全文获取类型
收费全文 | 4913篇 |
免费 | 532篇 |
国内免费 | 253篇 |
专业分类
耳鼻咽喉 | 24篇 |
儿科学 | 362篇 |
妇产科学 | 115篇 |
基础医学 | 710篇 |
口腔科学 | 67篇 |
临床医学 | 567篇 |
内科学 | 854篇 |
皮肤病学 | 64篇 |
神经病学 | 464篇 |
特种医学 | 158篇 |
外科学 | 1072篇 |
综合类 | 105篇 |
预防医学 | 459篇 |
眼科学 | 51篇 |
药学 | 321篇 |
中国医学 | 3篇 |
肿瘤学 | 302篇 |
出版年
2022年 | 32篇 |
2021年 | 70篇 |
2019年 | 67篇 |
2018年 | 93篇 |
2017年 | 54篇 |
2016年 | 68篇 |
2015年 | 70篇 |
2014年 | 85篇 |
2013年 | 144篇 |
2012年 | 201篇 |
2011年 | 234篇 |
2010年 | 104篇 |
2009年 | 126篇 |
2008年 | 252篇 |
2007年 | 260篇 |
2006年 | 283篇 |
2005年 | 255篇 |
2004年 | 253篇 |
2003年 | 210篇 |
2002年 | 223篇 |
2001年 | 218篇 |
2000年 | 202篇 |
1999年 | 152篇 |
1998年 | 92篇 |
1997年 | 73篇 |
1996年 | 80篇 |
1995年 | 72篇 |
1994年 | 47篇 |
1993年 | 50篇 |
1992年 | 128篇 |
1991年 | 115篇 |
1990年 | 102篇 |
1989年 | 107篇 |
1988年 | 98篇 |
1987年 | 93篇 |
1986年 | 69篇 |
1985年 | 62篇 |
1984年 | 66篇 |
1983年 | 51篇 |
1982年 | 37篇 |
1981年 | 31篇 |
1979年 | 55篇 |
1978年 | 45篇 |
1977年 | 45篇 |
1976年 | 33篇 |
1973年 | 37篇 |
1972年 | 31篇 |
1971年 | 39篇 |
1967年 | 30篇 |
1966年 | 32篇 |
排序方式: 共有5698条查询结果,搜索用时 15 毫秒
81.
PC NG KW SO TF FOK MC YAM MY WONG W WONG 《Journal of paediatrics and child health》1997,33(4):324-328
Objectives: A prospective study comparing the efficiacy and side-effects of oral sulindac with intravenous indomethacin in clinically stable preterm infants (<1750 g) requiring non-invasive closure of haemodynamically significant patent ductus arteriosus.
Methodology: As maturity and birthweight are the two major determinants of ductal closure, infants were matched as closely as possible for these parameters. An eligible patient was first assigned to the sulindac group and a subsequent patient with similar gestational age (± 1 week) and birthweight (±100 g) to the previously recruited infant would automatically receive indomethacin. A total of eight infants were enrolled in each group.
Results: The ductus arteriosus was successfully closed in all eight infants receiving indomethacin, and in seven of eight infants receiving sulindac. No significant differences were found with regards to the ductal size between the two groups at diagnosis or on each of the consecutive days of treatment ( P >0.25). More renal adverse effects were encountered in the indomethacin group. Significant differences in changes from baseline value for urine output, plasma sodium, urea and creatinine concentrations were noted at 24, 48 and 72 h after commencement of treatment between the two groups ( P <0.05). All the parameters returned to normal or pre-treatment levels 48 h after stopping therapy. Unexpectedly, severe gastrointestinal complications were encountered in the sulindac group.
Conclusions: Sulindac is capable of promoting ductal constriction in clinically stable preterm infants without compromising the renal function. The spectrum of gastrointestinal complications observed in sulindac treated infants were similar to those described for indomethacin. The use of sulindac for ductal closure in the preterm infant should remain experimental. 相似文献
Methodology: As maturity and birthweight are the two major determinants of ductal closure, infants were matched as closely as possible for these parameters. An eligible patient was first assigned to the sulindac group and a subsequent patient with similar gestational age (± 1 week) and birthweight (±100 g) to the previously recruited infant would automatically receive indomethacin. A total of eight infants were enrolled in each group.
Results: The ductus arteriosus was successfully closed in all eight infants receiving indomethacin, and in seven of eight infants receiving sulindac. No significant differences were found with regards to the ductal size between the two groups at diagnosis or on each of the consecutive days of treatment ( P >0.25). More renal adverse effects were encountered in the indomethacin group. Significant differences in changes from baseline value for urine output, plasma sodium, urea and creatinine concentrations were noted at 24, 48 and 72 h after commencement of treatment between the two groups ( P <0.05). All the parameters returned to normal or pre-treatment levels 48 h after stopping therapy. Unexpectedly, severe gastrointestinal complications were encountered in the sulindac group.
Conclusions: Sulindac is capable of promoting ductal constriction in clinically stable preterm infants without compromising the renal function. The spectrum of gastrointestinal complications observed in sulindac treated infants were similar to those described for indomethacin. The use of sulindac for ductal closure in the preterm infant should remain experimental. 相似文献
82.
FJ Cowan JT Warner LM Lowes JP Riberio JW Gregory 《Archives of disease in childhood》1997,77(2):109-114
AIMS: To define outcome measures for auditing the clinical care of children and adolescents with insulin dependent diabetes mellitus (IDDM) and to assess the benefit of appointing a dedicated paediatric trained diabetes specialist nurse (PDSN). METHODS: Retrospective analysis of medical notes and hospital records. Glycaemic control, growth, weight gain, microvascular complications, school absence, and the proportion of children undergoing an annual clinical review and diabetes education session were assessed. The effect of the appointment of a PDSN on the frequency of hospital admission, length of inpatient stay, and outpatient attendance was evaluated. RESULTS: Children with IDDM were of normal height and grew well for three years after diagnosis, but grew suboptimally thereafter. Weight gain was above average every year after diagnosis. Glycaemic control was poor at all ages with only 16% of children having an acceptable glycated haemoglobin. Eighty five per cent of patients underwent a formal annual clinical review, of whom 16% had background retinopathy and 20% microalbuminuria in one or more samples. After appointing the PDSN the median length of hospital stay for newly diagnosed patients decreased from five days to one day, with 10 of 24 children not admitted. None of the latter was admitted during the next year. There was no evidence of the PDSN affecting the frequency of readmission or length of stay of children with established IDDM. Non-attendance at the outpatient clinic was reduced from a median of 19 to 10%. CONCLUSIONS: Outcome measures for evaluating the care of children with IDDM can be defined and evaluated. Specialist nursing support markedly reduces the length of hospital stay of newly diagnosed patients without sacrificing the quality of care. 相似文献
83.
Cha CH Lee FT Gurney JM Markhardt BK Warner TF Kelcz F Mahvi DM 《AJR. American journal of roentgenology》2000,175(3):705-711
OBJECTIVE: The objective of this study was to compare CT and sonography for monitoring radiofrequency (RF) lesions in porcine livers. SUBJECTS AND METHODS: RF lesions (n = 12) were created in three pig livers by applying 13 min of current to a multielectrode RF probe with a target temperature of 95 degrees C. Helical unenhanced CT and corresponding axial sonography were performed before ablation, at 2 min, 8 min, and immediately after ablation. Contrast-enhanced CT was performed after ablation. CT scans and sonograms were evaluated by blinded observers for conspicuity of the RF lesion, edge detection (visibility of liver-lesion interface), and artifacts. Hounsfield units were recorded at every time interval, and radiologic-pathologic correlation for lesion size and configuration was performed. RESULTS: Mean size of RF lesions was 3. 03 +/- 0.9 cm. On CT, RF lesions had consistently lower attenuation values than surrounding liver (22.2 H lower than liver at 8 min, p < 0.0001). Echogenicity was variable with sonography (hypoechoic = 59%, hyperechoic = 25%, isoechoic = 16%). Unenhanced CT significantly improved conspicuity, edge detection of RF lesions, and decreased artifacts compared with sonography (p < 0.05). Contrast-enhanced CT improved RF lesion detection, border discrimination, and artifacts compared with sonography (p < 0.05). Unenhanced CT had the best correlation to pathologic size (r = 0.74), followed by contrast-enhanced CT (r = 0.72) and sonography (r = 0.56). Contrast-enhanced CT best correlated with lesion shape, but slightly overestimated size because of areas of ischemia peripheral to the RF lesion. CONCLUSION: In this animal model, unenhanced CT was an effective way to monitor RF ablation compared with sonography because of increased lesion discrimination, reproducible decreased attenuation during ablation, and improved correlation to pathologic size. 相似文献
84.
85.
Gonadal hormones are important mediators of sexual and aggressive behavior in vertebrates. Recent evidence suggests that the peptide hormones arginine vasotocin (AVT) and its mammalian homologue arginine vasopressin (AVP) often critically mediate these gonadal hormone effects on behavior and have direct influences on behavioral variation. Behavioral differences between sexes, across reproductive states, and even among closely related species are correlated with differences in central AVT/AVP systems in many species. We report differences in hypothalamic AVT mRNA levels between distinct alternate male phenotypes and with female-to-male sex change in the bluehead wrasse (Thalassoma bifasciatum), a teleost fish. The aggressively dominant and strongly courting male phenotype has greater numbers of AVT mRNA producing cells in the magnocellular preoptic area of the hypothalamus than females. Levels of AVT mRNA within these cells in dominant males are also approximately three times female levels whereas the non-aggressive male phenotype has AVT mRNA levels approximately twice female levels. Behavioral sex change is very rapid in this species and is not dependent on the presence of gonads. Conversely, rapid increases in sexual and aggressive behavior during sex change are closely paralleled by approximate fourfold increases in hypothalamic AVT-mRNA levels. The behavioral plasticity shown by bluehead wrasses in response to social environment might be mediated in part by a neuropeptide, AVT, with changes in the gonads and gonadal hormones as the result rather than the cause of behavioral dominance. Copyright (R) 2000 S. Karger AG, Basel 相似文献
86.
A comparison of strain-related susceptibility in two murine recovery models of global cerebral ischemia 总被引:10,自引:0,他引:10
Wellons JC Sheng H Laskowitz DT Burkhard Mackensen G Pearlstein RD Warner DS 《Brain research》2000,868(1):481-21
Genetically engineered mice are increasingly important in stroke research. The strains on which these constructs are built are known to have inherent differential sensitivities to ischemic insults. This has been largely attributed to differences in vascular anatomy. This study compared the outcome from forebrain ischemia in two common murine background strains using two different types of ischemic insult. C57Bl/6 and SV129 mice were subjected to two vessel (bilateral carotid) occlusion (2VO) or 2VO plus systemic hypotension (2VO+Hypo; mean arterial pressure=30+/-2 mmHg) for 10-20 min. Ventilation and pericranial temperature were controlled. Cerebral blood flow (CBF) was determined by 14C-iodoantipyrine autoradiography. Histologic damage in forebrain structures was measured 3 days post-ischemia. During 2VO+Hypo, the EEG became isoelectric in all animals. During 2VO alone, EEG isoelectricity occurred in 73% of C57Bl/6 and 50% of SV129 mice. Forebrain CBF was reduced to a similar extent in both strains. Greater CBF variability was seen with 2VO alone versus 2VO+Hypo. CBF was less in the 2VO+Hypo model. SV129 mice had wider posterior communicating but smaller basilar artery diameters. With or without hypotension, SV129 mice had markedly less severe histologic damage than C57Bl/6 mice. A time-dependent increase in histologic damage was demonstrated in the 2VO+Hypo model but not with 2VO alone. The 2VO and 2VO+Hypo models produced similar magnitudes of histologic injury in C57Bl/6 mice subjected to 10-min ischemia. SV129 mice were resistant to ischemia in either model. The 2VO+Hypo model produced a more uniform severity of ischemia as defined by CBF and EEG examination. Despite this, the murine strain had a substantially greater impact on histologic outcome than did cerebrovascular anatomy or the type of model used to produce the ischemic insult. 相似文献
87.
Kinney MA Warner ME vanHeerden JA Horlocker TT Young WF Schroeder DR Maxson PM Warner MA 《Anesthesia and analgesia》2000,91(5):1118-1123
Pheochromocytomas and paragangliomas are often surgically curable. However, resection of these tumors can be life threatening. We undertook this study to determine the frequency of, and risk factors for, perioperative complications in patients undergoing resection of pheochromocytoma or paraganglioma. We retrospectively reviewed the medical records of patients during 1983-1996 who underwent surgical resection of catecholamine-secreting pheochromocytoma or paraganglioma. Preoperative risk factors, adverse intraoperative events, and complications occurring in the 30 days after operation were recorded. Blood pressures were collected from manual records. The ranked sum test and Fisher's exact test were used for analyses. Adverse perioperative events or complications occurred in 45 of 143 patients (31.5%; exact 95% confidence interval, 24.0% to 39.8%). Of these 45 patients, 41 experienced one or more adverse intraoperative events. The most common adverse event was sustained hypertension (36 patients). There were no perioperative deaths, myocardial infarctions, or cerebrovascular events. Preoperative factors univariately associated with adverse perioperative events included larger tumor size (P: = 0.007), prolonged duration of anesthesia (P: = 0.015), and increased levels of preoperative urinary catecholamines and catecholamine metabolites: vanillylmandelic acid (P: = 0.019), metanephrines (P: = 0.004), norepinephrine (P: = 0. 014), and epinephrine (P: = 0.004). Despite premedication of most patients with phenoxybenzamine and a beta-adrenergic blocker, varying degrees of intraoperative hemodynamic lability occurred. Implications: Few patients who had pheochromocytoma or paraganglioma resection experienced significant perioperative morbidity and none died in the largest retrospective study on this topic to date. This study confirms the very good perioperative outcomes demonstrated in smaller studies on this high-risk population, and identifies several risk factors for adverse outcomes. 相似文献
88.
Nausea or vomiting occurs frequently after craniotomy. Because of the need for frequent postoperative neurological assessment, an effective antiemetic with minimal sedative side effects is needed. Therefore, we compared ondansetron to droperidol in a randomized, double-blinded, placebo-controlled study. A total of 60 adults requiring elective supratentorial craniotomy received standardized IV anesthesia with 4 mg of ondansetron, 0.625 mg of droperidol, or placebo at skin closure. The incidence of postoperative nausea, emesis, pain and sedation scores, and rescue antiemetic use were recorded at 0, 0.5, 1, 4, 8, 12, 24, and 48 h. All groups were demographically similar. Differences existed for cumulative 8, 12, and 24 h incidences of nausea (24 h, P = 0.03) and emesis (24 h, P = 0.04). Within 4 h, when maximal effect could be expected from treatment, 20% of the ondansetron group, 25% of the droperidol group and 50% of the placebo group received rescue antiemetic (P = 0.12). No differences in pain (P = 0.82) or sedation (P = 0.74) scores were detected. Both ondansetron and droperidol prevent nausea; however, only droperidol reduces emesis after supratentorial craniotomy. The dose of droperidol used was not more sedating than ondansetron. Sustained reduction in nausea and emesis over 24 h indicates a preemptive benefit of prophylactic antiemetic in this surgical population. Implications: Nausea and vomiting after brain surgery are particularly troubling, because effective treatment may cause sedation, making postoperative neurological assessment difficult. Our study shows that both ondansetron and droperidol are effective in reducing nausea, and that droperidol is particularly effective in reducing vomiting. Neither drug caused more sedation than placebo. 相似文献
89.
90.
Cole BJ L'Insalata J Irrgang J Warner JJ 《The Journal of bone and joint surgery. American volume》2000,(8):1108-1114
BACKGROUND: Sixty-three consecutive patients with recurrent traumatic anterior shoulder instability underwent operative repair. The decision to select either arthroscopic Bankart repair or open capsular shift was based on the findings of an examination under anesthesia and the findings at the time of arthroscopy. Thirty-nine patients with only anterior translation on examination under anesthesia and a discrete Bankart lesion underwent arthroscopic Bankart repair with use of absorbable transfixing implants. Twenty-four patients with inferior translation in addition to anterior translation on examination under anesthesia and capsular laxity or injury on arthroscopy underwent an open capsular shift. METHODS: Treatment outcomes for each group were determined according to the scoring systems of Rowe et al., the American Shoulder and Elbow Surgeons, and the Short Form-36. Failure was defined as recurrence of dislocation or subluxation or the finding of apprehension. Fifty-nine (94 percent) of the sixty-three patients were examined and filled out a questionnaire at a mean of fifty-four months (range, twenty-seven to seventy-two months) following surgery. RESULTS: There were no significant differences between the two groups with regard to the prevalence of failure or any of the other measured parameters of outcome. An unsatisfactory outcome occurred after nine (24 percent) of thirty-seven arthroscopic repairs and after four (18 percent) of twenty-two open reconstructions. All cases of recurrent instability resulted from a reinjury in a contact sport or a fall less than two years postoperatively. The treatment groups did not differ with regard to patient age, hand dominance, mechanism of initial injury, duration of follow-up, or delay until surgery. Measured losses of motion were minimal and, with the exception of forward elevation, slightly more of which was lost after the open capsular shifts (p = 0.05), did not differ between the two forms of treatment. Approximately 75 percent of the patients in each group returned to their favorite recreational sports with no or mild limitations. As rated by the patients, the result was good or excellent after thirty-one (84 percent) of the arthroscopic procedures and after twenty (91 percent) of the open procedures. CONCLUSIONS: Arthroscopic and open repair techniques for the treatment of recurrent traumatic shoulder instability yield comparable results if the procedure is selected on the basis of the pathological findings at the time of surgery. 相似文献