2,458 research outputs found
Self-Trapping of Bose-Einstein Condensates in an Optical Lattice: the Effect of the System Dimension
In the present paper, we investigate the dynamics of a Bose-Einstein
condensates (BEC) loaded into an deep optical lattice of 1D, 2D and 3D, both
analytically and numerically. We focus on the self-trapping state and the
effect of the system dimension. Under the tight-binding approximation we obtain
an analytical criterion for the self-trapping state of BEC using time-dependent
variational method. The phase diagram for self-trapping, soliton, breather, or
diffusion of the BEC cloud is obtained accordingly and verified by directly
solving the discrete Gross-Pitaevskii equation (GPE) numerically. In
particular, we find that the criterion and the phase diagrams are modified
dramatically by the dimension of the lattices.Comment: 8pages, 9 figure
Noise in Genotype Selection Model
We study the steady state properties of a genotype selection model in
presence of correlated Gaussian white noise. The effect of the noise on the
genotype selection model is discussed. It is found that correlated noise can
break the balance of gene selection and induce the phase transition which can
makes us select one type gene haploid from a gene group.Comment: 8 pages, 4 figure
Analysis of the EGFR gene mutation in patients with nonsmall cell lung cancer in a Chinese population
Purpose: To investigate the epidermal growth factor receptor (EGFR) gene mutations and analyze their clinical significance in patients with non-small cell lung cancer (NSCLC) in Hubei province of China.Methods: A total of 138 paraffin embedded tissues were taken from patients with NSCLC who were treated at Hubei Hospital from January 2014 to June 2015. The tissue DNA was extracted and EGFR mutation was evaluated by polymerase chain reaction (PCR) sequencing analysis of exons 18, 19, 20, and 21.Results: The overall mutation rate of EGFR gene was 30.43 % (42/138) in 138 NSCLC patients. The mutation rates of EGFR gene at exon 18, 19, 20, 21 were 0 %(0/138), 13.8 %(19/138), 0.7 % (1/138) and 15.9 % (22/138), respectively. The mutation rate of EGFR gene was higher in female patients than that in males (62.2 % (28/45) vs 15.1 % (14/93), p < 0.01), and higher in non-smoking patients than in smoking ones (p < 0.05), but had no correlation with age in NSCLC patients (p > 0.05). EGFR mutation frequency in adenocarcinoma was higher than that in squamous cell carcinoma: 33.9 % (41/121) vs. 5.9 % (1/17, p < 0.05).Conclusion: EGFR mutations in NSCLC patients mainly exist in exons 19 and 21, and the mutation rate of exon 21 is higher than that of exon 19, which is more commonly found in female, adenocarcinoma and non-smoking patients.Keywords: Non-small cell lung cancer, Epidermal growth factor receptor (EGFR), Targeted therapy, Sequencin
Current Reversals in a inhomogeneous system with asymmetric unbiased fluctuations
We present a study of transport of a Brownian particle moving in periodic
symmetric potential in the presence of asymmetric unbiased fluctuations. The
particle is considered to move in a medium with periodic space dependent
friction. By tuning the parameters of the system, the direction of current
exhibit reversals, both as a function of temperature as well as the amplitude
of rocking force. We found that the mutual interplay between the opposite
driving factors is the necessary term for current reversals.Comment: 9 pages, 7 figure
Efficiency optimization in a correlation ratchet with asymmetric unbiased fluctuations
The efficiency of a Brownian particle moving in periodic potential in the
presence of asymmetric unbiased fluctuations is investigated. We found that
there is a regime where the efficiency can be a peaked function of temperature,
which proves that thermal fluctuations facilitate the efficiency of energy
transformation, contradicting the earlier findings (H. kamegawa et al. Phys.
Rev. Lett. 80 (1998) 5251). It is also found that the mutual interplay between
asymmetry of fluctuation and asymmetry of the potential may induce optimized
efficiency at finite temperature. The ratchet is not most efficiency when it
gives maximum current.Comment: 10 pages, 7 figure
A Microscopic Mechanism for Muscle's Motion
The SIRM (Stochastic Inclined Rods Model) proposed by H. Matsuura and M.
Nakano can explain the muscle's motion perfectly, but the intermolecular
potential between myosin head and G-actin is too simple and only repulsive
potential is considered. In this paper we study the SIRM with different complex
potential and discuss the effect of the spring on the system. The calculation
results show that the spring, the effective radius of the G-actin and the
intermolecular potential play key roles in the motion. The sliding speed is
about calculated from the model which well agrees with
the experimental data.Comment: 9 pages, 6 figure
Buyang Huanwu Decoction for Healthcare: Evidence-Based Theoretical Interpretations of Treating Different Diseases with the Same Method and Target of Vascularity
Buyang Huanwu Decoction (BHD) is a famous herbal prescription that has been used to treat stroke for centuries. Recent studies reported that the use of BHD had been extended to treat various kinds of disorders according to the TCM syndrome theory of Treating Different Diseases with the Same Method (TDDSM). Here, an overview of systematic reviews (SRs) of BHD for healthcare was conducted to interpret the TCM theory of TDDSM and its target of vascularity in an evidence-based manner. Literature searches were carried out in 5 databases to search SRs of BHD for any indication up to August 2013. Thirteen eligible SRs were identified which reported a wide range of vascular conditions. Based on the Overview Quality Assessment Questionnaire scores, the quality of included SRs was varied, with an average score of 4 points. We found that there is premature evidence for the use of BHD for healthcare, whereas BHD was well tolerable in all patients. BHD can be used to treat many disorders with the same therapeutic principle of invigorating Qi to activate blood circulation, which is essentially a manifestation of the TDDSM and is likely to account for targeting the specific pathogenesis of vascular diseases
Correlated noise in a logistic growth model
The logistic differential equation is used to analyze cancer cell population,
in the presence of a correlated Gaussian white noise. We study the steady state
properties of tumor cell growth and discuss the effects of the correlated
noise. It is found that the degree of correlation of the noise can cause tumor
cell extinction.Comment: 3 pages, 4 figure
mDIXON-Quant for differentiation of renal damage degree in patients with chronic kidney disease
BackgroundChronic kidney disease (CKD) is a complex syndrome with high morbidity and slow progression. Early stages of CKD are asymptomatic and lack of awareness at this stage allows CKD to progress through to advanced stages. Early detection of CKD is critical for the early intervention and prognosis improvement.PurposeTo assess the capability of mDIXON-Quant imaging to detect early CKD and evaluate the degree of renal damage in patients with CKD.Study typeRetrospective.Population35 patients with CKD: 18 cases were classifified as the mild renal damage group (group A) and 17 cases were classifified as the moderate to severe renal damage group (group B). 22 healthy volunteers (group C).Field strength/sequenceA 3.0 T/T1WI, T2WI and mDIXON-Quant sequences.AssessmentTransverse relaxation rate (R2*) values and fat fraction (FF) values derived from the mDIXON-Quant were calculated and compared among the three groups.Statistical testsThe intra-class correlation (ICC) test; Chi-square test or Fisher’s exact test; Shapiro-Wilk test; Kruskal Wallis test with adjustments for multiplicity (Bonferroni test); Area under the receiver operating characteristic (ROC) curve (AUC). The significance threshold was set at P < 0.05.ResultsCortex FF values and cortex R2* values were significantly different among the three groups (P=0.028, <0.001), while medulla R2* values and medulla FF values were not (P=0.110, 0.139). Cortex FF values of group B was significantly higher than that of group A (Bonferroni adjusted P = 0.027). Cortex R2* values of group A and group B were both significantly higher than that of group C (Bonferroni adjusted P = 0.012, 0.001). The AUC of cortex FF values in distinguishing group A and group B was 0.766. The diagnostic efficiency of cortex R2* values in distinguishing group A vs. group C and group B vs. group C were 0.788 and 0.829.ConclusionThe mDIXON-Quant imaging had a potential clinical value in early diagnosis of CKD and assessing the degree of renal damage in CKD patients
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