Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
Nanomaterials (Basel) ; 13(4)2023 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-36839056

RESUMO

Metal sulfides (MS) and mixed metal sulfides (MTMS) have been considered potential candidates over their metal oxide/mixed metal oxide counterparts in recent years. Herein, one MTMS, i.e., NiCo2S4, was combined with 2D MS MoS2 through a single-step solvothermal process with different morphologies (sheet-like and rod-like) for supercapacitor applications. The resulting electrode exhibited excellent coulombic efficiency, high specific capacitance, superior energy density, and, most importantly, ultra-high cycling stability. In particular, the electrode delivered a capacitance of 2594 F g-1 at 0.8 A g-1 after 45,000 charge/discharge cycles with a remarkable stability of 192%. Moreover, the corresponding hybrid supercapacitor device displayed an impressive coulombic efficiency of 123% after 20,000 cycles and 118% after 45,000 cycles. In addition, the device also exhibited a decent energy density of 31.9 Wh kg-1 and good cycling stability of 102% over 15,000 cycles.

2.
Phytopathology ; 113(2): 334-344, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36129763

RESUMO

Papaya (Carica papaya) production is seriously limited by papaya ringspot virus (PRSV) worldwide, including in Vietnam. Control of PRSV by cross protection is dependent on the availability of effective mild strains. Here, an infectious cDNA clone was constructed from PRSV isolate TG5 from South Vietnam. Site-directed mutagenesis with point mutations on the essential motifs of the helper component proteinase (HC-Pro) was performed, with or without deleting five amino acids (d5) from its N-terminal region. Mutants TG-d5, TG-d5I7, and TG-d5L206 containing d5, d5 + F7I, and d5 + F206L, respectively, induced mild mottling followed by symptomless recovery on papaya and infected Chenopodium quinoa without lesion formation. Each mutant accumulated in papaya at reduced levels with a zigzag pattern and was stable beyond six monthly passages. The cross-protection effectiveness of the three mutants in papaya against TG5 was investigated, each with 60 plants from three independent trials. The results showed that each mutant provided complete protection (100%) against TG5, 1 month after the challenge inoculation, as verified by the lack of severe symptoms and lack of local lesions in C. quinoa. Further tests revealed that TG-d5I7 also confers high levels of protection against other severe PRSV isolates from South Vietnam, including isolates DN (97%) and ST2 (50%). However, TG-d5I7 is ineffective or less effective (0 to 33%) against seven other severe PRSV strains from different geographic origins, including the isolate HN from North Vietnam. Our results indicate that the protection by the three mutants is highly strain-specific and suitable for the control of PRSV in South Vietnam.


Assuntos
Carica , Potyvirus , Peptídeo Hidrolases/metabolismo , Vietnã , Proteção Cruzada , Doenças das Plantas/prevenção & controle , Potyvirus/genética , Gerenciamento Clínico
3.
Energy Build ; 270: 112286, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-35814481

RESUMO

In this paper, we present the concept and formulation of a short-term Markov corrector to an underlying day-ahead building load forecasting model. The models and the correctors are then integrated to the building supervision, control and data acquisition system to automate the self-updating and retraining processes. The proposed Markov corrector is experimentally proven to significantly improve the reactivity of the forecasting models with respect to untaught variations. Developed in a discrete manner over a continuous forecasting model, the corrector also helps to capture better the consumption peaks during the activity days. A proof-of-concept is demonstrated via the case study of the GreenER building, where the impact of the Markov correctors to the performance of the existing day-ahead load forecasting system (based on Prophet model) was analyzed during the 2021/2022 winter, under the influences of the Omicron wave of the COVID-19 pandemic.

4.
Phytopathology ; 112(3): 708-719, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34384243

RESUMO

Papaya ringspot virus (PRSV) causes severe damage to papaya (Carica papaya L.) and is the primary limiting factor for papaya production worldwide. A nitrous acid-induced mild strain, PRSV HA 5-1, derived from Hawaii strain HA, has been applied to control PRSV by cross-protection for decades. However, the problem of strain-specific protection hampers its application in Taiwan and other geographic regions outside Hawaii. Here, sequence comparison of the genomic sequence of HA 5-1 with that of HA revealed 69 nucleotide changes, resulting in 31 aa changes, of which 16 aa are structurally different. The multiple mutations of HA 5-1 are considered to result from nitrous acid induction because 86% of nucleotide changes are transition mutations. The stable HA 5-1 was used as a backbone to generate recombinants carrying individual 3' fragments of Vietnam severe strain TG5, including NIa, NIb, and CP3' regions, individually or in combination. Our results indicated that the best heterologous fragment for the recombinant is the region of CP3', with which symptom attenuation of the recombinant is like that of HA 5-1. This mild recombinant HA51/TG5-CP3' retained high levels of protection against the homologous HA in papaya plants and significantly increased the protection against the heterologous TG-5. Similarly, HA 5-1 recombinants carrying individual CP3' fragments from Thailand SMK, Taiwan YK, and Vietnam ST2 severe strains also significantly increase protection against the corresponding heterologous strains in papaya plants. Thus, our recombinant approach for mild strain generation is a fast and effective way to minimize the problem of strain-specific protection.


Assuntos
Carica , Potyvirus , Doenças das Plantas/prevenção & controle , Potyvirus/genética , Taiwan
5.
Sensors (Basel) ; 20(8)2020 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-32316205

RESUMO

Radio-frequency technologies are widely applied in many fields such as mobile systems, healthcare systems, television and radio broadcasting, and satellite communications. However, one major problem in wireless communication based on radio frequencies is its impact on human health. High frequencies adversely impact human health more than low frequencies if the signal power transgresses the permissible threshold. Therefore, researchers are investigating the use of visible light waves (instead of the radio-frequency band) for data transmission in three major areas: visible light communication, light fidelity, and optical camera communication. In this paper, we propose a scheme that upgrades the camera on-off keying (COOK) scheme by using it with the multiple-input multiple-output (MIMO) scheme; COOK has been recommended by the IEEE 802.15.7-2018 standard. By applying technologies, such as matched filter, region of interest, and MIMO, our proposed scheme promises to improve the performance of the conventional scheme by improving the data rate, communication distance, and bit error rate. By controlling the exposure time, the focal length in a single camera and using channel coding, our proposed scheme can achieve the communication distance of up to 20 m, with a low error rate.

6.
Int J Biol Macromol ; 121: 718-726, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30339999

RESUMO

In this study, low molecular weight chitosan salt (LMWC-HCl) highly soluble in water was prepared from low molecular weight chitosan (LMWC) in the solid state exposed to hydrogen chloride gas as a reagent. The effects of chitosan particle size, exposure conditions, reaction temperature and reaction time were investigated on the solubility and the molecular weight of obtained products. The formation of the chloride salt was observed after 3 h in a range of temperatures from 4 to 50 °C. The solubility of prepared LMWC-HCl was over 98% for all samples, much higher than that of the original LMWC. The average molecular weight of the LMWC-HCl was about 20-90 kDa with a quite narrow distribution and lower compared to the LMWC. LMWC-HCl and LMWC showed the same high antibacterial activity against Bacillus cereus and Vibrio parahaemolyticus. This facile and efficient process for solubilization of LMWC has potential for industrial application of chitosan.


Assuntos
Antibacterianos/química , Quitosana/química , Água/química , Antibacterianos/farmacologia , Bacillus cereus/efeitos dos fármacos , Quitosana/farmacologia , Concentração de Íons de Hidrogênio , Peso Molecular , Solubilidade , Temperatura , Vibrio parahaemolyticus/efeitos dos fármacos
7.
PLoS One ; 10(12): e0145230, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26683994

RESUMO

BACKGROUND: Hemoglobin Constant Spring (Hb CS) is an abnormal Hb caused by a mutation at the termination codon of α2-globin gene found commonly among Southeast Asian and Chinese people. Association of Hb CS with α°-thalassemia leads to a thalassemia intermedia syndrome commonly encountered in the region. We report chromosome background and addressed genetic origins of Hb CS observed in a large cohort of Hb CS among Southeast Asian populations. MATERIALS AND METHODS: A study was done on 102 Vietnamese (aged 15-49 year-old) and 40 Laotian (aged 18-39 year-old) subjects with Hb CS and results compared with 120 Hb CS genes in Thailand. Hematological parameters were recorded and Hb analysis was performed using capillary electrophoresis. Hb CS mutation and thalassemia genotypes were defined by DNA analysis. Six DNA polymorphisms within α-globin gene cluster including 5'Xba I, Bgl I, Inter-zeta HVR, AccI, RsaI and αPstI 3', were determined using PCR-RFLP assay. RESULTS: Nine different genotypes of Hb CS were observed. In contrast to the Thai Hb CS alleles which are mostly linked to haplotype (+-S + + -), most of the Vietnamese and the Laotian Hb CS genes were associated with haplotype (+-M + + -), both of which are different from that of the European Hb CS. CONCLUSIONS: Hb CS is commonly found in combination with other thalassemias among Southeast Asian populations. Accurate genotyping of the cases requires both hematologic and DNA analyses. At least two independent origins are associated with the Hb CS gene which could indirectly explain the high prevalence of this Hb variant in the region.


Assuntos
Hemoglobinas Anormais/genética , Talassemia alfa/genética , Adolescente , Adulto , Povo Asiático/genética , Análise Mutacional de DNA , Feminino , Estudos de Associação Genética , Heterogeneidade Genética , Haplótipos , Humanos , Laos/epidemiologia , Pessoa de Meia-Idade , Filogenia , Prevalência , Vietnã/epidemiologia , Adulto Jovem , Talassemia alfa/epidemiologia
8.
Mater Sci Eng C Mater Biol Appl ; 44: 144-50, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25280690

RESUMO

Conducting poly(o-phenylenediamine) (POPD)/graphene oxide (GO) composites were prepared using a facile and efficient method involving the in-situ polymerization of OPD in the presence of GO in an aqueous medium. Copper sulfate was used as an oxidative initiator for the polymerization of OPD. Scanning electron microscopy and transmission electron microscopy images showed that POPD microfibrils were formed and distributed relatively uniformly with GO sheets in the obtained composites. X-ray diffraction results revealed the highly crystal structure of POPD. This composite exhibited good catalytic activity and stability. These results highlight the potential applications of POPD/GO composites as excellent electrochemical sensors. The composites were used to modify glass carbon electrodes for the chemical detection of hydrogen peroxide in aqueous media.


Assuntos
Carbono/química , Grafite/química , Peróxido de Hidrogênio/análise , Fenilenodiaminas/química , Eletrodos , Vidro/química , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Polimerização , Difração de Raios X
9.
Blood Cells Mol Dis ; 52(4): 161-5, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24368026

RESUMO

A community-based survey was conducted to determine the prevalence and gene frequency of Hemoglobin Constant Spring (Hb CS) and other forms of thalassemia among an ethnic minority in Vietnam. A total of 298 ethnic minority women, the Có-Tu, participated. Hematological parameters and hemoglobin profiles were analyzed using standard automated analyzers. Alpha- and beta-thalassemia mutations were identified using polymerase chain reaction (PCR) based technology. Of the 298 women, 141 (47.3%) carried thalassemia genes. Hemoglobin Constant Spring (Hb CS) is the most common with a markedly high frequency of 0.143 (overall prevalence=26.2%). The heterozygous state of Hb CS was found in one-fifth (20.5%) of women participating. Seven women (2.4%) were Hb CS homozygote. The overall prevalence for Hb E was 13.8%, and 10.7% for α(+)-thalassemia. Other forms of thalassemia included 0.67% ß-thalassemia, and 0.34% Hb Paksé. None of the participants had the α(0)-thalassemia gene. The study provides basic epidemiological information about Hb CS as well as other forms of thalassemia for a specific group of an ethnic minority in Vietnam. The data will be useful for further study on the distribution of thalassemia in Southeast Asia.


Assuntos
Povo Asiático/genética , Frequência do Gene , Hemoglobinas Anormais/genética , Grupos Minoritários , Alelos , Feminino , Geografia , Hemoglobinopatias/epidemiologia , Hemoglobinopatias/genética , Heterozigoto , Homozigoto , Humanos , Prevalência , Talassemia/epidemiologia , Talassemia/genética , Vietnã/epidemiologia
10.
BMC Bioinformatics ; 10: 329, 2009 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-19821978

RESUMO

BACKGROUND: Sequence similarity searching is an important and challenging task in molecular biology and next-generation sequencing should further strengthen the need for faster algorithms to process such vast amounts of data. At the same time, the internal architecture of current microprocessors is tending towards more parallelism, leading to the use of chips with two, four and more cores integrated on the same die. The main purpose of this work was to design an effective algorithm to fit with the parallel capabilities of modern microprocessors. RESULTS: A parallel algorithm for comparing large genomic banks and targeting middle-range computers has been developed and implemented in PLAST software. The algorithm exploits two key parallel features of existing and future microprocessors: the SIMD programming model (SSE instruction set) and the multithreading concept (multicore). Compared to multithreaded BLAST software, tests performed on an 8-processor server have shown speedup ranging from 3 to 6 with a similar level of accuracy. CONCLUSION: A parallel algorithmic approach driven by the knowledge of the internal microprocessor architecture allows significant speedup to be obtained while preserving standard sensitivity for similarity search problems.


Assuntos
Biologia Computacional/métodos , Bases de Dados Factuais , Software , Algoritmos , Armazenamento e Recuperação da Informação/métodos , Microcomputadores
11.
BMC Bioinformatics ; 9: 534, 2008 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-19087280

RESUMO

BACKGROUND: Similarity inference, one of the main bioinformatics tasks, has to face an exponential growth of the biological data. A classical approach used to cope with this data flow involves heuristics with large seed indexes. In order to speed up this technique, the index can be enhanced by storing additional information to limit the number of random memory accesses. However, this improvement leads to a larger index that may become a bottleneck. In the case of protein similarity search, we propose to decrease the index size by reducing the amino acid alphabet. RESULTS: The paper presents two main contributions. First, we show that an optimal neighborhood indexing combining an alphabet reduction and a longer neighborhood leads to a reduction of 35% of memory involved into the process, without sacrificing the quality of results nor the computational time. Second, our approach led us to develop a new kind of substitution score matrices and their associated e-value parameters. In contrast to usual matrices, these matrices are rectangular since they compare amino acid groups from different alphabets. We describe the method used for computing those matrices and we provide some typical examples that can be used in such comparisons. Supplementary data can be found on the website http://bioinfo.lifl.fr/reblosum. CONCLUSION: We propose a practical index size reduction of the neighborhood data, that does not negatively affect the performance of large-scale search in protein sequences. Such an index can be used in any study involving large protein data. Moreover, rectangular substitution score matrices and their associated statistical parameters can have applications in any study involving an alphabet reduction.


Assuntos
Indexação e Redação de Resumos/métodos , Algoritmos , Biologia Computacional/métodos , Alinhamento de Sequência/métodos , Análise de Sequência de Proteína/métodos , Bases de Dados de Proteínas , Armazenamento e Recuperação da Informação , Proteínas/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA