437 research outputs found

    Electrodeposition of copper on copper single crystal (100) face in presence of chloride ions

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    Observations of copper electrodeposits on to the (100) plane of copper was made from highly purified solutions of copper sulphate containing known concentration of hydrochloric acid from 10−10 to 10−1 m/L. In pure solutions at current densities of 5 and 10 mA/cm.2 layers and pyramids were noticed. In the presence of hydrochloric acid of concentration 10−9 to 10−5 m/L there is a gradual decrease of distance between successive steps. At 10−4 m/L of HCl there was the breaking of layers giving rise to ridge type of growth. With the increase of concentration to 3·5×10−3 m/L pyramids appear again. On increasing the concentration of HCl to 10−2 m/L there was the formation of triangular pyramids of cuprous chloride and on still increasing the concentration, polycrystalline type of deposit was noticed. The transition from layer to ridge, ridge to pyramids and to polycrystalline deposit occurs at all c.d. studied but the critical concentration of HCl needed for the transition depends upon the current density. Communicated by Prof. M. Santappa,f.a.sc

    Growth of Cu2Cl2 and Cu2Br2 on single crystal faces and polycrystalline copper during dissolution in CuSO4 + H2SO4

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    Cu2Cl2 and Cu2Br2 precipitate and crystallise in the form of triangular pyramids and dendrites when Cu is immersed in aerated, acid CuSO4 solution containing HC1 or HBr. The critical concentration of HC1 or HBr for this precipitation depends on the surface of the copper: Poly-crystalline < (110) < (100) < (111). In the deaerated solution there is no precipitation of Cu2Cl or Cu2Br2 even at a high concentration of HC1 or HBr when only preferential etching occurs

    Underwater Breathing Apparatus

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    An independent closed circuit regenerative type of breathing apparatus has been developed for isolating the respiratory tract from the ambient medium for use during breathing by personnel working in underwater or polluted atmosphere. An oxygen reducer is used in the design of this apparatus for catering to the required flows of oxygen for breathing during use of the apparatus and thus avoiding oxygen poisoning. The paper describes some of the salient aspects of the breathing apparatus to be deployed for submariners and other diving personnel of the Indian Navy and its potential usefulness as a life saving equipment

    Drug utilization pattern among geriatrics according to anatomical therapeutic chemical and defined daily dose classification in a tertiary care hospital

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    Background: This study was conducted to determine the drug utilization pattern among geriatric inpatients in general medicine department of the hospital.Methods: An observational, prospective study was conducted for a period of six months (November 2016 to April 2017) among 200 geriatric patients; demographic details, education, occupation, diagnosis and drug details were recorded. The drugs were categorized by anatomical therapeutic classification (ATC) and defined daily dose (DDD) was calculated. The World Health Organization (WHO) prescribing indicators were assessed.Results: The majority of the patients (59%) were in age group of 60-69 years. Cardiovascular diseases were common among geriatrics. Most commonly prescribed drug was Pantoprazole (81.7%). Drugs were assigned with ATC/DDD codes according to the guidelines of WHO. Drugs prescribed by their generic names were 56.64% and 43% of drugs that were included in the National Essential Medicines List.Conclusions: Clinical pharmacist have to collaborate and work together with physicians in selecting and adjusting the dose among geriatric population in order to reduce development of potential adverse drug reactions, serious drug related complications and drug interaction

    Multi component one pot synthesis and characterization of derivatives of 2-amino-7,7- dimethyl-5-oxo-4-phenyl-5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile and study of anti-microbial activity

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    An efficient and convenient procedure has been described for one-pot multi-component synthesisof tetrahydrobenzo[b]pyrans known as 2-amino-7,7-dimethyl-5-oxo-4-phenyl-5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile which can be obtained from the reaction of substituted aromatic aldehydes, dimedone, malonitrile, in the presence of base such as potassium tertiary butoxide and THF in methanol as solvent at RT condition. All the compounds were examined by advanced spectroscopic data (1H NMR, 13C NMR and LCMS) and the structural determination was evaluated by elemental analysis. In addition to this, all the newly synthesized compounds were examined for their antibacterial activities and antifungal activity by disc diffusion method against the organism of Aspergillus niger and Candida ablicans L.               KEY WORDS: Aromatic aldehydes, Dimedone, Malonitrile, Potasium tertiary butoxide, 2-Amino-7,7-dimethyl-5-oxo-4-phenyl-5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile, Anti-microbial activity Bull. Chem. Soc. Ethiop. 2018, 32(1), 133-138DOI: https://dx.doi.org/10.4314/bcse.v32i1.1

    Natural history of endometriosis in pregnancy: ultrasound study of morphology of deep endometriosis and ovarian endometrioma

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    Objective: To assess the morphological appearance of deep endometriosis and ovarian endometrioma in pregnancy using pelvic ultrasound examination. Methods: This was a prospective observational cohort study conducted over 3 years at University College London Hospital, which is a tertiary level referral unit for early pregnancy complications and an accredited endometriosis center. All women who participated provided written consent and were invited for surveillance ultrasound examination at the time of their routine scans in pregnancy. All scans were performed by a single operator to eliminate interobserver variability. The change in size of ovarian endometrioma and nodules was reported as change in their mean diameter. Ovarian endometrioma with irregular thick inner walls, hyperechoic papillary projections and/or high vascularity and hyperechoic nodules with moderate to high vascularity were reported as decidualized. Results: Sixty-five women with a live, normally sited pregnancy and concomitant ultrasound features of deep and/or ovarian endometriosis were included in the study. The median age of the study population was 34 (range, 23–44) years, and the median gestational age at presentation was 7 + 6 (range, 3 + 6 to 18 + 0) weeks. From the cohort, 47/65 (72%) were nulliparous, 48/65 (74%) had a previous diagnosis of endometriosis and 19/65 (29%) conceived via in-vitro fertilization. There were 10/65 (15% (95% CI, 7–24%)) women with ovarian endometrioma alone, 28/65 (43% (95% CI, 31–55%)) with endometriotic nodules alone and the remaining 27/65 (42% (95% CI, 30–54%)) had both. Of the women with ovarian endometrioma who underwent follow-up, 29/34 (85% (95% CI, 73–97%)) experienced cyst regression, 2/34 (6% (95% CI, 0–14%)) experienced cyst growth, and in 3/34 (9% (95% CI, 0.0–18%)) women, cyst size was unchanged. In 10/34 (29% (95% CI, 14–45%)), there was complete resolution of all cysts. Of the women with nodules who underwent follow-up, 43/51 (84% (95% CI, 74–94%)) experienced nodule regression, 2/51 (4% (95% CI, 0–9%)) experienced nodule growth and, in 6/51 (12% (95% CI, 3–21%)) women, nodule size was unchanged. In 4/51 (8% (95% CI, 0–15%)) women, there was complete resolution of all nodules. In 5/37 (14% (95% CI, 3–25%)) women who attended postnatal follow-up, complete resolution of all endometriotic lesions occurred during pregnancy. In 10/34 (29% (95% CI, 14–45%)) women with ovarian endometrioma and 27/51 (53% (95% CI, 39–67%)) women with nodules, a pattern of growth was observed in the first and second trimesters, followed by regression later in pregnancy. Features of decidualization were observed in 17/34 (50% (95% CI, 33–67%)) women with ovarian endometrioma, most commonly in the first trimester, and in 25/51 (49% (95% CI, 35–63%)) women with nodules, most commonly in the second trimester. Conclusions: For the majority of women, despite features of decidualization being common in the first and second trimesters, ovarian endometrioma and deep nodules regress during pregnancy. Morphological changes of endometriosis in pregnancy are difficult to differentiate from characteristics of malignant lesions. Better understanding of the appearance of endometriosis in pregnancy is vital to minimize intervention and help counsel women regarding their condition. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology

    Radiographic imaging of metabolic bone disorders and their relative management

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    Background: Bone is a strong dynamic organ of the endoskeleton playing a vital role in structural integrity envisaging to keep proper shape and maintenance of the body, mineral reservoirs, blood production, coagulation and immunity. Metabolic bone diseases are a heterogeneous group of disorders that interrupt the normal homeostasis of bone formation and resorption. Bone regulates as well as acts as a host for hematopoiesis by providing niche for proliferation and differentiation of hematopoietic cell. Bone is a dynamic tissue but metabolically active as it is being constantly formed (modelling) and reformed (remodelling). Metabolic bone diseases comprise of a broad spectrum of inherited and acquired disorders characterized by abnormalities in calcium metabolism and bone cell physiology- that lead to an altered serum calcium concentration and skeletal failure.Methods: After taking a properly informed written consent and complete history, thorough clinical examination was done and these patients were subjected to radiographic imaging and biochemical analysis.Results: Serum alkaline phosphatase is a good marker in rickets and osteomalacia, ICTP in osteoporosis, pyridinoline, deoxypyridinoline in primary hyperparathyroidism, serum PICP in renal osteodystrophy.Conclusions: In cases of rickets and osteomalacia either decreased or normal values of serum calcium and serum phosphorus were obtained. But the cases pertaining to renal failure with rickets values of serum phosphorous were found to be raised. However, in all cases of rickets and osteomalacia values of serum alkaline phosphatase were also found to be raised

    Demystifying incentives in the consensus computer

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    Cryptocurrencies like Bitcoin and the more recent Ethereum system allow users to specify scripts in transactions and contracts to support applications beyond simple cash transactions. In this work, we analyze the extent to which these systems can enforce the correct semantics of scripts. We show that when a script execution requires nontrivial computation effort, practical attacks exist which either waste miners\u27 computational resources or lead miners to accept incorrect script results. These attacks drive miners to an ill-fated choice, which we call the {\em verifier\u27s dilemma}, whereby rational miners are well-incentivized to accept unvalidated blockchains. We call the framework of computation through a scriptable cryptocurrency a consensus computer and develop a model that captures incentives for verifying computation in it. We propose a resolution to the verifier\u27s dilemma which incentivizes correct execution of certain applications, including outsourced computation, where scripts require minimal time to verify. Finally we discuss two distinct, practical implementations of our consensus computer in real cryptocurrency networks like Ethereum
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