Modeling for Design Optimization of Piston Crown Geometry Through Structural Strength and Lubrication Performance Correlation Analysis

Piston subsystem is subjected to very complex but dynamic forces. Such forces include combustion gas force, inertial dynamics forces, lubricating action/damping forces, contact friction forces to name a few. Further, piston ring mounted in piston in addition to these forces experiences out ward springing action inside engine mounting due to inherent elasticity. To evaluate the strength of reciprocating piston, the simultaneous effect of all these forces should be considered, while simulating through finite element method. With effect of all these forces, the currently considered piston of Gray Cast Iron, aluminum alloy and Metal-Metric-Composite (Si-C) are given four different crown shapes for optimization of material and crown geometry for better strength. The rings mounted are considered to be coated with Nickasil. The combined numerical simulation for contact and finite element simulation of structural strength and their correlation suggest many important outcomes. Von-Misses stress is maximum in case of type-B Al-alloy crown, while it is minimum in case of type-C SiC metal matrix piston

Effect of black tea consumption on onset of action of benzodiazepines in children: A case–control study

Introduction: Benzodiazepines (lorazepam and diazepam) are the drugs that have calming effects, but caffeine of black tea is a stimulant. Hence, taking black tea along with benzodiazepines might block the calming effects of the latter. In our locality, giving black tea to the children is a regular sociocultural practice by their parents. Objective: To know the effect of black tea consumption on onset of action of benzodiazepines in children. Methods: An observational analytic matched case–control study was done in our department from January 2015 to June 2015 subjected to interview schedule by simple consecutive sampling, and data were analyzed using SPSS version 24 software after proper consent and ethical committee approval. Inclusion criteria of cases were any child taking black tea routinely between 1 and 15 years of age attending our outpatient department or inpatient department requiring intravenous (IV) benzodiazepines medications, and exclusion criteria were critically ill children, having chronic liver or kidney diseases, and children taking anticonvulsants regularly. Children of identical age groups, not taking black tea at all, requiring IV benzodiazepines were taken as controls. Results: An independent t-test showed a significant difference in the onset of action of lorazepam in black tea drinkers (M=5.44 h, standard deviation [SD]=2.43h) and in non-drinkers (M=1.65 h, SD=0.74h); t (99.06)=13.94h, p=0.016 and for diazepam in drinkers (M=1.65 h, SD=0.74h) and in non-drinkers (M=0.93 h, SD=0.37h); t (98.23)=16.58h, p=0.005. Conclusion: Black tea delays the onset of actions of benzodiazepines. Hence, it is advisable not to give black tea to the children, and further studies on this aspect are warranted

Estimation of gingerol content in different brand samples of ginger powder and their anti-oxidant activity: A comparative study

Gingerol is the most abundant constituent of fresh ginger has potent antioxidant activity but it decreases during postharvest storage and processing. The present work efforts have been made to estimate Gingerol content in different brand samples of Ginger powder and their antioxidant activity compared with the sample cultivated through organic farming. Organic farmed sample was collected from the FRI, Dehradun (UK), other samples were taken from the markets of Srinagar Garhwal and Dehradun and was identified from the Dept. of Botany H.N.B. Garhwal University, Srinagar Garhwal (UK). All regents and chemicals were used of analytical and HPLC grade and extraction was carried out by hot solvent extraction method. FRAP method was used for Antioxidant activity. Simple reversed-phase HPLC-UV method, with gradient elution, was used to estimate the gingerol. A typical HPLC-UV chromatogram was obtained which exhibited a clean and smooth baseline with excellent resolution where all the marker peaks could be identified and quantified. The amount of gingerol in the sample S1 is 04.54%, in S2 is 08.01%, in S3 is 06.74%, in S4 is 04.20%, in S5 is 06.74% and in S6 is 08.54%, estimated respectively by HPLC analysis. Among all samples, S6 (ginger cultivated through organic farming) has significant quantity of gingerol in comparison to other market samples.The reducing ability of different samples of ginger extracts was in the range of 368.27 ± 23.43-3107.28 ± 42.31μmol/g dry weight. The FRAP values for the methanolic extracts of rhizomes in all six varieties were significantly lower than those of vitamin C and α-tocopherol, but higher than that of BHT. When we compared all five market samples with ginger cultivated through organic farming had excellent antioxidant activity. The results conclude that ginger which cultivated through organic farming has a significant antioxidant activity and has a positive relationship between antioxidant activities and total phenolic contents. The high antioxidant activity shows the higher level of total phenolic and flavonoids

Analysis of small nucleolar RNAs reveals unique genetic features in malaria parasites

<p>Abstract</p> <p>Background</p> <p>Ribosome biogenesis is an energy consuming and stringently controlled process that involves hundreds of trans-acting factors. Small nucleolar RNAs (snoRNAs), important components of ribosome biogenesis are non-coding guide RNAs involved in rRNA processing, nucleotide modifications like 2'-O-ribose methylation, pseudouridylation and possibly gene regulation. snoRNAs are ubiquitous and are diverse in their genomic organization, mechanism of transcription and process of maturation. In vertebrates, most snoRNAs are present in introns of protein coding genes and are processed by exonucleolytic cleavage, while in plants they are transcribed as polycistronic transcripts.</p> <p>Results</p> <p>This is a comprehensive analysis of malaria parasite snoRNA genes and proteins that have a role in ribosomal biogenesis. Computational and experimental approaches have been used to identify several box C/D snoRNAs from different species of <it>Plasmodium </it>and confirm their expression. Our analyses reveal that the gene for endoribonuclease Rnt1 is absent from <it>Plasmodium falciparum </it>genome, which indicates the existence of alternative pre-rRNA processing pathways. The structural features of box C/D snoRNAs are highly conserved in <it>Plasmodium </it>genus; however, unlike other organisms most parasite snoRNAs are present in single copy. The genomic localization of parasite snoRNAs shows mixed patterns of those observed in plants, yeast and vertebrates. We have localized parasite snoRNAs in untranslated regions (UTR) of mRNAs, and this is an unprecedented and novel genetic feature. Akin to mammalian snoRNAs, those in <it>Plasmodium </it>may also behave as mobile genetic elements.</p> <p>Conclusion</p> <p>This study provides a comprehensive overview on trans-acting genes involved in ribosome biogenesis and also a genetic insight into malaria parasite snoRNA genes.</p

The impact of therapy on the quality of life in asymptomatic patients with freshly detected hypertension

Background: Hypertension is an commonly encountered disease which adversely affect  all aspects of quality of life (QoL). The existing studies are confounded by the presence of multiple comorbidities and inclusion of elderly, which by themselves impairs the QoL. There is thus a need to study the impact of hypertension on QoL, in isolation.Method: This is a single center, prospective, intention to treat, observation study. The aim of the study is to evaluate the change in the QoL over six months, in newly diagnosed asymptomatic patients of hypertension. The tools used to assess the QoL included World Health Organisation’s Quality of Life Questionnaire (WHOQOL- BREF) and Short Form-36 (SF-36).Result: A total of 232 patients (172 males and 60 females) were enrolled in the study. The mean age was 44.66 years. A total of 102 patients (43.97%) had stage-1 and 130 patients (56.03%) had stage-2 hypertension. The female gender is associated with a higher likelihood of presentation with stage-2 hypertension. The male cohort had a better baseline QoL. The desired blood pressures was achieved in 40.52%. With therapy, the QoL improved significantly; sub-hoc analysis showed, the improvement was higher in males and those with stage-1 hypertension. There is an inverse relationship between the QoL and requirement for higher number of antihypertensive mediations.Conclusions: In patients with asymptomatic primary hypertension, treatment improves all aspects of QoL. The factors adversely affecting the QoL include female gender, higher stage of hypertension, poor blood pressure control and requirement of higher numbers of antihypertensive medicine

An FEA material strength modelling of a coated engine piston

Engine pistons are subjected to high gas pressure force on the crown. Such compressive force, helps the piston to gain inertia for reciprocation. But suitable materials are required to sustain higher temperature(500 °C) and pressure (120 bar) environments in engine. Aluminum based alloy or cast iron are selected for such application. To enhance material life, sometimes coating is done to reduce the effect of thermal and stress behavior. This study aims to investigate a combination effect of coating and geometrical modification on the material strength of an engine piston. A piston head, with a bowl shape was analyzed by finite element technique, considering the whole piston is coated with TiSiCN thin layer. The analysis was developed to predict the material strength of two types of pistons: uncoated flat crown and a TiSiCN coated bowl on the crown. A comparative analysis was carried out to summarize the benefits of such modifications in a piston. The result showed a 33.96% reduction on stress level and 11.9% reduction in deformation achieved due to such coating process

Serum ferritin as a diagnostic marker for cardiac iron overload among beta-thalassemia major children

Introduction: Beta-thalassemia major is the most common chronic hemolytic anemia. It is a well-comprehended fact that the toxic effects of iron overload particularly the cardiomyopathy are the major complication that roots from beta-thalassemia major children. Therefore, timely diagnosis is crucial to optimize the long-term gain. Objective: The objective of the study is to find the cutoff level of serum ferritin for early diagnosis of cardiac iron overload. Materials and Methods: This study was an observational analytical cross-sectional diagnostic study which was conducted from November 2016 to October 2018. With due approval of Institutional Ethics Committee and after taking proper informed consent from the parents and/or legal heir, 105 thalassemic children were enrolled in the study by simple consecutive sampling after satisfying the pre-defined inclusion and exclusion criteria. In this study, two-dimensional Doppler echocardiography was used to detect cardiac iron overload. Serum ferritin levels were estimated, and cutoff values were calculated for each of the echocardiographic parameters of cardiac iron overload, i.e. ejection fraction (EF), left ventricular end-diastolic diameter (LVEDD), and left ventricular end-systolic diameter (LVESD) by receiver operating characteristic curve analysis. Sensitivity (Sn), specificity (Sp), positive predictive value, and negative predictive value were calculated with considering p&lt;0.05 as statistically significant. Results: The mean age of the study participants was 9±3 years. Cutoff value of serum ferritin for detecting abnormality in EF was 3286 ng/ml with Sn of 76.1% and Sp of 88.1%. Similarly, for detecting abnormal LVEDD, cutoff value of serum ferritin was 4640 ng/ml with Sn of 70.1% and Sp of 98.6%, and for LVESD, it was 3286 ng/ml with Sn of 90% and Sp of 70.5%. Conclusion: The serum ferritin level can be used as a reliable marker of myocardial iron overload among childhood beta-thalassemia and hence can be used as an important screening tool

Evaluation of iron overload and adequacy of packed red blood cells transfusion in children with thalassemia major

Background: Transfusion therapy in patients with thalassemia major needs to address the common questions such as what should be the optimal hemoglobin (Hb) level for effective transfusion and how do transfusion requirements affect the success of iron chelation therapy. Objective: The objective of the study was to evaluate iron overload and adequacy of packed red blood cells (PRBCs) transfusion in children with thalassemia major along with the correlation of serum ferritin level with transfusional iron load and pre‑transfusion Hb level. Materials and Methods: This single‑center retroprospective observational study was carried out in thalassemia day care center of tertiary care hospital for 1 year over 32 transfusion‑dependent β‑thalassemic patients up to 18 years of age. Data including pre‑transfusion hemoglobin level, number and volume of PRBC transfused, and serum ferritin level for 1 year were analyzed, and annual transfusion iron load was calculated. Correlation of serum ferritin level with transfusional iron load and pre‑transfusion Hb level was determined using Pearson coefficient (r) and p-value. Results: The mean pre‑transfusion hemoglobin level was 6.4±0.23 g%. The average number and volume of PRBCs transfused in a year were 12.5±3.02 and 112 ml/kg, respectively, with the average annual transfusional iron load of 121.3 mg/kg ±28.9 or 0.3 mg/kg/day. A significant positive (r=0.4184, p=0.017) correlation was observed between serum ferritin level and transfusional iron load with the mean serum ferritin level of 1744±604.6 ng/ml. Negative correlation was observed between serum ferritin and pre‑transfusion Hb level (r=−0.2624 and p=0.1537). Conclusion: All patients were undertransfused and this undertransfusion further leads to more accumulation of iron in the body through increased absorption of dietary iron as a result of anemia and ineffective erythropoiesis

Rice production in Chitwan district of Nepal: An analysis from economic and environmental perspectives

Rice (Oryza sativa L.) is the major staple food in the Nepalese context. Chitwan district of Nepal was purposively selected to analyze the rice production from the socio-economic and environmental perspective. A total of 100 rice growing farmers, 50 organic and 50 inorganic were selected as the sample for the purpose of the study using the simple random method of sampling. Primary data were collected through a pre-tested semi-structure interview schedule and key informant interviews; secondary data were collected reviewing related publications. Descriptive statistics, multiple regression and chi-square test were used for data analysis. The multiple regression revealed that the four explanatory variables included in the model: age of the household head, primary occupation of the household head, number of family members involved in agriculture and subsidy in inputs for rice farming were found to have positive and statistically significant effect on rice yield (P&lt;0.01). Moreover, chi-square test revealed that the farming practices that contributes to climate change mitigation such as: minimum tillage practice (P&lt;0.05), crop diversification (P&lt;0.01), green manuring (P&lt;0.01), agro forestry practice (P&lt;0.05), incorporating crop residues (P&lt;0.1), weed management practice (P&lt;0.01) and pest management practice (P&lt;0.01)were found to be well adopted by the organic rice farmers, in contrast, the farming practices of inorganic rice farmers were statistically and significantly different in this respect. Government should make such policy that could grave the attention of the Nepalese people towards organic agriculture; moreover, encouraging them to make it their primary occupation