Miscibility and Intermolecular Specific Interactions in Blends of Poly(hydroxyether sulfone) and Poly(N‐vinylpyrrolidone)

Summary: The blends of poly(hydroxyether sulfone) (PHES) with poly(N‐vinylpyrrolidone) (PVPy) were investigated by means of differential scanning calorimetry (DSC) and FTIR spectroscopy. The miscibility of the blend system was established on the basis of the thermal analysis results. DSC showed that the PHES/PVPy blends prepared by casting from N,N‐dimethylformamide (DMF) possessed single, composition‐dependent glass transition temperatures, indicating that the blends are miscible in the entire composition. The experimental glass transition temperatures have higher values than those calculated on the basis of additive behavior; the variation of the glass transition temperatures of the blends was accounted for by the Kwei equation. FTIR studies indicate that competitive hydrogen bonding interactions exist upon addition of PVPy to the system, which were involved in the self‐ and cross‐association, i.e., ? OH···O?S, ? OH···OH of PHES and ? OH···O?C< of PVPy. The FTIR spectra in the range of the sulfonyl stretching vibrations showed that the hydroxyl‐associated sulfonyl groups are partially “set free” upon addition of PVPy to the system. The IR spectroscopic investigation of both the model compounds and the PHES/PVPy blends suggests that the strength of the hydrogen bonding interactions in the blend system increases in the following order: ? OH···O?S, ? OH···OH and ? OH···O?C<.

Plot of glass transition temperature for PHES/PVPy blends as a function of weight fraction of PVPy. The prediction of the Kwei equation yields the values of k = 1 and q = 122.     

Encoding of electrical, thermal, and mechanical noxious stimuli by subnucleus reticularis dorsalis neurons in the rat medulla

1. In anesthetized rats, recordings were made within the medullary subnucleus reticularis dorsalis (SRD) from neurons that exhibited convergence of nociceptive inputs from the entire body. Neurons with total nociceptive convergence (TNC) responded to suprathreshold percutaneous electrical stimuli (2-ms duration) with an early and a late peak due to activation of A delta- and C-fibers, respectively, no matter which part of the body was stimulated. Neurons with partial nociceptive convergence (PNC) responded to the same stimuli with an A delta-peak regardless of which part of the body was stimulated and with a C-peak of activation from some, mainly contralateral, parts of the body. The characteristics of the responses of these neurons to the application of graded intensities of electrical, thermal, and mechanical stimuli were analyzed. 2. All TNC neurons and 85% of PNC neurons responded to A delta- and C-fiber activation following percutaneous electrical stimulation of the contralateral hindpaw. With regard to A delta-fiber-evoked responses, a linear relationship between the logarithm of the applied current and the magnitude of the responses was found within the 0.25- to 6.0-mA and 0.5- to 24-mA ranges for TNC and PNC neurons, respectively; however, these curves were essentially similar. With regard to C-fiber-evoked responses, such a linear relationship was found within the 1.5- to 6.0-mA range for both types of SRD neurons, although the TNC neurons presented larger C-fiber-evoked responses than did the PNC neurons. 3. TNC and PNC neurons linearly increased their discharges during the application of noxious thermal stimuli to the contralateral hindpaw within the range 44-52 degrees C; the mean responses evoked by noxious heat from TNC neurons were of higher magnitude than those from PNC neurons. The majority of SRD neurons presented long-lasting afterdischarges, especially with the highest temperature employed (52 degrees C). 4. TNC neurons monotonically increased their discharges during graded mechanical or thermal stimulation of the tail. When mechanical stimuli were applied, a linear relationship was found between the logarithm of the strength of the mechanical stimulus and the neuronal discharges, in the 5.3- to 7.4-N/cm2 range. With thermal stimulation, TNC neurons linearly increased their discharges in the 44-52 degrees C range. When increasing amounts of the tail were immersed in a 50 degrees C waterbath, TNC neurons increased their discharges within a restricted range of tail surface areas (0.9-5.7 cm2); further increases in the stimulated surface size were not followed by increases in firing rate.(ABSTRACT TRUNCATED AT 400 WORDS)     

三氧化二锑诱导急性早幼粒细胞白血病细胞凋亡的研究

目的 研究锑剂三氧化二锑（Sb2O3)对早幼粒细胞白血病细胞株NB4凋亡的诱导作用，以寻求早幼粒细胞白血病治疗的新方法。方法 采用细胞生长曲线，形态学及硝基四氮唑蓝（NBT）还原试验，判定NB4细胞的生长，分化及功能。采用细胞周期分析和DNA电泳研究细胞凋亡。结果 Sb2O3能诱导早幼粒白血病细胞凋亡，且具有时间，剂量依赖性。结论 Sb2O3能有效地诱导早幼粒白血病细胞凋亡，提示锑剂诱导细胞半亡的疗法，有望成为临床治疗早幼粒细胞白血病的新方法。     

氧分压在体监测仪的研制

作者报道一种稳定性较高的氧分压在体监测，为医学研究、临床诊断提供一种新的可靠的测试方法及设备，具有较大的应用价值。     

葛花、枳椇子及其配伍对小鼠急性酒精性胃黏膜损伤的保护作用及机制

目的 探讨葛花、枳椇子及其配伍对急性酒精性胃黏膜损伤的改善作用,为进一步开展葛花、枳椇子及其配伍防治酒精致多脏器损伤奠定基础。方法 采用多次灌胃给予56%红星二锅头白酒（15 mL·kg^-1）建立小鼠急性酒精性胃黏膜损伤模型,将120只ICR雄性小鼠随机分为空白组、模型组、奥美拉唑组（0.026 g·kg^-1）、葛花-枳椇子（配伍）高、中、低剂量组（29.2、14.6、7.3 g·kg^-1）、葛花组（19.5 g·kg^-1）、枳椇子组（19.5 g·kg^-1）共8个组,每组15只,动物适应性喂养1周后,按10 mL·kg^-1预给相应药物3 d,从第4天开始,给药1 h后按15 mL·kg^-1灌胃二锅头白酒,空白组给予相同体积去离子水,记录小鼠醉酒和醒酒时间,连续给药给酒3 d,末次给药1 h后摘眼球处死;气相色谱仪测定各组小鼠血清中乙醇体积分数,紫外-可见分光光度计检测各组小鼠胃黏膜中乙醇脱氢酶（ADH）活性;苏木素-伊红（HE）染色观察胃黏膜病理变化;酶联免疫吸附测定法（ELISA）检测各组小鼠血清中炎症因子含量;实时荧光定量聚合酶链式反应（Real-time PCR）检测核转录因子-κB（NF-κB）p65和NF-κB抑制蛋白α（IκBα）mRNA表达。结果 与正常组比较,模型组血清中白细胞介素-6（IL-6）、白细胞介素-1β（IL-1β）和肿瘤坏死因子-α（TNF-α）含量升高（P<0.05）,胃黏膜组织NF-κB p65 mRNA表达升高（P<0.01）,IκBα mRNA表达降低（P<0.01）;与模型组比较,奥美拉唑组、配伍高、中剂量组、葛花组醉酒时间延长（P<0.05）,配伍高、中剂量组醒酒时间缩短（P<0.05）,配伍高剂量组血清中乙醇体积分数降低（P<0.05）,奥美拉唑组、配伍高、中剂量组胃黏膜中ADH活性升高（P<0.05）,配伍各剂量组、葛花组肉眼损伤评分降低（P<0.05）,奥美拉唑组、配伍各剂量组、葛花组病理损伤评分降低（P<0.01）,各给药组血清中IL-6表达降低（P<0.05）,奥美拉唑组、配伍各剂量组、枳椇子组血清中IL-1β表达降低（P<0.05）,配伍高、中剂量组血清中TNF-α表达降低（P<0.05）,各给药组胃黏膜组织NF-κB p65 mRNA表达降低（P<0.05）,奥美拉唑组、配伍各剂量组胃黏膜组织IκBα mRNA表达增加（P<0.05）;与高剂量组比较,配伍低剂量组与枳椇子组醉酒时间缩短（P<0.01）,葛花、枳椇子组醒酒时间延长（P<0.01）,配伍中、低剂量组、葛花组、枳椇子组血清中乙醇体积分数升高（P<0.05）,配伍中、低剂量组、枳椇子组肉眼损伤积分增加（P<0.05）,配伍中、低剂量组、葛花组、枳椇子组病理损伤积分增加（P<0.01）,配伍低剂量组、葛花组、枳椇子组血清中IL-1β含量升高（P<0.01）,葛花组与枳椇子组胃黏膜组织IκBα mRNA表达量降低（P<0.05）;与配伍中剂量组比较,枳椇子组醉酒时间缩短（P<0.05）,葛花组醒酒时间延长（P<0.05）,葛花组、枳椇子组病理损伤积分增加（P<0.01）,配伍低剂量组、葛花组、枳椇子组血清中IL-1β含量升高（P<0.05）;与配伍低剂量组比较,枳椇子组病理损伤积分增加（P<0.05）。结论 葛花、枳椇子及其配伍能起到对小鼠急性酒精性胃黏膜损伤的防治作用,可能与抑制胃黏膜NF-κB信号通路的表达有关,且配伍高剂量组药效最佳。     

电子鼻技术应用于白及及其近似饮片快速辨识的可行性分析

目的：探讨电子鼻技术应用于白及及其近似饮片快速辨识的可行性。方法：收集134批白及及其近似饮片（白及45批、天麻30批、玉竹30批、黄花白及29批）作为待测样品,使用PEN3型电子鼻采集样品嗅觉感官数据作为自变量X,基于2020年版《中华人民共和国药典》和地方标准的鉴别结果,以及各饮片高效液相色谱法（HPLC）指纹图谱和原始采购信息,获得辨识模型的标杆数据Y,分别采用主成分分析-判别分析（PCA-DA）、偏最小二乘法-判别分析（PLS-DA）、最小二乘法-支持向量机（LS-SVM）及K-最近邻（KNN）4种化学计量学方法建立45批白及与89批非白及的二分类辨识模型和上述4种饮片的四分类辨识模型Y=F(X)。结果：经留一法交互验证,在二分类辨识中,上述4种模型分类正判率分别为97.01%、97.01%、98.51%和97.01%;在四分类辨识中,这4种模型分类正判率分别为97.76%、89.55%、98.51%和97.01%。二分类和四分类辨识模型的最高正判率均可达到98.51%,且均以LS-SVM算法为最优,最优核函数分别选择径向基核函数和线性核函数。最优模型判别结果良好,没有未分类样...     

Correction to: Cichorium intybus L. promotes intestinal uric acid excretion by modulating ABCG2 in experimental hyperuricemia

The study of sex differences in hyperuricemia can provide not only a theoretical basis for this clinical phenomenon but also new therapeutic targets for urate-lowering therapy. In the current study, we aimed to confirm that estradiol can promote intestinal ATP binding cassette subfamily G member 2 (ABCG2) expression to increase urate excretion through the PI3K/Akt pathway. The estradiol levels of hyperuricemia/gout patients and healthy controls were compared, and a hyperuricemia mouse model was used to observe the urate-lowering effect of estradiol and the changes in ABCG2 expression in the kidney and intestine. In vivo and in vitro intestinal urate transport models were established to verify the urate transport function regulated by estradiol. The molecular pathway by which estradiol regulates ABCG2 expression in intestinal cells was explored. The estradiol level of hyperuricemia/gout patients was significantly lower than that of healthy controls. Administering estradiol benzoate (EB) to both male hyperuricemic mice and female mice after removing the ovaries confirmed the urate-lowering effect of estradiol, and hyperuricemia and estradiol upregulated the expression of intestinal ABCG2. Estradiol has been confirmed to promote urate transport by upregulating ABCG2 expression in intestinal urate excretion models in vivo and in vitro. Estradiol regulates the expression of intestinal ABCG2 through the PI3K/Akt pathway. Our study revealed that estradiol regulates intestinal ABCG2 through the PI3K/Akt pathway to promote urate excretion, thereby reducing serum urate levels.     

科技期刊出版运营需求调研与分析

【目的】 了解科技期刊从业人员和科研工作者对科技期刊出版技术、运营、传播的需求,探究可行的技术应用、工具开发和平台建设策略。【方法】 2020年11月,通过问卷星向科技期刊从业人员和科研工作者进行问卷调查;问卷涉及参与问卷调查人员对当今互联网技术发展、科技期刊运营模式、学术成果传播途径的了解和需求。【结果】 从402份面向科技期刊从业人员以及138份面向科研工作者的有效问卷中总结得出,参与问卷调查人员对互联网技术的应用、运营手段的丰富和传播途径的扩展有实际需求。【结论】 结合目前国际出版领域领先的出版技术与运营和传播实践,向科技期刊及相关公司机构提出技术应用、运营平台建设和传播体系搭建的相关可行性建议。     

肾衰透析患者拔牙的临床研究

目的 :探讨肾衰透析患者拔牙的安全性。　方法 :对 42例肾衰血透患者行 98次拔牙手术 ,共拔除患牙 12 2颗 ,术前采取全口洁治、服用抗生素、控制血压等措施 ,术后加强局部止血处理 ,预防出血、感染及心血管系统等并发症的发生。　结果 :透析组术后出血 44次 ,拔牙创口血块充盈不良或脱落 2 7次 ;对照组分别为 4和 5次 (94次手术 ,P<0 .0 5 )。拔牙创口定期观察 1个月 ,均愈合良好。　结论 :慢性肾衰患者通过透析 ,尿毒症得到控制和改善时 ,在作好围拔牙期处理的情况下 ,行拔牙手术是安全可行的     

放射治疗高能光子束吸收剂量不同测定规程的比较

目的 :介绍美国医学物理学家协会 (AAPM)最新颁布的高能光子束吸收剂量的测定规程。　方法 :以我院实际使用的剂量仪和电离室按照第 3代规程中推荐的方法测定医用直线加速器 6 MV高能光子束的吸收剂量。　结果 :新规程与第 1代规程比较的差异在 3%左右 ,与第 2代规程相比 ,差异 <1%。　结论 :新一代规程理论严谨 ,表达简明 ,具有更好的精度和最大程度上的应用方便性