Search

Highlights • A ballistic pendulum was developed to implement water-backed plates to shock loading in water. • Deformation resistant capability and anti-shockwave performance of water-backed sandwich panel were investigated by 28 experiments and compared with monolithic plates. • Quantitative results, including the evolution of the deflection along radius of face-sheet and volumetric strain of honeycomb core, characterized permanent deformation of sandwich panel. • The secondary pressure wave was recorded by a sensor and analysed systematically. • A failure map was performed to identify the effect of panel configurations on structure failure mechanism at this blast magnitude. Abstract Explosion tests were performed underwater to study the blast resistance of water-backed sandwich panels. Effects on the structural response of face-sheet and core configurations, including face-sheet thickness, cell wall thickness of the honeycomb, core thickness and charge mass, were investigated by a large number of experiments. Quantitative results were obtained in the tests with corresponding sensors and further processing. Further results characterized the permanent deformation of sandwich panels. A failure mode map was adopted to identify the effect of design parameters on the structural failure mechanism at this blast magnitude. Finally, a comparison between sandwich panels and monolithic plates was performed. The comparative study provided further experimental evidence for the benefits of sandwich in water-backed configuration. Present study led to the apprehension of blast resistance of water-backed sandwich structure to underwater blast load, thereby developed useful guidelines for the design of blast-resistant structural systems. [ABSTRACT FROM AUTHOR]

Abstract Damage severity of sandwich panels to underwater explosion load depend not only on the shock factors, but also on the fluid behind the structure. Underwater explosion tests were performed on water-backed sandwich panels to examine the deformation and failure of such composite structure. The dynamic blast response of water-backed sandwich panel was investigated using the LS-DYNA software. An analytical three-stage model was developed for the deformation history of water-backed sandwich panel subjected to shock loading in water. Blast resistance of water-backed sandwich panel was compared with monolithic plate of equivalent areal mass and air-backed sandwich panel with the same configurations. Water-backed sandwich panel exhibited the best deformation/damage resistant capability. Compared with air-backed sandwich panel, core material exhibited greater volumetric strain when the sandwich structure wetted on both sides. Overpressure in the water behind structure was reduced to about 7% by using sandwich structure over monolithic plate of equivalent thickness. Present study led to the apprehension of dynamic response of water-backed sandwich structure to underwater blast load, thereby developed useful guidelines for the design of blast-resistant structural systems. [ABSTRACT FROM AUTHOR]

Obesity and related diseases are becoming a growing risk for public health around the world due to the westernized lifestyle. Sema7A, an axonal guidance molecule, has been known to play a role in neurite growth, bone formation, and immune regulation. Whether Sema7A participates in obesity and metabolic diseases is unknown. As several SNPs in SEMA7A and its receptors were found to correlate with BMI and metabolic parameters in the human population, we investigated the potential role of Sema7A in obesity and hepatic steatosis. GWAS and GEPIA database was used to analyze SNPs in SEMA7A and the correlation of Sema7A expression with lipid metabolism related genes. Sema7A−/− mice and recombinant Sema7A (rSema7A) were used to study the role of Sema7A in HFD-induced obesity and hepatic steatosis. Adipose tissue-derived mesenchymal stem cells (ADSCs) were used to examine the role of Sema7A in adipogenesis, lipogenesis and downstream signaling. Deletion of Sema7A aggravated HFD-induced obesity. Sema7A deletion enhanced adipogenesis in both subcutaneous and visceral ADSCs, while the addition of rSema7A inhibited adipogenesis of ADSCs and lipogenesis of differentiated mature adipocytes. Sema7A inhibits adipo/lipogenesis potentially through its receptor integrin β1 and downstream FAK signaling. Importantly, administration of rSema7A had protective effects against diet-induced obesity in mice. In addition, deletion of Sema7A led to increased hepatic steatosis and insulin resistance in mice. Our findings reveal a novel inhibitory role of Sema7A in obesity and hepatic steatosis, providing a potential new therapeutic target for obesity and metabolic diseases. • Sema7A−/− mice are more sensitive to diet-induced obesity, hepatic steatosis and insulin resistance. • Sema7A inhibits adipo/lipogenesis and potentially protects against diet-induced obesity via the integrin β1/FAK axis. • Administration of recombinant Sema7A protects against diet-induced obesity in mice. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to develop a predictive model of early neurological deterioration (END) in patients with acute ischemic stroke (AIS).Methods: The present retrospective cohort study considered patients with AIS who were admitted to a tertiary hospital in Shenzhen, China between January 2014 and December 2018. An increase of 2 points or more on the National Institute of Health Stroke Scale (NIHSS) within 7 days indicated END. We selected baseline clinical, laboratory, and neuroimaging variables to construct predictive models through multivariate logistic regression. The receiver operating characteristic curve and calibration plots were calculated.Results: A total of 391 patients with AIS were enrolled in the study. END was observed in 64 (16.4%) cases. A prediction model developed from the initial NIHSS score, middle cerebral artery stenosis, and carotid stenosis of≥ 50% showed good discriminative ability: area under the receiver operating characteristic curve, 0.870 (95%CI, 0.813-0.911); threshold, -1.570; specificity, 84.40%; sensitivity, 75.00%; positive predictive value, 48.48%; and a negative predictive value, 94.52%.Conclusion: Our predictive model developed from the initial NIHSS score, middle cerebral artery stenosis, and carotid stenosis of ≥ 50% could identify patients with AIS who were at risk of developing END. The model requires validation by larger studies performed at other institutions. [ABSTRACT FROM AUTHOR]

Large vessel occlusion stroke, caused by cardiac myxoma, is a rare and severe condition with poor neurological outcomes. Currently, there are no clear guidelines for treating patients with this condition. In our case, we describe a rare case of acute ischemic stroke caused by cardiac myxoma which was successfully treated with mechanical thrombectomy. At the end of a 6 months' follow-up, her National Institutes of Health Stroke Scale score (NIHSS) had significantly improved, from 20 to 3. This result is encouraging and suggests that mechanical thrombectomy may be a feasible therapy for large vessel occlusion stroke induced by cardiac myxoma emboli. [ABSTRACT FROM AUTHOR]

To investigate characteristics of intra- and extracranial arterial culprit plaques between patients with single infarct and multiple-infarcts by a head-neck combined high resolution magnetic resonance vessel wall imaging (HR-MRVWI). Forty-three patients with recent ischemic stroke due to large artery atherosclerosis were enrolled. The head-neck combined HR-MRVWI was performed in all patients both pre- and post-contrast administration. Based on diffusion weighted imaging findings, patients were divided into single-infarction and multiple-infarction groups. For patients with anterior circulation ischemic stroke, they were also divided into perforating artery infarction (PAI) and non-PAI groups. Patient demographics, number and location of culprit plaques, artery stenosis percentage, intraplaque hemorrhage, and plaque enhancement were evaluated and compared between single-infarction and multiple-infarction groups, as well as between PAI and non-PAI groups. A total of 83 culprit plaques were identified. The artery stenosis degree was more severe and plaque enhancement more prominent in multiple-infarction group than in single-infarction group. Patients with multiple infarcts also had more culprit plaques per patient than those with single infarct, which contributed to the occurrence of multiple infarcts. For comparison of PAI and non-PAI groups, a higher artery stenosis percentage was observed in non-PAI group, and patients with non-PAI had more culprit plaques per patient, which contributed to a variety of infarct manifestations. A higher stenosis grade and higher number of culprit plaques seem to be associated with a higher number of cerebral infarcts in patients with large artery atherosclerosis. [ABSTRACT FROM AUTHOR]

Emerging evidence shows that perivascular adipose tissue (PVAT) is crucially involved in inflammation and cardiovascular diseases. However, controversial results have been reported regarding the effect of PVAT in atherosclerosis. This study aimed to determine the role of PVAT in disturbed blood flow (d-flow)-induced carotid plaque formation. ApoE −/− male mice underwent partial carotid ligation (PCL) to induce d-flow in the left carotid artery (LCA) and were fed a high-fat diet for 2 weeks. Oil Red O and hematoxylin and eosin stains were used to determine adipose tissue. Thoracic PVAT from ApoE −/− or wild-type female mice were transplanted to the LCA of PCL-treated ApoE −/− mice. Carotid arteries were stained with Sudan IV to detect atherosclerotic lesions. Quantitative real-time reverse transcription polymerase chain reaction and immunofluorescence staining were performed to assess macrophage infiltration. By 2 weeks of the high-fat diet after PCL surgery, de novo adipose tissue was formed around the ligated LCA, where atherosclerotic plaques were also observed. Quantitative real-time reverse transcription polymerase chain reaction analysis of the newly formed PVAT revealed a similar transcription profile to native PVAT. Treatment with bisphenol A diglycidyl ether, a peroxisome proliferator-activated receptor γ inhibitor, diminished PVAT formation but increased plaque size and macrophage infiltration. Transplantation of thoracic PVAT from wild-type mice (PVAT-T WT ) rather than from ApoE −/− mice (PVAT-T ApoE−/− ) nearly abrogated LCA plaque macrophage content without affecting plaque size. Mechanistically, PVAT-T ApoE−/− showed higher messenger RNA levels of inflammatory cytokines compared with PVAT-T WT . Our findings suggest that regulated PVAT formation may confer protection against atherosclerosis-prone shear stress, probably through attenuation of focal inflammation. Clinical studies demonstrated that perivascular adipose tissue (PVAT) is anatomically close to atherosclerotic plaques and associated with plaque burden and vascular calcification. Here we showed a beneficial role of PVAT in atherosclerosis protection, suggesting the potential value of PVAT transplantation in disease control and prevention. [ABSTRACT FROM AUTHOR]

Rheumatoid arthritis (RA) is a multifaceted autoimmune disease characterized by systemic inflammation, affecting both articular and extra-articular structures. This condition results in inflammation of joints and synovial membranes, accompanied by the development of systemic comorbidities. Despite extensive research, the precise pathogenic mechanisms responsible for RA have yet to be completely understood. RNA methylation, a burgeoning epigenetic alteration, assumes a pivotal function in the regulation of a myriad of biological phenomena, encompassing immunity, DNA damage response, tumorigenesis, metastasis, stem cell renewal, adipocyte differentiation, circadian rhythms, cellular development and differentiation, and cell division. The N6-methyladenosine (m6A) modification is the most prevalent among the various RNA modifications found in mammalian mRNA. Recent studies have provided evidence of the significant role played by m6A modification in the pathophysiological progression of RA. This review aims to provide a comprehensive analysis of the progress made in research focused on m6A modification in the context of RA, consolidate the underlying mechanisms involved in m6A modification during the initiation of RA and discuss the potential of targeting m6A modification as a viable therapeutic approach for RA. • m6A levels and expression of methylation-related enzymes alters in RA. • m6A levels and methylation-related enzymes are related to disease activities in RA. • methylation-related enzymes play crucial roles in PBMCs, macrophage, and FLSs in RA. [ABSTRACT FROM AUTHOR]

With the implementation of energy saving and carbon reduction, the quantitative analysis of solar energy spectral characteristics has been paid more and more attention. Currently, the international test standards provide a spectral distribution with a large span between different wavebands, which makes it difficult to meet the needs of special spectral wavebands. In this paper, based on the principle of spectral splitting, the spectral distribution of solar radiation models (SDSR models) is proposed, and the differences in the spectral distributions of natural outdoor and artificial indoor light sources are evaluated. Firstly, the differences in PV module output power between the outdoor light sources and indoor artificial light sources are assessed in terms of inclination angle and solar radiation, respectively. Secondly, based on that difference, the influencing factors of the spectral distribution of solar radiation are investigated, and the SDSR models of different wavelengths is established based on spectral analysis results. Finally, based on the established SDSR models, the spectral distribution modified models (SDM models) for different inclination angles under artificial light sources is proposed. By comparing the calculated values of the SDM models with the measured data, the calculated values of the model are close to the measured data at different incidence angles. The SDM models proposed in this paper shortens the gap between the spectral distribution of the artificial light source and the outdoor natural light source, and reveal the influence mechanism of the difference in the output power of indoor and outdoor PV modules from the perspective of the spectral distribution. The results can provide guidance for the spectral distribution of solar radiation and the quantitative modification of the artificial light source. • The difference in the output power of PV modules between solar radiation and artificial light sources is evaluated. • The effect of inclination angle and orientation on the spectral distribution of solar radiation is investigated. • The spectral distribution of solar radiation model (SDSR model) at different wavelengths is developed. • The spectral modification models for different wavelengths of of artificial light sources are developed. [ABSTRACT FROM AUTHOR]

Abstract: Transcription factor Pbx4 is recruited to form dimeric or trimeric complexes with Hox and/or Meis homeodomain proteins and participates in patterning the hindbrain and retina during vertebrate CNS development. We characterized a Pbx4 cDNA isolated from a Gekko japonicus brain and spinal cord cDNA library. Northern blot and quantitative real-time PCR revealed that gecko Pbx4 was ubiquitously expressed in several tissues. In the spinal cord after tail amputation, in situ hybridization results showed that Pbx4 mRNA staining was present in the gray matter and ependymal cells of the spinal cord but that additional staining was seen in the white matter in regions close to the amputation stump. Both in situ hybridization and real-time PCR methods detected no obvious changes in Pbx4 expression in segment of the cord farthest from the amputation site, however, Pbx4 mRNA expression increased by 2 fold in segment close to the amputation site after 2wks. The upregulation of Pbx4 was inhibited by an intraperitoneal injection of retinoic acid (RA) (100μg/g body weight). These results suggest that gecko Pbx4 is possibly involved in spinal cord regeneration at sites of proximal amputation, and that the expression of Pbx4 in the spinal cord is regulated by retinoic acid in a manner different from that of Pbx1, Pbx2 and Pbx3. [Copyright &y& Elsevier]

Purpose: To evaluate the clinical performance of a newly developed three-dimensional (3D) intra- and extracranial arterial vessel wall joint imaging technique at 3T using T1-weighted 3D variable-flip-angle turbo spin-echo sequence with improved cerebrospinal fluid suppression in patients with cerebrovascular disease.Materials and Methods: 122 consecutive patients (mean age 45.96 ± 12.16 years) with clinically confirmed cerebrovascular symptoms were imaged using a 3D intra- and extracranial arterial vessel wall joint imaging sequence with and without contrast enhancement on a 3 T MR system. The number of plaques and culprit plaques were evaluated. The image quality score, percent stenosis, remodeling ratio, and plaque burden were measured and compared between intracranial and carotid arterial plaques, and between non-culprit and culprit plaques.Results: Except for 23 patients, there were 322 plaques (111 culprit plaques) detected in 96 patients with large artery atherosclerosis. Of the plaques, 278 (96 culprit plaques) and 44 (15 culprit plaques) plaques were identified in intracranial and extracranial arteries, respectively. Image quality did not differ significantly between pre- and post-contrast vessel wall magnetic resonance images. There were also no significant differences in the percent stenosis, remodeling ratio, and plaque burden between intracranial and carotid arteries, and between non-culprit and culprit plaques. The enhancement rate of culprit plaques was significantly higher than that of non-culprit plaques.Conclusions: The described joint imaging is a promising vessel wall magnetic resonance imaging method for comprehensive diagnosis of cerebrovascular symptoms and investigation of etiology. The imaging technique is a potentially valuable means to optimize treatment. [ABSTRACT FROM AUTHOR]