全文获取类型
收费全文 | 558篇 |
免费 | 26篇 |
国内免费 | 1篇 |
专业分类
林业 | 16篇 |
农学 | 27篇 |
基础科学 | 1篇 |
73篇 | |
综合类 | 40篇 |
农作物 | 62篇 |
水产渔业 | 38篇 |
畜牧兽医 | 304篇 |
园艺 | 6篇 |
植物保护 | 18篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 3篇 |
2021年 | 10篇 |
2020年 | 13篇 |
2019年 | 10篇 |
2018年 | 13篇 |
2017年 | 15篇 |
2016年 | 10篇 |
2015年 | 25篇 |
2014年 | 26篇 |
2013年 | 38篇 |
2012年 | 35篇 |
2011年 | 67篇 |
2010年 | 33篇 |
2009年 | 22篇 |
2008年 | 47篇 |
2007年 | 25篇 |
2006年 | 35篇 |
2005年 | 26篇 |
2004年 | 20篇 |
2003年 | 28篇 |
2002年 | 23篇 |
2001年 | 16篇 |
2000年 | 15篇 |
1999年 | 7篇 |
1996年 | 1篇 |
1994年 | 2篇 |
1993年 | 5篇 |
1992年 | 3篇 |
1990年 | 1篇 |
1989年 | 3篇 |
1983年 | 2篇 |
1977年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有585条查询结果,搜索用时 484 毫秒
561.
Computed tomographic and radiographic bronchial collapse may be a normal characteristic of forced expiration in dogs 下载免费PDF全文
Hyunryung Kim Young Joo Kim Hanbin Lee Taegeon An Jin Yu Hyounglok Yoon Gayeon An Jaihyun Jung Jinhwa Chang Dongwoo Chang 《Veterinary radiology & ultrasound》2018,59(5):551-563
Tracheobronchomalacia has been diagnosed using radiography or bronchoscopy to confirm bronchial changes in luminal diameter during the respiratory cycle. However, studies in healthy humans suggest that some degree of bronchial collapse may be observed during the normal respiratory cycle. In this analytical study, the luminal diameter of the bronchus to each of the six pulmonary lobes and the mean percentage of expiratory collapse from end inspiratory, end expiratory, and two forced expiratory phases (10 and 15 ml/kg) were determined via computed tomography (CT) and radiography in 22 healthy Beagle dogs. The bronchial collapsibility was significantly greater during the forced expiration than the end expiration (P < 0.001); the same results were observed in dorsal and sagittal CT images and radiographs (P < 0.001). Median collapsibility values associated with 15 ml/kg forced expiratory collapse determined via cross‐sectional CT images were measured as 16.6–45.5% and differed according to the pulmonary lobe. Median collapsibilities on radiography with 15 ml/kg forced expiration were 57.8% and 62.1% in the right cranial lobe and right caudal lobe, respectively. In conclusion, bronchial diameter may change during the respiratory cycle, and some degree of reduction in bronchial diameter may be an incidental finding in healthy dogs. More rigorous criteria are needed with regards to bronchial collapsibility during normal respiration for the diagnosis of bronchomalacia in order to avoid false‐positive diagnoses. 相似文献
562.
IMAGING DIAGNOSIS — RADIOGRAPHY,ULTRASONOGRAPHY, AND COMPUTED TOMOGRAPHY OF A GIANT FECALOMA CAUSING STERCORAL PERFORATION OF THE COLON IN A DOG WITH A PROSTATIC ABSCESS 下载免费PDF全文
A mixed‐breed dog presented with tenesmus, hematochezia, and abdominal distension of 2 weeks duration. Radiography showed a large round mass with a “soap‐bubble” appearance and shell‐like mineralization in the caudal abdomen. Computed tomography revealed a lamellate mineralized mass 8 cm in diameter and containing air in the descending colon and prostatic abscess. Heterogeneously contrast‐enhanced, irregularly thickened colonic wall with intramural and peritoneal free gas indicated stercoral colonic perforation. Surgical intervention revealed a tumor‐like giant fecaloma in the descending colon adjoining the prostate with extensive wall rupture and fecal peritonitis. Hypothetically, prostatic inflammation may affect colonic motility with resultant fecaloma formation. 相似文献
563.
Park MS Lee HY Li SP Koh PO Bahk JY Chung BC Kim MO 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2007,69(1):25-30
Neural transplantation is one of the most promising treatments for neurodegenerative disorders. Survival rates of embryonic dopamine (DA) neurons following transplantation are low, between 2% and 20% in a number of animal models. To further establish survival changes of the transplanted gestational day 13.5 ventral mesencephalic (VM) cells into left intact adult rat striata so that design strategies of increasing survival of DA neurons, the tyrosine hydroxylase (TH) expression of VM-derived progenitor cells has been examined using immunohistochemistry and Western blot analysis. TH immunostaining revealed that the grafted VM cells developed to mature TH-positive neurons strongly at 3 weeks, peaked at 4 weeks, thereafter, gradually dropped following the degenerative expression of the grafted cells at both 5 and 6 weeks after transplantation. Western blot analysis also showed that the TH proteins were maximally expressed at 4 weeks post-grafting. Our finding suggested that the peak of surviving VM-derived TH positive cells occurred approximately 4 weeks after transplantation. 相似文献
564.
Primary cranial mediastinal hemangiosarcomas are uncommon tumors. A 30-kg, 2-year-old, intact female German shepherd was presented for evaluation of cachexia and respiratory distress of a few days’ duration. Lateral radiographic projection of the thorax revealed significant pleural effusion. Computed tomography revealed a cranial mediastinal mass effect adjacent to the heart. On surgical exploration, a pedunculated mass attached to the esophagus, trachea, brachiocephalic trunk, left subclavian artery and cranial vena cava without attachment to the right atrium and auricular appendage was removed and debrided by use of blunt dissection and dry gauzes, respectively. Histopathology results described the cranial mediastinal mass as hemangiosarcoma. At 8 months and 5 days post-operatively, the patient died. Primary cranial mediastinal hemangiosarcomas, although a seemingly rare cause of thoracic pathology in young dogs, should be considered in the differential diagnosis for pleural effusion and soft tissue mass effect in the cranial mediastinum. This is the first case report in a dog to describe primary cranial mediastinal hemangiosarcoma. 相似文献
565.
Won‐gyun Son Min Jang Junghee Yoon Lyon Y Lee Inhyung Lee 《Veterinary anaesthesia and analgesia》2014,41(5):526-533
ObjectiveTo determine the effect of injection speed on epidural pressure (EP), injection pressure (IP), epidural distribution (ED) of solution, and extent of sensory blockade (SB) during lumbosacral epidural anesthesia in dogs.Study designProspective experimental trial.AnimalsTen healthy adult Beagle dogs weighing 8.7 ± 1.6 kg.MethodsGeneral anesthesia was induced with propofol administered intravenously and maintained with isoflurane. Keeping the dogs in sternal recumbency, two spinal needles connected to electrical pressure transducers were inserted into the L6-L7 and the L7-S1 intervertebral epidural spaces for EP and IP measurements, respectively. Bupivacaine 0.5% diluted in iohexol was administered epidurally to each dog via spinal needle at L7-S1 intervertebral space, at two rates of injection (1 and 2 mL minute?1 groups), with a 1-week washout period. Epidural distribution was verified with computed tomography, and SB was evaluated after arousal by pinching the skin with a mosquito hemostatic forceps over the vertebral dermatomes. The results were analyzed according to each injection speed, using paired t- and Wilcoxon signed-rank tests.ResultsMean ± SD of baseline EP and IP values were 2.1 ± 6.1 and 2.6 ± 7.1 mmHg, respectively. Significant differences were observed between 1 and 2 mL minute?1 groups for peak EP (23.1 ± 8.5 and 35.0 ± 14.5 mmHg, p = 0.047) and peak IP (68.5 ± 10.7 and 144.7 ± 32.6 mmHg, p <0.001). However, the median (range) of the ED, 11.5 (4–22) and 12 (5–21) vertebrae, and SB, 3.5 (0–20) and 1 (0–20) dermatomes, values of the two groups were not related to injection speed.Conclusions and clinical relevanceThe EP profile during injection was measured by separating the injection and pressure monitoring lines. The increase in epidural injection speed increased the EP, but not the ED or the SB in dogs. 相似文献
566.
Wan?Soo?KimEmail author Seong-Jin?Yoon Jong?Man?Kim Joon?Woo?Gil Tae?Won?Lee 《Fisheries Science》2005,71(3):471-478
ABSTRACT: The effects of temperature changes on the endogenous rhythm of oxygen consumption in the Japanese flounder Paralichthys olivaceus which were acclimated to 3, 14 or 20°C in advance were investigated. The oxygen consumption rate (OCR) of individuals (total length >28 cm) that were acclimated to 3°C, maintained a relatively low value of 6.9 ± 2.3 mL (mean ± SD) O2 /kg ww (wet weight)/h till 5.8°C, which is considered a 'minimum' rate. Thereafter, the OCR gradually increased up to 18.7 mL O2 /kg ww/h at the temperature of 10.6°C. The OCR of individuals acclimated to 14°C stabilized with 124.2 ± 24.1 mL O2 /kg ww/h, when tested at the relatively constant temperature of 14.4 ± 0.17°C. Maximum entropy spectral analysis revealed that the peak OCR occurred at 23.9 h intervals, which could be a circadian rhythm. The mean OCR showed a peak at 06.00–08.00 hours. For the temperature above 25°C in which the fish were acclimated to 20°C, the rhythmic patterns of OCR were observed until the experimental temperature reached 26.4°C. For the temperature above 28.4°C, the metabolic activity rhythm of the OCR was dampened and then the OCR abruptly rose again. It is assumed that the oscillator of the endogenous rhythm lost the governing of normal metabolic activity in Japanese flounders above 28.4°C. These results suggest that the temperatures of around 5.8, 26.4 and 28.4°C are the 'lower limit temperature', 'upper incipient lethal temperature', and the 'critical thermal maximum', respectively, for the endogenous rhythm of oxygen consumption in the Japanese flounder. 相似文献
567.
568.
Hwang WS Roh SI Lee BC Kang SK Kwon DK Kim S Kim SJ Park SW Kwon HS Lee CK Lee JB Kim JM Ahn C Paek SH Chang SS Koo JJ Yoon HS Hwang JH Hwang YY Park YS Oh SK Kim HS Park JH Moon SY Schatten G 《Science (New York, N.Y.)》2005,308(5729):1777-1783
Patient-specific, immune-matched human embryonic stem cells (hESCs) are anticipated to be of great biomedical importance for studies of disease and development and to advance clinical deliberations regarding stem cell transplantation. Eleven hESC lines were established by somatic cell nuclear transfer (SCNT) of skin cells from patients with disease or injury into donated oocytes. These lines, nuclear transfer (NT)-hESCs, grown on human feeders from the same NT donor or from genetically unrelated individuals, were established at high rates, regardless of NT donor sex or age. NT-hESCs were pluripotent, chromosomally normal, and matched the NT patient's DNA. The major histocompatibility complex identity of each NT-hESC when compared to the patient's own showed immunological compatibility, which is important for eventual transplantation. With the generation of these NT-hESCs, evaluations of genetic and epigenetic stability can be made. Additional work remains to be done regarding the development of reliable directed differentiation and the elimination of remaining animal components. Before clinical use of these cells can occur, preclinical evidence is required to prove that transplantation of differentiated NT-hESCs can be safe, effective, and tolerated. 相似文献
569.
570.
Aroma-active components in fermented bamboo shoots. 总被引:4,自引:0,他引:4
Shih-Guei Fu Youngmo Yoon Russell Bazemore 《Journal of agricultural and food chemistry》2002,50(3):549-554
Bamboo shoots (Phyllostachys pubescens) were fermented and prepared in a traditional Taiwanese manner. Static and dynamic headspace extractions of volatile compounds were conducted by solid phase microextraction (SPME) and by cryogenic focusing purge and trap, respectively. Volatile analysis was conducted with gas chromatography and mass spectrometry. Gas chromatography-olfactometry (GCO) was conducted utilizing the Osme time-intensity method. Of 70 volatile compounds detected, 29 possessed aroma activity, and the most odor active included p-cresol (barn-like), 2-heptanol (mushroom), acetic acid (vinegar), and 1-octen-3-ol (mushroom). SPME extracted 66 compounds, purge and trap extracted 14 compounds, and 12 compounds were common to both methods. The Osme GCO technique coupled with SPME is an effective tool for the extraction and evaluation of aroma-active headspace volatiles. 相似文献