Doing Science: How to optimise patient and public involvement in your research

This paper considers how best to achieve patient and public involvement in research and how to get the most out of it http://ow.ly/R0hwV

Doing Science: How to optimise patient and public involvement in your research

This paper considers how best to achieve patient and public involvement in research and how to get the most out of it http://ow.ly/R0hw

Effective photon mass and exact translating quantum relativistic structures

Using a variation of the celebrated Volkov solution, the Klein-Gordon equation for a charged particle is reduced to a set of ordinary differential equations, exactly solvable in specific cases. The new quantum relativistic structures can reveal a localization in the radial direction perpendicular to the wave packet propagation, thanks to a non-vanishing scalar potential. The external electromagnetic field, the particle current density and the charge density are determined. The stability analysis of the solutions is performed by means of numerical simulations. The results are useful for the description of a charged quantum test particle in the relativistic regime, provided spin effects are not decisive

Solutions for certain classes of Riccati differential equation

We derive some analytic closed-form solutions for a class of Riccati equation y'(x)-\lambda_0(x)y(x)\pm y^2(x)=\pm s_0(x), where \lambda_0(x), s_0(x) are C^{\infty}-functions. We show that if \delta_n=\lambda_n s_{n-1}-\lambda_{n-1}s_n=0, where \lambda_{n}= \lambda_{n-1}^\prime+s_{n-1}+\lambda_0\lambda_{n-1} and s_{n}=s_{n-1}^\prime+s_0\lambda_{k-1}, n=1,2,..., then The Riccati equation has a solution given by y(x)=\mp s_{n-1}(x)/\lambda_{n-1}(x). Extension to the generalized Riccati equation y'(x)+P(x)y(x)+Q(x)y^2(x)=R(x) is also investigated.Comment: 10 page

Solvable Systems of Linear Differential Equations

The asymptotic iteration method (AIM) is an iterative technique used to find exact and approximate solutions to second-order linear differential equations. In this work, we employed AIM to solve systems of two first-order linear differential equations. The termination criteria of AIM will be re-examined and the whole theory is re-worked in order to fit this new application. As a result of our investigation, an interesting connection between the solution of linear systems and the solution of Riccati equations is established. Further, new classes of exactly solvable systems of linear differential equations with variable coefficients are obtained. The method discussed allow to construct many solvable classes through a simple procedure.Comment: 13 page

A time-dependent density functional theory scheme for efficient calculations of dynamic (hyper)polarizabilities

We present an efficient perturbative method to obtain both static and dynamic polarizabilities and hyperpolarizabilities of complex electronic systems. This approach is based on the solution of a frequency dependent Sternheimer equation, within the formalism of time-dependent density functional theory, and allows the calculation of the response both in resonance and out of resonance. Furthermore, the excellent scaling with the number of atoms opens the way to the investigation of response properties of very large molecular systems. To demonstrate the capabilities of this method, we implemented it in a real-space (basis-set free) code, and applied it to benchmark molecules, namely CO, H2O, and paranitroaniline (PNA). Our results are in agreement with experimental and previous theoretical studies, and fully validate our approach.Comment: 9 pages, 4 figure

Criterion for polynomial solutions to a class of linear differential equation of second order

We consider the differential equations y''=\lambda_0(x)y'+s_0(x)y, where \lambda_0(x), s_0(x) are C^{\infty}-functions. We prove (i) if the differential equation, has a polynomial solution of degree n >0, then \delta_n=\lambda_n s_{n-1}-\lambda_{n-1}s_n=0, where \lambda_{n}= \lambda_{n-1}^\prime+s_{n-1}+\lambda_0\lambda_{n-1}\hbox{and}\quad s_{n}=s_{n-1}^\prime+s_0\lambda_{k-1},\quad n=1,2,.... Conversely (ii) if \lambda_n\lambda_{n-1}\ne 0 and \delta_n=0, then the differential equation has a polynomial solution of degree at most n. We show that the classical differential equations of Laguerre, Hermite, Legendre, Jacobi, Chebyshev (first and second kind), Gegenbauer, and the Hypergeometric type, etc, obey this criterion. Further, we find the polynomial solutions for the generalized Hermite, Laguerre, Legendre and Chebyshev differential equations.Comment: 12 page

Identifikasi Bakteri pada Sputum Pasien Penyakit Paru Obstruktif Kronis Eksaserbasi Akut di RSUD Arifin Achmad Provinsi Riau

Chronic Obstructive Pulmonary Disease is characterized by persistent airflow limitation, progressive, associated with chronic inflammatory response caused by noxious particles and gases. The severity of COPD depends on its exacerbations and comorbidities of each individual. One of the most factors cause exacerbation of COPD is bacterial infection. The purpose of this study was to know the percentage of bacterial infection cause the exacerbation and the pattern of its etiologic bacteria. The samples were sputum of hospitalized patients with exacerbation of COPD in the Lung room RSUD Arifin Achmad Riau Province. The sputum specimen was collected using sterile containers and subjected to Gram's stain, culture and biochemical reactions. This study obtained 100% of sputum cultur for pathogenic bacteria was possitive in all 23 cases. The most etiologic bacteria were gram negative 83% which is Klebsiella sp. as the leading bacteria 48%, followed by Acinetobacter sp. 22% and Enterobacter sp. 13%. Gram possitive Staphylococcus aureus were found about 17% in exacerbation of COPD