There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

The need to develop inexpensive renewable energy sources stimulates scientific research for efficient, low-cost photovoltaic devices.1 The organic, polymer-based photovoltaic elements have introduced at least the potential of obtaining cheap and easy methods to produce energy from light.2 The possibility of chemically manipulating the material properties of polymers (plastics) combined with a variety of easy and cheap processing techniques has made polymer-based materials present in almost every aspect of modern society.3 Organic semiconductors have several advantages: (a) lowcost synthesis, and (b) easy manufacture of thin film devices by vacuum evaporation/sublimation or solution cast or printing technologies. Furthermore, organic semiconductor thin films may show high absorption coefficients4 exceeding 105 cm-1, which makes them good chromophores for optoelectronic applications. The electronic band gap of organic semiconductors can be engineered by chemical synthesis for simple color changing of light emitting diodes (LEDs).5 Charge carrier mobilities as high as 10 cm2/V‚s6 made them competitive with amorphous silicon.7 This review is organized as follows. In the first part, we will give a general introduction to the materials, production techniques, working principles, critical parameters, and stability of the organic solar cells. In the second part, we will focus on conjugated polymer/fullerene bulk heterojunction solar cells, mainly on polyphenylenevinylene (PPV) derivatives/(1-(3-methoxycarbonyl) propyl-1-phenyl[6,6]C61) (PCBM) fullerene derivatives and poly(3-hexylthiophene) (P3HT)/PCBM systems. In the third part, we will discuss the alternative approaches such as polymer/polymer solar cells and organic/inorganic hybrid solar cells. In the fourth part, we will suggest possible routes for further improvements and finish with some conclusions. The different papers mentioned in the text have been chosen for didactical purposes and cannot reflect the chronology of the research field nor have a claim of completeness. The further interested reader is referred to the vast amount of quality papers published in this field during the past decade.

Conjugated polymer-based organic solar cells

A polymer solar-cell based on a bulk hetereojunction design with an internal quantum efficiency of over 90% across the visible spectrum (425 nm to 575 nm) is reported. The device exhibits a power-conversion efficiency of 6% under standard air-mass 1.5 global illumination tests.

Bulk heterojunction solar cells with internal quantum efficiency approaching 100

Fossil fuel alternatives, such as solar energy, are moving to the forefront in a variety of research fields. Polymer-based organic photovoltaic systems hold the promise for a cost-effective, lightweight solar energy conversion platform, which could benefit from simple solution processing of the active layer. The function of such excitonic solar cells is based on photoinduced electron transfer from a donor to an acceptor. Fullerenes have become the ubiquitous acceptors because of their high electron affinity and ability to transport charge effectively. The most effective solar cells have been made from bicontinuous polymer–fullerene composites, or so-called bulk heterojunctions. The best solar cells currently achieve an efficiency of about 5 %, thus significant advances in the fundamental understanding of the complex interplay between the active layer morphology and electronic properties are required if this technology is to find viable application.

Polymer–Fullerene Composite Solar Cells

Since hIAPP (human islet amyloid polypeptide) aggregation and microbial infection are recognized as significant risk factors that contribute to the pathogenesis of type II diabetes (T2D), targeting these catastrophic processes simultaneously may have a greater impact on the prevention and treatment of T2D. Different from the well-studied hIAPP inhibitors, here we propose and demonstrate a repurposing strategy for an antimicrobial peptide, aurein, which can simultaneously modulate hIAPP aggregation and inhibit microbial infection. Collective data from protein, cell, and bacteria assays revealed multiple functions of aurein including (i) promotion of hIAPP aggregation at a low molar ratio of aurein:hIAPP = 0.5 : 1-2 : 1, (ii) reduction of hIAPP-induced cytotoxicity in RIN-m5F cells, and (iii) preservation of original antimicrobial activity against E. coli., S.A., and S.E. strains in the presence of hIAPP. These functions of aurein are mainly derived from its strong binding to different hIAPP seeds through conformationally similar β-sheet association. Our study provides a promising avenue for the repurposing of antimicrobial peptides (such as aurein) as amyloid modulators for blocking at least two pathological pathways in T2D.

Cross-seeding enables repurposing of aurein antimicrobial peptides as a promoter of human islet amyloid polypeptide (hIAPP).

Three- and two-dimensional mixed metal halide perovskites for high-performance photovoltaics

Polymer solar cells (PSCs) with a bulk heterojunction (BHJ) device structure have incredible advantages, such as low-cost fabrication and flexibility. But, the power conversion efficiency (PCE) of BHJ PSCs needs to be further improved to realize their practical applications. In this study, we report boosted PCEs from the PSCs based on the BHJ composites incorporated with Fe3 O4 magnetic nanoparticles (MNPs) aligned by the external magnetic field (EMF). It is found that the coercive electric field within the Fe3 O4 MNPs generated by the EMF has a strong and positive influence on the charge generation, which results in a more than 10% increase in free charge carriers. Moreover, the coercive electric field speeds up the charge carrier transport and suppress charge carrier recombination within PSCs. In addition, a shortened extraction time made charge carriers more likely to make it to the electrodes. As a result, more than 15% enhancement in PCE is observed from the PSCs based on the BHJ composite incorporated with the Fe3 O4 MNPs and the EMF as compared with that based on the BHJ composite thin film. Our work indicates that the incorporation of MNPs and the EMF is a facile way to enhance the PCEs of PSCs. This article is protected by copyright. All rights reserved.

https://rss.onlinelibrary.wiley.com/doi/am-pdf/10.1002/marc.202100933

Effect of External Magnetic Field on Bulk Heterojunction Polymer Solar Cells.

A polymer solar cell includes a low temperature, solution-processed metal-oxide thin film, such as molybdenum-oxide (MoOx), as a hole-extraction layer (HEW. The low temperature processing allows the metal-oxide thin film to achieve a smoother surface, which allows the thin film to have enhanced light transparency and increased electrical conductivity over that of conventional PEDOT:PSS thin films. As such, the polymer solar cell, which utilizes the metal-oxide thin film as a hole-extraction layer, is able to achieve enhanced power conversion efficiency over conventional polymer solar cells that use PEDOT:PSS as a hole-extraction layer.

Polymer solar cell using a low-temperature, solution-processed metal-oxide thin film as a hole-extraction layer

Licht
emittierende Vorrichtung auf der Basis von organischen Polymeren,
umfassend eine Elektronen-Injektion-Elektrode und eine Loch-Injektion-Elektrode
auf gegenuberliegenden
Seiten einer emittierenden Schicht, wobei die emittierende Schicht
mindestens ein lumineszierendes erstes halbleitendes Polymer umfasst,
das zur Fluoreszenz-Emission in der Lage ist und als Wirt fur mindestens
einen zugemischten Phosphoreszenz Emitter dient, der zur Phosphoreszenz-Emission
in der Lage ist, wobei die Verbesserung mindestens eines der folgenden umfasst eine
organische Elektronen-Transport-Schicht, umfassend ein zweites halbleitendes
Polymer, das zwischen der Elektronen-Injektions-Elektrode und der
emittierenden Schicht angeordnet ist und ein niedrigstes nicht besetztes
Molekular-Orbital aufweist, mit einer Energie nahe dem unteren Ende
der π*-Bande
des lumineszierenden Polymers; und eine organische Loch-Transport-Schicht,
umfassend ein drittes halbleitendes Polymer, das zwischen der Loch-Injektions-Elektrode
und der emittierenden Schicht angeordnet ist und ein hochstes besetztes
Molekular-Orbital aufweist, mit einer Energie nahe der oberen π-Bande des
lumineszierenden Polymers.

Xiong Gong

Papers

Cross-seeding enables repurposing of aurein antimicrobial peptides as a promoter of human islet amyloid polypeptide (hIAPP).

Three- and two-dimensional mixed metal halide perovskites for high-performance photovoltaics

Effect of External Magnetic Field on Bulk Heterojunction Polymer Solar Cells.

Polymer solar cell using a low-temperature, solution-processed metal-oxide thin film as a hole-extraction layer

Mehrschichtige Licht emittierende Polymer-Diode für Festkörper Beleuchtungs-Anwendungen