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Bioinspired urease-powered micromotor as an active oral drug delivery carrier in stomach

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Bioactive Materials 2022年第3期7卷 54-62页

作者： Hyunsik Choi Sang hoon jeong Tae Yeon Kim jeeyoon Yi Sei Kwang Hahn Department of Materials Science and Engineering Pohang University of Science and Technology(POSTECH)77 Cheongam-roNam-guPohangGyeongbuk37673South Korea

Self-propelling micro-and nano-motors(MNMs)have been extensively investigated as an emerging oral drug delivery carrier for gastrointestinal(GI)tract ***,the propulsion of current MNMs reported so far is mostly based on the redox reaction of metals(such as Zn and Mg)with severe propulsion gas generation,remaining non-degradable residue in the GI ***,we develop a bioinspired enzyme-powered biopolymer micromotor mimicking the mucin penetrating behavior of Helicobacter pylori in the *** converts urea to ammonia and the subsequent increase of pH induces local gel-sol transition of the mucin layer facilitating the penetration into the stomach tissue *** successful fabrication of micromotors is confirmed by high-resolution transmission electron microscopy,electron energy loss spectroscopy,dynamic light scattering analysis,zeta-potential *** acidic condition,the immobilized urease can efficiently converted urea to ammonia,comparable with that of neutral condition because of the increase of surrounding pH during *** administration into the stomach,the micromotors show enhanced penetration and prolonged retention in the stomach for 24 ***,histological analysis shows that the micromotors are cleared within 3 days without causing any toxicity in the GI *** enhanced penetration and retention of the micromotors as an active oral delivery carrier in the stomach would be successfully harnessed for the treatment of various GI tract diseases.

关键词： Micro-and nanomotors Polydopamine Urease Oral delivery Stomach diseases

Deep learning for development of organic optoelectronic devices:efficient prescreening of hosts and emitters in deep-blue fluorescent OLEDs

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npj Computational Materials 2022年第1期8卷 1406-1416页

作者： Minseok jeong Joonyoung F.Joung Jinhyo Hwang Minhi Han Chang Woo Koh Dong hoon Choi Sungnam Park Department of Chemistry and Research Institute for Natural Science Korea UniversitySeoul02841Korea

The highest occupied molecular orbital(HOMO)and lowest unoccupied molecular orbital(LUMO)energies,which are key factors in optoelectronic devices,must be accurately estimated for newly designed ***,we developed a deep learning(DL)model that was trained with an experimental database containing the HOMO and LUMO energies of 3026 organic molecules in solvents or solids and was capable of predicting the HOMO and LUMO energies of molecules with the mean absolute errors of 0.058 ***,we demonstrated that our DL model was efficiently used to virtually screen optimal host and emitter molecules for organic light-emitting diodes(OLEDs).Deep-blue fluorescent OLEDs,which were fabricated with emitter and host molecules selected via DL prediction,exhibited narrow emission(bandwidth=36 nm)at 412 nm and an external quantum efficiency of 6.58%.Our DL-assisted virtual screening method can be further applied to the development of component materials in optoelectronics.

关键词： emitter optoelectronic OLEDs

Dynamic recrystallization behavior and microstructural evolution of Mg alloy AZ31 through high-speed rolling

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Journal of Materials Science & Technology 2018年第10期34卷 1747-1755页

作者： jeong Hun Lee Jong Un Lee Sang-hoon Kim Seok Weon Song Chong Soo Lee Sung Hyuk Park Ulsan Regional Division Korea Institute of Industrial Technology School of Materials Science and Engineering Kyungpook National University Technical Research Laboratories POSCO Graduate Institute of Ferrous Technology Pohang University of Science and Technology

High-speed rolling （HSR） is known to improve the workability of Mg alloys significantly, which makes it possible to impose a large reduction in a single pass without fracture. In the present study, dynamic recrystallization （DRX） behavior and microstructural and textural variations of Mg alloy AZ31 dur-ing a HSR process were investigated by conducting rolling with different imposed reductions in the range of 20%-80% at a high rolling speed of 470 m/min and 400℃. High-strain-rate deformation during HSR suppresses dislocation slips but promotes twinning, which results in the formation of numer-ous twins of several types, i.e., {10-12} extension twins, {10-11} and {10-13} contraction twins, and {10-11}-{10-12} double twins. After twinning, high strain energy is accumulated in twin bands because their crystallographic orientations are favorable for basal slips, leading to subsequent DRX at the twin bands. Accordingly, twinning activation and twinning-induced DRX behavior play crucial roles in accommodating plastic deformation during HSR and in varying microstructure and texture of the high- speed-rolled （HSRed） sheets. Area fraction of fine DRXed grains formed at the twin bands increases with increasing rolling reduction, which is attributed to the combined effects of increased strain, strain rate, and deformation temperature and a decreased critical strain for DRX. Size, internal strain, and texture intensity of the DRXed grains are smaller than those of unDRXed grains. Therefore, as rolling reduction increases, average grain size, stored internal energy, microstructural inhomogeneity, and basal texture intensity of the HSRed sheets gradually decrease owing to an increase in the area fraction of the DRXed grains.

关键词： Magnesium alloy High-speed rolling Twinning Dynamic recrystallization Microstructure

High-temperature Oxidation Behavior of Zircaloy-4 and Zirlo in Steam Ambient

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Journal of Materials Science & Technology 2010年第9期26卷 827-832页

作者： Hyung hoon Kim Jun Ho Kim Jin Young Moon Ho Seong Lee jeong Joo Kim Young Suck Chai School of Materials Science and Engineering Kyungpook National University School of Mechanical Engineering Yeungnam University214-1 Dae-dongGyeongsan-si

The oxidation characteristics for Zircaloy-4 and Zirlo in the temperature range of 700-1200°C under steam supply condition were investigated by using a modified thermo-gravimetric *** specimens were oxidized for 3600 s at each temperature and then quenched in a *** oxidation rate constants were measured from the weight gains to evaluate the oxidation behavior in Zircaloy-4 and *** weight gain rates of Zirlo were lower than those of Zircaloy-4,leading to the low rate *** different oxidation behaviors between both cladding materials were considered to be due to the difference in their chemical compositions.

关键词： Zircaloy-4 Zirlo Oxidation

Optimization of adipose tissue-derived mesenchymal stromal cells transplantation for bone marrow repopulation following irradiation

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World Journal of Stem Cells 2022年第3期14卷 245-263页

作者： Min-Jung Kim Won Moon jeonghoon Heo Sangwook Lim Seung-Hyun Lee jee-Yeong jeong Sang Joon Lee Department of Biochemistry Cancer Research Institute Kosin University College of MedicineSeo-gu 49267BusanSouth Korea Department of Internal Medicine Kosin University College of MedicineSeo-gu 49267BusanSouth Korea Department of Molecular Biology and Immunology Kosin University College of MedicineSeo-gu 49267BusanSouth Korea Department of Radiation Oncology Kosin University College of MedicineSeo-gu 49267BusanSouth Korea Department of General Surgery Kosin University College of MedicineSeogu 49267BusanSouth Korea Department of Ophthalmology Gospel HospitalKosin University College of MedicineSeo-gu 49267BusanSouth Korea

BACKGROUND Bone marrow(BM)suppression is one of the most common side effects of radiotherapy and the primary cause of death following exposure to *** concerted efforts,there is no definitive treatment method *** studies have reported using mesenchymal stromal cells(MSCs),but their therapeutic effects are *** We administered and examined the effects of various amounts of adipose-derived MSCs(ADSCs)in mice with radiation-induced BM *** Mice were divided into three groups:Normal control group,irradiated(RT)group,and stem cell-treated group following whole-body irradiation(WBI).Mouse ADSCs(mADSCs)were transplanted into the peritoneal cavity either once or three times at 5×10^(5) cells/200μ*** white blood cell count and the levels of,plasma cytokines,BM mRNA,and BM surface markers were compared between the three *** BM-derived CD34+hematopoietic progenitor cells were co-cultured with human ADSCs(hADSCs)or incubated in the presence of hADSCs conditioned media to investigate the effect on human cells in *** The survival rate of mice that received one transplant of mADSCs was higher than that of mice that received three *** transplantations of ADSCs delayed the repopulation of BM hematopoietic stem ***-inflammatory effects and M2 polarization by intraperitoneal ADSCs might suppress erythropoiesis and induce myelopoiesis in sub-lethally RT *** The results suggested that an optimal amount of MSCs could improve survival rates post-WBI.

关键词： Adipose tissue-derived stem cells Bone marrow suppression Mesenchymal stromal cells Radiation Cell therapy

Paradoxical carbon dioxide embolism during laparoscopic hepatectomy without intracardiac shunt:A case report

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World Journal of Clinical Cases 2022年第9期10卷 2908-2915页

作者： Soeun Jeon jeong-Min Hong Hyeon jeong Lee Yesul Kim Hyunjong Kang Boo-young Hwang Dowon Lee Young-hoon Jung Department of Anesthesia and Pain Medicine Pusan National UniversitySchool of MedicineBusan 49241South Korea Biomedical Research Institute Pusan National University HospitalBusan 49241South Korea

BACKGROUND Laparoscopic hepatectomy has recently become popular because it results in less bleeding than open ***,CO_(2)embolism occurs more *** CO_(2)embolisms during laparoscopic surgery are self-resolving and non-symptomatic;however,severe CO_(2)embolism may cause hypotension,cyanosis,arrhythmia,and cardiovascular *** particular,paradoxical CO_(2)embolisms are highly likely to cause neurological *** report a case of paradoxical CO_(2)embolism found on transesophageal echocardiography(TEE)during laparoscopic hepatectomy,although the patient had no intracardiac *** SUMMARY A 71-year-old man was admitted for laparoscopic left *** left hepatic vein ligation,the inferior vena cava was accidentally *** observed a sudden drop in oxygen saturation to 85%,decrease in systolic blood pressure(SBP)below 90 mm Hg,and reduction in end-tidal CO_(2)to 24 mm Hg.A“mill-wheel”murmur was auscultated over the *** fraction of inspired oxygen was increased to 100%with 5 cm H2O of positive end-expiratory pressure(PEEP)and hyperventilation was *** infusion was increased to maintain SBP above 90 mm Hg.A TEE probe was inserted,revealing gas bubbles in the right side of the heart,left atrium,left ventricle,and ascending *** surgeon reduced the pneumoperitoneum pressure from 17 to 14 mm Hg and repaired the damaged vessel ***,the patient’s hemodynamic status *** patient was transferred to the intensive care unit,recovering well without *** TEE monitoring is important to quickly determine the presence and extent of embolism in patients undergoing laparoscopic hepatectomy.

关键词： Carbon dioxide Embolism Laparoscopy Pneumoperitoneum Transesophageal echocardiography Case report

Management of the complications of endoscopic submucosal dissection

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World Journal of Gastroenterology 2011年第31期17卷 3575-3579页

作者： Seong Hwan Kim jeong Seop Moon Young hoon Youn Ki Myung Lee Sung Joon Lee Division of Gastroenterology Department of Internal MedicineEulji University Division of Gastroenterology Department of Internal MedicineInje UniversitySeoul Paik Hospital Division of Gastroenterology Department of Internal MedicineYonsei University-ang Nam Severance Hospital Division of Gastroenterology Department of Internal MedicineAjou University Hospital Division of Gastroenterology Department of Internal Medicineang-on University Hospital

Endoscopic submucosal dissection(ESD) is currently widely accepted as a standard treatment option for early gastrointestinal neoplasms in ***,ESD has technical difficulties and a longer procedure time than conventional endoscopic *** it may have a higher risk of complications than conventional endoscopic resection ***,the ESD study group of Korean Society of Gastrointestinal Endoscopy,have experienced many complications,mostly treated by endoscopic or conservative ***,we introduce and share our experiences for managementof post ESD complications and review published papers on the topic.

关键词： Endoscopic submucosal dissection Complication Management

Optic radiation injury in patients with aneurismal subarachnoid hemorrhage: a preliminary diffusion tensor imaging report

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Neural Regeneration Research 2018年第3期13卷 563-566页

作者： Sung Ho Jang Chul hoon Chang Young Jin Jung Seong Ho Kim jeong Pyo Seo Department of Physical Medicine and Rehabilitation College of Medicine Yeungnam University Department of Neurosurgery College of Medicine Yeungnam University

Visual field defect is one of the various clinical manifestations in patients with subarachnoid hemorrhage（SAH）. Little is known about the pathogenic mechanism of visual field defect in SAH. In the current study,we investigated the diffusion tensor imaging （DTI） finding of the optic radiation in patients with SAH followingrupture of a cerebral artery aneurysm. We recruited 21 patients with aneurismal SAH （12 males, 9 females, mean age, 52.67 years; range, 41–68 years） who showed no definite lesion along the visual ***-one age-and sex-matched normal control subjects were also recruited. DTI data were acquired at an average of 5.9 weeks （range： 3–12 weeks） after onset and reconstruction of the optic radiation was performed using DTI-Studio software. The fractional anisotropy value, apparent diffusion coefficient value,and fiber number of the optic radiation were measured. The fractional anisotropy value of the optic radiation was significantly decreased, and the apparent diffusion coefficient value was significantly increased, in patients with aneurismal SAH than in normal control subjects. However, there was no significant difference in the fiber number of the optic radiation between patients with aneurismal SAH and normal control subjects. The decrement of fractional anisotropy value and increment of apparent diffusion coefficient value of the optic radiation in patients with aneurismal SAH suggest optic radiation injury. Therefore, we recommend a thorough evaluation for optic radiation injury in patient with aneurismal SAH.

关键词： nerve regeneration diffusion tensor imaging optic radiation subarachnoid hemorrhage visual field defect neural regeneration

Efficacy of early treatment with infliximab in pediatric Crohn’s disease

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World Journal of Gastroenterology 2010年第14期16卷 1776-1781页

作者： Jong Seung Lee jee Hyun Lee Ji Hyuk Lee Hye Jin Lee Mi Jin Kim Hae jeong Lee Yon Ho Choe Department of Pediatrics College of Medicine Chung-Ang University Yongsan Hospital Yongsan Seoul 140-757 South Korea Department of Pediatrics Samsung Medical Center Sungkyunkwan University School of Medicine Gangnam Seoul 135-710 South Korea

AIM: To investigate the effectiveness of early infliximab use for induction and maintenance therapy in pediatric Crohn’s disease. METHODS: We performed a retrospective chart review of 36 patients with Crohn’s disease. Ten patients (group A) were treated with mesalamine after induction therapy with oral prednisolone, and 13 patients (group B) were treated with azathioprine after induction therapy with oral prednisolone. Thirteen patients (group C) received infliximab and azathioprine for induction and maintenance therapy for the first year, and were treated with azathioprine after 1 year. All patients were followed for at least 24 mo. Efficacy was determined by the relapse rate using the pediatric Crohn’s disease activity index score in each group at 12 and 24 mo. RESULTS: At the 1 year follow-up, the relapse ratee, Mi Jin Kim, Hae jeong Lee, Yon Ho Choe (23.1%, 3 of 13 patients) in group C was lower than that (61.5%, 8 of 13 patients) in group B (P = 0.047). At the 2 years follow-up, the relapse rate (38.5%, 5 of 13 patients) in group C was lower than that (76.9%, 10 of 13 patients) in group B (P = 0.047). Adverse events in group C were fewer than in groups A and B. CONCLUSION: Early induction with infliximab at diagnosis, known as "top-down" therapy, was effective for reducing the relapse rate compared to conventional therapies for at least 2 years.

关键词： Efficacy Infliximab Pediatric Crohn’s disease Relapse rate Top-down treatment