Gene Expression during the Activation of Human B Cells

Human B lymphocytes not only play a critical role in the humoral immunity to generate antibodies, but also are equally important to cellular immunity as B lymphocytes can present antigens to T lymphocytes and can release a range of potential immune-regulating cytokines after stimulations. Human immunoglobulin class switch recombination (CSR) in activated B cells is an essential process in the humoral immunity and the process is complicated and tightly controlled by many regulators. The recent genomic and genetic approaches in CSR identified novel genes that were actively involved in the process. Understanding the roles of the novel genes in CSR will bring new insights into the mechanisms of the process and new potential therapeutic targets for immunoglobulin-related disorders such as allergic asthma and autoimmune diseases

Recent Advances of ZnO-Based Perovskite Solar Cell

Perovskite solar cells (PSCs) have developed rapidly over the past few years, and the power conversion efficiency (PCE) of PSCs has exceeded 25%. It has the characteristics of low cost, high efficiency, simple process and so on, and hence has a good development prospect. Due to the difference in electrons and holes diffusion lengths, electron transporting materials (ETMs) play a crucial role in the performance of PSCs. ZnO electron transport layer (ETL) has the advantages of high electron mobility, high transmittance, suitable energy level matching with neighbor layer in PSCs, low temperature preparation and environmental friendliness, so it has become the main application material of electron transport layer in perovskite solar cells. In this review, the application of ZnO-ETMs in PSCs in recent years is reviewed, and the effect of ZnO-ETMs on the performance of PSCs is also introduced. Finally, the limitations of ZnO-ETMs based PSCs and the methods to solve these problems are discussed, and the development prospect of PSCs is prospected

On linear-algebraic notions of expansion

A fundamental fact about bounded-degree graph expanders is that three notions of expansion -- vertex expansion, edge expansion, and spectral expansion -- are all equivalent. In this paper, we study to what extent such a statement is true for linear-algebraic notions of expansion. There are two well-studied notions of linear-algebraic expansion, namely dimension expansion (defined in analogy to graph vertex expansion) and quantum expansion (defined in analogy to graph spectral expansion). Lubotzky and Zelmanov proved that the latter implies the former. We prove that the converse is false: there are dimension expanders which are not quantum expanders. Moreover, this asymmetry is explained by the fact that there are two distinct linear-algebraic analogues of graph edge expansion. The first of these is quantum edge expansion, which was introduced by Hastings, and which he proved to be equivalent to quantum expansion. We introduce a new notion, termed dimension edge expansion, which we prove is equivalent to dimension expansion and which is implied by quantum edge expansion. Thus, the separation above is implied by a finer one: dimension edge expansion is strictly weaker than quantum edge expansion. This new notion also leads to a new, more modular proof of the Lubotzky--Zelmanov result that quantum expanders are dimension expanders.Comment: 23 pages, 1 figur