Fabrication of a strong and ductile CuCrZr alloy using laser powder bed fusion

The production of Cu-alloy-based components using laser powder bed fusion (L-PBF) is hindered by the low laser absorptivity and high thermal conductivity of these alloys. In this study, we developed a trace alloying method to fabricate strong and ductile CuCrZr alloys using l-PBF. The laser absorptivity and flowability of the CuCrZr powders were enhanced by the trace Zr alloying because of the existence of surface oxide scales, resulting in the production of dense l-PBF builds. The surface oxides or in-situ oxidation generated irregular Zr/Cr oxide nanoparticles, which were distributed throughout the build structure. The subsequent hot isostatic pressing, solution treatment, and aging multisteps resulted in the homogeneous precipitation of submicron Cr particles, which formed coherent interfaces with the Cu matrix. Consequently, a CuCrZr alloy with a high strength and ductility of 287 MPa and 42%, respectively, was successfully prepared owing to the enhanced l-PBF processability and effective precipitation strengthening. The findings of this study suggest that high-performance Cu alloys can be designed and manufactured for various applications by combining the l-PBF and traditional metallurgical processes

Prevalence of Asymptomatic Mpox among Men Who Have Sex with Men, Japan, January–March 2023

We prospectively assessed asymptomatic monkeypox virus infections among men who have sex with men in Tokyo, Japan, during the initial phase of the mpox epidemic. Our findings suggest that asymptomatic infections were likely underestimated and were comparable in magnitude to symptomatic infections, highlighting the need to improve testing accessibility among high-risk populations

Conjunctivitis, the key clinical characteristic of adult rubella in Japan during two large outbreaks, 2012-2013 and 2018-2019.

BackgroundRubella virus infection mainly causes illness with mild fever, rash, and lymphadenopathy in children; however, the clinical characteristics of adult rubella are not well-known.MethodsAn observational study was conducted to compare the characteristics between adult rubella and adult non-rubella among participants aged ≥18 years, with suspected symptomatic rubella. Participants were screened for rubella-specific IgM expression using an enzyme immune assay kit, at a tertiary care hospital in Japan during two outbreaks (January 2012-December 2013 and January 2018-March 2019). Adult rubella diagnosis followed strong positive or paired rubella-specific IgM expression or positive rubella-specific reverse-transcription-polymerase chain reaction. Patients aged ResultsOverall, 82 adult rubella and 139 adult non-rubella, with a median age (interquartile range) of 31 (25-41) years and 34 (27-42) years, respectively, were included. Multivariate analysis showed that conjunctivitis (odds ratio 80.6; 95% confidence interval 13.4-486.3; P ConclusionsConjunctivitis was the key clinical symptom associated with adult rubella. For the early diagnosis of adult rubella, clinicians should focus on assessing conjunctivitis in patients

A matched case-case-control study of the impact of clinical outcomes and risk factors of patients with IMP-type carbapenemase-producing carbapenem-resistant enterobacteriaceae in Japan

IMP-type carbapenemase, found in various Gram-negative bacteria, has been increasingly detected worldwide. We aimed to study the outcomes and risk factors for acquisition of IMP-type carbapenemase-producing carbapenem-resistant Enterobacteriaceae (IMP-CRE), as this has not been evaluated in detail. We conducted a matched case-case-control study of patients from whom IMP-CRE isolates were obtained. All patients who tested positive for IMP-CRE were included; they were matched with patients with carbapenem-susceptible Enterobacteriaceae (CSE) and with controls at a ratio of 1:1:2. The risk factors for acquisition for the CRE and CSE groups and mortality rates, which were calculated using multivariate logistic regression models with weighting according to the inverse probability of propensity scores, were compared. In total, 192 patients (96 patients each in the CRE and CSE groups, with 130 Enterobacter cloacae isolates and 62 Klebsiella sp. isolates) were included. The IMP-11 type was present in 43 patients, IMP-1 in 33, and IMP-60 and IMP-66 in 1 each; 31 patients with CRE (32.3%) and 34 with CSE (35.4%) developed infections. Multivariate analysis identified the following independent risk factors: gastrostomy, history of intravenous therapy or hemodialysis, and previous exposure to broad-spectrum β-lactam antibiotics, including penicillin with β-lactamase inhibitors, cephalosporins, and carbapenems. In propensity score-adjusted analysis, mortality rates for the CRE and CSE groups were similar (15.0% and 19.5%, respectively). We found that IMP-CRE may not contribute to worsened clinical outcomes, compared to CSE, and gastrostomy, previous intravenous therapy, hemodialysis, and broad-spectrum antimicrobial exposure were identified as risk factors for CRE isolation. Fluoroquinolone and aminoglycosides are potentially useful antibiotics for IMP-CRE infections

Travel-associated chikungunya acquired in Myanmar in 2019

International audienc