A simulation study of protons heated by left/right-handed Alfvén waves generated by electromagnetic proton-proton instability

Most protons in the solar wind belong to one of two different populations,the less dense beam protons and the denser core protons.The beam protons,with a velocity of(1-2)VA(VA is the local Alfvén speed),always drift relative to the core protons;this kind of distribution is unstable and stimulates several kinds of wave mode.In this study,using a 2D hybrid simulation model,we find that the original right-handed elliptically polarized Alfvén waves become linearly polarized,and eventually become right-handed and circularly polarized.Given that linearly polarized waves are a superposition of left-handed and right-handed waves,cyclotron resonance in the right-handed/left-handed component heats beam/core protons perpendicularly.The resonance between beam protons and right-handed polarized waves is stronger when the beam relative density is lower,resulting in more dramatic perpendicular heating of beam protons,whereas the situation is reversed when the beam relative density is larger.     

K–I co-doped crystalline carbon nitride with outstanding visible light photocatalytic activity for H2 evolution

Heteroatomic doping is an effective way to optimize the electronic structure of carbon nitride to boost photocatalytic performance. However, the extra introduced defects could result in the decrease of its crystallinity. In this work, crystalline K–I co-doped carbon nitride (K–I–CCN) was simply synthesized from molten salt ionthermal post-calcination in nitrogen atmosphere. Structure characterization results indicate that compared to K–CCN synthesized from conventional molten salt heat treatment in air, nitrogen heating atmosphere is more conductive for the formation of homogeneous pore structure of the catalyst, which has larger surface area and pore volume, while could repairing some defects and resulting in better polymerization crystallization. In addition, except the implanting of K, I doping is still retained after nitrogen heat treatment, thus forming K–I co-doping structure. Due to the positive charge effect of K–I co-doping, K–I–CCN has a narrower band gap, higher surface charge density and stronger charge transport, so it performs significantly enhanced photocatalytic H₂ evolution activity from water splitting.     

The status of and opportunities for utility-scale battery storage in Australia: A regulatory and market perspective

Australia's electricity market is rapidly adding renewable energy generation. Utility-scale batteries could have a major role in facilitating these transitions; however, their deployment is still largely state-subsidized. We summarize the current and future roles for batteries from a legal-economic perspective in the context of Australia's electricity market framework. We find that the future of batteries in Australia is not only a function of the large-scale deployment of renewables, their cost development and the comparative future cost of competing gas turbines but also of national electricity market and state policy reforms focusing on reliability.     

萝卜硫素介导Akt/p70S6K信号传导诱导人鼻咽癌CNE-2细胞凋亡

目的:研究萝卜硫素对人鼻咽癌CNE-2细胞增殖、凋亡的影响及其对Akt/p70S6K信号传导的作用。方法:采用CCK-8实验分析萝卜硫素对CNE-2细胞生长增殖的影响，流式细胞仪检测萝卜硫素对CNE-2细胞凋亡率及细胞周期分布的影响，Western blot技术检测CNE-2细胞中调控细胞周期的相关蛋白及Akt/p70S6K信号通路关键蛋白的表达水平。结果:采用萝卜硫素干预CNE-2细胞后，细胞增殖抑制率及凋亡率相对于对照组呈浓度依赖的方式显著增高，差异有统计学意义（P<0.05）；流式细胞仪分析提示，萝卜硫素干预能够将细胞停留在S期及G2/M期，并且萝卜硫素还能抑制细胞周期蛋白Cyclin A、Cyclin B、Cyclin D、Cyclin E以及CDK/p34的表达水平，与对照组相比差异有统计学意义（P<0.05）；此外，萝卜硫素还能抑制Akt/p70S6K信号通路关键蛋白p-Akt及p70S6K蛋白表达水平（P<0.05），但萝卜硫素与Akt激动剂IGF-I共同处理细胞后，上述蛋白表达量与对照组相比没有统计学差异（P>0.05）。结论:萝卜硫素可能通过干扰CNE-2细胞中Akt/p70S6K信号传导而发挥有效的抗增殖及促凋亡的作用。     

混流式水泵水轮机轴向水推力计算方法

混流式水泵水轮机的轴向水推力对机组的结构设计和安全运行影响重大,但关于水推力精确计算的研究较少。对此,首先理论上阐释了轴向水推力的组成成分并进行各成分的机理分析。依靠CFD分析技术和相关测试技术进一步对某混流式蓄能机组的轴向水推力进行了数值计算和两个方案的现场测试,经过相互分析验证比较,最终掌握了混流式水泵水轮机轴向水推力的变化规律并提供了一种较为准确的计算方法。研究成果为深入分析奠定了基础。     

PI3K/AKT/GSK3β信号通路参与腺苷A1R介导异丙酚对缺血再灌注损伤大鼠的脑保护作用

目的：探讨PI3K/AKT/GSK-3β信号通路参与异丙酚对缺血再灌注损伤大鼠的脑保护作用及机制。方法：健康雄性SD大鼠72只，所有大鼠参照Zea Longa法建立局灶性脑缺血再灌注损伤的模型。随机分成6组（n=12），A-假手术组，B-模型组（MCAO），C-异丙酚组，D-异丙酚+腺苷A1R拮抗剂组（DPCPX），E-异丙酚组+PI3K特异性抑制剂（LY294002），F-异丙酚+GSK-3β抑制剂组（SB216763），观察大鼠术后24 h神经功能评分情况；LDF监测插栓前后脑血流变化；采用TTC染色法检测各组大鼠的脑梗死体积；用HE染色方法观察大鼠脑组织形态学改变；免疫组织化学法检测Bcl-2阳性细胞表达；采用TUNEL检测各组大脑脑皮质缺血周围神经元凋亡细胞的百分率。结果：与A组比较，B、C、D、E及F组大鼠行为学、脑梗死体积、细胞凋亡率、Bcl-2蛋白表达量均增加（P<0.05）；与C组比较，B、D、E组大鼠行为学评分，脑梗死体积及细胞凋亡率均明显增加，Bcl-2蛋白表达量均明显减少（P<0.01），F组Bcl-2蛋白表达量却增加，细胞凋亡率降低（P<0.05），行为学评分减少、梗死体积减少（P<0.05）。 结论：腺苷A1R介导的异丙酚对缺血再灌注损伤大鼠的神经保护作用可能与PI3K/AKT/GSK-3β信号转导通路有关。     

Anti-proliferative effects of a small molecule inhibitor of CDK AT7519 on chronic myeloid leukemia (CML) cells through halting the transition of cells from G2/M phase of the cell cycle

Pathogenesis of chronic myeloid leukemia (CML) has mostly been studied with regard to the oncogenic role of BCR/ABL fusion; however, recent disclosures have declared that the challenges with the treatment of CML patients would not be resolved until the role of other aberrancies is ignored. Given the involvement of cyclin-dependent kinases (CDKs) in the pathogenesis of CML, the present study aimed to investigate the effects of a multi-CDK inhibitor AT7519 on BCR/ABL-harboring CML-derived K562 cells. Our results showed that AT7519 effectively reduced the survival of K562 and induced its anti-proliferative effect through the induction of G2/M arrest due to elevated p21 and p27. The resulting data also revealed that either direct or indirect suppression of c-Myc using specific c-Myc inhibitor 10058-F4 and selective PI3K inhibitor CAL-101 resulted in a superior cytotoxicity, suggesting that the activation of PI3K pathway could attenuate antileukemic effects of the inhibitor, at least partly, through a c-Mycdependent mechanism. To the best of our knowledge, to date, no study has addressed the effect of autophagy on CML cell response to AT7519, and, herein, we proposed for the first time that the suppression of autophagy boosted AT7519 cytotoxicity against K562. Overall, we suggested that selective CDK inhibitor AT7519 exerted antileukemic effect against CML cells and propose a novel therapeutic application for the inhibitor either as a single agent or in combination with c-Myc and/or PI3K inhibitors.     

Microwave dielectric properties of SrLa[Ga1−x(Mg0.5Ti0.5)x]O4 and SrLa[Ga1−x(Zn0.5Ti0.5)x]O4 (x = 0.2-0.8) ceramics

SrLa[Ga_1−x(R_0.5Ti_0.5)_x]O₄ (R = Mg, Zn) ceramics were prepared by a standard solid state sintering method. The single-phase ceramics with K₂NiF₄-type layered perovskite structure and I4/mmm space group were obtained, indicating that SrLa(R_0.5Ti_0.5) and SrLaGaO₄ can form the unlimited solid solutions. With increasing x for R = Mg and Zn, ε_r increases monotonously, the Qf value first increases and then decreases, while τ_f increases from a negative to a positive value. The optimized microwave dielectric properties were obtained as following: ε_r = 23.3, Qf = 89 400 GHz, τ_f = −0.8 ppm/°C for SrLa[Ga_0.6(Mg_0.5Ti_0.5)_0.4]O₄ and ε_r = 23.3, Qf = 76 200 GHz, τ_f = 0.2 ppm/°C for SrLa[Ga_0.7(Zn_0.5Ti_0.5)_0.3]O₄, indicating that the present solid solution ceramics are the promising candidates as microwave resonator materials for the telecommunication applications.     

基于红曲高产莫纳可林K的固态发酵工艺条件优化

利用响应面法优化红曲固态发酵产莫纳可林K的工艺条件。在采用变温发酵,发酵时间固定的条件下,单因素试验研究接种量、装料量、玉米粉添加量和蛋白胨添加量等4个因素对红曲固态发酵莫纳可林K产量的影响。在此基础上,应用Design-Expert软件建立数学模型,进行四因素三水平的响应面分析。结果表明,红曲固态发酵高产莫纳可林K工艺条件为接种量17.50%,装料量32.95 g/250 mL、玉米粉添加量3.80%和蛋白胨添加量2.37%。此条件下进行验证试验,莫纳可林K产量为11.25 mg/g,与回归方程预测值无显著差异,说明该法优化红曲固态发酵过程中莫纳可林K的产量可行。