全文获取类型
收费全文 | 102109篇 |
免费 | 6795篇 |
国内免费 | 1845篇 |
专业分类
耳鼻咽喉 | 1107篇 |
儿科学 | 2471篇 |
妇产科学 | 1989篇 |
基础医学 | 11975篇 |
口腔科学 | 3483篇 |
临床医学 | 9298篇 |
内科学 | 22543篇 |
皮肤病学 | 2417篇 |
神经病学 | 6871篇 |
特种医学 | 2256篇 |
外国民族医学 | 7篇 |
外科学 | 13279篇 |
综合类 | 6440篇 |
现状与发展 | 2篇 |
一般理论 | 23篇 |
预防医学 | 8703篇 |
眼科学 | 2214篇 |
药学 | 7625篇 |
53篇 | |
中国医学 | 2481篇 |
肿瘤学 | 5512篇 |
出版年
2024年 | 199篇 |
2023年 | 983篇 |
2022年 | 2245篇 |
2021年 | 4131篇 |
2020年 | 2639篇 |
2019年 | 3038篇 |
2018年 | 3624篇 |
2017年 | 2787篇 |
2016年 | 2549篇 |
2015年 | 3382篇 |
2014年 | 4549篇 |
2013年 | 5501篇 |
2012年 | 8510篇 |
2011年 | 8880篇 |
2010年 | 5473篇 |
2009年 | 4638篇 |
2008年 | 6683篇 |
2007年 | 6749篇 |
2006年 | 6206篇 |
2005年 | 5856篇 |
2004年 | 4789篇 |
2003年 | 4501篇 |
2002年 | 3820篇 |
2001年 | 1254篇 |
2000年 | 1152篇 |
1999年 | 998篇 |
1998年 | 606篇 |
1997年 | 491篇 |
1996年 | 439篇 |
1995年 | 376篇 |
1994年 | 305篇 |
1993年 | 232篇 |
1992年 | 351篇 |
1991年 | 310篇 |
1990年 | 225篇 |
1989年 | 201篇 |
1988年 | 184篇 |
1987年 | 159篇 |
1986年 | 156篇 |
1985年 | 161篇 |
1984年 | 138篇 |
1983年 | 116篇 |
1982年 | 98篇 |
1981年 | 116篇 |
1980年 | 98篇 |
1979年 | 97篇 |
1978年 | 72篇 |
1977年 | 90篇 |
1976年 | 62篇 |
1973年 | 60篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Robotic-assisted heller myotomy versus laparoscopic heller myotomy for the treatment of esophageal achalasia: multicenter study 总被引:3,自引:0,他引:3
Santiago Horgan M.D. Carlos Galvani M.D. Maria V. Gorodner M.D. Pablo Omelanczuck M.D. Fernando Elli M.D. Federico Moser M.D. Luis Durand M.D. Miguel Caracoche M.D. Jorge Nefa M.D. Sergio Bustos M.D. Phillip Donahue M.D. Pedro Ferraina M.D. 《Journal of gastrointestinal surgery》2005,9(8):1020-1030
Laparoscopic Heller myotomy (LHM) has become the standard treatment option for achalasia. The incidence of esophageal perforation
reported is about 5%–10%. Robotically assisted Heller myotomy (RAHM) is emerging as a safe alternative to LHM. Data comparing
the two approaches are scant. The aim of this study was to compare RAHM with LHM in terms of efficacy and safety for treatment
of achalasia. A total of 121 patients underwent surgical treatment of achalasia at three institutions. A retrospective review
of prospectively collected perioperative data was performed. Patients were divided into two groups: group A (RAHM), 59 patients,
and group B (LHM), 62 patients. All the operations were completed using minimally invasive techniques. There were 63 women
and 58 men, with a mean age of 45 ±19 years (14–82 years). Fifty-one percent of patients in group A and 95% of patients in
group B reported weight loss. Duration of symptoms was equal for both groups. Dysphagia was the main complaint in both groups
(P = NS). There was no difference in preoperative endoscopic treatment in both groups (44% versus 27%, P = NS). Operative
time was significantly shorter for LHM in the first half of the experience (141 ± 49 versus 122 ± 44 minutes, P < .05). However,
in the last 30 cases there was no difference in operative time between the groups (P = NS). Intraoperative complications (esophageal
perforation) were more frequent in group B (16% versus 0%). The incidence of postoperative heartburn did not differ by group.
There were no deaths. At 18 and 22 months, 92% and 90% of patients had relief of their dysphagia. This study suggests that
RAHM is safer than LHM, because it decreases the incidence of esophageal perforation to 0%, even in patients who had previous
treatment. At short-term follow-up, relief of dysphagia was equally achieved in both groups.
Presented at the Forty-Sixth Annual Meeting of The Society for Surgery of the Alimentary Tract, Chicago, Illinois, May 14–18,
2005 (oral presentation).
This study was supported in part by a grant provided by Intuitive Surgical, Inc. and Ethicon Endo-Surgery, Inc. 相似文献
92.
93.
J. M. Bellón N. García-Honduvilla N. Serrano M. Rodríguez G. Pascual J. Buján 《Hernia》2005,9(4):338-343
The component of a composite prosthesis, which makes contact with the visceral peritoneum, can be reabsorbable or non-reabsorbable,
and laminar or reticular. This study was designed to determine whether the composition of this second, barrier component could
improve its behavior at this interface. Abdominal wall defects in rabbits were repaired using a polypropylene prosthesis (PP),
or the composites Sepramesh (PP+h) or Vicryl (PP+v). Fourteen days after surgery, the implants were evaluated by light and
scanning electron microscopy, and immunohistochemistry. Prosthetic areas occupied by adhesions (PP: 71.08±5.09, PP+h: 18.55±4.96,
P+v: 69.69±16.81%), neoperitoneal thickness (PP: 256.17±21.68, PP+h: 83.11±19.63, PP+v:213.72±35.90 μm) and macrophage counts
(PP: 8.73±1.16, PP+h: 27.33±4.13, PP+v: 31.24±3.08%) showed significant differences (P<0.05). The tested biomaterials induced an optimal recipient tissue infiltration. Least adhesion formation was observed on
the PP+h implants. This suggests that the second component, although reabsorbable, should be smooth in structure. 相似文献
94.
95.
96.
Juan M. Bellón MD Julia Buján MD Natalio G. Honduvilla MD Alvaro Hernando MD Jacinto Navlet MD 《Annals of vascular surgery》1995,9(3):266-273
Various methods of cryopreservation of human endothelial cells (EC) were studied to determine their viability and behavior when seeded onto vascular prostheses made of polytetrafluoroethylene (PTFE). Three different protocols were used: (1) cyropreservation of whole umbilical vein, (2) cyropreservation of freshly extracted umbilical EC in suspension, and (3) cryopreservation of EC derived from a first subculture. Fresh EC and EC from a first subculture were used as controls. The viability and growth of these cells in culture media were studied, and basal prostacyclin levels were determined. The cells were assessed morphologically after they were seeded onto PTFE discs. Our results showed that the cryopreservation method that maintained the greatest viability was that in which previously cultured EC were used. Basal prostacyclin levels were significantly different following cyropreservation. However, when these cells were seeded onto PTFE discs their behavior was similar to that of fresh EC.We thank W. L. Gore & Associates for supplying the prostheses used in this study.Supported by a grant from the Comision Interministerial de Cieucia y Tecnologia SAF 92/0875. 相似文献
97.
Juan J. Muoz Cristina Roca Jos L. Santos Miguel Arroyo Rafael E. de Salamanca 《Basic & clinical pharmacology & toxicology》1993,73(4):189-191
Two alternatives for the treatment of lead intoxication, administration of zinc or a thiol donor, S-adenosyl-L-methionine (SAM), were analysed. Rats were exposed to lead (Pb)-acetate (60 mg/1) in drinking water during 90 days; one group also received SO4Zn in water (40 mg/l), while another received both Pb and SAM (5 mg/24 hr intraperitoneally. Erythrocytic δ-aminolaevulinic dehydratase (ALA-D) activity was significantly reduced (P<0.001) both in rats receiving Pb alone and in rats receiving Pb and each of the other two treatments. The high erythrocytic uroporphyrinogen synthetase (URO-S) activity noticed in Pb administered rats, was significantly (P< 0.001) reduced in animals treated either with zinc or with SAM. Hepatic ALA-D activity tended to decrease while renal enzyme activity was not modified by the low level Pb exposure used in this work. Interestingly, SAM treated rats in both tissues exhibited significantly (P<0.01) higher activities of the enzyme. It is argued that SAM treatment causes a surplus of thiols that allows the full expression of ALA-D catalytic activity. 相似文献
98.
Ignacio Alvarez Alvarez M.D. Pedro Sanchez Lazo Ph.D. Sofia Ramos Gonzalez Ph.D. J. Pablo Rodrigo Tapia M.D. Faustino Nunez Batalla M.D. Carlos Suarez Nieto M.D. 《American journal of otolaryngology》1997,18(6):375
Purpose: Increasingly, evidence has shown that human papillomavirus (HPV) plays a role in the induction of certain carcinomas. The presence of HPV sequences in 56 previously untreated oral and pharyngolaryngeal carcinomas was examined by the polymerase chain reaction (PCR).Materials and Methods: After DNA extraction, samples underwent 40 replication cycles with specific oligonucleotide primers corresponding to sequences from the E6 open-reading frame of HPV-6b, HPV-16, and HPV-18. To determine the E6 genomic integration, positive samples were processed with specific primers for the corresponding HPV L1 genes. Genomic HPV DNA cloned into PBR 322 was used as positive control.Results: HPV E6 DNA of the 6b and 16 types was detected in 14 patients (25%). The L1 gene was not present.Conclusion: Detected HPV E6 DNA might be integrated into the cell genome in the positive cases as indicated by the absence of the L1 gene-coding for the viral capside. Histological and clinical parameters, such as tumor location, degree of differentiation, stage, recurrence, and survival rates, were unrelated to the presence of HPV. 相似文献
99.
本研究经杀菌试验和免疫后保护力试验探讨小鼠巨噬细胞在抗白色念珠菌感染中的作用,结果表明白色念珠菌酵母形体对巨噬细胞杀伤作用的抵抗力及对小鼠的毒力均较菌丝形体强。小鼠体内不同部位巨噬细胞杀伤白色念珠菌的作用不同,脾脏巨噬细胞作用大于腹腔残存巨噬细胞。经白色念珠菌活菌静脉免疫后脾巨噬细胞杀白色念珠菌作用增强,但其对再感染的抵抗力不增强。 相似文献
100.
Pulmonary tuberculosis associated with membranous nephropathy 总被引:1,自引:0,他引:1