血清UA、sdLDL、sST2对急性心肌梗死患者PCI术后无复流的预测价值分析

摘要 目的：探讨血清尿酸（UA）、小而密低密度脂蛋白（sdLDL）、可溶性致癌抑制因子2（sST2）对急性心肌梗死（AMI）患者经皮冠状动脉介入治疗（PCI）术后无复流（NRF）的预测价值。方法：选取2021年1月～2023年1月睢宁县人民医院收治的196例AMI患者为AMI组，根据PCI术后是否发生NRF分为NRF组和血流正常组，另选取同期120名体检健康志愿者为对照组。比较AMI组与对照组血清UA、sdLDL、sST2水平。采用多因素Logistic回归分析AMI患者PCI术后NRF的影响因素，采用受试者工作特征（ROC）曲线分析血清UA、sdLDL、sST2水平对AMI患者PCI术后NRF的预测价值。结果：与对照组比较，AMI组血清UA、sdLDL、sST2水平升高（P＜0.05）。196例AMI患者PCI术后NRF发生率为34.69%，NRF组年龄大于血流正常组，糖尿病比例、肌酸激酶同工酶（CK-MB）、肌钙蛋白I（cTnI）、低密度脂蛋白胆固醇（LDL-C）、UA、sdLDL、sST2水平高于血流正常组（P＜0.05）。多因素Logistic回归分析显示，年龄增加和UA、sdLDL、sST2升高为AMI患者PCI术后NRF的独立危险因素（P＜0.05）。ROC曲线分析显示，血清UA、sdLDL、sST2水平单独和联合预测AMI患者PCI术后NRF的曲线下面积AUC(0.95CI)分别为0.707(0.481～0.934)、0.742(0.513～0.955)、0.737(0.480～0.970)、0.863(0.737～0.960)，联合预测大于单独预测指标。结论：血清UA、sdLDL、sST2水平升高为AMI患者PCI术后NRF的独立危险因素，血清UA、sdLDL、sST2水平联合预测AMI患者PCI术后NRF的价值较高。     

术前血清Lp-PLA2、sST2水平与急性冠状动脉综合征患者PCI术后冠状动脉慢血流/无复流的关系研究

摘要 目的：探讨急性冠状动脉综合征（ACS）患者术前血清脂蛋白相关磷脂酶A2（Lp-PLA2）、可溶性生长刺激表达基因2蛋白（sST2）表达情况,分析术前血清Lp-PLA2、sST2与经皮冠脉介入术（PCI）术后冠状动脉慢血流/无复流（CSF/CNF）的关系。方法：选择2019年9月至2022年9月在徐州医科大学附属连云港医院心内科进行PCI治疗的ACS患者386例为ACS组,根据术后心肌梗死溶栓实验（TIMI）血流分级分为CSF/CNF组（138例）和正常血流组（248例）;另选择同期在本院体检的健康对象174例为健康对照组。采用酶联免疫吸附法（ELISA）检测ACS患者术前及健康志愿者体检时血清Lp-PLA2、sST2水平,比较ACS组与健康对照组血清Lp-PLA2、sST2水平。采用单因素及多因素logistic回归模型分析CSF/CNF的影响因素,采用受试者工作特征（ROC）曲线分析术前血清Lp-PLA2、sST2对ACS患者PCI术后CSF/CNF的预测价值。结果：术前血清Lp-PLA2、sST2水平ACS组高于健康对照组（P＜0.05）;单因素分析结果显示,CSF/CNF组术前血肌酐（Scr）、超敏C反应蛋白（hs-CRP）、D-二聚体（D-D）、Lp-PLA2、sST2水平均高于正常血流组（P＜0.05）;多因素logistic回归模型分析结果显示,术前血清Lp-PLA2、sST2水平升高是ACS患者PCI术后发生CSF/CNF的独立危险因素（P＜0.05）。ROC曲线分析结果显示,两指标联合预测ACS患者PCI术后CSF/CNF的曲线下面积（AUC）显著高于术前血清Lp-PLA2、sST2单独检测。结论：PCI术后发生CSF/CNF的ACS患者术前血清Lp-PLA2、sST2水平异常升高,术前检测血清Lp-PLA2、sST2能较准确预测CSF/CNF,两者联合检测的预测效能更高。     

脓毒症相关急性呼吸窘迫综合征患者血清Lac、D-D、sTM、ESM-1的表达及其临床意义

摘要 目的：探讨脓毒症相关急性呼吸窘迫综合征（ARDS）患者血清乳酸（Lac）、D-二聚体（D-D）、可溶性血栓调节蛋白（sTM）、内皮细胞特异性分子-1（ESM-1）的表达及其临床意义。方法：选取2020年1月～2022年1月徐州医科大学附属医院重症医学科收治的375例脓毒症相关ARDS患者,根据入院时氧合指数（OI）差异分为轻度组（n＝96）、中度组（n＝152）和重度组（n＝127）,比较各组血清Lac、D-D、sTM、ESM-1水平,采用Spearman相关系数分析血清Lac、D-D、sTM、ESM-1与OI的相关性。根据28d内预后将患者分为死亡组（n＝137）和存活组（n＝238）,收集临床资料,采用多因素Logistic回归分析脓毒症相关ARDS患者预后的影响因素。采用受试者工作特征（ROC）曲线分析血清Lac、D-D、sTM、ESM-1对脓毒症相关ARDS患者预后不良的预测价值。结果：轻度组、中度组、重度组血清Lac、D-D、sTM、ESM-1水平依次升高（P＜0.05）。Spearman相关性分析结果显示：脓毒症相关ARDS患者的血清Lac、D-D、sTM、ESM-1水平与OI均呈负相关（P＜0.05）。死亡组年龄大于存活组,脓毒性休克、ICU停留时间≥10 d、机械通气时间≥3 d比例以及SOFA评分、血清Lac、D-D、sTM、ESM-1水平均高于存活组,OI低于存活组（P＜0.05）。多因素Logistic回归分析显示：脓毒性休克、SOFA评分≥13分、血清Lac、D-D、sTM、ESM-1水平较高是脓毒症相关ARDS患者预后不良的危险因素,而OI较高是预后不良的保护因素（P＜0.05）。ROC曲线分析结果显示：血清Lac、D-D、sTM、ESM-1联合检测预测脓毒症相关ARDS患者预后不良的AUC为0.907,明显高于各指标单独检测的0.785、0.747、0.796、0.789。结论：血清Lac、D-D、sTM、ESM-1水平升高与脓毒症相关ARDS病情严重程度和预后不良密切相关,对患者预后有一定预测价值。     

不同年龄女性急性ST段抬高型心肌梗死患者冠状动脉病变特点、PPCI治疗临床疗效的差异及院内死亡的危险因素分析

摘要 目的：分析不同年龄女性急性ST段抬高型心肌梗死（STEMI）患者冠状动脉病变特点、经急诊经皮冠状动脉介入（PPCI）治疗后的临床疗效差异及院内死亡的危险因素。方法：选取2018年1月~2022年3月期间在我院接受PPCI治疗的女性STEMI患者408例,根据患者不同的发病年龄将其分为A组（年龄≤65岁,n=161）与B组（年龄>65岁,n=247）。对比不同的发病年龄PPCI冠状动脉病变特点、治疗后的临床疗效差异及院内不良事件发生情况。单因素和多因素Logistic回归分析女性STEMI患者院内死亡的危险因素。结果：A组、B组的病变血管数量、钙化病变组间对比有统计学差异（P<0.05）。A组、B组的病变血管部位、术前TIMI血流分级、分叉病变组间对比无统计学差异（P>0.05）。两组主动脉内囊反搏术比例组间对比未见明显差异（P>0.05）,B组症状发生到血管开通时间（S-to-D）、门-球囊扩张时间（D-to-B）时间长于A组（P<0.05）。两组术中死亡、支架内血栓、BARC3~5级出血比例组间对比无统计学差异（P>0.05）。B组术后死亡的发生率低于A组（P<0.05）。根据患者不同的预后结局分为存活组（n=369）和死亡组（n=39）。单因素分析结果显示女性STEMI患者院内死亡与年龄、糖尿病、体质量指数（BMI）、Killip心功能分级、术前TIMI血流分级、术后TIMI血流分级、住院天数、S-to-D时间、D-to-B时间、收缩压（SBP）、舒张压（DBP）、白细胞计数（WBC）、中性粒细胞、血小板体积分布宽度（PDW）、左心室射血分数（LVEF）、肌酸激酶同工酶（CK-MB）有关（P<0.05）。多因素Logistic回归分析,结果显示年龄偏大、LVEF偏低、CK-MB偏高、术后TIMI血流分级0~I级、S-to-D时间偏长是女性STEMI患者院内死亡的危险因素（P<0.05）。结论：不同年龄女性STEMI患者冠状动脉病变特点、且PPCI 的治疗效果存在一定的差异。此外,年龄偏大、LVEF偏低、CK-MB偏高、术后TIMI血流分级0~I级、S-to-D时间偏长是女性STEMI患者院内死亡的危险因素。     

血清sACE2、Lp-PLA2与老年ST段抬高型心肌梗死患者心功能、心室重构及预后的关系研究

摘要 目的：探讨血清可溶性血管紧张素转化酶2（sACE2）、脂蛋白相关磷脂酶A2（Lp-PLA2）与老年ST段抬高型心肌梗死（STEMI）患者心功能、心室重构及预后的关系。方法：回顾性分析2018年1月至2021年12月期间本院收治的92例老年STEMI患者的临床资料,根据术后是否发生主要不良心血管事件（MACE）分为预后良好亚组和预后不良亚组,并纳入同期50例非心肌梗死患者作为对照组。采用酶联免疫吸附法检测血清sACE2水平,采用化学发光法检测血清Lp-PLA2水平,根据中位值水平为为低水平亚组和高水平亚组,比较亚组间心功能和心室重构指标[左室射血分数（LVEF）、左室收缩期内径（LVIDS）、左室短轴缩短率（LVFS）]差异,并进行Pearson相关性分析。采用受试者工作特征（ROC）曲线分析老年STEMI患者血清sACE2、Lp-PLA2水平预测MACE发生的效能。结果：（1）STEMI组患者血清sACE2和Lp-PLA2水平均显著高于对照组（P＜0.05）。（2）高sACE2亚组和高Lp-PLA2水平亚组患者LVEF显著低于低sACE2水平亚组和低Lp-PLA2水平亚组,LVFS、LVEDd和LVEDs显著大于低sACE2水平亚组和低Lp-PLA2水平亚组（P<0.05）。（3）血清sACE2、Lp-PLA2水平与STEMI患者LVEF呈显著负相关关系,与LVFS、LVEDd和LVEDs呈显著正相关关系（P<0.05）。（4）预后不良亚组患者血清sACE2和Lp-PLA2水平均显著高于预后良好亚组（P<0.05）。（5）血清sACE2和Lp-PLA2水平预测STEMI患者发生不良预后的AUC分别为0.885（95%CI：0.802~0.969）、0.907（95%CI：0..847~0.967）,最佳诊断Cut-off值分别为血清sACE2≥6355.48 pg/mL、血清Lp-PLA2≥292.73 ng/mL。结论：血清sACE2和Lp-PLA2水平与STEMI患者心功能和心室重构有密切关系,高水平表达对MACE发生具有良好的预测价值。     

血清ESM-1、VE-Cad、CC16水平与脓毒症并发急性呼吸窘迫综合征患者炎性因子及预后的关系研究

摘要 目的：探讨血清内皮细胞特异性分子-1（ESM-1）、血管内皮钙黏蛋白（VE-Cad）、Clara细胞分泌蛋白16（CC16）水平与脓毒症并发急性呼吸窘迫综合征（ARDS）患者炎性因子及预后的关系。方法：选取我院2018年10月～2020年1月收治的59例脓毒症并发ARDS患者为研究对象,记作观察组。另取同期于我院进行体检的60例健康志愿者作为对照组。比较两组血清ESM-1、VE-Cad、CC16及炎症因子水平,并以Pearson相关性分析血清ESM-1、VE-Cad、CC16与炎症因子的相关性。此外,将观察组患者按照预后分作死亡组27例和存活组32例,通过多因素Logistic回归分析脓毒症并发ARDS患者预后的影响因素。结果：观察组的血清ESM-1、VE-Cad、CC16水平均高于对照组（P＜0.05）。观察组的IL-6、CRP、PCT水平均高于对照组（P＜0.05）。Pearson相关性分析结果显示：脓毒症并发ARDS患者的血清ESM-1、VE-Cad、CC16水平与IL-6、CRP、PCT水平均呈正相关（P＜0.05）。多因素Logistic回归分析结果显示：年龄（较大）、入院24 h内APACHEⅡ评分（较高）以及血清ESM-1（升高）、VE-Cad（升高）、CC16（升高）、IL-6（升高）、CRP（升高）、PCT（升高）均是脓毒症并发ARDS患者死亡的危险因素,而氧合指数（升高）是患者死亡的保护因素（均P＜0.05）。结论：脓毒症并发ARDS患者血清ESM-1、VE-Cad、CC16水平存在明显升高,且与炎性因子以及预后密切相关,可作为脓毒症并发ARDS患者预后的辅助评估指标。     

血清NT-proBNP、HE4、β2-MG、sST2与扩张型心肌病患者心室重构的关系及对出院后短期预后的预测价值

摘要 目的：探讨血清N端脑钠肽前体（NT-proBNP）、人附睾蛋白4（HE4）、β2微球蛋白（β2-MG）、可溶性ST2（sST2）与扩张型心肌病（DCM）患者心室重构的关系及对出院后短期预后的预测价值。方法：选取2019年3月～2020年12月华中科技大学同济医学院附属同济医院收治的DCM患者74例,记作DCM组。另取同期健康体检者80例作为对照组。检测并比较两组血清NT-proBNP、HE4、β2-MG、sST2水平以及心室重构相关指标水平。以Pearson相关性分析血清NT-proBNP、HE4、β2-MG、sST2水平和各项心室重构参数的相关性。此外,将所有DCM组患者按照出院后是否发生因心力衰竭再住院和心血管死亡事件分作预后不良组33例以及预后良好组41例。比较两组各项基线资料以及血清NT-proBNP、HE4、β2-MG、sST2水平。多因素Logistic回归分析DCM患者出院后短期预后的危险因素。通过受试者工作特征（ROC）曲线分析血清NT-proBNP、HE4、β2-MG、sST2预测DCM患者出院后短期预后的效能。结果：DCM组血清NT-proBNP、HE4、β2-MG、sST2水平均高于对照组（P＜0.05）。DCM组左心室质量指数（LVMI）、左心室舒张末期容积（LVEDV）、左心室收缩末期容积（LVESV）水平均高于对照组,而左心室射血分数（LVEF）水平低于对照组（P＜0.05）。经Pearson相关性分析可得：血清NT-proBNP、HE4、β2-MG、sST2水平与LVMI、LVEDV、LVESV均呈正相关关系,而和LVEF均呈负相关关系（P＜0.05）。预后不良组年龄以及血清NT-proBNP、HE4、β2-MG、sST2水平均高于预后良好组（P＜0.05）。经多因素Logistic回归分析发现,年龄以及血清NT-proBNP、HE4、β2-MG、sST2水平均是DCM患者出院后短期预后的危险因素（P＜0.05）。经ROC曲线分析可得：血清NT-proBNP、HE4、β2-MG、sST2联合检测预测DCM患者出院后短期预后的曲线下面积、灵敏度以及特异度均高于上述四项指标单独检测。结论：血清NT-proBNP、HE4、β2-MG、sST2与DCM患者心室重构密切相关,且在预测患者出院后短期预后方面价值较高。     

血清UA、CysC、Lp-PLA2与急性脑梗死合并脑白质疏松症患者预后的关系研究

摘要 目的：探讨血清尿酸（UA）、胱抑素C（CysC）、脂蛋白相关磷脂酶 A2（Lp-PLA2）水平与急性脑梗死合并脑白质疏松症患者预后的关系。方法：选择2020年3月至2022年12月中国人民解放军联勤保障部队第九六0医院收治的113例急性脑梗死合并脑白质疏松症患者,检测血清UA、CysC、Lp-PLA2水平。随访1个月,根据改良Rankin量表（mRS）评分将患者分为预后良好组（0～2分,75例）和预后不良组（3分及以上,38例）。多因素Logistic回归分析急性脑梗死合并脑白质疏松症患者预后不良的危险因素,受试者工作特征曲线（ROC）分析血清UA、CysC、Lp-PLA2对急性脑梗死合并脑白质疏松症患者预后不良的预测价值。结果：预后不良组血清UA、CysC、Lp-PLA2水平高于预后良好组（P＜0.05）。多因素Logistic回归分析显示重度脑白质病变、高入院时NIHSS评分,高血清UA、CysC、Lp-PLA2水平是急性脑梗死合并脑白质疏松症患者预后不良的危险因素（P＜0.05）。联合血清UA、CysC、Lp-PLA2预测急性脑梗死合并脑白质疏松症患者预后的曲线下面积（AUC）为0.916,高于单独预测。结论：急性脑梗死合并脑白质疏松症患者血清UA、CysC、Lp-PLA2水平增高且与预后不良有关,联合血清UA、CysC、Lp-PLA2预测急性脑梗死合并脑白质疏松症患者预后不良价值较高。     

血清Trx1、FGL2与急性心肌梗死后心力衰竭患者预后的关系

摘要 目的：探讨血清硫氧还蛋白1（Trx1）、纤维蛋白原样蛋白2（FGL2）与急性心肌梗死后心力衰竭患者预后的关系。方法：选择2019年10月至2020年5月我院收治的158例急性心肌梗死后心力衰竭患者作为观察组,并根据心功能Killip分级分为Ⅱ级组54例、Ⅲ级组57例、Ⅳ级组47例。另选择同期我院收治的102例急性心肌梗死患者作为对照组。入院后采用酶联免疫吸附法（ELISA）检测所有患者血清Trx1、FGL2水平;观察组患者出院后随访2年,并根据是否出现主要不良心血管事件（MACE）将患者分为预后不良组和预后良好组。采用多因素Logistic回归分析影响急性心肌梗死后心力衰竭患者预后的相关因素,采用受试者工作特征（ROC）曲线评估血清Trx1、FGL2对急性心肌梗死后心力衰竭患者预后的预测价值。结果：观察组血清FGL2水平明显高于对照组,血清Trx1水平明显低于对照组（P<0.05）;心功能Killip分级Ⅳ级组患者血清Trx1水平明显低于Ⅱ级组、Ⅲ级组（P<0.05）,血清FGL2水平明显高于Ⅱ级组、Ⅲ级组（P<0.05）。预后不良组患者血清Trx1、LVEF均明显低于预后良好组,而年龄、血清FGL2及血尿酸、血肌酐、N末端B型利钠肽原（NT-proBNP）均明显高于预后良好组（P<0.05）,两组心功能Killip分级比例比较差异有统计学意义（P<0.05）。多因素Logistic回归分析显示,年龄（较高）、心功能Killip分级为Ⅳ级、Trx1下降、FGL2升高均是影响急性心肌梗死后心力衰竭患者预后的危险因素（P<0.05）。ROC曲线结果显示,血清Trx1、FGL2预测急性心肌梗死后心力衰竭患者预后的曲线下面积分别为0.807、0.811,两者联合检测预测急性心肌梗死后心力衰竭患者预后的曲线下面积为0.889。结论：急性心肌梗死后心力衰竭患者血清中Trx1水平降低,FGL2水平升高,且血清Trx1、FGL2水平与患者心功能分级及预后密切相关,可作为评估急性心肌梗死后心力衰竭患者预后的辅助性指标。     

血清同型半胱氨酸水平对急性ST段抬高型心肌梗死PCI术后患者左心室重构、心肌灌注和预后的影响

摘要 目的：探讨血清同型半胱氨酸（Hcy）水平与急性ST段抬高型心肌梗死（STEMI）患者经皮冠状动脉介入（PCI）术后左心室重构、心肌灌注以及预后的关系。方法：选择2018年2月至2020年1月我院收治的70例STEMI患者,根据入院时血清Hcy水平分为高水平Hcy组（Hcy＞30 μmol/L,41例）和低水平Hcy组（15≤Hcy≤30 μmol/L,29例）。PCI术后1个月、6个月、12个月检测左室重量指数(LVMI)和左心室射血分数(LVEF),复查冠脉造影,评价TIMI心肌灌注分级（TMPG）。Pearson相关或Spearman秩相关性分析Hcy水平与LVMI、LVEF、TMPG分级相关性。所有患者PCI术后随访12个月,记录患者随访期间全因死亡和主要不良心脏事件（MACE）发生情况。Cox风险比例回归分析PCI术后STEMI患者预后的影响因素。结果：高水平Hcy组PCI术后6、12个月 LVEF低于低水平Hcy组（P＜0.05）,LVMI高于低水平Hcy组（P＜0.05）,高水平Hcy组PCI术后心肌灌注不良发生率高于低水平Hcy组（P＜0.05）。Hcy水平与PCI术后6、12个月 LVEF呈负相关（P＜0.05）,与LVMI呈正相关（P＜0.05）,与PCI术后TMPG分级呈负相关（P＜0.05）。高水平Hcy组随访期间全因死亡和MACE发生率均高于低水平Hcy组（P＜0.05）。Cox风险比例回归分析结果显示Hcy、术前Gensini评分是STEMI患者PCI术后预后不良的影响因素（P＜0.05）。结论：高水平Hcy与STEMI患者PCI术后左心室重构、心肌灌注有关,且Hcy是STEMI患者PCI术后发生全因死亡和MACE的影响因素。     

Chiral separation and quantification of R/S-amphetamine, R/S-methamphetamine, R/S-MDA, R/S-MDMA, and R/S-MDEA in whole blood by GC-EI-MS

The enantioselective composition of the amphetamines is of interest, as the enantiomers show differences in their pharmacological effects and several methods for chiral separation of amphetamines have been described. Only a few methods have used whole blood as matrix and none of these separates both classic amphetamines (amphetamine and methamphetamine) and designer amphetamines (MDA, MDMA and MDEA). The aim of this study was, therefore, to develop a method for enantioselective analysis of AM, MA, MDA, MDMA, and MDEA in whole blood. The amphetamines were extracted from 0.5 g of whole blood by liquid-liquid extraction. After derivatization with R-MTPCl, the resulting diastereomers were separated by GC on a HP-5MS column and detected by SIM-MS. R-MTPCl was used as derivatization reagent because of the stability of this reagent and good separation of these analytes. Through the method, development time and temperature of the derivatization were optimized, and by admixture of 0.02% triethylamine it became possible to detect the amphetamines in adequately low concentrations as more analytes were derivatized. The method was validated and it was linear from 0.004 to 3 microg/g per enantiomer. The accuracy was within 91-115%, while the repeatability and reproducibility were < or =15% R.S.D. A method suitable for enantioselective separation and analysis of the amphetamines has been achieved, and the method was applied to analysis of whole blood samples originating from traffic and criminal cases and post mortem cases.     

Synthesis, characterization, cytotoxicity and antibacterial studies of chitosan, O-carboxymethyl and N,O-carboxymethyl chitosan nanoparticles

Chitosan (CS) is a naturally occurring biopolymer. It has important biological properties such as biocompatibility, antifungal and antibacterial activity, wound healing ability, anticancerous property, anticholesteremic properties, and immunoenhancing effect. Recently, CS nanoparticles have been used for biomedical applications. However, due to the limited solubility of CS in water its water-soluble derivatives are preferred for the above said applications. In this work, the nanoparticles of CS and its water-soluble derivatives such as O-carboxymethyl chitosan (O-CMC) and N,O-carboxymethyl chitosan (N,O-CMC) was synthesized and characterized. In addition, cytotoxicity and antibacterial activity of the prepared nanoparticles was also evaluated for biomedical applications.     

Cloning and expression of the Apa LI, Nsp I, Nsp HI, Sac I, Sca I, and Sap I restriction-modification systems in Escherichia coli

The genes encoding the ApaLI (5′-G^TGCAC-3′), NspI (5′-RCATG^Y-3′), NspHI (5′-RCATG^Y-3′), SacI (5′-GAGCT^C-3′), SapI (5′-GCTCTTCN1^-3′, 5′-^N4GAAGAGC-3′) and ScaI (5′-AGT^ACT-3′) restriction-modification systems have been cloned in E.␣coli. Amino acid sequence comparison of M.ApaLI, M.NspI, M.NspHI, and M.SacI with known methylases indicated that they contain the ten conserved motifs characteristic of C5 cytosine methylases. NspI and NspHI restriction-modification systems are highly homologous in amino acid sequence. The C-termini of the NspI and NlaIII (5′-CATG-3′) restriction endonucleases share significant similarity. 5mC modification of the internal C in a SacI site renders it resistant to SacI digestion. External 5mC modification of a SacI site has no effect on SacI digestion. N4mC modification of the second base in the sequence 5′-GCTCTTC-3′ blocks SapI digestion. N4mC modification of the other cytosines in the SapI site does not affect SapI digestion. N4mC modification of ScaI site blocks ScaI digetion. A DNA invertase homolog was found adjacent to the ApaLI restriction-modification system. A DNA transposase subunit homolog was found upstream of the SapI restriction endonuclease gene. Received: 15 April 1998 / Accepted: 3 August 1998     

Anthocyanins of Cephaelis, Cynomorium, Euterpe, Lavatera and Pinanga

The two malonylated pigments, malonylmalvin and malvidin 3-malonylglucoside, were identified in petals of Lavatera maritima, which belongs to the Malvaceae, a family known to synthesise such pigments. Zwitterionic anthocyanins could not be detected in four other newly examined sources and common unacylated pigments were recorded. Thus, the fruits of the palms Euterpe edulis and Pinanga polymorpha have a mixture of cyanidin 3-glucoside and cyanidin 3-rutinoside, while the fruit of Cephaelis subcoriacea is coloured by cyanidin 3-glucoside. The latter pigment was also obtained from the reddish brown inflorescence of the parasitic plant Cynomorium coccineum.     

Synthesis, characterization and redox behaviour of benzoyldiazenido- and oxorhenium complexes bearing N,N- and S,S-type ligands

The reactions of [ReCl₂{η²-N₂C(O)Ph}(PPh₃)₂] (1) with 2-aminopyrimidine (H₂Npyrm), 2,2′-bipyridine (bpy) and tetraethylthiuram disulfide (tds), in MeOH upon reflux, lead to the new η¹-(benzoyldiazenido)rhenium(III) complexes [ReCl{η¹-N₂C(O)Ph}(HNpyrm)(PPh₃)₂] (2) and [ReCl₂{η¹-N₂C(O)Ph}(bpy)(PPh₃)] (3), and the known oxo(diethyldithiocarbamato)dirhenium(v) complex [Re₂O₂(μ-O){Et₂NC(S)S}₄] (4), respectively. The Et₂NC(S)S ligands in 4 result from S-S bond rupture of tds molecules. The obtained compounds have been characterized by IR, ¹H, ³¹P{¹H} and ¹³C{¹H} NMR spectroscopies, FAB⁺-MS, elemental and single-crystal X-ray diffraction (for 2 and 4) analyses. Complex 2 represents the first structurally characterized Re compound derived from 2-aminopyrimidine. Besides, the redox behaviour of 2-4 in CH₂Cl₂ solution has been studied by cyclic voltammetry, and the Lever electrochemical ligand parameter (E_L) has been estimated, for the first time, for HNpyrm. The electrochemical results are discussed in terms of electronic properties of the Re centres and the ligands.     

Preparation, properties and crystal structure of two isomers of R,R,S,S- and R,S,R,S-[chloro(1,3,10,12,16,19-hexaazatetracyclo[17,3,1,1,0]tetracosane)copper(II)]

Two isomers (R,S,R,S- and R,R,S,S-) of five coordinate complex [Cu(L)Cl]⁺ have been separated and characterised. These two isomers have significantly different spectrochemical and electrochemical properties. Absorption maximum of R,S,R,S-[Cu(L)Cl]⁺ shifts to longer wavelength and its reduction potential shifts to more positive direction comparing those of R,R,S,S-[Cu(L)Cl]⁺. R,S,R,S-[Cu(L)Cl]⁺ is significantly distorted to trigonal-bipyramidal structure, whereas R,R,S,S-[Cu(L)Cl]⁺ retains almost square-planar geometry. The average bond distance of Cu-N in basal plane of R,S,R,S-[Cu(L)Cl]⁺ is longer by 0.024 Å than that of R,R,S,S-[Cu(L)Cl]⁺, whereas the bond distance of Cu-Cl in former is shorter by 0.200 Å than that in latter. The isolated square-planar complexes of R,R,S,S- and R,S,R,S-[Cu(L)](ClO₄)₂ are converted to the R,R,S,S- and R,S,R,S-[Cu(L)Cl]⁺ by the addition of Cl⁻ in nitromethane solution with the rate constants, k=1.70 (±0.02) and 8.31 (±0.07) M⁻¹ s⁻¹, respectively.     

Recent advances in the cryopreservation of shoot-derived germplasm of economically important fruit trees of Actinidia, Diospyros, Malus, Olea, Prunus, Pyrus and Vitis

This paper presents the advances made over the last decade in cryopreservation of economically important vegetatively propagated fruit trees. Cryopreservation protocols have been established using both dormant buds sampled on field-grown plants and shoot tips sampled on in vitro plantlets. In the case of dormant buds, scions are partially dehydrated by storage at − 5 °C, and then cooled slowly to − 30 °C using low cooling rates (c.a. 1 °C/h) before immersion in liquid nitrogen. After slow rewarming and rehydration of samples, regrowth takes place either through grafting of buds on rootstocks or excision of apices and inoculation in vitro. In the case of shoot tips of in vitro plantlets, the cryopreservation techniques employed are the following: controlled rate cooling procedures involving slow prefreezing followed by immersion in liquid nitrogen or vitrification-based procedures including encapsulation–dehydration, vitrification, encapsulation–vitrification and droplet-vitrification. The current status of cryopreservation for a series of fruit tree species including Actinidia, Diospyros, Malus, Olea, Prunus, Pyrus and Vitis is presented. Routine application of cryopreservation for long-term germplasm storage in genebanks is currently limited to apple and pear, for which large cryopreserved collections have been established at NCGRP, Fort Collins (USA), using dormant buds and in vitro shoot tips, respectively. However, there are a growing number of examples of pilot scale testing experiments under way for different species in various countries. Progress in the further development and application of cryopreservation techniques will be made through a better understanding of the mechanisms involved in the induction of tolerance to dehydration and cryopreservation in frozen explants.     

Purification, Characterization, and Crystallization of anN-HydroxyarylamineO-Acetyltransferase fromSalmonella typhimurium

TheN-hydroxyarylamineO-acetyltransferase fromSalmonella typhimuriumhas been expressed as a histidine-tagged fusion protein inEscherichia coliand purified to apparent homogeneity using single-step immobilized metal ion chromatography. Sufficient quantities of the purified protein have been obtained to allow its characterization by physical methods including dynamic light scattering and electrospray mass spectrometry. The substrate specificity and temperature sensitivity of the enzymatic activity have also been assessed. The enzyme has been crystallized from sodium, potassium tartrate and X-ray diffraction data have been obtained to allow the identification of an orthorhombic unit cell, point group P2₁2₁2, with dimensionsa= 137 Å,b= 223 Å, andc= 105 Å. These crystals will provide a route to a crystallographic determination of the structure of the protein.     

First records of flower biology and pollination in African Annonaceae: Isolona, Piptostigma, Uvariodendron, Monodora and Uvariopsis

Seven species from five genera of Annonaceae were studied with regard to their flower biology and pollination in the Southwest Province of Cameroon, West Africa. They have protogynous hermaphroditic flowers, with exception of Uvariopsis species, which are monoecious. Fused petals of Isolona campanulata remain apically spreading and open during anthesis but form a deep basal urceolate tube around the reproductive organs. At anthesis the yellow pendent flowers emit a fruit-like scent and attracted small beetles, the likely pollinators. Piptostigma sp. flowers also emit a fruit-like scent but provide a closed pollination chamber formed by the three inner petals. Small staphylinid beetles attracted during the female stage of anthesis are released from the flowers at the end of the male stage 2-3 days later. Both species have diurnal anthesis, attracting and releasing the flower visitors during daytime. In contrast, Uvariodendron connivens and U. calophyllum have nocturnal anthesis with floral thermogenesis, produce spicy, aromatic and fruity scents and attract large Scarabaeidae beetles, the pollinators, along with many curculionid beetles, which were principally predators of the thick petals. The very large flowers of Monodora tenuifolia have yellowish petals which are spotted with dark red markings. Together with the sweetish, slightly disagreeable scent the flowers attract flies, principally dung flies. The two investigated Uvariopsis species are monoecious with pistillate and staminate flowers being functional at the same time. The violet red flowers of U. bakeriana visually seem to mimic the fruiting body of certain stinkhorn fungi (Phallaceae) although without producing their strong unpleasant carcass stench. Flower-visiting dung flies were rare. Conversely, U. congolana has a strong fungus-like scent, its flowers are presented at litter height and dung flies living in the litter were the flower visitors, albeit sporadic. The 4-5 days lasting anthesis of both Uvariopsis species appears to be an evolutionary consequence of their diffuse pollinator spectra. The studied African Annonaceae therefore have either cantharophilous or myiophilous/sapromyiophilous flowers with, in part, respectively, remarkably long anthesis, thermogenesis, and widely open, large flowers - all attributes unknown or rare in the hitherto better studied Neotropical Annonaceae.     

Synthesis,Characterization, and Functionalization of Hybrid Au/CdS and Au/ZnS Core/Shell Nanoparticles

Plasmonic nanoparticles are an attractive material for light harvesting applications due to their easily modified surface, high surface area and large extinction coefficients which can be tuned across the visible spectrum. Research into the plasmonic enhancement of optical transitions has become popular, due to the possibility of altering and in some cases improving photo-absorption or emission properties of nearby chromophores such as molecular dyes or quantum dots. The electric field of the plasmon can couple with the excitation dipole of a chromophore, perturbing the electronic states involved in the transition and leading to increased absorption and emission rates. These enhancements can also be negated at close distances by energy transfer mechanism, making the spatial arrangement of the two species critical. Ultimately, enhancement of light harvesting efficiency in plasmonic solar cells could lead to thinner and, therefore, lower cost devices. The development of hybrid core/shell particles could offer a solution to this issue. The addition of a dielectric spacer between a gold nanoparticles and a chromophore is the proposed method to control the exciton plasmon coupling strength and thereby balance losses with the plasmonic gains. A detailed procedure for the coating of gold nanoparticles with CdS and ZnS semiconductor shells is presented. The nanoparticles show high uniformity with size control in both the core gold particles and shell species allowing for a more accurate investigation into the plasmonic enhancement of external chromophores.