Gamma Radiation Induced Effects in TeO2 Thin Films

Gamma radiation induced effects on electrical and optical properties of thin films of tellurium dioxide (TeO2), a wide band gap semiconductor material, of different thicknesses prepared by thermal evaporation method have been studied in detail. The current-voltage characteristics for the thin films before and after gamma irradiation were analysed to obtain normalised current versus gamma dose plots at different applied voltages. The plots obtained clearly show that the normalised current increases almost linearly with the radiation dose up to certain limit and this limit is found to be dependent on thickness of the thin film. Beyond this limit the current is found to decrease. For gamma sources emitting higher gamma energy, this linear behaviour extends to higher radiation doses. The optical characterization of the as-deposited thin films as well as gamma irradiated thin films clearly shows that the optical band gap decreases with increase in the gamma radiation dose up to a certain limit. However, the optical band gap has been found to increase beyond this limit. The observed changes in electrical and optical properties clearly indicate the possibility of using TeO2 thin film as a gamma radiation dosimeter. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3101

Risk adjustment is crucial in comparing outcomes of various surgical modalities in patients with ileal perforation

<p>Abstract</p> <p>Background</p> <p>Using crude mortality and morbidity rates for comparing outcomes can be misleading. The aim of the present study was to compare the outcome of various surgical modalities without and with risk adjustment using Physiologic and Operative Severity Scoring for the enUmeration of Mortality and morbidity (POSSUM) score in cases of ileal perforations.</p> <p>Methods</p> <p>Prospective study on 125 patients of ileal perforations. Resection anastamosis (Group I) was done in 38 patients, primary repair (Group II) in 42 patients and 45 patients had an ileostomy (Group III). The disease severity was assessed in all patients using POSSUM score. The odds of death without and with risk adjustment using POSSUM mortality score were calculated for all groups</p> <p>Results</p> <p>Seventeen patients (14%) patients died and 99 (79%) developed postoperative complications. Using crude mortality rates Group I appeared to be the best treatment option with only 2 (5%) deaths followed by Group II with 5 (12%) deaths where as Group III had the worst outcome with 10 deaths (22%). However, Group III (ileostomy) patients had higher mean POSSUM mortality and morbidity score (55.55%, 91.33%) than Group I (28%, 75.26%) and Group II (27%, 73.59%). Taking Group I as the reference (odds ratio, OR1) odds of death were greatest in Group III (OR 5.14, p = 0.043) followed by Group II (OR 2.43, p = 0.306). With risk adjustment using POSSUM mortality score the odds of death decreased in Group III (OR 1.16 p = 0.875). For the whole group, there was a significant association between the POSSUM score and postoperative complications and deaths. Mean POSSUM mortality and morbidity score of those who died (63.40 vs.33.68, p = 0.001) and developed complications (66.32 vs.84.20, p = 0.001) was significantly higher. For every percent increase in severity score the risk of postoperative complications and death increased by 1.10 (p = 0.001) and1.06 (p = 0.001) respectively.</p> <p>Conclusion</p> <p>Despite ileostomy patients having highest crude mortality and complication rates, after risk adjustment it was equally safe. Severity of the disease rather than the surgical option had a significant impact on the outcome in patients with ileal perforations.</p

Antibiotics sensitivity status and antibiogram patterns of aerobic bacterial isolates from surgical site infections

Background: Surgical Site Infections (SSIs) are the third most common nosocomial infections. Emergence and spread of drug resistant strains have been found to pose a serious challenge in the management of such infections. There is limited information on the epidemiology of such pathogens. The antibiotic sensitivity patterns of aerobic bacterial isolates from post-operative SSIs show wide variations that lead to difficulties in empirical selection of the right kind of drug for treatment. Properly planned studies about antibiotic sensitivities patterns of such isolates can help in judicious management of SSIs and cause reduction in morbidity and mortality.Methods: A total of 50 patients diagnosed by the surgeon and fulfilling the case definition of SSI, were studied for bacteriological analysis. All the clinical specimens were cultured and identified applying standard culture techniques. The aerobic bacterial isolates were subjected to antimicrobial susceptibility testing by Kirby Bauer Disc Diffusion method to arrive at the drug sensitivity patterns. Data were entered in MS Excel spread sheet and analysed using SSPP software version 21.00Results: A total of 32 patterns of sensitivity were observed. For Esch. coli, a total of nine patterns were observed. All strains of Esch. coli were found sensitive to tigecycline (100%) and colistin (100%). For Klebsiella spp. a total of 9 patterns were obtained with TIG-COL being the predominant pattern in 6 cases. For Acinetobacter spp. only colistin was found most effective drug. In case of Pseudomonas aeruginosa, except colistin (100% sensitivity), there were wide variations in sensitivity with imipenem (71%) as next most effective drug. In Proteus spp. - most of the in-use drugs were effective except cephalosporins. Among gram positive organisms, only three strains of Staphylococcus aureus were isolated, and these were MRSA (100%). Two strains of enterococcus were isolated, and these showed sensitivity to linezolid only.Conclusions: Wide variations in sensitivity status observed in the study are suggestive that antibiotic usage should be tailored to individual needs and proper selection of antibiotics for management of SSIs must be guided by laboratory antibiogram

Contribution of germline BRCA1 and BRCA2 sequence alterations to breast cancer in Northern India

BACKGROUND: A large number of distinct mutations in the BRCA1 and BRCA2 genes have been reported worldwide, but little is known regarding the role of these inherited susceptibility genes in breast cancer risk among Indian women. We investigated the distribution and the nature of BRCA1 and BRCA2 germline mutations and polymorphisms in a cohort of 204 Indian breast cancer patients and 140 age-matched controls. METHOD: Cases were selected with regard to early onset disease (≤40 years) and family history of breast and ovarian cancer. Two hundred four breast cancer cases along with 140 age-matched controls were analyzed for mutations. All coding regions and exon-intron boundaries of the BRCA1 and BRCA2 genes were screened by heteroduplex analysis followed by direct sequencing of detected variants. RESULTS: In total, 18 genetic alterations were identified. Three deleterious frame-shift mutations (185delAG in exon 2; 4184del4 and 3596del4 in exon 11) were identified in BRCA1, along with one missense mutation (K1667R), one 5'UTR alteration (22C>G), three intronic variants (IVS10-12delG, IVS13+2T>C, IVS7+38T>C) and one silent substitution (5154C>T). Similarly three pathogenic protein-truncating mutations (6376insAA in exon 11, 8576insC in exon19, and 9999delA in exon 27) along with one missense mutation (A2951T), four intronic alterations (IVS2+90T>A, IVS7+75A>T, IVS8+56C>T, IVS25+58insG) and one silent substitution (1593A>G) were identified in BRCA2. Four previously reported polymorphisms (K1183R, S1613G, and M1652I in BRCA1, and 7470A>G in BRCA2) were detected in both controls and breast cancer patients. Rare BRCA1/2 sequence alterations were observed in 15 out of 105 (14.2%) early-onset cases without family history and 11.7% (4/34) breast cancer cases with family history. Of these, six were pathogenic protein truncating mutations. In addition, several variants of uncertain clinical significance were identified. Among these are two missense variants, one alteration of a consensus splice donor sequence, and a variant that potentially disrupts translational initiation. CONCLUSION: BRCA1 and BRCA2 mutations appear to account for a lower proportion of breast cancer patients at increased risk of harboring such mutations in Northern India (6/204, 2.9%) than has been reported in other populations. However, given the limited extent of reported family history among these patients, the observed mutation frequency is not dissimilar from that reported in other cohorts of early onset breast cancer patients. Several of the identified mutations are unique and novel to Indian patients

Fractional flow reserve use in coronary artery revascularization: A systematic review and meta-analysis

Fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) is recommended in revascularization guidelines for intermediate lesions. However, recent studies comparing FFR-guided PCI with non-physiology-guided revascularization have reported conflicting results. PubMed and Embase were searched for studies comparing FFR-guided PCI with non-physiology-guided revascularization strategies (angiography-guided, intracoronary imaging-guided, coronary artery bypass grafting). Data were pooled by meta-analysis using random-effects model. 26 studies enrolling 78,897 patients were included. FFR-guided PCI as compared to non-physiology-guided coronary revascularization had lower risk of all-cause mortality (odds ratio [OR] 0.79 95% confidence interval [CI] 0.64-0.99, I2 = 53%) and myocardial infarction (MI) (OR 0.74 95% CI 0.59-0.93, I2 = 44.7%). However, no differences between groups were found in terms of major adverse cardiac events (MACEs) (OR 0.86 95% CI 0.72-1.03, I2 = 72.3%) and repeat revascularization (OR 1 95% CI 0.82-1.20, I2 = 43.2%). Among patients with coronary artery disease (CAD), FFR-guided PCI as compared to non-physiology-guided revascularization was associated with a lower risk of all-cause mortality and MI

Integration of a Continuum-Based Finite Element Tire Modeling Framework in Multibody Dynamics Algorithms

Flexible multibody systems (MBS) are systems of interconnected rigid and flexible bodies and are typically characterized by large reference translations and rotations. Examples of such systems include automotive vehicles, trains, aircrafts and musculoskeletal systems. The flexible bodies found in MBS models can be characterized by small and large deformation. The MBS dynamics literature consists of various methods of formulating the governing equations of motion, describing the MBS models and incorporating component flexibility. In case of flexible MBS models, the fidelity, accuracy and efficiency of the model will depend on the formulation and numerical methods used by the MBS software, which keep evolving and improving over time. The goal of this thesis is to develop a new computational framework for the modeling and integration of finite element (FE) tires in MBS dynamics algorithms. Historically tire modeling techniques used in MBS computer programs have consisted of curve-fitted analytical formulations, discrete/compliant-type elastic tire models and co-simulated classical FE models. This thesis proposes a new method of FE-based tire modeling that utilizes the absolute nodal coordinate formulation (ANCF) elements and can be systematically implemented in non-incremental MBS dynamics algorithms. The advantages of such a type of tire modeling are two-fold: the distributed inertia and elasticity of the tire can be successfully represented, and the model can exploit the existing MBS dynamics algorithms for obtaining efficient and reliable solutions. Along with the overall structural modeling aspects of tires, a new approach for the inclusion of surface geometry within ANCF FEs is developed, with tire tread details being a good example of such type of geometry. This thesis also reviews and discusses locking phenomena in classical FEs and fully parameterized ANCF beam and plate/shell elements and proposes a new locking alleviation technique called the strain split method. Finally, this thesis demonstrates the feasibility of developing new and detailed vehicle models that include many interconnected rigid and flexible bodies that could have structural discontinuities and are subjected to small and large deformation. The vehicle models developed and studied in this thesis includes a flexible chassis which is modeled using the floating frame of reference (FFR) formulation and pneumatic and airless tires which use the ANCF approach