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1.
Zhonghua Yu Fang Yi Xue Za Zhi ; 57(9): 1523-1528, 2023 Sep 06.
Artigo em Zh | MEDLINE | ID: mdl-37743318

RESUMO

With the decline in hepatitis B virus (HBV) incidence and the increase in the life expectancy of infected individuals, the population infected with HBV is experiencing rapid aging, leading to an escalating risk of co-morbid chronic noncommunicable diseases (NCDs). This study summarizes research related to the comorbidity between HBV and NCDs, discussing the aging of the HBV-infected population, the mechanisms, prevalence, and management of this comorbidity. This study provides insights into potential directions for future research on the comorbidity between HBV and NCDs and aims to provide a basis for further research and the development of prevention and treatment strategies for the comorbidity of NCDs among HBV-infected individuals in China.


Assuntos
Hepatite B , Doenças não Transmissíveis , Humanos , Vírus da Hepatite B , Doenças não Transmissíveis/epidemiologia , Hepatite B/epidemiologia , Comorbidade , China/epidemiologia
2.
Artigo em Zh | MEDLINE | ID: mdl-36882277

RESUMO

Objective: To study the correlation between ceramic and chronic obstructive pulmonary disease (COPD), and explore its related risk factors. Methods: In January 2021, five representative ceramic enterprises were selected from Chancheng District, Nanhai District, Gaoming District and Sanshui District of Foshan City. The ceramic workers who came to Chancheng Hospital of Foshan First People's Hospital for physical examination from January to October 2021 were selected as the research objects, and 525 people were included. Conduct questionnaire survey and pulmonary function test. Logistic regresion was performed to analyze the influencing facters of COPD among ceramic workers. Results: The subjects were (38.51±1.25) years old, 328 males and 197 females, and the detection rate of COPD was 9.52% (50/525). The incidence of respiratory symptoms such as dyspnea, chronic cough, wheezing and chest tightness, the detection rates of abnormal lung age, abnormal lung function and COPD in males were higher than those in females (P<0.05). The logistic regression analysis showed that male, age, working years, smoking status and family history of COPD were the risk factors for COPD among ceramic workers (P<0.05) . Conclusion: The ceramic workers are the high risk population of COPD. We should do a good job in health education, and do a regular physical examination to find the changes of lung function in time, and prevent the occurrence of COPD as soon as possible.


Assuntos
Doença Pulmonar Obstrutiva Crônica , Feminino , Humanos , Masculino , Adulto , Doença Pulmonar Obstrutiva Crônica/epidemiologia , Cerâmica , Educação em Saúde , Hospitais , Exame Físico
3.
Phys Rev Lett ; 126(19): 197001, 2021 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-34047570

RESUMO

The recent discovery of superconductivity in doped infinite-layer nickelates has stimulated intensive interest, especially for similarities and differences compared to that in cuprate superconductors. In contrast to cuprates, although earlier magnetization measurement reveals a Curie-Weiss-like behavior in undoped infinite-layer nickelates, there is no magnetic ordering observed by elastic neutron scattering down to liquid helium temperature. Until now, the nature of the magnetic ground state in undoped infinite-layer nickelates was still elusive. Here, we perform a nuclear magnetic resonance (NMR) experiment through ^{139}La nuclei to study the intrinsic spin susceptibility of infinite-layer LaNiO_{2}. First, the signature for magnetic ordering or freezing is absent in the ^{139}La NMR spectrum down to 0.24 K, which unambiguously confirms a paramagnetic ground state in LaNiO_{2}. Second, a pseudogaplike behavior instead of Curie-Weiss-like behavior is observed in both the temperature-dependent Knight shift and nuclear spin-lattice relaxation rate (1/T_{1}), which is widely observed in both underdoped cuprates and iron-based superconductors. Furthermore, the scaling behavior between the Knight shift and 1/T_{1}T has also been discussed. Finally, the present results imply a considerable exchange interaction in infinite-layer nickelates, which sets a strong constraint for the proposed theoretical models.

4.
Phys Rev Lett ; 125(9): 097003, 2020 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-32915588

RESUMO

Superconductivity arises from two distinct quantum phenomena: electron pairing and long-range phase coherence. In conventional superconductors, the two quantum phenomena generally take place simultaneously, while in the underdoped high- T_{c} cuprate superconductors, the electron pairing occurs at higher temperature than the long-range phase coherence. Recently, whether electron pairing is also prior to long-range phase coherence in single-layer FeSe film on SrTiO_{3} substrate is under debate. Here, by measuring Knight shift and nuclear spin-lattice relaxation rate, we unambiguously reveal a pseudogap behavior below T_{p}∼60 K in two kinds of layered FeSe-based superconductors with quasi2D nature. In the pseudogap regime, a weak diamagnetic signal and a remarkable Nernst effect are also observed, which indicates that the observed pseudogap behavior is related to superconducting fluctuations. These works confirm that strong phase fluctuation is an important character in the 2D iron-based superconductors as widely observed in high-T_{c} cuprate superconductors.

5.
Bull Entomol Res ; 104(5): 622-30, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24871255

RESUMO

Whiteflies have distinct nymphal stages: their first stage is mobile, whereas the later immature stages are sessile. The developmental and structural changes of antennae and antennal sensilla in whiteflies during these stages have rarely been investigated. This paper describes the morphology of antennae and antennal sensilla in four nymphal stages of Aleurodicus dispersus based on scanning electron microscopy. There were significant differences found in shape and length of the antennae, and differences in type, number, morphological structure and distributional pattern of antennal sensilla in the four nymphal stages of A. dispersus. We found two types of sensilla on the antennae of first-instar nymph, three types on the third-instar nymphal antennae, four types on the second-instar and seven types on the fourth-instar nymphal antennae. Sensilla trichoidea (ST) and elevated sensilla placodea were found on the antennae of each nymphal stage, sensilla chaetica only occurred on the antennae of fourth-instar nymph. Sensilla furcatea occurred on the antennae of second- and third-instar nymphs, and sensilla basiconica were found on the antennae of second- and fourth-instar nymphs. In addition, there were sensilla campaniform and sensilla coeloconica found only on the antennae of fourth-instar nymph, whereas the ST of fourth-instar nymphs included sensilla trichoidea 1 and sensilla trichoidea 2. The possible functions of antennal sensilla are discussed. Our results contribute to a better understanding of the development of the olfactory system of whitefly nymphal stages, and provide a basis for further exploration of chemical communication mechanisms between whiteflies and host plants.


Assuntos
Antenas de Artrópodes/ultraestrutura , Hemípteros/ultraestrutura , Sensilas/ultraestrutura , Animais , Antenas de Artrópodes/crescimento & desenvolvimento , Hemípteros/crescimento & desenvolvimento , Microscopia Eletrônica de Varredura , Ninfa/anatomia & histologia , Ninfa/crescimento & desenvolvimento , Ninfa/ultraestrutura
6.
Mol Cell Biol ; 19(5): 3561-70, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10207079

RESUMO

The 3' end of histone mRNA is formed by an endonucleolytic cleavage of the primary transcript after a conserved stem-loop sequence. The cleavage reaction requires at least two trans-acting factors: the stem-loop binding protein (SLBP), which binds the stem-loop sequence, and the U7 snRNP that interacts with a sequence downstream from the cleavage site. Removal of SLBP from a nuclear extract abolishes 3'-end processing, and the addition of recombinant SLBP restores processing activity of the depleted extract. To determine the regions of human SLBP necessary for 3' processing, various deletion mutants of the protein were tested for their ability to complement the SLBP-depleted extract. The entire N-terminal domain and the majority of the C-terminal domain of human SLBP are dispensable for processing. The minimal protein that efficiently supports cleavage of histone pre-mRNA consists of 93 amino acids containing the 73-amino-acid RNA-binding domain and 20 amino acids located immediately next to its C terminus. Replacement of these 20 residues with an unrelated sequence in the context of the full-length SLBP reduces processing >90%. Coimmunoprecipitation experiments with the anti-SLBP antibody demonstrated that SLBP and U7 snRNP form a stable complex only in the presence of pre-mRNA substrates containing a properly positioned U7 snRNP binding site. One role of SLBP is to stabilize the interaction of the histone pre-mRNA with U7 snRNP.


Assuntos
Histonas/genética , Proteínas Nucleares , Precursores de RNA/genética , Proteínas de Ligação a RNA/metabolismo , Ribonucleoproteínas Nucleares Pequenas/metabolismo , Fatores de Poliadenilação e Clivagem de mRNA , Animais , Sítios de Ligação , Humanos , Camundongos , Mutação , Conformação de Ácido Nucleico , Ligação Proteica , Processamento Pós-Transcricional do RNA/genética , Proteínas de Ligação a RNA/genética , Proteínas Recombinantes/genética , Deleção de Sequência
7.
Mol Cell Biol ; 20(12): 4188-98, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10825184

RESUMO

The expression of the replication-dependent histone mRNAs is tightly regulated during the cell cycle. As cells progress from G(1) to S phase, histone mRNA levels increase 35-fold, and they decrease again during G(2) phase. Replication-dependent histone mRNAs are the only metazoan mRNAs that lack polyadenylated tails, ending instead in a conserved stem-loop. Much of the cell cycle regulation is posttranscriptional and is mediated by the 3' stem-loop. A 31-kDa stem-loop binding protein (SLBP) binds the 3' end of histone mRNA. The SLBP is necessary for pre-mRNA processing and accompanies the histone mRNA to the cytoplasm, where it is a component of the histone messenger RNP. We used synchronous CHO cells selected by mitotic shakeoff and HeLa cells synchronized at the G(1)/S or the M/G(1) boundary to study the regulation of SLBP during the cell cycle. In each system the amount of SLBP is regulated during the cell cycle, increasing 10- to 20-fold in the late G(1) and then decreasing in the S/G(2) border. SLBP mRNA levels are constant during the cell cycle. SLBP is regulated at the level of translation as cells progress from G(1) to S phase, and the protein is rapidly degraded as they progress into G(2). Regulation of SLBP may account for the posttranscriptional component of the cell cycle regulation of histone mRNA.


Assuntos
Ciclo Celular , Proteínas Nucleares/metabolismo , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/metabolismo , Animais , Células CHO , Cricetinae , Replicação do DNA , Histonas/genética , Histonas/metabolismo , Proteínas Nucleares/genética , Biossíntese de Proteínas , Processamento de Proteína Pós-Traducional , RNA Mensageiro/genética , Proteínas de Ligação a RNA/genética
8.
Chem Phys Lipids ; 76(2): 135-44, 1995 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-7634362

RESUMO

The propensity of hexagonal II phase formation plays an important role in the activity of mitochondrial ubiquinol-cytochrome c reductase or H(+)-ATPase. The respiratory control ratio of reconstituted ubiquinol-cytochrome c reductase or the ATP-induced membrane potential of reconstituted H(+)-ATPase became higher as the non-bilayer phospholipid phosphatidylethanolamine content of proteoliposomes increased. The highest respiratory control ratio or ATP-induced membrane potential was obtained in the case of 60-80% phosphatidylethanolamine-containing proteoliposomes. Dioleoylphosphatidylethanolamine could significantly enhance the respiratory control ratio of ubiquinol-cytochrome c reductase and ATP-induced membrane potential of H(+)-ATPase, while no obvious change could be observed when dielaidoylphosphatidylethanolamine was used. The bilayer to hexagonal II phase transition temperature of ubiquinol-cytochrome c reductase-containing proteoliposomes reconstituted with phosphatidylcholine+phosphatidylethanolamine increases with decreasing content of phosphatidylethanolamine. Several additives such as the bilayer stabilizers, cholesterol 3-sulfate and carbobenzoxy-D-Phe-L-PheGly, or hexagonal II phase-forming promoters, such as diolein or eicosane, can decrease or increase the activity of these two enzyme complexes.


Assuntos
Complexo III da Cadeia de Transporte de Elétrons/metabolismo , Mitocôndrias Cardíacas/enzimologia , ATPases Translocadoras de Prótons/metabolismo , Trifosfato de Adenosina/farmacologia , Animais , Carbonil Cianeto p-Trifluormetoxifenil Hidrazona/farmacologia , Ésteres do Colesterol/farmacologia , Dicroísmo Circular , Complexo III da Cadeia de Transporte de Elétrons/antagonistas & inibidores , Fluorometria , Concentração de Íons de Hidrogênio , Bicamadas Lipídicas/metabolismo , Lipossomos/química , Lipídeos de Membrana/química , Lipídeos de Membrana/metabolismo , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , Fosfatidilcolinas/análise , Fosfatidilcolinas/química , Fosfatidiletanolaminas/análise , Fosfatidiletanolaminas/química , Proteolipídeos/química , ATPases Translocadoras de Prótons/antagonistas & inibidores , Suínos , Temperatura
9.
Yao Xue Xue Bao ; 36(4): 307-9, 2001 Apr.
Artigo em Zh | MEDLINE | ID: mdl-12580063

RESUMO

AIM: To elucidate the mechanism of taurine-regulated amino acid release from synaptosomes. METHODS: Endogenous aspartate, glutamate and GABA release from cortical synaptosomes were measured by high performance liquid chromatography using stepwise elution system, Glutamate release was monitored by continuous fluorometry. RESULTS: 4-Aminopyridine (3.0 x 10(-2) mol.L-1) counteracted the taurine-induced inhibition of glutamate overflow (P < 0.05), while aspartate and GABA release was not affected. Nimodipine (10(-5) mol.L-1) combined with 4-aminopyridine was shown to decrease glutamate release (P < 0.05). CONCLUSION: Taurine may regulate glutamate release through presynaptic L-type calcium channel and also act on Asp- and GABA-nereve terminal to regulate Asp and GABA release in rat cortex.


Assuntos
4-Aminopiridina/farmacologia , Córtex Cerebral/metabolismo , Ácido Glutâmico/metabolismo , Taurina/antagonistas & inibidores , Animais , Ácido Aspártico/metabolismo , Feminino , Masculino , Bloqueadores dos Canais de Potássio/farmacologia , Ratos , Ratos Sprague-Dawley , Sinaptossomos/metabolismo , Ácido gama-Aminobutírico/metabolismo
10.
Neotrop Entomol ; 43(5): 409-14, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27193950

RESUMO

In recent years, light traps with light-emitting diodes (LEDs) have been widely used in integrated pest management. The spiralling whitefly, Aleurodicus dispersus Russell, a highly invasive pest which causes heavy damage to fruit trees and ornamental plants, exhibits positive phototaxis, and light trap is the most appropriate tool for monitoring. We evaluated the use of LEDs as an inexpensive light source and examined the relationship between the captured number and the population density of adult A. dispersus in the field. We found that the violet (405 nm) LED traps captured the most adults of A. dispersus, and the captured numbers were significantly higher than those of blue (460 nm), green (520 nm), yellow (570 nm), and red (650 nm) LED traps. The adults of A. dispersus captured by light traps equipped with violet LEDs and smeared with liquid paraffin had a significant positive correlation with the population density of adult A. dispersus in a guava orchard, with a correlation coefficient of 0.828. In general, the light traps with 15 violet LED bulbs hung into 550-mL plastic bottles and smeared with liquid paraffin were the portable devices for attraction of adult A. dispersus. The results have potential use for improving the efficiency of light traps at attracting and trapping the adult spiralling whitefly.


Assuntos
Hemípteros , Luz , Controle de Pragas , Animais , Densidade Demográfica
11.
Int J Neurosci ; 32(3-4): 747-56, 1987 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-3596920

RESUMO

Three paradigms of CNV were recorded on twelve subjects aged 19 to 23, as follows: (1) Usual CNV (U.CNV): warning stimulus--imperative stimulus--motor response. (2) Nonmotor Two-Level CNV (NmTL.CNV): warning stimulus--warning stimulus--weak click (random presence or absence)--discrimination. (3) Nonmotor CNV (Nm.CNV): warning stimulus--weak click (random presence or absence)--discrimination. The CNV rise, level by level, was observed. Analysis of the results of this experiment indicates that the positive wave after discrimination is essentially different from the positive-going wave after the usual CNV motor response. It is a pure, mental-related wave and is related to the extrication from mental load (EML). These phenomena suggest that the psychological factors in CNV are the increase of mental load which is synthetically composed of expectancy, conation, motivation, orientation, attention and arousal, etc., while engaging in an identical task.


Assuntos
Percepção Auditiva/fisiologia , Variação Contingente Negativa , Discriminação Psicológica/fisiologia , Eletrofisiologia , Desempenho Psicomotor/fisiologia , Adulto , Atenção/fisiologia , Feminino , Humanos , Masculino , Motivação/fisiologia , Psicologia , Tempo de Reação/fisiologia
12.
Biochemistry ; 36(19): 5827-36, 1997 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-9153423

RESUMO

The poly(ethylene glycol) (PEG)-induced fusion of sonicated, unilamellar vesicles (SUV) and large, unilamellar vesicles (LUV) composed of a variety of phosphatidylcholine species was compared using two assays for the mixing and leakage of internal vesicle contents. In the first [Lentz et al. (1992) Biochemistry, 31, 2643], disodium 8-aminonaphthalene-1,3,6-trisulfonate (ANTS) fluorescence is quenched by co-encapsulated N,N'-p-xylylenebis(pyridinium bromide) (DPX). For this assay, interference by the fluorescence of impurities in PEG demands that the PEG content of the sample be reduced by dilution before measurements are taken. The second assay [Viguera et al. (1993) Biochemistry, 32, 3708] monitors the fluorescence of Tb3+ complexed with dipicolinic acid (DPA) directly in concentrated PEG solutions. The two assays gave identical fusion profiles for egg PC SUVs treated with increasing concentrations of PEG, demonstrating that fusion occurs in the dehydrated state in the presence of PEG and does not require dilution. Comparison of results obtained with lipid species of varying degrees of unsaturation incorporated into either SUV or LUV suggested that acyl chain unsaturation and high membrane curvature combine to favor fusion of pure phosphatidylcholine membranes. There was a clear correlation between the fluorescence lifetime or the order parameter of the membrane probe 1-(4-trimethylammonium)-6-phenyl-1,3,5-hexatriene (TMA-DPH) in different membranes and the concentration of PEG needed to induce fusion of these membranes. However, the ratios of TMA-DPH lifetimes measured in D2O versus H2O buffers were the same for different lipid species, indicating that probe penetration was not very different for different lipid species. The results suggest that the combined effect of high membrane curvature and extensive chain unsaturation is an enhanced rate of lipid motion in the upper region of the bilayer, reflective of decreased packing density in the outer leaflet of unsaturated SUV bilayers, probably allowing for enhanced water penetration leading to an enhanced probability of fusion.


Assuntos
Ácidos Graxos Insaturados/metabolismo , Bicamadas Lipídicas/metabolismo , Fusão de Membrana/efeitos dos fármacos , Polietilenoglicóis/farmacologia , Difenilexatrieno/análogos & derivados , Ácidos Graxos Insaturados/química , Corantes Fluorescentes , Bicamadas Lipídicas/química , Fosfatidilcolinas , Ácidos Picolínicos , Térbio
13.
Biochemistry ; 36(8): 2076-83, 1997 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-9047306

RESUMO

Small, unilamellar vesicles (SUV) or large, unilamellar vesicles (LUV) containing a small amount of N-(7-nitro-2,1,3-benzoxadiazol-4-yl)phosphatidylethanolamine (NBD-PE) or the corresponding phosphatidylserine (NBD-PS) were made asymmetric in labeled lipid by reduction of outer leaflet probe with externally added sodium dithionite. Following removal of dithionite, transbilayer lipid redistribution (presumably due to lipid flip-flop) was indicated by a loss of fluorescence intensity upon readdition of dithionite. Vesicle rupture and fusion in the presence of PEG were measured by changes in the fluorescence of trapped Tb3+ complexed with dipicolinic acid (DPA) or by the increase of fluorescence from 8-aminonaphthalene-1,3,6-trisulfonic acid (ANTS) coencapsulated with a quenching agent. NBD-PE redistributed slowly (approximately 2%/h) in all symmetrically labeled vesicles examined, while NBD-PS did not. NBD-PE redistribution was not accelerated by treatment of vesicles with PEG below concentrations that induced vesicle rupture or fusion, but was enhanced at or above these PEG concentrations. SUV prepared from hen egg yolk phosphatidylcholine (egg PC) or from dioleoylphosphatidylcholine (DOPC)/dilinolenoylphosphatidylcholine (diC(18:3)PC) (85/15) mixtures were shown to fuse without rupturing in the presence of appropriate concentrations of PEG. Matching the osmolalities inside and outside the vesicle mitigated against rupture but did not prevent fusion. Under these conditions, NBD-PE flip-flop was proportional to the amount of fusion, but with different proportionality constants for the two lipid systems, while NBD-PS flip-flop did not occur. Redistribution of total mass from the outer to the inner leaflet during the fusion process could be detected in terms of a change in the ratio of dithionite-reducible probe to total probe. Both probes detected inwardly directed redistribution of lipid mass under conditions that induced fusion of SUV. We conclude that inward mass redistribution must accompany PEG-mediated SUV fusion, but that lipid flip-flop is not mechanistically related to the fusion process.


Assuntos
Bicamadas Lipídicas/metabolismo , Fusão de Membrana , Polietilenoglicóis
14.
Immunity ; 9(3): 305-13, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9768750

RESUMO

Clonal selection theories postulate that lymphocyte fate is regulated by antigen receptor specificity. However, lymphocyte apoptosis is induced through nonantigen-specific receptors such as Fas (CD95/APO-1) or TNFR. We define a selective TCR that controls apoptosis by Fas or TNFR stimulation. Variant ligands can deliver this "competence to die" signal without the full TCR signals necessary for cytokine synthesis. These partial agonists regulate T cell deletion in vivo even when Fas or TNF is provided by T cells of unrelated specificity, but they do not cause the liver necrosis that is associated with T cell elimination by the full agonist. Thus, selective signaling ligands regulate T cell deletion and immune damage in vivo and may be important for peripheral T cell tolerance.


Assuntos
Antígenos/imunologia , Apoptose/imunologia , Imunidade Celular/imunologia , Receptores de Antígenos de Linfócitos T/fisiologia , Linfócitos T/fisiologia , Animais , Apresentação de Antígeno , Antígenos/farmacologia , Apoptose/efeitos dos fármacos , Comunicação Celular/imunologia , Morte Celular , Células Cultivadas , Células Clonais/citologia , Células Clonais/efeitos dos fármacos , Células Clonais/fisiologia , Proteína Ligante Fas , Feminino , Fígado/patologia , Ativação Linfocitária/imunologia , Glicoproteínas de Membrana/fisiologia , Camundongos , Camundongos Endogâmicos , Necrose , Peptídeos/agonistas , Peptídeos/imunologia , Peptídeos/farmacologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Linfócitos T/citologia , Linfócitos T/efeitos dos fármacos , Fator de Necrose Tumoral alfa/fisiologia
15.
J Biol Chem ; 275(39): 30378-86, 2000 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-10893414

RESUMO

Nuclear autoantigenic sperm protein (NASP), initially described as a highly autoimmunogenic testis and sperm-specific protein, is a histone-binding protein that is a homologue of the N1/N2 gene expressed in oocytes of Xenopus laevis. Here, we report a somatic form of NASP (sNASP) present in all mitotic cells examined, including mouse embryonic cells and several mouse and human tissue culture cell lines. Affinity chromatography and histone isolation demonstrate that NASP from myeloma cells is complexed only with H1, linker histones. Somatic NASP is a shorter version of testicular NASP (tNASP) with two deletions in the coding region arising from alternative splicing and differs from tNASP in its 5' untranslated regions. We examined the relationship between NASP mRNA expression and the cell cycle and report that in cultures of synchronized mouse 3T3 cells and HeLa cells sNASP mRNA levels increase during S-phase and decline in G(2), concomitant with histone mRNA levels. NASP protein levels remain stable in these cells but become undetectable in confluent cultures of nondividing CV-1 cells and in nonmitotic cells in various body tissues. Expression of sNASP mRNA is regulated during the cell cycle and, consistent with a role as a histone transport protein, NASP mRNA expression parallels histone mRNA expression.


Assuntos
Autoantígenos/metabolismo , Proteínas de Transporte/metabolismo , Ciclo Celular/fisiologia , Proteínas Cromossômicas não Histona , Histonas/metabolismo , Proteínas Nucleares/metabolismo , Sequência de Aminoácidos , Animais , Autoantígenos/genética , Sequência de Bases , Proteínas de Ciclo Celular , Regulação da Expressão Gênica , Biblioteca Gênica , Humanos , Masculino , Camundongos , Dados de Sequência Molecular , Proteínas Nucleares/genética , Homologia de Sequência do Ácido Nucleico , Distribuição Tecidual
16.
Nat Mater ; 3(10): 673-6, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15359345

RESUMO

Since the discovery of carbon nanotubes in 1991 by Iijima, there has been great interest in creating long, continuous nanotubes for applications where their properties coupled with extended lengths will enable new technology developments. For example, ultralong nanotubes can be spun into fibres that are more than an order of magnitude stronger than any current structural material, allowing revolutionary advances in lightweight, high-strength applications. Long metallic nanotubes will enable new types of micro-electromechanical systems such as micro-electric motors, and can also act as a nanoconducting cable for wiring micro-electronic devices. Here we report the synthesis of 4-cm-long individual single-wall carbon nanotubes (SWNTs) at a high growth rate of 11 microm s(-1) by catalytic chemical vapour deposition. Our results suggest the possibility of growing SWNTs continuously without any apparent length limitation.


Assuntos
Nanotubos de Carbono/química , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura , Análise Espectral Raman
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