Article
Chemistry, Physical
J. Ree, Y. H. Kim, H. K. Shin
Summary: In this study, the redistribution of vibrational energy in the adenine-uracil base pair was investigated when interacting with a H2O molecule excited in an overtone-bending vibration. The energy transfer and redistribution processes were found to occur rapidly, with most intermolecular hydrogen bonds weakened but unbroken during the redistribution period. The efficiency of the energy redistribution was due to near-resonance between coupled vibrations.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Biochemistry & Molecular Biology
Poul Erik Hansen, Mohammad Vakili, Fadhil S. Kamounah, Jens Spanget-Larsen
Summary: The vibrational NH stretching transitions in secondary amines with intramolecular NH···O hydrogen bonds were studied using experimental and theoretical methods, revealing a good correlation between observed wavenumbers and calculated harmonic values. The linear relationship between anharmonic VPT2 wavenumbers and corresponding harmonic values was found, providing correlation equations for predicting NH stretching bands based on standard B3LYP/6-311++G(d,p) and B3LYP/6-31G(d) harmonic analyses.
Article
Chemistry, Physical
J. Ree, K. C. Ko, Y. H. Kim, H. K. Shin
Summary: Selective excitation of o-toluidine and α-methylbenzylamine was studied to investigate the intramolecular energy flow. The stretching mode of the para-CH bond was initially excited and interacted with an argon atom to induce energy flow. The dominant relaxation pathway was through the NH stretching mode, which was strongly enhanced by the methyl-NH interaction. The energy flow characteristics were similar in both molecules, with o-toluidine exhibiting more effective energy flow due to the perturbation caused by the methyl group bonded to the benzene ring.
JOURNAL OF PHYSICAL CHEMISTRY B
(2023)
Article
Chemistry, Analytical
Naoto Imagawa, Yuji Mizuno, Ibuki Nakata, Natsuna Komoto, Hanako Sakebayashi, Hayato Shigetoh, Takayuki Kodama, Junya Miyazaki
Summary: This study investigates the relationship between stretching intensity and relaxation effects, focusing on brainwaves and autonomic nervous system (ANS) activity. Results demonstrate no significant differences between ANS and brain activity based on stretching intensity, but sympathetic nervous activity is higher during rest phases than in the stretch phases, and alpha and beta waves show higher activity during rest phases than in the stretch phases.
Article
Sport Sciences
Kensuke Oba, Mina Samukawa, Kentaro Nakamura, Kentaro Mikami, Yuki Suzumori, Yuko Ishida, Nathalie Keeler, Hiroshi Saitoh, Masanori Yamanaka, Harukazu Tohyama
Summary: The study investigated the effects of constant torque stretching (CTS) at different intensities on flexibility and mechanical properties of plantar flexors. Results showed that maximal intensity stretching (100% CTS) significantly increased maximal ROM and decreased MTU stiffness, while submaximal intensity stretching (50% or 75%) did not show significant differences compared to the control condition. Findings suggest that maximal intensity stretching is the most effective approach for improving flexibility and MTU stiffness with CTS.
JOURNAL OF STRENGTH AND CONDITIONING RESEARCH
(2021)
Article
Chemistry, Physical
Jimmy Murillo-Gelvez, Olga Dmitrenko, Tifany L. Torralba-Sanchez, Paul G. Tratnyek, Dominic M. Di Toro
Summary: In order to understand the environmental fate of PFAS, it is important to know their physicochemical properties. This study developed QSARs by correlating vibrational frequencies and infrared intensities with pK(a) values. The results showed that the length of the perfluoroalkyl chain has minimal effect on pK(a) values.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Aleksandr A. Balashov, Katarzyna Bielska, Gang Li, Aleksandra A. Kyuberis, Szymon Wojtewicz, Jolanta Domyslawska, Roman Ciurylo, Nikolay F. Zobov, Daniel Lisak, Jonathan Tennyson, Oleg L. Polyansky
Summary: The intensities of 14 lines in the sixth overtone (7-0) band of 12CO are measured using a frequency-stabilized cavity ring-down spectrometer in the visible range. This is the first observation of such a high and weak overtone spectrum of the CO molecule. A theoretical model is constructed and tested based on accurate ab initio dipole moment and semi-empirical potential energy curves. Although the high overtone transitions present a challenge due to their weak lines, agreement between theory and experiment is achieved within a few percent of experimental uncertainty, after addressing issues with the stability of the Davidson correction to the multi-reference configuration interaction calculations.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Jimmy Murillo-Gelvez, Olga Dmitrenko, Tifany L. Torralba-Sanchez, Paul G. Tratnyek, Dominic M. Di Toro
Summary: In order to understand and simulate the environmental fate of PFAS, it is important to have knowledge about the key physicochemical properties (PChPs), such as pK(a). However, there is a lack of reliable measured PChPs for PFAS. This study developed quantitative structure-activity relationships (QSARs) by correlating calculated vibrational frequencies (VF) and infrared intensities (IRInt) to pK(a) values of different subclasses of PFAS. The QSARs were able to predict pK(a) values for each subclass within a 0.5 pK(a) unit range of experimental values.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Organic
Li Wang, Zhi Zhou, Jian-Ping Huang, Liang Zhang, Xiaotao Tuo, Zhiyin Yu, Sheng-Xiong Huang, Yang Liu, Jing Yang
Summary: Strepyrrolins A-E, isolated from an endophytic Streptomyces sp. KIB 015, are five pyrrole-sesquiterpene hybrids with a 1,2,3-trisubstituted cyclopentanol terpene end-group. Their structures were determined through X-ray diffraction and spectroscopic methods. Feeding experiments revealed that the terpene moiety in strepyrrolins is biosynthesized via the MEP pathway, and the pyrrole ring is formed using free ammonia and two C3 units as potential substrates. Compound 3 exhibited immunosuppressive activity, inhibiting T cell proliferation and inducing cell cycle arrest in the G(0)/G(1) phase.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Physiology
Masatoshi Nakamura, Shigeru Sato, Yuta Murakami, Ryosuke Kiyono, Kaoru Yahata, Futaba Sanuki, Riku Yoshida, Taizan Fukaya, Kosuke Takeuchi
Summary: The study found that conducting static stretching interventions at intensities of 100% and 120% can increase knee flexion range of motion and decrease muscle shear elastic modulus, which could be beneficial in preventing quadriceps muscle strain, especially the rectus femoris.
FRONTIERS IN PHYSIOLOGY
(2021)
Article
Chemistry, Organic
Mohamad Zarif Mohd Zubir, Nurul Fajry Maulida, Yoshihiro Abe, Yuta Nakamura, Mariam Abdelrasoul, Tohru Taniguchi, Kenji Monde
Summary: This study demonstrates that the introduction of a suitable VCD chromophore can be used to extract local stereochemical information and enable stereochemical assignment of the C-1 position of various sugars.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2022)
Article
Optics
Konstantin Kazakov, Andrey A. Vigasin
Summary: The theoretical approach developed for Herman-Wallis factors in a linear molecule effectively estimates line intensities in CO2 molecule without complex algebra. Additionally, an analog of Herman-Wallis factors is introduced for dipole-forbidden bands relevant to collision-induced absorption in CO2. The rovibrational perturbation explains the intensity crossflow among branches in a rotationally unresolved CIA envelope.
Article
Multidisciplinary Sciences
Kosuke Takeuchi, Kazunori Akizuki, Masatoshi Nakamura
Summary: The study found that both 100%POD and 120%POD static stretching increased ROM and passive torque, with effects lasting at least 20 minutes. Muscle-tendon unit stiffness of the hamstrings decreased significantly only at 120%POD intensity, and the effects also lasted for at least 20 minutes.
Article
Optics
I. Klincare, M. Tamanis, R. Ferber, E. A. Pazyuk, A. V. Stolyarov, I. Havalyova, A. Pashov
Summary: The relative intensity distribution in the rotationally resolved laser-induced fluorescence spectra of the KCs molecule was analyzed. The experimental intensities were described using a coupled-channels deperturbation model and compared with theoretical simulations, revealing a strong competition between different intramolecular interactions.
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
(2022)
Article
Chemistry, Physical
Franziska Dahlmann, Dennis F. Dinu, Pavol Jusko, Christine Lochmann, Thomas Gstir, Aravindh N. Marimuthu, Klaus R. Liedl, Sandra Brunken, Roland Wester
Summary: In this study, we present infrared predissociation spectra of C2N-(H-2) and C N-3(-)(H-2) obtained using the FELion cryogenic ion trap end user station at the FELIX laboratory. For C2N-(H-2), the CCN bending and CC-N stretching vibrations were observed. For the C3N-(H-2) system, the CCN bending, the CC-CN stretching, and multiple overtones and/or combination bands were detected. The experimental spectra were validated through calculations of anharmonic spectra using the vibrational configuration interaction (VCI) approach.
Article
Engineering, Environmental
Lin Du, Li Xu, Kun Li, Christian George, Maofa Ge
Summary: Anthropogenic air pollutants play a role in the formation of biogenic secondary organic aerosols (SOA), but this interaction is poorly understood. This study investigated the formation of SOA through chemical interactions between anthropogenic SO2, NH3, and O3 and biogenic S-caryophyllene. The results showed that while SO2 enhanced SOA formation, NH3 weakened this enhancing effect when coexisting with SO2. NH3 neutralized the particle acidity generated by SO2 oxidation, resulting in suppressed formation of certain products. This study highlights the importance of considering NH3 when evaluating the effects of SO2 on SOA formation via anthropogenic-biogenic interactions.
ENVIRONMENTAL SCIENCE & TECHNOLOGY LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Ruixue Wang, Kun Li, Jianlong Li, Narcisse T. Tsona, Wenxing Wang, Lin Du
Summary: Heterogeneous reactions of acidic gases on mineral dust particles affect the atmosphere, soil, and water environments during long-distance transport. However, the interactions of inorganic and organic acidic gases with aerosols are still poorly understood. In this study, the reactions of sulfur dioxide (SO2) and acrylic acid on titanium dioxide (TiO2) particles were investigated under different conditions. The results reveal the interaction of different acidic gases on the surface of particles and advance the understanding of the heterogeneous reaction of trace gases in complex atmospheric environments.
ACS EARTH AND SPACE CHEMISTRY
(2023)
Article
Chemistry, Physical
Menglan Xiao, Dawei Han, Xueqin Yang, Narcisse Tsona Tchinda, Lin Du, Yucong Guo, Yuechang Wei, Xiaolin Yu, Maofa Ge
Summary: This study constructs a Pt/Ni-CeO2 catalyst via Ni doping, which enhances the catalytic performance of toluene and improves water- and SO2-tolerance. The introduction of Ni induces the generation of abundant oxygen vacancies, facilitating the activation of oxygen species, while the formation of Pt-NiO interface structure restrains the adsorption of water and SO2 molecules.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2023)
Correction
Chemistry, Physical
Eva R. Kjaergaard, Emil Vogt, Kristian H. Moller, Ole John Nielsen, Henrik G. Kjaergaard
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Chemistry, Physical
Jing Chen, Joseph R. Lane, Henrik G. Kjaergaard
Summary: The atmospheric oxidation of dimethyl sulfide and other emitted sulfur species can lead to the formation of different sulfur-centered radicals. We performed computational investigations on the reactions of these radicals with peroxy radicals. The results show that certain sulfur-centered radicals form short-lived peroxide intermediates, while others form stable peroxide products. The valence of the sulfur atom plays a crucial role in determining the reaction outcome.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Geochemistry & Geophysics
Aijing Song, Jianlong Li, Narcisse T. Tsona, Lin Du
Summary: Sea spray aerosols (SSA) are important contributors to the global aerosol load and have a significant impact on the global climate system and chemical processes. This paper reviews the parametric dependence of SSA production fluxes on environmental variables, particularly focusing on the differences in sea spray source functions (SSSFs) and their application in global climate models and chemical transport models. The paper summarizes the influencing factors of SSA production and the progress in understanding SSSFs, and discusses the application of SSSFs in different models. The review highlights the need for further research in parameterizing SSA production fluxes to improve model simulations and evaluate the impact of SSA emissions.
APPLIED GEOCHEMISTRY
(2023)
Article
Engineering, Environmental
Jian-Lu Duan, Jing-Ya Ma, Xiao-Dong Sun, Xiao-Yu Liu, Yue Wang, Lin Du, Peng-Fei Xia, Xian-Zheng Yuan
Summary: Antibiotic resistance is a global health challenge. This study reveals how bubbles can spread antibiotic resistance genes and interact with the extracellular matrix in the aquatic environment, providing new insights into the dissemination of antibiotic resistance.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Physical
Emil Vogt, Iren Simko, Attila G. Csaszar, Henrik G. Kjaergaard
Summary: This study calculated the intramolecular vibrational transition wavenumbers and intensities in different vibrational regions of the water dimer's spectrum, and computed the rotational-vibrational spectrum in the Delta v(OH) = 2 region. The calculated spectrum was obtained by combining results from a full-dimensional vibrational model and a reduced-dimensional vibrational-rotational-tunneling model. The Delta v(OH) = 2 spectral region is characterized by multiple vibrational-rotational-tunneling sub-bands, which contribute to the rich features in the spectrum.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Chemistry, Physical
Eva Kjaergaard, Kristian Moller, Henrik Kjaergaard
Summary: This study uses advanced theoretical methods to investigate the oxidation pathways and reaction rates of hydroperoxy amides in the atmosphere, and identifies the oxidation products of hydroperoxy amides under specific conditions. The results indicate that hydroperoxy amides predominantly form imides and have slow reaction rates due to structural constraints.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Chemistry, Physical
Eva R. Kjaergaard, Kristian H. Moller, Torsten Berndt, Henrik G. Kjaergaard
Summary: Autoxidation is an important oxidation pathway in the atmosphere for various compounds, including isoprene and monoterpenes. This study reveals that autoxidation also plays a dominant role in the oxidation of nonhydrocarbons like dimethyl sulfide and trimethylamine. The research focuses on the autoxidation of triethylamine and provides theoretical calculations and experimental evidence to support the efficient autoxidation in this compound.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Correction
Chemistry, Physical
Eva R. Kjaergaard, Emil Vogt, Kristian H. Moller, Ole John Nielsen, Henrik G. Kjaergaard
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Environmental Sciences
Sara E. Murphy, John D. Crounse, Kristian H. Moller, Samir P. Rezgui, Nicholas J. Hafeman, James Park, Henrik G. Kjaergaard, Brian M. Stoltz, Paul O. Wennberg
Summary: Through experiments, we found a new ROOR substance in the reaction of RO2 center dot and HO2 center dot, which has a gas-phase branching fraction of 23%. We also observed that the ratio of the rate coefficient for the reaction of RO2 center dot + RO2 center dot to that of RO2 center dot + HO2 center dot is approximately 0.22.
ENVIRONMENTAL SCIENCE-ATMOSPHERES
(2023)
Article
Environmental Sciences
Minglan Xu, Narcisse Tsona Tchinda, Jianlong Li, Lin Du
Summary: Saccharides are important components of sea spray aerosol, and their mechanism of transfer from seawater to aerosol is still debated. This study validated the transfer of soluble saccharides and showed that they can promote the production of aerosol particles, while an insoluble fatty acid film reduces aerosol production.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2023)
Article
Environmental Sciences
Zhaomin Yang, Kun Li, Narcisse T. Tsona, Xin Luo, Lin Du
Summary: Our study investigates the effect of sulfur dioxide (SO2) on aerosol formation and composition. We found that the presence of SO2 leads to a significant increase in particle number concentration, mainly due to the formation of sulfuric acid (H2SO4) from the reactions between stabilized Criegee intermediates and SO2. Additionally, we observed the presence of organosulfates (OSs) which are likely formed through heterogeneous reactions between oxygenated species and H2SO4. These OSs have been previously identified in field studies but their sources and structures were unknown. We also found that the observed OSs are less volatile than their precursors and contribute to particle formation and growth in the presence of SO2.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2023)
Article
Chemistry, Physical
Christina Kjaer, Emil Vogt, Jeppe Langeland, Nanna Falk Christensen, Thomas Toft Lindkvist, Henrik G. Kjaergaard, Steen Brondsted Nielsen
Summary: Recent developments in fluorescence spectroscopy allow for the measurement of absorption and dispersed fluorescence spectra of isolated molecular ions at low temperatures. Lower temperatures provide narrower spectra and better information on vibronic features. Experiments were conducted on oxazine dyes cooled to around 100 K, and the results showed small Stokes shifts and broader spectra for the darrow-red cations compared to other ionic dyes.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)