Study of a Rapid Detection Method for Protein Content in Milk and Development of Detection Equipment

Liu Zhongfu,Chen Xingwen,Shi Lixin 보안공학연구지원센터 2015 International Journal of Multimedia and Ubiquitous Vol.10 No.12

Among the nutrients in milk, protein content is a core indicator for measuring the quality of milk. Therefore, to explore a rapid detection method for milk protein content and develop rapid detection equipment for protein ingredient can provide reference for quality analysis and quality control of the production process. In this paper, different dairy protein detection methods are analyzed, the working principles of Micro-Kjeldahl method are studied, and a new type of milk protein content detector is designed based on the Micro-Kjeldahl nitrogen determination method. As for this instrument, LPC2214 microcontroller with ARM structure is taken as the control core, with the functions such as adding certain volume of lye, adding certain volume of boric acid absorption liquid, automatically generating steam required, automatically titrating hydrochloric acid solution, accurately determining the endpoint, conveniently setting parameters and so on, which realizes the digital and intelligent design in determining the protein content in dairy products. Experimental results show that the system is stable, with broad application prospects.

Fixed Time Event-triggered Tracking Control for Interconnected Nonlinear Uncertain Systems: An Observer-based Approach

Panpan Yang,Xingwen Chen,Xiangmo Zhao,Maode Yan 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.8

The fixed time event-triggered tracking control for interconnected nonlinear uncertain systems, whose state variables are unmeasurable, is investigated via an observer-based approach. The unmeasurable states are estimated by the designed neural observer under the fixed time stability criterion, and the uncertain interconnections are compensated by a smooth function. Then, a novel tracking error-based event-triggered strategy is employed to reduce the communication frequency of the control signal. By means of radial basis function (RBF) neural networks (NNs) to approximate the unknown nonlinearities, a fixed time event-triggered controller is designed to guarantee the convergence of tracking error to the origin in a fixed time. Finally, the proposed technique is verified by some numerical simulations.

Fabrication of nonlinear optical films based on methacrylate/silica hybrid matrix

Di Wang,Xiaodong Chen,Xingwen Zhang,Wunjun Wang,Yunlong Liu,Lijiang Hua 한국물리학회 2009 Current Applied Physics Vol.9 No.3

A free-radical polymerization was performed to fabricate nonlinear optical (NLO) hybrid films based on nanostructural building blocks and an interpenetrating methacrylate/silica hybrid matrix (IHM). A bulky chromophore (disperse orange 3) bonded with ally glycidyl ether (AGE) was incorporated into the hybrid matrix in combination with (γ-methacrylpropyl)-silsesquioxane through the polymerization. Different amounts of polyhedral oligomeric silsesquioxane as modifiers were added into the IHM to enhance properties. It has been shown that the IHM increases the crosslink density of the network and the interaction potential between dipoles to help maintain the orientational order, and the generated NLO materials enhance the Tg, nonresonant second-order nonlinearity and temporal stability. A free-radical polymerization was performed to fabricate nonlinear optical (NLO) hybrid films based on nanostructural building blocks and an interpenetrating methacrylate/silica hybrid matrix (IHM). A bulky chromophore (disperse orange 3) bonded with ally glycidyl ether (AGE) was incorporated into the hybrid matrix in combination with (γ-methacrylpropyl)-silsesquioxane through the polymerization. Different amounts of polyhedral oligomeric silsesquioxane as modifiers were added into the IHM to enhance properties. It has been shown that the IHM increases the crosslink density of the network and the interaction potential between dipoles to help maintain the orientational order, and the generated NLO materials enhance the Tg, nonresonant second-order nonlinearity and temporal stability.

Quantitative Reduction of Basilar Invagination With Atlantoaxial Dislocation by a Posterior Approach

Jian Guan,Fengzeng Jian,Qingyu Yao,Chenghua Yuan,Can Zhang,Longbing Ma,Zhenlei Liu,Wanru Duan,Xingwen Wang,Xuefeng Bo,Zan Chen 대한척추신경외과학회 2020 Neurospine Vol.17 No.3

Objective: This study evaluated the feasibility and efficacy of quantitative reduction and fixation to treat basilar invagination (BI) with atlantoaxial dislocation (AAD). Methods: Posterior occipitocervical angle (POCA), occiput–C2 angle (Oc–C2A), clivusaxial angle (CAA), and C2–7 angle (C2–7A) were considered for quantitative reduction. Twelve patients with BI complicated with AAD received posterior interarticular release and individualized cage implantation to restore vertical dislocation. The POCA was adjusted using cantilever technology to further reduce the horizontal dislocation and adjust lower cervical vertebral angle. All patients received a radiological follow-up for ≥12 months. Improvements in spinal cord function were evaluated using Japanese Orthopedic Association (JOA) score. Results: All the patients received successful quantitative reduction for BI-AAD, and bony fusion was achieved without spinal cord injury after surgery for 12 months. The JOA score was improved significantly to 15.2 ± 0.9 twelve months after surgery (p < 0.01). Radiological follow-up revealed that individualized cage and POCA play vital roles in quantitative correction: (1) distance of the dens above McRae’s line and atlantodens interval were restored to normal level, respectively; (2) changes in Oc–C2 angle (ΔOc–C2A), C2–7 angle (ΔC2–7A), clivus-axial angle (ΔCAA), and POCA (ΔPOCA) were all caused by changes in axis tilt. Based on the changes of radiological parameter we deduced the formula for quantitative reduction by linear regression analysis: -ΔPOCA = ΔOc–C2A = -ΔC2–7A = ΔCAA. Conclusion: Quantitative posterior reduction by individualized cage and adjusting ΔPOCA is feasible for treating BI with AAD.

Role of Preoperative Albumin Quotient in Surgical Planning for Posttraumatic Syringomyelia: A Comparative Cohort Study

Pingchuan Xia,Houyuan Lv,Chenghua Yuan,Wanru Duan,Jiachen Wang,Jian Guan,Yueqi Du,Can Zhang,Zhenlei Liu,Kai Wang,Zuowei Wang,Xingwen Wang,Hao Wu,Zan Chen,Fengzeng Jian 대한척추신경외과학회 2024 Neurospine Vol.21 No.1

Objective: Surgical procedures for patients with posttraumatic syringomyelia (PTS) remain controversial. Until now, there have been no effective quantitative evaluation methods to assist in selecting appropriate surgical plans before surgery. Methods: We consecutively enrolled PTS patients (arachnoid lysis group, n = 42; shunting group, n = 14) from 2003 to 2023. Additionally, 19 intrathecal anesthesia patients were included in the control group. All patients with PTS underwent physical and neurological examinations and spinal magnetic resonance imaging preoperatively, 3–12 months postoperatively and during the last follow-up. Preoperative lumbar puncture was performed and blood-spinal cord barrier disruption was detected by quotient of albumin (Qalb, cerebrospinal fluid/serum). Results: The ages (p = 0.324) and sex (p = 0.065) of the PTS and control groups did not differ significantly. There were also no significant differences in age (p = 0.216), routine blood data and prognosis (p = 0.399) between the arachnoid lysis and shunting groups. But the QAlb level of PTS patients was significantly higher than that of the control group (p < 0.001), and the shunting group had a significantly higher QAlb (p < 0.001) than the arachnoid lysis group. A high preoperative QAlb (odds ratio, 1.091; 95% confidence interval, 1.004–1.187; p = 0.041) was identified as the predictive factor for the shunting procedure, with the receiver operating characteristic curve showing 100% specificity and 80.95% sensitivity for patients with a QAlb > 12.67. Conclusion: Preoperative QAlb is a significant predictive factor for the types of surgery. For PTS patients with a QAlb > 12.67, shunting represents the final recourse, necessitating the exploration and development of novel treatments for these patients.