An investigation of the behavior of header end-plate connections under monotonic loading

In seismically active regions such as Turkey, the context of the nonlinearity provided by a building is based on the behaviors of structural components; beams, columns and their connections constituting the seismic force resisting system of the structure. Of these members, beam-to-column connections can play a considerably important role even if they have a capability of limited stiffness and flexural strength. Structural steel connections are mainly classified as a pinned or a moment connection. However, some beam-to-column connections having limited stiffness and flexural strength, which are called semi-rigid connections such as header end-plate connections designed so as to transmit only shear forces, can be characterized by moment-rotation relationship. This paper investigates the behavior of header end-plate connections using finite element (FE) modeling. The FE models include material, geometrical and contact nonlinearities. FE modeling technique was first verified through the test results of the experimental research performed by Aggarwal (1990). Then the effect of header end-plate thickness upon moment-rotation relationship was investigated. According to the analyses results, in addition to shear stresses, axial tensile stresses have been observed to occur in the bolts at the tension side and thickness of the header end-plate and beam web play a governing role in the development of initial rotational stiffness and the flexural strength of header end-plate connections

Acute effects of different types of exercises on insulin-like growth factor-1, homocysteine and cortisol levels in veteran athletes

This study aimed to investigate acute effects of table tennis(physical+cognitive exercise), aerobic running (physical exercise), and chess (cognitive exercise) exercise sessions of veteran male athletes in their branches on the serum homocysteine (Hcy), insulin growth factor-1 (IGF-1), and cortisol (Cor) levels. Thirty veteran athletes [10 table tennis players (TT), 10 long-distance runners (LR), 10 chess players (CP)] and 10 sedentary controls (SC) between 50 and 65 years of age participated in the study. Blood samples were obtained before and immediately after exercise to determine serum Hcy, IGF-1, and Cor levels. According to their branch, each veteran athlete performed exercise sessions (70-75% of the participants' heart rate reserve) of 10-min of warm-up followed by 40-min of table tennis, aerobic running, or chess. TT and LR groups demonstrated significant increases in the serum IGF-1, Cor, and Hcy levels from pre to post-exercise (p0.05). LR group had a greater serum Cor increase than all exercise groups (p<0.05). The TT group showed significantly greater changes in serum Cor levels than the CP group (p<0.05). In conclusion, although a single bout of aerobic running and table tennis exercise induces a remarkable increase in all measured biomarkers, chess exercise only elicits an increase in Hcy levels. Although aerobic running is more effective in increasing Cor levels than other types of exercise, the current study's findings suggest that serum Hcy and IGF-1 levels in veteran male athletes are not affected by the type of exercise

The serum amyloid-a, haptoglobin, ceruloplasmin and albumin levels in dogs which are infected with babesia canis

Bu çalışmada Babesia canis ile doğal enfekte köpeklerde serum haptoglobin (Hp), serum amiloid-A (SAA), seruloplazmin (Cp)ve albümin (Alb) seviyelerinin belirlenmesi amaçlanmıştır. Çalışmanın materyalini, Kafkas Üniversitesi Veteriner Fakültesi İç Hastalıkları Anabilim Dalı kliniklerine getirilen, kan frotilerinin giemsa yöntemi ile boyanması sonucunda B. canis tanısı konulan 20 hasta köpek oluşturdu. Kontrol amacı ile 10 sağlıklı köpek kullanıldı. Hasta hayvanların serum Hp, SAA, Cp ve Alb seviyeleri sırasıyla 0.44±0.12 mg/mL, 43.18±13.77 µg/mL, 10.75±2.45 mg/dL, 2.74±0.15 g/dL olarak belirlendi. Sağlıklı hayvanların serum Hp, SAA, Cp ve Alb değerleri ise sırasıyla 1.84±0.29 mg/mL, 1.18±0.40 µg/mL, 4.80±0.53 mg/dL, 3.01±0.34 g/dL olarak ölçüldü. Hasta hayvanların SAA ve Cp değerleri sağlıklı hayvanlara göre daha yüksek bulunurken (P<0.001), Hp (P<0.001) ve Alb (P<0.01) seviyelerinin daha düşük olduğu belirlendi. Sonuç olarak köpeklerde B. canis enfeksiyonunda serum SAA ve Cp değerleri yükselirken, Hp ve Alb seviyelerinin düştüğü belirlendi.In this study, we aimed to determine the serum haptoglobin (Hp), serum amyloid-A (SAA), ceruloplasmin (Cp) and albümin (Alb) levels in the dogs which are naturally infected with Babesia canis. 20 patient dogs which were diagnosed as B. canis by staining of their blood smears with giemsa method, which were brought to Kafkas University Veterinary Faculty Internal Medicine Department clinics formed the material of the study. 10 Healthy dogs were used for control. The serum Hp, SAA, Cp and Alb levels of the sick animals were determined as 0.44±0.12 mg/mL, 43.18±13.77 µg/mL, 10.75±2.45 mg/dL, 2.74±0.15 g/dL, respectively. Whereas, the serum Hp, SAA, Cp and Alb values of the healthy animals were measured as 1.84±0.29 mg/mL, 1.18±0.40 µg/mL, 4.80±0.53 mg/dL, 3.01±0.34 g/dL, respectively. While the SAA and Cp values of the sick animals were determined higher than that of the healthy animals, the (P <0.001), the Hp (P <0.001) and the Alb (P <0.01) levels were found to be lower. As a result, it was determined that the serum SAA and Cp levels increased, and the Hp and Alb levels decreased in the dogs which are infected with B. canis

Real-world efficacy and safety of Ledipasvir plus Sofosbuvir and Ombitasvir/Paritaprevir/Ritonavir +/- Dasabuvir combination therapies for chronic hepatitis C: A Turkish experience

Background/Aims: This study aimed to evaluate the real-life efficacy and tolerability of direct-acting antiviral treatments for patients with chronic hepatitis C (CHC) with/without cirrhosis in the Turkish population.Material and Methods: A total of 4,352 patients with CHC from 36 different institutions in Turkey were enrolled. They received ledipasvir (LDV) and sofosbuvir (SOF)+/- ribavirin (RBV) ombitasvir/paritaprevir/ritonavir +/- dasabuvir (PrOD)+/- RBV for 12 or 24 weeks. Sustained virologic response (SVR) rates, factors affecting SVR, safety profile, and hepatocellular cancer (HCC) occurrence were analyzed.Results: SVR12 was achieved in 92.8% of the patients (4,040/4,352) according to intention-to-treat and in 98.3% of the patients (4,040/4,108) according to per-protocol analysis. The SVR12 rates were similar between the treatment regimens (97.2%-100%) and genotypes (95.6%-100%). Patients achieving SVR showed a significant decrease in the mean serum alanine transaminase (ALT) levels (50.90 +/- 54.60 U/L to 17.00 +/- 14.50 U/L) and model for end-stage liver disease (MELD) scores (7.51 +/- 4.54 to 7.32 +/- 3.40) (p<0.05). Of the patients, 2 were diagnosed with HCC during the treatment and 14 were diagnosed with HCC 37.0 +/- 16.0 weeks post-treatment. Higher initial MELD score (odds ratio [OR]: 1.92, 95% confidence interval [CI]: 1.22-2.38; p=0.023]), higher hepatitis C virus (HCV) RNA levels (OR: 1.44, 95% CI: 1.31-2.28; p=0.038), and higher serum ALT levels (OR: 1.38, 95% CI: 1.21-1.83; p=0.042) were associated with poor SVR12. The most common adverse events were fatigue (12.6%), pruritis (7.3%), increased serum ALT (4.7%) and bilirubin (3.8%) levels, and anemia (3.1%).Conclusion: LDV/SOF or PrOD +/- RBV were effective and tolerable treatments for patients with CHC and with or without advanced liver disease before and after liver transplantation. Although HCV eradication improves the liver function, there is a risk of developing HCC.Turkish Association for the Study of The Liver (TASL

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

The Effect of Intravitreal Bevacizumab on Apoptosis of Rat Retina Cells

Pur po se: To investigate the apoptotic effects of intravitreal bevacizumab on rat retinal cells. Ma te ri al and Met hod: Thirty-six male adult Swiss albino rats were randomly divided into two groups. The first group was applied 0.25 mg bevacizumab in 0.01 ml saline, and the second group received the same amount of saline intravitreally. Each group was divided into 3 subgroups. The animals were sacrificed and their globes were enucleated at the 3rd, 24th, and 72nd hours of the experiment. Enucleated eyes were preserved for histological analysis, immunohistochemical analysis of caspase-3, caspase-8, caspase-9, Fas/Fas L, VEGF and VEGF receptors (Flt-1, Flk-1), and TUNEL staining. Re sults: Histological evaluation showed no sign of retinal toxicity in both groups. In TUNEL staining, TUNEL(+) cells were detected in all subgroups, but the number of positive cells was relatively lower in bevacizumab treatment group that reached statistically significant level at 24 and 72 hours of treatment (p<0.001). Immunohistochemical analysis revealed that in saline-treated subgroups, immunoreactivity was more pronounced for all apoptosis-inducing proteins compared to bevacizumab-treated group. Also immunoreactivity of VEGF was prominent in saline treated group. For VEGF receptors, staining was only positive for Flt-1 at the 3rd hour in the control group. Dis cus si on: Bevacizumab did not have apoptosis-inducing potential compared to saline solution in short term, which was documented with TUNEL and immunohistochemical staining. (Turk J Ophthalmol 2013; 43: 39-44

Effect of preparation method on the properties of polylactide/cellulose nanocrystal nanocomposites

Polylactide (PLA)/cellulose nanocrystal (CNC) nanocomposites with 1, 3, and 5 wt% CNC contents were prepared through (a) solution casting and (b) dilution of solution-casted PLA/CNC masterbatch though melt mixing in a twin-screw extruder. The effect of preparation method on the CNC dispersion quality and hence the final properties of the nanocomposites were studied. A better CNC dispersion within PLA was obtained when using solution casting method, whereas the formation of CNC agglomerates was observed in the melt-processed nanocomposites. The rheological results confirmed that a solid network was formed at the CNC content of around 3 wt% in the solution-casted samples. The PLA crystallization could also be enhanced differently in the presence of CNC nanoparticles through various preparation routes. Moreover, the CNC incorporation noticeably enhanced the storage modulus of PLA beyond its glass transition temperature. The oxygen permeability of PLA was also remarkably reduced with CNC by employing both methods

Effect of Mixing Strategy on the Structure-Properties of the PLA/PBAT Blends Incorporated with CNC

Polylactide (PLA)/poly (butylene adipate-co-terephthalate) (PBAT) blend nanocomposites including 3 wt% of cellulose nanocrystals (CNCs) were prepared by melt compounding method in a twin-screw extruder and an internal mixer. Blend nanocomposites were formulated by diluting three different masterbatches prepared by solution casting method that contained 7 wt% of CNC. These masterbatches were: (m1) PLA/PBAT/CNC masterbatch; (m2) PLA/CNC masterbatch; and (m3) PBAT/CNC masterbatch. These were to explore how different preparation methods affect the dispersion and localization of CNC and hence the properties of PLA/PBAT/CNC blend nanocomposites. Scanning electron microscopy (SEM) was used to study the structural changes of the blends. Rheological properties of PLA/PBAT blends and PLA/PBAT/CNC blend nanocomposites were also investigated. In the samples prepared by internal mixer, the rheological behavior of blend nanocomposite prepared through premixing of CNC particles with PLA showed a transition from liquid-like to a gel-like behavior. According to the rheological results and differential scanning calorimetry (DSC) analysis, it was found that the CNC overall enhanced the viscoelastic properties of blends and improved the PLA crystallization, respectively. Dynamic mechanical analysis (DMA) illustrated that the incorporation of CNC also enhanced the elastic modulus of PLA/PBAT blends specifically above the glass transition temperature of PLA. The expected improvements in mechanical properties did not occur due to the possible existence of residual solvent in the blends

Development of CNC-reinforced PBAT nanocomposites with reduced percolation threshold: a comparative study on the preparation method

Cellulose nanocrystal (CNC)-reinforced poly(butylene adipate-co-terephthalate) (PBAT) nanocomposites with CNC contents of 1, 3, and 5 wt% were prepared through either solution casting or dilution of a PBAT/CNC masterbatch through melt mixing. The efficiency of these preparation approaches on CNC dispersion quality was examined using transmission electron microscopy and rheological analysis. It was found that solution-casted nanocomposites possessed a much finer CNC dispersion, while melt mixing could cause the formation of CNC agglomerates. In the nanocomposites, the rheological percolation threshold through small-amplitude oscillatory shear experiments was determined to be around 2.18 and 3.15 wt% CNC, respectively. The PBAT melt crystallization was also promoted with CNC regardless of the preparation method. The oxygen permeability of PBAT remarkably reduced with the CNC incorporation, specifically in the solution-casted nanocomposites with finer CNC dispersion. The thermal degradation, thermomechanical, and mechanical properties of the nanocomposites were also compared although no significant differences were observed