检索结果-南通市图书馆

Enhanced delivery of a low dose of aducanumab via FUS in 5×FAD mice,an AD model

在线全文

学校读者我要写书评

暂无评论

Translational Neurodegeneration 2022年第1期11卷 31-45页

作者： Chanho Kong Eun-Jeong yang Jaewoo Shin Junwon Park Si-Hyun Kim Seong-Wook Park won seok Chang Chang-Han Lee Hyunju Kim Hye-Sun Kim Jin Woo Chang Department of Neurosurgery Yonsei University College of Medicine50 Yonsei-RoSeodaemun-GuSeoulRepublic of Korea Department of Pharmacology College of MedicineSeoul National University103 DaehakroJongro-GuSeoulRepublic of Korea Neuroscience Research Center College of MedicineSeoul National University103 DaehakroJongro-GuSeoulRepublic of Korea Department of Biomedical Sciences College of MedicineSeoul National University103 DaehakroJongro-GuSeoulRepublic of Korea Bundang Hospital Seoul National University College of MedicineBundang-GuSungnamRepublic of Korea.

Background:Aducanumab(Adu),which is a human IgG1 monoclonal antibody that targets oligomer and fibril forms of beta-amyloid,has been reported to reduce amyloid pathology and improve impaired cognition after administration of a high dose(10 mg/kg)of the drug in Alzheimer’s disease(AD)clinical trials.The purpose of this study was to investigate the effects of a lower dose of Adu(3 mg/kg)with enhanced delivery via focused ultrasound(FUS)in an AD mouse model.Methods:The FUS with microbubbles opened the blood-brain barrier(BBB)of the hippocampus for the delivery of Adu.The combined therapy of FUS and Adu was performed three times in total and each treatment was performed biweekly.Y-maze test,Brdu labeling,and immunohistochemical experimental methods were employed in this study.In addition,RNA sequencing and ingenuity pathway analysis were employed to investigate gene expression profiles in the hippocampi of experimental animals.Results:The FUS-mediated BBB opening markedly increased the delivery of Adu into the brain by approximately 8.1 times in the brains.The combined treatment induced significantly less cognitive decline and decreased the level of amyloid plaques in the hippocampi of the 5×FAD mice compared with Adu or FUS alone.Combined treatment with FUS and Adu activated phagocytic microglia and increased the number of astrocytes associated with amyloid plaques in the hippocampi of 5×FAD mice.Furthermore,RNA sequencing identified that 4 enriched canonical pathways including phagosome formation,neuroinflammation signaling,CREB signaling and reelin signaling were altered in the hippocami of 5×FAD mice receiving the combined treatment.Conclusion:In conclusion,the enhanced delivery of a low dose of Adu(3 mg/kg)via FUS decreases amyloid deposits and attenuates cognitive function deficits.FUS-mediated BBB opening increases adult hippocampal neurogenesis as well as drug delivery.We present an AD treatment strategy through the synergistic effect of the combined therapy of FUS and Adu.

关键词： Aducanumab Alzheimer’s disease Focused ultrasound Transcriptome profiling

Body-centered-cubic martensite and the role on room-temperature tensile properties in Si-added SiVCrMnFeCo high-entropy alloys

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2021年第17期76卷 222-230页

作者： Yong Hee Jo Junha yang won-Mi Choi Kyung-Yeon Doh Donghwa Lee Hyoung Seop Kim Byeong-Joo Lee seok Su Sohn Sunghak Lee Center for High Entropy Alloys Pohang University of Science and TechnologyPohang 37673South Korea Department of Materials Science and Engineering Division of Advanced Materials SciencePohang University of Science and TechnologyPohang 37673South Korea Graduate Institute of Ferrous Technology Pohang University of Science and TechnologyPohang 37673South Korea Department of Materials Science and Engineering Korea UniversitySeoul 02841South Korea

We present a new class of metastable high-entropy alloys(HEAs),triggering deformation-induced martensitic transformation(DIMT)from face-centered-cubic(FCC)to body-centered-cubic(BCC),i.e.,BCC-DIMT.Through the ab-initio calculation based on 1 st order axial interaction model and combined with the Gibbs free energy calculation,the addition of Si is considered as a critical element which enables to reduce the intrinsic stacking fault energy(ISFE)in Si_xV_((9-x))Cr_(10)Mn_5 Fe_(46)Co_(30)(x=2,4,and 7 at.%)alloy system.The ISFE decreases from-30.4 to-35.5 mJ/m^(2)as the Si content increases from 2 to 7 at.%,which well corresponds to the reduced phase stability of FCC against HCP.The BCC-DIMT occurs in all the alloys via intermediate HCP martensite,and the HCP martensite provides nucleation sites of BCC martensite.Therefore,the transformation rate enhances as the Si content increases in an earlier deformation ra nge.However,the BCC-DIMT is also affected by the phase stability of FCC against BCC,and the stability is the highest at the Si content of 7 at.%.Thus,the 7Si alloy presents the moderate transformation rate in the later deformation range.Due to the well-controlled transformation rate and consequent strain-ha rdening rate,the 7Si alloy possesses the superior combination of strength and ductility beyond 1 GPa of tensile strength at room temperature.Our results suggest that the Si addition can be a favorable candidate in various metastable HEAs for the further property improvement.

关键词： High-entropy alloy(HEA) Deformation-induced martensitic transformation(DIMT) Phase stability Stacking fault energy(SFE)

Colonic mucormycosis presented with ischemic colitis in a liver transplant recipient

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2013年第22期19卷 3508-3511页

作者： Gi won Do seok won Jung Jae-Bum Jun Jae Hee Seo yang won Nah Department of Internal Medicine University of Ulsan College of Medicine Ulsan University Hospital Dong-gu Ulsan 682-813 South Korea Department of Pathology University of Ulsan College of Medicine Ulsan University Hospital Dong-gu Ulsan 682-813 South Korea Division of Hepatobiliary Surgery and Liver Transplantation Department of Surgery University of Ulsan College of Medicine Ulsan University Hospital Dong-gu Ulsan 682-813 South Korea

Mucormycosis is an uncommon opportunistic fungal infection with high mortality in liver transplant recipients. Mucormycosis of the gastrointestinal tract can manifest with features similar to ischemic colitis. Typically signs and symptoms of non-gangrenous ischemic colitis resolve spontaneously within 24-48 h. On the other hand, the clinical course of the mucormycosis is commonly fulminant. We encountered a case of invasive fungal colitis presenting with abdominal pain and hematochezia in a liver transplant recipient. Endoscopic examination showed multiple shallow ulcerations and edema with mucosal friabilities on the sigmoid and distal descending colon, which was consistent with ischemic colitis. However, the histological examination obtained from endoscopic biopsies showed fungal hyphae withsurrounding inflammatory cells and mucosal necrosis. The patient was successfully managed with antifungal agent without surgical treatment. Thus, early diagnosis and treatment is essential for improving the prognosis of invasive fungal infection after liver transplantation.

关键词： Mucormycosis Liver transplantation Colon Ischemia

The Effect of the Variation of the Downstream Region Distance and Butterfly Valve Angle on Flow Characteristics in a 90 Degree Bended Elbow

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Modern Mechanical Engineering 2014年第3期4卷 133-143页

作者： Se Youl won Jae Gon Lee Jun seok yang Central Research Institute Korea Hydro & Nuclear Power Co. Ltd. Daejeon Korea

This study presents the numerical evaluation about the impact of flow disturbance near the intrados and extrados regions of the 90 degree bended elbow using CFX for several practical cases where the 90 degree bended upward elbow is located in a proximity to the butterfly valve and the butterfly valve open angle is changed. For the change of a butterfly valve open angle from 60% to 100% and the increase of the distance between a valve and a 90 degree bended elbow, the effect of FAC (Flow-Accelerated Corrosion) in the 90 degree bended elbow may be neglected because the value and distribution of the velocity and shear stress is rapidly decreased comparing with the present status installed in an industry, and the data of 100% valve open (Case 3) and L/D ≈ 5 (Case 4) are very good agreement comparing with the reference data, L/D ≈ 8 (Case 2). The reasons are that flow already maintains a fully developed condition and a steady state in spite of less distance than the reference case, L/D = 8. Therefore, smooth flow fields have approached at a 90 degree bended elbow. Then, the effect of shear stress and vortex is hardly investigated around the intrados area of 90 degree bended elbow.

关键词： Flow Disturbance Shear Stress 90 Degree Bended Elbow Butterfly Valve FAC

Crystal Facet Engineering of TiO_(2) Nanostructures for Enhancing Photoelectrochemical Water Splitting with BiVO_(4) Nanodots

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano-Micro Letters 2022年第3期14卷 201-215页

作者： Mi Gyoung Lee Jin Wook yang Hoonkee Park Cheon Woo Moon Dinsefa M.Andoshe Jongseong Park Chang‑Ki Moon Tae Hyung Lee Kyoung Soon Choi Woo seok Cheon Jang‑Joo Kim Ho won Jang Department of Materials Science and Engineering Research Institute of Advanced MaterialsSeoul National UniversitySeoul 08826Republic of Korea Department of Chemistry and Nanoscience Ewha Womans UniversitySeoul 03693Republic of Korea National Research Facilities and Equipment Center Korea Basic Science InstituteDaejeon 34133Republic of Korea Advanced Institute of Convergence Technology Seoul National UniversitySuwon 16229Republic of Korea

Although bismuth vanadate(BiVO4)has been promising as photoanode material for photoelectrochemical water splitting,its charge recombination issue by short charge diffusion length has led to various studies about heterostructure photoanodes.As a hole blocking layer of BiVO4,titanium dioxide(TiO_(2)) has been considered unsuitable because of its relatively positive valence band edge and low electrical conductivity.Herein,a crystal facet engineering of TiO_(2) nanostructures is proposed to control band structures for the hole blocking layer of BiVO4 nanodots.We design two types of TiO_(2) nanostructures,which are nanorods(NRs)and nanoflowers(NFs)with different(001)and(110)crystal facets,respectively,and fabricate BiVO4/TiO_(2) heterostructure photoanodes.The BiVO4/TiO_(2) NFs showed 4.8 times higher photocurrent density than the BiVO4/TiO_(2) NRs.Transient decay time analysis and time-resolved photoluminescence reveal the enhancement is attributed to the reduced charge recombination,which is originated from the formation of type II band alignment between BiVO4 nanodots and TiO_(2) NFs.This work provides not only new insights into the interplay between crystal facets and band structures but also important steps for the design of highly efficient photoelectrodes.

关键词： Crystal facet control Bismuth vanadate Titanium dioxide Heterojunction Water splitting

Facile synthesis of fully ordered L10-FePt nanoparticles with controlled Pt-shell thicknesses for electrocatalysis

在线全文

学校读者我要写书评

暂无评论

Nano Research 2017年第8期10卷 2866-2880页

作者： Yonghoon Hong Hee Jin Kim Daehee yang Gaehang Lee Ki Min Nam Myung-Hwa Jung Young-Min Kim Sang-II Choi won seok Seo Department of Chemistry Sogang University Seou104107 Republic of Korea Department of Chemistry and Green-Nano Materials Research Center Kyungpook National University Daegu 41566 Repubfic of Korea Korea Basic Science Institute and University of Science and Technology Daejeon 34133 Republic of Korea Department of Chemistry Mokpo National University Jeonnam 58554 Republic of Korea Department of Physics Sogang University Seoul 04107 Republic of Korea Center for Integrated Nanostructure Physics Institute for Basic Science (IBS) Suwon 16419 Repubfic of Korea Department of Energy Science Sungkyunkwan University (SKKU) Suwon 16419 Republic of Korea

We report a simple one-step approach for the synthesis of -4 nm uniform and fully L10-ordered face-centered tetragonal （fct） FePt nanoparticles （NPs） embedded in -60 nm MCM-41 （fct-FePt NPs@MCM-41）. We controlled the Pt-shell thickness of the fct-FePt NPs by treating the fct-FePt NPs@MCM-41 with acetic acid （HOAc） or hydrochloric acid （HC1） under sonicafion, thereby etching the surface Fe atoms of the NPs. The fct-FePt NPs deposited onto the carbon support （fct-FePt NP/C） were prepared by mixing the fct-FePt NPs@MCM-41 with carbon and subsequently removing the MCM-41 using NaOH. We also developed a facile method to synthesize acid-treated fct-FePt NP/C by using a HF solution for simultaneous surface-Fe etching and MCM-41 removal. We studied the effects of both surface-Fe etching and Pt-shell thickness on the electrocatalytic properties of fct-FePt NPs for the methanol oxidation reaction （MOR）. Compared with the non-treated fct-FePt NP/C catalyst, the HOAc-treated and HCl-treated catalysts exhibit up to 34% larger electrochemically active surface areas （ECASAs）; in addition, the HCl-treated fct-FePt NP （with -1.0 nm Pt shell）/C catalyst exhibits the highest specific activity. The HF-treated fct-FePt NP/C exhibits an ECASA almost 2 times larger than those of the other acid-treated fct-FePt NP/C catalysts and shows the highest mass activity （1,435 mA·mgPt^-1, 2.3 times higher than that of the commercial Pt/C catalyst） and stability among the catalysts tested. Our findings demonstrate that the surface-Fe etching for the generation of the Pt shell on fct-FePt NPs and the Pt-shell thickness can be factors for optimizing the electrocatalysis of the MOR.

关键词： FePt face centered tetragonal bimetallic methanol oxidation reaction electrocatalysts

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2022年第16期111卷 99-110页

作者： Vioni Dwi Sartika won seok Choi Gwanghyo Choi Jaewook Han Sung-Jin Chang won-seok Ko Blazej Grabowski Pyuck-Pa Choi Department of Materials Science and Engineering Korea Advanced Institute of Science and TechnologyDaejeon 34141Republic of Korea Gangwon Regional Division Korea Institute of Industrial TechnologyGangwon 25440Republic of Korea Division of Measurement and Analysis National Nanofab CenterDaejeon 34141Republic of Korea School of Materials Science and Engineering University of UlsanUlsan 44610Republic of Korea Institute for Materials Science University of StuttgartPfaffenwaldring 5570569 StuttgartGermany

We report laser cladding of pure titanium on a CoCrMo alloy using directed energy deposition.Using electron microscopy,the microstructural evolution upon varying the process parameters,especially laser power and powder feed rate,was investigated in relation to crack formation.Cladding layers showing dilution rates of more than 5%contained cracks due to the formation of the brittle Co_(2)Ti intermetallic phase.The observed cracks could be ascribed to a mismatch in thermal expansion and a resulting stress of more than 440 MPa acting on the Co_(2)Ti phase,as determined by density functional theory and nanoindentation.Furthermore,an excess laser energy caused chemical inhomogeneity and unmelted Ti powder particles,while a deficient laser energy resulted in a lack of fusion.Neither cracks nor partially melted powders were observed for a powder feed rate of 3 g/min and a laser power of 225–300 W,for which the dilution rate was minimized to less than 5%.For such samples,the cladding layers comprised pureα-Ti and a uniform CoT i interface with Co_(2)Ti islands.

关键词： Additive manufacturing Dissimilar metal joining Titanium Cobalt-based alloy

Role of kaempferol to increase bioavailability and pharmacokinetics of nifedipine in rats

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Natural Medicines 2019年第9期17卷 690-697页

作者： PARK Ji-won CHOI Jin-seok Hazardous Substances Analysis Division Gwangju Regional Office of Food and Drug SafetyGwangju 61012Republic of Korea Department of Medical Management Chodang UniversityJeollanam-do 58530Republic of Korea

Herein,the purpose of this study is to evaluate the effects of kaempferol on bioavailability and pharmacokinetics of nifedipine and its metabolite dehydronifedipine in rats.The experimental design is based on with or without kaempferol in the oral and intravenous administration of nifedipine in rats.Moreover,the pharmacokinetic parameters including nifedipine and dehydronifedipine were evaluated in rats.The in vitro studies of kaempferol were investigated on P-glycoprotein(P-gp)and cytochrome P450(CYP)3A4 activity.Kaempferol reduced a 50%inhibitory concentration(IC50)of 8.6μmol·L-1 on CYP3A4 enzyme activity.Moreover,kaempferol clearly improved the cell internalization of rhodamine-123 in MCF-7/ADR cells overexpressing P-gp.Depending on increased concentrations of kaempferol,the areas under the plasma concentration–time curve(AUC0-∞)and the peak concentration(Cmax)of nifedipine were increased after oral and intravenous administration.Moreover,the absolute bioavailability(AB)and relative bioavailability(RB)of nifedipine in the presence of kaempferol was significantly higher than those of the control group after oral and intravenous administration.Improvement of bioavailability of nifedipine by kaempferol may be mainly because of the inhibition of the P-gp-mediated efflux transporter in the small intestine and CYP3A4-mediated metabolism in the small intestine or liver,or both.

关键词： Nifedipine Kaempferol CYP3A4 P-gp Pharmacokinetics Bioavailability

Clinical course of sub-centimeter-sized nodules detected during surveillance for hepatocellular carcinoma

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2012年第21期18卷 2654-2660页

作者： yang won Min Geum-Youn Gwak Min Woo Lee Moon seok Choi Joon Hyoek Lee Kwang Cheol Koh Seung Woon Paik Byung Chul Yoo Department of Medicine Samsung Medical Center Sungkyunkwan University School of MedicineSeoul 135-710 South Korea Department of Radiology Samsung Medical Center Sungkyunkwan University School of MedicineSeoul 135-710 South Korea

AIM: To evaluate the outcome of sub-centimeter-sized nodules (SCSNs) detected during surveillance for hepatocellular carcinoma (HCC) in patients at risk. METHODS: We retrospectively analyzed a total of 142 patients with liver cirrhosis or chronic hepatitis B or C without a prior history of HCC in whom a SCSN was detected during HCC surveillance. We calculated the rate of HCC development from SCSNs in the study population and analyzed the differences in the baseline clinical characteristics and imaging features between the patients with SCSNs that eventually developed into HCC and patients with SCSNs that did not develop into HCC.RESULTS: During 667 person-years of follow-up, HCC developed in 33 patients. The calculated HCC development rate was 4.9% per year. The cumulative one-, two-, three- and five-year HCC development rates were 5.6%, 10.6%, 14.1% and 20.4%, respectively. Upon baseline comparison, the HCC group was older (54.4 ± 8.3 years vs 48.9 ± 9.4 years; P = 0.003) and had lower albumin levels (3.56 ± 0.58 g/dL vs 3.84 ± 0.55 g/dL; P = 0.012) and higher baseline alpha-fetoprotein (AFP) levels (8.5 ng/mL vs 5.4 ng/mL; P = 0.035) compared to the non-HCC group. Nodule pattern and initial radiologic diagnosis also differed between the two groups. Multivariate analysis revealed that age [P = 0.012, odds ratio (OR) =1.075, 95% confidence interval (CI) =1.016-1.137], sex (P = 0.009, OR = 3.969, 95% CI: 1.403-11.226), and baseline AFP level (P = 0.024, OR = 1.039, 95% CI: 1.005-1.073) were independent risk factors for developing HCC. CONCLUSION: The overall risk of HCC development in patients with SCSNs is similar to that in liver cirrhosis patients. Patients with these risk factors need to be closely monitored during follow-up.

关键词：检测监测肝细胞癌结节临床发展速度蛋白水平危险因素