Investigation of wear behavior of aged and non-aged SiC-reinforced AlSi7Mg2 metal matrix composites in dry sliding conditions

Metal matrix composites (MMCs) with their splendid mechanical properties have been specifically designed for use in fields such as aerospace and aviation. The presence of hard ceramic particles in MMC increases the hardness of the matrix product and decreases its coefficient of friction. Therefore, the wear resistance is improved. Moreover, the mechanical properties of these composite materials can be improved by applying heat treatments. In this study, AlSi7Mg2 MMCs with 15 wt% SiC reinforcement were produced by squeeze casting technique. Some of the composites were aged by heat treatment. Hardness values of aged and non- aged composites were compared. In addition, abrasive wear behaviors of these composites were investigated on pin-on-disk device, depending on the load (7, 12 and 17 N), the sliding speed (0.2, 0.3 and 0.4 m/s) and the sliding distance (700, 1000 and 1300 m). Worn surfaces were also analyzed by scanning electron microscopy (SEM). As a result of the analyses, it was determined that both the hardness values and the wear resistance were higher in the composites subjected to aging treatment. Furthermore, it was observed that the increase in the applied load led up to the weight loss. The increase in the sliding distance increased both friction coefficient and weight loss. The increase in sliding speed also made way for the friction coefficient but ensured less weight loss. When SEM images were examined, it was ascertained that deformation and tribo-surface formation had a significant effect on weight losses

Spatially informed voxelwise modeling for naturalistic fMRI experiments

Voxelwise modeling (VM) is a powerful framework to predict single voxel responses evoked by a rich set of stimulus features present in complex natural stimuli. However, because VM disregards correlations across neighboring voxels, its sensitivity in detecting functional selectivity can be diminished in the presence of high levels of measurement noise. Here, we introduce spatially-informed voxelwise modeling (SPIN-VM) to take advantage of response correlations in spatial neighborhoods of voxels. To optimally utilize shared information, SPIN-VM performs regularization across spatial neighborhoods in addition to model features, while still generating single-voxel response predictions. We demonstrated the performance of SPIN-VM on a rich dataset from a natural vision experiment. Compared to VM, SPIN-VM yields higher prediction accuracies and better capture locally congruent information representations across cortex. These results suggest that SPIN-VM offers improved performance in predicting single-voxel responses and recovering coherent information representations

Career and Talent Development Self-Efficacy Scale: Adaptation and Validation in the Turkish Population

The aim of the study is to adapt and conduct reliability and validity studies of the Career and Talent Development Self-Efficacy Scale. Participants were 1047 students in İstanbul. To assess content validity, expert consultancy was utilized and to assess construct validity confirmatory factor analysis was utilized. Reliability of the scale was examined with Cronbach’s Alpha, split-half reliability, test of upper and lower 27% of the groups in terms of item mean differences. Confirmatory factor analysis results showed that chi-square was significant (χ2 = 719.30, SD = 130, p = .00); and fit indices were as follows RMSEA = .066, GFI = .93, AGFI = .91, CFI = .93, IFI = .93, NFI = .91, RFI = .90, SRMR = .041. According to the model results provided a good fit to the data and factor structure in the Turkish form was parallel to the original factor structure. In terms of reliability, internal consistency reliability was. 92 and split-half reliability was. 86. Furthermore, corrected item total correlations were ranged between. 49 and. 67 and all the differences between upper and lower 27% groups were significant. The results of the analysis supported the conclusion that the Turkish form of Career and Talent Development Scale is a reliable and valid measurement tool

Diyarbakır Yöresindeki Çiğ Koyun Sütlerinin Mikrobiyolojik, Fiziko-Kimyasal ve Organoleptik Özelliklerinin Araştırılması

Bu çalışmada Diyarbakır İlinde 100 farklı çiftlikten toplanan koyun sütlerinin bileşimi ve kalite özellikleri ile muhtemel halk sağlığı risklerinin belirlenmesi amaçlanmıştır. Koyun sütü örneklerindeki ortalama toplam mezofilik aerob bakteri, toplam psikrofilik aerob bakteri, koliform, Escherichia coli, Staphylococcus-Micrococcus spp., laktobasil, laktik streptokok, küf-maya ile sülfit redükte eden anaerob bakteri sayıları sırası ile 7.83, 6.92, 4.55, 3.61, 4.50, 6.23, 7.95, 4.27 ve 2.71 log10 kob/ml olarak saptanmıştır. Analiz edilen koyun sütlerinde ortalama yağ, yağsız kuru madde, protein, laktoz ve mineral madde miktarları ile yoğunluk, donma noktası ve pH değerleri ise sırası ile %7.93, %11.88, %4.96, % 5.99, %0.77, 1.035, -0.615 °C ve 6.55’tir. Koyun sütü örneklerindeki ortalama somatik hücre sayısı 5.77 log10 hücre/ml; kıvam, görünüm-renk, tat ve koku puanları ise sırasıyla 5.0, 4.0, 5.0 ve 4.5 olarak tespit edilmiştir (5’li skala). Diyarbakır’dan temin edilen koyun sütlerinin beslenme ve endüstriyel açıdan önemli bir potansiyel oluşturduğu, ancak hijyenik kalitelerinin düşük olduğu saptanmıştır. Koyun yetiştiricilerinin sağım hijyeni ve sütün muhafazası hakkında eğitilmesine ihtiyaç bulunduğu kanaatine varılmıştır

The in vitro and in vivo investigation of biological activities and phenolic analysis of Helichrysum plicatum subsp. plicatum

In Turkey, Helichrysum genus is represented by 26 taxa belonging to 20 species in Turkish flora of which 14 ones are endemic to Turkey. The aerial parts of Helichrysum plicatum subsp. plicatum are used kidney stones, kidney and stomach ailments. The extraction procedures and solvents are important step in processing of bioactive constituents from the plant materials. Therefore, the aim of this study was to evaluate in vitro antioxidant, antimicrobial, anti-urease, anticholinesterase and in vivo antiinflammatory activities of Helichrysum plicatum subsp. plicatum different extracts. In addition, the phenolic characterization of the Soxhlet and maceration methanol extracts which showed significant antioxidant, anti-urease, antimicrobial, anti-inflammatory and anticholinesterase activities were performed by HPLC-DAD and LC-MS/MS. In the present study, the Soxhlet methanol extract exhibited strong antioxidant, antimicrobial and anticholinesterase activities than other extracts. The maceration methanol extract showed the strongest anti-urease activity. The Soxhlet methanol and maceration methanol extracts showed in vivo anti-inflammatory activities very close to each other. As a result of this study, chlorogenic acid, dicaffeoylquinic acid, luteolin, luteolin-7-O-glucoside, naringenin-O-hexoside and isoquercitrin compounds were analysed in plant. Therefore, it is thought that methanol extracts can be used as a natural source in the future for food and pharmaceutical industries

Inherited Bone Marrow Failure Syndromes in Children

Inherited bone marrow failure syndromes are disorders of hematopoiesis that are mostly encountered in childhood. Taking the basis from genetics, they are characterized by pancytopenia, increased risk of developing myelodysplastic syndrome and malignancy. Extrahematopoietic presentations are observed often in addition to symptoms related to defective hematopoiesis (also known as bone marrow failure). The biology, clinical features, and management of the main syndromes such as Fanconi anemia, dyskeratosis congenita, Shwachman-Diamond syndrome, congenital amegakaryocytic thrombocytopenia, Diamond-Blackfan anemia, and severe congenital neutropenia are briefly summarized in this review

Spatially informed voxelwise modeling for naturalistic fMRI experiments

Voxelwise modeling (VM) is a powerful framework to predict single voxel responses evoked by a rich set of stimulus features present in complex natural stimuli. However, because VM disregards correlations across neighboring voxels, its sensitivity in detecting functional selectivity can be diminished in the presence of high levels of measurement noise. Here, we introduce spatially-informed voxelwise modeling (SPIN-VM) to take advantage of response correlations in spatial neighborhoods of voxels. To optimally utilize shared information, SPIN-VM performs regularization across spatial neighborhoods in addition to model features, while still generating single-voxel response predictions. We demonstrated the performance of SPIN-VM on a rich dataset from a natural vision experiment. Compared to VM, SPIN-VM yields higher prediction accuracies and better capture locally congruent information representations across cortex. These results suggest that SPIN-VM offers improved performance in predicting single-voxel responses and recovering coherent information representations

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

SYNTHESIS AND INVESTIGATION OF SOME PROPERTIES OF AZO COMPOUNDS PREPARED FROM 1,3-DIMETHYLBARBITURIC ACİDWITH VARIOUS DIAZOTIZED CARBOCYCLIC AND HETEROCYCLIC AMINES

Bu çalışmada diazolanan çeşitli karboksiklik ve heterosiklik aminlerin 1,3-dimetilbarbütirik asit ile kenetlenmesinden iki seri azo dispers boyarmaddeleri sentezlendi. Bileşiklerin yapıları FT-IR, 1H-NMR, UV, MS spektrometresi ve element analizleriyle aydınlatıldı. Boyarmaddelerin absorpsiyon spektrumları çeşitli çözücüler içinde incelendi ve çözeltide azo-hidrazon tautomerleşme dengesi tartışıldı. Boyarmaddelerin absorpsiyon spektrumları üzerine sübstitüent ve çözücü etkisi ayrıntılı olarak incelendi.In this study, two series of azo disperse dyes have been prepared by subsequent diazotization of various carbocyclic and heterocyclic amines and coupling with 1,3-dimethylbarbituric acid. The structures of the compounds were evaluated by FT-IR, 1H-NMR, UV, MS spectra and elemental analysis. Absorption spectra of the dyes were examined in various solvents and azo-hydrazone tautomeric equilibria in solution were discussed. The substituent and solvent effects on the absorption spectra of the dyes were examined in detail