26 research outputs found
Quantum secure communication scheme with W state
Recently, Cao et al. proposed a new quantum secure direct communication
scheme using W state. In their scheme, the error rate introduced by an
eavesdropper who takes intercept-resend attack, is only 8.3%. Actually, their
scheme is just a quantum key distribution scheme because the communication
parties first create a shared key and then encrypt the secret message using
one-time pad. We then present a quantum secure communication scheme using
three-qubit W state. In our scheme, the error rate is raised to 25% and it is
not necessary for the present scheme to use alternative measurement or Bell
basis measurement. We also show our scheme is unconditionally secure.Comment: Comments are welcom
Institutional transformation and marketisation: The changing patterns of housing investment in urban China
10.1016/j.habitatint.2004.02.008Habitat International302327-34
Rhodococcus Genome sequencing and assembly
Bacterial strains, medium, and culture conditions.R. erythropolis ATCC 25544 (American Type Culture Collection) (NBRC 15567 [Biological Resource Center, NITE] [CGMCC 1.2362]), R. rhodochrous ATCC 13808 (CGMCC 4.1147), R. koreensis DSM 44498 (Deutsche Sammlung von Mikroorganismen [German Collection of Microorganisms]) (CGMCC 4.1724), and Pseudomonas aeruginosa CGMCC 1.1129 were purchased from the China General Microbiological Culture Collection Center (CGMCC). R. opacus DSM 43250 (ACCC 41021) was purchased from the Agricultural Culture Collection of China (ACCC). Rhodococcus sp. S2-17 was donated by CheOk Jeon from Chung-Ang University, South Korea, and M. smegmatis MC2-155 was stored in our laboratory. Rhodococcus sp. ZPP was isolated using the floating-filter method (62) from soils that were enriched with 5% ethane. The supernatant of the enriched soil was transferred to and filtered on a sterile polycarbonate membrane filter (0.2 μm; Millipore, MA), and the filter was floated on NMS liquid medium (63) in a plate that was carefully placed in a 2.5-liter sealed jar filled with a 1% (vol/vol) gas phase of ethane. After 3 weeks of incubation, the lawn on the filter was streaked onto a new filter and floated on NMS liquid medium as described above. After 3 weeks, single colonies from the surface of the filter were transported in NMS liquid medium in a sealed serum bottle and incubated with a 1% (vol/vol) gas phase of ethane for 3 weeks to confirm ethane-oxidizing activity. Pure cultures were isolated from 2-fold-diluted R2A agar (Hopebio Technology, Qingdao, China) with a dilution method. All cultures were grown aerobically at 28°C. Twofold-diluted R2A medium was used to scale up the culture. Cells were harvested and washed with normal saline, and washed cells (OD600 of ∼1.0) were used as the stock. NMS medium was used to verify the growth of strains and activity on different substrates (ethane, propane, methane, methanol, ethanol, 1-propanol, and 2-propanol). An ∼1 to 2% (vol/vol) gas phase was added to the headspace of 125-ml sealed serum bottles with 25 ml NMS medium for oxidation and growth assays. As the plasmid pRZP1 in the transconjugant of R. erythropolis ATCC 25544 was not stable in R2A medium, both the donor and the transconjugant were cultured by adding an ∼5% (vol/vol) gas phase to the headspace of 125-ml sealed serum bottles with 25 ml NMS medium to grow cells for the transconjugant-related experiments. Cells were also harvested and washed with normal saline, and washed cells (OD600 of ∼1.0) were also used as the stock.
Analytical techniques.To analyze the ethane- or propane-oxidizing activities, NMS medium (25 ml) with 10-fold-diluted washed cells (final OD600 of ∼0.1) was added to a 125-ml sealed serum bottle. Ethane or propane was added to the headspace (∼1% [vol/vol] gas phase). The contents of ethane and propane in the headspace of serum bottles were analyzed by gas chromatography (GC2020; Ximo, Shanghai, China) with nitrogen as the carrier gas and flame ionization detection. Quantification was performed using a five-point standard curve with different concentrations of calibration gases (Air Liquide, Shanghai, China). To analyze the doubling time and the inhibitory effect of ATU on ethane or propane oxidation, ethane or propane was added to the headspace (∼2% [vol/vol] gas phase), 1,000-fold-diluted washed cells as described above were incubated with or without ATU (0.1 mM) in the cultivation medium with shaking at 150 rpm, the change in the OD600 was monitored, and all gases were replaced after 2 days. Growth on 0.1% (vol/vol) methanol, ethanol, 1-propanol, and 2-propanol was measured by using 1,000-fold-diluted washed cells as described above and monitoring the change in the OD600. Growth on methane was examined by using 1,000-fold-diluted washed cells as described above and monitoring the change in the methane concentration.
Genome sequencing and analysis of plasmids.DNA was extracted using a DNeasy PowerSoil kit (Qiagen, Hilden, Germany) according to the manufacturer’s instructions. The genome of strain ZPP was sequenced using the Illumina HiSeq PE150 platform (Illumina, San Diego, CA) combined with PacBio RSII sequencing (Pacific Biosciences, Menlo Park, CA) and the MinION sequencing platforms (Oxford Nanopore Technologies, Oxford, UK). De novo assembly was performed using HGAP 7.0.1.66975 and Canu 1.8 with default parameters (53, 64). The genome sequence was then polished using Pilon 1.23 with default parameters (65). The NCBI (National Center for Biotechnology Information) Prokaryotic Genome Annotation Pipeline was used for annotation (66). Other genomes were sequenced using the Illumina HiSeq PE150 platform, and de novo assembly was conducted using SPAdes 3.12.0 with default parameters (53). Homologs of the plasmid pRZP1 were investigated using genomic BLASTn with genome sequences of plasmids downloaded from the NCBI database. Plasmids with homologs were then compared and visualized using Mauve (67).
Phylogenetic constructions and compositional analysis of HGT.Maximum likelihood (ML) phylogenies were constructed based on related derived gene or protein sequences. The derived nucleotides were aligned using ClustalW, and the derived amino acids were aligned using Muscle in MEGA X (68). MEGA X or RAxML version 8 was used for ML phylogenetic tree construction (69). The nucleotide sequences of single-copy core genes were identified and aligned using the UBCG pipeline (70). ISfinder (45) (http://www-is.biotoul.fr) was used to annotate IS (insertion sequence) elements.
Mating experiment.Before the mating experiment, the spread plate method with antibiotic gradient plates (up to 20 to 50 μg/ml) was used to detect natural resistance to antibiotics (kanamycin, streptomycin, erythromycin, tetracycline, and ampicillin). The determined concentration of selected antibiotics was confirmed using the corresponding liquid medium. Ampicillin (final concentration, 10 μg/ml) was used to select the transconjugant, as the donor strain ZPP was the nonresistant strain. In contrast, recipient cells were resistant to ampicillin.
In order to achieve conjugation, the donor strain ZPP and each recipient strain were cultivated at 28°C with shaking at 150 rpm for 48 h. Next, donor cells (1 ml) and an equivalent volume of recipient cells were added to 40 ml of 2-fold-diluted R2A liquid medium in Erlenmeyer flasks and mixed briefly. The Erlenmeyer flasks were allowed to stand for 24 h at 28°C. Next, 0.01 ml of the mixed cell cultures was spread on ampicillin (final concentration, 10 μg/ml)-selective NMS plates and cultured in a sealed jar with a 5% (vol/vol) gas phase of propane in the headspace. Seven days later, single colonies were transferred into sealed 125-ml bottles with 25 ml ampicillin (final concentration, 10 μg/ml)-selective NMS liquid medium with a 5% (vol/vol) gas phase of propane. After several rounds of selection, single colonies that possessed the plasmid but were not strain ZPP were transferred to an NMS liquid scale-up culture with propane. Specific primers designed for the detection of hmoA (forward primer e280F [5′-ACCCTATGTGCAGTCGTGTT-3′] and reverse primer e578R [5′-CCGATGTGGAAGGACATTGTG-3′]) and tcpC (forward primer tcpC256f [5′-GACAACGCCACCGAAGACA-3′] and reverse primer tcpC481r [5′-CGTATGTCCGTGACTTCTCCT-3′]) genes in the plasmid and universal primers for the 16S rRNA gene (forward primer 341F [5′-CCTACGGGNGGCWGCAG-3′] and reverse primer 785R [5′-GACTACHVGGGTATCTAATCC-3′]) (71) were used to verify plasmids and strains using real-time quantitative PCR (qPCR) and conventional PCR. Thermal cycling conditions included a 5-min initial denaturation step at 95°C followed by 40 cycles (for qPCR) or 35 cycles (for conventional PCR) of denaturation at 95°C for 30 s, an annealing step at 55°C for 30 s, elongation at 72°C for 30 s, and a final elongation step at 72°C for 10 min (for conventional PCR). Reactions without DNA templates were included in all cases as a negative control.
Measurement of plasmid maintenance.Strain ZPP and the newly obtained transconjugant colonies were cultivated with NMS medium in sealed bottles with a 5% (vol/vol) gas phase of propane to maintain functional plasmids. The bottles were incubated at 28°C for 4 days with shaking at 150 rpm. Subsequently, the cultures (OD600 of ∼0.1) were transferred to fresh 2-fold-diluted R2A liquid medium every day to retain the cells in logarithmic phase. For each transfer, cells were collected to extract DNA and perform qPCR using primers for hmoA, tcpC, and 16S rRNA genes. During this experiment, the negative mutant of strain ZPP was selected from a 2-fold-diluted R2A plate and verified using genome sequencing.
Transcriptomes of the donor and the transconjugant.The donor and the transconjugant were also cultured in sealed bottles with 25 ml NMS medium and a 5% (vol/vol) gas phase of propane at 28°C. The cells of the donor and the transconjugant were harvested in the logarithmic phase after approximately 10 days by centrifugation at 7,000 × g. The supernatant was then filtered through a filter membrane. The total RNA was extracted from this mixture of precipitated cells and the filter membrane residue using a mirVana microRNA (miRNA) isolation kit (Thermo Fisher Scientific, Waltham, MA). The genomic DNA was digested using a recombinant DNase I kit (TaKaRa, Dalian, China). RNA quality was assessed with a Qubit 2.0 instrument and the Qubit RNA HS assay kit. Next, a QIAseq FastSelect 5S/16S/23S kit was used to remove 5S/16S/23S rRNA, according to the manufacturer’s instructions. A QIAseq stranded total RNA library kit was used to build the library according to the manufacturer’s instructions, and cDNA was sequenced on the Illumina PE150 platform. The quality-trimmed reads were mapped to the annotated genome, and TPM values were calculated using RSEM (72) with Bowtie 2 and default parameters (73). The expression levels of housekeeping genes with hig
Aloe emodin induces hepatotoxicity by activating NF-kappa B inflammatory pathway and P53 apoptosis pathway in zebrafish
The aim of this study was to investigate the hepatotoxic effect and its underlying mechanism of aloe emodin (AE). AE was docked with the targets of NF-kappa B inflammatory pathway and P53 apoptosis pathway respectively by using molecular docking technique. To verify the results of molecular docking and further investigate the hepatotoxicity mechanism of AE, the zebrafish Tg (fabp10: EGFP) was used as an animal model in vivo. The pathological sections of zebrafish liver were analyzed to observe the histopathological changes and Sudan black B was used to study whether there were inflammatory reactions in zebrafish liver or not. Then TdT-mediated dUTP Nick-End Labeling (TUNEL) was used to detect the apoptotic signal of zebrafish liver cells, finally the mRNA expression levels as well as the protein expression levels of the targets in NF-kappa B and P53 pathways in zebrafish were measured by quantitative Real-Time PCR (qRT-PCR) and western blot. Molecular docking results showed that AE could successfully dock with all the targets of NF-kappa B and P53 pathways, and the docking scores of most of the targets were equal to or higher than that of the corresponding ligands. Pathological sections showed AE could cause zebrafish liver lesions and the result of Sudan black B staining revealed that AE blackened the liver of zebrafish with Sudan black B. Then TUNEL assay showed that a large number of dense apoptotic signals were observed in AE group, mainly distributed in the liver and yolk sac of zebrafish. The results of qRT-PCR and western blot showed that AE increased the mRNA and protein expression levels of pro-inflammatory and pro-apoptotic targets in NF-kappa B and P53 pathways. AE could activate the NF-kappa B inflammatory pathway and the P53 apoptosis pathway, and its hepatotoxic mechanism was related to activation of NF-.B-P53 inflammation-apoptosis pathways.IP3Immunopathology of vascular and renal diseases and of organ and celltransplantatio
The bacterial diversity in an anaerobic ammonium-oxidizing (anammox) reactor community
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