ε-己内酯与DL-丙交酯共聚物的体内降解性能

背景：ε-己内酯与DL-丙交酯共聚后具有良好的生物相容性和可调控的降解速率,它的应用与其体内降解性能有着重要关系。 目的：观察聚(己内酯-co-DL-丙交酯)在大耳白兔体内的降解性能。 方法：将不同配比DL-丙交酯和ε-己内酯组成的聚(己内酯-co-DL-丙交酯)制备成不同尺寸的试样,植入到日本大耳白兔背部皮下,定期观察试样的形态、失重率、相对分子质量和热性能。 结果与结论：随着ε-己内酯投料比的增加,聚(己内酯-co-DL-丙交酯)形状保持能力增强,降解速度减慢;相同共聚组成的试样,尺寸越大,降解速度越快。     

定向拉伸工艺对可吸收肩袖补片力学性能的影响

目的研究定向拉伸工艺对不同可吸收补片力学性能的影响,评价其作为肩袖损伤修复补片的潜力。方法采用定向拉伸工艺制备聚乳酸基材料的可吸收补片,设定不同的定向拉伸温度(50～80℃)和拉伸比(0. 5～4. 3),研究不同参数对不同材料可吸收补片力学性能的影响,同时对其热性能、结晶性能和表面形貌进行表征。结果定向拉伸温度和拉伸比可以调控可吸收补片的拉伸强度和拉伸应变、热性能、结晶性能和微观形貌。当拉伸温度分别为60、70、70℃,对应的拉伸比分别为3、3、4. 3时,聚-L-丙交酯-乙交酯的共聚物(PLGA)、聚-L-丙交酯-D,L-丙交酯的共聚物(PLDLLA)、聚-L-丙交酯-ε-己内酯的共聚物(PLC)最大拉伸强度分别为(74±7)、(97±6)、(107±8) MPa,大于犬类冈下肌腱的力学强度(40 MPa),但仅有PLDLLA补片的应变满足天然肩袖的柔韧性。结论定向拉伸工艺可以提高可吸收补片的力学性能,PLDLLA补片具有增强肩袖撕裂的潜力。     

聚DL-丙交酯/羟基磷灰石(PDLLA/HA)复合材料(I):制备及力学性能

将羟基磷灰石(HA)与DL-丙交酯(DL-LA)按一定比例混合,在辛酸亚锡引发下开环聚合得到HA微粒填充的聚DL-丙交酯/羟基磷灰石(PDLLA/HA)复合材料.在一定引发剂浓度下,HA的含量越大,粒径越小,PDLLA的分子量越低.扫描电子显微镜观察HA微粒均匀分布在PDLLA基质中,当PDLLA的分子量在175000～245000范围内,HA含量(HAwt%)为30%时,复合材料的弯曲强度达90MPa,剪切强度为72MPa,模量为6.9GPa,均高于其它体系.HA的引入不仅提高了材料的初始力学强度,而且还延缓了PDLLA的降解速度.     

聚DL—丙交酯／羟基磷灰石（PDLLA／HA）复合材料（Ⅰ）：制备及力学性能

将羟基磷灰石（HA）与DL－丙交酯（DL－LA）按一定比例混合,在辛酸亚锡引发下开环聚合得到HA微粒填充的聚DL－丙交酯／羟基磷灰石（PDLLA／HA）复合材料。在一定引发剂浓度下,HA的含量越大,粒径越小,PDLLA的分子量越低,扫描电子显微镜观察HA微粒均匀分布在PDLLA基质中,当PDLLA的分子量在175000－245000范围内,HA含量（HAwt%）为30％时,复合材料的弯曲强度达90MPa,剪切强度为72MPa,模量为6．9GPa,均高于其它体系。HA的引入不仅提高了材料的初始力学强度。而且还延缓了PDLLA的降解速率。     

模压挤出条件对聚(D,L-乳酸)及其复合材料力学性能的影响

在辛酸亚锡的催化下由丙交酯开环聚合制备了聚（D，L）-乳酸（PDLLA），并用二苯基甲烷二异氰酸酯（MDI）作为扩链剂分别合成了MDI扩链聚（D，L）-乳酸（PDLLA/MDI）和MDI扩链聚（D，L）-乳酸/羟基磷灰石（PDLLA/HA/MDI）复合材料，采用自行设计的模压挤出设备着重研究了成型加工条件对这两类可生物降解材料力学性能的影响，实验结果表明，在最佳条件下PDLLA和PDLLA/MDI的弯曲强度分别为35.1MPa和51.3MPa，弯曲模量分别为2413.6MPa和1830.9MPa,PDLLA/HA和PDLLA/HA/MDI复合材料的弯曲强度分别为31.2MPa和55.4MPa。弯曲模量分别为1735.0MPa和2068.5MPa，可见，MDI扩链可显著提高PDLLA和PDLLA/HA复合材料的力学性能。     

聚DL-丙交酯/羟基磷灰石(PDLLA/HA)复合材料(I):制备及力学性能

将羟基磷灰石 (HA)与DL 丙交酯 (DL LA)按一定比例混合 ,在辛酸亚锡引发下开环聚合得到HA微粒填充的聚DL 丙交酯 /羟基磷灰石 (PDLLA/HA)复合材料。在一定引发剂浓度下 ,HA的含量越大 ,粒径越小 ,PDLLA的分子量越低。扫描电子显微镜观察HA微粒均匀分布在PDLLA基质中 ,当PDLLA的分子量在 175 0 0 0～ 2 45 0 0 0范围内 ,HA含量 (HAwt %)为 30 %时 ,复合材料的弯曲强度达 90MPa ,剪切强度为 72MPa,模量为 6 .9GPa ,均高于其它体系。HA的引入不仅提高了材料的初始力学强度 ,而且还延缓了PDLLA的降解速度。     

聚(L-丙交酯-ε-己内酯)/交联聚乙烯吡咯烷酮输尿管支架植入大鼠膀胱后的组织相容性

文题释义： 聚(L-丙交酯-ε-己内酯)管：以辛酸亚锡作为催化剂催化L-丙交酯和ε-己内酯的本体开环共聚合制得的生物医用材料,具有良好的可降解性、力学性能及生物安全性,作为支架构建的基础材料已被广泛研究,但由于其疏水性在组织工程中的应用受到限制。 交联聚乙烯吡咯烷酮：为一种亲水性聚合物,具有优良的生理惰性和生物相容性,同时具备很强的吸水能力,制备成输尿管支架后能降低支架表面的湿态摩擦,更重要的是利用自身非常好的吸水膨胀性,可在输尿管支架内部造成很高的压力,提高支架管的降解速率,并促使可降解组分聚(L-丙交酯-ε-己内酯)共聚物崩解成小碎片。 背景：随着组织工程学、材料学、生物力学等学科的发展,研制新型可生物降解输尿管支架管成为目前研究的重点。前期研究制备了聚(L-丙交酯-ε-己内酯)/交联聚乙烯吡咯烷酮输尿管支架。 目的：探索聚(L-丙交酯-ε-己内酯)输尿管支架植入SD大鼠膀胱内的组织相容性。 方法：取雄性SD大鼠(四川省中医药科学院实验动物中心提供)60只,随机分为4组,每组15只：假手术组在膀胱外侧开一小口后直接缝合,未植入任何材料;其余3组在膀胱外侧开一小口后分别植入聚氨酯输尿管支架(对照组)、聚(L-丙交酯-ε-己内酯)/8%交联聚乙烯吡咯烷酮输尿管支架(实验1组)、聚(L-丙交酯-ε-己内酯)/5%交联聚乙烯吡咯烷酮输尿管支架(实验2组),随后缝合切口。术后4,8,16周,大体观察膀胱局部解剖情况,苏木精-伊红染色观察各组埋植材料的组织相容性。实验经四川大学华西公共卫生学院分析测试中心实验动物伦理学委员会批准。 结果与结论：①大体观察：术后4,8,16周时,对照组、实验1组均出现不同程度的慢性炎症刺激反应,实验2组仅术后4周时出现慢性炎症刺激反应,对照组、实验1组术后4,16周的材料结石生成率高于假手术组(P < 0.05),3组术后8周的材料结石生成率比较差异无显著性意义(P > 0.05);实验2组仅术后4周的材料结石生成率高于假手术组,其余时间点比较差异无显著性意义(P > 0.05);②病理观察：术后各时间点,对照组、实验1组、实验2组均出现不同程度外膜异物、炎症反应及黏膜弥漫增生,3组间术后不同时间点的黏膜弥漫增生率比较差异无显著性意义(P > 0.05),但均高于假手术组(P < 0.05);③结果表明：聚(L-丙交酯-ε-己内酯)/交联聚乙烯吡咯烷酮输尿管支架的结石生成情况和膀胱组织学反应与商品聚氨酯输尿管支架管相当,尤以加入5%交联聚乙烯吡咯烷酮配比的组织相容性较优。 ORCID: 0000-0003-3251-0657(唐萌萌) 中国组织工程研究杂志出版内容重点：生物材料;骨生物材料; 口腔生物材料; 纳米材料; 缓释材料; 材料相容性;组织工程     

ε-己内酯/D，L-丙交酯共聚物的非等温结晶动力学研究

背景：ε-己内酯/D,L-丙交酯共聚物因具有良好的力学性能、降解性能以及生物相容性而受到广泛研究,但对其非等温结晶动力学研究相对较少。 目的：了解ε-己内酯/D,L-丙交酯共聚物的非等温结晶动力学性能。 方法：以实验室自制的ε-己内酯∶D,L-丙交酯共聚物90∶10为观察对象,采用示差扫描量热仪对其进行非等温测试,观察其结晶行为。 结果与结论：随着降温速率R的增加,PCDLA的结晶温度向低温方向移动,且Avrami指数均>3,以均相成核的三维球晶方式生长;Jeziorny法和莫志深法研究结果基本一致。     

聚已内酯的聚羟基丁酸酯—羟基戊酸酯共聚物的物理及降解特性

虽然各种ε-已内酯乳酸乙二醇共聚物曾经有过报道,但聚已内酯(PCL)和聚羟基丁酸酯(PHB)-羟基戊二酸酯(PHV)共聚物系列的物理混合未见报道。本文应用以PCL为代表,描述可生物降解聚合物的混合,改进PHB-PHV共聚物特性的混合技术,研究新材料的发展,采用12～20%PHV的PHB-PHV共聚物,平均分子量分别为350 000和300 000,PCL分子量54 500,平均分子量20 500,用常规的可溶铸造技     

具有S—型降解共聚(L—丙交酯/甘油酯)的药物释放系统的体内特性

为了对药物释放系统的研究,作者曾通过羟基酸和丙交酯在无催化剂的作用下直接缩聚合成系列生物可降解聚酯,平均分子量小于10000的低分子聚合物,处理易变形,载体与药物易混合,聚合物降解易控制。目前作者研究发现L-丙交酯与甘油酯高分子共聚物可作为一种可降解性材料,平均分子量为16900～41300。通过具有催化剂存在的开环聚合作用而制备,表明体内降解产生明显的S-型降解模型,而具有高分子量的生物可降解S-型聚合     

Schizophrenia in a North Swedish geographical isolate, 1900–1977. Epidemiology, genetics and biochemistry

Over 200 schizophrenic patients belonging to three major and interrelated pedigree complexes have been investigated over the past 30 years in a North Swedish geographically isolated population, presently numbering about 6,000. An intensive investigation of a number of biochemical correlates and genetic markers in a few selected families belonging to one of the major pedigrees has indicated new strategies for the current research program.
Schizophrenia, as defined operationally, is significantly associated with decreased activities of two enzymes (1) blood platelet monoamine oxidase, (2) plasma dopamine-β-hydroxylase, and (3) with the genetic marker Gc² (group specific antigen). Both enzymes are subject to genetic variation. A positive score for linkage between schizophrenia and low plasma DBH activity has been calculated, but, so far, available data are insufficient for discrimination between linkage and partial contribution of genetically controlled low plasma DBH to the pathogenesis of the disease. Alternatively, both mechanisms could be involved.
As a model for continued research, schizophrenia is explained as based on a double dominant-recessive genotype (Aabb), representing a vulnerability which in about 50 % of cases develops into clinical schizophrenia. It is suggested that the dominant mutation (A) operates on or affects MAO activity, and that the recessive genotype (bb) is instrumental in low variates of DBH activity and very likely such variates within the normal range of physiological variation. Moreover, it is suggested that the combined effects of MAO- and DBH-reduced efficiency on the metabolism of e.g. dopamine could be an essential pathogenic mechanism for the schizophrenic illness which is segregating in this population.     

Renal dysplasia and asplenia in two sibs

A family is reported in which two sibs, one male and the other female, both died within 24 hours of birth with enlarged polycystic kidneys. Postmortem histology in the second child showed gross renal dysplasia. In both children the pancreas was enlarged, nodular and cystic but the liver appeared macroscopically normal. In the second child, histological examination confirmed pancreatic fibrosis with cystic dilation of ducts, but showed portal fibrosis with bile duct proliferation in the liver.
This combination of findings is very reminiscent of those in a girl and her brother reported by Ivemark et al. (1959). The children reported here also showed absence or hypoplasia of the spleen, cardiac anomalies and other features of the Ivemark syndrome (Ivemark 1955), a quite different, usually sporadic, congenital disorder. It is suggested that the children described here have a distinct lethal congenital disorder, probably inherited in an autosomal recessive manner.     

The dominant diseases of modernized societies as omega-3 essential fatty acid deficiency syndrome: Substrate beriberi

About 1900, modern food selection and processing caused widespread $\text{epidemics}$ of the B vitamin deficiency diseases of beriberi and pellagra which, for genetic reasons, often expressed as different diseases ranging from bowel and heart disease to dermatoses and psychoses. But the B vitamins merely help convert essential fatty acids (EFA) into the prostaglandin (PG) tissue regulators and it now turns out that, through hydrogenation, milling and selection of w3-poor southern foods, we have also been systematically depleting, by as much as 90%, a newly discovered trace Nordic EFA (w3) of special importance to primates and sole precursor of the PG3(4) series, even as a concurrent fiber deficiency increases body demand for EFA. Since substrate EFA is processed by many B vitamin catalysts, an EFA deficiency will mimic a $\text{panh}$ypovitaminosis B, i.e., a mixture of $\text{substrate}$ beriberi and $\text{substrate}$ pellagra resembling vitamin beriberi and pellagra but exhibiting as even more diverse $\text{endemic}$ disease. This would consitute a second stage of the Modern Malnutrition and explain why some workers now hold the dominant diseases of modermized societies to be new, nutritionally based, pellagraform yet lipid-related and to range, once again, from heart disease to psychosis. It is an assumption that our dominant diseases are unrelated to each other or are merely revealed by our diagnostic acumen and therapeutic success; and that hydrogenating millions of tons of food oils annually, to destroy the rancidity producing w3-EFA, is safe for $\text{primates}$. Extensive beriberiform disease is reported here in 32 typical cases taken from medical practice which responds strikingly to linseed oil supplements (60% w3-EFA) in confirmation of identical results in Capuchins.     

'Very sore nights and days': the child's experience of illness in early modern England, c.1580-1720

Sick children were ubiquitous in early modern England, and yet they have received very little attention from historians. Taking the elusive perspective of the child, this article explores the physical, emotional, and spiritual experience of illness in England between approximately 1580 and 1720. What was it like being ill and suffering pain? How did the young respond emotionally to the anticipation of death? It is argued that children’s experiences were characterised by profound ambivalence: illness could be terrifying and distressing, but also a source of emotional and spiritual fulfilment and joy. This interpretation challenges the common assumption amongst medical historians that the experiences of early modern patients were utterly miserable. It also sheds light on children’s emotional feelings for their parents, a subject often overlooked in the historiography of childhood. The primary sources used in this article include diaries, autobiographies, letters, the biographies of pious children, printed possession cases, doctors’ casebooks, and theological treatises concerning the afterlife.     

Guidelines for the Validation and Use of Immunoassays for Determination of Introduced Proteins in Biotechnology Enhanced Crops and Derived Food Ingredients

Recent advancements in agricultural biotechnology have created a need for analytical techniques to determine introduced proteins in crops enhanced through modern biotechnology techniques. These proteins are expressed in plant tissues and may be present in food ingredients. Immunoassays are ideally suited for protein detection and may be used as both quantitative and threshold methods. Microplate ELISA and lateral flow devices are two of the most commonly used immunoassay formats for agricultural biotechnology applications. This paper provides general background information and a discussion of criteria for the validation and application of immunochemical methods to the analysis of proteins introduced into plants and food ingredients using biotechnology methods. It is the result of a collaborative effort of members of the Analytical Environmental Immunochemical Consortium. This collaborative effort represents the combined expertise of several organizations to reach consensus on establishing guidelines for the validation and use of immunoassays. Further, the paper offers developers and users a consistent approach to adopting the technology as well as aid in producing accurate and meaningful results.     

HLA in North Colombia Chimila Amerindians

HLA-A,-B,-C,-DRB1 and -DQB1 alleles have been studied in Chimila Amerindians from Sabana de San Angel (North Colombian Coast) by using high resolution molecular typing. A frequent extended haplotype was found:HLA-A*24:02-B*51:10-C*15:02-BRB1*04:07-DQB1*03:02 (28.7%) which has also been described in Amerinndian Mayos Mexican population (Mexico, California Gulf, Pacific Ocean). Other haplotypes had already been found in Amerindians from Mexico (Pacific and Atlantic Coast), Peru (highlands and Amazon Basin), Bolivia and North USA. A geographic pattern according to HLA allele or haplotype frequencies is lacking in Amerindians, as already known. Also, five new extended haplotypes were found in Chimila Amerindians. Their HLA-A*24:02 high frequencies characteristic is shared with aboriginal populations of Taiwan; also, HLA-C*01:02 high frequencies are found in New Zealand Maoris, New Caledonians and Kimberly Aborigines from Australia. Finally, this study may show a model of evolutionary factors acting and rising one HLA allele frequency (-A*24:02), but not in others that belong to the same or different HLA loci.     

Ultracryotomy: development and application (with examples from the yeast cytology) (author's transl)

The preparation steps usually necessary for obtaining ultrathin frozen sections of biological material (chemical prefixation, enclosing, cryoprotective treatment, freezing, sectioning, and post-staining the sections for transmission electron microscopy) are submitted to a critical analysis. The application of cryo-ultramicrotomy, in particularly for cytochemical purposes, is reviewed. Fundamental considerations of chemical prefixation and poststaining are supported by examples from yeast cytology. Furthermore, the efficiency of the cryo-ultramicrotomy (electron optical resolution of ultrastructural details) is demonstrated on yeast cells and protoplasts.     

The universal muscular chamber. A basic unit of the genitourinary, cardiovascular, gastro-intestinal, skeletal, cutaneous, respiratory and other systems, endocameral hypertension; and spasm, the key to their idiopathic diseases and arthropathies

Starting with the integument, we see many organs are contractile sacs or multiples thereof, which tubes or bags constitute the major part of the entire body. Recognition of this basic unit and its characteristics sheds new light, individually and collectively, on many disorders previously considered unrelated. Muscular tears and perforations develop in the walls of these chambers, being no way peculiar to those organs, wherein, hydrochloric acid occurs. So, it is not necessary to explain the absence of excessive acid from patients who exhibit holes in the gastric, uterine, aortic, duodenal, rectal, pulmonary, retina, and other walls. Muscle, not acid is the great common factor relating idiopathic disorders in the gastrointestinal tract to each other and to similar diseases in other systems. When the units are linked together, the lesions tend to appear as arthropathies, i.e. at the joints. Rephrasing common-place observations, frees us from conventional, conceptual cul-de-sacs. An observation is only as good as its interpretation, so all possibilities must be considered, otherwise, we will remain blinded by our misconceptions.     

Der Einfluß von Nahrungsmitteln und Rauchen auf die klinisch-chemische Diagnostik von Phäochromozytom,Neuroblastom und Karzinoid-Syndrom

Zusammenfassung Der Einfluß von verschiedenen Nahrungsmitteln auf Methoden zur Bestimmung von Adrenalin (AD), Noradrenalin (NA), Vanillinmandelsäure (VMS), Metanephrinen (MN), Homovanillinsäure (HVS) und 5-Hydroxyindolessigsäure (5-HIE) im 24 h-Harn zur Diagnose des Phäochromozytoms bzw. Karzinoid-Syndroms wurde untersucht. Die in die Untersuchung einbezogenen Nahrungsmittel waren: Tee, Kaffee, Mandeln, Ananas, Käse, Walnüsse, Vanillepudding, Bananen, Tomaten und Milchschokolade. Außerdem wurde der Einfluß des Zigarettenrauchens auf die Bestimmung von AD, NA, VMS und MN untersucht.Walnüsse führten zu einer starken Erhöhung der 5-HIE-Ausscheidung. Bananen erhöhten die Ausscheidung von AD, NA, VMS, MN und 5-HIE. Kaffee und Ananas bewirkten eine geringe Zunahme der MN-Werte. Rauchen von 20–30 Zigaretten/Tag beeinflußte keine der vier Variablen.Wenn die beschriebenen Methoden benutzt werden, sollte lediglich auf den Verzehr von Bananen und Walnüssen vor und während der Harnsammelperioden verzichtet werden, da die oberen Normgrenzen im Harn überschritten werden könnten. Ein Verzicht auf Kaffee und Ananas in normalen Mengen ist nicht erforderlich. Es besteht kein Anlaß, weiterhin die bisherigen umfangreichen Restriktionen der übrigen Nahrungsmittel beizubehalten.