Hydrogen production by photocatalytic water-splitting using nitrogen and metal co-doped TiO2 powder photocatalyst

Nitrogen-doped titanium dioxide (N-TiO2) powders were synthesized by hydrolysis and used as a support for doping with various metals, such as, Fe, Cr, Ni, and Pt. Aqueous solutions of metal salts were used as a metal source and metals were deposited on N-TiO2 powders. Ni-N-TiO2 catalysts with various nickel concentrations were studied in detail. X-ray diffraction and diffuse reflectance spectrophotometry were used for the characterization of the photocatalysts. The Ni-N-TiO2 photocatalysts were then tested in photocatalytic water splitting under visible light. The optimum dopant concentration was found to be 10 mu mol Ni/g N-TiO2 for Ni-N-TiO2. The photocatalyst, Ni-N-TiO2, has shown a stable and high activity, 490 mu mol of H-2 g(cat)(-1) h(-1) for the first 6 h of operation

The Role Of Antifibrinolytic Agents In Gynecologic Cancer Surgery

Objective: To compare the effects of crystalloid and colloid solutions, tranexamic acid and epsilon-aminocaproic acid on the need for allogenic blood transfusion and on coagulation and fibrinolysis parameters. Methods: We conducted the study in the Anesthesiology and Reanimation Department of Hacettepe University Medical Faculty, Ankara, Turkey between March 2004 and April 2005. The study included 105 patients, classified by the American Society of Anesthesiology as physical status groups I-II, undergoing gynecologic cancer treatment. We divided them into 5 groups: group I (crystalloid) received crystalloid solutions, group 11 (colloid) received colloid solutions, group III (tranexamic acid) received 10 mg.kg(-1) tranexamic acid, and group 5 (epsilon-aminocaproic acid) received 100 mg.kg(-1) epsilon-aminocaproic acid. All patients' bleeding amount was measured and recorded perioperatively, and at the 12th and 24th hours postoperatively. We then evaluated the patients' hemoglobin, hematocrit, activated thromboplastin time, international normalized ration, fibrinogen, and thrombocyte count and symptoms of pulmonary embolism. Results: In comparing the amount of bleeding, the bleeding in the tranexamic acid group was 30.8% less than the crystalloid group (p < 0.05), 33.3% less than the colloid group (p < 0.05), and 23.9% less than the epsilon-aminocaproic acid group (p < 0.05). Conclusion: When the negative effects of blood transfusions were considered, tranexamic acid administration can be recommended for decreasing the need for blood transfusion in gynecologic cancer surgery.Wo

Inverted Polymer Solar Cells Using CdS Thin Film Grown by Successive Ionic Layer Adsorption and Reaction Method as Electron Transport Layer

In this work, CdS thin films were coated by Successive Ionic Layer Adsorption and Reaction (SILAR) technique with various immersion cycles and used as electron transport layer (ETL). The effects of number of immersion cycle on the optical, structural and morphological properties of as prepared and annealed CdS films were investigated. The inverted type geometry hybrid solar cells were fabricated by using CdS films as electron transport layer (ETL), blend of P3HT(poly(3-hexyl) thiophene) and PCBM([6,6]-phenylC61 butyric acid methyl ester) as photoactive layer, and PEDOT:PSS:IPA and V2O5 films as hole transport layers (HTL). The power conversion efficiencies of the inverted hybrid solar cells were significantly enhanced by improved morphology, chemical composition of surface, optical properties of ETL and type of HTL

The characteristics of concomitant thyroid nodules cause false-positive ultrasonography results in primary hyperparathyroidism

Background: Concomitant thyroid nodules are the most common reason for false-positive ultrasonography (US) results in primary hyperparathyroidism. The aims of this prospective clinical Study were to evaluate false-positive US results according to the characteristics of concomitant thyroid nodules and to determine which characteristics of thyroid nodules are important

Value of parathyroid hormone assay for preoperative sonographically guided parathyroid aspirates for minimally invasive parathyroidectomy

Purpose. The key to successful parathyroid surgery is accurate preoperative tumor localization. This study investigates the use of ultrasound (US)-guided parathyroid fine needle aspiration (FNA) as a confirmatory diagnostic method in patients with hyperparathyroidism undergoing minimally invasive parathyroidectomy

Feasibility of surgical management in patients with granulomatous mastitis

Granulomatous mastitis (GM) is a rare inflammatory breast disease of unknown etiology. Although it usually presents with sinus formation and abscesses, it may mimic the clinical characteristics of breast cancer. The aim of this study was to identify the clinical, radiologic, and pathologic characteristics of patients with GM and to show the results of surgical treatment in these patients. A chart review was performed for patients that were treated with a diagnosis of GM at the Breast Unit, Department of Surgery, Istanbul Medical Faculty, University of Istanbul, between September 1998 and January 2003. Eighteen patients were eligible for this study. The median age was 41.5 years (range 16-80 years). Seventeen patients were evaluated by both ultrasonography and mammography; whereas one young patient only had ultrasonography. Three patients were further examined with color Doppler ultrasonography and magnetic resonance imaging (MRI). Fourteen patients (78%) presented with a mass as the chief symptom, with a median size of 3.9 cm (range 1-8 cm), whereas four patients presented with fistula in their breasts. None of the radiologic techniques distinguished benign disease from cancer in any of the 14 patients that presented with a mass except one patient with normal mammography findings. Ultrasonography was only helpful to localize the abscess associated with a fistula tract in one patient. Therefore fine-needle aspiration biopsy (FNAB) was performed in six patients, followed by surgical excisional biopsy. The remaining eight patients with a clinical suspicion of malignancy underwent wide surgical excision with frozen section analysis under general anesthesia. All of the FNAB and frozen section evaluations revealed benign findings. All of the 18 patients underwent a wide excisional biopsy and had a definitive histopathologic diagnosis of GM. The median follow-up was 36 months (range 6-60 months). Only one patient had a recurrent disease, which was diagnosed at 12 months. GM is a rare breast disease that mimics cancer in terms of clinical findings. Preoperative radiologic diagnosis might be difficult. Complete surgical excision is the treatment of choice

Use of preoperative parathyroid fine-needle aspiration and parathormone assay in the primary hyperparathyroidism with concomitant thyroid nodules

Background: Although the sensitivity of imaging studies is high in solitary parathyroid adenomas, negative results are inevitable. The aims of this prospective clinical study are to evaluate the impact of the presence of thyroid disease on the sensitivity and positive predictive value (PPV) of ultrasonography (US), sestamibi (MIBI), and parathyroid fine needle aspiration and parathormone assay (PTH-FNA)

Diagnostic value of thyroglobulin measurement in fine-needle aspiration biopsy for detecting metastatic lymph nodes in patients with papillary thyroid carcinoma

We aimed to compare the diagnostic value of fine-needle aspiration cytology (FNAC) and fine-needle aspiration thyroglobulin measurements (FNA-Tg) for detecting cervical lymph node metastases from differentiated thyroid carcinomas