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1.
Ann Gastroenterol ; 37(1): 104-108, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38223242

RESUMEN

Background: Malignant etiologies are found in 70-80% of symptomatic retroperitoneal masses. Histology is required for diagnosis and treatment. Information about endoscopic ultrasound (EUS)-guided tissue acquisition (EUS-GTA) is scant for retroperitoneal masses. This study aimed to assess the pathology results of EUS-GTA for diagnosing retroperitoneal masses. Methods: This retrospective, multicenter study involved patients from 5 care centers. All patients with retroperitoneal masses who underwent EUS evaluation were enrolled. We recorded demographic and clinical characteristics, location and size of the mass, type of needle (FNA/FNB), and complications related to the procedure. Results: A total of 43 patients were included. The median age was 50.5 (range: 23-83) years, and 22 (51.2%) were female. The initial symptom was abdominal pain in 23 (52.3%) cases and weight loss in 11 (25%). Initial imaging was by computed tomography in 33 (75%) patients. Diagnosis with EUS-GTA was reached in 67.5% (29/43) cases. The most frequent histological diagnosis was carcinoma, in 25.5% (11/43). A malignant etiology was found in 31 (72%): 20 were primary tumors from the retroperitoneum, and 11 were metastases. In patients with metastasis, surgery was avoided and medical treatment was indicated. No adverse events were reported. Conclusion: EUS and EUS-GTA can frequently provide accurate tissue diagnosis and significantly impact the subsequent management.

2.
Med Biol Eng Comput ; 62(1): 225-236, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37770813

RESUMEN

Biological and environmental factors produce biochemical processes that modify the bone structure. A few studies have attempted to show the adverse biological effects of sun radiation. The bone tissue exposures to infrared and sunlight radiation are analyzed by using focused sound, characterization spectroscopy techniques, and image processing. The study is complemented with a finite element method simulation on temperature behaviors. The crystal morphology on the bone hydroxyapatite and functional groups was characterized by X-ray diffraction and infrared spectroscopy. The infrared spectra confirmed the hydroxyl group of bovine hydroxyapatite, amines, and lipids are also correlated with modifications of the hydroxyapatite. The diffractograms showed the characteristic peaks of hydroxyapatite, with the main intensity at 2θ = 32.02°. Bone samples exposed to sun radiation presented a peak at 2θ = 27.5°, evidencing the possible formation of ß-TCP y α-TCP. The analysis with the spectroscopy techniques about the structural changes in the samples suggests interpreting an increase of sound obtained by expanding the exposure time. It is possible to verify that there are some structural changes in the bone samples due to exposure to non-ionizing radiation. These results show an increase in the registered intensity sound correlated with the interpretation of the structural changes of bone. Thanks to the different novel analysis techniques established in the present study, it could establish the changes that experienced the bone structure under different sources of radiation, which will help to better detect scenarios of bone deficiency.


Asunto(s)
Huesos , Durapatita , Animales , Bovinos , Temperatura , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Durapatita/química , Luz Solar
3.
Environ Res ; 228: 115860, 2023 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-37030405

RESUMEN

The immobilization of TiO2-SiO2 (TSO) materials on seed mats stands as a practical way to help the germination and early growth of tomato plants (Solanum Lycopersicum). Mesoporous materials are functionalized with triethanolamine (TEA) and loaded with the biocide molecule of carvacrol (CAR). The effect of CAR on the parameters of germination percentage, germination time, root, shoot length, and chlorophyll content of seeds and/or tomato seedlings are investigated. The germination experiments were carried out using seed mats coated with the TSO materials, also TSO powdered materials were put directly on the tomato seeds to study their effect on germination. Direct deposition of TSO composites achieved the complete germination and longer shoots due to the cooperative interactions among nanomaterials, carvacrol, and the tomato seed. However, the handling of the seeds and the detrimental effect of powder in the germination system made difficult the application with agricultural purposes. The plastic seed mats provide a practical system with lower germination, but more homogenous growth of root/shoot is possible. Surprisingly, in this methodology the carvacrol presents a detrimental effect on germination due to less interaction with the seeds. The handling of seeds and recover of the nanomaterials and its reuse are advantages of the plastic seed mats, which together with less wastage of seeds suggest a potential use in agriculture. The as-synthetized TSO NPs, together with the functionalization of triethanolamine and carvacrol used to promote the health germination of the seeds, allows the control of the time for seed germination, germination %, and length for the root/shoot of seed tomato germination. The immobilization of mesoporous materials results in an alternative to help the germination and early growth of agricultural plants searching to avoid the lixiviation of nanomaterials to the environment.


Asunto(s)
Germinación , Solanum lycopersicum , Dióxido de Silicio , Semillas
4.
Environ Sci Pollut Res Int ; 30(20): 58156-58168, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36973629

RESUMEN

This research studied the performance of tin titanate (SnTiO3, SnT) and cellulose-based composites for the removal of clonazepam (CZP) drug by physical adsorption. The cellulose was extracted from a plant named tithonia tubaeformis, which is considered as weed in the crop fields of Mexico. The analysis by microscopy revealed that the SnTiO3 powders are formed by a mixture of coalesced grains and nanotubes with lengths in the range of 97-633 nm. Furthermore, the X-ray diffraction analysis indicated that the SnT powders present a mixture of cassiterite and rutile phases. Experiments for the CZP removal from drinking water were carried out, and several parameters such as initial drug concentration (1-10 mg/L), amount of SnT adsorbent per liter of contaminated solution (10-50 mg/L), and pH (3-10) were varied in order to study their influence on the CZP removal percentage. Essentially, we found that the SnT dosage of 50 mg/L produced the most efficient and fastest CZP removal, since 94.3% of CZP was removed after only 10 min of reaction. Moreover, a piece of cellulose (Cell) was decorated with 50 mg of SnT powder to form the Cell+SnT composite, and this was able to remove a maximum of 80.5% of CZP after 180 min of reaction. If the amount of SnT powder deposited on the Cell+SnT composite is raised up to 100 mg, the composite can remove 95.5% of CZP. The adsorption capacity was also calculated for the SnT powders and Cell+SnT composite and found that it was 6.3 times higher for the SnT powders. Furthermore, the Raman spectra recorded for the Cell+SnT composites demonstrated the presence of surface defects, which acted as adsorption centers for the CZP molecules. The results of this investigation demonstrate that eco-friendly and low-cost floatable composites can be used for the removal of pharmaceutical contaminants, which is an advantage over adsorbent powders.


Asunto(s)
Agua Potable , Nanopartículas , Contaminantes Químicos del Agua , Agua Potable/análisis , Polvos , Clonazepam/análisis , Estaño/análisis , Adsorción , Contaminantes Químicos del Agua/análisis , Celulosa/química , Cinética , Concentración de Iones de Hidrógeno
5.
Environ Sci Pollut Res Int ; 30(2): 5258-5266, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-35980526

RESUMEN

This work reports on the structural, morphological, and photocatalytic properties of titanium dioxide (TiO2) and TiO2:NiIn (T-NiIn) coatings fabricated by spin coating. The SEM images revealed coatings with average thicknesses of 3.59 and 3.37 µm for the TiO2 and T-NiIn, respectively. EDS spectra and Raman studies confirmed the presence of TiO2 co-doped with nickel (Ni) and indium (In) in the coatings. XRD analysis showed the anatase and rutile phases for the TiO2 coatings, while the T-NiIn coatings presented the rutile and brookite phases. These samples were evaluated in the photocatalytic degradation of the eosin-yellowish (EY) dye. The T-NiIn coatings showed 9.1% higher effectiveness than the undoped TiO2 coatings after 300 min under UV irradiation. Meanwhile, the T-NiIn coatings exposed to solar light removed 40% more dye than the TiO2 coatings. Furthermore, T-NiIn coating was the most stable because its effectiveness was reduced by only 1.4% after 4 cycles of reuse. Additionally, the scavenger tests confirmed that the main oxidizing sites were the •OH- radicals and the superoxides •O2-. Thus, the use of coatings based on TiO2 co-doped with Ni and In is a feasible strategy to increase the degradation of the EY dye in drinking water.


Asunto(s)
Agua Potable , Eosina Amarillenta-(YS) , Níquel , Indio , Catálisis , Titanio/química
6.
J Environ Sci (China) ; 126: 575-589, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36503783

RESUMEN

We present the structural, morphological and photocatalytic properties of stretchable composites made with carbon nanotubes (CNTs), silicon rubber and Ni@TiO2:W nanoparticles (TiWNi NPs) with average size of 37 ± 2 nm. Microscopy images showed that the TiWNi NPs decorated the surface of the CNT fibers, which are oriented in a preferential direction. TiWNi NPs presented a mixture of anatase/rutile phases with cubic structure. The performance of the TiWNi powders and stretchable composites was evaluated for the photocatalytic degradation of diclofenac (DCF) anti-inflammatory drug under ultraviolet-visible light. The results revealed that the maximum DCF degradation percentages were 34.6%, 91.9%, 97.1%, 98.5% and 100% for the CNT composite (stretched at 0%), TiWNi powders, CNT + TiWNi (stretched at 0%), CNT + TiWNi (stretched at 50%) and CNT + TiWNi (stretched at 100%), respectively. Thus, stretching the CNT + TiWNi composites was a good strategy to enhance the DCF degradation percentage from 97.1% to 100%, since stretching created additional defects (oxygen vacancies) that acted as electron sink, delaying the electron-hole recombination, and favors the DCF degradation. Raman/absorbance measurements confirmed the presence of such defects. Moreover, the reactive oxygen species (ROS) were determined by the scavenger's experiments and found that the main ROS were the ·OH and O2- radicals, which attacked the DCF molecules, causing their degradation. The results of this investigation confirmed that the stretchable CNT/TiWNi-based composites are a viable alternative to remove pharmaceutical contaminants from water and can be manually separated from the decontaminated water, which is unviable using photocatalytic powders.


Asunto(s)
Agua Potable , Nanotubos de Carbono , Diclofenaco , Electrones , Oxígeno
7.
Environ Sci Pollut Res Int ; 29(51): 76752-76765, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35670940

RESUMEN

In this research, W-doped sodium nanotube titanate (NaTNT) nanoparticles were used for the photocatalytic degradation of the bromophenol blue (BPB) dye. The NaTNT powder was mixed with car's tire powder (TP) to enhance its light absorption or was supported on recycled car's air filters (AFs) to facilitate its removal from the cleaned water after the degradation of the BPB. The SEM analysis indicated that the NaTNT nanoparticles and the TP had sizes in the range of 150-325 nm and 8-37 µm, respectively. Both powders were also studied by X-ray diffraction and found that the sodium titanate corresponds to the Na2Ti6O13 with monoclinic phase, while the TP is formed by rubber, silicon, ZnS, and ZnO. The photocatalytic activity of the NaTNT powder was evaluated for the degradation of BPB dye (20 ppm) and obtained a maximum degradation of 95 and 80% under UV-Vis and natural solar light, respectively, after 4 h of irradiation. For the NaTNT + TP composite mixture, the maximum degradation was 87 and 68% under UV-Vis and solar light, respectively. The NaTNT and NaTNT + TP powders were supported on the AFs to form the AF + NaTNT and AF + NaTNT + TP composites. Those ones produced maximum degradation of 86% and 74% (under UV-Vis light), respectively. Besides, several initial pHs were tested for the contaminated water and determined that the maximum degradation of BPB (93-95%) is reached for the pHs of 3 and 7. Reuse experiments (3 cycles) revealed that the diminution of the BPB degradation percentage was 23% and 20% for the NaTNT and NaTNT + TP powders, respectively. Overall, it was demonstrated that the wasted car's air filters can be used as a support for photocatalytic powders, and this combination of AF + powder degrades the BPB with high efficiency.


Asunto(s)
Azul de Bromofenol , Óxido de Zinc , Polvos , Catálisis , Automóviles , Silicio , Goma , Agua , Sodio
8.
Environ Sci Pollut Res Int ; 29(39): 59915-59929, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35397726

RESUMEN

This research reports the use of biodegradable and flexible composites for the removal of the 2,6-dichlorobenzamide (BAM) pesticide from drinking water. Rice paper (a biodegradable substrate) and Ag/BaMoO4 (MOBA) nanoparticles were employed to fabricate these composites. The SEM images showed that the MOBA nanoparticles with sizes of 300-800 nm decorated the surface of the biodegradable substrate and formed porous agglomerates, which have sizes of 1-3 µm. The MOBA powders were dispersed in drinking water polluted with BAM and were exposed to 4 h of UV-VIS irradiation, producing a maximum degradation of 82% for the BAM. Moreover, the flexible and biodegradable rice/MOBA composite produced a maximum removal percentage of 95% for the BAM. Also, we studied the effect of pH of the initial solution utilizing both powders and composites. From here, we found that a pH of 10 leads to a complete degradation of BAM after 4h, while a pH of 3 degraded only 37-47% of BAM for the same reaction time. According to the scavenger experiments, the •OH radical and the h+ were the main oxidizing agents for the BAM. Overall, the biodegradable photocatalytic composites are a reliable and a low-cost alternative to eliminate pesticides from the drinking water and can find application in water purification processes.


Asunto(s)
Agua Potable , Nanopartículas , Oryza , Plaguicidas , Phyllobacteriaceae , Benzamidas , Oryza/metabolismo , Plaguicidas/metabolismo , Phyllobacteriaceae/metabolismo , Polvos
9.
Clin Oral Investig ; 26(3): 2587-2595, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34839418

RESUMEN

OBJECTIVES: This study aims to evaluate the usefulness of liquid-based brush cytology for malignancy diagnosis and HPV detection in patients with suspected oropharyngeal and oral carcinomas, as well as for the diagnosis of tumoral persistence after treatment. MATERIAL AND METHODS: Seventy-five patients with suspicion of squamous cell carcinoma of the oropharynx or oral cavity were included. Two different study groups were analyzed according to the date of the sample collection: (1) during the first endoscopy exploration and (2) in the first control endoscopy after treatment for squamous cell carcinoma. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for malignancy diagnosis as well as for HPV-DNA detection on brush cytologies were assessed. RESULTS: Before treatment, the brush cytology showed a sensitivity of 88%, specificity of 100%, and accuracy of 88%. After treatment, it showed a sensitivity of 71%, specificity of 77%, and accuracy of 75%. HPV-DNA detection in cytology samples showed a sensitivity of 85%, specificity of 100%, and accuracy of 91% before treatment and an accuracy of 100% after treatment. CONCLUSIONS: Liquid-based brush cytology showed good accuracy for diagnosis of oropharyngeal and oral squamous cell carcinoma before treatment, but its value decreases after treatment. Nevertheless, it is useful for HPV-DNA detection, as well as to monitor the patients after treatment. CLINICAL RELEVANCE: Brush cytology samples are reliable for the detection of HPV-DNA before and after treatment and may be a useful method to incorporate in the HPV testing guidelines.


Asunto(s)
Carcinoma de Células Escamosas , Neoplasias de Cabeza y Cuello , Neoplasias de la Boca , Neoplasias Orofaríngeas , Infecciones por Papillomavirus , Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/patología , Carcinoma de Células Escamosas/terapia , Humanos , Neoplasias de la Boca/diagnóstico , Neoplasias de la Boca/patología , Neoplasias de la Boca/terapia , Neoplasias Orofaríngeas/diagnóstico , Neoplasias Orofaríngeas/patología , Neoplasias Orofaríngeas/terapia , Orofaringe , Infecciones por Papillomavirus/diagnóstico , Sensibilidad y Especificidad
10.
In. Rodríguez Milord, Daniel Otmaro (†); González Cruz, Roberto. Vigilancia de la salud pública. Experiencia cubana. La Habana, Editorial Ciencias Médicas, 2022. , tab.
Monografía en Español | CUMED | ID: cum-78435
11.
J Oral Pathol Med ; 50(3): 280-286, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31006144

RESUMEN

BACKGROUND: Oral premalignant lesions (OPML) are frequently extensive and multifocal leading high morbidity for patients. Although oral squamous carcinoma (OSCC) in non-smoker patients is increasing, little is known about OPML and the carcinogenesis process in these patients. The aims of the study were to insight and compare the clinicopathological and molecular characteristics of OPML of non-smoker and smoker patients from which one or multiple OSCC have developed. METHODS: Eighty-one patients showing extensive and/or multifocal OPML were included in the survey. HPV and EBV were investigated by PCR and in situ hybridization respectively. Cytogenetic studies were performed by microarray in sequential progressive 30 lesions; p53 expression was investigated by immunohistochemistry. RESULTS: The patients were 41 males and 40 females, ages ranging from 32 to 93 years (median 64); 43 (53%) were smokers. Non-smokers were more frequently female with a median age of 68, whereas smokers were men with a median age of 60 (P = 0.005). HPV and EBV were negative in all cases. The most consistent and earliest cytogenetic alterations in both non-smokers and smokers were loss of heterozygosity (LOH) and losses of locus harboring tumor suppressor genes. Progression to high-grade dysplasia and OSCC showed progressive addition of LOH, tumor suppressor losses, and oncogenic gains. CONCLUSION: Non-smoker patients are mostly elderly female and show oral carcinogenic pathways and outcomes similar to smoker patients.


Asunto(s)
Neoplasias de la Boca , Lesiones Precancerosas , Adulto , Anciano , Anciano de 80 o más Años , Carcinogénesis/genética , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neoplasias de la Boca/genética , No Fumadores , Lesiones Precancerosas/genética , Fumadores
12.
Sci Rep ; 7(1): 1524, 2017 05 08.
Artículo en Inglés | MEDLINE | ID: mdl-28484284

RESUMEN

Light-emitting electrochemical cells (LECs) with the thermally activated delayed fluorescence(TADF) host and phosphorescent guests were fabricated using solution process. It is demonstrated for the first time that TADF, a well-known phenomenon that helps to increase electroluminescence efficiency by harvesting excitons from triplet states, is used as a host in LECs. Devices with green, yellow, red and warm white emissions were fabricated, with the best devices showing more than 7000 cd/m2 stable emission and a peak efficiency over 7 cd/A. Under high voltage stress, a burst of extremely high luminance of over 30,000 cd/m2 was observed. All these LEC devices are extremely simple with only one active layer. Thus, our results could pave way to produce low- cost light source with high luminance, using TADF molecules.

13.
Virchows Arch ; 469(3): 277-84, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27392929

RESUMEN

High-grade neuroendocrine carcinomas (HGNECs) of the head and neck have the morphological appearance of undifferentiated carcinomas and could be histologically similar to human papillomavirus (HPV)-associated non-keratinizing squamous cell carcinomas of the head and neck. The aim of the study is to characterize histologically, immunohistochemically, and virologically these unusual neoplasms. Nineteen HGNECs of the head and neck (1 oropharyngeal, 5 sinonasal, 7 of the larynx, and 6 of the parotid gland) were reviewed and analyzed with a immunohistochemical panel, with special emphasis on cell cycle proteins. The tumors were tested for HPV by in situ hybridization (GenPoint HPV, Dako) and PCR (SPF10-DEIA-LiPA25). Merkel cell polyomavirus was studied using the antibody CM2B4. Fifteen HGNEC were of small cell and 4 of large cell type. Most of the tumors (14/19, 73.7 %), including all the pure small cell carcinomas, showed a strong and diffuse positive staining for p16. Eleven of them (78.5 %) had Rb loss and a low or absent cyclin D1 expression. All cases were negative for HPV and polyomavirus. Most patients were smokers, diagnosed at advanced stages of the disease, and had a poor outcome, with a 5-year survival of 18 %. In conclusion, HGNECs of the head and neck are infrequently related to HPV infection, but usually show strong, diffuse positive p16 immunostaining due to Rb pathway dysregulation. Awareness of this immunohistochemical pattern of expression may avoid a potential diagnostic pitfall with HPV-associated non-keratinizing squamous cell carcinomas, which have a better prognosis.


Asunto(s)
Carcinoma Neuroendocrino/virología , Inhibidor p16 de la Quinasa Dependiente de Ciclina/metabolismo , Neoplasias de Cabeza y Cuello/patología , Neoplasias de Cabeza y Cuello/virología , Infecciones por Papillomavirus/virología , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/análisis , Carcinoma Neuroendocrino/genética , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patología , Inhibidor p16 de la Quinasa Dependiente de Ciclina/genética , ADN Viral/genética , Femenino , Neoplasias de Cabeza y Cuello/genética , Humanos , Inmunohistoquímica/métodos , Masculino , Persona de Mediana Edad , Papillomaviridae
14.
Nanoscale ; 8(23): 11862-9, 2016 Jun 09.
Artículo en Inglés | MEDLINE | ID: mdl-27230115

RESUMEN

This work presents the design of substrates for Surface Enhanced Raman Scattering (SERS) using star-like gold nanoparticles synthesized by a wet chemical method. The SERS substrates were used for glucose detection for concentrations as low as 10(-7) M, which represents an enhancement factor (EF) of 10(9), as a result of the hot spot formed by the spike termination and appropriate distribution of the gold nanoparticles. An improvement of two orders of magnitude was obtained by coating the gold nanoparticles with albumin with the configuration: glass/Au nanoparticles/albumin. In this case the lowest detection was at a concentration of 10(-9) M for an EF of 10(11). The albumin molecule allowed us to enhance the Raman signal because of the formation of peptide bonds (COOH-NH2) generated due to the interaction of glucose with albumin, and the appropriate separation distance between the glucose molecules and gold nanoparticles. The presence of such peptide conjugates was confirmed by FTIR spectra. Thus, our results suggest that our SERS substrates can be useful for the detection of very low concentrations of glucose, which is important for the diagnosis of diabetes in the field of medicine.

15.
Oncology ; 90(5): 267-72, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27077749

RESUMEN

BACKGROUND: Patients with head and neck squamous cell carcinoma (HNSCC) present different responses to chemotherapy and radiotherapy. One explanation may be the differences in the individual rates of stem cell-like cells. METHODS: We included patients with HNSCC and tumor progression or relapse. Tumor samples were obtained before and after primary chemotherapy, and immunohistochemical analyses were performed for CD44, HLA class I (HLA-I), pancytokeratin, and phosphorylated epidermal growth factor receptor (p-EGFR). Differences in expression between the first and second specimens were assessed. RESULTS: Expression between the first and second specimens varied as follows: CD44 increased by 14.67% (95% confidence interval, CI: 6.94 to 22.40; p < 0.01); HLA-I decreased by 16.72% (95% CI: -23.87 to -9.47; p < 0.01); pancytokeratin decreased by 24.91% (95% CI: -32.8 to -17.7; p < 0.01), and p-EFGR expression decreased by 12.30% (95% CI: -20.61 to -3.98; p < 0.005). CONCLUSIONS: Among patients with HNSCC, there is an enrichment of cells with stem-like markers in relapsed tumors when compared with the primary tumor. This finding should be considered when developing treatment strategies.


Asunto(s)
Biomarcadores de Tumor/análisis , Carcinoma de Células Escamosas/patología , Neoplasias de Cabeza y Cuello/patología , Células Madre Neoplásicas , Adulto , Anciano , Carcinoma de Células Escamosas/química , Carcinoma de Células Escamosas/tratamiento farmacológico , Progresión de la Enfermedad , Receptores ErbB/análisis , Femenino , Neoplasias de Cabeza y Cuello/química , Neoplasias de Cabeza y Cuello/tratamiento farmacológico , Antígenos de Histocompatibilidad Clase I/análisis , Humanos , Receptores de Hialuranos/análisis , Queratinas/análisis , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia
16.
Photochem Photobiol ; 92(2): 231-237, 2016 03.
Artículo en Inglés | MEDLINE | ID: mdl-26787254

RESUMEN

The photocatalytic activity of Bismuth-codoped Sr4 Al14 O25 : Eu2+ , Dy3+ persistent phosphors is studied by monitoring the degradation of the blue methylene dye UV light irradiation. Powder phosphors are obtained by a combustion synthesis method and a postannealing process in reductive atmosphere. The XRD patterns show a single orthorhombic phase Sr4 Al14 O25 : Eu2+ , Dy3+ , Bi3+ phosphors even at high Bismuth dopant concentrations of 12 mol%, suggesting that Bi ions are well incorporated into the host lattice. SEM micrographs show irregular micrograins with sizes in the range of 0.5-20 µm. The samples present an intense greenish-blue fluorescence and persistent emissions at 495 nm, attributed to the 5d-4f allowed transitions of Eu2+ . The fluorescence decreases as Bi concentration increases; that suggest bismuth-induced traps formation that in turn quench the luminescence. The photocatalytic evaluation of the powders was studied under both 365 nm UV and solar irradiations. Sample with 12 mol% of Bi presented the best MB degradation activity; 310 min of solar irradiation allow 100% MB degradation, whereas only 62.49% MB degradation is achieved under UV irradiation. Our results suggest that codoping the persistent phosphors with Bi3+ can be an alternative to enhance their photocatalytic activity.

17.
Nanoscale ; 7(22): 10249-58, 2015 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-25990708

RESUMEN

This work presents the design of substrates for Surface Enhanced Raman Scattering (SERS) using star-like gold nanoparticles which were synthesized using a wet chemical method and functionalized with 1-dodecanethiol. This molecule allowed us to obtain a spacing of ∼2.6 nm among gold stars, which promoted the generation of SERS hotspots for single molecule detection. The gold nanoparticles were deposited on silicon substrates or on gold coated silicon substrates by using the Langmuir-Blodgett method which permitted the zeptomole detection of Rhodamine B (total moles per laser spot area). The Raman enhancement factor (EF) achieved for this level of detection was 10(12), and was obtained on the SERS substrate fabricated with the configuration: Si/Au film/Au nanoparticles. Raman spectra of the molecules TWEEN 20 and p-terphenyl were also measured in order to elucidate the effect of the molecule's length on the enhancement factor. According to these results, our SERS substrates without the gold film are useful for a minimum detection level of ∼10(-14) moles of analytes with sizes equal to or less than 1.3 nm and ∼10(-18) moles of analytes with the gold film (total moles per sample).

18.
J Biomed Opt ; 20(4): 046006, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25879389

RESUMEN

This work reports the synthesis, structural characterization, and optical properties of ZrO2:Yb(3+)-Er(3+) (2­1 mol%) nanocrystals. The nanoparticles were coated with 3-aminopropyl triethoxysilane (APTES) and further modified with biomolecules, such as Biotin-Anti-rabbit (mouse IgG) and rabbit antibody-AntiKi-67, through a conjugation method. The conjugation was successfully confirmed by Fourier transform infrared, zeta potential, and dynamic light scattering. The internalization of the conjugated nanoparticles in human cervical cancer (HeLa) cells was followed by two-photon confocal microscopy. The ZrO2:Yb(3+)-Er(3+) nanocrystals exhibited strong red emission under 970-nm excitation. Moreover, the luminescence change due to the addition of APTES molecules and biomolecules on the nanocrystals was also studied. These results demonstrate that ZrO2:Yb(3+)-Er(3+) nanocrystals can be successfully functionalized with biomolecules to develop platforms for biolabeling and bioimaging.


Asunto(s)
Mediciones Luminiscentes/métodos , Nanopartículas del Metal/química , Nanopartículas del Metal/ultraestructura , Fracciones Subcelulares/química , Fracciones Subcelulares/patología , Circonio/química , Medios de Contraste/química , Erbio/química , Células HeLa , Humanos , Tamaño de la Partícula , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Coloración y Etiquetado/métodos , Iterbio/química
19.
Photochem Photobiol ; 91(3): 505-9, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25648573

RESUMEN

The photocatalytic activity, of undoped and Europium-doped LaSr2 AlO5 powders, has been investigated by degrading methylene blue dye in water solutions. Those powders were fabricated by a combustion method and an annealing treatment in air. All samples showed a tetragonal single phase according to by X-ray diffraction measurements (XRD). Scanning electron microscopy (SEM) revealed irregular semi-oval grains with sizes in the range of 3.5-4.27 µm. Photoluminescence spectrum showed sharp emission peaks at 588 nm and at 617 nm which are associated with (7) F1 ,(7) F2 → (5) D0 Eu(3+) ion forbidden transitions, respectively, under UV light excitation of 322 nm. The methylene blue (MB) degradation under UV light (254 nm) was studied by monitoring changes in the absorbance peak of MB at 665 nm. Finally, LaSr2 AlO5 :Eu powders were used three times and the efficiency for the degradation of MB decreased from 100 to 61% after the third cycle of use.

20.
Artículo en Español | LILACS | ID: lil-505142

RESUMEN

La Enfermedad Renal Crónica (ERC) es reconocida como un problema de salud y un reto internacionalmente, a considerar como parte central del planeamiento de la salud pública de cada Estado, por su complejidad, frecuencia y crecimiento epidémico. El número real de pacientes prevalentes en cualquier etapa evolutiva de ERC podría afectar a 10-14 por ciento de la población adulta. Sólo en métodos de diálisis y trasplante viven más de 2 millones de personas en todo el mundo. El presupuesto dedicado a estos enfermos es muy alto y existen enormes disparidades en su atención entre los países pobres y ricos, reconocidas internacionalmente. El sistema de Salud Pública en Cuba, estatal, universal, gratuito y accesible para toda la población de más de 11 millones de habitantes, se mantiene en continuo desarrollo y perfeccionamiento para alcanzar la excelencia en la atención y cumple estos mismos preceptos en la garantía de la atención nefrológica. Necesidades y costos crecientes en tiempo de crisis económica, pese a que cada año más y más enfermos requieren de terapia renal de reemplazo por diálisis y trasplante renal, lo cual alcanzó en 2007 un número de pacientes de 284.8 por millón de población en el país. Esta Organización se puso a prueba en los dos recientes huracanes que azotaron catastróficamente a Cuba, lo cual significó una experiencia única en nuestro país y motivó escribir esta reseña.


End-stage renal failure is a health problem in the World. The cuban national careprogram to the pattients with renal failure, has specific guides for action in the primary renal care. It is carried out by family physicians ; and it intends to supply attention at risk population; secondary renal care, and provides clinical nephrology services, for pattients suffering of chronic renal disease, to delay progression of their illness, and avoid complications; and terciary renal care, carried out by renal replacement therapy services, for End Stage Renal Disease pattients, to attain pattient’s social rehabilitation and have the surveillance Systems Give First Alert in Nephrology for abnormal or disasters situations. This role presents the main structural organizational features of the activities in Cuba for renal care aftermath the hurricanes situation.This is the priority for the Cuban State of granting the attendance prescribes and the life of these patients.


Asunto(s)
Humanos , Insuficiencia Renal Crónica/patología , Desastres Naturales , Diálisis Renal , Sistema de Vigilancia de Factor de Riesgo Conductual
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