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1.
Nanotechnology ; 33(20)2022 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-35078166

RESUMEN

Metal-organic frames (MOFs) are regarded as excellent candidates for supercapacitors that have attracted much attention because of their diversity, adjustability and porosity. However, both poor structural stability in aqueous alkaline electrolytes and the low electrical conductivity of MOF materials constrain their practical implementation in supercapacitors. In this study, bimetallic CoNi-MOF were synthesized to enhance the electrical conductivity and electrochemical activity of nickel-based MOF, as well as the electrochemical performance of the CoNi-MOF in multiple alkaline electrolytes was investigated. The CoNi-MOF/active carbon device, as-fabricated with a 1 M KOH electrolyte, possesses a high energy density of 35 W h kg-1with a power density of 1450 W kg-1, exhibiting outstanding cycling stability of 95% over 10,000 cycles. The design of MOF-based electrode materials and the optimization selection of electrolytes pave the way for constructing high-performance supercapacitors.

2.
Gynecol Endocrinol ; 36(4): 303-307, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31718336

RESUMEN

Approximately, 5% of ovarian tumors have hormonal activity. Steroid cell tumors (SCTs) represent about 0.1% of all ovarian tumors. They cause hyperandrogenism associated with typical virilization. In this case report, we present 45-year-old women with unmalignant ovarian SCT-producing androgens which cause severe virilization and secondary amenorrhea lasting two years. Transvaginal ultrasound, computed tomography of adrenal glands, magnetic resonance imaging of small pelvis, laboratory tests (including serum concentration of FSH, LH, testosterone (T), androstenedione (A), dehydroepiandrosterone sulfate (DHEA-S), as well as ROMA index) were performed. During hormonal evaluation, elevated concentrations of serum T - on admission 1.72 ng/ml and one month later 3.75 ng/ml (normal range 0.08-0.82 ng/ml) and A - 24.90 ng/ml (normal range 0.40-3.40 ng/ml) were found. The ROMA index was within the normal range. Enlargement of the left ovary by solid mass 56 × 43 mm was found during ultrasound examination. Based on small pelvis MRI scan and hormonal finding, patient was qualified for laparotomy. During this procedure, the left salpingo-oophorectomy with removal of the tumor was performed. The histopathological examination identified SCT. During follow-up examination, one day after surgery, we found serum testosterone levels within normal ranges - 0.74 ng/ml (normal range 0.08-0.82 ng/ml). This case shows that hormone-producing ovarian tumors are rare but very important clinical causes of severe hyperandrogenism.


Asunto(s)
Hiperandrogenismo/etiología , Neoplasias Ováricas/complicaciones , Tumores de los Cordones Sexuales y Estroma de las Gónadas/complicaciones , Femenino , Humanos , Hiperandrogenismo/diagnóstico , Hiperandrogenismo/patología , Hiperandrogenismo/cirugía , Persona de Mediana Edad , Neoplasias Ováricas/diagnóstico , Neoplasias Ováricas/cirugía , Índice de Severidad de la Enfermedad , Tumores de los Cordones Sexuales y Estroma de las Gónadas/diagnóstico , Tumores de los Cordones Sexuales y Estroma de las Gónadas/cirugía
3.
Gynecol Endocrinol ; 33(11): 836-839, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28604129

RESUMEN

Ovarian hyperthecosis (OH) is characterized by the presence of abundant luteinized theca cells in ovaries that secret androgen. It typically presents as severe hyperandrogenism and/or virilization in postmenopausal woman. Here we describe a 66-year old woman with presentation of severe hirsutism, alopecia, clitoromegaly and laboratory finding of significantly elevated serum total testosterone concentration and hyperinsulinemia. Performed imaging studies revealed normal sized, homogeneous ovaries, signs of endometrial hypertrophy and normal adrenal glands. Due to severe hyperandrogenemia and signs of endometrial hypertrophy, the total abdominal hysterectomy with bilateral salpingo-oophorectomy has been performed. Pathological examination revealed OH and endometrial hyperplasia. Androgenic activity of ovarian stromal cells has been confirmed using alpha-inhibin histochemical staining. Postmenopausal hyperandrogenemia is a diagnostic and therapeutic challenge and the imaging studies often may be misleading and require careful and critical consideration.


Asunto(s)
Hiperandrogenismo/etiología , Enfermedades del Ovario/complicaciones , Anciano , Femenino , Humanos
4.
Ginekol Pol ; 87(2): 148-52, 2016.
Artículo en Inglés, Polaco | MEDLINE | ID: mdl-27306293

RESUMEN

This study describes the ultrasound diagnostic process and management in a patient with a unique, rare form of fibroids, i.e. the atypical variant. According to the WHO definition, an atypical uterine myoma cannot be histologically unambiguously diagnosed as benign or malignant. Atypical leiomyomas are characterized by moderate or high quantity of pleomorphic atypical tumor cells, with a small number of mitotic divisions and lack of coagulative necrosis in the tumor. They have a low rate of extrauterine, intraabdominal recurrence, with a negligible risk for distant metastases. Due to the fact the atypical variant of leiomyomas is very rare, it presents a significant diagnostic challenge for obstetricians. The most reliable diagnosis can be made only on the basis of the histopathological examination. In this paper, we present a case of a patient in whom an echo with the diameter of 92 mm and a heterogeneous echogenicity with visible anechoic fields were discovered in the uterine fundus. HD color Doppler demonstrated high vascularization within the tumor, peripherally as well as centrally. The peripheral and central vascularization was rated at 4/4 points on a scale by Exacoustos. The tumor in the uterus met the criteria of high probability of malignancy i.e. 8 points on the vascular scale (power Doppler scale ≥ 7 pts.), solid tumor and a size over 8 cm. Blood flow velocity and vascular resistance in the tumor vessels were evaluated (PSV - 5.76 cm/s, ED - 3.16 cm/s, RI - 0.45 S / D - 1.82). Blood flow in the tumor presented low resistance. Hysterectomy without oophorectomy, with an intraoperative histopathological examination, was performed, and a fibroid was confirmed. The tumor was soft, yellow, with small and medium level of dispersed atypia in microscopic examination. There was no necrosis or mitotic figures. The histopathological image confirmed the atypical leiomyoma of low risk of recurrence. Atypical fibroids are rare in gynecological oncology and they do not have the characteristic clinical course. Furthermore, they do not show the typical characteristics during imaging studies, including ultrasound screening, Sometimes, due to the sonographic image, they should be differentiated from sarcomas. Also, it is necessary to exclude malignancy because of their ambiguous histological characteristics.


Asunto(s)
Leiomioma/diagnóstico por imagen , Neoplasias Uterinas/diagnóstico por imagen , Útero/patología , Diagnóstico Diferencial , Femenino , Humanos , Histerectomía , Leiomioma/patología , Persona de Mediana Edad , Tumor de Músculo Liso/diagnóstico por imagen , Resultado del Tratamiento , Ultrasonografía , Neoplasias Uterinas/cirugía
5.
Ginekol Pol ; 86(2): 88-93, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25807831

RESUMEN

OBJECTIVES: The aim of this study was to assess the sensitivity and specificity of HE4 in detecting and differentiating between types I and II epithelial ovarian cancer (EOC) in comparison with CA125. MATERIAL AND METHODS: We measured HE4 and CA125 serum concentrations in 206 samples taken from patients operated in Gynecologic Oncology Department due to ovarian tumors. Ovarian cancer was confirmed in 89 cases divided into type I and type II. 52 healthy patients without any gynecological disease formed the control group. The sensitivity and specificity for type I and type II EOC detection and differentiating between both types was evaluated for HE4 and CA125. RESULTS: The HE4 and CA125 serum concentrations were significantly higher in type II than in type I EOC (p=0.008696, p=0.000243 respectively). The HE4 and CA125 sensitivity for type I and benign tumors differentiation was 63.16% for both of them and specificity was 87.29% vs 67.89% respectively. For CA125 these differences did not reach statistical significance. The HE4 sensitivity and specificity for type II and benign tumors differentiation were 87.14% and 96.61%, respectively and for CA125 these values were 82.86% and 94.07%, respectively. CONCLUSIONS: Pretreatment analysis of HE4 serum concentration is superior to CA125 in differential diagnosis of ovarian cancer subtypes (I and II). HE4 is superior to CA125 in detecting ovarian cancer type II. Neither HE4 nor CA125 is an effective diagnostic tool for type I ovarian cancer detection. A new highly specific and highly sensitive tumor marker for type I EOC is needed.


Asunto(s)
Biomarcadores de Tumor/sangre , Antígeno Ca-125/sangre , Neoplasias Glandulares y Epiteliales/sangre , Neoplasias Glandulares y Epiteliales/diagnóstico , Neoplasias Ováricas/sangre , Neoplasias Ováricas/diagnóstico , Proteínas/análisis , Adulto , Carcinoma Epitelial de Ovario , Diagnóstico Diferencial , Femenino , Humanos , Persona de Mediana Edad , Neoplasias Glandulares y Epiteliales/patología , Quistes Ováricos/sangre , Neoplasias Ováricas/patología , Polonia , Curva ROC , Factores de Riesgo , Proteína 2 de Dominio del Núcleo de Cuatro Disulfuros WAP , Salud de la Mujer
6.
Beilstein J Nanotechnol ; 15: 57-70, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38229679

RESUMEN

In this work, a strategy for one-stage synthesis of polymer composites based on PNIPAAm hydrogel was presented. Both conductive particles in the form of conductive carbon black (cCB) and MnCo2O4 (MCO) spinel particles were suspended in the three-dimensional structure of the hydrogel. The MCO particles in the resulting hydrogel composite acted as an electrocatalyst in the oxygen evolution reaction. Morphological studies confirmed that the added particles were incorporated and, in the case of a higher concentration of cCB particles, also bound to the surface of the structure of the hydrogel matrix. The produced composite materials were tested in terms of their electrical properties, showing that an increase in the concentration of conductive particles in the hydrogel structure translates into a lowering of the impedance modulus and an increase in the double-layer capacitance of the electrode. This, in turn, resulted in a higher catalytic activity of the electrode in the oxygen evolution reaction. The use of a hydrogel as a matrix to suspend the catalyst particles, and thus increase their availability through the electrolyte, seems to be an interesting and promising application approach.

7.
Energy Fuels ; 38(2): 1330-1336, 2024 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-38264624

RESUMEN

MnCo1.5Fe0.5O4 spinel oxide was synthesized using the sol-gel technique, followed by heat treatment at various temperatures (400, 600, 800, and 1000 °C). The prepared materials were examined as anode electrocatalysts for water-splitting systems in alkaline environments. Solid-state characterization methods, such as powder X-ray diffraction and X-ray absorption spectroscopy (XAS), were used to analyze the materials' crystallographic structure and surface characteristics. The intrinsic activity of the MnCo1.5Fe0.5O4 was fine-tuned by altering the electronic structure by controlling the calcination temperature, and the highest activity was observed for the sample treated at 800 °C. A shift in the valence state of surface cations under oxidative conditions in an alkaline solution during the oxygen evolution reaction was detected through ex situ XAS measurements. Moreover, the influence of the experimental conditions on the electrocatalytic performance of the material, including the pH of the electrolyte and the temperature, was demonstrated.

8.
Beilstein J Nanotechnol ; 14: 420-433, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37025365

RESUMEN

In this work, the specific role of the addition of graphene oxide (GO) to state-of-the-art nickel-iron (NiFe) and cobalt-nickel-iron (CoNiFe) mixed oxides/hydroxides towards the oxygen evolution reaction (OER) is investigated. Morphology, structure, and OER catalytic activity of the catalysts with and without GO were studied. The catalysts were fabricated via a two-step electrodeposition. The first step included the deposition of GO flakes, which, in the second step, were reduced during the simultaneous deposition of NiFe or CoNiFe. As a result, NiFe-GO and CoNiFe-GO were fabricated without any additives directly on the nickel foam substrate. A significant improvement of the OER activity was observed after combining NiFe with GO (OER overpotential η(10 mA·cm-2): 210 mV) compared to NiFe (η: 235 mV) and GO (η: 320 mV) alone. A different OER activity was observed for CoNiFe-GO. Here, the overall catalytic activity (η: 230 mV) increased compared to GO alone. However, it was reduced in comparison to CoNiFe (η: 224 mV). The latter was associated with the change in the morphology and structure of the catalysts. Further OER studies showed that each of the catalysts specifically influenced the process. The improvement in the OER by NiFe-GO results mainly from the structure of NiFe and the electroactive surface area of GO.

9.
ACS Appl Mater Interfaces ; 14(51): 57449-57459, 2022 Dec 28.
Artículo en Inglés | MEDLINE | ID: mdl-36520672

RESUMEN

Further development of solid oxide fuel cell (SOFC) oxygen electrodes can be achieved through improvements in oxygen electrode design by microstructure miniaturization alongside nanomaterial implementation. In this work, improved electrochemical performance of an La0.6Sr0.4Co0.2Fe0.8O3-d (LSCF) cathode was achieved by the controlled modification of the La0.6Sr0.4CoO3-d (LSC) nanocrystalline interlayer introduced between a porous oxygen electrode and dense electrolyte. The evaluation was carried out for various LSC layer thicknesses, annealing temperatures, oxygen partial pressures, and temperatures as well as subjected to long-term stability tests and evaluated in typical operating conditions in an intermediate temperature SOFC. Electrochemical impedance spectroscopy and a distribution of relaxation times analysis were performed to reveal the rate-limiting electrochemical processes that limit the overall electrode performance. The main processes with an impact on the electrode performance were the adsorption of gaseous oxygen O2, dissociation of O2, and charge transfer-diffusion (O2-). The introduction of a nanoporous and nanocrystalline interlayer with extended electrochemically active surface area accelerates the oxygen surface exchange kinetics and oxygen ion diffusions, reducing polarization resistances. The polarization resistance of the reference LSCF was lowered by one order of magnitude from 0.77 to 0.076 Ω·cm2 at 600 °C by the deposition of a 400 nm LSC interlayer at the interface. The developed electrode tested in the anode-supported fuel cell configuration showed a higher cell performance by 20% compared to the cell with the reference electrode. The maximum power density at 700 °C reaches 675 and 820 mW·cm-2 for the reference cell and the cell with the LSC interlayer, respectively. Aging tests at 700 °C under a high load of 1 A·cm2 were performed.

10.
Adv Biol (Weinh) ; 6(12): e2200197, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36084257

RESUMEN

Ovarian carcinoma (OC) forms outgrowths that extend from the outer surface of an afflicted organ into the peritoneum. OC outgrowth formation is poorly understood due to the limited availability of cell culture models examining the behavior of cells that form outgrowths. Prompted by immunochemical evaluation of extracellular matrix (ECM) components in human tissues, laminin and collagen-rich ECM-reconstituted cell culture models amenable to studies of cell clusters that can form outgrowths are developed. It is demonstrated that ECM promotes outgrowth formation in fallopian tube non-ciliated epithelial cells (FNE) expressing mutant p53 and various OC cell lines. Outgrowths are initiated by cells that underwent outward translocation and retained the ability to intercalate into mesothelial cell monolayers. Electron microscopy, optical coherence tomography, and small amplitude oscillatory shear experiments reveal that increased ECM levels led to increased fibrous network thickness and high shear elasticity of the microenvironment. These physical characteristics are associated with outgrowth suppression. The low ECM microenvironment mimicks the viscoelasticity of malignant peritoneal fluid (ascites) and supports cell proliferation, cell translocation, and outgrowth formation. These results highlight the importance of the ECM microenvironment in modulating OC growth and can provide additional insights into the mode of dissemination of primary and recurrent ovarian tumors.


Asunto(s)
Carcinoma , Neoplasias Ováricas , Humanos , Femenino , Recurrencia Local de Neoplasia/metabolismo , Matriz Extracelular/metabolismo , Neoplasias Ováricas/genética , Carcinoma Epitelial de Ovario/metabolismo , Laminina/genética , Carcinoma/metabolismo , Microambiente Tumoral
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