Reaction of 2,5-Disubstituted-1,3,4-oxadiazoles

Some 5-aryl-2-mercapto-1,3,4-oxadiazole (I) reacted with maleic anhydride, maleic acid and p-benzoquinone affording 2-(5-aryl- -1,3,4-oxadiazol-2-ylthio)succinic anhydrides (II), 2-(5-aryl-1,3,4- -oxadiazol-2-ylthio)succinic acids (III) and 2-(2,5 dihydroxyphenylthio)- 5-aryl-l,3,4-oxadiazoles (IV), respectively. Treatment of 2- methylthio-5-phenyl-l,3-oxadiazole (V) with amines gives 2-[(alkyl or aryl)-amino]-5-phenyl-l,3,4-oxadiazoles (VI). Compound VIe condensed with aromatic aldehydes to give 2-(4-cinnamoylanilino)- 5-phenyl-l,3,4-oxadiazoles (VII) which on bromination afforded the dibromo derivative VIlI and on treatment with hydroxylamine afforded 2-[4-(5-aryl-2-isoxazolin-3-yl)anilino]-5-phenyl-1,3,4-oxadiazoles (IX). Reacting VII with hydrazine hydrate gave 2-[4-(5-aryl-2-pyrazolin-3-yl)anilino]-5-phenyl-l,3,4-oxadiazoles (X), while on treatement VII with acetylacetone and ethylacetoacetate afforded 2- [4-(4-acetyl or carbethoxy-5-phenyl-l-cyclohexen -3-one- -1-yl)anilino]-5-phenyl-l,3,4-oxadiazoles (XIIa, b), respectively

First Principles Simulations of Boron Diffusion in Graphite

Boron strongly modifies electronic and diffusion properties of graphite. We report the first ab initio study of boron interaction with the point defects in graphite, which includes structures, thermodynamics, and diffusion. A number of possible diffusion mechanisms of boron in graphite are suggested. We conclude that boron diffuses in graphite by a kick-out mechanism. This mechanism explains the common activation energy, but large magnitude difference, for the rate of boron diffusion parallel and perpendicular to the basal plane. © 2007 The American Physical Society

Investigations on Recycling Methods of Gypsum Plaster Waste (Review)‎

يحتاج الإنسان إلى الحفاظ على البيئة التي يعيش فيها من أجل أن تبقى مناسبة للحياة للأجيال القادمة. حيث تتسبب الصناعات المختلفة التي يشكلها الإنسان في تلوث البيئة من خلال الطمر بالمخلفات التي تنتج عنها وتتسبب في استهلاك مواد أولية جديدة. من هذه الصناعات، صناعة البورك. حيث يتم إنتاج كمية كبيرة من مخلفات البورك من مجالات مختلفة يتم فيها استخدام البورك. لذلك من الضروري العمل على الحد من هذه النفايات عن طريق إعادة استخدامها أو إعادة تدويرها بأقل التكاليف والإجراءات. تهدف هذه الدراسة إلى مراجعة الطرق المستخدمة لتقليل كمية مخلفات البورك ومعرفة أفضلها. يمكن الاستنتاج أن أفضل الطرق لتقليل كمية مخلفات البورك بإعادة تدويرها بأقل التكاليف أو إعادة استخدامها بدون أي إجراءات مضافة.Humans need to keep on the clean environment in order to refine suitable life for the next generators. Where, the different industries formed by human, cause the environmental pollution by landfill with wastes produced from it and cause the consumption of fresh raw materials. One of these industries, is gypsum plaster industry. Where, a large amount of gypsum plaster waste is produced from different fields that use the gypsum plaster. Therefore, it is necessary to work on reduction of these wastes by reusing or recycling them with the least costs and procedures. This study aims to review the ways used to reduce gypsum waste amount and to figure ant the best among them. It can be concluded that the best ways to reduce the gypsum waste amount are by recycling it with the least costs or reusing it without any additional procedures

Some Chemical Aspects of Tetrahydro-1-thiopyran-4-one Derivatives

3,5-Diarylmethylene-2,6-diphenyltetrahydrothiopyran-4-thiones, 2, reacted with two or four moles of bromine to form 3-aryimethylene 5-bromoarylmethylene- 2,6-dipheny1tetrahydrothiopyran- -4-thione, 3, and 3-arylmethylene-5-bromoarylmethylene-2,6-dibromo- 2,6-diphenyltetrahydrothiopyran-4-thione, 5, respectively. Compound 2a reacted with amines giving 2,6-diphenyl-5-iminophenylmethyl- 3-phenylmethylenetetrahydrothiopyran-4-thiones, 6. Diphenydiazomethane and 9-diazofluorene converted 2a into 4-diphenylethylene- 2,6-dipheny1-3,5 diphenylmethylenetetrahydrothiopyran, 7, and 2,6-diphenyl-3,5-diphenylmethylene-4-(9-fluorenylidene) tetrahydrothiopyran, 8, respectively. Compounds 2 with copper-bronze afforded 3,3\u27,5,5\u27-tetraarylmethylene-2,2\u27 ,6,6\u27-tetraphenyl-Lr-thio- 4,4\u27 dipyranylidenes

Neutrophil-surface antigens CD11b and CD64 expression: a potential predictor of early-onset neonatal sepsis

Background: CD11b, an α subunit of the β2 integrin adhesion molecule, and CD64, the high affinity Fcγ receptor I, are specific neutrophil-surface antigens activated in response to systemic inflammation and, hence, they might potentially help identifying neonatal infections. Objective: We sought to evaluate the time course of expression and diagnostic and prognostic utility of CD11b and CD64 in early-onset sepsis in the suspected newborn. Methods: Sixty newborn infants (28-40 weeks gestation) with antenatal risk factors for sepsis were enrolled and subjected to sepsis work-up including complete blood count, quantification of serum C reactive protein (CRP) and flow cytometric analysis of CD11b and CD64 in cord blood (0 h). These tests were repeated at 8, 24 and 48 h postnatally. Neonates were defined, retrospectively, in two groups: sepsis and no infection, on basis of clinical observation over their first five postnatal days and sepsis work-up results. Results: A significant enhancement of neutrophil CD11b and CD64 expression was demonstrated in the sepsis group as compared to the non-infected group. CD11b over-expression had an onset at 0 h. Its mean value approached two-fold mean level of non-infected neonates by 8-24 h, and declined thereafter. CD64 rising onset was detectable at 8 h and its mean percentage reached four-fold mean value of the non-infected group at 24 h. At 24 h, an optimal cut-off value for CD11b expression of 35% (sensitivity 80%, and specificity 100%), and for CD64 expression of 17% (sensitivity 88%, and specificity 90.3%) had the best performance for prediction of sepsis. Combined use of both markers at 24 h yielded 90% sensitivity and 95% specificity for sepsis prediction. Sepsis survivors showed significantly lower mean expression for CD11b and CD64 as compared to those with fatal outcome. At 24 h, a cut-off value of 88% expression for CD11b and 50% expression for CD64 predicted mortality with sensitivity and specificity of 100%. Conclusion: Enhanced expression of neutrophil-surface antigens CD11b and CD64 could be a promising tool for prediction and therapeutic decision-making in early-onset sepsis indicating the necessity of initiation of antimicrobial therapy and reduction of its unnecessary use in non-infected neonates even before definitive microbiologic identification.Keywords: sepsis, neonate, early-onset, neutrophil activation, surface antigen, CD11b, CD64Egypt J Pediatr Allergy Immunol 2004; 2(2): 90-10

Non-invasive index of liver fibrosis induced by alcohol, thioacetamide and schistosomal infection in mice

<p>Abstract</p> <p>Background</p> <p>Non invasive approaches will likely be increasing utilized to assess liver fibrosis. This work provides a new non invasive index to predict liver fibrosis induced in mice.</p> <p>Methods</p> <p>Fibrosis was generated by thioacetamide (TAA), chronic intake of ethanol, or infection with <it>S. mansoni </it>in 240 mice. Both progression and regression of fibrosis (after treatment with silymarin and/or praziquantel) were monitored. The following methods were employed: (i) The METAVIR system was utilized to grade and stage liver inflammation and fibosis; (ii) Determination of hepatic hydroxyproline and collagen; and (iii) Derivation of a new hepatic fibrosis index from the induced changes, and its prospective validation in a group of 70 mice.</p> <p>Results</p> <p>The index is composed of 4 serum variable including total proteins, γ-GT, bilirubin and reduced glutathione (GSH), measured in diseased, treated and normal mice. These parameters were highly correlated with both the histological stage and the grade. They were combined in a logarithmic formula, which non-invasively scores the severity of liver fibrosis through a range (0 to 2), starting with healthy liver (corresponding to stage 0) to advanced fibrosis (corresponding stage 3).Receiver operating characteristic curves (ROC) for the accuracy of the index to predict the histological stages demonstrated that the areas under the curve (AUC) were 0.954, 0.979 and 0.99 for index values corresponding to histological stages 1, 2 and 3, respectively. Also, the index was correlated with stage and grade, (0.947 and 0.859, respectively). The cut off values that cover the range between stages 0-1, 1-2 and 2-3 are 0.4, 1.12 and 1.79, respectively. The results in the validation group confirmed the accuracy of the test. The AUROC was 0.869 and there was good correlation with the stage of fibrosis and grade of inflammation.</p> <p>Conclusion</p> <p>The index fulfils the basic criteria of non-invasive marker of liver fibrosis since it is liver-specific, easy to implement, reliable, and inexpensive. It proved to be accurate in discriminating precirrhotic stages.</p

Implementation of a bowel management program in the treatment of incontinence in children for primary healthcare providers

Objectives: Our surgical team has devised a bowel management program (BMP) as a basic approach for primary healthcare providers with the least use of resources.Background: Soiling in children is a major problem that has a serious impact on the child’s social and psychological life. Causes vary from idiopathic constipation to postoperative or neuropathic causes as meningomyelocele.Participants and methods: Seventy five children suffering from fecal incontinence were assessed and divided into true incontinence and pseudoincontinence groups. The BMP was applied to both categories in the form of proper diet control, enemas, drugs, and bowel habit alteration. The program was fashioned according to the age, type, severity, and response of each case. A fecal incontinence scoring system was used to assess the results.Results: All cases with pseudoincontinence attained 50% or more improvement in incontinence score whereas the true incontinence cases attained excellent results except in post high anorectal malformation repairs and neurologic groups.Conclusion: Most of the cases suffering from constipation with pseudoincontinence can be treated properly by BMPs, whereas the minority suffering from true incontinence need multidisciplinary work to achieve acceptable results.Keywords: anorectal malformations, bowel management program, chronic idiopathic constipation, fecal incontinence, Hirschsprung’s disea

Electron spectroscopy of carbon materials: Experiment and theory

We present a comparative spectroscopic study of carbon as graphite, diamond and C60 using C1s K-edge electron energy-loss spectroscopy (EELS), X-ray emission spectroscopy, and theoretical modelling. The first principles calculations of these spectra are obtained in the local density approximation using a self-consistent Gaussian basis pseudo-potential method. Calculated spectra show excellent agreement with experiment and are able to discriminate not only between various carbon hybridisations but also local variation in environment. Core-hole effects on the calculated spectra are also investigated. For the first time, the EEL spectrum of carbyne is calculated

Sensorless speed control of five-phase PMSM drives with low current distortion

This paper introduces a design for a sensorless control of a five-phase PMSM drive working at low and zero speeds with low current distortion. The rotor position is obtained through tracking the saturation saliency by measuring the dynamic currents responses of the motor due to the IGBTs switching actions. It uses the fundamental PWM waveform obtained using the multi-phase space vector pulse width modulation only. The saliency tracking algorithm used in this paper doesn’t only improve the quality of the estimated position signals but also guarantees a minimum current distortion through reducing the modifications introduced on the PWM waveform. Simulation results are provided to verify the effectiveness of the proposed strategy for saliency tracking and current distortion minimizing of a five-phase PMSM motor drive over a wide speed ranges under different load conditions

Energetics and stability of vacancies in carbon nanotubes

In this work we present ab initio calculations of the formation energies and stability of different types of multi-vacancies in carbon nanotubes. We demonstrate that, as in the case of graphene, the reconstruction of the defects has drastic effects on the energetics of the tubes. In particular, the formation of pentagons eliminates the dangling bonds thus lowering the formation energy. This competition leads to vacancies having an even number of carbon atoms removed to be more stable. Finally the appearance of magic numbers indicating more stable defects can be represented by a model for the formation energies that is based on the number of dangling bonds of the unreconstructed system, the pentagons and the relaxation of the final form of the defect formed after the relaxation