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1.
Arch Microbiol ; 203(10): 6267-6274, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34581832

ABSTRACT

In this study, we screened bacterial strains to identify specific probiotics to treat pig diarrhea caused by Escherichia coli or Salmonella. The potential probiotics were assayed for their survival in gastrointestinal solution, their antimicrobial activity, cell-surface properties, adhesion to Caco-2 cells, and inhibition of pathogen adhesion. Nine out of the 20 strains tested showed high tolerance of a simulated gastrointestinal environment and six strains exerted antagonistic effects against enterohemorrhagic E. coli (EHEC) O157:H7 and Salmonella Typhimurium MQ. Lactobacillus johnsonii pDX1e exhibited a higher potent antibacterial activity. Four strains (pDX1a, pDX1e, pDX3a, and pDX5a) displayed auto-aggregation, hydrophobicity, and adhesion to Caco-2 cells similar to those of the reference strain Lacticaseibacillus rhamnosus GG (LGG). Enterococcus durans pDX5a showed the highest adhesion capacity (13.86%), followed by the reference strain LGG (11.20%). All the tested strains competitively suppressed the attachment of pathogens to Caco-2 cells (by 30.73-55.18%); L. johnsonii pDX1e and Ent. durans pDX5a significantly inhibited the adhesion of pathogens by substitution and exclusion, respectively. Therefore, pDX1e and pDX5a were selected as probiotic strains for further investigation and application.


Subject(s)
Escherichia coli O157 , Probiotics , Animals , Bacterial Adhesion , Caco-2 Cells , Enterococcus , Humans , Lactobacillus , Salmonella typhimurium , Swine
2.
Korean J Parasitol ; 53(3): 361-4, 2015 Jun.
Article in English | MEDLINE | ID: mdl-26174833

ABSTRACT

Gynandromorphic ticks are extremely rare, and often attract parasitologists' attention. During our examination of tick specimens, an engorged gynandromorph of Hyalomma asiaticum was noticed. This is the first record of gynandromorphic ticks from China. In this study, several important morphological structures of normal and gynandromorphic H. asiaticum were analyzed. Comparing to the normal H. asiaticum, the gynandromorphic specimen was a typical bipartite protogynander. Its right side showed normal female characteristics, whereas the left side had normal male traits. Different from other gynandromorphic ticks containing 1 anus, this tick reported here had 2 complete anuses, and the anus of the male part had a single adanal plate.


Subject(s)
Chimera/anatomy & histology , Ixodidae/anatomy & histology , Sheep Diseases/parasitology , Tick Infestations/veterinary , Animals , Chimera/genetics , China , Female , Ixodidae/genetics , Male , Sheep , Tick Infestations/parasitology
3.
Front Oncol ; 14: 1386597, 2024.
Article in English | MEDLINE | ID: mdl-38947889

ABSTRACT

Treatment intensification with androgen deprivation therapy (ADT) and androgen receptor pathway inhibitors (ARPi) have led to improved survival in advanced prostate cancer. However, ADT is linked to significant cardiovascular toxicity, and ARPi also negatively impacts cardiovascular health. Together with a higher prevalence of baseline cardiovascular risk factors reported among prostate cancer survivors at diagnosis, there is a pressing need to prioritise and optimise cardiovascular health in this population. Firstly, While no dedicated cardiovascular toxicity risk calculators are available, other tools such as SCORE2 can be used for baseline cardiovascular risk assessment. Next, selected patients on combination therapy may benefit from de-escalation of ADT to minimise its toxicities while maintaining cancer control. These patients can be characterised by an exceptional PSA response to hormonal treatment, favourable disease characteristics and competing comorbidities that warrant a less aggressive treatment regime. In addition, emerging molecular and genomic biomarkers hold the potential to identify patients who are suited for a de-escalated treatment approach either with ADT or with ARPi. One such biomarker is AR-V7 splice variant that predicts resistance to ARPi. Lastly, optimization of modifiable cardiovascular risk factors for patients through a coherent framework (ABCDE) and exercise therapy is equally important. This article aims to comprehensively review the cardiovascular impact of hormonal manipulation in metastatic hormone-sensitive prostate cancer, propose overarching strategies to mitigate cardiovascular toxicity associated with hormonal treatment, and, most importantly, raise awareness about the detrimental cardiovascular effects inherent in our current management strategies involving hormonal agents.

4.
J Phys Condens Matter ; 35(15)2023 Feb 21.
Article in English | MEDLINE | ID: mdl-36731170

ABSTRACT

The Ginzburg-Landau theory, which was introduced to phenomenologically describe the destruction of superconductivity by a magnetic field at the beginning, has brought up much more knowledge beyond the original one as a mean-field theory of thermodynamics states. There the complex order parameter plays an important role. Here we propose a macroscopic theory to describe the features of ferroelectrics by a two-component complex order parameter coupled to nonabelian gauge potentials that provide more freedom to reflect interplays between different measurables. Within this theoretical framework, some recently discovered empirical static and time-independent phenomena, such as vortex, anti-vortex, spiral orders can be obtained as solutions for different gauge potentials. It is expected to bring in a new angle of view with more elucidation than the traditional one that takes the polarization as order parameter.

5.
Asia Pac J Clin Oncol ; 18(5): e346-e355, 2022 Oct.
Article in English | MEDLINE | ID: mdl-34908240

ABSTRACT

AIMS: Ultra-hypofractionated radiotherapy (UHF-RT) is widely utilized in men with localized prostate cancer (PCa). There are limited data in Asian cohorts. We report the outcomes of a single-arm, phase II trial of UHF-RT from an Asian center. METHODS: We recruited men with histologically confirmed, nonmetastatic localized PCa. UHF-RT regimens were 36.25 Gy (Cohort A) and 37.5 Gy (Cohort B) delivered in five fractions every other day over 1.5-2.5 weeks. Primary endpoint was physician-scored late genitourinary (GU) and gastrointestinal (GI) adverse events (AEs). Quality-of-life (QoL) was assessed by Expanded Prostate Cancer Index Composite (EPIC) at baseline, 1- and 2-year post-UHF-RT. RESULTS: Between March 2014 and August 2019, 105 men were recruited; four were subsequently excluded from analysis. Median age was 68.0 (Interquartile range (IQR): 63.8-73.0) years. 26 (24.8%) and 68 (64.8%) men had NCCN-defined low-and intermediate-risk PCa, respectively. No late ≥G3 GU or GI toxicities were reported in both cohorts. Peak incidence of acute ≥G2 GU AEs at 14 days post-UHF-RT was 23.6% (17/72) and 24.0% (6/25) in Cohorts A and B, respectively; ≥G2 GI AEs were observed in 9.7% (7/72) and 36.0% (9/25), respectively. Late ≥G2 GU and GI AEs occurred in 4.7% and 3.1% of Cohort A patients, and 5.0% in Cohort B at 12 months, with no AEs at 24 months. EPIC scores changed minimally across all domains. At a median follow-up of 44.9 months, we recorded one (1.3%) biochemical relapse by the Phoenix criteria (Cohort A). CONCLUSION: UHF-RT is well tolerated in Asian men and can be a recommended fractionation schema for localized PCa.


Subject(s)
Gastrointestinal Diseases , Prostatic Neoplasms , Radiotherapy, Intensity-Modulated , Aged , Dose Fractionation, Radiation , Gastrointestinal Diseases/etiology , Humans , Male , Middle Aged , Prostatic Neoplasms/pathology , Prostatic Neoplasms/radiotherapy , Quality of Life , Radiation Dose Hypofractionation , Radiotherapy, Intensity-Modulated/adverse effects
6.
J Phys Condens Matter ; 23(6): 066002, 2011 Feb 16.
Article in English | MEDLINE | ID: mdl-21406937

ABSTRACT

In this paper, we study conically spiral multiferroic magnets with coupled magnetic and ferroelectric orders. By generalizing the spin-current model, we study spin wave excitations and electromagnons. We find that the electromagnon mode will split into two branches with different dispersions in an (external or internal) magnetic field. We apply our theory to some multiferroic materials and find that the results qualitatively agree with recent experiments. We also make predictions for new experiments.

7.
Chin J Cancer Res ; 23(2): 129-33, 2011 Jun.
Article in English | MEDLINE | ID: mdl-23482452

ABSTRACT

OBJECTIVE: To evaluate the maximum tolerated dose (MTD) of docetaxel (DCT) and cisplatin (DDP) concurrently with three dimensional (3D) conformal radiotherapy or IMRT for patients with locally advanced non-small cell lung cancer (stage IIIa and IIIb) after 2-4 cycles of induction chemotherapy. METHODS: Fourteen patients with histological/cytological proven stage III non-small-cell lung cancer were eligible. 3D or IMRT radiotherapy (60-70Gy in 30-35 fractions, 6-7weeks, 2 Gy/fraction) was delivered concurrently with cisplatin and docetaxel, 2 cycles during concurrent chemoradiotherapy (CCRT). The level I dosage was composed of 56 mg/m(2) DCT, on day 1 and 28mg/m(2) DDP, on day 1 and day 2. The level II was composed of 60 mg/m(2) DCT, on day 1 and 30 mg/ m(2) DDP, on day 1 and day 2. The level III was composed of 64 mg/m(2) DCT, on day 1 and 32 mg/ m(2) DDP, on day 1 and day 2. RESULTS: Fourteen patients were allocated and finished concurrent chemoradiotherapy. The dose-limiting neutropenia was at the dose Level III (64 mg/m(2)) and occurred in 2 of 5 patients. No dose limiting non-hematologic or hematologic toxicity occurred in the other patients. CONCLUSIONS: Patients with locally advanced non-small cell lung cancer may tolerate 60mg/m(2) docetaxel and 60mg/m(2) cisplatin for 2 cycles during concurrent radiotherapy after 2-3 cycles of induction chemotherapy.

8.
Eur Phys J E Soft Matter ; 32(1): 103-7, 2010 May.
Article in English | MEDLINE | ID: mdl-20524028

ABSTRACT

The presence of highly regular secondary structure motifs in protein structure is a fascinating area of study. The secondary structures play important roles in protein structure and protein folding. We investigate the folding properties of protein by introducing the effect of secondary structure elements. We observed the emergence of several structures with both large average energy gap and high designability. The dynamic study indicates that these structures are more foldable than those without the effect of secondary structures.


Subject(s)
Protein Folding , Proteins/chemistry , Models, Molecular , Protein Structure, Secondary , Temperature , Thermodynamics
9.
Article in English | MEDLINE | ID: mdl-20806505

ABSTRACT

OBJECTIVE: To study the TaSP polymorphism in three Chinese isolates of Theileria annulata. METHODS: The isolates from Inner Mongolia Autonomous Region, Ningxia Hui Autonomous Region and Xinjiang Uygur Autonomous Region were cultured in RPMI 1640 medium. TaSP gene was amplified from genomic DNA extracted from schizonts using polymerase chain reaction (PCR) and sequenced. Its amino acid sequence comparison was carried out with Clustal W2 multiple sequence alignment program. Molecular component and motif prediction were performed with online servers. RESULTS: The comparison of TaSP amino acid sequences of the three isolates showed that the central region (aa position 38-161) predicted to be the highly immunogenetic domain was polymorphic both in size and amino acid sequence, while the N-terminal (first 37 aa) and C-terminal (last 154 aa) parts were strongly conserved. Phylogenetic analysis and percentage identity revealed that the Chinese isolates were closely related to the isolates from Turkey, but quite different from those of India, Morocco and Tunisia. More importantly, variability was noticed among Chinese isolates, which caused both the location and number's differences of motif (casein kinase II phosphorylation sites) among three TaSP sequences. CONCLUSION: TaSP polymorphism exists in the Chinese isolates of T. annulata.


Subject(s)
Membrane Proteins/genetics , Protozoan Proteins/genetics , Theileria annulata/genetics , Amino Acid Sequence , Animals , Cell Line , Molecular Sequence Data , Polymorphism, Genetic , Sequence Alignment , Sequence Analysis , Theileria annulata/classification , Theileria annulata/isolation & purification
10.
J Chem Phys ; 130(12): 124510, 2009 Mar 28.
Article in English | MEDLINE | ID: mdl-19334854

ABSTRACT

Synchronization of a spiral by a circularly polarized electric field (CPEF) in reaction-diffusion systems is investigated since they both possess rotation symmetry. It is found that spirals in different regimes (including rigidly rotating, meandering, and drifting spirals) can be forced to be rigidly rotating ones by CPEFs. Moreover, the rotational frequency of the entrained spiral is found to be synchronized with the frequency of the electric field in a ratio of 1:1.


Subject(s)
Diffusion , Electricity , Models, Chemical , Rotation
11.
Phys Rev E Stat Nonlin Soft Matter Phys ; 79(3 Pt 2): 036107, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19392018

ABSTRACT

The influence of circularly polarized electric fields (CPEFs) on the stability of multiarmed spiral waves is investigated. It is shown that CPEFs can change the period of the multiarmed spirals. The average period is an important quantity of multiarmed spiral and it must be larger than a threshold for stable multiarmed spiral. After a counter-rotating CPEF with suitable amplitude and period is applied, the average period of the multiarmed spiral may increase, which stabilizes the multiarmed spiral.

12.
J Phys Condens Matter ; 21(5): 055601, 2009 Feb 04.
Article in English | MEDLINE | ID: mdl-21817305

ABSTRACT

The coherent tunnelling spin current in the bilayer system with spin-orbit coupling is investigated. Based on the continuity-like equations, we discuss the definition of the tunnelling current and show that the overlaps between wavefunctions for different layers contribute to the tunnelling current. We study the linear response of the tunnelling spin current to an in-plane electric field in the presence of nonmagnetic impurities. The tunnelling spin conductivity we obtained presents a feature asymmetrical with respect to the gate voltage when the strengths of impurity potentials are different in each layer.

13.
Article in Zh | MEDLINE | ID: mdl-19856516

ABSTRACT

Two splenectomized sheep were infected respectively with Theileria luwenshuni and T. uilenbergi, 2 species identified by PCR. When piroplasms were found in blood smears from ears of the sheep, morphological observation on the Theileria spp. was carried out by optical microscopy. By Giemsa staining, the cytoplasm exhibited in slight blue and nucleus in purple. The two Theileria species displayed various shapes, but pyriform-shaped, round-shaped and needle-shaped parasites appeared in every stage of the infection. In fact, there is no significant morphological difference between the two species.


Subject(s)
Sheep Diseases/parasitology , Theileria/classification , Theileria/ultrastructure , Theileriasis/parasitology , Animals , Sheep , Theileria/isolation & purification
14.
Article in Zh | MEDLINE | ID: mdl-20232640

ABSTRACT

A pair of specific primers was designed based on the reported Bm86 gene of Boophilus microplus,the Bm86 gene was cloned by PCR using the plasmid pMD18-T-Bm86 as templates, and subcloned into the prokaryotic plasmid pGEX-4T-1. The recombined plasmid was transformed into E. coli BL21(DE3) and followed by expression of the protein induced by different concentration of IPTG for different time. SDS-PAGE showed that the recombinant plasmid pGEX-4T-1/Bm86 expressed a fusion protein Bm86-GST (Mr 94 000) after being induced with IPTG. High level expression of Bm86-GST was found at 1 mmol/L IPTG condition a fter incubation for 8 h at 37 degree C, and the expression level of the recombinant Bm86-GST reached up to 29% of total E coli proteins Western-blotting analysis showed that the recombinant Bm86-GST was recognized by the rabbit anti-B. microplus positive serum.


Subject(s)
Ixodidae/genetics , Membrane Glycoproteins/genetics , Recombinant Proteins/genetics , Vaccines/genetics , Animals , Blotting, Western , Cloning, Molecular , Gene Expression , Membrane Glycoproteins/immunology , Molecular Sequence Data , Plasmids , Recombinant Proteins/immunology , Recombinant Proteins/metabolism , Vaccines/immunology
15.
Ann Palliat Med ; 8(4): 390-400, 2019 Sep.
Article in English | MEDLINE | ID: mdl-30943738

ABSTRACT

BACKGROUND: Breast cancer (BC) patients with brain metastases (BM) are heterogeneous with markedly variable survival. The Breast Graded Prognostic Assessment (B-GPA) and Modified B-GPA (mB-GPA) have been proposed as useful tools for stratifying survival in this population. However, extra-cranial disease progression, a clinically important variable, is not incorporated into the final model. We undertook the validation of B-GPA and mB-GPA in an Asian cohort and further explore extra-cranial disease progression as a prognostic factor. METHODS: Data of BC patients with newly diagnosed BM between 2006 and 2017 was extracted retrospectively from a prospectively maintained institutional database. Patients were classified based on their B-GPA and mB-GPA scores. Univariate (UVA) and multivariate analysis (MVA) using the Cox proportional hazard model were performed to investigate the factors prognostic of overall survival (OS). The Kaplan-Meier method was used to estimate OS and log-rank test to compare survival between scores. The performances of B-GPA and mB-GPA were compared using Harrell's concordance index (C-index) and Akaike information criterion (AIC). RESULTS: In our cohort of 282 patients, the B-GPA and mB-GPA were validated as prognostic tools for OS, demonstrating excellent separation between survival curves (P <0.001). In MVA, we found all components of mB-GPA (age, performance status, number of BM, tumour subtype) to be independent predictors of survival. C-index was 0.64 and AIC was 2,483.39 for B-GPA. mB-GPA demonstrated marginally better discrimination with a C-index of 0.65 and AIC of 2,445.78. Extra-cranial progression was an independent predictor for survival in our population (P <0.001). CONCLUSIONS: The mB-GPA incorporates four simple clinical variables each of independent prognostic significance. Both B-GPA and mB-GPA demonstrate moderate discriminative capabilities for OS with mB-GPA performing marginally better. Inclusion of extra-cranial disease progression as a factor in future model development may further improve its prognostic value.


Subject(s)
Brain Neoplasms/secondary , Breast Neoplasms , Adult , Aged , Brain Neoplasms/mortality , Disease Progression , Female , Humans , Kaplan-Meier Estimate , Karnofsky Performance Status , Middle Aged , Prognosis , Risk Factors , Young Adult
16.
Sci Rep ; 8(1): 7117, 2018 May 08.
Article in English | MEDLINE | ID: mdl-29740079

ABSTRACT

The continuous-time quantum walk on a one-dimensional graph of odd number of sites with an on-site potential at the center is studied. We show that such a quantum-walk system can construct an X-gate of a single qubit as well as a control gate for two qubits, when the potential is much larger than the hopping strength. We investigate the decoherence effect and find that the coherence time can be enhanced by either increasing the number of sites on the graph or the ratio of the potential to the hopping strength, which is expected to motivate the design of the quantum gate with long coherence time. We also suggest several experimental proposals to realize such a system.

17.
Chin Clin Oncol ; 7(1): 10, 2018 Feb.
Article in English | MEDLINE | ID: mdl-29486569

ABSTRACT

Intracranial hemangiopericytomas (HPC) are chemotherapy- and radiotherapy (RT)-resistant. Here, we report on a novel stereotactic radiosurgery (SRS) technique-"Cor Occidere" (Latin), as a potential strategy of overcoming radioresistance of HPC. A 36-year old female presented to our clinic for consideration of a 3rd-course of RT for her recurrent cavernous sinus HPC, following previous cranial RT at 13 and 5 years prior, and a failed 9 months trial of bevacizumab/temozolomide. The tumor-adjacent brain stem and carotid artery risked substantial damage given the cumulative RT doses to these organs. We therefore designed an SRS plan targeting only the tumor core with 16 Gy single-fraction. Despite underdosing the tumor margin, we achieved stable disease over 25 months, contrasting her responses to systemic therapies. Achieving tumor control despite a suboptimal treatment that utilized high dose ablation of the tumor core suggests novel biological mechanisms to overcome radioresistance of HPC.


Subject(s)
Brain Neoplasms/radiotherapy , Brain Neoplasms/surgery , Hemangiopericytoma/radiotherapy , Hemangiopericytoma/surgery , Radiosurgery/methods , Adult , Brain Neoplasms/pathology , Female , Hemangiopericytoma/pathology , Humans
18.
Chin Clin Oncol ; 7(2): 15, 2018 Apr.
Article in English | MEDLINE | ID: mdl-29764160

ABSTRACT

Immunotherapy and radiation therapy (RT) have each demonstrated clinical success in the treatment of nasopharyngeal carcinoma (NPC) when utilized independently. Several characteristics of NPC make it particularly well suited for immunotherapeutic strategies, such as the association with viral infections like EBV and human papilloma virus (HPV), upregulation of PD-L1 expression, and the high number of tumor infiltrating lymphocytes. Immune checkpoint blockade is one such immunotherapeutic strategy that is gaining popularity rapidly. However, clinical benefit of immunotherapy using immune checkpoint inhibitors has been limited to only a small subset of patients with existing T cell responses. Additionally, they are frequently associated with dose-limiting immune-related toxicities. On the other hand, RT is a conventional strategy for NPC treatment, which has demonstrated high efficacy in local tumor control and has also been reported to exhibit immune modulatory effects. However, the abscopal effect of RT alone, i.e., the regression of distant metastases outside of the irradiation field, remains a rare phenomenon. Furthermore, RT treatment efficacy is also limited by radioresistance and radiation-related toxicities. Hence, the combination of RT and immunotherapy has the potential to improve treatment efficacy over either individual therapies alone. Here, we reviewed the clinical problem in locally advanced and recurrent/metastatic NPC, and discussed how combinatorial RT and immunotherapeutic strategies can be relevant to NPC treatment in each clinical scenario by examining the underlying mechanisms involved in the different strategies.


Subject(s)
Carcinoma/radiotherapy , Combined Modality Therapy/methods , Immunotherapy/methods , Nasopharyngeal Neoplasms/radiotherapy , Carcinoma/pathology , Humans , Nasopharyngeal Carcinoma , Nasopharyngeal Neoplasms/pathology
19.
J Clin Oncol ; 36(9): 891-899, 2018 03 20.
Article in English | MEDLINE | ID: mdl-29412781

ABSTRACT

Purpose To investigate for a prognostic index (PI) to personalize recommendations for salvage intensity-modulated radiotherapy (IMRT) in patients with locally recurrent nasopharyngeal carcinoma (lrNPC). Methods Patients with lrNPC from two academic institutions (Sun Yat-Sen University Cancer Center [SYSUCC-A; n = 251 (training cohort)] and National Cancer Centre Singapore [NCCS; n = 114] and SYSUCC-B [n = 193 (validation cohorts)]) underwent salvage treatment with IMRT from 2001 to 2015. Primary and secondary clinical end points were overall survival (OS) and grade 5 toxicity-free rate (G5-TFR), respectively. Covariate inclusion to the PIs was qualified by a multivariable two-sided P < .05. Discrimination and calibration of the PIs were assessed. Results The primary PI comprised covariates that were adversely associated with OS in the training cohort (gross tumor volumerecurrence hazard ratio [HR], 1.01/mL increase [ P < .001], agerecurrence HR, 1.02/year increase [ P = .008]; repeat IMRT equivalent dose in 2-Gy fractions [EQD2] ≥ 68 Gy HR, 1.42 [ P = .03]; prior radiotherapy-induced grade ≥ 3 toxicities HR, 1.90 [ P = .001]; recurrent tumor [rT]-category 3 to 4 HR, 1.96 [ P = .005]), in ascending order of weight. Discrimination of the PI for OS was comparable between training and both validation cohorts (Harrell's C = 0.71 [SYSUCC-A], 0.72 [NCCS], and 0.69 [SYSUCC-B]); discretization by using a fixed PI score cutoff of 252 determined from the training data set yielded low- and high-risk subgroups with disparate OS in the validation cohorts (NCCS HR, 3.09 [95% CI, 1.95 to 4.89]; SYSUCC-B HR, 3.80 [95% CI, 2.55 to 5.66]). Our five-factor PI predicted OS and G5-TFR (predicted v observed 36-month OS and G5-TFR, 22% v 15% and 38% v 44% for high-risk NCCS and 26% v 31% and 45% v 46% for high-risk SYSUCC-B). Conclusion We present a validated PI for robust clinical stratification of radioresistant NPC. Low-risk patients represent ideal candidates for curative repeat IMRT, whereas novel clinical trials are needed in the unfavorable high-risk subgroup.


Subject(s)
Models, Statistical , Nasopharyngeal Carcinoma/radiotherapy , Nasopharyngeal Neoplasms/radiotherapy , Adult , Clinical Trials, Phase II as Topic , Cohort Studies , Female , Humans , Male , Middle Aged , Precision Medicine , Prognosis , Proportional Hazards Models , Radiation Tolerance , Radiotherapy, Intensity-Modulated , Randomized Controlled Trials as Topic , Salvage Therapy/methods
20.
Phys Rev E Stat Nonlin Soft Matter Phys ; 71(6 Pt 1): 061202, 2005 Jun.
Article in English | MEDLINE | ID: mdl-16089726

ABSTRACT

We investigate the heat conduction in a quasi-one-dimensional gas model with various degrees of chaos. Our calculations indicate that the heat conductivity kappa is independent of system size when the chaos of the channel is strong enough. The different diffusion behaviors for the cases of chaotic and nonchaotic channels are also studied. The numerical results of divergent exponent alpha of heat conduction and diffusion exponent beta are consistent with the formula alpha = 2 - 2/beta. We explore the temperature profiles numerically and analytically, which show that the temperature jump is primarily attributed to superdiffusion for both nonchaotic and chaotic cases, and for the latter case of superdiffusion the finite size affects the value of beta remarkably.

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