两种石油加工残油对制备可纺丝中间相沥青的影响

用常压液相炭化法制备中间相沥青，并用熔融法检验中间相沥青的可纺性，研究了汽油裂解残油和催化裂化重柴油参混比的不同对中间相沥青的制备速率，产率，中间相含量，显微结构以及可纺性的影响，指出最佳配比。     

芳香族聚酯的相转移催化合成及其介晶态行为的研究——Ⅰ.聚酯的合成及介晶态行为

本文用相转移催化方法合成了四种新颖的芳香族聚酯。对所得聚合物进行了红外光谱、热重分析、偏光显微镜、示差扫描量热仪和解偏振光强等测试,以研究它们的结构和性能。它们的热分解温度都在330℃以上。其中的聚对,对′-1,4,7-三氧杂庚撐基二苯甲酸对苯二酚酯和聚对苯二甲酸对,对′-1,8-二氧杂辛撐基二苯酚酯,呈现向列型相转变,它们的清晰点分别为237℃和327℃。其它两种含双酚A或酚酞基团的聚酯则不存在液晶行为。对实验结果进行了讨论。     

Sildenafil relieves symptoms and normalizes motility in patients with oesophageal spasm: a report of two cases

Oesophageal spasm presents with dysphagia and chest pain. Current treatments are limited by poor efficacy and side effects. Studies in health and oesophageal dysmotility show that sildenafil reduces peristaltic pressure and velocity; however the clinical efficacy and tolerability in symptomatic oesophageal spasm remains uncertain. We provided open-label sildenafil treatment to two patients with severe, treatment resistant symptoms associated with oesophageal spasm. The effects of sildenafil on oesophageal function and symptoms were documented by high resolution manometry (HRM). Patients were followed up to assess the efficacy of maintenance treatment with sildenafil b.i.d. HRM revealed focal and diffuse spasm in the smooth muscle oesophagus that were associated with symptoms in both cases, especially on swallowing solids. Lower oesophageal sphincter function was normal. A therapeutic trial of 25-50 mg sildenafil suppressed oesophageal contraction almost completely for water swallows; however effective, coordinated peristalsis returned with reduced frequency of spasm for solid swallows. Dysphagia and chest pain resolved during the therapeutic trial and efficacy was maintained on maintenance treatment with 25-50 mg sildenafil b.i.d. without troublesome side effects. This report shows that sildenafil can improve oesophageal function and relieve dysphagia and chest pain in patients with oesophageal spasm in whom other treatments have failed.     

Influence of SENSE on image properties in high-resolution single-shot echo-planar DTI.

Limited spatial resolution is a key obstacle to the study of brain white matter structure with diffusion tensor imaging (DTI). In its frequent implementation with single-excitation spin-echo echo-planar sequences, DTI's ability to resolve small structures is strongly restricted by T2 and T2* decay, B0 inhomogeneity, and limited signal-to-noise ratio (SNR). In this work the influence of sensitivity encoding (SENSE) on diffusion-weighted (DW) image properties is investigated. Computer simulations showed that the PSF becomes narrower with increasing SENSE reduction factors, R, enhancing the intrinsic resolution. After a brief theoretical discussion, we describe the estimation of SNR on a pixel-by-pixel basis as a function of R. The mean image SNR behavior is manifold: SENSE is capable of increasing SNR efficiency by reducing the echo time (TE). Each SNR(R) curve reveals a maximum that depends on the amount of partial Fourier encoding used. The overall best SNR efficiency for an eight-element head coil array and a b-factor of 1000 s/mm2 is achieved at R = 2.1 and partial Fourier encoding of 60%. In vivo tensor maps of volunteers and a patient, with an in-plane resolution of 0.78 x 0.78 mm2, are also presented to demonstrate the practical implementation of the parallel approach.     

卡维地洛对不稳定型心绞痛患者血浆炎症因子的影响

目的观察卡维地洛对不稳定型心绞痛（UAP）患者高敏C反应蛋白（hs-CRP）、白介素-6（IL-6）及细胞间可溶性黏附分子1（sICAM-1）水平的影响。方法UAP患者62例采用完全随机化方法分成对照组（n=30）和治疗组（n=32）,在常规抗血小板、扩血管治疗基础上,对照组予美托洛尔（12.5mg,2次/d×3d）口服,治疗组服卡维地洛（6.25mg,2次/d×3d）,在治疗前后分别测定hs-CRP、IL-6、sICAM-1值。结果对照组和治疗组在治疗前hs-CRP、IL-6、sICAM-1均无显著性差异;用药后两组3指标均较用药前显著降低（P<0.05）;治疗组在用药后IL-6、sI-CAM-1显著低于对照组（P<0.05）。同时,用药后两组患者的心率、血压、心肌耗氧量均较用药前显著降低（P<0.05）,治疗组的心肌耗氧量显著低于对照组（P<0.05）。结论卡维地洛可显著降低UAP患者的炎症因子IL-6、sICMA-1水平。     

Comparison of assays for determination of peptide content for lyophilized thymalfasin*

Abstract: Precise determination of the peptide content in drug substance samples depends highly upon the particular peptide compound and methodology used. Four independent methods were evaluated and compared to determine which would produce the best experimental precision for analysis of thymalfasin (thymosin α‐1). Four different methods were evaluated including elemental analysis (CHN), quantitative amino acid analysis (AAA), high‐performance liquid chromatography (HPLC), and Kjeldahl. This study demonstrates that the AAA method is highly variable in one laboratory while quite precise in another laboratory. Similarly, HPLC results depended on the laboratory conducting the study with more precise values obtained under cGMP. On the contrary, the CHN method yielded highly precise [i.e. <2% coefficient of variation (CV)] values. As precise knowledge of protein content is fundamental for the compounding of final pharmaceutical product of a specific potency, the CHN analysis is recommended for peptide content determination of the drug substance thymalfasin.     

血管内皮生长因子在高原脑水肿形成中作用的实验研究

目的:探讨血管内皮生长因子(VEGF)在高原脑水肿形成中的作用。方法:建立大鼠模拟高原模型,应用脑干湿重比率法定量脑水肿情况、应用荧光素钠透过率测定BBB通透性、应用实时荧光定量RT-PCR法检测脑组织VEGF mRNA含量以及应用蛋白印迹法半定量脑组织VEGF含量。结果:大鼠在高原24 h后脑组织含水率明显增高(P<0.05),荧光素钠透过率显著增加(P<0.01);VEGF mRNA转录及其表达显著增高(P<0.001)。结论:VEGF表达在高原脑水肿形成中起重要作用。     

高度近视的病因学研究进展

高度近视发生的内因、外因，包括遗传倾向，相关基因定位，巩膜胶原白体免疫学说，视网膜生物活性物质失调学说，环境因素等，本研究就这些因素对高度近视发病的影响做一综述。现统一的认识有：①高度近视具有明显的遗传倾向。②迄今为止，已找到4个高度近视相关基因，它们的遗传方式均为常染色体显性遗传。③高度近视的巩膜组织病理改变和胶原代谢障碍引发了人们对高度近视免疫相关基因的深入研究。已发现HLAⅡ类基因与部分高度近视具有相关性。④视网膜中存在的生物活性物质直接或间接参与了形觉剥夺性近视的形成。⑤环境因素并非高度近视发病的决定因素，它仅起一定程度的促进作用。将今后的工作重点放在高度近视基因定位的研究，基因表达的调控及巩膜胶原代谢、网膜生物活性物质之间的关系研究上，无疑会进一步揭示高度近视的病因，为防治高度近视开辟新途径。     

NIKKISO DBB-27型血液透析机液路系统工作原理及故障报警分析

分析了NIKKISO DBB-27型血液透析机液路系统的系统结构及各组成部分的工作原理,并对相关故障报警的诊断和排除进行了详细论述,为及时、准确地诊断和排除血液透析机的故障提供了理论基础。     

Efficient high-frequency body coil for high-field MRI.

The use of body coils is favored for homogeneous excitation, and such coils are often paired with surface coils or arrays for sensitive reception in many MRI applications. While the body coil's physical size and resultant electrical length make this circuit difficult to design for any field strength, recent efforts to build efficient body coils for applications at 3T and above have been especially challenging. To meet this challenge, we developed an efficient new transverse electromagnetic (TEM) body coil and demonstrated its use in human studies at field strengths up to 4 T. Head, body, and breast images were acquired within peak power constraints of <8 kW. Bench studies indicate that these body coils are feasible to 8 T. RF shimming was used to remove a high-field-related cardiac imaging artifact in these preliminary studies. P41RR13230