896 research outputs found
Low temperature specific heat of vanadium carbide
Low temperature specific heat measurements on vanadium carbide crystal
Magnetic susceptibility of vanadium carbide
Magnetic susceptibility of vanadium carbide from 77 to 300 K measured by magnetomete
Lessons on Ethical Decision Making from the Bioscience Industry
Mackie and colleagues performed over 100 interviews with managers and executives at 13 bioscience companies to learn about bioindustry ethics from their perspective
Bipotential Adult Liver Progenitors Are Derived from Chronically Injured Mature Hepatocytes
SummaryAdult liver progenitor cells are biliary-like epithelial cells that emerge only under injury conditions in the periportal region of the liver. They exhibit phenotypes of both hepatocytes and bile ducts. However, their origin and their significance to injury repair remain unclear. Here, we used a chimeric lineage tracing system to demonstrate that hepatocytes contribute to the progenitor pool. RNA-sequencing, ultrastructural analysis, and inĀ vitro progenitor assays revealed that hepatocyte-derived progenitors were distinct from their biliary-derived counterparts. InĀ vivo lineage tracing and serial transplantation assays showed that hepatocyte-derived proliferative ducts retained a memory of their origin and differentiated back into hepatocytes upon cessation of injury. Similarly, human hepatocytes in chimeric mice also gave rise to biliary progenitors inĀ vivo. We conclude that human and mouse hepatocytes can undergo reversible ductal metaplasia in response to injury, expand as ducts, and subsequently contribute to restoration of the hepatocyte mass
Characterization of Pulmonary Metastases in Children With Hepatoblastoma Treated on Children\u27s Oncology Group Protocol AHEP0731 (The Treatment of Children With All Stages of Hepatoblastoma): A Report From the Children\u27s Oncology Group.
Purpose To determine whether the pattern of lung nodules in children with metastatic hepatoblastoma (HB) correlates with outcome. Methods Thirty-two patients with metastatic HB were enrolled on Children\u27s Oncology Group Protocol AHEP0731 and treated with vincristine and irinotecan (VI). Responders to VI received two additional cycles of VI intermixed with six cycles of cisplatin/fluorouracil/vincristine/doxorubicin (C5VD), and nonresponders received six cycles of C5VD alone. Patients were imaged after every two cycles and at the conclusion of therapy. All computed tomography scans and pathology reports were centrally reviewed, and information was collected regarding lung nodule number, size, laterality, timing of resolution, and pulmonary surgery. Results Among the 29 evaluable patients, only 31% met Response Evaluation Criteria in Solid Tumors (RECIST) for measurable metastatic disease. The presence of measurable disease by RECIST, the sum of nodule diameters greater than or equal to the cumulative cohort median size, bilateral disease, and ā„ 10 nodules were each associated with an increased risk for an event-free survival event ( P = .48, P = .08, P = .065, P = .03, respectively), with nodule number meeting statistical significance. Ten patients underwent pulmonary resection/metastasectomy at various time points, the benefit of which could not be determined because of small patient numbers. Conclusion Children with metastatic HB have a poor prognosis. Overall tumor burden may be an important prognostic factor for these patients. Lesions that fail to meet RECIST size criteria (ie, those \u3c 10 mm) at diagnosis may contain viable tumor, whereas residual lesions at the end of therapy may constitute eradicated tumor/scar tissue. Patients may benefit from risk stratification on the basis of the burden of lung metastatic disease at diagnosis
Sterols sense swelling in lipid bilayers
In the mimetic membrane system of phosphatidylcholine bilayers, thickening
(pre-critical behavior, anomalous swelling) of the bilayers is observed, in the
vicinity of the main transition, which is non-linear with temperature. The
sterols cholesterol and androsten are used as sensors in a time-resolved
simultaneous small- and wide angle x-ray diffraction study to investigate the
cause of the thickening. We observe precritical behavior in the pure lipid
system, as well as with sterol concentrations less than 15%. To describe the
precritical behavior we introduce a theory of precritical phenomena.The good
temperature resolution of the data shows that a theory of the influence of
fluctuations needs modification. The main cause of the critical behavior
appears to be a changing hydration of the bilayer.Comment: 11 pages, 7 ps figures included, to appear in Phys.Rev.
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