The Poisson point process(PPP) has been widely used in wireless network modeling and performance analysis due to the independence between its nodes. Therefore, it may not be a suitable model for many of the exclusive ...The Poisson point process(PPP) has been widely used in wireless network modeling and performance analysis due to the independence between its nodes. Therefore, it may not be a suitable model for many of the exclusive networks between the nodes. This paper analyzes the energy efficiency(EE) and optimizes the two-tier heterogeneous cellular networks(Het Nets). Considering the mutual exclusion between macro base stations(MBSs) distribution, the deployment of MBSs is modeled by the Matérn hard-core point process(MHCPP), and the deployment of pico base stations(PBSs) is modeled by the PPP. We adopt a simple approximation method to study the signal to interference ratio(SIR) distribution in two-tier MHCPP-PPP networks and then derive the coverage probabilities, the average data rates and the energy efficiency of Het Nets. Finally, an optimization algorithm is proposed to improve the EE of Het Nets by controlling the transmit power of PBSs. The simulation results show that the EE of a system can be effectively improved by selecting the appropriate transmit power for the PBSs. In addition, two-tier MHCPP-PPP Het Nets have higher energy efficiency than two-tier PPP-PPP Het Nets.展开更多
Background:In-feed antibiotics are being phased out in livestock production worldwide.Alternatives to antibiotics are urgently needed to maintain animal health and production performance.Host defense peptides(HDPs)are...Background:In-feed antibiotics are being phased out in livestock production worldwide.Alternatives to antibiotics are urgently needed to maintain animal health and production performance.Host defense peptides(HDPs)are known for their broad-spectrum antimicrobial and immunomodulatory capabilities.Enhancing the synthesis of endogenous HDPs represents a promising antibiotic alternative strategy to disease control and prevention.Methods:To identify natural products with an ability to stimulate the synthesis of endogenous HDPs,we performed a high-throughput screening of 1261 natural products using a newly-established stable luciferase reporter cell line known as IPEC-J2/pBD3-luc.The ability of the hit compounds to induce HDP genes in porcine IPEC-J2 intestinal epithelial cells,3D4/31 macrophages,and jejunal explants were verified using RT-qPCR.Augmentation of the antibacterial activity of porcine 3D4/31 macrophages against a Gram-negative bacterium(enterotoxigenic E.coli)and a Gram-positive bacterium(Staphylococcus aureus)were further confirmed with four selected HDP-inducing compounds.Results:A total of 48 natural products with a minimum Z-score of 2.0 were identified after high-throughput screening,with 21 compounds giving at least 2-fold increase in luciferase activity in a follow-up dose-response experiment.Xanthohumol and deoxyshikonin were further found to be the most potent in inducing pBD3 mRNA expression,showing a minimum 10-fold increase in IPEC-J2,3D4/31 cells,and jejunal explants.Other compounds such as isorhapontigenin and calycosin also enhanced pBD3 mRNA expression by at least 10-fold in both IPEC-J2 cells and jejunal explants,but not 3D4/31 cells.In addition to pBD3,other porcine HDP genes such as pBD2,PG1-5,and pEP2C were induced to different magnitudes by xanthohumol,deoxyshikonin,isorhapontigenin,and calycosin,although clear gene-and cell type-specific patterns of regulation were observed.Desirably,these four compounds had a minimum effect on the expression of several representative inflammatory cytokine genes.Furthermore,when used at HDP-inducing concentrations,these compounds showed no obvious direct antibacterial activity,but significantly augmented the antibacterial activity of 3D4/31 macrophages(P<0.05)against both Gram-negative and Gram-positive bacteria.Conclusions:Our results indicate that these newly-identified natural HDP-inducing compounds have the potential to be developed as novel alternatives to antibiotics for prophylactic and therapeutic treatment of infectious diseases in livestock production.展开更多
With the development of society and the progress of technology,more and more ocean activities are carried out.It results in booming of deep-sea diving.The use of helium-oxygen mixture(as a kind of breathing gas)solves...With the development of society and the progress of technology,more and more ocean activities are carried out.It results in booming of deep-sea diving.The use of helium-oxygen mixture(as a kind of breathing gas)solves the physiological problems of divers in saturated diving,but it brings about the Heliumspeech voice communication problem,the drop of speech intelligibility.There is no doubt that the effective speech communication must be provided for supporting the life and work of divers in deep-sea.This paper describes the mechanism of forming heliumspeech,discusses the effects of pressure and helium environment on the speech spectrum,compares the pros and cons of the time-domain and frequency-domain unscrambling techniques,shows the challenges in heliumspeech communications.Finally,it briefly introduces the deep learning,and points out that deep learning/machine learning may be a perfectly unscrambling technique.展开更多
Background: This study aimed to illustrate the prevalence of CHD by screening children in extremely high-altitudeareas (over 4000 m to even 5000 m above sea level) and explore an aid model for early diagnosis and trea...Background: This study aimed to illustrate the prevalence of CHD by screening children in extremely high-altitudeareas (over 4000 m to even 5000 m above sea level) and explore an aid model for early diagnosis and treatmentfor the Tibetan population. Methods: A total of 2242 students from different schools in Ngamring County,Xigaze City, Tibet from September 2019 to September 2020 were selected for screening. The students were examinedthrough the inquiry of their current medical history and family history, cardiac auscultation and a physicalexamination, in order to screen out the suspected cases of CHD, and then the suspected cases were confirmed bycardiac color ultrasound examinations. After that, positive patients were be transferred to Shandong Province forfree treatment. Results: The prevalence of CHD among children in Ngamring County was 3.70% (83 cases),which is the highest incidence rate ever reported. The most common type of CHD was patent ductus arteriosus(PDA), accounting for 55.42% of the total number of cases screened, followed by atrial septal defect (ASD) andventricular septal defect (VSD), accounting for 28.92% and 12.05%, respectively. The prevalence of CHD in childrenat high altitude was significantly higher than that in children at low altitude. The children with CHD weretransferred to Shandong Province for surgery, the operations were successful and their recoveries went well.Conclusions: The results show that high altitude is closely related to the prevalence of CHD, and the incidencein Ngamring County is much higher than that in previous reports.展开更多
In this paper, we investigate a joint beamforming and time switching(TS) design for an energy-constrained cognitive two-way relay(TWR) network. In the network, the energy-constrained secondary user(SU) relay employs T...In this paper, we investigate a joint beamforming and time switching(TS) design for an energy-constrained cognitive two-way relay(TWR) network. In the network, the energy-constrained secondary user(SU) relay employs TS protocol to harvest energy from the signals sent by the circuit-powered primary user(PU) transmitter, and then exploits the harvested energy to perform information forwarding. Our aim is to maximize the sum rate of SUs under the constraints of the data rate of PU, the energy harvesting and the transmit power of the SU relay. To determine the beamforming matrix and TS ratio, we decouple the original non-convex problem into two subproblems which can be solved by semidefinite relaxation and successive convex optimization methods. Furthermore, we derive closed form expressions of the optimal solutions for each subproblem, which facilitates the design of a suboptimal iterative algorithm to handle the original sum rate maximization problem. Simulation results are presented to illustrate the effectiveness and superior performance of the proposed joint design against other conventional schemes in the literature.展开更多
Energy efficiency(EE) of cellular networks has attracted considerable attention recently. However, EE of relay-assisted cellular networks where the macro base stations(MBSs) are equipped with the multi-antenna has not...Energy efficiency(EE) of cellular networks has attracted considerable attention recently. However, EE of relay-assisted cellular networks where the macro base stations(MBSs) are equipped with the multi-antenna has not been thoroughly addressed. This paper considered the downlink transmission of multi-antenna relay-assisted cellular networks, meanwhile, a strategic sleep scheme was used in relay stations(RSs), which dynamically adjusted the RS working mode according to whether the number of users serviced by the relay exceeds a given threshold. A geometric model was built to derive the coverage probability and mean achievable rate from the MBSs to user(UE), the MBS to RS, the RS to UE links and analyze the system EE. It is shown that the energy efficiency of cellular network with strategic sleep RS is slightly higher than that of cellular network with non-sleeping strategy. Furthermore, the MBS equipped with multi-antenna has better impact on energy efficiency and spectral efficiency than the MBS with single antenna.展开更多
In this paper, we present a novel technique based on a mixed Error Correcting Code(ECC)-the convolutional code and the repetition code to enhance the robustness of the embedded watermark. Before embedding, the binary ...In this paper, we present a novel technique based on a mixed Error Correcting Code(ECC)-the convolutional code and the repetition code to enhance the robustness of the embedded watermark. Before embedding, the binary watermark is scanned to one-dimension sequence and later inputted into the (3, 1, 2) convolutional encoder and (3, 1) repetition encoder frame by frame, which will improve the error correcting capability of decoder. The output code sequence is scanned to some matrixes as the new watermark messages. The watermarking is selected in low frequency band of the Discrete Wavelet Transform (DWT) and therefore it can resist the destruction of image processing. Experimental results are presented to demonstrate that the robustness of a watermark with mixed ECC is much higher than the traditional one just with repetition coding while suffering JPEG lossy compression, salt and pepper noise and center cutting processing.展开更多
In response to the increasing penetration of volatile and uncertain renewable energy,the regional transmission organizations(RTOs)have been recently focusing on enhancing the models of pump storage hydropower(PSH)plan...In response to the increasing penetration of volatile and uncertain renewable energy,the regional transmission organizations(RTOs)have been recently focusing on enhancing the models of pump storage hydropower(PSH)plants,which are one of the key flexibility assets in the day-ahead(DA)and real-time(RT)markets,to further boost their flexibility provision potentials.Inspired by the recent research works that explored the potential benefits of excluding PSHs’cost-related terms from the objective functions of the DA market clearing model,this paper completes a rolling RT market scheme that is compatible with the DA market.Then,with the vision that PSHs could be permitted to submit state-of-charge(SOC)headrooms in the DA market and to release them in the RT market,this paper uncovers that PSHs could increase the total revenues from the two markets by optimizing their SOC headrooms,assisted by the proposed tri-level optimal SOC headroom model.Specifically,in the proposed tri-level model,the middle and lower levels respectively mimic the DA and RT scheduling processes of PSHs,and the upper level determines the optimal headrooms to be submitted to the RTO for maximizing the total revenue from the two markets.Numerical case studies quantify the profitability of the optimal SOC headroom submissions as well as the associated financial risks.展开更多
Syncope belongs to the transient loss of consciousness(TLOC), characterized by a rapid onset, short duration, and spontaneous complete recovery. It is common in children and adolescents, accounting for 1% to 2% of eme...Syncope belongs to the transient loss of consciousness(TLOC), characterized by a rapid onset, short duration, and spontaneous complete recovery. It is common in children and adolescents, accounting for 1% to 2% of emergency department visits.Recurrent syncope can seriously affect children's physical and mental health, learning ability and quality of life and sometimes cardiac syncope even poses a risk of sudden death. The present guideline for the diagnosis and treatment of syncope in children and adolescents was developed for guiding a better clinical management of pediatric syncope. Based on the globally recent development and the evidence-based data in China, 2018 Chinese Pediatric Cardiology Society(CPCS) guideline for diagnosis and treatment of syncope in children and adolescents was jointly prepared by the Pediatric Cardiology Society, Chinese Pediatric Society, Chinese Medical Association(CMA)/Committee on Pediatric Syncope, Pediatricians Branch, Chinese Medical Doctor Association(CMDA)/Committee on Pediatric Cardiology, Chinese College of Cardiovascular Physicians, Chinese Medical Doctor Association(CMDA)/Pediatric Cardiology Society, Beijing Pediatric Society, Beijing Medical Association(BMA). The present guideline includes the underlying diseases of syncope in children and adolescents, the diagnostic procedures, methodology and clinical significance of standing test and headup tilt test, the clinical diagnosis vasovagal syncope, postural orthostatic tachycardia syndrome, orthostatic hypotension and orthostatic hypertension, and the treatment of syncope as well as follow-up.展开更多
The discovery of biological activities of natural products plays a vital part in drug development.The mechanism by which organisms respond to temperature changes via biosynthesis of natural products remained largely c...The discovery of biological activities of natural products plays a vital part in drug development.The mechanism by which organisms respond to temperature changes via biosynthesis of natural products remained largely cryptic.A thermophilic fungus under cold stress turned black and accumulated a polyketide metabolite 1 and lipid mass.Deficiency in 1 caused melanin loss and accumulated extra lipid mass,unexpectedly leading to seriously damaged mitochondria diagnostic for ferroptosis.Further analysis revealed that lipid mass induced by cold stress intensively increased ferroptosis risk and 1 functioned as cell wall reinforcer against mass lipid accumulation and as reactive oxygen species scavenger against lipid peroxidation.We also found that melanin in mice lowered lipid level but enhanced animal resistance to cold stress.Treatment with melanin precursors significantly increased mouse cell survival rate under cold stress.Our results unveiled a metabolite-lipid-ferroptosis-cold relationship,which provided mechanistic insights into the functions of most common metabolites and into diseases related to cold stress.These findings opened a perspective for developing anti-cold and anti-ferroptosis therapeutics and agents.展开更多
In differential evolution (DE), the salient feature lies in its mutation mechanism that distinguishes it from other evolutionary algorithms. Generally, for most of the DE algorithms, the parents for mutation are ran...In differential evolution (DE), the salient feature lies in its mutation mechanism that distinguishes it from other evolutionary algorithms. Generally, for most of the DE algorithms, the parents for mutation are randomly chosen from the current population. Hence, all vectors of population have the equal chance to be selected as parents without selective pressure at all. In this way, the information of population cannot be fully exploited to guide the search. To alleviate this drawback and improve the performance of DE, we present a new selection method of parents that attempts to choose individuals for mutation by utilizing the population information effectively. The proposed method is referred as fitnessand-position based selection (FPS), which combines the fitness and position information of population simultaneously for selecting parents in mutation of DE. In order to evaluate the effectiveness of FPS, FPS is applied to the original DE algorithms, as well as several DE variants, for numerical optimization. Experimental results on a suite of benchmark functions indicate that FPS is able to enhance the performance of most DE algorithms studied. Compared with other selection methods, FPS is also shown to be more effective to utilize information of population for guiding the search of DE.展开更多
基金partly supported by the National Natural Science Foundation of China(Grant No.61871241,No.61701221)the Natural Science Foundation of Jiangsu Province(No.BK20160781)+1 种基金Nantong Science and Technology Project(No.JC2018127,No.JC2019117)the Research Innovation Project for College Graduates of Jiangsu Province(No.KYLX16_0662)。
文摘The Poisson point process(PPP) has been widely used in wireless network modeling and performance analysis due to the independence between its nodes. Therefore, it may not be a suitable model for many of the exclusive networks between the nodes. This paper analyzes the energy efficiency(EE) and optimizes the two-tier heterogeneous cellular networks(Het Nets). Considering the mutual exclusion between macro base stations(MBSs) distribution, the deployment of MBSs is modeled by the Matérn hard-core point process(MHCPP), and the deployment of pico base stations(PBSs) is modeled by the PPP. We adopt a simple approximation method to study the signal to interference ratio(SIR) distribution in two-tier MHCPP-PPP networks and then derive the coverage probabilities, the average data rates and the energy efficiency of Het Nets. Finally, an optimization algorithm is proposed to improve the EE of Het Nets by controlling the transmit power of PBSs. The simulation results show that the EE of a system can be effectively improved by selecting the appropriate transmit power for the PBSs. In addition, two-tier MHCPP-PPP Het Nets have higher energy efficiency than two-tier PPP-PPP Het Nets.
基金supported by the National Natural Science Foundation of China(31972576)the Beijing Natural Science Foundation(6202004)+2 种基金the Special Program on Science and Technology Innovation Capacity Building of BAAFS(KJCX20180414 and KJCX201914)the USDA National Institute of Food and Agriculture(2018-68003-27462 and 2018-33610-28252)the Oklahoma Center for the Advancement of Science and Technology(AR19-27)。
文摘Background:In-feed antibiotics are being phased out in livestock production worldwide.Alternatives to antibiotics are urgently needed to maintain animal health and production performance.Host defense peptides(HDPs)are known for their broad-spectrum antimicrobial and immunomodulatory capabilities.Enhancing the synthesis of endogenous HDPs represents a promising antibiotic alternative strategy to disease control and prevention.Methods:To identify natural products with an ability to stimulate the synthesis of endogenous HDPs,we performed a high-throughput screening of 1261 natural products using a newly-established stable luciferase reporter cell line known as IPEC-J2/pBD3-luc.The ability of the hit compounds to induce HDP genes in porcine IPEC-J2 intestinal epithelial cells,3D4/31 macrophages,and jejunal explants were verified using RT-qPCR.Augmentation of the antibacterial activity of porcine 3D4/31 macrophages against a Gram-negative bacterium(enterotoxigenic E.coli)and a Gram-positive bacterium(Staphylococcus aureus)were further confirmed with four selected HDP-inducing compounds.Results:A total of 48 natural products with a minimum Z-score of 2.0 were identified after high-throughput screening,with 21 compounds giving at least 2-fold increase in luciferase activity in a follow-up dose-response experiment.Xanthohumol and deoxyshikonin were further found to be the most potent in inducing pBD3 mRNA expression,showing a minimum 10-fold increase in IPEC-J2,3D4/31 cells,and jejunal explants.Other compounds such as isorhapontigenin and calycosin also enhanced pBD3 mRNA expression by at least 10-fold in both IPEC-J2 cells and jejunal explants,but not 3D4/31 cells.In addition to pBD3,other porcine HDP genes such as pBD2,PG1-5,and pEP2C were induced to different magnitudes by xanthohumol,deoxyshikonin,isorhapontigenin,and calycosin,although clear gene-and cell type-specific patterns of regulation were observed.Desirably,these four compounds had a minimum effect on the expression of several representative inflammatory cytokine genes.Furthermore,when used at HDP-inducing concentrations,these compounds showed no obvious direct antibacterial activity,but significantly augmented the antibacterial activity of 3D4/31 macrophages(P<0.05)against both Gram-negative and Gram-positive bacteria.Conclusions:Our results indicate that these newly-identified natural HDP-inducing compounds have the potential to be developed as novel alternatives to antibiotics for prophylactic and therapeutic treatment of infectious diseases in livestock production.
基金supported by National Natural Science Foundation of China(No.61871241,No.61771263)Science and Technology Program of Nantong(No.JC2018129,No.JC2018127)Fund of Nantong University-Nantong Joint Research Center for Intelligent Information Technology(No.KFKT2016A01,No.KFKT2017A05)。
文摘With the development of society and the progress of technology,more and more ocean activities are carried out.It results in booming of deep-sea diving.The use of helium-oxygen mixture(as a kind of breathing gas)solves the physiological problems of divers in saturated diving,but it brings about the Heliumspeech voice communication problem,the drop of speech intelligibility.There is no doubt that the effective speech communication must be provided for supporting the life and work of divers in deep-sea.This paper describes the mechanism of forming heliumspeech,discusses the effects of pressure and helium environment on the speech spectrum,compares the pros and cons of the time-domain and frequency-domain unscrambling techniques,shows the challenges in heliumspeech communications.Finally,it briefly introduces the deep learning,and points out that deep learning/machine learning may be a perfectly unscrambling technique.
文摘Background: This study aimed to illustrate the prevalence of CHD by screening children in extremely high-altitudeareas (over 4000 m to even 5000 m above sea level) and explore an aid model for early diagnosis and treatmentfor the Tibetan population. Methods: A total of 2242 students from different schools in Ngamring County,Xigaze City, Tibet from September 2019 to September 2020 were selected for screening. The students were examinedthrough the inquiry of their current medical history and family history, cardiac auscultation and a physicalexamination, in order to screen out the suspected cases of CHD, and then the suspected cases were confirmed bycardiac color ultrasound examinations. After that, positive patients were be transferred to Shandong Province forfree treatment. Results: The prevalence of CHD among children in Ngamring County was 3.70% (83 cases),which is the highest incidence rate ever reported. The most common type of CHD was patent ductus arteriosus(PDA), accounting for 55.42% of the total number of cases screened, followed by atrial septal defect (ASD) andventricular septal defect (VSD), accounting for 28.92% and 12.05%, respectively. The prevalence of CHD in childrenat high altitude was significantly higher than that in children at low altitude. The children with CHD weretransferred to Shandong Province for surgery, the operations were successful and their recoveries went well.Conclusions: The results show that high altitude is closely related to the prevalence of CHD, and the incidencein Ngamring County is much higher than that in previous reports.
基金National Natural Science Foundation of China (61871241, 61771263)Postgraduate Research and Practice Innovation Program of Jiangsu Province (KYCX18-2422)+3 种基金Six Categories Talent Peak of Jiangsu Province (KTHY-039)Science and Technology Program of Nantong (JC2018127, JC2018129, GY22017013)Stereoscopic Coverage Communication Network Verification Platform for China Sea (PCL2018KP002)Open Research Fund of Nantong University-Nantong Joint Research Center for Intelligent Information Technology (KFKT2017A05, KFKT2017B02)
文摘In this paper, we investigate a joint beamforming and time switching(TS) design for an energy-constrained cognitive two-way relay(TWR) network. In the network, the energy-constrained secondary user(SU) relay employs TS protocol to harvest energy from the signals sent by the circuit-powered primary user(PU) transmitter, and then exploits the harvested energy to perform information forwarding. Our aim is to maximize the sum rate of SUs under the constraints of the data rate of PU, the energy harvesting and the transmit power of the SU relay. To determine the beamforming matrix and TS ratio, we decouple the original non-convex problem into two subproblems which can be solved by semidefinite relaxation and successive convex optimization methods. Furthermore, we derive closed form expressions of the optimal solutions for each subproblem, which facilitates the design of a suboptimal iterative algorithm to handle the original sum rate maximization problem. Simulation results are presented to illustrate the effectiveness and superior performance of the proposed joint design against other conventional schemes in the literature.
基金partly supported by the National Natural Science Foundation of China (Grant No. 61371112, No.61701221 )the Jiangsu Natural Science Foundation (No. BK20160781)+2 种基金Jiangsu Higher Education Institutions Natural Science Foundation (No. 16KJB510013, 16KJB510038)the Research Innovation Project for College Graduates of Jiangsu Province (No. KYLX16_0662)the Natural Science Foundation of Nantong University Xinglin College (No. 2016K116)
文摘Energy efficiency(EE) of cellular networks has attracted considerable attention recently. However, EE of relay-assisted cellular networks where the macro base stations(MBSs) are equipped with the multi-antenna has not been thoroughly addressed. This paper considered the downlink transmission of multi-antenna relay-assisted cellular networks, meanwhile, a strategic sleep scheme was used in relay stations(RSs), which dynamically adjusted the RS working mode according to whether the number of users serviced by the relay exceeds a given threshold. A geometric model was built to derive the coverage probability and mean achievable rate from the MBSs to user(UE), the MBS to RS, the RS to UE links and analyze the system EE. It is shown that the energy efficiency of cellular network with strategic sleep RS is slightly higher than that of cellular network with non-sleeping strategy. Furthermore, the MBS equipped with multi-antenna has better impact on energy efficiency and spectral efficiency than the MBS with single antenna.
文摘In this paper, we present a novel technique based on a mixed Error Correcting Code(ECC)-the convolutional code and the repetition code to enhance the robustness of the embedded watermark. Before embedding, the binary watermark is scanned to one-dimension sequence and later inputted into the (3, 1, 2) convolutional encoder and (3, 1) repetition encoder frame by frame, which will improve the error correcting capability of decoder. The output code sequence is scanned to some matrixes as the new watermark messages. The watermarking is selected in low frequency band of the Discrete Wavelet Transform (DWT) and therefore it can resist the destruction of image processing. Experimental results are presented to demonstrate that the robustness of a watermark with mixed ECC is much higher than the traditional one just with repetition coding while suffering JPEG lossy compression, salt and pepper noise and center cutting processing.
文摘In response to the increasing penetration of volatile and uncertain renewable energy,the regional transmission organizations(RTOs)have been recently focusing on enhancing the models of pump storage hydropower(PSH)plants,which are one of the key flexibility assets in the day-ahead(DA)and real-time(RT)markets,to further boost their flexibility provision potentials.Inspired by the recent research works that explored the potential benefits of excluding PSHs’cost-related terms from the objective functions of the DA market clearing model,this paper completes a rolling RT market scheme that is compatible with the DA market.Then,with the vision that PSHs could be permitted to submit state-of-charge(SOC)headrooms in the DA market and to release them in the RT market,this paper uncovers that PSHs could increase the total revenues from the two markets by optimizing their SOC headrooms,assisted by the proposed tri-level optimal SOC headroom model.Specifically,in the proposed tri-level model,the middle and lower levels respectively mimic the DA and RT scheduling processes of PSHs,and the upper level determines the optimal headrooms to be submitted to the RTO for maximizing the total revenue from the two markets.Numerical case studies quantify the profitability of the optimal SOC headroom submissions as well as the associated financial risks.
文摘Syncope belongs to the transient loss of consciousness(TLOC), characterized by a rapid onset, short duration, and spontaneous complete recovery. It is common in children and adolescents, accounting for 1% to 2% of emergency department visits.Recurrent syncope can seriously affect children's physical and mental health, learning ability and quality of life and sometimes cardiac syncope even poses a risk of sudden death. The present guideline for the diagnosis and treatment of syncope in children and adolescents was developed for guiding a better clinical management of pediatric syncope. Based on the globally recent development and the evidence-based data in China, 2018 Chinese Pediatric Cardiology Society(CPCS) guideline for diagnosis and treatment of syncope in children and adolescents was jointly prepared by the Pediatric Cardiology Society, Chinese Pediatric Society, Chinese Medical Association(CMA)/Committee on Pediatric Syncope, Pediatricians Branch, Chinese Medical Doctor Association(CMDA)/Committee on Pediatric Cardiology, Chinese College of Cardiovascular Physicians, Chinese Medical Doctor Association(CMDA)/Pediatric Cardiology Society, Beijing Pediatric Society, Beijing Medical Association(BMA). The present guideline includes the underlying diseases of syncope in children and adolescents, the diagnostic procedures, methodology and clinical significance of standing test and headup tilt test, the clinical diagnosis vasovagal syncope, postural orthostatic tachycardia syndrome, orthostatic hypotension and orthostatic hypertension, and the treatment of syncope as well as follow-up.
基金supported by the National Natural Science Foundation of China(21977086,82260691,and 21867018)“Double tops”from Yunnan Province and Yunnan University(202201BF070001-012)the Yunnan Innovative Research Team for Discovery and Biosynthesis of Bioactive Natural Products(2018HC012)。
文摘The discovery of biological activities of natural products plays a vital part in drug development.The mechanism by which organisms respond to temperature changes via biosynthesis of natural products remained largely cryptic.A thermophilic fungus under cold stress turned black and accumulated a polyketide metabolite 1 and lipid mass.Deficiency in 1 caused melanin loss and accumulated extra lipid mass,unexpectedly leading to seriously damaged mitochondria diagnostic for ferroptosis.Further analysis revealed that lipid mass induced by cold stress intensively increased ferroptosis risk and 1 functioned as cell wall reinforcer against mass lipid accumulation and as reactive oxygen species scavenger against lipid peroxidation.We also found that melanin in mice lowered lipid level but enhanced animal resistance to cold stress.Treatment with melanin precursors significantly increased mouse cell survival rate under cold stress.Our results unveiled a metabolite-lipid-ferroptosis-cold relationship,which provided mechanistic insights into the functions of most common metabolites and into diseases related to cold stress.These findings opened a perspective for developing anti-cold and anti-ferroptosis therapeutics and agents.
文摘In differential evolution (DE), the salient feature lies in its mutation mechanism that distinguishes it from other evolutionary algorithms. Generally, for most of the DE algorithms, the parents for mutation are randomly chosen from the current population. Hence, all vectors of population have the equal chance to be selected as parents without selective pressure at all. In this way, the information of population cannot be fully exploited to guide the search. To alleviate this drawback and improve the performance of DE, we present a new selection method of parents that attempts to choose individuals for mutation by utilizing the population information effectively. The proposed method is referred as fitnessand-position based selection (FPS), which combines the fitness and position information of population simultaneously for selecting parents in mutation of DE. In order to evaluate the effectiveness of FPS, FPS is applied to the original DE algorithms, as well as several DE variants, for numerical optimization. Experimental results on a suite of benchmark functions indicate that FPS is able to enhance the performance of most DE algorithms studied. Compared with other selection methods, FPS is also shown to be more effective to utilize information of population for guiding the search of DE.