Hypothalamo-pituitary portal development in the ovine fetus

The ontogeny of the hypothalamo-pituitary portal system was studied in six ovine fetuses, 48-67 days of gestation (term = 147 days) after infusion of the vascular system with a silicone rubber compound. In all of these fetuses, a marked orange blush of silicone rubber could be seen, under the dissecting microscope, extending down the stalk from the hypothalamus to the pituitary. On microscopic examination, extensive and well-developed capillary connections between the median eminence, the pituitary stalk, and pituitary gland were seen in all fetuses. In an additional fetus, aged 45 days, which was not perfused with silicone rubber, portal capillary loops had penetrated the median eminence. These findings suggest that, in the ovine fetus, hypothalamic releasing factors can be transported directly via a portal vascular route to the pituitary gland as early as 45 days of gestation.     

A new approach in the design of electronic portal imaging devices for portal dosimetry in radiotherapy

A CCD-based EPID using new crystal-assembly X-ray (CAX) converters is investigated for radiotherapy dosimetry. The proposed EPID design consists in replacing the common phosphor X-ray converters of current CCD-based EPIDs with high-stopping-power CAX converters. A Test Imaging Device (TID), consisting of a 30-mm-thick CAX converter made of Bismuth Germanate (BGO), coupled to a highly sensitive CCD camera, was used to evaluate the accessible imaging and dosimetric performance of the proposed design. The system response to dose and its dependence on photon beam energy were investigated. The effects of ghosting, dose rate, field size and phantom thickness were evaluated as well. The same measurements were also performed with our clinically used aSi-EPID so that comparisons of performance could be directly inferred. The TID displayed no detectable ghosting or sensitivity to dose rate. Its response to MU exposure was found to be linear within about ±1%. The level of glare induced in the TID and the aSi-EPID were equivalent. The TID resolution was higher than that of the aSi-EPID on the axis, but was found to decrease with off-axis distance. Finally, the image quality, assessed on the basis of signal-to-noise ratio in low dose radiographs of the larynx of a patient, was higher for the TID. The imaging performance accessible with the TID proved to be satisfying and its dosimetric capability was found to be superior to that of the current aSi-EPID.     

Discussion on the surgery of portal hypertension

IN THE SURGICAL TREATMENT OF PORTAL HYPERTENSION, THREE PROBLEMS PRESENT: (1) mesenteric venous thrombosis, (2) haemorrhage from the alimentary tract, and (3) ascites.     

消化系统中的门脉系统

本文介绍了消化系统中的肝门脉系统、胆固门脉系统、小肠绒毛门脉系统系统、胰岛一外分泌门脉系统和唾液腺门脉系统的结构和功能。     

Electron cryotomography reveals the portal in the herpesvirus capsid

Herpes simplex virus type 1 is a human pathogen responsible for a range of illnesses from cold sores to encephalitis. The icosahedral capsid has a portal at one fivefold vertex which, by analogy to portal-containing phages, is believed to mediate genome entry and exit. We used electron cryotomography to determine the structure of capsids lacking pentons. The portal vertex appears different from pentons, being located partially inside the capsid shell, a position equivalent to that of bacteriophage portals. Such similarity in portal organization supports the idea of the evolutionary relatedness of these viruses.     

BESC knowledgebase public portal

The BioEnergy Science Center (BESC) is undertaking large experimental campaigns to understand the biosynthesis and biodegradation of biomass and to develop biofuel solutions. BESC is generating large volumes of diverse data, including genome sequences, omics data and assay results. The purpose of the BESC Knowledgebase is to serve as a centralized repository for experimentally generated data and to provide an integrated, interactive and user-friendly analysis framework. The Portal makes available tools for visualization, integration and analysis of data either produced by BESC or obtained from external resources. AVAILABILITY: http://besckb.ornl.gov.