如何为黑白照片上色

<正>想要让老旧的黑白照片重新焕发光彩吗?Ben Brain将教大家一套比较简单的方法为扫描的黑白旧照片手工上色。如果你手上有一些黑白的旧照片或者单色的数码文件需要为其上色,那么这篇教程正适合你。我们将会告诉你如何在数码     

打造现代感十足的人像摄影作品

<正>Ben Brain向大家展示如何使用黑白等调整图层将一幅普通的人像照片变得现代感十足。和很多创意产业一样,摄影行业也有属于自己的潮流。只需要看看Flickr或者印刷精美的杂志,我们就能发现流行趋势。有     

拍出《Top Gear》风格的汽车大片

想拍出全球最畅销的汽车杂志《Top Gear》风格的精彩大片么?想要留下汽车的艺术性微距影像吗? Ed Godden向你展示如何拍出更好的汽车摄影作品。     

Vascularized bone flaps versus nonvascularized bone grafts for mandibular reconstruction: an outcome analysis of primary bony union and endosseous implant success

We present a patient with a lesion of the mesial frontal cortex, including the supplementary motor areas bilaterally, who on clinical examination revealed no spontaneous movements, although neurophysiological examination indicated integrity of the corticospinal tract to thenar and tibialis anterior muscles bilaterally. The patient was alert, speech was hesitant, and he was able to move his hands only on command. The role of the supplementary motor areas in planning, setting, and execution of skillful voluntary movements has been previously established by direct cortical electrical stimulation and studies of regional cerebral blood flow. The findings in our patient support the role of the supplementary motor areas in initiating movements. The presence of motor evoked potentials after acute insults to the brain is considered to be associated with a good functional outcome. This is in contrast to our patient who did not show improvement in motor performance, despite preserved motor evoked potentials. Hence, in the case of bilateral lesions to the supplementary motor areas sparing the corticospinal tract, the presence of motor evoked potentials may not predict functional recovery.     

Effects of neurotrophins on embryonic retinal outgrowth

In the literature it is generally assumed that venous reflux within the radicular veins is prevented by the presence of bicuspid valves and narrowing of the transdural part of these vessels. Recently, we performed a human cadaver study of the internal vertebral venous plexus. Surprisingly, a large number of radicular and perimedullary veins appeared to be filled with Araldite CY 221 mixture, after injection of this material into the vertebral venous system, implicating reflux via the radicular veins and suggesting insufficiency of the presumed anti-reflux mechanism. Therefore, it was decided to study the radicular veins in order to determine and to investigate the presence or absence of anti-reflux mechanisms within this system. The vertebral venous systems of ten fresh human cadavers, between 64 and 93 years of age, were injected with Araldite CY 221 mixture. After polymerization, all cadavers were dissected and the spinal nerve sheaths, including nerve roots, radicular veins and epidural veins, were excised as a whole. After macroscopical examination, serial sections (40 microm) were cut on a freezing microtome and stained in Von Gieson medium. Every third section was stained immunohistochemically with smooth muscle antigen (SMA), to visualize smooth muscle cells. In all cadavers, a number of intradural radicular veins was filled with Araldite. Employing microscopical examination, no bicuspid valves were found. However, four structures were encountered that might serve as ananti-reflux-mechanism: 1) intravenous dural folds, 2) meandrous configuration, and 3) narrowing of the radicular veins at the point of penetration of the dura mater, and 4) varying numbers of smooth muscle fibers in the walls of the intradural and extradural parts of the radicular veins. Reflux via the radicular veins seems to be a physiological phenomenon. Structural valves have not been encountered during this study. Intravenous dural folds, meandrous configuration and narrowing of the transdural part of the radicular veins, and the presence of large numbers of smooth muscle cells in the radicular venous walls suggest the existence of a dynamic reflux-regulating system that has the ability to increase the intravascular resistance under conditions of venous hyperpression, in order to protect the spinal cord from venous pressure waves. Possibly, venous reflux via the radicular veins has a role in selective cooling of the spinal cord.     

Modelling the strengthening of glass using epoxy based coatings

Glass strength can be increased by applying epoxy based surface coatings. A number of models have been presented in the literature to explain the strengthening afforded by these coatings but until now there has been no clear evidence to definitively support one model over another. In this work, finite element models (FEM) of four-point bending test specimens have been developed. These models have been used to study the strength of cracked uncoated and surface coated specimens in order to identify the strengthening mechanism. The FEM results showed that full filling of the crack using epoxy coating is sufficient to heal the crack if the coating inside the crack is ideally glued to the crack surfaces. It is also shown that under these circumstances the coating modulus is relatively unimportant parameter. FEA results for partially filled cracks show that increasing the filled percentage increases the strengthening. Fractographic analysis of the 10 kg indented and coated samples showed that the fracture surfaces do not follow the median crack symmetric plane and that fracture started from another plane when coated properly, however the fracture surface of these samples still starts from the indentation site. On the other hand, fractographic analysis of the 1 kg indented and properly coated samples showed that the samples failed from their edges which indicate that the crack was overcome. The finite element results show that the diamond imprint resulting from the Vickers indentation play an important role in this type of fracture.     

Bolus dispersal through the lungs in surfactant replacement therapy

A model is presented of surfactant replacement therapy. An instilled bolus is pushed into the lungs on the first inspiration, coating the airways with a layer of surfactant and depositing some in the alveoli. Layer thickness depends on the capillary number (muU/gamma, where mu, U, and gamma are bolus viscosity, advancing meniscus velocity, and surface tension, respectively). Larger capillary number leads to thicker layers, reducing alveolar delivery. Subsequently, surface tension gradients sweep surfactant into alveoli not receiving surfactant during the first inspiration. The effects on spreading of sorption kinetics, bolus viscosity, initial layer thickness, initial penetration of surfactant, gravity, and shear stress are examined. Sorption nearly eliminates surface tension gradients in central airways but produces a sharp transition at the leading edge of the exogenous layer. Local thinning of the liquid layer results, trapping 95% of the surfactant in the airways. Gravity and ventilation augment transport somewhat. Transport to the periphery takes 4-170 s for the leading edge but considerably longer for the bulk of the surfactant. The model demonstrates how the various physical parameters governing surfactant distribution might alter the response to surfactant replacement therapy.