奥卡西平及其中间体的新合成方法

介绍了一种新的合成奥卡西平(OCBZ)及其中间体的方法:以5H-二苯并[b,f]氮杂卓-5-甲酰氯为原料,通过加成溴化、氨解、水解得到OCBZ,总收率可达62左右,OCBZ的摩尔分数大于99.0。考察了影响氨解反应的因素,优化条件为n(NH3)/n(10,11-二溴-5H-二苯并[b,f]氮杂卓-5-甲酰氯)=5,反应温度约20℃,反应时间约35h,10-溴-5H-二苯并[b,f]氮杂卓-5-甲酰胺收率大于98,摩尔分数大于98.0。结果表明,温度高时氨解反应主要易生成副产物10,11-二溴-5H-二苯并[b,f]氮杂卓。主要产物及副产物的结构均用元素分析和MS进行了确证。该文报道工作的新颖性,已为浙江省科技信息研究院2008年1月8日出具的第200833B210143号《科技查新报告》所证实。该工作已进行1t/a规模的中试,结果为:平均收率约61,产品摩尔分数大于99.1。     

Influence of Different Salts on the G-Quadruplex Structure Formed from the Reversed Human Telomeric DNA Sequence

G-rich telomeric DNA plays a major role in the stabilization of chromosomes and can fold into a plethora of different G-quadruplex structures in the presence of mono- and divalent cations. The reversed human telomeric DNA sequence (5′-(GGG ATT)₄; RevHumTel) was previously shown to have interesting properties that can be exploited for chemical sensing and as a chemical switch in DNA nanotechnology. Here, we analyze the specific G-quadruplex structures formed by RevHumTel in the presence of K⁺, Na⁺, Mg²⁺ and Ca²⁺ cations using circular dichroism spectroscopy (CDS) and F�f6;rster resonance energy transfer (FRET) based on fluorescence lifetimes. CDS is able to reveal strand and loop orientations, whereas FRET gives information about the distances between the 5′-end and the 3′-end, and also, the number of G-quadruplex species formed. Based on this combined information we derived specific G-quadruplex structures formed from RevHumTel, i.e., a chair-type and a hybrid-type G-quadruplex structure formed in presence of K⁺, whereas Na⁺ induces the formation of up to three different G-quadruplexes (a basket-type, a propeller-type and a hybrid-type structure). In the presence of Mg²⁺ and Ca²⁺ two different parallel G-quadruplexes are formed (one of which is a propeller-type structure). This study will support the fundamental understanding of the G-quadruplex formation in different environments and a rational design of G-quadruplex-based applications in sensing and nanotechnology.     

Alternate-Day Fasting Ameliorates Newly Established Sjögren’s Syndrome-like Sialadenitis in Non-Obese Diabetic Mice

Intermittent fasting confers protections to various diseases including autoimmune disorders, but the specific effects of intermittent fasting on Sj�f6;gren’s syndrome (SS) remains inconclusive. The present study was undertaken to determine the specific impact of alternate-day fasting (ADF) on newly established SS-like sialadenitis using non-obese diabetic (NOD) mice. Female NOD mice were deprived of food every other day from 10 to 13 weeks of age, the early stage of established SS, and then analyzed for the disease characteristics. Mice in the ADF group had higher salivary flow rate and attenuated submandibular gland (SMG) inflammation, compared to the control mice fed with standard chow ad libitum. The improvements were accompanied with a decrease in the total leukocytes, T and B lymphocytes and activated CD4 and CD8 T cells, and a down-regulation of pro-inflammatory cytokines IFN-γ and IL-17, chemokine receptor CXCR3 and its ligands CXCL9 and CXCL11 in the SMGs. ADF also led to elevated mRNA levels of water channel protein aquaporin 5 and tight junction protein claudin-1, two factors crucial for normal salivary secretion in the SMGs. In addition, ADF reduced the proportion of IFN-γ- and IL-17- expressing CD4 T cells and diminished mRNA levels of IFN-γ, TNF-α, and IL-17 in the total submandibular draining lymph node cells. Taken together, ADF is effective in ameliorating newly established SS-associated salivary gland exocrinopathy in NOD mice.     

变频器的控制方式及选型应用

对变频器的常用控制方式进行了比较,分析了各种控制方式的优缺点,为工程技术人员更好选择与使用变频器提供了借鉴和参考。     

素混凝土桩复合地基沉降计算及有限元分析

有限元法计算地基沉降量虽较规范法准确,但较为复杂,因此将规范法和有限元法计算得到的地基沉降量数值进行比较,得出一个地基沉降量修正系数,该修正系数在同一地区内对设计工作有很大的参考价值.     

纳米Si/SiNx薄膜的制备及对Nd:YAG激光器的被动调Q

为了研究纳米硅镶嵌氮化硅(nanoscale-Si-particle embedded in silicon nitride thin films,简称nc-Si/SiNX)薄膜材料的被动调Q特性,采用射频磁控反应溅射法结合热退火处理在单晶硅衬底上制备该薄膜。用该样品作为可饱和吸收体,在凹—平腔中实现了氙灯抽运Nd:YAG激光器的被动调Q运转,在抽运重复频率1Hz情况下获得脉宽最小可达19ns的调Q单脉冲输出。并且研究了该薄膜结构特性、激光器参数,如：抽运电压、腔长对调Q脉冲输出性能产生的影响。在此基础上,对实验现象产生的原因做了分析讨论。结果表明,nc-Si/SiNX薄膜有一定的调Q效果,具有潜在的研究及应用价值。     

光学4f系统灰度误差补偿的实现

为补偿光学4f系统灰度误差,提出基于直方图匹配和径向基函数(RBF)神经网络的灰度误差补偿方法。首先利用径向基函数神经网络拟合经光学4f系统输出图像的直方图与对应输入图像的直方图之间的非线性变换,得到输出图像与输入图像的直方图匹配变换曲线的最优估计;再依据直方图匹配曲线的最优估计对经光学4f系统的输出图像进行直方图匹配,得到灰度误差补偿后的图像。利用实际的光学4f系统进行光学实验,灰度误差补偿后图像的信噪比平均提高了2.96dB,视觉效果明显改善。实验结果表明,该方法能有效补偿光学4f系统灰度误差,提高基于光学4f系统的光学信息处理的精度。     

基于TDLAS-WMS的近红外痕量CH_4气体传感器

为了对煤矿CH4气体进行实时监测,基于混合可调谐二极管激光吸收光谱(TDLAS)与波长调制光谱(WMS)的检测技术,采用中心波长为1.65μm的分布反馈(DFB)激光器,设计并研制出痕量CH4气体传感器。利用自主设计的DFB激光器温度控制器,通过调节激光器工作温度,进而使其发光光谱扫描CH4气体的吸收跃迁谱线。同时利用WMS检测技术将待测信号频率移至高频区,减小1/f噪声。利用该痕量CH4气体传感器,在被测气体体积分数为(0~106)×10-6的范围内,对二次谐波信号进行了提取。测试结果显示:在(0~106)×10-6范围内相对测量误差小于7%,检测下限为11×10-6。同时,研究人员可以通过更换其他波长的激光器,实现对其他气体的检测。     

Imbalance in Bone Morphogenic Proteins 2 and 7 Is Associated with Renal and Cardiovascular Damage in Chronic Kidney Disease

Arterial stiffness is a major vascular complication of chronic kidney disease (CKD). The development of renal damage, hypertension, and increased pulse wave velocity (PWV) in CKD might be associated with an imbalance in bone morphogenetic proteins (BMP)-2 and BMP-7. Plasma BMP-2 and BMP-7 were determined by ELISA in CKD patients (stages I–III; n = 95) and Munich Wistar Fr�f6;mter (MWF) rats. Age-matched Wistar rats were used as a control. The expression of BMP-2, BMP-7, and profibrotic and calcification factors was determined in kidney and perivascular adipose tissues (PVAT). BMP-2 was higher in stage III CKD patients compared to control subjects. BMP-7 was lower at any CKD stage compared to controls, with a significant further reduction in stage III patients. A similar imbalance was observed in MWF rats together with the increase in systolic (SBP) and diastolic blood pressure (DBP), or pulse wave velocity (PWV). MWF exhibited elevated urinary albumin excretion (UAE) and renal expression of BMP-2 or kidney damage markers, Kim-1 and Ngal, whereas renal BMP-7 was significantly lower than in Wistar rats. SBP, DBP, PWV, UAE, and plasma creatinine positively correlated with the plasma BMP-2/BMP-7 ratio. Periaortic and mesenteric PVAT from MWF rats showed an increased expression of BMP-2 and profibrotic and calcification markers compared to Wistar rats, together with a reduced BMP-7 expression. BMP-2 and BMP-7 imbalance in plasma, kidney, and PVATs is associated with vascular damage, suggesting a profibrotic/pro-calcifying propensity associated with progressive CKD. Thus, their combined analysis stratified by CKD stages might be of clinical interest to provide information about the degree of renal and vascular damage in CKD.