TY  - JOUR
A1  - Yang, Jie
A1  - Zhu, Xiaolei
A1  - Wolf, Thomas J. A.
A1  - Li, Zheng
A1  - Nunes, João Pedro Figueira
A1  - Coffee, Ryan
A1  - Cryan, James P.
A1  - Gühr, Markus
A1  - Hegazy, Kareem
A1  - Heinz, Tony F.
A1  - Jobe, Keith
A1  - Li, Renkai
A1  - Shen, Xiaozhe
A1  - Veccione, Theodore
A1  - Weathersby, Stephen
A1  - Wilkin, Kyle J.
A1  - Yoneda, Charles
A1  - Zheng, Qiang
A1  - Martinez, Todd J.
A1  - Centurion, Martin
A1  - Wang, Xijie
T1  - Imaging CF3I conical intersection and photodissociation dynamics with ultrafast electron diffraction
JF  - Science
N2  - Conical intersections play a critical role in excited-state dynamics of polyatomic molecules because they govern the reaction pathways of many nonadiabatic processes. However, ultrafast probes have lacked sufficient spatial resolution to image wave-packet trajectories through these intersections directly. Here, we present the simultaneous experimental characterization of one-photon and two-photon excitation channels in isolated CF3I molecules using ultrafast gas-phase electron diffraction. In the two-photon channel, we have mapped out the real-space trajectories of a coherent nuclear wave packet, which bifurcates onto two potential energy surfaces when passing through a conical intersection. In the one-photon channel, we have resolved excitation of both the umbrella and the breathing vibrational modes in the CF3 fragment in multiple nuclear dimensions. These findings benchmark and validate ab initio nonadiabatic dynamics calculations.
Y1  - 2018
U6  - https://doi.org/10.1126/science.aat0049
SN  - 0036-8075
SN  - 1095-9203
VL  - 361
IS  - 6397
SP  - 64
EP  - 67
PB  - American Assoc. for the Advancement of Science
CY  - Washington
ER  - 
TY  - JOUR
A1  - Wilkin, Kyle J.
A1  - Parrish, Robert M.
A1  - Yang, Jie
A1  - Wolf, Thomas J. A.
A1  - Nunes, J. Pedro F.
A1  - Gühr, Markus
A1  - Li, Renkai
A1  - Shen, Xiaozhe
A1  - Zheng, Qiang
A1  - Wang, Xijie
A1  - Martinez, Todd J.
A1  - Centurion, Martin
T1  - Diffractive imaging of dissociation and ground-state dynamics in a complex molecule
JF  - Physical review : A, Atomic, molecular, and optical physics
N2  - We have investigated the structural dynamics in photoexcited 1,2-diiodotetrafluoroethane molecules (C2F4I2) in the gas phase experimentally using ultrafast electron diffraction and theoretically using FOMO-CASCI excited-state dynamics simulations. The molecules are excited by an ultraviolet femtosecond laser pulse to a state characterized by a transition from the iodine 5p perpendicular to orbital to a mixed 5p parallel to sigma hole and CF2 center dot antibonding orbital, which results in the cleavage of one of the carbon-iodine bonds. We have observed, with sub-Angstrom resolution, the motion of the nuclear wave packet of the dissociating iodine atom followed by coherent vibrations in the electronic ground state of the C2F4I radical. The radical reaches a stable classical (nonbridged) structure in less than 200 fs.
Y1  - 2019
U6  - https://doi.org/10.1103/PhysRevA.100.023402
SN  - 2469-9926
SN  - 2469-9934
VL  - 100
IS  - 2
PB  - American Physical Society
CY  - College Park
ER  - 
TY  - BOOK
A1  - Bowler, Margit
A1  - Hsieh, I-Ta Chris
A1  - Shen, Zheng
A1  - Korat, Omer
A1  - Tran, Thuan
ED  - Grubic, Mira
ED  - Mucha, Anne
T1  - Proceedings of the Semantics of African, Asian and Austronesian Languages (TripleA) 2
N2  - TripleA is a workshop series founded by linguists from the University of Tübingen and the University of Potsdam. Its aim is to provide a forum for semanticists doing fieldwork on understudied languages, and its focus is on languages from Africa, Asia, Australia and Oceania. The second TripleA workshop was held at the University of Potsdam, June 3-5, 2015.
KW  - formal semantics
KW  - understudied languages
KW  - Warlpiri
KW  - Mandarin
KW  - Hebrew
KW  - Vietnamese
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-91742
ER  - 
TY  - JOUR
A1  - Wolf, Thomas J. A.
A1  - Sanchez, David M.
A1  - Yang, J.
A1  - Parrish, R. M.
A1  - Nunes, J. P. F.
A1  - Centurion, M.
A1  - Coffee, R.
A1  - Cryan, J. P.
A1  - Gühr, Markus
A1  - Hegazy, Kareem
A1  - Kirrander, Adam
A1  - Li, R. K.
A1  - Ruddock, J.
A1  - Shen, Xiaozhe
A1  - Vecchione, T.
A1  - Weathersby, S. P.
A1  - Weber, Peter M.
A1  - Wilkin, K.
A1  - Yong, Haiwang
A1  - Zheng, Q.
A1  - Wang, X. J.
A1  - Minitti, Michael P.
A1  - Martinez, Todd J.
T1  - The photochemical ring-opening of 1,3-cyclohexadiene imaged by ultrafast electron diffraction
JF  - Nature chemistry
N2  - The ultrafast photoinduced ring-opening of 1,3-cyclohexadiene constitutes a textbook example of electrocyclic reactions in organic chemistry and a model for photobiological reactions in vitamin D synthesis. Although the relaxation from the photoexcited electronic state during the ring-opening has been investigated in numerous studies, the accompanying changes in atomic distance have not been resolved. Here we present a direct and unambiguous observation of the ring-opening reaction path on the femtosecond timescale and subangstrom length scale using megaelectronvolt ultrafast electron diffraction. We followed the carbon-carbon bond dissociation and the structural opening of the 1,3-cyclohexadiene ring by the direct measurement of time-dependent changes in the distribution of interatomic distances. We observed a substantial acceleration of the ring-opening motion after internal conversion to the ground state due to a steepening of the electronic potential gradient towards the product minima. The ring-opening motion transforms into rotation of the terminal ethylene groups in the photoproduct 1,3,5-hexatriene on the subpicosecond timescale.
KW  - Organic chemistry
KW  - Photochemistry
KW  - Physical chemistry
KW  - Theoretical chemistry
Y1  - 2019
U6  - https://doi.org/10.1038/s41557-019-0252-7
SN  - 1755-4330
SN  - 1755-4349
VL  - 11
IS  - 6
SP  - 504
EP  - 509
PB  - Nature Publ. Group
CY  - London
ER  - 
TY  - JOUR
A1  - Tang, Alan T.
A1  - Sullivan, Katie Rose
A1  - Hong, Courtney C.
A1  - Goddard, Lauren M.
A1  - Mahadevan, Aparna
A1  - Ren, Aileen
A1  - Pardo, Heidy
A1  - Peiper, Amy
A1  - Griffin, Erin
A1  - Tanes, Ceylan
A1  - Mattei, Lisa M.
A1  - Yang, Jisheng
A1  - Li, Li
A1  - Mericko-Ishizuka, Patricia
A1  - Shen, Le
A1  - Hobson, Nicholas
A1  - Girard, Romuald
A1  - Lightle, Rhonda
A1  - Moore, Thomas
A1  - Shenkar, Robert
A1  - Polster, Sean P.
A1  - Roedel, Claudia Jasmin
A1  - Li, Ning
A1  - Zhu, Qin
A1  - Whitehead, Kevin J.
A1  - Zheng, Xiangjian
A1  - Akers, Amy
A1  - Morrison, Leslie
A1  - Kim, Helen
A1  - Bittinger, Kyle
A1  - Lengner, Christopher J.
A1  - Schwaninger, Markus
A1  - Velcich, Anna
A1  - Augenlicht, Leonard
A1  - Abdelilah-Seyfried, Salim
A1  - Min, Wang
A1  - Marchuk, Douglas A.
A1  - Awad, Issam A.
A1  - Kahn, Mark L.
T1  - Distinct cellular roles for PDCD10 define a gut-brain axis in cerebral cavernous malformation
JF  - Science Translational Medicine
N2  - Cerebral cavernous malformation (CCM) is a genetic, cerebrovascular disease. Familial CCM is caused by genetic mutations in KRIT1, CCM2, or PDCD10. Disease onset is earlier and more severe in individuals with PDCD10 mutations. Recent studies have shown that lesions arise from excess mitogen-activated protein kinase kinase kinase 3 (MEKK3) signaling downstream of Toll-like receptor 4 (TLR4) stimulation by lipopolysaccharide derived from the gut microbiome. These findings suggest a gut-brain CCM disease axis but fail to define it or explain the poor prognosis of patients with PDCD10 mutations. Here, we demonstrate that the gut barrier is a primary determinant of CCM disease course, independent of microbiome configuration, that explains the increased severity of CCM disease associated with PDCD10 deficiency. Chemical disruption of the gut barrier with dextran sulfate sodium augments CCM formation in a mouse model, as does genetic loss of Pdcd10, but not Krit1, in gut epithelial cells. Loss of gut epithelial Pdcd10 results in disruption of the colonic mucosal barrier. Accordingly, loss of Mucin-2 or exposure to dietary emulsifiers that reduce the mucus barrier increases CCM burden analogous to loss of Pdcd10 in the gut epithelium. Last, we show that treatment with dexamethasone potently inhibits CCM formation in mice because of the combined effect of action at both brain endothelial cells and gut epithelial cells. These studies define a gut-brain disease axis in an experimental model of CCM in which a single gene is required for two critical components: gut epithelial function and brain endothelial signaling.
Y1  - 2019
U6  - https://doi.org/10.1126/scitranslmed.aaw3521
SN  - 1946-6234
SN  - 1946-6242
VL  - 11
IS  - 520
PB  - American Assoc. for the Advancement of Science
CY  - Washington
ER  - 
TY  - JOUR
A1  - Hsieh, I-Ta Chris
A1  - Shen, Zheng
ED  - Grubic, Mira
ED  - Mucha, Anne
T1  - The ‘Associative Reading’ of DPs and the quantity vs. quality distinction
JF  - Proceedings of the Semantics of African, Asian and Austronesian Languages (TripleA) 2
N2  - This paper investigates an unnoticed difference in Mandarin between the Q-adjectives and the gradable adjectives of quality and shows that this observation follows straightforwardly from a theory that differentiates gradable predication of quantity and that of quality (e.g., Rett 2008; Lin 2014; Solt 2015; a.o.).
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-92304
SP  - 18
EP  - 35
ER  - 
TY  - JOUR
A1  - Wang, Feipeng
A1  - Zhang, Zheng
A1  - Yan, Yuyang
A1  - Shen, Zijia
A1  - Wang, Qiang
A1  - Gerhard, Reimund
T1  - Surface reconstruction on electro-spun PVA/PVP nanofibers by water evaporation
JF  - Nanomaterials
N2  - Tailoring the secondary surface morphology of electro-spun nanofibers has been highly desired, as such delicate structures equip nanofibers with distinct functions. Here, we report a simple strategy to directly reconstruct the surface of polyvinyl alcohol/polyvinylpyrrolidone (PVA/PVP) nanofibers by water evaporation. The roughness and diameter of the nanofibers depend on the temperature during vacuum drying. Surface changes of the nanofibers from smooth to rough were observed at 55 degrees C, with a significant drop in nanofiber diameter. We attribute the formation of the secondary surface morphology to the intermolecular forces in the water vapor, including capillary and the compression forces, on the basis of the results from the Fourier-transform infrared (FTIR) and X-ray photoelectron (XPS) spectroscopy. The strategy is universally effective for various electro-spun polymer nanofibers, thus opening up avenues toward more detailed and sophisticated structure design and implementation for nanofibers.
KW  - surface reconstruction
KW  - intermolecular force
KW  - surface-roughened
KW  - nanofiber
Y1  - 2022
U6  - https://doi.org/10.3390/nano12050797
SN  - 2079-4991
VL  - 12
IS  - 5
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Cao, Xianyong
A1  - Chen, Jianhui
A1  - Tian, Fang
A1  - Xu, Qinghai
A1  - Herzschuh, Ulrike
A1  - Telford, Richard
A1  - Huang, Xiaozhong
A1  - Zheng, Zhuo
A1  - Shen, Caiming
A1  - Li, Wenjia
T1  - Long-distance modern analogues bias results of pollen-based precipitation reconstructions
JF  - Science bulletin
Y1  - 2022
U6  - https://doi.org/10.1016/j.scib.2022.01.003
SN  - 2095-9273
SN  - 2095-9281
VL  - 67
IS  - 11
SP  - 1115
EP  - 1117
PB  - Elsevier
CY  - Amsterdam
ER  -