全文获取类型
收费全文 | 24686篇 |
免费 | 2538篇 |
国内免费 | 113篇 |
专业分类
耳鼻咽喉 | 198篇 |
儿科学 | 930篇 |
妇产科学 | 665篇 |
基础医学 | 3520篇 |
口腔科学 | 396篇 |
临床医学 | 3551篇 |
内科学 | 5281篇 |
皮肤病学 | 579篇 |
神经病学 | 2560篇 |
特种医学 | 565篇 |
外国民族医学 | 4篇 |
外科学 | 2437篇 |
综合类 | 224篇 |
一般理论 | 9篇 |
预防医学 | 2520篇 |
眼科学 | 312篇 |
药学 | 1643篇 |
中国医学 | 19篇 |
肿瘤学 | 1924篇 |
出版年
2023年 | 254篇 |
2022年 | 389篇 |
2021年 | 774篇 |
2020年 | 615篇 |
2019年 | 929篇 |
2018年 | 1018篇 |
2017年 | 796篇 |
2016年 | 842篇 |
2015年 | 896篇 |
2014年 | 1084篇 |
2013年 | 1480篇 |
2012年 | 1877篇 |
2011年 | 1770篇 |
2010年 | 1131篇 |
2009年 | 1014篇 |
2008年 | 1530篇 |
2007年 | 1528篇 |
2006年 | 1401篇 |
2005年 | 1315篇 |
2004年 | 1244篇 |
2003年 | 1108篇 |
2002年 | 1030篇 |
2001年 | 242篇 |
2000年 | 214篇 |
1999年 | 236篇 |
1998年 | 251篇 |
1997年 | 199篇 |
1996年 | 155篇 |
1995年 | 154篇 |
1994年 | 136篇 |
1993年 | 113篇 |
1992年 | 102篇 |
1991年 | 99篇 |
1990年 | 97篇 |
1989年 | 96篇 |
1988年 | 71篇 |
1987年 | 65篇 |
1986年 | 76篇 |
1985年 | 74篇 |
1984年 | 77篇 |
1983年 | 68篇 |
1982年 | 74篇 |
1981年 | 77篇 |
1980年 | 49篇 |
1979年 | 40篇 |
1978年 | 47篇 |
1977年 | 52篇 |
1976年 | 52篇 |
1975年 | 45篇 |
1974年 | 49篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Frequency of structural abnormalities of the long arm of chromosome 12 in myelofibrosis with myeloid metaplasia 总被引:2,自引:0,他引:2
Andrieux J Demory JL Morel P Plantier I Dupriez B Caulier MT Bauters F Laï JL 《Cancer Genetics and Cytogenetics》2002,137(1):68-71
Among cytogenetic studies of 205 patients diagnosed as myelofibrosis with myeloid metaplasia, we found seven cases with structural abnormalities of the long arm of chromosome 12. The karyotype showed six balanced translocations, that is, t(4;12)(q33;q21), t(5;12)(p14;q21), t(1;12)(q22;q24), t(12;17)(q24;q11), t(7;12) (p11;q24), and t(1;12)(p12;q24), as well as other cytogenetic abnormalities such as del(12)(q21;q24) and inv(12) (p12q24). Some isolated cases involving the 12q21 region have also been described in the literature. Importance of rearrangement of chromosome 12 in 12q21 or 12q24 is underlined by the authors suggesting a proto-oncogene accountable mechanism of leukemogenesis. 相似文献
992.
Roll P Zattara-Cannoni H Bustos-Bernard MC Curtillet C Michel G Vagner-Capodano AM 《Cancer Genetics and Cytogenetics》2002,135(2):187-191
Fluorescence in situ hybridization (FISH) analysis in a case of infant acute monocytic leukemia M5 revealed a complex rearrangement between chromosomes 10 and 11, leading to the disruption of the MLL gene. Using two painting probes for chromosomes 10 and 11 and a specific probe for the MLL gene localized on 11q23, we observed a paracentric inversion of the 11q13-q23 fragment translocated to 10p12. Molecular analysis showed that AF10 localized on 10p12 was the fusion partner gene of MLL in this rearrangement (10;11). This report underlined the usefulness of FISH and molecular techniques in identifying complex rearrangements. 相似文献
993.
Utilization of acidophil bodies in the diagnosis of recurrent hepatitis C infection after orthotopic liver transplantation. 总被引:1,自引:0,他引:1
Romil Saxena James M Crawford Victor J Navarro Amy L Friedman Marie E Robert 《Modern pathology》2002,15(9):897-903
BACKGROUND: The distinction between acute rejection and early recurrent hepatitis C infection (RHCV) in the setting of orthotopic liver transplantation is often difficult. In liver biopsies acidophil bodies and lobular hepatitis are used to suggest a diagnosis of RHCV over rejection, however, the reliability of this practice has not been established. Because portal tract changes in RHCV and rejection often overlap, we sought to determine whether the degree of hepatocyte acidophil body formation seen on liver biopsies could be used to distinguish between these two conditions. METHODS: Quantification of acidophil bodies was performed on liver biopsies in orthotopic liver transplant patients with RHCV (n = 10), non-hepatitis C orthotopic liver transplant patients with uncomplicated rejection episodes (n = 10) and non-transplant patients with chronic hepatitis C infection (n = 10). Hematoxylin and Eosin stained slides from all three groups were randomized and tissue segments 1.0 cm in length and of variable width (0.04-0.13 cm) were examined at 200x magnification in a blinded fashion by two pathologists in order to quantify the number of acidophil bodies/cm(2). Lobular chronic inflammation was also graded on a 0-3+ scale. RESULTS: Liver biopsies taken at the onset of RHCV exhibited 606 +/- 101 acidophil bodies/cm(2) (mean +/- standard error of mean, range 200-1390). These counts were significantly greater (P =.0061, paired 2-tailed t-test) than the 241 +/- 53 acidophil bodies/cm(2) (range 80-514) for acute rejection, and the 194 +/- 21 acidophil bodies/cm(2) (range 100-333) for non-liver transplant chronic hepatitis C infection (P =.0013). No difference in lobular inflammation between index RHCV and rejection biopsies was detected. CONCLUSIONS: Although there is overlap, on average there are twice as many acidophil bodies in the initial stage of RHCV when compared with acute rejection (average of 55 per linear cm in RHCV versus 21 per linear cm for rejection). Lobular inflammation was not a reliable indicator of the initial onset of RHCV. 相似文献
994.
This paper reviews the model-building approach to developmental psychopathology as it applies to understanding the influence of peers on adolescent problem behavior. Considerable longitudinal evidence suggests that deviant peer involvement is prognostic of escalations in various forms of problem behavior, including substance use, delinquent behavior, and violence. Most convincing, however, are data from randomized intervention trials that show alarming iatrogenic effects for aggregating high-risk peers. This paper shows that intervention research can also clarify the role of parents in reducing deviant peer involvement. Results from a 4-year prevention trial are reported for a community sample of multiethnic middle school youth. Random assignment to family-centered services in a school Family Resource center produced reduced growth in deviant peer involvement. The extensiveness of the parenting intervention was correlated with reduced growth in deviant peer involvement, especially among high-risk youth. Findings are discussed with respect to developmental theory and the design of future intervention trials that clarify the role of adults in structuring the emerging adolescents' world of peers. 相似文献
995.
Trouette H Dubus P Belleannee G Charmoy MC Parrens M Velly JF Merlio JP de Mascarel A 《Endocrine pathology》2002,13(3):235-238
Most of the primary thyroid malignant lymphomas have been considered of mucosa-associated lymphoid tissue (MALT) type and
arise from lymphocytic thyroiditis. We report an uncommon case of a 67-yr-old man who underwent total thyroidectomy for multinodular
goiter with tracheal compression. At histopathologic examination, we discovered a minute (3-mm diameter) lesion of low-grade
thyroid lymphoma of MALT type without any lymphocytic thyroiditis lesion on 33 section levels of the entire thyroid gland.
No general inflammatory, autoimmune, or lymphomatous disorder has been evidenced both at staging and after 30 mo of follow-up.
MALT-type low-grade lymphoma may, in some instances, develop de novo within the thyroid without an antecedent MALT-type lymphoma. 相似文献
996.
Teasdale JD Moore RG Hayhurst H Pope M Williams S Segal ZV 《Journal of consulting and clinical psychology》2002,70(2):275-287
Metacognitive awareness is a cognitive set in which negative thoughts/feelings are experienced as mental events, rather than as the self. The authors hypothesized that (a) reduced metacognitive awareness would be associated with vulnerability to depression and (b) cognitive therapy (CT) and mindfulness-based CT (MBCT) would reduce depressive relapse by increasing metacognitive awareness. They found (a) accessibility of metacognitive sets to depressive cues was less in a vulnerable group (residually depressed patients) than in nondepressed controls; (b) accessibility of metacognitive sets predicted relapse in residually depressed patients; (c) where CT reduced relapse in residually depressed patients, it increased accessibility of metacognitive sets; and (d) where MBCT reduced relapse in recovered depressed patients, it increased accessibility of metacognitive sets. CT and MBCT may reduce relapse by changing relationships to negative thoughts rather than by changing belief in thought content. 相似文献
997.
Elliott AM Gonzales M Hoeffel JC Le Merrer M Maroteaux P Encha-Razavi F Joye N Berchel C Fliegel C Aughton DJ Beaudry-Rodgers K Hasteh F Nerlich AG Wilcox WR Rimoin DL Lachman RS Freisinger P 《American journal of medical genetics》2002,109(2):139-148
Neu-Laxova Syndrome (NLS) is a severe disorder with intrauterine growth retardation, edema, and characteristic face (including microcephaly with receding forehead, protuberant eyes, a flattened nose, deformed ears, cleft palate, and micrognathia). Ichthyosis is often present. Limb anomalies include hypoplastic fingers and syndactyly of fingers and toes. Patients are usually stillborn or die shortly after birth. We report five unrelated patients--four with atypical NLS and one with typical NLS. All five patients were stillbirths. Clinically, the atypical NLS patients showed a large skull; rhizo-, meso-, and acromelia; and hypoplasia of the metacarpals and phalanges. The feet were similarly affected. Radiographically, the atypical patients showed interpediculate narrowing and hypoplastic vertebral bodies. The long bones were stick-like, showing diaphyseal widening that spared the metaphyses and was more pronounced in the lower extremities. The ilia had a half-moon configuration with widening of the sacrosciatic notches. The ischia were vertical and the pubic bone was absent. The typical NLS patient showed microcephaly, normal vertebral body, and long bone ossification, but a pelvic configuration similar to that of the atypical NLS patients. The common and distinguishing clinical and radiographic features are reviewed. Scott et al. [1981: Am J Med Genet 9:165-175] described two patients with NLS with radiographic and clinical findings similar to patients 1-4 reported here. Patients 1-4 of this report lack the typical findings of NLS and likely represent a distinct lethal skeletal dysplasia. 相似文献
998.
Utility of a multiplex PCR assay for detecting herpesvirus DNA in clinical samples 总被引:4,自引:0,他引:4 下载免费PDF全文
Druce J Catton M Chibo D Minerds K Tyssen D Kostecki R Maskill B Leong-Shaw W Gerrard M Birch C 《Journal of clinical microbiology》2002,40(5):1728-1732
A multiplex PCR was designed to amplify herpes simplex virus types 1 and 2, cytomegalovirus, and varicella-zoster virus DNA present in a diverse range of clinical material. The susceptibility of these viruses to in vivo inhibition by at least one antiviral drug was an important consideration in their inclusion in the multiplex detection system. An aliquot of equine herpesvirus was introduced into each specimen prior to extraction and served as an indicator of potential inhibitors of the PCR and a detector of suboptimal PCR conditions. Compared to virus isolation and immunofluorescence-based antigen detection, the multiplex assay yielded higher detection rates for all viruses represented in the assay. The turnaround time for performance of the assay was markedly reduced compared to those for the other techniques used to identify these viruses. More than 21,000 tests have been performed using the assay. Overall, the multiplex PCR enabled the detection of substantially increased numbers of herpesviruses, in some cases in specimens or anatomical sites where previously they were rarely if ever identified using traditional detection methods. 相似文献
999.
Identification of two phylogenetically related organisms from feces by PCR for detection of Salmonella spp 下载免费PDF全文
Gentry-Weeks C Hutcheson HJ Kim LM Bolte D Traub-Dargatz J Morley P Powers B Jessen M 《Journal of clinical microbiology》2002,40(4):1487-1492
Two previously reported PCR methods were evaluated to determine whether they are as sensitive and specific as conventional culture methods in detecting Salmonella spp. from feces. Bovine and equine feces were enriched overnight in brain heart infusion broth and assayed using PCR methods and primer sets described by other investigators. A total of 774 fecal specimens were tested using a primer set (invE-A primer set) that amplifies a region spanning the invasin E and A genes of Salmonella enterica serovar Typhimurium. A subset of these fecal specimens (306 of the 774 total) were tested using primers (hisJ primer set) that amplify a portion of the histidine transport J gene. The PCR required 24 h to obtain results, whereas it took 5 to 7 days to identify Salmonella spp. by culture. PCR detection of Salmonella spp. using the hisJ primers and the invE-A primers had a sensitivity of 93.3 and 80%, respectively, and a specificity of 85.6 and 98.6%, respectively, compared with bacterial culture. Amplification of 42 culture-negative fecal specimens (of 306 total specimens) generated a DNA fragment that corresponded to the molecular weight of the amplified hisJ gene. The hisJ-generated amplicons from six culture-negative and six culture-positive specimens were sequenced and analyzed using DNA sequence alignment and phylogenetic analysis software. A neighbor-joining dendrogram of the DNA sequences of both sets of hisJ amplicons revealed two distinct groups-one group of amplicons from culture-positive specimens identical to the hisJ gene of S. enterica serovar Typhimurium and a second group of amplicons from culture-negative specimens that were more closely related to hisJ of S. enterica serovar Typhimurium than to other hisJ sequences present in nucleotide databases. 相似文献
1000.
Monitoring of basophil activation using CD63 and CCR3 in allergy to muscle relaxant drugs 总被引:12,自引:0,他引:12
Monneret G Benoit Y Debard AL Gutowski MC Topenot I Bienvenu J 《Clinical immunology (Orlando, Fla.)》2002,102(2):192-199
Allergic or pseudoallergic reactions that occur during anesthesia have been increasing for the last few years. To date, the diagnosis of allergy to muscle relaxants remains difficult. In this respect, we developed a flow cytometric method for the study of drug-induced basophil degranulation using CD63 and CCR3. Fifty patients who developed clinical features evocative of allergic reactions immediately after induction of anesthesia were included and classified into two groups. Group 1 (n = 39) comprised true allergic patients, who developed typical signs of shock associated to positive skin testing. Group 2 (n = 11) consisted of patients whose clinical history was not typical and skin testing was negative or nonconclusive. Seventeen control subjects were also studied in this report. We compared data from flow cytometry to skin tests, specific IgE, and histamine release results. Flow cytometry showed a sensitivity of 54%, while that of specific IgE was similar, at 62%. Interestingly, when considering the sensitivity of IgE + CD63 for diagnosis, we reached a sensitivity value of 80%. Of 15 negative results for specific IgE, we found 7 positive CD63 tests, while histamine release gave positive results in only 2 cases. Furthermore, the CD63 protocol showed good specificity (100%). We conclude that our flow cytometry protocol is a promising tool in allergy diagnosis since it is specific and complementary to specific IgE detection. 相似文献