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Two new complexes, [Mn(ppt)2(o-phen)] (1) and [Mn(aptt)(Cl)(o-phen)2]·2Haptt·H2O (2) with 4-phenyl (phenyl-acetyl)-3-thiosemicarbazide (Hppt) and 4-amino-5-phenyl-1,2,4-triazole-3-thiolate (Haptt) have been synthesized containing o-phenanthroline (o-phen) as a coligand. These complexes have been characterized by elemental analyses, IR and UV–Vis spectroscopic techniques, thermogravimetric analysis (TGA), magnetic susceptibility and single crystal X-ray diffraction data. The complexes are paramagnetic and have a distorted octahedral geometry. In complex 2, two molecules of Haptt and one water molecule are cocrystalized outside the coordination sphere. Complexes 1 and 2 are fluorescent and upon their excitation at 38 167 cm−1, exhibit emissions at 27 173 and 32 894 cm−1, respectively. TGA of complexes 1 and 2 indicate that the metal is converted into metal oxide at very high temperature. In the solid state, the crystal structure of both complexes are stabilized by various inter and intramolecular interactions. To explore the possible electrochemical applications of the complexes 1 and 2, they are immobilized on glassy carbon electrode using Nafion®. Cyclic voltammetry technique is used to characterize the metal complex immobilized electrodes in basic medium. Both complexes demonstrate excellent electrocatalytic activity towards electrochemical oxygen reduction. Since the electrocatalytic materials for oxygen reduction can dramatically increase the efficiency of the fuel cells and metal-air batteries, these metal complexes can be used as cathodic catalyst material in fuel cells and in metal-air batteries.

Background: Hypovitaminosis D is a very common prevalence in India as well as Middle East. Studies indicate the frequency to be anywhere between 44-96% among adults in Middle east, while in India it is estimated to range in between 50 – 94%. Our report is an attempt to study vitamin D status from two tropical countries; India and Bahrain and present status of vitamin D deficiency as well as insufficiency in a comparison summary.Methods: This retrospective study in our reference lab included data from a total of 2591 samples from Bahrain and 2596 samples from India. Serum vitamin D estimation was done by chemiluminescence immunoassay or CLIA and reported as per the classification given by the US Endocrine Society. Our reference laboratory provides diagnostic services to Bahrain and thus data from both the countries were available for analysis.Results: Our analysis detected vitamin D deficiency to be 66.2% among samples from India in comparison to 41.4% from Bahrain, and this difference was statistically significant at p

New compounds 5-benzyl-N-phenyl-1,3,4-thiadiazol-2-amine (Bptha, 1), 2-(5-phenyl-1,3,4-thiadiazol-2-yl) pyridine (Pthp, 2) and 2-(5-methyl-1,3,4-thiadiazole-2-ylthio)-5-methyl-1,3,4-thiadiazole (Mtmth, 3) have been synthesized and characterized with the aid of elemental analyses, IR, NMR and single crystal X-ray data. The structure of compounds 1, 2 and 3 are stabilized via intramolecular as well as intermolecular hydrogen bonding and crystallize in monoclinic system with space group P 1, P21/n and P 1, respectively. During the course of reaction, the substituted thiosemicarbazide/thiohydrazide get cyclized into the corresponding thiadiazole in the presence of manganese(II) nitrate via loss of H2O to yield compounds 1 and 2. However condensation occurred in the case of 5-methyl-1,3,4-thiadiazole-2-thiol which yielded 2-(5-methyl-1,3,4-thiadiazole-2-ylthio)-5-methyl-1,3,4-thiadiazole (3) by loss of one mole of H2S from two moles of 5-methyl-1,3,4-thiadiazole-2-thiol in the presence of manganese(II) acetate. The geometry optimization has been performed using DFT method and geometrical parameters thus obtained for the compounds have been compared with their single crystal X-ray data. The negative values of HOMO and LUMO energies for the molecules indicate that they are stable. The electronic transition from the ground state to the excited state due to a transfer of electrons from the HOMO to LUMO levels is mainly associated with the π⋯π transition.

The in situ generated new ligand (Z)-N′(1,3,4-thiadiazol-2-yl) acetimidate (tha) formed complexes [Ni(tha)2] (1), [Cu(tha)2] (2) and [Zn(tha)2] (3) in one pot condensation reactions between metal(II) acetate and 2-amino-1,3,4-thiadiazole. The complexes have been characterized with the aid of elemental analyses, IR, Raman, magnetic susceptibility and single crystal X-ray data. The metal complexes 1, 2 and 3 crystallize in monoclinic system with space group P21/c. In the complexes, the newly generated ligand is bonded through thiadiazole ring nitrogen and oxygen of acitimidate group, thus acting as N, O bidentate ligand producing a six membered chelate ring. Ni(II), Cu(II) and Zn(II) complexes of the type [ML2] contain extended hydrogen bonding providing supramolecular architecture. Various types of π–π interactions are responsible for the semiconducting behavior of the complexes and also stabilize their crystal structures. The geometry optimization has been performed using DFT method and geometrical parameters thus obtained for the complexes have been compared with their single crystal XRD structures. The molecular electrostatic potential (MEP) and contour maps of the ligand and the complexes are also calculated by DFT method.

Objective In vitro antidiabetic efficacy of Cucurbita maxima seed extract (CMSE) has already been studied in our previous findings. Thus, in order to validate these findings in biological system, in vivo antidiabetic activity of aqueous extract was investigated in normal as well as diabetic experimental models. Methods Variable doses of extract were administered orally to normal and STZ induced mild diabetic rats during fasting blood glucose (FBG) and glucose tolerance test (GTT) studies. In order to determine the extract's antidiabetic potential long-term FBG and post prandial glucose (PPG) studies were also carried out. Results Most effective dose of 200 mg kg−1 of CMSE decreases the blood glucose level (BGL) in normal rats by 29.02% at 6 h during FBG studies and 23.23% at 3 h during GTT. However, the maximum reduction observed in BGL of mild diabetic rats during GTT the same interval of time was 26.15%. Moreover, in case of severely diabetic rats a significant reduction of 39.33% was observed in FBG levels whereas, in case of positive control, rats treated with 2.5 mg kg−1 of glipizide, a fall of 42.9% in FBG levels was observed after 28 days. Results of PPG level also showed a fall of 33.20% in severely diabetic rats as compared to the positive control showing a fall of 44.2% at the end of the 28 days. Conclusion Thus, the present study validate the hypoglycemic and antidiabetic effect of CMSE and hence this extract could be explored further for developing as a novel antidiabetic agent., Graphical abstract

Temporal evolution of electronic and nuclear wave packets created in strong-field excitation of the carbon dioxide molecule is studied employing momentum-resolved ion spectroscopy and channel-selective Fourier analysis. Combining the data obtained with two different pump-probe set-ups, we observed signatures of vibrational dynamics in both, ionic and neutral states of the molecule. We consider far-off-resonance two-photon Raman scattering to be the most likely mechanism of vibrational excitation in the electronic ground state of the neutral CO2. Using the measured phase relation between the time-dependent yields of different fragmentation channels, which is consistent with the proposed mechanism, we suggest an intuitive picture of the underlying vibrational dynamics. For ionic states, we found signatures of both, electronic and vibrational excitations, which involve the ground and the first excited electronic states, depending on the particular final state of the fragmentation. While our results for ionic states are consistent with the recent observations by Erattupuzha et al. [J. Chem. Phys.144, 024306 (2016)], the neutral state contribution was not observed there, which we attribute to a larger bandwidth of the 8 fs pulses we used for this experiment. In a complementary measurement employing longer, 35 fs pulses in a 30 ps delay range, we study the influence of rotational excitation on our observables, and demonstrate how the coherent electronic wave packet created in the ground electronic state of the ion completely decays within 10 ps due to the coupling to rotational motion.

We have measured resonant-Auger decay following Cl 1s(-1) excitations in HCl and CH3Cl molecules, and extracted the pseudo-cross sections of different Cl 2p(-2) final states. These cross sections show clear evidence of shake processes as well as contributions of electronic state-lifetime interference (ELI). To describe the spectra we developed a fit approach that takes into account ELI contributions and ultrafast nuclear dynamics in dissociative core-excited states. Using this approach we utilized the ELI contributions to obtain the intensity ratios of the overlapping states Cl 1s(-1)4pπ/1s(-1)4pσ in HCl and Cl 1s(-1)4pe/1s(-1)4pa1 in CH3Cl. The experimental value for HCl is compared with theoretical results showing satisfactory agreement.

Shake processes of different origin are identified in the $\mathit{KLL}$ Auger spectrum of ${\mathrm{H}}_{2}\mathrm{S}$ with unprecedented detail. The $\mathit{KLL}$ Auger spectrum is presented together with the S $1{s}^{\ensuremath{-}1}$ photoelectron spectrum including the S $1{s}^{\ensuremath{-}1}{V}^{\ensuremath{-}1}n\ensuremath{\lambda}$ and S $1{s}^{\ensuremath{-}1}2{p}^{\ensuremath{-}1}n\ensuremath{\lambda}$ shake-up satellites with ${V}^{\ensuremath{-}1}$ and $n\ensuremath{\lambda}$ indicating a hole in the valence shell and an unoccupied molecular orbital, respectively. By using different photon energies between 2476 and 4150 eV to record the $\mathit{KLL}$ Auger spectra two different shake-up processes responsible for the satellite lines are identified. The first process is a shake-up during the Auger decay of the S $1{s}^{\ensuremath{-}1}$ core hole and can be described by S $1{s}^{\ensuremath{-}1}\ensuremath{\rightarrow}2{p}^{\ensuremath{-}2}{V}^{\ensuremath{-}1}n\ensuremath{\lambda}$. The second process is the Auger decay of the shake-up satellite in the ionization process leading to S $1{s}^{\ensuremath{-}1}{V}^{\ensuremath{-}1}n\ensuremath{\lambda}\ensuremath{\rightarrow}2{p}^{\ensuremath{-}2}{V}^{\ensuremath{-}1}n\ensuremath{\lambda}$ transitions. By combining the results of photoelectron and Auger spectra the involved ${V}^{\ensuremath{-}1}n\ensuremath{\lambda}$ levels are assigned.

Our prior studies demonstrated that cellular response of T helper 1 (Th1) type was generated by a soluble antigenic fraction (ranging from 89.9 to 97.1 kDa) of Leishmania donovani promastigote, in treated Leishmania patients as well as hamsters and showed significant prophylactic potential against experimental visceral leishmaniasis (VL). Eighteen Th1 stimulatory proteins were identified through proteomic analysis of this subfraction, out of which 15 were developed as recombinant proteins. In the present work, we have evaluated these 15 recombinant proteins simultaneously for their comparative cellular responses in treated Leishmania patients and hamsters. Six proteins viz. elongation factor-2, enolase, aldolase, triose phosphate isomerase, protein disulfide isomerase, and p45 emerged as most immunogenic as they produced a significant lymphoproliferative response, nitric oxide generation and Th1 cytokine response in PBMCs and lymphocytes of treated Leishmania patients and hamsters respectively. The results suggested that these proteins may be exploited for developing a successful poly-protein and/or poly-epitope vaccine against VL.

This paper proposes a modified positive feedback adiabatic logic (MPFAL) for ultra-low power circuits. MPFAL is based on positive DC voltage range 0.1 to 0.3 V. Half-adder and 1-bit full-adder incorporating this technique also been considered in this work. Comparison shows that average power is reduced in case of modified technique compared to positive feedback adiabatic logic (PFAL) for frequency range 10 MHz to 300 MHz and simulations are carried out by considering load capacitance from 30fF to 110fF. All the simulations have been done in Cadence Virtuoso Tool using UMC 180 nm CMOS technology. This technique can be used in ultra-low power digital circuits operated at higher frequencies.

Shake processes of different origin are identified in the KLL Auger spectrum of H2S with unprecedented detail. The KLL Auger spectrum is presented together with the S 1s−1 photoelectron spectrum including the S 1s−1V−1nλ and S 1s−12p−1nλ shake-up satellites with V−1 and nλ indicating a hole in the valence shell and an unoccupied molecular orbital, respectively. By using different photon energies between 2476 and 4150 eV to record the KLL Auger spectra two different shake-up processes responsible for the satellite lines are identified. The first process is a shake-up during the Auger decay of the S 1s−1 core hole and can be described by S 1s−1→2p−2V−1nλ. The second process is the Auger decay of the shake-up satellite in the ionization process leading to S 1s−1V−1nλ→2p−2V−1nλ transitions. By combining the results of photoelectron and Auger spectra the involved V−1nλ levels are assigned.

Ternary logic has been evolved from binary logic due to its many advantages as it is energy efficient, less complex and faster speed for serial transfer. Due to these technological advancements ternary circuits have attracted many researchers to implement ternary circuits. In digital system, NOT, NOR and NAND are of importance as they are the main building blocks of many complex arithmetic and logic circuits. In this paper, we discuss the basic ternary gates and some circuits implemented by using FinFET. An extensive simulation is performed for all the gates and circuits using Tspice Simulator. FinFET is being adapted instead of traditional MOSFET because of its captivity over the drawbacks occurred during narrowing to nanometer scale. Results obtained have expected functionality of each gate and circuits, additionally there is enhancement in performance parameters.

Two new mixed ligand complexes, [Cu(en)2](4-hpythol)2·2H2O (4-hpythol = 5-(4-hydroxy-phenyl)-1,3,4-thiadiazole-2-thiol) (2) and [Cu(en)2(5-thot)2] (5-thot = 5-thiophen-2-yl-3H-1,3,4-oxadiazole-2-thione (3), have been prepared, containing en as the co-ligand. The starting ligands, potassium salts of thiohydrazide carbodithioate (RCSNHNHCSSK)/hydrazine carbodithioate (RCONHNHCSSK), underwent cyclization during the crystallization or complexation in the presence of ethylenediamine (en) and converted to 5-(4-hydroxy-phenyl)-1,3,4-thiadiazole-2-thiol and 5-thiophen-2-yl-3H-1,3,4-oxadiazole-2-thione, respectively. The metal complexes have been characterized with the aid of elemental analyses, IR, magnetic susceptibility and single crystal X-ray studies. The ligand 4-hpythol and complexes 2 and 3 crystallize in the triclinic and monoclinic systems, space group P 21/n, P 1 ¯ and P 21/c, respectively. The ligand is present in the deprotonated thiol form in [Cu(en)2](4-hpythol)2·2H2O (2), where it is ionically bonded through the thiol sulfur atom, while potassium N′-(thiophene-2-carbonyl) hydrazinecarbodithioate after cyclization is present as the thione form in [Cu(en)2(5-thot)2] (3) and is covalently bonded through the N atom of the resulting oxadiazole-2-thione. The most noteworthy feature of 4-hpythol (1) is its existence in the thiol form in the solid state. Complex 3 show irreversible redox behavior, assignable to a M2+/M3+ one electron transfer. ESR signals were registered for complexes 2 and 3. Both complexes contain extended hydrogen bonding, providing supramolecular frameworks.

In visceral leishmaniasis, Th1 types of immune responses correlate with recovery from and resistance to disease, and resolution of infection results in lifelong immunity against the disease. Leishmanial Ags that elicit proliferative and cytokine responses in PBMCs from cured/exposed/Leishmania patients have been characterized through proteomic approaches, and elongation factor-2 is identified as one of the potent immunostimulatory proteins. In this study, we report the cloning and expression of Leishmania donovani elongation factor-2 protein (LelF-2) and its immunogenicity in PBMCs of cured/exposed Leishmania-infected patients and hamsters (Mesocricetus auratus). Leishmania-infected cured/exposed patients and hamsters exhibited significantly higher proliferative responses to recombinant Lelf-2 (rLelF-2) than those with L. donovani-infected hosts. The soluble L. donovani Ag stimulated PBMCs of cured/exposed and Leishmania patients to produce a mixed Thl/Th2-type cytokine profile, whereas rLelF-2 stimulated the production of IFN-γ, IL-12, and TNF-α but not IL-4 or IL-10. Further, rLelF-2 downregulated LPS-induced IL-10 as well as soluble L. donovani Ag-induced IL-4 production by Leishmania patient PBMCs. The immunogenicity of rLelF-2 was also checked in hamsters in which rLelF-2 generates strong IL-12– and IFN-γ–mediated Th1 immune response. This was further supported by a remarkable increase in IgG2 Ab level. We further demonstrated that rLelF-2 was able to provide considerable protection (∼65%) to hamsters against L. donovani challenge. The efficacy was supported by the increased inducible NO synthase mRNA transcript and Th1-type cytokines IFN-γ, IL-12, and TNF-α and downregulation of IL-4, IL-10, and TGF-β. Hence, it is inferred that rLelF-2 elicits a Th1 type of immune response exclusively and confers considerable protection against experimental visceral leishmaniasis.

Objectives Miltefosine, an orally effective antileishmanial drug, works directly on the parasite by impairing membrane synthesis and subsequent apoptosis of the parasite and has also been reported to have macrophage-activating functions that aid parasite killing. We investigated the type of immunological responses generated in miltefosine-treated Leishmania donovani-infected hamsters, which simulate the clinical situation of human kala-azar. Methods Twenty-five-day-old infected hamsters, treated with miltefosine at 40 mg/kg for 5 consecutive days, were euthanized on days 30 and 45 post treatment (p.t.) and checked for parasite clearance and for real-time analysis of mRNAs of the Th1/Th2 cytokines interferon-γ (IFN-γ), interleukin-12 (IL-12), tumour necrosis factor-α (TNF-α), inducible nitric oxide synthase (iNOS), IL-4, IL-10 and transforming growth factor-β (TGF-β), nitric oxide (NO) production, the lymphocyte transformation test (LTT) and antibody responses. Responses were compared with the normal and Leishmania-infected groups at the same time points. Results By day 45 p.t. there was a significant increase in the mRNA expression of iNOS, IFN-γ, IL-12 and TNF-α, whereas there were significant decreases in IL-4, IL-10 and TGF-β in cured hamsters as compared with their infected counterparts. In vitro stimulation of lymphocytes with concanavalin A and soluble Leishmania donovani antigen showed a maximum LTT response and there was a gradual increase in the NO level (∼7-fold compared with infected counterparts). Anti-Leishmania IgG and IgG1 levels, found to be elevated in the infected group, decreased significantly after treatment but there was a significant increase in IgG2 isotype. Conclusions Treatment of Leishmania-infected hamsters with miltefosine reverses the Th2-type response into a strong Th1-type immune response.

We have performed a study of the formation of H+2 and H + 3 ions during dissociative ionization of various organic molecules under single collision conditions. The reactions are brought about by electron impact and are observed by multiparticle coincidence momentum imaging. We investigate how the presence of certain functional groups in the molecule is reflected in the kinematics of associative reactions.

Reaction of N′-(2-methyl-benzoyl)-hydrazinecarbodithioic acid methyl ester (H2mbhe) with HgCl2 and Mn(OAc)2·4H2O yielded the polymeric [Hg3(tot)2(μ-SCH3)4]n (1) and dimeric [Mn2(Hmbhe)2(μ-mbmst)2]CHCl3 (2), respectively. These complexes have been synthesized and their structures investigated by elemental analyses, NMR, IR, UV–Vis and single crystal X-ray data. In one unit of the polymeric structure of complex 1, two Hg(II) are similar bonded to an exocyclic sulfur of oxadiazole and three sulfur of SCH3 whereas one Hg(II) is two coordinate linked to two SCH3 fragments. Thus, complex 1 shows the presence of tetrahedral as well as linear Hg(II) in the same molecule. The dimeric octahedral complex 2 contains thiadiazolyl hydrazide moiety (mbmst) formed from H2mbhe under thermal condition which is bonded in a tetradentate manner by two nitrogens and one bidentate bridged oxygen between two Mn(II) centers. In the solid state both complexes are stabilized by intermolecular hydrogen bonding and form supramolecular architecture.

The reaction of Mn(OAc) 2 ·4H 2 O with bis (5-phenyl-2H-1,2,4-triazole)-3-yl-disulfane (H 2 ptds·2H 2 O) ( 1 ) yielded new complex [Mn(ptds)( o -phen) 2 ] ( 2 ). It is observed that under similar conditions the reaction of Co(OAc) 2 with H 2 ptds·2H 2 O ( 1 ) leads to thermolysis of the S–S bond of the disulfane to yield [Co(pts)( o -phen) 2 ]·H 2 O·0.5C 2 H 5 OH, with the newly generated organic ligand 5-phenyl-2H-1,2,4-triazole-3-sulfinate, (pts) 2− . The ligand H 2 ptds·2H 2 O ( 1 ), [Mn(ptds)( o -phen) 2 ] ( 2 ) and [Co(pts)( o -phen) 2 ]·H 2 O·0.5C 2 H 5 OH ( 3 ) crystallized into monoclinic, trigonal and triclinic crystal systems, respectively. The triazole ring nitrogen of the bidentate ligand chelates the Mn(II) center forming a seven membered chelate ring, while N, O donor sites of the resulting triazole sulfinate bond Co(II) to form a five membered chelate. The resulting complexes are paramagnetic and have a distorted octahedral geometry.

Two mononuclear mixed-ligand complexes [Ni(en)2(ppdtt)2]·2H2O (1) and [Cu(en)2(ppdtt)2]·2H2O (2) have been synthesized with Hppdtt = 4-phenyl-5-pyridin-4-yl-2,4-dihydro-1,2,4-triazole-3-thione and ethylenediamine (en). The compounds have been characterized by elemental analyses, IR, UV–Vis, ESR, magnetic susceptibility, cyclic voltammetry and single crystal X-ray studies. The geometry of complexes 1 and 2 are distorted octahedral. The complexes 1 and 2 crystallized in the orthorhombic and monoclinic systems with space groups P b c a and P 21/n, respectively. Both complexes 1 and 2 show quasi-reversible redox behaviour assignable to M2+/M3+ one electron transfer. An ESR signal was registered for complex 2. Hydrogen bonds together with π–π and C–H⋯π interactions play an important role in the formation of the final supramolecular framework.

Two novel monometallic complexes [Co(ppt)(SO4)(H2O)4)]·H2O (1) and [Zn(ppt)2(CH3COO)2(H2O)2]·(2) of ppt = phenyl-(5-pyridin-4-yl[1,3,4]thiadiazol-2-yl)-amine have been synthesized and their structures investigated by elemental analyses, IR, UV–Vis., magnetic susceptibility and single crystal X-ray. The geometry of both complexes are distorted octahedral. The π–π and C H⋯π interactions play important role along with hydrogen bonding to form host–guest cavity. The hydrogen-bonding interactions between adjacent layers extend these structures to overall 3D supramolecular architectures.

Composition of multielement samples is estimated by using a synthetic generated spectrum utilizing a nonlinear fitting routine. By fitting simultaneously a large number of emission lines, the error in the estimation is minimized. The procedure for synthetic spectrum generation includes self-absorption of emission lines by taking into account the number density of different species in the plasma. The Stark width of different emission lines is iteratively calculated based on the observed width and the degree of self-absorption in the individual lines. This procedure is found to be successful for achieving convergence of the retrieval algorithm even for dense spectra as well as for resolving merged lines with accuracy. This scheme was applied on a stainless steel and brass sample, and the laser-induced breakdown spectroscopy results match well with the reference value obtained from the electron probe microanalyzer measurement.

A bulk size (∼60 mm length and 20 mm diameter) single crystal of L-cysteine hydrochloride monohydrate has been successfully grown for the first time by the unidirectional Sankaranarayanan–Ramasamy method and found to be a nonlinear optical material by observing the second harmonic generation (SHG). The crystal structure has been confirmed by single-crystal as well as powder X-ray diffraction analysis. The Fourier transform–Raman technique was used to study the vibrational modes and functional groups. The grown crystal was found to be highly transparent. The crystalline perfection has been evaluated by high-resolution X-ray diffractometry and the grown crystal was found to be free from macroscopic defects such as structural grain boundaries. The relative SHG efficiency and laser damage threshold values were found to be 1.2 and 5.5 times that of a potassium dihydrogen phosphate crystal, respectively. The dielectric constant, dielectric loss and alternating current conductivity were measured by an impedance analyser over a wide range of frequency between 100 Hz and 5 MHz. The dielectric constant was found to be stable for the entire range of frequency with very small dielectric loss, making this material suitable for device applications. The present investigation reveals that the title compound, since it can be grown with desirable size along a predetermined direction and it is a good nonlinear optical material with the prerequisite optical and dielectric properties, is a good candidate for photonic or opto-electronic applications.

The new complexes [Mn(Hpchce) 2 ( o -phen)], {2[Mn(pchcm)( o -phen) 2 ]}·7H 2 O and [Ni(Hpchcm)( o -phen) 2 ]Cl·CH 3 OH with [N′-(pyridine-4-carbonyl)-hydrazine]-carbodithioic acid ethyl ester (H 2 pchce) and [N′-(pyridine-4-carbonyl)-hydrazine]-carbodithioic acid methyl ester (H 2 pchcm) have been synthesized, containing o -phenanthroline ( o -phen) as a coligand. These ligands and their complexes have been characterized by elemental analyses, IR, magnetic susceptibility and single crystal X-ray data. H 2 pchce ( 2 ), [Mn(Hpchce) 2 ( o -phen)] ( 3 ) {2[Mn(pchcm)( o -phen) 2 ]}·7H 2 O ( 4 ) and [Ni(Hpchcm)( o -phen) 2 ]Cl·CH 3 OH ( 5 ) crystallized in the monoclinic system, space group Pc , C 2/ c , P 21/ n and P 21/ n , respectively. The (N, O) donor sites of the bidentate ligands chelate the Mn(II) and Ni(II) centers forming a five-membered CN 2 OM ring. The resulting complexes are paramagnetic and have a distorted octahedral geometry.

Single crystals of the relatively new nonlinear optical material L-asparagine monohydrate have been successfully grown by the slow evaporation solution growth technique at room temperature in aqueous solution. The crystal system of the title material has been confirmed by powder X-ray diffraction. The crystalline perfection of the as-grown and annealed crystals has been evaluated by high-resolution X-ray diffraction. The as-grown single crystals (particularly when their size is large) were found to contain internal structural grain boundaries, and the crystalline perfection of these crystals was found to be improved substantially by annealing at low temperatures. The crystalline perfection and the measured physical properties were found to be correlated such that the second harmonic generation efficiency, optical transparency, fluorescence and dielectric properties are enhanced as the crystal quality improves.

Three new mixed ligand complexes [Mn(4-pytone)2(bipy)2]bipy (1), [Mn(pot)2(en)2] (2) and [Mn(4-mot)2(en)2] (3) (4-pytone = 5-(4-pyridyl)-1,3,4-oxadiazole-2-thione, pot = 5-phenyl-1,3,4-oxadiazole-2-thione, 4-mot = 5-(4-methoxy-phenyl)-1,3,4-oxadiazole-2-thione) have been prepared containing bipy/en as coligands. The starting material potassium N-(aryl-carbonyl)-hydrazinecarbodithioates (RCONHNHCSSK) underwent cyclization during complexation in the presence of bipy or en to give the corresponding 5-aryl-1,3,4-oxadiazole-2-thiones. The complexes have been characterized by physicochemical techniques and single crystal X-ray structure determination. In all cases, the manganese has a six coordinate octahedral arrangement coordinated by 4N atoms of two bipy/en and two covalently bonded N atoms of the oxadiazole-2-thione anions.

The products obtained by the reactions of Ni(OAc)2·4H2O with Hpot (Hpot = 5-phenyl-1,3,4-oxadiazole-2-thione) and [K(H2fchc)] (potassium N′-(furan-2-carbonyl) hydrazine carbodithioate), on treatment with excess of ethylenediamine (en), gave mixed ligand complexes [Ni(pot)2(en)2] (1) and [Ni(fot)2(en)2] (2) (fot = 5-furan-(1,3,4)-oxadiazole-2-thione). These complexes have been characterized with the aid of elemental analyses, IR, magnetic susceptibility and single crystal X-ray studies. In both complexes, the heterocyclic ligand coordinates through oxadiazole nitrogen, and the ligand exists as the thione form. The complexes 1 and 2 have distorted octahedral geometries around the centrosymmetric Ni(II) center with trans oxadiazole ligands. Both complexes show extended hydrogen bonding to give a supramolecular framework.

Two new mixed ligand complexes [Ni(en) 2 (mot) 2 ] ( 1 ) and [Cu(en) 2 (mot) 2 ] ( 2 ) derived from potassium N ′-(4-methoxy-benzoyl) dithiocarbazate [K + (H 2 L) − ] containing en as the coligand have been synthesized. [K + (H 2 L) − ] undergoes cyclization in the presence of ethylenediamine and is converted to 5-(4-methoxy-phenyl [1,3,4]-oxadiazole-2-thione (mot) − . [Ni(en) 2 (mot) 2 ] and [Cu(en) 2 (mot) 2 ] have been characterized by various physicochemical techniques and single crystal X-ray. In [Ni(en) 2 (mot) 2 ] and [Cu(en) 2 (mot) 2 ] the metal ion has MN 6 core with six coordinate octahedral arrangement from four N atoms of two en and two N atoms from two mot anions.

Leishmania produce several types of mucin-like glycoproteins called proteophosphoglycans (PPGs) which exist as secretory as well as surface-bound forms in both promastigotes and amastigotes. The structure and function of PPGs have been reported to be species and stage specific as in the case of Leishmania major and Leishmania mexicana; there has been no such information available for Leishmania donovani. We have recently demonstrated that PPG is differentially expressed in sodium stibogluconate-sensitive and -resistant clinical isolates of L. donovani. To further elucidate the structure and function of the ppg gene of L. donovani, a partial sequence of its N-terminal domain of 1.6 kb containing the majority of antigenic determinants, was successfully cloned and expressed in prokaryotic as well as mammalian cells. We further evaluated the DNA-encoding N-terminal domain of the ppg gene as a vaccine in golden hamsters (Mesocricetus auratus) against the L. donovani challenge. The prophylactic efficacy to the tune of ∼80% was observed in vaccinated hamsters and all of them could survive beyond 6 mo after challenge. The efficacy was supported by a surge in inducible NO synthase, IFN-γ, TNF-α, and IL-12 mRNA levels along with extreme down-regulation of TGF-β, IL-4, and IL-10. A rise in the level of Leishmania-specific IgG2 was also observed which was indicative of enhanced cellular immune response. The results suggest the N-terminal domain of L. donovani ppg as a potential DNA vaccine against visceral leishmaniasis.

Objectives: The aim of this study was to resolve the putative pathway responsible for death induced by peganine hydrochloride dihydrate isolated from Peganum harmala seeds at cellular, structural and molecular level in Leishmania donovani, a causative agent of fatal visceral leishmaniasis. Methods: The mode of action was assessed using various biochemical approaches including phosphatidylserine exposure, estimation of mitochondrial transmembrane potential and in situ dUTP nick end labelling staining of nicked DNA in the parasite. Molecular modelling and molecular dynamics studies were conducted with DNA topoisomerase I to identify the target of peganine hydrochloride dihydrate mediating apoptosis. Further, DNA topoisomerase I inhibition by peganine hydrochloride dihydrate was also assessed using an L. donovani topoisomerase I relaxation assay. Results: Peganine hydrochloride dihydrate, besides being safe, was found to induce apoptosis in both the stages of L. donovani via loss of mitochondrial transmembrane potential. Molecular docking studies suggest that a binding interaction with DNA topoisomerase I of L. donovani (binding energy of 279 kcal/mol) forms a stable complex, indicating a possible role in apoptosis. The compound also inhibits L. donovani topoisomerase I. Conclusions: The compound induces apoptosis in L. donovani and inhibits DNA topoisomerase I.