Composite microparticles of ibuprofen/lipid generated by supercritical fluids from their melts

采用CO2及N2辅助的气体饱和溶液微粒形成技术制备布洛芬/肉豆蔻酸、布洛芬/三棕榈酸甘油酯复合微粒,考察它们的形态、颗粒分布以及复合微粒中药物的溶出情况。N2辅助过程制得的布洛芬(质量分数5%)/肉豆蔻酸复合微粒与用该过程得到的纯肉豆蔻酸大小及粒径分布大致相同,而CO2辅助过程制得的布洛芬/肉豆蔻酸复合微粒却要比该过程得到的纯肉豆蔻酸的粒径要大,分布也较宽;CO2及N2辅助形成的布洛芬/肉豆蔻酸复合微粒无缓释效果。用N2辅助制备得到的含20%布洛芬(质量分数)的复合微粒保持了三棕榈酸甘油酯微粒化后的颗粒形貌,粒径更大;用CO2辅助制备得到的含20%布洛芬的复合微粒其粒径比三棕榈酸甘油酯微粒化后的颗粒粒径要小,粒径分布更窄;布洛芬/三棕榈酸甘油酯复合微粒具有缓释效果,而且用N2辅助制备的布洛芬含量为5%的复合微粒比布洛芬含量为20%的复合微粒溶出慢。Using the CO2-assisted and N2-assisted atomization processes,ibuprofen/lipid composite microparticles can be produced;the lipid includes myristic acid(MA) and tripalmitin(TP).The ibuprofen(5% in mass ratie)/MA composite microparticles show similar particle sizes to that of pure MA from the N2-assisted process,while the composite microparticles have a large particle size and particle size distribution,compared to that of pure MA from the CO2-assisted process.The dissolution reveals no controlled release of ibuprofen for the ibuprofen/MA composite microparticles either from the N2-assisted process or from the CO2-assisted process.For the ibuprofen/TP system,the obtained composite microparticles containing 20%(in mass) ibuprofen show similar particle morphology,while has a larger particle size(PS) than that of the pure myristic acid particles in the case of N2-assisted process.Nevertheless,the microparticles from the CO2-assisted process has a small PS and narrow PSD,compared to that of the pure myristic acid particles.The obtained ibuprofen/TP composite microparticles containing 5% or 20% ibuprofen show an evidently controlled drug release.For example,the drug release is only 20% in 500 min for the ibuprofen/TP microparticles containing 20% ibuprofen,prepared by the CO2-assisted process.国家自然科学基金资助项目(20406015);; 福建省新世纪优秀人才支持计划;; 福建省自然科学基金资助项目(2007J0167

Modeling of ammonothermal growth processes of GaN crystal in large-size pressure systems

Gallium nitride (GaN) is a wide-bandgap semiconductor material with a wide array of applications in optoelectronics and electronics. Modeling of the fluid flow and thermal fields is discussed, and simulations of velocity and volumetric-flow-rate profiles in different pressure systems are shown. The nutrient is considered as a porous media bed, and the flow is simulated using the Darcy-Brinkman-Forchheimer model. The resulting governing equations are solved using the finite-volume method. We analyzed the heat and mass transfer behaviors in autoclaves with diameters of 2.22, 4.44, and 10 cm. The effects of baffle design on flow pattern, and heat and mass transfer in different autoclaves are analyzed. For the research-grade autoclave with diameter of 2.22 cm, the constraint for the GaN growth is found to be the growth kinetics and the total area of seed surfaces in the case of baffle opening of 10%. For large-size pressure systems, the concentration profiles change dramatically due to stronger convection at higher Grashof numbers. The volumetric flow rates of the solvent across the baffles are calculated. Since ammonothermal growth experiments are expensive and time consuming, modeling becomes an effective tool for research and optimization of ammonothermal growth processes

沿海产盐区与非产盐区18～45岁人群碘营养状况及甲状腺功能水平研究

目的掌握厦门市沿海产盐区与非产盐区居民盐碘、18～45岁人群碘营养和甲状腺功能水平状况,为采取针对性的防治措施提供依据。方法选择沿海产盐区翔安区和非产盐区集美区为调查点,调查居民合格碘盐食用率、18～45岁育龄期妇女和男性尿碘水平、甲状腺激素水平和海带、紫菜的摄入习惯。结果产盐区和非产盐区盐碘中位数均为27.21 mg/kg,合格碘盐食用率分别为95.33%和96.33%;18～45岁男性尿碘中位数分别为206.55μg/L和232.95μg/L,尿碘<100μg/L的比例分别为20.97%和10%;18～45岁育龄期妇女尿碘中位数分别为176.95μg/L和227.70μg/L,尿碘<100μg/L的比例分别为21.67%和25%;产盐区和非产盐区18～45岁男性和育龄期妇女的甲状腺激素TSH、Tg、FT3、FT4、TPOAb、TT3、TT4中位数均在正常值范围内;产盐区18～45岁男性的甲状腺功能亢进阳性率为3.4%、育龄期妇女的甲状腺功能减退和亚临床甲状腺减退症的阳性率均为1.67%,而非产盐区均为0。产盐区和非产盐区18～45岁男性和育龄期妇女中均有一定比例易患甲状腺免疫性疾病的人群。每月食用海带、紫菜的次数≥4次、1～3次和<1次的人尿碘组间比较无统计学差异。结论产盐区和非产盐区18～45岁男性和育龄期妇女碘营养总体处于适宜状态,应坚持食盐加碘措施,对育龄期妇女在婚前体检时开展常规碘营养水平和甲状腺功能检测

NUMERICAL SIMULATION IN AMMONOTHERMAL GROWTH OF SINGLE CRYSTALS OF GaN

氮化镓晶体是继单晶硅之后的一种新型的半导体材料. 本文利用有限体积法模拟了氨热法生长氮化镓晶体中流场的瞬态特性, 研究了隔板开孔10％时流场结构、温度场、浓度场. 发现对于隔板开孔率(10％)的情形, 中心开孔及边缘间隙的平均速度表现为振荡的特性, 中心开孔速度大多是正的, 边缘开孔大多是负的. 大的温度梯度发生在在高压釜壁面与液体的交界处与隔板周围. 物质由多孔介质区向生长区输

氨热法生长氮化镓晶体的数值模拟

氮化镓晶体是继单晶硅之后的一种新型的半导体材料。本文利用有限体积法模拟了氨热法生长氮化镓晶体中流场的瞬态特性,研究了隔板开孔10%时流场结构、温度场、浓度场。发现对于隔板开孔率（10%）的情形,中心开孔及边缘间隙的平均速度表现为振荡的特性,中心开孔速度大多是正的,边缘开孔大多是负的。大的温度梯度发生在在高压釜壁面与液体的交界处与隔板周围。物质由多孔介质区向生长区输运

Instabilities of surface tension driven flows between counter-rotating disks

Instabilities of surface tension driven flows between counter-rotating disks were investigated by using the linear stability analysis method.The basic flow equations are solved by a numerical scheme based on a pseudo-spectral Chebyshev method.The perturbation equations are solved based on a discr..

Neural basis for successful encoding and retrieval of prospective memory

前瞻记忆是指对将来行为和事件的记忆,而相继记忆效应(Dm效应)是指根据记忆提取阶段的成绩,分析与之对应的编码阶段的项目和忘的项目之间的神经活动的差异.本研究采用任务转化范式,借助ERP仪器,使用汉字材料,探讨了前瞻记忆的Dm效应.研究发现,100～200ms(P150),250～280ms(fbN2),400～700ms(LPC)随后前瞻记忆击中的ERPs比随后前瞻记忆忘的ERPs更正.其中,早期的相继记忆效应(P150更正)可能反映了前瞻记忆将来意向的加工或者准备意的加工;而后两个时段与以往的研究结果一致,fbN2可能与汉语材料的加工有关,LPC则反映了记忆的精确编码.总之,本研究从ERP的角度提供了前瞻记忆编码与以往情景记忆编码有相同之处(LPC更正),又存在一些差异(P150更正)的证据,但这种差异需要进一步的研究来论证

A New Method for Wet Passivating of Porous Silicon

采用硫代乙酰胺的HF酸水溶液作为氧化剂对初始多孔硅进行钝化处理,改善了多孔硅表面结构并提高了发光强度.同时研究了钝化电流,钝化温度和钝化时间等一系列因素对钝化多孔硅光致发光强度的影响.实验发现,在60℃恒温下,对样品通电流1mA/cm2,进行10min的钝化处理可以获得最强的光致发光,发光强度比初始样品发光强度增强了一个数量级.另外,通过傅立叶红外吸收谱(FTIR)以及X射线光电子能谱(XPS)测试分析,探讨了钝化处理使得多孔硅发光强度提高的原因.国家自然基金项目(60336010)资

一种籽晶温度梯度方法生长碳化硅单晶的装置

本发明公开一种籽晶温度梯度方法生长碳化硅单晶的装置，包括感应加热装置、真空腔和晶体生长单元，所述感应加热装置包括感应线圈以及为所述感应线圈供电的中频电源，所述感应线圈位于所述真空腔的外部；所述晶体生长单元包括位于真空腔内的石墨感应器、保温材料、石墨坩埚和籽晶托；所述保温材料位于所述石墨感应器的外部；所述石墨坩埚位于所述石墨感应器的内部，所述籽晶托位于所述石墨坩埚的顶部。本发明的装置能够大大降低生产碳化硅单晶所需要的功率，还能避免感应线圈放置在真空室内可能产生真空放电、冷却水通道漏水、石墨粉末污染铜管等问题，具有较高的实用价值

自发性脑出血患者视神经鞘直径与颅内压相关性研究 Association between Optic Nerve Sheath Diameter and Intracranial Pressure in Patients with Spontaneous Intracerebral Hemorrhage

目的 探究自发性脑出血（spontaneous intracerebral hemorrhage，sICH）患者视神经鞘直径（optic nerve sheath diameter，ONSD）与颅内压（intracranial pressure，ICP）的相关性，评估ONSD对ICP升高的诊断效能。 方法 连续纳入2021年12月—2022年5月在首都医科大学附属北京天坛医院急诊科住院治疗并接受有创ICP监测的sICH患者。在入抢救室0 h、4 h、8 h、12 h、24 h、48 h分别通过床旁超声测量ONSD并记录同时刻ICP数值。采用Spearman相关分析评估ONSD与ICP关系。采用ROC曲线评估ONSD对ICP＞20 mmHg（1 mmHg=0.133 kPa）的诊断效能。 结果 共纳入12例患者，年龄59（42～76）岁，共计采集72对ONSD和ICP数据。ONSD与ICP间相关系数为0.768（95%CI 0.578～0.886，P＜0.001）。应用ONSD诊断ICP＞20 mmHg的ROC曲线下面积为0.841（95%CI 0.727～0.921，P=0.007）。以ONSD≥5.35 mm为阈值诊断ICP＞20 mmHg的灵敏度为0.947，特异度为0.796，阳性预测值为0.667，阴性预测值为0.972。 结论 在sICH患者中，超声测量的ONSD与ICP呈正相关，ONSD≥5.35 mm可以诊断ICP增高。 Abstract: Objective To investigate the association between optic nerve sheath diameter (ONSD) and intracranial pressure (ICP) in patients with spontaneous intracerebral hemorrhage (sICH), and to evaluate the performance of ONSD in diagnosis ICP elevation. Methods Patients with sICH admitted to the emergency department of Beijing Tiantan Hospital, Capital Medical University from December 2021 to May 2022 and receiving invasive ICP monitoring were consecutively included. ONSD was measured by bedside ultrasound and ICP was recorded at 0 h, 4 h, 8 h, 12 h, 24 h, 48 h after admission. Spearman correlation analysis was used to evaluate the relationship between ONSD and ICP. ROC was used to evaluate the diagnostic efficacy of ONSD in the diagnosis of ICP >20 mmHg. Results A total of 12 patients, aged 59(42-76) years were enrolled, of which a total of 72 pairs of ONSD and ICP data were collected. Spearman rank correlation coefficient of ONSD and ICP was 0.768 (95%CI 0.578-0.886, P20 mmHg was 0.841 (95%CI 0.727-0.921, P=0.007). Using ONSD 5.35 mm as the threshold for diagnosing ICP>20 mmHg, its sensitivity was 0.947, specificity was 0.796, positive predictive value was 0.667, and negative predictive value was 0.972. Conclusions In patients with sICH, Ultrasound measurement of ONSD is positively correlated with ICP, and increased ICP can be diagnosed when ONSD≥5.35 mm