Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Asian J Transfus Sci ; 16(2): 251-256, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36687532

RESUMO

BACKGROUND: Most of the red blood cell (RBC) storage lesions can be attributed to oxidative stress encountered by the RBCs throughout the duration of their storage. Various donor variables at the time of donation may be responsible for the total antioxidant capacity of the supernatant and thus, the "storability" and the magnitude of development of these RBC storage lesions. It is known that uric acid (UA) is responsible for more than 60% of the TAC of the blood. This study aims to explore the relationship between donor UA levels and the difference in percentage hemolysis, an important RBC storage lesion, on day 1 and day 21, in stored packed RBCs (PRBCs) units. MATERIALS AND METHODS: The serum UA of 100 healthy voluntary male blood donors was estimated at the time of blood donation. The percentage hemolysis in the supernatant of the leukoreduced citrate phosphate dextrose/saline-adenine-glucose-mannitol RBC units (n = 100) prepared from these donors was calculated on day 1 and day 21. The difference in percentage hemolysis between donors with high normal serum UA levels (>7 mg/dL) was compared to that of the donors with low normal serum UA levels (<5 mg/dL) to observe the effect of donor UA levels on the difference in percentage hemolysis. RESULTS: The mean of the differences in percentage hemolysis in the supernatant in low UA group (<5 mg/dL) was higher than the mean of the differences in percentage hemolysis in the supernatant in high UA group (>7 mg/dL) and this was statistically significant (P < 0.001). The donor serum UA level and difference in percentage hemolysis on day 21 and day 1 were found to be negatively co-related. CONCLUSION: Higher levels of serum UA of blood donors seem to have a protective effect on the stored PRBC units as shown in this study. Hence, the potential of UA as one of the constituents of RBC additive solutions might lead to the enhancement of the quality of stored PRBC units by decreasing the RBC storage lesions.

2.
J Lab Physicians ; 13(4): 362-367, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34975257

RESUMO

Overview Mesenchymal tumors of the breast are rare. Few epithelial tumors also have mesenchymal components. It is crucial to identify these as per histogenesis. This can be facilitated by markers of epithelial-mesenchymal transition (EMT). Objectives The aim of this study was to categorize the breast lesions with mesenchymal morphology and to study EMT on immunohistochemistry (IHC). Materials and Methods This is a retrospective study of 5-year duration from January 2015 to December 2019. Inclusion criteria: all breast lesions showing mesenchymal/nonepithelial morphology, complete or partial, on histology. Exclusion criteria: Mammary carcinomas without any mesenchymal/nonepithelial morphology, fibroadenomas, and lymphomas. Demographics, clinical, gross examination, histology, and IHC findings of selected cases were reviewed and recorded. Three additional markers p53, E-cadherin, and ß-catenin were performed. Statistical Analysis Used Frequency calculation for each variable (IHC). Results Thirteen (2.5%) out of total 510 breast specimens showed mesenchymal histology. Of these, five (38.5%) were metaplastic breast carcinomas (MBC), four (31%) were phyllodes tumor (PT), and one (7.7%) case each of malignant peripheral nerve sheath tumor, primary stromal sarcoma of breast, pseudoangiomatous stromal hyperplasia, and myofibroblastoma. Loss of E-cadherin was seen in 4/5 (80%) MBCs and was retained in ductal component of PTs. p53 was not expressed in any of the tumors except 3/5 (60%) MBCs. ß-Catenin was aberrant in all MBCs. Conclusions Primary breast tumors with mesenchymal morphology present a spectrum ranging from benign mesenchymal, fibroepithelial neoplasms to malignant tumors of mesenchymal and epithelial origin. Loss of E-cadherin, expression of p53, and aberrant expression of ß-catenin are suggestive of EMT and molecular heterogeneity of MBCs.

3.
Hum Immunol ; 79(3): 160-165, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29330111

RESUMO

BACKGROUND: Since soluble isoforms of MICA play an important role in modulating the immune response, we evaluated a possible correlation between their levels and development of acute rejection following renal transplantation. METHODS: Serum samples collected at pre- and different time points post-transplant from 137 live related donor renal transplant recipients were evaluated retrospectively for sMICA levels and for the presence of MICA antibodies. Samples from 30 healthy volunteers were also tested as controls. RESULTS: Significantly higher levels of sMICA were observed in the pretransplant sera of allograft recipients as compared to healthy controls. Patients with acute cellular rejection experienced a significant fall in their levels at the time of diagnosis as compared to their pretransplant values and posttransplant follow up time points (p = .01, .003, .005 and .04 respectively at pre vs biopsy (Bx), POD7 vs Bx, POD 30 vs Bx, POD 90 vs Bx). However, no such difference was noted in patients undergoing antibody mediated rejection. Further the study did not reveal any correlation on the presence/absence of MICA antibodies with either an increase or decrease in sMICA levels. CONCLUSIONS: Estimating circulating levels of soluble MICA could provide useful information of prognostic importance in assessing graft outcome following renal transplantation.


Assuntos
Antígenos de Histocompatibilidade Classe I/imunologia , Isoanticorpos/sangue , Transplante de Rim , Doença Aguda , Adulto , Feminino , Seguimentos , Rejeição de Enxerto , Voluntários Saudáveis , Antígenos de Histocompatibilidade Classe I/sangue , Humanos , Imunomodulação , Masculino , Estudos Retrospectivos , Transplante Homólogo
4.
Nano Converg ; 4(1): 18, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28804699

RESUMO

We confirmed the influence of ZnO nanoparticle size and residual water on performance of all inorganic perovskite solar cells. By decreasing the size of the ZnO nanoparticles, the short-circuit current density (Jsc) and open circuit photovoltage (Voc) values are increased and the conversion efficiency is improved. Although the Voc value is not affected by the influence of residual water in the solution for preparing the ZnO layer, the Jsc value drops greatly. As a result, it was found that it is important to use the oxide nanoparticles with a small particle diameter and to reduce the water content in the oxide forming material in order to manufacture a highly efficient all inorganic perovskite solar cells.

5.
Nanoscale ; 9(17): 5475-5482, 2017 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-28426040

RESUMO

In this article, we demonstrate for the first time a mesoscopic printable perovskite solar cell (PSC) using NiO as the hole transporting material and low-temperature processed carbon as the counter electrode. A single deposition method assisted by N2 blow drying was used for the deposition of MAPbI3 on a TiO2/ZrO2/NiO screen-printed electrode. As the final step a low-temperature processing (i.e. 75 °C) carbon counter layer was fabricated on MAPbI3 by a blade coating method. It is found that the capping layer thickness of MAPbI3 has a significant effect on the device efficiency, especially when NiO is introduced as a hole transporting material into the structure. Electrochemical impedance spectroscopy demonstrates good charge transport characteristics for the device with a thin MAPbI3 capping layer obtained by the N2 blow drying method. Our best performing device demonstrated a remarkable photovoltaic performance with a short-circuit current density (Jsc) of 22.38 mA cm-2, an open circuit voltage (Voc) of 0.97 V, and a fill factor (FF) of 0.50 corresponding to a photo-conversion efficiency (PCE) of 10.83%. Moreover, the un-encapsulated device exhibited advantageous stability over 1000 h in air in the dark.

6.
ChemSusChem ; 9(18): 2604-2608, 2016 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-27629068

RESUMO

Many efforts have been made towards improving perovskite (PVK) solar cell stability, but their thermal stability, particularly at 85 °C (IEC 61646 climate chamber tests), remains a challenge. Outdoors, the installed solar cell temperature can reach up to 85 °C, especially in desert regions, providing sufficient motivation to study the effect of temperature stress at or above this temperature (e.g., 100 °C) to confirm the commercial viability of PVK solar cells for industrial companies. In this work, a three-layer printable HTM-free CH3 NH3 PbI3 PVK solar cell with a mesoporous carbon back contact and UV-curable sealant was fabricated and tested for thermal stability over 1500 h at 100 °C. Interestingly, the position of the UV-curing glue was found to drastically affect the device stability. The side-sealed cells show high PCE stability and represent a large step toward commercialization of next generation organic-inorganic lead halide PVK solar cells.


Assuntos
Compostos de Cálcio/química , Carbono/química , Fontes de Energia Elétrica , Óxidos/química , Impressão , Energia Solar , Temperatura , Titânio/química , Estabilidade de Medicamentos , Eletrodos , Porosidade
7.
Phys Chem Chem Phys ; 18(22): 14970-5, 2016 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-27194000

RESUMO

In this work, a new current peak at forward bias in the dark current-voltage curves has been identified for standard mesoscopic perovskite solar cells. This characteristic peak appears only under some specific conditions, mainly in the reverse scan (RS) direction and when the solar cells were kept for several seconds under short-circuit conditions before starting the RS measurement. This peak disappears when the above experimental conditions are not applied. It is considered that this uncommon diode shape is obtained because shallow and/or deep trap states located at the interface between either perovskite/p-type or perovskite/n-type transport materials are dynamically filled during the RS voltage scan. To corroborate this hypothesis, the response of hole transport materials (HTMs), small molecule spiro-OMeTAD and polymer P3HT, as well as both HTMs with additives, was compared. Also perovskite absorbers such as CH3NH3PbI3 and all-inorganic perovskite based on cesium (CsPbI3) were also analyzed, achieving in all cases similar trends.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA