Joining of Dissimilar Al and Mg Metal Alloys by Friction Stir Welding.

In engineering applications, such as automobile, marine, aerospace, and railway, lightweight alloys of aluminum (Al) and magnesium (Mg) ensure design fitness for fuel economy, better efficiency, and overall cost reduction. Friction stir welding (FSW) for joining dissimilar materials has been considered better than the conventional fusion welding process because of metallurgical concerns. In this study, dissimilar joints were made between the AA6061 (A), AZ31B (B), and AZ91D (C) combinations based on the varying advancing side (AS) and retreating side (RS). The dissimilar joints prepared by the FSW process were further characterized by tensile testing, impact testing, corrosion testing, fracture, and statistical and cost analysis. The results revealed a maximum tensile strength of 192.39 MPa in AZ91 and AZ31B, maximum yield strength of 134.38 MPa in a combination of AA6061 and AZ91, maximum hardness of 114 Hv in AA6061 and AZ31B, and lowest corrosion rate of 7.03 mV/A in AA6061 and AZ31B. The results of the properties were supported by photomicrographic fracture analysis by scanning electron microscopy (SEM) observations. Further, the performance of dissimilar joints was statistically analyzed and prioritized for preference by similarity to the ideal solution (TOPSIS) method.

Association between Acute Myocardial Infarction and Periodontitis: A Review of the Literature.

BACKGROUND: Cardiovascular disease (CVD), particularly acute myocardial infarction (AMI), is the leading cause of death worldwide. In India, myocardial events are expected to be the fastest growing cause of death between 2005 and 2015. Thus, in order to prevent and manage the onset of the prevailing AMI epidemic, there is a crucial need to explore different dependent and independent risk factors of AMI, as well as its relationship with other systemic diseases and ill health conditions. One such possible relationship could be an association between AMI and periodontal diseases. OBJECTIVES AND METHODOLOGY: The aim of this study was to review the existing literature to assess the strength of association between AMI and periodontitis in the context of Indian, particularly North Indian, populations and to outline key knowledge gaps in this field. FINDINGS: Review of the literature clearly indicates that evidence on the association between periodontitis and AMI in Indian populations, as well as other populations worldwide, is limited. The number of studies done so far is relatively low. Further, inadequate sample size, retrospective data analyses, potential residual confounding factors, inconsistent definitions of exposure and outcome variables, and reported diversity in results, are some of the other key limitations. CONCLUSIONS: Insufficient evidence is available to justify that periodontal interventions can prevent the onset or progression of acute myocardial events. More longitudinal clinical trials and case-control studies with well controlled confounding factors and valid outcome and exposure measures are needed for determining the true association between the conditions.

Restoration of anthropometric, biochemical and histopathological alterations by Lactobacillus casei supplementation in Giardia intestinalis infected renourished BALB/c mice.

The present study describes the in vivo ameliorating effect of Lactobacillus casei supplementation in renourished Giardia intestinalis infected BALB/c mice. It was observed that daily administration of probiotic 7 days prior to Giardia-infection to renourished mice, efficiently reduced the excretion of Giardia cysts and trophozoite counts, along with significant increased fecal lactobacilli counts compared with Giardia-infected mice. It was also observed that oral feeding of probiotic to renourished-Giardia-infected mice abrogated all the anthropometric and biochemical anomalies. Histologically, morphological and cellular alteration of microvillus membrane integrity revealed that probiotic administration further ameliorated the mucosal damage in renourished-probiotic-Giardia-infected mice compared to severe microvillus atrophy, oedematous, vacuolated epithelial cells and ileitis in renourished-Giardia and Giardia-infected mice. Thus, it is suggested that probiotic used as the functional food helps in restoration of anthropometric, biochemical alterations and atrophied gut by enhancing the goblet cells and reducing the giardiasis.

Analysis of radiation exposure in trauma patients at a level I trauma center.

BACKGROUND: Trauma patients are exposed to potentially high levels of low-dose radiation during radiologic studies. OBJECTIVES: To assess the cumulative effective dose (CED) of radiation exposure (RE) in 177 successive patients admitted to a trauma service from January 1 through February 28, 2006. RESULTS: Patients received a total of 1505 radiographs and 400 computed tomography (CT) scans in the study period. The CED was 14.56 mSv (0.97 mSv radiographs, 13.59 mSv CT scans) per patient total length of stay (LOS). CED averaged 8.66 mSv in the first hour and 11.76 mSv in the first 24 h after arrival. The most commonly performed CT scan was brain (n = 147), followed by abdomen and pelvis (n = 80), and cervical spine (n = 69). CT scans of the brain and cervical spine were the most commonly performed combined imaging tests (35%). Twelve percent of patients received no radiographs, and 15% received no CT scans. Six or more CT scans were done in 6% of patients. RE increased with longer LOS (> 6 days vs. 3-5 days vs. 1 day, p < 0.05). "Pan-scans" (a combination of CTs of the brain, cervical spine, chest, abdomen, and pelvis) were done in 13% (n = 23) of patients. There was a higher total RE from CT scans (25.09 mSv ± 19.48 mSv vs. 4.93 mSv ± 14.20 mSv) in patients with injury severity score (ISS) > 9 vs. ≤ 9 ( p < 0.0001). First hour and first 24-h RE rates from radiographs were lower in patients younger than 15 years vs. 15-45 years and older-than-45-year age cohorts (p < 0.05). CONCLUSIONS: In this study, CED was 14.56 mSv per patient. CT scans accounted for 21% of radiologic studies and 93% of CED. There was a higher CED rate in patients with ISS > 9 and longer LOS.

Radiation trends in trauma patients.

Today, computed tomography (CT) and other studies are used more often early in a trauma case than X-rays, exposing patients to more radiation. The long-term effects of radiation exposure (RE) in trauma patients are of great concern. Investigators randomly selected 60 patients (injury severity scores 15-25) each from the years 2000, 2003, and 2006. The cumulative effective dose (CED) was calculated from the RE of all X-rays and CTs performed during the patient's hospital stay. Total CED/patient increased from 15.97 (2000) to 16.67 (2003) to 23.27 mSv (2006); the increase from 2000 to 2006 was significant (P < 0.05). X-rays increased over the 6-year period from 9.6/patient (pt) to 11.4/pt to 15.4/pt. CT scans increased from 2.2/pt (15.19 mSv) to 3.5/pt (21.85 mSv, P < 0.05). The CED in children increased: 12.88 versus 13.17 versus 15.32 mSv/pt (P > 0.05). RE was 19.5 versus 22.0 versus 27.1 mSv in 16 to 45-year-olds compared with 15.5 versus 14.3 versus 27.0 mSv in older adults. Sixteen to 45-year-olds had significantly higher RE than children (P < 0.05). RE in the first hour and first 24 hours increased but not significantly (P > 0.05). CED increased from 2000 to 2006, due primarily from CT scans. Children had no significant CED increase during the same period and had lower RE than 16 to 45-year-old adults.

Lactobacillus casei as a probiotic in malnourished Giardia lamblia-infected mice: a biochemical and histopathological study.

The study describes the in vivo activity of Lactobacillus casei in malnourished Giardia lamblia-infected BALB/c mice. By experimentation, it was found that daily administration of the probiotic 7 days before inoculation with Giardia trophozoites in malnourished mice efficiently reduced both the severity and duration of giardiasis. More specifically, excretion of Giardia cysts and trophozoites counts were reduced, while faecal lactobacilli counts increased significantly in probiotic-fed malnourished mice, compared with control mice. Interestingly, it was also observed that oral feeding of the probiotic to malnourished mice abrogated all the anthropometric and biochemical anomalies. Histologically, morphological and cellular alteration of microvillus membrane integrity revealed that probiotic administration ameliorated the mucosal damage in malnourished, probiotic-inoculated, Giardia-infected mice compared with the severe microvillus atrophy, œdematous and vacuolated epithelial cells, and ileitis in malnourished Giardia-infected mice. The results clearly show the antigiardial effect of the probiotic in vivo by modulating the gut cells to inhibit the colonization and multiplication of Giardia trophozoites, thus reducing the severity and duration of murine giardiasis.

Subintimal angioplasty for advanced lower extremity ischemia due to TASC II C and D lesions of the superficial femoral artery.

OBJECTIVE: Subintimal angioplasty (SA) has evolved into a viable revascularization procedure for complex lower extremity lesions. Although patency rates are lower than those for autogenous bypass, limb salvage rates are comparable. This study reviewed the 8-year experience of SA in a single center. METHODS: Records of patients undergoing SA were reviewed. Clinical presentation and noninvasive exams were used to classify patients. Lesions were categorized by TransAtlantic InterSociety Consensus (TASC) II guidelines. Outcomes included technical success, patency, amputation-free survival, and limb salvage. RESULTS: 120 patients with TASC II C/D lesions underwent SA. Technical success was 91%. Primary patency at 6 and 12 months was 90% and 73%. Secondary patency at 6 and 12 months was 94% and 85%. One-year amputation-free survival was 90%. One-year limb salvage was 98%. CONCLUSIONS: SA for TASC C/D lesions is a safe procedure and may be considered an alternative to bypass, especially in high-risk patients.

MRI appearance of florid cystic endosalpingiosis of the uterus: a case report.

Endosalpingiosis is a non-neoplastic proliferation of ectopic tubal epithelium. It may be found incidentally or the patients may present with chronic pelvic pain. It may resemble a gynecologic malignancy on imaging findings and clinicians and radiologists should be aware of this benign entity to render a correct diagnosis and to avoid over-treatment. We report here the MR imaging appearance of a case of florid cystic endosalpingiosis.

Can intraoperative thrombolytic therapy assist with the management of acute limb ischemia?

Catheter-directed thrombolytic therapy is a well-accepted treatment modality for acute arterial and graft occlusion, but intraoperative use of plasminogen activators as an adjunct to operative thrombectomy or thromboembolectomy is frequently overlooked by vascular surgeons. Evidence exists that intraoperative intraarterial infusion of lytic agents is safe and is accompanied by breakdown of distal thrombus. This article describes the rationale for intraoperative thrombolysis, reviews the evidence supporting its use, and suggests several technical approaches to incorporating lytic therapy intraoperatively.

New anatomic repair of midline abdominal wall incisions extending to suprapubic region.

This article describes a new technique to close infraumbilical midline abdominal wall incisions extending to the suprapubic region. This repair is technically easy to perform, saves time, reduces the risk of bowel and bladder injury and takes into consideration the anatomical landmarks of the peritoneum, the rectus sheath and the arcuate line. Abdominal wall closure with this repair is especially useful in obese patients. Furthermore, with this repair the pelvic cavity is lined with smooth peritoneum, which may reduce postoperative adhesions in the pelvis. Technically easy to perform and saves time Very useful technique for obese patients Reduced risk of bowel and bladder injury Anatomical in nature Potentially minimizes postoperative adhesions.