Controlling Intramolecular Singlet Fission Dynamics via Torsional Modulation of Through-Bond versus Through-Space Couplings.

Covalent dimers, particularly pentacenes, are the dominant platform for developing a mechanistic understanding of intramolecular singlet fission (iSF). Numerous studies have demonstrated that a photoexcited singlet state in these structures can rapidly and efficiently undergo exciton multiplication to form a correlated pair of triplets within a single molecule, with potential applications from photovoltaics to quantum information science. One of the most significant barriers limiting such dimers is the fast recombination of the triplet pair, which prevents spatial separation and the formation of long-lived triplet states. There is an ever-growing need to develop general synthetic strategies to control the evolution of triplets following iSF and enhance their lifetime. Here, we rationally tune the dihedral angle and interchromophore separation between pairs of pentacenes in a systematic series of bridging units to facilitate triplet separation. Through a combination of transient optical and spin-resonance techniques, we demonstrate that torsion within the linker provides a simple synthetic handle to tune the fine balance between through-bond and through-space interchromophore couplings that steer iSF. We show that the full iSF pathway from femtosecond to microsecond timescales is tuned through the static coupling set by molecular design and structural fluctuations that can be biased through steric control. Our approach highlights a straightforward design principle to generate paramagnetic spin pair states with higher yields.

Entrapped Molecule-Like Europium-Oxide Clusters in Zinc Oxide with Nearly Unaffected Host Structure.

Nanocrystalline ZnO sponges doped with 5 mol% EuO1.5 are obtained by heating metal-salt complex based precursor pastes at 200-900 °C for 3 min. X-ray diffraction, transmission electron microscopy, and extended X-ray absorption fine structure (EXAFS) show that phase separation into ZnO:Eu and c-Eu2 O3 takes place upon heating at 700 °C or higher. The unit cell of the clean oxide made at 600 °C shows only ≈0.4% volume increase versus undoped ZnO, and EXAFS shows a ZnO local structure that is little affected by the Eu-doping and an average Eu3+ ion coordination number of ≈5.2. Comparisons of 23 density functional theory-generated structures having differently sized Eu-oxide clusters embedded in ZnO identify three structures with four or eight Eu atoms as the most energetically favorable. These clusters exhibit the smallest volume increase compared to undoped ZnO and Eu coordination numbers of 5.2-5.5, all in excellent agreement with experimental data. ZnO defect states are crucial for efficient Eu3+ excitation, while c-Eu2 O3 phase separation results in loss of the characteristic Eu3+ photoluminescence. The formation of molecule-like Eu-oxide clusters, entrapped in ZnO, proposed here, may help in understanding the nature of the unexpected high doping levels of lanthanide ions in ZnO that occur virtually without significant change in ZnO unit cell dimensions.

Optical closure in highly absorptive coastal waters: significance of inelastic scattering processes.

In hydrological optics, "optical closure" means consistency between the apparent optical properties (AOPs) determined from radiometric measurements and those derived from radiative transfer modelling based on concurrently measured inherent optical properties (IOPs) and boundary conditions (sea and sky states). Good optical closure not only provides confidence in the data quality but also informs on the adequacy of the radiative transfer parameterization. Achieving optical closure in highly absorptive coastal waters is challenging due to the low signal-to-noise ratio of radiometric measurements and uncertainties in the measurements of IOPs, namely the spectral absorption and backscattering coefficients. Here, we present an optical closure assessment using a comprehensive set of in situ IOPs acquired in highly absorptive coastal waters optically dominated by chromophoric dissolved organic matter (CDOM). The spectral remote sensing reflectance, Rrs(λ), was modeled using the software HydroLight (HL) with measured IOPs and observed boundary conditions. Corresponding in-water in situ Rrs(λ) was derived from radiometric measurements made with a Compact Optical Profiling System (C-OPS; Biospherical). The assessment revealed that the inclusion of inelastic scattering processes in the model, specifically sun-induced CDOM fluorescence (fDOM) and sun-induced chlorophyll fluorescence (SICF) from Chlorophyll-a ([chl]), significantly improved the optical closure and led to good agreement between measured and modeled Rrs (i.e., for 440 ≤ λ ≤ 710 nm with no inelastic processes: R2=0.90, slope=0.64; with inelastic processes: R2=0.96, slope=0.90). The analysis also indicated that fDOM and SICF contributed a substantial fraction of the green-red wavelength Rrs in these waters. Specifically, fDOM contributed ∼18% of the modeled Rrs in the green region and SICF accounted for ∼20% of the modeled Rrs in the red region. Overall, this study points out the importance of accounting for fDOM in remote sensing applications in CDOM-dominated waters.

Characterization of primary hyperparathyroidism based on target organ involvement: An analysis from the Indian PHPT registry.

BACKGROUND: It has been a matter of debate for long time about the existence of two distinct phenotypes of primary hyperparathyroidism (PHPT) predisposed to either renal or skeletal manifestation. OBJECTIVE: To differentiate characteristics of symptomatic PHPT patients based on the presence of skeletal or renal involvement. DESIGN: Retrospective analysis of data from the Indian PHPT registry. PATIENTS: PHPT patients were divided into four discrete groups: asymptomatic, presenting with renal manifestations alone, skeletal manifestations alone, and both skeletal and renal manifestations. MEASUREMENTS: Clinical, biochemical, and tumour weight and histopathological characteristics of these groups were compared. RESULTS: Of the 229 eligible patients, 45 were asymptomatic, 62 had renal manifestations, 55 had skeletal manifestations, and 67 had both skeletal and renal manifestations. Patients with both skeletal and renal manifestations had higher serum calcium levels than those with isolated skeletal involvement [12.5 (11.1-13.7) mg/dL, 11.2 (10.6-12.3) mg/dL, respectively; p < .05]. Serum alkaline phosphatase (AP), plasma parathyroid hormone (PTH) levels, and parathyroid tumour weight were significantly higher in patients with isolated skeletal, and both skeletal and renal manifestations, compared to the other two groups. A preoperative PTH and AP level of 300 pg/mL and 152 U/L, predicted the risk of developing skeletal involvement with sensitivity and specificity of 71%, 70%, and 69%, 67%, respectively. CONCLUSIONS: We observed distinct skeletal and renal phenotypic subgroups among PHPT patients with characteristic biochemical and hormonal patterns with higher parathyroid disease burden in patients with skeletal complications compared to those with isolated renal manifestation.

Metabolic changes in glioblastomas in response to choline kinase inhibition: In vivo MRS in rodent models.

Changes in glioblastoma (GBM) metabolism was investigated in response to JAS239, a choline kinase inhibitor, using MRS. In addition to the inhibition of phosphocholine synthesis, we investigated changes in other key metabolic pathways associated with GBM progression and treatment response. Three syngeneic rodent models of GBM were used: F98 (N = 12) and 9L (N = 8) models in rats and GL261 (N = 10) in mice. Rodents were intracranially injected with GBM cells in the right cortex and tumor growth was monitored using T2 -weighted images. Animals were treated once daily with intraperitoneal injections of 4 mg/kg JAS239 (F98 rats, n = 6; 9L rats, n = 6; GL261 mice, n = 5) or saline (control group, F98 rats, n = 6; 9L rats, n = 2; GL261 mice, n = 5) for five consecutive days. Single voxel spectra were acquired on Days 0 (T0, baseline) and 6 (T6, end of treatment) from the tumor as well as the contralateral normal brain using a PRESS sequence. Changes in metabolite ratios (tCho/tCr, tCho/NAA, mI/tCr, Glx/tCr and (Lip + Lac)/Cr) were used to assess metabolic pathway alterations in response to JAS239. Tumor growth arrest was noted in all models in response to JAS239 treatment compared with saline-treated animals, with a significant reduction (p < 0.05) in the F98 model. A reduction in tCho/tCr was observed with JAS239 treatment in all GBM models, indicating reduced phospholipid metabolism, with the highest reduction in 9L followed by GL261 and F98 tumors. A significant reduction (p < 0.05) in the tCho/NAA ratio was observed in the 9L model. A significant reduction in mI/tCr (p < 0.05) was found in JAS239-treated F98 tumors compared with the saline-treated animals. A non-significant trend of reduction in Glx/tCr was observed only in F98 and 9L tumors. JAS239-treated F98 tumors also showed a significant increase in Lip + Lac (p < 0.05), indicating increased cell death. This study demonstrated the utility of MRS in assessing metabolic changes in GBM in response to choline kinase inhibition.

Determining clinically relevant features in cytometry data using persistent homology.

Cytometry experiments yield high-dimensional point cloud data that is difficult to interpret manually. Boolean gating techniques coupled with comparisons of relative abundances of cellular subsets is the current standard for cytometry data analysis. However, this approach is unable to capture more subtle topological features hidden in data, especially if those features are further masked by data transforms or significant batch effects or donor-to-donor variations in clinical data. We present that persistent homology, a mathematical structure that summarizes the topological features, can distinguish different sources of data, such as from groups of healthy donors or patients, effectively. Analysis of publicly available cytometry data describing non-naïve CD8+ T cells in COVID-19 patients and healthy controls shows that systematic structural differences exist between single cell protein expressions in COVID-19 patients and healthy controls. We identify proteins of interest by a decision-tree based classifier, sample points randomly and compute persistence diagrams from these sampled points. The resulting persistence diagrams identify regions in cytometry datasets of varying density and identify protruded structures such as 'elbows'. We compute Wasserstein distances between these persistence diagrams for random pairs of healthy controls and COVID-19 patients and find that systematic structural differences exist between COVID-19 patients and healthy controls in the expression data for T-bet, Eomes, and Ki-67. Further analysis shows that expression of T-bet and Eomes are significantly downregulated in COVID-19 patient non-naïve CD8+ T cells compared to healthy controls. This counter-intuitive finding may indicate that canonical effector CD8+ T cells are less prevalent in COVID-19 patients than healthy controls. This method is applicable to any cytometry dataset for discovering novel insights through topological data analysis which may be difficult to ascertain otherwise with a standard gating strategy or existing bioinformatic tools.

Risk factors for pulmonary mucormycosis in subjects with diabetes mellitus-A case-control study.

BACKGROUND: Factors associated with pulmonary mucormycosis (PM) among subjects with diabetes mellitus (DM) remain unclear. Following the coronavirus disease (COVID-19)-associated mucormycosis outbreak in India, specific environmental exposures (especially cattle dung exposure) were proposed as possible aetiology. We hypothesized that environmental factors are associated with PM. We compared subjects with DM with (cases) and without PM (controls). METHODS: In this case-control study, for each PM case, we included five unmatched diabetic controls (hospital [n = 2], community [n = 3]) without PM. We collected information on demography, COVID-19 infection, glycated haemoglobin% (HbA1c), the type of house (pucca vs. kutcha) where the participants reside, and other environmental factors. The primary exposure tested was cattle dung exposure (CDE; using cattle dung cakes as fuel or cattle handling). We performed a multivariate logistic regression to explore factors associated with PM and report the association as an adjusted odds ratio (OR) with 95% confidence intervals (CI). RESULTS: We enrolled 39 PM cases and 199 controls (hospital [n = 80], community [n = 119]). CDE (OR 0.68, 95% CI [0.14-3.31]; p = 0.63) was not associated with increased PM in DM. We found male sex (OR 4.07, 95% CI [1.16-14.31]), higher HbA1c (OR 1.51, 95% CI [1.18-16.32]), COVID-19 (OR 28.25, 95% CI [7.02-113.6]) and residence at kutcha house (OR 4.84, 95% CI [1.33-17.52]) associated with PM. CONCLUSION: Cattle dung exposure was not associated with PM in subjects with DM. Instead, male sex, poor glycaemic control, COVID-19 and the type of housing were associated with pulmonary mucormycosis.

Gene expression data classification using topology and machine learning models.

BACKGROUND: Interpretation of high-throughput gene expression data continues to require mathematical tools in data analysis that recognizes the shape of the data in high dimensions. Topological data analysis (TDA) has recently been successful in extracting robust features in several applications dealing with high dimensional constructs. In this work, we utilize some recent developments in TDA to curate gene expression data. Our work differs from the predecessors in two aspects: (1) Traditional TDA pipelines use topological signatures called barcodes to enhance feature vectors which are used for classification. In contrast, this work involves curating relevant features to obtain somewhat better representatives with the help of TDA. This representatives of the entire data facilitates better comprehension of the phenotype labels. (2) Most of the earlier works employ barcodes obtained using topological summaries as fingerprints for the data. Even though they are stable signatures, there exists no direct mapping between the data and said barcodes. RESULTS: The topology relevant curated data that we obtain provides an improvement in shallow learning as well as deep learning based supervised classifications. We further show that the representative cycles we compute have an unsupervised inclination towards phenotype labels. This work thus shows that topological signatures are able to comprehend gene expression levels and classify cohorts accordingly. CONCLUSIONS: In this work, we engender representative persistent cycles to discern the gene expression data. These cycles allow us to directly procure genes entailed in similar processes.

Comparison of Profile of Primary Hyperparathyroidism With and Without Type 2 Diabetes Mellitus: Retrospective Analysis From the Indian Primary Hyperparathyroidism Registry.

OBJECTIVE: To describe the prevalence and compare the clinicobiochemical profile of patients with primary hyperparathyroidism (PHPT) with and without type 2 diabetes mellitus (T2DM). METHODS: We conducted a retrospective observational study wherein the details of patients with PHPT with T2DM (PHPT-T2DM) and without T2DM were retrieved from the Indian PHPT Registry (www.indianphptregistry.com) between 2005 and 2019. We compared the clinical, biochemical, and postoperative findings of patients with PHPT-T2DM with age-, sex-, and body mass index-matched patients with PHPT without T2DM (in 1:2 ratio). RESULTS: Of the 464 patients with PHPT, 54 (11.6%) had T2DM. We observed an increase in the prevalence of PHPT-T2DM cases over time; only 7 (7.1%) of the total patients with PHPT had T2DM between 2005 and 2009 that increased to 31 (12.8%) in the last half decade (2015-2019). Patients with PHPT-T2DM had a significantly lower prevalence of nephrolithiasis (18.5% vs 36.1%, respectively; P = .03) and a higher prevalence of pancreatitis (22.2% vs 5.6%, respectively; P = .007) than those without T2DM. Furthermore, intact parathyroid hormone (203 pg/mL [139.8-437.3 pg/mL] vs 285 pg/mL [166-692 pg/mL], respectively; P = .04) and serum creatinine (0.90 mg/dL [0.67-1.25 mg/dL] vs 1.10 mg/dL [0.73-1.68 mg/dL], respectively; P = .03) levels were significantly lower in patients with PHPT-T2DM than those without T2DM. Also, tumor weight tended to be lower in patients with PHPT-T2DM than in the non-T2DM counterparts (1.05 g [0.5-2.93 g] vs 2.16 g [0.81-7.0 g], respectively; P = .06). CONCLUSION: The prevalence of T2DM in Asian Indians with PHPT is 11.6%. Patients with PHPT-T2DM are characterized by a higher prevalence of pancreatitis, a lower prevalence of nephrolithiasis, and lower levels of intact parathyroid hormone/creatinine. Part of the clinical picture can possibly be explained by early detection of PHPT in patients with T2DM consequent to more frequent screening.

Progressive rise in the prevalence of asymptomatic primary hyperparathyroidism in India: Data from PHPT registry.

INTRODUCTION: Primary hyperparathyroidism (PHPT), a third common endocrine disorder, varies from asymptomatic disease, mostly seen in the West where routine biochemical screening is practiced, to the classical symptomatic disease mostly seen in the Eastern countries. We aimed to compare the demographic, clinical, biochemical measurements in patients with asymptomatic and symptomatic PHPT from the Indian PHPT registry. MATERIAL AND METHODS: Data of PHPT patients from the last 25 years (1995-2019) were analyzed for demographic, clinical presentation and biochemical measurements, and compared these characteristics between asymptomatic and symptomatic PHPT patients. RESULTS: Of the 554 patients, 54 (10%) patients had asymptomatic PHPT. There was a sharp rise in the proportion of asymptomatic PHPT patients of 3% in the first decade to 13% in the second decade of the century (p = 0.003). Patients with asymptomatic PHPT were significantly older (50 vs. 42 years; p < 0.0001) and had higher mean body mass index (27.8 vs. 23.5 kg/m2; p < 0.0001) compared to the symptomatic PHPT group. In addition, asymptomatic PHPT patients had significantly lower median plasma iPTH (180 vs. 370 pg/mL; p < 0.0001), serum alkaline phosphatase (119 vs. 172 IU/L; p < 0.0001), and parathyroid adenoma weight (1.0 vs. 2.62 g; p = 0.006) compared to the symptomatic PHPT group. CONCLUSION: Although symptomatic PHPT is still most prevalent (> 90%) in India with higher indices of the disease and tumor weights, there is a progressive rise in the prevalence of asymptomatic PHPT patients in the last decade. Improvements in calcium and vitamin D nutrition might account for this change as in the Western series.

Parathyroid Carcinoma: An Experience from the Indian Primary Hyperparathyroidism Registry.

OBJECTIVE: To describe the details of widely invasive parathyroid carcinoma (WIPC) patients admitted in the Endocrinology department of our institute during the last 22 years and to compare their clinical, biochemical, and hormonal profile with minimally invasive parathyroid carcinoma (MIPC) and sporadic parathyroid adenoma patients. METHODS: This is a retrospective analysis of data from the Indian primary hyperparathyroidism registry. RESULTS: Of the 547 primary hyperparathyroidism patients in the registry, 5 (2 men and 3 women) had WIPC (0.9%) and 7 (1 man and 6 women) had MIPC (1.3%), with median ages of 45 (interquartile range, 41-51) years and 47 (interquartile range, 28-48) years, respectively. Among the patients with WIPC, renal manifestations were present in 5 patients, skeletal manifestations in 4 patients, and palpable neck masses in 4 patients. Three patients had distant metastases and 2 had cervical lymph node involvement. All 5 patients had surgical resection of their cancers, with persistent disease in 4 patients, but all patients died within 2 years after surgery. One patient with MIPC had a palpable parathyroid nodule; none had lymph nodal or distant metastases. None of the patients with MIPC died during the median follow-up of 18 (interquartile range, 12-18) months. Patients with WIPC had significantly higher serum calcium level compared with sporadic parathyroid adenoma patients with skeletal and renal manifestations. CONCLUSION: Accurate histopathologic classification of parathyroid carcinoma is important as WIPC is associated with a more aggressive clinical course and a higher risk of mortality than MIPC.

Minimally invasive parathyroid carcinoma-A missing entity between parathyroid adenoma and carcinoma: Scintigraphic and histological features.

PURPOSE: Minimally invasive parathyroid carcinoma (MIPC) is clinically and biochemically comparable with parathyroid adenoma (PA) though histopathologically differ from PA. MIPC is an intermediate of PA and parathyroid carcinoma (PC). In literature, there is no definite criterion to diagnose MIPC. Our aim was to evaluate and characterize the imaging and biochemical parameters with histological characteristics of MIPC. METHODOLOGY: Ten patients with MIPC were recruited from (single centre) Indian PHPT registry (www.indianphptregistry.com) from January 2014 to July 2018. Clinical, biochemical, imaging and histological features of MIPC patients were reviewed. RESULTS: The mean age of MIPC patients (n = 10; 3 males) was 39.9 ± 11.3 years (range: 17-50). All patients had an elevated preoperative parathyroid hormone (iPTH) level ranging from 427 to 2138 pg/mL (median: 1328). MIBI scan showed intensely avid and enlarged parathyroid tumours in all patients; LIPT in 6, RIPT in 3 and ectopic mediastinal in 1 with mean size of the tumours was 2.8 ± 1.1 cm. The mean of maximum standardized uptake value (SUVmax) of MIPC in F-18 fluorocholine PET/CT was 6.7 ± 1.1 (range 6.0-8.3). The mean tumour weight was 12 ± 9.5 g (range: 1.09-28). All MIPC patients had identified capsular invasion in 80% and vascular invasion in 50% only but there was no local invasion, lymph nodal or distant metastasis. The mean Ki-67 labelling index was 3.2 ± 2.7 (range 1.1-10). CONCLUSION: The study concluded that MIPC patients are less aggressive (on the basis of imaging and histopathological findings) and should be differentiated from parathyroid adenoma and carcinoma.

Cesium Bismuth Iodide Solar Cells from Systematic Molar Ratio Variation of CsI and BiI3.

Metal halide compounds with photovoltaic properties prepared from solution have received increased attention for utilization in solar cells. In this work, low-toxicity cesium bismuth iodides are synthesized from solution, and their photovoltaic and optical properties as well as electronic and crystal structures are investigated. The X-ray diffraction patterns reveal that a CsI/BiI3 precursor ratio of 1.5:1 can convert pure rhombohedral BiI3 to pure hexagonal Cs3Bi2I9, but any ratio intermediate of this stoichiometry and pure BiI3 yields a mixture containing the two crystalline phases Cs3Bi2I9 and BiI3, with their relative fraction depending on the CsI/BiI3 ratio. Solar cells from the series of compounds are characterized, showing the highest efficiency for the compounds with a mixture of the two structures. The energies of the valence band edge were estimated using hard and soft X-ray photoelectron spectroscopy for more bulk and surface electronic properties, respectively. On the basis of these measurements, together with UV-vis-near-IR spectrophotometry, measuring the band gap, and Kelvin probe measurements for estimating the work function, an approximate energy diagram has been compiled clarifying the relationship between the positions of the valence and conduction band edges and the Fermi level.

Switching of Trp-214 intrinsic rotamer population in human serum albumin: An insight into the aftermath of embracing therapeutic bioorganic luminophore azapodophyllotoxin into sudlow site I.

Human serum albumin is perceived to be the most abundant protein in human blood plasma and functions as a major carrier of different enzymes and drugs inside human body. The present article puts in an effort to demonstrate the attitude adopted by human serum albumin towards a potential therapeutic luminophore 4-(2-Hydroxyethyl)-10-phenyl-3,4,6,7,8,10-hexahydro-1H-cyclopenta[g]furo[3,4-b]quinoline-1-one (HPFQ). HPFQ is a prodigy from azapodophyllotoxin class of compounds, which have been synthesized from the perspective of improved bioactivity than its prologue podophyllotoxins. While, HPFQ has proved to be highly bioactive against most cancer cell lines with best GI50 values of <0.1 µM for a major number of cell lines; it also showed terrific fluorescent properties throughout the polarity scale, worthy of a promising imaging agent. The binding mechanism of HPFQ with HSA has been established by combining in vitro spectroscopic techniques, in silico molecular docking and induced fit docking (IFD). The competitive site-binding studies demonstrated that the otherwise anion-receptor sudlow site I of HSA nurtures neutral HPFQ with prudent affinity (Binding constant, Kb = 0.74 × 105 M-1). The time-resolve fluorescence studies reveal an appreciable reduction in HSA average radiative lifetime against an increase in HPFQ concentration and provided evidence for Forster's resonance energy transfer (FRET) being responsible for the dominant quenching mechanism, escorted by minor structural deformations in the backbone of protein structure. HPFQ institutes itself near Trp-214 within protein matrix, and subsequently the "hydrophobic amino acids" dominated cybotactic environment of Trp-214 experiences a reduction in the micropolarity. The allosteric modulation triggered by the stronger association of HPFQ with HSA leads towards minor deformation in secondary structure of protein. Sudlow site I of HSA proficiently embraces a favourable conformation like malleable dough to furnish space for arriving bioactive HPFQ molecule. HPFQ is also believed to administer the conformational regulation in HSA domain by affecting inter-conversion of HSA rotamers, which may prove to be an enlightening area to decode the preferable interaction between them. The juxtaposed spectroscopic research described herein is expected to embolden design of azapodophyllotoxin based anti-proliferative clinical agents for efficient in vivo bio-distribution employing HSA-centred drug delivery and administration systems.

Association of Pseudohypoparathyroidism and Autoimmune Polyglandular Syndrome: Causal or Coincidental?

Pseudohypoparathyroidism (PHP) is a state of parathyroid hormone resistance and is characterised by low serum calcium, and elevated serum phosphate and parathyroid hormone level. Association of PHP with autoimmune disorders is rare and seldom reported in the literature. Here we describe a case of PHP who subsequently developed multiple autoimmune disorders (type 3 polyglandular autoimmune syndrome), which has not been reported so far.

Evolution of the Local Structure within Chromophoric Mn-O5 Trigonal Bipyramids in YMn1- xIn xO3 with Composition.

We have investigated the local environment around Mn3+ and In3+ ions in YMn1- xIn xO3 chromophores to understand the origin of the intense blue color for small values of x in these solid solutions. While X-ray diffraction results provide an average description of the trigonal bipyramidal (TBP) units about Mn/In atoms with five oxygens surrounding the cation, the X-ray absorption near edge structure (XANES) as well as extended X-ray absorption fine structure (EXAFS) of these materials clearly suggest the presence of two different TBP environments, one of which is similar to MnO5 TBP in YMnO3. EXAFS in conjunction with first-principles calculations show that replacing larger In3+ ions by smaller Mn3+ ones additionally gives rise to another TBP strongly distorted along the axial direction, expanding one of the axial Mn-O bonds by ∼11%. The relative fraction of these two environments changes in close agreement with the global stoichiometry with the elongated TBP, therefore, being dominant in the regime of the low Mn content. This local structural difference is responsible for the intense, but relatively narrow, absorption feature in the red-yellow region of the absorption spectrum, and hence YMn1- xIn xO3 appears blue for small Mn dopings. This distortion is relatively less abundant in Mn-rich compositions, and therefore, such compositions appear black, controlled by the wide absorption feature of the trigonal bipyramid coordination with Mn-O bond lengths that are essentially the same as those in YMnO3, covering the entire visible range. The chromophore properties are, thus, governed by the ratio of these two MnO5 TBP environments, one with a characteristic optical absorption giving it a blue color and the other absorbing over the entire visible range.

PRIMARY HYPERPARATHYROIDISM IN THE YOUNG: COMPARISON WITH ADULT PRIMARY HYPERPARATHYROIDISM.

OBJECTIVE: Primary hyperparathyroidism (PHPT) is relatively common among adults but rarely encountered in children and adolescents. According to the western literature, young PHPT is different from adult PHPT and is associated with more severe hypercalcemia. PHPT in the adult Indian population is different from its western counterpart. Here we present the clinical, biochemical, and surgical characteristics of young patients with PHPT treated at our tertiary care center. METHODS: PHPT patients were divided into adult (≥25 years) and young (<25 years) groups. The clinical, biochemical, hormonal, and histopathologic characteristics and treatment outcomes in the groups were compared. RESULTS: Out of 358 patients, 47 patients were young and 311 patients were adults. The mean ages of the groups were 19 ± 4 and 45 ± 12 years, respectively. The corresponding female-to-male ratios were 1.24:1 and 3.38:1 ( P<.05). The nature and frequency of presenting symptoms were comparable between the 2 groups. The most common symptom in young patients with PHPT was bone pain and was not significantly different from adults (57% vs. 61%, respectively). The most common symptom in adult PHPT was fatigue, which was also not significantly different from young patients (63% vs. 53%, respectively), The serum calcium, phosphate, 25-hydroxyvitamin D levels; alkaline phosphatase Z-score; and parathyroid hormone levels were comparable between the 2 groups. Parathyroid adenoma was the most common histopathologic finding, while hyperplasia was rare in both groups. CONCLUSION: We observed that young PHPT is not markedly different from its adult counterpart in an Indian population. ABBREVIATIONS: ALP = alkaline phosphatase; Ca = calcium; Cr = creatinine; iPTH = intact parathyroid hormone; 25(OH)D = 25-hydroxyvitamin D; P = phosphate; PHPT = primary hyperparathyroidism; PTH = parathyroid hormone; RR = reference range; 99mTc sestamibi = technetium sestamibi; USG = ultrasonography.

Frequency & predictors of pancreatitis in symptomatic primary hyperparathyroidism.

BACKGROUND & OBJECTIVES: The frequency and predictors of pancreatitis in primary hyperparathyroidism (PHPT) are not well understood. The objective of the present study was to evaluate the frequency of pancreatitis in patients with PHPT and its association with clinical and biochemical parameters of the disease. METHODS: In this retrospective study all consecutive patients with PHPT registered in the PHPT registry (www.indianphptregistry.com) from the year 2004 to 2013 were included. The clinical, biochemical and radiological parameters related to pancreatitis were evaluated in histologically proven PHPT patients. RESULTS: A total of 218 patients (63 men; mean age: 40.6±14.4 yr) underwent surgery for PHPT during the study. Pancreatitis occurred in 35 [16%, 18 acute and 17 chronic pancreatitis (CP)] patients and male:female ratio was 1:0.94. Skeletal manifestations were seen less frequently in PHPT with pancreatitis as compared to that of PHPT without pancreatitis. PHPT with pancreatitis had significantly higher serum calcium (12.4±2.0 vs. 11.7±1.5 mg/dl, P <0.05) in comparison to PHPT without pancreatitis. PHPT with acute pancreatitis (AP) had higher serum calcium (P <0.05) and parathyroid hormone (PTH) (P <0.05) levels than PHPT with CP. Curative parathyroidectomy improved the symptoms associated with pancreatitis as there was no recurrence in AP group, whereas recurrence was observed only in about 10 per cent patients of the CP group. INTERPRETATION & CONCLUSIONS: Pancreatitis was observed in 16 per cent of PHPT patients with male predominance in the study population. No recurrence of AP was observed after curative surgery. It may be proposed that serum amylase with calcium and PTH should be measured in all patients of PHPT with pain abdomen to rule out pancreatitis.

Extra-Pituitary Birth Defects May Predict Diagnosis of Congenital Hypopituitarism in a Short Child.

BACKGROUND: Extra-pituitary birth defect (EPBD) in children with congenital hypopituitarism is largely unknown. OBJECTIVE: The study aims to evaluate the incidence and pattern of EPBD in children with congenital hypopituitarism and to evaluate whether it can serve as a clue to diagnose this condition. PATIENTS AND METHODS: Retrospective analysis of hospital record of patients of short stature due to various etiology from which patients with congenital hypopituitarism with age ≥18 years were recruited for the analysis. Clinical, hormonal, radiological and ocular electrophysiological studies were done in all patients and all EPBD were noted. RESULTS: Twenty seven patients (79%) had multiple pituitary hormone deficiency (MPHD) of which growth hormone was universal followed by gonadotropin (62%), TSH (59%), ACTH (44%) and prolactin (12%). Nineteen patients (56%) had multiple EPBD in various combinations. Twenty three ocular abnormalities were present in 12 patients (35%). Nine patients (26%) had other associated EPBD along with ocular abnormalities while 3 had ocular abnormalities without any other associated birth defect. Skeletal defects were present in 10 patients (29.5%). On the contrary, 5 patients in the EPBD group had total 15 visual defects. The most common abnormality of the visual system were abnormal visual evoke response (VER, 18%), followed by strabismus (15%), visual acuity (VA, 12%), electroretinogram (ERG) and electrooculogram (EOG) 8% each and visual field defect 6%. There was a trend towards early age at presentation with EPBD. CONCLUSIONS: Presence of EPBD in a short child is a sensitive marker to diagnose congenital hypopituitarism. Subtle abnormalities of visual pathway without absent septum pellucidum or midline brain defects were common.

Efficient solid-state light-emitting CuCdS nanocrystals synthesized in air.

Semiconductor nanocrystals (NCs) possess high photoluminescence (PL) typically in the solution phase. In contrary, PL rapidly quenches in the solid state. Efficient solid state luminescence can be achieved by inducing a large Stokes shift. Here we report on a novel synthesis of compositionally controlled CuCdS NCs in air avoiding the usual complexity of using inert atmosphere. These NCs show long-range color tunability over the entire visible range with a remarkable Stokes shift up to about 1.25 eV. Overcoating the NCs leads to a high solid-state PL quantum yield (QY) of ca. 55% measured by using an integrating sphere. Unique charge carrier recombination mechanisms have been recognized from the NCs, which are correlated to the internal NC structure probed by using extended X-ray absorption fine structure (EXAFS) spectroscopy. EXAFS measurements show a Cu-rich surface and Cd-rich interior with 46% Cu(I) being randomly distributed within 84% of the NC volume creating additional transition states for PL. Color-tunable solid-state luminescence remains stable in air enabling fabrication of light-emitting diodes (LEDs).