969 research outputs found

    Optimal parameter for the SOR-like iteration method for solving the system of absolute value equations

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    The SOR-like iteration method for solving the absolute value equations~(AVE) of finding a vector xx such that Axxb=0Ax - |x| - b = 0 with ν=A12<1\nu = \|A^{-1}\|_2 < 1 is investigated. The convergence conditions of the SOR-like iteration method proposed by Ke and Ma ([{\em Appl. Math. Comput.}, 311:195--202, 2017]) are revisited and a new proof is given, which exhibits some insights in determining the convergent region and the optimal iteration parameter. Along this line, the optimal parameter which minimizes Tν(ω)2\|T_\nu(\omega)\|_2 with Tν(ω)=(1ωω2ν1ω1ω+ω2ν)T_\nu(\omega) = \left(\begin{array}{cc} |1-\omega| & \omega^2\nu \\ |1-\omega| & |1-\omega| +\omega^2\nu \end{array}\right) and the approximate optimal parameter which minimizes ην(ω)=max{1ω,νω2}\eta_{\nu}(\omega) =\max\{|1-\omega|,\nu\omega^2\} are explored. The optimal and approximate optimal parameters are iteration-independent and the bigger value of ν\nu is, the smaller convergent region of the iteration parameter ω\omega is. Numerical results are presented to demonstrate that the SOR-like iteration method with the optimal parameter is superior to that with the approximate optimal parameter proposed by Guo, Wu and Li ([{\em Appl. Math. Lett.}, 97:107--113, 2019]). In some situation, the SOR-like itration method with the optimal parameter performs better, in terms of CPU time, than the generalized Newton method (Mangasarian, [{\em Optim. Lett.}, 3:101--108, 2009]) for solving the AVE.Comment: 23 pages, 7 figures, 7 table

    Self-partitioning SlipChip for slip-induced droplet formation and human papillomavirus viral load quantification with digital LAMP

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    Human papillomavirus (HPV) is one of the most common sexually transmitted infections worldwide, and persistent HPV infection can cause warts and even cancer. Nucleic acid analysis of HPV viral DNA can be very informative for the diagnosis and monitoring of HPV. Digital nucleic acid analysis, such as digital PCR and digital isothermal amplification, can provide sensitive detection and precise quantification of target nucleic acids, and its utility has been demonstrated in many biological research and medical diagnostic applications. A variety of methods have been developed for the generation of a large number of individual reaction partitions, a key requirement for digital nucleic acid analysis. However, an easily assembled and operated device for robust droplet formation without preprocessing devices, auxiliary instrumentation or control systems is still highly desired. In this paper, we present a self-partitioning SlipChip (sp-SlipChip) microfluidic device for the slip-induced generation of droplets to perform digital loop-mediated isothermal amplification (LAMP) for the detection and quantification of HPV DNA. In contrast to traditional SlipChip methods, which require the precise alignment of microfeatures, this sp-SlipChip utilized a design of “chain-of-pearls” continuous microfluidic channel that is independent of the overlapping of microfeatures on different plates to establish the fluidic path for reagent loading. Initiated by a simple slipping step, the aqueous solution can robustly self-partition into individual droplets by capillary pressure-driven flow. This advantage makes the sp-SlipChip very appealing for the point-of-care quantitative analysis of viral load. As a proof of concept, we performed digital LAMP on an sp-SlipChip to quantify human papillomaviruses (HPVs) 16 and 18 and tested this method with fifteen anonymous clinical samples

    Effects of nutritional nursing intervention based on glycemic load for patient with gestational diabetes mellitus

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    Objectives: To determine the effects of nutritional nursing intervention based on glycemic load (GL) for patients with gestational diabetes mellitus. Material and methods: One hundred thirty-four patients diagnosed with gestational diabetes mellitus at our hospital were selected from March 2015 to March 2017 and randomly divided into the observation (n = 67) and control groups (n = 67). All of the patients in the observation and control groups received conventional nutritional nursing. In addition, the patients in the observation group received nutritional nursing intervention based on GL. The changes in blood glucose levels and pregnancy outcomes were compared between the two groups after intervention. Results: There were significant differences in fasting blood glucose (FBG) and the 2h postprandial glucose (2hPG) levels between the two groups (P &lt; 0.05). There was a lower incidence of premature delivery, fetal macrosomia, eclampsia, preg- nancy hypertension syndrome, and fetal distress in the observation group. Conclusions: Nutritional nursing intervention based on GL is more effective than traditional nutritional nursing for patients with gestational diabetes, and can effectively control the blood glucose level, reduce the incidence of pregnant complica- tions, and improve the pregnancy outcome. Thus, nutritional nursing intervention based on GL deserves to be popularized.

    Microstructures and Properties of Extruded Al-0.6Mg-0.6Si Aluminium Alloy for High-speed Vehicle

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    AbstractThe Al-0.6Mg-0.6Si aluminium alloy was extruded for high-speed vehicle. The microstructure and mechanical property of extruded Al-0.6Mg-0.6Si aluminium alloy were investigated. The results of experimentation show that the tensile strength of extruded Al-0.6Mg-0.6Si aluminum alloy is above of 245MPa, and the percentage elongation after fracture is better than 8%. The microstructure is rolling structure, and the coarse second phases distribute in α-Al solid solution matrix structure. The second phases are inclusions, coarse stable phases of β′ (Mg2Si) or their collection. The tiny β′ (Mg2Si) strengthening precipitation phases mostly distribute in the grain boundary. The size of β′ strengthening phase is about 5nm. The width of no precipitation band is above of 50nm. The fatigue life is 1.061×105 cycle when σmax=0.75σb. The fatigue cracks initiate in surface of extruded Al-0.6Mg-0.6Si aluminium alloy sample. The fatigue fracture is composed of the initiation zone, the propagation zone, and the sudden fracture zone, which is characteristic of a mixed-type fatigue fracture

    Linkage Between SecA Dimerization and Ligand Binding

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    Abstract. Introduction and Objectives:. There have, yet, been only few attempts to phonetically characterize the vocalizations of pain, although there is wide agreement that moaning, groaning, or other nonverbal utterance can be indicative of pain. We studied the production of vowels “u,” “a,” “i”, and “schwa” (central vowel, sounding like a darker “e” as in hesitations like “ehm”)—as experimental approximations to natural vocalizations. Methods:. In 50 students vowel production and self-report ratings were assessed during painful and nonpainful heat stimulation (hot water immersion) as well as during baseline (no-stimulation). The phonetic parameters extracted were pitch (mean F0), phonatory fluctuations (range F0) and loudness (acoustic energy level). Results:. Only for the vowels “u” and “schwa,” which might be considered best approximations to moaning and groaning, did pitch and loudness increase during pain. Furthermore, changes from nonpainful to painful stimulations in these parameters also significantly predicted concurrent changes in pain ratings. Conclusion:. Vocalization characteristics of pain seem to be best described by an increase in pitch and in loudness. Future studies using more specific and comprehensive phonetic analyses will surely help to provide an even more precise characterization of vocalizations because of pain
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