Pure, urea and thiourea doped hippuric acid (HA) single crystals have been grown in acetone using slow evaporation technique at a constant temperature, with the vision to improve the properties of ...the crystals. The crystal systems and the unit cell parameters of the grown crystals were identified from single crystal X-ray diffraction. The crystalline nature of the grown crystals was confirmed by powder X-ray diffraction and the diffraction peaks were indexed. The variations in composition due to the addition of dopants were identified by CHNS analysis. FT-IR studies reveal the presence of different vibrational bands. The optical characteristics were assessed by UV–vis analysis and it indicates the transmission in the visible region. TGA and DSC studies indicate the thermal behavior of pure and doped crystals. The Second Harmonic Generation (SHG) has been tested using Kurtz Powder Technique for the pure and doped crystals. It is found that the thiourea doped hippuric acid crystals have SHG efficiency of 2.08 times higher than that of potassium dihydrogen phosphate (KDP) single crystal. The dielectric studies were carried out, and the variations of dielectric constant and dielectric loss with temperature have been studied.
Variation of dielectric constant with temperature of pure hippuric acid crystals.
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► Pure, urea and thiourea doped hippuric acid crystals were grown by slow evaporation. ► Variations in composition due to the addition of dopants were identified by CHNS analysis. ► SHG efficiency of thiourea doped hippuric acid crystals is 2.08 times that of KDP crystal. ► Thermal and optical studies reveal the suitability of the crystals for device applications.
There is a paucity of literature on the histopathological aspects of congenital pouch colon (CPC) and immunohistochemical (IHC) assessment has not been reported. So we planned to study the ...histopathological and IHC findings within the spectrum of CPC and compare the findings with the normal colon.
This is a descriptive prospective study on CPC patients. There were 49 cases of CPC (42 males and 7 females) and 13 controls. Histological examination was done using hematoxylin and eosin and Masson trichrome stain. IHC analysis was done with actin, myosin, and desmin antibodies, and neuron-specific enolase and S100 markers for counting ganglionic cells.
Histologically, congestion, edema and hemorrhage were seen in mucosa, submucosa, and serosa. Muscle layers were disrupted and divided into bands. An additional muscle coat inside of the muscularis propria was seen in CPC types 1 and 2. Mature ganglionic cells were reduced and muscle layers showed reduced and patchy positivity for smooth muscle actin, myosin, and desmin compared to a normal colon.
Histopathological and IHC findings suggest that CPC has distinct defects in the neuromusculature.
Structural and motional features in the denatured state of a protein dictate the early folding events starting from that state and these features vary depending upon the nature of the denaturant ...used. Here, we have attempted to decipher the early events in the folding of Dynein Light Chain protein (DLC8), starting from DMSO-d6 denatured state. Multinuclear NMR experiments were used to obtain the full spectral assignment. The HSQC spectrum shows the presence of two sets of peaks for the residues Met 1, Ser 2, Arg 4, Ala 11, Met 17, Thr 26, Lys 44, Tyr 50, Asn 51, Trp 54, His 55, Val 58, Gly 59, Ser 64, Tyr 65, His 68, Phe 86, Lys 87 indicating the presence of slow conformational transition in the heterogeneous ensemble. Analysis of residual structural propensities with secondary 13C chemical shifts, 3J(HN−Hα) coupling constants and 1H-1H NOE revealed the presence of local preferences which encompass both native and non-native like structures. The spectral density calculations, as obtained from measured R1, R2 and 1H-15N steady state NOE values provide insights into the backbone dynamics on the milli to picosecond timescale. The segment Ser 14 – His 55 exhibits slow motions on the milli- to microsecond timescale arising from conformational exchange. The presence of native like structural preference, as well as conformational exchange classifies the above segment as the nucleation site of folding. Based on the observations, we propose here, the probable hierarchy of folding of DLC8 on dilution of denaturant: the two helices are formed first followed by the formation of β2 and β5.
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► Residue level characterization of the DMSO-d6 denatured ensemble of DLC8 with NMR. ► Presence of slow conformational exchange in the denatured ensemble. ► Native helical propensities in the segment Ser 14- His 55. ► High conformational exchange in the segments corresponding to native helices. ► Two helices are supposedly formed first during folding followed by β2 and β5.
Photograph of as grown crystal of LHB.
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•Quality crystals of amino acid nonlinear optical crystal, l-Histidine Bromide were grown by using slow evaporation technique.•The etching ...studies shows that the deformation of the crystal is more comparatively with water as etchant,when compared with ethanol and methanol.•The refractive index of the l-Histidine Bromide crystal was found by Brewster’s angle method as 1.516.•The l-Histidine Bromide crystals have a relative NLO efficiency nearly 0.97 times of KDP.•The laser damage threshold value is determined as 1.323 GW/cm2 thus making the crystals suitable for applications.
Nonlinear optical (NLO) materials find broad applications in optical data storage, lasers, optical signal processing, second harmonic generation, etc. Though a large number of nonlinear optical materials are available, their applications are limited due to physical and chemical properties.Since the nonlinear optical crystals of amino acids contain a proton donor carboxyl acid (COOH) group and the proton acceptor amino (NH2) group, they are considered as the apt materials for NLO applications. In the present work, good quality crystals of l-Histidine bromide were grown by using slow evaporation technique. The FTIR spectral analysis reveals the presence of different vibrational bands of l-Histidine Bromide.The optical characteristics were assessed by UV–vis analysis, which shows that the crystals have a transmission in the visible range.The etching studies were performed on the crystals, which shows that the crystal does not undergo considerable deformation under the action of solvents. The refractive index of the l-Histidine Bromide crystal was found by Brewster's angle method as 1.516. The Second harmonic generation studies and laser damage threshold studies reveal that crystals have comparable SHG conversion efficiency and high laser damage threshold value to that of the standard KDP crystal, thus making the crystals suitable for applications.
...a PubMed search using “COVID-19” done on March 28, 2020 revealed 1795 references. 5 Fighting the COVID-19 pandemic, in a way, is a step backward with respect to all the rigor that clinical trials ...require – adherence to timelines and schedules, compliance with guidelines and study protocol, detailed and complete follow-up evaluation, administration of study medication, reporting of symptoms and side effects, finding answers to questions about their conditions. The discussion needs to involve all concerned stakeholders, including Clinical Trial Investigators, trial staff, patients, Ethics Committee/Institutional Review Board (EC/IRB), sponsors, CROs, regulatory authorities, ancillary service providers. 3,5,10 For patients it is an important decision between following instructions from public health authorities to stay at home in self-isolation family bubbles versus going to the health-care facility for treatment and related clinical trial schedule of events.
Recently, nanostructured tungsten oxide-based materials have received much attention in the field of the gas sensor due to their superior size-dependent gas adsorption and catalytic properties. ...Herewith, we have successfully prepared pure and Ag-doped WO3 nanostructures via a hydrothermal method. The effect of doping (Ag) in WO3 and their gas sensing properties was systematically studied. Interestingly, the Ag-2 sensor revealed the enhanced gas sensing response of 52404% @1000 ppb, which is 5-fold higher than that of the pure WO3 sample at 150 ℃. Moreover, Ag-2 sensor possessed an ultra-fast response and recovery time of 1 s and 3.5 s. Further, as-prepared sensors exhibit excellent selectivity, repeatability, and long-term stability. In addition, the DFT calculations were performed to evaluate the adsorption and charge transfer dynamics of NH3, H2S, and NO2 gas molecules on pure and Ag-doped WO3 surfaces. These results pave the new pathway to developing real-time metal oxide-based gas sensors at lower operating temperatures.
•The pure and Ag-WO3 samples were prepared by hydrothermal method.•The enhanced Sensing response of 52404% (1000 ppb) for 3% Ag-WO3 sample @ 150 ℃.•The 3% Ag sensor possessed an ultra-fast response and recovery time of 1 and 3.5 s.•Theoretically predicted results are well in agreement with experimental findings.
To understand the rules governing the protein folding process it is essential to study the stability and unfolding of small monomeric proteins. Here, I present the pH dependent thermal unfolding ...energetics and conformational stability analysis of monomeric Dynein light chain protein (DLC8) in the pH range 3.5–2.0. DLC8 is the smallest and the most conserved light chain among the light chains of the dynein motor assembly. Thermal unfolding of DLC8 monomer is much complex with the presence of transient intermediates, which is in contrast to the notion that small proteins unfold via simple two-state process. The unfolding seems to be more cooperative at lower pH and the temperature of highest conformational stability (
T
s) is found to be maximum (295.7
K) at pH 2.76. Stability curves have been simulated to understand the thermodynamic parameters that govern the shapes of the experimentally obtained curves. Further, an effort has been made to correlate the observed differences in the denaturation energetics with the protein sequence in order to throw light on the structure-folding paradigm of the DLC8 monomer.
The technique of facile co-precipitation was employed to prepare the pure ZnO and Gd doped ZnO photocatalysts. The physio-chemical properties of the prepared samples were analysed through various ...analytical techniques. The X-ray diffraction analysis clearly shows that higher amount of Gd dopant creates the secondary phase in addition to normal peaks of ZnO crystals. The visible light absorption increases with increasing the Gd amount in ZnO which is evident from UV–Vis DRS analysis. The as synthesized 3% Gd doped ZnO exhibits the highest photocatalytic activity on Methylene blue dye degradation under visible light irradiation compared to other photocatalysts. The enhanced degradation activity of the photocatalyst demonstrates the improved visible light absorption of the materials due to the incorporation of Gd ions into the ZnO lattice. The possible reaction mechanism and degradation pathway of the photocatalyst has been discussed in detail and the stability of the catalyst have been confirmed by recycle process.
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•Facile co-precipitation method was used to prepare the pure and Gd doped ZnO photocatalyst.•The visible light absorption increases with increasing the percentage of Gd.•The Methylene blue dye degradation efficiency reaches 93% under visible light irradiation over 3% Gd doped ZnO.
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