Pharmaceutical grade sodium [99mTc] pertechnetate from low specific activity 99Mo using an automated 99Mo/99mTc-TCM-autosolex generator

Performance study of a computer controlled automated closed cyclic module for the separation and recovery of ^99mTc from low specific activity (n, γ) ⁹⁹Mo using methyl ethyl ketone (MEK) solvent extraction technique named ⁹⁹Mo/^99mTc-TCM-AUTOSOLEX (Technetium automated solvent extraction) Generator is described. The entire system is automated and controlled by a user-friendly PC based graphical user interface that actually supervises process via an embedded system based electronic controller. The average yield of separation of ^99mTc was above 85 % and ⁹⁹Mo breakthrough in ^99mTc pertechnetate was <0.002 %. The sodium pertechnetate obtained was a clear solution having pH 6–7, Radiochemical (RC). Purity >99 %, MEK content <0.1 % (v/v), Al and Mo content <10 µg/ml. R. C. Purity of ^99mTc-radiopharmaceuticals studied was not less than 96 %. Bio-Quality control studies confirm that sodium pertechnetate obtained was sterile and pyrogen free. Imaging studies in animals and humans with limited radiopharmaceuticals show that the quality of ^99mTc-pertechenate obtained in the present module was good enough to do clinical study.     

The fundamental properties of the direct injection method in the analysis of gaseous reduced sulfur by gas chromatography with a pulsed flame photometric detector

In this study, the fundamental aspects of gas chromatography with a pulsed flame photometric detector were investigated through the calibration of gaseous reduced sulfur compounds based on the direct injection method. Gaseous standards of five reduced sulfur compounds (hydrogen sulfide, methane thiol, dimethyl sulfide, carbon disulfide, and dimethyl disulfide) were calibrated as a function of injection volume and concentration level. The results were evaluated by means of two contrasting calibration approaches: fixed standard concentration method (variable volumetric injection of standard gases prepared at a given concentration) and fixed standard volume method (injection of multiple standards with varying concentrations at a given volume). The optimum detection limit values of reduced sulfur compounds, when estimated at 100 μL of injection volume, ranged from 2.37 pg (carbon disulfide) to 4.89 pg (dimethyl sulfide). Although these detection limit values improved gradually with decreasing injection volume, the minimum detectable concentration (e.g., in nmol mol⁻¹ scale) remained constant due to a balance by the sample volume reduction. The linearity property of pulsed flame photometric detector also appeared to vary dynamically with changes in its sensitivity. According to this study, the performance of pulsed flame photometric detector, when tested by direct injection method, is highly reliable to precisely describe the behavior of reduced sulfur compounds above ∼20 nmol mol⁻¹.     

Surface treatment of Basalt fiber for use in automotive composites

Balancing the performance, durability and safety requirements of automotive systems with the regulatory landscape in an environment of climate change has accelerated the search for sustainable fiber reinforced polymer composites for automobile structures. Glass fiber reinforced thermoplastic polymer composites (GFRP) are widely used in certain structures like front end modules and liftgate; However, they cannot be used in more demanding applications due to their low mechanical properties. Carbon fiber reinforced thermoplastic polymer composites (CFRP) are promising candidates for applications like bonnet, but their use is constrained by cost. Basalt fiber reinforced thermoplastic polymer composites (BFRP) are sustainable materials that can be positioned between GFRP and CFRP in terms of performance and cost-effectiveness. The mechanical performance of the BFRP depend on the quality of the fiber-matrix interface that aids in efficient load transfer from the matrix to the fiber. Typically, basalt fibers are inert in nature and need treatments to improve its adhesion to polymeric matrices. The major chemical treatments that are reviewed in this article include matrix functionalization, silane treatment, functionalized nanomaterial coating and plasma polymerization. The physical treatments reviewed include plasma treatment and milling. It is evident that chemically treating the basalt fiber with a functionalized nanomaterial yields BFRP with a good stiffness – toughness balance that can be used for challenging metal replacements as also in new emerging areas like sensing and 3D printing.     

Enhanced Production of High-Quality Biomass, δ-Aminolevulinic Acid,Bilipigments, and Antioxidant Capacity of a Food Alga <Emphasis Type="Italic">Nostochopsis lobatus</Emphasis>

The growing interest in natural food has raised the global demand for nutraceuticals. We studied enhanced production of biomass, delta-aminolevulinic acid (delta-ALA), bili pigments and antioxidant capacity of a food alga Nostochopsis lobatus in a full-factorial (three level) design with supplemental Zn, glutamine, and Zn + glutamine in batch culture. Production of biomass, pigments, and antioxidant capacity all were higher under immobilized cell cultures in comparison to free cell cultures. Maximum biomass (2,390 mg dry wt l(-1)), delta-ALA (2.715 microg mg(-1) dry wt h(-1)), phycocyanin (98.50 mg g(-1) dry wt), phycoerythrin (158.0 mg g(-1) dry wt), and antioxidant capacity (140.50 mumoles ascorbic acid equivalent capacity g(-1) fresh wt) were recorded when Zn and glutamine were supplemented together in the growth medium at pH 7.8. These effects were found to be significantly related to the activities of glutamine synthetase (GS(max): 490.2 nmoles mg protein(-1) min(-1)), glutamate synthase (GOGAT(max): 27.0 nmoles mg protein(-1) min(-1)), and glutamate dehydrogenase (GDH(max): 159.9 nmoles mg protein(-1) min(-1)). This study shows that N. lobatus could be a promising bioresource for the production of nutritionally rich biomass, delta-ALA, bili pigments, and antioxidants. Use of immobilized cells in batch culture supplemented with Zn and glutamine could be an effective approach for scaling up production for commercial use.     

Sol–gel polycondensation of tetraethoxysilane in ethanol in presence of vinyl modified guar gum: synthesis of novel nanocompositional adsorbent materials

Novel nanocomposite adsorbent materials were synthesized by condensation polymerization of TEOS in the presence of saponified guar-graft-poly(acrylonitrile) (SG) as template. The effect of changing the molecular size of SG on the final properties of the composite materials was investigated in this paper. The composites were thermally treated at temperatures ranging from 80 to 1100 °C, to obtain materials of different performance. The chemical, structural and textural characteristics of the composites were determined by FTIR, XRD, TGA-DSC and SEM studies. Their adsorption properties were monitored in terms of Zn (II) binding capacity which could be tailored by changing the template size and sintering temperature. The adsorption capacity of the composite at room temperature was enhanced five times when thermally treated at 900 °C with a maximum adsorption of 3.58 meq/g of the zinc (II). The adsorption could be further optimized to higher values and the materials could be successfully recycled for three consecutive cycles without any significant loss in the adsorption capacity.     

Enzyme Instructed Self‐assembly of Naphthalimide‐dipeptide: Spontaneous Transformation from Nanosphere to Nanotubular Structures that Induces Hydrogelation

Understanding the structure‐morphology relationships of self‐assembled nanostructures is crucial for developing materials with the desired chemical and biological functions. Here, phosphate‐based naphthalimide (NI) derivatives have been developed for the first time to study the enzyme‐instructed self‐assembly process. Self‐assembly of simple amino acid derivative NI‐Yp resulted in non‐specific amorphous aggregates in the presence of alkaline phosphatase enzyme. On the other hand, NI‐FYp dipeptide forms spherical nanoparticles under aqueous conditions which slowly transformed into partially unzipped nanotubular structures during the enzymatic catalytic process through multiple stages which subsequently resulted in hydrogelation. The self‐assembly is driven by the formation of β‐sheet type structures stabilized by offset aromatic stacking of NI core and hydrogen bonding interactions which is confirmed with PXRD, Congo‐red staining and molecular mechanical calculations. We propose a mechanism for the self‐assembly process based on TEM and spectroscopic data. The nanotubular structures of NI‐FYp precursor exhibited higher cytotoxicity to human breast cancer cells and human cervical cancer cells when compared to the nanofiber structures of the similar Fmoc‐derivative. Overall this study provides a new understanding of the supramolecular self‐assembly of small‐molecular‐weight hydrogelators.     

Oxidovanadium (IV) and iron (III) complexes with O2N2 donor linkage as plausible antidiabetic candidates: Synthesis,structural characterizations,glucose uptake and model biological media studies

With the upsurging cases of type II diabetic patients, the demand for safe and effective oral antidiabetic drugs is also increasing. Coordination complexes have proven their mettle as efficient oral drug candidates, which thereby motivated us in this work to design new transition metal complexes as plausible candidates for the treatment of diabetes. A reduced salen ligand, {H₂(hpdbal)₂-an} ( 1 ) derived vanadium (IV) and iron (III) complexes, namely, [V^IVO{(hpdbal)₂-an}] ( 2 ) and [{Fe^III (OH₂)((hpdbal)₂-an)}₂ μ₂-SO₄] ( 3 ) were synthesized in this study. The newly obtained ligand and complexes were characterized using usual analytical and spectroscopic techniques. The potential of these compounds in inducing increased glucose uptake by diabetic cells were studied by using insulin resistant HepG2 cells as model diabetic cells and 2-NBDG molecule as a D-glucose analogue and fluorescent tracker. The cells added with the vanadium (IV) complex 3 induced significant NBDG uptake of 95.4% which was higher than that induced by metformin, the standard antidiabetic drug. To elucidate the behavior of the complexes in biological media, model solution studies were conducted with a wide range of pH conditions and protein bovine serum albumin (BSA). The complexes demonstrated effective binding with BSA which was concluded through spectroscopic titration studies and were also found to be sufficiently stable over physiological pH conditions. The study can thus prove to be beneficial in the quest for new antidiabetic drugs.     

Pluronic F-127: An Efficient Delivery Vehicle for 3-(1'-hexyloxy)ethyl-3-devinylpyropheophorbide-a (HPPH or Photochlor)

To determine the impact of delivery vehicles in photosensitizing efficacy of HPPH, a hydrophobic photosensitizer was dissolved in various formulations: 1% Tween 80/5% dextrose, Pluronic P-123 and Pluronic F-127 in 0.5%, 1% and 2% phosphate buffer solutions (PBS). HPPH was also conjugated to Pluronic F-127, and the resulting conjugate (PL-20) was formulated in PBS. Among the different delivery vehicles, only Pluronic P-123 displayed significant vehicle cytotoxicity, whereas Pluronic F127 was nontoxic. Compared to PL-20, HPPH formulated in Tween80 and Pluronic F-127 showed higher cell-uptake, but lower long-term retention in Colon26 cell compared to PL-20. The higher retention of PL-20 was similarly observed during in vivo uptake with BALB/c mice baring Ct26 tumors. In contrast to the in vitro uptake experiments, PL-20 showed slightly higher uptake compared to HPPH formulated in Tween or Pluronic-F127. A significant difference in pharmacokinetic profile was also observed between the HPPH-Pluronic formulation and PL-20. Under similar in vivo treatment parameters (drug dose 0.47 µmol kg⁻¹, light dose: 135 J cm⁻² at 24 h post-injection of PS), HPPH formulated either in Tween or Pluronic F-127 formulation showed similar in vivo PDT efficacy (20–30% tumor cure on day 60), whereas PL-20 showed 40% tumor cure (day 60).     

Snthesis and x-ray structure of an isomeric cyclophosphazene complex containing antimony(III)

The monosilylated acyclic phosphazene ligand Me₃SiNP(NMe₂)₂NP(NMe₂)₂ NH₂ (3) has been synthesized and characterized. The reaction of 3 with antimony triacetate, Sb(OOCMe₃), in refluxing toluene forms a cyclic phosphazene derivative, [N{P(NMe₂)₂NH}₂Sb(OOCMe)₂ (4), which is characterized by elemental analyses, mass, IR and NMR spectroscopy and single-crystal X-ray structural analysis. Complex 4 crystallizes in the form of a cis and trans isomeric chain in the solid state.     

Proline-Specific Extracellular Aminopeptidase Purified from <Emphasis Type="Italic">Streptomyces lavendulae</Emphasis>

Aminopeptidases catalyze the cleavage of specific amino acids from the amino terminus of protein or peptide substrates. A proline-specific aminopeptidase was purified to homogeneity from the culture-free extract of Streptomyces lavendulae ATCC 14162 in sequential steps comprising ammonium sulfate precipitation, ultra-filtration, and column chromatography on Q-sepharose and Sephadex G-100. The purified protein showed approximately 60 kDa in SDS-PAGE and was optimally active at pH 6.5 and 40 °C. Kinetic studies showed a K _m and V _max of 0.23 mM and 0.087 μmol/min, respectively, using Pro-p-NA, the substrate with maximum specificity. Enzyme activity was inhibited by PMSF and ions like Zn²⁺, Co²⁺, and Ni²⁺. However, unlike other aminopeptidases, the activity was enhanced in the presence of DTT, 1,10-phenanthroline, EDTA, amastatin, and bestatin. Ions like Ca²⁺, Mg²⁺, and Mn²⁺ also enhanced the activity.