Comparative study on microstructure and surface properties of keratin- and lignocellulosic-based activated carbons

© 2015 Elsevier B.V. All rights reserved. The paper probed the preparation of activated carbon by potassium silicate (K2SiO3) activation from keratin waste (cowhair waste, CW) and lignocellulosic materials (Cyperus alternifolius, CA) and the comparisons of physicochemical properties of the resulting carbons. These impregnation conditions were as follows: one impregnated at room temperature for 12 h then dipped at high temperature for 30 min; the other was only impregnated at room temperature for 12 h, producing four activated carbons CWAC-1, CWAC-2, CAAC-1, and CAAC-2. The influence of activation time, K2SiO3/precursor weight ratio, and the pre-process on properties of activated carbons was discussed. The CWAC-1 produced at 700°C with the K2SiO3/precursor weight ratio of 2:1 possessed the Brunauer-Emmet-Teller (BET) surface area of 1965 m2/g and total pore volume of 1.345 cm3/g, while CAAC-1 prepared at the same conditions attained the BET surface area of 1710 m2/g and total pore volume of 0.949 cm3/g. The surface area and total pore volume of CAAC increased with the impregnation ratio. Moreover, CWAC-1, CWAC-2, CAAC-1, and CAAC-2 exhibited high portion of micropores, illustrating the role of K2SiO3. The analysis with a Fourier transform infrared spectrometer indicates that CWAC has more functional groups than CAAC, as well as CWAC-1 and CWAC-2 which possess similar functional groups

Beyond Immune Balance: The Pivotal Role of Decidual Regulatory T Cells in Unexplained Recurrent Spontaneous Abortion

Qing-Hui Li,1,2 Qiu-Yan Zhao,1 Wei-Jing Yang,1 Ai-Fang Jiang,2 Chun-E Ren,2 Yu-Han Meng2 1School of Clinical Medicine, Shandong Second Medical University, Weifang, Shandong, 261021, People’s Republic of China; 2Center of Reproductive Medicine, Affiliated Hospital of Shandong Second Medical University, Weifang, Shandong, 261000, People’s Republic of ChinaCorrespondence: Yu-Han Meng, Center of Reproductive Medicine, Affiliated Hospital of Shandong Second Medical University, No. 2428.Yuhe Road, Kuiwen District, Weifang, Shandong, 261031, People’s Republic of China, Tel/Fax +86 536-3081389, Email [email protected]: Recurrent spontaneous abortion (RSA) is defined as two or more consecutive pregnancy failures, which brings tremendous stress to women of childbearing age and seriously affects family well-being. However, the reason in about 50% of cases remains unknown and is defined as unexplained recurrent spontaneous abortion (URSA). The immunological perspective in URSA has attracted widespread attention in recent years. The embryo is regarded as a semi-allogeneic graft to the mother. A successful pregnancy requires transition to an immune environment conducive to embryo survival at the maternal–fetal interface. As an important member of regulatory immunity, regulatory T (Treg) cells play a key role in regulating immune tolerance at the maternal–fetal interface. This review will focus on the phenotypic plasticity and lineage stability of Treg cells to illustrate its relationship with URSA.Keywords: immune homeostasis, Treg cells, phenotype, maternal–fetal toleranc

Superconductivity at the Border of Electron Localization and Itinerancy

The superconducting state of iron pnictides and chalcogenides exists at the border of antiferromagnetic order. Consequently, these materials could provide clues about the relationship between magnetism and unconventional superconductivity. One explanation, motivated by the so-called bad-metal behaviour of these materials, proposes that magnetism and superconductivity develop out of quasi-localized magnetic moments which are generated by strong electron-electron correlations. Another suggests that these phenomena are the result of weakly interacting electron states that lie on nested Fermi surfaces. Here we address the issue by comparing the newly discovered alkaline iron selenide superconductors, which exhibit no Fermi-surface nesting, to their iron pnictide counterparts. We show that the strong-coupling approach leads to similar pairing amplitudes in these materials, despite their different Fermi surfaces. We also find that the pairing amplitudes are largest at the boundary between electronic localization and itinerancy, suggesting that new superconductors might be found in materials with similar characteristics.Comment: Version of the published manuscript prior to final journal-editting. Main text (23 pages, 4 figures) + Supplementary Information (14 pages, 7 figures, 3 tables). Calculation on the single-layer FeSe is added. Enhancement of the pairing amplitude in the vicinity of the Mott transition is highlighted. Published version is at http://www.nature.com/ncomms/2013/131115/ncomms3783/full/ncomms3783.htm

Electronic Origin of High Temperature Superconductivity in Single-Layer FeSe Superconductor

The latest discovery of high temperature superconductivity signature in single-layer FeSe is significant because it is possible to break the superconducting critical temperature ceiling (maximum Tc~55 K) that has been stagnant since the discovery of Fe-based superconductivity in 2008. It also blows the superconductivity community by surprise because such a high Tc is unexpected in FeSe system with the bulk FeSe exhibiting a Tc at only 8 K at ambient pressure which can be enhanced to 38 K under high pressure. The Tc is still unusually high even considering the newly-discovered intercalated FeSe system A_xFe_{2-y}Se_2 (A=K, Cs, Rb and Tl) with a Tc at 32 K at ambient pressure and possible Tc near 48 K under high pressure. Particularly interesting is that such a high temperature superconductivity occurs in a single-layer FeSe system that is considered as a key building block of the Fe-based superconductors. Understanding the origin of high temperature superconductivity in such a strictly two-dimensional FeSe system is crucial to understanding the superconductivity mechanism in Fe-based superconductors in particular, and providing key insights on how to achieve high temperature superconductivity in general. Here we report distinct electronic structure associated with the single-layer FeSe superconductor. Its Fermi surface topology is different from other Fe-based superconductors; it consists only of electron pockets near the zone corner without indication of any Fermi surface around the zone center. Our observation of large and nearly isotropic superconducting gap in this strictly two-dimensional system rules out existence of node in the superconducting gap. These results have provided an unambiguous case that such a unique electronic structure is favorable for realizing high temperature superconductivity

Formation of P In defect in annealed liquid-encapsulated Czochralski InP

Fourier transform infrared spectroscopy measurements have been carried out on liquid-encapsulated Czochralski-grown undoped InP wafers, which reproducibly become semi-insulating upon annealing in an ambient of phosphorus at 800-900°C. The measurements reveal a high concentration of hydrogen complexes in the form V InH 4 existing in the material before annealing in agreement with recent experimental studies. It is argued that the dominant and essential process producing the semi-insulating behavior is the compensation produced by an EL 2-like deep donor phosphorus antisite defect, which is formed by the dissociation of the hydrogen complexes during the process of annealing. The deep donor compensates acceptors, the majority of which are shallow residual acceptor impurities and deep hydrogen associated V In and isolated V In levels, produced at the first stage of the dissociation of the V InH 4 complex. The high concentration of indium vacancies produced by the dissociation are the precursor of the EL 2-like phosphorus antisite. These results show the importance of hydrogen on the electrical properties of InP and indicate that this largely results from low formation energy of the complex V InH 4 in comparison with that of an isolated V In. © 1998 American Institute of Physics.published_or_final_versio

Adaptive Sliding Mode Control of Lateral Stability of Four Wheel Hub Electric Vehicles

Some physical parameters of a hub motor-driven four-wheel electric vehicle will change when the vehicle turns or maneuvers and the parameter change is caused by the change of the driving conditions. An adaptive sliding mode control is proposed in this paper to maintain the vehicle’s stability by compensating for the change of these parameters. The control parameter being adapted is the converging rate of the system state towards the sliding mode. As the Lyapunov method is used, so both the vehicle stability and adaptive rate convergence are guaranteed. Moreover, the hierarchical control structure is adopted for this vehicle stability control system. The above adaptive sliding model control forms the upper-layer; while the lower-layer control is to distribute the upper torque to the four wheels in an optimal way, subject to several constraints. In addition, the best feasible reference of the yaw rate and the vehicle side slip angle are obtained and used in the control system. The developed method is simulated under the CarSim/MATLAB co-simulation environment to evaluate the system performance. The simulation results are compared with the non-adaptive existing sliding mode control, and show that the proposed method is superior under different conditions. © 2020, KSAE

Histone Acetylation-Mediated Regulation of the Hippo Pathway

The Hippo pathway is a signaling cascade recently found to play a key role in tumorigenesis therefore understanding the mechanisms that regulate it should open new opportunities for cancer treatment. Available data indicate that this pathway is controlled by signals from cell-cell junctions however the potential role of nuclear regulation has not yet been described. Here we set out to verify this possibility and define putative mechanism(s) by which it might occur. By using a luciferase reporter of the Hippo pathway, we measured the effects of different nuclear targeting drugs and found that chromatin-modifying agents, and to a lesser extent certain DNA damaging drugs, strongly induced activity of the reporter. This effect was not mediated by upstream core components (i.e. Mst, Lats) of the Hippo pathway, but through enhanced levels of the Hippo transducer TAZ. Investigation of the underlying mechanism led to the finding that cancer cell exposure to histone deacetylase inhibitors induced secretion of growth factors and cytokines, which in turn activate Akt and inhibit the GSK3 beta associated protein degradation complex in drug-affected as well as in their neighboring cells. Consequently, expression of EMT genes, cell migration and resistance to therapy were induced. These processes were suppressed by using pyrvinium, a recently described small molecule activator of the GSK 3 beta associated degradation complex. Overall, these findings shed light on a previously unrecognized phenomenon by which certain anti-cancer agents may paradoxically promote tumor progression by facilitating stabilization of the Hippo transducer TAZ and inducing cancer cell migration and resistance to therapy. Pharmacological targeting of the GSK3 beta associated degradation complex may thus represent a unique approach to treat cancer. © 2013 Basu et al