Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
Waste Manag ; 168: 396-405, 2023 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-37352689

RESUMEN

Waste cigarette filters mainly contain hardly degradable cellulose acetate, toxic nicotine, and traces of heavy metals, and therefore cause environmental pollution hazards when discarded. In order to convert cigarette butt waste into a valuable product, this article investigates the preparation of activated carbon from cigarette butts via a two-step process of hydrothermal reaction and a subsequent chemical activation with phosphoric acid as an activator. During hydrothermal reaction, it was found that a process of decarboxylation and dehydration cleavage of acetate occurs, leading to micron fragments and subsequent agglomeration into carbonaceous micro-spheres. The cigarette-butts-derived activated carbon micro-spheres have a high BET surface area of âˆ¼ 1406 m2/g and NH3 adsorption capacity of âˆ¼ 35.9 mg/g. It was revealed that the ammonia adsorption capacity tends to be positively and linearly correlated with the acidic functional group content of the activated carbon surface while negatively with BET surface area.


Asunto(s)
Carbón Orgánico , Productos de Tabaco , Amoníaco , Adsorción , Contaminación Ambiental
2.
J Clin Lab Anal ; 36(1): e24102, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34811812

RESUMEN

BACKGROUND: Mitochondrial dysfunctions caused by mitochondrial DNA (mtDNA) pathogenic mutations play putative roles in type 2 diabetes mellitus (T2DM) progression. But the underlying mechanism remains poorly understood. METHODS: A large Chinese family with maternally inherited diabetes and deafness (MIDD) underwent clinical, genetic, and molecular assessment. PCR and sequence analysis are carried out to detect mtDNA variants in affected family members, in addition, phylogenetic conservation analysis, haplogroup classification, and pathogenicity scoring system are performed. Moreover, the GJB2, GJB3, GJB6, and TRMU genes mutations are screened by PCR-Sanger sequencing. RESULTS: Six of 18 matrilineal subjects manifested different clinical phenotypes of diabetes. The average age at onset of diabetic patients is 52 years. Screening for the entire mitochondrial genomes suggests the co-existence of two possibly pathogenic mutations: tRNATrp A5514G and tRNASer(AGY) C12237T, which belongs to East Asia haplogroup G2a. By molecular level, m.A5514G mutation resides at acceptor stem of tRNATrp (position 3), which is critical for steady-state level of tRNATrp . Conversely, m.C12237T mutation occurs in the variable region of tRNASer(AGY) (position 31), which creates a novel base-pairing (11A-31T). Thus, the mitochondrial dysfunctions caused by tRNATrp A5514G and tRNASer(AGY) C12237T mutations, may be associated with T2DM in this pedigree. But we do not find any functional mutations in those nuclear genes. CONCLUSION: Our findings suggest that m.A5514G and m.C12337T mutations are associated with T2DM, screening for mt-tRNA mutations is useful for molecular diagnosis and prevention of mitochondrial diabetes.


Asunto(s)
ADN Mitocondrial/genética , Sordera/genética , Diabetes Mellitus Tipo 2/genética , Enfermedades Mitocondriales/genética , Mutación/genética , ARN de Transferencia/genética , Adulto , Animales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Linaje
3.
J Cancer Res Ther ; 14(7): 1665-1669, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30589057

RESUMEN

Poland's syndrome is a rare congenital malformation that is characterized by a congenital defect of the pectoralis major. It is associated with various ipsilateral upper extremity anomalies and homolateral breast hypoplasia. There have been reports of Poland's syndrome being associated with different malignancies. Here, we report two cases of Poland's syndrome associated with breast cancer (BC) and review the literature. To date, 21 cases (including our two cases) of Poland's syndrome associated with BC have been reported. The clinical characteristics of the disease are analyzed in this report.


Asunto(s)
Neoplasias de la Mama/complicaciones , Neoplasias de la Mama/diagnóstico , Síndrome de Poland/complicaciones , Síndrome de Poland/diagnóstico , Anciano , Biopsia , Neoplasias de la Mama/cirugía , Femenino , Humanos , Persona de Mediana Edad , Imagen Multimodal , Radiografía Torácica , Tomografía Computarizada por Rayos X , Ultrasonografía
4.
IUBMB Life ; 70(3): 237-245, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29405562

RESUMEN

Transforming growth factor-ß (TGF-ß), interleukin-10 (IL-10), and forkhead box P3 (Foxp3) have important roles in breast cancer development. Previous studies confirmed a correlation between these immune molecules and tumor characteristics, but their association with nutritional status in breast cancer is largely unknown. We aimed to investigate the association between body mass index (BMI), hemoglobin, total protein, albumin, globulin (GLB), albumin/GLB ratio (AGR), pre-albumin, prognostic nutritional index, and TGF-ß, IL-10, and Foxp3 mRNA expression in patients with breast cancer. Quantitative real-time PCR was used to detect the mRNA expression of TGF-ß, IL-10, and Foxp3 in the peripheral blood of 107 patients with breast cancer and 21 healthy controls. We found that TGF-ß mRNA levels were 2.6-fold, 3.2-fold, and 2.3-fold higher in patients with low BMI (<23), low AGR, and high GLB, respectively, than in their counterparts (P < 0.05). In addition, IL-10 mRNA expression levels in patients with normal BMI (<23) were 2.8-fold and 3.5-fold higher than in those who were overweight (23≤ BMI <25) and obese (BMI ≥ 25), respectively (P < 0.05). In addition, TGF-ß, IL-10, and Foxp3 mRNA levels were significantly higher in patients with breast cancer than in healthy controls (P < 0.05). In summary, our results suggest that nutritional status, especially BMI, may strongly affect systematic immune function in patients with breast cancer. © 2018 IUBMB Life, 70(3):237-245, 2018.


Asunto(s)
Neoplasias de la Mama/sangre , Factores de Transcripción Forkhead/sangre , Interleucina-10/sangre , Factor de Crecimiento Transformador beta/sangre , Adulto , Índice de Masa Corporal , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Persona de Mediana Edad , Obesidad/sangre , Obesidad/complicaciones , Obesidad/patología , ARN Mensajero/sangre
5.
J BUON ; 22(3): 741-745, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28730784

RESUMEN

PURPOSE: We conducted this study to retrospectively analyze the clinical effects of surgical resection for patients with myasthenia gravis (MG) complicated with thymoma. METHODS: 162 patients with myasthenia gravis complicated with thymoma, that were admitted to our hospital and underwent surgical disease resection from Nov. 1993 to Nov. 2015, were selected for this study. Analyzed were the pathology (2004 WHO), Masaoka clinical stage, myasthenia gravis types (Osserman types), myasthenic crisis during the perioperative period, and the relationship between recurrence and survival rates during follow-up visits. Operational methods included thymusectomy by sternal incision or video-assisted thoracoscopic thymusectomy. RESULTS: There were significant differences regarding distribution of clinical stages among different types of pathology. The operation time, efficacy rate, 5 and 10-year survival rates and complication rates during the perioperative period of video-assisted thoracoscopy were compared to those of the conventional surgery group. Among these groups, hemorrhage during operation, postoperative drainage and recurrence rate were significantly lower in the thoracoscopy group than in those of the conventional surgery group (p<0.05). CONCLUSION: The pathology type and clinical stages of thymoma complicating myasthenia gravis are related to the types of myasthenia gravis and the myasthenic crisis during perioperative period. Therefore, our results indicate that the thoracoscope treatment is safe and effective.


Asunto(s)
Miastenia Gravis/etiología , Timoma/complicaciones , Neoplasias del Timo/complicaciones , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Estudios Retrospectivos , Timoma/mortalidad , Timoma/patología , Timoma/cirugía , Neoplasias del Timo/mortalidad , Neoplasias del Timo/patología , Neoplasias del Timo/cirugía , Adulto Joven
6.
Adv Mater ; 29(13)2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28185334

RESUMEN

To dramatically stabilize the nanostructure of Sn and achieve ultrahigh reversibility of conversion reactions in lithiated SnO2 , a series of SnO2 -transition metal-graphite ternary nanocomposites are produced by ball milling, demonstrating high initial Coulombic efficiencies up to 88.6%, high reversible capacity (>700 mAh g-1 at 2 A g-1 ), and ultralong cycling life (90.3% of capacity retention after 1300 cycles).

7.
J Am Chem Soc ; 130(39): 13023-32, 2008 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-18767839

RESUMEN

A large class of cation-responsive fluorescent sensors utilizes a donor-spacer-acceptor (D-A) molecular framework that can modulate the fluorescence emission intensity through a fast photoinduced intramolecular electron transfer (PET) process. The emission enhancement upon binding of the analyte defines the contrast ratio of the probe, a key property that is particularly relevant in fluorescence microscopy imaging applications. Due to their unusual electronic structure, 1,3,5-triarylpyrazoline fluorophores allow for the differential tuning of the excited-state energy DeltaE(00) and the fluorophore acceptor potential E(A/A(-)), both of which are critical parameters that define the electron transfer (ET) thermodynamics and thus the contrast ratio. By systematically varying the number and attachment positions of fluoro substituents on the fluorophore pi-system, DeltaE(00) can be adjusted over a broad range (0.4 eV) without significantly altering the acceptor potential E(A/A(-)). Experimentally measured D-A coupling and reorganization energies were used to draw a potential map for identifying the optimal ET driving force that is expected to give a maximum fluorescence enhancement for a given change in donor potential upon binding of the analyte. The rational design strategy was tested by optimizing the fluorescence response of a pH-sensitive probe, thus yielding a maximum emission enhancement factor of 400 upon acidification. Furthermore, quantum chemical calculations were used to reproduce the experimental trends of reduction potentials, excited-state energies, and ET driving forces within the framework of linear free energy relationships (LFERs). Such LFERs should be suitable to semiempirically predict ET driving forces with an average unsigned error of 0.03 eV, consequently allowing for the computational prescreening of substituent combinations to best match the donor potential of a given cation receptor. Within the scaffold of the triarylpyrazoline platform, the outlined differential tuning of the electron transfer parameters should be applicable to a broad range of cation receptors for designing PET sensors with maximized contrast ratios.


Asunto(s)
Derivados del Benceno/química , Colorantes Fluorescentes/química , Pirazoles/química , Derivados del Benceno/síntesis química , Electroquímica , Colorantes Fluorescentes/síntesis química , Cinética , Transferencia Lineal de Energía , Oxidación-Reducción , Teoría Cuántica , Espectrometría de Fluorescencia , Relación Estructura-Actividad , Termodinámica
8.
Tetrahedron Lett ; 49(16): 2510-2513, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-19568325

RESUMEN

Aqueous Diels-Alder chemistry combined with a poly(ethylene glycol) (PEG) spacer was used to immobilize a diverse group of biomolecules onto a solid surface. Briefly, α, ω linear PEG conjugates were synthesized containing cyclopentadiene in the α position and either biotin, lactose, or protein A in the ω position. Linkers were coupled to N-maleimide (EMC)-functionalized glass substrates, and surface immobilization of biomolecules was confirmed by confocal fluorescence imaging.

9.
Proc Natl Acad Sci U S A ; 102(32): 11179-84, 2005 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-16061820

RESUMEN

Copper is an essential micronutrient that plays a central role for a broad range of biological processes. Although there is compelling evidence that the intracellular milieu does not contain any free copper ions, the rapid kinetics of copper uptake and release suggests the presence of a labile intracellular copper pool. To elucidate the subcellular localization of this pool, we have synthesized and characterized a membrane-permeable, copper-selective fluorescent sensor (CTAP-1). Upon addition of Cu(I), the sensor exhibits a 4.6-fold emission enhancement and reaches a quantum yield of 14%. The sensor exhibits excellent selectivity toward Cu(I), and its emission response is not compromised by the presence of millimolar concentrations of Ca(II) or Mg(II) ions. Variable temperature dynamic NMR studies revealed a rapid Cu(I) self-exchange equilibrium with a low activation barrier of deltaG++ = 44 kJ.mol(-1) and k(obs) approximately 10(5) s(-1) at room temperature. Mouse fibroblast cells (3T3) incubated with the sensor produced a copper-dependent perinuclear staining pattern, which colocalizes with the subcellular locations of mitochondria and the Golgi apparatus. To evaluate and confirm the sensor's copper-selectivity, we determined the subcellular topography of copper by synchrotron-based x-ray fluorescence microscopy. Furthermore, microprobe x-ray absorption measurements at various subcellular locations showed a near-edge feature that is characteristic for low-coordinate monovalent copper but does not resemble the published spectra for metallothionein or glutathione. The presented data provide a coherent picture with strong evidence for a kinetically labile copper pool, which is predominantly localized in the mitochondria and the Golgi apparatus.


Asunto(s)
Cobre/química , Modelos Químicos , Animales , Cobre/farmacocinética , Colorantes Fluorescentes , Aparato de Golgi/metabolismo , Espectroscopía de Resonancia Magnética/métodos , Ratones , Microscopía Fluorescente/métodos , Mitocondrias/metabolismo , Células 3T3 NIH , Sincrotrones , Rayos X
10.
J Environ Sci (China) ; 15(4): 514-9, 2003 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-12974314

RESUMEN

The environmental effect of degraded ecosystem's vegetation restoration in low subtropical China was studied. Results indicated that the vegetation recovery on degraded lands significantly ameliorates surrounding environment, increases species diversity, improves soil structure, raises soil fertility, enhances productivity, and promotes regional agricultural production and social economic development dramatically. Through the combining engineering and biological measures, the restoration of degraded ecosystem in low subtropical area is possible and economical. The restoration experience in Xiaoliang, Wuhua and other sites are valuable for other degraded subtropical area was introduced.


Asunto(s)
Conservación de los Recursos Naturales , Ecosistema , Contaminación Ambiental/prevención & control , China , Desarrollo de la Planta , Dinámica Poblacional , Suelo , Clima Tropical
11.
J Am Chem Soc ; 125(13): 3799-812, 2003 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-12656613

RESUMEN

A series of donor-substituted 1,3,5-triaryl-2-pyrazoline fluorophores were structurally characterized by X-ray analysis, and their photophysical properties studied by steady-state absorption and emission spectroscopy. The photoinduced electron-transfer thermodynamics of the derivatives was estimated on the basis of the spectroscopic data and redox potentials of the fluorophores. The aryl substituents in the 1- and 3-position of the pyrazoline ring influence the photophysical properties of the fluorophores in distinctly different ways. The excited-state equilibrium energy DeltaE(00) is primarily influenced by changes of the substituent in the 1-position, whereas the reduction potential of the fluorophore is essentially determined by the 3-aryl group. Density functional calculations were used to probe the electronic structure and energy ordering of the emissive and the electron-transfer state. The results from the computational analysis agree qualitatively well with the experimental data. In addition, we have evaluated a water soluble pyrazoline derivative in vivo as a potential intracellular pH probe. Membrane permeability, low toxicity, and high quantum yield render the fluorophore attractive for biological applications.


Asunto(s)
Colorantes Fluorescentes/química , Pirazoles/química , Permeabilidad de la Membrana Celular , Cristalografía por Rayos X , Electrones , Colorantes Fluorescentes/farmacocinética , Células HeLa , Humanos , Liposomas/química , Modelos Moleculares , Estructura Molecular , Oxidación-Reducción , Fotoquímica , Potenciometría , Pirazoles/farmacocinética , Teoría Cuántica , Espectrometría de Fluorescencia , Espectrofotometría Ultravioleta , Coloración y Etiquetado , Termodinámica
12.
Huan Jing Ke Xue ; 24(5): 39-43, 2003 Sep.
Artículo en Chino | MEDLINE | ID: mdl-14719258

RESUMEN

A new internally circulating fluidized bed for FGD process was developed, and different types of top and bottom structures were employed in the experiment to find out the best fluidized bed structure. Fluidizing status, the axial distribution of solid hold-up and the fluid mechanics under cold conditions were investigated. The results indicate that the unit can realize internally circulating of a large number of solid particles which presents an core-annulus structure when the velocity of fluidizing gas was at the range of 2.5 to 5 m/s, and that the solid density in the bed is higher than that in traditional equal diameter fluidized bed, which provide the equipment with potential for application in FGD process.


Asunto(s)
Reactores Biológicos , Compuestos de Calcio/química , Dióxido de Azufre/aislamiento & purificación , Dióxido de Azufre/química
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...