全文获取类型
收费全文 | 2561篇 |
免费 | 234篇 |
专业分类
林业 | 10篇 |
农学 | 10篇 |
基础科学 | 3篇 |
45篇 | |
综合类 | 14篇 |
农作物 | 14篇 |
水产渔业 | 17篇 |
畜牧兽医 | 2648篇 |
园艺 | 2篇 |
植物保护 | 32篇 |
出版年
2024年 | 2篇 |
2023年 | 53篇 |
2022年 | 2篇 |
2021年 | 6篇 |
2020年 | 96篇 |
2019年 | 6篇 |
2018年 | 65篇 |
2017年 | 70篇 |
2016年 | 53篇 |
2015年 | 74篇 |
2014年 | 110篇 |
2013年 | 130篇 |
2012年 | 77篇 |
2011年 | 86篇 |
2010年 | 82篇 |
2009年 | 89篇 |
2008年 | 76篇 |
2007年 | 50篇 |
2006年 | 39篇 |
2005年 | 29篇 |
2004年 | 61篇 |
2003年 | 56篇 |
2002年 | 65篇 |
2001年 | 61篇 |
2000年 | 56篇 |
1999年 | 67篇 |
1998年 | 103篇 |
1997年 | 105篇 |
1996年 | 83篇 |
1995年 | 79篇 |
1994年 | 73篇 |
1993年 | 93篇 |
1992年 | 106篇 |
1991年 | 81篇 |
1990年 | 92篇 |
1989年 | 76篇 |
1988年 | 69篇 |
1987年 | 77篇 |
1986年 | 34篇 |
1985年 | 48篇 |
1984年 | 34篇 |
1983年 | 52篇 |
1982年 | 19篇 |
1981年 | 1篇 |
1980年 | 4篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1974年 | 1篇 |
1968年 | 1篇 |
排序方式: 共有2795条查询结果,搜索用时 15 毫秒
51.
MARY ANN NIEVES DVM MS PATRICIA HARTWIG DVM JOANN M. KINYON BS MS DEAN H. RIEDESEL DVM PhD Diplomate ACVA 《Veterinary surgery : VS》1997,26(1):26-32
Objective — This study evaluates the association between dental procedures and bacteremia in dogs, including a comparison of bacteria isolated from plaque and blood, severity of the bacteremia versus the severity of dental disease, and the longevity of bacteremia.
Study Design — Bacteria cultured from the blood over time were compared with those isolated from the plaque and crevicular fluid and in relation to severity of dental disease.
Animals or Sample Population — Twenty adult greyhounds.
Methods — Blood samples were collected for culture before induction of general anesthesia, immediately after intubation, 20 minutes after initiation of the dental procedure, and at 10-minute intervals until 10 minutes after the dental procedure was completed. Samples of plaque were taken for microbiological culture.
Results — Sixty to ninety percent of the bacterial genera isolated from the plaque were present in the blood. Dogs classified according to severity of dental disease showed no difference in the total number of different species or number of different Gram-negative, Gram-positive, or anaerobic bacteria isolated from plaque or blood (P <.05). Bacteremia was present in all of the dogs studied, within 40 minutes from the initiation of the dental procedure, regardless of the severity of oral disease.
Conclusions — Gram-negative, Gram-positive, and anaerobic bacteria are present in blood during dental procedures; the bacteremia can persist beyond the dental procedure, and is not associated with the severity of dental disease.
Clinical Relevance — The nature and extent of bacteremia occuring during routine dental procedures is important in understanding a potential risk to dogs. 相似文献
Study Design — Bacteria cultured from the blood over time were compared with those isolated from the plaque and crevicular fluid and in relation to severity of dental disease.
Animals or Sample Population — Twenty adult greyhounds.
Methods — Blood samples were collected for culture before induction of general anesthesia, immediately after intubation, 20 minutes after initiation of the dental procedure, and at 10-minute intervals until 10 minutes after the dental procedure was completed. Samples of plaque were taken for microbiological culture.
Results — Sixty to ninety percent of the bacterial genera isolated from the plaque were present in the blood. Dogs classified according to severity of dental disease showed no difference in the total number of different species or number of different Gram-negative, Gram-positive, or anaerobic bacteria isolated from plaque or blood (P <.05). Bacteremia was present in all of the dogs studied, within 40 minutes from the initiation of the dental procedure, regardless of the severity of oral disease.
Conclusions — Gram-negative, Gram-positive, and anaerobic bacteria are present in blood during dental procedures; the bacteremia can persist beyond the dental procedure, and is not associated with the severity of dental disease.
Clinical Relevance — The nature and extent of bacteremia occuring during routine dental procedures is important in understanding a potential risk to dogs. 相似文献
52.
ROBIN M. DABAREINER DVM MS NATHANIEL A. WHITE DVM MS Diplomate ACVS KENNETH E. SULLINS DVM MS Diplomate ACVS 《Veterinary surgery : VS》1996,25(3):199-206
Medical records, radiographs, and sonograms of 63 horses with metacarpophalangeal joint synovial pad proliferation were examined retrospectively. All horses had lameness, joint effusion, or both signs associated with one or both metacarpophalangeal joints. Bony remodeling and concavity of the distodorsal aspect of the third metacarpal bone (Mc3) just proximal to the metacarpal condyles was identified by radiography in 71 joints (93%); 24 joints (32%) had radiographic evidence of a chip fracture located at the proximal dorsal aspect of the proximal phalanx. Fifty-four joints (71%) were examined by ultrasound. The mean ± SD sagittal thickness of the synovial pad was 11.3 ± 2.8 mm. Seventy-nine percent of the horses had single joint involvement with equal distribution between the right and left forelimbs. Sixty-eight joints in 55 horses were treated by arthroscopic surgery. Sixty joints (88%) had debridement of chondral or osteochondral fragmentation from the dorsal surface of Mc3 beneath the synovial pad and 30 joints (44%) had a bone chip fracture removed from the medial or lateral proximal dorsal eminence of the proximal phalanx. Complete or partial excision of both medial and lateral synovial pads was completed in 42 joints. Only the medial synovial pad was excised or trimmed in 21 joints, and 5 joints had only the lateral pad removed. Eight joints in eight horses were treated by stall rest, administration of intra-articular medication and systemic nonsteroidal anti-inflammatory drugs. Follow-up information was obtained for 50 horses treated surgically and for eight horses treated medically. Forty-three (86%) that had surgery returned to racing; 34 (68%) raced at an equivalent or better level than before surgery. Three (38%) of the medically treated horses returned to racing; only one horse raced better than the preinjury level. Horses that returned to racing at a similar or equal level of performance were significantly younger in age than horses returning at a lower level or not racing (P≤.05). Overall, horses with synovial pad proliferation treated by arthroscopic surgery had a good prognosis for return to racing at a level equal or better than before injury. 相似文献
53.
Amara H. Estrada Herbert W. Maisenbacher III VMD Robert Prošek DVM MS Jesse Schold PhD Melanie Powell BS James M. VanGilder BS 《Journal of Veterinary Cardiology》2009,11(2):79-88
Objective
To compare left ventricular synchronization and systolic performance with transvenous pacing of the right ventricular apex (RVA), left ventricular free wall (LVF) or simultaneous pacing of the RVA and LVF (BiV).Animals, materials and methods
Seven canine patients with complete heart block. Prospective study evaluating effect of pacing site. Twenty four hours following implantation of transvenous BiV pacing systems, electrocardiograms and echocardiograms were assessed during pacing from the: (1) Right Atrial Appendage/RVA (RAA/RVA), (2) RAA/LVF, and (3) RAA/BiV.Results
QRS duration was significantly shorter with BiV pacing versus LVF pacing (p < 0.001), or RVA pacing (p < 0.001). Echocardiographic indices of systolic performance fractional shortening (FS), ejection fraction (EF), cardiac output (CO) were significantly higher with BiV pacing than with pacing from the RVA (P = 0.023, 0.006, and 0.002 respectively). Cardiac output, measured by the biplane Simpson's method, was higher with LVF versus RVA pacing (P = 0.036). There was no difference in FS or EF when comparing LVF to RVA pacing. Tissue Doppler measurements of synchronization and systolic performance did not show any difference between pacing mode, but a significantly increased number of segments were seen to contract following aortic valve closure during LVF pacing (P = 0.0268) and RVA pacing (P = 0.0197) as compared to BiV pacing.Conclusions
Findings suggest that BiV pacing improves cardiac output and systolic performance versus RVA pacing. This improvement however, is not reflected in tissue Doppler indices of synchronization and systolic performance. 相似文献54.
Eileen Heldmann MS VMD Dorothy Cimino Brown DVM Diplomate ACVS Frances Shofer PhD 《Veterinary surgery : VS》1999,28(4):256-259
OBJECTIVE: To determine if the use of propofol influences the postoperative infection rate of clean surgical wounds in dogs and cats. STUDY DESIGN: Retrospective study. SAMPLE POPULATION: 863 dogs and cats undergoing clean surgical procedures. METHODS: Medical and anesthetic records of surgical cases used as part of a previously described epidemiologic study on postoperative wound infection rates were reviewed. The records of all animals with clean surgical wounds were reviewed to determine if propofol had been used for anesthetic induction or maintenance during the procedure. To determine the effect of propofol use on wound infection rate, data were analyzed using Fisher's exact test, followed by multiple logistic regression to adjust for various factors, including surgery time, time from clipping to surgery, antibiotic usage, coexisting distant infection, endocrine disease, and the use of immunosuppressive drugs in the perioperative period. RESULTS AND CONCLUSIONS: Of 863 dogs and cats with clean surgical wounds, 46 received propofol as part of the anesthetic protocol. A total of 6 of 46 animals (13%) receiving propofol developed postoperative wound infections, compared with 33 of 817 animals (4%) not receiving propofol (P = .014; % difference = 9%; 95% CI = 0.5% to 24%). Adjusting for all other factors evaluated, animals receiving propofol were 3.8 times more likely to develop postoperative wound infections compared to animals not given propofol (95% CI = 1.5-9.9). CLINICAL IMPLICATIONS: Propofol is a lipid-based emulsion capable of supporting microbial growth. Administration of a potentially contaminated solution may contribute to surgical wound infection or other patient morbidity or mortality. Strict aseptic technique in the preparation of the solution and prompt disposal of unused drug are imperative to curtail the potential for extrinsic contamination. 相似文献
55.
Jean K. Reichle DVM MS Richard A. Peterson II DVM Mary B. Mahaffey DVM MS Curtis G. Schelling VMD MS Paul Y. Barthez DVM PHD 《Veterinary radiology & ultrasound》2003,44(4):433-437
Four dogs with ureteral fibroepithelial polyps, ranging from 9-12 years of age, are presented in this report. The patients presented with urinary incontinence, urinary tract infection, and/or polydypsia and pollakiuria. All dogs were intact at the time of diagnosis or for the majority of their lives and three were male. Various diagnostic procedures were performed including ultrasonography, contrast radiography, and nuclear scintigraphy. Not all procedures were performed in all patients. Findings included ureteral dilation proximal to the level of an intraluminal mass and ipsilateral hydronephrosis. Unilateral ureteronephrectomy was performed in three dogs with masses in the proximal ureter; ureteral resection and anastamosis was performed in the remaining patient with a mass located in the distal ureter. The same pathologist (RAP) reviewed all four lesions. The lesions appeared polypoid and were attached to the ureteral wall by a thin stalk. Histopathologically, they contained a superficial layer of well-differentiated transitional epithelial cells overlying a prominent fibrovascular stroma with a mild (three dogs) or marked (one dog) degree of lymphoplasmacytic inflammation. This disease may represent a benign neoplasm or a chronic inflammatory reaction and has a good prognosis with surgical removal. Its histopathological characteristics, higher incidence in males, and location more commonly within the upper third of the ureter is remarkably similar to the disease in humans. 相似文献
56.
57.
Michael D. Lucroy DVM MS Jeffrey N. Peck DVM Clifford R. Berry DVM 《Veterinary radiology & ultrasound》2001,42(3):218-220
A 6-year-old neutered male Rottweiler was examined for a progressive right pelvic limb lameness. In radiographs of the right stifle, there was an osteolytic lesion with irregular new bone formation along the cranial aspect of the patella consistent with an aggressive bone lesion. In thoracic radiographs, there were multiple soft tissue nodular opacities throughout the lung fields, consistent with pulmonary metastases. Microscopically, fine needle aspirate samples from the right patella contained pleomorphic spindle cells with cytologic features of osteosarcoma. The presence of pulmonary metastases at the time of initial diagnosis in the dog described herein suggests that osteosarcoma of the patella has the potential for similar aggressive biologic behavior as that seen in dogs with appendicular osteosarcoma. 相似文献
58.
Franois Serres DVM Valrie Chetboul DVM PhD Renaud Tissier DVM PhD Vassiliki Gouni DVM Aude Desmyter DVM Carolina Carlos Sampedrano DVM MS Jean-Louis Pouchelon DVM 《Journal of Veterinary Cardiology》2009,11(1):23-29
Objective
To determine if the pulmonary to systemic flow ratio (Qp/Qs) could be assessed in healthy awake dogs using Doppler echocardiography.Background
Qp/Qs could provide reliable information in assessing the severity of intracardiac shunts (ICS) by quantifying pulmonary overcirculation. Qp/Qs has been validated against electromagnetic flowmeter methods in experimental canine models. However, its clinical applicability in awake dogs has never been assessed.Animals, materials and methods
Six healthy dogs were used to determine the repeatability and reproducibility of the technique (Study 1); Qp/Qs was then prospectively assessed in 50 healthy dogs (Study 2). In both studies Qp/Qs was calculated in awake animals using a standardized Doppler echocardiographic method.Results
Within- and between-day coefficients of variation for Qp/Qs were <10% (Study 1). For Study 2, a relatively wide range of Qp/Qs was found (reference range = 0.71-1.29; mean ± SD = 1.00 ± 0.15).Conclusions
Qp/Qs can be assessed with good repeatability and reproducibility in healthy dogs. However, the wide range of Qp/Qs obtained in the healthy population may suggest a limited usefulness of this variable for accurately assessing ICS severity in diseased animals. This needs to be assessed in further prospective and longitudinal studies including a large number of animals with ICS of various grades. 相似文献59.
60.
JONATHAN L. STOWATER DVM MS CARL A. KIRKER-HEAD MA VET MB MRCVS RICHARD M. JAKOWSKI DVM PHD 《Veterinary radiology & ultrasound》1986,27(4):115-117
Osteochondrosis of the lateral femoral condyles was diagnosed radiographically in an 8-month-old, female Arabian horse, which had been presented with a hindlimb lameness. The diagnosis was confirmed by gross and microscopic pathology. The location of the lesions was considered unusual for osteochondrosis in the horse. 相似文献