新西兰政府科技投资现状概述

近年来新西兰政府大力调整其科技政策，在建设知识社会的蓝图下，建构了科技投资的基本框架，凸显了知识、经济、环境、社会四大目标，另外通过对投资决策、运行和监督的改革，使政府科技投资的机制更为科学有效，本文还给出了新西兰政府近年来科技投资的分配比例状况，阐明了其投资的重点领域。     

Hypotensive activity of histidine-containing analogues of C-terminal hexapeptide of Substance P

Summary Four new hexapeptide analogues of C-terminal Substance P fragment with increased solubility in aqueous solutions are described. The peptides contain histidine in positions 6, 8, 9 and 10, respectively. The effect of the structural changes on the hypotensive activity and antigenic properties of analogues was compared. It was found that substitution of amino acid residues in various positions in the C-terminal hexapeptide of Substance P resulted in different effects on the hypotensive and antigenic properties, respectively. Only the [His⁶] SP_6-11 analogue had an unchanged antigenic structure when compared with the C-terminal region of Substance P, but it showed an almost total loss of hypotensive activity. The [His⁹] SP_6-11 analogue retained 50% of the hypotensive activity of the C-terminal hexapeptide but showed a markedly reduced expression of the antigenic epitope localized in this region of Substance P.     

Hypotensive activity of histidine-containing analogues of C-terminal hexapeptide of substance P

Four new hexapeptide analogues of C-terminal Substance P fragment with increased solubility in aqueous solutions are described. The peptides contain histidine in positions 6, 8, 9 and 10, respectively. The effect of the structural changes on the hypotensive activity and antigenic properties of analogues was compared. It was found that substitution of amino acid residues in various positions in the C-terminal hexapeptide of Substance P resulted in different effects on the hypotensive and antigenic properties, respectively. Only the [His6] SP6-11 analogue had an unchanged antigenic structure when compared with the C-terminal region of Substance P, but it showed an almost total loss of hypotensive activity. The [His9] SP6-11 analogue retained 50% of the hypotensive activity of the C-terminal hexapeptide but showed a markedly reduced expression of the antigenic epitope localized in this region of Substance P.     

Examination of the fundus of the eye of renal hypertensive dogs

Summary Only 1 of 7 dogs with long-standing renovascular hypertension showed clear changes in the fundus. No distinct retinopathy was seen in the others. Ophthalmoscopy alone is thus of limited value in assessing the progress of benign hypertension in the dog.     

Some aspects of biochemistry of myocardial infarction

This review deals with biochemical changes in infarcted heart muscle. Two main topics are emphasized: changes in substrate metabolism and in myocardial nitric oxide (NO), and prostacyclin and thromboxane formation. Alterations in glucose metabolism in infarcted heart are discussed with special reference to its myocardial utilization in ischemia. The biochemical basis of the increase in NO and prostanoids and the relationship between the enzyme producing nitric oxide (NOS) and cyclooxygenases (COX) responsible for formation of prostanoids are described. The relevance of these findings to clinical conditions and to angiogenesis in heart muscle are stressed.     

羟甲基化对合成木质素改性酚醛胶粘剂性能的影响

采用羟甲基化技术对碱木质素进行活化,对比了羟甲基化前后未质素改性酚醛树脂胶的粘结强度、残留甲醛、贮存稳定性和热稳定性等性能,为木质素的高值应用探讨新的途径.试验结果表明在木质素对笨酚的替代率低于30%务件下,以分离提纯后的木质素可直接应用于酚醛树脂胶粘剂的改性;而当替代率大于50%后,木质素的羟甲基化展示对木质素改性酚醛树脂的胶结强度、热稳定性具有良好的促进作用.但木质素的羟甲基化作用同时也导致木质素改性酚醛树脂中残留甲醛含量增加,进而导致制备的胶粘荆的贮存稳定性降低,可以通过改变合成过程中甲醛和碱的用量来达到降低酚醛树脂中残留甲醛含量.     

Outline of a dynamical inferential conception of the application of mathematics

We outline a framework for analyzing episodes from the history of science in which the application of mathematics plays a constitutive role in the conceptual development of empirical sciences. Our starting point is the inferential conception of the application of mathematics, recently advanced by Bueno and Colyvan (2011). We identify and discuss some systematic problems of this approach. We propose refinements of the inferential conception based on theoretical considerations and on the basis of a historical case study. We demonstrate the usefulness of the refined, dynamical inferential conception using the well-researched example of the genesis of general relativity. Specifically, we look at the collaboration of the physicist Einstein and the mathematician Grossmann in the years 1912–1913, which resulted in the jointly published “Outline of a Generalized Theory of Relativity and a Theory of Gravitation,” a precursor theory of the final theory of general relativity. In this episode, independently developed mathematical theories, the theory of differential invariants and the absolute differential calculus, were applied in the process of finding a relativistic theory of gravitation. The dynamical inferential conception not only provides a natural framework to describe and analyze this episode, but it also generates new questions and insights. We comment on the mathematical tradition on which Grossmann drew, and on his own contributions to mathematical theorizing. The dynamical inferential conception allows us to identify both the role of heuristics and of mathematical resources as well as the systematic role of problems and mistakes in the reconstruction of episodes of conceptual innovation and theory change.     

Effects of fluoride on glycosaminoglycan of cancellous and cortical bone of rabbits

Summary The present report deals with the effect of excessive ingestion of fluoride on glycosaminoglycan (GAG). Increase in fluoride deposition in bone, and in circulating levels of fluoride in serum, are also reported. Among the 3 constituents of GAG investigated; hexosamine, uronic acid and sulphate, the content remained unaltered except for sulphate.Acknowledgment. The authors wish to acknowledge the Department of Science and Technology (DST), Government of India, for the financial aid. One of us (M.J.) acknowledges the receipt of a Junior Research Fellowship from DST, during the tenure of which the investigations were carried out.     

Redox-sensitivity of the dimerization of occludin

Occludin is a self-associating transmembrane tight junction protein affected in oxidative stress. However, its function is unknown. The cytosolic C-terminal tail contains a coiled coil-domain forming dimers contributing to the self-association. Studying the hypothesis that the self-association is redox-sensitive, we found that the dimerization of the domain depended on the sulfhydryl concentration of the environment in low-millimolar range. Under physiological conditions, monomers and dimers were detected. Masking the sulfhydryl residues in the domain prevented the dimerization but affected neither its helical structure nor cylindric shape. Incubation of cell extracts containing full-length occludin with sulfhydryl reagents prevented the dimerization; a cysteine/alanine exchange mutant also did not show dimer formation. This demonstrates, for the first time, that disulfide bridge formation of the domain is involved in the occludin dimerization. It is concluded that the redox-dependent dimerization of occludin may play a regulatory role in the tight junction assembly under physiological and pathological conditions.     

Specificity of action of phospholipases of rat intestinal mucosa]

The total homogenate of rat intestine is devoid of C or D phospholipase activity. At pH 6,5 in the presence of phosphatidylcholines, it exhibits a B phospholipase activity and in the presence of exogen lysophosphatidylcholines an A1 lysophospholipase activity. At pH 8,5 the intestinal mucous membrane of a rat shows an isolated A2 phospholipase activity.     

Measurement of cyclic AMP in the islets of Langerhans of newborn rats. Effect of amino acids]

Radioimmunoassay of cyclic AMP (cAMP) in the islets of Langerhans from 48-64 h old Rats was performed after succinylation of the samples. cAMP was detected at 0.03 nM. The cAMP content of islets increases when L-arginine, L-lysine and L alanine are added together in the incubation medium at a concentration of 5-10 mM each. When phosphodiesterase is inhibited by theophylline the three amino acids considerably increase the cAMP content of islets. Thus an increase in cAMP content of the islets was observed with a concentration of amino acids which is efficient in stimulating the insulin and glucagon secretion.     

Effect of acute and chronic ethanol ingestion on the content of reduced glutathione of various tissues of the rat

Summary The effect of acute ethanol ingestion (5 g/kg) by fasted rats, or chronic treatment in fed animals, revealed a significant decrease in the content of reduced glutathione of the liver and kidney. No changes were observed in reduced glutathione levels of the pancreas, intestines, stomach or spleen in the acute model. In this condition, the time course study of the decrease in reduced glutathione levels showed a progressive effect in the liver and a rapid and constant effect in the kidney.These studies were supported by the Grant M 308-792 from the Servicio de Desarrollo Cientifico, Artistico y de Cooperacion Internacional, Universidad de Chile, and by the Research Associateship Program (L.A.V.) from the Natural Sciences and Engineering Research Council of Canada.     

小鼠皮肤局部缺血模型的建立

目的研究建立稳定的昆明小鼠皮肤局部缺血模型。方法取40只雌性昆明小鼠，随机分为A／B两组，每组20只。分别在小鼠背部建立深达皮下筋膜层的u型皮瓣。A组为3．3×1．5cm皮瓣组．B组为2．5×1．5CITI皮瓣组。皮瓣游离缘垫以医用橡胶，缝合切口，造成皮肤缺血模型，术后观察皮瓣发绀水肿及坏死情况，并用散斑全景实时血流成像仪（MoorFLH）检测皮瓣血流。结果肉眼观察，3．3×1．5cm皮瓣组在术后第2天，50％小鼠皮瓣末端坏死，坏死面积达皮瓣面积的（37．20±4．83）％。术后第3天100％小鼠皮瓣末端坏死。并随时间的延长，坏死面积逐渐扩大。2．5×1．5皮瓣组在术后第1天皮瓣出现发绀，水肿，发绀水肿面积占（77．46±4．51）％，术后第3，第5天发绀水肿区面积逐渐减小，至术后第7天，发绀、水肿完全消退。散斑全景实时血流成像仪（MoorFLPI）检测皮肤血流显示，术后第1天皮瓣显著性缺血（P〈0．05），术后第7天血流基本恢复到术前水平。结论成功建立了昆明小鼠皮肤局部缺血模型，为进一步研究组织微血管再生的机理和策略提供简单而稳定的动物模型。     

Acute toxicity of dimethylnitrosamine in the presence of inhibitors of DMN demethylase.

The LD50 of DMN was determined in groups of mice in the presence of inhibitors of DMN demethylase. Piperonyl butoxide, dibutylnitrosamine and nitrososarcosine had no effect on the acute toxicity of DMN. Diethylnitrosamine and DMN were markedly synergistic. All mice treated with 100 mg/kg diethylnitrosamine and 10.7 mg/kg DMN died. These results suggest that DMN demethylase may not be involved in the acute toxicity of DMN.     

Morphological appearance of fat in the epithelial cells of different portions of the intestines in mice

Summary Absorption of administered fat in the small intestine of mice as judged morphologically in semi-thin sections demonstrates a proximal to distal gradient, being greatest in the mid-jejunal area, but less in the duodenum and ileum. The criterion of the amount and size of fat droplets in intestinal cells, however, does not necessarily give a reliable indication of the efficiency of fat absorption in the different segments of intestine.     

Formation of lipoperoxide in the retina of rabbit exposed to high concentration of oxygen

Summary When rabbit was exposed to high concentration of oxygen, lipoperoxide in the retina was increased at 12 h of the exposure, after which period amplitude of electro-retinogram decreased. The degeneration was observed in the visual cell layer of the retina of the exposed animal. The exposure increased lipoperoxide in isolated retina. These data show the intervention of lipoperoxide in retinal degeneration induced by exposure to high concentration of oxygen.     

Effect of testosterone on the kinetics of the development of suppressor cells in adjuvant arthritis

The induction of unresponsiveness to mycobacterial adjuvant took a longer time in male DA rats than in female rats. A shift in the induction time of unresponsiveness in males toward the female type was brought about by castration, but could be reverted to the male type by the application of testosterone. The transfer study revealed that cells capable of preventing arthritis required a longer incubation time for their development in males than in females. This suggests that testosterone inhibits the development of suppressor cells in adjuvant arthritis.     

Implication of GABA in the spatial organization of the receptive fields of retinal ganglia cells of frogs]

An histoautoradiographic study of the Chicken and Frog retinae was made following an intravitreal injection if tritiated GABA. This amino acid was especially fixed at the amacrine and horizontal cell level. It has been suggested (Werblin, 1974) that horizontal cells might be responsible for the spatial organization of the receptive fields of retinal ganglion cells. GABA could thus be involved in bringing about of the centre-surround arrangement of the latter receptive fields. We have shown that picrotoxin, a specific GABA-antagonist, does indeed provoke marked changes in the activity of retinal ganglion cells. It provokes a decrease in the response threshold, a facilitation of spontaneous activities, and a marked increase in the receptive field area of the ON-OFF ganglion cells: from 12 at the start, it reaches 24 under the effect of picrotoxin.     

The effect of x-irradiation on the amount of dopamine in corpus striatum of the rat.

The effect of ionizing radiation on the amount of dopamine in corpus striatum was investigated in rats exposed to 650 or 850 R of X-rays. The amount of dopamine in the corpus striatum was measured fluorimetrically in various periods of time after irradiation. It was found that, irrespective of the dose applied, the ionizing radiation caused a significant depletion of dopamine in the striatum.     

Activity of two components of serum ribonuclease under conditions of physical exercise

Summary Serum ribonuclease activity before and after physical exercise in healthy persons was estimated. It is found that a work load of 6000 kgm/5 min increased ribonuclease activity measured at pH 8.5 and decreased the activity of the same enzyme measured at pH 7.0 in the presence of ZnSO₄. The observed changes were more pronounced in untrained than in trained persons.