基于多重绘制模型的艺术绘制

为了使得计算机能自动生成表达力丰富的三维场景的艺术绘制，提出了一种基于Shader的多重绘制模型，并采用了多重绘制的协调、参数空间的纹理铺陈、基于色调的表现控制等技术来进行模拟．引入多重绘制可以同时采用对象空间的绘制和图像空间的绘制，通过纹理铺陈描述语言Shader，用户可以定义自己的纹理和笔划来表现三维和二维场景．不同于传统的Shader，基于Shader的多重绘制模型采用光亮度、材质颜色等作为输入，由用户自行决定绘制结果的输入．这一用户可定制性的引入大大增强了艺术绘制的表现能力．该模型已经在一个建筑设计系统中得到实现，以钢笔画为表现媒介的图例表明该模型模拟效果令人满意．     

Tenascin-R inhibits the growth of optic fibers in vitro but is rapidly eliminated during nerve regeneration in the salamander Pleurodeles waltl

Tenascin-R is a multidomain molecule of the extracellular matrix in the CNS with neurite outgrowth inhibitory functions. Despite the fact that in amphibians spontaneous axonal regeneration of the optic nerve occurs, we show here that the molecule appears concomitantly with myelination during metamorphosis and is present in the adult optic nerve of the salamander Pleurodeles waltl by immunoblots and immunohistochemistry. In vitro, adult retinal ganglion cell axons were not able to grow from retinal explants on a tenascin-R substrate or to cross a sharp substrate border of tenascin-R in the presence of laminin, indicating that tenascin-R inhibits regrowth of retinal ganglion cell axons. After an optic nerve crush, immunoreactivity for tenascin-R was reduced to undetectable levels within 8 d. Immunoreactivity for the myelin-associated glycoprotein (MAG) was also diminished by that time. Myelin was removed by phagocytosing cells at 8-14 d after the lesion, as demonstrated by electron microscopy. Tenascin-R immunoreactivity was again detectable at 6 months after the lesion, correlated with remyelination as indicated by MAG immunohistochemistry. Regenerating axons began to repopulate the distal lesioned nerve at 9 d after a crush and grew in close contact with putative astrocytic processes in the periphery of the nerve, close to the pia, as demonstrated by anterograde tracing. Thus, the onset of axonal regrowth over the lesion site was correlated with the removal of inhibitory molecules in the optic nerve, which may be necessary for successful axonal regeneration in the CNS of amphibians.     

Hallucinations, sleep fragmentation, and altered dream phenomena in Parkinson''s disease

Middle ear effusion has been considered the most common cause of vestibular disturbance in children. However, there have been only a few studies on vestibular disturbance in children with otitis media with effusion. We studied the vestibular systems of 30 children with otitis media with effusion aged 8 to 13 years and compared the results with 15 age- and sex-matched controls. A questionnaire relating to vestibular disturbance was given to patients and their parents. Spontaneous nystagmus and positional nystagmus were recorded by electronystagmography as diagnostic tests of the vestibular system. Romberg's and past-pointing tests were performed on children with otitis media with effusion and controls. After vestibular tests were completed, myringotomy was performed, and a ventilation tube was inserted. The questionnaire and the vestibular tests were repeated after the operation and during the first month after surgery. Our study showed that there was a history of vestibular disturbance in 33% of children with otitis media with effusion. Electronystagmography and Romberg's test findings demonstrated that 33% of the children had vestibular dysfunction (p < 0.05). After myringotomy with ventilation tube insertion, vestibular test results returned to normal, and symptoms related to vestibular disturbance improved. These findings confirm the assumption that middle ear effusion may affect the vestibular system, which can be resolved after myringotomy with ventilation tube insertion.     

Xenoislet transplantation: experimental and clinical aspects

Ten diabetic renal transplant patients had porcine fetal islet-like cell clusters (ICC) injected intraportally or placed under the kidney capsule. In some patients, temporary graft survival was achieved, as evidenced by the urinary excretion of small amounts of porcine C-peptide (4 patients) and the identification of some intact insulin-staining cells in a biopsy specimen (1 patient). Glucose metabolism remained unaffected. To improve the results, better islets and better immunosuppressive protocols are required. We found that, while fetal porcine ICC produced insulin only after several weeks, adult islets gave immediate insulin production. The search for an optimal immunosuppression was conducted in the pig-to-rat islet transplant model. A clear inhibitory effect on the xenograft rejection was observed when using some of the new drugs. The best results were achieved with a triple drug regimen consisting of cyclosporine, mycophenolate mofetil and leflunomide.     

Chain reactions linking acorns to gypsy moth outbreaks and Lyme disease risk

In eastern U.S. oak forests, defoliation by gypsy moths and the risk of Lyme disease are determined by interactions among acorns, white-footed mice, moths, deer, and ticks. Experimental removal of mice, which eat moth pupae, demonstrated that moth outbreaks are caused by reductions in mouse density that occur when there are no acorns. Experimental acorn addition increased mouse density. Acorn addition also increased densities of black-legged ticks, evidently by attracting deer, which are key tick hosts. Mice are primarily responsible for infecting ticks with the Lyme disease agent. The results have important implications for predicting and managing forest health and human health.     

An extended panel of hamster-human hybrids for chromosome 2q

A hamster-human hybrid containing only the q arm of chromosome 2 has been used to construct a panel of hybrids bearing reduced regions of chromosome 2 using the technique of irradiation fusion gene transfer. The human chromosome 2 carried the Ecogpt gene and all hybrids were selected using this marker. The integrated Ecogpt gene was localized to the region 2q33-34, resulting in the selective retention of this region in the hybrids. These data were combined with another previously constructed panel of hybrids containing regions of 2q, which were enriched for the region 2q36-37. The combined hybrid panel is useful for the mapping of new markers to defined regions of chromosome 2 and for the cloning of genes located on 2q by a positional strategy.     

Duodenoesophageal reflux induces esophageal adenocarcinoma without exogenous carcinogen

Central nervous system (CNS) disease is a major feature of simian immunodeficiency virus (SIV) infection of macaques. To define the spectrum of CNS lesions in SIV-infected macaques and the potential associations with viral strain and disease course, we performed a retrospective analysis of necropsies on 124 macaques with SIV-induced AIDS. Histologic evidence of CNS disease was observed in 71 (57.3%) of the 124 animals. SIV encephalitis was the most common CNS lesion occurring in 43.7% (31/71) of the animals with CNS disease and 25% of all animals. The incidence of SIVE correlated significantly with shortened survival (P=0.0207). In addition, SIVE was seen in 42.9% (15/35) of rapid progressors (animals that died within 200 days) compared to only 18% (16/89) of normal progressors (animals that lived longer than 200 days) (P=0.011). Animals with SIVE had higher viral loads in peripheral blood than those that did not, but this difference did not reach statistical significance. Similarly, while animals infected with uncloned SIVmac251 had a higher incidence of SIVE (27.5%; 14/51) than animals infected with molecularly cloned SIVmac239 and its T-cell tropic derivatives (18.5%; 10/54) this difference was not statistically significant. In this study rapid disease progression and SIVE were highly correlated making separation of viral determinants of virulence from those of neurovirulence difficult.     

Adrenergic and Cholinergic Nerves of the Human Urethra and Urinary Bladder. A histochemical study

The occurrence and distribution of adrenergic and acetylcholine esterase (AChE) positive nerves in the human urethra and urinary bladder were studied histochemically with the fluorescence method of Falck and Hillarp, and the copper thiocholine method of Koelle and Friedenwald. Both types of nerves were mainly confined to the layers of smooth muscle cells in the walls of the organs. In all parts of the urethra, there was a scanty supply of adrenergic nerves. Few adrenergic nerves were also found in the urinary bladder, except in the trigone area, where they were abundant. AChE-positive nerves were uniformly and richly distributed in the urinary bladder. Throughout the urethra the distribution of AChE-positive nerve fibres was uniform, but the number was clearly less than in the urinary bladder. No intrmurally located adrenergic or AChE-Positive ganglion cells could be demonstrated.     

MR imaging

MRI is a tool of unprecedented capabilities for evaluating arthritis and its progression. Not only can it non-invasively delineate the anatomy of all components of a joint with unparalleled clarity, MRI is also capable of probing important functional and compositional parameters of disease in these tissues. Particularly intriguing is MRI's potential for identifying very early changes of joint disease when clinical symptoms may be minimal or absent. Early detection of patients who are at risk for developing progressive disease may allow appropriate treatment to be initiated earlier, when there may be a greater chance of favourable outcome. MRI can, furthermore, provide objective and quantitative measures of disease progression and treatment response. Certain parameters, such as articular cartilage volume, have been validated cross-sectionally; however, their longitudinal performance has yet to be established. Further work is, therefore, necessary to thoroughly validate and optimize some of these measures so that they can begin to be used in more powerful ways to explore the pathophysiology and potential therapies of arthritic disorders.