The aboveground biomass of desert steppe and its spatiotemporal variation in western Inner Mongolia

A precise understanding of the aboveground biomass of desert steppe and its spatio-temporal variation is important to understand how arid ecosystems respond to climate change and to ensure that scarce grassland resources are used rationally. On the basis of 756 ground survey quadrats sampled in western Inner Mongolia steppe in 2005-2011 and remote sensing data from the Moderate Resolu- tion Imaging Spectroradiometer （MODIS）--the normalized difference vegetation index （NDVI） dataset for the period of 2001-2011--we developed a statistical model to estimate the aboveground biomass of the desert steppe and further explored the rela- tionships between aboveground biomass and climate factors. The conclusions are as follows： （1） the aboveground biomass of the steppe in the research area was 5.27 Tg （1 Tg=1012 g） on average over 11 years; between 2001 and 2011, the aboveground biomass of the western Inner Mongolia steppe exhibited fluctuations, with no significant trend over time; （2） the aboveground biomass of the steppe in the research area exhibits distinct spatial variation and generally decreases gradually from southeast to northwest; and （3） the important factor causing intemnnual variations in aboveground biomass is precipitation during the period from January to July, but we did not find a significant relationship between the aboveground biomass and the corresponding temperature changes. The precipitation in this period is also an important factor influencing the spatial distribution of aboveground biomass （R2=0.39, P〈0.001）, while the temperature might be a minor factor （R2=0.12, P〈0.01 ）. The uncertainties in our estimate are primarily due to uncertainty in converting the fresh grass yield estimates to dry weight, underestimates of the biomass of shrubs, and error in remote sensing dataset.

Performance of single reshaped Judkins left catheter for transradial coronary angiography

Background: To investigate the feasibility of single reshaped Judkins left catheter for transradial coronary angiography. Methods: A total of 198 consecutive patients were enrolled in the first step study. Patients were randomly assigned to brachial type catheter group (BRACT group) or Judkins left catheter group (Judkins group). The inclusion criterion was the left coronary angiography which could be accomplished by either a brachial type catheter or a reshaped Judkins left catheter. The successful procedure was defined as both right and left coronary angiography could be completed with a single reshaped Judkins left catheter or a brachial type catheter. Furthermore, 1873 consecutive patients were continuously enrolled to observe the success rate of single Judkins left catheter for transradial coronary angiography. Results: Of the 198 patients, 191 were finally enrolled in this study according to the inclusion criteria, with 95 patients in BRACT group and96 inJudkins group. There were no significant differences on baseline between the two groups. Procedure success rate was 84.10% with a fluoroscopic exposure time of 3.81 ± 0.43 min in BRA-CT group, and 81.60% with a fluoroscopic exposure time of 4.05 ± 0.48 min in Judkins group (P > 0.05). No severe complications were found in either of the two groups. The success rates of 1869 patients with single Judkins left catheter for transradial coronary angiography were 75.33%. There were no complications in those patients. Conclusions: Transradial coronary angiography with a reshaped single Judkins left catheter is feasible and practical, with an accepted procedure success rate. This method should be worthy of further clinical validation in a larger scale population.

青藏高原植被结构变化反映环境变迁

草地植被结构对于其生产和生态功能至关重要,但大尺度信息严重匮乏.本研究结合多源遥感数据和深度学习,在区域尺度上厘清了青藏高原高寒草地基于群系的植物群落结构空间格局,并比较了其历史变化.过去40年,高寒草甸在高寒草地中的比例从50%上升到69%,反映了变暖变湿的环境变化.此外,高寒草甸和高寒草原中高山嵩草草甸和紫花针茅草原的优势度分别增强到76%和92%.其中,气候因子驱动了紫花针茅草原近些年的分布;高山嵩草草甸近些年的分布则并非完全由气候驱动,人类活动可能起重要作用.本研究首次探索了区域尺度植被结构特征与历史变化,为认识青藏高原草地变化的驱动力及其空间异质性提供了新视角.

缺血性脑卒中介入急救流程与护理要点的构建与应用

目的建立与实施缺血性脑卒中介入微创急救流程与护理要点,探讨应用效果。方法在介入专科病房修订介入微创急救流程与护理要点,应用于缺血性脑卒中急救中。对比2019年12月至2020年7月科室实施前和2020年8月至2021年1月实施后,缺血性脑卒中患者救治情况、患者对医护团队专业能力认可和对护理工作的满意度。结果实施缺血性脑卒中介入微创急救流程与护理要点后,患者血管再通和生活自理人数明显高于实施前;患者对医护团队专业能力认可、对护理工作满意度均明显提高,差异具有统计学意义(P<0.05)。结论构建和实施缺血性脑卒中介入微创急救流程与护理要点,能显著提高患者救治率、对医护团队专业能力认可及对护理工作满意度,使患者在时间窗内得到专业的微创介入救治,保障了安全,促进了患者尽速康复和医护和谐团队的建立。

基于低成本TiN/生物碳泡沫的高效太阳能蒸汽发生器（英文）

利用太阳能产生蒸汽是净化污水或海水的有效方法.本文中,我们将氮化钛纳米颗粒沉积在经过碳化处理的木块上,得到一种新型的双层太阳能蒸汽发生材料. TiN纳米颗粒具有比以往报道过的光热转换材料(如等离子体金属、碳基材料和半导体纳米材料)更好的稳定性、更经济的价格、更低的毒性、更宽和更强的光吸收等多重优点. TiN纳米颗粒的沉积量以及基底的厚度和类型对水的蒸发速率和太阳能-蒸汽转换效率有重要影响.在模拟太阳光强度为1 kW m^(-2)下,该材料具有92.5%的太阳能-蒸汽转换效率,这是已知的木基光热转换材料中的最高效率.此外,该材料具有良好的可重复利用性.

恶性梗阻性黄疸患者经皮肝穿刺胆道引流术后家庭照顾者照护体验的质性研究

目的了解恶性梗阻性黄疸患者的家庭照顾者在经皮肝穿刺胆道引流术(percutaneous transhepatic biliary drainage,PTBD)后照护过程中的照护体验与需求,为制定家庭照顾者的护理干预对策及相关患者指南提供依据。方法应用质性研究的现象学方法,由研究者对恶性梗阻性黄疸PTBD术后1~3个月复查患者的主要家庭照顾者进行30~60 min深入访谈,并现场录音和记录,运用Colaizzi七步分析法进行资料的整理和分析。结果最终纳入本研究的家庭照顾者14例,其在PTBD术后护理过程中存在的主要问题包括:存在各种心理负担重;希望获取疾病相关知识;认为医疗卫生资源缺乏;认为管道相关材料设置不合理,希望得到改进。结论PTBD术后家庭照顾者存在不同程度的心理负担,对于恶性梗阻性黄疸相关疾病知识及PTBD管路维护知识缺乏,医护人员应增加对家庭照顾者的关注度,加强家庭照顾者及患者PTBD术后相关知识宣教,提升家庭照顾者的照护能力以缓解家庭照顾者的照护压力,降低并发症的发生率,减少再入院率,提高患者及家庭照顾者的生活质量。