l-myo-Inositol-1-Phosphate Synthase Expressed in Developing Organ: Isolation and Characterisation of the Enzyme from Human Fetal Liver

l-myo-inositol-1-phosphate synthase (MIPS; EC: 5.5.1.4) activity has been detected and partially purified for the first time from human fetal liver. Crude homogenate from the fetal liver was subjected to streptomycin sulphate precipitation and 0?C60?% ammonium sulphate fractionation followed by successive chromatography through DEAE cellulose and BioGel A 0.5-m columns. After the final chromatography, the enzyme was purified 51-fold and 3.46?% of MIPS could be recovered. The human fetal liver MIPS specifically utilised d-glucose-6-phosphte and NAD⁺ as its substrate and coenzyme, respectively. It shows pH optima between 7.0 and 7.5 while the temperature maximum was at 40?°C. The enzyme activity was remarkably stimulated by NH ₄ ⁺ , slightly stimulated by K⁺ and Ca²⁺ and highly inhibited by Zn²⁺, Cu²⁺ and Hg²⁺. The K _m values of MIPS for d-glucose-6-phosphate and NAD⁺ were found to be as 1.15 and 0.12?mM respectively while the V _max values were 280?nM and 252?nM for d-glucose-6-phosphate and NAD⁺ correspondingly. The apparent molecular weight of the native enzyme was determined to be 170?kDa.     

Some results on series and parallel systems of randomized components

We study the system (series/parallel) where the components are randomly chosen from two different batches. We assume that one batch is more reliable than the other in some stochastic sense. In the case of series systems we show that, under certain conditions, lifetime of one system dominates that of the other in different stochastic orders viz. hazard rate, down shifted hazard rate and likelihood ratio orders. Further, we show that the same principle holds for the reversed hazard rate and the likelihood ratio orders in the case of parallel systems.     

Study of quenching of anthracene fluorescence by [60]fullerene

[60]Fullerene has been shown to have a very high quenching effect on the fluorescence of anthracene at room temperature in n-hexane, n-heptane and carbontetrachloride medium. The possibility that the quenching is due to ground state electron donor-acceptor (EDA) complex formation between [60]fullerene and anthracene has been shown to be untanable in the concentration range used ( approximately 10(-5)moldm(-3) in both anthracene and C(60)). No exciplex formation under the present experimental conditions has been observed. In the non-quenching solvents n-hexane and n-heptane the Stern-Volmer constant follows the right trend with respect to change in solvent viscosity but in case of the quenching solvent CCl(4), the trend is opposite.     

Enhanced ferromagnetism in nano-sized Zn0.95Mn0.05O grains

The present work reports ferromagnetism by doping magnetic Mn atoms in the diamagnetic ZnO matrix and the ferromagnetism has been extended up to 640 K in nano-grained Zn_0.95Mn_0.05O samples. The bulk and nano-grained samples were stabilized in hexagonal crystal structure with space group p63mc. The grain size and lattice strain of the samples were estimated from room temperature XRD spectrum. Surface morphology of the samples was examined at room temperature using SEM picture and EDX spectrum. The ferromagnetism of the bulk material shows enhancement in nano-grained samples, which was mainly due to the solution of Mn atoms into the lattice sites of ZnO by mechanical milling. The enhancement of magnetic moment and ferromagnetic ordering temperature with reduction in grain size has been understood in terms of the core-shell structure and existing theoretical models. The present work also demonstrated the role of surface spin disorder on the enhancement of ferromagnetism in Zn_0.95Mn_0.05O nanograins.     

Monomer and Radiation-Mediated Sago Starch Blend Film: Mechanical and Thermal Property Optimization

Bio-blend films were prepared with sago starch and N-vinyl-2-pyrrolidone (NVP) by the casting method, varying the concentrations of sago starch (100 to 93%) and NVP (0 to 7%). The formulations were designated as F1 (starch 100%), F2 (starch 97%), F3 (starch 95%), and F4 (starch 97%). The highest tensile strength (TS), tensile modulus (TM), and elongation at break (Eb%) were found correspondingly to be 30.47 MPa, 407.74 MPa, and 8.25% for the F3 formulation. Gamma radiation was applied to films to modify their performance through grafting and cross-linking. The highest TS, TM, and Eb% were found at 500 krad dose and they were 38.12 MPa, 481.00 MPa, and 9.78%, respectively for F3 formulation. The water uptake nature and thermal properties of the treated and untreated films were also investigated.     

Design and in situ synthesis of a Cu-based porous framework featuring isolated double chain magnetic character

A Cu-based double chain MOF was synthesized in hydrothermal conditions using an in situ ligand formation method. This double chain MOF shows temperature dependent ferromagnetic (long range ordering) and antiferromagnetic (intra double chain) coupling. The magnetic behaviour originating from the individual double chain remains almost same even after structural collapse due to the removal of guest water molecules.     

A naphthalene-based Al3+ selective fluorescent sensor for living cell imaging

An efficient fluorescent Al(3+) receptor, N-(2-hydroxy-1-naphthalene)-N'-(2-(2-hydroxy-1-naphthalene)amino-ethyl)-ethane-1,2-diamine (L) has been synthesized by the condensation reaction between 2-hydroxy naphthaldehyde and diethylenetriamine. High selectivity and affinity of L towards Al(3+) in ethanol (EtOH) as well as in HEPES buffer at pH 7.4, makes it suitable to detect intracellular Al(3+) with fluorescence microscopy. Metal ions, viz. Li(+), Na(+), K(+), Mg(2+), Ca(2+), Mn(2+), Co(2+), Ni(2+), Cu(2+), Zn(2+), Ag(+), Cd(2+), Hg(2+) and Pb(2+) do not interfere. The lowest detection limit for Al(3+) is 3.0 × 10(-7) M and 1.0 × 10(-7) M in EtOH and HEPES buffer respectively.     

Synthesis and thermoluminescence characteristics of γ-irradiated K3Ca2(SO4)3F:Eu or Ce fluoride

New halophosphor K₃Ca₂(SO₄)₃F activated by Eu and Ce has been synthesized by a co-precipitation method and characterized according to its thermoluminescence. The formation of traps in rare earth doped K₃Ca₂(SO₄)₃F and the effects of γ-radiation dose on the glow curve are discussed. The glow curve of K₃Ca₂(SO₄)₃F:Ce shows a prominent single peak at 150°C, whereas K₃Ca₂(SO₄)₃F:Eu and K₃Ca₂(SO₄)₃F:Ce,Eu at 142°C and 192°C, respectively. A single glow peak indicates that there is only one set of trap being activated within the particular temperature range. The presented phosphors are also studied because of its fading, reusability and trapping parameters. There was just 2% fading during a period of 10 days, indicating no serious fading problem. Trapping parameters such as order of kinetics (b), activation energy (E) and frequency factor (S) were calculated by using Chen's half-width method. The observations presented in this paper are good for lamp phosphors as well as solid-state dosimeter.     

Design of a Hybrid Fiber-Optic Network Using 3-D Optical Code Sequences

We present the design of a 3-dimensional (3-D) noncoherent optical hybrid network. We also report the design of a new family of 3-D codes for fiber optic hybrid networks. We show that the hybrid network allows for shorter bit times and a higher number of users, given a set chip rate, compared to previously conceived networks. These newly designed hybrid single-pulse-per-row (HSPR) codes have very low autocorrelation side-lobes and very small cross-correlation peaks. We compare the performance of our hybrid model using our codes with the Optical Orthogonal Codes (OOCs) and Temporal/Spatial (T/S) codes and show that the new network can support a greater number of users and higher data rates than those using OOCs and T/S codes.     

Excited-State Electron Transfer in 1,1,4,4-Tetracyanobuta-1,3-diene (TCBD)- and Cyclohexa-2,5-diene-1,4-diylidene-Expanded TCBD-Substituted BODIPY-Phenothiazine Donor–Acceptor Conjugates

A new set of donor–acceptor (D–A) conjugates capable of undergoing ultrafast electron transfer were synthesized using 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY)-substituted phenothiazine, SM1–SM3 , by a Pd-catalyzed Sonogashira cross-coupling reaction and a [2+2] cycloaddition–electrocyclic ring-opening reaction. The incorporation of 1,1,4,4-tetracyanobuta-1,3-diene (TCBD) and cyclohexa-2,5-diene-1,4-diylidene-expanded TCBD (abbreviated as DCNQ=dicyanodiquinodimethane) in BODIPY-substituted phenothiazine resulted in significant perturbation of the optical and electronic properties. The absorption spectrum of both SM2 and SM3 showed red shifted absorption as compared to SM1 . Additionally, both SM2 and SM3 exhibited a distinct intramolecular charge-transfer (ICT) transition in the near-IR region more so for SM3 . The electrochemical study revealed multi-redox processes due to the presence of redox-active phenothiazine, BODIPY, TCBD or DCNQ entities. Using data from spectral, electrochemical and computational studies, an energy-level diagram was established to witness excited-state electron-transfer events. Finally, evidence of electron transfer and their kinetic information was secured from studies involving a femtosecond transient absorption technique. The time constants for excited-state electron-transfer events in the case of SM2 and SM3 were less than 5 ps revealing ultrafast processes.