检索结果-南通市图书馆

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

多形核中性粒细胞的获得性异常

国外医学（输血及血液学分册） 1991年第3期14卷 162-164页

作者： fletcher J 金任天

现今对中性多形核粒细胞(PMN)功能的了解多来自对健康人的体外实验,体内的情况常限于推论,疾病时PMN功能的改变可能仍属于生理性范畴,但本文作为“异常”而加以描述。在体外,PMN可被受调理素作用的颗粒或可溶性物质,如来自细胞壁的FMLP... 详细信息

现今对中性多形核粒细胞(PMN)功能的了解多来自对健康人的体外实验,体内的情况常限于推论,疾病时PMN功能的改变可能仍属于生理性范畴,但本文作为“异常”而加以描述。在体外,PMN可被受调理素作用的颗粒或可溶性物质,如来自细胞壁的FMLP(甲酰-甲硫氨酰-亮氨酰-苯丙氨酸)和C5 des arg(去精氨酸C5)

关键词： PMN 多形核粒细胞获得性异常

利用微阵列研究铁过量诱导的家蚕（Bombyx mori）转录组

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

利用微阵列研究铁过量诱导的家蚕（Bombyx mori）转录组

作者： Emmanuella Esi fletcher 江苏大学

学位级别：硕士

铁是一种重要的营养元素,对许多重要的生物过程都是必不可少的。但是,过量的铁也会导致生物毒性。铁通过参与Fenton化学,产生活性氧,导致DNA链断裂、脂质过氧化和蛋白质变性。本研究的目的是通过微阵列分析,研究长期铁饮食对家蚕的生物... 详细信息

铁是一种重要的营养元素,对许多重要的生物过程都是必不可少的。但是,过量的铁也会导致生物毒性。铁通过参与Fenton化学,产生活性氧,导致DNA链断裂、脂质过氧化和蛋白质变性。本研究的目的是通过微阵列分析,研究长期铁饮食对家蚕的生物学过程的影响,确定铁(10和100ppm)饮食对家蚕体内不同基因表达的影响。通过将铁饮食和正常饮食家蚕整个转录组基因表达的变化联系起来,鉴定出上调和下调基因。本研究的目的不仅是鉴定这些新基因,还要观察家蚕生长补铁期间的外部生物学变化。以新鲜桑树为原料,采用氯化铁水溶液喷雾法制备含铁日粮喂养新孵出的蚕。第五龄第四天时,家蚕称重。结果表明,1、10和100ppm铁组在第5龄第4天的体重分别比对照组高14.7%(P<0.01)、20.0(P<0.01)和18.14%(P<0.01)。同时,1000ppm组不仅生长缓慢,而且由于铁超载引起的高毒性代谢而死亡。采用电感耦合等离子体原子发射光谱法(ICP-AES)检测1,10,100ppm铁组血淋巴铁含量与对照组比较,分别为119.7%,165.3%(P<0.05),213.5%(P<0.01)。用抗铁蛋白H亚基抗体对血淋巴蛋白进行免疫印迹分析,结果表明1,10,100ppm组有明显的特异带,对照组无明显带,说明家蚕铁超载模型是有效的、可行的。通过进一步的转录组分析,以便更好地了解昆虫基因水平上铁的生物学途径和分子机制。采用微阵列分析与对照组相比,分别在10和100 ppm铁组观察到523和326个差异表达基因。在这些基因中,有249个在10-100个铁组之间很常见,其中152个和97个基因分别上调和下调。GO分析表明,79个上调基因,49个下调基因中至少有一个匹配。上调基因52个,下调基因8个,分别参与了78和14个KEGG通路。涉及的常见基因有12个丝氨酸蛋白酶和丝氨酸蛋白酶同系物,19个已知铁调节基因,24个免疫相关基因,41个表皮和表皮基因。在整个转录组学分析后,发现与多种基因(羧肽酶A、纤维六聚糖酶/p25、丝氨酸蛋白酶同系物85、真菌蛋白酶抑制剂F、转铁蛋白、性特异性存储蛋白2、表皮蛋白CPH45、昆虫肠粘蛋白、肽聚糖识别蛋白B和未知基因)有关。在调节铁的过载反应时,有助于避免离子分布的不平衡。在对照组第5龄的第4天,10,100ppm组,通过设计特异性RT-qPCR引物,验证了10个基因的基因表达水平。结果表明,10个基因表达水平的变化趋势与微阵列测量的变化趋势相似。

关键词：家蚕铁超载 DNA微阵列全转录组分析基因表达

Testing an Open-Source Multi Brand Sensor Node to Monitor Variability of Environmental Conditions inside a Greenhouse

同方学位论文库评论

在线全文

同方学位论文库

学校读者我要写书评

暂无评论

Agricultural Sciences 2021年第3期12卷 159-180页

作者： Reginald S. fletcher Daniel K. Fisher United States Department of Agriculture Agricultural Research Service Crop Production Systems Research Unit Stoneville USA Sustainable Water Management Research Unit Stoneville USA

A research project was undertaken to collect data to study the variability in environmental parameters inside a greenhouse. The specific objectives of the project were to 1) develop the network of open-source sensor nodes, 2) evaluate the performance of the individual sensors, and 3) quantify the spatial variability of environmental parameters within the greenhouse. The sensor system consisted of a sensor node equipped with three temperature and relative humidity sensors, one light-level sensor, one barometric pressure sensor, AA batteries, and a microcontroller board with a built-in radio to transfer the data wirelessly. The sensors were controlled with open-source technology. Twelve sensor nodes were fabricated and placed at different locations in a greenhouse to evaluate variability in sensor location and environmental parameters. Data collected during February 2019 were used to test the sensors. Heatmaps were employed to assess the variability of the measurements. Variability in greenhouse temperature, relative humidity, and light level conditions was identified with the sensor system. Overall, environmental measures based on time of day appeared to be a better grouping mechanism for analysis than sensor location in the greenhouse. Similar patterns were observed between the different sensor manufacturer’s heatmaps for the temperature sensors and relative humidity sensors. This study provided a protocol for developing the inexpensive multi-sensor sensor node and showed that automated measurements obtained with the system could help monitor variation in a greenhouse setting. The costs of the system components fabricated for this study included US$76 for each sensor node and US$55 for the gateway, totaling US$967 for the 12-node study described.

关键词： Arduino Microcontroller LoRa Radio Temperature Humidity Light Level Clustering Heatmaps

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

塔塔需备总资本豢养“虎豹”

汽车与配件 2008年第15期 32-33页

作者： Ian fletcher Rebecca Wright

经济状况和未来的排放要求可能对这两个品牌不利,塔塔应为此做好准备,并具有足够的资本,才能安全渡过这场经济风暴。

关键词：资本塔豢养经济状况排放要求豹虎

Implementation of a nurse-led protocol for early extubation after cardiac surgery: A pilot study

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

World Journal of Critical Care Medicine 2019年第3期8卷 28-35页

作者： Giovanni Serena Carlos Corredor Nick fletcher Filippo Sanfilippo Cardiothoracic Intensive Care Unit Intensive Care Directorate-St Georges Healthcare NHS Foundation Trust

BACKGROUND Protocols for nurse-led extubation are as safe as a physician-guided weaning in general intensive care unit(ICU).Early extubation is a cornerstone of fast-track cardiac surgery,and it has been mainly implemented in post-anaesthesia care *** a nurse-led extubation protocol may lead to reduced extubation *** To investigate results of the implementation of a nurse-led protocol for early extubation after elective cardiac surgery,aiming at higher extubation rates by the third postoperative *** A single centre prospective study in an 18-bed,consultant-led Cardiothoracic ICU,with a 1:1 nurse-to-patient *** a 3-wk period,the protocol was implemented with:(1)Structured teaching sessions at nurse handover and at bed-space(all staff received teaching,over 90%were exposed at least twice;(2)Email;and(3)Laminated sheets at *** compared“standard practice”and“intervention”periods before and after the protocol implementation,measuring extubation rates at several time-points from the third until the 24th postoperative *** Of 122 cardiac surgery patients admitted to ICU,13 were excluded as early weaning was considered ***,109 patients were included,54 in the standard and 55 in the intervention *** of surgical interventions and baseline left ventricular function were similar between *** the third to the 12th post-operative hour,the intervention group displayed a higher proportion of patients extubated compared to the standard ***,results were significant only at the sixth hour(58%vs 37%,P=0.04),and not different at the third hour(13%vs 6%,P=0.33).From the 12th post-operative hour time-point onward,extubation rates became almost identical between groups(83%in standard vs 83%in intervention period).CONCLUSION The implementation of a nurse-led protocol for early extubation after cardiac surgery in ICU may gradually lead to higher rates of early extubation.

关键词： Fast-track Extubation protocol Intensive care Mechanical ventilation Implementation strategies

Spatial Analysis of Soybean Plant Height and Plant Canopy Temperature Measured with On-the-Go Tractor Mounted Sensors

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Agricultural Sciences 2019年第11期10卷 1486-1496页

作者： Reginald S. fletcher Daniel K. Fisher Crop Production Systems Research Unit Agricultural Research Service United States Department of Agriculture Stoneville USA Sustainable Water Management Research Unit Agricultural Research Service United States Department of Agriculture Stoneville USA

There is a growing interest in the Open Ag community to use inexpensive sensors controlled by open-source software to measure plant height and plant canopy temperature of agricultural crops. Plant height and plant canopy temperature are key indicators of plant health. This research study reports on an ongoing research initiative to test a compact and inexpensive mobile sensor to measure plant height and plant canopy temperature. The system is controlled by open source software and hardware. The specific objectives for this study were to analyze the relationship between plant height and plant canopy temperature of soybeans (Glycine max L.) measured with the mobile system and to analyze the spatial correlation of the plant height and plant canopy temperature measurements. Data were collected in a soybean plot in 2018 and 2019. Descriptive statistics, Pearson correlation, and geostatistical techniques were used to evaluate the data. A negative statistically significant (p ≤ 0.05) relationship was observed between the plant height and the plant canopy temperature measurements (r = −0.54, 2018;r = −0.37, 2019). Also, both parameters were spatially correlated;however, plant height had a greater spatial continuity than plant canopy temperature. Furthermore, similar patterns were observed for the in-field variability of the plant height and plant temperature maps derived via kriging. Similarities in plant height and plant canopy temperatures were observed from one year to the next, suggesting that the sensor technologies could be used as a historical record for monitoring growth patterns in soybean fields. The sensors and techniques used in this study can be easily adapted to other crops, thus providing two important layers for monitoring plant growth and potentially plant stress.

关键词： Glycine max Ultrasonic Sensors Infrared Thermometer Correlation In-Field Variability

Employing Canopy Hyperspectral Narrowband Data and Random Forest Algorithm to Differentiate Palmer Amaranth from Colored Cotton

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

American Journal of Plant Sciences 2017年第12期8卷 3258-3271页

作者： Reginald S. fletcher Rickie B. Turley Crop Production Systems Research Unit Agricultural Research Service United States Department of Agriculture Stoneville USA Crop Genetics Research Unit Agricultural Research Service United States Department of Agriculture Stoneville USA

Palmer amaranth (Amaranthus palmeri S. Wats.) invasion negatively impacts cotton (Gossypium hirsutum L.) production systems throughout the United States. The objective of this study was to evaluate canopy hyperspectral narrowband data as input into the random forest machine learning algorithm to distinguish Palmer amaranth from cotton. The study focused on differentiating the Palmer amaranth from cotton near-isogenic lines with bronze, green, and yellow leaves. A spectroradiometer was used to acquire hyperspectral reflectance measurements of Palmer amaranth and cotton canopies for two separate dates, December 12, 2016, and May 14, 2017. Data were collected from plants that were grown in a greenhouse. The spectral data were aggregated to twenty-four hyperspectral narrowbands proposed for study of vegetation and agriculture crops. Those bands were tested by the conditional inference version of random forest (cforest) to differentiate the Palmer amaranth from cotton. Classifications were binary: Palmer amaranth and cotton bronze, Palmer amaranth and cotton green, and Palmer amaranth and cotton yellow. Classification accuracies were verified with overall, user’s, and producer’s accuracy. For the two dates combined, overall accuracy ranged from 77.8% to 88.9%. The highest overall accuracies were observed for the Palmer amaranth versus the cotton yellow classification (88.9%, December 12, 2016;83.3%, May 14, 2017). Producer’s and user’s accuracies range was 66.7% to 94.4%. Errors were predominately attributed to cotton being misclassified as Palmer amaranth. The overall results indicated that cforest has moderate to strong potential for differentiating Palmer amaranth from cotton when it used hyperspectral narrowbands known to be useful for vegetation and agricultural surveys as input variables. This research further supports using hyperspectral narrowband data and cforest as decision support tools in cotton production systems.

关键词： Amaranthus palmeri Gossypium hirsutum Cforest Machine Learning

A Miniature Sensor for Measuring Reflectance, Relative Humidity, and Temperature: A Greenhouse Example

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Agricultural Sciences 2018年第11期9卷 1516-1527页

作者： Reginald S. fletcher Daniel K. Fisher Crop Production Systems Research Unit Agricultural Research Service United States Department of Agriculture Stoneville USA

There is a growing interest in using miniature multi-sensor technology to monitor plant, soil, and environmental conditions in greenhouses and in field settings. The objectives of this study were to build a small multi-channel sensing system with ability to measure visible and near infrared light reflectance, relative humidity, and temperature, to test the light reflectance sensors for measuring spectral characteristics of plant leaves and soilless media, and to compare results of the relative humidity and temperature sensors to identical measurement obtained from a greenhouse sensor. The sensing system was built with off-the-shelf miniature multispectral spectrometers and relative humidity and temperature sensors. The spectrometers were sensitive to visible, red-edge, and near infrared light. The system was placed in a greenhouse setting and used to obtain relative reflectance measurements of plant leaves and soilless media and to record temperature and relative humidity conditions in the greenhouse. The spectrometer data obtained from plant leaf and soilless media were compatible with baseline spectral data collected with a hyperspectral spectroradiometer. The greenhouse was equipped with a relative humidity and temperature sensor. The relative humidity and temperature sensor measurements from our sensor system were strongly correlated with the relative humidity and temperature results obtained with the greenhouse sensors...

关键词： Arduino Kale Red Russian Relative Humidity Soilless Media Spectrometer Temperature

Comparing Canopy Hyperspectral Reflectance Properties of <i>Palmer amaranth</i>to Okra and Super-Okra Leaf Cotton

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

American Journal of Plant Sciences 2018年第13期9卷 2708-2718页

Palmer amaranth (Amaranthus palmeri S. Wats.) is a major weed problem of cotton (Gossypium hirsutum L.) production systems in the southern United States. Hyperspectral remote sensing has shown promise as a tool for crop weed discrimination, and there is a growing interest in using this technology for identifying weeds in cotton production systems. Information is lacking on differentiating Palmer amaranth from cotton with an okra leaf structure based on canopy hyperspectral reflectance properties. Two greenhouse studies were conducted to compare canopy hyperspectral reflectance profiles of Palmer amaranth to canopy hyperspectral reflectance profiles of okra and super-okra leaf cotton and to identify optimal regions of the electromagnetic spectrum for their discrimination. Ground-based hyperspectral measurements of the plant canopies were obtained with a spectroradiometer (400 - 2350 nm range). Analysis of variance (ANOVA, p ≤ 0.05), Dunnett’s test (p ≤ 0.05), and difference and sensitivity measurements were tabulated to determine the optimal wavebands for Palmer amaranth and cotton discrimination. Results were inconsistent for Palmer amaranth and okra leaf cotton separation. Optimal wavebands for distinguishing Palmer amaranth from super-okra leaf cotton were observed in the shortwave infrared region (2000 nm and 2180 nm) of the optical spectrum. Ground-based and airborne sensors can be tuned into the shortwave infrared bands identified in this study, facilitating application of remote sensing technology for Palmer amaranth discrimination from super-okra leaf cotton and implementation of the technology as a decision support tool in cotton weed management programs.

关键词： Amaranthus palmeri Discrimination Gossypium hirsutum Remote Sensing Technology