Beam optics design of compact gantry for proton therapy

A new proton therapy facility for the treatment of deep-seated tumours is being assembled. The proton beam will be applied to the patient under computer control, using dynamic scanning of a focused proton pencil beam to produce a complete three-dimensional conformation of the dose to the target volume. The beam will be applied to the supine patient using a compact isocentric gantry for protons. By combining the scanning of the beam with the beam optics and by mounting the patient couch eccentrically on the gantry, the diameter of the rotating structure can be reduced to 4 m, which is the smallest diameter designed so far for a proton gantry. The paper describes the project especially from the point of view of the optics of the beam transport system of the gantry, including the beam line used to inject the beam into the gantry.     

正常直肠系膜横径的MRI解剖学研究

目的　基于核磁共振图像探讨正常成人直肠系膜横径及其影响因素。 方法　收集100例符合纳入标准的行盆腔MRI检查的成人临床资料进行回顾性分析。其中,男性42例,女性58例,年龄27~83岁。在轴位T1W1图像的精囊腺/子宫体层面上,测量直肠系膜最大横径、直肠最大横径、膀胱最大横径、双侧股骨头间距、前腹壁皮下脂肪厚度及女性子宫最大横径;对直肠系膜横径与其他测量指标之间的相关性进行统计学分析。 结果　（1）58例女性中,直肠系膜最大横径为（7.15±0.97）cm,子宫最大横径为（5.86±0.61）cm。直肠系膜横径与子宫横径无统计学相关性（P>0.05）。（2）合并男性、女性数据进行统计学分析。直肠系膜最大横径为（7.15±0.87）cm,直肠最大横径为（2.84±0.74）cm,膀胱最大横径为（8.58±1.66）cm,双侧股骨头间距为（12.79±0.96）cm,前腹壁皮下脂肪厚度为（2.01±0.76）cm。直肠系膜横径与性别、年龄以及膀胱横径无统计学相关性（P>0.05）;直肠系膜横径与前腹壁皮下脂肪厚度、直肠横径、双侧股骨头间距存在线性正相关（t=3.807、2.612、2.002,P<0.05）。以直肠系膜最大横径（Y）为应变量,前腹壁皮下脂肪厚度（X1）、直肠横径（X2）、双侧股骨头间距（X3）为自变量,得回归方程为：Y=3.500+0.389 X1+0.275 X2+0.163 X3,P<0.05,R2=0.522。 结论　直肠系膜横径与双侧股骨头间距、前腹壁皮下脂肪厚度及直肠横径有关。直肠系膜横径的观察和测量,可为直肠病变的诊疗提供影像学依据。     

小白鼠十二指肠发育分化的组织学和组织化学观察

用组织学和组织化学的方法观察了ＢＡＬＢ／Ｃ小鼠胚胎（Ｅｄ１４）至成年十二指肠的发育分化过程。结果如下：１．Ｅｄ１４￣１５，肠壁上皮细胞增殖并突间肠腔（原发腔），同时上皮内出现小腔隙（继发腔）。Ｅｄ１６￣１７，上皮表面纹状缘逐渐明显，间充质向上皮基底面突入，继发腔与原发腔相通，形成原始绒毛。Ｅｄ１９时，原始绒毛发育成指状绒毛。生后２周末，肠壁形态结构接近成年。２．生后１周末，可见潘氏细胞，所含颗粒较     

Épigénétique et pseudohypoparathyroïdies

Parental imprinting and the type of the genetic alteration play a determinant role in the phenotype expression of GNAS locus associated to pseudohypoparathyroidism (PHP). This imprint is tissue-specific, mainly localized in the kidney and the thyroid. Only the maternal allele is expressed at this level. An alteration in the coding sequence of the gene leads to an haplo-insufficiency and a dysmorphic phenotype (Albright's syndrome). If the alteration is on the maternal allele, there is a hormonal resistance to the PTH at the kidney level and to the TSH at the thyroid level. The phenotype is known as a PHP1a. If the alteration is on the paternal allele, there are few clinical signs with no hormonal resistance and the phenotype is known as pseudo-pseudo-hypoparathyroidism (PPHP). Methylation anomalies of GNAS locus, in particular of exon 1A, are responsible for a lack of expression of Gαs at kidney and thyroid levels only. If these anomalies concern the maternal allele (the only one expressed) with a paternal pattern, there is no haplo-insufficiency and no dysmorphic syndrome. The hormonal resistance is yet again limited to PTH and TSH. The phenotype is known as PHP1b. In the familial forms, these methylation anomalies are associated with a deletion of the syntaxine 16 gene in the maternal allele. This gene contains probably the imprinting center of the locus.     

Targeted brain hypothermia induced by an interstitial cooling device in human neck: theoretical analyses

In this study, the feasibility of a newly developed interstitial cooling device inserted into the neck muscle and placed on the surface of the common carotid artery is evaluated. A combination of vascular model and continuum model is developed to simulate the temperature fields in both the neck and brain regions. Parametric studies are conducted to test the sensitivity of various factors on the temperature distribution. It has been shown that the length of the device, temperature of the device, and the tissue gap between the device and the blood vessel are the dominant factors that determine the effectiveness of this cooling approach. Under the current design parameters, the device is capable of inducing a temperature drop of 2.8°C along the common carotid artery and it results in a total of 90 W of heat carried away from the arterial blood. Although the degree of the cooling in the arterial blood is inversely proportional to the blood flow rate of the arteries, the total heat loss from the arterial blood does not vary significantly if the blood flow rate changes during the cooling. After the cold arterial blood is supplied to the brain hemisphere, temperature reduction in the brain tissue is almost uniform and up to 3.1°C temperature drop is achieved within 1 hour. In addition to the possible benefits of brain hypothermia for stroke or head injury patients, the device has the potential to control fever as well as to improve patients’ outcome during open neck and head surgery.     

Pre- and postnatal development of catecholamine-containing and cholinesterase-positive nerves of the rat cornea and iris

Summary Glyoxylic acid-induced fluorescence technique and a copper thiocholine method were used to investigate the ontogenesis of the catecholamine-containing and cholinesterase-positive nerves of the rat iris and cornea.First fluorescent nerve fibres appeared in the iris on the 18th gestation day and in the cornea on the 19th day. A rapid increase in the density of the adrenergic nerve fibres of the iris continued to the age of three weeks, while the number of such fibres were small in the cornea.Acetylcholinesterase-positive fibres appeared both in the cornea and in the iris on the 19th gestation day. Their density increased more rapidly in the iris, especially in the sphincter muscle, than in the cornea.Non-specific cholinesterase activity was localized in the Schwann cells and the reaction was more intense during development than in the nerves of the cornea of adult rats.     

基于Sihler’s技术的踝和足背皮神经的整体分布模式研究

目的 揭示踝及足背皮神经的整体分布模式,为皮瓣移植感觉重建提供形态学指导。 方法 成年尸体24具,紧贴肌表面摘取含皮下脂肪的踝及足背皮肤,用改良的Sihler’s染色法显示并观察皮神经整体分布模式。 结果 在Sihler’s染色的标本中,肉眼可见隐神经支配踝前区（40.01±7.6）%、踝后区（30±6.7）%、以及部分足背内侧缘。腓浅神经支配踝前区（60.03±6.8）%,其足背内侧皮神经支配足背内侧区、第1、2趾背及第3趾背内侧半;95.83%的足背中间皮神经分布到第3趾背外侧半、第4、5趾背。腓肠神经支配踝后区（70±5.3）%,其足背外侧皮神经支配足背外侧缘皮肤。腓深神经分布到第1、2趾背相对面。初级神经支密度以踝前区最高,次级及以下神经支密度和总的神经支密度均以足背内侧区最高。 结论 在踝或足背的皮瓣移植中,建议把踝前区或足背内侧区设计为利于感觉重建的首选供区或感觉需求较高的受区。     

I. The Body in Psychoanalysis

The author offers a brief introduction to the theories of Armando Ferrari, highlighting his emphasis on the body, not only as mind's first object, but on the object out of which mind originates. He notes that this notion is the heir to Freud's preoccupation with finding the organic foundation of the mind in the body in which it is rooted, and in the idea of the drives as the expression of emergent psychic functions from the body, whereas instinct is the psychical representative of the stimulus originating from within the organism. Drives are not so much corporeal or psychic as defining the connection between the two realms. He suggests that this distinction became blurred with the tendentious translation of Trieb as ‘instinct’ and, later, as ‘emotion’, with the connotations of mental phenomena detached from the physical; while furthermore, the object relational stance, particularly as promulgated by Klein, suggested that such instincts could only be related to by the infant and become mind having been projected into the breast and then reintrojected. The infant's relationship with his body is thus mediated by the breast in Klein's model, rather than immediate and direct. Thus, whereas Freud always linked the psychosexual development of the infant directly with the emergence of physical desire arising from the erogenous zones, Klein linked the first fantasies (innate unconscious phantasy) with the infant's relationship with the maternal breast which now becomes the infant's first object, and emphasis is placed upon this object rather than on the subject of perception. Therapeutically, this necessitates that it also be placed on the transference. Bion moved away from this model with his emphasis on the proto‐mental in which physical and mental remain undifferentiated, so that distress from it as a source can be expressed in either; and in his idea of beta elements (sensational and affective) which are chronologically anterior to alpha elements and which can be employed for expression where alpha elements do not exist. The author concludes with a section on Ferrari whose bipartite model of mind arising out of body (as opposed to Winnicott's tripartite model which he discusses earlier in the paper) might be expressed in Bion's terms as one in which beta elements contain within themselves thecapacity to become alpha elements, while alpha function arise out of beta. Bion's shift from the object relations model to one based on the relation between sensation and affect on the one hand and mental function on the other entailed a shift away from insistent transference interpretation in favour of confronting the patient with his bodily self, a shift which Ferrari embraced and developed.     

Adaptation to stress enhances the resistance of the calcium pump in rat myocardial sarcoplasmic reticulum

The development of adaptation during stress is studied. At the early stages, adaptation exerts no protective effect: the activities of superoxide dismutase and catalase and the resistance and the Ca-transporting system of the myocardial sarcoplasmic reticulum to heat inactivation and high calcium concentrations decline. At the end of adaptation, superoxide dismutase and catalase activities increase, the function of the sarcoplasmic reticulum Catransporting system is improved, and the resistance of this system to high Ca concentrations increases compared with that in the control (1.4-fold) and during the early stages of adaptation (1.6-fold). The resistance to heat inactivation increased 1.5-fold compared with the control. Three days after the completion of adaptation, the activities of these enzymes and the resistance of Ca transport to heat inactivation and high Ca concentrations are lower than immediately after adaptation, but higher than in the control group and during the early adaptation period. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 123, No. 3, pp. 272–276, March, 1997     

The interpretation of kernels — An overview

The kernel identification method is a powerful technique for mathematically representing the dynamic behavior of a nonlinear system. This technique has been applied to a number of physical and physiological systems. An important development which has enhanced the usefulness of the kernel method has been the interpretation of the internal structure of a system by examining the shapes of the higher-degree kernels. Examples of various nonlinear models with known structure are illustrated to show a repertoire of kernel shapes. Variations in parameters of these models result in well-defined changes in the shapes of the kernels. Also, examples are shown of kernels obtained from physiological systems to demonstrate how examination of kernel shapes can lead to accurate predictions of the dynamic behavior of the physiological system. Finally, limitations of the applicable range of the kernel identification method are discussed.