Self-inspired learning for denoising live-cell super-resolution microscopy.

Every collected photon is precious in live-cell super-resolution (SR) microscopy. Here, we describe a data-efficient, deep learning-based denoising solution to improve diverse SR imaging modalities. The method, SN2N, is a Self-inspired Noise2Noise module with self-supervised data generation and self-constrained learning process. SN2N is fully competitive with supervised learning methods and circumvents the need for large training set and clean ground truth, requiring only a single noisy frame for training. We show that SN2N improves photon efficiency by one-to-two orders of magnitude and is compatible with multiple imaging modalities for volumetric, multicolor, time-lapse SR microscopy. We further integrated SN2N into different SR reconstruction algorithms to effectively mitigate image artifacts. We anticipate SN2N will enable improved live-SR imaging and inspire further advances.

Percutaneous recanalization in hepatic vein-type Budd-Chiari syndrome: hepatic or accessory hepatic vein.

PURPOSE: This study was designed to assess the clinical efficiency and long-term outcomes of hepatic vein (HV) and accessory hepatic vein (AHV) recanalization in patients with HV-type Budd-Chiari syndrome (BCS). MATERIAL AND METHODS: A total of 27 patients with HV-type BCS underwent AHV recanalization and 94 patients had HV recanalization at our center from January 2012 to December 2019. The treatment effectiveness and long-term outcomes were compared. RESULTS: Technical success was accomplished in all patients, without any procedure-related complications. The clinical success rates were 96.3% (26/27) and 95.7% (90/94) (p = 1.000). In the AHV and HV groups, re-obstruction was observed in 5 and 36 patients, respectively (p = 0.056). The median primary durations of AHV and HV patency were 64 and 49 months, respectively (p = 0.036), while the median secondary durations of AHV and HV patency were 70 and 64 months, respectively (p = 0.134). The median overall survival after AHV and HV recanalization was 73 and 78 months, respectively (p = 0.263). CONCLUSIONS: Our findings suggest that AHV could be employed as a replacement for HV, as a hepatic drainage vein, in HV-type BCS patients.

Space-variant Shack-Hartmann wavefront sensing based on affine transformation estimation.

The space-variant wavefront reconstruction problem inherently exists in deep tissue imaging. In this paper, we propose a framework of Shack-Hartmann wavefront space-variant sensing with extended source illumination. The space-variant wavefront is modeled as a four-dimensional function where two dimensions are in the spatial domain and two are in the Fourier domain with priors that both gently vary. Here, the affine transformation is used to characterize the wavefront space-variant function. Correspondingly, the zonal and modal methods are both escalated to adapt to four-dimensional representation and reconstruction. Experiments and simulations show double to quadruple improvements in space-variant wavefront reconstruction accuracy compared to the conventional space-invariant correlation method.

Fast whole-body motor neuron calcium imaging of freely moving Caenorhabditis elegans without coverslip pressed.

Caenorhabditis elegans (C. elegans) is an ideal model organism for studying neuronal functions at the system level. This article develops a customized system for whole-body motor neuron calcium imaging of freely moving C. elegans without the coverslip pressed. Firstly, we proposed a fast centerline localization algorithm that could deal with most topology-variant cases costing only 6 ms for one frame, not only benefits for real-time localization but also for post-analysis. Secondly, we implemented a full-time two-axis synchronized motion strategy by adaptively adjusting the motion parameters of two motors in every short-term motion step (~50 ms). Following the above motion tracking configuration, the tracking performance of our system has been demonstrated to completely support the high spatiotemporal resolution calcium imaging on whole-body motor neurons of wild-type (N2) worms as well as two mutants (unc-2, unc-9), even the instantaneous speed of worm moving without coverslip pressed was extremely up to 400 µm/s.

Structured illumination microscopy artefacts caused by illumination scattering.

Despite its wide application in live-cell super-resolution (SR) imaging, structured illumination microscopy (SIM) suffers from aberrations caused by various sources. Although artefacts generated from inaccurate reconstruction parameter estimation and noise amplification can be minimized, aberrations due to the scattering of excitation light on samples have rarely been investigated. In this paper, by simulating multiple subcellular structure with the distinct refractive index from water, we study how different thicknesses of this subcellular structure scatter incident light on its optical path of SIM excitation. Because aberrant interference light aggravates with the increase in sample thickness, the reconstruction of the 2D-SIM SR image degraded with the change of focus along the axial axis. Therefore, this work may guide the future development of algorithms to suppress SIM artefacts caused by scattering in thick samples. This article is part of the Theo Murphy meeting issue 'Super-resolution structured illumination microscopy (part 1)'.

Two-Photon Fluorescence Imaging.

Two-photon fluorescence imaging is a powerful tool for observing the dynamics of cells in vivo in intact tissue and is well suitable for imaging neuronal activity for neuroscience research. Due to the nonlinear two-photon absorption, the optical sectioning ability is inherent, resulting in two-photon images with high signal contrast and signal-to-noise ratio with efficient illumination. In addition, the longer wavelength excitation light in two-photon imaging compared to one-photon imaging suffers less scattering and absorption by tissue, which allows deeper penetration. Today, two-photon microscopy is being rapidly developed to adapt to various biological applications for high-speed, high-resolution, large-volume, long-term imaging in freely behaving animals.

Current-Density Regulating Lithium Metal Directional Deposition for Long Cycle-Life Li Metal Batteries.

Uncontrolled dendrite formation in the high energy density of lithium (Li) metal batteries (LMBs) may pose serious safety risks. While numerous studies have attempted to protect separators, these proposed methods fail to effectively inhibit upward dendrite growth that punctures through the separator. Here, we introduce a novel "orientated-growth" strategy that transfers the main depositional interface to the anode/current collector interface from the anode/separator interface. We placed a layer of cellulose/graphene carbon composite aerogel (CCA) between the current collector and the anode (LCL-bottom). This layer works as a charge organizer that induces a high current density and encourages Li to deposit at the anode/current collector interface. Both in situ and ex situ images of the electrode demonstrate that the anode part of the cell has been flipped; with the newly deposited particles facing the current collector and the smooth surface facing the separator. The electrode in half and full cells showed outstanding cyclic stability and rate capability, with the LCL-bottom/LFP full cell capable of maintaining 94 % of its initial capacity after 1000 cycles.

Upconversion Nanoparticles-Based Multiplex Protein Activation to Neuron Ablation for Locomotion Regulation.

The optogenetic neuron ablation approach enables noninvasive remote decoding of specific neuron function within a complex living organism in high spatiotemporal resolution. However, it suffers from shallow tissue penetration of visible light with low ablation efficiency. This study reports a upconversion nanoparticle (UCNP)-based multiplex proteins activation tool to ablate deep-tissue neurons for locomotion modulation. By optimizing the dopant contents and nanoarchitecure, over 300-fold enhancement of blue (450-470 nm) and red (590-610 nm) emissions from UCNPs is achieved upon 808 nm irradiation. Such emissions simultaneously activate mini singlet oxygen generator and Chrimson, leading to boosted near infrared (NIR) light-induced neuronal ablation efficiency due to the synergism between singlet oxygen generation and intracellular Ca2+ elevation. The loss of neurons severely inhibits reverse locomotion, revealing the instructive role of neurons in controlling motor activity. The deep penetrance NIR light makes the current system feasible for in vivo deep-tissue neuron elimination. The results not only provide a rapidly adoptable platform to efficient photoablate single- and multiple-cells, but also define the neural circuits underlying behavior, with potential for development of remote therapy in diseases.

Temporal multiplexing of the scientific grade camera for hyper-frame-rate imaging.

In order to maximize the spatio-temporal resolution of the scientific grade camera at width-limited ROI, this paper proposes a new hyper-frame-rate imaging method by temporal multiplexing the sub-region of the image sensor. In the system, a dual-axis scanning galvanometer is localized at the relay pupil plane and a high quality scan lens is utilized to form an image-side telecentric path. Following this path can overcome bandwidth waste in the conventional exposure and readout mode, and maintain other performances of image sensors. As a result, the sCMOS camera has performed 432fps over 820 × 700 pixel arrays to record the dynamic heartbeat of zebrafish larvae.

High cost-efficient and computational gigapixel video camera based on commercial lenses and CMOS chips.

The state-of-the-art commercial telephoto lens has already provided us almost one giga space-bandwidth product. Since the single-image sensor cannot take such sampling capacity, we implement a four-parallel-boresight imaging system by using four such lenses and use 64 image sensors to complete full field of view (FOV) imaging for achieving 0.8 gigapixel over 15.6°×10.5°. Multiple sensors mosaicking can make most online computation and data transfer in parallel, and help us to realize a gigapixel video camera. Meanwhile, according to the four-parallel-boresight configuration, the flat image plane simplifies the image registration and image stitching, and allows us to keep high imaging performance in full frame following geometric and optical calibration and correction. Furthermore, considering that working distance changes do bring additional x/y offsets between sensor arrays, we propose a computation-based method and introduce an eight-axis automatic motion mechanism into the system to perform the online active displacement. Our prototype camera using 16 sensors has been validated in 50 m indoor conditions and 145 m outdoor condition experiments, respectively. The effective angular resolution under the 0.2 giga 24 Hz video output is 18 µrad, which is two times the lens instantaneous FOV. Compared with other gigapixel cameras, it is superior in terms of optical system simplicity and cost efficiency, which would potentially benefit numerous unmanned aerial vehicle photogrammetric applications that pursue high angular resolution over moderate FOV.

Segmentation and classification of two-channel C. elegans nucleus-labeled fluorescence images.

BACKGROUND: Aging is characterized by a gradual breakdown of cellular structures. Nuclear abnormality is a hallmark of progeria in human. Analysis of age-dependent nuclear morphological changes in Caenorhabditis elegans is of great value to aging research, and this calls for an automatic image processing method that is suitable for both normal and abnormal structures. RESULTS: Our image processing method consists of nuclear segmentation, feature extraction and classification. First, taking up the challenges of defining individual nuclei with fuzzy boundaries or in a clump, we developed an accurate nuclear segmentation method using fused two-channel images with seed-based cluster splitting and k-means algorithm, and achieved a high precision against the manual segmentation results. Next, we extracted three groups of nuclear features, among which five features were selected by minimum Redundancy Maximum Relevance (mRMR) for classifiers. After comparing the classification performances of several popular techniques, we identified that Random Forest, which achieved a mean class accuracy (MCA) of 98.69%, was the best classifier for our data set. Lastly, we demonstrated the method with two quantitative analyses of C. elegans nuclei, which led to the discovery of two possible longevity indicators. CONCLUSIONS: We produced an automatic image processing method for two-channel C. elegans nucleus-labeled fluorescence images. It frees biologists from segmenting and classifying the nuclei manually.

[Early multi-disciplinary intervention reduces neurological disability in premature infants].

OBJECTIVE: This study aimed to evaluate the effectiveness of multi-disciplinary treatment approaches in reducing neurological disabilities in premature infants. METHODS: A total of 117 infants who were born premature in our hospital between March 2008 and February 2010 but had no congenital malformations and no severe neonatal complications, were enrolled in this study. They were randomly allocated to a multi-disciplinary treatment group (n=63) and a control group (n=54). While patients in the control group underwent an early conventional treatment, those in the multi-disciplinary treatment group were subjected to regular development monitoring, neurological examination and screening for brain injury, neuro-nutrition and neurodevelopment therapies, and rehabilitation training. RESULTS: The incidence rates of abnormalities in posture, reflex, sleep, muscle tone and EEG were significantly lower in the multi-disciplinary treatment group than in the control froup (P<0.05) at corrected postnatal ages of 6-12 months. At corrected postnatal ages of 6, 12, 18 and 24 months, both mental development index (MDI) and psychomotor development index (PDI) scores were significantly higher in the multi-disciplinary treatment group than in the control group (P<0.05). At corrected postnatal age of 3 years, incidence rates of cerebral palsy, language barrier, abnormal muscle tone and hearing impairment were significantly lower in the multi-disciplinary treatment group than in the control group (P<0.05). CONCLUSIONS: Early multi-disciplinary intervention approaches may significantly improve mental and motor developments and reduce the incidence of cerebral palsy-associated neurological disabilities in premature infants.

Molecular and immune pathobiology of human angiosarcoma.

Angiosarcoma is a rare endothelial-derived malignancy that is extremely diverse in anatomy, aetiology, molecular and immune characteristics. While novel therapeutic approaches incorporating targeted agents and immunotherapy have yielded significant improvements in patient outcomes across several cancers, their impact on angiosarcoma remains modest. Contributed by its heterogeneous nature, there is currently a lack of novel drug targets in this disease entity and no reliable biomarkers that predict response to conventional treatment. This review aims to examine the molecular and immune landscape of angiosarcoma in association with its aetiology, anatomical sites, prognosis and therapeutic options. We summarise current efforts to characterise angiosarcoma subtypes based on molecular and immune profiling. Finally, we highlight promising technologies such as single-cell spatial "omics" that may further our understanding of angiosarcoma and propose strategies that can be similarly applied for the study of other rare cancers.

Quantitatively mapping local quality of super-resolution microscopy by rolling Fourier ring correlation.

In fluorescence microscopy, computational algorithms have been developed to suppress noise, enhance contrast, and even enable super-resolution (SR). However, the local quality of the images may vary on multiple scales, and these differences can lead to misconceptions. Current mapping methods fail to finely estimate the local quality, challenging to associate the SR scale content. Here, we develop a rolling Fourier ring correlation (rFRC) method to evaluate the reconstruction uncertainties down to SR scale. To visually pinpoint regions with low reliability, a filtered rFRC is combined with a modified resolution-scaled error map (RSM), offering a comprehensive and concise map for further examination. We demonstrate their performances on various SR imaging modalities, and the resulting quantitative maps enable better SR images integrated from different reconstructions. Overall, we expect that our framework can become a routinely used tool for biologists in assessing their image datasets in general and inspire further advances in the rapidly developing field of computational imaging.

Escape steering by cholecystokinin peptidergic signaling.

Escape is an evolutionarily conserved and essential avoidance response. Considered to be innate, most studies on escape responses focused on hard-wired circuits. We report here that a neuropeptide NLP-18 and its cholecystokinin receptor CKR-1 enable the escape circuit to execute a full omega (Ω) turn. We demonstrate in vivo NLP-18 is mainly secreted by the gustatory sensory neuron (ASI) to activate CKR-1 in the head motor neuron (SMD) and the turn-initiating interneuron (AIB). Removal of NLP-18 or CKR-1 or specific knockdown of CKR-1 in SMD or AIB neurons leads to shallower turns, hence less robust escape steering. Consistently, elevation of head motor neuron (SMD)'s Ca2+ transients during escape steering is attenuated upon the removal of NLP-18 or CKR-1. In vitro, synthetic NLP-18 directly evokes CKR-1-dependent currents in oocytes and CKR-1-dependent Ca2+ transients in SMD. Thus, cholecystokinin peptidergic signaling modulates an escape circuit to generate robust escape steering.

Phase-locked constructing dynamic supramolecular ionic conductive elastomers with superior toughness, autonomous self-healing and recyclability.

Stretchable ionic conductors are considerable to be the most attractive candidate for next-generation flexible ionotronic devices. Nevertheless, high ionic conductivity, excellent mechanical properties, good self-healing capacity and recyclability are necessary but can be rarely satisfied in one material. Herein, we propose an ionic conductor design, dynamic supramolecular ionic conductive elastomers (DSICE), via phase-locked strategy, wherein locking soft phase polyether backbone conducts lithium-ion (Li+) transport and the combination of dynamic disulfide metathesis and stronger supramolecular quadruple hydrogen bonds in the hard domains contributes to the self-healing capacity and mechanical versatility. The dual-phase design performs its own functions and the conflict among ionic conductivity, self-healing capability, and mechanical compatibility can be thus defeated. The well-designed DSICE exhibits high ionic conductivity (3.77 × 10-3 S m-1 at 30 °C), high transparency (92.3%), superior stretchability (2615.17% elongation), strength (27.83 MPa) and toughness (164.36 MJ m-3), excellent self-healing capability (~99% at room temperature) and favorable recyclability. This work provides an interesting strategy for designing the advanced ionic conductors and offers promise for flexible ionotronic devices or solid-state batteries.

Highly flexible and superhydrophobic MOF nanosheet membrane for ultrafast alcohol-water separation.

High-performance pervaporation membranes have potential in industrial separation applications, but overcoming the permeability-selectivity trade-off is a challenge. We report a strategy to create highly flexible metal-organic framework nanosheet (MOF-NS) membranes with a faveolate structure on polymer substrates for alcohol-water separation. The controlled growth followed by a surface-coating method effectively produced flexible and defect-free superhydrophobic MOF-NS membranes. The reversible deformation of the flexible MOF-NS and the vertical interlamellar pathways were captured with electron microscopy. Molecular simulations confirmed the structure and revealed transport mechanism. The ultrafast transport channels in MOF-NS exhibited an ultrahigh flux and a separation factor of 8.9 in the pervaporation of 5 weight % ethanol-water at 40°C, which can be used for biofuel recovery. MOF-NS and polydimethylsiloxane synergistically contribute to the separation performance.

Sparse deconvolution improves the resolution of live-cell super-resolution fluorescence microscopy.

A main determinant of the spatial resolution of live-cell super-resolution (SR) microscopes is the maximum photon flux that can be collected. To further increase the effective resolution for a given photon flux, we take advantage of a priori knowledge about the sparsity and continuity of biological structures to develop a deconvolution algorithm that increases the resolution of SR microscopes nearly twofold. Our method, sparse structured illumination microscopy (Sparse-SIM), achieves ~60-nm resolution at a frame rate of up to 564 Hz, allowing it to resolve intricate structures, including small vesicular fusion pores, ring-shaped nuclear pores formed by nucleoporins and relative movements of inner and outer mitochondrial membranes in live cells. Sparse deconvolution can also be used to increase the three-dimensional resolution of spinning-disc confocal-based SIM, even at low signal-to-noise ratios, which allows four-color, three-dimensional live-cell SR imaging at ~90-nm resolution. Overall, sparse deconvolution will be useful to increase the spatiotemporal resolution of live-cell fluorescence microscopy.

[Study on between magnetic resonance venography and digital subtraction angiography on the inferior vena cava obstructive interface morphology of Budd-Chiari syndrome].

OBJECTIVE: To evaluate magnetic resonance venography (MRV) in diagnosing obstructive interface morphology of Budd-Chiari syndrome(BCS). METHODS: MRV examination was performed on 44 cases of BCS, and the images of obstructive interface morphology of the inferior vena cava were reviewed by two radiologists. RESULTS: In all 44 cases, there were 37 cases with complete obstruction and 7 with incomplete obstruction. MRV showed 4 cases with membrane with hole of incomplete obstruction. The morphologies MRV demonstrated that the proximal part of the 37 cases with complete obstruction were mainly divided into the cone type (36 cases) and the planum type (1 case). Besides, the type of distal end of obstruction were the cone type (30 cases), the planum type (4 cases) and the irregular type (3 cases). The overall sensitivity, specificity, positive and negative predictive values for the diagnosis of MRV were respectively 100%%, 57.1%, 92.5% and 100% as compared to the DSA. CONCLUSION: The examination of MRV is capable of revealing the obstructive interface morphology of the inferior vena cava, especially for the distal end of obstruction. MRV can provide guidelines in interventional treatment of Budd-Chiari syndrome.

[Clinical study on simvastatin treatment of pulmonary hypertension in patients with coal worker's pneumoconiosis].

OBJECTIVE: To observe simvastatin treatment of pulmonary hypertension in patients with coal workers pneumoconiosis (CWP). METHODS: 96 CWP patients with pulmonary hypertension were randomly divided into treatment and control groups. The control group was treated with 2.5 mg warfarin, once a day for four months; the treatment group was treated with 20 mg simvastatin, taken in evening, for 4 months. 6 min walking distance (6MWD) test and inspection pulmonary artery pressure were measured by echocardiography before and after treatment. RESULTS: In the treatment group, the 6MWD were (258 ± 26) m after treatment and (225 ± 19) m before treatment, respectively. Compared with control group, pulmonary artery pressure was (41 ± 9) mm Hg in the treatment group before treatment, (36 ± 3) mm Hg in the treatment group after treatment, and (39 ± 5) mm Hg in control group, respectively, the difference was statistically significant (P < 0.05). CONCLUSIONS: Simvastatin can improve pulmonary hypertension in coal workers pneumoconiosis, and shows a definite curative effect.