Microstructure Evolution of Al6061 Alloy Made by Additive Friction Stir Deposition

In this paper, the phase structure, composition distribution, grain morphology, and hardness of Al6061 alloy samples made with additive friction stir deposition (AFS-D) were examined. A nearly symmetrical layer-by-layer structure was observed in the cross section (vertical with respect to the fabrication-tool traversing direction) of the as-deposited Al6061 alloy samples made with a back-and-forth AFS-D strategy. Equiaxed grains were observed in the region underneath the fabrication tool, while elongated grains were seen in the “flash region” along the mass flow direction. No clear grain size variance was discovered along the AFS-D build direction except for the last deposited layer. Grains were significantly refined from the feedstock (~163.5 µm) to as-deposited Al6061 alloy parts (~8.5 µm). The hardness of the as-fabricated Al6061 alloy was lower than those of the feedstock and their heat-treated counterparts, which was ascribed to the decreased precipitate content and enlarged precipitate size.     

Investigation of antioxidant compounds in commercial pomegranate molasses products using matrix-solid phase dispersion extraction coupled with HPLC

Pomegranate is a well known fruit for its unique flavor, taste and health benefits. The medicinal properties of this fruits directly associated with the phenolic content present, with great anti-oxidant potential. The research is intended to develop matrix solid phase dispersion method (MSPD) and HPLC quantification of four major anti-oxidant marker constituents (vitamin C, gallic acid, rutin & ellagic acid) in pomegranate molasses samples. The effects of several important experimental parameters like type of dispersant, sample-dispersant ratio, solvents and its volume, time of extraction were investigated. A C₁₈ column with the specification (5?µm, 250?×?4.0?mm) was used for the separation. A gradient flow of mobile phase was selected after many trials containing 0.1%, v/v solution of orthophosphoric acid and acetonitrile. The flow rate was 1.0?mL/min; and the chromatograms were recorded at 254?nm. The validation parameters, like linearity (r²?=?0.9985, 0.9965, 0.9925 & 0.9986), accuracy (100.3, 99.5, 100.9 & 101.9%), intra-day precision (%RSD?=?1.09, 1.02, 1.26 & 0.97), inter-day precision (%RSD?=?1.32, 0.83, 1.07, & 1.15) LOD (0.07, 4.50, 0.45 & 0.40?µg/mL), LOQ (0.095, 9.50, 0.85 & 9.5?µg/mL) and robustness (% RSD?=?0.92, 0.76, 0.81 & 0.83) respectively for vitamin C, gallic acid, rutin & ellagic acid, were found satisfactory as per ICH guidelines.     

Hibiclens keratitis

Presumed accidental corneal exposure to Hibiclens (chlorhexidine 4% and detergent) in two patients resulted in severe and permanent corneal opacification. We investigated the corneal toxicity of Hibiclens by gross, biomicroscopic, and histopathologic studies of rabbit eyes exposed to Hibiclens for varying time intervals ranging from five to 15 minutes. Severe, irreversible, and progressive corneal damage resulted in all eyes studied.     

Invasive IPMN and MCN: Same Organ, Sifferent Outcomes?

Background

The efficacy of surgery for invasive mucinous neoplasms is unclear. We examined the natural history of invasive mucinous cystic neoplasms (MCN) and invasive intraductal papillary mucinous neoplasms (IPMN) in patients who underwent pancreatic resection.

Methods

The Surveillance, Epidemiology, and End Results (SEER) database (1996–2006) was queried for cases of resected invasive MCN and IPMN. Demographics, tumor characteristics, and overall survival were examined using log-rank analysis and multivariate Cox regression model.

Results

Of 185 MCN cases and 641 IPMN cases, 73% and 48%, respectively, were women (P < 0.0001). Most (73%) IPMN were in the head of the pancreas; most (64%) MCN were in the tail/body (P < 0.0001). Lymph node metastasis was more common for IPMN than MCN (46% vs. 24%, P < 0.0001). Overall survival after resection was better for patients with stage I MCN vs. stage I IPMN (P = 0.0005), and it was better for patients with node-negative MCN vs. node-negative IPMN (P = 0.0061). There was no significant difference in survival of patients with stage IIA MCN vs. stage IIA IPMN (P = 0.5964), stage IIB MCN vs. stage IIB IPMN (P = 0.2262), or node-positive MCN vs. node-positive IPMN (P = 0.2263). Age older than 65 years (hazards ratio (HR) 1.71, P = 0.0046), high tumor grade (HR 2.68, P < 0.0001), higher T stage (HR 2.11, P < 0.0001), and IPMN histology (HR 1.90, P = 0.0040) predicted worse outcome in node-negative patients.

Conclusions

Our findings suggest that survival is better after resection of invasive MCN versus invasive IPMN when disease is localized within the pancreas, but this difference disappears in the presence of nodal metastasis or extrapancreatic extension.     

Treatment of Mammary Duct Fistula by Fistulectomy and Saucerization

This study was designed to assess the efficacy and long-term outcome of fistulectomy and saucerization for treatment of mammary duct fistulae. Mammary fistula is a chronic condition that represents the final step in what has been termed “mammary duct associated inflammatory disease sequence.” The treatment is primarily surgical and may include healing by secondary intention or primary closure with or without antibiotics. Reported series are small and often include variable surgical strategies applied without consistency. A consecutive series of 53 patients who had 59 mammary duct fistulae were treated by fistulectomy with saucerization. The median age was 32 years. Wounds were allowed to heal by secondary intention and antibiotics were not used. We reviewed the case records to establish the incidence of recurrent fistula and the time to complete healing. The long-term cosmetic outcome was determined by a postal survey. After a median follow-up of 6 years there had been no relapse in 92%. There was significant delay in healing in six cases (range: 10 to 30 weeks). Thirty-eight patients (83%) gave a definite history of regularly smoking between 10 and 20 cigarettes a day. Two thirds of the patients were either pleased or satisfied with the final cosmetic result of the surgery, but more than 90% said that it left them with some distortion of the nipple. Fistulectomy and saucerization achieves long-term cure in the majority of patients with mammary duct fistula, but it results in some degree of distortion of the nipple. The strong relationship between smoking and the occurrence of mammary duct fistulae is again demonstrated.     

Surgical management of pancreaticoduodenal artery aneurysms in association with celiac trunk occlusion or stenosis

Aneurysms of the visceral arteries, especially of the pancreaticoduodenal artery, are rare. They show a wide clinical spectrum, ranging from asymptomatic incidental findings to rupture-inducing catastrophic bleedings. Since growth progression and the risk of rupture cannot be foreseen and there is no relation between the size of the aneurysm and propensity to rupture, rupture unfortunately carries a high mortality, >50%. Thus, all aneurysms of the pancreaticoduodenal artery should be treated. The therapy of choice, either operative intervention or catheter embolization, is determined by many factors. Among these are localization, size, relation to other vessels and neighboring organs, the urgency of intervention, and the experience of the therapist. Surgical therapy should be favored in patients with pancreaticoduodenal artery aneurysm due to celiac trunk occlusion. We report here our experience in the surgical treatment of pancreaticoduodenal artery aneurysms in association with celiac trunk occlusion or stenosis over the last 5 years.     

An Exact Model for Predicting Tablet and Blend Content Uniformity Based on the Theory of Fluctuations in Mixtures

Content uniformity (CU) of tablets is a critical property that needs to be well controlled in pharmaceutical products. Methods that predict the CU accurately can greatly help in reducing the development efforts. This article presents a statistical mechanical framework for predicting CU based on first principles at the molecular level. The tablet is modeled as an open system that can be treated as a grand canonical ensemble to calculate fluctuations in the number of granules and thus the CU. Exact analytical solutions to hard sphere mixture systems are applied to derive an expression for the CU and elucidate the different factors that impact CU. The model was tested against literature data and a large set of tablet formulations specifically made and analyzed for CU using a model active pharmaceutical ingredient. The formulations covered the effect of granule size, percentage loading, and tablet weight on the CU. The model is able to predict the mean experimental coefficient of variation (CV) with good success and captures all the elements that impact the CU. The predictions of the model serve as a theoretical lower limit for the mean CV (for infinite batches or tablets) that can be expected during manufacturing assuming the best processing conditions.     

Relationship between HLA-DRB1*0101, DRB1*0301 alleles and interleukin-12 in haemophilic patients and hepatitis C virus positive hepatocellular carcinoma patients

The immune system can effectively eliminate hepatitis C virus (HCV) in 15 % of acute hepatitis cases. It is assumed that certain HLA-DR alleles present HCV epitopes more effectively to CD4 helper T cells than do others resulting in vigorous proliferative response to these epitopes and probably HCV recovery. So, we aimed at investigating the frequency of HLA-DRB1*0101 and DRB1*0301 alleles in child and adult haemophilics and in HCV positive hepatocellular carcinoma (HCC) patients in a trial to predict patients who require early therapeutic intervention. We also evaluated interleukin (IL)-12 levels in these patients since IL-12 induces interferon (IFN)-gamma production. This study was conducted on 50 antiHIV negative male patients subdivided into: 25 HCV negative haemophilics (group I), 10 HCV positive haemophilics (group II) and 15 HCV positive HCC (group III). Fifteen healthy persons of matched age and free of HCV and HIV infections were chosen as controls (group IV). All patients and controls were subjected to thorough history taking and clinical examination, routine and diagnostic investigations, viral markers, DRB1*0101 and DRB1*0301 amplification by polymerase chain reaction and plasma IL-12 quantitation by enzyme linked immunosorbent assay (ELISA). The frequencies of DRB1*0101 and DRB1*0301 were 20% and 30% respectively in HCV positive haemophilics and 13.3% and 40%, respectively in HCC. IL-12 levels were significantly lower in HCC cases than in HCV positive haemophilics. Among the haemophilics, IL-12 levels were non-significantly higher in children than in adults and were associated with the given number of blood product bags. DRB1*0101 and DRB1*0301 may have a role in HCV clearance and persistence in Egyptian patients with haemophilia and HCC. Low IL-12 levels encountered in HCV positive haemophilics suggest its relation to immunopathogenesis and outcome of HCV infection.