磷酸铵在(NH_4)_3PO_4-(NH_4)_2WO_4-NH_4OH-H_2O系中溶解度研究

采用等温结晶法研究了磷酸铵在(NH_4)_3PO_4-(NH_4)_2WO_4-NH_4OH-H_2O系中的溶解度。结果表明:低温、高氨浓度下(NH_4)_3PO_4-(NH_4)_2WO_4-NH_4OH-H_2O系中磷酸铵的溶解度非常小,易溶的磷酸铵表现出难溶的特征。温度10℃、氨含量15.6%(质量分数)时,磷酸铵的溶解度可低至0.02%(质量分数,P_2O_5);钨酸铵浓度对磷酸铵溶解度的影响很小;白钨矿磷酸铵分解液氨盐析-冷却结晶回收磷酸铵过程钨基本不结晶析出。研究结果为白钨矿磷酸铵分解液高效回收磷酸铵和初步脱磷奠定了理论基础。     

Structure and Luminescent Enhancement Effect of Na_5Eu(MoO_4)_4 by Doping(WO_4)~(2-)

The luminescent enhancement effect of Na_5Eu(MoO_4)_4 by doping(WO_4)~(2-) has been studied.When the value x in Na_5Eu(Mo_(1-x)W_xO_4)_4 is in 0相似文献   

Molecular modelling of (A4T4NN)n and (T4A4NN)n: sequence elements responsible for curvature

The molecular modelling program JUMNA has been used to investigate the origins of the strikingly different curvature of the two sequences, (A4T4NN)n and (T4A4NN)n. Gel electrophoresis and cyclisation studies have shown that only the former of these two sequences is significantly curved. By developing novel superhelical symmetry constraints we were able to study the energetic and structural aspects of polymeric DNA having a controlled curvature. The results obtained (which do not take into account specific hydration effects) correlate well with the experimental data and offer a molecular level explanation of curvature. Although curvature is found to be initiated by specific dinucleotide junctions, deformations spread to surrounding dinucleotide steps and, moreover, sequence effects beyond the dinucleotide level are observed.     

Preparation and antirheumatic activity of optically active 2-acetylthiomethyl-4-(4-methylphenyl)-4-oxobutanoic acid (KE-298)

2-Acetylthiomethyl-4-(4-methylphenyl)-4-oxobutanonic acid (KE-298) is an antirheumatic agent. To elucidate the effects of optically active KE-298, we resolved the racemic acid and obtained the two optical isomers. (+)-KE-298 was converted to the 4-bromobenzyl ester derivative and the absolute structure was confirmed as (S) by X-ray crystallographic analysis. The pharmacological activities of the optical isomers and racemic KE-298 were compared by using the characteristic tests for KE-298. Though (+)-KE-298 showed a stronger suppressive effect on rat adjuvant arthritis than (-)-KE-298, no difference between the two isomers was detected in in vitro tests (enhancing effect on lymphocyte transformation, IL-1 antagonistic effect).     

THE CaSO4-CaO-Ca3(AsO4)2 PHASE DIAGRAM

Abstract

The phase diagram of the CaSO₄-Ca₃(AsO₄)2-CaO system was measured by differential thermal analysis and by an equilibration and quenching technique. A thermodynamic model was developed giving the Gibbs energy of every phase as a function of temperature and composition. A new ternary compound was observed with a composition near Ca5As2SO13. The Modified Quasichemical Model was used for the liquid solution. Optimized model parameters were obtained by assessing of all available thermodynamic and phase equilibrium data. The model reproduces all the data within experimental error limits. The model was used to calculate the liquidus surface over the temperature range of industrial interest.

Le diagramme de phases CaSO₄-Ca₃(AsO₄)2-CaO a été mesuré par analyse thermique différentielle et par une technique d’équilibration et de trempe. Un modèle thermodynamique a été développé donnant l’énergie de Gibbs pour toutes les phases dans ce système en fonction de la température et de la composition. Une nouvelle phase solide a été observée ayant une composition proche du Ca5As2SO13. La dernière version du modèle quasichimique a été utilisée pour la phase liquide. Les paramètres du modèle ont été obtenus par optimisation en tenant compte de toutes les données thermodynamiques et d’équilibres de phases disponibles pour ce système. Le modèle reproduit toutes les données à l’intérieure des erreurs expérimentales. Le modèle a été utilisé pour calculer la projection du liquidus du système CaSO₄-Ca₃(AsO₄)2-CaO à des températures pouvant être utilisées dans l’industrie.     

Serum interleukin-6 (IL-6) and interleukin-4 (IL-4) in patients with multiple myeloma (MM)

In this study we determined, in patients with multiple myeloma (MM), serum levels of IL-4 and IL-6 at diagnosis and during the course of the disease, seeking a correlation with disease activity and prognosis. We studied 54 MM patients, 41 of whom responded to chemotherapy whilst 11 were resistant. At diagnosis, IL-6 was increased in 66% of patients (median 35.5 pg/ml) whereas IL-4 was low (median 4 pg/ml) in 75% of patients. In responding patients, IL-4 increased in remission (median 25 pg/ml), whereas IL-6 decreased (median 4 pg/ml). In chemotherapy-resistant patients, IL-6 and IL-4 values remained stable during the course of the disease.