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1.
Nature ; 607(7919): 468-473, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35859194

RESUMO

Quantum many-body systems away from equilibrium host a rich variety of exotic phenomena that are forbidden by equilibrium thermodynamics. A prominent example is that of discrete time crystals1-8, in which time-translational symmetry is spontaneously broken in periodically driven systems. Pioneering experiments have observed signatures of time crystalline phases with trapped ions9,10, solid-state spin systems11-15, ultracold atoms16,17 and superconducting qubits18-20. Here we report the observation of a distinct type of non-equilibrium state of matter, Floquet symmetry-protected topological phases, which are implemented through digital quantum simulation with an array of programmable superconducting qubits. We observe robust long-lived temporal correlations and subharmonic temporal response for the edge spins over up to 40 driving cycles using a circuit of depth exceeding 240 and acting on 26 qubits. We demonstrate that the subharmonic response is independent of the initial state, and experimentally map out a phase boundary between the Floquet symmetry-protected topological and thermal phases. Our results establish a versatile digital simulation approach to exploring exotic non-equilibrium phases of matter with current noisy intermediate-scale quantum processors21.

2.
Phys Rev Lett ; 128(1): 013603, 2022 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-35061449

RESUMO

Controllable Rydberg atom arrays have provided new insights into fundamental properties of quantum matter both in and out of equilibrium. In this work, we study the effect of experimentally relevant positional disorder on Rydberg atoms trapped in a 2D square lattice under antiblockade (facilitation) conditions. We show that the facilitation conditions lead the connectivity graph of a particular subspace of the full Hilbert space to form a 2D Lieb lattice, which features a singular flat band. Remarkably, we find three distinct regimes as the disorder strength is varied: a critical regime, a delocalized but nonergodic regime, and a regime with a disorder-induced flat band. The critical regime's existence depends crucially upon the singular flat band in our model, and is absent in any 1D array or ladder system. We propose to use quench dynamics to probe the three different regimes experimentally.

3.
Front Public Health ; 9: 646770, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33996724

RESUMO

Background: The Covid-19 pandemic restricts children and adolescents from doing normal daily activities such as playing outdoors and going to school. The incidence and prevalence of myopia have increased during the COVID-19 pandemic. The aim of this study was to investigate and evaluate the impact of the home confinement during the COVID-19 pandemic on the progression of myopia among children and adolescents in Chongqing, China. Methods: The survey was conducted by using stratified samplings. Samples were randomly selected from the 2019 National Student Physique and Health Survey database, and their visual function and refractive data were compared with those in 2020. Vision-related behavior questionnaire including digital screen exposure was applied to investigate the correlation between eye parameter and eye health-related behavior. Results: A total of 1,733 and 1,728 students were enrolled in 2020 and 2019, respectively. The percentage of myopia students was 55.02% in 2020, which was higher than that in 2019 (44.62%). The mean uncorrected visual acuity (UCVA, LogMAR, 0.35 ± 0.42) in 2020 was higher than that in 2019 (0.27 ± 0.36, P < 0.001). The mean spherical equivalent (SE) refraction (-1.94 ± 2.13 D) in 2020 was lower than that in 2019 (-1.64 ± 5.49 D, P < 0.001). For students who used digital devices for online courses, the mean SE in the television group (-1.10 ± 1.49 D) was better than that in the computer group (-2.03 ± 2.37 D, P = 0.0017) and in the cell phone group (-2.02 ± 2.09 D, P = 0.0028). The average duration of online classes (r = -0.27, P < 0.0001), the number of online classes per day (r = -0.33, P < 0.0001), as well as digital screen exposure time (r = -0.20, P < 0.0001) were negatively correlated with SE, and the average time of outdoor activity (r = 0.20, P < 0.0001) was positively correlated with SE. Conclusions: Increased digital screen exposure contributes to myopic progression in children and adolescents of Chongqing during the COVID-19 pandemic. Suitable digital devices should be provided for online classes and outdoor activity should be advocated to prevent myopic pandemic.


Assuntos
COVID-19 , Miopia , Adolescente , Criança , China/epidemiologia , Humanos , Miopia/epidemiologia , Pandemias , SARS-CoV-2 , Inquéritos e Questionários
4.
Proc Natl Acad Sci U S A ; 117(41): 25396-25401, 2020 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-33024018

RESUMO

Quantum computers and simulators may offer significant advantages over their classical counterparts, providing insights into quantum many-body systems and possibly improving performance for solving exponentially hard problems, such as optimization and satisfiability. Here, we report the implementation of a low-depth Quantum Approximate Optimization Algorithm (QAOA) using an analog quantum simulator. We estimate the ground-state energy of the Transverse Field Ising Model with long-range interactions with tunable range, and we optimize the corresponding combinatorial classical problem by sampling the QAOA output with high-fidelity, single-shot, individual qubit measurements. We execute the algorithm with both an exhaustive search and closed-loop optimization of the variational parameters, approximating the ground-state energy with up to 40 trapped-ion qubits. We benchmark the experiment with bootstrapping heuristic methods scaling polynomially with the system size. We observe, in agreement with numerics, that the QAOA performance does not degrade significantly as we scale up the system size and that the runtime is approximately independent from the number of qubits. We finally give a comprehensive analysis of the errors occurring in our system, a crucial step in the path forward toward the application of the QAOA to more general problem instances.

5.
Geriatr Nurs ; 41(6): 863-871, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32571584

RESUMO

This systematic review sought to evaluate the effectiveness of non-facilitated meaningful activities for older people with dementia in long-term care facilities. Searches were conducted in PubMed; CINAHL; EMBASE; Web of science; PsycINFO; Cochrane; ProQuest; and ClinicalTrials.gov to identify articles published between January 2004 and October 2019. A total of six studies were included. Results implied that current randomised controlled trials or controlled trials about non-facilitated meaningful activities for people with living dementia in long-term care facilitates are limited, but those included in this review were of adequate methodological quality. Meaningful non-facilitated activities, such as music, stimulated family presence, animal-like social robot PARO/plush toy and lifelike dolls, may have beneficial effects on agitation, emotional well-being, feelings of pleasure, engagement, and sleep quality. However, there remains a lack of conclusive and robust evidence to support these psychological and physiological effects of non-facilitated meaningful activities for older people with dementia living in long-term care facilities by care staff.


Assuntos
Demência , Robótica , Idoso , Animais , Humanos , Assistência de Longa Duração , Casas de Saúde , Interação Social
6.
Phys Rev Lett ; 124(20): 207602, 2020 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-32501079

RESUMO

We study one-dimensional spin-1/2 models in which strict confinement of Ising domain walls leads to the fragmentation of Hilbert space into exponentially many disconnected subspaces. Whereas most previous works emphasize dipole moment conservation as an essential ingredient for such fragmentation, we instead require two commuting U(1) conserved quantities associated with the total domain-wall number and the total magnetization. The latter arises naturally from the confinement of domain walls. Remarkably, while some connected components of the Hilbert space thermalize, others are integrable by Bethe ansatz. We further demonstrate how this Hilbert-space fragmentation pattern arises perturbatively in the confining limit of Z_{2} gauge theory coupled to fermionic matter, leading to a hierarchy of timescales for motion of the fermions. This model can be realized experimentally in two complementary settings.

7.
Diagn Pathol ; 15(1): 55, 2020 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-32408908

RESUMO

BACKGROUND: Circular RNAs (circRNAs) have been demonstrated to exert crucial mediators in tumor initiation and development. Nevertheless, the roles of circKIF4A in breast cancer (BC) are still not very clear. METHODS: Quantitative real-time polymerase chain reaction (qRT-PCR) was conducted to determine the expression of circKIF4A, miR-152, zinc finger E-box binding homeobox 1 (ZEB1) mRNA and caspase-3. Western blot assay was utilized to examine the protein level of ZEB1. Transwell assay and flow-cytometric analysis were adopted for the evaluation of cell migration, invasion and apoptosis, respectively. The associations among circKIF4A, miR-152 and ZEB1 were predicted by online websites and verified by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. RESULTS: CircKIF4A and ZEB1 were conspicuously upregulated and miR-152 was markedly reduced in BC tissues and cells. Deficiency of circKIF4A repressed migration, invasion and induced apoptosis of BC cells. Moreover, circKIF4A was confirmed to be a sponge of miR-152 and miR-152 could bind to ZEB1. MiR-152 inhibition or ZEB1 overexpression abolished the impacts of circKIF4A knockdown on cell migration, invasion and apoptosis in BC. CONCLUSION: Silencing of circKIF4A hampered cell metastasis and promoted apoptosis by regulating ZEB1 via sponging miR-152 in BC.


Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/patologia , MicroRNAs/genética , Homeobox 1 de Ligação a E-box em Dedo de Zinco/genética , Adulto , Idoso , Apoptose/genética , Movimento Celular/genética , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Pessoa de Meia-Idade , Invasividade Neoplásica/genética , Transdução de Sinais/genética
8.
Phys Rev B ; 102(1)2020.
Artigo em Inglês | MEDLINE | ID: mdl-34131609

RESUMO

String breaking is a central dynamical process in theories featuring confinement, where a string connecting two charges decays at the expense of the creation of new particle-antiparticle pairs. Here, we show that this process can also be observed in quantum Ising chains where domain walls get confined either by a symmetry-breaking field or by long-range interactions. We find that string breaking occurs, in general, as a two-stage process. First, the initial charges remain essentially static and stable. The connecting string, however, can become a dynamical object. We develop an effective description of this motion, which we find is strongly constrained. In the second stage, which can be severely delayed due to these dynamical constraints, the string finally breaks. We observe that the associated timescale can depend crucially on the initial separation between domain walls and can grow by orders of magnitude by changing the distance by just a few lattice sites. We discuss how our results generalize to one-dimensional confining gauge theories and how they can be made accessible in quantum simulator experiments such as Rydberg atoms or trapped ions.

9.
Aging Ment Health ; 24(2): 349-352, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-30621436

RESUMO

Objectives: To explore the feasibility of using the video-conferencing program, Skype, on iPads with older adults living in long-term care (LTC) facilities.Method: Using a mixed-method design, six residents from one LTC facility in Queensland, Australia participated in a one-off interactive intervention session, followed by post-session semi-structured interviews. The intervention session involved a 15-minutes training session in using Skype, and 30-minutes interactive practise in making and receiving a call using Skype. Residents were interviewed after the intervention session to explore their experience and perceptions of using Skype on the iPad. Reflections about the intervention session were written as study notes by the research team. Qualitative data were analysed using an inductive, thematic analytic approach.Results: Four broad themes emerged: (1) Video-conferencing on iPads is inhibited by age-related cognitive decline and physical frailty; (2) Video-conferencing is an unfamiliar technology for many older residents, and practice and staff assistance are required; (3) Video-conferencing is regarded positively, and seen as a good way of communicating with family/friends; and (4) Use of video-conferencing highlights general concerns held about privacy and cyber security issues.Conclusion: Without adequate staff assistance, video-conferencing via iPads may be challenging for an older population in LTC. Alternatives such as telepresence robots may assist with these challenges.


Assuntos
Atitude Frente aos Computadores , Computadores de Mão , Demência/terapia , Consulta Remota , Idoso , Idoso de 80 Anos ou mais , Austrália , Demência/psicologia , Estudos de Viabilidade , Feminino , Humanos , Entrevistas como Assunto , Assistência de Longa Duração , Masculino , Cuidados de Enfermagem/métodos , Casas de Saúde , Pesquisa Qualitativa , Encaminhamento e Consulta , Telemedicina
10.
J BUON ; 24(2): 622-627, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31128015

RESUMO

PURPOSE: Hepatocellular carcinoma causes considerable mortality and no efficient chemotherapy is available. Novel molecules of plant origin may prove beneficial in the development of therapy of hepatocellular carcinoma. In this study we examined the anticancer effects of Tanshindiol-C (TC) against the hepatocellular carcinoma SNU-4235 cell line. METHODS: Proliferation rate of the SNU-2435 cells was determined by MTT assay. Apoptosis was confirmed by DAPI and annexin V/PI staining. Cell cycle analysis was performed by flow cytometry. MicroRNA expression was checked by qRT-PCR and protein expression by western blotting. The in vivo evaluation of TC was performed in xenografted mice models. RESULTS: TC inhibited the growth of the SNU-4235 cells and exhibited an IC50 of 20 µM. Investigation of the underlying mechanism revealed that TC triggered apoptotic death of the SNU-4235 cells which was also associated with enhancement of the expression of Bax and decrease in the expression of Bcl-2. TC also caused arrest of the cells in the G2/M phase of the cell cycle and also exerted angiogenitic effects. TC also enhanced the expression of the tumor suppressor microRNA-21, 222 and 31. In vivo evaluation of TC revealed that it could inhibit the tumor weight volume, suggestive of the anticancer potential of TC. CONCLUSIONS: In brief, tanshindiol-C exerts anticancer effects on hepatocellular carcinoma by induction of apoptosis and cell cycle arrest, along with inhibiting the angiogenesis and the expression of tumor suppressive microRNAs. TC could also inhibit the growth of the xenografted tumors and hence could prove to be a potential anticancer agent.


Assuntos
Carcinoma Hepatocelular/tratamento farmacológico , Diterpenos/farmacologia , Neoplasias Hepáticas/tratamento farmacológico , Neovascularização Patológica/tratamento farmacológico , Compostos Fitoquímicos/farmacologia , Animais , Apoptose/efeitos dos fármacos , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Potencial da Membrana Mitocondrial , Camundongos , MicroRNAs/genética , Neovascularização Patológica/genética , Neovascularização Patológica/patologia , Proteínas Proto-Oncogênicas c-bcl-2/genética , Ensaios Antitumorais Modelo de Xenoenxerto , Proteína X Associada a bcl-2/genética
11.
Phys Rev Lett ; 122(15): 150601, 2019 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-31050545

RESUMO

We study the quasiparticle excitation and quench dynamics of the one-dimensional transverse-field Ising model with power-law (1/r^{α}) interactions. We find that long-range interactions give rise to a confining potential, which couples pairs of domain walls (kinks) into bound quasiparticles, analogous to mesonic states in high-energy physics. We show that these quasiparticles have signatures in the dynamics of order parameters following a global quench, and the Fourier spectrum of these order parameters can be exploited as a direct probe of the masses of the confined quasiparticles. We introduce a two-kink model to qualitatively explain the phenomenon of long-range-interaction-induced confinement and to quantitatively predict the masses of the bound quasiparticles. Furthermore, we illustrate that these quasiparticle states can lead to slow thermalization of one-point observables for certain initial states. Our work is readily applicable to current trapped-ion experiments.

12.
Phys Rev Lett ; 121(25): 250404, 2018 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-30608853

RESUMO

We study the nonequilibrium dynamics of Abelian anyons in a one-dimensional system. We find that the interplay of anyonic statistics and interactions gives rise to spatially asymmetric particle transport together with a novel dynamical symmetry that depends on the anyonic statistical angle and the sign of interactions. Moreover, we show that anyonic statistics induces asymmetric spreading of quantum information, characterized by asymmetric light cones of out-of-time-ordered correlators. Such asymmetric dynamics is in sharp contrast to the dynamics of conventional fermions or bosons, where both the transport and information dynamics are spatially symmetric. We further discuss experiments with cold atoms where the predicted phenomena can be observed using state-of-the-art technologies. Our results pave the way toward experimentally probing anyonic statistics through nonequilibrium dynamics.

13.
Gynecol Obstet Invest ; 81(5): 416-23, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26808725

RESUMO

PURPOSE: This study assessed the clinical significance of c-myc gene copy number gain detected by fluorescence in situ hybridization (FISH) in the prediction of cervical intraepithelial neoplasia (CIN) progression. METHODS: We retrospectively investigated 140 Thinprep cytologic test (TCT) specimens that were histopathologically diagnosed with various stages of cervical neoplasia or malignancy. The specimens were subjected to TCT, human papillomavirus (HPV) testing, and FISH analysis with a c-myc-specific probe. The diagnostic reliability of these methods in determining progression was assessed according to sensitivity, specificity, and κ coefficients. RESULTS: The gene copy number gain of c-myc was significantly higher in the cervical lesion of advanced histologic grade (p < 0.001). For CIN2+ lesions, the sensitivities of TCT, HPV DNA testing, and FISH analysis were 72.3, 92.1, and 64.5%, respectively; the specificities were 81.3, 57.8, and 93.8%, respectively (p < 0.001). The κ coefficients between the c-myc gene test and either the TCT or the HPV DNA test were 0.538 and 0.399, respectively (p < 0.001). CONCLUSIONS: FISH analysis of the c-myc oncogene could be a useful adjunct screening method for the early diagnosis of high-grade cervical lesions. Moreover, c-myc may be a new molecular biomarker for the early diagnosis of cervical lesion progression.


Assuntos
Carcinoma de Células Escamosas/patologia , Variações do Número de Cópias de DNA , Detecção Precoce de Câncer , Genes myc/genética , Neoplasias do Colo do Útero/patologia , Adulto , Idoso , Biomarcadores Tumorais/genética , Carcinoma de Células Escamosas/genética , Neoplasia Intraepitelial Cervical/genética , Neoplasia Intraepitelial Cervical/patologia , Técnicas Citológicas , Feminino , Marcadores Genéticos/genética , Humanos , Hibridização in Situ Fluorescente , Pessoa de Meia-Idade , Papillomaviridae/isolamento & purificação , Infecções por Papillomavirus/diagnóstico , Reprodutibilidade dos Testes , Estudos Retrospectivos , Neoplasias do Colo do Útero/genética , Adulto Jovem
14.
Chin Med J (Engl) ; 128(13): 1778-86, 2015 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-26112720

RESUMO

BACKGROUND: During the last 3 decades, China has dramatic changes of the dietary pattern among its citizens, particularly in urban cities. This study aimed to determine the nutrient intake status and factors associated with nutrient intakes of urban Chinese pregnant women now-a-day. METHODS: The multistage stratified random sampling method was applied in the cross-sectional study. 479 women in three trimesters of pregnancy from eight cities of China were recruited. Nutrient intakes were evaluated with one 24 h dietary recall, and compared with the Chinese Dietary Reference Intakes (DRIs) 2013 for available nutrients. RESULTS: Most pregnant women had imbalanced macronutrient distribution with excessive energy derived from fat. Intakes of Vitamin A, B 6, calcium, magnesium, and selenium were below Chinese Recommended Nutrient Intake (RNI) and Estimated Average Requirements (EARs) in all trimesters. Most pregnant women took more folic acid in the first trimester with a significant decrease in the second and third trimester (P < 0.05). Shortfall in iron intake was found in the third trimester whereas some women may be at the risk of excessive iron intake. Intakes of thiamin met RNI in the first trimester but were below EAR in all trimesters. Trimester phasing was positively associated with most nutrients (P < 0.05). Prepregnancy body mass index was inversely associated with energy, fat, Vitamin C, and calcium intake (P < 0.05). Educational level and household income were positively associated with folic acid intake (P < 0.05). CONCLUSIONS: Current prenatal dietary choices of urban pregnant women in China are imbalanced in the nutrient intake when compared with national DRIs 2013, particularly in intakes of energy derived from fat and micronutrients. Appropriate dietary advice to pregnant women should promote a balanced diet with emphasis on avoidance of foods of high fat content and incorporation of foods that are good sources of the key micronutrients that are usually lacking in a regular pregnancy diet. Further research is needed to understand the eating habits and food patterns that contribute to this imbalanced diet in order to be able to effectively improve prenatal women's nutrient intake status.


Assuntos
Comportamento Alimentar , Adulto , China , Cidades , Estudos Transversais , Ingestão de Energia/fisiologia , Feminino , Humanos , Necessidades Nutricionais , Estado Nutricional/fisiologia , Gravidez , Adulto Jovem
15.
Opt Express ; 23(3): 2383-91, 2015 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-25836106

RESUMO

We propose a scheme to directionally couple light into graphene plasmons by placing a graphene sheet on a magneto-optical substrate. When a magnetic field is applied parallel to the surface, the graphene plasmon dispersion relation becomes asymmetric in the forward and backward directions. It is possible to achieve unidirectional excitation of graphene plasmons with normally incident illumination by applying a grating to the substrate. The directionality can be actively controlled by electrically gating the graphene, or by varying the magnetic bias. This scheme may have applications in graphene-based opto-electronics and sensing.

16.
Wei Sheng Yan Jiu ; 44(6): 954-8, 2015 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-26738390

RESUMO

OBJECTIVE: To evaluate the effect of resveratrol on NF-E2-related factor 2 (Nrf2) signal pathway in the process of oxidative stress of mice brain tissue induced by chronic lead exposure. METHODS: A total of 48 healthy weaned C57BL/6 male mice were randomly divided into four groups (12 mice each group), control group, lead poisoning model group, lead poisoning coupled with resveratrol intervention group and resveratrol group. The lead poisoning mice model had been made by exposed to 0.2% lead acetate solution in the drinking water for 12 weeks. At the same time, the mice in the intervention group and resveratrol group were fed with resveratrol (50 mg/(kg · d)) by oral gavage and the other two groups were treated with the same volume of solvent, sodium carboxymethylcellulose. The serum and brain tissues were removed and used for detecting the lead concentration and measuring the activity of GSH-Px and the content of GSH and MDA. The levels of protein Nrf2 and γ-GCS were determined by western blot. RESULTS: Compared with the poisoning model group, GSH-Px activity and GSH content were significantly increased (P < 0.05), and MDA content was significantly decreased in the brain tissue intervened by resveratrol (P < 0.05). The protein expression of Nrf2 and γ-GCS were induced in the brain tissue of the intervention group (P < 0.05). CONCLUSION: Resveratrol could reduce the oxidation damage caused by chronic lead exposure in drinking water which may due to the protein activation of Nrf2, further up-regulated expression of targeting γ-GCS and adjusted dynamic balance of GSH system.


Assuntos
Encéfalo/metabolismo , Intoxicação por Chumbo , Fator 2 Relacionado a NF-E2/metabolismo , Transdução de Sinais/efeitos dos fármacos , Estilbenos/farmacologia , Animais , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Resveratrol
17.
J Trace Elem Med Biol ; 28(2): 227-232, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24582137

RESUMO

The objective of this study was to investigate the effects of lead exposure on spatial learning and memory capacity and the expression of amyloid ß and phosphorylated tau proteins in the mouse hippocampus. A total of 24 adult C57BL/6 mice (12 of each sex) were mated at a 1:1 ratio. After delivery, the litters were normalised to 6 pups per litter. During the lactation period, the pups were randomly separated into four groups: control, early exposure, late exposure, or long-term exposure. These groups were not exposed to lead, exposed to lead from birth to week 24, exposed to lead from week 24 to week 48, or exposed to lead from birth to 48 weeks of age, respectively. Lead exposure was induced by providing Pb-contaminated drinking water at a concentration of 0.1%. All of the pups were fed until 72 weeks of age, at which time their spatial learning and memory capacity was evaluated via the Morris water maze test. Then, the lead levels in their blood and hippocampus were measured via graphite furnace atomic absorption spectrometry. The protein expression of amyloid ß and phosphorylated tau in the hippocampus was detected via Western blot. The results revealed that the hippocampal and blood lead levels were significantly higher in all of the groups exposed to lead than the control group (P<0.05). The spatial learning and memory performances of the lead-exposed groups were much poorer than those of the control group (P<0.05). The expression levels of amyloid ß and phosphorylated tau proteins were increased in the lead-exposed groups compared to the control group (P<0.05). The enhanced expressions of amyloid ß and phosphorylated tau proteins might contribute to the impairment in spatial learning and memory in the lead-exposed mice.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Hipocampo/crescimento & desenvolvimento , Hipocampo/metabolismo , Chumbo/toxicidade , Estágios do Ciclo de Vida/efeitos dos fármacos , Proteínas tau/metabolismo , Animais , Western Blotting , Peso Corporal/efeitos dos fármacos , Feminino , Hipocampo/efeitos dos fármacos , Chumbo/sangue , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Memória/efeitos dos fármacos , Camundongos Endogâmicos C57BL , Fosforilação/efeitos dos fármacos , Aprendizagem Espacial/efeitos dos fármacos
18.
J Trace Elem Med Biol ; 28(1): 100-4, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23999228

RESUMO

OBJECTIVE: To investigate the effects of maternal lead (Pb) exposure on the learning and memory ability and expression of interleukin1-ß (IL1-ß), tumor necrosis factor (TNF-α) and beta amyloid protein (Aß) in cerebral cortex of mice offspring. METHODS: Pb exposure initiated from beginning of gestation to weaning. Pb acetate administered in drinking solutions was dissolved in distilled deionized water at the concentrations of 0.1%, 0.5% and 1% groups, respectively. On the PND21, the learning and memory ability were tested by water maze test and the Pb levels were also determined by graphite furnace atomic absorption spectrometry. The expression of IL1-ß, TNF-α and Aß in cerebral cortex was measured by immunohistochemistry and western blotting. RESULTS: The Pb levels in blood and cerebral cortex of all exposure groups were significantly higher than that of the control group (P<0.05). In water maze test, the performances of 0.5% and 1% groups were worse than that of the control group (P<0.05). The expression of IL1-ß, TNF-α and Aß was increased in Pb exposed groups than that of the control group (P<0.05). CONCLUSIONS: The high expression of IL1-ß, TNF-α and Aß in the cerebral cortex of pups may contribute to the impairment of learning and memory associated with maternal Pb exposure.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/metabolismo , Interleucina-1beta/metabolismo , Chumbo/toxicidade , Fator de Necrose Tumoral alfa/metabolismo , Animais , Feminino , Imuno-Histoquímica , Aprendizagem/efeitos dos fármacos , Exposição Materna/efeitos adversos , Memória/efeitos dos fármacos , Camundongos , Gravidez
19.
Opt Express ; 21(13): 15075-80, 2013 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-23842294

RESUMO

Dark surface waves with photorefractive diffusion and photovoltaic nonlinearities are predicted for the first time. We find it is extraordinary that this type of dark surface waves should be in self-focusing media, which is very different from the surface dark solitons or other nonlinear dark surface waves. An oscillator model is proposed by which the above extraordinary phenomenon is demonstrated. In this model an equivalent force function is established, whose form determines the varieties of surface waves (bright surface waves, dark surface waves or others).

20.
Se Pu ; 31(10): 1001-4, 2013 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-24432644

RESUMO

The structure of polysaccharide in traditional Chinese medicine (TCM) is complex and characteristic. A method of oligosaccharide electrophoresis analysis assisted with cluster analysis (CA) was established to simultaneously identify TCMs. Six TCMs from three families were selected as experimental subjects and their polysaccharides were extracted. The obtained oligosaccharides via incompletely degraded TCM polysaccharides were derivatized using 1-phenyl-3-methyl-5-pyrazolone (PMP). The PMP-oligosaccharide derivatives were separated and analyzed by capillary zone electrophoresis (CZE). The six TCMs were identified by the featured information of oligosaccharide electropherograms with CA. The electrophoresis conditions were as follows: uncoated fused silica capillary column (49 cm/40 cm (total length/effective length) x 50 microm); running buffer solution, 50 mmol/L phosphate buffer solution (pH 2.5); detection wavelength, 245 nm; operating voltage, 15 kV; hydrodynamic pressure injection, 10 cm x 4 s. The results showed that the six TCMs from three families were effectively identified by the method of TCM oligosaccharide electropherograms combined with CA. This method is a promising tool to identify TCM with good reliability and reproducibility.


Assuntos
Medicamentos de Ervas Chinesas/análise , Oligossacarídeos/análise , Polissacarídeos/análise , Antipirina/análogos & derivados , Edaravone , Eletroforese Capilar , Reprodutibilidade dos Testes
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