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排序方式: 共有7336条查询结果,搜索用时 12 毫秒
51.
The effect of hyperbaric oxygen on medial collateral ligament healing in a rat model 总被引:1,自引:0,他引:1
Horn PC Webster DA Amin HM Mascia MF Werner FW Fortino MD 《Clinical orthopaedics and related research》1999,(360):238-242
Hyperbaric oxygen has been shown to promote healing in bone and some soft tissues. This study was undertaken to determine its effect on ligamentous healing. Forty-eight Sprague-Dawley rats underwent a standardized surgical laceration of the right (divided) medial collateral ligament, whereas the left (undivided) medial collateral ligament was not surgically lacerated. A control group of 24 rats recovered without intervention. An experimental group consisting of the other 24 rats was exposed to hyperbaric oxygen at 2.8 atmospheres for 1.5 hours a day for 5 days after the surgery. Six rats from each group were euthanized at 2, 4, 6, and 8 weeks. The stiffness and final force to failure were recorded for the divided and undivided medial collateral ligaments. At 4 weeks, a statistically greater force was required to cause failure of the previously divided ligaments that had been exposed to hyperbaric oxygen than those that had not. The stiffness and force to cause failure of previously divided ligaments were statistically greater at 4 weeks than at 2 weeks, whether or not hyperbaric oxygen was used. No additional statistical increases in stiffness or force were observed at 6 weeks. 相似文献
52.
Amin MB de Peralta-Venturina MN Ro JY El-Naggar A Mackay B Ordonez N Mani A Ayala A 《The American journal of surgical pathology》1999,23(12):1455-1463
Clear cell sarcoma of the kidney is a distinct, highly malignant pediatric neoplasm. Its occurrence in adults is extremely rare and the subject of isolated case reports. We present a series of four cases (three males and one female) identified in an adolescent and in young adults (16, 18, 20, and 25 years) with flank mass (three cases), hematuria (two cases), flank pain (two cases), and hypertension (one case). Three patients had stage III disease and one had stage I disease (National Wilms' Tumor Study staging system). All tumors had predominantly or exclusively the classic histology of a monotonous proliferation of uniform small round cells with evenly distributed fine chromatin, although focal microcyst formation (two cases) and spindled architecture (one case) (variant patterns) were also noted. Therapy in all cases consisted of surgery and chemotherapy with or without radiation. Follow-up data (29-202 months) showed distant metastases in all four cases, including the lung (four cases), bone (two cases), and the liver (two cases). Three patients died of disease at 29, 59, and 63 months (mean, 50.3 months), and one patient is alive with no evidence of disease at 202 months. Ultrastructural features included scattered primitive junctions, short and irregular cytoplasmic extensions, and scant to a moderate amount of mitochondria. Immunohistochemical study (three cases) showed immunoreactivity with vimentin (two cases) and no reaction with cytokeratin, epithelial membrane antigen, S-100 protein, or desmin. Flow cytometric analysis showed diploid DNA content in three primary tumors and tetraploidy in one metastatic tumor. The proliferative activity (S-phase fraction) was low to intermediate (mean, 9.8%). Our data suggest that clear cell sarcoma of the kidney in the young adult age group resembles its pediatric counterpart in ultrastructural and immunohistochemical characteristics, proclivity for skeletal and visceral metastasis, DNA diploid status with relatively low S-phase, and aggressive clinical course. Clear cell sarcoma of the kidney in adult patients, although rare, must be differentiated from sarcomatoid carcinoma, sarcomas, and round cell tumors because of its unique characteristics in comparison to other renal neoplasms. 相似文献
53.
A single hydrophobic residue confers barbiturate sensitivity to gamma-aminobutyric acid type C receptor 总被引:2,自引:0,他引:2
Amin J 《Molecular pharmacology》1999,55(3):411-423
Barbiturate sensitivity was imparted to the human rho1 homooligomeric gamma-aminobutyric acid (GABA) receptor channel by mutation of a tryptophan residue at position 328 (Trp328), which is located within the third transmembrane domain. Substitutions of Trp328 with a spectrum of amino acids revealed that nearly all hydrophobic residues produced receptor channels that were both directly activated and modulated by pentobarbital with similar sensitivities. Previous studies with ligand-gated ion channels (including GABA) have demonstrated that even conservative amino acid substitution within the agonist-dependent activation domain (N-terminal extracellular domain) can markedly impair agonist sensitivity. Thus, the lack of significant variation in pentobarbital sensitivity among the Trp328 mutants attests to an intrinsic difference between pentobarbital- and the GABA-dependent activation domain. Compared with the heterooligomeric alphabetagamma receptor channel, the mode of modulation for homooligomeric Trp328 mutants by pentobarbital was more dependent on the GABA concentration, yielding potentiation only at low concentrations of GABA (fractions of their respective EC50 values), yet causing inhibition at higher concentrations. Agonist-related studies have also demonstrated that residue 328 plays an important role in agonist-dependent activation, suggesting a functional interconnection between the GABA and pentobarbital activation domains. 相似文献
54.
Nadkarni JJ Perambakam SM Rathore VB Amin KM Parikh PM Naresh KN Advani SH 《Cancer biotherapy & radiopharmaceuticals》1998,13(4):269-274
The trafficking or homing of different lymphoid subsets to particular microenvironment is mediated by specific cell adhesion molecules (CAMs) expressed on lymphocytes and endothelial cells. B-cell chronic lymphocytic leukaemia (B-CLL) or Non-Hodgkin's lymphoma of small lymphocytic, B-cell type are monoclonal expansions of mature lymphocytes. The relative distribution of the tumor lymphocytes among various lymphoid compartments vary from patient to patient. Very few studies underlying this issue are available. To this effect, we have analysed the expression of LFA-1; VLA-4, ICAM-1; CD44H and CD44v6 (haematopoietic and variant form respectively) on freshly isolated lymphocytes obtained from bone marrow (BM), peripheral blood (PB) and lymph node (LN) by flow cytometry. Overall, we find strong expression of CD44H, low to moderate expression of LFA-1, negative to low expression of VLA-4 and lack of expression of CD44v6. ICAM-1 expression was observed only in patients with prominent lymphadenopathy. Higher expression of CD44H in PB lymphoid cells relative to that of BM lymphoid cells correlated with higher PB lymphocytosis (p < 0.001). Proliferating cell nuclear antigen expression in LN sections correlated inversely with VLA-4 expression on BM and PB lymphoid cells (p < 0.05). There was no significant correlation between expression of CAMs and bcl-2 protein. 相似文献
55.
E M Sadeghi L L Weldon P H Kwon E Sampson 《International journal of oral and maxillofacial surgery》1991,20(3):142-143
This unusual cystic lesion was previously described as a lesion that has features of both botryoid odontogenic cyst and mucoepidermoid tumor and later was named as glandular odontogenic cyst. An additional case is reported and its clinicopathologic features described. The name "mucoepidermoid odontogenic cyst" is proposed. 相似文献
56.
Brainstem maturation after antenatal steroids exposure in premature infants as evaluated by auditory brainstem-evoked response. 总被引:2,自引:0,他引:2
Sanjiv B Amin Mark S Orlando Larry E Dalzell Kathleen S Merle Ronnie Guillet 《Journal of perinatology》2003,23(4):307-311
OBJECTIVE: Antenatal steroids result in fetal lung maturation, but may retard brain development. Auditory brainstem-evoked response (ABR) is a noninvasive assessment of brainstem maturation. The objective of this study was to determine if antenatal steroids affect brainstem maturation in infants =32 weeks gestational age (GA). DESIGN/METHODS: Bilateral monaural ABR were performed within the first 24 hours using 80 db nHL unfiltered click stimuli at a repetition rate of 39.9/seconds. ABR waveforms were categorized into Response Types based on response replicability and peak identification. Absolute wave latencies and interpeak latencies were measured when applicable. Data were collected for antenatal steroid exposure, mode of delivery, chorioamnionitis in utero, exposure to illicit drugs, exposure to magnesium sulfate, mechanical ventilation and 5 minute Apgar score <5 minute. Infants with TORCH infections, unstable conditions, and chromosomal disorders were excluded. RESULTS: Of 186 infants studied, 130 received antenatal steroids. Data were analyzed in 2 week GA intervals. There was a significant difference (P<0.05) in race (29 vs 39% African-American), birth weight (1231 vs 1416 gm) and use of magnesium sulfate (60 vs 32%) among infants who did and did not receive antenatal steroids, respectively. There was no significant difference in the other parameters measured. Even after controlling for confounding variables, there was no difference between absolute wave latencies or interpeak latencies between groups at either 28 to 29 weeks' or 30 to 31 weeks' postmenstrual age. There was no significant difference in frequency distribution of ABR waveform Response Types between groups. CONCLUSIONS: Antenatal steroids have neither a deleterious nor beneficial effect on brainstem maturation as measured by ABR in infants at =32 weeks GA. 相似文献
57.
BACKGROUND: Growing skull fractures rarely develop in the skull base region. To the best of our knowledge, only two similar cases have been reported in the English literature. This rare complication, which can occur even after a mild head injury, can produce exophthalmos and threaten the vision. METHODS: The clinical and radiological findings of expanding leptomeningeal cysts extending into the orbit in nine patients referred to the department of Neurosurgery are presented. After appropriate investigations confirming the presence of the expansile retroglobal lesion, surgical exploration was performed via fronto-lateral or the preferred fronto-basal approach. The variable findings are denoted and the relevant literature is also reviewed. RESULTS: Frontobasal head injuries play an important role in pathogenesis of these traumatic expansile leptomeningeal cysts. In this series of nine young girls, 6.65% (six out of nine) injuries happened in the first decade of life with an interval of 2 to 12 months (mean = 6.7, SD = 9.7). High-resolution coronal view computed tomography (CT) scanning with bone density window images, and high intensity cystic lesions visible on T2-weighted coronal MR images were diagnostic clues. CONCLUSIONS: Growing fractures of the anterior skull base may complicate the natural course of healing of any minor frontobasal head injury, especially during childhood. Good quality imaging is mandatory in cases of progressive unilateral exophthalmos. Proper surgical intervention will lead to a good cosmetic result. 相似文献
58.
Philip AT Amin MB Tamboli P Lee TJ Hill CE Ro JY 《The American journal of surgical pathology》2000,24(9):1286-1290
Accurate pathologic staging of carcinomas of the urinary bladder involves assessment of invasion by the tumor into the bladder wall and beyond into perivesical soft tissue. The presence of tumor within perivesical soft tissue implies pathologic stage pT3 (AJCC/UICC system, 1997). In traditional textbooks of histology, anatomy, pathology, and in the literature, other than a single case report and a brief reference in another paper, there is no information on the presence of adipose tissue in the lamina propria or muscularis propria of the urinary bladder. Nine hundred forty-three sections from 139 cystectomy specimens were evaluated for the presence, location, and quantity of adipose tissue within the lamina propria and muscularis propria. The histology of the perivesical soft tissues and the nature of its delineation from muscularis propria were also analyzed. Adipose tissue was seen within the lamina propria in 53% (74 of 139) of cystectomies and in 17.6% (166 of 943) of the examined sections. It was located predominantly in the deep lamina propria (at or below the muscularis mucosae) in 81.1% (60 of 74) of the cystectomies and in 91% (151 of 166) of the sections. Within the lamina propria it was predominantly seen as small localized aggregates in 92% (153 of 166) of sections. All cases showed adipose tissue within the muscularis propria. Adipose tissue was identified within the superficial (inner) muscularis propria in 54% (512 of 943) of sections and was predominantly in small aggregates in 80.5% (412 of 512) of sections. It was in moderate to abundant quantities within the deep (outer) muscularis propria in 60.7% (572 of 943) of sections. The perivesical soft tissue was almost exclusively composed of adipose tissue with variable vascularity. Delineation of the perivesical adipose tissue from the deep (outer) muscularis propria was typically indistinct because muscle bundles of the latter haphazardly merged with the perivesical adipose tissue. Based on these findings, we conclude that adipose tissue is frequently present in the lamina propria and muscularis propria of the urinary bladder wall, and is usually scant in the former location and frequently abundant in the latter. Awareness of the high frequency of adipose tissue within the urinary bladder wall has prognostic and therapeutic implications. In transurethral resection of bladder tumor (TURBT) specimens, misinterpretation of tumor infiltrating adipose tissue within lamina propria (pT1) as perivesical soft tissue involvement (pT3) may potentially result in unwarranted aggressive management. Substaging of muscle invasive tumors should be performed in cystectomy specimens only, because the junction of muscularis propria and the perivesical adipose tissue is typically ill-defined. Muscularis propria adipose tissue in TURBT specimens may be erroneously assumed to be perivesical adipose tissue, potentially leading to overstaging of the primary tumor. 相似文献
59.
We compared the tumor-initiating activities toward mouse skin of two
structurally related polycyclic aromatic hydrocarbon diol epoxides: racemic
anti-1,2,3,4-tetrahydro-5,6-dimethylchrysene-1,2-diol-3,4- epoxide
(5,6-diMeCDE) and racemic anti-1,2,3,4-tetrahydro-5-
methylchrysene-1,2-diol-3,4-epoxide (5-MeCDE). Tumors induced by these diol
epoxides were analysed for mutations in the Ha-ras gene. 5,6- diMeCDE is
derived from the non-planar parent compound 5,6- dimethylchrysene, and
reacts to approximately equal extents with dA and dG in DNA, whereas
5-MeCDE is derived from a nearly planar parent compound, 5-methylchrysene,
and reacts mainly with dG in DNA. 5,6- diMeCDE, at initiating doses of 33,
100 or 400 nmol per mouse, induced 1.2, 2.2 and 6.2 skin tumors per mouse,
respectively. It was significantly less tumorigenic than 5-MeCDE which
induced 3.1, 7.5 and 9.1 skin tumors per mouse at the same doses. Tumors
induced by 5,6- diMeCDE had a large number of CAA-->CTA mutations in
codon 61 of the Ha- ras gene: 50, 55 and 75% of the tumors analysed had
this mutation at the 33, 100 and 400 nmol doses. No mutations were found in
codons 12 and 13 in the tumors induced by 5,6-diMeCDE. In contrast,
CAA-->CTA mutations in codon 61 were rarely seen in tumors induced by
5-MeCDE. At the highest dose of 5-MeCDE, 20% of the tumors analysed had
mutations at G of codons 12 and 13. The results of this comparative study
support the hypothesis that mutations in the Ha-ras gene in mouse skin
tumors induced by PAH diol epoxides occur as a result of their direct
reaction with the gene. However, pathways other than the commonly observed
Ha- ras codon 61 mutations are clearly important in mouse skin
tumorigenesis by these diol epoxides.
相似文献
60.
Sadeghi H Allard P Shafie K Mathieu PA Sadeghi S Prince F Ramsay J 《Gait & posture》2000,12(3):257-264
Timing in peak gait values shifts slightly between gait trials. When averaged, the standard deviation (S.D.) in gait data may increase due to this inter-trial variability unless normalization is carried out beforehand. The objective of this study was to determine how curve registration, an alignment technique, can reduce inter-subject variability in gait data without perturbing the curve characteristics. Twenty young, healthy men participated in this study each providing a single gait trial. Gait was assessed by means of a four-camera high-speed video system synchronized to a force plate. A rigid body three-segment model was used in an inverse dynamic approach to calculate three-dimensional muscle powers at the hip, knee and ankle. Curve registration was applied to each of the 20 gait trials to align the peak powers. The mean registered peak powers increased by an average of 0.10±0.13 W/kg with the highest increases in the sagittal plane at push-off. After performing curve registration, the RMS values decreased by 13.6% and the greatest reduction occurred at the hip and knee, both in the sagittal plane. No important discontinuities were reported in the first and second derivatives of the unregistered and registered curves. Curve registration did not have much effect on the harmonic content. This would be an appropriate technique for application prior to any statistical analysis using able-bodied gait patterns. 相似文献