检索结果-南通市图书馆

Development of a two-stage virtual impactor for the generation of micrometer-scale monodisperse aerosols

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2024年第12期95卷 189-197页

作者： Jun-Hyung Lim Igor Kim Se-Jin yook School of Mechanical Engineering Hanyang UniversitySeoul04763Republic of Korea

Monodisperse particles are useful across a wide range of industrial applications,such as LCD displays,solar cells and rechargeable batteries,due to their uniformly small ***,generating high volumes of monodisperse particles remains *** this study,it was aimed to generate mono-disperse aerosols by classifying micrometer-scale solid aerosol particles within a narrow size ***,a new particle-size classification device with two virtual impactors connected in series and clean air cores was *** first-stage virtual impactor had a slightly larger cutoff size than the second-stage,and the major flow discharged from the first-stage was directed to the *** target particle size range was altered by changing the nozzle sizes in the first and second stages or by adjusting the flow ***,the classification performance of the two-stage virtual impactor was simulated and validated through an experiment using Arizona test *** implemented combi-nations of cutoff sizes for the first and second stages were 3.0 and 2.0μm,3.9 and 2.7μm,or 6.7 and 4.8μ*** a result,monodisperse aerosol particles were classified at a geometric standard deviation of 1.04-1.14 and a particle size range of 2-6.7μ*** two-stage virtual impactor developed herein may be useful for various research and performance evaluations,as it can classify micrometer-scale solid particle aerosols that exhibit high monodispersity.

关键词： Virtual impactor Clean air core Dust collection efficiency Monodispersity

Piezoelectric resonators with mechanical damping and resistance in current conduction

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2007年第5期50卷 650-672页

作者： yook-Kong YONG Mihir S PATEL Department of Civil and Environmental Engineering Rutgers University Piscataway NJ 08854 USA

A novel design method for high Q piezoelectric resonators was presented and proposed using the 3-D equations of linear piezoelectricity with quasi-electrostatic approximation which include losses attributed to mechanical damping in solid and resistance in current conduction. There is currently no finite element software for estimating the Q of a resonator without apriori assumptions of the resonator im- pedance or damping. There is a necessity for better and more realistic modeling of resonators and filters due to miniaturization and the rapid advances in frequency ranges in telecommunication. We presented new three-dimensional finite element models of quartz and barium titanate resonators with mechanical damping and resistance in current conduction. lee, Liu and Ballato’s 3-D equations of linear piezoelectricity with quasi-electro- static approximation which include losses attributed to mechanical damping in solid and resistance in current conduction were formulated in a weak form and implemented in COMSOL. The resulting finite element model could predict the Q and other electrical parameters for any piezoelectric resonator without apriori as- sumptions of damping or resistance. Forced and free vibration analyses were per- formed and the results for the Q and other electrical parameters were obtained. Comparisons of the Q and other electrical parameters obtained from the free vibra- tion analysis with their corresponding values from the forced vibration analysis were found to be in excellent agreement. Hence, the frequency spectra obtained from the free vibration analysis could be used for designing high Q resonators. Results for quartz thickness shear AT-cut and SC-cut resonators and thickness stretch poled barium titanate resonators were presented. An unexpected benefit of the model was the prediction of resonator Q with energy losses via the mounting supports.

关键词： quality factor, energy sink, MEMS, mechanical dissipation and viscosity, electrical conductivity, piezoelectric materials

Cytotoxicity and anti-inflammatory effects of root bark extracts of Acanthopanax henryi

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Natural Medicines 2014年第2期12卷 121-125页

作者： KIM Jong-Hwan LIU Xiang-Qian DAI Ling yook Chang-Soo lee Kyung-Tae Herbal Medicine Research Division Korea Food & Drug Administration Hunan Key Laboratory of Traditional Chinese Medicine modernization School of Pharmacy Hunan University of Chinese Medicine College of Pharmacy Kyung-Hee University

AIM: To investigate the cytotoxicity, anti-inflammatory activity, and action mechanism of root bark extracts of Acanthopanax henryi. METHOD: The hot methanol extract of the root bark of A. henryi was subjected to XAD-4 column chromatography eluting with a gradient of methanol in water. The cytotoxicity and anti-inflammatory effects of the MeOH fractions were evaluated on the inhibition on lipopolysaccharide(LPS)-induced nitric oxide, prostaglandin E2, interleukin-1β, and interleukin-6 production in RAW 264.7 macrophages. RESULTS: The 80% MeOH fraction was a better inhibitor of LPS-induced NO, PGE2, IL-1β, and IL-6 production, and expression of inducible nitric oxide synthase(iNOS) at the protein levels in a concentration-dependent manner. CONCLUSION: The 80% MeOH fraction of A. henryi root bark has significant anti-inflammatory activity. This provides a pharmacological basis for clinical application for the treatment of inflammation.

关键词： Acanthopanax henryi(Oliv.) Harms Root bark extract Cytotoxic activity Anti-inflammatory activity

PROPAGATION OF LOVE WAVES IN PRESTRESSED PIEZOELECTRIC LAYERED STRUCTURES LOADED WITH VISCOUS LIQUID

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2008年第6期21卷 542-548页

作者： Jianke Du Kai Xian Ji Wang yook-Kong Yong Department of Mechanics and Engineering Science School of Engineering Ningbo University Ningbo 315211 China Department of Civil and Environmental Engineering Rutgers University Piscataway NJ 08854 USA

We investigate analytically the effect of initial stress in piezoelectric layered structures loaded with viscous liquid on the dispersive and attenuated characteristics of Love waves, which involves a thin piezoelectric layer bonded perfectly to an unbounded elastic substrate. The effects of initial stress in the piezoelectric layer and the viscous coefficient of the liquid on the phase velocity of Love waves are analyzed. Numerical results are presented and discussed. The analytical method and the results can be useful for the design of chemical and biosensing liquid sensors.

关键词： Love waves piezoelectric viscous liquid initial stress

Endovascular treatment of traumatic renal artery pseudoaneurysm with a Stanford type A intramural haematoma:A case report

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2022年第27期10卷 9760-9767页

作者： yook Kim Jin Young lee Jin Suk lee Jin Bong Ye Se Heon Kim Young Hoon Sul Su Young Yoon Jung Hee Choi Hanlim Choi Department of Radiology Chungbuk National University HospitalCheongju-si 28644Chungcheongbuk-doSouth Korea Department of Trauma Surgery Chungbuk National University HospitalCheongju-si 28644Chungcheongbuk-doSouth Korea Department of Trauma Surgery College of MedicineChungbuk National UniversityCheongju-si 28644Chungcheongbuk-doSouth Korea Cardiovascular and Thoracic Surgery Chungbuk National University HospitalCheongju-si 28644Chungcheongbuk-doSouth Korea Anesthesiology and Pain Medicine Chungbuk National University HospitalCheongju-si 28644Chungcheongbuk-doSouth Korea Department of Surgery Chungbuk National University HospitalCheongju-si 28644Chungcheongbuk-doSouth Korea

BACKGROUND Aortic intramural hematoma(IMH) associated with aortic branch tear and intramurally located pseudoaneurysm after blunt trauma has not been ***,we report a case of progressive type A aortic IMH associated with a pseudoaneurysm arising from the injured proximal renal artery after blunt *** SUMMARY During logging operations,a 66-year-old man experienced blunt force trauma after being injured by a fallen *** arrived at our trauma center with a left flank pain *** tomography(CT) revealed a pseudoaneurysm arising from the proximal renal artery(localized within the aortic media) and Stanford type A IMH.A covered stent was deployed along the left main renal artery,bridging the pseudoaneurysm and covering the parent artery,successfully excluding the pseudoaneurysm as confirmed using ***,although the degree of the pseudoaneurysm decreased,follow-up CT revealed remnant pseudoaneurysm,likely caused by an ***,a covered stent was additionally installed through the previously deployed covered *** exclusion of the pseudoaneurysm was confirmed using final *** the 7-mo follow-up CT scan,the IMH and pseudoaneurysm completely disappeared with no evidence of stent-related *** Endovascular treatment such as stent-graft placement can be an effective and safe treatment for traumatic renal artery injury.

关键词： Aortic intramural hematoma Blunt trauma Intimomedial tear Renal arterial injury Stent-graft Case report

Gelfoam embolization for distal, medium vessel injury during mechanical thrombectomy in acute stroke: A case report

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2021年第20期9卷 5668-5674页

作者： Ji Yun Kang Kyung Sik Yi Sang-Hoon Cha Chi-Hoon Choi yook Kim Jisun lee Bum Sang Cho Department of Radiology Chungbuk National University HospitalCheongju 28644South Korea College of Medicine and Medical Research Institute Chungbuk National UniversityCheongju 28644South Korea

BACKGROUND Arterial perforation has inevitably increased as endovascular treatments have become more common for intracranial large vessel occlusions,and even distal,medium vessel occlusions.A distal,medium vessel has a tortuous course and thinner wall compared to large arteries,making it more susceptible to ***,we review the treatment strategies for arterial perforation during mechanical thrombectomy,and we report the case of a patient treated with gelfoam *** SUMMARY A 63-year-old woman presented to the emergency department with sudden neurologic symptoms of right hemiparesis and global *** initial National Institutes of Health Stroke Scale score was *** tomography(CT)and CT angiography revealed hyperacute infarction and emergent arterial occlusion of the left middle cerebral artery M2-3 *** endovascular mechanical thrombectomy,arterial rupture *** patient’s vital signs were stable,but delayed angiography showed persistent active ***,selective embolization of the injured artery was performed using *** left vertebral and internal carotid angiography was performed to confirm hemostasis.A localized subarachnoid hemorrhage(SAH)was confirmed on a follow-up CT scan.A repeated CT scan after 12 d showed resolution of the SAH,and rebleeding did not *** Rescue embolization with gelfoam could be considered an additional option in distal,medium vessel perforation.

关键词： Gelfoam Embolization Acute ischemic stroke Mechanical thrombectomy Arterial perforation Case report

Endoscopic salvage treatment of histoacryl after stent application on the anastomotic leak after gastrectomy: A case report

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2021年第1期9卷 262-266页

作者： Hee-Sung Kim yook Kim Joung-Ho Han Department of Internal Medicine Chungbuk National University HospitalChungbuk National University College of MedicineCheongju-si 28644South Korea Department of Radiology Chungbuk National University HospitalCheongju-si 28644South Korea

BACKGROUND Endoscopic approach could effectively manage postoperative anastomotic *** endoscopic methods have been developed for the treatment of anastomotic *** SUMMARY A 53-year-old woman developed anastomotic leak after laparoscopic proximal *** clip closure failed due to strong wall tension;therefore,a fully covered self-expandable esophageal metal stent(fc-SEMS)was placed to cover the leak after it was filled with a mixture of fibrin glue and ***,fluoroscopy with gastrograffin showed dye leaking out of the *** the previous fluoroscopic image for guidance,a catheter was inserted at the leakage *** radiocontrast dye was injected and was seen spreading along the sinus ***,histoacryl was *** days after the last procedure,upper gastrointestinal contrast studies showed no *** patient was subsequently discharged 9 d after histoacryl injection without any *** To seal an anastomosis leak after stent application,salvage technique using histoacryl injection at the leakage site with fluoroscopy guidance could be considered cautiously.

关键词： Anastomotic leak Stent Histoacryl Endoscopy Gastrectomy Gastric cancer Case report

Absence of enhancement in a lesion does not preclude primary central nervous system T-cell lymphoma:A case report

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2024年第2期12卷 374-382页

作者： Chan-Seop Kim Chi-Hoon Choi Kyung Sik Yi yook Kim Jisun lee Chang Gok Woo Young Hun Jeon Department of Radiology Chungbuk National University HospitalChungbuk National University College of MedicineCheongju-si 28644Chungcheongbuk-doSouth Korea Department of Pathology Chungbuk National University HospitalChungbuk National University College of MedicineCheongju-si 28644Chungcheongbuk-doSouth Korea Department of Radiology Seoul National University HosptialSeoul 03080South Korea

BACKGROUND Primary central nervous system lymphoma(PCNSL)is a non-Hodgkin lymphoma that originates in the central nervous system(CNS)and is exclusively limited to the *** most PCNSLs are diffuse large B-cell lymphomas,primary CNS T-cell lymphomas(PCNSTLs)are *** typically demonstrate some degree of enhancement on contrast-enhanced magnetic resonance imaging(MRI).To the best of our knowledge,non-enhancing PCNSTL has not been reported *** SUMMARY A 69-year-old male presented to the neurology department with complaints of mild cognitive impairment and gradual onset of left lower leg weakness over a span of two *** MRI showed asymmetric T2-hyperintense lesions within the *** enhancement was observed on the contrast-enhanced T1 *** initial diagnosis was neuro-Behçet’s *** high-dose steroid therapy,no alterations in the lesions were identified on initial *** patient’s symptoms deteriorated *** MRI performed one month after the initial scan revealed an increased lesion ***,brain biopsy confirmed the diagnosis of *** patient underwent definitive combined ***,the patient developed bacteremia and died of septic shock approximately three months after *** The absence of enhancement in the lesion did not rule out PCNSTL.A biopsy approach is advisable for pathological confirmation.

关键词： Central nervous system neoplasms Non-Hodgkin Lymphoma T-cell Lymphoma Primary central nervous system lymphoma Primary central nervous system T-cell lymphoma Case report

Optimal proximal resection margin distance for gastrectomy in advanced gastric cancer

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2020年第18期26卷 2232-2246页

作者： Amy Kim Beom Su Kim Jeong Hwan yook Byung Sik Kim Division of Stomach Surgery Department of SurgeryAsan Medical CenterUniversity of Ulsan College of MedicineSeoul 05505South Korea Department of Surgery Korea University Medical Center Ansan HospitalAnsanGyeonggi-do 15355South Korea

BACKGROUND The conventional guidelines to obtain a safe proximal resection margin(PRM)of5-6 cm during advanced gastric cancer(AGC)surgery are still applied by many surgeons across the *** recent studies have raised questions regarding the need for such extensive resection,but without reaching *** study was designed to prove that the PRM distance does not affect the prognosis of patients who undergo gastrectomy for *** To investigate the influence of the PRM distance on the prognosis of patients who underwent gastrectomy for *** Electronic medical records of 1518 patients who underwent curative gastrectomy for AGC between June 2004 and December 2007 at Asan Medical Center,a tertiary care center in Korea,were reviewed retrospectively for the *** demographics and clinicopathologic outcomes were compared between patients who underwent surgery with different PRM distances using one-way ANOVA and Fisher’s exact test for continuous and categorical variables,*** influence of PRM on recurrence-free survival and overall survival were analyzed using Kaplan-Meier survival analysis and Cox proportional hazard *** The median PRM distance was 4.8 cm and 3.5 cm in the distal gastrectomy(DG)and total gastrectomy(TG)groups,*** cohorts in the DG and TG groups were subdivided into different groups according to the PRM distance;≤1.0 cm,1.1-3.0 cm,3.1-5.0 cm and>5.0 *** DG and TG groups showed nostatistical difference in recurrence rate(23.5%vs 30.6%vs 24.0%vs 24.7%,P=0.765)or local recurrence rate(5.9%vs 6.5%vs 8.4%vs 6.2%,P=0.727)according to the distance of *** both groups,Kalpan-Meier analysis showed no statistical difference in recurrence-free survival(P=0.467 in DG group;P=0.155 in TG group)or overall survival(P=0.503 in DG group;P=0.155 in TG group)according to the PRM *** analysis using Cox proportional hazard model revealed that in both groups,there was no significant differ

关键词： Stomach neoplasms Gastrectomy Margins of excision Prognosis Recurrence