After a recurring injury forced me to switch from the heavy to the light division, I relied on CrossFit to prepare my body for the physical demands of the mileage. Past participants of the memorial ...march also shared their stories with me, and reading the book Tears in the Darkness: The Story of the Bataan Death March and Its Aftermath helped me to imagine, even if barely, the real experience.3 While these stories were inspiring, nothing compared to the actual experience of being out there, talking and listening to the marchers and runners, each with their individual motivations for embarking on this journey. ...I continue to remember their sacrifice every time I lace up my shoes and value the increased physical, mental, and emotional readiness this event offers to those who take up the challenge.
A fundamentally important characteristic of a macromolecule is its shape. Herein, visible light and darkness are used as the only stimuli to reversibly alter the topology of well-defined polymers in ...a one-pot procedure. For this, linear naphthalene-containing polyacrylates are used as scaffolds for the visible light-induced cycloaddition with various substituted triazolinediones (i.e., butyl, stearyl, perfluoro, and polymeric), resulting in differently shaped graft polymers, including brushes and combs. The thus-formed cycloadduct linkages dissociate in the dark, resulting in the regeneration of the parent linear polymer at ambient temperature, establishing a dual-topology transformation by only switching green light on and off. By applying different temperatures during the cycloreversion process, the dissociation rate of the cycloadducts can be tuned in a facile manner, thus allowing for time control over the regeneration of the parent polymer. By engineering a polymer that consists of differently substituted naphthalenes at the chain ends and on the side chains, the inherently different cycloreversion rates of the formed cycloadducts are leveraged to achieve in situ multi-topology transformations without external stimuli. The shape transformations have been repeated up to 4 times sequentially in one pot without the need of any purification. The topological alterations are microscopically depicted through reversible self-assembly, with the polymers adopting different morphologies upon visible light or darkness. The versatile yet practical nature of this polymer “reshaping” strategy provides facile access to multifaceted polymer systems and, consequently, to a plethora of potential applications thereof.
Fluidity onset in graphene Bandurin, Denis A; Shytov, Andrey V; Levitov, Leonid S ...
Nature communications,
10/2018, Letnik:
9, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Viscous electron fluids have emerged recently as a new paradigm of strongly-correlated electron transport in solids. Here we report on a direct observation of the transition to this long-sought-for ...state of matter in a high-mobility electron system in graphene. Unexpectedly, the electron flow is found to be interaction-dominated but non-hydrodynamic (quasiballistic) in a wide temperature range, showing signatures of viscous flows only at relatively high temperatures. The transition between the two regimes is characterized by a sharp maximum of negative resistance, probed in proximity to the current injector. The resistance decreases as the system goes deeper into the hydrodynamic regime. In a perfect darkness-before-daybreak manner, the interaction-dominated negative response is strongest at the transition to the quasiballistic regime. Our work provides the first demonstration of how the viscous fluid behavior emerges in an interacting electron system.
Preface Welcome Speech from Rector of Universitas Syiah Kuala Assalamu’alaikum warahmatullahi wabarakatuh, In the name of Allah, the Most Beneficent and the Most Merciful. May peace, mercy, and ...blessings of Allah be upon you. Sholawat and salam may everlastingly be upon our adoration, Great Prophet Muhammad SAW, who had guided and led us from darkness into the shining bright path. Dear colleagues, professors, lecturers, researchers, ladies and gentlemen. On behalf of Universitas Syiah Kuala, I would like to express my sincere gratitude and welcome you to the 10th Annual International Conference (AIC) 2020. It is an annual conference, started in 2011 and organized by Universitas Syiah Kuala, the largest and oldest public university in Aceh. This year, the conference is conducted virtually. As usual, the conference is divided into three sub-conferences and one of them is the 10th AIC on Sciences and Engineering. I would like to thanks to the keynote and invited speakers, namely Prof. Dr. Wouter Dewulf from The University of Antwerp, Belgium; and Prof. Hamzah Fansuri, Ph.D from Institut Teknologi Sepuluh Nopember, Indonesia. who have allocated their time to fulfil the invitation, and to share knowledge and experiences from their respective academic institutions. List of Organizing Committee, Scientific Committee and Keynote & Invited Speakers are available in this pdf.
Ultraviolet (UV) disinfection during water supply treatment aims to reduce the number of bacteria. Although UV disinfection is effective at inactivating most microorganisms, some microbe species may ...be entirely impervious. A pilot study was conducted to compare the quantity and community component of bacteria in surface water collected from filtration effluent before UV disinfection with different doses of UV, and those 1 and 2 days afterwards, in darkness. The aim was to elucidate the relationship between the UV dose and the total revived microorganisms in darkness after UV disinfection. In the filtration effluent samples, Gammaproteobacteria, Bacilli, Actinobacteria, and Alphaproteobacteria were the predominant classes. After storage in the dark at a constant temperature of 19 °C, the UV-disinfected samples showed a considerable increase in Bacilli, while Gammaproteobacteria remained the predominant population. Genera such as Exiguobacterium, Citrobacter, Acinetobacter, and Pseudomonas presented a selective advantage in terms of revival in darkness after UV disinfection, irrespective of the UV dose and storage time. The lowest rate of microbial revival (5% day−1) was noted at a UV dose of 266.10 mJ m−2 (with an average UV illumination time of 124.4 s and an average intensity of 86.61 W m−2). Our results suggest that higher UV intensity and lower illumination time are key factors in minimizing the revival of microorganisms in darkness.
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•Filtration effluent was disinfected by different doses of UV illumination.•Exiguobacterium, Citrobacter, Acinetobacter, and Pseudomonas were revived in darkness.•Higher UV intensity and lower illumination duration were key to minimizing revival.
Hematopoietic stem and progenitor cells (HSPCs) tightly couple maintenance of the bone marrow (BM) reservoir, including undifferentiated long-term repopulating hematopoietic stem cells (LT-HSCs), ...with intensive daily production of mature leukocytes and blood replenishment. We found two daily peaks of BM HSPC activity that are initiated by onset of light and darkness providing this coupling. Both peaks follow transient elevation of BM norepinephrine and TNF secretion, which temporarily increase HSPC reactive oxygen species (ROS) levels. Light-induced norepinephrine and TNF secretion augments HSPC differentiation and increases vascular permeability to replenish the blood. In contrast, darkness-induced TNF increases melatonin secretion to drive renewal of HSPCs and LT-HSC potential through modulating surface CD150 and c-Kit expression, increasing COX-2/αSMA+ macrophages, diminishing vascular permeability, and reducing HSPC ROS levels. These findings reveal that light- and darkness-induced daily bursts of norepinephrine, TNF, and melatonin within the BM are essential for synchronized mature blood cell production and HSPC pool repopulation.
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•Light and dark onset induce BM NE and TNF bursts, which transiently upregulate ROS in HSPCs•NE and TNF ROS bursts induce functionally distinct 11 a.m. and 11 p.m. HSPC peaks•11 a.m. peaks of NE induce vascular permeability and HSPC differentiation and egress•11 p.m. peaks of melatonin increase CD150+ expression and HSC retention and self-renewal
Golan et al. report that daily onsets of light and dark induce NE and TNF bursts that induce two different peaks of BM HSPC activity. Light-induced NE promotes HSPC differentiation and egress, replenishing mature blood cells. Dark-induced TNF promotes melatonin-dependent renewal of CD150+ HSCs and their long-term repopulation potential.
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