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Objective. Non-primary radiation doses to normal tissues from proton therapy may be associated with an increased risk of secondary malignancies, particularly in long-term survivors. Thus, a systematic method to evaluate if the dose level of non-primary radiation meets the IEC standard requirements is needed. Approach. Different from the traditional photon radiation therapy system, proton therapy systems are composed of several subsystems in a thick bunker. These subsystems are all possible sources of non-primary radiation threatening the patient. As a case study, 7 sources in the P-Cure synchrotron-based proton therapy system are modeled in Monte Carlo (MC) code: tandem injector, injection, synchrotron ring, extraction, beam transport line, scanning nozzle and concrete reflection/scattering. To accurately evaluate the synchrotron beam loss and non-primary dose, a new model called the torus source model is developed. Its parametric equations define the position and direction of the off-orbit particle bombardment on the torus pipe shell in the Cartesian coordinate system. Non-primary doses are finally calculated by several FLUKA simulations. Main results. The ratios of summarized non-primary doses from different sources to the planned dose of 2 Gy are all much smaller than the IEC requirements in both the 15–50 cm and 50–200 cm regions. Thus, the P-Cure synchrotron-based proton therapy system is clean and patient-friendly, and there is no need an inner shielding concrete between the accelerator and patient. Significance. Non-primary radiation dose level is a very important indicator to evaluate the quality of a PT system. This manuscript provides a feasible MC procedure for synchrotron-based proton therapy with new beam loss model. Which could help people figure out precisely whether this level complies with the IEC standard before the system put into clinical treatment. What' more, the torus source model could be widely used for bending magnets in gantries and synchrotrons to evaluate non-primary doses or other radiation doses. [ABSTRACT FROM AUTHOR]

Rare information on photodisintegration reactions of nuclei with mass numbers A ≈ 160 at astrophysical conditions impedes our understanding of the origin of p-nuclei. Experimental determination of the key (p, γ) cross sections has been playing an important role in verifying nuclear reaction models and providing rates of relevant (γ, p) reactions in the γ process. In this paper we report the first cross-section measurements of 160Dy(p, γ)161Ho and 161Dy(p, n)161Ho in the beam energy range of 3.4–7.0 MeV, partially covering the Gamow window. Such determinations are possible by using two targets with various isotopic fractions. The cross-section data can put a strong constraint on the nuclear level densities and gamma strength functions for A ≈ 160 in the Hauser–Feshbach statistical model. Furthermore, we find the best parameters for TALYS that reproduce the available A ∼ 160 data, 160Dy(p, γ)161Ho and 162Er(p, γ)163Tm, and recommend the constrained 161Ho(γ, p)160Dy reaction rates over a wide temperature range for γ process network calculations. Although the determined 161Ho(γ, p) stellar reaction rates at the temperature of 1 to 2 GK can differ by up to one order of magnitude from the NON-SMOKER predictions, it has a minor effect on the yields of 160Dy and accordingly the p-nuclei, 156,158Dy. A sensitivity study confirms that the cross section of 160Dy(p, γ)161Ho is measured precisely enough to predict yields of p nuclei in the γ process. [ABSTRACT FROM AUTHOR]

Effective traffic planning can effectively alleviate traffic jam caused by reconstruction and expansion of expressway. Because of the restriction of topography, traffic planning for reconstruction and expansion of expressway in mountain areas is more difficult than that in plain areas. It is very important to study traffic planning for reconstruction and expansion of expressway in mountain areas to relieve the traffic pressure caused by reconstruction and expansion. Based on Zhanglong section of Xia-rong expressway reconstruction and expansion project, this paper systematically analyzes traffic planning during construction according to the characteristics of expressway in mountain areas and discusses design experience of transformation section, long downgrade section and tunnel widened at original location to ensure road capacity and traffic safety. [ABSTRACT FROM AUTHOR]

The effects of molecular fluctuations on chemical oscillations and chaos are investigated. The calculations are carried out using a reactive lattice-gas automaton which provides a mesoscopic description of the reactive dynamics. A specific chemical model, the Willamowski–Rössler reaction, is used to illustrate the effects. The applicability of mass-action rate laws and reaction-diffusion equations are considered and the character of the fluctuations in various dynamical regimes for both spatially-distributed and spatially-homogeneous systems are examined. The work provides information on the molecular origin of macroscopic, self-organized structures in far-from-equilibrium reacting systems. [ABSTRACT FROM AUTHOR]

The onset of chemical turbulence in the 2-D complex Ginzburg–Landau equation is studied for a class of finite-amplitude, inhomogeneous, random initial conditions. Numerical simulations on a coupled map lattice corresponding to this reaction–diffusion equation are carried out in order to characterize the nature of the turbulent state. The phase diagram giving the zone of chemical turbulence in the parameter space that specifies the initial condition is determined numerically and compared with an analytical estimate. [ABSTRACT FROM AUTHOR]

The rate processes corresponding to barrier crossing dynamics in a symmetric double-well potential driven by a white-noise source are investigated. The rate kernels in the generalized phenomenological rate law describing the reaction involve time evolution through a projected Fokker–Planck operator. The spectral properties of the projected Fokker–Planck operator are studied, and the rate kernels are expressed in terms of the eigenvalues and eigenfunctions of this operator. The formal results are illustrated with numerical calculations. The results provide information on the nature of the generalized chemical rate law for fast processes. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the diagnostic value of the cerebrospinal fluid (CSF) T-SPOT.TB test for the diagnosis of TB meningitis (TBM). A retrospective analysis of 96 patients with manifested meningitis was conducted; T-SPOT.TB test was performed for diagnosing TBM to determine the diagnostic sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). A receiver operating characteristic (ROC) curve was also drawn to assess the diagnostic accuracy. The sensitivity, specificity, PPV, and NPV of CSF T-SPOT.TB test were 97.8%, 78.0%, 80.3%, and 97.5%, respectively, for 52 patients (54.2%) of the 96 enrolled patients. The area under the curve (AUC) was 0.910, and the sensitivities of CSF T-SPOT.TB for patients with stages I, II, and III of TBM were 96.7%, 97.2%, and 98.9%, respectively. CSF T-SPOT.TB test is a rapid and accurate diagnostic method with higher sensitivity and specificity for diagnosing TBM. [ABSTRACT FROM AUTHOR]

Primary objective: To study the effect of flavonoids isolated from aerial parts ofScutellaria baicalensisGeorgi (SSF) on cerebral damage induced by okadaic acid (OA) in rats. Methods and procedures: OA was microinjected into the right lateral ventricle of male rats at a dose of 200 ng kg−1twice with a 3-day interval between injections to establish a model of Alzheimer’s-disease-like cerebral damage. Neuronal morphology was observed with thionin staining and the expressions of glial fibrillary acidic protein (GFAP) andβ-amyloid peptide 1–40 (Aβ1–40) were monitored via immunohistochemistry. The level of malondialdehyde (MDA) and the activities of glutathione peroxidase (GSH-Px) and lactate dehydrogenase (LDH) were measured using spectrophotometry. Main outcomes and results: The results showed that OA-treated rats exhibited marked neuronal damage accompanied by increased levels of Aβ1–40 peptide and MDA accumulation, decreased GFAP protein expression and reduced GSH-Px and LDH activity in the brain. SSF at three doses (25, 50 and 100 mg kg−1) dramatically reversed the OA-induced changes in the brains of rats. Conclusion: SSF-mediated amelioration of OA-induced neuronal damage in rats provides a rationale for assessing SSF as a means of to reducing tau hyperphosphorylation and Aβexpression in the treatment of Alzheimer’s disease. [ABSTRACT FROM AUTHOR]

Objective To investigate the prevalence rate of OSAHS between the Hani and Han nationalities in Yunnan Province, and explore the risk factors and pathogenesis regularity of OSAHS. Methods According to the rules of the case control study, 1135 Hani people and 1566 Han people were selected by cluster sampling. The suspected patients were screened via questionnaire, and OSAHS patients were confirmed by polysomnography (PSG).The prevalence and risk factors of OSAHS in Hani and Han nationalities were calculated. Rusults The prevalence rate of OSAHS in Hani and Han nationality was 3.70% and 3.96%, respectively. There was no significant difference in prevalence rate between the two nationalities (Z= 0.347, P > 0.5). The neck circumference, waist circumference, smoking history (middle and severe), and family history of snoring were risk factors of OSAHS. Conclusion The prevalence rate of OSAHS in Hani is basically the same as that in Han nationality. OSAHS is a multifactorial disease and severely endangers the public health, so more attention should be paid to it. [ABSTRACT FROM AUTHOR]

Excited states in 120I are investigated utilizing in-beam gamma-ray spectroscopy following the 114Cd(11B,5n) reaction at 70 MeV bombarding energy. A level scheme is constructed with states up to 9 MeV. The levels are classified into several bands and their possible configurations at low spins are discussed briefiy. Based on the linking transitions between different bands at higher spins, the excitation energy of the previously reported T1/2 = 53 min isomer is ascertained to be 72keV. Evidence showing the existence of an isomer at an excitation energy of 6.4 MeV is presented. [ABSTRACT FROM AUTHOR]

Through analyze the knitting data of computerized flat knitting machine, the knitting data is composed of static data and dynamic data categories according to the machine action type, and is given the form of the action data organization. According to the characteristics of the static data and dynamic data, Ethernet TCP and UDP mode is used to account the amount of data for two styles, the each needle transmission and a whole transmission for a weaving line, and to account transfer time for dynamic data. The account results show that TCP and UDP transmission mode can satisfy the control of computerized flat knitting machine time synchronization requirements. [ABSTRACT FROM AUTHOR]

To improve the autonomous ability, the obstacles-climbing module of a searching robot under mine disasters is built. Based on the model, the ability of obstacles-climbing robot is analyzed and an nested artificial fish-swarm algorithm ( NAFSA ) is developed to solve the automatic motion planning of the robot. The method adopts the AFAS in three layers of four groups which can weaken the coupling of the four variables, and uses the rapidly random exploring method for reducing the variables bounds to meet with the minimum changes of joint angles. Then, simulations in MATLAB show that this method can get the key joint angles more effectively and in less intervals than traditional method, and provide reference for the robot control. Finally, the obstacle-climbing experiment of double units mode is carried out, and the simulation result verifies that the robot can climb over the obstacle. [ABSTRACT FROM AUTHOR]

To design a high gain concentrator with high efficient, light weight, low aspect ratio and good uniformity of solar cell illumination lot a high concentration photovohaic system, the SMS (simultaneous multiple surfaces) method was used for simultaneous design of total internal reflection optical surfaces and refraction optical surfaces on the basis of conservation of etendue and edge-ray principle. In realizing that, the optical surface profiles of the concentrator was calculated and optimized using numeric method to complete the design of the concentrator including a primary lens and a secondary lens. The optimized concentrator has 1 000 X concentration, an aspect ratio less than 0.4 and acceptance angle of 1.5°. Moreover, the result of ray tracing of the concentrator indicates that high efficient more than 85% and good uniformity of the solar cell illumination can be achieved. Therefore, when the designed concentrator is applied to a high concentration photovohaic system with a 2-axis tracking system, an easy assembly process and high optical efficient can he realized. [ABSTRACT FROM AUTHOR]

In order to get a better convergence anti transition for passive bipedal robot research, this article analyzed the initial model of passive biped robot, i.e. the two-dimensional rimless-wheel model. Its dynamic model was constructed and its motion characteristic was analyzed with Adams. The effect of initial velocity, quality, foot radius, the number of spokes, the length of spoke, moment of inertia and slope gradient on the movement of rimless-wheel was analyzed. Results show that a right initial velocity and slope gradient, larger quality and foot radius, more and shorter spokes, as well as larger moment of inertia can lead to a fast and smooth cycle motion for rimless-wheel. [ABSTRACT FROM AUTHOR]

The g-factors of the intra-band states 12, 13, 14, 15 in a magnetic-rotational band built on the 11 state in 82Rb are measured for the first time by using a transient magnetic field-ion implantation perturbed angular distribution (TMF-IMPAD) method. The magnetic-rotational band in 82Rb is populated by the 60Ni(27Al,4pn)82Rb reaction, and the time-integral Larmor precessions are measured after recoil implantation into a polarized Fe foil. The calculation of g-factors is also carried out in terms of a semi-classical model of independent particle angular momentum coupling on the basis of the four-quasiparticle configuration π(g9/2)2 ⊗ π(p3/2, f5/2)⊗ &ngr;(g9/2). The measured and calculated g-factors are in good agreement with each other. The g-factors and deduced shear angles decrease with the increase of spin along the band. This clearly illustrates the shear effect of a step-by-step alignment of the valence protons and neutrons in magnetic rotation. The semi-classical calculation also shows that the alignment of the valence neutron angular momentum is faster than that of the valence protons, which results in a decrease of g-factors with increasing spin. The present results provide solid evidence of the shear mechanism of magnetic rotation. [ABSTRACT FROM AUTHOR]

For a better understanding of the essential characteristics of passive robot, making the research of model be a better guide to the design of actual prototype, methods of numerical simulation and verification of Adams were employed to research a two-dimensional pure passive walking model with round feet. Characteristics of the passive model were analyzed and the dynamic equations were derived with Lagrange Equation. Based on the phenomenon of dynamics of symmetric gait of the robot appearing to be a limit cycle in the phase space, a complete process of the simulation of steady-walking of this model was given with Matlab tool and the initial conditions of the steady-walking model were achieved. The dynamics and characteristics in each stage of the biped locomotion cycle were discussed. Adams was used to verify the simulation. This study will be the basis of stability analysis of the robot and a guide to the design of a passive robot prototype. [ABSTRACT FROM AUTHOR]

Studies vortex core dynamics in the Brusselator both near to and far from the Hopf bifurcation line for random and pair initial conditions. Vortex dynamics near the oscillatory instability; Vortex dynamics in the relaxation oscillation domain.