@article{YangZhuWolfetal.2018, author = {Yang, Jie and Zhu, Xiaolei and Wolf, Thomas J. A. and Li, Zheng and Nunes, Jo{\~a}o Pedro Figueira and Coffee, Ryan and Cryan, James P. and G{\"u}hr, Markus and Hegazy, Kareem and Heinz, Tony F. and Jobe, Keith and Li, Renkai and Shen, Xiaozhe and Veccione, Theodore and Weathersby, Stephen and Wilkin, Kyle J. and Yoneda, Charles and Zheng, Qiang and Martinez, Todd J. and Centurion, Martin and Wang, Xijie}, title = {Imaging CF3I conical intersection and photodissociation dynamics with ultrafast electron diffraction}, series = {Science}, volume = {361}, journal = {Science}, number = {6397}, publisher = {American Assoc. for the Advancement of Science}, address = {Washington}, issn = {0036-8075}, doi = {10.1126/science.aat0049}, pages = {64 -- 67}, year = {2018}, abstract = {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.}, language = {en} } @article{WilkinParrishYangetal.2019, author = {Wilkin, Kyle J. and Parrish, Robert M. and Yang, Jie and Wolf, Thomas J. A. and Nunes, J. Pedro F. and G{\"u}hr, Markus and Li, Renkai and Shen, Xiaozhe and Zheng, Qiang and Wang, Xijie and Martinez, Todd J. and Centurion, Martin}, title = {Diffractive imaging of dissociation and ground-state dynamics in a complex molecule}, series = {Physical review : A, Atomic, molecular, and optical physics}, volume = {100}, journal = {Physical review : A, Atomic, molecular, and optical physics}, number = {2}, publisher = {American Physical Society}, address = {College Park}, issn = {2469-9926}, doi = {10.1103/PhysRevA.100.023402}, pages = {10}, year = {2019}, abstract = {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.}, language = {en} } @book{BowlerHsiehShenetal.2016, author = {Bowler, Margit and Hsieh, I-Ta Chris and Shen, Zheng and Korat, Omer and Tran, Thuan}, title = {Proceedings of the Semantics of African, Asian and Austronesian Languages (TripleA) 2}, editor = {Grubic, Mira and Mucha, Anne}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-91742}, publisher = {Universit{\"a}t Potsdam}, pages = {64}, year = {2016}, abstract = {TripleA is a workshop series founded by linguists from the University of T{\"u}bingen 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.}, language = {en} } @article{WolfSanchezYangetal.2019, author = {Wolf, Thomas J. A. and Sanchez, David M. and Yang, J. and Parrish, R. M. and Nunes, J. P. F. and Centurion, M. and Coffee, R. and Cryan, J. P. and G{\"u}hr, Markus and Hegazy, Kareem and Kirrander, Adam and Li, R. K. and Ruddock, J. and Shen, Xiaozhe and Vecchione, T. and Weathersby, S. P. and Weber, Peter M. and Wilkin, K. and Yong, Haiwang and Zheng, Q. and Wang, X. J. and Minitti, Michael P. and Martinez, Todd J.}, title = {The photochemical ring-opening of 1,3-cyclohexadiene imaged by ultrafast electron diffraction}, series = {Nature chemistry}, volume = {11}, journal = {Nature chemistry}, number = {6}, publisher = {Nature Publ. Group}, address = {London}, issn = {1755-4330}, doi = {10.1038/s41557-019-0252-7}, pages = {504 -- 509}, year = {2019}, abstract = {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.}, language = {en} } @article{TangSullivanHongetal.2019, author = {Tang, Alan T. and Sullivan, Katie Rose and Hong, Courtney C. and Goddard, Lauren M. and Mahadevan, Aparna and Ren, Aileen and Pardo, Heidy and Peiper, Amy and Griffin, Erin and Tanes, Ceylan and Mattei, Lisa M. and Yang, Jisheng and Li, Li and Mericko-Ishizuka, Patricia and Shen, Le and Hobson, Nicholas and Girard, Romuald and Lightle, Rhonda and Moore, Thomas and Shenkar, Robert and Polster, Sean P. and Roedel, Claudia Jasmin and Li, Ning and Zhu, Qin and Whitehead, Kevin J. and Zheng, Xiangjian and Akers, Amy and Morrison, Leslie and Kim, Helen and Bittinger, Kyle and Lengner, Christopher J. and Schwaninger, Markus and Velcich, Anna and Augenlicht, Leonard and Abdelilah-Seyfried, Salim and Min, Wang and Marchuk, Douglas A. and Awad, Issam A. and Kahn, Mark L.}, title = {Distinct cellular roles for PDCD10 define a gut-brain axis in cerebral cavernous malformation}, series = {Science Translational Medicine}, volume = {11}, journal = {Science Translational Medicine}, number = {520}, publisher = {American Assoc. for the Advancement of Science}, address = {Washington}, issn = {1946-6234}, doi = {10.1126/scitranslmed.aaw3521}, pages = {14}, year = {2019}, abstract = {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.}, language = {en} } @article{HsiehShen2016, author = {Hsieh, I-Ta Chris and Shen, Zheng}, title = {The 'Associative Reading' of DPs and the quantity vs. quality distinction}, series = {Proceedings of the Semantics of African, Asian and Austronesian Languages (TripleA) 2}, journal = {Proceedings of the Semantics of African, Asian and Austronesian Languages (TripleA) 2}, editor = {Grubic, Mira and Mucha, Anne}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-92304}, pages = {18 -- 35}, year = {2016}, abstract = {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.).}, language = {en} } @article{WangZhangYanetal.2022, author = {Wang, Feipeng and Zhang, Zheng and Yan, Yuyang and Shen, Zijia and Wang, Qiang and Gerhard, Reimund}, title = {Surface reconstruction on electro-spun PVA/PVP nanofibers by water evaporation}, series = {Nanomaterials}, volume = {12}, journal = {Nanomaterials}, number = {5}, publisher = {MDPI}, address = {Basel}, issn = {2079-4991}, doi = {10.3390/nano12050797}, pages = {7}, year = {2022}, abstract = {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.}, language = {en} } @article{CaoChenTianetal.2022, author = {Cao, Xianyong and Chen, Jianhui and Tian, Fang and Xu, Qinghai and Herzschuh, Ulrike and Telford, Richard and Huang, Xiaozhong and Zheng, Zhuo and Shen, Caiming and Li, Wenjia}, title = {Long-distance modern analogues bias results of pollen-based precipitation reconstructions}, series = {Science bulletin}, volume = {67}, journal = {Science bulletin}, number = {11}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2095-9273}, doi = {10.1016/j.scib.2022.01.003}, pages = {1115 -- 1117}, year = {2022}, language = {en} }