BACKGROUND Prevotella oris-induced meningitis and Prevotella oris-induced meningitis concomitant with spinal canal infection are extremely rare.To the best of our knowledge,only 1 case of Prevotella oris-induced centr...BACKGROUND Prevotella oris-induced meningitis and Prevotella oris-induced meningitis concomitant with spinal canal infection are extremely rare.To the best of our knowledge,only 1 case of Prevotella oris-induced central system infection has been reported.This is the second report on meningitis combined with spinal canal infection due to Prevotella oris.CASE SUMMARY We report a case of a 9-year-old boy suffering from meningitis and spinal canal infection.The patient presented to the neurosurgery department with lumbosacral pain for 1 mo and headache and vomiting for 1 d.He had been treated with cephalosporin and nonsteroidal anti-inflammatory drugs for fever,otalgia and pharyngalgia in a local hospital 2 mo prior to this admission.During hospitalization,magnetic resonance imaging suggested meningitis and L3-S1 lumbosacral dural sac infection.The cerebrospinal fluid and blood cultures were negative,but the cerebrospinal fluid specimen indicated the presence of Prevotella oris by metagenomic next-generation sequencing.Previous cases of Prevotella oris infection were retrieved from PubMed to characterize the clinicopathological features and identify the prognostic factors and related antimicrobial treatment of infection due to Prevotella oris.CONCLUSION This report shed light on the characteristics of Prevotella oris infection and highlighted the role of metagenomic next-generation sequencing in pathogen detection.展开更多
This paper studies the finite element method for some nonlinear hyperbolic partial differential equations with memory and dampling terms.A Crank\|Nicolson approximation for this kind of equations is presented.By using...This paper studies the finite element method for some nonlinear hyperbolic partial differential equations with memory and dampling terms.A Crank\|Nicolson approximation for this kind of equations is presented.By using the elliptic Ritz\|Volterra projection,the analysis of the error estimates for the finite element numerical solutions and the optimal H \+1\|norm error estimate are demonstrated.展开更多
The geometrical structures, relative stabilities, electronic and magnetic properties of small BnAl-（2〈n〈9）clusters are systematicalyy investigated by using the first-principles density functional theory. The resul...The geometrical structures, relative stabilities, electronic and magnetic properties of small BnAl-（2〈n〈9）clusters are systematicalyy investigated by using the first-principles density functional theory. The results show that the A1 atom prefers to reside either on the outer-side or above the surface, but not in the centre of the clusters in all of the most stable BnAl-（2〈n〈9） isomers and the one excess electron is strong enough to modify the geometries of some specific sizes of the neutral clusters. All the results of the analysis for the fragmentation energies, the second-order difference of energies, and the highest occupied-lowest unoccupied molecular orbital energy gaps show that B4A1- and B8A1- clusters each have a higher relative stability. Especially, the BsA1-cluster has the most enhanced chemical stability. Furthermore, both the local magnetic moments and the total magnetic moments display a pronounced oddeven oscillation with the number of boron atoms, and the magnetic effects arise mainly from the boron atoms except for the B7A1- and BgA1- clusters.展开更多
A SYMMETRIC crying facies(ACF)is characterized by facial asymmetry only when crying.It may present as an exclusive symptom,or be concomitant with other congenital malformations and even some fatal birth defects.Clinic...A SYMMETRIC crying facies(ACF)is characterized by facial asymmetry only when crying.It may present as an exclusive symptom,or be concomitant with other congenital malformations and even some fatal birth defects.Clinically,ACF is featured by drooping of the intact corner of the mouth during crying,while the face appears symmetric展开更多
In an extensional shear zone in the Talea Ori, Crete, quartz veins occur in high-pressure low-temperature metamorphic sediments at sites of dilation along shear band boundaries, kink band boundaries and boudin necks. ...In an extensional shear zone in the Talea Ori, Crete, quartz veins occur in high-pressure low-temperature metamorphic sediments at sites of dilation along shear band boundaries, kink band boundaries and boudin necks. Bent elongate grains grown epitactically from the host rock with abundant fluid inclusion trails parallel to the vein wall indicate vein formation by crack-seal increments during dissolutionprecipitation creep of the host rock. The presence of sutured high-angle grain boundaries and subgrains shows that temperatures were sufficiently high for recovery and strain-induced grain boundary migration, i.e. higher than 300 -350℃, close to peak metamorphic conditions. The generally low amount of strain accumulated by dislocation creep in quartz of the host rock and most veins indicates low bulk stress conditions of a few tens of MPa on a long term. The time scale of stress-loading to cause cyclic cracking and sealing is assumed to be lower than the Maxwell relaxation time of the metasediments undergoing dissolution-precipitation creep at high strain rates(10^(-10) s^(-1) to 10^(-9) s^(-1)), which is on the order of hundred years. In contrast, some veins discordant or concordant to the foliation show heterogeneous quartz microstructures with micro-shear zones, sub-basal deformation lamellae, shortwavelength undulatory extinction and recrystallized grains restricted to high strain zones. These microstructures indicate dislocation glide-controlled crystal-plastic deformation(low-temperature plasticity) at transient high stresses of a few hundred MPa with subsequent recovery and strain-induced grain boundary migration at relaxing stresses and temperatures of at least 300 -350℃. High differential stresses in rocks at greenschist-facies conditions that relieve stress by creep on the long term, requires fast stress-loading rates, presumably by seismic activity in the overlying upper crust. The time scale for stress loading is controlled by the duration of the slip event along a fault, i.e. a few seconds to minutes.This study demonstrates that microstructures can distinguish between deformation at internal low stress-loading rates(to tens of MPa on a time scale of hundred years) and high(coseismic) stress-loading rates to a few hundred MPa on a time scale of minutes.展开更多
A photometric analysis and evolutionary stages of the contact binary V2790 Ori are presented.The BV RC observations were carried out at the Thai National Observatory. The photometric light curves were fitted to provid...A photometric analysis and evolutionary stages of the contact binary V2790 Ori are presented.The BV RC observations were carried out at the Thai National Observatory. The photometric light curves were fitted to provide fundamental parameters, required to examine evolutionary stages of the binary. The results indicate that V2790 Ori is a W-type contact system with a mass ratio of q = 2.932. The orbital period increase is found at a rate of d P/dt = 1.03×10^-7 d yr^-1. This implies that a rate of mass transfer from the secondary component to the primary one is dm2/dt =6.31×10^-8 M⊙yr^-1. Furthermore, we find that from the detached phase to the contact phase, the amount of mass that the evolved secondary component has lost is 1.188±0.110 M⊙, i.e., mass lost by the system is 0.789±0.073 M⊙and mass transfer to the primary is0.399±0.037 M⊙. Since the time of the first overflow, the angular momentum loss is found to be 72.2% of JFOF, causing the orbit and Roche surface to shrink until the present time.展开更多
一、服务型政府的涵义、基本特征(一)服务型政府的涵义对于"服务型政府"的称谓,学者们的提法不一致,诸如,公共服务取向模式、新公共服务政府、现代的服务型政府、新型的服务型政府等。英国学者E?费利耶认为,在当代西方政府改...一、服务型政府的涵义、基本特征(一)服务型政府的涵义对于"服务型政府"的称谓,学者们的提法不一致,诸如,公共服务取向模式、新公共服务政府、现代的服务型政府、新型的服务型政府等。英国学者E?费利耶认为,在当代西方政府改革运动中,至少有四种不同于传统的公共行政模式的新公共管理模式,公共服务取向模式(Public Service Orientation)展开更多
This paper is devoted to binary stars belonging to the class of eclipsing-variable systems.Photometric and spectroscopic analysis of eclipses allows us to determine geometric parameters of the orbit and physical chara...This paper is devoted to binary stars belonging to the class of eclipsing-variable systems.Photometric and spectroscopic analysis of eclipses allows us to determine geometric parameters of the orbit and physical characteristics of stellar components as well as inclinations of stellar equators to the orbital plane. Estimations of inclinations can be obtained from measurement of the Rossiter-McLaughlin effect, which is discussed using examples of some eccentric binaries with an anomalous apsidal effect. Our task is to find the complete spectrum of solutions of the equation of apsidal motion, depending on the inclinations of the polar axes of the components to the orbital one for these systems, based on their individual spectroscopic and photometric observational data. The matrix of solutions allows us to select those pairs of polar inclinations that provide agreement with the observational apsidal period.展开更多
Four-color charge-coupled device(CCD) light curves in the B, V, Rc and I c bands of the totaleclipsing binary system V1853 Orionis(V1853 Ori) are presented. By comparing our light curves with those published by previo...Four-color charge-coupled device(CCD) light curves in the B, V, Rc and I c bands of the totaleclipsing binary system V1853 Orionis(V1853 Ori) are presented. By comparing our light curves with those published by previous investigators, it is determined that the O'Connell effect on the light curves has disappeared. By analyzing those multi-color light curves with the Wilson-Devinney code(W-D code),it is discovered that V1853 Ori is an A-type intermediate-contact binary with a degree of contact factor of f = 33.3%(3.7%) and a mass ratio of q = 0.1896(0.0013). Combining our 10 newly determined times of light minima together with others published in the literature, the period changes of the system are investigated. We found that the general trend of the observed minus calculated(O-C) curve shows a downward parabolic variation that corresponds to a long-term decrease in the orbital period with a rate of d P/dt =-1.96(0.46)×10^(-7) d yr^(-1). The long-term period decrease could be explained by mass transfer from the more-massive component to the less-massive one. By combining our photometric solutions with data from Gaia DR_2, absolute parameters were derived as M_1 = 1.20 M⊙, M_2 = 0.23 M⊙, R_1 = 1.36 R⊙and R_2 = 0.66 R⊙. The long-term period decrease and intermediate-contact configuration suggest that V1853 Ori will evolve into a high fill-out overcontact binary.展开更多
We present new photometry for two contact binaries,Y Sex and V1363 Ori,which were observed by three small telescopes in China.By using the W-D method,the absolute parameters are updated from new BVR light curves and p...We present new photometry for two contact binaries,Y Sex and V1363 Ori,which were observed by three small telescopes in China.By using the W-D method,the absolute parameters are updated from new BVR light curves and previous radial velocity curves.Results identify that two binaries are deep,lowmass ratio(DLMR)overcontact binaries with q≤0.25 and f≥50%.From the temperature-luminosity diagram,the primary components are slightly evolved main-sequence stars,whose evolutionary ages are~2.51 Gyr for Y Sex and~3.56 Gyr for V 1363 Ori,respectively.From the(O-C)curves,it is found that the orbital periods may be undergoing secular increase with cyclic variations,which may be interpreted either by magnetic activity cycles or by the light-time orbit effect.With period increasing,this kind of DLMR overcontact binaries,such as Y Sex and V1363 Ori,will evolve into the rapid-rotating single stars.展开更多
The first photometric solution in the B,V,R_(c) and I_(c) filters of the short period V1833 Ori eclipsing binary is presented based on new ground-based CCD photometric observations.We analyzed the BVRI photometric lig...The first photometric solution in the B,V,R_(c) and I_(c) filters of the short period V1833 Ori eclipsing binary is presented based on new ground-based CCD photometric observations.We analyzed the BVRI photometric light curves of the system,using PHOEBE 0.31 a,a binary star modeling program,with the Wilson-Devinney method based on Roche geometry to achieve the best accordance with the photometric observations to determine their absolute parameters from the light curves.We updated the ephemeris of V1833 Ori using two new light curve minima derived by our new observational data from those collected in the literature and analyzed the change of the system's orbital period.The O-C analysis indicates that the variations of the orbital period of V1833 Ori with time are increasing at a rate of 3.03×10^(-7)days yr^(-1).The distance of V1833 Ori is 173.7±15.6 pc.From the solutions,we find that V1833 Ori is an A-subtype W UMa overcontact binary with q=0.701 mass ratio and f=1.14 fill-out factor.The HR diagram positions of the eclipsing binary system's components are discussed.The system's absolute dimensions were compared to those of similar binaries in the log T_(eff)-log L,logM-logL,1 ogM-logR and logM-log J_(0)diagrams.展开更多
文摘BACKGROUND Prevotella oris-induced meningitis and Prevotella oris-induced meningitis concomitant with spinal canal infection are extremely rare.To the best of our knowledge,only 1 case of Prevotella oris-induced central system infection has been reported.This is the second report on meningitis combined with spinal canal infection due to Prevotella oris.CASE SUMMARY We report a case of a 9-year-old boy suffering from meningitis and spinal canal infection.The patient presented to the neurosurgery department with lumbosacral pain for 1 mo and headache and vomiting for 1 d.He had been treated with cephalosporin and nonsteroidal anti-inflammatory drugs for fever,otalgia and pharyngalgia in a local hospital 2 mo prior to this admission.During hospitalization,magnetic resonance imaging suggested meningitis and L3-S1 lumbosacral dural sac infection.The cerebrospinal fluid and blood cultures were negative,but the cerebrospinal fluid specimen indicated the presence of Prevotella oris by metagenomic next-generation sequencing.Previous cases of Prevotella oris infection were retrieved from PubMed to characterize the clinicopathological features and identify the prognostic factors and related antimicrobial treatment of infection due to Prevotella oris.CONCLUSION This report shed light on the characteristics of Prevotella oris infection and highlighted the role of metagenomic next-generation sequencing in pathogen detection.
文摘This paper studies the finite element method for some nonlinear hyperbolic partial differential equations with memory and dampling terms.A Crank\|Nicolson approximation for this kind of equations is presented.By using the elliptic Ritz\|Volterra projection,the analysis of the error estimates for the finite element numerical solutions and the optimal H \+1\|norm error estimate are demonstrated.
基金supported by the National Natural Science Foundation of China (Grant Nos. 10974139 and 10964002) the Doctoral Program Foundation of the Institution of Higher Education of China (Grant No. 20050610010)
文摘The geometrical structures, relative stabilities, electronic and magnetic properties of small BnAl-（2〈n〈9）clusters are systematicalyy investigated by using the first-principles density functional theory. The results show that the A1 atom prefers to reside either on the outer-side or above the surface, but not in the centre of the clusters in all of the most stable BnAl-（2〈n〈9） isomers and the one excess electron is strong enough to modify the geometries of some specific sizes of the neutral clusters. All the results of the analysis for the fragmentation energies, the second-order difference of energies, and the highest occupied-lowest unoccupied molecular orbital energy gaps show that B4A1- and B8A1- clusters each have a higher relative stability. Especially, the BsA1-cluster has the most enhanced chemical stability. Furthermore, both the local magnetic moments and the total magnetic moments display a pronounced oddeven oscillation with the number of boron atoms, and the magnetic effects arise mainly from the boron atoms except for the B7A1- and BgA1- clusters.
文摘A SYMMETRIC crying facies(ACF)is characterized by facial asymmetry only when crying.It may present as an exclusive symptom,or be concomitant with other congenital malformations and even some fatal birth defects.Clinically,ACF is featured by drooping of the intact corner of the mouth during crying,while the face appears symmetric
基金funded by the German research foundation (DFG Grant No. TR534/5-1)
文摘In an extensional shear zone in the Talea Ori, Crete, quartz veins occur in high-pressure low-temperature metamorphic sediments at sites of dilation along shear band boundaries, kink band boundaries and boudin necks. Bent elongate grains grown epitactically from the host rock with abundant fluid inclusion trails parallel to the vein wall indicate vein formation by crack-seal increments during dissolutionprecipitation creep of the host rock. The presence of sutured high-angle grain boundaries and subgrains shows that temperatures were sufficiently high for recovery and strain-induced grain boundary migration, i.e. higher than 300 -350℃, close to peak metamorphic conditions. The generally low amount of strain accumulated by dislocation creep in quartz of the host rock and most veins indicates low bulk stress conditions of a few tens of MPa on a long term. The time scale of stress-loading to cause cyclic cracking and sealing is assumed to be lower than the Maxwell relaxation time of the metasediments undergoing dissolution-precipitation creep at high strain rates(10^(-10) s^(-1) to 10^(-9) s^(-1)), which is on the order of hundred years. In contrast, some veins discordant or concordant to the foliation show heterogeneous quartz microstructures with micro-shear zones, sub-basal deformation lamellae, shortwavelength undulatory extinction and recrystallized grains restricted to high strain zones. These microstructures indicate dislocation glide-controlled crystal-plastic deformation(low-temperature plasticity) at transient high stresses of a few hundred MPa with subsequent recovery and strain-induced grain boundary migration at relaxing stresses and temperatures of at least 300 -350℃. High differential stresses in rocks at greenschist-facies conditions that relieve stress by creep on the long term, requires fast stress-loading rates, presumably by seismic activity in the overlying upper crust. The time scale for stress loading is controlled by the duration of the slip event along a fault, i.e. a few seconds to minutes.This study demonstrates that microstructures can distinguish between deformation at internal low stress-loading rates(to tens of MPa on a time scale of hundred years) and high(coseismic) stress-loading rates to a few hundred MPa on a time scale of minutes.
文摘A photometric analysis and evolutionary stages of the contact binary V2790 Ori are presented.The BV RC observations were carried out at the Thai National Observatory. The photometric light curves were fitted to provide fundamental parameters, required to examine evolutionary stages of the binary. The results indicate that V2790 Ori is a W-type contact system with a mass ratio of q = 2.932. The orbital period increase is found at a rate of d P/dt = 1.03×10^-7 d yr^-1. This implies that a rate of mass transfer from the secondary component to the primary one is dm2/dt =6.31×10^-8 M⊙yr^-1. Furthermore, we find that from the detached phase to the contact phase, the amount of mass that the evolved secondary component has lost is 1.188±0.110 M⊙, i.e., mass lost by the system is 0.789±0.073 M⊙and mass transfer to the primary is0.399±0.037 M⊙. Since the time of the first overflow, the angular momentum loss is found to be 72.2% of JFOF, causing the orbit and Roche surface to shrink until the present time.
文摘一、服务型政府的涵义、基本特征(一)服务型政府的涵义对于"服务型政府"的称谓,学者们的提法不一致,诸如,公共服务取向模式、新公共服务政府、现代的服务型政府、新型的服务型政府等。英国学者E?费利耶认为,在当代西方政府改革运动中,至少有四种不同于传统的公共行政模式的新公共管理模式,公共服务取向模式(Public Service Orientation)
文摘This paper is devoted to binary stars belonging to the class of eclipsing-variable systems.Photometric and spectroscopic analysis of eclipses allows us to determine geometric parameters of the orbit and physical characteristics of stellar components as well as inclinations of stellar equators to the orbital plane. Estimations of inclinations can be obtained from measurement of the Rossiter-McLaughlin effect, which is discussed using examples of some eccentric binaries with an anomalous apsidal effect. Our task is to find the complete spectrum of solutions of the equation of apsidal motion, depending on the inclinations of the polar axes of the components to the orbital one for these systems, based on their individual spectroscopic and photometric observational data. The matrix of solutions allows us to select those pairs of polar inclinations that provide agreement with the observational apsidal period.
基金supported by the National Natural Science Foundation of China (No. 11503077)
文摘Four-color charge-coupled device(CCD) light curves in the B, V, Rc and I c bands of the totaleclipsing binary system V1853 Orionis(V1853 Ori) are presented. By comparing our light curves with those published by previous investigators, it is determined that the O'Connell effect on the light curves has disappeared. By analyzing those multi-color light curves with the Wilson-Devinney code(W-D code),it is discovered that V1853 Ori is an A-type intermediate-contact binary with a degree of contact factor of f = 33.3%(3.7%) and a mass ratio of q = 0.1896(0.0013). Combining our 10 newly determined times of light minima together with others published in the literature, the period changes of the system are investigated. We found that the general trend of the observed minus calculated(O-C) curve shows a downward parabolic variation that corresponds to a long-term decrease in the orbital period with a rate of d P/dt =-1.96(0.46)×10^(-7) d yr^(-1). The long-term period decrease could be explained by mass transfer from the more-massive component to the less-massive one. By combining our photometric solutions with data from Gaia DR_2, absolute parameters were derived as M_1 = 1.20 M⊙, M_2 = 0.23 M⊙, R_1 = 1.36 R⊙and R_2 = 0.66 R⊙. The long-term period decrease and intermediate-contact configuration suggest that V1853 Ori will evolve into a high fill-out overcontact binary.
基金the National Natural Science Foundation of China(No.11873003)the Natural Science Research Key Program of Anhui Provincial Department of Education(No.kj2019A0954)+1 种基金the Outstanding Young Talents Program of Anhui Provincial Department of Education(gxgnfx2019084)the Open Project Program of the Key Laboratory of Optical Astronomy of NAOC。
文摘We present new photometry for two contact binaries,Y Sex and V1363 Ori,which were observed by three small telescopes in China.By using the W-D method,the absolute parameters are updated from new BVR light curves and previous radial velocity curves.Results identify that two binaries are deep,lowmass ratio(DLMR)overcontact binaries with q≤0.25 and f≥50%.From the temperature-luminosity diagram,the primary components are slightly evolved main-sequence stars,whose evolutionary ages are~2.51 Gyr for Y Sex and~3.56 Gyr for V 1363 Ori,respectively.From the(O-C)curves,it is found that the orbital periods may be undergoing secular increase with cyclic variations,which may be interpreted either by magnetic activity cycles or by the light-time orbit effect.With period increasing,this kind of DLMR overcontact binaries,such as Y Sex and V1363 Ori,will evolve into the rapid-rotating single stars.
基金the Scientific Research Projects Coordination Unit of Erciyes University(project number FBA–09–788)。
文摘The first photometric solution in the B,V,R_(c) and I_(c) filters of the short period V1833 Ori eclipsing binary is presented based on new ground-based CCD photometric observations.We analyzed the BVRI photometric light curves of the system,using PHOEBE 0.31 a,a binary star modeling program,with the Wilson-Devinney method based on Roche geometry to achieve the best accordance with the photometric observations to determine their absolute parameters from the light curves.We updated the ephemeris of V1833 Ori using two new light curve minima derived by our new observational data from those collected in the literature and analyzed the change of the system's orbital period.The O-C analysis indicates that the variations of the orbital period of V1833 Ori with time are increasing at a rate of 3.03×10^(-7)days yr^(-1).The distance of V1833 Ori is 173.7±15.6 pc.From the solutions,we find that V1833 Ori is an A-subtype W UMa overcontact binary with q=0.701 mass ratio and f=1.14 fill-out factor.The HR diagram positions of the eclipsing binary system's components are discussed.The system's absolute dimensions were compared to those of similar binaries in the log T_(eff)-log L,logM-logL,1 ogM-logR and logM-log J_(0)diagrams.
