β-淀粉样多肽自聚集抑制剂的电化学筛选方法研究

β-淀粉样多肽（Amyloidbeta,Aβ）的聚集物具有神经细胞毒性,可导致神经元凋亡,从而诱导阿尔茨海默症（Alzheimer’s disease,AD）的发生。能够抑制AB自聚集行为的化合物称为AB自聚集抑制剂。该抑制剂可抑制Aβ有毒聚集物的产生,从而降低Aβ所引起的神经细胞毒性,对AD病有一定的治疗效果。因此。筛选AB自聚集抑制剂对于AD的治疗有着重要的意义。在数以千万计的化合物中,要筛选出对Aβ自聚集有抑制效果的化合物需要借助众多的仪器和研究方法。该文总结了筛选AB自聚集抑制剂的几种方法．重点综述了几种低成本、快速、灵敏的电化学筛选方法。Aβ自聚集抑制剂的筛选对临床上AD病的治疗提供了理论基础,为治疗AD病这一复杂科学问题的研究起到了促进作用。     

Antidiabetic Drugs in the Treatment of Alzheimer’s Disease

The public health burden of type 2 diabetes mellitus and Alzheimer’s disease is steadily increasing worldwide, especially in the population of older adults. Epidemiological and clinical studies suggest a possible shared pathophysiology between the two diseases and an increased risk of AD in patients with type 2 diabetes mellitus. Therefore, in recent years, there has been a substantial interest in identifying the mechanisms of action of antidiabetic drugs and their potential use in Alzheimer’s disease. Human studies in patients with mild cognitive impairment and Alzheimer’s disease have shown that administration of some antidiabetic medications, such as intranasal insulin, metformin, incretins, and thiazolidinediones, can improve cognition and memory. This review aims to examine the latest evidence on antidiabetic medications as a potential candidate for the treatment of Alzheimer’s disease.     

敏化时间对国产5083-H116铝合金组织与性能的影响

针对国产8 mm厚5083-H116铝合金,研究了敏化时间对其组织和性能的影响。结果表明,随着敏化时间的延长,5083铝合金微观组织中越来越多的β相（Al₃Mg₂）沿晶界析出,并且形成大量的网状结构;5083铝合金腐蚀电位降低,晶间腐蚀倾向性持续升高,强度降低,伸长率提高。     

The effect of lithium fluoride on the thermal stability and thermoluminescence properties of borosilicate glass and glass-ceramics

The oxyfluoride glass and glass-ceramics from the LiF-B₂O₃-SiO₂ system are developed. The stable glass can be produced in the range of 20–40 mol% LiF. The effect of LiF admixture on the thermal stability of the glass as well as the thermoluminescence (TL) properties such as glow curves shape is studied. The results show that the increase of lithium fluoride content in the borosilicate glass causes efficiency enhancement of the thermoluminescence signal. We have clearly stated that the process of controlled crystallization of the oxyfluoride glasses can lead again to increased intensity of the TL process. The glass-ceramics with 40 mol% LiF reveals similar level of TL signal to commercially used doped LiF material and can be considered as active material for alpha and beta radiation detectors.     

The Effects of Exercise and Activity-Based Physical Therapy on Bone after Spinal Cord Injury

Spinal cord injury (SCI) produces paralysis and a unique form of neurogenic disuse osteoporosis that dramatically increases fracture risk at the distal femur and proximal tibia. This bone loss is driven by heightened bone resorption and near-absent bone formation during the acute post-SCI recovery phase and by a more traditional high-turnover osteopenia that emerges more chronically, which is likely influenced by the continual neural impairment and musculoskeletal unloading. These observations have stimulated interest in specialized exercise or activity-based physical therapy (ABPT) modalities (e.g., neuromuscular or functional electrical stimulation cycling, rowing, or resistance training, as well as other standing, walking, or partial weight-bearing interventions) that reload the paralyzed limbs and promote muscle recovery and use-dependent neuroplasticity. However, only sparse and relatively inconsistent evidence supports the ability of these physical rehabilitation regimens to influence bone metabolism or to increase bone mineral density (BMD) at the most fracture-prone sites in persons with severe SCI. This review discusses the pathophysiology and cellular/molecular mechanisms that influence bone loss after SCI, describes studies evaluating bone turnover and BMD responses to ABPTs during acute versus chronic SCI, identifies factors that may impact the bone responses to ABPT, and provides recommendations to optimize ABPTs for bone recovery.     

在多孔α-Al2O3陶瓷管上制备β沸石膜的研究

以TEAOH(四乙基氢氧化铵)为模板剂,采用预涂晶种的二次水热合成法在平均孔径3～5 μm的多孔α-Al2O3管状载体的外表面制备了连续致密的β沸石膜,并且用SEM,XRD和气体渗透对所合成的膜进行了表征,结果表明,所合成的膜连续致密,与载体管结合良好,没有大的缺陷.     

Metabolic profile and biological activities of Lavandula pedunculata subsp. lusitanica (Chaytor) Franco: Studies on the essential oil and polar extracts

We investigated the metabolic profile and biological activities of the essential oil and polar extracts of Lavandula pedunculata subsp. lusitanica (Chaytor) Franco collected in south Portugal. Gas chromatography–mass spectrometry (GC–MS) analysis revealed that oxygen-containing monoterpenes was the principal group of compounds identified in the essential oil. Camphor (40.6%) and fenchone (38.0%) were found as the major constituents. High-performance liquid chromatography with diode array detection (HPLC–DAD) analysis allowed the identification of hydroxycinnamic acids (3-O-caffeoylquinic, 4-O-caffeoylquinic, 5-O-caffeoylquinic and rosmarinic acids) and flavones (luteolin and apigenin) in the polar extracts, with rosmarinic acid being the main compound in most of them. The bioactive compounds from L. pedunculata polar extracts were the most efficient free-radical scavengers, Fe²⁺ chelators and inhibitors of malondialdehyde production, while the essential oil was the most active against acetylcholinesterase. Our results reveal that the subspecies of L. pedunculata studied is a potential source of active metabolites with a positive effect on human health.     

柠檬酸复合改性对多环芳烃选择性开环铂/Beta催化剂性能的影响

通过水热处理、柠檬酸处理及其复合处理对Beta分子筛进行后改性,并以改性后的载体制得铂/Beta催化剂。采用X射线衍射（XRD）、X射线荧光光谱仪（XRF）、程序升温脱附（NH₃-TPD）、红外吡啶吸附（Py-IR）、骨架铝核磁共振技术（²⁷Al MAS NMR）及骨架硅核磁共振技术（²⁹Si MAS NMR）等表征了改性前后Beta分子筛的物化性质,并考察了改性前后铂/Beta的多环芳烃选择性开环性能。结果表明,Beta分子筛在柠檬酸处理过程中可同时发生络合脱铝与骨架补铝,实现骨架铝的再分布;Beta分子筛在水热处理过程中优先脱除稳定性相对较低的Si（2 Al）处骨架铝,产生骨架缺陷的同时生成一定比例的二次介孔结构;水热-柠檬酸复合处理影响Beta分子筛骨架补铝及骨架铝再分布的效果,水热处理后Beta分子筛中存在更多的骨架缺陷,促进活性Al（OH）₂⁺物种的骨架补铝作用。当Beta分子筛采用水热-柠檬酸复合处理顺序时,骨架补铝及骨架铝再分布效果显著,样品以中强酸为主,且具有较高的B酸量与L酸量的比值,所制备催化剂的多环芳烃选择性开环活性及稳定性最优。     

Chitosan membranes filled by GPTMS-modified zeolite beta particles with low methanol permeability for DMFC

Uniform zeolite beta particles about 800 nm in diameter were synthesized by a hydrothermal method, and functionalized by γ-glycidoxypropyltrimethoxysilane (GPTMS). Subsequently, chitosan (CS) membranes filled by GPTMS-modified zeolite beta particles were prepared, and characterized by SEM, FT-IR, XRD and TGA. Compared with the pure CS and Nafion^®117 membrane, these CS/zeolite beta hybrid membranes show apparently the lower methanol permeability, which could be assigned to the better interfacial morphology and compatibility between the GPTMS-modified zeolite beta particles and chitosan matrix. In all the prepared CS/zeolite beta hybrid membranes, the CS membrane filled by 10 wt.% GPTMS-modified zeolite beta particles exhibits the lowest methanol permeability, which is 4.4 × 10⁻⁷ and 2.2 × 10⁻⁷ cm² s⁻¹ at 2 and 12 M methanol concentration, respectively. The proton conductivity of this hybrid membrane is 1.31 × 10⁻² S cm⁻¹, which is slightly lower than that of the pure CS membrane. The selectivity of CS/GPTMS-zeolite beta membranes is comparable with Nafion^® 117 at 2 M methanol concentration, and much higher at 12 M methanol concentration.     

稀土元素Ce(La)促进的Pt/β催化剂上正庚烷的临氢异构化

采用共浸渍法制备稀土元素Ce、La修饰的Pt/Hβ催化剂,通过比表面积测定(BET)、X线衍射(XRD)、NH3程序升温脱附(NH3-TPD)对催化剂进行表征,在连续流动常压固定床反应器上考察催化剂的正庚烷临氢异构化反应性能。结果表明:催化剂中Ce或La的引入提高了正庚烷转化率,同时还在很大程度上提高了异构化产物的选择性。CePt/Hβ催化剂的最佳组成为Pt负载量(质量分数)0.4%,n(Ce)∶n(Pt)=5∶1,催化剂在230℃的反应温度下表现出很高的正庚烷转化率(61.5%)和异构化选择性(96.7%),明显高于相应的Pt/Hβ催化剂性能(50.6%和82.4%)。另外,在脱铝β沸石及预先负载杂多酸(磷钨酸)的脱铝Y沸石载体上也发现了Ce或La对其催化性能的促进作用。稀土元素Ce和La通过改善催化剂酸性和Pt分散度而起到了助催化作用。