BACKGROUND Leptospira is an uncommon pathogen for adult severe community-acquired pneumonia and its nonspecific manifestations and limited diagnostic tests make it difficult to identify.Although conventional penicilli...BACKGROUND Leptospira is an uncommon pathogen for adult severe community-acquired pneumonia and its nonspecific manifestations and limited diagnostic tests make it difficult to identify.Although conventional penicillin remains efficacious to treat leptospirosis,failure in early diagnosis and treatment can lead to progression into a deadly syndrome with multiple organ dysfunction.Next generation sequencing is of great value to understand cases with infection of unknown cause,which could help in the diagnosis of uncertain Leptospira infection.CASE SUMMARY We recently managed a patient with fever,cough and dyspnea on admission that progressed into persistent adult respiratory distress syndrome,hemoptysis and hematuria after admission.In this case,the rare Leptospira infection was clouded by the positive influenza tests at admission,delaying early Leptospira-targeted antibiotics administration.Next generation sequencing,a novel molecular diagnostic tool,provided a key hint to uncover the crucial pathogen,Leptospira interrogans,further supported by the possible occupational exposure history.Subsequent conventional penicillin and mechanical respiratory support were administrated to cure the patient successfully without any sequela.CONCLUSION Clinicians must pay attention to possible exposure history and keep uncommon Leptospira in mind when managing pneumonia with unknown causes.展开更多
Understanding the fracture behavior of fused silica in contact sliding is important to the fabrication of damage-free optics.This study develops an analytical method to characterize the stress field in fused silica un...Understanding the fracture behavior of fused silica in contact sliding is important to the fabrication of damage-free optics.This study develops an analytical method to characterize the stress field in fused silica under contact sliding by extending the embedded center of dilation(ECD)model and considering the depth of yield region.The effects of densification on the stress fields were considered by scratch volume analysis and finite element analysis.Key mechanisms,such as crack initiation and morphology evolution were comprehensively investigated by analyzing the predicted stress fields and principal stress trajectories.The predictions were validated by Berkovich scratching experiment.It was found that partial conical,median and lateral cracks could emerge in the loading stage of the contact sliding,but radial and lateral cracks could be initiated during unloading.It was also found that the partial conical crack had the lowest initiation load.The intersection of long lateral cracks makes the material removal greater.展开更多
基金Basic Public Welfare Research Scheme of Zhejiang Province,No.GF19H030001.
文摘BACKGROUND Leptospira is an uncommon pathogen for adult severe community-acquired pneumonia and its nonspecific manifestations and limited diagnostic tests make it difficult to identify.Although conventional penicillin remains efficacious to treat leptospirosis,failure in early diagnosis and treatment can lead to progression into a deadly syndrome with multiple organ dysfunction.Next generation sequencing is of great value to understand cases with infection of unknown cause,which could help in the diagnosis of uncertain Leptospira infection.CASE SUMMARY We recently managed a patient with fever,cough and dyspnea on admission that progressed into persistent adult respiratory distress syndrome,hemoptysis and hematuria after admission.In this case,the rare Leptospira infection was clouded by the positive influenza tests at admission,delaying early Leptospira-targeted antibiotics administration.Next generation sequencing,a novel molecular diagnostic tool,provided a key hint to uncover the crucial pathogen,Leptospira interrogans,further supported by the possible occupational exposure history.Subsequent conventional penicillin and mechanical respiratory support were administrated to cure the patient successfully without any sequela.CONCLUSION Clinicians must pay attention to possible exposure history and keep uncommon Leptospira in mind when managing pneumonia with unknown causes.
基金supported by the National Natural Science Foundation of China(Grant Nos.52293401,52205494,52293405)the State Key Laboratory of Mechanical System and Vibration in China(Grant No.MSV202103)+2 种基金the Key Research and Development Projects of Shaanxi Province in China(Grant No.2021GXLH-Z-051)the Shenzhen Key Laboratory of Cross-scale Manufacturing Mechanics Project(Grant No.ZDSYS20200810171201007)the Guangdong Specific Discipline Project(Grant No.2020ZDZX2006).
文摘Understanding the fracture behavior of fused silica in contact sliding is important to the fabrication of damage-free optics.This study develops an analytical method to characterize the stress field in fused silica under contact sliding by extending the embedded center of dilation(ECD)model and considering the depth of yield region.The effects of densification on the stress fields were considered by scratch volume analysis and finite element analysis.Key mechanisms,such as crack initiation and morphology evolution were comprehensively investigated by analyzing the predicted stress fields and principal stress trajectories.The predictions were validated by Berkovich scratching experiment.It was found that partial conical,median and lateral cracks could emerge in the loading stage of the contact sliding,but radial and lateral cracks could be initiated during unloading.It was also found that the partial conical crack had the lowest initiation load.The intersection of long lateral cracks makes the material removal greater.
