In past decade, electrochemical energy storage gained undivided attention with the increase in electrical energy demand for the usage of new technology such as moveable electronics. Li-ion batteries (LIB) have been the most successful energy storage system with their long-life cycle and efficiency, lower energy density, and notable cost effectiveness with small-scale energy storage. However, with large-scale energy storage and for long duration, work still needs done to make LIB efficient on such a scale as well. Recently Li–air batteries have been suggested as potential energy storage systems that can provide the solution for large- and long-term electrical energy storage. The Li–air battery utilizes the catalyst-based redox reaction, and still, it is not applicable commercially due to low current density, poor life cycle, and energy efficiency. Generally, such problems are associated with the materials used as an electrocatalyst and on the selection of the electrolyte. Herein, we briefly review the current advancements in the field of electrocatalysts for Li–air batteries which hinders their improvement toward commercial applications, and this review also provides an outlook for future Li–air battery systems.

The main aim of this paper is to study the fifth Hankel determinant for the class of functions with bounded turnings. The results are also investigated for 2-fold symmetric and 4-fold symmetric functions.

A griculture is a fundamental part of Pakistan's economy contributing 18.5% to gross domestic product (GDP), providing employment opportunities to almost 38.5% population and providing raw material for different agro based industries (GoP, 2019). It is therefore, considered as a backbone in overall national development, food security and poverty reduction. Majority of the population i.e. 67% belongs to rural areas, and their livelihood directly or indirectly depends on agriculture (Sanaullah and Abstract | The current study assessed the mechanization challenges and scenario prevailing in rural area of district Peshawar of Khyber Pakhtunkhwa province in Pakistan. This study employed a multi stage sampling technique to gather data on the socio-economic features of the farmers and available machinery. A total of 240 rural farmers were randomly selected from two local union councils of provincial government Khyber Pakhtunkhwa Peshawar. The accumulated data were analysed using mean and standard deviation with an acceptance mean value of ≥3.00 and estimating logit model. Socio demographic features revealed that majority (52%) were in middle age group of 41-50 years, 64% were literate, while 68% respondents had farming as their income source and land owners were 64% with small landholding (46%). The study exposed that illiteracy of the respondents (4.10), et al system (3.98), lack of trained machinery operators (4.27), access of roads to the farm (4.45), adequate capital (4.00) and costly inputs (3.80) were some of the challenges plaguing the use of agricultural mechanization in the rural area. It was established that agricultural mechanization has significant role in boosting farm productivity, improving farmers' livelihood, ensuring economic growth, availability of off-seasonal farm produce, increasing income generating opportunities and reduction in time of operation among others. Logistic Regression indicated a highly significant (p<0.01) positive effect of key determinants including; income source (0.008), farm size (0.001), farming experience (0.004), extension visits (0.009), access to credit (0.002) and access to agricultural machines (0.006) on farm mechanization adoption. The study emphasized that government may make agricultural mechanization and farming resources available and reachable to the farmers in order to persuade farmers in using them to maximize production, arrange awareness trainings and subsidize costly agricultural inputs.

Objective: To evaluate clinical presentation and surgical outcome in children with enteric perforation. Methods: A descriptive retrospective study was conducted in Department of Paediatric Surgery at National Institute of Child Health, Karachi from August 2016 and September 2019, in children 12 years of age and under with diagnosis of enteric perforation. Data about age, gender, duration of illness, hemodynamic status and baseline investigation on admission was reviewed. Details about patients operated early and those who required prolong resuscitation and were operated after 24 hours of admission, need for tube laparostomy, operative findings, type of surgical procedure performed and post-operative outcome were reviewed. Data was analyzed using SPSS version 22. Results: Ninety-seven patients, 60(61.85%) males and 37(38.14%) females were managed during the study period with age ranged from 3-12 years (mean 7.82, ± 2.94 years).and duration of symptoms ranged from 7-30 days (mean 15.56, ± 9.39days). High grade fever and abdominal pain were seen in all patients (100%). Pneumoperitoneum was noted in 71(73.19%) cases on X-ray abdomen. Fifty-one (52.57%) children were anemic and required blood transfusion before surgery. Seventy-one (73.19) patients were optimized and operated within 24 hours while 28(28.86%) cases required more resuscitation so tube laparostomy was done initially and operated after 24 hours. Seventy nine (81.44%) cases had single perforation, 14(14.43%) cases had multiple and four had sealed perforation. Primary repair of perforation was done in 37(38.14%) cases, while ileostomy in 65(76.01%) cases. Postoperatively wound infection was seen in 71(73.19%) cases, intra-abdominal collections in 31(31.95%) and burst abdomen in nine (9.27%) cases. Overall mortality was 12.37%. Till date in 47 patients (72.30%) reversal of stoma has been done. Conclusions: Enteric perforation in children presents usually with hemodynamic instability and sepsis due to prolong period of illness. Therefore, regardless of surgical procedure performed it is associated with high morbidity and mortality. doi: https://doi.org/10.12669/pjms.36.5.2270 How to cite this:Azhar M, Zamir N, Shaikh M, Inayat ullah4. Enteric Fever Complicated by Intestinal Perforation in Children: A Persistent Health Problem Requiring Surgical Management. Pak J Med Sci. 2020;36(5):---------. doi: https://doi.org/10.12669/pjms.36.5.2270 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.

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Small, isolated outcrops of metamorphic sole rocks to the RasKoh ophiolite are exposed south‐east of the RasKoh Arc range, western Pakistan. These crop out as thin slices beneath the sheared serpentinites, and consist of amphibolites, epidote‐bearing amphibolites, and muscovite‐rich amphibolites with granoblastic, grano‐nematoblastic, and porphyroblastic textures. Geochemically, amphibolites present two compositional groups. Group‐I amphibolites are alkaline and enriched in light rare‐earth elements (LREE; LaN/YbN = 11.47–11.60) with Sr‐Nd isotopic compositions of (87Sr/86Sr)i = 0.705481–0.706128, (143Nd/144Nd)i = 0.512668–0.512672, and lower values of εNd(t) (+2.24 to +2.32). While, Group‐II amphibolites are tholeiitic with LREE‐depleted signatures (LaN/YbN = 0.88–1.31), (87Sr/86Sr)i = 0.706103–0.706303, (143Nd/144Nd)i = 0.512851–0.512936, and higher values of εNd(t) (+5.81 to +7.47). Primitive mantle‐normalized and other geochemical diagrams indicate that the protoliths for Group‐I amphibolites are oceanic island basalts (OIB). Conversely, Group‐II amphibolites are more akin to subduction‐related arc tholeiites with geochemical signatures, slightly enriched in large‐ion lithophile elements and with negative Nb‐Ta anomalies. The geothermobarometric results estimate that these rocks were metamorphosed at amphibolite facies at 690°C and 6.5 kbar. Alkaline volcanism is well documented from the other Mesozoic ophiolites of Neo‐Tethyan suture zones. We suggest that the OIB accreted to the base of the obducted plate at an early stage, whereas the island arc tholeiites (IAT) basalts metamorphosed and accreted to the base of the RasKoh ophiolite at a later stage. The OIB‐ and IAT‐type magmas as protolith of amphibolites suggest that the RasKoh ophiolite was emplaced in a supra‐subduction zone‐type forearc in Late Cretaceous (ca. 68–64 Ma).

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