The world trade center clean up and recovery worker cohort study: respiratory health amongst cleanup workers approximately 20 months after initial exposure at the disaster site

OBJECTIVE: Respiratory health among cleanup workers at the World Trade Center (WTC) disaster site was evaluated approximately 20 months after the initial exposure to assess the risk of lower respiratory symptoms. METHODS: In 2003 a self-administered questionnaire requesting information about site experience, current respiratory and historical health, and smoking was sent to 4,546 workers employed at the site (response 25%), and 2103 workers who were never at the WTC (response 12%). RESULTS: As compared with those never at the site, WTC workers were more than three times as likely to report any lower respiratory symptoms (rate ratio = 3.40, 95% confidence interval: 2.33-4.94). CONCLUSIONS: These results suggest an impact on respiratory health related to work experience at the WTC and indicate further monitoring to address potential long-term effects.     

基于中医体质的危险因素探讨高血压前期的社区综合干预模式

目的基于中医体质的危险因素探讨高血压前期的社区综合干预模式效果。方法测定300名来我社区中心体检者血压,将其分为高血压前期组(150例)和健康人群组(150例),采用问卷调查法调查研究对象体质情况,根据调查结果将体检者分为9类中医体质,并采取个性化干预措施。随访2年,比较高血压前期组和健康人群组的高血压前期检出率、血压、体质量指数和行为改善评分。结果经个性化干预后高血压前期组高血压前期检出率显著下降(P<0.01),体质量指数和血压显著改善(P<0.05),行为改善评分显著升高(P<0.05)。结论基于中医体质研究,构建高血压前期危险因素的社区综合干预模式,对于高血压前期的预防和改善具有重要意义。     

复方贞术调脂方对游离脂肪酸诱导的胰岛素抵抗HepG2细胞的作用

目的 探讨复方贞术调脂方(FTZ)对游离脂肪酸(FFA)诱导的胰岛素抵抗HepG2细胞NF-κB-IRS1-GLUT4通路的影响,阐明FTZ缓解胰岛素抵抗的作用机制.方法 采用FFA诱导HepG2细胞使其产生胰岛素抵抗,3个剂量的FTZ干预后,葡萄糖氧化酶法检测HepG2细胞培养液上清液中葡萄糖的含量,酶联免疫法检测HepG2细胞培养液上清液中TNF-α、IL-6的含量,Western blot检测HepG2细胞中NF-κB、IRS1、GLUT4蛋白表达,采用PDTC阻断NF-κB蛋白,测定其下游靶点IRS1的蛋白表达.结果 FTZ可降低细胞上清液中葡萄糖、TNF-α、IL-6的含量,下调NF-κB的蛋白表达,上调IRS1和GLUT4的蛋白表达.阻断NF-κB之后,再加入FTZ,IRS1的蛋白表达量较未阻断时显著降低.结论 FTZ可改善FFA诱导的胰岛素抵抗,其作用机制可能是通过抑制NF-κB介导的IRS1-GLUT4通路来改善胰岛素抵抗.NF-κB是FTZ作用的关键靶点.     

Experimental and Numerical Study of Fracture Behavior of Rock-Like Material Specimens with Single Pre-Set Joint under Dynamic Loading

The Split Hopkinson Pressure Bar (SHPB) is an apparatus for testing the dynamic stress-strain response of the cement mortar specimen with pre-set joints at different angles to explore the influence of joint attitudes of underground rock engineering on the failure characteristics of rock mass structure. The nuclear magnetic resonance (NMR) has also been used to measure the pore distribution and internal cracks of the specimen before and after the testing. In combination with numerical analysis, the paper systematically discusses the influence of joint angles on the failure mode of rock-like materials from three aspects of energy dissipation, microscopic damage, and stress field characteristics. The result indicates that the impact energy structure of the SHPB is greatly affected by the pre-set joint angle of the specimen. With the joint angle increasing, the proportion of reflected energy moves in fluctuation, while the ratio of transmitted energy to dissipated energy varies from one to the other. NMR analysis reveals the structural variation of the pores in those cement specimens before and after the impact. Crack propagation direction is correlated with pre-set joint angles of the specimens. With the increase of the pre-set joint angles, the crack initiation angle decreases gradually. When the joint angles are around 30°–75°, the specimens develop obvious cracks. The crushing process of the specimens is simulated by LS-DYNA software. It is concluded that the stresses at the crack initiation time are concentrated between 20 and 40 MPa. The instantaneous stress curve first increases and then decreases with crack propagation, peaking at different times under various joint angles; but most of them occur when the crack penetration ratio reaches 80–90%. With the increment of joint angles in specimens through the simulation software, the changing trend of peak stress is consistent with the test results.     

Microstructure and characterization of aluminum-incorporated calcium silicate hydrates (C–S–H) under hydrothermal conditions

The phase assembly and microstructure of the aluminum-incorporated CaO–SiO₂–H₂O system, which is technologically important in autoclaved building materials, catalysis and waste management, were investigated using XRD, SEM, FTIR and NMR depending on aluminum addition, reaction temperature and curing time. The content of each phase was obtained using the MAUD program based on the Rietveld refinement. The results revealed that the formation of the tobermorite phase was promoted at Al/(Al + Si) ≤ 0.03, and subsequently retarded by higher aluminum addition, which was corroborated by the presence of more low polymerized and cross-linked (alumino)silicate chains. The phase purity decreased with increasing aluminum addition. Aluminum changed the morphology of tobermorite from plate-like to lath-like and fibrous. About a quarter of the (alumino)silicate chains in the C–S–H structure were linked though a Si–O–Al configuration, and this proportion was almost independent of aluminum addition. Furthermore, only Al[4] substituted for silicon in the aluminum incorporated C–S–H, while Al[6] just exited in the hydrogarnet phase. This work is beneficial for understanding the implication on micro-properties of by-products or admixtures containing aluminum in concrete.

The phase assembly and microstructure of the aluminum-incorporated CaO–SiO₂–H₂O system were investigated using XRD, SEM, FTIR and NMR depending on aluminum addition, reaction temperature and curing time.     

The synthesis of green fluorescent carbon dots for warm white LEDs

Green fluorescent carbon dots (CDs) were synthesized with pyrogallic acid as carbon source by solvothermal method in N,N-dimethylformamide (DMF). During the formation of the CDs, DMF not only serves as solvent for reaction, but also as nitrogen source to participate in the reaction. At the same time, it promotes the formation of large conjugated sp²-domain in CDs. The prepared CDs have an average size of 11.9 nm, excitation-independent emission centered at 520 nm and fluorescence quantum yield of 16.8%. For practical applications, warm white light-emitting diodes were fabricated by combining the CDs/N-[3-(trimethoxysilyl)propyl]ethylenediamine (KH-792) mixture with UV chip, which emitted warm white light with color coordinates of (0.39, 0.47) and a correlated color temperature of 4323 K suitable for indoor lighting.

Green emissive carbon dots synthesized by solvothermal method is used for warm white light-emitting devices.     

Totally room-temperature solution-processing method for fabricating flexible perovskite solar cells using an Nb2O5–TiO2 electron transport layer

Flexible perovskite solar cells are new technology-based products developed by the global solar industry and are promising candidates for realizing a flexible and lightweight energy supply system for wearable and portable electronic devices. A critical issue for flexible perovskite solar cells is to achieve high power conversion efficiency (PCE) while using low-temperature solution-based technology for the fabrication of a compact charge collection layer. Herein, we innovatively introduce niobium ethoxide as a precursor additive to TiO₂ NCs, which allows realization of an Nb₂O₅–TiO₂ electron transport layer (ETL). The presence of Nb₂O₅ remarkably enhances electron mobility and electrical conductivity of the ETLs. In addition, uniform perovskite films are prepared by an annealing-free solution-based method. The excellent performance of the cell is attributed to its smooth film surface and high electron mobility, and performance is verified by the effective suppressions of charge recombination and time-resolved photoluminescence. PCEs of 15.25% and 13.60% were obtained for rigid substrates (glass/fluorine-doped tin oxide) and an indium tin oxide/PET (poly(ethylene terephthalate)) flexible substrate by using a totally room-temperature solution-processing method, respectively.

Flexible perovskite solar cells are new technology-based products developed by the global solar industry and are promising candidates for realizing a flexible and lightweight energy supply system for wearable and portable electronic devices.     

阴茎血流指数(PFI)测定及其临床意义

目的 探讨阴茎血流指数(PFI)在勃起功能障碍(ED)筛查诊断中的临床意义.方法 采用国.产SW-3501男性功能诊断治疗系统中的血流多普勒探测仪测定37例主诉ED患者的左侧桡动脉和阴茎背动脉、双侧阴茎海绵体动脉的血流速度,求得PFI值;对6例PFI>6和随机抽取6例PFI<6的患者分别进行了彩色双功能多谱勒超声检查.结果 阴茎疲软状态下37例患者的PFI值为O.9～8,平均(3.5±0.6).其中有6例PFI>6,平均为(7.4±0.9),31例PFI<6,平均(3.3±0.5);随机抽取6例PFI<6的患者经彩色双功多普勒检查,其中1例诊断为血管性ED,余5例未发现异常;6例PFI>6的患者经彩色双功能多谱勒超声检查5例诊断为血管性ED,其中有1例PFI>8,考虑为动脉性ED.统计学上的诊断试验方法 提示,其灵敏度和特异度均为83.3%,误诊率和漏诊率均为16.7%.结论 PFI的测定对血管性ED的诊断具有筛查意义,它是一种无创、简便、经济和实用的诊断方法 .     

HPLC法测定硝酸毛果芸香碱注射液的含量及有关物质

目的 建立高效液相色谱法测定硝酸毛果芸香碱注射液含量及有关物质.方法 采用高效液相色谱法.色谱柱为Agela-C18,流动相∶甲醇-2.5 mmol·L-1庚烷磺酸钠溶液(含0.14％三乙胺,磷酸调节pH至8.0)(30∶70);检测波长∶220 nm;柱温:30℃;流速:1.0 mL·min-1.结果毛果芸香碱在0.025～0.6 mg·mL-1浓度范围内线性关系良好(r =0.9998);平均回收率为99.7％,RSD为0.45％;供试品溶液在12h内稳定.结论该方法简便、准确、可靠,专属性强,可以用于硝酸毛果芸香碱注射液的含量及有关物质测定.     

超声定量评估结节间沟

目的 探讨超声测量正常成人结节间沟的可行性。方法 对120名健康成人（正常组）、20个成人肱骨大体标本（标本组）及19例肱二头肌长头肌腱脱位患者（脱位组）进行结节间沟超声扫查,分别测量结节间沟深度（D）、顶部宽度（W）及中部宽度（^1/2W）,计算W/D比值并据此对结节间沟进行分型;对3组的结节间沟测值及分型进行比较。结果 正常组中,优势手亚组D为（4.14±0.07）mm,W为（10.22±0.17）mm,^1/2W为（6.46±0.09）mm,W/^1/2W为1.59±0.19;非优势手亚组D为（4.19±0.06）mm,W为（10.26±0.19）mm,^1/2W为（6.33±0.10）mm,W/^1/2W为1.62±0.18,优势手与非优势手结节间沟D、W、^1/2W、W/^1/2W比较,差异均无统计学意义（P均>0.05）。标本组中,D为（4.24±0.10）mm,W为（9.96±0.24）mm,^1/2W为（6.29±0.11）mm;脱位组中,D为（3.15±0.08）mm,W为（14.95±0.26）mm,^1/2W为（8.35±0.16）mm。优势手亚组结节间沟的D、W、^1/2W及结节间沟分型与标本组的差异均无统计学意义（P均>0.05）,而优势手亚组、标本组与脱位组结节间沟测值及分型的差异均有统计学意义（P均<0.01）。结论 超声可清晰显示成人结节间沟形态并进行测量,可作为结节间沟定量评估的有效方法。