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1.
Inorg Chem ; 57(14): 8299-8306, 2018 Jul 16.
Article in English | MEDLINE | ID: mdl-29952559

ABSTRACT

The electrochemical reduction of trivalent samarium in a LiCl-KCl eutectic melt produced highly stable divalent samarium, whose electrochemical properties and electronic structure in the molten salt were investigated using cyclic voltammetry, UV-vis absorption spectroscopy, laser-induced emission spectroscopy, and density functional theory (DFT) calculations. Diffusion coefficients of Sm2+ and Sm3+ were electrochemically measured to be 0.92 × 10-5 and 1.10 × 10-5 cm2/s, respectively, and the standard apparent potential of the Sm2+/3+ couple was estimated to be -0.82 V vs Ag|Ag+ at 450 °C. The spectroelectrochemical study demonstrated that the redox behavior of the samarium cations obeys the Nernst equation ( E°' = -0.83 V, n = 1) and the trivalent samarium cation was successfully converted to the divalent cation having characteristic absorption bands at 380 and 530 nm with molar absorptivity values of 1470 and 810 M-1 cm-1, respectively. Density function theory calculations for the divalent samarium complex revealed that the absorption signals originated from the 4f6 to 4f55d1 transitions. Additionally, laser-induced emission measurements for the Sm cations in the LiCl-KCl matrix showed that the Sm3+ ion in the LiCl-KCl melt at 450 °C emitted an orange color of fluorescence, whereas a red colored emission was observed from the Sm2+ ion in the solidified LCl-KCl salt at room temperature.

2.
J Foot Ankle Surg ; 56(2): 252-254, 2017.
Article in English | MEDLINE | ID: mdl-28231961

ABSTRACT

The Manchester-Oxford Foot Questionnaire (MOXFQ) is a practical, reliable, and valid questionnaire for hallux valgus surgery and has been translated into several languages. However, the MOXFQ has not been translated into Korean. In the present study, we aimed to translate and evaluate the validity and reliability of the Korean version of the MOXFQ for patients affected by hallux valgus. In accordance with the guidelines of cross-cultural adaptation, we translated the English version of MOXFQ into Korean and then backward translated it into English. We sent out letters that included the Korean version of the MOXFQ, a visual analog scale measure of pain, and a validated Korean version of the short-form 36-item Health Survey to 135 patients with hallux valgus. A retest was administered after 2 weeks. Of the 135 patients, 104 responded to the first questionnaire, and 82 of the first-time responders returned their second questionnaires. We evaluated the test-retest reliability, internal consistency, concurrent validity, and construct validity of the Korean version of the MOXFQ. The intraclass correlation coefficient for test-retest reliability was 0.82 for the total MOXFQ and ranged from 0.81 to 0.82 for the 3 subscales. Cronbach's alpha for the total MOXFQ was 0.85 and ranged from 0.8 to 0.92 for the 3 subscales. Concurrent and construct validity was supported by significant correlation with the visual analog scale and short-form 36-item Health Survey subscale scores. The Korean version of the MOXFQ was tested, and it was found to be a valid and reliable instrument for patients with hallux valgus.


Subject(s)
Disability Evaluation , Hallux Valgus/physiopathology , Adult , Aged , Aged, 80 and over , Female , Hallux Valgus/psychology , Humans , Male , Middle Aged , Reproducibility of Results , Republic of Korea , Surveys and Questionnaires , Translating
3.
Macromol Rapid Commun ; 37(1): 73-78, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26488433

ABSTRACT

Electrohydrodynamic cojetting has been employed to synthesize compartmentalized microfibers from thermally responsive hydrogels. The synthesis of the hydrogels as well as their transformation into compartmentalized microcylinders is discussed. After programmable shape-shifting, snail-like particles are obtained that undergo functional and structural reconfiguration in response to a change in temperature.

4.
J Foot Ankle Surg ; 55(4): 759-61, 2016.
Article in English | MEDLINE | ID: mdl-27067199

ABSTRACT

Although translated versions of the Foot Function Index (FFI) in several languages are available, the absence of a Korean version has precluded comparing the data from Korea with the data from other countries using the FFI. We, therefore, evaluated the reliability and validity of the adapted Korean version of the FFI. We translated the English version of the FFI into Korean and back into English. We mailed the Korean version of the visual analog scale, FFI, and the previously validated Medical Outcomes Study Short-Form 36-item questionnaire (SF-36) to 121 patients with treated foot complaints. To evaluate the test-retest reliability and internal consistency, we used the intraclass correlation coefficient and Cronbach's α, respectively. We also evaluated the concurrent and construct validity of Korean version of the FFI by comparing the visual analog scale and SF-36. Cronbach's α was 0.91 and 0.95 for the pain and disability subscales, respectively. The reproducibility was good, and a strong correlation between the FFI and the SF-36 and visual analog scale with related content was observed, indicating good construct validity.The Korean version of the FFI is a reliable and valid questionnaire for the self-assessment of pain and disability in Korean patients with foot complaints.


Subject(s)
Disability Evaluation , Foot/physiopathology , Adult , Aged , Female , Humans , Male , Middle Aged , Reproducibility of Results , Republic of Korea , Translating , Visual Analog Scale , Young Adult
5.
Nano Lett ; 14(10): 5493-9, 2014 Oct 08.
Article in English | MEDLINE | ID: mdl-25255444

ABSTRACT

Single molecule break junction experiments and nonequilibrium Green's function calculations using density functional theory (NEGF-DFT) of carbodithioate- and thiol-terminated [5,15-bis(phenylethynyl)-10,20-diarylporphinato]zinc(II) complexes reveal the impact of the electrode-linker coordination mode on charge transport at the single-molecule level. Replacement of thiolate (-S(-)) by the carbodithioate (-CS2(-)) anchoring motif leads to an order of magnitude increase of single molecule conductance. In contrast to thiolate-terminated structures, metal-molecule-metal junctions that exploit the carbodithioate linker manifest three distinct conductance values. We hypothesize that the magnitudes of these conductances depend upon carbodithoate linker hapticity with measured conductances across Au-[5,15-bis(4'-(dithiocarboxylate)phenylethynyl)-10,20-diarylporphinato]zinc(II)-Au junctions the greatest when both anchoring groups attach to the metal surface in a bidentate fashion. We support this hypothesis with NEGF-DFT calculations, which consider the electron transport properties for specific binding geometries. These results provide new insights into the origin of molecule-to-molecule conductance heterogeneity in molecular charge transport measurements and the factors that optimize electrode-molecule-electrode electronic coupling and maximize the conductance for charge transport.


Subject(s)
Coordination Complexes/chemistry , Electric Conductivity , Metalloporphyrins/chemistry , Thiocarbamates/chemistry , Zinc/chemistry , Electrodes , Electronics/instrumentation , Equipment Design , Models, Molecular
6.
Expert Opin Biol Ther ; 24(4): 305-312, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38664937

ABSTRACT

BACKGROUND: The trastuzumab biosimilar CT-P6 is approved for human epidermal growth factor receptor 2 (HER2)-positive early breast cancer (EBC), metastatic breast cancer (MBC), and metastatic gastric cancer (MGC). The objective of this post-marketing surveillance (PMS) study was to evaluate the real-world safety and effectiveness of CT-P6 in patients with HER2-positive cancers. RESEARCH DESIGN AND METHODS: This open-label, observational, prospective, PMS study collected data via investigator surveys from 35 centers in the Republic of Korea (5 October 2018-4 October 2022). Eligible patients with HER2-positive EBC, MBC, or MGC started CT-P6 treatment during routine clinical practice, followed by 1-year observation. Evaluations included adverse events (AEs), adverse drug reactions (ADRs), and effectiveness. RESULTS: Safety was analyzed in 642 patients (494 EBC, 94 MBC, 54 MGC). Overall, 325 (50.6%) patients experienced 1316 AEs, and 550 ADRs occurred in 199 (31.0%) patients. Unexpected ADRs occurred in 62 (9.7%) patients. Unexpected ADRs and ADRs of special interest did not raise any new safety signals. Among trastuzumab-naïve patients, 34/106 (32.1%) with EBC achieved pathological complete response; 30/74 (40.5%) MBC and 24/49 (49.0%) MGC patients achieved complete or partial response. CONCLUSIONS: In a real-world setting, CT-P6 demonstrated safety and efficacy findings consistent with previous CT-P6 studies.


Subject(s)
Antineoplastic Agents, Immunological , Biosimilar Pharmaceuticals , Breast Neoplasms , Product Surveillance, Postmarketing , Stomach Neoplasms , Trastuzumab , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Antineoplastic Agents, Immunological/adverse effects , Antineoplastic Agents, Immunological/therapeutic use , Biosimilar Pharmaceuticals/adverse effects , Biosimilar Pharmaceuticals/therapeutic use , Breast Neoplasms/drug therapy , Prospective Studies , Receptor, ErbB-2/genetics , Republic of Korea , Stomach Neoplasms/drug therapy , Trastuzumab/adverse effects , Trastuzumab/therapeutic use , Treatment Outcome
7.
Small ; 9(18): 3051-7, 2013 Sep 23.
Article in English | MEDLINE | ID: mdl-23606461

ABSTRACT

On-demand degradable polymer particles are fabricated via electrospraying of a solution of acetal-protected dextran that further includes 2-(4-methoxystyryl)-4,6-bis(trichloromethyl)-1,3,5-triazine as a photoacid generator. The illumination of UV light gives rise to photoacid and activates the catalytic deprotection of hydroxyl groups of dextran, leading to controlled dissolution of the microparticles in water.


Subject(s)
Drug Carriers/chemistry , Drug Delivery Systems/methods , Polymers/chemistry , Nanoparticles/chemistry
8.
Langmuir ; 29(20): 6181-6, 2013 May 21.
Article in English | MEDLINE | ID: mdl-23617390

ABSTRACT

Janus microcylinders composed of different polymers were prepared through coaxial co-jetting with dual-core flows, followed by cross-linking, microsectioning, and shell removal. Uniquely shaped building blocks can be fabricated by photo-patterning of one hemisphere of the microcylinders.


Subject(s)
Microfluidic Analytical Techniques , Polyglactin 910/chemistry , Hydrodynamics , Microfluidic Analytical Techniques/instrumentation
9.
Nano Lett ; 12(6): 2722-7, 2012 Jun 13.
Article in English | MEDLINE | ID: mdl-22500812

ABSTRACT

Understanding and controlling electron transport through functional molecules are of primary importance to the development of molecular scale devices. In this work, the single molecule resistances of meso-to-meso ethyne-bridged (porphinato)zinc(II) structures (PZn(n) compounds), connected to gold electrodes via (4'-thiophenyl)ethynyl termini, are determined using scanning tunneling microscopy-based break junction methods. These experiments show that each α,ω-di[(4'-thiophenyl)ethynyl]-terminated PZn(n) compound (dithiol-PZn(n)) manifests a dual molecular conductance. In both the high and low conductance regimes, the measured resistance across these metal-dithiol-PZn(n)-metal junctions increases in a near linear fashion with molecule length. These results signal that meso-to-meso ethyne-bridged porphyrin wires afford the lowest ß value (ß = 0.034 Å(-1)) yet determined for thiol-terminated single molecules that manifest a quasi-ohmic resistance dependence across metal-dithiol-PZn(n)-metal junctions.


Subject(s)
Nanostructures/chemistry , Nanostructures/ultrastructure , Porphyrins/chemistry , Electric Conductivity , Electron Transport , Materials Testing , Particle Size
10.
Nano Lett ; 12(5): 2414-9, 2012 May 09.
Article in English | MEDLINE | ID: mdl-22545580

ABSTRACT

Temperature-dependent transport of hybrid structures consisting of gold nanoparticle arrays functionalized by conjugated organic molecules [(4'-thiophenyl)ethynyl-terminated meso-to-meso ethyne-bridged (porphinato)zinc(II) complexes] that possess exceptional optical and electronic properties was characterized. Differential conductance analysis distinguished the functional forms of the temperature and voltage dependences for a range of sample particles and molecular attachments. Thermally assisted tunneling describes transport for all cases and the associated mechanistic parameters can be used to determine the relative roles of activation energy, work function, and so forth. These results provide the basis on which to examine plasmon-influenced conduction in hybrid systems.

11.
Water Res ; 222: 118864, 2022 Aug 15.
Article in English | MEDLINE | ID: mdl-35870393

ABSTRACT

Environmental damage from serious nuclear accidents should be urgently restored, which needs the removal of radioactive species. Radioactive iodine isotopes are particularly problematic for human health because they are released in large amounts and retain radioactivity for a substantial time. Herein, we prepare platinum-coated iron nanoparticles (Fe@Pt) as a highly selective and reusable adsorbent for iodine species, i.e., iodide (I-), iodine (I2), and methyl iodide (CH3I). Fe@Pt selectively separates iodine species from seawater and groundwater with a removal efficiency ≥ 99.8%. The maximum adsorption capacity for the iodine atom of all three iodine species was determined to be 25 mg/g. The magnetic properties of Fe@Pt allow for the facile recovery and reuse of Fe@Pt, which remains stable with high efficiency (97.5%) over 100 uses without structural and functional degradation in liquid media. Practical application to the removal of radioactive 129I and feasibility for scale-up using a 20 L system demonstrate that Fe@Pt can function as a reusable adsorbent for the selective removal of iodine species. This systematic procedure is a standard protocol for designing highly active adsorbents for the clean separation and removal of various chemical species dissolved in wastewater.


Subject(s)
Iodine , Thyroid Neoplasms , Water Pollutants, Chemical , Adsorption , Humans , Iodides , Iodine Radioisotopes/chemistry , Water/chemistry , Water Pollutants, Chemical/chemistry
12.
J Am Chem Soc ; 133(50): 20138-41, 2011 Dec 21.
Article in English | MEDLINE | ID: mdl-22122560

ABSTRACT

High reversibility during crystallization leads to relatively defect-free crystals through repair of nonperiodic inclusions, including those derived from impurities. Microporous coordination polymers (MCPs) can achieve a high level of crystallinity through a related mechanism whereby coordination defects are repaired, leading to single crystals. In this work, we discovered and exploited the fact that this process is far from perfect for MCPs and that a minority ligand that is coordinatively identical to but distinct in shape from the majority linker can be inserted into the framework, resulting in defects. The reaction of Zn(II) with 1,4-benzenedicarboxylic acid (H(2)BDC) in the presence of small amounts of 1,3,5-tris(4-carboxyphenyl)benzene (H(3)BTB) leads to a new crystalline material, MOF-5(O(h)), that is nearly identical to MOF-5 but has an octahedral morphology and a number of defect sites that are uniquely functionalized with dangling carboxylates. The reaction with Pd(OAc)(2) impregnates the metal ions, creating a heterogeneous catalyst with ultrahigh surface area. The Pd(II)-catalyzed phenylation of naphthalene within Pd-impregnated MOF-5(O(h)) demonstrates the potential utility of an MCP framework for modulating the reactivity and selectivity of such transformations. Furthermore, this novel synthetic approach can be applied to different MCPs and will provide scaffolds functionalized with catalytically active metal species.


Subject(s)
Organic Chemicals/chemistry , Palladium/chemistry , Crystallization , Powder Diffraction
13.
Macromol Rapid Commun ; 32(5): 431-7, 2011 Mar 02.
Article in English | MEDLINE | ID: mdl-21433195

ABSTRACT

We demonstrate spatially controlled photoreactions within bicompartmental microparticles and microfibers. Selective photoreactions are achieved by anisotropic incorporation of photocrosslinkable poly(vinyl cinnamate) in one compartment of either colloids or microfibers. Prior to photoreaction, bicompartmental particles, and fibers were prepared by EHD co-jetting of two compositionally distinct polymer solutions. Physical and chemical anisotropy was confirmed by confocal laser scanning microscopy, Fourier-transformed infrared spectroscopy, and scanning electron microscopy. The data indicate adjustment of polymer concentrations of the jetting solutions to be the determining factors for particle and fiber structures. Subsequent exposure of poly(vinyl cinnamate)-based particles and fibers to UV light at 254 nm resulted in spatially controlled crosslinking. Treatment of the crosslinked bicompartmental colloids with chloroform produced half-moon shaped objects. These hemishells exhibited a distinct porous morphology with pore sizes in the range of 70 nm. Based on this novel synthetic approach, Janus-type particles and fibers can be prepared by EHD co-jetting and can be selectively photocrosslinked without the need for masks or selective laser writing.


Subject(s)
Colloids/chemistry , Nanotechnology , Polymers/chemistry , Anisotropy , Microspheres , Particle Size , Solutions/chemistry
14.
Nano Lett ; 10(10): 4192-9, 2010 Oct 13.
Article in English | MEDLINE | ID: mdl-20809609

ABSTRACT

Use of phase transfer catalysts such as 18-crown-6 enables ionic, linear conjugated poly[2,6-{1,5-bis(3-propoxysulfonicacidsodiumsalt)}naphthylene]ethynylene (PNES) to efficiently disperse single-walled carbon nanotubes (SWNTs) in multiple organic solvents under standard ultrasonication methods. Steady-state electronic absorption spectroscopy, atomic force microscopy (AFM), and transmission electron microscopy (TEM) reveal that these SWNT suspensions are composed almost exclusively of individualized tubes. High-resolution TEM and AFM data show that the interaction of PNES with SWNTs in both protic and aprotic organic solvents provides a self-assembled superstructure in which a PNES monolayer helically wraps the nanotube surface with periodic and constant morphology (observed helical pitch length = 10 ± 2 nm); time-dependent examination of these suspensions indicates that these structures persist in solution over periods that span at least several months. Pump-probe transient absorption spectroscopy reveals that the excited state lifetimes and exciton binding energies of these well-defined nanotube-semiconducting polymer hybrid structures remain unchanged relative to analogous benchmark data acquired previously for standard sodium dodecylsulfate (SDS)-SWNT suspensions, regardless of solvent. These results demonstrate that the use of phase transfer catalysts with ionic semiconducting polymers that helically wrap SWNTs provide well-defined structures that solubulize SWNTs in a wide range of organic solvents while preserving critical nanotube semiconducting and conducting properties.

15.
J Am Chem Soc ; 132(23): 7946-56, 2010 Jun 16.
Article in English | MEDLINE | ID: mdl-20433175

ABSTRACT

In molecular electronics, the linker group, which attaches the functional molecular core to the electrode, plays a crucial role in determining the overall conductivity of the molecular junction. While much focus has been placed on optimizing molecular core conductivity, there have been relatively few attempts at designing optimal linker groups to metallic or semiconducting electrodes. The vast majority of molecular electronic studies use thiol linker groups; work probing alternative amine linker systems has only recently been explored. Here, we probe single-molecule conductances in phenylene-ethynylene molecules terminated with thiol and carbodithioate linkers, experimentally using STM break-junction methods and theoretically using a nonequilibrium Green's function approach. Experimental studies demonstrate that the carbodithioate linker augments electronic coupling to the metal electrode and lowers the effective barrier for charge transport relative to the conventional thiol linker, thus enhancing the conductance of the linker-phenylene-ethynylene-linker unit; these data underscore that phenylene-ethynylene-based structures are more highly conductive than originally appreciated in molecular electronics applications. The theoretical analysis shows that the nature of sulfur hybridization in these species is responsible for the order-of-magnitude increased conductance in carbodithioate-terminated systems relative to identical conjugated structures that feature classic thiol linkers, independent of the mechanism of charge transport. Interestingly, in these systems, the tunneling current is not dominated by the frontier molecular orbitals. While barriers >k(B)T to produce the low beta values seen in our experiments. Taken together, these experimental and theoretical studies indicate a promising role for carbodithioate-based connectivity in molecular-scale electronics applications involving metallic and semiconducting electrodes.


Subject(s)
Electric Conductivity , Polymers/chemistry , Thiocarbamates/chemistry , Models, Molecular , Molecular Conformation , Quantum Theory
16.
Nano Lett ; 9(4): 1414-8, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19281229

ABSTRACT

Amphiphilic, linear conjugated poly[p-{2,5-bis(3-propoxysulfonicacidsodiumsalt)}phenylene]ethynylene (PPES) efficiently disperses single-walled carbon nanotubes (SWNTs) under ultrasonication conditions into the aqueous phase. Vis-NIR absorption spectroscopy, atomic force microscopy (AFM), and transmission electron microscopy (TEM) demonstrate that these solubilized SWNTs are highly individualized. AFM and TEM data reveal that the interaction of PPES with SWNTs gives rise to a self-assembled superstructure in which a polymer monolayer helically wraps the nanotube surface; the observed PPES pitch length (13 +/- 2 nm) confirms structural predictions made via molecular dynamics simulations. This work underscores design elements important for engineering well-defined nanotube-semiconducting polymer hybrid structures.

17.
J Am Chem Soc ; 131(51): 18198-9, 2009 Dec 30.
Article in English | MEDLINE | ID: mdl-19954193

ABSTRACT

A diverse collection of 14 metal-organic frameworks (MOFs) was screened for CO(2) capture from flue gas using a combined experimental and modeling approach. Adsorption measurements are reported for the screened MOFs at room temperature up to 1 bar. These data are used to validate a generalized strategy for molecular modeling of CO(2) and other small molecules in MOFs. MOFs possessing a high density of open metal sites are found to adsorb significant amounts of CO(2) even at low pressure. An excellent correlation is found between the heat of adsorption and the amount of CO(2) adsorbed below 1 bar. Molecular modeling can aid in selection of adsorbents for CO(2) capture from flue gas by screening a large number of MOFs.

19.
Org Lett ; 9(15): 2779-82, 2007 Jul 19.
Article in English | MEDLINE | ID: mdl-17602486

ABSTRACT

Carbodithioate-terminated bis(phenylene)ethynylenes and oligo(phenyleneethynylene)s have been synthesized from TMSE-protected 4-iododithiobenzoic acid ester (1) and 4-ethynyldithiobenzoic acid ester (3) via Pd-catalyzed cross-coupling reactions. TEM and spectroscopic studies demonstrate that the reaction of 4-(phenylethynyl)dithiobenzoate with alkylamine-protected gold nanoparticles (AuNPs) produces the corresponding organocarbodithioate-functionalized AuNPs.

20.
J Speech Lang Hear Res ; 60(6S): 1810-1817, 2017 06 22.
Article in English | MEDLINE | ID: mdl-28655050

ABSTRACT

Purpose: Recent research suggests that visual-acoustic biofeedback can be an effective treatment for residual speech errors, but adoption remains limited due to barriers including high cost and lack of familiarity with the technology. This case study reports results from the first participant to complete a course of visual-acoustic biofeedback using a not-for-profit iOS app, Speech Therapist's App for /r/ Treatment. Method: App-based biofeedback treatment for rhotic misarticulation was provided in weekly 30-min sessions for 20 weeks. Within-treatment progress was documented using clinician perceptual ratings and acoustic measures. Generalization gains were assessed using acoustic measures of word probes elicited during baseline, treatment, and maintenance sessions. Results: Both clinician ratings and acoustic measures indicated that the participant significantly improved her rhotic production accuracy in trials elicited during treatment sessions. However, these gains did not transfer to generalization probes. Conclusions: This study provides a proof-of-concept demonstration that app-based biofeedback is a viable alternative to costlier dedicated systems. Generalization of gains to contexts without biofeedback remains a challenge that requires further study. App-delivered biofeedback could enable clinician-research partnerships that would strengthen the evidence base while providing enhanced treatment for children with residual rhotic errors. Supplemental Material: https://doi.org/10.23641/asha.5116318.


Subject(s)
Articulation Disorders/therapy , Biofeedback, Psychology , Mobile Applications , Speech Therapy , Therapy, Computer-Assisted , Adolescent , Biofeedback, Psychology/methods , Female , Generalization, Psychological , Humans , Phonetics , Proof of Concept Study , Speech Acoustics , Speech Therapy/methods , Treatment Outcome
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