Flexural Strength of Innovative Thin-Walled Composite Cold-Formed Steel/PE-ECC Beams

A detailed experimental investigation on the flexural behaviour of an innovative precast composite element combining cold-formed steel (CFS) and engineered cementitious composites (ECC) is presented in this paper. Bonding ECC to the lightweight thin-walled CFS sections enhanced the buckling, bearing, and torsional properties of the composite sections. The proposed composite system will be used as precast flexural members in framed structures with large spans or as a rehabilitation approach for corroded cold-formed and hot-rolled steel flexural members. Simply supported beams with comparatively long spans with span-to-depth ratios of 6.83 and 13.48 were installed back-to-back and tested under a 4-point loading configuration. The behaviour of composite CFS/ECC beams under bending was investigated and compared with the bare CFS sections. Composite CFS/MOR beams incorporating high-strength mortar (MOR) as an ECC replacement were also investigated. The test specimens were divided into three series with sixteen tests in total. Series A (SC300) included six tests utilising 300-mm height SupaCee sections, Series B (C300) included four tests using 300-mm height lipped-Cee sections, and Series C (SC150) included six tests utilising 150-mm height SupaCee sections. The composite CFS/ECC beams exhibited high load-bearing capacities after reaching their plastic section capacities, while the bare CFS beams failed to reach their yield section capacities due to distortional buckling. Composite CFS/MOR beams could not reach their plastic moment capacities due to debonding between MOR and CFS after MOR crushing. The moment capacities of the composite CFS/ECC beams increased up to 140.0% over their duplicate bare CFS sections, while composite CFS/MOR beams showed only a 72.0% increase over CFS sections. Lastly, design equations to predict the moment capacity of composite CFS/ECC beams are presented, based on the experimental results

Molecular identification of adenoviruses associated with respiratory infection in Egypt from 2003 to 2010.

BACKGROUND: Human adenoviruses of species B, C, and E (HAdV-B, -C, -E) are frequent causative agents of acute respiratory infections worldwide. As part of a surveillance program aimed at identifying the etiology of influenza-like illness (ILI) in Egypt, we characterized 105 adenovirus isolates from clinical samples collected between 2003 and 2010. METHODS: Identification of the isolates as HAdV was accomplished by an immunofluorescence assay (IFA) and confirmed by a set of species and type specific polymerase chain reactions (PCR). RESULTS: Of the 105 isolates, 42% were identified as belonging to HAdV-B, 60% as HAdV-C, and 1% as HAdV-E. We identified a total of six co-infections by PCR, of which five were HAdV-B/HAdV-C co-infections, and one was a co-infection of two HAdV-C types: HAdV-5/HAdV-6. Molecular typing by PCR enabled the identification of eight genotypes of human adenoviruses; HAdV-3 (n = 22), HAdV-7 (n = 14), HAdV-11 (n = 8), HAdV-1 (n = 22), HAdV-2 (20), HAdV-5 (n = 15), HAdV-6 (n = 3) and HAdV-4 (n = 1). The most abundant species in the characterized collection of isolates was HAdV-C, which is concordant with existing data for worldwide epidemiology of HAdV respiratory infections. CONCLUSIONS: We identified three species, HAdV-B, -C and -E, among patients with ILI over the course of 7 years in Egypt, with at least eight diverse types circulating

Hypoxia upregulates expression of human endosialin gene via hypoxia-inducible factor 2

Endosialin is a transmembrane glycoprotein selectively expressed in blood vessels and stromal fibroblasts of various human tumours. It has been functionally implicated in angiogenesis, but the factors that control its expression have remained unclear. As insufficient delivery of oxygen is a driving force of angiogenesis in growing tumours, we investigated whether hypoxia regulates endosialin expression. Here, we demonstrate that endosialin gene transcription is induced by hypoxia predominantly through a mechanism involving hypoxia-inducible factor-2 (HIF-2) cooperating with the Ets-1 transcription factor. We show that HIF-2 activates the endosialin promoter both directly, through binding to a hypoxia-response element adjacent to an Ets-binding site in the distal part of the upstream regulatory region, and indirectly, through Ets-1 and its two cognate elements in the proximal promoter. Our data also suggest that the SP1 transcription factor mediates responsiveness of the endosialin promoter to high cell density. These findings elucidate important aspects of endosialin gene regulation and provide a rational frame for future investigations towards better understanding of its biological significance

Pooled analysis of WHO Surgical Safety Checklist use and mortality after emergency laparotomy

Background The World Health Organization (WHO) Surgical Safety Checklist has fostered safe practice for 10 years, yet its place in emergency surgery has not been assessed on a global scale. The aim of this study was to evaluate reported checklist use in emergency settings and examine the relationship with perioperative mortality in patients who had emergency laparotomy. Methods In two multinational cohort studies, adults undergoing emergency laparotomy were compared with those having elective gastrointestinal surgery. Relationships between reported checklist use and mortality were determined using multivariable logistic regression and bootstrapped simulation. Results Of 12 296 patients included from 76 countries, 4843 underwent emergency laparotomy. After adjusting for patient and disease factors, checklist use before emergency laparotomy was more common in countries with a high Human Development Index (HDI) (2455 of 2741, 89.6 per cent) compared with that in countries with a middle (753 of 1242, 60.6 per cent; odds ratio (OR) 0.17, 95 per cent c.i. 0.14 to 0.21, P <0001) or low (363 of 860, 422 per cent; OR 008, 007 to 010, P <0.001) HDI. Checklist use was less common in elective surgery than for emergency laparotomy in high-HDI countries (risk difference -94 (95 per cent c.i. -11.9 to -6.9) per cent; P <0001), but the relationship was reversed in low-HDI countries (+121 (+7.0 to +173) per cent; P <0001). In multivariable models, checklist use was associated with a lower 30-day perioperative mortality (OR 0.60, 0.50 to 073; P <0.001). The greatest absolute benefit was seen for emergency surgery in low- and middle-HDI countries. Conclusion Checklist use in emergency laparotomy was associated with a significantly lower perioperative mortality rate. Checklist use in low-HDI countries was half that in high-HDI countries.Peer reviewe

Global variation in anastomosis and end colostomy formation following left-sided colorectal resection

Background End colostomy rates following colorectal resection vary across institutions in high-income settings, being influenced by patient, disease, surgeon and system factors. This study aimed to assess global variation in end colostomy rates after left-sided colorectal resection. Methods This study comprised an analysis of GlobalSurg-1 and -2 international, prospective, observational cohort studies (2014, 2016), including consecutive adult patients undergoing elective or emergency left-sided colorectal resection within discrete 2-week windows. Countries were grouped into high-, middle- and low-income tertiles according to the United Nations Human Development Index (HDI). Factors associated with colostomy formation versus primary anastomosis were explored using a multilevel, multivariable logistic regression model. Results In total, 1635 patients from 242 hospitals in 57 countries undergoing left-sided colorectal resection were included: 113 (6·9 per cent) from low-HDI, 254 (15·5 per cent) from middle-HDI and 1268 (77·6 per cent) from high-HDI countries. There was a higher proportion of patients with perforated disease (57·5, 40·9 and 35·4 per cent; P < 0·001) and subsequent use of end colostomy (52·2, 24·8 and 18·9 per cent; P < 0·001) in low- compared with middle- and high-HDI settings. The association with colostomy use in low-HDI settings persisted (odds ratio (OR) 3·20, 95 per cent c.i. 1·35 to 7·57; P = 0·008) after risk adjustment for malignant disease (OR 2·34, 1·65 to 3·32; P < 0·001), emergency surgery (OR 4·08, 2·73 to 6·10; P < 0·001), time to operation at least 48 h (OR 1·99, 1·28 to 3·09; P = 0·002) and disease perforation (OR 4·00, 2·81 to 5·69; P < 0·001). Conclusion Global differences existed in the proportion of patients receiving end stomas after left-sided colorectal resection based on income, which went beyond case mix alone

Effects of Anacetrapib in Patients with Atherosclerotic Vascular Disease

BACKGROUND: Patients with atherosclerotic vascular disease remain at high risk for cardiovascular events despite effective statin-based treatment of low-density lipoprotein (LDL) cholesterol levels. The inhibition of cholesteryl ester transfer protein (CETP) by anacetrapib reduces LDL cholesterol levels and increases high-density lipoprotein (HDL) cholesterol levels. However, trials of other CETP inhibitors have shown neutral or adverse effects on cardiovascular outcomes. METHODS: We conducted a randomized, double-blind, placebo-controlled trial involving 30,449 adults with atherosclerotic vascular disease who were receiving intensive atorvastatin therapy and who had a mean LDL cholesterol level of 61 mg per deciliter (1.58 mmol per liter), a mean non-HDL cholesterol level of 92 mg per deciliter (2.38 mmol per liter), and a mean HDL cholesterol level of 40 mg per deciliter (1.03 mmol per liter). The patients were assigned to receive either 100 mg of anacetrapib once daily (15,225 patients) or matching placebo (15,224 patients). The primary outcome was the first major coronary event, a composite of coronary death, myocardial infarction, or coronary revascularization. RESULTS: During the median follow-up period of 4.1 years, the primary outcome occurred in significantly fewer patients in the anacetrapib group than in the placebo group (1640 of 15,225 patients [10.8%] vs. 1803 of 15,224 patients [11.8%]; rate ratio, 0.91; 95% confidence interval, 0.85 to 0.97; P=0.004). The relative difference in risk was similar across multiple prespecified subgroups. At the trial midpoint, the mean level of HDL cholesterol was higher by 43 mg per deciliter (1.12 mmol per liter) in the anacetrapib group than in the placebo group (a relative difference of 104%), and the mean level of non-HDL cholesterol was lower by 17 mg per deciliter (0.44 mmol per liter), a relative difference of -18%. There were no significant between-group differences in the risk of death, cancer, or other serious adverse events. CONCLUSIONS: Among patients with atherosclerotic vascular disease who were receiving intensive statin therapy, the use of anacetrapib resulted in a lower incidence of major coronary events than the use of placebo. (Funded by Merck and others; Current Controlled Trials number, ISRCTN48678192 ; ClinicalTrials.gov number, NCT01252953 ; and EudraCT number, 2010-023467-18 .)

Flexural Strength of Innovative Thin-Walled Composite Cold-Formed Steel/PE-ECC Beams

A detailed experimental investigation on the flexural behaviour of an innovative precast composite element combining cold-formed steel (CFS) and engineered cementitious composites (ECC) is presented in this paper. Bonding ECC to the lightweight thin-walled CFS sections enhanced the buckling, bearing, and torsional properties of the composite sections. The proposed composite system will be used as precast flexural members in framed structures with large spans or as a rehabilitation approach for corroded cold-formed and hot-rolled steel flexural members. Simply supported beams with comparatively long spans with span-to-depth ratios of 6.83 and 13.48 were installed back-to-back and tested under a 4-point loading configuration. The behaviour of composite CFS/ECC beams under bending was investigated and compared with the bare CFS sections. Composite CFS/MOR beams incorporating high-strength mortar (MOR) as an ECC replacement were also investigated. The test specimens were divided into three series with sixteen tests in total. Series A (SC300) included six tests utilising 300-mm height SupaCee sections, Series B (C300) included four tests using 300-mm height lipped-Cee sections, and Series C (SC150) included six tests utilising 150-mm height SupaCee sections. The composite CFS/ECC beams exhibited high load-bearing capacities after reaching their plastic section capacities, while the bare CFS beams failed to reach their yield section capacities due to distortional buckling. Composite CFS/MOR beams could not reach their plastic moment capacities due to debonding between MOR and CFS after MOR crushing. The moment capacities of the composite CFS/ECC beams increased up to 140.0% over their duplicate bare CFS sections, while composite CFS/MOR beams showed only a 72.0% increase over CFS sections. Lastly, design equations to predict the moment capacity of composite CFS/ECC beams are presented, based on the experimental results

Axial Compressive Behaviour of Thin-Walled Composite Columns Comprise High-Strength Cold-Formed Steel and Pe-Ecc

A new form of thin-walled composite columns, made of high-strength cold-formed steel (CFS) open sections and thin layers of engineered cementitious composites (ECC), is presented in this paper. The axial behaviour of columns with slenderness ratios (le/r) ranging between 10.08 and 13.86 under concentric loads were experimentally investigated. Twelve column specimens were divided into four groups of bare CFS columns, plain ECC columns, composite columns with SupaCee sections, and composite columns with Lipped-Cee sections. A specific ECC mixture with three PE-fibre contents: 0.75%, 1.75%, and 2.25% by mix volume, was placed in the tested columns in two thin thicknesses of 16.0 mm and 26.0 mm. Additionally, a high-strength concrete (HSC) mixture was utilised in two test columns for comparison with ECC. The results revealed that the composite CFS/ECC columns exhibited enhanced axial compressive capacities up to 2.79 times that of the bare CFS columns. The ductility indices and compressive toughness of the composite CFS/ECC columns were improved to 1.56 and 3.85 times those of the bare CFS columns, respectively. Strength prediction equations were developed based on the experimental observations to estimate the axial compressive capacity of composite CFS/ECC columns susceptible to local buckling

Structural Performance of Novel Thin-Walled Composite Cold-Formed Steel/PE-ECC Beams

A novel form of thin-walled composite beams has been developed by bonding cold-formed steel (CFS) and engineered cementitious composites (ECC). Apart from the superior material strength and ductility of CFS and ECC, the proposed CFS/ECC composite system also benefits from the lightweight concept of thin-walled sections and improved buckling performance due to the ECC restraints on CFS. An experimental study, utilising cold-formed steel sections with a yield strength of 450 MPa and engineered cementitious composites with an ultimate tensile strength of 7 MPa, was conducted to investigate the improvement of the innovated structural system over the traditional CFS structures. Two series of composite CFS/ECC beams, namely, short- and long-span Series, were prepared and tested to monitor the shear and flexural behaviours of the novel composite system. Three locations of thin-layered ECC; outside, inside, and in–out of the CFS section were proposed to determine the perfect composite action between ECC and CFS. The load capacity of the composite beams (ECC—in composite beams) increased to eight times those of the bare CFS members in the short-span Series and up to four times in the long-span Series. The failure modes of the novel composite beams were more ductile compared to the bare CFS. Numerical modelling was conducted and validated using the results obtained from the experimental study. This FE model was employed in a small-scale parametric study to investigate the influence of beam spans on the structural behaviour of the composite CFS/ECC beams