BACKGROUND Osteoarticular tuberculosis(OATB) is a severe form of extrapulmonary TB, which causes notable morbidity and warrants a high index of suspicion for prompt management. The diagnosis of OATB poses a challenge,...BACKGROUND Osteoarticular tuberculosis(OATB) is a severe form of extrapulmonary TB, which causes notable morbidity and warrants a high index of suspicion for prompt management. The diagnosis of OATB poses a challenge, because of the difficulty of collecting the samples and, secondarily, the paucibacillary nature of lesion, which gives poor sensitivity and reproducibility, with long turnaround time of routine/conventional laboratory tests and the requirement for invasive procedures and expertise. The Xpert MTB/RIF assay has been approved by the World Health Organization as a rapid diagnostic tool for diagnosing pulmonary and extrapulmonary TB.AIM To emphasize the diagnostic efficiency of gene Xpert for OATB in suspected patients in a tertiary care hospital of Eastern India.METHODS This retrospective study was conducted in the Department of Microbiology and Orthopaedics by analyzing the data of the gene Xpert assay over a 3-year duration from January 2018 to February 2021. Demographic and clinical data were recorded. The diagnostic efficiency of gene Xpert was evaluated against the composite reference standard(CRS).RESULTS A total of 37 cases fell into positive, probable, and possible categories of osteoarticular TB out of 112 patients included in the study by CRS;gene Xpert result was positive in 35 out of the 37 different CRS categorized cases. Of the 112 cases, culture was put in 40 cases, and, of these cultures, 5 cases showed the growth of MTB. Of these, 4 cases were included in the 35 cases diagnosed by gene Xpert.Smear microscopy was positive in 6 out of 37 CRS categorized cases. When compared with CRS, the sensitivity of gene Xpert assay, culture, and smear was found to be 94.6%, 13.5%, and 16.2%, respectively, while specificity in all the three types of tests was 100%. When kappa statistics were applied, the percentage of agreement gene Xpert, culture, and microscopy with CRS was found to be 95%, 20%, and 22.6%, respectively. Follow-up of the gene Xpert positive patients after getting anti-tubercular treatment revealed improved conditions.CONCLUSION Gene Xpert could detect 31 extra cases with a low and very low mycobacterial load that were missed by the routine culture methods. Hence, more samples should be processed for molecular diagnostic methods like gene Xpert along with other conventional methods for the validation of the molecular test prospectively for the timely diagnosis of osteoarticular TB.展开更多
Superalloys feature multi-elements and complex elemental ranges,which makes the proper composition selection difficult.In fact,more strict composition standards generally apply in practical productions.The objective o...Superalloys feature multi-elements and complex elemental ranges,which makes the proper composition selection difficult.In fact,more strict composition standards generally apply in practical productions.The objective of this paper is to understand and eventually to renew the composition standard via example of the most common grade Inconel 718.We have recently shown that t he alloy chemistry originates from a nearest-neighbor cluster[center-shell]plus a few next-neighbor glue atoms,or expressed in cluster for-mula[center-shell](glue atoms).By grouping the elements into Ni=(Ni,Co,Cu,Fe),Cr=(Cr,Mn,Si,Mo),and Nb=(Nb,Al,Ti),it is found that the reported alloys fall within a narrow composition zone Ni_(11.0-13.0)-Cr_(3.5-4.5)-Nb_(1) confined by cluster formulas of 16 and 18 atoms.This composition zone is also expressed in terms of 288-atom supercluster formulas,Ni_(198-208)-Cr_(63-72)-Nb_(16-18),which leads to coordi-nated elemental variations in wt.%:69.0≤Ni+Co+Cu+Fe≤72.7;19.8≤Cr+Mn+1.7 Si+0.6 Mo≤22.8;8.7≤Nb+3.2 Al+1.9 Ti≤9.8.Within this composition zone,Ni_(206)-Cr_(65.5)-Nb_(16.5) is further pinpointed and validated by our own experiments to possess the optimal match of strength and plasticity both at room and at 923 K.展开更多
文摘BACKGROUND Osteoarticular tuberculosis(OATB) is a severe form of extrapulmonary TB, which causes notable morbidity and warrants a high index of suspicion for prompt management. The diagnosis of OATB poses a challenge, because of the difficulty of collecting the samples and, secondarily, the paucibacillary nature of lesion, which gives poor sensitivity and reproducibility, with long turnaround time of routine/conventional laboratory tests and the requirement for invasive procedures and expertise. The Xpert MTB/RIF assay has been approved by the World Health Organization as a rapid diagnostic tool for diagnosing pulmonary and extrapulmonary TB.AIM To emphasize the diagnostic efficiency of gene Xpert for OATB in suspected patients in a tertiary care hospital of Eastern India.METHODS This retrospective study was conducted in the Department of Microbiology and Orthopaedics by analyzing the data of the gene Xpert assay over a 3-year duration from January 2018 to February 2021. Demographic and clinical data were recorded. The diagnostic efficiency of gene Xpert was evaluated against the composite reference standard(CRS).RESULTS A total of 37 cases fell into positive, probable, and possible categories of osteoarticular TB out of 112 patients included in the study by CRS;gene Xpert result was positive in 35 out of the 37 different CRS categorized cases. Of the 112 cases, culture was put in 40 cases, and, of these cultures, 5 cases showed the growth of MTB. Of these, 4 cases were included in the 35 cases diagnosed by gene Xpert.Smear microscopy was positive in 6 out of 37 CRS categorized cases. When compared with CRS, the sensitivity of gene Xpert assay, culture, and smear was found to be 94.6%, 13.5%, and 16.2%, respectively, while specificity in all the three types of tests was 100%. When kappa statistics were applied, the percentage of agreement gene Xpert, culture, and microscopy with CRS was found to be 95%, 20%, and 22.6%, respectively. Follow-up of the gene Xpert positive patients after getting anti-tubercular treatment revealed improved conditions.CONCLUSION Gene Xpert could detect 31 extra cases with a low and very low mycobacterial load that were missed by the routine culture methods. Hence, more samples should be processed for molecular diagnostic methods like gene Xpert along with other conventional methods for the validation of the molecular test prospectively for the timely diagnosis of osteoarticular TB.
基金supported by the Key Discipline and Major Project of Dalian Science and Technology Innovation Foun-dation(No.2020JJ25CY004).
文摘Superalloys feature multi-elements and complex elemental ranges,which makes the proper composition selection difficult.In fact,more strict composition standards generally apply in practical productions.The objective of this paper is to understand and eventually to renew the composition standard via example of the most common grade Inconel 718.We have recently shown that t he alloy chemistry originates from a nearest-neighbor cluster[center-shell]plus a few next-neighbor glue atoms,or expressed in cluster for-mula[center-shell](glue atoms).By grouping the elements into Ni=(Ni,Co,Cu,Fe),Cr=(Cr,Mn,Si,Mo),and Nb=(Nb,Al,Ti),it is found that the reported alloys fall within a narrow composition zone Ni_(11.0-13.0)-Cr_(3.5-4.5)-Nb_(1) confined by cluster formulas of 16 and 18 atoms.This composition zone is also expressed in terms of 288-atom supercluster formulas,Ni_(198-208)-Cr_(63-72)-Nb_(16-18),which leads to coordi-nated elemental variations in wt.%:69.0≤Ni+Co+Cu+Fe≤72.7;19.8≤Cr+Mn+1.7 Si+0.6 Mo≤22.8;8.7≤Nb+3.2 Al+1.9 Ti≤9.8.Within this composition zone,Ni_(206)-Cr_(65.5)-Nb_(16.5) is further pinpointed and validated by our own experiments to possess the optimal match of strength and plasticity both at room and at 923 K.
