Fine structure of the mouthparts of Diostrombus politus and Proutista moesta (Hemiptera: Derbidae)

Yin-Feng Meng,Dao-Zheng Qin 한국응용곤충학회 2018 Journal of Asia-Pacific Entomology Vol.21 No.3

Insect mouthparts are important sensory and feeding structures, morphological studies of this organ can provide additional data for phylogenetic studies. The planthopper superfamily Fulgoroidea is among the dominant groups of phytophagous insects, however, the mouthparts ultrastructure of this superfamily remains unsatisfactorily studied. This study investigates the ultrastructure of the mouthparts of two species in the family Derbidae (Hemiptera: Fulgoroidea), Diostrombus politus Uhler and Proutista moesta (Westwood), using a scanning electron microscope. The results show that these two derbids are of a typical piercing-sucking type found in Hemiptera. They consist of a cone-shaped labrum, a three-segmented labium and a stylet fascicle with two interlocked maxillary stylets incompletely wrapped by two mandibular stylets. The arrangement of the sensilla on the labial tip differ slightly between the two derbid species, and the subapical labial sensilla are likely different among genera in the family Derbidae.

Modeling and control strategy of flexible joint servo system in humanoid manipulator driven by tendon-sheath

Meng Yin,Dongyang Shang,Binhua Huang,Xinyu Wu,Wei Feng 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.5

The control effect of rotational speed in joints directly affects the motion accuracy of a humanoid manipulator driven by tendon-sheath. The dynamic parameters of the joint have time-varying characteristics due to the posture change of the manipulator. The joint driven by tendon-sheath has a specific torsional stiffness, so flexibility should be considered in the humanoid manipulator’s servo system. The time-varying of the parameters in the servo system and the joint flexibility can cause fluctuation of the output speed. To improve the motion accuracy of the humanoid manipulator, a fuzzy-tuned PI control strategy is used to suppress the instability of the output speed. First, the change law of the inertia on the motor side of the flexible joint is calculated by the dynamics equation of the humanoid manipulator. Next, a mathematical model of the joint is established, and the transfer function from the load speed to the electromagnetic torque is obtained. Furthermore, according to the pole-placement strategy, the fuzzy-tuned PI controller parameters are selected appropriately for the manipulator in different postures. Finally, the effectiveness of the proposed method is verified by numerical simulations and control experiments of the manipulator. The results show that the fuzzy-tuned PI control strategy can significantly reduce the tracking errors and improve the control performance of the manipulator.

Preparation and Characterization of PLA Film/3D Printing Composite Scaffold for Tissue Engineering Application

Chenjie Meng,Jiaming Zhao,Yuxiang Yin,Jun Luo,Lianying Zhao,Wenbin Jiang,Jianyong Feng 한국섬유공학회 2020 Fibers and polymers Vol.21 No.4

Three-dimensional (3D) printing technology provides an effective alternative for tissue engineering scaffold. Inthis paper, a composite scaffold composed of polylactic acid (PLA) film and 3D printing scaffold was fabricated which couldprovide structural and mechanical support for tissue application. The effects of PLA film/3D printing composite scaffold onscaffold morphology, average diameter, pore diameter, mechanical properties, themal conductivity, electrical conductivity,and surface hydrophilicity were characterized. PLA film/3D printing composite scaffold had larger thickness, bettermechanical and thermal conductivity properties in comparison with pure PLA film and 3D printed scaffold. These resultssuggested that composite scaffold with relatively good overall performance could be a potential candidate for tissueengineering application.

Power control of CiADS core with the intensity of the proton beam

Kai Yin,Wenjing Ma,Wenjuan Cui,Zhiyong He,Xinxin Li,Shiwu Dang,Feng Yang,Yuhui Guo,Limin Duan,Meng Li,Yikai Hou 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.4

This paper reports the control method for the core power of the China initiative Accelerator DrivenSystem (CiADS) facility. In the CiADS facility, an intense external neutron source provided by a protonaccelerator coupled to a spallation target is used to drive a sub-critical reactor. Without any control rodinside the sub-critical reactor, the core power is controlled by adjusting the proton beam intensity. Inorder to continuously change the beam intensity, an adjustable aperture is considered to be used at theLow Energy Beam Transport (LEBT) line of the accelerator. The aperture size is adjusted based on theProportional Integral Derivative (PID) controllers, by comparing either the setting beam intensity or thesetting core power with the measured value. To evaluate the proposed control method, a CiADS coremodel is built based on the point reactor kinetics model with six delayed neutron groups. The simulations based on the CiADS core model have indicated that the core power can be controlled stably byadjusting the aperture size. The response time in the adjustment of the core power depends mainly onthe adjustment time of the beam intensity

Isoindolin-1-ones from the stems of Nicotiana tabacum and their antiviral activities

Guang-Yu Yang,Jia-Meng Dai,Zhen-Jie Li,Jin Wang,Feng-Xian Yang,Xin Liu,Jing Li,Qian Gao,Xue-Mei Li,Yin-Ke Li,Wei-Guang Wang,Min Zhou,Qiu-Fen Hu 대한약학회 2022 Archives of Pharmacal Research Vol.45 No.8

In previous studies, several isoindolin-1-oneanalogs that exhibited signifi cant anti-tobacco mosaic virus(anti-TMV) activities were isolated from Nicotiana tabacum . Since gene-editing mutants provide a new sample for thediscovery of active metabolites, we focused on the stems ofYN-18–23 (a mutant N. tabacum for gene editing with thealkaloid metabolic pathway cultivated by Yunnan TobaccoCompany), which led to the isolation of four new ( 1–4 )and four known ( 5–8 ) isoindolin-1-ones. To the best of ourknowledge, nicindole C ( 3 ) is the fi rst subclass of isoindolin-1-one bearing a pentacyclic ketone, while nicindole D ( 4 )is the fi rst example of isoindolin-1-one bearing a methylpyridin-2-(1 H )-one moiety. Compounds 1–4 were testedfor their anti-TMV activities, and the results revealed thatcompounds 1 , 3 , and 4 exhibited high anti-TMV activities atconcentrations of 20 μM with inhibition rates of 48.6, 42.8,and 71.5%, respectively. These rates are higher than the inhibitionrate of the positive control (33.2%). The mechanisticstudy of compound 4 , which had the highest anti-TMV activityrevealed that increased potentiation of defense-related enzyme activities and downregulation of expression of theNtHsp70 protein may induce resistance in tobacco againstthe viral pathogen TMV. Molecular docking studies alsorevealed that the isoindolin-1-one substructure is fundamentalfor anti-TMV activity. The methyl-pyridin-2-(1 H )-onemoiety in compound 4 and the 2-oxopropyl groups in compounds1 and 3 at the N -2 position may increase inhibitoryactivities. This study of the structure–activity relationshipis helpful for fi nding new anti-TMV activity inhibitors. Tostudy whether the isoindolin-1-ones have broader antiviralactivities, compounds 1–4 were also tested for their antirotavirusactivities. Compound 4 exhibited high anti-rotavirusactivity with a therapeutic index (TI) value of 20.7. This TI value is close to that of the positive control (20.2).

Development of Origanum vulgare Cell Suspension Culture to Produce Polyphenols and the Stimulation Effect of Salicylic Acid Elicitation and Phenylalanine Feeding

Yan-Ping Li,Dao-Bang Tang,Xiao-Qiang Wang,Meng Wang,Qing-Feng Zhang,Yuan Liu,Bei-Yun Shen,Jiguang Chen,Zhongping Yin 한국생물공학회 2021 Biotechnology and Bioprocess Engineering Vol.26 No.3

Three types of calli were induced from Origanum vulgare (O. vulgare) aseptic seedlings, and the friable calli with white appearance and high growth rate were further screened and used to develop cell suspension culture to produce polyphenols. Murashige and Skoog (MS) medium with 3.0 mg/L Kinetin (KT) and 0.5 mg/L 2,4-dichlorophenoxy acetic acid (2,4-D) was suitable for both O. vulgare cells growth and polyphenols accumulation. To further enhance the polyphenols accumulation, O. vulgare cells were treated by phenylalanine (Phe) feeding and salicylic acid (SA) elicitation. Compared with the individual Phe feeding and SA elicitation, SA elicitation combined with Phe feeding showed a much better promotion effect on the polyphenols synthesis in O. vulgare cells, especially rosmarinic acid (RosA) accumulation. With the combined treatment of 200 μM SA and 100 μM Phe, total polyphenols content and yield were 41.36 mg/g and 752.93 mg/L, respectively. RosA content and yield reached 31.25 mg/g and 570.37 mg/L, which were 5.44 and 5.47 times that of the control. Furthermore, the total polyphenols extracted from the cultured cells treated by SA elicitation combined with Phe feeding displayed a much higher antioxidant capacity than that of untreated cells, meanwhile its 1,1-diphenyl-2- trinitrophenyl hydrazine (DPPH) and superoxide anion radical-scavenging activity were much stronger than that of vitamin C. What’s more, our results also showed that RosA was the principal contributor to the fine antioxidant capacity of the total polyphenols extracted from the SA and Phe treated cells. Our research indicated that SA elicitation combined with Phe feeding significantly improved the polyphenols yield and antioxidant capacity of the cultured O. vulgare cells, and therefore has a promising application prospect in natural polyphenols production.

A hemoglobin-based oxygen-carrying biomimetic nanosystem for enhanced chemo-phototherapy and hypoxia alleviation of hepatocellular carcinoma

Jing-Qing Le,Fang Yang,Xun-Huan Song,Ke-Ke Feng,Ling-Wu Tong,Meng-Die Yin,Wen-Zhong Zhang,Ying-Qi Lin,Hui Wu,Jing-Wei Shao 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.123 No.-

Tumor microenvironment is characterized by low pH, high reactive oxygen species and hypoxia, whichprovides a suitable environment for cancer growth. The hypoxia not only elevates tumor angiogenesisand metastasis, but also is responsible for the development of treatment resistance, which graduallybecomes a significant impediment for cancer therapy. Therefore, we developed a biomimetic nanosystemcontaining hemoglobin extracted from red blood cells, chemotherapy drug sorafenib, sensitizer ursolicacid and photosensitizer indocyanine green for enhanced chemo-photo combination therapy of hepatocellularcarcinoma, which could not only enhance the chemotherapy effect of sorafenib bowing to thesensitizing effect of ursolic acid, but also achieved synergetic phototherapy in virtue of indocyaninegreen. Besides, the nanoparticles could effectively delivery exogenous oxygen to tumor site and amelioratethe tumor hypoxic environment with the assistance of hemoglobin. The dual-sensitization drugdelivery system was expected to effectively reduce the resistance of traditional treatment methodsagainst tumor hypoxia, providing a novel prospect for the synergistic hepatocellular carcinomatreatment.