Background. Diabetic nephropathy (DN) is an important cause of end-stage renal disease and is recognized as a public health problem worldwide. However, there have been no nationwide surveys of DN ...prevalence in China. This study is aimed at estimating the pooled prevalence of DN among patients with type 2 diabetes in China. Methods. Published studies on the prevalence of DN among patients with type 2 diabetes published from January 1980 to October 2019 were systematically reviewed using PubMed, Embase, Google Scholar, Chinese Wanfang databases, and Chinese National Knowledge Infrastructure. The pooled prevalence of DN was estimated with the random effects model using R software. Prevalence estimates were also stratified by study design, methodological approach, and study population characteristics. Results. Thirty studies with a total of 79,364 participants were included in our study. The overall pooled prevalence of DN was 21.8% 95% confidence interval (CI): 18.5-25.4%. Subgroup analysis found that the prevalence of DN varied significantly according to different DM and DN diagnostic criteria (P<0.05); the pooling estimate was the highest in the west region of 41.3%, followed by that in the east region of China with 22.3%, northeast region with 20.7%, and central region with 15.6% (P<0.05), and was higher in the male-dominated studies 27.7%, compared with the female-dominated studies 17.6% (P<0.05). Conclusions. The prevalence of DN is high in Chinese patients with type 2 diabetes and shows geographic and gender variation. These data indicate that national strategies aimed at primary and secondary prevention of DN and screening programs for DN are urgently needed to reduce the risk and burden of DN in China.
A feasible and umpolung strategy for the synthesis of structurally diverse β‐amino ketones has been achieved through TEMPO mediated C−N coupling of cyclopropanols with nitrogen nucleophiles. ...Mechanism studies indicated that in situ generated enones derived from cyclopropanols are the key intermediates and TEMPO play multiple roles, including radical initiator, trapping reagent, a porter of β‐hydrogen and an in situ base. This protocol features broad substrate scope, good scalability and good to excellent yields and provides an alternative and complementary approach to the synthesis of structurally important β‐amino ketone scaffolds under metal and additive‐free conditions.
Na‐ion batteries (NIBs) are ideal candidates for solving the problem of large‐scale energy storage, due to the worldwide sodium resource, but the efforts in exploring and synthesizing low‐cost and ...eco‐friendly anode materials with convenient technologies and low‐cost raw materials are still insufficient. Herein, with the assistance of a simple calcination method and common raw materials, the environmentally friendly and nontoxic N‐doped C@Zn3B2O6 composite is directly synthesized and proved to be a potential anode material for NIBs. The composite demonstrates a high reversible charge capacity of 446.2 mAh g−1 and a safe and suitable average voltage of 0.69 V, together with application potential in full cells (discharge capacity of 98.4 mAh g−1 and long cycle performance of 300 cycles at 1000 mA g−1). In addition, the sodium‐ion storage mechanism of N‐doped C@Zn3B2O6 is subsequently studied through air‐insulated ex situ characterizations of X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), and Fourier‐transform infrared (FT‐IR) spectroscopy, and is found to be rather different from previous reports on borate anode materials for NIBs and lithium‐ion batteries. The reaction mechanism is deduced and proposed as: Zn3B2O6 + 6Na+ + 6e− ⇋ 3Zn + B2O3 ∙ 3Na2O, which indicates that the generated boracic phase is electrochemically active and participates in the later discharge/charge progress.
N‐doped C@Zn3B2O6 (NC@ZBO) composite is chemically synthesized in a green manner through a simple method, and shows considerable sodium‐ion storage ability, including high reversible charge capacity (446.2 mAh g−1) and suitable average voltage (0.69 V), together with application potential in full cells (300 cycles). The sodium‐ion storage mechanism of Zn3B2O6 is also found rather different from relevant experiments on borates and deduced to be Zn3B2O6 + 6Na+ + 6e− ⇋ 3Zn + B2O3 · 3Na2O.
Li‐O2 batteries with ultrahigh theoretical energy densities usually suffer from low practical discharge capacities and inferior cycling stability owing to the cathode passivation caused by insulating ...discharge products and by‐products. Here, a trifunctional ether‐based redox mediator, 2,5‐di‐tert‐butyl‐1,4‐dimethoxybenzene (DBDMB), is introduced into the electrolyte to capture reactive O2− and alleviate the rigorous oxidative environment of Li‐O2 batteries. Thanks to the strong solvation effect of DBDMB towards Li+ and O2−, it not only reduces the formation of by‐products (a high Li2O2 yield of 96.6 %), but also promotes the solution growth of large‐sized Li2O2 particles, avoiding the passivation of cathode as well as enabling a large discharge capacity. Moreover, DBDMB makes the oxidization of Li2O2 and the decomposition of main by‐products (Li2CO3 and LiOH) proceed in a highly effective manner, prolonging the stability of Li‐O2 batteries (243 cycles at 1000 mAh g−1 and 1000 mA g−1).
A trifunctional ether‐based redox mediator, DBDMB, is introduced into the electrolyte to capture reactive discharge intermediates (O2−) with reduced formation of by‐products, regulate solution growth of Li2O2, and co‐oxidize Li2O2 and by‐products (Li2CO3 and LiOH). Li‐O2 batteries with large capacity and long cycling stability have been achieved.
Nitrogen‐doped carbon (NC) materials have been proposed as next‐generation oxygen reduction reaction (ORR) catalysts to significantly improve scalability and reduce costs, but these alternatives ...usually exhibit low activity and/or gradual deactivation during use. Here, we develop new 2D sandwich‐like zeolitic imidazolate framework (ZIF) derived graphene‐based nitrogen‐doped porous carbon sheets (GNPCSs) obtained by in situ growing ZIF on graphene oxide (GO). Compared to commercial Pt/C catalyst, the GNPCSs show comparable onset potential, higher current density, and especially an excellent tolerance to methanol and superior durability in the ORR. Those properties might be attributed to a synergistic effect between NC and graphene with regard to structure and composition. Furthermore, higher open‐circuit voltage and power density are obtained in direct methanol fuel cells.
Nitrogen‐doped: A new oxygen reduction reaction electrocatalyst was obtained from ZIF‐derived porous carbon and graphene. The catalyst exhibits high activity, superior tolerance to methanol, and good stability in comparison to commercial Pt/C catalyst.
In the current universe, the dominant energy components are dark energy and dark matter. There is a longstanding conjecture that there might be some direct coupling between dark energy and dark ...matter （for a recent review, see ref. 1）. The advantages for considering such a possibility include, for example, those that it can alleviate the ＂cosmic coincidence＂ puzzle, can avoid the ＂big rip＂ in a phantom scenario, and so on. We call the scenario in which dark energy directly in- teracts with dark matter the ＂interacting dark energy＂ （IDE） scenario. Actually, besides the above reasons of theoretical aspect, one should be more concerned with the observational issue： How can we detect this interaction （this is essentially a kind of ＂fifth force＂） or falsify this scenario by using the observations？ This requires us to be able to calculate how it affects the cosmological evolution, including both aspects of expansion history and growth of structure.
The limited triple‐phase boundaries (TPBs) in solid‐state cathodes (SSCs) and high resistance imposed by solid electrolytes (SEs) make the achievement of high‐performance all‐solid‐state ...lithium‐oxygen (ASS Li‐O2) batteries a challenge. Herein, an adjustable‐porosity plastic crystal electrolyte (PCE) has been fabricated by employing a thermally induced phase separation (TIPS) technique to overcome the above tricky issues. The SSC produced through the in‐situ introduction of the porous PCE on the surface of the active material, facilitates the simultaneous transfer of Li+/e−, as well as ensures fast flow of O2, forming continuous and abundant TPBs. The high Li+ conductivity, softness, and adhesion of the dense PCE significantly reduce the battery resistance to 115 Ω. As a result, the ASS Li‐O2 battery based on this adjustable‐porosity PCE exhibits superior performances with high specific capacity (5963 mAh g−1), good rate capability, and stable cycling life up to 130 cycles at 32 °C. This novel design and exciting results could open a new avenue for ASS Li‐O2 batteries.
Holey cathodes, Battman! An adjustable‐porosity plastic crystal electrolyte (PCE) has been fabricated to solve the problems of high resistance and limited triple‐phase boundaries in all‐solid‐state lithium‐oxygen (ASS Li‐O2) batteries. The ASS Li‐O2 battery with dense PCE and porous PCE‐based solid‐state cathode shows ultra‐low resistance (115 Ω), large capacity (5963 mAh g−1), good rate capability, and long cycle life (130 cycles) at 32 °C.
Lithium-ion batteries have had a tremendous impact on several sectors of our society; however, the intrinsic limitations of Li-ion chemistry limits their ability to meet the increasing demands of ...developing more advanced portable electronics, electric vehicles, and grid-scale energy storage systems. Therefore, battery chemistries beyond Li ions are being intensively investigated and need urgent breakthroughs toward commercial applications, wherein the use of metallic Li is one of the most intuitive choices. Despite several decades of oblivion due to safety concerns regarding the growth of Li dendrites, Li-metal anodes are now poised to be revived because of the advances in investigative tools and globally invested efforts. In this review, we first summarize the existing issues with regard to Li anodes and their underlying reasons and then highlight the recent progress made in the development of high-performance Li anodes. Finally, we propose the persisting challenges and opportunities toward the exploration of practical Li-metal anodes.
Lithium ion batteries cannot meet the ever increasing demands of human society. Thus batteries with Li-metal anodes are eyed to revive. Here we summarize the recent progress in developing practical Li-metal anodes for various Li-based batteries.
Weighing neutrinos in dynamical dark energy models Zhang, Xin
Science China. Physics, Mechanics & Astronomy/Science China. Physics, mechanics & astronomy,
06/2017, Volume:
60, Issue:
6
Journal Article
Peer reviewed
Open access
The discovery of neutrino oscillation indicates that neutrinos have masses and each flavor state is actually a superposition of three mass states with masses m1,m2,and m3.However,the neutrino ...oscillation experiments are not able to measure the absolute masses of neutrinos,but can only measure the squared mass differences between the neutrino mass eigenstates—The solar and reactor experiments gave
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