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1.
Proc Natl Acad Sci U S A ; 118(13)2021 03 30.
Artículo en Inglés | MEDLINE | ID: mdl-33753486

RESUMEN

Microbial variations in the human gut are harbored in temporal and spatial heterogeneity, and quantitative prediction of spatiotemporal dynamic changes in the gut microbiota is imperative for development of tailored microbiome-directed therapeutics treatments, e.g. precision nutrition. Given the high-degree complexity of microbial variations, subject to the dynamic interactions among host, microbial, and environmental factors, identifying how microbiota colonize in the gut represents an important challenge. Here we present COmputing the DYnamics of microbiota (CODY), a multiscale framework that integrates species-level modeling of microbial dynamics and ecosystem-level interactions into a mathematical model that characterizes spatial-specific in vivo microbial residence in the colon as impacted by host physiology. The framework quantifies spatiotemporal resolution of microbial variations on species-level abundance profiles across site-specific colon regions and in feces, independent of a priori knowledge. We demonstrated the effectiveness of CODY using cross-sectional data from two longitudinal metagenomics studies-the microbiota development during early infancy and during short-term diet intervention of obese adults. For each cohort, CODY correctly predicts the microbial variations in response to diet intervention, as validated by available metagenomics and metabolomics data. Model simulations provide insight into the biogeographical heterogeneity among lumen, mucus, and feces, which provides insight into how host physical forces and spatial structure are shaping microbial structure and functionality.


Asunto(s)
Colon/fisiología , Conducta Alimentaria/fisiología , Microbioma Gastrointestinal/fisiología , Modelos Biológicos , Obesidad/dietoterapia , Adulto , Variación Biológica Individual , Colon/microbiología , Estudios Transversales , Conjuntos de Datos como Asunto , Heces/microbiología , Humanos , Hidrodinámica , Lactante , Estudios Longitudinales , Metabolómica , Metagenómica , Obesidad/sangre , Obesidad/metabolismo , Obesidad/microbiología , Análisis Espacio-Temporal
2.
Eur J Anaesthesiol ; 41(3): 234-244, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38038408

RESUMEN

BACKGROUND: The relationship between Alzheimer's disease biomarkers and postoperative complications, such as postoperative delirium (POD) and postoperative cognitive dysfunction (POCD), remains a subject of ongoing debate. OBJECTIVE: This meta-analysis aimed to determine whether there is an association between perioperative Alzheimer's disease biomarkers and postoperative complications. DESIGN: We conducted a meta-analysis of observational clinical studies that explored the correlation between Alzheimer's disease biomarkers and POD or POCD in patients who have undergone surgery, following PRISMA guidelines. The protocol was previously published (INPLASY: INPLASY202350001). DATA SOURCES: A comprehensive search was conducted across PubMed, Embase, Web of Science, and Cochrane databases until March 2023. ELIGIBILITY CRITERIA: Surgical patients aged at least 18 years, studies focusing on POD or POCD, research involving Alzheimer's disease biomarkers, including Aß or tau in blood or cerebrospinal fluid (CSF), and availability of the full text. RESULTS: Our meta-analysis included 15 studies: six focusing on POD and nine on POCD. The findings revealed a negative correlation between preoperative CSF ß-amyloid 42 (Aß42) levels and the onset of POD [mean difference -86.1, 95% confidence interval (CI), -114.15 to -58.05, I2 : 47%]; this association was strongly supported by trial sequential analysis (TSA). A similar negative correlation was discerned between preoperative CSF Aß42 levels and the incidence of POCD (-165.01, 95% CI, -261.48 to -68.53, I2 : 95%). The TSA also provided robust evidence for this finding; however, the evidence remains insufficient to confirm a relationship between other Alzheimer's disease biomarkers [ß-amyloid 40 (Aß40), total tau (T-tau), phosphorylated tau (P-tau), and Aß42/T-tau ratio] and POD or POCD. CONCLUSION: The study results indicate a negative correlation between preoperative CSF Aß42 levels and the occurrence of both POD and POCD. Future investigations are warranted to identify the predictive cutoff value of preoperative CSF Aß42 for POD and POCD.


Asunto(s)
Enfermedad de Alzheimer , Disfunción Cognitiva , Delirio del Despertar , Complicaciones Cognitivas Postoperatorias , Humanos , Adolescente , Adulto , Enfermedad de Alzheimer/diagnóstico , Enfermedad de Alzheimer/líquido cefalorraquídeo , Estudios Prospectivos , Disfunción Cognitiva/diagnóstico , Disfunción Cognitiva/epidemiología , Disfunción Cognitiva/etiología , Péptidos beta-Amiloides/líquido cefalorraquídeo , Complicaciones Posoperatorias/diagnóstico , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Complicaciones Cognitivas Postoperatorias/diagnóstico , Complicaciones Cognitivas Postoperatorias/epidemiología , Complicaciones Cognitivas Postoperatorias/etiología , Biomarcadores/líquido cefalorraquídeo , Fragmentos de Péptidos
3.
Inorg Chem ; 62(13): 5158-5167, 2023 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-36951294

RESUMEN

Because the accurate and rapid detection of antibiotics and pH plays an important role in biological systems and environmental fields, developing suitable and efficient sensors that can simultaneously detect antibiotics and pH has become important. In this work, we successfully designed and synthesized two new one-dimensional coordination polymers based on the mixed ligands L [N,N'-bis(4-methylpyridin-4-yl)-2,6-naphthalene dicarboxylamide] and H2CPG [3-(4-chlorophenyl)glutaric acid], [M(L)(HCPG)2(H2O)2] (M = Co for CP 1, and M = Ni for CP 2), which were structurally characterized by single-crystal X-ray diffraction, infrared spectroscopy, powder X-ray diffraction, and thermogravimetric analysis. CP 1 and CP 2 can be used as ultraversatile fluorescent sensors, which can sense erythromycin (ERY) and oxacillin (OXC) by turn-on fluorescent enhancement and detect furaltadone (FTD) via the turn-off fluorescent quenching effect, separately. The concentration ranges of different analytes sensed by CPs 1 and 2 were 0-0.046 and 0-0.069 mM for ERY, 0-0.04 and 0-0.028 mM for OXC, and 0-0.155 and 0-0.019 mM for FTD, respectively. Moreover, CP 2 can effectively sense pH, in both a wide pH range and the fine physiological range. The sensors have a rapid luminescence response, good recyclability, and excellent fluorescence stability. More importantly, they not only represent the first example of detecting ERY or OXC based on fluorescent CPs but also are the very rare ultraversatile fluorescent sensors. The fluorescent sensing mechanism for antibiotics and pH was discussed in detail.


Asunto(s)
Antibacterianos , Demencia Frontotemporal , Humanos , Oxacilina , Eritromicina , Colorantes , Polímeros , Concentración de Iones de Hidrógeno
4.
Sensors (Basel) ; 23(6)2023 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-36991753

RESUMEN

Surface urban heat islands (SUHIs) are essential for evaluating urban thermal environments. However, current quantitative studies of SUHIs ignore the thermal radiation directionality (TRD), which directly affects study precision; furthermore, they fail to assess the effects of TRD characteristics at different land-use intensities, on the quantitative studies of SUHIs. To bridge this research gap, this study eliminates the interference of atmospheric attenuation and daily temperature variation factors, in quantifying the TRD based on land surface temperature (LST), from MODIS data and station air temperature data for Hefei (China) from 2010-2020. The influence of TRD on SUHI intensity quantification was evaluated by comparing the TRD under different land-use intensities in Hefei. The results show that: (1) daytime and nighttime directionality can reach up to 4.7 K and 2.6 K, and occur in areas with the highest and medium urban land-use intensity, respectively. (2) There are two significant TRD hotspots for daytime urban surfaces, where the sensor zenith angle is approximately the same as the forenoon solar zenith angle, and where the sensor zenith angle is near its nadir in the afternoon. (3) The TRD can contribute up to 2.0 K to the results of assessing the SUHI intensity based on satellite data, which is approximately 31-44% of the total SUHI in Hefei.

5.
Inorg Chem ; 61(28): 10694-10704, 2022 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-35785788

RESUMEN

Controlling the orderly assembly of molecular building blocks for the formation of the desired architectural, chemical, and physical properties of the resulting solid-state materials remains a long-term goal and deserves to be examined. In this work, we propose a patterning strategy for modular assembly and structural regulation of mixed-ligand uranyl coordination polymers (CPs) through the combination of couples of organic ligands with complementary molecular geometry and well-matched coordination modes. By using a 5-(p-tolyldiazenyl)isophthalic acid ligand (H2ptdi) with different rigid linear bicarboxylic acid linkers to construct a well-defined ladder-like pattern, five novel isostructural uranyl coordination polymers, [(UO)2(ptdi)(bdc)0.5](dma) (1), [(UO)2(ptdi)(bpdc)0.5](dma) (2), [(UO)2(ptdi)(tpdc)0.5](dma) (3), [(UO)2(ptdi)(ndc)0.5](dma) (4), and [(UO)2(ptdi) (pdc)0.5](dma) (5) {H2bdc, 1,4-dicarboxybenzene; H2bpdc, 4,4'-biphenyldicarboxylic acid; H2tpdc, terphenyl-4,4″-dicarboxylic acid; H2ndc, 2,6-naphthalenedicarboxylic acid; H2pdc, 1,6-pyrenedicarboxylic acid; [dma]+, [(CH3)2NH2]+}, were successfully synthesized. Structural analysis reveals that 1-5 have similar ladder-like units but different sizes of one-dimensional nanochannels and interlayer spacing due to the different lengths and widths of the linkers. Because of the changes in interlayer spacing of these isostructural cationic frameworks, differences in the performance of Eu3+ ion exchange with [dma]+ are observed. Moreover, those compounds with high phase purity have been further characterized by thermogravimetric analysis, infrared spectroscopy, and luminescence spectroscopy, element analysis, PXRD and UV spectroscopy. Among them, compound 3 with strong fluorescence can selectively detect Fe3+ over several competing metal cations in aqueous solution. This work not only provides a feasible patterning method for effectively regulating the modular synthesis of functional coordination polymers but also enriches the library of uranyl-based coordination polymers with intriguing structures and functionality.

6.
Inorg Chem ; 61(7): 3058-3071, 2022 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-35130695

RESUMEN

The propensity of uranyl for hydrolysis in aqueous environments prevents precise control of uranyl species in the scenarios of on-demand separation and tailored synthesis. Herein, using cucurbit[7]uril (CB[7]) as the macrocyclic molecule and 4,4'-bipyridine-N,N'-dioxide (DPO) as the string molecule, we propose a new kind of multidentate pseudorotaxane ligand, DPO@CB[7] for capturing uranyl species at different pH's. With the aprotic nature of DPO for metal coordination, the coordination ability of the DPO@CB[7] ligand is less affected by pH and can work in a wide range of pH's. Furthermore, by adaptive uranyl coordination, this aprotic pseudorotaxane ligand achieves effective recognition for different uranyl species ranging from monomeric to tetrameric originating from hydrolysis at varying pH's, and four novel uranyl-rotaxane compounds (URC1-4) are successfully obtained. Single-crystal X-ray diffraction analysis reveals that the DPO@CB[7] ligand coordinates with uranyl centers from monomeric to tetrameric in four different modes, as a result of structural flexibility of the DPO@CB[7] pseudorotaxane ligand. A detailed discussion for conformation flexibility of the DPO@CB[7] ligand has been conducted on the position changes of the DPO ligand trapped in the CB[7], which thus reveals good adaptivity of DPO@CB[7] that is noncovalently bonded as a supramolecular motif. In addition, characterization of the physicochemical properties of URC1 and URC2 with high phase purity, including powder X-ray diffraction (PXRD), infrared spectroscopy (IR), thermogravimetric analysis (TGA), and luminescence properties, are also provided. This work provides a good case of an adaptive pseudorotaxane ligand for the recognition and capture of different uranyl species and will bring valuable hints to the design of multifunctional supramolecular ligands for actinide separation in the future.

7.
Inorg Chem ; 61(1): 302-316, 2022 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-34908402

RESUMEN

The electron-rich squarate ion (C4O42-, SA2-) possesses electronic delocalization over the entire molecule and good redox activity, and the functionalization of metal-organic complexes with the SA2- group is desirable. In this work, a mixed-ligand method is used to construct novel uranyl squarate coordination polymers utilizing 4,4'-bipyridine (bpy), 4,4'-bipyridine-N,N'-dioxide (bpydo), 1,10-phenanthroline (phen), 4,4'-vinylenedipyridine (vidpy), and in situ formed oxalate (OA2-) as ancillary ligands. Seven mixed-ligand uranyl compounds, [(UO2)(OH)(SA)](Hbpy) (1), [(UO2)(H2O)(SA)2](H2bpy) (2), (UO2)(H2O)(SA)(bpydo)·2H2O (3), (UO2)(H2O)(SA)(phen)·H2O (4), (UO2)(OH)(SA)0.5(phen)·H2O (5), [(UO2)(SA)(OA)0.5](Hphen) (6), and [(UO2)(SA)(OA)0.5](Hvidpy) (7), with varying crystal structures were synthesized under hydrothermal conditions. Compound 1, together with bpy molecules filling in the interlayer space as template agents, has a two-dimensional (2D) network structure, while 2 gives a one-dimensional (1D) chain based on mononuclear uranium units. Compound 3 shows a neutral 2D network through the combined linkage of SA2- and bpydo. Both 4 and 5 have a similar chain-like structure due to the capping effect of phen motifs, while phen molecules in 6 act as templating agents after protonation. Similar to 6, compound 7 has a "sandwich-like" structure in which the Hvidpy motifs locate in the voids of layers of 2D uranyl-squarate networks. The redox properties of typical mixed-ligand uranyl-squarate compounds, 1, 4, and 5 with high phase purity, are characterized using cyclic voltammetry. All three of these uranyl coordination compounds show anode peaks (Ea) at 0.777, 0.804, and 0.760 V, respectively, which correspond to the oxidation process of SA2- → SA. Meanwhile, cathodic peaks (Ec) at -0.328, -0.315, and -0.323 V corresponding to the reduction process of U(VI) → U(V) are also observed. The results reveal that all three of these uranyl coordination compounds show good redox activity and, most importantly, the interplay between two different redox-active motifs of SA2- organic linker and uranyl node. This work enriches the library of redox-active uranyl compounds and provides a feasible mixed-ligand method for regulating the synthesis of functional actinide compounds.

8.
Chemistry ; 27(34): 8730-8736, 2021 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-33872429

RESUMEN

We present here the synthesis of a novel fluorescent actinide polyrotaxane compound URCP1 through the utilization of an end-cutting pseudorotaxane precursor with only the cucurbit[6]uril (CB[6]) macrocyclic components acting as linking struts. The non-coordinating guest motif in the obtained polyrotaxane, with increased freedom and structural flexibility, can display intriguing temperature-triggered conformational variations inside the cavity of CB[6], which was clearly evidenced by crystallographic snapshots at different temperatures. Notably, this observation of temperature-triggered structural dynamics in URCP1 represents the first report of actinide polyrotaxane with such feature in solid-state. Moreover, URCP1 has a high photoluminescence quantum yield (PLQY) of 49.8 %, comparable to other luminescent uranyl compounds, and can work as a fluorescent probe to selectively detect Fe3+ over other eight competing cations in aqueous solution, with the limit of detection being as low as 4.4×10-3  ppm.

9.
Inorg Chem ; 60(14): 10522-10534, 2021 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-34212724

RESUMEN

In the present work, we proposed regulating uranyl coordination behavior of cucurbituril-bipyridinium pseudorotaxane ligand by utilizing meta-functionalized bipyridinium dicarboxylate guest. A tailored pseudorotaxane precursor involving 1,1'-(hexane-1,6-diyl)bis(3-cyanopyridin-1-ium) bromide (C6BPCN3) and cucurbit[6]uril (CB[6]) has designed and synthesized. Through in situ hydrolysis of the pseudorotaxane ligands and their coordination assembly with uranyl cations, seven new uranyl-rotaxane coordination polymers URCP1-URCP7 have been obtained under hydrothermal conditions in the presence of different anions. It is demonstrated that the variation of carboxylate groups from para- to meta-position greatly affected the coordination behaviors of the meta-functionalized pseudorotaxane linkers, which are enriched from simple guest-only binding to host-guest simultaneous coordination and synergistic chelating. This effective regulation on uranyl coordination of supramolecular pseudorotaxane can be attributed to the proximity effect, which refers to the meta-position carboxyl group being spatially closer to the portal carbonyl group of CB[6]. Moreover, by combining other regulation methods such as introducing competing counterions and modulating solution acidity, the nuclearity of the uranyl center and the coordination patterns of the pseudorotaxane ligand can be diversely tuned, which subsequently exert great influence on the final dimensionality of resultant uranyl compounds. This work presents a large diversity of uranyl-based coordination polyrotaxane compounds with fascinating mechanically interlocked components and, most importantly, provides a feasible approach to adjust and control the metal coordination behavior of the pseudorotaxane ligand that might expand the scope of application of such supramolecular ligands.

10.
Inorg Chem ; 60(12): 8519-8529, 2021 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-34096273

RESUMEN

Monitoring and quantification of the photoresponsive behavior of metal-organic frameworks that respond to a light stimulus are crucial to establish a clear structure-activity relationship related to light regulation. Herein, we report the first azobenzene-modified photoresponsive thorium-organic framework (Th-Azo-MOF) with the formula [Th6O4(OH)4(H2O)6L6] (H2L = (E)-2'-p-tolyldiazenyl-1,1':4',4'-terphenyl-4,4″-dicarboxylic acid), in which the utilization of a thorium cluster as a metal node leads to one of the largest pore sizes among all the azobenzene-containing metal-organic frameworks (MOFs). The phototriggered transformation of the trans isomer to the cis isomer is monitored and characterized quantitatively by comprehensive analyses of NMR and UV spectroscopy, which reveals that the maximum isomerization ratio of cisTh-Azo-MOF in the solid state is 19.7% after irradiation for 120 min, and this isomerization is reversible and can be repeated several times without apparent performance changes. Moreover, the isomerization-related difference in the adsorption of the Rhodamine B guest is also illustrated and a possible photoregulated mechanism is proposed. This work will shed light on new explorations for constructing functionalized actinide porous materials by the elegant combination of actinide nodes with tailored organic ligands and furthermore will provide a comprehensive understanding of photoisomerization processes in MOF solids and insight into the mechanism on photoregulated cargo adsorption and release by photoactive MOFs.

11.
Inorg Chem ; 60(13): 9745-9756, 2021 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-34115461

RESUMEN

Phenanthroline-diamide ligands have been reported in the selective separation of actinides over Eu(III); on the contrary, relevant basic coordination chemistry studies are still limited, and extraction under actual application conditions is rarely involved. In this work, N,N'-diethyl-N,N'-ditolyl-2,9-diamide-1,10-phenanthroline [Et-Tol-DAPhen (L)] was applied to explore the coordination performance of lanthanides in simulative high-level liquid waste. For the first time, cascade countercurrent extraction was conducted with Et-Tol-DAPhen as the extractant, which reveals the periodic tendency of the extraction efficiency of lanthanides to decrease gradually as the atomic number increases. Comparison of elements with similar radii verifies the hypothesis that the increase in the atomic number leads to a decrease in the ionic radius, thus reducing the coordination and extraction capacity of ligands. Slope analysis, electrospray ionization mass spectrometry, and ultraviolet-visible titration results show that the ligand forms 1:1 and 1:2 complexes with lanthanides and the coordination ability follows the tendency of extraction efficiency, and the first crystal structures of Lns(III) with a phenanthroline-diamide ligand, i.e., [LaL(NO3)3(H2O)] and [LaL2(NO3)2][(NO3)], were obtained, which confirms the conclusions described above. This work promises to enhance our comprehension of the chemical properties of Lns(III) and offer new clues for the design and synthesis of novel separation ligands.

12.
Inorg Chem ; 60(4): 2133-2137, 2021 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-33496591

RESUMEN

Because H2O2 is thermally unstable, it seems to be difficult to synthesize peroxides at elevated temperatures. We describe here the in situ generation of peroxide that is incorporated in a new uranyl peroxo complex, HT-UPO1, through the hydrothermal treatment of uranyl nitrate at 150 °C in the presence of organic ligands. In this novel process, a highly conjugated aromatic carboxylate linker, (E)-4-[2-(pyridin-4-yl)vinyl]benzoic acid (HPyVB), plays a crucial role by inducing the reduction of oxygen in air to form peroxide in situ and coordinating with uranyl to promote the preferred formation of thermally stable HT-UPO1. This work expands our knowledge on the speciation and chemistry of uranyl peroxide compounds and also sheds light on the possibility of their synthesis under more harsh conditions.

13.
Epilepsy Behav ; 114(Pt A): 107572, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33268015

RESUMEN

OBJECTIVE: The goal of this study was to evaluate the predictive capacity of four scoring tools: the Status Epilepticus Severity Score (STESS), the Encephalitis-NCSE-Diazepam resistance-Image abnormalities-Tracheal intubation (END-IT) score, and two variable combinations of the Epidemiology-based Mortality Score in Status Epilepticus (EMSE) in younger and older adult patients with status epilepticus (SE). METHODS: We present a retrospective hospital-based analysis with a focus on adult patients with SE at three tertiary care hospitals in the Zhejiang province of China. Data were collected from January 2013 to December 2018. The patients were divided into two groups: younger adult patients (18-64 years old) and older adult patients (≥65 years old). Clinical outcomes (dead or alive) were assessed at hospital discharge. The four scoring tools were used to predict in-hospital mortality in both younger and older adult patients. RESULTS: The mortality rate in older adult patients (25.4%) was higher than in younger adult patients (12.9%). Compared with the elderly, the younger adult patients had a higher proportion of encephalitis, while acute cerebrovascular disease and Charlson Complications Index (CCI) were lower. For the younger adult patients, END-IT had the largest area under the curve (AUC) of 0.843 (95% CI, 0.772-0.899), which was higher than the EMSE-EAL value of 0.687 (95% CI, 0.603-0.763, p < 0.05) and EMSE-EAC of 0.646 (95% CI, 0.561-0.725, p < 0.05). For the older adult patients, EMSE-EAL had the largest AUC of 0.843 (95% CI, 0.738-0.919), which was significantly higher than STESS with an AUC of 0.676 (95% CI, 0.554-0.782, p < 0.05). Moreover, the AUC of EMSE-EAL in the elderly was larger than in younger adult patients. The cutoffs in younger adult patients were STESS ≥ 4 (sensitivity 0.444, specificity 0.951), END-IT ≥ 3 (sensitivity 0.833, specificity 0.672), EMSE-EAL ≥ 31 (sensitivity 0.778, specificity 0.566), and EMSE-EAC ≥ 33 (sensitivity 0.833, specificity 0.492). However, the cutoffs in older adult patients were STESS ≥ 5 (sensitivity 0.500, specificity 0.925), END-IT ≥ 2 (sensitivity 0.944, specificity 0.547), EMSE-EAL ≥ 30 (sensitivity 0.944, specificity 0.623), and EMSE-EAC ≥ 31 (sensitivity 0.944, specificity 0.415). CONCLUSION: Our results indicated that the STESS, END-IT, EMSE-EAC, and EMSE-EAL scores have excellent capacity to predict in-hospital mortality in both younger and older adult patients with SE. Our study supports the use of END-IT in patients under 65 years of age and suggests that EMSE-EAL is the most suitable scoring tool for patients over 65.


Asunto(s)
Estado Epiléptico , Adolescente , Adulto , Anciano , China , Mortalidad Hospitalaria , Humanos , Persona de Mediana Edad , Pronóstico , Estudios Retrospectivos , Índice de Severidad de la Enfermedad , Estado Epiléptico/diagnóstico , Adulto Joven
14.
J Chem Phys ; 154(23): 234108, 2021 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-34241258

RESUMEN

In statistical mechanics, the formation free energy of an i-mer can be understood as the Gibbs free energy change in a system consisting of pure monomers after and prior to the formation of the i-mer. For molecules interacting via Lennard-Jones potential, we have computed the formation free energy of a Stillinger i-mer [F. H. Stillinger, J. Chem. Phys. 38, 1486 (1963)] and a ten Wolde-Frenkel (tWF) [P. R. ten Wolde and D. Frenkel, J. Chem. Phys. 109, 9901 (1998)] i-mer at spinodal at reduced temperatures from 0.7 to 1.2. It turns out that the size of a critical Stillinger i-mer remains finite and its formation free energy is on the order of kBT, and the size of a critical tWF i-mer remains finite and its formation free energy is even higher. This can be explained by Binder's theory [K. Binder, Phys. Rev. A 29, 341 (1984)] that for a system, when approaching spinodal, if the Ginzburg criterion is not satisfied, a gradual transition will take place from nucleation to spinodal decomposition, where the free-energy barrier height is on the order of kBT.

15.
J Am Chem Soc ; 142(39): 16538-16545, 2020 09 30.
Artículo en Inglés | MEDLINE | ID: mdl-32931700

RESUMEN

The separation of actinides has a vital place in nuclear fuel reprocessing, recovery of radionuclides, and remediation of environmental contamination. Here we propose a new paradigm of nanocluster-based actinide separation, namely, nanoextraction, that can achieve efficient sequestration of uranium in an unprecedented form of giant coordination nanocages using a cone-shaped macrocyclic pyrogallol[4]arene as the extractant. The U24-based hexameric pyrogallol[4]arene nanocages with distinctive [U2(PG)2] binuclear units (PG = pyrogallol) that rapidly assembled in situ in monophasic solvent were identified by single-crystal X-ray diffraction, MALDI-TOF mass spectrometry, NMR spectroscopy, and small-angle X-ray and neutron scattering. Comprehensive biphasic extraction studies showed that this novel separation strategy has enticing advantages such as fast kinetics, high efficiency, and good selectivity over lanthanides, thereby demonstrating its potential for efficient separation of actinide ions.

16.
Am J Pathol ; 189(5): 1065-1076, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30735628

RESUMEN

It has been reported that disorders of epigenetic modulation play a critical role in carcinogenesis. Methyl-CpG binding domain protein 2 (MBD2) is known to act as an epigenetic modulator in various types of tumors; however, the role of MBD2 in lung adenocarcinoma (LUAD) remains unclear. Herein, we demonstrated the down-regulation of MBD2 in LUAD compared with adjacent nontumor tissues. The down-regulation of MBD2 in LUAD was correlated with metastasis and poor survival. In addition, MBD2 inhibited tumor metastasis by maintaining the expression of the miR-200s, which suppressed the invasive properties of tumors. Also, MBD2 positively correlated with 5-hydroxymethylcytosine content in the promoter of miR-200s. The conventional view is that MBD2 acts as a transcriptional suppressor. However, the data revealed that MBD2 may act as a transcriptional activator by recruiting 10 to 11 translocation 1 (TET1) and forming a chromatin-remodeling complex. The MBD2-TET1 complex locates to the TET1 promoter and removes the methyl residues in this region, thereby activating TET1 transcription. TET1 also acted as a tumor suppressor in LUAD. Taken together, the data demonstrate the correlation between MBD2, miR-200s, and TET1, and tumor suppressive effect of MBD2 through up-regulation of TET1 and the miR-200s.


Asunto(s)
Adenocarcinoma del Pulmón/patología , Biomarcadores de Tumor/genética , Proteínas de Unión al ADN/metabolismo , Epigénesis Genética , Regulación Neoplásica de la Expresión Génica , MicroARNs/genética , Oxigenasas de Función Mixta/genética , Proteínas Proto-Oncogénicas/genética , Adenocarcinoma del Pulmón/genética , Adenocarcinoma del Pulmón/metabolismo , Apoptosis , Movimiento Celular , Proliferación Celular , Metilación de ADN , Proteínas de Unión al ADN/genética , Femenino , Estudios de Seguimiento , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , Masculino , Persona de Mediana Edad , Pronóstico , Regiones Promotoras Genéticas , Células Tumorales Cultivadas
18.
J Biochem Mol Toxicol ; 33(8): e22346, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31291034

RESUMEN

Non-small-cell lung cancer (NSCLC) is one of the most prevalent type of lung cancers with an increased mortality rate in both developed and developing countries worldwide. Dieckol is one such polyphenolic drug extracted from brown algae which has proven antioxidant and anti-inflammatory properties. In the present study, we evaluated the anticancer property of dieckol against NSCLC cell line A549. The LC50 value of dieckol was found to be 25 µg/mL by performing 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and the antiapoptotic property of dieckol was analyzed by dual staining technique with acridine orange/propidium iodide (AO/PI) stains. It was further confirmed with flow cytometry analysis with Annexin FITC and JC-1 staining and the anti-invasive property was assessed by Transwell assay. The molecular mechanism of dieckol anticancer activity was confirmed by estimating the levels of caspases and by estimating the signaling proteins of Pi3K/AKT/mTOR signaling pathway using the immunoblotting technique. Our data suggest that dieckol is potent anticancer agent, it effectively inhibits the invasive and migratory property A549 cells and it also induces apoptosis via inhibiting Pi3K/AKT/mTOR signaling, activating the tumor suppressor protein E-cadherin signifying that dieckol is potent natural anticancer drug to treat NSCLC.


Asunto(s)
Benzofuranos/farmacología , Carcinoma de Pulmón de Células no Pequeñas/patología , Proliferación Celular/efectos de los fármacos , Neoplasias Pulmonares/patología , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal/efectos de los fármacos , Apoptosis/efectos de los fármacos , Carcinoma de Pulmón de Células no Pequeñas/enzimología , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Humanos , Neoplasias Pulmonares/enzimología , Neoplasias Pulmonares/metabolismo
19.
J Chem Phys ; 151(13): 134111, 2019 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-31594354

RESUMEN

The Helmholtz free energy of a constrained supersaturated vapor with a cluster size distribution consisting of clusters of various sizes is modeled as a mixture of hard spheres of various sizes attracting each other. This model naturally takes into account monomer-monomer and monomer-cluster interactions, so it implicitly pertains to nonideal gases, unlike prior work. Based on this model, the expressions for the equilibrium concentration and the formation free energies of clusters in a metastable supersaturated vapor have been derived. These results indicate that the widely used formula, ni = n1exp(-ßΔGi), that computes the formation free energy of a cluster does not work at high supersaturations. As an example, the formation free energies of clusters with Stillinger's physical cluster definition in metastable, highly supersaturated vapors interacting via Lennard-Jones potential are studied using these expressions. Noticeable differences have been found for both the formation free energies of clusters and sizes of the critical clusters computed from our proposed expressions vs those from the formula ni = n1exp(-ßΔGi).

20.
Drug Dev Res ; 80(3): 294-309, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30864233

RESUMEN

This study was designed to delineate the effect of kaempferol (KF) on heart failure (HF) in diabetic rats. Streptozotocin-induced male diabetic rats received KF orally at 10 and 20 mg/kg for 42 consecutive days. In last 2 days of the experimental period, isoproterenol was subcutaneously injected at 85 mg/kg to induce HF. The hearts were processed for hemodynamic, biochemical, molecular, and histological investigations. Systolic blood pressure, diastolic blood pressure, and mean arterial blood pressure were elevated in KF-treated HF-induced diabetic rats. Moreover, KF treatment resulted in decreased fasting blood glucose and glycosylated hemoglobin levels with increased serum insulin levels. Besides, serum cardiac injury markers like troponin-I, creatine kinase-muscle/brain, lactate dehydrogenase, and brain natriuretic peptide levels were significantly reduced in KF treatment. KF treatment has shown decrease in cardiac heme oxygenase-1, nuclear factor erythroid 2-related factor 2 (Nrf-2), and γ-glutamylcysteine synthetase with increased Keap1 mRNA levels. The cardioprotection of KF was improved by inhibition of apoptosis via blocking phosphorylation of Akt/glycogen synthase kinase (GSK)-3ß and p38 mitogen-activated protein-kinase/extracellular signal-regulated kinases signaling pathways in HF-induced diabetic rats. Moreover, reduced cardiac apoptosis in KF treatment was confirmed by decreased terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) positive cells, histopathological changes in HF-induced diabetic rats. Therefore, the cardioprotective effect of KF is attributed to the regulation of Nrf2, nuclear factor kappa-light-chain-enhancer of activated B cells, and Akt/GSK-3ß signaling pathways in HF-induced diabetic rats.


Asunto(s)
Cardiotónicos/farmacología , Diabetes Mellitus Experimental/metabolismo , Insuficiencia Cardíaca/metabolismo , Quempferoles/farmacología , Infarto del Miocardio/metabolismo , Miocardio/metabolismo , Animales , Cardiotónicos/uso terapéutico , Diabetes Mellitus Experimental/tratamiento farmacológico , Glucógeno Sintasa Quinasa 3 beta/metabolismo , Corazón/efectos de los fármacos , Insuficiencia Cardíaca/inducido químicamente , Insuficiencia Cardíaca/tratamiento farmacológico , Isoproterenol , Quempferoles/uso terapéutico , Masculino , Infarto del Miocardio/tratamiento farmacológico , Factor 2 Relacionado con NF-E2/genética , Factor 2 Relacionado con NF-E2/metabolismo , FN-kappa B/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Ratas Wistar , Transducción de Señal/efectos de los fármacos
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