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Seo MH, Lee KK, Kim KS, Lee S. Highly Efficient Phosphorescent Light-Emitting Diodes by Using New Host Material. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2016; 16:2876-2879. [PMID: 27455724 DOI: 10.1166/jnn.2016.11050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
An electron-transporting triazole (Tz) and hole transporting carbazole (Cz) moieties were introduced into the fluorene structure via a Suzuki coupling reaction. The resulting material, 9-(4'-(9-(4'-(4,5-diphenyl-4H-1,2,4-triazol-3-y)-[1,1'-biphenyl]-4-yl)-9H-fluoren-9-yl)-[1,1'-biphenyl]-4-yl)-9H-carbazole (Tz-FL-Cz), was synthesized and can be used as the host layer in phosphorescent OLEDs. The synthesized material exhibits wide energy gap (3.46 eV). The absorption and emission maximum of the Tz-FL-Cz was observed at 300 nm and 389 nm, respectively. Blue phosphorescent devices using Tz-FL-Cz as host material exhibited maximum current efficiency of 3.2 cd/A and power efficiency of 1.3 lm/W, respectively.
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Shin J, Kim Y, Lee H, Lee J, Kim KS, Cho YJ, Jo YH, Rhu H, Kim KS, Lee SM, Min J, Park G, Yoon J, Park SI, Lee YJ. Transcultural adaptation and validation of familial satisfaction in the intensive care unit in Korea: preliminary study. Intensive Care Med Exp 2015. [PMCID: PMC4796308 DOI: 10.1186/2197-425x-3-s1-a654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
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Choi YJ, Kim KS, Suh GJ, Kwon WY, Yoo KM, Kim JS. Diagnostic performance of ct angiography for gastrointestinal haemorrhage according to the clinical severity. Intensive Care Med Exp 2015. [PMCID: PMC4797821 DOI: 10.1186/2197-425x-3-s1-a605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
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Yoo KM, Kim KS, Suh GJ, Kwon WY, Kim JS, Park MJ, Choi YJ, Kim K. Six-hour central venous oxygen saturation has no prognostic value in patients with septic shock. Intensive Care Med Exp 2015. [PMCID: PMC4797090 DOI: 10.1186/2197-425x-3-s1-a220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Aguilar M, Aisa D, Alpat B, Alvino A, Ambrosi G, Andeen K, Arruda L, Attig N, Azzarello P, Bachlechner A, Barao F, Barrau A, Barrin L, Bartoloni A, Basara L, Battarbee M, Battiston R, Bazo J, Becker U, Behlmann M, Beischer B, Berdugo J, Bertucci B, Bindi V, Bizzaglia S, Bizzarri M, Boella G, de Boer W, Bollweg K, Bonnivard V, Borgia B, Borsini S, Boschini MJ, Bourquin M, Burger J, Cadoux F, Cai XD, Capell M, Caroff S, Casaus J, Castellini G, Cernuda I, Cerreta D, Cervelli F, Chae MJ, Chang YH, Chen AI, Chen GM, Chen H, Chen HS, Cheng L, Chou HY, Choumilov E, Choutko V, Chung CH, Clark C, Clavero R, Coignet G, Consolandi C, Contin A, Corti C, Gil EC, Coste B, Creus W, Crispoltoni M, Cui Z, Dai YM, Delgado C, Della Torre S, Demirköz MB, Derome L, Di Falco S, Di Masso L, Dimiccoli F, Díaz C, von Doetinchem P, Donnini F, Duranti M, D'Urso D, Egorov A, Eline A, Eppling FJ, Eronen T, Fan YY, Farnesini L, Feng J, Fiandrini E, Fiasson A, Finch E, Fisher P, Formato V, Galaktionov Y, Gallucci G, García B, García-López R, Gargiulo C, Gast H, Gebauer I, Gervasi M, Ghelfi A, Giovacchini F, Goglov P, Gong J, Goy C, Grabski V, Grandi D, Graziani M, Guandalini C, Guerri I, Guo KH, Haas D, Habiby M, Haino S, Han KC, He ZH, Heil M, Hoffman J, Hsieh TH, Huang ZC, Huh C, Incagli M, Ionica M, Jang WY, Jinchi H, Kanishev K, Kim GN, Kim KS, Kirn T, Korkmaz MA, Kossakowski R, Kounina O, Kounine A, Koutsenko V, Krafczyk MS, La Vacca G, Laudi E, Laurenti G, Lazzizzera I, Lebedev A, Lee HT, Lee SC, Leluc C, Li HL, Li JQ, Li JQ, Li Q, Li Q, Li TX, Li W, Li Y, Li ZH, Li ZY, Lim S, Lin CH, Lipari P, Lippert T, Liu D, Liu H, Liu H, Lolli M, Lomtadze T, Lu MJ, Lu SQ, Lu YS, Luebelsmeyer K, Luo F, Luo JZ, Lv SS, Majka R, Mañá C, Marín J, Martin T, Martínez G, Masi N, Maurin D, Menchaca-Rocha A, Meng Q, Mo DC, Morescalchi L, Mott P, Müller M, Nelson T, Ni JQ, Nikonov N, Nozzoli F, Nunes P, Obermeier A, Oliva A, Orcinha M, Palmonari F, Palomares C, Paniccia M, Papi A, Pauluzzi M, Pedreschi E, Pensotti S, Pereira R, Picot-Clemente N, Pilo F, Piluso A, Pizzolotto C, Plyaskin V, Pohl M, Poireau V, Putze A, Quadrani L, Qi XM, Qin X, Qu ZY, Räihä T, Rancoita PG, Rapin D, Ricol JS, Rodríguez I, Rosier-Lees S, Rozhkov A, Rozza D, Sagdeev R, Sandweiss J, Saouter P, Schael S, Schmidt SM, von Dratzig AS, Schwering G, Scolieri G, Seo ES, Shan BS, Shan YH, Shi JY, Shi XY, Shi YM, Siedenburg T, Son D, Song JW, Spada F, Spinella F, Sun W, Sun WH, Tacconi M, Tang CP, Tang XW, Tang ZC, Tao L, Tescaro D, Ting SCC, Ting SM, Tomassetti N, Torsti J, Türkoğlu C, Urban T, Vagelli V, Valente E, Vannini C, Valtonen E, Vaurynovich S, Vecchi M, Velasco M, Vialle JP, Vitale V, Vitillo S, Wang LQ, Wang NH, Wang QL, Wang RS, Wang X, Wang ZX, Weng ZL, Whitman K, Wienkenhöver J, Willenbrock M, Wu H, Wu X, Xia X, Xie M, Xie S, Xiong RQ, Xu NS, Xu W, Yan Q, Yang J, Yang M, Yang Y, Ye QH, Yi H, Yu YJ, Yu ZQ, Zeissler S, Zhang C, Zhang JH, Zhang MT, Zhang SD, Zhang SW, Zhang XB, Zhang Z, Zheng ZM, Zhuang HL, Zhukov V, Zichichi A, Zimmermann N, Zuccon P. Precision Measurement of the Helium Flux in Primary Cosmic Rays of Rigidities 1.9 GV to 3 TV with the Alpha Magnetic Spectrometer on the International Space Station. PHYSICAL REVIEW LETTERS 2015; 115:211101. [PMID: 26636836 DOI: 10.1103/physrevlett.115.211101] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Indexed: 06/05/2023]
Abstract
Knowledge of the precise rigidity dependence of the helium flux is important in understanding the origin, acceleration, and propagation of cosmic rays. A precise measurement of the helium flux in primary cosmic rays with rigidity (momentum/charge) from 1.9 GV to 3 TV based on 50 million events is presented and compared to the proton flux. The detailed variation with rigidity of the helium flux spectral index is presented for the first time. The spectral index progressively hardens at rigidities larger than 100 GV. The rigidity dependence of the helium flux spectral index is similar to that of the proton spectral index though the magnitudes are different. Remarkably, the spectral index of the proton to helium flux ratio increases with rigidity up to 45 GV and then becomes constant; the flux ratio above 45 GV is well described by a single power law.
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Kim SH, Chong JU, Lim JH, Choi GH, Kang CM, Choi JS, Lee WJ, Kim KS. Optimal assessment of lymph node status in gallbladder cancer. Eur J Surg Oncol 2015; 42:205-10. [PMID: 26614023 DOI: 10.1016/j.ejso.2015.10.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Revised: 10/09/2015] [Accepted: 10/29/2015] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Lymph node (LN) metastasis is an important prognostic factor in gallbladder cancer (GBCA). LN status has been adopted as a critical element of staging systems. However, the influence of total lymph node count (TLNC) remains unclear. We determined the optimal minimum TLNC and compared the prognostic significance of LN status indices in GBCA. METHODS We retrospectively reviewed medical records of 128 patients with T2 or greater GBCA who underwent LN dissection. We analyzed overall survival (OS) and relevance of the number of metastatic LNs, ratio of metastatic LNs to retrieved LNs (LNR), and TLNC in predicting OS. RESULTS The median OS durations were 120, 35, and 18 months in T2, T3, and T4 GBCA. Five-year OS rates were 73%, 43%, and 0% in T2, T3, and T4 GBCA. LN status did not significantly impact OS in T2 or T4 GBCA. However, all LN indices were significantly correlated with OS in T3 GBCA. Furthermore, multivariate analysis revealed that a metastatic LN count of more than four and a TLNC of more than eight were independent prognostic factors of OS in T3 GBCA. CONCLUSIONS TLNC and the number of positive LNs may be more important prognostic factors than LNR in T3 GBCA. Additionally, accurate staging may not be achieved in cases of T3 GBCA if the total number of retrieved LNs is less than eight. Thus, to ensure proper staging, we recommend that surgeons harvest more than eight LNs in patients with T3 GBCA.
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Je UK, Cho HM, Hong DK, Cho HS, Park YO, Park CK, Kim KS, Lim HW, Kim GA, Park SY, Woo TH, Cho SI. 3D reconstruction based on compressed-sensing (CS)-based framework by using a dental panoramic detector. Phys Med 2015; 32:213-7. [PMID: 26494155 DOI: 10.1016/j.ejmp.2015.09.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 09/22/2015] [Accepted: 09/24/2015] [Indexed: 10/22/2022] Open
Abstract
In this work, we propose a practical method that can combine the two functionalities of dental panoramic and cone-beam CT (CBCT) features in one by using a single panoramic detector. We implemented a CS-based reconstruction algorithm for the proposed method and performed a systematic simulation to demonstrate its viability for 3D dental X-ray imaging. We successfully reconstructed volumetric images of considerably high accuracy by using a panoramic detector having an active area of 198.4 mm × 6.4 mm and evaluated the reconstruction quality as a function of the pitch (p) and the angle step (Δθ). Our simulation results indicate that the CS-based reconstruction almost completely recovered the phantom structures, as in CBCT, for p≤2.0 and θ≤6°, indicating that it seems very promising for accurate image reconstruction even for large-pitch and few-view data. We expect the proposed method to be applicable to developing a cost-effective, volumetric dental X-ray imaging system.
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Wijetunge DSS, Gongati S, DebRoy C, Kim KS, Couraud PO, Romero IA, Weksler B, Kariyawasam S. Characterizing the pathotype of neonatal meningitis causing Escherichia coli (NMEC). BMC Microbiol 2015; 15:211. [PMID: 26467858 PMCID: PMC4606507 DOI: 10.1186/s12866-015-0547-9] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 10/02/2015] [Indexed: 11/26/2022] Open
Abstract
Background Neonatal meningitis-causing Escherichia coli (NMEC) is the predominant Gram-negative bacterial pathogen associated with meningitis in newborn infants. High levels of heterogeneity and diversity have been observed in the repertoire of virulence traits and other characteristics among strains of NMEC making it difficult to define the NMEC pathotype. The objective of the present study was to identify genotypic and phenotypic characteristics of NMEC that can be used to distinguish them from commensal E. coli. Methods A total of 53 isolates of NMEC obtained from neonates with meningitis and 48 isolates of fecal E. coli obtained from healthy individuals (HFEC) were comparatively evaluated using five phenotypic (serotyping, serum bactericidal assay, biofilm assay, antimicorbial susceptibility testing, and in vitro cell invasion assay) and three genotypic (phylogrouping, virulence genotyping, and pulsed-field gel electrophoresis) methods. Results A majority (67.92 %) of NMEC belonged to B2 phylogenetic group whereas 59 % of HFEC belonged to groups A and D. Serotyping revealed that the most common O and H types present in NMEC tested were O1 (15 %), O8 (11.3 %), O18 (13.2 %), and H7 (25.3 %). In contrast, none of the HFEC tested belonged to O1 or O18 serogroups. The most common serogroup identified in HFEC was O8 (6.25 %). The virulence genotyping reflected that more than 70 % of NMEC carried kpsII, K1, neuC, iucC, sitA, and vat genes with only less than 27 % of HFEC possessing these genes. All NMEC and 79 % of HFEC tested were able to invade human cerebral microvascular endothelial cells. No statistically significant difference was observed in the serum resistance phenotype between NMEC and HFEC. The NMEC strains demonstrated a greater ability to form biofilms in Luria Bertani broth medium than did HFEC (79.2 % vs 39.9 %). Conclusion The results of our study demonstrated that virulence genotyping and phylogrouping may assist in defining the potential NMEC pathotype. Electronic supplementary material The online version of this article (doi:10.1186/s12866-015-0547-9) contains supplementary material, which is available to authorized users.
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Park SJ, Lee I, Bae DJ, Nam J, Park BJ, Han YH, Kim KS. Controlling the Properties of Graphene using CVD Method: Pristine and N-doped Graphene. ACTA ACUST UNITED AC 2015. [DOI: 10.18770/kepco.2015.01.01.169] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Shin JH, Han SG, Kim JK, Kim BW, Hwang JH, Lee JS, Lee JH, Baek JE, Kim TG, Kim KS, Lee HS, Song NW, Ahn K, Yu IJ. 5-Day repeated inhalation and 28-day post-exposure study of graphene. Nanotoxicology 2015; 9:1023-31. [PMID: 25697182 DOI: 10.3109/17435390.2014.998306] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Graphene has recently been attracting increasing attention due to its unique electronic and chemical properties and many potential applications in such fields as semiconductors, energy storage, flexible electronics, biosensors and medical imaging. However, the toxicity of graphene in the case of human exposure has not yet been clarified. Thus, a 5-day repeated inhalation toxicity study of graphene was conducted using a nose-only inhalation system for male Sprague-Dawley rats. A total of three groups (20 rats per group) were compared: (1) control (ambient air), (2) low concentration (0.68 ± 0.14 mg/m(3) graphene) and (3) high concentration (3.86 ± 0.94 mg/m(3) graphene). The rats were exposed to graphene for 6 h/day for 5 days, followed by recovery for 1, 3, 7 or 28 days. The bioaccumulation and macrophage ingestion of the graphene were evaluated in the rat lungs. The exposure to graphene did not change the body weights or organ weights of the rats after the 5-day exposure and during the recovery period. No statistically significant difference was observed in the levels of lactate dehydrogenase, protein and albumin between the exposed and control groups. However, graphene ingestion by alveolar macrophages was observed in the exposed groups. Therefore, these results suggest that the 5-day repeated exposure to graphene only had a minimal toxic effect at the concentrations and time points used in this study.
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Yeom M, Sur BJ, Park J, Cho SG, Lee B, Kim ST, Kim KS, Lee H, Hahm DH. Oral administration of Lactobacillus casei variety rhamnosus partially alleviates TMA-induced atopic dermatitis in mice through improving intestinal microbiota. J Appl Microbiol 2015; 119:560-70. [PMID: 25968453 DOI: 10.1111/jam.12844] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 04/23/2015] [Accepted: 05/08/2015] [Indexed: 01/19/2023]
Abstract
AIMS The purpose of this study was to investigate the effect of Lactobacillus casei variety rhamnosus (LCR35) on Atopic dermatitis (AD)-like symptoms in mice. METHODS AND RESULTS AD-like skin lesions in BALB/C mice were induced by sensitization and subsequent repeated challenges with trimellitic anhydride (TMA) for 10 days. LCR35 was orally administered to the mice once daily throughout the study. In the TMA-induced AD model, orally administered LCR35 suppressed significantly irritant-related scratching behaviour and skin dehydration as well as apparent severity of AD. LCR35 also significantly decreased serum levels of IgE and IL-4, but not IFN-γ, implying the restoration of TMA-induced disruption of Th1/Th2 balance. Quantitative real-time PCR targeting hypervariable regions of 16S rDNA gene of faecal microbiota indicated that the LCR35 treatment increased the population of Bifidobacterium, Lactobacilli, Enterococcus and Bacteroides fragilis group, but decreased those of Clostridium coccoides group. CONCLUSIONS LCR35 has the ability to suppress the development of AD in mice, possibly through the modulation of Th1/Th2 balance and gut microbiota. SIGNIFICANCE AND IMPACT OF THE STUDY LCR35 has a strong potential as a probiotic for preventing AD.
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Shin KO, Bae JY, Woo J, Jang KS, Kim KS, Park JS, Kim IK, Kang S. The effect of exercise on expression of myokine and angiogenesis mRNA in skeletal muscle of high fat diet induced obese rat. J Exerc Nutrition Biochem 2015. [DOI: 10.5717/jenb.2015.19.2.91] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Kwon H, Kim KS, Chun YM, Wu HG, Carlson JNK, Park JM, Kim JI. Evaluation of a commercial orthopaedic metal artefact reduction tool in radiation therapy of patients with head and neck cancer. Br J Radiol 2015; 88:20140536. [PMID: 25993487 DOI: 10.1259/bjr.20140536] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE To assess the image quality and dosimetric effects of the Philips orthopaedic metal artefact reduction (OMAR) (Philips Healthcare System, Cleveland, OH) function for reducing metal artefacts on CT images of head and neck (H&N) patients. METHODS 11 patients and a custom-built phantom with metal bead inserts (alumina, titanium, zirconia and chrome) were scanned. The image was reconstructed in two ways: with and without OMAR (OMAR and non-OMAR image). The mean and standard deviation values of CT Hounsfield unit (HU) for selected regions of interest of each case were investigated for both images. Volumetric modulated arc therapy plans were generated for all cases. Gamma analysis of each dose distribution pair in the patient (1%/1 mm criteria) and phantom (2%/2 mm and 3%/3 mm criteria) images was performed. The film measurements in phantom for two metal beads were conducted for evaluating the calculated dose on both OMAR and non-OMAR images. RESULTS In the OMAR images, noise values were generally reduced, and the mean HU became closer to the reference value (measured from patients without metal implants) in both patient and phantom cases. Although dosimetric difference was insignificant for the eight closed-mouth patients (γ = 99.4 ± 0.5%), there was a large discrepancy in dosimetric calculation between OMAR and non-OMAR images for the three opened-mouth patients (γ = 91.1%, 94.8% and 96.6%). Moreover, the calculated dose on the OMAR image is closer to the real delivered dose on a radiochromic film than was the dose from the non-OMAR image. CONCLUSION The OMAR algorithm increases the accuracy of CT HU and reduces the noise such that the entire radiation treatment planning process can be improved, especially for contouring and segmentation. ADVANCES IN KNOWLEDGE OMAR reconstruction is appropriate for the radiotherapy planning process of H&N patients, particularly of patients who use a bite block.
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Aguilar M, Aisa D, Alpat B, Alvino A, Ambrosi G, Andeen K, Arruda L, Attig N, Azzarello P, Bachlechner A, Barao F, Barrau A, Barrin L, Bartoloni A, Basara L, Battarbee M, Battiston R, Bazo J, Becker U, Behlmann M, Beischer B, Berdugo J, Bertucci B, Bigongiari G, Bindi V, Bizzaglia S, Bizzarri M, Boella G, de Boer W, Bollweg K, Bonnivard V, Borgia B, Borsini S, Boschini MJ, Bourquin M, Burger J, Cadoux F, Cai XD, Capell M, Caroff S, Casaus J, Cascioli V, Castellini G, Cernuda I, Cerreta D, Cervelli F, Chae MJ, Chang YH, Chen AI, Chen H, Cheng GM, Chen HS, Cheng L, Chou HY, Choumilov E, Choutko V, Chung CH, Clark C, Clavero R, Coignet G, Consolandi C, Contin A, Corti C, Cortina Gil E, Coste B, Creus W, Crispoltoni M, Cui Z, Dai YM, Delgado C, Della Torre S, Demirköz MB, Derome L, Di Falco S, Di Masso L, Dimiccoli F, Díaz C, von Doetinchem P, Donnini F, Du WJ, Duranti M, D'Urso D, Eline A, Eppling FJ, Eronen T, Fan YY, Farnesini L, Feng J, Fiandrini E, Fiasson A, Finch E, Fisher P, Galaktionov Y, Gallucci G, García B, García-López R, Gargiulo C, Gast H, Gebauer I, Gervasi M, Ghelfi A, Gillard W, Giovacchini F, Goglov P, Gong J, Goy C, Grabski V, Grandi D, Graziani M, Guandalini C, Guerri I, Guo KH, Haas D, Habiby M, Haino S, Han KC, He ZH, Heil M, Hoffman J, Hsieh TH, Huang ZC, Huh C, Incagli M, Ionica M, Jang WY, Jinchi H, Kanishev K, Kim GN, Kim KS, Kirn T, Kossakowski R, Kounina O, Kounine A, Koutsenko V, Krafczyk MS, La Vacca G, Laudi E, Laurenti G, Lazzizzera I, Lebedev A, Lee HT, Lee SC, Leluc C, Levi G, Li HL, Li JQ, Li Q, Li Q, Li TX, Li W, Li Y, Li ZH, Li ZY, Lim S, Lin CH, Lipari P, Lippert T, Liu D, Liu H, Lolli M, Lomtadze T, Lu MJ, Lu SQ, Lu YS, Luebelsmeyer K, Luo JZ, Lv SS, Majka R, Mañá C, Marín J, Martin T, Martínez G, Masi N, Maurin D, Menchaca-Rocha A, Meng Q, Mo DC, Morescalchi L, Mott P, Müller M, Ni JQ, Nikonov N, Nozzoli F, Nunes P, Obermeier A, Oliva A, Orcinha M, Palmonari F, Palomares C, Paniccia M, Papi A, Pauluzzi M, Pedreschi E, Pensotti S, Pereira R, Picot-Clemente N, Pilo F, Piluso A, Pizzolotto C, Plyaskin V, Pohl M, Poireau V, Postaci E, Putze A, Quadrani L, Qi XM, Qin X, Qu ZY, Räihä T, Rancoita PG, Rapin D, Ricol JS, Rodríguez I, Rosier-Lees S, Rozhkov A, Rozza D, Sagdeev R, Sandweiss J, Saouter P, Sbarra C, Schael S, Schmidt SM, Schulz von Dratzig A, Schwering G, Scolieri G, Seo ES, Shan BS, Shan YH, Shi JY, Shi XY, Shi YM, Siedenburg T, Son D, Spada F, Spinella F, Sun W, Sun WH, Tacconi M, Tang CP, Tang XW, Tang ZC, Tao L, Tescaro D, Ting SCC, Ting SM, Tomassetti N, Torsti J, Türkoğlu C, Urban T, Vagelli V, Valente E, Vannini C, Valtonen E, Vaurynovich S, Vecchi M, Velasco M, Vialle JP, Vitale V, Vitillo S, Wang LQ, Wang NH, Wang QL, Wang RS, Wang X, Wang ZX, Weng ZL, Whitman K, Wienkenhöver J, Wu H, Wu X, Xia X, Xie M, Xie S, Xiong RQ, Xin GM, Xu NS, Xu W, Yan Q, Yang J, Yang M, Ye QH, Yi H, Yu YJ, Yu ZQ, Zeissler S, Zhang JH, Zhang MT, Zhang XB, Zhang Z, Zheng ZM, Zhuang HL, Zhukov V, Zichichi A, Zimmermann N, Zuccon P, Zurbach C. Precision Measurement of the Proton Flux in Primary Cosmic Rays from Rigidity 1 GV to 1.8 TV with the Alpha Magnetic Spectrometer on the International Space Station. PHYSICAL REVIEW LETTERS 2015; 114:171103. [PMID: 25978222 DOI: 10.1103/physrevlett.114.171103] [Citation(s) in RCA: 129] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Indexed: 06/04/2023]
Abstract
A precise measurement of the proton flux in primary cosmic rays with rigidity (momentum/charge) from 1 GV to 1.8 TV is presented based on 300 million events. Knowledge of the rigidity dependence of the proton flux is important in understanding the origin, acceleration, and propagation of cosmic rays. We present the detailed variation with rigidity of the flux spectral index for the first time. The spectral index progressively hardens at high rigidities.
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Rhie YH, Lee SY, Kim KS. Seed dormancy and germination in Jeffersonia dubia (Berberidaceae) as affected by temperature and gibberellic acid. PLANT BIOLOGY (STUTTGART, GERMANY) 2015; 17:327-334. [PMID: 25319374 DOI: 10.1111/plb.12235] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2013] [Accepted: 06/23/2014] [Indexed: 06/04/2023]
Abstract
The genus Jeffersonia, which contains only two species, has a trans-Atlantic disjunct distribution. The aims of this study were to determine the requirements for breaking dormancy and germination of J. dubia seeds and to compare its dormancy characteristics with those of the congener in eastern North America. Ripe seeds of J. dubia contain an underdeveloped embryo and were permeable to water. In nature, seeds were dispersed in May, while embryos began to grow in September, and were fully elongated by late November. Germination started in March of the next year, and seeds emerged as seedlings soon after germination. In laboratory experiments, incubation at high temperatures (25 °C, 25/15 °C) for at least 8 weeks was required to initiate embryo growth, while a transfer to moderate temperatures (20/10 °C, 15/6 °C) was needed for the completion of embryo growth. At least 8 weeks at 5 °C was effective in overcoming physiological dormancy and for germination in seeds after the embryos had fully elongated. Thus, both high and low temperatures were essential to break dormancy. Gibberellic acid (GA3 ) treatment could substitute for the high temperature requirement, but not for the low temperature requirement. Based on the dormancy-breaking requirements, it is confirmed that the seeds have deep simple morphophysiological dormancy. This dormancy type is similar to that of seeds of the eastern North American species J. diphylla. Although seeds require 10-11 months from seed dispersal to germination in nature, under controlled conditions they required only 3 months after treatment with 1000 mg·l(-1) GA3 , followed by incubation at 15/6 °C. This represents practical knowledge for propagation of these plants from seed.
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Zhao L, He R, Zabet-Khosousi A, Kim KS, Schiros T, Roth M, Kim P, Flynn GW, Pinczuk A, Pasupathy AN. Dopant segregation in polycrystalline monolayer graphene. NANO LETTERS 2015; 15:1428-1436. [PMID: 25625227 DOI: 10.1021/nl504875x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Heterogeneity in dopant concentration has long been important to the electronic properties in chemically doped materials. In this work, we experimentally demonstrate that during the chemical vapor deposition process, in contrast to three-dimensional polycrystals, the substitutional nitrogen atoms avoid crystal grain boundaries and edges over micron length scales while distributing uniformly in the interior of each grain. This phenomenon is universally observed independent of the details of the growth procedure such as temperature, pressure, substrate, and growth precursor.
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Yu YJ, Kim KS, Nam J, Kwon SR, Byun H, Lee K, Ryou JH, Dupuis RD, Kim J, Ahn G, Ryu S, Ryu MY, Kim JS. Temperature-dependent resonance energy transfer from semiconductor quantum wells to graphene. NANO LETTERS 2015; 15:896-902. [PMID: 25562118 DOI: 10.1021/nl503624j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Resonance energy transfer (RET) has been employed for interpreting the energy interaction of graphene combined with semiconductor materials such as nanoparticles and quantum-well (QW) heterostructures. Especially, for the application of graphene as a transparent electrode for semiconductor light emitting diodes, the mechanism of exciton recombination processes such as RET in graphene-semiconductor QW heterojunctions should be understood clearly. Here, we characterized the temperature-dependent RET behaviors in graphene/semiconductor QW heterostructures. We then observed the tuning of the RET efficiency from 5% to 30% in graphene/QW heterostructures with ∼60 nm dipole-dipole coupled distance at temperatures of 300 to 10 K. This survey allows us to identify the roles of localized and free excitons in the RET process from the QWs to graphene as a function of temperature.
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Kim SY, Kim HJ, Park SY, Lee DE, Kim KS, Park SY, Kim MH, Kwak DW, Ryu HM. Quantification of the placental epigenetic signature of the SERPINB5 gene in maternal plasma of pregnancies complicated by small for gestational age. Placenta 2015; 36:131-7. [PMID: 25553975 DOI: 10.1016/j.placenta.2014.09.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 08/20/2014] [Accepted: 09/11/2014] [Indexed: 11/28/2022]
Abstract
INTRODUCTION To investigate the association between pregnancies with small for gestational age (SGA) neonates and the concentration of cell-free fetal DNA or cell-free total DNA in maternal plasma during the first and second trimesters using tissue-specific epigenetic characteristics of the SERPINB5 gene. METHODS A nested case-control study was conducted with maternal plasma collected at 11 to 26 gestational weeks from 51 women with SGA neonates and 102 controls. We performed a real-time quantitative methylation-specific PCR to quantify concentrations of unmethylated-SERPINB5 (U-SERPINB5) as a cell-free fetal DNA marker and methylated-SERPINB5 (M-SERPINB5) as a cell-free total DNA marker. RESULTS A positive correlation was observed between U-SERPINB5 and M-SERPINB5 concentrations in both control (r = 0.363, p < 0.001) and SGA groups (r = 0.548, p < 0.001). Moreover, the concentration of U-SERPINB5 or M-SERPINB5 was significantly positive correlated with gestational age at sampling in both controls (U-SERPINB5: r = 0.397, p < 0.001; M-SERPINB5: r = 0.275, p = 0.005) and SGA (U-SERPINB5: r = 0.274, p = 0.052; M-SERPINB5: r = 0.439, p = 0.001). However, the concentration of U-SERPINB5 or M-SERPINB5 was not correlated with birthweight. At 11-14 weeks, U-SERPINB5 and M-SERPINB5 concentrations in SGA did not differ significantly from those of controls. There were also no statistically significant differences in the concentrations of U-SERPINB5 and M-SERPINB5 between SGA and controls at 15-26 weeks of gestation. DISCUSSION Our findings suggest that U-SERPINB5 and M-SERPINB5 concentrations in maternal plasma during early pregnancy are not associated with pregnancies who delivered SGA neonates.
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Khan MF, Iqbal MZ, Iqbal MW, Iermolenko VM, Waseem Khalil HM, Nam J, Kim KS, Noh H, Eom J. Stable and reversible doping of graphene by using KNO3 solution and photo-desorption current response. RSC Adv 2015. [DOI: 10.1039/c5ra08136j] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We found stable n-type doping and carrier mobility improvement of graphene by using KNO3 solution and investigated photo-desorption current response.
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Kang TS, Hong OS, Kim KS, Yoon CS. Hearing among male firefighters: a comparison with hearing data from screened and unscreened male population. JOURNAL OF EXPOSURE SCIENCE & ENVIRONMENTAL EPIDEMIOLOGY 2015; 25:106-12. [PMID: 25352160 PMCID: PMC4269805 DOI: 10.1038/jes.2014.72] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Accepted: 08/28/2014] [Indexed: 06/04/2023]
Abstract
We investigated whether hearing loss is associated with firefighting. We conducted cross-sectional study comparing hearing threshold levels (HTLs) of 912 male firefighters with two hearing databases obtained from an otologically normal male Korean population (KONP) and a non-industrial noise-exposed male Korean population (KNINEP), considering age and the main roles of firefighters. Firefighters' age-adjusted HTLs were significantly worse than those of KONP (prevalence ratio (PR)=5.29, P<0.001)but not different from those of KNINEP (PR=0.99, P=0.550). Rescuers (PR=1.005, P<0.001) had worse hearing than the KNINEP after age adjustment. Comparison of firefighters' HTLs (50th and 90th percentiles) with those of KONP and KNINEP by age and frequency showed that firefighters' HTLs had significant increases (poorer hearing) across most age groups and frequencies compared with KONP. Compared with KNINEP, firefighters' HTLs were worse in the younger age groups (<45 years) but not different in the older age groups (>45 years). In conclusion, the hearing thresholds of younger firefighters and rescuers were worse than expected by normal aging alone. Future research should include longitudinal studies to consider variable risk factors, such as military service, smoking, and so on.
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Aguilar M, Aisa D, Alpat B, Alvino A, Ambrosi G, Andeen K, Arruda L, Attig N, Azzarello P, Bachlechner A, Barao F, Barrau A, Barrin L, Bartoloni A, Basara L, Battarbee M, Battiston R, Bazo J, Becker U, Behlmann M, Beischer B, Berdugo J, Bertucci B, Bigongiari G, Bindi V, Bizzaglia S, Bizzarri M, Boella G, de Boer W, Bollweg K, Bonnivard V, Borgia B, Borsini S, Boschini MJ, Bourquin M, Burger J, Cadoux F, Cai XD, Capell M, Caroff S, Casaus J, Cascioli V, Castellini G, Cernuda I, Cervelli F, Chae MJ, Chang YH, Chen AI, Chen H, Cheng GM, Chen HS, Cheng L, Chikanian A, Chou HY, Choumilov E, Choutko V, Chung CH, Clark C, Clavero R, Coignet G, Consolandi C, Contin A, Corti C, Coste B, Crispoltoni M, Cui Z, Dai M, Delgado C, Della Torre S, Demirköz MB, Derome L, Di Falco S, Di Masso L, Dimiccoli F, Díaz C, von Doetinchem P, Donnini F, Du WJ, Duranti M, D'Urso D, Eline A, Eppling FJ, Eronen T, Fan YY, Farnesini L, Feng J, Fiandrini E, Fiasson A, Finch E, Fisher P, Galaktionov Y, Gallucci G, García B, García-López R, Gargiulo C, Gast H, Gebauer I, Gervasi M, Ghelfi A, Gillard W, Giovacchini F, Goglov P, Gong J, Goy C, Grabski V, Grandi D, Graziani M, Guandalini C, Guerri I, Guo KH, Habiby M, Haino S, Han KC, He ZH, Heil M, Hoffman J, Hsieh TH, Huang ZC, Huh C, Incagli M, Ionica M, Jang WY, Jinchi H, Kanishev K, Kim GN, Kim KS, Kirn T, Kossakowski R, Kounina O, Kounine A, Koutsenko V, Krafczyk MS, Kunz S, La Vacca G, Laudi E, Laurenti G, Lazzizzera I, Lebedev A, Lee HT, Lee SC, Leluc C, Li HL, Li JQ, Li Q, Li Q, Li TX, Li W, Li Y, Li ZH, Li ZY, Lim S, Lin CH, Lipari P, Lippert T, Liu D, Liu H, Lomtadze T, Lu MJ, Lu YS, Luebelsmeyer K, Luo F, Luo JZ, Lv SS, Majka R, Malinin A, Mañá C, Marín J, Martin T, Martínez G, Masi N, Maurin D, Menchaca-Rocha A, Meng Q, Mo DC, Morescalchi L, Mott P, Müller M, Ni JQ, Nikonov N, Nozzoli F, Nunes P, Obermeier A, Oliva A, Orcinha M, Palmonari F, Palomares C, Paniccia M, Papi A, Pauluzzi M, Pedreschi E, Pensotti S, Pereira R, Pilo F, Piluso A, Pizzolotto C, Plyaskin V, Pohl M, Poireau V, Postaci E, Putze A, Quadrani L, Qi XM, Räihä T, Rancoita PG, Rapin D, Ricol JS, Rodríguez I, Rosier-Lees S, Rozhkov A, Rozza D, Sagdeev R, Sandweiss J, Saouter P, Sbarra C, Schael S, Schmidt SM, Schuckardt D, Schulz von Dratzig A, Schwering G, Scolieri G, Seo ES, Shan BS, Shan YH, Shi JY, Shi XY, Shi YM, Siedenburg T, Son D, Spada F, Spinella F, Sun W, Sun WH, Tacconi M, Tang CP, Tang XW, Tang ZC, Tao L, Tescaro D, Ting SCC, Ting SM, Tomassetti N, Torsti J, Türkoğlu C, Urban T, Vagelli V, Valente E, Vannini C, Valtonen E, Vaurynovich S, Vecchi M, Velasco M, Vialle JP, Wang LQ, Wang QL, Wang RS, Wang X, Wang ZX, Weng ZL, Whitman K, Wienkenhöver J, Wu H, Xia X, Xie M, Xie S, Xiong RQ, Xin GM, Xu NS, Xu W, Yan Q, Yang J, Yang M, Ye QH, Yi H, Yu YJ, Yu ZQ, Zeissler S, Zhang JH, Zhang MT, Zhang XB, Zhang Z, Zheng ZM, Zhuang HL, Zhukov V, Zichichi A, Zimmermann N, Zuccon P, Zurbach C. Precision Measurement of the (e^{+}+e^{-}) Flux in Primary Cosmic Rays from 0.5 GeV to 1 TeV with the Alpha Magnetic Spectrometer on the International Space Station. PHYSICAL REVIEW LETTERS 2014; 113:221102. [PMID: 25494065 DOI: 10.1103/physrevlett.113.221102] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Indexed: 06/04/2023]
Abstract
We present a measurement of the cosmic ray (e^{+}+e^{-}) flux in the range 0.5 GeV to 1 TeV based on the analysis of 10.6 million (e^{+}+e^{-}) events collected by AMS. The statistics and the resolution of AMS provide a precision measurement of the flux. The flux is smooth and reveals new and distinct information. Above 30.2 GeV, the flux can be described by a single power law with a spectral index γ=-3.170±0.008(stat+syst)±0.008(energy scale).
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Choi DS, Kim KS, Kim H, Kim Y, Kim T, Rhy SH, Yang CM, Yoon DH, Yang WS. Effect of cooling condition on chemical vapor deposition synthesis of graphene on copper catalyst. ACS APPLIED MATERIALS & INTERFACES 2014; 6:19574-19578. [PMID: 25386721 DOI: 10.1021/am503698h] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Here, we show that chemical vapor deposition growth of graphene on copper foil is strongly affected by the cooling conditions. Variation of cooling conditions such as cooling rate and hydrocarbon concentration in the cooling step has yielded graphene islands with different sizes, density of nuclei, and growth rates. The nucleation site density on Cu substrate is greatly reduced when the fast cooling condition was applied, while continuing methane flow during the cooling step also influences the nucleation and growth rate. Raman spectra indicate that the graphene synthesized under fast cooling condition and methane flow on cool-down exhibit superior quality of graphene. Further studies suggest that careful control of the cooling rate and CH4 gas flow on the cooling step yield a high quality of graphene.
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Moser S, Moreschini L, Yang HY, Innocenti D, Fuchs F, Hansen NH, Chang YJ, Kim KS, Walter AL, Bostwick A, Rotenberg E, Mila F, Grioni M. Angle-resolved photoemission spectroscopy of tetragonal CuO: evidence for intralayer coupling between cupratelike sublattices. PHYSICAL REVIEW LETTERS 2014; 113:187001. [PMID: 25396389 DOI: 10.1103/physrevlett.113.187001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Indexed: 06/04/2023]
Abstract
We investigate by angle-resolved photoemission the electronic structure of in situ grown tetragonal CuO, a synthetic quasi-two-dimensional edge-sharing cuprate. We show that, in spite of the very different nature of the copper oxide layers, with twice as many Cu in the CuO layers of tetragonal CuO as compared to the CuO(2) layers of the high-T(c) cuprates, the low-energy electronic excitations are surprisingly similar, with a Zhang-Rice singlet dispersing on weakly coupled cupratelike sublattices. This system should thus be considered as a member of the high-T(c) cuprate family, with, however, interesting differences due to the intralayer coupling between the cupratelike sublattices.
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Aguilar M, Aisa D, Alvino A, Ambrosi G, Andeen K, Arruda L, Attig N, Azzarello P, Bachlechner A, Barao F, Barrau A, Barrin L, Bartoloni A, Basara L, Battarbee M, Battiston R, Bazo J, Becker U, Behlmann M, Beischer B, Berdugo J, Bertucci B, Bigongiari G, Bindi V, Bizzaglia S, Bizzarri M, Boella G, de Boer W, Bollweg K, Bonnivard V, Borgia B, Borsini S, Boschini MJ, Bourquin M, Burger J, Cadoux F, Cai XD, Capell M, Caroff S, Casaus J, Cascioli V, Castellini G, Cernuda I, Cervelli F, Chae MJ, Chang YH, Chen AI, Chen H, Cheng GM, Chen HS, Cheng L, Chikanian A, Chou HY, Choumilov E, Choutko V, Chung CH, Clark C, Clavero R, Coignet G, Consolandi C, Contin A, Corti C, Coste B, Cui Z, Dai M, Delgado C, Della Torre S, Demirköz MB, Derome L, Di Falco S, Di Masso L, Dimiccoli F, Díaz C, von Doetinchem P, Du WJ, Duranti M, D'Urso D, Eline A, Eppling FJ, Eronen T, Fan YY, Farnesini L, Feng J, Fiandrini E, Fiasson A, Finch E, Fisher P, Galaktionov Y, Gallucci G, García B, García-López R, Gast H, Gebauer I, Gervasi M, Ghelfi A, Gillard W, Giovacchini F, Goglov P, Gong J, Goy C, Grabski V, Grandi D, Graziani M, Guandalini C, Guerri I, Guo KH, Habiby M, Haino S, Han KC, He ZH, Heil M, Hoffman J, Hsieh TH, Huang ZC, Huh C, Incagli M, Ionica M, Jang WY, Jinchi H, Kanishev K, Kim GN, Kim KS, Kirn T, Kossakowski R, Kounina O, Kounine A, Koutsenko V, Krafczyk MS, Kunz S, La Vacca G, Laudi E, Laurenti G, Lazzizzera I, Lebedev A, Lee HT, Lee SC, Leluc C, Li HL, Li JQ, Li Q, Li Q, Li TX, Li W, Li Y, Li ZH, Li ZY, Lim S, Lin CH, Lipari P, Lippert T, Liu D, Liu H, Lomtadze T, Lu MJ, Lu YS, Luebelsmeyer K, Luo F, Luo JZ, Lv SS, Majka R, Malinin A, Mañá C, Marín J, Martin T, Martínez G, Masi N, Maurin D, Menchaca-Rocha A, Meng Q, Mo DC, Morescalchi L, Mott P, Müller M, Ni JQ, Nikonov N, Nozzoli F, Nunes P, Obermeier A, Oliva A, Orcinha M, Palmonari F, Palomares C, Paniccia M, Papi A, Pedreschi E, Pensotti S, Pereira R, Pilo F, Piluso A, Pizzolotto C, Plyaskin V, Pohl M, Poireau V, Postaci E, Putze A, Quadrani L, Qi XM, Rancoita PG, Rapin D, Ricol JS, Rodríguez I, Rosier-Lees S, Rozhkov A, Rozza D, Sagdeev R, Sandweiss J, Saouter P, Sbarra C, Schael S, Schmidt SM, Schuckardt D, Schulz von Dratzig A, Schwering G, Scolieri G, Seo ES, Shan BS, Shan YH, Shi JY, Shi XY, Shi YM, Siedenburg T, Son D, Spada F, Spinella F, Sun W, Sun WH, Tacconi M, Tang CP, Tang XW, Tang ZC, Tao L, Tescaro D, Ting SCC, Ting SM, Tomassetti N, Torsti J, Türkoğlu C, Urban T, Vagelli V, Valente E, Vannini C, Valtonen E, Vaurynovich S, Vecchi M, Velasco M, Vialle JP, Wang LQ, Wang QL, Wang RS, Wang X, Wang ZX, Weng ZL, Whitman K, Wienkenhöver J, Wu H, Xia X, Xie M, Xie S, Xiong RQ, Xin GM, Xu NS, Xu W, Yan Q, Yang J, Yang M, Ye QH, Yi H, Yu YJ, Yu ZQ, Zeissler S, Zhang JH, Zhang MT, Zhang XB, Zhang Z, Zheng ZM, Zhuang HL, Zhukov V, Zichichi A, Zimmermann N, Zuccon P, Zurbach C. Electron and positron fluxes in primary cosmic rays measured with the alpha magnetic spectrometer on the international space station. PHYSICAL REVIEW LETTERS 2014; 113:121102. [PMID: 25279617 DOI: 10.1103/physrevlett.113.121102] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Indexed: 06/03/2023]
Abstract
Precision measurements by the Alpha Magnetic Spectrometer on the International Space Station of the primary cosmic-ray electron flux in the range 0.5 to 700 GeV and the positron flux in the range 0.5 to 500 GeV are presented. The electron flux and the positron flux each require a description beyond a single power-law spectrum. Both the electron flux and the positron flux change their behavior at ∼30 GeV but the fluxes are significantly different in their magnitude and energy dependence. Between 20 and 200 GeV the positron spectral index is significantly harder than the electron spectral index. The determination of the differing behavior of the spectral indices versus energy is a new observation and provides important information on the origins of cosmic-ray electrons and positrons.
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Accardo L, Aguilar M, Aisa D, Alpat B, Alvino A, Ambrosi G, Andeen K, Arruda L, Attig N, Azzarello P, Bachlechner A, Barao F, Barrau A, Barrin L, Bartoloni A, Basara L, Battarbee M, Battiston R, Bazo J, Becker U, Behlmann M, Beischer B, Berdugo J, Bertucci B, Bigongiari G, Bindi V, Bizzaglia S, Bizzarri M, Boella G, de Boer W, Bollweg K, Bonnivard V, Borgia B, Borsini S, Boschini MJ, Bourquin M, Burger J, Cadoux F, Cai XD, Capell M, Caroff S, Carosi G, Casaus J, Cascioli V, Castellini G, Cernuda I, Cerreta D, Cervelli F, Chae MJ, Chang YH, Chen AI, Chen H, Cheng GM, Chen HS, Cheng L, Chikanian A, Chou HY, Choumilov E, Choutko V, Chung CH, Cindolo F, Clark C, Clavero R, Coignet G, Consolandi C, Contin A, Corti C, Coste B, Cui Z, Dai M, Delgado C, Della Torre S, Demirköz MB, Derome L, Di Falco S, Di Masso L, Dimiccoli F, Díaz C, von Doetinchem P, Du WJ, Duranti M, D'Urso D, Eline A, Eppling FJ, Eronen T, Fan YY, Farnesini L, Feng J, Fiandrini E, Fiasson A, Finch E, Fisher P, Galaktionov Y, Gallucci G, García B, García-López R, Gast H, Gebauer I, Gervasi M, Ghelfi A, Gillard W, Giovacchini F, Goglov P, Gong J, Goy C, Grabski V, Grandi D, Graziani M, Guandalini C, Guerri I, Guo KH, Haas D, Habiby M, Haino S, Han KC, He ZH, Heil M, Henning R, Hoffman J, Hsieh TH, Huang ZC, Huh C, Incagli M, Ionica M, Jang WY, Jinchi H, Kanishev K, Kim GN, Kim KS, Kirn T, Kossakowski R, Kounina O, Kounine A, Koutsenko V, Krafczyk MS, Kunz S, La Vacca G, Laudi E, Laurenti G, Lazzizzera I, Lebedev A, Lee HT, Lee SC, Leluc C, Levi G, Li HL, Li JQ, Li Q, Li Q, Li TX, Li W, Li Y, Li ZH, Li ZY, Lim S, Lin CH, Lipari P, Lippert T, Liu D, Liu H, Lolli M, Lomtadze T, Lu MJ, Lu YS, Luebelsmeyer K, Luo F, Luo JZ, Lv SS, Majka R, Malinin A, Mañá C, Marín J, Martin T, Martínez G, Masi N, Massera F, Maurin D, Menchaca-Rocha A, Meng Q, Mo DC, Monreal B, Morescalchi L, Mott P, Müller M, Ni JQ, Nikonov N, Nozzoli F, Nunes P, Obermeier A, Oliva A, Orcinha M, Palmonari F, Palomares C, Paniccia M, Papi A, Pauluzzi M, Pedreschi E, Pensotti S, Pereira R, Pilastrini R, Pilo F, Piluso A, Pizzolotto C, Plyaskin V, Pohl M, Poireau V, Postaci E, Putze A, Quadrani L, Qi XM, Rancoita PG, Rapin D, Ricol JS, Rodríguez I, Rosier-Lees S, Rossi L, Rozhkov A, Rozza D, Rybka G, Sagdeev R, Sandweiss J, Saouter P, Sbarra C, Schael S, Schmidt SM, Schuckardt D, Schulz von Dratzig A, Schwering G, Scolieri G, Seo ES, Shan BS, Shan YH, Shi JY, Shi XY, Shi YM, Siedenburg T, Son D, Spada F, Spinella F, Sun W, Sun WH, Tacconi M, Tang CP, Tang XW, Tang ZC, Tao L, Tescaro D, Ting SCC, Ting SM, Tomassetti N, Torsti J, Türkoğlu C, Urban T, Vagelli V, Valente E, Vannini C, Valtonen E, Vaurynovich S, Vecchi M, Velasco M, Vialle JP, Vitale V, Volpini G, Wang LQ, Wang QL, Wang RS, Wang X, Wang ZX, Weng ZL, Whitman K, Wienkenhöver J, Wu H, Wu KY, Xia X, Xie M, Xie S, Xiong RQ, Xin GM, Xu NS, Xu W, Yan Q, Yang J, Yang M, Ye QH, Yi H, Yu YJ, Yu ZQ, Zeissler S, Zhang JH, Zhang MT, Zhang XB, Zhang Z, Zheng ZM, Zhou F, Zhuang HL, Zhukov V, Zichichi A, Zimmermann N, Zuccon P, Zurbach C. High statistics measurement of the positron fraction in primary cosmic rays of 0.5-500 GeV with the alpha magnetic spectrometer on the international space station. PHYSICAL REVIEW LETTERS 2014; 113:121101. [PMID: 25279616 DOI: 10.1103/physrevlett.113.121101] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Indexed: 06/03/2023]
Abstract
A precision measurement by AMS of the positron fraction in primary cosmic rays in the energy range from 0.5 to 500 GeV based on 10.9 million positron and electron events is presented. This measurement extends the energy range of our previous observation and increases its precision. The new results show, for the first time, that above ∼200 GeV the positron fraction no longer exhibits an increase with energy.
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