Publications by authors named "Oldham M"

Deformable 3D dosimeters have potential applications in validating deformable dose mapping algorithms. This study evaluates a novel deformable PRESAGE dosimeter and its application toward validating the deformable algorithm employed by VelocityAI. The deformable PRESAGE dosimeter exhibited a linear dose response with a sensitivity of 0.

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There is significant interest in delivering precisely targeted small-volume radiation treatments, in the pre-clinical setting, to study dose-volume relationships with tumor control and normal tissue damage. In this work we investigate the IGRT targeting accuracy of the XRad225Cx system from Precision x-Ray using high resolution 3D dosimetry techniques. Initial results revealed a significant targeting error of about 2.

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There is a pressing need for clinically intuitive quality assurance methods that report metrics of relevance to the likely impact on tumor control of normal tissue injury. This paper presents a preliminary investigation into the accuracy of a novel "transform method" which enables a clinically relevant analysis through dose-volume-histograms (DVHs) and dose overlays on the patient's CT data. The transform method was tested by inducing a series of known mechanical and delivery errors onto simulated 3D dosimetry measurements of six different head-and-neck IMRT treatment plans.

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Bright light therapy (BLT) is considered among the first-line treatments for seasonal affective disorder (SAD), yet a growing body of literature supports its use in other neuropsychiatric conditions including non-seasonal depression. Despite evidence of its antidepressant efficacy, clinical use of BLT remains highly variable internationally. In this article, we explore the autonomic effects of BLT and suggest that such effects may play a role in its antidepressant and chronotherapeutic properties.

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Musical hallucinations (MH) have been labeled Oliver Sacks syndrome, and in the majority of cases, they occur in the context of a hearing loss. In these instances, they have been described as auditory Charles Bonnet syndrome because they are thought to represent a cortical release phenomenon. Patients with MH tend to have intact reality testing, and as such, the condition may also be described as musical hallucinosis.

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Context: Historical work indicates that cigarette circumference may affect the toxicological profile of experimental cigarettes.

Objective: Studies were conducted to examine the effect of different cigarette circumferences on (1) selected mainstream smoke constituents including concentrations of tobacco specific nitrosamines (TSNA) in smoke and (2) mutagenicity and cytotoxicity of cigarette smoke condensate.

Materials And Methods: Analytical chemistry, Salmonella mutagenicity and cytotoxicity assays were used to evaluate the composition and biological activity of mainstream smoke from experimental, non-filtered cigarettes manufactured with four different circumferences (17.

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Context: Manufacture of cigarettes results in tobacco by-products, some of which can be processed and added back to cigarettes. Such additions (known as reconstituted tobacco or reconstituted leaf) have been shown to reduce tar yields. A new process (termed "Deli" cast sheet) is a potential refinement of the reconstitution process.

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Context: Recent technological advances allow ventilation holes in (or adjacent to) cigarette filters to be produced using lasers instead of using the mechanical procedures of earlier techniques.

Objective: Analytical chemistry can be used to compare the composition of mainstream smoke from experimental cigarettes having filters with mechanically produced ventilation holes to that of cigarettes with ventilation holes that were produced using laser technology.

Materials And Methods: Established procedures were used to analyze the smoke composition of 38 constituents of mainstream smoke generated using standard conditions.

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Context: Literature suggests that the width of tobacco strips in cigarettes may affect the smoke chemistry and toxicology of such products.

Objective: A comprehensive analysis of smoke from experimental cigarettes can be used to determine whether different cut widths of tobacco result in different toxicological activity.

Materials And Methods: A battery of tests was used to compare the chemistry and in vitro and in vivo toxicology of smoke from experimental cigarettes made with tobacco cut to different widths.

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Context: Cigarettes often have a small identifying mark (monogram) printed either on the cigarette paper toward the filter end of the cigarette or on the tipping paper.

Objective: A battery of tests was used to compare the toxicology of mainstream smoke from experimental cigarettes manufactured with different monogram inks. Cigarettes with different concentrations of different pigments were compared with cigarettes without ink, and with a control ink.

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Context: To comply with state requirements, cigarette manufacturers have added low-permeability bands to the cigarette paper. These bands can extinguish the cigarette when it is no longer being puffed by a smoker.

Objective: This study was conducted to evaluate the toxicology resulting from the addition of different types of bands to experimental cigarettes.

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Context: Adhesives are used in several different manufacturing operations in the production of cigarettes. The use of new, "high-speed-manufacture" adhesives (e.g.

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Context: In addition to tobacco and cigarette ingredients, there are many non-tobacco components and processes used to manufacture commercial cigarettes. Proposed cigarette components and manufacturing process changes were evaluated using a tiered toxicological testing program.

Objective: The toxicological testing and evaluation of proposed changes to selected non-tobacco cigarette components and manufacturing processes are described in this special report.

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Purpose: Recent trends in stereotactic radiosurgery use multifocal volumetric modulated arc therapy (VMAT) plans to simultaneously treat several distinct targets. Conventional verification often involves low resolution measurements in a single plane, a cylinder, or intersecting planes of diodes or ion chambers. This work presents an investigation into the consistency and reproducibility of this new treatment technique using a comprehensive commissioned high-resolution 3D dosimetry system (PRESAGE(®)∕Optical-CT).

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ATP-binding cassette (ABC) transporters are molecular pumps that harness the chemical energy of ATP hydrolysis to translocate solutes across the membrane. The substrates transported by different ABC transporters are diverse, ranging from small ions to large proteins. Although crystal structures of several ABC transporters are available, a structural basis for substrate recognition is still lacking.

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There is significant interest in delivering precisely targeted small-volume radiation treatments, in the pre-clinical setting, to study dose-volume relationships with tumour control and normal tissue damage. For these studies it is vital that image guidance systems and target positioning are accurately aligned (IGRT), in order to deliver dose precisely and accurately according to the treatment plan. In this work we investigate the IGRT targeting accuracy of the X-RAD 225 Cx system from Precision X-Ray using high-resolution 3D dosimetry techniques.

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Purpose: To introduce and evaluate a novel deformable 3-dimensional (3D) dosimetry system (Presage-Def/Optical-CT) and its application toward investigating the accuracy of dose deformation in a commercial deformable image registration (DIR) package.

Methods And Materials: Presage-Def is a new dosimetry material consisting of an elastic polyurethane matrix doped with radiochromic leuco dye. Radiologic and mechanical properties were characterized using standard techniques.

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Developmental regulation of gliogenesis in the mammalian CNS is incompletely understood, in part due to a limited repertoire of lineage-specific genes. We used Aldh1l1-GFP as a marker for gliogenic radial glia and later-stage precursors of developing astrocytes and performed gene expression profiling of these cells. We then used this dataset to identify candidate transcription factors that may serve as glial markers or regulators of glial fate.

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Efficient carbon utilization is critical to the survival of microorganisms in competitive environments. To optimize energy usage, bacteria have developed an integrated control system to preferentially uptake carbohydrates that support rapid growth. The availability of a preferred carbon source, such as glucose, represses the synthesis and activities of proteins necessary for the transport and metabolism of secondary carbon sources.

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Purpose: Achieving accurate optical-CT 3D dosimetry without the use of viscous refractive index (RI) matching fluids would greatly increase convenience.

Methods: Software has been developed to simulate optical-CT 3D dosimetry for a range of scanning configurations including parallel-beam, point, and converging light sources. For each configuration the efficacy of three refractive media was investigated: air, water, a fluid closely matched to PRESAGE(®), and perfect matching (RI = 1.

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Long noncoding RNAs (lncRNAs) have been described in cell lines and various whole tissues, but lncRNA analysis of development in vivo is limited. Here, we comprehensively analyze lncRNA expression for the adult mouse subventricular zone neural stem cell lineage. We utilize complementary genome-wide techniques including RNA-seq, RNA CaptureSeq, and ChIP-seq to associate specific lncRNAs with neural cell types, developmental processes, and human disease states.

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Article Synopsis
  • Proper neurological function relies on the precise regulation of the protein MeCP2, which is crucial in the human brain, especially during development.
  • The microRNA miR-483-5p, linked to the IGF2 gene, has been identified as a regulator of MeCP2 levels by targeting a specific region in the long 3' UTR of the MECP2 gene.
  • This study shows that higher levels of miR-483-5p are associated with lower levels of MeCP2 in developing brains, suggesting its potential in correcting abnormal neuron structures linked to MeCP2 overexpression.
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Stereotactic radiosurgery has become a widely used technique to treat solid tumors and secondary metastases of the brain. Multiple targets can be simultaneously treated with a single isocenter in order to reduce the set-up time to improve patient comfort and workflow. In this study, a 5-arc multifocal RapidArc treatment was delivered to multiple PRESAGE dosimeters in order to explore the repeatability of the treatment.

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Six base of skull IMRT treatment plans were delivered to 3D dosimeters within the RPC Head and Neck Phantom for QA verification. Isotropic 2mm 3D data was obtained using the DLOS-PRESAGE system and compared to an Eclipse (Varian) treatment plan. Normalized Dose Distribution pass rates were obtained for a number of criteria.

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We demonstrate a fluorescence lateral flow system that has excellent sensitivity and wide dynamic range. The illumination system utilizes an LED, plastic lenses and plastic and colored glass filters for the excitation and emission light. Images are collected on an iPhone 4.

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