Nervous Necrosis Virus Replicates Following the Embryo Development and Dual Infection with Iridovirus at Juvenile Stage in Grouper

Infection of virus (such as nodavirus and iridovirus) and bacteria (such as Vibrio anguillarum) in farmed grouper has been widely reported and caused large economic losses to Taiwanese fish aquaculture industry since 1979. The multiplex assay was used to detect dual viral infection and showed that only nervous necrosis virus (NNV) can be detected till the end of experiments (100% mortality) once it appeared. In addition, iridovirus can be detected in a certain period of rearing. The results of real-time PCR and in situ PCR indicated that NNV, in fact, was not on the surface of the eggs but present in the embryo, which can continue to replicate during the embryo development. The virus may be vertically transmitted by packing into eggs during egg development (formation) or delivering into eggs by sperm during fertilization. The ozone treatment of eggs may fail to remove the virus, so a new strategy to prevent NNV is needed

An infrared integrated optic astronomical beam combiner for stellar interferometry at 3-4 microns

Integrated-optic, astronomical, two-beam and three-beam, interferometric combiners have been designed and fabricated for operation in the L band (3 - 4 microns) for the first time. The devices have been realized in titanium-indiffused, x-cut lithium niobate substrates, and on-chip electro-optic fringe scanning has been demonstrated. White light fringes were produced in the laboratory using the two-beam combiner integrated with an on-chip Y-splitter.Comment: This paper was published in Optics Express and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: http://www.opticsinfobase.org/oe. Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under la

Functional roles of arginine residues in mung bean vacuolar H+-pyrophosphatase

AbstractPlant vacuolar H+-translocating inorganic pyrophosphatase (V-PPase EC 3.6.1.1) utilizes inorganic pyrophosphate (PPi) as an energy source to generate a H+ gradient potential for the secondary transport of ions and metabolites across the vacuole membrane. In this study, functional roles of arginine residues in mung bean V-PPase were determined by site-directed mutagenesis. Alignment of amino-acid sequence of K+-dependent V-PPases from several organisms showed that 11 of all 15 arginine residues were highly conserved. Arginine residues were individually substituted by alanine residues to produce R→A-substituted V-PPases, which were then heterologously expressed in yeast. The characteristics of mutant variants were subsequently scrutinized. As a result, most R→A-substituted V-PPases exhibited similar enzymatic activities to the wild-type with exception that R242A, R523A, and R609A mutants markedly lost their abilities of PPi hydrolysis and associated H+-translocation. Moreover, mutation on these three arginines altered the optimal pH and significantly reduced K+-stimulation for enzymatic activities, implying a conformational change or a modification in enzymatic reaction upon substitution. In particular, R242A performed striking resistance to specific arginine-modifiers, 2,3-butanedione and phenylglyoxal, revealing that Arg242 is most likely the primary target residue for these two reagents. The mutation at Arg242 also removed F− inhibition that is presumably derived from the interfering in the formation of substrate complex Mg2+–PPi. Our results suggest accordingly that active pocket of V-PPase probably contains the essential Arg242 which is embedded in a more hydrophobic environment

Dual Targeted Extracellular Vesicles Regulate Oncogenic Genes in Advanced Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) tumours carry multiple gene mutations and respond poorly to treatments. There is currently an unmet need for drug carriers that can deliver multiple gene cargoes to target high solid tumour burden like PDAC. Here, we report a dual targeted extracellular vesicle (dtEV) carrying high loads of therapeutic RNA that effectively suppresses large PDAC tumours in mice. The EV surface contains a CD64 protein that has a tissue targeting peptide and a humanized monoclonal antibody. Cells sequentially transfected with plasmid DNAs encoding for the RNA and protein of interest by Transwell®-based asymmetric cell electroporation release abundant targeted EVs with high RNA loading. Together with a low dose chemotherapy drug, Gemcitabine, dtEVs suppress large orthotopic PANC-1 and patient derived xenograft tumours and metastasis in mice and extended animal survival. Our work presents a clinically accessible and scalable way to produce abundant EVs for delivering multiple gene cargoes to large solid tumours

Active Integrated Optic Devices for Sensing: Optical Rate Gyroscopes and Stellar Interferometers.

Integrated optical devices are free from the alignment and stability issues that bedevil bulk optical devices and systems. Integrated optical devices are now widely deployed in fiber optic telecommunication systems and as sensor components. This thesis is a theoretical and experimental study of two new integrated optical sensors - an integrated optic ring resonator gyroscope for measuring angular rotation rate and an integrated optic beam combiner for stellar interferometry. Although passive integrated optic ring resonators for gyroscopes have been previously reported, little work has been performed for active rings. The sensitivity of the gyroscope is limited by the propagation losses in the ring, and hence can be improved by the introduction of loss-compensating gain inside the ring. In this thesis the first active ring resonator for gyroscopic applications is designed, fabricated and characterized. A 1.6 cm diameter active ring resonator is fabricated in a neodymium-doped glass by silver ion exchange. The finesse of the ring resonator is measured and is observed to increase from approximately 11 to 250 when the neodymium ions inside the ring are optically pumped to produce gain. The ultimate sensitivity of a ring resonator gyroscope is shown from theoretical considerations to be fundamentally limited by the spontaneous emission noise generated within the gain medium. A closed form expression for this sensitivity is derived. Integrated optic beam combiners offer many advantages over conventional bulk optic implementations for astronomical imaging. To date, integrated optic beam combiners have only been demonstrated at operating wavelengths below 2 $mu$m. Operation in the mid-IR, however, is highly desirable. In this thesis an integrated optic beam combiner for stellar interferometry that operates in the mid-IR is demonstrated for the first time. The device is fabricated on a lithium niobate substrate for operation in the vicinity of 3.4 $mu$m. Using this device, white-light, mid-infrared, fringes, as well as electro-optic on-chip fringe scanning, is demonstrated in the laboratory. A theoretical design technique based on three coupled waveguides is developed to achieve fully achromatic, broadband, polarization-insensitive, lossless beam combining. This design may make it possible to achieve the very deep broadband nulls needed for exoplanet searching.Ph.D.Electrical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/77701/1/hkhsiao_1.pd

Multiband Subspace Tracking Speech Enhancement for In-Car Human Computer Speech Interaction

In this paper, a new subspace-based speech enhancement algorithm for in-car human computer speech interaction is presented. We first incorporate a perceptual filterbank which is derived from psycho-acoustic model with signal subspace approach to effectively suppress in-car noises of engine. Second, for real-time applications, a new subspace tracking algorithm is derived by modifying PASTd algorithm to solve the data dependent hazard of tacking algorithm. Six different types of in-car noises in TAICAR database are used in our evaluation. The experimental results demonstrate that our approach is superior to conventional subspace and spectral subtraction methods

Particulate matter and SARS-CoV-2: a possible model of COVID-19 transmission

Coronavirus disease 2019 (COVID-19), an acute respiratory disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has rapidly developed into a pandemic throughout the world. This disease is a highly infectious novel coronavirus and can affect people of all ages. Previous reports observed that particulate matter (PM) provided a platform for intermixing with viruses (i.e., influenza). However, the role of PM in SARS-CoV-2 transmission remains unclear. In this paper, we propose that PM plays a direct role as a “carrier” of SARS-CoV-2. SARS-CoV-2 is reported to have a high affinity for the angiotensin-converting enzyme 2 (ACE2) receptor. Indirectly, exposure to PM increases ACE2 expression in the lungs which facilitates SARS-CoV-2 viral adhesion. Thus, the high risk of SARS-CoV-2 in heavily polluted regions can be explained by upregulation of ACE2 caused by PM. PM could be both a direct and indirect transmission model for SARS-CoV-2 infection

Hemopericardium from right atrial laceration in a newborn

We report the case of a newborn who suffered right atrial laceration during delivery. To our knowledge, there has been no previous report of blunt injury causing right atrial laceration with hemopericardium complicated by cardiac tamponade in the perinatal period

Using cognitive affective interaction model to construct on-line game for creativity

[[abstract]]The paper constructed an online game for Creativity. The development of the game is based on the Cognitive Affective Interaction Model that was designed to help students develop the skills for divergent and creative thinking. First, we proposed a framework for designing creativity games. Then, an online game system is constructed with the strategies of teaching for creativity. We proved that the creativity of the learners can be improved by the proposed game-based learning system. Conclusively, game-based learning creates a new opportunity for creativity.

Investigation of the early stages of human γD-crystallin aggregation process

<p>Cataract, a major cause of visual impairment worldwide, is a common disease of the eye lens related to protein aggregation. Several factors including the exposure of ultraviolet irradiation and possibly acidic condition may induce the unfolding and subsequent aggregation of the crystallin proteins leading to crystalline lens opacification. Human γD-crystallin (HγDC), a 173 residue monomeric protein, abundant in the nucleus of the human eye lens, has been shown to aggregate and form amyloid fibrils under acidic conditions and that this aggregation route is thought to be a potential initiation pathway for the onset of age-related nuclear cataract. However, the underlying mechanism of fibril formation remains elusive. This report is aimed at examining the structural changes and possible amyloid fibril formation pathway of HγDC using molecular dynamics and molecular docking simulations. Our findings demonstrated that incubation of HγDC under the acidic condition redistributes the protein surface charges and affects the protein interaction with its surrounding solvent environment. This brings about a twist motion in the overall tertiary structure that gives rise to newly formed anti-parallel β-strands in the C-terminal flexible loop regions. The change in protein structural conformation also involves an alteration in specific salt-bridge interactions. Altogether, these findings revealed a plausible mechanism for amyloid fibril formation of HγDC that is important to the early stages of HγDC aggregation involved in cataractogenesis.</p