全文获取类型
收费全文 | 2358篇 |
免费 | 95篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 19篇 |
儿科学 | 38篇 |
妇产科学 | 22篇 |
基础医学 | 362篇 |
口腔科学 | 16篇 |
临床医学 | 150篇 |
内科学 | 663篇 |
皮肤病学 | 88篇 |
神经病学 | 239篇 |
特种医学 | 100篇 |
外科学 | 406篇 |
综合类 | 18篇 |
一般理论 | 3篇 |
预防医学 | 125篇 |
眼科学 | 26篇 |
药学 | 94篇 |
肿瘤学 | 86篇 |
出版年
2023年 | 13篇 |
2022年 | 15篇 |
2021年 | 39篇 |
2020年 | 34篇 |
2019年 | 31篇 |
2018年 | 44篇 |
2017年 | 31篇 |
2016年 | 41篇 |
2015年 | 33篇 |
2014年 | 60篇 |
2013年 | 83篇 |
2012年 | 127篇 |
2011年 | 161篇 |
2010年 | 78篇 |
2009年 | 89篇 |
2008年 | 130篇 |
2007年 | 181篇 |
2006年 | 153篇 |
2005年 | 151篇 |
2004年 | 120篇 |
2003年 | 81篇 |
2002年 | 98篇 |
2001年 | 22篇 |
2000年 | 25篇 |
1999年 | 26篇 |
1998年 | 25篇 |
1997年 | 10篇 |
1996年 | 19篇 |
1995年 | 21篇 |
1994年 | 24篇 |
1993年 | 12篇 |
1989年 | 10篇 |
1978年 | 9篇 |
1960年 | 10篇 |
1958年 | 9篇 |
1943年 | 9篇 |
1939年 | 8篇 |
1936年 | 10篇 |
1935年 | 8篇 |
1933年 | 13篇 |
1932年 | 12篇 |
1931年 | 11篇 |
1930年 | 9篇 |
1929年 | 10篇 |
1928年 | 9篇 |
1927年 | 15篇 |
1926年 | 13篇 |
1925年 | 15篇 |
1924年 | 14篇 |
1911年 | 11篇 |
排序方式: 共有2455条查询结果,搜索用时 62 毫秒
81.
Tobias I Ndubuisi Ezejiofor Anthonet N Ezejiofor Orish E Orisakwe Hariet C Nwigwe Ferdinand OU Osuala Moses OE Iwuala 《Journal of occupational medicine and toxicology (London, England)》2014,9(1):1-14
Background
Literature abounds linking one’s job to certain unpalatable health outcomes. Since exposures to hazardous conditions in industrial environments often results in sundry health effects among workers, we embarked on this study to investigate the hepatic health effects of occupational activities in the petroleum refining and distribution industry.Method
Biochemical markers of liver functions were assayed in plasma, using Reflotron dry chemistry spectrophotometric system. The study was conducted on randomly selected workers of Port Harcourt Refining Company (PHRC) and Pipelines and Petroleum Product Marketing Company (PPMC) both in Alesa-Eleme near Port Harcourt, Nigeria, as well as non-oil work civil servants serving as control subjects.Result and conclusion
Results showed that, bilirubin ranged 0.3-1.6 mg/dl with a mean of 0.66±0.20mg/dl among the oil workers as against 0.5-1.00mg/dl with a mean of 0.58±0.13mg/dl in non-oil workers, Alkaline phosphatase ranged 50.00-296.00u/l (mean: 126.21±39.49u/l) in oil workers as against 40.20-111u/l (mean: 66.83±18.54u/l) for non-oil workers, Aspartic transaminases (AST) ranged 5.80-140.20u/l (mean: 21.81±11.49u/l) in oil workers against 18.00-44.00u/l (mean: 26.89±6.99u/l) for non-oil workers, while Alanine transaminases (ALT) ranged 4.90-86.00u/l (mean: 22.14±11.28u/l) in oil workers as against 10.00-86.60u/l (mean: 22.30±10.22u/l) for the non-oil workers. A close study of the results revealed that although the mean values for all the studied parameters were still within the parametric reference ranges, however, relative to the referents, there were significant increases (P<0.05) in plasma bilirubin (though anicteric) and alkaline phosphatase that was not matched with a corresponding increase in the plasma transaminases, suggesting a possibility that toxic anicteric hepatoxicity is part of the potential health effects of sundry exposures in the Nigeria petroleum oil refining and distribution industry. Gender differentiation data showed that though the mean values for the parameters were higher in males than females, the increases were not significant in most cases (P>0.05), whereas data for age and exposure period classifications revealed that irrespective of the age of the worker, the effects are likely to start after the first five years, manifesting fully after the first decade of occupational exposures. Thus, an update of industrial/occupational health measures is necessary for a safer and healthier work environment. 相似文献82.
Jean H. Daugrois Denis Filloux Charlotte Julian Lisa Claude Romain Ferdinand Emmanuel Fernandez Hugo Fontes Philippe C. Rott Philippe Roumagnac 《Viruses》2021,13(5)
Visacane is a sugarcane quarantine station located in the South of France, far away from sugarcane growing areas. Visacane imports up to 100 sugarcane varieties per year, using safe control and confinement measures of plants and their wastes to prevent any risk of pathogen spread outside of the facilities. Viruses hosted by the imported material are either known or unknown to cause disease in cultivated sugarcane. Poaceae viruses occurring in plants surrounding the quarantine glasshouse are currently unknown. These viruses could be considered as a source of new sugarcane infections and potentially cause new sugarcane diseases in cases of confinement barrier failure. The aim of this study was to compare the plant virome inside and outside of the quarantine station to identify potential confinement failures and risks of cross infections. Leaves from quarantined sugarcane varieties and from wild Poaceae growing near the quarantine were collected and processed by a metagenomics approach based on virion-associated nucleic acids extraction and library preparation for Illumina sequencing. While viruses belonging to the same virus genus or family were identified in the sugarcane quarantine and its surroundings, no virus species was detected in both environments. Based on the data obtained in this study, no virus movement between quarantined sugarcane and nearby grassland has occurred so far, and the confinement procedures of Visacane appear to be properly implemented. 相似文献
83.
Lee Kam-Ho Tse Man-Lap Donald Law Martin Cheng Andrew Kai-Chun Wong Ho-Yuen Frank Yu Man-Leung Li Yan-Lin Ho Yuen-Chi Chu Ferdinand Lam Wendy Wai-Man 《Abdominal imaging》2019,44(3):903-911
Abdominal Radiology - To develop and validate a scoring system using a combination of imaging and clinical parameters to predict 30-day mortality in ruptured HCC (rHCC) patients after transarterial... 相似文献
84.
Grassi D O'Flaherty M Pellizzari M Bendersky M Rodriguez P Turri D Forcada P Ferdinand KC Kotliar C;Group of Investigators of the REHASE Program 《Journal of clinical hypertension (Greenwich, Conn.)》2008,10(9):662-667
To study the efficacy of a treatment strategy for the management of hypertensive urgencies, the authors evaluated 549 patients admitted to the emergency department. They were first assigned to a 30-minute rest period, then a follow-up blood pressure measurement was carried out. Patients who did not respond to rest were randomly assigned to receive an oral dose of an antihypertensive drug with different mechanisms of action and pharmacodynamic properties (perindopril, amlodipine, or labetalol), and blood pressure was reassessed at 60- and 120-minute intervals. A satisfactory blood pressure response to rest (defined as postintervention systolic blood pressure < 180 mm Hg and diastolic blood pressure < 110 mm Hg, with at least a 20 mm Hg reduction in basal systolic blood pressure and/or a 10-mm Hg reduction in basal diastolic blood pressure) was observed in 31.9% of population. Among nonresponders, 79.1% had a satisfactory blood pressure response to the antihypertensive drug treatment in a 2-hour average follow-up period. No major adverse events were observed. This treatment strategy, based on standardized rest as an initial step and different antihypertensive drugs, can be effective and safe for the management of patients with hypertensive urgencies. 相似文献
85.
Ferdinand Roth 《Journal of cancer research and clinical oncology》1957,61(5):468-503
Ohne ZusammenfassungMit 12 Textabbildungen 相似文献
86.
Tolboom TC van der Helm-Van Mil AH Nelissen RG Breedveld FC Toes RE Huizinga TW 《Arthritis and rheumatism》2005,52(7):1999-2002
OBJECTIVE: Rheumatoid arthritis (RA) is characterized by inflammation and destruction of synovial joints. Fibroblast-like synoviocytes (FLS) harvested from synovial tissue of patients with RA can invade normal human cartilage in severe combined immunodeficient (SCID) mice and Matrigel basement membrane matrix in vitro. This study was undertaken to investigate the association of these in vitro characteristics with disease characteristics in patients with RA. METHODS: Synovial tissue samples from 72 RA and 49 osteoarthritis (OA) patients were obtained. Samples of different joints were collected from 7 patients with RA. The FLS invasiveness in Matrigel was studied, and the intraindividual and interindividual differences were compared. From the patients with FLS who exhibited the most extreme differences in in vitro ingrowth (most and least invasive FLS), radiographs of the hands and feet were collected and scored according to the Sharp/van der Heijde method to determine the relationship between in vitro invasion data and estimated yearly joint damage progression. RESULTS: FLS from patients with RA were more invasive than FLS from patients with OA (P < 0.001). The mean intraindividual variation in FLS invasion was much less than the mean interindividual variation (mean +/- SD 1,067 +/- 926 and 3,845 +/- 2,367 for intraindividual and interindividual variation, respectively; P = 0.035), which shows that the level of FLS invasion is a patient characteristic. The mean +/- SEM Sharp score on radiographs of the hands or feet divided by the disease duration was 4.4 +/- 1.1 units per year of disease duration in patients with the least invasive FLS (n = 9), which was much lower compared with the 21.8 +/- 3.1 units per year of disease duration in patients with the most invasive FLS (n = 9) (P < 0.001). CONCLUSION: The ex vivo invasive behavior of FLS from RA patients is associated with the rate of joint destruction and is a patient characteristic, given the much smaller intraindividual than interindividual FLS variation. 相似文献
87.
88.
Partha Sardar Ramez Nairooz Saurav Chatterjee Savi Mushiyev Gerald Pekler Ferdinand Visco 《Journal of thrombosis and thrombolysis》2014,38(1):1-10
Cangrelor is a new parenteral adenosine diphosphate P2Y12 receptor inhibitor with rapid, profound and reversible inhibition of platelet activity. The aim of this meta-analysis was to evaluate efficacy and safety of this new agent in patients undergoing percutaneous coronary intervention (PCI). We searched PubMed, Cochrane Library, EMBASE, Web of Science and CINAHL databases from the inception through April 2013. Randomized controlled trials (RCTs) comparing cangrelor with control (clopidogrel/placebo) were selected. We used the random-effects models to calculate the risk ratio. The primary efficacy outcome was risk of myocardial infarction, and the primary safety outcome was TIMI major bleeding at 48 h. Three RCTs included a total of 25,107 participants. Effects of Cangrelor were not different against comparators for myocardial infarction (MI) (Risk ratio [RR] 0.94, 95 % confidence interval [CI] 0.78–1.13) and all-cause mortality (RR 0.72, 95 % CI 0.36–1.43). However, cangrelor significantly reduced the risk of ischemia-driven revascularization (RR 0.72, 95 % CI 0.52–0.98), stent thrombosis (RR 0.60, 95 % CI 0.44–0.82) and Q wave MI (RR 0.53, 95 % CI 0.30–0.92) without causing extra major bleeding (Thrombolysis in Myocardial infarction criteria) and severe or life-threatening bleeding (Global utilization of streptokinase and tissue plasminogen activator for occluded coronary arteries criteria). Separate analysis against only clopidogrel also showed similar findings except Q wave MI outcome. Use of cangrelor during PCI might reduce the risk of ischemia-driven revascularization and stent thrombosis, without causing extra major bleeding. 相似文献
89.
Matthew J. Budoff Sandy Liu David Chow Ferdinand Flores Brian Hsieh Dan Gebow Tony DeFrance Naser Ahmadi 《Atherosclerosis》2014
Background: Previous studies have shown that computed tomography coronary angiography (CTA) in patients with suspected coronary artery disease (CAD) predicts short term adverse events. However, there is no current data on whether identifying atherosclerosis on CTA impacts outcomes. We performed a case–control study to assess whether information from CTA can improve outcomes. Methods: 4244 symptomatic patients (mean age 58 ± 9, 62.5% male) without known CAD who underwent CTA (n = 2538) to rule out CAD were matched to 1706 patients who underwent standard of care in an academic cardiology clinic. Patients were propensity-matched by gender, age, ethnicity, CAD risk factors and follow-up duration. The primary outcome measure was all-cause mortality. Multivariable Cox proportional hazards models incorporated age, gender and traditional risk factors for coronary disease as well as pre-test probability of CAD. Results: There were no significant differences in age, gender, conventional risk factors between groups (p > 0.05). During a mean follow up of 80 ± 11 months, the overall death rate was 6.3% (270 deaths). Death rate was significantly lower in CTA group (n = 106, 4.2%) as compared to the control group (n = 184, 10.8%, p = 0.001). Event free survival was 95.8% and 89.2% in CTA and standard of care groups, respectively. Risk-adjusted hazard ratio of death were 2.5 (95%CI: 1.6–6.7, p = 0.003) in standard of care cohort as compared to CTA group. Multivariate analysis demonstrated that undergoing coronary CTA resulted in a risk reduction of 32%, p = 0·0001. Conclusions: Improved knowledge of atherosclerosis or increased anti-atherosclerotic therapies among those undergoing CTA may have contributed to improved survival. Our results provide evidence of potential benefit from scanning for atherosclerosis with CTA in symptomatic patients. Large randomized trials are warranted. 相似文献
90.
Alva O. Ferdinand Nir Menachemi Bisakha Sen Justin L. Blackburn Michael Morrisey Leonard Nelson 《American journal of public health》2014,104(8):1370-1377
Using a panel study design, we examined the effects of different types of texting bans on motor vehicular fatalities.We used the Fatality Analysis Reporting System and a difference-in-differences approach to examine the incidence of fatal crashes in 2000 through 2010 in 48 US states with and without texting bans. Age cohorts were constructed to examine the impact of these bans on age-specific traffic fatalities.Primarily enforced laws banning all drivers from texting were significantly associated with a 3% reduction in traffic fatalities in all age groups, and those banning only young drivers from texting had the greatest impact on reducing deaths among those aged 15 to 21 years. Secondarily enforced restrictions were not associated with traffic fatality reductions in any of our analyses.Motor vehicle safety has been described as one of the 10 great public health achievements in the United States in the past decade,1 with car manufacturers and highway engineers making significant improvements to car and roadway safety features.2 Despite these improvements, traffic fatalities remain one of the leading causes of death in the United States,3 with an estimated 32 788 such deaths in 2010.4 Thus, road traffic fatalities continue to be a significant public health concern,5,6 garnering much attention from state lawmakers.In an effort to reduce motor vehicle fatalities, states have enacted restrictions on drunk driving, implemented graduated driver’s license programs, and mandated seatbelt use and special licensing procedures for older adults. Most recently, states have focused on restricting texting while driving.7–9 Generally, states define texting as reading, manual composition, or sending of electronic communications—text messages, instant messages, or e-mails—via a portable electronic device. Portable electronic devices include mobile (i.e., cellular) phones, personal digital assistants, and laptop computers. Texting while driving is a serious threat to road safety,10–13 given that research has shown that mobile phone use is associated with impaired following distance,14 improper lane position,11,15 longer reaction times,11,14,16 and crashes,11,17 which can all lead to significant adverse public health outcomes, including death.18 Unlike talking on a mobile phone while driving, texting poses a unique threat in that it requires drivers to take their eyes off the road for several seconds at a time.14Our current understanding of the impact of texting laws on driving outcomes is limited. To our knowledge, 2 studies have empirically examined the impact of texting laws on adverse motor vehicle outcomes. The first was published by the Highway Loss Data Institute.19 It examined the relationship of collision claim frequency and texting bans in just 4 states (CA, LA, MN, and WA). The authors found that texting bans were associated with increased collision claims. They speculated that this increase might be due to drivers hiding their phones from view to avoid fines and, in so doing, taking their eyes off the road more than they did before the bans. More recently, Abouk and Adams20 published the first national-level study of texting bans’ impacts on traffic fatalities. They examined the impact of texting-while-driving bans on the occurrence of only single-vehicle, single-occupant accidents between 2007 and 2010. Their findings indicated that stronger bans that are applied to all drivers were associated with decreases in single-vehicle, single-occupant accidents.The purpose of this study is to add to the knowledge base concerning the effectiveness of texting laws, particularly by considering the varying stringency levels of these laws. Texting bans can be secondarily enforced (i.e., an officer must have another reason to stop a vehicle before citing a driver for texting while driving) or primarily enforced (i.e., an officer does not have to have another reason for stopping a vehicle). Furthermore, some states ban texting among learner’s permit holders, and some ban texting among all those aged 18 years, 21 years, or younger, and still other states ban all drivers from texting. Some states have no texting laws at all. We consider the impact of each of these policy nuances on traffic fatalities in 48 states over an 11-year period. Moreover, given that younger individuals are more likely to text while driving,21 we examine the impact of texting laws on age-specific traffic fatalities. Overall, this study will be of interest to policymakers, law enforcement personnel, and other stakeholders interested in improving roadway safety and, by extension, public health. 相似文献