Bifilm defects and porosity in Al cast alloys

Liquid Al and Mg-base alloys are so reactive that it is reasonable to assume that the surface layer is always oxidised. If liquid aluminium entered a mould cavity with a velocity greater than a critical value, the surface skin of the liquid metal would fold over onto itself and be submerged into the bulk liquid with a volume of air entrapped within it, creating what is called a bifilm defect. This defect not only acts as a crack but also it is recognized to initiate hydrogen porosity in the solidified casting, which has been found to have detrimental effects on the tensile and fatigue properties of the castings produced. Previous research suggested that during solidification the hydrogen, in excess of the solubility limit, comes out of solution and diffuses into the bifilm gap, expanding it into a pore. Also, placing liquid metal in a vacuum may cause its entrained bifilms to expand, enhancing their buoyancy and therefore their floatation to the surface of the melt. In this work, a casting from an A356 Al alloy was allowed to solidify under vacuum. The solidified casting was sectioned into two halves, and the internal surfaces of the pores were investigated using an SEM to determine their relationship with double oxide film defects

Solitary rectal ulcer syndrome (SRUS): observational case series findings on MR defecography

Objective: Radiological findings in solitary rectal ulcer syndrome (SRUS) are well described for evacuation proctography (EP) but sparse for magnetic resonance defecography (MRD). In order to rectify this, we describe the spectrum of MRD findings in patients with histologically proven SRUS. / Materials and methods: MRD from twenty-eight patients (18 female; 10 males) with histologically confirmed SRUS were identified. MRD employed a 1.5-T magnet and a standardized technique with the rectal lumen filled with gel and imaged sagittally in the supine position, before, during, and after attempted rectal evacuation. A single radiologist observer with 5 years’ experience in pelvic floor imaging made the anatomical and functional measurements. / Results: Sixteen patients (10 female) demonstrated internal rectal intussusception and 3 patients (11%) demonstrated complete external rectal prolapse. Anterior rectoceles were noted in 12 female patients (43%). Associated anterior and middle compartment weakness (evidenced by excessive descent) was observed in 18 patients (64%). Cystocele was found in 14 patients (50%) and uterine prolapse was noted in 7 patients (25%). Enterocoeles were detected in 5 patients (18%) and peritoneocoele in 5 patients (18%). None had sigmoidocoele. Sixteen patients (57%) demonstrated delayed voiding and 13 patients (46%) incomplete voiding, suggesting defecatory dyssynergia. / Conclusion: MRD can identify and grade both rectal intussusception and dyssynergia in SRUS, and also depict associated anterior and/or middle compartment descent. Distinction between structural and functional findings has important therapeutic implications. Key Points: MRD can identify and grade both rectal intussusception and dyssynergia in patients with SRUS. MRD is an acceptable substitute to evacuation proctography in assessing anorectal dysfunctions when attempting to avoid ionizing radiation. SRUS influences the pelvic floor globally. MRD depicts associated anterior and/or middle compartment prolapse

Molecular epidemiology of antibiotic-associated diarrhoea due to Clostridium difficile and clostridium perfringens in Ain Shams University Hospitals

Background: As we are living in the era of antibiotic overuse, antibiotic associated diarrhea (AAD) is considered now a distinct health problem with a need for more attention. Aim of the Study: was to perform a highly specific detection and definition of pathogenic Clostridium perfringens and Clostridium difficile related AAD in children compared to adults and geriatircs. Patients and Methods: One hundred and fifty patients diagnosed for AAD were included in this study (50 children, 50 adults and 50 geriatric patients). All of them were subjected to full medical history including complete therapeutic history of antibiotics and collection of stool sample during the attack for detection of Clostridium perfringenes enterotoxin (CPEnt) and Clostridium difficile cytotoxin by (EIA) kit. PCR detection of Clostridium perfringenes cpe gene (Coding gene for CPEnt) was performed as well. Results: Results showed that prevalence of Clostridium difficile cytotoxin was 24% while Clostridium perfringenes enterotoxin was 12% as detected by EIA in faecal specimens as a whole. Detection of cpe gene by PCR was positive in 16% of all cases. Children (OR: 4.2, 95% CI: 1.3-14.8, P_0.01) and geriatric patients (OR: 3.4, 95% CI: 1.2-13.5, P_0.02) were significantly more prone to Clostridium difficile AAD compared to adults. Also, childhood was a significant risk for Clostridium perfringens AAD (OR: 2.1, 95% CI: 0.54-7.4, P_0.04). In Conclusion: children and geriatric patients are more vulnerable to develop AAD with antibiotic abuse compared to adults. Abbreviations: AAD=Antibiotic associated diarrhea, CI=Confidence interval, ELISA=Enzyme-linked immunosorbent assay, OR=Odd ratio, PCR=Polymerase chain reaction. Keywords: Antibiotic-associated diarrhea, children, Clostridium perfringens, Clostridium difficile. Egypt. J. Hum. Genet Vol. 8 (2) 2007: pp. 121-13

(E)-N′-(4-Hy­droxy­benzyl­idene)-3-nitro­benzohydrazide

The mol­ecule of the title compound, C14H11N3O4, assumes an E conformation about the C=N double bond. The benzene rings form a dihedral angle of 3.9 (2)°. The crystal structure is stabilized by N—H⋯O, O—H⋯N, O—H⋯O and C—H⋯O hydrogen bonds, forming layers parallel to (101). In addition, intra­layer π–π stacking inter­actions [centroid–centroid distance = 3.635 (2) Å] are observed

N′-[(2-Methoxynaphthalen-1-yl)methyl­idene]-4-methyl­benzohydrazide

In the title compound, C20H18N2O2, the mean planes of the naphthyl system and the benzene ring form a dihedral angle of 88.48 (10)°. In the crystal, N—H⋯O hydrogen bonds link the mol­ecules into C(4) chains, which propagate along the b-axis direction

2-Fluoro-N′-[(2-hydroxynaphthalen-1-yl)methylidene]benzohydrazide

In the title mol­ecule, C18H13FN2O2, the hy­droxy group is involved in an intra­molecular O—H⋯N hydrogen bond. The naphthyl ring system and the benzene ring form a dihedral angle of 31.0 (2)°. In the crystal, N—H⋯O hydrogen bonds link the mol­ecules into chains propagating in [101]

Nanotechnology in Head and Neck Cancer: The Race Is On

Rapid advances in the ability to produce nanoparticles of uniform size, shape, and composition have started a revolution in the sciences. Nano-sized structures herald innovative technology with a wide range of potential therapeutic and diagnostic applications. More than 1000 nanostructures have been reported, many with potential medical applications, such as metallic-, dielectric-, magnetic-, liposomal-, and carbon-based structures. Of these, noble metallic nanoparticles are generating significant interest because of their multifunctional capacity for novel methods of laboratory-based diagnostics, in vivo clinical diagnostic imaging, and therapeutic treatments. This review focuses on recent advances in the applications of nanotechnology in head and neck cancer, with special emphasis on the particularly promising plasmonic gold nanotechnology

Suicide among Arab-Americans

BACKGROUND: Arab-American (AA) populations in the US are exposed to discrimination and acculturative stress-two factors that have been associated with higher suicide risk. However, prior work suggests that socially oriented norms and behaviors, which characterize recent immigrant ethnic groups, may be protective against suicide risk. Here we explored suicide rates and their determinants among AAs in Michigan, the state with the largest proportion of AAs in the US. METHODOLOGY/PRINCIPAL FINDINGS: ICD-9/10 underlying cause of death codes were used to identify suicide deaths from among all deaths in Michigan between 1990 and 2007. Data from the 2000 U.S. Census were collected for population denominators. Age-adjusted suicide rates among AAs and non-ethnic whites were calculated by gender using the direct method of standardization. We also stratified by residence inside or outside of Wayne County (WC), the county with the largest AA population in the state. Suicide rates were 25.10 per 100,000 per year among men and 6.40 per 100,000 per year among women in Michigan from 1990 to 2007. AA men had a 51% lower suicide rate and AA women had a 33% lower rate than non-ethnic white men and women, respectively. The suicide rate among AA men in WC was 29% lower than in all other counties, while the rate among AA women in WC was 20% lower than in all other counties. Among non-ethnic whites, the suicide rate in WC was higher compared to all other counties among both men (12%) and women (16%). CONCLUSIONS/SIGNIFICANCE: Suicide rates were higher among non-ethnic white men and women compared to AA men and women in both contexts. Arab ethnicity may protect against suicide in both sexes, but more so among men. Additionally, ethnic density may protect against suicide among Arab-Americans