Construction and validation of a scale of assessment of self‐care behaviors with arteriovenous fistula in hemodialysis

Several guidelines recommend the importance of educating the patient about the care of vascular access. Nurses have a key role in promoting the development of self‐care behaviors by providing the necessary knowledge to patients, so that they develop the necessary skills to take care of the arteriovenous fistula (AVF). This article describes the process of building a scale of assessment of self‐care behaviors with arteriovenous fistula in hemodialysis (ASBHD‐AVF). This is a cross‐sectional study in which the development, construction, and validation process followed the directions of the authors Streiner and Norman. This is a convenience sample, sequential, and nonprobabilistic constituted by 218 patients. The study was conducted in two stages during 2012–2014. The first phase corresponds to the scale construction process, 64 patients participated, while the second corresponds to the evaluation of metric properties and 154 patients participated. The principal component analysis revealed a two‐factor structure, with factorial weights between 0.805 and 0.511 and between 0.700 and 0.369, respectively, explaining 39.12% of the total variance of the responses. The Cronbach's alpha of the subscale management of signs and symptoms is 0.797 and from the subscale prevention of complications is 0.722. The ASBHD‐AVF revealed properties that allow its use to assess the self‐care behaviors in the maintenance and conservation of the AVF.     

手机游戏用户体验评价量表开发与验证

目的开发适用于手机游戏的用户体验评价量表。方法基于心流理论和游戏平台的固有特性确定初始量表,招募380名在校学生和企业职工作为被试,通过手机APP问卷星和现场填写两种形式收集问卷,分析其信效度。结果量表包括22个题目,分为6个维度,累计方差解释率67.28%。量表的结构拟合度较好(NFI=0.920,IFI=0.976,TLI=0.970,RMSEA=0.046)。各维度内部一致性系数在0.876-0.927之间,组合信度均在0.854-0.947之间,平均抽取方差的平方根均大于各维度间的相关系数。将量表应用于两款手机游戏(皇室战争H和地铁跑酷D)用户体验评价,结果表明游戏H用户体验水平优于游戏D,在反馈、沉浸、挑战和社交4个维度及用户体验总得分上均表现出显著性差异,而在移动和控制两个维度上不存在显著性差异,这与游戏本身分析结果相一致。结论新量表适用于手机游戏用户体验评价,为后续手机游戏用户体验研究打下良好基础。     

Development and validation of a rapid HPLC method for the determination of ketotifen in pharmaceuticals

In the present study, a simple, sensitive, rapid, and stability-indicating high performance liquid chromatographic (HPLC) method with ultraviolet detection for the analysis of ketotifen was developed and validated. The method was applied to the determination of ketotifen in pharmaceutical formulations (tablets and syrups). The HPLC method utilized isocratic elution technique with a reversed phase C8 column, detection at 297 nm and a mixture of methanol, triethylamine phosphate buffer (pH 2.8; 0.04 M), and tetrahydrofuran (43: 55: 2, v/v/v) as mobile phase at a flow rate of 1.2 mL/min. Total analysis time was about 7 min with typical retention time of ketotifen of about 5 min. The method was validated for selectivity, linearity, accuracy, and precision following International Conference of Harmonization, 1996 (ICH) recommendations. Due to its simplicity and accuracy, the method can be used for routine quality control analysis.     

Crack aspect development curves and fatigue life prediction for surface cracks at weld toes in the presence of residual stress

An engineering procedure is proposed for estimating the crack growth behaviour and fatigue lives of semi-elliptical surface cracks at weld toes, based on a database of stress intensity factors. Some examples of crack aspect development curves (CADC) are given for some typical cracked welded joints subjected to service loading and residual stress conditions. The significance for predicting fatigue life according to the natural crack growth path, namely along the CADC, is emphasized through examples.     

Development and validation of a dissolution test for lodenafil carbonate based on in vivo data

Introduction: Lodenafil carbonate is a phosphodiesterase type 5 inhibitor used for the treatment of erectile dysfunction. Currently, there is no dissolution test reported for lodenafil carbonate and this drug is not listed in any pharmacopoeia.

Objective: The present study focused on the development and validation of a dissolution test for lodenafil carbonate tablets, using a simulated absorption profile based on in vivo data.

Methods: The appropriate conditions were determined after testing sink conditions. Different conditions as medium, surfactant concentration and rotation speed were evaluated. The percentage of dose absorbed was calculated by deconvolution, using the Wagner–Nelson method.

Results: According to the obtained results, the use of 0.1?M HCl?+?1.5% SLS (900?mL, at 37?+?0.5?°C) as the dissolution medium, paddles at 25?rpm were considered adequate. The samples were quantified by UV spectroscopy at 295?nm and the validation was performed according to international guidelines. The method showed specificity, linearity, accuracy and precision, within the acceptable range. Kinetics of drug release was better described by the first-order model.

Conclusion: The proposed dissolution test can be used for the routine quality control of lodenafil carbonate in tablets.     

复合材料螺接修理结构参数化建模分析工具开发及验证

螺接修理在复合材料结构的临时性修理,尤其是战伤修理中应用较广泛。然而其修理设计过程较复杂,建模分析难度较大,难以满足工程快速定参的需要。本文针对含穿透损伤复合材料层合板的螺接修理问题,采用VB.NET结合p型有限元技术,开发了一套参数化的建模分析工具。分析工具通过界面读取修理结构的几何参数、螺栓布局、螺栓大小、载荷、材料属性等参数,自动创建有限元模型并进行求解。根据求解结果,分析工具可为用户提供修理结构的螺栓载荷、钉载比例、危险孔孔边应力等。另外,通过引入有限断裂力学,结合两级模型分析技术可预测得到修理结构的失效强度和失效位置。最后,采用典型算例对分析工具的有效性进行了验证。     

大型空分设备冷箱的钢结构应力计算分析

介绍了48000m3/h空分设备冷箱所受主要载荷:珠光砂、风载荷和地震载荷的计算,分析了冷箱钢结构中的关键部位在组合应力作用下的受力情况及取材。     

Evaluation of the T-stress and stress intensity factor for a cracked plate in general case using eigenfunction expansion variational method

This paper investigates the T-stress and stress intensity factor for a cracked plate in general case. In the general case, the shape of boundary and the applied loading are arbitrary. The eigenfunction expansion variational method (EEVM) is developed to evaluate the T-stress and stress intensity factor. For the traction boundary value problem, the EEVM is equivalent to the theorem of least potential energy in elasticity. Therefore, the EEVM possesses a clear physical meaning and it does not depend on any boundary collocation scheme. Several numerical examples are presented, which include: (1) a line crack in circular plate and (2) a line crack in rectangular plate. Numerical examination for convergence in an example is carried out.     

An analytical solution for the effect of initial stress,rotation, magnetic field and a periodic loading in a thermo-viscoelastic medium with a spherical cavity

In this article, an analytical solution for the effect of initial stress, the rotation, and the relaxation times in a magneto-thermo-viscoelastic homogeneous medium with a spherical cavity subjected to periodic loading is presented. The distribution of displacements, temperature, and stresses in a homogeneous medium, in the context of generalized thermo-elasticity using the Green-Lindsay (GL) theory is discussed and obtained in analytical form. The results are displayed graphically to illustrate the effect of initial stress, the rotation, relaxation times, magnetic field, and viscoelasticity. Comparisons are made with the previous work in the absence of rotation and initial stress.     

An eigenfunction expansion solution for three-dimensional stress field in the vicinity of the circumferential line of intersection of a bimaterial interface and a hole

An asymptotic solution pertaining to the stress field in the neighborhood of the circumferential line of intersection of an interface of a two-layer plate made of dissimilar isotropic materials and a through-hole, subjected to far-field extension/bending (mode I), inplane shear-twisting (mode II) and torsional (mode III) loadings, is presented. A local orthogonal curvilinear coordinate system (, , ), is selected to describe the local deformation behavior of the afore-mentioned plate in the vicinity of the afore-mentioned circumferential line of intersection. One of the components of the Euclidean metric tensor, namely g ₃₃, is approximated (/a1) in the derivation of the kinematic relations and the ensuing governing system of three partial differential equations. Four different combinations of boundary conditions are considered: (i) open hole (free-free), (ii) hole fully filled with an infinitely rigid plug (clamped-clamped), (iii) hole partially (i.e., in the layer 2) filled with an infinitely rigid plug (free-clamped), and (iv) hole partially (i.e., in the layer 1) filled with an infinitely rigid plug (clamped-free). The computed eigenvalues for the clamped-free boundary condition can be obtained from their free-clamped counterparts by replacing G ₂ by G ₁ and ₂ by ₁, and vice versa. These two boundary conditions are then equivalent in the complementary sense. Numerical results presented include the effect of the ratio of the shear moduli of the layer materials, and also Poisson's ratios on the computed lowest eigenvalues.     

Development and validation of a versatile HPLC-DAD method for simultaneous determination of the antiviral drugs daclatasvir,ledipasvir, sofosbuvir and ribavirin in presence of seven potential impurities. Application to assay of dosage forms and dissolution studies

This study describes a simple, sensitive, specific and generic HPLC-DAD method for simultaneous determination of four drugs prescribed for treatment of Hepatitis C Virus (HCV) infection. Investigated drugs include daclatasvir (DAC), ledipasvir (LED), sofosbuvir (SOF) and ribavirin (RIB). Successful separation was accomplished using Thermohypersil BDS-C8 column (4.6?×?250?mm, 5?µm) with gradient elution of the mobile phase consisted of mixed phosphate buffer pH 7.5 and methanol. Gradient elution started with 25% methanol, ramped up linearly to 80% in 15?min then kept constant till the end of the run. Flow rate was 1.5?mL/min. Peak areas were measured at 235, 260, 315, and 332?nm for RIB, SOF, DAC, and LED, respectively. Peaks of the analytes were perfectly resolved with retention times 2.0, 12.1, 14.7, and 17.2?min for RIB, SOF, DAC, and LED, respectively. The developed method was validated according to ICH guidelines with respect to system suitability, linearity, ranges, accuracy, precision, specificity, robustness, and limits of detection and quantification. The proposed method showed good linearity in the ranges 5–500, 2–300, 0.5–75, and 0.5–75?µg/mL for RIB, SOF, DAC, and LED respectively. Limits of detection were 0.10–0.66?μg/mL for the analyzed drugs. Specificity was established by separation of target drugs from 7 process-related impurities for SOF including its major metabolite (GS-331007). Applicability of the proposed method to real life situations was assessed through the analysis of four different pharmaceutical formulations and satisfactory results were obtained. Additionally, dissolution profiles of the 4 drugs were studied using the developed method.     

Development of an osmotically-driven pellet coated with acrylic copolymers (Eudragit® RS 30 D) for the sustained release of oxymatrine,a freely water soluble drug used to treat stress ulcers (I): in vitro and in vivo evaluation in rabbits

Purpose: To develop an osmotically-driven pellet coated with polymeric film for sustained release of oxymatrine (OMT), a freely water soluble drug.

Methods: Pellet containing OMT and sodium chloride (NaCl), an osmotically active agent, were prepared by extrusion/spheronization and then coated with acrylic copolymers (Eudragit^® RS 30 D) by the fluidized bed coating process. In vitro release and swelling behavior studies were employed to optimize and to evaluate the sustained-release behavior from the osmotically-driven pellets with film coated. Finally, in vivo evaluation in rabbits was employed to investigate the sustained plasma level of OMT and its active metabolite matrine.

Results: It was found that the F3 formulation, prepared with 20% NaCl and an 8% coating level, showed a continuous NaCl-induced water influx into the pellets providing a gradual sustained release of OMT for over 12?h. Finally, we confirmed that oral OMT with sustained release led to a gradual sustained plasma profile of both OMT, with a reduction in its bioavailability, and MT with an increase in the bioavailability compared with that of oral OMT with immediate release. Conclusions: The pharmaceutical parameters obtained suggested the potential usefulness of oral OMT with sustained release for the treatment of stress ulcers, as well as reducing the risk of MT-induced side effects.