Determination of metformin hydrochloride in tablets by nuclear magnetic resonance spectrometry

The ¹H-n.m.r. signal of the drug (10–35 mg ml^?1) in deuterium oxide, with maleic acid as internal reference standard, is used. The integral of the peak at 3.06 ppm with respect to 3-trimethylsilylpropionic acid is compared with that at 6.3 ppm for the internal standard. The method is quantitative and free from interference by tablet excipients.     

Lateritic minerals for decontamination of radionuclides

Naturally available lateritic minerals (LM) have been used on laboratory scale for the removal of Ce, Gd and Lu radionuclides from nuclear industry and reactor effluents. The adsorption behavior using radiotracers is reported, describing factors such as the nature and strength of acids, particle size, temperature and equilibration time which influence the adsorption mechanism. The interference of various anions and organic complexing agents on sorption of these radiotracers has also been considered. The optimized physico-chemical conditions and high loading capacities suggest an, effective use of LM for the isolation of the radionuclides from industrial and reactor effluents. Leaching studies made on pelletized LM loaded with the radionuclides indicate their potential for disposal in reduced solid form for a longer period.     

Mössbauer study of elemental substitution in Nd18Fe76B6 alloy

Fe-rich Nd-Fe-B permanent magnetic materials are of great technological interest because of their superior magnetic properties such as coercivity and large energy products. These properties can be further enhanced by the substitution of Nd or Fe. We are presenting the results of atomic replacement of iron by Ga, Dy, Nb and Si, in the base material N₁₈Fe_{7 6}B₆, obtained by Mössbauer spectroscopy. It is observed that the net magnetization decreases for all compositions with the substitution of these elements.     

Steady temperature field associated with the flow of gassy oil in a porous medium

The steady thermal field associated with the flow of gassy oil through a porous medium is investigated with allowance for the Joule-Thomson and degassing effects. A formula is obtained for estimating the temperature anomalies at the well bottom on oil inflow intervals which correspond to a bottom pressure lower than the saturation pressure. Ufa. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No.1, pp. 113–116, January–February, 1994.     

Identifiability of finite mixtures using a new transform

Identifiability of finite mixtures of the following families of distributions are proved: Weibull, normal log, chi, pareto and power function.     

Radiolabeling of anti-carcinoembryonic antigen (CEA) monoclonal antibody (MAb BW 431/26) for clinical applications

A method for labeling of anti-carcinoembryonic antigen (CEA) monoclonal antibody (MAb) BW 431/26 is described. For preparations of^99mTc-anti-CEA complex, a solution (1 ml) of tetrasodium-1,1,3,3-propanetetetraphosphate dihydrate (2.7 mg), stannous chloride dihydrate (0.12 mg) and sodium chloride (0.2 mg) in 5 ml of 0.9% saline was added to a vial containing monoclonal antibody (2 mg) from mouse (MAb BW 431/26), D-glucitol (2 mg) and sodium sulfate (2 mg) to obtain a clear solution. A quantitative labeling yield of the MAb BW 431/26 was achieved by addition of 5 ml (40.5 mCi, 1.5 Gbq) technetium-99m-pertechnetate (^99mTcO₄) generator eluate at room temperature within 10 minutes. The radiochemical purity determined by ITLC (Gelman, SG) plates was >95%.     

Radiosynthesis and Biodistribution of <Superscript>99m</Superscript>Tc-Metronidazole as an <Emphasis Type="Italic">Escherichia coli</Emphasis> Infection Imaging Radiopharmaceutical

Bacterial infection poses life-threatening challenge to humanity and stimulates to the researchers for developing better diagnostic and therapeutic agents complying with existing theranostic techniques. Nuclear medicine technique helps to visualize hard-to-diagnose deep-seated bacterial infections using radionuclide-labeled tracer agents. Metronidazole is an antiprotozoal antibiotic that serves as a preeminent anaerobic chemotherapeutic agent. The aim of this study was to develop technetium-99m-labeled metronidazole radiotracer for the detection of deep-seated bacterial infections. Radiosynthesis of ^99mTc-metronidazole was carried by reacting reduced technetium-99m and metronidazole at neutral pH for 30 min. The stannous chloride dihydrate was used as the reducing agent. At optimum radiolabeling conditions, ~ 94% radiochemical was obtained. Quality control analysis was carried out with a chromatographic paper and instant thin-layer chromatographic analysis. The biodistribution study of radiochemical was performed using Escherichia coli bacterial infection-induced rat model. The scintigraphic study was performed using E. coli bacterial infection-induced rabbit model. The results showed promising accumulation at the site of infection and its rapid clearance from the body. The tracer showed target-to-non-target ratio 5.57 ± 0.04 at 1 h post-injection. The results showed that ^99mTc-MNZ has promising potential to accumulate at E. coli bacterial infection that can be used for E. coli infection imaging.     

Steam pre-reforming of natural gas over nanostructured Ni/12CaO–7Al<Subscript>2</Subscript>O<Subscript>3</Subscript> catalyst for hydrogen production: effect of support preparation method

Calcium aluminate (12CaO–7Al₂O₃) powder was synthesized using three methods, viz. Pechini, coprecipitation, and a new novel facile decomposition route starting from activated alumina and calcium nitrate precursors, then used as a support to prepare a series of 31 wt%Ni/12CaO–7Al₂O₃ catalysts by deposition–precipitation method. The resultant catalysts were tested in steam pre-reforming of natural gas at 400–550 °C, low steam-to-carbon (S/C) molar ratio of 1.5, and atmospheric pressure. The obtained samples were characterized by Brunauer–Emmett–Teller (BET) analysis, scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis, temperature-programmed reduction (TPR), temperature-programmed oxidation (TPO), hydrogen chemisorption, and CO₂–temperature-programmed desorption (TPD). Experimental results showed that the basicity and morphology of the supports depended significantly on the synthesis method. Calcium aluminate synthesized using the new decomposition procedure showed surface area of 6.23 m² g^?1, while the surface area of those prepared by the Pechini and coprecipitation method were 1.38 and 3.76 m² g^?1, respectively. The catalytic properties of the 31 wt%Ni/12CaO–7Al₂O₃ catalysts were strongly influenced by the support preparation approach. The highest specific surface area (about 230 m² g^?1), smallest Ni particle size (8.86 nm), and highest nickel dispersion (7.48%) were observed for the catalyst whose support was synthesized by the decomposition method. Even at high gas hourly space velocity (GHSV) of 2 × 10⁵ mL \({\text{g}}^{ - 1}_{\text{catalyst}}\) h^?1, this catalyst exhibited around 100% C₂H₆ and C₃H₈ conversion at temperature above 500 °C. High catalytic stability during 60 h time on-stream was also shown. The TPO profiles of the spent catalyst demonstrated high resistance to carbon formation.