The high occurrence of trapped unreactive charges due to chemical defects seriously affects the performance of g-C 3 N 4 in photocatalytic applications. This problem can be overcome by introducing ultrasmall red phosphorus (red P) crystals on g-C 3 N 4 sheets. The elemental red P atoms reduce the number of defects in the g-C 3 N 4 structure by forming new chemical bonds for much more effective charge separation. The product shows significantly enhanced photocatalytic activity toward hydrogen production. To the best of our knowledge, the hydrogen evolution rate obtained on this hybrid should be the highest among all P-containing g-C 3 N 4 photocatalysts reported so far. The trapping and detrapping processes in this red P/g-C 3 N 4 system are thoroughly revealed by using time-resolved transient absorption spectroscopy. P modification was thoroughly investigated by using timeresolved transient absorption (TA) experiments.The authors declare no conflict of interest.

Two-dimensional semiconductors can be used to build next-generation electronic devices with ultrascaled channel lengths. However, semiconductors need to be integrated with high-quality dielectrics—which are challenging to deposit. Here we show that single-crystal strontium titanate—a high-κ perovskite oxide—can be integrated with two-dimensional semiconductors using van der Waals forces. Strontium titanate thin films are grown on a sacrificial layer, lifted off and then transferred onto molybdenum disulfide and tungsten diselenide to make n-type and p-type transistors, respectively. The molybdenum disulfide transistors exhibit an on/off current ratio of 108 at a supply voltage of 1 V and a minimum subthreshold swing of 66 mV dec−1. We also show that the devices can be used to create low-power complementary metal–oxide–semiconductor inverter circuits.

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Optical tweezers (OTs) are innovative instruments utilized for the manipulation of microscopic biological objects of interest. Rapid improvements in precision and degree of freedom of multichannel and multifunctional OTs have ushered in a new era of studies in basic physical and chemical properties of living tissues and unknown biomechanics in biological processes. Nowadays, OTs are used extensively for studying living cells and have initiated far-reaching influence in various fundamental studies in life sciences. There is also a high potential for using OTs in haemorheology, investigations of blood microcirculation and the mutual interplay of blood cells. In fact, in spite of their great promise in the application of OTs-based approaches for the study of blood, cell formation and maturation in erythropoiesis have not been fully explored. In this review, the background of OTs, their state-of-the-art applications in exploring single-cell level characteristics and bio-rheological properties of mature red blood cells (RBCs) as well as the OTs-assisted studies on erythropoiesis are summarized and presented. The advance developments and future perspectives of the OTs’ application in haemorheology both for fundamental and practical in-depth studies of RBCs formation, functional diagnostics and therapeutic needs are highlighted.

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The aim of this study was to determine the main constituents of the essential oil isolated from Fortunella crassifolia Swingle peel by hydro-distillation, and to test the efficacy of the essential oil on antimicrobial activity. Twenty-five components, representing 92.36% of the total oil, were identified by GC-MS analysis. The essential oil showed potent antimicrobial activity against both Gram-negative ( E. coli and S. typhimurium ) and Gram-positive ( S. aureus , B. cereus , B. subtilis , L. bulgaricus , and B. laterosporus ) bacteria, together with a remarkable antifungal activity against C. albicans . In a food model of beef extract, the essential oil was observed to possess an effective capacity to control the total counts of viable bacteria. Furthermore, the essential oil showed strongly detrimental effects on the growth and morphological structure of the tested bacteria. It was suggested that the essential oil from Fortunella crassifolia Swingle peel might be used as a natural food preservative against bacteria or fungus in the food industry.

Nontrivial topological structures offer a rich playground in condensed matters and promise alternative device configurations for post-Moore electronics. While recently a number of polar topologies have been discovered in confined ferroelectric PbTiO3 within artificially engineered PbTiO3/SrTiO3 superlattices, little attention was paid to possible topological polar structures in SrTiO3. Here we successfully create previously unrealized polar antivortices within the SrTiO3 of PbTiO3/SrTiO3 superlattices, accomplished by carefully engineering their thicknesses guided by phase-field simulation. Field- and thermal-induced Kosterlitz–Thouless-like topological phase transitions have also been demonstrated, and it was discovered that the driving force for antivortex formation is electrostatic instead of elastic. This work completes an important missing link in polar topologies, expands the reaches of topological structures, and offers insight into searching and manipulating polar textures.

Photoinduced electron transfer based fluorescence correlation spectroscopy (PET-FCS) is a powerful tool to study biomolecular processes. However, some questions remain as to how to correctly interpret the PET-FCS data. In this work, we studied the PET process between tetramethylrhodamine and guanosine by means of femtosecond transient absorption spectroscopy. We derived that the charge separation rate is 4.1 × 10(9) s(-1) and the charge recombination rate is 5.2 × 10(10) s(-1) for the current system, supporting the three-state model and the interpretation on PET-FCS experiments given by Qu et al. (J. Phys Chem. B, 2010, 114, 8235). At the limit that both the charge separation and recombination rates are much faster than the process that PET-FCS reveals, the three-state model can be simplified to an equivalent two-state model with a dark state whose brightness is nonzero. We propose ways to obtain the brightness of the dark state with additional experiments, which is necessary for a PET-FCS study.