Articles de revues : « Clock transition spectroscopy »

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Sun, Yuxin, Yuan Yao, Yaqin Hao, Hongfu Yu, Yanyi Jiang et Longsheng Ma. « Laser stabilizing to ytterbium clock transition with Rabi and Ramsey spectroscopy ». Chinese Optics Letters 18, n^o 7 (2020) : 070201. http://dx.doi.org/10.3788/col202018.070201.

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Guo Feng, 郭峰, 孔德欢 Kong Dehuan, 张强 Zhang Qiang, 王叶兵 Wang Yebing et 常宏 Chang Hong. « System Development and Clock Transition Spectroscopy Detection of Transportable 87Sr Optical Clock ». Acta Optica Sinica 40, n^o 9 (2020) : 0902001. http://dx.doi.org/10.3788/aos202040.0902001.

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Wang, Yebing, Xiaotong Lu, Benquan Lu, Dehuan Kong et Hong Chang. « Recent Advances Concerning the 87Sr Optical Lattice Clock at the National Time Service Center ». Applied Sciences 8, n^o 11 (8 novembre 2018) : 2194. http://dx.doi.org/10.3390/app8112194.

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We review recent experimental progress concerning the 87Sr optical lattice clock at the National Time Service Center in China. Hertz-level spectroscopy of the 87Sr clock transition for the optical lattice clock was performed, and closed-loop operation of the optical lattice clock was realized. A fractional frequency instability of 2.8 × 10−17 was attained for an averaging time of 2000 s. The Allan deviation is found to be 1.6 × 10−15/τ1/2 and is limited mainly by white-frequency-noise. The Landé g-factors of the (5s2)1S0 and (5s5p)3P0 states in 87Sr were measured experimentally; they are important for evaluating the clock’s Zeeman shifts. We also present recent work on the miniaturization of the strontium optical lattice clock for space applications.

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Bober, M., J. Zachorowski, W. Gawlik, P. Morzyński, M. Zawada, D. Lisak, A. Cygan et al. « Precision spectroscopy of cold strontium atoms, towards optical atomic clock ». Bulletin of the Polish Academy of Sciences : Technical Sciences 60, n^o 4 (1 décembre 2012) : 707–10. http://dx.doi.org/10.2478/v10175-012-0082-x.

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Abstract This report concerns the experiment of precision spectroscopy of cold strontium atoms in the Polish National Laboratory of Atomic, Molecular and Optical Physics in Toruń. The system is composed of a Zeeman slower and magneto-optical traps (at 461 nm and 689 nm), a frequency comb, and a narrow-band laser locked to an ultra-stable optical cavity. All parts of the experiment are prepared and the first measurements of the absolute frequency of the 1S0-3P1, 689 nm optical transition in 88Sr atoms are performed.

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YE, JUN, SEBASTIAN BLATT, MARTIN M. BOYD, SETH M. FOREMAN, ERIC R. HUDSON, TETSUYA IDO, BENJAMIN LEV et al. « PRECISION MEASUREMENT BASED ON ULTRACOLD ATOMS AND COLD MOLECULES ». International Journal of Modern Physics D 16, n^o 12b (décembre 2007) : 2481–94. http://dx.doi.org/10.1142/s0218271807011826.

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Ultracold atoms and molecules provide ideal stages for precision tests of fundamental physics. With microkelvin neutral strontium atoms confined in an optical lattice, we have achieved a fractional resolution of 4 × 10-15 on the 1S0–3P0 doubly forbidden 87 Sr clock transition at 698 nm. Measurements of the clock line shifts as a function of experimental parameters indicate systematic errors below the 10-15 level. The ultrahigh spectral resolution permits resolving the nuclear spin states of the clock transition at small magnetic fields, leading to measurements of the 3P0 magnetic moment and metastable lifetime. In addition, photoassociation spectroscopy performed on the narrow 1S0–3P1 transition of 88 Sr shows promise for efficient optical tuning of the ground state scattering length and production of ultracold ground state molecules. Lattice-confined Sr 2 molecules are suitable for constraining the time variation of the proton–electron mass ratio. In a separate experiment, cold, stable, ground state polar molecules are produced from Stark decelerators. These cold samples have enabled an order-of-magnitude improvement in the measurement precision of ground state, Λ doublet microwave transitions in the OH molecule. Comparing the laboratory results to those from OH megamasers in interstellar space will allow a sensitivity of 10-6 for measuring the potential time variation of the fundamental fine structure constant Δα/α over 1010 years. These results have also led to improved understandings of the molecular structure. The study of the low magnetic field behavior of OH in its 2Π3/2 ro-vibronic ground state precisely determines a differential Landé g factor between opposite parity components of the Λ doublet.

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Arata, Toshiaki. « Myosin and Other Energy-Transducing ATPases : Structural Dynamics Studied by Electron Paramagnetic Resonance ». International Journal of Molecular Sciences 21, n^o 2 (20 janvier 2020) : 672. http://dx.doi.org/10.3390/ijms21020672.

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The objective of this article was to document the energy-transducing and regulatory interactions in supramolecular complexes such as motor, pump, and clock ATPases. The dynamics and structural features were characterized by motion and distance measurements using spin-labeling electron paramagnetic resonance (EPR) spectroscopy. In particular, we focused on myosin ATPase with actin–troponin–tropomyosin, neural kinesin ATPase with microtubule, P-type ion-motive ATPase, and cyanobacterial clock ATPase. Finally, we have described the relationships or common principles among the molecular mechanisms of various energy-transducing systems and how the large-scale thermal structural transition of flexible elements from one state to the other precedes the subsequent irreversible chemical reactions.

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Berdasov, O. I., A. Yu Gribov, G. S. Belotelov, V. G. Pal'chikov, S. A. Strelkin, K. Yu Khabarova, N. N. Kolachevsky et S. N. Slyusarev. « Ultrastable laser system for spectroscopy of the 1S0 – 3P0 clock transition in Sr atoms ». Quantum Electronics 47, n^o 5 (30 mai 2017) : 400–405. http://dx.doi.org/10.1070/qel16346.

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Gribov, A. Y., O. I. Berdasov, G. S. Belotelov, E. F. Stelmashenko, D. V. Sutyrin et S. N. Slyusarev. « The optical frequency standard based on strontium cold atoms ». Izmeritel`naya Tekhnika, n^o 12 (2020) : 22–27. http://dx.doi.org/10.32446/0368-1025it.2020-12-22-27.

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The results obtained during the development of an optical frequency standard, based on cold 87Sr atoms are presented. The parameters of experimental optical schemes developed for the realization of all stages of sequential laser cooling and trapping of 87Sr atoms into an optical lattice are described. Clock transition spectroscopy was successfully performed with a spectral transition linewidth of 12 Hz. A measuring scheme based on a femtosecond optical frequency synthesizer has been developed, which makes it possible to compare the optical standard with a hydrogen maser. The created optical frequency standard was included in the primary standard GET 1-2018.

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Wolf, Anne Lisa, Jonas Morgenweg, Jeroen C. J. Koelemeij, Steven A. van den Berg, Wim Ubachs et Kjeld S. E. Eikema. « Direct frequency-comb spectroscopy of a dipole-forbidden clock transition in trapped Ca^+40 ions ». Optics Letters 36, n^o 1 (23 décembre 2010) : 49. http://dx.doi.org/10.1364/ol.36.000049.

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Chepurov, S. V., A. A. Lugovoy, O. N. Prudnikov, A. V. Taichenachev et S. N. Bagayev. « Spectroscopy of the quadrupole clock transition of ytterbium-171 ions for optical frequency standard development ». Quantum Electronics 49, n^o 5 (20 mai 2019) : 412–17. http://dx.doi.org/10.1070/qel16996.

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Fedorova, E. S., D. O. Tregubov, A. A. Golovizin, D. A. Mishin, D. I. Provorchenko, K. Yu Khabarova, V. N. Sorokin et N. N. Kolachevsky. « Rabi spectroscopy of the clock transition in thulium atoms in a one-dimensional optical lattice ». Quantum Electronics 50, n^o 3 (13 mars 2020) : 220–24. http://dx.doi.org/10.1070/qel17259.

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Marmet, L., et A. A. Madej. « Optical Ramsey spectroscopy and coherence measurements of the clock transition in a single trapped Sr ion ». Canadian Journal of Physics 78, n^o 5-6 (5 avril 2000) : 495–507. http://dx.doi.org/10.1139/p00-027.

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We report on the observation of coherent excitation and spectroscopy performed using Ramsey's method of separated excitation fields on a single trapped and laser cooled ion of strontium. Single pulse Rabi excitation studies of the ion have shown linewidths approaching the transform limited value. Studies of transition rate versus pulse duration have shown a quadratic initial increase in transition rate with a duration consistent with coherent excitation and a rapid loss of Rabi oscillations, consistent with the concept of a dephasing of the thermally populated trap oscillator states as the excitation evolves. When two-pulse Ramsey excitation is applied to the single ion, fringe widths down to a linewidth of 840 Hz (FWHM) were observed with measured fringe contrasts consistent with a probe laser linewidth of 500 Hz.PACS Nos.: 32.80Qk, 32.30Jc, 06.30Ft

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Akamatsu, Daisuke, Hajime Inaba, Kazumoto Hosaka, Masami Yasuda, Atsushi Onae, Tomonari Suzuyama, Masaki Amemiya et Feng-Lei Hong. « Spectroscopy and frequency measurement of the87Sr clock transition by laser linewidth transfer using an optical frequency comb ». Applied Physics Express 7, n^o 1 (18 décembre 2013) : 012401. http://dx.doi.org/10.7567/apex.7.012401.

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Schröter, Christian, Jong Chan Lee et Thomas Schultz. « Mass-correlated rotational Raman spectra with high resolution, broad bandwidth, and absolute frequency accuracy ». Proceedings of the National Academy of Sciences 115, n^o 20 (27 avril 2018) : 5072–76. http://dx.doi.org/10.1073/pnas.1721756115.

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We present mass-correlated rotational alignment spectroscopy, based on the optical excitation of a coherent rotational quantum wave and the observation of temporal wave interferences in a mass spectrometer. Combined electronic and opto-mechanical delays increased the observation time and energy resolution by an order of magnitude compared with preceding time-domain measurements. Rotational transition frequencies were referenced to an external clock for accurate absolute frequency measurements. Rotational Raman spectra for six naturally occurring carbon disulfide isotopologues were resolved with 3 MHz resolution over a spectral range of 500 GHz. Rotational constants were determined with single-kilohertz accuracy, competitive with state-of-the-art frequency domain measurements.

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Wu, Bin, Zhaoying Wang, Bing Cheng, Qiyu Wang, Aopeng Xu, Delong Kong et Qiang Lin. « Experimental verification of the Breit–Rabi formula in the case of clock transition by using the spectroscopy method ». Journal of the Optical Society of America B 31, n^o 4 (12 mars 2014) : 742. http://dx.doi.org/10.1364/josab.31.000742.

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Park, S., A. E. Mironov, J. Kim, S.-J. Park et J. G. Eden. « 194 nm microplasma lamps driven by excitation transfer : optical sources for the ¹⁹⁹Hg ion atomic clock and photochemistry ». Plasma Sources Science and Technology 31, n^o 4 (1 avril 2022) : 045007. http://dx.doi.org/10.1088/1361-6595/ac5c5c.

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Abstract A series of miniature, microcavity plasma lamps emitting predominantly at 194 nm has been successfully developed and tested as the optical pump for the microwave 199Hg-ion atomic clock (40.507 GHz), replacing low pressure, RF-powered Ar/Hg discharges. Intense fluorescence on the 6p 2P1/2 → 6s 2S1/2 transition of the singly-charged 202Hg ion at 194.23 nm has been generated in arrays of cylindrical microplasmas through electron-impact excitation of He, followed by three-body formation of He2(a 3 Σ u + ) and Penning ionization of Hg. Emission spectroscopy and kinetic modeling of He/Hg vapor plasmas demonstrate that the population of the Hg+(62P1/2) radiating state (16.82 eV), produced by direct or two-step electron impact processes, is < 1% of that generated by excitation transfer to Hg by H e 2 * . Flat, fused silica lamps having emitting areas as small as 4 mm2 and containing several mg of 202Hg and 50–800 Torr of He have been fabricated and serve as optical drivers for the Hg+ atomic clock cycle. Based on small arrays of 500 μm–1 mm diameter microcavities, these lamps produce peak and average intensities at 194 nm greater than those associated with the Hg resonance transition at ∼ 254 nm, despite the factor of $?> > 3 difference between the energies of the 6p 3P1 and 6p 2P1/2 states of neutral Hg and Hg+, respectively. These lamps are unique in the sense that the desired radiating species is an excited ion and the background He gas pressure can reach 1 atm, both of which contribute to a dense glow plasma placing severe demands on E/N, power conditioning, and materials selection. Nevertheless, with proper attention given to design, vacuum processing, and preparation of the lamps, lifetimes above 1500 h have been realized to date. When these lamps drive Jet Propulsion Laboratory Hg+ clocks, the stability floor has been measured to be ∼ 10 −14. The implications of this lamp for gas-phase and solid-state photochemistry are also discussed.

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Pimon, Martin, Andreas Grüneis, Peter Mohn et Thorsten Schumm. « Ab-Initio Study of Calcium Fluoride Doped with Heavy Isotopes ». Crystals 12, n^o 8 (11 août 2022) : 1128. http://dx.doi.org/10.3390/cryst12081128.

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Precision laser spectroscopy of the 229-thorium nuclear isomer transition in a solid-state environment would represent a significant milestone in the field of metrology, opening the door to the realization of a nuclear clock. Working toward this goal, experimental methods require knowledge of various properties of a large band-gap material, such as calcium fluoride doped with specific isotopes of the heavy elements thorium, actinium, cerium, neptunium, and uranium. By accurately determining the atomic structure of potential charge compensation schemes by using a generalized gradient approximation within the ab-initio framework of density functional theory, calculations of electric field gradients on the dopants become accessible, which cause a quadrupole splitting of the nuclear-level structure that can be probed experimentally. Band gaps and absorption coefficients in the range of the 229-thorium nuclear transition are estimated by using the G0W0 method and by solving the Bethe–Salpeter equation.

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Golovizin, A., V. Bushmakin, S. Fedorov, E. Fedorova, D. Tregubov, D. Sukachev, K. Khabarova, V. Sorokin et N. Kolachevsky. « Ultrastable Laser System for Spectroscopy of the 1.14 μm Inner-Shell Clock Transition in Tm and Its Absolute Frequency Measurement ». Journal of Russian Laser Research 40, n^o 6 (novembre 2019) : 540–46. http://dx.doi.org/10.1007/s10946-019-09835-y.

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Lee, Yool, et Alfian Shan Tanggono. « Potential Role of the Circadian Clock in the Regulation of Cancer Stem Cells and Cancer Therapy ». International Journal of Molecular Sciences 23, n^o 22 (16 novembre 2022) : 14181. http://dx.doi.org/10.3390/ijms232214181.

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Circadian rhythms, including sleep/wake cycles as well as hormonal, immune, metabolic, and cell proliferation rhythms, are fundamental biological processes driven by a cellular time-keeping system called the circadian clock. Disruptions in these rhythms due to genetic alterations or irregular lifestyles cause fundamental changes in physiology, from metabolism to cellular proliferation and differentiation, resulting in pathological consequences including cancer. Cancer cells are not uniform and static but exist as different subtypes with phenotypic and functional differences in the tumor microenvironment. At the top of the heterogeneous tumor cell hierarchy, cancer stem cells (CSCs), a self-renewing and multi-potent cancer cell type, are most responsible for tumor recurrence and metastasis, chemoresistance, and mortality. Phenotypically, CSCs are associated with the epithelial–mesenchymal transition (EMT), which confers cancer cells with increased motility and invasion ability that is characteristic of malignant and drug-resistant stem cells. Recently, emerging studies of different cancer types, such as glioblastoma, leukemia, prostate cancer, and breast cancer, suggest that the circadian clock plays an important role in the maintenance of CSC/EMT characteristics. In this review, we describe recent discoveries regarding how tumor intrinsic and extrinsic circadian clock-regulating factors affect CSC evolution, highlighting the possibility of developing novel chronotherapeutic strategies that could be used against CSCs to fight cancer.

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Zhang, Yuan, Aurore Devocelle, Christophe Desterke, Lucas Eduardo Botelho de Souza, Éva Hadadi, Hervé Acloque, Adlen Foudi et al. « BMAL1 Knockdown Leans Epithelial–Mesenchymal Balance toward Epithelial Properties and Decreases the Chemoresistance of Colon Carcinoma Cells ». International Journal of Molecular Sciences 22, n^o 10 (16 mai 2021) : 5247. http://dx.doi.org/10.3390/ijms22105247.

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The circadian clock coordinates biological and physiological functions to day/night cycles. The perturbation of the circadian clock increases cancer risk and affects cancer progression. Here, we studied how BMAL1 knockdown (BMAL1-KD) by shRNA affects the epithelial–mesenchymal transition (EMT), a critical early event in the invasion and metastasis of colorectal carcinoma (CRC). In corresponding to a gene set enrichment analysis, which showed a significant enrichment of EMT and invasive signatures in BMAL1_high CRC patients as compared to BMAL1_low CRC patients, our results revealed that BMAL1 is implicated in keeping the epithelial–mesenchymal equilibrium of CRC cells and influences their capacity of adhesion, migration, invasion, and chemoresistance. Firstly, BMAL1-KD increased the expression of epithelial markers (E-cadherin, CK-20, and EpCAM) but decreased the expression of Twist and mesenchymal markers (N-cadherin and vimentin) in CRC cell lines. Finally, the molecular alterations after BMAL1-KD promoted mesenchymal-to-epithelial transition-like changes mostly appeared in two primary CRC cell lines (i.e., HCT116 and SW480) compared to the metastatic cell line SW620. As a consequence, migration/invasion and drug resistance capacities decreased in HCT116 and SW480 BMAL1-KD cells. Together, BMAL1-KD alerts the delicate equilibrium between epithelial and mesenchymal properties of CRC cell lines, which revealed the crucial role of BMAL1 in EMT-related CRC metastasis and chemoresistance.

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Giri, G. S., O. O. Versolato, L. W. Wansbeek, J. E. van den Berg, D. J. van der Hoek, K. Jungmann, W. L. Kruithof et al. « Precision spectroscopy of trapped radioactive radium ions This paper was presented at the International Conference on Precision Physics of Simple Atomic Systems, held at École de Physique, les Houches, France, 30 May – 4 June, 2010. » Canadian Journal of Physics 89, n^o 1 (janvier 2011) : 69–72. http://dx.doi.org/10.1139/p10-089.

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Atomic parity violation (APV) can be measured in a single Ra+ ion, enabling a precise measurement of the electroweak mixing angle in the Standard Model of particle physics at low momentum transfer. This provides sensitivity to new particles such as extra Z0 bosons or leptoquarks. The Weinberg angle can be measured via a determination of the light shift in the forbidden 72S1/2–62D3/2 transition in a single trapped Ra+. Ultra-narrow transitions in such an ideal system can also be exploited to realize a high stability frequency standard. At the TRIμP facility of KVI, we have succeeded in the production of a series of radioactive short-lived radium isotopes. The radium isotopes produced were stopped and thermalized to Ra+ in a thermal ionizer, mass separated in a Wien filter, cooled in a gas filled radio frequency quadrupole and subsequently trapped as a cloud in a linear Paul trap. Laser spectroscopy in the trapped radium ions has been performed. The results of hyperfine structure, isotope shift, and lifetime measurements are important experimental inputs to test the accuracy of atomic theory, the precision of which is indispensable for extracting the Weinberg angle. These results are also of relevance for a possible atomic clock, based on trapped Ra+.

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Pu, Xiaojun, Lixin Yang, Lina Liu, Xiumei Dong, Silin Chen, Zexi Chen, Gaojing Liu, Yanxia Jia, Wenya Yuan et Li Liu. « Genome-Wide Analysis of the MYB Transcription Factor Superfamily in Physcomitrella patens ». International Journal of Molecular Sciences 21, n^o 3 (1 février 2020) : 975. http://dx.doi.org/10.3390/ijms21030975.

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MYB transcription factors (TFs) are one of the largest TF families in plants to regulate numerous biological processes. However, our knowledge of the MYB family in Physcomitrella patens is limited. We identified 116 MYB genes in the P. patens genome, which were classified into the R2R3-MYB, R1R2R3-MYB, 4R-MYB, and MYB-related subfamilies. Most R2R3 genes contain 3 exons and 2 introns, whereas R1R2R3 MYB genes contain 10 exons and 9 introns. N3R-MYB (novel 3RMYB) and NR-MYBs (novel RMYBs) with complicated gene structures appear to be novel MYB proteins. In addition, we found that the diversity of the MYB domain was mainly contributed by domain shuffling and gene duplication. RNA-seq analysis suggested that MYBs exhibited differential expression to heat and might play important roles in heat stress responses, whereas CCA1-like MYB genes might confer greater flexibility to the circadian clock. Some R2R3-MYB and CCA1-like MYB genes are preferentially expressed in the archegonium and during the transition from the chloronema to caulonema stage, suggesting their roles in development. Compared with that of algae, the numbers of MYBs have significantly increased, thus our study lays the foundation for further exploring the potential roles of MYBs in the transition from aquatic to terrestrial environments.

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He, Xin, Tianyi Wang, Wan Zhu, Yujing Wang et Longfu Zhu. « GhHB12, a HD-ZIP I Transcription Factor, Negatively Regulates the Cotton Resistance to Verticillium dahliae ». International Journal of Molecular Sciences 19, n^o 12 (12 décembre 2018) : 3997. http://dx.doi.org/10.3390/ijms19123997.

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The homeodomain-leucine zipper (HD-ZIP) is a plant-specific transcription factor family that plays important roles in plant developmental processes in response to multiple stressors. We previously isolated a cotton HD-ZIP class I transcription factor gene, GhHB12, which is regulated by the circadian clock and photoperiodism. Furthermore, it regulates cotton architecture, phase transition, and photoperiod sensitivity. Here we report that GhHB12 was induced by methyl jasmonate (MeJA) and Verticillium dahliae infection. Additionally, stress-responsive elements were found in the GhHB12 promoter. Promoter fusion analysis showed that GhHB12 was predominantly expressed in primary roots and that it was induced by mechanical damage. Overexpression of GhHB12 increased susceptibility of the cotton plant to the fungal pathogens Botrytis cinerea and V. dahliae, which was coupled with suppression of the jasmonic acid (JA)-response genes GhJAZ2 and GhPR3. Our results suggest that GhHB12, a cotton stress-responsive HD-ZIP I transcription factor, negatively regulates cotton resistance to V. dahliae by suppressing JA-response genes.

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Mukaiyama, Atsushi, et Shuji Akiyama. « 3P054 Conformational transition of a cyanobacterial clock protein KaiC monitored with fluorescence spectroscopy(01C. Protein : Property,Poster,The 52nd Annual Meeting of the Biophysical Society of Japan(BSJ2014)) ». Seibutsu Butsuri 54, supplement1-2 (2014) : S257. http://dx.doi.org/10.2142/biophys.54.s257_6.

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Khabarova, Ksenia, Denis Kryuchkov, Alexander Borisenko, Ilia Zalivako, Ilya Semerikov, Mikhail Aksenov, Ivan Sherstov, Timur Abbasov, Anton Tausenev et Nikolay Kolachevsky. « Toward a New Generation of Compact Transportable Yb+ Optical Clocks ». Symmetry 14, n^o 10 (20 octobre 2022) : 2213. http://dx.doi.org/10.3390/sym14102213.

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Optical atomic clocks are currently one of the most sensitive tools making it possible to precisely test the fundamental symmetry properties of spacetime and Einstein’s theory of relativity. At the same time, the extremely high stability and accuracy of compact transportable optical clocks open new perspectives in important fields, such as satellite navigation, relativistic geodesy, and the global time and frequency network. Our project aimed to develop a compact transportable optical clock based on a single ytterbium ion. We present the first prototype of the Yb+ clock (298 kg in 1 m3) and present several solutions aimed to improve the clock’s robustness to approach the demands of a space-qualified system. We present spectroscopic studies of a 435.5 nm quadrupole clock transition with Fourier-limited spectra of 25 Hz. The estimated instability of the output frequency at 1 GHz, which was down-converted with an optical frequency comb (OFC), is at the level of 9×10−15/τ, and the long-term instability and inaccuracy are at the level of 5×10−16. As the next steps, we present a new design for the clock laser and the OFC.

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López-Juárez, Zaira M., Laura Aguilar-Henonin et Plinio Guzmán. « The ATXN2 Orthologs CID3 and CID4, Act Redundantly to In-Fluence Developmental Pathways throughout the Life Cycle of Arabidopsis thaliana ». International Journal of Molecular Sciences 22, n^o 6 (17 mars 2021) : 3068. http://dx.doi.org/10.3390/ijms22063068.

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RNA-binding proteins (RBPs) are key elements involved in post-transcriptional regulation. Ataxin-2 (ATXN2) is an evolutionarily conserved RBP protein, whose function has been studied in several model organisms, from Saccharomyces cerevisiae to the Homo sapiens. ATXN2 interacts with poly(A) binding proteins (PABP) and binds to specific sequences at the 3′UTR of target mRNAs to stabilize them. CTC-Interacting Domain3 (CID3) and CID4 are two ATXN2 orthologs present in plant genomes whose function is unknown. In the present study, phenotypical and transcriptome profiling were used to examine the role of CID3 and CID4 in Arabidopsis thaliana. We found that they act redundantly to influence pathways throughout the life cycle. cid3cid4 double mutant showed a delay in flowering time and a reduced rosette size. Transcriptome profiling revealed that key factors that promote floral transition and floral meristem identity were downregulated in cid3cid4 whereas the flowering repressor FLOWERING LOCUS C (FLC) was upregulated. Expression of key factors in the photoperiodic regulation of flowering and circadian clock pathways, were also altered in cid3cid4, as well as the expression of several transcription factors and miRNAs encoding genes involved in leaf growth dynamics. These findings reveal that ATXN2 orthologs may have a role in developmental pathways throughout the life cycle of plants.

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Brenna, Andrea, et Claudio Talora. « WC-1 and the Proximal GATA Sequence Mediate a Cis-/Trans-Acting Repressive Regulation of Light-Dependent Gene Transcription in the Dark ». International Journal of Molecular Sciences 20, n^o 12 (12 juin 2019) : 2854. http://dx.doi.org/10.3390/ijms20122854.

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Light influences a wide range of physiological processes from prokaryotes to mammals. Neurospora crassa represents an important model system used for studying this signal pathway. At molecular levels, the WHITE COLLAR Complex (WCC), a heterodimer formed by WC-1 (the blue light photo-sensor) and WC-2 (the transcriptional activator), is the critical positive regulator of light-dependent gene expression. GATN (N indicates any other nucleotide) repeats are consensus sequences within the promoters of light-dependent genes recognized by the WCC. The distal GATN is also known as C-box since it is involved in the circadian clock. However, we know very little about the role of the proximal GATN, and the molecular mechanism that controls the transcription of light-induced genes during the dark/light transition it is still unclear. Here we showed a first indication that mutagenesis of the proximal GATA sequence within the target promoter of the albino-3 gene or deletion of the WC-1 zinc finger domain led to a rise in expression of light-dependent genes already in the dark, effectively decoupling light stimuli and transcriptional activation. This is the first observation of cis-/trans-acting repressive machinery, which is not consistent with the light-dependent regulatory mechanism observed in the eukaryotic world so far.

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Yudin, V. I., A. V. Taichenachev, M. Yu Basalaev, T. Zanon-Willette, T. E. Mehlstäubler, R. Boudot, J. W. Pollock, M. Shuker, E. A. Donley et J. Kitching. « Combined error signal in Ramsey spectroscopy of clock transitions ». New Journal of Physics 20, n^o 12 (18 décembre 2018) : 123016. http://dx.doi.org/10.1088/1367-2630/aaf47c.

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Najafian, Kaveh, Ziv Meir et Stefan Willitsch. « From megahertz to terahertz qubits encoded in molecular ions : theoretical analysis of dipole-forbidden spectroscopic transitions in N2+ ». Physical Chemistry Chemical Physics 22, n^o 40 (2020) : 23083–98. http://dx.doi.org/10.1039/d0cp03906c.

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Mukaiyama, Atsushi, Yusuke Matsui, Takao Kondo et Shuji Akiyama. « 3P039 Tracking conformational transitions of a circadian clock protein, KaiC using time-resolved spectroscopic techniques(Protein : Structure & ; Function,The 48th Annual Meeting of the Biophysical Society of Japan) ». Seibutsu Butsuri 50, supplement2 (2010) : S151—S152. http://dx.doi.org/10.2142/biophys.50.s151_6.

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Siebert, Ronald, Florian Schlütter, Andreas Winter, Martin Presselt, Helmar Görls, Ulrich Schubert, Benjamin Dietzek et Jürgen Popp. « Ruthenium(II)-bis(4′-(4-ethynylphenyl)-2,2′:6′, 2″-terpyridine) — A versatile synthon in supramolecular chemistry. Synthesis and characterization ». Open Chemistry 9, n^o 6 (1 décembre 2011) : 990–99. http://dx.doi.org/10.2478/s11532-011-0087-6.

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AbstractA homoleptic ethynyl-substituted ruthenium(II)-bisterpyridine complex representing a versatile synthon in supramolecular chemistry was synthesized and analyzed by NMR spectroscopy, mass spectrometry and X-ray diffractometry. Furthermore, its photophysical properties were detailed by UV/Vis absorption, emission and resonance Raman spectroscopy. In order to place the results obtained in the context of the vast family of ruthenium coordination compounds, two structurally related complexes were investigated accordingly. These reference compounds bear either no or an increased chromophore in the 4′-position. The spectroscopic investigations reveal a systematic bathochromic shift of the absorption and emission maximum upon increasing chromophore size. This bathochromic shift of the steady state spectra occurs hand in hand with increasing resonance Raman intensities upon excitation of the metal-to-ligand charge-transfer transition. The latter feature is accompanied by an increased excitation delocalization over the chromophore in the 4′-position of the terpyridine. Thus, the results presented allow for a detailed investigation of the electronic effects of the ethynyl substituent on the metal-to-ligand charge-transfer states in the synthon for click reactions leading to coordination polymers.

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Taichenachev, A. V., V. I. Yudin, C. W. Oates, Z. W. Barber, N. D. Lemke, A. D. Ludlow, U. Sterr, Ch Lisdat et F. Riehle. « Compensation of field-induced frequency shifts in Ramsey spectroscopy of optical clock transitions ». JETP Letters 90, n^o 11 (février 2010) : 713–17. http://dx.doi.org/10.1134/s0021364009230052.

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Akin, T. G., Bryan Hemingway et Steven Peil. « Tellurium spectrometer for ¹S₀–¹P₁ transitions in strontium and other alkaline-earth atoms ». Review of Scientific Instruments 93, n^o 5 (1 mai 2022) : 053002. http://dx.doi.org/10.1063/5.0084122.

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We measure the spectrum of tellurium-130 in the vicinity of the 461 nm [Formula: see text] cycling transition in neutral strontium, a popular element for atomic clocks, quantum information, and quantum-degenerate gases. The lack of hyperfine structure in tellurium results in a spectral density of transitions nearly 50 times lower than that available in iodine, making use of tellurium as a laser-frequency reference challenging. By frequency-offset locking two lasers, we generate the large frequency shifts required to span the difference between a tellurium line and the [Formula: see text] resonance in strontium or other alkaline-earth atoms. The resulting laser architecture is long-term frequency stable, widely tunable, and optimizes the available laser power. The versatility of the system is demonstrated by using it to quickly switch between any strontium isotope in a magneto-optical trap and by adapting it to spectroscopy on a thermal beam with a different alkaline-earth atom.

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Novotny, C., B. Bernhardt, D. Bing, G. Ewald, C. Geppert, G. Gwinner, G. Huber et al. « Towards a precision test of time dilation at high velocityThis paper was presented at the International Conference on Precision Physics of Simple Atomic Systems, held at University of Windsor, Windsor, Ontario, Canada on 21–26 July 2008. » Canadian Journal of Physics 87, n^o 7 (juillet 2009) : 749–56. http://dx.doi.org/10.1139/p08-149.

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We report on first measurements towards an Ives–Stilwell test of time dilation at velocities around 0.3c. In Ives–Stilwell type experiments, fast atomic ions containing a well-known transition are used as moving clocks, and time dilation as well as the velocity can be derived from the simultaneous laser-spectroscopic measurements of the Doppler shifts with and against the direction of motion. To accurately measure these Doppler shifts, the Doppler broadening caused by the ions velocity distribution needs to be overcome. We performed first feasibility studies for laser spectroscopy on 7Li+ ions in the 2s3S21 metastable ground state at the Gesellschaft für Schwerinonenforschung (GSI) in Darmstadt. The ions were stored in the Experimental Storage Ring (ESR) at a velocity of 0.338c, and optical–optical double-resonance spectroscopy on a closed Λ-type three level system was performed with two lasers propagating antiparallel to the ions motion. We found that Doppler shift measurements on a narrow subclass of the ions velocity distribution with sufficient signal-to-noise ratio are possible if the ion beam is electron-cooled and bunched. Together with the control of systematic error sources developed in our previous experiments on slower beams, the ESR experiment promises an improvement of previously achieved sensitivities to time dilation by about an order of magnitude.

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Yu, Yang, Yuzhen Zhao, Yongsheng Mi, Yang Zhao, Zhun Guo, Huimin Zhang, Dong Wang et Zongcheng Miao. « Exploration of Optical Properties of Novel Pyrene Derivatives Modified by Click Functionalization ». Crystals 12, n^o 9 (14 septembre 2022) : 1295. http://dx.doi.org/10.3390/cryst12091295.

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A simple synthetic method was designed, in which the Sonogashira coupling reaction and [2+2] cycloaddition click reaction with high yield were performed on 1-bromopyrene to obtain several novel pyrene derivatives. The structure of each sample was characterized by Nuclear Magnetic Resonance (NMR), Mass Spectrometry (MS), Fourier transform infrared (FTIR) and elemental analysis. The characterization of the products by Ultraviolet-visible (UV-vis) and Photoluminescence (PL) spectroscopy proves that the addition of click groups has an important effect on the optoelectronic properties of pyrene derivatives. The Z-scan technique was used to test the third-order nonlinear optical (NLO) properties of the samples, and it could be found that the NLO properties of the products were improved and the transition of saturable absorption and reverse saturable absorption occurred with the addition of click reagent. These factors indicate that the click-modified pyrene derivatives have potential applications in areas such as optical limiting.

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Hosseinnejad, Tayebeh, Fatemeh Ebrahimpour-Malmir et Bahareh Fattahi. « Computational investigations of click-derived 1,2,3-triazoles as keystone ligands for complexation with transition metals : a review ». RSC Advances 8, n^o 22 (2018) : 12232–59. http://dx.doi.org/10.1039/c8ra00283e.

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1,2,3-Triazole based ligands and their complexes with transition metals are used in pharmaceuticals and catalysis. Here we assess recent computational research on the structural, electronic and spectroscopic properties of these complexes.

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Zhang, Wenzheng, Ning Jiang et Tingting Zhang. « Self-plasticization of neoprene rubber via click chemistry from environmentally sustainable cardanol ». Journal of Elastomers & ; Plastics 52, n^o 6 (26 août 2019) : 483–94. http://dx.doi.org/10.1177/0095244319869768.

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The sustainable biomass cardanol grafting onto neoprene (CR) rubber was carried out successfully at room temperature by covalently binding to CR via click chemistry to realize the internal plasticization of CR rubber. The structure of the synthesized product was characterized by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance, and differential scanning calorimetry and thermogravimetric analysis demonstrate a lowering of the glass transition temperature of the CR-propargyl ether cardanol as compared to CR. This confirms the plasticization effect of the cardanol when grafted onto CR. The cardanol as an internal plasticizer also has a good thermal stability and almost near-zero migration.

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Chang, Pengyuan, Hangbo Shi, Jianxiang Miao, Tiantian Shi, Duo Pan, Bin Luo, Hong Guo et Jingbiao Chen. « Frequency-stabilized Faraday laser with 10⁻¹⁴ short-term instability for atomic clocks ». Applied Physics Letters 120, n^o 14 (4 avril 2022) : 141102. http://dx.doi.org/10.1063/5.0083390.

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In this Letter, stabilizing a Faraday laser frequency to the atomic transition is proposed and experimentally demonstrated, where the Faraday laser can work at single- or dual-frequency modes. High-resolution spectroscopy of a cesium atom induced by a Faraday laser is obtained. By stabilizing a Faraday laser with atomic spectroscopy, the frequency fluctuations of the Faraday laser are suppressed without the need of a high-cost Pound–Drever–Hall system. The fractional frequency Allan deviation of the residual error signal is 3 × 10[Formula: see text] at the single-frequency mode. While at the dual-frequency mode, the linewidth of the beat-note spectra between the two modes of the Faraday laser after locking is narrowed to be 85 Hz, which is an order of magnitude better than the free-running linewidth. It can be used for microwave atomic clocks and may have the potential to be used in the application of optical microwave generation when the performance is further improved.

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Zhao, Yuzhen, Zhenhua Li, Qing Li, Yang Zhao, Ruijuan Yao, Cheng Ma, Yongming Zhang et Dong Wang. « Optical Properties of New Third-Order Nonlinear Materials Modified by Click Chemistry ». Molecules 27, n^o 15 (6 août 2022) : 5006. http://dx.doi.org/10.3390/molecules27155006.

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A high-yielding click reaction was used to synthesize a series of highly conjugated, symmetrical, as well as asymmetrical compounds with a benzene core. Cyclic voltammetry and ultraviolet/visible absorption spectroscopy were carried out, and proved that the side groups of the benzene derivatives played an important role in the energy gaps, and affected the third-order non-linear optical response. The maximum absorption wavelength of the series of benzene derivatives showed an obvious red-shift. Moreover, the addition of resilient electron-withdrawing groups significantly narrowed the energy levels as compared with precursors. The third-order nonlinear properties of this benzene derivative were tested by the Z-scan technique. The expected properties of this series of molecules were obtained, and it was found that the series of molecules undergoes a transition from reverse saturable absorption to saturable absorption, which has certain reference significance for a nonlinear optical field.

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Nomura, Junia, Tomohiko Momma, Yuki Kojima, Yusuke Hisai, Takumi Kobayashi, Daisuke Akamatsu et Feng-Lei Hong. « Direct loading of Yb atoms into a 3D magneto-optical trap from a dispenser atomic source ». AIP Advances 13, n^o 2 (1 février 2023) : 025361. http://dx.doi.org/10.1063/5.0140774.

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The realization of cold atoms using a compact and low-power-consumption experimental setup is indispensable for cold atom experiments, including optical clocks and quantum simulations. We demonstrate the direct loading of Yb atoms into a 3D magneto-optical trap (MOT) from a dispenser atomic source without using a Zeeman slower. The power consumption of the dispenser was ∼3 W. Spectroscopy of the atomic beam from the dispenser on the 6s2 1S0–6s6p 1P1 Yb transition at 399 nm shows that the flux of the atomic beam reaches 1.4 × 1013 s−1 cm−2. We can load up to 4.1 × 107 atoms into the MOT with slowing and trapping laser powers of 20.3 and 35.0 mW, respectively. The realized cold atom system is reliable and can be adapted for experiments on alkaline earth and other alkaline earth-like atoms.

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Głowacki, P., D. Stefańska, J. Ruczkowski et M. Elantkowska. « Estimation of radiative parameters for atomic manganese from the point of view of possible clock transitions and laser cooling schemes ». Journal of Quantitative Spectroscopy and Radiative Transfer 276 (décembre 2021) : 107898. http://dx.doi.org/10.1016/j.jqsrt.2021.107898.

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Liu, Xin, Xiao-Peng Zhou, Wei-Qiang Wen, Qi-Feng Lu, Cheng-Long Yan, Guo-Qin Xu, Jun Xiao et al. « Spectral calibration for electron beam ion trap and precision measurement of M1 transition wavelength in Ar13+ ; ». Acta Physica Sinica 71, n^o 3 (2022) : 033201. http://dx.doi.org/10.7498/aps.71.20211663.

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The precise measurement of the transition wavelength of the fine structure of highly charged ions can not only test basic physical theories including the quantum electrodynamics effect and the electronic correlation effect but also provide key atomic data for astrophysics and fusion plasma physics. Furthermore, highly charged ions are considered as a potential candidate for optical clocks with extremely ultra-high precision. In this work, a new spectral calibration system is built in a high-temperature superconducting electron beam ion trap (SH-HtscEBIT) in the Institute of Modern Physics, Fudan University, and the uncertainty of its spectrum wavelength measurement is evaluated by combining internal and external calibrations. The minimum wavelength uncertainty caused by the new spectral calibration system in the visible light band reaches 0.002 nm. On this basis, the precise measurement of 2s22p 2P1/2－2P3/2 M1 transition wavelength for boron-like Ar13+ is performed at the SH-HtscEBIT by utilizing the new calibration system. The experimentally measured transition wavelength is (441.2567 ± 0.0026) nm. It is currently the experimental result with the highest measurement accuracy of spectroscopy of highly charged ions at the SH-HtscEBIT, which lays the foundation for the precise measurement of the hyperfine splitting and isotope shift of highly charged ions in the future experiments.

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Musfeldt, Janice L., Zhenxian Liu, Diego López-Alcalá, Yan Duan, Alejandro Gaita-Ariño, José J. Baldoví et Eugenio Coronado. « Vibronic Relaxation Pathways in Molecular Spin Qubit Na9[Ho(W5O18)2]·35H2O under Pressure ». Magnetochemistry 9, n^o 2 (9 février 2023) : 53. http://dx.doi.org/10.3390/magnetochemistry9020053.

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In order to explore how spectral sparsity and vibronic decoherence pathways can be controlled in a model qubit system with atomic clock transitions, we combined diamond anvil cell techniques with synchrotron-based far infrared spectroscopy and first-principles calculations to reveal the vibrational response of Na9[Ho(W5O18)2]·35H2O under compression. Because the hole in the phonon density of states acts to reduce the overlap between the phonons and f manifold excitations in this system, we postulated that pressure might move the HoO4 rocking, bending, and asymmetric stretching modes that couple with the MJ = ±5, ±2, and ±7 levels out of resonance, reducing their interactions and minimizing decoherence processes, while a potentially beneficial strategy for some molecular qubits, pressure slightly hardens the phonons in Na9[Ho(W5O18)2]·35H2O and systematically fills in the transparency window in the phonon response. The net result is that the vibrational spectrum becomes less sparse and the overlap with the various MJ levels of the Ho3+ ion actually increases. These findings suggest that negative pressure, achieved using chemical means or elongational strain, could further open the transparency window in this rare earth-containing spin qubit system, thus paving the way for the use of device surfaces and interface elongational/compressive strains to better manage decoherence pathways.

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Abularrage, Nile S., Brian J. Levandowski et Ronald T. Raines. « Synthesis and Diels–Alder Reactivity of 4-Fluoro-4-Methyl-4H-Pyrazoles ». International Journal of Molecular Sciences 21, n^o 11 (31 mai 2020) : 3964. http://dx.doi.org/10.3390/ijms21113964.

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4H-Pyrazoles are emerging scaffolds for “click” chemistry. Late-stage fluorination with Selectfluor® is found to provide a reliable route to 4-fluoro-4-methyl-4H-pyrazoles. 4-Fluoro-4-methyl-3,5-diphenyl-4H-pyrazole (MFP) manifested 7-fold lower Diels–Alder reactivity than did 4,4-difluoro-3,5-diphenyl-4H-pyrazole (DFP), but higher stability in the presence of biological nucleophiles. Calculations indicate that a large decrease in the hyperconjugative antiaromaticity in MFP relative to DFP does not lead to a large loss in Diels–Alder reactivity because the ground-state structure of MFP avoids hyperconjugative antiaromaticity by distorting into an envelope-like conformation like that in the Diels–Alder transition state. This predistortion enhances the reactivity of MFP and offsets the decrease in reactivity from the diminished hyperconjugative antiaromaticity.

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Dyakin, Victor V., Nuka V. Dyakina-Fagnano, Laura B. Mcintire et Vladimir N. Uversky. « Fundamental Clock of Biological Aging : Convergence of Molecular, Neurodegenerative, Cognitive and Psychiatric Pathways : Non-Equilibrium Thermodynamics Meet Psychology ». International Journal of Molecular Sciences 23, n^o 1 (28 décembre 2021) : 285. http://dx.doi.org/10.3390/ijms23010285.

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In humans, age-associated degrading changes, widely observed in molecular and cellular processes underly the time-dependent decline in spatial navigation, time perception, cognitive and psychological abilities, and memory. Cross-talk of biological, cognitive, and psychological clocks provides an integrative contribution to healthy and advanced aging. At the molecular level, genome, proteome, and lipidome instability are widely recognized as the primary causal factors in aging. We narrow attention to the roles of protein aging linked to prevalent amino acids chirality, enzymatic and spontaneous (non-enzymatic) post-translational modifications (PTMs SP), and non-equilibrium phase transitions. The homochirality of protein synthesis, resulting in the steady-state non-equilibrium condition of protein structure, makes them prone to multiple types of enzymatic and spontaneous PTMs, including racemization and isomerization. Spontaneous racemization leads to the loss of the balanced prevalent chirality. Advanced biological aging related to irreversible PTMs SP has been associated with the nontrivial interplay between somatic (molecular aging) and mental (psychological aging) health conditions. Through stress response systems (SRS), the environmental and psychological stressors contribute to the age-associated “collapse” of protein homochirality. The role of prevalent protein chirality and entropy of protein folding in biological aging is mainly overlooked. In a more generalized context, the time-dependent shift from enzymatic to the non-enzymatic transformation of biochirality might represent an important and yet underappreciated hallmark of aging. We provide the experimental arguments in support of the racemization theory of aging.

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Andre, E., E. Yaniz-Galende, C. Hamilton, G. J. Dusting, N. Hellen, CE Poulet, M. Diez Cunado et al. « Poster session 1Cell growth, differentiation and stem cells - Heart72Understanding the metabolism of cardiac progenitor cells : a first step towards controlling their proliferation and differentiation?73Expression of pw1/peg3 identifies a new cardiac adult stem cell population involved in post-myocardial infarction remodeling74Long-term stimulation of iPS-derived cardiomyocytes using optogenetic techniques to promote phenotypic changes in E-C coupling75Benefits of electrical stimulation on differentiation and maturation of cardiomyocytes from human induced pluripotent stem cells76Constitutive beta-adrenoceptor-mediated cAMP production controls spontaneous automaticity of human induced pluripotent stem cell-derived cardiomyocytes77Formation and stability of T-tubules in cardiomyocytes78Identification of miRNAs promoting human cardiomyocyte proliferation by regulating Hippo pathway79A direct comparison of foetal to adult epicardial cell activation reveals distinct differences relevant for the post-injury response80Role of neuropilins in zebrafish heart regeneration81Highly efficient immunomagnetic purification of cardiomyocytes derived from human pluripotent stem cells82Cardiac progenitor cells posses a molecular circadian clock and display large 24-hour oscillations in proliferation and stress tolerance83Influence of sirolimus and everolimus on bone marrow-derived mesenchymal stem cell biology84Endoglin is important for epicardial behaviour following cardiac injuryCell death and apoptosis - Heart87Ultrastructural alterations reflecting Ca2+ handling and cell-to-cell coupling disorders precede occurrence of severe arrhythmias in intact animal heart88Urocortin-1 promotes cardioprotection through ERK1/2 and EPAC pathways : role in apoptosis and necrosis89Expression p38 MAPK and Cas-3 in myocardium LV of rats with experimental heart failure at melatonin and enalapril introductionTranscriptional control and RNA species - Heart92Accumulation of beta-amyloid 1-40 in HF patients : the role of lncRNA BACE1-AS93Role of miR-182 in zebrafish and mouse models of Holt-Oram syndrome94Mir-27 distinctly regulates muscle-enriched transcription factors and growth factors in cardiac and skeletal muscle cells95AF risk factors impair PITX2 expression leading to Wnt-microRNA-ion channel remodelingCytokines and cellular inflammation - Heart98Post-infarct survival depends on the interplay of monocytes, neutrophils and interferon gamma in a mouse model of myocardial Infarction99Inflammatory cd11b/c cells play a protective role in compensated cardiac hypertrophy by promoting an orai3-related pro-survival signal100Anti-inflammatory effects of endothelin receptor blockade in the atrial tissue of spontaneously hypertensive rats101Mesenchymal stromal cells reduce NLRP3 inflammasome activity in Coxsackievirus B3-induced myocarditis102Mesenchymal stromal cells modulate monocytes trafficking in Coxsackievirus B3-induced myocarditis103The impact of regulatory T lymphocytes on long-term mortality in patients with chronic heart failure104Temporal dynamics of dendritic cells after ST-elevation myocardial infarction relate with improvement of myocardial functionGrowth factors and neurohormones - Heart107Preconditioning of hypertrophied heart : miR-1 and IGF-1 crosstalk108Modulation of catecholamine secretion from human adrenal chromaffin cells by manipulation of G protein-coupled receptor kinase-2 activity109Evaluation of cyclic adenosin-3,5- monophosphate and neurohormones in patients with chronic heart failureNitric oxide and reactive oxygen species - Heart112Hydrogen sulfide donor inhibits oxidative and nitrosative stress, cardiohemodynamics disturbances and restores cNOS coupling in old rats113Role and mechanisms of action of aldehydes produced by monoamine oxidase A in cardiomyocyte death and heart failure114Exercise training has contrasting effects in myocardial infarction and pressure-overload due to different endothelial nitric oxide synthase regulation115S-Nitroso Human Serum Albumin dose-dependently leads to vasodilation and alters reactive hyperaemia in coronary arteries of an isolated mouse heart model116Modulating endothelial nitric oxide synthase with folic acid attenuates doxorubicin-induced cardiomyopathy119Effects of long-term very high intensity exercise on aortic structure and function in an animal model120Electron paramagnetic resonance spectroscopy quantification of nitrosylated hemoglobin (HbNO) as an index of vascular nitric oxide bioavailability in vivo121Deletion of repressor activator protein 1 impairs acetylcholine-induced relaxation due to production of reactive oxygen speciesExtracellular matrix and fibrosis - Heart124MicroRNA-19b is associated with myocardial collagen cross-linking in patients with severe aortic stenosis. Potential usefulness as a circulating biomarker125A new ex vivo model to study cardiac fibrosis126Heterogeneity of fibrosis and fibroblast differentiation in the left ventricle after myocardial infarction127Effect of carbohydrate metabolism degree compensation to the level of galectin-3 changes in hypertensive patients with chronic heart failure and type 2 diabetes mellitus128Statin paradox in association with calcification of bicuspid aortic valve interstitial cells129Cardiac function remains impaired despite reversible cardiac fibrosis after healed experimental viral myocarditisIon channels, ion exchangers and cellular electrophysiology - Heart132Identifying a novel role for PMCA1 (Atp2b1) in heart rhythm instability133Mutations of the caveolin-3 gene as a predisposing factor for cardiac arrhythmias134The human sinoatrial node action potential : time for a computational model135iPSC-derived cardiomyocytes as a model to dissect ion current alterations of genetic atrial fibrillation136Postextrasystolic potentiation in healthy and diseased hearts : effects of the site of origin and coupling interval of the preceding extrasystole137Absence of Nav1.8-based (late) sodium current in rabbit cardiomyocytes and human iPSC-CMs138hiPSC-derived cardiomyocytes from Brugada Syndrome patients without identified mutations do not exhibit cellular electrophysiological abnormalitiesMicrocirculation141Atherogenic indices, collagen type IV turnover and the development of microvascular complications- study in diabetics with arterial hypertension142Changes in the microvasculature and blood viscosity in women with rheumatoid arthritis, hypercholesterolemia and hypertensionAtherosclerosis145Shear stress regulates endothelial autophagy : consequences on endothelial senescence and atherogenesis146Obstructive sleep apnea causes aortic remodeling in a chronic murine model147Aortic perivascular adipose tissue displays an aged phenotype in early and late atherosclerosis in ApoE-/- mice148A systematic evaluation of the cellular innate immune response during the process of human atherosclerosis149Inhibition of Coagulation factor Xa increases plaque stability and attenuates the onset and progression of atherosclerotic plaque in apolipoprotein e-deficient mice150Regulatory CD4+ T cells from patients with atherosclerosis display pro-inflammatory skewing and enhanced suppression function151Hypoxia-inducible factor (HIF)-1alpha regulates macrophage energy metabolism by mediating miRNAs152Extracellular S100A4 is a key player of smooth muscle cell phenotypic transition : implications in atherosclerosis153Microparticles of healthy origins improve atherosclerosis-associated endothelial progenitor cell dysfunction via microRNA transfer154Arterial remodeling and metabolism impairment in early atherosclerosis155Role of pannexin1 in atherosclerotic plaque formationCalcium fluxes and excitation-contraction coupling158Amphiphysin II induces tubule formation in cardiac cells159Interleukin 1 beta regulation of connexin 43 in cardiac fibroblasts and the effects of adult cardiac myocyte:fibroblast co-culture on myocyte contraction160T-tubular electrical defects contribute to blunted beta-adrenergic response in heart failure161Beat-to-beat variability of intracellular Ca2+ dynamics of Purkinje cells in the infarct border zone of the mouse heart revealed by rapid-scanning confocal microscopy162The efficacy of late sodium current blockers in hypertrophic cardiomyopathy is dependent on genotype : a study on transgenic mouse models with different mutations163Synthesis of cADPR and NAADP by intracellular CD38 in heart : role in inotropic and arrhythmogenic effects of beta-adrenoceptor signalingContractile apparatus166Towards an engineered heart tissue model of HCM using hiPSC expressing the ACTC E99K mutation167Diastolic mechanical load delays structural and functional deterioration of ultrathin adult heart slices in culture168Structural investigation of the cardiac troponin complex by molecular dynamics169Exercise training restores myocardial and oxidative skeletal muscle function from myocardial infarction heart failure ratsOxygen sensing, ischaemia and reperfusion172A novel antibody specific to full-length stromal derived factor-1 alpha reveals that remote conditioning induces its cleavage by endothelial dipeptidyl peptidase 4173Attenuation of myocardial and vascular arginase activity by vagal nerve stimulation via a mechanism involving alpha-7 nicotinic receptor during cardiac ischemia and reperfusion174Novel nanoparticle-mediated medicine for myocardial ischemia-reperfusion injury simultaneously targeting mitochondrial injury and myocardial inflammation175Acetylcholine plays a key role in myocardial ischaemic preconditioning via recruitment of intrinsic cardiac ganglia176The role of nitric oxide and VEGFR-2 signaling in post ischemic revascularization and muscle recovery in aged hypercholesterolemic mice177Efficacy of ischemic preconditioning to protect the human myocardium : the role of clinical conditions and treatmentsCardiomyopathies and fibrosis180Plakophilin-2 haploinsufficiency leads to impaired canonical Wnt signaling in ARVC patient181Improved technique for customized, easier, safer and more reliable transverse aortic arch banding and debanding in mice as a model of pressure overload hypertrophy182Late sodium current inhibitors for the treatment of inducible obstruction and diastolic dysfunction in hypertrophic cardiomyopathy : a study on human myocardium183Angiotensin II receptor antagonist fimasartan has protective role of left ventricular fibrosis and remodeling in the rat ischemic heart184Role of High-Mobility Group Box 1 (HMGB1) redox state on cardiac fibroblasts activities and heart function after myocardial infarction185Atrial remodeling in hypertrophic cardiomyopathy : insights from mouse models carrying different mutations in cTnT186Electrophysiological abnormalities in ventricular cardiomyocytes from a Maine Coon cat with hypertrophic cardiomyopathy : effects of ranolazine187ZBTB17 is a novel cardiomyopathy candidate gene and regulates autophagy in the heart188Inhibition of SRSF4 in cardiomyocytes induces left ventricular hypertrophy189Molecular characterization of a novel cardiomyopathy related desmin frame shift mutation190Autonomic characterisation of electro-mechanical remodeling in an in-vitro leporine model of heart failure191Modulation of Ca2+-regulatory function by three novel mutations in TNNI3 associated with severe infant restrictive cardiomyopathyAging194The aging impact on cardiac mesenchymal like stromal cells (S+P+)195Reversal of premature aging markers after bariatric surgery196Sex-associated differences in vascular remodeling during aging : role of renin-angiotensin system197Role of the receptor for advanced glycation end-products (RAGE) in age dependent left ventricle dysfunctionsGenetics and epigenetics200hsa-miR-21-5p as a key factor in aortic remodeling during aneurysm formation201Co-inheritance of mutations associated with arrhythmogenic and hypertrophic cardiomyopathy in two Italian families202Lamin a/c hot spot codon 190 : form various amino acid substitutions to clinical effects203Treatment with aspirin and atorvastatin attenuate cardiac injury induced by rat chest irradiation : Implication of myocardial miR-1, miR-21, connexin-43 and PKCGenomics, proteomics, metabolomics, lipidomics and glycomics206Differential phosphorylation of desmin at serines 27 and 31 drives the accumulation of preamyloid oligomers in heart failure207Potential role of kinase Akt2 in the reduced recovery of type 2 diabetic hearts subjected to ischemia / reperfusion injury208A proteomics comparison of extracellular matrix remodelling in porcine coronary arteries upon stent implantationMetabolism, diabetes mellitus and obesity211Targeting grk2 as therapeutic strategy for cancer associated to diabetes212Effects of salbutamol on large arterial stiffness in patients with metabolic syndrome213Circulating microRNA-1 and microRNA-133a : potential biomarkers of myocardial steatosis in type 2 diabetes mellitus214Anti-inflammatory nutrigenomic effects of hydroxytyrosol in human adipocytes - protective mechanisms of mediterranean diets in obesity-related inflammation215Alterations in the metal content of different cardiac regions within a rat model of diabetic cardiomyopathyTissue engineering218A novel conductive patch for application in cardiac tissue engineering219Establishment of a simplified and improved workflow from neonatal heart dissociation to cardiomyocyte purification and characterization220Effects of flexible substrate on cardiomyocytes cell culture221Mechanical stretching on cardiac adipose progenitors upregulates sarcomere-related genes ». Cardiovascular Research 111, suppl 1 (1 juillet 2016) : S16—S42. http://dx.doi.org/10.1093/cvr/cvw135.

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Kaewuam, R., T. R. Tan, K. J. Arnold et M. D. Barrett. « Spectroscopy of the S01−D21 clock transition in Lu+176 ». Physical Review A 99, n^o 2 (25 février 2019). http://dx.doi.org/10.1103/physreva.99.022514.

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Dareau, A., M. Scholl, Q. Beaufils, D. Döring, J. Beugnon et F. Gerbier. « Doppler spectroscopy of an ytterbium Bose-Einstein condensate on the clock transition ». Physical Review A 91, n^o 2 (24 février 2015). http://dx.doi.org/10.1103/physreva.91.023626.

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von der Wense, Lars, et Benedict Seiferle. « The $$^{229}$$Th isomer : prospects for a nuclear optical clock ». European Physical Journal A 56, n^o 11 (novembre 2020). http://dx.doi.org/10.1140/epja/s10050-020-00263-0.

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AbstractThe proposal for the development of a nuclear optical clock has triggered a multitude of experimental and theoretical studies. In particular the prediction of an unprecedented systematic frequency uncertainty of about $$10^{-19}$$ 10 - 19 has rendered a nuclear clock an interesting tool for many applications, potentially even for a re-definition of the second. The focus of the corresponding research is a nuclear transition of the $$^{229}$$ 229 Th nucleus, which possesses a uniquely low nuclear excitation energy of only $$8.12\pm 0.11$$ 8.12 ± 0.11 eV ($$152.7\pm 2.1$$ 152.7 ± 2.1 nm). This energy is sufficiently low to allow for nuclear laser spectroscopy, an inherent requirement for a nuclear clock. Recently, some significant progress toward the development of a nuclear frequency standard has been made and by today there is no doubt that a nuclear clock will become reality, most likely not even in the too far future. Here we present a comprehensive review of the current status of nuclear clock development with the objective of providing a rather complete list of literature related to the topic, which could serve as a reference for future investigations.

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Głowacki, P., D. Stefańska, J. Ruczkowski et M. Elantkowska. « Proposed clock transition in atomic chromium and the possible detection schemes ». Journal of Quantitative Spectroscopy and Radiative Transfer, juillet 2022, 108331. http://dx.doi.org/10.1016/j.jqsrt.2022.108331.

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Articles de revues sur le sujet « Clock transition spectroscopy »

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