2450MHz水冷式微波消融天线比吸收率的实验研究

探讨2450MHz微波天线比吸收率（SAR）的空间分布规律,以掌握微波天线的加热能力.以离体猪肝作为微波热消融实验对象,分别采用5组常用微波功率40W、50W、60W、70W和80W进行加热,每组以40例样本做热消融实验.实验中,每例样本被精确固定布放16个测温针并且分别进行前向和后向测温.结果 表明,SAR前、后向分布具有非对称性,从天线中心向四周有规律地衰减,并且SAR与加热功率之间没有线性关系,但数值随着加热功率增大而增大.近场点的温度模拟结果与实测值具有较好的一致性,从而验证了SAR检测结果的准确性.因此,该实验研究微波天线SAR分布的方法是有效的,SAR检测结果可用于温度场计算机模拟中的热载荷.     

水冷式微波天线热凝固离体猪肝的实验研究

微波辐射器的热场特性对肿瘤热疗有重要的实用意义,它直接决定了治疗肿瘤的尺寸和大小.本文通过水冷式微波天线在离体猪肝热消融的实验,研究其治疗区域的形态、温度分布等信息,将有助于临床参考.结果表明,水冷式微波天线沿径向方向的温度衰减快,能量主要集中在天线半径1cm以内;天线轴向上的温度分布由于有冷却水是非对称的,从而影响了凝固区的形状;增加加热时间会在一定程度上增加凝固范围.     

几种常见物理消融方法的动物实验研究

目的 探讨射频、微波、高频介导的热治疗(HITT)、激光等4种消融方法固化的凝固范围.方法 对离体猪肝在不同条件下应用4种消融方法进行固化,观察并记录剖面状况和凝固范围.将12只猪分成4组,亦采用4种消融方法,使用离体实验所用的相同条件固化在体猪肝,观察并记录剖面状况及凝固范围.结果 在体猪肝实验中射频组,电极针开放至3cm及5cm,消融时间分别为5.5、10 min时,凝固范围分别是2.12 cm×1.83 cm×2.07 cm、2.59 cm×2.19 cm×2.19 cm及4.57 cm×2.58 cm×2.61 cm及4.64 cm×2.70 cm×2.76 cm.微波组,微波功率为80W,消融时间分别是3、5、6、10 min时,凝固范围分别是2.53 cm×1.84 cm ×1.23 cm、2.74 cm×2.08 cm×1.62 cm、2.85 cm×2.09 cm×1.59 cm及3.38 cm×3.34 cm×1.77 cm.HITT组,消融时间分别是5及10 min,消融温度为85℃时凝固范围分别是2.53 cm×1.70 cm×0.90 cm及3.03 cm×2.07 cm×1.53 cm.激光组,采用单针凝固及4针耦合凝固,凝固范围在功率为2.0、2.5、10,0、12.0 W时分别是0.95 cm×1.05 cm×0.85 cm,1.05 cm×1.10cm×0.90 cm及2.45cm×1.45 cm×1.95 cm,2.55 cm×1.55cm×2.05 cm.离体猪肝实验中,4种方法的凝固范围均比相对应条件下在体猪肝的凝固范围有不同程度的增大.结论 通过对离体与在体猪肝的4种物理消融方法的实验研究,表明射频、微波及HITT凝固范围较大,其中射频消融效果更稳定,激光消融凝固范围较小,为临床治疗时物理消融方法的选择提供了技术参数.     

几种常见物理消融方法的动物实验研究

目的探讨射频、微波、高频介导的热治疗(HITT)、激光等4种消融方法固化的凝固范围。方法对离体猪肝在不同条件下应用4种消融方法进行固化,观察并记录剖面状况和凝固范围。将12只猪分成4组,亦采用4种消融方法,使用离体实验所用的相同条件固化在体猪肝,观察并记录剖面状况及凝固范围。结果在体猪肝实验中射频组,电极针开放至3cm及5cm,消融时间分别为5.5、10min时,凝固范围分别是2.12cm×1.83 cm×2.07cm、2.59cm×2.19cm×2.19cm及4.57 cm×2.58cm×2.61 cm及4.64cm×2.70cm×2.76cm。微波组,微波功率为80 W,消融时间分别是3、5、6、10 min时,凝固范围分别是2.53 cm×1.84 cm×1.23 cm、2.74cm×2.08cm×1.62cm、2.85cm×2.09cm×1.59cm及3.38cm×3.34cm×1.77cm。HITT组,消融时间分别是5及10min,消融温度为85℃时凝固范围分别是2.53 cm×1.70cm×0.90cm及3.03cm×2.07cm×1.53cm。激光组,采用单针凝固及4针耦合凝固,凝固范围在功率为2.0、2.5、10,0、12.0 W时分别是0.95cm×1.05cm×0.85cm,1.05cm×1.10cm×0.90cm及2.45cm×1.45cm×1.95cm,2.55cm×1.55cm×2.05cm。离体猪肝实验中,4种方法的凝固范围均比相对应条件下在体猪肝的凝固范围有不同程度的增大。结论通过对离体与在体猪肝的4种物理消融方法的实验研究,表明射频、微波及HITT凝固范围较大,其中射频消融效果更稳定,激光消融凝固范围较小,为临床治疗时物理消融方法的选择提供了技术参数。     

微波消融有效消融体积模型实验研究

针对微波消融治疗需要监测消融区域的温度变化状态和获取有效消融体积的问题,通过离体猪肝实验,分析了消融区域的温升规律并建立了微波消融有效消融体积的数学模型。共进行了112例离体猪肝实验,采用40~70 W的不同微波功率和300~600 s的不同作用时间进行微波消融。实验在70 W微波功率作用下,实时采集了距离微波消融针5、10、15、20 mm处的毁损区域温度,对采用不同微波功率和作用时间得到的有效消融区域的短径、长径及体积数据进行了分析,并利用1stopt软件进行拟合。结果显示,消融区域不同位置的升温速度不同,距离微波针5 mm位置的升温速度为20 mm处的10倍左右;得到了有效消融区域的短径、长径和体积有关微波功率和作用时间的离体组织数学模型。消融区域的温升状态监测和有效消融体积模型的建立,有助于优化微波消融的术前治疗计划和进行实时消融治疗的效果评估。     

基于热传导项的微波消融比吸收率检测方法

目的为提高微波消融温度场模拟的准确性,本文对微波天线比吸收率(specific absorption rate,SAR)检测新方法进行研究。方法以2450MHz水冷微波天线消融体模为研究对象,在Pennes生物传热方程的基础上,采用一种新的考虑热传导项的比吸收率SAR测量方法,推导出微波天线SAR,并采用有限元分析方法模拟微波消融温度场分布,通过与实验检测结果进行对比验证温度模拟的准确性。结果模拟温度与实测温度相吻合,最大温差2.71℃,平均温差0.73℃,一致性较高。结论通过考虑热传导项的比吸收率计算的新方法求解出SAR,可显著提高微波消融有限元温度模拟预测的准确性。     

离体骨的置入式微波消融

背景：微波高温可直接灭活骨肿瘤细胞,并且可维持骨的支架作用。 目的：探讨置入式微波对离体状态下正常骨组织的消融作用。 方法：采用微波消融治疗仪对新鲜离体猪骨干骺端进行消融,功率分别为60,70,80,90,100 W,消融时间300 s,微波频率2 450 MHz。刻度尺测量凝固区最长直径及最短直径;取凝固区标本,光镜及电镜观察其组织形态及超微结构。 结果与结论：置入式微波在不同功率下消融形态基本恒定,纵面上看类似一个椭球形,横面上看类似一个圆形,微波消融范围随着功率的增加明显增大,光镜下未见变化,电镜下可见经微波消融后的骨组织骨细胞核消失、空泡化,呈现完全坏死。说明置入式微波对离体状态下正常骨组织有消融作用。     

注射不同液体对微波消融温度场的离体实验研究

研究不同注射液体、注射量对于微波消融温度场的影响。在加热功率60 W、加热时间10 min的情况下,利用新型注射型微波天线进行消融离体肝脏的实验研究,并且于加热过程中分别注射生理盐水和无水乙醇液体,注射量依次为0、10、20 mL。根据测温针采集的温度数据,利用Matlab计算消融区域的范围(高于60℃区域)。通过对离体肝脏的消融面积、体积、横径和纵径的测量和统计,发现注射两种液体均可有效增大消融范围,与无液体注射相比面积增大率的范围在29.1%~72.0%之间,体积增加率在45.2%~141.8%之间;当注射液体体积由10 mL增加到20 mL时,生理盐水组的面积增加率为8.8%,无水乙醇组的面积增加率为28.8%。因此,联合液体注射可以扩大微波消融范围,并且随着注射体积的增加,消融范围扩大;微波联合无水乙醇的注射效果要略好于生理盐水。     

功能近红外光谱微波热疗疗效评估因子的研究

我们利用功能近红外光谱(fNIRs)技术进行肿瘤微波热消融实时组织参数测试,并探索一种新的实时疗效评估因子。选用新鲜离体猪肝作为实验标本,选用一定微波功率和时间组合进行热消融实验,利用fNIRs系统实时采集消融靶区特定位置的约化散射系数(μs’)和温度。μs’和温度随时间指数增长,测试点距微波消融针越近,μs’和温度上升越快,μs’达到一定的数值后趋于稳定,消融结束后处于稳定状态,和热消融结果比较可以确认μs’是一个较好的消融效果实时评估因子。光学参数μs’可以作为热消融的疗效评估因子,本研究将来为临床应用打下基础。     

单极子微波热疗天线在生物组织中产生的温度分布的调控

微波热疗的关键是实现微波能量长时间较均匀加热肿瘤组织。采用连续加热方法，在不改变天线结构及插入位置的条件下．很难实现对治疗区域的长时间均匀加热。我们结合电磁场的时域有限差分（Finite Difference Time Domain，FDTD）和温度场的有限差分方法模拟微波热疗天线在生物组织中产生的温度分布，通过调整天线的加热功率，并采用分时间隔加热的治疗方法，实现了微波能量对一定区域组织的长时间较均匀加热。     

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.     

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.     

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.     

What will studies of Fulani individuals naturally exposed to malaria teach us about protective immunity to malaria?

There are an estimated over 200 million yearly cases of malaria worldwide. Despite concerted international effort to combat the disease, it still causes approximately half a million deaths every year, the majority of which are young children with Plasmodium falciparum infection in sub-Saharan Africa. Successes are largely attributed to malaria prevention strategies, such as insecticide-treated mosquito nets and indoor spraying, as well as improved access to existing treatments. One important hurdle to new approaches for the treatment and prevention of malaria is our limited understanding of the biology of Plasmodium infection and its complex interaction with the immune system of its human host. Therefore, the elimination of malaria in Africa not only relies on existing tools to reduce malaria burden, but also requires fundamental research to develop innovative approaches. Here, we summarize our discoveries from investigations of ethnic groups of West Africa who have different susceptibility to malaria.     

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.     

'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.     

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.