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张旭 《农业考古》2020,(1):7-15
本文对内蒙古中南部先秦两汉时期11组古代人群的龋病状况做了统计与分析,在与我国北方地区16组古代人骨材料对比的基础上,进一步讨论了其生业模式与龋患的关系。龋病的罹患情况是反映人群摄入碳水化合物含量的有效指标,龋病与人类社会生产力发展以及农业出现相关,内蒙古中南部地区先秦两汉时期不同生业模式人群的碳水化合物食物摄取量的多寡决定了其龋齿发病率的高低,以农业经济为主的人群龋齿发病率最高,并随着时代发展而进一步增加;以畜牧或渔猎采集经济为生的古代人群龋病发病率较低;农牧兼营的混合经济人群龋齿发病率居中,并且因农业经济所占比重的不同,其变异范围较大。  相似文献   
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本文旨在研究不同生物素水平对生长前期北京鸭生长性能的影响,并对生物素缺乏症———脚裂症进行初步探究。试验选用体重相近的1日龄雄性北京鸭480只,随机分成10组,每组6个重复,每个重复8只鸭。各组分别添加0、0.03、0.06、0.09、0.12、0.15、0.18、0.21、1.50 mg/kg生物素及3 g/kg蛋清粉。试验期4周。结果表明,不同生物素水平对1~21日龄北京鸭平均日采食量和平均日增重有显著影响(P<0.05),但对料重比没有显著影响(P>0.05)。统计发现,各组表现出不同程度的脚裂症,其中3 g/kg蛋清粉组最为严重;生物素添加水平高于0.15 mg/kg时,脚裂症得到有效缓解。不同生物素水平对28日龄北京鸭肝脏磷脂含量和血清谷丙转氨酶(ALT)和天冬氨酸氨基转移酶(AST)活性有显著影响(P<0.05)。通过数据分析得出,以平均日增重为衡量指标,采用直线折线和二次曲线模型估测生物素适宜需要量分别为0.180和0.202 mg/kg,并初步判断脚裂症与脱水存在一定的关系。  相似文献   
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Feline chronic gingivitis/stomatitis (FCGS) is a painful inflammatory disease in cats. Extraction of teeth, including all premolars and molars, has been shown to be the therapy of choice in cats not responding sufficiently to home care (e.g. tooth brushing) and/or medical treatment (corticosteroids and/or antibiotics). In this study, we hypothesize that a cat food with an omega‐6 polyunsaturated fatty acid (ω6 PUFA) to ω3 PUFA ratio of 10:1 reduces inflammation of the FCGS and accelerates soft tissue wound healing of the gingiva after dental extractions, compared to a cat food with a ω6:ω3 PUFA ratio of 40:1. The cats were fed diets with chicken fat and fish oil as sources of fatty acids. In one diet, part of the fish oil was replaced by safflower oil, resulting in two diets with ω6:ω3 PUFA ratios of 10:1 and 40:1. This double‐blinded study in two groups of seven cats revealed that dietary fatty acids influence the composition of plasma cholesteryl esters and plasma levels of inflammatory cytokines. The diet with the 10:1 ratio lowered PGD2, PGE2 and LTB4 plasma levels significantly, compared to the diet with the 40:1 ratio (p = 0.05, p = 0.04, and p = 0.02 respectively). However, feeding diets with dietary ω6:ω3 PUFA ratios of 10:1 and 40:1, given to cats with FCGS for 4 weeks after extraction of all premolars and molars, did not alter the degree of inflammation or wound healing.  相似文献   
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为完善湿垫风机系统在农业建筑夏季蒸发冷却中的应用,研究了湿垫冷却装置在喷淋水完全蒸发条件下的热质交换特征,经理论推导给出了确定喷淋水量及湿垫合理参数的计算式。  相似文献   
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通过文献资料法、录像统计法、观察分析法,以部分世界女子沙滩排球巡回赛、全国女子沙滩排球巡回赛为研究对象,对沙滩排球垫球调整技术在比赛中的运用进行研究分析。认为沙滩排球比赛受自然环境的影响和规则的限制,传球调整容易造成持球和连击,而我国沙滩排球队伍仍然更多采用传球调整技术。重视垫球调整是提高我国沙滩排球技战术水平与世界接轨的发展趋势,也是适应自然条件和适应规则的有效措施。  相似文献   
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The objective of this study was to determine the response of broilers to the combination of multi-enzymes and direct-fed microbial (DFM) under commercial production settings. A total of 7,000 1-day-old male broilers (Ross 308) were distributed over 10 pens (700 broilers/pen). Two dietary treatments were tested using complete randomized design, including a control diet and a test diet with addition of multi-enzymes (xylanase, amylase, and protease (XAP)] and DFM (a combination of spores from 3 strains ofBacillus amyloliquefaciens). Pelleted diets were offered ad libitum in 3 phases and water was freely available. During starter and grower phases (0 to 21 d), the enzyme and DFM combination resulted in improved FE (P < 0.05). During the finisher phase, higher feed intake and BW gain (P < 0.05) were observed for the test group. Overall, there were significantly higher feed intake, BW gain, and lower water-to-feed ratio in test group compared to the control group. This was related to improved (P < 0.05) modified production efficiency factor which was calculated based on final BW, survival rate, feeding period, and mortality-weight-corrected FCR. The test group had improved litter quality and a reduced foot-pad lesion score compared to the control. In addition, there was a tendency (P < 0.1) of reducingClostridium perfringens population in cecal digesta and higher lactic acid content in the ileal digesta, when expressed on an as-is basis, in the test group. In this study, we demonstrated that using a multi-enzymes and DFM combination in the diet for broilers can result in improved FE in starter/grower phases and animal welfare parameters, and lead to improved production efficiency under commercial settings.  相似文献   
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This retrospective study describes the computed tomography (CT) findings in 59 horses presented with diseases of the head over 8 years that underwent CT examination of this region, including dental or sinonasal diseases (Group A) (n = 42), osseous and/or articular diseases (Group B) (n = 11) and soft tissue diseases (Group C) (n = 6). For Group A, radiographic and CT findings comparison was possible. Computed tomography had higher sensitivity (100%) and specificity (96.7%) than radiography in diagnosing dental disease. Compared to CT, radiographic identification of sinus involvement was less sensitive, particularly for ventral conchal and sphenopalatine sinuses and presented an overall sensitivity of 43.5 and 16.7%, respectively. In Group B CT allowed identification of a higher number of bone fragments and fractures in the maxillary, lacrimal, sphenoidal, temporal and zygomatic bones not identified radiographically. Accurate identification of CT changes in the temporomandibular joint and temporohyoid articulation was also possible. Group C included both intra‐ and extra‐cranial disease, retrobulbar masses being the most representative pathology (n = 3). In this group, CT was considered the gold standard for detection of periorbital diseases. We conclude that CT is an imaging technique with high diagnostic value for evaluating the equine head, yielding additional information over multiple radiographic views, which may alter the outcome of the case. Additionally, this paper reports several conditions not previously described using CT.  相似文献   
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A pulpar abscess of cheek tooth 307 (according to the Triadan numerical system) was diagnosed in a 7‐year‐old female Quarter Horse. History included a painful response to palpation in the mandibular region for approximately 4 weeks. Symptoms included swelling of the mandibular bone with subsequent fistulisation. A complete intraoral examination was performed and no lesions or abnormalities were found. Digital radiographs of the mandibular arcade demonstrated a periapical lesion of cheek tooth 307. Various therapeutic options were considered, including standing oral extraction, retrograde repulsion and endodontic therapy. Together with the client, a decision was made to perform endodontic therapy, with the double aim of preserving the tooth and maintaining normal molar occlusion. This was done under general anaesthesia without apicectomy, and using materials commonly used in the field of human endodontics. Following surgery, radiographs were taken and confirmed the complete sealing of the pulp canals. Recovery was uneventful and no post operative complications were observed. A complete intraoral follow‐up examination was performed one year after surgery, and revealed normal eruption and occlusion of the tooth involved. Radiographic examination confirmed the correct position and integrity of the sealant material, as well as normal perialveolar bone structure. This case report indicates that endodontic therapy, following the above protocol, involving pulpectomy and sealing of the pulp cavity, represents a valid alternative to the more commonly used technique of tooth extraction.  相似文献   
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