Effect of doping on the photocatalytic, electronic and mechanical properties of sol‐gel titanium dioxide films

Heterogeneous photocatalysis has been an active research area over the last decade as a promising solution for energy generation and environmental problems which has led to promising applications from air and water purification systems, self‐cleaning and selfsterilizing surfaces to solar cells and hydrogen production from water dissociation reaction. Titanium dioxide (TiO2), an abundant material with a high photocatalytic efficiency and chemical stability, is undoubtedly the most widely studied and used among all photocatalytic materials. Although titanium dioxide has been used in powder form, its immobilized form (film) is necessary from practical application standpoint. However, there are several shortcomings of titanium dioxide films that need to be addressed to realize a wide range of successful applications: lack of visible light activity, poisoning of the catalytic performance by the substrate and the low surface area compared to powder forms. In addition, mechanical properties of such films have not been investigated thoroughly, which may be critical when abrasion and weathering resistance are necessary. To address each of these issues, a systematic experimental and theoretical investigation of doping titanium dioxide films with a variety of elementswere conducted. Utilizing theoretical calculations to filter elements for experimental studies as well as interpretation of the experimental results, several dopant or dopant combinations were found to remedy some of the issues of photocatalytic titanium dioxide films.Doping with 32 metals, nitrogen and 11 metal‐nitrogen combinations are investigated theoretically and the results are used as guideline for the experimental studies.Particular attention is given to certain metal dopants such as Cr, V, Mo, Ta and Ga not just because of their relatively modest cost but also their non‐toxicity and wide availability of their compatible compounds for sol‐gel synthesis. While metal‐dopants improved the overall efficiency and mechanical properties of titanium dioxide films, visible light activity is only achieved with nitrogen and metal‐nitrogen doping where some of the metal co‐dopants significantly improved the overall photocatalytic efficiency compared to nitrogen‐only doped films.In addition, majority of the experimental studies is accompanied by nanoindentation technique to study the effect of doping and calcination on the key mechanicalproperties of titanium dioxide films. It is shown that good mechanical properties – good photocatalytic activity combinations can be achieved by a choice of appropriate dopant –dopant combinations and coupled with appropriate calcination parameters.Results of the theoretical and experimental investigations led to the development of first commercial photocatalytic tableware glass items which can be utilized under indoor lighting conditions by carefully selecting metal‐nitrogen couples for doping of titanium dioxide films.Ph.D., Materials Science and Engineering -- Drexel University, 201

An assessment of Turkish Defense Industry and Turkey's efforts to transfer military technology: strategies for arming the future

The end of the cold war has created a safer environment for most nations and reduced the need for fielding huge armed forces and vast investments for defense. However, due to her very special strategic position and historical responsibilities, Turkey still faces a range of substantial threats to its national interests, physical security, economic well being. These threats require the maintenance of a broad set of military capabilities in order to deter, and if necessary, to fight and win any future conflict. This thesis investigates the Turkish Defense Industry and Turkey's efforts to transfer military technology to establish a required technological base for a self- sufficient defense industry, which can fulfill the needs of the Turkish Armed Forces and stay competitive in a rapidly changing market place. The goal of this project is to evaluate the present Turkish Defense Industry and to present strategies that should be carefully considered in developing a sound defense industry and technological base policy.http://archive.org/details/anssessmentoftur109451100

An infant with urticaria pigmentosa and rickets

alper, murat/0000-0001-7069-0623; Kurtoglu, Selim/0000-0002-5256-0128WOS: 000175280600013PubMed: 12027094

Serum magnesium concentrations in type 1 diabetic patients: Relation to early atherosclerosis

Hypomagnesemia and sub-clinical atherosclerosis are common in type 1 diabetic patients, and are especially common in poorly controlled and chronically treated diabetics. The aim of this study was to evaluate the relationships between serum magnesium (Mg) and intima-media thickness (IMT), and functions, of common carotid artery (CCA), accepted as markers of early carotid atherosclerosis in type I diabetic patients. Serum magnesium levels were measured in 51 diabetic patients (26 girls and 25 boys). Age, duration of diabetes as well as major cardiovascular risk factors, including anthropometric and metabolic parameters were matched between girls and boys. CCA structure and functions were measured by ultrasonography as IMT, cross-sectional compliance (CSC), cross-sectional distensibility (CSD), diastolic wall stress (DWS), and incremental elastic modulus (IEM). The difference for serum Mg was significant between diabetic girls and boys (0.75 +/- 0.09 mmol/l versus 0.86 +/- 0.14 mmol/l; p = 0.02). Mg levels were correlated with IMT (r = -0.58, p = 0.004) and DWS (r = -0.49, p = 0.01) in girls and with IMT (r = -0.55, p = 0.007) and DWS (r = -0.46, p = 0.03) in boys. In a multivariate regression model, Mg, systolic blood pressure and waist-hip ratio emerged as independent correlates for mean IMT in girls with the total variance explained being 63%, and Mg and triglycerides emerged as independent correlates for mean IMT in boys with the total variance explained being 68%. Mg did not emerge as independent correlates for mean DWS in both girls and boys. Serum magnesium levels in children and adolescent patients with type I diabetes are associated with early atherosclerosis. (c) 2005 Elsevier Ireland Ltd. All rights reserved

Effectiveness of pentoxifylline on the cross-sectional area of intima media thickness and functions of the common carotid artery in adolescents with type 1 diabetes

Objective: The aim of the present study was to evaluate the effect of oral pentoxifylline on the cross-sectional area of intima media thickness (CSA-IMT) and functions of the common carotid artery, a marker of early atherosclerosis, in adolescents with type 1 diabetes

Arterial wall thickening and stiffening in children and adolescents with type 1 diabetes

Objective: We evaluated structural and functional characteristics of the common carotid artery (CCA), a marker of early carotid atherosclerosis, and investigated their relation to metabolic and anthropometric parameters in children and adolescents with type 1 diabetes

Pentoxifylline treatment for protecting diabetic retinopaty in children with type 1 diabetes

Objective: The purpose of this study was to determine whether oral pentoxifylline (PTX) would improve retinal microvascular hemodynamics in children with type 1 diabetes mellitus (DM)

Serious lower extremity venous injury management with ligation: Prospective overview of 63 patients

Management of lower extremity venous trauma using repair or ligation has been an area of controversy during the past decades. However, in unstable patients or if primary repair is technically impossible as a result of extensive disruption of the vein, ligation is recommended. This study investigated the effects of venous ligation on major veins in the lower extremities when primary repair is impossible as a result of extensive laceration of the vein. Between January 2001 and April 2004, 63 patients with Grade III and IV venous injuries were observed prospectively. Compression ultrasonography was performed postoperatively on the fifth day, once before discharge, and at the 3-month visit to assess deep vein thrombosis (DVT) and the patency of arterial repair. If DVT was present, the patient was given an oral anticoagulant (warfarin Na) for 3 months (international normalized ratio, 2.0-3.0), and Class II compression stockings (Sigvaris-212, Ganzoni, Switzerland) were used for 1 year. Follow-up visits occurred at 1, 3, 6, and 12 months and at 6-month intervals thereafter. Combined arterial and venous injuries were present in 50 (79.4%) patients and pure venous injuries were present in 13 (20.6%) patients. DVT developed in 49 patients (77.7%; postoperative n = 37 [58.7%], late n = 12 [19%]). Three arterial restenoses (4.7%) and one pseudoaneurysm (1.6%) of the superficial femoral artery developed. Five early (prophylactic) and two late (compartment syndrome) fasciotomies were performed. Postoperative edema was seen in 56 (88.8%) patients and wound infection was seen in 19 patients (30.1%; n = 18 superficial, n = 1 deep). Two amputations (3.2%) were performed. One patient (1.7%) died as a result of irreversible shock. After a median of 18 months, 25 patients were classified with Clinical Etiology, Anatomy, Pathology classification: 10 legs C-0, seven legs C-2, and eight legs C-3. No severe postthrombophlebitic syndrome was observed. Early leg swelling after venous ligation was the most common morbidity. We observed no significant sequelae of chronic venous insufficiency, and venous ligation had no detrimental effect on associated arterial repair. In cases of DVT, anticoagulation with low-molecular-weight heparin and oral anticoagulants should begin immediately and continue for 3 months along with compression stocking support for 1 year

Choroba pnia lewej tętnicy wieńcowej: poprawa wczesnych wyników leczenia po pomostowaniu tętnic wieńcowych bez użycia krążenia pozaustrojowego u pacjentów z grupy wysokiego ryzyka

Background: Left main coronary artery (LMCA) stenosis is a risk factor in coronary artery bypass grafting (CABG). Although improved outcomes of off-pump CABG have been well documented, LMCA stenosis is often perceived as a contraindicationfor off-pump CABG. In this study, we compared on-pump and off-pump techniques in high-risk patients with LMCA disease.Aim: Documentation of safety and feasibility of off-pump CABG in patients with LMCA disease.Methods: One hundred ninty nine patients with LMCA disease and a EuroScore ≥ 5 were operated upon between 2007 and 2010. One hundred patients (Group I) were operated upon using off-pump techniques, while 99 (Group II) were operated upon using conventional on-pump techniques. Perioperative variables and outcomes at first six months were compared.Results: Despite higher mean age and EuroScore (70.9 ± 4.8 vs. 65.6 ± 7.9, p < 0.001, and 6.09 ± 0.8 vs. 5.31 ± 0.68,p < 0.001, respectively), and lower ejection fraction (41.4 ± 7.3 vs. 49.0 ± 6.2, p < 0.001), hospital mortality (1% vs. 6.1%,p = 0.065), postoperative inotropic support (9% vs. 48.4%, p < 0.001), blood loss (680.6 ± 265.0 vs. 847.2 ± 382, p < 0.001) and transfusions of blood (0.57 ± 0.79 U vs. 1.49 ± 0.82 U, p < 0.001), and hospital stay (6.57 ± 2.04 vs. 7.68 ± 3.44,p = 0.006) were lower in Group I. In both groups, mean number of distal anastomoses and completeness of revascularisation were similar.Conclusions: Using the off-pump technique is safe and improves postoperative early outcomes in high-risk patients with LMCA disease.Wstęp: Zwężenie pnia lewej tętnicy wieńcowej (LMCA) jest czynnikiem ryzyka w przypadku pomostowania tętnic wieńcowych (CABG). Mimo że istnieje wiele danych potwierdzających, iż zabiegi CABG bez użycia krążenia pozaustrojowego (off-pomp CABG) wiążą się z lepszymi wynikami leczenia, zwężenie LMCA jest często uważane za przeciwwskazanie do wykonaniatego zabiegu. W niniejszym badaniu porównano CABG z zastosowaniem krążenia pozaustrojowego i bez użycia krążenia pozaustrojowego u pacjentów z chorobą LMCA.Cel: Celem badania było udowodnienie, że zabieg CABG bez krążenia pozaustrojowego jest bezpieczny i możliwy do wykonaniau pacjentów z chorobą LMCA.Metody: Do badania włączono 199 osób z chorobą LMCA z punktacją EuroScore ≥ 5, operowanych w latach 2007–2010. U 100 pacjentów (grupa I) przeprowadzono zabieg bez użycia krążenia pozaustrojowego, natomiast u 99 (grupa II) zastosowano konwencjonalną metodę z krążeniem pozaustrojowym. Porównano zmienne okołooperacyjne i wyniki leczenia w ciągu 6 miesięcy po zabiegu.Wyniki: Mimo wyższych średnich wieku i punktacji EuroScore (odpowiednio 70,9 ± 4,8 vs. 65,6 ± 7,9;p < 0,001 i 6,09 ± 0,8 vs. 5,31 ± 0,68; p < 0,001) oraz mniejszej frakcji wyrzutowej (41,4 ± 7,3 vs. 49,0 ± 6,2; p < 0,001) w grupie I śmiertelność wewnątrzszpitalna (1% vs. 6,1%; p = 0,065), odsetek pacjentów wymagających podawania leków inotropowych (9% vs. 48,4%; p < 0,001), utrata krwi (680,6 ± 265,0 vs. 847,2 ± 382; p < 0,001) i ilość przetoczonej krwi (0,57 ± 0,79 j. vs. 1,49 ± 0,82 j.; p < 0,001) były mniejsze, a czas pobytu w szpitalu krótszy (6,57 ± 2,04 vs. 7,68 ± 3,44;p = 0,006). W obu grupach średnia liczba zespoleń dystalnych i odsetek całkowitych rewaskularyzacji były podobne.Wnioski: Stosowanie metody off-pump (bez użycia krążenia pozaustrojowego) jest bezpieczne i wiąże się z poprawą wyników leczenia we wczesnym okresie pooperacyjnym u pacjentów z grupy wysokiego ryzyka z chorobą LMCA