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991.

Objective

The liver flukes, Fasciola spp. and Dicrocoelium dendriticum, infect ruminants and other mammalian extensively and cause major diseases of livestock that produce considerable economic losses.

Methods

A survey of 2391 sheep and goats slaughtered at an abattoir in Amol region, northern Iran was used to determine the prevalence of the liver flukes infection based on season, sex and specie of the animals.

Results

The results revealed that the prevalence rate of Fasciola spp. and Dicrocoelium dendriticum was 6.6% and 4.3% respectively. Dicrocoeliosis was more dominant in female animals (7.1%) whereas there was no sex-related difference in the prevalence of Fasciola spp. in male and female animals. Furthermore, Fasciolosis was significantly more prevalent than dicrocoeliosis in both sheep and goats. The Seasonal prevalence of Fasciola spp. was highest (P<0.005) during spring (8.3%) followed in order by autumn (8.1%), winter (5.9%) and summer (4.0%) but Dicrocoeliosis did not follow any seasonal pattern.

Conclusions

According to this study, it can be concluded that Amol is regarded as an endemic region for Fasciola spp and D. dandriticum infection. Moreover, Fasciola spp. is the most widespread liver fluke found in sheep and goats which is more dominant in sheep than goats.  相似文献   
992.
Sustainability science has grown as a field of inquiry, but has said little about the role of large-scale private sector actors in socio-ecological systems change. However, the shaping of global trends and transitions depends greatly on the private sector and its development impact. Market-based and command-and-control policy instruments have, along with corporate citizenship, been the predominant means for bringing sustainable development priorities into private sector decision-making. This research identifies conflict as a further means through which environmental and social risks are translated into business costs and decision making. Through in-depth interviews with finance, legal, and sustainability professionals in the extractive industries, and empirical case analysis of 50 projects worldwide, this research reports on the financial value at stake when conflict erupts with local communities. Over the past decade, high commodity prices have fueled the expansion of mining and hydrocarbon extraction. These developments profoundly transform environments, communities, and economies, and frequently generate social conflict. Our analysis shows that mining and hydrocarbon companies fail to factor in the full scale of the costs of conflict. For example, as a result of conflict, a major, world-class mining project with capital expenditure of between US$3 and US$5 billion was reported to suffer roughly US$20 million per week of delayed production in net present value terms. Clear analysis of the costs of conflict provides sustainability professionals with a strengthened basis to influence corporate decision making, particularly when linked to corporate values. Perverse outcomes of overemphasizing a cost analysis are also discussed.Large-scale natural resource extraction projects (including exploration and processing activities) profoundly transform environments, communities, and economies, and often generate social conflict (2, 3). Previous studies of resource extraction and conflict have highlighted the relationship between mining and hydrocarbon resources and broader civil conflict (4, 5) and individual cases of project level conflict (6, 7). In this study, we investigate the importance of company–community conflict in the context of regulation of the sustainability performance of mining and hydrocarbon companies. We estimate the cost of social conflict to companies, determine how companies interpret this conflict, and explain how they respond to conflict. Costs were understood broadly as the negative impacts of company–community conflict on a company’s tangible and intangible assets, including value erosion. Conflict is defined as the coexistence of aspirations, interests, and world views that cannot be met simultaneously, or that actors do not perceive as being subject to simultaneous satisfaction, and is viewed in this assessment as ranging from low-level tension to escalated situations involving a complete relationship breakdown or violence (8).There is growing appreciation that unmitigated environmental and social risks have the potential to negatively influence the financial success of large-scale developments in the extractive industries. A 2008 study of 190 projects operated by the major international oil companies showed that the time taken for projects to come on-line nearly doubled in the preceding decade, causing significant increases in costs (9), although this increase reflects project remoteness, scale, technical difficulty, and input price, as well as social conflict. A follow-up of a subset of those projects found that nontechnical risks accounted for nearly one-half of the total risks faced by these companies, and that risks related to company relationships with other social actors constituted the single largest category (10). A separate empirical study of 19 publicly traded junior gold-mining companies found two-thirds of the market capitalization of these firms was a function of the firm’s stakeholder engagement practices, whereas only one-third was a function of the value of gold in the ground (11).In its analysis of socio-ecological systems (SESs), the sustainability science literature has said little about the large-scale private sector as an important actor within, and regulator of, SES behavior. A review of the 450 sustainability science articles published in PNAS, for example, finds just 23 referring to “corporate,” “industry,” “private sector,” or “company” in their texts. An extensive word cloud produced by a historical review of 20,000 papers related to sustainability science (12) notes just five terms implying a focus on the private sector (“corporate social,” “corporate sustainability,” “social responsibility,” “industrial ecology,” and “supply chain”), with none of these terms invoking core company decision making, culture, or calculations. However, large-scale corporate actors are obviously of central importance to the “major questions” for research in sustainability science (13), and perhaps especially the questions: “What shapes the long-term trends and transitions that provide the major directions for this century?” and “What determines the adaptability, vulnerability, and resilience of human–environment systems?” (13).The relevance of private sector actors is particularly clear in the extractive industries where, given the evolution of technology and industrial structure in these sectors, large enterprises have become highly influential actors in SES dynamics. Dramatic events and disasters, such as the Deepwater Horizon in the Gulf of Mexico, make this clear. Such enterprises can also be critical actors in slower processes of SES change, such as those mediating the relationships among water, agriculture, livelihoods, mining, and climate change (14, 15). Companies in the extractive industries have, to greater or lesser extent, developed policies for sustainable development and used sustainability professionals to respond to the changes induced by their activities on SESs. It is therefore important to understand the drivers of company behavior to build adequate models of socio-ecological change.This study addresses one potential driver of company behavior: conflicts motivated by the social and environmental risks created by, and the impacts of, corporate activities. More specifically, the study understands social conflict as a means through which populations communicate perceptions of risk and which generate costs for companies. The study refers to risk from the perspective of the entity experiencing the risk (i.e., environmental risks are risks to the environment; social risks are risks to society, social groups, or individuals; and business risks are the risks to the business). We ask about the significance of the costs associated with community conflict to companies, how far companies are prepared to respond to these costs by seeking strategies to reduce the environmental and social risk that they generate within SESs, and the conditions that can induce regulatory and strategic change within the corporate sector itself such that it reduces any negative environmental and social impacts.Although the report addresses just one dimension of large-scale private sector activity, the purpose is to suggest the importance of paying far more attention to corporate behavior in studies of socio-ecological dynamics. Emerging research on large-scale land acquisitions, or “land grabs” (16), and the implications for land-change science (17) suggests the same need to attend to corporate actors in sustainability science. In addressing this theme, our primary purpose is to map out, explore, and identify (rather than test) particular relationships between large-scale business and SES dynamics. The intent of the research is to build SES theory in ways that treat corporate behavior as endogenous to these systems.Through in-depth confidential interviews with corporate finance, legal, and sustainability professionals, and empirical case analysis, we investigate the extent to which recognition of the costs of conflict has the potential to change the ways in which companies address the environmental and social risks of mining and hydrocarbon development. Case studies combined desk-based analysis of secondary materials with key informant interviews to confirm or supplement the analysis. Case studies were used to characterize the types of company–community conflicts affecting mining projects, the point at which conflict took effect within the project cycle, and the types of effects that conflict appeared to have on projects. Key informant interviews were used to address how large-scale mining and hydrocarbon companies interpret these conflicts, how they respond to them, the factors determining different types of company response, and the extent to which calculations of the financial costs of conflict change the ways in which companies respond.  相似文献   
993.
994.
Dracunculiasis was rediscovered in Chad in 2010 after an apparent absence of 10 years. In April 2012 active village-based surveillance was initiated to determine where, when, and how transmission of the disease was occurring, and to implement interventions to interrupt it. The current epidemiologic pattern of the disease in Chad is unlike that seen previously in Chad or other endemic countries, i.e., no clustering of cases by village or association with a common water source, the average number of worms per person was small, and a large number of dogs were found to be infected. Molecular sequencing suggests these infections were all caused by Dracunculus medinensis. It appears that the infection in dogs is serving as the major driving force sustaining transmission in Chad, that an aberrant life cycle involving a paratenic host common to people and dogs is occurring, and that the cases in humans are sporadic and incidental.  相似文献   
995.

Aims/hypothesis

Oxidative stress plays a key role in the development of type 2 diabetes mellitus. We previously showed that the circulating antioxidant peroxiredoxin 4 (Prx4) is associated with cardiometabolic risk factors. We aimed to evaluate the association of Prx4 with type 2 diabetes risk in the general population.

Methods

We analysed data on 7,972 individuals from the Prevention of Renal and Vascular End-stage Disease (PREVEND) study (49% men, aged 28–75 years) with no diabetes at baseline. Logistic regression models adjusted for age, sex, smoking, waist circumference, hypertension and family history of diabetes were used to estimate the ORs for type 2 diabetes.

Results

During a median follow up of 7.7 years, 496 individuals (288 men; 58%) developed type 2 diabetes. The median (Q1–Q3) Prx4 level was 0.84 (0.53–1.40) U/l in individuals who developed type 2 diabetes and 0.68 (0.43–1.08) U/l in individuals who did not develop type 2 diabetes. For every doubling of Prx4 levels, the adjusted OR (95% CI) for type 2 diabetes was 1.16 (1.05–1.29) in the whole population; by sex, it was 1.31 (1.14–1.50) for men and 1.03 (0.87–1.21) for women. Further adjustment for other clinical measures did not materially change the results. The addition of Prx4 to a validated diabetes risk score significantly improved the prediction of type 2 diabetes in men (p?=?0.002 for reclassification improvement).

Conclusions/interpretation

Our findings suggest that elevated serum Prx4 levels are associated with a higher risk of incident type 2 diabetes. For men, taking Prx4 into consideration can improve type 2 diabetes prediction over a validated diabetes risk score; in contrast, there is no improvement in risk prediction for women.  相似文献   
996.
997.
998.
999.

In addition to determining the lethal effects, identifying sublethal effects of a pesticide is crucial to understanding the total impact a pesticide may have on a pest population. We determined the sublethal effects the two pesticides, abamectin and pyridaben, have on the cyclamen mite, Phytonemus pallidus (Banks) (Acari: Tarsonemidae)—a major pest of strawberry. Demographic traits of the P. pallidus progeny (F1 generation) produced by parents (F0 generation) treated with a low lethal concentration (LC15) of abamectin and pyridaben were assessed using the age-stage, two-sex life table theory. The total longevity of the F1 generation (males = 10.78 days; female = 14.35 days) was the shortest in the progeny of the abamectin treated parents, differing significantly from the progeny of mites treated with pyridaben (males = 11.50 days, females = 15.63 days), and the control population (males = 13.50 days, females = 17.81 days). The intrinsic rates of increase (r) and the finite rates of increase (λ) of the progeny of abamectin (r = 0.0854 day−1, λ = 1.0891 day−1) and pyridaben (r = 0.0951 day−1, λ = 1.0997 day−1) treated parents were significantly lower than in the control mites (r = 0.1455 day−1, λ = 1.1567 day−1). The lowest fecundity (5.35 eggs/female), occurred in F1 female offspring of parents treated with LC15 concentrations of abamectin, which was significantly lower than in the pyridaben (6.11 eggs/female) and control treatments (11.45 eggs/female). Transgenerational sublethal effects of abamectin and pyridaben in P. pallidus can be effectively used to for optimizing IPM programs against this pest on strawberries.

  相似文献   
1000.
The emergence of pandemic influenza viruses poses a major public health threat. Therefore, there is a need for a vaccine that can induce broadly cross-reactive antibodies that protect against seasonal as well as pandemic influenza strains. Human broadly neutralizing antibodies directed against highly conserved epitopes in the stem region of influenza virus HA have been recently characterized. However, it remains unknown what the baseline levels are of antibodies and memory B cells that are directed against these conserved epitopes. More importantly, it is also not known to what extent anti-HA stem B-cell responses get boosted in humans after seasonal influenza vaccination. In this study, we have addressed these two outstanding questions. Our data show that: (i) antibodies and memory B cells directed against the conserved HA stem region are prevalent in humans, but their levels are much lower than B-cell responses directed to variable epitopes in the HA head; (ii) current seasonal influenza vaccines are efficient in inducing B-cell responses to the variable HA head region but they fail to boost responses to the conserved HA stem region; and (iii) in striking contrast, immunization of humans with the avian influenza virus H5N1 induced broadly cross-reactive HA stem-specific antibodies. Taken together, our findings provide a potential vaccination strategy where heterologous influenza immunization could be used for increasing the levels of broadly neutralizing antibodies and for priming the human population to respond quickly to emerging pandemic influenza threats.The emergence of novel influenza virus strains poses a continuous public health threat (1, 2). The World Health Organization estimates that influenza viruses infect one-billion people annually, with three- to five-million cases of severe illness, and up to 500,000 deaths worldwide (3). Following influenza virus infection, humoral immune responses against the viral hemagglutinin (HA) protein may persist for decades in humans (4). These anti-HA responses correlate strongly with protection against influenza infection (5). Serological memory is maintained by antibody-secreting long-lived plasma cells and reinforced by memory B cells, which can rapidly differentiate into antibody-secreting cells upon antigen reexposure (6).Influenza vaccine efficacy is constantly undermined by antigenic variation in the circulating viral strains, particularly in the HA and neuraminidase (NA) proteins. Current influenza vaccination strategies rely on changing the HA and NA components of the annual human vaccine to ensure that they antigenically match circulating influenza strains (7, 8). Developing an influenza vaccine that is capable of providing broad and long-lasting protective antibody responses remains the central challenge for influenza virus research.HA is a trimer, with each monomer comprised of two subunits: HA1, which includes the HA globular head, and HA2, whose ectodomain together with the N- and C-terminal parts of HA1 constitute the HA stem region (9). Phylogenetically, the 18 HA subtypes characterized so far are divided into two groups. Among strains that have recently caused disease in humans, H1 and H5 HAs belong to group 1, whereas H3 and H7 HAs belong to group 2 (10). Conventional anti-HA neutralizing antibodies primarily target a few immunodominant epitopes located in proximity to the receptor-binding domain within the globular head region of the molecule (11, 12). Although these antibodies are potentially protective, they are strain-specific because of the high variability of such epitopes, and thus lack, in general, the much-desired broad neutralizing activity. Recently, broadly neutralizing human (1318) and murine (19) monoclonal antibodies (mAbs) directed against distinct epitopes within the HA stem region have been extensively characterized. These mAbs were shown to interfere with the influenza viruses’ life cycle in different ways (20). By generating monoclonal antibodies from plasmablasts isolated ex vivo, we demonstrated that these broadly neutralizing antibodies could be retrieved from patients infected with or vaccinated against the pandemic H1N1 2009 influenza virus (18, 21). Recent observations that HA stem epitopes are accessible on the majority of HA trimers on intact virions (22), and that a stable HA stem protein that is immunologically intact could be produced (23), provided further hope for the feasibility of a stem-based universal influenza vaccine (24).Notably, HA stem-specific mAbs isolated from humans showed a high degree of affinity maturation, suggesting a memory B-cell origin. These results raised two important questions that we address in the current study. First, what are the baseline levels of broadly cross-reactive stem-binding antibodies and memory B cells? Second, using current influenza vaccines, to what extent can HA stem-specific responses be boosted in comparison with those directed against the HA globular head?Structural studies have clearly demonstrated that the main neutralizing antibody epitopes within the HA stem region are conformation-dependent, and that the integrity of these epitopes requires the presence of the HA1 subunit in addition to the HA2 subunit, which constitute the bulk of the HA stem (16, 17). To be able to directly measure HA stem-reactive antibodies and memory B cells, we used a chimeric HA molecule that expresses the globular head of H9 HA on H1 backbone (25). Our data demonstrate that post-2009 trivalent inactivated vaccines (TIV) induced minimal stem-specific responses in comparison with head-specific responses. On the other hand, immunization with H5N1 generated relatively strong anti-HA stem responses, demonstrating that it is feasible to elicit broadly neutralizing responses in humans given the right immunogen design.  相似文献   
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