全文获取类型
收费全文 | 10027篇 |
免费 | 537篇 |
国内免费 | 114篇 |
专业分类
耳鼻咽喉 | 264篇 |
儿科学 | 384篇 |
妇产科学 | 74篇 |
基础医学 | 1025篇 |
口腔科学 | 195篇 |
临床医学 | 1365篇 |
内科学 | 962篇 |
皮肤病学 | 36篇 |
神经病学 | 1557篇 |
特种医学 | 443篇 |
外科学 | 918篇 |
综合类 | 897篇 |
一般理论 | 1篇 |
预防医学 | 772篇 |
眼科学 | 451篇 |
药学 | 777篇 |
4篇 | |
中国医学 | 182篇 |
肿瘤学 | 371篇 |
出版年
2023年 | 149篇 |
2022年 | 328篇 |
2021年 | 404篇 |
2020年 | 343篇 |
2019年 | 366篇 |
2018年 | 378篇 |
2017年 | 336篇 |
2016年 | 316篇 |
2015年 | 339篇 |
2014年 | 705篇 |
2013年 | 666篇 |
2012年 | 565篇 |
2011年 | 645篇 |
2010年 | 487篇 |
2009年 | 466篇 |
2008年 | 470篇 |
2007年 | 375篇 |
2006年 | 319篇 |
2005年 | 259篇 |
2004年 | 257篇 |
2003年 | 208篇 |
2002年 | 157篇 |
2001年 | 163篇 |
2000年 | 143篇 |
1999年 | 116篇 |
1998年 | 118篇 |
1997年 | 112篇 |
1996年 | 101篇 |
1995年 | 92篇 |
1994年 | 87篇 |
1993年 | 78篇 |
1992年 | 83篇 |
1991年 | 67篇 |
1990年 | 61篇 |
1989年 | 52篇 |
1988年 | 75篇 |
1987年 | 55篇 |
1986年 | 53篇 |
1985年 | 87篇 |
1984年 | 74篇 |
1983年 | 62篇 |
1982年 | 55篇 |
1981年 | 61篇 |
1980年 | 55篇 |
1979年 | 48篇 |
1978年 | 41篇 |
1977年 | 38篇 |
1976年 | 45篇 |
1975年 | 25篇 |
1973年 | 24篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
人胎儿中枢神经系统星形胶质细胞形态发育的观察 总被引:4,自引:0,他引:4
为观察人胎儿中枢神经系统星形胶质细胞形态发育。用胶质原纤维酸性蛋白抗体进行免疫组织化学染色。结果表明;1.以颈段脊髓,脑干,海马和小脑蚓部于胚胎25周其GFAP染色强度,细胞密度接近出生时水平。而此时期大脑皮层Ast密度约为出生时的四分之一。2.在同一胎龄CNS的不同部位,GFAP阳性Ast分布不均匀。3.Ast不仅在毛细胞血管周围,而且在小血管周围密度大染色深,环绕血管呈辐射状排列。 相似文献
62.
《Acta histochemica》2022,124(4):151895
Cancer is a disease characterised by abnormal cell growth that can invade or spread to other regions of the body. Organoids are three-dimensional ex vivo tissue cultures made from embryonic stem cells, induced pluripotent stem cells, progenitor cells or tissue that serve as a physiological model for cancer research. These are designed to recapitulate the in vivo properties of tumours. Importantly, effective recapitulation of the structure of tissues and function is believed to predict patient response, allowing for the creation of personalised therapy in a timely manner that may be used in the clinic. This Review discusses the pre-clinical model and different types of human organoids as models for the development of high throughput drug screening and also aims to highlight how organoids are shaping the future of cancer research. 相似文献
63.
Central amygdaloid nucleus lesions in rats had no effect on recovery of preoperative body weight and food consumption levels. The brain damaged rats also recovered preoperative levels of water consumption as rapidly as control rats but then developed a mild but persistent hypodipsia. The experimental rats also drank less than control rats when food deprived and showed marginally reliable decreases in 0.1% quinine solution consumption and latency to consume a novel food. There was no detectable lesion effect on 0.1% saccharin solution consumption, exploration of a novel environment or formation of a learned taste aversion. It is suggested that the central amygdaloid nucleus has a role in mediating the relationship between food and water intake and in some taste mediated consummatory behavior. 相似文献
64.
65.
The use of neuronal nuclear antigen (NeuN) as a reliable neuronal marker in the differential diagnosis of clear cell neoplasms of the central nervous system was determined in a biopsy series of 23 cases. Immunohistochemical analyses were carried out by antisera against neuronal nuclear antigen, synaptophysin, neuron-specific enolase, microtubule-associated protein 2, and glial fibrillary acidic protein. All eight central neurocytomas were characteristically immunolabeled by NeuN. NeuN immunoreactivity was uniformly strong and basically located in the nuclei of neurocytes. Despite this uniform staining pattern of central neurocytomas, 12 cases of oligodendrogliomas and three cases of ependymoma were negative for NeuN. As the diagnostic criteria for central neurocytoma include immunohistochemical and/or ultrastructural evidence for neuronal differentiation, NeuN as a sensitive and specific neuronal marker in formalin-fixed, paraffin-embedded tissues may greatly facilitate the differential diagnosis of central neurocytomas. 相似文献
66.
Alyce C. Russell Agnieszka Kepka Irena Trbojević-Akmačić Ivo Ugrina Manshu Song Jennie Hui Michael Hunter Simon M. Laws Gordan Lauc Wei Wang 《Immunobiology》2019,224(1):110-115
Background
Increased body fat may be associated with an increased risk of developing an underlying pro-inflammatory state, thus leading to greater risk of developing certain chronic conditions. Immunoglobulin G has the ability to exert both anti- and pro-inflammatory effects, and the N-glycosylation of the fragment crystallisable portion is involved in mediating this process. Body mass index, a rudimentary yet gold standard indication for body fat, has been shown to be associated with agalactosylated immunoglobulin G N-glycans.Aim
We aimed to determine the association between increased body fat and the immunoglobulin G glycosylation features, comparing body mass index to other measures of body fat distribution.Methods
We investigated a sample of 637 community-based 45–69?year olds, with mixed phenotypes, residing in Busselton, Western Australia. Body mass index and the waist-to-hip and waist-to-height ratios were calculated using anthropometry, while dual-energy x-ray absorptiometry was performed to gain an accurate measure of total and area specific body fat. Serum immunoglobulin GN-glycans were analysed by ultra-performance liquid chromatography.Results
Twenty-two N-glycan peaks were found to be associated with at least one of the fat measures. While the previous association of body mass index to agalactosylated immunoglobulin G was replicated, measures of central adiposity explained the most variation in the immunoglobulin G glycome.Conclusion
Central adiposity is associated with an increased pro-inflammatory fraction of immunoglobulin G, suggesting that the android/gynoid ratio or waist-to-height ratio instead be considered when controlling for adiposity in immunoglobulin G glycome biomarker studies. 相似文献67.
Grazyna Perko Jes F. Schmidt Jorgen Warberg Niels H. Secher 《European journal of applied physiology》1996,73(5):459-464
To evaluate influences on blood volume distribution, atrial natriuretic peptide concentrations (ANP) and thoracic and leg electrical impedance at 2.5 (TI2.5 and LI2.5, respectively) and 100 kHz (TI100 and LI100, respectively) were monitored during administration of ketanserin, noradrenaline and trimetaphan combined with lower body negative pressure (LBNP) in 12 subjects. Administration of clinically relevant doses of ketanserin alone did not induce changes in mean arterial pressure (MAP) or in the central blood volume, as electrical impedance and ANP concentrations did not change. During continued infusion of ketanserin an increase in MAP from a mean of 90 (range 83–108) to 113 (range 98–138) mmHg was induced by noradrenaline, but TI2.5 [mean 45.6 (range 39.3–54.2)] and TI100 [mean 33.8 (range 27.5–38.5) ] remainded stable until ganglionic blockade and LBNP were applied, when they increased by a mean of 3.1 (range 2.0–6.1) and 2.7 (range 1.1–4.2) , respectively (P < 0.05). Conversely, LI2.5 [mean 79.6 (range 74.1–89.4)] and LI100 [mean 56.7 (range 52.4–63.3) ] decreased by a mean of 3.2 (range 1.2–8.0) and 2.3 (range 0.9–3.9) ANP from a mean of 27.7 (range 10.2–62.7) to 12.7 (range 7.1–27.5) pmol· 1–1 and MAP fell to a mean of 62 (range 42–70) mmHg (P < 0.05). The heart rate was a mean of 75 (range 69–77) beats -min-' and did not change until LBNP, when it increased to a mean of 102 (range 78–104) beats · min–1, as presyncopal symptoms appeared. The data indicated that serotonergic blockade by ketanserin and -sympathetic stimulation by noradrenaline did not affect blood volume distribution in normal humans, but that ganglionic blockade combined with LBNP reduced the central blood volume as leg volume increased; during central hypovolaemia tachycardia induced by ganglionic blockade did not prevent the fall in MAP, and thereby the appearance of presyncopal symptoms. 相似文献
68.
M. Deckert-Schlüter Josef Marek Michael Šetlík Jana Marková E. Pakos Robert Fischer Otmar D. Wiestler 《Virchows Archiv : an international journal of pathology》1998,432(5):477-481
A 62-year-old woman presented with loss of memory and a mild hemiparesis. Neuroradiology demonstrated a left frontoparietal
tumour. Biopsy specimens of this lesion revealed intracerebral Hodgkin’s lymphoma, a diagnosis supported by immunohistochemical
reactions of the tumour cells for the CD30 antigen. Additional cell cycle studies revealed a high proliferative activity of
the tumour cells in association with absence of apoptosis. There was no evidence that overexpression of bcl-2 or Epstein-Barr
virus infection was involved in the pathogenesis of this neoplasm. Lymphomas in the lung were detected 3 months later. Following
neurosurgical excision, radiotherapy, and chemotherapy, the patient had no evidence of Hodgkin’s disease after 13 months of
follow-up.
Received: 8 October 1997 / Accepted: 8 December 1997 相似文献
69.
M. A. Livesley S. E. Tebbs H. A. Moss M. H. Faroqui P. A. Lambert T. S. J. Elliott 《European journal of clinical microbiology & infectious diseases》1998,17(2):108-112
Microorganisms detected in situ on the distal tip of central venous catheters (CVC) within 90 min of insertion were investigated using pulsed-field gel electrophoresis to analyse genomic fragments obtained with theSmaI restriction enzyme. Thirty patients received a triple lumen CVC, which was inserted directly through the skin using the Seldinger technique. In a further 30 patients a triple lumen CVC was inserted through a Swan sheath, thereby avoiding direct contact of the CVC with the skin. Staphylococci were isolated from the distal tips of the catheters in 6 patients (5 who had the CVC inserted directly through the skin and 1 who had the CVC inserted via a Swan sheath.) Twenty-three staphylococcal isolates were also isolated from the insertion equipment and the skin swabs surrounding the insertion site of these six patients. All the isolates were genotyped. In one of the patients the organisms isolated from the skin were identical to those on the CVC tip. In two further patients similar organisms were isolated from the insertion equipment and the patients' skin. These results, in addition to the reduced colonisation rates observed when catheters were introduced through a Swan sheath, support the hypothesis that microorganisms from the skin are impacted onto the CVC tip and the CVC insertion equipment at catheter insertion. 相似文献
70.
E. Challet D. Miceli J. Pierre J. Repérant G. Masicotte M. Herbin N. P. Vesselkin 《Anatomy and embryology》1996,193(3):209-227
The distribution of serotonin (5-HT)-containing perikarya, fibers and terminals in the brain of the pigeon (Columba livia) was investigated, using immunohistochemical and immunofluorescence methods combined with retrograde axonal transport. Twenty-one different groups of 5-HT immunoreactive (IR) cells were identified, 2 of which were localized at the hypothalamic level (periventricular organ, infundibular recess) and 19 at the tegmental-mesencephalic and rhombencephalic levels. Ten of the cell groups were situated within the region of the midline from the isthmic to the posterior rhombencephalic level and constituted the raphe system (nucleus annularis, decussatio brachium conjunctivum, area ventralis, external border of the nucleus interpeduncularis, zona peri-nervus oculomotorius, zona perifasciculus longitudinalis medialis, zona inter-flm, nucleus linearis caudalis, nucleus raphe superior pars ventralis, nucleus raphe inferior). The 9 other cell populations belonged to the lateral group and extended from the posterior mesencephalic tegmentum to the caudal rhombencephalon [formatio reticularis mesencephali, nucleus ventrolateralis tegmenti, ectopic area (Ec) of the nucleus isthmo-opticus (NIO), nucleus subceruleus, nucleus ceruleus, nucleus reticularis pontis caudalis, nucleus vestibularis medialis, nucleus reticularis parvocellularis and nucleus reticularis magnocellularis]. Combining the retrograde axonal transport of rhodamine -isothiocyanate (RITC) after intraocular injection and immunohistofluorescence (fluoresceine isothiocyanate: FITC/5-HT) showed the centrifugal neurons (NIO, ec) to be immunonegative. Serotonin-IR fibers and terminals were found to be very broadly distributed within the brain and were particularly prominent in several structures of the telencephalon (archistriatum pars dorsalis, nucleus taeniae, area parahippocampalis, septum), diencephalon (nuclei preopticus medianus, magnocellularis, nucleus geniculatus lateralis pars ventralis, nucleus triangularis, nucleus pretectalis), mesencephalon-rhombencephalon (superficial layers of the optic tectum, nucleus ectomamillaris, nucleus isthmo-opticus and in most of the cranial nerve nuclei). Comparing the present results with those of previous studies in birds suggests some major serotonin containing pathways in the avian brain and clarifies the possible origin of the serotonin innervation of some parts of the brain. Moreover, comparing our results in birds with those obtained in other vertebrate species shows that the organization of the serotoninergic system in many regions of the avian brain is much like that found in reptiles and mammals.Abbreviations
Ad
Archistriatum pars dorsalis
-
alp
area interpeduncularis
-
al
ansa lenticularis
-
Ann
nucleus annularis
-
APH
area parahippocampalis
-
Av
archistriatum pars ventralis
-
AVT
area ventralis (Tsai)
-
bcd
brachium conjunctivum descendens
-
BO
bulbus olfactorius
-
ca
commisssura anterior
-
CDL
area corticoidea dorsolateralis
-
Cer
cerebellum
-
cf
fiber layer of the olfactory bulb
-
cg
granular cell layer of the olfactory bulb
-
co
chiasma opticum
-
ct
commissura tectalis
-
dbc
decussatio brachiorum conjunctivorum
-
DL
nucleus dorsolateralis anterior thalami
-
DLP
nucleus dorsolateralis posterior thalami
-
DM
nucleus dorsomedialis thalami
-
dnt
decussatio nervi trochlearis
-
E
ectostriatum
-
Ec
ectopic area of the nucleus isthmo-opticus
-
EM
nucleus ectomamillaris
-
flm
fasciculus longitudinalis medialis
-
fpl
fasciculus prosencephali lateralis
-
FRL
formatio reticularis lateralis mesencephali
-
FRM
formatio reticularis medialis mesencephali
-
fu
fasciculus uncinatus
-
GCt
substantia grisea centralis
-
GLv
nucleus geniculatus lateralis pars ventralis
-
gr
granular cell layer of the cerebellum
-
HA
hyperstriatum accessorium
-
HD
hyperstriatum dorsale
-
HIS
hyperstriatum intercalatus superior
-
HL
nucleus habenularis lateralis
-
HM
nucleus habenularis medialis
-
Hp
hippocampus
-
HV
hyperstriatum ventrale
-
ICo
nucleus intercollicularis
-
i-flm
inter fasciculus longitudinalis medialis
-
Imc
nucleus ishmi pars magnocellularis
-
Ip
nucleus interpeduncularis
-
Ipc
nucleus isthmi pars parvocellularis
-
LA
nucleus lateralis anterior thalami
-
La
nucleus laminaris
-
LC
nucleus linearis caudalis
-
LHy
nucleus lateralis hypothalami
-
lm
lemniscus medialis
-
LoC
locus coeruleus
-
LPO
lobus paraolfactorius
-
ls
lemniscus spinalis
-
MLd
nucleus mesencephalicus lateralis pars dorsalis
-
mo
molecular layer of the cerebellum
-
MoV
nucleus motorius nervi trigemini
-
Mp
magnocellularis preopticus
-
N
neostriatum
-
NIII
nucleus nervi oculomotorii
-
nIII
nervus oculomotorius
-
NIV
nucleus nervi trochlearis
-
NV nucleus nervi trigemini
nV nervus trigeminus
-
NVII
nucleus nervifacialis
-
nVIII
nervus octavus
-
NIO
nucleus isthmo-opticus
-
om
tractus occipitomesencephalicus
-
OPH
hypothalamic periventricular organ
-
Os
nucleus olivaris superior
-
Ov
nucleus ovoidalis
-
PA
paleostriatum augmentatum
-
Po
nucleus pontis
-
POM
nucleus preoticus medialis
-
PP
paleostriatum primitivum
-
PrV
nucleus sensorius principalis nervi trigemini
-
PT
nucleus pretectalis
-
pu
Purkinje cell layer
-
qf
tractus quintofrontalis
-
Rai
nucleus raphe inferior
-
RasV
nucleus raphe superior pars ventralis
-
ReI
recessus infundibularis
-
Rm
nucleus reticularis magnocellularis
-
Rp
nucleus reticularis parvocellularis
-
RPc
nucleus reticularis pontis caudalis
-
RPO
nucleus reticularis pontis oralis
-
Rt
nucleus rotundus
-
Ru
nucleus ruber
-
S
septum
-
Sac
stratum album centrale
-
SCH
stratum cellulare hypothalami
-
Sgc
stratum griseum centrale
-
Sgf
stratum griseum et fibrosum superficiale
-
Sgfp
stratum griseum et fibrosum periventriculare
-
Sop
stratum opticum
-
SP
nucleus subpretectalis
-
SPC
nucleus superficialis parvocellularis
-
Spl
nucleus spiriformis lateralis
-
Spm
nucleus spiriformis medialis
-
SRt
nucleus subrotundus
-
SuC
nucleus subcoeruleus
-
to
tractus opticus
-
Tn
nucleus taeniae
-
TPc
nucleus tegmenti pedunculo-pontinus pars compacta
-
Tr
nucleus triangularis
-
tsm
tractus septomesencephalicus
-
ttd
nucleus et tractus descendens nervi trigemini
-
Tu
nucleus tuberis
-
Vel
nucleus vestibularis lateralis
-
Vem
nucleus vestibularis medialis
-
Vlt
nucleus ventrolateralis thalami
-
VT
nucleus ventrolateralis tegmenti
-
Zp-flm
zona perifasciculus longitudinalis medialis
-
Zp-NIII
zona perinervus oculomotorius 相似文献