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1.
Chemphyschem ; 25(12): e202400105, 2024 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-38721760

RESUMEN

Pentazole is regarded as a unique inorganic molecule that possess organic heterocyclic structure. Therefore, the research on pentazolyl derivatives represents a cutting-edge direction in both contemporary inorganic chemistry and heterocyclic chemistry. Moreover, their synthesis is regarded as the most significant research topic in the field of energetic materials due to the great potential of pentazolyl derivatives to breakthrough the energy bottleneck of CHNO-based energetic materials. However, synthesizing pentazolyl derivatives is challenging. To provide a theoretical support for the synthesis, we conducted theoretical studies on six single-ring pentazolyl derivatives with different functional groups. The results suggest that derivatization reduces the bond strength and weakens the aromaticity of the pentazolate ring. Further analysis showed that derivatization mainly affects the π aromaticity of the pentazolate ring, and ultimately causing poor stability of the pentazolyl derivatives. Among the six derivatives investigated in this study, fluoro pentazole (cyclo-N5-F) and hydroxyl pentazole (cyclo-N5-OH) possess good aromaticity, which is similar to the reported cyclo-N5-NCHN(CH3)2. Further calculations show that the kinetic stability of cyclo-N5-OH is higher than that of cyclo-N5-F. These results collectively indicate that cyclo-N5-OH is a promising candidate for synthesizing single-ring pentazolyl derivatives.

2.
Inorg Chem ; 2024 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-38973778

RESUMEN

Pentazole (cyclo-HN5) is a unique heterocycle categorized as both an organic and inorganic compound. However, attempts to synthesize and characterize cyclo-HN5 have been unsuccessful thus far. In this study, we synthesized a cyclo-HN5 solution and investigated the spectra, structure, aromaticity, acidity, and stability of cyclo-HN5. The lone pair of electrons on the protonated N atom of cyclo-HN5 participates in π-electron delocalization, forming two N═N bonds. Further investigations suggest that cyclo-HN5 exhibits significantly decreased π aromaticity and slightly lower σ aromaticity than cyclo-N5-. Experimental results suggest that pure cyclo-HN5 is unstable at ambient temperatures and pressures, but it can be isolated at high pressures or stabilized in solution by abundant hydrogen bonds. The pKa of cyclo-HN5 was determined as 1.63 (H2O, 25 °C) via potentiometric titration, indicating that cyclo-HN5 is a medium-strong acid. This study reveals the fundamental structure and properties of cyclo-HN5, thereby providing important data for advancing cyclo-HN5 chemistry.

3.
Cereb Cortex ; 33(15): 9313-9324, 2023 07 24.
Artículo en Inglés | MEDLINE | ID: mdl-37310187

RESUMEN

Auditory steady-state response underlying gamma oscillations (gamma-ASSR) have been explored in patients with major depressive disorder (MDD), while ignoring the spatiotemporal dynamic characteristics. This study aims to construct dynamic directed brain networks to explore the disruption of spatiotemporal dynamics underlying gamma-ASSR in MDD. This study recruited 29 MDD patients and 30 healthy controls for a 40 Hz auditory steady-state evoked experiment. The propagation of gamma-ASSR was divided into early, middle, and late time interval. Partial directed coherence was applied to construct dynamic directed brain networks based on graph theory. The results showed that MDD patients had lower global efficiency and out-strength in temporal, parietal, and occipital regions over three time intervals. Additionally, distinct disrupted connectivity patterns occurred in different time intervals with abnormalities in the early and middle gamma-ASSR in left parietal regions cascading forward to produce dysfunction of frontal brain regions necessary to support gamma oscillations. Furthermore, the early and middle local efficiency of frontal regions were negatively correlated with symptom severity. These findings highlight patterns of hypofunction in the generation and maintenance of gamma-band oscillations across parietal-to-frontal regions in MDD patients, which provides novel insights into the neuropathological mechanism underlying gamma oscillations associated with aberrant brain network dynamics of MDD.


Asunto(s)
Trastorno Depresivo Mayor , Humanos , Encéfalo , Mapeo Encefálico , Lóbulo Parietal , Comunicación , Imagen por Resonancia Magnética/métodos
4.
Angew Chem Int Ed Engl ; 63(11): e202317355, 2024 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-38165698

RESUMEN

As the fourth full-nitrogen structure, the pentazolate anion (cyclo-N5 - ) was highly coveted for decades. In 2017, the first air-stable non-metal pentazolate salt, (N5 )6 (H3 O)3 (NH4 )4 Cl, was obtained, representing a milestone in this field. As the latest member of the azole family, cyclo-N5 - is comprised of five nitrogen atoms. Although significant attention has been paid to the potential of cyclo-N5 - as an energetic material, its poor thermostability hinders any practical application. However, the unique ring structure and multiple coordination capability of cyclo-N5 - provide a platform for the fabrication of various structures, among which pentasil-zeolite topologies are the most intriguing. In addition, the introduction of structure-directing auxiliaries enables the self-assembly of diverse topological architectures, potentially imparting cyclo-N5 - with the potential to impact wide-ranging areas of coordination chemistry and topology. In this minireview, different pentasil-zeolite topologies based on metal-pentazolate frameworks are evaluated. To date, three zeolitic and zeolite-like topologies have been reported, namely the melanophlogite (MEP), chibaite (MTN), and unj topologies. The MEP topology consists of two nanocages, Na20 N60 and Na24 N60 , whereas the MTN topology contains Na20 N60 and Na28 N80 nanocages. Furthermore, the unj topology features multiple homochiral channels consisting of two helical chains. Various possible strategies for obtaining additional pentasil-zeolite topologies are also discussed.

5.
Inorg Chem ; 62(42): 17199-17206, 2023 Oct 23.
Artículo en Inglés | MEDLINE | ID: mdl-37823764

RESUMEN

Energetic materials have been widely applied in civil and military fields, whose thermostability is a key indicator to evaluate their safety levels under severe conditions. Herein, two novel energetic metal-organic frameworks (EMOFs), namely, 4 and 6, were experimentally obtained and comprehensively characterized. The two EMOFs both possess unique three-dimensional (3D) coordination structures. With a high crystal density of 2.184 g·cm-3, EMOF 4 exhibits outstandingly superior thermostability (onset: 290 °C; peak: 303 °C), while EMOF 6 features onset and peak decomposition temperatures of 220 and 230 °C. The calculated energetic parameters of 4 and 6 are as follows: detonation velocity: 8731 m·s-1 and 8294 m·s-1; detonation pressure: 26.5 and 26.4 GPa. Compared to EMOF 6, EMOF 4 features high energy, excellent thermostability, and low mechanical sensitivities, which should be partly attributed to more plentiful coordination interactions. More coordination bonds are conducive to strengthening the EMOF framework, which needs much more energy to collapse, thereby maintaining higher thermal stability. The above favorable characteristics not only indicate EMOF 4 has a promising future in applications as a thermostable explosive but also provide an effective and feasible strategy for developing novel heat-resistant energetic materials via reinforced frame structures of EMOFs.

6.
Inorg Chem ; 60(12): 8409-8413, 2021 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-33871998

RESUMEN

Two novel sodium-pentazolate frameworks (namely, MPF-3 and MPF-4) were achieved by adding simple additives. MPF-3 exhibits an aesthetic three-dimensional (3D) framework with the zeolitic MTN topology, featuring Na28N80 and Na20N60 nanocages. In MPF-4, two left-handed helical chains construct enclosed homochiral channels filled with dimethyl sulfone molecules, which constitute a zeolite-like UNJ topology. Importantly, the preparation of these two compounds provides an effective experimental means to explore the unique symmetrical structure and multiple coordination modes of pentazolium anion and demonstrates that it is possible to regulate the crystal structure through appropriate additives.

7.
Appl Geogr ; 1322021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34121782

RESUMEN

Social scientists routinely rely on methods of interpolation to adjust available data to their research needs. Spatial data from different sources often are based on different geographies that need to be reconciled, and some boundaries (e.g., administrative or political boundaries) change frequently. This study calls attention to the potential for substantial error in efforts to harmonize data to constant boundaries using standard approaches to areal and population interpolation. The case in point is census tract boundaries in the United States, which are redefined before every decennial census. Research on neighborhood effects and neighborhood change rely heavily on estimates of local area characteristics for a consistent area of time, for which they now routinely use estimates based on interpolation offered by sources such as the Neighborhood Change Data Base (NCDB) and Longitudinal Tract Data Base (LTDB). We identify a fundamental problem with how these estimates are created, and we reveal an alarming level of error in estimates of population characteristics in 2000 within 2010 boundaries. We do this by comparing estimates from one of these sources (the LTDB) to true values calculated by re-aggregating original 2000 census microdata to 2010 tract areas. We then demonstrate an alternative approach that allows the re-aggregated values to be publicly disclosed, using "differential privacy" (DP) methods to inject random noise that meets Census Bureau standards for protecting confidentiality of the raw data. We show that the DP estimates are considerably more accurate than the LTDB estimates based on interpolation, and we examine conditions under which interpolation is more susceptible to error. This study reveals cause for greater caution in the use of interpolated estimates from any source. Until and unless DP estimates can be publicly disclosed for a wide range of variables and years, research on neighborhood change should routinely examine data for signs of estimation error that may be substantial in a large share of tracts that experienced complex boundary changes.

8.
Demography ; 57(5): 1951-1974, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32935300

RESUMEN

Reports of rising income segregation in the United States have been brought into question by the observation that post-2000 estimates are upwardly biased because of a reduction in the sample sizes on which they are based. Recent studies have offered estimates of this sample-count bias using public data. We show here that there are two substantial sources of systematic bias in estimating segregation levels: bias associated with sample size and bias associated with using weighted sample data. We rely on new correction methods using the original census sample data for individual households to provide more accurate estimates. Family income segregation rose markedly in the 1980s but only selectively after 1990. For some categories of families, segregation declined after 1990. There has been an upward trend for families with children but not specifically for families with children in the upper or lower 10% of the income distribution. Separate analyses by race/ethnicity show that income segregation was not generally higher among Blacks and Hispanics than among White families, and evidence of income segregation trends for these separate groups is mixed. Income segregation increased for all three racial groups for families with children, particularly for Hispanics (but not Whites or Blacks) in the upper 10% of the income distribution. Trends vary for specific combinations of race/ethnicity, presence of children, and location in the income distribution, offering new challenges for understanding the underlying processes of change.


Asunto(s)
Composición Familiar , Renta/estadística & datos numéricos , Grupos Raciales/estadística & datos numéricos , Segregación Social/tendencias , Sesgo , Humanos , Proyectos de Investigación , Estados Unidos
9.
Biochim Biophys Acta Mol Basis Dis ; 1864(2): 338-346, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29101051

RESUMEN

Hepatic insulin sensitivity is critical for glucose homeostasis, and insulin resistance is a fundamental syndrome found in various metabolic disorders, including obesity and type 2 diabetes. Despite considerable studies on the mechanisms of hepatic insulin resistance, the link between epigenetic regulation and the development of insulin resistance remains elusive. Here, we reported that G9a/EHMT2, a histone methyltransferase, was markedly decreased in the liver of db/db mice and high-fat diet (HFD)-fed mice. In cultured hepatic cells, G9a knockdown resulted in downregulation of insulin receptor, p-AKT and p-GSK3ß; while upon upregulation, G9a prevented the palmitic acid- or glucosamine-induced insulin resistance by preserving the normal level of insulin receptor and integrity of insulin signaling. Further mechanistic study suggested that G9a regulated the expression level of high mobility group AT-hook 1 (HMGA1), a key regulator responsible for the transcription of insulin receptor (INSR) gene. Overexpression of HMGA1 normalized the impaired insulin signaling in G9a knockdown hepatic cells. Importantly, in db/db mice, restoring the expression level of G9a not only upregulated HMGA1 level and improved the impaired hepatic insulin signaling, but also alleviated hyperglycemia and hyperinsulinemia. Together, our results revealed a novel role for G9a in modulating insulin signaling, at least in part, depending on its regulatory function on HMGA1.


Asunto(s)
Proteína HMGA1a/metabolismo , N-Metiltransferasa de Histona-Lisina/metabolismo , Resistencia a la Insulina , Insulina/metabolismo , Hígado/metabolismo , Animales , Glucemia/análisis , Dieta Alta en Grasa , Epigénesis Genética , Regulación de la Expresión Génica , Glucosamina/metabolismo , Glucógeno Sintasa Quinasa 3 beta/metabolismo , Células Hep G2 , Antígenos de Histocompatibilidad/genética , N-Metiltransferasa de Histona-Lisina/genética , Histonas/metabolismo , Humanos , Insulina/sangre , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ácido Palmítico/metabolismo , Fosforilación , Proteínas Proto-Oncogénicas c-akt/metabolismo , Receptor de Insulina/metabolismo , Receptores de Leptina/genética , Transducción de Señal
10.
Chemistry ; 24(18): 4620-4627, 2018 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-29369440

RESUMEN

A novel family of hydrophobic triaminocyclopropenium cation based ionic liquids have been synthesized, and their structures and physicochemical properties characterized by NMR and IR spectroscopy, elemental analysis, differential scanning calorimetry, and hypergolic tests. The experimental results showed that all of these ionic liquids exhibited the expected hypergolic reactivity with the oxidizer white fuming nitric acid. Among them, the hypergolic ionic liquid based on the cyanoimidazolylborohydride anion showed excellent integrated properties, including high decomposition temperature (194 °C), high density (0.95 g cm-3 ), moderate viscosity (44 MPa s), ultrafast ignition delay time (6 ms), and high specific impulse (301.9 s); this demonstrates its potential as an environmentally friendly alternative to toxic hydrazine derivatives.

11.
Angew Chem Int Ed Engl ; 57(10): 2592-2595, 2018 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-29336110

RESUMEN

The experimental detection and synthesis of pentazole (HN5 ) and its anion (cyclo-N5- ) have been actively pursued for the past hundred years. The synthesis of an aesthetic three-dimensional metal-pentazolate framework (denoted as MPF-1) is presented. It consists of sodium ions and cyclo-N5- anions in which the isolated cyclo-N5- anions are preternaturally stabilized in this inorganic open framework featuring two types of nanocages (Na20 N60 and Na24 N60 ) through strong metal coordination bonds. The compound MPF-1 is indefinitely stable at room temperature and exhibits high thermal stability relative to the reported cyclo-N5- salts. This finding offers a new approach to create metal-pentazolate frameworks (MPFs) and enables the future exploration of interesting pentazole chemistry and also related functional materials.

12.
Chemistry ; 23(51): 12502-12509, 2017 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-28580584

RESUMEN

Hypergolic ionic liquids (HILs) as potential replacements for hydrazine derivatives have attracted increasing interest over the last decade. Previous studies on HILs have mostly concentrated on the anionic innovations of ionic liquids to shorten the ignition delay (ID) time, but little attention has been paid to cationic modifications and their structure-property relationships. In this work, we present a new strategy of cationic functionalization by introducing the energetic nitrato group into the cationic units of HILs. Interestingly, the introduction of oxygen-rich nitrato groups into the cationic structure significantly improved the combustion performance of HILs with larger flame diameters and duration times. The density-specific impulse (ρIsp ) of these novel HILs are all above 279.0 s g cm-3 , much higher than that of UDMH (215.7 s g cm-3 ). In addition, the densities of these HILs are in the range of 1.22-1.39 g cm-3 , which is much higher than that of UDMH (0.79 g cm-3 ), showing their higher loading capacity than hydrazine-derived fuels in a propellant tank. This promising strategy of introducing nitrato groups into the cationic structures has provided a new platform for developing high-performing HILs with improved combustion properties.

13.
Cardiology ; 138(3): 169-178, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28746934

RESUMEN

OBJECTIVES: This study's aim was to evaluate the protective effects of salvianolate on contrast-induced nephropathy after primary percutaneous coronary intervention (PPCI) compared with normal saline (NS) hydration. METHODS: We enrolled patients with acute myocardial infarction who underwent PPCI in 3 centers in Shanghai. The patients were randomly assigned to the salvianolate group or the NS group. The incidence of CIN, the changes in renal function parameters, and the occurrence of adverse events after the procedure were compared between the 2 groups. We used a multivariate logistic regression analysis to determine the independent correlates of CIN after PPCI. RESULTS: A total of 484 patients were finally included in the statistical analysis. Compared with the control group, salvianolate reduced the incidence of CIN (9.1 vs. 16.3%, p = 0.018) after PPCI. The renal function parameters after PPCI in the salvianolate group were superior to those of the control group (p < 0.05). The composite adverse events rate was significantly lower in the salvianolate group within 1 month after the procedure (9.5 vs. 15.5%, p = 0.046). A higher peak of troponin I and loop diuretic therapy were the independent correlates of CIN after PPCI. CONCLUSIONS: Salvianolate reduces the incidence of CIN and protects renal function after PPCI, and the effects were superior to those of NS hydration.


Asunto(s)
Medios de Contraste/efectos adversos , Enfermedades Renales/epidemiología , Enfermedades Renales/prevención & control , Extractos Vegetales/uso terapéutico , Anciano , China/epidemiología , Angiografía Coronaria/efectos adversos , Electrocardiografía , Femenino , Humanos , Incidencia , Enfermedades Renales/inducido químicamente , Pruebas de Función Renal , Modelos Logísticos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Infarto del Miocardio/cirugía , Intervención Coronaria Percutánea/efectos adversos , Estudios Prospectivos , Análisis de Supervivencia
14.
Chemistry ; 22(29): 10187-93, 2016 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-27270594

RESUMEN

Currently, toxic and volatile hydrazine derivatives are still the main fuel choices for liquid bipropellants, especially in some traditional rocket propulsion systems. Therefore, the search for safer hypergolic fuels as replacements for hydrazine derivatives has been one of the most challenging tasks. In this study, six imidazolylidene-borane compounds with zwitterionic structure have been synthesized and characterized, and their hypergolic reactivity has been studied. As expected, these compounds exhibited fast spontaneous combustion upon contact with white fuming nitric acid (WFNA). Among them, compound 5 showed excellent integrated properties including wide liquid operating range (-70-160 °C), superior loading density (0.99 g cm(-3) ), ultrafast ignition delay times with WFNA (15 ms), and high specific impulse (303.5 s), suggesting promising application potential as safer hypergolic fuels in liquid bipropellant formulations.

15.
Demography ; 53(6): 1933-1953, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-27778294

RESUMEN

Neighborhoods where blacks and whites live in integrated settings alongside Hispanics and Asians represent a new phenomenon in the United States. These "global neighborhoods" have previously been identified in the nation's most diverse metropolitan centers. This study examines the full range of metropolitan areas to ask whether similar processes are occurring in other parts of the country. Is there evidence of stable racial integration in places that lack such diversity? What are the paths of neighborhood change in areas with few Hispanic or Asian residents, or areas where Hispanics are the principal minority group, or where there is no large minority presence at all? We distinguish four types of metropolitan regions: white, white/black, white/Hispanic/Asian, and multiethnic. These regions necessarily differ greatly in neighborhood composition, but some similar trajectories of neighborhood change are found in all of them. The results provide new evidence of the effect of Hispanic and Asian presence on black-white segregation in all parts of the country.


Asunto(s)
Diversidad Cultural , Etnicidad/estadística & datos numéricos , Grupos Raciales/estadística & datos numéricos , Características de la Residencia/estadística & datos numéricos , Población Urbana/estadística & datos numéricos , Negro o Afroamericano/estadística & datos numéricos , Asiático/estadística & datos numéricos , Hispánicos o Latinos/estadística & datos numéricos , Humanos , Dinámica Poblacional , Estados Unidos , Población Blanca/estadística & datos numéricos
16.
Zhongguo Zhong Yao Za Zhi ; 41(11): 2061-2069, 2016 Jun.
Artículo en Zh | MEDLINE | ID: mdl-28901102

RESUMEN

To evaluate the anti-acute inflammation effects of volatile oils from different processed products of Angelicae Sinensis Radix(AS) in the rat model of acute inflammation established by the metabolomic method. Volatile oil of charred AS (C-VOAS), wine-processed AS (J-VOAS), locally processed AS (T-VOAS) and oil-process AS (Y-VOAS) were applied to intervene the rat acute paw swelling inflammation model induced by Carrageenan. Changes in serum HIS, 5-HT, PGE2 and TNF-α content in rats were detected. Gas chromatography-mass spectrometry was used to detect the metabolites in plasma. Potential biomarkers were investigated according to principal component analysis method and partial least-squares discriminant analysis. According to the results, C-VOAS and J-VOAS could significantly inhibit inflammatory mediators Histamine, 5-hydroxytryptamine, prostaglandin-E2 and cytokine tumor necrosis factor-alpha (P<0.01), and T-VOAS and Y-VOAS also showed a significantly inhibitory effect (P<0.05). Compared with the normal group, 14 endogenous metabolite biomarkers showed metabolic disturbance in plasma (P<0.05 or P<0.01). Compared with acute inflammation model group, C-VOAS and J-VOAS could better recover the levels of the endogenous metabolites (P<0.05 or P<0.01) than T-VOAS and Y-VOAS (P<0.05 or P<0.01). This study suggests that C-VOAS and J-VOAS show a better anti-inflammatory effect than T-VOAS and Y-VOAS. Therefore, the metabolomic method could be used to expound the anti-inflammatory mechanism of volatile oils from different processed products of AS, and provide a theoretical basis for clinical application of VOAS.


Asunto(s)
Angelica sinensis/química , Antiinflamatorios/farmacología , Medicamentos Herbarios Chinos/farmacología , Aceites Volátiles/farmacología , Animales , Dinoprostona/sangre , Cromatografía de Gases y Espectrometría de Masas , Histamina/sangre , Metabolómica , Ratas , Serotonina/sangre , Factor de Necrosis Tumoral alfa/sangre
17.
Biomed Chromatogr ; 29(6): 902-10, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25515821

RESUMEN

Metabonomics based on GC-MS was used to study the possible anti-inflammatory mechanisms of volatile oils of Angelica sinensis (VOAS) in rats with acute inflammation. Acute inflammation was induced by subcutaneous injection of carrageenan in rats. The levels of prostaglandin E2 (PGE2 ), histamine (HIS) and 5-hydroxytryptamine (5-HT) in the inflammatory fluid were detected. Principal component analysis and orthogonal partial least squares-discriminant analysis models were performed for pattern recognition analysis. After the administration of VOAS, the levels of PGE2 , HIS, and 5-HT returned to levels observed in normal group. According to GC-MS analysis, the intervention of VOAS in rats with acute inflammation induced substantial and characteristic changes in their metabolic profiles. Fourteen metabolite biomarkers, namely, lactic acid, malic acid, citric acid, trans-dehydroandrosterone, aldosterone, linoleic acid, hexadecanoic acid, pregnenolone, octadecenoic acid, myristic acid, l-histidine, octadecanoic acid, arachidonic acid (AA) and l-tryptophan, were detected in the inflammatory fluid. The levels of all biomarkers either increased or decreased significantly in model groups. VOAS possibly intervened in the metabolic process of inflammation by altering histidine metabolism, tryptophan metabolism, AA metabolism, steroid hormone biosynthesis, fatty acid metabolism and energy metabolism. Metabonomics was used to reflect an organism's physiological and metabolic state comprehensively, and it is a potentially powerful tool that reveals the anti-acute-inflammatory mechanism of VOAS.


Asunto(s)
Angelica sinensis/química , Inflamación/metabolismo , Metaboloma/efectos de los fármacos , Aceites Volátiles/farmacología , Animales , Carragenina/efectos adversos , Modelos Animales de Enfermedad , Cromatografía de Gases y Espectrometría de Masas , Inflamación/inducido químicamente , Masculino , Redes y Vías Metabólicas/efectos de los fármacos , Metabolómica , Análisis Multivariante , Ratas , Ratas Wistar
18.
Clin Invest Med ; 37(6): E395-402, 2014 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-25618272

RESUMEN

PURPOSE: Drug-eluting stents (DES) in percutaneous coronary intervention are more effective in preventing in-stent restenosis compared with bare metal stents (BMS); however, DES may cause late stent thrombosis, which has limited its use. In this study, the functional properties of a newly developed DES (RAP/CS/HEP), in which rapamycin was abluminally-loaded onto a chitosan/heparin coating stent (CS/HEP), were investigated in large animal artery injury models. METHODS: The effectiveness of BMS, RAP (the traditional version of rapamycin DES), CS/HEP and RAP/CS/HEP stents in preventing coagulation and promoting re-endothelialisation was examined and compared in the porcine coronary artery models with arteriovenous shunt, high load thrombus and coronary balloon injury at day 7 and 28, respectively, after stent implantation. The re-endothelialisation on these stents was further evaluated in terms of endothelial gene expression using quantitative RT-PCR. RESULTS: In the porcine coronary artery injury models, both RAP and RAP/CS/HEP stents were potent in reducing neointimal thickness, thus enlarging lumen area efficiently in the stented artery region compared with BMS and CS/HEP. RAP/CS/HEP stents facilitated re-endothelialisation and inhibited thrombosis more efficiently than BMS and RAP. Consistent with this, the expression of endothelial genes, such as CD31, CD34, eNOS and VEGF, was significantly elevated with RAP/CS/HEP stents compared with RAP and BMS stents. CONCLUSION: Abluminal coating of rapamycin onto the endothelialisation-accelerated CS/HEP stent and may prove to be an efficient treatment for tackling the late stent thrombosis associated with the traditionally circumferential RAP stent. This new RAP/CS/HEP stent system exhibits considerably improved therapeutic activity.


Asunto(s)
Anticoagulantes/farmacología , Materiales Biocompatibles/farmacología , Quitosano/farmacología , Enfermedad de la Arteria Coronaria/terapia , Vasos Coronarios/lesiones , Stents Liberadores de Fármacos , Heparina/farmacología , Inmunosupresores/farmacología , Sirolimus/farmacología , Animales , Modelos Animales de Enfermedad , Porcinos
19.
Guang Pu Xue Yu Guang Pu Fen Xi ; 34(5): 1270-4, 2014 May.
Artículo en Zh | MEDLINE | ID: mdl-25095420

RESUMEN

A new rapid and nondestructive method for identifying polysaccharides from Angelica sinensis and its different processed products was developed, and this method was based on Fourier transform infrared spectroscopy (FTIR). In the clinic of traditional Chinese medicine, unprocessed Angelica sinensis(UAS) is of ten used after processed, the common processed products are Angelica sinensis parched with wine(WAS), Angelica sinensis parched with soil(SAS), Angelica sinensis parched with oil(OAS) and Charred Angelica sinensis(CAS). In order to use polysaccharides from Angelica sinensis and its processed products effectively and reasonably in clinic, it is very necessary to identify them. FTIR of polysaccharides from Angelica sinensis and its different processed products was determined, and then it was decomposed by discrete wavelet transform (DWT). The high frequency information in scale 2, 3 and 4 was selected as feature information, from which the each wavelet entropy was extracted as characteristic value. BP neural network was trained with these characteristic values. The trained BP neural network was used to identify polysaccharides from Angelica sinensis and its different processed products. According to 30 prediction samples, the correct rate for recognition was 93. 3%, which indicates that: it has better feasibility to identify polysaccharides from Angelica sinensis and its different processed products by this method, which is based on FTIR, discrete wavelet transform and BP neural network


Asunto(s)
Angelica sinensis/química , Polisacáridos/química , Espectroscopía Infrarroja por Transformada de Fourier , Medicamentos Herbarios Chinos/química
20.
Zhonghua Xin Xue Guan Bing Za Zhi ; 42(1): 48-52, 2014 Jan.
Artículo en Zh | MEDLINE | ID: mdl-24680270

RESUMEN

OBJECTIVE: This study investigated the effect of catheter-based renal sympathetic denervation (RDN) in pigs with rapid pacing induced heart failure. METHODS: Heart failure was induced by rapid right ventricular pacing in 12 pigs and pigs were randomly divided into RDN group (n = 6): pacing+RDN at 7 days post pacing; control group (n = 6): pacing only. Echocardiography examination (LVEF, LVEDD and LVESD) was performed before pacing and at 1 and 2 weeks post pacing. Serum biochemical markers including renin, aldosterone and creatinine were also measured at baseline, 1 and 2 weeks after pacing. Repeated renal artery angiography was performed at 1 week after RDN. All pigs were sacrificed to examine the heart and renal pathology and renal artery sympathetic nerve staining at 2 weeks post pacing. RESULTS: LVEF decreased 1 week after rapid pacing from (60.5 ± 6.0)% to (35.3 ± 9.8)%. LVEF was significantly higher [(42.8 ± 5.9) % vs. (33.4 ± 9.7)%, P = 0.001 8] while LVESD was significantly lower [(28.4 ± 3.7) mm vs. (33.0 ± 2.0) mm, P = 0.001 6] in the RDN group than in the control group at 2 weeks post pacing. At 2 weeks after pacing, plasma concentrations of renin and aldosterone were significantly lower in RDN group compared to the control group (all P < 0.05) . Kidney function and blood pressure were comparable between the two groups at 2 weeks post pacing. There were no signs of renal damages such as renal artery stenosis, dissection and thrombus in all pigs after 2 weeks pacing. Sympathetic neurons of adventitia were injured in RND group. CONCLUSION: RDN could significantly improve cardiac function and attenuate left ventricular remodeling via inhibiting renin-angiotensin-aldosterone system in this pacing induced pig heart failure model.


Asunto(s)
Ablación por Catéter/métodos , Insuficiencia Cardíaca/cirugía , Simpatectomía/métodos , Animales , Estimulación Cardíaca Artificial/efectos adversos , Modelos Animales de Enfermedad , Femenino , Insuficiencia Cardíaca/etiología , Riñón/inervación , Masculino , Porcinos
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