Biodegradable cross-linked poly(L-lactide-co-e-caprolactone) networks for ureteral stent formed by gamma irradiation under vacuum

Xiliang Liu,Song Liu,Youkun Fan,Jin Qi,Xin Wang,Wei Bai,Dongliang Chen,Chengdong Xiong,Lifang Zhang 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.104 No.-

The poly(L-lactide-co-e-caprolactone) (PLCL) ureteral stent creeps and loses shape stability, increasingthe risk of stent tube dislocation. The rubbery biodegradable cross-linked PLCL networks were preparedthrough gamma irradiation under vacuum in the presence of trimethylolpropane triacrylate (TMPTA),pentaerythritol tetraacrylate (PET4A), and pentaerythritol triacrylate (PETA). At a standard sterilizationdose of 25 kGy, the gel content and network density of PLCL networks increased with increasingcrosslinking agent content (1, 3, 5, 7 wt%), and crosslinking efficiency decreased in the order ofPETA > PET4A > TMPTA. The average molecular weight (Mc ) between two crosslinks ranged from 2000to 105 g/mol. To perform the beneficial semi-interpenetrated polymer network and characterized bythe principle, the networks were processed in several doses (25, 50, 75, 100, and 125 kGy). In place ofthe Charlesby-Pinner equation, the irradiation cross-linking followed the Chen-Liu-Tang equation. ThePLCL network with 7 wt% PETA had a gel fraction of 83%, tensile strength of 34.7 MPa, and tensile setvalue as low as 5%. Furthermore, degradation in vitro was slowed down. Thus, PLCL networks with appropriateelasticity and flexibility, inherent biodegradability, and excellent biocompatibility can provide apromising alternative method for soft tissue repair engineering, such as ureteral stents.

Serum miR-19a Predicts Resistance to FOLFOX Chemotherapy in Advanced Colorectal Cancer Cases

Chen, Qi,Xia, Hong-Wei,Ge, Xiao-Jun,Zhang, Yu-Chen,Tang, Qiu-Lin,Bi, Feng Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.12

Background: Colorectal cancer is the fourth most common cancer worldwide and the second leading cause of cancer-related death. FOLFOX is the most common regimen used in the first-line chemotherapy in advanced colorectal cancer, but only half of the patients respond to this regimen and we have almost no clue in predicting resistance in such first-line application. Methods: To explore the potential molecular biomarkers predicting the resistance of FOLFOX regimen as the first-line treatment in advanced colorectal cancer, we screened microRNAs in serum samples from drug-responsive and drug-resistant patients by microarrays. Then differential microRNA expression was further validated in an independent population by reverse transcription and quantitative real-time PCR. Results: 62 microRNAs expressing differentially with fold-change >2 were screened out by microarray analysis. Among them, 5 (miR-221, miR-222, miR-122, miR-19a, miR-144) were chosen for further validation in an independent population (N=72). Our results indicated serum miR-19a to be significantly up-regulated in resistance-phase serum (p=0.009). The ROC curve analysis showed that the sensitivity of serum miR-19a to discriminate the resistant patients from the response ones was 66.7%, and the specificity was 63.9% when the AUC was 0.679. We additionally observed serum miR-19a had a complementary value for cancer embryonic antigen (CEA). Stratified analysis further revealed that serum miR-19a predicted both intrinsic and acquired drug resistance. Conclusions: Our findings confirmed aberrant expression of serum miR-19a in FOLFOX chemotherapy resistance patients, suggesting serum miR-19a could be a potential molecular biomarker for predicting and monitoring resistance to first-line FOLFOX chemotherapy regimens in advanced colorectal cancer patients.

Slow Release Fertilizer Decreases Leaching Loss of Nitrogen in Sand-based Root Zone

Chen Wei-Feng(첸웨이펭),Wang-Wei(왕웨이),Qi Ying-Jie(퀴잉제) 한국잡초학회·한국잔디학회 2007 Weed & Turfgrass Science Vol.21 No.2

축구장의 식재지반이 모래로 조성될 경우 낮은 보비력과 높은 용탈율로 인해 시비관리의 조정이 필요하다. 본 실험의 목적은 PVC관을 이용한 경기장 유사모형 실험구에서 캔터키 블루그래스에 있어서 완효성비료의 생육 효과를 비교 실험하였다. 잔디의 색깔, 균일도, 생육, 지상부 생체량과배출수의 질산의 유출량을 몇가지 다른 생육상과 네번의 유사 강우 시험 시 행하였다. 실험 결과 요소의 성분 유출량이 가장 높았고 공시 완효성비료는 가장 낮았다. 이 완효성 비료는 다른 공사 잔디비료에 비해 14일간, 요소보다는 28일간 잔디의 품질 변에서 비효가 지속되었다. 또한 이 완효성비료는 잔디의 웃자람과 잔디깎기에 소요되는 시간을 줄일 수 있었다. 질산태 질소의 유출에 았어서도잔디의 조성 초반기에 50% 정도를 감소 시켰다. When a football field is constructed using sand medium, the fertilizer management has to be adjusted because of the low nutrient holding capacity and higher leaching rate. The objective of this study was to test the effects of slow release fertilizers on Kentucky bluegrass (Poa pratensis L.) growth in simulated sport field rootzones with PVC pipe pots. Data of turf grass color, uniformity, growth rate, biomass above ground, and the nitrate content in the leaching solution was collected at different growing stages and during four simulated rain fall periods. The result showed that the nutrient release rate of urea was the highest and that of controlled release nitrogen fertilizer was the lowest. Effects of the controlled release nitrogen fertilizer lasted 14 days more than other lawn fertilizers and 28 days longer than regular urea with acceptable quality levels of turf. The slow release fertilizer also restrained excessive growth of the grass, reduced the times of mowing. Slow release fertilizer used in this study reduced NO₃-N leaching by almost 50% at the beginning of turf establishment.

AtHAP3b Plays a Crucial Role in the Regulation of Flowering Time in Arabidopsis during Osmotic Stress

Chen, Nai-Zhi,Zhang, Xiu-Qing,Wei, Peng-Cheng,Chen, Qi-Jun,Ren, Fei,Chen, Jia,Wang, Xue-Chen Korean Society for Biochemistry and Molecular Biol 2007 Journal of biochemistry and molecular biology Vol.40 No.6

The HAP complex has been found in many eukaryotic organisms. HAP recognizes the CCAAT box present in the promoters of 30% of all eukaryotic genes. The HAP complex consists of three subunits - HAP2, HAP3 and HAP5. In this paper, we report the biological function of the AtHAP3b gene that encodes one of the HAP3 subunits in Arabidopsis. Compared with wild-type plants, hap3b-1 and hap3b-2 mutants exhibited a delayed flowering time under long-day photoperiod conditions. Moreover, the transcription levels of FT were substantially lower in the mutants than in the wild-type plants. These results imply that AtHAP3b may function in the control of flowering time by regulating the expression of FT in Arabidopsis. In a subsequent study, AtHAP3b was found to be induced by osmotic stress. Under osmotic stress conditions, the hap3b- 1 and hap3b-2 mutants flowered considerably later than the wild-type plants. These results suggest that the AtHAP3b gene plays more important roles in the control of flowering under osmotic stress in Arabidopsis.

Vasodilation Effect of 2-benzyl-5-hydroxy-6-methoxy-3, 4-dihydroisoquinolin- 1-one

Wei-Qi,Yong-Xiao Cao,Zhi-Zheng Xiong,Ting-Ting Chen,Xiao-Yan Gao,Hang Yu,San-Qi Zhang 대한약학회 2012 Archives of Pharmacal Research Vol.35 No.8

A 2-Benzyl-5-hydroxy-6-methoxy-3, 4-dihydroisoquinolin-1-one (ZC2) is a newly synthesized isoquinolinone compound. Its effect on vasodilation was evaluated in the present study. Isometric tension of rat artery rings was recorded by a sensitive myography system in vitro. The results showed that ZC2 relaxed rat mesenteric arteries pre-contracted by KCl, phenylephrine and 9, 11- dideoxy- 11α, 9α-epoxymethano-prostaglandin F2α (U46619), and abdominal aorta pre-contracted by KCl in a concentration-dependent manner. The ZC2-induced vasodilation was not affected by an endothelium denudation. ZC2 rightwards shifted the concentration-contraction curves, induced by KCl, phenylephrine, and 5-hydroxytryptamine (5-HT) in a non-parallel manner, which suggests that the vasodilation effects are most likely via voltage-dependent calcium channel (VDCC) and receptor-operated calcium channel (ROCC). Moreover, in Ca2+-free medium, ZC2 concentration-dependently depressed the vasoconstrictions induced by phenylephrine and CaCl2, and decreased a contractile response induced by caffeine, which indicates a role of extracellular Ca2+ influx inhibition through VDCC and ROCC, and intracellular Ca2+ release from Ca2+ store via the ryanodine receptors. Glibenclamide did not affect the vasodilation induced by ZC2, suggesting that ATP sensitive potassium channel is not involved in the vasodilation. The results indicate that ZC2 induces vasodilation by inhibiting the VDCC and ROCC, and receptormediated Ca2+ influx and release. The inhibition of intracellular Ca2+ release may be mediated via the ryanodine receptors.

Inhibition of microRNA-214 promotes epithelial mesenchymal transition process and induces interstitial cystitis in postmenopausal women by upregulating Mfn2

Jian-Wei Lv,Wei Wen,Chen Jiang,Qi-Bo Fu,Yin-Jun Gu,Ting-Ting Lv,Zhen-Dong Li,Wei Xue 생화학분자생물학회 2017 Experimental and molecular medicine Vol.49 No.-

Our study aims to investigate the roles that microRNA-214 (miR-214) plays in the epithelial mesenchymal transition (EMT) process and the development of interstitial cystitis (IC) in postmenopausal women by targeting Mitofusin 2 (Mfn2). IC bladder tissues and adjacent normal bladder tissues were collected from postmenopausal women. Immunohistochemistry (IHC) staining was conducted. The target relationship between miR-214 and Mfn2 was determined by a dual luciferase reporter gene assay. Adipose-derived mesenchymal stem cells (ADMSCs) were extracted from postmenopausal rats and assigned to the blank, mimics, miR-214 inhibitors, mimics negative control (NC), inhibitors NC, Mfn2 siRNA, miR-214 inhibitors and Mfn2 siRNA groups. Exosomes secreted by transfected ADMSCs were instilled into the bladders of postmenopausal rats. The expression of miR-214 and Mfn2 mRNA and EMT markers was assessed by qRT-PCR and western blotting. It was confirmed that Mfn2 was the target gene of miR-214 in IC. Compared with the normal bladder tissues, miR-214 decreased, but Mfn2 increased in IC bladder tissues. Compared with the blank group, the expression of miR-214 and the expression levels of N-cadherin, Fibronectin, Twist1, Snail and Vimentin mRNA and protein increased, whereas the expression levels of Mfn2, E-cadherin and ZO-1 mRNA and protein decreased in the miR-214 mimics and Mfn2 groups. The expression of MiR-214 and the expression levels of N-cadherin, Fibronectin, Twist1, Snail and Vimentin mRNA and protein decreased, whereas the expression levels of Mfn2, E-cadherin and ZO-1 mRNA and protein increased in the miR-214 inhibitors group. Our findings indicate that the inhibition of miR-214 promotes the EMT process and contributes to bladder wall fibrosis by up-regulating Mfn2, thus leading to the occurrence of IC in postmenopausal women.

Design and Analysis of an Active Balancing Mechanism for a Vertical Axis Washing Machine

Hai-Wei Chen,Xun-Ting Yuan,Zhen Sun,Qiu-Qi Mou,Ming Xiong,Wei-Hua Wang 한국정밀공학회 2022 International Journal of Precision Engineering and Vol.23 No.7

In recent years, active balancing of washing machines has drawn much attention from manufactures. This paper proposes a novel active balancing mechanism for vibration suppression of a vertical axis washing machine which employs water for counteracting the unbalanced laundry. At first, a novel structure with two balancing planes sharing only one set of nozzles for injecting water is designed and the balancing capability of the structure is analyzed. Then, a dynamic model of the active balancing system is constructed. Vibration characteristics of the system including changes of the vibration amplitude and phase angle under different influences are studied. After that, a strategy for identifying the imbalance is proposed and an active control method is designed. At last, a washing machine armed with the active mechanism is manufactured. Both a fixed eccentric block and a pile of randomly distributed laundry are used to test the balancing effect. The results show that lateral vibrations of the washer can be greatly reduced by the active mechanism. Due to the simplicity of the structure and the satisfactory balancing effect, the mechanism proposed has a big potential to be employed in future washing machines.

Fabrication and Characterization of Vertically Aligned ZnO Nanorod Arrays via Inverted Monolayer Colloidal Crystals Mask

Cheng Chen,Taotao Ding,Zhiqiang Qi,Wei Zhang,Jun Zhang,Juan Xu,Jingwen Chen,Jiangnan Dai,Changqing Chen 대한금속·재료학회 2018 ELECTRONIC MATERIALS LETTERS Vol.14 No.4

The periodically ordered ZnO nanorod (NR) arrays have been successfully synthesized via a hydrothermal approach on thesilicon substrates by templating of the TiO2ring deriving from the polystyrene (PS) nanosphere monolayer colloidal crystals(MCC). With the inverted MCC mask, sol–gel-derived ZnO seeds could serve as the periodic nucleation positions for thesite-specific growth of ZnO NRs. The large-scale patterned arrays of single ZnO NR with good side-orientation can be readilyproduced. According to the experimental results, the as-integrated ZnO NR arrays showed an excellent crystal quality andoptical property, very suitable for optoelectronic applications such as stimulated emitters and ZnO photonic crystal devices.

AtHAP3b Plays a Crucial Role in the Regulation of Flowering Time in Arabidopsis during Osmotic Stress

Nai Zhi Chen,Xiu Qing Zhang,Peng Cheng Wei,Qi Jun Chen,Fei Ren,Jia Chen,Xue Chen Wang 한국생화학분자생물학회 (구 한국생화학회) 2007 BMB Reports Vol.40 No.6

Efficacy and Safety of Intravenous Urapidil for Older Hypertensive Patients with Acute Heart Failure: A Multicenter Randomized Controlled Trial

Wei Yang,Qi Hua,Yu-Jie Zhou,Yan Fu,Jian Qin,Shu Qin,Xiao-Min Chen,Jin-Cheng Guo,De-Zhao Wang,Hong Zhan,Jing Li,Jing-Yu He 연세대학교의과대학 2017 Yonsei medical journal Vol.58 No.1

Purpose: Urapidil is putatively effective for patients with hypertension and acute heart failure, although randomized controlled trials thereon are lacking. We investigated the efficacy and safety of intravenous urapidil relative to that of nitroglycerin in older patients with hypertension and heart failure in a randomized controlled trial. Materials and Methods: Patients (>60 y) with hypertension and heart failure were randomly assigned to receive intravenous urapidil (n=89) or nitroglycerin (n=91) for 7 days. Hemodynamic parameters, cardiac function, and safety outcomes were compared. Results: Patients in the urapidil group had significantly lower mean systolic blood pressure (110.1±6.5 mm Hg) than those given nitroglycerin (126.4±8.1 mm Hg, p=0.022), without changes in heart rate. Urapidil was associated with improved cardiac function as reflected by lower N terminal-pro B type natriuretic peptide after 7 days (3311.4±546.1 ng/mL vs. 4879.1±325.7 ng/mL, p=0.027) and improved left ventricular ejection fraction (62.2±3.4% vs. 51.0±2.4%, p=0.032). Patients given urapidil had fewer associatedadverse events, specifically headache (p=0.025) and tachycardia (p=0.004). The one-month rehospitalization and all-cause mortality rates were similar. Conclusion: Intravenous administration of urapidil, compared with nitroglycerin, was associated with better control of blood pressure and preserved cardiac function, as well as fewer adverse events, for elderly patients with hypertension and acute heart failure.