• 제목/요약/키워드: key protection

검색결과 933건 처리시간 0.032초

Rapid Analysis of Tetraconazole Residues in Fruits and Vegetables using Ethyl Acetate Extraction and Gas Chromatography-tandem Mass Spectrometry

  • Xu, Jun;Dong, Fengshou;Liu, Xingang;Li, Jing;Li, Yuanbo;Shan, Weili;Zheng, Yongquan
    • Bulletin of the Korean Chemical Society
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    • 제32권12호
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    • pp.4265-4269
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    • 2011
  • A method based on ethyl acetate extraction and gas chromatography with tandem mass spectrometry was developed for determining tetraconazole residues in fruits and vegetables. A 10 g homogenized sample was mixed with 10 mL ethyl acetate, shaken vigorously for 3 min, stored at $-20^{\circ}C$ for 15 min, and then vortexed vigorously for 1 min; 1 g NaCl and 4 g anhydrous $MgSO_4$ were added. The clean-up was carried out by applying dispersive solid-phase with 150 mg $MgSO_4$and 50 mg primary secondary amine. Three precursor product ion transitions for tetraconazole were measured and evaluated to provide the maximum degree of confidence. Average recoveries in fruits and vegetables at three levels (0.005, 0.05 and 0.5 mg/kg) ranged from 85.53% to 110.66% with relative standard deviations ($RSD_r$) from 1.3% to 17.5%. The LODs ranged from 0.002 to 0.004 ${\mu}g$/kg, and LOQs ranged from 0.006 to 0.012 ${\mu}g$/kg. This method was also applied to determine tetraconazole residue in cucumber dissipation experiment under field conditions. The half-lives of tetraconazole in cucumber were in the range of 2.1-3.1 days.

Molecular Characterization of an Isolate of Bean Common Mosaic Virus First Identified in Gardenia Using Metatranscriptome and Small RNA Sequencing

  • Zhong-Tian Xu;Hai-Tao Weng;Jian-Ping Chen;Chuan-Xi Zhang;Jun-Min Li;Yi-Yuan Li
    • The Plant Pathology Journal
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    • 제40권1호
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    • pp.73-82
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    • 2024
  • Gardenia (Gardenia jasminoides) is a popular and economically vital plant known for its ornamental and medicinal properties. Despite its widespread cultivation, there has been no documentation of plant viruses on gardenia yet. In the present study, gardenia leaves exhibiting symptoms of plant viral diseases were sampled and sequenced by both metatranscriptome and small RNA sequencing. As a consequence, bean common mosaic virus (BCMV) was identified in gardenia for the first time and named BCMV-gardenia. The full genome sequence of BCMV-gardenia is 10,054 nucleotides (nt) in length (excluding the poly (A) at the 3' termini), encoding a large polyprotein of 3,222 amino acids. Sequence analysis showed that the N-termini of the polyprotein encoded by BCMV-gardenia is less conserved when compared to other BCMV isolates, whereas the C-termini is the most conserved. Maximum likelihood phylogenetic analysis showed that BCMVgardenia was clustered closely with other BCMV isolates identified outside the leguminous plants. Our results indicated that the majority of BCMV-gardenia virus-derived small interfering RNAs (vsiRNAs) were 21 nt and 22 nt, with 21 nt being more abundant. The first nucleotide at the 5' termini of vsiRNAs derived from BCMV-gardenia preferred U and A. The ratio of vsiRNAs derived from sense (51.1%) and antisense (48.9%) strands is approaching, and the distribution of vsiRNAs along the viral genome is generally even, with some hot spots forming in local regions. Our findings could provide new insights into the diversity, evolution, and host expansion of BCMV and contribute to the prevention and treatment of this virus.

Characterization of ginsenoside compound K loaded ionically cross-linked carboxymethyl chitosan-calcium nanoparticles and its cytotoxic potential against prostate cancer cells

  • Zhang, Jianmei;Zhou, Jinyi;Yuan, Qiaoyun;Zhan, Changyi;Shang, Zhi;Gu, Qian;Zhang, Ji;Fu, Guangbo;Hu, Weicheng
    • Journal of Ginseng Research
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    • 제45권2호
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    • pp.228-235
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    • 2021
  • Backgroud: Ginsenoside compound K (GK) is a major metabolite of protopanaxadiol-type ginsenosides and has remarkable anticancer activities in vitro and in vivo. This work used an ionic cross-linking method to entrap GK within O-carboxymethyl chitosan (OCMC) nanoparticles (Nps) to form GK-loaded OCMC Nps (GK-OCMC Nps), which enhance the aqueous solubility and stability of GK. Methods: The GK-OCMC Nps were characterized using several physicochemical techniques, including x-ray diffraction, transmission electron microscopy, zeta potential analysis, and particle size analysis via dynamic light scattering. GK was released from GK-OCMC Nps and was conducted using the dialysis bag diffusion method. The effects of GK and GK-OCMC Nps on PC3 cell viability were measured by using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay. Fluorescent technology based on Cy5.5-labeled probes was used to explore the cellular uptake of GK-OCMC Nps. Results: The GK-OCMC NPs had a suitable particle size and zeta potential; they were spherical with good dispersion. In vitro drug release from GK-OCMC NPs was pH dependent. Moreover, the in vitro cytotoxicity study and cellular uptake assays indicated that the GK-OCMC Nps significantly enhanced the cytotoxicity and cellular uptake of GK toward the PC3 cells. GK-OCMC Nps also significantly promoted the activities of both caspase-3 and caspase-9. Conclusion: GK-OCMC Nps are potential nanocarriers for delivering hydrophobic drugs, thereby enhancing water solubility and permeability and improving the antiproliferative effects of GK.

무선 메쉬망에서의 안전하고 효율적인 키관리 스킴 (Secure and Efficient Key Management Scheme for Wireless Mesh Network)

  • ;;이상곤;이훈재
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2011년도 춘계학술발표대회
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    • pp.844-847
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    • 2011
  • Wireless mesh network (WMN) is a type of mobile ad-hoc network consists of wireless router, mobile clients and gateway which connects the network with the Internet. To provide security in the network it is required to encrypt the message sent among the communicating nodes in such way so that only legitimate user can retrieve the original data. Several security mechanisms have been proposed so far to enhance the security of WMN. However, there still exists a need for a comprehensive mechanism to prevent attacks in data communication. Considering the characteristic of mesh network, in this paper we proposed a public key cryptography based security architecture to establish a secure key agreement among communicating nodes in mesh network. The proposed security architecture consists of two major sections: client data protection and network data protection. Client data protection deals with the mutual authentication between the client and the access router and provide client to access router encryption for data confidentiality using standard IEEE 802.11i protocol. On the other hand, network data protection ensures encrypted routing and data transfer in the multi hop backbone network. For the network data protection, we used the pre-distributed public key to form a secure backbone infrastructure.

Radiation Induces Phosphorylation of STAT3 in a Dose- and Time-dependent Manner

  • Gao, Ling;Li, Feng-Sheng;Chen, Xiao-Hua;Liu, Qiao-Wei;Feng, Jiang-Bin;Liu, Qing-Jie;Su, Xu
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권15호
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    • pp.6161-6164
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    • 2014
  • Background: We have reported the radiation could activate STAT3, which subsequently promotes the invasion of A549 cells. We here explored the dose- and time-response of STAT3 to radiation and the effect of radiation on upstream signaling molecules. Materials and Methods: A549 cells were irradiated with different doses of ${\gamma}$-rays. The expression of and nucleus translocation of p-STAT3 in A549 cells were detected by immunoblotting and immunofluorescence, respectively. The level of phosphorylated EGFR was also assessed by immunoblotting, and IL-6 expression was detected by real time PCR and ELISA. Results: Radiation promoted the phosphorylation of STAT3 at Y705 in a dose- and time-dependent manner and nuclear translocation. The level of phosphorylated EGFR in A549 cells increased after radiation. In additional, the mRNA and protein levels of IL-6 in A549 cells were also up regulated by radiation. Conclusions: STAT3 is activated by radiation in a dose-and time-dependent manner, probably due to radiation-induced activation of EGFR or secretion of IL-6 in A549 cells.

Screening of key miRNAs related with the differentiation of subcutaneous adipocytes and the validation of miR-133a-3p functional significance in goats

  • Xin, Li;Hao, Zhang;Yong, Wang;Yanyan, Li;Youli, Wang;Jiangjiang, Zhu;Yaqiu, Lin
    • Animal Bioscience
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    • 제36권1호
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    • pp.144-155
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    • 2023
  • Objective: Adipocyte differentiation is regulated by a variety of functional genes and noncoding RNAs. However, the role of miRNAs in lipid deposition of goat white adipose tissue is still unclear. Therefore, this study revealed the miRNA expression profile in goat subcutaneous adipocytes by sRNA-seq. Methods: The miRNA expressed in goat subcutaneous preadipocytes and the mature adipocytes were sequenced by sRNA-seq. The differentially expressed miRNAs (DEm) were screened and gene ontology (GO) and Kyoto encyclopedia for genes and genomes (KEGG) analyses were performed. Gain-of-function and loss-of-function combined with oil red O staining, Bodipy staining, and quantitative reverse-transcription polymerase chain reaction (qPCR) were utilized to determine the effect of miR-133a-3p on adipocyte differentiation. Results: A total of 218 DEm were screened out. The target genes of these DEm were significantly enriched in GO items such as biological regulation and in KEGG terms such as FAK signaling pathway and MAPK signaling pathway. qPCR verified that the expression trend of miRNA was consistent with miRNA-seq. The gain-of-function or loss-of-function of miR-133a-3p showed that it promoted or inhibited the accumulation of lipid droplets, and CCAAT enhancer binding protein α (C/EBPα) and C/EBPβ were extremely significantly up-regulated or down-regulated respectively (p<0.01), the loss-of-function also led to a significant down-regulation of peroxisome proliferator activated receptor gamma (PPARγ) (p<0.01). Conclusion: This study successfully identified miRNAs expression patterns in goat subcutaneous adipocytes, and functional identification indicates that miR-133a-3p is a positive regulator of the differentiation process of goat subcutaneous adipocytes. Our results lay the foundation for the molecular mechanism of lipid deposition in meat-source goats from the perspective of miRNA.

RFID-based Secure Communication for Smart Device in Future Home Network Environment

  • Li, Nong-Jun;Choi, Kee-Hyun;Jang, Kyung-Soo;Shin, Dong-Ryeol
    • International Journal of Internet, Broadcasting and Communication
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    • 제5권1호
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    • pp.18-22
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    • 2013
  • We introduce, in this paper, a novel approach of protection mechanism for data which are transmitted not only between the networked devices but also between the digital media devices. As the devices are getting more powerful and more storage capacity, they can process the encoded/encrypted data autonomously. However, all devices must know the secret key that used to encrypt data, and also use secure method to distribute that key. Moreover, there are no protection mechanisms supporting end-to-end copy protection which result in the fact that the data passed through various devices can be manipulated or captured. Therefore, we propose a RFID-based key distribution and protection mechanism to resolve these problems.

Highly catalysis Zinc MOF-loaded nanogold coupled with aptamer to assay trace carbendazim by SERS

  • Jinling Shi;Jingjing Li;Aihui Liang;Zhiliang Jiang
    • Advances in nano research
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    • 제14권4호
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    • pp.313-327
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    • 2023
  • Zinc metal organic framework (MOFZn)-loaded goad nanoparticles (AuNPs) sol (Au@MOFZn), which was characterized by TEM, Mapping, FTIR, XRD, and molecular spectrum, was prepared conveniently by solvothermal method. The results indicated that Au@MOFZn had a very strong catalytic effect with the nanoreaction of AuNPs formation between sodium oxalate (SO) and HAuCl4. AuNPs in the new indicator reaction had a strong resonance Rayleigh scattering (RRS) signal at 370 nm. The indicator AuNPs generated by this reaction, which had the most intense surface enhanced Raman scattering (SERS) peak at 1621 cm -1. The new SERS/RRS indicator reaction in combination with specific aptamer (Apt) to fabricate a sensitive and selective Au@MOFZn catalytic amplification-aptamer SERS/RRS assay platform for carbendazim (CBZ), with SERS/RRS linear range of 0.025-0.5 ng/mL. The detection limit was 0.02 ng/mL. Similarly, this assay platform has been also utilized to detect oxytetracycline (OTC) and profenofos (PF).

Review of Leptocimbex formosanus group (Hymenoptera: Cimbicidae) with two new Chinese species

  • YAN, Yuchen;NIU, Gengyun;LAN, Bocheng;WEI, Meicai
    • Entomological Research
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    • 제48권5호
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    • pp.372-383
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    • 2018
  • Leptocimbex formosanus group of Leptocimbex Semenov 1896, Cimbicidae is defined and the relationships and characteristics are provided. Two new species of this group are described from Hunan and Yunnan Provinces in China: Leptocimbex shinoharai Yan & Wei sp. nov. and L. naitoi Yan & Wei sp. nov. Redescriptions of the three known species of L. formosanus group (L. formosanus Enslin 1911, L. dendrobii Rohwer 1915 and L. nigropropodea Wei & Deng 2002) and a key to all known species of this group are provided.

Development of a structure analytic hierarchy approach for the evaluation of the physical protection system effectiveness

  • Zou, Bowen;Wang, Wenlin;Liu, Jian;Yan, Zhenyu;Liu, Gaojun;Wang, Jun;Wei, Guanxiang
    • Nuclear Engineering and Technology
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    • 제52권8호
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    • pp.1661-1668
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    • 2020
  • A physical protection system (PPS) is used for the protection of critical facilities. This paper proposes a structure analytic hierarchy approach (SAHA) for the hierarchical evaluation of the PPS effectiveness in critical infrastructure. SAHA is based on the traditional analysis methods "estimate of adversary sequence interruption, EASI". A community algorithm is used in the building of the SAHA model. SAHA is applied to cluster the associated protection elements for the topological design of complicated PPS with graphical vertexes equivalent to protection elements.