| 2 | Observation of a single protein by ultrafast X-ray diffraction显示文摘The idea of using ultrashort X-ray pulses to obtain images of single proteins frozen in time has fascinated and inspired many.It was one of the arguments for building X-ray free-electron lasers.According to theory,the extremely intense pulses provide sufficient signal to dispense with using crystals as an amplifier,and the ultrashort pulse duration permits capturing the diffraction data before the sample inevitably explodes.This was first demonstrated on biological samples a decade ago on the giant mimivirus.Since then,a large collaboration has been pushing the limit of the smallest sample that can be imaged.The ability to capture snapshots on the timescale of atomic vibrations,while keeping the sample at room temperature,may allow probing the entire conformational phase space of macromolecules.Here we show the first observation of an X-ray diffraction pattern from a single protein,that of Escherichia coli GroEL which at 14 nm in diameter is the smallest biological sample ever imaged by X-rays,and demonstrate that the concept of diffraction before destruction extends to single proteins.From the pattern,it is possible to determine the approximate orientation of the protein.Our experiment demonstrates the feasibility of ultrafast imaging of single proteins,opening the way to single-molecule time-resolved studies on the femtosecond timescale. | Tomas Ekeberg Dameli Assalauova Johan Bielecki Rebecca Boll Benedikt J.Daurer Lutz A.Eichacker Linda E.Franken Davide E.Galli Luca Gelisio Lars Gumprecht Laura H.Gunn Janos Hajdu Robert Hartmann Dirk Hasse Alexandr Ignatenko Jayanath Koliyadu Olena Kulyk Ruslan Kurta Markus Kuster Wolfgang Lugmayr Jannik Lübke Adrian P.Mancuso Tommaso Mazza Carl Nettelblad Yevheniy Ovcharenko Daniel E.Rivas Max Rose Amit K.Samanta Philipp Schmidt Egor Sobolev Nicusor Timneanu Sergey Usenko Daniel Westphal Tamme Wollweber Lena Worbs Paul Lourdu Xavier Hazem Yousef Kartik Ayyer Henry N.Chapman Jonas A.Sellberg Carolin Seuring Ivan A.Vartanyants Jochen Küpper Michael Meyer Filipe R.N.C.Maia | 2024 | Light(Science & Applications)2024，13，1： | 0 |
| 3 | Diverse morphologies of zinc oxide nanoparticles and their electrocatalytic performance in hydrogen production显示文摘Hydrogen is considered an attractive alternative to fossil fuels,but only a small amount of it is produced from renewable energy,making it not such a clean energy carrier after all.Producing hydrogen through water electrolysis is promising,but using a cost-effective and high-performing catalyst that has longterm stability is still a challenge.This study exploits,for the first time,the potential of zinc oxide nanoparticles with diverse morphologies as catalysts for the electrocatalytic production of hydrogen from water.The morphology of the nanoparticles(wires,cuboids,spheres)was easily regulated by changing the concentration of sodium hydroxide,used as the shape controlling agent,during the synthesis.The spherical morphology exhibited the highest electrocatalytic activity at the lowest potential voltage.These spherical nanoparticles had the highest number of oxygen vacancies and lowest particle size compared to the other two morphologies,features directly linked to high catalytic activity.However,the nanowires were much more stable with repeated scans.Density-functional theory showed that the presence of oxygen vacancies in all three morphologies led to diminished band gaps,which is of catalytic interest. | Veronica M.Sofianos Junqiao Lee Debbie S.Silvester Pralok K.Samanta Mark Paskevicius Niall J.English Craig E.Buckley | 2021 | Journal of Energy Chemistry2021，30，5： | 0 |
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