全文获取类型
收费全文 | 950篇 |
免费 | 95篇 |
专业分类
林业 | 70篇 |
农学 | 53篇 |
基础科学 | 4篇 |
205篇 | |
综合类 | 23篇 |
农作物 | 61篇 |
水产渔业 | 110篇 |
畜牧兽医 | 447篇 |
园艺 | 16篇 |
植物保护 | 56篇 |
出版年
2024年 | 3篇 |
2023年 | 17篇 |
2022年 | 25篇 |
2021年 | 48篇 |
2020年 | 60篇 |
2019年 | 59篇 |
2018年 | 55篇 |
2017年 | 52篇 |
2016年 | 53篇 |
2015年 | 45篇 |
2014年 | 43篇 |
2013年 | 42篇 |
2012年 | 78篇 |
2011年 | 67篇 |
2010年 | 51篇 |
2009年 | 34篇 |
2008年 | 46篇 |
2007年 | 56篇 |
2006年 | 35篇 |
2005年 | 23篇 |
2004年 | 29篇 |
2003年 | 33篇 |
2002年 | 23篇 |
2001年 | 19篇 |
2000年 | 22篇 |
1999年 | 8篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 1篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1980年 | 1篇 |
排序方式: 共有1045条查询结果,搜索用时 46 毫秒
991.
Cabral Bárbara Bortolin Raul Hernandes Gonçalves Tays Amanda Felisberto Maciel Priscilla Maria Pereira de Arruda Alinne Villar de Carvalho Thais Gomes Abboud Kahlile Youssef Alves Jovelina Samara Ferreira Cordeiro Lucimara M. C. de Medeiros Isac Almeida de Rezende Adriana Augusto Zucolotto Silvana Maria 《Plant foods for human nutrition (Dordrecht, Netherlands)》2021,76(4):466-471
Plant Foods for Human Nutrition - Passiflora edulis fo. flavicarpa (Passifloraceae) is popularly known as yellow passion fruit and its fruit peels are considered a rich by-product in bioactive... 相似文献
992.
Enry Garcia da Silva Lynne S. Sandmeyer Juliet R. Gionfriddo Fabiano Montiani‐Ferreira Paula D. Galera 《Veterinary ophthalmology》2013,16(3):175-179
Purpose The ability of human newborns to produce tears has been a subject of controversy in the literature since the mid‐20th century, and there has been considerable debate as to whether they are able to produce tears. Recently, it was established that total tear secretion (reflex + basal) in full‐term infants is similar to those of adults whereas both reflex and basal tear production is reduced in premature babies. The objectives of this study were to assess whether newborn dogs have measurable aqueous tear production at the fourth week of life and to evaluate a modified Schirmer tear test (mSTT) as a useful method for measuring neonatal tear production in dogs. Methods Thirty four‐week‐old healthy puppies from six litters were evaluated. A control group was composed of 10 normal adult dogs. The mSTT strips were obtained by cutting a 5 mm‐wide strip in half (making two 2.5 mm‐wide strips). The mSTT1 was performed in puppies and adult dogs. Values were compared using t‐tests. Results In neonates, the average value for the mSTT1 was 13.6 ± 3.07 (range = 7–19 mm/min), which was significantly lower in neonates than in adult dogs (23.25 ± 3.5, range = 17–30 mm/min, P < 0.0001). Conclusions Canine neonates do produce tears by the fourth week of life, which can be successfully measured with the mSTT. This report established for the first time that canine neonates have significantly reduced total (reflex + basal) tear secretion compared to adults. 相似文献
993.
Catarina Sofia Aluai-Cunha Catarina Alves Pinto Isabel Alexandra Duarte Ferreira Lopes Correia Cláudia Alexandra dos Reis Serra Andreia Alexandra Ferreira Santos 《Veterinary and comparative oncology》2023,21(2):166-183
Cancer is a substantial global health problem both in humans and animals with a consistent increase in mortality and incidence rate. The commensal microbiota has been involved in the regulation of several physiological and pathological processes, both within the gastrointestinal system and at distant tissue locations. Cancer is not an exception, and different aspects of the microbiome have been described to have anti- or pro-tumour effects. Using new techniques, for example high-throughput DNA sequencing, microbial populations of the human body have been largely described and, in the last years, studies more focused on companions' animals have emerged. In general, the recent investigations of faecal microbial phylogeny and functional capacity of the canine and feline gut have shown similarities with human gut. In this translational study we will review and summarize the relation between the microbiota and cancer, in humans and companion animals, and compare their resemblance in the type of neoplasms already studied in veterinary medicine: multicentric and intestinal lymphoma, colorectal tumours, nasal neoplasia and mast cell tumours. In the context of One Health, microbiota and microbiome integrative studies may contribute to the understanding of the tumourigenesis process, besides offering an opportunity to develop new diagnostics and therapeutic biomarkers both for veterinary and human oncology. 相似文献
994.
995.
Corrêa TG Ferreira JM Riet-Correa G Ruas JL Schild AL Riet-Correa F Guimarães A Felippe-Bauer ML 《Veterinary parasitology》2007,145(1-2):181-185
The incidence of seasonal dermatitis was studied in a Hampshire Down flock on a farm in southern Brazil. Epidemiological data, clinical signs and macroscopic pathology were obtained by visiting the farm. Histological lesions were studied in skin biopsies of affected sheep. Biting insects were collected from January to April 2005 in an attempt to identify the etiological agent of the disease. Disease prevalence was 40%; the age of the affected animals was variable. Disease occurred from December to March, some animals had lesions for the entire year. Clinical signs include pruritus on the ears, around the eyes and ventral abdomen. Initially erythema and small red papules were seen, followed by alopecia and crust formation. Histologically the lesions were characterized by perivascular eosinophilic dermatitis. Hyperkeratosis and acanthosis were observed in the chronic lesions. Both Anopheles albitarsis and Culicoides insignis were captured during the study. C. insignis bites caused pruritus in sheep. Both types of insects were caught when they approached the sheep baits approximately 30min after sunset. Results suggested that the disease occurred as a result of an immediate hypersensitivity reaction to C. insignis. 相似文献
996.
Gomes AH Ferreira IM Lima ML Cunha EA Garcia AS Araújo MF Pereira-Chioccola VL 《Veterinary parasitology》2007,144(3-4):234-241
Leishmaniases are endemic in many countries, mainly in rural areas. In Brazil, Leishmania infection is responsible for many cases of Leishmaniases, including recent reports in urban regions. Despite their sensitivity, traditional serological and parasitological methods for detecting Leishmaniases have proven inadequate for species discrimination. This study aimed to identify Leishmania species in biological samples by a fast methodology, avoiding "in vitro" cultivation. Knowledge of the Leishmania species is an important tool in regions where both New World visceral leishmaniasis (VL) and cutaneous leishmaniasis (CL) are prevalent. As these new foci appear in areas not traditionally endemic for VL, the main problem is to distinguish between true autochthonous infections and infections acquired in other well-known endemic areas. Since, domestic dogs are known to be the main VL and CL reservoir, they are regularly investigated in endemic areas to prevent, principally, severe and often fatal VL in humans. However, several infected dogs present no clinical signs or clinical signs similar to other canine diseases. Here, we evaluated the ability of PCR to diagnose VL and distinguish L. (L.) chagasi from other Leishmania species in domestic dogs. Samples from 114 dogs from 30 cities (Sao Paulo, Brazil) were divided into two groups: 44 symptomatic and 70 asymptomatic. They were assayed by parasitological methods (culture and microscopic examination) and PCR to determine L. (L.) chagasi, L. (V.) braziliensis; and in some cases, Leishmania spp. Parasitological tests and PCR-L. chagasi were concordant in 105 samples (92%). VL was confirmed in 49 dogs, while 56 had negative results. Of the 114 samples, 9 had discordant results, but were further tested by PCR-Leishmania spp. with positive results. VL was also confirmed in 4 dogs having negative parasitological tests and positive PCR-L. chagasi. Consequently, this PCR was positive for 100% (53/49) of dogs with parasites detected in parasitological tests. Also, PCR demonstrated high specificity detecting 61 dogs negative for VL. Leishmania infection was negative in 56 dogs, and 5 with positive culture and PCR-Leishmania spp. had CL since they were positive in PCR-L. braziliensis. This study shows the importance of including PCR in diagnosis of Leishmaniases by differential diagnosis contributing to the surveillance and control of VL programs. 相似文献
997.
Mello Raquel Rodrigues Costa Sinedino Letícia Del-Penho Ferreira Joaquim Esquerdo de Sousa Sabrina Luzia Gregio de Mello Marco Roberto Bourg 《Tropical animal health and production》2020,52(1):273-281
Tropical Animal Health and Production - The objective of this study was to investigate the relationship among functional traits (age at first calving (AFC), calving interval (CI), reproductive... 相似文献
998.
Pinheiro Jessyca Karen Ferreira Raimundo Ribeiro Gonzaga Neto Severino Signoretti Ricardo Dias Henriques Lara Toledo de Oliveira Juliana Silva 《Tropical animal health and production》2020,52(3):1309-1314
Tropical Animal Health and Production - The present study aimed to evaluate the degradation dynamics of high-quality tropical forage according to the levels of nitrogen supplementation. In this... 相似文献
999.
da Silva Luiza Lopes Silveira Maiele Dornelles da Costa Garcia Carla Augusta Sassi Grudzinski Patrícia Bencke Martins Charles Ferreira Nardi Nance Beyer 《Veterinary research communications》2020,44(2):41-49
Veterinary Research Communications - Mesenchymal stromal cells (MSCs) have attracted great attention for therapeutic applications. Since cells derived from different tissues have different... 相似文献
1000.
Rennan Herculano Rufino Moreira Jorge Yair Pérez Palencia Vitor Hugo Cardoso Moita Luciano Sales Santiago Caputo Alysson Saraiva Inês Andretta Rony Antônio Ferreira Márvio Lobão Teixeira de Abreu 《Journal of animal physiology and animal nutrition》2020,104(2):657-666
The objective of the study was to evaluate the effects of litter size and supplementation of functional amino acids on the piglet birth weight variability through of a systematic review and meta-analysis. PubMed, ISI Web of Science, Science Direct, Scopus and SciELO are the main used databases and were searched in January 2019 by using the following keywords and their combinations: within-litter birth, weight variability, piglets, litter size, sow, amino acids, gestation, uniformity, CV and/or SD. Of the 64 pre-selected articles, only articles presenting the coefficients of variation and/or standard deviations according to the litter size and different levels of amino acid supplementation in the sow diets during gestation were selected. The average birth weights of total and live piglets were 43% lower in litters from sows with high prolificacy than those from sows with low prolificacy. The weight variability was affected by high prolificacy sows, with increases of 4.04% and 4.54% in the coefficients of variation of total and born alive piglets respectively (p = .074; p = .009). The standard deviation increased by 180 g in born alive piglets to high prolificacy sows. The coefficients of variation of total and live piglets born from high prolificacy sows showed an increase of 4.04% and 4.54% respectively (p = .07; p < .05). There was a tendency for reduced weight variability with amino acids supplementation when considering the standard deviation of total born (p = .072). However, reproductive performance was not significantly influenced (p > .05). In conclusion, the average litter weight and the number of piglets born influence weight variability. Amino acids supplementation may reduce the birth weight variability between piglets. However, this effect depends on the amino acid used, the levels of supplementation and on other factors not completely addressed in this study. Thus, more research is necessary to fully elucidate this topic. 相似文献