With rapid development and wide application of information technology,mankind is entering into an information age.The world where people live and work has been changed to a brand new triple-dimensional space that cons...With rapid development and wide application of information technology,mankind is entering into an information age.The world where people live and work has been changed to a brand new triple-dimensional space that consists of the physical world,the human society and the cyberspace.It is well known that the cyberspace is an essential environment of human existence and development and it展开更多
BACKGROUND Renal involvement in lymphoma is commonly associated with widespread nodal or extranodal lymphoma.Primary renal diffuse large B-cell lymphoma is an extremely rare extranodal lymphoma,accounting for fewer th...BACKGROUND Renal involvement in lymphoma is commonly associated with widespread nodal or extranodal lymphoma.Primary renal diffuse large B-cell lymphoma is an extremely rare extranodal lymphoma,accounting for fewer than 1%of all renal masses.Interestingly,the patient in this study had a renal vein tumor thrombus that was observed after laparoscopic radical nephrectomy.CASE SUMMARY We report the case of a 56-year-old female patient with primary renal lymphoma and a renal vein tumor thrombus whose first symptom was right pain in the back and gross hematuria.Histopathology revealed primary renal diffuse large B-cell lymphoma.The patient received 8 standard cycles of rituximab with cyclophosphamide,doxorubicin,vincristine,and prednisone chemotherapy after surgery,and no obvious signs of recurrence were observed during the one-year follow-up.CONCLUSION We evaluated comprehensive treatment of primary renal diffuse large B-cell lymphoma and multidisciplinary management of this malignancy.展开更多
These years, Chinese oil painters have come to realize that they should try to tap into and representthe spirit and ideas of Chinese culture in their oil paintings. ＂Imagist oil painting＂ has thus become a common pu...These years, Chinese oil painters have come to realize that they should try to tap into and representthe spirit and ideas of Chinese culture in their oil paintings. ＂Imagist oil painting＂ has thus become a common pursuit among many Chinese oil painters. To some extent, the ＂imagist＂ movement shares similarities with the expressionism in Western art tradition, both pursuing individualized and subiective artist expression. However, more directly, it draws upon the time-honored tradition of ＂freehand＂ style in Chinese painting.展开更多
Background:With an increasing proportion of multiparas,proper interpregnancy intervals(IPIs)are urgently needed.However,the association between IPIs and adverse perinatal outcomes has always been debated.This study ai...Background:With an increasing proportion of multiparas,proper interpregnancy intervals(IPIs)are urgently needed.However,the association between IPIs and adverse perinatal outcomes has always been debated.This study aimed to explore the association between IPIs and adverse outcomes in different fertility policy periods and for different previous gestational ages.Methods:We used individual data from China’s National Maternal Near Miss Surveillance System between 2014 and 2019.Multivariable Poisson models with restricted cubic splines were used.Each adverse outcome was analyzed separately in the overall model and stratified models.The stratified models included different categories of fertility policy periods(2014-2015,2016-2017,and 2018-2019)and infant gestational age in previous pregnancy(<28 weeks,28-36 weeks,and≥37 weeks).Results:There were 781,731 pregnancies enrolled in this study.A short IPI(≤6 months)was associated with an increased risk of preterm birth(OR[95%CI]:1.63[1.55,1.71]for vaginal delivery[VD]and 1.10[1.03,1.19]for cesarean section[CS]),low Apgar scores and small for gestational age(SGA),and a decreased risk of diabetes mellitus in pregnancy,preeclampsia or eclampsia,and gestational hypertension.A long IPI(≥60 months)was associated with an increased risk of preterm birth(OR[95%CI]:1.18[1.11,1.26]for VD and 1.39[1.32,1.47]for CS),placenta previa,postpartum hemorrhage,diabetes mellitus in pregnancy,preeclampsia or eclampsia,and gestational hypertension.Fertility policy changes had little effect on the association of IPIs and adverse maternal and neonatal outcomes.The estimated risk of preterm birth,low Apgar scores,SGA,diabetes mellitus in pregnancy,and gestational hypertension was more profound among women with previous term births than among those with preterm births or pregnancy loss.Conclusion:For pregnant women with shorter or longer IPIs,more targeted health care measures during pregnancy should be formulated according to infant gestational age in previous pregnancy.展开更多
Male infertility caused by idiopathic oligoasthenospermia(OAT)is known as idiopathic male infertility.Glutathione S-transferase(GST)and fluoride may play important roles in idiopathic male infertility,but their effect...Male infertility caused by idiopathic oligoasthenospermia(OAT)is known as idiopathic male infertility.Glutathione S-transferase(GST)and fluoride may play important roles in idiopathic male infertility,but their effects are still unknown.Our study examined the relationship between GST polymorphisms and fluoride-induced toxicity in idiopathic male infertility and determined the underlying mechanism.Sperm,blood,and urine samples were collected from 560 males.Fluoride levels were measured by a highly selective electrode method,and GST genotypes were identified using polymerase chain reaction(PCR)and PCR-restriction fragment length polymorphism(PCR-RFLP).Semen parameters,DNA fragmentation index(DFI),mitochondrial membrane potential(MMP),and oxidative stress(OS)biomarkers were statistically assessed at the P<0.05 level.Compared with healthy fertile group,semen parameters,fluoride levels,OS biomarkers,sex hormone levels,and MMP and DFI levels were lower in the idiopathic male infertility group.For glutathione S-transferase M1(GSTM1[-])and glutathione S-transferase T1(GSTT1[-])or glutathione S-transferase P1(GSTP1)mutant genotypes,levels of semen fluoride,OS,MMP,and DFI were considerably higher,and the mean levels of sperm parameters and testosterone were statistically significant in GSTM1(+),GSTT1(+),and GSTP1 wild-type genotypes.Both semen and blood fluoride levels were associated with oxidative stress in idiopathic male infertility patients.Elevated fluoride in semen with the genotypes listed above was linked to reproductive quality in idiopathic male infertility patients.In conclusion,GST polymorphisms and fluorine may have an indicative relationship between reproductive quality and sex hormone levels,and OS participates in the development of idiopathic male infertility.展开更多
What is already known about this topic?An association between prenatal heatwave exposure and the risk of preterm birth was found.However,the disparities in heatwave-related preterm birth across different climate types...What is already known about this topic?An association between prenatal heatwave exposure and the risk of preterm birth was found.However,the disparities in heatwave-related preterm birth across different climate types have not been examined.What is added by this report?This nationwide case-crossover study investigated the association between heatwave exposure and preterm birth across different Köppen-Geiger climate types.Among pregnant women residing in the arid-desertcold climate type,exposure to compound heatwaves was found to be associated with a significantly higher risk of preterm birth{adjusted odds ratios(AORs)ranged from 1.55[95%confidence interval(CI):1.21-1.97]to 2.11(95%CI:1.35-3.31)}.In contrast,among pregnant women residing in the tropical monsoonal climate type,exposure to daytime-only heatwaves was associated with an increased risk of preterm birth[AORs ranged from 1.25(95%CI:1.03-1.51)to 1.37(95%CI:1.05-1.77)].展开更多
Data sharing and searching are important functionalities in cloud storage. In this paper, we show how to securely and flexibly search and share cloud data among a group of users without a group manager. We formalize a...Data sharing and searching are important functionalities in cloud storage. In this paper, we show how to securely and flexibly search and share cloud data among a group of users without a group manager. We formalize a novel cryptosystem： secure channel free searchable encryption in a peer-to-peer group, which features with the secure cloud data sharing and searching for group members in an identity-based setting. Our scheme allows group members to join or leave the group dynamically. We present two schemes： basic scheme and enhanced scheme. We formally prove that our basic scheme achieves consistency and indistinguishability against the chosen keyword and ciphertext attack and the outsider＇s keyword guessing attack, respectively. An enhanced scheme is also proposed to achieve forward secrecy, which allows to revoke user search right over the former shared data.展开更多
The notion of searchable encrypted keywords introduced an elegant approach to retrieve encrypted data without the need of decryption. Since the introduction of this notion, there are two main searchable encrypted keyw...The notion of searchable encrypted keywords introduced an elegant approach to retrieve encrypted data without the need of decryption. Since the introduction of this notion, there are two main searchable encrypted keywords techniques, symmetric searchable encryption （SSE） and public key encryption with keyword search （PEKS）. Due to the complicated key management problem in SSE, a number of concrete PEKS constructions have been proposed to overcome it. However, the security of these PEKS schemes was only weakly defined in presence of outsider attacks;therefore they suffer from keyword guessing attacks from the database server as an insider. How to resist insider attacks remains a challenging problem. We propose the first searchable encrypted keywords against insider attacks （SEK-IA） framework to address this problem. The security model of SEK-IA under public key environment is rebuilt. We give a concrete SEK-IA construction featured with a constant-size trapdoor and the proposed scheme is formally proved to be secure against insider attacks. The performance evaluations show that the communication cost between the receiver and the server in our SEK-IA scheme remains constant, independent of the sender identity set size, and the receiver needs the minimized computational cost to generate a trapdoor to search the data from multiple senders.展开更多
With the popularity of cloud computing and mobile Apps, on-demand services such as on-line music or audio streaming and vehicle booking are widely available nowadays. In order to allow efficient delivery and managemen...With the popularity of cloud computing and mobile Apps, on-demand services such as on-line music or audio streaming and vehicle booking are widely available nowadays. In order to allow efficient delivery and management of the services, for large-scale on-demand systems, there is usually a hierarchy where the service provider can delegate its service to a top-tier （e.g., countrywide） proxy who can then further delegate the service to lower level （e.g., region-wide） proxies. Secure （re-）delegation and revocation are among the most crucial factors for such systems. In this paper, we investigate the practical solutions for achieving re-delegation and revocation utilizing proxy signature. Although proxy signature has been extensively studied in the literature, no previous solution can achieve both properties. To fill the gap, we introduce the notion of revocable and re-delegable proxy signature that supports efficient revocation and allows a proxy signer to re-delegate its signing right to other proxy signers without the interaction with the original signer. We define the formal security models for this new primitive and present an efficient scheme that can achieve all the security properties. We also present a secure on-line revocable and re-delegate vehicle ordering system （RRVOS） as one of the applications of our proposed scheme.展开更多
To explore the relationship between genetic polymorphisms of metabolic enzymes such as CYP1A1,CYP2D6,GSTM1,GSTT1,and GSTP1 and idiopathic male infertility.By observing the efficacy of antioxidants in the treatment of ...To explore the relationship between genetic polymorphisms of metabolic enzymes such as CYP1A1,CYP2D6,GSTM1,GSTT1,and GSTP1 and idiopathic male infertility.By observing the efficacy of antioxidants in the treatment of idiopathic male infertility,the effect of metabolic enzyme gene polymorphisms on antioxidant therapy in patients with idiopathic male infertility was prospectively studied.This case-control study included 310 men with idiopathic infertility and 170 healthy controls.The cytochrome P4501A1(CYP1A1),cytochrome P4502D6(CYP2D6),glutathione S-transferase M1(GSTM1),glutathione S-transferase T1(GSTT1),and glutathione S-transferase P1(GSTP1)genotypes in peripheral blood samples were analyzed by polymerase chain reaction(PCR)and PCR-restriction fragment length polymorphism(PCR-RFLP).The idiopathic male infertility group was treated with vitamin C,vitamin E,and coenzyme Q10 for 3 months and followed up for 6 months.GSTM1(-),GSTT1(-),and GSTM1/T1(-/-)in the idiopathic male infertility groups were more common than those in the control group.The sperm concentration,motility,viability,mitochondrial membrane potential(MMP),and seminal plasma total antioxidant capacity(T-AOC)level in patients with GSTM1(-),GSTT1(-),and GSTM1/T1(-/-)were lower than those in wild-type carriers,and the sperm DNA fragmentation index(DFI),8-hydroxy-2'-deoxyguanosine(8-OH-dG),and malondialdehyde(MDA)and nitric oxide(NO)levels were higher.Therefore,oxidative damage may play an important role in the occurrence and development of idiopathic male infertility,but antioxidant therapy is not effective in male infertility patients with GSTM1 and GSTT1 gene deletions.展开更多
Objective:To analyze the temporal trends of maternal mortality ratio(MMR)due to obstetric hemorrhage and its specific causes in Chinese mainland from 2000 to 2019,to identify whether the rate of change has accelerated...Objective:To analyze the temporal trends of maternal mortality ratio(MMR)due to obstetric hemorrhage and its specific causes in Chinese mainland from 2000 to 2019,to identify whether the rate of change has accelerated or slowed down during this period,and to find the prior cause of obstetric hemorrhage that needs to be intervened in the future.Methods:Individual information on maternal deaths and total number of live births from 336 surveillance sites across 31 provinces in Chinese mainland was collected from the National Maternal and Child Health Surveillance System between 2000 and 2019.Maternal death was defined according to the World Health Organization’s criterion.The final underlying cause of death was confirmed by the national review and was coded according to International Classification of Diseases-10.Linear trends for changes in characteristics of maternal deaths were assessed using linear or logistic models with the year treated as a continuous variable.The MMR and 95%confidence intervals(CI)for regions or causes were estimated by Poisson’s distribution.Joinpoint regression was used to assess the accurate temporal patterns.Results:The national MMR due to obstetric hemorrhage was 18.4 per 100,000 live births(95%CI:15.0–22.2)in 2000.It peaked in 2001(22.1 per 100,000 live births,95%CI:18.3–26.4)and was lowest in 2019(1.6 per 100,000 live births,95%CI:1.0–2.3).For specific regions,the MMR due to obstetric hemorrhage in rural areas and western regions both experienced a slight rise,followed by a rapid decline,and then a slow decline.For specific causes,no change point was found in joinpoint analysis of the national MMR caused by placenta previa,postpartum uterine atony,and retained placenta(the annual percent change was12.0%,10.5%,and21.0%,respectively).The MMR caused by postpartum hemorrhages(PPH)significantly declined by 8.0%(95%CI:1.9–13.6)per year from 2000 to 2007.The annual percent change of MMR caused by PPH accelerated further to25.0%between 2007 and 2011,and then decreased to7.8%between 2011 and 2019.The proportion of maternal deaths due to antepartum hemorrhages increased from 7.6%(8/105)in 2000 to 14.3%(4/28)in 2019.The changes in the proportion of causes were different for maternal deaths due to PPH.The proportion of postpartum uterine atony increased from 39.0%(41/105)in 2000 to 60.7%(17/28)in 2019,and the proportion of uterine rupture also increased from 12.3%(13/105)in 2000 to 14.3%(4/28)in 2019.However,the proportion of retained placenta decreased from 37.1%(39/105)in 2000 to 7.1%(2/28)in 2019.Conclusion:Over the last 20 years,the intervention practice in China has proved that targeted interventions are beneficial in reducing the MMR due to obstetric hemorrhage.However,the MMR has reached a plateau and is likely to increase for some specific causes such as uterine rupture.China needs to develop more effective interventions to reduce maternal deaths due to obstetric hemorrhage,especially for postpartum uterine atony and uterine rupture.展开更多
Background:Zoonotic schistosomiasis,caused by Schistosoma japonicum,remains a major public health problem in the Philippines.This study aimed to evaluate the commercially available rapid diagnostic point-of-care circu...Background:Zoonotic schistosomiasis,caused by Schistosoma japonicum,remains a major public health problem in the Philippines.This study aimed to evaluate the commercially available rapid diagnostic point-of-care circulating cathodic antigen(POC-CCA)test in detecting individuals infected with S.japonicum in a human cohort from an endemic area for schistosomiasis japonica in the Philippines.Methods:Clinical samples were collectedin 18 barangays endemic for S.japonicum infection in Laoang and Palapag municipalities,Northern Samar,the Philippines,in 2015.The presence of CCA in flter-concentrated urine samples(n=412)was evaluated using the commercial kits and the results were converted to images,which were further analyzed by ImageJ software to calculate R values.The diagnostic performance of the immunochromatographic POCCCA test was compared using the Kato-Katz(KK)procedure,in-house enzyme-linked immunosorbent assays(ELISAs)and droplet digital(dd)PCR assays as reference.Results:The POC-CCA test was able to detect S.japonicum-infected individuals in the cohort with an eggs per gram of faeces(EPG)more than or equal to 10 with sensitivity/specifcity values of 63.3%/93.3%.However,the assay showed an inability to diagnose schistosomiasis japonica infections in all cohort KK-positive individuals,of which the majority had an extremely low egg burden(EPG:1–9).The prevalence of S.japonicum infection in the total cohort determined by the POC-CCA test was 12.4%,only half of that determined by the KK method(26.2%).When compared with the ELISAs and ddPCR assays as a reference,the POC-CCA assay was further shown to be a test with low sensitivity.Nevertheless,the assay exhibited signifcant positive correlations with egg burden determined by the KK technique and the target gene copy number index values determined by the ddPCR assays within the entire cohort.Conclusions:By using in silico image analysis,the POC-CCA cassette test could be converted to a quantitative assay to avoid reader-variability.Because of its low sensitivity,the commercially available POC-CCA assay had limited potential for determining the status of a S.japonicum infection in the target cohort.The assay should be applied with caution in populations where schistosome parasites(especially S.japonicum)are present at low infection intensity.展开更多
In order to tolerate possible leakage of secret keys, leakage-resilient cryptosystem models a class of attractive leakage output by allowing an adversary to provide any computable leakage function and learning the par...In order to tolerate possible leakage of secret keys, leakage-resilient cryptosystem models a class of attractive leakage output by allowing an adversary to provide any computable leakage function and learning the partial keys or other possible intemal states from the output of function. In this work, we present an adaptively secure broadcast encryption resilient to key continual leakage in the standard model. Our scheme provides the tolerance of continual leakage, in which any user can generate multiple private keys per user by periodically updating the key. We use the dual system encryption mechanism to implement the leakage resilience and adaptive security, and intrinsically set an algorithm to refresh a key and produce a same distributed new key. We also give the evaluation of the leakage bound and leakage fraction, and the simulations show that our scheme can tolerate about 71% leakage fraction with 3.34× 10^-52 failure probability in standard 80-bit security level when we adjust the leakage factor to allow the private key to be 100 Kb.展开更多
文摘With rapid development and wide application of information technology,mankind is entering into an information age.The world where people live and work has been changed to a brand new triple-dimensional space that consists of the physical world,the human society and the cyberspace.It is well known that the cyberspace is an essential environment of human existence and development and it
基金Supported by Foundation of Health Commission of Guizhou Province of China,No.gzwkj2021-211.
文摘BACKGROUND Renal involvement in lymphoma is commonly associated with widespread nodal or extranodal lymphoma.Primary renal diffuse large B-cell lymphoma is an extremely rare extranodal lymphoma,accounting for fewer than 1%of all renal masses.Interestingly,the patient in this study had a renal vein tumor thrombus that was observed after laparoscopic radical nephrectomy.CASE SUMMARY We report the case of a 56-year-old female patient with primary renal lymphoma and a renal vein tumor thrombus whose first symptom was right pain in the back and gross hematuria.Histopathology revealed primary renal diffuse large B-cell lymphoma.The patient received 8 standard cycles of rituximab with cyclophosphamide,doxorubicin,vincristine,and prednisone chemotherapy after surgery,and no obvious signs of recurrence were observed during the one-year follow-up.CONCLUSION We evaluated comprehensive treatment of primary renal diffuse large B-cell lymphoma and multidisciplinary management of this malignancy.
文摘These years, Chinese oil painters have come to realize that they should try to tap into and representthe spirit and ideas of Chinese culture in their oil paintings. ＂Imagist oil painting＂ has thus become a common pursuit among many Chinese oil painters. To some extent, the ＂imagist＂ movement shares similarities with the expressionism in Western art tradition, both pursuing individualized and subiective artist expression. However, more directly, it draws upon the time-honored tradition of ＂freehand＂ style in Chinese painting.
基金supported by grants from the National Key Research and Development Program of China(Nos.2022YFC2704600,2022YFC2704605,2019YFC1005100)National Health Commission of the People’s Republic of China,the China Medical Board(No.11-065)+1 种基金WHO(No.CHN-12-MCN-004888)UNICEF(No.2016EJH016)
文摘Background:With an increasing proportion of multiparas,proper interpregnancy intervals(IPIs)are urgently needed.However,the association between IPIs and adverse perinatal outcomes has always been debated.This study aimed to explore the association between IPIs and adverse outcomes in different fertility policy periods and for different previous gestational ages.Methods:We used individual data from China’s National Maternal Near Miss Surveillance System between 2014 and 2019.Multivariable Poisson models with restricted cubic splines were used.Each adverse outcome was analyzed separately in the overall model and stratified models.The stratified models included different categories of fertility policy periods(2014-2015,2016-2017,and 2018-2019)and infant gestational age in previous pregnancy(<28 weeks,28-36 weeks,and≥37 weeks).Results:There were 781,731 pregnancies enrolled in this study.A short IPI(≤6 months)was associated with an increased risk of preterm birth(OR[95%CI]:1.63[1.55,1.71]for vaginal delivery[VD]and 1.10[1.03,1.19]for cesarean section[CS]),low Apgar scores and small for gestational age(SGA),and a decreased risk of diabetes mellitus in pregnancy,preeclampsia or eclampsia,and gestational hypertension.A long IPI(≥60 months)was associated with an increased risk of preterm birth(OR[95%CI]:1.18[1.11,1.26]for VD and 1.39[1.32,1.47]for CS),placenta previa,postpartum hemorrhage,diabetes mellitus in pregnancy,preeclampsia or eclampsia,and gestational hypertension.Fertility policy changes had little effect on the association of IPIs and adverse maternal and neonatal outcomes.The estimated risk of preterm birth,low Apgar scores,SGA,diabetes mellitus in pregnancy,and gestational hypertension was more profound among women with previous term births than among those with preterm births or pregnancy loss.Conclusion:For pregnant women with shorter or longer IPIs,more targeted health care measures during pregnancy should be formulated according to infant gestational age in previous pregnancy.
基金This study was supported by the National Natural Science Foundation of China(No.81660263)and the Science and Technology Fund Project of Guizhou Health Commission(No.gzwkj2021-211).
文摘Male infertility caused by idiopathic oligoasthenospermia(OAT)is known as idiopathic male infertility.Glutathione S-transferase(GST)and fluoride may play important roles in idiopathic male infertility,but their effects are still unknown.Our study examined the relationship between GST polymorphisms and fluoride-induced toxicity in idiopathic male infertility and determined the underlying mechanism.Sperm,blood,and urine samples were collected from 560 males.Fluoride levels were measured by a highly selective electrode method,and GST genotypes were identified using polymerase chain reaction(PCR)and PCR-restriction fragment length polymorphism(PCR-RFLP).Semen parameters,DNA fragmentation index(DFI),mitochondrial membrane potential(MMP),and oxidative stress(OS)biomarkers were statistically assessed at the P<0.05 level.Compared with healthy fertile group,semen parameters,fluoride levels,OS biomarkers,sex hormone levels,and MMP and DFI levels were lower in the idiopathic male infertility group.For glutathione S-transferase M1(GSTM1[-])and glutathione S-transferase T1(GSTT1[-])or glutathione S-transferase P1(GSTP1)mutant genotypes,levels of semen fluoride,OS,MMP,and DFI were considerably higher,and the mean levels of sperm parameters and testosterone were statistically significant in GSTM1(+),GSTT1(+),and GSTP1 wild-type genotypes.Both semen and blood fluoride levels were associated with oxidative stress in idiopathic male infertility patients.Elevated fluoride in semen with the genotypes listed above was linked to reproductive quality in idiopathic male infertility patients.In conclusion,GST polymorphisms and fluorine may have an indicative relationship between reproductive quality and sex hormone levels,and OS participates in the development of idiopathic male infertility.
基金Project on Mechanism-Based Precise and Integrated Strategies for Preventing and Managing Preterm Birth(2022YFC2704600,2022YFC2704605)funded by The National Key Research and Development Program of China.Public Health Issues Arising from Climate Change(grant 202046)+1 种基金funded by the Chinese Ministry of Ecology and Environment.Project on the Establishment of China-ASEAN Science and Technology Cooperation Center for Public Health(KY202101004)funded by The National Key Research and Development Program of China.
文摘What is already known about this topic?An association between prenatal heatwave exposure and the risk of preterm birth was found.However,the disparities in heatwave-related preterm birth across different climate types have not been examined.What is added by this report?This nationwide case-crossover study investigated the association between heatwave exposure and preterm birth across different Köppen-Geiger climate types.Among pregnant women residing in the arid-desertcold climate type,exposure to compound heatwaves was found to be associated with a significantly higher risk of preterm birth{adjusted odds ratios(AORs)ranged from 1.55[95%confidence interval(CI):1.21-1.97]to 2.11(95%CI:1.35-3.31)}.In contrast,among pregnant women residing in the tropical monsoonal climate type,exposure to daytime-only heatwaves was associated with an increased risk of preterm birth[AORs ranged from 1.25(95%CI:1.03-1.51)to 1.37(95%CI:1.05-1.77)].
基金This work was supported by the National Natural Science Foundation of China under Grant Nos. 61502086 and 61572115.
文摘Data sharing and searching are important functionalities in cloud storage. In this paper, we show how to securely and flexibly search and share cloud data among a group of users without a group manager. We formalize a novel cryptosystem： secure channel free searchable encryption in a peer-to-peer group, which features with the secure cloud data sharing and searching for group members in an identity-based setting. Our scheme allows group members to join or leave the group dynamically. We present two schemes： basic scheme and enhanced scheme. We formally prove that our basic scheme achieves consistency and indistinguishability against the chosen keyword and ciphertext attack and the outsider＇s keyword guessing attack, respectively. An enhanced scheme is also proposed to achieve forward secrecy, which allows to revoke user search right over the former shared data.
基金This work is supported by the National Natural Science Foundation of China under Grant Nos. 61300181 and 61502044, and the Fundamental Research Funds for the Central Universities of China under Grant No. 2015RC23.
文摘The notion of searchable encrypted keywords introduced an elegant approach to retrieve encrypted data without the need of decryption. Since the introduction of this notion, there are two main searchable encrypted keywords techniques, symmetric searchable encryption （SSE） and public key encryption with keyword search （PEKS）. Due to the complicated key management problem in SSE, a number of concrete PEKS constructions have been proposed to overcome it. However, the security of these PEKS schemes was only weakly defined in presence of outsider attacks;therefore they suffer from keyword guessing attacks from the database server as an insider. How to resist insider attacks remains a challenging problem. We propose the first searchable encrypted keywords against insider attacks （SEK-IA） framework to address this problem. The security model of SEK-IA under public key environment is rebuilt. We give a concrete SEK-IA construction featured with a constant-size trapdoor and the proposed scheme is formally proved to be secure against insider attacks. The performance evaluations show that the communication cost between the receiver and the server in our SEK-IA scheme remains constant, independent of the sender identity set size, and the receiver needs the minimized computational cost to generate a trapdoor to search the data from multiple senders.
文摘With the popularity of cloud computing and mobile Apps, on-demand services such as on-line music or audio streaming and vehicle booking are widely available nowadays. In order to allow efficient delivery and management of the services, for large-scale on-demand systems, there is usually a hierarchy where the service provider can delegate its service to a top-tier （e.g., countrywide） proxy who can then further delegate the service to lower level （e.g., region-wide） proxies. Secure （re-）delegation and revocation are among the most crucial factors for such systems. In this paper, we investigate the practical solutions for achieving re-delegation and revocation utilizing proxy signature. Although proxy signature has been extensively studied in the literature, no previous solution can achieve both properties. To fill the gap, we introduce the notion of revocable and re-delegable proxy signature that supports efficient revocation and allows a proxy signer to re-delegate its signing right to other proxy signers without the interaction with the original signer. We define the formal security models for this new primitive and present an efficient scheme that can achieve all the security properties. We also present a secure on-line revocable and re-delegate vehicle ordering system （RRVOS） as one of the applications of our proposed scheme.
基金supported by the National Natural Science Fund of China(No.81660263 and No.81300541)the China Postdo.ctoral Science Foundation(No.2015M582760XB)the Doctoral Fund of Affiliated Hospital of Guiyang Medical College(No.C-2012-6).
文摘To explore the relationship between genetic polymorphisms of metabolic enzymes such as CYP1A1,CYP2D6,GSTM1,GSTT1,and GSTP1 and idiopathic male infertility.By observing the efficacy of antioxidants in the treatment of idiopathic male infertility,the effect of metabolic enzyme gene polymorphisms on antioxidant therapy in patients with idiopathic male infertility was prospectively studied.This case-control study included 310 men with idiopathic infertility and 170 healthy controls.The cytochrome P4501A1(CYP1A1),cytochrome P4502D6(CYP2D6),glutathione S-transferase M1(GSTM1),glutathione S-transferase T1(GSTT1),and glutathione S-transferase P1(GSTP1)genotypes in peripheral blood samples were analyzed by polymerase chain reaction(PCR)and PCR-restriction fragment length polymorphism(PCR-RFLP).The idiopathic male infertility group was treated with vitamin C,vitamin E,and coenzyme Q10 for 3 months and followed up for 6 months.GSTM1(-),GSTT1(-),and GSTM1/T1(-/-)in the idiopathic male infertility groups were more common than those in the control group.The sperm concentration,motility,viability,mitochondrial membrane potential(MMP),and seminal plasma total antioxidant capacity(T-AOC)level in patients with GSTM1(-),GSTT1(-),and GSTM1/T1(-/-)were lower than those in wild-type carriers,and the sperm DNA fragmentation index(DFI),8-hydroxy-2'-deoxyguanosine(8-OH-dG),and malondialdehyde(MDA)and nitric oxide(NO)levels were higher.Therefore,oxidative damage may play an important role in the occurrence and development of idiopathic male infertility,but antioxidant therapy is not effective in male infertility patients with GSTM1 and GSTT1 gene deletions.
基金supported by the Key Research and Development Projects,Science&Technology Department of Sichuan Province(grant no.2022YFS0042).
文摘Objective:To analyze the temporal trends of maternal mortality ratio(MMR)due to obstetric hemorrhage and its specific causes in Chinese mainland from 2000 to 2019,to identify whether the rate of change has accelerated or slowed down during this period,and to find the prior cause of obstetric hemorrhage that needs to be intervened in the future.Methods:Individual information on maternal deaths and total number of live births from 336 surveillance sites across 31 provinces in Chinese mainland was collected from the National Maternal and Child Health Surveillance System between 2000 and 2019.Maternal death was defined according to the World Health Organization’s criterion.The final underlying cause of death was confirmed by the national review and was coded according to International Classification of Diseases-10.Linear trends for changes in characteristics of maternal deaths were assessed using linear or logistic models with the year treated as a continuous variable.The MMR and 95%confidence intervals(CI)for regions or causes were estimated by Poisson’s distribution.Joinpoint regression was used to assess the accurate temporal patterns.Results:The national MMR due to obstetric hemorrhage was 18.4 per 100,000 live births(95%CI:15.0–22.2)in 2000.It peaked in 2001(22.1 per 100,000 live births,95%CI:18.3–26.4)and was lowest in 2019(1.6 per 100,000 live births,95%CI:1.0–2.3).For specific regions,the MMR due to obstetric hemorrhage in rural areas and western regions both experienced a slight rise,followed by a rapid decline,and then a slow decline.For specific causes,no change point was found in joinpoint analysis of the national MMR caused by placenta previa,postpartum uterine atony,and retained placenta(the annual percent change was12.0%,10.5%,and21.0%,respectively).The MMR caused by postpartum hemorrhages(PPH)significantly declined by 8.0%(95%CI:1.9–13.6)per year from 2000 to 2007.The annual percent change of MMR caused by PPH accelerated further to25.0%between 2007 and 2011,and then decreased to7.8%between 2011 and 2019.The proportion of maternal deaths due to antepartum hemorrhages increased from 7.6%(8/105)in 2000 to 14.3%(4/28)in 2019.The changes in the proportion of causes were different for maternal deaths due to PPH.The proportion of postpartum uterine atony increased from 39.0%(41/105)in 2000 to 60.7%(17/28)in 2019,and the proportion of uterine rupture also increased from 12.3%(13/105)in 2000 to 14.3%(4/28)in 2019.However,the proportion of retained placenta decreased from 37.1%(39/105)in 2000 to 7.1%(2/28)in 2019.Conclusion:Over the last 20 years,the intervention practice in China has proved that targeted interventions are beneficial in reducing the MMR due to obstetric hemorrhage.However,the MMR has reached a plateau and is likely to increase for some specific causes such as uterine rupture.China needs to develop more effective interventions to reduce maternal deaths due to obstetric hemorrhage,especially for postpartum uterine atony and uterine rupture.
基金funded by the National Health and Medical Research Council(NHMRC)of Australia(ID:APP1160046,APP1102926,APP1037304,APP1098244,and APP1194462)DPM is a NHMRC Leadership Fellow and Senior Scientist at QIMRB.
文摘Background:Zoonotic schistosomiasis,caused by Schistosoma japonicum,remains a major public health problem in the Philippines.This study aimed to evaluate the commercially available rapid diagnostic point-of-care circulating cathodic antigen(POC-CCA)test in detecting individuals infected with S.japonicum in a human cohort from an endemic area for schistosomiasis japonica in the Philippines.Methods:Clinical samples were collectedin 18 barangays endemic for S.japonicum infection in Laoang and Palapag municipalities,Northern Samar,the Philippines,in 2015.The presence of CCA in flter-concentrated urine samples(n=412)was evaluated using the commercial kits and the results were converted to images,which were further analyzed by ImageJ software to calculate R values.The diagnostic performance of the immunochromatographic POCCCA test was compared using the Kato-Katz(KK)procedure,in-house enzyme-linked immunosorbent assays(ELISAs)and droplet digital(dd)PCR assays as reference.Results:The POC-CCA test was able to detect S.japonicum-infected individuals in the cohort with an eggs per gram of faeces(EPG)more than or equal to 10 with sensitivity/specifcity values of 63.3%/93.3%.However,the assay showed an inability to diagnose schistosomiasis japonica infections in all cohort KK-positive individuals,of which the majority had an extremely low egg burden(EPG:1–9).The prevalence of S.japonicum infection in the total cohort determined by the POC-CCA test was 12.4%,only half of that determined by the KK method(26.2%).When compared with the ELISAs and ddPCR assays as a reference,the POC-CCA assay was further shown to be a test with low sensitivity.Nevertheless,the assay exhibited signifcant positive correlations with egg burden determined by the KK technique and the target gene copy number index values determined by the ddPCR assays within the entire cohort.Conclusions:By using in silico image analysis,the POC-CCA cassette test could be converted to a quantitative assay to avoid reader-variability.Because of its low sensitivity,the commercially available POC-CCA assay had limited potential for determining the status of a S.japonicum infection in the target cohort.The assay should be applied with caution in populations where schistosome parasites(especially S.japonicum)are present at low infection intensity.
基金Acknowledgements The work was supported by the National Natural Science Foundation of China （Grant No. 61370224）, the Key Program of Natural Science Foundation of Hubei Province （2013CFA046）, and the Open Fund Program for State Key Laboratory of Information Security of China.
文摘In order to tolerate possible leakage of secret keys, leakage-resilient cryptosystem models a class of attractive leakage output by allowing an adversary to provide any computable leakage function and learning the partial keys or other possible intemal states from the output of function. In this work, we present an adaptively secure broadcast encryption resilient to key continual leakage in the standard model. Our scheme provides the tolerance of continual leakage, in which any user can generate multiple private keys per user by periodically updating the key. We use the dual system encryption mechanism to implement the leakage resilience and adaptive security, and intrinsically set an algorithm to refresh a key and produce a same distributed new key. We also give the evaluation of the leakage bound and leakage fraction, and the simulations show that our scheme can tolerate about 71% leakage fraction with 3.34× 10^-52 failure probability in standard 80-bit security level when we adjust the leakage factor to allow the private key to be 100 Kb.
