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1.
Proc Natl Acad Sci U S A ; 116(38): 18854-18859, 2019 09 17.
Artículo en Inglés | MEDLINE | ID: mdl-31481607

RESUMEN

Atmospheric oxygen has evolved from negligible levels in the Archean to the current level of about 21% through 2 major step rises: The Great Oxidation Event (GOE) in the early Proterozoic and the Neoproterozoic Oxygenation Event (NOE) during the late Proterozoic. However, most previous methods for constraining the time of atmospheric oxygenation have relied on evidence from sedimentary rocks. Here, we investigate the temporal variations of the Th/U of arc igneous rocks since 3.0 billion y ago (Ga) and show that 2 major Th/U decreases are recorded at ca. 2.35 Ga and ca. 0.75 Ga, coincident with the beginning of the GOE and NOE. The decoupling of U from Th is predominantly caused by the significant rise of atmospheric oxygen. Under an increasingly oxidized atmosphere condition, more uranium in the surface environment became oxidized from the water-insoluble U4+ to the water-soluble U6+ valance and incorporated in the sea water and altered oceanic crust. Eventually, the subduction of this altered oceanic crust produced the low-Th/U signature of arc igneous rocks. Therefore, the sharp decrease of Th/U in global arc igneous rocks may provide strong evidence for the rise of atmospheric oxygen. We suggest that the secular Th/U evolution of arc igneous rocks could be an effective geochemical indicator recording the global-scale atmospheric oxygen variation.

2.
Toxicol Appl Pharmacol ; 315: 90-101, 2017 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-27986624

RESUMEN

Recently, we reported that Ilexgenin A exhibits anti-cancer activities and induces cell arrest. Here, we investigated the effect of Ilexgenin A on the inflammation, angiogenesis and tumor growth of hepatocellular carcinoma (HCC). Our current study revealed that Ilexgenin A significantly inhibited the inflammatory cytokines TNF-α and IL-6 levels and downregulated pro-angiogenic factor VEGF production and transcription in HepG2 cells. The underlying mechanism for Ilexgenin A effects appears to be through inhibiting STAT3 and PI3K pathways. Furthermore, we found that not only Ilexgenin A inhibited STAT3 and PI3K pathways in HepG2 cells but also blocked these signaling pathways in HUVECs. Most importantly, by employing two HCC xenografts models - HepG2 and H22, we showed that Ilexgenin A reduced tumor growth and exhibited synergy effect with Sorafenib. ELISA assay, histological analysis and immunohistochemistry examination revealed that the expression of VEGF and MVD was significantly decreased after the treatment with Ilexgenin A and the combination. Moreover, Ilexgenin A could enhance caspase-3/7 activity in vitro and transmission electron microscope indicated that the combination induced evident apoptosis of tumor cells and caused the structural changes of mitochondria in vivo. Although no apparent adverse effects occurred during the treatment period, Sorafenib monotherapy elicited hepatotoxicity for specific expression in the increased level of AST and the ratio of AST/ALT. However, the combination could remedy this adverse effect. In conclusion, the results described in the present study identifies Ilexgenin A as a promising therapeutic candidate that modulates inflammation, angiogenesis, and HCC growth.


Asunto(s)
Inhibidores de la Angiogénesis/farmacología , Antiinflamatorios/farmacología , Carcinoma Hepatocelular/patología , Neoplasias Hepáticas/patología , Niacinamida/análogos & derivados , Compuestos de Fenilurea/farmacología , Fosfatidilinositol 3-Quinasas/metabolismo , Factor de Transcripción STAT3/metabolismo , Triterpenos/farmacología , Animales , Proliferación Celular/efectos de los fármacos , Sinergismo Farmacológico , Células Hep G2 , Humanos , Ratones , Ratones Endogámicos BALB C , Niacinamida/farmacología , Fosforilación , Sorafenib
3.
Acta Chim Slov ; 63(4): 856-863, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-28004099

RESUMEN

A new trifluoromethylsulfonate salt of 2-[(3-chloropyridinium-2-yl)hydrazonomethyl]-6-methoxyphenol, (HL)CF3SO3, and its copper(II) and cobalt(III) complexes, [CuL(OH2)]CF3SO3 · 0.5H2O (1) and [CoL2]CF3SO3 · CH3OH (2), were prepared and characterized by physico-chemical methods and single crystal X-ray analysis. A trifluoromethylsulfonate anion is present in each of the compounds. The Cu atom in complex 1 is coordinated by the phenolate O, imino N and pyridine N atoms of L ligand, giving square planar geometry. The Co atom in complex 2 is coordinated by two phenolate O, two imino N and two pyridine N atoms from two L ligands, giving octahedral geometry. The three compounds were tested in vitro for their antibacterial activities.


Asunto(s)
Antibacterianos/síntesis química , Antibacterianos/farmacología , Cobalto/química , Cobre/química , Ácidos Sulfónicos/síntesis química , Ácidos Sulfónicos/farmacología , Antibacterianos/química , Complejos de Coordinación/química , Cristalografía por Rayos X , Pruebas de Sensibilidad Microbiana , Modelos Moleculares , Estructura Molecular , Ácidos Sulfónicos/química
4.
Guang Pu Xue Yu Guang Pu Fen Xi ; 35(5): 1357-64, 2015 May.
Artículo en Zh | MEDLINE | ID: mdl-26415460

RESUMEN

With the development of remote sensing technology and imaging spectrometer, the resolution of hyperspectral remote sensing image has been continually improved, its vast amount of data not only improves the ability of the remote sensing detection but also brings great difficulties for analyzing and processing at the same time. Band selection of hyperspectral imagery can effectively reduce data redundancy and improve classification accuracy and efficiency. So how to select the optimum band combination from hundreds of bands of hyperspectral images is a key issue. In order to solve these problems, we use spectral clustering algorithm based on graph theory. Firstly, taking of the original hyperspectral image bands as data points to be clustered , mutual information between every two bands is calculated to generate the similarity matrix. Then according to the graph partition theory, spectral decomposition of the non-normalized Laplacian matrix generated by the similarity matrix is used to get the clusters, which the similarity between is small and the similarity within is large. In order to achieve the purpose of dimensionality reduction, the inter-class separability factor of feature types on each band is calculated, which is as the reference index to choose the representative bands in the clusters furthermore. Finally, the support vector machine and minimum distance classification methods are employed to classify the hyperspectral image after band selection. The method in this paper is different from the traditional unsupervised clustering method, we employ spectral clustering algorithm based on graph theory and compute the interclass separability factor based on a priori knowledge to select bands. Comparing with traditional adaptive band selection algorithm and band index based on automatically subspace divided algorithm, the two sets of experiments results show that the overall accuracy of SVM is about 94. 08% and 94. 24% and the overall accuracy of MDC is about 87. 98% and 89. 09%, when the band selection achieves a relatively optimal number of clusters using the method propoesd in this paper. It effectively remains spectral information and improves the classification accuracy.

5.
Guang Pu Xue Yu Guang Pu Fen Xi ; 35(2): 557-62, 2015 Feb.
Artículo en Zh | MEDLINE | ID: mdl-25970932

RESUMEN

As the rotation speed of ground based hyperspectral imaging system is too fast in the image collection process, which exceeds the speed limitation, there is data missed in the rectified image, it shows as the_black lines. At the same time, there is serious distortion in the collected raw images, which effects the feature information classification and identification. To solve these problems, in this paper, we introduce the each component of the ground based hyperspectral imaging system at first, and give the general process of data collection. The rotation speed is controlled in data collection process, according to the image cover area of each frame and the image collection speed of the ground based hyperspectral imaging system, And then the spatial orientation model is deduced in detail combining with the star scanning angle, stop scanning angle and the minimum distance between the sensor and the scanned object etc. The oriented image is divided into grids and resampled with new spectral. The general flow of distortion image corrected is presented in this paper. Since the image spatial resolution is different between the adjacent frames, and in order to keep the highest image resolution of corrected image, the minimum ground sampling distance is employed as the grid unit to divide the geo-referenced image. Taking the spectral distortion into account caused by direct sampling method when the new uniform grids and the old uneven grids are superimposed to take the pixel value, the precise spectral sampling method based on the position distribution is proposed. The distortion image collected in Lao Si Cheng ruin which is in the Zhang Jiajie town Hunan province is corrected through the algorithm proposed on above. The features keep the original geometric characteristics. It verifies the validity of the algorithm. And we extract the spectral of different features to compute the correlation coefficient. The results show that the improved spectral sampling method is better than the direct sampling method. It provides the reference for the similar product used on the ground.

6.
Guang Pu Xue Yu Guang Pu Fen Xi ; 34(7): 1983-9, 2014 Jul.
Artículo en Zh | MEDLINE | ID: mdl-25269321

RESUMEN

In order to correct the image distortion in the hyperspectral camera side-scan geometric Imaging, the image pixel geo-referenced algorithm was deduced in detail in the present paper, which is suitable to the linear push-broom camera side-scan imaging on the ground in any direction. It takes the orientation of objects in the navigation coordinates system into account. Combined with the ground sampling distance of geo-referenced image and the area of push broom imaging, the general process of geo-referenced image divided into grids is also presented. The new image rows and columns will be got through the geo-referenced image area dividing the ground sampling distance. Considering the error produced by round rule in the pixel grids generated progress, and the spectral mixing problem caused by traditional direct spectral sampling method in the process of image correction, the improved spectral sampling method based on the weighted fusion method was proposed. It takes the area proportion of adjacent pixels in the new generated pixel as coefficient and then the coefficients are normalized to avoid the spectral overflow. So the new generated pixel is combined with the geo-referenced adjacent pixels spectral. Finally the amounts of push-broom imaging experiments were taken on the ground, and the distortion images were corrected according to the algorithm proposed above. The results show that the linear image distortion correction algorithm is valid and robust. At the same time, multiple samples were selected in the corrected images to verify the spectral data. The results indicate that the improved spectral sampling method is better than the direct spectral sampling algorithm. It provides reference for the application of similar productions on the ground.

7.
Front Pharmacol ; 15: 1410479, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38919254

RESUMEN

Metabolic syndrome (MetS) represents a constellation of metabolic abnormalities, typified by obesity, hypertension, hyperglycemia, and hyperlipidemia. It stems from intricate dysregulations in metabolic pathways governing energy and substrate metabolism. While comprehending the precise etiological mechanisms of MetS remains challenging, evidence underscores the pivotal roles of aberrations in lipid metabolism and insulin resistance (IR) in its pathogenesis. Notably, nicotinamide N-methyltransferase (NNMT) has recently surfaced as a promising therapeutic target for addressing MetS. Single nucleotide variants in the NNMT gene are significantly correlated with disturbances in energy metabolism, obesity, type 2 diabetes (T2D), hyperlipidemia, and hypertension. Elevated NNMT gene expression is notably observed in the liver and white adipose tissue (WAT) of individuals with diabetic mice, obesity, and rats afflicted with MetS. Knockdown of NNMT elicits heightened energy expenditure in adipose and hepatic tissues, mitigates lipid accumulation, and enhances insulin sensitivity. NNMT catalyzes the methylation of nicotinamide (NAM) using S-adenosyl-methionine (SAM) as the donor methyl group, resulting in the formation of S-adenosyl-l-homocysteine (SAH) and methylnicotinamide (MNAM). This enzymatic process results in the depletion of NAM, a precursor of nicotinamide adenine dinucleotide (NAD+), and the generation of SAH, a precursor of homocysteine (Hcy). Consequently, this cascade leads to reduced NAD+ levels and elevated Hcy levels, implicating NNMT in the pathogenesis of MetS. Moreover, experimental studies employing RNA interference (RNAi) strategies and small molecule inhibitors targeting NNMT have underscored its potential as a therapeutic target for preventing or treating MetS-related diseases. Nonetheless, the precise mechanistic underpinnings remain elusive, and as of yet, clinical trials focusing on NNMT have not been documented. Therefore, further investigations are warranted to elucidate the intricate roles of NNMT in MetS and to develop targeted therapeutic interventions.

8.
Metabolites ; 14(6)2024 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-38921477

RESUMEN

The complex process of aging leads to a gradual deterioration in the function of cells, tissues, and the entire organism, thereby increasing the risk of disease and death. Nicotinamide N-methyltransferase (NNMT) has attracted attention as a potential target for combating aging and its related pathologies. Studies have shown that NNMT activity increases over time, which is closely associated with the onset and progression of age-related diseases. NNMT uses S-adenosylmethionine (SAM) as a methyl donor to facilitate the methylation of nicotinamide (NAM), converting NAM into S-adenosyl-L-homocysteine (SAH) and methylnicotinamide (MNA). This enzymatic action depletes NAM, a precursor of nicotinamide adenine dinucleotide (NAD+), and generates SAH, a precursor of homocysteine (Hcy). The reduction in the NAD+ levels and the increase in the Hcy levels are considered important factors in the aging process and age-related diseases. The efficacy of RNA interference (RNAi) therapies and small-molecule inhibitors targeting NNMT demonstrates the potential of NNMT as a therapeutic target. Despite these advances, the exact mechanisms by which NNMT influences aging and age-related diseases remain unclear, and there is a lack of clinical trials involving NNMT inhibitors and RNAi drugs. Therefore, more in-depth research is needed to elucidate the precise functions of NNMT in aging and promote the development of targeted pharmaceutical interventions. This paper aims to explore the specific role of NNMT in aging, and to evaluate its potential as a therapeutic target.

9.
Guang Pu Xue Yu Guang Pu Fen Xi ; 33(10): 2777-82, 2013 Oct.
Artículo en Zh | MEDLINE | ID: mdl-24409735

RESUMEN

Aiming at the spectral distortion produced in PCA fusion process, the present paper proposes an improved low spectral distortion PCA fusion method. This method uses NCUT (normalized cut) image segmentation algorithm to make a complex hyperspectral remote sensing image into multiple sub-images for increasing the separability of samples, which can weaken the spectral distortions of traditional PCA fusion; Pixels similarity weighting matrix and masks were produced by using graph theory and clustering theory. These masks are used to cut the hyperspectral image and high-resolution image into some sub-region objects. All corresponding sub-region objects between the hyperspectral image and high-resolution image are fused by using PCA method, and all sub-regional integration results are spliced together to produce a new image. In the experiment, Hyperion hyperspectral data and Rapid Eye data were used. And the experiment result shows that the proposed method has the same ability to enhance spatial resolution and greater ability to improve spectral fidelity performance.

10.
In Vitro Cell Dev Biol Anim ; 59(9): 706-716, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37831321

RESUMEN

Osteoporosis is a metabolic condition distinguished by the degradation of bone microstructure and mechanical characteristics. Traditional Chinese medicine (TCM) has been employed in China for the treatment of various illnesses. Naringin, an ingredient found in Drynariae TCM, is known to have a significant impact on bone metabolism. For this research, we studied the precise potential effect of Drynaria Naringin on protecting against bone loss caused by stress deficiency. In this study, a tail-suspension (TS) test was performed to establish a mouse model with hind leg bone loss. Some mice received subcutaneous injections of Drynaria Naringin for 30 d. Trabecular bone microarchitecture was evaluated using micro-computed tomography analysis and bone histological analysis. Bone formation and resorption markers were quantified in blood samples from mice or in the supernatant of MC3T3-E1 cells by ELISA analysis, Western blotting, and PCR. Immunofluorescence was utilized to visualize the location of ß-catenin. Additionally, siRNA was employed to knockdown-specific genes in the cells. Our findings highlight the efficacy of Drynaria Naringin in protecting against the deterioration of bone loss and promoting bone formation and Rspo1 expression in a mouse model following the TS test. Specifically, in vitro experiments also indicated that Drynaria Naringin may promote osteogenesis through the Wnt/ß-catenin signalling pathway. Moreover, our results suggest that Drynaria Naringin upregulates the expression of Rspo1/Lgr4, leading to the promotion of osteogenesis via the Wnt/ß-catenin signalling pathway. Therefore, Drynaria Naringin holds potential as a therapeutic medication for osteoporosis. Drynaria Naringin alleviates bone loss deterioration caused by mechanical stress deficiency through the Rspo1/Lgr4-mediated Wnt/ß-catenin signalling pathway.


Asunto(s)
Osteoporosis , Polypodiaceae , Animales , Ratones , beta Catenina/metabolismo , Diferenciación Celular , Osteogénesis/genética , Osteoporosis/tratamiento farmacológico , Osteoporosis/etiología , Polypodiaceae/química , Estrés Mecánico , Vía de Señalización Wnt , Microtomografía por Rayos X/efectos adversos
11.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 30(5): 1337-1342, 2022 Oct.
Artículo en Zh | MEDLINE | ID: mdl-36208232

RESUMEN

OBJECTIVE: To investigate the effect of dihydroartemisinin (DHA) combined with arsenic trioxide (ATO) on the viability and apoptosis of acute myeloid leukemia (AML) FLT3-ITD mutant cell line MOLM13 and its mechanism. METHODS: MOLM13 cells were treated with DHA or ATO alone or in combination. The viability of MOLM13 cells was detected by CCK-8 assay, cell proliferation was observed by colony formation assay, cell apoptosis and reactive oxygen species (ROS) level were measured by flow cytometry, and the expression levels of proteins related to apoptosis were detected by Western blot. RESULTS: Compared with the control group, treatment with DHA and ATO alone or in combination could inhibit cell proliferation, activate ROS formation, and finally induce cell apoptosis. DHA in combination with ATO produced a synergistic effect. Western blot analysis showed that DHA combined with ATO could significantly upregulate the level of c-PARP and activate apoptosis via inhibition of Mcl-1 and FLT3-ITD. CONCLUSION: DHA combined with ATO induces the apoptosis of FLT3-ITD AML cell line MOLM13 by inhibiting Mcl-1 pathway and activating FLT3-ITD protein degradation.


Asunto(s)
Artemisininas , Leucemia Mieloide Aguda , Apoptosis , Trióxido de Arsénico/uso terapéutico , Artemisininas/farmacología , Artemisininas/uso terapéutico , Línea Celular Tumoral , Humanos , Leucemia Mieloide Aguda/tratamiento farmacológico , Proteína 1 de la Secuencia de Leucemia de Células Mieloides , Inhibidores de Poli(ADP-Ribosa) Polimerasas/farmacología , Inhibidores de Poli(ADP-Ribosa) Polimerasas/uso terapéutico , Especies Reactivas de Oxígeno/metabolismo , Especies Reactivas de Oxígeno/farmacología , Especies Reactivas de Oxígeno/uso terapéutico , Tirosina Quinasa 3 Similar a fms
12.
Front Microbiol ; 13: 976334, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36016795

RESUMEN

Vibrio parahaemolyticus is a marine pathogen thought to be the leading cause of seafood-borne gastroenteritis globally, urgently requiring efficient management methods. V. parahaemolyticus encodes 12 resistance/nodulation/division (RND) efflux systems. However, research on these systems is still in its infancy. In this study, we discovered that the inactivation of VmeL, a membrane fusion protein within the RND efflux systems, led to reduction of the ability of biofilm formation. Further results displayed that the decreased capacity of Congo red binding and the colony of ΔvmeL is more translucent compared with wild type strains, suggested reduced biofilm formation due to decreased production of biofilm exopolysaccharide upon vmeL deletion. In addition, the deletion of vmeL abolished surface swarming and swimming motility of V. parahaemolyticus. Additionally, deletion of vmeL weakened the cytotoxicity of V. parahaemolyticus towards HeLa cells, and impaired its virulence in a murine intraperitoneal infection assay. Finally, through RNA-sequencing, we ascertained that there were 716 upregulated genes and 247 downregulated genes in ΔvmeL strain. KEGG enrichment analysis revealed that quorum sensing, bacterial secretion systems, ATP-binding cassette transporters, and various amino acid metabolism pathways were altered due to the inactivation of vmeL. qRT-PCR further confirmed that genes accountable to the type III secretion system (T3SS1) and lateral flagella were negatively affected by vmeL deletion. Taken together, our results suggest that VmeL plays an important role in pathogenicity, making it a good target for managing infection with V. parahaemolyticus.

13.
J Tradit Chin Med ; 31(1): 36-8, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21563504

RESUMEN

OBJECTIVE: To observe the therapeutic effect and safety of using the hooked needle-shaped knife to treat the stenosing tenovaginitis of flexor digitorum. METHODS: Sixty outpatients were divided into a treatment group of 30 cases treated by using the hooked needle-shaped knife, and a control group of 30 cases treated by block therapy. 6 months later, the alleviation of pain in the affected finger during movement, under pressure, traction and finger-bending anti-resistance was compared before and after treatment. RESULTS: The alleviation of pain during movement, under pressure, traction and finger-bending anti-resistance was much better in the treatment group than that of the control group (P < 0.01), with a effective rate of 93.3% in the treatment group and 80.0% in the control group (P < 0.01). CONCLUSION: The micro-wound technique using the hooked needle-shaped knife has definite effect and safety for stenosing tenovaginitis of flexor digitorum.


Asunto(s)
Atrapamiento del Tendón/cirugía , Adulto , Anciano , Femenino , Dedos/cirugía , Humanos , Masculino , Microcirugia , Persona de Mediana Edad , Instrumentos Quirúrgicos , Resultado del Tratamiento
14.
Acta Chim Slov ; 67(2): 581-585, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33855569

RESUMEN

A pair of new mononuclear zinc(II) complexes with hydrazone ligands 4-methoxybenzoic acid (1-pyridin-2-ylmethylidene)hydrazide (HLa) and benzoic acid (1-pyridin-2-ylethylidene)hydrazide (HLb) were prepared. They are [Zn(La)2] (1) and [Zn(Lb)2] (2). The complexes were characterized by physico-chemical methods and single crystal X-ray determination. The tridentate hydrazone ligands coordinate to the Zn atoms through the pyridine nitrogen, imino nitrogen and enolate oxygen atoms. The Zn atom in each complex is six coordinated by two hydrazone ligands, to form octahedral coordination. The complexes have effective activities against the bacteria Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas fluorescens.


Asunto(s)
Antibacterianos/farmacología , Complejos de Coordinación/farmacología , Hidrazonas/farmacología , Antibacterianos/síntesis química , Bacterias/efectos de los fármacos , Complejos de Coordinación/síntesis química , Hidrazonas/síntesis química , Ligandos , Pruebas de Sensibilidad Microbiana , Zinc/química
15.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 28(3): 753-757, 2020 Jun.
Artículo en Zh | MEDLINE | ID: mdl-32552932

RESUMEN

OBJECTIVE: To investigate the effects of dihydroartemisinin (DHA) on the proliferation and apoptosis of human T-cell acute lymphoblastic leukemia (T-ALL) Jurkat cell. METHODS: The effects of DHA on the proliferation of Jurkat cells and the recovery of DHA-inhibited cell viability by N-acetyl-L-cysteine (NAC) were examined by CCK-8 assay. Flow cytometry was performed to analyze the cell apoptosis and generation of reactive oxygen species (ROS). Western-blot was used to detected protein expression of DNA damage-related genes, as well as apoptosis-associated genes, respectively. RESULTS: DHA inhibited the proliferation of Jurkat cells, and shows a concentration-dependent manner(r =0.936), and NAC could partially restore the activity of DHA on cell proliferation inhibition. With the increase of drug concentration, the apoptosis rate (r =0.946) and ROS accumulation was increased (r =0.965). Western blot showed that the protein expressions of DNA damage-related gene γ-H2AX and apoptosis-related genes p53, c-Caspase3, BAX and cPARP were significantly increased, and BCL-2 protein expression was decreased. CONCLUSION: DHA can induce ROS production in Jurkat cells, which can cause DNA damage, activate the P53 apoptotic pathway, and promote apoptosis of cells.


Asunto(s)
Leucemia-Linfoma Linfoblástico de Células T Precursoras , Apoptosis , Artemisininas , Humanos , Células Jurkat , Estrés Oxidativo , Especies Reactivas de Oxígeno
16.
Sci Bull (Beijing) ; 65(11): 958-964, 2020 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-36747429

RESUMEN

Supercritical CO2 appearing as bubbles in hydrothermal vents was identified in the south part of the Okinawa Trough using in situ Raman spectroscopy. Significantly, the N2 peak in supercritical CO2 is much larger than those in seawater and vent fluids, indicating that supercritical CO2 enriches N2 from the surrounding environment. Considering that the partial pressures of CO2 and N2 in the Earth's proto-atmosphere were ~10-20 MPa, supercritical CO2 with high N2 was likely the dominant CO2 phase near the water-air interface in the early history of the Earth, which promoted the synthesis, pre-enrichment and preservation of amino acids and other organic matters that are essential to the origin of life.

17.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 28(1): 88-92, 2020 Feb.
Artículo en Zh | MEDLINE | ID: mdl-32027258

RESUMEN

OBJECTIVE: To study the effects of dihydroartemisinin (DHA) on the proliferation and apoptosis of acute myeloid leukemia (AML) cells. METHODS: The effects of DHA on the proliferation of acute myeloid leukemia cells and the inhibitory effect of Z-VAD-FMK on the DHA-induced cell apoptosis were detected by CCK-8 assay. The expression level of cleaved-caspased 3 was detected by indirect immunofluorescence. Western blot was used to quantify the protein expression of PTEN, p-Akt, AKT, ß-actin, and the apoptosis-associated proteins, such as C-PARP, Cleaved-caspase3 and Caspase3 respectively. RESULTS: DHA induced the AML cell apoptosis with concentration-dependent manner (rKasumi-1=-0.959, rKG-1=-0.956). The DHA could induce the accumulation of cleaved-caspase 3 and C-PARP in AML cells, activate PTEN gene and inhibited Akt phosphorylation. Apoptosis inhibitor Z-VAD-FMK could partially restored the activity of DHA-inhibited cell proliferation. CONCLUSION: Dihydroartemisinin induces AML cell apoptosis by inhibition of PTEN/AKT pathway. Dihydroartemisinin is expected to be a safe and effective drug for treatment of acute myeloid leukemia.


Asunto(s)
Leucemia Mieloide Aguda , Apoptosis , Artemisininas , Línea Celular Tumoral , Proliferación Celular , Humanos , Fosfohidrolasa PTEN , Proteínas Proto-Oncogénicas c-akt , Transducción de Señal
18.
Nat Commun ; 10(1): 3408, 2019 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-31363091

RESUMEN

Over the Earth's evolutionary history, the style of plate subduction has evolved through time due to the secular cooling of the mantle. While continuous subduction is a typical feature of modern plate tectonics, a stagnant-lid tectonic regime with localized episodic subduction likely characterized the early Earth. The timing of the transition between these two subduction styles bears important insights into Earth's cooling history. Here we apply a statistical analysis to a large geochemical dataset of mafic rocks spanning the last 3.5 Ga, which shows an increasing magnitude of alkali basaltic magmatism beginning at ca. 2.1 Ga. We propose that the rapid rise of continental alkali basalts correlates with an abruptly decreasing degree of mantle melting resulting from the enhanced cooling of the mantle at ca. 2.1 Ga. This might be a consequence of the initiation of continuous subduction, which recycled increasing volumes of cold oceanic crust into the mantle.

19.
Res Vet Sci ; 84(3): 434-9, 2008 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17707446

RESUMEN

OBJECTIVE: The present study was conducted to investigate the effect of early feed restriction on protein kinase Calpha (PKCalpha) expression in pulmonary arterioles, which has been revealed to promote pulmonary vascular remodeling in pulmonary hypertensive broilers. METHODS: A total of 270day-old mixed sex commercial broilers were randomly distributed to a normal temperature control group (NT), a low temperature control group (LT) and a low temperature plus feed restriction group (LR). The PHS incidence, the right/total ventricular weight ratio (RV/TV), the vessel wall area/vessel total area ratio (WA/TA), the mean media thickness in pulmonary arterioles (mMTPA) and the expression of PKCalpha in the pulmonary arterioles were measured weekly. RESULTS: Low temperature treatment significantly increased the PHS mortality. The RV/TV, WA/TA and mMTPA values of group LT were significantly elevated compared with those of group NT on d 35 and 42. The LT chickens had increased PKCalpha expression compared with their NT counterparts on d 28 and afterwards. Feed restriction reduced the PHS mortality, RV/TV, WA/TA and mMTPA in cold-exposed broilers. The LR chickens had much lower PKCalpha expression in pulmonary arterioles than the LT chickens. CONCLUSION: Early time feed restriction inhibited pulmonary vascular remodeling in broilers, which might be partly attributed to reduced PKCalpha expression in pulmonary arterioles.


Asunto(s)
Alimentación Animal , Arteriolas/enzimología , Dieta Reductora/veterinaria , Proteína Quinasa C-alfa/metabolismo , Circulación Pulmonar , Animales , Peso Corporal , Pollos , Frío , Hipertensión Pulmonar/etiología , Hipertensión Pulmonar/veterinaria , Inmunohistoquímica , Enfermedades de las Aves de Corral/etiología , Temperatura
20.
Zhonghua Yu Fang Yi Xue Za Zhi ; 42(1): 43-6, 2008 Jan.
Artículo en Zh | MEDLINE | ID: mdl-18512327

RESUMEN

OBJECTIVE: To study whether plasma viral load testing is helpful to exclude ones free from Human immunodeficiency virus (HIV) infections from suspects in HIV antibody detections. METHODS: 19 Specimens, which showed disconcordant results of the two HIV EIA testing (S/CO < 6) and indeterminated results of Western blot (WB) test, were selected. Viral load of the specimens were detected. A six-month follow up survey in detecting HIV antibody was conducted in these subjects. RESULTS: None of these 19 cases was observed to be positive HIV viral loads and there was no any progress in WB bands development during the follow-up period. The possibility of HIV infection could be excluded. CONCLUSION: When the specimens react with very low intensity in both EIA and WB, negative viral load result is conducive to exclude negative subjects from suspects in HIV antibody detections.


Asunto(s)
Serodiagnóstico del SIDA , Infecciones por VIH/diagnóstico , Carga Viral , Anticuerpos Anti-VIH/sangre , Infecciones por VIH/sangre , Humanos
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