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2.
Opt Lett ; 47(7): 1705-1708, 2022 Apr 01.
Article in English | MEDLINE | ID: mdl-35363713

ABSTRACT

Unlike the ideal circular whispering gallery cavities, those without mirror symmetry intrinsically support resonant modes exhibiting chirality which indicates an imbalance between clockwise and counterclockwise wave components. In extreme cases, nearly degenerate pairs of copropagating modes can be found around the chiral exceptional points (EPs) in parameter spaces. The chiral EPs have been studied in various schemes; however, most attention has been focused on the cases with piecewise constant or periodic refractive index profiles. In this Letter, we report the formation of a chiral EP in a gradient-index cavity designed by conformal transformation optics. Here, the mirror symmetry of the cavity is broken solely by its gradient index profile, and the parameter space is constructed with coordinate transformation parameters. We unveil the chirality, nonorthogonality, and complex-square-root topology near the chiral EP, which can be explained by the non-Hermitian model Hamiltonian.

3.
Opt Express ; 29(10): 14736-14744, 2021 May 10.
Article in English | MEDLINE | ID: mdl-33985189

ABSTRACT

Using the transformation cavity, a gradient index cavity designed by transformation optics, we propose a hybrid resonator system to extract unidirectional narrow-beam emission from high-Q whispering gallery modes by embedding a transformation cavity inside a deformed uniform index cavity that exhibits unidirectional narrow-beam emission. For effective mode coupling between the transformation cavity and enclosing cavity, the embedded transformation cavity is designed to have bidirectional evanescent emission, which enables most of the emission from the transformation cavity to be laterally incident on the rim of the enclosing deformed cavity. Consequently, ultrahigh-Q resonances of this system can provide a sharp free-space light output, which is difficult to achieve by embedding a homogeneous disk cavity instead of the transformation cavity.

4.
Opt Express ; 29(6): 9242-9251, 2021 Mar 15.
Article in English | MEDLINE | ID: mdl-33820356

ABSTRACT

It was reported that whispering gallery cavities designed by conformal transformation optics can support high-Q resonant modes with emission directionality. Intrinsically, these cavities have gradient index profiles implementing conformal mappings in physical space. In this paper, using the linear coordinate transformation, we propose another design scheme of whispering gallery cavities with (piecewise-) homogeneous, anisotropic index profile. We numerically show that so-designed cavities are also able to support high-Q whispering gallery modes with directional far-field emission patterns. We verify such characteristics by using a phase space representation (called the Poincaré Husimi function) of the intracavity wave function.

6.
Sci Rep ; 9(1): 19684, 2019 Dec 23.
Article in English | MEDLINE | ID: mdl-31873097

ABSTRACT

In the case of two-dimensional gradient index cavities designed by the conformal transformation optics, we propose a boundary integral equation method for the calculation of resonant mode functions by employing a fictitious space which is reciprocally equivalent to the physical space. Using the Green's function of the interior region of the uniform index cavity in the fictitious space, resonant mode functions and their far-field distributions in the physical space can be obtained. As a verification, resonant modes in limaçon-shaped transformation cavities were calculated and mode patterns and far-field intensity distributions were compared with those of the same modes obtained from the finite element method.

7.
Sci Rep ; 9(1): 8506, 2019 Jun 11.
Article in English | MEDLINE | ID: mdl-31186445

ABSTRACT

Directional light emission from high-Q resonant modes without significant Q-spoiling has been a long standing issue in deformed dielectric cavities. In limaçon-shaped gradient index dielectric cavities recently proposed by exploiting conformal transformation optics, the variation of Q-factors and emission directionality of resonant modes was traced in their system parameter space. For these cavities, their boundary shapes and refractive index profiles are determined in each case by a chosen conformal mapping which is taken as a coordinate transformation. Through the numerical exploration, we found that bidirectionality factors of generic high-Q resonant modes are not directly proportional to their Q-factors. The optimal system parameters for the coexistence of strong bidirectionality and a high Q-factor was obtained for anisotropic whispering gallery modes supported by total internal reflection.

8.
Opt Express ; 27(11): 16320-16328, 2019 May 27.
Article in English | MEDLINE | ID: mdl-31163811

ABSTRACT

A novel approach to designing anisotropic whispering gallery modes in gradient index cavities has been reported recently. These cavities, called transformation cavities, can support high-Q whispering gallery modes with directional emission. However, it is usually difficult to find the desired conformal mapping, and it may contain unwanted singularities inside. We show that arbitrary-shaped transformation cavities can be designed by virtue of a quasi-conformal mapping method without confronting such problems. Even though the quasi-conformal mapping method is exploited, we verify that the resulting mappings in our case are strictly conformal. As a demonstration, Q-factor, near field intensity, far field pattern, and phase space description of resonant modes formed in so-designed quadrupole-shaped transformation cavities are presented.

9.
Am J Sports Med ; 46(9): 2192-2202, 2018 07.
Article in English | MEDLINE | ID: mdl-29924633

ABSTRACT

BACKGROUND: Shoulder stiffness is a common complication after arthroscopic rotator cuff repair. However, there is no consensus on the treatment of stiffness after repair. Although one treatment option is an intra-articular steroid injection, it may negatively affect repair integrity, and there is a paucity of literature regarding the timing of intra-articular injections for stiffness after repair and its effect on repair integrity. PURPOSE: To compare repair integrity and clinical outcomes after an intra-articular steroid injection administered at 6 weeks and 12 weeks postoperatively for shoulder stiffness after arthroscopic rotator cuff repair. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Patients who developed stiffness after arthroscopic rotator cuff repair were given a series of 3 intra-articular steroid injections every 4 weeks from 6 (6-week group) and 12 weeks (12-week group) postoperatively. The control group had rotator cuff tears but neither stiffness nor injections. Shoulder range of motion (ROM), the Korean Shoulder Scoring System (KSS) score, and the University of California, Los Angeles (UCLA) shoulder score were assessed preoperatively with a minimum of 2-year follow-up. Repair integrity was assessed using magnetic resonance imaging at 6 months postoperatively. RESULTS: Seventy-four of 209 patients (35.4%) who underwent arthroscopic rotator cuff repair developed stiffness. There were no significant differences in retear rates among the 6-week (5.7%, 2/35 patients), 12-week (10.3%, 4/39 patients), and control groups (14.1%, 19/135 patients) ( P = .374). Both the 6- and 12-week groups showed significant improvement in ROM (both P < .001), KSS scores (both P < .001), and UCLA scores (both P < .001) at the final follow-up. The 6-week group showed significantly better ROM ( P < .001), KSS scores ( P < .001), and UCLA scores ( P < .001) than the 12-week group at 3 months postoperatively. However, both the 6- and 12-week groups showed significantly lower KSS (81.3 ± 12.0 [ P = .004] and 83.4 ± 8.6 [ P = .035], respectively) and UCLA (29.3 ± 4.6 [ P = .006] and 30.0 ± 3.3 [ P = .042], respectively) scores than the control group (90.4 ± 13.6 and 32.3 ± 4.7, respectively) at the last follow-up. CONCLUSION: An intra-articular steroid injection administered at 6 weeks postoperatively for shoulder stiffness after arthroscopic rotator cuff repair may be effective for reducing patients' pain and improving shoulder ROM at 3 months postoperatively without compromising repair integrity.


Subject(s)
Adrenal Cortex Hormones/adverse effects , Injections, Intra-Articular/adverse effects , Range of Motion, Articular , Rotator Cuff Injuries/surgery , Shoulder/physiology , Aged , Arthroscopy , Cohort Studies , Female , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Postoperative Period , Shoulder/physiopathology
10.
Am J Sports Med ; 46(8): 1909-1918, 2018 07.
Article in English | MEDLINE | ID: mdl-29757693

ABSTRACT

BACKGROUND: Few studies have reported on the radiological characteristics and repair integrity of coexistent rotator cuff tears (RCTs) and shoulder stiffness after simultaneous arthroscopic rotator cuff repair and capsular release. PURPOSE: To evaluate the radiological characteristics and repair integrity of 1-stage arthroscopic surgery of RCTs concomitant with shoulder stiffness. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Among patients who underwent arthroscopic repair of full-thickness RCTs, the stiff group underwent simultaneous capsular release for shoulder stiffness, and the nonstiff group had no stiffness. Symptom duration, prevalence of diabetes, tear size, tendon involvement (type 1, supraspinatus; type 2, supraspinatus and subscapularis; and type 3, supraspinatus and infraspinatus; type 4, supraspinatus, subscapularis, and infraspinatus), and fatty infiltration (Goutallier stages 0-4) were evaluated. A retear was appraised using magnetic resonance imaging, and clinical outcomes were assessed using range of motion, the Korean Shoulder Scoring System (KSS), and the University of California, Los Angeles (UCLA) shoulder score. RESULTS: The stiff group showed a significantly lower retear rate (1/39, 2.6%) than the nonstiff group (47/320, 14.7%) ( P = .043). There were significant differences in symptom duration (7.4 ± 6.6 vs 15.0 ± 23.7 months, respectively; P < .001), mediolateral tear size (18.9 ± 8.9 vs 24.1 ± 12.0 mm, respectively; P = .002), tendon involvement (94.9%, 5.1%, 0.0%, and 0.0% vs 85.3%, 6.9%, 7.8%, and 0.0%, respectively; P = .048), and fatty infiltration of the subscapularis (66.7%, 33.3%, 0.0%, 0.0%, and 0.0% vs 31.9%, 61.3%, 5.6%, 1.3%, and 0.0%, respectively; P < .001) and teres minor (74.4%, 20.5%, 5.1%, 0.0%, and 0.0% vs 47.2%, 48.8%, 3.8%, 0.0%, and 0.3%, respectively; P = .007) between the stiff and nonstiff groups. Preoperatively, the stiff group showed significantly worse forward flexion (95.9° ± 23.6° vs 147.7° ± 4.2°, respectively; P < .001), external rotation (17.4° ± 10.1° vs 51.6° ± 12.1°, respectively; P < .001), and internal rotation (L5 vs L2, respectively; P < .001) and lower KSS (52.1 ± 13.8 vs 66.3 ± 13.5, respectively; P < .001) and UCLA scores (18.7 ± 4.8 vs 22.5 ± 4.5, respectively; P < .001) than the nonstiff group. However, these differences became insignificant from 3 months postoperatively for forward flexion ( P > .05) and KSS ( P > .05) and UCLA scores ( P > .05), from 1 year postoperatively for external rotation ( P > .05), and at the last follow-up for internal rotation ( P > .05). A multiple logistic regression analysis revealed that only mediolateral tear size (odds ratio, 1.043; P = .014) and type 2 tendon involvement (odds ratio, 4.493; P = .003) were independent predictors of a retear. CONCLUSION: RCTs concomitant with shoulder stiffness showed a smaller mediolateral tear size, anterosuperior tendon involvement, and less severe fatty infiltration preoperatively and better repair integrity postoperatively than RCTs without stiffness. Furthermore, the clinical outcomes and range of motion at final follow-up were similar between the 2 groups.


Subject(s)
Joint Capsule Release , Range of Motion, Articular , Rotator Cuff Injuries/surgery , Shoulder Joint/surgery , Aged , Arthroplasty , Arthroscopy/methods , Cohort Studies , Female , Humans , Joint Diseases , Lacerations/surgery , Magnetic Resonance Imaging , Male , Middle Aged , Radiography , Recurrence , Rotation , Rotator Cuff/surgery , Rotator Cuff Injuries/diagnostic imaging , Rupture/surgery , Shoulder/surgery , Shoulder Joint/diagnostic imaging , Tendons/surgery , Treatment Outcome
11.
Arthroscopy ; 34(7): 2076-2084, 2018 07.
Article in English | MEDLINE | ID: mdl-29789254

ABSTRACT

PURPOSE: To determine the influence of preoperative factors on reparability of rotator cuff tears (RCTs) and yield a predictive model for predicting irreparability preoperatively. METHODS: Among patients with full-thickness RCTs, the reparable group underwent arthroscopic rotator cuff repairs for reparable RCTs whereas the irreparable group underwent alternative surgical procedures for irreparable RCTs. We analyzed age, sex, chronic pseudoparalysis (CPP), mediolateral and anteroposterior tear sizes, acromiohumeral distance (AHD), tangent sign, fatty infiltration (FI) (group 1, Goutallier stage 0 or 1; and group 2, Goutallier stage 2, 3, or 4), and tendon involvement (TI) (type 1, supraspinatus; type 2, supraspinatus and subscapularis; type 3, supraspinatus and infraspinatus; and type 4, all 3 tendons). RESULTS: The irreparability rate was 12.5%. Between the reparable (663 patients) and irreparable (95 patients) groups, significant differences were found in age (58.8 ± 8.3 years vs 65.6 ± 8.0 years, P < .001); female sex (46.9% vs 63.2%, P = .014); CPP (6.5% vs 36.8%, P < .001); mediolateral tear size (23.7 ± 12.1 mm vs 47.4 ± 9.1 mm, P < .001); anteroposterior tear size (17.9 ± 11.5 mm vs 43.4 ± 16.2 mm, P < .001); AHD (9.0 ± 1.7 mm vs 5.8 ± 1.6 mm, P < .001); tangent sign (2.9% vs 61.1%, P < .001); group 2 FI of the subscapularis (6.9% vs 20.0%, P < .001), supraspinatus (12.1% vs 58.9%, P < .001), infraspinatus (26.8% vs 69.5%, P < .001), and teres minor (4.2% vs 10.5%, P = .008); and type 1, 2, 3, and 4 TI (88.1%, 6.2%, 5.4%, and 0.3%, respectively, vs 29.5%, 21.1%, 28.4%, and 21.1%, respectively; P < .001). Multiple logistic regression analysis showed CPP, mediolateral tear size, AHD, tangent sign, group 2 FI of the supraspinatus, and type 4 TI were significant independent predictors of irreparability, with odds ratios of 3.539 (P = .007), 1.087 (P < .001), 0.624 (P < .001), 6.141 (P < .001), 2.233 (P = .034), and 12.350 (P = .016), respectively. These factors yielded a predictive model for irreparability as follows: Logit P = 1.264 × CPP + 0.084 × Mediolateral tear size - 0.472 × AHD + 0.804 × Group 2 FI of supraspinatus + 1.815 × Tangent sign + 2.514 × Type 4 TI - 3.460. CONCLUSIONS: The irreparability of RCTs is strongly associated with CPP, mediolateral tear size, AHD, tangent sign, group 2 FI of the supraspinatus, and type 4 TI and can be preoperatively calculated using the predictive equation. LEVEL OF EVIDENCE: Level III, retrospective comparative study.


Subject(s)
Rotator Cuff Injuries/surgery , Rotator Cuff/surgery , Adult , Age Factors , Aged , Algorithms , Arthroscopy/methods , Female , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Muscle Weakness/complications , Muscle Weakness/diagnostic imaging , Predictive Value of Tests , Prognosis , Retrospective Studies , Risk Factors , Rotator Cuff/diagnostic imaging , Rotator Cuff Injuries/complications , Rotator Cuff Injuries/diagnostic imaging , Rotator Cuff Injuries/pathology , Rupture/diagnostic imaging , Rupture/pathology , Rupture/surgery , Sex Factors
12.
Asian Pac J Allergy Immunol ; 36(3): 175-183, 2018 Sep.
Article in English | MEDLINE | ID: mdl-29602283

ABSTRACT

BACKGROUND: Natural killer (NK) cells are crucial components of the innate immune system, providing the first line of defense against pathogens. In a previous study, we demonstrated prophylactic activity of water extract of Korean mistletoe (Viscum album coloratum) on tumor metastasis. However, the leading compound from water extract of Korean mistletoe was not clearly addressed. OBJECTIVE: The purpose of this research was mainly focused on addressing the effect of Korean mistletoe lectin (KMLC) on NK cell cytotoxicity, and the ability of cytokine secretion as well as its signal transduction, mitogen-activated protein kinase (MAPK) pathway. METHODS: KMLC was used to test NK cell-mediated cytotoxicity in vitro and in vivo. Non-isotope cytotoxicity assay (bis-N,N,N',N'-tetraacetic acid (BATDA) release assay) was performed to test the cytotoxicity of NK cells against target tumor cells. Receptor expression was checked by flow cytometry analysis and MAPK signal molecules were analyzed by immunoblotting. RESULTS AND CONCLUSIONS: KMLC at 200 ng/mL increased the cytotoxicity of NK92 cells by 35% compared with untreated cells. KMLC-treated (at 100 ng/mL) mice splenocytes showed a 20% increase in cytotoxic activity. Also, the B chain, one of the subchains of KMLC, increases perforin expression. We demonstrated that the signal transduction controlling NK cell cytotoxicity was mediated by upregulation of the NKG2D receptor and expression of a cytotoxic effector molecule. These results suggested that KMLC possessed immunological activity, mediated by NK cell activation.


Subject(s)
Cytotoxicity, Immunologic/drug effects , Killer Cells, Natural/drug effects , Lymphocyte Activation/drug effects , Perforin/biosynthesis , Plant Extracts/pharmacology , Animals , Cell Line, Tumor , Humans , Killer Cells, Natural/immunology , Killer Cells, Natural/metabolism , Male , Mice , Mice, Inbred BALB C , Plant Lectins/pharmacology , Up-Regulation , Viscum album
13.
Opt Express ; 26(6): 6851-6859, 2018 Mar 19.
Article in English | MEDLINE | ID: mdl-29609372

ABSTRACT

Dielectric cavity systems, which have been studied extensively so far, have uniform refractive indices of their cavities, and Husimi functions, the most widely used phase space representation of optical modes formed in the cavities, accordingly were derived only for these homogeneous index cavities. For the case of the recently proposed gradient index dielectric cavities (called as transformation cavities) designed by optical conformal mapping, we show that the phase space structure of resonant modes can be revealed through the conventional Husimi functions by constructing a reciprocal virtual space. As examples, the Husimi plots were obtained for an anisotropic whispering gallery mode (WGM) and a short-lived mode supported in a limaçon-shaped transformation cavity. The phase space description of the corresponding modes in the reciprocal virtual space is compatible with the far-field directionality of the resonant modes in the physical space.

14.
Clin Shoulder Elb ; 21(1): 30-36, 2018 Mar.
Article in English | MEDLINE | ID: mdl-33330148

ABSTRACT

BACKGROUND: The Korean Shoulder Scoring System (KSS) is a reliable and valid procedure for discriminative assessment of the clinical status of patients with rotator cuff tears. This study evaluates the correlation between the preoperative KSS and factors in patients with rotator cuff tears. METHODS: From November 2009 to June 2016, 970 patients who underwent arthroscopic rotator cuff repair were retrospectively evaluated. A total of 490 patients met the study criteria. Preoperative factors included age, sex, symptom duration, mediolateral (ML) and anteroposterior (AP) tear size, acromiohumeral distance (AHD), tangent sign, tendon involvement (type I, supraspinatus; type II, supraspinatus and subscapularis; type III, supraspinatus and infraspinatus; type IV, all 3 tendons), fatty infiltration of rotator cuff muscles (group I, Goutallier stages 0 and 1; group II, Goutallier stages 2, 3, and 4), and KSS. RESULTS: Old age, ML tear size, and AP tear size negatively correlated with the preoperative KSS (p<0.001). AHD showed a positive correlation with the preoperative KSS (p<0.001). A significantly inferior preoperative KSS was found in females and type III tendon involvement (p<0.001). For supraspinatus and infraspinatus, the preoperative KSS of group II fatty infiltration showed a significantly lower score than group I fatty infiltration (p<0.05). CONCLUSIONS: A relatively lower preoperative KSS was associated with old age, large tear size, narrow AHD, female, type III tendon involvement, and group II fatty infiltration of the supraspinatus and infraspinatus. Our study indicates that preoperative KSS can be a good measurement for the preoperative status of patients with rotator cuff tears.

15.
BMC Complement Altern Med ; 17(1): 68, 2017 Jan 21.
Article in English | MEDLINE | ID: mdl-28109285

ABSTRACT

BACKGROUND: Korean mistletoe (Viscum album coloratum) is a semi-parasitic plant that grows on various trees and has a diverse range of effects on biological functions, being implicated in having anti-tumor, immunostimulatory, anti-diabetic, and anti-obesity properties. Recently, we also reported that Korean mistletoe extract (KME) improves endurance exercise in mice, suggesting its beneficial roles in enhancing the capacity of skeletal muscle. METHODS: We examined the expression pattern of several genes concerned with muscle physiology in C2C12 myotubes cells to identify whether KME inhibits muscle atrophy or promotes muscle hypertrophy. We also investigated these effects of KME in denervated mice model. RESULTS: Interestingly, KME induced the mRNA expression of SREBP-1c, PGC-1α, and GLUT4, known positive regulators of muscle hypertrophy, in C2C12 cells. On the contrary, KME reduced the expression of Atrogin-1, which is directly involved in the induction of muscle atrophy. In animal models, KME mitigated the decrease of muscle weight in denervated mice. The expression of Atrogin-1 was also diminished in those mice. Moreover, KME enhanced the grip strength and muscle weight in long-term feeding mice. CONCLUSIONS: Our results suggest that KME has beneficial effects on muscle atrophy and muscle hypertrophy.


Subject(s)
Gene Expression Regulation/drug effects , Muscle, Skeletal/drug effects , Plant Extracts/pharmacology , Viscum album/chemistry , Animals , Cell Line , Hypertrophy/drug therapy , Hypertrophy/genetics , Male , Mice , Mice, Inbred ICR , Muscle Contraction/drug effects , Muscle Denervation , Muscle Proteins/genetics , Muscle, Skeletal/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Republic of Korea , SKP Cullin F-Box Protein Ligases/genetics , Signal Transduction/drug effects , TOR Serine-Threonine Kinases/metabolism , Transcriptome
16.
Arthroscopy ; 32(11): 2191-2200, 2016 11.
Article in English | MEDLINE | ID: mdl-27209624

ABSTRACT

PURPOSE: To identify factors that predict retears after arthroscopic repair of full-thickness rotator cuff tears. METHODS: Factors included age, sex, diabetes, smoking, symptom duration (group I, <12 months; group II, ≥12 months), tear size according to the Kim classification (group I, A and B; group II, C; group III, D), tendon involvement (group I, supraspinatus; group II, supraspinatus and subscapularis; group III, supraspinatus and infraspinatus; group IV, all 3 tendons), and degree of fatty degeneration of the supraspinatus and infraspinatus (group I, Goutallier stages 1 and 2 for each tendon; group II, Goutallier stages 3 and 4 for each tendon). RESULTS: Two hundred eighty-two patients underwent arthroscopic repairs of full-thickness rotator cuff tears. The overall retear rate was 13.1%. Age, sex, diabetes, smoking, and degree of fatty degeneration of the supraspinatus and infraspinatus did not affect retear rates. However, symptom duration (P = .006), Kim classification (P < .001), and tendon involvement (P < .001) did affect retear rates. The retear rates were 8.5% (14 of 165 patients) and 19.7% (23 of 117) in symptom duration groups I and II, respectively; 8.0% (13 of 163), 15.2% (16 of 105), and 57.1% (8 of 14) in Kim classification groups I, II, and III, respectively; and 6.6% (11 of 167), 22.2% (18 of 81), 10.0% (2 of 20), and 42.9% (6 of 14) in tendon involvement groups I, II, III, and IV, respectively. In the multiple logistic regression analysis, the respective odds ratios of symptom duration group II, Kim classification group III, tendon involvement group II, and tendon involvement group IV were 2.853 (P = .011), 18.108 (P = .001), 4.184 (P = .001), and 5.727 (P = .021), respectively. CONCLUSIONS: To preoperatively predict retears after arthroscopic repair of full-thickness rotator cuff tears, the duration of symptoms before surgery, tear size, and tendon involvement can be used. In addition, regarding tear size, the Kim classification can be used more effectively than the modified DeOrio and Cofield classification. LEVEL OF EVIDENCE: Level IV, prognostic case series.


Subject(s)
Arthroscopy , Rotator Cuff Injuries/surgery , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Recurrence , Risk Factors , Rotator Cuff Injuries/classification , Suture Techniques
17.
Opt Express ; 23(13): 17443-9, 2015 Jun 29.
Article in English | MEDLINE | ID: mdl-26191753

ABSTRACT

Exploiting moiré interference, we make a new type of reconfigurable metamaterials and study their transmission tunability for incident electromagnetic waves. The moiré pattern is formed by overlapping two transparent layers, each of which has a periodic metallic pattern, and the cluster size of the resulting moiré pattern can be varied by changing the relative superposition angle of the two layers. In our reconfigurable metamaterials, both the size and structural shape of the unit cell can be varied simultaneously through moiré interference. We show that the transmission of electromagnetic waves can be controlled from 90% to 10% at 11 GHz by experiments and numerical simulation. The reconfigurable metamaterial proposed here can be applied in bandpass filters and tunable modulation devices.

18.
J Child Adolesc Psychopharmacol ; 24(9): 501-8, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25369174

ABSTRACT

UNLABELLED: Abstract Objective: There is evidence that Korean red ginseng (KRG) can reduce the production of the adrenal corticosteroids, cortisol, and dehydroepiandrosterone (DHEA), and thus may be a viable treatment for attention-deficit/hyperactivity disorder (ADHD). The present randomized double-blind placebo-controlled clinical trial tested the effect of KRG on children with ADHD symptoms. METHODS: Subjects 6-15 years, who satisfied the inclusion criteria and had ADHD symptoms, were randomized into a KRG group (n=33) or a control group (n=37). The KRG group received one pouch of KRG (1g KRG extract/pouch) twice a day, and the control group received one pouch of placebo twice a day. At the 8 week point, the primary outcomes were the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria for inattention and hyperactivity scale scores, which were measured at baseline and 8 weeks after starting treatment. Secondary outcomes were quantitative electroencephalography theta/beta ratio (QEEG TBR) (measured at baseline and week 8) and salivary cortisol and DHEA levels (measured at baseline and at 4 and 8 weeks). RESULTS: The baseline characteristics of the KRG and control groups were not statistically different. The mean ages of the KRG and control groups were 10.94±2.26 and 10.86±2.41, respectively. The KRG group had significantly decreased inattention/hyperactivity scores compared with the control group at week 8 (least squared means of the differences in inattention adjusted for baseline scores: -2.25 vs. -1.24, p=0.048; hyperactivity: -1.53 vs. -0.61, p=0.047). The KRG group had significantly decreased QEEG TBR compared with the control group (least squared means of the differences: -0.94 vs. -0.14, p=0.001). However, neither the KRG group nor the control group exhibited significant differences in salivary cortisol or DHEA levels at week 8 compared with the baseline levels. No serious adverse events were reported in either group. CONCLUSIONS: These results suggest that KRG extract may be an effective and safe alternative treatment for children with inattention and hyperactivity/impulsivity symptoms. Further studies to investigate the efficacy and safety of KRG are warranted.


Subject(s)
Attention Deficit Disorder with Hyperactivity/drug therapy , Panax , Plant Extracts/therapeutic use , Adolescent , Child , Dehydroepiandrosterone/analysis , Double-Blind Method , Electroencephalography/drug effects , Female , Humans , Hydrocortisone/analysis , Korea , Male , Plant Extracts/adverse effects , Saliva/chemistry
19.
Opt Lett ; 39(14): 4196-9, 2014 Jul 15.
Article in English | MEDLINE | ID: mdl-25121685

ABSTRACT

It is well known that the strongly deformed microcavity with fully chaotic ray dynamics cannot support high-Q modes due to its fast chaotic diffusion to the critical line of refractive emission. Here, we investigate how the Q factor is modified when two chaotic cavities are coupled, and show that some modes, whose Q factor is about 10 times higher than that of the corresponding single cavity, can exist. These abnormal high-Q modes are the result of an optimal combination of coupling and cavity geometry. As an example, in the coupled stadium-shaped microcavities, the mode pattern extends over both cavities such that it follows a whispering-gallery-type mode at both ends, whereas a big coupling spot forms at the closest contact of the two microcavities. The pattern of such a "rounded bow tie" mode allows the mode to have a high-Q factor. This mode pattern minimizes the leakage of light at both ends of the microcavities as the pattern at both ends is similar to the whispering gallery mode.

20.
Int Immunopharmacol ; 21(2): 309-19, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24859056

ABSTRACT

Korean mistletoe lectin (KML) is composed of A and B sub-chains. The B-chain binds to cell surfaces, whereas the A-chain hinders translation because it is a RIP (ribosome inactivating protein) inducing apoptosis. Although KML has various biological and immunological activities, its potential use in cancer therapy or as an adjuvant therapy is limited by its toxicity to normal cells. This study was conducted to determine whether the B-chain of KML (KML-B) has immunoadjuvant activity and cytotoxicity activity. To evaluate the immunomodulatory activities of B chain KML, in vitro experiments employing bone marrow-derived dendritic cells (BMDCs) were performed. Dendritic cells (DCs) are a unique group of white blood cells that are able to capture and process antigens for presentation to T cells, which constitute primary immune response. In the present study, KML-B was found to be non-cytotoxic to BMDCs. Furthermore, the expressions of co-stimulatory molecules (CD40, CD80, CD86, and MHC II) and the secretions of cytokines (IL-1ß, IL-6, IL-12p70, and TNF-α) were increased in BMDCs by KML-B. In addition, other indicators (antigen-uptake and CCR7 expression) of BMDC maturation were changed by KML-B, and the ability of KML-B to enhance various functions by BMDCs was found to be dependent on TLR4 expression. Moreover, BMDCs matured by KML-B induced naïve CD4(+) T cell differentiation toward Th1 cells directly and indirectly. These experiments confirm that KML-B exhibits potent immunomodulatory properties and suggest that KML-B be considered a potential dendritic cell-based cancer therapy and immunoadjuvant.


Subject(s)
Dendritic Cells/drug effects , Lectins/pharmacology , Lymphocyte Activation/drug effects , Mistletoe/chemistry , Toll-Like Receptor 4/analysis , Adjuvants, Immunologic/pharmacology , Animals , Antigens, CD/metabolism , Bone Marrow Cells/drug effects , Bone Marrow Cells/metabolism , Cell Differentiation/drug effects , Dendritic Cells/metabolism , Female , Humans , Interleukins/metabolism , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Th1 Cells/drug effects , Th1 Cells/metabolism , Tumor Necrosis Factor-alpha/metabolism
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