全文获取类型
收费全文 | 1128篇 |
免费 | 70篇 |
专业分类
林业 | 93篇 |
农学 | 32篇 |
基础科学 | 1篇 |
244篇 | |
综合类 | 60篇 |
农作物 | 77篇 |
水产渔业 | 104篇 |
畜牧兽医 | 449篇 |
园艺 | 23篇 |
植物保护 | 115篇 |
出版年
2023年 | 19篇 |
2022年 | 31篇 |
2021年 | 57篇 |
2020年 | 49篇 |
2019年 | 42篇 |
2018年 | 55篇 |
2017年 | 38篇 |
2016年 | 48篇 |
2015年 | 29篇 |
2014年 | 47篇 |
2013年 | 65篇 |
2012年 | 65篇 |
2011年 | 104篇 |
2010年 | 62篇 |
2009年 | 43篇 |
2008年 | 67篇 |
2007年 | 70篇 |
2006年 | 54篇 |
2005年 | 44篇 |
2004年 | 50篇 |
2003年 | 37篇 |
2002年 | 33篇 |
2001年 | 8篇 |
2000年 | 15篇 |
1999年 | 4篇 |
1998年 | 2篇 |
1997年 | 5篇 |
1996年 | 5篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 5篇 |
1991年 | 3篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1986年 | 5篇 |
1985年 | 1篇 |
1984年 | 4篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 5篇 |
1980年 | 1篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1968年 | 1篇 |
1955年 | 1篇 |
排序方式: 共有1198条查询结果,搜索用时 15 毫秒
41.
Otmar Spring Mark Bachofer Marco Thines Alexandra Riethmüller Markus Göker Franz Oberwinkler 《European journal of plant pathology / European Foundation for Plant Pathology》2006,114(3):309-315
Sequence parts of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA were analysed to screen for the intraspecific
variability of a non-coding genomic region in 15 Plasmopara halstedii populations of different pathotype and geographic origin. Samples revealed uniformity in a ca. 790 Bp fragment comprising
of the ITS-1, 5.8S and front parts of the ITS-2. In contrast, clear differences were found in a ca. 810 Bp fragment of the
ITS-2 thus allowing differentiation between populations of pathotype 100, 310 and 330 and a group of populations representing
pathotypes 700, 701, 703, 710 and 730. Samples of pathotypes 700 to730 originated from Slovakia, France, and Germany, but
were uniform in both ITS sequence parts, thus indicating very recent origin of these highly aggressive physiological races.
The potential use of ITS sequences for pathotype differentiation and phylogenetic studies in P. halstedii is discussed. 相似文献
42.
Pietro Rocculi Emiliano Cocci Santina Romani Giampiero Sacchetti Marco Dalla Rosa 《Postharvest Biology and Technology》2009,51(3):371-377
The effects of both 1-MCP treatment of pineapples and packaging of their fresh-cut products with an alternative modified atmosphere (MA: 86.13 kPa N2O, 10.13 kPa O2 and 5.07 kPa CO2) on physiological and quality changes of these minimally processed products were investigated. Fresh-cut fruit treated or not with 1-MCP were packed in Air or in MA and were stored at 4 °C for 10 d. The following parameters were monitored during storage: ripening index; O2, CO2 and C2H4 in the package headspace; firmness and colour. Microbial spoilage of MP pineapple samples was also investigated and a mathematical model based on the Zwietering modified Gompertz equation was used to obtain growth parameters of mesophilic bacteria, yeasts and moulds.The results showed that 1-MCP treatment and MAP in a N2O enriched atmosphere had a positive combined effect on the inhibition of respiration and ethylene production of fresh-cut pineapple and on its softening delay, confirming previous findings about 1-MCP and N2O preservative effects on fresh-cut fruit quality. This combined effect was not extended to the ripening index and colour maintenance, as MAP at 86.13 kPa of N2O did not add any benefit to that of the 1-MCP treatment. From a microbiological point of view, N2O MAP extended the shelf-life of the products of 3–4 d by increasing the lag phase of microbial growth. 相似文献
43.
Isabel Guadano Procesi Azzurra Carnio Federica Berrilli Margherita Montalbano Di Filippo Alessia Scarito Cristina Amoruso Marco Barni Marco Ruffini Giulia Barlozzari Manuela Scarpulla Claudio De Liberato 《Zoonoses and public health》2022,69(1):46-54
Giardia duodenalis is the most common intestinal protozoan in humans and animals worldwide, including eight morphologically identical assemblages, infecting pets, livestock, wildlife and human beings. Assemblages A and B are those with the higher zoonotic potential, and they have been detected in several mammals other than humans; the others (C to H) show a higher host specificity. Cats can harbour both the specific Assemblage F and the zoonotic ones A and B. Several studies have been carried out on G. duodenalis genotypes in cats; however, the role of this species in the epidemiology of giardiasis is still poorly understood. In this scenario, the present study carried out the detection and genetic characterization at sub-assemblage level of G. duodenalis from colony stray cats in central Italy. In the period 2018–2019, 133 cat faecal samples were analysed for the presence of G. duodenalis cysts by a direct immunofluorescence assay. Positive samples were subsequently subjected to molecular analyses for assemblage/sub-assemblage identification. Forty-seven samples (35.3%) were positive for G. duodenalis cysts by immunofluorescence. G. duodenalis DNA was amplified at SSU-rDNA locus from 39 isolates: 37 were positive for zoonotic Assemblage A and 2 showed a mixed infection (A + B). Positive results for the β-giardin gene were achieved for 25 isolates. Sequence analysis revealed 16 isolates belonging to Sub-assemblage AII and 8 to Sub-assemblage AIII. One isolate resulted as ambiguous AI/AIII. Large sequence variability at the sub-assemblage level was detected, with several double peaks and mutations, making complex a proper isolate allocation. When compared with previous studies, the 35.3% prevalence of G. duodenalis in cats reported in the present article was surprisingly high. Moreover, all positive cats resulted to be infected with zoonotic assemblages/sub-assemblages, thus indicating stray cats as a possible source of human giardiasis and highlighting the sanitary relevance of cat colonies in the study area. 相似文献
44.
Fabio Orlandi Tommaso Bonofiglio Luigia Ruga Carlo Sgromo Bruno Romano Marco Fornaciari 《Annals of Forest Science》2007,64(5):557-568
Phenological stages are the result of biorhythms and environmental factors, these last are probably the same ones that caused, during evolution, adjustments of the species to different climate. The present study was carried out in a Phenological Garden located in central Italy (Perugia, Umbria Region) which contains indicator species, common to all International Phenological Gardens. The aim of this study was to determine and analyse the average trends of development of eight plant species and their phenological adjustment to the Mediterranean environment, over a nine-year period (1997–2005). The results of the statistical analyses show a strong relationship between the temperature trends and vegetative seasonal evolutions interpreted by phenological data for all the species considered. Moreover, it was demonstrated that the plants studied may approach or close completely the timing gaps eventually created during the first phenological phases, adjusting thus the beginning of subsequent phenophases. 相似文献
45.
Joanne M.?Thwaites Roberta L.?FarrellEmail author Kunio?Hata Peter?Carter Marco?Lausberg 《Journal of Wood Science》2004,50(5):459-465
Supply of clear, unstained logs from an export country is important economically as well as in reducing the biosecurity risk to an importing country such as Japan. Although conditions found within the holds of ships containing logs are thought to be ideal for rapid colonization of sapstain fungi, no research has been conducted. Research-focussed log export trials were designed to determine the extent of sapstain colonisation at specific points in the processing of logs from harvesting to arrival at the export destination. Two trials were established, in the austral summer and winter, in which mature Pinus radiata logs were harvested in New Zealand and shipped to export ports in Japan. Data loggers placed above and below deck of the ships recorded microclimatic conditions. Nine species of sapstain fungi were isolated from logs during the summer trial; the most common species isolated were Ophiostoma floccosum, Ophiostoma querci, and Ophiostoma setosum. In contrast, ten sapstain species were detected during the winter trial, with Sphaeropsis sapinea, O. querci, O. floccosum, and O. setosum most commonly isolated. This research was the first successful attempt at measuring visual sapstain development and isolating sapstain fungi from the time of harvesting to arrival at an export destination. 相似文献
46.
MULTIDETECTOR‐ROW COMPUTED TOMOGRAPHY PATTERNS OF BRONCHOESPHAGEAL ARTERY HYPERTROPHY AND SYSTEMIC‐TO‐PULMONARY FISTULA IN DOGS 下载免费PDF全文
Gianluca Ledda Marco Caldin Giorgia Mezzalira Giovanna Bertolini 《Veterinary radiology & ultrasound》2015,56(4):347-358
Anomalies involving arterial branches in the lungs are one of the causes of hemoptysis in humans and dogs. Congenital and acquired patterns of bronchoesophageal artery hypertrophy have been reported in humans based on CT characteristics. The purpose of this retrospective study was to describe clinical, echocardiographic, and multidetector computed tomography features of bronchoesophageal artery hypertrophy and systemic‐to‐pulmonary arterial communications in a sample of 14 dogs. Two main vascular patterns were identified in dogs that resembled congenital and acquired conditions reported in humans. Pattern 1 appeared as an aberrant origin of the right bronchoesophageal artery, normal origin of the left one, and enlargement of both the bronchial and esophageal branches that formed a dense network terminating in a pulmonary artery through an orifice. Pattern 2 appeared as a normal origin of both right and left bronchoesophageal arteries, with an enlarged and tortuous course along the bronchi to the periphery of the lung, where they communicated with subsegmental pulmonary arteries. Dogs having Pattern 1 also had paraesophageal and esophageal varices, with the latter being confirmed by videoendoscopy examination. Authors conclude that dogs with Pattern 1 should be differentiated from dogs with other congenital vascular systemic‐to‐pulmonary connections. Dogs having Pattern 2 should be evaluated for underlying pleural or pulmonary diseases. Bronchoesophageal artery hypertrophy can be accompanied by esophageal venous engorgement and should be included in the differential diagnosis for esophageal and paraesophageal varices in dogs. 相似文献
47.
Sara Canal Massimo Baroni Cristian Falzone Giulia M. De Benedictis Marco Bernardini 《The Canadian veterinary journal. La revue veterinaire canadienne》2015,56(12):1261-1265
Two young dogs were evaluated for an acute onset of abnormal head posture and eye movement. Neurological examination was characterized mostly by permanent neck extension, abnormalities of pupils, and eye movement. A mesencephalic mass lesion was detected on magnetic resonance imaging in both cases. Neurophysiological pathways likely responsible for this peculiar clinical presentation are discussed. 相似文献
48.
Marco Pietra Renato Giulio Zanoni Angelo Peli Barbara Brunetti Nikolina Linta Ombretta Capitani Giuseppe Spinella 《Irish veterinary journal》2015,69(1):12
Background
The authors report the first case of feline gastric actinomycosis associated with infection by Actinomyces hordeovulneris.Case presentation
A 4-year-old, neutered male, semi-feral European cat, with a 1 year history of chronic vomiting, was referred to the clinic. Abdominal ultrasound examination identified a hypoechoic focal transmural thickening with loss of normal wall layering and hyperechoic speckles at the gastric body. Initial gastroscopic examination showed a tumour-like gastric mass with an ulcerated depression at the level of the greater curvature. Histologic examination of endoscopic biopsy specimens was consistent with a severe lymphoplasmacytic gastritis. After 2 months, due to persistence of abdominal discomfort, surgical exploration and intraoperative sampling of gross abnormalities was recommended. Full thickness gastric wall biopsies, and fine needle aspiration of the gastric thickening and gastric lymph node, were performed. Histopathological examination identified a transmural pyogranulomatous gastritis. Aspirate samples of the gastric wall cultured positive, with colony morphology, biochemical testing and PCR of the 16 s rRNA gene compatible with Actinomyces hordeovulneris. After 4 months of treatment with cefovecin (8 mg/kg subcutaneously every 14 days), the vomiting completely resolved, as well as the ultrasonographic gastric alteration.Conclusion
This case report of feline gastric actinomycosis, caused by Actinomyces hordeovulneris, suggests that gastric bacterial infection should be considered in cases of focal gastric wall thickening associated with chronic vomiting in the cat, which may otherwise closely resemble neoplastic disease. Once a diagnosis of actinomycosis was obtained, a correct treatment with antibiotic therapy can resolve it.49.
Clinical comparison of two regimens of lidocaine infusion in horses undergoing laparotomy for colic 下载免费PDF全文
Sara Nannarone Alessia Cenani Rodolfo Gialletti Marco Pepe 《Veterinary anaesthesia and analgesia》2015,42(2):150-156
ObjectiveTo compare, in horses undergoing laparotomy for colic, the effects of administering or not administering a loading intravenous (IV) bolus of lidocaine prior to its constant rate infusion (CRI). Effects investigated during isoflurane anaesthesia were end-tidal isoflurane concentration (Fe’ISO), cardiovascular function, anaesthetic stability and the quality of recovery.Study designProspective, randomized clinical study.AnimalsThirty-six client-owned horses.MethodsHorses were assigned randomly to receive lidocaine as a CRI (50 μg kg−1 minute−1) either preceded (LB) or not preceded (L) by a loading dose (1.5 mg kg−1 IV over 15 minutes). Lidocaine infusion (LInf) was started (T0) within 20 minutes after induction of general anaesthesia and discontinued approximately 30 minutes before the end of surgery. Anaesthetic depth, Fe’ISO, intra-operative physiological parameters and quality of recovery were assessed or measured. Data were analysed using one-way anova, t-test, Fisher test, Wilcoxon and Kruskal–Wallis tests as appropriate (p < 0.05).ResultsMean ± SD Fe’ISO was 1.21 ± 0.08% in group LB and 1.23 ± 0.06% in group L. Heart rate was significantly higher in group L than in group LB at times T5-T15, T25, T35 and T95. No difference was found between groups in other measured physiological values, nor in any measure taken to improve these parameters. Recovery phase was comparable and satisfactory in all but one full term pregnant horse in group L which fractured a femur during recovery.ConclusionPreloading with a lidocaine bolus prior to a CRI of lidocaine did not influence isoflurane requirements, cardiopulmonary effects (other than a reduction in heart rate at some time points) or recovery compared to no preloading bolus.Clinical relevanceA loading dose of lidocaine prior to CRI does not confer any advantage in horses undergoing laparotomy for colic. 相似文献
50.