全文获取类型
收费全文 | 880篇 |
免费 | 110篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 4篇 |
妇产科学 | 54篇 |
基础医学 | 122篇 |
口腔科学 | 10篇 |
临床医学 | 153篇 |
内科学 | 131篇 |
皮肤病学 | 7篇 |
神经病学 | 130篇 |
特种医学 | 37篇 |
外科学 | 117篇 |
综合类 | 37篇 |
一般理论 | 1篇 |
预防医学 | 96篇 |
眼科学 | 2篇 |
药学 | 73篇 |
中国医学 | 1篇 |
肿瘤学 | 22篇 |
出版年
2021年 | 13篇 |
2020年 | 6篇 |
2019年 | 9篇 |
2018年 | 11篇 |
2016年 | 9篇 |
2015年 | 8篇 |
2014年 | 11篇 |
2013年 | 27篇 |
2012年 | 32篇 |
2011年 | 60篇 |
2010年 | 23篇 |
2009年 | 18篇 |
2008年 | 38篇 |
2007年 | 48篇 |
2006年 | 33篇 |
2005年 | 43篇 |
2004年 | 36篇 |
2003年 | 47篇 |
2002年 | 57篇 |
2001年 | 37篇 |
2000年 | 37篇 |
1999年 | 24篇 |
1998年 | 10篇 |
1997年 | 15篇 |
1996年 | 21篇 |
1995年 | 16篇 |
1994年 | 10篇 |
1993年 | 9篇 |
1992年 | 24篇 |
1991年 | 10篇 |
1990年 | 12篇 |
1989年 | 7篇 |
1988年 | 14篇 |
1987年 | 14篇 |
1986年 | 13篇 |
1985年 | 10篇 |
1984年 | 10篇 |
1983年 | 8篇 |
1982年 | 10篇 |
1980年 | 7篇 |
1979年 | 7篇 |
1976年 | 6篇 |
1975年 | 6篇 |
1974年 | 6篇 |
1968年 | 8篇 |
1967年 | 7篇 |
1964年 | 5篇 |
1935年 | 5篇 |
1933年 | 5篇 |
1929年 | 7篇 |
排序方式: 共有999条查询结果,搜索用时 15 毫秒
61.
Karlowsky JA Jones ME Thornsberry C Critchley I Kelly LJ Sahm DF 《International journal of antimicrobial agents》2001,18(2):121-127
In the United States, trimethoprim-sulphamethoxazole (TMP-SMX) is the recommended first-line treatment for uncomplicated urinary tract infections (UTIs) in females, in regions with resistance rates of <10-20%. Unfortunately, current data on regional resistance is often not readily available to physicians and regional variability in resistance remains largely unknown. This report presents antimicrobial susceptibility data for TMP-SMX and three other commonly tested antimicrobials organized by state and region to demonstrate current regional variability in resistance in the US. In the last quarter of 1999, 5739 fresh clinical isolates of Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis and Staphylococcus saprophyticus were collected from 202 laboratories throughout the US. Susceptibility testing was performed against TMP-SMX, cephalothin, nitrofurantoin and ciprofloxacin using broth microdilution. Data were analyzed by patient age and specimen source, and by state and region. In the US as a whole, resistance to TMP-SMX was 16.8% for E. coli, 7.8% for K. pneumoniae, 12.1% for P. mirabilis and 3.0% for S. saprophyticus, but these rates showed considerable regional variation. By state, E. coli resistance ranged from 7.4% in Pennsylvania to 33.3% in Iowa (among states with > or =50 isolates tested). Regionally, resistance for all uropathogens taken together ranged from 8.5% in East South-Central to 22.8% in West South-Central. Ciprofloxacin demonstrated the broadest activity of the antimicrobials tested and was more active than TMP-SMX against all pathogens. Resistance to TMP-SMX among E. coli now approaches or exceeds 20% in some areas. As resistance among uropathogens reaches clinically significant levels in many areas, continued regional surveillance is essential to ensure the provision of effective empiric therapy for urinary tract infections. 相似文献
62.
63.
Analysis of ciprofloxacin activity against Streptococcus pneumoniae after 10 years of use in the United States
下载免费PDF全文
![点击此处可从《Antimicrobial agents and chemotherapy》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Sahm DF Peterson DE Critchley IA Thornsberry C 《Antimicrobial agents and chemotherapy》2000,44(9):2521-2524
As the most commonly used fluoroquinolone in the United States since 1987, ciprofloxacin has exerted the greatest selective pressure on S. pneumoniae and provides a valuable marker to evaluate the actual and potential emergence of fluoroquinolone resistance in this species. Analysis of susceptibility results obtained with 5,640 strains collected from throughout the United States showed that only 16 (0.3%) of the isolates demonstrated MICs of > or =4 microg/ml. The prevalence of this phenotype was significantly higher (P < 0.05) among penicillin-resistant populations, among isolates from patients >64 years old, and among respiratory isolates. However, >99% of strains had MICs of <4 microg/ml regardless of the risk group examined, and the MIC population distributions were the same for each risk group. These findings demonstrate that the phenotype of a MIC of > or =4 microg/ml remains uncommon after 10 years of ciprofloxacin use; however, these findings are no reason to become complacent with regard to appropriate use of fluoroquinolones and the need to carefully track resistance trends. Equally important is careful analysis of data that result from surveillance in terms of risk factors and other associated trends so that resistance and susceptibility, and their consequences, are neither over- nor underestimated. 相似文献
64.
65.
Jönsson A Chan JC Rydberg T Vaaler S Hallengren B Cockram CS Critchley JA Melander A 《European journal of clinical pharmacology》2000,55(10):721-727
Objective: We analysed the kinetics and effects of glibenclamide (Gb) on glucose, insulin and proinsulin secretion in two ethnic groups
(10 in each) of type-2 diabetic patients, one of Caucasian, the other of Chinese origin.
Background: Diabetes mellitus type 2 is a global disease affecting all ethnic groups. There are ethnic differences in both the prevalence
and metabolic characteristics of the disease. Important interethnic pharmacodynamic and pharmacokinetic differences have been
reported for several drugs. With few exceptions, detailed studies on sulphonylurea are lacking.
Material and methods: The patients were studied on two occasions when either no Gb (control) or 1.25 mg Gb was administered i.v., immediately
before the administration of a 75-g oral glucose tolerance test. Concentrations of insulin and proinsulin were determined
by means of radioimmunoassay without cross-reactivities. Gb concentration was determined using high-performance liquid chromatography.
Pharmacodynamic results were calculated using net areas under the curves, with basal values set as zero. A P value less than 0.05 was considered significant.
Results: When glucose was administered orally without Gb, Chinese patients had higher plasma glucose increases at 10 min (7.6 mmol/l × min
vs 2.6 mmol/l × min) and higher increases of plasma insulin levels than Caucasians at both 10 min (198 pmol/l × min vs 54 pmol/l × min)
and 30 min (2286 pmol/l × min vs 1198 pmol/l × min). When Gb was administered, the plasma glucose increases were reduced,
and the increases of serum insulin and proinsulin levels were greater in both ethnic groups. Compared with the basal values
(−1 min), proinsulin/insulin ratios (RPI) were lowest at 10–30 min, followed by an increase. Chinese patients had higher increases
of serum insulin levels at 10 min (1109 pmol/l × min vs 550 pmol/l × min) and a lower RPI at 30 min (6.0% vs 7.6%) and 240 min
(15.0% vs 21.0%) relative to Caucasians. Serum Gb data were best fitted to a biexponential i.v. model. There were no interethnic
differences in any of the pharmacokinetic parameters.
Conclusion: In summary, following oral glucose administration without Gb, Chinese type-2 diabetic patients had higher plasma insulin
levels but also higher plasma glucose levels during the first 10 min, which might reflect reduced insulin sensitivity or more
rapid glucose absorption. Gb augmented glucose-induced release of both insulin and proinsulin in both ethnic groups; the effect
on insulin secretion was more pronounced. In conclusion, minor pharmacodynamic but no pharmacokinetic differences were found
between the two groups. It seems appropriate to employ the same dosage principles when using Gb in Caucasians and Chinese.
Received: 15 June 1999 / Accepted in revised form: 9 August 1999 相似文献
66.
Preduodenal mechanisms in initiating gallbladder emptying in man 总被引:2,自引:0,他引:2
S Ellenbogen S A Jenkins J S Grime M Critchley C R Mackie J N Baxter 《The British journal of surgery》1988,75(10):940-945
The existence of preduodenal phases of gallbladder emptying in normal volunteers was investigated by evaluating the effect of sham feeding a sandwich (chew and spit) (n = 15), the sight and smell of food followed by sham feeding a cooked meal (n = 15), and gastric distension (intragastric balloon tube) (n = 9) on gallbladder emptying and comparing these responses with those after ingestion of a standard meal (n = 14). A control group given no intestinal stimuli were studied to determine the frequency of spontaneous emptying during fasting (n = 18). 99mTc-EHIDA (2,6 diethylphenylcarbamoylmethyliminodiacetic acid) was used as the biliary tracer. The frequency of gallbladder emptying during fasting was 0.0045/min. Thus, in any 20 min period emptying occurred spontaneously in only about 1 in 11 volunteers. Significant emptying (greater than 5 per cent over 20 min) occurred in 8 out of 15 volunteers after sham feeding a sandwich (P less than 0.001 versus control), in 8 out of 15 volunteers after sham feeding a cooked meal (P = 1.0 versus sandwich sham feed, n.s.), in 6 out of 9 volunteers after gastric distension (P less than 0.001 versus control) and in 14 out of 14 volunteers after meal ingestion. The rate of emptying was significantly greater in the gastric distension and meal ingestion groups compared with other groups (P less than 0.05). However, the emptying rate after sham feeding was not significantly different from spontaneous gallbladder emptying (P greater than 0.05, n.s.). There was no significant difference in time to onset of emptying between the four stimulus groups (P greater than 0.05, n.s.). These results suggest that pre-duodenal stimuli can evoke gallbladder emptying in man, although the precise physiological significance of this phenomenon remains to be established. 相似文献
67.
M Critchley S Brownless M Patten P J McLaughlin P M Tromans I W McDicken P M Johnson 《Clinical radiology》1986,37(2):107-112
A murine monoclonal antibody, H317, specific for placental-type alkaline phosphatase was labelled with 123I and assessed as an imaging agent using a gamma camera computer system in 18 patients suspected of possible recurrent or metastatic ovarian cancer 1-4 years after removal of the primary tumour. Four patterns of distribution were visible: (1) normal uptake; (2) focal accumulation; (3) diffuse uptake; and (4) 'cold' areas. Six patients, five of whom were clinically negative for ovarian cancer, had normal scans; 11 patients, eight of whom were clinically positive, had increased uptake. One patient had visibly 'cold' areas. Findings were confirmed, where possible, at surgery. 相似文献
68.
黄芪总黄酮对扑热息痛所致小鼠肝损伤防护作用的研究 总被引:21,自引:3,他引:21
汪德清 丁保国 马艳青 赵海潞 Thomas G Neil Tomlinson Brian 田亚平 王成彬 Critchley Julian AJH 《中国中药杂志》2001,26(7):483-486
目的 :研究黄芪总黄酮 (TFA)对扑热息痛所致肝损伤的防护作用。方法 :用 1%羧甲基纤维素钠 10ml·kg-1,TFA10 0mg·kg-1或维生素C (Ascorbicacid ,VC) 1000mg·kg-1给小鼠灌胃 1h后 ,灌扑热息痛 1000mg·kg-1,观察小鼠死亡率的变化 ;提前 1h用不同剂量的TFA或VC处理后 ,再灌 400mg·kg-1的扑热息痛 ,检测血清酶学和肝脏组织学的改变。结果 :给小鼠扑热息痛 1000mg·kg-1灌胃组 ,24h后可致 80 %小鼠死亡 ;提前 1h用TFA10 0mg·kg-1或VC灌胃其死亡率可分别下降至 20%和0%。血清转氨酶 (ALT)和病理切片显示当给 400mg·kg-1扑热息痛灌胃 24h后即可引起严重肝损伤 (ALT升高和肝组织大面积坏死 ,P<0.001)。TFA或VC预防组 (提前1h给药)的肝损伤程度与对照组比较明显减轻 ,其作用强度与药物浓度成正比。结论 :TFA对扑热息痛所致肝损伤有保护作用。 相似文献
69.
Factors predicting the age when type 2 diabetes is diagnosed in Hong Kong Chinese subjects 总被引:7,自引:0,他引:7
Lee SC Ko GT Li JK Chow CC Yeung VT Critchley JA Cockram CS Chan JC 《Diabetes care》2001,24(4):646-649
OBJECTIVE: To examine the factors predicting age at diagnosis of type 2 diabetes in Hong Kong Chinese. RESEARCH DESIGN AND METHODS: The relationships between age at diagnosis and parental history of diabetes as well as an array of clinical and metabolic factors were examined using a hospital clinic-based diabetes registry involving 3,414 index patients with type 2 diabetes Patterns of age at diagnosis in successive generations were also examined using 21 affected child-parent pairs and 7 affected child-parent-grandparent trios. RESULTS: Approximately 29% of the index patients were diagnosed with type 2 diabetes at < or = 35 years of age (hereby defined as early-onset). Compared with the patients diagnosed at >35 years of age (hereby defined as late-onset) the early-onset patients had higher rates of positive paternal (16 vs. 5%) and maternal (22 vs. 12%) history of diabetes (both at P < 0.01) and had poorer metabolic profiles. In the overall index patients, male sex, higher HbA1c waist-to-hip ratio (WHR), and systolic blood pressure (sBP); lower HDL cholesterol level; and a positive paternal was well as maternal history of diabetes predicted younger age at diagnosis. More senior age and higher BMI and diastolic blood pressure predicted olderq age at diagnosis. Predictors for younger age at diagnosis in the male patients were higher HbA1c and sBP and a positive paternal history of diabetes Predictors for younger age at diagnosis in the female patients were higher HbA1c WHR, and sBP and a paternal as well as maternal history of diabetes. In the affected child parent pairs and clild-parent-grandparent trios there was a decrease in age at diagnosis in successive generations. CONCLUSIONS: Our data indicate that both familial (possibly genetic) and metabolic factors affect the age of onset of type 2 diabetes in the Chinese population. The results also suggest an onset and progression pattern of the disease that is compatible with the phenomenon of anticipation. 相似文献
70.
Dana Maki Ebrahim Rajab Paul J. Watson Duncan J. Critchley 《Disability and rehabilitation》2017,39(3):272-280
Purpose To translate and cross-culturally adapt the Back Beliefs Questionnaire (BBQ) into modern standard Arabic and examine its validity, acceptability and reliability in Arabic-speaking patients with low back pain (LBP). Method The BBQ was forward, back-translated and reviewed by an expert committee. Seventeen bilingual patients completed Arabic and English BBQs. LBP patients (n?=?199) completed the Arabic BBQ. Sixty-four repeated it a week later, and 151 completed the Arabic Fear-avoidance Beliefs Questionnaire (FABQ). Results The expert committee followed advice from the developers to maintain Arabic equivalence of “back trouble(s)”. Patients found the questionnaire comprehensible and acceptable. Agreement between the English and Arabic versions of the BBQ was acceptable, ICC?= 0.65 (0.25–0.86). Most item-by-item agreement ranged from fair to moderate (K?=?0.12–0.54). Mean (SD) of BBQ, FABQ total, work and physical activity subscales were 25.31(6.13), 44.76(19.49), 21.17(10.10) and 13.95(6.65). The BBQ correlated with the FABQ at r?=??0.33, work subscale r?=??0.29 and physical activity r?=??0.30 (all p?0.01). Cronbach’s α?=?0.73 indicated high internal consistency. Test–retest reliability was high, ICC?=?0.80 (0.68–0.87). Item-by-item agreement ranged from fair to acceptable (K?=?0.31–0.66). Conclusions The Arabic BBQ has good comprehensibility and acceptability, acceptable agreement with the English BBQ, high internal consistency and test–retest reliability. We recommend its use with Arabic-speaking LBP patient to determine their beliefs and attitudes about their back pain, as they have been shown to be important predictors of persistent LBP disability.
- Implications for Rehabilitation
There are limited valid and reliable outcome measures for back pain in Arabic. The Back Beliefs Questionnaire (BBQ) is a tool that measures attitudes and beliefs about back pain.
We recommend the use of our valid and reliable, translated and cross-culturally adapted tool with Arabic-speaking patients.
The tool can measure attitudes and beliefs concerning the future consequences of LBP, with regards to recovery and return to work in this sample.
Findings will improve back pain management options aimed at reducing back pain disability though challenging and modifying beliefs in the Middle East or with migrant populations in the West.