Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 29
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Inorg Chem ; 63(1): 824-832, 2024 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-38114300

RESUMEN

The catalytic oxidation of ethylbenzene (EB) into acetophenone (AP) is a vibrant area, with a growing number of researchers paying attention to this thematic investigation. Herein, we demonstrate that spinel-type (Co,Mn)(Co,Mn)2O4 can function as an efficient catalyst for the solvent-free oxidation of EB with molecular oxygen. The incorporation of Mn into the Co3O4 network can break the local structural symmetry of Co-O-Co linkages due to the bond competition, inducing the formation of an asymmetrical Co-O-Mn configuration with an electron local exchange interaction. The Co-O-Mn sites can facilitate the perturbation of nonpolar O2 and thus contribute to the generation of abundant •O2- species for initiating the oxidation of EB. We envision that this study not only provides a promising catalyst for EB oxidation but also affords a new insight into the design of advanced spinel oxides for selective oxidation reactions.

2.
Environ Res ; 244: 117856, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38065391

RESUMEN

Understanding controls of dissolved oxygen (DO) concentrations in reservoirs is important as they are important for fisheries and a significant driver of greenhouse gas emissions. The latter is of global significance as IPCC inventories now require greenhouse gas emissions from artificial reservoirs to be included. Declines in dissolved oxygen (DO) concentrations in lakes and reservoirs have been linked to climate change and human activity. However, these effects can vary widely in any given region under various meteorological conditions. There is a clear need to know how changes in weather patterns affect DO in reservoirs by changing internal processes. Based on a six-year (2016-2021) high-frequency (twice a week) dataset from a shallow urban reservoir (Xinglinwan Reservoir) in subtropical China, the long-term (six years) and short-term (8-72-h) drivers of DO concentrations in surface waters were evaluated. Over the past six years, the concentration of DO has gradually decreased in the reservoir from 2016 to 2021. Multivariate adaptive regression spline (MARS) models were developed to identify the key factors explaining variability in DO and partial least squares path models (PLS-PM) were used to explore the short-term relationships between DO and environmental variables in rainy and dry (non-rain) periods, separately. We identified three key drivers operating on different time scales. First, the long-term decline of DO in Xinglinwan Reservoir from 2016 to 2021 was best explained by anthropogenic nutrient inputs. Second, rainy periods prior to sampling reduced DO concentrations indirectly by affecting the algal biomass and nutrient concentrations. This effect varied in complexity with the duration of the rainfall period. Third, water temperature best explained DO concentrations during dry periods, while wind reduced DO by reducing algal biomass. We conclude that anthropogenic nutrient and organic matter inputs drive long-term oxygen declines in urban subtropical reservoirs, while meteorological factors determine short-term variability in DO concentrations.


Asunto(s)
Monitoreo del Ambiente , Gases de Efecto Invernadero , Humanos , Lagos , Agua , Oxígeno/análisis , China
3.
J Environ Sci (China) ; 112: 140-151, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34955197

RESUMEN

Urbanization often exerts multiple effects on aquatic and terrestrial organisms, including changes in biodiversity, species composition and ecosystem functions. However, the impacts of urbanization on river phytoplankton in subtropical urbanizing watersheds remain largely unknown. Here, we explored the effects of urbanization on phytoplankton community structure (i.e., biomass, community composition and diversity) and function (i.e., resource use efficiency) in a subtropical river at watershed scale in southeast China over 6 years. A total of 318 phytoplankton species belonging into 120 genera and 7 phyla were identified from 108 samples. Bacillariophyta biomass showed an increasing trend with increasing urbanization level. The phytoplankton community shifted from Chlorophyta dominance in rural upstream waters to Bacillariophyta dominance in urbanized downstream waters. Furthermore, phytoplankton diversity and resource use efficiency (RUE = phytoplankton biomass/total phosphorus) were significantly decreased with increasing urbanization level from upstream to downstream. Phytoplankton RUE exhibited a significant positive correlation with species richness, but a negative correlation with phytoplankton evenness. The variation in environmental factors (turbidity, total nitrogen, NH4+-N, total phosphorus, PO43--P and percentage urbanized area) was significantly correlated with phytoplankton diversity and RUE. Overall, our results revealed the influence of urbanization on phytoplankton community structure and ecosystem function was due to its altering the environmental conditions. Therefore, human-driven urbanization may play crucial roles in shaping the structure and function of phytoplankton communities in subtropical rivers, and the mechanism of this process can provide important information for freshwater sustainable uses, watershed management and conservation.


Asunto(s)
Fitoplancton , Urbanización , Biodiversidad , China , Ecosistema , Humanos , Ríos , Estaciones del Año
4.
Exp Cell Res ; 392(2): 112034, 2020 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-32339606

RESUMEN

Programmed death-ligand 1 (PD-L1) expression on the surface of tumour cells can cause tumour immune evasion. Benefits of combining anti-PD-L1 therapy with nab-paclitaxel in patients with advanced triple-negative breast cancer (TNBC) have been reported. However, some patients cannot tolerate the immune-related adverse effects (irAEs) caused by antibody-based immunotherapy. BRD4 is a member of the bromodomain and extra-terminal domain (BET) family. BRD4 inhibition has shown antitumour effects in many tumours, but its role in TNBC has not been definitively concluded. In particular, the immune regulation of BRD4 in TNBC has been rarely studied. In this study, we used JQ1, a BET inhibitor, and small interfering RNAs (siRNAs) targeting BRD4 to explore the influence of BRD4 on PD-L1 expression in TNBC. The results indicated that BRD4 inhibition suppressed PD-L1 expression and the PD-L1 upregulation induced by interferon-γ (IFN-γ). In the in vivo experiments, we found that JQ1 not only reduced the PD-L1 expression level but also changed the proportions of T lymphocyte subsets in the spleens of tumour-bearing mice, which helped to relieve immunosuppression. Briefly, our study reveals that BRD4 regulates PD-L1 expression and may provide a potential method for blocking the programmed death 1 (PD-1)/PD-L1 immune checkpoint in TNBC.


Asunto(s)
Azepinas/farmacología , Antígeno B7-H1/antagonistas & inhibidores , Biomarcadores de Tumor/metabolismo , Proteínas de Ciclo Celular/antagonistas & inhibidores , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Factores de Transcripción/antagonistas & inhibidores , Triazoles/farmacología , Neoplasias de la Mama Triple Negativas/patología , Animales , Apoptosis , Antígeno B7-H1/genética , Antígeno B7-H1/metabolismo , Biomarcadores de Tumor/genética , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Proliferación Celular , Femenino , Humanos , Interferón gamma/metabolismo , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Persona de Mediana Edad , Pronóstico , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Neoplasias de la Mama Triple Negativas/genética , Neoplasias de la Mama Triple Negativas/metabolismo , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de Xenoinjerto
5.
Hum Mol Genet ; 27(10): 1794-1808, 2018 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-29547888

RESUMEN

The TMEM127 tumor suppressor gene encodes a transmembrane protein of unknown function mutated in pheochromocytomas and, rarely, in renal cancers. Tumors with inactivating TMEM127 mutations have increased mTORC1 signaling by undefined mechanisms. Here we report that TMEM127 interacts with the lysosome-anchored complex comprised of Rag GTPases, the LAMTOR pentamer (or 'ragulator') and vATPase, which controls amino acid-mediated mTORC1 activation. We found that under nutrient-rich conditions TMEM127 expression reduces mTORC1 recruitment to Rags. In addition, TMEM127 interacts with LAMTOR in an amino acid-dependent manner and decreases the LAMTOR1-vATPase association, while TMEM127-vATPase binding requires intact lysosomal acidification but is amino acid independent. Conversely, both murine and human cells lacking TMEM127 accumulate LAMTOR proteins in the lysosome. Consistent with these findings, pheochromocytomas with TMEM127 mutations have increased levels of LAMTOR proteins. These results suggest that TMEM127 interactions with ragulator and vATPase at the lysosome contribute to restrain mTORC1 signaling in response to amino acids, thus explaining the increased mTORC1 activation seen in TMEM127-deficient tumors.


Asunto(s)
Neoplasias de las Glándulas Suprarrenales/genética , Proteínas Portadoras/genética , Proteínas de la Membrana/genética , Feocromocitoma/genética , Neoplasias de las Glándulas Suprarrenales/metabolismo , Neoplasias de las Glándulas Suprarrenales/patología , Aminoácidos/genética , Animales , Regulación de la Expresión Génica , Genes Supresores de Tumor , Humanos , Péptidos y Proteínas de Señalización Intracelular , Lisosomas/genética , Lisosomas/metabolismo , Diana Mecanicista del Complejo 1 de la Rapamicina/genética , Ratones , Complejos Multiproteicos/genética , Mutación , Feocromocitoma/metabolismo , Feocromocitoma/patología , Transducción de Señal
6.
BMC Cancer ; 19(1): 446, 2019 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-31088428

RESUMEN

BACKGROUND: TIMP-2 gene plays an important role in the development of breast cancer. The present study was conducted to evaluate whether TIMP-2 gene polymorphisms are associated with breast cancer risk in a Han Chinese cohort. METHODS: Six single nucleotide polymorphisms (SNPs) within the TIMP-2 gene in 571 breast cancer and 578 healthy control subjects were genotyped through the Agena MassARRAY. Logistic regression analysis was used to assess the influence of TIMP-2 polymorphisms on breast cancer. Functional annotation of TIMP-2 variants and TIMP-2 expression were analyzed by bioinformatics. RESULTS: Bioinformatics analysis found that rs4789936 was likely to affect transcription factor binding, motifs, DNase footprint, and DNase peaks; and TIMP-2 was under-expressed in breast cancer, the risk allele of rs4789936 was associated with increased expression of TIMP-2 in peripheral blood samples. Importantly, individuals carrying TIMP-2 rs2277698 T allele have a 19% lower risk of breast cancer than individuals with allele C, providing protection (OR = 0.81, 95%CI = 0.67-0.99, p = 0.041). In the breast cancer patients with c-erb positive and PR positive, when the CC genotype was used as a reference, individuals carrying the TT genotype increased the risk of breast cancer. Haplotype analysis showed "TCC" was associated with a reduced risk of breast cancer (OR = 0.79, 95%CI = 0.63-0.97, p = 0.028). CONCLUSION: Our study indicated that TIMP-2 rs2277698 was associated with breast cancer susceptibility.


Asunto(s)
Neoplasias de la Mama/genética , Regulación hacia Abajo , Polimorfismo de Nucleótido Simple , Inhibidor Tisular de Metaloproteinasa-2/genética , Adulto , Neoplasias de la Mama/etnología , Estudios de Casos y Controles , China/etnología , Femenino , Regulación Neoplásica de la Expresión Génica , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Haplotipos , Humanos , Modelos Logísticos , Persona de Mediana Edad
7.
Cancer Sci ; 109(12): 3865-3873, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30259603

RESUMEN

Thymoquinone (TQ, 2-methyl-5-isopropyl-1,4-benzoquinone), a bioactive constituent extracted from the seeds of Nigella sativa, has been proved to exert anti-tumor efficiency in various cancers. Autophagy is a self-digestion phenomenon, and its role in tumor formation and progression remains controversial. In the present study, we investigated the effects of TQ on renal cell cancer (RCC) cell lines (786-O and ACHN) using wound healing assay, transwell assay and western blot analysis. We found that TQ effectively inhibited the metastatic capacity of RCC cells in vitro, which was also verified in a xenograft model. Meanwhile, we observed LC3 puncta and detected the expression of LC3 in TQ-treated RCC cells, and then found that autophagy was induced by TQ in 786-O and ACHN cell lines. In addition, TQ inhibited the migration and invasion as well as the EMT in RCC cells in an autophagy-dependent manner. To further explore the underlying mechanism, we detected the AMPK/mTOR signaling pathway. The results indicated that TQ inhibited the metastasis of RCC cells by inducing autophagy via AMPK/mTOR signaling pathway. In conclusion, our findings provide a novel therapeutic strategy that aims at TQ-induced autophagy in RCC treatment.


Asunto(s)
Proteínas Quinasas Activadas por AMP/metabolismo , Benzoquinonas/administración & dosificación , Carcinoma de Células Renales/tratamiento farmacológico , Neoplasias Renales/tratamiento farmacológico , Serina-Treonina Quinasas TOR/metabolismo , Animales , Autofagia , Benzoquinonas/farmacología , Carcinoma de Células Renales/metabolismo , Línea Celular Tumoral , Movimiento Celular , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Humanos , Neoplasias Renales/metabolismo , Ratones , Metástasis de la Neoplasia , Transducción de Señal/efectos de los fármacos , Ensayos Antitumor por Modelo de Xenoinjerto
8.
Cancer Sci ; 109(5): 1503-1512, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29575477

RESUMEN

Distinguishing the surface markers of cancer stem cells (CSCs) is a useful method for early diagnosis and treatment of tumors, as CSCs may participate in tumorigenesis and metastasis by migrating into the circulatory system. However, the potential targets of CSCs are expressed at low levels in the natural state and are always changing. Thus, dynamic screening has been reported to be an effective measure for exploring CSC markers. In recent years, diverse single-chain variable fragments (scFvs) have been widely used in immunotherapy. In this study, we determined that the scFvs, screened using RD, had a high affinity to microspheres and could inhibit their progression. We also observed that the selected scFvs underwent evolution in vitro, and antitumor-associated proteins were successfully expressed. Combined with chemotherapy, the scFvs had a synergistic effect on the inhibition of the microspheres' progression in vitro and in vivo, which could be ascribed to their high affinity for stem-like cells and the inhibition of the microspheres' collective behaviors. In addition, proteins inhibiting CD44+ /CD24+ and MAPK were involved. Our data indicated that dynamic screening of the scFvs in a natural state was of great significance in the inhibition of the microspheres in vitro and in vivo.


Asunto(s)
Neoplasias de la Mama/tratamiento farmacológico , Células Madre Neoplásicas/efectos de los fármacos , Ribosomas/genética , Anticuerpos de Cadena Única/farmacología , Animales , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Técnicas de Visualización de Superficie Celular , Sinergismo Farmacológico , Quimioterapia , Femenino , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Ratones , Microesferas , Células Madre Neoplásicas/metabolismo , Ribosomas/inmunología , Ensayos Antitumor por Modelo de Xenoinjerto
9.
Pediatr Neurosurg ; 52(5): 336-342, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28848151

RESUMEN

BACKGROUND: Infratentorial subdural hygromas causing secondary occlusive hydrocephalus are extremely rare in children. Only a handful of cases have been reported in the literature. METHODS: We present a case of a 6-month-old infant with an occipital fracture and slow enlargement of a posterior fossa subdural hygroma that culminated in obstructive hydrocephalus. We give a review of the literature on post-traumatic posterior fossa hygroma with secondary occlusive hydrocephalus and discuss its pathogenesis and the mechanism of its later resolution, as well as the available treatment options. RESULTS: A temporary external ventricular drain led to acute relief of the hydrocephalus and subsequent complete resolution of the subdural hygroma. CONCLUSION: Temporary external ventricular drain placement led to complete resolution of the subdural hygroma and hydrocephalus. We recommend close clinical follow-up, and imaging if indicated, for as long as 4 weeks after trauma with occipital skull fractures.


Asunto(s)
Fosa Craneal Posterior/cirugía , Hidrocefalia/cirugía , Fracturas Craneales/cirugía , Efusión Subdural/cirugía , Fosa Craneal Posterior/diagnóstico por imagen , Fosa Craneal Posterior/lesiones , Humanos , Hidrocefalia/diagnóstico por imagen , Hidrocefalia/etiología , Lactante , Masculino , Fracturas Craneales/complicaciones , Fracturas Craneales/diagnóstico por imagen , Efusión Subdural/diagnóstico por imagen , Efusión Subdural/etiología
10.
J Ethnopharmacol ; 325: 117886, 2024 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-38355027

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: PolyphyllinVI (PPⅥ) is the main bioactive component of Chonglou which is a traditional Chinese herbal with various effects, including antitumor, anti-inflammatory, and analgesia. AIM OF THE STUDY: This study aimed to investigate the properties and mechanisms of the analgesia of PPⅥ by using neuropathic pain (NPP) mice. MATERIALS AND METHODS: The potential targets and mechanisms of PPⅥ in alleviating NPP were excavated based on the network pharmacology. Subsequently, the construction of a spared nerve injury (SNI) mice model was used to evaluate the effect of PPⅥ on NPP and the expression of the P2X3 receptor. We identified the signaling pathways of PPⅥ analgesia by RNA sequencing. RESULTS: The results of network pharmacology showed that BCL2, CASP3, JUN, STAT3, and TNF were the key targets of the analgesic effect of PPⅥ. PPⅥ increased the MWT and TWL of SNI mice and decreased the level of P2X3 receptors in the dorsal root ganglion (DRG) and spinal cord (SC). Additionally, PPⅥ reduced the release of pro-inflammatory mediators (TNF-α, IL-1ß, and IL-6) in the DRG, SC, and serum. Based on the KEGG enrichment of differentially expressed genes (DEGs) identified by RNA-Seq, PPVI may relieve NPP by regulating the AMPK/NF-κB signaling pathway. Western blotting results showed that the AMPK signaling pathway was activated, followed by inhibition of the NF-κB signaling pathway. CONCLUSION: PPⅥ increased the MWT and TWL of SNI mice maybe by inhibiting the expression of the P2X3 receptor and the release of inflammatory mediators. The properties of the analgesia of PPⅥ may be based on the AMPK/NF-κB pathway.


Asunto(s)
Neuralgia , Receptores Purinérgicos P2X3 , Ratas , Ratones , Animales , Ratas Sprague-Dawley , Receptores Purinérgicos P2X3/metabolismo , FN-kappa B/metabolismo , Proteínas Quinasas Activadas por AMP/metabolismo , Neuralgia/metabolismo , Ganglios Espinales
11.
Materials (Basel) ; 17(1)2023 Dec 27.
Artículo en Inglés | MEDLINE | ID: mdl-38204006

RESUMEN

Interatomic potentials play a crucial role in the molecular dynamics (MD) simulation of silicon carbide (SiC). However, the ability of interatomic potentials to accurately describe certain physical properties of SiC has yet to be confirmed, particularly for hexagonal SiC. In this study, the mechanical, thermal, and defect properties of four SiC structures (3C-, 2H-, 4H-, and 6H-SiC) have been calculated with multiple interatomic potentials using the MD method, and then compared with the results obtained from density functional theory and experiments to assess the descriptive capabilities of these interatomic potentials. The results indicate that the T05 potential is suitable for describing the elastic constant and modulus of SiC. Thermal calculations show that the Vashishta, environment-dependent interatomic potential (EDIP), and modified embedded atom method (MEAM) potentials effectively describe the vibrational properties of SiC, and the T90 potential provides a better description of the thermal conductivity of SiC. The EDIP potential has a significant advantage in describing point defect formation energy in hexagonal SiC, and the GW potential is suitable for describing vacancy migration in hexagonal SiC. Furthermore, the T90 and T94 potentials can effectively predict the surface energies of the three low-index surfaces of 3C-SiC, and the Vashishta potential exhibits excellent capabilities in describing stacking fault properties in SiC. This work will be helpful for selecting a potential for SiC simulations.

12.
Zhongguo Zhen Jiu ; 43(8): 876-80, 2023 Aug 12.
Artículo en Zh | MEDLINE | ID: mdl-37577881

RESUMEN

Jingjin (muscle region of meridian) is a distal diagnosis and treatment system of the sinew/fascia disorders on the base of the concept of jin in TCM. Jin should be a particular palpable structure rather than a single anatomic structure with a specific distributing course. Yizhi weishu refers to a idea running through the whole process of diagnosis and treatment of sinew/fascia disorders, in which, the results, obtained by the overall observation and palpation of patient's sinew/fascia structure, are taken as the criteria of treatment. Yitong weishu (taking the sites of sensitivity or tenderness as the points) verifies this idea in practice. Under the guidance of yizhi weishu, through identifying the primary from the secondary, and regulating yin and yang, the spasticity and flaccidity of sinews/fascia can be cured and the induced diseases treated. The diagnosis and treatment system of jingjin, based on yizhi weishu, develops the original jingjin theory with vague concept involved, formulates a systematic thinking of treatment for sinew/fascia disorders and provides a new approach to clinical treatment.


Asunto(s)
Terapia por Acupuntura , Meridianos , Humanos , Espasticidad Muscular
13.
Int J Pharm ; 638: 122923, 2023 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-37030641

RESUMEN

In high shear wet granulation (HSWG), the interaction mechanism between binder and powder with different sugar content is still unclear. Herein, the law and mechanism of the interaction between binder and powder were studied on the molecular level by combining experiment analysis through the Kriging model and molecular dynamics (MD) simulation. For the sticky powder with high sugar content, the ethanol in the binder played a pivotal role in dispersing water into powders, and the amount of water determined the growth of granules. In the saturating stage, the reduction of sugar content facilitates the penetration of ethanol molecules. The concentration of ethanol determines whether the mixture is blended uniformly in the merging stage. The simulation results are consistent with the actual situation and explain the competition mechanism of interaction with binder and powder. Therefore, this research offers an efficient strategy for the in-depth understanding of the HSWG process where the powder is sticky, as well as providing guidelines for the practical application of preparation for Traditional Chinese Medicine (TCM) granules.


Asunto(s)
Simulación de Dinámica Molecular , Agua , Polvos , Etanol , Azúcares , Tamaño de la Partícula , Composición de Medicamentos/métodos
14.
Sci Rep ; 13(1): 20247, 2023 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-37985686

RESUMEN

This research focuses on the evolution of mechanical behavior of bimodal mixtures undergoing compaction and diametrical compression. The clusters were built and discrete element method (DEM) was used to investigate the densification process and micromechanics of bimodal mixtures. Additionally, a more comprehensive investigate of the respective breakage of the bimodal mixtures has been carried out. On this basis, qualitative and quantitative analysis of the compressive force, force chain, contact bonds and density field evolution characteristics of the clusters are investigated during the compression process. The entire loading process of the clusters is divided into three stages: rearrangement, breakage and elastic-plastic deformation. Additionally, there are differences in the evolution of micromechanics behavior of different particles in the bimodal mixture, with pregelatinized starch breakage and deformation occurring before microcrystalline cellulose. With the tablet deformation, the fragmentation process of the tablet started at the point of contact and extended toward the center, and the curvature of the force chain increased. This approach may potentially hold a valuable new information relevant to important transformation forms batch manufacturing to advanced manufacturing for the oral solid dosage form.

15.
Sci Total Environ ; 827: 154172, 2022 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-35231504

RESUMEN

The global increase in dominance of toxic blooms of cyanobacteria has severely impacted aquatic ecosystems and threatened human health for decades. Although it has been shown that high levels of rainfall may inhibit the growth of bloom-forming cyanobacteria, it is still unclear how cyanobacteria respond to short-term rainfall events. Based on five-year (2016-2020) high-frequency (half-week) sampling data from a shallow eutrophic urban reservoir in subtropical China, we explored the short-term effects of rainfall events on cyanobacterial biomass (CBB) by constructing generalized additive models of CBB in rainy periods during warm (April to September) and cool (December and January) months, respectively. We find evidence in support of the hypotheses that short-term rainfall events significantly reduce CBB in warm months, but the opposite response was observed in the cool months. We also highlight a difference in the factors explaining CBB decreases in warm months (precipitation, air temperature, relative humidity, dissolved oxygen and total phosphorus) compared with factors explaining the response of CBB in cool months (sunshine hours, pH and total carbon). In particular, meteorological factors (precipitation, wind speed and sunlight) might drive changes in water temperature and hydro-dynamics of the reservoir, thereby causing a rapid reduction of CBB after rainfall events in warm months. This varying response of cyanobacteria to short-term rainfall events in the shallow eutrophic subtropical reservoir may also be expected in temperate or cool lakes as climate change effects become stronger.


Asunto(s)
Cianobacterias , Eutrofización , China , Ecosistema , Humanos , Lagos/microbiología , Fitoplancton , Estaciones del Año
16.
Biomolecules ; 11(12)2021 11 27.
Artículo en Inglés | MEDLINE | ID: mdl-34944423

RESUMEN

Emerging evidence shows that mitochondria fusion/fission imbalance is related to the occurrence of hyperglycemia-induced vascular injury. To study the temporal dynamics of mitochondrial fusion and fission, we observed the alteration of mitochondrial fusion/fission proteins in a set of different high-glucose exposure durations, especially in the early stage of hyperglycemia. The in vitro results show that persistent cellular apoptosis and endothelial dysfunction can be induced rapidly within 12 hours' high-glucose pre-incubation. Our results show that mitochondria maintain normal morphology and function within 4 hours' high-glucose pre-incubation; with the extended high-glucose exposure, there is a transition to progressive fragmentation; once severe mitochondria fusion/fission imbalance occurs, persistent cellular apoptosis will develop. In vitro and in vivo results consistently suggest that mitochondrial fusion/fission homeostasis alterations trigger high-glucose-induced vascular injury. As the guardian of mitochondria, AMPK is suppressed in response to hyperglycemia, resulting in imbalanced mitochondrial fusion/fission, which can be reversed by AMPK stimulation. Our results suggest that mitochondrial fusion/fission's staged homeostasis may be a predictive factor of diabetic cardiovascular complications.


Asunto(s)
Diabetes Mellitus Experimental/complicaciones , Glucosa/efectos adversos , Mitocondrias/metabolismo , Lesiones del Sistema Vascular/metabolismo , Animales , Diabetes Mellitus Experimental/metabolismo , Modelos Animales de Enfermedad , Células Endoteliales de la Vena Umbilical Humana , Humanos , Masculino , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Ratones , Dinámicas Mitocondriales , Lesiones del Sistema Vascular/etiología
17.
BMJ Case Rep ; 14(3)2021 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-33782071

RESUMEN

Spontaneous dissection of the major arteries of the neck is known to increase the risk of stroke or transient ischaemic attack in young and middle-aged adults. Most of the reported cases of arterial dissections in the neck involve one or both paired extracranial carotid or vertebral arteries. Spontaneous dissection of the bilateral internal carotid and vertebral arteries is extremely rare. We report a case of spontaneous bilateral internal carotid artery and vertebral artery dissection while using a prescribed pill for weight loss which contained amphetamine derivative. A review of literature is also provided.


Asunto(s)
Disección de la Arteria Carótida Interna , Ataque Isquémico Transitorio , Disección de la Arteria Vertebral , Adulto , Arteria Carótida Interna/diagnóstico por imagen , Disección de la Arteria Carótida Interna/diagnóstico por imagen , Disección , Humanos , Persona de Mediana Edad , Arteria Vertebral , Disección de la Arteria Vertebral/diagnóstico por imagen , Disección de la Arteria Vertebral/tratamiento farmacológico
18.
Cureus ; 13(1): e12908, 2021 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-33654593

RESUMEN

Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) is a complex group of disorders with multisystem involvement that have a wide range of biochemical and genetic defects. The earliest symptoms of MELAS typically include easy fatigability, muscle weakness, encephalopathy with stroke-like episodes, recurrent headaches and seizures. The pathogenesis of stroke-like episodes manifesting as focal deficits like acute cortical blindness is not fully understood. We present an eight-year-old, right-handed boy with MELAS confirmed by the presence of pathogenic missense variant mutation (mt.3243A>G) presenting with acute intermittent reversible episodes of cortical blindness and Anton-Babinski Syndrome secondary to concurrent occipital lobe seizures captured during video electroencephalography (V-EEG) monitoring, in addition to the neuro-imaging which was not consistent with acute ischemic stroke. This case highlights the importance of the V-EEG monitoring besides clinical testing and radiographic correlation during acute cortical blindness episodes in MELAS as occipital lobe seizures could be a part of the symptomatology.

19.
Front Cardiovasc Med ; 8: 720605, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34540920

RESUMEN

Background: Invasive blood pressure (IBP) measurement is common in the intensive care unit, although its association with in-hospital mortality in critically ill patients with hypertension is poorly understood. Methods and Results: A total of 11,732 critically ill patients with hypertension from the eICU-Collaborative Research Database (eICU-CRD) were enrolled. Patients were divided into 2 groups according to whether they received IBP. The primary outcome in this study was in-hospital mortality. Propensity score matching (PSM) and inverse probability of treatment weighing (IPTW) models were used to balance the confounding covariates. Multivariable logistic regression was used to evaluate the association between IBP measurement and hospital mortality. The IBP group had a higher in-hospital mortality rate than the no IBP group in the primary cohort [238 (8.7%) vs. 581 (6.5%), p < 0.001]. In the PSM cohort, the IBP group had a lower in-hospital mortality rate than the no IBP group [187 (8.0%) vs. 241 (10.3%), p = 0.006]. IBP measurement was associated with lower in-hospital mortality in the PSM cohort (odds ratio, 0.73, 95% confidence interval, 0.59-0.92) and in the IPTW cohort (odds ratio, 0.81, 95% confidence interval, 0.67-0.99). Sensitivity analyses showed similar results in the subgroups with high body mass index and no sepsis. Conclusions: In conclusion, IBP measurement was associated with lower in-hospital mortality in critically ill patients with hypertension, highlighting the importance of IBP measurement in the intensive care unit.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA