全文获取类型
收费全文 | 6929篇 |
免费 | 766篇 |
国内免费 | 53篇 |
专业分类
耳鼻咽喉 | 119篇 |
儿科学 | 206篇 |
妇产科学 | 196篇 |
基础医学 | 868篇 |
口腔科学 | 112篇 |
临床医学 | 1025篇 |
内科学 | 1289篇 |
皮肤病学 | 92篇 |
神经病学 | 615篇 |
特种医学 | 307篇 |
外科学 | 769篇 |
综合类 | 111篇 |
预防医学 | 859篇 |
眼科学 | 131篇 |
药学 | 588篇 |
1篇 | |
中国医学 | 14篇 |
肿瘤学 | 446篇 |
出版年
2021年 | 94篇 |
2020年 | 65篇 |
2019年 | 86篇 |
2018年 | 127篇 |
2017年 | 103篇 |
2016年 | 102篇 |
2015年 | 140篇 |
2014年 | 154篇 |
2013年 | 221篇 |
2012年 | 289篇 |
2011年 | 303篇 |
2010年 | 211篇 |
2009年 | 220篇 |
2008年 | 270篇 |
2007年 | 337篇 |
2006年 | 281篇 |
2005年 | 290篇 |
2004年 | 239篇 |
2003年 | 264篇 |
2002年 | 227篇 |
2001年 | 213篇 |
2000年 | 243篇 |
1999年 | 235篇 |
1998年 | 154篇 |
1997年 | 153篇 |
1996年 | 122篇 |
1995年 | 99篇 |
1994年 | 79篇 |
1993年 | 103篇 |
1992年 | 172篇 |
1991年 | 181篇 |
1990年 | 175篇 |
1989年 | 183篇 |
1988年 | 168篇 |
1987年 | 150篇 |
1986年 | 136篇 |
1985年 | 124篇 |
1984年 | 84篇 |
1983年 | 83篇 |
1982年 | 65篇 |
1981年 | 66篇 |
1980年 | 66篇 |
1979年 | 66篇 |
1978年 | 54篇 |
1977年 | 39篇 |
1976年 | 36篇 |
1975年 | 35篇 |
1974年 | 36篇 |
1973年 | 38篇 |
1972年 | 42篇 |
排序方式: 共有7748条查询结果,搜索用时 31 毫秒
81.
Gillian Rice Jenny Ingram Jacques Mizan 《The British journal of general practice》2008,58(552):465-470
BACKGROUND: Few studies have examined the effect on patients and staff of the physical environment in primary care facilities. AIM: To explore changes in patient and staff satisfaction, patient anxiety, and patient-doctor communication when a GP surgery moves from old premises to enhanced purpose-built accommodation. DESIGN OF STUDY: Questionnaire surveys, interviews, and focus groups pre- and post move. SETTING: An urban general practice in Bristol. METHOD: Patient questionnaires assessed anxiety (Spielberger State-Trait Anxiety Inventory; STAI), satisfaction with the environment, and communication during the consultation. Staff questionnaires assessed satisfaction with the environment and job satisfaction. Qualitative methods explored patient and staff views in more depth. RESULTS: A total of 1118 pre-move and 954 post-move patient questionnaires showed significant increases in satisfaction scores for reception/waiting areas (mean 6.46, 95% confidence interval [CI]=5.97 to 6.95) and consulting rooms (mean 3.80, 95% CI=3.44 to 4.15) in the new premises. Patients' satisfaction with patient-doctor communication also increased (mean 0.88, 95% CI=0.30 to 1.46) and anxiety scores were significantly reduced before and after the consultation in the new premises compared with the old (STAI mean difference before consultation 0.72, 95% CI=0.37 to 1.08; mean after consultation 0.37, 95% CI=0.03 to 0.72). Patients highlighted the increased space and light, more modern appearance, greater comfort, and novel works of art in the new surgery. Staff workplace satisfaction increased significantly after moving and remained higher than in the old building. CONCLUSION: This large-scale study examining the effects of a UK primary care environment on patients and staff shows that an enhanced environment is associated with improvements in patients' perception of patient-doctor communication, reduction in anxiety, and increases in patient and staff satisfaction. 相似文献
82.
Cytokeratin subsets can reliably distinguish Barrett's esophagus from intestinal metaplasia of the stomach 总被引:19,自引:0,他引:19
Ormsby AH Goldblum JR Rice TW Richter JE Falk GW Vaezi MF Gramlich TL 《Human pathology》1999,30(3):288-294
The histological distinction between intestinal metaplasia involving the distal esophagus (Barrett's esophagus [BE]) and intestinal metaplasia of the stomach has important clinical implications and can be difficult even with the use of histochemical mucin stains. Cytokeratin (CK) 7 and 20 are cytoplasmic structural proteins that show restricted expression in normal and malignant epithelia of the gastrointestinal tract. The aim of this study was to determine the use of CK7 and 20 expression in the histological distinction of BE from gastric intestinal metaplasia. CK7 and 20 immunostaining was performed on randomly selected surgical resection (n = 31) and biopsy specimens (n = 34) from patients with long-segment BE and gastric resection specimens (n = 11) and gastric cardia biopsy specimens (n = 13) in patients with histological evidence of intestinal metaplasia. A unique pattern of immunoreactivity designated the Barrett's CK7/20 pattern showed superficial CK20 staining and strong CK7 staining of both superficial and deep glands in 29 of 31 (94%) esophageal resection specimens and 34 of 34 (100%) esophageal biopsy specimens form patients with long-segment BE. A Barrett's CK7/20 pattern was not observed in gastric cardia biopsy specimens (n = 13) or gastric resection specimens (n = 11) in patients with histological evidence of intestinal metaplasia. The sensitivity, specificity, and positive predictive value of a Barrett's CK7/20 pattern for a diagnosis of long-segment BE was 97%, 100%, and 100%, respectively. CK7 and 20 reactivity patterns can reliably identify the location of intestinal metaplasia in the esophagus and stomach using histological material from both routine endoscopic biopsy and surgical resection specimens. 相似文献
83.
84.
Mervis CB Morris CA Klein-Tasman BP Bertrand J Kwitny S Appelbaum LG Rice CE 《Developmental neuropsychology》2003,23(1-2):243-268
Two studies were conducted to consider the looking behavior of infants and toddlers with Williams syndrome (WS).In Study 1,the looking behavior of a 10-month-old girl with WS during play sessions with her mother and with a stranger was compared to that of 2 groups of infants who were developing normally (ND),1 matched for chronological age and the other for developmental age. The infant with WS spent more than twice as much time looking at her mother as the infants in either contrast group did. She also spent twice as much time looking at the stranger.In addition, during 78%of this time, her gaze at the stranger was coded as extremely intense. Looks of this intensity were virtually never made by the ND infants. In Study 2,the looking behavior of 31 individuals with WS ages 8 to 43 months during a genetics evaluation was compared to that of 319 control children in the same age range (242 with developmental delay due to causes other than WS).Twenty-three of the 25 participants with WS aged 33 months or younger demonstrated extended and intense looking at the geneticist. In contrast, none of the control participants looked extensively or intently at the geneticist. Findings are discussed in the context of previous research on arousal and focused attention during normal development and on temperament and personality of older children and adults with WS. It is argued that the unusual looking patterns evidenced by infants and toddlers with WS presage the unusual temperament and personality of older individuals with WS, and the possibility of a genetic basis for these behaviors is addressed. 相似文献
85.
Febrile-range hyperthermia augments pulmonary neutrophil recruitment and amplifies pulmonary oxygen toxicity
下载免费PDF全文
![点击此处可从《The American journal of pathology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Hasday JD Garrison A Singh IS Standiford T Ellis GS Rao S He JR Rice P Frank M Goldblum SE Viscardi RM 《The American journal of pathology》2003,162(6):2005-2017
Febrile-range hyperthermia (FRH) improves survival in experimental infections by accelerating pathogen clearance, but may also increase collateral tissue injury. We hypothesized that FRH would worsen the outcome of inflammation stimulated by a non-replicating agonist and tested this hypothesis in a murine model of pulmonary oxygen toxicity. Using a conscious, temperature-controlled mouse model, we showed that maintaining a core temperature at FRH (39 degrees C to 40 degrees C) rather than at euthermic levels (36.5 degrees C to 37 degrees C) during hyperoxia exposure accelerated lethal pulmonary vascular endothelial injury, reduced the inspired oxygen threshold for lethality, induced expression of granulocyte-colony stimulating factor, and expanded the circulating neutrophil pool. In these same mice, FRH augmented pulmonary expression of the ELR(+) CXC chemokines, KC and LPS-induced CXC chemokine, enhanced recruitment of neutrophils, and changed the histological pattern of lung injury to a neutrophilic interstitial pneumonitis. Immunoblockade of CXC receptor-2 abrogated neutrophil recruitment, reduced pulmonary vascular injury, and delayed death. These combined data demonstrate that FRH may enlist distinct mediators and effector cells to profoundly shift the host response to a defined injurious stimulus, in part by augmenting delivery of neutrophils to sites of inflammation, such as may occur in infections. In certain conditions, such as in the hyperoxic lung, this process may be deleterious. 相似文献
86.
Teenagers' health concerns: implications for primary health care professionals. 总被引:3,自引:4,他引:3
下载免费PDF全文
![点击此处可从《The British journal of general practice》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Four hundred and eighty five students, aged 13-15 years, at nine comprehensive schools in the London borough of Brent completed a questionnaire about health-related behaviours and health concerns. Among general health concerns, most prominent were weight, acne, nutrition and exercise. There appeared to be a considerable unmet need to discuss sexual development, sexually transmitted diseases and contraception. A substantial proportion (16% of the girls and 3% of the boys) reported sexual abuse, but few wished to discuss this with a doctor or nurse. Although a relatively high percentage of the students smoked and a smaller percentage used alcohol or drugs regularly, there was little concern or interest in discussing these matters with a health professional. Most of the schools did not have a formal health education programme, and in none of them were health professionals available for discussion of the issues under study. There appears to be a need for more comprehensive health education in schools and for primary health care professionals, particularly general practitioners to raise these issues opportunistically with their teenage patients. 相似文献
87.
Tumor cell-endothelial interactions. Increased adhesion of human melanoma cells to activated vascular endothelium. 总被引:10,自引:3,他引:10
下载免费PDF全文
![点击此处可从《The American journal of pathology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
G. E. Rice M. A. Gimbrone Jr M. P. Bevilacqua 《The American journal of pathology》1988,133(2):204-210
The authors examined the adhesion of seven human melanoma cell lines to cultured human umbilical vein endothelial cells (HEC) that were activated by cytokines or bacterial endotoxin. The adhesion of Hs 294T and MEL-24 cells was markedly increased (approximately 2 to 12-fold) after pretreatment of HEC monolayers for 6 hours with tumor necrosis factor, interleukin-1, or endotoxin. Smaller increases were noted with the cell lines RPMI 7951, HT 144, Malme-3M, MEL-2, and no significant increase was observed with MEL-5. Cytokine and endotoxin effects on melanoma-HEC adhesion were concentration- and time-dependent, with onset by 2 hours, peak at 6-8 hours and maintenance through 48 hours. Cytokine induction of increased HEC adhesiveness for melanoma cells was blocked by actinomycin-D or cycloheximide, suggesting the requirement for RNA and protein synthesis. Interaction of melanoma cells with subendothelial matrix did not appear to play a primary role because: 1) phase contrast and electron microscopy revealed direct contact between tumor cells and endothelial cells in standardized monolayer adhesion assays; 2) increased adhesion (rosette formation) of tumor cells to activated HEC was also observed after nonenzymatic resuspension of HEC, and 3) the matrix peptide GRGDSP partially blocked (approximately 45%) Hs 294T cell adhesion to subendothelial matrix, but had little or no effect on adhesion to activated HEC monolayers. Taken together, these data suggest that inducible HEC surface changes may mediate the adhesion of certain melanoma cells, thereby exerting an active influence over the metastatic process. 相似文献
88.
Lectin characterization of gonococci from an outbreak caused by penicillin-resistant Neisseria gonorrhoeae. 总被引:1,自引:0,他引:1
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
W O Schalla R J Rice J W Biddle Y Jeanlouis S A Larsen W L Whittington 《Journal of clinical microbiology》1985,22(4):481-483
A total of 40 Neisseria gonorrhoeae isolates, representing 19 penicillin-resistant isolates (from 8 heterosexual patients and 11 homosexual patients) and 21 penicillin-susceptible isolates (from 15 heterosexual patients and 6 homosexual patients) and obtained from the same geographic area, were examined. Lectin agglutination patterns were based on the reactivity of the isolates with the following 14 lectins: concanavalin A, Lens culinaris, Trichosanthes kinlowii, Griffonia simplicifolia I, Arachis hypogeae (peanut agglutinin), Glycine max (soybean agglutinin), Dolichos bifloris, Griffonia simplicifolia II, Solanum tuberosum (potato starch agglutinin), Triticum vulgaris (wheat germ agglutinin), Limax flavus, Phaseolus vulgaris, Ulex europaeus I, and Lotus tetragonolobus. All isolates were serotyped with monoclonal antibodies specific for gonococcal outer membrane protein I and auxotyped, and the plasmid content was determined. Resistant patient isolates were selected for their decreased penicillin susceptibility, and control isolates were selected for their penicillin susceptibility. Even though the patient isolates demonstrated resistance to penicillin, no phenotypic differences in lectin-grouping patterns were demonstrated between the two study groups; i.e., two predominant lectin groups were observed. No resistance-associated plasmids were detected. All patient isolates were serogroup IB (serovars IB-1, IB-2, and IB-4), whereas 12 of 21 control isolates were serogroup IA (P less than 0.05). Isolates obtained from different anatomical sites in the same patient (cervical and rectal) agreed with regard to lectin patterns and serovars but not auxotypes. 相似文献
89.
Rice WP 《Journal of clinical engineering》1996,21(4):332-338
Clinical engineering programs typically establish the content and frequency of a device's inspection and preventive maintenance procedures at the time of implementation. In some programs, these are not altered throughout the device's useful life. In others, history data and traditional statistical methods are used to adapt procedures to change in risk measures. Such methods are essentially reactive in that they are based upon past trends and do not readily consider potentialities for future change in the performance and utilization environments. Chaos theoretical concepts and related measures, when implemented in artificial intelligence programs such as neural networks and genetic algorithms, and used as an adjunct with computerized technology management programs, can assist in asking and answering the more dynamic, proactive questions necessary for effective inspection and preventive maintenance optimization. Today's healthcare environment is ideal for exploring their utilization. 相似文献
90.
Permanent impairment of embryo development by hydrosalpinges 总被引:6,自引:9,他引:6
Recent reports suggest a deleterious effect of hydrosalpinges on pregnancy
outcome for in-vitro fertilization (IVF) and improvement following surgical
treatment. We compared the effect of hydrosalpinx on pregnancy outcome in
286 patients having 348 IVF cycles and followed the development of
untransferred embryos for 7 days to determine if hydrosalpinges affect
oocyte quality or embryo development. The delivery rate per retrieval was
significantly lower for patients with hydrosalpinx, but was restored by
surgical treatment to that of patients without hydrosalpinx. However, the
implantation rate per embryo transferred and normal blastulation of
untransferred embryos, which were significantly decreased in patients with
hydrosalpinx, and growth arrest and degeneration of untransferred embryos,
which were significantly increased compared to patients without
hydrosalpinx, were not restored by surgical treatment of hydrosalpinges. We
conclude that surgical treatment of hydrosalpinges decreases early
pregnancy loss and improves pregnancy outcome, possibly by diminishing
reversible deleterious effects exerted on the endometrium. As we have seen
in our laboratory, hydrosalpinges may have a permanent negative influence
on ovarian function, follicular development and oocyte quality since
implantation of transferred embryos and normal blastulation of
untransferred embryos remain low, and in-vitro growth arrest and
degeneration remain high despite surgical treatment of hydrosalpinges.
相似文献