Self-adaptive integration of photothermal and radiative cooling for continuous energy harvesting from the sun and outer space

The sun (∼6,000 K) and outer space (∼3 K) are two significant renewable thermodynamic resources for human beings on Earth. The solar thermal conversion by photothermal (PT) and harvesting the coldness of outer space by radiative cooling (RC) have already attracted tremendous interest. However, most of the PT and RC approaches are static and monofunctional, which can only provide heating or cooling respectively under sunlight or darkness. Herein, a spectrally self-adaptive absorber/emitter (SSA/E) with strong solar absorption and switchable emissivity within the atmospheric window (i.e., 8 to 13 μm) was developed for the dynamic combination of PT and RC, corresponding to continuously efficient energy harvesting from the sun and rejecting energy to the universe. The as-fabricated SSA/E not only can be heated to ∼170 °C above ambient temperature under sunshine but also be cooled to 20 °C below ambient temperature, and thermal modeling captures the high energy harvesting efficiency of the SSA/E, enabling new technological capabilities.

Heating and cooling are two kinds of significant end uses of thermal energy in society, which exist in various conditions (e.g., space/water heating, space cooling, and industrial processes) and account for 51% of the total final energy consumption (1). For example, the heating and cooling of buildings are responsible for nearly 48% of the building energy consumption, increasing to be the largest individual energy expense (2). Therefore, heat and cool harvesting relying on clean techniques from renewable energy resources has drawn remarkable attention from fields of engineering to material science because it has considerable potential for global energy conservation and greenhouse emission reduction. Thermodynamically, any heat transportation and work-generation process requires a temperature gradient. The hot sun (∼6,000 K) and cold outer space (∼3 K) are the ultimate heat source and heat sink for the Earth. Theoretical analysis reveals that maximal output work can be extracted from nonreciprocal systems based on the temperature difference between the sun and Earth (∼300 K) with an ultimate solar energy harvesting efficiency limit of 93.3%, while a maximal work of 153.1 W·m⁻² can also be obtained on the basis of temperature difference between the Earth and outer space (3, 4). Thus, the sun and outer space are two significant renewable thermodynamic resources for the Earth, which can be effectively utilized for clean heat and cool collection.Photothermal (PT) is a widely used solar thermal collection method that employs solar absorbers to capture solar photons and convert them to heat. Thermal analysis reveals that a good candidate for a solar absorber should have high solar absorptivity and low thermal emissivity simultaneously for efficient solar thermal collection. Various materials, including multilayer metal/ceramic films (5, 6), photonic crystals (7, 8), and metamaterials (9, 10), have been developed for spectrally selective solar absorbers and have been used for real-world applications. Meanwhile, radiative cooling (RC) has re-elicited considerable interest in recent years because it can passively provide clean cooling without any extra energy input (11–14). The waste heat of terrestrial objects can be continuously pumped into the cold outer space, relying on the transparent atmospheric window (i.e., 8 to 13 μm). So, high emissivity within the atmospheric window of materials is necessary for efficient RC, and excellent solar reflection is also important for RC under sunshine. Thus, different materials with the tailored spectrum, such as photonic structures (15–17), structure materials (18), energy-saving paints (19–21), and even metamaterials (22–24), have been reported for passive cooling. On the potential application level, RC implementations also span a range of fields, including passive cooling of buildings (25–27), thermal management of textiles and color surfaces (28–30), atmospheric water harvesting (31), and thermoelectric generation (32, 33). Although the reported PT and RC can generate heat and cold with high efficiency through different spectrally selective materials, most of the approaches are static and monofunctional, which can only provide heating or cooling under sunlight or darkness. Therefore, the dynamical integration of PT and RC for continuously efficient heat and cool harvesting is a new topic for the energy exploitation of the sun and outer space. The tunable combination of PT and RC hybrid utilization has been recently proposed, but mechanical methods such as switching (e.g., flip action) a PT absorber and an RC emitter manually (34) or changing the optical properties of the materials through extra force stimuli (35) are preferred.Herein, a smart strategy for the dynamic combination of daytime PT and nighttime RC is proposed, corresponding to continuously efficient energy harvesting from the sun and rejecting energy to the universe. A spectrally self-adaptive absorber/emitter (SSA/E) with solar absorption of over 0.8 and emissivity modulation capability of regulating from broadband emissivity of 0.25 within the mid-infrared (MIR) region to the selective high emissivity of 0.75 within the atmospheric window is designed and fabricated for the proof of the concept. Outdoor thermal experimental results demonstrate that the SSA/E can be heated to ∼170 °C above ambient temperature in the daytime PT mode and passively cooled to ∼20 °C below ambient temperature in the nighttime RC mode. Moreover, the heat and cool energy gains of the SSA/E system are respectively predicted to be 78% and 103% larger than those of the reference system that combines static and monofunctional PT absorber and RC emitter.     

病程10年以上糖尿病患者发生糖尿病足的危险因素探讨

目的探讨糖尿病病程10年以上患者发生糖尿病足的危险因素,以利于今后有针对性地指导糖尿病患者从初诊阶段就具有良好的遵医行为,减少糖尿病足的发生与发展。方法调查2005年8月-2006年11月门诊就诊及住院患者并选择符合WHO糖尿病诊断标准且糖尿病病程10年以上者,根据有无糖尿病足的临床症状及体征,选取糖尿病足患者50例作为糖尿病足组,非糖尿病足患者50例作为非糖尿病足组,共100例,采用自行设计的问卷调查表,对其一般状况和患病期间日常自我管理能力进行评价和统计学处理。结果糖尿病足组男性比例高于女性（P〈0．005）;糖尿病足组年龄、病程均略高于非糖尿病足组,但差异无统计学意义（P〉0．05）;糖尿病足组文化程度、经济收入均低于非糖尿病足组,差异有统计学意义（P〈0．01）;虽然两组患者日常自我管理能力都不够完善,但相比而言,非糖尿病足组的自我管理能力普遍强于糖尿病足组（P〈0．01或P〈0．05）。结论糖尿病足的发病率男性高于女性;糖尿病病程长是糖尿病足发生的危险因素之一,但不是主要因素;经济收入低和文化程度低的糖尿病患者更易发生糖尿病足;血糖控制不良是发生糖尿病足的重要危险因素;吸烟也是影响糖尿病足发生发展的因素之一;糖尿病患者了解糖尿病足相关知识对预防糖尿病足将起到积极作用。     

血清触珠蛋白在烧伤后B淋巴细胞功能紊乱中的作用

旨在进一步观察烧伤后血清触珠蛋白对Ｂ淋巴细胞功能的影响，以期弄清血清ＨＰ在烧伤后免疫功能紊乱发生机制中的作用。首先采用亲和层析法从烧伤血清纯化ＨＰ，然后在培养的正常小鼠脾细胞中分别按正常血清ＨＰ含量（火箭电泳法：１．２３３ｍｇ／ｍｌ）和烧伤血清ＨＰ含量（火箭电泳法：９．４０７ｍｇ／ｍｌ）加入纯化ＨＰ，观察ＨＰ对美洲商陆和脂多糖诱导的脾细胞ＩｇＧ产生能力的影响，用ＥＬＩＳＡ检测培养细胞上清ＩｇＧ含量     

严重烧伤后渗透分子清除率和自由水清除率变化及其临床意义

本文测定了59例不同烧伤面积病人血、尿晶体渗透压,计算渗透分子清除率(Cosm)和自由水清除率(C_(H_2O))并进行了动态观察。结果发现随着烧伤面积增加,血晶渗压(Posm)和C_(H_2O)升高,而尿晶渗压(Uosm)和Cosm下降,尤以TBSA>80％组变化最为显著,ARF组较non—ARF变化明显。死亡病人生前Posm、C_(H_2O)明显高于而Uosm、Cosm明显低于存活病人,且Posm、C_(H_2O)增加与Uosm、C_(H_2O)降低往往同时存在。测定Posm、Uosm、Cosm、C_(H_2O)对严重烧伤后肾功能损害监测、判定病情及估计预后均有积极的指导意义     

He—Ne激光治疗大白鼠实验性甲状腺功能亢进的组织形态学观察

本文报道了我们给Ｗｉｓｔｅｒ大鼠服用复方碘溶液，促使其产生甲状腺功能亢进症状，然后用Ｈｅ－Ｎｅ激光对病灶局部进行照射治疗；同时用甲亢大鼠未照激光组、正常大鼠照射激光组作对照，分别于治疗后的３、１０、２０天处死，观察其组织学变化，研究结果发现，在适量Ｈｅ－Ｎｅ激光的作用下，使甲状腺分泌激素的功能得到调节，甲亢被控制。     

烟雾吸入伤后内皮素─1水平的变化及意义

目的：观察大鼠烟雾吸入伤后血浆及支气管肺泡灌洗液（ＢＡＬＦ）中内皮素。１（ＥＴ－１）含量的动态变化，以探讨其与急性吸入性肺损伤发生发展的关系。方法：采用大鼠烟雾吸入伤模型，分别检测了正常对照及致伤２、６、１２和２４小时动物的动脉血气、肺水量、静态肺顺应性（Ｃｓｔ）、ＢＡＬＦ中总蛋白（ＴＰ和白蛋白（Ａｌｂ）、以及血浆和ＢＡＩＦ中ＥＴ－１量。结果：动物吸入伤后出现急性呼吸衰竭和严重肺水肿，Ｃｓｔ显著降低，ＢＡＩＦ中ＴＰ及Ａｌｂ进行性升高；血浆及ＢＡＬＦ中ＥＴ－１水平亦明显增加，且血浆ＥＴ－１的变化与Ｃｓｔ及ＢＡＬＦ中ＴＰ的改变相关显著。结论：ＥＴ－１在烟雾吸入伤后肺血管通透性增加和肺功能损害中可能有重要作用。     

Transrektale dreidimensionale Sonographie

In 3-D transrectal ultrasound it is possible, for the first time, to investigate the region of interest in three planes simultaneously. Exact examination of the organs of the small pelvis as well as of pathologic changes in the region of the pelvic floor can be performed with this new imaging technique. The bulbourethral glands can be investigated routinely, which enables the diagnosis of cysts of these glands. The prostatic zones, their relations as well as the growth of the transitional zone during the development of benign prostatic hyperplasia can be visualized. Furthermore, 3-D transrectal ultrasound allows investigation of morphology and function of the rhabdosphincter. The contractility of the muscle can be quantified. 3-D ultrasound guided puncture and drainage of prostatic abscesses represents a minimally invasive therapeutic modality. This technique can be used to place needles as well as implants in the lower urinary tract. Generally, 3-D transrectal ultrasound offers new diagnostic and therapeutic possibilities.     

人工关节置换治疗创伤性手指近侧指间关节缺损

目的 探讨人工关节假体置换治疗创伤性近侧指间关节缺损畸形的可行性,评价其术后疗效. 方法 自2007年9月至2010年11月,对10例创伤性近侧指间关节缺损畸形病例二期行人工关节置换术,示指5例,中指4例,环指1例,其中再造手指1例. 结果 10例患者手术顺利,伤口一期愈合,术中、术后未发生任何并发症.所有患者均获8个月到3年的随访,置换的近侧假体关节外观和运动功能良好,伸屈活动范围50°～ 80°.根据中华医学会手外科学会上肢部分功能评定试用标准评定,本组10例手功能评定:优6例,良3例,可1例. 结论 人工关节假体置换治疗创伤性手指近侧指间关节缺损畸形具有手术操作简便、创伤小、恢复快的优点,是一种较为有效的新方法.     

NANOG Alleviates the Damage of Human Hair Follicle Mesenchymal Stem Cells Caused by H_2O_2 through Activation of AKT Pathway

Objective To explore the protective effect of NANOG against hydrogen peroxide(H_2O_2)-induced cell damage in the human hair follicle mesenchymal stem cells(hHF-MSCs). Methods NANOG was expressed from a lentiviral vector, pLVX-IRES-ZsGreen. NANOG hHF-MSCs and vector hHF-MSCs were treated with 400 μmol/L hydrogen peroxide(H_2O_2) for 2 h, the cell survival rate, cell morphology, ROS production, apoptosis and expression of AKT, ERK, and p21 were determined and compared. Results Our results showed that NANOG could activate AKT and upregulate the expression of p-AKT, but not p-ERK. When treated with 400 μmol/L H_2O_2, NANOG hHF-MSCs showed higher cell survival rate, lower ROS production and apoptosis, higher expression of p-AKT, higher ratio of p-AKT/AKT. Conclusion Our results suggest that NANOG could protect hHF-MSCs against cell damage caused by H_2O_2 through activating AKT signaling pathway.     

壳聚糖-明胶-果胶仿生网络膜对间充质干细胞增殖和矿化的影响

目的：探讨采用壳聚糖、明胶和果胶制备的仿生网络膜对间充质干细胞（MSCs）增殖和矿化的影响,评价其用于构建组织工程骨的可行性。方法：采用仿生学方法,将壳聚糖、明胶和果胶按照一定比例制作成新型仿生网络膜。实验分为对照组（MSCs+常规培养基）、材料组（MSCs+网络膜+常规培养基）和材料+成骨诱导培养基（OS）组（MSCs+网络膜+OS培养基）。倒置相差显微镜下观察细胞形态表现,扫描电镜（SEM）观察细胞生长及细胞外基质分泌情况,MTT法检测细胞增殖情况（MSCs分为阴性对照组和材料组,分别以空白培养液和含材料的培养液培养）,茜素红染色检测细胞中钙无机物表达情况,实时聚合酶链反应（Real time-PCR）测定细胞中骨钙素（OC） mRNA和骨桥蛋白（OPN） mRNA表达水平。结果：网络膜材料呈半透明薄膜状,倒置相差显微镜下MSCs为短梭形,细胞成簇状聚集生长。SEM下观察,细胞培养第7天可见梭形细胞;培养第14天时细胞数量增多,以伪足状突起锚定于材料表面;培养第21天时,细胞聚集并分泌大量细胞外基质。材料组细胞增殖水平与阴性对照组比较差异无统计学意义（P>0.05）。茜素红染色,网络膜上细胞被染成橘红色。Real time-PCR法,材料组和材料+OS组MSCs中OC mRNA在接种后第7和14天时表达水平较低,第21天时其表达水平明显升高,达到峰值;OPN mRNA在第7天明显表达,第14天时表达水平达峰值,第21天略有下降;与对照组比较,不同时间点材料组和材料+OS组细胞中OC mRNA和OPN mRNA表达水平明显升高（P<0.01）,而材料组与材料+OS组比较差异无统计学意义（P>0.05）。结论：壳聚糖-明胶-果胶仿生网络膜具有良好的生物相容性,MSC在其表面可正常生长和增殖,在不加诱导剂的情况下可以诱导MSCs表达矿化相关的基因和蛋白。