Nghia Vo - Academia.edu (original) (raw)

Papers by Nghia Vo

Proceedings of the National Academy of Sciences

Solute transport in unsaturated porous materials is a complex process, which exhibits some distin... more Solute transport in unsaturated porous materials is a complex process, which exhibits some distinct features differentiating it from transport under saturated conditions. These features emerge mostly due to the different transport time scales at different regions of the flow network, which can be classified into flowing and stagnant regions, predominantly controlled by advection and diffusion, respectively. Under unsaturated conditions, the solute breakthrough curves show early arrivals and very long tails, and this type of transport is usually referred to as non-Fickian. This study directly characterizes transport through an unsaturated porous medium in three spatial dimensions at the resolution of 3.25 μm and the time resolution of 6 s. Using advanced high-speed, high-spatial resolution, synchrotron-based X-ray computed microtomography (sCT) we obtained detailed information on solute transport through a glass bead packing at different saturations. A large experimental dataset (&gt...

European Journal of Pharmacology

Natural Product Communications

Phytochemical investigation of the methanol extract of the rhizomes of Vietnamese Boesenbergia pa... more Phytochemical investigation of the methanol extract of the rhizomes of Vietnamese Boesenbergia pandurata resulted in the isolation of a new secondary metabolite named panduratin P (1). The structure of this compound was elucidated by NMR spectroscopic analysis. Compound 1 exhibited a mild activity against PANC-1 human pancreatic cancer cell lines in nutrient-deprived medium (NDM) with PC50 value of 55.9 μM.

Vascular Surgery

Abstract Arterial anomalies are rare causes of biliary obstruction and are usually secondary to a... more Abstract Arterial anomalies are rare causes of biliary obstruction and are usually secondary to aneurysmal dilation. This case report demonstrates radiographi cally how an aberrant artery can cause biliary colic with extrinsic encroachment and eventually lead to narcotic ...

Angewandte Chemie

† Electronic Supplementary Information (ESI) available: detailed experimental methods, in situ XR... more † Electronic Supplementary Information (ESI) available: detailed experimental methods, in situ XRD data, Pawley refinement results, Gualtieri and Sharp-Hancock plots, in situ pH and turbidity profile fits, rate constants, and SEM images.

Pediatric and Developmental Pathology

Advanced science (Weinheim, Baden-Wurttemberg, Germany), 2018

As the energy density of lithium-ion cells and batteries increases, controlling the outcomes of t... more As the energy density of lithium-ion cells and batteries increases, controlling the outcomes of thermal runaway becomes more challenging. If the high rate of gas generation during thermal runaway is not adequately vented, commercial cell designs can rupture and explode, presenting serious safety concerns. Here, ultra-high-speed synchrotron X-ray imaging is used at >20 000 frames per second to characterize the venting processes of six different 18650 cell designs undergoing thermal runaway. For the first time, the mechanisms that lead to the most catastrophic type of cell failure, rupture, and explosion are identified and elucidated in detail. The practical application of the technique is highlighted by evaluating a novel 18650 cell design with a second vent at the base, which is shown to avoid the critical stages that lead to rupture. The insights yielded in this study shed new light on battery failure and are expected to guide the development of safer commercial cell designs.

Investigative ophthalmology & visual science, 2017

Cerebrospinal fluid pressure (CSFp) changes are involved or implicated in various ocular conditio... more Cerebrospinal fluid pressure (CSFp) changes are involved or implicated in various ocular conditions including glaucoma, idiopathic intracranial hypertension, and visual impairment and intracranial pressure syndrome. However, little is known about the effects of CSFp on lamina cribrosa and retrolaminar neural tissue (RLNT) biomechanics, potentially important in these conditions. Our goal was to use an experimental approach to visualize and quantify the deformation of these tissues as CSFp increased. The posterior eye and RLNT of porcine eyes (n = 3) were imaged using synchrotron radiation phase-contrast micro-computed tomography (PC μCT) at an intraocular pressure of 15 mm Hg and CSFps of 4, 10, 20, and 30 mm Hg. Scans of each tissue region were acquired at each CSFp step and analyzed using digital volume correlation to determine 3-dimensional tissue deformations. Elevating CSFp increased the strain in the lamina cribrosa and RLNT of all three specimens, with the largest strains occu...

Scientific reports, Jan 6, 2017

Osteoporosis is characterised by trabecular bone loss resulting from increased osteoclast activat... more Osteoporosis is characterised by trabecular bone loss resulting from increased osteoclast activation and unbalanced coupling between resorption and formation, which induces a thinning of trabeculae and trabecular perforations. Bisphosphonates are the frontline therapy for osteoporosis, which act by reducing bone remodelling, and are thought to prevent perforations and maintain microstructure. However, bisphosphonates may oversuppress remodelling resulting in accumulation of microcracks. This paper aims to investigate the effect of bisphosphonate treatment on microstructure and mechanical strength. Assessment of microdamage within the trabecular bone core was performed using synchrotron X-ray micro-CT linked to image analysis software. Bone from bisphosphonate-treated fracture patients exhibited fewer perforations but more numerous and larger microcracks than both fracture and non-fracture controls. Furthermore, bisphosphonate-treated bone demonstrated reduced tensile strength and Yo...

$Research paper thumbnail of Refractory Iron Deficiency Anemia Treated with Endoscopic-assisted Embolization$

Journal of Pediatric Gastroenterology and Nutrition, 2016

Southern medical journal, 2015

This study documents the first six unplanned virtual review (VR) sessions conducted during the 20... more This study documents the first six unplanned virtual review (VR) sessions conducted during the 2012 hurricane season at the Agency for Healthcare Research and Quality and their effects on review outcomes. It also compares these VR sessions with five face-to-face (FF) sessions. In the first part of this study, six VR sessions are analyzed in terms of feasibility, reproducibility, and reviewers' responses to a questionnaire about VR. In the second part, the VR sessions are compared with five other FF meetings in terms of costs and duration per discussed application. Despite their technical novelty, all of the VR sessions have been successfully conducted to the satisfaction of reviewers and agency organizers. Special emphasis panel reviewers are more receptive to the new technology than study section reviewers: 75% versus 42%, respectively (P<0.05). Although the duration per discussed application is comparable to FF, the cost per reviewer is much lower for VR sessions than FF se...

Investigative ophthalmology & visual science, May 1, 2016

Scleral stiffening has been proposed as a treatment for glaucoma to protect the lamina cribrosa (... more Scleral stiffening has been proposed as a treatment for glaucoma to protect the lamina cribrosa (LC) from excessive intraocular pressure-induced deformation. Here we experimentally evaluated the effects of moderate stiffening of the peripapillary sclera on the deformation of the LC. An annular sponge, saturated with 1.25% glutaraldehyde, was applied to the external surface of the peripapillary sclera for 5 minutes to stiffen the sclera. Tissue deformation was quantified in two groups of porcine eyes, using digital image correlation (DIC) or computed tomography imaging and digital volume correlation (DVC). In group A (n = 14), eyes were subjected to inflation testing before and after scleral stiffening. Digital image correlation was used to measure scleral deformation and quantify the magnitude of scleral stiffening. In group B (n = 5), the optic nerve head region was imaged using synchrotron radiation phase-contrast microcomputed tomography (PC μCT) at an isotropic spatial resolutio...

Proceedings of the Royal Society B: Biological Sciences, 2016

Spiders are an important animal group, with a long history. Details of their origins remain limit... more Spiders are an important animal group, with a long history. Details of their origins remain limited, with little knowledge of their stem group, and no insights into the sequence of character acquisition during spider evolution. We describe a new fossil arachnid, Idmonarachne brasieri gen. et sp. nov. from the Late Carboniferous (Stephanian, ca 305-299 Ma) of Montceaules-Mines, France. It is three-dimensionally preserved within a siderite concretion, allowing both laboratory-and synchrotron-based phase-contrast computed tomography reconstruction. The latter is a first for siderite-hosted fossils and has allowed us to investigate fine anatomical details. Although distinctly spider-like in habitus, this remarkable fossil lacks a key diagnostic character of Araneae: spinnerets on the underside of the opisthosoma. It also lacks a flagelliform telson found in the recently recognized, spiderrelated, Devonian-Permian Uraraneida. Cladistic analysis resolves our new fossil as sister group to the spiders: the spider stem-group comprises the uraraneids and I. brasieri. While we are unable to demonstrate the presence of spigots in this fossil, the recovered phylogeny suggests the earliest character to evolve on the spider stem-group is the secretion of silk. This would have been followed by the loss of a flagelliform telson, and then the ability to spin silk using spinnerets. This last innovation defines the true spiders, significantly postdates the origins of silk, and may be a key to the group's success. The Montceau-les-Mines locality has previously yielded a mesothele spider (with spinnerets). Evidently, Late Palaeozoic spiders lived alongside Palaeozoic arachnid grades which approached the spider condition, but did not express the full suite of crown-group autapomorphies.

Vascular and Endovascular Surgery, 1990

Radiation injury is an uncommon but increasingly important cause of arterial insufficiency. Radia... more Radiation injury is an uncommon but increasingly important cause of arterial insufficiency. Radiation-in duced vascular compromise can threaten limbs once thought salvaged by radiotherapy in the course of treating neoplasms. Two cases of la tent arterial occlusion secondary to radiotherapy are reported. The alter ation of tissue architecture surround ing this type of arterial injury requires a different approach to vas cular repair afforded only by ex traanatomic bypass grafting.