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This paper investigated the cyclic plasticity of AA6014-T4P with the tension-compression (T-C) and compression-tension (C-T) cyclic loading tests. A new compression-induced softening behavior is found and modeled. Specifically, the material was softened permanently during the tensile load when a compressive pre-strain was applied, whereas such an abnormal phenomenon was not observed when the loading sequence is reversed. Moreover, the magnitude of the permanent softening scale linearly with the compressive pre strain. Therefore, we term this phenomenon as compression-induced softening in this paper. Based on this compression-induced softening phenomena, a modified Y–U model is formulated by introducing a correction factor that modifies the hardening rate of the boundary surface to describe the permanent softening effect, which can predict the compression-induced softening well. Our work reveals a new phenomenon for the cyclic loading of metal sheets and stimulates further efforts on the path-dependence of metal plasticity. [Display omitted] • Cyclic tension-compression (T-C) and compression-tension (C-T) tests were performed for 6014-T4P aluminum alloys. • An anomalous compression-induced softening behavior of AA6014-T4P was revealed during cyclic loading. • The plastic compressive pre strain is linear with the permanent softening stress drop. • A modified Y–U model was proposed to successfully capture the compression-induced softening behavior. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the underlying pathological muscle damage in neuromyelitis optica spectrum disorder (NMOSD) patients without muscular symptoms. We prospectively enrolled 15 patients with aquaporin 4 (AQP4) antibody seropositive NMOSD and 16 patients with non-NMOSD diseases as a control group. Biceps biopsy samples from 18 patients were examined. Six NMOSD patients exhibited inflammatory lesions/edema in lower muscles on muscle MRI. On histopathological examination, NMOSD samples showed significantly decreased IgG-targeting AQP4 expression on sarcolemma compared with non-NMOSD samples in terms of the area of positive staining and integrated optical density. Muscle biopsy can support the differential diagnosis of NMOSD. Unlabelled Image • NMOSD rarely manifests as symptomatic muscle damage. • Aquaporin 4-IgG seropositive NMOSD exhibits underlying muscular pathological damage • Muscle specimens in NMOSD show decreased AQP4-targeting IgG expression in sarcolemma. • Muscle biopsy can support the differential diagnosis of NMOSD. [ABSTRACT FROM AUTHOR]

Coptidis rhizoma (CR) is the dried rhizome of the ranunculaceous plant CR. For decades in China, this plant has been used to treat hypertension, hyperlipidemia, and chronic diarrhea and has been officially included in the Chinese Pharmacopoeia. The present paper presents a review of the pharmacokinetics of CR. The pharmacokinetic studies and differences of 10 alkaloids among Coptis deltoidea C. Y. cheng et Hsiao, Coptis chinensis Franch and Coptis teeta Wall. Are seldom reported. This study is the first to determine corydaline, dehydrocorydaline, tetrahydropalmatine, palmatine, magnoflorine, jatrorrhizine, berberine, worenine, berberrubine, and coptisine, which adopted an ultrahigh-performance liquid chromatography-electrospray ionization-tandem mass spectrometry, simultaneously. Chromatographic separation was performed within 8 min by using an Agilent SB-C 18 column (150 mm × 2.1 mm, 1.8 μm) with gradient mobile phase consisting of 0.3% acetic acid water (v / v) and acetonitrile at a flow rate of 0.3 mL/min. Multiple reaction monitoring mode was used to detect the tandem mass spectrum in the positive ionization mode by electrospray ionization source. The method was fully validated to be linear over a wide concentration (r > 0.9916), and the linear concentration range was 0.195–2260 ng/mL. Intra- and interday precisions were below 14.19% and 18.56% for the 10 analytes, respectively. The accuracy ranged from −9.30% to 6.31%. The extraction recovery of the 10 alkaloids and internal standard ranged from 79.76% to 95.37%. Pharmacokinetic comparative study showed that the C max and AUC 0-∞ values of dehydrocorydaline, tetrahydropalmatine, palmatine, magnoflorine, jatrorrhizine, berberine, worenine, berberrubine, and coptisine increased significantly (p < 0.05), which was different for beagles after oral administration. The results can help determine the mechanism of action and guide clinical application of these three extracts. This validated method was successfully applied for the pharmacokinetics study of beagle plasma after oral administration of three CR extract types. Image 1 [ABSTRACT FROM AUTHOR]