Structure and reactivity of free radicals trapped in mechanically degraded poly(vinylene carbonate)

Poly(vinylene carbonate) has been mechanically degraded. The structure and the reactivity of polymer radicals have been studied over the temperature range between ?70°C and 150°C. At ?70°C the following radicals are present:

The hyperfine splitting constants are: (I), a_H = 1.96 mT and a_H = 3.34 mT; (II), a_H¹ = 3.2 mT; (III), a_H = 1.25mT and a_H = 1.75mT. At +70°C, new radicals occur and the total spectrum becomes asymmetrical.     

Quantitation of cell-associated doxorubicin by high-performance liquid chromatography after enzymatic desequestration

In a double blind study of 58 episodes of fever and profound neutropenia, children with cancer received either recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) or placebo, combined with identical antimicrobial therapy, i.e. imipenem, on admission. The criteria for discontinuation of therapy were identical. A difference was demonstrated both in the number of hospital days, totaling 252 days in the rhGM-CSF group and 354 in the placebo group, days receiving antibiotics (220 vs. 322), and in the resolution of neutropenia (4.5 days vs. 6.0 days; P < 0.05). The number of episodes requiring antimicrobial therapy for longer than 10 days was 5 of 28 (12%) in the rhGM-CSF group as opposed to 15 of 30 (50%) in the placebo group (P = 0.01). rhGM-CSF was well-tolerated. We conclude that rhGM-CSF was efficacious in accelerating myeloid recovery and reducing the length of hospitalization in febrile neutropenia.     

Synthesis of 1′-Aryl-1,3′-bi-β-carbolines and Their Saturated Counterparts

1-Aryl-β-carboline-3-carbaldehyde building blocks have been used as the starting materials for the synthesis of novel bis-β-carboline derivatives. In the two-step synthesis the Pictet–Spengler reaction was used before the dehydrogenation of the polycyclic compound to the aromatic derivatives.     

Deposition of hydroxyapatite and tricalcium phosphate coatings by suspension plasma spraying: Effects of torch speed

This research focuses on the deposition of hydroxyapatite (HA) and tricalcium phosphate (TCP) coatings produced by suspension plasma spraying (SPS) using in-house liquid feedstock suspensions. The work studied the effects of torch speed on the thickness, microstructure, and crystalline composition of the coatings. SPS allowed the deposition of HA and TCP coatings with thickness between 28 and 90?μm. The coatings presented lamellar microstructure with complex porosity between the splats. Micropores ranging from 0.2 to 6?μm and close mesopores, from 8 to 45?μm, had a spherical morphology and were homogenously distributed within the coatings. Water evaporation during SPS allowed the retention of pure and crystalline HA coatings. In contrast, the presence of water molecules led to the formation of HA as a secondary phase in the TCP coatings, which formed α-TCP as the major component due to the high temperature reached by the powder during deposition.     

Green synthesis of silver nanoparticles and biopolymer nanocomposites: a comparative study on physico-chemical,antimicrobial and anticancer activity

The current report was intended towards comparative study of green-synthesized biogenic Rhubarb silver nanoparticles (RS-AgNPs) and chitosan crosslinked silver nanocomposites (CSHD-AgNCs). The physico-chemical characterization was done by UV–visible, FTIR, scanning electron microscopy (SEM), transmission electron microscopy (TEM), EDX, TGA, XRD and zeta potential (\(\zeta \)). The analysis and spectroscopic characterization was done by SEM and TEM and their results reveal that the nanoparticles are spherical in shape, with average size ranges from 5 to 50 nm, and was gathered by face centered cubic (FCC) structure throughout the polymer matrix and stable without any protecting or capping reagents over 450 days. The antimicrobial property of RS-AgNPs and CSHD-AgNCs (\(\zeta = +29.6\) and \(+\)32.8 mV) was evaluated against E. coli and S. aureus and showed an effective inhibitory property. The RS-AgNPs and CSHD-AgNCs were assessed for their anticancer activity against HeLa cell line by MTT method, and it reveals a dose–response activity, time and cell line-dependent cytotoxicity. Based on the results obtained, the RS-AgNPs exhibited higher toxicity over CSHD-AgNCs after 24 h incubation of HeLa cells with different concentrations and is negligible for the aqueous Rhubarb extract. It was concluded that the changes in anticancer activity towards HeLa cells due to biological activity of silver nanoparticles depend on their method of biosynthesis and their physico-chemical nature.     

Relation of the saprobic index to BOD5

Equations and graphs were shown demonstrating the relation of the enlarged saprobic index S to mean values of BOD₅. Two sets of constants had to be calculated, as there is an important break on the line (Fig. 3) dividing the aerobic and anaerobic environment. This break occurs near BOD₅ = 50 mg l⁻¹ and S = 4·5.     

The diuretic effect of borocaptate sodium in rats and in patients with brain tumors

Kidney function changes after single-dose administration of borocaptate sodium were studied in rats and in patients with brain tumors. Changes of glomerular filtration rate (GFR) measured as 14C-inulin clearance and urine flow rate (UFR) after a slow intravenous injection of BSH (25 and 50 mg/kg b.w., respectively) were investigated in rats under pentobarbital anesthesia. The effect of BSH has been compared with that of its disulfide (BSSB) which is spontaneously generated by oxidation of BSH during storage. It was found that BSH decreases GFR in relation to dose and, in the same way, causes a temporary increase of UFR. On the other hand, BSSB (50 mg/kg) induced a large reversible decrease of GFR as well as a decrease of urine excretion. Measurements of GFR (inulin clearance), renal plasma flow (PAH clearance) and urine excretion were taken in a group of patients with brain tumors in which boron disposition after an infusion of BSH (25 mg/kg b.w. over 1 h) had been studied. An increase in urine production was the dominant effect (up to 200% of the initial value), with the alterations of GFR and RPF being of minor significance except in one patient with a GFR reduction up to almost 50% the original value. Kidney function changes after BSH or BSSB administration are supposedly related to the high retention of BSH in kidney.