低辐射剂量CT扫描技术在脑动脉3D打印中的应用研究

目的：探讨低辐射剂量CT扫描数据在脑动脉3D打印的可行性研究。方法：将临床拟行脑动脉3D打印的40例患者随机分为2组,每组20例。A组（常规剂量CT扫描方案）：120 kVp,350 mA和滤波反投影（FBP）算法;B组（低剂量CT扫描方案）：80 kVp,自动管电流调制技术（ATCM）和自适应统计迭代重建（ASiR）算法;2组对比剂浓度均为350 mgI/mL。采用两独立样本t检验（非正态分布采用Mann-Whitney U检验）来比较2组的临床资料、辐射剂量、CT DICOM数据客观评价指标及2组方案完成3D打印产物质量的主观评分。结果：A、B 2组患者的临床资料差异均无统计学意义（P＞0.05）。2组的CT辐射剂量差异具有显著统计学意义（P＜0.05）,B组辐射剂量[（1.30 ± 0.47） mSv]较A组[（4.15 ± 0.62） mSv]减少约68.7%。2组脑动脉3D打印结果主观评分差异无统计学意义（P＞0.05）。2组CT DICOM数据客观评价指标：A组的背景噪声（BN）明显高于B组（P=0.000）,而A组的信噪比（SNR）及对比噪声比（CNR）均低于B组（P=0.000）。结论：采用80 kVp、ATCM技术及ASIR算法的数据行脑动脉3D打印,在保证3D打印质量的同时,可以有效减低辐射剂量。     

豚鼠膜迷路蛋白组成分析及免疫转印法检测感音神经性聋患者抗68kD抗体

比较了多种条件提取的豚鼠膜迷路蛋白，发现用十二烷基磺酸钠（ＳＤＳ）或ＴｒｉｔｏｎＸ－１００提取效率高，冻融法较超声粉碎法更可取。成功地建立了免疫转印（Ｗｅｓｔｅｒｎｂｌｏｔ）法，并初步运用于血清抗膜迷路蛋白抗体的检测。４２例不明原因感音神经性聋患者中１６例患者血清中抗６８ｋＤ抗体阳性，同时伴有ＩｇＧ、ＩｇＭ、ＩｇＡ升高。部分正常对照组血清中也存在该抗体，但反应弱，重复性差。     

儿童肾小球疾病不同标本转化型生长因子-β1检测结果的比较

目的　比较评价儿童肾小球疾病血浆、血清、尿液不同标本的转化型生长因子 β1(TGF β1)水平。方法　用ELISA方法测定 30例轻微病变、30例系膜增生性肾小球肾炎、2 4例IgA肾病、2 4例局灶节段性肾小球硬化患儿和 30例健康对照组儿童血浆、血清、尿液中的TGF β1水平。结果　尿液标本的TGF β1水平对各组的诊断有显著意义 (P <0 0 5 ) ,而血浆、血清标本没有诊断意义 (P >0 0 5 )。血浆测定TGF β1灵敏度较血清好。血浆、尿液指标有较好的相关性 (r=0 85 ,P <0 0 5 ) ;血清与尿液仅有一定的相关性 (r=0 5 3,P <0 0 5 ) ;血浆与血清无显著相关性 (r =0 4 9,P >0 0 5 )。结论　尿液为检测肾炎患儿TGF β1水平的较好指标 ,血浆次之 ,血清最差。     

基于5-LOX体外代谢途径的火绒草抗炎活性部位筛选

目的:筛选火绒草中的抗炎活性部位。方法:采用系统溶剂法按照极性由低到高的顺序分离得到火绒草石油醚提取物、乙酸乙酯提取物、正丁醇萃取物、水提取物。采用酶联免疫法(ELISA)建立花生四烯酸(AA)的5-脂氧合酶(5-LOX)体外代谢途径,检测火绒草提取物抑制5-LOX活性的能力。结果:火绒草乙酸乙酯提取物对5-LOX活性有76.92%强度的抑制作用。结论:火绒草乙酸乙酯提取物具有较强的抗炎活性,可作为潜在的抗炎活性成分筛选药物。     

Normalizing GDNF expression in the spinal cord alleviates cutaneous hyperalgesia but not ongoing pain in a rat model of bone cancer pain

Bone cancer pain (BCP) is the most common complication in patients with bone cancer. Glial cell line‐derived neurotrophic factor (GDNF) is believed to be involved in chronic pain conditions. In this article, the expression and roles of GDNF were studied in a rat model of BCP induced by tibia injection of Walker 256 rat mammary gland carcinoma cells. Significant mechanical and thermal hyperalgesia and ongoing pain were observed beginning as early as day 5 post injection. The expression level of GDNF protein examined on day 16 after tibia injection was decreased in the L3 dorsal root ganglion (DRG) and lumbar spinal cord, but not in other spinal levels or the anterior cingulate cortex. Phosphorylation of Ret, the receptor for GDNF family ligands, was also decreased. Furthermore, normalizing GDNF expression with lentiviral vector constructs in the spinal cord significantly reduced mechanical and thermal hyperalgesia, spinal glial activation, and pERK induction induced by tibia injection, but did not affect ongoing pain. Together these findings provide new evidence for the use of GDNF as a therapeutic treatment for bone cancer pain states.     

非典型帕金森病相关疾病的临床诊断思路

目的 探讨非典型帕金森病(APD)相关疾病的临床诊断思路.方法 通过回顾性分析笔者医院2006～2011年收治的48例APD相关疾病患者的临床资料包括病史、体格检查、临床表现、实验室检查、影像学检查、认知功能评估、左旋多巴(L-dopa)试验结果,复习文献,总结分析临床资料特征,并依据APD相关疾病的诊断标准作出临床诊断.结果 48例患者中,肌张力增高42例、震颤40例、运动迟缓39例、姿势反射异常32例、步态异常29例、直立性低血压13例、腱反射亢进11例、认知功能障碍11例、垂直性凝视麻痹和球麻痹各10例、共济失调和病理征阳性各8例、角膜K-F环7例、视幻觉5例、一侧肢体忽略并失用3例;肝功能异常9例、血小板减少8例、血清铜蓝蛋白降低7例、凝血功能异常5例;头颅CT:基底核区低密度影19例,脑室扩大17例,脑萎缩14例;头颅MRI:基底节区异常信号30例,脑室扩大20例,弥漫性脑萎缩18例,脑干和小脑萎缩15例,海马萎缩7例,双侧苍白球T2高信号4例.壳核“裂隙征”8例,脑桥“十字征”7例,中脑“蜂鸟征”6例;L-dopa试验反应不良46例;蒙特利尔认知评估量表(MoCA)总分＜26分23例.出院诊断:多系统萎缩(MSA)18例、进行性核上性麻痹(PSP)10例、Wilson病(WD)7例、路易体痴呆(DLB)6例、伴帕金森综合征(PS)的阿尔茨海默病(AD)5例和皮质基底核变性(CBD)2例.结论 APD相关疾病间,虽然临床表现有许多相似之处,但临床特征、诊断标准及治疗转归各不相同,正确区分十分必要.     

普高与空军青航校毕业生抗荷体质差异

目的 对比青少年航空学校学员与普通高中生招飞抗荷体质相关指标差异,探索青少年航空学校抗荷体质训练成果并为训练方案优化提供科学依据。方法 随机抽取参加2022年空军招飞医学选拔定选阶段的部分青航校高三学员与同年级普通高中生作为研究对象,青航校学员按照既定培养方案,在高中阶段开展专项抗荷体质训练,并通过问卷调查收集普通高中生体育锻炼情况,纳入身体尺寸、身体成分、肌肉力量等指标进行对照研究,采用SPSS.26进行统计学分析。结果 青航校学员身高、四肢长、平静胸围、体质量均显著高于普通高中生(P＜0.05),二者坐高无统计学差异。青航校学员SMI显著高于普通高中生(P＜0.05),但体脂率对比无显著差异(P＞0.05);青航校学员背力与腿力均值/峰值显著高于普通高中生(P＜0.05);SMI与抗荷力量呈显著正相关,体脂率与抗荷力量不存在显著相关。青航校学员与普通高中生SMI分布存在差异,青航校学员的高SMI比例更高、低SMI比例更低(P＜0.05),而青航校与普通高中生体脂率分布无统计学差异(P＞0.05);结论 青航校抗荷体质训练在抗荷相关肌肉力量提高方面成效显著,但是在体脂率控制方面仍存在改进空间,未来青航校抗荷体质训练需要兼顾肌肉训练与体脂控制。     

Consumption of Dietary Fiber with Different Physicochemical Properties during Late Pregnancy Alters the Gut Microbiota and Relieves Constipation in Sow Model

Constipation is a common problem in sows and women during late pregnancy. Dietary fiber has potential in the regulation of intestinal microbiota, thereby promoting intestinal motility and reducing constipation. However, the effects of fibers with different physicochemical properties on intestinal microbe and constipation during late pregnancy have not been fully explored. In this study, a total of 80 sows were randomly allocated to control and one of three dietary fiber treatments from day 85 of gestation to delivery: LIG (lignocellulose), PRS (resistant starch), and KON (konjaku flour). Results showed that the defecation frequency and fecal consistency scores were highest in PRS. PRS and KON significantly increased the level of gut motility regulatory factors, 5-hydroxytryptamine (5-HT), motilin (MTL), and acetylcholinesterase (AChE) in serum. Moreover, PRS and KON promoted the IL-10 level and reduced the TNF-α level in serum. Furthermore, maternal PRS and KON supplementation significantly reduced the number of stillborn piglets. Microbial sequencing analysis showed that PRS and KON increased short-chain fatty acids (SCFAs)-producing genera Bacteroides and Parabacteroides and decreased the abundance of endotoxin-producing bacteria Desulfovibrio and Oscillibacter in feces. Moreover, the relative abundance of Turicibacter and the fecal butyrate concentration in PRS were the highest. Correlation analysis further revealed that the defecation frequency and serum 5-HT were positively correlated with Turicibacter and butyrate. In conclusion, PRS is the best fiber source for promoting gut motility, which was associated with increased levels of 5-HT under specific bacteria Turicibacter and butyrate stimulation, thereby relieving constipation. Our findings provide a reference for dietary fiber selection to improve intestinal motility in late pregnant mothers.     

Numerical Simulation and Experimental Validation of Squeeze Casting of AlSi9Mg Aluminum Alloy Component with a Large Size

The squeeze casting process for an AlSi9Mg aluminum alloy flywheel housing component was numerically simulated using the ProCAST software, and orthogonal simulation tests were designed according to the L16 (4) ⁵ orthogonal test table to investigate the alloy melt flow rule under four factors and four levels each of the pouring temperature, mold temperature, pressure holding time and specific pressure, as well as the distributions of the temperature fields, stress fields and defects. The results showed that the flywheel housing castings in all 16 test groups were fully filled, and the thinner regions solidified more quickly than the thicker regions. Hot spots were predicted at the mounting ports and the convex platform, which could be relieved by adding a local loading device. Due to the different constraints on the cylinder surface and the lower end surface, the solidification was inconsistent, the equivalent stress at the corner junction was larger, and the castings with longer pressure holding time and lower mold temperature had larger average equivalent stress. Shrinkage cavities were mainly predicted at mounting ports, the cylindrical convex platform, the peripheral overflow groove and the corner junctions, and there was also a small defect region at the edge of the upper end face in some test groups.     

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.