全文获取类型
收费全文 | 3630篇 |
免费 | 368篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 27篇 |
儿科学 | 118篇 |
妇产科学 | 102篇 |
基础医学 | 345篇 |
口腔科学 | 242篇 |
临床医学 | 295篇 |
内科学 | 846篇 |
皮肤病学 | 50篇 |
神经病学 | 185篇 |
特种医学 | 93篇 |
外科学 | 560篇 |
综合类 | 103篇 |
预防医学 | 379篇 |
眼科学 | 159篇 |
药学 | 298篇 |
中国医学 | 13篇 |
肿瘤学 | 198篇 |
出版年
2023年 | 49篇 |
2022年 | 149篇 |
2021年 | 194篇 |
2020年 | 129篇 |
2019年 | 174篇 |
2018年 | 214篇 |
2017年 | 137篇 |
2016年 | 143篇 |
2015年 | 129篇 |
2014年 | 194篇 |
2013年 | 222篇 |
2012年 | 286篇 |
2011年 | 274篇 |
2010年 | 168篇 |
2009年 | 111篇 |
2008年 | 170篇 |
2007年 | 150篇 |
2006年 | 140篇 |
2005年 | 159篇 |
2004年 | 112篇 |
2003年 | 82篇 |
2002年 | 83篇 |
2001年 | 32篇 |
2000年 | 46篇 |
1999年 | 49篇 |
1998年 | 31篇 |
1997年 | 23篇 |
1996年 | 22篇 |
1995年 | 18篇 |
1994年 | 12篇 |
1993年 | 15篇 |
1992年 | 21篇 |
1991年 | 33篇 |
1990年 | 19篇 |
1989年 | 29篇 |
1988年 | 22篇 |
1987年 | 33篇 |
1986年 | 20篇 |
1985年 | 18篇 |
1984年 | 17篇 |
1982年 | 6篇 |
1981年 | 8篇 |
1980年 | 5篇 |
1979年 | 9篇 |
1978年 | 9篇 |
1971年 | 4篇 |
1969年 | 3篇 |
1968年 | 4篇 |
1967年 | 4篇 |
1966年 | 4篇 |
排序方式: 共有4013条查询结果,搜索用时 15 毫秒
21.
H H Lim Z Domala S Joginder S H Lee C S Lim C M Abu Bakar 《Occupational and environmental medicine》1984,41(4):445-449
A study was carried out to determine the health effects of rice husk dust in Malaysian rice millers. The study population consisted of 122 male Malay workers from three rice mills, with 42 controls of similar age, sex, ethnic group, and agricultural work background. Interviews using standardised questionnaires, physical examination, total and differential white cell counts, chest radiographs, and lung function tests were performed on each of the millers and the controls. Environmental dust monitoring was also carried out in the three rice mills. Clinical, haematological, and radiological findings suggest that a distinct clinical syndrome seems to be associated with exposure to rice husk dust. The manifestations of this "rice millers' syndrome" include acute and chronic irritant effects affecting the eyes, skin, and upper respiratory tract; allergic responses such as nasal catarrh, tightness of chest, asthma, and eosinophilia; and radiological opacities in the chest, probably representing early silicosis or extrinsic allergic alveolitis. 相似文献
22.
Suraj Suresh Mohammad Siddiqui Mouhanna Abu Ghanimeh Jessica Jou Stephen Simmer Vivek Mendiratta Sarah Russell Mustafa Al-Shammari Abigail Chatfield Eva Alsheik Duyen Dang Jeffrey Genaw Tobias Zuchelli 《Obesity research & clinical practice》2021,15(2):172-176
BackgroundAlthough recent studies have shown an association between obesity and adverse coronavirus disease 2019 (COVID-19) patient outcomes, there is a paucity in large studies focusing on hospitalized patients. We aimed to analyze outcomes associated with obesity in a large cohort of hospitalized COVID-19 patients.MethodsWe performed a retrospective study at a tertiary care health system of adult patients with COVID-19 who were admitted between March 1 and April 30, 2020. Patients were stratified by body mass index (BMI) into obese (BMI ≥ 30 kg/m 2) and non-obese (BMI < 30 kg/m 2) cohorts. Primary outcomes were mortality, intensive care unit (ICU) admission, intubation, and 30-day readmission.ResultsA total of 1983 patients were included of whom 1031 (51.9%) had obesity and 952 (48.9%) did not have obesity. Patients with obesity were younger (P < 0.001), more likely to be female (P < 0.001) and African American (P < 0.001) compared to patients without obesity. Multivariable logistic models adjusting for differences in age, sex, race, medical comorbidities, and treatment modalities revealed no difference in 60-day mortality and 30-day readmission between obese and non-obese groups. In these models, patients with obesity had increased odds of ICU admission (adjusted OR, 1.37; 95% CI, 1.07?1.76; P = 0.012) and intubation (adjusted OR, 1.37; 95% CI, 1.04?1.80; P = 0.026).ConclusionsObesity in patients with COVID-19 is independently associated with increased risk for ICU admission and intubation. Recognizing that obesity impacts morbidity in this manner is crucial for appropriate management of COVID-19 patients. 相似文献
23.
Fatina W. Dahadhah Mayyas Saleh Jaweesh Mazhar Salim Al Zoubi Manal Issam Abu Alarjah Mohamad Eid Hammadeh Houda Amor 《Andrologia》2021,53(8):e14139
Male infertility is a multifactorial condition associated with different genetic abnormalities in at least 15%–30% of cases. The purpose of this study was to identify suspected correlations between infertility and polymorphisms in mitochondrial NADH dehydrogenase subunits 3 and 4L (MT-ND3 and MT-ND4L) in subfertile male spermatozoa. Sanger sequencing of the mitochondrial DNA target genes was performed on 68 subfertile and 44 fertile males. Eight single nucleotide polymorphisms (SNPs) in MT-ND3 (rs2853826, rs28435660, rs193302927, rs28358278, rs41467651, rs3899188, rs28358277 and rs28673954) and seven SNPs in MT-ND4L (rs28358280, rs28358281, rs28358279, rs2853487, rs2853488, rs193302933 and rs28532881) were detected and genotyped. The genotypes and allele frequencies of the study population have shown a lack of statistically significant association between MT-ND3 and MT-ND4L SNPs and male infertility. However, no statistically significant association was found between the asthenozoospermia, oligozoospermia, teratozoospermia, asthenoteratozoospermia, oligoasthenoteratozoospermia and oligoteratozoospermia subgroups of subfertile males. However, rs28358278 genotype of the MT-ND3 gene was reported in the subfertile group but not in the fertile group, which implies a possible role of this SNP in male infertility. In conclusion, the investigated polymorphic variants in the MT-ND3 and MT-ND4L genes did not show any significant association with the occurrence of male infertility. Further studies are required to evaluate these findings. Moreover, the subfertile individuals who exhibit a polymorphism at rs28358278 require further monitoring and evaluation. 相似文献
24.
BackgroundThere has been increasing uptake of minimally invasive pancreatoduodenectomy during the past decade, but it remains a highly specialized procedure as benefits over open pancreatoduodenectomy remain contentious. This study aimed to evaluate current evidence on minimally invasive pancreatoduodenectomy versus open pancreatoduodenectomy in terms of impact of center volume on outcomes.MethodsA systematic review of articles on comparative cohort and registry studies on minimally invasive pancreatoduodenectomy versus open pancreatoduodenectomy published until 31st December 2019 were identified, and meta-analyses were performed. Primary endpoints were International Study Group on Pancreatic Fistula grade B/C postoperative pancreatic fistula and 30-day mortality.ResultsAfter screening 7,390 studies, 43 comparative cohort studies (8,755 patients) with moderate methodological quality and 3 original registry studies (43,735 patients) were included. For the cohort studies, the median annual hospital minimally invasive pancreatoduodenectomy volume was 10. No significant differences were found in grade B/C postoperative pancreatic fistula (odds ratio: 0.98, 95% confidence interval: 0.78–1.23) or 30-day mortality (odds ratio: 1.14, 95% confidence interval: 0.65–2.01) between minimally invasive pancreatoduodenectomy when compared with open. No publication biases were present and meta-regression identified no confounding for grade B/C postoperative pancreatic fistula, center volume or 30-day mortality. Minimally invasive pancreatoduodenectomy was only strongly associated with significantly lower rates of postoperative pulmonary complications and surgical site infection, shorter length of stay, and significantly higher rates of R0 margin resections.ConclusionMinimally invasive pancreatoduodenectomy remains noninferior to open pancreatoduodenectomy for grade B/C postoperative pancreatic fistula but is strongly associated with significantly lower rates of postoperative pulmonary complications and surgical site infection. Minimally invasive pancreatoduodenectomy can be adopted safely with good outcomes irrespective of annual center resection volume. 相似文献
25.
26.
27.
A retrospective study of anaemia in pregnancy in rural Kelantan was conducted. The study sample consist of 9,860 mothers who had antenatal care at one of the 102 rural health clinics selected and had delivered a live baby. Anaemia in pregnancy was determined by reviewing the antenatal records for the haemoglobin level recorded at the first and last antenatal visit. Estimation of haemoglobin was done either by photocalorimetric methods or the Sahli's method in these rural clinics. At the time of booking, 47.5% of the mothers were anaemic by WHO criteria (Hb < 11.0 g/dl), with 1.9% having less than 9.0 g/dl. Age of mother, parity and late gestational age at the first antenatal visit were associated with anaemia during pregnancy at the time of booking. However, practise of contraception by the mother did not show any association with anaemia in pregnancy. There were 594 mothers (6.0%) who delivered a baby weighing less than 2.5 kg. There was no association between the low birth weight of the child and the status of anaemia in the mother at the last antenatal visit. 相似文献
28.
Food consumption of 50 female students in Universiti Kebangsaan Malaysia was recorded for 7 days. Foods and drinks most frequently consumed were selected for analysis of iron, zinc, copper and lead content. The mean daily intakes of energy, protein, carbohydrate and fat among the students are 6.5±1.4 MJ (1550±335 kcal), 59.8±18.5g, 227.1±54.6 g and 46.0±11.5 g respectively. This diet contributed 19.6-6.4 mg Fe, 7.0-2.0 mg Zn and 1.6-0.6 mg Cu per day which were lower than the Malaysian RDA for Fe and US RDA for Zn, while Cu is within the recommended range. The main sources of these minerals in the student's diet were rice, rice products, meat and animal products. Lead concentration in the diet (134±77 ug/day) is below the acceptable daily intake (ADI) value suggested by Codex Alimentarius Commission (1984). This study indicated concern regarding the low intake of the essential trace elements on long term basis among the students. 相似文献
29.
OBJECTIVE: The purpose of this study was to assess the safety and feasibility of MR-guided percutaneous nephrostomy of the nondilated contrast-enhanced upper urinary tract in a porcine model. SUBJECTS AND METHODS: Six MR-guided percutaneous nephrostomies of the nondilated upper urinary tract were performed in four domestic farm pigs (body weight range, 20-25 kg) using a 0.2-T system. Ten minutes after IV administration of 0.2 mmol/kg of gadodiamide and 0.4 mg/kg of furosemide, a fast T1-weighted sequence was used to guide insertion of an 18-gauge MR-compatible needle into a predetermined calix. After confirmation of needle position using a turbo spin-echo T1-weighted sequence, a 0.035-inch catheter coated with superparamagnetic iron oxide was inserted during MR monitoring. Insertion was followed by tract dilatation and insertion of a 4-French sheath. The final position of the sheath was confirmed by injection of diluted superparamagnetic iron oxide into the collecting system. RESULTS: Needle insertion was successful for all six procedures, with no complications. Instrumentation time ranged from 4 to 13 min (mean, 6+/-4 min). Sheath placement was successful in five of six kidneys. Placement time ranged from 6 to 28 min (mean, 16+/-9 min). CONCLUSION: MR-guided percutaneous nephrostomy of the nondilated contrast-enhanced upper urinary tract in a porcine model is feasible and safe. 相似文献
30.
Congenital diaphragmatic hernia through the foramen of Bochdalek may present after infancy. A 21/2-year-old Malay girl presented with acute respiratory distress. Chest examination showed reduced chest expansion and decreased breath sounds on the left side. Chest radiograph showed a large "cyst" in the left chest, which was thought to be a lung cyst under tension. Tube thoracostomy resulted in clinical improvement. Results of a barium study showed that the cyst perforated by the thoracostomy tube was the stomach, which had herniated through a Bochdalek diaphragmatic defect. Surgical repair of the diaphragmatic defect and closure of the perforated stomach was performed successfully. Congenital diaphragmatic hernia should be included in the differential diagnosis of respiratory distress in young children. Nasogastric tube placement must be considered as an early diagnostic or therapeutic intervention when the diagnosis is suspected. 相似文献