Investigation of optical attenuation imaging using optical coherence tomography for monitoring of scars undergoing fractional laser treatment

We demonstrate the use of the near‐infrared attenuation coefficient, measured using optical coherence tomography (OCT), in longitudinal assessment of hypertrophic burn scars undergoing fractional laser treatment. The measurement method incorporates blood vessel detection by speckle decorrelation and masking, and a robust regression estimator to produce 2D en face parametric images of the attenuation coefficient of the dermis. Through reliable co‐location of the field of view across pre‐ and post‐treatment imaging sessions, the study was able to quantify changes in the attenuation coefficient of the dermis over a period of ～20 weeks in seven patients. Minimal variation was observed in the mean attenuation coefficient of normal skin and control (untreated) mature scars, as expected. However, a significant decrease (13 ± 5%, mean ± standard deviation) was observed in the treated mature scars, resulting in a greater distinction from normal skin in response to localized damage from the laser treatment. By contrast, we observed an increase in the mean attenuation coefficient of treated (31 ± 27%) and control (27 ± 20%) immature scars, with numerical values incrementally approaching normal skin as the healing progressed. This pilot study supports conducting a more extensive investigation of OCT attenuation imaging for quantitative longitudinal monitoring of scars.

En face 2D OCT attenuation coefficient map of a treated immature scar derived from the pre‐treatment (top) and the post‐treatment (bottom) scans. (Vasculature (black) is masked out.) The scale bars are 0.5 mm.     

Characterization of TAP Ambr 250 disposable bioreactors,as a reliable scale‐down model for biologics process development

Demands for development of biological therapies is rapidly increasing, as is the drive to reduce time to patient. In order to speed up development, the disposable Automated Microscale Bioreactor (Ambr 250) system is increasingly gaining interest due to its advantages, including highly automated control, high throughput capacity, and short turnaround time. Traditional early stage upstream process development conducted in 2 ‐ 5 L bench‐top bioreactors requires high foot‐print, and running cost. The establishment of the Ambr 250 as a scale‐down model leads to many benefits in process development. In this study, a comprehensive characterization of mass transfer coefficient (k_La) in the Ambr 250 was conducted to define optimal operational conditions. Scale‐down approaches, including dimensionless volumetric flow rate (vvm), power per unit volume (P/V) and k_La have been evaluated using different cell lines. This study demonstrates that the Ambr 250 generated comparable profiles of cell growth and protein production, as seen at 5‐L and 1000‐L bioreactor scales, when using k_La as a scale‐down parameter. In addition to mimicking processes at large scales, the suitability of the Ambr 250 as a tool for clone selection, which is traditionally conducted in bench‐top bioreactors, was investigated. Data show that cell growth, productivity, metabolite profiles, and product qualities of material generated using the Ambr 250 were comparable to those from 5‐L bioreactors. Therefore, Ambr 250 can be used for clone selection and process development as a replacement for traditional bench‐top bioreactors minimizing resource utilization during the early stages of development in the biopharmaceutical industry. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:478–489, 2017     

云南普洱季风常绿阔叶林优势物种不同生长阶段叶片碳、氮、磷化学计量特征

为探索植物叶片氮(N)、磷(P)、碳(C)生态化学计量特征随植物生长发育的变化规律, 在普洱季风常绿阔叶林中, 选取6种优势植物种(红锥(Castanopsis hystrix)、短刺锥(Castanopsis echidnocarpa)、泥柯(Lithocarpus fenestratus)、截果柯(Lithocarpus truncatus)、西南木荷(Schima wallichii)、茶梨(Anneslea fragrans))采集叶片, 分析其N、P、C含量及化学计量比随植物生长发育的变化。结果显示: 6种植物在不同生长阶段的N含量变化范围为7.90-17.72 mg·g^-1, P为0.34-1.39 mg·g^-1, C为458.48-516.87 mg·g^-1, C:N为28.04-65.70, N:P为11.41-63.50, C:P为355.23-1878.17, 且不同生长阶段6种植物及总体叶片N、P、C含量及其化学计量比变化趋势各异。在变异系数上, N:P比整体变异最大, 为36.46% (变化范围19.19%-91.65%), 其次为C:P, 为34.80% (变化范围15.99%-91.60%), C的整体变异最小, 为3.12% (变化范围1.61%-5.89%)。变异来源分析结果显示, N含量、C含量、C:N、N:P及C:P均主要受植物生长阶段的影响, 而P含量主要受物种与生长阶段的交互作用影响。     

基于MFCC和GMM的昆虫声音自动识别

昆虫的运动、 取食、 鸣叫都会发出声音, 这些声音存在种内相似性和种间差异性, 因此可用来识别昆虫的种类。基于昆虫声音的昆虫种类自动检测技术对协助农业和林业从业人员方便地识别昆虫种类非常有意义。本研究采用了语音识别领域里的声音参数化技术来实现昆虫的声音自动鉴别。声音样本经预处理后, 提取梅尔倒谱系数（Mel frequency cepstrum coefficient, MFCC）作为特征, 并用这些样本提取的MFCC特征集训练混合高斯模型（Gaussian mixture model, GMM）。最后用训练所得到的GMM对未知类别的昆虫声音样本进行分类。该方法在包含58种昆虫声音的样本库中进行了评估, 取得了较高的识别正确率（平均精度为98.95%）和较理想的时间性能。该测试结果证明了基于MFCC和GMM的语音参数化技术可以用来有效地识别昆虫种类。     

不同风浪条件下太湖梅梁湾光合有效辐射的衰减

基于2003年7月12～17日在太湖梅梁湾进行的连续6d原位水下光场观测资料,分析了不同风浪条件下光合有效辐射(PAR)的衰减和真光层深度,探讨了影响水下光合有效辐射的主导因子.结果表明,整个观测期间向下PAR衰减系数为2.63～4.71·m^-1(均值为3.63±0.47·m^-1),对应的真光层深度为0.98～1.75m(均值为1.29±0.18m),显示1.5m以下深度浮游植物、沉水植物基本上无法获取足够的太阳光能进行光合作用.从小风浪到中风浪、大风浪向下PAR衰减系数分别是2.63、3.72和4.37·m^-1,衰减系数分别增加了41%、66%.透明度、PAR衰减系数、真光层深度与悬浮物浓度存在显著性线性相关,并且与悬浮物中无机颗粒物相关性最好,而与叶绿素a、脱镁叶绿素及溶解性有机碳相关性很低.多元逐步线性回归表明,叶绿素a和溶解性有机碳最先被剔除方程,说明在梅梁湾由于风浪扰动引起悬浮物浓度的改变是影响水下光场的主导因素.     

几种植物生长调节物质对大花蕙兰组培原球茎增殖的影响

采用KC 培养基, 分别添加不同浓度的BA、KT、NAA 及KT+NAA 组合, 对大花蕙兰初代培养已分化出的原球茎进行了继代培养。结果发现:①BA 可加快原球茎的增殖速度, 但浓度超过0.5 mg/L 后增殖速度有所下降, 且原球茎变小呈暗绿色。②KT 的促进增殖效果好于BA, 但浓度超过1.0 mg/L 时, 增殖速度也有所下降, 原球茎变小。③NAA 促进原球茎增殖的效果明显好于BA、和KT, 但浓度大于1.0 mg/L 后增殖不再加快, 而且部分原球茎有变褐现象。④在KT 0.5~0.7 mg+NAA 0.7~1.0 mg/L 范围组合的KC 培养基上, 大花蕙兰原球茎增殖的速度和质量是比较理想的。考虑到较低的细胞分裂素和植物生长素有利于植物增殖过程中遗传性的稳定, 选择KT0.5 mg+NAA 0.7 mg/L 的KC 培养基作为大花蕙兰原球茎增殖培养基。     

广东省汉族人群的亚群分析

为调查广东地区汉族人群中是否存在着亚群结构,对来自广州、佛山、东莞、江门和中山-珠海5个不同地区的471随机个体血样本进行15个STR的基因分型,并作Hardy-Weinberg平衡检验,比较群体之间的等位基因频率,计算这个5个地区人群间的共祖系数。结果显示,广东汉族人群没有明显的Hardy-Weinberg不平衡,5个地区人群的等位基因分布均没有差异,他们之间的共祖系数小于0.01。因此,广东地区汉族人群中没有明显的亚群结构。 Abstract:To investigate the subpopulation structure within the Han Population in Guandong area,a total of 471 DNA samples from five populations in Guandong Province,including Guangzhou,Foshan,Dongguan,Jiangmen and Zhongshan-Zhuhai region,were genotyped at 15 STR(short tandem repeats) markers.Hardy-Weinberg tests were performed,allele frequencies were compared,and the genetic coancestry coefficient(FST ) was estimated.The results did not show significant departure from Hardy-Weinberg equilibrium in the total population.Difference of allele frequencies among these populations was not observed,and the coancestry coefficient(FST)was less than 0.01.Subpopulation structure within Han Population in Guandong Province could not be detected.     

奈曼地区灌溉麦田蒸散量及作物系数的确定

利用大型蒸渗仪测定了奈曼地区春小麦(Triticum aestivum L.)全生育期的蒸散量,并引用FAO Penman-Monteith等5种方法计算了相应时期的参考作物蒸散量,比较了FAO Penman-Monteith公式与其它4种方法间的关系,最后运用作物蒸散量和参考作物蒸散量计算了春小麦的作物系数．结果表明,春小麦苗期每周日平均蒸散量小于3mm·d^-1,随着叶面积系数增大,日平均蒸散量达到最大值6．49mm·d^-1(抽穗开花期),最终下降至1．94mm·d^-1(灌浆成熟期);根据试验年份的降雨分布情况,该地区的自然降水不能满足春小麦对水分需求,小麦苗期、拔节期和抽穗开花期水分亏缺比较严重,是田间水分管理的关键时期;与FAO Penman-Monteith公式的计算结果相比较,用Penman公式和FAO-24 Blaney-Criddle公式估算奈曼地区参考作物蒸散量误差较小;奈曼地区春小麦苗期、营养期、生殖期、成熟期4个生长阶段的作物系数分别为0．45、0．90、1．1l和0．52,其中成熟期的作物系数值与FAO-24给出的小麦作物系数值差异较大．     

不同种源桃金娘表型性状多样性研究

为解析桃金娘表型性状多样性及其种源间关系，该文以20个不同来源的桃金娘为研究对象，在同质园栽培条件下，对其营养器官和花器官表型性状进行观测，采用方差分析、变异分析、Shannon-Wiener多样性指数分析和聚类分析等方法，探讨不同种源桃金娘表型性状多样性。结果表明：(1)不同种源桃金娘表型性状存在显著差异(P<0.05),Shannon-Wiener多样性指数均值在1.35以上，表型性状多样性丰富。(2)种源内表型性状变异系数均值在10.81%～63.75%之间，种源间的变异系数均值在13.08%～74.04%之间，种源间变异(23.33%)高于种源内变异(19.79%),营养器官变异(29.52%)高于花器官变异(14.06%)。(3)部分性状存在极显著或显著相关性，株高与分枝数呈极显著负相关，而与叶长、叶宽和叶面积等却呈显著正相关。(4)在欧式距离10处，20个种源桃金娘可分为A、B、C三类，A类包含8个种源，该类种源表现为植株高大、分枝少、叶大和花大等特征；B类包含11个种源，该类种源表现为株高中等、叶较大和花中等等特征；C类仅包含1个种源，表现为植株低矮、分枝多、叶小和...