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51.
Magnetic resonance imaging of pulmonary parenchyma perfusion using pulsed arterial spin labeling (ASL) techniques is presented. ASL uses magnetically labeled water as an endogenous, freely diffusible tracer. Presented are comparative results of ASL methods called Flow sensitive Alternating Inversion Recovery (FAIR), and FAIR with an Extra Radiofrequency pulse (FAIRER). Six healthy human volunteers were imaged. Perfusion-weighted images at different time delays, TI, were calculated from the subtraction of the control and tag images, which were acquired within a single breathhold. Detailed pulmonary structures can be visualized with negligible cardiac or respiratory motion artifacts. Different patterns of signal enhancement between the pulmonary vessels and parenchyma are shown in the perfusion images acquired at different TIs.  相似文献   
52.

Purpose

To evaluate the effect of image guided radiotherapy with stereotactic ultrasound BAT (B-mode acquisition and targeting system) on rectal toxicity in conformal radiotherapy of prostate cancer.

Patients and Methods

42 sequential patients with prostate cancer undergoing radiotherapy before and after the introduction of BAT were included. Planning computed tomography (CT) was performed with empty rectum and moderately filled bladder. The planning target volume (PTV) included the prostate and seminal vesicles with a safety margin of 1.5 cm in anterior and lateral direction. In posterior direction the anterior 1/3 of the rectum circumference were included. Total dose was 66 Gy and a boost of 4 Gy excluding the seminal vesicles. 22 patients (BAT group) were treated with daily stereotactic ultrasound positioning, for the other 20 patients (NoBAT group) an EPID (electronic portal imaging device) was performed once a week. Acute and late genito-urinary (GU) and rectal toxicity and PSA values were evaluated after 1.5, 3, 6, 9 and 12 months. The total median follow up of toxicity was 3 years in the BAT group and 4 years in the NoBAT group.

Results

In the NoBAT group significant more rectal toxicity occurred, while in GU toxicity no difference was seen. Two patients in the NoBAT group showed late rectal toxicity grade 3, no toxicity > grade 2 occurred in the BAT group. There was no significant difference in PSA reduction between the groups.

Conclusion

Without BAT significant more acute and a trend to more late rectal toxicity was found. With regard to dose escalation this aspect is currently evaluated with a larger number of patients using intensity-modulated radiotherapy (IMRT).  相似文献   
53.
This study investigated the association between micronutrient intake and breast cancer risk in South Korean adult women. This association was stratified according to body mass index (BMI) categories. Data from the Korean Genome and Epidemiology Study (KoGES) and the Health Examinee Study were analyzed. Altogether, 63,337 individuals (aged ≥40 years) completed the baseline and first follow-up surveys; 40,432 women without a history of cancer at baseline were included in this study. The association between micronutrient intake and breast cancer was determined by estimating the hazard ratio (HR) and 95% confidence interval (CI) using the Cox proportional hazard regression model. A stratified analysis by BMI (<25 kg/m2 and ≥25 kg/m2) was performed. The an analysis of 15 micronutrients and breast cancer risk revealed that none of the micronutrients were associated with breast cancer risk after adjusting for covariates. In obese women, the risk of breast cancer was significantly reduced in the group that consumed vitamin C more than the recommended level (HR = 0.54, 95% CI: 0.31–0.93) and vitamin B6 levels above the recommended level (HR = 0.48, 95% CI: 0.25–0.89). In obese women, exceeding the recommended daily intake levels of vitamin C and vitamin B6 was associated with a lower risk of breast cancer. However, other micronutrients were not associated with breast cancer risk in these women.  相似文献   
54.
Recombinant severe acute respiratory syndrome (SARS) nucleocapsid and spike protein-based immunoglobulin G immunoassays were developed and evaluated. Our assays demonstrated high sensitivity and specificity to the SARS coronavirus in sera collected from patients as late as 2 years postonset of symptoms. These assays will be useful not only for routine SARS coronavirus diagnostics but also for epidemiological and antibody kinetic studies.  相似文献   
55.

Introduction

The frequency of colorectal cancer (CRC) is dependent on sex and age. The illness more often affects men than women, and a considerable increase in morbidity is noted after 65 years of age. The aim of the study was to assess the influence of various risk factors on CRC morbidity, statistical data from countries varied in cultural, socioeconomic and biological terms need to be studied. Poland and Japan can serve as examples of such contrasts.

Material and methods

The basis for the analysis of CRC morbidity was statistical data from Poland and Japan gathered in the period 1999–2006. They were expressed in absolute numbers and were related to the total morbidity, as well as morbidity according to sex and age.

Results

In the years 1999–2006, the total morbidity in Japan was on average 2.3 times higher than in Poland. The value was 2.5 times higher among men and 2.1 times among women when compared to Poland. In both countries morbidity is closely related to age and it reaches a peak between 65 and 74 years of age. Although the change in morbidity over the period was the same for Poland and Japan, there are considerable differences concerning the sex of the patients.

Conclusions

There is a substantial increase in CRC morbidity in both countries, especially among elderly people, which may point to the predominant influence of environmental factors and population aging in both countries. The much higher increase in morbidity among Polish men when compared to Polish women, not observed in the Japanese population, requires further study.  相似文献   
56.
目的:探讨翻转课堂教学模式在医学机能学实验教学中的应用效果。方法:对实验组与对照组学生分别采用翻转课堂教学模式和传统教学模式进行教学,应用期末考试成绩和问卷调查结合的形式,进行教学效果评价。结果:实验组的教学效果明显优于对照组。结论:翻转教学模式在医学机能学实验教学中具有明显的应用优势,更能提高其教学效果。  相似文献   
57.
Purpose: Orthodontic tooth movement occurs during the bone remodeling induced by therapeutic mechanical strain. It is important to investigate the relation between the strength of mechanical stress and bone formation activity. The aim of this study was to determine the effect of high-magnitude mechanical strain on bone formation in detail.

Materials and methods: Osteoblast-like cells isolated from fetal rat calvariae were loaded with 18% cyclic tension force (TF) for 48?h. To phenotypically investigate the effect of TF, we measured the number and the size of bone nodules stained by von Kossa technique on day 21 after cell seeding and determined the calcium content of bone nodules on day 14. Furthermore, we examined the gene expression of BMP-2, Runx2 and Msx2, which are important factors for bone nodule formation, on days 1, 4 and 7 after TF loading.

Results: The maximum bone nodule size in the control group was 1620 and 719?μm in the TF group. Furthermore, the mean number of bone nodules sized over 360?μm in the TF group was significantly decreased compared to the control group. The calcium content was also significantly decreased to 42% by TF loading. The mRNA expression of BMP-2, Runx2 and Msx2 was decreased 1 and 4 days after TF loading.

Conclusion: The differentiation of bone forming progenitor cells into bone nodule forming cells was inhibited by TF due to the decreased expression of bone formation related factors such as BMP-2, Runx2 and Msx2.  相似文献   
58.
OBJECTIVES/HYPOTHESIS: Cochlear implantation is an established method of auditory rehabilitation for severely and profoundly hearing impaired individuals. Although numerous studies have examined communication outcomes in pediatric cochlear implant (CI) recipients, data concerning the benefits of cochlear implantation in children who speak Mandarin Chinese are lacking. This study examined communication outcomes in 29 Mandarin-speaking children implanted at Chung Gung Memorial Hospital. DESIGN: A prospective between-groups design was used to compare communication outcomes as a function of age at time of implantation. METHODS: Children in the Younger group were implanted before 3 years of age, whereas children in the Older group were implanted after 3 years of age. Outcome measures assessed auditory thresholds, speech perception, speech intelligibility, receptive and expressive language skills, communication barriers, and communication mode. Correlation analysis was used to examine the relationship between communication outcome and age at implantation. RESULTS: Children in the Younger group demonstrated a significant level of difference on Mandarin vowels, consonants, tones, and open-set speech perception compared with the children in the Older group. Between-group differences were also shown on receptive and expressive language skills. But, no significant differences were noted on speech intelligibility or in self-ratings of communication barriers. A larger proportion of children in the Younger group used oral communication and were educated in mainstream classrooms. Communication mode change of the Younger group reached a significant level after cochlear implant. Speech perception performance was negatively correlated with age at implantation as well as chronological age. Mandarin-speaking children can obtain substantial communication benefits from cochlear implantation, with earlier implantation yielding superior results.  相似文献   
59.
60.
Ultrastructure and chemical analysis of Campylobacter pylori flagella.   总被引:13,自引:2,他引:13  
Flagella of Campylobacter pylori were analyzed by electron microscopy and purified, and the molecular weight of the flagellin was determined. Isolation of flagella was performed by mechanical shearing from the cell surface, sucrose density gradient centrifugation, and Sepharose CL-4B gel chromatography. The flagella of C. pylori differ from those of other Campylobacter species and of most other bacteria by the presence of a flagellar sheath. The sheath narrows at the end and is linked to a club-shaped terminal structure. The molecular weight of C. pylori flagellin was 51,000.  相似文献   
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