预聚物分子量对立体复合聚乳酸固相缩聚产物结构和性质的影响

采用乳酸作为引发剂、辛酸亚锡作为催化剂,引发丙交酯开环聚合制得分子量不同的具备缩聚活性的预聚物L-聚乳酸（PLLA）和D-聚乳酸（PDLA）,将重均分子量（M_w）相近的预聚物熔融共混后制成前体进行固相缩聚。采用核磁共振（NMR）、凝胶渗透色谱（GPC）、差示扫描量热（DSC）及X射线衍射（XRD）分析了固相缩聚产物的链结构、分子量、热性能及晶体结构。结果表明,固相缩聚产物具有立体嵌段结构。预聚物的分子量大小将影响固相缩聚前体中均相晶体和立体复合晶体的相对含量,进而影响固相缩聚产物的结构。当预聚物PLLA和PDLA的M_w≈5×10⁴时,固相缩聚产物重均分子量的涨幅最大,最终达到1.83×10⁵。因此,采用M_w≈5×10⁴的预聚物进行固相缩聚有利于产物中立体复合晶体结晶度的提高。     

无规聚醚多元醇化学改性木质素薄膜的制备与表征

采用无规聚醚多元醇对木质素进行了化学改性,在木质素分子结构中引入柔性多元醇分子链,通过热压法制备了聚醚多元醇改性木质素的高分子薄膜。采用傅里叶变换红外光谱(FT-IR)、热重(TG)和动态热机械分析(DMA)等手段表征了聚醚多元醇改性木质素的结构和热力学性能。考察了木质素的质量分数、无规聚醚多元醇的数均分子量以及异氰酸官能团与体系总羟基的物质的量之比(n_NCO:n_OH)对木质素薄膜力学性能的影响。结果表明:聚醚多元醇通过氨基甲酸酯化学键接到木质素分子上,改性之后其热稳定性明显提高,玻璃化转变温度为72℃;当n_NCO:n_OH为1.5:1,无规聚醚多元醇的数均分子量为1 500以及木质素质量含量为33%时,薄膜的综合力学性能最佳。     

烧伤脓毒血症患者血清降钙素原和血浆凝溶胶蛋白水平的变化及意义

目的 探讨烧伤脓毒血症患者血清降钙素原（PCT）和血浆凝溶胶蛋白（GSN）水平的变化及意义。方法 选取2008年2月至2013年3月恩施州中心医院烧伤整形科118例严重烧伤患者,分为烧伤脓毒血症组（n=51）和烧伤非脓毒血症组（n=67）,选取健康者45例作为对照组,烧伤脓毒血症组患者根据预后,分为死亡组（n=18）和存活组（n=33）。分别于患者入院当天（T₁）、第2天（T₂）、第4天（T₃）、第7天（T₄）和第14天（T₅）,以及对照组体检当天,利用全自动免疫分析仪检测PCT水平,利用酶联免疫吸附试验（ELISA法）检测血浆中GSN含量,利用logistic回归分析血清PCT和血浆GSN水平对患者预后的影响。结果 烧伤脓毒血症组患者T_1-4时血清PCT水平均高于烧伤非脓毒血症组和对照组,差异均有统计学意义（P < 0.05）;烧伤脓毒血症组患者T_2-5时血浆GSN水平均低于烧伤非脓毒血症组,差异均有统计学意义（P < 0.05）;烧伤脓毒血症组患者T_1-5时血浆GSN水平均低于烧伤非脓毒血症组和对照组,差异均有统计学意义（P < 0.05）;死亡组患者T_1-5时血清PCT水平均高于存活组,而T_1-5时血浆GSN水平均低于存活组,差异均有统计学意义（P < 0.05）;Spearman相关分析显示,烧伤脓毒血症组患者血清PCT总体水平与患者预后呈正相关（r=0.437,P < 0.05）,而血浆GSN水平与患者预后呈负相关（r=-0.518,P < 0.05）;logistic回归分析显示,血清PCT总体平均值和血浆GSN总体平均值均是影响患者预后的独立危险因素（P < 0.05）。结论 烧伤脓毒血症患者血清PCT和血浆GSN水平随病情变化而动态改变,PCT总体水平与患者预后呈正相关,而血浆GSN水平与患者预后呈负相关,可作为早期预测患者病情及预后的指标。     

氮硼共掺杂有序介孔碳的制备及性能

采用硬模板法,以间位碳硼烷为硼源、3-氨基苯基乙炔树脂为氮源和碳源、介孔二氧化硅（SBA-15）为硬模板,成功制备了氮硼共掺杂的有序介孔碳材料（NBC）。采用X射线衍射（XRD）、N₂吸附-脱附测试、透射电镜（TEM）和X射线光电子能谱（XPS）研究了前驱体中B与N的物质的量之比（n_B/n_N）对NBC结构的影响。采用紫外-可见分光光度计（UV-Vis）研究了NBC对甲基橙染料的吸附性能。结果表明：NBC具有二维六方的有序结构,孔径可调且分布集中在3~6 nm。其中,NBC-1.0样品（n_B/n_N=1.0）具有最高的比表面积（1 560 m²/g）、最大比孔容（1.92 cm³/g）及高度有序性。相比于传统的活性炭吸附剂（吸附量61 mg/g）,NBC-1.0可以实现对甲基橙染料的快速、有效吸附,其吸附量可达214 mg/g。     

支化及交联聚对苯二甲酸乙二醇酯的制备及其发泡性能

采用聚对苯二甲酸丁二醇酯（PBT）与苯乙烯-甲基丙烯酸缩水甘油酯低聚物（GS）的化学键合产物（PBT-GS）为扩链剂,与聚对苯二甲酸乙二醇酯（PET）熔融反应,制备了支化及交联PET。分析了反应过程的扭矩变化,以及支化及交联PET的特性黏数、交联度和流变性能。并以超临界CO₂为物理发泡剂,通过釜式发泡对比了支化及交联PET的可发性,制备了平均泡孔直径为50~75 μm、泡孔密度为1×10⁸~4×10⁸ cells/cm³、泡孔形貌规整的PET泡沫材料,研究了发泡温度和饱和压力对发泡过程的影响。     

一种用于FDM型3D打印的改性PBT

以对苯二甲酸(PTA)、间苯二甲酸(PIA)、癸二酸(SA)和1,4-丁二醇(BDO)为原料,通过直接酯化和减压缩聚的方法制备了一种适合熔融沉积打印(FDM)型3D打印的改性聚对苯二甲酸丁二醇酯(PBT)——聚对苯二甲酸间苯二甲酸癸二酸丁二醇酯(PBTIS)。采用核磁共振氢谱(¹H-NMR)、凝胶渗透色谱法(GPC)、差示扫描量热法(DSC)、黏度计和熔体仪、万能电子拉力机和冲击试验机分别研究了其热性能、流变性能和力学性能。研究表明:当n(PTA):n(PIA)=7:3,SA的物质的量分数为3%~5%时,PBTIS具有合适的熔点、良好的拉伸强度和弯曲强度及悬梁缺口冲击强度等力学性能。用桌面拉丝挤出机将PBTIS样品制成卷材并用3D打印机打印,结果表明其可以流畅地打印出所设计的三维物件。     

图依谱半径的排序

n阶（n≥6）简单连通无向图G的谱半径记为ρ（G）。依G的谱半径从大到小进行了排序,得到如下结果：ρ（K_n）>ρ（K_n－K₂）>ρ（K_n－P₃）>ρ（K_n－2K₂）>ρ（K_n－K_1,3）>ρ（K_n－C₃）>ρ（K_n－P₄）>ρ（K_n－P₃∪K₂）。     

基于瞬时纳米沉淀法制备尺寸可控载药纳米粒子

合成了5种具有不同分子量、不同亲疏水链段比例的两亲性嵌段共聚物——甲氧基聚乙二醇-b-聚己内酯（mPEG-b-PCL）,并以其为表面活性剂,采用瞬时纳米沉淀（Flash Nano Precipitation,FNP）法制备出一系列包裹模型药物β-胡萝卜素的纳米粒子。通过改变两亲性共聚物的结构、分子量、浓度及溶剂体积比（V（H₂O）：V（THF））,成功实现了对纳米粒子尺寸的调控。实验结果表明：聚合物亲水链段分子量比例增大,则纳米粒子尺寸减小;当亲水链段分子量比例相同时,聚合物分子量越大,则纳米粒子尺寸越小;当聚合物质量浓度较高（10.0 g/L）时,制备的纳米粒子粒径分布较窄,粒子性能较稳定。     

水杨醛亚胺锆络合物的合成及其催化乙烯聚合

以3-叔丁基-5-甲氧基水杨醛和邻取代苯胺为原料,合成了两个水杨醛亚胺配体（1,2）及相应的锆络合物（3,4）。用质谱（MS）、核磁共振氢谱（¹H-NMR）和核磁共振碳谱（¹³C-NMR）等方法表征了配体及络合物的结构,采用流变仪、差示扫描量热仪（DSC）对聚合物进行了分析。研究了乙烯压力、聚合温度、时间、溶剂、铝锆物质的量之比（n_Al：n_Zr）等对络合物催化性能和聚乙烯分子量的影响。结果表明,在甲基铝氧烷（MAO）的助催化下,锆络合物在甲苯中对乙烯聚合具有较好的催化活性,所得聚合物为超高分子量聚乙烯。在30℃、0.9 MPa下,络合物4在正己烷中的催化活性达到60.2 kg/（mmol·h）,聚乙烯的黏均分子量最高可达6.6×10⁶,分子量分布为2.4,聚合过程具有良好的可控性。     

醇钾及酚钾在甲基丙烯酸甲酯阴离子聚合中的应用

以正丁基锂（n-BuLi）为引发剂,叔丁醇钾（t-BuOK）和苯酚钾（POK）为副反应抑制剂,实现了甲基丙烯酸甲酯（MMA）在四氢呋喃（THF）溶剂中的阴离子聚合。采用凝胶渗透色谱（GPC）、核磁共振氢谱（¹H-NMR）等研究了产物的数均分子量、分子量分布（MWD）和分子结构。结果表明：t-BuOK与n-BuLi之间发生反离子交换反应使活性中心的反离子Li⁺被K⁺替换,从而在一定程度上抑制了MMA聚合过程中的副反应,当n（t-BuOK）/n（n-BuLi）≥10时,可在0℃下实现MMA的可控阴离子聚合;PMMA分子量分布较窄（1.22）,且数均分子量与设计值十分接近,MMA聚合的副反应得到了有效控制;进一步添加的POK能与活性中心的K⁺配合,促进对MMA聚合副反应的抑制,使MMA的可控阴离子聚合能在较高温度（40℃）下得以实现,所合成的聚甲基丙烯酸甲酯（PMMA）数均分子量分布窄（1.24）且数均分子量符合设计值。     

Value of D-Dimers in patients with acute aortic dissection

Objective: To evaluatel the value of D-dimers in patients with acute aortic dissection (AAD). Methods: This study consisted of 16 patients with AAD and 27 non-AAD patients. Serum D-dimets were measured by Sta-Liatest D-DI immunoturbidimetric assay. Results: D-dimer level was higher (P ＜ 0.001) in patients with AAD(7.91 ± 5.52 μg/ml) than that in non- AAD group(1.57±1.24 μg/ml). D-dimer was positive (＞0.4 μg/ml) in all patients with AAD and in 10 control group patients (37%). Among patients with acute AAD, D-dimers tended to be higher in Stanford A than in Stanford B (8.67 ± 4.31 μg/ml vs. 3.24±1.27 μg/ml, P ＜0.01). D-dimer values tended to be higher in more extended disease(3.84 ± 1.65 μg/ml, 8.57 ± 3.58 μg/ml and 11.87 ± 5.69 μg/ml in thoracic aorta, thoracic and abdominal aorta, thoracic and abdominal aorta and iliacal arteries, respectively, P ＜ 0.05 for both 8.57 ± 3.58 and 11.87 ± 5.69 vs. 3.84 ± 1.65 ). Including the control group into the analysis, we found a sensitivity of 100%, a negative predictive value of 100%, and a specificity of 66% and a positive predictive value of 64% for D-dimer in diagnosis of AAD in our patients with suspected AAD. Conclusion: D-dimer was elevated in patients with AAD. A negative D-dimer test result could be useful in excluding AAD.     

Research of combined liver-kidney transplantation model in rats

Objective： To set up a simple and reliable rat model of combined liver-kidney transplantation. Methods： SD rats served as both donors and recipients. 4℃ sodium lactate Ringer＇s was infused from portal veins to donated livers,and from abdominal aorta to donated kidneys, respectively. Anastomosis of the portal vein and the inferior vena cava （IVC） inferior to the right kidney between the graft and the recipient was performed by a double cuff method, then the superior hepatic vena cava with suture. A patch of donated renal artery was anastomosed to the recipient abdominal aorta. The urethra and bile duct were reconstructed with a simple inside bracket. Results： Among 65 cases of combined liver-kidney transplantation, the success rate in the late 40 cases was 77.5%. The function of the grafted liver and kidney remained normal. Conclusion： This rat model of combined liver-kidney transplantation can be established in common laboratory conditions with high success rate and meet the needs of renal transplantation experiment.     

BLOOD PRESSURE CHANGE WITH AGE IN SALT-SENSITIVE TEENAGERS

Objective To observe blood pressure change with age in salt-sensitive teenagers whose salt sensitivity were determined by repeated testing.Methods Salt sensitivity was determined through intravenous infusion of normal saline combined with volume-depletion by oral diuretic furosemide in 55 teenagers. After five years, salt sensitivity was re-examined and subject blood pressure was followed up. Blood pressure changes in salt-sensitive teenagers were compared to that of non-salt sensitive teenagers over five years.Results After 5 years, the repetition rate of salt sensitivity determined by intravenous saline loading is 92.7%. In teenagers with salt sensitivity on the baseline, both the systolic blood pressure increments and increment rates were much higher than non-salt sensitive teenagers (12.7±12.1 mmHg vs. 2.8±5.2 mmHg, P＜ 0.01; 12.2%± 12.0% vs. 2.5% ±4.4%, P＜ 0.001,respectively). There was a similar trend for diastolic blood pressure (8.4 ± 6.4 mmHg vs. 3.7 ± 6.4 mmHg, P = 0.052; 13.2% ±10.6 % vs. 6.8%± 10.1%, P = 0.053, respectively).Conclusions Salt sensitivity determined by intravenous saline loading showed good reproducibility. Blood pressure increments with age were much higher in salt-sensitive teenagers than non-salt sensitive teenagers, especially in terms of systolic blood pressure.     

安心颗粒对急诊经皮冠状动脉介入术后生活质量影响的研究

目的：评价使用安心颗粒对急诊经皮冠状动脉介入术（PPCI）术后生活质量的影响.方法：将160例接受PPCI的急性ST段抬高型心肌梗死患者随机分为安心颗粒组（术前顿服安心颗粒8.8g,术后安心颗粒4.4 g/次,每日2次）和对照组（仅接受基础药物治疗）.所有患者均服用阿司匹林、氯吡格雷和阿托伐他汀.分别在入院时、出院前1d、出院后180 d时,应用心肌梗死多维度量表（MIDAS）、中文版SF-36评价量表对患者生活质量评分.并观察术后30 d以内的出血并发症、血小板减少症发生情况.结果：入院时和出院前1d,两组患者的心肌梗死MIDAS、SF-36量表评分比较无差异（P＞0.05）;出院后180 d时,与对照组比较,安心颗粒组MIDAS、SF-36评分明显减低（P＜0.05）;组内与入院时比较,两组出院前1d、出院后180 d时,MIDAS、SF-36评分均降低（P＜0.05）.两组患者在随访期间均无大量出血、少量出血、重度和极重度血小板减少症发生,安心颗粒组有4例、对照组有7例发生不明显出血（P＞0.05）.两组发生轻度血小板减少症的患者数比较无差异（P＞0.05）.结论：PPCI使用安心颗粒,能改善急性ST段抬高型心肌梗死患者的生活质量,且不增加出血风险.     

The comparative studies of the influences of Urapidil and Nicardipine on sino-atrial node function, atrio-ventricular node function and hemodynamics

Objective:To investigate the influences of urapidil and nicardipine on rabbit sinus function,atrio-ventricular node function and hemodynamics.Methods:Thirty-two Angora's rabbits were selected and randomly divided into four groups.U1 group:urapidil 0.25 mg/kg;U2 group:urapidil 0.5 mg/kg;N1 group:nicardipine 10 μg/kg;N2 group:nicardipine 20 μg/kg.All these medicine were administrated within 30 seconds.Measurements were taken before and after the administration of urapidil or nicardipine for the following data:mean blood pressure(MAP),heart rate(HR),sino-atrial conduction time(SACT),maximal sinoatrial recovery time(SNRTmax)corrected sinus node recovery time(CSNRT),index of sinus node recovery time(SNRTI),Wenckebach A-V conduction frequency (WB),and P-R interval.Results:Significant MAP and HR changes were identified in all of the four groups before and after administration of both urapidil and nicardipine.No significant changes could be found in the rest of the parameters.Intergroup analysis showed that SACT and CSNRT of N1 and N2 groups were shorter than those of the U2 group(P＜0.01);the MAP decreased(P＜0.01)and the HR increased drastically(P＜0.01).Conclusions:Neither urapidil(0.25 mg/kg,0.5 mg/kg)nor nicardipine(10μg/kg,20μg/kg)has any significant influence on rabbit sinus function or rabbit atrio-ventricular node function.Nicardipine could be a better choice than urapidil for parafunctional sinus node patients.     

Expression of OPGmRNA and ODFmRNA in the patients of hip fracture due to osteoporosis

Objective：To investigate the gene expression of osteoprotegerin（OPG） and osteoclast differentiation factor（ODF） in the bone tissue of patients with hip fracture due to osteoporosis. Methods：OPGmRNA and ODFmRNA in the bone tissue in 50 cases of osteoporosis sufferers（over 50 years old） with hip fracture（Observer Group） and 30 cases of hip facture sufferers with no osteoporosis（Control group） were analyzed with the Semi-Quantitative RT-PCR method. Results：The mRNA expressed of ODF, OPG were both high in the patients with hip fracture. In the control group, the expression of OPG mRNA was observed, while the expression of ODF mRNA was very slight. Conclusion：Aged patients contained all signals including OPG, ODF that are essential for inducing osteoclastogenesis and promoting bone resorption.     

The clinicopathological and immuohistochemical analysis of solid-pseudopapillary tumor of the pancreas： report of 9 cases

Objective：To investigate the clinical features, pathological characteristics and immunophenotype of solid-pseudopapillary tumor of the pancreas（SPTP）. Methods：Nine surgically treated cases of SPTP were retrospectively reviewed. Hematoxylin and Eosin（HE） staining and immunohistochemical staining were used to analyze all cases, and the general clinical data was collected. Results：Six patients were asymptomatic except for a palpable mass. Two patients complained of vague-epigastric pain. One patient appeared jaundice. The tumor was encapsulated and solid tissues alternately with cystic tissues. Histologically, the histological structure of solid portion was pseudopapillary with a fibrovascular core. Tumor cells were uniform and medium-sized which were arranged in sheets ets or nests or pseudopapillary patterns. Immunohistochemical studies demonstrated that SPTP proved positive in vimentin（9/9 cases）, AAT（9/9 cases）, NSE（9/9 cases）, ACT（7/9 cases）, CK20（2/9 cases）, CgA（1/9 cases）, S-100（3/gcases）, PR（4/gcases）, Syn（3/9 cases） and CD56（5/9cases）, negative in CEA and ER. Conclusion：SPTP is a tumor predominantly occurring in young women frequently without special symptoms. This tumor has various characteristical histological patterns with different immunophenotype.     

Dynamic Changes in Serum Estradiol and Progesterone levels in Patients of Premenstrual Syndrome with Adverse Flow of Liver-qi

Objective:To probe into the influence of changes of ovarian hormones on the pathogenesis of the specific sub-type premenstrual syndrome(PMS)and reveal partial microcosmic mechanisms of adverse flow of liver-qi.Methods:Estradiol(E2)and progesterone(P)levels in serum were determined at different phases of menstrual cycle by radioimmunoassay.Results:In the group of PMS with adverse flow of liver-qi.the secretive peak value Of E2 and P at the follicular phase significantly decreased,and the secretive peak value at the luteal phase did not come into being.Conclusions:Low E2 and P secretive peak at the follicular phase and absence of secretive peak at the luteal phase is one of the microcosmic mechanisms of PMS with adverse flow of liver-qi.One of the pathophysiologic mechanisms of specific sub-type PMS is probably the continuous low level of E2and P.     

Real-time Three-dimensional Echocardiography in Assessment of Left Ventricular and Right Ventricular Volumes

Real-time three-dimensional echocardiography (RT3DE)is a new ultrasound technique that enables dynamic threedimensional visualization and quantification of the heart in real time. Investigation of feasibility and methodology of RT3DE in determining left ventricular (LV) and right ventricular (RV) volumes, RT3DE was performed in 35 normal adults using Philips SONOS 7500 system with a 2-4 MHz matrix array transducer. The 60°×60° "pyramid" volume database was obtained and analyzed on a TomTec echo workstation. Both LV and RV volumes were calculated with four 3DE methods (i.e. apical 2, 4, 8, and 16-plane) through manually tracing ventricular endocardial borders in end diastole and end systole. Stroke volumes were then calculated. LV volume was also measured by 2DE Simpson's rule using GE VIVID 7 ultrasound machine.     

SCREENING FOR A 21-CHROMOSOME ABNORMALITY IN PREIMPLANTED EMBRYOS OF ELDERLY WOMEN

Increasing maternal age is the only etiological factor unequivocally linked to Down's syndrome in humans. The occurrence rate of newborns with Down's syndrome is about 1/220 in women over 35 years old. However, the occurrence rate in embryos fertilized in vitro, of the elder woman is unclear. Using FISH we screened the number of chromosome 21 in preimplanted embryos of 5 elderly women (average age, 38.4 years) to study the feasibility and necessity of screening trisomy 21 in embryos in patients over 35 years old at the in vitro fertilization (IVF) center.