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1.
Phys Rev Lett ; 132(3): 036702, 2024 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-38307068

RESUMEN

Altermagnetism is a newly identified fundamental class of magnetism with vanishing net magnetization and time-reversal symmetry broken electronic structure. Probing the unusual electronic structure with nonrelativistic spin splitting would be a direct experimental verification of an altermagnetic phase. By combining high-quality film growth and in situ angle-resolved photoemission spectroscopy, we report the electronic structure of an altermagnetic candidate, α-MnTe. Temperature-dependent study reveals the lifting of Kramers degeneracy accompanied by a magnetic phase transition at T_{N}=267 K with spin splitting of up to 370 meV, providing direct spectroscopic evidence for altermagnetism in MnTe.

2.
Nanotechnology ; 35(12)2024 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-38064735

RESUMEN

Ferromagnetic insulators (FMIs) are intriguing not only due to their rare nature, but also due to their potential applications in spintronics and various electronic devices. One of its key promising applications is based on an FMI-induced magnetic proximity effect, which can impose an effective time-reversal symmetry breaking on the target ultrathin layer to realize novel emergent phenomena. Here, we conduct systematic studies on thin film LaCoO3, an insulator known to be ferromagnet under tensile strain, with varying thicknesses, to establish it as an FMI platform to be integrated in heterostructures. The optimal thickness of the LaCoO3layer, providing a smooth surface and robust ferromagnetism with large remanence, is determined. A heterostructure consisting of an ultrathin target layer (2 uc SrRuO3), the LaCoO3FMI layer, and the La0.5Sr0.5CoO3conducting layer has been fabricated and the angle-resolved photoemission spectroscopy measurement on the multi-layer system demonstrates a sharp Fermi edge and a well-defined Fermi surface without the charging effect. This demonstrates the feasibility of the proposed heterostructure using LaCoO3thin film as the FMI layer, and further lays a groundwork to investigate the magnetic proximity induced phases in quantum materials.

3.
Artículo en Inglés | MEDLINE | ID: mdl-38082909

RESUMEN

Stimuli-responsive soft robots have provided new directions for obtaining advanced biomedical healthcare systems, such as targeted drug delivery capsules, less-invasive biopsy tools, and untethered microsurgical robots. We designed, 3D printed, and tested diverse time-dependent shape changeable 3D pH-responsive soft grippers consisting of N-isopropylacrylamide (NIPAM) and N-isopropylacrylamide-co-acrylic acid (NIPAM-AAc) bilayer. We found that the swelling/deswelling-driven actuation of the pH-responsive NIPAM/NIPAM-AAc gripper is primarily affected by the volume percent (% v/v) of the acrylic acid (AAc) and intensity of UV light. We expect that this study can be applied to untethered pH-responsive soft grippers as smart drug delivery capsules or biopsy tools in biomedical healthcare systems.


Asunto(s)
Hidrogeles , Impresión Tridimensional , Concentración de Iones de Hidrógeno
4.
Nano Lett ; 23(16): 7273-7278, 2023 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-37552567

RESUMEN

Copper-based high-temperature superconductors share a common feature in their crystal structure, which is the presence of a CuO2 plane, where superconductivity takes place. Therefore, important questions arise as to whether superconductivity can exist in a single layer of the CuO2 plane and, if so, how such superconductivity in a single CuO2 plane differs from that in a bulk cuprate system. To answer these questions, studies of the superconductivity in cuprate monolayers are necessary. In this study, we constructed a heterostructure system with a La2-xSrxCuO4 (LSCO) monolayer containing a single CuO2 plane and measured the resulting electronic structures. Monolayer LSCO has metallic and bulk-like electronic structures. The hole doping ratio of the monolayer LSCO is found to depend on the underlying buffer layer due to the interface effect. Our work will provide a platform for research into ideal two-dimensional cuprate systems.

5.
Cells ; 12(14)2023 07 14.
Artículo en Inglés | MEDLINE | ID: mdl-37508518

RESUMEN

One major challenge associated with lung cancer organoids (LCOs) is their predominant derivation from surgical specimens of patients with early-stage lung cancer. However, patients with advanced lung cancer, who are in need of chemotherapy, often cannot undergo surgery. Therefore, there is an urgent need to successfully generate LCOs from biopsy specimens. Conventional lung biopsy techniques, such as transthoracic needle biopsy and forceps biopsy, only yield small amounts of lung tissue, resulting in a low success rate for culturing LCOs from biopsy samples. Furthermore, potential complications, like bleeding and pneumothorax, make it difficult to obtain sufficient tissue. Another critical issue is the overgrowth of normal lung cells in later passages of LCO culture, and the optimal culture conditions for LCOs are yet to be determined. To address these limitations, we attempted to create LCOs from cryobiopsy specimens obtained from patients with lung cancer (n = 113). Overall, the initial success rate of establishing LCOs from cryobiopsy samples was 40.7% (n = 46). Transbronchial cryobiopsy enables the retrieval of significantly larger amounts of lung tissue than bronchoscopic forceps biopsy. Additionally, cryobiopsy can be employed for peripheral lesions, and it is aided via radial endobronchial ultrasonography. This study significantly improved the success rate of LCO culture and demonstrated that the LCOs retained characteristics that resembled the primary tumors. Single-cell RNA sequencing confirmed high cancer cell purity in early passages of LCOs derived from patients with advanced lung cancer. Furthermore, the three-dimensional structure and intracellular components of LCOs were characterized using three-dimensional holotomography. Finally, drug screening was performed using a specialized micropillar culture system with cryobiopsy-derived LCOs. LCOs derived from cryobiopsy specimens offer a promising solution to the critical limitations of conventional LCOs. Cryobiopsy can be applied to patients with lung cancer at all stages, including those with peripheral lesions, and can provide sufficient cells for LCO generation. Therefore, we anticipate that cryobiopsy will serve as a breakthrough strategy for the clinical application of LCOs in all stages of lung cancer.


Asunto(s)
Criocirugía , Neoplasias Pulmonares , Humanos , Broncoscopía/métodos , Criocirugía/métodos , Neoplasias Pulmonares/patología , Pulmón/patología , Organoides/patología
6.
Child Health Nurs Res ; 29(1): 51-59, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36760112

RESUMEN

PURPOSE: This study investigated correlations between the actual sleep time 24 hours prior to an examination and the time to achieve chloral hydrate sedation in pediatric patients. METHODS: With parental consent, 84 children who were placed under moderate or deep sedation with chloral hydrate for examinations from November 19, 2020 to July 9, 2022 were recruited. RESULTS: Patients' average age was 19.9 months. Pediatric neurology patients and those who underwent electroencephalography took significantly longer to achieve sedation with chloral hydrate. There was a negative correlation between the time to achieve sedation and actual sleep time within 24 hours prior to the examination. Positive correlations were found between the actual sleep time 24 hours prior to the examination and the second dose per weight, as well as between the sedation recovery time and awake hours before the examination. CONCLUSION: Sleep restriction is not an effective adjuvant therapy for chloral hydrate sedation in children, and sedation effects vary according to pediatric patients' characteristics. Therefore, it would be possible to reduce the unnecessary efforts of caregivers who restrict children's sleep for examinations. It is more important to educate parents about safe sedation than about sleep restriction.

7.
J Vis Exp ; (191)2023 01 13.
Artículo en Inglés | MEDLINE | ID: mdl-36715416

RESUMEN

The present protocol describes the creation of four-dimensional (4D), time-dependent, shape-changeable, stimuli-responsive soft robots using a three-dimensional (3D) bio-printing method. Recently, 4D printing techniques have been extensively proposed as innovative new methods for developing shape-transformable soft robots. In particular, 4D time-dependent shape transformation is an essential factor in soft robotics because it allows effective functions to occur at the right time and place when triggered by external cues, such as heat, pH, and light. In line with this perspective, stimuli-responsive materials, including hydrogels, polymers, and hybrids, can be printed to realize smart shape-transformable soft robotic systems. The current protocol can be used to fabricate thermally responsive soft grippers composed of N-isopropylacrylamide (NIPAM)-based hydrogels, with overall sizes ranging from millimeters to centimeters in length. It is expected that this study will provide new directions for realizing intelligent soft robotic systems for various applications in smart manipulators (e.g., grippers, actuators, and pick-and-place machines), healthcare systems (e.g., drug capsules, biopsy tools, and microsurgeries), and electronics (e.g., wearable sensors and fluidics).


Asunto(s)
Robótica , Polímeros de Estímulo Receptivo , Hidrogeles , Robótica/métodos , Polímeros , Impresión Tridimensional
8.
Annu Int Conf IEEE Eng Med Biol Soc ; 2022: 2540-2543, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-36086195

RESUMEN

Soft robots offer unique advantages in their ability to interact with fragile organisms. Light responsive soft actuators are promising for the development of the untethered soft robots. However, this requires a mechanism for converting the externally applied light into mechanical actuation. We designed, fabricated, and tested a light responsive soft actuator consist of silicone elastomer with plasmonic metal nanoparticle embedment and temperature sensitive hydrogel. We found that the selection of the carrier solvent for the metal nanoparticle embedment in silicone elastomer to be crucial. The fabricated soft actuator showed a relatively fast response time (< 5 min) under light illumination.


Asunto(s)
Hidrogeles , Robótica , Elastómeros de Silicona , Temperatura
9.
ACS Appl Mater Interfaces ; 13(34): 40976-40985, 2021 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-34407611

RESUMEN

Among various available materials used in transparent and flexible devices, MXenes are attracting attention as a brand-new candidate in this category. Ti3C2Tx MXene as a 2D material has exceptional properties, making it a potential material having numerous applications in different areas. Because of its high conductivity, it can be used in transparent conducting electrodes (TCEs). In this study, the MXenes etched by highly concentrated acid at 50 °C,were spin-coated on polyethylene terephthalate (PET) film and annealed at moderate temperatures up to 170 °C. The adhesion of MXene to PET was found to be remarkably improved by annealing. These TCEs exhibited a sheet resistance of ∼424 Ω/sq. and transmittance of ∼87%. The aging stability of MXene-coated PET films against oxidation under ambient conditions was studied up to 28 days and resistance change was found ∼30% during this period. The flexibility test showed low bending resistance change (∼1.5%) at 1000th cycle and cumulative resistance change of ∼20% at a bending radius of ∼3.9 mm after 1000 cycles. These transparent, flexible, and conducting electrodes were used to fabricate polymer dispersed liquid crystal (PDLC)-based flexible smart windows. The smart windows fabricated by curing PDLC mixture sandwiched between the MXene electrodes were also found flexible in ON/OFF states. The MXene-based flexible smart windows resulted in good opacity in the OFF state and high transparency in the ON state, exhibiting low threshold voltage <10 V and high transmittance ∼80% at 60 V. The flexible smart windows operated normally even at ∼4 mm bending radius.

10.
Food Sci Nutr ; 9(8): 4169-4175, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34401068

RESUMEN

Vitamin D is critical to brain function and its deficiency accelerates cognitive impairment. There is limited understanding of the brain-specific areas that undergo volume change in relation to blood vitamin D levels. The objective of this study was to evaluate the association between blood 25-hydroxyvitamin D (25(OH)D) concentration and structural changes in the brain. We analyzed structural three-dimensional T1 MRI images of 201 elderly individuals (mean age = 74.91 ± 9.21 years; 68.1% female; mean 25(OH)D = 18.05 nmol/L), with 10 community-based normal healthy subjects, 33 with subjective cognitive decline, 97 with mild cognitive impairment, and 61 with Alzheimer's disease (AD). To analyze the structural changes in the brain respective to blood 25(OH)D, multiple regression analyses were performed using voxel-based morphometry with age and total intracranial volume as covariates. Lower 25(OH)D level were associated with reduced brain volume in right olfactory, rectus GM regions (FWE-corr, p < .05) for entire subjects. For AD subjects, left parahippocampal, fusiform, and hippocampal areas were positively associated with 25(OH)D (FWE-corr, p < .05). Low blood 25(OH)D was associated with reduced volumes in olfactory and hippocampal regions in elderly patients with cognitive decline. Our results may provide insight into the neurological pathophysiology of vitamin D.

11.
J Cell Mol Med ; 25(19): 9460-9472, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34464509

RESUMEN

Fas-associated factor 1 (FAF1) has gained a reputation as a member of the FAS death-inducing signalling complex. However, the role of FAF1 in the immunity response is not fully understood. Here, we report that, in the human retinal pigment epithelial (RPE) cell line ARPE-19 cells, FAF1 expression level was downregulated by Toxoplasma gondii infection, and PI3K/AKT inhibitors reversed T. gondii-induced FAF1 downregulation. In silico analysis for the FAF1 promoter sequence showed the presence of a FOXO response element (FRE), which is a conserved binding site for FOXO1 transcription factor. In accordance with the finding, FOXO1 overexpression potentiated, whereas FOXO1 depletion inhibited intracellular FAF1 expression level. We also found that FAF1 downregulation by T. gondii is correlated with enhanced IRF3 transcription activity. Inhibition of PI3K/AKT pathway with specific inhibitors had no effect on the level of T. gondii-induced IRF3 phosphorylation but blocked IRF3 nuclear import and ISGs transcription. These results suggest that T. gondii can downregulate host FAF1 in PI3K/AKT/FOXO1-dependent manner, and the event is essential for IRF3 nuclear translocation to active the transcription of ISGs and thereby T. gondii proliferation.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/genética , Proteínas Reguladoras de la Apoptosis/genética , Regulación de la Expresión Génica , Interacciones Huésped-Parásitos/genética , Factor 3 Regulador del Interferón/metabolismo , Toxoplasma/fisiología , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Proteínas Reguladoras de la Apoptosis/metabolismo , Línea Celular , Células Cultivadas , Técnica del Anticuerpo Fluorescente , Proteína Forkhead Box O1/metabolismo , Humanos , Factor 3 Regulador del Interferón/genética , Fosfatidilinositol 3-Quinasas/metabolismo , Fosforilación , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal , Toxoplasmosis/genética , Toxoplasmosis/metabolismo , Toxoplasmosis/parasitología
12.
J Clin Med ; 10(10)2021 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-34064891

RESUMEN

Acupuncture point (AP) selections can vary depending on clinicians' acupuncture style, and therefore, acupuncture style is an important factor in determining the efficacy of acupuncture treatment. However, few studies have examined the differences in AP selections according to the acupuncture styles and theoretical backgrounds causing the differences. We compared the AP prescriptions used for 14 diseases in three classical medical textbooks, Dongeuibogam (DEBG), Saamdoinchimgooyogyeol (SADI), and Chimgoogyeongheombang (CGGHB), which represent unique acupuncture styles and have affected clinicians during this time. AP prescriptions showed more diversity between textbooks than between types of diseases. Among the three textbooks, AP prescriptions of SADI were most different compared to those of DEBG and CGGHB. Importantly, we found each style can be more clearly explained by AP attributes than by the APs per se. Specifically, SADI, DEBG, and CGGHB preferred five transport points located on the limbs, APs of the extra meridians, and source points, respectively. This suggests the possibility that the theoretical diversity of acupuncture styles results in the heterogeneity of AP selections.

13.
Nano Lett ; 20(3): 1934-1943, 2020 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-32083883

RESUMEN

Among p-n junction devices with multilayered heterostructures with WSe2 and MoSe2, a device with the MoSe2-WSe2-MoSe2 (NPN) structure showed a remarkably high photoresponse, which was 1000 times higher than the MoSe2-WSe2 (NP) structure. The ideality factor of the NPN structure was estimated to be ∼1, lower than that of the NP structure. It is claimed that the NPN structure formed a thinner depletion region than that of the NP structure because of the difference of carrier concentrations of MoSe2 and WSe2. Hence, the built-in electric field was weaker, and the motion of the photocarriers was facilitated. These behaviors were confirmed experimentally from a photocurrent mapping analysis and Kelvin probe force microscopy. The work function depended on the wavelength of the illuminator, and quasi-Fermi level was estimated. The surface photovoltage on the MoSe2 region was higher than that on WSe2 because the lower bandgap of MoSe2 induces more electron-hole pair generation.

14.
RSC Adv ; 10(68): 41837-41845, 2020 Nov 11.
Artículo en Inglés | MEDLINE | ID: mdl-35516536

RESUMEN

The effect of Ti3C2T x MXene etched at different temperatures (25 °C, 50 °C, and 80 °C) on the capacitance of supercapacitors without the use of conducting carbon-black or a binder was studied. The MXene etched using concentrated HCl acid (12 M)/LiF was used as an active electrode and Ni-foil as a current collector. It was observed that the elevated etching temperature facilitates the etching of the MAX phase and the exfoliation of MXene layers. However, this led to the formation of additional functional groups at the MXene surface as the temperature was increased to 80 °C. The specific capacitance of Ti3C2T x -based supercapacitors increased from 581 F g-1 for MXene etched at 25 °C to 657 F g-1 for those etched at 50 °C at the scan rate of 2 mV s-1. However, the specific capacitance reduced to 421 F g-1 as the etching temperature was increased to 80 °C at the same scan rate. The supercapacitors based on MXenes etched at the intermediate temperature (50 °C) exhibited higher specific capacitance in a wide range of scan rate, symmetry in charge/discharge curves, high cyclic stability at a scan rate of 1000 mV s-1 for up to 3000 cycles. The electrochemical impedance spectroscopy studies indicated low series resistance, reduced charge-transfer resistance, and decreased Warburg impedance for the supercapacitor based on the MXene etched at the intermediate temperature.

15.
J Vet Med Sci ; 80(12): 1905-1913, 2018 Dec 26.
Artículo en Inglés | MEDLINE | ID: mdl-30369585

RESUMEN

Stem cell therapy has been proposed to restore the function and structure of injured tissues. In the present study, we investigated the ability of human endothelial progenitor cells (hEPCs) to attenuate ovarian aging and dysfunction. Female ICR mice aged 4 and 6 months were injected with cultured hEPCs. Cultured hEPCs were injected intravenously twice with 5 × 104 cells with a 4 day interval. After pregnant mare serum gonadotropin and human chorionic gonadotropin stimulation, oocytes and ovaries of aged mice were collected, cumulus-free oocytes were activated by SrCl2 and gene expression levels related to inflammation, apoptosis, follicle development and endoplasmic reticulum (ER) stress in ovaries were compared. Administration of hEPCs attenuated the level of inflammatory cytokines and adverse apoptotic factor, as well as reducing ER stress in the ovaries. Increased cleavage and blastocyst formation rates and cell numbers in blastocysts from hEPCs-treated aged mice vs. same aged control mice demonstrated a protective function of hEPCs against reproductive aging. Based on these data, we suggest that treatment with hEPCs attenuates reproductive aging and dysfunction potentially via regulation of inflammation, apoptosis and ER stress.


Asunto(s)
Envejecimiento , Apoptosis , Desarrollo Embrionario , Estrés del Retículo Endoplásmico , Células Progenitoras Endoteliales/trasplante , Inflamación/prevención & control , Ovario/fisiología , Envejecimiento/genética , Animales , Células Cultivadas , Citocinas/genética , Citocinas/metabolismo , Femenino , Fertilidad , Expresión Génica , Humanos , Mediadores de Inflamación/metabolismo , Ratones , Ratones Endogámicos ICR , Folículo Ovárico/crecimiento & desarrollo , Ovario/metabolismo , Partenogénesis , Trasplante Heterólogo
16.
J Vasc Interv Radiol ; 21(3): 348-56, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20116285

RESUMEN

PURPOSE: To assess the diagnostic value of gadoxetic acid-enhanced magnetic resonance (MR) imaging in follow-up of patients with hepatocellular carcinomas (HCCs) who were treated with radiofrequency (RF) ablation and to compare it with that of four-phase multi-detector row computed tomography (CT). MATERIALS AND METHODS: From July 2007 to May 2008, 36 patients (43 HCCs) were enrolled who were treated with RF ablation (tumor size, 20-47 mm; mean, 24.5 mm) and underwent gadoxetic acid-enhanced MR imaging and four-phase (precontrast, arterial, portal venous, and equilibrium) multidetector CT for follow-up. Two radiologists independently reviewed these images, and conspicuity of tumor margins and detection of residual or recurrent tumor were assessed on a five-point scale with receiver operating characteristic (ROC) curve analysis. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were evaluated. RESULTS: The mean conspicuity value of tumor margins was significantly higher on MR imaging than on multidetector CT (P < .001). The degree of differentiation between residual/recurrent tumor and hyperemia was significantly greater on MR imaging (P < .001). The mean area under the ROC curve was significantly higher with MR imaging (P = .015), as were sensitivity, specificity, PPV, NPV, and accuracy of detection rate (mean, 100%, 96.2%, 82.4%, 100%, and 96.7%, respectively, vs 41.7%, 56.8%, 13.5%, 85.7%, and 54.7% for multidetector CT). The interobserver agreement rate for MR imaging was higher (0.919) than for multidetector CT (0.672; P < .05). CONCLUSIONS: Diagnostic accuracy, conspicuity of tumor margins, and detection rate of residual or recurrent tumor were found to be better with gadoxetic acid-enhanced MR imaging than with four-phase multidetector CT.


Asunto(s)
Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/cirugía , Gadolinio DTPA , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/cirugía , Imagen por Resonancia Magnética/métodos , Tomografía Computarizada por Rayos X/métodos , Adulto , Anciano , Anciano de 80 o más Años , Medios de Contraste , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Resultado del Tratamiento
17.
Antiviral Res ; 68(3): 109-15, 2005 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-16290278

RESUMEN

We report the construction of a large nonimmunized human phage antibody library in single-chain variable region fragment (scFv) format, which allowed the selection of antibodies that neutralize hepatitis B virus (HBV) in vitro. We generated 1.1 x 10(10) independent scFv clones using the cDNA of functional variable (V) gene segments of heavy and light chains purified from the peripheral blood mononuclear cells of 50 nonimmunized human donors. Using BIAcore, we selected two clones that recognized pre-S1 and neutralized pre-S1 and HBV binding to Chang liver cells. Clone G10 had the highest affinity (K(D)=1.69 x 10(-7)M), which was higher than that of clone 1E4 that was generated previously from a heavy chain-shuffled immune library. The off-rates of clones were within 10(-3)s(-1) as determined by BIAcore and were comparable to those of antibodies derived from a normal secondary immune response. In the inhibition assays of pre-S1 and virus binding to Chang liver cells using flow cytometry and the polymerase chain reaction, G10 had better neutralizing activity than 1E4. The new phage library may be a valuable source of antibodies with reasonable affinities to different targets, and the anti-pre-S1 G10 may be a good candidate for immunoprophylaxis against HBV infection.


Asunto(s)
Anticuerpos contra la Hepatitis B/biosíntesis , Antígenos de Superficie de la Hepatitis B/inmunología , Virus de la Hepatitis B/inmunología , Fragmentos Fab de Inmunoglobulinas/genética , Biblioteca de Péptidos , Precursores de Proteínas/inmunología , Bacteriófagos , Línea Celular , Anticuerpos contra la Hepatitis B/inmunología , Humanos , Fragmentos Fab de Inmunoglobulinas/química , Fragmentos de Inmunoglobulinas/química , Fragmentos de Inmunoglobulinas/genética , Región Variable de Inmunoglobulina/genética
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