Publications by authors named "Patrick Kwon"

15 Publications

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Seeing and doing are not believing: Investigating when and how conceptual knowledge impinges on observation and recall of physical motion.

J Exp Psychol Appl 2021 Mar 25. Epub 2021 Mar 25.

Department of Educational Psychology.

One standard pedagogical approach in physical science courses engages students in making predictions about physical phenomena that elicit non-normative expectations, then make observations intended to provide counterevidence that sparks conceptual change. This article presents five experiments investigating conditions where observation and recall are impacted by incorrect expectations and how these theory-laden observational errors might be mitigated. Using the context of balancing, Experiments 1-3 examine how the ambiguity of the stimuli may allow observers to selectively attend to information that is consistent with prior beliefs, while discounting incongruent information. As ambiguity is removed, the biasing effects of conceptual expectations are reduced. Experiments 4 and 5 extend the findings to investigate whether the effect of conceptual expectations also applies to memory of one's own bodily experiences of balancing. The results suggest that the ambiguity-driven, theory-laden observation effects found for visual observation, do not necessarily translate to recall for an embodied action, even though the experience of balancing contained perceptuo-motor ambiguity. Taken altogether, these five experiments show how conceptual knowledge can impinge on accurate recall of observations or embodied experiences and that instruction engaging students with demonstrations or embodied experiences may not necessarily provide intended counterevidence that contradicts prior expectations. (PsycInfo Database Record (c) 2021 APA, all rights reserved).
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http://dx.doi.org/10.1037/xap0000338DOI Listing
March 2021

Hypertrophic Olivary Degeneration and Movement Disorder in a Patient with Familial Creutzfeldt-Jakob Disease.

Cureus 2020 Oct 8;12(10):e10854. Epub 2020 Oct 8.

Department of Neurology, New York University Grossman School of Medicine, New York, USA.

A 38-year-old male presented with a three-week history of bilateral lower extremity choreiform movements. History included sleep abnormalities, rushed and unintelligible speech, with delusions two to six months prior to presentation. He also developed mild dysphagia, staring spells, and anterograde amnesia. On examination, he had pressured speech, asynchronous cycling movements of the bilateral lower extremities persisting during sleep, occasional ballistic movements of the upper extremities, and ataxia. Magnetic resonance imaging (MRI) of the brain showed high cortical signal change in bilateral parieto-occipital cortices with evidence of medullary olive hypertrophy bilaterally. Electroencephalography showed generalized slowing without periodic spikes. Cerebrospinal fluid was positive for protein 14-3-3 and real-time quaking-induced conversion. Genetic testing was positive for autosomal dominant prion protein gene (PRNP) genetic mutation. The patient passed away three months after discharge. This case provides previously undescribed imaging and movement abnormalities in a patient with familial Creutzfeldt-Jakob disease (CJD), and suggests that CJD should not be removed from the differential in patients with these atypical findings.
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http://dx.doi.org/10.7759/cureus.10854DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7652026PMC
October 2020

Keeping the team together: Transformation of an inpatient neurology service at an urban, multi-ethnic, safety net hospital in New York City during COVID-19.

Clin Neurol Neurosurg 2020 10 17;197:106156. Epub 2020 Aug 17.

Division of Neurology, NYU Langone Hospital-Brooklyn, Brooklyn, NY, United States; NYU Grossman School of Medicine, NY, NY United States.

The COVID-19 pandemic dramatically affected the operations of New York City hospitals during March and April of 2020. This article describes the transformation of a neurology division at a 450-bed tertiary care hospital in a multi-ethnic community in Brooklyn during this initial wave of COVID-19. In lieu of a mass redeployment of staff to internal medicine teams, we report a novel method for a neurology division to participate in a hospital's expansion of care for patients with COVID-19 while maintaining existing team structures and their inherent supervisory and interpersonal support mechanisms.
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http://dx.doi.org/10.1016/j.clineuro.2020.106156DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7430288PMC
October 2020

Special considerations in the assessment of catastrophic brain injury and determination of brain death in patients with SARS-CoV-2.

J Neurol Sci 2020 10 8;417:117087. Epub 2020 Aug 8.

NYU Langone Medical Center, Department of Neurology, New York, NY 10016, United States of America; NYU Langone Medical Center, Department of Neurosurgery, New York, NY 10016, United States of America.

Introduction: The coronavirus disease 2019 (Covid-19) pandemic has led to challenges in provision of care, clinical assessment and communication with families. The unique considerations associated with evaluation of catastrophic brain injury and death by neurologic criteria in patients with Covid-19 infection have not been examined.

Methods: We describe the evaluation of six patients hospitalized at a health network in New York City in April 2020 who had Covid-19, were comatose and had absent brainstem reflexes.

Results: Four males and two females with a median age of 58.5 (IQR 47-68) were evaluated for catastrophic brain injury due to stroke and/or global anoxic injury at a median of 14 days (IQR 13-18) after admission for acute respiratory failure due to Covid-19. All patients had hypotension requiring vasopressors and had been treated with sedative/narcotic drips for ventilator dyssynchrony. Among these patients, 5 had received paralytics. Apnea testing was performed for 1 patient due to the decision to withdraw treatment (n = 2), concern for inability to tolerate testing (n = 2) and observation of spontaneous respirations (n = 1). The apnea test was aborted due to hypoxia and hypotension. After ancillary testing, death was declared in three patients based on neurologic criteria and in three patients based on cardiopulmonary criteria (after withdrawal of support (n = 2) or cardiopulmonary arrest (n = 1)). A family member was able to visit 5/6 patients prior to cardiopulmonary arrest/discontinuation of organ support.

Conclusion: It is feasible to evaluate patients with catastrophic brain injury and declare brain death despite the Covid-19 pandemic, but this requires unique considerations.
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http://dx.doi.org/10.1016/j.jns.2020.117087DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7414304PMC
October 2020

BTEX and heavy metals removal using pulverized waste tires in engineered fill materials.

Chemosphere 2020 Mar 2;242:125281. Epub 2019 Nov 2.

Department of Environment and Energy, Sejong University, Seoul, South Korea. Electronic address:

In this study, the potential of pulverized waste tires (PWTs), either on their own or mixed with soil (well graded sand), to act as adsorptive fill materials was evaluated by conducting laboratory tests for accessing their adsorption and geotechnical properties. PWT (0, 5, 10, 15, 25, and 100 wt%) was mixed with soil to evaluate the removal of benzene, toluene, ethylbenzene, and xylene (BTEX) components and two heavy metal ions (Pb and Cu). Adsorption batch tests were performed to determine the equilibrium sorption capacity of each mixture. Subsequently, compaction, direct shear, and consolidation tests were performed to establish their geotechnical properties. The results showed that BTEX had the strongest affinity based on the uptake capacity by the soil-PWT mixtures. The adsorption of BTEX increased for greater PWT content, with pure PWT having the highest adsorption capacity toward BTEX removal: uptake capacities for xylene, ethylbenzene, toluene, and benzene were 526, 377, 207 and 127 μg/g sorbent, respectively. Heavy metal removal was increased by increasing the amount of PWT up to 10 wt%, and then decreased beyond this ratio. Compacted soil-PWT mixtures comprising 5-25 wt% PWT have relatively low dry unit weight, low compressibility, adequate shear capacity for many load-bearing field applications, and satisfactory adsorption of organic/inorganic contaminants, such that they could also be used as adsorptive fill materials.
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http://dx.doi.org/10.1016/j.chemosphere.2019.125281DOI Listing
March 2020

A Binder Jet Printed, Stainless Steel Preconcentrator as an In-Line Injector of Volatile Organic Compounds.

Sensors (Basel) 2019 Jun 19;19(12). Epub 2019 Jun 19.

Department of Mechanical Engineering, Michigan State University, East Lansing, MI 48824, USA.

A conventional approach to making miniature or microscale gas chromatography (GC) components relies on silicon as a base material and MEMS fabrication as manufacturing processes. However, these devices often fail in medium-to-high temperature applications due to a lack of robust fluidic interconnects and a high-yield bonding process. This paper explores the feasibility of using metal additive manufacturing (AM), which is also known as metal 3D printing, as an alternative platform to produce small-scale microfluidic devices that can operate at a temperature higher than that which polymers can withstand. Binder jet printing (BJP), one of the metal AM processes, was utilized to make stainless steel (SS) preconcentrators (PCs) with submillimeter internal features. PCs can increase the concentration of gaseous analytes or serve as an inline injector for GC or gas sensor applications. Normally, parts printed by BJP are highly porous and thus often infiltrated with low melting point metal. By adding to SS316 powder sintering additives such as boron nitride (BN), which reduces the liquidus line temperature, we produce near full-density SS PCs at sintering temperatures much lower than the SS melting temperature, and importantly without any measurable shape distortion. Conversely, the SS PC without BN remains porous after the sintering process and unsuitable for fluidic applications. Since the SS parts, unlike Si, are compatible with machining, they can be modified to work with commercial compression fitting. The PC structures as well as the connection with the fitting are leak-free with relatively high operating pressures. A flexible membrane heater along with a resistance-temperature detector is integrated with the SS PCs for thermal desorption. The proof-of-concept experiment demonstrates that the SS PC can preconcentrate and inject 0.6% headspace toluene to enhance the detector's response.
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http://dx.doi.org/10.3390/s19122748DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6630219PMC
June 2019

Subclavian steal syndrome due to dialysis fistula corrected with subclavian artery stenting.

Neurol Clin Pract 2018 Oct;8(5):e23-e25

Departments of Neurology (SA, PK, GS, JF, KA, AT) and Internal Medicine (LS), NYU Langone Health-Brooklyn, NY.

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http://dx.doi.org/10.1212/CPJ.0000000000000510DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6276325PMC
October 2018

Immune Myopathy With Perimysial Pathology Associated With Interstitial Lung Disease and Anti-EJ Antibodies.

J Clin Neuromuscul Dis 2017 Jun;18(4):223-227

*Neuromuscular Division, Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY; and †Division of Rheumatology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY.

Objectives: We report a case of immune myopathy with perimysial pathology associated with anti-glycyl-transfer RNA synthetase (anti-EJ) antibody and an excellent treatment response.

Methods: Chart review.

Results: A 36-year-old woman presented with 3 months of fatigue, weight loss, progressive weakness in a scapuloperoneal distribution, and dysphagia. Nerve conduction studies, electromyography, and ultrasound suggested an irritable myopathy. She had marked elevations of creatine kinase and positive anti-glycyl-transfer RNA synthetase (anti-EJ) antibodies. A left biceps muscle biopsy revealed inflammation of the perimysium and surrounding perimysial blood vessels with focal fragmentation of the perimysium. Further evaluation revealed interstitial lung disease. Treatment with prednisone and mycophenolate mofetil led to marked clinical improvement of her symptoms.

Conclusions: Our case adds to the growing spectrum of inflammatory myopathies and highlights the importance of performing a comprehensive, multisystem workup.
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http://dx.doi.org/10.1097/CND.0000000000000148DOI Listing
June 2017

3D printed metal molds for hot embossing plastic microfluidic devices.

Lab Chip 2017 01;17(2):241-247

Department of Mechanical Engineering, Michigan State University, East Lansing, MI, USA.

Plastics are one of the most commonly used materials for fabricating microfluidic devices. While various methods exist for fabricating plastic microdevices, hot embossing offers several unique advantages including high throughput, excellent compatibility with most thermoplastics and low start-up costs. However, hot embossing requires metal or silicon molds that are fabricated using CNC milling or microfabrication techniques which are time consuming, expensive and required skilled technicians. Here, we demonstrate for the first time the fabrication of plastic microchannels using 3D printed metal molds. Through optimization of the powder composition and processing parameters, we were able to generate stainless steel molds with superior material properties (density and surface finish) than previously reported 3D printed metal parts. Molds were used to fabricate poly(methyl methacrylate) (PMMA) replicas which exhibited good feature integrity and replication quality. Microchannels fabricated using these replicas exhibited leak-free operation and comparable flow performance as those fabricated from CNC milled molds. The speed and simplicity of this approach can greatly facilitate the development (i.e. prototyping) and manufacture of plastic microfluidic devices for research and commercial applications.
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http://dx.doi.org/10.1039/c6lc01430eDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5706547PMC
January 2017

Fully-Enclosed Ceramic Micro-burners Using Fugitive Phase and Powder-based Processing.

Sci Rep 2016 08 22;6:31336. Epub 2016 Aug 22.

Department of Mechanical Engineering, Michigan State University, East Lansing, MI, USA.

Ceramic-based microchemical systems (μCSs) are more suitable for operation under harsh environments such as high temperature and corrosive reactants compared to the more conventional μCS materials such as silicon and polymers. With the recent renewed interests in chemical manufacturing and process intensification, simple, inexpensive, and reliable ceramic manufacturing technologies are needed. The main objective of this paper is to introduce a new powder-based fabrication framework, which is a one-pot, cost-effective, and versatile process for ceramic μCS components. The proposed approach employs the compaction of metal-oxide sub-micron powders with a graphite fugitive phase that is burned out to create internal cavities and microchannels before full sintering. Pure alumina powder has been used without any binder phase, enabling more precise dimensional control and less structure shrinkage upon sintering. The key process steps such as powder compaction, graphite burnout during partial sintering, machining in a conventional machine tool, and final densification have been studied to characterize the process. This near-full density ceramic structure with the combustion chamber and various internal channels was fabricated to be used as a micro-burner for gas sensing applications.
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http://dx.doi.org/10.1038/srep31336DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4992868PMC
August 2016

Cerebral Vascular Malformations and Headache.

Headache 2015 Sep 8;55(8):1133-42. Epub 2015 Aug 8.

Hartford Healthcare Headache Center, West Hartford, CT, USA.

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http://dx.doi.org/10.1111/head.12639DOI Listing
September 2015

Adult stem cells from the hyaluronic acid-rich node and duct system differentiate into neuronal cells and repair brain injury.

Stem Cells Dev 2014 Dec 18;23(23):2831-40. Epub 2014 Aug 18.

1 Cancer Immunology Branch, National Cancer Center , Ilsan, Gyeonggi, Korea.

The existence of a hyaluronic acid-rich node and duct system (HAR-NDS) within the lymphatic and blood vessels was demonstrated previously. The HAR-NDS was enriched with small (3.0-5.0 μm in diameter), adult stem cells with properties similar to those of the very small embryonic-like stem cells (VSELs). Sca-1(+)Lin(-)CD45(-) cells were enriched approximately 100-fold in the intravascular HAR-NDS compared with the bone marrow. We named these adult stem cells "node and duct stem cells (NDSCs)." NDSCs formed colonies on C2C12 feeder layers, were positive for fetal alkaline phosphatase, and could be subcultured on the feeder layers. NDSCs were Oct4(+)Nanog(+)SSEA-1(+)Sox2(+), while VSELs were Oct4(+)Nanog(+)SSEA-1(+)Sox2(-). NDSCs had higher sphere-forming efficiency and proliferative potential than VSELs, and they were found to differentiate into neuronal cells in vitro. Injection of NDSCs into mice partially repaired ischemic brain damage. Thus, we report the discovery of potential adult stem cells that may be involved in tissue regeneration. The intravascular HAR-NDS may serve as a route that delivers these stem cells to their target tissues.
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http://dx.doi.org/10.1089/scd.2014.0142DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4235983PMC
December 2014

4-1BB functions as a survival factor in dendritic cells.

J Immunol 2009 Apr;182(7):4107-15

R&D Center for Cancer Therapeutics, National Cancer Center, Ilsan, Korea.

4-1BB (CD137) is expressed on dendritic cells (DCs) and its biological function has remained largely unresolved. By comparing 4-1BB-intact (4-1BB(+/+)) and 4-1BB-deficient (4-1BB(-/-)) DCs, we found that 4-1BB was strongly induced on DCs during the maturation and that DC maturation was normal in the absence of 4-1BB. However, DC survival rate was low in the absence of 4-1BB, which was due to the decreased Bcl-2 and Bcl-x(L) in 4-1BB(-/-) DCs compared with 4-1BB(+/+) DCs after DC maturation. Consistent with these results, 4-1BB(-/-) DCs showed an increased turnover rate in steady state and more severely decreased in spleen by injecting LPS compared with 4-1BB(+/+) DCs. When OVA-pulsed DCs were adoptively transferred to recipient mice along with OVA-specific CD4(+) T cells, 4-1BB(-/-) DCs did not properly migrate to the T cell zone in lymph nodes and poorly induced proliferation of CD4(+) T cells, although both DCs comparably expressed functional CCR7. Eventually, 4-1BB(-/-) DCs generated a reduced number of OVA-specific memory CD4(+) T cells compared with 4-1BB(+/+) DCs. To further assess the role of 4-1BB on DC longevity in vivo, 4-1BB(+/+) and 4-1BB(-/-) C57BL/6 were administrated with Propionibacterium acnes that develop liver granuloma by recruiting DCs. Number and size of granuloma were reduced in the absence of 4-1BB, but the inflammatory cytokine level was comparable between the mice, which implied that the granuloma might be reduced due to the decreased longevity of DCs. These results demonstrate that 4-1BB on DCs controls the duration, DC-T interaction, and, therefore, immunogenicity.
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http://dx.doi.org/10.4049/jimmunol.0800459DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2681223PMC
April 2009

4-1BB triggers IL-13 production from T cells to limit the polarized, Th1-mediated inflammation.

J Leukoc Biol 2007 Jun 27;81(6):1455-65. Epub 2007 Mar 27.

The Immunomodulation Research Center, University of Ulsan, San29, Mukeo-Dong, Nam-Ku, Ulsan, Korea 680-749.

4-1BB (CD137) triggering typically induces Th1 response by increasing IFN-gamma from T cells upon TCR ligation. We found recently that 4-1BB costimulation increased the expression of IL-13 from CD4(+) T cells, as well as CD8(+) T cells. The enhanced IL-13 expression by agonistic anti-4-1BB treatment was mediated via MAPK1/2, PI-3K, JNK, mammalian target of rapamycin, NF-AT, and NF-kappaB signaling pathways. The signaling for IL-13 induction was similar to that of IFN-gamma production by anti-4-1BB treatment in T cells. When the anti-4-1BB-mediated IL-13 expression was tested in an in vivo viral infection model such as HSV-1 and vesicular stomatitis virus, 4-1BB stimulation enhanced IL-13 expression of CD4(+) T, rather than CD8(+) T cells. Although IL-13 was enhanced by anti-4-1BB treatment, the increased IL-13 did not significantly alter the anti-4-1BB-induced Th1 polarization of T cells--increase of T-bet and decrease of GATA-3. Nevertheless, anti-4-1BB treatment polarized T cells excessively in the absence of IL-13 and even became detrimental to the mice by causing liver inflammation. Therefore, we concluded that IL-13 was coinduced following 4-1BB triggering to maintain the Th1/2 balance of immune response.
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http://dx.doi.org/10.1189/jlb.1006619DOI Listing
June 2007

Blockade of the 4-1BB (CD137)/4-1BBL and/or CD28/CD80/CD86 costimulatory pathways promotes corneal allograft survival in mice.

Immunology 2007 Jul 22;121(3):349-58. Epub 2007 Mar 22.

LSU Eye Center, LSU Health Sciences Center School of Medicine, New Orleans, LA, USA.

To explore the roles of 4-1BB (CD137) and CD28 in corneal transplantation, we examined the effect of 4-1BB/4-1BB ligand (4-1BBL) and/or CD28/CD80/CD86 blockade on corneal allograft survival in mice. Allogeneic corneal transplantation was performed between two strains of wild-type (WT) mice, BALB/c and C57BL/6 (B6), and between BALB/c and B6 WT donors and various gene knockout (KO) recipients. Some of the WT graft recipients were treated intraperitoneally with agonistic anti-4-1BB or blocking anti-4-1BBL monoclonal antibody (mAb) on days 0, 2, 4 and 6 after transplantation. Transplanted eyes were observed over a 13-week period. Allogeneic grafts in control WT B6 and BALB/c mice treated with rat immunoglobulin G showed median survival times (MST) of 12 and 14 days, respectively. Allogeneic grafts in B6 WT recipients treated with anti-4-1BB mAb showed accelerated rejection, with an MST of 8 days. In contrast, allogeneic grafts in BALB/c 4-1BB/CD28 KO and B6 CD80/CD86 KO recipients had significantly prolonged graft survival times (MST, 52.5 days and 36 days, respectively). Treatment of WT recipients with anti-4-1BB mAb resulted in enhanced cellular proliferation in the mixed lymphocyte reaction and increased the numbers of CD4(+) CD8(+) T cells, and macrophages in the grafts, which correlated with decreased graft survival time, whereas transplant recipients with costimulatory receptor deletion showed longer graft survival times. These results suggest that the absence of receptors for the 4-1BB/4-1BBL and/or CD28/CD80/CD86 costimulatory pathways promotes corneal allograft survival, whereas triggering 4-1BB with an agonistic mAb enhances the rejection of corneal allografts.
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http://dx.doi.org/10.1111/j.1365-2567.2007.02581.xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2265952PMC
July 2007