An improved stability criterion for linear time-varying delay systems

This paper considers the stability problem of linear systems with time-varying delays. A modified Lyapunov–Krasovskii functional (LKF) is constructed, which consists of delay-dependent matrices and double integral items under two time-varying subintervals. Based on the modified LKF, a less conservative stability criterion than some previous ones is derived. Furthermore, to obtain a tighter bound of the integral terms, the quadratic generalized free-weighting matrix inequality (QGFMI) is fully applied to different delay subintervals, which further reduces the conservatism of the stability criterion. Finally, three numerical examples are presented to show the effectiveness of the proposed approach

DGKZ Acts as a Potential Oncogene in Osteosarcoma Proliferation Through Its Possible Interaction With ERK1/2 and MYC Pathway

Osteosarcoma (OS) is one of the most common primary bone tumors in children and young adults. The majority of osteosarcoma patients have limited alternative therapeutic options and metastatic patients generally have a poor prognosis. Thus, it is important to explore novel effective therapeutic targets in the treatment of osteosarcoma. Diacylglycerol kinase zeta (DGKZ) is a recently identified gene potentially associated with certain human carcinogenesis. However, the role of DGKZ in proliferation of osteosarcoma is still unclear. In this study, DGKZ's expression was firstly investigated in OS tumor samples and correlated with poor outcome in OS patients. Silence of DGKZ by shRNA hampered osteosarcoma cell growth and promoted cell apoptosis in vitro. In vivo, DGKZ's knockout also suppressed xenograft tumor proliferation as determined by bioluminescence imaging and weight/volume measurements. Meanwhile, Affymetrix GeneChip and Ingenuity Pathway Analysis (IPA) revealed that DGKZ knockdown resulted in a decreased activity of MYC pathway, and several target genes expression in MYC pathway were altered, including CCND1, CDKN2B, CDK6, PCNA, and EGR1. Furthermore, immunoprecipitation coupled with mass spectrometry (IP-MS) analysis was used to identify proteins that interacted with DGKZ in OS cells and revealed ERK1/2, a key MYC-interactor, to associate with DGKZ. Together, our study demonstrated that DGKZ might act as an oncogene in osteosarcoma via its possible interaction with ERK1/2 and MYC pathway

Satisfaction with service coverage and drug list may influence patients’ acceptance of general practitioner contract service: a cross-sectional study in Guangdong, China

Abstract Background General practitioner (GP) system is proved to be effective in over 50 countries worldwide. Guangdong province, as a reform pilot in China, initiated its patient-GP contract service reform in 2014. This study is designed to assess the patients’ acceptance of General Practitioners Contract (GPC) reform and explore its influencing factors. Methods This survey interviewed 1010 participants from 16 primary health centers (PHCs) chosen from 4 pilot cities in Guangdong during July and December in 2015. Data were collected through face-to-face interviews. The questionnaire was developed to discover the acceptance of GPC and covered three parts: respondents’ socio-demographic characteristics, health service utilization, and the patients’ assessment of primary health care centers. A binary logistic regression model was used to measure the influencing factors of respondents’ acceptance of GPC policy. Results A total of 611(60.5%) participants accepted GPC policy. Compared to patients visited PHCs over 7 times in the previous year, those visited PHCs fewer times reported lower acceptance of GPC policy (OR:0.68, 95% CI:0.49–0.96 for visits ≤3 times and OR:0.57, 95% CI:0.38–0.84 for visits = 4–6 times). Patients’ satisfaction with medical service coverage was positively associated with patients’ acceptance of GPC (OR: 1.72, 95% CI:1.01–3.98 for the satisfied versus the dissatisfied; OR: 1.38, 95% CI:0.92–3.30 for neutral versus the dissatisfied), and the satisfaction with drug list also positively influenced patients’ acceptance of GPC policy (OR: 1.44, 95% CI:1.26–2.73 for the satisfied versus the dissatisfied; OR:1.61, 95% CI:1.36–2.99 for neutral versus the dissatisfied). Meanwhile, age and education had positive impacts on the acceptance of the GPC policy. Conclusion This study finds out that patients’ satisfaction with medical service coverage and drug list are the influencing factors for the acceptance of GPC policy. Therefore, improvement of medical service accessibility such as better follow-up of patients with chronic diseases and enhanced referral service, as well as the expansion of drug list, will improve patients’ acceptance of GPC policy. It also finds that patients using more primary health service are inclined to accept GPC policy, so more attractive and high-quality service should be provided in PHCs

Enhanced Stability Criteria of Network-Based Load Frequency Control of Power Systems with Time-Varying Delays

The stability problem for load frequency control (LFC) of power systems with two time-varying communication delays is studied in this paper. The one-area and two-area LFC systems are considered, respectively, which are modeled as corresponding linear systems with additive time-varying delays. An improved stability criterion is proposed via a modified Lyapunov-Krasovskii functional (LKF) approach. Firstly, an augmented LKF consisting of delay-dependent matrices and some single-integral items containing time-varying delay information in two different delay subintervals is constructed, which makes full use of the coupling information between the system states and time-varying delays. Secondly, the novel negative definite inequality equivalent transformation lemma is used to transform the nonlinear inequality to the linear matrix inequality (LMI) equivalently, which can be easily solved by the MATLAB LMI-Toolbox. Finally, some numerical examples are presented to show the improvement of the proposed approach

In-Situ Liquid Hydrogenation of m-Chloronitrobenzene over Fe-Modified Pt/Carbon Nanotubes Catalysts

In-situ liquid-phase hydrogenation of m-chloronitrobenzene (m-CNB) based on aqueous-phase reforming (APR) of ethanol and catalytic hydrogenation was carried out over Fe-modified Pt/carbon nanotubes (CNTs) catalysts. The effects of Pt loading over CNTs and Fe modification on the catalytic performance of Pt/CNTs catalysts were studied. In-tube loading of Pt particles, compared with out-tube loading, considerably improved the catalytic activity. With in-tube loading, Fe-modified Pt/CNTs catalysts further improved the m-CNB in-situ hydrogenation performance. After Fe modification, Pt–Fe/CNTs catalysts formed, inside CNTs, a Pt–Fe alloy and iron oxides, which both improved catalytic hydrogenation performance and significantly enhanced ethanol APR hydrogen producing performance, thereby increasing the m-CNB in-situ hydrogenation reactivity

Hydrogenation of Phenol over Pt/CNTs: The Effects of Pt Loading and Reaction Solvents

Carbon nanotubes (CNTs)-supported Pt nanoparticles were prepared with selective deposition of Pt nanoparticles inside and outside CNTs (Pt–in/CNTs and Pt–out/CNTs). The effects of Pt loading and reaction solvents on phenol hydrogenation were investigated. The Pt nanoparticles in Pt–in/CNTs versus Pt–out/CNTs are smaller and better dispersed. The catalytic activity and reuse stability toward phenol hydrogenation both improved markedly. The dichloromethane–water mixture as the reaction solvent, compared with either pure medium, decreased the catalytic activity toward phenol hydrogenation and selectivity of cyclohexanone over Pt–in/CNTs, but significantly improved the catalytic activity toward phenol hydrogenation and selectivity of cyclohexanone over Pt–out/CNTs

The Generation and Application of Monoclonal Antibodies to Detect SAPCD2 Expression in Precancerous and Malignant Gastric Lesions

Background: Suppressor APC domain containing 2 (SAPCD2) is involved in cell cycle regulation and its mRNA levels are higher in cancer tissues. But, the function of SAPCD2 in cancer development remains unclear.Objective: To generate mouse monoclonal antibodies (mAbs) specific to SAPCD2 and thus clarify the function of SAPCD2 in the development of gastric carcinoma (GC).Methods: Purified SAPCD2-GST immunized BALB/c mouse spleen cells were collected and fused with myeloma cells to obtain monoclonal antibody hybridoma. A group of monoclonal antibodies exhibiting high specificity and sensitivity against SAPCD2 has been generated and characterized by IHC, WB, IP, IF, and ELISA. By immunohistochemical analysis, the SAPCD2 expression was evaluated in 228 clinical samples of gastric mucosal lesions, including precancerous lesions and GC samples.Results: We identified a highly specific and sensitive clone of s12 in eukaryotic cells and performed an IHC analysis. We found that 81.3% of 107 GC tissues were SAPCD2-positive, compared with the 26.2% in the matched adjacent normal-appearing tissues (P<0.001). Furthermore, among the 121 gastritis tissues, SAPCD2 was overexpressed in precancerous gastric lesions such as dysplasia (Dys, 78.9%), intestinal metaplasia (IM, 44.7%), and chronic atrophic gastritis (CAG, 6.1%) compared with that in chronic non-atrophic gastritis (CNAG, 3.2%) (P<0.001). The SAPCD2-positivity rate was 81.3% in GC, suggesting that the expression of SAPCD2 increased with the severity of the lesion (P<0.001).Conclusion: In summary, we have described novel monoclonal antibodies against SAPCD2, which are highly expressed in GC tissues and may serve as the basis for an early clinical marker for GC development