Background Sow longevity and reproductivity are essential in the modern swine industry.Although many studies have focused on the genetic and genomic factors for selection,little is known about the associations between...Background Sow longevity and reproductivity are essential in the modern swine industry.Although many studies have focused on the genetic and genomic factors for selection,little is known about the associations between the microbiome and sows with longevity in reproduction.Results In this study,we collected and sequenced rectal and vaginal swabs from 48 sows,nine of which completed up to four parities(U4P group),exhibiting reproductive longevity.We first identified predictors of sow longevity in the rectum(e.g.,Akkermansia)and vagina(e.g.,Lactobacillus)of the U4P group using RandomForest in the early breeding stage of the first parity.Interestingly,these bacteria in the U4P group showed decreased predicted KEGG gene abundance involved in the biosynthesis of amino acids.Then,we tracked the longitudinal changes of the micro-biome over four parities in the U4P sows.LEfSe analysis revealed parity-associated bacteria that existed in both the rectum and vagina(e.g.,Streptococcus in Parity 1,Lactobacillus in Parity 2,Veillonella in Parity 4).We also identi-fied patterns of bacterial change between the early breeding stage(d 0)and d 110,such as Streptococcus,which was decreased in all four parties.Furthermore,sows in the U4P group with longevity potential also showed better reproductive performance.Finally,we discovered bacterial predictors(e.g.,Prevotellaceae NK3B31 group)for the total number of piglets born throughout the four parities in both the rectum and vagina.Conclusions This study highlights how the rectal and vaginal microbiome in sows with longevity in reproduc-tion changes within four parities.The identification of parity-associated,pregnancy-related,and reproductive performance-correlated bacteria provides the foundation for targeted microbiome modulation to improve animal production.展开更多
High-precision refractive index measurement has become a research hotspot in recent years.However,traditional refractive index measurement often adopts intensity detection,whose performance is restricted by the classi...High-precision refractive index measurement has become a research hotspot in recent years.However,traditional refractive index measurement often adopts intensity detection,whose performance is restricted by the classical detection limit and is thus hard to improve further.In order to break through this limitation,we propose a quantum-enhanced refractive index sensing scheme utilizing even-coherent-state sources in combination with parity detection.In this paper,we analyze the detection performance of the proposed system.Due to the inevitable photon loss in practical applications,the effects of photon loss on resolution and sensitivity are also investigated.Numerical results show that the resolution of the proposed strategy breaks through the Rayleigh limit and achieves super-resolving refractive index measurement.Relative to existing coherent-state schemes,our strategy leads to a twofold resolution improvement.Furthermore,the physical origins of the super-resolution are analyzed.展开更多
Hybrid entangled states(HESs),which involve different particles with various degrees of freedom,have garnered significant attention and been applied in a wide range of quantum technologies.However,similar to other cat...Hybrid entangled states(HESs),which involve different particles with various degrees of freedom,have garnered significant attention and been applied in a wide range of quantum technologies.However,similar to other categories of entanglement,maximally HESs inevitably degrade to mixed states due to the environmental noise and operational imperfections.To address the degradation problem,measurement-based entanglement purification offers a feasible and robust solution alternative to conventional gate-based purification methods.In this paper,we propose a measurement-based hybrid entanglement purification protocol(MB-HEPP)for a certain kind of HES which consists of polarization photons and coherent states.We extend our methodology to several conditions,such as the multi-copy and multi-party scenarios,and the photon-loss condition.Compared with previous HEPPs,this protocol has several advantages.First,it does not depend on post-selection and the purified HESs can be retained for further application.Second,it does not require the Bell state measurement,but only uses the parity check with conventional linear optical elements,which makes it have the higher success probability and more feasible.Our MB-HEPP has potential applications in future heterogeneous quantum networks.展开更多
The unique wave-manipulation capabilities of zero-index metamaterials(ZIMs)offer a new opportunity for realizing bound states in the continuum(BICs).However,the relationship between anomalous scattering and BICs remai...The unique wave-manipulation capabilities of zero-index metamaterials(ZIMs)offer a new opportunity for realizing bound states in the continuum(BICs).However,the relationship between anomalous scattering and BICs remains underexplored when parity–time(PT)symmetry is introduced.In this work,we demonstrate that a BIC splits into a pair of lasing modes carrying opposite topological charges by introducing PT symmetry through gain-loss cylinders embedded in ZIM layers.Theoretical analysis and numerical simulations reveal that lasing and unidirectional transparency phenomena result from the singularities and exceptional points of the scattering matrix.Moreover,exceptional points can be tuned via propagation phase modulation in the air gap,and their coalescence produces quasi-BICs with symmetric responses.This work provides a framework for manipulating BICs and topological lasing modes in non-Hermitian systems,offering new insights for designing non-Hermitian photonic devices.展开更多
Aim The solvability condition for robust stabilization problem associated with a plant family P(s,δ) having parameter uncertainty δ was considered. Methods Using Youla parameterization of the stabilizers this pro...Aim The solvability condition for robust stabilization problem associated with a plant family P(s,δ) having parameter uncertainty δ was considered. Methods Using Youla parameterization of the stabilizers this problem was transformed into a strong stabilization problem associated with a related plant family G (s, δ). Results A necessary solvability condition was established in terms of the parity interlacing property of each element in G(s,δ). Another apparently necessary solvability condition is that every element in P(s,δ) must be stabilizable. Conclusion The two conditions will be compared with each other and it will be shown that every element in G(s,δ) possesses parity interlacing property if P(s,δ) is stabilizable.展开更多
As expounded in some recent mathematical conferences, this research on that amazing source of algebraic ideas known as Fermat＇s equation is aimed to prove how Fermat triples can be limited until the impossible existe...As expounded in some recent mathematical conferences, this research on that amazing source of algebraic ideas known as Fermat＇s equation is aimed to prove how Fermat triples can be limited until the impossible existence through a criterion of incompatible parities related to unexplored properties of the binomial coefficients. In this paper, the authors use a technique based on the analysis of four numbers and their internal relations with three basic compulsory factors. It leads to the practical impossibility to find any triple of natural numbers candidate to satisfy Fermat＇s equation, because when the authors try to meet a condition between parity and range the authors are compelled to violate the other one, so that they are irreducibly alternative. In particular, there is a parity violation when the authors choose all the basic factors in the allowed range and the authors obtain exceeding values of one of the involved variables when the authors try to restore the parity. Since Fermat＇s last theorem would consequently be demonstrated, many readers could recall the never found elementary proof of FLT （Fermat＇s last theorem） claimed by Pierre de Fermat. The authors are not encouraging such an interpretation because this paper is intended as a journey into Fermat＇s equation and the reader＇s attitude should be towards the algebraic achievements here proposed, with their possible hidden flaws and future developments, rather than to legendary problems like Fermat＇s riddle.展开更多
A modified Benes network is proposed to be used as an optimal shuffle network in worldwide interoperability for microwave access （WiMAX） low density parity check （LDPC） decoders, When the size of the input is not ...A modified Benes network is proposed to be used as an optimal shuffle network in worldwide interoperability for microwave access （WiMAX） low density parity check （LDPC） decoders, When the size of the input is not a power of two, the modified Benes network can achieve the most optimal performance. This modified Benes network is non-blocking and can perform any sorts of permutations, so it can support 19 modes specified in the WiMAX system. Furthermore, an efficient algorithm to generate the control signals for all the 2 × 2 switches in this network is derived, which can reduce the hardware complexity and overall latency of the modified Benes network. Synthesis results show that the proposed control signal generator can save 25.4% chip area and the overall network latency can be reduced by 36. 2%.展开更多
Postpartum hemorrhage （PPH） is one of the most adverse obstetric outcomes. Our aim is to detect the risks of multilevel PPH in different cesarean section （CS） groups [including nulliparous CS with indications, nul...Postpartum hemorrhage （PPH） is one of the most adverse obstetric outcomes. Our aim is to detect the risks of multilevel PPH in different cesarean section （CS） groups [including nulliparous CS with indications, nulliparous CS without indications, repeat cesarean （RC）, vaginal birth after cesarean （VBAC）, cesarean after vaginal birth （CAVB）]. We conducted a retrospective cohort study, and the data on 127 145 women collected from January 2014 to May 2016 and from 35 tertiary hospitals in Shanxi province, China, were reviewed. Based on the measuring results of PPH, an ordered logistic regression model was used to analyze the adjusted PPH risks for each of the CS groups, and comparisons were drawn between them. Finally, a total of 99 066 nulliparous （77.92%） and 28 079 multiparous （22.08%） women were observed. The number of CS cases was 61 117, and the rate for CS was 48.07%. A total of 10 029 women did not show indications for CS and accounted for 16.41% of the CS parturient, whereas 9103 women underwent a repeated cesarean, with a CS frequency of 14.89%. The number of VBAC cases was 989, whose rate was 9.88% in prior CS women. The number （proportions） of PPH was 3658 （2.88%） in L1 （PPH volume： ≥900 and 〈1500 mL）, 520 （0.41%） in L2 （PPH volume： ≥1500 and〈2100 mL）, and 201 （0.16%） in L3 （PPH volume： ≥2100 mL）. The Ln （n= 1, 2, 3, etc.） represented the increasing order of PPH severity. In the adjusted results, compared with spontaneous vaginal delivery （SVD） as the reference group, in the adjusted result for nulliparous, there was a decreased PPH risk in CS with indications （OR： 2.32; CI： 2.04-2.62）, which was lower than that of CS without indications （OR： 2.50; CI： 2.01-2.96）. The highest PPH risk in all subgroups （i.e. nulliparous and multiparous groups） was observed in the RC （OR： 3.61; CI： 3.16-4.17）, which was nearly twice higher than that of the VBAC （OR： 1.82; CI： 1.33-2.52）. CAVB （OR： 1.03; CI： 0.65-1.62） showed no significant difference with the reference group. Thus, we deemed that CS should be avoided in nulliparous pregnancies unless indicated, to prevent or reduce the rates for the use of RC or VBAC which are high risks of severe PPH to the parturient women.展开更多
Objectives:To describe and compare fear of childbirth and in-labor pain intensity between primiparas and multiparas and explore the association between the amount of actual pain relief and fear of childbirth.Methods:A...Objectives:To describe and compare fear of childbirth and in-labor pain intensity between primiparas and multiparas and explore the association between the amount of actual pain relief and fear of childbirth.Methods:A convenience sampling method was used.A total of 260 women undergoing spontaneous or induced labor,including 97 primiparas and 163 multiparas,were recruited in a large academic specialized hospital in Guangzhou,China,from February 2018 to August 2019.The clinical data of maternal and neonatal were extracted from a structured electronic medical record system.Other demographic information,such as employment and family monthly income,was collected by a questionnaire.The Numeric Rating Scale(NRS)and the Chinese version of the Childbirth Attitude Questionnaire(C-CAQ)were applied to assess maternal in-labor pain intensity and fear of childbirth.The analgesic consumption and the frequency of manual boluses as rescue analgesia were stored and collected from the analgesia pump.Results:Eighty-two(84.5%)primiparas and ninety-nine(60.7%)multiparas received epidural analgesia(P<0.001).In the epidural subgroup,the primiparous average fear of childbirth(36.46±10.93)was higher than that of the multiparas(32.06±10.23)(P¼0.007).However,multiparas reported more intense in-labor pain[8.0(8.0,9.0)vs.8.0(7.0,8.0)],had more successful manual boluses per hour[2.68(1.65,3.85)vs.1.77(0.90,2.47)],more hourly analgesic consumption[23.00(16.00,28.25)vs.17.24(11.52,21.36)mL]and more average analgesic consumption[0.35(0.24,0.45)vs.0.26(0.19,0.35)mL/(h$kg)]than the primiparas(P<0.05).Spearman’s correlation analysis showed that the maximum in-labor pain was weakly positively correlated with fear of childbirth(r¼0.09)(P<0.05),hourly analgesic consumption(r¼0.16)(P<0.01)and average analgesic consumption(r¼0.17)(P<0.05).No statistically significant association was uncovered between analgesic consumption and maternal fear of childbirth.Conclusions:Fear of childbirth is a potential predictor of labor pain intensity.Further study is needed to explore its role and value in pain management during delivery.Parity is not a determinant of pain relief use and should not be a preconceived preference of obstetric care team members to determine the distribution of epidural analgesia,especially when analgesia resources are insufficient.展开更多
In this paper, we focus on the design of irregular QC-LDPC code based multi-level coded modulation(MLCM) scheme by jointly optimizing the component code rate and the degree distribution of the irregular QC-LDPC compon...In this paper, we focus on the design of irregular QC-LDPC code based multi-level coded modulation(MLCM) scheme by jointly optimizing the component code rate and the degree distribution of the irregular QC-LDPC component code. Firstly, the sub-channel capacities of MLCM systems is analyzed and discussed, based on which the optimal component code rate can be obtained. Secondly, an extrinsic information transfer chart based two-stage searching algorithm is proposed to find the good irregular QC-LDPC code ensembles with optimal component code rates for their corresponding sub-channels. Finally, by constructing the irregular QC-LDPC component codes from the designed ensembles with the aim of possibly enlarging the girth and reducing the number of the shortest cycles, the designed irregular QC-LDPC code based 16QAM and 64QAM MLCM systems can achieve 0.4 dB and 1.2 dB net coding gain, respectively, compared with the recently proposed regular QC-LDPC code based 16QAM and 64QAM MLCM systems.展开更多
The key issue in accelerating method of characteristics(MOC)transport calculations is in obtaining a completely equivalent low-order neutron transport or diffusion equation.Herein,an equivalent low-order angular flux ...The key issue in accelerating method of characteristics(MOC)transport calculations is in obtaining a completely equivalent low-order neutron transport or diffusion equation.Herein,an equivalent low-order angular flux nonlinear finite difference equation is proposed for MOC transport calculations.This method comprises three essential features:(1)the even parity discrete ordinates method is used to build a low-order angular flux nonlinear finite difference equation,and different boundary condition treatments are proposed;(2)two new defined factors,i.e.,the even parity discontinuity factor and odd parity discontinuity factor,are strictly defined to achieve equivalence between the low-order angular flux nonlinear finite difference method and MOC transport calculation;(3)the energy group and angle are decoupled to construct a symmetric linear system that is much easier to solve.The equivalence of this low-order angular flux nonlinear finite difference equation is analyzed for two-dimensional(2D)pin,2D assembly,and 2D C5G7 benchmark problems.Numerical results demonstrate that a low-order angular flux nonlinear finite difference equation that is completely equivalent to the pin-resolved transport equation is established.展开更多
In a quantum key distribution（QKD） system, the error rate needs to be estimated for determining the joint probability distribution between legitimate parties, and for improving the performance of key reconciliation....In a quantum key distribution（QKD） system, the error rate needs to be estimated for determining the joint probability distribution between legitimate parties, and for improving the performance of key reconciliation. We propose an efficient error estimation scheme for QKD, which is called parity comparison method（PCM）. In the proposed method, the parity of a group of sifted keys is practically analysed to estimate the quantum bit error rate instead of using the traditional key sampling. From the simulation results, the proposed method evidently improves the accuracy and decreases revealed information in most realistic application situations.展开更多
Fault diagnosis is a key issue of the CCBII(computer controlled brake II) braking system, because the CCBII braking system is very complicated and nonlinear, which may exhibit isolated and multi-component coupled faul...Fault diagnosis is a key issue of the CCBII(computer controlled brake II) braking system, because the CCBII braking system is very complicated and nonlinear, which may exhibit isolated and multi-component coupled faults. A parity space-based method was proposed for fault diagnosis of CCBII braking systems. Firstly, the mathematical models were established according to three function modules of CCBII braking systems where the air fluid theory was utilized. Then, parity vector and threshold function were designed for each output of the system so as to identify more system faults. Fault character matrix was built based on the causal relationship between the output and the fault according to the system function and internal structure. Finally, fault detection and isolation can be realized by the comparison of the observed system output and the fault character matrix. Simulation results show that the proposed method is entirely feasible and effective.展开更多
基金funded by the National Key Research and Development Program of China (2023YFE0124400)the Specific university discipline construction project (2023B10564001)+1 种基金grants administered by the Arkansas Biosciences Institute and the USDAa core grant (P20GM121293, proteogenomics core)。
文摘Background Sow longevity and reproductivity are essential in the modern swine industry.Although many studies have focused on the genetic and genomic factors for selection,little is known about the associations between the microbiome and sows with longevity in reproduction.Results In this study,we collected and sequenced rectal and vaginal swabs from 48 sows,nine of which completed up to four parities(U4P group),exhibiting reproductive longevity.We first identified predictors of sow longevity in the rectum(e.g.,Akkermansia)and vagina(e.g.,Lactobacillus)of the U4P group using RandomForest in the early breeding stage of the first parity.Interestingly,these bacteria in the U4P group showed decreased predicted KEGG gene abundance involved in the biosynthesis of amino acids.Then,we tracked the longitudinal changes of the micro-biome over four parities in the U4P sows.LEfSe analysis revealed parity-associated bacteria that existed in both the rectum and vagina(e.g.,Streptococcus in Parity 1,Lactobacillus in Parity 2,Veillonella in Parity 4).We also identi-fied patterns of bacterial change between the early breeding stage(d 0)and d 110,such as Streptococcus,which was decreased in all four parties.Furthermore,sows in the U4P group with longevity potential also showed better reproductive performance.Finally,we discovered bacterial predictors(e.g.,Prevotellaceae NK3B31 group)for the total number of piglets born throughout the four parities in both the rectum and vagina.Conclusions This study highlights how the rectal and vaginal microbiome in sows with longevity in reproduc-tion changes within four parities.The identification of parity-associated,pregnancy-related,and reproductive performance-correlated bacteria provides the foundation for targeted microbiome modulation to improve animal production.
文摘High-precision refractive index measurement has become a research hotspot in recent years.However,traditional refractive index measurement often adopts intensity detection,whose performance is restricted by the classical detection limit and is thus hard to improve further.In order to break through this limitation,we propose a quantum-enhanced refractive index sensing scheme utilizing even-coherent-state sources in combination with parity detection.In this paper,we analyze the detection performance of the proposed system.Due to the inevitable photon loss in practical applications,the effects of photon loss on resolution and sensitivity are also investigated.Numerical results show that the resolution of the proposed strategy breaks through the Rayleigh limit and achieves super-resolving refractive index measurement.Relative to existing coherent-state schemes,our strategy leads to a twofold resolution improvement.Furthermore,the physical origins of the super-resolution are analyzed.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12175106 and 92365110)the Postgraduate Research and Practice Innovation Program of Jiangsu Province(Grant No.KYCX23-1028)。
文摘Hybrid entangled states(HESs),which involve different particles with various degrees of freedom,have garnered significant attention and been applied in a wide range of quantum technologies.However,similar to other categories of entanglement,maximally HESs inevitably degrade to mixed states due to the environmental noise and operational imperfections.To address the degradation problem,measurement-based entanglement purification offers a feasible and robust solution alternative to conventional gate-based purification methods.In this paper,we propose a measurement-based hybrid entanglement purification protocol(MB-HEPP)for a certain kind of HES which consists of polarization photons and coherent states.We extend our methodology to several conditions,such as the multi-copy and multi-party scenarios,and the photon-loss condition.Compared with previous HEPPs,this protocol has several advantages.First,it does not depend on post-selection and the purified HESs can be retained for further application.Second,it does not require the Bell state measurement,but only uses the parity check with conventional linear optical elements,which makes it have the higher success probability and more feasible.Our MB-HEPP has potential applications in future heterogeneous quantum networks.
基金supported by the National Natural Science Foundation of China(Grant Nos.12504361,12274313,and 62465005)the Natural Science Foundation of Guangxi(Grant No.2025GXNSFBA069179)the Guangxi Colleges and Universities Young and Middle-aged Teachers’Basic Scientific Research Ability Enhancement Project(Grant No.2025KY0093)。
文摘The unique wave-manipulation capabilities of zero-index metamaterials(ZIMs)offer a new opportunity for realizing bound states in the continuum(BICs).However,the relationship between anomalous scattering and BICs remains underexplored when parity–time(PT)symmetry is introduced.In this work,we demonstrate that a BIC splits into a pair of lasing modes carrying opposite topological charges by introducing PT symmetry through gain-loss cylinders embedded in ZIM layers.Theoretical analysis and numerical simulations reveal that lasing and unidirectional transparency phenomena result from the singularities and exceptional points of the scattering matrix.Moreover,exceptional points can be tuned via propagation phase modulation in the air gap,and their coalescence produces quasi-BICs with symmetric responses.This work provides a framework for manipulating BICs and topological lasing modes in non-Hermitian systems,offering new insights for designing non-Hermitian photonic devices.
文摘Aim The solvability condition for robust stabilization problem associated with a plant family P(s,δ) having parameter uncertainty δ was considered. Methods Using Youla parameterization of the stabilizers this problem was transformed into a strong stabilization problem associated with a related plant family G (s, δ). Results A necessary solvability condition was established in terms of the parity interlacing property of each element in G(s,δ). Another apparently necessary solvability condition is that every element in P(s,δ) must be stabilizable. Conclusion The two conditions will be compared with each other and it will be shown that every element in G(s,δ) possesses parity interlacing property if P(s,δ) is stabilizable.
文摘As expounded in some recent mathematical conferences, this research on that amazing source of algebraic ideas known as Fermat＇s equation is aimed to prove how Fermat triples can be limited until the impossible existence through a criterion of incompatible parities related to unexplored properties of the binomial coefficients. In this paper, the authors use a technique based on the analysis of four numbers and their internal relations with three basic compulsory factors. It leads to the practical impossibility to find any triple of natural numbers candidate to satisfy Fermat＇s equation, because when the authors try to meet a condition between parity and range the authors are compelled to violate the other one, so that they are irreducibly alternative. In particular, there is a parity violation when the authors choose all the basic factors in the allowed range and the authors obtain exceeding values of one of the involved variables when the authors try to restore the parity. Since Fermat＇s last theorem would consequently be demonstrated, many readers could recall the never found elementary proof of FLT （Fermat＇s last theorem） claimed by Pierre de Fermat. The authors are not encouraging such an interpretation because this paper is intended as a journey into Fermat＇s equation and the reader＇s attitude should be towards the algebraic achievements here proposed, with their possible hidden flaws and future developments, rather than to legendary problems like Fermat＇s riddle.
基金The National Natural Science Foundation of China(No.60871079)
文摘A modified Benes network is proposed to be used as an optimal shuffle network in worldwide interoperability for microwave access （WiMAX） low density parity check （LDPC） decoders, When the size of the input is not a power of two, the modified Benes network can achieve the most optimal performance. This modified Benes network is non-blocking and can perform any sorts of permutations, so it can support 19 modes specified in the WiMAX system. Furthermore, an efficient algorithm to generate the control signals for all the 2 × 2 switches in this network is derived, which can reduce the hardware complexity and overall latency of the modified Benes network. Synthesis results show that the proposed control signal generator can save 25.4% chip area and the overall network latency can be reduced by 36. 2%.
基金This study was supported by the National Natural Science Foundation of China （No. 71173081）.
文摘Postpartum hemorrhage （PPH） is one of the most adverse obstetric outcomes. Our aim is to detect the risks of multilevel PPH in different cesarean section （CS） groups [including nulliparous CS with indications, nulliparous CS without indications, repeat cesarean （RC）, vaginal birth after cesarean （VBAC）, cesarean after vaginal birth （CAVB）]. We conducted a retrospective cohort study, and the data on 127 145 women collected from January 2014 to May 2016 and from 35 tertiary hospitals in Shanxi province, China, were reviewed. Based on the measuring results of PPH, an ordered logistic regression model was used to analyze the adjusted PPH risks for each of the CS groups, and comparisons were drawn between them. Finally, a total of 99 066 nulliparous （77.92%） and 28 079 multiparous （22.08%） women were observed. The number of CS cases was 61 117, and the rate for CS was 48.07%. A total of 10 029 women did not show indications for CS and accounted for 16.41% of the CS parturient, whereas 9103 women underwent a repeated cesarean, with a CS frequency of 14.89%. The number of VBAC cases was 989, whose rate was 9.88% in prior CS women. The number （proportions） of PPH was 3658 （2.88%） in L1 （PPH volume： ≥900 and 〈1500 mL）, 520 （0.41%） in L2 （PPH volume： ≥1500 and〈2100 mL）, and 201 （0.16%） in L3 （PPH volume： ≥2100 mL）. The Ln （n= 1, 2, 3, etc.） represented the increasing order of PPH severity. In the adjusted results, compared with spontaneous vaginal delivery （SVD） as the reference group, in the adjusted result for nulliparous, there was a decreased PPH risk in CS with indications （OR： 2.32; CI： 2.04-2.62）, which was lower than that of CS without indications （OR： 2.50; CI： 2.01-2.96）. The highest PPH risk in all subgroups （i.e. nulliparous and multiparous groups） was observed in the RC （OR： 3.61; CI： 3.16-4.17）, which was nearly twice higher than that of the VBAC （OR： 1.82; CI： 1.33-2.52）. CAVB （OR： 1.03; CI： 0.65-1.62） showed no significant difference with the reference group. Thus, we deemed that CS should be avoided in nulliparous pregnancies unless indicated, to prevent or reduce the rates for the use of RC or VBAC which are high risks of severe PPH to the parturient women.
文摘Objectives:To describe and compare fear of childbirth and in-labor pain intensity between primiparas and multiparas and explore the association between the amount of actual pain relief and fear of childbirth.Methods:A convenience sampling method was used.A total of 260 women undergoing spontaneous or induced labor,including 97 primiparas and 163 multiparas,were recruited in a large academic specialized hospital in Guangzhou,China,from February 2018 to August 2019.The clinical data of maternal and neonatal were extracted from a structured electronic medical record system.Other demographic information,such as employment and family monthly income,was collected by a questionnaire.The Numeric Rating Scale(NRS)and the Chinese version of the Childbirth Attitude Questionnaire(C-CAQ)were applied to assess maternal in-labor pain intensity and fear of childbirth.The analgesic consumption and the frequency of manual boluses as rescue analgesia were stored and collected from the analgesia pump.Results:Eighty-two(84.5%)primiparas and ninety-nine(60.7%)multiparas received epidural analgesia(P<0.001).In the epidural subgroup,the primiparous average fear of childbirth(36.46±10.93)was higher than that of the multiparas(32.06±10.23)(P¼0.007).However,multiparas reported more intense in-labor pain[8.0(8.0,9.0)vs.8.0(7.0,8.0)],had more successful manual boluses per hour[2.68(1.65,3.85)vs.1.77(0.90,2.47)],more hourly analgesic consumption[23.00(16.00,28.25)vs.17.24(11.52,21.36)mL]and more average analgesic consumption[0.35(0.24,0.45)vs.0.26(0.19,0.35)mL/(h$kg)]than the primiparas(P<0.05).Spearman’s correlation analysis showed that the maximum in-labor pain was weakly positively correlated with fear of childbirth(r¼0.09)(P<0.05),hourly analgesic consumption(r¼0.16)(P<0.01)and average analgesic consumption(r¼0.17)(P<0.05).No statistically significant association was uncovered between analgesic consumption and maternal fear of childbirth.Conclusions:Fear of childbirth is a potential predictor of labor pain intensity.Further study is needed to explore its role and value in pain management during delivery.Parity is not a determinant of pain relief use and should not be a preconceived preference of obstetric care team members to determine the distribution of epidural analgesia,especially when analgesia resources are insufficient.
基金supported by National Natural Science Foundation of China(No.61571061)
文摘In this paper, we focus on the design of irregular QC-LDPC code based multi-level coded modulation(MLCM) scheme by jointly optimizing the component code rate and the degree distribution of the irregular QC-LDPC component code. Firstly, the sub-channel capacities of MLCM systems is analyzed and discussed, based on which the optimal component code rate can be obtained. Secondly, an extrinsic information transfer chart based two-stage searching algorithm is proposed to find the good irregular QC-LDPC code ensembles with optimal component code rates for their corresponding sub-channels. Finally, by constructing the irregular QC-LDPC component codes from the designed ensembles with the aim of possibly enlarging the girth and reducing the number of the shortest cycles, the designed irregular QC-LDPC code based 16QAM and 64QAM MLCM systems can achieve 0.4 dB and 1.2 dB net coding gain, respectively, compared with the recently proposed regular QC-LDPC code based 16QAM and 64QAM MLCM systems.
基金the National Key R&D Program of China(No.2018YFE0180900).
文摘The key issue in accelerating method of characteristics(MOC)transport calculations is in obtaining a completely equivalent low-order neutron transport or diffusion equation.Herein,an equivalent low-order angular flux nonlinear finite difference equation is proposed for MOC transport calculations.This method comprises three essential features:(1)the even parity discrete ordinates method is used to build a low-order angular flux nonlinear finite difference equation,and different boundary condition treatments are proposed;(2)two new defined factors,i.e.,the even parity discontinuity factor and odd parity discontinuity factor,are strictly defined to achieve equivalence between the low-order angular flux nonlinear finite difference method and MOC transport calculation;(3)the energy group and angle are decoupled to construct a symmetric linear system that is much easier to solve.The equivalence of this low-order angular flux nonlinear finite difference equation is analyzed for two-dimensional(2D)pin,2D assembly,and 2D C5G7 benchmark problems.Numerical results demonstrate that a low-order angular flux nonlinear finite difference equation that is completely equivalent to the pin-resolved transport equation is established.
基金Project supported by the National Basic Research Program of China(Grant Nos.2011CBA00200 and 2011CB921200)the National Natural Science Foundation of China(Grant Nos.61101137,61201239,and 61205118)
文摘In a quantum key distribution（QKD） system, the error rate needs to be estimated for determining the joint probability distribution between legitimate parties, and for improving the performance of key reconciliation. We propose an efficient error estimation scheme for QKD, which is called parity comparison method（PCM）. In the proposed method, the parity of a group of sifted keys is practically analysed to estimate the quantum bit error rate instead of using the traditional key sampling. From the simulation results, the proposed method evidently improves the accuracy and decreases revealed information in most realistic application situations.
基金Projects(61071096,61073103,61003233) supported by the National Natural Science Foundation of ChinaProjects(20100162110012,20110162110042) supported by Doctoral Program of Higher Education,China
文摘Fault diagnosis is a key issue of the CCBII(computer controlled brake II) braking system, because the CCBII braking system is very complicated and nonlinear, which may exhibit isolated and multi-component coupled faults. A parity space-based method was proposed for fault diagnosis of CCBII braking systems. Firstly, the mathematical models were established according to three function modules of CCBII braking systems where the air fluid theory was utilized. Then, parity vector and threshold function were designed for each output of the system so as to identify more system faults. Fault character matrix was built based on the causal relationship between the output and the fault according to the system function and internal structure. Finally, fault detection and isolation can be realized by the comparison of the observed system output and the fault character matrix. Simulation results show that the proposed method is entirely feasible and effective.
