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1.
Phys Rev E ; 106(3): L032201, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36266887

RESUMO

While there are many physical processes showing subdiffusion and some useful particle models for understanding the underlying mechanisms have been established, a systematic study of subdiffusive energy transport is still lacking. Here we present convincing evidence that, in the range of system size investigated, the energy subdiffusion can take place in a Hamiltonian lattice system with both harmonic nearest-neighbor and anharmonic long-range interactions. In particular, we show that the interaction range dependence of antipersistent energy-current correlations are relevant to this special type of energy subdiffusion. The underlying mechanisms are related to the various scattering processes of phonons and discrete breathers. Our results shed light on understanding the extremely slow energy transport.

2.
Phys Rev E ; 101(4-1): 042207, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32422702

RESUMO

Managing thermal transport in nanostructured materials possesses both theoretical and application value in thermoelectric and microelectronics design. Though a suppressed thermal conductivity could be easily achieved through disorder-induced phonon scattering in a superlattice, it is challenging to enhance thermal transport in a periodically designed lattice. In this paper, we show the possibility of mediating thermal conductivity from a suppressed to an enhanced value in a Fermi-Pasta-Ulam ß superlattice with periodic cells of arithmetically increased nonlinearity. When the cell length is increased, thermal conductivity in the superlattice crosses over a suppressed region into an enhanced one and it is even higher than in a homogeneous lattice with the same nonlinearity strength. The mediation originates from the long-lived nonlinear wave packets as solitons across the disorder-induced interface between cells of the superlattice, while at the same time the normal vibrational modes as phonons are suppressed. Our result shows a promising strategy to manipulate thermal transport over a wide range in a superlattice with strong nonlinearity.

3.
Sci Rep ; 10(1): 6128, 2020 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-32273531

RESUMO

The simulation of overland flow, wherein runoff yield and concentration are influenced by topography, is fundamental to hydrological forecasting. Therefore, critically evaluating the characteristics of overland flow under the influence of topographic depressions-which are one of the most common microtopographic structures-is vital for improving current hydrological models. In this study, we developed a solution for the real-world application of overland flow simulations under the influence of depressions in hydrological models. A relative depression storage-outflow curve (RDOC) was proposed to investigate surface outflow processes. Experiments were conducted based on the variable-controlling approach using three rainfall return periods, four slopes, and four depression rates while ensuring a consistent initial soil moisture content. A homogenized RDOC was achieved based on shape analysis; it was parameterized by the outflow threshold and the reciprocal of the curve index of two outflow stages (B and D). A relative depression storage-outflow function (RDOF) was generated and a complete calculation procedure was applied within a hydrological model. Furthermore, we analyzed the hydrological responses to parameters of different hydrological factors to improve our understanding of the parameter determination of the RDOF.

4.
Anim Biotechnol ; 30(3): 202-211, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30595081

RESUMO

The objective of this study was to examine the association of transient receptor potential vanilloid 1 (TRPV1) and transient receptor potential ankyrin 1 (TRPA1) genes polymorphisms with growth traits in three Chinese cattle breeds (Jiaxian red cattle, Qinchuan cattle and Luxi cattle). Through experiments we identified three single nucleotide polymorphisms (SNPs) in these three cattle breeds TRPV1 and TRPA1 genes using PCR-SSCP, (forced) PCR-RFLP methods. Three of these polymorphisms are all synonymous mutation which includes (NW_003104493.1: 30327 C > T), (NW_003104493.1: 33394 A > G) and (NW_003104493.1: 38471 G > A) are in exons. The other three polymorphisms are located at 3'UTR. Furthermore, we evaluated the haplotype frequency and the statistical analyses indicated that these SNPs of TRPV1 and TRPA1 genes were associated with bovine body height, body length, waist angle width, hucklebone width, cross ministry height, chest qingwidth (p < 0.05) and recommendation height, cannon circumference (p < 0.01) of Qingchuan cattle; body length, waist angle width (p < 0.05) of Jiaxian red cattle; body weight, Body length, cannon circumference, chest circumference (p < 0.05) and body height (p < 0.01) of Luxi cattle. Our result confirms the polymorphisms in the TRPV1 and TRPA1 genes are associated with growth traits that may be used for marker-assisted selection (MAS) in three beef breeds programs.


Assuntos
Bovinos/genética , Variação Genética , Canal de Cátion TRPA1/genética , Canais de Cátion TRPV/genética , Animais , Tamanho Corporal/genética , Peso Corporal/genética , Cruzamento , Éxons/genética , Feminino , Haplótipos , Fenótipo , Polimorfismo de Nucleotídeo Único , Característica Quantitativa Herdável
5.
J Oncol Pract ; 13(1): e77-e90, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27845868

RESUMO

PURPOSE: Breast cancer offers several opportunities for reducing use of ineffective practices based on American Society of Clinical Oncology guidelines. We assessed oncologist-perceived factors associated with use of one such practice-serum tumor markers for post-treatment breast cancer surveillance-focusing on medical oncologists with high, medium, or low test use. METHODS: Using a mixed-methods design, we identified patients who had been treated for early-stage breast cancer diagnosed between January 1, 2009, and December 31, 2012, within Kaiser Permanente Southern California and calculated the number of tests ordered from January 1, 2010, to December 31, 2014. We identified oncologists with high, medium, or low use and subsequently performed semistructured interviews. We used patient satisfaction data to assess association between pattern of use and satisfaction score. RESULTS: We identified 7,363 patients, with 40,114 tests ordered. High-use oncologists were defined as those ordering at least one test annually for 35% of patients or more, low-use oncologists as those ordering at least one test for 5% of patients or less; 42% of oncologists were high, 27% low, and 31% medium users. We interviewed 17 oncologists: six high, eight low, and three medium users. Factors associated with high use included: perceived patient anxiety, oncologist anxiety, belief that there was nothing else to offer, concern about satisfaction, patient competition, peer use, and system barriers. Factors associated with low use included: beliefs about consequences (eg, causes harms) and medical center culture (eg, collective decision to follow guidelines). We found no association between satisfaction score and pattern of use. CONCLUSION: Barriers to deimplementation are numerous and complex. Traditional strategies of practice change alone are unlikely to be effective. Multifaceted, multilevel strategies deployed to address patient-, clinician-, and system-related barriers may be required.


Assuntos
Biomarcadores Tumorais/sangue , Neoplasias da Mama/diagnóstico , Ansiedade , Neoplasias da Mama/psicologia , Neoplasias da Mama/terapia , Estudos de Coortes , Cultura , Feminino , Humanos , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Oncologistas , Vigilância da População
6.
Phys Rev E ; 93(3): 032144, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27078329

RESUMO

Non-Gaussian normal diffusion, i.e., the probability density function (PDF) is non-Gaussian but the mean squared displacement (MSD) depends on time linearly, has been observed in particle motions. Here we show by numerical simulations that this phenomenon may manifest itself in energy diffusion along a lattice at a nonzero, finite temperature. The studied model is a one-dimensional disordered lattice with on-site potential. We find that the energy density fluctuations are spatially localized if the nonlinear interaction is suppressed, but may spread with a non-Gaussian PDF and a linear time-dependent MSD when the nonlinear interaction is turned on. Our analysis suggests that the mechanism lies in the delocalization properties of the localized modes.

7.
Artigo em Inglês | MEDLINE | ID: mdl-26465457

RESUMO

We study effects of interaction symmetry in one-dimensional, momentum-conserving disordered lattices. It is found that asymmetric and symmetric interparticle interactions may result in significant difference: localized modes can be delocalized by very weak asymmetric interactions but survive much stronger symmetric interactions. Moreover, in the delocalization regime, asymmetric and symmetric interactions also have qualitatively different effects on transport: the former (the latter) may lead to a fast decaying (slow power-law decaying) heat current correlation function and in turn a convergent (divergent) heat conductivity. A method for detecting delocalization in systems at a nonzero temperature is proposed as well.

8.
J Hazard Mater ; 298: 221-31, 2015 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-26057584

RESUMO

In 2002, U.S. EPA proposed a general buffer zone of approximately 100 feet (30 m) laterally to determine which buildings to include in vapor intrusion (VI) investigations. However, this screening distance can be threatened by factors such as extensive surface pavements. Under such circumstances, EPA recommended investigating soil vapor migration distance on a site-specific basis. To serve this purpose, we present an analytical model (AAMLPH) as an alternative to estimate lateral VI screening distances at chlorinated compound-contaminated sites. Based on a previously introduced model (AAML), AAMLPH is developed by considering the effects of impervious surface cover and soil geology heterogeneities, providing predictions consistent with the three-dimensional (3-D) numerical simulated results. By employing risk-based and contribution-based screening levels of subslab concentrations (50 and 500 µg/m(3), respectively) and source-to-subslab attenuation factor (0.001 and 0.01, respectively), AAMLPH suggests that buildings greater than 30 m from a plume boundary can still be affected by VI in the presence of any two of the three factors, which are high source vapor concentration, shallow source and significant surface cover. This finding justifies the concern that EPA has expressed about the application of the 30 m lateral separation distance in the presence of physical barriers (e.g., asphalt covers or ice) at the ground surface.


Assuntos
Poluição do Ar em Ambientes Fechados/prevenção & controle , Algoritmos , Simulação por Computador , Previsões , Modelos Teóricos , Medição de Risco , Solo/química , Poluentes do Solo/análise , Estados Unidos , United States Environmental Protection Agency , Volatilização
9.
PLoS One ; 9(5): e96857, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24818606

RESUMO

Goat is an important agricultural animal for meat production. Functional studies have demonstrated that microRNAs (miRNAs) regulate gene expression at the post-transcriptional level and play an important role in various biological processes. Although studies on miRNAs expression profiles have been performed in various animals, relatively limited information about goat muscle miRNAs has been reported. To investigate the miRNAs involved in regulating different periods of skeletal muscle development, we herein performed a comprehensive research for expression profiles of caprine miRNAs during two developmental stages of skeletal muscles: fetal stage and six month-old stage. As a result, 15,627,457 and 15,593,721 clean reads were obtained from the fetal goat library (FC) and the six month old goat library (SMC), respectively. 464 known miRNAs and 83 novel miRNA candidates were identified. Furthermore, by comparing the miRNA profile, 336 differentially expressed miRNAs were identified and then the potential targets of the differentially expressed miRNAs were predicted. To understand the regulatory network of miRNAs during muscle development, the mRNA expression profiles for the two development stages were characterized and 7322 differentially expressed genes (DEGs) were identified. Then the potential targets of miRNAs were compared to the DEGs, the intersection of the two gene sets were screened out and called differentially expressed targets (DE-targets), which were involved in 231 pathways. Ten of the 231 pathways that have smallest P-value were shown as network figures. Based on the analysis of pathways and networks, we found that miR-424-5p and miR-29a might have important regulatory effect on muscle development, which needed to be further studied. This study provided the first global view of the miRNAs in caprine muscle tissues. Our results help elucidation of complex regulatory networks between miRNAs and mRNAs and for the study of muscle development.


Assuntos
MicroRNAs/genética , Músculo Esquelético/metabolismo , Animais , Perfilação da Expressão Gênica , Cabras
10.
Hypertension ; 54(6): 1284-90, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19822802

RESUMO

Adenosine-induced renovasodilation in Dahl rats is mediated via activation of adenosine(2A) receptors (A(2A)Rs) and stimulation of epoxyeicosatrienoic acid (EET) synthesis. Unlike Dahl salt-resistant rats, salt-sensitive rats exhibit an inability to upregulate the A(2A)R-EET pathway with salt loading; therefore, we examined the effect of in vivo inhibition of the A(2A)R-EET pathway on blood pressure and the natriuretic response to salt-loading in Dahl salt-resistant rats. N-Methylsulfonyl-6-(2-propargyloxyphenyl)hexanamide (MS-PPOH; 20 mg/kg per day), an epoxygenase inhibitor, or ZM241385 (ZM; 5 mg/kg per day), an A(2A)R antagonist, was given daily as an IV bolus dose for 3 days before and after placing rats on high salt intake (2% saline). After 3 days of high salt, systolic blood pressure per 24 hours increased from 108+/-2 mm Hg to 136+/-5 mm Hg and 140+/-4 mm Hg when treated with MS-PPOH or ZM, respectively (P<0.001). Plasma levels of EETs and dihydroxyeicosatrienoic acids during salt loading and MS-PPOH (29.3+/-1.8 ng/mL) or ZM treatment (9.8+/-0.5 ng/mL) did not increase to the same extent as in vehicle-treated rats (59.4+/-1.7 ng/mL; P<0.001), and renal levels of EETs+dihydroxyeicosatrienoic acids were 2-fold lower with MS-PPOH or ZM treatment. On day 3 of the high salt intake, MS-PPOH- and ZM-treated rats exhibited a positive Na(+) balance, and plasma Na(+) levels were significantly increased (163.3+/-1.2 and 158.1+/-4.5 mEq/L, respectively) compared with vehicle-treated rats (142.1+/-1 mEq/L), reflecting a diminished natriuretic capacity. These data support a role for the A(2A)R-EET pathway in the adaptive natriuretic response to modulate blood pressure during salt loading.


Assuntos
Antagonistas de Receptores Adrenérgicos alfa 2 , Amidas/farmacologia , Eicosanoides/metabolismo , Hipertensão Renal/metabolismo , Receptores Adrenérgicos alfa 2/metabolismo , Animais , Pressão Sanguínea/efeitos dos fármacos , Pressão Sanguínea/fisiologia , Ingestão de Líquidos/fisiologia , Eicosanoides/antagonistas & inibidores , Ácidos Hidroxieicosatetraenoicos/sangue , Hipertensão Renal/induzido quimicamente , Masculino , Natriurese/efeitos dos fármacos , Natriurese/fisiologia , Oxirredutases/antagonistas & inibidores , Oxirredutases/metabolismo , Ratos , Ratos Endogâmicos Dahl , Cloreto de Sódio na Dieta/farmacologia , Triazinas/farmacologia , Triazóis/farmacologia
11.
Cancer Lett ; 200(1): 57-67, 2003 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-14550953

RESUMO

The extracellular matrix protein 1 (ECM1) is a secreted protein that has been implicated with cell proliferation, angiogenesis and differentiation. In the present study, we used immunohistochemical staining to examine the expression of ECM1 in a panel of human tumors and found that it was closely correlated with some types of tumors including: invasive breast ductal carcinoma (83%), esophageal squamous carcinoma (73%), gastric cancer (88%) and colorectal cancer (78%). Significantly, ECM1expression was correlated with the metastatic properties of the tumors. Primary breast cancers that had formed metastases were 76% positive while those that had not metastasized were only 33% positive. ECM1 expression was also correlated with PCNA a marker for proliferation, but not with CD34, a marker for endothelial cells. These results indicate that ECM1 tends to be preferentially expressed by metastatic epithelial tumors.


Assuntos
Carcinoma/metabolismo , Proteínas da Matriz Extracelular/metabolismo , Neoplasias/metabolismo , Antígenos CD34/metabolismo , Biomarcadores Tumorais , Neoplasias da Mama/metabolismo , Divisão Celular , Proteínas da Matriz Extracelular/imunologia , Humanos , Imuno-Histoquímica , Metástase Neoplásica , Neovascularização Patológica , Antígeno Nuclear de Célula em Proliferação/metabolismo
12.
Space Med Med Eng (Beijing) ; 16(5): 379-81, 2003 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-14753242

RESUMO

OBJECTIVE: To study the effects of tail-suspension on gonad and spermatic hormone in male rats. METHOD: After tail-suspension and reambulation some times in male rats, weight of testis was measured, sperm of epididymis was inspected, morphology of testicular cell was compared, and antent of testosterone assay by radioimmunoassay ratio of LH-beta positive cell in pituitary was measured by immunohistochemic. RESULT: After tail-suspension, weight of testis in male rats decreased significantly. Shape of the convoluted tubules and number of all levels of the spermatocyte in testis atrophied markedly. No sperm was found in the epididymis. Content of testosterone decreased markedly. Number of positive cell of beta-subunit of LH in the pituitary increased markedly. CONCLUSION: Tail-suspension has negative effect on sex gland and reproduction function of male rats.


Assuntos
Reprodução/fisiologia , Testículo/metabolismo , Testículo/patologia , Testosterona/metabolismo , Simulação de Ausência de Peso , Animais , Atrofia , Elevação dos Membros Posteriores , Hormônio Luteinizante/metabolismo , Masculino , Tamanho do Órgão , Hipófise/citologia , Hipófise/metabolismo , Ratos , Ratos Wistar , Espermatozoides/fisiologia , Testículo/citologia
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