Inhibition of the RLR signaling pathway by SARS-CoV-2 ORF7b is mediated by MAVS and abrogated by ORF7b-homologous interfering peptide.

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and characterized by dysregulated immune response. Studies have shown that the SARS-CoV-2 accessory protein ORF7b induces host cell apoptosis through the tumor necrosis factor alpha (TNF-α) pathway and blocks the production of interferon beta (IFN-ß). The underlying mechanism remains to be investigated. In this study, we found that ORF7b facilitated viral infection and production, and inhibited the RIG-I-like receptor (RLR) signaling pathway through selectively interacting with mitochondrial antiviral-signaling protein (MAVS). MAVS439-466 region and MAVS Lys461 were essential for the physical association between MAVS and ORF7b, and the inhibition of the RLR signaling pathway by ORF7b. MAVSK461/K63 ubiquitination was essential for the RLR signaling regulated by the MAVS-ORF7b complex. ORF7b interfered with the recruitment of tumor necrosis factor receptor-related factor 6 (TRAF6) and the activation of the RLR signaling pathway by MAVS. Furthermore, interfering peptides targeting the ORF7b complex reversed the ORF7b-suppressed MAVS-RLR signaling pathway. The most potent interfering peptide V disrupts the formation of ORF7b tetramers, reverses the levels of the ORF7b-inhibited physical association between MAVS and TRAF6, leading to the suppression of viral growth and infection. Overall, this study provides a mechanism for the suppression of innate immunity by SARS-CoV-2 infection and the mechanism-based approach via interfering peptides to potentially prevent SARS-CoV-2 infection.IMPORTANCEThe pandemic coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and continues to be a threat to public health. It is imperative to understand the biology of SARS-CoV-2 infection and find approaches to prevent SARS-CoV-2 infection and ameliorate COVID-19. Multiple SARS-CoV-2 proteins are known to function on the innate immune response, but the underlying mechanism remains unknown. This study shows that ORF7b inhibits the RIG-I-like receptor (RLR) signaling pathway through the physical association between ORF7b and mitochondrial antiviral-signaling protein (MAVS), impairing the K63-linked MAVS polyubiquitination and its recruitment of tumor necrosis factor receptor-related factor 6 (TRAF6) to MAVS. The most potent interfering peptide V targeting the ORF7b-MAVS complex may reverse the suppression of the MAVS-mediated RLR signaling pathway by ORF7b and prevent viral infection and production. This study may provide new insights into the pathogenic mechanism of SARS-CoV-2 and a strategy to develop new drugs to prevent SARS-CoV-2 infection.

Elevation of cell-associated HIV-1 transcripts in CSF CD4+ T cells, despite effective antiretroviral therapy, is linked to brain injury.

Antiretroviral therapy (ART) can attain prolonged undetectable HIV-1 in plasma and cerebrospinal fluid (CSF), but brain injury remains prevalent in people living with HIV-1 infection (PLHIV). We investigated cell-associated (CA)-HIV-1 RNA transcripts in cells in CSF and blood, using the highly sensitive Double-R assay, together with proton Magnetic Resonance Spectroscopy (1H MRS) of major brain metabolites, in sixteen PLHIV. 14/16 CSF cell samples had quantifiable CA-HIV-1 RNA, at levels significantly higher than in their PBMCs (median 9,266 vs 185 copies /106 CD4+ T-cells; p<0.0001). In individual PLHIV, higher levels of HIV-1 transcripts in CSF cells were associated with greater brain injury in the frontal white matter (Std ß=-0.73; p=0.007) and posterior cingulate (Std ß=-0.61; p=0.03). 18-colour flow cytometry revealed that the CSF cells were 91% memory T-cells, equally CD4+ and CD8+ T-cells, but fewer B cells (0.4 %), and monocytes (3.1%). CXCR3+CD49d+integrin ß7-, CCR5+CD4+ T-cells were highly enriched in CSF, compared with PBMC (p <0.001). However, CA-HIV-1 RNA could not be detected in 10/16 preparations of highly purified monocytes from PBMC, and was extremely low in the other six. Our data show that elevated HIV-1 transcripts in CSF cells were associated with brain injury, despite suppressive ART. The cellular source is most likely memory CD4+ T cells from blood, rather than trafficking monocytes. Future research should focus on inhibitors of this transcription to reduce local production of potentially neurotoxic and inflammatory viral products.

DNA demethylation of promoter region orchestrates SPI-1-induced ADAMTS-5 expression in articular cartilage of osteoarthritis mice.

Osteoarthritis (OA) is one of the most prevalent joint diseases in aged people and characterized by articular cartilage degeneration, synovial inflammation, and abnormal bone remodeling. Recent advances in OA research have clearly shown that OA development is associated with aberrant DNA methylation status of many OA-related genes. As one of most important cartilage degrading proteases in OA, a disintegrin and metalloproteinase with thrombospondin motifs subtype 5 (ADAMTS-5) is activated to mediate cartilage degradation in human OA and experimental murine OA models. The pathological factors and signaling pathways mediating ADAMTS-5 activation during OA development are not well defined and have been a focus of intense research. ADAMTS-5 promoter is featured by CpG islands. So far there have been no reports concerning the DNA methylation status in ADAMTS-5 promoter during OA development. In this study, we sought to investigate DNA methylation status in ADAMTS-5 promoter, the role of DNA methylation in ADAMTS-5 activation in OA, and the underlying mechanisms. The potential for anti-OA intervention therapy which is based on modulating DNA methylation is also explored. Our results showed that DNA methyltransferases 1 (Dnmt1) downregulation-associated ADAMTS-5 promoter demethylation played an important role in ADAMTS-5 activation in OA, which facilitated SPI-1 binding on ADAMTS-5 promoter to activate ADAMTS-5 expression. More importantly, OA pathological phenotype of mice was alleviated in response to Dnmt1-induced DNA methylation of ADAMTS-5 promoter. Our study will benefit not only for deeper insights into the functional role and regulation mechanisms of ADAMTS-5 in OA, but also for the discovery of disease-modifying OA drugs on the basis of ADAMTS-5 via modulating DNA methylation status.

Laser frequency noise characterization using high-finesse plano-concave optical microresonators.

Characterizing laser frequency noise is essential for applications including optical sensing and coherent optical communications. Accurate measurement of ultra-narrow linewidth lasers over a wide frequency range using existing methods is still challenging. Here we present a method for characterizing the frequency noise of lasers using a high-finesse plano-concave optical microresonator (PCMR) acting as a frequency discriminator. To enable noise measurements at a wide range of laser frequencies, an array of PCMRs was produced with slight variations of thickness resulting in a series of discriminators operating at a series of periodical frequencies. This method enables measuring the frequency noise over a wide linewidth range (15 Hz to <100 MHz) over the 1440-1630 nm wavelength range. To assess the performance of the method, four different lasers were characterized, and the results were compared to the estimations of a commercial frequency noise analyzer.

CAWE-ACNN Algorithm for Coprime Sensor Array Adaptive Beamforming.

This paper presents a robust adaptive beamforming algorithm based on an attention convolutional neural network (ACNN) for coprime sensor arrays, named the CAWE-ACNN algorithm. In the proposed algorithm, via a spatial and channel attention unit, an ACNN model is constructed to enhance the features contributing to beamforming weight vector estimation and to improve the signal-to-interference-plus-noise ratio (SINR) performance, respectively. Then, an interference-plus-noise covariance matrix reconstruction algorithm is used to obtain an appropriate label for the proposed ACNN model. By the calculated label and the sample signals received from the coprime sensor arrays, the ACNN is well-trained and capable of accurately and efficiently outputting the beamforming weight vector. The simulation results verify that the proposed algorithm achieves excellent SINR performance and high computation efficiency.

Mitochondrial ATP Synthase beta-Subunit Affects Plastid Retrograde Signaling in Arabidopsis.

Plastid retrograde signaling plays a key role in coordinating the expression of plastid genes and photosynthesis-associated nuclear genes (PhANGs). Although plastid retrograde signaling can be substantially compromised by mitochondrial dysfunction, it is not yet clear whether specific mitochondrial factors are required to regulate plastid retrograde signaling. Here, we show that mitochondrial ATP synthase beta-subunit mutants with decreased ATP synthase activity are impaired in plastid retrograde signaling in Arabidopsis thaliana. Transcriptome analysis revealed that the expression levels of PhANGs were significantly higher in the mutants affected in the AT5G08670 gene encoding the mitochondrial ATP synthase beta-subunit, compared to wild-type (WT) seedlings when treated with lincomycin (LIN) or norflurazon (NF). Further studies indicated that the expression of nuclear genes involved in chloroplast and mitochondrial retrograde signaling was affected in the AT5G08670 mutant seedlings treated with LIN. These changes might be linked to the modulation of some transcription factors (TFs), such as LHY (Late Elongated Hypocotyl), PIF (Phytochrome-Interacting Factors), MYB, WRKY, and AP2/ERF (Ethylene Responsive Factors). These findings suggest that the activity of mitochondrial ATP synthase significantly influences plastid retrograde signaling.

Identification of bZIP Transcription Factors That Regulate the Development of Leaf Epidermal Cells in Arabidopsis thaliana by Single-Cell RNA Sequencing.

Epidermal cells are the main avenue for signal and material exchange between plants and the environment. Leaf epidermal cells primarily include pavement cells, guard cells, and trichome cells. The development and distribution of different epidermal cells are tightly regulated by a complex transcriptional regulatory network mediated by phytohormones, including jasmonic acid, and transcription factors. How the fate of leaf epidermal cells is determined, however, is still largely unknown due to the diversity of cell types and the complexity of their regulation. Here, we characterized the transcriptional profiles of epidermal cells in 3-day-old true leaves of Arabidopsis thaliana using single-cell RNA sequencing. We identified two genes encoding BASIC LEUCINE-ZIPPER (bZIP) transcription factors, namely bZIP25 and bZIP53, which are highly expressed in pavement cells and early-stage meristemoid cells. Densities of pavement cells and trichome cells were found to increase and decrease, respectively, in bzip25 and bzip53 mutants, compared with wild-type plants. This trend was more pronounced in the presence of jasmonic acid, suggesting that these transcription factors regulate the development of trichome cells and pavement cells in response to jasmonic acid.

Developing and validating the nurse-patient relationship scale (NPRS) in China.

BACKGROUND: Poor nurse-patient relationship poses an obstacle to care delivery, jeopardizing patient experience and patient care outcomes. Measuring nurse-patient relationship is challenging given its multi-dimensional nature and a lack of well-established scales. PURPOSE: This study aimed to develop a multi-dimensional scale measuring nurse-patient relationship in China. METHODS: A preliminary scale was constructed based on the existing literature and Delphi consultations with 12 nursing experts. The face validity of the scale was tested through a survey of 45 clinical nurses. This was followed by a validation study on 620 clinical nurses. Cronbach's α, content validity and known-group validity of the scale were assessed. The study sample was further divided into two for Exploratory Factor Analysis (EFA) and Confirmatory Factor Analysis (CFA), respectively, to assess the construct validity of the scale. RESULTS: The Nurse-Patient Relationship Scale (NPRS) containing 23 items was developed and validated, measuring five dimensions: nursing behavior, nurse understanding and respect for patient, patient misunderstanding and mistrust in nurse, communication with patient, and interaction with patient. The Cronbach's α of the NPRS ranged from 0.725 to 0.932, indicating high internal consistency. The CFA showed excellent fitness of data into the five-factor structure: χ2/df = 2.431, GFI = 0.933, TLI = 0.923, CFI = 0.939, IFI = 0.923, RMSEA = 0.070. Good content and construct validity are demonstrated through expert consensus and psychometric tests. CONCLUSION: The NPRS is a valid tool measuring nurse-patient relationship in China.

Caries lesions diagnosis with deep convolutional neural network in intraoral QLF images by handheld device.

OBJECTIVES: This study investigated the effectiveness of a deep convolutional neural network (CNN) in diagnosing and staging caries lesions in quantitative light-induced fluorescence (QLF) images taken by a self-manufactured handheld device. METHODS: A small toothbrush-like device consisting of a 400 nm UV light-emitting lamp with a 470 nm filter was manufactured for intraoral imaging. A total of 133 cases with 9,478 QLF images of teeth were included for caries lesion evaluation using a CNN model. The database was divided into development, validation, and testing cohorts at a 7:2:1 ratio. The accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and area under the receiver operating characteristic curve (AUC) were calculated for model performance. RESULTS: The overall caries prevalence was 19.59%. The CNN model achieved an AUC of 0.88, an accuracy of 0.88, a specificity of 0.94, and a sensitivity of 0.64 in the validation cohort. They achieved an overall accuracy of 0.92, a sensitivity of 0.95 and a specificity of 0.55 in the testing cohort. The model can distinguish different stages of caries well, with the best performance in detecting deep caries followed by intermediate and superficial lesions. CONCLUSIONS: Caries lesions have typical characteristics in QLF images and can be detected by CNNs. A QLF-based device with CNNs can assist in caries screening in the clinic or at home. TRIAL REGISTRATION: The clinical trial was registered in the Chinese Clinical Trial Registry (No. ChiCTR2300073487, Date: 12/07/2023).

Emotional labour and turnover intention among nurses in China: Mediating effects of nurse-patient relationship and self-rated health.

AIM: This study tested the mediating role of the nurse-patient relationship and self-rated health in the effect of emotional labour on turnover intention among nurses in China. BACKGROUND: The underlying mechanism behind the effect of emotional labour on turnover intention remains inadequately understood. INTRODUCTION: Nurses with a high level of emotional labour are predisposed to experiencing poor health and tension in their relationships with patients, which may increase turnover intention. METHODS: A cross-sectional survey of 527 nurses in a public tertiary hospital in Qiqihar, located in China's Heilongjiang province, was conducted. Emotional labour and turnover intention were assessed using existing validated scales containing multiple items, while the nurse-patient relationship and self-rated health were assessed using single items, respectively. Baron and Kenny's causal steps and the Karlson/Holm/Breen method were adopted to test the mediating effects of the nurse-patient relationship and self-rated health in the association between emotional labour and turnover intention after adjusting for variations in sociodemographic and job characteristics. RESULTS: Emotional labour was positively associated with turnover intention. Self-rated poor health and a disharmonious nurse-patient relationship partially mediated the positive effect of emotional labour on turnover intention. CONCLUSIONS: Emotional labour significantly affects the turnover intention of nurses working in public tertiary hospitals in China, and this effect is partially mediated by self-rated health and the nurse-patient relationship. IMPLICATIONS FOR NURSING PRACTICE AND NURSING POLICY: Giving more attention to nurses' negative emotions and work attitudes is crucial. Developing comprehensive strategies for enhancing nurses' emotional management ability, promoting their physical and psychological well-being, and improving nurse-patient relationship to reduce nurses' turnover.

OsSPL14 acts upstream of OsPIN1b and PILS6b to modulate axillary bud outgrowth by fine-tuning auxin transport in rice.

As a multigenic trait, rice tillering can optimize plant architecture for the maximum agronomic yield. SQUAMOSA PROMOTER BINDING PROTEIN-LIKE14 (OsSPL14) has been demonstrated to be necessary and sufficient to inhibit rice branching, but the underlying mechanism remains largely unclear. Here, we demonstrated that OsSPL14, which is cleaved by miR529 and miR156, inhibits tillering by fine-tuning auxin transport in rice. RNA interference of OsSPL14 or miR529 and miR156 overexpression significantly increased the tiller number, whereas OsSPL14 overexpression decreased the tiller number. Histological analysis revealed that the OsSPL14-overexpressing line had normal initiation of axillary buds but inhibited outgrowth of tillers. Moreover, OsSPL14 was found to be responsive to indole-acetic acid and 1-naphthylphthalamic acid, and RNA interference of OsSPL14 reduced polar auxin transport and increased 1-naphthylphthalamic acid sensitivity of rice plants. Further analysis revealed that OsSPL14 directly binds to the promoter of PIN-FORMED 1b (OsPIN1b) and PIN-LIKE6b (PILS6b) to regulate their expression positively. OsPIN1b and PILS6b were highly expressed in axillary buds and proved involved in bud outgrowth. Loss of function of OsPIN1b or PILS6b increased the tiller number of rice. Taken together, our findings suggested that OsSPL14 could control axillary bud outgrowth and tiller number by activating the expression of OsPIN1b and PILS6b to fine-tune auxin transport in rice.

Research strategies for single-cell transcriptome analysis in plant leaves.

The recent and continuous improvement in single-cell RNA sequencing (scRNA-seq) technology has led to its emergence as an efficient experimental approach in plant research. However, compared with single-cell research in animals and humans, the application of scRNA-seq in plant research is limited by several challenges, including cell separation, cell type annotation, cellular function analysis, and cell-cell communication networks. In addition, the unavailability of corresponding reliable and stable analysis methods and standards has resulted in the relative decentralization of plant single-cell research. Considering these shortcomings, this review summarizes the research progress in plant leaf using scRNA-seq. In addition, it describes the corresponding feasible analytical methods and associated difficulties and problems encountered in the current research. In the end, we provide a speculative overview of the development of plant single-cell transcriptome research in the future.

Identification of novel regulators required for early development of vein pattern in the cotyledons by single-cell RNA-sequencing.

The leaf veins of higher plants contain a highly specialized vascular system comprised of xylem and phloem cells that transport water, organic compounds and mineral nutrients. The development of the vascular system is controlled by phytohormones that interact with complex transcriptional regulatory networks. Before the emergence of true leaves, the cotyledons of young seedlings perform photosynthesis that provides energy for the sustainable growth and survival of seedlings. However, the mechanisms underlying the early development of leaf veins in cotyledons are still not fully understood, in part due to the complex cellular composition of this tissue. To better understand the development of leaf veins, we analyzed 14 117 single cells from 3-day-old cotyledons using single-cell RNA sequencing. Based on gene expression patterns, we identified 10 clusters of cells and traced their developmental trajectories. We discovered multiple new marker genes and developmental features of leaf veins. The transcription factor networks of some cell types indicated potential roles of CYCLING DOF FACTOR 5 (CDF5) and REPRESSOR OF GA (RGA) in the early development and function of the leaf veins in cotyledons. These new findings lay a foundation for understanding the early developmental dynamics of cotyledon veins. The mechanisms underlying the early development of leaf veins in cotyledons are still not fully understood. In this study, we comprehensively characterized the early differentiation and development of leaf veins in 3-day-old cotyledons based on single-cell transcriptome analysis. We identified the cell types and novel marker genes of leaf veins and characterized the novel regulators of leaf vein.

Cardiovascular Magnetic Resonance for Rejection Surveillance After Cardiac Transplantation.

BACKGROUND: Endomyocardial biopsy (EMB) is the gold standard method for surveillance of acute cardiac allograft rejection (ACAR) despite its invasive nature. Cardiovascular magnetic resonance (CMR)-based myocardial tissue characterization allows detection of myocarditis. The feasibility of CMR-based surveillance for ACAR-induced myocarditis in the first year after heart transplantation is currently undescribed. METHODS: CMR-based multiparametric mapping was initially assessed in a prospective cross-sectional fashion to establish agreement between CMR- and EMB-based ACAR and to determine CMR cutoff values between rejection grades. A prospective randomized noninferiority pilot study was then undertaken in adult orthotopic heart transplant recipients who were randomized at 4 weeks after orthotopic heart transplantation to either CMR- or EMB-based rejection surveillance. Clinical end points were assessed at 52 weeks. RESULTS: Four hundred one CMR studies and 354 EMB procedures were performed in 106 participants. Forty heart transplant recipients were randomized. CMR-based multiparametric assessment was highly reproducible and reliable at detecting ACAR (area under the curve, 0.92; sensitivity, 93%; specificity, 92%; negative predictive value, 99%) with greater specificity and negative predictive value than either T1 or T2 parametric CMR mapping alone. High-grade rejection occurred in similar numbers of patients in each randomized group (CMR, n=7; EMB, n=8; P=0.74). Despite similarities in immunosuppression requirements, kidney function, and mortality between groups, the rates of hospitalization (9 of 20 [45%] versus 18 of 20 [90%]; odds ratio, 0.091; P=0.006) and infection (7 of 20 [35%] versus 14 of 20 [70%]; odds ratio, 0.192; P=0,019) were lower in the CMR group. On 15 occasions (6%), patients who were randomized to the CMR arm underwent EMB for clarification or logistic reasons, representing a 94% reduction in the requirement for EMB-based surveillance. CONCLUSIONS: A noninvasive CMR-based surveillance strategy for ACAR in the first year after orthotopic heart transplantation is feasible compared with EMB-based surveillance. REGISTRATION: HREC/13/SVH/66 and HREC/17/SVH/80. AUSTRALIAN NEW ZEALAND CLINICAL TRIALS REGISTRY: ACTRN12618000672257.

Highly Connected Three-Dimensional Covalent Organic Framework with Flu Topology for High-Performance Li-S Batteries.

Lithium-sulfur batteries (LSBs) have been considered as a promising candidate for next-generation energy storage devices, which however still suffer from the shuttle effect of the intermediate lithium polysulfides (LiPSs). Covalent-organic frameworks (COFs) have exhibited great potential as sulfur hosts for LSBs to solve such a problem. Herein, a pentiptycene-based D2h symmetrical octatopic polyaldehyde, 6,13-dimethoxy-2,3,9,10,18,19,24,25-octa(4'-formylphenyl)pentiptycene (DMOPTP), was prepared and utilized as a building block toward preparing COFs. Condensation of DMOPTP with 4-connected tetrakis(4-aminophenyl)methane affords an expanded [8 + 4] connected network 3D-flu-COF, with a flu topology. The non-interpenetrated nature of the flu topology endows 3D-flu-COF with a high Brunauer-Emmett-Teller surface area of 2860 m2 g-1, large octahedral cavities, and cross-linked tunnels in the framework, enabling a high loading capacity of sulfur (∼70 wt %), strong LiPS adsorption capability, and facile ion diffusion. Remarkably, when used as a sulfur host for LSBs, 3D-flu-COF delivers a high capacity of 1249 mA h g-1 at 0.2 C (1.0 C = 1675 mA g-1), outstanding rate capability (764 mA h g-1 at 5.0 C), and excellent stability, representing one of the best results among the thus far reported COF-based sulfur host materials for LSBs and being competitive with the state-of-the-art inorganic host materials.

Biocompatible Fluorescent Biosensor Reveals the Level and Distribution of Indole-3-Acetic Acid Signals in Plants.

To fully understand the function of the phytohormone indole-3-acetic acid (IAA) in regulating plant growth and development, we need to monitor their levels and distribution with high spatial and temporal resolution. In this work, an anthracene-based fluorescent biosensor for IAA was prepared using bovine serum albumin (BSA) as a bio-template. The single linear oxygen (1O2) specifically produced by IAA catalyzed with horseradish peroxidase (HRP) turns on the fluorescence of the probe, enabling specific trace sensing of IAA in the presence of multiple structural analogues. The presence of the bio-template BSA extends the biocompatibility of the probe, enabling visual monitoring of the level and distribution signal of endogenous IAA of plants in the field of bioimaging. In addition, the strategy has shown potential for application in portable paper-based sensors and in vivo fluorescent flower culture. This work provides a technical and theoretical basis for exploring the growth regulatory mechanisms of IAA in plants at the molecular level.

Strontium ranelate enriched Ruminococcus albus in the gut microbiome of Sprague-Dawley rats with postmenopausal osteoporosis.

BACKGROUND: Gut microbiome is critical to our human health and is related to postmenopausal osteoporosis (PMO). Strontium ranelate (SrR) is an anti-osteoporosis oral drug that can promote osteoblast formation and inhibit osteoclast formation. However, the effect of SrR on gut microbiome has been rarely studied. Therefore, we investigated the effect of oral SrR on gut microbiome and metabolic profiles. RESULTS: In this study, we used ovariectomized (OVX) Sprague-Dawley rats to construct a PMO model and applied oral SrR for 6 weeks. The relative abundance of intestinal microbiome was investigated by 16S rRNA metagenomic sequencing. Ultra-high-performance liquid chromatography-mass spectrometry (UHPLC-MS) was used to analyze changes in metabolites of intestinal contents. Results demonstrated that 6-week oral SrR alleviated osteoporosis and significantly changed the composition of the gut microbiome and metabolic profiles of OVX rats. Ruminococcus, Akkermansia and Oscillospira were significantly enriched in the gut of OVX rats after 6-week oral SrR. Especially, the species R. albus showed the greatest importance by a random forest classifier between OVX and OVX_Sr group. The enrichment of R. albus in the gut was positively correlated with bone mineral density and the accumulation of lycopene and glutaric acid, which also significantly elevated after oral SrR. CONCLUSIONS: We discovered that oral SrR can improve bone health while stimulate the accumulation of gut microbe R. albus and metabolites (lycopene and glutaric acid). The results suggested possible connections between oral SrR and the gut-bone axis, which may provide new insight into the treatment/prevention of osteoporosis.

Genetic regulation of nitrogen use efficiency in Gossypium spp.

Cotton (Gossypium spp.) is the most important fibre crop, with desirable characteristics preferred for textile production. Cotton fibre output relies heavily on nitrate as the most important source of inorganic nitrogen (N). However, nitrogen dynamics in extreme environments limit plant growth and lead to yield loss and pollution. Therefore, nitrogen use efficiency (NUE), which involves the utilisation of the 'right rate', 'right source', 'right time', and 'right place' (4Rs), is key for efficient N management. Recent omics techniques have genetically improved NUE in crops. We herein highlight the mechanisms of N uptake and assimilation in the vegetative and reproductive branches of the cotton plant while considering the known and unknown regulatory factors. The phylogenetic relationships among N transporters in four Gossypium spp. have been reviewed. Further, the N regulatory genes that participate in xylem transport and phloem loading are also discussed. In addition, the functions of microRNAs and transcription factors in modulating the expression of target N regulatory genes are highlighted. Overall, this review provides a detailed perspective on the complex N regulatory mechanism in cotton, which would accelerate the research toward improving NUE in crops.

Benefits of cascaded nonlinear dynamics in hybrid fibers for low-noise supercontinuum generation.

The recent development of fiber supercontinuum (SC) sources with ultra-low noise levels has been instrumental in advancing the state-of-the-art in a wide range of research topics. However, simultaneously satisfying the application demands of maximizing spectral bandwidth and minimizing noise is a major challenge that so far has been addressed with compromise, found by fine-tuning the characteristics of a single nonlinear fiber transforming the injected laser pulses into a broadband SC. In this work, we investigate a hybrid approach that splits the nonlinear dynamics into two discrete fibers optimized for nonlinear temporal compression and spectral broadening, respectively. This introduces new design degrees of freedom, making it possible to select the best fiber for each stage of the SC generation process. With experiments and simulations we study the benefits of this hybrid approach for three common and commercially available highly nonlinear fiber (HNLF) designs, focusing on flatness, bandwidth and relative intensity noise of the generated SC. In our results, hybrid all-normal dispersion (ANDi) HNLF stand out as they combine the broad spectral bandwidths associated with soliton dynamics with extremely low noise and smooth spectra known from normal dispersion nonlinearities. Hybrid ANDi HNLF are a simple and low-cost route for implementing ultra-low noise SC sources and scaling their repetition rate for various applications such as biophotonic imaging, coherent optical communications, or ultrafast photonics.

Low-latency wavelength-switched clock-synchronized intra-data center interconnects enabled by hollow core fiber.

Fast (nanoseconds) optical wavelength switching is emerging as a viable solution to scaling the size and capacity of intra-data center interconnection. A key enabling technology for such systems is low-jitter optical clock synchronization, which enables sub-nanosecond clock and data recovery for optically switched frames using low-cost methods such as clock phase caching. We propose and demonstrate real-time low-latency wavelength-switched clock-synchronized intra-data center interconnection at 51.2 GBd using a fast tunable laser (with ns scale switching time) and ultra-stable-latency hollow core fiber (HCF) for optically-switched data center networks. For wavelength-switched systems, we achieve a physical layer latency below 46 ns, consisting of 28 ns transceiver latency and a 18 ns inter-packet gap. Finally, we show that by exploiting the low chromatic dispersion and thermally-stable latency features of HCF, active clock phase tracking can be entirely eliminated.