In this study, the strains of artificial rock were analyzed in order to estimate the deformation behavior of rock-like materials in the SHPB test. The axial strain measured directly from the strain ...gage and obtained from the process analysis of three-wave method were compared. The analysis results show that: (1) the measurements of dynamic strains of material obtained from the strain gage method are feasible; (2) the axial strains and strain rates analyzed from the strain gage records are less than those obtained from the three-wave method; (3) the dynamic/static deformation modulus ratio Ed/Es has the increasing tendency with the raising of stress rate, and the modulus ratio obtained from the strain gage method is more than that obtained from the three-wave method.
Proximal spinal muscular atrophy (SMA) is a motor neuron degeneration disorder for which there is currently no effective treatment. Here, we report three compounds (sodium vanadate, trichostatin A ...and aclarubicin) that effectively enhance SMN2 expression by inducing Stat5 activation in SMA-like mouse embryonic fibroblasts and human SMN2-transfected NSC34 cells. We found that Stat5 activation enhanced SMN2 promoter activity with increase in both full-length and deletion exon 7 SMN transcripts in SMN2-NSC34 cells. Knockdown of Stat5 expression disrupted the effects of sodium vanadate on SMN2 activation but did not influence SMN2 splicing, suggesting that Stat5 signaling is involved in SMN2 transcriptional regulation. In addition, constitutive activation of Stat5 mutant (Stat5A1*6) profoundly increased the number of nuclear gems in SMA-patient lymphocytes and reduced SMA-like motor neuron axon outgrowth defects. These results demonstrate that Stat5 signaling could be a possible pharmacological target for treating SMA.
Background: Orthokeratology (Ortho-k) is an effective method for slowing the progression of myopia and correcting refractive error in school children. Although parents of children aged ＜ 10 years ...play a major role in Ortho-k lens care, they have a generally low level of compliance in performing regular follow-up visits. Purpose: This study was developed to analyze the associations between follow-up visits by parents ofOrtho-k lenswearers aged ＜ 10 years and, respectively, the Ortho-k-related knowledge of these parents and information resources promoting Ortho-k use. Methods: A cross-sectional study design was used. Parents of children whowearOrtho-k lenses were recruited through a private Facebook group with 3,500 members in 2020 that was created in 2018 for information sharing and exchange among parents of these children. The following data were collected: demographics of the parents and their children, four-item Ortho-k-related knowledge, information resources that prompted the decision to use Ortho-k, and
Prion diseases are induced by pathologically misfolded prion protein (PrPSc), which recruit normal sialoglycoprotein PrPC by a template-directed process. In this study, we investigated the expression ...of PrPC in a rat model of cerebral ischemia to more fully understand its physiological role. Immunohistochemical analysis demonstrated that PrPC-immunoreactive cells increased significantly in the penumbra of ischemic rat brain compared with the untreated brain. Western blot analysis showed that PrPC protein expression increased in ischemic brain tissue in a time-dependent manner. In addition, PrPC protein expression was seen to colocalize with neuron, glial, and vascular endothelial cells in the penumbric region of the ischemic brain. Overexpression of PrPC by injection of rAd (replication-defective recombinant adenoviral)-PGK (phosphoglycerate kinase)-PrPC-Flag into ischemic rat brain improved neurological behavior and reduced the volume of cerebral infarction, which is supportive of a role for PrPC in the neuroprotective adaptive cellular response to ischemic lesions. Concomitant upregulation of PrPC and activated extracellular signal-regulated kinase (ERK1/2) under hypoxia-reoxygenation in primary cortical cultures was shown to be dependent on ERK1/2 phosphorylation. During hypoxia-reoxygenation, mouse neuroblastoma cell line N18 cells transfected with luciferase rat PrPC promoter reporter constructs, containing the heat shock element (HSE), expressed higher luciferase activities (3- to 10-fold) than those cells transfected with constructs not containing HSE. We propose that HSTF-1 (hypoxia-activated transcription factor), phosphorylated by ERK1/2, may in turn interact with HSE in the promoter of PrPC resulting in gene expression of the prion gene. In summary, we conclude that upregulation of PrPC expression after cerebral ischemia and hypoxia exerts a neuroprotective effect on injured neural tissue. This study suggests that PrPC has physiological relevance to cerebral ischemic injury and could be useful as a therapeutic target for the treatment of cerebral ischemia.
Atherosclerosis develops in different locations of the vasculature with different degree, which may result from different antioxidant/prooxidant status. This study investigated the effect of ...high-fat, high-cholesterol chows, with or without vitamin E supplement (450 mg/kg diet), on lipid peroxide levels, glutathione peroxidase expression, and atheroma formation in ascending aorta, pulmonary arteries and thoracic aorta.
Sixty-four rabbits were divided to be fed with 4 different chows for 6 weeks. The percentage of atherosclerosis was measured. Plasma and vascular glutathione peroxidase activity and mRNA expression, and lipid peroxide levels were also assayed.
Rabbits on high-fat, high-cholesterol chows had higher lipid peroxide levels and more atherosclerosis in ascending aorta and pulmonary arteries. Tissues in thoracic aorta had higher glutathione peroxidase activity and mRNA expression without any significant increase in lipid peroxide levels and atherosclerosis. Vitamin E supplement decreased plasma lipid peroxide levels, but not in tissues, and thus could not prevent atherosclerosis.
Higher glutathione peroxidase expression in the thoracic aorta inhibits oxidative stress enhancement and atheroma progression induced by high-fat, high-cholesterol chows. Vitamin E supplement at the current dosage and duration could not prevent atheroma formation.
Background
. High-fat diet (HFD) induces systemic insulin resistance leading to myocardial dysfunction. We aim to characterize the early adaptations of myocardial glucose utility to HFD-induced ...insulin resistance.
Methods
. Male Sprague–Dawley rats were assigned into two groups, fed a regular chow diet or HFD ad libitum for 10 weeks. We used
in vivo
imaging of cardiac magnetic resonance (CMR),
18
F-FDG PET, and ex vivo nuclear magnetic resonance (NMR) metabolomic analysis for the carbon-13-labeled glucose (U-
13
CGlc) perfused myocardium.
Results
. As compared with controls, HFD rats had a higher ejection fraction and a smaller left ventricular end-systolic volume (
P
<
0.05
), with SUV
max
of myocardium on
18
F-FDG PET significantly increased in 4 weeks (
P
<
0.005
). The U-
13
CGlc probed the increased glucose uptake being metabolized into pyruvate and acetyl-CoA, undergoing oxidative phosphorylation via the tricarboxylic acid (TCA) cycle, and then synthesized into glutamic acid and glutamine, associated with overexpressed LC3B (
P
<
0.05
).
Conclusions
. HFD-induced IR associated with increased glucose utility undergoing oxidative phosphorylation via the TCA cycle in the myocardium is supported by overexpression of glucose transporter, acetyl-CoA synthase. Noninvasive imaging biomarker has potentials in detecting the metabolic perturbations prior to the decline of the left ventricular function.
Magneto-transport measurements are performed on the AlGaAs/GaAs quantum Hall (QH) devices fabricated recently by our group. A series of Hall plateaus are observed with increasing the perpendicular ...magnetic field, and the mobility gaps resulting from localization effects are investigated at the minima in the longitudinal resistivity. Only the gap corresponding to the filling factor i = 2 is close to the expected cyclotron energy, and our study supports that the low-field QH conductors may suffer problems due to insufficient localization. The anomalous change on the Hall slope is observed when the i = 3 plateau is destroyed by the large current.
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