Enabling Efficient Anchoring-Conversion Interface by Fabricating Double-Layer Functionalized Separator for Suppressing Shuttle Effect.

Lithium-sulfur batteries (LiSBs) with high energy density still face challenges on sluggish conversion kinetics, severe shuttle effects of lithium polysulfides (LiPSs), and low blocking feature of ordinary separators to LiPSs. To tackle these, a novel double-layer strategy to functionalize separators is proposed, which consists of Co with atomically dispersed CoN4 decorated on Ketjen black (Co/CoN4@KB) layer and an ultrathin 2D Ti3C2Tx MXene layer. The theoretical calculations and experimental results jointly demonstrate metallic Co sites provide efficient adsorption and catalytic capability for long-chain LiPSs, while CoN4 active sites facilitate the absorption of short-chain LiPSs and promote the conversion to Li2S. The stacking MXene layer serves as a microscopic barrier to further physically block and chemically anchor leaked LiPSs from the pores and gaps of the Co/CoN4@KB layer, thus preserving LiPSs within efficient anchoring-conversion reaction interfaces to balance the accumulation of "dead S" and Li2S. Consequently, with an ultralight loading of Co/CoN4@KB-MXene, the LiSBs exhibit amazing electrochemical performance even under high sulfur loading and lean electrolyte, and the outperforming performance for lithium-selenium batteries (LiSeBs) can also be achieved. This work exploits a universal and effective strategy of a double-layer functionalized separator to regulate the equilibrium adsorption-catalytic interface, enabling high-energy and long-cycle LiSBs/LiSeBs.

Transcriptome profiling reveals the protective mechanism of sulfated Cyclocarya paliurus polysaccharides against oxidative damage of IEC-6 cell.

Our previous studies have shown that sulfated Cyclocarya paliurus polysaccharides (SCP3) can alleviate intestinal oxidative stress (OS) damage by improving the antioxidant capacity of the intestine, but its mechanism still needs further exploration. This study aimed to reveal the possible underlying protective mechanism of SCP3 against OS damage of intestinal epithelial cells (IEC-6) based on transcriptome profiling. The results showed that SCP3 could increase the activity of superoxide dismutase and reduce the production of malondialdehyde and reactive oxygen species. In addition, the SCP3 could also alleviate the H2O2-induced high apoptosis rate and mitochondrial membrane potential decrease in IEC-6 cells. RNA-sequencing results showed that there were 2152 differentially expressed genes between the control group and the SCP3 group, and the mitogen-activated protein kinases (MAPK) and PI3K-Akt signaling pathways are the main signaling pathways that contributed to SCP3 protecting IEC-6 cells from OS damage. In summary, the SCP3 plays a role in improving intestinal cell damage by inhibiting OS, which may be closely related to the PI3K/Akt and MAPK signaling pathways. PRACTICAL APPLICATION: This study provides a theoretical basis for the practical application of Cyclocarya paliurus polysaccharides as an antioxidant ingredient in auxiliary medicines and functional foods.

[Coblation-assisted endoscopic excision of juvenile nasopharyngeal angiofibroma and outcomes].

Objective:To summarize the procedures and efficacy of surgical treatment for Andrew stage Ⅰ-Ⅲ juvenile nasopharyngeal angiofibroma（JNA）. Methods:A total of 12 patients with JNA who underwent surgery from 2016 to 2021 were enrolled, including 1 case in stage Ⅰ, 3 cases in stage Ⅱ, and 8 cases in stage Ⅲ. JNA was resected by transnasal endoscopic approach alone, or combined with transoral approach or Caldwell-Luc approach was performed. Results:Eleven cases underwent complete resection without recurrence and 1 case had residual tumor. There were no serious complications. The median intraoperative blood loss was 200 mL, and 1 patient received blood transfusion. The median operative time was 110 minutes. Conclusion:JNA in Andrew stage Ⅰ-Ⅲ can be quickly and completely resected by standardized surgical procedures using endoscopy and coblation technology.

Migrasome, a migration-dependent organelle.

Migrasomes are organelles produced by migrating cells that form on retraction fibers and are released during cell migration. Migrasomes are involved in physiological and pathological processes such as intercellular communication, cell homeostasis maintenance, signal transduction, disease occurrence and development, and cancer metastasis. In addition, methods and techniques for studying migrasomes are constantly evolving. Here, we review the discovery, formation process, regulation, and known functions of migrasomes, summarize the commonly used specific markers of migrasomes, and the methods for observing migrasomes. Meanwhile, this review also discusses the potential applications of migrasomes in physiological processes, disease diagnosis, treatment, and prognosis, and looks forward to their wider application in biomedicine. In addition, the study of migrasomes will also reveal a new perspective on the mechanism of intercellular communication and promote the further development of life science.

Modular Cascade of Flow Reactors: Continuous Flow Synthesis of Water-Insoluble Diazo Dyes in Aqueous System.

Continuous flow synthesis is pivotal in dye production to address batch-to-batch variations. However, synthesizing water-insoluble dyes in an aqueous system poses a challenge that can lead to clogging. This study successfully achieved the safe and efficient synthesis of azo dyes by selecting and optimizing flow reactor modules for different reaction types in the two-step reaction and implementing cascade cooperation. Integrating continuous flow microreactor with continuous stirred tank reactor (CSTR) enabled the continuous flow synthesis of Sudan Yellow 3G without introducing water-soluble functional groups or using organic solvents to enhance solubility. Optimizing conditions (acidity/alkalinity, temperature, residence time) within the initial modular continuous flow reactor resulted in a remarkable 99.5% isolated yield, 98.6 % purity, and a production rate of 2.90 g h-1. Scaling-up based on different reactor module characteristics further increased the production rate to 74.4 g h-1 while maintaining high yield and purity. The construction of this small 3D-printing modular cascaded reactor and process scaling-up provide technical support for continuous flow synthesis of water-insoluble dyes, particularly high-market-share azo dyes. Moreover, this versatile methodology proves applicable to continuous flow processes involving various homogeneous and heterogeneous reaction cascades.

Hypoxic environment promotes angiogenesis and bone bridge formation by activating Notch/RBPJ signaling pathway in HUVECs.

After epiphyseal fracture, the epiphyseal plate is prone to ischemia and hypoxia, leading to the formation of bone bridge and deformity. However, the exact mechanism controlling the bone bridge formation remains unclear. Notch/RBPJ signaling axis has been indicated to regulate angiogenesis and osteogenic differentiation. Our study aims to investigate the mechanism of bone bridge formation after epiphyseal plate injury, and to provide a theoretical basis for new therapeutic approaches to prevent the bone bridge formation. The expression of DLL4 and RBPJ was significantly up-regulated in HUVECs after ischemia and hypoxia treatment. Notch/RBPJ pathway positively regulated the osteogenic differentiation of BMSCs. HUVECs can induce osteogenic differentiation of BMSCs under ischemia and hypoxia. Notch/RBPJ pathway is involved in the regulation of the trans-epiphyseal bridge formation. Notch/RBPJ in HUVECs is associated with osteogenic differentiation of BMSCs and may participate in the regulation of the bone bridge formation across the epiphyseal plate.

High-fidelity intracellular imaging of multiple miRNAs via stimulus-responsive nanocarriers and catalytic hairpin assembly.

An advanced nanoplatform was developed by integrating catalytic hairpin assembly (CHA) with glutathione-responsive nanocarriers, enabling superior imaging of dual cancer-related miRNAs. Two distinct CHA circuits for the sensing of miRNA-21 and miRNA-155 were functionalized on biodegraded MnO2. In the presence of GSH and the corresponding miRNAs, the degraded MnO2 released the DNA cargos, activating the CHA circuits and recovering the fluorescence. This approach offers a reliable sensing performance with highly selective cell-identification capacity, positioning it as a pivotal tool for imaging multiple biomarkers in living cells.

Outcomes of endoscopic sinus surgery in patients with central compartment atopic disease.

Background: Central compartment atopic disease (CCAD) is a subtype of chronic rhinosinusitis (CRS). Research focusing on the endoscopic sinus surgery (ESS) outcomes of CCAD is limited. This study aimed to evaluate the outcomes of ESS in CCAD and compared to 2 following subtypes: chronic rhinosinusitis with nasal polyps (CRSwNP) and concomitant polypoid disease in the central compartment (CRSwNP/CC) and CRSwNP not otherwise specified (CRSwNP NOS). Methods: This case-control study enrolled patients with bilateral CRSwNP who underwent ESS and had at least 1 year of follow-up. Patients were classified into CCAD, CRSwNP/CC, and CRSwNP NOS. The demographic data, preoperative disease severity, and surgery outcomes, including CRS control status, endoscopic score, and symptom scores at 1 year postoperatively, were collected. We defined well controlled and partly controlled as appropriate disease control. Results: This study screened 259 patients and enrolled 138 patients with complete medical records and 1-year follow-up (CCAD N = 51, CRSwNP/CC N = 55, CRSwNP NOS N = 32). Among them, appropriate disease control was achieved in 84.3% of patients (43/51) in the CCAD group, 69.1% (38/55) in the CRSwNP/CC group, and 93.7% (30/32) in the CRSwNP NOS group (P = 0.029). Then we performed post-hoc analysis using appropriate disease control and uncontrolled. There was a significant difference between CRSwNP/CC and CRSwNP NOS (P = 0.007), but no significant difference compared CCAD group to CRSwNP/CC group (P = 0.065) and CRSwNP NOS group (P = 0.199). There were significant differences in endoscopic E-score among groups (P < 0.001). In post-hoc analysis, we found that CRSwNP/CC (Median [IQR], 33.32 [42.14]) had a significantly worse E-score than CCAD (8.33 [16.67]) and CRSwNP NOS (4.17 [8.30]). Also, postoperative olfactory visual analog scale (VAS) scores significantly differed among groups (P = 0.043). However, post-hoc analysis showed no difference between any 2 groups. There were no differences in postoperative VAS scores of obstruction (P = 0.159), rhinorrhea (P = 0.398), and headache/facial pain (P = 0.092). Conclusion: Most CCAD patients had good surgical outcomes 1 year after surgery. Meanwhile, the CRSwNP/CC group had the fewest patients under appropriate disease control.

Percutaneous K-wire reduction and cast immobilization for severely displaced radial neck fractures in children.

The purpose of this study was to compare outcomes between percutaneous K-wire reduction cast immobilization (PKRC) and percutaneous K-wire reduction elastic intramedullary nailing combined with cast immobilization (PKRNC) for the treatment of radial neck fractures in children. This was a retrospective analysis of 62 radial neck fractures in children treated with PKRC or PKRNC. Thirty-one children were treated with percutaneous K-wire reduction, K-wire removal after reduction, and cast immobilization while 31 radial neck fractures in controls were managed using PKRNC. There were no significant differences between PKRC and PKRNC with regard to preoperative angulation ( P  = 0.556). The operation time in the PKRC group was significantly shorter than that of the PKRNC group ( P  = 0.023). There was no significant difference in the displacement angle when compared between the two groups on the first day and 1 month after surgery ( P  = 0.617, 0.72). The Mayo elbow performance score of the elbow joint function did not differ significantly between the two groups ( P  = 0.587). Although the hospital stay was not significantly different between groups (4.81 ±â€…1.07 vs. 4.16 ±â€…1.59 days; P  = 0.067), the PKRNC group required a second hospitalization to remove the elastic intramedullary nail 3 months after the operation. PKRC and PKRNC both achieved satisfactory outcomes for radial neck fractures in children. The operation time in the PKRC group was significantly lower than in the PKRNC group. PKRC does not require reoperation to remove internal fixation. Therefore, PKRC is recommended for radial neck fractures in children.

Preliminary fracture reduction in children with type III supracondylar humerus fractures during the COVID-19 pandemic.

During the COVID-19 pandemic, the time elapsed from injury to definitive surgery necessitated delay in type III pediatric supracondylar humerus fractures. Preliminary fracture reduction was recommended in these fractures while waiting for operative treatment. The purpose of this study was to evaluate whether preliminary reduction afforded a better treatment experience and improved outcomes. A retrospective cohort analysis of 161 type III supracondylar humerus fractures compared treatment with preliminary closed fracture reduction and delayed percutaneous pin placement (110 children) to delayed combined closed reduction and pin placement (51 children) in a children's medical center. Of the preliminary reduction group, 22 (20%) required analgesic pain relief, compared to 18 (35%) in the non-preliminary reduction group ( P  = 0.037), and the preliminary reduction group had statistically less pain (assessed using the Faces Pain Scale-Revised rating) the first night after injury and the first-night post-CRPP ( P  = 0.019, P  = 0.008). Cast splitting was more frequent in the non-preliminary reduction group, 11 patients (22%) than in the preliminary reduction group, 10 patients (9%; P  = 0.029). The operative times in the preliminary reduction group were shorter ( P  < 0.001). If delay is necessary for complete repair of type III supracondylar humerus fractures, a preliminary fracture reduction with a temporary cast can be recommended, as these children will experience a more comfortable interval, with less swelling and pain, and potentially a shorter operation. Level of Evidence: Level III-therapeutic study.

Unraveling the Intricate Roles of Exosomes in Cardiovascular Diseases: A Comprehensive Review of Physiological Significance and Pathological Implications.

Exosomes, as potent intercellular communication tools, have garnered significant attention due to their unique cargo-carrying capabilities, which enable them to influence diverse physiological and pathological functions. Extensive research has illuminated the biogenesis, secretion, and functions of exosomes. These vesicles are secreted by cells in different states, exerting either protective or harmful biological functions. Emerging evidence highlights their role in cardiovascular disease (CVD) by mediating comprehensive interactions among diverse cell types. This review delves into the significant impacts of exosomes on CVD under stress and disease conditions, including coronary artery disease (CAD), myocardial infarction, heart failure, and other cardiomyopathies. Focusing on the cellular signaling and mechanisms, we explore how exosomes mediate multifaceted interactions, particularly contributing to endothelial dysfunction, oxidative stress, and apoptosis in CVD pathogenesis. Additionally, exosomes show great promise as biomarkers, reflecting differential expressions of NcRNAs (miRNAs, lncRNAs, and circRNAs), and as therapeutic carriers for targeted CVD treatment. However, the specific regulatory mechanisms governing exosomes in CVD remain incomplete, necessitating further exploration of their characteristics and roles in various CVD-related contexts. This comprehensive review aims to provide novel insights into the biological implications of exosomes in CVD and offer innovative perspectives on the diagnosis and treatment of CVD.

Epidemiological characteristics and temporal-spatial clustering analysis on human brucellosis in Jiangsu Province, 2006-2021.

The marked increase in the incidence rate of brucellosis is a serious public health concern in Jiangsu Province. However, its temporal and spatial distribution has not been studied in depth. The main purpose of this study is to depict the demographic, temporal and spatial distribution patterns and clustering characteristics of brucellosis cases in Jiangsu Province, China, from 2006 to 2021 to develop and implement effective scientific prevention and control strategies. Data for human brucellosis cases in Jiangsu Province from 2006 to 2021 were obtained from the Nationwide Notifiable Infectious Diseases Reporting Information System (NIDRIS). Spatial autocorrelation analysis and temporal-spatial scan statistics were used to identify potential changes in the spatial and temporal distributions of human brucellosis in Jiangsu Province. During the years 2006-2021, 1347 brucellosis cases were reported in Jiangsu Province, with an average annual incidence rate of 0.1036 per 100,000 individuals. Middle-aged and elderly individuals (aged 40-69 years) were the main infected populations, accounting for 69.72% (939/1347) of all reported cases. The incidence of brucellosis in Jiangsu showed a long-term increasing trend and displayed pronounced seasonal variations, with the peak occurring between April and June annually. The incidence gradually expanded from the northern and southern areas to the central areas between 2006 and 2021. Global spatial autocorrelation analysis demonstrated a positive correlation in the incidence of brucellosis between 2008 and 2012-2021. Temporal-spatial clustering analysis showed that the primary cluster was detected in the northern, highly endemic regions of Jiangsu, and the three secondary clusters were in areas where there had been outbreaks of brucellosis. Human brucellosis remains a serious public health issue in Jiangsu Province. Northern and southern Jiangsu regions, with high rates of brucellosis, may require special plans and measures to monitor and control the disease. Additionally, the capacity to respond to outbreaks in high-incidence areas should be improved to prevent further brucellosis outbreaks.

Annual incidence and fatality rates of notifiable infectious diseases in southeast China from 1950 to 2022 and relationship to socioeconomic development.

Background: Over the past 70 years, China has advanced significantly in the prevention and treatment of infectious diseases while simultaneously undergoing a socioeconomic transformation, making it a useful source of data for analysing relationships between public health policy and the control of infectious diseases. Methods: We collected data on the incidence of notifiable infectious diseases and associated fatalities in Jiangsu province in southeast China from the Provincial Center for Disease Control and Prevention, Provincial Institute of Parasitic Diseases, and the Nationwide Notifiable Infectious Diseases Reporting Information System. We compared data from different historical periods using descriptive statistical methods, joinpoint regression, and correlation analysis. Results: During 1950-2022, 75 754 008 cases of 46 notifiable infectious diseases were reported in Jiangsu, with an average annual incidence was 1679.49 per 100 000 population and a fatality rate of 1.82 per 1000 persons. The incidence of classes A-B decreased (average annual percent change (AAPC) = -2.1) during the entire study period, while the incidence of class C increased (AAPC = 10.8) after 2004. The incidence of intestinal diseases (AAPC = -4.4) and vector-borne and zoonotic diseases (AAPC = -8.1) decreased rapidly, while the incidence of sexually transmitted and blood-borne diseases (AAPC = 1.8) increased. The number of medical and health institutions and the per capita gross domestic product correlated negatively with the annual incidence of diseases in classes A-B, but not with fatality rates. Conclusions: Although the annual incidence of many severe infectious diseases has decreased in Jiangsu since 1950, the incidence of sexually transmitted and blood-borne diseases increased. Socioeconomic growth and sustainable investment in health systems are associated with better control of infectious diseases.

Conditional replication and secretion of hepatitis B virus genome uncover the truncated 3' terminus of encapsidated viral pregenomic RNA.

IMPORTANCE: The biogenesis and clinical application of serum HBV pgRNA have been a research hotspot in recent years. This study further characterized the heterogeneity of the 3' terminus of capsid RNA by utilizing a variety of experimental systems conditionally supporting HBV genome replication and secretion, and reveal that the 3' truncation of capsid pgRNA is catalyzed by cellular ribonuclease(s) and viral RNaseH at positions after and before 3' DR1, respectively, indicating the 3' DR1 as a boundary between the encapsidated portion of pgRNA for reverse transcription and the 3' unprotected terminus, which is independent of pgRNA length and the 3' terminal sequence. Thus, our study provides new insights into the mechanism of pgRNA encapsidation and reverse transcription, as well as the optimization of serum HBV RNA diagnostics.

Analysis of the spatial-temporal distribution characteristics of hepatitis E in Jiangsu province from 2005 to 2020.

Objective: This study attempts to analyze the spatial clustering and spatial-temporal distribution characteristics of hepatitis E (HE) at the county (city and district) level in Jiangsu province to provide a scientific basis for the prevention and control of HE. Method: The information on HE cases reported in the Chinese Center for Disease Control and Prevention Information System from 2005 to 2020 was collected for spatial autocorrelation analysis and spatial-temporal clustering analysis. Result: From 2005 to 2020, 48,456 HE cases were reported in Jiangsu province, with an average annual incidence rate of 3.87/100,000. Male cases outnumbered female cases (2.46:1), and the incidence was highest in the 30-70 years of age group (80.50%). Farmers accounted for more than half of all cases (59.86%), and in terms of the average annual incidence, the top three cities were all in Zhenjiang city. Spatial autocorrelation analysis showed that Global Moran's I of HE incidence varied from 0.232 to 0.513 for the years. From 2005 to 2020, 31 counties (cities and districts) had high and statistically significant HE incidence, and two clustering areas were detected by spatial-temporal scanning. Conclusion: HE incidence in Jiangsu province from 2005 to 2020 was stable, with age and gender differences, regional clustering, and spatial-temporal clustering. Further investigation of HE clustering areas is necessary to formulate corresponding targeted prevention and control measures.

Enable Multi-Stimuli-Responsive Biomimetic Actuation with Asymmetric Design of Graphene-Conjugated Conductive Polymer Gradient Film.

In this paper, multiresponsive actuators based on asymmetric design of graphene-conjugated poly(3,4-ethylene dioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) gradient films have been developed by a simple drop casting method. The biomimetic actuation is attributed to the hygroscopic expansion property of PEDOT:PSS and the gradient distribution of graphene sheets within the film, which resembles the hierarchical swelling tissues of some plants in nature. Graphene-conjugated PEDOT:PSS (GCP) actuators exhibit reversible bending behavior under multistimuli such as moisture, organic vapor, electrothermal, and photothermal heating. Noticeably, the bending curvature reaches 2.15 cm-1 under applied voltage as low as 1.5 V owing to the high electrical conductivity of GCP actuator. To mimic the motions of nyctinastic plants, a GCP artificial flower that spreads its petals under sunlight illumination has been fabricated. GCP actuators have been also demonstrated as intelligent light-controlled switches for light-emitting diodes and smart curtains for thermal management. Not only do the GCP gradient films exhibit potential applications in flexible electronics and energy harvesting/storage devices but also the facile fabrication of multiresponsive GCP actuators may shed light on the development of soft robotics, artificial muscles, wearable electronics, and smart sensors.

Imaging Investigation of Hepatocellular Carcinoma Progress via Monitoring γ-Glutamyltranspeptidase Level with a Near-Infrared Fluorescence/Photoacoustic Bimodal Probe.

Hepatocellular carcinoma (HCC) is one of the main principal causes of cancer death, and the late definite diagnosis limits therapeutic approaches in time. The early diagnosis of HCC is essential, and the previous investigations on the biomarkers inferred that the γ-glutamyltranspeptidase (GGT) level could indicate the HCC process. Herein, a near-infrared fluorescence/photoacoustic (NIRF/PA) bimodal probe, CySO3-GGT, was developed for monitoring the GGT level and thus to image the HCC process. After the in-solution tests, the bimodal response was convinced. The various HCC processes were imaged by CySO3-GGT at the cellular level. Then, the CCl4-induced HCC (both induction and treatment) and the subcutaneous and orthotopic xenograft mice models were selected. All throughout the tests, CySO3-GGT achieved NIRF and PA bimodal imaging of the HCC process. In particular, CySO3-GGT could effectively realize 3D imaging of the HCC nodule by visualizing the boundary between the tumor and the normal tissue. The information here might offer significant guidance for the dynamic monitoring of HCC in the near future.

DNA-modulated single-atom nanozymes with enhanced enzyme-like activity for ultrasensitive detection of dopamine.

Despite the current progress in optimizing and tailoring the performance of nanozymes through structural and synthetic adaptation, there is still a lack of dynamic modulation approaches to alter their catalytic activity. Here, we demonstrate that DNA can act as an auxiliary regulator via a straightforward incubation method with Fe-N-C single-atom nanozymes (SAzymes), causing a leap in the enzyme-like activity of Fe-N-C from moderate to a higher level. The DNA-assisted enhancement is attributed to the increased substrate affinity of Fe-N-C nanozymes through electrostatic attraction between the substrate and DNA. Based on the prepared DNA/Fe-N-C system, colorimetric sensors for dopamine (DA) detection were constructed. Surprisingly, the incorporation of DNA not only enabled the detection of DA in a low concentration range, but also greatly improved the sensitivity with a 436-fold decrease in detection limit. The quantitative determination of DA was achieved in two-segment linear ranges of 0.01-4 µM and 5-100 µM with an ultralow detection limit of 9.56 nM. The DNA/Fe-N-C system shows superior performance compared to the original Fe-N-C system, making it an ideal choice for nanozyme-based biosensors. This simple design approach has paved the way for enhancing nanozyme activity and is expected to serve as a general strategy for optimizing biosensor performance.

Two-photon excited luminescence of structural light enhancement in subwavelength SiO2 coating europium ion-doped paramagnetic gadolinium oxide nanoparticle and application for magnetic resonance imaging.

BACKGROUND: Oxides of lanthanide rare-earth elements show great potential in the fields of imaging and therapeutics due to their unique electrical, optical and magnetic properties. Oxides of lanthanide-based nanoparticles enable high-resolution imaging of biological tissues by magnetic resonance imaging (MRI), computed tomography (CT) imaging, and fluorescence imaging. In addition, they can be used to detect, treat, and regulate diseases by fine-tuning their structure and function. It remains challenging to achieve safer, efficient, and more sensitive nanoparticles for clinical applications through the structural design of functional and nanostructured rare-earth materials. RESULT: In this study, we designed a mesoporous silica-coated core-shell structure of europium oxide ions to obtain near-infrared two-photon excitation fluorescence while maintaining high contrast and resolution in MRI. We designed enhanced 800 nm photoexcitation nanostructures, which were simulated by the finite-difference method (FDM) and finite-difference time-domain method (FDTD). The nanoparticle structure, two-photon absorption, up-conversion fluorescence, magnetic properties, cytotoxicity, and MRI were investigated in vivo and in vitro. The nanoparticle has an extremely strong optical fluorescence response and multiple excitation peaks in the visible light band under the 405 nm continuous-wave laser excitation. The nanoparticle was found to possess typical optical nonlinearity induced by two-photon absorption by ultrafast laser Z-scan technique. Two-photon excited fluorescence of visible red light at wavelengths of 615 nm and 701 nm, respectively, under excitation of the more biocompatible near-infrared (pulsed laser at 800 nm). In an in vitro MRI study, a T1 relaxation rate of 6.24 mM-1 s-1 was observed. MRI in vivo showed that the nanoparticles could significantly enhance the signal intensity in liver tissue. CONCLUSIONS: These results suggest that this sample has applied potential in visible light fluorescence imaging and MRI.

Endogenous glutathione-activated DNA nanoprobes for spatially controllable imaging of microRNA in living cells.

A DNA nanoprobe, activated by glutathione (GSH), was designed to enable spatially selective sensing and imaging of miRNA in living cells. The nanoprobe was constructed using nano-sized metal-organic frameworks (MOFs) and DNA hairpin probes tethered to the surface of the MOFs, with the loop portion of the hairpin structure containing a disulfide bond. Cleavage of the disulfide bond by GSH triggers a strand-displacement reaction with target miRNAs, facilitating in situ readout of the fluorescence signal. The synergy of endogenous GSH activation and MOF improves the spatial resolution of miRNA detection and imaging.