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1.
Proc Natl Acad Sci U S A ; 119(14): e2104496119, 2022 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-35344428

RESUMO

SignificancePhysical and chemical properties of individual atmospheric particles determine their climate impacts. Hygroscopic inorganic salt particles mixed with trace amounts of organic material are predicted to be liquid under typical tropospheric conditions in the summertime Arctic. Yet, we unexpectedly observed a significant concentration of solid particles composed of ammonium sulfate with an organic coating under conditions of high relative humidity and low temperature. These particle properties are consistent with marine biogenic-derived new particle formation and growth, with particle collision hypothesized to result in the solid phase. This particle source is predicted to have increasing relevance in the context of declining Arctic sea ice and increasing open water, with impacts on clouds, and therefore climate.

2.
Stem Cells ; 41(12): 1171-1184, 2023 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-37659098

RESUMO

Acute-on-chronic liver failure (ACLF) is a severe disease with a high mortality. Macrophage-related inflammation plays a crucial role in ACLF development. Mesenchymal stem cells (MSCs) treatment was demonstrated to be beneficial in ACLF in our previous study; however, the underlying mechanisms remain unknown. Therefore, mouse bone marrow-derived MSCs were used to treat an ACLF mouse model or cocultured with RAW264.7/J774A.1 macrophages that were stimulated with LPS. Histological and serological parameters and survival were analyzed to evaluate efficacy. We detected changes of Mer tyrosine kinase (Mertk), JAK1/STAT6, inflammatory cytokines, and markers of macrophage polarization in vitro and in vivo. In ACLF mice, MSCs improved liver function and 48-h survival of ACLF mice and alleviated inflammatory injury by promoting M2 macrophage polarization and elevated Mertk expression levels in macrophages. This is significant, as Mertk regulates M2 macrophage polarization via the JAK1/STAT6 signaling pathway.


Assuntos
Insuficiência Hepática Crônica Agudizada , Células-Tronco Mesenquimais , Camundongos , Animais , Insuficiência Hepática Crônica Agudizada/metabolismo , Proteínas Tirosina Quinases/metabolismo , Macrófagos/metabolismo , Transdução de Sinais , Células-Tronco Mesenquimais/metabolismo , c-Mer Tirosina Quinase/genética , c-Mer Tirosina Quinase/metabolismo
3.
Environ Sci Technol ; 58(24): 10675-10684, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38843196

RESUMO

Isoprene has the highest atmospheric emissions of any nonmethane hydrocarbon, and isoprene epoxydiols (IEPOX) are well-established oxidation products and the primary contributors forming isoprene-derived secondary organic aerosol (SOA). Highly acidic particles (pH 0-3) widespread across the lower troposphere enable acid-driven multiphase chemistry of IEPOX, such as epoxide ring-opening reactions forming methyltetrol sulfates through nucleophilic attack of sulfate (SO42-). Herein, we systematically demonstrate an unexpected decrease in SOA formation from IEPOX on highly acidic particles (pH < 1). While IEPOX-SOA formation is commonly assumed to increase at low pH when more [H+] is available to protonate epoxides, we observe maximum SOA formation at pH 1 and less SOA formation at pH 0.0 and 0.4. This is attributed to limited availability of SO42- at pH values below the acid dissociation constant (pKa) of SO42- and bisulfate (HSO4-). The nucleophilicity of HSO4- is 100× lower than SO42-, decreasing SOA formation and shifting particulate products from low-volatility organosulfates to higher-volatility polyols. Current model parameterizations predicting SOA yields for IEPOX-SOA do not properly account for the SO42-/HSO4- equilibrium, leading to overpredictions of SOA formation at low pH. Accounting for this underexplored acidity-dependent behavior is critical for accurately predicting SOA concentrations and resolving SOA impacts on air quality.


Assuntos
Aerossóis , Compostos de Epóxi/química , Concentração de Íons de Hidrogênio , Equilíbrio Ácido-Base
4.
J Nanobiotechnology ; 22(1): 355, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38902678

RESUMO

BACKGROUND: Cancer recurrence following surgical resection is a major cause of treatment failure. Finding effective methods to prevent postoperative recurrence and wound infection is an important component of successful surgery. With the development of new nanotechnology, more treatment options have been provided for postoperative adjuvant therapy. This study presents an innovative hydrogel system that stimulates tumoricidal immunity after surgical resection of non-small cell lung cancer (NSCLC) and prevents cancer relapse. RESULTS: The hydrogel system is based on the excellent photothermal conversion performance of single-atom platinum (CN-Pt) along with the delivery and release of the chemotherapy drug, gemcitabine (GEM). The system is coated onto the wound surface after tumor removal with subsequent near-infrared (NIR) photothermal therapy, which efficiently induces necroptosis of residual cancer cells, amplifies the levels of damage-associated molecular patterns (DAMPs), and increases the number of M1 macrophages. The significantly higher levels of phagocytic macrophages enhance tumor immunogenicity and sensitize cancer cells to CD8 + T-cell immunity to control postoperative recurrence, which has been verified using an animal model of postoperative lung cancer recurrence. The CN-Pt-GEM-hydrogel with NIR can also inhibit postoperative wound infection. CONCLUSIONS: These findings introduce an alternative strategy for supplementing antitumor immunity in patients undergoing resection of NSCLC tumors. The CN-Pt-GEM-hydrogel with the NIR system also exhibits good biosafety and may be adaptable for clinical application in relation to tumor resection surgery, wound tissue filling, infection prevention, and recurrence prevention.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Desoxicitidina , Gencitabina , Hidrogéis , Neoplasias Pulmonares , Necroptose , Animais , Camundongos , Desoxicitidina/análogos & derivados , Desoxicitidina/farmacologia , Desoxicitidina/uso terapêutico , Hidrogéis/química , Humanos , Necroptose/efeitos dos fármacos , Recidiva Local de Neoplasia , Linhagem Celular Tumoral , Imunoterapia/métodos , Terapia Fototérmica/métodos , Infecção dos Ferimentos/prevenção & controle , Infecção dos Ferimentos/tratamento farmacológico , Macrófagos/efeitos dos fármacos , Camundongos Endogâmicos C57BL , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/efeitos dos fármacos
5.
Genomics ; 115(6): 110737, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37926353

RESUMO

BACKGROUND: Acute-on-chronic liver failure (ACLF) is a major challenge in the field of hepatology. While mesenchymal stem cell (MSC) therapy can improve the prognosis of patients with ACLF, the molecular mechanisms through which MSCs attenuate ACLF remain poorly understood. We performed global miRNA and mRNA expression profiling via next-generation sequencing of liver tissues from MSC-treated ACLF mice to identify important signaling pathways and major factors implicated in ACLF alleviation by MSCs. METHODS: Carbon tetrachloride-induced ACLF mice were treated with saline or mouse bone marrow-derived MSCs. Mouse livers were subjected to miRNA and mRNA sequencing. Related signal transduction pathways were obtained through Gene Set Enrichment Analysis. Functional enrichment, protein-protein interaction, and immune infiltration analyses were performed for the differentially expressed miRNA target genes (DETs). Hub miRNA and mRNA associated with liver injury were analyzed using LASSO regression. The expression levels of hub genes were subjected to Pearson's correlation analysis and verified using RT-qPCR. The biological functions of hub genes were verified in vitro. RESULTS: The tricarboxylic acid cycle and peroxisome proliferator-activated receptor pathways were activated in the MSC-treated groups. The proportions of liver-infiltrating NK resting cells, M2 macrophages, follicular helper T cells, and other immune cells were altered after MSC treatment. The expression levels of six miRNAs and 10 transcripts correlated with the degree of liver injury. miR-27a-5p was downregulated in the mouse liver after MSC treatment, while its target gene E2f2 was upregulated. miR-27a-5p inhibited E2F2 expression, suppressed G1/S phase transition and proliferation of hepatocytes, in addition to promoting their apoptosis. CONCLUSIONS: This is the first comprehensive analysis of miRNA and mRNA expression in the liver tissue of ACLF mice after MSC treatment. The results revealed global changes in hepatic pathways and immune subpopulations. The miR-27a-5p/E2F2 axis emerged as a central regulator of the MSC-induced attenuation of ACLF. The current findings improve our understanding of the molecular mechanisms through which MSCs alleviate ACLF.


Assuntos
Insuficiência Hepática Crônica Agudizada , Células-Tronco Mesenquimais , MicroRNAs , Humanos , Camundongos , Animais , MicroRNAs/genética , MicroRNAs/metabolismo , Insuficiência Hepática Crônica Agudizada/genética , Insuficiência Hepática Crônica Agudizada/terapia , Insuficiência Hepática Crônica Agudizada/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Células-Tronco Mesenquimais/metabolismo
6.
Anal Chem ; 94(35): 11973-11977, 2022 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-35993793

RESUMO

The phase (solid, semisolid, or liquid) of atmospheric aerosols is central to their ability to take up water or undergo heterogeneous reactions. In recent years, the unexpected prevalence of viscous organic particles has been shown through field measurements and global atmospheric modeling. The aerosol phase has been predicted using glass transition temperatures (Tg), which were estimated based on molecular weight, oxygen:carbon ratio, and chemical formulae of organic species present in atmospheric particles via studies of bulk materials. However, at the most important sizes for cloud nucleation (∼50-500 nm), particles are complex mixtures of numerous organic species, inorganic salts, and water with substantial particle-to-particle variability. To date, direct measurements of Tg have not been feasible for individual atmospheric particles. Herein, nanothermal analysis (NanoTA), which uses a resistively heated atomic force microscopy (AFM) probe, is combined with AFM photothermal infrared (AFM-PTIR) spectroscopy to determine the Tg and composition of individual particles down to 76 nm in diameter at ambient temperature and pressure. Laboratory-generated proxies for organic aerosol (sucrose, ouabain, raffinose, and maltoheptaose) had similar Tg values to bulk Tg values measured with differential scanning calorimetry (DSC) and the Tg predictions used in atmospheric models. Laboratory-generated phase-separated particles and ambient particles were analyzed with NanoTA + AFM-PTIR showing intraparticle variation in composition and Tg. These results demonstrate the potential for NanoTA + AFM-PTIR to increase our understanding of viscosity within submicrometer atmospheric particles with complex phases, morphologies, and compositions, which will enable improved modeling of aerosol impacts on clouds and climate.


Assuntos
Água , Aerossóis/química , Microscopia de Força Atômica/métodos , Tamanho da Partícula , Temperatura , Temperatura de Transição
7.
BMC Infect Dis ; 22(1): 369, 2022 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-35413851

RESUMO

BACKGROUND: Streptococcus suis is an emerging zoonotic pathogen that mainly causes meningitis, sepsis, arthritis, endocarditis, and endophthalmitis in human. To the best of our knowledge, Spinal canal infection caused by Streptococcus suis has rarely been reported. CASE PRESENTATION: Here we report a case of spinal canal infection caused by Streptococcus suis in a 50-year-old male patient. The patient had a history of close contact with sick pigs days before disease onset. Initially he presented with headache and fever. After admission, the patient began to experience lower back pain, which led physicians to perform a lumber puncture. Meta-genomic next generation sequencing helped identify Streptococcus suis in the cerebrospinal fluid. MRI imaging indicated a spinal canal infection caused by Streptococcus suis. CONCLUSIONS: Spinal canal infection is an uncommon disease of Streptococcus suis infection. This case report indicates that people presented with fever, headache and lower back pain should also be suspected as Streptococcus suis infection, especially for those who have had a history of sick pig contact.


Assuntos
Dor Lombar , Meningites Bacterianas , Infecções Estreptocócicas , Streptococcus suis , Cefaleia , Humanos , Masculino , Meningites Bacterianas/diagnóstico , Canal Medular , Infecções Estreptocócicas/líquido cefalorraquidiano , Infecções Estreptocócicas/diagnóstico , Streptococcus suis/genética
8.
Environ Sci Technol ; 56(15): 10596-10607, 2022 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-35834796

RESUMO

Aerosol acidity increases secondary organic aerosol (SOA) formed from the reactive uptake of isoprene-derived epoxydiols (IEPOX) by enhancing condensed-phase reactions within sulfate-containing submicron particles, leading to low-volatility organic products. However, the link between the initial aerosol acidity and the resulting physicochemical properties of IEPOX-derived SOA remains uncertain. Herein, we show distinct differences in the morphology, phase state, and chemical composition of individual organic-inorganic mixed particles after IEPOX uptake to ammonium sulfate particles with different initial atmospherically relevant acidities (pH = 1, 3, and 5). Physicochemical properties were characterized via atomic force microscopy coupled with photothermal infrared spectroscopy (AFM-PTIR) and Raman microspectroscopy. Compared to less acidic particles (pH 3 and 5), reactive uptake of IEPOX to the most acidic particles (pH 1) resulted in 50% more organosulfate formation, clearer phase separation (core-shell), and more irregularly shaped morphologies, suggesting that the organic phase transitioned to semisolid or solid. This study highlights that initial aerosol acidity may govern the subsequent aerosol physicochemical properties, such as viscosity and morphology, following the multiphase chemical reactions of IEPOX. These results can be used in future studies to improve model parameterizations of SOA formation from IEPOX and its properties, toward the goal of bridging predictions and atmospheric observations.


Assuntos
Atmosfera , Hemiterpenos , Ácidos/química , Aerossóis/química , Atmosfera/química , Butadienos , Concentração de Íons de Hidrogênio
9.
J Phys Chem A ; 126(35): 5974-5984, 2022 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-36017944

RESUMO

Organosulfates formed from heterogeneous reactions of organic-derived oxidation products with sulfate ions can account for >15% of secondary organic aerosol (SOA) mass, primarily in submicron particles with long atmospheric lifetimes. However, fundamental understanding of organosulfate molecular structures is limited, particularly at atmospherically relevant acidities (pH = 0-6). Herein, for 2-methyltetrol sulfates (2-MTSs), an important group of isoprene-derived organosulfates, protonation state and vibrational modes were studied using Raman and infrared spectroscopy, as well as density functional theory (DFT) calculations of vibrational spectra for neutral (RO-SO3H) and anionic/deprotonated (RO-SO3-) structures. The calculated sulfate group vibrations differ for the two protonation states due to their different sulfur-oxygen bond orders (1 or 2 versus 12/3 for the neutral and deprotonated forms, respectively). Only vibrations at 1060 and 1041 cm-1, which are associated with symmetric S-O stretches of the 2-MTS anion, were observed experimentally with Raman, while sulfate group vibrations for the neutral form (∼900, 1200, and 1400 cm-1) were not observed. Additional calculations of organosulfates formed from other SOA-precursor gases (α-pinene, ß-caryophyllene, and toluene) identified similar symmetric vibrations between 1000 and 1100 cm-1 for RO-SO3-, consistent with corresponding organosulfates formed during laboratory experiments. These results suggest that organosulfates are primarily deprotonated at atmospheric pH values, which have further implications for aerosol acidity, heterogeneous reactions, and continuing chemistry in atmospheric aerosols.


Assuntos
Sulfatos , Enxofre , Aerossóis/química , Teoria da Densidade Funcional , Oxirredução , Sulfatos/química
10.
Mol Carcinog ; 60(12): 826-839, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34499769

RESUMO

Gastric cancer (GC) has one of the highest tumor incidences worldwide. Heat shock protein 70 (HSP70) is highly expressed and plays a critical role in the occurrence, progression, metastasis, poor prognosis, and drug resistance of GC. However, the underlying mechanisms of HSP70 are not clear. To explore the regulatory role of HSP70 in GC, we performed cell counting kit-8 (CCK-8) and EdU staining assays to assess cell proliferation; immunohistochemistry and western blot analyses to assess protein expression; coimmunoprecipitation (Co-IP) assays to assess interactions between two proteins; and immunofluorescence to assess protein expression and localization. HSP70 was highly expressed in clinical samples from patients with GC and indicated a poor prognosis. HSP70 inhibition enhanced the sensitivity of GC cells to thermochemotherapy. Furthermore, we found that S phase kinase-associated protein 2 (Skp2) was highly expressed in GC and correlated with HSP70 in array data from The Cancer Genome Atlas (TCGA). Importantly, HSP70 inhibition promoted Skp2 degradation. Skp2 overexpression abrogated HSP70 inhibition-induced cell cycle arrest, suggesting that the role of HSP70 in GC depends on Skp2 expression. Our results illustrate a possible regulatory mechanism of HSP70 and may provide a therapeutic strategy for overcoming resistance to thermochemotherapy.


Assuntos
Proteínas de Choque Térmico HSP70/metabolismo , Proteínas Quinases Associadas a Fase S/química , Proteínas Quinases Associadas a Fase S/metabolismo , Neoplasias Gástricas/metabolismo , Regulação para Cima , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Progressão da Doença , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Masculino , Oxaliplatina/farmacologia , Prognóstico , Estabilidade Proteica , Nucleosídeos de Purina/farmacologia , Regulação para Cima/efeitos dos fármacos
11.
BMC Infect Dis ; 21(1): 587, 2021 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-34144700

RESUMO

BACKGROUND: Talaromyces marneffei (T. marneffei) infection has been associated with adult-onset immunodeficiency due to anti-IFN-γ autoantibodies. We aimed to investigate the clinical features of non-HIV-infected patients with T. marneffei infection in southern China. METHODS: Between January 2018 and September 2020, we enrolled patients with T. marneffei infection who were HIV-negative (group TM, n = 42), including anti-IFN-γ autoantibody-positive (group TMP, n = 22) and anti-IFN-γ autoantibody-negative (group TMN, n = 20) patients and healthy controls (group HC, n = 40). Anti-IFN-γ autoantibodies were detected by ELISA. Clinical characteristics and clinical laboratory parameters were recorded. RESULTS: Compared with anti-IFN-γ autoantibody-negative patients with T. marneffei infection, anti-IFN-γ autoantibody-positive patients did not have underlying respiratory disease; more frequently exhibited dissemination of systemic infections with severe pleural effusion; had higher WBC counts, C-reactive protein levels, erythrocyte sedimentation rates, and neutrophil and CD8+ T cell counts; had lower hemoglobin levels; and were more likely to have other intracellular pathogen infections. Most of these patients had poor outcomes despite standardized antimicrobial therapy. CONCLUSION: T. marneffei-infected patients with higher anti-IFN-γ autoantibody titers have more severe disease and complex clinical conditions.


Assuntos
Síndromes de Imunodeficiência/etiologia , Interferon gama/imunologia , Micoses/imunologia , Adulto , Autoanticorpos/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Índice de Gravidade de Doença
12.
Cancer Sci ; 111(5): 1567-1581, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32133742

RESUMO

The histone demethylase lysine-specific demethylase 4A (KDM4A) is reported to be overexpressed and plays a vital in multiple cancers through controlling gene expression by epigenetic regulation of H3K9 or H3K36 methylation marks. However, the biological role and mechanism of KDM4A in prostate cancer (PC) remain unclear. Herein, we reported KDM4A expression was upregulation in phosphatase and tensin homolog knockout mouse prostate tissue. Depletion of KDM4A in PC cells inhibited their proliferation and survival in vivo and vitro. Further studies reveal that USP1 is a deubiquitinase that regulates KDM4A K48-linked deubiquitin and stability. Interestingly, we found c-Myc was a key downstream effector of the USP1-KDM4A/androgen receptor axis in driving PC cell proliferation. Notably, upregulation of KDM4A expression with high USP1 expression was observed in most prostate tumors and inhibition of USP1 promotes PC cells response to therapeutic agent enzalutamide. Our studies propose USP1 could be an anticancer therapeutic target in PC.


Assuntos
Antineoplásicos/uso terapêutico , Inibidores Enzimáticos/uso terapêutico , Histona Desmetilases com o Domínio Jumonji/metabolismo , Neoplasias da Próstata/tratamento farmacológico , Proteases Específicas de Ubiquitina/antagonistas & inibidores , Animais , Antineoplásicos/farmacologia , Benzamidas , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular , Inibidores Enzimáticos/farmacologia , Expressão Gênica , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células HEK293 , Humanos , Histona Desmetilases com o Domínio Jumonji/genética , Masculino , Camundongos , Camundongos Mutantes , Nitrilas , PTEN Fosfo-Hidrolase/deficiência , Feniltioidantoína/análogos & derivados , Feniltioidantoína/farmacologia , Feniltioidantoína/uso terapêutico , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Ligação Proteica/efeitos dos fármacos , Estabilidade Proteica/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-myc/genética , Receptores Androgênicos/genética , Receptores Androgênicos/metabolismo , Transdução de Sinais/efeitos dos fármacos , Proteases Específicas de Ubiquitina/genética , Proteases Específicas de Ubiquitina/metabolismo , Ubiquitinação/efeitos dos fármacos
13.
Anal Chem ; 92(14): 9932-9939, 2020 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-32519841

RESUMO

Physicochemical analysis of individual atmospheric aerosols at the most abundant sizes in the atmosphere (<1 µm) is analytically challenging, as hundreds to thousands of species are often present in femtoliter volumes. Vibrational spectroscopies, such as infrared (IR) and Raman, have great potential for probing functional groups in single particles at ambient pressure and temperature. However, the diffraction limit of IR radiation limits traditional IR microscopy to particles > ∼10 µm, which have less relevance to aerosol health and climate impacts. Optical photothermal infrared (O-PTIR) spectroscopy is a contactless method that circumvents diffraction limitations by using changes in the scattering intensity of a continuous wave visible laser (532 nm) to detect the photothermal expansion when a vibrational mode is excited by a tunable IR laser (QCL: 800-1800 cm-1 or OPO: 2600-3600 cm-1). Herein, we simultaneously collect O-PTIR spectra with Raman spectra at a single point for individual particles with aerodynamic diameters <400 nm (prior to impaction and spreading) at ambient temperature and pressure, by also collecting the inelastically scattered visible photons for Raman spectra. O-PTIR and Raman spectra were collected for submicrometer particles with different substrates, particle chemical compositions, and morphologies (i.e., core-shell), as well as IR mapping with submicron spatial resolution. Initial O-PTIR analysis of ambient atmospheric particles identified both inorganic and organic modes in individual sub- and supermicrometer particles. The simultaneous IR and Raman microscopy with submicrometer spatial resolution described herein has considerable potential both in atmospheric chemistry and numerous others fields (e.g., materials and biological research).

14.
Anal Chem ; 92(9): 6502-6511, 2020 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-32227877

RESUMO

The acidity of atmospheric aerosols is a critical property that affects the chemistry and composition of the atmosphere. Many key multiphase chemical reactions are pH-dependent, impacting processes like secondary organic aerosol formation, and need to be understood at a single particle level due to differences in particle-to-particle composition that impact both climate and health. However, the analytical challenge of measuring aerosol acidity in individual particles has limited pH measurements for fine (<2.5 µm) and coarse (2.5-10 µm) particles. This has led to a reliance on indirect methods or thermodynamic modeling, which focus on average, not individual, particle pH. Thus, new approaches are needed to probe single particle pH. In this study, a novel method for pH measurement was explored using degradation of a pH-sensitive polymer, poly(ε-caprolactone), to determine the acidity of individual submicron particles. Submicron particles of known pH (0 or 6) were deposited on a polymer film (21-25 nm thick) and allowed to react. Particles were then rinsed off, and the degradation of the polymer was characterized using atomic force microscopy and Raman microspectroscopy. After degradation, holes in the PCL films exposed to pH 0 were observed, and the loss of the carbonyl stretch was monitored at 1723 cm-1. As particle size decreased, polymer degradation increased, indicating an increase in aerosol acidity at smaller particle diameters. This study describes a new approach to determine individual particle acidity and is a step toward addressing a key measurement gap related to our understanding of atmospheric aerosol impacts on climate and health.


Assuntos
Poluentes Atmosféricos/análise , Polímeros/química , Aerossóis/análise , Atmosfera/química , Concentração de Íons de Hidrogênio , Estrutura Molecular , Tamanho da Partícula , Propriedades de Superfície
15.
J Med Virol ; 92(9): 1676-1680, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32330305

RESUMO

PURPOSE: The purpose of this study was to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ribonucleic acid (RNA) in urine and blood specimens, and anal and oropharyngeal swabs from patients with confirmed SARS-CoV-2 infection, and correlated positive results with clinical findings. METHODS: Patients with confirmed SARS-CoV-2 infections were included in this study. Patients' demographic and clinical data were recorded. Quantitative real-time polymerase chain reaction was used to detect SARS-CoV-2 RNA in urine and blood specimens, and anal and oropharyngeal swabs. The study is registered at ClinicalTrials.gov (No. NCT04279782, 19 February, 2020). RESULTS: SARS-CoV-2 RNA was present in all four specimen types, though not all specimen types were positive simultaneously. The presence of viral RNA was not necessarily predictive of clinical symptoms, for example, the presence of viral RNA in the urine did not necessarily predict urinary tract symptoms. CONCLUSIONS: SARS-CoV-2 can infect multiple systems, including the urinary tract. Testing different specimen types may be useful for monitoring disease changes and progression, and for establishing a prognosis.


Assuntos
Canal Anal/virologia , Líquidos Corporais/virologia , COVID-19/diagnóstico , COVID-19/virologia , Orofaringe/virologia , SARS-CoV-2 , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , RNA Viral/genética , Reação em Cadeia da Polimerase em Tempo Real , SARS-CoV-2/classificação , SARS-CoV-2/genética , SARS-CoV-2/isolamento & purificação
16.
Chin J Cancer Res ; 32(6): 794-803, 2020 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-33447001

RESUMO

OBJECTIVE: Systemic chemotherapy has limited efficacy in the treatment of peritoneal metastasis (PM) in gastric cancer (GC). Hyperthermic intraperitoneal chemotherapy (HIPEC) combined with complete cytoreductive surgery (CRS) has shown promising outcomes but remains controversial. The present study aimed to evaluate the safety and efficacy of HIPEC without CRS in GC patients with PM. METHODS: This retrospective propensity score-matched multicenter cohort study included GC patients with PM treated with either chemotherapy alone (Cx group) or with HIPEC combined with chemotherapy (HIPEC-Cx group) in four Chinese high-volume gastric medical centers between 2010 and 2017. The primary outcomes were median survival time (MST) and 3-year overall survival (OS). Propensity score matching was performed to compensate for controlling potential confounding effects and selection bias. RESULTS: Of 663 eligible patients, 498 were matched. The MST in the Cx and HIPEC-Cx groups was 10.8 and 15.9 months, respectively [hazard ratio (HR)=0.71, 95% confidence interval (95% CI), 0.58-0.88; P=0.002]. The 3-year OS rate was 10.1% (95% CI, 5.4%-14.8%) and 18.4% (95% CI, 12.3%-24.5%) in the Cx and HIPEC-Cx groups, respectively (P=0.017). The complication rates were comparable. The time to first flatus and length of hospital stay for patients undergoing HIPEC combined with chemotherapy was longer than that of chemotherapy alone (4.6±2.4 dvs. 2.7±1.8 d, P<0.001; 14.2±5.8 dvs. 11.4±7.7 d, P<0.001), respectively. The median follow-up period was 33.2 months. CONCLUSIONS: Compared with standard systemic chemotherapy, HIPEC combined with chemotherapy revealed a statistically significant survival benefit for GC patients with PM, without compromising patient safety.

17.
Environ Sci Technol ; 53(9): 4977-4987, 2019 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-31002496

RESUMO

Aerosol phase state is critical for quantifying aerosol effects on climate and air quality. However, significant challenges remain in our ability to predict and quantify phase state during its evolution in the atmosphere. Herein, we demonstrate that aerosol phase (liquid, semisolid, solid) exhibits a diel cycle in a mixed forest environment, oscillating between a viscous, semisolid phase state at night and liquid phase state with phase separation during the day. The viscous nighttime particles existed despite higher relative humidity and were independently confirmed by bounce factor measurements and atomic force microscopy. High-resolution mass spectrometry shows the more viscous phase state at night is impacted by the formation of terpene-derived and higher molecular weight secondary organic aerosol (SOA) and smaller inorganic sulfate mass fractions. Larger daytime particulate sulfate mass fractions, as well as a predominance of lower molecular weight isoprene-derived SOA, lead to the liquid state of the daytime particles and phase separation after greater uptake of liquid water, despite the lower daytime relative humidity. The observed diel cycle of aerosol phase should provoke rethinking of the SOA atmospheric lifecycle, as it suggests diurnal variability in gas-particle partitioning and mixing time scales, which influence aerosol multiphase chemistry, lifetime, and climate impacts.


Assuntos
Atmosfera , Sulfatos , Aerossóis , Química Orgânica , Florestas
18.
Environ Sci Technol ; 53(15): 8682-8694, 2019 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-31335134

RESUMO

Acid-driven multiphase chemistry of isoprene epoxydiols (IEPOX), key isoprene oxidation products, with inorganic sulfate aerosol yields substantial amounts of secondary organic aerosol (SOA) through the formation of organosulfur compounds. The extent and implications of inorganic-to-organic sulfate conversion, however, are unknown. In this article, we demonstrate that extensive consumption of inorganic sulfate occurs, which increases with the IEPOX-to-inorganic sulfate concentration ratio (IEPOX/Sulfinorg), as determined by laboratory measurements. Characterization of the total sulfur aerosol observed at Look Rock, Tennessee, from 2007 to 2016 shows that organosulfur mass fractions will likely continue to increase with ongoing declines in anthropogenic Sulfinorg, consistent with our laboratory findings. We further demonstrate that organosulfur compounds greatly modify critical aerosol properties, such as acidity, morphology, viscosity, and phase state. These new mechanistic insights demonstrate that changes in SO2 emissions, especially in isoprene-dominated environments, will significantly alter biogenic SOA physicochemical properties. Consequently, IEPOX/Sulfinorg will play an important role in understanding the historical climate and determining future impacts of biogenic SOA on the global climate and air quality.


Assuntos
Atmosfera , Pentanos , Aerossóis , Butadienos , Hemiterpenos , Sulfatos , Tennessee
19.
Mol Cancer ; 17(1): 126, 2018 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-30134915

RESUMO

BACKGROUND: Gastric cancer (GC) is a common malignancy and frequent cause of cancer-related death. Long non-coding RNAs (lncRNAs) have emerged as important regulators and tissue-specific biomarkers of multiple cancers, including GC. Recent evidence has indicated that the novel lncRNA LINC01133 plays an important role in cancer progression and metastasis. However, its function and molecular mechanism in GC remain largely unknown. METHODS: LINC01133 expression was detected in 200 GC and matched non-cancerous tissues by quantitative reverse transcription PCR. Gain- and loss-of-function experiments were conducted to investigate the biological functions of LINC01133 both in vitro and in vivo. Insights into the underlying mechanisms of competitive endogenous RNAs (ceRNAs) were determined by bioinformatics analysis, dual-luciferase reporter assays, quantitative PCR arrays, TOPFlash/FOPFlash reporter assay, luciferase assay, and rescue experiments. RESULTS: LINC01133 was downregulated in GC tissues and cell lines, and its low expression positively correlated with GC progression and metastasis. Functionally, LINC01133 depletion promoted cell proliferation, migration, and the epithelial-mesenchymal transition (EMT) in GC cells, whereas LINC01133 overexpression resulted in the opposite effects both in vitro and in vivo. Bioinformatics analysis and luciferase assays revealed that miR-106a-3p was a direct target of LINC01133, which functioned as a ceRNA in regulating GC metastasis. Mechanistic analysis demonstrated that miR-106a-3p specifically targeted the adenomatous polyposis coli (APC) gene, and LINC01133/miR-106a-3p suppressed the EMT and metastasis by inactivating the Wnt/ß-catenin pathway in an APC-dependent manner. CONCLUSIONS: Our findings suggest that reduced expression of LINC01133 is associated with aggressive tumor phenotypes and poor patient outcomes in GC. LINC01133 inhibits GC progression and metastasis by acting as a ceRNA for miR-106a-3p to regulate APC expression and the Wnt/ß-catenin pathway, suggesting that LINC01133 may serve as a potential prognostic biomarker and anti-metastatic therapeutic target for GC.


Assuntos
Proteína da Polipose Adenomatosa do Colo/genética , MicroRNAs/genética , RNA Longo não Codificante/genética , Neoplasias Gástricas/patologia , Via de Sinalização Wnt , Proteína da Polipose Adenomatosa do Colo/metabolismo , Animais , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Progressão da Doença , Regulação para Baixo , Transição Epitelial-Mesenquimal , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Camundongos , Metástase Neoplásica , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo
20.
Anal Chem ; 90(19): 11232-11239, 2018 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-30203960

RESUMO

Measuring the acidity of atmospheric aerosols is critical, as many key multiphase chemical reactions involving aerosols are highly pH-dependent. These reactions impact processes, such as secondary organic aerosol (SOA) formation, that impact climate and health. However, determining the pH of atmospheric particles, which have minute volumes (10-23-10-18 L), is an analytical challenge due to the nonconservative nature of the hydronium ion, particularly as most chemical aerosol measurements are made offline or under vacuum, where water can be lost and acid-base equilibria shifted. Because of these challenges, there have been no direct methods to probe atmospheric aerosol acidity, and pH has typically been determined by proxy/indirect methods, such as ion balance, or thermodynamic models. Herein, we present a novel and facile method for direct measurement of size-resolved aerosol acidity from pH 0 to 4.5 using quantitative colorimetric image processing of cellular phone images of (NH4)2SO4-H2SO4 aqueous aerosol particles impacted onto pH-indicator paper. A trend of increasing aerosol acidity with decreasing particle size was observed that is consistent with spectroscopic measurements of individual particle pH. These results indicate the potential for direct measurements of size-resolved atmospheric aerosol acidity, which is needed to improve fundamental understanding of pH-dependent atmospheric processes, such as SOA formation.

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