Publications by authors named "Young-Jun Lee"

135 Publications

Fluorescence Switchable Block Copolymer Particles with Doubly Alternate-Layered Nanoparticle Arrays.

Small 2021 Jun 10:e2101222. Epub 2021 Jun 10.

Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.

The precise self-assembly of block copolymers (BCPs) and inorganic nanoparticles (NPs) under 3D confinement offers microparticles with programmable nanostructures and functionalities. Here, fluorescence-switchable hybrid microspheres are developed by forming doubly alternating arrays of Au NPs and CdSe/ZnS quantum dots (QDs) within polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) BCP domains. These doubly alternating arrays afford controlled nonradiative energy transfer (NRET) between the QDs and Au NPs that is dependent on the layer-to-layer distance. Solvent-selective swelling of the hybrid particles tunes the distance between layers, modulating their NRET behavior and affording switchable fluorescence. The particle fluorescence is "OFF" in water through strong NRET from the QDs to Au NPs, but is "ON" in alcohols due to the increased distance between the Au NP and QD arrays in the swollen P4VP domains. The experimentally observed NRET intensity as a function of interparticle distance shows larger quenching efficiencies than those theoretically predicted due to the enhanced quenching within a 3D-confined system. Finally, the robust and reversible fluorescence switching of the hybrid particles in different solvents is demonstrated, highlighting their potentials for bioimaging, sensing, and diagnostic applications.
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http://dx.doi.org/10.1002/smll.202101222DOI Listing
June 2021

Highly Sensitive Hybrid Nanostructures for Dimethyl Methyl Phosphonate Detection.

Micromachines (Basel) 2021 May 31;12(6). Epub 2021 May 31.

INHA IST and Laboratory of Intelligent Devices and Thermal Control, Department of Mechanical Engineering, Inha University, Incheon 22212, Korea.

Nanostructured materials synthesized by the hydrothermal and thermal reduction process were tested to detect the dimethyl methylphosphonate (DMMP) as a simulant for chemical warfare agents. Manganese oxide nitrogen-doped graphene oxide with polypyrrole ([email protected]/PPy) exhibited the sensitivity of 51 Hz for 25 ppm of DMMP and showed the selectivity of 1.26 Hz/ppm. Nitrogen-doped multi-walled carbon nanotube (N-MWCNT) demonstrated good linearity with a correlation coefficient of 0.997. A comparison between a surface acoustic wave and quartz crystal microbalance sensor exhibited more than 100-times higher sensitivity of SAW sensor than QCM sensor.
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http://dx.doi.org/10.3390/mi12060648DOI Listing
May 2021

Brain White Matter Maturation and Early Developmental Outcomes in Preterm Infants With Retinopathy of Prematurity.

Invest Ophthalmol Vis Sci 2021 Feb;62(2)

Department of Pediatrics, Hanyang University Hospital, Hanyang University College of Medicine, Seoul, Republic of Korea.

Purpose: To investigate brain white matter pathways using magnetic resonance diffusion tensor imaging (DTI) and correlate the findings with developmental outcomes at 18 months of corrected age in preterm infants with and without retinopathy of prematurity (ROP).

Methods: In this prospective cohort study, probabilistic maps of the 26 white matter pathways associated with motor, cognitive, visual, and limbic/language functions were generated in 84 preterm infants using DTI obtained at term-equivalent age. The mean fractional anisotropy (FA) and mean diffusivity (MD) values were compared between those with and without ROP. Developmental outcomes were assessed using the third edition of Bayley Scales of Infant and Toddler Development (BSID-III) at 18 months of corrected age. Multiple regression analyses were performed to confirm the association among developmental outcomes, white matter pathways, and ROP or severe ROP after adjusting for potential confounders.

Results: The white matter pathways were insignificantly associated with ROP or severe ROP. There were no significant differences in the FA and MD values of the pathways between ROP infants treated with and without bevacizumab therapy. Furthermore, there were no significant differences in BSID-III scores between infants with and without ROP or severe ROP. The BSID-III scores at 18 months of age showed a significant association with FA or MD values in several pathways.

Conclusions: ROP or severe ROP was insignificantly associated with maturation delay of the white matter pathways. Developmental outcomes were similar between preterm infants with and without ROP or severe ROP or between ROP infants with and without intravitreal bevacizumab therapy.
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http://dx.doi.org/10.1167/iovs.62.2.2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7862727PMC
February 2021

Delayed Maturation of the Middle Cerebellar Peduncles at Near-Term Age Predicts Abnormal Neurodevelopment in Preterm Infants.

Neonatology 2021 27;118(1):37-46. Epub 2021 Jan 27.

Department of Pediatrics, Hanyang University College of Medicine, Seoul, Republic of Korea,

Background: The infant brain grows quickly with elaborate microstructural development during the neonatal period. The white matter, during critical periods of development, is selectively vulnerable to altered maturation and impaired growth in very-low-birth-weight (VLBW) infants.

Objective: To evaluate whether abnormal white matter maturation in VLBW infants is associated with poor neurodevelopmental outcomes at 18 months of corrected age.

Methods: Between 2015 and 2017, we recruited 60 VLBW infants at 24-32 weeks of gestational age and 15 full-term controls. All participants underwent magnetic resonance imaging at near-term age and were assessed at 18 months of corrected age with the Bayley Scales of Infant and Toddler Development, Third Edition. The associations between regional white matter fractional anisotropy (FA) and mean diffusivity on diffusion tensor imaging (DTI) and developmental outcomes were explored using multivariable linear regression after correcting for gestational age, postmenstrual age at DTI scan, and maternal education level.

Results: The FA values of the splenium of the corpus callosum (p = 0.032), corticospinal tract (p = 0.025), middle cerebellar peduncle (MCP) (p < 0.001), and cingulum (p = 0.043) were significantly related to cognitive scores; however, only the association corresponding to the MCP remained significant after correcting for multiple comparisons. The MCP FA (p = 0.008) was associated with motor scores after correction for multiple comparisons (p = 0.008). Cognitive impairment (area under the curve [AUC] = 0.823, 95% confidence interval [CI] = 0.722-0.911) and motor impairment (AUC = 0.776, 95% CI = 0.656-0.899) were predicted by MCP FA.

Conclusions: The FA of MCP at near-term age may predict developmental outcomes of VLBW infants at 18 months of corrected age.
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http://dx.doi.org/10.1159/000512921DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8117383PMC
January 2021

Altered asymmetries of the structural networks comprising the fronto-limbic brain circuitry of preterm infants.

Sci Rep 2021 Jan 14;11(1):1318. Epub 2021 Jan 14.

Department of Pediatrics, Hanyang University Hospital, Hanyang University College of Medicine, 17 Haengdang-dong, Seongdong-gu, Seoul, 133-792, Republic of Korea.

This study aimed to elaborate upon prior findings suggestive of the altered lateralization of structural connectivity in the developing preterm brain by using diffusion tensor imaging tractography to explore how network topological asymmetries in fronto-limbic neural circuitry are altered at 36-41 weeks, postmenstrual age in 64 preterm infants without severe brain injury and 33 term-born infants. We compared the pattern of structural connectivity and network lateralization of the betweenness centrality in the medial fronto-orbital gyrus, superior temporal gyrus, amygdala, and hippocampus-the structures comprising the fronto-limbic brain circuit-between preterm and term infants. Global efficiency, local efficiency, and small-world characteristics did not differ significantly between the two hemispheres in term-born infants, suggesting that integration and segregation are balanced between the left and right hemispheres. However, the preterm brain showed significantly greater leftward lateralization of small-worldness (P = 0.033); the lateralization index of the betweenness centrality revealed that the medial fronto-orbital gyrus (P = 0.008), superior temporal gyrus (P = 0.031), and hippocampus (P = 0.028) showed significantly increased leftward asymmetry in preterm infants relative to term-infants independent of sex, age at imaging, and bronchopulmonary dysplasia. The altered lateralization of fronto-limbic brain circuitry might be involved in the early development of social-emotional disorders in preterm infants.
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http://dx.doi.org/10.1038/s41598-020-79446-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7809421PMC
January 2021

Softness- and Size-Dependent Packing Symmetries of Polymer-Grafted Nanoparticles.

ACS Nano 2020 Aug 5;14(8):9644-9651. Epub 2020 Aug 5.

Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.

Achieving ordered arrays of nanoparticles (NPs) with controlled packing symmetry and interparticle spacing is of great importance to design complex metamaterials. Herein, we report softness- and size-dependent self-assembly behavior of polystyrene-grafted Au NPs ([email protected] NPs). We varied the core size of Au NPs from 1.9 to 9.6 nm and the number-average molecular weight () of thiol-terminated polystyrene from 1.8 to 7.9 kg mol. The optimal packing model based on an "effective softness" parameter λ that accounts for close-packed and semidilute brush regimes could predict the effective radius of [email protected] NPs (within ±9%) for a wide range of PS , grafting density, and Au core size. With increasing λ, the self-assembled [email protected] NP superlattices undergo a symmetry transition from hexagonal close packed (hcp) to body-centered tetragonal (bct) to body-centered cubic (bcc). This work demonstrates the effective softness model as a simple but robust tool for the design of NP superlattices with precisely controlled interparticle distance and packing symmetry, both of which are critical for the development of sophisticated materials through control of nanoscale structure.
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http://dx.doi.org/10.1021/acsnano.0c00668DOI Listing
August 2020

Effect of atelocollagen on the healing status after medial meniscal root repair using the modified Mason-Allen stitch.

Orthop Traumatol Surg Res 2020 Sep 1;106(5):969-975. Epub 2020 Aug 1.

Department of Orthopaedic Surgery, Myongji Hospital, Goyang-si, Gyeonggi-do, Korea. Electronic address:

Introduction: Addition of collagen during medial meniscal root repair (MMRR) may improve meniscal root healing minimising fibrous scar tissue formation. The purpose of this study was to verify the effect of atelocollagen on MMRR using the modified Mason-Allen stitch when compared with that of the conventional pullout repair by assessing the clinical and radiological outcomes.

Hypothesis: It was hypothesised that atelocollagen would enhance the healing effect on the meniscal root following MMRR. Moreover, we presumed that MMRR with atelocollagen application might reduce meniscal extrusion by promoting healing.

Materials And Methods: A total of 47 patients who underwent MMRR using the modified Mason-Allen stitch between 2015 and 2016 were included, and they were divided into group A (atelocollagen application; n=25) and group R (MMRR without atelocollagen application; n=22). The postoperative clinical outcomes, radiological outcomes, and meniscal root healing and medial compartment cartilage status on follow-up magnetic resonance imaging (MRI) were compared between the two groups.

Results: Mean follow-up duration was 26.4±4.8 months in group A and 27.1±5.2 months in group R (p=0.598). Mean duration from surgery to follow-up MRI was 12.5±1.4 months in group A and 12.7±1.2 months in group R (p=0.604). The subjective knee scores improved significantly in both groups at the last follow-up (all, p<0.001). The Kellgren-Lawrence (K-L) grade progressed in 16% and 22.7% in group A and group R, respectively (p=0.351). Follow-up MRI showed progression of cartilage loss in the medial compartment in 28% and 40.9% in group A and group R, respectively (p=0.355). In terms of meniscal root healing, 18 (72%) and 12 (54.5%) patients had complete healing, and 6 (24%) and 8 (36.4%) patients had partial healing in groups A and R, respectively. The mean value of the intra-meniscal signal intensity (IMSI) of the meniscal root based on MRI in group A was significantly lower than that in group R (p<0.001). The medial meniscal extrusion in groups A and R decreased by 0.2±0.1mm and 0.1±0.3mm following MMRR without significant differences (p=0.056 and p=0.229, respectively). The IMSI presented significant negative correlations with the root healing status and significant positive correlations with K-L grade progression (p<0.05).

Discussion: Atelocollagen application during MMRR yielded lower IMSIs, suggesting better healing, than did conventional pullout root repair. However, this technique could not demonstrate beneficial effects on meniscal extrusion.

Level Of Evidence: III, retrospective case-control study.
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http://dx.doi.org/10.1016/j.otsr.2020.03.022DOI Listing
September 2020

Hydrogen Sensors Based on MoS Hollow Architectures Assembled by Pickering Emulsion.

ACS Nano 2020 Aug 31;14(8):9652-9661. Epub 2020 Jul 31.

For rapid hydrogen gas (H) sensing, we propose the facile synthesis of the hollow structure of Pt-decorated molybdenum disulfide (h-MoS/Pt) using ultrathin (mono- or few-layer) two-dimensional nanosheets. The controlled amphiphilic nature of MoS surface produces ultrathin MoS NS-covered polystyrene particles one-step Pickering emulsification. The incorporation of Pt nanoparticles (NPs) on the MoS, followed by pyrolysis, generates the highly porous h-MoS/Pt. This hollow hybrid structure produces sufficiently permeable pathways for H and maximizes the active sites of MoS, while the Pt NPs on the hollow MoS induce catalytic H spillover during H sensing. The h-MoS/Pt-based chemiresistors show sensitive H sensing performances with fast sensing speed (response, 8.1 s for 1% of H and 2.7 s for 4%; and recovery, 16.0 s for both 1% and 4% H at room temperature in the air). These results mark the highest H sensing speed among 2D material-based H sensors operated at room temperature in air. Our fabrication method of h-MoS/Pt structure through Pickering emulsion provides a versatile platform applicable to various 2D material-based hollow structures and facilitates their use in other applications involving surface reactions.
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http://dx.doi.org/10.1021/acsnano.0c00821DOI Listing
August 2020

Combined effects of mesenchymal stem cells carrying cytosine deaminase gene with 5-fluorocytosine and temozolomide in orthotopic glioma model.

Am J Cancer Res 2020 1;10(5):1429-1441. Epub 2020 May 1.

Department of Anatomy, Ajou University School of Medicine Suwon, South Korea.

Glioblastoma multiforme (GBM) is the most common and aggressive primary brain tumor, and current standard therapy provides modest improvements in progression-free and overall survival of patients. Innate tumor resistance and presence of the blood-brain barrier (BBB) require the development of multi-modal therapeutic regimens. Previously, cytosine deaminase (CD)-expressing mesenchymal stem cells (MSC/CD) were found to exhibit anticancer activity with a wide therapeutic index by converting 5-fluorocytosine (5-FC), a nontoxic prodrug into 5-fluorouracil (5-FU), a potent anticancer drug. In this study, we evaluated the efficacy of MSC/CD in a multi-modal combination regimen with temozolomide (TMZ). Cell viability test, cell cycle, and normalized isobologram analyses were performed. anticancer effects were tested in a mouse orthotopic glioma model. TMZ and MSC/CD with 5-FC synergistically interacted and suppressed U87 glioma cell line growth . Combined treatment with TMZ and 5-FU increased cell cycle arrest and DNA breakage. In an orthotopic xenograft mouse model, treatment with TMZ alone suppressed tumor growth; however, this effect was more intense with MSC/CD transplantation followed by the sequential treatment with 5-FC and TMZ. Therefore, we propose that sequential treatment with 5-FC and MSC/CD can be used in patients with GBM during the immediate postoperative period to sensitize tumors to subsequent adjuvant chemo- and radiotherapy.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7269785PMC
May 2020

Comparison of surgical outcomes among different methods of esophagojejunostomy in laparoscopic total gastrectomy for clinical stage I proximal gastric cancer: results of a single-arm multicenter phase II clinical trial in Korea, KLASS 03.

Surg Endosc 2021 Mar 6;35(3):1156-1163. Epub 2020 Mar 6.

Department of Surgery, Incheon St. Mary's Hospital, The Catholic University of Korea College of Medicine, 56 Dongsuro, Bupyong-Gu, Inchon, 21431, Korea.

Background: Laparoscopic distal gastrectomy for early gastric cancer has been widely accepted, but laparoscopic total gastrectomy has still not gained popularity because of technical difficulty and unsolved safety issue. We conducted a single-arm multicenter phase II clinical trial to evaluate the safety and the feasibility of laparoscopic total gastrectomy for clinical stage I proximal gastric cancer in terms of postoperative morbidity and mortality in Korea. The secondary endpoint of this trial was comparison of surgical outcomes among the groups that received different methods of esophagojejunostomy (EJ).

Methods: The 160 patients of the full analysis set group were divided into three groups according to the method of EJ, the extracorporeal circular stapling group (EC; n = 45), the intracorporeal circular stapling group (IC; n = 64), and the intracorporeal linear stapling group (IL; n = 51). The clinicopathologic characteristics and the surgical outcomes were compared among these three groups.

Results: There were no significant differences in the early complication rates among the three groups (26.7% vs. 18.8% vs. 17.6%, EC vs. IC vs. IL; p = 0.516). The length of mini-laparotomy incision was significantly longer in the EC group than in the IC or IL group. The anastomosis time was significantly shorter in the EC group than in the IL group. The time to first flatus was significantly shorter in the IL group than in the EC group. The long-term complication rate was not significantly different among the three groups (4.4% vs. 12.7% vs. 7.8%; EC vs. IC vs. IL; p = 0.359), however, the long-term incidence of EJ stenosis in IC group (10.9%) was significantly higher than in EC (0%) and IL (2.0%) groups (p = 0.020).

Conclusions: The extracorporeal circular stapling and the intracorporeal linear stapling were safe and feasible in laparoscopic total gastrectomy, however, intracorporeal circular stapling increased EJ stenosis.
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http://dx.doi.org/10.1007/s00464-020-07480-0DOI Listing
March 2021

A novel visual ranking system based on arterial spin labeling perfusion imaging for evaluating perfusion disturbance in patients with ischemic stroke.

PLoS One 2020 24;15(1):e0227747. Epub 2020 Jan 24.

Department of Nuclear Medicine, Hanyang University College of Medicine, Hanyang University Hospital, Seoul, Republic of Korea.

We developed a visual ranking system by combining the parenchymal perfusion deficits (PPD) and hyperintense vessel signals (HVS) on arterial spin labeling (ASL) imaging. This study aimed to assess the performance of this ranking system by correlating with subtypes classified based on dynamic susceptibility contrast (DSC) imaging for evaluating the perfusion disturbance observed in patients with ischemic stroke. 32 patients with acute or subacute infarcts detected by DSC imaging were reviewed. Each patient's brain was divided into 12 areas. ASL ranks were defined by the presence (+) or absence (-) of PPD/HVS as follows; I:-/-, II:-/+, III: +/+, and IV: +/-. DSC imaging findings were categorized based on cerebral blood flow (CBF) and time to peak (TTP) as normal (normal CBF/TTP), mismatched (normal CBF/delayed TTP), and matched (decreased CBF/delayed TTP). Two reviewers rated perfusion abnormalities in the total of 384 areas. The four ASL ranks correlated well with the DSC subtypes (Spearman's r = 0.82). The performance of ASL ranking system was excellent as indicated by the area under the curve value of 0.94 using either matched or mismatched DSC subtype as the gold standard and 0.97 using only the matched DSC subtype as the gold standard. The two methods were in good-to-excellent agreement (maximum κ-values, 0.86). Inter-observer agreement was excellent (κ-value, 0.98). Although the number of patients was small and the number of dropouts was high, our proposed, ASL-based visual ranking system represented by PPD and HVS provides good, graded estimates of perfusion disturbance that agree well with those obtained by DSC perfusion imaging.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0227747PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6980418PMC
April 2020

Porous materials of nitrogen doped graphene [email protected] electrode for capable supercapacitor application.

Sci Rep 2019 Sep 2;9(1):12622. Epub 2019 Sep 2.

Department of Mechanical Engineering, Inha University, Inha-ro 100, Nam-gu, Incheon, 402-751, Republic of Korea.

The porous materials of [email protected] composite was synthesized by thermal reduction process at 550 °C in presence ammonia and urea as catalyst. In this process, the higher electrostatic attraction between the [email protected] nanoparticles were anchored via thermal reduction reaction. These synthesized [email protected] NGO composites were confirmed by Raman, XRD, XPS, HR-TEM, and EDX results. The SnO nanoparticles were anchored in the NGO composite in the controlled nanometer scale proved by FE-TEM and BET analysis. The [email protected] composite was used to study the electrochemical properties of CV, GCD, and EIS analysis for supercapacitor application. The electrochemical properties of [email protected] exhibited the specific capacitance (~378 F/g at a current density of 4 A/g) and increasing the cycle stability up to 5000 cycles. Therefore, the electrochemical results of [email protected] composite could be promising for high-performance supercapacitor applications.
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http://dx.doi.org/10.1038/s41598-019-48951-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6718653PMC
September 2019

Light-Responsive, Shape-Switchable Block Copolymer Particles.

J Am Chem Soc 2019 Sep 4;141(38):15348-15355. Epub 2019 Sep 4.

Department of Chemical and Biomolecular Engineering , Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141 , Republic of Korea.

A robust strategy is developed for preparing light-responsive block copolymer (BCP) particles in which shape and color can be actively controlled with high spatial and temporal resolution. The key to achieving light-responsive shape transitions of BCP particles is the design and synthesis of surfactants containing light-active groups (i.e., nitrobenzyl esters and coumarin esters) that modulate the amphiphilicity and interfacial activity of the surfactants in response to light of a specific wavelength. These light-induced changes in surfactant structure modify the surface and wetting properties of BCP particles, affording both shape and morphological transitions of the particles, for example from spheres with an onion-like inner morphology to prolate or oblate ellipsoids with axially stacked nanostructures. In particular, wavelength-selective shape transformation of the BCP particles can be achieved with a mixture of two light-active surfactants that respond to different wavelengths of light (i.e., 254 and 420 nm). Through the use of light-emitting, photoresponsive surfactants, light-induced changes in both color and shape are further demonstrated. Finally, to demonstrate the potential of the light-triggered shape control of BCP particles in patterning features with microscale resolution, the shape-switchable BCP particles are successfully integrated into a patterned, free-standing hydrogel film, which can be used as a portable, high-resolution display.
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http://dx.doi.org/10.1021/jacs.9b07755DOI Listing
September 2019

Recent Trend for Endovascular Treatment in Patients with Acute Ischemic Stroke: Balloon Guide Catheter.

Neurointervention 2019 Sep 16;14(2):142-143. Epub 2019 Aug 16.

Department of Radiology, Hanyang University Hospital, Hanyang University College of Medicine, Seoul, Korea.

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http://dx.doi.org/10.5469/neuroint.2019.00136DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6736498PMC
September 2019

Balloon Guide Catheter Is Beneficial in Endovascular Treatment Regardless of Mechanical Recanalization Modality.

Stroke 2019 06 2;50(6):1490-1496. Epub 2019 May 2.

Department of Neurosurgery, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea (H.-J.J.).

Background and Purpose- Based on its mechanism, the use of balloon guide catheters (BGCs) may be beneficial during endovascular treatment, regardless of the type of mechanical recanalization modality used-stent retriever thrombectomy or thrombaspiration. We evaluated whether the use of BGCs can be beneficial regardless of the first-line mechanical endovascular modality used. Methods- We retrospectively reviewed consecutive acute stroke patients who underwent stent retriever thrombectomy or thrombaspiration from the prospectively maintained registries of 17 stroke centers nationwide. Patients were assigned to the BGC or non-BGC group based on the use of BGCs during procedures. Endovascular and clinical outcomes were compared between the BGC and non-BGC groups. To adjust the influence of the type of first-line endovascular modality on successful recanalization and favorable outcome, multivariable analyses were also performed. Results- This study included a total of 955 patients. Stent retriever thrombectomy was used as the first-line modality in 526 patients (55.1%) and thrombaspiration in 429 (44.9%). BGC was used in 516 patients (54.0%; 61.2% of stent retriever thrombectomy patients; 45.2% of thrombaspiration patients). The successful recanalization rate was significantly higher in the BGC group compared with the non-BGC group (86.8% versus 74.7%, respectively; P<0.001). Furthermore, the first-pass recanalization rate was more frequent (37.0% versus 14.1%; P<0.001), and the number of device passes was fewer in the BGC group (2.5±1.9 versus 3.3±2.1; P<0.001). The procedural time was also shorter in the BGC group (54.3±27.4 versus 67.6±38.2; P<0.001). The use of BGC was an independent factor for successful recanalization (odds ratio, 2.18; 95% CI, 1.54-3.10; P<0.001) irrespective of the type of first-line endovascular modality used. The use of BGC was also an independent factor for a favorable outcome (odds ratio, 1.40; 95% CI, 1.02-1.92; P=0.038) irrespective of the type of first-line endovascular modality used. Conclusions- Regardless of the first-line mechanical endovascular modality used, the use of BGC in endovascular treatment was beneficial in terms of both recanalization success and functional outcome.
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http://dx.doi.org/10.1161/STROKEAHA.118.024723DOI Listing
June 2019

Asymptomatic Basilar Artery Plaque Distribution and Vascular Geometry.

J Atheroscler Thromb 2019 Nov 27;26(11):1007-1014. Epub 2019 Mar 27.

Department of Radiology, Hanyang University Hospital.

Aim: Development of atherosclerotic plaques is affected by vascular geometry and hemodynamics. Hemodynamics in the basilar artery (BA) is unique as the flow converges from vertebral arteries (VAs). Here, we investigated the characteristics of BA plaque based on VA and BA geometry.

Methods: Consecutive patients evaluated using high-resolution magnetic resonance imaging (MRI) at a general health center were screened. Geometric characteristics of VA (VA dominancy and VA-BA angles) and BA (BA convexity and BA angles) were assessed. The burden of BA plaques was investigated in each wall (anterior, posterior, left, and right lateral). The characteristics of BA plaques were compared according to VA dominancy (right vs. left), BA angle of lateral view (lateral mid-BA angle; dichotomized), and total plaque burden (divided by tertiles).

Results: Of the 1029 subjects, BA plaques were observed in 98 (9.5%) patients, and were more frequently located at the anterior wall (32.4%) and posterior wall (35.0%) than the right wall (15.3%) and left lateral wall (17.6%). Right and left lateral plaques were more frequent in the left and right convex BA, respectively (p=0.009 and p=0.024, respectively). Anterior plaques were more frequently observed in low lateral mid-BA angle (p= 0.043). BA plaques were predominant in anterior and posterior walls in patients with lower plaque burden, whereas they were predominant in right and left lateral walls in patients with higher plaque burden (p=0.001 and p=0.025, respectively).

Conclusions: Asymptomatic BA plaque location was associated with BA convexity and lateral mid-BA angle. The anteriorly and posteriorly located BA plaques may extend to the lateral walls as the plaque burden increases.
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http://dx.doi.org/10.5551/jat.47365DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6845693PMC
November 2019

Correction to: Cerebrolysin for the Treatment of Aneurysmal Subarachnoid Hemorrhage in Adults: A Retrospective Chart Review.

Adv Ther 2019 Jun;36(6):1509

Department of Neurosurgery, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.

Unfortunately the funding information is incorrect in the published article.
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http://dx.doi.org/10.1007/s12325-019-00930-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6824374PMC
June 2019

Shape and Color Switchable Block Copolymer Particles by Temperature and pH Dual Responses.

ACS Nano 2019 04 18;13(4):4230-4237. Epub 2019 Mar 18.

Department of Chemical and Biomolecular Engineering , Korea Advanced Institute of Science and Technology , Daejeon 34141 , Republic of Korea.

Herein, we report a simple and robust strategy for preparing dual-responsive shape-switchable block copolymer (BCP) particles, which respond to subtle temperature and pH changes near physiological conditions (i.e., human body temperature and neutral pH). The shape transition of polystyrene- b-poly(4-vinylpyridine) BCP particles between lens and football shapes occurs in very narrow temperature and pH ranges: no temperature-based transition for pH 6.0, 40-50 °C transition for pH 6.5, and 25-35 °C for pH 7.0. To achieve these shape transitions, temperature/pH-responsive polymer surfactants of poly( N-(2-(diethylamino)ethyl)acrylamide- r- N-isopropylacrylamide) are designed to induce dramatic changes in relative solubility and their location in response to temperature and pH changes near physiological conditions. In addition, the BCP particles exhibit reversible shape-transforming behavior according to orthogonal temperature and pH changes. Colorimetric measurements of temperature and pH changes are enabled by shape-transforming properties combined with selective positioning of dyes, suggesting promising potential for these particles in clinical and biomedical applications.
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http://dx.doi.org/10.1021/acsnano.8b09276DOI Listing
April 2019

Carotid Artery Stenting and Intracranial Thrombectomy for Tandem Cervical and Intracranial Artery Occlusions.

Neurosurgery 2020 02;86(2):213-220

Department of Neurology, Chonbuk National University Medical School and Hospital, Jeonju, Republic of Korea.

Background: It remains controversial whether carotid artery stenting (CAS) is needed in cases of tandem cervical internal carotid artery occlusion (cICAO) and intracranial large vessel occlusion (LVO).

Objective: To investigate the efficacy and safety of CAS in combination with endovascular thrombectomy (CAS-EVT) in cICAO-LVO patients and to compare its outcomes with those of EVT without CAS (EVT-alone).

Methods: We identified all patients who underwent EVT for tandem cICAO-LVO from the prospectively maintained registries of 17 stroke centers. Patients were classified into 2 groups: CAS-EVT and EVT-alone. Clinical characteristics and procedural and clinical outcomes were compared between 2 groups. We tested whether CAS-EVT strategy was independently associated with recanalization success.

Results: Of the 955 patients who underwent EVT, 75 patients (7.9%) had cICAO-LVO. Fifty-six patients underwent CAS-EVT (74.6%), and the remaining 19 patients underwent EVT-alone (25.4%). The recanalization (94.6% vs 63.2%, P = .002) and good outcome rates (64.3% vs 26.3%, P = .007) were significantly higher in the CAS-EVT than in the EVT-alone. Mortality was significantly lower in the CAS-EVT (7.1% vs 21.6%, P = .014). There was no significant difference in the rate of symptomatic intracranial hemorrhage between 2 groups (10.7 vs 15.8%; P = .684) and according to the use of glycoprotein IIb/IIIa inhibitor (10.0% vs 12.3%; P = .999) or antiplatelet medications (10.2% vs 18.8%; P = .392). CAS-EVT strategy remained independently associated with recanalization success (odds ratio: 24.844; 95% confidence interval: 1.445-427.187).

Conclusion: CAS-EVT strategy seemed to be effective and safe in cases of tandem cICAO-LVO. CAS-EVT strategy was associated with recanalization success, resulting in better clinical outcome.
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http://dx.doi.org/10.1093/neuros/nyz026DOI Listing
February 2020

Need for rescue treatment and its implication: stent retriever versus contact aspiration thrombectomy.

J Neurointerv Surg 2019 Oct 6;11(10):979-983. Epub 2019 Mar 6.

Department of Radiology, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Yangsan, South Korea.

Backgroud: The need for rescue treatment (RT) may differ depending on first-line modality (stent retriever (SR) or contact aspiration (CA)) in endovascular thrombectomy (EVT). We aimed to investigate whether the type of first-line modality in EVT was associated with the need for RT.

Methods: We identified all patients who underwent EVT for anterior circulation large-vessel occlusion from prospectively maintained registries of 17 stroke centers. Patients were dichotomized into SR-first and CA-first. RT involved switching to the other device, balloon angioplasty, permanent stenting, thrombolytics, glycoprotein IIb/IIIa antagonist, or any combination of these. We compared clinical characteristics, procedural details, and final recanalization rate between the two groups and assessed whether first-line modality type was associated with RT requirement and if this affected clinical outcome.

Results: A total of 955 patients underwent EVT using either SR-first (n=526) or CA-first (n=429). No difference occurred in the final recanalization rate between SR-first (82.1%) and CA-first (80.2%). However, recanalization with the first-line modality alone and first-pass recanalization rates were significantly higher in SR-first than in CA-first. CA-first had more device passes and higher RT rate. The RT group had significantly longer puncture-to-recanalization time (93±48 min versus 53±28 min). After adjustment, CA-first remained associated with RT (OR, 1.367; 95% CI, 1.019 to 1.834). RT was negatively associated with good outcome (OR, 0.597; 95% CI, 0.410 to 0.870).

Conclusion: CA was associated with requiring RT, while recanalization with first-line modality alone and first-pass recanalization rates were higher with SR. RT was negatively associated with good outcome.
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http://dx.doi.org/10.1136/neurintsurg-2018-014696DOI Listing
October 2019

Effects of orthopedic treatment using temporomandibular joint balancing appliance (TBA) at improving the symptoms of tic/Tourette syndrome: case report.

Integr Med Res 2018 Dec 27;7(4):381-386. Epub 2018 Jun 27.

KM Fundamental Research Division, Korea Institute of Oriental Medicine, Daejeon, Korea.

Tic disorder is characterized as sudden, non-rhythmic, involuntary and repetitive movement or vocalization, and its onset occurs mainly in childhood or adolescence. The development of medication has been limited because of a lack of understanding of tic mechanisms, and behavioral treatment is recommended as a first-line treatment. In this case report, we observed three cases in which tic disorder or Tourette syndrome was treated with intraoral orthopedic treatment (FCST) combined with acupuncture and an herbal formula and was assessed using the Yale Global Tic Severity Scale (YGTSS), a visual analog scale (VAS) and video analysis. The symptoms were reduced in 30 days and remained at the reduced level until 240 or 300 days after the first day of treatment. Most of the symptoms were disappeared after 240-300 days. Therefore, we could conclude that orthopedic treatment combined with Korean medicine may be applied for tic disorder in accordance with the efficacy and low adverse event rate, and we also suggests a large-scale clinical report to provide concrete evidence before the global application.
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http://dx.doi.org/10.1016/j.imr.2018.06.003DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6303529PMC
December 2018

Effect of balloon guide catheter utilization on contact aspiration thrombectomy.

J Neurosurg 2018 Nov 1:1-7. Epub 2018 Nov 1.

9Department of Radiology, CHA Bundang Medical Center, CHA University, Seongnam, South Korea.

OBJECTIVEThe role of the balloon guide catheter (BGC) has not been evaluated in contact aspiration thrombectomy (CAT) for acute stroke. Here, the authors aimed to test whether the BGC was associated with recanalization success and good functional outcome in CAT.METHODSAll patients who had undergone CAT as the first-line treatment for anterior circulation intracranial large vessel occlusion were retrospectively identified from prospectively maintained registries for six stroke centers. The patients were dichotomized into BGC utilization and nonutilization groups. Clinical findings, procedural details, and recanalization success rates were compared between the two groups. Whether the BGC was associated with recanalization success and functional outcome was assessed.RESULTSA total of 429 patients (mean age 68.4 ± 11.4 years; M/F ratio 215:214) fulfilled the inclusion criteria. A BGC was used in 45.2% of patients. The overall recanalization and good outcome rates were 80.2% and 52.0%, respectively. Compared to the non-BGC group, the BGC group had a significantly reduced number of CAT passes (2.6 ± 1.6 vs 3.4 ± 1.5), shorter puncture-to-recanalization time (56 ± 27 vs 64 ± 35 minutes), lower need for the additional use of thrombolytics (1.0% vs 8.1%), and less embolization to a distal or different site (0.5% vs 3.4%). The BGC group showed significantly higher final (89.2% vs 72.8%) and first-pass (24.2% vs 8.1%) recanalization success rates. After adjustment for potentially associated factors, BGC utilization remained independently associated with recanalization (OR 4.171, 95% CI 1.523-11.420) and good functional outcome (OR 2.103, 95% CI 1.225-3.612).CONCLUSIONSBGC utilization significantly increased the final and first-pass recanalization rates and remained independently associated with recanalization success and good functional outcome.
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http://dx.doi.org/10.3171/2018.6.JNS181045DOI Listing
November 2018

Minimising oxygen contamination through a liquid copper-aided group IV metal production process.

Sci Rep 2018 Nov 26;8(1):17391. Epub 2018 Nov 26.

Alkane Resources Ltd, 89 Burswood Road, Perth, Western Australia, 6100, Australia.

This paper demonstrates for the first time the fabrication of Zr-Cu alloy ingots from a Hf- free ZrO precursor in a molten CaCl medium to recover nuclear-grade Zr. The reduction of ZrO in the presence of CaO was accelerated by the formation of Ca metal in the intermediate stage of the process. Tests conducted with various amounts of ZrO indicate that the ZrO was reduced to the metallic form at low potentials applied at the cathode, and the main part of the zirconium was converted to a CuZr alloy with a different composition. The maximum oxygen content values in the CuZr alloy and Zr samples upon using liquid Cu were less than 300 and 891 ppm, respectively. However, Al contamination was observed in the CuZr during the electroreduction process. In order to solve the Al contamination problem, the fabrication process of CuZr was performed using the metallothermic reduction process, and the produced CuZr was used for electrorefining. The CuZr alloy was further purified by a molten salt electrorefining process to recover pure nuclear-grade Zr in a LiF-BaZrF-based molten salt, the latter of which was fabricated from a waste pickling acid of a Zr clad tube. After the electrorefining process, the recovered Zr metal was fabricated into nuclear-grade Zr buttons through arc melting following a salt distillation process. The results suggest that the removal of oxygen from the reduction product is a key reason for the use of a liquid CaCu reduction agent.
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http://dx.doi.org/10.1038/s41598-018-35739-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6255757PMC
November 2018

Relationship between cerebral microbleeds and white matter MR hyperintensities in systemic lupus erythematosus: a retrospective observational study.

Neuroradiology 2019 Mar 10;61(3):265-274. Epub 2018 Nov 10.

Department of Neuropsychiatry, Seoul National University Bundang Hospital, Seongnam, Republic of Korea.

Purpose: White matter hyperintensities (WMH) and cerebral microbleeds (CMBs) are known to be associated with small vessel diseases (SVD) and neuroinflammation. The purpose was to investigate the relationship between CMBs and WMH in patients with systemic lupus erythematosus (SLE).

Methods: Thirty-one SLE patients with WMH and 27 SLE patients with normal brain MRI were compared. The presence, location, and grading of CMBs were assessed using susceptibility-weighted images. WMH volume was quantitatively measured. Clinical characteristics and serologic markers were compared. We also performed two separate subgroup analyses after (1) dividing WMH into inflammatory lesion vs. SVD subgroups and (2) dividing WMH into those with vs. without CMB subgroups.

Results: The WMH group showed more frequent CMBs than the normal MR group (p < 0.001). The WMH group showed higher SLE disease activity index, longer disease duration, and a higher incidence of antiphospholipid syndrome than the normal MR group (p = 0.02, 0.04, and 0.04, respectively). There was a moderate correlation between WMH volume and CMB grading (r = 0.49, p = 0.006). Within the WMH group, the inflammatory lesion subgroup showed more frequent CMBs and larger WMH volume than the SVD subgroup (p < 0.001 and 0.02, respectively). The WMH with CMB subgroup had larger WMH volume than the WMH without CMB subgroup (p = 0.004).

Conclusion: In patients with SLE, CMBs could be related to large-volume WMH and inflammatory lesions. CMBs along with severe WMH could be used as an imaging biomarker of vasculitis in patients with SLE.
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http://dx.doi.org/10.1007/s00234-018-2130-1DOI Listing
March 2019

Cerebrolysin for the Treatment of Aneurysmal Subarachnoid Hemorrhage in Adults: A Retrospective Chart Review.

Adv Ther 2018 12 9;35(12):2224-2235. Epub 2018 Nov 9.

Department of Neurosurgery, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.

Introduction: Cerebrolysin is a neuroprotective drug used in the treatment of acute ischemic stroke. To our knowledge, this drug has never been evaluated in patients with aneurysmal subarachnoid hemorrhage (SAH). The aim of this study was to evaluate the effect of Cerebrolysin in patients with aneurysmal SAH.

Methods: Aneurysmal SAH patients who had their aneurysm obliterated at our institution from 2007 to 2016 were retrospectively studied. Patients received Cerebrolysin treatment or standard care only (control group). Subgroup analyses were performed according to Hunt and Hess grade (good grade ≤ 2, N = 216; poor grade ≥ 3, N = 246) and treatment procedure (clip or coil).

Results: In good-grade patients (N = 216), clinical outcomes and mortality did not differ significantly between the control and Cerebrolysin groups. In poor-grade patients (N = 246), the mortality rate was significantly lower in the Cerebrolysin group (8.7%) than in the control group (25.4%, p = 0.006). In patients who received microsurgical clipping (N = 328), the mortality rate was significantly lower in the Cerebrolysin group (7.3%) than in the control group (18.5%, p = 0.016).

Conclusion: Cerebrolysin injection during the acute period of SAH appeared to reduce the mortality rate, especially in poor-grade patients. This study suggests the potential of Cerebrolysin for treating aneurysmal SAH. Further studies are needed to confirm our results.
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http://dx.doi.org/10.1007/s12325-018-0832-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6822868PMC
December 2018

Number of Stent Retriever Passes Associated With Futile Recanalization in Acute Stroke.

Stroke 2018 09;49(9):2088-2095

Neurology (B.-S.S.).

Background and Purpose- Stent retriever (SR) thrombectomy has become the mainstay of treatment of acute intracranial large artery occlusion. However, it is still not much known about the optimal limit of SR attempts for favorable outcome. We evaluated whether a specific number of SR passes for futile recanalization can be determined. Methods- Patients who were treated with a SR as the first endovascular modality for their intracranial large artery occlusion in anterior circulation were retrospectively reviewed. The recanalization rate for each SR pass was calculated. The association between the number of SR passes and a patient's functional outcome was analyzed. Results- A total of 467 patients were included. Successful recanalization by SR alone was achieved in 82.2% of patients. Recanalization rates got sequentially lower as the number of passes increased, and the recanalization rate achievable by ≥5 passes of the SR was 5.5%. In a multivariable analysis, functional outcomes were more favorable in patients with 1 to 4 passes of the SR than in patients without recanalization (odds ratio [OR] was 8.06 for 1 pass; OR 7.78 for 2 passes; OR 6.10 for 3 passes; OR 6.57 for 4 passes; all P<0.001). However, the functional outcomes of patients with ≥5 passes were not significantly more favorable than found among patients without recanalization (OR 1.70 with 95% CI, 0.42-6.90 for 5 passes, P=0.455; OR 0.33 with 0.02-5.70, P=0.445 for ≥6 passes). Conclusions- The likelihood of successful recanalization got sequentially lower as the number of SR passes increased. Five or more passes of the SR became futile in terms of the recanalization rate and functional outcomes.
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http://dx.doi.org/10.1161/STROKEAHA.118.021320DOI Listing
September 2018

A feasibility study of laparoscopic total gastrectomy for clinical stage I gastric cancer: a prospective multi-center phase II clinical trial, KLASS 03.

Gastric Cancer 2019 01 20;22(1):214-222. Epub 2018 Aug 20.

Department of Surgery, Soonchunhyang University College of Medicine, 170-Jomaru-ro, Bucheon-si, Gyeonggi-do, South Korea.

Background: With improved short-term surgical outcomes, laparoscopic distal gastrectomy has rapidly gained popularity. However, the safety and feasibility of laparoscopic total gastrectomy (LTG) has not yet been proven due to the difficulty of the technique. This single-arm prospective multi-center study was conducted to evaluate the use of LTG for clinical stage I gastric cancer.

Methods: Between October 2012 and January 2014, 170 patients with pathologically proven, clinical stage I gastric adenocarcinoma located at the proximal stomach were enrolled. Twenty-two experienced surgeons from 19 institutions participated in this clinical trial. The primary end point was the incidence of postoperative morbidity and mortality at postoperative 30 days. The severity of postoperative complications was categorized according to Clavien-Dindo classification, and the incidence of postoperative morbidity and mortality was compared with that in a historical control.

Results: Of the enrolled patients, 160 met criteria for inclusion in the full analysis set. Postoperative morbidity and mortality rates reached 20.6% (33/160) and 0.6% (1/160), respectively. Fifteen patients (9.4%) had grade III or higher complications, and three reoperations (1.9%) were performed. The incidence of morbidity after LTG in this trial did not significantly differ from that reported in a previous study for open total gastrectomy (18%).

Conclusions: LTG performed by experienced surgeons showed acceptable postoperative morbidity and mortality for patients with clinical stage I gastric cancer.
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http://dx.doi.org/10.1007/s10120-018-0864-4DOI Listing
January 2019

Predicting factors for shunt-dependent hydrocephalus in patients with aneurysmal subarachnoid hemorrhage.

Acta Neurochir (Wien) 2018 07 15;160(7):1407-1413. Epub 2018 May 15.

Department of Anesthesiology and Pain Medicine, Hanyang University Medical Center, Seoul, South Korea.

Background: Chronic hydrocephalus after aneurysmal subarachnoid hemorrhage (SAH) is a major complication that leads to a medical burden and poor clinical outcomes. The aim of this study was to evaluate the predictive factors of shunt-dependent hydrocephalus focusing on postoperative fever and infection.

Method: A total of 418 patients were included in this study and the patient demographic features, radiologic findings, days of fever burden, and infection were compared between the shunt (n = 72) and no shunt group (n = 346). Days of fever burden was defined as the total number of days with the highest body temperature ≥ 38.0 °C each day from day 1 to day 14. Pneumonia, urinary tract infection (UTI), meningitis, and bacteremia were recorded in all patients.

Results: The independent predictive factors for shunt-dependent hydrocephalus were older age ≥ 65, microsurgical clipping, placement of extraventricular drainage (EVD), days of fever burden, and infection. The incidence of shunt dependency was 2.4% in the no fever burden patients (n = 123), 14.9% in the 1-3 days of fever burden patients (n = 161), 27.0% in the 4-6 days of fever burden patients (n = 74), and 41.7% in the ≥ 7 days of fever burden patients with statistical significance among groups (p < 0.001).

Conclusion: The rate of shunt dependency increased proportionally as the days of fever burden increased. Older age (≥ 65), microsurgical clipping, placement of EVD, days of fever burden, and infection were independent predictive factors for shunt dependency. Proper postoperative care for maintaining normal body temperature and preventing infectious disease can help reduce the rate of shunt dependency and improve clinical outcomes.
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http://dx.doi.org/10.1007/s00701-018-3560-6DOI Listing
July 2018

Detection of Dimethyl Methylphosphonate (DMMP) Using Polyhedral Oligomeric Silsesquioxane (POSS).

J Nanosci Nanotechnol 2018 09;18(9):6565-6569

Department of Chemistry and Institute of Basic Science, Sungkyunkwan University, Suwon, 16419, South Korea.

The detection and monitoring of colorless and odorless chemical warfare agents (CWAs) has become important due to the increasing threat of terrorist activities. To enhance the sensitivity and selectivity of CWAs a number of sensing materials have been developed, including the widely used polyvinylidene fluoride (PVDF). However, PVDF is limited by its low sensitivity and selectivity for many CWAs. In this study, polyhedral oligomeric silsesquioxane (POSS) was used as a sensing material for dimethyl methylphosphonate (DMMP) a simulant of sarin nerve gas. Sensitivity, selectivity, and reusability were investigated with an AT-cut 5 MHz quartz crystal microbalance. At room temperature, POSS exhibited a strong response for DMMP vapor at different concentrations from 20 ppm to 120 ppm leading to fast chemical adsorption and desorption. To investigate selectivity the volatile organic compounds (VOCs) ethanol, water, toluene, ACN, methanol, and n-hexane were tested at a fixed flow rate. Targeted VOCs showed lower responses than DMMP as measured with a quartz crystal microbalance (QCM) sensor, demonstrating the high selectivity of the method. POSS can be considered a potentially useful material for sensing nerve simulants.
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http://dx.doi.org/10.1166/jnn.2018.15698DOI Listing
September 2018

Rescue Stenting for Failed Mechanical Thrombectomy in Acute Ischemic Stroke: A Multicenter Experience.

Stroke 2018 04 16;49(4):958-964. Epub 2018 Mar 16.

From the Department of Radiology, Severance Stroke Center, Severance Hospital (Y.C., B.M.K., D.J.K.), Department of Neurology, Severance Stroke Center, Severance Hospital (J.H.H., H.S.N., Y.D.K), and Department of Neurology, Gangnam Severance Hospital (K.-Y.L.), Yonsei University College of Medicine, Seoul, South Korea; Department of Neurology (O.Y.B.) and Department of Radiology (P.J.), Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea; Department of Neurology, National Medical Center, Seoul, South Korea (J.-H.B.); Department of Neurology, Keimyung University School of Medicine, Daegu, South Korea (J.Y.); Department of Radiology, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Yangsan, South Korea (S.K.B., J.R.); Department of Radiology, Gangnam Severance Hospital, Yonsei University, Seoul, South Korea (S.H.S.); Department of Radiology (H.S.K.) and Department of Neurology (B.-S.S.), Chonbuk National University Medical School and Hospital, Jeonju, South Korea; Department of Radiology, Konkuk University Medical Center and School of Medicine, Seoul, South Korea (H.G.R.); Department of Radiology, Hanyang University College of Medicine and Hospital, Seoul, Korea (Y.-J.L.); Department of Radiology, CHA Bundang Medical Center, CHA University, Seongnam, South Korea (S.H.K.); Department of Radiology, Kyung Hee University Hospital at Gangdong, School of Medicine, Kyung Hee University, Seoul, South Korea (C.W.R.); Department of Radiology, St.Vincent's Hospital, College of Medicine, The Catholic University of Korea, Suwon, South Korea (Y.-K.I.); Department of Radiology, Korea University Anam Hospital, Seoul, South Korea (B.K.); Department of Neurosurgery, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, South Korea (H.-J.J.); Department of Radiology, Inje University Ilsan Paik Hospital, Goyang, South Korea (J.W.K.); Department of Radiology (J.S.B., W.J.L.) and Department of Neurology (J.-M.K.), Chung-Ang University Hospital, Seoul, South Korea; Department of Radiology, Korea University College of Medicine, Guro Hospital, Seoul, South Korea (S.S.); and Department of Neurology, Konkuk University Hospital, Konkuk University School of Medicine, Seoul, South Korea (J.J.P.).

Background And Purpose: Effective rescue treatment has not yet been suggested in patients with mechanical thrombectomy (MT) failure. This study aimed to test whether rescue stenting (RS) improved clinical outcomes in MT-failed patients.

Methods: This is a retrospective analysis of the cohorts of the 16 comprehensive stroke centers between September 2010 and December 2015. We identified the patients who underwent MT but failed to recanalize intracranial internal carotid artery or middle cerebral artery M1 occlusion. Patients were dichotomized into 2 groups: patients with RS and without RS after MT failure. Clinical and laboratory findings and outcomes were compared between the 2 groups. It was tested whether RS is associated with functional outcome.

Results: MT failed in 148 (25.0%) of the 591 patients with internal carotid artery or middle cerebral artery M1 occlusion. Of these 148 patients, 48 received RS (RS group) and 100 were left without further treatment (no stenting group). Recanalization was successful in 64.6% (31 of 48 patients) of RS group. Compared with no stenting group, RS group showed a significantly higher rate of good outcome (modified Rankin Scale score, 0-2; 39.6% versus 22.0%; =0.031) without increasing symptomatic intracranial hemorrhage (16.7% versus 20.0%; =0.823) or mortality (12.5% versus 19.0%; =0.360). Of the RS group, patients who had recanalization success had 54.8% of good outcome, which is comparable to that (55.4%) of recanalization success group with MT. RS remained independently associated with good outcome after adjustment of other factors (odds ratio, 3.393; 95% confidence interval, 1.192-9.655; =0.022). Follow-up vascular imaging was available in the 23 (74.2%) of 31 patients with recanalization success with RS. The stent was patent in 20 (87.0%) of the 23 patients. Glycoprotein IIb/IIIa inhibitor was significantly associated with stent patency but not with symptomatic intracranial hemorrhage.

Conclusions: RS was independently associated with good outcomes without increasing symptomatic intracranial hemorrhage or mortality. RS seemed considered in MT-failed internal carotid artery or middle cerebral artery M1 occlusion.
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http://dx.doi.org/10.1161/STROKEAHA.117.020072DOI Listing
April 2018