in vitro.Cell-intrinsic PD-L1 similarly drove functional TIC generation,canonical TIC gene expression and sensitivity to interferon-γand rapamycin in human ES2 ovarian cancer cells.Thus,tumor-intrinsic PD-L1 signals promote TIC generation and virulence,possibly by promoting canonical TIC gene expression,suggesting that PD-L1 has novel signaling effects on cancer pathogenesis and treatment responses.展开更多
Nature|大型汉族人群队列助力中国台湾精准医疗精准医学的发展依赖于大规模、具有深度表型和基因变异图谱数据的人群队列,然而这在非欧洲人群中数据仍严重不足。中国台湾精准医学计划(Taiwan Precision Medicine Initiative,TPMI)旨在...Nature|大型汉族人群队列助力中国台湾精准医疗精准医学的发展依赖于大规模、具有深度表型和基因变异图谱数据的人群队列,然而这在非欧洲人群中数据仍严重不足。中国台湾精准医学计划(Taiwan Precision Medicine Initiative,TPMI)旨在建立一个具有广泛代表性的中国台湾汉族人群队列,以支持大规模基因组与健康医学研究(2025年10月15日在线发表,doi:10.1038/s41586-025-09680-x)。展开更多
文摘Initiating explosive devices(IEDs)are crucial in both military and civilian applications for improving the accuracy of controlled detonations.However,the safety of semiconductor bridge(SCB)wire IEDs,which are the most widely used,is increasingly threatened by complex electromagnetic environments.Although protective devices such as thermistors and zener diodes are commonly employed to enhance safety,traditional discrete components can compromise compactness and provide only marginal improvements.The metal-insulator transition properties of vanadium dioxide(VO_(2))present an innovative approach to enhancing the safety performance of IEDs.Nevertheless,the functional relevance of the VO_(2) phase transition in relation to IEDs has garnered limited scientific attention.The VO_(2) film fabricated via 3D printing demonstrated resistivity modulation ranging from 2 to 5 orders of magnitude,achieving a stable metallic-state resistance of 1.2Ω.The results show that this process increases the 5-min safe current threshold by 90%,from 1 A to 1.9 A,and reduces the temperature generated by the current by approximately 40%when below the safe current threshold.Integrating VO_(2) film into IEDs via semiconductor processes significantly enhances safety performance while maintaining detonation capability,demonstrating its effectiveness as a safety modulator in pyrotechnic engineering.
文摘Concerning the issue of high-dimensions and low-failure probabilities including implicit and highly nonlinear limit state function, reliability analysis based on the directional importance sampling in combination with the radial basis function （RBF） neural network is used, and the RBF neural network based on first-order reliability method （FORM） is to approximate the unknown implicit limit state functions and calculate the most probable point （MPP） with iterative algorithm. For good efficiency, based on the ideas that directional sampling reduces dimensionality and importance sampling focuses on the domain contributing to failure probability, the joint probability density function of importance sampling is constructed, and the sampling center is moved to MPP to ensure that more random sample points draw belong to the failure domain and the simulation efficiency is improved. Then the numerical example of initiating explosive devices for rocket booster explosive bolts demonstrates the applicability, versatility and accuracy of the approach compared with other reliability simulation algorithm.
文摘Powder compaction is one of the most crucial processes in initiating explosive device manufacturing. The quality of powder compaction may influence the performances of product directly. Traditional powder compaction mainly makes use of manual gravitational spiral loading machine or lever loading machine. Potential accident by the strike in powder compaction of initiating explosive device could risk life, property and the environment. To prevent this risk, automatic control system and control strategy can be used to guarantee no strike in pressing process. The scope of this paper is to analyze and review the control strategy for powder compact and discuss the experimental results for the application of the proposed strategy.
文摘Emerging evidence points to the existence of pan-creatic cancer stem cells (CSC) as the culprit in the initiation, maintenance, metastasis, and treatment resistance of pancreatic cancer. The existence of such a cell population would have an important im-pact on the design of novel therapies against this devastating disease. However, no in vivo validation or rebuttal of the pancreatic CSC hypothesis exists. Major backlashes in the discussion on CSC are firstly, the confusion between the terms CSC and cell of origin of pancreatic ductal adenocarcinoma (PDAC), secondly the ambiguity of the cell of origin itself and thirdly, the fact that the CSC hypothesis is based on cell sorting and xenografting experiments; the latter of which often precludes solid conclusions because of the lack of a natural microenvironment and differences in drug delivery. Nonetheless, recent studies in other cancers partially support the CSC hypothesis by demonstrating a link between epithelial-to-mesenchymal transdifferentiation/transition (EMT) and CSC properties. Such a link is again open to dispute as EMT is a reversible process which is highly dependent on major oncogenic pathways in PDAC [e.g. K-Ras, transforming growth factor-β (TGF-β)] rather than on presumed cancer stem cell pathways. Hence, the available evidence does not robustly support the CSC concept in PDAC and a thorough validation of this hypothesis in well-defined genetically engineered mouse models of pancreatic cancer is required.
基金Supported by the National Natural Science Foundation of China(11372047)
文摘The delay arming process of initiating explosive （ IE ） brakes for fuse is complex and hard to be verified. A numerical simulation model of IE brakes was established based on the arbitrary La- grange-Euler method. The model included the structure, the air filed, etc. The simulation boundary conditions were defined, including the contacts, blasting parameters of the explosive and the fluid- solid coupling interface. The simulation results show that the shear pin of the chosen IE can be cut off. When the piston needs to move 0.8 cm, the time set to the delay arming of the IE brakes model is about 40μS. The maximum displacement of the piston is 1. 17 cm. The model provides basis for parameters design and further improvement of IE brakes.
文摘The dielectric barrier discharge(DBD)is presently used in many fields,in eluding plasma medicine,surface modification,and ozone synthesis;the influe nee of airflow on the DBD is a widely investigated topic.In this work,a hysteresis characteristic on the initiating and extinguishing boundaries is observed in a nanosecond pulsed DBD,which is sensitive to the variation in the airflow velocities and pulse repetition frequencies(PRFs).It is found that,at a certain airflow velocity,the initiating PRF is higher than the extinguishing PRF.This differenee between the initiating PRF and the extinguishing PRF leads to a hysteresis phenomenon on the initiating and extinguishing boun daries.When the airflow velocity is in creased,both the initiating and extinguishing PRFs are increased and the differenee between the initiating PRF and the extinguishing PRF also increased.The hysteresis width between the initiating and extinguishing boundaries is enhanced.To explain these results,the physical processes involved with the seed particles and the mechanisms of forming discharge channels are discussed.
基金supported by National Natural Science Foundation of China(Nos.51676053 and 91741204)。
文摘Various applications of volume dielectric barrier discharges(DBDs)with airflows have attracted significant attention such as in the fields of plasma medicine,surface modification,ozone synthesis,etc.In this work,the nonlinearity characteristics of DBDs in initiating and extinguishing boundaries with airflows are experimentally investigated.It is found that the difference between initiating pulse repetition frequencies(PRFs)and extinguishing PRFs is affected by the addition of airflows.A hysteresis region is produced between these two PRFs.A topological rule of Thom's classification theorem is proposed to investigate the hysteresis phenomenon of discharges with airflows.It is concluded that the discharge state is dependent on the operation route.The discharge state would transit from initiating to extinguishing,or in the opposite direction,while passing along a specific operation route.Based on the topological method,two nonlinear laws of discharge structure transition under the typical operation routes are predicted and verified in the discharge experiments.
基金Supported by the Ministerial Level Foundation(9140C3705041003)
文摘The amount of information required for reliability assessment of success/failure products is defined and the formula of equivalent information method is deduced. Based on the formula, a method for assessing reliability of initiating explosive devices with small sample size is established. Compared with the assessment method for devices with large sample size, the new method is correct and feasible and can be used to assess the reliability of initiating explosive devices with high reliability requirements.
文摘Based on the analysis of weakness on the safety of traditional electric detonators, a BJ-l safety electric detonator initiatingsystem and its corresponding safe examination technique were successfully developed. By leading false foot wires and taking advantageof the transmitting frequency band of Mo-Zn ferrite, detonators in this new system can completely impede the direct induction of outsidecrosstalk that may cause casual firing in the ordinary as well as eleclromagnetic ones. Possible causality by lightning was discussed. Results are presented, of its safety tests on resistance to direct and alternating current, electrostatic, and crosstalk induced by damp leakagein saturated salty water.
文摘The past 40 years has seen the remarkable history of the building of not only socialism with Chinese characteristics but also a moderately prosperous society by the Chinese people led by the Communist Party of China.By 2020,China will have finished building a moderately prosperous society in all respects and realized the second strategic objective of the rejuvenation of the Chinese nation.
文摘With the development of intelligent and flexible manufacturing, the traditional mechanical press can not meet the needs of the future processing industry because it is difficult to achieve variable speed adjustment and change the motion characteristics. Servo press is directly driven by servo motor to realize the flexible control of pressure movement, which has become the development trend of the industry in the future. The independent research and development of servo press control system has become the research hotspot and difficulty of the domestic press industry. In this paper, the servo press control system used for initiating explosive device pressing is studied and analyzed for reference.
文摘In the field of initiating explosive device assembly, it is necessary to continuously optimize the automation system to ensure that various safety indicators of initiating explosive device assembly equipment can meet the needs of safety management. We analyzed the safety control principle of safety automation of initiating explosive device assembly, and put forward the safety control measures.
基金supported by the National Natural Science Foundation of China(Nos.20774008 and 20934001)Program for Changjiang Scholars and Innovative Research Teams in Universities(IRT 0706)
文摘The selective cationic polymerization of isobutylene （IB） initiated by a BF3-cyclohexanol （CL） complex was carried out from the mixed Ca fraction feed containing the 4C saturated and unsaturated hydrocarbons at -20℃. The effects of CL concentration, BF3 concentration, solvent for preparing BF3·CL complex and polymerization time on the chemical structure of end groups, number-average molecular weight （Mn） and molecular weight distribution （MWD, Mw/Mn） of the resulting polymers were investigated. The experimental results indicate that the BF3·CL complex initiating system exhibited an extremely high selectivity toward the cationic polymerization of IB in the mixed C4 fraction feed and low molecular weight （Mn = 900-3600） polyisobutylenes （PIBs） with large proportion of exo-double bond end groups were obtained. The exo-double bond content in PIB chain ends increased by increasing CL concentration or by decreasing solvent polarity in initiating system, BF3 concentration and polymerization time. The M, and MWD of the resulting PIBs were dependent on the concentrations of CL and BF3. Highly reactive PIBs with around 90 mol% of exo-double bonds were successfully synthesized by the selective polymerization of IB from the mixed Ca fraction feed, providing a potentially practical process for its simplicity and low costs.
文摘AIM To explore primary care physicians' perspectives on possible barriers to the use of insulin.METHODS This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Eight electronic databases were searched(between January 1, 1994 and August 31, 2014) for relevant studies. A search for grey literature and a review of the references in the retrieved studies were also conducted. Studies that focused on healthcare providers' perspectives on possible barriers to insulin initiation with type 2 diabetic patients were included, as well as articles suggesting solutions for these barriers. Review articles and studies that only considered patients' perspectives were excluded. RESULTS A total of 19 studies met the inclusion criteria and were therefore included in this study: 10 of these studies used qualitative methods, 8 used quantitative methods and 1 used mixed methods. Studies included a range of different health care settings. The findings are reported under four broad categories: The perceptions of primary care physicians about the barriers to initiate insulin therapy for type 2 diabetes patients, how primary care physicians assess patients prior to initiating insulin, professional roles and possible solutions to overcome these barriers. The barriers described were many and covered doctor, patient, system and technological aspects. Interventions that focused on doctor training and support, or IT-based decision support were few, and did not result in significant improvement. CONCLUSION Primary care physicians' known delay in insulin initiation is multifactorial. Published reports of attempts to find solutions for these barriers were limited in number.
文摘Conceived as countering market outcomes,British planning focuses on the development and design of land use and the built environment,with a close relationship with the economy.The public and politicians in the UK often associate planning with rigorous regulations that prevent economic growth,and many stakeholders complain about the restrictions that planning puts on their autonomous activities.To explore this,this essay focuses on the definition and the nature of ‘inhibit’,‘regulate’,‘guide’ and ‘initiate’ features through the plan-making process and management in England,finding out a more proactive role for planning as guiding and initiating development.
文摘Context: Antiretroviral therapies improve the prognosis of NeuroAIDS contrasting with a high frequency of Minor Neurocognitive Disorders (MND) even in aviremic subjects. Objective: The objective of this study is to present the neurological and cognitive profile of People Living with HIV (PLHIV) initiating antiretroviral treatment in Kinshasa in the era of Dolutegravir (DTG). Methods: This is a multicenter, cross-sectional study with a descriptive aim carried out in 16 HIV Outpatient Treatment Centers (OTC) in Kinshasa from October 4, 2021 to February 15, 2022. The International HIV Dementia Scale (IHDS) correlated with the Activities of Daily Living (IADL) scale facilitated the categorization of NeuroCognitive Disorders (NCD) of PLHIV evaluated after carrying out a summary neurological examination. Results: Of the 96 patients recruited, 56.3% were women with a sex ratio of 0.68. The average age was 40.1 ± 12.1 years. The secondary education level was the majority at 64.6%. Malaria (44.8%) and tuberculosis (32.3%) were more common as opportunistic infections. They were alcoholics in (30.2%). Their history was heart disease (15.6%), high blood pressure (18.8%);drug abuse (10.4%). The IHDS score was light in 55.2% of cases. The correlation between IHDS/IADL watches asymptomatic neurocognitive impairments (ANI) in 77.1%, almost all of subjects are found with normal overall functioning (94.8%) and a disturbed neurological examination in 53.1% of cases with a predominance of motor impairments in 79.1%. Conclusion: In view of these results, early and systematic screening of NCD and associated factors remains necessary in our context. .
文摘Objective To compare evaluations of depressive episodes and suggested treatment protocols generated by Chat Generative Pretrained Transformer(ChatGPT)-3 and ChatGPT-4 with the recommendations of primary care physicians.Methods Vignettes were input to the ChatGPT interface.These vignettes focused primarily on hypothetical patients with symptoms of depression during initial consultations.The creators of these vignettes meticulously designed eight distinct versions in which they systematically varied patient attributes(sex,socioeconomic status(blue collar worker or white collar worker)and depression severity(mild or severe)).Each variant was subsequently introduced into ChatGPT-3.5 and ChatGPT-4.Each vignette was repeated 10 times to ensure consistency and reliability of the ChatGPT responses.Results For mild depression,ChatGPT-3.5 and ChatGPT-4 recommended psychotherapy in 95.0%and 97.5%of cases,respectively.Primary care physicians,however,recommended psychotherapy in only 4.3%of cases.For severe cases,ChatGPT favoured an approach that combined psychotherapy,while primary care physicians recommended a combined approach.The pharmacological recommendations of ChatGPT-3.5 and ChatGPT-4 showed a preference for exclusive use of antidepressants(74%and 68%,respectively),in contrast with primary care physicians,who typically recommended a mix of antidepressants and anxiolytics/hypnotics(67.4%).Unlike primary care physicians,ChatGPT showed no gender or socioeconomic biases in its recommendations.Conclusion ChatGPT-3.5 and ChatGPT-4 aligned well with accepted guidelines for managing mild and severe depression,without showing the gender or socioeconomic biases observed among primary care physicians.Despite the suggested potential benefit of using atificial intelligence(AI)chatbots like ChatGPT to enhance clinical decision making,further research is needed to refine AI recommendations for severe cases and to consider potential risks and ethical issues.
基金Ji-Feng Fei was supported by the National Key R&D Program of China 2019YFE0106700the Natural Science Foundation of China 31970782,Project of Department of Education of Guangdong Province 2018KZDXM027+1 种基金Key-Area Research and Development Program of Guangdong Province 2018B030332001,2019B030335001Yanmei Liu was supported by the Natural Science Foundation of China 32070819,91854112,91750203.
文摘A successful tissue regeneration is a very complex process that requires a precise coordination of many molecular,cellular and physiological events.One of the critical steps is to convert the injury signals into regeneration signals to initiate tissue regeneration.Although many efforts have been made to investigate the mechanisms triggering tissue regeneration,the fundamental questions remain unresolved.One of the major obstacles is that the injury and the initiation of regeneration are two highly coupled processes and hard to separate from one another.In this article,we review the major events occurring at the early injury/regeneration stage in a range of species,and discuss the possible common mechanisms during initiation of tissue regeneration.
基金This work was supported by grants CA170491,CA054174 and CDMRP from The Holly Beach Public LibraryThe Owens Foundation,The Ovarian Cancer Research Fund Alliance,The Barker Foundation and the Skinner endowment to Tyler Curiel.
文摘As tumor PD-L1 provides signals to anti-tumor PD-1^(+)T cells that blunt their functions,αPD-1 andαPD-L1 antibodies have been developed as anti-cancer immunotherapies based on interrupting this signaling axis.However,tumor cell-intrinsic PD-L1 signals also regulate immune-independent tumor cell proliferation and mTOR signals,among other important effects.Tumor-initiating cells(TICs)generate carcinomas,resist treatments and promote relapse.We show here that in murine B16 melanoma and ID8agg ovarian carcinoma cells,TICs express more PD-L1 versus non-TICs.Silencing PD-L1 in B16 and ID8agg cells by shRNA(‘PD-L1lo’)reduced TIC numbers,the canonical TIC genes nanog and pou5f1(oct4),and functions as assessed by tumorosphere development,immune-dependent and immune-independent tumorigenesis,and serial transplantability in vivo.Strikingly,tumor PD-L1 sensitized TIC to interferon-γand rapamycin in vitro.Cell-intrinsic PD-L1 similarly drove functional TIC generation,canonical TIC gene expression and sensitivity to interferon-γand rapamycin in human ES2 ovarian cancer cells.Thus,tumor-intrinsic PD-L1 signals promote TIC generation and virulence,possibly by promoting canonical TIC gene expression,suggesting that PD-L1 has novel signaling effects on cancer pathogenesis and treatment responses.
文摘Nature|大型汉族人群队列助力中国台湾精准医疗精准医学的发展依赖于大规模、具有深度表型和基因变异图谱数据的人群队列,然而这在非欧洲人群中数据仍严重不足。中国台湾精准医学计划(Taiwan Precision Medicine Initiative,TPMI)旨在建立一个具有广泛代表性的中国台湾汉族人群队列,以支持大规模基因组与健康医学研究(2025年10月15日在线发表,doi:10.1038/s41586-025-09680-x)。
