Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Sensors (Basel) ; 23(7)2023 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-37050720

RESUMO

It has been recently shown that zero padding (ZP)-orthogonal frequency-division multiplexing (OFDM) is a promising candidate for 6G wireless systems requiring joint communication and sensing. In this paper, we consider a multiuser uplink scenario where users are separated in power domain, i.e., non-orthogonal multiple access (NOMA), and use ZP-OFDM signals. The uplink transmission is grant-free and users are allowed to transmit asynchronously. In this setup, we address the problem of time synchronization by estimating the timing offset (TO) of all the users. We propose two non-data-aided (NDA) estimators, i.e., the joint method of moment (JMoM) and the successive moment cancellation (SMC), that employ the periodicity of the second order moment (SoM) of the received samples for TO estimation. Moreover, the coding assisted (CA) version of the proposed estimators, i.e., CA-JMoM and CA-SMC, are developed for the case of short observation samples. We also extend the proposed estimators to multiuser multiple-input multiple-output (MIMO) systems. The effectiveness of the proposed estimators is evaluated in terms of lock-in probability under various practical scenarios. Simulation results show that the JMoM estimator can reach the lock-in probability of one for the moderate range of Eb/N0 values. While existing NDA TO estimators in the literature either offer low lock-in probability, high computational complexity that prevents them from being employed in MIMO systems, or are designed for single-user scenarios, the proposed estimators in this paper address all of these issues.

2.
Vet Res Forum ; 13(2): 257-263, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35919850

RESUMO

The aim of this study was to evaluate the correlation between some fetal parameters measured by ultrasonography and fetal age for developing a formula which could be used for estimation of fetal age in Baluchi sheep. Placentome diameter (PD), gestation Sac diameter (GSD), biparietal diameter (BPD), straight crown-rump length (CRL), femural length (FL), occipito-snout diameter (OSD), thoracic diameter (TD) and fetal heart rate (FHR) were measured by transrectal and/or transabdominal ultrasonography. All ewes were synchronized using progesterone sponge for 6 days. On the first day, they received PGF2 and on the last day received 400 IU of equine serum gonadotrophin (eCG). All of the parameters revealed significant correlation by increasing fetal age. Except for PD, for other values linear regression curve was illustrated. BPD (between 36 - 96 days) (R2 = 0.961), CRL (R2 = 0.935), FL (R2 = 0.950), OSD (R2 = 0.981), TD (R2 = 0.975) showed high correlation with fetal age (p < 0.001). Moderate correlation was calculated for FHR (p < 0.001, R2 = 0.883). Low correlations were assessed by measurement of GSD (p = 0.018, R2 = 0.318), BPD (between 96-138 days; p = 0.038, R2 = 0.29) and PD represented the significant non-linear correlation with age (p < 0.001), maximum correlation was assessed by measurement of mean placentome wall diameter. In conclusion, OSD was recommended as the best parameter for estimating of gestational age between days 36 - 109 in Baluchi sheep because of the lowest residuals, the highest correlation coefficient and wide period of availability for imaging in gestation.

3.
Ethiop J Health Sci ; 30(3): 397-408, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32874083

RESUMO

BACKGROUND: Blood transfusion is a life-saving procedure; millions of lives are saved each year. However, blood transfusions are associated with certain risks that can lead to adverse consequences. This study aimed to survey the prevalence and trend of hepatitis B virus (HBV), hepatitis C virus (HCV), and Human immunodeficiency virus (HIV) among blood donors of Fars province, Iran (2006-2018). METHODS: This retrospective cross-sectional study was conducted by reviewing the records of the blood transfusion organization of Fars province. A total of 1952478 blood units were screened for transfusion-transmitted infections (TTIs). Then, data were entered into SPSS software (Negare. version 25). Chi-square test was used to compare the sof TTIs among blood donors. Chisquare test for trend was used to analyze the variations in trends of TTIs during this period. Finally, p-values less than 0.05 were considered statistically significant. GraphPad Prism software was used for the depiction of the graphs. RESULTS: Among the 1952478 blood donations within the 13-years, 4479(0.229 %) of donors were HBsAg, HCV Ab, and HIV Ag-Ab positive. The seroprevalence of HBV, HCV, and HIV was 2684(0.137%), 1703(0.087 %), and 92(0.0047%), respectively. CONCLUSION: The current study showed that the overall prevalence of TTIs among blood donors was low and had a descending trend over the years of study.


Assuntos
Anticorpos Antivirais/sangue , Doadores de Sangue/estatística & dados numéricos , HIV/imunologia , Hepacivirus/imunologia , Vírus da Hepatite B/imunologia , Reação Transfusional/epidemiologia , Adulto , Estudos Transversais , Feminino , Infecções por HIV/epidemiologia , Infecções por HIV/virologia , Hepatite B/epidemiologia , Hepatite B/virologia , Hepatite C/epidemiologia , Hepatite C/virologia , Humanos , Irã (Geográfico)/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Retrospectivos , Estudos Soroepidemiológicos , Reação Transfusional/virologia
4.
Int J Artif Organs ; 42(2): 95-108, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30345843

RESUMO

In the present study, the effect of adding different concentrations of silicon on physical, mechanical and biological properties of a synthesized aqueous precipitated eggshell-derived hydroxyapatite (e-HA) was evaluated. No secondary phases were detected by X-ray diffraction for the specimens e-HA and e-HA containing silicon (Si-e-HAs) before and after heating at 1200°C. A reduction in the crystallite size and a-axis as well as an increase in c-axis was occurred when silicon replacement was happened in the structure of e-HA. The presence of Si-O vibrations and carbonate modes for Si-e-HAs was confirmed by Fourier transform infrared spectroscopy analysis. The range of porosity and density was varied from 25% and 2.4 g cm-3 to 7% and 2.8 g cm-3 for e-HA and Si-e-HAs. The values of Young's modulus ( E) and compressive strength were varied for e-HA and Si-e-HAs. The porous structure of the samples was reduced when they were heated as e-HA kept the porous microstructure containing some dense areas and Si-e-HAs possessed a rough surface including slight levels of microporosity. The acellular in vitro bioactivity represented different apatite morphologies for e-HA and Si-e-HAs. The G-292 osteoblastic cells were stretched well on the surface with polygon-shaped morphology for 0.8Si-e-HA after 7 days of culture. According to MTT assay and alkaline phosphatase test, the maximum cell activity was related to 0.8Si-e-HA. The minimum inhibitory concentration for 0.8Si-e-HA and e-HA was estimated to be about 3.2 and 4.4 mg/mL, respectively. In overall, the sample 0.8Si-e-HA exhibited a higher bacteriostatic effect than e-HA against gram-negative bacterial strain Escherichia coli.


Assuntos
Materiais Biocompatíveis , Durapatita , Casca de Ovo , Osteossarcoma/patologia , Silício , Animais , Técnicas de Cultura de Células , Linhagem Celular Tumoral , Sobrevivência Celular , Humanos , Teste de Materiais , Microscopia Eletrônica de Varredura , Porosidade , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
5.
Nat Biotechnol ; 34(5): 539-46, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-27088724

RESUMO

Systematic efforts to sequence the cancer genome have identified large numbers of mutations and copy number alterations in human cancers. However, elucidating the functional consequences of these variants, and their interactions to drive or maintain oncogenic states, remains a challenge in cancer research. We developed REVEALER, a computational method that identifies combinations of mutually exclusive genomic alterations correlated with functional phenotypes, such as the activation or gene dependency of oncogenic pathways or sensitivity to a drug treatment. We used REVEALER to uncover complementary genomic alterations associated with the transcriptional activation of ß-catenin and NRF2, MEK-inhibitor sensitivity, and KRAS dependency. REVEALER successfully identified both known and new associations, demonstrating the power of combining functional profiles with extensive characterization of genomic alterations in cancer genomes.


Assuntos
Biomarcadores Tumorais/genética , Mapeamento Cromossômico/métodos , Estudo de Associação Genômica Ampla/métodos , Proteínas de Neoplasias/genética , Neoplasias/genética , Polimorfismo de Nucleotídeo Único/genética , Resistencia a Medicamentos Antineoplásicos/genética , Genes Neoplásicos/genética , Predisposição Genética para Doença/genética , Genoma Humano/genética , Humanos , Mutação/genética , Neoplasias/diagnóstico , Transdução de Sinais/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...