Interpenetrated Lattices of Quaternary Chalcogenides Displaying Magnetic Frustration, High Na-Ion Conductivity, and Cation Redox in Na-Ion Batteries.

A series of quaternary selenides, NaxMGaSe4 (M = Mn, Fe, and mixed Zn/Fe), have been synthesized for the first time employing a high-temperature solid-state synthesis route through stochiometric or polychalcogenide flux reactions. Along with the selenides, a previously reported sulfide analogue, NaxFeGaS4, is also revisited with new findings. These compounds form an interpenetrated structure made up of a supertetrahedral unit. The electrochemical evaluations exhibit a reversible (de)intercalation of ∼0.6 and ∼0.45 Na-ions, respectively, from Na2.87FeGaS4 (1a) and Na2.5FeGaSe4 (2) involving Fe2+/Fe3+ redox when cycled between 1.5 and 2.5 V. Mössbauer spectroscopy of 1a shows the existence of a mixed oxidation state of Fe2+/3+ in the pristine compound and reversible oxidation of Fe2+ to Fe3+ during the electrochemical cycles. Na2.79Zn0.6Fe0.4GaSe4 possesses a reasonably high room temperature ionic conductivity of 0.077 ms/cm with an activation energy of 0.30 eV. The preliminary magnetic measurements show a bifurcation of FC-ZFC at 4.5 and 2.5 K, respectively, for 1a and Na3MnGaSe4 (4) arising most likely from a spin-glass like transition. The high negative values of the Weiss constants -368.15 and -308.43 K for 1a and 4, respectively, indicate strong antiferromagnetic interactions between the magnetic ions and also emphasize the presence of a high degree of magnetic frustration in these compounds.

Primary angiitis of central nervous system - A challenging diagnosis.

Primary angiitis of the central nervous system is a rare disease characterized by vasculitis of the central nervous system without any systemic involvement. This review aims to provide an insight into the existing stagnancies in the diagnostic approach and management of this disease. The clinical presentation is typically nonspecific, ranging from headaches, altered sensorium, and seizures to recurrent ischemic strokes. The definitive diagnosis can only be ascertained by histopathological studies of tissue obtained from a brain biopsy. While angiography can provide clues to diagnosis, it has often been normal, even in biopsy-proven cases. Primary angiitis of the central nervous system continues to be a diagnostic challenge as little progress has been made over the years in the diagnosis and management strategies. Considering the vast list of mimickers of primary angiitis of the central nervous system and the existence of a significant proportion of imaging-negative and biopsy-negative cases, it becomes imperative to devise universally accepted diagnostic criteria for this disease. Steroids in combination with cyclophosphamide are the agents used to achieve remission. Rituximab can be an alternative. The treatment-related toxicity of cyclophosphamide warrants larger trials for alternative drugs to be studied.

Discovery of an olivine-type lithium manganese thiophosphate, LiMnPS4, via a building block approach.

An olivine-type orthothiophospate LiMnPS4 has been synthesized for the first time through a building block approach by reacting preformed ternary lithium thiophospate with MnCl2. Diffuse reflectance measurements show an optical band gap of 2.36 eV, which is further confirmed by DFT calculations. Irreversible weak ferromagnetic ordering and metamagnetism are verified through preliminary magnetic measurements.

Zn-based physiometacomposite nanoparticles: distribution, tolerance, imaging, and antiviral and anticancer activity.

The aim of this study was to investigate the distribution, tolerance, and anticancer and antiviral activity of Zn-based physiometacomposites (PMCs). Manganese, iron, nickel and cobalt-doped ZnO, ZnS or ZnSe were synthesized. Cell uptake, distribution into 3D culture and mice, and biochemical and chemotherapeutic activity were studied by fluorescence/bioluminescence, confocal microscopy, flow cytometry, viability, antitumor and virus titer assays. Luminescence and inductively coupled plasma mass spectrometry analysis showed that nanoparticle distribution was liver >spleen >kidney >lung >brain, without tissue or blood pathology. Photophysical characterization as ex vivo tissue probes and LL37 peptide, antisense oligomer or aptamer delivery targeting RAS/Ras binding domain (RBD) was investigated. Treatment at 25 µg/ml for 48 h showed ≥98-99% cell viability, 3D organoid uptake, 3-log inhibition of ß-Galactosidase and porcine reproductive respiratory virus infection. Data support the preclinical development of PMCs for imaging and delivery targeting cancer and infectious disease.

Clinical Spectrum of Movement Disorders in Neurology Inpatients in a Tertiary Care Centre.

Background Little data are available on the spectrum of movement disorders in inpatients, particularly those admitted in neurology specialty. This may be related to the fact that patients presenting with movement disorders are usually evaluated from outpatient clinics. Objective The aim of this study is to provide data on the pattern of movement disorders in neurology inpatients. Materials and Methods Patients admitted through emergency department or neurology clinic with complaints of movement abnormalities were recruited in this study from October 2019 to September 2020. Cases were subjected to proforma-based detailed history, examination, and appropriate investigations. Statistical Analysis Descriptive statistics using SPSS 20. Results and Conclusion Bradykinesia with or without tremor was the most common movement disorder (28.3%), followed by ataxia and dystonia (24.5% each) and hemifacial spasm and myoclonus (7.5% each). Chorea, tic disorder, and hemiballismus were also reported. Etiologies included Parkinson disease, Wilson's disease, subacute sclerosing panencephalitis (SSPE), drugs, stroke, spinocerebellar ataxia, Huntington's disease, neuroacanthocytosis, and others. Dystonia represented the most common disorder in the younger age group (44.4%), whereas bradykinesia and/or tremor represented the most common movement disorder in the older age group (46.4%). This study demonstrates the characteristic distribution of movement disorders in neurology inpatients.

Interplay between Oxo and Fluoro in Vanadium Oxyfluorides for Centrosymmetric and Non-Centrosymmetric Structure Formation.

Herein, we report the syntheses of two lithium-vanadium oxide-fluoride compounds crystallized from the same reaction mixture through a time variation experiment. A low temperature hydrothermal route employing a viscous paste of V2O5, oxalic acid, LiF, and HF allowed the crystallization of one metastable phase initially, Li2VO0.55(H2O)0.45F5⋅2H2O (I), which on prolonged heating transforms to a chemically similar yet structurally different phase, Li3VOF5 (II). Compound I crystallizes in centrosymmetric space group, I2/a with a = 6.052(3), b = 7.928(4), c = 12.461(6) Å, and ß = 103.99(2)°, while compound II crystallizes in a non-centrosymmetric (NCS) space group, Pna21 with a = 5.1173(2), b = 8.612(3), c = 9.346(3) Å. Synthesis of NCS crystals are highly sought after in solid-state chemistry for their second-harmonic-generation (SHG) response and compound II exhibits SHG activity albeit non-phase-matchable. In this article, we also describe their magnetic properties which helped in unambiguous assignment of mixed valency of V (+4/+5) for Li2VO0.55(H2O)0.45F5⋅2H2O (I) and +4 valency of V for Li3VOF5 (II).

Neuromyelitis optica spectrum disorders.

The disease concept of Neuromyelitis Optica Spectrum Disorders(NMOSD) has undergone a significant change over the last two decades including the detection of Myelin Oligodendrocyte Glycoprotein(MOG) antibody in patients who are seronegative for aquaporin-4 antibody. Aquaporin-4 antibody positive NMOSD is now regarded as an immune astrocytopathy. Conversely, MOG antibody associated disease is known to target myelin rather than astrocytes, leading to an NMOSD syndrome with distinct clinical and radiological features. Incorporation of clinical features like area postrema syndrome, brainstem syndrome, diencephalic syndrome and cortical manifestations as core clinical characteristics into the revised diagnostic criteria has widened the clinical spectrum of NMOSD. With the development of these criteria, it is possible to make the diagnosis at an earlier stage so that effective immunosuppression can be instituted promptly for a better long-term prognosis. Newer therapeutic agents have been introduced for aquaporin-4 seropositive NMOSD disease; however, challenges remain in treating seronegative disease because of limited treatment options.

Eco-Friendly Synthesis, Crystal Chemistry, and Magnetic Properties of Manganese-Substituted CoFe2O4 Nanoparticles.

The authors report on the effect of manganese (Mn) substitution on the crystal chemistry, morphology, particle size distribution characteristics, chemical bonding, structure, and magnetic properties of cobalt ferrite (CoFe2O4) nanoparticles (NPs) synthesized by a simple, cost-effective, and eco-friendly one-pot aqueous hydrothermal method. Crystal structure analyses indicate that the Mn(II)-substituted cobalt ferrites, Co1-x Mn x Fe2O4 (CMFO, x = 0.0-0.5), were crystalline with a cubic inverse spinel structure (space group Fd 3 m ). The average crystallite size increases from 8 to 14 nm with increasing Mn(II) content; the crystal growth follows an exponential growth function while the lattice parameters follow Vegard's law. Chemical bonding analyses made using Raman spectroscopic studies further confirm the cubic inverse spinel phase. The relative changes in specific vibrational modes related to octahedral sites as a function of Mn content suggest a gradual change of measure of inversion of the ferrite lattice at nanoscale dimensions. Small-angle X-ray scattering and electron microscopy revealed a narrow particle size distribution with the spherical shape morphology of the CMFO NPs. The zero-field-cooled and field-cooled magnetic measurements revealed the superparamagnetic behavior of CMFO NPs at room temperature. The sample with x = 0.3 indicates a lower value of blocking temperature (9.16 K) with the improved (maximum) value of saturation magnetization. The results and the structure-composition-property correlation suggest that the economic, eco-friendly hydrothermal approach can be adopted to process superparamagnetic nanostructured magnetic materials at a relatively lower temperature for practical electronic and electromagnetic device applications.

Synthesis, Characterization, and Optimization of Magnetoelectric BaTiO3-Iron Oxide Core-Shell Nanoparticles.

Improvement of magnetic, electronic, optical, and catalytic properties in cutting-edge technologies including drug delivery, energy storage, magnetic transistor, and spintronics requires novel nanomaterials. This article discusses the unique, clean, and homogeneous physiochemical synthesis of BaTiO3/iron oxide core-shell nanoparticles with interfaces between ferroelectric and ferromagnetic materials. High-resolution transmission electron microscopy displayed the distinguished disparity between the core and shell of the synthesized nanoparticles. Elemental mapping and line scan confirmed the formation of the core-shell structure. Energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy detected the surface iron oxide phase as maghemite. Rietveld analysis of the X-ray diffraction data labeled the crystallinity and phase purity. This study provides a promising platform for the desirable property development of the futuristic multifunctional nanodevices.

Amino/Amido Conjugates Form to Nanoscale Cobalt Physiometacomposite (PMC) Materials Functionally Delivering Nucleic Acid Therapeutic to Nucleus Enhancing Anticancer Activity via Ras-Targeted Protein Interference.

Aberrant splicing and protein interaction of Ras binding domain (RBD) are associated with melanoma drug resistance. Here, cobalt or nickel doped zinc oxide (ZnO) physiometacomposite (PMC) materials bind to RNA and peptide shown by Ninhydrin staining, UV-vis, Fourier transform infrared, and circular dichroism spectroscopy. PMCs deliver splice switching oligomer (SSO) into melanoma cells or 3-D tumor spheroids shown by flow cytometry, fluorescence microscopy, and bioluminescence. Stability in serum, liver, or tumor homogenate up to 48 h and B16F10 melanoma inhibition ≥98-99% is shown. These data suggest preclinical potential of PMC for delivery of SSO, RBD, or other nucleic acid therapeutic and anticancer peptides.

Significant Reduction of Defect States and Surface Tailoring in ZnO Nanoparticles via Nano-Bio Interaction With Glucose for Bio-Applications.

In this study, we have investigated the structural and optical properties of nanoconjugates (NJs) consisting of phase pure zinc oxide (ZnO) nanoparticles (NPs) with glucose biomolecules. All NJs were fabricated using a standard biochemical synthesis process. Structural, optical, vibrational, and biochemical interface properties of nano-bio composites are probed by different complementary characterization techniques. The XRD patterns of the NPs and NJs illustrate a highly phase pure ZnO structure. A visible green emission in the photoluminescence spectrum, mainly associated with the oxygen vacancies on the surface of ZnO nanostructure, is significantly reduced by the incorporation of glucose biomolecules. The strong binding interaction of glucose biomolecule on the surface of ZnO NPs results in the reduction in green-yellow-orange emission intensities. The interaction of glucose molecules modifies oxygen vacancies by capturing free electrons from the ZnO surface region. Significant changes in the peak intensity and relative peak position of some of the glucose and ZnO NPs in Raman spectra refer to the direct binding between these two nano- and bio-components. In the X-ray photoelectron spectroscopy, the binding energy of O 1s core level in NJs increases from 531 eV (O 1s core level position for ZnO) and the increment is more with higher initial glucose concentration in the solution during synthesis. This study serves as a promising platform for the development of new kinds of NJs and investigation of their interfacial properties which can take the frontier forward for integration and multifunctionality.

Soft chemical routes to electrochemically active iron phosphates.

New iron phosphates with related structures have been synthesized using hydrothermal and ion-exchange routes, and their electrochemical properties were investigated. First, NaFe(HPO4)2 was synthesized employing a hydrothermal route and its structure was determined from single-crystal X-ray diffraction data. Subsequent Na+ and partial proton ion exchange with Li+ ion produced a known phase, Li2Fe(H0.5PO4)2, and complete deprotonation of Li2Fe(H0.5PO4)2 with Li+ by employing a solid-state ion-exchange route produced the new phase Li3Fe(PO4)2. The structure of the latter was solved from synchrotron powder X-ray data by employing ab initio methods. All of these phases are highly crystalline, built up of similar connectivities between FeO6 octahedra and PO4 tetrahedral units. Magnetic susceptibility measurements and room-temperature 57Fe Mössbauer spectroscopic studies confirm the 3+ oxidation state of the compounds and their antiferromagnetic ordering with Li2Fe(H0.5PO4)2 showing some interesting metamagnetic behavior. The compounds are stable up to 400 °C and undergo facile electrochemical lithium/sodium insertion through the reduction of Fe3+ to Fe2+. Galvanostatic charge-discharge studies indicate that up to 0.6 lithium ion and 0.5 sodium ion per formula unit can be inserted at average voltages of 3.0 and 2.75 V for lithium and sodium ion batteries, respectively, for NaFe(HPO4)2. The partially Li ion exchanged compound Li2Fe(H0.5PO4)2 showed better cycle life and experimentally achievable capacities up to 0.9 Li insertion with strong dependence on particle size. The electrochemical Li insertion in Li3Fe(PO4)2 was also investigated. The electrochemistry of these three related phases were compared with each other, and their mechanism of Li insertion was investigated by ex situ PXRD.

A Systematic Study on the Structural and Optical Properties of Vertically Aligned Zinc Oxide Nanorods Grown by High Pressure Assisted Pulsed Laser Deposition Technique.

In this study, we synthesize high quality vertically aligned ZnO (VAZO) nanorods on silicon, sapphire, and indium tin oxide (ITO) substrates by using pulsed laser deposition (PLD) technique at high growth pressure (0.3 Torr). Systematic changes in structural and optical properties of VAZO nanorods are studied by varying the substrate temperature (500-600 °C) and number of pulsed laser shots during the deposition. ZnO nanoparticles deposited at high pressure act as nucleation sites, eliminating requirement of catalyst to fabricate VAZO nanorods. Two sharp ZnO peaks with high intensity correspond to the (0002) and (0004) planes in X-ray diffraction pattern confirm the growth of ZnO nanorods, oriented along the c-axis. Scanning Electron Microscopy (SEM) images indicate a regular arrangement of vertically aligned hexagonal closed pack nano-structures of ZnO. The vertical alignment of ZnO nanorods is also supported by the presence of E2 (high) and A1 (LO) modes in Raman spectra. We can tune the diameter of VAZO nanorods by changing growth temperature and annealing environments. Photoluminescence spectroscopy illustrates reduction in defect level peak intensities with increase in diameter of VAZO nanorods. This study signifies that high pressure PLD technique can be used more efficiently for controlled and efficient growth of VAZO nanorods on different substrates.

A highly fluorinated lithium iron phosphate with interpenetrating lattices: electrochemistry and ionic conductivity.

Li5Fe2PO4F8, a new member of the family of alkali transition metal fluorophosphates, has been synthesized and characterized using single-crystal X-ray diffraction, 57Fe Mössbauer spectroscopy and magnetic susceptibility measurements. The existence of an infinite {-[PO4(FeF4)2]-}∞ tetrahedral network in an inter-penetrated diamond lattice, along with the presence of seven unique Li sites, presents interesting structural features of this structure-type for energy storage applications. The initial results of (de)lithiation reveal that a relatively low fraction of theoretical capacity may be utilized reversibly (0.2 Li+ ion per formula unit), possibly due to the lack of available free volume for Li+ insertion. The high Li content and the existence of large channels in all 3-dimensions of space also offer opportunities to study this material as a candidate for solid-state electrolytes. The results from electro-impedance measurements reveal the reasonable activation energy of Li diffusion (0.70 eV), which is also supported by theoretical calculations.

Magnetically Frustrated Quaternary Chalcogenides with Interpenetrating Diamond Lattices.

A series of quaternary sulfides of the composition Na3MGaS4 (M = Mn (1), Fe (2), and Co (3)) have been synthesized in sealed quartz ampules. In these compounds, divalent transition metal and Ga occupy the same crystallographic site in the Ga-S network, forming a supertetrahedral, T2 (adamantane) unit, through the corner-sharing of four M/GaS4 tetrahedra. The corner sulfur atoms of the T2 clusters are further connected to similar T2 units to form an open continuous three-dimensional (3D) anionic framework of composition {[Ga2M2S8]n}6-. The framework resembles a zinc blende structure type if each T2 cluster is considered as a single tetrahedron and two such frameworks are intertwined to generate channels wherein reside the extra-framework Na+ ions. Placement of transition metals (Mn or Fe or Co) in the corner of a perfect supertetrahedron, adamantane building unit, generates an ideal lattice for geometrical magnetic frustration, which, on dilution with nonmagnetic metal (Ga), creates an ideal case for random frustration. Preliminary magnetic measurements indicate high negative values of the Weiss constant (-200 to -400 K) and the absence of any magnetic ordering, reinforcing the presence of magnetic frustration in all of these compounds.

Probing nonlinear optical coefficients in self-assembled peptide nanotubes.

Self-assembled l,l-diphenylalanine (FF) peptide micro/nanotubes represent a class of biomimetic materials with a non-centrosymmetric crystal structure and strong piezoelectricity. The peptide nanotubes synthesized by a liquid phase method yield tube lengths in the hundreds of micron range, inner diameters in the few hundred nanometer range, and outer diameters in the 5-15 µm range. Second harmonic generation (SHG) polarimetry from individual self-assembled FF nanotubes is used to obtain the nonlinear (NLO) optical coefficients as a function of the tube diameter and thermal treatment. The ratio of the shear to the longitudinal component (d15/d33) of the NLO coefficient increases with the diameter of the tubes. One of the transverse components of the nonlinear coefficient is found to be negative, and its magnitude with respect to the longitudinal component increases with the tube diameter. Thermal treatment of individual FF tubes has a similar effect upon increasing the diameter of the tubes in SHG polarimetry. Concurrent Raman scattering measurements from individual FF tubes show a distinct change in the low frequency (100 cm-1) region with the diameter of the tubes reflecting subtle effects of water.

Enzyme and Cancer Cell Selectivity of Nanoparticles: Inhibition of 3D Metastatic Phenotype and Experimental Melanoma by Zinc Oxide.

Biomedical applications for metal and metal oxide nanoparticles are rapidly increasing. Here their functional impact on two well-characterized model enzymes, Luciferase (Luc) or ß-galactosidase (ß-Gal) was quantitatively compared. Nickel oxide nanoparticle (NiO-NP) activated ß-Gal (>400% control) and boron carbide nanoparticle (B4C-NP) inhibited Luc(<10% control), whereas zinc oxide (ZnO-NP) and cobalt oxide (Co3O4-NP) activated ß-Gal to a lesser extent and magnesium oxide (MgO) moderately inhibited both enzymes. Melanoma specific killing was in the order; ZnO > B4C ≥ Cu > MgO > Co3O4 > Fe2O3 > NiO, ZnO-NP inhibiting B16F10 and A375 cells as well as ERK enzyme (>90%) and several other cancer-associated kinases (AKT, CREB, p70S6K). ZnO-NP or nanobelt (NB) serve as photoluminescence (PL) cell labels and inhibit 3-D multi-cellular tumor spheroid (MCTS) growth and were tested in a mouse melanoma model. These results demonstrate nanoparticle and enzyme specific biochemical activity and suggest their utility as new tools to explore the important model metastatic foci 3-D environment and their chemotherapeutic potential.

The effect of citicoline on stroke: A comparative study from the Eastern part of India.

BACKGROUND: Citicoline is a novel neuroprotective agent used in acute stroke with a significantly favorable outcome. MATERIALS AND METHODS: A hundred patients who suffered from either an ischemic and hemorrhagic stroke and who presented to the hospital within 48 h of stroke onset were enrolled for the study. Of these 100 patients (age- and sex-matched), 50 patients were treated with citicoline along with the standard stroke management and considered as 'cases'. The other 50 patients who were administered the standard stroke treatment were considered as 'controls.' The baseline parameters of the patients was assessed using the National Institute of Health Stroke Scale. The patients were reassessed at follow up at the end of the 1st and 3rd month of the commencement of the therapy and their outcome was evaluated by the Barthel Index score (BI). RESULTS: The mean BI scores of all categories at the 1st and 3rd month were significantly higher in the citicoline treatment group (P < 0.001 at the 1st month and P = 0.002 at the 3rd month). An analysis of the categorized BI score showed that there was a significant difference in the number of patients in the categorized BI score (85-100) (at the 1st month follow-up: 0% in control vs. 7% in case group [P < 0.05]; and, at the 3rd month follow-up: 10% in control vs. 36% in citicoline case group [P < 0.05]). In the subgroup analysis, both patients suffering from either ischemic and hemorrhagic stroke (including all categories of BI score) in the citicoline treatment group showed a significantly higher mean BI score at the 1st month (ischemic: P = 0.003, hemorrhagic: P =0.04) and also at the end of the 3rd month (ischemic: P = 0.03, hemorrhagic: P = 0.03). An analysis of the categorized BI score (85-100) at the end of the 3rd month in both the hemorrhagic as well as the ischemic subgroups showed a significant incidence of improvement in the citicoline group compared with the control group (hemorrhagic-- control: 6.66% vs. CASE: 31.81%, P < 0.05 and ischemic-- control: 11.41% vs. CASE: 35.71%, P < 0.05). CONCLUSION: In patients suffering from stroke and presenting within 48 h of onset, treatment with citicholine increases the probability of complete recovery and a favorable outcome at the 1st month and at the end of the 3rd month in all the stroke groups.

Significant enhancement of optical absorption through nano-structuring of copper based oxide semiconductors: possible future materials for solar energy applications.

The optical absorption coefficient is a crucial parameter in determining solar cell efficiency under operational conditions. It is well known that inorganic nanocrystals are a benchmark model for solar cell nanotechnology, given that the tunability of optical properties and stabilization of specific phases are uniquely possible at the nanoscale. A hydrothermal method was employed to fabricate nanostructured copper oxides where the shape, size and phase were tailored by altering the growth parameters, namely the base media used, the reaction temperature, and the reaction time. The nano crystalline structures, phases, morphology, molecular vibrational modes, and optical properties were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, photoluminescence (PL), and UV-vis spectroscopy. A significantly large optical absorption coefficient, of the order of twice that of Si in the visible range, was observed in a particular phase mixture of nanostructured copper oxides. An optical absorption coefficient of 7.05 10(+5) cm(-1) at 525 nm was observed in a particular nanostructured phase mixture of copper oxides which is appreciably larger than commercially pure CuO (1.19 10(+5) cm(-1)) and Si (1.72 10(+5) cm(-1)). A possible mechanism of formation of phase mixtures and morphology of copper oxides has also been discussed, which opens up a roadmap in synthesis of similar morphology nanostructures for efficient solar cells.