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
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
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
We obtained new high-resolution spectra using the Lijiang 1.8-m and 2.4-m telescopes to inves- tigate the chromospheric activities of V1355 Ori as indicated in the behaviors of Ca n H＆K, Hγ HT, H/3, Na1 D1, D2, Ha a...We obtained new high-resolution spectra using the Lijiang 1.8-m and 2.4-m telescopes to inves- tigate the chromospheric activities of V1355 Ori as indicated in the behaviors of Ca n H＆K, Hγ HT, H/3, Na1 D1, D2, Ha and Ca II infrared triplet （IRT） lines. The observed spectra show obvious emissions above the continuum in Ca II H＆K lines, absorptions in the Hδ, Hγ, H/3 and NaI D1, D2 lines, variable behavior （filled-in absorption, partial emission with a core absorption component or emission above the continuum） in the Ha line, and weak self-reversal emissions in the strong filled-in absorptions of the Ca II IRT lines. We used a spectral subtraction technique to analyze our data. The results show no excess emission in the H6 and H7 lines, very weak excess emissions in the Na I D1, D2 lines, excess emission in the H/3 line, clear excess emission in the Ha line, and excess emissions in the Ca II IRT lines. The value of the ratio of EWs542/EWsa9s is in the range 0.9 to 1.7, which implies that chromospheric activity might have been caused by plage events. The value of the ratio EHδ/EHβ is above 3, indicating that the Balmer lines would arise from prominence-like material. We also found time variations in light curves associated with equiva- lent widths of chromospheric activity lines in the Na I D1, phenomena can be explained by plage events, which are activity indicators. D2, Ca II IRT and Ha lines in particular. These consistent with the behavior of chromospheric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.
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.
基金supported by the Astronomic Joint Fund of the National Natural Science Foundation of China and Chinese Academy of Sciences (U1431114,U1631236,U1631109 and 11263001)science and technology innovation team of Guizhou province(No.20154017)supported by the Natural Science Foundation of Guizhou Province Office of Education(Grant No.2014298)
文摘We obtained new high-resolution spectra using the Lijiang 1.8-m and 2.4-m telescopes to inves- tigate the chromospheric activities of V1355 Ori as indicated in the behaviors of Ca n H＆K, Hγ HT, H/3, Na1 D1, D2, Ha and Ca II infrared triplet （IRT） lines. The observed spectra show obvious emissions above the continuum in Ca II H＆K lines, absorptions in the Hδ, Hγ, H/3 and NaI D1, D2 lines, variable behavior （filled-in absorption, partial emission with a core absorption component or emission above the continuum） in the Ha line, and weak self-reversal emissions in the strong filled-in absorptions of the Ca II IRT lines. We used a spectral subtraction technique to analyze our data. The results show no excess emission in the H6 and H7 lines, very weak excess emissions in the Na I D1, D2 lines, excess emission in the H/3 line, clear excess emission in the Ha line, and excess emissions in the Ca II IRT lines. The value of the ratio of EWs542/EWsa9s is in the range 0.9 to 1.7, which implies that chromospheric activity might have been caused by plage events. The value of the ratio EHδ/EHβ is above 3, indicating that the Balmer lines would arise from prominence-like material. We also found time variations in light curves associated with equiva- lent widths of chromospheric activity lines in the Na I D1, phenomena can be explained by plage events, which are activity indicators. D2, Ca II IRT and Ha lines in particular. These consistent with the behavior of chromospheric
