Stem flow of seed-maize under alternate furrow irrigation and double-row ridge planting in an arid region of Northwest China

Maize is widely planted throughout the world and has the highest yield of all the cereal crops. The arid region of North- west China has become the largest base for seed-maize production, but water shortage is the bottleneck for its long-term sustainability. Investigating the transpiration of seed-maize plants will offer valuable information for suitable planting and irrigation strategies in this arid area. In this study, stem flow was measured using a heat balance method under alternate furrow irrigation and double-row ridge planting. Meteorological factors, soil water content （e）, soil temperature （Ts） and leaf area （LA） were also monitored during 2012 and 2013. The diurnal stem flow and seasonal dynamics of maize plants in the zones of south side female parent （SFP）, north side female parent （NFP） and male parent （MP） were investigated. The order of stem flow rate was： SFP〉MP〉NFP. The relationships between stem flow and influential factors during three growth stages at different time scales were analyzed. On an hourly scale, solar radiation （Rs） was the main driving factor of stem flow. The influence of air temperature （Ta） during the maturity stage was significantly higher than in other periods. On a daily scale, Rs was the main driving factor of stem flow during the heading stage. During the filling growth stage, the main driving factor of NFP and MP stem flow was RH and Ts, respectively. However, during the maturity stage, the environ- mental factors had no significant influence on seed-maize stem flow. For different seed-maize plants, the main influential factors were different in each of the three growing seasons. Therefore, we identified them to accurately model the FP and MP stem flow and applied precision irrigation under alternate partial root-zone furrow irrigation to analyze major factors affecting stem flow in different scales.

Stem sap flow of Haloxylon ammodendron at different ages and its response to physical factors in the Minqin oasis-desert transition zone, China

Haloxylon ammodendron, with its tolerance of drought, high temperature, and salt alkali conditions, is one of the main sand-fixing plant species in the oasis-desert transition zone in China. This study used the TDP30(where TDP is the thermal dissipation probe) to measure hourly and daily variations in the stem sap flow velocity of H. ammodendron at three age-classes(10, 15, and 20 years old,which were denoted as H10, H15, and H20, respectively) in the Minqin oasis-desert transition zone,China, from May through October 2020. By simultaneously monitoring temperature, relative humidity,photosynthetically active radiation, wind speed, net radiation, rainfall, and soil moisture in this region, we comprehensively investigated the stem sap flow velocity of different-aged H. ammodendron plants(H10,H15, and H20) and revealed its response to physical factors. The results showed that, on sunny days, the hourly variation curves of the stem sap flow velocity of H. ammodendron plants at the three age-classes were mainly unimodal. In addition, the stem sap flow velocity of H. ammodendron plants decreased significantly from September to October, which also delayed its peak time of hourly variation. On rainy days, the stem sap flow velocity of H. ammodendron plants was multimodal and significantly lower than that on sunny days.Average daily water consumption of H. ammodendron plants at H10, H15, and H20 was 1.98, 2.82, and 1.91kg/d, respectively. Temperature was the key factor affecting the stem sap flow velocity of H. ammodendron at all age-classes. Net radiation was the critical factor influencing the stem sap flow velocity of H.ammodendron at H10 and H15;however, for that at H20, it was vapor pressure deficit. The stem sap flow velocity of H. ammodendron was highly significantly correlated with soil moisture at the soil depths of 50and 100 cm, and the correlation was strengthened with increasing stand age. Altogether, our results revealed the dynamic changes of the stem sap flow velocity in different-aged H. ammodendron forest stands and its response mechanism to local physical factors, which provided a theoretical basis for the construction of new protective forests as well as the restoration and protection of existing ones in this region and other similar arid regions in the world.

Study on Variation Characteristics and Prediction Model of Stem Sap Flow of Jujube Under Different Injection Irrigation Models

[Objectives]This study was conducted to study the variation laws and characteristics of stem sap flow rate in jujube under the injection irrigation mode,to improve the growth quality of jujube trees.[Methods]According to the characteristics of the growth environment and physiological characteristics of jujube Junzao trees in southern Xinjiang,eight different injection irrigation modes were designed.Through the variation of stem sap flow rate,the most suitable irrigation method for jujube Junzao trees in southern Xinjiang was explored.The variation law of stem sap flow rate of jujube and the effect of meteorological factors on stem sap flow rate of jujube were studied.The variation law of stem sap flow in jujube trees was analyzed,and multiple regression models and time series models were established to predict stem sap flow of jujube trees.[Results]The results showed that the simulation results of the time series model were closer to the actual data,and the model could accurately predict the stem sap flow rate of Junzao.[Conclusions]This study is suitable for the full utilization of water resources in the Tarim Basin in southern Xinjiang,and has important practical significance for analyzing the effect of water stress on the growth and development of jujube trees and precision irrigation.

Stem radial CO_2 conductance affects stem respiratory CO_2 fluxes in ash and birch trees

The CO_2 released from respiring cells in woody tissues of trees can contribute to one of three fluxes:efflux to the atmosphere(E_A),internal xylem sap transport flux(F_T),and storage flux(DS).Adding those fluxes together provides an estimate of actual stem respiration(R_S).We know that the relative proportion of CO_2 in those fluxes varies greatly among tree species,but we do not yet have a clear understanding of the causes for this variation.One possible explanation is that species differ in stem radial CO_2 conductance(g_c).A high g_c would favor the E_A pathway and a low g_cwould favor the F_Tpathway.However,g_chas only been measured once in situ and only in a single tree species.We measured g_cusing two methods in stems of Fraxinus mandshurica Rupr.(ash)and Betula platyphylla Suk.(birch)trees in situ,along with R_S,E_A,F_T and DS.Stem radial CO_2 conductance was substantially greater in ash trees than in birch trees.Corresponding to that finding,in ash trees over 24 h,E_Aconstituted the entire flux of respired CO_2 ,and F_Twas negative,indicating that additional CO_2 ,probably transported from the root system via the xylem,was also diffusing into the atmosphere.In ash trees,F_T was negative over the entire 24 h,and this study represents the first time that has been reported.The addition of xylem-transported CO_2 to E_A caused E_Ato be 9% higher than the actual R_Sover the diel measurement period.Birch trees,which had lower g_c,also had a more commonly seen pattern,with E_A accounting for about 80% of the CO_2 released from local cell respiration and F_T accounting for the remainder.The inorganic carbon concentration in xylem sap was also lower in ash trees than in birch trees:2.7 versus 5.3 mmol L^(-1),respectively.Our results indicate that stem CO_2 conductance could be a very useful measurement to help explain differences among species in the proportion of respired CO_2 that remains in the xylem or diffuses into the atmosphere.

Mixed enzymatic-explant protocol for isolation of mesenchymal stem cells from Wharton’s jelly and encapsulation in 3D culture system

We report combination of explants and enzymatic protocol as mixed enzymatic-explant procedure to faster extraction of MSCs from WJ. Umbilical cords (UC) were collected from Imam Khomini Hospital. For explant outgrowth, 6 - 9 pieces of WJ were transferred onto tissue culture flask and waited for attachment. For mixed enzymatic-explant, 1 cm3 pieces WJ were placed in enzymatic cocktail comprising 4 mg/ml Collagenase Type I and 1 mg/ml Hyaluronidase and 0.1% trypsin-EDTA. Then isolated cells were analyzed for surface cell markers such as CD73, CD31. Isolated 1.0 × 106 MSCs/ml were encapsulated in alginate hydrogel. Cells with MSCs phenotype were isolated from mixed enzymatic-explant and explant procedures within 24 - 48 hrs and 7 - 10 days, respectively. Both of procedures were shown to form clumps and colonies with dense centers. Phenotypic changes gradually appeared as round cell in UC pieces into homogeneous spindle-shaped and typical fibroblast-like shape cells. By using flow cytometery MSCs showed positive for CD73, and negative for CD31. the morphology of viable MSCs in the beads did not significantly show a different morphology pattern before and after the bead formation process. These findings are indicated that when mixed enzymatic-explant procedure is performed MSCs can be isolated faster and much higher from WJ. These finding is important in comparing with time consuming explants culture for isolation of MSCs.

基于FlowJo软件生物信息学降维方法的小鼠骨髓造血干祖细胞流式分析

目的:研究流式细胞术检测小鼠骨髓造血干祖细胞分析方法,探索建立使用流式细胞术结合生物信息学分析小鼠造血干祖细胞的新方法,为实验血液学研究提供基础。方法:使用流式细胞仪进行小鼠骨髓造血干祖细胞流式分析;使用FlowJo软件对造血干祖细胞结果应用t-分布邻域嵌入算法(t-distributed stochastic neighbor embedding,tSNE)、统一流形逼近与投影(uniform manifold approximation and projection,UMAP)和流式自组织特征映射(flow self-organizing feature map,FlowSOM)分析,并对分析结果进行比较,探索通过生物信息学降维方式分析小鼠造血干祖细胞流式结果的新方法。结果:tSNE、UMAP和FlowSOM分析可以通过降维直观地反映群体细胞的抗原表达水平,并对细胞进行分群和聚类。其分析结果与传统流式分析所得细胞群比例相符。结论:流式细胞术结合FlowJo软件建立的小鼠骨髓造血干祖细胞分析方法可以很好地评价造血干祖细胞各群分布和比例,具有较好的稳定性和评价能力。

上海公园绿地常见乔木茎流特征及其影响因素

公园绿地为上海城市提供了重要的生态系统服务,分析典型绿化树种茎流变化规律及其影响因素,探究蒸腾耗水特性,对进一步加强公园绿地维护和管理、提升生态功能具有重要意义。本研究以海湾国家森林公园2种常见乔木香樟(Camphora officinarum)与无患子(Sapindus saponaria)作为观测对象,采用插针式茎流计和自动气象站对树干茎流及周边气象因子开展连续监测,分析不同时间尺度下茎流速率与环境因子的相关关系。结果表明:香樟与无患子茎流均具有昼高夜低特征,香樟茎流速率日变化曲线呈现明显的“几”字形,无患子茎流速率日变化曲线则整体呈现“多峰”状态。与晴天相比,阴天和雨天条件下的香樟、无患子茎流启动、峰值、结束都有所抑制,具有迟起早退的特征。小时尺度下,香樟和无患子茎流速率均与光合有效辐射(Photosynthetically Active Radiation, PAR)、风速(Wind Speed, WS)、温度(Temperature, Ta)和土壤热通量(Soil Heat Flux, SG)呈现极显著正相关(p<0.01),相关性系数绝对值均大于0.65;与湿度(Humidness, RH)呈现极显著负相关(p<0.01),相关性系数分别为-0.89、-0.76。晴天香樟和无患子茎流速率与PAR、Ta、RH和SG具有极显著相关性(p<0.01);阴天香樟和无患子茎流速率除了受到与晴天有显著相关性的因子影响外,还与WS极显著正相关(p<0.01),相关性系数分别为0.84、0.62;受降雨影响,雨天香樟茎流速率与PAR、Ta、土壤体积含水量(Soil Volumetric Water Content, SVMC)、土壤温度(Soil Temperature, ST)和SG呈极显著正相关(p<0.01),土壤环境因子的影响作用凸显;雨天,除了WS外,无患子茎流速率与其他气象因子呈现与晴天和阴天相反的相关性,而受土壤因子的影响与晴天保持一致。研究结论可为区域公园绿地林地建设和管理提供参考。

不同灌溉量对矮化密植苹果树生理特性和苹果产量及品质的影响

【目的】研究不同滴灌量对苹果生理特性和苹果产量及品质的影响。【方法】以新疆阿克苏地区的矮化密植苹果树为研究对象,设置3种滴灌量处理,即:低水W 1(灌溉定额为216 m^(3)/667m^(2));中水W_(2)(灌溉定额为249 m^(3)/667m^(2));高水W_(3)(灌溉定额为282 m^(3)/667m^(2));漫灌为CK(灌溉定额为750 m^(3)/667m^(2))。利用TDP插针式茎流仪测定苹果树茎流速率、Li-6400便携式光合测定仪测定叶片光合参数、HOBO小型气象站采集气象数据、ECH_(2) O水分探头测定-20、-40、-60和-80 cm土壤含水量;测定苹果产量指标(单果重、纵径、横径、果形指数)和品质指标(可溶性糖、总酸、K、Ca、Na、Mg、Cu、Zn、Fe、Mn含量)。【结果】不同灌溉处理茎流速率表现为CK>W_(3)>W_(2)>W 1,不同月份平均茎流速率排序为7月>8月>6月>9月。净光合速率和蒸腾速率均随灌溉量的增加呈先增大后减小的趋势,W_(2)处理的水分利用效率较高。影响苹果树茎流速率的主要气象因子是太阳辐射和大气温度,30~50 cm土层是滴灌灌溉的重要区域。随灌溉量的提高,产量逐渐增加,但W_(2)、W_(3)和CK无显著差异性。灌溉水利用效率随灌溉量增加呈先增大后减小的趋势,W_(2)的灌溉水利用效率最大,较对照CK高出65.59%。W_(2)处理为最佳处理,但在干旱区可以适当多灌溉以提高其产量。【结论】新疆阿克苏地区矮化密植苹果树最佳灌溉处理为W_(2)处理,灌溉定额为249 m^(3)/667m^(2),全年灌溉次数为11次,7月蒸发量较大应及时灌溉。

不同品种和种植密度对新疆棉花蒸腾速率的影响

2022年在新疆乌兰乌苏开展大田试验,设置3个棉花品种(‘中棉979’、‘中棉703’和‘国欣棉’)和2个种植密度(D1:22株·m^(-2);D2:11株·m^(-2))处理,利用热比率法茎流仪测定蒸腾,对比不同天气条件(晴天、雨天)和时间尺度下棉花日均蒸腾量、日蒸腾变化和累计蒸腾的差异,明确北疆地区不同品种、密度下棉花耗水规律。结果表明:(1)种植密度对群体棉花累计蒸腾和日蒸腾速率影响显著,D1种植密度下棉花累计蒸腾和日蒸腾显著提高,3个品种D1种植密度处理下累计蒸腾、日蒸腾速率显著高于D2种植密度处理(平均高51.2%)。(2)棉花品种对单株和群体蒸腾有显著影响,‘中棉703’茎流速率、日蒸腾速率和累计蒸腾高于其他品种。(3)单株棉花蒸腾在日尺度上呈“几”字型变化规律,白天(9:00-21:00)日蒸腾较稳定,夜间由于根压作用仍存在少许茎流;(4)7-9月棉花蒸腾速率和蒸腾量逐月递减,9月棉花日蒸腾曲线逐步向单峰型转变,且白天蒸腾开始时间较晚(10:00),结束较早(20:00)。(5)累计蒸腾与籽棉产量和平均叶面积未呈现显著相关关系。

气举阀流量预测新模型

为解决Thornhill-Craver方法预测气举阀流量不准确的问题,以空气为介质,在气举阀实验平台上开展气举阀流量研究。对2.8、3.2、4.8、6.4 mm阀孔尺寸的气举阀进行实验,得到不同阀孔尺寸下阀杆行程与流量系数、临界压力比的函数关系;通过考虑阀球表面压力随工况条件的动态变化过程,引入阀的打开程度,优化了阀杆行程求解方法;对气举阀过流面积进行建模,利用已知参数分析推导了过流面积计算新方法;在实验及理论分析基础上,建立了气举阀流量预测新模型。研究结果表明:新模型对不同阀孔尺寸及工况条件下气举阀流量预测准确,平均相对误差为3.34%,较Thornhill-Craver方法有了较大提高,对判断气举阀在井下的工作状态及提高气举设计的精度具有重要意义。

北京3种典型树种对降水再分配过程及化学特征的影响

以重瓣榆叶梅(Amygdalus triloba)、刺槐(Robinia pseudoacacia)、杜松(Juniperus juniper)3种树种为研究对象,自制穿透水、树干茎流收集装置,于2021年7月对降水、穿透水和树干茎流进行收集与分析。NH_(4)^(+)、Ca^(2+)、K^(+)、Cl^(-)、NO_(3)^(-)、SO_(4)^(2-)是降水离子的主要组分;降水持续过程中,重瓣榆叶梅的穿透水和树干茎流、刺槐的穿透水以及杜松的茎流离子浓度与持续时间相关。随着降雨时间的持续,穿透水和树干茎流水中大多数离子的浓度都与空地降水离子浓度有相似的趋势。重瓣榆叶梅的穿透水和树干茎流中与滞尘相关的K^(+)、Mg^(2+)、Ca^(2+)离子浓度与其他2种树种有显著差异(P<0.05)。降水淋洗杜松枝干后Ca^(2+)、Mg^(2+)、Cl^(-)、NO_(3)^(-)浓度的变化大于重瓣榆叶梅和刺槐。穿透水和树干茎流中的主要离子是Ca^(2+)、K^(+)、NO_(3)^(-),这可能与实验区域的扬尘、汽车尾气污染等有关。

库布齐沙漠小叶杨和新疆杨树干液流速率对环境因子的响应

采用热扩散探针法,于2021年5—10月对库布齐沙漠小叶杨(Populus simonii)和新疆杨(Populus alba var.pyramidalis)树干液流进行观测,在生长季同步监测其气象因子、土壤水分等指标,分析小时、日和月尺度下树干液流对环境因子(空气温度、相对湿度、饱和水汽压差、太阳辐射、风速、土壤含水量、降雨量)的响应关系。研究结果如下:(1)新疆杨总耗水量(1059.43 kg)高于小叶杨(947.30 kg)。(2)小时尺度上,小叶杨和新疆杨液流速率均与空气温度、相对湿度、饱和水汽压差、太阳辐射、风速、土壤含水量和降雨量等7个环境因子呈极显著相关;日尺度上,两树种液流速率均与空气温度、相对湿度、饱和水汽压差、太阳辐射、风速和土壤含水量等6个环境因子呈极显著相关;月尺度上,小叶杨液流速率与饱和水汽压差、太阳辐射和土壤含水量呈极显著相关,新疆杨液流速率与空气温度、饱和水汽压差和太阳辐射呈极显著相关。(3)建立时间尺度树干液流与环境因子的关系,小时尺度上,小叶杨入选因子依次为空气温度、土壤含水量、饱和水汽压差和太阳辐射,新疆杨入选因子包括太阳辐射、空气温度等7个因子,树干液流的解释率分别为74.9%、75.6%;日尺度上,小叶杨入选因子依次为土壤含水量、空气温度和风速,新疆杨入选因子包括太阳辐射、空气温度、土壤含水量和风速,树干液流的解释率分别为84.3%、80.9%;月尺度上,太阳辐射和风速是小叶杨液流速率的主要影响因子,2个因子可以共同解释小叶杨液流速率变化的99.5%,饱和水汽压差对新疆杨液流速率的影响最大,单独能够解释新疆杨液流速率变化的91.8%。(4)在较小时间尺度上(小时),液流适宜采用仪器直接测定,在大时间尺度上(日、月)可监测环境因子来估算出2个树种的蒸腾耗水量。

不同月龄波尔山羊睾丸中精原干细胞活性及增殖特征研究

[目的]探究不同月龄波尔山羊睾丸中精原干细胞(spermatogonial stem cells,SSCs)在体外培养过程中的活性及增殖特征。[方法]分别采集1、3、5、58月龄的波尔山羊睾丸,通过组织学方法分别观察不同月龄波尔山羊睾丸的发育情况;分别收集不同月龄波尔山羊睾丸组织,利用三步酶消化法分离成单细胞,通过台盼蓝染色观察睾丸消化细胞总数和死亡细胞数;采用0.2%明胶富集差速贴壁法纯化SSCs并培养10 d,通过流式细胞术鉴定细胞悬液纯化前、纯化后及培养10 d后的Thy-1阳性(Thy-1+)细胞数;将纯化的SSCs培养10 d后,采用碱性磷酸酶染色鉴定SSCs克隆,分别计算不同月龄波尔山羊睾丸SSCs形成的克隆数和克隆面积。[结果]睾丸组织学观察发现1月龄波尔山羊曲细精管管腔生殖细胞数量最少,随着波尔山羊月龄的增加,逐渐发育出各级生殖细胞,但58月龄波尔山羊睾丸生精上皮明显退化。不同月龄波尔山羊睾丸组织经过三步酶消化,在纯化前及纯化后获得的睾丸细胞总数以5月龄波尔山羊最高,显著(P<0.05)高于1月龄波尔山羊;不同月龄波尔山羊纯化前及纯化后的睾丸细胞存活率之间均无显著(P>0.05)差异。在纯化前、纯化后的睾丸组织细胞以及培养10 d的纯化SSCs中,Thy-1+细胞数占睾丸细胞总数的比例均以1月龄波尔山羊最高,显著(P<0.05)高于其他月龄波尔山羊。培养10 d后,不同月龄波尔山羊睾丸来源的SSCs克隆均表现为碱性磷酸酶阳性,1月龄波尔山羊睾丸SSCs形成的平均克隆数显著(P<0.05)高于其他月龄波尔山羊,不同月龄波尔山羊的SSCs平均克隆面积无显著(P>0.05)差异。[结论]5月龄波尔山羊睾丸中细胞总数最多,1月龄波尔山羊睾丸中细胞总数最少,但SSCs活性和增殖效率最高。

基于SMA-SVM模型的茎流速率预测温室西瓜蒸腾量

【目的】基于SMA-SVM模型预测温室西瓜需水量。【方法】以西瓜茎流速率与气象因子结合的作为特征变量作为模型输入,建立黏菌算法(Slime mold algorithm,SMA)优化的支持向量机(Support vector machine,SVM)的温室西瓜蒸腾量预测模型。【结果】气象因子与茎流速率共同作为输入要比气象因子单独作为模型输入的蒸腾量预测精度更高,且通过SMA优化后的SVM预测模型预测效果最好。【结论】茎流速率的SMA-SVM蒸腾预测模型在西瓜三个时期的R2和RMSE分别为0.83、0.87、0.92和0.38、0.31和0.15;模型预测值与实际值接近,预测结果可靠。

造血干细胞移植患者层流舱内无呕管理模式的构建及应用

目的构建造血干细胞移植患者层流舱内无呕管理模式并分析其临床应用效果,以期降低造血干细胞移植患者恶心呕吐发生率,提高生活质量。方法基于循证,采用文献查阅、半结构访谈、小组讨论等构建造血干细胞移植患者层流舱内无呕管理模式。便利抽取2022年3月—11月医院造血干细胞移植中心收治的50例患者作为对照组,采用常规护理干预;2022年12月—2023年7月收治的50例患者作为观察组,在对照组的护理措施基础上应用构建的层流舱无呕管理模式进行干预。比较两组患者恶心呕吐分级、呕吐功能性生活指数(FLIE)量表评分、焦虑自评量表(SAS)评分、抑郁自评量表(SDS)评分和满意度。结果观察组恶心呕吐的严重程度较对照组轻,差异有统计学意义(Z=-2.77,P<0.01)。回输干细胞第7天、第14天、第21天,观察组(FLIE)量表评分高于对照组,差异有统计学意义(P<0.01)。回输干细胞第7天和出舱前1天,观察组SAS量表和SDS量表评分低于对照组,差异有统计学意义(P<0.01)。观察组患者满意度得分高于对照组,差异有统计学意义(t=4.89,P<0.01)。结论造血干细胞移植患者层流舱内无呕管理模式合理、可行,能有效降低患者恶心呕吐发生率,缓解焦虑抑郁情绪,改善移植期间的生活质量。

基于特征提取的CNN-BiLSTM长白落叶松树干液流密度预测

【目的】树干液流密度是影响植物蒸腾的重要因素,其大小受太阳辐射、空气湿度、土壤水分等环境变量影响,准确测量或估计树干液流密度对于了解森林的水分利用效率、研究全球气候变化具有重要意义。【方法】本文提出一种基于特征提取的长白落叶松树干液流预测方法。首先,选取黑龙江省佳木斯市孟家岗林场的长白落叶松为试验对象,将林场气象监测站测得的9个环境变量和Granier法所测长白落叶松树干液流密度进构建数据集。其次,通过皮尔逊相关系数方法对环境变量与树干液流密度之间存在的线性关系进行分析。然后,应用转移熵方法对数据进行特征提取,提取出四个主要环境变量作为模型的输入。最后,搭建基于特征数据的CNN-BiLSTM混合模型,将数据集输入模型进行训练与测试。【结果】通过对比试验,将相关系数(R^(2))、均方根误差(RMSE)和平均绝对误差(MAE)作为预测精度的评价指标,CNN-BiLSTM方法在性能表现上优于BP、CNN、CNN-LSTM模型的预测方法。【结论】转移熵方法可以很好地分析环境变量与长白落叶松液流引入时滞后的因果关系,基于转移熵的特征提取构建的CNNBiLSTM模型能有效的提高长白落叶松树干液流的预测精度。

尿源性干细胞的提取及鉴定

目的:对人尿源性干细胞(hUSCs)进行分离提取和鉴定,为干细胞的应用打下基础。方法:无菌操作下收集2例年龄20~40岁的健康成人约200 mL新鲜中段尿,离心法初步提取尿液细胞,用干细胞培养液筛选培养hUSC,细胞传代至第3代时冻存,流式细胞技术鉴定第4代hUSCs表面标志物,用成脂试验检测干细胞的诱导分化能力。结果:2例均提取成功,在培养第7天时成功提取出hUSCs,并体外培养形成集落,流式细胞术鉴定干细胞表面抗原CD44、CD105和CD73呈高表达,CD45和HLA-DR呈低表达,表明具有间充质干细胞的特性,成脂试验检测干细胞具有诱导分化能力。结论:运用特殊的干细胞培养基成功培养出hUSCs并保存,可建立成熟稳定的培养技术和体系。

基于CD44/CD24和ALDH1对人乳腺癌干细胞分离鉴定的方法学研究

目的:通过分子、细胞实验、动物实验三方面研究分别从四类乳腺癌组织样本寻找分离和鉴定筛选乳腺癌干细胞的方法,旨在为乳腺癌干细胞的研究寻找确定的方法,为乳腺癌的治疗提供参考方向。方法:采用DocSense组织单细胞悬液制备方法从乳腺癌组织中获取原代乳腺癌单细胞用于细胞培养,通过采用CD44/CD24和乙醛脱氢酶1(ALDH1)抗体进行流式分选出CD44^(+)/CD24^(-/low)组、ALDH1+组及非干细胞表型CD44-/ALDH1-组的细胞群,分组后的细胞采用乳腺癌干细胞干性鉴定(微球克隆形成实验),MTT实验分别绘制Luminal A型,Luminal B型,HER-2+型,Basal-like型筛选出的CD44^(+)/CD24^(-/low)组、ALDH1+组和CD44-/ALDH1-组细胞生长曲线,最后采用裸鼠成瘤实验及剥离肿瘤组织病理切片采用苏木精-伊红法染色(HE染色)验证所分选出来细胞干性及组织为乳腺癌组织。结果:本研究利用组织单细胞消融技术、干细胞微球形成实验及流式细胞术,成功富集并筛选出4类分子亚型的8种乳腺癌肿瘤干细胞;通过肿瘤微球克隆形成实验、MTT实验鉴定出标记CD44^(+)/CD24^(-/low)、ALDH1+表型的乳腺癌干细胞侵袭性和增殖能力更强;裸鼠皮下荷瘤HE染色进一步证明CD44^(+)/CD24^(-/low)、ALDH1+表型的乳腺癌细胞成瘤能力更强、异质性更明显。结论:CD44^(+)/CD24^(-/low)组、ALDH1+组乳腺癌干细胞干性表达能力较强,可作为乳腺癌干细胞的鉴定和筛选的关键指标,为乳腺癌的治疗提供新的参考方向。

华北土石山区油松生长季夜间液流分配特征

【目的】通过对油松生长季夜间液流特征和环境驱动因素的研究,揭示夜间液流组分拆分特征,探讨夜间液流的组分与气象因子之间的相关关系,以及茎干补水对气象因子的响应,为华北土石山区水资源和水源涵养林管理决策提供理论依据。【方法】以华北土石山区的油松作为研究对象,根据径阶大小选取18棵样树,在2014年生长季运用Granier热扩散探针技术(TDP)持续观测夜间液流,结合称重式蒸渗仪和自制微型蒸渗仪来计算蒸腾量,解析夜间液流的去向;并进行夜间液流与土壤含水量、大气温度、湿度及光合有效辐射等气象因子的相关分析,以确定主要驱动因素。【结果】在6—9月典型晴天,夜间液流速率都呈逐渐降低趋势,18:00—24:00的夜间液流速率高于00:00—05:00,夜间液流主要用于对白天失水过多的茎干进行补水,以至于在24:00时油松茎干储水量基本达到饱和,因此,00:00—05:00夜间液流速率趋于稳定;油松夜间液流用于茎干补水的比例(95.34%)显著高于用于夜间蒸腾量的比例(4.66%);油松夜间茎干补水量与饱和水汽压差呈极显著正相关(R^(2)=0.793,P<0.01),而对土壤含水量变化响应不敏感(R^(2)=0.105,P>0.05),表明夜间液流主要受饱和水汽压影响。【结论】华北土石山区的油松生长季夜间液流随着夜间时间的进行呈现逐渐降低的趋势;绝大部分的夜间液流用于夜间茎干补水,在气象因子中,饱和水汽压是驱动夜间茎干补水及夜间液流的重要因子(P<0.01)。

祁连山排露沟流域不同水文过程水体氮素含量特征

为探明祁连山排露沟流域不同水体中全氮、铵态氮和硝态氮的空间分布特征,本研究在祁连山排露沟流域青海云杉林内对大气降水、穿透雨、树干茎流和河川径流水等不同水文过程中的水样进行采集,测定不同水体中全氮、铵态氮和硝态氮含量。结果表明,研究区内不同水文过程水体的全氮、铵态氮和硝态氮含量在首次产生树干茎流时,全氮和铵态氮含量均呈现出:树干茎流>穿透雨>大气降水>河川径流,硝态氮含量则呈现出:河川径流>树干茎流>穿透雨>大气降水。其他降水事件中不同水体氮素含量的差异显著性没有明显的变化规律。河川径流中的全氮和铵态氮含量均值明显低于大气降水、穿透雨和树干茎流中的全氮和铵态氮含量,但河川径流的硝态氮含量均值明显高于大气降水、穿透雨和树干茎流中的硝态氮含量。相关性分析表明,有机碳与全氮和铵态氮之间均呈极显著正相关(p<0.01),而有机碳与硝态氮的相关性不显著(p>0.05)。