全文获取类型
收费全文 | 5741篇 |
免费 | 445篇 |
国内免费 | 16篇 |
专业分类
耳鼻咽喉 | 37篇 |
儿科学 | 241篇 |
妇产科学 | 114篇 |
基础医学 | 651篇 |
口腔科学 | 140篇 |
临床医学 | 636篇 |
内科学 | 1275篇 |
皮肤病学 | 60篇 |
神经病学 | 452篇 |
特种医学 | 431篇 |
外科学 | 802篇 |
综合类 | 97篇 |
一般理论 | 3篇 |
预防医学 | 399篇 |
眼科学 | 115篇 |
药学 | 320篇 |
中国医学 | 7篇 |
肿瘤学 | 422篇 |
出版年
2021年 | 80篇 |
2020年 | 57篇 |
2019年 | 64篇 |
2018年 | 84篇 |
2017年 | 75篇 |
2016年 | 60篇 |
2015年 | 80篇 |
2014年 | 114篇 |
2013年 | 220篇 |
2012年 | 209篇 |
2011年 | 217篇 |
2010年 | 162篇 |
2009年 | 133篇 |
2008年 | 185篇 |
2007年 | 211篇 |
2006年 | 194篇 |
2005年 | 202篇 |
2004年 | 191篇 |
2003年 | 184篇 |
2002年 | 162篇 |
2001年 | 177篇 |
2000年 | 175篇 |
1999年 | 139篇 |
1998年 | 95篇 |
1997年 | 97篇 |
1996年 | 113篇 |
1995年 | 98篇 |
1994年 | 106篇 |
1993年 | 97篇 |
1992年 | 148篇 |
1991年 | 140篇 |
1990年 | 129篇 |
1989年 | 174篇 |
1988年 | 162篇 |
1987年 | 149篇 |
1986年 | 134篇 |
1985年 | 138篇 |
1984年 | 94篇 |
1983年 | 83篇 |
1982年 | 56篇 |
1981年 | 47篇 |
1980年 | 59篇 |
1979年 | 78篇 |
1978年 | 47篇 |
1977年 | 54篇 |
1976年 | 65篇 |
1975年 | 58篇 |
1972年 | 39篇 |
1971年 | 39篇 |
1970年 | 33篇 |
排序方式: 共有6202条查询结果,搜索用时 319 毫秒
51.
Proteus syndrome 总被引:2,自引:0,他引:2
C P Samlaska S W Levin W D James P M Benson J C Walker P C Perlik 《Archives of dermatology》1989,125(8):1109-1114
The term Proteus syndrome was coined in 1983 to describe a disorder of skeletal, hamartomatous, and other mesodermal malformations. The syndrome was named after the Greek god Proteus, whose name means "the Polymorphous." Clinical features of this new syndrome are currently being defined. Including the case reported herein, we have found 34 patients with Proteus syndrome described in the English literature. Major clinical findings, defined as those findings seen in more than half of the cases, include hemihypertrophy, macrodactyly, exostoses, epidermal nevi, characteristic cerebriform masses involving the plantar or palmar surfaces, a variety of subcutaneous masses, and scoliosis. Histologic examination of subcutaneous masses has identified a variety of lipomatous, hamartomatous, and angiomatous tumors. 相似文献
52.
Shobha Malviya Frederick A. Burrows Albert E. Johnston Lee N. Benson 《Journal canadien d'anesthésie》1989,36(3):320-324
Anaesthetic and sedation techniques, complications and outcomes were reviewed in 176 children undergoing 184 interventional
cardiologic procedures. Techniques included sedation only, and ketamine, inhalational or narcotic anaesthesia. Ketamine infusion
was the technique most frequently used. Ketamine was associated with a higher incidence of respiratory complications (P <
0.05) than the other techniques. The higher incidence of hypercarbia (15.6 per cent), which did not affect outcome, may be
attributable to the use of supplemental sedatives. The incidence of upper airway obstruction (7.8 per cent) was similar to
that of previous studies. Vascular compromise resulted from the procedure in 33 patients, necessitating surgical correction
in 16. Cardiac perforation occurred in four cases, causing one death. Pulmonary valve stenosis was most amenable to balloon
dilatation and aortic valve stenosis least amenable. Ketamine was the anaesthetic agent preferred by cardiologists for use
in the catheterisation suite when general anaesthesia was required. Vigilant monitoring by anaesthetic staff is necessary
during the procedure, and avoidance of concomitant narcotics is recommended if a ketamine technique with spontaneous ventilation
is used.
Les techniques anesthésiques et de sédation ainsi que les complications et les issues ont été revues chez 176 enfants subissant
184 procedures cardiaques. Les techniques ont inctu soil la sédation seulement, soit l’anesthésie à la kétamine, aux agents
d’inhalation ou aux narcotiques. La perfusion de kétamine était la technique la plus fréquemment utilisée. La ketamine était
associée à une plus grande incidence de complication respiratoire (P < 0.05) comparativement aux autres techniques. La plus
grande incidence d’hypercarbie (15.6 pour cent), n’ayant pas affecté l’issue, pourrait être attribuée à l’utilisation additionnelle
de sédatifs. L’incidence d’obstruction des voies aériennes supérieures (7.8 pour cent) était similaire aux études préalables.
Un problème vasculaire suite à la procédure fut observé chez 33 patients dont 16 ont requis une correction chirurgicale. Une
perforation cardiaque est survenue dans quatre cas provoquant le décès d’un seul patient. La sténose de la valve pulmonaire
était la procédure la plus susceptible d’être dilatée et la sténose de la valve aortique la moins susceptible. La kétamine
était l’agent anesthésique préféré par les cardiologistes lors des cathétérisations quand une anesthésie générate était requise.
Une surveillance vigilante par une équipe anesthésique fut nécessaire durant la procedure. Il faut aussi éviter l’administration
de narcotiques si la kétamine est administrée en respiration spontanée.
Presented in part at the Canadian Anaesthetists’ Society annual meeting in Halifax, June 1988. 相似文献
Presented in part at the Canadian Anaesthetists’ Society annual meeting in Halifax, June 1988. 相似文献
53.
Hormonal fluctuations associated with the menstrual cycle influence
appetite control and eating behaviour. Energy intake varies during the
reproductive cycle in humans and animals, with a periovulatory nadir and a
luteal phase peak. Patterns of macronutrient selection show less
consistency but a number of studies report carbohydrate cravings in the
premenstrual phase, particularly in women with premenstrual syndrome. The
cyclical nature of food cravings are frequently, but not invariably,
associated with depression. Fluctuations in appetite, cravings and energy
intake during the menstrual cycle may occur in parallel with cyclical
rhythms in serotonin, which can be accompanied by affective symptoms. The
premenstrual phase can be considered as a time when women are especially
vulnerable to overconsumption, food craving and depression; this is often
associated with low serotonin activity.
相似文献
54.
55.
56.
Telfer JF; Thomson AJ; Cameron IT; Greer IA; Norman JE 《Human reproduction (Oxford, England)》1997,12(10):2306-2312
Superoxide, an agent which attenuates the half-life of nitric oxide, is
metabolized and synthesized by superoxide dismutase (SOD) and xanthine
oxidase, respectively. Over the last few years much work has focused on the
role of nitric oxide in human parturition. The aim of this study was to
determine whether the onset of human parturition is associated with a
change in the expression of copper/zinc superoxide dismutase (Cu/Zn SOD),
manganese superoxide dismutase (Mn SOD) or xanthine oxidase within the
uterus. Samples of myometrium, placenta, decidua and fetal membranes were
obtained from women before and after the onset of labour at term.
Immunocytochemistry was used to localize Cu/Zn SOD, Mn SOD and xanthine
oxidase and measure SOD enzyme activity. Cu/Zn and Mn SOD-like
immunoreactivity was detected in syncytiotrophoblast cells, villous stromal
cells and endothelial cells of blood vessels in the placenta. In the
myometrium Cu/Zn and Mn SOD were localized to myocytes and endothelial
cells and to some vascular smooth muscle cells. In the fetal membranes we
observed staining for Cu/Zn SOD and Mn SOD in the amnion, chorion,
extravillous trophoblast and decidua. There was no difference in SOD enzyme
activity or staining intensity for SOD between different cell types before
and during labour. Xanthine oxidase immunoreactivity was identified in each
of the tissues examined and again there was no difference in immunostaining
in tissues obtained from women delivered before or after the onset of
labour. These results show that the pregnant uterus is capable of both
synthesizing and degrading superoxide and suggest that superoxide dismutase
and xanthine oxidase may play a role in the maintenance of uterine
quiescence during pregnancy, but not in the initiation of parturition.
相似文献
57.
Keratinocyte growth factor is an important endogenous mediator of hair follicle growth, development, and differentiation. Normalization of the nu/nu follicular differentiation defect and amelioration of chemotherapy-induced alopecia. 总被引:8,自引:5,他引:8
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)
D. M. Danilenko B. D. Ring D. Yanagihara W. Benson B. Wiemann C. O. Starnes G. F. Pierce 《The American journal of pathology》1995,147(1):145-154
The growth and development of hair follicles is influenced by a number of different growth factors and cytokines, particularly members of the fibroblast growth factor (FGF) family. Keratinocyte growth factor (KGF or FGF-7) is a recently identified 28-kd member of the FGF family that induces proliferation of a wide variety of epithelial cells, including keratinocytes within the epidermis and dermal adnexa. Because KGF induces marked proliferation of keratinocytes, and both KGF and KGF receptor (KGFR) mRNA are expressed at high levels in skin, we sought to localize KGF and KGFR in skin by in situ hybridization. KGFR mRNA was relatively strongly expressed by keratinocytes in the basilar epidermis as well as throughout developing hair follicles of rat embryos and neonates. KGF mRNA was expressed at lower levels than was KGFR but could be localized to follicular dermal papillae in rat embryos and neonates. These results prompted us to investigate the effects of KGF on hair follicles in two distinct murine models of alopecia. In the first model, recombinant KGF (rKGF) induced dose-dependent hair growth over most of the body in nu/nu athymic nude mice when administered intraperitoneally or subcutaneously over 17 to 18 days. When administered subcutaneously, rKGF induced the most extensive hair growth at the sites of injection. Histologically, rKGF induced marked follicular and sebaceous gland hypertrophy, a normalization of the nu/nu follicular keratinization defect, and an increase in follicular keratinocyte proliferation as assessed by bromodeoxyuridine labeling. In the second model, a neonatal rat model of cytosine arabinoside chemotherapy-induced alopecia in which interleukin-1, epidermal growth factor, and acidic FGF have all demonstrated some degree of alopecia cytoprotection, rKGF induced a dose-dependent cytoprotective effect, abrogating as much as 50% of the alopecia in this model when administered beginning 1 day before the onset of chemotherapy. Taken together, these data suggest that KGF is an important endogenous mediator of normal hair follicle growth, development, and differentiation. 相似文献
58.
Hydrosalpinges adversely affect markers of endometrial receptivity 总被引:22,自引:10,他引:22
Meyer WR; Castelbaum AJ; Somkuti S; Sagoskin AW; Doyle M; Harris JE; Lessey BA 《Human reproduction (Oxford, England)》1997,12(7):1393-1398
While in-vitro fertilization (IVF) was initially developed in women with
tubal factor infertility, recent clinical studies have suggested that the
presence of hydrosalpinges lowers implantation and pregnancy rates. We
postulated that these hydrosalpinges cause impaired endometrial
receptivity. A total of 103 women with hydrosalpinges were prospectively
evaluated, and compared with 55 infertile and 44 fertile controls. All
women had endometrial biopsies during the window of implantation, analysed
by conventional histological criteria, and also stained for three integrin
markers of endometrial receptivity (alpha1beta1, alpha4beta1 and alpha
vbeta3). Women with hydrosalpinges (cases) expressed significantly less of
the alpha vbeta3 integrin compared with controls. There was no difference
in expression of alpha1beta1 or alpha4beta1 among groups. A significantly
greater number of cases had out of phase histology and missing alpha vbeta3
(type I defects) and absent integrin expression despite normal histological
maturation (type II) defects, compared with controls. Of 20 women with
impaired endometrial receptivity who were also biopsied after hydrosalpinx
surgery, 70% demonstrated increased alpha vbeta3 expression. Seventy-seven
percent of type I and 57% of type II defects were corrected
postoperatively. Using markers of endometrial receptivity, this study
demonstrates that inflammatory hydrosalpinges have an adverse effect on
endometrial receptivity, which in some cases may be overcome by surgical
treatment of the hydrosalpinx.
相似文献
59.
Detection of the apoptosis-suppressing oncoprotein bc1-2 in hormone-refractory human prostate cancers. 总被引:7,自引:10,他引:7
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)
M. Colombel F. Symmans S. Gil K. M. O'Toole D. Chopin M. Benson C. A. Olsson S. Korsmeyer R. Buttyan 《The American journal of pathology》1993,143(2):390-400
The oncoprotein encoded by bc1-2 is unique because of its intracellular location (a mitochondrial membrane protein) and apparent mode of action (suppression of apoptosis). To date, this oncogene has been associated only with the development of certain forms of human B-cell lymphoma. In this report, we describe our experience with a monoclonal antibody made against a synthetic peptide for bc1-2 that can recognize the bc1-2 protein and identify cells in human prostate glands expressing this proto-oncogene with in situ immunohistochemical procedures. These procedures were utilized to survey a series of 62 human tissues to evaluate whether bc1-2 might have a role in the developing prostate gland or in prostate oncogenesis. While all primordial epithelial cells in a fetal prostate gland immunostain for bc1-2, normal and hypertrophic prostate glands of the adult show bc1-2 expression restricted to the basal cells. All epithelial cells in areas of prostatic intraepithelial neoplasia were stained by this antibody, as were most (62%) localized invasive prostatic carcinomas. In contrast, all primary prostatic carcinomas and metastases obtained from metastatic prostate cancer patients after hormone treatment (hormone-refractory tumors) stained positive for bc1-2. This study demonstrates that the oncoprotein encoded by bc1-2 can be detected at sequential stages in the natural history of human prostate cancer. Since the bc1-2 oncoprotein is known to suppress the cellular response to apoptotic stimuli, it will be important to determine whether bc1-2 expression is a factor in the development of prostate cancers and in the survival of hormone-refractory prostate cancer cells. 相似文献
60.