823 results on '"Qin, CHEN"'
Search Results
2. Rapid Detection of Nonprotein Nitrogen Adulterants in Milk Powder Using Point-Scan Raman Hyperspectral Imaging Technology
- Author
-
Qiaoling Yang, Bing Niu, Shuqing Gu, Jinge Ma, Chaomin Zhao, Qin Chen, Dehua Guo, Xiaojun Deng, Yongai Yu, and Feng Zhang
- Subjects
Chemistry ,QD1-999 - Published
- 2022
- Full Text
- View/download PDF
3. New Pyridine-Bridged Ferrocene–Rhodamine Receptor for the Multifeature Detection of Hg2+ in Water and Living Cells
- Author
-
Yu-Shuang Guo, Mei Zhao, Qiong Wang, Yu-Qin Chen, and Dian-Shun Guo
- Subjects
Chemistry ,QD1-999 - Published
- 2020
- Full Text
- View/download PDF
4. Facile Synthesis of Calcite-Impregnated Hydrochar with High Sorption Capacity for Cu(II) from Aqueous Solution
- Author
-
Xiao-qin Chen, Bing Li, Yang Shen, and Jian-Zhong Guo
- Subjects
Chemistry ,QD1-999 - Published
- 2019
- Full Text
- View/download PDF
5. Cyclometalated Iridium(III) Complexes Containing 2-Phenylbenzo[d]oxazole Ligand: Synthesis, X-ray Crystal Structures, Properties and DFT Calculations
- Author
-
Xiao-Han Yang, Qian Zhang, Hui Peng, Zi-Cen Zuo, Ding Yuan, Yan Chen, Qin Chen, Guang-Ying Chen, Zhi-Gang Niu, and Gao-Nan Li
- Subjects
Iridium(III) complex ,Crystal structure ,2-phenylbenzo[d]oxazole ,Photoluminescence ,DFT calculation ,Chemistry ,QD1-999 - Abstract
Two new iridium(III) complexes were synthesized and fully characterized, [(bo)2Ir(pzpy)] (2a) and [(bo)2Ir(pzpyz)] (2b) (where bo = 2-phenylbenzo[d]oxazole, pzpy = 2-(1H-pyrazol-3-yl)pyridine, pzpyz = 2-(1H-pyrazol-3-yl)pyrazine). The single crystal structures of 2a-2b have been determined. Considering the relationship between their structures and photophysical properties, DFT calculations have been used to further support this inference. These Ir(III) complexes emit from the excited state of 3MLCT/3LLCT in the green and yellow region, and the quantum yields in the degassed CH2Cl2 solution at room temperature are 35.2% and 46.1%. Theoretical and experimental results show that iridium(III) complexes 2a-2b are promising phosphorescent material.
- Published
- 2019
- Full Text
- View/download PDF
6. Editorial: Superwetting Interfaces for Oil/Water Separation
- Author
-
Jiuyang Lin, Qin Chen, Moyuan Cao, Jingwei Hou, and Wenyuan Ye
- Subjects
oil spill ,industrial oily wastewater ,superhydrophilicity ,superhydrophobicity ,oil/water separation ,Chemistry ,QD1-999 - Published
- 2021
- Full Text
- View/download PDF
7. Elevated Levels of Oxidative Nucleic Acid Modification Markers in Urine From Gastric Cancer Patients: Quantitative Analysis by Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry
- Author
-
Qin Chen, Yiqiu Hu, Zhihao Fang, Minfeng Ye, Jingqing Li, Suzhan Zhang, Ying Yuan, and Cheng Guo
- Subjects
UPLC-MS/MS ,nucleic acid modification ,oxidative stress ,gastric cancer ,biomarker ,urine ,Chemistry ,QD1-999 - Abstract
Oxidative nucleic acid modifications have attracted increasing attention in recent years since they have been found to be related to a number of diseases including cancer. 8-Hydroxy-2′-deoxyguanosine (8-OHdG) and 8-hydroxyguanosine (8-OHG) are the typical markers of oxidative modification of DNA and RNA, respectively, and they are emerging biomarkers for the early detection of diseases. Urine is a favored biofluid for biomarker discovery due to its noninvasiveness to patients. Accurate quantification of these oxidative nucleic acid modifications still has challenges because their amounts in urine are very low and the interferences in urine samples are complicated. Herein, we developed and validated an accurate and robust solid-phase extraction (SPE) coupled with ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the simultaneous quantification of these oxidative nucleic acid modifications in human urine. Stable isotope dilution strategy was utilized and the method shows good precision on intraday and interday measurements. Meanwhile, recovery was satisfactory by utilizing the Oasis hydrophilic–lipophilic balance (HLB) cartridge for sample pretreatment at three spiked levels. We successfully quantified urinary 8-OHdG and 8-OHG from 60 gastric cancer patients and 70 healthy controls by using this method. The measured contents of 8-OHdG and 8-OHG in urine from gastric cancer patients are both increased, compared with those in urine from healthy controls, indicating these oxidative nucleic acid modifications could act as potential non-invasive markers for early diagnosis of gastric cancer. Moreover, the present study will stimulate investigations of the effects of oxidative stress and nucleic acid modifications on the initiation and progression of gastric cancer.
- Published
- 2020
- Full Text
- View/download PDF
8. Low-Cost RSAC and Adsorption Characteristics in the Removal of Copper Ions from Wastewater
- Author
-
Yan Liu, Qin Chen, and Rajendra Prasad Singh
- Subjects
water pollution ,adsorption ,copper ions ,adsorption mechanism ,adsorption kinetics ,thermodynamics ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
Adsorption is a typical method for treating copper-containing wastewater. Fly ash and steel slag both have a good adsorption performance, and activated clay is added in this study, too. In this study, the performance of residue and soil adsorption composite (RSAC) particles for copper ion adsorption was discussed through the substrate ratio and the influence mechanism, to achieve the win–win effect of industrial waste reuse and copper ion wastewater treatment. The results indicated that adsorption time, dosage, initial copper ion concentration, coexisting ions, and temperature showed different effects on the adsorption, respectively. Additionally, the adsorption kinetic study showed the removal of copper ions by adsorption of RSAC particles was in accordance with quasi-primary kinetic model and quasi-secondary kinetic model. The adsorption thermodynamics study shows the adsorption process of ΔG0 < 0, ΔH0 > 0 and ΔS0 > 0, indicating that the process of copper ion adsorption by RSAC particles was spontaneous, heat-absorbing, and entropy-increasing. The research demonstrates that RSAC particles have a certain adsorption capacity for copper ion.
- Published
- 2022
- Full Text
- View/download PDF
9. Evaluation of internal fixation techniques for condylar head fractures: A finite element analysis and comparison
- Author
-
Jisi Zheng, Kai Huang, Chi Yang, Lingtong Bu, Qin Chen, Ya-ting Qiu, and Xiaowen Zhao
- Subjects
musculoskeletal diseases ,medicine.medical_treatment ,Finite Element Analysis ,chemistry.chemical_element ,Bone and Bones ,Condyle ,Pathology and Forensic Medicine ,Stress (mechanics) ,Fracture Fixation, Internal ,Fixation (surgical) ,Humans ,Medicine ,Internal fixation ,Radiology, Nuclear Medicine and imaging ,Dentistry (miscellaneous) ,Displacement (orthopedic surgery) ,Titanium ,Orthodontics ,business.industry ,musculoskeletal system ,equipment and supplies ,Finite element method ,Biomechanical Phenomena ,surgical procedures, operative ,chemistry ,Head (vessel) ,Surgery ,Oral Surgery ,business ,Bone Plates - Abstract
Objectives This study evaluated optimum stability of different screw techniques for condylar head fractures (CHF) (P close to an M fracture with the lateral pole preserved according to AO classification 2014) by finite element analysis (FEA) and provided a biomechanical basis for clinical treatment. Study Design Four CHF fixation models were evaluated: (A) single bicortical screw, (B) 2 bicortical screws, (C) 1 bicortical screw and 1 monocortical screw (used as a positional screw) inserted via a 2-hole titanium plate, and (D) 2 bicortical screws inserted via a titanium plate. Stresses were calculated (FEA) to measure mechanical properties. Results The displacement for A and C was larger than for B and D. The maximum stress on the screws for A and C exceeded their breaking limit but was safe for B and D. The stress on the titanium plate for C and D was safe. The stress on bone for A and C was larger than for B and D. Conclusions The 2 bicortical screw fixation reduced the stress on implanted materials and surrounding bone tissue. Titanium plates further alleviated the lever action. Two bicortical screw fixation was more reliable for CHF, and early postoperative loading and functional training can be expected.
- Published
- 2022
- Full Text
- View/download PDF
10. Pure photosensitizer-driven nanoassembly with core-matched PEGylation for imaging-guided photodynamic therapy
- Author
-
Cong Luo, Bingjun Sun, Zhiqiang Kong, Xuanbo Zhang, Yuequan Wang, Jin Sun, Zhonggui He, Qin Chen, Shenwu Zhang, and Han Yu
- Subjects
SDS, sodium dodecyl sulfate ,CRE, creatinine ,medicine.medical_treatment ,PS, photosensitizer ,nano-DDS, nanoparticulate drug delivery systems ,Nanoparticle ,Photodynamic therapy ,AST, aspartate aminotransferase ,RM1-950 ,Pyropheophorbide a ,Imaging-guided ,Systemic circulation ,Nanoassembly ,Hydrophobic effect ,03 medical and health sciences ,NaCl, sodium chloride ,ROS, reactive oxygen species ,Pure photosensitizer ,0302 clinical medicine ,FBS, fetal bovine serum ,ALT, alanine aminotransferase ,Amphiphile ,PEG ratio ,medicine ,DCFH-DA, 2′,7′-dichlorofluorescein diacetate ,Photosensitizer ,General Pharmacology, Toxicology and Pharmaceutics ,SOSG, Singlet Oxygen Sensor Green Reagent ,NPs, nanoparticles ,030304 developmental biology ,0303 health sciences ,Chemistry ,DDS, drug delivery system ,PDANs, pure drug-assembled nanomedicines ,Self-assembly ,respiratory system ,ACQ, aggregation caused quenching ,BUN, blood urine nitrogen ,PDT, photodynamic therapy ,PBS, phosphate buffer solution ,Pure drug-assembled nanomedicines ,030220 oncology & carcinogenesis ,PEGylation ,Biophysics ,Original Article ,PPa, pyropheophorbide a ,Therapeutics. Pharmacology ,Core-matched - Abstract
Pure drug-assembled nanomedicines (PDANs) are currently under intensive investigation as promising nanoplatforms for cancer therapy. However, poor colloidal stability and less tumor-homing ability remain critical unresolved problems that impede their clinical translation. Herein, we report a core-matched nanoassembly of pyropheophorbide a (PPa) for photodynamic therapy (PDT). Pure PPa molecules are found to self-assemble into nanoparticles (NPs), and an amphiphilic PEG polymer (PPa-PEG2K) is utilized to achieve core-matched PEGylating modification via the π‒π stacking effect and hydrophobic interaction between the PPa core and the PPa-PEG2K shell. Compared to PCL-PEG2K with similar molecular weight, PPa-PEG2K significantly increases the stability, prolongs the systemic circulation and improves the tumor-homing ability and ROS generation efficiency of PPa-nanoassembly. As a result, PPa/PPa-PEG2K NPs exert potent antitumor activity in a 4T1 breast tumor-bearing BALB/c mouse xenograft model. Together, such a core-matched nanoassembly of pure photosensitizer provides a new strategy for the development of imaging-guided theragnostic nanomedicines., Graphical abstract Pyropheophorbide a (PPa)-driven nanoassembly was formed by the core-matched modification of PPa-PEG2K. Afterwards, PPa/PPa-PEG2K NPs are endocytosed by tumor cells to exert effective photodynamic under laser irradiation.Image 1
- Published
- 2021
- Full Text
- View/download PDF
11. Simultaneous removal of NO, SO2 and Hg0 with the WDRMRS
- Author
-
Qin Chen, Qiaoling Zhu, Sicheng Wu, Mingqiang Deng, Dengxin Li, and Zhengguo Xiao
- Subjects
Pollutant ,Reaction mechanism ,Flue gas ,Radical ,General Medicine ,Pulp and paper industry ,chemistry.chemical_compound ,chemistry ,Urea ,Environmental Chemistry ,Absorption (chemistry) ,Dispersion (chemistry) ,Waste Management and Disposal ,NOx ,Water Science and Technology - Abstract
Micro-nanobubbles can spontaneously generate hydroxyl free radicals (OH). Urea is a cheap reductant and can react with NOx species, and their products are nontoxic and harmless N2, CO2 and H2O. In this study, a Wet Direct Recycling Micro-nanobubble Flue Gas Multi-pollutants Removal System (WDRMRS) was developed for the simultaneous removal of NO, SO2 and Hg0. In this system, a micro-nanobubble generator (MNBG) was used to produce a micro-nanobubble gas-liquid dispersion system (MNBGLS) through recycling the urea solution from the reactor and the simulated flue gas composed of N2, NO, SO2 and Hg0. The MNBGLS, which has a large gas-liquid dispersion interface, was recycled continuously from the MNBG to the reactor, thus achieving cyclic absorption of various pollutants. All of the investigated parameters, including the initial pH and temperature of the absorbent as well as the concentrations of urea, NO and SO2 had significant effects on the NO removal efficiency but did not significantly affect the SO2 removal efficiency, whereas only the initial solution pH and NO concentration affected the Hg0 removal efficiency. The analysis results of the reaction mechanism showed that ·OH played a critical role in the removal of various pollutants. After the treatment by this system, the main removal products were Hg0 sediment, SO42- and NH4+ which could be easily recycled. The use of this system (MNBGLS) for the simultaneous removal of NO, SO2 and Hg0 is a new technology application and research. Recycling process based on MNBGLS succeeded in simultaneously removing NO, SO2 and Hg0. The system (MNBGLS) can provide a reference for commercial applications. The removal products are relatively simple and beneficial to recycling, which can reduce the cost of waste gas treatment.
- Published
- 2021
- Full Text
- View/download PDF
12. Standard litterbags underestimate early-stage lower-order root decomposition rate in a subtropical forest, China
- Author
-
Yi Tang, Gang Chen, Yin-long Xiao, Guan-tao Chen, Jiulong Xie, Yong Peng, Li-hua Tu, Li Liu, Yu-qin Chen, and Hongling Hu
- Subjects
Cleyera japonica ,biology ,Chemistry ,Soil Science ,Lower order ,Plant Science ,biology.organism_classification ,Decomposition ,Humus ,Nutrient ,Agronomy ,Litter ,Soil horizon ,Tropical and subtropical moist broadleaf forests - Abstract
The standard litterbag method isolates soil or litter from decomposing roots by a dense nylon mesh that is likely to underestimate root decomposition rate. Thus, we evaluated the effect of direct contact between roots and soil or litter during root decomposition. Schima superba and Cleyera japonica order 1–3, 4–5, and 6 roots were decomposed using two types of litterbags at two soil horizons: standard litterbags (R_O, pure root in O horizon; R_A, pure root in A horizon) and mixed litterbags (R + L_O, mixed root with semi-decomposed litter in O horizon; and R + HS_A, mixed root with humus soil in A horizon). The mass and nutrient dynamics were measured in one year of decomposition. After one year of decomposition, litterbag types and soil horizons significantly affected root mass and nutrient dynamics. Litterbags mixed with humus soil and litter increased 1–3 order root decomposition rate by 139–143% and 42–89%, respectively. Furthermore, 1–3 order roots had a significantly different decomposition rate than higher-order roots, but standard and mixed litterbags showed the opposite effect. The decomposition rate of 1–3 order roots appears to be more sensitive to litterbag type than higher-order roots. Directly contact between root and soil or litter was important for root decomposition in corresponding soil layers. Standard litterbags significantly underestimate the decomposition rate of lower-order roots in the early stages of decomposition.
- Published
- 2021
- Full Text
- View/download PDF
13. Altered Carcinoembryonic Antigen-Related Cell Adhesion Molecule 1/T-Cell Immunoglobulin Mucin-3 Signaling Causes the Dysregulation of Decidual CD8+T Cells in the Third Trimester during Preeclamptic Pregnancies
- Author
-
Mei-Rong Du, Feng-Run Sun, Songcun Wang, Ying Zhang, Chun-Qin Chen, and Meng-Die Li
- Subjects
3rd-trimester ,carcinoembryonic antigen-related cell adhesion molecule 1 ,cd8+t cells ,preeclampsia ,tim-3 ,biology ,Cell adhesion molecule ,T Cell Immunoglobulin Mucin-3 ,Chemistry ,Obstetrics and Gynecology ,RC581-607 ,RC648-665 ,Third trimester ,Molecular biology ,Diseases of the endocrine glands. Clinical endocrinology ,Carcinoembryonic antigen ,Reproductive Medicine ,biology.protein ,Cytotoxic T cell ,Immunologic diseases. Allergy - Abstract
Objective: To investigate the frequency and function of Tim-3+CD8+T cells in the third trimester of normal pregnancies (NPs) and preeclamptic (PE) pregnancies. Methods: T-cell immunoglobulin mucin-3 (Tim-3) expression levels of CD8+T cells in the decidua, peripheral blood, and umbilical cord blood obtained from women showing NPs and PE pregnancies were analyzed using flow cytometry. Decidual CD8+T cells were cultured in the presence of recombinant human carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) protein and/or Tim-3-specific neutralizing antibodies for analyzing CD107a and intracellular cytokine expression. The placental CEACAM1 protein expression was analyzed using immunohistochemistry. Results: Tim-3+CD8+T cells were more abundant in the decidua than in the peripheral blood. Tim-3 expression in the decidual CD8+T cells was significantly lower in PE patients. Decidual Tim-3+CD8+T cells from PE patients expressed higher levels of CD107a and the Th1-type cytokine IFN-γ, but lower levels of the Th2-type cytokine IL-4. CEACAM1 altered the CD107a, IFN-γ, and IL-4 levels; this was reversed by anti-Tim-3 antibodies. The CEACAM1 protein levels were lower in the placental tissues of women with PE pregnancies than in those of women with NPs. Conclusions: Abnormal CEACAM1/Tim-3 regulation may participate in the development of PE, accompanied by disturbed Th2 cell predominance and higher cytotoxicity of decidual CD8+T cells.
- Published
- 2021
- Full Text
- View/download PDF
14. Anti-inflammatory quinolizidine alkaloids from the aerial parts of Sophora tonkinensis
- Author
-
Dan Liu, Rui-Rong Ye, Zhi-Jun Zhang, Rong-Tao Li, Xuan-Qin Chen, and Yuan-Ya Zhang
- Subjects
Quinolizidine ,Traditional medicine ,biology ,medicine.drug_class ,Sophora tonkinensis ,Plant Science ,biology.organism_classification ,Biochemistry ,Anti-inflammatory ,chemistry.chemical_compound ,chemistry ,medicine ,No production ,Agronomy and Crop Science ,Biotechnology - Abstract
Seventeen quinolizidine alkaloids, including two new ones, 5-hydoxy-7,11-dehydromatrine (1) and 11-hydroxylupanine (2), were isolated from the aerial parts of Sophora tonkinensis. The structures of the isolates were elucidated using 1D and 2D NMR analyses, as well as HR-ESI-MS spectroscopic data. The anti-inflammatory activities of all the isolates on NO production in RAW 264.7 cells stimulated by lipopolysaccharide (LPS) were evaluated. Compounds 3, 4, 13, and 14 were shown to have moderate anti-inflammatory effects.
- Published
- 2021
- Full Text
- View/download PDF
15. Research on Short-Term Wind Power Forecasting by Data Mining on Historical Wind Resource
- Author
-
Bin Tang, Yan Chen, Qin Chen, and Mengxing Su
- Subjects
lomnaofski norm ,rbf neural network ,fig-elman network ,deterministic wind power predication ,wind power interval predication ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
In order to enhance the accuracy of short-term wind power forecasting (WPF), a short-term wind power forecasting method based on historical wind resources by data mining has been designed. Firstly, the spoiled data resulting from wind turbine and meteorological monitoring equipment is eliminated, and the missing data is added by the Lomnaofski optimization model, which is based on the temporal-spatial correlation of meteorological data. Secondly, the wind characteristics are analyzed by the continuous time similarity clustering (CTSC) method, which is used to select similar samples. To improve the accuracy of deterministic prediction and prediction error, the radial basis function neural network (RBF) deterministic forecasting model was built, which can approximate nonlinear solutions. In addition, the wind power interval prediction method, combining fuzzy information granulation and an Elman neural network (FIG-Elman), is proposed to acquire forecasting intervals. The deterministic prediction of the RBF-CTSC model has high accuracy, which can accurately describe the randomness, fluctuation and nonlinear characteristics of wind speed. Additionally, the mean absolute error (MAE) and root mean square error (RMSE) are reduced by the new model. The interval prediction of FIG-Elman results show that the interval width decreased by 18.85%, and the coverage probability of interval increased by 10.94%.
- Published
- 2020
- Full Text
- View/download PDF
16. Nonlinear Maximum Power Point Tracking Control Method for Wind Turbines Considering Dynamics
- Author
-
Liangwen Qi, Liming Zheng, Xingzhi Bai, Qin Chen, Jiyao Chen, and Yan Chen
- Subjects
wind turbines ,mppt ,nonlinear regulation ,state estimate ,torque error feed-forward ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
A combined strategy of torque error feed-forward control and blade-pitch angle servo control is proposed to improve the dynamic power capture for wind turbine maximum power point tracking (MPPT). Aerodynamic torque is estimated using the unscented Kalman filter (UKF). Wind speed and tip speed ratio (TSR) are estimated using the Newton−Raphson method. The error between the estimated aerodynamic torque and the steady optimal torque is used as the feed-forward signal to control the generator torque. The gain parameters in the feed-forward path are nonlinearly regulated by the estimated generator speed. The estimated TSR is used as the reference signal for the optimal blade-pitch angle regulation at non-optimal TSR working points, which can improve the wind power capture for a wider non-optimal TSR range. The Fatigue, Aerodynamics, Structures, and Turbulence (FAST) code is used to simulate the aerodynamics and mechanical aspects of wind turbines while MATLAB/SIMULINK is used to simulate the doubly-fed induction generator (DFIG) system. The example of a 5 MW wind turbine model reveals that the new method is able to improve the dynamic response of wind turbine MPPT and wind power capture.
- Published
- 2020
- Full Text
- View/download PDF
17. Microporous Sulfur-Doped Carbon Atoms as Supports for Sintering-Resistant Platinum Nanocluster Catalysts
- Author
-
Hai-Wei Liang, Shuai Li, Wei-Jie Zeng, Xiaodong Zhuang, Le Zhang, Zhi-Qin Chen, Lei Tong, Qian-Qian Yang, and Shengqi Chu
- Subjects
Materials science ,chemistry ,Chemical engineering ,Doped carbon ,Sintering ,chemistry.chemical_element ,General Materials Science ,Microporous material ,Platinum ,Sulfur ,Catalysis - Published
- 2021
- Full Text
- View/download PDF
18. Effect of Directional Stretching on Properties of PVA-HA-PAA Composite Hydrogel
- Author
-
Tian Zong, Kai Chen, Dekun Zhang, Qin Chen, Siyu Liu, Xuehui Yang, and Yong Luo
- Subjects
Materials science ,Composite number ,Biophysics ,Bioengineering ,Microstructure ,Polyvinyl alcohol ,chemistry.chemical_compound ,chemistry ,Self-healing hydrogels ,Ultimate tensile strength ,medicine ,Crystallite ,Composite material ,Swelling ,medicine.symptom ,Elastic modulus ,Biotechnology - Abstract
Polyvinyl alcohol (PVA) hydrogels with excellent characteristics are considered as promising cartilage replacement materials. However, there are still some main issues to be solved for PVA hydrogel, such as poor mechanical strength and disordered structure. Inspired by the highly ordered structure of biological soft tissues such as articular cartilage, here, we prepared a high-strength but anisotropic polyvinyl alcohol-nanohydroxyapatite-polyacrylic acid (PVA-HA-PAA) composite hydrogel by directional stretching, freezing–thawing, and annealing method. Stretching of an as-prepared isotropic PVA-HA-PAA composite hydrogel leads to the orientation of PVA crystallites and PVA chains, which enables the formation of ordered structure and more hydrogen bonds via freezing under stretching. The microstructure, water content, swelling and creep performance, tensile and bio-tribology properties of the composite hydrogel are studied, the results indicated that the properties of the hydrogel are affected by stretching due to the formation of ordered structure in the anisotropic hydrogel. For instance, the elastic modulus and tensile strength of the anisotropic hydrogel reach 5.703 MPa and 18.958 MPa, respectively, which is significantly enhanced by comparing with isotropic hydrogel. Moreover, the friction property is anisotropic, and the Coefficient Of Friction (COF) reduced in the parallel direction. Thus, this work provides a simple and practicable strategy to design strong and anisotropic hydrogels for potential applications in biomedical materials such as cartilage substitute.
- Published
- 2021
- Full Text
- View/download PDF
19. The transcription factor PjERF1 enhances the biosynthesis of triterpenoid saponins in Panax japonicus
- Author
-
Yilin Yu, Xiuming Cui, Feng Ge, Ren Zhao, Xiang Zhang, Jinyu Zhang, Diqiu Liu, and Qin Chen
- Subjects
fungi ,Protein domain ,Promoter ,Plant Science ,Biology ,Subcellular localization ,biology.organism_classification ,chemistry.chemical_compound ,Open reading frame ,Biochemistry ,Biosynthesis ,chemistry ,Transcription factor ,Gene ,Biotechnology ,Plant secondary metabolism - Abstract
The ERF-type transcription factors (TFs) play vital roles in plant secondary metabolism. ERF TFs simultaneously regulate the expression levels of key enzyme genes involved in the biosynthesis of secondary metabolites due to its “multi-point control” function. In this study, one gene of ERF TFs from Panax japonicus (PjERF1) was cloned. The open reading frame of PjERF1 was 801 bp and encoded 266 amino acids. Phylogenetic analysis showed that PjERF1 belonged to ERF subfamily with a typical conserved domain. Subcellular localization found that PjERF1 protein might be located in eukaryotic cell nucleus. Yeast one-hybrid assay demonstrated that PjERF1 could bind to the promoters of PjβAS, PjCAS, and PjSE specifically and regulate the expression levels of such key enzyme genes involved in the triterpene saponins biosynthesis. Therefore, in the PjERF1 overexpression cell lines, the expression levels of some key enzyme genes involved in the triterpenoid saponins biosynthesis were significantly increased compared with those in non-transgenic cell line. As a result of it, the biosynthesis of chikusetsusaponin IV and IVa, and other ginsenosides (Rd, Rb1, Re, and R0) were also promoted in the PjERF1 overexpression cell lines. This study indicated that PjERF1 could regulate the biosynthesis of saponins in P. japonicus through controlling the expression levels of key enzyme genes related to the biosynthesis of triterpenoid saponins.
- Published
- 2021
- Full Text
- View/download PDF
20. One new lignan and one new fluorenone from Dendrobium nobile Lindl
- Author
-
Li Yang, Xue Cao, Hui-Qin Chen, Hao Wang, Sheng-Zhuo Huang, Cai-Hong Cai, Hao-Fu Dai, Wen-Li Mei, Ling Wang, and Yan-Mei Wei
- Subjects
Lignan ,biology ,010405 organic chemistry ,Chemistry ,Stereochemistry ,Plant Science ,biology.organism_classification ,01 natural sciences ,Biochemistry ,Dendrobium nobile ,0104 chemical sciences ,010404 medicinal & biomolecular chemistry ,chemistry.chemical_compound ,Fluorenone ,medicine ,Cytotoxicity ,Agronomy and Crop Science ,Two-dimensional nuclear magnetic resonance spectroscopy ,IC50 ,Inhibitory effect ,Biotechnology ,Acarbose ,medicine.drug - Abstract
Two new compounds, dendronobilate (1) and 4-O-demethyl-nobilone (2), together with one known fluorenone were isolated from the aerial parts of Dendrobium nobile Lindl. Their structures were characterized by detailed analysis of 1D and 2D NMR spectra, HRESIMS and ECD spectra. Compounds 1–3 showed significant α-glucosidase inhibitory activity with IC50 values of 27.46 ± 3.14, 4.52 ± 0.33, and 10.78 ± 2.05 μM, respectively, which were superior to the acarbose (745.9 ± 3.3 μM). The binding interactions of 1 and 2 with α-glucosidase were investigated using molecular docking simulations. In addition, compound 2 exhibited potent inhibitory effect on NO production in LPS activated RAW264.7 cells with the IC50 value of 35.40 ± 1.77 μM without cytotoxicity observed.
- Published
- 2021
- Full Text
- View/download PDF
21. Carboxylcellulose hydrogel confined-Fe3O4 nanoparticles catalyst for Fenton-like degradation of Rhodamine B
- Author
-
Yuanlong Guo, Lijie Hu, Lihua Zhang, Guanglong Zou, Songmiao Liang, Haibo Xie, Xianyi Zhu, Qin Chen, and Michael North
- Subjects
0303 health sciences ,Ion exchange ,Composite number ,02 engineering and technology ,General Medicine ,021001 nanoscience & nanotechnology ,Biochemistry ,Decomposition ,Catalysis ,Acylation ,03 medical and health sciences ,chemistry.chemical_compound ,Chemical engineering ,chemistry ,Structural Biology ,Rhodamine B ,Cellulose ,0210 nano-technology ,Hydrogen peroxide ,Molecular Biology ,030304 developmental biology - Abstract
Facile preparation of functional hydrogel materials for environmental catalysis is a hot research topic of soft materials science and green catalysis. In this study, a carboxylcellulose hydrogel confined Fe3O4 nanoparticles composite catalyst (Fe3O4@CHC) with magnetic recyclability has been synthesized by taking the advantages of the newly developed cellulose solution in tetramethyl guanidine/DMSO/CO2 through in situ acylation using mixed cyclic anhydrides and ion exchange reaction. The achieved Fe3O4@CHC hydrogel catalyst was shown to be an more efficient and better Fenton-like catalyst for decomposition of the organic dye rhodamine B (RhB) in the presence of hydrogen peroxide, with almost complete decomposition occurring within 180 min, in comparison with Fe3O4@cellulose hydrogel (CH) with excellent recyclability. This work provided a facile strategy for the preparation of hydrogel-based functional composite green catalytic materials, which has potential applications in green catalysis.
- Published
- 2021
- Full Text
- View/download PDF
22. Chemical constituents from Laggera pterodonta and their anti-inflammatory activities in vitro
- Author
-
Xuan-Qin Chen, Xin-Ye Du, Yan-Qing Xie, Dan Liu, Rong-Tao Li, and Zhi-Jun Zhang
- Subjects
Lignan ,Traditional medicine ,010405 organic chemistry ,medicine.drug_class ,Plant Science ,Norisoprenoids ,01 natural sciences ,Biochemistry ,Anti-inflammatory ,In vitro ,0104 chemical sciences ,010404 medicinal & biomolecular chemistry ,chemistry.chemical_compound ,chemistry ,Phytochemical ,Chemical constituents ,medicine ,Laggera pterodonta ,No production ,Agronomy and Crop Science ,Biotechnology - Abstract
A phytochemical investigation on the aerial parts of Laggera pterodonta resulted in the isolation and identification of 23 compounds, including twelve sesquiterpenoids (1–12), two norisoprenoids (13, 14), three alkaloids (15-17), one lignan (18), and five flavonoids (19-23). Among them, norpterodonols A (1) and B (2) are two undescribed norsesquiterpenoid derivatives. Their structures were established on the basis of NMR and HR-ESI-MS spectroscopic analysis. All isolates were evaluated for their inhibitory effects on the NO production in LPS-induced RAW 264.7 macrophages, and compounds 8, 10, 16, 18, 20, 21, and 23 were shown to have obvious anti-inflammatory effects.
- Published
- 2021
- Full Text
- View/download PDF
23. Three new tirucallane triterpenoids from the fruits of Chukrasia tabularis and their biological activities
- Author
-
Jia-Meng Hu, Hao-Fu Dai, Yan-Mei Wei, Hao Wang, Zhi-Hang Zhuo, Hui-Qin Chen, Zi-An Cheng, Shou-Bai Liu, Cui-Juan Gai, Wen-Li Mei, and Xuan Dong
- Subjects
010405 organic chemistry ,Stereochemistry ,Chemistry ,Chukrasia tabularis ,Tumor cells ,Plant Science ,01 natural sciences ,Biochemistry ,0104 chemical sciences ,010404 medicinal & biomolecular chemistry ,Triterpenoid ,Ic50 values ,Agronomy and Crop Science ,Two-dimensional nuclear magnetic resonance spectroscopy ,Biotechnology - Abstract
Three new triterpenoids (1–3), including two new 19 (10 → 9β) abeo-tirucallane derivatives (1–2) and a new tirucallane-type triterpenoid (3), together with two known tirucallane-type triterpenoids (4–5) were isolated from the ethanol extract of the fruits of Chukrasia tabularis. Their structures were elucidated on the basis of 1D and 2D NMR spectroscopic analyses and MS data. The isolated triterpenoids 1 and 2 exhibited anti-inflammatory activities with IC50 values of 75.98 ± 2.12 and 24.86 ± 1.16 μM, respectively. Compound 5 showed cytotoxic activities against the selected tumor cell lines.
- Published
- 2021
- Full Text
- View/download PDF
24. Preparation and characterization of polyvinyl alcohol/ sodium alginate/carboxymethyl cellulose composite hydrogels with oriented structure
- Author
-
Kai Chen, Tian Zong, Linmin Xu, Dekun Zhang, Siyu Liu, and Qin Chen
- Subjects
Chemistry ,Articular cartilage ,General Chemistry ,Condensed Matter Physics ,Polyvinyl alcohol ,Characterization (materials science) ,Carboxymethyl cellulose ,Composite hydrogels ,chemistry.chemical_compound ,Chemical engineering ,medicine ,General Materials Science ,Sodium alginate ,medicine.drug - Abstract
In order to control complex motion behavior in organisms, most biological tissues have highly oriented structures and anisotropic mechanical properties, such as articular cartilage, muscle, skin an...
- Published
- 2021
- Full Text
- View/download PDF
25. Effects of soil amendments on soil fertility and fruit yield through alterations in soil carbon fractions
- Author
-
Xiaohu Zhao, Xuecheng Sun, Zhihao Dong, Liu Xiaodong, Xiaomin Liang, Qin Chen, Songwei Wu, Chengxiao Hu, Muhammad Shoaib Rana, and Qiling Tan
- Subjects
Nutrient cycle ,Chemistry ,Stratigraphy ,food and beverages ,04 agricultural and veterinary sciences ,Soil carbon ,010501 environmental sciences ,engineering.material ,Straw ,complex mixtures ,01 natural sciences ,Soil conditioner ,Nutrient ,Agronomy ,040103 agronomy & agriculture ,engineering ,0401 agriculture, forestry, and fisheries ,Fertilizer ,Soil fertility ,Mulch ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
Soil fertility plays a key role in citrus productivity. Therefore, it is necessary to explore the effects of soil amendments on soil fertility and citrus productivity and estimate carbon fractions’ suitability, which response to soil fertility and citrus productivity. A field experiment in a citrus orchard was conducted containing five treatments: local habit fertilization (LF), special fertilizer [25% lower NPK than LF, (SF)], special fertilizer, and rice straw mulching [0%, 12.5%, and 25% NPK higher than LF (SFRS25, SFRS37.5, and SFRS50, respectively)]. Total organic carbon (TOC), microbial biomass carbon (MBC), water-soluble organic carbon (WSOC), permanganate oxidizable carbon (ROC), available N, P, K, fruit yield, and quality were analyzed. Straw mulching and special fertilizer significantly increased soil carbon fractions, such as MBC and ROC. Such treatments also enhanced the soil available N, P, and K, subsequently elevated the fruit yield. MBC, available K, and available P showed a significantly positive correlation with citrus yield. Redundancy analysis indicated that MBC and ROC significantly explained 61.87% of the variation for available nutrients, suggesting that the increase of organic carbon fractions and microbial biomass could accelerate nutrient cycling for the plant. It proved that decrement application of special compound fertilizer with straw mulching raised fruit yield by altering soil carbon fractions to improve soil available nutrients or fertility. The MBC of soil labile carbon responded more sensitively to not only soil fertility but also citrus fruit yield.
- Published
- 2021
- Full Text
- View/download PDF
26. Porous layered La0.6Sr0.4Co0.2Fe0.8O3 perovskite with enhanced catalytic activities for oxygen reduction
- Author
-
Yong-min Xie, Zhifeng Xu, Ruixiang Wang, Xiaocong Zhong, Xiao-yun Xie, Jiaming Liu, Zhe-qin Chen, Wei-lai Xu, and Tian-yu Chen
- Subjects
Materials science ,Metals and Alloys ,General Engineering ,Oxide ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Catalysis ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Specific surface area ,Electrode ,Reversible hydrogen electrode ,Diffusion current ,0210 nano-technology ,Porosity ,Perovskite (structure) - Abstract
Low-cost catalysts with high activity are in immediate demand for energy storage and conversion devices. In this study, polyvinyl pyrrolidone was used as a complexing agent to synthesize La0.6Sr0.4Co0.2Fe0.8O3 (LSCF) perovskite oxide. The obtained porous layered LSCF has a large specific surface area of 23.74 m2/g, four times higher than that prepared by the traditional sol-gel method (5.08 m2/g). The oxygen reduction reaction activity of the oxide in 0.1 mol/L KOH solution was studied using a rotating ring-disk electrode. In the tests, the initial potential of 0.88 V (vs. reversible hydrogen electrode) and the limiting diffusion current density of 5.02 mA/cm2 were obtained at 1600 r/min. Therefore, higher catalytic activity and stability were demonstrated, compared with the preparation of LSCF perovskite oxide by the traditional method.
- Published
- 2021
- Full Text
- View/download PDF
27. Room Temperature Syntheses, Crystal Structures and Magnetic Properties of One Novel Decanuclear Copper Cluster Based on 3-amino-1,2,4 triazole Schiff Base
- Author
-
Yujie Zhang, Guangzhao Li, Hai-Yang Zhang, Shu-Hua Zhang, and Qin Chen
- Subjects
Materials science ,Schiff base ,chemistry.chemical_element ,Infrared spectroscopy ,02 engineering and technology ,General Chemistry ,Crystal structure ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Biochemistry ,Copper ,0104 chemical sciences ,Catalysis ,chemistry.chemical_compound ,Crystallography ,chemistry ,Cluster (physics) ,Antiferromagnetism ,General Materials Science ,3-Amino-1,2,4-triazole ,0210 nano-technology - Abstract
One novel decanuclear copper cluster, {[Cu10(L)8(CH3COO)2(μ3- OH)2]·(DMF)2·(H2O)5} (1, H2L = (E)- 2-(((4H-1,2,4-triazol-3-yl)imino)methyl)-6-methoxyphenol, DMF = N,N’-dimethyl-formamide), were obtained by room temperature micro-bottle reaction. The complex 1 was characterized using elemental analysis, infrared spectroscopy and single-crystal X-ray diffractometry. 1 is decanuclear copper cluster. The {Cu10O4(N2triazol)8} core displays dominant antiferromagnetic interactions owing to the μ3-OH, and μ2-Ophenoxo bridged binding modes with g = 2.126, J = − 6.81 $$\times {10}^{-4}$$ cm−1, and zJ’ = − 0.577 cm−1.
- Published
- 2021
- Full Text
- View/download PDF
28. Effect of roasted peanut allergen Ara h 3 protein on the sensitization of Caco‐2 cells
- Author
-
Zhirui Deng, Xiaodong Sun, Minjia Wang, Qin Chen, Shuo Wang, and Bing Niu
- Subjects
Thymic stromal lymphopoietin ,Arachis ,030309 nutrition & dietetics ,medicine.medical_treatment ,Peanut allergy ,Receptors, Cell Surface ,medicine.disease_cause ,Occludin ,03 medical and health sciences ,0404 agricultural biotechnology ,Intestine, Small ,medicine ,Humans ,Peanut Hypersensitivity ,Viability assay ,Chemokine CCL2 ,Sensitization ,Plant Proteins ,0303 health sciences ,Nutrition and Dietetics ,Interleukin-6 ,Chemistry ,Interleukin-8 ,NF-kappa B ,food and beverages ,Epithelial Cells ,04 agricultural and veterinary sciences ,Allergens ,Antigens, Plant ,medicine.disease ,040401 food science ,Molecular biology ,Cytokine ,medicine.anatomical_structure ,Caco-2 ,Seeds ,Zonula Occludens-1 Protein ,Caco-2 Cells ,Cell Adhesion Molecules ,Agronomy and Crop Science ,Oxidative stress ,Food Science ,Biotechnology - Abstract
Background Roasted peanut is widely loved as a kind of food with rich taste. However, peanut allergy is one of the major threats to human health, which affects about 5% of children and 1.4-2% of adults in the world. Results To evaluate the sensitization mechanism of peanut allergen Ara h 3, Caco-2 cells as the model, which has the similar structure and function to differentiated small intestinal epithelial cells. Compared with Ara h 3-raw (purified from raw peanut) group, more significant results such as the inhibited Caco-2 cell viability and proliferation, the increased secretion of reactive oxygen species (ROS) and the decreased transepithelial electrical resistance were obtained in Ara h 3-roasted (purified from roasted peanut) group. Accordingly, oxidative stress and NF-κB signaling pathway were more imbalanced, which lead to the increased of thymic stromal lymphopoietin (TSLP), interleukin 6 (IL-6), IL-8 and monocyte chemotactic protein 1 (MCP-1). Then, the gene expression of tight junction proteins ZO-1, occludin and JAM-1 were reduced, which proved that the integrity of the Caco-2 monolayer barrier is severely damaged. Conclusion These finding identify the mechanisms of the allergenicity of roasted peanut allergy proteins are probably associated with intestinal uptake and cytokine dependent allergies. The aggravated allergic reaction might be caused by the increment of TSLP, IL-6, IL-8 and MCP-1 due to the activated NF-κB signaling pathway, and the enhanced transport of Ara h 3-roasted protein by Caco-2 monolayer. © 2021 Society of Chemical Industry.
- Published
- 2021
- Full Text
- View/download PDF
29. Evaluation of Poly(glycidyl methacrylate)-Coated Column for Enantioseparation with Azithromycin Lactobionate and Clindamycin Phosphate as Chiral Selectors in Capillary Electrophoresis
- Author
-
Qin Chen, Cheng Chen, Ke Yang, Tao Yu, Wen Ding, and Xiaodong Sun
- Subjects
Glycidyl methacrylate ,Chromatography ,010405 organic chemistry ,Chemistry ,Capillary action ,010401 analytical chemistry ,Organic Chemistry ,Clinical Biochemistry ,Nanoparticle ,Electrolyte ,AutoDock ,01 natural sciences ,Biochemistry ,0104 chemical sciences ,Analytical Chemistry ,chemistry.chemical_compound ,Capillary electrophoresis ,Clindamycin Phosphate ,Enantiomer - Abstract
In this study, a poly(glycidyl methacrylate) nanoparticle (PGMA NP)-coated column system with two antibiotics as selector was constructed for enantioseparation. The PGMA NP coating inside the capillary columns could be easily introduced by a simple ring open reaction. Five basic drugs were used as the model to evaluate the enantioselectivity of Azithromycin Lactobionate (AL) and Clindamycin phosphate (CP)-based separation system. Factors that influence the chiral separation resolution were systematically investigated, such as chiral selector concentration, background electrolyte (BGE) pH, applied voltage and system temperature. Under the optimized conditions, improved enantioseparations were obtained for all enantiomers and the maximum column efficiency of model drugs could reach 120,000 plates/m. The repeatability of relative standard deviations for EOF representing run-to-run, day-to-day and column-to-column was less than 4.32%. In addition, molecular modeling with AutoDock was applied to elucidate the explored potential mechanism of AL/CP for recognizing racemic drugs.
- Published
- 2021
- Full Text
- View/download PDF
30. Bioactive dihydroagarofuran sesquiterpenes from the twigs of Tripterygium hypoglaucum
- Author
-
Xuan-Qin Chen, Zhi-Jun Zhang, Hui Zheng, Juan Wu, Rong-Tao Li, Dan Liu, and Rui-Rong Ye
- Subjects
010405 organic chemistry ,Chemistry ,Tripterygium hypoglaucum ,Moderate activity ,Plant Science ,01 natural sciences ,Biochemistry ,Molecular biology ,0104 chemical sciences ,Multiple drug resistance ,010404 medicinal & biomolecular chemistry ,Cell culture ,No production ,Cytotoxicity ,Agronomy and Crop Science ,IC50 ,Biotechnology - Abstract
Thirteen undescribed dihydroagarofuran sesquiterpenes, hypogricins A-M, were isolated from the twigs of Tripterygium hypoglaucum. Extensive spectroscopic techniques were used for the structural elucidation of these compounds. All the compounds showed no significant cytotoxicity against adriamycin-sensitive HepG-2 and adriamycin-resistant HepG-2/Adr cell lines. When HepG-2/Adr cell line was co-treated with those compounds plus adriamycin, hypogricins A and B showed potent activity to reverse multidrug resistance (MDR) of HepG2/Adr cells to adriamycin (reversal fold: RF = 102 and 200, respectively). In addition, hypogricins E, H, and L showed moderate activity to inhibit NO production in LPS-stimulated RAW264.7 cells with the IC50 of 22.3, 17.8, and 19.8 μM, respectively.
- Published
- 2021
- Full Text
- View/download PDF
31. Gecko foot-inspired reduced graphene oxide surface with multi-resistant, nonpolar/polar separation and reliable adhesion utility
- Author
-
Guofeng Zhang, Qin Chen, Fuchao Yang, Jing Fu, and Guopeng Chen
- Subjects
Materials science ,Graphene ,020502 materials ,Mechanical Engineering ,Sonication ,fungi ,Oxide ,02 engineering and technology ,Surface finish ,Adhesion ,law.invention ,Contact angle ,chemistry.chemical_compound ,0205 materials engineering ,Chemical engineering ,chemistry ,Mechanics of Materials ,law ,General Materials Science ,Adhesive ,Ethylene glycol - Abstract
Nature offers intriguing examples for adhesive surface with superhydrophobicity, like gecko foot hair and red rose petals. The superhydrophobic adhesion surface mainly depends on its ingenious hierarchical structure and chemical composition. Utilizing biomimetic strategy, we synthesized a fluorosulfurized reduced graphene oxide powder with a hierarchical structure by post-processing of graphene oxide. The adhesive fluorine-sulfurized reduced graphene cotton (AFC) was successfully prepared by ultrasonic soaking, self-assembly and drying. The water contact angle of AFC was 154° ± 1.4°, and its maximum adhesion force was about 102.9 ± 4.9 μN. The AFC exhibited excellent high superhydrophobic adhesive because it possessed not only the C–F bond and microscopic morphology of wrinkles and protrusions but also the inherent roughness of cotton fabrics. Importantly, the high superhydrophobic adhesive properties of AFC were not attenuated by sonication for 200 mins or UV exposure for 30 hours. Interestingly, AFC had prominent oleophobic properties for certain organic solvents (e.g., glycerol, ethylene glycol, etc.) with surface tensions greater than 30 mN/m. Finally, AFC was successfully used to nonpolar/polar separation and transfer droplets to various accepted surfaces (e.g., copper sheets, stainless steel mesh, plastics, etc.), demonstrating its great potential in liquid mixture separation and microdroplet transport.
- Published
- 2021
- Full Text
- View/download PDF
32. Additive engineering for Sn-based PSCs: Enhancement of open-circuit voltage and fill factor
- Author
-
Jadel Tsiba Matondo, Minghan Deng, Davy Malouangou Maurice, Qin Chen, Mina Guli, and Luyun Bai
- Subjects
Fabrication ,Materials science ,Passivation ,Renewable Energy, Sustainability and the Environment ,Band gap ,Open-circuit voltage ,020209 energy ,chemistry.chemical_element ,Nanotechnology ,02 engineering and technology ,021001 nanoscience & nanotechnology ,law.invention ,Crystallinity ,chemistry ,law ,0202 electrical engineering, electronic engineering, information engineering ,General Materials Science ,Crystallization ,0210 nano-technology ,Tin ,Perovskite (structure) - Abstract
Perovskite solar cells (PSCs) have drawn much attention recently because of their outstanding photo-electrical performance, especially lead halide perovskites. However, the high toxicity of lead contained in perovskite severely hinders further development of the devices in industrial production and commercial applications. As a result, Tin, as one of the non-toxic metal elements exhibiting similar electronic properties with Pb, has been considered as the most suitable ions to substitute toxic Pb in PSCs. However, Sn-based PSCs also face serious challenges such as high intrinsic defects density which mainly originates from Sn2+ oxidation and fast crystallization which will cause poor film morphology, serious recombination and result in poor Voc and FF. To overcome these defects, additive engineering is introduced into the fabrication of Sn-based perovskites and has already achieved remarkable progress in improving opto-electrical performance through film morphology modification, crystallinity enhancement, defect passivation and band gap optimization. This review discussed the corresponding researches on additives which show outstanding efficacy to optimize the Voc and FF of Sn-based PSCs and it can be concluded that additives engineering has indispensable effect on achieving high performance Sn-based devices and the future development of Sn-based PSCs.
- Published
- 2021
- Full Text
- View/download PDF
33. Facile and green approach towards biomass-derived hydrogel powders with hierarchical micro-nanostructures for ultrafast hemostasis
- Author
-
Lan Feng, Jianxu Bao, Changsheng Zhao, Weifeng Zhao, Qin Chen, Huitong Cheng, and Wenbin Shi
- Subjects
Adult ,Erythrocytes ,Absorption of water ,Nanostructure ,Alginates ,Biomedical Engineering ,Biocompatible Materials ,macromolecular substances ,Calcium Hydroxide ,Rats, Sprague-Dawley ,Chitosan ,chemistry.chemical_compound ,Blood loss ,Materials Testing ,Animals ,Humans ,General Materials Science ,Biomass ,Platelet activation ,Particle Size ,Blood Coagulation ,Cell Aggregation ,Hemostasis ,technology, industry, and agriculture ,Water ,Hydrogels ,General Chemistry ,General Medicine ,Platelet Activation ,Nanostructures ,Rats ,chemistry ,Chemical engineering ,Self-healing hydrogels ,Subcutaneous implantation ,Rabbits ,Powders ,Porosity - Abstract
Although a series of biomass-derived hemostats has been developed, the desire for green-prepared hemostatic materials with biosafety has not decreased. Herein, we constructed porous carboxymethyl chitosan/sodium alginate/Ca(OH)2 powders (PCSCPs) with suitable adaptability for instant control of irregular hemorrhage via a facile and green approach. By one-pot chemical crosslinking of carboxymethyl chitosan and sodium alginate, hydrogels were formed and immediately ionically cross-linked along with the generation of Ca(OH)2 to prepare PCSCPs. As hydrogel powders, PCSCPs with abundant hydrophilic carboxymethyl groups and porous hierarchically micro-nanostructures displayed a high water absorption ratio of over 1600%. The PCSCPs were confirmed with favorable hemocompatibility, non-cytotoxic effects and excellent degradability. Hemostasis assays in vitro showed that PCSCPs possessed an outstanding property of platelet activation and red blood cell aggregation. The PCSCPs effectively shortened the hemostatic time and blood loss to ca. 50% in rodent bleeding models compared with medical gauze and commercial chitosan-based hemostats. Furthermore, a mouse subcutaneous implantation model demonstrated an ignorable inflammation response and potential tissue repair capability of PCSCPs. It's believed that green-prepared and biomass-derived PCSCPs are feasible biomedical hemostatic materials in view of engineering and provide a promising platform to design hemostats in prehospital management and clinical settings.
- Published
- 2021
- Full Text
- View/download PDF
34. β-Amyloid PET and 123I-FP-CIT SPECT in Mild Cognitive Impairment at Risk for Lewy Body Dementia
- Author
-
Val J. Lowe, Toji Miyagawa, Walter K. Kremers, Hoon Ki Min, Jeffrey L. Gunter, Julie A. Fields, Clifford R. Jack, Qin Chen, Ronald C. Petersen, Jonathan Graff-Radford, Kejal Kantarci, Christopher G. Schwarz, Rodolfo Savica, Bradley F. Boeve, David S. Knopman, Scott A. Przybelski, Tanis J. Ferman, Neill R. Graff-Radford, David T.W. Jones, Timothy G. Lesnick, and Matthew L. Senjem
- Subjects
0301 basic medicine ,medicine.medical_specialty ,Standardized uptake value ,Gastroenterology ,REM sleep behavior disorder ,Article ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Internal medicine ,mental disorders ,medicine ,Dementia ,Dopamine transporter ,biology ,Lewy body ,business.industry ,Dementia with Lewy bodies ,Putamen ,medicine.disease ,030104 developmental biology ,chemistry ,biology.protein ,Neurology (clinical) ,Pittsburgh compound B ,business ,030217 neurology & neurosurgery - Abstract
ObjectiveTo determine the clinical phenotypes associated with the β-amyloid PET and dopamine transporter imaging (123I-FP-CIT SPECT) findings in mild cognitive impairment (MCI) with the core clinical features of dementia with Lewy bodies (DLB; MCI-LB).MethodsPatients with MCI who had at least 1 core clinical feature of DLB (n = 34) were grouped into β-amyloid A+ or A− and 123I-FP-CIT SPECT D+ or D− groups based on previously established abnormality cut points for A+ with Pittsburgh compound B PET standardized uptake value ratio (PiB SUVR) ≥1.48 and D+ with putamen z score with DaTQUANT 123I-FP-CIT SPECT. Individual patients with MCI-LB fell into 1 of 4 groups: A+D+, A+D−, A−D+, or A−D−. Log-transformed PiB SUVR and putamen z score were tested for associations with patient characteristics.ResultsThe A−D+ biomarker profile was most common (38.2%), followed by A+D+ (26.5%) and A−D− (26.5%). The least common was the A+D- biomarker profile (8.8%). The A+ group was older, had a higher frequency of APOE ε4 carriers, and had a lower Mini-Mental State Examination score than the A− group. The D+ group was more likely to have probable REM sleep behavior disorder. Lower putamen DaTQUANT z scores and lower PiB SUVRs were independently associated with higher Unified Parkinson’s Disease Rating Scale-III scores.ConclusionsA majority of patients with MCI-LB are characterized by low β-amyloid deposition and reduced dopaminergic activity. β-Amyloid PET and 123I-FP-CIT SPECT are complementary in characterizing clinical phenotypes of patients with MCI-LB.
- Published
- 2021
35. Engineering cellulose into water soluble poly(protic ionic liquid) electrolytes in the DBU/CO2/DMSO solvent system as an organocatalyst for the Knoevenagel condensation reaction
- Author
-
Yuqing Shen, Chaoping Yuan, Qin Chen, Haibo Xie, Shengjun Lu, and Xianyi Zhu
- Subjects
Solvent ,chemistry.chemical_compound ,Aqueous solution ,Nucleophilic addition ,Dehydration reaction ,Chemistry ,Ionic liquid ,Succinic anhydride ,Environmental Chemistry ,Organic chemistry ,Knoevenagel condensation ,Pollution ,Catalysis - Abstract
The facile design and preparation of polyelectrolytes is a frontier topic in the fields of polymer science, energy storage devices and catalysis. Herein, linear water soluble cellulosic poly(protic ionic liquid) (CPIL) electrolytes were facilely and atom economically prepared after the dissolution of cellulose in the newly developed DBU/CO2/DMSO solvent system, followed by the simple addition of succinic anhydride under mild conditions. The DBU not only participated in the dissolution of cellulose as a solvent component, but also acted as an organocatalyst for the acylation reaction of cellulose with succinic anhydride, as well as a cation component in the targeted CPIL electrolytes. The reaction was optimized, and the effect of the reaction conditions on the chemical and physical properties of the CPILs was investigated. And then, as a proof of concept, the CPIL electrolyte aqueous solution was successfully used as the catalytic reaction media for the Knoevenagel condensation reaction. It was found that the reaction was homogeneous at the beginning, and the products could precipitate out from the media with the proceeding of the reaction, thus affording satisfactory filtration yields ranging from 56.7% to 93.8%. The solution properties of the CPIL aqueous solution were primarily investigated towards an in-depth understanding of the catalytic mechanism, by which a synergetic catalytic mechanism of the CPILs was proposed, and the reaction started with a nucleophilic addition reaction, and was then followed by a fast dehydration reaction. Finally, the direct reusability potential of the CPIL aqueous solution after the product filtration was also primarily investigated for the Knoevenagel condensation reaction.
- Published
- 2021
- Full Text
- View/download PDF
36. Curcumin Activates ROS Signaling to Promote Pyroptosis in Hepatocellular Carcinoma HepG2 Cells
- Author
-
Xiao-Yu Guo, Zi-Yi Wang, Taeho Kwon, Dan-Ping Xie, Dong-Qin Chen, Yi-Xi Gong, Wan-Feng Liang, Fu-Liang Sun, Chen-Xi Ren, Hai-Feng Li, Wei-Long Li, and Hu-Nan Sun
- Subjects
Cancer Research ,Programmed cell death ,Carcinoma, Hepatocellular ,Curcumin ,Apoptosis ,General Biochemistry, Genetics and Molecular Biology ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Pyroptosis ,Humans ,MTT assay ,Viability assay ,Pharmacology ,chemistry.chemical_classification ,Reactive oxygen species ,Liver Neoplasms ,Hep G2 Cells ,chemistry ,030220 oncology & carcinogenesis ,Cancer cell ,Cancer research ,Reactive Oxygen Species ,Research Article - Abstract
Background/aim Curcumin is a polyphenol that exerts a variety of pharmacological activities and plays an anti-cancer role in many cancer cells. It was recently reported that gasdermin E (GSDME) is involved in the progression of pyroptosis. Materials and methods HepG2 cells were treated with various concentrations of curcumin and cell viability was examined using MTT assay, apoptosis was analysed using flow cytometry, reactive oxygen species (ROS) levels using dihydroethidium, LDH release using an LDH cytotoxicity assay, and protein expression using western blot. Results Curcumin increased the expression of the GSDME N-terminus and proteins involved in pyrolysis, promoted HspG2 cell pyrolysis and increased intracellular ROS levels. Moreover, inhibition of the production of intracellular ROS with n-acetylcysteine (NAC) improved the degree of apoptosis and pyrolysis induced by curcumin. Conclusion Curcumin induces HspG2 cell death by increasing apoptosis and pyroptosis, and ROS play a key role in this process. This study improves our understanding of the potential anti-cancer properties of curcumin in liver cancer.
- Published
- 2021
- Full Text
- View/download PDF
37. A target-oriented algorithm for maintaining serum calcium stability automatically in regional citrate anticoagulation
- Author
-
Li-Hong Huang, Zhen-Juan Dai, Xue-Min Wang, Jian-Qin Chen, Ruan-Mei Sheng, and Wen-Biao Zhao
- Subjects
medicine.medical_specialty ,medicine.medical_treatment ,030232 urology & nephrology ,Biomedical Engineering ,Medicine (miscellaneous) ,chemistry.chemical_element ,Bioengineering ,Calcium ,Citric Acid ,Biomaterials ,03 medical and health sciences ,0302 clinical medicine ,Hemofiltration ,Humans ,Medicine ,Citrate anticoagulation ,Citrates ,Renal replacement therapy ,Intensive care medicine ,business.industry ,Critically ill ,Anticoagulants ,030208 emergency & critical care medicine ,General Medicine ,chemistry ,business ,Algorithms - Abstract
Background:Regional citrate anticoagulation (RCA) for renal replacement therapy is widely practiced in critically ill patients. However, concern exists regarding its labor-intensiveness for monitoring and the associated hypocalcemia. In this study, we provided an algorithm for prescribing RCA and evaluated its safety in patients.Methods:During 18 hemofiltration treatments with calcium-free replacement solution, participants were randomized to receive algorithm-based or trial-and-error RCA protocol. The effluent volume, post-filter and in vivo ionized calcium (iCa), and calcium in the sera and effluents were periodically measured at an interval of 1 to 2 h.Results:For patients received algorithm-based RCA protocol, no one had a serum iCa less than 0.9 mmol/L, and none needed calcium supplement adjustment to maintain serum calcium stability. For patients accepted trial-and-error protocol, all patients had a serum iCa below 0.9 mmol/L, their serum iCa and calcium levels fluctuated dramatically, and all patients need additional calcium supplement adjustment during RCA. None of the participants showed a post-filter iCa > 0.4 mmol/L.Conclusion:We provided a safe algorithm for calculating calcium supplementation doses that could maintain serum calcium stability without additional adjustment during RCA.
- Published
- 2020
- Full Text
- View/download PDF
38. Two new 2-phenylethylchromones from artificial agarwood by holing method
- Author
-
Pan Xiang, Hui-Qin Chen, Hao-Fu Dai, Wen-Li Mei, Hao Wang, Fan-Dong Kong, and Yan-Bo Zeng
- Subjects
Ethyl acetate ,Pharmaceutical Science ,Aquilaria sinensis ,engineering.material ,01 natural sciences ,Analytical Chemistry ,chemistry.chemical_compound ,Drug Discovery ,Flavonoids ,Pharmacology ,Molecular Structure ,biology ,Traditional medicine ,Phenylpropanoid ,010405 organic chemistry ,Organic Chemistry ,General Medicine ,Agarwood ,biology.organism_classification ,Wood ,0104 chemical sciences ,010404 medicinal & biomolecular chemistry ,Complementary and alternative medicine ,chemistry ,Thymelaeaceae ,Chromone ,Acetylcholinesterase ,engineering ,Molecular Medicine ,Cholinesterase Inhibitors - Abstract
Two new 2-(2-phenylethyl)chromone derivatives (1–2) were isolated from the ethyl acetate extract of artificial agarwood induced by holing method originating from Aquilaria sinensis (Lour.) Gilg, and they were isolated from this genus for the first time. The structures of these two new compounds were elucidated by extensive spectroscopic analyses, including UV, IR, one- and two-dimensional NMR and HRESIMS measurements. Bioassay tests of these two new compounds showed compounds 1 and 2 had weak inhibitory activity against acetylcholinesterase at a concentration of 50.0 μg/ml.
- Published
- 2020
- Full Text
- View/download PDF
39. Identification of exogenous ABA and heat stress tolerance in various cotton genotypes
- Author
-
Yaping Guo, Fenglei Sun, Yanying Qu, Kai Zheng, Quanjia Chen, Rong Fan, and Qin Chen
- Subjects
Electrolyte leakage ,Drought tolerance ,Plant Science ,Biology ,Heat stress ,Heat tolerance ,Horticulture ,chemistry.chemical_compound ,chemistry ,Genotype ,Genetics ,Stomatal aperture ,Agronomy and Crop Science ,Abscisic acid ,Stomatal density - Abstract
Cotton fibre yield and quality are markedly influenced by drought and high-temperature stress. We examined the traits of the leaf stomata in 39 cotton genotypes subjected to exogenous phytohormone abscisic acid (ABA) signalling, electrolyte leakage under 40°C thermal stress, and relative GhHsfA, GhbZIP and GhHSP70 expression levels under two treatments. Stomatal density and area ranged from 66 to 182/mm2 and 663 to 1305 μm2, respectively. Under exogenous ABA signalling, the changes in stomatal aperture (ΔSAp) were in the range of 2.5–31.2%; ΔSAp and relative GhHsfA, GhbZIP and GhHSP70 expression levels were significantly correlated, respectively. Electrolyte leakage increased unequally among cotton genotypes after heat stress. The changes in electrolyte leakage (ΔEL) and relative GhHsfA, GhbZIP and GhHSP70 expression levels were very strongly correlated, respectively. Their relative expression levels could be used as references for the rapid identification of stress-tolerant cotton strains. Cluster analysis of the 39 cotton genotypes indicated that Xinluzao36, Shiyang1, shinong98-7 and Zhongmiansuo293 are heat- and drought-resistant. We integrated both analysis of physiological parameters and molecular methods to identify cotton varieties with the drought and heat tolerance, in order to provide a reference for the selection of materials and methods for the research and production of cotton.
- Published
- 2020
- Full Text
- View/download PDF
40. Detection of Allergen Genes in Peanut and Soybean by Circular Fluorescence Probe-Mediated Isothermal Amplification
- Author
-
Xueen Fang, Yongxin Liu, Qin Chen, Bing Niu, and Xiaodong Sun
- Subjects
Allergy ,Chemistry ,010401 analytical chemistry ,Soybean allergen ,Loop-mediated isothermal amplification ,food and beverages ,04 agricultural and veterinary sciences ,medicine.disease ,medicine.disease_cause ,040401 food science ,01 natural sciences ,Applied Microbiology and Biotechnology ,Fluorescence ,0104 chemical sciences ,Analytical Chemistry ,0404 agricultural biotechnology ,Immune system ,Allergen ,Biochemistry ,Food allergy ,medicine ,Safety, Risk, Reliability and Quality ,Safety Research ,Gene ,Food Science - Abstract
Food allergy is an abnormal immune response of the human immune system to some foods, which can cause extremely serious harm to the human body. Therefore, the development of a sensitive and rapid detection approach for food allergens in various food matrices is essential to assist patients in managing their allergies. In this paper, a kind of circular fluorescence probe-mediated isothermal amplification technology (CFPA) was developed and used to detect the peanut allergen encoding gene (Ara h 6) and soybean allergen encoding gene (Gly m Bd 28 K). This novel assay could be finished within 60 min with high sensitivity (10 copies/μL~1 × 107 copies/μL), specificity (no cross-reaction with other allergens), and reproducibility (CV
- Published
- 2020
- Full Text
- View/download PDF
41. Mechanisms Regulating Muscle Protein Synthesis in CKD
- Author
-
Zihong Chen, Ying Wang, Jorge L. Gamboa, William E. Mitch, Qin Chen, Liping Zhang, Giacomo Garibotto, and Talat Alp Ikizler
- Subjects
0301 basic medicine ,medicine.medical_specialty ,Muscle biopsy ,medicine.diagnostic_test ,Catabolism ,Protein metabolism ,Inflammation ,General Medicine ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,0302 clinical medicine ,Endocrinology ,chemistry ,Nephrology ,030220 oncology & carcinogenesis ,Internal medicine ,Demethylase activity ,Knockout mouse ,medicine ,Protein biosynthesis ,Myocyte ,medicine.symptom - Abstract
Background CKD induces loss of muscle proteins partly by suppressing muscle protein synthesis. Muscles of mice with CKD have increased expression of nucleolar protein 66 (NO66), as do muscle biopsy specimens from patients with CKD or those undergoing hemodialysis. Inflammation stimulates NO66 expression and changes in NF-κB mediate the response. Methods Subtotal nephrectomy created a mouse model of CKD with BUN >80 mg/dl. Crossing NO66flox/flox with MCK-Cre mice bred muscle-specific NO66 (MCK-NO66) knockout mice. Experiments assessed the effect of removing NO66. Results Muscle-specific NO66 knockout in mice blocks CKD-induced loss of muscle mass and improves protein synthesis. NO66 suppression of ribosomal biogenesis via demethylase activity is the mechanism behind these responses. In muscle cells, expression of NO66, but not of demethylase-dead mutant NO66, decreased H3K4me3 and H3K36me3 and suppressed pre-rRNA expression. Knocking out NO66 increased the enrichment of H3K4me3 and H3K36me3 on ribosomal DNA. In primary muscle cells and in muscles of mice without NO66, ribosomal RNA, pre-rRNA, and protein synthesis all increased. Conclusions CKD suppresses muscle protein synthesis via epigenetic mechanisms that NO66 mediates. Blocking NO66 could suggest strategies that counter CKD-induced abnormal muscle protein catabolism.
- Published
- 2020
- Full Text
- View/download PDF
42. PKMYT1 Promotes Gastric Cancer Cell Proliferation and Apoptosis Resistance
- Author
-
Xiong-Chang Liu, De-Ming Wu, Qi-Yong Zhang, and Xiao-Qin Chen
- Subjects
0301 basic medicine ,MAPK/ERK pathway ,Cell growth ,Chemistry ,Small hairpin RNA ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,PKMYT1 ,Oncology ,Apoptosis ,Cell culture ,030220 oncology & carcinogenesis ,Cancer research ,Gene silencing ,Pharmacology (medical) ,Protein kinase A - Abstract
Background Abnormal expression of protein kinase membrane associated tyrosine/threonine 1 (PKMYT1) is closely associated with multiple types of cancers. In the present study, we examined the roles of PKMYT1 in gastric cancer (GC) progression. Methods We examined the expression status of PKMYT1 in GC tissues and cell lines. Meanwhile, short hairpin RNA (shRNA) was used to inhibit the endogenous expression of PKMYT1 in GC cells. Then we analyzed the effect of PKMYT1 on the malignant biological behavior of GC cells by in vitro and in vivo experiments. Results The findings showed high PKMYT1 expressions in GC tissues as well as a positive correlation between PKMYT1 expression and prognosis of patients with GC. Additional findings also revealed that PKMYT1 silencing significantly enhanced apoptosis and inhibited GC cell proliferation. In vivo, the silence of PKMYT1 inhibits tumor growth. Further analysis showed that the increase in PKMYT1 expressions led to malignant biological behavior through activation of the MAPK signaling pathway. Conclusion Our data suggested that PKMYT1 promotes cell proliferation and apoptosis resistance in GC cells by activating the MAPK signaling pathway, making it a potential therapeutic target for GC.
- Published
- 2020
- Full Text
- View/download PDF
43. Bactericidal effects of in vitro 405 nm, 530 nm and 650 nm laser irradiation on methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa and Mycobacterium fortuitum
- Author
-
Kim Soon Lee, Aemen Ali Kudayr Al-Shammary, Shao Qin Chen, Noor Areefa Ardella Mohd Ma’amor, and Khayriyyah Mohd Hanafiah
- Subjects
biology ,medicine.drug_class ,Pseudomonas aeruginosa ,Chemistry ,Antibiotic sensitivity ,Antibiotics ,biology.organism_classification ,medicine.disease_cause ,Cell morphology ,Antimicrobial ,Microbiology ,Staphylococcus aureus ,medicine ,Mycobacterium fortuitum ,Bacteria - Abstract
Laser irradiation (LI) is an emerging antimicrobial strategy that may reduce public health reliance on antibiotics but previous studies reported results based on one wavelength-duration LI, typically on one bacterial species using solid culture. This study aimed to evaluate the effect of increasing duration of 405 nm, 532 nm and 650 nm LI on methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa and Mycobacterium fortuitum in liquid culture. Bacterial cultures of 1000 CFU/ml irradiated with 405 nm, 532 nm and 650 nm (200 mW) laser at 1, 2, 5 and 10 min were subcultured on nutrient agar; colony counts pre/post-LI were recorded and survival calculated. Antimicrobial sensitivity and cell morphology pre/post-LI were compared using scanning electron microscopy (SEM) and disc diffusion, respectively. The 405 nm (blue) LI had the highest bactericidal effect (0–6% survival) on all test bacteria compared to 532 nm (green) (12–49% survival) and 650 nm (red) (33–94% survival) LI. An inverse relationship between LI duration and survival was observed, except in 650 nm LI of P. aeruginosa, whereby survival increased with increasing duration. No change in antibiotic sensitivity was observed for subcultured bacterial colonies post-10 min LI. Although SEM micrographs of bacteria 10 minutes post-405 nm LI showed appreciable cell morphological changes, no significant cellular damage was observed. These encouraging results confirm bactericidal effects of 405 nm LI on bacteria such as P. aeruginosa and further expand findings on 532 nm and 650 nm LI on bacterial survival, highlighting the potential of LI as novel antimicrobial strategies on opportunistic pathogens such as MRSA, P. aeruginosa and M. fortuitum.
- Published
- 2020
- Full Text
- View/download PDF
44. New Pyridine-Bridged Ferrocene–Rhodamine Receptor for the Multifeature Detection of Hg2+ in Water and Living Cells
- Author
-
Mei Zhao, Yu-Shuang Guo, Yu-Qin Chen, Qiong Wang, and Dian-Shun Guo
- Subjects
Detection limit ,Chemistry ,Chromogenic ,General Chemical Engineering ,General Chemistry ,Conjugated system ,Electrochemistry ,Fluorescence ,Combinatorial chemistry ,Rhodamine ,chemistry.chemical_compound ,Ferrocene ,Pyridine ,QD1-999 - Abstract
A challenge in the design of optical and redox-active receptors is how to combine a specific recognition center with an efficient responsive system to facilely achieve multifeature detection in biological and environmental analyses. Herein, a novel ferrocene-rhodamine receptor conjugated with a pyridine bridge was designed and synthesized. This receptor can sensitively sense Hg2+ in aqueous media via chromogenic, fluorogenic, and electrochemical multisignal outputs with a low detection limit and fast response time. Moreover, it can be qualified as a fluorescent probe for effectively monitoring Hg2+ in living cells. A plausible recognition mode was proposed and rationalized with theoretical calculations.
- Published
- 2020
45. Ciclopirox activates PERK-dependent endoplasmic reticulum stress to drive cell death in colorectal cancer
- Author
-
Liyi Li, Bin Lu, Changliang Shan, Ningning Zhou, Shouyong Mo, Yidan Zhou, Jianjun Qi, Yao Deng, Qin Chen, and Ting Chen
- Subjects
0301 basic medicine ,Cancer Research ,Programmed cell death ,Cell cycle checkpoint ,Chemistry ,Cell growth ,Kinase ,lcsh:Cytology ,Endoplasmic reticulum ,Immunology ,Apoptosis ,Energy metabolism ,Cell Biology ,Colorectal cancer ,Article ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,030104 developmental biology ,0302 clinical medicine ,030220 oncology & carcinogenesis ,Unfolded protein response ,Cancer research ,lcsh:QH573-671 ,Protein kinase A - Abstract
Ciclopirox (CPX) modulates multiple cellular pathways involved in the growth of a variety of tumor cell types. However, the effects of CPX on colorectal cancer (CRC) and the underlying mechanisms for its antitumor activity remain unclear. Herein, we report that CPX exhibited strong antitumorigenic properties in CRC by inducing cell cycle arrest, repressing cell migration, and invasion by affecting N-cadherin, Snail, E-cadherin, MMP-2, and MMP-9 expression, and disruption of cellular bioenergetics contributed to CPX-associated inhibition of cell growth, migration, and invasion. Interestingly, CPX-induced reactive oxygen species (ROS) production and impaired mitochondrial respiration, whereas the capacity of glycolysis was increased. CPX (20 mg/kg, intraperitoneally) substantially inhibited CRC xenograft growth in vivo. Mechanistic studies revealed that the antitumor activity of CPX relies on apoptosis induced by ROS-mediated endoplasmic reticulum (ER) stress in both 5-FU-sensitive and -resistant CRC cells. Our data reveal a novel mechanism for CPX through the disruption of cellular bioenergetics and activating protein kinase RNA-like endoplasmic reticulum kinase (PERK)-dependent ER stress to drive cell death and overcome drug resistance in CRC, indicating that CPX could potentially be a novel chemotherapeutic for the treatment of CRC.
- Published
- 2020
- Full Text
- View/download PDF
46. Mitochondria-targeted artesunate conjugated cyclometalated iridium(<scp>iii</scp>) complexes as potent anti-HepG2 hepatocellular carcinoma agents
- Author
-
Rong-Tao Li, Xuan-Qin Chen, Ning Jiang, Bi-Chun Chen, Zong-Wan Mao, Wan Peng, and Rui-Rong Ye
- Subjects
Carcinoma, Hepatocellular ,Biophysics ,Artesunate ,Antineoplastic Agents ,Apoptosis ,Iridium ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Biomaterials ,chemistry.chemical_compound ,Bipyridine ,Coordination Complexes ,In vivo ,medicine ,Humans ,Cytotoxicity ,010405 organic chemistry ,Chemistry ,Liver Neoplasms ,Metals and Alloys ,Hep G2 Cells ,Cell cycle ,medicine.disease ,0104 chemical sciences ,Chemistry (miscellaneous) ,Cell culture ,Hepatocellular carcinoma ,Cancer research - Abstract
Hepatocellular carcinoma (HCC) poses a serious threat to people’s health worldwide. Artesunate (ART), one of the classical antimalarial drugs, has recently been shown to exert significant cytotoxicity in various cancers, but its bioavailability is low. Cyclometalated iridium(iii) complexes have emerged as a promising class of anticancer therapeutic agents. Herein, through conjugation of two of them, three novel Ir(iii)–ART conjugates, [Ir(C–N)2(bpy-ART)](PF6) (bpy = 2,2′-bipyridine, C–N = 2-phenylpyridine (ppy, Ir-ART-1), 2-(2-thienyl)pyridine (thpy, Ir-ART-2), and 2-(2,4-difluorophenyl)pyridine (dfppy, Ir-ART-3)) have been synthesized, and their potential as anti-HCC agents was evaluated. We demonstrate that Ir-ART-1–3 display higher cytotoxicity against HCC cell lines than normal liver cells, and they can especially locate to mitochondria of HepG2 cells and induce a series of mitochondria-mediated apoptosis events. Moreover, Ir-ART-1–3 can regulate the cell cycle and inhibit metastasis of HepG2 cells. Finally, in vivo antitumor evaluation also demonstrates the inhibitory activity of Ir-ART-1 on tumor growth. Taken together, these Ir(iii)–ART conjugates have the potential to become drug candidates for future anti-HCC treatments.
- Published
- 2020
- Full Text
- View/download PDF
47. Differential metabolic markers associated with primary open-angle glaucoma and cataract in human aqueous humor
- Author
-
Hua Zhong, Xu Zha, Yijin Tao, Chaofu Ke, Yuan-Ping Zhang, Qin Chen, and Chen-Wei Pan
- Subjects
Male ,Open angle glaucoma ,genetic structures ,Epidemiology ,Metabolite ,Glaucoma ,Aqueous humor ,Bioinformatics ,Cataract ,Aqueous Humor ,chemistry.chemical_compound ,Metabolomics ,lcsh:Ophthalmology ,Medicine ,Humans ,KEGG ,Open-angle glaucoma ,Intraocular Pressure ,Aged ,Primary (chemistry) ,business.industry ,General Medicine ,medicine.disease ,eye diseases ,Ophthalmology ,chemistry ,ROC Curve ,lcsh:RE1-994 ,Case-Control Studies ,Metabolic markers ,Female ,sense organs ,business ,Biomarkers ,Glaucoma, Open-Angle ,Research Article ,Follow-Up Studies - Abstract
Background We aimed to identify metabolic biomarkers and investigate the metabolic alterations in relation to primary open-angle glaucoma (POAG) and cataract in human aqueous humor. Methods Sixteen POAG patients undergoing surgical treatments and 24 patients undergoing cataract surgeries were included in this case-control study. We performed the metabolomic analysis of aqueous humor samples using a non-targeted gas chromatography coupled to time-of-flight mass spectrometer. The area under the receiver operating characteristic curve (AUC) was computed to assess the discrimination capacities of each metabolite marker. Databases including the Kyoto Encyclopedia of Genes and Genomes (KEGG) and MetaboAnalyst were utilized to search for the potential pathways of metabolites. Results Aqueous humor metabolomic profiles could well distinguish POAG from controls. Fourteen metabolic biomarkers were identified as potential aqueous humor biomarkers for POAG, yielding AUC values from 0.62 to 0.86. In pathway analysis, Biotin metabolism was highly impacted, implying that these metabolic markers play important roles in the regulation of this pathway. Conclusions This study identified valuable metabolic biomarkers and pathways that may facilitate an improved understanding of the POAG pathogenesis. The finding holds translational value in the development of new therapeutic measures for POAG.
- Published
- 2020
- Full Text
- View/download PDF
48. CD28: A New Drug Target for Immune Disease
- Author
-
Qin Chen, Bing Niu, and Sijing Xia
- Subjects
0301 basic medicine ,B7 Antigens ,T-Lymphocytes ,T cell ,Clinical Biochemistry ,Cell ,Antigen-Presenting Cells ,chemical and pharmacologic phenomena ,Disease ,Biology ,Lymphocyte Activation ,Antibodies ,03 medical and health sciences ,0302 clinical medicine ,Immune system ,CD28 Antigens ,Drug Discovery ,medicine ,Animals ,Humans ,Receptor ,Pharmacology ,chemistry.chemical_classification ,CD28 ,Cell biology ,030104 developmental biology ,medicine.anatomical_structure ,Immune System Diseases ,chemistry ,CTLA-4 ,030220 oncology & carcinogenesis ,Molecular Medicine ,Glycoprotein - Abstract
Background: CD28, a cell surface glycoprotein receptor, predominantly expressed on activated T cells, belongs to the Ig superfamily and provides a critical co-stimulatory signal. CTLA-4 has sequence homology to CD28, and is expressed on T cells after activation. It provides an inhibition signal coordinated with CD28 to regulate T cell activation. Both of them regulate T cell proliferation and differentiation and play an important role in the immune response pathway in vivo. Objective: We studied the special role of different structural sites of CD28 in producing costimulatory signals. Methods: We reviewed the relevant literature, mainly regarding the structure of CD28 to clarify its biological function, and its role in the immune response. Results: In recent years, increasingly attention has been paid to CD28, which is considered as a key therapeutic target for many modern diseases, especially some immune diseases. Conclusion: In this paper, we mainly introduce the structure of CD28 and its related biological functions, as well as the application of costimulatory pathways targeting CD28 in disease treatment.
- Published
- 2020
- Full Text
- View/download PDF
49. Four new quinolizidine alkaloids from the flowers of Sophora viciifolia
- Author
-
Xuan-Qin Chen, Dan Liu, Rong-Tao Li, Dan-Dan Gao, Hong-Mei Li, and Zhi-Jun Zhang
- Subjects
Quinolizidine ,Traditional medicine ,010405 organic chemistry ,Alkaloid ,Plant Science ,Biology ,Sophora viciifolia ,01 natural sciences ,Biochemistry ,0104 chemical sciences ,010404 medicinal & biomolecular chemistry ,chemistry.chemical_compound ,chemistry ,Agronomy and Crop Science ,Biotechnology - Abstract
Four new quinolizidine alkaloids, including three matrine-type alkaloids, 8α-hydroxysophocarpine (1), 13β-hydroxyoxymatrine (2), 9α-acetoxymatrine (3), and one sparteine-type alkaloid, 14β-hydroxylupanine (4), together with four known ones, were isolated from the flowers of Sophora viciifolia. Their structures were elucidated by extensive spectroscopic methods including 1D-, 2D-NMR, and HR-ESI-MS. All of the isolates were evaluated for their anti-inflammatory and anti-influenza virus activities. Unfortunately, none of them were active towards these assays.
- Published
- 2020
- Full Text
- View/download PDF
50. Palladium‐Catalyzed Coupling of Propargylic Alcohols with Boronic Acids under Ambient Conditions
- Author
-
Qin Chen, Shengming Ma, Hui Qian, and Anni Qin
- Subjects
Coupling (electronics) ,Chemistry ,Polymer chemistry ,chemistry.chemical_element ,General Chemistry ,Palladium ,Catalysis - Published
- 2020
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.