Correlation of Atrial Fibrillation with Left Atrial Volume in Patients with Mitral Stenosis. a Single Centre Study From Pakistan

Background: Rheumatic heart disease has a strong association with mitral valve stenosis. Atrial fibrillation is one of the most common complications of this condition and is a poor prognostic factor. Early detection and prompt management of atrial fibrillation can help to improve the quality of life and increase the life expectancy of the patients. We carried out this study to investigate the significance of left atrial volumetric changes in mitral stenosis and its correlation with atrial fibrillation. Methodology: We audited the data of 60 patients of rheumatic heart disease who had mitral valve stenosis. The patients were randomized into atrial fibrillation (Group A) and normal sinus rhythm (Group B). We conducted this cross-sectional analytical study at Cardiology Department, Mayo Hospital, Lahore, from 1st February 2017 to 31st January 2018. We only included those patients who consented to be a part of this study and fulfilled our predefined inclusion criteria. Left atrial volume was measured by prolate ellipse method and biplane methods on echocardiography. The Data was analyzed on SPSS v20. Results: Sixty patients were included in the study. Among the subjects, thirty-six (60%) were males, and twenty-four (40%) were females. Atrial fibrillation was noted in 43.33% of the patients of mitral valve stenosis. There was a marked difference in the mean volume of the left atrium among the two groups. We observed that the mean area of the mitral valve for Group A patients was larger than that of patients in Group B. Our study showed an inverse correlation between left atrial volume and mitral valve area among Group A patients. Conclusion: Patients of mitral stenosis are at an increased risk of developing atrial fibrillation if the left atrial volume is increasing. All patients with mitral stenosis should have routine echocardiography & measurement of left atrial volumes, so that proper treatment can be started if the left atrial volume is increasing, to prevent atrial fibrillation

Studying the effect of variation in volume fractions of carbon fibres on mechanical and electrical properties of copper based composites

Metal Matrix Composites (MMC) belong to a class of weight efficient structural materials that are becoming popular in engineering applications especially in electronics, aerospace, aircraft, packaging and various other industries. This study focuses on the effect of varying carbon fiber wt. % on the mechanical properties of the Cu-C composite. The carbon fibers were coated with copper by electroless plating in order to increase the wettability of fibers with the copper matrix. Four compositions of copper based composite were developed by varying amount of carbon fibers. The yield strength decreases with increasing fiber size while the ultimate  tensile strength increases with increasing fiber size. Rockwell hardness test showed an increasing trend of hardness for increasing carbon fibers. The conductivity of Cu-C composite decreases by increasing carbon fibers content. Wear rate of Cu-C composite increases when carbon fiberscontent increases in the composite. SEM/EDX analysis revealed the size and distribution of fibers and indicated the fracture phenomenon.Keywords: Copper based Composites, Mechanical, Electrical and Wear Properties, Microstructur

Thermal, electrochemical and mechanical properties of shape memory alloy developed by a conventional processing route

A Cu based shape memory alloy (Cu-Al-Ni) having a composition 83% Cu, 14% Al, 3% Ni, was developed and studied to determine the shape memory effect. Powder of Cu, Al and Ni was melted in a pit furnace at about 15500C, and casted alloy was heat treated at 8500C for a period of 50 minutes followed by water quenching. Microstructure characterization of alloy (Cu-Al-Ni) was carried out to determine the pre-quenched (cast structure) and quenched martensitic structure. The microstructure analysis of developed samples showed needle like structure of quenched martensite after heat treatment. It has a very good resemblance with structure of casted shape memory alloy obtained from the vacuum induction process. The Vickers hardness test was also performed. Quenched microstructure with improved hardness than pre-quenched structure was observed.Keywords: Shape Memory Alloy, Microstructure, Mechanical Propertie

Impact of Nitrogen Regimes and Planting Densities on Stem Physiology, Lignin Biosynthesis and Grain Yield in Relation to Lodging Resistance in Winter Wheat (Triticum aestivum L.)

Higher plant population and nitrogen management is an adopted approach for improving crop productivity from limited land resources. Moreover, higher plant density and nitrogen regimes may increase the risk of stalk lodging, which is a consequence of complex interplant competition of individual organs. Here, we aimed to investigate the dynamic change in morphology, chemical compositions and lignin promoting enzymes of the second basal inter-nodes altering lodging risk controlled by planting density and nitrogen levels. A field trial was conducted at the Mengcheng research station (33°9′44″N, 116°32′56″E), Huaibei plain, Anhui province, China. A randomized complete block design was adopted, in which four plant densities, i.e., 180, 240, 300, and 360 × 104 ha−1 and four N levels, i.e., 0, 180, 240, and 300 kg ha−1 were studied. The two popular wheat varieties AnNong0711 and YanNong19 were cultivated. Results revealed that the culm lodging resistance (CLRI) index of the second basal internodes was positively and significantly correlated with light interception, lignin and cellulose content. The lignin and cellulose contents were significantly and positive correlated to light interception. The increased planting density and nitrogen levels declined the lignin and its related enzymes activities. The variety AnNong0711 showed more resistive response to lodging compared to YanNong19. Overall our study found that increased planting densities and nitrogen regimes resulted in poor physical strength and enzymatic activity which enhanced lodging risk in wheat varieties. The current study demonstrated that stem bending strength of the basal internode was significantly positive correlated to grains per spike. The thousand grain weight and grain yield had a positive and significant relationship with stem bending strength of the basal internode. The results suggested that the variety YanNong19 produces higher grain yield (9298 kg ha−1) at density 240 × 104 plants ha−1, and 180 kg ha−1 nitrogen, while AnNong0711 produced higher grain yield (10178.86 kg ha−1) at density 240 × 104 plants ha−1 and with 240 kg ha−1 nitrogen. Moreover, this combination of nitrogen and planting density enhanced the grain yield with better lodging resistance

Evaluation of the uptake and impact of neonatal vitamin A supplementation delivered through the Lady Health Worker programme on neonatal and infant morbidity and mortality in rural Pakistan: an effectiveness trial

Background: Despite evidence for the benefits of vitamin A supplementation (VAS) among children 6 to 59 months of age, the feasibility of introduction and potential benefit of VAS in the neonatal period in public health programmes is uncertain. Objective: The primary objective was to evaluate the feasibility and effectiveness of early neonatal VAS (single dose of 50 000 international units within 48–72 hours after birth) delivered through the public sector Lady Health Worker (LHW) programme in rural Pakistan and to document its association with a reduction in mortality at 6 months of age. Methods: A community-based, cluster randomised, placebo-controlled trial was undertaken in two districts of rural Pakistan. LHWs dispensed vitamin A/placebo in identical capsules to newborn infants within 48–72 hours of birth. Follow-up visits were undertaken at 1 week of age and every 4 weeks thereafter until 6 months of age. Results: Of a total of 15 433 consecutive pregnancies among eligible women of reproductive age, 13 225 pregnancies were registered, 12 218 live births identified and 11 028 newborn infants reached by LHWs. Of these, 5380 (49%) received neonatal VAS and 5648 (51%) placebo. The LHWs successfully delivered the capsules to 79% of newborns within 72 hours of birth with no significant adverse effects. Although the proportion of days observed with symptoms of fever, diarrhoea or rapid breathing were lower with neonatal VAS, these differences were not statistically significant. Mortality rates in the two groups were comparable at 6 months of age. Conclusions: While our study demonstrated that neonatal VAS was safe and could be feasibly delivered by LHWs in Pakistan as part of their early postnatal visits, the overall lack of benefit on neonatal and 6-month morbidity and mortality in our population suggests the need for further evaluation of this intervention in populations at risk

Exploring the potential of four medicinal plants for antioxidant enzymes activity, proximate and nutritional composition

A study was conducted to evaluate the antioxidant enzymes activity, proximate and nutritional composition of four medicinal plants, which may contribute to folk pharmacological use in the treatment of different diseases. Plant samples were extracted and antioxidant enzymes like superoxide dismutase (SOD), peroxidase (POD), polyphenol oxidase (PPO) and ascorbate peroxide (APX) activity were estimated. Medicinal plants were also analysed for moisture, ash, protein, fibre, carbohydrate, and fats contents. Plant samples were wet digested and mineral composition in terms of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sodium (Na) was determined. The results revealed that antioxidant activity, proximate and nutritional composition differs significantly among tested medicinal plants extract. The leaves of medicinal plants showed more proximate composition (moisture contents, crude protein, fats contents), nutrient accumulation (N, P, K, Ca, Mg and Na), and antioxidant enzymes (POD, PPO, and APX activity). Among medicinal plants, Tribulus terrestris L. showed the highest amount of crude protein, crude fibre, gross energy, and N and Ca contents. Maximum K, Mg, Na contents, POD, PPO and APX activity was observed in Cenchrus ciliaris L. The ash, fats, phosphorus and SOD activity was more in Euphorbia hirta L. While, Cyperus rotundus L. produced maximum carbohydrates concentration among the tested plants. It is concluded that the target medicinal species had emerged as a good source of the antioxidant and nutritive source, which could play an important role in human nutrition. The extracts of these plants parts can be used in the synthesis of mineral and antioxidant-containing drugs and medicines. This study will provide a baseline for the pharmacology industry

A Highly Secured Image Encryption Scheme using Quantum Walk and Chaos

The use of multimedia data sharing has drastically increased in the past few decades due to the revolutionary improvements in communication technologies such as the 4th generation (4G) and 5th generation (5G) etc. Researchers have proposed many image encryption algorithms based on the classical random walk and chaos theory for sharing an image in a secure way. Instead of the classical random walk, this paper proposes the quantum walk to achieve high image security. Classical random walk exhibits randomness due to the stochastic transitions between states, on the other hand, the quantum walk is more random and achieve randomness due to the superposition, and the interference of the wave functions. The proposed image encryption scheme is evaluated using extensive security metrics such as correlation coefficient, entropy, histogram, time complexity, number of pixels change rate and unified average intensity etc. All experimental results validate the proposed scheme, and it is concluded that the proposed scheme is highly secured, lightweight and computationally efficient. In the proposed scheme, the values of the correlation coefficient, entropy, mean square error (MSE), number of pixels change rate (NPCR), unified average change intensity (UACI) and contrast are 0.0069, 7.9970, 40.39, 99.60%, 33.47 and 10.4542 respectively

An overview of the Leucospidae (Hymenoptera, Chalcidoidea) of the Arabian Peninsula with description of a new species

An overview of the family Leucospidae (Hymenoptera, Chalcidoidea) is provided for the leucospid fauna of the Arabian Peninsula. Two genera containing four species are identified based on morphometrics and colour patterns. One species, Leucospis ayezae Usman, Anwar & Ahmad, sp. nov., is described. Leucospis elegans Klug had been previously recorded from Arabia Felix (= Yemen) and is recorded here for the first time from Saudi Arabia. The status of Leucospis aff. namibica from Yemen has been clarified, and this species is placed here in the genus Micrapion Kriechbaumer as M. clavaforme Steffan. An updated key and a map showing the distribution of the family Leucospidae in the Arabian Peninsula is provided. The occurrence and color morphs of all leucospid species that have been recorded so far from the region are briefly discussed