全文获取类型
收费全文 | 183592篇 |
免费 | 1271篇 |
国内免费 | 84篇 |
专业分类
耳鼻咽喉 | 1173篇 |
儿科学 | 6753篇 |
妇产科学 | 3064篇 |
基础医学 | 17648篇 |
口腔科学 | 1730篇 |
临床医学 | 12840篇 |
内科学 | 33034篇 |
皮肤病学 | 720篇 |
神经病学 | 17156篇 |
特种医学 | 9148篇 |
外科学 | 30196篇 |
综合类 | 2342篇 |
预防医学 | 18214篇 |
眼科学 | 2856篇 |
药学 | 10142篇 |
中国医学 | 665篇 |
肿瘤学 | 17266篇 |
出版年
2023年 | 44篇 |
2022年 | 98篇 |
2021年 | 229篇 |
2020年 | 89篇 |
2019年 | 135篇 |
2018年 | 22052篇 |
2017年 | 17467篇 |
2016年 | 19648篇 |
2015年 | 1078篇 |
2014年 | 997篇 |
2013年 | 1056篇 |
2012年 | 7365篇 |
2011年 | 21452篇 |
2010年 | 19104篇 |
2009年 | 11714篇 |
2008年 | 19906篇 |
2007年 | 22140篇 |
2006年 | 1038篇 |
2005年 | 2605篇 |
2004年 | 3787篇 |
2003年 | 4732篇 |
2002年 | 2912篇 |
2001年 | 454篇 |
2000年 | 590篇 |
1999年 | 360篇 |
1998年 | 334篇 |
1997年 | 314篇 |
1996年 | 197篇 |
1995年 | 186篇 |
1994年 | 197篇 |
1993年 | 140篇 |
1992年 | 172篇 |
1991年 | 232篇 |
1990年 | 236篇 |
1989年 | 198篇 |
1988年 | 178篇 |
1987年 | 137篇 |
1986年 | 125篇 |
1985年 | 143篇 |
1984年 | 90篇 |
1983年 | 84篇 |
1982年 | 62篇 |
1980年 | 82篇 |
1979年 | 47篇 |
1978年 | 44篇 |
1970年 | 39篇 |
1969年 | 46篇 |
1938年 | 60篇 |
1932年 | 56篇 |
1930年 | 46篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
981.
Background and objectives In breast cancer, the expression pattern of CXCR4 may be correlated with the degree of axillary lymph node involvement. The
aim of this study was to evaluate the contributing factors that contribute to the correlation between CXCR4 expression and
axillary lymph node metastasis in breast cancer.
Methods Between August 1997 and August 2002, sections of paraffin-embedded tissue were obtained from 107 patients who received optimal
treatment for breast cancer. The expression of CXCR4 was evaluated by immunohistochemical staining.
Results A significant correlation was found in the expression of nuclear CXCR4 and lymph node metastasis (P = 0.03). We found a significant correlation between a high nuclear expression of CXCR4 and axillary lymphatic metastasis
in estrogen and progesterone receptor negative breast cancer (P = 0.01 and P = 0.01). There was a significant correlation between the high expression of nuclear CXCR4 and axillary lymphatic metastasis
in comparisons between positive estrogen and/or progesterone receptor expression and negative expression (P = 0.02).
Conclusions Our results showed that high expression of nuclear CXCR4 was significantly correlated with lymph node metastasis in breast
cancer. The high expression of nuclear CXCR4 in hormone receptor negative breast cancer was associated with a high possibility
of lymph node metastasis. 相似文献
982.
The authors report their experience on one patient with osteoblatoma of the odontoid process of the axis with secondary aneurysmal
bone cyst. According to their knowledge, this is the first case, reported in the literature, of this kind of lesion in that
particular anatomical region. Because of the rarity of this lesion, it was difficult to have a certain preoperative diagnosis.
Therefore, the patient underwent a biopsy via a transoral route. The biopsy was performed over the noncalcified component
of the lesion. The intraoperative histological examination showed the benign nature of the lesion. Thereafter, the lesion
was totally removed, succeeding in preserving the remaining part of the odontoid process and the anterior arch of C1. In the
follow-up, there was no evidence of cranio-vertebral instability. The histological examination revealed an osteoblastoma of
the odontoid process of the axis with a secondary aneurysmal bone cyst. To the best of our knowledge, this is the first case
reported in the literature. 相似文献
983.
Bas P. L. Wijnhoven Carolyn J. Lally John J. Kelly Jennifer C. Myers David I. Watson 《Journal of gastrointestinal surgery》2008,12(3):510-517
Introduction It is claimed that a substantial number of patients who undergo antireflux surgery use antireflux medication postoperatively.
This study was aimed to determine the prevalence and underlying reasons for antireflux medication usage in patients after
surgery.
Materials and Methods A questionnaire on the usage of antireflux medication was sent to 1,008 patients identified from a prospective database of
patients who had undergone a laparoscopic antireflux procedure.
Results A total of 844 patients (84%) returned the questionnaire. Mean follow-up was 5.9 years after surgery. A single or combination
of medications was being taken by 312 patients (37%): 82% proton pump inhibitors, 9% H2-blockers and 34% antacids. Fifty-two patients (17%) had never stopped taking medication, whereas 260 patients (83%) restarted
medication at a mean of 2.5 years after surgery. Return of the same (31%) or different (49%) symptoms were the commonest reasons
for taking medication, whereas 20% were asymptomatic or had other reasons for medication use. Postoperative 24-hour pH studies
were abnormal in 16/61 patients (26%) on medication and in 5/78 patients (6%) not taking medication.
Conclusions Antireflux medication is frequently taken by many patients for various symptoms after antireflux surgery. Symptomatic patients
should be properly investigated before antireflux medications are prescribed. 相似文献
984.
Background
The number of patients desiring reconstructive surgery after a huge weight loss achieved with gastric banding is increasing. This study was undertaken to determine whether plastic surgical removal of an overlap flap has a psychosocial effect on patients.Methods
Thirty-women and four men who underwent overlap flap surgery were interviewed 1 day before, and again 3 and approximately 12 months after the procedure using a series of instruments: Strauss and Appelt’s Questionnaire for assessing one’s body, the Body Perception Questionnaire by Paulus, the questionnaire for satisfaction of life by Fahrenberg, Myrtek, Schumacher, and Brähler, the Hospital Anxiety and Depression Scale (German version) by Herrmann, Buss, and Snaith, and the authors’ general questionnaire after surgery. The same clinical parameters were also investigated in a control group of persons who did not undergo plastic surgery. Comparisons were made before and after surgery between and in both groups.Results
In contrast to the control group, surgical patients reported a highly significant increase in self-confidence and the feeling of being attractive (p?≤?0.001); 75% of the surgical patients stated that their expectations were met by the plastic surgical intervention.Conclusion
Plastic surgery after weight loss improves body image and subjective quality of life. These results will influence the indication for a reconstructive operation in future.985.
Magnesium has neuroprotective and antivasospastic properties in the presence of subarachnoid hemorrhage (SAH). The present
study investigated the effect of intracisternal administration of magnesium on cerebral vasospasm in the experimental SAH
rat model. The rat double-SAH model (0.2 mL autologous blood injected twice into the cisterna magna) was used. Normal saline
(SAH group, N = 8) or 10 mmol/L magnesium sulfate in normal saline (SAH + MG group, N = 8) was infused into the cisterna magna at 1.5 μL/min for 30 min on day 5. Control rats without SAH also received intracisternal
infusion of normal saline (control group, N = 6). Local cerebral blood flow (CBF) at 24 locations and the weighted average were quantitatively measured by the autoradiographic
technique using [14C]iodoantipyrine during infusion. The weighted average CBF was significantly reduced (P < 0.01, Student’s t-test) in the SAH group (0.78 ± 0.16 mL g−1 min−1) compared to the control group (1.0 ± 0.15 mL g−1 min−1) and was significantly improved (P < 0.01, Student’s t-test) in the SAH + MG group (0.98 ± 0.18 mL g−1 min−1). Local CBF was significantly reduced (P < 0.05, unpaired t test) in 16 locations in the SAH group and significantly improved (P < 0.05, unpaired t test) in 12 locations in the SAH + MG group. Intracisternal infusion of magnesium sulfate significantly improved reduced
CBF induced by experimental SAH in the rat. 相似文献
986.
We report the case of a ball-valve gastric tumor associated with anomalous junction of the pancreatico-biliary ductal system
(AJPBDS) and a right-sided round ligament, misdiagnosed preoperatively as advanced gastric cancer with pancreatic head invasion.
A 72-year-old woman presented with chest pain, but laboratory data showed only anemia. Gastroscopy revealed a bleeding polypoid
gastric tumor in the anterior wall of the stomach, herniating into the duodenum (ball-valve syndrome), and a Bormann type-2
tumor in the posterior wall. Ultrasonography showed gallbladder stones, dilatation of the intrahepatic bile duct and pancreatic
duct, and a left-sided gallbladder (attributed to a right-sided round ligament with anomalous branches of the portal veins).
Laparotomy revealed that the gastric tumors were not advanced cancer invading the pancreatic head. Intraoperative cholangiography
showed an AJPBDS, causing dilatation of the intrahepatic bile duct and pancreatic duct. We performed distal gastrectomy and
cholecystectomy without biliary diversion. Microscopy revealed that the polypoid tumor was a hyperplastic polyp. 相似文献
987.
The aim of this study was to evaluate the histological and radiological osseointegration characteristics of implanted solvent-preserved cancellous bovine bone substitution material Tutobone after opening-wedge osteotomy and hip arthroplasty in human. The baseline hypothesis connected to the usage of bovine bone substitute materials is the assumption of temporary structural support, integration in the surrounding bone, bioresorption and replacement with vital bone. This hypothesis is based on numerous studies evaluating sintered bovine grafts showing good osseointegration and stability. Studies analyzing cancellous bovine grafts such as Tutobone hardly exist. The only rabbit defect model showed 100% remodeling of Tutobone after 26 weeks. However, no histological data are available on application of this xenograft in patients. In this study, nine patients biopsies were collected about 11 months after application of Tutobone. Unlike animal studies, the results showed incorporated avital graft remnants (47%) as well as new bone formation (53%) of the total mineralized area. Radiological evaluation confirmed increasing signs of osseointegration and an incomplete resorption. In conclusion, degradation and replacement of bovine graft seems to be less accelerated in patients than the animal study indicated. Nevertheless, Tutobone shows an excellent biocompatibility, good osteoconductive characteristics and may represent a useful alternative to autogenous graft. 相似文献
988.
Boige V Malka D Elias D Castaing M De Baere T Goere D Dromain C Pocard M Ducreux M 《Annals of surgical oncology》2008,15(1):219-226
Background We have previously shown promising activity of hepatic arterial infusion (HAI) oxaliplatin combined with intravenous (IV)
5-fluorouracil (5-FU) and leucovorin (LV) as first-line chemotherapy in patients with colorectal liver metastases (CRLM) (intent-to-treat
[ITT] objective response rate [ORR], 64%; secondary resection rate, 18%; overall survival [OS], 27 months). Whether this regimen
could be beneficial after systemic chemotherapy failure is unknown.
Methods Patients with unresectable CRLM and history of systemic chemotherapy failure were treated bimonthly with HAI oxaliplatin (100
mg/m2 2 hours) combined with IV LV and IV bolus and infusional 5FU (modified LV5FU2 regimen).
Results Forty-four consecutive patients (median age 56 years; median number of prior systemic chemotherapy regimens, 2 range 1–5)
were included, of whom 43 (98%) had previously received oxaliplatin (n = 34), irinotecan (n = 37), or both (n = 28). Patients received a median of nine cycles of HAI oxaliplatin and IV modified LV5FU2 (range 0–25). Toxicity included
grade 3–4 neutropenia (43%), grade 2–3 neuropathy (43%), and grade 3–4 abdominal pain (14%). We observed 24 partial ORs (62%)
among the 39 assessable patients (ITT ORR, 55%; 95% CI, 40–69%), including 17, 12, and 12 patients who had failed to respond
to prior systemic chemotherapy with FOLFIRI, FOLFOX, or both, respectively. Tumor response allowed further R0 surgical resection
(n = 7) or radiofrequency ablation (n = 1) of initially unresectable CRLM in eight patients (18%). Median progression-free survival and OS were 7 and 16 months,
respectively.
Conclusions HAI oxaliplatin and IV LV5FU2 is feasible, safe, and shows promising activity after systemic chemotherapy failure, allowing
surgical resection of initially unresectable CRLM in 18% of patients. 相似文献
989.
Retrospective study on the results of anterior corpectomy for the treatment of cervical myelopathy in patients over 70 years
old. To evaluate the surgical results of anterior corpectomy in aged patients with multilevel cervical myelopathy and to investigate
the probable pathomechanism by radiographic study. There are few data focused on the surgical results and post-operative complications
of anterior corpectomy in aged patients with cervical myelopathy. Twenty patients 70 years of age or older who underwent anterior
corpectomy, titanium mesh cage (TMC) reconstruction and anterior plate fixation for the treatment of compressive cervical
myelopathy were reviewed. The average age at the time of operation was 75 years. Neurologic deficits before and after surgery
were assessed using a scoring system proposed by the Japanese Orthopedic Association (JOA Score). Clinical results and post-operative
complications were compared with those of patients 69 years old or younger as a control. Pre-operative Radiologic evaluation
of every patient consisted of anterior–posterior, lateral, bilateral oblique, flextion, and extension radiographs, computed
tomography and magnetic resonance imaging of the cervical spine. Any factor causing spinal cord compression and the sign of
cervical instability were recorded. Surgical-related complications occurred in seven patients in the aged group. The incidence
of complications was 35% in the aged patient group and 9.7% in the control group respectively. Although the difference was
striking, no statistical significance was found between the two groups. One patient died of respiratory failure resulting
from pulmonary infection. The mortality rate was 5%. The pre-operative mean JOA score was 9.3 (from 3 to 14) in the aged patient
group. Nineteen patients were followed at least 2 years and the mean JOA score was 13.4 (from 8 to 17). 68.4% of the aged
patients achieved a good or excellent result. There was no statistical difference in the recovery rate of JOA score between
the aged group (58.1%) and control group (67.0%). In the pre-operative radiographs, the incidence of cervical instability
was much higher in the control group (32%) than in the aged group (5%) and multilevel cord compression caused by posterior
disc space osteophytes was more common in the aged group. Anterior corpectomy combined with TMC fusion and plate fixation
provides favorable neurologic recovery even in the patients over 70 years old. However, the incidence of surgical related
complications shows a conspicuous increasing in the aged patients. Overcompensation mechanism for cervical instability is
the probable cause of degenerative cervical spondylotic myelopathy in aged patients. 相似文献
990.
Hematuria is a common presenting symptom of urothelial malignancy. Although conventional urine analysis is very sensitive
in detecting the presence of hematuria, it is not specific in detecting bladder cancer or other urinary-tract cancers. The
noninvasive urinary tests NMP22 and UroVysion have been approved by the U.S. Food and Drug Administration for bladder cancer
screening. These tests have better sensitivity than cytology for detecting bladder cancer in patients who present with hematuria.
The positive predictive values of both tests increase in individuals with hematuria who have risk factors for bladder cancer.
Evaluating hematuria with sensitive markers, such as NMP22 and UroVysion, in high-risk populations offers an opportunity to
develop effective strategies for bladder cancer screening. 相似文献