内蒙古中南部先秦两汉时期人群龋病与生业模式初探

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。     

不同生育期水稻根表铁膜的形成及其对水稻吸收和转运Cd的影响

采用盆栽试验,研究不同生育期水稻根表铁膜的形成及其对水稻吸收和转运Cd的影响.结果表明,水稻根表铁膜的形成受到不同品种和不同生育期影响.随着生育期的延长,两种水稻(YD6和NK57)根表铁膜形成量均呈下降趋势.与分蘖期相比,YD6和NK57根表铁膜量孕穗期分别减少82.9％和44.4％,成熟期分别减少85.2％和82.52％.两种水稻根系和茎叶Cd含量随着水稻生育期的延长而增加.YD6籽粒Cd含量显著高于NK57.Cd在水稻植株的富集系数和分配比率随着不同品种和生育期产生较大变化.YD6品种从根表铁膜和根系向籽粒转运Cd的能力显著大于NK57.水稻成熟期,根表铁膜量与茎叶和籽粒Cd含量呈极显著的负相关(P＜0.01),说明根表铁膜形成可抑制Cd向水稻地上部转运.研究结果暗示可通过不同生育期的管理调节水稻根表铁膜的形成,减少Cd向稻谷中转运,从而降低Cd对人体健康的危害.     

北京市朝阳区景观连接度距离阈值研究

景观连接度方法是一种进行景观生态安全格局定量化评价的较好方法。此方法的应用中,景观连接度适宜距离阈值是一个关键因素,以北京市朝阳区为例对其展开研究。选取景观组分数(NC)、整体连接度指数(ⅡC)以及可能连接度指数(PC)来表征景观连接度以及计算斑块重要性值(dI);预设9个距离阈值,探讨不同距离阈值下景观连接度和斑块重要性值的变化规律。结果表明:北京市朝阳区景观连接度的距离阈值以400～600 m为宜。在此距离阈值的约束下分析表明,小型生态斑块对提高区域景观连接度有重要作用。     

Suppression of influenza virus infection by the orf virus isolated in Taiwan

Orf virus (ORFV), a member of parapoxvirus, is an enveloped virus with genome of double-stranded DNA. ORFV causes contagious pustular dermatitis or contagious ecthyma in sheep and goats worldwide. In general, detection of viral DNA and observing ORFV virion in tissues of afflicted animals are two methods commonly used for diagnosis of orf infection; however, isolation of the ORFV in cell culture using virus-containing tissue as inoculum is known to be difficult. In this work, the ORFV (Hoping strain) isolated in central Taiwan was successfully grown in cell culture. We further examined the biochemical characteristic of our isolate, including viral genotyping, viral mRNA and protein expression. By electron microscopy, one unique form of viral particle from ORFV infected cellular lysate was demonstrated in the negative-stained field. Moreover, immunomodulating and anti-influenza virus properties of this ORFV were investigated. ORFV stimulated human monocytes (THP-1) secreting proinflammatory cytokines IL-8 and TNF-α. And, pre-treatment of ORFV-infected cell medium prevents A549 cells from subsequent type A influenza virus (IAV) infection. Similarly, mice infected with ORFV via both intramuscular and subcutaneous routes at two days prior to IAV infection significantly decreased the replication of IAV. In summary, the results of a current study indicated our Hoping strain harbors the immune modulator property; with such a bio-adjuvanticity, we further proved that pre-exposure of ORFV protects animals from subsequent IAV infection.     

基于神经网络的猪肉新鲜度检测分级系统

首先,应用CCD光电检测技术对可表征猪肉新鲜度的多个特征量进行检测;然后,利用数字图像处理技术对检测到的特征量进行处理;最后,利用神经网络技术研究非相干微量参数的多数据融合检测方法,从而实现对猪肉新鲜度检测分级辨识。     

Potential for the alleviation of arsenic toxicity in paddy rice using amorphous iron-(hydr)oxide amendments

Abstract

A pot culture experiment was conducted to investigate the effects of amorphous iron-(hydr)oxide (Am-FeOH) amendments on arsenic (As) availability and its uptake by rice (Oryza sativa L. cv. BR28) irrigated with As-contaminated water. A rhizobag system was established using 3.5 L plastic pots, each containing one central compartment for plant growth, a middle compartment and an outside compartment. Three levels of laboratory-synthesized Am-FeOH (0, 0.1 and 0.5% w/w) were used to amend samples of the As-free sandy loam paddy soil placed into each compartment of the rhizobag system. The soils were submerged with a solution containing 5 mg L^?1 As(V). Two-week-old rice seedlings were planted in the central compartments and cultured for 9 weeks under greenhouse conditions. The addition of 0.1% Am-FeOH to the soil irrigated with As-contaminated water improved plant growth, reduced the As concentration in the plants and enhanced Fe-plaque formation on the root surfaces. Analysis of soil solution samples collected during the experiment revealed higher pH levels and lower redox potentials in the soils amended with Am-FeOH at the onset of soil submergence, but later the soil solution collected from the 0.1% Am-FeOH treatment was slightly acidic and more oxidized than the solution from the 0% treatment. This indicated active functioning of the roots in the soil treated with 0.1% Am-FeOH. The concentrations of As(III) in the soil solution collected from the central compartment were significantly reduced by the Am-FeOH amendments, whereas in the soil treated with 0% Fe, As(III) accumulated in the rhizosphere, particularly during the late-cultivation period. The improvement in plant growth and reduction in As uptake by plants growing in the Am-FeOH treated soil could be attributed to the reduction of available As in the soil solution, mainly as a result of the binding of As to the Fe-plaque on the root surfaces.     

Endodontic treatment of a mandibular premolar abscess in a horse: A case study

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.     

干湿交替对作物根际特征及铁膜形成的影响研究进展

铁膜普遍存在于水生植物的根系表面,根际周围Fe~(2+)的浓度和根系氧化力决定了根表铁膜的数量。干湿交替是农业生产中常用的灌溉技术。在干湿交替过程中,水分和氧气含量的变化导致根际土壤发生一系列物理、化学和生物学变化,从而对根表铁膜的形成产生影响。本文综述了干湿交替过程对根际特征变化的影响,分析了根表铁膜的形成条件、化学组成与空间结构和根表铁膜的形成过程,并在此基础上探讨了干湿交替对铁膜形成的影响以及干湿交替诱导铁膜形成的可能机制。最后对干湿交替诱导铁膜形成的研究方法与应用前景进行了展望。