Dissimilar micro friction stir welding of ultra-thin Mg AZ31 to Al 6061 sheets

We report the first successful work on micro friction stir welding (μFSW) between ultra-thin (500 μm) Mg AZ31 and Al 6061-T6 alloy sheets. The process resulted in a defect-free fully consolidated butt weld with regions of refined grains and strong metallurgical interlocking. Prepared joints evaluated under tensile testing showed joint efficiency of 54.5% with respect to AZ31 base material. Fracture under tensile testing occurred in stir zone/thermomechanically affected zone interface on Mg advancing side owing to the presence of intermetallic compounds. The prepared joints would have significant potential for structural applications in micro-assemblies and battery packs

Prevalence of vitamin D deficiency in Pakistani females and its link to breast cancer

Female breast cancer remains a major health concern due to its rising incidence and mortality rates around the world. Recent statistical trends have shown a significant increase in its prevalence, accounting for 11.7% of all cancer cases worldwide (1). In Pakistan, female breast cancer incidence is the highest among all other malignancies, with a total of 25,928 cases reported nationally in 2020 (2). There are numerous risk factors for breast cancer: old age, family history of breast and reproductive tract malignancies, early menarche, nulliparity, late menopause, high-fat diet, alcohol consumption etc. (3). A study conducted in 2017 identified vitamin D deficiency (VDD) as a possible risk factor for breast cancer (4).  In 2020, the results of a case-control study conducted in Karachi, Pakistan, revealed that women with low serum VDD &lt;20ng/ml were at a greater risk of developing breast cancer compared to patients with sufficient serum vitamin D &gt;30ng/ml (5). Historically, Pakistani women are prone to developing VDD despite abundant sun light due to Pakistan’s subtropical climate. The primary reason behind this paradox can be associated with the low air quality index in many of the major cities of the country. The high population density and closely-built infrastructure also act as barriers towards adequate sun exposure for Pakistani women. Furthermore, distorted beauty ideals that discourage women from going out in the sun are deeply rooted in South Asian culture. The cosmetics industry plays a huge role in reinforcing this notion through advertisements that glorify fair-skinned women. There is also a lack of awareness regarding balanced diets among women, especially from lower socio-economic backgrounds. The possible correlation of VDD with female breast cancer has amplified the need for awareness programmes to educate the female population regarding the importance of vitamin D. Women-centric NGOs and healthcare organisations spreading awareness regarding breast cancer should emphasize VDD as its underlying cause and encourage them to spend more time outdoors and to include vitamin D supplements in their diet. Electronic media can also play a pivotal role in propagating this information. Lastly, the government’s ongoing food fortification programme against VDD and other nutritional deficiencies should be accelerated and strictly monitored to ensure its proper implementation and success. With female breast cancer increasing at an unprecedented rate, the government must take effective measures to minimize the risk of breast cancer in vitamin D deficient females. Continuous...</jats:p

Friction stir extrusion of ultra-thin wall biodegradable magnesium alloy tubes — Microstructure and corrosion response

Magnesium alloys are increasingly being considered for structural systems across different industrial sectors, including precision components of biomedical devices owing to their high specific strength and stiffness, biodegradability. For example, tubular devices such as coronary stents manufacture require defect-free, highquality tubes with thin walls (100 μm – 1 mm) as a precursor. Here, we have produced fully consolidated, structurally sound ultra-thin walled (~ 400 μm) AZ31 Mg alloy tubes by friction stir back extrusion (FSE) — a relatively new severe deformation process used typically to manufacture thick metallic tubes and rods. The tube cross-sectional microstructure was layered and consisted of a severely deformed stir zone with refined grains near the inner edge, a back-extruded zone with small grains near the outer edge, and a thermomechanically affected zone (TMAZ) with coarse grains develop within the central region. On the other hand, the inner tube surface microstructure had an average grain size of 4.1 ± 1.9 μm and a strong basal texture. In comparison, the outer tube surface microstructure was coarse, with an average grain size of 13.3 ± 6.4 μm with no preferred orientation. The microhardness variation along the tube wall thickness indicated the operation of multiple deformation paths during FSE. Upon exposure to Hank’s balanced salt solution at 37 ◦C, microgalvanic coupling resulting from the gradient through-the-thickness grain size and texture differences between the tube inner and outer surfaces, and residual strain arising from the FSE process, promoted a localized attack that preferentially initiated on the outer tube surface and progressed inwards. Static recovery induced by a short duration heat treatment at low temperature did not alter the microstructure but promoted a more general corrosion attack with a significantly reduced corrosion rate. Our results establish that FSE is a viable single-step process to manufacture ultra-thin Mg alloy tubes suitable for degradable precision tubular applications.Other InformationPublished in: Materials Today CommunicationsLicense: http://creativecommons.org/licenses/by/4.0/See article on publisher's website: https://dx.doi.org/10.1016/j.mtcomm.2021.102129</p

Rising HIV seroconversion rates &amp; associated risks among employees of organization ‘X’: A case control study, Pakistan, 2017

Background and Objectives: In 2004 Pakistan escalated from ‘low-prevalence’ to ‘concentrated’ phase of HIV epidemic. Despite global decline in HIV incidence since 1997, rate of HIV infections in Pakistan is persistently rising since 1990. Available literature focusses on key populations or localized outbreaks limited by short study duration and regional applicability of results. We studied HIV seroconversion trends over a period of 8 years in a geographically diverse population and evaluated associated risk factors.&#x0D; Methods: A desk review of HIV surveillance data from 2010 to 2017 was carried out at Armed Forces Institute of Pathology. A case was defined as any adult employed in organization ‘X’, initially screened for HIV but later seroconverted on ELISA and western blot. Case-control study was conducted on cases diagnosed in 2017. Age and sex matched controls were identified from same population sub-group. Structured telephonic interviews were conducted and statistical analysis done at 5% margin of error.&#x0D; Results: The annual HIV diagnosis rate remained relatively stable till 2015 (&lt; 40 /100,000/yr) after which it rose sharply to 60/100,000/yr in 2016. Upward trend continued in 2017 to reach 125/100,000/yr (&gt;200% increase from baseline). Acquisition of HIV was significantly associated with commercial sex activities (OR=9; 95%CI: 1.25-395).&#x0D; Conclusion: HIV seroconversion rates among employees of organization X have increased significantly in the past two years. Unlike HIV outbreaks previously reported from Pakistan, sexual route seems to be the predominant mode of transmission. Focus is mandated on prevention of sexual transmission of HIV at national level as well for all vulnerable populations.&#x0D; doi: https://doi.org/10.12669/pjms.36.6.1735&#x0D; How to cite this:Mansoor E, Azam N, Niazi SK, Sheikh N, Baig MA, Azim MT, et al. Rising HIV seroconversion rates &amp; associated risks among employees of organization ‘X’: A case control study, Pakistan, 2017. Pak J Med Sci. 2020;36(6):1349-1354.   doi: https://doi.org/10.12669/pjms.36.6.1735&#x0D; This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.</jats:p

Factors Leading to Morbidity and Mortality in Neonates Presenting to Pak Emirates Military Hospital, Rawalpindi

Objective: To determine the frequency and association of different risk factors for morbidity and mortality in neonates.&#x0D; Study Design: Case-control study.&#x0D; Place and Duration of Study: Department of Paediatrics, Pak-Emirates Military Hospital, Rawalpindi, Nov 2021 to Apr 2022.&#x0D; Methodology: A total of 332 patients (166 cases and 166 controls) admitted in the neonatal intensive care setting were includedin our study. Patients who were stillborn or had incomplete records were excluded. All patients were followed up till discharge or death and were documented for various risk factors. &#x0D; Results: The mean age of our study population was 11.52 ± 6.45 days, with 176 (53.0%) males. Risk factors such as low birthweight (2.06 [95% Cl 1.20-3.54]), multiple gestations (2.09 [95% Cl 1.87-2.35]), premature delivery (1.61 [95% Cl 1.01-2.57]),male gender (1.62 [95% Cl 1.05-2.51]) and lack of antenatal care (1.61 [95% Cl 1.01-2.57]) showed an association with mortality.Early-onset neonatal sepsis (1.78 [95% Cl 0.98-3.22]), hypoxic ischaemic encephalopathy (3.01 [95% Cl 1.55-5.82]), meconiumaspiration syndrome (2.42 [95% Cl 0.97-6.05]), congenital anomalies (4.15 [95% Cl 0.87 – 19.85]) and inborn errors of metabolism (7.26 [95% Cl 0.88-59.71]) were all associated with an increase in mortality.&#x0D; Conclusion: Increased risk for mortality in critically ill neonates is multifactorial and requires intervention at multiple levels to reduce mortality at all phases of gestation.&#x0D;  </jats:p