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Anal Dilatation for Anal Fissure

Long-Term Outcomes after Anal Dilatation for Anal Fissure

Richard Babor 1,John P .Keating 1,William H.Isbister 2

Abstract

Background:Recurrence and anal incontinence are recognized as troublesome com-plications following the treatment of fissure in ano by anal dilatation.Most previous studies of anal dilatation have evaluated outcomes,only,over the short term.

Patients and Methods:Attempts were made to contact 104 patients who had been treated by anal dilatation for fissure in ano during the period 1975—1990.Each pa-tient contacted was sent a postal questionnaire.Each patient was assigned an inconti-nence score based on the information returned and this score was compared with the scores of five age and sex matched controls.Patients requesting reevaluation of their incontinence in their questionnaires were further examined by endoanal ultrasound and anorectal manometry.

Results:45 patients responded,14 had died,and 45 were lost to follow up.The median follow-up interval was 15.5 years.The total self reported recurrence rate was 24%.Pa-tient’s incontinence scores were low and did not differ significantly from matched pop-ulation controls.

Conclusions:Fissure in ano treated by anal dilatation has a significant recurrence rate.The incidence and severity of anal incontinence in those treated by anal dilatation is no different to that of the general population.Other treatment modalities should be evaluated over the longer term before anal dilatation is discarded as a treatment op-tion for fissure in ano.

Key Words:Anal dilatation .Anal fissure .Anal continence

Langzeitergebnisse der Analdilatation bei der Behandlung von Analfissuren

Zusammenfassung

Hintergrund:Rezidive und anale Inkontinenz sind als belastende Komplikationen nach einer Behandlung von Analfissuren mittels Analdilatation bekannt.Die neuesten Un-tersuchungen bewerteten jedoch nur die Kurzzeitergebnisse.

coloproctology

coloproctology 2003;25:135–41DOI 10.1007/s00053-003-5094-4

Original Article

University Department of Surgery,Wellington School of Medicine,Wellington,New Zealand,2

Hangstra?e 4,D-90537 Moosbach-Feucht.

Received:March 15,2003;accepted:April 22,2003

Introduction

The aim of this study was to document the recurrence rate and incontinence scores of patients with fissure in ano who were treated by anal dilatation a minimum pe-riod of 10 years ago.Anal dilatation is a procedure which is still in widespread use for the treatment of fissure-in-ano [3] and concern has been expressed by several au-thors regarding problems of incontinence experienced by patients after the procedure [19,23].Some degree of incontinence has been reported in between 0–49% of patients treated in this way [2,4,6–8,10,12–16,20,24, 26,30–32].Few studies have attempted,however,to fol-low patients beyond 5 years [2,12,26,30] and only one series has reported the severity of incontinence objec-tively using a recognized incontinence grading scale [26].

In 1995 Isbister & Prasad [7] reported their 15-year experience treating fissure in ano by anal dilatation. Over the period of study,between 1975 and 1990,104 pa-tients were treated and evaluated clinically after a 4-week follow-up interval.The present study attempted to reevaluate this same group of patients over a much longer term,with particular respect to recurrence and incontinence.In addition the study aimed to quantify the incontinence and control for the background prevalence of the problem in the local community.

Patients and Methods

An attempt was made to obtain contact information for all of the previously studied patients from Wellington Public Hospital records,the National Health Index and local telephone directories.All patients for whom con-tact information was found were sent a questionnaire by post.Patients who did not respond within 2 weeks of re-ceiving the questionnaire were telephoned in an attempt to increase the response rate.

The questionnaire examined patient’s satisfaction with initial treatment,recurrence of a fistula in ano and it’s treatment,the diagnoses of other chronic or major colorectal or anal conditions,and the patient’s current

Patienten und Methoden:Es wurde versucht,104 Analfissurpatienten zu kontaktieren, die von 1975 bis 1990 mittels Analdilatation behandelt worden waren.Jeder dieser Pa-tienten erhielt per Post einen Fragebogen zugesandt.Dann wurde jeder Patient einem Inkontinenzscore zugewiesen,der auf den zurückgesandten Informationen basierte. Dieser Score wurde dann mit den Scores von fünf alters- und geschlechtsgleichen Kon-trollprobanden verglichen.Patienten,deren Inkontinenzbild im Fragebogen eine erneute Bewertung erforderte,wurden mittels endoanalem Ultraschall und anorek-taler Manometrie weiter untersucht.

Ergebnisse:Insgesamt beantworteten 45 Patienten den Fragebogen,14 Patienten waren zwischenzeitlich verstorben,die restlichen 45 Patienten konnten nicht erreicht werden und standen für die Nachuntersuchung nicht mehr zur Verfügung.Der durch-schnittliche Nachuntersuchungszeitraum betrug 15,5 Jahre.Die gesamte,von den Pa-tienten berichtete Rezidivrate lag bei 24%.Der von den Patienten angegebene Inkon-tinenzscore war niedrig und unterschied sich nicht signifikant von dem der Kontroll-gruppe.

Schlussfolgerungen:Analfissuren,die mittels Analdilatation behandelt wurden,sind mit einer signifikanten Rezidivrate belastet.Inzidenz und Schweregrad der Inkonti-nenz der mittels Analdilatation behandelten Fissurpatienten unterscheiden sich je-doch nicht von der Allgemeinbev?lkerung.Andere Behandlungsm?glichkeiten soll-ten im Hinblick auf die Langzeitergebnisse bewertet werden,bevor die Analdilatation als Behandlungsoption für Analfissuren v?llig negiert wird.

Schlüsselw?rter:Analdilatation .Analfissur .Analinkontinenz

The Wellington Ethics Committee granted ethical approval for the study.

Results

14 patients had died during the follow-up interval and contact information was obtained for 47 patients.45 of the 47 patients who could be located returned completed questionnaires so that,overall,long term follow-up in-formation was available for 50% (45/90) of the survivors of the original group of treated patients.Three female patients were excluded from analysis of IS because they had had major colorectal surgery that affected their con-tinence during the follow up interval.One had a pan-proctocolectomy for Beh?et’s colitis,a second had a pan-proctocolectomy with a J-pouch for ulcerative colitis and a third had a subtotal colectomy for Crohn’s disease.Of the remaining 42 patients,three had diagnoses of in-flammatory bowel disease but these patients were not excluded from the analysis.

The median follow-up interval was 15.5 years.The patients who responded and were included (42/104) and the patients who were not able to be contacted (45/104)were similar with respect to age,sex,and length of fol-low-up interval.The sex distribution and length of fol-low-up of the respondents was similar to the entire group of 104 patients (Table 2).

37 patients were satisfied with their initial treatment,ten patients developed a further fissure in ano,and six of these needed further treatment.Three had a second anal dilatation and three were treated non-operatively.

symptoms.The frequency,severity and effect on lifestyle of anal incontinence were combined in an incontinence score (IS) (Table 1) [9].Completed questionnaires were analyzed together with the patient’s hospital records.All of the patients studied had been treated previ-ously using a standard technique in which,under general anaesthesia,a four finger anal dilatation was maintained for 4 minutes.A gauze roll was then inserted into the anal canal to minimize postoperative submucosal bleed-ing and removed either when the patient complained of anal pain or 4 hours after surgery [6].

Each patient included in the study was assigned five matched controls who were derived from the general population.These controls were matched for age and sex and were derived from a group of 717 subjects who were part of a contemporaneous study to identify the com-munity incidence of anal incontinence.They were ran-domly selected from the electoral role [11].Patients and controls were asked to complete identical questionnaires concerning anal incontinence.The IS of the patients and the mean IS of each set of five controls were compared using the Wilcoxon rank sum test.

Patients who requested a specialist referral for anal incontinence on their completed questionnaires were in-vited to attend a colorectal clinic for further evaluation.Each of these patients was examined by endoanal ultra-sound (Bruel & Kjaer,Naerum,Denmark,Medical Real-time USS T1849 with 10 MHz 90°rectal transducer T8531) and anorectal manometry (four channel balloon tipped anorectal manometer,“Polygraf for Windows”,Synectics Medical,TX,USA).

Table 2.Disposition of original patients.Tabelle 2.Teilnehmer der Fragebogenaktion.

32 patients had an IS of three or less (Figure 1).Six patients recorded an incontinence score of six or greater and all of these patients were male.

One of these patients had been dilated a second time within 12 months of the original dilatation and 12 years later had been treated for recurrent perianal abscess with incision and drainage and laying open of a fistula in ano on two occasions.He was also diagnosed with Ir-ritable Bowel Syndrome.He attributed his “mild”in-continence to perianal scarring secondary to this recur-rent sepsis (IS 7).Another patient was dilated twice within 12 months of his original surgery but had no fur-ther anal surgery and complained only of “mild”incon-tinence that did not require the use of a pad but affected his everyday activities “sometimes”(IS 7).The other four (IS 6,8–10) were dilated once only and had no fur-ther anal surgery or colorectal morbidity.One of these four patients was treated nonoperatively for recurrence.The incontinence scores of patients were not signifi-cantly different to those of the matched controls (Table 3).Five patients requested further evaluation (Figure 1) and four attended the colorectal clinic (Table 4).

Two patients with sphincter defects were identified.One,a 47-year-old male (IS 1),had symptoms of in-continence which were mainly attributable to urgency and diarrhea and subsequent colonoscopy and biop-sies proved nondiagnostic.He awaits further investi-gation.The other,a 70-year-old female (IS 4),com-plained of incontinence to flatus only.She had a his-tory of three vaginal deliveries,two of which were as-sisted by forceps.

Discussion

This small study suggests that,10 years or more follow-ing anal dilatation for fissure in ano,anal continence in treated patients does not differ significantly from conti-

Figure 1.Distrubtion of incontinence scores (IS).Abbildung 1.Aufteilung der Inkontinenzscores (IS).

Table 3.Incontinence scores (IS).Tabelle 3.Inkontinenzscores (IS).

nence in the population at large.The inability to contact about half of the original patients,however,consequent upon the long follow-up interval,was a potential source of bias.There did not appear to be any significant dif-ferences in age,sex,and length of follow-up between re-sponders and those patients who could not be contacted so it might be assumed that the responding patients were reasonably representative of the whole group.In addi-tion,patients with chronic anal,colorectal or medical co-morbidities had ongoing contact with the public hospi-tal system and thus would have been more likely to be captured in the survey,and probably more inclined to re-spond to the questionnaire.These patients would have tended to skew the outcomes towards a poorer result.

Despite the methodological and statistical limita-tions of this study it represents a long-term audit of al-most half the anal fissure workload over a 15-year pe-riod for a single University Colorectal Service.Within this cohort it was not possible to identify a single patient who had significant incontinence that was directly at-tributable to a sphincter defect caused by anal dilatation and no patient had a persistent fissure at follow-up. These results,however,may simply reflect the natural history of the condition rather than the efficacy of the treatment.

The rates of patient satisfaction and recurrence of fissure in ano,in the present study,were broadly similar to those reported in other studies looking at the treat-ment of anal fissure by anal dilatation [2,4,6–8,10, 12–16,20,24,26,30–32].The anal incontinence rate in the control group,however,of a severity that affected lifestyle (8.1%) [11],was considerably higher than that found in two other large surveys in other general popu-lations (2.2% and 4.3%) [17,27].These population sur-veys stratified the severity of incontinence relatively crudely whereas the incontinence grading scale used in the current study was probably more sensitive to minor degrees of incontinence and may explain the present findings.In future studies it may be more useful to quan-tify changes in continence and only one study has at-tempted to do this previously [2].

In a recent report [26],in which 241 patients treated by anal dilatation were followed up for a median of 7.8 years and their incontinence objectively quantified us-ing the Browning & Parks classification [1],nine (3.8%), who were continent prior to anal dilatation,were found to have grade B incontinence or worse following dilata-tion.Eleven (28%) of the patients from the present study would have had grade B incontinence or worse had the patients been reclassified according to this scale. The patients in the current study,however,were not ex-cluded from analysis because their continence was im-paired prior to anal dilatation.This could explain the higher rate calculated in the present study.

Little data is available regarding the long-term ef-fects of other methods for the surgical treatment of fis-sure in ano.One study of lateral sphincterotomy,after a mean follow-up of 4.3 years,reported an incidence of persistent minor defects in anal continence of 15% [29]. Another found that 18% of patients had new ongoing minor impairment of anorectal control after a mean fol-low-up of 41 months [28].A recent meta-analysis of com-parative trials of the surgical management of fissure in ano looked specifically at the end points of “persistence

Table 4.Results of further clinical examination in four patients requesting reevaluation.IS = incontinence score;N = normal;L = low; ND = not done;RAIR = recto-anal inhibitory reflex.

Tabelle 4.Ergebnisse weiterer klinischer Untersuchungen von vier Patienten,die um eine Auswertung baten.

n n

of fissure”and “incontinence to flatus”[18].In this analysis,it was found that most trials were significantly underpowered and information regarding the duration of follow-up in the included trials was conspicuously ab-sent.It was concluded,however,that lateral sphinctero-tomy (open or closed) was superior to anal dilatation with respect to both of the defined end points but this conclusion might have been different had follow-up been documented and similar in both groups.As with the studies of anal dilatation,no trials of lateral sphinc-terotomy have attempted truly long-term follow-up.A recent review of treatment modalities for fissure in ano speculates that,given the multifactorial etiology of anal incontinence and the tendency for etiological factors to accumulate over time,a follow-up period of less than 20 years is likely to underestimate the effect of sphinctero-tomy on incontinence [22].This probably also applies to anal dilatation.

Anal dilatation is a simple and comparatively effi-cacious treatment for anal fissure.Most patients are sat-isfied by their treatment despite a significant rate of re-currence and long-term follow-up does not demonstrate a significant difference in continence between patients and the general population.Anal dilatation is still one of the recommended methods of treating patients with chronic fissure in ano according to the American Soci-ety of Colon and Rectal Surgeon’s practice parameters [21].Alternative treatment modalities should be evalu-ated over the longer term before anal dilatation can be discarded as a treatment option for fissure in ano re-fractory to nonoperative management.

Acknowledgments

Kaye Reardon,Supervisor,Medical Records Department, Wellington Hospital,Wellington,New Zealand.Gordon Purdie, Biostatistician,Wellington School of Medicine,Wellington,New Zealand.

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Address for Correspondence

John P.Keating

Senior Lecturer in Surgery

Wellington School of Medicine

P.O.Box 7345

Wellington South

New Zealand

e-mail:surgjk@https://www.wendangku.net/doc/b48169301.html,

to与for的用法和区别

to与for的用法和区别一般情况下, to后面常接对象; for后面表示原因与目的为多。 Thank you for helping me. Thanks to all of you. to sb.表示对某人有直接影响比如，食物对某人好或者不好就用to; for表示从意义、价值等间接角度来说，例如对某人而言是重要的，就用for. for和to这两个介词，意义丰富，用法复杂。这里仅就它们主要用法进行比较。 1. 表示各种“目的” 1. What do you study English for? 你为什么要学英语？ 2. She went to france for holiday. 她到法国度假去了。 3. These books are written for pupils. 这些书是为学生些的。 4. hope for the best, prepare for the worst. 作最好的打算，作最坏的准备。 2．对于 1．She has a liking for painting. 她爱好绘画。 2．She had a natural gift for teaching. 她对教学有天赋/ 3．表示赞成同情，用for不用to. 1. Are you for the idea or against it? 你是支持还是反对这个想法？ 2. He expresses sympathy for the common people.. 他表现了对普通老百姓的同情。 3. I felt deeply sorry for my friend who was very ill. 4 for表示因为，由于（常有较活译法） 1 Thank you for coming. 谢谢你来。 2. France is famous for its wines. 法国因酒而出名。 5．当事人对某事的主观看法，对于（某人），对…来说（多和形容词连用）用介词to，不用for.. He said that money was not important to him. 他说钱对他并不重要。 To her it was rather unusual. 对她来说这是相当不寻常的。 They are cruel to animals. 他们对动物很残忍。 6．for和fit, good, bad, useful, suitable 等形容词连用，表示适宜，适合。 Some training will make them fit for the job. 经过一段训练，他们会胜任这项工作的。 Exercises are good for health. 锻炼有益于健康。 Smoking and drinking are bad for health. 抽烟喝酒对健康有害。 You are not suited for the kind of work you are doing. 7. for表示不定式逻辑上的主语，可以用在主语、表语、状语、定语中。 1．It would be best for you to write to him. 2．The simple thing is for him to resign at once. 3．There was nowhere else for me to go. 4．He opened a door and stood aside for her to pass.

of与for的用法以及区别

of与for的用法以及区别 for 表原因、目的 of 表从属关系介词of的用法（1）所有关系 this is a picture of a classroom （2）部分关系 a piece of paper a cup of tea a glass of water a bottle of milk what kind of football，American of soccer？（3）描写关系 a man of thirty 三十岁的人 a man of shanghai 上海人（4）承受动作 the exploitation of man by man．人对人的剥削。（5）同位关系 It was a cold spring morning in the city of London in England．（6）关于，对于 What do you think of Chinese food？你觉得中国食品怎么样？介词 for 的用法小结 1. 表示“当作、作为”。如: I like some bread and milk for breakfast. 我喜欢把面包和牛奶作为早餐。What will we have for supper? 我们晚餐吃什么?

2. 表示理由或原因,意为“因为、由于”。如: Thank you for helping me with my English. 谢谢你帮我学习英语。 Thank you for your last letter. 谢谢你上次的来信。 Thank you for teaching us so well. 感谢你如此尽心地教我们。 3. 表示动作的对象或接受者,意为“给……”、“对…… (而言)”。如: Let me pick it up for you. 让我为你捡起来。 Watching TV too much is bad for your health. 看电视太多有害于你的健康。 4. 表示时间、距离,意为“计、达”。如: I usually do the running for an hour in the morning. 我早晨通常跑步一小时。We will stay there for two days. 我们将在那里逗留两天。 5. 表示去向、目的,意为“向、往、取、买”等。如: let’s go for a walk. 我们出去散步吧。 I came here for my schoolbag.我来这儿取书包。 I paid twenty yuan for the dictionary. 我花了20元买这本词典。 6. 表示所属关系或用途,意为“为、适于……的”。如: It’s time for school. 到上学的时间了。 Here is a letter for you. 这儿有你的一封信。 7. 表示“支持、赞成”。如: Are you for this plan or against it? 你是支持还是反对这个计划? 8. 用于一些固定搭配中。如: Who are you waiting for? 你在等谁? For example, Mr Green is a kind teacher. 比如,格林先生是一位心地善良的老师。

延时子程序计算方法

学习MCS-51单片机，如果用软件延时实现时钟，会接触到如下形式的延时子程序：delay:mov R5,#data1 d1:mov R6,#data2 d2:mov R7,#data3 d3:djnz R7,d3 djnz R6,d2 djnz R5,d1 Ret 其精确延时时间公式：t=（2*R5*R6*R7+3*R5*R6+3*R5+3）*T （“*”表示乘法，T表示一个机器周期的时间）近似延时时间公式：t=2*R5*R6*R7 *T 假如data1,data2,data3分别为50，40，248，并假定单片机晶振为12M，一个机器周期为10-6S，则10分钟后，时钟超前量超过1.11秒，24小时后时钟超前159.876秒（约2分40秒）。这都是data1,data2,data3三个数字造成的，精度比较差，建议C描述。

上表中e=-1的行（共11行）满足（2*R5*R6*R7+3*R5*R6+3*R5+3）=999，999 e=1的行（共2行）满足（2*R5*R6*R7+3*R5*R6+3*R5+3）=1，000，001 假如单片机晶振为12M，一个机器周期为10-6S，若要得到精确的延时一秒的子程序，则可以在之程序的Ret返回指令之前加一个机器周期为1的指令（比如nop指令）， data1,data2,data3选择e=-1的行。比如选择第一个e=-1行，则精确的延时一秒的子程序可以写成： delay:mov R5,#167 d1:mov R6,#171 d2:mov R7,#16 d3:djnz R7,d3 djnz R6,d2

djnz R5,d1 nop ；注意不要遗漏这一句 Ret 附： #include"iostReam.h" #include"math.h" int x=1,y=1,z=1,a,b,c,d,e(999989),f(0),g(0),i,j,k; void main() { foR(i=1;i<255;i++) { foR(j=1;j<255;j++) { foR(k=1;k<255;k++) { d=x*y*z*2+3*x*y+3*x+3-1000000; if(d==-1) { e=d;a=x;b=y;c=z; f++; cout<<"e="<

常用介词用法(for to with of)

For的用法 1. 表示“当作、作为”。如: I like some bread and milk for breakfast. 我喜欢把面包和牛奶作为早餐。 What will we have for supper? 我们晚餐吃什么? 2. 表示理由或原因,意为“因为、由于”。如: Thank you for helping me with my English. 谢谢你帮我学习英语。 3. 表示动作的对象或接受者,意为“给……”、“对…… (而言)”。如: Let me pick it up for you. 让我为你捡起来。 Watching TV too much is bad for your health. 看电视太多有害于你的健康。 4. 表示时间、距离,意为“计、达”。如: I usually do the running for an hour in the morning. 我早晨通常跑步一小时。 We will stay there for two days. 我们将在那里逗留两天。 5. 表示去向、目的,意为“向、往、取、买”等。如: Let’s go for a walk. 我们出去散步吧。 I came here for my schoolbag.我来这儿取书包。 I paid twenty yuan for the dictionary. 我花了20元买这本词典。 6. 表示所属关系或用途,意为“为、适于……的”。如: It’s time for school. 到上学的时间了。 Here is a letter for you. 这儿有你的一封信。 7. 表示“支持、赞成”。如: Are you for this plan or against it? 你是支持还是反对这个计划? 8. 用于一些固定搭配中。如: Who are you waiting for? 你在等谁? For example, Mr Green is a kind teacher. 比如,格林先生是一位心地善良的老师。尽管for 的用法较多，但记住常用的几个就可以了。 to的用法: 一：表示相对，针对 be strange (common, new, familiar, peculiar) to This injection will make you immune to infection. 二：表示对比，比较 1：以-ior结尾的形容词，后接介词to表示比较，如：superior ,inferior,prior,senior,junior 2: 一些本身就含有比较或比拟意思的形容词，如equal，similar，equivalent，analogous A is similar to B in many ways.

of和for的用法

of 1....的,属于 One of the legs of the table is broken. 桌子的一条腿坏了。 Mr.Brown is a friend of mine. 布朗先生是我的朋友。 2.用...做成的;由...制成 The house is of stone. 这房子是石建的。 3.含有...的;装有...的 4....之中的;...的成员 Of all the students in this class,Tom is the best. 在这个班级中,汤姆是最优秀的。 5.(表示同位) He came to New York at the age of ten. 他在十岁时来到纽约。 6.(表示宾格关系) He gave a lecture on the use of solar energy. 他就太阳能的利用作了一场讲演。 7.(表示主格关系) We waited for the arrival of the next bus. 我们等待下一班汽车的到来。

I have the complete works of Shakespeare. 我有莎士比亚全集。 8.来自...的;出自 He was a graduate of the University of Hawaii. 他是夏威夷大学的毕业生。 9.因为 Her son died of hepatitis. 她儿子因患肝炎而死。 10.在...方面 My aunt is hard of hearing. 我姑妈耳朵有点聋。 11.【美】(时间)在...之前 12.(表示具有某种性质) It is a matter of importance. 这是一件重要的事。 For 1.为,为了 They fought for national independence. 他们为民族独立而战。 This letter is for you. 这是你的信。

单片机C延时时间怎样计算

C程序中可使用不同类型的变量来进行延时设计。经实验测试，使用unsigned char类型具有比unsigned int更优化的代码，在使用时应该使用unsigned char作为延时变量。以某晶振为12MHz的单片机为例，晶振为12M H z即一个机器周期为1u s。一. 500ms延时子程序程序: void delay500ms(void) { unsigned char i,j,k; for(i=15;i>0;i--) for(j=202;j>0;j--) for(k=81;k>0;k--); } 计算分析: 程序共有三层循环一层循环n:R5*2 = 81*2 = 162us DJNZ 2us 二层循环m:R6*(n+3) = 202*165 = 33330us DJNZ 2us + R5赋值 1us = 3us 三层循环: R7*(m+3) = 15*33333 = 499995us DJNZ 2us + R6赋值 1us = 3us

循环外: 5us 子程序调用 2us + 子程序返回2us + R7赋值 1us = 5us 延时总时间 = 三层循环 + 循环外 = 499995+5 = 500000us =500ms 计算公式:延时时间=[(2*R5+3)*R6+3]*R7+5 二. 200ms延时子程序程序: void delay200ms(void) { unsigned char i,j,k; for(i=5;i>0;i--) for(j=132;j>0;j--) for(k=150;k>0;k--); } 三. 10ms延时子程序程序: void delay10ms(void) { unsigned char i,j,k; for(i=5;i>0;i--) for(j=4;j>0;j--) for(k=248;k>0;k--);

for和to区别

1.表示各种“目的”，用for （1）What do you study English for 你为什么要学英语？（2）went to france for holiday. 她到法国度假去了。（3）These books are written for pupils. 这些书是为学生些的。（4）hope for the best, prepare for the worst. 作最好的打算，作最坏的准备。 2．“对于”用for （1）She has a liking for painting. 她爱好绘画。（2）She had a natural gift for teaching. 她对教学有天赋/ 3．表示“赞成、同情”，用for （1）Are you for the idea or against it 你是支持还是反对这个想法？（2）He expresses sympathy for the common people.. 他表现了对普通老百姓的同情。（3）I felt deeply sorry for my friend who was very ill. 4. 表示“因为，由于”（常有较活译法），用for （1）Thank you for coming. 谢谢你来。

（2）France is famous for its wines. 法国因酒而出名。 5．当事人对某事的主观看法，“对于（某人），对…来说”，（多和形容词连用），用介词to，不用for. （1）He said that money was not important to him. 他说钱对他并不重要。（2）To her it was rather unusual. 对她来说这是相当不寻常的。（3）They are cruel to animals. 他们对动物很残忍。 6．和fit, good, bad, useful, suitable 等形容词连用，表示“适宜，适合”，用for。（1）Some training will make them fit for the job. 经过一段训练，他们会胜任这项工作的。（2）Exercises are good for health. 锻炼有益于健康。（3）Smoking and drinking are bad for health. 抽烟喝酒对健康有害。（4）You are not suited for the kind of work you are doing. 7. 表示不定式逻辑上的主语，可以用在主语、表语、状语、定语中。（1）It would be best for you to write to him. （2） The simple thing is for him to resign at once.

51单片机延时时间计算和延时程序设计

一、关于单片机周期的几个概念 ●时钟周期时钟周期也称为振荡周期，定义为时钟脉冲的倒数（可以这样来理解，时钟周期就是单片机外接晶振的倒数，例如12MHz的晶振，它的时间周期就是1/12 us），是计算机中最基本的、最小的时间单位。在一个时钟周期内，CPU仅完成一个最基本的动作。 ●机器周期完成一个基本操作所需要的时间称为机器周期。以51为例,晶振12M，时钟周期(晶振周期)就是(1/12)μs，一个机器周期包执行一条指令所需要的时间，一般由若干个机器周期组成。指令不同，所需的机器周期也不同。对于一些简单的的单字节指令，在取指令周期中，指令取出到指令寄存器后，立即译码执行，不再需要其它的机器周期。对于一些比较复杂的指令，例如转移指令、乘法指令，则需要两个或者两个以上的机器周期。 1.指令含义 DJNZ：减1条件转移指令这是一组把减1与条件转移两种功能结合在一起的指令，共2条。 DJNZ Rn，rel ；Rn←（Rn）-1 ；若（Rn）=0，则PC←（PC）+2 ；顺序执行；若（Rn）≠0，则PC←（PC）+2+rel，转移到rel所在位置DJNZ direct，rel ；direct←（direct）-1 ；若（direct）= 0，则PC←（PC）+3；顺序执行；若（direct）≠0，则PC←（PC）+3+rel，转移到rel 所在位置 2.DJNZ Rn,rel指令详解例：

MOV R7，#5 DEL:DJNZ R7,DEL; rel在本例中指标号DEL 1.单层循环由上例可知，当Rn赋值为几，循环就执行几次，上例执行5次，因此本例执行的机器周期个数=1（MOV R7，#5）+2（DJNZ R7,DEL）×5=11，以12MHz的晶振为例，执行时间（延时时间）=机器周期个数×1μs=11μs，当设定立即数为0时，循环程序最多执行256次，即延时时间最多256μs。 2.双层循环 1）格式： DELL:MOV R7，#bb DELL1:MOV R6，#aa DELL2:DJNZ R6,DELL2; rel在本句中指标号DELL2 DJNZ R7,DELL1; rel在本句中指标号DELL1 注意：循环的格式，写错很容易变成死循环，格式中的Rn和标号可随意指定。 2）执行过程

双宾语 to for的用法

1.两者都可以引出间接宾语，但要根据不同的动词分别选用介词to 或for：(1) 在give, pass, hand, lend, send, tell, bring, show, pay, read, return, write, offer, teach, throw 等之后接介词to。如：请把那本字典递给我。正：Please hand me that dictionary. 正：Please hand that dictionary to me. 她去年教我们的音乐。正：She taught us music last year. 正：She taught music to us last year. (2) 在buy, make, get, order, cook, sing, fetch, play, find, paint, choose,prepare, spare 等之后用介词for 。如：他为我们唱了首英语歌。正：He sang us an English song. 正：He sang an English song for us. 请帮我把钥匙找到。正：Please find me the keys. 正：Please find the keys for me. 能耽搁你几分钟吗(即你能为我抽出几分钟吗)? 正：Can you spare me a few minutes? 正：Can you spare a few minutes for me? 注：有的动词由于搭配和含义的不同，用介词to 或for 都是可能的。如：do sb a favour＝do a favour for sb 帮某人的忙 do sb harm＝do harm to sb 对某人有害

双宾语tofor的用法

1. 两者都可以引出间接宾语，但要根据不同的动词分别选用介词to 或for： (1) 在give, pass, hand, lend, send, tell, bring, show, pay, read, return, write, offer, teach, throw 等之后接介词to。如：请把那本字典递给我。正：Please hand me that dictionary. 正：Please hand that dictionary to me. 她去年教我们的音乐。正：She taught us music last year. 正：She taught music to us last year. (2) 在buy, make, get, order, cook, sing, fetch, play, find, paint, choose,prepare, spare 等之后用介词for 。如：他为我们唱了首英语歌。正：He sang us an English song. 正：He sang an English song for us. 请帮我把钥匙找到。正：Please find me the keys. 正：Please find the keys for me. 能耽搁你几分钟吗(即你能为我抽出几分钟吗)? 正：Can you spare me a few minutes? 正：Can you spare a few minutes for me? 注：有的动词由于搭配和含义的不同，用介词to 或for 都是可能的。如： do sb a favou r do a favour for sb 帮某人的忙 do sb harnn= do harm to sb 对某人有害

for和of的用法

for的用法： 1. 表示“当作、作为”。如: I like some bread and milk for breakfast. 我喜欢把面包和牛奶作为早餐。 What will we have for supper? 我们晚餐吃什么? 2. 表示理由或原因,意为“因为、由于”。如: Thank you for helping me with my English. 谢谢你帮我学习英语。 Thank you for your last letter. 谢谢你上次的来信。 Thank you for teaching us so well. 感谢你如此尽心地教我们。 3. 表示动作的对象或接受者,意为“给……”、“对…… (而言)”。如: Let me pick it up for you. 让我为你捡起来。 Watching TV too much is bad for your health. 看电视太多有害于你的健康。 4. 表示时间、距离,意为“计、达”。如:

I usually do the running for an hour in the morning. 我早晨通常跑步一小时。 We will stay there for two days. 我们将在那里逗留两天。 5. 表示去向、目的,意为“向、往、取、买”等。如: Let’s go for a walk. 我们出去散步吧。 I came here for my schoolbag.我来这儿取书包。 I paid twenty yuan for the dictionary. 我花了20元买这本词典。 6. 表示所属关系或用途,意为“为、适于……的”。如: It’s time for school. 到上学的时间了。 Here is a letter for you. 这儿有你的一封信。 7. 表示“支持、赞成”。如: Are you for this plan or against it? 你是支持还是反对这个计划? 8. 用于一些固定搭配中。如:

英语形容词和of for 的用法

加入收藏夹主题：介词试题It’s + 形容词 + of sb. to do sth.和It’s + 形容词 + for sb. to do sth.的用法区别。内容： It's very nice___pictures for me. A.of you to draw B.for you to draw C.for you drawing C.of you drawing 提交人：杨天若时间：1/23/2008 20:5:54 主题：for 与of 的辨别内容：It's very nice___pictures for me. A.of you to draw B.for you to draw C.for you drawing C.of you drawing 答：选A 解析：该题考查的句型It’s + 形容词+ of sb. to do sth.和It’s +形容词+ for sb. to do sth.的用法区别。 “It’s + 形容词+ to do sth.”中常用of或for引出不定式的行为者，究竟用of sb.还是用for sb.，取决于前面的形容词。 1) 若形容词是描述不定式行为者的性格、品质的，如kind，good，nice，right，wrong，clever，careless，polite，foolish等，用of sb. 例： It’s very kind of you to help me. 你能帮我，真好。 It’s clever of you to work out the maths problem. 你真聪明，解出了这道数学题。 2) 若形容词仅仅是描述事物，不是对不定式行为者的品格进行评价，用for sb.，这类形容词有difficult，easy，hard，important，dangerous，（im）possible等。例： It’s very dangerous for children to cross the busy street. 对孩子们来说，穿过繁忙的街道很危险。 It’s difficult for u s to finish the work. 对我们来说，完成这项工作很困难。 for 与of 的辨别方法：用介词后面的代词作主语，用介词前边的形容词作表语，造个句子。如果道理上通顺用of，不通则用for. 如： You are nice.(通顺，所以应用of)。 He is hard.(人是困难的，不通，因此应用for.) 由此可知，该题的正确答案应该为A项。提交人：f7_liyf 时间：1/24/2008 11:18:42

to和for的用法有什么不同(一)

to和for的用法有什么不同（一）一、引出间接宾语时的区别两者都可以引出间接宾语，但要根据不同的动词分别选用介词to 或for，具体应注意以下三种情况： 1. 在give, pass, hand, lend, send, tell, bring, show, pay, read, return, write, offer, teach, throw 等之后接介词to。如：请把那本字典递给我。正：Please hand me that dictionary. 正：Please hand that dictionary to me. 她去年教我们的音乐。正：She taught us music last year. 正：She taught music to us last year. 2. 在buy, make, get, order, cook, sing, fetch, play, find, paint, choose, prepare, spare 等之后用介词for 。如：他为我们唱了首英语歌。正：He sang us an English song. 正：He sang an English song for us. 请帮我把钥匙找到。正：Please find me the keys. 正：Please find the keys for me. 能耽搁你几分钟吗(即你能为我抽出几分钟吗)? 正：Can you spare me a few minutes?

正：Can you spare a few minutes for me? 3. 有的动词由于用法和含义不同，用介词to 或for 都是可能的。如： do sb a favor＝do a favor for sb 帮某人的忙 do sb harm＝do harm to sb 对某人有害在有的情况下，可能既不用for 也不用to，而用其他的介词。如： play sb a trick＝play a trick on sb 作弄某人请比较： play sb some folk songs＝play some folk songs for sb 给某人演奏民歌有时同一个动词，由于用法不同，所搭配的介词也可能不同，如leave sbsth 这一结构，若表示一般意义的为某人留下某物，则用介词for 引出间接宾语，即说leave sth for sb；若表示某人死后遗留下某物，则用介词to 引出间接宾语，即说leave sth to sb。如： Would you like to leave him a message? / Would you like to leave a message for him? 你要不要给他留个话？ Her father left her a large fortune. / Her father left a large fortune to her. 她父亲死后给她留下了一大笔财产。二、表示目标或方向的区别两者均可表示目标、目的地、方向等，此时也要根据不同动词分别对待。如： 1. 在come, go, walk, move, fly, ride, drive, march, return 等动词之后通常用介词to 表示目标或目的地。如： He has gone to Shanghai. 他到上海去了。 They walked to a river. 他们走到一条河边。

延时计算

t=n*(分频/f) t：是你所需的延时时间 f：是你的系统时钟(SYSCLK) n：是你所求，用于设计延时函数的程序如下： void myDelay30s() reentrant { unsigned inti,k; for(i=0;i<4000;i++) /*系统时钟我用的是24.576MHZ，分频是12分频，达到大约10s延时*/ for(k=0;k<8000;k++); } //n=i*k |评论 2012-2-18 20:03 47okey|十四级 debu(g调试），左侧有运行时间。在你要测试的延时子函数外设一断点，全速运行到此断点。记下时间，再单步运行一步，跳到下一步。再看左侧的运行时间，将这时间减去上一个时间，就是延时子函数的延时时间了。不知能不能上图。追问在delayms处设置断点，那么对应的汇编语言LCALL是否被执行呢？还有，问问您，在C8051F020单片机中，MOV指令都是多少指令周期呢？我在KEIL下仿真得出的结果，与我通过相应的汇编语言分析的时间，总是差了很多。回答 C编译时，编译器都要先变成汇编。只想知道延时时间，汇编的你可以不去理会。只要看运行时间就好了。 at8051单片机12m晶振下，机器周期为1us，而c8051 2m晶振下为1us。keil 调试里频率默认为24m，你要设好晶振频率。

202X中考英语：to和for的区别与用法.doc

202X中考英语：to和for的区别与用法中考栏目我为考生们整理了“202X中考英语：to和for的区别与用法”，希望能帮到大家，想了解更多考试资讯，本网站的及时更新哦。 202X中考英语：to和for的区别与用法 to和for的区别与用法是什么一般情况下, to后面常接对象; for后面表示原因与目的为多。 Thank you for helping me. Thanks to all of you. to sb. 表示对某人有直接影响比如，食物对某人好或者不好就用to; for 表示从意义、价值等间接角度来说，例如对某人而言是重要的，就用for. for和to这两个介词，意义丰富，用法复杂。这里仅就它们主要用法进行比较。 1. 表示各种“目的” 1. What do you study English for? 你为什么要学英语? 2. She went to france for holiday. 她到法国度假去了。 3. These books are written for pupils. 这些书是为学生些的。 4. hope for the best, prepare for the worst. 作最好的打算，作最坏的准备。

2.对于 1.She has a liking for painting. 她爱好绘画。 2.She had a natural gift for teaching. 她对教学有天赋。 3.表示赞成同情，用for不用to. 1. Are you for the idea or against it? 你是支持还是反对这个想法? 2. He expresses sympathy for the common people.. 他表现了对普通老百姓的同情。 3. I felt deeply sorry for my friend who was very ill. 4 for表示因为，由于(常有较活译法) 1.Thank you for coming. 谢谢你来。 2. France is famous for its wines. 法国因酒而出名。 5.当事人对某事的主观看法，对于(某人)，对?来说(多和形容词连用)用介词to，不用for.. He said that money was not important to him. 他说钱对他并不重要。 To her it was rather unusual. 对她来说这是相当不寻常的。 They are cruel to animals. 他们对动物很残忍。

keep的用法及of 、for sb.句型区别

keep的用法 1. 用作及物动词 ①意为"保存；保留；保持；保守"。如： Could you keep these letters for me, please? 你能替我保存这些信吗？ ②意为"遵守；维护"。如： Everyone must keep the rules. 人人必须遵守规章制度。 The teacher is keeping order in class.老师正在课堂上维持秩序。 ③意为"使……保持某种(状态、位置或动作等)"。这时要在keep的宾语后接补足语，构成复合宾语。其中宾语补足语通常由形容词、副词、介词短语、现在分词和过去分词等充当。如：例：We should keep our classroom clean and tidy.(形容词) 我们应保持教室整洁干净。 You'd better keep the child away from the fire.(副词)你最好让孩子离火远一点。 The bad weather keeps us inside the house.(介词短语)坏天气使我们不能出门。 Don't keep me waiting for long.(现在分词)别让我等太久。 The other students in the class keep their eyes closed.(过去分词) 班上其他同学都闭着眼睛。 2. 用作连系动词构成系表结构：keep＋表语，意为"保持，继续(处于某种状态)"。其中表语可用形容词、副词、介词短语等充当。如：例：You must look after yourself and keep healthy.(形容词) 你必须照顾好自己，保持身体健康。 Keep off the grass.(副词)请勿践踏草地。 Traffic in Britain keeps to the left.(介词短语)英国的交通是靠左边行驶的。注意：一般情况下，keep后接形容词较为多见。再如： She knew she must keep calm.她知道她必须保持镇静。 Please keep silent in class.课堂上请保持安静。 3. ①keep doing sth. 意为"继续干某事"，表示不间断地持续干某事，keep后不能接不定式或表示静止状态的v-ing形式，而必须接延续性的动词。例：He kept working all day, because he wanted to finish the work on time. 他整天都在不停地工作，因为他想准时完成工作。 Keep passing the ball to each other, and you'll be OK.坚持互相传球，你们就

to of和for的区别

to , of 和for的区别 1.to有到的意思，常常和go，come，get连用引出地点。Go to school , go to the shop , go to the cinema. 常见的短语：the way to 去---的路 On one’s way to 在某人去---的路上以上的用法中，当地点是副词home，here，there等是to 要去掉。如：get home，the way here To后跟动词原形，是不定式的标志 It is +形容词+(for/of +人+)to do sth.(括号内部分可以省略) It is easy for me to learn English. It is very kind of you to lend me your money. 当形容词表示人的行为特征时用of表示to do的性质时用for Want, hope ,decide, plan , try , fail等词后跟to do I want to join the swimming club. Would like to do I’d like to play basketball with them. It is time to have a break. Next to , close to , from ---to--- 2.for 为，表示目的。 Thank you for Buy sth for sb =buy sb sth It is time for bed. Here is a letter for you.

I will study for our country. 3.of表示所属关系意思是：---的 a map of the world a friend of mine

for和of引导的不定式结构的区别

for和of引导的不定式结构的区别不定式是一种非谓语动词，不能单独作谓语，因此没有语法上的主语。但由于不定式表示的是动作，在意义上可以有它的主体。我们称之为逻辑主语。提起不定式逻辑主语，人们首先想到的会是“for+名词（宾格代词）+不定式”的复合结构。如：It is important for us to study English well．然而，有时不定式的逻辑主语须要用“of+名词（代词宾格）”才行。例如：It is kind of you to help me．而不能说：It is kind for you to help me．在选择介词“for”还是“of”时，人们往往总是凭感觉而定。有时受习惯影响，多选介词“for”。于是常出现这样的错误：It was careless for him to lose his way．It is cruel for you to do so．由于众多语法书对这种结构中使用“for”与“of”的区别介绍甚少，一些人对其概念认识尚不完全清楚，笔者认为有必要就这一问题作些探讨与介绍。一、在句中的语法作用不同 a．不定式for结构在句中可以作主、宾、表、定、状、同位语： 1．It is easy for Tom to do this work．（主语）汤姆做此工作是容易的。 2．I'd like for him to come here．（宾语）我喜欢他来这里。 3．His idea is for us to travel in two different groups．（表语）他的想法是：我们分成两组旅行。 4．Have you heard about the plan for you to go abroad．（定语）你听到让你出国的计划吗？ 5．The word is too difficult for him to pronounce well．（状语）这单词太难，他念不准。 6．In the most schools，it is the custom for the headmaster to declare the newterm start．在大部分学校，校长宣布新学期开始是一个习惯。 b．不定式of结构只能在句中作主语。 1．It was careless of him to leave his umbrella in the train．他把伞丢在火车上真是太粗心了。 2．It is awfully good of you to come to see me off at the station．谢谢你来车站送我。二、逻辑主语的名词有所不同