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91.
Four simple, accurate, sensitive and economical procedures (A–D) for the estimation of gentamicin sulphate and vancomycin hydrochloride, both in pure form and in pharmaceutical formulations have been developed. The methods are based on the oxidation of the studied drugs by a known excess of potassium permanganate in sulphuric acid medium and subsequent determination of unreacted oxidant by reacting it with amaranth dye (method A), acid orange II (method B), indigocarmine (method C) and methylene blue (method D), in the same acid medium at a suitable λmax=521, 485, 610 and 664 nm, respectively. The reacted oxidant corresponds to the drug content. Regression analysis of Beer-Lambert plots showed good correlations in the concentration ranges 4–8, 3–8, 4–9 and 5–9 μg ml−1 with gentamicin and 4–8, 1.5–4, 1.5–4 and 3.5–5.5 μg ml−1 with vancomycin for methods A, B, C, and D, respectively. The molar absorptivity, sandell sensitivity, detection and quantification limits were calculated. The stoichiometric ratios for the cited drugs were studied. The optimum reaction conditions and other analytical parameters were evaluated. The influence of the substance commonly employed as excipients with these drugs were studied. The proposed methods were applied to the determination of these drugs in pharmaceutical formulations. The results have demonstrated that the methods are equally accurate and reproducible as the official methods.  相似文献   
92.
In this article we investigate the frame properties and closedness for the shift invariant space Vp(F) = { ?i=1r ?j ? \Zd di(j) fi (·-j):  ( di(j) )j ? \Zd ? lp }, \q 1 £ p £ ¥ . \displaystyle V_p(\Phi) = \left\{ \sum_{i=1}^r \sum_{j\in \Zd} d_i(j) \phi_i (\cdot-j): \ \left( d_i(j) \right)_{j\in \Zd}\in \ell^p \right\}, \q 1\le p \le \infty~. We derive necessary and sufficient conditions for an indexed family {fi(·-j): 1 £ ir, j ? \Zd}\{\phi_i(\cdot-j):\ 1\le i\le r, j\in \Zd\} to constitute a pp-frame for Vp(F)V_p(\Phi), and to generate a closed shift invariant subspace of LpL^p. A function in the LpL^p-closure of Vp(F)V_p(\Phi) is not necessarily generated by lp\ell^p coefficients. Hence we often hope that Vp(F)V_p(\Phi) itself is closed, i.e., a Banach space. For p 1 2p\ne 2, this issue is complicated, but we show that under the appropriate conditions on the frame vectors, there is an equivalence between the concept of pp-frames, Banach frames, and the closedness of the space they generate. The relation between a function f ? Vp(F)f \in V_p(\Phi) and the coefficients of its representations is neither obvious, nor unique, in general. For the case of pp-frames, we are in the context of normed linear spaces, but we are still able to give a characterization of pp-frames in terms of the equivalence between the norm of ff and an lp\ell^p-norm related to its representations. A Banach frame does not have a dual Banach frame in general, however, for the shift invariant spaces Vp(F)V_p(\Phi), dual Banach frames exist and can be constructed.  相似文献   
93.
Some times high uranium contents are present in the phosphate rocks used for the manufacturing of fertilizer. In view of the harmful effects on human health due to the processing and use of such fertilizers in agriculture, it is important to analyse phosphate rocks for uranium content determination. Ten representative rock samples from Kakul phosphate deposit exposed near Abbotabad, Pakistan which are used for the manufacturing of fertilizers were studied for uranium content determination with the help of fission track and neutron activation analysis techniques. Each sample was split into three parts. The first and second parts (solid slabs and pellets) were subjected to fission track analysis, while the third part was analysed using neutron activation analysis technique for comparison. On the average a uranium content of 37 ppm was found in the phosphate rocks. The results of uranium content determinations with the help of fission track and neutron activation analysis techniques show a remarked resemblance up to ±0.1%. This indicates that the fission track analysis technique of uranium content determination is a reliable method inspite of its simplicity. The uranium content in the Kakul deposits is within the permissible limit allowed for the mining and processing of the phosphate rocks for the manufacturing of fertilizers.  相似文献   
94.
The high prevalence of cancer has been increased the rate of studying about the new formulation of chemotherapeutic drugs. In this regards, one of the suitable options is the use of metal nanoparticles for formulating these drugs. In the recent study, Lens culinaris seed aqueous extract conjugated gold nanoparticles (AuNPs) are reported for the first time to exert a dietary therapeutic potential compared to mitoxantrone in an animal model of acute myeloid leukemia. The synthesized AuNPs were characterized using different techniques including UV–Vis., FT-IR, XRD, FE-SEM, and TEM. DPPH free radical scavenging test was done to evaluate the antioxidant potentials of HAuCl4, L. culinaris, AuNPs, and mitoxantrone. For the analyzing of cytotoxicity effects of HAuCl4, L. culinaris, AuNPs, and mitoxantrone, MTT assay was used on HUVEC, 32D-FLT3-ITD, Human HL-60/vcr, and Murine C1498 cell lines. In vivo assay, induction of acute myeloid leukemia was done by 7,12-Dimethylbenz[a]anthracene (DMBA) in 75 mice. Then, the animals were randomly divided into six subgroups, including control, untreated, HAuCl4, L. culinaris, AuNPs, and mitoxantrone. SEM and TEM images showed uniform spherical morphology and average diameters of 10–40 nm for the nanoparticles. DPPH test revealed similar antioxidant potentials for mitoxantrone and AuNPs. Similar to mitoxantrone, AuNPs had low cell viability dose-dependently against 32D-FLT3-ITD, Human HL-60/vcr, and Murine C1498 cell lines without any cytotoxicity on HUVEC cell line. AuNPs and mitoxantrone significantly (p ≤ 0.05) reduced the weight and volume of liver and spleen, the pro-inflammatory cytokines, and the total WBC, blast, neutrophil, monocyte, eosinophil, and basophil counts and increased the mRNA expression of Sphingosine-1-phosphate receptor-1 and Sphingosine-1-phosphate receptor-5, the anti-inflammatory cytokines, and the lymphocyte, platelet, and RBC parameters as compared to the untreated mice. It looks that AuNPs can be administrated as a chemotherapeutic supplement or drug for the treatment of acute myeloid leukemia in the clinical trial.  相似文献   
95.
A single-step solution-based strategy is used to obtain 2D Janus-like free-standing ultrathin nanosheets build from two structurally unrelated species, that is, polyoxomolybdate (POM) and CoO. A controlled 2D-to-1D morphological transition was achieved by judiciously adjusting the solvent choice. These POM-CoO heterostructures can behave as an ideal catalyst for the epoxidation of styrene. Benefiting from their amphiphilic nature, these 2D POM-CoO nanosheets have also been used as surfactant to emulsify immiscible solvents. It is anticipated that structurally diverse polyoxometalates will offer promise as design elements for variety of structurally and compositionally tunable van der Waals integrated heteromaterials having a broad range applications.  相似文献   
96.
The first continuous production system of laminaribiose from sucrose and glucose in a bienzymatic reaction is reported in this study. Immobilized laminaribiose phosphorylase and sucrose phosphorylase were used in a packed bed reactor system comprising of a 3-cm glass column at 35 °C with a steady feeding flow rate of 0.1 ml/min. Factors affecting product formation including enzyme ratio, peal concept (both enzymes in one pearl or in separate pearls), and pearl size were studied. An enzyme ratio of 2:1 of laminaribiose phosphorylase (LP) to sucrose phosphorylase (SP) when encapsulated separately in bigger size peals resulted in higher concentration of product. Laminaribiose (0.4 g/(L h)) is produced in the optimized system at steady state. The reaction system proved to be operationally stable throughout 10 days of continuous processing. A half-life time of more than 9 days was observed for both biocatalysts.  相似文献   
97.
The European Physical Journal C - Much theoretical effort and automatization are required to confront new physics models with experimental data for many types of particle reactions at future...  相似文献   
98.
99.
Using the Hubbard model in the framework of the tight-binding formulation, we studied the effects of the electron–electron (e–e) interaction on the indirect magnetic exchange coupling between the magnetic impurities embedded in triangular graphene nanoflakes. The results show that the magnitude of the coupling enhances in the presence of the e–e interaction and Rashba spin–orbit interaction (RSOI). The RKKY coupling magnitude depends on the impurity positions in nanoflake and the size of the system, as well.  相似文献   
100.
Novel pyrimido[4,5-b]quinoline-tetraones were prepared by the three-component reaction of 2-hydroxynaphthalene-1,4-dione, 6-amino-uracils, and aromatic aldehydes in aqueous media and catalyzed by p-toluenesulfonic acid. This protocol provides a simple one-step procedure with the advantages of easy workup, good yield of products, and environmental friendliness.  相似文献   
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