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

Controlling electron motion with attosecond precision by shaped femtosecond intense laser pulse

We propose the scheme of temporal double-slit interferometer to precisely measure the electric field of shaped intense femtosecond laser pulse directly, and apply it to control the electron tunneling wave packets in attosecond precision. By manipulating the spectra phase of the input femtosecond pulse in frequency domain, one single pulse is split into two sub-pulses whose waveform can be precisely controlled by adjusting the spectra phase. When the shaped pulse interacts with atoms, the two sub-pulses are analogous to the Young's double-slit in time domain. The interference pattern in the photoelectron momentum distribution can be used to precisely retrieve the peak electric field and the time delay between two sub-pulses. Based on the precise characterization of the shaped pulse, we demonstrate that the sub-cycle dynamics of electron can be controlled with attosecond precision. The above scheme is proved to be feasible by both quantum-trajectory Monte Carlo simulations and numerical solutions of three-dimensional time-dependent Schr\"{o}dinger equation.Comment: 10 pages,4 figure

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

MSM Behavior Disclosure Networks and HIV Testing: An Egocentric Network Analysis Among MSM in China.

Men who have sex with men (MSM) disclose same-sex behaviors with others, creating disclosure networks. This study examined the characteristics of disclosure networks that are associated with HIV testing among MSM in China through an online nationwide survey. Name-generator questions were used to ask each participant ("ego") to nominate up to five social network members ("alters") with whom he had disclosed same-sex behaviors. Among the 806 men, the average disclosure network size was 4.05. MSM who reported larger disclosure networks were more likely to have been tested for HIV (aOR 1.21, 95% CI 1.08-1.34). The most common disclosure network alters were friends (45.1%), followed by sex partners (18.7%) and healthcare professionals (2.5%). Men who disclosed to healthcare professionals were more likely to test for HIV compared to men who disclosed to family members (aOR 5.43, 95% CI 2.11-14.04). Our findings can inform disclosure network-based interventions to promote MSM HIV testing

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

Transcriptional response of USP18 predicts treatment outcomes of interferon-alpha in HBeAg-positive chronic hepatitis B patientsefere.

Ubiquitin-specific protease 18 (USP18) is an important inhibitor of interferon (IFN) antiviral activity, and the aim of this study was to investigate the association between the USP18 mRNA level change in peripheral blood mononuclear cells (PBMCs) when stimulated with IFN in vitro before initiating treatment and the treatment outcomes in HBeAg-positive chronic hepatitis B (CHB) patients treated with IFN. A total of 44 patients who received standard IFN-based anti-HBV therapy and follow-up were enrolled in the study. The in vitro IFN-induced USP18 mRNA change (USP18IFN-N ) was measured via comparison of quantitative PCR-determined USP18 transcription levels of BPMCs cultured with and without IFN stimulation. Either for virological (VR) or serological response (SR), the baseline USP18IFN-N was significantly higher (P = 0.018 for VR, P = 0.008 for SR) among nonresponders (n = 23 for VR, n = 33 for SR) than that of responders (n = 21 for VR, n = 11 for SR). Multivariate analyses revealed baseline USP18IFN-N was a novel independent predictor for either VR (OR = 0.292, 95% CI = 0.102-0.835, P = 0.022) or SR (OR = 0.173, 95% CI = 0.035-0.849, P = 0.031) in our cohort. In addition, baseline USP18IFN-N in combination with HBV DNA loads or HBeAg levels showed improved accuracy of pretreatment prediction for VR or SR responders, respectively. Baseline USP18IFN-N levels are associated with both virological and serological response, and have the potential to become a clinical predictor for treatment outcomes in HBeAg-positive CHB patients before initiating IFN-α therapy

Idiopathic Male Infertility Is Strongly Associated with Aberrant Promoter Methylation of Methylenetetrahydrofolate Reductase (MTHFR)

Abnormal germline DNA methylation in males has been proposed as a possible mechanism compromising spermatogenesis of some men currently diagnosed with idiopathic infertility. Previous studies have been focused on imprinted genes with DNA methylation in poor quality human sperms. However, recent but limited data have revealed that sperm methylation abnormalities may involve large numbers of genes or shown that genes that are not imprinted are also affected.Using the methylation-specific polymerase chain reaction and bisulfite sequencing method, we examined methylation patterns of the promoter of methylenetetrahydrofolate reductase (MTHFR) gene (NG_013351: 1538-1719) in sperm DNA obtained from 94 idiopathic infertile men and 54 normal fertile controls. Subjects with idiopathic infertility were further divided into groups of normozoospermia and oligozoospermia. Overall, 45% (41/94) of idiopathic infertile males had MTHFR hypermethylation (both hemimethylation and full methylation), compared with 15% of fertile controls (P<0.05). Subjects with higher methylation level of MTHFR were more likely to have idiopathic male infertility (P-value for trend  = 0.0007). Comparing the two groups of idiopathic infertile subjects with different sperm concentrations, a higher methylation pattern was found in the group with oligozoospermia.Hypermethylation of the promoter of MTHFR gene in sperms is associated with idiopathic male infertility. The functional relevance of hypermathylation of MTHFR to male fertility warrants further investigation