Boron carbide thin film surface characterization after graphitic carbon removal using low-pressure oxygen gas RF plasma.

B 4 C-coated thin film mirrors are used in high brilliance synchrotron and x-ray free electron laser beamlines due to their low absorption coefficient and high thermal stability. As in the case of gold, platinum, and other thin film mirrors, B 4 C-coated mirrors also are affected due to synchrotron radiation-induced carbon contaminations in beamlines. In the present study, a graphitic carbon (C) layer deposited on top of boron carbide (B x C) thin film surface is removed by five successive oxygen radio frequency (RF) plasma exposures (RF power, 10 W; O 2 flow, 30 sccm; exposure time, 10 min each). Before and after the carbon layer removal, structural and compositional properties of the B x C/C bilayer are characterized by soft x-ray reflectivity, x-ray photoelectron spectroscopy, grazing angle x-ray diffraction, and Raman spectroscopy techniques. Characterization results reveal that in the first four exposures the carbon layer thickness decreases continuously without affecting the B x C layer properties; however, in the fifth exposure, the carbon layer is completely removed along with a partial etching of the B x C layer too.

Influence of spin orbit splitting and satellite transitions on nickel soft X-ray optical properties near its L2,3 absorption edge region.

Transition elements exhibit strong correlations and configuration interactions between core and valence excited states, which give rise to different excitations inside materials. Nickel exhibits satellite features in its emission and absorption spectra. Effects of such transitions on the optical constants of nickel have not been reported earlier and the available database of Henke et al. does not represent such fine features. In this study, the optical behaviour of ion beam sputter deposited Ni thin film near the L2,3-edge region is investigated using reflection spectroscopy techniques, and distinct signatures of various transitions are observed. The soft X-ray reflectivity measurements in the 500-1500 eV photon energy region are performed using the soft X-ray reflectivity beamline at the Indus-2 synchrotron radiation source. Kramers-Kronig analysis of the measured reflectivity data exhibit features corresponding to spin orbital splitting and satellite transitions in the real and imaginary part of the refractive index (refraction and absorption spectra). Details of fine features observed in the optical spectra are discussed. To the best of our knowledge, this is the first study reporting fine features in the measured optical spectra of Ni near its L2,3-edge region.

Oxidative stress contributes to cerebral metabolomic profile changes in animal model of blast-induced traumatic brain injury.

INTRODUCTION: Blast-induced neurotrauma (BINT) has been recognized as the common mode of traumatic brain injury amongst military and civilian personnel due to an increased insurgent activity domestically and abroad. Previous studies from this laboratory have identified three major pathological events following BINT which include blood brain barrier disruption the earliest event, followed by oxidative stress and neuroinflammation as secondary events occurring a few hours following blast. OBJECTIVES: Our recent studies have also identified an increase in oxidative stress mediated by the activation of superoxide producing enzyme NADPH oxidase (NOX) in different brain regions at varying levels with neurons displaying higher oxidative stress (NOX activation) compared to any other neural cell. Since neurons have higher energy demands in brain and are more prone to oxidative damage, this study evaluated the effect of oxidative stress on blast-blast induced changes in metabolomics profiles in different brain regions. METHODS: Animals were exposed to mild/moderate blast injury (180 kPa) and examined the metabolites of energy metabolism, amino acid metabolism as well as the profiles of plasma membrane metabolites in different brain regions at different time points (24 h, 3 day and 7 day) after blast using 1H NMR spectroscopy. Effect of apocynin, an inhibitor of superoxide producing enzyme NADPH oxidase on cerebral metabalomics profiles was also examined. RESULTS: Several metabolomic profile changes were observed in frontal cortex and hippocampus with concomitant decrease in energy metabolism. In addition, glutamate/glutamine and other amino acid metabolism as well as metabolites involved in plasma membrane integrity were also altered. Hippocampus appears metabolically more vulnerable than the frontal cortex. A post-treatment of animals with apocynin, an inhibitor of NOX activation significantly prevented the changes in metabolite profiles. CONCLUSION: Together these studies indicate that blast injury reduces both cerebral energy and neurotransmitter amino acid metabolism and that oxidative stress contributes to these processes. Thus, strategies aimed at reducing oxidative stress can have a therapeutic benefit in mitigating metabolic changes following BINT.

Refurbishment of an Au-coated toroidal mirror by capacitively coupled RF plasma discharge.

Deposition of synchrotron-radiation-induced carbon contamination on beamline optics causes their performance to deteriorate, especially near the carbon K edge. The photon flux losses due to carbon contamination have spurred researchers to search for a suitable decontamination technique to restore the optical surface and retain its performance. Several in situ and ex situ refurbishing strategies for beamline optics are still under development to solve this serious issue. In this work, the carbon contamination is removed from a large (340 mm × 60 mm) Au-coated toroidal mirror surface using a capacitively coupled low-pressure RF plasma. Before and after RF plasma cleaning, the mirror was characterized by Raman spectroscopy, soft X-ray reflectivity (SXR) and atomic force microscopy (AFM) techniques. The Raman spectra of the contaminated mirror clearly show the G (1575-1590 cm-1) and D (1362-1380 cm-1) bands of graphitic carbon. The SXR curve of the contaminated mirror shows a clear dip near the critical momentum transfer of carbon, indicating the presence of carbon contamination on the mirror surface. This dip disappears after removal of the contamination layer by RF plasma exposure. A decrease in the intensities of the CO bands is also observed by optical emission spectrometry during plasma exposure. The AFM and SXR results suggest that the root-mean-square (r.m.s.) roughness of the mirror surface does not increase after plasma exposure.

Porous carbons derived from polyethylene terephthalate (PET) waste for CO2 capture studies.

Oxygen augmented carbon adsorbent has been developed using polyethylene terephthalate (PET) waste by first carbonizing at different temperatures (500-800 °C) and then chemically activating using different ratios of KOH: PET (mass ratio 1 to 4). The textural characterization divulges the effect of activation in terms of the development of the high surface area and micropore volume of 1690 m2 g-1 and 0.78 cm3 g-1 respectively, for the optimum sample (PET-3-700). Elemental analysis of PET-3-700 illustrates the presence of 34.33% oxygen and XPS results confirmed the occurrence of oxygen moieties which enhance the basicity of the adsorbent and promote CO2 capture. The CO2 adsorption capacity of prepared carbons was determined thermogravimetrically under dynamic conditions, at different concentrations of CO2 (6-100%) and temperatures. The maximum CO2 uptake capacity of 2.31 mmol g-1 was exhibited by PET-3-700 at an adsorption temperature of 30 °C under 100% pure CO2 flow. Four adsorption-desorption cycles corroborate almost complete regenerability of the prepared adsorbent. Adsorption kinetics at all adsorption conditions was described best by fractional order kinetic model. Freundlich isotherm fit indicates the surface of adsorbent being heterogeneous and low values of isosteric heat shows physisorption behavior of the process. Negative values of thermodynamic parameters indicate exothermic and feasible nature of adsorption process.

Evolution of the α-Subunit of Na/K-ATPase from Paramecium to Homo sapiens: Invariance of Transmembrane Helix Topology.

Na/K-ATPase is a key plasma membrane enzyme involved in cell signaling, volume regulation, and maintenance of electrochemical gradients. The α-subunit, central to these functions, belongs to a large family of P-type ATPases. Differences in transmembrane (TM) helix topology, sequence homology, helix-helix contacts, cell signaling, and protein domains of Na/K-ATPase α-subunit were compared in fungi (Beauveria), unicellular organisms (Paramecia), primitive multicellular organisms (Hydra), and vertebrates (Xenopus, Homo sapiens), and correlated with evolution of physiological functions in the α-subunit. All α-subunits are of similar length, with groupings of four and six helices in the N- and C-terminal regions, respectively. Minimal homology was seen for protein domain patterns in Paramecium and Hydra, with high correlation between Hydra and vertebrates. Paramecium α-subunits display extensive disorder, with minimal helix contacts. Increases in helix contacts in Hydra approached vertebrates. Protein motifs known to be associated with membrane lipid rafts and cell signaling reveal significant positional shifts between Paramecium and Hydra vulgaris, indicating that regional membrane fluidity changes occur during evolution. Putative steroid binding sites overlapping TM-3 occurred in all species. Sites associated with G-protein-receptor stimulation occur both in vertebrates and amphibia but not in Hydra or Paramecia. The C-terminus moiety "KETYY," necessary for the Na(+) activation of pump phosphorylation, is not present in unicellular species indicating the absence of classical Na(+)/K(+)-pumps. The basic protein topology evolved earliest, followed by increases in protein domains and ordered helical arrays, correlated with appearance of α-subunit regions known to involve cell signaling, membrane recycling, and ion channel formation.

The role of receptor topology in the vitamin D3 uptake and Ca(2+) response systems.

The steroid hormone, vitamin D3, regulates gene transcription via at least two receptors and initiates putative rapid response systems at the plasma membrane. The vitamin D receptor (VDR) binds vitamin D3 and a second receptor, importin-4, imports the VDR-vitamin D3 complex into the nucleus via nuclear pores. Here we present evidence that the Homo sapiens VDR homodimer contains two transmembrane (TM) helices ((327)E - D(342)), two TM "half-helix" ((264)K N(276)), one or more large channels, and 16 cholesterol binding (CRAC/CARC) domains. The importin-4 monomer exhibits 3 pore-lining regions ((226)E - L(251); (768)V - G(783); (876)S - A(891)) and 16 CRAC/CARC domains. The MEMSAT algorithm indicates that VDR and importin-4 may not be restricted to cytoplasm and nucleus. VDR homodimer TM helix-topology predicts insertion into the plasma membrane, with two 84 residue C-terminal regions being extracellular. Similarly, MEMSAT predicts importin-4 insertion into the plasma membrane with 226 residue extracellular N-terminal regions and 96 residue C-terminal extracellular loops; with the pore-lining regions contributing gated Ca(2+) channels. The PoreWalker algorithm indicates that, of the 427 residues in each VDR monomer, 91 line the largest channel, including two vitamin D3 binding sites and residues from both the TM helix and "half-helix". Cholesterol-binding domains also extend into the channel within the ligand binding region. Programmed changes in bound cholesterol may regulate both membrane Ca(2+) response systems and vitamin D3 uptake as well as receptor internalization by the endomembrane system culminating in uptake of the vitamin D3-VDR-importin-4 complex into the nucleus.

Herbicide options for effective weed management in dry direct-seeded rice under scented rice-wheat rotation of western Indo-Gangetic Plains.

Farmers' participatory field trials were conducted at Madhuban, and Taraori, the two participatory experimental sites/locations of the Cereal Systems Initiative for South Asia (CSISA), a collaborative project of IRRI and CIMMYT in Karnal district of Haryana, India, during Kharif (wet season) 2010 and 2011. This research aimed to evaluate preemergence (PRE) and postemergence (POST) herbicides for providing feasible and economically viable weed management options to farmers for predominant scented rice varieties. Treatments with pendimethalin PRE fb bispyribac-sodium + azimsulfuron POST had lower weed biomass at 45 days after sowing (DAS). At Madhuban, highest grain yield of scented basmati rice (3.43 t ha-1) was recorded with the sequential application of pendimethalin PRE fb bispyribac-sodium + azimsulfuron POST. However, at Taraori, yields were similar with pendimethalin or oxadiargyl PRE fb bispyribac-sodium and/or azimsulfuron POST. Applying oxadiargyl by mixing with sand onto flooded field was less effective than spray applications in non-flooded field. The benefit-cost ratio of rice crop was higher with herbicide treatments at both sites as compared with the non-treated weed-free check except single PRE and POST applications and sequential application of oxadiargyl PRE fb oxadiargyl PRE. In a separate experiment conducted at Nagla and Taraori sites, scented rice cultivars' ('CSR 30' and 'Pusa 1121') tolerance to three rates of azimsulfuron (15, 25, and 35 g ai ha-1) was evaluated over two years (2010 and 2011). CSR 30 (superfine, scented) was more sensitive to higher rates (35 g ai ha-1) of azimsulfuron as compared to Pusa 1121 (fine, scented). Crop injuries were 8 and 28% in case of CSR 30; 5 and 15% in Pusa 1121 when applied with azimsulfuron 25 and 35 g ai ha-1, respectively. Azimsulfuron applied at 35 g ai ha-1 reduced yield in both cultivars but in CSR 30 yield reduction was twofold (11.5%) as that of Pusa 1121 (5.2%).

The pore-lining regions in cytochrome c oxidases: A computational analysis of caveolin, cholesterol and transmembrane helix contributions to proton movement.

Cytochrome c oxidase (CcO) is the terminal enzyme in the electron transfer chain. CcO catalyzes a four electron reduction of O2 to water at a catalytic site formed by high-spin heme (a3) and copper atoms (CuB). While it is recognized that proton movement is coupled to oxygen reduction, the proton channel(s) have not been well defined. Using computational methods developed to study protein topology, membrane channels and 3D packing arrangements within transmembrane (TM) helix arrays, we find that subunit-1 (COX-1), subunit-2 (COX-2) and subunit-3 (COX-3) contribute 139, 46 and 25 residues, respectively, to channel formation between the mitochondrial matrix and intermembrane space. Nine of 12 TM helices in COX-1, both helices in COX-2 and 5 of the 6 TM helices in COX-3 are pore-lining regions (possible channel formers). Heme a3 and the CuB sites (as well as the CuA center of COX-2) are located within the channel that includes TM-6, TM-7, TM-10 and TM-11 of COX-1 and are associated with multiple cholesterol and caveolin-binding (CB) motifs. Sequence analysis identifies five CB motifs within COX-1, two within COX-2 and four within COX-3; each caveolin containing a pore-lining helix C-terminal to a TM helix-turn-helix. Channel formation involves interaction between multiple pore-lining regions within protein subunits and/or dimers. PoreWalker analysis lends support to the D-channel model of proton translocation. Under physiological conditions, caveolins may introduce channel formers juxtaposed to those in COX-1, COX-2 and COX-3, which together with cholesterol may form channel(s) essential for proton translocation through the inner mitochondrial membrane.

Computational analysis of the extracellular domain of the Ca²âº-sensing receptor: an alternate model for the Ca²âº sensing region.

The extracellular Ca(2+) sensing receptor (CaSR) belongs to Class C G-protein-coupled receptors (GPCRs) which include receptors for amino acids, γ-aminobutyric acid and glutamate neurotransmitters. CaSR has been described as having an extended sequence containing a Ca(2+) binding pocket within an extracellular amino (N)-terminal domain, called a Venus Fly Trap (VFT) module. CaSR is thought to consist of three domains: 1) a Ca(2+-)sensory domain, 2) a region containing 7 transmembrane (TM) helices, and 3) a carboxy (C)-terminal tail. We find that SPOCTOPUS (a combination of hidden Markov models and artificial neural networks) predicts that Homo sapiens CaSR contains two additional TM helices ((190)D - G(210); (262)S-E(282)), with the second TM helix containing a pore-lining region ((265)K - I(280)). This predicts that the putative Ca(2+) sensory domain is within an extracellular loop, N-terminal to the highly conserved heptahelical bundle. This loop contains both the cysteine-rich domain ((537)V - C(598)) and a 14 residue "linker" sequence ((599)I - F(612)) thought to support signal transmission to the heptahelical bundle. Thus domain 1 may contain a 189 residue N-terminal extracellular region followed successively by TM-1, a short intracellular loop, TM-2 and a 329 residue extracellular loop; rather than the proposed 620 residue VFT module based on crystallography of the N-terminal region of mGluR1. Since the topologies of the two proteins differ, the published CaSR VFT model is questionable. CaSR also contains multiple caveolin-binding motifs and cholesterol-binding (CRAC/CARC) domains, facilitating localization to plasma membrane lipid rafts. Ion sensing may involve combination of pore-lining regions from CaSR dimers and CaSR-bound caveolins to form ion channels capable of monitoring ionized Ca(2+) levels.

Phytase production through response surface methodology and molecular characterization of Aspergillus fumigatus NF191.

Phytase play an important role in phytic acid catalysis that act as a food inhibitor in cereals. Here, we isolated high phytase producing isolates NF191 closely related to Aspergillus fumigatus sp. from piggery soil. DNA was isolated from the fungal culture and amplified the ITS region using ITS1 and ITS4 primer using PCR. The 400-900 bp amplicon was gel eluted and subjected to sequencing. The sequencing results were assembled and compared with NCBI data base which showed the 99% identity of Aspergillus fumigatus. Different carbon sources viz., fructose, galactose, lactose, dextrose, sucrose, maltose and different nitrogen sources (organic & inorganic) NH4Cl, NH4NO3, (NH4)2SO4, KNO3, NaNO3, urea, yeast extract, peptone, beef extract were tested for optimal production. The 0.3% dextrose, 0.5% NH4NO3 and 96 h incubation time showed the best production and enzyme activity at 45 degrees C incubation temperature. The selected parameters, dextrose, ammonium sulphate and incubation time, when employed with statistical optimization approach involving response surface optimization using Box Behnken Design, gave a 1.3 fold increase in phytase production compared to unoptimized condition.

Relevance of physiological efficiency in wheat grain quality and the prospects of improvement.

Released and pre-released bread wheat varieties evaluated in national wheat programme of India (503 genotypes) during 2005-14 under different environments were examined for the role of physiological parameters in grain quality. Genotypes with slow plant height growth but faster rate of grain filling enhanced protein content. Plants where growth in height and grain development was slow, grains were hard, provided proportionate vegetative growth phase is longer. Steady grain growth rate benefited gluten strength and gluten quality. Irrespective of total crop duration, longer reproductive phase was an effective indicator of higher flour recovery and test weight. Magnitude and significance of morphological attributes in grain quality was almost similar to that of physiological processes, therefore prospects of utilizing these field traits were examined to enhance grain properties. Early heading and longer grain filling was effective to increase test weight whereas delayed heading and shorter plant height enhanced protein content. Bold grains hampered grain hardness and delayed heading added more bran in the flour. Genotypes with poor grain bearing and quick grain ripening had lower sedimentation value. Instead of protein, it was wet gluten which expressed negative association with yield. To improvise gluten quality, extended reproductive phase but with less grain weight was helpful. Contribution of longer post-anthesis period was observed crucial in flour recovery. These useful simple field expressions can be deployed to uplift quality of wheat grains.

Gluten characteristics imparting bread quality in wheats differing for high molecular weight glutenin subunits at Glu D1 locus.

High yielding genotypes differing for high molecular weight glutenin subunits at Glu D1 locus in national wheat programme of India were examined for bread loaf volume, gluten and protein contents, gluten strength, gluten index and protein-gluten ratio. Number of superior bread quality genotypes in four agro-climatically diverse zones of Indian plains was comparable in both categories of wheat i.e., 5 + 10 and 2 + 12. There wasn't any difference in average bread loaf volume and grain protein content either. 5 + 10 wheats showed better gluten strength and their gluten quality was also superior in the zones where protein content was high. 2 + 10 wheats exerted more gluten due to better protein-gluten ratio. Good bread making in 5 + 10 was derived by better gluten strength and also gluten quality in certain regions but bread quality in 2 + 12 wheats was channelized through higher gluten content as they were more efficient in extracting gluten from per unit protein. Difference in route to bread quality was apparent as gluten content and gluten strength were the key gluten attributes in 5 + 10 whereas protein content and gluten index were prominent in 2 + 12 types. Unlike 2 + 12, there was a ceiling in gluten harvest of 5 + 10 wheats as higher protein failed to deliver more gluten after some limit.

Reduction of phytic acid and enhancement of bioavailable micronutrients in food grains.

More than half of the world populations are affected by micronutrient malnutrition and one third of world's population suffers from anemia and zinc deficiency, particularly in developing countries. Iron and zinc deficiencies are the major health problems worldwide. Phytic acid is the major storage form of phosphorous in cereals, legumes, oil seeds and nuts. Phytic acid is known as a food inhibitor which chelates micronutrient and prevents it to be bioavailabe for monogastric animals, including humans, because they lack enzyme phytase in their digestive tract. Several methods have been developed to reduce the phytic acid content in food and improve the nutritional value of cereal which becomes poor due to such antinutrient. These include genetic improvement as well as several pre-treatment methods such as fermentation, soaking, germination and enzymatic treatment of grains with phytase enzyme. Biofortification of staple crops using modern biotechnological techniques can potentially help in alleviating malnutrition in developing countries.

Plasma membrane events associated with the meiotic divisions in the amphibian oocyte: insights into the evolution of insulin transduction systems and cell signaling.

BACKGROUND: Insulin and its plasma membrane receptor constitute an ancient response system critical to cell growth and differentiation. Studies using intact Rana pipiens oocytes have shown that insulin can act at receptors on the oocyte surface to initiate resumption of the first meiotic division. We have reexamined the insulin-induced cascade of electrical and ion transport-related plasma membrane events using both oocytes and intact plasma membranes in order to characterize the insulin receptor-steroid response system associated with the meiotic divisions. RESULTS: [(125)I]Insulin binding (K(d) = 54 ± 6 nM) at the oocyte plasma membrane activates membrane serine protease(s), followed by the loss of low affinity ouabain binding sites, with a concomitant 3-4 fold increase in high affinity ouabain binding sites. The changes in protease activity and ouabain binding are associated with increased Na(+)/Ca2(+) exchange, increased endocytosis, decreased Na(+) conductance resulting in membrane hyperpolarization, increased 2-deoxy-D-glucose uptake and a sustained elevation of intracellular pH (pHi). Hyperpolarization is largely due to Na(+)-channel inactivation and is the main driving force for glucose uptake by the oocyte via Na(+)/glucose cotransport. The Na(+) sym- and antiporter systems are driven by the Na(+) free energy gradient generated by Na(+)/K(+)-ATPase. Shifts in α and/or ß Na(+)-pump subunits to caveolar (lipid raft) membrane regions may activate Na/K-ATPase and contribute to the Na(+) free energy gradient and the increase in both Na(+)/glucose co-transport and pHi. CONCLUSIONS: Under physiological conditions, resumption of meiosis results from the concerted action of insulin and progesterone at the cell membrane. Insulin inactivates Na(+) channels and mobilizes fully functional Na(+)-pumps, generating a Na(+) free energy gradient which serves as the energy source for several membrane anti- and symporter systems.

Restoration of absolute diffraction efficiency and blaze angle of carbon contaminated gratings by ultraviolet cleaning.

An UV cleaning technique has been used for the removal of carbon contamination from grating surface, using oxygen free-radicals generated by the absorption of UV radiation (172 nm) in atmospheric oxygen. The extent of restoration of absolute diffraction efficiency (ADE) and grating blaze angle of a carbon-contaminated variable line-spaced concave grating (average line spacing of 1200 lines/mm, blaze angle 3.2 deg, and blaze wavelength 10 nm) has been studied over a 5-70 nm wavelength range. The contamination (due to prolonged use in extreme-ultraviolet spectrograph) resulted in a drastic reduction in the diffraction efficiency of grating, along with a change in the blaze angle. The UV cleaning led to the restoration of blaze angle as well as to an increase in the ADE by more than an order of magnitude for the first two diffraction orders (i.e., from ~0.2 to ~7.2%) for the first diffraction order and 0.1 to ~5% for the second diffraction order at the blaze wavelength. The study is useful for the restoration of carbon-contaminated costly optics.

Human Leukocyte Antigen-DQ Genotyping in Pediatric Celiac Disease.

Purpose: The purpose of this study was to determine the pattern of human leukocyte antigen (HLA)-DQ genotype in children diagnosed with celiac disease (CD) (biopsy proven), and to compare this with a control group; and secondarily, to correlate HLA genotypes with clinical profiles of CD. Methods: This cross-sectional comparative observational study included 26 controls and 52 patients diagnosed with CD who presented at Sir Padampat Mother and Child Health Institute, Jaipur, from May, 2017 to October, 2018. HLA DQ genotype was assessed for each patients and correlated with clinical profiles. Results: HLA DQ2/DQ8 genotypes were significantly more common in CD (present in 100.0% cases) than in controls (23.1%) in Northern India (Rajasthan). When HLA DQ2.5 and DQ8 were present together, individuals had significantly more atypical presentations and severe findings on duodenal biopsy. Similarly, patients with the HLA DQ 2.5 genotype were also predisposed to more severe endoscopic findings, while HLA DQ2.2 predisposed them to less severe biopsy findings. HLA DQ8 was significantly associated with later age at diagnosis (>5 years) and shorter stature. The highest HLA DQ relative risk (RR) for CD development was associated with HLA DQ2.5 and DQ2.2 in combination, followed by HLA DQ2.5 and DQ8 in combination, while HLA DQx.5 and HLA DQ2.2 together had the lowest risk. Conclusion: HLA DQ2/DQ8 genotypes are strongly associated with pediatric CD patients in northern India. These genotypes and their combinations may be associated with different clinical presentations of CD, and may help predict severity of CD.

Pancytopenia in celiac disease-A case series of 20 children.

Pancytopenia in children with celiac disease (CeD) is postulated to be due to nutritional deficiency such as vitamin B12, folate and copper or an autoimmune process resulting in aplastic anemia with hypoplastic marrow. In the present case series, we report the profile and explore the etiology of pancytopenia among children with CeD. There are only a few case reports of pancytopenia in children with CeD. We enrolled newly diagnosed cases of CeD and pancytopenia presenting in the celiac disease clinic over three years. Detailed evaluation was carried out for the cause of pancytopenia. We followed up on the cases for compliance and response to gluten-free diet at three months, six months and 12 months. Twenty patients were eligible for inclusion. They were divided into two groups: one with aplastic anemia with hypoplastic marrow labeled as Gp CeD-AA and the other with megaloblastic/nutritional anemia labeled as Gp CeD-MA. Patients in Gp CeD-MA presented with classical symptoms of CeD as recurrent diarrhea, abdomen distension, pallor and poor weight gain. They had none or just one transfusion requirement and had an early and complete recovery from pancytopenia. Patients in Gp CeD-AA presented with atypical symptoms such as epistaxis, short stature, fever, pallor and weakness. They had a multiple blood transfusion requirement and had delayed and partial recovery from pancytopenia. Pancytopenia is not a disease in itself but is the presentation of an underlying disease. It can occur due to various coexisting disorders in children with CeD, which can be as simple as nutritional deficiencies to as complex as an autoimmune process or malignancy. CeD should be included in the differential diagnosis of aplastic anemia as CeD and aplastic anemia both have a similar pathological process involving T cell destruction of tissues.

Mathematical model of mechanobiology of acute and repeated synaptic injury and systemic biomarker kinetics.

Background: Blast induced Traumatic Brain Injury (bTBI) has become a signature casualty of military operations. Recently, military medics observed neurocognitive deficits in servicemen exposed to repeated low level blast (LLB) waves during military heavy weapons training. In spite of significant clinical and preclinical TBI research, current understanding of injury mechanisms and short- and long-term outcomes is limited. Mathematical models of bTBI biomechanics and mechanobiology of sensitive neuro-structures such as synapses may help in better understanding of injury mechanisms and in the development of improved diagnostics and neuroprotective strategies. Methods and results: In this work, we formulated a model of a single synaptic structure integrating the dynamics of the synaptic cell adhesion molecules (CAMs) with the deformation mechanics of the synaptic cleft. The model can resolve time scales ranging from milliseconds during the hyperacute phase of mechanical loading to minutes-hours acute/chronic phase of injury progression/repair. The model was used to simulate the synaptic injury responses caused by repeated blast loads. Conclusion: Our simulations demonstrated the importance of the number of exposures compared to the duration of recovery period between repeated loads on the synaptic injury responses. The paper recognizes current limitations of the model and identifies potential improvements.