187 research outputs found
Synthesis, Characterization, Thermal Analysis and Structural Studies of New Complexes with Tetradentate Ligand
Some new complexes of 4-(5-(1,5-dimethyl-3-oxo-2-phenyl pyrazolidin-4- ylimino)-3,3-dimethyl cyclohexylideneamino) -1,5- dimethyl-2- phenyl -1H- pyrazol -3(2H) –one (L) with Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Pd(II), Re(V) and Pt(IV) were prepared. The ligand and its metal complexes were characterized by phisco- chemical spectroscopic techniques. The spectral data were suggested that the (L) as a neutral tetradentate ligand is coordinated with the metal ions through two nitrogen and two oxygen atoms. These studies revealed Octahedral geometries for all metal complexes, except square planar for Pd(II) complex. Moreover, the thermodynamic activation parameters, such as ?E*, ?H, ?S, ?G and K are calculated from the TGA curves using Coats –Redfern method. Hyper Chem -8 program has been used to predict structural geometries for compounds in gas phase. The heat of formation (?Hf) and bin ding energy (?Eb) at 298 °K for the free ligand and its metal complexes were calculated by PM3 method. The synthesized ligands and their metal complexes were screened for their biological activity against bacterial species, two Gram positive bacteria (Bacillus subtilis and Staphylococcus aureus) and two Gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa)
Biological Evaluation and Theoretical Study of Bi-dentate Ligand for Amoxicillin Derivative with Some Metal Ions
في هذا البحث تم تحضير معقدات قواعد شف للمركب ميثيل 6- (2- (ثنائي فينيل ميثيلين) أمينو) -2- (4-هيدروكسي فينيل) أسيتاميدو) -2،2-ثنائي ميثيل -5-أوكسو -1-ثيا-4-أزاباي سايكلو(3،2،0)هبتانس -3-كاربوكسيلت مع ايونات كوبلت ،نيكل ،نحاس والزنك ثنائية التكافؤ.تم تشخيص المعقدات المحضرة بطرق مختلفة منها طيف الاشعة تحت الحمراء (FT-IR)وطيف الاشعة فوق البنفسجية-المرئية (Uv-vis) ،الحساسية المغناطيسية ،التحليل الذري للعناصر (C.H.N.S) ،الامتصاص الذري والتوصيلية المولارية. الواضح من الدراسة الطيفية ان المعقدات تمتلك تركيب احادي النوية وان الليكاند المحضر متناسق مع الايونات الفلزية بشكل ثنائي السن مع شكل ثماني السطوح باستثناء معقد الكوبلت الثنائي فانة يمتلك شكل رباعي السطوح. استخدام برنامج Hyper Chem-8.0.7لتوقع الشكل الهندسي للمركبات جنبًا إلى جنب مع حرارة التكوين (°ΔH f) ، طاقة الربط (ΔEb) ، عزم ثنائي القطب (µ) ، ترددات FT-IR في الحالة الغازية . تم فحص هذه المركبات ونشاطهاالحيوي كمضادات للجراثيم والفطريات. In this paper, the complexes of Shiff base of Methyl -6-[2-(diphenylmethylene)amino)-2-(4-hydroxyphenyl)acetamido]-2,2-dimethyl-5-oxo-1-thia-4-azabicyclo[3.2.0]heptane-3-carboxylate (L) with Cobalt(II), Nickel(II), Cupper(II) and Zinc(II) have been prepared. The compounds have been characterized by different means such as FT-IR, UV-Vis, magnetic moment, elemental microanalyses (C.H.N), atomic absorption, and molar conductance. It is obvious when looking at the spectral study that the overall complexes obtained as monomeric structure as well as the metals center moieties are two-coordinated with octahedral geometry excepting Co complexes that existed as a tetrahedral geometry. Hyper Chem-8.0.7 program was employed, after calculating the heat of formation (ΔH°f), binding energy (ΔEb), dipole moment( µ ), and FT-IR frequencies are carried out in gas phase, the geometric shape is suggested. The compounds have been also screened for their bioactivity to antibacterial and antifungal.
Synthesis, Spectroscopic Characterization of Cobalt ComplexfromC16H19N3O3S and photodegradation using prepared Nano TiO2catalyst
Coblatcomplex has been prepared by reaction between C16H19N3O3S (L) as ligand and metal salt (II). The prepared complex were characterized by infrared spectra, electromic spectra, magnetic susceptibility, molar conductivity measurement and metal analysis by atomic absorption and (C.H.N) analysis. From these studies tetrahedral geometry structure for the complex was suggested. The photodegredation of complex were study using photoreaction cell and preparednanoTiO2 catalyst in different conditions (concentration, temperatures, pH).The results show that the recation is of a first order with activation energy equal to (6.6512 kJ /mol)
Synthesis, Theoretical Study, and Biological Evaluation of Some Metal Ions with Ligand "Methyl -6-[2-(4-Hydroxyphenyl) -2-((1-Phenylethylidene) Amino) Acetamido] -2,2-Dimethyl-5—Oxo-1-Thia-4-Azabicyclo [3.2.0] Heptane-3-Carboxyylate
قاعدة شيف (ميثيل 6- (2- (4-هيدروكسيفينيل) -2- (1-فينيل إيثيل إدينيامينو) أسيتاميدو) -3، 3-ثنائي ميثيل-7-أوكسو-4-ثيا-1-أزابيسيكلو [3.2.0] هيبتان -2- كاربوكسيلات. تم استخدام أيونات العناصر و(Co (II), Ni (II , Cu (II) , Zn(II) (II) , (Hg (II)] لتحضير المعقدات . تم استخدام بنسبة تحليل المعادن M والتحليل الكيميائي للعناصر (CHNS)، وغيرها من الطرق الفيزيائية والكيميائية القياسية. تم استخدام القابلية المغناطيسية وقياسات الموصلية وFT-IR والأطياف المرئية للأشعة فوق البنفسجية لتحديدها. تم إجراء المعالجة النظرية للمعقدات المحضرة في الطور الغازي باستخدام برنامج (hyperchem-8.07) للميكانيكا الجزيئية والحسابات شبه التجريبية. تم استخدام طريقة (PM3) لتحديد حرارة التكوين (ΔH˚f)، وطاقة الربط (Eb)، والطاقة الكلية (ET) للروابط والمجمعات المعدنية عند 298 K. لاستكشاف المواقع التفاعلية للمركبات، تم حساب القيم الكهروستاتيكية للرابط (L). تم استخدام PM3 لحساب ترددات اهتزازات (ligand (L ومعقداته المعدنية ، والتي تمت مقارنتها بعد ذلك بالبيانات التجريبية. تم فحص النشاط المضاد للبكتيريا (L) ومركباته المعدنية ضد ثلاثة كائنات دقيقة ضارة: Staphylococcus aureus (إيجابي الجرام) ، Echerchia coli (سلبي الجرام) ، و Candida Albicans.Schiff base (methyl 6-(2- (4-hydroxyphenyl) -2- (1-phenyl ethyl ideneamino) acetamido) -3, 3-dimethyl-7-oxo-4-thia-1-azabicyclo[3.2.0] heptane-2-carboxylate)Co(II), Ni(II), Cu (II), Zn (II), and Hg(II)] ions were employed to make certain complexes. Metal analysis M percent, elemental chemical analysis (C.H.N.S), and other standard physico-chemical methods were used. Magnetic susceptibility, conductometric measurements, FT-IR and UV-visible Spectra were used to identified. Theoretical treatment of the generated complexes in the gas phase was performed using the (hyperchem-8.07) program for molecular mechanics and semi-empirical computations. The (PM3) approach was used to determine the heat of formation (ΔH˚f), binding energy (ΔEb), and total energy (ET) for ligands and metal complexes at 298 ᴼK. To explore the reactive sites of the compounds, the electrostatic potential of the ligand (L) was computed. PM3 was used to calculate the vibrational frequencies of the ligand (L) and its metal complexes, which were then compared to experimental data. The antibacterial activity of (L) and its metal complexes against three harmful microorganisms were examined: Staphylococcus aureus (gram positive), Echerchia coli (gram negative), and Candida albicans
Fabrication of PVC Enrofloxacin-Selective Electrodes for Estimating Enrofloxacin in Pure Form and as Preparation Formula:
أوجدت هذه الدراسة تطورا" لخصائص الاستجابة الكهروكيميائية للأقطاب الكهربائية الانتقائية للإينروفلوكساسين باستخدام الراسب والمعتمد على إنتاج الفوسفوتونجستيك ,بعد أستخدام مزيج من البولي فاينيل هيدروكلورايد (PVC) وداي بيوتيل فثاليت أوداي بيوتيل فوسفيت كمواد ملدنة. كانت أغشية المتحسسات الناتجة عبارة عن قطب كهربائي إنروفلوكساسين-فوسفوتونجستيك (متحسس1) ENR-DBPH-PTAوالقطب (متحسس2) .ENR-DOP-PTA الاستجابات الخطية لأقطاب (ENR-DBPH-PTA) و(ENR-DOP-PTA) كانت ضمن المديات التركيزية 2.1×10-6- 10-1 و3.0×10-6- 10-2مول .لتر-1على التوالي, والتي تم ملاحظتها لكلا المتحسسين. الانحدارات كانت 0.24±51.61 و39.40±0.16 ملي فولت/حقبة. ومديات الدالة الحامضية مساوية الى 8.5-2.5و2.0-9.0 التي لوحظت للمتحسسات 1و2 ,على التوالي. أظهرت أجهزة الاستشعار التي تم إنشاؤها معاملات انتقائية هائلة لعقار ENR.كما أظهرت أجهزة الاستشعار المقترحة خصائص علمية مفيدة لتقدير ENR في جرعة الدواء والشكل النقي.This study explored the development and qualities of the response of electrochemical properties of enrofloxacin-selective electrodes using precipitation based on producing phosphotungstic, after utilizing a matrix of polyvinyl chloride (PVC) and dibutyl phthalate or dibutyl phosphate as a plasticizer. The resulting membrane sensors were an enrofloxacin-phosphotungstic electrode (sensors 1) and an ENR-DOP-PTA electrode (sensors 2). Linear responses of (ENR-DBPH-PTA) and (ENR-DOP-PTA) within the concentration ranges of 2.1×10-6-10-1 and 3.0×10-6-10-2 mol. L-1, respectively, for both sensors were observed. Slopes of 51.61±0.24 and 39.40± 0.16 mV/decade and pH ranges equal to 2.5-8.5 and 2.0-9.0 were observed for sensors 1 and 2, respectively. The coefficients of selectivity of the created sensors demonstrated phenomenal selectivity for ENR. The proposed sensors showed useful scientific properties for the assurance of ENR in drug dosage and pure form
Host genetic susceptibility to mycetoma
Mycetoma is one of the badly neglected tropical diseases characterised by subcutaneous painless swelling, multiple sinuses and discharge containing aggregates of the infecting organism known as grains. Risk factors conferring susceptibility to mycetoma include environmental factors, pathogen factors such as virulence and the infecting dose in addition to host factors such as immunological and genetic predisposition. Epidemiological evidence suggests that host genetic factors may regulate susceptibility to mycetoma and other fungal infections but they are likely to be complex genetic traits where multiple genes interact with each other and environmental factors, as well as the pathogen, to cause disease. This paper reviews what is known about genetic predisposition to fungal infections that might be relevant to mycetoma as well as all studies carried out to explore host genetic susceptibility to mycetoma. Most studies were investigating polymorphisms in candidate genes related to the host immune response. A total of 13 genes had allelic variants found to be associated with mycetoma and these genes lie in different pathways and systems such as innate and adaptive immune systems, sex hormones biosynthesis and some genes coding for host enzymes. None of these studies have been replicated. Advances in genomic science and the supporting technology have paved the way for large-scale genome-wide association and next generation sequencing (NGS) studies, underpinning a new strategy to systematically interrogate the genome for variants associated with mycetoma. Dissecting the contribution of host genetic variation to susceptibility to mycetoma will enable the identification of pathways that are potential targets for new treatments for mycetoma and will also enhance the ability to stratify “at-risk” individuals allowing the possibility to develop preventive and personalised clinical care strategies in the future
Systematic review highlights high risk of bias of clinical prediction models for blood transfusion in patients undergoing elective surgery
Background: Blood transfusion can be a lifesaving intervention after perioperative blood loss. Many prediction models have been developed to identify patients most likely to require blood transfusion during elective surgery, but it is unclear whether any are suitable for clinical practice.
Study Design and Setting: We conducted a systematic review, searching MEDLINE, Embase, PubMed, The Cochrane Library, Transfusion Evidence Library, Scopus, and Web of Science databases for studies reporting the development or validation of a blood transfusion prediction model in elective surgery patients between January 1, 2000 and June 30, 2021. We extracted study characteristics, discrimination performance (c-statistics) of final models, and data, which we used to perform risk of bias assessment using the Prediction model risk of bias assessment tool (PROBAST).
Results: We reviewed 66 studies (72 developed and 48 externally validated models). Pooled c-statistics of externally validated models ranged from 0.67 to 0.78. Most developed and validated models were at high risk of bias due to handling of predictors, validation methods, and too small sample sizes.
Conclusion: Most blood transfusion prediction models are at high risk of bias and suffer from poor reporting and methodological quality, which must be addressed before they can be safely used in clinical practice
The Relation between Visceral and Subcutaneous Fat to Bone Mass among Egyptian Children and Adolescents
BACKGROUND: The relation between fat distribution and bone mass is still being debated in children and adolescents.AIM: To verify the influence of both visceral and subcutaneous fat on bone mass among Egyptian children and adolescents.SUBJECTS AND METHODS: The study involved 78 (38 boys and 40 girls) individuals from children (42) and adolescents (36), aged 8-17 years. They were divided into 2 age groups: children group (20 boys and 22 girls) aged 8-12 years and adolescent group (18 boys and 18 girls) aged 13-17 years. Anthropometric measurements, visceral and subcutaneous fat (measured by ultrasound), body composition, BMD and BMC (Measured by DXA), were attempted.RESULTS: Among children, significant positive correlations between visceral fat; in males; and subcutaneous fat; in females; with total BMC, BMD and its Z-score were revealed. After exclusion of age effect, the association between visceral fat in females with total BMD and its Z-score and lumbar BMD-Z-score became significant. For adolescents, no correlation was observed between either visceral or subcutaneous fat with any parameter of bone mass.CONCLUSIONS: Visceral and subcutaneous fat had significant positive association with bone mass in children; males and females respectively. On the contrary such association disappeared during adolescence
Different Tools for the Assessment of Bone Mass among Egyptian Adults
BACKGROUND: Several tools such as, dual X-ray absorptiometry (DXA), quantitative computed tomography (QCT) and self-assessment tool (OST), are being used for diagnosis of osteoporosis.OBJECTIVE: to compare the sensitivity and specify detection rate of bone mineral density (BMD) changes for DXA versus QCT and OST among a sample of Egyptian adults of both sexes.SUBJECTS AND METHODS: This study is a cross sectional one, which included 62 Egyptians, aged 20-65 years. Each individual was assessed for BMD using DXA at femur and spine sites; QCT and OST which take into account body weight and age. Accordingly they were diagnosed as either osteoporotic/osteopenic or normal.RESULTS: The highest prevalence of osteopenia or osteoporosis was diagnosed among menopause women. DXA at femur has diagnosed more cases of osteoporosis (both osteopenic and osteoporotic) as compared to spine DXA or QCT, but OST is out of rang; as it failed to diagnose any case.CONCLUSION: DXA has been found to be more efficacious than QCT scan in the diagnosis of osteoporosis. DXA in femur is better than DXA-spine and QCT. Generally, DXA is the "gold standard" when assessing osteoporosis. Further studies are needed to modify the equation of OST and confirm its efficiency in Egyptians population
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