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Ke CL, Liao YT, Lin CH. MSS2 maintains mitochondrial function and is required for chitosan resistance, invasive growth, biofilm formation and virulence in Candida albicans. Virulence 2021; 12:281-297. [PMID: 33427576 PMCID: PMC7808435 DOI: 10.1080/21505594.2020.1870082] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Candida albicans is the most prevalent fungal pathogen in humans, particularly in immunocompromised patients. In this study, by screening a C. albicans mutant library, we first identified that the MSS2 gene, an ortholog of Saccharomyces cerevisiae MSS2 required for mitochondrial respiration, mediates chitosan resistance. Upon treatment with 0.2% chitosan, the growth of mss2Δ strains was strikingly impaired, and MSS2 expression was significantly repressed by chitosan. Furthermore, mss2Δ strains exhibited slow growth on medium supplemented with glycerol as the sole carbon source. Similar to the chitosan-treated wild-type strain, the mss2Δ strain exhibited a significantly impaired ATP production ability. These data suggest that an antifungal mechanism of chitosan against C. albicans acts by inhibiting MSS2 gene expression, leading to repression of mitochondrial function. Normal respiratory function is suggested to be required for fungal virulence. Interestingly, the mss2Δ mutant strains exhibited significantly impaired invasive ability in vitro and ex vivo but retained normal hyphal development ability in liquid medium. Furthermore, the MSS2 deletion strains could not form robust biofilms and exhibited significantly reduced virulence. Collectively, these results demonstrated that the antifungal effect of chitosan against C. albicans is mediated via inhibition of mitochondrial biogenesis. These data may provide another strategy for antifungal drug development via inhibition of fungal mitochondria.
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Lew SQ, Lin CH. N-acetylglucosamine-mediated morphological transition in Candida albicans and Candida tropicalis. Curr Genet 2021; 67:249-254. [PMID: 33388851 DOI: 10.1007/s00294-020-01138-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 11/20/2020] [Accepted: 11/23/2020] [Indexed: 10/22/2022]
Abstract
Morphological transitions in Candida species are key factors in facilitating invasion and adapting to environmental changes. N-acetylglucosamine (GlcNAc) is a monosaccharide signalling molecule that can regulate morphological transitions in Candida albicans and Candida tropicalis. Interestingly, although the uptake and metabolic pathways of GlcNAc and GlcNAc-mediated white-to-opaque cell switching are similar between the two Candida species, GlcNAc induces hyphal development in C. albicans, whereas it suppresses hyphal development in C. tropicalis. These findings indicate that the characteristics of C. albicans and C. tropicalis in response to GlcNAc are remarkably different. Here, we compare the conserved and divergent GlcNAc-mediated signalling pathways and catabolism between the two Candida species. Deletion of NGT1, a GlcNAc transportation gene, inhibited hyphal formation in C. albicans but promoted hyphal development in C. tropicalis. To further understand these opposite effects on filamentous growth in response to GlcNAc in the two Candida species, the cyclic adenosine monophosphate/protein kinase A (cAMP/PKA) signalling pathways in both C. albicans and C. tropicalis were compared. Interestingly, GlcNAc activated the cAMP/PKA signalling pathway of the two Candida species, suggesting that the hyphal development-regulated circuit is remarkably diverse between the two species. Indeed, the Ndt80-like gene REP1, which is critical for regulating GlcNAc catabolism, exhibits distinct roles in the hyphal development of C. albicans and C. tropicalis. These data suggest possible reasons for the divergent hyphal growth response in C. albicans and C. tropicalis upon GlcNAc induction.
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Tang YH, Chiu YC, Luo D, Lien JY, Yi RH, Lin CH, Yang ZP, Lu CW, Su HC. Hybrid White-Light-Emitting Electrochemical Cells Based on a Blue Cationic Iridium(III) Complex and Red Quantum Dots. Chemistry 2020; 26:13668-13676. [PMID: 33463782 DOI: 10.1002/chem.202001994] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Indexed: 01/26/2023]
Abstract
Solid-state white light-emitting electrochemical cells (LECs) show promising advantages of simple solution fabrication processes, low operation voltage, and compatibility with air-stable cathode metals, which are required for lighting applications. To date, white LECs based on ionic transition metal complexes (iTMCs) have shown higher device efficiencies than white LECs employing other types of materials. However, lower emission efficiencies of red iTMCs limit further improvement in device performance. As an alternative, efficient red CdZnSeS/ZnS core/shell quantum dots were integrated with a blue iTMC to form a hybrid white LEC in this work. By achieving good carrier balance in an appropriate device architecture, a peak external quantum efficiency and power efficiency of 11.2 % and 15.1 lm W-1, respectively, were reached. Such device efficiency is indeed higher than those of the reported white LECs based on host-guest iTMCs. Time- and voltage-dependent electroluminescence (EL) characteristics of the hybrid white LECs were studied by means of the temporal evolution of the emission-zone position extracted by fitting the simulated and measured EL spectra. The working principle of the hybrid white LECs was clarified, and the high device efficiency makes potential new white-emitting devices suitable for solid-state lighting technology possible.
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Song YD, Hsu CC, Lew SQ, Lin CH. Candida tropicalis RON1 is required for hyphal formation, biofilm development, and virulence but is dispensable for N-acetylglucosamine catabolism. Med Mycol 2020; 59:379-391. [PMID: 32712662 DOI: 10.1093/mmy/myaa063] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 06/29/2020] [Accepted: 07/08/2020] [Indexed: 01/05/2023] Open
Abstract
NDT80-like family genes are highly conserved across a large group of fungi, but the functions of each Ndt80 protein are diverse and have evolved differently among yeasts and pathogens. The unique NDT80 gene in budding yeast is required for sexual reproduction, whereas three NDT80-like genes, namely, NDT80, REP1, and RON1, found in Candida albicans exhibit distinct functions. Notably, it was suggested that REP1, rather than RON1, is required for N-acetylglucosamine (GlcNAc) catabolism. Although Candida tropicalis, a widely dispersed fungal pathogen in tropical and subtropical areas, is closely related to Candida albicans, its phenotypic, pathogenic and environmental adaptation characteristics are remarkably divergent. In this study, we focused on the Ron1 transcription factor in C. tropicalis. Protein alignment showed that C. tropicalis Ron1 (CtRon1) shares 39.7% identity with C. albicans Ron1 (CaRon1). Compared to the wild-type strain, the C. tropicalis ron1Δ strains exhibited normal growth in different carbon sources and had similar expression levels of several GlcNAc catabolic genes during GlcNAc treatment. In contrast, C. tropicalis REP1 is responsible for GlcNAc catabolism and is involved in GlcNAc catabolic gene expressions, similar to C. albicans Rep1. However, REP1 deletion strains in C. tropicalis promote hyphal development in GlcNAc with low glucose content. Interestingly, CtRON1, but not CaRON1, deletion mutants exhibited significantly impaired hyphal growth and biofilm formation. As expected, CtRON1 was required for full virulence. Together, the results of this study showed divergent functions of CtRon1 compared to CaRon1; CtRon1 plays a key role in yeast-hyphal dimorphism, biofilm formation and virulence. LAY ABSTRACT In this study, we identified the role of RON1, an NDT80-like gene, in Candida tropicalis. Unlike the gene in Candida albicans, our studies showed that RON1 is a key regulator of hyphal formation, biofilm development and virulence but is dispensable for N-acetylglucosamine catabolism in C. tropicalis.
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Shen M, Li PT, Wu YJ, Lin CH, Chai E, Chang TC, Chen CT. The antifungal activities and biological consequences of BMVC-12C-P, a carbazole derivative against Candida species. Med Mycol 2020; 58:521-529. [PMID: 31281934 DOI: 10.1093/mmy/myz071] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 05/19/2019] [Accepted: 06/05/2019] [Indexed: 11/14/2022] Open
Abstract
Fungal infections, particularly Candida species, have increased worldwide and caused high morbidity and mortality rates. The toxicity and development of resistance in present antifungal drugs justify the need of new drugs with different mechanism of action. BMVC-12C-P, a carbazole-type compound, has been found to dysfunction mitochondria. BMVC-12C-P displayed the strongest antifungal activities among all of the BMVC derivatives. The minimal inhibitory concentration (MIC) of BMVC-12C-P against Candida species ranged from 1 to 2 μg/ml. Fluconazole-resistant clinical isolates of Candida species were highly susceptible to BMVC-12C-P. The potent fungicidal activity of BMVC-12C-P relates to its impairing mitochondrial function. Furthermore, we found that the hyphae growth and biofilm formation were suppressed in C. albicans survived from BMVC-12C-P treatment. This study demonstrates the potential of BMVC-12C-P as an antifungal agent for treating Candida infections.
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Aguilar M, Ali Cavasonza L, Ambrosi G, Arruda L, Attig N, Barao F, Barrin L, Bartoloni A, Başeğmez-du Pree S, Battiston R, Becker U, Behlmann M, Beischer B, Berdugo J, Bertucci B, Bindi V, de Boer W, Bollweg K, Borgia B, Boschini MJ, Bourquin M, Bueno EF, Burger J, Burger WJ, Burmeister S, Cai XD, Capell M, Casaus J, Castellini G, Cervelli F, Chang YH, Chen GM, Chen HS, Chen Y, Cheng L, Chou HY, Chouridou S, Choutko V, Chung CH, Clark C, Coignet G, Consolandi C, Contin A, Corti C, Cui Z, Dadzie K, Dai YM, Delgado C, Della Torre S, Demirköz MB, Derome L, Di Falco S, Di Felice V, Díaz C, Dimiccoli F, von Doetinchem P, Dong F, Donnini F, Duranti M, Egorov A, Eline A, Feng J, Fiandrini E, Fisher P, Formato V, Freeman C, Galaktionov Y, Gámez C, García-López RJ, Gargiulo C, Gast H, Gebauer I, Gervasi M, Giovacchini F, Gómez-Coral DM, Gong J, Goy C, Grabski V, Grandi D, Graziani M, Guo KH, Haino S, Han KC, Hashmani RK, He ZH, Heber B, Hsieh TH, Hu JY, Huang ZC, Incagli M, Jang WY, Jia Y, Jinchi H, Kanishev K, Khiali B, Kim GN, Kirn T, Konyushikhin M, Kounina O, Kounine A, Koutsenko V, Kuhlman A, Kulemzin A, La Vacca G, Laudi E, Laurenti G, Lazzizzera I, Lebedev A, Lee HT, Lee SC, Li JQ, Li M, Li Q, Li S, Li TX, Li ZH, Light C, Lin CH, Lippert T, Liu Z, Lu SQ, Lu YS, Luebelsmeyer K, Luo JZ, Lyu SS, Machate F, Mañá C, Marín J, Marquardt J, Martin T, Martínez G, Masi N, Maurin D, Menchaca-Rocha A, Meng Q, Mo DC, Molero M, Mott P, Mussolin L, Ni JQ, Nikonov N, Nozzoli F, Oliva A, Orcinha M, Palermo M, Palmonari F, Paniccia M, Pashnin A, Pauluzzi M, Pensotti S, Phan HD, Piandani R, Plyaskin V, Poluianov S, Qi XM, Qin X, Qu ZY, Quadrani L, Rancoita PG, Rapin D, Reina Conde A, Rosier-Lees S, Rozhkov A, Rozza D, Sagdeev R, Schael S, Schmidt SM, Schulz von Dratzig A, Schwering G, Seo ES, Shan BS, Shi JY, Siedenburg T, Solano C, Sonnabend R, Song JW, Sun Q, Sun ZT, Tacconi M, Tang XW, Tang ZC, Tian J, Ting SCC, Ting SM, Tomassetti N, Torsti J, Tüysüz C, Urban T, Usoskin I, Vagelli V, Vainio R, Valente E, Valtonen E, Vázquez Acosta M, Vecchi M, Velasco M, Vialle JP, Wallmann C, Wang LQ, Wang NH, Wang QL, Wang S, Wang X, Wang ZX, Wei J, Weng ZL, Wu H, Xiong RQ, Xu W, Yan Q, Yang Y, Yi H, Yu YJ, Yu ZQ, Zannoni M, Zhang C, Zhang F, Zhang FZ, Zhang JH, Zhang Z, Zhao F, Zheng ZM, Zhuang HL, Zhukov V, Zichichi A, Zimmermann N, Zuccon P. Properties of Neon, Magnesium, and Silicon Primary Cosmic Rays Results from the Alpha Magnetic Spectrometer. PHYSICAL REVIEW LETTERS 2020; 124:211102. [PMID: 32530660 DOI: 10.1103/physrevlett.124.211102] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 04/20/2020] [Indexed: 06/11/2023]
Abstract
We report the observation of new properties of primary cosmic rays, neon (Ne), magnesium (Mg), and silicon (Si), measured in the rigidity range 2.15 GV to 3.0 TV with 1.8×10^{6} Ne, 2.2×10^{6} Mg, and 1.6×10^{6} Si nuclei collected by the Alpha Magnetic Spectrometer experiment on the International Space Station. The Ne and Mg spectra have identical rigidity dependence above 3.65 GV. The three spectra have identical rigidity dependence above 86.5 GV, deviate from a single power law above 200 GV, and harden in an identical way. Unexpectedly, above 86.5 GV the rigidity dependence of primary cosmic rays Ne, Mg, and Si spectra is different from the rigidity dependence of primary cosmic rays He, C, and O. This shows that the Ne, Mg, and Si and He, C, and O are two different classes of primary cosmic rays.
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Pu HC, Lin CH, Lai YC, Shih MH, Chang LC, Lee HF, Lee PT, Hong GT, Li YH, Chang WY, Lo CH. Active Volcanism Revealed from a Seismicity Conduit in the Long-resting Tatun Volcano Group of Northern Taiwan. Sci Rep 2020; 10:6153. [PMID: 32273552 PMCID: PMC7145833 DOI: 10.1038/s41598-020-63270-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 03/25/2020] [Indexed: 11/16/2022] Open
Abstract
Abundant earthquakes clustered within a particular zone often reflect an active geological feature, such as clustering seismicity along a fault zone and a huge number of volcanic-earthquakes around the erupting conduit. Herein we perform a double-difference tomographic inversion and relocate the seismicity at the long-resting Tatun volcano group (TVG) in northern Taiwan. A dramatic improvement of the earthquake location model surprisingly show that, from 2014 to 2017, two clustered seismic zones are identified in the TVG. One major group of events (>1000) persistently clustered within a ~500 m diameter vertical conduit with a ~2 km height. The clustering seismicity conduit is just located nearby Dayoukeng, one of the strongest fumaroles in the TVG, and is connected to a fracture zone characterized by low Vp/Vs in the shallow crust. The other group of events is clustered within a sphere-like zone beneath Mt. Chihsin around the depths between 0.5 km and 2 km. Both seismic zones are probably triggered by the significantly volcanic gases and fluids ascending from the deep magma reservoir. Combined with a variety of results from literature, the seismicity conduit near the strong fumarole is the evidence for an active volcano and also identifies a likely pathway for ascending magma if the TVG erupts again in the future. But possibility of developing different magma pathways at other clustered seismic zones such as beneath Mt. Chihsin may not be totally excluded.
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Aguilar M, Ali Cavasonza L, Ambrosi G, Arruda L, Attig N, Bachlechner A, Barao F, Barrau A, Barrin L, Bartoloni A, Başeğmez-du Pree S, Battiston R, Becker U, Behlmann M, Beischer B, Berdugo J, Bertucci B, Bindi V, de Boer W, Bollweg K, Borgia B, Boschini MJ, Bourquin M, Bueno EF, Burger J, Burger WJ, Cai XD, Capell M, Caroff S, Casaus J, Castellini G, Cervelli F, Chang YH, Chen GM, Chen HS, Chen Y, Cheng L, Chou HY, Choutko V, Chung CH, Clark C, Coignet G, Consolandi C, Contin A, Corti C, Cui Z, Dadzie K, Dai YM, Datta A, Delgado C, Della Torre S, Demirköz MB, Derome L, Di Falco S, Di Felice V, Díaz C, Dimiccoli F, von Doetinchem P, Dong F, Donnini F, Duranti M, Egorov A, Eline A, Feng J, Fiandrini E, Fisher P, Formato V, Galaktionov Y, Gámez C, García-López RJ, Gargiulo C, Gast H, Gebauer I, Gervasi M, Giovacchini F, Gómez-Coral DM, Gong J, Goy C, Grabski V, Grandi D, Graziani M, Guo KH, Haino S, Han KC, He ZH, Hsieh TH, Huang H, Huang ZC, Incagli M, Jang WY, Jia Y, Jinchi H, Kanishev K, Khiali B, Kim GN, Kirn T, Konyushikhin M, Kounina O, Kounine A, Koutsenko V, Kulemzin A, La Vacca G, Laudi E, Laurenti G, Lazzizzera I, Lebedev A, Lee HT, Lee SC, Li JQ, Li Q, Li TX, Li ZH, Light C, Lin CH, Lippert T, Liu Z, Lu SQ, Lu YS, Luebelsmeyer K, Luo F, Luo JZ, Luo X, Lyu SS, Machate F, Mañá C, Marín J, Martin T, Martínez G, Masi N, Maurin D, Menchaca-Rocha A, Meng Q, Mo DC, Molero M, Mott P, Mussolin L, Nelson T, Ni JQ, Nikonov N, Nozzoli F, Oliva A, Orcinha M, Palermo M, Palmonari F, Paniccia M, Pashnin A, Pauluzzi M, Pensotti S, Phan HD, Plyaskin V, Poireau V, Poluianov S, Popkow A, Qi XM, Qin X, Qu ZY, Quadrani L, Rancoita PG, Rapin D, Reina Conde A, Rosier-Lees S, Rozhkov A, Rozza D, Sagdeev R, Schael S, Schmidt SM, Schulz von Dratzig A, Schwering G, Seo ES, Shan BS, Shi JY, Siedenburg T, Solano C, Song JW, Sun ZT, Tacconi M, Tang XW, Tang ZC, Tian J, Ting SCC, Ting SM, Tomassetti N, Torsti J, Tüysüz C, Urban T, Usoskin I, Vagelli V, Vainio R, Valente E, Valtonen E, Vázquez Acosta M, Vecchi M, Velasco M, Vialle JP, Wang LQ, Wang NH, Wang QL, Wang X, Wang XQ, Wang ZX, Wei J, Weng ZL, Wu H, Xiong RQ, Xu W, Yan Q, Yang Y, Yi H, Yu YJ, Yu ZQ, Zannoni M, Zeissler S, Zhang C, Zhang F, Zhang JH, Zhang Z, Zhao F, Zheng ZM, Zhuang HL, Zhukov V, Zichichi A, Zimmermann N, Zuccon P. Properties of Cosmic Helium Isotopes Measured by the Alpha Magnetic Spectrometer. PHYSICAL REVIEW LETTERS 2019; 123:181102. [PMID: 31763896 DOI: 10.1103/physrevlett.123.181102] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 10/02/2019] [Indexed: 06/10/2023]
Abstract
Precision measurements by the Alpha Magnetic Spectrometer (AMS) on the International Space Station of ^{3}He and ^{4}He fluxes are presented. The measurements are based on 100 million ^{4}He nuclei in the rigidity range from 2.1 to 21 GV and 18 million ^{3}He from 1.9 to 15 GV collected from May 2011 to November 2017. We observed that the ^{3}He and ^{4}He fluxes exhibit nearly identical variations with time. The relative magnitude of the variations decreases with increasing rigidity. The rigidity dependence of the ^{3}He/^{4}He flux ratio is measured for the first time. Below 4 GV, the ^{3}He/^{4}He flux ratio was found to have a significant long-term time dependence. Above 4 GV, the ^{3}He/^{4}He flux ratio was found to be time independent, and its rigidity dependence is well described by a single power law ∝R^{Δ} with Δ=-0.294±0.004. Unexpectedly, this value is in agreement with the B/O and B/C spectral indices at high energies.
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Hsieh YC, Liao YC, Li CH, Lin JC, Weng CJ, Lin CC, Lo CP, Huang KC, Huang JL, Lin CH, Wu TJ, Sheu WH. P5644Hypoglycemic episodes increase the risk of ventricular arrhythmias and sudden cardiac arrest in patients with type 2 diabetes - a nationwide cohort study. Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz746.0587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Background
Hypoglycemic episode (HE) increases the risk of cardiovascular mortality. The impact of HE on the risk of sudden death remains unclear. We hypothesized that HE increases the risks of ventricular arrhythmia (VA) and sudden cardiac arrest (SCA), and that anti-diabetic agents (ADAs) causing hypoglycemia also increase the risks of VA and SCA.
Methods
Patients aged ≥20 years with newly diagnosed diabetes were identified from the Taiwan National Insurance Database. HE was defined as the presentation of hypoglycemic coma or specified/unspecified hypoglycemia. For control group, we included diabetic patients without HE, and they were frequency-matched to the HE group at a 4:1 ratio. The primary outcome was the occurrence of any event of VA (including ventricular tachycardia and fibrillation) and SCA during the defined follow-up periods. Multivariate Cox hazards regression model was used to evaluate the hazard ratio (HR) for VA or SCA.
Results
A total of 54,303 diabetic patients were screened with 1,037 of them in the HE group, and 4,148 in the control group. During a mean follow-up period of 3.3±2.5 years, 29 VA/SCA events had occurred. Compared to the control group, the HE group had a higher incidence of VA/SCA (adjusted HR: 2.42, p=0.04). Diabetic patients medicated with insulin for glycemic control increased the risk of VA/SCA compared to those without insulin (adjusted HR: 3.05, p=0.01).
Kaplan-Meier survival curves
Conclusions
HEs in patients with diabetes increased the risks of VA and SCA compared to those without. Their use of insulin also independently increased the risk of VA/SCA.
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Wang CF, Wang WN, Lin CH, Lee KJ, Hu CC, Lai JY. Facile Fabrication of Durable Superhydrophobic Films from Carbon Nanotube/Main-Chain Type Polybenzoxazine Composites. Polymers (Basel) 2019; 11:E1183. [PMID: 31337137 PMCID: PMC6680462 DOI: 10.3390/polym11071183] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 07/10/2019] [Accepted: 07/13/2019] [Indexed: 11/17/2022] Open
Abstract
Superhydrophobic materials have immense applications in the fields of industry and research. However, their durability is still a cause for concern. A facile method for preparing durable superhydrophobic films from carbon nanotubes (CNTs) and the main-chain type polybenzoxazine precursors is reported herein. We used probe ultrasonicator to prepare CNT/polybenzoxazine coatings. Compared with the general sonicating dispersion process, the dispersion time was greatly reduced from a few hours to 5 minutes and the prepared suspension exhibited film-forming characteristics well. The CNT/polybenzoxazine films, which do not contain any fluorinated compounds, exhibit remarkable durability against thermal treatment, organic solvents, corrosive liquids, and sandpaper abrasion, while retaining their superhydrophobicity. Furthermore, these CNT/polybenzoxazine films also showed durable superhydrophobicity after ultraviolet (UV) irradiation for 100 h. This CNT/polybenzoxazine film can be readily used for practical applications to make durable superhydrophobic coatings.
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Chien CT, Chen YC, Liu YC, Liang SH, Lin HH, Lin CH. The antimicrobial photodynamic inactivation resistance of Candida albicans is modulated by the Hog1 pathway and the Cap1 transcription factor. Med Mycol 2019; 57:618-627. [PMID: 30289464 DOI: 10.1093/mmy/myy079] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 08/02/2018] [Accepted: 09/23/2018] [Indexed: 12/22/2022] Open
Abstract
Candida albicans is the most important fungal pathogen afflicting humans, particularly immunocompromised patients. However, currently available antifungal drugs are limited and ineffective against drug-resistant strains. The development of new drugs or alternative therapeutic approaches to control fungal infections is urgent and necessary. Photodynamic inactivation (PDI) is a new promising therapy for eradicating microorganism infections through combining visible light, photosensitizers, and oxygen to generate reactive oxygen species (ROS). Although cytoprotective responses induced by photodynamic therapy (PDT) have been well studied in cancer cells, the mechanisms by which C. albicans responds to PDI are largely unknown. In this study, we first demonstrated that PDI induces C. albicans Hog1p activation. Deletion of any of the SSK2, PBS2, and HOG1 genes significantly decreased the survival rate after photochemical reactions, indicating that the Hog1 SAPK pathway is required for tolerance to PDI. Furthermore, the basic leucine zipper transcription factor Cap1 that regulates several downstream antioxidant genes was highly expressed during the response to PDI, and loss of CAP1 also resulted in decreased C. albicans survival rates. This study demonstrates the importance of the Hog1 SAPK and the Cap1 transcription factor, which regulates in resistance to PDI-mediated oxidative stress in C. albicans. Understanding the mechanisms by which C. albicans responds to PDI and consequently scavenges ROS will be very useful for the further development of therapeutics to control fungal infectious diseases, particularly those of the skin and mucosal infections.
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Liu TJ, Chen CH, Wu PY, Lin CH, Chen CM. Efficient and Adhesiveless Metallization of Flexible Polyimide by Functional Grafting of Carboxylic Acid Groups. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:7212-7221. [PMID: 31083950 DOI: 10.1021/acs.langmuir.9b00354] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Surface metallization of polyimide (PI) is the key process for the preparation of flexible printed circuit boards (FPCBs). To meet the miniaturization demand, the ultrathinness of FPCB by the removal of the intermediate adhesive layer is imperative. The common adhesiveless process relies on the surface activation of hydrophobic PI through alkaline hydrolysis to generate the hydrophilic carboxylate anion sites for the metallic deposition. However, the alkaline hydrolysis process involves the imide ring cleavage caused by the attack of a strong nucleophile (OH-), resulting in mechanical destruction and surface coarseness of PI. In this study, a new PI is synthesized with the grafting of carboxylic acid groups as the active sites to intrinsically activate PI for efficient metallization. The surface activation is accomplished through an acid-base neutralization reaction in a dilute alkaline environment, which can suppress the alkaline hydrolysis reaction. The attenuated total reflection Fourier transform infrared spectroscopy analysis confirms a significant reduction of the extent of the imide ring cleavage in the carboxylic acid-grafted PI films. According to the microstructural examination using transmission electron microscopy, the deposited metal film adheres firmly to the carboxylic acid-grafted PI films through an interlocking effect of a broccoli bud-shaped nanocluster layer.
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Chen C, Yu TY, Wu JH, Ariraman M, Juang TY, Abu-Omar MM, Lin CH. Synthesis and Properties of Quinoxaline-Containing Benzoxazines and Polybenzoxazines. ACS OMEGA 2019; 4:9092-9101. [PMID: 31459997 PMCID: PMC6648507 DOI: 10.1021/acsomega.9b01042] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 05/07/2019] [Indexed: 06/10/2023]
Abstract
The object of this work is to prepare quinoxaline-based benzoxazines and evaluate thermal properties of their thermosets. For this object, 4,4'-(quinoxaline-2,3-diyl)diphenol (QDP)/furfurylamine-based benzoxazine (QDP-fu) and 4,4',4″,4‴-([6,6'-biquinoxaline]-2,2',3,3'-tetrayl)tetraphenol (BQTP)/furfurylamine-based benzoxazine (BQTP-fu) were prepared. The structures of QDP-fu and BQTP-fu were successfully confirmed by FTIR and 1H and 13C NMR spectra. We studied the curing behavior of QDP-fu and BQTP-fu and thermal properties of their thermosets. According to DSC thermograms, QDP-fu and BQTP-fu have the attractive onset exothermic temperatures of 181 and 186 °C, respectively. The onset temperature is approximately 45 °C lower than that of a bisphenol A/furfurylamine-based benzoxazines. According to DMA TMA and TGA thermograms, the thermoset of BQTP-fu shows impressive thermal properties, with a T g value of 418 °C, a coefficient of thermal expansion of 39 ppm/°C, a 5% decomposition temperature of 430 °C, and a char yield of 72%.
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Shih PY, Liao YT, Tseng YK, Deng FS, Lin CH. A Potential Antifungal Effect of Chitosan Against Candida albicans Is Mediated via the Inhibition of SAGA Complex Component Expression and the Subsequent Alteration of Cell Surface Integrity. Front Microbiol 2019; 10:602. [PMID: 30972050 PMCID: PMC6443709 DOI: 10.3389/fmicb.2019.00602] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 03/11/2019] [Indexed: 12/21/2022] Open
Abstract
Due to the high incidence of nosocomial Candida albicans infection, the first-line drugs for C. albicans infection have been heavily used, and the emergence of drug-resistant strains has gradually increased. Thus, a new antifungal drug or therapeutic method is needed. Chitosan, a product of chitin deacetylation, is considered to be potentially therapeutic for fungal infections because of its excellent biocompatibility, biodegradability and low toxicity. The biocidal action of chitosan against C. albicans shows great commercial potential, but the exact mechanisms underlying its antimicrobial activity are unclear. To reveal these mechanisms, mutant library screening was performed. ADA2 gene, which encodes a histone acetylation coactivator in the SAGA complex, was identified. Transmission electronic microscopy images showed that the surface of chitosan-treated ada2Δ cells was substantially disrupted and displayed an irregular morphology. Interestingly, the cell wall of ada2Δ cells was significantly thinner than that of wild-type cells, with a thickness similar to that seen in the chitosan-treated wild-type strain. Although ADA2 is required for chitosan tolerance, expression of ADA2 and several Ada2-mediated cell wall-related genes (ALS2, PGA45, and ACE2) and efflux transporter genes (MDR1 and CDR1) were significantly inhibited by chitosan. Furthermore, GCN5 encoding a SAGA complex catalytic subunit was inhibited by chitosan, and gcn5Δ cells exhibited phenotypes comparable to those of ada2Δ cells in response to chitosan and other cell surface-disrupting agents. This study demonstrated that a potential antifungal mechanism of chitosan against C. albicans operates by inhibiting SAGA complex gene expression, which decreases the protection of the cell surface against chitosan.
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Aguilar M, Ali Cavasonza L, Alpat B, Ambrosi G, Arruda L, Attig N, Azzarello P, Bachlechner A, Barao F, Barrau A, Barrin L, Bartoloni A, Basara L, Başeğmez-du Pree S, Battiston R, Becker U, Behlmann M, Beischer B, Berdugo J, Bertucci B, Bindi V, de Boer W, Bollweg K, Borgia B, Boschini MJ, Bourquin M, Bueno EF, Burger J, Burger WJ, Cai XD, Capell M, Caroff S, Casaus J, Castellini G, Cervelli F, Chang YH, Chen GM, Chen HS, Chen Y, Cheng L, Chou HY, Choutko V, Chung CH, Clark C, Coignet G, Consolandi C, Contin A, Corti C, Crispoltoni M, Cui Z, Dadzie K, Dai YM, Datta A, Delgado C, Della Torre S, Demirköz MB, Derome L, Di Falco S, Di Felice V, Dimiccoli F, Díaz C, von Doetinchem P, Dong F, Donnini F, Duranti M, Egorov A, Eline A, Eronen T, Feng J, Fiandrini E, Fisher P, Formato V, Galaktionov Y, García-López RJ, Gargiulo C, Gast H, Gebauer I, Gervasi M, Giovacchini F, Gómez-Coral DM, Gong J, Goy C, Grabski V, Grandi D, Graziani M, Guo KH, Haino S, Han KC, He ZH, Heil M, Hsieh TH, Huang H, Huang ZC, Incagli M, Jia Y, Jinchi H, Kanishev K, Khiali B, Kirn T, Konak C, Kounina O, Kounine A, Koutsenko V, Kulemzin A, La Vacca G, Laudi E, Laurenti G, Lazzizzera I, Lebedev A, Lee HT, Lee SC, Leluc C, Li JQ, Li Q, Li TX, Li ZH, Light C, Lin CH, Lippert T, Liu FZ, Liu H, Liu Z, Lu SQ, Lu YS, Luebelsmeyer K, Luo F, Luo JZ, Luo X, Lyu SS, Machate F, Mañá C, Marín J, Martin T, Martínez G, Masi N, Maurin D, Menchaca-Rocha A, Meng Q, Mo DC, Molero M, Mott P, Mussolin L, Nelson T, Ni JQ, Nikonov N, Nozzoli F, Oliva A, Orcinha M, Palermo M, Palmonari F, Paniccia M, Pashnin A, Pauluzzi M, Pensotti S, Perrina C, Phan HD, Picot-Clemente N, Plyaskin V, Pohl M, Poireau V, Popkow A, Quadrani L, Qi XM, Qin X, Qu ZY, Rancoita PG, Rapin D, Conde AR, Rosier-Lees S, Rozhkov A, Rozza D, Sagdeev R, Solano C, Schael S, Schmidt SM, von Dratzig AS, Schwering G, Seo ES, Shan BS, Shi JY, Siedenburg T, Song JW, Sun ZT, Tacconi M, Tang XW, Tang ZC, Tian J, Ting SCC, Ting SM, Tomassetti N, Torsti J, Urban T, Vagelli V, Valente E, Valtonen E, Acosta MV, Vecchi M, Velasco M, Vialle JP, Vizán J, Wang LQ, Wang NH, Wang QL, Wang X, Wang XQ, Wang ZX, Wei J, Weng ZL, Wu H, Xiong RQ, Xu W, Yan Q, Yang Y, Yi H, Yu YJ, Yu ZQ, Zannoni M, Zeissler S, Zhang C, Zhang F, Zhang JH, Zhang Z, Zhao F, Zheng ZM, Zhuang HL, Zhukov V, Zichichi A, Zimmermann N, Zuccon P. Towards Understanding the Origin of Cosmic-Ray Electrons. PHYSICAL REVIEW LETTERS 2019; 122:101101. [PMID: 30932626 DOI: 10.1103/physrevlett.122.101101] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Indexed: 06/09/2023]
Abstract
Precision results on cosmic-ray electrons are presented in the energy range from 0.5 GeV to 1.4 TeV based on 28.1×10^{6} electrons collected by the Alpha Magnetic Spectrometer on the International Space Station. In the entire energy range the electron and positron spectra have distinctly different magnitudes and energy dependences. The electron flux exhibits a significant excess starting from 42.1_{-5.2}^{+5.4} GeV compared to the lower energy trends, but the nature of this excess is different from the positron flux excess above 25.2±1.8 GeV. Contrary to the positron flux, which has an exponential energy cutoff of 810_{-180}^{+310} GeV, at the 5σ level the electron flux does not have an energy cutoff below 1.9 TeV. In the entire energy range the electron flux is well described by the sum of two power law components. The different behavior of the cosmic-ray electrons and positrons measured by the Alpha Magnetic Spectrometer is clear evidence that most high energy electrons originate from different sources than high energy positrons.
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Aguilar M, Ali Cavasonza L, Ambrosi G, Arruda L, Attig N, Azzarello P, Bachlechner A, Barao F, Barrau A, Barrin L, Bartoloni A, Basara L, Başeğmez-du Pree S, Battiston R, Becker U, Behlmann M, Beischer B, Berdugo J, Bertucci B, Bindi V, de Boer W, Bollweg K, Borgia B, Boschini MJ, Bourquin M, Bueno EF, Burger J, Burger WJ, Cai XD, Capell M, Caroff S, Casaus J, Castellini G, Cervelli F, Chang YH, Chen GM, Chen HS, Chen Y, Cheng L, Chou HY, Choutko V, Chung CH, Clark C, Coignet G, Consolandi C, Contin A, Corti C, Crispoltoni M, Cui Z, Dadzie K, Dai YM, Datta A, Delgado C, Della Torre S, Demirköz MB, Derome L, Di Falco S, Dimiccoli F, Díaz C, von Doetinchem P, Dong F, Donnini F, Duranti M, Egorov A, Eline A, Eronen T, Feng J, Fiandrini E, Fisher P, Formato V, Galaktionov Y, García-López RJ, Gargiulo C, Gast H, Gebauer I, Gervasi M, Giovacchini F, Gómez-Coral DM, Gong J, Goy C, Grabski V, Grandi D, Graziani M, Guo KH, Haino S, Han KC, He ZH, Heil M, Hsieh TH, Huang H, Huang ZC, Incagli M, Jia Y, Jinchi H, Kanishev K, Khiali B, Kirn T, Konak C, Kounina O, Kounine A, Koutsenko V, Kulemzin A, La Vacca G, Laudi E, Laurenti G, Lazzizzera I, Lebedev A, Lee HT, Lee SC, Leluc C, Li JQ, Li Q, Li TX, Li ZH, Light C, Lin CH, Lippert T, Liu FZ, Liu H, Liu Z, Lu SQ, Lu YS, Luebelsmeyer K, Luo F, Luo JZ, Luo X, Lyu SS, Machate F, Mañá C, Marín J, Martin T, Martínez G, Masi N, Maurin D, Menchaca-Rocha A, Meng Q, Mo DC, Molero M, Mott P, Mussolin L, Nelson T, Ni JQ, Nikonov N, Nozzoli F, Oliva A, Orcinha M, Palermo M, Palmonari F, Paniccia M, Pashnin A, Pauluzzi M, Pensotti S, Perrina C, Phan HD, Picot-Clemente N, Plyaskin V, Pohl M, Poireau V, Popkow A, Quadrani L, Qi XM, Qin X, Qu ZY, Rancoita PG, Rapin D, Conde AR, Rosier-Lees S, Rozhkov A, Rozza D, Sagdeev R, Solano C, Schael S, Schmidt SM, Schulz von Dratzig A, Schwering G, Seo ES, Shan BS, Shi JY, Siedenburg T, Song JW, Sun ZT, Tacconi M, Tang XW, Tang ZC, Tian J, Ting SCC, Ting SM, Tomassetti N, Torsti J, Urban T, Vagelli V, Valente E, Valtonen E, Vázquez Acosta M, Vecchi M, Velasco M, Vialle JP, Vizán J, Wang LQ, Wang NH, Wang QL, Wang X, Wang XQ, Wang ZX, Wei J, Weng ZL, Wu H, Xiong RQ, Xu W, Yan Q, Yang Y, Yi H, Yu YJ, Yu ZQ, Zannoni M, Zeissler S, Zhang C, Zhang F, Zhang JH, Zhang Z, Zhao F, Zheng ZM, Zhuang HL, Zhukov V, Zichichi A, Zimmermann N, Zuccon P. Towards Understanding the Origin of Cosmic-Ray Positrons. PHYSICAL REVIEW LETTERS 2019; 122:041102. [PMID: 30768313 DOI: 10.1103/physrevlett.122.041102] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2018] [Revised: 12/04/2018] [Indexed: 06/09/2023]
Abstract
Precision measurements of cosmic ray positrons are presented up to 1 TeV based on 1.9 million positrons collected by the Alpha Magnetic Spectrometer on the International Space Station. The positron flux exhibits complex energy dependence. Its distinctive properties are (a) a significant excess starting from 25.2±1.8 GeV compared to the lower-energy, power-law trend, (b) a sharp dropoff above 284_{-64}^{+91} GeV, (c) in the entire energy range the positron flux is well described by the sum of a term associated with the positrons produced in the collision of cosmic rays, which dominates at low energies, and a new source term of positrons, which dominates at high energies, and (d) a finite energy cutoff of the source term of E_{s}=810_{-180}^{+310} GeV is established with a significance of more than 4σ. These experimental data on cosmic ray positrons show that, at high energies, they predominantly originate either from dark matter annihilation or from other astrophysical sources.
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Chen CH, Lin CM, Juang TY, Abu-Omar MM, Lin CH. The reaction of activated esters with epoxides for self-curable, highly flexible, A2B2- and A3B3-type epoxy compounds. Polym Chem 2019. [DOI: 10.1039/c9py00377k] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
To achieve high-Tg and low-dissipation epoxy thermosets, bis(2-methoxy-4-(oxiran-2-ylmethyl)phenyl)isophthalate (2) and tris(2-methoxy-4-(oxiran-2-ylmethyl)phenyl)benzene-1,3,5-tricarboxylate (3) were prepared.
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Deng FS, Lin CH. Cpp1 phosphatase mediated signaling crosstalk between Hog1 and Cek1 mitogen-activated protein kinases is involved in the phenotypic transition in Candida albicans. Med Mycol 2018; 56:242-252. [PMID: 28431022 DOI: 10.1093/mmy/myx027] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 03/23/2017] [Indexed: 12/29/2022] Open
Abstract
Cellular signaling pathways involved in cell growth and differentiation mediated by mitogen-activated protein kinase (MAPK) cascades have been well characterized in fungi. However, the mechanisms of signaling crosstalk between MAPKs to ensure signaling specificity are largely unknown. Previous work showed that activation of the Candida albicans Cek1 MAPK pathway resulted in opaque cell formation and filamentation, which mirrored the phenotypes to hog1Δ. Additionally, deleting the HOG1 gene stimulated Cek1p. Thus, we hypothesized that an unknown factor could act as a bridge between these two MAPKs. In Saccharomyces cerevisiae, the dual-specificity phosphatase (DSP) Msg5 specifically dephosphorylates Fus3p/Kss1p. C. albicans Cpp1, an ortholog of Msg5, has been shown to be important in regulating Cek1p. Compared with the wild-type strain, hog1Δ shows a ∼40% reduction in CPP1 expression. Consistent with previous reports, CPP1 deletion also resulted in Cek1 hyperphosphorylation, implicating Cpp1 as a regulator of the Hog1 and Cek1 cascades. Interestingly, both cpp1Δ and hog1Δ induced 100% opaque colony formation in MTL-homozygous strains grown on N-acetylglucosamine (NAG) plates, whereas the wild-type and complemented strains exhibited 80.9% and 77.1% white-to-opaque switching rates, respectively. CPP1 gene deletion also caused hyperfilamentous phenotypes in both white and opaque cells. These phenomena may be due to highly phosphorylated Cek1p, as deleting CEK1 in the cpp1Δ background generated nonfilamentous strains and reduced opaque colony formation. Taken together, we conclude that cpp1Δ and hog1Δ exhibited comparable phenotypes, and both are involved in regulating Cek1 phosphorylation, implicating Cpp1 phosphatase as a key intermediary between the Hog1 and Cek1 signal transduction pathways.
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Deng FS, Lin CH. Identification and characterization of ORF19.1725, a novel gene contributing to the white cell pheromone response and virulence-associated functions in Candida albicans. Virulence 2018; 9:866-878. [PMID: 29726301 PMCID: PMC5955465 DOI: 10.1080/21505594.2018.1456228] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
An epigenetic transition between white cells and opaque cells influences several properties of Candida albicans biology, including cellular morphology, biofilm formation, virulence, and sexual mating. In particular, these two cell types exhibit marked differences in their ability to undergo sex. A previous study identified the transcriptional regulator of pheromone response in both the white and opaque states as Cph1 because deletion of this gene abolished both pheromone-induced cell adhesion in white cells and sexual mating in opaque cells. To further explore how these cell types exhibit distinct biological outputs upon pheromone stimulation, we selected five Cph1-regulated genes with significant expression during the pheromone response in the white state but not the opaque state. These phase-specific pheromone-induced genes are ORF19.1539, ORF19.1725, ORF19.2430, ORF19.2691 and ORF19.5557. Deletion of each gene revealed that orf19.1539Δ, orf19.1725Δ, orf19.2430Δ and orf19.5557Δ showed significant decreases in pheromone-stimulated cell adhesion in the white state but retained normal mating competency in the opaque state, indicating that a particular role in white cell pheromone response is mediated by these four genes. Interestingly, the defects of orf19.1725Δ in pheromone-stimulated cell adhesion also abolished conventional biofilms and hyphal growth. Zebrafish egg infection assays further demonstrated that ORF19.1725 is involved in cell adhesion, penetration and virulence. Overall, four Cph1-regulated downstream targets were identified in the regulation of white cell pheromone response. We also clarified the roles of C. albicans ORF19.1725 in cell adhesion, hyphal growth, biofilm formation and virulence.
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Chen CH, Lin CH, Hon JM, Wang MW, Juang TY. First halogen and phosphorus-free, flame-retardant benzoxazine thermosets derived from main-chain type bishydroxydeoxybenzoin-based benzoxazine polymers. POLYMER 2018. [DOI: 10.1016/j.polymer.2018.08.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Lin CH, Chien HF, Lin MH, Chen CP, Shen M, Chen CT. Chitosan Inhibits the Rehabilitation of Damaged Microbes Induced by Photodynamic Inactivation. Int J Mol Sci 2018; 19:ijms19092598. [PMID: 30200473 PMCID: PMC6164787 DOI: 10.3390/ijms19092598] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 08/26/2018] [Accepted: 08/31/2018] [Indexed: 12/24/2022] Open
Abstract
Previously, we showed that chitosan could augment the biocidal efficacy mediated by photodynamic treatment against Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. In this study, we showed that the antimicrobial action of chitosan in augmenting photodynamic inactivation (PDI) is related to the increase in cell surface destruction. The microbial cell surfaces exhibit severe irregular shapes after PDI in the presence of chitosan as demonstrated by transmitted electron microscopy. Furthermore, increases in the concentration or incubation time of chitosan significantly reduced the amounts of photosensitizer toluidine blue O required, indicating that chitosan could be an augmenting agent used in conjunction with PDI against S. aureus, P. aeruginosa, and C. albicans. A prolonged lag phase was found in microbial cells that survived to PDI, in which chitosan acted to completely eradicate the cells. Once the exponential log stage and cell rebuild began, their cellular functions from PDI-induced damage returned and the increased cytotoxic effect of chitosan disappeared. Together, our results suggest that chitosan can prevent the rehabilitation of PDI-surviving microbial cells, leading to increased biocidal efficacy.
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Aguilar M, Cavasonza LA, Ambrosi G, Arruda L, Attig N, Aupetit S, Azzarello P, Bachlechner A, Barao F, Barrau A, Barrin L, Bartoloni A, Basara L, Başeğmez-du Pree S, Battarbee M, Battiston R, Becker U, Behlmann M, Beischer B, Berdugo J, Bertucci B, Bindel KF, Bindi V, de Boer W, Bollweg K, Bonnivard V, Borgia B, Boschini MJ, Bourquin M, Bueno EF, Burger J, Cadoux F, Cai XD, Capell M, Caroff S, Casaus J, Castellini G, Cervelli F, Chae MJ, Chang YH, Chen AI, Chen GM, Chen HS, Chen Y, Cheng L, Chou HY, Choumilov E, Choutko V, Chung CH, Clark C, Clavero R, Coignet G, Consolandi C, Contin A, Corti C, Creus W, Crispoltoni M, Cui Z, Dadzie K, Dai YM, Datta A, Delgado C, Della Torre S, Demirköz MB, Derome L, Di Falco S, Dimiccoli F, Díaz C, von Doetinchem P, Dong F, Donnini F, Duranti M, D'Urso D, Egorov A, Eline A, Eronen T, Feng J, Fiandrini E, Fisher P, Formato V, Galaktionov Y, Gallucci G, García-López RJ, Gargiulo C, Gast H, Gebauer I, Gervasi M, Ghelfi A, Giovacchini F, Gómez-Coral DM, Gong J, Goy C, Grabski V, Grandi D, Graziani M, Guo KH, Haino S, Han KC, He ZH, Heil M, Hsieh TH, Huang H, Huang ZC, Huh C, Incagli M, Ionica M, Jang WY, Jia Y, Jinchi H, Kang SC, Kanishev K, Khiali B, Kim GN, Kim KS, Kirn T, Konak C, Kounina O, Kounine A, Koutsenko V, Kulemzin A, La Vacca G, Laudi E, Laurenti G, Lazzizzera I, Lebedev A, Lee HT, Lee SC, Leluc C, Li HS, Li JQ, Li Q, Li TX, Li ZH, Li ZY, Lim S, Lin CH, Lipari P, Lippert T, Liu D, Liu H, Lordello VD, Lu SQ, Lu YS, Luebelsmeyer K, Luo F, Luo JZ, Lyu SS, Machate F, Mañá C, Marín J, Martin T, Martínez G, Masi N, Maurin D, Menchaca-Rocha A, Meng Q, Mikuni VM, Mo DC, Mott P, Nelson T, Ni JQ, Nikonov N, Nozzoli F, Oliva A, Orcinha M, Palermo M, Palmonari F, Palomares C, Paniccia M, Pauluzzi M, Pensotti S, Perrina C, Phan HD, Picot-Clemente N, Pilo F, Pizzolotto C, Plyaskin V, Pohl M, Poireau V, Quadrani L, Qi XM, Qin X, Qu ZY, Räihä T, Rancoita PG, Rapin D, Ricol JS, Rosier-Lees S, Rozhkov A, Rozza D, Sagdeev R, Schael S, Schmidt SM, von Dratzig AS, Schwering G, Seo ES, Shan BS, Shi JY, Siedenburg T, Son D, Song JW, Tacconi M, Tang XW, Tang ZC, Tescaro D, Ting SCC, Ting SM, Tomassetti N, Torsti J, Türkoğlu C, Urban T, Vagelli V, Valente E, Valtonen E, Vázquez Acosta M, Vecchi M, Velasco M, Vialle JP, Wang LQ, Wang NH, Wang QL, Wang X, Wang XQ, Wang ZX, Wei CC, Weng ZL, Whitman K, Wu H, Wu X, Xiong RQ, Xu W, Yan Q, Yang J, Yang M, Yang Y, Yi H, Yu YJ, Yu ZQ, Zannoni M, Zeissler S, Zhang C, Zhang F, Zhang J, Zhang JH, Zhang SW, Zhang Z, Zheng ZM, Zhuang HL, Zhukov V, Zichichi A, Zimmermann N, Zuccon P. Observation of Complex Time Structures in the Cosmic-Ray Electron and Positron Fluxes with the Alpha Magnetic Spectrometer on the International Space Station. PHYSICAL REVIEW LETTERS 2018; 121:051102. [PMID: 30118287 DOI: 10.1103/physrevlett.121.051102] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 05/11/2018] [Indexed: 06/08/2023]
Abstract
We present high-statistics, precision measurements of the detailed time and energy dependence of the primary cosmic-ray electron flux and positron flux over 79 Bartels rotations from May 2011 to May 2017 in the energy range from 1 to 50 GeV. For the first time, the charge-sign dependent modulation during solar maximum has been investigated in detail by leptons alone. Based on 23.5×10^{6} events, we report the observation of short-term structures on the timescale of months coincident in both the electron flux and the positron flux. These structures are not visible in the e^{+}/e^{-} flux ratio. The precision measurements across the solar polarity reversal show that the ratio exhibits a smooth transition over 830±30 days from one value to another. The midpoint of the transition shows an energy dependent delay relative to the reversal and changes by 260±30 days from 1 to 6 GeV.
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Aguilar M, Ali Cavasonza L, Alpat B, Ambrosi G, Arruda L, Attig N, Aupetit S, Azzarello P, Bachlechner A, Barao F, Barrau A, Barrin L, Bartoloni A, Basara L, Başeğmez-du Pree S, Battarbee M, Battiston R, Becker U, Behlmann M, Beischer B, Berdugo J, Bertucci B, Bindel KF, Bindi V, de Boer W, Bollweg K, Bonnivard V, Borgia B, Boschini MJ, Bourquin M, Bueno EF, Burger J, Burger WJ, Cai XD, Capell M, Caroff S, Casaus J, Castellini G, Cervelli F, Chang YH, Chen AI, Chen GM, Chen HS, Chen Y, Cheng L, Chou HY, Choumilov E, Choutko V, Chung CH, Clark C, Clavero R, Coignet G, Consolandi C, Contin A, Corti C, Creus W, Crispoltoni M, Cui Z, Dadzie K, Dai YM, Datta A, Delgado C, Della Torre S, Demirköz MB, Derome L, Di Falco S, Dimiccoli F, Díaz C, von Doetinchem P, Dong F, Donnini F, Duranti M, Egorov A, Eline A, Eronen T, Feng J, Fiandrini E, Fisher P, Formato V, Galaktionov Y, Gallucci G, García-López RJ, Gargiulo C, Gast H, Gebauer I, Gervasi M, Ghelfi A, Giovacchini F, Gómez-Coral DM, Gong J, Goy C, Grabski V, Grandi D, Graziani M, Guo KH, Haino S, Han KC, He ZH, Heil M, Hsieh TH, Huang H, Huang ZC, Incagli M, Jia Y, Jinchi H, Kanishev K, Khiali B, Kirn T, Konak C, Kounina O, Kounine A, Koutsenko V, Kulemzin A, La Vacca G, Laudi E, Laurenti G, Lazzizzera I, Lebedev A, Lee HT, Lee SC, Leluc C, Li HS, Li JQ, Li Q, Li TX, Li ZH, Li ZY, Lin CH, Lipari P, Lippert T, Liu D, Liu H, Liu Z, Lordello VD, Lu SQ, Lu YS, Luebelsmeyer K, Luo F, Luo JZ, Lyu SS, Machate F, Mañá C, Marín J, Martin T, Martínez G, Masi N, Maurin D, Menchaca-Rocha A, Meng Q, Mikuni VM, Mo DC, Mott P, Mussolin L, Nelson T, Ni JQ, Nikonov N, Nozzoli F, Oliva A, Orcinha M, Palermo M, Palmonari F, Palomares C, Paniccia M, Pauluzzi M, Pensotti S, Perrina C, Phan HD, Picot-Clemente N, Pilo F, Plyaskin V, Pohl M, Poireau V, Quadrani L, Qi XM, Qin X, Qu ZY, Räihä T, Rancoita PG, Rapin D, Ricol JS, Rosier-Lees S, Rozhkov A, Rozza D, Sagdeev R, Schael S, Schmidt SM, Schulz von Dratzig A, Schwering G, Seo ES, Shan BS, Shi JY, Siedenburg T, Song JW, Tacconi M, Tang XW, Tang ZC, Tescaro D, Tian J, Ting SCC, Ting SM, Tomassetti N, Torsti J, Urban T, Vagelli V, Valente E, Valtonen E, Vázquez Acosta M, Vecchi M, Velasco M, Vialle JP, Wang LQ, Wang NH, Wang QL, Wang X, Wang XQ, Wang ZX, Wei CC, Wei J, Weng ZL, Whitman K, Wu H, Xiong RQ, Xu W, Yan Q, Yang M, Yang Y, Yi H, Yu YJ, Yu ZQ, Zannoni M, Zeissler S, Zhang C, Zhang F, Zhang J, Zhang JH, Zhang SW, Zhang Z, Zheng ZM, Zhuang HL, Zhukov V, Zichichi A, Zimmermann N, Zuccon P. Precision Measurement of Cosmic-Ray Nitrogen and its Primary and Secondary Components with the Alpha Magnetic Spectrometer on the International Space Station. PHYSICAL REVIEW LETTERS 2018; 121:051103. [PMID: 30118280 DOI: 10.1103/physrevlett.121.051103] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 06/06/2018] [Indexed: 06/08/2023]
Abstract
A precision measurement of the nitrogen flux with rigidity (momentum per unit charge) from 2.2 GV to 3.3 TV based on 2.2×10^{6} events is presented. The detailed rigidity dependence of the nitrogen flux spectral index is presented for the first time. The spectral index rapidly hardens at high rigidities and becomes identical to the spectral indices of primary He, C, and O cosmic rays above ∼700 GV. We observed that the nitrogen flux Φ_{N} can be presented as the sum of its primary component Φ_{N}^{P} and secondary component Φ_{N}^{S}, Φ_{N}=Φ_{N}^{P}+Φ_{N}^{S}, and we found Φ_{N} is well described by the weighted sum of the oxygen flux Φ_{O} (primary cosmic rays) and the boron flux Φ_{B} (secondary cosmic rays), with Φ_{N}^{P}=(0.090±0.002)×Φ_{O} and Φ_{N}^{S}=(0.62±0.02)×Φ_{B} over the entire rigidity range. This corresponds to a change of the contribution of the secondary cosmic ray component in the nitrogen flux from 70% at a few GV to <30% above 1 TV.
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Aguilar M, Ali Cavasonza L, Alpat B, Ambrosi G, Arruda L, Attig N, Aupetit S, Azzarello P, Bachlechner A, Barao F, Barrau A, Barrin L, Bartoloni A, Basara L, Başeğmez-du Pree S, Battarbee M, Battiston R, Becker U, Behlmann M, Beischer B, Berdugo J, Bertucci B, Bindel KF, Bindi V, de Boer W, Bollweg K, Bonnivard V, Borgia B, Boschini MJ, Bourquin M, Bueno EF, Burger J, Cadoux F, Cai XD, Capell M, Caroff S, Casaus J, Castellini G, Cervelli F, Chae MJ, Chang YH, Chen AI, Chen GM, Chen HS, Chen Y, Cheng L, Chou HY, Choumilov E, Choutko V, Chung CH, Clark C, Clavero R, Coignet G, Consolandi C, Contin A, Corti C, Creus W, Crispoltoni M, Cui Z, Dadzie K, Dai YM, Datta A, Delgado C, Della Torre S, Demirköz MB, Derome L, Di Falco S, Dimiccoli F, Díaz C, von Doetinchem P, Dong F, Donnini F, Duranti M, D'Urso D, Egorov A, Eline A, Eronen T, Feng J, Fiandrini E, Fisher P, Formato V, Galaktionov Y, Gallucci G, García-López RJ, Gargiulo C, Gast H, Gebauer I, Gervasi M, Ghelfi A, Giovacchini F, Gómez-Coral DM, Gong J, Goy C, Grabski V, Grandi D, Graziani M, Guo KH, Haino S, Han KC, He ZH, Heil M, Hoffman J, Hsieh TH, Huang H, Huang ZC, Huh C, Incagli M, Ionica M, Jang WY, Jia Y, Jinchi H, Kang SC, Kanishev K, Khiali B, Kim GN, Kim KS, Kirn T, Konak C, Kounina O, Kounine A, Koutsenko V, Kulemzin A, La Vacca G, Laudi E, Laurenti G, Lazzizzera I, Lebedev A, Lee HT, Lee SC, Leluc C, Li HS, Li JQ, Li Q, Li TX, Li ZH, Li ZY, Light C, Lim S, Lin CH, Lipari P, Lippert T, Liu D, Liu H, Lordello VD, Lu SQ, Lu YS, Luebelsmeyer K, Luo F, Luo JZ, Luo X, Lyu SS, Machate F, Mañá C, Marín J, Martin T, Martínez G, Masi N, Maurin D, Menchaca-Rocha A, Meng Q, Mikuni VM, Mo DC, Mott P, Nelson T, Ni JQ, Nikonov N, Nozzoli F, Oliva A, Orcinha M, Palermo M, Palmonari F, Palomares C, Paniccia M, Pauluzzi M, Pensotti S, Perrina C, Phan HD, Picot-Clemente N, Pilo F, Pizzolotto C, Plyaskin V, Pohl M, Poireau V, Popkow A, Quadrani L, Qi XM, Qin X, Qu ZY, Räihä T, Rancoita PG, Rapin D, Ricol JS, Rosier-Lees S, Rozhkov A, Rozza D, Sagdeev R, Schael S, Schmidt SM, Schulz von Dratzig A, Schwering G, Seo ES, Shan BS, Shi JY, Siedenburg T, Son D, Song JW, Tacconi M, Tang XW, Tang ZC, Tescaro D, Ting SCC, Ting SM, Tomassetti N, Torsti J, Türkoğlu C, Urban T, Vagelli V, Valente E, Valtonen E, Vázquez Acosta M, Vecchi M, Velasco M, Vialle JP, Wang LQ, Wang NH, Wang QL, Wang X, Wang XQ, Wang ZX, Wei CC, Weng ZL, Whitman K, Wu H, Wu X, Xiong RQ, Xu W, Yan Q, Yang J, Yang M, Yang Y, Yi H, Yu YJ, Yu ZQ, Zannoni M, Zeissler S, Zhang C, Zhang F, Zhang J, Zhang JH, Zhang SW, Zhang Z, Zheng ZM, Zhuang HL, Zhukov V, Zichichi A, Zimmermann N, Zuccon P. Observation of Fine Time Structures in the Cosmic Proton and Helium Fluxes with the Alpha Magnetic Spectrometer on the International Space Station. PHYSICAL REVIEW LETTERS 2018; 121:051101. [PMID: 30118264 DOI: 10.1103/physrevlett.121.051101] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 05/09/2018] [Indexed: 06/08/2023]
Abstract
We present the precision measurement from May 2011 to May 2017 (79 Bartels rotations) of the proton fluxes at rigidities from 1 to 60 GV and the helium fluxes from 1.9 to 60 GV based on a total of 1×10^{9} events collected with the Alpha Magnetic Spectrometer aboard the International Space Station. This measurement is in solar cycle 24, which has the solar maximum in April 2014. We observed that, below 40 GV, the proton flux and the helium flux show nearly identical fine structures in both time and relative amplitude. The amplitudes of the flux structures decrease with increasing rigidity and vanish above 40 GV. The amplitudes of the structures are reduced during the time period, which started one year after solar maximum, when the proton and helium fluxes steadily increase. Above ∼3 GV the p/He flux ratio is time independent. We observed that below ∼3 GV the ratio has a long-term decrease coinciding with the period during which the fluxes start to rise.
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Chen CH, Liu CH, Ariraman M, Lin CH, Juang TY. Phosphinated Poly(aryl ether)s with Acetic/Phenyl Methacrylic/Vinylbenzyl Ether Moieties for High- T g and Low-Dielectric Thermosets. ACS OMEGA 2018; 3:6031-6038. [PMID: 31458793 PMCID: PMC6644485 DOI: 10.1021/acsomega.8b00615] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Accepted: 05/21/2018] [Indexed: 06/10/2023]
Abstract
To achieve insulating materials with a low-dielectric characteristic for high-frequency communication applications, three phosphinated poly(aryl ether)s: P1-act (with acetic moiety), P1-mma (with phenyl methacrylic moiety), and P1-vbe (with vinylbenzyl ether moiety) were modified from a phenol-functionalized phosphinated poly(aryl ether) (P1). P1-act and P1-mma, both with active ester linkages (Ph-O-(C=O)-), were reacted with three commercial epoxy resins (diglycidyl ether of bisphenol A, HP7200, and cresol novolac epoxy) to obtain secondary hydroxyl-free epoxy thermosets. Because of the secondary hydroxyl-free structure, epoxy thermosets cured by P1-act and P1-mma show an 11-15% reduction in dielectric constant than those cured by P1. P1-vbe, with reactive vinylbenzyl ether moieties, was self-cured to a high-performance thermoset with a T g value as high as 302 °C and a dielectric constant as low as 2.64U. High-T g and low-dielectric thermosets have been developed in this work.
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