合成二氧化氯的催化剂和方法及该催化剂的制备

使用一种失活速率降低的催化剂用亚氯酸钠的水溶液合成二氧化氮。催化剂最好为钯，钯与其它钯系金属的混合物（如Ｐｂ＋Ｐｔ）或者是钯与第１副族金属的混合物（Ｐｂ＋Ａｕ），所用的载体为可用第１主族金属的硕酸盐如（Ｋ２ＣＯ３）、第２主族金属的碳酸盐（如ＣａＣＯ３）或者是可转化成ＭｇＯ的镁盐改性的物质，载体还可以是第１主族金属的碳酸盐（如Ｋ２ＣＯ３）或者是可转化成ＭｇＯ的镁盐改性的物质，载体还可以是第１主族金属     

Genomic organization, fine-mapping, and expression of the human islet-brain 1 (IB1)/c-Jun-amino-terminal kinase interacting protein-1 (JIP-1) gene

Islet-brain 1 (IB1), a regulator of the pancreatic beta-cell function in the rat, is homologous to JIP-1, a murine inhibitor of c-Jun amino-terminal kinase (JNK). Whether IB1 and JIP-1 are present in humans was not known. We report the sequence of the 2133-bp human IB1 cDNA, the expression, structure, and fine-mapping of the human IB1 gene, and the characterization of an IB1 pseudogene. Human IB1 is 94% identical to rat IB1. The tissue-specific expression of IB1 in human is similar to that observed in rodent. The IB1 gene contains 12 exons and maps to chromosome 11 (11p11.2-p12), a region that is deleted in DEFECT-11 syndrome. Apart from an IB1 pseudogene on chromosome 17 (17q21), no additional IB1-related gene was found in the human genome. Our data indicate that the sequence and expression pattern of IB1 are highly conserved between rodent and human and provide the necessary tools to investigate whether IB1 is involved in human diseases.     

Segmental antigen challenge increases fibronectin in bronchoalveolar lavage fluid

Fibronectin may contribute to asthma pathogenesis by recruitment and activation of inflammatory cells, and by promotion of subepithelial fibrosis. Fibronectin is produced by several types of airway cells, including epithelial cells, fibroblasts, and alveolar macrophages. To test the hypothesis that antigen-induced airway inflammation is associated with increased local generation of fibronectin, segmental bronchoprovocation (SBP) with antigen and saline was performed in 17 atopic patients. Bronchoalveolar lavage (BAL) was performed at 5 min and 48 h after segmental challenge with saline or antigen. Fibronectin concentrations in BAL fluid, measured by enzyme-linked immunosorbent assay (ELISA), increased more than 5-fold 48 h after antigen challenge (65 [47 to 110] versus 407 [240 to 697] ng/ml, median and 25 to 75% interquartiles, p < 0.05). Fibronectin concentrations 48 h after antigen challenge correlated with histamine concentrations 5 min after antigen challenge and numbers of eosinophils, neutrophils, macrophages, and total cells in BAL fluid 48 h after antigen challenge. BAL was more enriched in fibronectin 48 h after challenge than would be predicted solely from increased permeability of plasma proteins. Western blot analysis showed that fibronectin in BAL fluid was largely intact and contained the extra domain-A (ED-A) splice variant of cellular fibronectin, indicative of local production. We conclude that antigen challenge in atopic subjects causes increased production of fibronectin by airway cells and speculate that this response may contribute to airway remodeling in allergic inflammation.     

Enantioselective dehydration of butan-2-ol using zeolite Y modified with dithiane oxides: comments on the nature of the active site

Modification of zeolite H-Y by dithiane oxides (2-R-1,3-dithiane 1-oxide, R = H, CH₃, C₆H₅) is shown to enhance significantly its activity for the acid-catalysed gas phase dehydration of butan-2-ol. The rate enhancement is observed for catalysts that are prepared using two commercial samples of zeolite H-Y. The origin of this effect is examined using in situ FTIR spectroscopy and ²⁷Al and ²⁹Si MAS NMR spectroscopy studies of the modified zeolite. The rate enhancement is considered to result from a specific interaction between the dithiane oxide modifier with both the extra-framework and framework aluminium in the zeolite. This revised version was published online in July 2006 with corrections to the Cover Date.     

Insulin receptors are widely distributed in human brain and bind human and porcine insulin with equal affinity

Insulin receptors differing structurally from those in other tissues have been demonstrated in brain from many species. Subtle differences in binding properties have been reported between insulin receptors in brain and other tissues, including differences in affinity of pig brain receptors for human and porcine insulin. Insulin binding has been demonstrated in human cerebral cortex, but insulin binding has not been characterized in other areas of human brain. We have studied the binding of 125I labelled human insulin, and its displacement by unlabelled human and porcine insulin, in homogenates prepared from human hypothalamus, cerebral cortex and cerebellum obtained post-mortem from eight non-diabetic subjects. Specific binding was demonstrated in all brain regions studied, and displacement curves obtained with unlabelled human and porcine insulin were identical. By contrast, unlabelled insulin-like growth factor-1 did not significantly displace 125I labelled human insulin over the same concentration range. We therefore conclude that insulin receptors are widely distributed in human brain and do not differ in their affinity for human and porcine insulin.     

Managed obstetrical care

BACKGROUND: Infertility is common in Africa, but virtually no data exist on HIV prevalence among infertile women. Mainly anthropological studies in Africa have shown that infertile women have higher risks of marital instability and possibly also have more sexual partners than fertile women. METHOD: This study was conducted in a hospital in northwest Tanzania during 1994 and 1995. Women presenting themselves with infertility problems to the outpatient clinic were interviewed, examined and blood was drawn. Women who came to deliver in the hospital, excluding primiparae, were taken as a control group. The analysis was limited to women > or = 24 years. In total 154 infertile and 259 fertile women were included in the study. RESULTS: HIV prevalence was markedly higher among infertile women than among fertile women: 18.2% and 6.6% respectively (adjusted odds ratio [OR] for age, residence and occupation 2.7; 95%-confidence interval [CI]: 1.4-5.3). Data on past sexual behaviour showed that infertile women had more marital breakdowns, more lifetime sexual partners and a higher level of exposure to sexually transmitted diseases (STD). CONCLUSION: Women with fertility problems appear to have higher HIV prevalence, which justifies more attention for such women in the context of AIDS programmes. In addition, caution is needed when using sentinel surveillance data from antenatal clinics to monitor HIV prevalence.     

Lysosomal targeting of P-selectin is mediated by a novel sequence within its cytoplasmic tail

Signals controlling the intracellular targeting of many membrane proteins are present as short sequences within their cytoplasmic domains. P-selectin is a type I membrane protein receptor for leukocytes, acting during the inflammation response. Heterologous expression experiments have demonstrated that its 35-residue cytoplasmic tail contains signals for targeting to synaptic-like microvesicles, dense-cored granules, and lysosomes. We have examined the lysosomal targeting information present within the cytoplasmic tail by site-directed mutagenesis of horseradish peroxidase-P-selectin chimeras followed by transient transfection in H.Ep.2 cells. Assaying lysosomal targeting by subcellular fractionation as well as intracellular proteolysis, we have discovered a novel lysosomal targeting signal, KCPL, located within the C1 domain of the cytoplasmic tail. Alanine substitution of this tetrapeptide reduced lysosomal targeting to the level of a tailless horseradish peroxidase-P-selectin chimera, which was previously found to be deficient in both internalization and delivery to lysosomes. A proline residue within this lysosomal targeting signal makes a major contribution to the efficiency of lysosomal targeting. A diaminobenzidine density shift procedure established that chimeras with an inactivated KCPL sequence are present within transferrin-positive compartments. Such a mutant also displays an increased level of expression at the plasma membrane. Our results indicate that the sequence KCPL within the cytoplasmic tail of P-selectin is a structural element that mediates sorting from endosomes to lysosomes.