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991.
Proteus syndrome is a complex hamartomatous disorder characterized by asymmetrical gigantism, epidermal nevi, vascular malformations, hamartomas, lipomas, and hyperostosis. Since the syndrome was first described, many hypotheses have been proposed to explain its occurrence. The most plausible is Happle's somatic mosaic hypothesis, but no somatic mutations in candidate genes have been reported to be clearly involved in Proteus syndrome. However, germ-line PTEN mutations have been reported in patients with Proteus and in "Proteus-like disorders." Other studies of patients with Proteus syndrome have not supported these findings. In this study, affected and unaffected tissue from six patients diagnosed with Proteus syndrome were screened by direct sequencing of genomic DNA to determine if there might be an association between germ-line or somatic mutations in PTEN or GPC3 and the development of Proteus syndrome. No intra-exonic mutations were identified, indicating that neither PTEN nor GPC3 are likely to have major roles in the etiology of Proteus syndrome in our series of patients.  相似文献   
992.
Diurnal and nocturnal species are profoundly different in terms of the temporal organization of daily rhythms in physiology and behavior. The neural bases for these divergent patterns are at present unknown. Here we examine functional differences in the suprachiasmatic nucleus (SCN) and one of its primary targets in a diurnal rodent, the unstriped Nile grass rat (Arvicanthis niloticus) and in a nocturnal one, the laboratory rat (Rattus norvegicus). Grass rats and laboratory rats were housed in a 12:12 light:dark cycle, and killed at six time points. cFos-immunoreactive rhythms in the SCN of grass rats and laboratory rats were similar to those reported previously, with peaks early in the light phase and troughs in the dark phase. However, cFos-immunoreactivity in the lower subparaventricular zone (LSPV) of grass rats rose sharply 5 h into the dark phase, and remained high through the first hour after light onset, whereas in laboratory rats it peaked 1 h after light onset and was low at all other sampling times. Daily cFos rhythms in both the SCN and the LSPV persisted in grass rats, but not in laboratory rats, after extended periods in constant darkness. In grass rats, the endogenous cFos rhythm in the LSPV, but not the SCN, was present both in calbindin-positive and in calbindin-negative cells. Cells that expressed cFos at night in the region of the LSPV in grass rats were clearly outside of the boundaries of the SCN as delineated by Nissl stain and immunoreactivity for vasopressin and vasoactive intestinal peptide. The LSPV of the grass rat, a region that receives substantial input from the SCN, displays a daily rhythm in cFos expression that differs from that of laboratory rats with respect to its rising phase, the duration of the peak and its dependence on a light/dark cycle. These characteristics may reflect the existence of mechanisms in the LSPV that enable it to modulate efferent SCN signals differently in diurnal and nocturnal species.  相似文献   
993.
994.
Patients with mild Alzheimer's disease (AD) were compared with age-matched control subjects on an associative recognition task. Subjects studied pairs of unrelated words and were later asked to distinguish between these same studied pairs (intact) and new pairs that contained either rearranged studied words (rearranged) or non-studied words (non-studied). Studied pairs were presented either once or 3 times. Repetition increased hits to intact pairs in both groups, but repetition increased false alarms to rearranged pairs only in patients. This latter pattern indicates that repetition increased familiarity of the rearranged pairs, but only the control subjects were able to counter this familiarity by recalling the originally studied pairs (a recall-to-reject process). AD impaired this recall-to-reject process, leading to more familiarity based false alarms. These data support the idea that recollection-based monitoring processes are impaired in mild AD.  相似文献   
995.
Dysplastic epithelium frequently bridges the changes between normal epithelium and noninvasive carcinoma. However, such a dysplastic lesion has not been previously described in the development of uterine papillary serous carcinoma (UPSC) or between resting endometrium and serous endometrial intraepithelial carcinoma (EIC), which is composed of indisputably malignant noninvasive cancer cells. In this study, we hypothesize that there is a lesion bridging benign endometrium and serous EIC. Based on current understanding of carcinogenesis in general, the lesion should exhibit dysplastic features that are more atypical than "resting endometrium" but fall short of serous EIC. If the putative dysplastic endometrial lesion exists, it should be highly associated with UPSC rather than uterine endometrioid carcinoma (UEC). We examined the morphologic appearance of the endometrium from 32 uteri with UPSC, 16 with serous EIC, and 60 with UEC. The endometrial dysplastic lesions were identified and their pathologic features were characterized. Immunohistochemical staining with p53 and MIB-1 were performed in all sections containing endometrial dysplastic lesions, serous EICs, and benign areas. In addition, 25 postmenopausal endometrial biopsies including 6 benign resting endometria, 8 dysplastic lesions, and 11 serous EICs were also compared for the level of p53 overexpression and cellular proliferative activity. We found that endometrial dysplastic lesions do exist in the endometrial specimens we speculated and examined. We designate it as endometrial glandular dysplasia (EmGD). EmGD was present in 17 (53%) uteri with UPSC compared with 1 (1.7%) uterus removed for UEC (p = 0.001). EmGD was identified in 12 (75%) of 16 serous EIC uteri. Areas of both EmGD and serous EIC were found in 15 (47%) of the 32 UPSC uteri. Transitions from either EmGD to serous EIC or serous EIC to UPSC were present in 8 (25%) of the UPSC cases. No transitions from EmGD to UPSC were identified in any hysterectomy specimen. EmGD was frequently found in endometrial polyps. There was no statistically significant difference between EmGD in a polyp (48%) and EmGD in nonpolypoid endometrium (52%). The majority of EmGDs were multifocal and involved superficial endometrial glands. However, single glandular involvement and endometrial surface epithelial involvement were also seen. Immunohistochemically, EmGD lesions mostly showed intermediate scores/indices of p53 and MIB-1 in comparison with serous EIC and resting endometrium. EmGD is a morphologically distinct entity, which is commonly and specifically associated with uterine tumors with serous differentiation. EmGD may represent the earliest identifiable morphologic change in the development of UPSC. Characteristics of p53 and MIB-1 immunostains of EmGD may be of diagnostic usage in surgical pathology practice. Recognition of EmGD may provide an opportunity to improve the management of UPSC.  相似文献   
996.
During the transformation from a normal to a malignant cell, several mutations are required to bypass the pathways responsible for controlling proliferation. Premalignant cells have acquired some, but not all of these mutations and consequently have not yet attained a malignant phenotype characterized by tumor formation in vivo. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) can induce apoptosis in malignant cells while sparing normal ones and is currently being considered as adjuvant therapy for various human malignancies. Whether TRAIL is effective in inducing apoptosis in premalignant cells is unclear, however. We studied the effect of TRAIL on two human premalignant cell lines the SV7tert and HA1E cells. Both cell lines had been immortalized by the addition of simian virus 40 large T antigen and the telomerase subunit hTERT, but had not been transformed into malignant cells. TRAIL initiated apoptosis by activating both the mitochondrial-independent and -dependent apoptotic pathways in both cell lines at relatively low doses whereas it had no effect on normal human pulmonary artery smooth muscle cells even at high doses. These results suggest that TRAIL can induce apoptosis in premalignant cells and suggests a novel therapy for the treatment of premalignant lesions in vivo.  相似文献   
997.
Surfactant proteins A (SP-A) and D (SP-D) play an important role in the innate immune defenses of the respiratory tract. SP-A binds to the lipid A region of lipopolysaccharide (LPS), and SP-D binds to the core oligosaccharide region. Both proteins induce aggregation, act as opsonins for neutrophils and macrophages, and have direct antimicrobial activity. Bordetella pertussis LPS has a branched core structure and a nonrepeating terminal trisaccharide. Bordetella bronchiseptica LPS has the same structure, but lipid A is palmitoylated and there is a repeating O-antigen polysaccharide. The ability of SP-A and SP-D to agglutinate and permeabilize wild-type and LPS mutants of B. pertussis and B. bronchiseptica was examined. Previously, wild-type B. pertussis was shown to resist the effects of SP-A; however, LPS mutants lacking the terminal trisaccharide were susceptible to SP-A. In this study, SP-A was found to aggregate and permeabilize a B. bronchiseptica mutant lacking the terminal trisaccharide, while wild-type B. bronchiseptica and mutants lacking only the palmitoyl transferase or O antigen were resistant to SP-A. Wild-type B. pertussis and B. bronchiseptica were both resistant to SP-D; however, LPS mutants of either strain lacking the terminal trisaccharide were aggregated and permeabilized by SP-D. We conclude that the terminal trisaccharide protects Bordetella species from the bactericidal functions of SP-A and SP-D. The O antigen and palmitoylated lipid A of B. bronchiseptica play no role in this resistance.  相似文献   
998.
We describe a combination of multiple congenital anomalies, severe psychomotor retardation and symmetrical circumferential skin creases of arms and legs in a 4.5-year-old male. Craniofacial anomalies included: a high forehead, elongated face, bitemporal sparseness of hair, broad eyebrows, blepharophimosis, bilateral microphthalmia and microcornea, severe optic nerve hypoplasia, epicanthic folds, telecanthus, broad nasal bridge, puffy cheeks, microstomia, cleft palate, enamel hypoplasia, micrognathia, microtia with stenotic ear canals and posteriorly angulated ears. Head circumference was on the 10th centile and a CT scan showed dilated lateral ventricles. Intracranial pressure was not increased. Other abnormalities included: short stature, loose skin, hypotonia, pectus excavatum, inguinal and umbilical hernias, severe scoliosis, hypoplastic scrotum, long fingers and overlapping toes. Echocardiography showed tricuspid regurgitation. Chromosomes were apparently normal. Differentiation from “Michelin tire baby syndrome” and amniotic band sequence is discussed. © 1996 Wiley-Liss, Inc.  相似文献   
999.
It is unclear whether ovarian carcinomas develop from malignant transformation of benign precursors or whether they arise de novo. Thus, histologically benign or low malignant potential components found in heterogeneous ovarian carcinomas may be remnants of pre-existing lesions that progressed to malignancy or, alternatively, elements that arose independently (de novo). In a third possible interpretation, they represent areas of malignant epithelium that matured. We evaluated clonal relationships of histological components in 10 heterogeneous ovarian carcinomas using fluorescence in situ hybridization and confocal microscopy. Detailed analysis of aneuploidy for chromosomes 8, 12, and 17 on intact paraffin sections revealed that two tumors were aneuploid in all components, two lacked abnormalities in benign-appearing components, and one lacked aneuploidy in both histologically benign and low malignant potential components. Histological appearance was significantly related to aneuploidy (P < 0.05). The distribution of aneuploidy among tumor components strongly supports the tumor progression theory and demonstrates that the de novo hypothesis is highly unlikely (P < 0.001). Results also indicate that benign-appearing components in heterogeneous ovarian carcinomas do not represent maturation of malignant tissue and suggest that some benign tumors that become cancerous may have genetic aberrations that predispose them to malignant transformation.  相似文献   
1000.
Hyperphenylalaninemia (HPA) is a group of diseases characterized by a persistent elevation of phenylalanine levels in tissues and biological fluids. The most frequent form is phenylalanine hydroxylase deficiency, causing phenylketonuria (PKU). Among 159 Israeli patients (Jews, Muslim and Christian Arabs and Druze) with HPA, in whom at least one of the mutations was characterized, a total of 43 different mutations were detected, including seven novel ones. PKU was very rare among Ashkenazi Jews and relatively frequent among Jews from Yemen, the Caucasian Mountains, Bukhara and Tunisia. The mutations responsible for the high frequency were: exon3del (Yemenite Jews), L48S (Tunisian Jews) and E178G, P281L and L48S (Jews from the Caucasian Mountains and Bukhara). Among the non‐Jewish Israeli citizens, the disease was relatively frequent in the Negev and in the Nazareth vicinity, and in many localities a unique mutation was detected, often in a single family. While marked genetic heterogeneity was observed in the Arab and Jewish populations, only one mutation A300S, was frequent in all of the communities. Several of the other frequent mutations were shared by the non‐Ashkenazi Jews and Arabs; none were mutual to Ashkenazi Jews and Arabs.  相似文献   
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