Finite Element Analysis and Ambient Vibration Test of the Arch Type Steel Highway Bridges

In this paper, it is aimed to determine the dynamic characteristics of highway bridges using finite element analyses and ambient vibration tests. A modern steel highway bridge which has arch type structural system with 216 m total length and located in the Ayvacik county of Samsun, Turkey is selected as an application. Because of the fact that the bridge connects the villages which are separated with Suat Ugurlu Dam Lake, it has a major logistical importance for this region. The construction of the bridge is completed in 2009 and opened the traffic. An analytical modal analysis is performed on the developed 3D finite element model of the highway bridge to provide the analytical frequencies and mode shapes. The experimental measurements are carried out by ambient vibration tests under traffic loads. Vibration data are gathered from bridge deck. Measurement time, frequency span and effective mode number are determined by consider similar studies and literature. Enhanced Frequency Domain Decomposition method in the frequency domain and Stochastic Subspace Identification method in the time domain are used for the output only modal identification and dynamic characteristics such as natural frequencies, mode shapes and damping ratios are determined, experimentally. At the end of the study, analytically and experimentally identified dynamic characteristics are compared with each other. A good agreement is found between mode shapes, but some difference in natural frequencies

Burnout among surgeons before and during the SARS-CoV-2 pandemic: an international survey

Background: SARS-CoV-2 pandemic has had many significant impacts within the surgical realm, and surgeons have been obligated to reconsider almost every aspect of daily clinical practice. Methods: This is a cross-sectional study reported in compliance with the CHERRIES guidelines and conducted through an online platform from June 14th to July 15th, 2020. The primary outcome was the burden of burnout during the pandemic indicated by the validated Shirom-Melamed Burnout Measure. Results: Nine hundred fifty-four surgeons completed the survey. The median length of practice was 10 years; 78.2% included were male with a median age of 37 years old, 39.5% were consultants, 68.9% were general surgeons, and 55.7% were affiliated with an academic institution. Overall, there was a significant increase in the mean burnout score during the pandemic; longer years of practice and older age were significantly associated with less burnout. There were significant reductions in the median number of outpatient visits, operated cases, on-call hours, emergency visits, and research work, so, 48.2% of respondents felt that the training resources were insufficient. The majority (81.3%) of respondents reported that their hospitals were included in the management of COVID-19, 66.5% felt their roles had been minimized; 41% were asked to assist in non-surgical medical practices, and 37.6% of respondents were included in COVID-19 management. Conclusions: There was a significant burnout among trainees. Almost all aspects of clinical and research activities were affected with a significant reduction in the volume of research, outpatient clinic visits, surgical procedures, on-call hours, and emergency cases hindering the training. Trial registration: The study was registered on clicaltrials.gov "NCT04433286" on 16/06/2020

Preoperative serum placenta growth factor level as a new marker for stage II or III colorectal cancer patients

Background/aims: We first reported in this study that serum placenta growth factor and carcinoembryonic antigen in combination were useful markers for selecting early-stage colorectal cancer patients. The aim of the present study was to determine whether serum placenta growth factor could provide carcinoembryonic antigen-independent prognostic information on patients undergoing curative surgery. Methods: Serum and tissue samples were collected from 158 patients with colorectal cancer and from 50 controls. Serum and tissue levels of placenta growth factor were measured by enzyme-linked immunosorbent assay. The serum placenta growth factor levels in colorectal cancer patients were compared with those in healthy controls, and we retrospectively assessed the association between serum placenta growth factor levels and clinicopathological findings and survival. Results: Expression of placenta growth factor was significantly higher in colorectal cancer tissues compared with non-tumor tissues. The mean serum placenta growth factor level in patients was significantly higher than that in controls and significantly higher in patients with large tumor, lymph-node involvement and distant metastasis. Conclusions: Elevated serum placenta growth factor levels are significantly associated with colorectal cancer development, lymph or distant invasive phenotypes and survival, especially in stage II or III patients

Cadmium sulfide-induced toxicity in the cortex and cerebellum: In vitro and in vivo studies

Living organisms have an innate ability to regulate the synthesis of inorganic materials, such as bones and teeth in humans. Cadmium sulfide (CdS) can be utilized as a quantum dot that functions as a unique light-emitting semiconductor nanocrystal. The increased use in CdS has led to an increased inhalation and ingestion rate of CdS by humans which requires a broader appreciation for the acute and chronic toxicity of CdS. We investigated the toxic effects of CdS on cerebellar cell cultures and rat brain. We employed a ‘green synthesis’ biosynthesis process to obtain biocompatible material that can be used in living organisms, such as Viridibacillus arenosi K64. Nanocrystal formation was initiated by adding CdCl2 (1 mM) to the cell cultures. Our in vitro results established that increased concentrations of CdS (0.1 μg/mL) lead to decreased cell viability as assessed using 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT), total antioxidant capacity (TAC), and total oxidant status (TOS). The in vivo studies showed that exposure to CdS (1 mg/kg) glial fibrillary acidic protein (GFAP) and 8-hydroxy-2' -deoxyguanosine (8-OHdG) were increased. Collectively, we describe a model system that addresses the process from the synthesis to the neurotoxicity assessment for CdS both in vitro and in vivo. These data will be beneficial in establishing a more comprehensive pathway for the understanding of quantum dot-induced neurotoxicity

Adipose Tissue Gene Expression of Adiponectin, Tumor Necrosis Factor-alpha and Leptin in Metabolic Syndrome Patients with Coronary Artery Disease

WOS: 000289999800002PubMed ID: 21498926Objective Metabolic syndrome (MS) is associated with an increased risk of coronary artery disease (CAD) and type 2 diabetes mellitus (DM). In MS, adipose tissue has been shown to function as a paracrine and an endocrine organ secreting various adipocytokines. In the current study, adiponectin, tumor necrosis factor-alpha (TNF-alpha) and leptin gene expressions in the epicardial adipose tissue (EAT), paracardial adipose tissue (PAT) and subcutaneous adipose tissue (SAT) were investigated in MS patients with CAD and in non-MS patients without CAD. Methods and Results Thirty-seven patients with MS undergoing coronary artery bypass grafting due to CAD (MS group) and twenty-three non-MS patients without CAD undergoing heart valve surgery (control group) were recruited prospectively to the study. Relative gene expressions of adiponectin, TNF-alpha and leptin in EAT, PAT and SAT were compared between two groups of patients. Adiponectin gene expression in EAT and PAT were significantly lower in MS group compared to the control group (p < 0.0001, p=0.04, respectively) while SAT adiponectin gene expression did not differ significantly (p=0.64). TNF-alpha and leptin gene expressions were found to be statistically significantly higher in EAT, PAT and SAT of the MS group (p < 0.0001, for all). Conclusion Our results demonstrate that TNF-alpha and leptin gene expressions increase prominently in the EAT, PAT and SAT while adiponectin gene expression decreases significantly in EAT and PAT in MS patients with CAD. These findings suggest that disturbances in expression of adiponectin, TNF-alpha and leptin in EAT, PAT and SAT might play an important role in MS patients with CAD

The relationship among acute-phase response proteins, cytokines and hormones in cachectic patients with colon cancer

Abstract Backgraund Acute-phase response proteins (APRP), cytokines and hormones have been claimed to be an independent prognostic factor of malignancies, however the basis for their association with prognosis remains unexplained. We suggest that in colon malignancies, as similar to pancreatic and lung cancers, changes in APRP are associated with angiogenesis. Methods C-reactive protein (CRP), albumin, IL-1α, IL-1β, IL-6, IL-8, IL-10, TNF-α, midkine, VEGF-A, VEGF-C, leptin, adiponectin, and ghrelin serum levels are studied in 126 colon cancer patients and 36 healthy subjects. Results We found statistically significant difference and correlations between two groups. We found significantly higher serum CRP, IL-1α, IL-1β, IL-6, IL-8, IL-10, TNF-α, VEGF-A, VEGF-C and leptin concentrations in patients relative to controls (p Conclusions Cachexia in patients with colon cancers is associated with changes in APRP, cytokines and hormone concentrations. These biomarkers and cachexia together have a direct relationship with accelerated angiogenesis. This may lead to a connection between the outcomes in malignancies and the biomarkers.</p