698 research outputs found
Risk factors for atypical mycobacterial disease in patients with smear positive pulmonary TB
AbstractNon Tuberculous Mycobacteria (NTM) can cause severe infection in selected groups of patients and is very difficult to be differentiated from TB infection clinically or radiologically leading to miss diagnosis and wrong treatment in these cases, the Aim of the present study is to study risk factors associated with NTM disease in patients with Acid Fast Bacilli (AFB) smear positive, Subjects and methods: 1402 patients with AFB smear positive were included in the study, only 47 patients from the study group proved to have NTM disease (diagnosis was done according to ATS/IDSA criteria). Results: the mean age of the NTM patients was 61.8±23.2years, NTM was more common in older age groups and more common in white race patients, on using logistic regression analysis NTM disease was more commonly associated with old TB infection (42.6%) and with bed ridden patients on tracheostomy (31.9%). The most common organisms isolated were the MAC complex (55.3%) followed by M. Kansasii (34.04%). Conclusion: NTM disease should be put into consideration in patients with AFB smear positive and suffering from old TB infection or in bed ridden patients who are on tracheostomy, also if smear is positive for AFB and PCR is negative NTM should be suspected
Polyvinylpyrrolidone - Reduced Graphene Oxide - Pd Nanoparticles as an Efficient Nanocomposite for Catalysis Applications in Cross-Coupling Reactions
This paper reported a scientific approach adopting microwave-assisted synthesis as a synthetic route for preparing highly active palladium nanoparticles stabilized by polyvinylpyrrolidone (Pd/PVP) and supported on reduced Graphene oxide (rGO) as a highly active catalyst used for Suzuki, Heck, and Sonogashira cross coupling reactions with remarkable turnover number (6500) and turnover frequency of 78000 h-1. Pd/PVP nanoparticles supported on reduced Graphene oxide nanosheets (Pd-PVP/rGO) showed an outstanding performance through high catalytic activity towards cross coupling reactions. A simple, reproducible, and reliable method was used to prepare this efficient catalyst using microwave irradiation synthetic conditions. The synthesis approach requires simultaneous reduction of palladium and in the presence of Gaphene oxide (GO) nanosheets using ethylene glycol as a solvent and also as a strong reducing agent. The highly active and recyclable catalyst has so many advantages including the use of mild reaction conditions, short reaction times in an environmentally benign solvent system. Moreover, the prepared catalyst could be recycled for up to five times with nearly the same high catalytic activity. Furthermore, the high catalytic activity and recyclability of the prepared catalyst are due to the strong catalyst-support interaction. The defect sites in the reduced Graphene oxide (rGO) act as nucleation centers that enable anchoring of both Pd/PVP nanoparticles and hence, minimize the possibility of agglomeration which leads to a severe decrease in the catalytic activity.
Optimization Of The Catalytic Performance Of Pd/Fe 3 O 4 Nanoparticles Prepared Via Microwave-assisted Synthesis For Pharmaceutical And Catalysis Applications
Microwave assisted synthesis technique was used to prepare palladium supported on iron oxide nanoparticles. The advantage of using microwave irradiation as a synthetic tool is due to its unique features as a one step, simple, versatile, and rapid process. The reactants are added simply at room temperature without using high-temperature injection. Hydrazine hydrate was added by the following ratios (0.1, 0.2, 0.3, 0.4, 0.6, 0.8, 1, 1.6, and 3) ml to the different prepared samples at room temperature in order to investigate its effect on the catalytic performance of the prepared catalysts. The prepared catalyst could be used as an ideal candidate not only for pharmaceutical industry through cross-coupling reactions but also for low temperature oxidation catalysis of carbon monoxide and pharmaceutical applications as well. The experimental results showed that Pd/Fe3O4 catalyst has a remarkable catalytic activity for carbon monoxide oxidation catalysis due to the strong interaction between palladium and iron oxide nanoparticles. This may be due to the small particle size (7-14 nm) and concentration ratio of the Pd nanoparticles dispersed on the surface of magnetite (Fe3O4). Those nanoparticles were characterized by various spectroscopic techniques including; X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Vibrating Sample Magnetometer (VSM) and transmission electron microscopy (TEM)
Computer-aided acute leukemia blast cells segmentation in peripheral blood images
Computer-aided diagnosis system of leukemic cells is vital tool, which can assist domain experts in the diagnosis and evaluation procedure. Accurate blast cells segmentation is the initial stage in building a successful computer-aided diagnosis system. Blast cells segmentation is still an open research topic due to several problems such as variation of blats cells in terms of color, shape and texture, touching and overlapping of cells, inconsistent image quality, etc. Although numerous blast cells segmentation methods have been developed, only few studies attempted to address these problems simultaneously. This paper presents a new image segmentation method to extract acute leukemia blast cells in peripheral blood. The first aim is to segment the leukemic cells by mean of color transformation and mathematical morphology. The method also introduces an approach to split overlapping cells using the marker-controlled watershed algorithm based on a new marker selection scheme. Furthermore, the paper presents a powerful approach to separate the nucleus region and the cytoplasm region based on the seeded region growing algorithm powered by histogram equalization and arithmetic addition to handle the issue of non-homogenous nuclear chromatin pattern. The robustness of the proposed method is tested on two datasets comprise of 1024 peripheral blood images acquired from two different medical centers. The quantitative evaluation reveals that the proposed method obtain a better segmentation performance compared with its counterparts and achieves remarkable segmentation results of approximately 96Â % in blast cell extraction and 94Â % in nucleus/cytoplasm separation
Ankle Brachial Index in Children with Steroid-Resistant Nephrotic Syndrome
Objectives: This study aimed to assess the ankle brachial index (ABI) as a predictor of peripheral arterial diseases (PAD) in children with steroid-resistant nephrotic syndrome (NS). Methods: Twenty children (11 males and 9 females) attending the Pediatric Nephrology Outpatient Clinic of El-Minia University Hospital, Egypt, were enrolled in this study. Their age ranged between 5 and 15 years with a mean of 10.75 ± 3.31 years. They had proteinuria and were dependent on steroid therapy. Twenty healthy age- and sex-matched children served as a control group. All patients and controls underwent a thorough history-taking and clinical examination. All subjects in the study underwent laboratory investigations, including a urine analysis (24-hour test for protein in urine, and levels of serum urea and creatinine, triglycerides, and cholesterol). A renal biopsy was done to diagnose the children’s histopathological type of NS. A Doppler study was done to determine patients’ ABI. Results: ABI was significantly higher in the patient group than in the control group (P <0.0001). There was a negative correlation between ABI and duration of treatment (r value = 0.77 and P <0.001). Conclusion: ABI is simple non-invasive manoeuvre that can reliably assess arterial stiffness as an early predictor of atherosclerosis in nephrotic patients with long duration of both illness and steroid therapy
Fusion PET-CT imaging of neurolymphomatosis
In a patient suffering from peripheral neuropathy due to neurolymphomatosis, fused PET-CT imaging, performed on a novel in-line PET-CT system, showed multiple small nodular lesions extending along the peripheral nerves corresponding to an early relapse of a transformed B-cell non-Hodgkin's lymphom
Is there a correlation between 18F-FDG-PET standardized uptake value, T-classification, histological grading and the anatomic subsites in newly diagnosed squamous cell carcinoma of the head and neck?
18F-Fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET)/CT imaging of squamous cell carcinoma of the head and neck (HNSCC) renders the possibility to study metabolic tumor activity by measuring FDG-uptake expressed as maximum standardized uptake value (SUVmax). A correlation between SUVmax and several factors including T-classification, histological tumor differentiation or different anatomic subsites is of potential interest in HNSCC. The aim of this study was to evaluate how metabolic tumor activity derived from FDG-PET correlates with prognostic clinical and pathological parameters including these factors. 262 patients with HNSCC undergoing PET/CT for initial staging were assessed separately for a potential correlation between SUVmax and T-classification, histological grading, and anatomical subsites of the primary tumor. Nonparametric testing showed a significant correlation between SUVmax and T-classification (P<0.001). On the contrary, no statistically significant correlation was found between SUVmax and histological tumor grading. Furthermore, no statistical significant correlation between the different anatomical subsites and SUVmax were found. There was no significant correlation of SUVmax and tumor grading after adjustment for T-stage and anatomical localization of the tumor, neither. Conclusion: Metabolic tumor activity correlates with T-stage of HNSCC. However, histological tumor grading does not correlate with SUVmax. The role of primary tumor SUVmax as a predictor of outcome or survival remains unclear. Clinicians should therefore exercise caution in attributing any clinical importance to SUVmax obtained from a single PET/CT exa
Studi Tentang Penguat Cascade Dua Tingkat Menggunakan JFET
Cascade amplifier has more than one stages on the circuit configurations. The purpose of cascade amplifier using JFET is to get larger voltage gain also with large input impedance. Except CS-CS cascade amplifier, cascade amplifier using JFET never studied in every literature. This research focuses on the two stage cascade amplifier using JFET for nine circuit configurations, i.e. CS-CS, CS-CD, CS-CG, CD-CS, CD-CD, CD-CG, CG-CS, CG-CD, and CG-CG. From those nine configurations, the interest is to see gain characteristic and to compare one another. This paper uses JFET 2N5457 type with specification IDSS = 5 mA and VGS(off) = -6 V also specified one of DC bias parameter in the active region that is IDQ = 2 mA. The voltage gain is measured by giving voltage input from 50 mV (Vp-p) until 1000 mV (Vp-p) at 1 KHz. There are some recommendations, one of them is that the CS-CS cascade amplifier is amplifier with the largest voltage gain
Microwave-assisted Synthesis Of Palladium Nanoparticles Supported On Copper Oxide In Aqueous Medium As An Efficient Catalyst For Suzuki Cross-coupling Reaction
We report here a reliable green method for the synthesis of palladium nanoparticles supported on copper oxide as a highly active and efficient catalyst for Suzuki cross-coupling reaction. The experimental synthetic approach is based on microwave-assisted chemical reduction of an aqueous mixture of palladium and copper salt simultaneously using hydrazine hydrate as reducing agent. The catalyst was fully characterized using various techniques showing well-dispersed palladium nanoparticles. The catalytic activity and recyclability of the prepared catalyst were experimentally explored in the ligand-free Suzuki cross-coupling reaction with a diverse series of functionalized substrates. The synthesized Pd/CuO catalyst shows many advantages beside its high catalytic efficiency such as the recyclability of up to five times with negligible loss of catalytic activity, short reaction times, use of environmentally benign solvent systems, and mild reaction conditions
Facile Synthesis Of Reduced Graphene Oxide-supported Pd/Cuo Nanoparticles As An Efficient Catalyst For Cross-coupling Reactions
The present communication reports a scientific investigation of a simple and versatile synthetic route for the synthesis of palladium nanoparticles decorated with copper oxide and supported on reduced graphene oxide (rGO). They are used as a highly active catalyst of Suzuki, Heck, and Sonogashira cross coupling reactions with a remarkable turnover number of 7000 and a turnover frequency of 85000 h-1. The Pd-CuO nanoparticles supported on reduced graphene oxide nanosheets (Pd-CuO/rGO) exhibit an outstanding performance through a high catalytic activity towards cross coupling reactions. A simple, reproducible, and reliable method is used to prepare this efficient catalyst using microwave irradiation synthetic conditions. The synthesis approach requires a simultaneous reduction of palladium and copper nitrates in presence of graphene oxide (GO) nanosheets using hydrazine hydrate as a strong reducing agent. The highly active and recyclable catalyst has many advantages including mild reaction conditions and short reaction durations in an environmentally benign solvent system. Moreover, the catalyst prepared can be recycled for up to five times with nearly identical high catalytic activity. Furthermore, the high catalytic activity and the recyclability of the catalyst prepared are due to the strong catalyst-support interaction. The defect sites of the reduced graphene oxide (rGO) act as nucleation centers that enable anchoring of both Pd and CuO nanoparticles and hence, minimize the possibility of agglomeration which leads to a severe decrease of the catalytic activity
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