Pr3+-doped CeF3 crystals: Analysis of optical traits and fluorescence from Pr3+: 1D2 level for visible and near-infrared lasers.

In this work, four Pr3+ -doped CeF3 crystals with 0.2, 0.4, 0.6, and 0.8 at.% Pr3+ ion doping levels nominally in the melt have been successfully grown, and their absorption and emission spectra, including fluorescence decay times were analyzed. Especially, yellow and near-infrared (NIR) emissions originating from Pr3+: 1D2 level were explored in detail. In comparison, 0.2 at.% Pr3+-doped sample showed better spectral parameters in all studied crystals. In such a crystal, at 443 nm wavelength, the derived absorption cross-section (σabs) is 0.88 × 10-20 cm2 with full width at half maximum (FWHM) âˆ¼ 10 nm in π polarization direction, whereas σabs is 1.32 × 10-20 cm2 with FWHM âˆ¼ 6.7 nm in σ polarization direction at the same wavelength. Likewise, the calculated emission cross-section (σem) for 594 nm wavelength is 0.69 × 10-20 cm2 in π direction and 0.46 × 10-20 cm2 in σ direction. Also, acquired σem at 790, 755, 1014, and 1432 nm wavelengths is 6.15 × 10-21 cm2, 7.33 × 10-21 cm2, 7.66 × 10-21 cm2, and 6.56 × 10-21 cm2 individually. Here evaluated fluorescence decay time of 1D2 level is âˆ¼ 200.6 µs. Obtained higher σabs, larger σem, and higher luminescence decay rates of 0.2 at.% Pr: CeF3 crystal specify its potential as a gain medium for orange and NIR lasers.

Elucidating the Infrared Spectral Properties of Succinic Molecular Acid Crystals: Illustration of the Structure and the Hydrogen Bond Energies of the Crystal and Its Deuterated Analogs.

Herein, the infrared spectroscopic properties of molecular succinic acid crystals (SA) and their four isotopic analogs [C2H4(COOH)2, h6-SA; C2H4(COOD)2, d2-SA; C2D4(COOH)2, d4-SA; C2D4(COOD)2, d6-SA] are reported. The correlation between the structure of succinic acid molecules and their corresponding hydrogen bond energies is elucidated. The effects related to the isotopic dilution as well as the changes in the spectrum recording temperature on the fine structures of the vO-H and vO-D bands are interpreted. The infrared spectral anomalies detected in the spectra of isotopically neat succinic nanocrystal acids are confirmed by theoretical calculations using density functional theory (DFT). According to previous spectroscopic studies of succinic acid and those carried out for α,ω-dicarboxylic acids, a decent agreement between the experimental results and the theoretical DFT simulations is obtained. Moreover, the spectra of single crystals of the h6 and d4 succinic acid variants prove that the vibrational coupling mechanism between the (COOH)2 cycles is rigorously convergent to that detected in the spectra of aromatic carboxylic acids, suggesting thereby that the promotion of symmetry-forbidden high stretching IR transitions plays a crucial role. Furthermore, the obtained experimental results reveal that the succinic acid shows a spectral behavior significantly different from that characteristic of hydrogen associations of other acids of homologous series, such as the glutaric, adipic, malonic, and pimelic acid crystals. The results obtained herein shed light on the way to explore the revealed structure of isotopic derivatives of succinic acid crystals and may prove to be useful results for understanding the nature of unconventional interactions as well as the macroscopic energy effects directing the development of hydrogen associations.

Choice of Regional Flaps for Oral Cancer Defects: Relevance in Current Era.

INTRODUCTION: Microvascular free flaps (MVFF) are the current standard of care for reconstruction of oral ablative defects; however, pedicled myocutaneous flaps (PMCF) are still used widely in India. The rationale behind the preference for selecting PMCF in the present era is not well understood. The associated complications and swallowing outcomes are variable. METHODS: We retrospectively analysed the records of patients who underwent reconstructive surgery for oral cancer ablative defects over a 3-year period. RESULTS: Ninety-seven pedicled myocutaneous flaps [89 pectoralis major myocutaneous (PMMC) flaps, eight lower trapezius island myocutaneous (TMC) flaps] and 113 MVFFs were performed. The reasons for selecting PMCF were financial constraints 38.7%, MVFF salvage 22.5%, medically compromised 10.7%, vessel-depleted neck 6.4%, old age with PS2 + 5.3%, early recurrence 5.3%, borderline resectable 4.3%, palliative resection 2.1%. Overall complication rate was 20.4%. Of patients, 50.7% and 34.7% were on regular and semisolid diet, respectively; 66.6% had acceptable swallowing-related social well-being. CONCLUSION: PMCFs have an important role in developing countries with patients having financial constraints. The other potential reasons driven by patient factors were discussed. The swallowing outcomes are good, with majority of the people having socially acceptable swallowing function.

Composite Pheochromocytoma: A Rare Form of Tumor.

The pheochromocytomas are one of the rare and curable causes of secondary hypertension arising from adrenal medulla, commonly presenting with hypertension; either paroxysmal or persistent. Very rarely they may show cells belonging to more than one line of differentiation and are called as mixed or composite pheochromocytoma.

Flat amplitude and wide multiwavelength Brillouin/erbium fiber laser based on Fresnel reflection in a micro-air cavity design.

In this report, we demonstrate a wide multiwavelength Brillouin-erbium fiber laser (MBEFL) with improved flatness that integrates a micro-air cavity. This air-gap introduces a cavity loss to overcome the gain saturation as well as providing efficient pump recycling scheme through Fresnel back-reflection. In addition, the efficient four-wave mixing in the highly nonlinear fiber contributes to the self-flattening of the output spectra. During operation, the optimized pumping values are set at 13 dBm Brillouin power and 600 mW erbium-ytterbium doped fiber amplifier when the air-gap length is fixed at 10 µm. A total of 180 Stokes lines are produced with a channel spacing of 0.08 nm. The flat lasing bandwith is 14 nm that consists of 1557 to 1571 nm wavelengths within 3-dB span. The average optical signal-to-noise ratio is 18 dB, having high peak power of -8 dBm. To our knowledge, this is the best result attained in MBEFLs with respect to the spectral flatness. In fact, the power stability of 0.76 dB order over 45 minute durations merits it applications in optical fiber sensing and communications.

Hemodialysis outcomes and practice patterns in end-stage renal disease: Experience from a Tertiary Care Hospital in Kerala.

This study was planned to analyze the hemodialysis practice patterns from a tertiary care referral centre as there is very limited data from India. All patients of ESRD on maintenance hemodialysis (MHD) in dialysis unit at AIMS, Kochi, Kerala for a minimum period of 3 months were included. A total of 134 patients (M: F 2:1) with age of 20 to 84 years (Mean: 59.83; SD: 11.98) were studied. The most common causes of ESRD in study population were diabetic nephropathy (DN) (59.7%) followed by unclassified group (19.4%), chronic glomerulonephritis (CGN) (11.9%). Majority (81%) were initiated on MHD through temporary vascular access on emergency basis. Majority (79%) of the patients were on twice weekly MHD. The range of eGFR (ml/min/1.73 m2) at the time of initiation of MHD was 1.26-11.78 by CG formula and 2.18-16.4 by MDRD equation. The mean duration on hemodialysis was 37.16 months and 50.7% patients had died during the follow-up period (3-108 months). The mean survival time on hemodialysis was 40.31 months (SD = 26.69). The mean survival time was lower in diabetic nephropathy (35.93 months) than in non-diabetic renal disease (47.46 months). The most common causes of deaths were cardiovascular events (51.5%), and infections (26.5%). In conclusion, males outnumbered females, among those on hemodialysis. There was no significant difference in eGFR at initiation of MHD based on etiologies. Initiation of MHD via temporary access, presence of LVH, acute coronary syndrome, use of acetate dialysate, need for parenteral iron therapy had impact on mortality. Survival rates while on hemodialysis at end 1st, 3rd, 5th and 7th years were 87.31, 45.52, 21.64 and 7.46 percentages respectively.

Is early removal of prophylactic ureteric stents beneficial in live donor renal transplantation?

Prophylactic ureteric stenting has been shown to reduce ureteric leaks and collecting system obstruction following renal transplantation and is in widespread use. However, the optimal time for removal of ureteric stents after renal transplantation remains unclear. Aim of this study was to compare the result of early versus late removal of ureteric stents after kidney transplantation of the laparoscopically retrieved live related donor grafts. Eligible patients were live donor kidney transplant recipients with normal urinary tracts. All recipients underwent extravesical Lich-Gregoire ureteroneocystostomy over 4F/160 cm polyurethane double J stents by a uniform technique. They were randomized on seventh postoperative day for early removal of stents on postoperative day 7 (Group I), or for late removal on postoperative day 28 (Group II). The incidence of urinary tract infections, asymptomatic bacteriuria, and urological complications were compared. Between 2007 and 2009, 130 kidney transplants were performed at one centre of which 100 were enrolled for the study, and 50 each were randomized into the two groups. Donor and recipient age, sex, native renal disease, immunosupression, number of rejection episodes, and antirejection therapy were similar in the two groups. The occurrence of symptomatic urinary tract infection during the follow-up period of 6 months was significantly less in the early stent removal group [5 out of 50 (10%) in Group I, vs 50 out of 15 (30%) in Group II, P=0.02]. Asymptomatic bacteriuria was documented in 2 out of 50 (4%) in Group I and 4 out of 50 (8%) in Group II (P=0.3). There was no statistically significant difference in the rate of ureteric leak, ureteric obstruction, or hematuria in the two groups (P=1.0). We conclude that, in kidney transplant recipients of laparoscopically retrieved live donor grafts, early stent removal at the end of first week reduces the incidence of urinary tract infection without increasing the rate of urine leak or ureteric obstruction.

Photoinduced spectra for magneto electric (1-x)BiFeO3-xCuFe2O4 nanocomposites.

In this work, we demonstrate possibility to use spectra of the parametrically tuned laser beam for operation by magnetoelectric properties of the (1-x)BiFeO(3-)(x)CuFe(2)O(4) (BFCI). The role of the photoexcited wavelength is crucial due to photoexcited phonons. It may indicate on a spectral sensitivity of the studied nanocomposites. We have studied spectral dependences of magneto-electric constant versus the magnetic field frequency for different sizes of the nanoparticles with and without the nanosecond laser pulses illumination and we have shown an occurrence of principal spectral shifts in the corresponding magneto-electric maxima. Additionally we have explored relative changes of dielectric permittivity and coercivity versus different photoinducing wavelengths. The performed experiments unambiguously show that the external laser treatment will lead to substantial shift of corresponding dielectric and magnetic parameters in the studied nanocomposites. It is principally the finding of clear spectral dependences for the mentioned dielectric and magnetic parameters. One can see their sensitivity to the photoinduced wavelength which reflects the photoexcitations of different part of wavelengths. One can see the spectral shift up to 100 nm for the two principal spectral maxima with respect to the dielectric and magnetic changes which may indicate on the two principally different contributions to the effects observed.

Bilateral emphysematous pyelonephritis in autosomal dominant polycystic kidney disease.

Emphysematous pyelonephritis (EPN) is an uncommon infection of renal parenchyma with gas-forming organisms. EPN is usually seen in patients with diabetes mellitus (DM). The association of EPN with conditions other than DM is extremely rare. We report a case of autosomal dominant polycystic kidney disease with bilateral EPN who had to undergo bilateral nephrectomy.

Optical and photoconductivity spectra of novel Ag2In2SiS6 and Ag2In2GeS6 chalcogenide crystals.

Complex spectral studies of near-band gap and photoconductive spectra for novel Ag(2)In(2)SiS(6) and Ag(2)In(2)GeS(6) single crystals are presented. The spectral dependences of photoconductivity clearly show an existence of spectral maxima within the 450 nm-540 nm and 780 nm-920 nm. The fundamental absorption edge is analyzed by Urbach rule. The origin of the spectral photoconductivity spectral maxima is discussed. Temperature dependences of the spectra were done. The obtained spectral features allow to propose the titled crystals as photosensors. An analysis of the absorption and photoconductivity spectra is given within a framework of oversimplified spectroscopic model of complex chalcogenide crystals.

Hennekam lymphangiectasia syndrome.

Hennekam lymphangiectasia syndrome is a rare disorder comprising of intestinal and renal lymphangiectasia, dysmorphic facial appearance and mental retardation. The facial features include hypertelorism with a wide, flat nasal bridge, epicanthic folds, small mouth and small ears. We describe a case of a multigravida with bad obstetric history and characteristic facial and dental anomalies and bilateral renal lymphangiectasia. To our knowledge this is the first case of Hennekam lymphangiectasia syndrome with anodontia to be reported from India.

Quantum chemical simulations of solvent influence on UV-vis spectra and orbital shapes of azoderivatives of diphenylpropane-1,3-dione.

The DFT modeling of novel synthesized azoderivatives of ß-diketones - 2-(2-(2-hydroxyphenyl)hydrazono)-1,3-diphenylpropane-1,3-dione (1), 2-(2-(2-hydroxy-4-nitrophenyl)hydrazono)-1,3-diphenylpropane-1,3-dione (2), 3-(2-(1,3-dioxo-1,3-diphenylpropan-2-ylidene)hydrazinyl)-2-hydroxy-5-nitrobenzene sulfonic acid (3), 2-(2-(1,3-dioxo-1,3-diphenylpropan-2-ylidene)hydrazinyl)benzenesulfonic acid (4), 2-(2-(1,3-dioxo-1,3-diphenylpropan -2-ylidene)hydrazinyl)benzoic acid (5), 2-(2-(2-hydroxy-4-nitrophenyl)hydrazono)-1-phenylbutane-1,3-dione (6) were performed. The collected information confirms that 1-5 exist in hydrazo form, being stabilized by the intramolecular hydrogen bonds in DMSO solution and solid phase, while 6 exists in mixed enol-azo and hydrazo tautomeric forms, the latter dominating in more polar solvents. The relative stability of various tautomeric and izomeric forms of the symmetric 1-5 and unsymmetric 6 azoderivatives of ß-diketones is calculated based on the density functional theory (DFT). Polarizable Continuum Model was used to simulate solvatochromic effects. Solvents of different polarities were used to collect experimental spectra, and the same solvents were chosen for the PCM calculations. The optical properties of 1-6 have been investigated by density functional theory and its electronic absorption bands have been assigned by time-dependent density functional theory (TD-DFT).

Zygomycosis in a renal allograft recipient.

Invasive fungal infections can cause considerable morbidity and mortality in immunocompromised patients. Zygomycosis is a type of invasive fungal infection with a rapid course and grave prognosis. Renal transplant recipients with concomitant diabetes mellitus are most susceptible to this infection. We report here a case of disseminated zygomycosis (Rhizopus sp.) in a renal allograft recipient with posttransplant diabetes mellitus (PTDM). This is the first reported case of zygomycosis caused by Rhizopus species.

Cyan-white-red luminescence from europium doped Al2O3-La2O3-SiO2 glasses.

Aluminum-lanthanum-silicate glasses with different Eu doping concentration have been synthesized by conventional melt-quenching method at 1680 degrees C in reductive atmosphere. Under 395nm excitation, samples with low Eu doping concentration show mainly the cyan broad emission at 460nm due to 4f(6)5d(1)-4f(7) transition of Eu(2+); and the samples with higher Eu doping concentration show mainly some narrow emissions with maximum at 616nm due to (5)D(0)-(7)F(j) (J=0, 1, 2, 3, 4) transitions of Eu(3+). Cyan-white-red tunable luminescence under 395nm excitation has been obtained by changing the Eu doping concentration.

Thrombotic microangiopathy with severe renal failure in adenocarcinoma.

Kidney disease frequently complicates malignancy and its treatment. The spectrum of renal disease in cancers includes acute kidney injury, chronic kidney disease and tubular disorders. Thrombotic microangiopathy (TMA) is an uncommon initial clinical presentation of malignancies. Renal failure is an extremely rare feature of cancer-associated TMA syndromes in the absence of chemotherapy. Here, we report a patient who presented to the hospital for the first time with TMA and severe renal failure requiring hemodialysis and was diagnosed with gastric adenocarcinoma.

Recurrent hemolytic uremic syndrome.

Hemolytic uremic syndrome (HUS) is an uncommon cause of acute renal failure. Diarrhea-associated (D+) HUS, usually seen in children, is a common variety of HUS. HUS that is not associated with diarrhea (D-) is caused by a heterogeneous group of disorders. We report here a case of recurrent HUS (D-) in an adult female with hypocomplementemia.

Spectral analysis of Er(3+)-, Er(3+)/Yb(3+)- and Er(3+)/Tm(3+)/Yb(3+)-doped TeO(2)-ZnO-WO(3)-TiO(2)-Na(2)O glasses.

In this paper, we present the spectroscopic properties of Er(3+)-, Er(3+)/Yb(3+)- and Er(3+)/Tm(3+)/Yb(3+)-doped novel tellurite glasses. From the measured absorption spectra, Judd-Ofelt (JO) intensity parameters (Ω(2), Ω(4) and Ω(6)) have been evaluated for the Er(3+)-doped glass. With 980 nm excitation three strong upconversion emission bands centered at 505, 520 and 630 nm were observed for both Er(3+)- and Er(3+)/Yb(3+)-codoped glasses and the characteristic near-infrared emission bands were spectrally centered at 1.535 µm. The near-infrared spectra of Er(3+)- and Er(3+)/Yb(3+)-doped glasses have shown full width at half-maxima (FWHM) around 100 nm and 120 nm for the erbium [Formula: see text] transition, respectively. The measured maximum decay times of the [Formula: see text] transition (at wavelength 1.535 µm) are about 7.24 ms and 7.68 ms for 1.0Er(3+) and 1.0Er(3+)/ 2Yb(3+) (mol%)-codoped glasses, respectively. The maximum stimulated emission cross sections for the [Formula: see text] transition of Er(3+) and Er(3+)/Yb(3+) are 8.64 × 10(-21) and 6.78 × 10(-21) cm(2). From 1Er(3+)/ 1Tm(3+)/ 2Yb(3+) (mol%)-codoped glass, broad near-infrared emission bands centered at 1510 nm ([Formula: see text]) and 1637 nm ([Formula: see text]) with full width at half-maxima (FWHM) around 52 nm and 60 nm, respectively, were observed. These glasses with broad near-infrared emissions should have potential applications in tunable lasers and broadband optical amplification at low-loss telecommunication windows.

Spectral analysis of RE(3+) (RE = Er, Nd, Pr and Ho):GeO(2)-B(2)O(3)-ZnO-LiF glasses.

This paper reports on the absorption, visible and near-infrared luminescence properties of Er(3+), Nd(3+), Pr(3+) and Ho(3+)-doped alkali fluoride zinc boro germanate glasses. The x-ray diffraction (XRD) and differential thermal analysis (DTA) profiles of the host glass have been carried out, to confirm its structure and thermal stability. From the measured absorption spectra, Judd-Ofelt (JO) intensity parameters (Ω(2), Ω(4) and Ω(6)) have been calculated for all the studied ions. For Pr(3+) and Ho(3+)-doped glasses, upconversion emission spectra have also been measured. Decay curves were measured for the visible emissions of Er(3+), Pr(3+) and Ho(3+) ions at 547 nm (Er(3+): green), 604 nm and 641 nm (Pr(3+): orange and red) and 658 nm (Ho(3+): red), respectively. The near-infrared emission spectra of Er(3+)/Yb(3+) and Nd(3+)-doped glasses have shown full width at half maximum (FWHM) around 95 nm (for the [Formula: see text] transition) and 63 nm (for the [Formula: see text] transition), respectively. The measured maximum decay times of [Formula: see text] transition (at wavelength 1.51 µm) are about 5.72 ms and 6.14 ms for 1.0Er(3+) and 1.0Er(3+)/ 2Yb(3+) (mol%)-codoped glasses, respectively. The maximum stimulated emission cross sections for [Formula: see text] transition of Er(3+) and Er(3+)/Yb(3+) are 5.447 × 10(-21) cm(2) and 4.540 × 10(-21) cm(2). These glasses with better thermal stability, bright visible emissions and broad near-infrared emissions should have potential applications in broadly tunable laser sources, interesting optical luminescent materials and broadband optical amplification in low-loss telecommunication windows.

Spectral analysis of Mn2+, Co2+ and Ni2+: B2O3-ZnO-PbO glasses.

This paper reports on the spectral properties of Mn2+, Co2+ and Ni2+ ions doped B2O3-ZnO-PbO glasses. XRD, FT-IR spectra and DSC profiles of these glasses have also been carried out, and the FT-IR profiles have shown the presence of both BO3 and BO4 units. It is interesting to notice that the FT-IR peak positions are slightly shifted towards higher energy with an increase in transition metal ion concentration change. From the measured DSC thermograms, glass transition (T(g)), crystallization (T(c)) and temperature of melting (T(m)) have been evaluated. From the UV absorption spectra of Mn2+, Co2+ and Ni2+ ions doped glasses, both direct and indirect optical band gaps have been calculated. The visible absorption spectra of Mn2+:glasses have shown a broad absorption band at 520 nm (6A1g(S) --> 4T1g(G)); with Co2+ ions one absorption band at 605 nm (4A2(4F) --> 4T1(4P)) and another at 1450 nm (4A2(4F) --> 4T1(4F)); and for Ni2+:glasses three absorption bands at 420 nm (3A2g(F) --> 3T1g(P)), 805 nm (3A2g(F) --> 1Eg(D)) and 880 nm (3A2g(F) --> 3T1g(F)) have been observed. For Mn2+:glasses, upon excitation with 262 nm, a green emission (539 nm) with a slight blue shift; and with 392 nm, a green emission (534 nm) with a slight red shift with Mn2+ ions concentration change (0.2-0.5 mol%) has been observed. This green emission has been assigned to (4T1(G) --> 6A1(S)) d-d transition of Mn2+ ions that are in tetrahedral co-ordination. For 0.5 mol% Co2+ ions doped glass, upon excitation with 580 nm, a red emission (625 nm) has been observed which originates from 2E(2G) --> 4A2(4F) transition of Co2+ ions in tetrahedral co-ordination. For Ni2+ ions doped glasses upon excitation with 420 nm, a green (577 nm) and red (670 nm) emissions are observed and are assigned to (1T2g(D) --> 3A2g(F)) and (1T2g(D) --> 3T2g(F)) d-d transitions of Ni2+ ions in octahedral co-ordination.