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欧盟委员会通过“减排55%”一揽子计划立法方案 快报文章
气候变化快报,2023年第21期
作者:  迪里努尔 刘燕飞
Microsoft Word(15Kb)  |  收藏  |  浏览/下载:510/0  |  提交时间:2023/11/05
Fit for 55  Renewable Energy Directive  ReFuelEU Aviation Regulation  
Ball-and-chain inactivation in a calcium-gated potassium channel 期刊论文
NATURE, 2020, 580 (7802) : 288-+
作者:  Peron, Simon;  Pancholi, Ravi;  Voelcker, Bettina;  Wittenbach, Jason D.;  olafsdottir, H. Freyja;  Freeman, Jeremy;  Svoboda, Karel
收藏  |  浏览/下载:22/0  |  提交时间:2020/07/03

Cryo-electron microscopy structures and molecular dynamics simulations of the calcium-activated potassium channel MthK from Methanobacterium thermoautotrophicum are used to show that gating of this channel involves a ball-and-chain inactivation mechanism mediated by a previously unresolved N-terminal peptide.


Inactivation is the process by which ion channels terminate ion flux through their pores while the opening stimulus is still present(1). In neurons, inactivation of both sodium and potassium channels is crucial for the generation of action potentials and regulation of firing frequency(1,2). A cytoplasmic domain of either the channel or an accessory subunit is thought to plug the open pore to inactivate the channel via a '  ball-and-chain'  mechanism(3-7). Here we use cryo-electron microscopy to identify the molecular gating mechanism in calcium-activated potassium channels by obtaining structures of the MthK channel from Methanobacterium thermoautotrophicum-a purely calcium-gated and inactivating channel-in a lipid environment. In the absence of Ca2+, we obtained a single structure in a closed state, which was shown by atomistic simulations to be highly flexible in lipid bilayers at ambient temperature, with large rocking motions of the gating ring and bending of pore-lining helices. In Ca2+-bound conditions, we obtained several structures, including multiple open-inactivated conformations, further indication of a highly dynamic protein. These different channel conformations are distinguished by rocking of the gating rings with respect to the transmembrane region, indicating symmetry breakage across the channel. Furthermore, in all conformations displaying open channel pores, the N terminus of one subunit of the channel tetramer sticks into the pore and plugs it, with free energy simulations showing that this is a strong interaction. Deletion of this N terminus leads to functionally non-inactivating channels and structures of open states without a pore plug, indicating that this previously unresolved N-terminal peptide is responsible for a ball-and-chain inactivation mechanism.


  
Sex-specific adipose tissue imprinting of regulatory T cells 期刊论文
NATURE, 2020, 579 (7800) : 581-+
作者:  Qureshi, Abdul Aziz;  Suades, Albert;  Matsuoka, Rei;  Brock, Joseph;  McComas, Sarah E.;  Nji, Emmanuel;  Orellana, Laura;  Claesson, Magnus;  Delemotte, Lucie;  Drew, David
收藏  |  浏览/下载:13/0  |  提交时间:2020/07/03

Adipose tissue is an energy store and a dynamic endocrine organ(1,2). In particular, visceral adipose tissue (VAT) is critical for the regulation of systemic metabolism(3,4). Impaired VAT function-for example, in obesity-is associated with insulin resistance and type 2 diabetes(5,6). Regulatory T (T-reg) cells that express the transcription factor FOXP3 are critical for limiting immune responses and suppressing tissue inflammation, including in the VAT(7-9). Here we uncover pronounced sexual dimorphism in T-reg cells in the VAT. Male VAT was enriched for T-reg cells compared with female VAT, and T-reg cells from male VAT were markedly different from their female counterparts in phenotype, transcriptional landscape and chromatin accessibility. Heightened inflammation in the male VAT facilitated the recruitment of T-reg cells via the CCL2-CCR2 axis. Androgen regulated the differentiation of a unique IL-33-producing stromal cell population specific to the male VAT, which paralleled the local expansion of T-reg cells. Sex hormones also regulated VAT inflammation, which shaped the transcriptional landscape of VAT-resident T-reg cells in a BLIMP1 transcription factor-dependent manner. Overall, we find that sex-specific differences in T-reg cells from VAT are determined by the tissue niche in a sex-hormone-dependent manner to limit adipose tissue inflammation.


Visceral adipose tissue contains populations of regulatory T cells that exhibit sexual dimorphism, determined by the surrounding niche, and differ between male and female mice in terms of cell number, phenotype, transcriptional landscape and chromatin accessibility.


  
Synthesis of rare sugar isomers through site-selective epimerization 期刊论文
NATURE, 2020: 403-+
作者:  Jackson, Hartland W.;  Fischer, Jana R.;  Zanotelli, Vito R. T.;  Ali, H. Raza;  Mechera, Robert;  Soysal, Savas D.;  Moch, Holger;  Muenst, Simone;  Varga, Zsuzsanna;  Weber, Walter P.;  Bodenmiller, Bernd
收藏  |  浏览/下载:15/0  |  提交时间:2020/07/03

Glycans have diverse physiological functions, ranging from energy storage and structural integrity to cell signalling and the regulation of intracellular processes(1). Although biomass-derived carbohydrates (such as d-glucose, d-xylose and d-galactose) are extracted on commercial scales, and serve as renewable chemical feedstocks and building blocks(2,3), there are hundreds of distinct monosaccharides that typically cannot be isolated from their natural sources and must instead be prepared through multistep chemical or enzymatic syntheses(4,5). These '  rare'  sugars feature prominently in bioactive natural products and pharmaceuticals, including antiviral, antibacterial, anticancer and cardiac drugs(6,7). Here we report the preparation of rare sugar isomers directly from biomass carbohydrates through site-selective epimerization reactions. Mechanistic studies establish that these reactions proceed under kinetic control, through sequential steps of hydrogen-atom abstraction and hydrogen-atom donation mediated by two distinct catalysts. This synthetic strategy provides concise and potentially extensive access to this valuable class of natural compounds.


Various rare sugars that cannot be isolated from natural sources are synthesized using light-driven epimerization, a process which may find application in other synthetic scenarios.


  
Investigating the environmental effectiveness of Overall Thermal Transfer Value code and its implication to energy regulation development 期刊论文
ENERGY POLICY, 2019, 130: 172-180
作者:  Chan, Lok Shun
收藏  |  浏览/下载:5/0  |  提交时间:2019/11/27
Building energy regulation  Energy-efficient building  Building envelope design  Embodied energy  Energy payback period  
The energy paradox in seemingly competitive industries: The use of energy efficient equipment on heavy-duty tractor trailers 期刊论文
ENERGY POLICY, 2019, 129: 467-480
作者:  Fraas, Arthur G.;  Lutter, Randall W.;  Wietelman, Derek C.
收藏  |  浏览/下载:5/0  |  提交时间:2019/11/26
Energy efficiency  Energy gap  Energy paradox  Environmental regulation  Market failure  Split incentive  
The distributional impacts of US energy policy 期刊论文
ENERGY POLICY, 2019, 129: 926-929
作者:  Metcalf, Gilbert E.
收藏  |  浏览/下载:3/0  |  提交时间:2019/11/26
Energy policy  Regulation  Taxation  Climate policy  Distribution  
Recommendation to ASEAN nuclear development based on lessons learnt from the Fukushima nuclear accident 期刊论文
ENERGY POLICY, 2019, 129: 628-635
作者:  Kosai, Shoki;  Yamasue, Eiji
收藏  |  浏览/下载:6/0  |  提交时间:2019/11/26
Civic engagement  Energy literacy  Nuclear policy  Regulatory body  Regulation  Association of South-East Asian Nations  
Evaluating regulatory strategies for mitigating hydrological risk in Brazil through diversification of its electricity mix 期刊论文
ENERGY POLICY, 2019, 128: 393-401
作者:  Paim, Maria-Augusta;  Dalmarco, Arthur R.;  Yang, Chung-Han;  Salas, Pablo;  Lindner, Soren;  Mercure, Jean-Francois;  Osorio de Andrade Guerra, Jose Baltazar Salgueirinho;  Derani, Cristiane;  da Silva, Tatiana Bruce;  Vinuales, Jorge E.
收藏  |  浏览/下载:21/0  |  提交时间:2019/11/26
Hydropower  Hydrological risk  Electricity mix  Water-Energy-Food Nexus  Brazilian law and regulation  Integrated Assessment Modelling (lAM)  
Why Ghana will not achieve its renewable energy target for electricity. Policy, legal and regulatory implications 期刊论文
ENERGY POLICY, 2019, 128: 75-83
作者:  Obeng-Darko, Nana Asare
收藏  |  浏览/下载:4/0  |  提交时间:2019/11/26
Renewable energy target  Ghana  Renewable energy policy  Renewable energy law  Regulation