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Levofloxacin (LVX) is difficult to be naturally degraded by microorganisms in water, and its residues in water will pose significant risks to human health and ecological environment. In this study, Bi12O17Cl2 was used as the main body, Bi12O17Cl2/GO/Co3O4 composite photocatalyst was prepared by pyrolysis of zeolitic imidazolate framework-67 (ZIF-67) combined with in-situ precipitation method and used to degrade LVX. A sequence of characterizations shows that addition of Co3O4 and graphene oxide (GO) increases the visible light response range, improves the separation efficiency of photogenerated electrons and holes (e--h+) of photocatalyst, and thus improves the degradation efficiency of LVX. Under the optimal reaction conditions, the LVX degradation rate of Bi12O17Cl2/1.5GO/7.5Co3O4 can reach 91.2 % at 120 min, and its reaction rate constant is the largest (0.0151 min-1), which is 2.17, 13.14 and 1.53 times that of Bi12O17Cl2, Co3O4 and Bi12O17Cl2/7.5Co3O4, respectively, showing better photocatalytic performance. Simultaneously, the recycling stability of Bi12O17Cl2/1.5GO/7.5Co3O4 was also verified. The capture experiments and electron EPR test results showed that superoxide radicals (â¢O2-) and photogenerated holes (h+) were the primary active substances in the reaction process. Finally, combined with HPLC-MS results, the photocatalytic degradation pathway of LVX was derived. This work will provide a theoretical basis for the design of Metal Organic Frameworks (MOFs)-derivative modified Bi12O17Cl2-based photocatalysts.
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Ozone (O 3), a prevalent atmospheric pollutant, can induce lung injury. However, the molecular mechanisms of O 3-induced acute lung inflammatory injury remain unclear. In this study, we investigate the abnormal changes in and molecular mechanism of mitochondrial homeostasis in alveolar macrophages (AMs) in O 3-induced acute lung inflammatory injury mice. Mitochondria and mitochondrial reactive oxygen species (mtROS) are labeled with Mito-Tracker® Deep Red and MitoSOX Red, respectively. Mitochondrial DNA (mtDNA) in AMs from the bronchoalveolar lavage fluid (BALF) is detected via real-time PCR, and the expressions of mitochondrial fusion/fission-related and biogenesis-related proteins in AMs are determined via immunofluorescence staining. Our data show that in O 3-induced acute lung inflammatory injury mice, the number of AMs and the protein expression of the NLRP3 inflammasome complex in the lung tissue are increased. In AMs from O 3-exposed mice, the number of mitochondria, mtROS, and fission-related protein DRP1 are increased, but the levels of Na +-K +-ATPase, fusion-related protein OPA1, biogenesis-related protein NRF1 and mtDNA are significantly decreased. Compared with that in O 3-exposed WT mice, lung inflammation is attenuated, especially the indicators of mitochondrial homeostatic imbalance in AMs, which are alleviated in NLRP3 â/â and Caspase-1 â/â mice after O 3 exposure. These findings indicate that the NLRP3 inflammasome-mediated imbalance in mitochondrial homeostasis in AMs contributes to O 3-induced acute lung inflammatory injury. This study may provide a new target for the prevention of lung inflammation induced by O 3.
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Grafting lignin extracted from pulping black liquor onto hydrogel not only endows hydrogel with strong adsorption capacity, but also realizes the high value utilization of lignin, thereby alleviating the environmental pressure caused by the exhaust gas generated by direct combustion of black liquor. However, those lignin fragments have lost generous active functional groups as the high temperature polycondensation during industrial production, restricting the improvement of lignin-based hydrogel adsorption capacity. Herein, we propose a strategy combining amination and oxidation to prepare lignin derivatives with low molecular weight and high activity groups. The introduced amino groups promote the Cα-Cß cleavage of ß-O-4 unit and the oxidation treatment converts S-unit hydroxyl to carboxyl. The hydrogel obtained by grafting aminated-oxidized-lignin shows satisfactory adsorption performance with a methylene blue adsorption capacity of 697.47 mg/g (vs. 195.12 mg/g for pristine hydrogel). The retention ability has also been greatly improved that only 0.43 % of the adsorbed methylene blue is released even after 96 h (vs. 5 % within just 12 h for pristine hydrogel). This work not only provides a new strategy for the high-value utilization of biomass resources, but also offers a new idea for the preparation of hydrogels with high adsorption performance.
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Oceans and rivers are predominant sinks, reservoirs, and carriers of plastic debris that are proposed to be long term sources of a variety of contaminants in the environments. This research unveiled kinetics of chemical releases from plastic debris in freshwater and marine environment via artificial river water (ARW) and seawater (ASW) in combination of nontarget screening. Chemical leaching from PVC cord particles in the ARW and ASW basically followed the first order kinetics, reaching pseudo-equilibrium in 30d and 14d, respectively, associated with both particle surface - water partitioning and inner-particle diffusion of chemicals. Dissolved organic carbon, finer size, and weathering of plastic particles might enhance whereas metal ions potentially hinder chemical releases from plastic debris in waters, respectively. Salinity and pH showed moderate effects on chemical leaching. In addition, chemicals' physiochemical properties might also affect their leaching behavior. Hundreds to thousands of chemicals would be released from plastic debris in days once entering waters, among which > 80% were unknown with rare or no information about eco-toxicity and environmental fate, posing unpredicted risks to the environment. Furthermore, new chemicals may keep being released with increasing weathering and extending retention time of plastics in waters, leading to increases in both numbers and complexities of released chemicals. Chemical leaching from plastics showed product-dependence and certain differences in freshwater and seawater. Large numbers of unknown chemicals potentially released from plastic debris in rivers, lakes, and oceans and subsequent environmental risks warrant in-depth research.
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BACKGROUND: Previous studies have demonstrated that the addition of chitosan can improve the quality and functional properties of meat products. However, the underlying mechanism remains unclear. In this study, the effect and mechanism of the addition of chitosan on the gel properties of myofibrillar protein (MP) were investigated. RESULTS: The results indicated that the gel strength and the water-holding capacity of MP-chitosan gel increased significantly when chitosan was added at 2.5-10 mg mL-1. Myofibrillar protein samples with 10 mg mL-1 added chitosan exhibited the highest elasticity and viscosity during gel formation and strengthening. The addition of chitosan also caused a modification in both the secondary and tertiary structure of MP, resulting in an enhanced exposure of hydrophobic and sulfhydryl groups in comparison with the control. Chitosan inhibited the conversion of immobilized water into free water and the formation of water channels during the thermal gelation process of MP. The denaturation enthalpy (ΔH) of myosin decreased as the concentration of chitosan exceeded 5 mg mL-1. The microstructure showed that the incorporation of chitosan (5-10 mg mL-1) facilitated the formation of compact and well organized MP gel networks. CONCLUSION: The addition of chitosan can enhance the functional properties of meat protein and facilitate heat-induced gelation, making it a promising ingredient for improving the quality of processed meat products. © 2024 Society of Chemical Industry.
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The extra domain B splice variant of fibronectin (EDB-FN), which is overexpressed in several cancers, is an approved diagnostic and therapeutic target of cancers. The aim of this study was to evaluate the EDB-FN-targeting peptide EDBp as a noninvasive imaging modality for molecular imaging of breast cancer in mice. Western blot, flow cytometry and immunofluorescence were used to assess the expression level of EDB-FN and its binding to EDRp in MCF7, SKBR3, 4T1, EMT6, MDA-MB-231 and MDA-MB-453 cells. Establishment MDA-MB-231-luc cells-based subcutaneous tumor model mice or pulmonary metastasis model mice. The EDRp molecular probes to perform fluorescent probes for near-infrared fluorescence (NIRF)·and PET imaging of model mice. Our results demonstrate that EDBp-Cy5 had a strong binding ability to the MDA-MB-231 cells and exhibited specific tumor accumulation in MDA-MB-231 subcutaneous and pulmonary metastasis model mice. Importantly, the EDBp peptide-based radiotracer [18F]-AlF-NOTA-EDBp provided excellent diagnostic value for positron emission tomography (PET) imaging of breast cancer, especially in subcutaneous model mice. The uptake of [18F]-AlF-NOTA-EDBp in subcutaneous tumors (6.53 ± 0.89%, ID/g) was unexpectedly higher than that in the kidney (4.96 ± 0.20, %ID/g). The high tumor uptake of these probes in mice suggests their potential for application in imaging of EDB-FN-positive breast cancer for disease staging of regional and distant metastases.
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Neoplasias de la Mama , Fibronectinas , Colorantes Fluorescentes , Tomografía de Emisión de Positrones , Animales , Femenino , Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/patología , Neoplasias de la Mama/metabolismo , Humanos , Ratones , Tomografía de Emisión de Positrones/métodos , Línea Celular Tumoral , Colorantes Fluorescentes/química , Fibronectinas/metabolismo , Imagen Óptica/métodos , Neoplasias Pulmonares/diagnóstico por imagen , Neoplasias Pulmonares/patología , Neoplasias Pulmonares/metabolismo , Ratones Endogámicos BALB CRESUMEN
Parabens are widely used as preservatives in food, pharmaceuticals, and cosmetics due to their excellent antimicrobial activities, cost-effectiveness, and stability. Previous studies have demonstrated their harmful potential and ubiquity in the environment and human tissues. This study revealed profiles of parabens and their metabolites in urine samples from a general population of different ages in China using non-target screening. Metabolism of parabens in human bodies was further explored through the identified metabolites in combination of molecular networking. A total of 34 paraben compounds were screened in the urine samples. In addition to 3 identified confidence level 1 (CL1) parent parabens, 3 CL2 compounds were also identified, namely 4-hydroxybenzoic acid, 3,4-dihydroxybenzoic acid, and ethylparaben sulfate. Furthermore, 6 CL3 compounds were tentatively identified, five of which were sulfonated and sulfated metabolites of parabens. The remaining 22 were CL4 features without certain chemical structures. Hazardousness assessment suggested toxic potential of the identified metabolites. Distribution of the parabens and metabolites in the urines showed age-dependent differences. Sulfonation and sulfation were potentially significant metabolic pathways of the parabens in human bodies. This study provides a new insight into understanding metabolism of parabens in human bodies and potential risks of human exposure to parabens.
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The objective of this research was to examine the effectiveness of chitosan (CH)-gallic acid (GA) conjugate (CH-g-GA) as an edible coating in improving the physicochemical properties and oxidative stability of deep-fat fried pork meatballs. The meatballs were coated with either CH alone, a combination of CH and GA, or CH-g-GA before being fried at 180 °C for 5 min. The viscosity of the coating solutions influenced the amount of coating picked up by the meatballs, with higher viscosity coatings showing increased pickup. The application of chitosan-based coatings in deep-fried meatballs resulted in a decrease in moisture loss and oil uptake, as well as decreased b* values and hardness, while maintaining consistent cooking yield. Furthermore, compared to the control group, the chitosan-based coatings treatment significantly increased the ratio of immobilized water and decreased the ratio of free water (P < 0.05), as well as effectively inhibited lipid oxidation in deep-fried meatballs (P < 0.05). Among the different coatings tested, CH-g-GA coating exhibited the highest effectiveness. The research findings suggest that the CH-g-GA edible coating has significant potential in enhancing the overall quality of deep-fried meatballs.
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Quitosano , Culinaria , Ácido Gálico , Productos de la Carne , Oxidación-Reducción , Quitosano/química , Ácido Gálico/química , Animales , Productos de la Carne/análisis , Porcinos , Carne de Cerdo/análisis , Viscosidad , Agua/química , ColorRESUMEN
Electroreduction mediated by organo-mediators has emerged as a concise and effective strategy, holding significant potential in the site-specific introduction of deuterium. In this study, we present an environmentally friendly electroreduction approach for anti-Markovnikov selective deuteroarylation of alkenes and aryl iodides with D2O as the deuterium source. The key to the protocol lies in the employment of a catalytic amount of 2,2'-bipyiridine as an efficient organo-mediator, which facilitates the generation of aryl radicals by assisting in the cleavage of the C-X (X = I or Br) bonds in aryl halides. Because its reduction potential matches that of aryl iodides, the organo-mediator can control the chemoselectivity of the reaction and avoid the side reactions of competitive substrate deuteration. These phenomena are theoretically supported by CV experiments and DFT calculations. Our protocol provides a series of mono-deuterated alkylarenes with excellent deuterium incorporation through two single-electron reductions (SER), without requiring metal catalysts, external reductants, and sacrificial anodes.
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For sequencing-based spatial transcriptomics data, the gene-spot count matrix is highly sparse. This feature is similar to scRNA-seq. The goal of this paper is to identify whether there exist genes that are frequently under-detected in Visium compared to bulk RNA-seq, and the underlying potential mechanism of under-detection in Visium. We collected paired Visium and bulk RNA-seq data for 28 human samples and 19 mouse samples, which covered diverse tissue sources. We compared the two data types and observed that there indeed exists a collection of genes frequently under-detected in Visium compared to bulk RNA-seq. We performed a motif search to examine the last 350 bp of the frequently under-detected genes, and we observed that the poly (T) motif was significantly enriched in genes identified from both human and mouse data, which matches with our previous finding about frequently under-detected genes in scRNA-seq. We hypothesized that the poly (T) motif may be able to form a hairpin structure with the poly (A) tails of their mRNA transcripts, making it difficult for their mRNA transcripts to be captured during Visium library preparation.
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Perfilación de la Expresión Génica , Transcriptoma , Ratones , Humanos , Animales , Perfilación de la Expresión Génica/métodos , ARN Mensajero/genética , ARN Mensajero/metabolismo , Análisis de Secuencia de ARN/métodos , Análisis de Secuencia de ARN/estadística & datos numéricos , RNA-Seq/métodos , Biología Computacional/métodos , Motivos de NucleótidosRESUMEN
Numerous studies have highlighted the potential of Lactic acid bacteria (LAB) fermentation of whey proteins for alleviating allergies. Nonetheless, the impact of LAB-derived metabolites on whey proteins antigenicity during fermentation remains uncertain. Our objective was to elucidate the impact of small molecular metabolites on the antigenicity of α-lactalbumin (α-LA) and ß-lactoglobulin (ß-LG). Through metabolomic analysis, we picked 13 bioactive small molecule metabolites from Lactobacillus delbrueckii subsp. bulgaricus DLPU F-36 for coincubation with α-LA and ß-LG, respectively. The outcomes revealed that valine, arginine, benzoic acid, 2-keto butyric acid, and glutaric acid significantly diminished the sensitization potential of α-LA and ß-LG, respectively. Moreover, chromatographic analyses unveiled the varying influence of small molecular metabolites on the structure of α-LA and ß-LG, respectively. Notably, molecular docking underscored that the primary active sites of α-LA and ß-LG involved in protein binding to IgE antibodies aligned with the interaction sites of small molecular metabolites. In essence, LAB-produced metabolites wield a substantial influence on the antigenic properties of whey proteins.
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Lactobacillus delbrueckii , Simulación del Acoplamiento Molecular , Proteína de Suero de Leche , Lactobacillus delbrueckii/metabolismo , Lactobacillus delbrueckii/química , Lactobacillus delbrueckii/inmunología , Proteína de Suero de Leche/química , Proteína de Suero de Leche/metabolismo , Fermentación , Lactoglobulinas/química , Lactoglobulinas/inmunología , Lactoglobulinas/metabolismo , Lactalbúmina/química , Lactalbúmina/inmunología , Lactalbúmina/metabolismo , Animales , Bovinos , Antígenos/inmunología , Antígenos/químicaRESUMEN
Postbiotics have been proposed as clinically viable alternatives to probiotics, addressing limitations and safety concerns associated with probiotic use. However, direct comparisons between the functional differences and health benefits of probiotics and postbiotics remain scarce. This study compared directly the desensitization effect of probiotics and postbiotics derived from Lactiplantibacillus plantarum strain DPUL-F232 in the whey protein-induced allergic rat model. The results demonstrate that administering both live and heat killed F232 significantly alleviated allergy symptoms, reduced intestinal inflammation, and decreased serum antibody and histamine levels in rats. Both forms of F232 were effective in regulating the Th1/Th2 balance, promoting the secretion of the regulatory cytokine IL-10, inhibiting mast cell degranulation and restoring the integrity of the intestinal barrier through the upregulation of tight junction proteins. Considering the enhanced stability and reduced safety concerns of postbiotics compared to probiotics, alongside their ability to regulate allergic reactions, we suggest that postbiotics may serve as viable substitutes for probiotics in managing food allergies and potentially other diseases.
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Hipersensibilidad a los Alimentos , Probióticos , Proteína de Suero de Leche , Animales , Proteína de Suero de Leche/farmacología , Ratas , Probióticos/farmacología , Lactobacillus plantarum , Ratas Sprague-Dawley , Mucosa Intestinal/inmunología , Masculino , Femenino , Calor , HumanosRESUMEN
Cow milk allergy is one of the common food allergies. Our previous study showed that the allergenicity of fermented milk is lower than that of unfermented skimmed milk in vitro, and the antigenicity of ß-lactoglobulin and α-lactalbumin in fermented milk was decreased by 67.54% and 80.49%, respectively. To confirm its effects in vivo, allergic BALB/C mice model was used to further study the allergenicity of fermented milk. It was found that compared with the skim milk (SM) group, the intragastrically sensitization with fermented milk had no obvious allergic symptoms and the fingers were more stable: lower levels of IgE, IgG, and IgA in serum, lower levels of plasma histamine and mast cell protein-1, and immune balance of Th1/Th2 and Treg/Th17. At the same time, intragastrically sensitization with fermented milk increased the α diversity of intestinal microbiota and changed the microbiota abundance: the relative abundance of norank-f-Muribaculaceae and Staphylococcus significantly decreased, and the abundance of Lachnospiraceae NK4A136 group, Bacteroides, and Turicibacter increased. In addition, fermented milk can also increase the level of short-chain fatty acids in the intestines of mice. It turns out that fermented milk is much less allergenicity than SM. PRACTICAL APPLICATION: Fermentation provides a theoretical foundation for reducing the allergenicity of milk and dairy products, thereby facilitating the production of low-allergenic dairy products suitable for individuals with milk allergies.
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Fermentación , Microbioma Gastrointestinal , Inmunoglobulina E , Lactobacillales , Ratones Endogámicos BALB C , Hipersensibilidad a la Leche , Leche , Animales , Hipersensibilidad a la Leche/inmunología , Ratones , Inmunoglobulina E/inmunología , Inmunoglobulina E/sangre , Leche/inmunología , Femenino , Lactobacillales/inmunología , Bovinos , Productos Lácteos Cultivados/microbiología , Lactoglobulinas/inmunología , Inmunoglobulina A , Lactalbúmina/inmunología , Inmunoglobulina G/sangre , Ácidos Grasos Volátiles/metabolismo , Histamina/metabolismoRESUMEN
There are the differences in the location of some acupoints between textbooks Meridians and Acupoints and Acupuncture and Moxibustion. Both of the textbooks are in the category of the "14th Five-Year Plan". The differences in acupoint location have brought some confusion for students, full-time teachers and researchers in the field of traditional Chinese medicine. In the paper, based on GB/T 12346-2021ï¼ Nomenclature and Location of Meridian Points, published in2021, and in reference with GB/T 12346-2006ï¼ Nomenclature and Location of Acupuncture Points, published in 2006, the discrepancy in the acupoint location was systematically collated in the aspects of the expression style and layout, text expression and potential difference of location between these two textbooks, published by China Press of Traditional Chinese Medicine, People's Medical Publishing House and China Science Publishing. Based on the historical evolution and the academic controversy of acupoint positioning, the reasons of the differences in acupoint location were analyzed, the potential influences on the teaching, examination, competition and research of Chinese medicine acupuncture were explored, and the suggestions for solution were proposed.
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Puntos de Acupuntura , Terapia por Acupuntura , Meridianos , Moxibustión , Humanos , Moxibustión/historia , China , Acupuntura/educación , Acupuntura/historia , Medicina Tradicional ChinaRESUMEN
Immune checkpoint blockade (ICB) therapy has been approved for breast cancer (BC), but clinical response rates are limited. Recent studies have shown that commensal microbes colonize a variety of tumors and are closely related to the host immune system response. Here, we demonstrated that Fusobacterium nucleatum (F.n), which is prevalent in BC, creates an immunosuppressive tumor microenvironment (ITME) characterized by a high-influx of myeloid cells that hinders ICB therapy. Administering the antibiotic metronidazole in BC can deplete F.n and remodel the ITME. To prevent an imbalance in the systemic microbiota caused by antibiotic administration, we designed a biomimetic nanovehicle for on-site antibiotic delivery inspired by F.n homing to BC. Additionally, ferritin-nanocaged doxorubicin was coloaded into this nanovehicle, as immunogenic chemotherapy has shown potential for synergy with ICB. It has been demonstrated that this biomimetic nanovehicle can be precisely homed to BC and efficiently eliminate intratumoral F.n without disrupting the diversity and abundance of systemic microbiota. This ultimately remodels the ITME, improving the therapeutic efficacy of the PD-L1 blocker with a tumor inhibition rate of over 90% and significantly extending the median survival of 4T1 tumor-bearing mice.
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Fusobacterium nucleatum , Neoplasias , Animales , Ratones , Antígeno B7-H1 , Biomimética , Antibacterianos , Inmunosupresores , Microambiente TumoralRESUMEN
With alkyl halides (I, Br, Cl) as a coupling partner, an electrochemically driven strategy for para-selective C(sp2)-H alkylation of electron-deficient arenes (aryl esters, aldehydes, nitriles, and ketones) has been achieved to access diverse alkylated arenes in one step. The reaction enables the activation of alkyl halides in the absence of sacrificial anodes, achieving the formation of C(sp2)-C(sp3) bonds under mild electrolytic conditions. The utility of this protocol is reflected in high site selectivity, broad substrate scope, and scalable.
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BACKGROUND: Ultrasound guide technology, which can provide real-time visualization of the needle tip and tissues and avoid many adverse events, is widely used in minimally invasive therapy. However, the studies on ultrasound-guided Lateral recess block (LRB) are limited, this is probably because there is no recognized standard method for ultrasound scanning. This study aimed to evaluate the effect of ultrasound-guided LRB in patients with lateral recess stenosis (LRS). CASE SUMMARY: A 65-year-old patient complained of low back pain accompanied occasionally by pain and numbness in the left lower limb. Physical examination showed tenderness on the spinous process and paraspinal muscles from L1 to S1, extensor hallucis longus and tibialis anterior weakness (muscle strength: 4-), and a positive straight leg raising test in the left lower limb (60°). Magnetic resonance imaging showed L4-L5 disc degeneration with left LRS and nerve root entrapment. Subsequently, the patient was diagnosed with LRS. This patient was treated with a novel ultrasound-guided LRB approach. The patient's symptoms significantly improved without any complications at 1 wk postoperatively and at the 3-month follow-up. CONCLUSION: This is the first report on the LRS treatment with ultrasound-guided LRB from the contralateral spinous process along the inner side of the articular process by out-plane technique. Further studies are expected to investigate the efficacy and safety of ultrasound-guided LRB for patients with LRS.
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In vivo optical imaging of trace biomarkers in residual microtumors holds significant promise for cancer prognosis but poses a formidable challenge. Here, a novel hydrogel sensor is designed for ultrasensitive and specific imaging of the elusive biomarker. This hydrogel sensor seamlessly integrates a molecular beacon nanoprobe with fibroblasts, offering both high tissue retention capability and an impressive signal-to-noise ratio for imaging. Signal amplification is accomplished through exonuclease I-mediated biomarker recycling. The resulting hydrogel sensor sensitively detects the biomarker carcinoembryonic antigen with a detection limit of 1.8 pg mL-1 in test tubes. Moreover, it successfully identifies residual cancer nodules with a median diameter of less than 2 mm in mice bearing partially removed primary triple-negative breast carcinomas (4T1). Notably, this hydrogel sensor is proven effective for the sensitive diagnosis of invasive tumors in post-surgical mice with infiltrating 4T1 cells, leveraging the role of fibroblasts in locally enriching tumor cells. Furthermore, the residual microtumor is rapidly photothermal ablation by polydopamine-based nanoprobe under the guidance of visualization, achieving ≈100% suppression of tumor recurrence and lung metastasis. This work offers a promising alternative strategy for visually detecting residual microtumors, potentially enhancing the prognosis of cancer patients following surgical interventions.
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Hidrogeles , Neoplasias , Humanos , Ratones , AnimalesRESUMEN
Effect of fuel injection pressure on organic carbon (OC), elemental carbon (EC) and particulate semivolatile organic compounds (SVOCs), i.e., n-alkanes and polycyclic aromatic hydrocarbons (PAHs), emissions from a common-rail diesel engine was analyzed comprehensively. EC emission rate evidently decreased with increasing injection pressure at low fuel injection pressure ranges (80-120 MPa), while engine load effect on the EC emission was insignificant at high injection pressure ranges (140-160 MPa). The higher fraction of EC2 in the total EC emission appeared at the highest injection pressure ranges (140-160 MPa) under middle and high loads, suggesting the spontaneous carbonization process from soot precursor to ordered soot during the high temperature process. Low injection pressure provided poor combustion condition and caused unburned diesel fuel to volatilize more 2-3 ring PAHs. The percentage of 4-ring PAHs exhibited a rise-then-fall trend with increasing injection pressure, while the maximum percentage of 5-7 ring PAHs appeared at the highest injection pressure ranges (140-160 MPa) under high load condition, suggesting that higher combustion temperature and larger pyrolysis zone under the high injection pressure promoted the formation of lager and more stable PAHs. The fractions of fuel-derived short chain (C16-C21) and oil-derived long chain (C22-C33) in the total n-alkanes exhibited obvious load and injection pressure dependence.
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With cyanopyridines and alkyl bromides as coupling partners, an electrochemically driven C4-selective decyanoalkylation has been established to access diverse 4-alkylpyridines in one step. The reaction proceeds through the single electron reduction/radical-radical coupling tandem process under mild electrolytic conditions, achieving the cleavage of the C(sp2)-CN bond and the formation of C(sp3)-C(sp2). The practicality of this protocol is illustrated by no sacrificial anodes, a broad substrate scope, and gram-scale synthesis.