Existence, multiplicity and uniqueness results for a second order m-point boundary value problem

Yuqiang Feng,Sanyang Liu 대한수학회 2004 대한수학회보 Vol.41 No.3

Let f:[0,1]times [0,infty)rightarrow [0,infty) be continuousand ain C([0,1],[0,infty)),and let xi_{i}in (0,1) with0<xi_{1} <xi_{2}<cdots<xi_{m-2}<1,a_{i}, b_{i}in [0,infty)with 0<sum_{i=1}^{m-2}a_{i}<1 andsum_{i=1}^{m-2}b_{i}<1.This paper is concerned with thefollowing m-point boundary value problem: x^{''}(t)+a(t)f(t,x(t))=0, tin (0,1),x^{'}(0)=sum_{i=1}^{m-2}b_{i}x^{'}(xi_{i}),x(1)=sum_{i=1}^{m-2}a_{i}x(xi_{i}) . The existence,multiplicity and uniqueness of positive solutions of this problemarediscussed with the help of two fixed point theorems in cones, respectively.

EXISTENCE, MULTIPLICITY AND UNIQUENESS RESULTS FOR A SECOND ORDER M-POINT BOUNDARY VALUE PROBLEM

Feng, Yuqiang,Liu, Sang-Yang Korean Mathematical Society 2004 대한수학회보 Vol.41 No.3

Let : [0, 1] $\times$ [0, $\infty$) $\longrightarrow$ [0, $\infty$) be continuous and a ${\in}$ C([0, 1], [0, $\infty$)),and let ${\xi}_{i}$ $\in$ (0, 1) with 0 < {\xi}$_1$ < ${\xi}_2$ < … < ${\xi}_{m-2}$ < 1, $a_{i}$, $b_{i}$ ${\in}$ [0, $\infty$) with 0 < $\Sigma_{i=1}$ /$^{m-2}$ $a_{i}$ < 1 and $\Sigma_{i=1}$$^{m-2}$ < l. This paper is concerned with the following m-point boundary value problem: $\chi$″(t)+a(t) (t.$\chi$(t))=0,t ${\in}$(0,1), $\chi$'(0)=$\Sigma_{i=1}$ $^{m-2}$ /$b_{i}$$\chi$'(${\xi}_{i}$),$\chi$(1)=$\Sigma_{i=1}$$^{m-2}$$a_{i}$$\chi$(${\xi}_{i}$). The existence, multiplicity and uniqueness of positive solutions of this problem are discussed with the help of two fixed point theorems in cones, respectively.

Bioactive Porous Biocomposites Coated Magnesium Alloy Implant for Bone Rejuvenation Using a Fracture in Rat Model

Peng Liu,Yuqiang Man,Yusong Bao 한국생물공학회 2021 Biotechnology and Bioprocess Engineering Vol.26 No.3

Bone fractures/defects are normal in more established individuals experiencing osteoporosis. In this work, we have explored osteoblast bond, multiplication, and separation on biocomposites of bioactive dual minerals substituted hydroxyapatite/alginate-chitosan/graphene oxide porous biocomposites coated magnesium alloy (AZ91 Mg alloy). Hydroxyapatite is one the most important mineral constituents for bony which, due to its bioactive and histocompatible properties, is commonly used as a material for hard tissue substitution. However, the use of apatite as hard tissue implants is restricted due to its fragile nature and reduced mechanical properties. To overcome this defect and to generate suitable bone implant material, dual minerals substituted hydroxyapatite (DM-HAP) is combined with biodegradable polymer alginate-chitosan (ALG-CS). Graphene oxide (GO) is integrated into the biocomposite, which has long been believed for soft and hard tissue implants owing to its excellent structural and mechanical properties, to enhance the mechanical properties of the biocomposite. Graphene oxide grounds are most important for the reconstruction of bone; new, outstanding DM-HAP/ ALG-CS/GO scaffold on Mg alloy has been developed. As developed coatings were characterized by X-ray diffraction (XRD) and scanning electron microscopy and energy dispersive X-ray analysis (SEM-EDX). Besides, the mechanical strength of the coating has also been assessed using adhesion and Vickers micro-hardness tests. In furtherer, the antibacterial activity of the composite was studied against Staphylococcus aureus and Escherichia coli and cell viability were observed in vitro against osteoblast cells and in vivo in rats. As a result, the results obtained propose that DM-HAP/ALG-CS/GO biocomposite can be believed as a prospective applicant for biomedical applications.

A Parallel PageRank Algorithm with Power Iteration Acceleration

Chun Liu,Yuqiang Li 보안공학연구지원센터 2015 International Journal of Grid and Distributed Comp Vol.8 No.2

Based on the study about the basic idea of PageRank algorithm, combining with the MapReduce distributed programming concepts, the paper first proposed a parallel PageRank algorithm based on adjacency list which is suitable for massive data processing. Then, after examining the essential characteristics of iteration hidden behind the PageRank, it provided an iteration acceleration model based on vector computing. Following, using such acceleration model, the paper again brought forward a parallel PageRank algorithm with power iteration acceleration with MapReduce. Finally, after abundant experimental analyses, it has been proved that the both the two proposed algorithm can be suitable for massive data processing and the 2nd one can significantly reduce the numbers of iteration and improve the efficiency of PageRank algorithm.

Study on the removal of chromium(III) from leather waste by a two-step method

Li Wang,Jun Liu,Yang Jin,Ming Chen,JianHong Luo,Xinhua Zhu,Yuqiang Zhang 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.79 No.-

The removal of chromium(III) from leather solid waste was carried out by two steps: the leaching stepand the ion exchange step. Orthogonal method was applied to the leaching process with H2SO4 asleaching agent and the leaching rate was nearly 100%. The adsorption and desorption of Cr3+ with 732#cation exchange resins were investigated in the ion exchange process. The effects of the resin types,temperature, rotating speed, liquid-solid ratio, initial Cr3+ concentration and time were investigated andthe optimum conditions were as follows: 732#, 333 K, 120 r/min, 20 ml/g, 280 ppm and 5 h. The removalefficiency of Cr3+ from leather hydrolysate was over 95% under optimized conditions. The desorptionefficiency of Cr3+ from loaded resins was almost 99% by three times cross-flow with Na2SO4 solution. There-adsorption of Cr3+ could achieve 95% by regenerated resins. The adsorption isotherms, kinetics andthermodynamics of Cr3+ onto 732# resins were investigated. The adsorption process appeared to followLangmuir isotherm model and the pseudo-second-order kinetic model. 4H0 = 33,816.03 kJ/mol and4S0 = 141.35 J/(mol K) were calculated. The two-step method was proved to be a sustainable andeconomic method for separating chromium from leather waste.

Research on the Landfill Dipole Leakage Detection and Its Influence Factors

( Lu Dong ),( Changxin Nai ),( Yuqiang Liu ),( Qi Wang ) 한국폐기물자원순환학회 2010 APLAS Vol.2010 No.0

Contrast-enhanced ultrasonography-based renal blood perfusion in brain-dead donors predicts early graft function

Weiming He,Yuguang Xu,Chaoyang Gong,Xiaozhen Liu,Yuqiang Wu,Xi Xie,Jiazhen Chen,Yi Yu,Zhiyong Guo,Qiang Sun 대한초음파의학회 2023 ULTRASONOGRAPHY Vol.42 No.4

Purpose: The aim of this study was to quantify renal microcirculatory perfusion in braindead donors using contrast-enhanced ultrasonography (CEUS), and to establish an accurate, noninvasive, and convenient index for predicting delayed graft function (DGF) post-transplantation. Methods: In total, 90 brain-dead donor kidneys (training group, n=60; validation group, n=30) examined between August 2020 and November 2022 were recruited in this prospective study. CEUS was performed on the kidneys of brain-dead donors 24 hours before organ procurement and time-intensity curves were constructed. The main measures were arrival time, time to peak, and peak intensity of the kidney segmental arteries, cortex, and medulla. Recipients were divided into DGF and non-DGF groups according to early post-transplant graft function. The area under the receiver operating characteristic curve (AUC) was used to assess diagnostic performance. Results: The arrival time of the kidney segmental artery and cortex and the time interval between the time to peak of the segmental artery and cortex were identified as independent factors associated with DGF by multivariate stepwise regression analysis. A new index for the joint prediction model of three variables, the contrast-enhanced ultrasonography/Kidney Donor Profile index (CEUS-KDPI), was developed. CEUS-KDPI showed high accuracy for predicting DGF (training group: AUC, 0.91; sensitivity, 90.5%; specificity, 92.3%; validation group: AUC, 0.84; sensitivity, 75.0%; specificity, 92.3%). Conclusion: CEUS-KDPI accurately predicted DGF after kidney transplantation. CEUS may be a potential noninvasive tool for bedside examinations before organ procurement and may be used to predict early renal function after kidney transplants kidneys from donors after brain death.

Diagnostic value of alcoholic liver disease (ALD)/nonalcoholic fatty liver disease (NAFLD) index combined with γ-glutamyl transferase in differentiating ALD and NAFLD

( Junling Wang ),( Ping Li ),( Zhilong Jiang ),( Qiuhui Yang ),( Yuqiang Mi ),( Yonggang Liu ),( Ruifang Shi ),( Yonghe Zhou ),( Jinsheng Wang ),( Wei Lu ),( Si Li ),( Dan Liu ) 대한내과학회 2016 The Korean Journal of Internal Medicine Vol.31 No.3

Background/Aims: This study aimed to verify the reliability of the alcoholic liver disease (ALD)/nonalcoholic fatty liver disease (NAFLD) index (ANI) for distinguishing ALD in patients with hepatic steatosis from NAFLD, and to investigate whether ANI combined with γ-glutamyl transferase (GGT) would enhance the accuracy of diagnosis in China. Methods: A hundred thirty-nine cases of fatty liver disease (FLD) were divided into two groups of ALD and NAFLD. The ANI was calculated with an online calculator. All indicators and ANI values were analyzed using statistical methods. Results: ANI was significantly higher in patients with ALD than in those with NAFLD (7.11 ± 5.77 vs. .3.09 ± 3.89, p < 0.001). With a cut-off value of .0.22, the sensitivity, specificity, and area under the receiver operating characteristic curve (AUROC) of diagnosed ALD cases was 87.1%, 92.5%, and 0.934 (95% confidence interval [CI], 0.879 to 0.969), respectively. The corresponding values for aspartate aminotransferase (AST)/alanine transaminase (ALT), mean corpuscular volume (MCV), and GGT were 75.29%, 72.94%, and 0.826 (95% CI, 0.752 to 0.885); 94.34%, 83.02%, and 0.814 (95% CI, 0.739 to 0.875) and 80.23%, 79.25%, and 0.815 (95% CI, 0.740 to 0.876), respectively. ANI AUROC was significantly higher than the AST/ ALT, MCV, or GGT AUROCs (all p < 0.001), moreover, ANI showed better diagnostic performance. The combination of ANI and GGT showed a better AUROC than ANI alone (0.976 vs. 0.934, p = 0.016). The difference in AUROCs between AST/ALT, MCV, and GGT was not statistically significant (all p > 0.05). Conclusions: ANI can help distinguish ALD from NAFLD with high accuracy; when ANI was combined with GGT, its effectiveness improved further.

Role of Dehydrocorybulbine in Neuropathic Pain After Spinal Cord Injury Mediated by P2X4 Receptor

Wang, Zhongwei,Mei, Wei,Wang, Qingde,Guo, Rundong,Liu, Peilin,Wang, Yuqiang,Zhang, Zijuan,Wang, Limin Korean Society for Molecular and Cellular Biology 2019 Molecules and cells Vol.42 No.2

Chronic neuropathic pain is one of the primary causes of disability subsequent to spinal cord injury. Patients experiencing neuropathic pain after spinal cord injury suffer from poor quality of life, so complementary therapy is seriously needed. Dehydrocorybulbine is an alkaloid extracted from Corydalis yanhusuo. It effectively alleviates neuropathic pain. In the present study, we explored the effect of dehydrocorybulbine on neuropathic pain after spinal cord injury and delineated its possible mechanism. Experiments were performed in rats to evaluate the contribution of dehydrocorybulbine to P2X4 signaling in the modulation of pain-related behaviors and the levels of pronociceptive interleukins and proteins after spinal cord injury. In a rat contusion injury model, we confirmed that chronic neuropathic pain is present on day 7 after spinal cord injury and P2X4R expression is exacerbated after spinal cord injury. We also found that administration of dehydrocorybulbine by tail vein injection relieved pain behaviors in rat contusion injury models without affecting motor functions. The elevation in the levels of pronociceptive interleukins ($IL-1{\beta}$, IL-18, MMP-9) after spinal cord injury was mitigated by dehydrocorybulbine. Dehydrocorybulbine significantly mitigated the upregulation of P2X4 receptor and reduced ATP-evoked intracellular $Ca^{2+}$ concentration. Both P2XR and dopamine receptor2 agonists antagonized dehydrocorybulbine's antinociceptive effects. In conclusion, we propose that dehydrocorybulbine produces antinociceptive effects in spinal cord injury models by inhibiting P2X4R.

Molecular genetic characterization of rice seed lipoxygenase 3 and assessment of its effects on seed longevity

Qizhang Long,Wenwei Zhang,Peng Wang,Wenbiao Shen,Tong Zhou,Nannan Liu,Ren Wang,Ling Jiang,Jiexue Huang,Yihua Wang,Yuqiang Liu,Jianmin Wan 한국식물학회 2013 Journal of Plant Biology Vol.56 No.4

Lipoxygenases (LOXs) are enzymes involved in lipid peroxidation. Here we reported the identification, molecular and functional characterization of the gene encoding rice (Oryza sativa L.) seed LOX3 (sLOX3). Via a map-based cloning strategy we identified Os03g0700400 as the candidate gene encoding sLOX3. Further functional complementary test and biochemical characterization of the recombinant Os03g0700400 protein verified the identification. The sLOX3 gene was highly expressed in roots, moderately in embryos and very weakly in leaves, leaf sheaths and stems. Transient expression experiment (in rice protoplasts) and subsequent laser confocal microscopic analysis demonstrated that the sLOX3 protein was localized into the cytosol. We next showed that overexpression of sLOX3 in a japonica sLOX3-normal rice cultivar, Wuyunjing 7 accelerated the decrease of seed germination ability when the seeds were routinely stored, which demonstrated that sLOX3 had a negative effect on seed longevity (storability). Meanwhile, an increased occurrence of embryo decay was observed in the same transgenic seeds, suggesting that sLOX3 might negatively affect seed longevity by facilitating colonization of particular seed pathogens. Our result forwarded the understanding of the effects of 9-LOX on rice seed longevity.