BACKGROUND Intracranial hemorrhage after spinal surgery is a rare and devastating complication.AIM To investigate the economic burden,clinical characteristics,risk factors,and mechanisms of intracranial hemorrhage aft...BACKGROUND Intracranial hemorrhage after spinal surgery is a rare and devastating complication.AIM To investigate the economic burden,clinical characteristics,risk factors,and mechanisms of intracranial hemorrhage after spinal surgery.METHODS A retrospective cohort study was conducted from January 1,2015,to December 31,2022.Patients aged≥18 years,who had undergone spinal surgery were included.Intracranial hemorrhage patients were selected after spinal surgery during hospitalization.Based on the type of spinal surgery,patients with intracranial hemorrhage were randomly matched in a 1:5 ratio with control patients without intracranial hemorrhage.The patients'pre-,intra-,and post-operative data and clinical manifestations were recorded.RESULTS A total of 24472 patients underwent spinal surgery.Six patients(3 males and 3 females,average age 71.3 years)developed intracranial hemorrhage after posterior spinal fusion procedures,with an incidence of 0.025%(6/24472).The prevailing type of intracranial hemorrhage was cerebellar hemorrhage.Two patients had a poor clinical outcome.Based on the type of surgery,30 control patients were randomly matched in 1:5 ratio.The intracranial hemorrhage group showed significant differences compared with the control group with regard to age(71.33±7.45 years vs 58.39±8.07 years,P=0.001),previous history of cerebrovascular disease(50%vs 6.7%,P=0.024),spinal dura mater injury(50%vs 3.3%,P=0.010),hospital expenses(RMB 242119.1±87610.0 vs RMB 96290.7±32029.9,P=0.009),and discharge activity daily living score(40.00±25.88 vs 75.40±18.29,P=0.019).CONCLUSION The incidence of intracranial hemorrhage after spinal surgery was extremely low,with poor clinical outcomes.Patient age,previous stroke history,and dura mater damage were possible risk factors.It is suggested that spinal dura mater injury should be avoided during surgery in high-risk patients.展开更多
The stability issue has become one of the main challenges for the commercialization of perovskite solar cells(PSCs).Formamidinium(FA)-based perovskites have shown great promise owing to their improved thermal and mois...The stability issue has become one of the main challenges for the commercialization of perovskite solar cells(PSCs).Formamidinium(FA)-based perovskites have shown great promise owing to their improved thermal and moisture stability.However,these perovskites are suffering from phase transition and separation.Here,a method of incorporating of γ-aminobutyric acid(GABA) and cesium cations into FAPbl_(3) is developed to improve the phase stability.It is demonstrated that the crystallinity of α-FAPbl_(3) phase is greatly improved and the phase transition temperature is significantly dropped.The resultant solar cell therefore obtains a champion power conversion efficiency(PCE) of 23.71%,which is one of the highest efficiencies for methylammonium-free PSCs.Furthermore,it shows an impressively enhanced stability under illumination,exhibiting the great potential of FA-based perovskites for efficient and stable solar cells.展开更多
Since the discovery of graphene,the development of two-dimensional material research has enabled the exploration of a rich variety of exotic quantum phenomena that are not accessible in bulk materials.These two-dimens...Since the discovery of graphene,the development of two-dimensional material research has enabled the exploration of a rich variety of exotic quantum phenomena that are not accessible in bulk materials.These two-dimensional materials offer a unique platform to build novel quantum devices.Layered transition metal dichalcogenides,when thinned down to atomic thicknesses,exhibit intriguing physical properties such as strong electron correlations.The study of strongly-correlated phenomena in twodimensional transition metal dichalcogenides has been a major research frontier in condensed matter physics.In this article,we review recent progress on strongly-correlated phenomena in two-dimensional transition metal dichalcogenides,including Mott insulators,quantum spin liquids,and Wigner crystals.These topics represent a rapidly developing research area,where tremendous opportunities exist in discovering exotic quantum phenomena,and in exploring their applications for future electronic devices.展开更多
One of the biggest puzzles concerning the cup- rate high temperature superconductors is what determines the maximum transition temperature (Tc,max), which varies from less than 30 to above 130 K in different compoun...One of the biggest puzzles concerning the cup- rate high temperature superconductors is what determines the maximum transition temperature (Tc,max), which varies from less than 30 to above 130 K in different compounds. Despite this dramatic variation, a robust trend is that within each family, the double-layer compound always has higher Tc,max than the single-layer counterpart. Here we use scanning tunneling microscopy to investigate the electronic structure of four cuprate parent compounds belonging to two different families. We find that within each family, the double layer compound has a much smaller charge transfer gap size (ACT), indicating a clear anticorrelation between AcT and Tc,max. These results suggest that the charge transfer gap plays a key role in the superconducting physics of cuprates, which shed important new light on the high To mechanism from doped Mott insulator perspective.展开更多
Background: In areas where malaria has been eliminated, delayed care-seeking and diagnosis of imported malaria are constant threats. This study aimed to describe the profile and determinants of delayed care-seeking an...Background: In areas where malaria has been eliminated, delayed care-seeking and diagnosis of imported malaria are constant threats. This study aimed to describe the profile and determinants of delayed care-seeking and diagnosis among patients with imported malaria in China.Methods: This retrospective study assessed surveillance data obtained from 2014 to 2021 in the Chinese provincial-level administrative divisions (PLADs) of Anhui, Henan, Hubei, and Zhejiang, and Guangxi. Epidemiological characteristics were analyzed using descriptive statistics. Furthermore, factors associated with delayed care-seeking and diagnosis among imported malaria cases were identified using multivariate logistic regression.Results: Overall, 11.81% and 30.08% of imported malaria cases had delays in seeking care and diagnosis, respectively. During the study period, there was a decreasing trend in the proportion of imported malaria cases with delayed care-seeking (χ^(2) = 36.099,P < 0.001) and diagnosis (χ^(2) = 11.395,P = 0.001). In multivariate analysis, independent risk factors associated with delayed care-seeking include PLADs (Guangxi as reference), consultations in high-level facilities for the first medical visit, infections with non-Plasmodium falciparum species, and older age. However, PLADs (Guangxi as reference), the purpose of traveling (labour as reference), and infections with non-P. falciparum species increased the risk of delayed diagnosis. Delayed care-seeking (adjusted odds ratio: 1.79,P = 0.001) and diagnosis (adjusted odds ratio: 1.62,P = 0.004) were risk factors for severe disease development.Conclusions: Based on this study’s findings, we strongly advocate for improved access to quality healthcare to reduce the rate of misdiagnosis at the first visit. Infections caused by non-P. falciparum species should be highlighted, and more sensitive and specific point-of-care detection methods for non-P. falciparum species should be developed and implemented. In addition, education programs should be enhanced to reach target populations at risk of malaria infection. All these factors may reduce delayed care-seeking and diagnosis of imported malaria.展开更多
In recent years,Power Shell has increasingly been reported as appearing in a variety of cyber attacks.However,because the PowerShell language is dynamic by design and can construct script fragments at different levels...In recent years,Power Shell has increasingly been reported as appearing in a variety of cyber attacks.However,because the PowerShell language is dynamic by design and can construct script fragments at different levels,state-of-the-art static analysis based Power Shell attack detection approaches are inherently vulnerable to obfuscations.In this paper,we design the first generic,effective,and lightweight deobfuscation approach for PowerShell scripts.To precisely identify the obfuscated script fragments,we define obfuscation based on the differences in the impacts on the abstract syntax trees of PowerShell scripts and propose a novel emulation-based recovery technology.Furthermore,we design the first semantic-aware PowerShell attack detection system that leverages the classic objective-oriented association mining algorithm and newly identifies 31 semantic signatures.The experimental results on 2342 benign samples and 4141 malicious samples show that our deobfuscation method takes less than 0.5 s on average and increases the similarity between the obfuscated and original scripts from 0.5%to 93.2%.By deploying our deobfuscation method,the attack detection rates for Windows Defender and VirusTotal increase substantially from 0.33%and 2.65%to 78.9%and 94.0%,respectively.Moreover,our detection system outperforms both existing tools with a 96.7%true positive rate and a 0%false positive rate on average.展开更多
Background:Plasmodium vivax remains a potential cause of morbidity and mortality for people living in its endemic areas.Understanding the genetic diversity of P.vivax from different regions is valuable for studying po...Background:Plasmodium vivax remains a potential cause of morbidity and mortality for people living in its endemic areas.Understanding the genetic diversity of P.vivax from different regions is valuable for studying population dynamics and tracing the origins of parasites.The PvMSP-1 gene is highly polymorphic and has been used as a marker in many P.vivax population studies.The aim of this study was to investigate the genetic diversity of the PvMSP-1 gene icb5-6 fragment and to provide more genetic polymorphism data for further studies on P.vivax population structure and tracking of the origin of clinical cases.Methods:Nested PCR and sequencing of the PvMSP-1 icb5-6 marker were performed to obtain the nucleotide sequences of 95 P.vivax isolates collected from Zhejiang province,China.To investigate the genetic diversity of PvMSP-1,the 95 nucleotide sequences of the PvMSP-1 icb5-6 fragment were genotyped and analyzed using DnaSP v5,MEGA software.Results:The 95 P.vivax isolates collected from Zhejiang province were either indigenous cases or imported cases from different regions around the world.A total of 95 sequences ranging from 390 to 460 bp were obtained.The 95 sequences were genotyped into four allele-types(Sal I,Belem,R-III and R-IV)and 17 unique haplotypes.R-III and Sal I were the predominant allele-types.The haplotype diversity(Hd)and nucleotide diversity(Pi)were estimated to be 0.729 and 0.062,indicating that the PvMSP-1 icb5-6 fragment had the highest level of polymorphism due to frequent recombination processes and single nucleotide polymorphism.The values of dN/dS and Tajima’s D both suggested neutral selection for the PvMSP-1icb5-6 fragment.In addition,a rare recombinant style of R-IV type was identified.Conclusions:This study presented high genetic diversity in the PvMSP-1 marker among P.vivax strains from around the world.The genetic data is valuable for expanding the polymorphism information on P.vivax,which could be helpful for further study on population dynamics and tracking the origin of P.vivax.展开更多
All-inorganic CsPbI_(2)Br perovskite with suitable bandgap and excellent thermal stability has been reported as the most promising candidate for efficient perovskite solar cells (PSCs). However, the high annealing tem...All-inorganic CsPbI_(2)Br perovskite with suitable bandgap and excellent thermal stability has been reported as the most promising candidate for efficient perovskite solar cells (PSCs). However, the high annealing temperature (> 250 ℃) and poor stability of α-CsPbI_(2)Br greatly limit the future application in photovoltaic field. Herein, a facile method is reported to prepare α-CsPbI_(2)Br perovskite film with high stability at low temperature (70 ℃) by incorporating a small amount of γ-aminobutyric acid (GABA) in the precursor solutions. The devices exhibit reproducible photovoltaic performance with a champion efficiency up to 15.16%, along with the excellent stability, maintaining more than 80% of its initial efficiency after stored in ambient condition for 600 h without any encapsulation. Most importantly, the method enables fabrication of semitransparent CsPbI_(2)Br PSCs with a PCE of 6.76%, as well as an average visible transparency (AVT) of 25.38%. To the best of our knowledge, this is the first attempt to apply CsPbI_(2)Br to the semitransparent solar cells.展开更多
Dielectric,hysteresis(P–E)loops and TSDC properties of transparent 85PZN–15BT ceramic over150–150℃ were investigated.The sample was found to exhibit a strong relaxor behavior and a relatively small remanent polar...Dielectric,hysteresis(P–E)loops and TSDC properties of transparent 85PZN–15BT ceramic over150–150℃ were investigated.The sample was found to exhibit a strong relaxor behavior and a relatively small remanent polarization.TSDC studies showed that there existed an electric field-dependent peak in the p versus T.Such interesting features were attributed to the electric field-induced transition and coexistence of polar nanoregion,long-range ordered polar region and nonpolarizable BZN-rich region.展开更多
基金“Xue Ke Xin Xing”of Beijing Jishuitan Hospital,Beijing,China,No.XKXX201611。
文摘BACKGROUND Intracranial hemorrhage after spinal surgery is a rare and devastating complication.AIM To investigate the economic burden,clinical characteristics,risk factors,and mechanisms of intracranial hemorrhage after spinal surgery.METHODS A retrospective cohort study was conducted from January 1,2015,to December 31,2022.Patients aged≥18 years,who had undergone spinal surgery were included.Intracranial hemorrhage patients were selected after spinal surgery during hospitalization.Based on the type of spinal surgery,patients with intracranial hemorrhage were randomly matched in a 1:5 ratio with control patients without intracranial hemorrhage.The patients'pre-,intra-,and post-operative data and clinical manifestations were recorded.RESULTS A total of 24472 patients underwent spinal surgery.Six patients(3 males and 3 females,average age 71.3 years)developed intracranial hemorrhage after posterior spinal fusion procedures,with an incidence of 0.025%(6/24472).The prevailing type of intracranial hemorrhage was cerebellar hemorrhage.Two patients had a poor clinical outcome.Based on the type of surgery,30 control patients were randomly matched in 1:5 ratio.The intracranial hemorrhage group showed significant differences compared with the control group with regard to age(71.33±7.45 years vs 58.39±8.07 years,P=0.001),previous history of cerebrovascular disease(50%vs 6.7%,P=0.024),spinal dura mater injury(50%vs 3.3%,P=0.010),hospital expenses(RMB 242119.1±87610.0 vs RMB 96290.7±32029.9,P=0.009),and discharge activity daily living score(40.00±25.88 vs 75.40±18.29,P=0.019).CONCLUSION The incidence of intracranial hemorrhage after spinal surgery was extremely low,with poor clinical outcomes.Patient age,previous stroke history,and dura mater damage were possible risk factors.It is suggested that spinal dura mater injury should be avoided during surgery in high-risk patients.
基金financial support from the Taishan Scholar Project of Shandong Province under Grant No. tsqn201812098the Shandong Provincial Natural Science Foundation (ZR2020MF103, ZR2019MF057, and ZR2019MA066)+1 种基金National Natural Science Foundation of China (21701080)Postgraduate Research & Practice Innovation Program of Jiangsu Province.
文摘The stability issue has become one of the main challenges for the commercialization of perovskite solar cells(PSCs).Formamidinium(FA)-based perovskites have shown great promise owing to their improved thermal and moisture stability.However,these perovskites are suffering from phase transition and separation.Here,a method of incorporating of γ-aminobutyric acid(GABA) and cesium cations into FAPbl_(3) is developed to improve the phase stability.It is demonstrated that the crystallinity of α-FAPbl_(3) phase is greatly improved and the phase transition temperature is significantly dropped.The resultant solar cell therefore obtains a champion power conversion efficiency(PCE) of 23.71%,which is one of the highest efficiencies for methylammonium-free PSCs.Furthermore,it shows an impressively enhanced stability under illumination,exhibiting the great potential of FA-based perovskites for efficient and stable solar cells.
基金support from the National Natural Science Foundation of China(Grant No.12274087)Shanghai Science and Technology Development Funds(Grant No.22QA1400600)+2 种基金support from the National Key R&D Program of China(Grant No.2018YFA0305600)Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB30000000)Shanghai Municipal Science and Technology Commission(Grant No.2019SHZDZX01)。
文摘Since the discovery of graphene,the development of two-dimensional material research has enabled the exploration of a rich variety of exotic quantum phenomena that are not accessible in bulk materials.These two-dimensional materials offer a unique platform to build novel quantum devices.Layered transition metal dichalcogenides,when thinned down to atomic thicknesses,exhibit intriguing physical properties such as strong electron correlations.The study of strongly-correlated phenomena in twodimensional transition metal dichalcogenides has been a major research frontier in condensed matter physics.In this article,we review recent progress on strongly-correlated phenomena in two-dimensional transition metal dichalcogenides,including Mott insulators,quantum spin liquids,and Wigner crystals.These topics represent a rapidly developing research area,where tremendous opportunities exist in discovering exotic quantum phenomena,and in exploring their applications for future electronic devices.
基金supported by the National Natural Science Foundation of China and Ministry of Science and Technology of the People’s Republic of Chinafinancial support from the Strategic Priority Research Program (B) of the Chinese Academy of Sciences (XDB07020300)
文摘One of the biggest puzzles concerning the cup- rate high temperature superconductors is what determines the maximum transition temperature (Tc,max), which varies from less than 30 to above 130 K in different compounds. Despite this dramatic variation, a robust trend is that within each family, the double-layer compound always has higher Tc,max than the single-layer counterpart. Here we use scanning tunneling microscopy to investigate the electronic structure of four cuprate parent compounds belonging to two different families. We find that within each family, the double layer compound has a much smaller charge transfer gap size (ACT), indicating a clear anticorrelation between AcT and Tc,max. These results suggest that the charge transfer gap plays a key role in the superconducting physics of cuprates, which shed important new light on the high To mechanism from doped Mott insulator perspective.
基金National Natural Science Foundation of China(No. 32161143036).
文摘Background: In areas where malaria has been eliminated, delayed care-seeking and diagnosis of imported malaria are constant threats. This study aimed to describe the profile and determinants of delayed care-seeking and diagnosis among patients with imported malaria in China.Methods: This retrospective study assessed surveillance data obtained from 2014 to 2021 in the Chinese provincial-level administrative divisions (PLADs) of Anhui, Henan, Hubei, and Zhejiang, and Guangxi. Epidemiological characteristics were analyzed using descriptive statistics. Furthermore, factors associated with delayed care-seeking and diagnosis among imported malaria cases were identified using multivariate logistic regression.Results: Overall, 11.81% and 30.08% of imported malaria cases had delays in seeking care and diagnosis, respectively. During the study period, there was a decreasing trend in the proportion of imported malaria cases with delayed care-seeking (χ^(2) = 36.099,P < 0.001) and diagnosis (χ^(2) = 11.395,P = 0.001). In multivariate analysis, independent risk factors associated with delayed care-seeking include PLADs (Guangxi as reference), consultations in high-level facilities for the first medical visit, infections with non-Plasmodium falciparum species, and older age. However, PLADs (Guangxi as reference), the purpose of traveling (labour as reference), and infections with non-P. falciparum species increased the risk of delayed diagnosis. Delayed care-seeking (adjusted odds ratio: 1.79,P = 0.001) and diagnosis (adjusted odds ratio: 1.62,P = 0.004) were risk factors for severe disease development.Conclusions: Based on this study’s findings, we strongly advocate for improved access to quality healthcare to reduce the rate of misdiagnosis at the first visit. Infections caused by non-P. falciparum species should be highlighted, and more sensitive and specific point-of-care detection methods for non-P. falciparum species should be developed and implemented. In addition, education programs should be enhanced to reach target populations at risk of malaria infection. All these factors may reduce delayed care-seeking and diagnosis of imported malaria.
基金supported by the National Natural Science Foundation of China(No.U1936215)。
文摘In recent years,Power Shell has increasingly been reported as appearing in a variety of cyber attacks.However,because the PowerShell language is dynamic by design and can construct script fragments at different levels,state-of-the-art static analysis based Power Shell attack detection approaches are inherently vulnerable to obfuscations.In this paper,we design the first generic,effective,and lightweight deobfuscation approach for PowerShell scripts.To precisely identify the obfuscated script fragments,we define obfuscation based on the differences in the impacts on the abstract syntax trees of PowerShell scripts and propose a novel emulation-based recovery technology.Furthermore,we design the first semantic-aware PowerShell attack detection system that leverages the classic objective-oriented association mining algorithm and newly identifies 31 semantic signatures.The experimental results on 2342 benign samples and 4141 malicious samples show that our deobfuscation method takes less than 0.5 s on average and increases the similarity between the obfuscated and original scripts from 0.5%to 93.2%.By deploying our deobfuscation method,the attack detection rates for Windows Defender and VirusTotal increase substantially from 0.33%and 2.65%to 78.9%and 94.0%,respectively.Moreover,our detection system outperforms both existing tools with a 96.7%true positive rate and a 0%false positive rate on average.
基金This research was supported by the Medical Science and Technique Project of Zhejiang Province(No.2013KYA041,No.2014KYB324).
文摘Background:Plasmodium vivax remains a potential cause of morbidity and mortality for people living in its endemic areas.Understanding the genetic diversity of P.vivax from different regions is valuable for studying population dynamics and tracing the origins of parasites.The PvMSP-1 gene is highly polymorphic and has been used as a marker in many P.vivax population studies.The aim of this study was to investigate the genetic diversity of the PvMSP-1 gene icb5-6 fragment and to provide more genetic polymorphism data for further studies on P.vivax population structure and tracking of the origin of clinical cases.Methods:Nested PCR and sequencing of the PvMSP-1 icb5-6 marker were performed to obtain the nucleotide sequences of 95 P.vivax isolates collected from Zhejiang province,China.To investigate the genetic diversity of PvMSP-1,the 95 nucleotide sequences of the PvMSP-1 icb5-6 fragment were genotyped and analyzed using DnaSP v5,MEGA software.Results:The 95 P.vivax isolates collected from Zhejiang province were either indigenous cases or imported cases from different regions around the world.A total of 95 sequences ranging from 390 to 460 bp were obtained.The 95 sequences were genotyped into four allele-types(Sal I,Belem,R-III and R-IV)and 17 unique haplotypes.R-III and Sal I were the predominant allele-types.The haplotype diversity(Hd)and nucleotide diversity(Pi)were estimated to be 0.729 and 0.062,indicating that the PvMSP-1 icb5-6 fragment had the highest level of polymorphism due to frequent recombination processes and single nucleotide polymorphism.The values of dN/dS and Tajima’s D both suggested neutral selection for the PvMSP-1icb5-6 fragment.In addition,a rare recombinant style of R-IV type was identified.Conclusions:This study presented high genetic diversity in the PvMSP-1 marker among P.vivax strains from around the world.The genetic data is valuable for expanding the polymorphism information on P.vivax,which could be helpful for further study on population dynamics and tracking the origin of P.vivax.
基金financial support from the Taishan Scholar Project of Shandong Province (No. tsqn201812098)the Shandong Provincial Natural Science Foundation (Nos. ZR2020MF103,ZR2019MF057 and ZR2019MA066)National Natural Science Foundation of China (No. 21701080)。
文摘All-inorganic CsPbI_(2)Br perovskite with suitable bandgap and excellent thermal stability has been reported as the most promising candidate for efficient perovskite solar cells (PSCs). However, the high annealing temperature (> 250 ℃) and poor stability of α-CsPbI_(2)Br greatly limit the future application in photovoltaic field. Herein, a facile method is reported to prepare α-CsPbI_(2)Br perovskite film with high stability at low temperature (70 ℃) by incorporating a small amount of γ-aminobutyric acid (GABA) in the precursor solutions. The devices exhibit reproducible photovoltaic performance with a champion efficiency up to 15.16%, along with the excellent stability, maintaining more than 80% of its initial efficiency after stored in ambient condition for 600 h without any encapsulation. Most importantly, the method enables fabrication of semitransparent CsPbI_(2)Br PSCs with a PCE of 6.76%, as well as an average visible transparency (AVT) of 25.38%. To the best of our knowledge, this is the first attempt to apply CsPbI_(2)Br to the semitransparent solar cells.
基金supported by the National Key Project for Basic Research of China(2009CB623305)the National Nature Science Foundation of China(Nos.61137004,51107140,and 61275181)the External Cooperation Program of the Chinese Academy of Sciences(No.GJHZ1042).
文摘Dielectric,hysteresis(P–E)loops and TSDC properties of transparent 85PZN–15BT ceramic over150–150℃ were investigated.The sample was found to exhibit a strong relaxor behavior and a relatively small remanent polarization.TSDC studies showed that there existed an electric field-dependent peak in the p versus T.Such interesting features were attributed to the electric field-induced transition and coexistence of polar nanoregion,long-range ordered polar region and nonpolarizable BZN-rich region.