2007年2月24日星期六

Junction

Junction v1.04

By Mark Russinovich
Published: November 1, 2006

Introduction
Windows 2000 and higher supports directory symbolic links, where a directory serves as a symbolic link to another directory on the computer. For example, if the directory D:\SYMLINK specified C:\WINNT\SYSTEM32 as its target, then an application accessing D:\SYMLINK\DRIVERS would in reality be accessing C:\WINNT\SYSTEM32\DRIVERS. Directory symbolic links are known as NTFS junctions in Windows. Unfortunately, Windows comes with no tools for creating junctions - you have to purchase the Win2K Resource Kit, which comes with the linkd program for creating junctions. I therefore decided to write my own junction-creating tool: Junction. Junction not only allows you to create NTFS junctions, it allows you to see if files or directories are actually reparse points. Reparse points are the mechanism on which NTFS junctions are based, and they are used by Windows' Remote Storage Service (RSS), as well as volume mount points.

Please read this Microsoft KB article for tips on using junctions.

Note that Windows does not support junctions to directories on remote shares.

If you want to view reparse information, the usage for Junction is the following:

Usage: junction [-s]

-s

Recurse subdirectories.

If you want to create or delete a junction, use Junction like this:

Usage: junction [-d] []

To delete a junction specify the -d switch and the junction name.

胆汁

胆汁的颜色:正常的胆汁应该是金黄色或墨绿色,清亮而无杂质。

  1. 草绿色:说明胆汁内的胆红素受到细菌作用或受到胃酸氧化。
  2. 白色:表示胆囊颈管或肝胆管内由于长期梗阻,胆汁中的胆色素及胆盐被吸收,由胆囊粘膜、胆管粘膜所分泌的白胆汁所代替,这种白胆汁都在手术后几小时内引流出来。
  3. 脓性:泥沙样混浊,说明胆道内炎症感染严重或泥沙样残余结石。
  4. 红色:胆道内有出血情况,主要由于胆管内发炎而引起小血管糜烂破裂而出血,一旦发生出血情况,可服消炎药,或少量多次输血,增加凝血因子;“T”形管内冲洗等。如仍出血不止,有可能要再次手术止血。思想上要有准备。

胆汁的性质、成份和作用

  胆汁是由肝细胞不断生成的具有苦味的有色液汁。成人每日分泌量约800~1000ml。胆汁的颜色由所含胆色素的种类和浓度决定,由肝脏直接分泌的肝胆汁呈金黄色或桔棕色,而在胆囊贮存过的胆囊胆汁则因浓缩使颜色变深。肝胆汁呈弱碱性(pH7.4),胆囊胆汁因碳酸氢盐被吸收而呈弱酸性(pH6.8)。

  胆汁除水份外,还有胆色素、胆盐、胆固醇、卵磷脂、脂肪酸、无机盐等成份。胆汁中没有消化酶,但胆汁对脂肪的消化和吸收具有重要作用。胆汁中的胆色素是血红蛋白的分解产物,主要为胆红素,其氧化物为胆绿素。胆汁中的胆盐为肝脏所分泌的胆汁酸与甘氨酸或牛磺酸结合的钠盐或钾盐。

  胆汁的作用主要是胆盐的作用。胆盐、胆固醇和卵磷脂等均可降低脂肪的表面张力,使脂肪乳化成许多微滴,从而增加胰脂肪酶的作用面积,有利于脂肪的消化;胆盐可与脂肪酸甘油酯等结合,形成水溶性复合物,促进脂肪消化产物的吸收。并能促进脂溶性维生素(维生素A、D、E、K)的吸收。

胆汁分泌和排出的调节

  肝细胞是不断的分泌胆汁,但在非消化期间,肝细胞所分泌的胆汁贮存于胆囊中。胆囊可以吸收胆汁中的水分、无机盐,使肝胆汁浓缩4~10倍,从而增加了贮存的效能。在消化期间,胆汁则直接由肝脏以及由胆囊大量排至十二指肠内,尤以食物进入小肠后的作用最明显。胆汁的分泌和排除也受神经和体液因素的调节。

  1.神经调节 和胰液分泌的神经调节类似,冲动沿迷走神经传出,通过末梢释放乙酰胆碱直接作用于肝细胞和胆囊,使胆汁分泌增加和胆囊收缩;通过G细胞释放胃泌素直接作用于肝细胞引起胆汁分泌增加。

  2.体液调节 多种体液因素参与调节胆汁的分泌和排除:①胃泌素可促进胆汁的分泌;②促胰液素对胆汁的分泌也有一定的促进作用,主要是使分泌量和HCO3-含量增加;③胆汁中的胆盐或胆汁酸排至小肠后,绝大部份能被小肠吸收入血至肝脏,促进胆汁分泌,当胆盐通过胆瘘流失至体外后,胆汁的分泌将比正常时减少数倍;④胆囊收缩素引起胆囊强烈收缩和肝胰壶腹括约肌舒张,使胆汁大量排出。

剖宫产后肠梗阻

今天病房来了个剖宫产后出现肠梗阻的病人,考虑其肠梗阻的原因可能为:假性结肠梗阻又称Ogilvie综合征、2年前有宫外孕手术史、患者术后使用镇痛泵。

剖宫产术后假性结肠梗阻4例报告(杨敏)

剖宫产术后假性结肠梗阻为少见的产科并发症。因其发生率低,且症状多被术后切口痛,宫缩痛所掩盖,易致误诊,贻误治疗时机,发生肠坏死,肠穿孔,全腹膜炎,中毒性休克,危及生命,故早期诊断和治疗至关重要。

发病原理及机理 假性结肠梗阻又称Ogilvie综合征,是1948年Ogilvie首先报道的。是由于支配结肠的交感神经阻断,副交感神经使结肠局限性痉挛性收缩引起肠梗阻,是结肠功能紊乱引起的非器质性肠梗阻。其中10%发生于产后,尤以剖宫产术后多见。可能与产后子宫体积突然缩小,腹压降低,血液重新分配以及生理性肠蠕动减弱,加上剖宫产术中盆腔操作对肠管机械性刺激有关。

诊断假性结肠梗阻临床表现酷似机械性结肠梗阻,痛、吐、胀、闭进行性加重,以进行性腹胀尤为突 ,一般无肠型及蠕动波。腹痛特点为持续性钝痛,少有阵发性绞痛,肠呜音减弱或消失。可有腹部压痛,但反跳痛和肌紧张不明显,易被产后宫缩痛所掩盖。有下腹部明显的腹膜刺激征,伴有发热,自细胞计数增高,则提示盲肠缺血、坏死、有穿孔的可能。直肠指诊是临床不可缺少的检查,X线检查是诊断的重要手段。腹部平片可见结肠扩张,如有气腹提示肓肠穿孔, 肓肠扩张直径在12cm以下不易发生穿孔,但如达14cm或以上时则穿孔危险增加。及时诊断和治疗可避免肠穿孔的发生。本组例1就是惨痛教训。

治疗一般采取保守疗法,包括禁食,禁水,静脉补液,胃肠减压,低压灌肠,应用抗生素预防感染,Lopez等 推荐3种处理方法:(1)应用上述方法保守治疗;(2)保守治疗无效且无急诊剖腹探查指征时可经结肠镜减压;(3)有腹膜刺激征和膈下游离气体时应急诊剖腹探查。小的穿孔可通过穿孔处行插管造瘘,较大者行肠切除或肠外置,二期吻合术。在临床工作中我们的体会是,剖宫产术前尽可能做到禁食,禁水,术中动作轻柔,减少手术创伤.尽量少对肠管干扰,无必要时一般不必将子宫托出腹壁,尽可能清理羊水,胎脂,血液,减少术后粘连。重视术后肠功能恢复情况,遇到术后腹胀明显,持续不排气者高度警惕本病,及早行x线平片检查,以早期诊断,早期治疗。治疗首选保守治疗,如 现腹膜刺激征,发热,白细胞计数升高,盲肠扩张>14cm应及时剖腹探查,必要时行盲肠造口术。

甲鱼的雌雄

今天在hjc看到抓甲鱼,回来搜了一下

通俗的讲,雄甲鱼后面的尾巴(就是生殖器)露出裙边的,很明显的;雌甲鱼则是很小的一根,几乎不露出裙边的。还有就是雄的可以长到很大个,雌的话不太长得大。雄甲鱼肚子特别白。一般人主要看尾巴啦。最好辨了

吃甲鱼一定要宰食活的,不能吃死的,因为甲鱼体内含较多的组胺酸,死后极易腐败变质,组胺酸可分解产生有毒的组胺物质,食后会引起中毒

The Climbing&Bouldering Grade System

The Yosemite Decimal System

Five classes of climbing difficulty
The Yosemite Decimal System consists of five general classes, the fifth being subdivided with a decimal notation, but it is generally accepted that some ratings are too high or too low because people want to brag or because the standards among climbers has changed over time, and many people have editorial comments about the YDS.

The class of a route is derived from its "crux" or hardest move. If you hike a class 2 trail from point A to point B, and are required to scale a 20 foot wall of rock (class 4) along the way, then you hiked a class 4 trail regardless of the normal exposure.

The argument that exposure has nothing to do with the class of the climb is not supported by the history of YDS. Exposure was implied in the definition of 4th and 5th class by the use of a rope. Starting in the 5th edition of Freedom, exposure was included in the class descriptions, probably because of the wide variety of techniques being used on the same climbs. In the 6th edition of Freedom, the wording has changed again.

Here are the five classes, where each bullet represents a different opinion as to what the class actually represents. When you are reading a route description or trip report, keep in mind that there may not be general agreement on ratings. The astonishing thing about the email discussion which prompted this expanded definition is that almost everyone thought that almost everyone ELSE agreed with them!

class 1 (used for some peaks that do NOT have trails)

hiking on trail
bikepath
walking, preferably uphill
walking along a clear, well established trail (sidewalk)

class 2

cross country, requiring route finding skills
cross-country, using hands for balance
hiking trail (goes with class 1 is a bike path)
difficult cross-country travel (thick brush, climbing over and around fallen trees, and big talus - hands are used for balance)
the trail is either non-existant or very uneven or intermittent and you may need to put your hand down once in a while for balance

class 3

scrambling on rocks using hands as well as feet
requires use of hands for climbing, rope may be used
I need my hands but might survive a fall
hands? Maybe. (goes with class 1 is a bike path)
rope is necessary only to provide comfort
MUST use your hands for progress but don't need to search for holds nor do you need Real Rock Climbing(TM) techniques

class 4

climbing on steep terrain requiring roped belay
I would die if I fell
hands? Yes! (goes with class 1 is a bike path)
exposed climbing such as a ladder going up the side of a water tank (belays should be used)
use a rope, but don't place protection
rope required to prevent serious injury if a fall occurs
why don't we just ditch Class 4 and call everything 5.0 that used to be Class 4!
you are leading along and it is not too hard and when you get to the end of the lead you notice that you haven't felt motivated to place any protection

class 5

climbing involving technical moves and protective hardware in case of a fall
safety rope (goes with class 1 is a bike path)
thin, exposed climbing, requiring skill (the holds are not obvious to a novice - this is where weird moves such as laybacks, underclings, and evangelical hammerlocks come into play_
leader places protection along the way
Real Rock Climbing(TM) where most people will use a rope (but where some very experienced people won't feel the need) and where serious injury or death is very likely if you take an unprotected fall

class 6 (not actually part of the YDS)

the rope bears the climber's weight on purpose
rope ladder (goes with class 1 is a bike path)
use equipment for aid

Hal Murray editorializes:
I'm an old fart. I started climbing when everybody still used pitons(metal spike with a hole through which a rope is threaded (used in mountain climbing) ). Back then, class 6 meant pitons were used for aid, class 5 meant pitons were used for protection, and class 4 meant you didn't need them but you still used a rope. But you could use trees or horns and still claim it was 4th class, so sometimes class 4 routes were pretty difficult - another branch of the game. Another description is that on a class 4 route, there is usually somebody in the group who is happy to lead everything without placing protection.
The "I would die if I fell" approach never made sense to me. I've done a lot of climbing that I call exposed 3rd where I surely would die if I fell off, but it was actually pretty easy because the holds were good and the rock was solid. Maybe I was just feeling good that day. Warm sun and a gentle breeze helps a lot.

Steve Eckert editorializes:
The problem is that class 4 and class 5 are not different except in the degree to which the route scares people. You use a rope for both, you set protection for both, and most people think you need a dynamic climbing rope for both. Class 4 is basically 5.0, and Class 5 goes all the way up to 5.13. In fact, the distinction between class 3 and class 4 is hard to draw uniformly because it's mostly based on whether people think they need a belay or not (which includes how loose or how exposed or just basically how scary it seems). This decision may change with experience, and formerly class 4 routes may become class 3!
Trying to lump everything (size of holds, looseness of rock, exposure) into a single axis is, IMHO(In My Humble Opinion if you ask me, my opinion is (Internet Slang) ),not optimal. The Yosemite Decimal system excels at differentiating how hard various technical climbs are, but it often fails to accurately describe mountaineering climbs. If you take away the handrail on an outside stairway, it is fatally exposed but still only class 1 in either system. As you narrow the width of the stairs, at some point a rope is required for safety but you still don't need your hands.

Andy W editorializes:
The rating system varies with each climbers perception of climbing, based on their own personal abilities. What one climber thinks as being "hands required", may be "done with a stroller and inline skates" by another. Attitude certainly affects rating. From what I understand, 5.10 used to be 6.0. That is, a route that could only be done as "aided", became "technical" as improvements in equipment and technique evolved.

James Schaffner editorializes:
I don't think the original question was concerned with the difference between 5.9 and 5.10, but rather the difference between hiking/scrambling/climbing classifications of all number grades. IMO, I believe it is quite subjective. As one can see from the discussions here, everyone seems to have an opinion. Even guide and instruction books can't seem to agree (even among different editions of the same book). The business about exposure(the state of being exposed to harm or risk) probably has little to do with the rating, as it appears we're talking difficulty, not risk of injury with a fall. As they say, you can drown as easily in 8 inches of water as in 8 feet, and you can kill yourself hitting your head on a rock if you fall down on a trail as easily as if you fall 1000 feet off a big wall. (Assuming you're as clumsy as I am and would actually fall down on a trail.)

Eric Beck quotes Joe Kelsey, author of the Wind River guidebook:
"I'm not sure I can explain the difference between class 2 and class 3, but I know which peaks my dogs have climbed." RJ Secor quips:
Class 1: you fall, you're stupid.
Class 2: you fall, you break your arm.
Class 3: you fall, you break your leg.
Class 4: you fall, you are almost dead (i.e., you can't breath and move your arms, legs, and head).
Class 5: you fall, you are dead.
Quoting Tom Patey: "A solo climber: a man who falls alone. A roped team: climbers who fall together."

Subdivisions of class five climbingIn Mountaineering, Freedom of the Hills, author Ed Peters explains the subdivisions of class 5:
"The experienced climber, having accomplished or attempted free climbs of varying degrees of difficulty in the YDS class 5 range, gains an understanding of the level of difficulty involved. To the beginner, however, these ratings are simply a set of numbers, understandably, easy if rated 5.0 and impossible if rated 5.13. To provide a slightly better understanding within the class for the beginner the following tongue-in-cheek description is provided:
5.0 to 5.4
There are two hand- and two footholds for every move; the holds become progressively smaller as the number increases.
5.5 to 5.6
The two hand- and two footholds are there, obvious to the experienced, but not necessarily so to the beginner.
5.7
The move is missing one hand- or foothold.
5.8
The move is missing two holds of the four, or missing only one but is very strenuous.
5.9
The move has only one reasonable hold which may be for either a foot or a hand.
5.10
No hand- or footholds. The choices are to pretend a hold is there, pray a lot, or go home.
5.11
After thorough inspection you conclude this move is obviously impossible; however, occasionally someone actually accomplishes it. Since there is nothing for a handhold, grab it with both hands.
5.12
The surface is as smooth as glass and vertical. No one has really ever made this move, although a few claim they have.
5.13
This is identical to 5.12 except it is located under overhanging rock."
Ratings are established on lead; the follower has a somewhat easier climb.

Don't believe every climbing rating


In Mountaineering, Freedom of the Hills, author Ed Peters warns against putting too much faith in published ratings:
It can sometimes be helpful to know who rated the climb; since ratings are give by humans and not by computers, human frailties can be interjected into the system. For example, some climbers will intentionally underrate climbs so that those who follow later will be impressed. Fortunately most climbers do attempt to give accurate ratings, and by the time a route is in a guide book, enough people have made the climb to show the rating as a concensus of opinion. Also remember that ratings are given for ideal conditions; unfavorable conditions can cause considerable change in a climb's difficulty.

如何选择登山鞋

登山鞋的分类

一般而言,走路用的登山鞋依用途分为:
mountaineering--极地攀登鞋:适用于冰雪岩混合的地形,必须有非常硬的鞋底且兼容于快扣式冰爪。但较不适用于平地健行。防滑、耐磨、透气快干/中高统、最重量、超硬底、通常防水、高保温、适用冰爪
trekking--长程重装健行鞋:山区长途健行,强调舒适耐用、远距离长时间使用,但不特别要求攀登功能。这种健行鞋鞋底中层较有弹性,使你踏出的每一步都能获得额外的推力;鞋底也同样的硬,让你能穿越崎岖困难的蛮荒地带。防滑、耐磨、透气快干;中统、重量、较硬底、通常防水、保温;3天以上、很多陡坡、砍路、找路、15公斤至30公斤、坏天气也走。
backpacking--短程重装健行鞋:专为大背包健行设计--行程不是很长,但背包很重,所以鞋底也是硬底,且支撑力很好。防滑、耐磨、透气快干/中统、轻量、硬底、通常防水
hiking--短程轻装健行鞋:轻装健行,因为背负重量不重,所以强调舒适性而舍弃硬鞋底。仍具有不错的支撑力。防滑、耐磨、透气快干/短统、最轻量、通常不防水、软底

买一双好鞋的10个技巧

  1、向高手请教,当你走进一家登山用品店买鞋时,要求最懂鞋的销售人员来协助,或是挑选一家有登山高手驻店的用品店,如果不在的话,就预约一个时间见面。
  2、一定要实际测量试穿,不要用之前买鞋的尺寸去推论,脚的尺寸是会变的。
  3、不要被尺寸的号码迷惑,不论是英国尺寸、欧陆尺寸或美国尺寸(还分男女),尺寸的大小会受制鞋工厂的标准与设计所影响,最好还是多试穿几个邻近的尺寸。
  4、晚上买鞋!夜晚时,人脚会略微膨胀,就像在山上走路时一样。
  5、要慢慢试,不要太心急做决定。准备两个半天来买一双好鞋,尽量多试试不同的厂牌与鞋款。
  6、带自己的袜子,最好是用来搭配登山鞋的袜子。
  7、绑好鞋带以后,活动脚指看能否碰到前壁,新鞋穿久后,可能会稍微增加宽度与厚度,但绝不会增加长度,太短的鞋子往往会撞击脚趾头与指甲。
  8、试穿时,穿著鞋走一走,一方面让新鞋的皮革或纤维较具弹性,一方面也可试出是否有不易察觉的不舒服处。
  9、买适合用途的鞋,但不要想一双鞋应付所有的用途。也不要只为一次特殊行程去添购一双功能特别的鞋子。
  10、抓住脚的感觉,挑一双最舒服的,用那双的标准去试所有的鞋子,只有一个人知道哪双鞋最适合你,就是自己。

  鞋子耐用/保养的技巧

  1、每次用完后清洁干净,稍微弄湿没关系,阴干它,决不要烘干鞋子。
  2、鞋干燥后,可加强其防泼水功能(鞋油、腊、喷剂)
  3、使用时绝对远离热源(炉子或火堆)、化学物品(除草剂、杀虫剂),他们会损坏鞋子的结构。

如何试鞋?

  1、穿著你预期会搭配这双鞋子的袜子,换句话说,先买袜子并且穿著袜子试,台湾登山环境下,袜子的搭配建议是一双薄的排汗袜加一双中等厚度的登山袜。
  2、购买中高统的鞋子时,先不要把鞋带全部系上,只要绑到脚踝上方即可,以免鞋带绑好后会影响你的判断。在这里,先感觉前后左右有没有顶到鞋内任何一方,需注意,登山鞋常穿后长度不会改变,但内部宽度与高度会稍微增加,所以,试鞋时,前后长度一定要够,够的标准是略松,而左右宽度则可以略紧或刚好。
  3、前后左右没问题之后,将鞋带全部绑上,记得要绑的够紧,其它的部分请参考买一双好鞋的10个技巧。

我买鞋的经验:首先穿上厚袜子(如果没有就把两只都穿一只脚上),穿上鞋,穿上鞋带。
1、在不系鞋带的情况下,把脚往后跟靠,感觉鞋底对脚的支撑情况,尤其是脚窝处是否有合理的弧线
2、鞋左右两边是否大小合适,不能有太大的空隙,脚尖前面应有较大的空隙
3、把脚向鞋尖方向靠,脚根和鞋跟应该有一指半到两指的空隙(鞋带全松开);
4、系紧鞋带,脚根、脚踝、脚掌等各部位都应该得到合理的支撑,任何地方不能有太空或太紧的感觉,站上有15度斜角的平台,以测试脚尖和脚底是否舒适
5、在硬地上使劲磕脚尖(别让店老板看见,会心疼的),脚尖都应该不会顶到鞋尖,如果到了,就说明鞋还太小;
6、接下来的选择是为了尽可能减短合脚的磨合期。系紧鞋带后,后跟不要太紧、高帮的鞋子脚踝不要太紧、鞋舌不要太压脚面。其实只要选到合适的尺码、鞋足够好,是有可能不需要磨合期的(不过我还没找到)。

Multi-pitch climbing

Multi-Pitch Climbing is the ascent of climbing routes with one or more stops at a belay station. Each section of actual climbing between stops at the belay stations are called a pitch. The leader ascends the pitch, placing gear and stopping to anchor themselves to the belay station.

The reason for the stops can be determined by choice, convention or necessity. For example:

  • The rope is too short to do the entire route in one pitch (necessity).
  • The leader has run out of protective gear (necessity).
  • Previous climbers have placed protective bolts at the location for a belay station (convention).
  • The leader chooses to rest or exchange leads before the next section of the climb (choice).

The general purpose of these stops is to allow the second to ascend to the point of the lead climber while collecting the protective gear from the route in the course of the lead climber's ascent. At the belay station, the protective gear is collected, possibly exchanged to a new leader, and the leader of the next pitch ascends the route.

2007年2月5日星期一

下肢静脉曲张

  下肢静脉曲张系指下肢浅静脉系统处于伸长、蜿蜒而曲张状态,多发生于持久从事站立工作或体力劳动的人。

  临床表现:单纯性下肢静脉曲张所引起的临床表现,一般并不严重,主要表现为下肢浅静脉蜿蜒扩张迂曲,如病程继续进展,要到后期,尤其是当交通静脉瓣膜破坏后,可出现轻度肿胀和足靴区皮肤营养性变化,包括皮肤萎缩、脱屑、瘙痒、色素沉着、皮肤和皮下组织硬结、甚至湿疹和溃疡形成。

  治疗:单纯性下肢静脉曲张的治疗,可分三类:
  1. 非手术疗法 主要包括患肢穿弹力袜或用弹力绷带,使曲张静脉处于萎瘪状态,弹力袜的压力应远侧高而近侧低,以便血回流;此外,还应适当卧床休息、抬高患肢,避免站立过久等。非手术疗法仅能使病变暂停进展,适用于下列情况:①病变局限、程度较轻而无症状者;②妊娠妇女,鉴于分娩后症状往往自行消失,可暂行非手术疗法;③估计手术耐受力极差者。
  2. 硬化剂注射和压迫疗法 适用于单纯型病变,亦可作为手术的辅助疗法,以处理剥脱不尽的曲张静脉。常用的硬化剂如5%鱼肝油酸钠、酚甘油液(2%酚溶于25%~30%甘油液中)等。注射时,病人取平卧位,选用细针,针头进入静脉后,在穿刺点上、下,各用手指向近远侧压迫,使受注射静脉段处于空虚状态。一处注射硬化剂0.5ml,维持手指压迫一分钟,局部换用卷起的纱布垫压迫,自足踝至注射处近侧穿弹力袜或敷用弹力绷带后,立即开始主动活动。维持压迫的时间,大腿部1星期,小腿部6星期左右。
  3. 手术疗法这是处理下肢静脉曲张的根本办法。凡是有症状者,只要没有禁忌证,如手术耐受力极差等,都应手术治疗。手术方法基本上分三种:①高位结扎大隐或小隐静脉;②剥脱曲张的大隐或小隐静脉;③结扎功能不全的交通静脉。对剥脱不尽而残留的曲张静脉,可辅用硬化剂注射和压迫疗法。 具体见《外科手术学》P632。

静脉石(phlebolith):干缩的静脉血栓发生钙盐沉积而形成的坚硬质块。一般是见于静脉曲张、深静脉血栓的患者,是静脉曲张发展到一定时间的产物。
A phlebolith is a venous calculus. It arises from the calcification of a venous thrombus and may be seen as a local complication of deep venous thrombosis.It is most commonly found in pelvic veins.

2007年2月3日星期六

王忠诚院士讲课幻灯

转载 from 王忠诚院士讲课幻灯


为什么喝酒有的人会脸红,有的人会脸发白?

  让我们从脸红的原因说起吧。很多人以为是酒精导致的,其实不然,是乙醛引起的。乙醛具有让毛细血管扩张的功能,而脸部毛细血管的扩张才是脸红的原因。所以喝酒脸红的人意味着能迅速将乙醇转化成乙醛,也就是说有他们有高效的乙醇脱氢酶 (alcohol dehydrogenase)。 不过我们不能忘了还有一种酶,乙醛脱氢酶(aldehyde dehydrogenase)。喝酒脸红的人是只有前一个酶没有后一个酶,所以体内迅速累积乙醛而迟迟不能代谢,因此会长时间涨红了脸。不过大家都有经验,当1-2个小时后红色就会渐渐腿去,这是靠肝脏里的P450慢慢将乙醛转化成乙酸,然后进入TCA循环而被代谢。
  那么喝酒比较厉害的人是怎么回事呢?这些人往往越喝脸越白,到一个点突然不行了,烂醉如泥。那是因为这样的人高活性的乙醇脱氢酶和乙醛脱氢酶均没有,主要靠肝脏里的P450慢慢氧化(因为P450是特异性比较低的一群氧化酶)。那么,这样的人为什么会给人很能喝酒的感觉呢?那时因为他们靠体液来稀释酒精,个头越大感觉越能喝酒。在正常情况下,酒精浓度要超过0.1%他们才会昏迷,对大多数南方人来说是半斤白酒,而北方人由于体型大,可以喝到8两到一斤白酒。但不管什么人,如果他是脸越喝越白型的,最好不要超过半斤,不然有急性酒精中毒的可能性。
  如果一个人即有高活性的乙醇脱氢酶又有高活性的乙醛脱氢酶会怎样呢?他/她就是传说中的酒篓子。如何判断他/她是不是酒篓子呢?看是不是大量出汗。因为如果两个酶都高活性,酒精迅速变成乙酸进入TCA循环而发热,所以大量发热而出汗。碰到这样的人你只能自认倒霉,就是十个八个正常人也斗不过他。好在这样的人不多,大概10万分之一左右吧。   有一点要提醒大家,喝酒脸红的人其实不容易伤肝脏,而和酒脸白的人特别容易伤肝脏。红脸的人大家一般少劝酒,因此喝得少,酒后发困,睡上15-30分钟就又精神抖擞了。而白脸的则往往不知自己的地线,在高度兴奋中饮酒过量,直到烂醉。他们体内的酒精由于没有高活性的酶处理而发生积累,导致肝脏损伤。酒精性肝损伤一般只发生在这些人身上。红脸的人可以连续几餐即便喝吐了也喝酒,而白脸的人需要更多时间的休息,因为酒精的代谢需要一两天的时间。   顺便提一下,根据有关研究江浙两省的人(古代吴国和越国的后代,正好我是越国后代,难怪我们那边有很多都会脸红,至少我碰到过很多跟我类似的)似乎是红脸基因的起源地,也就是说这些人多数带有高活性的乙醇脱氢酶。而北方人多数是白脸型的。那么如果你是北方出生的,又是红脸型的,说明什么呢?答案是明显的,因为红脸基因是显性基因。
  喝酒的同时要多喝白开水(也是酒里掺水的一种,呵呵),千万不要喝茶水.