Fire resistance of a damaged building employing buckling restrained braced system

This study investigates the influence of buckling restrained brace systems (BRBs) on the overall structural stability against fire following a severe incident, which caused the failure of a column on the first storey of a steel building. A four-storey moment frame fitted with the inverted-V arrangement of braces is modelled, considering a multi-hazard approach. This technique concentrates on a structural plane frame that is designed to meet the progressive collapse criteria according to the U.S. Department of Defense guidelines and assumes that an extreme event damaged a first-storey centre column, before the exposure to an ensuing fire. The performance of BRBs in preventing the global collapse of the structure due to a post-event fire is compared with that of ordinary concentric brace systems (OCBs). The results indicate that BRBs offer a higher global collapse time to the building owing to the greater stiffness they provide to the structural frame. The fire resistance provided by BRBs is restricted to the participation of bracing elements and framing girders afterwards. In the case of OCBs, columns contribute to the structural resistance prior to the full capacity of braces used. To conclude, it is found that BRBs are more capable in maintaining the stability of a damaged building against fire resulting from an extreme event than OCBs. © 2018, Hong Kong Institute of Steel Construction

Sperm DNA fragmentation: A new guideline for clinicians

Sperm DNA integrity is crucial for fertilization and development of healthy offspring. The spermatozoon undergoes extensive molecular remodeling of its nucleus during later phases of spermatogenesis, which imparts compaction and protects the genetic content. Testicular (defective maturation and abortive apoptosis) and post-testicular (oxidative stress) mechanisms are implicated in the etiology of sperm DNA fragmentation (SDF), which affects both natural and assisted reproduction. Several clinical and environmental factors are known to negatively impact sperm DNA integrity. An increasing number of reports emphasizes the direct relationship between sperm DNA damage and male infertility. Currently, several assays are available to assess sperm DNA damage, however, routine assessment of SDF in clinical practice is not recommended by professional organizations

dargiri

درگیری تحصیلی یکی از مفاهیمی است که در سالهای اخیر توسط پژوهشگران مختلف بهکاربرده شده و بهکیفیت درگیری دانشجویان در فعالیتهای هدفمند آموزشی اشاره میکند سنجش میزان درگیری دانشجویاندر افزایش میزان یادگیری آنان و خصوصاً در مورد دانشجویانی که درخطر مردود شدن قرار دارند، نقشمحوری دارد. این پژوهش باهدف تحلیل عاملی اکتشافی و تأییدی مقیاس درگیری تحصیلی انجام شد.روش پژوهش از نوع همبستگی است. جامعه آماری کلیه دانشجویان دانشگاه پیام نور استان فارس می باشندبرای تعیین حجم نمونه، از فرمول کرجسی و مورگان و روش نمونهگیری خوشه ای استفا ده شد. داده ها ازطریق تحلیل عاملی اکتشافی و تأییدی بررسی شد. تحلیل عاملی اکتشافی، به کشف سه خرده مقیاس منجرشد و تحلیل عاملی قرار گرفتن مؤلفههای مذکور را در زیر سازههای درگیری تحصیلی تأیید کرد. درمجموع ،مقیاس اصلاحشده درگیری تحصیلی از روایی و پایایی مطلوب برخوردار است و میتوان از آن برای ارزیابیباورهای درگیری تحصیلی دانشجویان استفاده کرد

NGLY1 deficiency: Novel variants and literature review

NGLY1 deficiency is a recently described autosomal recessive disorder, involved in deglycosylation of proteins, and for that reason grouped as the congenital disorders of deglycosylation together with the lysosomal storage disorders. The typical phenotype is characterized by intellectual disability, liver malfunctioning, muscular hypotonia, involuntary movements, and decreased or absent tear production. Liver biopsy demonstrates vacuolar amorphous cytoplasmic storage material. NGLY1 deficiency is caused by bi-allelic variants in NGLY1 which catalyzes protein deglycosylation. We describe five patients from two families with NGLY1 deficiency due to homozygosity for two novel NGLY1 variants, and compare their findings to those of earlier reported patients. The typical features of the disorder are present in a limited way, and there is intra-familial variability. In addition in one of the families the muscle atrophy and posture abnormalities are marked. These can be explained either as variability of the phenotype or as sign of slowly progression of features as the present affected individuals are older than earlier reported patients