Selenium-catalyzed allylic C-H phosphoramidation of alkenes.

We report herein a synthesis of allylic phosphoramidates from alkenes by selenium-catalyzed allylic C-H derivatization. This method features mild conditions, broad substrate scope, and high functional group tolerance, enabling late-stage modification of a number of complex substrates. In addition, this protocol was applied to modify caryophyllene and produced a photoaffinity probe capable of proteomic target labeling in live HeLa cells.

Tiny-Machine-Learning-Based Supply Canal Surface Condition Monitoring.

The South-to-North Water Diversion Project in China is an extensive inter-basin water transfer project, for which ensuring the safe operation and maintenance of infrastructure poses a fundamental challenge. In this context, structural health monitoring is crucial for the safe and efficient operation of hydraulic infrastructure. Currently, most health monitoring systems for hydraulic infrastructure rely on commercial software or algorithms that only run on desktop computers. This study developed for the first time a lightweight convolutional neural network (CNN) model specifically for early detection of structural damage in water supply canals and deployed it as a tiny machine learning (TinyML) application on a low-power microcontroller unit (MCU). The model uses damage images of the supply canals that we collected as input and the damage types as output. With data augmentation techniques to enhance the training dataset, the deployed model is only 7.57 KB in size and demonstrates an accuracy of 94.17 ± 1.67% and a precision of 94.47 ± 1.46%, outperforming other commonly used CNN models in terms of performance and energy efficiency. Moreover, each inference consumes only 5610.18 µJ of energy, allowing a standard 225 mAh button cell to run continuously for nearly 11 years and perform approximately 4,945,055 inferences. This research not only confirms the feasibility of deploying real-time supply canal surface condition monitoring on low-power, resource-constrained devices but also provides practical technical solutions for improving infrastructure security.

LINbase: a web server for genome-based identification of prokaryotes as members of crowdsourced taxa.

High throughput DNA sequencing in combination with efficient algorithms could provide the basis for a highly resolved, genome phylogeny-based and digital prokaryotic taxonomy. However, current taxonomic practice continues to rely on cumbersome journal publications for the description of new species, which still constitute the smallest taxonomic units. In response, we introduce LINbase, a web server that allows users to genomically circumscribe any group of prokaryotes with measurable DNA similarity and that uses the individual isolate as smallest unit. Since LINbase leverages the concept of Life Identification Numbers (LINs), which are codes assigned to individual genomes based on reciprocal average nucleotide identity, we refer to groups circumscribed in LINbase as LINgroups. Users can associate with each LINgroup a name, a short description, and a URL to a peer-reviewed publication. As soon as a LINgroup is circumscribed, any user can immediately identify query genomes as members and submit comments about the LINgroup. Most genomes currently in LINbase were imported from GenBank, but users can upload their own genome sequences as well. In conclusion, LINbase combines the resolution of LINs with the power of crowdsourcing in support of a highly resolved, genome phylogeny-based digital taxonomy. LINbase is available at http://www.LINbase.org.

A Facile Synthesis of 2-Oxazolines via Dehydrative Cyclization Promoted by Triflic Acid.

2-oxazolines are common moieties in numerous natural products, pharmaceuticals, and functional copolymers. Current methods for synthesizing 2-oxazolines mainly rely on stoichiometric dehydration agents or catalytic dehydration promoted by specific catalysts. These conditions either generate stoichiometric amounts of waste or require forcing azeotropic reflux conditions. As such, a practical and robust method that promotes dehydrative cyclization while generating no byproducts would be attractive to oxazoline production. Herein, we report a triflic acid (TfOH)-promoted dehydrative cyclization of N-(2-hydroxyethyl)amides for synthesizing 2-oxazolines. This reaction tolerates various functional groups and generates water as the only byproduct. This method affords oxazoline with inversion of α-hydroxyl stereochemistry, suggesting that alcohol is activated as a leaving group under these conditions. Furthermore, the one-pot synthesis protocol of 2-oxazolines directly from carboxylic acids and amino alcohols is also provided.

A HiPAD Integrated with rGO/MWCNTs Nano-Circuit Heater for Visual Point-of-Care Testing of SARS-CoV-2.

Nowadays, the main obstacle for further miniaturization and integration of nucleic acids point-of-care testing devices is the lack of low-cost and high-performance heating materials for supporting reliable nucleic acids amplification. Herein, reduced graphene oxide hybridized multi-walled carbon nanotubes nano-circuit integrated into an ingenious paper-based heater is developed, which is integrated into a paper-based analytical device (named HiPAD). The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is still raging across the world. As a proof of concept, the HiPAD is utilized to visually detect the SARS-CoV-2 N gene using colored loop-mediated isothermal amplification reaction. This HiPAD costing a few dollars has comparable detection performance to traditional nucleic acids amplifier costing thousands of dollars. The detection range is from 25 to 2.5 × 1010 copies mL-1 in 45 min. The detection limit of 25 copies mL-1 is 40 times more sensitive than 1000 copies mL-1 in conventional real-time PCR instruments. The disposable paper-based chip could also avoid potential secondary transmission of COVID-19 by convenient incineration to guarantee biosafety. The HiPAD or easily expanded M-HiPAD (for multiplex detection) has great potential for pathogen diagnostics in resource-limited settings.

Descending pathways generate perception of and neural responses to weak sensory input.

Natural sensory stimuli frequently consist of a fast time-varying waveform whose amplitude or contrast varies more slowly. While changes in contrast carry behaviorally relevant information necessary for sensory perception, their processing by the brain remains poorly understood to this day. Here, we investigated the mechanisms that enable neural responses to and perception of low-contrast stimuli in the electrosensory system of the weakly electric fish Apteronotus leptorhynchus. We found that fish reliably detected such stimuli via robust behavioral responses. Recordings from peripheral electrosensory neurons revealed stimulus-induced changes in firing activity (i.e., phase locking) but not in their overall firing rate. However, central electrosensory neurons receiving input from the periphery responded robustly via both phase locking and increases in firing rate. Pharmacological inactivation of feedback input onto central electrosensory neurons eliminated increases in firing rate but did not affect phase locking for central electrosensory neurons in response to low-contrast stimuli. As feedback inactivation eliminated behavioral responses to these stimuli as well, our results show that it is changes in central electrosensory neuron firing rate that are relevant for behavior, rather than phase locking. Finally, recordings from neurons projecting directly via feedback to central electrosensory neurons revealed that they provide the necessary input to cause increases in firing rate. Our results thus provide the first experimental evidence that feedback generates both neural and behavioral responses to low-contrast stimuli that are commonly found in the natural environment.

Optimized Parallel Coding of Second-Order Stimulus Features by Heterogeneous Neural Populations.

UNLABELLED: Efficient processing of sensory input is essential to ensure an organism's survival in its natural environment. Growing evidence suggests that sensory neurons can optimally encode natural stimuli by ensuring that their tuning opposes stimulus statistics, such that the resulting neuronal response contains equal power at all frequencies (i.e., is "white"). Such temporal decorrelation or whitening has been observed across modalities, but the effects of neural heterogeneities on determining tuning and thus responses to natural stimuli have not been investigated. Here, we investigate how heterogeneities in sensory pyramidal neurons organized in three parallel maps representing the body surface determine responses to second-order electrosensory stimulus features in the weakly electric fish Apteronotus leptorhynchus While some sources of heterogeneities such as ON- and OFF-type responses to first-order did not affect responses to second-order electrosensory stimulus features, other sources of heterogeneity within and across the maps strongly determined responses. We found that these cells effectively performed a fractional differentiation operation on their input with exponents ranging from zero (no differentiation) to 0.4 (strong differentiation). Varying adaptation in a simple model explained these heterogeneities and predicted a strong correlation between fractional differentiation and adaptation. Using natural stimuli, we found that only a small fraction of neurons implemented temporal whitening. Rather, a large fraction of neurons did not perform any significant whitening and thus preserved natural input statistics in their responses. We propose that this information is needed to properly decode optimized information sent in parallel through temporally whitened responses based on context. SIGNIFICANCE STATEMENT: We demonstrate that heterogeneities in the same sensory neuron type can either have no or significant influence on their responses to second-order stimulus features. While an ON- or OFF-type response to first-order stimulus attributes has no significant influence on responses to second-order stimulus features, we found that only a small fraction of sensory neurons optimally encoded natural stimuli through high-pass filtering, thereby implementing temporal whitening. Surprisingly, a large fraction of sensory neurons performed little if no filtering of stimuli, thereby preserving natural stimulus statistics. We hypothesize that this pathway is necessary to properly decode optimized information contained in temporally whitened responses based on context.

Increased listening effort and decreased speech discrimination at high presentation sound levels in acoustic hearing listeners and cochlear implant users.

The sounds we experience in our everyday communication can vary greatly in terms of level and background noise depending on the environment. Paradoxically, increasing the sound intensity may lead to worsened speech understanding, especially in noise. This is known as the "Rollover" phenomenon. There have been limited studies on rollover and how it is experienced differentially across aging groups, for those with and without hearing loss, as well as cochlear implant (CI) users. There is also mounting evidence that listening effort plays an important role in challenging listening conditions and can be directly quantified with objective measures such as pupil dilation. We found that listening effort was modulated by sound level and that rollover occurred primarily in the presence of background noise. The effect on listening effort was exacerbated by age and hearing loss in acoustic listeners, with greatest effect in older listeners with hearing loss, while there was no effect in CI users. The age- and hearing-dependent effects of rollover highlight the potential negative impact of amplification to high sound levels and therefore has implications for effective treatment of age-related hearing loss.

Boosting humoral and cellular immunity with enhanced STING activation by hierarchical mesoporous metal-organic framework adjuvants.

Vaccination is essential for preventing and controlling infectious diseases, along with reducing mortality. Developing safe and versatile adjuvants to enhance humoral and cellular immune responses to vaccines remains a key challenge in vaccine development. Here, we designed hierarchical mesoporous MOF-801 (HM801) using a Cocamidopropyl betaine (CAPB) and a Pluronics F127 in an aqueous phase system. Meanwhile, we synthesized a novel SARS-CoV-2 nanovaccine (R@M@HM801) with a high loading capacity for both the STING agonist (MSA-2) and the Delta receptor binding domain (Delta-RBD) antigen. R@M@HM801 enhanced MSA-2 and RBD utilization and effectively co-delivered MSA-2 and RBD antigens to antigen-presenting cells in the draining lymph nodes, thereby promoting the activation of both T and B cells. Lymphocyte single-cell analysis showed that R@M@HM801 stimulated robust CD11b+CD4+ T cells, CXCR5+CD4+ T follicular helper (Tfh), and durable CD4+CD44+CD62L-, CD8+CD44+CD62L- effector memory T cell (TEM) immune responses, and promoted the proliferative activation of CD26+ B cells in vivo. Meanwhile, R@M@HM801 induced stronger specific antibodies and neutralization of pseudovirus against Delta compared to the RBD + MAS-2 and RBD + MAS-2 + Alum vaccines. Our study demonstrated the efficacy of a hierarchical mesoporous HM801 and its potential immune activation mechanism in enhancing adaptive immune responses against viruses and other diseases.

Protective effects of Pt-N-C single-atom nanozymes against myocardial ischemia-reperfusion injury.

Effective therapeutic strategies for myocardial ischemia/reperfusion (I/R) injury remain elusive. Targeting reactive oxygen species (ROS) provides a practical approach to mitigate myocardial damage following reperfusion. In this study, we synthesize an antioxidant nanozyme, equipped with a single-Platinum (Pt)-atom (PtsaN-C), for protecting against I/R injury. PtsaN-C exhibits multiple enzyme-mimicking activities for ROS scavenging with high efficiency and stability. Mechanistic studies demonstrate that the excellent ROS-elimination performance of the single Pt atom center precedes that of the Pt cluster center, owing to its better synergistic effect and metallic electronic property. Systematic in vitro and in vivo studies confirm that PtsaN-C efficiently counteracts ROS, restores cellular homeostasis and prevents apoptotic progression after I/R injury. PtsaN-C also demonstrates good biocompatibility, making it a promising candidate for clinical applications. Our study expands the scope of single-atom nanozyme in combating ROS-induced damage and offers a promising therapeutic avenue for the treatment of I/R injury.

Adaptive Fixed-Time Neural Control for Uncertain Nonlinear Multiagent Systems.

In this article, we consider the problem of adaptive fixed-time tracking control for a class of multiagent systems (MASs) with mismatched uncertainty. Unlike the existing methodologies that only implement the practical finite-/fixed-time stability for MASs, a newly adaptive consensus control criterion is developed to reach fixed-time stability, where the controller design includes a series of newly Lyavonov functions and modified tuning functions. Radial basis function neural networks are employed to deal with the unknown functions in each agent, and the direct adaptive strategy solves the obstacle of "explosion of complexity." Under the performance-oriented controller, the error of the MASs converges to a predetermined interval within a fixed time. Two simulations illustrate the results obtained.

Calcipotriol Attenuates Form Deprivation Myopia Through a Signaling Pathway Parallel to TGF-ß2-Induced Increases in Collagen Expression.

Purpose: To determine the role of calcipotriol, a vitamin D3 analogue, in myopia development and altering the expression of scleral α1 chain of type I collagen (Col1α1) in mice. We also aimed to identify if the signaling pathway mediating the above changes is different from the one involved in transforming growth factor ß2 (TGF-ß2)-mediated increases of COL1A1 in cultured human scleral fibroblasts (HSFs). Methods: C57BL/6J mice were either intraperitoneally injected with calcipotriol and subjected to form deprivation (FD) or exposed to normal refractive development for 4 weeks. Scleral vitamin D receptor (Vdr) expression was knocked down using a Sub-Tenon's capsule injection of an adeno-associated virus-packaged short hairpin RNA (AAV8-shRNA). Refraction and biometric measurements evaluated myopia development. A combination of knockdown and induction strategies determined the relative contributions of the vitamin D3 and the TGF-ß2 signaling pathways in modulating COL1A1 expression in HSFs. Results: Calcipotriol injections suppressed FD-induced myopia (FDM), but it had no significant effect on normal refractive development. AAV8-shRNA injection reduced Vdr mRNA expression by 42% and shifted the refraction toward myopia (-3.15 ± 0.99D, means ± SEM) in normal eyes. In HSFs, VDR knockdown reduced calcipotriol-induced rises in COL1A1 expression, but it did not alter TGF-ß2-induced increases in COL1A1 expression. Additionally, TGF-ß2 augmented calcipotriol-induced rises in COL1A1 expression. TGF-ß receptor (TGFBRI/II) knockdown blunted TGF-ß2-induced increases in COL1A1 expression, whereas calcipotriol-induced increases in VDR and COL1A1 expression levels were unaltered. Conclusions: Scleral vitamin D3 inhibits myopia development in mice, potentially by activating a VDR-dependent signaling pathway and increasing scleral COL1A1 expression levels.

Deep learning-based detection and classification of lumbar disc herniation on magnetic resonance images.

Background: The severity assessment of lumbar disc herniation (LDH) on MR images is crucial for selecting suitable surgical candidates. However, the interpretation of MR images is time-consuming and requires repetitive work. This study aims to develop and evaluate a deep learning-based diagnostic model for automated LDH detection and classification on lumbar axial T2-weighted MR images. Methods: A total of 1115 patients were analyzed in this retrospective study; both a development dataset (1015 patients, 15 249 images) and an external test dataset (100 patients, 1273 images) were utilized. According to the Michigan State University (MSU) classification criterion, experts labeled all images with consensus, and the final labeled results were regarded as the reference standard. The automated diagnostic model comprised Faster R-CNN and ResNeXt101 as the detection and classification network, respectively. The deep learning-based diagnostic performance was evaluated by calculating mean intersection over union (IoU), accuracy, precision, sensitivity, specificity, F1 score, the area under the receiver operating characteristics curve (AUC), and intraclass correlation coefficient (ICC) with 95% confidence intervals (CIs). Results: High detection consistency was obtained in the internal test dataset (mean IoU = 0.82, precision = 98.4%, sensitivity = 99.4%) and external test dataset (mean IoU = 0.70, precision = 96.3%, sensitivity = 97.8%). Overall accuracy for LDH classification was 87.70% (95% CI: 86.59%-88.86%) and 74.23% (95% CI: 71.83%-76.75%) in the internal and external test datasets, respectively. For internal testing, the proposed model achieved a high agreement in classification (ICC = 0.87, 95% CI: 0.86-0.88, P < 0.001), which was higher than that of external testing (ICC = 0.79, 95% CI: 0.76-0.81, P < 0.001). The AUC for model classification was 0.965 (95% CI: 0.962-0.968) and 0.916 (95% CI: 0.908-0.925) in the internal and external test datasets, respectively. Conclusions: The automated diagnostic model achieved high performance in detecting and classifying LDH and exhibited considerable consistency with experts' classification.

Recent Progresses in Electrochemical DNA Biosensors for MicroRNA Detection.

MicroRNAs (miRNAs), as the small, non-coding, evolutionary conserved, and post-transcriptional gene regulators of the genome, have been highly associated with various diseases such as cancers, viral infections, and cardiovascular diseases. Several techniques have been established to detect miRNAs, including northern blotting, real-time polymerase chain reaction (RT-PCR), and fluorescent microarray platform. However, it remains a significant challenge to develop sensitive, accurate, rapid, and cost-effective methods to detect miRNAs due to their short size, high similarity, and low abundance. The electrochemical biosensors exhibit tremendous potential in miRNA detection because they satisfy feature integration, portability, mass production, short response time, and minimal sample consumption. This article reviewed the working principles and signal amplification strategies of electrochemical DNA biosensors summarized the recent improvements. With the development of DNA nanotechnology, nanomaterials and biotechnology, electrochemical DNA biosensors of high sensitivity and specificity for microRNA detection will shortly be commercially accessible.

2'-O-Methyl modified guide RNA promotes the single nucleotide polymorphism (SNP) discrimination ability of CRISPR-Cas12a systems.

The CRISPR-Cas12a system has been widely applied to genome editing and molecular diagnostics. However, off-target cleavages and false-positive results remain as major concerns in Cas12a practical applications. Herein, we propose a strategy by utilizing the 2'-O-methyl (2'-OMe) modified guide RNA (gRNA) to promote the Cas12a's specificity. Gibbs free energy analysis demonstrates that the 2'-OMe modifications at the 3'-end of gRNA effectively suppress the Cas12a's overall non-specific affinity while maintaining high on-target affinity. For general application illustrations, HBV genotyping and SARS-CoV-2 D614G mutant biosensing platforms are developed to validate the enhanced Cas12a's specificity. Our results indicate that the 2'-OMe modified gRNAs could discriminate single-base mutations with at least two-fold enhanced specificity compared to unmodified gRNAs. Furthermore, we investigate the enhancing mechanisms of the 2'-OMe modified Cas12a systems by molecular docking simulations and the results suggest that the 2'-OMe modifications at the 3'-end of gRNA reduce the Cas12a's binding activity to off-target DNA. This work offers a versatile and universal gRNA design strategy for highly specific Cas12a system development.

Encountering and Wrestling: Neutrophils Recognize and Defensively Degrade Graphene Oxide.

The boosting exploitation of graphene oxide (GO) increases exposure risk to human beings. However, as primary defender in the first immune line, neutrophils' mechanism of defensive behavior toward GO remains unclear. Herein, we discovered that neutrophils recognize and defensively degrade GO in a lateral dimension dependent manner. The micrometer-sized GO (mGO) induces NETosis by releasing neutrophil extracellular traps (NETs), while nanometer-sized GO (nGO) elicits neutrophil degranulation. The two neutrophils' defensive behaviors are accompanied with generation of reactive oxygen species and activation of p-ERK and p-Akt kinases. However, mGO-induced NETosis is NADPH oxidase (NOX)-independent while nGO-triggered degranulation is NOX-dependent. Furthermore, myeloperoxidase (MPO) is determinant mediator despite distinct neutrophil phenotypes. Neutrophils release NETs comprising of MPO upon activated with mGO, while MPO is secreted via nGO-induced degranulation. Moreover, the binding energy between MPO and GO is calculated to be 69.8728 kJ mol-1 , indicating that electrostatic interactions mainly cause the spontaneous binding process. Meanwhile, the central enzymatic biodegradation occurs at oxygenic active sites and defects on GO. Mass spectrometry analysis deciphers the degradation products are biocompatible molecules like flavonoids and polyphenols. This study provides fundamental evidence and practical guidance for nanotechnology based on GO, including vaccine adjuvant, implantable devices, and energy storage.

Znhit1 Regulates p21Cip1 to Control Mouse Lens Differentiation.

Purpose: The transparency of the ocular lens is essential for refracting and focusing light onto the retina, and transparency is controlled by many factors and signaling pathways. Here we showed a critical role of chromatin remodeler zinc finger HIT-type containing 1 (Znhit1) in maintaining lens transparency. Methods: To explore the roles of Znhit1 in lens development, the cre-loxp system was used to generate lens-specific Znhit1 knockout mice (Znhit1Mlr10-Cre; Znhit1 cKO). Morphological changes in mice lenses were examined using hematoxylin and eosin staining. RNA sequencing (RNA-seq) and assay for transposase accessible chromatin using sequencing (ATAC-seq) were applied to screen transcriptome changes. Immunofluorescence staining were performed to assess proteins distribution and terminal deoxynucleotidyl transferase dUTP nick-end labeling staining were used for determining apoptosis. The mRNAs expression was examined by quantitative RT-PCR and proteins expression by Western blot. Results: Lens-specific conditional knockout mice had a severe cataract, microphthalmia phenotype, and seriously abnormal lens fiber cells differentiation. Deletion of Znhit1 in the lens resulted in decreased cell proliferation and increased cell apoptosis of the lens epithelia. ATAC-seq showed that Znhit1 deficiency increased chromatin accessibility of cyclin-dependent kinase inhibitors, including p57Kip2 and p21Cip1, and upregulated the expression of these genes in mRNA and protein levels. And we also showed that loss of Znhit1 lead to lens fibrosis by upregulating the expression of p21Cip1. Conclusions: Our findings suggested that Znhit1 is required for the survival of lens epithelial cells. The loss of Znhit1 leads to the overexpression of p21Cip1, further resulting in lens fibrosis, and impacted the establishment of lens transparency.

Automatic Grading of Disc Herniation, Central Canal Stenosis and Nerve Roots Compression in Lumbar Magnetic Resonance Image Diagnosis.

Aim: Accurate severity grading of lumbar spine disease by magnetic resonance images (MRIs) plays an important role in selecting appropriate treatment for the disease. However, interpreting these complex MRIs is a repetitive and time-consuming workload for clinicians, especially radiologists. Here, we aim to develop a multi-task classification model based on artificial intelligence for automated grading of lumbar disc herniation (LDH), lumbar central canal stenosis (LCCS) and lumbar nerve roots compression (LNRC) at lumbar axial MRIs. Methods: Total 15254 lumbar axial T2W MRIs as the internal dataset obtained from the Fifth Affiliated Hospital of Sun Yat-sen University from January 2015 to May 2019 and 1273 axial T2W MRIs as the external test dataset obtained from the Third Affiliated Hospital of Southern Medical University from June 2016 to December 2017 were analyzed in this retrospective study. Two clinicians annotated and graded all MRIs using the three international classification systems. In agreement, these results served as the reference standard; In disagreement, outcomes were adjudicated by an expert surgeon to establish the reference standard. The internal dataset was randomly split into an internal training set (70%), validation set (15%) and test set (15%). The multi-task classification model based on ResNet-50 consists of a backbone network for feature extraction and three fully-connected (FC) networks for classification and performs the classification tasks of LDH, LCCS, and LNRC at lumbar MRIs. Precision, accuracy, sensitivity, specificity, F1 scores, confusion matrices, receiver-operating characteristics and interrater agreement (Gwet k) were utilized to assess the model's performance on the internal test dataset and external test datasets. Results: A total of 1115 patients, including 1015 patients from the internal dataset and 100 patients from the external test dataset [mean age, 49 years ± 15 (standard deviation); 543 women], were evaluated in this study. The overall accuracies of grading for LDH, LCCS and LNRC were 84.17% (74.16%), 86.99% (79.65%) and 81.21% (74.16%) respectively on the internal (external) test dataset. Internal and external testing of three spinal diseases showed substantial to the almost perfect agreement (k, 0.67 - 0.85) for the multi-task classification model. Conclusion: The multi-task classification model has achieved promising performance in the automated grading of LDH, LCCS and LNRC at lumbar axial T2W MRIs.

Decreased Choroidal Blood Perfusion Induces Myopia in Guinea Pigs.

Purpose: The development of myopia in guinea pigs can be inhibited by attenuating scleral hypoxia by increasing choroidal blood perfusion (ChBP). In this study, we reduced ChBP through surgical and pharmacological methods to determine the effect on myopia development. We also determined whether ChBP was reduced by quinpirole, a drug that enhances form-deprivation myopia (FDM). Methods: ChBP was reduced in the right eyes of guinea pigs via transection of the temporal ciliary arteries or daily injections of phenylephrine into the inferior peribulbar space for one week during normal ocular growth. Other guinea pigs were subjected to two weeks of monocular FDM-with facemasks, along with daily injections of quinpirole, a dopamine D2 receptor agonist, to enhance the FDM. Changes in refraction, axial length, ChBP, and choroidal thickness (ChT) were measured in both treated and fellow eyes of the treatment and control groups. Scleral hypoxia labeling with pimonidazole adducts and α-smooth muscle actin (α-SMA) protein were also measured. Results: Surgical and pharmacological reduction of ChBP induced myopia development in the treated eyes. These treatments rendered the scleral hypoxia and increased scleral α-SMA expression. Furthermore, quinpirole injections, which increased the magnitude of myopia, augmented the FDM-associated reductions in ChBP and ChT and increased the levels of scleral hypoxia and α-SMA protein. Conclusions: Decreased ChBP in guinea pigs leads to scleral hypoxia and scleral myofibroblast transdifferentiation with increased α-SMA expression, ultimately resulting in myopia development. In future clinical trials, ChBP reduction can serve as a potential biomarker for early detection of myopia development.

New Structure Mass Tag based on Zr-NMOF for Multiparameter and Sensitive Single-Cell Interrogating in Mass Cytometry.

Mass cytometry, also called cytometry by time-of-flight (CyTOF), is an emerging powerful proteomic analysis technique that utilizes metal chelated polymer (MCP) as mass tags for interrogating high-dimensional biomarkers simultaneously on millions of individual cells. However, under the typical polymer-based mass tag system, the sensitivity and multiplexing detection ability has been highly restricted. Herein, a new structure mass tag based on a nanometal organic framework (NMOF) is reported for multiparameter and sensitive single-cell biomarker interrogating in CyTOF. A uniform-sized Zr-NMOF (33 nm) carrying 105 metal ions is synthesized under modulator/reaction time coregulation, which is monodispersed and colloidally stable in water for over one-year storage. On functionalization with an antibody, the Zr mass tag exhibits specific molecular recognition properties and minimal cross-reaction toward nontargeted cells. In addition, the Zr-mass tag is compatible with MCP mass tags in a multiparameter assay for mouse spleen cells staining, which exploits four additional channels, m/z = 90, 91, 92, 94, for single-cell immunoassays in CyTOF. Compared to the MCP mass tag, the Zr-mass tag provides an additional fivefold signal amplification. This work provides the fundamental technical capability for exploiting NMOF-based mass tags for CyTOF application, which opens up possibility of high-dimensional single-cell immune profiling, low abundant antigen detection, and development of new barcoding systems.