Photoinduced transformations of stiff-stilbene-based discrete metallacycles to metallosupramolecular polymers

Control over structural transformations in supramolecular entities by external stimuli is critical for the development of adaptable and functional soft materials. Herein, we have designed and synthesized a dipyridyl donor containing a central Z-configured stiff-stilbene unit that self-assembles in the presence of two 180° di-Pt(II) acceptors to produce size-controllable discrete organoplatinum(II) metallacycles with high efficiency by means of the directional-bonding approach. These discrete metallacycles undergo transformation into extended metallosupramolecular polymers upon the conformational switching of the dipyridyl ligand from Z-configured (0°) to E-configured (180°) when photoirradiated. This transformation is accompanied by interesting morphological changes at nanoscopic length scales. The discrete metallacycles aggregate to spherical nanoparticles that evolve into long nanofibers upon polymer formation. These fibers can be reversibly converted to cyclic oligomers by changing the wavelength of irradiation, which reintroduces Z-configured building blocks owing to the reversible nature of stiff-stilbene photoisomerization. The design strategy defined here represents a novel self-assembly pathway to deliver advanced supramolecular assemblies by means of photocontrol.Natural systems provide many examples of self-assembled biosupramolecules that respond to external stimuli through conformational changes that ultimately play a role in carrying out their various biological functions. Mimicking this stimuli-responsive behavior in artificial systems is a promising route toward obtaining sophisticated molecular-based architectures with functional and structural tunability (1–3). Using the absorption of photons as a trigger is particularly attractive in that light-induced transformations maintain high spatial and temporal resolution without producing waste products even during multiple reversible switching sequences (4). In materials science, one of the most appealing characteristics of photochromic molecules is the direct conversion of light into mechanical energy based on their photo-reversible structural transformations (5). Among such chromophores, a stiff-stilbene moiety (1,1′-biindane) is useful owing to its unique characteristics (6). First, stiff stilbene can adopt either a cis or trans configuration with respect to its central double bond. Second, the high activation barrier between the two isomers (∼43 kcal⋅mol⁻¹, corresponding to a half-life of ∼10⁹ y at 300 K) makes thermal E/Z isomerization negligible at temperatures of 420 K and lower. Third, the quantum yield for the photoisomerization of either isomer is high (50%). Fourth, the stiff-stilbene core is readily substituted using well-established synthetic methods. Owing to these promising characteristics, Boulatov and coworkers (7) constructed a molecular force probe by integrating the moiety into a stretched polymer to mimic the strain generated in diverse functional groups. Yang and coworkers (8) reported hydrogen-bonded supramolecular polymers and studied their polymerization mechanisms and physical properties based on the photoisomerization of the stiff-stilbene units. Nevertheless, stiff-stilbene-based supramolecular entities are underexplored despite exhibiting properties that make the functionality potentially useful in the construction of photoresponsive supramolecular materials.Coordination-driven self-assembly is a powerful method of constructing supramolecular coordination complexes (SCCs) by the spontaneous formation of metal–ligand bonds that draws inspiration from the design principles of natural systems (9–20). This approach organizes metal acceptors and organic donors to prepare well-defined cavity-cored 2D metallacycles and 3D metallacages, which can be functionalized on their interior or exterior vertices for applications in host–guest chemistry (21, 22), catalysis (23), molecular flasks (24), bioengineering (25), amphiphilic self-assembly (26), and so on. The versatility of coordination-driven self-assembly can be enhanced by designs that allow for post-self-assembly modifications that in some cases result in complete structural transformations. For example, the Stang group previously demonstrated the transformation of self-assembled polygons by changing the angle between the bonding sites of a ligand from 180° to 120° upon treatment of Co₂(CO)₆ with an acetylene moiety (27). Yang and coworkers (28) reported the construction of multibisthienylethene hexagons capable of reversible supramolecule-to-supramolecule conversions induced by ring-open and ring-closed conformational changes of the bisthienylethene units. Herein we expand upon the transformations established by the systems described above designing SCCs capable of evolving from discrete metallacycles into infinite constructs using external stimuli.Supramolecular polymers can be defined as dynamically reversible polymeric arrays (29–37) that form from the explicit manipulation of noncovalent forces between monomeric units (38–43). Supramolecular polymer chemistry can readily complement coordination-driven self-assembly, as exemplified by our efforts to design hierarchical supramolecular polymerizations of discrete organoplatinum(II) metallacycles, thus accessing novel supramolecular polymeric materials, such as macroscopic hexagonal supramolecular polymer fibers (44), dendronized organoplatinum(II) metallacyclic polymers (45), and a responsive, cavity-cored supramolecular polymer network metallogel (46). Herein, we report photoresponsive supramolecular transformations between discrete organoplatinum(II) metallacycles and infinite metallosupramolecular polymers induced by a cis/trans conformational transition of a stiff-stilbene-based dipyridyl ligand. The self-assembly behaviors, physical properties, topologies, and morphologies of these SCCs can be regulated by photoisomerization, demonstrating this powerful approach to prepare advanced supramolecular coordination complexes.     

斑点免疫金银染色诊断华支睾吸虫病的应用研究

用斑点免疫金银染色(Dot-IGSS)检测35例华支睾吸虫病人血清抗体,阳性率为100％,血清平均效价为1:1656,35份正常对照血清全部阴性。在一中学进行的流行病学调查中,血清抗体阳性率为16.99％(142/836)。抗体阳性者粪便虫卵检出率为76.09％(105/138)。抗体反应强度为1+、2+3+、4+的粪便虫卵检出率分别为57.14％(28/49)、75.68％(28/37)、94.74％(36/38)和92.86％(13/14)。该法敏感、简便、实用。     

2009-2010年江苏省徐州市儿童手足口病病原学检测分析

目的 了解江苏省徐州地区2009-2010年儿童手足口病流行的病原学特征。 方法 2009年3-8月和2010年1-12月共采集徐州儿童医院门诊、住院及常规监测的511例疑似手足口病(HFMD)儿童患者的咽拭、肛拭标本,提取病毒RNA,用实时荧光定量PCR(real-time PCR)方法同时进行肠道病毒(EV),肠道病毒71型(EV71)和柯萨奇病毒A16(Cox A16)的特异性基因检测。 结果 511例疑似手足口病患儿的标本中,总肠道病毒阳性288例,占56.36％; 288个肠道病毒核酸阳性病例中,EV71核酸阳性202例,Cox A16核酸阳性55例,构成比分别为70.14%和19.10%。5岁儿童感染的肠道病毒有EV71型、Cox A16型及非EV71非Cox A16的其他肠道病毒感染,5岁儿童则只有EV71感染病例。 结论 2009-2010年徐州地区儿童手足口病患儿以1~3岁儿童为主,其主要病原是肠道病毒EV71型,其次是Cox A16型。     

空腹血糖、糖化血红蛋白与2型糖尿病肾功能的关系探讨

目的探讨空腹血糖（FPG）、糖化血红蛋白（HbA1c）与2型糖尿病（DM）肾功能的关系。方法选269例2型DM患者分别以FPG、HbA1c进行分组,分析比较FPG、HbA1c与其血清肾功能即尿素（Urea）、肌酐（Cr）、尿酸（UA）关系。按FPG（mmol/L）分组：6.111.1（C组）;按HbA1c（%）分组：HbA1c≤6.5（A1组）,6.57.6（C1组）。另选健康体检者60例为正常对照组。结果与对照组相比,B、C两患者组Urea和Cr差异均有统计学意义（P〈0.01）,而A组差异无统计学意义（P〉0.05）;与A组相比,C组的Urea和Cr差异有统计学意义（P〈0.01）。与A1组相比,B1、C1两组的Urea和Cr差异均有统计学意义（P〈0.01）;与B1组比,C1组差异无统计学意义（P〉0.05）。UA差异均无统计学意义（P〉0.05）。Urea和Cr与FPG均有显著相关（r=0.302,P〈0.01;r=0.309,P〈0.01）;Urea和Cr与HbA1c也均有显著相关（r=0.236,P〈0.01;r=0.181,P〈0.01）;UA与FPG、HbA1c均无显著相关（r=-0.062,P〉0.05;r=-0.044,P〉0.05）。结论 DM患者Urea和Cr随着FPG和HbA1c升高有不同程度的升高。高FPG和高HbA1c是DM肾功能损伤的危险因素之一,进行FPG和HbA1c联合检测有助于筛查和预防糖尿病肾病。     

血液灌流频次与有机磷中毒疗效分析

目的探讨血液灌流（HP）治疗频次与急性重度有机磷农药中毒（ASOP）疗效关系。方法选择符合诊断标准的患者,按治疗情况不同分两组。中毒后48 h内行血液灌流治疗3～4次的20例为治疗组。48 h内行一次血液灌流治疗的16例为对照组。通过观察两组阿托品用量、昏迷患者神智转清醒时间、胆碱酯酶（CHE）恢复正常时间、中间综合症（IMS）发生率、抢救成功率等指标判断疗效。结果两组比较,治疗组阿托品用量少,昏迷患者清醒时间短,治愈率明显提高,胆碱酯酶恢复正常时间短,IMS发生率低,抢救成功率高。结论早期多次血液灌流治疗能清除体内有机磷农药,配合常规治疗对救治急性重度有机磷农药中毒疗效显著。     

HPLC法同时测定复方阿托伐他汀钙分散片中2组分含量

目的:建立同时测定复方阿托伐他汀钙分散片中氨氯地平、阿托伐他汀含量的方法。方法:采用高效液相色谱法。色谱柱为Waters XTerra RP18;流动相为乙腈-0.03moL·L-1磷酸二氢钾溶液=58:42,流速为1.0mL·min-1;检测波长为240nm;柱温为30℃。结果:氨氯地平、阿托伐他汀检测浓度线性范围分别为3.86～61.83(r=0.9999,n=5)、9.28～148.56(r=0.9999,n=5)μg·mL-1;平均回收率分别为100.7%(RSD=0.94%,n=6)、100.6%(RSD=0.85%,n=6)。结论:所建立的方法简便、灵敏、准确,可用于复方阿托伐他汀钙分散片的含量测定。     

1989-2010年徐州市区儿童青少年伤害死亡状况分析

目的分析1989-2010年徐州市区0岁～19岁儿童青少年的伤害死亡状况,为制定伤害干预措施提供依据。方法收集1989-2010年徐州市儿童青少年伤害死亡资料,进行统计分析。结果徐州市区0岁～19岁儿童青少年伤害的平均死亡率为13.09/105,男性高于女性(P=0.000)。前5位死亡原因依次为机动车交通事故、淹死、非机动车运输事故、自杀和意外中毒。伤害死亡率随年份的增长总体呈下降趋势。潜在寿命损失年(YPLL)为53981年,YPLL标化率为8.27‰。结论伤害死亡率虽呈逐年下降趋势,但仍是1岁～19岁组儿童的首位死因,应加强对儿童伤害死亡的预防,减少伤害的发生。     

BIPAP呼吸机治疗慢性阻塞性肺疾病合并Ⅱ型呼吸衰竭42例疗效分析

目的观察使用BIPAP呼吸机在慢性阻塞性肺病合并Ⅱ型呼吸衰竭的治疗中的临床疗效。方法在2006年1月—2011年1月间在徐州医学院附属第三医院接受治疗的86例慢性阻塞性肺病合并Ⅱ型呼吸衰竭患者,随机分为治疗组42例和对照组44例,对照组常规治疗中加用呼吸兴奋剂,治疗组常规治疗加用BIPAP呼吸机进行辅助通气治疗,监测患者治疗前、后4d的动脉血气并进行比较分析。结果治疗组患者治疗后PaO2、SpO2均明显升高,PaCO2明显降低,有统计学意义(P<0.05),而对照组也较治疗前改善,但PaO2、PaCO2无统计学意义(P>0.05),SpO2升高显著(P<0.05)。治疗4d后治疗组患者PaO2的升高程度及PaCO2的下降程度均明显优于对照组(P<0.05)但SpO2无明显差异(P>0.05)。治疗组患者治疗后嗜睡,神志模糊较前明显好转,均恢复意识,对照组患者治疗后仍有部分意识障碍,两组比较有差异(P﹤0.05)。结论 BIPAP呼吸机治疗慢性阻塞性肺炎合并Ⅱ型呼吸衰竭患者疗效较常规药物显著。     

斑点免疫金银染色法诊断囊虫病的研究

用斑点免疫金银染色法(Dot-IGSS)和Dot-ELISA检测40份确诊为囊虫病患者的血清。两种方法检测的阳性率均为100％,用Dot-IGSS检测,40份血清的平均滴度为1:27470,显著高于用Dot-ELISA检测的平均滴度1:9069(P<0.01)。检测50份义务献血员血清,假阳性率分别为2％和4％。10份日本血吸虫病人血清分别有1份和2份出现假阳性。与肝吸虫病人血清无交叉反应,与包虫病人血清有明显的交叉反应。     

急性心肌梗死后T波极性变化与左心功能的关系

目的探讨Q波性心肌梗死从急性期到慢性期心肌损害、心功能与T波方向变化的关系.方法选择急性前壁心肌梗死病人93例,持续T波倒置组44例,T波直立组49例,按T波恢复直立的时间不同又分4个亚组:＜3月组6例;(3～6)月组16例;(6～12)月组23例;持续直立组4例.测量各组的左室射血分数、舒张末径、室壁运动记分等超声心动图指标.结果除持续T波直立亚组外,其他T波直立亚组的左室射血分数高于T波倒置组,左室舒张末径、室壁运动记分低于T波倒置组.结论早期T波由倒置变为直立的病人,左心功能改善显著;有Q波的导联倒置T波正常化的早晚可以用来评估左心功能.