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赣州皮肤医院激光去痘手术多少钱好医问答

2018年12月10日 16:27:34来源:放心在线

If you follow football, hockey, soccer, or boxing, then you know that athletes in these and other contact sports are at constant risk for a concussion. Every season several football players miss a number of games after absorbing vicious blows to the head.如果你喜欢橄榄球、橄榄球、足球或是拳击运动,那么你就会很清楚这些以及其他接触性运动中的运动员常处于脑震荡的危险境地。每个赛季都有数名橄榄球运动员由于头部遭受剧烈冲击而缺席接下来的一系列赛事。A concussion is a blow to the head that can result in temporary confusion, amnesia, nausea, dizziness, blurred vision, and loss of consciousness.脑震荡是头部受到撞击而导致的,可能造成暂时性思维混乱,失忆,呕吐,眩晕,视觉模糊以及失去意识。Although a single concussion does not appear to result in structural brain damage or swelling of the brain, repeated concussions can cause both.尽管一次脑震荡不会导致大脑结构性损伤或导致脑水肿,但是数次脑震荡可能引起上述两种情况同时出现。Concussions are caused in one of two ways: either by the head hitting a hard surface, or by the head spinning suddenly. Take, for example, a common incident during a football game. The quarterback is hit, falls backwards, and bangs his head on the turf.造成脑震荡的原因不外乎是这两种中的一种:头部撞到硬物,或者头部突然旋转。以橄榄球赛比较普遍的事件为例,四分卫触地得分,朝后方倒下,其头部就会猛烈撞击到草坪上。Although his skull stops suddenly upon impact, his brain, floating in cerebral fluid, keeps moving and hits the skull. Similarly, when a boxer gets hit in the head with a right hook, his head twists violently. The skull stops moving, but the brain keeps shaking for a few moments and may brush the skull.尽管他的头骨在受到冲击时瞬间会保持不动,但是他大脑内的脑脊液仍然在晃动并不断撞击头骨。同样的,当一名拳击手头部受到一记右勾拳时,他的脑袋瞬间剧烈扭转。头骨停止移动,但是脑浆却还会震动一会儿,并有可能擦到头骨。The result is a chemical imbalance in the brain. All the neurotransmitters in the damaged area fire simultaneously, causing an overload of chemicals that impair receptors involved in learning and memory. The flood of chemicals also constricts arteries, making it difficult for the damaged cells to get the nutrients they need to recover.结果是脑部化学失衡。所有受损区域的神经传递素同时作用,造成脑内化学物质超负荷运转,从而损坏学习与记忆的神经元。化学物质过多也会引起动脉收缩,导致大脑受损细胞难以吸收到利于复原的营养物质。Because the brain can take as long as several weeks to recover from a concussion, its a good idea to take a break from contact sports if youve had one.由于脑部需要长达数周的时间来恢复脑震荡带来的损伤,如果你脑部受到撞击最好还是休息一段时间再继续参加此类接触性运动。 /201306/243370。

  • Science and technology科学技术Medical technology医学技术Skin deep肌肤之下A better way to diagnose skin cancers诊断皮肤癌的更好方法DERMATOLOGISTS are good at spotting unusual bits of skin that might or might not be cancers.皮肤病医学家擅长发现一小块异常皮肤是否有患癌症的可能性。Testing whether they actually are, though, is quite literally a bloody pain.但是,要检查出是否真患癌症的确会让人感到出血之痛。For a piece of skin to be identified as malignant or benign it must be cut out and sent to a laboratory for examination under a microscope.因为要鉴定一块皮肤是恶性还是良性,就必须剪下来,然后送到实验室的显微镜下检验。But a team of researchers led by Rainer Leitgeb, a physicist at the Medical University of Vienna, hope to change that.但是,由维也纳医科大学物理学家Rainer Leitgeb带领的研究小组希望改变这个现状。As they describe in Biomedical Optics Express, Dr Leitgeb and his colleagues are exploring a technique called optical coherence tomography, which they think will allow skin cancer to be diagnosed in situ.正如他们在《生物医学快报》上所描述的那样,Leitgeb士和他的同事正在探寻光学相干断层成像术。在他们看来,使用这种技术能在原皮肤上进行皮肤癌诊断。OCT is a form of optical echolocation. It works by sending infra-red light into tissues and analysing what bounces back.OCT的原理是光学回声定位,先向身体组织发射红外线,The behaviour of the reflected rays yields information on the structures that they collided with.然后再分析反射回来的红外线。That, Dr Leitgeb hoped, could be used to generate a map of features just beneath the surface of the skin.Leitgeb士希望,这能用来绘制显示皮肤表面下特征的地图。Similar technology has been employed for nearly two decades by eye doctors and Dr Leitgeb felt that, with a bit of tinkering, it should work for skin as well.相似的技术应用于眼科已有将近二十年的历史。Leitgeb士认为,经过小小的改进,也能用于皮肤科。The OCT systems operated by ophthalmologists use low-power lasers which produce light with a wavelength of 850 nanometres.眼科医生操作的OCT系统使用的是低功率激光器,能够发出850纳米波长的光线,这刚好超出了眼睛视杆视锥层可感光的范围。That is just beyond the range detectable by the rods and cones of the eye, and is thus ideal for probing that organ without discomforting the patient.因此,既能够完成眼睛检查而又不给病人带来不适感,用这种激光再合适不过了。Skin, however, is insufficiently transparent at this wavelength, so one thing Dr Leitgeb had to do was change it.但是,皮肤在这种波长下还不够透明,因此Leitgeb士所要做的就是进行改变。Another thing which had to change was the speed at which the laser operates. In the ophthalmological system, images are built up from a series of pulses.除此之外,还需要改变激光器发射的速度。眼科用的是脉冲成像的方法。The more of these the laser sends in, the more light returns to the device and the higher the resolution of the resulting image.激光器发射进去的激光越多,反射出来的光线也就越多,所成像的分辨率也就越高。However, that image must be built up quickly, otherwise movement of the tissue being illuminated will blur it.但是,必须迅速建构图像,否则受到照射的组织就会运动,使图像变得模糊不清。For eyes, between 20,000 and 60,000 bursts a second is enough.用于眼镜检查的脉冲每秒2万至6万就足够了。But to photograph blood vessels inside skin Dr Leitgeb knew more would be needed. In the end, he commissioned a group of researchers at Ludwig-Maximilians University in Germany to design an instrument which produces light with a wavelength of 1,300 nanometres and has the ability to fire 440,000 pulses a second.士最终委托德国慕尼黑大学的一个研究小组设计了能够每秒产生1300纳米波长、44万脉冲的激光器。 With their new laser in hand, Dr Leitgeb and his colleagues set up an experiment that let them test the system on a range of skin conditions, including a healthy human palm, allergy-induced eczema on the forearm, inflammation of the forehead, and two previously diagnosed cases of basal-cell carcinoma.有了新的激光器,Leitgeb士和他的同事就开始进行实验,在不同状况的皮肤上测试人的器官系统,包括无任何疾病的手掌,前臂上过敏引起的湿疹皮肤,前额上有炎症的皮肤以及之前诊断过的两例基底细胞癌。They expected to see normal blood vessels in the healthy palm, increased perfusion caused by dilated and altered vessels in the eczema and the inflammation, and a chaotic jumble of vessels feeding the cancers.他们期待看到的结果是:无疾病手掌下的血管是正常的;前臂上的湿疹和有炎症的前额下的血管由于扩张和形变造成了灌注量的增加;而为癌细胞供血的血管乱七八糟扭成一团。And that is exactly what they did see.他们所看到的结果也正是如此。Moreover, the images of the vessels supplying blood to the tumours were good enough to allow them to calculate blood-flow rates.此外,供血给肿瘤的血管的图像十分清晰,他们还能计算出血流流速。That, Dr Leitgeb suggests, could also help treatment by allowing doctors to identify the times during their development when tumours are most vulnerable to starvation by having their blood supply cut off.士认为,这对治疗也有帮助:医生能通过该方式鉴定肿瘤发展中最易因切断血液供给而饿死的阶段。 /201401/274241。
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