120 research outputs found
Transformer-based Image Compression with Variable Image Quality Objectives
This paper presents a Transformer-based image compression system that allows
for a variable image quality objective according to the user's preference.
Optimizing a learned codec for different quality objectives leads to
reconstructed images with varying visual characteristics. Our method provides
the user with the flexibility to choose a trade-off between two image quality
objectives using a single, shared model. Motivated by the success of
prompt-tuning techniques, we introduce prompt tokens to condition our
Transformer-based autoencoder. These prompt tokens are generated adaptively
based on the user's preference and input image through learning a prompt
generation network. Extensive experiments on commonly used quality metrics
demonstrate the effectiveness of our method in adapting the encoding and/or
decoding processes to a variable quality objective. While offering the
additional flexibility, our proposed method performs comparably to the
single-objective methods in terms of rate-distortion performance
Transformer-based Variable-rate Image Compression with Region-of-interest Control
This paper proposes a transformer-based learned image compression system. It
is capable of achieving variable-rate compression with a single model while
supporting the region-of-interest (ROI) functionality. Inspired by prompt
tuning, we introduce prompt generation networks to condition the
transformer-based autoencoder of compression. Our prompt generation networks
generate content-adaptive tokens according to the input image, an ROI mask, and
a rate parameter. The separation of the ROI mask and the rate parameter allows
an intuitive way to achieve variable-rate and ROI coding simultaneously.
Extensive experiments validate the effectiveness of our proposed method and
confirm its superiority over the other competing methods.Comment: Accepted to IEEE ICIP 202
Device Integrity of Drug-eluting Depot Stent for Smart Drug Delivery
Atherosclerosis, or hardening of the arteries, is a condition in which plaque, made of cholesterol, fatty substances, cellular waste products, calcium, and fibrin, builds up inside the arteries. A metallic stent is a small mesh tube that is used to treat these narrowed arteries such as coronary artery diseases. The drug-eluting stent has a metallic stent platform coated with drug-polymer mix and has been shown to be superior to its metallic stent counterpart in reducing restenosis. In the past few years, a novel variation of the drug-eluting stent with micro-sized drug reservoirs (depot stent) has been introduced to the market. It allows smart programmable drug delivery with spatial/temporal control and has potential advantages over conventional stents. The drug-polymer mix compound can be altered from one reservoir to the next, allowing a highly-controlled release of different medications. For example, this depot stent concept can be applied in the renal indication for potential treatment of both renal artery stenosis (upstream) and its associated kidney diseases (downstream) simultaneously. However, the creation of such drug reservoirs on the stent struts inevitably compromises its mechanical integrity. In this study, the effects of these drug reservoirs on stent key clinical attributes were systematically investigated. We developed finite element models to predict the mechanical integrity of a balloon-expandable stent at various stages of its function life such as manufacturing and acute deployment, as well as the stent radial strength and chronic fatigue life. Simulation results show that (1) creating drug reservoirs on a stent strut could impact the stent fatigue resistance to certain degrees; (2) drug reservoirs on the high stress concentration regions led to much greater loss in all key clinical attributes than reservoirs on other locations; (3) reservoir shape change resulted in little differences in all key clinical attributes; and (4) for the same drug loading capacity, larger and fewer reservoirs yielded higher fatigue safety factor. These results can help future stent designers to achieve the optimal balance of stent mechanical integrity and smart drug delivery, thereby opening up a wide variety of new opportunities for disease treatments. We also proposed an optimized depot stent with tripled drug capacity and acceptable marginal trade-off in key clinical attributes when compared to the current drug-eluting stents. This depot stent prototype was manufactured for the demonstration of our design concept
TransTIC: Transferring Transformer-based Image Compression from Human Visualization to Machine Perception
This work aims for transferring a Transformer-based image compression codec
from human vision to machine perception without fine-tuning the codec. We
propose a transferable Transformer-based image compression framework, termed
TransTIC. Inspired by visual prompt tuning, we propose an instance-specific
prompt generator to inject instance-specific prompts to the encoder and
task-specific prompts to the decoder. Extensive experiments show that our
proposed method is capable of transferring the codec to various machine tasks
and outshining the competing methods significantly. To our best knowledge, this
work is the first attempt to utilize prompting on the low-level image
compression task
The dimer interface of the SARS coronavirus nucleocapsid protein adapts a porcine respiratory and reproductive syndrome virus-like structure
AbstractWe have employed NMR to investigate the structure of SARS coronavirus nucleocapsid protein dimer. We found that the secondary structure of the dimerization domain consists of five α helices and a β-hairpin. The dimer interface consists of a continuous four-stranded β-sheet superposed by two long α helices, reminiscent of that found in the nucleocapsid protein of porcine respiratory and reproductive syndrome virus. Extensive hydrogen bond formation between the two hairpins and hydrophobic interactions between the β-sheet and the α helices render the interface highly stable. Sequence alignment suggests that other coronavirus may share the same structural topology
Differentiating impacts of non‐pharmaceutical interventions on non‐coronavirus disease‐2019 respiratory viral infections: Hospital‐based retrospective observational study in Taiwan
Background
Physical distancing and facemask use are worldwide recognized as effective non-pharmaceutical interventions (NPIs) against the coronavirus disease-2019 (COVID-19). Since January 2020, Taiwan has introduced both NPIs but their effectiveness on non-COVID-19 respiratory viruses (NCRVs) remain underexplored.
Methods
This retrospective observational study examined electronic records at a tertiary hospital in northern Taiwan from pre-COVID (January–December 2019) to post-COVID period (January–May 2020). Patients with respiratory syndromes were tested for both enveloped (eg, influenza virus and seasonal coronavirus) and non-enveloped RVs (eg, enterovirus and rhinovirus) using multiplex reverse transcription polymerase chain reaction assays. Monthly positivity rates of NCRVs among adult and pediatric patients were analyzed with comparison between pre- and post-COVID periods.
Results
A total of 9693 patients underwent 12 127 multiplex RT-PCR tests. The average positivity rate of NCRVs reduced by 11.2% (25.6% to 14.4%) after nationwide PHIs. Despite the COVID-19 pandemic, the most commonly identified enveloped and non-enveloped viruses were influenza virus and enterovirus/rhinovirus, respectively. Observed reduction in NCRV incidence was predominantly contributed by enveloped NCRVs including influenza viruses. We did not observe epidemiological impacts of NPIs on non-enveloped viruses but an increasing trend in enterovirus/rhinovirus test positivity rate among pediatric patients. Our data were validated using Taiwan's national notification database.
Conclusions
Our frontline investigation suggests that the current NPIs in Taiwan might not effectively control the transmission of non-enveloped respiratory viruses, despite their protective effects against influenza and seasonal coronavirus. Health authorities may consider using hydrogen peroxide or chloride-based disinfectants as additional preventative strategies against non-enveloped respiratory viruses in the post-COVID-19 era
A CMOS-Compatible Poly-Si Nanowire Device with Hybrid Sensor/Memory Characteristics for System-on-Chip Applications
This paper reports a versatile nano-sensor technology using “top-down” poly-silicon nanowire field-effect transistors (FETs) in the conventional Complementary Metal-Oxide Semiconductor (CMOS)-compatible semiconductor process. The nanowire manufacturing technique reduced nanowire width scaling to 50 nm without use of extra lithography equipment, and exhibited superior device uniformity. These n type polysilicon nanowire FETs have positive pH sensitivity (100 mV/pH) and sensitive deoxyribonucleic acid (DNA) detection ability (100 pM) at normal system operation voltages. Specially designed oxide-nitride-oxide buried oxide nanowire realizes an electrically Vth-adjustable sensor to compensate device variation. These nanowire FETs also enable non-volatile memory application for a large and steady Vth adjustment window (>2 V Programming/Erasing window). The CMOS-compatible manufacturing technique of polysilicon nanowire FETs offers a possible solution for commercial System-on-Chip biosensor application, which enables portable physiology monitoring and in situ recording
Role of the CCAAT-Binding Protein NFY in SCA17 Pathogenesis
Spinocerebellar ataxia 17 (SCA17) is caused by expansion of the polyglutamine (polyQ) tract in human TATA-box binding protein (TBP) that is ubiquitously expressed in both central nervous system and peripheral tissues. The spectrum of SCA17 clinical presentation is broad. The precise pathogenic mechanism in SCA17 remains unclear. Previously proteomics study using a cellular model of SCA17 has revealed reduced expression of heat shock 70 kDa protein 5 (HSPA5) and heat shock 70 kDa protein 8 (HSPA8), suggesting that impaired protein folding may contribute to the cell dysfunction of SCA17 (Lee et al., 2009). In lymphoblastoid cells, HSPA5 and HSPA8 expression levels in cells with mutant TBP were also significantly lower than that of the control cells (Chen et al., 2010). As nuclear transcription factor Y (NFY) has been reported to regulate HSPA5 transcription, we focused on if NFY activity and HSPA5 expression in SCA17 cells are altered. Here, we show that TBP interacts with NFY subunit A (NFYA) in HEK-293 cells and NFYA incorporated into mutant TBP aggregates. In both HEK-293 and SH-SY5Y cells expressing TBP/Q61∼79, the level of soluble NFYA was significantly reduced. In vitro binding assay revealed that the interaction between TBP and NFYA is direct. HSPA5 luciferase reporter assay and endogenous HSPA5 expression analysis in NFYA cDNA and siRNA transfection cells further clarified the important role of NFYA in regulating HSPA5 transcription. In SCA17 cells, HSPA5 promoter activity was activated as a compensatory response before aggregate formation. NFYA dysfunction was indicated in SCA17 cells as HSPA5 promoter activity reduced along with TBP aggregate formation. Because essential roles of HSPA5 in protection from neuronal apoptosis have been shown in a mouse model, NFYA could be a target of mutant TBP in SCA17
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