婴儿泪在室内生长的光照范围研究

研究了婴儿泪适宜生长的光照范围问题。通过测定试验房间光照的分布图 ,选择试验房间内具有代表性的光区进行栽培试验。实验环境温度为 15～ 2 5℃ ,湿度为 33%～ 6 9%。经栽培 4 0d后 ,用LI 6 4 0 0测定其不同光强下的光合特性 ,计算光补偿点、光饱和点、最大净光合速率。同时测定不同试验区植株的枝长与叶片数量的生长量。结果表明 :婴儿泪在 >8 5μmol·m-2 ·s-1～ <2 99 0 μmol·m-2 ·s-1(4 2 5～ 14 95 0lx ,RH33%～ 6 9% ,温度 15～ 2 5℃ )的光照条件下能够生长     

谷氨酰胺对低剂量电离辐射损害的保护作用

观察小剂量电离辐射条件下大鼠补充谷氨酰胺(Gln)对体内谷胱甘肽(GSH)代谢的影响。SD雄性大鼠受照射后经饲料补充2%Gln。照射源为60Co;剂量率6×10-2Gy/h,1h/d,5d/周,累积剂量1.5Gy。与对照组相比,受照射大鼠睾丸重量降低,精子畸变率增高,肝脏GSH含量降低,外周血白细胞计数降低,血清Gln及Glu+Gln含量降低,差异具有显著性,补充Gln则与对照组无明显差异。表明小剂量电离辐射导致大鼠出现可逆性损害,机体的Gln需求有所增加,补充Gln对大鼠的GSH代谢有一定益处。     

Will the Three Gorges Dam affect the underwater light climate of <Emphasis Type="Italic">Vallisneria spiralis</Emphasis> L. and food habitat of Siberian crane in Poyang Lake?

Almost 95% of the entire population of the Siberian crane (Grus leucogeranus) winter in Poyang Lake, China, where they forage on the tubers of the submerged aquatic macrophyte Vallisneria spiralis. The Three Gorges Dam on the Yangtze River may possibly affect this food source of the Siberian crane by affecting the light intensity reaching the top of the V. spiralis canopy. In this study, the photosynthetically active radiation at the top of the V. spiralis canopy (PAR_tc) in Lake Dahuchi was modeled from 1998 to 2006, and the potential impacts of changes in water level and turbidity on the underwater light climate of V. spiralis were analyzed. PAR_tc was calculated from incident irradiance while the losses due to reflection at the water surface, absorption, and scattering within the water column were taken into consideration. The results indicated significant differences in PAR_tc between years. Six years of water level and Secchi disk depth records revealed a seasonal switching of the lake from a turbid state at low water levels in autumn, winter, and spring to a clear state at high water levels during the monsoon in summer. The highest PAR_tc occurred at intermediate water levels, which were reached when the Yangtze River forces Lake Dahuchi out of its turbid state in early summer and the water becomes clear. The intended operation of the Three Gorges Dam, which will increase water levels in May and June, may advance the moment when Lake Dahuchi switches from turbid to clear. We suggest that this might increase production of V. spiralis and possibly improve the food habitat conditions for wintering Siberian crane in Poyang Lake.

浑善达克沙地不同光合途径植物叶片气体交换和水势特征(英文)

以生长于浑善达克沙地上的C3植物白榆(Ulmus pumila)、C4植物沙米(Agriophyllum pungens)和CAM植物钝叶瓦松(Orostachys malacophyllus)3种不同光合途径植物为材料,测定了它们生长期叶片的光合气体交换参数、叶绿素荧光参数和水势,探讨它们对生长环境的生理响应特征.结果表明,白榆和沙米的净光合速率、气孔导度均高于钝叶瓦松,特别是在夏季高温(>40℃)和强光照(>2 100 μmol·m-2·s-1)条件下表现得更加明显.白榆和沙米的光合速率、叶片水势都发生了严重的午休现象,其白天光合速率的降低主要是由于气孔关闭造成的.钝叶瓦松的叶片水势在3种植物中最高,但是白天的光合速率很低;其Fv/Fm值在14:00最低,一天中此时光系统II受伤害最大;CAM物种瓦松的碳固定仅发生在夜间.研究发现,C3植物白榆和C4植物沙米比CAM植物钝叶瓦松对热和高光照有着更强的忍耐力,瓦松固定碳主要发生在生长最快的阶段;CAM植物瓦松为了能够在夏季强光和高温条件下生存,它必须进行高强度的呼吸,仅在早晨和夜间进行碳固定.     

High Expression of SOX2 and OCT4 Indicates Radiation Resistance and an Independent Negative Prognosis in Cervical Squamous Cell Carcinoma

Radiotherapy (RT) as a preoperative or postoperative adjuvant or primary treatment is the most common management modality for locally advanced cervical cancer. Radioresistance of tumor cells remains a major therapeutic problem. Consequently, we aimed to explore if the stem cell biomarkers SOX2 and OCT4 protein could be used to predict radioresistance in patients with locally advanced cervical squamous cell carcinoma (LACSCC). These 132 patients were divided into two groups (radiation-resistant and radiation-sensitive groups) according to progress-free survival (PFS). Using pretreatment paraffin-embedded tissues, we evaluated SOX2 and OCT4 expression using immunohistochemical staining. The percentage of overexpression of SOX2 and OCT4 in the radiation-resistant group was much higher than that in the radiation-sensitive group (p<0.001 and p <0.001, respectively). The patients with high expression of SOX2 and OCT4 showed a shorter PFS than those with low expression. Our study suggests that the expression of SOX2 and OCT4 in tumor cells indicates resistance to radiotherapy and that these two factors were important predictors of poor survival in patients with LACSCC (hazard ratio [95% CI], 2.294 [1.013, 5.195] and 2.300 [1.050, 5.037], respectively; p=0.046 and p=0.037, respectively).     

RAP80 interacts with the SUMO-conjugating enzyme UBC9 and is a novel target for sumoylation

RAP80, a nuclear protein with two functional ubiquitin-interaction motifs (UIMs) at its N-terminus, plays a critical role in the regulation of estrogen receptor alpha and DNA damage response signaling. A yeast two-hybrid screen identified the SUMO-conjugating enzyme UBC9 as a protein interacting with RAP80. The interaction of RAP80 with UBC9 was confirmed by co-immunoprecipitation and GST pull-down analyses. The region between aa 122-204 was critical for the interaction of RAP80 with UBC9. In addition, we demonstrate that RAP80 is a target for SUMO-1 modification in intact cells. Expression of UBC9 enhanced RAP80 mono-sumoylation and also induced multi-sumoylation of RAP80. In addition to SUMO-1, RAP80 was efficiently conjugated to SUMO-3 but was only a weak substrate for SUMO-2 conjugation. These findings suggest that sumoylation plays a role in the regulation of RAP80 functions.     

晋西黄土区果农间作的种间主要竞争关系及土地生产力

以晋西黄土区核桃×花生、核桃×大豆、苹果×花生和苹果×大豆4种典型果农间作模式为研究对象,分析果农间作模式中作物光合有效辐射（PAR）、净光合速率（P_n）、土壤水分和产量情况.结果表明：与农作物单作相比,间作模式中作物的PAR和P_n均出现不同程度的降低,并且离树体越近,PAR和P_n越小;P_n与作物产量呈显著正相关,说明光照是影响作物产量的重要因素之一;从整体趋势来看,核桃间作农作物0～100 cm土壤水分与相应单作模式间无明显差异,而苹果间作农作物0～100 cm土壤水分与相应单作模式间差异显著,说明苹果对作物土壤水分的竞争比核桃剧烈.研究区果农间作的土地利用效率平均提高70%,经济效益平均提高14%,且核桃间作模式优于苹果间作模式.为了提高间作作物产量,应加强水肥管理、增加树体与作物的间作距离或设置根障、定期适当修剪果树并种植耐荫作物.     

The effects of UV-B radiation on loblolly pine. 3. Interaction with CO2 enhancement

Projected depletions in the stratospheric ozone layer will result in increases in solar ultraviolet-B radiation (290–320 nm) reaching the earth's surface, These increases will likely occur in concert with other environmental changes such as increases in atmospheric carbon dioxide concentrations. Currently very little information is available on the effectiveness of UV-B radiation within a CO₂-enriched atmosphere, and this is especially true for trees. Loblolly pine (Pinus taeda L.) seedlings were grown in a factorial experiment at the Duke University Phytotron with either 0, 8.8 or 13.8 kJ m⁻² of biologically effective UV-B radiation (UV-B_BE). The CO₂ concentrations used were 350 and 650 μmol mol⁻¹. Measurements of chlorophyll fluorescence were made at 5-week intervals and photosynthetic oxygen evolution and leaf pigments were measured after 22 weeks, prior to harvest. The results of this study demonstrated a clear growth response to CO₂ enrichment but neither photosynthetic capacity nor quantum efficiency were altered by CO₂. The higher UV-B irradiance reduced total biomass by about 12% at both CO₂ levels but biomass partitioning was altered by the interaction of CO₂ and UV-B radiation. Dry matter was preferentially allocated to shoot components by UV-B radiation at 350 μmol mol⁻¹ CO₂ and towards root components at 650 μmol mol⁻¹ CO₂. These subtle effects on biomass allocation could be important in the future to seedling establishment and competitive interactions in natural as well as agricultural communities.     

重组人IL6／2融合蛋白对6.5Gy照射小鼠造血功能恢复的影响

观察了ｈＦＰＩＬ６／２对６．５Ｇｙγ线照射ＮＩＨ小鼠第１０天造血功能恢复的影响。结果表明：照射小鼠连续４ｄ给予ｈＦＰＩＬ６／２２５０μｇ·ｋｇ－１·ｄ－１,其脾重、ＣＦＵ－８、骨髓有核细胞数及ＣＭ－ＣＦＵ分别比对照组增加５９．０％、２７８．５％、５７．９％和１３８．２％,统计学处理均有显著差异;对此四项指标的改善也明显优于２５μｇ组。另外,２５０μｇ剂量组小鼠外周血象３０ｄ的动态观察结果表明,ｈＦＰＩＬ６／２不但能明显提高红细胞和血红蛋白的最低值,而且能使血小板的恢复提前。提示ｈＦＰＩＬ６／２在促进血小板生成和促进红系造血方面可能具有良好的应用前景。