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Temporal Structures in Positron Spectra and Charge-Sign Effects in Galactic Cosmic Rays. PHYSICAL REVIEW LETTERS 2023; 131:151002. [PMID: 37897756 DOI: 10.1103/physrevlett.131.151002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2023] [Revised: 08/26/2023] [Accepted: 09/01/2023] [Indexed: 10/30/2023]
Abstract
We present the precision measurements of 11 years of daily cosmic positron fluxes in the rigidity range from 1.00 to 41.9 GV based on 3.4×10^{6} positrons collected with the Alpha Magnetic Spectrometer (AMS) aboard the International Space Station. The positron fluxes show distinctly different time variations from the electron fluxes at short and long timescales. A hysteresis between the electron fluxes and the positron fluxes is observed with a significance greater than 5σ at rigidities below 8.5 GV. On the contrary, the positron fluxes and the proton fluxes show similar time variation. Remarkably, we found that positron fluxes are modulated more than proton fluxes with a significance greater than 5σ for rigidities below 7 GV. These continuous daily positron fluxes, together with AMS daily electron, proton, and helium fluxes over an 11-year solar cycle, provide unique input to the understanding of both the charge-sign and mass dependencies of cosmic rays in the heliosphere.
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[Mechanism of intestinal injury induced by WNT2B high-expressed fibroblasts in Crohn's disease]. ZHONGHUA ER KE ZA ZHI = CHINESE JOURNAL OF PEDIATRICS 2023; 61:606-613. [PMID: 37385803 DOI: 10.3760/cma.j.cn112140-20221202-01022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Subscribe] [Scholar Register] [Indexed: 07/01/2023]
Abstract
Objective: To explore the mechanism of intestinal tissue damage induced by macrophages activated by WNT2B high-expressed fibroblasts. Methods: This study involved biological information analysis, pathological tissue research and cell experimental research. The biological information of the colon tissue from the children with inflammatory bowel disease in previous study was analyzed again with single-cell sequencing. The pathological tissues were collected by colonoscopy from 10 children with Crohn's disease treated in the Department of Gastroenterology of Guangzhou Women and Children's Medical Center from July 2022 to September 2022. According to the findings of colonoscopy, tissues with obvious inflammation or ulceration were classified as the inflammatory group, while tissues with slight inflammation and no ulceration were classified as the non-inflammatory group. HE staining was performed to observe the pathological changes of the colon tissues. Macrophage infiltration and CXCL12 expression were detected by immunofluorescence. In terms of cell experiments, fibroblasts transfected with WNT2B plasmid or empty plasmid were co-cultured with salinomycin treated or non-treated macrophages, respectively; the expression of proteins through Wnt classical pathway were detected by western blotting. Macrophages treated with SKL2001 were used as the experimental group, and those with phosphate buffer as the control group. The expression and secretion of CXCL12 in macrophages were detected by quantitative Real-time PCR and enzyme-linked immunosorbent assay (ELISA). T-test or rank sum test were used for the comparison between groups. Results: Single-cell sequencing analysis suggested that macrophages were the main cells in inflammatory bowel disease colon tissue, and there was interaction between WNT2B high-expressed fibroblasts and macrophages. HE staining of the 10 patients ((9.3±3.8) years old, 7 males and 3 females) showed that the pathological score of colon tissue in the inflammatory group was higher than that in the non-inflammatory group (4 (3, 4) vs. 2 (1, 2) points, Z=3.05, P=0.002). Tissue immunofluorescence indicated that the number of infiltrating macrophages in the inflammatory group was significantly higher than that in the non-inflammatory group under high power field of view (72.8±10.4 vs.8.4±3.5, t=25.10, P<0.001), as well as the number of cells expressing CXCL12 (14.0±3.5 vs. 4.7±1.9, t=14.68, P<0.001). In cell experiments, western blotting suggested an elevated level of glycogen synthase kinase-3β phosphorylation in macrophages co-cultured with fibroblast transfected with WNT2B plasmid, and salinmycin could reverse this change. Real-time PCR suggested that the transcription level of CXCL12 in the experimental group was higher than that in the control group (6.42±0.04 vs. 1.00±0.03, t=183.00, P<0.001), as well as the expression and secretion of CXCL12 by ELISA ((465±34) vs. (77±9) ng/L, t=13.21, P=0.006). Conclusion: WNT2B high-expressed fibroblasts can secrete WNT2B protein and activate the Wnt classical signaling pathway thus enhancing the expression and secretion of CXCL12 in macrophages, inducing the development of intestinal inflammation of Crohn's disease.
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Properties of Cosmic-Ray Sulfur and Determination of the Composition of Primary Cosmic-Ray Carbon, Neon, Magnesium, and Sulfur: Ten-Year Results from the Alpha Magnetic Spectrometer. PHYSICAL REVIEW LETTERS 2023; 130:211002. [PMID: 37295095 DOI: 10.1103/physrevlett.130.211002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 03/28/2023] [Accepted: 04/27/2023] [Indexed: 06/12/2023]
Abstract
We report the properties of primary cosmic-ray sulfur (S) in the rigidity range 2.15 GV to 3.0 TV based on 0.38×10^{6} sulfur nuclei collected by the Alpha Magnetic Spectrometer experiment (AMS). We observed that above 90 GV the rigidity dependence of the S flux is identical to the rigidity dependence of Ne-Mg-Si fluxes, which is different from the rigidity dependence of the He-C-O-Fe fluxes. We found that, similar to N, Na, and Al cosmic rays, over the entire rigidity range, the traditional primary cosmic rays S, Ne, Mg, and C all have sizeable secondary components, and the S, Ne, and Mg fluxes are well described by the weighted sum of the primary silicon flux and the secondary fluorine flux, and the C flux is well described by the weighted sum of the primary oxygen flux and the secondary boron flux. The primary and secondary contributions of the traditional primary cosmic-ray fluxes of C, Ne, Mg, and S (even Z elements) are distinctly different from the primary and secondary contributions of the N, Na, and Al (odd Z elements) fluxes. The abundance ratio at the source for S/Si is 0.167±0.006, for Ne/Si is 0.833±0.025, for Mg/Si is 0.994±0.029, and for C/O is 0.836±0.025. These values are determined independent of cosmic-ray propagation.
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Temporal Structures in Electron Spectra and Charge Sign Effects in Galactic Cosmic Rays. PHYSICAL REVIEW LETTERS 2023; 130:161001. [PMID: 37154630 DOI: 10.1103/physrevlett.130.161001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 11/21/2022] [Accepted: 02/09/2023] [Indexed: 05/10/2023]
Abstract
We present the precision measurements of 11 years of daily cosmic electron fluxes in the rigidity interval from 1.00 to 41.9 GV based on 2.0×10^{8} electrons collected with the Alpha Magnetic Spectrometer (AMS) aboard the International Space Station. The electron fluxes exhibit variations on multiple timescales. Recurrent electron flux variations with periods of 27 days, 13.5 days, and 9 days are observed. We find that the electron fluxes show distinctly different time variations from the proton fluxes. Remarkably, a hysteresis between the electron flux and the proton flux is observed with a significance of greater than 6σ at rigidities below 8.5 GV. Furthermore, significant structures in the electron-proton hysteresis are observed corresponding to sharp structures in both fluxes. This continuous daily electron data provide unique input to the understanding of the charge sign dependence of cosmic rays over an 11-year solar cycle.
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Properties of Daily Helium Fluxes. PHYSICAL REVIEW LETTERS 2022; 128:231102. [PMID: 35749176 DOI: 10.1103/physrevlett.128.231102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 05/06/2022] [Indexed: 06/15/2023]
Abstract
We present the precision measurement of 2824 daily helium fluxes in cosmic rays from May 20, 2011 to October 29, 2019 in the rigidity interval from 1.71 to 100 GV based on 7.6×10^{8} helium nuclei collected with the Alpha Magnetic Spectrometer (AMS) aboard the International Space Station. The helium flux and the helium to proton flux ratio exhibit variations on multiple timescales. In nearly all the time intervals from 2014 to 2018, we observed recurrent helium flux variations with a period of 27 days. Shorter periods of 9 days and 13.5 days are observed in 2016. The strength of all three periodicities changes with time and rigidity. In the entire time period, we found that below ∼7 GV the helium flux exhibits larger time variations than the proton flux, and above ∼7 GV the helium to proton flux ratio is time independent. Remarkably, below 2.4 GV a hysteresis between the helium to proton flux ratio and the helium flux was observed at greater than the 7σ level. This shows that at low rigidity the modulation of the helium to proton flux ratio is different before and after the solar maximum in 2014.
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Periodicities in the Daily Proton Fluxes from 2011 to 2019 Measured by the Alpha Magnetic Spectrometer on the International Space Station from 1 to 100 GV. PHYSICAL REVIEW LETTERS 2021; 127:271102. [PMID: 35061443 DOI: 10.1103/physrevlett.127.271102] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 09/24/2021] [Accepted: 11/08/2021] [Indexed: 06/14/2023]
Abstract
We present the precision measurement of the daily proton fluxes in cosmic rays from May 20, 2011 to October 29, 2019 (a total of 2824 days or 114 Bartels rotations) in the rigidity interval from 1 to 100 GV based on 5.5×10^{9} protons collected with the Alpha Magnetic Spectrometer aboard the International Space Station. The proton fluxes exhibit variations on multiple timescales. From 2014 to 2018, we observed recurrent flux variations with a period of 27 days. Shorter periods of 9 days and 13.5 days are observed in 2016. The strength of all three periodicities changes with time and rigidity. The rigidity dependence of the 27-day periodicity is different from the rigidity dependences of 9-day and 13.5-day periods. Unexpectedly, the strength of 9-day and 13.5-day periodicities increases with increasing rigidities up to ∼10 GV and ∼20 GV, respectively. Then the strength of the periodicities decreases with increasing rigidity up to 100 GV.
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Erratum: Properties of a New Group of Cosmic Nuclei: Results from the Alpha Magnetic Spectrometer on Sodium, Aluminum, and Nitrogen [Phys. Rev. Lett. 127, 021101 (2021)]. PHYSICAL REVIEW LETTERS 2021; 127:159901. [PMID: 34678040 DOI: 10.1103/physrevlett.127.159901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Indexed: 06/13/2023]
Abstract
This corrects the article DOI: 10.1103/PhysRevLett.127.021101.
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Properties of a New Group of Cosmic Nuclei: Results from the Alpha Magnetic Spectrometer on Sodium, Aluminum, and Nitrogen. PHYSICAL REVIEW LETTERS 2021; 127:021101. [PMID: 34296911 DOI: 10.1103/physrevlett.127.021101] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 04/30/2021] [Accepted: 06/01/2021] [Indexed: 06/13/2023]
Abstract
We report the properties of sodium (Na) and aluminum (Al) cosmic rays in the rigidity range 2.15 GV to 3.0 TV based on 0.46 million sodium and 0.51 million aluminum nuclei collected by the Alpha Magnetic Spectrometer experiment on the International Space Station. We found that Na and Al, together with nitrogen (N), belong to a distinct cosmic ray group. In this group, we observe that, similar to the N flux, both the Na flux and Al flux are well described by the sums of a primary cosmic ray component (proportional to the silicon flux) and a secondary cosmic ray component (proportional to the fluorine flux). The fraction of the primary component increases with rigidity for the N, Na, and Al fluxes and becomes dominant at the highest rigidities. The Na/Si and Al/Si abundance ratios at the source, 0.036±0.003 for Na/Si and 0.103±0.004 for Al/Si, are determined independent of cosmic ray propagation.
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Properties of Heavy Secondary Fluorine Cosmic Rays: Results from the Alpha Magnetic Spectrometer. PHYSICAL REVIEW LETTERS 2021; 126:081102. [PMID: 33709764 DOI: 10.1103/physrevlett.126.081102] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Accepted: 01/22/2021] [Indexed: 06/12/2023]
Abstract
Precise knowledge of the charge and rigidity dependence of the secondary cosmic ray fluxes and the secondary-to-primary flux ratios is essential in the understanding of cosmic ray propagation. We report the properties of heavy secondary cosmic ray fluorine F in the rigidity R range 2.15 GV to 2.9 TV based on 0.29 million events collected by the Alpha Magnetic Spectrometer experiment on the International Space Station. The fluorine spectrum deviates from a single power law above 200 GV. The heavier secondary-to-primary F/Si flux ratio rigidity dependence is distinctly different from the lighter B/O (or B/C) rigidity dependence. In particular, above 10 GV, the F/Si/B/O ratio can be described by a power law R^{δ} with δ=0.052±0.007. This shows that the propagation properties of heavy cosmic rays, from F to Si, are different from those of light cosmic rays, from He to O, and that the secondary cosmic rays have two classes.
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Properties of Iron Primary Cosmic Rays: Results from the Alpha Magnetic Spectrometer. PHYSICAL REVIEW LETTERS 2021; 126:041104. [PMID: 33576661 DOI: 10.1103/physrevlett.126.041104] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 11/22/2020] [Accepted: 12/09/2020] [Indexed: 06/12/2023]
Abstract
We report the observation of new properties of primary iron (Fe) cosmic rays in the rigidity range 2.65 GV to 3.0 TV with 0.62×10^{6} iron nuclei collected by the Alpha Magnetic Spectrometer experiment on the International Space Station. Above 80.5 GV the rigidity dependence of the cosmic ray Fe flux is identical to the rigidity dependence of the primary cosmic ray He, C, and O fluxes, with the Fe/O flux ratio being constant at 0.155±0.006. This shows that unexpectedly Fe and He, C, and O belong to the same class of primary cosmic rays which is different from the primary cosmic rays Ne, Mg, and Si class.
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[Role of autophagy in inner ear and related research progress]. ZHONGHUA ER BI YAN HOU TOU JING WAI KE ZA ZHI = CHINESE JOURNAL OF OTORHINOLARYNGOLOGY HEAD AND NECK SURGERY 2020; 55:1086-1090. [PMID: 33210894 DOI: 10.3760/cma.j.cn115330-20200512-00400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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[Research progress on pathogenesis and intervention of presbycusis]. ZHONGHUA ER BI YAN HOU TOU JING WAI KE ZA ZHI = CHINESE JOURNAL OF OTORHINOLARYNGOLOGY HEAD AND NECK SURGERY 2020; 55:1105-1110. [PMID: 33210898 DOI: 10.3760/cma.j.cn115330-20191218-00763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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[Molecular identification of Tricula spp. and the parasitized trematode cercariae in schistosomiasis-endemic areas of Yunnan Province]. ZHONGGUO XUE XI CHONG BING FANG ZHI ZA ZHI = CHINESE JOURNAL OF SCHISTOSOMIASIS CONTROL 2020; 32:159-167. [PMID: 32458605 DOI: 10.16250/j.32.1374.2019187] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE To characterize a species of the genus Tricula and parasitized trematodes in schistosomiasis-endemic areas of Yunnan Province using a molecular analysis, so as to understand their taxonomic positions. METHODS Tricula spp. and Oncomelania snails were collected from Xiangyun County, Yunnan Province, and cercaria parasitizing snails were observed using crushing followed by microscopy. Cercaria parasitizing Tricula snails at various morphologies were sampled using a shedding method. Genomic DNA was extracted from snail soft tissues and cercariae, and the 16S rRNA, COI, 28S rDNA genes in snails and the ND1 and 28S rDNA genes in cercariae were amplified using a PCR assay and sequenced. The species of Tricula snails and their parasitized trematodes was characterized using sequence alignment and phylogenetic analysis. RESULTS Among 382 Tricula snails detected, there were three types of trematode cercariae found, including the non-forked (20.94%, 80/382), double-forked (3.40%, 13/382) and swallow shapes (7.07%, 27/382). Sequence and phylogenetic analyses showed that the 16S rRNA, COI and 28S rDNA gene sequences of this species of Tricula had high homology to those in Delavaya dianchiensis, and were clustered in a branch. Sequencing analysis of the ND1 and 28S rDNA genes revealed that the non-forked cercariae belonged to the family Pleu- rogenidae, the swallow-shaped cercariae belonged to the family Opecoelidae, and the double-forked cercariae belonged to another species of the genus Schistosoma that was different from S. sinensium and S. ovuncatum. CONCLUSIONS The species and taxonomy of Triculla spp. and their parasitized trematodes are preliminarily determined in schistosomiasis-endemic areas of Yunnan Province; however, further studies are required to investigate the more definite taxonomy and pathogenicity.
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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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Sarri et al. Reply. PHYSICAL REVIEW LETTERS 2020; 124:179502. [PMID: 32412293 DOI: 10.1103/physrevlett.124.179502] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 04/08/2020] [Indexed: 06/11/2023]
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[MicroRNA-23a knockdown attenuates angiotensin Ⅱ induced hypertrophy in rat H9c2 cells via activating PTEN and AMPK pathway]. ZHONGHUA XIN XUE GUAN BING ZA ZHI 2020; 48:329-335. [PMID: 32370485 DOI: 10.3760/cma.j.cn112148-20190513-00244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To investigate if microRNA (miR) -23a knockdown could attenuate angiotensin Ⅱ(AngⅡ) induced cardiac hypertrophy by activating phosphatase and tensin homolog deleted on chromosome ten(PTEN) and AMP-activated protein kinase(AMPK) pathway. Methods: Rat H9c2 cells were cultured in DMEM high glucose medium and put in 5% CO(2) incubator at 37 ℃(normal group). After 48 hours of culture, H9c2 cells were stimulated with 10 nmol/L AngⅡ to establish cell hypertrophy model (AngⅡgroup). The H9c2 cells were inoculated in a 6-well cell culture plate and cultured in an incubator at 37 ℃. When the confluence degree of cell growth was about 70%, the cells were transfected with different reagents, and 24 hours after transfection, 10 nmol/L AngⅡ was used to interfere with the cells. The H9c2 cells were divided into different groups according to the reagents, namely AngⅡ+anti-miR group(transfected with miR-23a inhibitor), Ang Ⅱ+NC group(transfected with miR-23a inhibitor negative control), Ang Ⅱ+anti-miR+si-PTEN group(cotransfected with miR-23a inhibitor and PTEN small interference RNA(siRNA)), and AngⅡ+anti-miR+si-NC group(cotransfected with miR-23a inhibitor and PTEN siRNA negative control). The surface area of single cell was measured by Image J software.The mRNA expression levels of α-actin 1 (ACTA1) and β-myosin heavy chain (β-MHC) and miR-23a were detected by quantitative real-time PCR(qRT-PCR). The expression levels of PTEN and AMPK signal pathway related proteins were detected by Western blot. In order to verify whether miR-23a targets PTEN gene, double luciferase reporter gene experiment was performed. The luciferase reporter gene vector recombinant plasmids of wild type pGL-WT-PTEN and mutant pGL-MUT-PTEN were constructed and prepared after normal sequencing. H9c2 cells was inoculated into 24-well cell culture plate and cultured overnight in 37 ℃ incubator. The cells were co-transfected with miR-23a mimic or miR-23a mimic negative control and wild type or mutant reporter gene recombinant plasmid. Forty-eight hours after transfection, firefly luciferase activity and sea kidney luciferase activity were measured, and the ratio of them was recorded as relative luciferase activity. Results: Compared with the normal group, the cell surface area, the mRNA expression levels of ACTA1, β-MHC and miR-23a were significantly higher, while the protein expression levels of PTEN and p-AMPK were significantly lower in the Ang Ⅱ group(all P<0.05). The results of double luciferase reporter gene assay showed that the relative luciferase activity of cells co-transfected with miR-23a mimic and wild-type reporter gene recombinant plasmid was lower than that of miR-23a mimic negative control (P<0.05), and PTEN served as the target gene of miR-23a. In AngⅡ+anti-miR group the mRNA expression levels of miR-23a, ACTA1 and β-MHC were lower, and the cell surface area was smaller, while the protein expression levels of PTEN and p-AMPK were higher than that in AngⅡ group and AngⅡ+NC group(all P<0.05). Compared with AngⅡ+anti-miR group, the cell surface area was bigger, the expression of ACTA1 and β-MHC mRNA was up-regulated, and the protein expression levels of PTEN and p-AMPK were down-regulated in Ang Ⅱ+anti-miR+si-PTEN group(all P<0.05). Conclusion: Inhibition of miR-23a can attenuate Ang Ⅱ-induced hypertrophy in H9c2 cells through targeting PTEN and activating AMPK signaling pathway.
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Piezoelectric modulation of broadband photoresponse of flexible tellurium nanomesh photodetectors. NANOTECHNOLOGY 2020; 31:095502. [PMID: 31675732 DOI: 10.1088/1361-6528/ab53b3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Flexible photodetector shows great potential applications in intelligent wearable devices, health monitoring, and biological sensing. In this work, single crystal β-tellurium nanowires were grown on flexible muscovite by molecular beam epitaxy, constructing high-density ordered nanomesh structure. The prepared photodetectors based on tellurium nanomesh exhibit excellent mechanical flexibility, fast response in a broad range from ultraviolet to near-infrared, and good photosensitivity. We found that the flexible photodetectors with Shottky contact drastically suppressed dark current, while the response speed was lowered in comparison to the devices with ohmic contact, as holes would take a long time to tunnel through the Shottky barrier between metal and p-type Te. Moreover, the photoresponse of flexible Shottky photodetectors can be modulated by piezoelectricity of tellurium, and pronounced photocurrent increase after bending many times. Under external stress, polarization charges could tune Shottky barrier height of the metal/tellurium, resulting in variation of photocurrent. This research not only explores the broadband photoresponse and piezoelectric effect of tellurium nanomesh, but also promotes the integration and development of broadband flexible optoelectronic devices.
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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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Abstract
Tetraphenylethylene (TPE) related (supra)molecules have been intensively investigated due to their aggregation-induced emission (AIE) effect based on the restriction of intramolecular rotation (RIR). Meanwhile, boron-dipyrromethene (BODIPY) tends to emit intense fluorescence with high quantum yields. Herein, we combined TPE, BODIPY and terpyridine (TPY) into one system to study the emissive behaviour of organic building block as well as a self-assembled metallo-supramolecule. The TPY and BODIPY substituents with bulky sizes provide strong hindrance to restrict the rotation of the phenyl groups on TPE, leading to enhancement of emissive properties in both solution and aggregation states. Furthermore, the BODIPY-TPE-TPY ligand (L) was assembled with Zn (II) through coordination-driven self-assembly to form a cyclic dimer (D) with typical AIE characteristics.
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Linear scaling algorithm for tight-binding molecular dynamics simulations. J Chem Phys 2019; 150:114107. [PMID: 30902004 DOI: 10.1063/1.5088918] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The linear scaling or O(N) methods, which exhibit linear scaling with respect to the size of system, are a powerful tool for theoretically treating a huge system containing many atoms. We present a new linear scaling algorithm for large-scale tight-binding molecular dynamics simulations based on the divide-and-conquer approach, in which a system is divided into subsystems and each subsystem is calculated separately. Different from the common realization of the divide-and-conquer approach, our proposed method avoids building the density matrix or electronic density and gives a new strategy to access the physical properties of a large system. We apply this method to the tungsten metallic system and show that this method very effectively yields the same results including the atomic structures, the melting point, the formation energy of defects, and the electronic properties as those obtained from the exact diagonalization of tight-binding Hamiltonian matrix of a whole system. This method has the advantages of linear scaling complexity, less memory consumption, and high parallel efficiency, which make it to be used for the large-scale simulations.
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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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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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[The Wuhan Twin Birth Cohort Study]. ZHONGHUA LIU XING BING XUE ZA ZHI = ZHONGHUA LIUXINGBINGXUE ZAZHI 2018; 39:1281-1286. [PMID: 30293325 DOI: 10.3760/cma.j.issn.0254-6450.2018.09.026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The prevalence of child and adolescent growth and mental-behavior related diseases are increasing, and the pathogenesis are complex. Twins are excellent natural resources for complex chronic diseases research as they share the maternal intrauterine environment, born at the same time and share the same family environment in early years, which could benefit the adjust ment of confounding factors, such as age, genetic factors and early family environmental factors. Birth cohort with twin families involved could be more effective in exploring the genetic and environmental factors for complex chronic diseases at the very beginning of life. This paper summarizes the objective, content, progress, strengths and potential problems of Wuhan Twin Birth Cohort, with emphasis on the overall design and progress of the study.
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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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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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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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Observation of New Properties of Secondary Cosmic Rays Lithium, Beryllium, and Boron by the Alpha Magnetic Spectrometer on the International Space Station. PHYSICAL REVIEW LETTERS 2018; 120:021101. [PMID: 29376729 DOI: 10.1103/physrevlett.120.021101] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Indexed: 06/07/2023]
Abstract
We report on the observation of new properties of secondary cosmic rays Li, Be, and B measured in the rigidity (momentum per unit charge) range 1.9 GV to 3.3 TV with a total of 5.4×10^{6} nuclei collected by AMS during the first five years of operation aboard the International Space Station. The Li and B fluxes have an identical rigidity dependence above 7 GV and all three fluxes have an identical rigidity dependence above 30 GV with the Li/Be flux ratio of 2.0±0.1. The three fluxes deviate from a single power law above 200 GV in an identical way. This behavior of secondary cosmic rays has also been observed in the AMS measurement of primary cosmic rays He, C, and O but the rigidity dependences of primary cosmic rays and of secondary cosmic rays are distinctly different. In particular, above 200 GV, the secondary cosmic rays harden more than the primary cosmic rays.
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[Human papillomavirus infection and vaccination]. ZHONGHUA YU FANG YI XUE ZA ZHI [CHINESE JOURNAL OF PREVENTIVE MEDICINE] 2018; 52:106-112. [PMID: 29334719 DOI: 10.3760/cma.j.issn.0253-9624.2018.01.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Human papillomavirus (HPV) is an infection that can be sexually transmitted and result in health consequences. Persistent high-risk HPV infection can lead to various cancers and is the essential cause of cervical cancer. HPV vaccine can prevent the HPV infection and thus the incidence of cervical cancer. In this review we introduced the prevalence of HPV infection and vaccination, and the prevention and early detection of cervical cancer. We also introduced the present knowledge and awareness of HPV infection and HPV vaccine in Chinese. Propaganda all over China should be performed on HPV vaccination to improve the vaccination rate, thus preventing the incidence of cervical cancer.
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Observation of the Identical Rigidity Dependence of He, C, and O Cosmic Rays at High Rigidities by the Alpha Magnetic Spectrometer on the International Space Station. PHYSICAL REVIEW LETTERS 2017; 119:251101. [PMID: 29303302 DOI: 10.1103/physrevlett.119.251101] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Indexed: 06/07/2023]
Abstract
We report the observation of new properties of primary cosmic rays He, C, and O measured in the rigidity (momentum/charge) range 2 GV to 3 TV with 90×10^{6} helium, 8.4×10^{6} carbon, and 7.0×10^{6} oxygen nuclei collected by the Alpha Magnetic Spectrometer (AMS) during the first five years of operation. Above 60 GV, these three spectra have identical rigidity dependence. They all deviate from a single power law above 200 GV and harden in an identical way.
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Precision Measurement of the Boron to Carbon Flux Ratio in Cosmic Rays from 1.9 GV to 2.6 TV with the Alpha Magnetic Spectrometer on the International Space Station. PHYSICAL REVIEW LETTERS 2016; 117:231102. [PMID: 27982618 DOI: 10.1103/physrevlett.117.231102] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Indexed: 06/06/2023]
Abstract
Knowledge of the rigidity dependence of the boron to carbon flux ratio (B/C) is important in understanding the propagation of cosmic rays. The precise measurement of the B/C ratio from 1.9 GV to 2.6 TV, based on 2.3 million boron and 8.3 million carbon nuclei collected by AMS during the first 5 years of operation, is presented. The detailed variation with rigidity of the B/C spectral index is reported for the first time. The B/C ratio does not show any significant structures in contrast to many cosmic ray models that require such structures at high rigidities. Remarkably, above 65 GV, the B/C ratio is well described by a single power law R^{Δ} with index Δ=-0.333±0.014(fit)±0.005(syst), in good agreement with the Kolmogorov theory of turbulence which predicts Δ=-1/3 asymptotically.
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Antiproton Flux, Antiproton-to-Proton Flux Ratio, and Properties of Elementary Particle Fluxes in Primary Cosmic Rays Measured with the Alpha Magnetic Spectrometer on the International Space Station. PHYSICAL REVIEW LETTERS 2016; 117:091103. [PMID: 27610839 DOI: 10.1103/physrevlett.117.091103] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Indexed: 06/06/2023]
Abstract
A precision measurement by AMS of the antiproton flux and the antiproton-to-proton flux ratio in primary cosmic rays in the absolute rigidity range from 1 to 450 GV is presented based on 3.49×10^{5} antiproton events and 2.42×10^{9} proton events. The fluxes and flux ratios of charged elementary particles in cosmic rays are also presented. In the absolute rigidity range ∼60 to ∼500 GV, the antiproton p[over ¯], proton p, and positron e^{+} fluxes are found to have nearly identical rigidity dependence and the electron e^{-} flux exhibits a different rigidity dependence. Below 60 GV, the (p[over ¯]/p), (p[over ¯]/e^{+}), and (p/e^{+}) flux ratios each reaches a maximum. From ∼60 to ∼500 GV, the (p[over ¯]/p), (p[over ¯]/e^{+}), and (p/e^{+}) flux ratios show no rigidity dependence. These are new observations of the properties of elementary particles in the cosmos.
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Effect of bis-triazole based secondary ligands on the structure of coordination polymers generated from terephthalic acid. J COORD CHEM 2016. [DOI: 10.1080/00958972.2015.1119271] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Effect of pregnancy-specific stress on spontaneous preterm birth among Chinese people. CLIN EXP OBSTET GYN 2016; 43:103-108. [PMID: 27048027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
BACKGROUND The current evidence implicates that psychosocial stress, especially pregnancy-specific stress, is associated with the risk of spontaneous preterm birth. The aim of the present study was to determine the effect of pregnancy-specific stress on spontaneous preterm birth among Chinese people. MATERIALS AND METHODS A total of 2,189 pregnant women were enrolled and followed up until parturition from February 2011 to January 2012. Maternal pregnancy-specific stress was assessed using the revised Pregnancy Stress Rating Scale (PSRS) at third trimester in pregnancy. Socio-demographic and psychological data were collected through interviews, medical, and obstetrical examination records. RESULTS High levels of maternal pregnancy-specific stress during the third trimester increased risk of spontaneous preterm birth compared with the low and medium levels (adjusted risk ratios, 2.92; 95% confidence interval, 1.12-7.58). The first stressor from the revised PSRS includes a risk factor for the safety of infants. CONCLUSIONS High level of pregnancy-specific stress in third trimester might predict spontaneous preterm birth.
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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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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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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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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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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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Effective Resistance to Wheat Stripe Rust in a Region with High Disease Pressure. PLANT DISEASE 2014; 98:891-897. [PMID: 30708850 DOI: 10.1094/pdis-09-13-0909-re] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Stripe rust is a major fungal disease of wheat. It frequently becomes epidemic in southeastern Gansu province, a stripe rust hot spot in China. Evaluations of wheat germplasm response are crucial for developing cultivars to control the disease. In total, 57 wheat cultivars and lines from Europe and other countries, comprising 36 cultivars with documented stripe rust resistance genes and 21 with unknown genes, were tested annually with multiple races of Puccinia striiformis f. sp. tritici in the field at Tianshui in Gansu province from 1993 to 2013. Seven wheat lines were highly resistant, with infection type (IT) 0 during the entire period; 16 were moderately resistant (IT 0;-2); and 26 were moderately susceptible (IT 0;-4), with low maximum disease severity compared with the susceptible control Huixianhong. 'Strampelli' and 'Libellula', with three and five quantitative trait loci, respectively, for stripe rust resistance have displayed durable resistance in this region for four decades. Ten cultivars, including 'Lantian 15', 'Lantian 26', and 'Lantian 31', with stripe rust resistance derived from European lines, were developed in our breeding program and have made a significant impact on controlling stripe rust in southeastern Gansu. Breeding resistant cultivars with multiple adult-plant resistance genes seems to be a promising strategy in wheat breeding for managing stripe rust in this region and other hot spots.
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Quantitative trait loci of stripe rust resistance in wheat. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2013; 126:2427-49. [PMID: 23955314 PMCID: PMC3782644 DOI: 10.1007/s00122-013-2159-9] [Citation(s) in RCA: 111] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Accepted: 07/12/2013] [Indexed: 05/18/2023]
Abstract
Over thirty publications during the last 10 years have identified more than 140 QTLs for stripe rust resistance in wheat. It is likely that many of these QTLs are identical genes that have been spread through plant breeding into diverse backgrounds through phenotypic selection under stripe rust epidemics. Allelism testing can be used to differentiate genes in similar locations but in different genetic backgrounds; however, this is problematic for QTL studies where multiple loci segregate from any one parent. This review utilizes consensus maps to illustrate important genomic regions that have had effects against stripe rust in wheat, and although this methodology cannot distinguish alleles from closely linked genes, it does highlight the extent of genetic diversity for this trait and identifies the most valuable loci and the parents possessing them for utilization in breeding programs. With the advent of cheaper, high throughput genotyping technologies, it is envisioned that there will be many more publications in the near future describing ever more QTLs. This review sets the scene for the coming influx of data and will quickly enable researchers to identify new loci in their given populations.
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Pathway analysis detect potential mechanism for familial combined hyperlipidemia. EUROPEAN REVIEW FOR MEDICAL AND PHARMACOLOGICAL SCIENCES 2013; 17:1909-1915. [PMID: 23877856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
BACKGROUND Familial combined hyperlipidemia (FCHL) is the most commonly inherited hyperlipidemia in men. It constitutes a substantial risk factor for atherosclerosis patients. AIM To delineating the potential mechanism of FCHL by bioinformatics tools. MATERIALS AND METHODS In this study, Protein-Protein Interaction (PPI) network was constructed to identify the potential functional proteins and their interactive relationships in familial combined hyperlipidemia. RESULTS Our results showed that androgen receptor (AR) might play an important role in familial combined hyperlipidemia by interaction with TGIF1, NR3C1, KLK2, etc. Some pathways were also identified, such as Hedgehog signaling pathway, Phosphatidylinositol signaling system, and Long-term depression, which were all demonstrated participating in lipid metabolism in previous experiments. CONCLUSIONS Although lack of direct evidence, by PPI network construction it proved AR is a key factor in FCHL, and also demonstrated that PPI network construction is an alternative avenue for FCHL analysis.
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Table-top laser-based source of femtosecond, collimated, ultrarelativistic positron beams. PHYSICAL REVIEW LETTERS 2013; 110:255002. [PMID: 23829742 DOI: 10.1103/physrevlett.110.255002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Indexed: 06/02/2023]
Abstract
The generation of ultrarelativistic positron beams with short duration (τ(e+) ≃ 30 fs), small divergence (θ(e+) ≃ 3 mrad), and high density (n(e+) ≃ 10(14)-10(15) cm(-3)) from a fully optical setup is reported. The detected positron beam propagates with a high-density electron beam and γ rays of similar spectral shape and peak energy, thus closely resembling the structure of an astrophysical leptonic jet. It is envisaged that this experimental evidence, besides the intrinsic relevance to laser-driven particle acceleration, may open the pathway for the small-scale study of astrophysical leptonic jets in the laboratory.
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First result from the Alpha Magnetic Spectrometer on the International Space Station: precision measurement of the positron fraction in primary cosmic rays of 0.5-350 GeV. PHYSICAL REVIEW LETTERS 2013; 110:141102. [PMID: 25166975 DOI: 10.1103/physrevlett.110.141102] [Citation(s) in RCA: 123] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Indexed: 06/03/2023]
Abstract
A precision measurement by the Alpha Magnetic Spectrometer on the International Space Station of the positron fraction in primary cosmic rays in the energy range from 0.5 to 350 GeV based on 6.8 × 10(6) positron and electron events is presented. The very accurate data show that the positron fraction is steadily increasing from 10 to ∼ 250 GeV, but, from 20 to 250 GeV, the slope decreases by an order of magnitude. The positron fraction spectrum shows no fine structure, and the positron to electron ratio shows no observable anisotropy. Together, these features show the existence of new physical phenomena.
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Association of androgen receptor CAG repeat polymorphism with VO₂max response to hypoxic training in North China Han men. ACTA ACUST UNITED AC 2011; 33:794-9. [PMID: 20374306 DOI: 10.1111/j.1365-2605.2009.01027.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The purposes of this study were to investigate the distribution characteristics of CAG repeat polymorphism in exon 1 of androgen receptor gene and the association of CAG polymorphism with VO₂max response to hypoxic training in North China Han men. Sixty-five healthy young men completed a 30-day HiHiLo training (living high, exercise high and training low) in a simulated normobaric hypoxic environment. All subjects slept in 14.3-14.8% O₂ concentration, and participated in hypoxic training three times a week in 15.4% O₂ concentration. VO₂max (peak oxygen consumption) and body weight were measured before and after hypoxic training. A total of 15 repeat alleles were observed by CAG genotype analyze, in which (CAG)22 was most common. When using 21 and 22 alleles, respectively, as cut-off points, we found that the baseline body weight of two shorter genotype groups was significantly lower than that of longer ones, and that the ΔVO₂max and ΔrVO₂max (Δrelative value of VO₂max) of two shorter genotype groups were significantly higher than those of longer ones after hypoxic training. These findings indicated that AR CAG repeat polymorphism was associated with the exercise performance after simulated normobaric hypoxic HiHiLo training in North China Han men, and that the shorter genotypes had a better individual response to hypoxic training.
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Seedling and Slow Rusting Resistance to Leaf Rust in Chinese Wheat Cultivars. PLANT DISEASE 2010; 94:45-53. [PMID: 30754399 DOI: 10.1094/pdis-94-1-0045] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Identification of resistance genes is important for developing leaf rust resistant wheat (Triticum aestivum) cultivars. A total of 102 Chinese winter wheat cultivars and advanced lines were inoculated with 24 pathotypes of Puccinia triticina for postulation of leaf rust resistance genes effective at the seedling stage. These genotypes were also planted in the field for characterization of slow rusting responses to leaf rust in the 2006-07 and 2007-08 cropping seasons. Fourteen leaf rust resistance genes-Lr1, Lr2a, Lr3bg, Lr3ka, Lr14a, Lr16, Lr17a, Lr18, Lr20, Lr23, Lr24, Lr26, Lr34, and LrZH84-either singly or in combinations, were postulated in 65 genotypes, whereas known resistance genes were not identified in the other 37 accessions. Resistance gene Lr26 was present in 44 accessions. Genes Lr14a and Lr34 were each detected in seven entries. Lr1 and Lr3ka were each found in six cultivars, and five lines possessed Lr16. Lr17a and Lr18 were each identified in four lines. Three cultivars were postulated to possess Lr3bg. Genes Lr20, Lr24, and LrZH84 were each present in two cultivars. Each of the genes Lr2a and Lr23 may exist in one line. Fourteen genotypes showed slow leaf rusting resistance in two cropping seasons.
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Characterization of low-molecular-weight glutenin subunit Glu-B3 genes and development of STS markers in common wheat (Triticum aestivum L.). TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2009; 118:525-39. [PMID: 18989655 DOI: 10.1007/s00122-008-0918-9] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2008] [Accepted: 10/14/2008] [Indexed: 05/22/2023]
Abstract
Low-molecular-weight glutenin subunit (LMW-GS) Glu-B3 has a significant influence on the processing quality of the end-use products of common wheat. To characterize the LMW-GS genes at the Glu-B3 locus, gene-specific PCR primers were designed to amplify eight near-isogenic lines and Cheyenne with different Glu-B3 alleles (a, b, c, d, e, f, g, h and i) defined by protein electrophoretic mobility. The complete coding regions of four Glu-B3 genes with complete coding sequence were obtained and designated as GluB3-1, GluB3-2, GluB3-3 and GluB3-4. Ten allele-specific PCR markers designed from the SNPs present in the sequenced variants discriminated the Glu-B3 proteins of electrophoretic mobility alleles a, b, c, d, e, f, g, h and i. These markers were validated on 161 wheat varieties and advanced lines with different Glu-B3 alleles, thus confirming that the markers can be used in marker-assisted breeding for wheat grain processing quality.
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Molecular mapping of leaf rust resistance gene LrZH84 in Chinese wheat line Zhou 8425B. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2008; 117:1069-75. [PMID: 18651124 DOI: 10.1007/s00122-008-0845-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2008] [Accepted: 07/05/2008] [Indexed: 05/08/2023]
Abstract
Leaf rust, caused by Puccinia triticina, is one of the most widespread diseases in common wheat (Triticum aestivum L.) worldwide. With the objective of identifying and mapping new genes for resistance to leaf rust, F(1), F(2) plants and F(3) lines from a cross between resistant line Zhou 8425B and susceptible line Chinese Spring were inoculated with Chinese P. triticina races THTT and MBHP in the greenhouse. A total of 793 pairs of SSR primers were used to test the parents and resistant and susceptible bulks. Seven polymorphic chromosome 1B markers were used for genotyping the F(2) and F(3) populations. Zhou 8425B carried a single dominant resistance gene, temporarily designated LrZH84, linked to SSR markers gwm582 and barc8 with genetic distances of 3.9 and 5.2 cM, respectively. The Xbarc8 allele co-segregated with Lr26 in the F(3) population. The Xgwm582 allele associated with LrZH84 was identified as a leaf rust resistance gene and shown to be present in the Predgornaia 2 parent of Zhou 8425B. The seedling reaction pattern of LrZH84 was different from those of lines with Lr26, Lr33, Lr44 and Lr46, all of which are located in chromosome 1B. It was concluded that LrZH84 is likely to be a new leaf rust resistance gene.
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The adult plant rust resistance loci Lr34/Yr18 and Lr46/Yr29 are important determinants of partial resistance to powdery mildew in bread wheat line Saar. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2008; 116:1155-66. [PMID: 18347772 DOI: 10.1007/s00122-008-0743-1] [Citation(s) in RCA: 155] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2007] [Accepted: 03/01/2008] [Indexed: 05/18/2023]
Abstract
Powdery mildew, caused by Blumeria graminis f. sp. tritici is a major disease of wheat (Triticum aestivum L.) that can be controlled by resistance breeding. The CIMMYT bread wheat line Saar is known for its good level of partial and race non-specific resistance, and the aim of this study was to map QTLs for resistance to powdery mildew in a population of 113 recombinant inbred lines from a cross between Saar and the susceptible line Avocet. The population was tested over 2 years in field trials at two locations in southeastern Norway and once in Beijing, China. SSR markers were screened for association with powdery mildew resistance in a bulked segregant analysis, and linkage maps were created based on selected SSR markers and supplemented with DArT genotyping. The most important QTLs for powdery mildew resistance derived from Saar were located on chromosomes 7DS and 1BL and corresponded to the adult plant rust resistance loci Lr34/Yr18 and Lr46/Yr29. A major QTL was also located on 4BL with resistance contributed by Avocet. Additional QTLs were detected at 3AS and 5AL in the Norwegian testing environments and at 5BS in Beijing. The population was also tested for leaf rust (caused by Puccinia triticina) and stripe rust (caused by P. striiformis f. sp. tritici) resistance and leaf tip necrosis in Mexico. QTLs for these traits were detected on 7DS and 1BL at the same positions as the QTLs for powdery mildew resistance, and confirmed the presence of Lr34/Yr18 and Lr46/Yr29 in Saar. The powdery mildew resistance gene at the Lr34/Yr18 locus has recently been named Pm38. The powdery mildew resistance gene at the Lr46/Yr29 locus is designated as Pm39.
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The adult plant rust resistance loci Lr34/Yr18 and Lr46/Yr29 are important determinants of partial resistance to powdery mildew in bread wheat line Saar. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2008. [PMID: 18347772 DOI: 10.1007/s00122‐008‐0743‐1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 09/29/2022]
Abstract
Powdery mildew, caused by Blumeria graminis f. sp. tritici is a major disease of wheat (Triticum aestivum L.) that can be controlled by resistance breeding. The CIMMYT bread wheat line Saar is known for its good level of partial and race non-specific resistance, and the aim of this study was to map QTLs for resistance to powdery mildew in a population of 113 recombinant inbred lines from a cross between Saar and the susceptible line Avocet. The population was tested over 2 years in field trials at two locations in southeastern Norway and once in Beijing, China. SSR markers were screened for association with powdery mildew resistance in a bulked segregant analysis, and linkage maps were created based on selected SSR markers and supplemented with DArT genotyping. The most important QTLs for powdery mildew resistance derived from Saar were located on chromosomes 7DS and 1BL and corresponded to the adult plant rust resistance loci Lr34/Yr18 and Lr46/Yr29. A major QTL was also located on 4BL with resistance contributed by Avocet. Additional QTLs were detected at 3AS and 5AL in the Norwegian testing environments and at 5BS in Beijing. The population was also tested for leaf rust (caused by Puccinia triticina) and stripe rust (caused by P. striiformis f. sp. tritici) resistance and leaf tip necrosis in Mexico. QTLs for these traits were detected on 7DS and 1BL at the same positions as the QTLs for powdery mildew resistance, and confirmed the presence of Lr34/Yr18 and Lr46/Yr29 in Saar. The powdery mildew resistance gene at the Lr34/Yr18 locus has recently been named Pm38. The powdery mildew resistance gene at the Lr46/Yr29 locus is designated as Pm39.
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Characterization of phytoene synthase 1 gene (Psy1) located on common wheat chromosome 7A and development of a functional marker. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2008; 116:213-21. [PMID: 17943267 DOI: 10.1007/s00122-007-0660-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2007] [Accepted: 09/27/2007] [Indexed: 05/08/2023]
Abstract
Phytoene synthase (Psy), a critical enzyme in the carotenoid biosynthetic pathway, demonstrated high association with the yellow pigment (YP) content in wheat grain. Characterization of Psy genes and the development of functional markers for them are of importance for marker-assisted selection in wheat breeding. In this study, the full-length genomic DNA sequence of a Psy gene (Psy-A1) located on chromosome 7A, was characterized by in silico cloning and experimental validation. The cloned Psy-A1 comprises six exons and five introns, 4,175 bp in total, and an ORF of 1,284 bp. A co-dominant marker, YP7A, was developed based on polymorphisms of two haplotypes of Psy-A1, yielding 194 and 231-bp fragments in cultivars with high and low YP content, respectively. The marker YP7A was mapped on chromosome 7AL using an RIL population from cross PH82-2/Neixing 188, and a set of Chinese Spring nullisomic-tetrasomic lines and ditelosomic line 7AS. Psy-A1, co-segregating with the STS marker YP7A, was linked to SSR marker Xwmc809 on chromosome 7AL with a genetic distance of 5.8 cM, and explained 20-28% of the phenotypic variance for YP content across three environments. A total of 217 Chinese wheat cultivars and advanced lines were used to validate the association between the polymorphic band pattern and grain YP content. The results showed that the functional marker YP7A was closely related to grain YP content and, therefore, could be used in wheat breeding programs targeting of YP content for various wheat-based products.
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