Discontinuous Research Articles

The design and clinical application of a new type of disposable heparin free dialysis tube

Objective To investigate the clinical effect of a new type of disposable heparin free dialysis tube in uremic patients without heparin dialysis. Methods A total of 110 patients without heparin dialysis were divided into control group and observation group by random digits table method with 55 cases each. Based on the same pre dialysis and dialysis for heparin saline flushing of discontinuous saline on the control group using the traditional dialysis pipe for hemodialysis without heparin, the observation group used disposable non heparin dialysis pipe for hemodialysis without heparin. The number of patients with venous catheter blockage, blood loss and completion of dialysis time in two groups was recorded. Results The number of patients with venous catheter blockage, blood loss and completion of dialysis time was 6, 6, 47 cases in control group and 0, 0, 54 cases in observation group. The differences were statistically significant (χ2=4.407, 4.407, 4.356, P<0.05). Conclusions The new disposable heparin free dialysis tube can reduce the loss of blood and prolong the treatment time, and the operation is simple, safe and effective, and has good application value and application prospect. Key words: Renal dialysis; Nursing care; Coagulation; Vein pot; Without heparin

Adjoint classes of Kurzweil–Stieltjes integrable functions

It is well known that functions of bounded variation, BV[a, b], and continuous functions, C[a, b], define two classes of functions which are adjoint with respect to the Riemann–Stieltjes integral. This means that: (1) if the integral $$\int _a^b f\,dg$$ exists for every function g in BV[a, b], then f belongs to C[a, b]; (2) if the integral $$\int _a^b f\,dg$$ exists for every function f in C[a, b], then g belongs to BV[a, b]. In this paper, we analyse whether the Kurzweil–Stieltjes integral mimics such a property of the Riemann–Stieltjes integral with respect to some classes of functions. In particular, we investigate the validity of (1) and (2) in the case when the integral is the Kurzweil–Stieltjes integral and C[a, b] is replaced by the class of regulated functions G[a, b] (i.e., functions with discontinuities of the first kind).

Quantification of the geometrical parameters of non-cylindrical folds

The geometrical parameters of natural folds are used by structural geologists to estimate finite strain and rheological properties of deformed rocks. The relation between geometry and rheology is well understood in cases of cylindrical folds, but is still limited for non-cylindrical folds, although the latter are frequent in nature. The sparsity of quantitative geometrical data of non-cylindrical folds can be explained by the small number of 3D exposures and by the lack of robust methods to quantify their geometrical parameters in 3D space. We present a new workflow, which can be used to quantify geometrical parameters of non-cylindrical folds. 3D fold geometry is described using fold wavelength, λ, arc-length, L, and amplitude, A. As most natural folds do not show ideal shapes, but are affected by various types of discontinuities, the new procedure is not fully automatic, but requires the manual selection of measuring profiles along which the geometrical parameters are constrained. The new workflow is tested using natural and experimentally produced non-cylindrical folds.The geometric parameters obtained can be used to improve our understanding of fold kinematics and fold mechanics and should assist the quantitative analysis of non-cylindrical folds present in gneiss and salt domes and in rocks containing reservoirs of hydrocarbons and minerals deposits.

A Convergence Analysis of Discontinuous Collocation Method for IAEs of Index 1 Using the Concept “Strongly Equivalent”

We introduce the concept “strongly equivalent” for integral algebraic equations (IAEs). This definition and its corresponding theorems construct powerful tools for the classifying and analyzing of IAEs (especially numerical analysis). The related theorems with short proofs provide powerful techniques for the complete convergence analysis of discretised collocation methods on discontinuous piecewise polynomial spaces.

Parameter dependence of acoustic quantities in a nonlinear internal wave duct

Parameter dependence of acoustic quantities in a nonlinear internal wave duct BJD, Matt Milone, YTL Ocean features with 3-D spatial variability in shallow water can significantly affect acoustic propagation. One example is a curved front modeled with a discontinuous sound speed change over a sloping shelf [Lin and Lynch, JASA-EL (2012)], which has an extension to a continuous sound-speed change. An approach using normal modes and perturbation approximations yields convenient formulas that show how acoustic quantities depend on environmental parameters [DeCourcy et al., ASA, Salt Lake City (2016)]. Another common 3-D example is nonlinear internal waves, with wave fronts that pairwise can produce acoustic ducting, radiating, and scattering effects often observed in field data. The previous approach is applied to this feature, using a well model with two sound-speed jumps for such a duct [Lin et al., (2013)]. Approximate formulas for acoustic wavenumbers and phase speeds are determined in order to estimate sensitivity to changes in environmental parameters. All mode types will be considered (whispering gallery, fully bouncing, and leaky), highlighting differences from those in the single-front example. [Work supported by ONR Grants N00014-14-1-0372 and N00014-11-1-0701.]

Calculated sound velocity and elastic moduli changes of FeTe0.5Se0.5 at the superconducting transition

The room temperature sound velocity in FeTe0.5Se0.5 superconductor has been measured using the pulsed-echo overlap ultrasonic technique. The samples were prepared using the solid-state reaction method at ambient pressure. Using these ultrasonic measurements we performed calculations that showed a step discontinuity in the bulk modulus, ∆BB=4ppm, Young's modulus, ∆YY=8ppm and longitudinal sound velocity, ∆vLvL=2ppm at Tc. The calculated acoustic Debye temperature, θD=334K indicated that FeTe0.5Se0.5 is slightly softer than the copper oxide based superconductor and hence the lower Tc. The calculated electron-phonon coupling in the two-dimensional van Hove scenario is, λvH=0.024.

Convergence Analysis of Piecewise Polynomial Collocation Methods for System of Weakly Singular Volterra Integral Equations of The First Kind

We study regularity of solutions of weakly singular Volterra integral equations of the first kind. We then study the numerical analysis of discontinuous piecewise polynomial collocation methods for solving such systems. The main purpose of this paper is the derivation of global convergent and super-convergent properties of introduced methods on the graded meshes. We apply relevant methods to a system of fractional differential equations and analyze them. The numerical experiments confirm the theoretical results.

Improved Temperature and Emissivity Separation Algorithm for Multispectral and Hyperspectral Sensors

The Temperature and Emissivity Separation (TES) algorithm was originally developed for the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER). This paper focuses on improving the TES algorithm. The main modification is the replacement of the normalized emissivity module with a new module, which is based on the smoothing of spectral radiance signatures. Smoothing is performed by estimating emissivity using an optimized approximation of the relationship between brightness temperature and emissivity. The improved TES algorithm, which is called Optimized Smoothing for Temperature Emissivity Separation (OSTES), was first tested on simulated data from three different sensors, namely, ASTER, Airborne Hyperspectral Scanner, and Thermal Airborne Spectrographic Imager. Processing simulated data with OSTES shows that it produces more accurate and precise temperature and emissivity retrievals than TES for samples with low spectral contrast. These results also show that the OSTES is less sensitive to variations in atmosphere and sample temperatures. The OSTES performance was secondly tested and compared with ASTER standard products. Testing showed that the OSTES temperature retrievals agree with AST_08 (kinetic temperature) but the emissivity retrievals differ substantially from AST_05 (surface emissivity). This implies that the ASTER standard products, AST_08 and AST_05, are not consistent with each other. Emissivities that are derived using temperatures from AST_08 and ASTER thermal surface radiances from AST_09T perform similar or worse when compared with OSTES emissivities. Emissivities delivered by AST_05 also exhibit step discontinuities, whereas the OSTES emissivitites are smoother over homogeneous surfaces. However, all emissivity spectra are affected by imperfect atmospheric corrections.

Singularly perturbed third-order semilinear boundary value problems with discontinuous coefficients

Singularly perturbed third-order semilinear boundary value problems with discontinuous coefficients

A Green Chemical Production: Obtaining Levulinic Acid from Pretreated Sugarcane Bagasse

The Bio Based Press wrote “The production of levulinic acid is gaining momentum”. Today, researches are focusing efforts to convert biomass on new chemicals platforms, including levulinic acid (LA), which has gained increased attention for being an attractive platform for products with high added value. LA can be obtained through the acid hydrolysis of some types of saccharides such as glucose and xylose, the constituent unit of cellulose and hemicelluloses. In this work, three substantial steps to convert biomass, in this case sugarcane bagasse, in LA were investigated. Sugarcane bagasse was pretreated with acid (121 °C, 1.0 % w/v H2SO4, and 80 min) and alkali delignificated (80 °C, 0.5 % w/v NaOH, and 90 min reaction time) both with 20 % w/v of solids loading. Experiments were carried in a discontinuous reactor at different variations of temperature (160, 170 and 180 °C), acid concentration (3, 7 and 5 % w/v H2SO4), hydrolysis reaction time (55, 75 and 95 min) and substrate loadings (6, 8 and 12 % w/v). This research has demonstrated that LA production at 170 °C, 5% w/v H2SO4, 75 min and 6 % w/v of solids loading conditions achieved a LA yield of 55.00 ± 0.36 % and selectivity about 45.65 ± 0.26 %.

The characteristics of proximal deep vein thrombosis after total knee and hip arthroplasty

Objective To analyze the characteristics of proximal deep vein thrombosis (DVT) after total joint arthroplasty. Methods 40 cases of proximal DVT were collected from May 2007 to October 2016 which were all diagnosed by lower limb venography or sonography. There were 9 males and 31 females aged from 38 to 86 years, average 67 years, and body mass index was from 16.94 to 31.25kg/m2, with an average of 24.3 kg/m2. 29 cases of THA patients and 11 cases of TKA patients. The anatomical distribution, size, radiological performance, local physical findings were recorded and multivariable analysis was performed to evaluate the relationship between distribution of proximal DVT and related parameters including age, gender (male/female), side of leg(left/right), surgery type(knee and hip), preoperative diagnosis(femoral neck fracture/other disease), time of diagnosis with DVT (during hospitalization/after discharge). Results Among 40 proximal DVT cases, 31 cases diagnosed by phlebography and 9 cases were diagnosed by ultrasound. 2 cases were isolated proximal DVT while 38 cases connected with distal DVTs. 9 cases of blood clots in the proximal and distal thrombosis connected discontinuously. There was no isolated proximal DVT in TKA group and 10 cases (90.9%) of blood clots in the proximal and distal thrombosis connected continuously while there were 2 cases (6.9%) isolated proximal DVTs in THA group and 21 (77.8%) of blood clots in the proximal and distal thrombosis connected discontinuously, and there was no statistic significant difference between the two groups. The average length of proximal was 8.85±9.31cm (range from 2-35cm) with 5.0±2.05 cm in TKA group and 10.31±10.55 cm in THA group. A significant difference was found between the 2 groups (P=0.014). 13 cases located in femoral veins and upper venous region which were all from THA group. There was a significant difference in the distribution between surgery type and preoperative diagnosis. However, there was no significant difference between other potential factors and distribution of proximal DVT. 25 cases accepted the evaluation of symptom of DVT before scanning. However, no significant difference were found in edema, VAS score, Homans sign, Neuof sign between 9 TKA and 16 THA cases. Conclusion Proximal DVTs after knee and hip arthroplasty are more preferred to connect with distal DVT continuously. Surgery type and preoperative diagnosis have a significant effect on the distribution of proximal DVT. Proximal DVTs in THA and patients with preoperative femoral neck fracture could be more easily involving femoral veins and upper parts. Key words: Arthroplasty, replacement; Venous thrombosis; Phlebography

Reliability analysis of the slab panel method (SPM) for the design of composite steel floors in severe fires

PurposeThis paper aims to present a reliability analysis of the slab panel method (SPM) for the design of composite steel floors in severe fires. Rather than seeking to accurately define failure levels, this paper highlights areas of uncertainty in design and their effect on design results, whilst providing approximate reliability levels.Design/methodology/approachA Monte Carlo simulation has been conducted using the SPM design procedure to produce probability density functions of floor capacity for various floor layouts. Statistical input variables were obtained from the literature. Different configurations, geometries and fire severities are included to demonstrate how predicted floor capacities are influenced.FindingsFrom the research presented, it is clear that the predicted reliability of SPM systems varies relative to a large number of criteria, but especially parameters related to fire loading. Predicted capacities are shown to be conservative compared to results of furnace and large-scale natural fire tests, which exhibit higher fire resistance. Due to distinct fire hazard categories with associated input values, there are step discontinuities in capacity graphs.Originality/valueLimited research has been done to date on the reliability of structures in fire as discussed in this paper. It is important to verify the reliability levels of systems to ensure that partial and global factors of safety are adequate. Monte Carlo simulations are shown to be effective for calculating the average floor capacities and associated standard deviations. The presentation of probability density functions for composite floors in severe fires is novel.

Modelling the Shear Behaviour of Clean Rock Discontinuities Using Artificial Neural Networks

Since the mechanical behaviour of rock masses is influenced by the shear behaviour of their discontinuities, analytical models are being developed to describe the shear behaviour of rock discontinuities. The aim of this paper is to present a model to predict the shear behaviour of clean rock discontinuities developed by using artificial neural networks (ANN), as an alternative to the existing analytical models which sometimes require certain parameters obtained from large-scale laboratory tests which are not always available. Results from direct shear tests on different boundary conditions and types of discontinuities have been used to develop this ANN model, whose input parameters contain the boundary normal stiffness, the initial normal stress, the joint roughness coefficient, the compressive strength of the intact rock, the basic friction angle and the horizontal displacement of a joint. This proposed ANN model fits the experimental data better than some existing analytical models, and it can satisfactorily describe how governing parameters influence the shear behaviour of clean rock discontinuities. This paper also presents a practical application where the proposed ANN model is used to analyse the stability of a rock slope.

Використання математичної моделі динамічної системи «екіпаж-колія» для досліджень сил взаємодії рухомого складу та колії метрополітенів

Most studies that have examined the interaction track and rolling stock, defined vertical or horizontal lateral forces acting on the track by driving crews in straight and curved sections of track.However, in terms of metro (small radius curves, especially special rolling stock, especially the modes of rolling stock) should be considered significant nonlinearity dependence, including nonlinearity discontinuous type. As for nonlinear systems superposition principle cannot be applied, research carried out on non-linear spatial model.This publication held definition of vertical and horizontal transverse dynamic forces arising from the interaction of rolling stock and tracks underground. Determination was carried out on the basis of previous studies in which developed models and methods of calculation of such forces. Determined the conditions for the emergence and importance of nonlinear forces guiding the light rail rigidity yarn at its bending, twisting and energy dissipation in the horizontal plane. Included impact tilt rails and super elevation in curves.The article shows the implementation of mathematical models using Matcad. The novelty of the approach studies the interaction of rolling stock and metro lines is the account of and evaluation of exactly horizontal transverse forces.

Stable and convergent fully discrete interior–exterior coupling of Maxwell’s equations

Maxwell’s equations are considered with transparent boundary conditions, for initial conditions and inhomogeneity having support in a bounded, not necessarily convex three-dimensional domain or in a collection of such domains. The numerical method only involves the interior domain and its boundary. The transparent boundary conditions are imposed via a time-dependent boundary integral operator that is shown to satisfy a coercivity property. The stability of the numerical method relies on this coercivity and on an anti-symmetric structure of the discretized equations that is inherited from a weak first-order formulation of the continuous equations. The method proposed here uses a discontinuous Galerkin method and the leapfrog scheme in the interior and is coupled to boundary elements and convolution quadrature on the boundary. The method is explicit in the interior and implicit on the boundary. Stability and convergence of the spatial semidiscretization are proven, and with a computationally simple stabilization term, this is also shown for the full discretization.

Ser mochileiro: uma constituição social e pessoal do “mochilar”

Este artigo discute e apresenta a representação social e pessoal do ser mochileiro contemporâneo, aproximando a construção histórica-social-acadêmica e a óptica dos sujeitos mochileiros, a partir dos múltiplos olhares acerca dos viajantes e do ato de viajar. Partindo da aproximação/diferenciação entre turistas e viajantes, e da mudança do foco econômico das viagens para o aspecto relacional, essa investigação adentra o universo subjetivo dos mochileiros desvelando sua constituição identitária. Essa intrínseca relação sujeito-ação, viajante-viagem, que desloca o sujeito a um tempo/espaço descontínuos e provoca, pela vivência da alteridade, um duplo estranhamento no ser e estar diferente de si mesmo e do outro, faz com que a “mochilagem”, para além de uma forma alternativa de viagem, seja uma experiência de vida e represente um jeito de ser e estar no mundo: o ser mochileiro. Para alcançar os sentidos e significados dessa experiência humana, utilizou-se a abordagem qualitativa com múltiplos métodos de pesquisa: Pesquisa bibliográfica; Pesquisa de campo com observação de campo; Entrevistas semiestruturadas; Amostragem pelo método bola de neve e análise de dados.

Analysis of adverse drug reactions in multidrug-resistant pulmonary tuberculosis patients

Objective To analyze the adverse drug reactions (ADR) during the standardized treatment of multidrug-resistant pulmonary tuberculosis (MDR-PTB), and to evaluate its impact on treatment outcomes. Methods A retrospective study was carried out on 305 MDR-PTB patients. Medical records of clinical treatment and laboratory examinations were collected, and the ADR data were analyzed.Chi-square test or Fisher exact test was used for discontinuous variables, and t test or non-parametric test was used for continuous variables. Results Among 305 MDR-PTB patients , 282 (92.5%) had at least one ADR. The major ADR were gastrointestinal reaction (46.9%), thyroid dysfunction (41.3%), hypokalemia (34.1%), renal injury (29.8%), hematological system impairment (21.6%), hepatotoxicity (19.0%), arthralgia or courbature (11.1%), and ototoxicity and vestibular dysfunction (8.5%). Sex, age, native place, the history of using second-line TB drugs or the history of diabetes mellitus had no significant effect on the incidence of ADR (all P>0.05). As per the Naranjo causality assessment of ADR, 34 patients had definite, 236 had probable, 12 had possible and 0 had doubtful causal relations. Among the 282 cases with ADR, 175 (62.1%) patients continued the original treatment regimen, 89 (31.6%) patients changed or stopped ADR-related drugs, only 18 (6.4%) cases stopped MDR-PTB treatment. The episodes of ADR had no significant effect on the treatment outcomes (P>0.05). Conclusions Although ADR are common in MDR-PTB patients during the treatment course, most of the ADR can be managed. Through timely monitoring and appropriate treatment of ADR, most of the patients could continue MDR-PTB treatment. Key words: Tuberculosis, pulmonary; Tuberculosis, multidrug-resistant; Therapy; Adverse drug reactions

High order solution of Poisson problems with piecewise constant coefficients and interface jumps

We present a fast and accurate algorithm to solve Poisson problems in complex geometries, using regular Cartesian grids. We consider a variety of configurations, including Poisson problems with interfaces across which the solution is discontinuous (of the type arising in multi-fluid flows). The algorithm is based on a combination of the Correction Function Method (CFM) and Boundary Integral Methods (BIM). Interface and boundary conditions can be treated in a fast and accurate manner using boundary integral equations, and the associated BIM. Unfortunately, BIM can be costly when the solution is needed everywhere in a grid, e.g. fluid flow problems. We use the CFM to circumvent this issue. The solution from the BIM is used to rewrite the problem as a series of Poisson problems in rectangular domains—which requires the BIM solution at interfaces/boundaries only. These Poisson problems involve discontinuities at interfaces, of the type that the CFM can handle. Hence we use the CFM to solve them (to high order of accuracy) with finite differences and a Fast Fourier Transform based fast Poisson solver. We present 2-D examples of the algorithm applied to Poisson problems involving complex geometries, including cases in which the solution is discontinuous. We show that the algorithm produces solutions that converge with either 3rd or 4th order of accuracy, depending on the type of boundary condition and solution discontinuity.

Regulatory effect of vitamin D on the expression of occludin in the intestinal epithelial cells of neonatal rats with necrotizing enterocolitis

Objective To investigate the expression of occludin in the intestinal epithelial cells of neonatal rats with necrotizing enterocolitis (NEC). The influence of vitamin D on NEC and the expression of occludin was also explored. Methods Sixty neonatal Wistar rats from different litters were divided into four groups 48 hours after birth: 10 in the breast-fed+ control group, 10 in the breast-fed + vitamin D group, 20 in the NEC+ control group and 20 in the NEC+ vitamin D group.In groups with NEC, neonatal rats were separated from their mothers and treated with rat milk substitute+ hypoxia+ hypothermia.In groups with vitamin D treatment, paricalcitol was given through intraperitoneal injection 30 minutes before, one day and two days after the induction of NEC.The tissue was harvested from the ileum of the rats 72 hours after induction of NEC.Microscopically, the tissue was assessed according to the Nadler scoring system.The expression and location of occludin was observed after immunofluorescence staining.Western blotting was performed and quantified to compare the expression of occludin among groups. Results In NEC rats, the intestinal structure was destructed.Separation of the submucosal or muscular layer, discharge or disappearance of the villa was accompanied by necrosis of the intestinal cells.Vitamin D treatment could significantly alleviate those changes, with the Nadler score 1.70±0.21 compared to 2.90±0.23 without vitamin D treatment(P<0.01). The expression of occludin was decreased in NEC rats and vitamin D could partly rescue this decrease(P<0.01). The distribution of occludin was sparse and discontinuous in NEC rats while after vitamin D treatment, the distribution was maintained even and continuous. Conclusion The expression of occludin in intestinal epithelial cells is significantly reduced in NEC rat.Vitamin D treatment may inhibit the development of NEC by maintaining the expression of occludin. Key words: Occludin; Intestinal epithelial cells; Vitamin D; Necrotizing enterocolitis

Modeling and Predicting of MODIS Leaf Area Index Time Series Based on a Hybrid SARIMA and BP Neural Network Method

The modeling and predicting of vegetation Leaf area index (LAI) is an important component of land surface model and assimilation of remote sensing data. The MODIS LAI product (i.e. MOD15A2) is one of the most widely used LAI data sources. However, the time series of MODIS LAI contains some data of low quality. For example, because of the influence of the cloud, aerosol, etc., the MODIS LAI presents the characteristics of the discontinuous in time and space. In fact, the time series of MODIS LAI include both linear and nonlinear components, which cannot be accurately modeled and predicted by either linear method or nonlinear method alone. In this paper, the original LAI time series data were first smoothed with Savitzky-Golay (SG) filtration and linear interpolation; SARIMA, BP neural network and a hybrid method of SARIMA-BP neural network were then used for modeling and predicting MODIS LAI time series. The SARIMA-BP neural network combined both SARIMA and BP neural network, which could model the linear and the nonlinear component of MODIS LAI time series respectively. That is, the final result of SARIMA-BP neural network was the sum of results of the two methods. Experiments showed that the time series of MODIS LAI that were smoothed with the SG filtration and linear interpolation were more smooth than original time series, with a determination coefficient up to 0.981, closer to 1 than that of SARIMA (0.941) and BP neural network (0.884); the correlation coefficient between SARIMA-BP neural network and the observation is 0.991, higher than that of between SARIMA (0.971) or BP neural network (0.942) SARIMA and the observation. Thus, it can be concluded that, the proposed SARIMA-BP neural network method can better adapt to the LAI time series, and it outperforms the SARIMA and BP neural network methods.