首页 | 官方网站   微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   264822篇
  免费   14409篇
  国内免费   2118篇
医药卫生   281349篇
  2023年   1636篇
  2022年   1434篇
  2021年   4947篇
  2020年   3170篇
  2019年   4946篇
  2018年   8544篇
  2017年   5854篇
  2016年   5870篇
  2015年   6914篇
  2014年   7508篇
  2013年   10809篇
  2012年   18204篇
  2011年   18234篇
  2010年   9550篇
  2009年   7295篇
  2008年   15258篇
  2007年   16301篇
  2006年   15140篇
  2005年   14892篇
  2004年   13783篇
  2003年   12728篇
  2002年   11891篇
  2001年   6898篇
  2000年   6874篇
  1999年   6181篇
  1998年   1306篇
  1997年   1148篇
  1996年   1025篇
  1995年   950篇
  1994年   824篇
  1992年   3461篇
  1991年   3100篇
  1990年   2948篇
  1989年   2645篇
  1988年   2522篇
  1987年   2315篇
  1986年   2194篇
  1985年   1968篇
  1984年   1494篇
  1983年   1237篇
  1979年   1260篇
  1978年   896篇
  1977年   831篇
  1975年   831篇
  1974年   1029篇
  1973年   1045篇
  1972年   962篇
  1971年   960篇
  1970年   891篇
  1969年   928篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
目的 对比研究朝鲜淫羊藿酸性多糖酯化还原前后的理化特性,并探讨其改善油酸诱导的肝癌HepG2细胞脂质堆积活性的差异。方法 采用高效凝胶渗透色谱法测定朝鲜淫羊藿酸性多糖(EFPA)的均一性和分子量,高效液相色谱法测定EFPA和酯化还原后朝鲜淫羊藿酸性多糖(EFPA-R)的单糖组成;采用油酸(OA)处理HepG2细胞诱导建立脂质蓄积模型,不同浓度EFPA与EFPA-R(10、30、100、300 μg·mL-1)分别和OA共同作用于细胞24 h,采用CCK-8试剂盒测定细胞存活率,油红O染色观察细胞内脂滴蓄积情况,并采用试剂盒测定细胞内总胆固醇(TC)、甘油三酯(TG)含量。结果 EFPA为成分均一的多糖组分,分子量为125.8 kDa,由甘露糖、葡萄糖、半乳糖、葡萄糖醛酸和阿拉伯糖组成,摩尔比为1.7∶7.4∶1.4∶1.8∶1.0,葡萄糖占比最大,EFPA-R由甘露糖、葡萄糖、半乳糖和阿拉伯糖组成,摩尔比为0.8∶10.6∶2.1∶1.0;在10-300 μg·mL-1范围内,EFPA和EFPA-R对HepG2细胞的抑制作用较弱,作为给药浓度;与空白组相比,模型组细胞中TC、TG含量显著升高(P < 0.01),细胞内红色脂滴显著增多,与模型组相比,EFPA可显著降低细胞中TC、TG含量(P < 0.01),明显减少细胞内红色脂滴(P < 0.05或P < 0.01),EFPA-R干预后细胞则无明显变化。结论 EFPA可明显改善HepG2细胞脂质堆积情况,且呈现剂量依赖性,而半乳糖醛酸(GalA)的存在可能是其抑制HepG2细胞脂质蓄积的关键因素。  相似文献   
2.
ObjectivesTrauma appears within the discourse of mentally injured people, materializing what we have recently defined as “post traumatic psycholinguistic syndrome” (SPLIT). Translating unspeakability, revival, and dissociation, this clinical entity associates three significant disturbances : traumatic anomia (missing words, reduction of the elocutionary flow, deictic gestures, etc.); linguistic repetitions (of words and phrases, verbal intrusions, echophrasias, etc.); and phrasal and discursive disorganization (incomplete sentences, tense discordance, dysfluence, lack of logical connectors, etc.). What are the causes of these semiological and psycholinguistic expressions? What are their psychological and/or neuropsychological processes? It is time to come up with a new concept intended to go beyond the previous models in order to better identify people suffering from post-traumatic mental disorders, to better organize and evaluate psychotherapeutic care, and also to help practitioners collaborate more effectively on these first two goals. But how to evoke, affirm, or speak out about the consequences of unspeakability? Nothing is more apparently contradictory than wanting to define the language void. How to account for the fractures of psychic trauma in discourse? Nothing is more uncertain than to try to organize the upheavals, the disorders caused by dissociation in language. Finally, how to specify the reiteration of the trauma using words and sentences without this modeling being dissociative or repetitive? Today, thanks to a psycholinguistic reading, essential dimensions of post-traumatic suffering, hitherto hidden, can be clarified. Why exactly does an event cause trauma in the life of a subject at a given moment in her/his existence? Why is a latency phase structured between the traumatic event and the return of reviviscences under the influence of a re-triggering factor? How to differentiate the notion of dissociation as a normal phenomenon from the so-called traumatic dissociation? How to explain the multiple clinical forms of post-traumatic psychological disorders?MethodsFrom Pierre's clinical history, we chronologically detail the structuring and the consequences of the signified reflection that are constitutive of the psychic trauma: the psycholinguistic tools here help to formulate a new etiopathogenic conception of trauma and its psychological consequences. Then, thanks to Jean's testimony, taking up the retrospective meaning of the clinical analysis from chronic repetition syndrome, we discover the phases of tension regarding signified knowledge, up to the network prior to the traumatic confrontation. Finally, illustrated by Karima's disorder, beyond depersonalization, we explain that the analysis of the disturbances of a singular signified network, and also of an attack on its familial and societal bases, testifies to individual and collective subjectivities.ResultsComing from the real world, and therefore also from the body, the stimuli made up of signals picked up by our senses combine to compose an event that can be objectified by its temporal, spatial, biological, and physico-chemical coordinates. These elements combine into a unit, which is then interpreted by the mind, which attributes meaning to this event, which has become subjective reality. But when the subject is not sufficiently prepared to be confronted with this meaning that appears to be in extreme contradiction with her/his previous cardinal networks of significations, it makes “too much sense:” this irreconcilable hyper-signified (that we call the traumatic signified) results in post-traumatic dissociation. In other words, it is an impossibility of concordance of a signified with certain systems of prior significations that constitutes the pathogenesis of the trauma; and a situation runs a greater risk of being traumatic when it contradicts, or, moreso, endangers some or all of the subject's cardinal meanings. This unbearable signified reflexively blocks the capacities of significations immediately pre- and post-trauma, then dissociates the psychic functions to varying degrees and intensities. The traumatic signified, rejected, becomes unattainable: the stimuli that led to its formation find themselves confined to the state of reviviscences, each replication of which attempts to cross the barrier of inconceivability. Limiting sensory compounds to their raw states without the possibility of representational integration, associative pathways remain blocked. The signifier is referred to a hypo-signifier confined to the infra-linguistic by its confusion with the referent, the “objective and material” components of the traumatic event. Dissociation is therefore only a symptomatic reaction, secondary to the trauma, which it reinforces once again by limiting any possibility of representing the trauma. This dissociation does not involve forgetting the traumatic signified but “protects” the adjacent networks of meanings from it as much as it “keeps” this hypersignified intact, therefore ultimately “protecting” it as well. The traumatic signified persists somewhere, and even ends up being found everywhere: when the networks of meanings turn out to be globally disturbed, the tightest links remain those of the traumatic hypersignified that ultimately governs all the networks of meanings.DiscussionOur insufficient knowledge prevents us from precisely qualifying the architecture of the signified idiosyncratic networks and their evolutionary capacities; we cannot predict, beforehand, the reaction of an individual confronted with a potentially psychotraumatic situation. For most clinical situations, we affirm that the psychological trauma occurs in a psychically healthy subject, that is, not suffering from any psychiatric illness or any obvious psychopathological conflict. Psychotherapy will make it possible to discover the signified, sometimes ancient, origins of a trauma occurring in a singular subject. How was this subjectivity constructed? Beyond individual subjectivity, the intensity of certain confrontations such as serious attacks or macrosocial catastrophes such as genocide, would seem to lead to psychological wounds in any individual, even at the scale of a population. While, throughout existence, each subject produces a system of significations in connection with a unique psychic construction, the latter persists – resulting from, and often remaining overseen by, the community essence of a base of signifying networks, which we call “societal subjectivity.” Here, the psychological trauma can correspond to an individual and “common” injury as a failure of a sharing, or of ancestral beliefs anchored in the collective memory, defining the culture. By the collapse of acquired certainties, the cognitive patterns transmitted by education, language, and everything that establishes one's belonging to a society, trauma shakes the networks of individual and group meanings. Horror has a higher traumatogenic risk, because it defeats the fundamentals of humankind, the foundations of a signified network common to a culture, or even to all cultures, to the human condition. This is the case with murder, rape, torture, wars, genocides. Testifying to an instinct for survival stemming from the biological foundations of every living being, the impossibility of “living death” appears to be anchored in our networks of meanings and is manifested by indescribability, traumatic as such: being deserted by the language collides with the condition of speaking. And yet, it remains possible to say something about it... As a path of progressive desocialization, the occasional loss of the community of language, followed by its lasting traumatic ravages, can be appeased by the reestablishment of a speech link, either within the mind of the subject alone, or promoted by the exchange with others, in a psychotherapeutic setting, for example.ConclusionWhere theoretical discourses have sometimes proved divisive, going beyond the symptoms of indescribability and dissociation, psychodynamic practice today offers to unite. Thanks to psycholinguistic listening, phenomena that have never been explained take on meaning: the singularity of traumatic perception, the chronology of disorders including the latency phase, factors that trigger reviviscences, and the diversity of chronic clinical forms. All these post-traumatic symptoms are consequential to a linguistic wound, a difficulty in accessing meaning, the undermining of two dimensions characterizing and constructing the human being. As much as it integrates extralinguistic determinants, if the traumatic signified is undoubtedly not only speech, language appears the optimal way to identify it as such, while in the same movement appeasing it. The traumatic hypersignified is discovered through clinical analysis and psychotherapy, through deferred action, through the attribution of meaning, through the retrospective reconstruction of an unstable “real,” through a changing narration eternally distancing itself from reviviscences. But what precisely are the mechanisms of effective therapies ? What are the intersubjective links called for in the discussion between patient and practitioner? Could the operations that we call “psychotherapy” be made up of mobilizations of the networks of meanings by speech acts?  相似文献   
3.
The adrenal cortex gives rise to a biologically heterogenous group of neoplasms, each with a distinct morphology, antigen expression and molecular profile. Adrenal cortical adenomas have excellent prognosis and are usually cured by surgical resection alone, while adrenal cortical carcinomas are very aggressive tumors with a poor prognosis regardless of therapy. These tumors are rare and often challenging for a pathologist to diagnose, as significant overlap exists between benign and malignant lesions in some cases. In this review, we attempt to summarize most important histologic and clinical features of adrenal cortical adenomas and carcinomas, clarify the use of different grading systems, the use of special stains and the differential diagnosis for practicing pathologists. Most relevant hereditary syndromes associated with adrenal cortical tumors are listed. Updates in molecular alterations in adrenal cortical neoplasms and hyperplastic diseases as well as their clinical significance and potential therapeutic implications are also discussed.  相似文献   
4.
5.
6.
Krüppel-like factor 16 (KLF16), a member of the Krüppel-like factor (KLF) family, has been extensively investigated in multiple cancer types. However, the role of KLF16 in oral squamous cell carcinoma (OSCC) remains unknown. Thus, we conducted this study to investigate its related mechanism. KLF16 expression in OSCC cell lines was quantified by western blotting. Then, OECM1 and OC3 cells were divided into Blank, siCtrl, siKLF16#1 and siKLF16#2 groups. Subsequently, cell proliferation was detected using 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assays, cell migration and invasion were detected with wound healing and Transwell assays, and cell cycle distribution and cell apoptosis were detected via flow cytometry. KLF16, p21, CDK4, Cyclin D1 and p-Rb expression was detected by western blotting. Finally, xenograft models were established in nude mice to observe the in vivo effects of KLF16 on OSCC. KLF16 protein expression was upregulated in OSCC cells. Compared to the cells in the Blank group, the OECM1 and OC3 cells in the siKLF16#1 group and siKLF16#2 group exhibited a sharp decrease in proliferation but a remarkable increase in apoptosis. Moreover, the proportion of cells in the G0/G1 phase notably increased and that in the S phase decreased, with evident decreases in cell invasion and migration. Moreover, KLF16, cyclin-dependent kinase 4 (CDK4), Cyclin D1 and p-Rb protein expression was upregulated, but p21 expression was downregulated. The mice in the siKLF16#1 and siKLF16#2 xenograft model groups exhibited slower tumour growth and smaller tumours with evident downregulation of Ki67 expression compared to the mice in the Blank group. KLF16 expression was upregulated in OSCC cells, and interfering with KLF16 led to cell cycle arrest, inhibited OSCC cell growth and promoted cell apoptosis.  相似文献   
7.
Journal of Immigrant and Minority Health - COVID-19 has disproportionally affected underrepresented minorities (URM) and low-income immigrants in the United States. The aim of the study is to...  相似文献   
8.
Cyclotron-produced copper-64 radioisotope tracers offer the possibility to perform both diagnostic investigation by positron emission tomography (PET) and radiotherapy by a theranostic approach with bifunctional chelators. The versatile chemical properties of copper add to the importance of this isotope in medicinal investigation. [64Cu][Cu (ATSM)] has shown to be a viable candidate for imaging of tumor hypoxia; a critical tumor microenvironment characteristic that typically signifies tumor progression and resistance to chemo-radiotherapy. Various production and radiosynthesis methods of [64Cu][Cu (ATSM)] exist in labs, but usually involved non-standardized equipment with varying production qualities and may not be easily implemented in wider hospital settings. [64Cu][Cu (ATSM)] was synthesized on a modified GE TRACERlab FXN automated synthesis module. End-of-synthesis (EOS) molar activity of [64Cu][Cu (ATSM)] was 2.2–5.5 Ci/μmol (HPLC), 2.2–2.6 Ci/μmol (ATSM-titration), and 3.0–4.4 Ci/μmol (ICP-MS). Radiochemical purity was determined to be >99% based on radio-HPLC. The final product maintained radiochemical purity after 20 h. We demonstrated a simple and feasible process development and quality control protocols for automated cyclotron production and synthesis of [64Cu][Cu (ATSM)] based on commercially distributed standardized synthesis modules suitable for PET imaging and theranostic studies.  相似文献   
9.
Introduction: Immune checkpoint inhibitors (ICI) are now a standard of care in the treatment of many cancers leading to durable responses in patients with metastatic disease. These agents are generally well tolerated but may lead to the occurrence of immune-related adverse events (irAEs). As any organ may be affected, clinicians should be aware of the broad range of clinical manifestations and symptoms and keep in mind that toxicities may occur late, at any point along a patient’s treatment course. Although the most common irAEs are rarely severe, some of them may be associated with great morbidity and even become life-threatening. The rate of occurrence, type and severity of irAEs may vary with the type of ICI; thus, grade 3 and 4 irAEs are reported in more than 55% of patients treated with the combination of ipilimumab 3 mg/kg and nivolumab 1 mg/kg.

Area covered: This review presents the management of irAEs resulting from checkpoint blockade, with a focus on rare irAEs.

Expert commentary: With the development of immuno-oncology and the expanding role of ICI, physicians have learnt to diagnose and treat most of the irAEs that can occur. This review provides an overview of current guidelines, previously published studies and our multidisciplinary team based practices.  相似文献   

10.
Adjuvant irradiation is the standard treatment after breast conservative surgery. Normofractionated regimen with an overall treatment time of 5 to 6 weeks is often considered as a limiting factor for irradiation compliance. In order to answer this issue, moderate and more recently extreme hypofractionated protocols appeared. We report here oncological outcomes and toxicity of hypofractionated breast irradiation. After defining the frame of moderate and extreme hypofractionated breast irradiations based on overall treatment time, patient selection criteria were listed. According to their levels of proof, the results of moderate and extreme hypofractionated breast irradiation were analysed. Overall treatment time for moderate hypofractionated breast irradiation ranged from 3 to 4 weeks, while for extreme hypofractionated breast irradiation, it was less than 1 week. For moderate hypofractionated breast irradiation, whole breast irradiation was currently performed with or without lymph node irradiation. Moderate hypofractionated breast irradiation has proven to be as safe and as efficient as normofractionated breast irradiation with level IA evidence. For extreme hypofractionated breast irradiation, phase III randomized trials confirmed that accelerated partial breast irradiation was non-inferior in terms of local control compared to normofractionated whole breast irradiation (with external beam radiation therapy and multicatheter brachytherapy), with similar acute and late toxicity. While the use of intraoperative breast irradiation remains under debate, new very accelerated partial breast irradiation (overall treatment time not exceeding 2 days) protocols emerged with encouraging results. Accelerated partial breast irradiation is warranted for extreme hypofractionated breast irradiation and is indicated for low-risk breast cancers. Moderate and extreme hypofractionated breast irradiation regimens are validated and can be routinely proposed according to patient selection criteria.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号