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










Base de dados
Intervalo de ano de publicação
1.
Sensors (Basel) ; 24(13)2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-39000908

RESUMO

Next-generation communication systems demand the integration of sensing, communication, and power transfer (PT) capabilities, requiring high spectral efficiency, energy efficiency, and low cost while also necessitating robustness in high-speed scenarios. Integrated sensing and communication systems (ISACSs) exhibit the ability to simultaneously perform communication and sensing tasks using a single RF signal, while simultaneous wireless information and power transfer (SWIPT) systems can handle simultaneous information and energy transmission, and orthogonal time frequency space (OTFS) signals are adept at handling high Doppler scenarios. Combining the advantages of these three technologies, a novel cyclic prefix (CP) OTFS-based integrated simultaneous wireless sensing, communication, and power transfer system (ISWSCPTS) framework is proposed in this work. Within the ISWSCPTS, the CP-OTFS matched filter (MF)-based target detection and parameter estimation (MF-TDaPE) algorithm is proposed to endow the system with sensing capabilities. To enhance the system's sensing capability, a waveform design algorithm based on CP-OTFS ambiguity function shaping (AFS) is proposed, which is solved by an iterative method. Furthermore, to maximize the system's sensing performance under communication and PT quality of service (QoS) constraints, a semidefinite relaxation (SDR) beamforming design (SDR-BD) algorithm is proposed, which is solved using through the SDR technique. The simulation results demonstrate that the ISWSCPTS exhibits stronger parameter estimation performance in high-speed scenarios compared to orthogonal frequency division multiplexing (OFDM), the waveform designed by CP-OTFS AFS demonstrates superior interference resilience, and the beamforming designed by SDR-BD strikes a balance in the overall performance of the ISWSCPTS.

2.
Medicine (Baltimore) ; 97(37): e12164, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30212943

RESUMO

BACKGROUND: We aimed to estimate the association between dietary carrot intake and risk of breast cancer by conducting a meta-analysis of epidemiologic studies. METHODS: Relevant studies were identified by searching databases through September 2017. We included studies that reported risk estimates with 95% confidence intervals for the association between dietary carrot intake and breast cancer risk. Random-effects models were used to calculate the summary risk estimates. Publication bias was estimated using Begg's funnel plot and Egger's regression asymmetry test. RESULTS: A total of 10 articles met the eligibility criteria and were included in the meta-analysis involving 13,747 cases. The combined odds ratios (ORs) of breast cancer for the highest compared with the lowest dietary carrot intake was 0.79 (95% CI: 0.68, 0.90), and a significant heterogeneity was observed. In the subgroup analyses separated by study design, the inverse associations were more pronounced in the case-control studies than in the cohort studies, while the associations did not significantly differ by geographical region, study quality, exposure assessment. Omission of any single study had little effect on the combined risk estimate. CONCLUSION: The overall current literatures suggested that dietary carrot intake was associated with decreased risk of breast cancer.


Assuntos
Neoplasias da Mama/epidemiologia , Daucus carota , Estudos Epidemiológicos , Humanos , Razão de Chances , Fatores de Risco
3.
Gene ; 664: 50-57, 2018 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-29678660

RESUMO

The aim of present study was to examine whether metformin in association with quercetin has any synergistically anti-tumor effects on prostate cancer. Our findings showed that metformin in combination with quercetin synergistically inhibited the growth, migration and invasion of both PC-3 and LNCaP cells. Co-treatment of these two agents induced more apoptosis than single agent treatment. The co-treatment-induced apoptosis was caspase-dependent and accompanied by the down-regulation of Bcl-2 family members. Our data also indicated that co-treatment of metformin and quercetin strongly inhibited the VEGF/Akt/PI3K pathway. Moreover, these two agents acted synergistically to repress the growth of human prostate cancer cell xenograft in vivo in nude mice. In conclusion, our findings indicate that the combination therapy of metformin and quercetin exerted synergistic antitumor effects in prostate cancers via inhibition of VEGF/Akt/PI3K pathway. Thus, combination treatment of metformin and quercetin would be a promising therapeutic strategy for prostate cancer patients.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Apoptose/efeitos dos fármacos , Neoplasias da Próstata/tratamento farmacológico , Transdução de Sinais/efeitos dos fármacos , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Caspases/metabolismo , Linhagem Celular Tumoral , Regulação para Baixo , Sinergismo Farmacológico , Humanos , Masculino , Metformina/farmacologia , Metformina/uso terapêutico , Camundongos , Camundongos Nus , Fosfatidilinositol 3-Quinases/metabolismo , Neoplasias da Próstata/patologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Quercetina/farmacologia , Quercetina/uso terapêutico , Fator A de Crescimento do Endotélio Vascular/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
4.
Int J Clin Exp Med ; 8(10): 19670-81, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26770631

RESUMO

The objective of this work is to prepare and evaluate Poly (D, L-Lactide-co-glycolide) (PLGA) Nanoparticles (NPs) of Capecitabine, an anticancer agent loaded by solvent displacement method using stabilizer (poly vinyl alcohol). The prepared NPs were characterized by FT-IR, DSC, drug loading, entrapment efficiency, particle size, surface morphology by Atomic force microscopy (AFM), X-ray diffraction and in-vitro studies. FT-IR and DSC studies indicated that there was no interaction between the drug and polymer. The morphological studies performed by AFM showed uniform and spherical shaped discrete particles without aggregation and smooth in surface morphology with a nano size range of 144 nm. X-ray diffraction was performed to reveal the crystalline nature of the drug after encapsulation. The NPs formed were spherical in shape with zeta potentials (-14.8 mV). In vitro release studies were carried and showed drug release up to 5 days. The drug release followed zero order kinetics and a Fickian transport mechanism. Nanoparticles obtained a high encapsulation efficiency of 88.4% and drug loading of 16.98%. Drug released from Capecitabine loaded PLGA NPs (84.1%) was for 5 days. It is concluded from the present investigation that PLGA NPs of Capecitabine may effectively deliver the drug to the prostate for the treatment of prostate cancer.

5.
World J Surg Oncol ; 9: 107, 2011 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-21929755

RESUMO

BACKGROUND: The association between fish consumption and risk of bladder cancer has not been established yet. The results from epidemiological studies are inconsistent. METHODS: We conducted a meta-analysis of cohort and case-control studies on the relationship between fish intake and bladder cancer. We quantified associations with bladder cancer using meta-analysis of relative risk associated to the highest versus the lowest category of fish intake using random effect models. Heterogeneity among studies was examined using Q and I2 statistics. Publication bias was assessed using the Begg's funnel plot. RESULTS: Five cohort and 9 case-control studies were eligible for inclusion. The combined relative risk showed that fish consumption was negatively, but not significantly, associated with a decreased risk of bladder cancer (relative risk, 0.86; 95% confidence interval, 0.61-1.12). In subgroup analyses, there was no evidence that study design, geographical region, case sample size, or exposure assessment substantially influenced the estimate of effects. CONCLUSION: The overall current literature on fish consumption and the risk of bladder cancer suggested no association. Because of the limited number of studies, further well-designed prospective studies are needed to explore the effect of fish on bladder cancer.


Assuntos
Comportamento Alimentar , Peixes , Medição de Risco/métodos , Neoplasias da Bexiga Urinária , Animais , Humanos , Morbidade , Fatores de Risco , Neoplasias da Bexiga Urinária/epidemiologia , Neoplasias da Bexiga Urinária/etiologia , Neoplasias da Bexiga Urinária/prevenção & controle
6.
Environ Int ; 31(6): 822-8, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15992927

RESUMO

Soil contamination with polycyclic aromatic hydrocarbons (PAHs) is an increasing problem in many countries, including China. An extensive and systematic survey has been undertaken to evaluate the contamination with PAHs of urban soils in Beijing, China. Soil samples were collected from campuses of universities, schools and kindergartens, public squares, fallow land and roadsides, and were analyzed for 16 PAHs by GC-MS. There was a high variability in the total PAHs (SigmaPAHs) concentrations, ranging from less than 366 to 27,825 ng g(-1). The highest SigmaPAHs concentrations were found at roadsides and industrial sites. Soil organic carbon (SOC) is one of the important factors that can influence the concentrations of PAHs in soils. It was found that concentrations of SigmaPAHs were significantly correlated with that of soil organic carbon. To trace the sources of PAHs, the ratios of phenanthrene to anthracene and fluoranthene to pyrene were used to identify pyrogenic and petrogenic sources, respectively. In most cases, PAHs in soils in urban areas of Beijing were pyrogenic. These sources included motor vehicle exhausts, industrial activities and coal burning. These data can be further used to assess the health risk associated with soils polluted with PAHs.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes do Solo/análise , Carbono/análise , China , Cidades , Monitoramento Ambiental , Combustíveis Fósseis
7.
Huan Jing Ke Xue ; 24(1): 8-15, 2003 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-12708283

RESUMO

Non-methane hydrocarbon (NMHC) emission from plants significantly affects the atmospheric environment change. Isoprene is the main NMHC in the troposphere. With the light-temperature model put forward by Guenther, isoprene emission from Chinese forest ecosystem was estimated. The result showed that the total isoprene emission was 0.03-8.6 Tg/a and release 0.026-7.589 TgC/a, which is 1.5%-4.3% of the global one. Isoprene emission has largely spatial variation, and the higher emissions occur in Southern and Northeast parts of China, where large forests are distributed. Yunnan and Heilongjiang are two higher emission provinces of China, and their contributions to the total are about 22% and 11%. The contribution varied with different species. The emissions from poplar and oak forests contribute 52.28% and 44.29% of the total, respectively.


Assuntos
Butadienos/metabolismo , Ecossistema , Hemiterpenos , Pentanos , Árvores/metabolismo , Meio Ambiente
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...