高效率平面磁控溅射器的研制

介绍一种新型磁控溅射装置。它采用两块极性相对的环状磁铁的设计方法，通过扩大靶表面的等离子放电区域面积，使传统磁控溅射枪使用中经常受到的两个限制──溅射速率与靶的利用率得到了较大的改善。实验中铜靶在溅射功率密度为11W／cm~2时溅射速率约为800nm／min，如果继续提高功率则可获得更高的速率。而靶的利用率可达64％左右。另外，在认为出射粒子符合cos~nθ分布的前提下，发现当n＝3．3时，实验数据和理论数据符合得较好。     

PET／PC共混物的辐射效应研究

研究了经溶液共混制备的聚对苯二甲酸乙二醇酯／聚碳酸酯（ＰＥＴ／ＰＣ）共混物的辐射效应。结果表明：ＰＥＴ／ＰＣ共混物在辐照过程中未发生酯交换反应和交联反应，但有降解反应发生。在研究的剂量范围内，辐照对ＰＥＴ／ＰＣ共混物中ＰＥＴ和ＰＣ的晶体形态影响不明显。     

Agenesis of the corpus callosum in a mother and son

Most reported familial cases of agenesis of the corpus callosum have followed either an autosomal recessive or an X-linked recessive pattern of inheritance. To the best of our knowledge, there is only one previous report of a family showing clear-cut autosomal dominant inheritance. We present the second such family, among whom a mother and her son had moderately severe coordination problems and low-normal intelligence. We suggest that agenesis of the corpus callosum, when transmitted as an autosomal dominant trait, is clinically characterized by a relatively milder phenotype than that occurring when inheritance is either autosomal or X-linked recessive and may be more common than has been thought.     

Linear B-cell epitopes in the N-terminus of L2 of bovine papillomavirus type 4

In vivo dosimetry performed with semiconductor detectors is a reliable method for patient dose control. The purpose of this study is to evaluate the perturbations introduced in the patient's absorbed dose distribution by three types of commercially available diodes (Isorad, Sun Nuclear Corp.; model 114200, 114300 and 114400) from the same company and to present possible solutions for minimizing this side-effect.     

Inefficiency of lactation in primiparous rats: the costs of first reproduction

To investigate the energetic costs of lactation in a female mammal in relation to previous reproductive history, we compared the performance of adult female Long-Evans rats that had previously bred (multiparous) with young females that had not previously given birth (primiparous). All litters were standardized to 10 +/- 1 young. We compared maternal production (growth of pups), body mass, and energy intake (food consumption) of mothers, as well as their energy expenditure (resting oxygen consumption). The mass of litters at birth and the growth of pups during lactation did not differ according to reproductive history of the mothers. The body mass of primiparous mothers was less than that of multiparous mothers, and primiparous mothers showed an increase in mass during early lactation. To accomplish the essentially identical production of offspring under these circumstances, the primiparous mothers consumed and expended more energy than the multiparous mothers. This remarkable performance of first-time mothers results in an overall efficiency of energy allocation to reproduction amounting to only 25%, compared with 38% in multiparous mothers. The energetic inefficiency of primiparous female lactation results largely from the excessive expenditures associated with physiological and behavioral performances of first-time reproduction, together with a small component of additional expenditure due to further growth by the primiparous mothers. We suggest that this inefficiency probably contributes to the observed low reproductive success of novice breeders; furthermore, active restraint of fecundity may be an evolutionary response to the constraints of the energetic inefficiency of primiparous breeding by female mammals.     

Mechanisms of virus assembly probed by Raman spectroscopy: the icosahedral bacteriophage P22

A microdialysis flow cell has been developed for time-resolved Raman spectroscopy of biological macromolecules and their assemblies. The flow cell permits collection of Raman spectra concurrent with the efflux of small solute molecules into a solution of macromolecules and facilitates real-time spectroscopic detection of structural transitions induced by the effluent. Additionally, the flow cell is well suited to the investigation of hydrogen-isotope exchange phenomena that can be exploited as dynamic probes of viral protein folding and solvent accessibility along the assembly pathway. Here, we describe the application of the Raman dynamic probe to the maturation of the icosahedral capsid of bacteriophage P22, a double-stranded DNA virus. The P22 virion is constructed from a capsid precursor (procapsid) consisting of 420 coat subunits (gp5) in an outer shell and a few hundred scaffolding subunits (gp8) within. Capsid maturation involves expulsion of scaffolding subunits coupled with shell expansion at the time of DNA packaging. Raman static and dynamic probes reveal that the scaffolding subunit is highly alpha-helical and highly thermolabile, and lacks a typical hydrophobic core. When bound within the procapsid, the alpha-helical fold of gp8 is thermostabilized; however, this stabilization confers no apparent protection against peptide NH-->ND exchange. A molten globule model is proposed for the native scaffolding subunit that functions in procapsid assembly. Accompanying capsid expansion, a small conformational change (alpha-helix-->beta-strand) is also observed in the coat subunit. Domain movement mediated by hinge bending is proposed as the mechanism of capsid expansion. On the basis of these results, a molecular model is proposed for assembly of the P22 procapsid.     

Memory-related changes of nitric oxide synthase activity and nitrite level in rat brain

The changes of nitric oxide synthase (NOS) activity and nitrite level in rat brain regions after spatial learning were investigated. NOS activity was assayed by conversion of [3H]L-arginine to [3H]L-citrulline, and a sensitive fluorometric assay for quantification of nitrite was used. Compared with sham-trained rats, NOS activity and nitrite level in hippocampus and cortex, and also the nitrite level in cerebellum, was elevated significantly one day after rats had learnt a water-rewarded spatial alteration task. These results suggest a spatial memory-related changes of endogenous NO in rat brain, and support the idea that NO participates in learning and memory processes.     

发展创新民族风格的包装设计

首先揭示出民族风格是与时代风格对立统一、相互依存的一个概念。因而特定的时代需要具有时代精神的民族风格──创新民族风格。在探索此风格的过程中．我们首先要学习日本的战略，然后在学习的基础上实现超越。     

Classification of the effectiveness of combination treatments

According to FDA regulations, a combination drug is not efficacious unless each component contributes to the claimed effects. For a univariate endpoint, this implies that the combination at specific doses must be superior to each of its components at the same doses. More demanding is the property of synergy, in which the effect of the combination must be superior to the effect expected based on those of its components. If it is equal to those effects, it is additive, and if it is inferior, it is antagonistic. We give regions in the combination dose plane where these concepts are well defined. If the effect of the combination is greater than the greatest effect achievable by any of its components it is therapeutically synergistic. A combination can be antagonistic, yet its components can still contribute to the claimed effects. If it is additive, synergistic or therapeutically synergistic, its components must contribute to the claimed effects. We relate these concepts and provide designs and sequential procedures for determining whether a combination is therapeutically synergistic, synergistic, additive, antagonistic and contributing or antagonistic and non-contributing.     

Bone SPECT of the jaws after fracture, onlay osteoplasty of insertion of implants

AIM: The aim of this study was early differentiation between uncomplicated and complicated processes of healing in the jaw using bone SPECT. METHODS: Investigations were performed in 40 mandibular fractures and 26 jaws after onlay osteoplasty as well as secondary insertion of implants. Bone SPECT was carried out within 1-2 months and after approximately 4-5 months. The uptake in the jaw was assessed semi-quantitatively using ROI analysis. RESULTS: Fractures with uncomplicated healing showed a decrease of uptake in follow-up, whereas fractures with an infection in the later course showed an increase, resulting in a significantly higher uptake at the follow-up investigation for the latter group. 1-2 months after onlay osteoplasty significantly lower uptake was found in regions with later occurrence of sequestration. In regions with implants in which osseointegration failed, there was significant reduction of uptake initially and significant elevation at the follow-up investigation. CONCLUSION: These results indicate a prognostic relevance of bone SPECT in the evaluation of processes of healing in the jaw.