Small-Molecule-Based Fluorescent Sensors for Selective Detection of Reactive Oxygen Species in Biological Systems.

Reactive oxygen species (ROS) encompass a collection of intricately linked chemical entities characterized by individually distinct physicochemical properties and biological reactivities. Although excessive ROS generation is well known to underpin disease development, it has become increasingly evident that ROS also play central roles in redox regulation and normal physiology. A major challenge in uncovering the relevant biological mechanisms and deconvoluting the apparently paradoxical roles of distinct ROS in human health and disease lies in the selective and sensitive detection of these transient species in the complex biological milieu. Small-molecule-based fluorescent sensors enable molecular imaging of ROS with great spatial and temporal resolution and have thus been appreciated as excellent tools for aiding discoveries in modern redox biology. We review a selection of state-of-the-art sensors with demonstrated utility in biological systems. By providing a systematic overview based on underlying chemical sensing mechanisms, we wish to highlight the strengths and weaknesses in prior sensor works and propose some guiding principles for the development of future probes.

Negative regulation of AMPK signaling by high glucose via E3 ubiquitin ligase MG53.

As a master regulator of metabolism, AMP-activated protein kinase (AMPK) is activated upon energy and glucose shortage but suppressed upon overnutrition. Exaggerated negative regulation of AMPK signaling by nutrient overload plays a crucial role in metabolic diseases. However, the mechanism underlying the negative regulation is poorly understood. Here, we demonstrate that high glucose represses AMPK signaling via MG53 (also called TRIM72) E3-ubiquitin-ligase-mediated AMPKα degradation and deactivation. Specifically, high-glucose-stimulated reactive oxygen species (ROS) signals AKT to phosphorylate AMPKα at S485/491, which facilitates the recruitment of MG53 and the subsequent ubiquitination and degradation of AMPKα. In addition, high glucose deactivates AMPK by ROS-dependent suppression of phosphorylation of AMPKα at T172. These findings not only delineate the mechanism underlying the impairment of AMPK signaling in overnutrition-related diseases but also highlight the significance of keeping the yin-yang balance of AMPK signaling in the maintenance of metabolic homeostasis.

Genetic and environmental sources of familial resemblance in anxiety: a nuclear twin family design.

BACKGROUND: A dominant feature of anxiety disorders is familial aggregation. However, the underlying mechanisms of between- and within-generational anxiety resemblance remain poorly understood. By disentangling the genetic v. environmental sources of familial resemblance in anxiety, we can help prevent within-family transmission of anxiety disorders. Therefore, data from both parents and twins are needed to obtain unbiased and detailed estimations of genetic and environmental sources of similarity between family members. METHODS: We examined data from 991 families with same-sex twins. Trait anxiety in twins was assessed via self-report and parent report, while parental trait anxiety was assessed via self-report. We established a nuclear twin family model and estimated genetic and environmental variances using two survey waves. RESULTS: The results suggested that additive genetic (A), dominant genetic (D), and non-shared environmental (E) influences significantly contributed to trait anxiety, whereas familial environmental influences (F) and passive gene-environment correlations (rGE) did not. Sibling environmental influences (S) were only found in self-report data, and increased when genetic influences decreased from Wave 1 to Wave 2. CONCLUSIONS: Our study highlights the important role of broad heritability in intrafamilial trait anxiety similarity. Parent-child resemblance occurred primarily due to shared genetic makeup rather than direct environmental transmission. Sibling-specific environments, as the only source of shared environments, need further investigation. These findings have both theoretical and practical significance for anxiety disorders. Future research can expand our understanding by examining the gene-environment interplay and sex differences.

The Composition and Diversity of the Rhizosphere Bacterial Community of Ammodendron bifolium Growing in the Takeermohuer Desert Are Different from Those in the Nonrhizosphere.

Soil microorganisms play important roles in vegetation establishment and soil biogeochemical cycling. Ammodendron bifolium is a dominant sand-fixing (i.e., stabilizing sand dunes) and endangered plant in the Takeermohuer Desert, and the bacterial community associated with this plant rhizosphere is still unclear. In this study, we investigated the composition and diversity of the bacterial community from the A. bifolium rhizosphere and bulk soil at different soil depths (i.e., 0-40 cm, 40-80 cm, 80-120 cm) using culture and high-throughput sequencing methods. We preliminarily analyzed the edaphic factors influencing the structure of bacterial communities. The results showed that the high-salinity Takeermohuer Desert has an oligotrophic environment, while the A. bifolium rhizosphere exhibited a relatively nutrient-rich environment due to higher contents of soil organic matter (SOM) and soil alkaline nitrogen (SAN) than bulk soil. The dominant bacterial groups in the desert were Actinobacteria (39.8%), Proteobacteria (17.4%), Acidobacteria (10.2%), Bacteroidetes (6.3%), Firmicutes (6.3%), Chloroflexi (5.6%), and Planctomycetes (5.0%) at the phylum level. However, the relative abundances of Proteobacteria (20.2%) and Planctomycetes (6.1%) were higher in the rhizosphere, and those of Firmicutes (9.8%) and Chloroflexi (6.9%) were relatively higher in barren bulk soil. A large number of Actinobacteria were detected in all soil samples, of which the most abundant genera were Streptomyces (5.4%) and Actinomadura (8.2%) in the bulk soil and rhizosphere, respectively. The Chao1 and PD_whole_tree indices in the rhizosphere soil were significantly higher than those in the bulk soil at the same soil depth and tended to decrease with increasing soil depth. Co-occurrence network analyses showed that the keystone species in the Takeermohuer Desert were the phyla Actinobacteria, Acidobacteria, Proteobacteria, and Chloroflexi. Furthermore, the major edaphic factors affecting the rhizosphere bacterial community were electrical conductivity (EC), SOM, soil total nitrogen (STN), SAN, and soil available potassium (SAK), while the major edaphic factors affecting the bacterial community in bulk soil were distance and ratio of carbon to nitrogen (C/N). We concluded that the A. bifolium rhizosphere bacterial community is different from that of the nonrhizosphere in composition, structure, diversity, and driving factors, which may improve our understanding of the relationship between plant and bacterial communities and lay a theoretical foundation for A. bifolium species conservation in desert ecosystems.

Composition and Distribution Characteristics of Rhizosphere Bacterial Community of Ammodendron bifolium Growing in Takeermohuer Desert Are Different from Those in Non-rhizosphere.

Soil microorganisms play important roles in vegetation establishment and soil biogeochemical cycling. Ammodendron bifolium is a dominant sand-fixing and endangered plant in Takeermohuer Desert, and bacterial community associated with this plant rhizosphere is still unclear. In this study, we studied the composition and diversity of bacterial community from A. bifolium rhizosphere and bulk soil at different soil depths (i.e., 0-40 cm, 40-80 cm, 80-120 cm) using traditional bacterial isolation and high-throughput sequencing approaches, and preliminarily analyzed the edaphic factors influencing the structure of bacterial communities. Results showed that Takeermohuer Desert with high salinity has been an oligotrophic environment, while the rhizosphere exhibited eutrophication resulting from high content SOM (soil organic matter) and SAN (soil alkaline nitrogen) compared with bulk soil. The dominant bacterial groups in the desert were Actinobacteria (39.8%), Proteobacteria (17.4%), Acidobacteria (10.2%), Bacteroidetes (6.3%), Firmicutes (6.3%), Chloroflexi (5.6%), and Planctomycetes (5.0%) at the phyla level. However, the relative abundances of Proteobacteria (20.2%) and Planctomycetes (6.1%) were higher in eutrophic rhizosphere, and Firmicutes (9.8%) and Chloroflexi (6.9%) relatively higher in barren bulk soil. A large number of Actinobacteria were detected in all soil samples, of which the most abundant genus was Streptomyces (5.4%) and Actinomadura (8.2%) in the bulk soil and rhizosphere, respectively. The Chao1 and PD indexes in rhizosphere were significantly higher than those in bulk soil at the same soil depth, and tended to decrease with increasing soil depth. Co-occurrence network analyses showed that the keystone species in Takeermohuer Desert were Actinobacteria, Acidobacteria, Proteobacteria, and Chlorofexi. Furthermore, the major environmental factors affecting rhizosphere bacterial community were EC (electrical conductivity), SOM, STN (soil total nitrogen), SAN, and SAK (soil available potassium), while bulk soil were distance and C/N (STC/STN). We concluded that A. bifolium rhizosphere bacterial community is different from non-rhizosphere in composition, distribution, and environmental influencing factors, which will have important significances for understanding their ecological functions and maintaining biodiversity.

Anatomical distance affects functional connectivity at rest in medicine-free obsessive-compulsive disorder.

BACKGROUND: Brain functional abnormalities at rest have been observed in obsessive-compulsive disorder (OCD). However, whether and how anatomical distance influences functional connectivity (FC) at rest is ambiguous in OCD. METHODS: Using resting-state functional magnetic resonance imaging data, we calculated the FC of each voxel in the whole-brain and divided FC into short- and long-range FCs in 40 medicine-free patients with OCD and 40 healthy controls (HCs). A support vector machine (SVM) was used to determine whether the altered short- and long-range FCs could be utilized to distinguish OCD from HCs. RESULTS: Patients had lower short-range positive FC (spFC) and long-range positive FC (lpFC) in the left precentral/postcentral gyrus (t = -5.57 and -5.43; P < 0.05, GRF corrected) and higher lpFC in the right thalamus/caudate, left thalamus, left inferior parietal lobule (IPL) and left cerebellum CrusI/VI (t = 4.59, 4.61, 4.41, and 5.93; P < 0.05, GRF corrected). Furthermore, lower spFC in the left precentral/postcentral gyrus might be used to distinguish OCD from HCs with an accuracy of 80.77%, a specificity of 81.58%, and a sensitivity of 80.00%. CONCLUSION: These findings highlight that anatomical distance has an effect on the whole-brain FC patterns at rest in OCD. Meanwhile, lower spFC in the left precentral/postcentral gyrus might be applied in distinguishing OCD from HCs.

The expression and prognostic significance of PIK3CB in lung adenocarcinoma.

OBJECTIVE: The aim of this study was to explore the expression and prognostic significance of PIK3CB in lung adenocarcinoma (LUAD) and to analyse the possible molecular mechanism that promotes LUAD development. METHODS: Differences of PIK3CB expression at transcriptional level between LUAD and normal tissues were analysed with the Timer and UALCAN databases. Then, immunohistochemical staining was performed to investigate PIK3CB expression at the protein level, and relationships between PIK3CB and clinical characteristics were accessed. Univariate and multivariate Cox regression were performed to identify the independent prognostic risk factors for LUAD. Genetic alterations were analysed using the cBioPortal database. The main coexpressed genes and enrichment pathways of PIK3CB were estimated with the LinkedOmics database. RESULTS: Compared with normal tissues, PIK3CB was higherly expressed in LUAD at the transcriptional level and protein level, respectively. PIK3CB expression was closely related to prognosis of LUAD patients, and PIK3CB protein expression was associated with lymph node metastasis and pathological differentiation, but not related to sex, age, pleural invasion, vascular invasion, tumour site, tumour size or clinical stage. PIK3CB and tumour size were independent risk factors for LUAD patients. The expression of PIK3CB was negatively correlated with AKT1 and AKT2, but there was no significant correlation with AKT3, and strong positive correlations with ARMC8, DNAJC13 and PIK3R4. The main enrichment pathways of PIK3CB and related genes included adherens junctions and the phosphatidylinositol signalling pathways, ErbB signalling pathways, Hedgehog signalling pathways, and C-type lectin receptor signalling pathways. Therefore, we hypothesized that PIK3CB expression did not promote LUAD development through the classical PI3K/AKT pathway. CONCLUSION: High PIK3CB expression was associated with the development of LUAD and worse prognosis. PIK3CB was an independent risk factor for LUAD patients. Therefore, this study provides a reliable reference for the prognostic assessment and targeted therapy for LUAD patients.

High expression of eIF4E is associated with tumor macrophage infiltration and leads to poor prognosis in breast cancer.

BACKGROUND: The expression and activation of eukaryotic translation initiation factor 4E (eIF4E) is associated with cell transformation and tumor initiation, but the functional role and the mechanism whereby it drives immune cell infiltration in breast cancer (BRCA) remain uncertain. METHODS: Oncomine, Timer and UALCAN were used to analyze the expression of eIF4E in various cancers. PrognoScan, Kaplan-Meier plotter, and GEPIA were utilized to analyze the prognostic value of eIF4E in select cancers. In vitro cell experiments were used to verify the role of eIF4E in promoting the progression of BRCA. ImmuCellAI and TIMER database were used to explore the relationship between eIF4E and tumor infiltrating immune cells. The expression of a macrophage marker (CD68+) and an M2-type marker (CD163+) was evaluated using immunohistochemistry in 50 invasive BRCA samples on tissue microarrays. The Human Protein Atlas (HPA) database was used to show the expression of eIF4E and related immune markers. LinkedOmics and NetworkAnalyst were used to build the signaling network. RESULTS: Through multiple dataset mining, we found that the expression of eIF4E in BRCA was higher than that in normal tissues, and patients with increased eIF4E expression had poorer survival and a higher cumulative recurrence rate in BRCA. At the cellular level, BRCA cell migration and invasion were significantly inhibited after eIF4E expression was inhibited by siRNA. Immune infiltration analysis showed that the eIF4E expression level was significantly associated with the tumor purity and immune infiltration levels of different immune cells in BRCA. The results from immunohistochemical (IHC) staining further proved that the expression of CD68+ and CD163+ were significantly increased and correlated with poor prognosis in BRCA patients (P < 0.05). Finally, interaction network and functional enrichment analysis revealed that eIF4E was mainly involved in tumor-related pathways, including the cell adhesion molecule pathway and the JAK-STAT signaling pathway. CONCLUSIONS: Our study has demonstrated that eIF4E expression has prognostic value for BRCA patients. eIF4E may act as an essential regulator of tumor macrophage infiltration and may participate in macrophage M2 polarization.

Synergistic Promotion Effect of ZnCoS Solid Solution and Co1-xS on Photocatalytic Hydrogen Production of the CdS Composite.

Photocatalytic reactions over effective photocatalysts are attractive to explore clean hydrogen energy from water with the utilization of solar energy. Ternary Co1-xS@ZnCoS/CdS (ZCS/CdS) composites are constructed as photocatalysts through the hydrothermal formation of Co1-xS and ZnCoS nanoparticles on CdS nanorods. Superior to the binary Co1-xS/CdS composite, ZCS/CdS shows the improved photocatalytic activity with a hydrogen production rate of 58.4 mmol·g-1·h-1, which is 31.4 and 2.1 times higher than those of CdS and Co1-xS/CdS, respectively. Different from binary Co1-xS/CdS, the participation of a small amount of zinc favors the formation of ZnCoS solid solution in ZCS/CdS. A synergistic promotion effect of ZnCoS and Co1-xS is confirmed due to tight heterojunctions among Co1-xS, ZnCoS, and CdS in ZCS/CdS. The unique heterostructure of ZCS/CdS benefits its enhanced absorption ability of visible light, accelerating the separation of photoinduced electron-hole pairs and the electron transfer. ZCS/CdS exhibits the strong reduction ability and superior photocatalytic stability due to the role of double Z-scheme electron transfer pathways in the ternary composite. This work provides a suitable way to tune noble metal-free composite photocatalysts for efficient H2 production.

Providing targeted psychological support to frontline nurses involved in the management of COVID-19: An action research.

AIM: To develop and implement a targeted psychological support scheme for frontline nurses involved in the management of coronavirus disease 2019 (COVID-19). BACKGROUND: Nurses play a vital role in managing the ongoing COVID-19 pandemic, while confronting enormous challenges and psychological problems. METHODS: Action research design was adopted to develop and provide a targeted psychological support scheme to 1,496 frontline nurses. Data regarding nurses' feedback were collected from WeChat group chat, letters and comments on theme lectures. Subsequently, qualitative content analysis was conducted using MAXQDA. RESULTS: A targeted psychological support scheme was formed via three action cycles according to nurses' needs. Frontline nurses received psychological assistance from a research team, which offered (1) a sense of belonging, (2) a sense of professional value and pride, and (3) a sense of being protected and confident. CONCLUSION: The researchers successfully provided targeted psychological support to nurses, and nurses were motivated and became more confident when their needs were addressed. IMPLICATIONS FOR NURSING MANAGEMENT: Nurses have various types of psychological needs, which could be addressed by targeted support. It is suggested that nurse managers should identify nurses' needs in real time and provide appropriate support through multidisciplinary collaboration to improve their confidence and enhance their resilience.

Fiber Bragg Grating Sensors for Pile Jacking Monitoring in Clay Soil.

The small deformation of the model pile in a pile jacking test makes its accurate measurement very difficult. Based on the installation method of clamping at both ends, a sensitized miniature fiber Bragg grating (FBG) strain sensor was developed to measure the pile strain of small-size model piles. This study investigated the working principle of the sensitized miniature FBG sensor and analyzed the strain transfer characteristics of the sensor by calibration test. The lateral resistance and the earth plug resistance of the model pile were measured accurately by the grooves embedded in the outer tube of the double-wall opening model pile and the sensors directly pasted on the surface of the inner tube. The results of this study show that the sensitized miniature FBG strain sensor has the advantages of high sensitivity, strong interference resistance, and high test accuracy. The FBG strain sensor was completely fixed on the pile by clamping supports at both ends, and the strain measured using the FBG strain sensor was found to be consistent with the pile deformation.

Test and Study of Pipe Pile Penetration in Cohesive Soil Using FBG Sensing Technology.

In order to examine the applicability of Fiber Bragg Grating (FBG) sensing technology in the static penetration of pipe piles, static penetration tests in clay were conducted using double-wall open and closed model pipe piles. The strain was measured using FBG sensors, and the plug height was measured using a cable displacement sensor. Using one open pile and two closed piles, the difference in pipe pile penetration was compared and analyzed. Based on FBG sensing technology and the strain data, the penetration characteristics of the pipe pile, such as axial force, lateral friction, and driving resistance were examined. Results showed that FBG sensing technology has superior testing performance for the pipe pile penetration process, can accurately reflect the strain time history of pipe piles, and can clearly reflect the penetration process of pipe piles with increasing penetration depth. In addition, the variation law of the characteristics of the jacked pile pile-soil interface was obtained. This test has significance for model tests and the engineering design of pipe piles.

Dynamics of Oxygen-Independent Photocleavage of Blebbistatin as a One-Photon Blue or Two-Photon Near-Infrared Light-Gated Hydroxyl Radical Photocage.

Development of versatile, chemically tunable photocages for photoactivated chemotherapy (PACT) represents an excellent opportunity to address the technical drawbacks of conventional photodynamic therapy (PDT) whose oxygen-dependent nature renders it inadequate in certain therapy contexts such as hypoxic tumors. As an alternative to PDT, oxygen free mechanisms to generate cytotoxic reactive oxygen species (ROS) by visible light cleavable photocages are in demand. Here, we report the detailed mechanisms by which the small molecule blebbistatin acts as a one-photon blue light-gated or two-photon near-infrared light-gated photocage to directly release a hydroxyl radical (•OH) in the absence of oxygen. By using femtosecond transient absorption spectroscopy and chemoselective ROS fluorescent probes, we analyze the dynamics and fate of blebbistatin during photolysis under blue light. Water-dependent photochemistry reveals a critical process of water-assisted protonation and excited state intramolecular proton transfer (ESIPT) that drives the formation of short-lived intermediates, which surprisingly culminates in the release of •OH but not superoxide or singlet oxygen from blebbistatin. CASPT2//CASSCF calculations confirm that hydrogen bonding between water and blebbistatin underpins this process. We further determine that blue light enables blebbistatin to induce mitochondria-dependent apoptosis, an attribute conducive to PACT development. Our work demonstrates blebbistatin as a controllable photocage for •OH generation and provides insight into the potential development of novel PACT agents.

HKOH-1: A Highly Sensitive and Selective Fluorescent Probe for Detecting Endogenous Hydroxyl Radicals in Living Cells.

The hydroxyl radical (. OH), one of the most reactive and deleterious reactive oxygen species (ROS), has been suggested to play an essential role in many physiological and pathological scenarios. However, a reliable and robust method to detect endogenous . OH is currently lacking owing to its extremely high reactivity and short lifetime. Herein we report a fluorescent probe HKOH-1 with superior in vitro selectivity and sensitivity towards . OH. With this probe, we have calibrated and quantified the scavenging capacities of a wide range of reported . OH scavengers. Furthermore, HKOH-1r, which was designed for better cellular uptake and retention, has performed robustly in detection of endogenous . OH generation by both confocal imaging and flow cytometry. Furthermore, this probe has been applied to monitor . OH generation in HeLa cells in response to UV light irradiation. Therefore, HKOH-1 could be used for elucidating . OH related biological functions.

On the hydrodynamics of swimming enzymes.

Several recent experiments suggest that rather generally the diffusion of enzymes may be augmented through their activity. We demonstrate that such swimming motility can emerge from the interplay between the enzyme energy landscape and the hydrodynamic coupling of the enzyme to its environment. Swimming thus occurs during the transit time of a transient allosteric change. We estimate the velocity during the transition. The analysis of such a swimming motion suggests the final stroke size is limited by the hydrodynamic size of the enzyme. This limit is quite a bit smaller than the values that can be inferred from the recent experiments. We also show that one proposed explanation of the experiments based on reaction heat effects can be ruled out using an extended hydrodynamic analysis. These results lead us to propose an alternate explanation of the fluorescence correlation measurements.

WS0701: a novel sedative-hypnotic agent acting on the adenosine system.

To characterize the sedative and hypnotic profile of the novel adenosine derivative ((3S,4R,5R)-3,4-dihydroxy-5-(6-((4-hydroxy-3-methoxybenzyl)amino)-9H-purin-9-yl)tetrahydrofuran-2-yl) methyl diaconate (WS0701), we performed a variety of behavioural tests and investigated the influence of WS0701 on various sleep stages. In mice, WS0701 significantly increased the number of entries and time spent in open arms in the elevated plus maze test, indicating an anxiolytic effect. WS0701 decreased locomotor activity counts and head dips in the hole-board test and enhanced sodium pentobarbital-induced hypnosis. However, WS0701 did not induce the loss of the righting reflex or amnesic effects in behavioural models. In rats, WS0701 exerted a sedative effect and markedly prolonged the time spent in non-rapid-eye-movement sleep, especially slow-wave sleep, but reduced the time spent in rapid-eye-movement sleep (REMS). Pretreatment with the selective adenosine A2a receptor antagonist SCH58261 attenuated the sedative and hypnotic effects of WS0701. WS0701 did not protect mice against picrotoxin-induced seizures, but inhibited adenosine deaminase activity and increased adenosine levels in the frontal cortex and hypothalamus of mice. In conclusion, WS0701 shows anxiolytic, sedative as well as sleep stage alterative effects, which may be related to the adenosine system.

Protective effects of the novel adenosine derivative WS0701 in a mouse model of posttraumatic stress disorder.

AIM: To investigate the effects of the novel N6-substituted adenosine derivative {(2R,3S,4R,5R)-3,4-dihydroxy-5-[6-[(4-hydroxy-3-methoxybenzyl)amino]-9H-purin-9-yl]tetrahydrofuran-2-yl} methyl decanoate (WS0701) on stress-induced excessive fear, anxiety, and cognitive deficits in a mouse model of posttraumatic stress disorder (PTSD). METHODS: Male mice underwent a conditioned foot shock and single prolonged stress procedure to induce PTSD. Contextual/cued fear, elevated plus-maze, open field and novel object recognition tests were conduced to assess PTSD-like behaviors. From d 1, the mice were orally administered WS0701 (7.5, 15, or 30 mg·kg(-1)·d(-1)) or paroxetine (10 mg·kg(-1)·d(-1)) for two weeks. Apoptosis of hippocampal neurons was detected using flow cytometry and TUNEL staining, and expression of Bcl-2 and Bax in the hippocampus was measured with Western boltting and qPCR assays. RESULTS: WS0701 administration significantly alleviated fear, anxious behaviors and memory deficits in the mouse model of PTSD. Furthermore, WS0701 administration significantly reduced the stress-induced apoptosis of hippocampal neurons, and increased the Bcl-2/Bax ratio in the hippocampus. The positive control drug paroxetine exerted similar effects on PTSD-like behaviors and hippocampal neuron apoptosis in the mouse model of PTSD, which were comparable to those caused by the high dose of WS0701. CONCLUSION: WS0701 effectively mitigates stress-induced PTSD-like behaviors in mice, partly via inhibition of neuronal apoptosis in the hippocampus.

Development and Application of Cationic Nile Blue Probes in Live-Cell Super-Resolution Imaging and Specific Targeting to Mitochondria.

Mitochondria are essential organelles involved in various metabolic processes in eukaryotes. The imaging, targeting, and investigation of cell death mechanisms related to mitochondria have garnered significant interest. Small-molecule fluorescent probes have proven to be robust tools for utilizing light to advance the study of mitochondrial biology. In this study, we present the rational design of cationic Nile blue probes carrying a permanent positive charge for these purposes. The cationic Nile blue probes exhibit excellent mitochondrial permeability, unique solvatochromism, and resistance to oxidation. We observed weaker fluorescence in aqueous solutions compared to lipophilic solvents, thereby minimizing background fluorescence in the cytoplasm. Additionally, we achieved photoredox switching of the cationic Nile blue probes under mild conditions. This enabled us to demonstrate their application for the first time in single-molecule localization microscopy of mitochondria, allowing us to observe mitochondrial fission and fusion behaviors. Compared to conventional cyanine fluorophores, this class of dyes demonstrated prolonged resistance to photobleaching, likely due to their antioxidation properties. Furthermore, we extended the application of cationic Nile blue probes to the mitochondria-specific delivery of taxanes, facilitating the study of direct interactions between the drug and organelles. Our approach to triggering cell death without reliance on microtubule binding provides valuable insights into anticancer drug research and drug-resistance mechanisms.

Advances in the Development of Bacterial Bioluminescence Imaging.

Bioluminescence imaging (BLI) is a powerful method for visualizing biological processes and tracking cells. Engineered bioluminescent bacteria that utilize luciferase-catalyzed biochemical reactions to generate luminescence have become useful analytical tools for in vitro and in vivo bacterial imaging. Accordingly, this review initially introduces the development of engineered bioluminescent bacteria that use different luciferase-luciferin pairs as analytical tools and their applications for in vivo BLI, including real-time bacterial tracking of infection, probiotic investigation, tumor-targeted therapy, and drug screening. Applications of engineered bioluminescent bacteria as whole-cell biosensors for sensing biological changes in vitro and in vivo are then discussed. Finally, we review the optimizations and future directions of bioluminescent bacteria for imaging. This review aims to provide fundamental insights into bacterial BLI and highlight the potential development of this technique in the future.

Exploratory Training for Universal Lesion Detection: Enhancing Lesion Mining Quality Through Temporal Verification.

Universal lesion detection (ULD) has great value in clinical practice as it can detect various lesions across multiple organs. Deep learning-based detectors have great potential but require high-quality annotated training data. In practice, due to cost, expertise requirements, and the diverse nature of lesions, incomplete annotations are often encountered. Directly training ULD detectors under this condition can yield suboptimal results. Leading pseudo-label methods rely on a dynamic lesion-mining mechanism operating at the mini-batch level to address the issue of incomplete annotations. However, the quality of mined lesions in this approach is inconsistent across different iterations, potentially limiting performance enhancement. Inspired by the observation that deep models learn concepts with increasing complexity, we propose an innovative exploratory-training-based ULD (ET-ULD) method to assess the reliability of mined lesions over time. Specifically, we employ a teacher-student detection model, the teacher model is used to mine suspicious lesions, which are combined with incomplete annotations to train the student model. On top of that, we design a bounding-box bank to record the mining timestamps. Each image is trained in several rounds, allowing us to get a sequence of timestamps for the mined lesions. If a mined lesion consistently appears in the timestamp sequence, it is likely to be a true lesion, otherwise, it may just be a noise. This serves as a crucial criterion for selecting reliable mined lesions for subsequent retraining. Our experimental results confirm the effectiveness of ET-ULD, showcasing its ability to surpass existing state-of-the-art methods on two distinct lesion image datasets. Notably, on the DeepLesion dataset, ET-ULD achieved a significant enhancement, outperforming the previous leading method by 5.4% in Average Precision (AP), thus demonstrating its superior performance.