RESUMO
The measurement of the energy spectrum of cosmic ray helium nuclei from 70 GeV to 80 TeV using 4.5 years of data recorded by the Dark Matter Particle Explorer (DAMPE) is reported in this work. A hardening of the spectrum is observed at an energy of about 1.3 TeV, similar to previous observations. In addition, a spectral softening at about 34 TeV is revealed for the first time with large statistics and well controlled systematic uncertainties, with an overall significance of 4.3σ. The DAMPE spectral measurements of both cosmic protons and helium nuclei suggest a particle charge dependent softening energy, although with current uncertainties a dependence on the number of nucleons cannot be ruled out.
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Objective: To develop a solvent desorption-gas chromatography method for determination of trichlorobenzene in workplace air. Methods: Trichlorobenzene in workplace air were captured by Sampling tube consisting of glass fiber filter and solvent desorption activated carbon and desorbed with carbon disulfide, separated through capillary chromatographic column, and then analyzed by gas chromatography-electron capture detector. Results: The linear ranges of 1, 2, 3-trichlorobenzene, 1, 2, 4-trichlorobenzene and 1, 3, 5-trichlorobenzene were 12.20-1220.00, 16.60-1660.00 and 14.80-1480.00 µg/L, respectively, and the related coefficients were between 0.99946 to 0.99948. The relative standard deviations (RSD) within the groups of 1, 2, 3-trichlorobenzene, 1, 2, 4-trichlorobenzene and 1, 3, 5-trichlorobenzene were 1.96%-2.68%, 1.73%-2.82% and 1.81%-2.56%, respectively, and the RSD between the groups were 3.27%-4.25%, 2.85%-4.83% and 3.46%-4.43%, respectively. The average recovery efficiencies were 92.4%, 92.0% and 93.6%, respectively. The minimum quantification concentrations were 0.81, 1.53 and 1.18 µg/m(3), respectively (3 ml desorption solution, 15.00 L sample) . The samples could be stored at room temperature for at least 5 days. Conclusion: This method could be used for monitoring of 1, 2, 3-trichlorobenzene, 1, 2, 4-trichlorobenzene and 1, 3, 5-trichlorobenzene in workplace air.
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Poluentes Ocupacionais do Ar/análise , Clorobenzenos/análise , Cromatografia Gasosa , Local de Trabalho , SolventesRESUMO
ABSTRACT: Objective To perform the separation and confirmation of mixed semen stains with immunological test method, and find a more effective method for the detection of mixed semen stains. Methods The semens of three volunteers were mixed. The mixed semen stains were processed and tested with prostate-specific antigen ï¼PSAï¼ colloidal gold immunoassay strip method, immunomagnetic beads method and laser capture microdissection, respectively. Statistics of the results of STR were gathered and compared with those of a single semen stain. Results After PSA colloidal gold immunoassay strip method testing, the samples showed a purplish red line in the test area and the control area. The results obtained with the immunomagnetic beads method showed a more complete and effective short tandem repeat ï¼STRï¼ sequence. The mixed semen stains were processed with laser capture microdissection and low volume amplified. The results were summarized and superimposed to obtain a complete single typing, which matched the single semen stain typing, with a typing success rate of 84.00%. Single suspect Y-STR typing was obtained with the application of the method above in actual cases, which provided evidence basis for rapid solving of the case. Conclusion The combination of PSA colloidal gold immunoassay strip method, immunomagnetic beads method and laser capture microdissection can be used to separate and confirm the mixed semen stains.
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Sêmen , Corantes , Impressões Digitais de DNA , Medicina Legal , Humanos , Testes Imunológicos , Masculino , Repetições de MicrossatélitesRESUMO
Objective: To develop a solvent desorption-gas chromatography method for determination of ethyl methacrylate(EMA) in workplace air. Methods: EMA in workplace air was captured by charcoal tubes and desorbed with carbon disulfide, separated through capillary chromatographic column, and then analyzed by gas chromatography-flame ionization detector. Results: The linear ranges of EMA were 0.00-9108.00 mg/L, and the related coefficients were 0.999 96. The relative standard deviations(RSD) within the group were 0.55%-1.84%, and the RSD between the group were1.26%-3.30%. The average desorption efficiencies were 98.26%-100.58%. The average samplingefficiencies were 99.98%-100.00%. and the minimum detectable concentration and the minimum quantification concentration were respectively 0.03 mg/m(3) and 0.10 mg/m(3) per 3.00 L of air. The samples could be stored at room temperature for 7 days. Conclusion: This method could be used formonitoring of EMA in workplace air.
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Local de Trabalho , Poluentes Ocupacionais do Ar , Cromatografia Gasosa , Metacrilatos , SolventesRESUMO
Pseudorabies virus (PRV) early protein UL31 is a homologue of herpes simplex virus 1 (HSV-1) UL31, which is a multifunctional protein important for HSV-1 infection. However, the precise roles of PRV UL31 in virus life cycle are still poorly understood. A relatively crucial tool for uncovering the function of UL31 is an antiserum that specifically detects UL31 in the PRV-infected cells. For this purpose, a recombinant UL31 protein consisting of N-terminal 27 aa of UL31 fused to EYFP and His-tag was expressed, purified and used for the preparation of antiserum in BALB/c mice. Our results show that Western blot analysis and immunofluorescence assay showed that this antiserum could specifically detect the purified recombinant UL31 as well as full-length UL31 in the PRV infected cells. These results demonstrate that the prepared antiserum could serve as a valuable tool for further studies of UL31 functions in PRV infection.
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Soros Imunes/imunologia , Proteínas Virais/imunologia , Animais , Chlorocebus aethiops , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Plasmídeos , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/imunologia , Células Vero , Proteínas Virais/análise , Proteínas Virais/genéticaRESUMO
We amplified a 816-bp sequence of the UL31 gene from the pseudorabies virus (PRV) Becker strain genome. Evidence that this was the UL31 gene was confirmed by cloning and sequencing. The PRV UL31 gene encodes a putative protein of 271-amino acid residues, which was designated the UL31 protein. Bioinformatic analysis indicated that PRV UL31 contains a conserved PHA03328 domain, closely related with the herpes virus nuclear egress lamina protein UL31 family and highly conserved among counterparts encoded by herpes UL31 genes. Nucleic acid sequence and amino acid sequence alignments demonstrated that PRV UL31 has a relatively higher homology with UL31 homologous proteins of subfamily Alphaherpesvirinae than other subfamilies. In addition, phylogenetic analysis showed that PRV UL31 has a close evolutionary relationship with members of the subfamily Alphaherpesvirinae, especially bovine herpesvirus 1 (BoHV-1), BoHV-5, equine herpesvirus 4 (EHV-4), EHV-9 and EHV-1. Antigen prediction demonstrated that several potential B-cell epitopes are located in PRV UL31. Additionally, secondary structure and three-dimension structure prediction revealed that PRV UL31 predominantly consists of α-helix. Taken together, these results provide insight on the function and mechanism of UL31 during PRV infection.
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Infecções por Herpesviridae/genética , Herpesvirus Suídeo 1/genética , Proteínas Virais/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Bovinos , Clonagem Molecular , Biologia Computacional , Herpesvirus Suídeo 1/patogenicidade , Proteínas Nucleares/genética , Filogenia , Homologia de Sequência do Ácido NucleicoRESUMO
A 948-bp sequence of the UL2 gene was amplified from the pseudorabies virus (PRV) Becker strain genome using polymerase chain reaction, and the gene identity was confirmed through further cloning and sequencing. Bioinformatic analysis indicated that the PRV UL2 gene encodes a putative polypeptide with 315-amino acid residues. Its encoding protein, designated UL2, has a conserved uracil-DNA glycosylase (UDG)_F1 domain, which is closely related to the herpesvirus UDG family and is highly conserved among its counterparts encoded by UDG genes. Multiple nucleic acid and amino acid sequence alignments suggested that the product of PRV UL2 has a relatively higher homology with UL2-like proteins of Alphaherpesvirinae than that of other subfamilies of Herpesviridae. In addition, phylogenetic analysis showed that PRV UL2 had a close evolutionary relationship with members of Alphaherpesvirinae, especially members of the genus Varicellovirus of bovine herpesvirus 1 and bovine herpesvirus 5. Antigen prediction indicated the presence of several potential B-cell epitopes in PRV UL2. In addition, secondary structure and 3-dimensional structure prediction revealed that PRV UL2 consisted predominantly of an α-helix. Taken together, these results provide molecular biological insight for the further study of the function and mechanism of UL2 during PRV infection.
Assuntos
Herpesvirus Suídeo 1/genética , Uracila-DNA Glicosidase/genética , Proteínas Virais/genética , Sequência de Aminoácidos , Domínio Catalítico , Clonagem Molecular , Genes Virais , Herpesvirus Suídeo 1/enzimologia , Dados de Sequência Molecular , Filogenia , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Uracila-DNA Glicosidase/química , Proteínas Virais/químicaRESUMO
Using polymerase chain reaction, a 1050-bp sequence of the US1 gene was amplified from the pseudorabies virus (PRV) Becker strain genome; identification of the US1 gene was confirmed by further cloning and sequencing. Bioinformatics analysis indicated that the PRV US1 gene encodes a putative polypeptide with 349 amino acids. The encoded protein, designated PICP22, had a conserved Herpes_IE68 domain, which was found to be closely related with the herpes virus immediate early regulatory protein family and is highly conserved among the counterparts encoded by Herpes_IE68 genes. Multiple nucleic acid sequence and amino acid sequence alignments suggested that the product of PRV US1 has a relatively higher homology with ICP22-like proteins of genus Varicellovirus than with those of other genera of Alphaherpesvirinae. In addition, phylogenetic analysis showed that PRV US1 has a close evolutionary relationship with members of the genus Varicellovirus, especially Equid herpes virus 1 (EHV-1), EHV-4 and EHV-9. Antigen prediction indicated that several potential B-cell epitopes are located in PICP22. Also, subcellular localization analysis demonstrated that PICP22 is predominantly located in the cytoplasm, suggesting that it might function as a cytoplasmic-targeted protein.
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DNA Viral/genética , Genes Virais , Herpesvirus Suídeo 1/genética , Proteínas Virais/genética , Alphaherpesvirinae/genética , Sequência de Aminoácidos , Sequência de Bases , Clonagem Molecular/métodos , Biologia Computacional/métodos , Epitopos de Linfócito B/genética , Genoma Viral/genética , Proteínas Imediatamente Precoces/genética , Dados de Sequência Molecular , Filogenia , Homologia de Sequência do Ácido Nucleico , Varicellovirus/genéticaRESUMO
Pseudorabies virus (PRV) early protein UL54 is a homolog of herpes simplex virus 1 immediate-early protein ICP27, which is a multifunctional protein essential for the virus replication. However, the precise role of the PRV UL54 protein in the virus life cycle is still poorly understood. To shed more light on this problem, we considered it essential to have available an antiserum specifically detecting this protein. Since it was known that a full-length UL54 protein is a too big molecule for efficient expression in prokaryotic systems, it was truncated from 1 to 66 N-terminal amino acids, fused to EYFP-His tag and expressed in Escherichia coli through an appropriate expression vector. The truncated protein was purified by Ni-NTA affinity chromatography and used for raising an antiserum in rabbits. Western blot analysis showed that this antiserum specifically recognized the purified truncated as well as full-length UL54 protein in PRV-infected cells. Immunofluorescence assay confirmed the latter finding and also demonstrated localization of this protein first in nucleoli and later in whole nuclei of PRV-infected cells. These results indicate that the prepared antiserum could serve as a valuable tool in further studies of PRV UL54 protein function.
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Anticorpos Antivirais/imunologia , Herpesvirus Suídeo 1/imunologia , Soros Imunes/imunologia , Proteínas Virais/imunologia , Animais , Linhagem Celular , Herpesvirus Suídeo 1/genética , Herpesvirus Suídeo 1/isolamento & purificação , Humanos , Pseudorraiva/diagnóstico , Pseudorraiva/imunologia , Pseudorraiva/virologia , Coelhos , Deleção de Sequência , Proteínas Virais/genética , Proteínas Virais/isolamento & purificaçãoRESUMO
The precise measurement of the spectrum of protons, the most abundant component of the cosmic radiation, is necessary to understand the source and acceleration of cosmic rays in the Milky Way. This work reports the measurement of the cosmic ray proton fluxes with kinetic energies from 40 GeV to 100 TeV, with 2 1/2 years of data recorded by the DArk Matter Particle Explorer (DAMPE). This is the first time that an experiment directly measures the cosmic ray protons up to ~100 TeV with high statistics. The measured spectrum confirms the spectral hardening at ~300 GeV found by previous experiments and reveals a softening at ~13.6 TeV, with the spectral index changing from ~2.60 to ~2.85. Our result suggests the existence of a new spectral feature of cosmic rays at energies lower than the so-called knee and sheds new light on the origin of Galactic cosmic rays.
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Synthesis of a tetrasaccharide fragment, alpha-L-Fuc-(1-->3)-beta-D-GlcNAc-(1-->2)-alpha-D-Man-(1-->6)-alpha-D-Man- OMe of the cobra venom factor (CVF) oligosaccharide is described.
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Venenos Elapídicos/química , Oligossacarídeos/química , Oligossacarídeos/síntese química , Configuração de Carboidratos , Sequência de Carboidratos , Indicadores e Reagentes , Espectroscopia de Ressonância Magnética , Dados de Sequência Molecular , Espectrometria de Massas de Bombardeamento Rápido de ÁtomosRESUMO
Allyl 2-O-benzoyl-4,6-O-benzylidene-alpha-D-glucopyranoside (3), obtained by selective benzoylation of allyl 4,6-O-benzylidene-alpha-D-glucopyranoside (2) with benzoyl chloride-imidazole in anhydrous chloroform, reacted with 2, 3, 4-tri-O-benzoyl-alpha-L-rhamnopyranosyl bromide to give a disaccharide derivative (4), and an important intermediate (5) was obtained by cleavage of its acetal. Treatment of 5 with a series of glycopyranosyl bromides, protected by acetyl or benzoyl groups in benzene-nitromethane in the presence of Hg(CN)2 as a catalyst afforded four trisaccharides (6-9). The disaccharide (5) and trisaccharides (6-9) constitute the sugar cores of phenylpropanoid glycosides. A new glycosyl anomeric leaving group, trichloroacetoxy, was employed to prepare the disaccharide (4) and trisaccharides residue (8) efficiently and with high stereoselectivity.
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Cinamatos , Glicosídeos , Oligossacarídeos/síntese química , Configuração de Carboidratos , Sequência de Carboidratos , Dissacarídeos/síntese química , Dissacarídeos/química , Indicadores e Reagentes , Dados de Sequência Molecular , Estrutura Molecular , Oligossacarídeos/química , Relação Estrutura-Atividade , Trissacarídeos/síntese química , Trissacarídeos/químicaRESUMO
3,6-dioxaoct-1,8-diyl di-(3-O-alpha-D-galactopyranosyl-beta-D-galactopyranoside) was synthesized for use in research on hyperacute rejection of xenotransplantation. The trichloroacetate method was successfully applied to form stereoselectively the alpha-D-galactosyl linkage under mild reaction conditions and a simple procedure. The divalent O-glycoside was formed from the corresponding trichloroacetimidate in one step with reasonable yield.
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Dissacarídeos/síntese química , Epitopos/química , Epitopos/imunologia , Galactose/síntese química , Glicosídeos/síntese química , Rejeição de Enxerto , Transplante Heterólogo/imunologia , Sequência de Carboidratos , Dissacarídeos/imunologia , Galactose/análogos & derivados , Glicosídeos/imunologia , Rejeição de Enxerto/imunologia , Dados de Sequência MolecularRESUMO
Based on the known anti-metastasis activities of lactosides and galactosides, a galactosyl and a lactosyl trimannoside were prepared via the conventional Koenigs-Knorr and trichloroacetimidate methods, respectively. Through typical deblocking procedures, a tetrasaccharide alpha-D-Galp-(1 --> 2)-alpha-D-Manp-(1 --> 2)-alpha-D-Manp-(1 --> 6)-alpha-D-ManpOCH3 and a pentasaccharide beta-D-Galp-(1 --> 4)-beta-D-Glcp-(1 --> 2)-alpha-D-Manp-(1 --> 2)-alpha-D-Manp-(1 --> 6)-alpha-D-ManpOCH3 were obtained.
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Antineoplásicos/síntese química , Galactosídeos/síntese química , Glicosídeos/síntese química , Configuração de Carboidratos , Sequência de Carboidratos , Manosídeos/química , Dados de Sequência Molecular , Metástase Neoplásica/prevenção & controle , Oligossacarídeos/síntese química , Oligossacarídeos/químicaRESUMO
The synthesis is reported of the possible metastatic inhibitors-methyl beta-D-galactopyranosyl-(1-->4) -(2-acetamido-2-deoxy-alpha-D-glucopyranosyl)-(1-->6) -beta-D-galactopyranosyl-(1-->4)-beta-D-glucopyranoside (11) and methyl beta-D-galactopyranosyl- (1-->4)-(2-acetamido-2-deoxy-beta-D-glucopyranosyl)- (1-->6)-beta-D-galactopyranosyl-(1-->4)-beta-D-glucopyranoside (14)-by procedures for regio- and stereo-selective coupling, reduction of azido groups, N-acetylation, and O-deacetylation.
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Antineoplásicos/síntese química , Oligossacarídeos/síntese química , Amino Açúcares/química , Antineoplásicos/farmacologia , Configuração de Carboidratos , Sequência de Carboidratos , Lactose/análogos & derivados , Lactose/química , Espectroscopia de Ressonância Magnética , Dados de Sequência Molecular , Metástase NeoplásicaRESUMO
Studies on the reactivity of two synthetic tetrasaccharides as glycosyl acceptors showed that condensation of the methyl alpha-glycoside with a disaccharide donor afforded a hexasaccharide, but condensation of the methyl beta-glycoside with the disaccharide did not yield the corresponding hexasaccharide under the same conditions. A combination of theoretical results and 2D NMR indicated that the reactivity difference between the methyl alpha-glycoside and the methyl beta-glycoside was determined mainly by steric effects.
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Oligossacarídeos/química , Configuração de Carboidratos , Sequência de Carboidratos , Glicosídeos/química , Modelos Moleculares , Dados de Sequência Molecular , Ressonância Magnética Nuclear BiomolecularRESUMO
A new steroid alkaloid, namely croomionidine (II), together with four known compounds pachysamine A(I), croomine (III), didehydrocroomine (IV) and beta-sitosterol were isolated from the roots of Croomia japonica Miq. Their structures were identified by IR, MS, 1H NMR, 13C NMR and chemical conversion.
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Medicamentos de Ervas Chinesas/química , Pregnanos/isolamento & purificação , Pirrolidinas/isolamento & purificação , Compostos de Espiro/isolamento & purificação , Estrutura Molecular , Pregnanos/química , Pirrolidinas/química , Compostos de Espiro/químicaRESUMO
Seven peptide fragments of HBsAg Pre-S region have been synthesized by liquid phase and solid phase methods. All peptide fragments were linked to protein carrier by carbodiimide and glutaraldehyde methods. The antigen specificity of the peptide--protein conjugates was assayed by anti-HBsAg polyclonal antibodies and anti--"a" monoclonal antibody. P1 and P5 were found to have higher antigen specificity.
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Antígenos de Superfície da Hepatite B , Fragmentos de Peptídeos/síntese química , Precursores de Proteínas , Sequência de Aminoácidos , Epitopos , Antígenos de Superfície da Hepatite B/imunologia , Dados de Sequência Molecular , Fragmentos de Peptídeos/imunologia , Precursores de Proteínas/imunologia , Vacinas contra Hepatite Viral/síntese químicaRESUMO
A new C-nor-D-homo-steroidal alkaloid named taipaienine, together with five known alkaloids namely chuanbeinone, imperialine, verticinone, perimissine and isoverticine were isolated from the bulbs of Fritillaria taipaiensis L. var. ningxiaensis Y. et W.. The unusual structure of taipaienine was a first sample with a hydroxyl group substituted at C-25 of (22)R-trans quinolizidine moiety with orientation of nitrogen lone pair. Their structures were determined by various spectral analyses.
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Cevanas/isolamento & purificação , Medicamentos de Ervas Chinesas/química , Alcaloides/química , Alcaloides/isolamento & purificação , Cevanas/química , Estrutura MolecularRESUMO
Four new C-galactosides were obtained by treatment of 1-O-trifluoroacetly-2, 3, 4, 6-tetra-O-benzly-alpha-D-galactopranose with 7-methoxy-6-(3-pentenyl)-3, 5-dimethylbenzofuran, 7-acetoxy-6-(3-pentenyl)-3, 5-dimethylbenzofuran and 1, 2-dihydrocacalohastin in the presence of Lewis acid. Their structures and compositions were elucidated by elemental analysis and spectroscopic methods. The results of the pharmacological test indicated that the sesquiterpenes are calcium antagonist but their C-galactosides are calcium agonist.