135 research outputs found

    Model Assessment of Alternatives for Reducing Seepage from Buried Uranium Mill Talings at the Morton Ranch Site in Central Wyoming

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    The purpose of this study is to examine potential ground water contamination by seepage from buried tailings under four alternatives of clay liners and tailings placement, which have been proposed for possible use at the Morton Ranch Site. To accomplish this comparison of alternatives, laboratory work and numerous measurements were made on materials typical of the Morton Ranch Site. These measurements provide the soil characteristics necessary for input to the hydrologic flow and transport models

    TRUST: A Computer Program for Variably Saturated Flow in Multidimensional, Deformable Media

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    The computer code, TRUST. provides a versatile tool to solve a wide spectrum of fluid flow problems arising in variably saturated deformable porous media. The governing equations express the conservation of fluid mass in an elemental volume that has a constant volume of solid. Deformation of the skeleton may be nonelastic. Permeability and compressibility coefficients may be nonlinearly related to effective stress. Relationships between permeability and saturation with pore water pressure in the unsaturated zone may include hysteresis. The code developed by T. N. Narasimhan grew out of the original TRUNP code written by A. L. Edwards. The code uses an integrated finite difference algorithm for numerically solving the governing equation. Narching in time is performed by a mixed explicit-implicit numerical procedure in which the time step is internally controlled. The time step control and related feature in the TRUST code provide an effective control of the potential numerical instabilities that can arise in the course of solving this difficult class of nonlinear boundary value problem. This document brings together the equations, theory, and users manual for the code as well as a sample case with input and output

    Heterozygous frameshift mutation in keratin 5 in a family with Galli-Galli disease

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    BACKGROUND: Reticulate pigmentary disorders include the rare autosomal dominant Galli–Galli disease (GGD) and Dowling–Degos disease (DDD). Clinical diagnosis between some of the subtypes can be difficult due to a degree of overlap between clinical features, therefore analysis at the molecular level may be necessary to confirm the diagnosis. OBJECTIVES: To identify the underlying genetic defect in a 48-year-old Asian-American woman with a clinical diagnosis of GGD. METHODS: Histological analysis was performed on a skin biopsy using haematoxylin–eosin staining. KRT5 (the gene encoding keratin 5) was amplified from genomic DNA and directly sequenced. RESULTS: The patient had a history of pruritus and hyperpigmented erythematous macules and thin papules along the flexor surfaces of her arms, her upper back and neck, axillae and inframammary areas. Hypopigmented macules were seen among the hyperpigmentation. A heterozygous 1-bp insertion mutation in KRT5 (c.38dupG; p.Ser14GlnfsTer3) was identified in the proband. This mutation occurs within the head domain of the keratin 5 protein leading to a frameshift and premature stop codon. CONCLUSIONS: From the histological findings and mutation analysis the individual was identified as having GGD due to haploinsufficiency of keratin 5

    Shape-sensing robotic-assisted bronchoscopy for pulmonary nodules: initial multicenter experience using the Ion™ Endoluminal System

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    BACKGROUND: Traditional bronchoscopy provides limited approach to peripheral nodules. Shape-sensing robotic-assisted bronchoscopy (SSRAB, Ion™ Endoluminal System) is a new tool for minimally invasive peripheral nodule biopsy. We sought to answer the research question: Does SSRAB facilitate sampling of pulmonary nodules during bronchoscopists\u27 initial experience? METHODS: The lead-in stage of a multicenter, single-arm, prospective evaluation of the Ion Endoluminal System (PRECIsE) is described. Enrolled subjects ≥ 18 years old had recent computed tomography evidence of one or more solid or semi-solid pulmonary nodules ≥ 1.0 to ≤ 3.5 cm in greatest dimension and in any part of the lung. Subjects were followed at 10- and 30-days post-procedure. This stage provided investigators and staff their first human experience with the SSRAB system; safety and procedure outcomes were analyzed descriptively. Neither diagnostic yield nor sensitivity for malignancy were assessed in this stage. Categorical variables are summarized by percentage; continuous variables are summarized by median/interquartile range (IQR). RESULTS: Sixty subjects were enrolled across 6 hospitals; 67 nodules were targeted for biopsy. Median axial, coronal and sagittal diameters were \u3c 18 mm with a largest cardinal diameter of 20.0 mm. Most nodules were extraluminal and distance from the outer edge of the nodule to the pleura or nearest fissure was 4.0 mm (IQR: 0.0, 15.0). Median bronchial generation count to the target location was 7.0 (IQR: 6.0, 8.0). Procedure duration (catheter-in to catheter-out) was 66.5 min (IQR: 50.0, 85.5). Distance from the catheter tip to the closest edge of the virtual nodule was 7.0 mm (IQR: 2.0, 12.0). Biopsy completion was 97.0%. No pneumothorax or airway bleeding of any grade was reported. CONCLUSIONS: Bronchoscopists leveraged the Ion SSRAB\u27s functionality to drive the catheter safely in close proximity of the virtual target and to obtain biopsies. This initial, multicenter experience is encouraging, suggesting that SSRAB may play a role in the management of pulmonary nodules. Clinical Trial Registration identifier and date NCT03893539; 28/03/2019

    Robot-assisted pelvic floor reconstructive surgery: an international Delphi study of expert users.

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    Robotic surgery has gained popularity for the reconstruction of pelvic floor defects. Nonetheless, there is no evidence that robot-assisted reconstructive surgery is either appropriate or superior to standard laparoscopy for the performance of pelvic floor reconstructive procedures or that it is sustainable. The aim of this project was to address the proper role of robotic pelvic floor reconstructive procedures using expert opinion. We set up an international, multidisciplinary group of 26 experts to participate in a Delphi process on robotics as applied to pelvic floor reconstructive surgery. The group comprised urogynecologists, urologists, and colorectal surgeons with long-term experience in the performance of pelvic floor reconstructive procedures and with the use of the robot, who were identified primarily based on peer-reviewed publications. Two rounds of the Delphi process were conducted. The first included 63 statements pertaining to surgeons' characteristics, general questions, indications, surgical technique, and future-oriented questions. A second round including 20 statements was used to reassess those statements where borderline agreement was obtained during the first round. The final step consisted of a face-to-face meeting with all participants to present and discuss the results of the analysis. The 26 experts agreed that robotics is a suitable indication for pelvic floor reconstructive surgery because of the significant technical advantages that it confers relative to standard laparoscopy. Experts considered these advantages particularly important for the execution of complex reconstructive procedures, although the benefits can be found also during less challenging cases. The experts considered the robot safe and effective for pelvic floor reconstruction and generally thought that the additional costs are offset by the increased surgical efficacy. Robotics is a suitable choice for pelvic reconstruction, but this Delphi initiative calls for more research to objectively assess the specific settings where robotic surgery would provide the most benefit

    Model-Based Deconvolution of Cell Cycle Time-Series Data Reveals Gene Expression Details at High Resolution

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    In both prokaryotic and eukaryotic cells, gene expression is regulated across the cell cycle to ensure “just-in-time” assembly of select cellular structures and molecular machines. However, present in all time-series gene expression measurements is variability that arises from both systematic error in the cell synchrony process and variance in the timing of cell division at the level of the single cell. Thus, gene or protein expression data collected from a population of synchronized cells is an inaccurate measure of what occurs in the average single-cell across a cell cycle. Here, we present a general computational method to extract “single-cell”-like information from population-level time-series expression data. This method removes the effects of 1) variance in growth rate and 2) variance in the physiological and developmental state of the cell. Moreover, this method represents an advance in the deconvolution of molecular expression data in its flexibility, minimal assumptions, and the use of a cross-validation analysis to determine the appropriate level of regularization. Applying our deconvolution algorithm to cell cycle gene expression data from the dimorphic bacterium Caulobacter crescentus, we recovered critical features of cell cycle regulation in essential genes, including ctrA and ftsZ, that were obscured in population-based measurements. In doing so, we highlight the problem with using population data alone to decipher cellular regulatory mechanisms and demonstrate how our deconvolution algorithm can be applied to produce a more realistic picture of temporal regulation in a cell

    DNA Adenine Methylation Is Required to Replicate Both Vibrio cholerae Chromosomes Once per Cell Cycle

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    DNA adenine methylation is widely used to control many DNA transactions, including replication. In Escherichia coli, methylation serves to silence newly synthesized (hemimethylated) sister origins. SeqA, a protein that binds to hemimethylated DNA, mediates the silencing, and this is necessary to restrict replication to once per cell cycle. The methylation, however, is not essential for replication initiation per se but appeared so when the origins (oriI and oriII) of the two Vibrio cholerae chromosomes were used to drive plasmid replication in E. coli. Here we show that, as in the case of E. coli, methylation is not essential for oriI when it drives chromosomal replication and is needed for once-per-cell-cycle replication in a SeqA-dependent fashion. We found that oriII also needs SeqA for once-per-cell-cycle replication and, additionally, full methylation for efficient initiator binding. The requirement for initiator binding might suffice to make methylation an essential function in V. cholerae. The structure of oriII suggests that it originated from a plasmid, but unlike plasmids, oriII makes use of methylation for once-per-cell-cycle replication, the norm for chromosomal but not plasmid replication

    Reprogramming of hepatic fat accumulation and 'browning' of adipose tissue by the short-chain fatty acid acetate

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    Background/Objectives: Short-chain fatty acids, produced by microbiome fermentation of carbohydrates, have been linked to a reduction in appetite, body weight and adiposity. However, determining the contribution of central and peripheral mechanisms to these effects has not been possible. Subjects/Methods:C57BL/6 mice fed with either normal or high-fat diet were treated with nanoparticle-delivered acetate, and the effects on metabolism were investigated. Results:In the liver, acetate decreased lipid accumulation and improved hepatic function, as well as increasing mitochondrial efficiency. In white adipose tissue, it inhibited lipolysis and induced 'browning', increasing thermogenic capacity that led to a reduction in body adiposity. Conclusions:This study provides novel insights into the peripheral mechanism of action of acetate, independent of central action, including ‘browning’ and enhancement of hepatic mitochondrial function
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