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Attentional control, guided by top-down processes, enables selective focus on pertinent information, while habituation, influenced by bottom-up factors and prior experiences, shapes cognitive responses by emphasizing stimulus relevance. These two fundamental processes collaborate to regulate cognitive behavior, with the prefrontal cortex and its subregions playing a pivotal role. Nevertheless, the intricate neural mechanisms underlying the interaction between attentional control and habituation are still a subject of ongoing exploration. To our knowledge, there is a dearth of comprehensive studies on the functional connectivity between subsystems within the prefrontal cortex during attentional control processes in both primates and humans. Utilizing stereo-electroencephalogram (SEEG) recordings during the Stroop task, we observed top-down dominance effects and corresponding connectivity patterns among the orbitofrontal cortex (OFC), the middle frontal gyrus (MFG), and the inferior frontal gyrus (IFG) during heightened attentional control. These findings highlighting the involvement of OFC in habituation through top-down attention. Our study unveils unique connectivity profiles, shedding light on the neural interplay between top-down and bottom-up attentional control processes, shaping goal-directed attention.
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Atenção , Eletroencefalografia , Habituação Psicofisiológica , Córtex Pré-Frontal , Humanos , Córtex Pré-Frontal/fisiologia , Córtex Pré-Frontal/diagnóstico por imagem , Atenção/fisiologia , Masculino , Feminino , Eletroencefalografia/métodos , Habituação Psicofisiológica/fisiologia , Adulto , Adulto Jovem , Teste de StroopRESUMO
In contrast to traditional static surfaces, smart patterned surfaces with periodical and reversible morphologies offer limitless opportunities for encoding surface functions and properties on demand, facilitating their widespread application as functional building blocks in various devices. Advances in intelligently controlling the macroscopic properties of these smart surfaces have been accomplished through various techniques (such as three-dimensional printing, imprint lithography and femtosecond laser) and responsive materials. In contrast to the sophisticated techniques above, dynamic anisotropic wrinkling, taking advantage of dynamic programmable manipulation of surface wrinkling and its orientation, offers a powerful alternative for fabricating dynamic periodical patterns due to its spontaneous formation, versatility, convenient scale-up fabrication, and sensitivity to various stimuli. This review comprehensively summarizes recent advances in smart patterned surfaces with dynamic oriented wrinkles, covering design principles, fabrication techniques, representative types of physical and chemical stimuli, as well as fine-tuning of wrinkle dimensions and orientation. Finally, advanced applications of these smart patterned surfaces are presented, along with a discussion of current challenges and future prospects in this rapidly evolving field. This review would offer some insights and guidelines for designing and engineering novel stimuli-responsive smart wrinkled surfaces, thereby facilitating their sustainable development and progressing toward commercialization.
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BACKGROUND AND AIMS: Absorptive root traits play important roles in acquisition of water and nutrients from soil by plants. Despite numerous reports on the changes in species dominance under long-term drought in grassland community, few studies have specifically investigated absorptive root traits of these dominant species in grasslands, especially in the alpine grasslands. METHODS: Here, two grass species (Leymus secalinus and Stipa purpurea) differing in their responses to drought were selected from an alpine steppe. A series of absorptive root traits were examined under drought in a 3-year glasshouse experiment. KEY RESULTS: We found that drought had no effects on root morphological and architectural traits, whereas root physiological traits and rooting depth differed in their responses to drought. Specifically, drought significantly reduced root respiration and enhanced organ carbon (C) exudation rate, carboxylate exudation rate, acid phosphatase activity and rooting depth of L. secalinus. Particularly, L. secalinus released more citrate into the rhizosphere under drought than S. purpurea. In contrast, these root traits of S. purpurea remained relatively unchanged in response to the drought. These differential responses would render L. secalinus more competitive in acquisition of nutrients and water, thus contributing to its dominance in the community under drought. Moreover, root respiration was negatively correlated with organic C exudation rate, carboxylate exudation rate and acid phosphatase activity, indicating a tradeoff between root respiration and root exudates to acquire nutrients and water by optimizing C allocation under drought. Additionally, all root traits exhibited two independent dimensions in root economic space (RES) for both species under drought. CONCLUSIONS: These results indicate that the plant species with great capacity to acquire water and nutrients in soil by optimizing C allocation under drought will be dominant in the community of the alpine grasslands. These findings provide an important insight into species re-ordering under drought on the Tibetan Plateau.
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A simple and rapid system based on Raman nanosphere (R-Sphere) immunochromatography was developed in this study for the simultaneous detection of Influenza A, B virus antigens on a single test line (T-line). Two types of R-Sphere with different characteristic Raman spectrum were used as the signal source, which were labeled with monoclonal antibodies against FluA, FluB (tracer antibodies), respectively. A mixture of antibodies containing anti-FluA monoclonal antibody and anti-FluB monoclonal antibody (capture antibody) was sprayed on a single T-line and goat anti-chicken IgY antibody was coated as a C-line, and the antigen solution with known concentration was detected by the strip of lateral flow immunochromatography based on surface-enhanced Raman spectroscopy (SERS). The T-line was scanned with a Raman spectrometer and SERS signals were collected. Simultaneous specific recognition and detection of FluA and FluB were achieved on a single T-line by analyzing the SERS signals. The findings indicated that the test system could identify FluA and FluB in a qualitative manner in just 15 minutes, with a minimum detection threshold of 0.25 ng ml-1, excellent consistency, and specificity. There was no interference with the other four respiratory pathogens, and it exhibited 8 times greater sensitivity compared to the colloidal gold test strip method. The assay system is rapid, sensitive, and does not require repetitive sample pretreatment steps and two viruses can be detected simultaneously on a single T-line by titrating one sample, which improves detection efficiency, and provide a reference for developing multiplexed detection techniques for other respiratory viruses.
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Antígenos Virais , Vírus da Influenza A , Vírus da Influenza B , Nanosferas , Análise Espectral Raman , Análise Espectral Raman/métodos , Vírus da Influenza A/isolamento & purificação , Vírus da Influenza A/imunologia , Antígenos Virais/análise , Antígenos Virais/imunologia , Nanosferas/química , Vírus da Influenza B/imunologia , Vírus da Influenza B/isolamento & purificação , Cromatografia de Afinidade/métodos , Cromatografia de Afinidade/instrumentação , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/química , Animais , HumanosRESUMO
Surgical resection remains the primary treatment modality for glioblastoma (GBM); however, the infiltrative nature of GBM margins complicates achieving complete tumor removal. Additionally, the blood-brain barrier (BBB) poses a formidable challenge to effective probe delivery, thereby hindering precise imaging-guided surgery. Here, we introduce hybrid cell membrane-coated indocyanine green (ICG) liposomes (HM-Lipo-ICG) as biomimetic near-infrared (NIR) fluorescent probes for targeted BBB penetration and accurate delineation of infiltrative GBM margins. HM-Lipo-ICG encapsulates clinically approved ICG within its core and utilizes a hybrid cell membrane exterior, enabling specific targeting and enhanced BBB permeation. Quantitative assessments demonstrate that HM-Lipo-ICG achieves BBB penetration efficiency 2.8 times higher than conventional ICG liposomes. Mechanistically, CD44 receptor-mediated endocytosis facilitates BBB translocation of HM-Lipo-ICG. Furthermore, HM-Lipo-ICG enables high-contrast NIR imaging, achieving a signal-to-background ratio of 6.5 in GBM regions of an orthotopic glioma mouse model, thereby improving tumor margin detection accuracy fourfold (84.4% vs. 22.7%) compared to conventional ICG liposomes. Application of HM-Lipo-ICG facilitates fluorescence-guided precision surgery, resulting in complete resection of GBM cells. This study underscores the potential of hybrid cell membrane-coated liposomal probes in precisely visualizing and treating infiltrative GBM margins.
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Barreira Hematoencefálica , Neoplasias Encefálicas , Membrana Celular , Glioblastoma , Verde de Indocianina , Lipossomos , Verde de Indocianina/química , Lipossomos/química , Barreira Hematoencefálica/metabolismo , Glioblastoma/diagnóstico por imagem , Glioblastoma/patologia , Animais , Camundongos , Humanos , Neoplasias Encefálicas/diagnóstico por imagem , Linhagem Celular Tumoral , Membrana Celular/metabolismo , Corantes Fluorescentes/química , Camundongos Nus , Imagem Óptica/métodosRESUMO
The CRISPR-Cas12a system has emerged as a powerful tool for next-generation nucleic acid-based molecular diagnostics. However, it has long been believed to be effective only on DNA targets. Here, we investigate the intrinsic RNA-enabled trans-cleavage activity of AsCas12a and LbCas12a and discover that they can be directly activated by full-size RNA targets, although LbCas12a exhibits weaker trans-cleavage activity than AsCas12a on both single-stranded DNA and RNA substrates. Remarkably, we find that the RNA-activated Cas12a possesses higher specificity in recognizing mutated target sequences compared to DNA activation. Based on these findings, we develop the "Universal Nuclease for Identification of Virus Empowered by RNA-Sensing" (UNIVERSE) assay for nucleic acid testing. We incorporate a T7 transcription step into this assay, thereby eliminating the requirement for a protospacer adjacent motif (PAM) sequence in the target. Additionally, we successfully detect multiple PAM-less targets in HIV clinical samples that are undetectable by the conventional Cas12a assay based on double-stranded DNA activation, demonstrating unrestricted target selection with the UNIVERSE assay. We further validate the clinical utility of the UNIVERSE assay by testing both HIV RNA and HPV 16 DNA in clinical samples. We envision that the intrinsic RNA targeting capability may bring a paradigm shift in Cas12a-based nucleic acid detection and further enhance the understanding of CRISPR-Cas biochemistry.
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Proteínas Associadas a CRISPR , Sistemas CRISPR-Cas , RNA , Humanos , Proteínas Associadas a CRISPR/metabolismo , Proteínas Associadas a CRISPR/genética , Sistemas CRISPR-Cas/genética , Desoxirribonucleases/metabolismo , Endodesoxirribonucleases/metabolismo , Endodesoxirribonucleases/genética , Endodesoxirribonucleases/química , RNA/metabolismo , RNA/química , RNA/genéticaRESUMO
Proton batteries are promising candidates for next-generation large-scale energy storage in extreme conditions due to the small ionic radius and efficient transport of protons. Hydrogen gas, with its low working potentials, fast kinetics, and stability, further enhances the performance of proton batteries but necessitates the development of novel electrolytes with low freezing points and reduced corrosion. This work introduces a localized water restriction strategy by incorporating a tertiary component with a high donor number, which forms strong bonds with water molecules. This approach restricts free water molecules and reduces the average hydrogen bond ratio and strength. As-prepared ternary eutectic electrolytes lowered the freezing point to -103 °C, significantly lower than the traditional binary electrolyte (9.5 m H3PO4, -93 °C). This electrolyte is highly compatible with the Cu0.79Co0.21[Fe(CN)6]0.64·4H2O (CoCuHCF) cathode, reducing material dissolution and current collector corrosion. The H2||CoCuHCF battery using this electrolyte demonstrated a high-power density of 23664.3 W kg-1, excellent performance at -80 °C, and stable cyclability over 1000 cycles (> 30 days) at -50 °C. These findings provide a framework for proton electrolytes, highlighting the potential of hydrogen batteries in challenging environments.
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microRNA-1827 (miR-1827) is proposed to be enriched in exosomes from mesenchymal stem cells (MSCs-Exos). A recent study has addressed the suppressive effect of exosomes from human umbilical cord mesenchymal stem cells (hUC-MSCs-Exos) on colorectal cancer (CRC) metastasis. Hence, our study aims at investigating whether hUC-MSCs-Exos can modulate the liver metastasis in CRC by mediating miR-1827. Transmission electron microscopy (TEM) and nanoparticle tracking analysis (NTA) were used to identify hUC-MSCs-Exos. Using gain- and loss-of-function approaches, the expression of miR-1827 and succinate receptor 1 (SUCNR1) was altered. Consequently, the biological functions of CRC cells were assessed by CCK-8 and Transwell assays and macrophage M2 polarization was assayed by flow cytometry. Dual-luciferase reporter assay was applied to clarify interaction between miR-1827 and SUCNR1. CRC cells were incubated with hUC-MSCs-Exos and tumor-bearing mice were injected with hUC-MSCs-Exos to examine the effects on CRC cell growth and metastasis. SUCNR1, lowly expressed in CRC, could promote CRC cell growth and macrophage M2 polarization. miR-1827 could target SUCNR1 and hence suppress the progression and metastasis of CRC. hUC-MSCs-Exos carried miR-1827 to inhibit M2 macrophage polarization by downregulating SUCNR1 expression, and inhibited proliferating, migrating and invading properties of CRC cells. Furthermore, hUC-MSCs-Exos carrying miR-1827 blocked CRC liver metastasis in vivo. These findings indicate hUC-MSCs-Exos as an inhibitor of M2 macrophage polarization and liver metastasis in CRC through inducing miR-1827-targeted inhibition of SUCNR1. This provides a theoretical basis for understanding the mechanisms underlying Exos-based target therapy for CRC.
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Neoplasias Colorretais , Exossomos , Neoplasias Hepáticas , Células-Tronco Mesenquimais , MicroRNAs , Animais , Humanos , Camundongos , Apoptose , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Exossomos/genética , Exossomos/metabolismo , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Macrófagos/metabolismo , Células-Tronco Mesenquimais/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Cordão UmbilicalRESUMO
We developed a single-tube one-step gel-based reverse transcription-recombinase polymerase amplification (RT-RPA)/polymerase chain reaction (PCR) (termed "SOG RT-RPA/PCR") to detect the human immunodeficiency virus (HIV). To improve the assay sensitivity, the RNA template is pre-amplified by RT-RPA prior to PCR. To simplify the detection process and shorten the assay time, we embedded PCR reagents into agarose gel, constructing it to physically separate the reagents from the RT-RPA reaction solution in a single tube. Due to the thermodynamic properties of agarose, the RT-RPA reaction first occurs independently on top of the PCR gel at a low temperature (e.g., 39 °C) during the SOG RT-RPA/PCR assay. Then, the RPA amplicons directly serve as the template for the second PCR amplification reaction, which begins when the PCR agarose dissolves due to the elevated reaction temperature, eliminating the need for multiple manual operations and amplicon transfer. With our SOG RT-RPA/PCR assay, we could detect 6.3 copies of HIV RNA per test, which is a 10-fold higher sensitivity than that of standalone real-time RT-PCR and RT-RPA. In addition, due to the high amplification efficiency of RPA, the SOG RT-RPA/PCR assay shows stronger fluorescence detection signals and a shorter detection time compared to the standalone real-time RT-PCR assay. Furthermore, we detected HIV viral RNA in clinical plasma samples and validated the superior performance of our assay. Thus, the SOG RT-RPA/PCR assay offers a powerful method for simple, rapid, and highly sensitive nucleic acid-based molecular detection of infectious diseases.
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Infecções por HIV , Técnicas de Amplificação de Ácido Nucleico , Humanos , Técnicas de Amplificação de Ácido Nucleico/métodos , HIV/genética , Sefarose , Reação em Cadeia da Polimerase em Tempo Real/métodos , RNA Viral/genética , Transcrição Reversa , Recombinases/genética , Infecções por HIV/diagnóstico , Sensibilidade e EspecificidadeRESUMO
BACKGROUND: The current study probed into how tumor cell-derived exosomes (Exos) mediated hsa_circ_0001739/lncRNA AC159540.1 to manipulate microRNA (miR)-218-5p/FTO-N6-methyladenosine (m6A)/MYC signal axis in liver metastasis in colorectal cancer (CRC). METHODS: hsa_circ_0001739 and lncRNA AC159540.1 were identified as the upstream regulator of miR-218-5p using ENCORI and LncBase databases. Expression patterns of miR-218-5p, hsa_circ_0001739, lncRNA AC159540.1, FTO, and MYC were detected, accompanied by loss-and-gain-of function assays to examine their effects on CRC cell biological functions. SW480 cells-derived Exos were purified, followed by in vitro studies to uncover the effect of hsa_circ_0001739/lncRNA AC159540. RESULTS: miR-218-5p was downregulated while hsa_circ_0001739/lncRNA AC159540.1 was upregulated in CRC tissues and cells. Silencing of hsa_circ_0001739/lncRNA AC159540.1 restrained the malignant phenotypes of CRC cells. Exos-mediated hsa_circ_0001739/lncRNA AC159540.1 competitively inhibited miR-218-5p to elevate FTO and MYC. The inducing role of Exos-mediated hsa_circ_0001739/lncRNA AC159540.1 in CRC was also validated in vivo. CONCLUSION: Conclusively, Exos-mediated circ_0001739/lncRNA AC159540.1 regulatory network is critical for CRC, offering a theoretical basis for CRC treatment.
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Neoplasias Colorretais , Exossomos , Neoplasias Hepáticas , MicroRNAs , RNA Longo não Codificante , Humanos , RNA Longo não Codificante/genética , Exossomos/genética , Neoplasias Hepáticas/genética , MicroRNAs/genética , Neoplasias Colorretais/genética , Proliferação de Células/genética , Dioxigenase FTO Dependente de alfa-CetoglutaratoRESUMO
Organic peroxides (POs) are ubiquitous in the atmosphere and particularly reactive toward dissolved sulfur dioxide (SO2), yet the reaction kinetics between POs and SO2, especially in complex inorganic-organic mixed particles, remain poorly constrained. Here, we report the first investigation of the multiphase reactions between SO2 and POs in monoterpene-derived secondary organic aerosol internally mixed with different inorganic salts (ammonium sulfate, ammonium bisulfate, or sodium nitrate). We find that when the particles are phase-separated, the PO-S(IV) reactivity is consistent with that measured in pure SOA and depends markedly on the water content in the organic shell. However, when the organic and inorganic phases are miscible, the PO-S(IV) reactivity varies substantially among different aerosol systems, mainly driven by their distinct acidities (not by ionic strength). The second-order PO-S(IV) rate constant decreases monotonically from 5 × 105 to 75 M-1 s-1 in the pH range of 0.1-5.6. Both proton catalysis and general acid catalysis contribute to S(IV) oxidation, with their corresponding third-order rate constants determined to be (6.4 ± 0.7) × 106 and (6.9 ± 4.6) × 104 M-2 s-1 at pH 2-6, respectively. The measured kinetics imply that the PO-S(IV) reaction in aerosol is an important sulfate formation pathway, with the reaction kinetics dominated by general acid catalysis at pH > 3 under typical continental atmospheric conditions.
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Peróxidos , Dióxido de Enxofre , Sulfatos/química , Atmosfera/química , AerossóisRESUMO
Alpha-fetoprotein (AFP) is an important protein biomarker of liver cancer, as its serum levels are highly correlated with the progression of disease. Conventional immunoassays for AFP detection rely on enzyme-linked immunosorbent assay analyses with expensive and bulky equipment. Here, we developed a simple, affordable, and portable CRISPR-powered personal glucose meter biosensing platform for quantitative detection of the AFP biomarker in serum samples. The biosensor takes advantage of the excellent affinity of aptamer to AFP and the collateral cleavage activity of CRISPR-Cas12a, enabling sensitive and specific CRISPR-powered protein biomarker detection. To enable point-of-care testing, we coupled invertase-catalyzed glucose production with the glucose biosensing technology to quantify AFP. Using the developed biosensing platform, we quantitatively detected AFP biomarker in spiked human serum samples with a detection sensitivity of down to 10 ng/mL. Further, we successfully applied the biosensor to detect AFP in clinical serum samples from patients with liver cancer, achieving comparable performance to the conventional assay. Therefore, this novel CRISPR-powered personal glucose meter biosensor provides a simple yet powerful alternative for detecting AFP and potentially other tumor biomarkers at the point of care.
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This paper describes the study of the acoustic field of a fluid-filled pipe subjected to axial stress based on the acoustoelastic theory. The pipe with applied axial stresses can be approximated as a transversely isotropic pipe, and hence, its acoustic fields can be expressed using potential functions. The velocity changes of longitudinal wave modes with applied stresses are analyzed for the pipe filled with oil by an analytical method. It was found that the longitudinal mode velocity changes almost uniformly with the applied stresses. The high speed and low frequency plateaus of longitudinal wave modes are sensitive to stress. The relationship between stress and the velocity change of the guided wave is given. The results indicate that non-destructive testing techniques using longitudinal wave modes have strong potential to identify and monitor the stress levels in pipe structures.
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PURPOSE: To investigate whether novices could improve performance on a shoulder arthroscopic simulator (high-fidelity) through short-term training on a Fundamentals of Arthroscopic Surgery Training (FAST) simulator (low-fidelity). METHODS: Twenty-eight novices with no experience in arthroscopy were recruited to perform a pre-test on a shoulder arthroscopic simulator. Then they were randomized into two groups: the experimental group practiced five modules on the FAST simulator three times, and the control group did nothing. The experimental group performed a post-test immediately after FAST simulator practice. Control group rested for 70 minutes after experiencing pre-test before performing post-test. All parameters were recorded by the simulator. RESULTS: The experimental group outperformed the control group in terms of total score, procedure time, camera path length, and grasper path length. However, there was no statistical difference in scratching of humerus cartilage or glenoid cartilage. Significant differences were found in the improvement of both groups in total score, procedure time, and camera path length. CONCLUSIONS: Arthroscopic skills gained after short-term training on FAST simulator could be transferred to the shoulder arthroscopic simulator. This research provides important evidence of the benefits of FAST simulator in shoulder arthroscopy training program.
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Artroscopia , Internato e Residência , Treinamento por Simulação , Artroscopia/educação , Competência Clínica , Simulação por Computador , Treinamento por Simulação/métodos , Articulação do Ombro/cirurgia , Distribuição Aleatória , HumanosRESUMO
In this paper, a novel S-scheme CuS/Bi5O7I heterojunction was successfully constructed using a two-step approach comprising the alkaline hydrothermal method and the adsorption-deposition method, and it consisted of Bi5O7I microrods with CuS particles covering the surface. The photocatalytic antibacterial effects on Escherichia coli (E. coli) were systematically examined with visible light exposure. The results suggested that the 3%-CuS/Bi5O7I composite showed the optimal antibacterial activity, completely inactivating E. coli (5 × 108 cfu/mL) in 180 min of irradiation. Moreover, the bacterial inactivation process was scientifically described. â¢O2- and h+ were the major active species for the inactivation of the bacteria. In the early stages, SOD and CAT initiated the protection system to avoid the oxidative destruction of the active species. Unfortunately, the antioxidant protection system was overwhelmed thereafter, which led to the destruction of the cell membrane, as evidenced by the microstructure changes in E. coli cells. Subsequently, the leakage of intracellular components including K+, proteins, and DNA resulted in the unavoidable death of E. coli. Due to the construction of the S-scheme heterojunction, the CuS/Bi5O7I composite displayed the boosted visible light harvesting, the high-efficiency separation of photogenerated electrons and holes, and a great redox capacity, contributing to an outstanding photocatalytic disinfection performance. This work offers a new opportunity for S-scheme Bi5O7I-based heterojunctions with potential application in water disinfection.
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Desinfecção , Escherichia coli , Escherichia coli/efeitos da radiação , Desinfecção/métodos , Catálise , Luz , AntibacterianosRESUMO
PURPOSE: This paper aimed to assess the diagnostic utility of a newly developed gene-based technology-nanopore targeted sequencing (NTS) in suspected endophthalmitis patients. METHODS: This retrospective study included 43 patients (44 eyes) with suspected endophthalmitis. NTS was applied along with microbiological culture to detect unknown pathogens in intraocular fluid samples. The diagnostic utility of NTS was mainly evaluated from three aspects, including the positivity rate of bacterial/fungal presence, diagnostic turnaround time and the frequency of change in treatment based on etiology test results. Non-parametric, two-sided Wilcoxon rank sum test, the McNemar's test and the kappa statistic were used for statistical comparisons. RESULTS: NTS showed significant advantages over traditional culture in positivity rates and diagnostic time (P < 0.001, kappa = 0.082; Z = -5.805, P < 0. 001). As regards antibiotic strategy, 17 patients (39.53%) and 5 patients (11.63%) underwent medication change following NTS and culture results respectively (P < 0.001, kappa = 0.335). With reasonable use of antibiotic and surgical intervention, most patients responded favorably, judged by significantly improved visual acuity (Z = -4.249, P < 0.001). The mean duration of hospitalization was 8.49 ± 2.45 days (range, 1-16 days). CONCLUSION: The high efficiency feature of NTS in pathogen detection renders it a valuable supplementary to traditional culture. Additionally, it has facilitated patients' management for the early and precise diagnosis of endophthalmitis.
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Endoftalmite , Infecções Oculares Bacterianas , Nanoporos , Humanos , Estudos Retrospectivos , Endoftalmite/etiologia , Humor Aquoso/microbiologia , Antibacterianos/uso terapêutico , Infecções Oculares Bacterianas/microbiologiaRESUMO
High molecular weight dimeric compounds constitute a significant fraction of secondary organic aerosol (SOA) and have profound impacts on the properties and lifecycle of particles in the atmosphere. Although different formation mechanisms involving reactive intermediates and/or closed-shell monomeric species have been proposed for the particle-phase dimers, their relative importance remains in debate. Here, we report unambiguous experimental evidence of the important role of acyl organic peroxy radicals (RO2) and a small but non-negligible contribution from stabilized Criegee intermediates (SCIs) in the formation of particle-phase dimers during ozonolysis of α-pinene, one of the most important precursors for biogenic SOA. Specifically, we find that acyl RO2-involved reactions explain 50-80% of total oxygenated dimer signals (C15-C20, O/C ≥ 0.4) and 20-30% of the total less oxygenated (O/C < 0.4) dimer signals. In particular, they contribute to 70% of C15-C19 dimer ester formation, likely mainly via the decarboxylation of diacyl peroxides arising from acyl RO2 cross-reactions. In comparison, SCIs play a minor role in the formation of C15-C19 dimer esters but react noticeably with the most abundant C9 and C10 carboxylic acids and/or carbonyl products to form C19 and C20 dimeric peroxides, which are prone to particle-phase transformation to form more stable dimers without the peroxide functionality. This work provides a clearer view of the formation pathways of particle-phase dimers from α-pinene oxidation and would help reduce the uncertainties in future atmospheric modeling of the budget, properties, and health and climate impacts of SOA.
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Poluentes Atmosféricos , Ozônio , Aerossóis , Monoterpenos Bicíclicos , Ácidos Carboxílicos , Ésteres , Monoterpenos , PeróxidosRESUMO
Organic peroxides play a vital role in the formation, evolution, and health impacts of atmospheric aerosols, yet their molecular composition and fate in the particle phase remain poorly understood. Here, we identified, using iodometry-assisted liquid chromatography mass spectrometry, a large suite of isomer-resolved peroxide monomers (C8-10H12-18O5-8) and dimers (C15-20H22-34O5-14) in secondary organic aerosol formed from ozonolysis of the most abundant monoterpene (α-pinene). Combining aerosol isothermal evaporation experiments and multilayer kinetic modeling, bulk peroxides were found to undergo rapid particle-phase chemical transformation with an average lifetime of several hours under humid conditions, while the individual peroxides decompose on timescales of half an hour to a few days. Meanwhile, the majority of isomeric peroxides exhibit distinct particle-phase behaviors, highlighting the importance of the characterization of isomer-resolved peroxide reactivity. Furthermore, the reactivity of most peroxides increases with aerosol water content faster in a low relative humidity (RH) range than in a high RH range. Such non-uniform water effects imply a more important role of water as a plasticizer than as a reactant in influencing the peroxide reactivity. The high particle-phase reactivity of organic peroxides and its striking dependence on RH should be considered in atmospheric modeling of their fate and impacts on aerosol chemistry and health effects.
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Monoterpenos , Ozônio , Aerossóis/química , Monoterpenos/química , Ozônio/química , Peróxidos/química , ÁguaRESUMO
Multiplexed detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) rather than detection targeting a single gene is crucial to ensure more accurate coronavirus disease 2019 (COVID-19) diagnostics. Here, we develop a monolithic, 3D-printed, lab-on-disc platform for multiplexed molecular detection of SARS-CoV-2. The centrifugal lab-on-disc is fabricated in one step using simple 3D printing technology, circumventing the need for aligning and binding multiple layers. By combining isothermal amplification technology, this lab-on-disc platform is capable of simultaneously detecting the nucleoprotein and envelope genes of SARS-CoV-2 as well as an internal control of the human POP7 gene. Within a 50-minute incubation period, 100 copies SARS-CoV-2 RNA can be detected through visual observation according to color and fluorescence changes in the disc. Further, we clinically validated the lab-on-disc platform by testing 20 nasopharyngeal swab samples and demonstrated a sensitivity of 100% and an accuracy of 95%. Therefore, the monolithic, 3D-printed, lab-on-disc platform provides simple, rapid, disposable, sensitive, reliable, and multiplexed molecular detection of SARS-CoV-2, holding promise for COVID-19 diagnostics at the point of care.
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Gastric cancer (GC) is one of the most common devastating and deadly malignancies of the gastrointestinal tract in the world. GLOBOCAN data analysis showed that GC accounted for approximately 1,033,000 new cases of cancer and 78,200 deaths in 2018. Nonstructural maintenance of chromosomes (non-SMC) condensin I complex subunit H (NCAPH) is a regulatory subunit that encodes the non-SMC condensin I complex. Previous studies have demonstrated that NCAPH is highly expressed in multiple cancers. This study aimed to explore the function and potential mechanism of NCAPH in GC. Our study showed that NCAPH expression was significantly upregulated in The Cancer Genome Atlas (TCGA) and Oncomine datasets. Quantitative real-time polymerase chain reaction and western blotting were used to detect NCAPH expression in GC and paracarcinoma tissues. Cell Counting Kit-8 (CCK-8) and colony formation assays were used to examine cell proliferation. Cell scratch and Transwell invasion assays were performed to assess cell migration. In addition, western blotting was used to detect the expression of proteins related to the cell cycle, DNA damage repair, and epithelial-mesenchymal transition (EMT). Flow cytometry was applied for cell cycle and apoptosis detection. A xenograft model was employed to assess the effect of NCAPH in vivo. The results demonstrated that NCAPH expression was significantly increased in GC tissue samples and cell lines. Knockout of NCAPH notably inhibited cell proliferation, cell migration, cell invasion, cell cycle progression, and tumor growth in vitro and in vivo, and induced the G1-phase cell cycle arrest by regulating the DNA damage response. In addition, knockout of NCAPH promoted cell apoptosis and regulated the expression of EMT-related proteins. The results indicate that the knockout of NCAPH in GC cells inhibits proliferation and metastasis via the DNA damage response in vitro and in vivo. NCAPH plays an important role in GC and may be a potential therapeutic target for GC treatment.