Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 40
Filtrar
Más filtros

Banco de datos
Tipo del documento
Intervalo de año de publicación
1.
Rev Med Virol ; 34(2): e2531, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38502012

RESUMEN

As an indispensable trace element, iron is essential for many biological processes. Increasing evidence has shown that virus infection can perturb iron metabolism and play a role in the occurrence and development of viral infection-related diseases. Ferritin plays a crucial role in maintaining the body's iron homoeostasis. It is an important protein to stabilise the iron balance in cells. Ferritin is a 24-mer hollow iron storage protein composed of two subunits: ferritin heavy chain and ferritin light chain. It was reported that ferritin is not only an intra-cellular iron storage protein, but also a pathogenic mediator that enhances the inflammatory process and stimulates the further inflammatory pathway, which is a key member of the vicious pathogenic cycle to perpetuate. Ferritin exerts immuno-suppressive and pro-inflammatory functions during viral infection. In this review, we describe in detail the basic information of ferritin in the first section, including its structural features, the regulation of ferritin. In the second part, we focus on the role of ferritin in viral infection-related diseases and the molecular mechanisms by which viral infection regulates ferritin. The last section briefly outlines the potential of ferritin in antiviral therapy. Given the importance of iron and viral infection, understanding the role of ferritin during viral infection helps us understand the relationship between iron metabolic dysfunction and viral infection, which provides a new direction for the development of antiviral therapeutic drugs.


Asunto(s)
Oligoelementos , Virosis , Humanos , Ferritinas , Hierro , Antivirales
2.
BMC Cancer ; 24(1): 170, 2024 Feb 03.
Artículo en Inglés | MEDLINE | ID: mdl-38310283

RESUMEN

BACKGROUND: The prognosis of SCLC is poor and difficult to predict. The aim of this study was to explore whether a model based on radiomics and clinical features could predict the prognosis of patients with limited-stage small cell lung cancer (LS-SCLC). METHODS: Simulated positioning CT images and clinical features were retrospectively collected from 200 patients with histological diagnosis of LS-SCLC admitted between 2013 and 2021, which were randomly divided into the training (n = 140) and testing (n = 60) groups. Radiomics features were extracted from simulated positioning CT images, and the t-test and the least absolute shrinkage and selection operator (LASSO) were used to screen radiomics features. We then constructed radiomic score (RadScore) based on the filtered radiomics features. Clinical factors were analyzed using the Kaplan-Meier method. The Cox proportional hazards model was used for further analyses of possible prognostic features and clinical factors to build three models including a radiomic model, a clinical model, and a combined model including clinical factors and RadScore. When a model has prognostic predictive value (AUC > 0.7) in both train and test groups, a nomogram will be created. The performance of three models was evaluated using area under the receiver operating characteristic curve (AUC) and Kaplan-Meier analysis. RESULTS: A total of 1037 features were extracted from simulated positioning CT images which were contrast enhanced CT of the chest. The combined model showed the best prediction, with very poor AUC for the radiomic model and the clinical model. The combined model of OS included 4 clinical features and RadScore, with AUCs of 0.71 and 0.70 in the training and test groups. The combined model of PFS included 4 clinical features and RadScore, with AUCs of 0.72 and 0.71 in the training and test groups. T stages, ProGRP and smoke status were the independent variables for OS in the combined model, whereas T stages, ProGRP and prophylactic cranial irradiation (PCI) were the independent factors for PFS. There was a statistically significant difference between the low- and high-risk groups in the combined model of OS (training group, p < 0.0001; testing group, p = 0.0269) and PFS (training group, p < 0.0001; testing group, p < 0.0001). CONCLUSION: Combined models involved RadScore and clinical factors can predict prognosis in LS-SCLC and show better performance than individual radiomics and clinical models.


Asunto(s)
Neoplasias Pulmonares , Carcinoma Pulmonar de Células Pequeñas , Humanos , Neoplasias Pulmonares/diagnóstico por imagen , Pronóstico , Radiómica , Estudios Retrospectivos , Carcinoma Pulmonar de Células Pequeñas/diagnóstico por imagen , Carcinoma Pulmonar de Células Pequeñas/terapia , Tomografía Computarizada por Rayos X
3.
Cell Mol Biol (Noisy-le-grand) ; 70(1): 148-154, 2024 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-38372101

RESUMEN

Left-sided colorectal cancer (LSCC) and right-sided colorectal cancer (RSCC) belong to colorectal cancer happening at different positions, which exhibit different pathogenesis. MicroRNA (miRNA)s are widely known regulators in diverse carcinomas. This research aims to identify a differentially expressed miRNA that simultaneously regulates genes associated with LSCC and RSCC and reveal their regulatory relation in cell migration and invasion. Bioinformatics analyses were conducted to uncover the dysregulated functional genes in LSCC/RSCC and obtain their common targeted miRNAs. The expression pattern of miR-27a-3p, TCF7L2, and TGFBR2 in cancerous and adjacent tissues from LSCC/RSCC patients was assessed through qRT-PCR, followed by Pearson's correlation coefficients analysis. The interaction of miR-27a-3p with TCF7L2 or TGFBR2 was thereafter confirmed through luciferase reporter assay. TCF7L2 and TGFBR2 protein levels were assessed by western blotting after overexpressing level of miR-27a-3p. Cell migration and invasion were routinely examined by wound healing and transwell experiments, respectively. TCF7L2 and TGFBR2 were respectively identified and verified to be lowly expressed in LSCC and RSCC, both of them were predicted and confirmed as targets of miR-27a-3p. MiR-27a-3p elevation exacerbated migration and invasion of both LSCC and RSCC cells. The impacts of miR-27a-3p on migration and invasion could be blocked by overexpressing TCF7L2 in LSCC cells and also reversed by up-regulating TGFBR2 in RSCC cells. In general, miR-27a-3p accelerated the migration and invasion capabilities of LSCC and RSCC cells through negatively regulating TCF7L2 and TGFBR2, respectively, which might be an effective molecular target for the treatment of LSCC/RSCC.


Asunto(s)
Neoplasias Colorrectales , MicroARNs , Receptor Tipo II de Factor de Crecimiento Transformador beta , Proteína 2 Similar al Factor de Transcripción 7 , Humanos , Movimiento Celular/genética , Proliferación Celular/genética , Neoplasias Colorrectales/genética , MicroARNs/genética , MicroARNs/metabolismo , Receptor Tipo II de Factor de Crecimiento Transformador beta/genética , Proteína 2 Similar al Factor de Transcripción 7/genética
4.
Int J Mol Sci ; 25(2)2024 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-38256017

RESUMEN

Red swamp crayfish, Procambarus clarkii (P. clarkii), is an important model crustacean organism used in many types of research. However, the effects of different doses of aminomethylphosphonic acid (AMAP) on the transcriptome and metabolites of P. clarkii have not been explored. Thus, this study investigated the molecular and metabolic mechanisms activated at the different exposure dosages of AMAP in P. clarkii to provide new insights into the strategies of P. clarkii in response to the high concentrations of AMAP in the environment. In the present study, the P. clarkii were divided into three groups (control group; low-dosage AMAP exposure; high-dosage AMAP exposure), and hepatopancreatic tissue samples were dependently taken from the three groups. The response mechanisms at the different dosages of AMAP were investigated based on the transcriptome and metabolome data of P. clarkii. Differentially expressed genes and differentially abundant metabolites were identified in the distinct AMAP dosage exposure groups. The genes related to ribosome cell components were significantly up-regulated, suggesting that ribosomes play an essential role in responding to AMAP stress. The metabolite taurine, involved in the taurine and hypotaurine metabolism pathway, was significantly down-regulated. P. clarkii may provide feedback to counteract different dosages of AMAP via the upregulation of ribosome-related genes and multiple metabolic pathways. These key genes and metabolites play an important role in the response to AMAP stress to better prepare for survival in high AMAP concentrations.


Asunto(s)
Astacoidea , Organofosfonatos , Transcriptoma , Animales , Astacoidea/genética , Metaboloma , Taurina
5.
Molecules ; 28(6)2023 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-36985798

RESUMEN

Kakadu plum (Terminalia ferdinandiana), endemic to Australia, is growing in popularity due to its high levels of vitamin C and strong antioxidant properties. In this study, Kakadu plum fruit powder was used as a functional food ingredient with other plant materials to develop value-added products to enhance their nutritional and commercial value. The present study determined the bioactive properties of nine products, including three Kakadu plum fruit powder samples produced from different processing batches and five Kakadu plum-blended products. Vitamin C, the total phenolic content, and the ellagic acid content were determined. Bioactive properties such as antioxidant, antidiabetic, and antimicrobial assays were also performed. Cytotoxicity was tested to obtain more specific product information regarding food safety. Kakadu plum-blended products showed lower cytotoxicity and lower bioactive properties (antioxidant and antibacterial activities) in comparison to Kakadu plum powder. However, overall, most of the bioactive properties were shown to be higher in the blends when compared with the commercial blueberry powder as a benchmark antioxidant product. Therefore, there is great potential for Kakadu plum to contribute to the growing functional food and ingredient markets.


Asunto(s)
Antioxidantes , Prunus domestica , Antioxidantes/farmacología , Polvos , Ácido Ascórbico , Fenoles/farmacología , Fenoles/análisis , Vitaminas , Frutas/química
6.
Opt Express ; 30(19): 35041-35049, 2022 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-36242505

RESUMEN

Transition from a gain-guided soliton (GGS) to a fully developed noise-like pulse (NLP) is numerically demonstrated in fiber lasers operated in the normal dispersion regime, which explains well the experimental observation of spectrum evolution that the bottom of the averaged spectrum gradually broadens with pump power increasing. Numerical results suggest that the transition could also happen under the condition of cavity linear phase delay bias change with fixed pump power. It is demonstrated that the peak power clamping effect and the normal dispersion are the key factors leading to the spectrum evolution. In addition, intermittent meta-stable states between GGS and NLP can be obtained when the cavity dispersion is chosen at small normal dispersion.

7.
Sleep Breath ; 25(1): 325-330, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32562172

RESUMEN

PURPOSE: To study neurochemical reactions to chronic intermittent hypoxia (CIH) in the hypoglossal nucleus (HN) of rats. METHODS: Adult male Sprague-Dawley rats (n = 12) were randomly divided into two groups (the CIH and the control group). The CIH rats were housed in a hypoxic chamber with the fraction of oxygen volume alternating between 21% and 5% by providing air for 60 s and then providing nitrogen for 60 s from 8:30 am to 16:30 pm each day for 35 days. The control group was housed in a cabin with normal oxygen levels. We studied the expression of c-fos protein, 5-hydroxytryptamine (5-HT) positive terminals, and its 2A receptors in hypoglossal nuclei by immunohistochemistry. RESULTS: The expression of c-fos, 5-HT positive terminals, and accordingly 5-HT 2A receptors in the CIH group were significantly higher than that in the controls (p < 0.05). The ventral side of the HN showed a clearly higher expression of 5-HT and its 2A receptors than the dorsal side (p < 0.05). CONCLUSION: There were 2 responses of the HN to CIH. First, CIH induced a higher expression of 5-HT positive terminals and its 2A receptors, and second, this reaction was much more evident in ventral side than in the dorsal side. We postulate that these responses may serve to be a protective and compensatory mechanism for CIH.


Asunto(s)
Nervio Hipogloso/metabolismo , Hipoxia/metabolismo , Bulbo Raquídeo/metabolismo , Animales , Modelos Animales de Enfermedad , Inmunohistoquímica , Masculino , Proteínas Proto-Oncogénicas c-fos/metabolismo , Distribución Aleatoria , Ratas , Ratas Sprague-Dawley , Receptor de Serotonina 5-HT2A/metabolismo , Serotonina/metabolismo
8.
Appl Microbiol Biotechnol ; 104(16): 7143-7153, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32623494

RESUMEN

The gut microbiota is crucial in the pathogenesis of type 2 diabetes mellitus (T2DM). However, the metabolism of T2DM patients is not well-understood. We aimed to identify the differences on composition and function of gut microbiota between T2DM patients with obesity and healthy people. In this study, 6 T2DM patients with obesity and 6 healthy volunteers were recruited, and metagenomic approach and bioinformatics analysis methods were used to understand the composition of the gut microbiota and the metabolic network. We found a decrease in the abundance of Firmicutes, Oribacterium, and Paenibacillus; this may be attributed to a possible mechanism and biological basis of T2DM; moreover, we identified three critical bacterial taxa, Bacteroides plebeius, Phascolarctobacterium sp. CAG207, and the order Acidaminococcales that can potentially be used for T2DM treatment. We also revealed the composition of the microbiota through functional annotation based on multiple databases and found that carbohydrate metabolism contributed greatly to the pathogenesis of T2DM. This study helps in elucidating the different metabolic roles of microbes in T2DM patients with obesity.


Asunto(s)
Bacterias/clasificación , Diabetes Mellitus Tipo 2/microbiología , Microbioma Gastrointestinal , Metagenoma , Obesidad/microbiología , Adulto , Bacterias/metabolismo , Biología Computacional , Diabetes Mellitus Tipo 2/fisiopatología , Heces/microbiología , Femenino , Voluntarios Sanos , Humanos , Masculino , Metagenómica , Persona de Mediana Edad
9.
Mol Cell Biochem ; 449(1-2): 207-218, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29679278

RESUMEN

Association studies suggest that TRß1 functions as a tumor suppressor. Thyroid hormone receptors (TRs) mediate transcriptional responses through a highly conserved DNA-binding domain (DBD). We previously constructed an artificially modified human TRß1 (m-TRß1) via the introduction of a 108-bp exon sequence into the corresponding position of the wild-type human TRß1 (TRß1) DBD. Studies confirmed that m-TRß1 was functional and could inhibit the proliferation of breast cancer MDA-MB-468 cells in vitro. To understand the role of m-TRß1 in liver tumor development, we adopted a gain-of-function approach by stably expressing TRß (m-TRß1 and TRß1) genes in a human hepatocarcinoma cell line, SK-hep1 (without endogenous TRß), and then evaluated the effects of the expressed TRß on cancer cell proliferation, migration, and tumor growth in cell-based studies and xenograft models. In the presence of 3,5,3-L-triiodothyronine (T3), the expression of TRß in SK-hep1 cells inhibited cancer cell proliferation and impeded tumor cell migration through the up-regulation of 4-1BB, Caspase-3, and Bak gene expression; down-regulation of Bcl-2 gene expression; and activation of the Caspase-3 protein. TRß expression in SK-hep1 led to less tumor growth in xenograft models. Additionally, the anti-tumor effect of m-TRß1 was stronger than that of TRß1. These data indicate that m-TRß1 can act as a tumor suppressor in hepatocarcinoma and its role was significantly better than that of TRß1.


Asunto(s)
Carcinoma Hepatocelular/metabolismo , Regulación Neoplásica de la Expresión Génica , Neoplasias Hepáticas/metabolismo , Receptores beta de Hormona Tiroidea , Proteínas Supresoras de Tumor/biosíntesis , Animales , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patología , Carcinoma Hepatocelular/terapia , Línea Celular Tumoral , Femenino , Xenoinjertos , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patología , Neoplasias Hepáticas/terapia , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Trasplante de Neoplasias , Receptores beta de Hormona Tiroidea/biosíntesis , Receptores beta de Hormona Tiroidea/genética , Proteínas Supresoras de Tumor/genética
10.
Environ Sci Technol ; 52(4): 2046-2054, 2018 02 20.
Artículo en Inglés | MEDLINE | ID: mdl-29301072

RESUMEN

Anthropogenic eutrophication has led to the increased occurrence of hypoxia in inland and coastal waters around the globe. While low dissolved oxygen conditions are known to be driven primarily by nutrient loading and water column stratification, the relative importance of these factors and their associated time scales are not well understood. Here, we explore these questions for Lake Erie, a large temperate lake that experiences widespread annual summertime hypoxia. We leverage a three-decade data set of summertime hypoxic extent (1985-2015) and examine the role of seasonal and long-term nutrient loading, as well as hydrometeorological conditions. We find that a linear combination of decadal total phosphorus loading from tributaries and springtime air temperatures explains a high proportion of the interannual variability in average summertime hypoxic extent (R2 = 0.71). This result suggests that the lake responds primarily to long-term variations in phosphorus inputs, rather than springtime or annual loading as previously assumed, which is consistent with internal phosphorus loading from lake sediments likely being an important contributing mechanism. This result also demonstrates that springtime temperatures have a substantial impact on summertime hypoxia, likely by impacting the timing of onset of thermal stratification. These findings imply that management strategies based on reducing tributary phosphorus loading would take several years to reap full benefits, and that projected future increases in temperatures are likely to exacerbate hypoxia in Lake Erie and other temperate lakes.


Asunto(s)
Lagos , Fósforo , Monitoreo del Ambiente , Eutrofización , Humanos , Hipoxia , Temperatura
11.
Lipids Health Dis ; 17(1): 188, 2018 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-30115076

RESUMEN

BACKGROUND: We investigated the baseline characterization of cardiovascular disease (CVD)-derived circulating miR-221-3p/222-3p in isolated low HDL-C phenotype (ILHP) to enhance our understanding on their molecular pathological pattern prior to disease onset. METHODS: We screened 174 asymptomatic subjects with isolated low HDL-C phenotype (n = 88) and normal lipid phenotype (n = 86), and detected circulating levels of CVD-derived circulating miR-221-3p/222-3p using TaqMan miRNA Real-time PCR detection system. RESULTS: We found the inverted pattern of decreased circulating miR-221-3p (0.415 [0.249, 1.004] vs 0.658 [0.347, 1.534], p = 0.002) versus increased miR-222-3p levels (0.379 [0.101, 0.701] vs 0.156 [0.043, 0.407], p < 0.001) in ILHP. The baseline levels of circulating miR-221-3p and miR-222-3p are correlated with serum HDL-C levels (miR-221-3p: r = 0.306, p < 0.001; miR-222-3p: r = - 0.201, p = 0.008). Gender-based analysis showed female-specific elevation of circulating miR-221-3p in asymptomatic individual. Multiple logistic regression analysis showed that circulating miR-222-3p is robustly independent factor (adjusted OR = 8.42, 95%CI: 2.53-27.98, p < 0.001) and significantly improved the performance of the predictive clinical model distinguished ILHP from normal lipid phenotype (AUC: 0.816, 95%CI (0.754, 0.879) vs AUC: 0.771, 95%CI (0.702, 0.840); Z = 2.169, p = 0.030). Moreover, the increased original Ct ratio of miR-221-3p to miR-222-3p in male ILHP (1.003 [0.927, 1.063] vs 0.927 [0.858, 0.967], p < 0.001) significantly enhanced the ability to classify male ILHP compared with the male predictive clinical model (AUC: 0.851, 95%CI (0.770, 0.933) vs AUC: 0.759, 95%CI (0.659, 0.859); Z = 2.474, p < 0.05). CONCLUSIONS: The inverted pattern of circulating miR-221-3p and miR-222-3p are potentially clinically actionable signature for molecular pathology in isolated low HDL-C phenotype.


Asunto(s)
HDL-Colesterol/sangre , MicroARNs/sangre , Apolipoproteínas E/genética , Área Bajo la Curva , Femenino , Genotipo , Humanos , Masculino , MicroARNs/genética , Persona de Mediana Edad , Fenotipo
12.
Angew Chem Int Ed Engl ; 57(5): 1300-1305, 2018 01 26.
Artículo en Inglés | MEDLINE | ID: mdl-29239090

RESUMEN

Axial chirality is a prevalent and important phenomenon in chemistry. Herein we report a combination of dynamic covalent chemistry and axial chirality for the development of a versatile platform for the binding and chirality sensing of multiple classes of mononucleophiles. An equilibrium between an open aldehyde and its cyclic hemiaminal within biphenyl derivatives enabled the dynamic incorporation of a broad range of alcohols, thiols, primary amines, and secondary amines with high efficiency. Selectivity toward different classes of nucleophiles was also achieved by regulating the distinct reactivity of the system with external stimuli. Through induced helicity as a result of central-to-axial chirality transfer, the handedness and ee values of chiral monoalcohol and monoamine analytes were reported by circular dichroism. The strategies introduced herein should find application in many contexts, including assembly, sensing, and labeling.

13.
J Am Chem Soc ; 138(1): 381-9, 2016 Jan 13.
Artículo en Inglés | MEDLINE | ID: mdl-26652793

RESUMEN

Dynamic covalent chemistry (DCC) has become a powerful tool for the creation of molecular assemblies and complex systems in chemistry and materials science. Herein we developed for the first time quantitative reactivity scales capable of correlation and prediction of the equilibrium of dynamic covalent reactions (DCRs). The reference reactions are based upon universal DCRs between imines, one of the most utilized structural motifs in DCC, and a series of O-, N-, and S- mononucleophiles. Aromatic imines derived from pyridine-2-carboxyaldehyde exhibit capability for controlling the equilibrium through distinct substituent effects. Electron-donating groups (EDGs) stabilize the imine through quinoidal resonance, while electron-withdrawing groups (EWGs) stabilize the adduct by enhancing intramolecular hydrogen bonding, resulting in curvature in Hammett analysis. Notably, unique nonlinearity induced by both EDGs and EWGs emerged in Hammett plot when cyclic secondary amines were used. This is the first time such a behavior is observed in a thermodynamically controlled system, to the best of our knowledge. Unified quantitative reactivity scales were proposed for DCC and defined by the correlation log K = S(N) (R(N) + R(E)). Nucleophilicity parameters (R(N) and S(N)) and electrophilicity parameters (R(E)) were then developed from DCRs discovered. Furthermore, the predictive power of those parameters was verified by successful correlation of other DCRs, validating our reactivity scales as a general and useful tool for the evaluation and modeling of DCRs. The reactivity parameters proposed here should be complementary to well-established kinetics based parameters and find applications in many aspects, such as DCR discovery, bioconjugation, and catalysis.

14.
Chemistry ; 21(22): 8207-13, 2015 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-25919126

RESUMEN

The use of dynamic covalent reactions (DCRs) is gaining popularity for the construction of self-assembling architectures. We have recently introduced DCRs that exchange alcohols and aldehydes to create hemiaminal ethers within tri(2-picolyl)amine (TPA) ligands, all of which are templated by Zn(II). To expand the scope of this assembly, aromatic imines derived from pyridine-2-carboxyaldehyde were explored as dynamic covalent receptors for di(2-picolyl)amine in the presence of Zn(II) to create TPA ligands that contain aminal linkages. This represents another metal-templated in situ multicomponent assembly. The stability of the assembly was successfully modulated through substituent effects, and the equilibrium constants from imines to aminals were correlated by a linear free energy relationship (LFER) with σ(+) values. Dynamic component exchange was investigated as a means of probing multiple equilibriums quantitatively in the system. Further, the mechanism was analyzed with a qualitative kinetics study. NMR spectra reveal the different extents of two competing pathways for assembly depending upon whether the aromatic amine has electron-withdrawing or electron-donating groups on the ring. Finally, mass spectral evidence supports the presence and differing extents of dominance of the two pathways as a function of the substituents.


Asunto(s)
Aminas/química , Hidrocarburos Aromáticos/química , Iminas/química , Ácidos Picolínicos/química , Aldehídos/síntesis química , Aldehídos/química , Aminas/síntesis química , Hidrocarburos Aromáticos/síntesis química , Iminas/síntesis química , Ligandos , Ácidos Picolínicos/síntesis química , Piridinas/síntesis química , Piridinas/química , Zinc/química
15.
J Org Chem ; 80(5): 2627-33, 2015 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-25674707

RESUMEN

In an effort to develop reactivity-based dynamic covalent bonding and to expand the scope and application of the dynamic covalent chemistry, in situ-generated simple generic iminium ions were utilized for the dynamic covalent binding of monoalcohols with high affinity. Hammett analysis was conducted to manipulate the equilibrium and correlate with the reactivity of reactants. The structural features of aldehydes and secondary amines were identified, and both polar and steric effects have significant impact on the binding. In particular, the substrates which can participate in π-π and polar-π interactions are able to afford apparent equilibrium constants in the magnitude of 10(4) M(-2), demonstrating the power of weak supramolecular forces to stabilize the dynamic covalent assembly. The generality of the assembly was validated with a series of mono secondary alcohols. To showcase the practicality of our system, chirality discrimination and ee measurement of chiral secondary alcohols were achieved.

16.
Environ Sci Technol ; 49(2): 800-7, 2015 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-25522015

RESUMEN

Hypoxia has been observed in the central basin of Lake Erie for decades. To understand the impact of various controlling factors, we analyze a record of hypoxic extents for Lake Erie for 1985­2012 and develop a parsimonious model of their interannual variability. We find that the 2012 North American drought and accompanying low tributary discharge was associated with a record-breaking hypoxic event in Lake Erie, whereas a record-setting harmful algal bloom in 2011 was likely associated with only mild hypoxia. River discharge and the timing of nutrient input therefore impact western basin bloom growth and central basin oxygen demand in distinct ways that merit further investigation. Overall, April to June tributary discharge, May to July soluble reactive phosphorus loading, July wind stress, and June northwesterly wind duration explain 82% of the interannual variability of hypoxia, and discharge alone explains 39%, indicating that meteorological factors need to be considered in the development of nutrient management strategies, especially as both extreme precipitation events and droughts become more frequent under a changing climate.


Asunto(s)
Sequías , Lagos/química , Oxígeno/química , Fósforo/análisis , Análisis de la Demanda Biológica de Oxígeno , Monitoreo del Ambiente/métodos , Eutrofización , Agua Dulce , Modelos Teóricos , América del Norte , Reproducibilidad de los Resultados , Ríos , Estaciones del Año , Viento
17.
Heart Lung Circ ; 24(7): 724-30, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25704294

RESUMEN

BACKGROUND: Previous studies confirmed that the intronic miRNAs participated in regulating host gene-primed biological processes. The coordinated roles of miR-28 with its host gene, LIM domain lipoma-preferred partner (LPP), remain unknown in atherosclerosis. METHODS: In this study, we determined to assess circulating levels of miR-28-5p in unstable angina patients, compared with age- and sex- matched control subjects by quantitative PCR. Furthermore, we attempted to explore whether miR-28-5p could influence the expression of ATP-binding cassette transporter A1 (ABCA1) and liver X receptor (LXR), major mediators of high density lipoprotein (HDL) synthesis and transportation in hepatic cells and macrophages. RESULTS: It was found that plasma levels of miR-28-5p were significantly increased in unstable angina patients with or without type 2 diabetes mellitus. Notably, miR-28-5p upregulated ABCA1 expression at transcription and translation levels, strongly correlated with translational activation of LXRα in HepG2 and THP-1-derived macrophages. CONCLUSIONS: Our findings suggest that circulating miR-28-5p, involved in LXRα-ABCA1 pathway, may be a potential biomarker for diagnosis and prognosis of unstable angina.


Asunto(s)
Transportador 1 de Casete de Unión a ATP/sangre , Angina Inestable/sangre , MicroARNs/sangre , Receptores Nucleares Huérfanos/sangre , Transducción de Señal , Anciano , Angina Inestable/diagnóstico , Biomarcadores/sangre , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/diagnóstico , Femenino , Células Hep G2 , Humanos , Receptores X del Hígado , Masculino , Persona de Mediana Edad , Pronóstico
18.
Environ Sci Technol ; 47(2): 899-905, 2013 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-23237424

RESUMEN

Hypoxic conditions, defined as dissolved oxygen (DO) concentrations below 2 mg/L, are a regular summertime occurrence in Lake Erie, but the spatial extent has been poorly understood due to sparse sampling. We use geostatistical kriging and conditional realizations to provide quantitative estimates of the extent of hypoxia in the central basin of Lake Erie for August and September of 1987 to 2007, along with their associated uncertainties. The applied geostatistical approach combines the limited in situ DO measurements with auxiliary data selected using the Bayesian Information Criterion. Bathymetry and longitude are found to be highly significant in explaining the spatial distribution of DO, while satellite observations of sea surface temperature and satellite chlorophyll are not. The hypoxic extent was generally lowest in the mid-1990s, with the late 1980s (1987, 1988) and the 2000s (2003, 2005) experiencing the largest hypoxic zones. A simple exponential relationship based on the squared average measured bottom DO explains 97% of the estimated variability in the hypoxic extent. The change in the observed maximum extent between August and September is found to be sensitive to the corresponding variability in the hypolimnion thickness.


Asunto(s)
Lagos/análisis , Oxígeno/análisis , Teorema de Bayes , Monitoreo del Ambiente , Incertidumbre
19.
Front Immunol ; 14: 1199273, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37465670

RESUMEN

Women worldwide are more likely to develop breast cancer (BC) than any other type of cancer. The treatment of BC depends on the subtype and stage of the cancer, such as surgery, radiotherapy, chemotherapy, and immunotherapy. Although significant progress has been made in recent years, advanced or metastatic BC presents a poor prognosis, due to drug resistance and recurrences. During embryonic development, myeloid-derived suppressor cells (MDSCs) develop that suppress the immune system. By inhibiting anti-immune effects and promoting non-immune mechanisms such as tumor cell stemness, epithelial-mesenchymal transformation (EMT) and angiogenesis, MDSCs effectively promote tumor growth and metastasis. In various BC models, peripheral tissues, and tumor microenvironments (TME), MDSCs have been found to amplification. Clinical progression or poor prognosis are strongly associated with increased MDSCs. In this review, we describe the activation, recruitment, and differentiation of MDSCs production in BC, the involvement of MDSCs in BC progression, and the clinical characteristics of MDSCs as a potential BC therapy target.


Asunto(s)
Neoplasias de la Mama , Células Supresoras de Origen Mieloide , Humanos , Femenino , Inmunoterapia , Sistema Inmunológico/patología , Microambiente Tumoral
20.
Toxics ; 11(7)2023 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-37505600

RESUMEN

Due to rapidly expanding crayfish consumption worldwide, the food safety of red swamp crayfish (Procambarus clarkii) is of great concern. China is the largest consumer and producer of crayfish globally. As of yet, it is unknown whether the main crayfish production cities in China are within safe levels of toxic heavy metals and metalloids. For 16 consecutive years, Qianjiang city ranked first in China in processing export volumes of red swamp crayfish. This study presents a comprehensive analysis of the enrichment levels and associated health risks of the species in Qianjiang. In our research, samples of four crayfish tissues, including the head, hepatopancreas, gills, and muscles, were collected from 38 sampling sites distributed in Qianjiang to evaluate the concentration levels of five heavy metals (Pb, Hg, Cd, As, and Cu). The concentration levels of all five metals in muscle did not surpass the national standard. Furthermore, eight significant correlations have been found. For further in-depth assess risk of crayfish in Qianjiang, estimated daily intake (EDI), target hazard quotient (THQ), carcinogenic risk (CR), and estimated maximum allowable consumption rates (CRmm) were evaluated in the abdomen muscle and hepatopancreas. The THQ values for each metal were found to be less than 1, while the CR values were below 10-6. Additionally, the CRmm for adults was determined to be 17.2 meals per month. These findings, based on the analysis of five metallic elements included in this study, suggest that the consumption of crayfish abdomen muscle in Qianjiang does not pose any significant health risks. However, it is noteworthy that certain regions exhibit elevated levels of arsenic in the hepatopancreas, surpassing the national standard, thereby rendering them unsuitable for excessive consumption. In general, the findings can be used to provide guidance for safe dietary practices in China.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA