Impurity-free intermixing of InGaAs/GaAs-strained multiple quantum well infrared photodetectors

Interdiffusion effect has been investigated in highly strained InGaAs/GaAs multiple quantum well (MQW) IR photodetector. Impurity-free interdiffusion techniques was utilized via rapid thermal annealing (RTA) using electron- beam evaporated SiO2 cap layers at temperature 850 degrees C to study the optical and electrical properties of the interdiffused photodetector. Photoluminescence (PL) spectrum is blue shifted and PL linewidth remains almost the same, indicating no strain relaxation and deterioration of the heterostructure quality. Both transverse magnetic and transverse electric IR intersubband transitions are retained and observed after intermixing. The absorption peak wavelength is red shifted continuously from the as grown 10.20 to the interdiffused 10.5 and 11.17 micrometers , respectively, without appreciable degradation in absorption strength for 5 and 10 s annealing. Annealed responsivity spectra of both 0 degrees and 90 degrees polarization are of compatible amplitude and red shifted but with narrower spectra linewidth. Dark current of the annealed devices is found to be an order of magnitude large than the as-grown one at 77K.published_or_final_versio

Outcome analysis of 71 clinical intestinal transplantations

Objective: The aim of the study was to determine risk factors associated with graft failure and mortality after transplantation of the intestine alone or as pad of an organ complex. Summary Background Data: Even with modern immunosuppressive therapies, clinical intestinal transplantation remains a difficult and unreliable procedure. Causes for this and solutions are needed. Methods: Between May 1990 and February 1995, 71 intestinal transplantations were performed in 66 patients using tacrolimus and low-dose steroids. The first 63 patients, all but one treated 1 to 5 years ago, received either isolated grafts (n = 22), liver and intestinal grafts (n = 30), or multivisceral grafts (n = 11). Three mere recipients of allografts who recently underwent surgery and one undergoing retransplantation were given unaltered donor bone marrow cells perioperatively as a biologic adjuvant. Results: Of the first 63 recipients, 32 are alive: 28 have functioning primary grafts and 4 have resumed total parenteral nutrition after graft enterectomy. Thirty-five primary grafts were lost to technical and management errors (n = 10), rejection (n = 6), and infection (n = 19). Regression analysis revealed that duration of surgery, positive donor cytomegalovirus (CMV) serology, inclusion of graft colon, OKT3 use, steroid recycle, and high tacrolimus blood levels contributed to graft loss. All four intestine and bone marrow recipients are alive for 2-3 months without evidence of graft- versus-host disease. Conclusion: To improve outcome after intestinal transplantation with previous management protocols, it will be necessary to avoid predictably difficult patients, CMV seropositive donors, and inclusion of the graft colon. Bone marrow transplantation may further improve outcome by ameliorating the biologic barriers of rejection and infection and allowing less restrictive selection criteria

Severe ileitis associated with capecitabine: Two case reports and review of the literature

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The utility of B-type natriuretic peptide in predicting postoperative cardiac events and mortality in patients undergoing major emergency non-cardiac surgery

B-type natriuretic peptide (BNP) levels predict cardiovascular risk in several settings. We hypothesized that they would identify individuals at increased risk of complications and mortality following major emergency non-cardiac surgery.Forty patients were studied with a primary end-point of a new post-operative cardiac event, and/or development of significant ECG changes, and/or cardiac death. The main secondary outcome was all cause mortality at 6 months. Preoperative BNP levels were higher in 11 patients who suffered a new postoperative cardiac event (p=0.001) and predicted this outcome with an area under the receiver operating characteristic curve of 0.85 (CI=0.72-0.98,p=0.001). A pre-operative BNP value >170pg.ml-1 has a sensitivity of 82% and a specificity of 79% for the primary end-point. In this small study, pre-operative BNP levels identify patients undergoing major emergency non-cardiac surgery who are at increased risk of early post-operative cardiac events. Larger studies are required to confirm these data.Peer reviewedPreprin

EIT and diffusion of atomic coherence

We study experimentally the effect of diffusion of Rb atoms on Electromagnetically Induced Transparency (EIT) in a buffer gas vapor cell. In particular, we find that diffusion of atomic coherence in-and-out of the laser beam plays a crucial role in determining the EIT resonance lineshape and the stored light lifetime.Comment: 5 pages, 8 figure

Aerosol modulation of ultraviolet radiation dose over four metro cities in india

This paper discusses the influence of aerosols on UV erythemal dose over four metro cities in India. Tropospheric Emission Monitoring Internet Service (TEMIS), archived UV-index (UV-I), and UV daily erythemal dose obtained from SCIAMACHY satellite were used in this study during June 2004 and May 2005 periods covering four important Indian seasons. UV-Index (UV-I), an important parameter representing UV risk, was found to be in the high to extreme range in Chennai (8.1 to 15.33), moderate to extreme range in Mumbai and Kolkata (5 to 16.5), and low to extreme over Delhi (3 to 15). Average UV erythemal dose showed seasonal variation from 5.9 to 6.3 KJm-2 during summer, 2.9 to 4.4 KJm-2 during postmonsoon, 3 to 4.5 KJm-2 during winter, and 5.1 to 6.19 KJm-2 during premonsoon seasons over the four cities. To estimate the influence of aerosols on reducing UV dose, UV aerosol radiative forcing and forcing efficiency were estimated over the sites. The average aerosol forcing efficiency was found to be from - 1.38 ± 0.33 to - 3.01 ± 0.28 KJm-2 AOD-1 on different seasons. The study suggests that aerosols can reduce the incoming UV radiation dose by 30-60 during different seasons. © 2014 A. S. Panicker et al

Aerosol modulation of ultraviolet radiation dose over four metro cities in India

This paper discusses the influence of aerosols on UV erythemal dose over four metro cities in India. Tropospheric Emission Monitoring Internet Service (TEMIS), archived UV-index (UV-I), and UV daily erythemal dose obtained from SCIAMACHY satellite were used in this study during June 2004 and May 2005 periods covering four important Indian seasons. UV-Index (UV-I), an important parameter representing UV risk, was found to be in the high to extreme range in Chennai (8.1 to 15.33), moderate to extreme range in Mumbai and Kolkata (5 to 16.5), and low to extreme over Delhi (3 to 15). Average UV erythemal dose showed seasonal variation from 5.9 to 6.3 KJm−2 during summer, 2.9 to 4.4 KJm−2 during postmonsoon, 3 to 4.5 KJm−2 during winter, and 5.1 to 6.19 KJm−2 during premonsoon seasons over the four cities. To estimate the influence of aerosols on reducing UV dose, UV aerosol radiative forcing and forcing efficiency were estimated over the sites. The average aerosol forcing efficiency was found to be from to  KJm−2 AOD−1 on different seasons. The study suggests that aerosols can reduce the incoming UV radiation dose by 30–60% during different seasons