210 research outputs found
Imaging through multimode fibres with physical prior
Imaging through perturbed multimode fibres based on deep learning has been
widely researched. However, existing methods mainly use target-speckle pairs in
different configurations. It is challenging to reconstruct targets without
trained networks. In this paper, we propose a physics-assisted, unsupervised,
learning-based fibre imaging scheme. The role of the physical prior is to
simplify the mapping relationship between the speckle pattern and the target
image, thereby reducing the computational complexity. The unsupervised network
learns target features according to the optimized direction provided by the
physical prior. Therefore, the reconstruction process of the online learning
only requires a few speckle patterns and unpaired targets. The proposed scheme
also increases the generalization ability of the learning-based method in
perturbed multimode fibres. Our scheme has the potential to extend the
application of multimode fibre imaging
Hyperspectral Image Super-Resolution via Dual-domain Network Based on Hybrid Convolution
Since the number of incident energies is limited, it is difficult to directly
acquire hyperspectral images (HSI) with high spatial resolution. Considering
the high dimensionality and correlation of HSI, super-resolution (SR) of HSI
remains a challenge in the absence of auxiliary high-resolution images.
Furthermore, it is very important to extract the spatial features effectively
and make full use of the spectral information. This paper proposes a novel HSI
super-resolution algorithm, termed dual-domain network based on hybrid
convolution (SRDNet). Specifically, a dual-domain network is designed to fully
exploit the spatial-spectral and frequency information among the hyper-spectral
data. To capture inter-spectral self-similarity, a self-attention learning
mechanism (HSL) is devised in the spatial domain. Meanwhile the pyramid
structure is applied to increase the acceptance field of attention, which
further reinforces the feature representation ability of the network. Moreover,
to further improve the perceptual quality of HSI, a frequency loss(HFL) is
introduced to optimize the model in the frequency domain. The dynamic weighting
mechanism drives the network to gradually refine the generated frequency and
excessive smoothing caused by spatial loss. Finally, In order to better fully
obtain the mapping relationship between high-resolution space and
low-resolution space, a hybrid module of 2D and 3D units with progressive
upsampling strategy is utilized in our method. Experiments on a widely used
benchmark dataset illustrate that the proposed SRDNet method enhances the
texture information of HSI and is superior to state-of-the-art methods
Super-resolution imaging through a multimode fiber: the physical upsampling of speckle-driven
Following recent advancements in multimode fiber (MMF), miniaturization of
imaging endoscopes has proven crucial for minimally invasive surgery in vivo.
Recent progress enabled by super-resolution imaging methods with a data-driven
deep learning (DL) framework has balanced the relationship between the core
size and resolution. However, most of the DL approaches lack attention to the
physical properties of the speckle, which is crucial for reconciling the
relationship between the magnification of super-resolution imaging and the
quality of reconstruction quality. In the paper, we find that the
interferometric process of speckle formation is an essential basis for creating
DL models with super-resolution imaging. It physically realizes the upsampling
of low-resolution (LR) images and enhances the perceptual capabilities of the
models. The finding experimentally validates the role played by the physical
upsampling of speckle-driven, effectively complementing the lack of information
in data-driven. Experimentally, we break the restriction of the poor
reconstruction quality at great magnification by inputting the same size of the
speckle with the size of the high-resolution (HR) image to the model. The
guidance of our research for endoscopic imaging may accelerate the further
development of minimally invasive surgery
Effects of Autoionizing Resonances on Wave-Packet Dynamics Studied by Time-Resolved Photoelectron Spectroscopy
We Report a Combined Experimental and Theoretical Study on the Effect of Autoionizing Resonances in Time-Resolved Photoelectron Spectroscopy. the Coherent Excitation of N2 by ∼14.15 EV Extreme-Ultraviolet Photons Prepares a Superposition of Three Dominant Adjacent Vibrational Levels (V′=14-16) in the Valence B′ ςu+1 State, Which Are Probed by the Absorption of Two or Three Near-Infrared Photons (800 Nm). the Superposition Manifests itself as Coherent Oscillations in the Measured Photoelectron Spectra. a Quantum-Mechanical Simulation Confirms that Two Autoionizing Rydberg States Converging to the Excited a Π2u and B ςu+2 N2+ Cores Are Accessed by the Resonant Absorption of Near-Infrared Photons. We Show that These Resonances Apply Different Filters to the Observation of the Vibrational Wave Packet, Which Results in Different Phases and Amplitudes of the Oscillating Photoelectron Signal Depending on the Nature of the Autoionizing Resonance. This Work Clarifies the Importance of Resonances in Time-Resolved Photoelectron Spectroscopy and Particularly Reveals the Phase of Vibrational Quantum Beats as a Powerful Observable for Characterizing the Properties of Such Resonances
Disclosure of sexual orientation to health professionals in China: results from an online cross-sectional study: Tang W et al.
Background: Many men who have sex with men (MSM) in China are “in the closet.” The low rate of disclosure may impact sexual behaviours, testing for HIV and other sexually transmitted infections (STIs), and diseases transmission. This study examines factors associated with overall sexual orientation disclosure and disclosure to healthcare professionals
Comparing the effectiveness of a crowdsourced video and a social marketing video in promoting condom use among Chinese men who have sex with men: a study protocol
Crowdsourcing has been used to spur innovation and increase community engagement in public health programmes. Crowdsourcing is the process of giving individual tasks to a large group, often involving open contests and enabled through multisectoral partnerships. Here we describe one crowdsourced video intervention in which a video promoting condom use is produced through an open contest. The aim of this study is to determine whether a crowdsourced intervention is as effective as a social marketing intervention in promoting condom use among high-risk men who have sex with men (MSM) and transgender male-to-female (TG) in China
Antitumor Effects of Berberine on Gliomas via Inactivation of Caspase-1-Mediated IL-1β and IL-18 Release
Gliomas arise in the glial cells of the brain or spine and are the most prevalent and devastating type of brain tumors. Studies of tumor immunology have established the importance of the tumor micro-environment as a driver of oncogenesis. Inflammatory mediators such as IL-1β and IL-18 released by monocytes regulate transcriptional networks that are required for malignant cell growth. Berberine is a natural botanical alkaloid that is widely found in the Berberis species. Although it has been widely used as an anti-diarrheal treatment in North America for several decades, our study is the first to investigate berberine as an anti-tumor agent in glioma cells. In this study, we demonstrate that berberine significantly inhibits inflammatory cytokine Caspase-1 activation via ERK1/2 signaling and subsequent production of IL-1β and IL-18 by glioma cells. Moreover, we found that berberine treatment led to decreased motility and subsequently cell death in U251 and U87 cells. In addition, our study is the first to indicate that berberine can reverse the process of epithelial-mesenchymal transition, a marker of tumor invasion. Taken together, our work supports berberine as a putative anti-tumor agent targeting glioma cells
Faster and Riskier? Online Context of Sex Seeking Among Men Who Have Sex With Men in China.
BACKGROUND: Many men who have sex with men (MSM) seek sex partners online, creating barriers and opportunities for human immunodeficiency virus prevention. The purpose of this study was to examine the characteristics of MSM and the risks associated with seeking sex through websites, gay apps, and both platforms in China. METHODS: Data were collected through a cross-sectional online survey from September through October 2014 from 3 large gay Web portals. Sociodemographic information, sexual behaviors, and online sex seeking behaviors were measured. Multinomial logistic regression was performed to compare sexual risk behaviors among website users, gay app users, and men who used both platforms. RESULTS: Of the 1201 participants, 377 (31.4%) were website-only users, 487 (40.5%) were gay app-only users, and 337 (28.0%) were men who used both platforms. These 3 MSM subgroups have distinct sociodemographic characteristics. Overall, 57.6% of participants reported having engaged in condomless anal sex with their last male partner in the past 6 months, but there was no significant difference in condomless sex between the 3 groups. Men who used both platforms viewed more sexually transmitted disease-related messages than website-only users (adjusted odds ratio, 2.19; 95% confidence interval, 1.57-3.05). CONCLUSIONS: Condom usage behaviors were unaffected by the medium through which sexual partners were found. However, the high frequency of condomless sex suggests that websites and gay apps are both risk environments. This study suggests using multiple platforms for human immunodeficiency virus/sexually transmitted disease social media interventions may be useful
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Agreement between reconstructed and modeled boreal precipitation of the Last Interglacial
The last extended time period when climate may have been warmer than today was during the Last Interglacial (LIG; ca. 129 to 120 thousand years ago). However, a global view of LIG precipitation is lacking. Here, seven new LIG climate models are compared to the first global database of proxies for LIG precipitation. In this way, models are assessed in their ability to capture important hydroclimatic processes during a different climate. The models can reproduce the proxy-based positive precipitation anomalies from the preindustrial period over much of the boreal continents. Over the Southern Hemisphere, proxy-model agreement is partial. In models, LIG boreal monsoons have 42% wider area than in the preindustrial and produce 55% more precipitation and 50% more extreme precipitation. Austral monsoons are weaker. The mechanisms behind these changes are consistent with stronger summer radiative forcing over boreal high latitudes and with the associated higher temperatures during the LIG
HIV self-testing among men who have sex with men in China: a qualitative implementation research study.
BACKGROUND: HIV self-testing (HIVST) may expand HIV testing, but there have been few pilot programmes among men who have sex with men (MSM). This purpose of this study was to evaluate HIVST implementation among MSM in China using qualitative methods. METHODS: We undertook semistructured interviews among MSM and those organising HIVST programmes for MSM. Purposive sampling method was used to ensure men with different HIV serostatuses, ages and HIVST frequencies were included. Men were recruited from MSM community-based organisations and a local HIV clinic. An implementation science framework was used to interpret the findings. Two individuals used a standard code-based methodology to identify themes. RESULTS: Forty-two MSM and six stakeholders were interviewed. Our data showed many MSM and stakeholders preferred HIVST to facility-based testing. Most men reported that HIVST empowered MSM and informed sexual decision making. Many men noted that decreasing the HIVST price may increase demand. Some men noted that HIVST could be scaled up through social media and by modifying bulky packaging. Minimal adverse events were reported. CONCLUSIONS: HIVST may expand HIV testing and promote empowerment of MSM. Minimal adverse outcomes were noted, but further implementation research is needed
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