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排序方式: 共有1111条查询结果,搜索用时 31 毫秒
991.
目的:探讨易洛魁家族同源盒基因IRX1(Iroquois homeobox gene)在胶质瘤中的表达及其临床意义。方法:收集4 位胶质瘤
患者的胶质瘤组织和癌旁/ 正常组织各1 例,收集54 例胶质瘤组织(WHO I级5例,II 级16 例,III 级14 例,IV 级19 例),采用
PCR方法检测IRX1基因在胶质瘤细胞(U87、U373、LN229 和T98G)中的表达,Western Blot 检测4 组同一患者来源的胶质瘤组
织中IRX1 的表达,免疫组织化学法(IHC)检测IRX1 在胶质瘤组织中的表达及临床特征。结果:PCR 结果表明以正常脑组织为对
照,IRX1 基因在多种胶质瘤细胞中均有表达(P<0.05);Western Blot 结果显示IRX1 蛋白在胶质瘤组织中的表达显著高于癌旁组
织或正常组织(P<0.05);IHC结果显示IRX1蛋白在良性胶质瘤组织中主要定位于胞浆,而在恶性胶质瘤组织中定位于细胞核,
且其表达量与胶质瘤的恶性程度相关,恶性程度越高,其在细胞核中的表达量越高(P<0.05)。结论:IRX1可能参与调控恶性胶质
瘤的发生发展过程,IRX1 的表达与胶质瘤的恶性程度有关,暗示了IRX1 可作为判断胶质瘤预后以及肿瘤靶向分子治疗的指标。 相似文献
992.
目的:探讨宫颈癌组织中的人第10号染色体缺失的磷酸酶及张力蛋白同源基因(PTEN)、血管内皮生长因子(VEGF)和内皮因子(CD105)的表达及临床意义。方法:收集2010年1月至2016年2月我院收治的宫颈癌患者组织标本320例和同期正常宫颈组织标本100例,采用SP免疫组化法检测宫颈癌和正常宫颈组织中的PTEN、VEGF和CD105,分析各指标在宫颈癌、正常宫颈组织及不同类型宫颈癌组织中的表达,并采用Sperman分析三者相关关系。结果:宫颈癌组织VEGF阳性率、CD105-MVD高于正常宫颈组织,而PTEN阳性率低于正常宫颈组织,差异均有统计学意义(P0.05);宫颈癌组织FIGO分期Ⅰ~Ⅱ期的VEGF阳性率、CD105-MVD低于Ⅲ~Ⅳ期,而PTEN阳性率高于Ⅲ~Ⅳ期;宫颈癌组织伴有淋巴结转移的VEGF阳性率、CD105-MVD高于无转移,而PTEN阳性率低于无转移,差异均有统计学意义(P0.05);Sperman相关性显示VEGF与PTEN,CD105-MVD与PTEN呈现明显的负相关关系(rs=-0.564,-0.893,P0.05),VEGF与CD105-MVD呈现正相关关系(rs=0.825,P0.05)。结论:PTEN在宫颈癌组织表达降低,CD105和VEGF升高,三个指标在宫颈癌的发生、发展、转移及预后中具有重要作用。 相似文献
993.
A higher‐level classification of the Pannonian and western Pontic steppe grasslands (Central and Eastern Europe) 下载免费PDF全文
Wolfgang Willner Anna Kuzemko Jürgen Dengler Milan Chytrý Norbert Bauer Thomas Becker Claudia Biţă‐Nicolae Zoltán Botta‐Dukát Andraž Čarni János Csiky Ruzica Igić Zygmunt Kącki Iryna Korotchenko Matthias Kropf Mirjana Krstivojević‐Ćuk Daniel Krstonošić Tamás Rédei Eszter Ruprecht Luise Schratt‐Ehrendorfer Yuri Semenishchenkov Zvjezdana Stančić Yulia Vashenyak Denys Vynokurov Monika Janišová 《应用植被学》2017,20(1):143-158
994.
Climate change and temperature‐linked hatchling mortality at a globally important sea turtle nesting site 下载免费PDF全文
Jacques‐Olivier Laloë Jacquie Cozens Berta Renom Albert Taxonera Graeme C. Hays 《Global Change Biology》2017,23(11):4922-4931
The study of temperature‐dependent sex determination (TSD) in vertebrates has attracted major scientific interest. Recently, concerns for species with TSD in a warming world have increased because imbalanced sex ratios could potentially threaten population viability. In contrast, relatively little attention has been given to the direct effects of increased temperatures on successful embryonic development. Using 6603 days of sand temperature data recorded across 6 years at a globally important loggerhead sea turtle rookery—the Cape Verde Islands—we show the effects of warming incubation temperatures on the survival of hatchlings in nests. Incorporating published data (n = 110 data points for three species across 12 sites globally), we show the generality of relationships between hatchling mortality and incubation temperature and hence the broad applicability of our findings to sea turtles in general. We use a mechanistic approach supplemented by empirical data to consider the linked effects of warming temperatures on hatchling output and on sex ratios for these species that exhibit TSD. Our results show that higher temperatures increase the natural growth rate of the population as more females are produced. As a result, we project that numbers of nests at this globally important site will increase by approximately 30% by the year 2100. However, as incubation temperatures near lethal levels, the natural growth rate of the population decreases and the long‐term survival of this turtle population is threatened. Our results highlight concerns for species with TSD in a warming world and underline the need for research to extend from a focus on temperature‐dependent sex determination to a focus on temperature‐linked hatchling mortalities. 相似文献
995.
996.
Alexey Surov Hans Jonas Meyer Matthias Gawlitza Anne-Kathrin Höhn Andreas Boehm Thomas Kahn Patrick Stumpp 《Translational oncology》2017,10(1):17-21
BACKGROUND: Dynamic contrast-enhanced magnetic resonance imaging (DCE MRI) can characterize perfusion and vascularization of tissues. DCE MRI parameters can differentiate between malignant and benign lesions and predict tumor grading. The purpose of this study was to correlate DCE MRI findings and various histopathological parameters in head and neck squamous cell carcinoma (HNSCC). PATIENTS AND METHODS: Sixteen patients with histologically proven HNSCC (11 cases primary tumors and in 5 patients with local tumor recurrence) were included in the study. DCE imaging was performed in all cases and the following parameters were estimated: Ktrans, Ve, Kep, and iAUC. The tumor proliferation index was estimated on Ki 67 antigen stained specimens. Microvessel density parameters (stained vessel area, total vessel area, number of vessels, and mean vessel diameter) were estimated on CD31 antigen stained specimens. Spearman''s non-parametric rank sum correlation coefficients were calculated between DCE and different histopathological parameters. RESULTS: The mean values of DCE perfusion parameters were as follows: Ktrans 0.189 ± 0.056 min−1, Kep 0.390 ± 0.160 min−1, Ve 0.548 ± 0.119%, and iAUC 22.40 ± 12.57. Significant correlations were observed between Kep and stained vessel areas (r = 0.51, P = .041) and total vessel areas (r = 0.5118, P = .043); between Ve and mean vessel diameter (r = −0.59, P = .017). Cell count had a tendency to correlate with Ve (r = −0.48, P = .058). In an analysis of the primary HNSCC only, a significant inverse correlation between Ktrans and KI 67 was identified (r = −0.62, P = .041). Our analysis showed significant correlations between DCE parameters and histopathological findings in HNSCC.Dynamic contrast-enhanced magnetic resonance imaging (DCE MRI) has been reported as a technique which is able to characterize perfusion and vascularization of tissues [1], [2]. It has been shown that DCE MRI can be helpful to differentiate between malignant and benign lesions [1]. For example, Yuan et al. reported that lung cancer had a larger volume transfer constant (Ktrans) and a lower volume of the extravascular extracellular leakage space (Ve) in comparison to benign lesions [3]. Similar results were reported by Li et al. for breast lesions [4]. Furthermore, according to Cho et al., DCE MRI parameters can be used to distinguish prostatic cancer from benign changes [5]. Moreover, DCE MRI parameters can also predict tumor grading. As reported previously, Ktrans correlated well with Gleason score in prostatic cancer [5], [6]. According to other reports, Ktrans and Ve correlated with glioma grade [7], [8].DCE MRI parameters were also associated with prognosis in several malignancies [9], [10]. Koo et al. showed that breast cancers with higher Ktrans or lower Ve had poor prognostic factors and were often of the triple-negative subtype [10].According to the literature, DCE MRI parameters can predict response to therapy in different tumors. For instance, some authors mentioned that low pretreatment Ktrans in regional lymph node metastases in head and neck cancer was associated with a poor response to concurrent chemoradiation therapy [11].Furthermore, Andersen et al. showed that DCE MR parameters obtained prior to chemoradiotherapy predicted survival of patients with cervical cancer [12].Presumably, DCE MRI parameters may be based on tissue composition, such as cellularity and vascular density. However, in this regard there are contradictory data in the literature. While some studies identified significant correlations between DCE MRI and histopathological parameters, others did not [13], [14], [15], [16].The purpose of this study was to correlate DCE MRI findings and various histopathological parameters in head and neck squamous cell carcinoma (HNSCC). 相似文献
997.
998.
The initiation of the floral organs of Nandina domestica Thunb. (Berberidaceae) is of the trimemus-whorled pattern. Stamens and petals grew out from the lateral bifurcation of the common stamen-petal primordia; but petals underwent retarded periods of growth in their early development. Carpel initiation belongs to the ascidiate type. Some aspects concerning the trimerous floral organs, the origin of petals, stamen insertion pattem and monocarpellary pistil were discussed. In addition the floral ontogenetic characters among three genera of the Berberidaceae, i.e., Caulophyllum, Podophyllum and Nanclina were compared. It is inferred that the trimerous-whoded arrangement and the diversity of carpel initiation were the two unique characters of Nandina. 相似文献
999.
1000.
中国条鳅亚科鱼类的鳔和骨质鳔囊的研究 总被引:4,自引:0,他引:4
通过对我国条鳅亚科鱼类及部分种类幼体的骨质鳔囊和鳔的形态特征的观察,阐明骨质鳔囊的形成与前面四节椎骨的关系;依据骨质鳔囊的形态,分为敞开型和封闭型两个型,后者又可以分为两个亚型:常态亚型和膨大亚型;依据鳔的前、后两室中后室的发达和萎缩程度,也可将鳔分为双室型和单室型;并对上述不同类型的骨质鳔囊和鳔与条鳅鱼类的生态适应、演化规律和系统分类等方面的关系进行了讨论。
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