全文获取类型
收费全文 | 3554篇 |
免费 | 245篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 45篇 |
儿科学 | 92篇 |
妇产科学 | 83篇 |
基础医学 | 500篇 |
口腔科学 | 133篇 |
临床医学 | 339篇 |
内科学 | 670篇 |
皮肤病学 | 92篇 |
神经病学 | 406篇 |
特种医学 | 72篇 |
外科学 | 387篇 |
综合类 | 20篇 |
预防医学 | 451篇 |
眼科学 | 73篇 |
药学 | 216篇 |
中国医学 | 22篇 |
肿瘤学 | 210篇 |
出版年
2024年 | 11篇 |
2023年 | 86篇 |
2022年 | 140篇 |
2021年 | 250篇 |
2020年 | 152篇 |
2019年 | 158篇 |
2018年 | 200篇 |
2017年 | 121篇 |
2016年 | 135篇 |
2015年 | 121篇 |
2014年 | 161篇 |
2013年 | 189篇 |
2012年 | 287篇 |
2011年 | 315篇 |
2010年 | 172篇 |
2009年 | 138篇 |
2008年 | 183篇 |
2007年 | 180篇 |
2006年 | 167篇 |
2005年 | 143篇 |
2004年 | 134篇 |
2003年 | 92篇 |
2002年 | 80篇 |
2001年 | 22篇 |
2000年 | 24篇 |
1999年 | 16篇 |
1998年 | 13篇 |
1997年 | 13篇 |
1996年 | 12篇 |
1995年 | 14篇 |
1994年 | 5篇 |
1993年 | 10篇 |
1992年 | 3篇 |
1991年 | 9篇 |
1990年 | 10篇 |
1989年 | 8篇 |
1988年 | 5篇 |
1987年 | 8篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1982年 | 4篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1937年 | 1篇 |
1928年 | 1篇 |
排序方式: 共有3811条查询结果,搜索用时 31 毫秒
31.
Introduction The purpose of this study was to examine the normal pituitary gland in male subjects with ultrashort echo time (TE) pulse
sequences, describe its appearance and measure its signal intensity before and after contrast enhancement.
Methods Eleven male volunteers (mean age 57.1 years; range 36–81 years) were examined with a fat-suppressed ultrashort TE (= 0.08 ms)
pulse sequence. The studies were repeated after the administration of intravenous gadodiamide. The MR scans were examined
for gland morphology and signal intensity before and after enhancement. Endocrinological evaluation included baseline pituitary
function tests and a glucagon stimulatory test to assess pituitary cortisol and growth hormone reserve.
Results High signal intensity was observed in the anterior pituitary relative to the brain in nine of the 11 subjects. These regions
involved the whole of the anterior pituitary in three subjects, were localised to one side in two examples and were seen inferiorly
in three subjects. Signal intensities relative to the brain increased with age, with a peak around the sixth or seventh decade
and decreasing thereafter. Overall, the pituitary function tests were considered to be within normal limits and did not correlate
with pituitary gland signal intensity.
Conclusion The anterior pituitary shows increased signal intensity in normal subjects when examined with T1-weighted ultrashort TE pulse sequences. The cause of this increased intensity is unknown, but fibrosis and iron deposition
are possible candidates. The variation in signal intensity with age followed the temporal pattern of iron content observed
at post mortem. No relationship with endocrine status was observed. 相似文献
32.
Two-step surgery for synchronous bilobar liver metastases from digestive endocrine tumors: a safe approach for radical resection 总被引:1,自引:0,他引:1
Kianmanesh R Sauvanet A Hentic O Couvelard A Lévy P Vilgrain V Ruszniewski P Belghiti J 《Annals of surgery》2008,247(4):659-665
OBJECTIVE: We describe the early and distant results of a 2-step surgical strategy that enables complete resection in selected patients with primary digestive endocrine tumors (DET) and synchronous bilobar liver metastases (LM). BACKGROUND: Frequent synchronous and bilobar liver involvement limits indications of surgery in LM from DET. STUDY DESIGN: From 1996 to 2004, of 41 patients with synchronous bilobar LM from DET, 23 (56%) were selected for 2-step surgery. The first step included resection of the primary tumor and limited (nonanatomic) resection of left LM (segments 1-4) associated with a right portal vein ligation. After 8 weeks, following hypertrophy of the cleared left liver, a right or extended right hepatectomy was planned. RESULTS: At the first step, all primary tumors (bowel = 12, distal pancreas = 10, rectal = 1) were resected and LM were resected in 20 patients (87%). One patient did not have second-step due to tumor progression. The second step (n = 19; 83%) was performed after a median interval of 8 weeks (range, 6-13) and a 54 +/- 21% mean left liver hypertrophy rate. Postoperatively, 4 (17%) and 4 (21%) patients developed nonlethal complications and the median hospital stay was 11 (range, 7-26) and 13 (range, 9-17) days after the first and the second step, respectively. The median number of resected LM was 4 (range, 1-9) and 7 (range, 4-17), respectively. With a median follow-up of 64 months (range, 6-122), of the 19 patients who had complete 2-step surgery, all except one are alive. The 2-, 5-, and 8-year Kaplan-Meier overall and disease-free survival rates were 94%, 94%, 79% and 85%, and 50% and 26%, respectively. CONCLUSIONS: This 2-step surgery approach enables complete resection with no mortality, acceptable morbidity, and good long-term survival in selected patients with synchronous bilobar LM from DET. 相似文献
33.
34.
Palazuelos-Genis T Mosti M Sánchez-Leenheer S Hernández R Garduño O Herrera MF 《Obesity surgery》2008,18(1):1-4
Background Weight loss in patients undergoing gastric bypass should be primarily from fat mass (FM), minimizing the fat-free mass (FFM)
loss. The aim of this study was to analyze changes in body weight and body composition during the first postoperative year
in 50 morbidly obese patients undergoing a Laparoscopic Roux-en-Y gastric bypass (LRYGBP) at the Obesity Clinic of the ABC
Medical Center.
Methods Patient’s weight and body composition were obtained before surgery and 1 year later using bioelectrical impedance analysis
(BIA). Weight, FM, FMM, and total body water (TBW) were measured before and 1 year after surgery. Changes in body composition
were particularly analyzed.
Results There were 29 females and 21 males with mean age of 41 ± 12 years. Mean BMI before surgery and 1 year after surgery was 44.4 ± 7.4 kg/m2 and 28.3±4.3 kg/m2, respectively. The percentage of excess body weight loss at the 1-year period was 86% for women and 79.6% for men. The percentage
of FM before surgery was 47.7 ± 5.1, and 1 year later it was 28.8 ± 8. The percentage of FFM was 66.5 ± 16.5 before surgery
and 58.3 ± 13 at 1 year.
Conclusions There is a significant weight loss in patients undergoing LRYGBP. Weight loss mainly occurs as a consequence of reduction
in the FM with less impact on the FFM. 相似文献
35.
Josinaldo Jarbas da Silva David George Behm Willy Andrade Gomes Fernando Henrique Domingues de Oliveira Silva Enrico Gori Soares érica Paes Serpa Guanis de Barros Vilela Junior Charles Ricardo Lopes Paulo Henrique Marchetti 《Journal of Sports Science and Medicine》2015,14(2):315-321
The aim of this study was to evaluate the acute effects of unilateral ankle plantar flexors static-stretching (SS) on the passive range of movement (ROM) of the stretched limb, surface electromyography (sEMG) and single-leg bounce drop jump (SBDJ) performance measures of the ipsilateral stretched and contralateral non-stretched lower limbs. Seventeen young men (24 ± 5 years) performed SBDJ before and after (stretched limb: immediately post-stretch, 10 and 20 minutes and non-stretched limb: immediately post-stretch) unilateral ankle plantar flexor SS (6 sets of 45s/15s, 70-90% point of discomfort). SBDJ performance measures included jump height, impulse, time to reach peak force, contact time as well as the sEMG integral (IEMG) and pre-activation (IEMGpre-activation) of the gastrocnemius lateralis. Ankle dorsiflexion passive ROM increased in the stretched limb after the SS (pre-test: 21 ± 4° and post-test: 26.5 ± 5°, p < 0.001). Post-stretching decreases were observed with peak force (p = 0.029), IEMG (P<0.001), and IEMGpre-activation (p = 0.015) in the stretched limb; as well as impulse (p = 0.03), and jump height (p = 0.032) in the non-stretched limb. In conclusion, SS effectively increased passive ankle ROM of the stretched limb, and transiently (less than 10 minutes) decreased muscle peak force and pre-activation. The decrease of jump height and impulse for the non-stretched limb suggests a SS-induced central nervous system inhibitory effect.
Key points
- When considering whether or not to SS prior to athletic activities, one must consider the potential positive effects of increased ankle dorsiflexion motion with the potential deleterious effects of power and muscle activity during a simple jumping task or as part of the rehabilitation process.
- Since decreased jump performance measures can persist for 10 minutes in the stretched leg, the timing of SS prior to performance must be taken into consideration.
- Athletes, fitness enthusiasts and therapists should also keep in mind that SS one limb has generalized effects upon contralateral limbs as well.
36.
Infiltration of natural killer (NK) cells into solid organ allografts is observed in clinical and experimental transplantation. Studies suggest a role for NK cells in acute and chronic rejection of solid organ allografts; however, the effects of immunosuppressive agents on NK cells are not clearly established. Rat NK cell lines were analyzed for proliferation and cytotoxicity in the presence of cyclosporine, FK506, or rapamycin. Lewis recipients of DA liver allografts received immunosuppressive agents after transplantation. NK cells demonstrated robust function both in the absence and presence of cyclosporine and FK506. In contrast, rapamycin significantly inhibited proliferation and cytotoxicity of NK cells. NK cell numbers remained stable in graft recipients treated with cyclosporine and FK506, whereas there was a significant decrease in NK cells in rapamycin-treated recipients. These data indicate that immunosuppressive drugs have differential effects on NK cell function that may impact the immune response of transplant recipients. 相似文献
37.
38.
Berti-Couto Sde A Couto-Souza PH Jacobs R Nackaerts O Rubira-Bullen IR Westphalen FH Moysés SJ Ignácio SA Costa MB Tolazzi AL 《Journal of applied oral science : revista FOB》2012,20(2):157-161
Objective
The aim of this study was to evaluate the effectiveness of clinical criteria for the diagnosis of hyposalivation in hospitalized patients.Material and Methods
A clinical study was carried out on 145 subjects (48 males; 97 females; aged 20 to 90 years). Each subject was clinically examined, in the morning and in the afternoon, along 1 day. A focused anamnesis allowed identifying symptoms of hyposalivation, like xerostomia complaints (considered as a reference symptom), chewing difficulty, dysphagia and increased frequency of liquid intake. Afterwards, dryness of the mucosa of the cheecks and floor of the mouth, as well as salivary secretion during parotid gland stimulation were assessed during oral examination.Results
Results obtained with Chi-square tests showed that 71 patients (48.9%) presented xerostomia complaints, with a significant correlation with all hyposalivation symptoms (p<0.05). Furthermore, xerostomia was also significantly correlated with all data obtained during oral examination in both periods of evaluation (p<0.05).Conclusion
Clinical diagnosis of hyposalivation in hospitalized patients is feasible and can provide an immediate and appropriate therapy avoiding further problems and improving their quality of life. 相似文献39.
Ana Patrícia Domingues Etelvina Fonseca Adriana Belo Paulo Moura 《The journal of maternal-fetal & neonatal medicine》2015,28(9):1108-1111
Objective: To evaluate the influence of the local prenatal surveillance of twin pregnancies in the obstetrical results.Methods: A prospective cohort study of multiple pregnancies delivered over a period of 16 years in a tertiary centre was conducted. In this study 861 twin pregnancies were included. They were compared for obstetric complications, gestational age at delivery, mode of delivery and birthweight, according to the place of the surveillance.Results: Of the 861 cases examined, the following obstetric complications were significantly different: metrorrhagia (p?=?0.039), infections (p?0.001), HELLP (p?=?0.007), PROMPT (p?0.001) and fetal death (p?=?0.024). The mode of delivery was similar but occurred mostly ≤32 weeks (p?0.001), the birthweight was mostly <2000?g and occurred more NICU admission (p?0.001) when surveillance was outside the MPC-MDM.Conclusion: Our results demonstrate the crucial importance of prenatal surveillance be carried in a differentiated referral centers with specific/strict protocols or the urgent implementation of same protocols in all other places of surveillance, since this straight surveillance greatly reduces the occurrence of prenatal complications, mainly PROMPT, PTD. 相似文献
40.