Photo-thermal Processing of Semiconductor Fibers and Thin Films

Furnace processing and rapid thermal processing (RTP) have been an integral part of several processing steps in semiconductor manufacturing. The performance of RTP techniques can be improved many times by exploiting quantum photo-effects of UV and vacuum ultraviolet (VUV) photons in thermal processing and this technique is known as rapid photo-thermal processing (RPP). As compared to furnace processing and RTP, RPP provides higher diffusion coefficient, lower stress and lower microscopic defects. In this work, a custom designed automated photo assisted processing system was built from individual parts and an incoherent light source. This photo-assisted processing system is used to anneal silica clad silicon fibers and deposit thin-films. To the best of our knowledge, incoherent light source based rapid photo-thermal processing (RPP) was used for the first time to anneal glass-clad silicon core optical fibers. X-ray diffraction examination, Raman spectroscopy and electrical measurements showed a considerable enhancement of structural and crystalline properties of RPP treated silicon fibers. Photons in UV and vacuum ultraviolet (VUV) regions play a very important role in improving the bulk and carrier transport properties of RPP-treated silicon optical fibers, and the resultant annealing permits a path forward to in situ enhancement of the structure and properties of these new crystalline core optical fibers. To explore further applications of RPP, thin-films of Calcium Copper Titanate (CaCu3Ti4O12) or CCTO and Copper (I) Oxide (Cu2O) were also deposited using photo-assisted metal-organic chemical vapor deposition (MOCVD) on Si/SiO2 and n-Si substrate respectively. CCTO is one of the most researched giant dielectric constant materials in recent years. The given photo-assisted MOCVD approach provided polycrystalline CCTO growth on a SiO2 surface with grain sizes as large as 410 nm. Copper (I) oxide (Cu2O) is a direct band gap semiconductor with p-type conductivity and is a potential candidate for multi-junction solar cells. X-ray diffraction study revealed a preferred orientation, as (200) oriented crystals of Cu2O are grown on both substrates. Also, electrical characterization of Cu2O/n-Si devices showed the lowest saturation current density of 1.5x10-12 A/cm2 at zero bias. As a result, photo-assisted thermal processing has the potential of making the process more effective with enhanced device performance

ANTICANCER DRUGS AS PROSPECTIVE EFFLUX PUMP INHIBITORS FOR SALMONELLA TYPHI PRODUCE CONFLICTING RESULTS IN IN SILICO AND IN VITRO STUDIES

Objective: Anticancer drugs paclitaxel and vinblastine were tested for their potential as efflux pump inhibitors for Salmonella Typhi-based on in silico and in vitro studies.Methods: Three-dimensional protein models of AcrAB-TolC of Salmonella Typhi were generated by online server PHYRE-2. The quality of 3D structures was assessed by PROCHECK, SWISS MODEL. Docking analysis of anticancer drugs with AcrA, AcrB and TolC subunits were performed after refining the homology models with Modrefiner. Salmonella Typhi (S. Typhi) efflux pump activity was measured by ethidium bromide (EtBr) cartwheel and semi-automated fluorometry methods respectively. Fluorescence intensity in bacterial colonies was measured under different treatment conditions (with or without drugs) on Muller Hinton agar (MHA) plates containing EtBr in cartwheel assay. EtBr efflux assay was determined following the loading of bacteria with EtBr and fluorescence was recorded over fixed time period with the help of fluorescent spectrophotometer. The results obtained were compared with the control.Results: Efflux pump inhibitor (EPIs) activity of paclitaxel and vinblastine determined by EtBr cartwheel assay registered no activity whereas semi-automated fluorescent assay revealed marginal activity when compared to control.Conclusion: We report the conflicting result of in silico and in vitro studies in predicting the antimicrobial effect of mainstream anticancer drugs as efflux pump inhibitors for Salmonella Typhi

Study of Association between Lichen Planus and Hepatitis C Virus Infection

INTRODUCTION: Lichen planus is an immunologically mediated skin and mucous membrane disease, which can affect oral mucosa, the skin, genitalia, hair follicles, nails, esophagus, urinary tract, nasal mucosa, larynx and even the eyes. Lichen planus has been found in patients with Hepatitis C virus related liver disease, with variable frequency in several studies till date. However an association between HCV infection and lichen planus is uncertain because prevalence of HCV infection in patients with lichen planus varies considerably from one geographic area to another. If there is a true association, lichen planus in certain populations may be used as a sign of HCV infection in asymptomatic patients, leading to early diagnosis and treatment, and a better prognosis of infected patients. AIM AND OBJECTIVE: To study the association between Lichen planus and Hepatitis C infection in this geographical region. MATERIALS AND METHODS: Place: Govt. Stanley Medical College, Chennai. Type: Prospective, Observational TIME: July 2013 to June 2014. Sample SizE: 100 lichen planus patients, 100 controls. EXCLUSION CRITERIA: 1. Patients taking drugs causing lichenoid eruptions like beta- blockers, anti-malarials, diuretics, ACE inhibitors, chlorpropamide, simvastatin. 2. Pregnant/Lactating woman, 3. Pre-existing liver disease, 4. Past history of blood transfusion, 5. Intravenous drug users, 6. Blood dyscrasias like haemophilia, 7. Patients not willing for screening. RESULTS AND CONCLUSION: The present study shows no association between lichen planus and hepatitis C infection. Based on this result, it can be concluded that anti-HCV antibody testing is not necessarily required in lichen planus patients having no risk factors for HCV infection in this geographic region

A Study of a Plug to Counter Wind Forces

The wind loads are one of the greatest environmental threats that exist for a building. Coastal areas close to the equator are especially prone to damage caused by cyclonic wind loads. Historical data shows that there has been a long history of cyclonic activities causing devastating damage to life and property. The legendary storm that saved Japan from invasion about a millennia ago is one such example. Recent cyclones, such as Typhoon Tip in 1979 and Cyclone Tracy in 1974, have been responsible for causing billions of dollars’ worth damage and killing a significant number of people. The maximum gust speed recorded to date, over 200 mph, is capable of destroying a building. Various building codes and regulations are based on international research that covers the design of buildings for high winds. At higher wind speeds, as seen in cases of cyclones and tornedoes, the external pressure on the buildings shell increases as the square of the wind speed. One of the failure modes for buildings is a catastrophic failure of the window elements in a high-pressure windstorm. The failure creates a resonance, named after Herrmann von Helmholtz, that overloads the roof and walls from the wind pressure and the mass movement of air. A new device was developed in this research to smoothen the transition from a closed to open state for a buildings opening. The device has a controlled failure of a plug element. The purpose of the research was to develop a test arrangement to generate cyclonic wind pressures inside a box container to test failure load for the plug. The results show that a plug with a friction joint between the pipe could be used to control the flow of air from the exterior to the interior of a room at a pre-determined pressure inside the box. The system was found to work and able to create a low level of damping to model the Helmholtz resonator. Further research is recommended using different plug samples

Robust Lossless Semi Fragile Information Protection in Images

Internet security finds it difficult to keep the information secure and to maintain the integrity of the data. Sending messages over the internet secretly is one of the major tasks as it is widely used for passing the message. In order to achieve security there must be some mechanism to protect the data against unauthorized access. A lossless data hiding scheme is proposed in this paper which has a higher embedding capacity than other schemes. Unlike other schemes that are used for embedding fixed amount of data, the proposed data hiding method is block based approach and it uses a variable data embedding in different blocks which reduces the chances of distortion and increases the hiding capacity of the image. When the data is recovered the original image can be restored without any distortion. Our experimental results indicate that the proposed solution can significantly support the data hiding problem. We achieved good Peak signal-to-noise ratio (PSNR) while hiding large amount of data into smoother regions

sl2^\widehat{sl_2} symmetry of R1,3{\mathbb R}^{1,3} gravity

We propose novel asymptotically locally flat boundary conditions for Einstein Gravity without cosmological constant in four dimensions that are consistent with the variational principle. They allow for complex solutions that are asymptotically diffeomorphic to flat space-times under complexified diffeomorphisms. We show that the resultant asymptotic symmetries are an extension of the Poincare algebra to a copy of Virasoro, a chiral $\mathfrak{sl}(2,{\mathbb C})$ current algebra along with two chiral $\mathfrak{u}(1)$ currents. We posit that these bulk symmetries are direct analogues of the recently discovered chiral algebra symmetries of gravitational scattering amplitudes as celestial CFT correlation functions.Comment: 33 pages. References added. Added a new subsection 'Comment on Charges'. Elaborated Introduction, Conclusion and Discussion sections. Minor typos correcte

Effect of fixed dose combinations of different α1-blockers with dutasteride on quality of life in patients of lower urinary tract symptoms with benign prostatic hyperplasia

Background: Fixed dose combination (FDC’s) of α1-blockers and 5α-reductase inhibitors have commonly been used in patients with lower urinary tract symptoms (LUTS) and benign prostatic hyperplasia (BPH). This study compared the effect of FDC’s of tamsulosin, alfuzosin and silodosin with dutasteride on quality of life (QoL) in patients of LUTS with BPH.Methods: Ninety-six male patients aged ≥45 years diagnosed with LUTS and BPH were randomized to receive FDC’s of dutasteride with tamsulosin (group 1), alfuzosin (group 2) and silodosin (group 3) over a period of 16 weeks. Quality of life was assessed using International Prostate Symptom Score (IPSS) 8th question, BPH impact index (BII) and modified Patient Perception of Study Medication (PPSM) questionnaire.Results: IPSS 8th question score improved significantly by 61.68%, 57.63% and 63.4% in group 1, 2 and 3 respectively. BPH Impact Index score also improved significantly by 62.95%, 60.13% and 61.82% in group 1, 2 and 3 respectively. All the three treatments were found to be similar in improving the QoL. Majority of patients were satisfied with their treatment and wanted to receive the medication again while a small number of patients were neutral with the study medication. None of the subjects was dissatisfied with any of the treatment.Conclusions: All the FDC’s improved QoL and were found to be satisfactory as per patient perception of study medications

Epidemiology of cardioprotective pharmacological agent use in stable coronary heart disease

AbstractObjectiveTo determine use of class and type of cardioprotective pharmacological agents in patients with stable coronary heart disease (CHD) we performed a prescription audit.MethodsA cross sectional survey was conducted in major districts of Rajasthan in years 2008–09. We evaluated prescription for classes (anti-platelets, β-blockers, angiotensin converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARB), calcium channel blockers (CCB) and statins) and specific pharmacological agents at clinics of physicians in tertiary (n = 18), secondary (n = 69) and primary care (n = 43). Descriptive statistics are reported.ResultsPrescriptions of 2290 stable CHD patients were audited. Anti-platelet use was in 2031 (88.7%), β-blockers 1494 (65.2%), ACE inhibitors 1196 (52.2%), ARBs 712 (31.1%), ACE inhibitors – ARB combinations 19 (0.8%), either ACE inhibitors or ARBs 1908 (83.3%), CCBs 1023 (44.7%), statins 1457 (63.6%) and other lipid lowering agents in 170 (7.4%). Among anti-platelets aspirin–clopidogrel combination was used in 88.5%. Top three molecules in β-blockers were atenolol (37.8%), metoprolol (26.4%) and carvedilol (11.9%); ACE inhibitors ramipril (42.1%), lisinopril (20.3%) and perindopril (10.9%); ARB's losartan (47.7%), valsartan (22.3%) and telmisartan (14.9%); CCBs amlodipine (46.7%), diltiazem (29.1%) and verapamil (9.5%) and statins were atorvastatin (49.8%), simvastatin (28.9%) and rosuvastatin (18.3%). Use of metoprolol, ramipril, valsartan, diltiazem and atorvastatin was more at tertiary care, and atenolol, lisinopril, losartan, amlodipine and simvasatin in primary care (p < 0.01).ConclusionsThere is low use of β-blockers, ACE inhibitors, ARBs and statins in stable CHD patients among physicians in Rajasthan. Significant differences in use of specific molecules at primary, secondary and tertiary healthcare are observed