Research on two-dimensional (2D) materials has been explosively increasing in last seventeen years in varying subjects including condensed matter physics, electronic engineering, materials science, and chemistry since the mechanical exfoliation of graphene in 2004. Starting from graphene, 2D materials now have become a big family with numerous members and diverse categories. The unique structural features and physicochemical properties of 2D materials make them one class of the most appealing candidates for a wide range of potential applications.In particular, we have seen some major breakthroughs made in the field of 2D materials in last five years not only in developing novel synthetic methods and exploring new structures/properties but also in identifying innovative applications and pushing forward commercialisation. In this review, we provide a critical summary on the recent progress made in the field of 2D materials with a particular focus on last five years. After a brief background 物理化学学报 Acta Phys. -Chim. Sin. 2021, 37 (12), 2108017 (3 of 151) introduction, we first discuss the major synthetic methods for 2D materials, including the mechanical exfoliation, liquid exfoliation, vapor phase deposition, and wet-chemical synthesis as well as phase engineering of 2D materials belonging to the field of phase engineering of nanomaterials (PEN). We then introduce the superconducting/optical/magnetic properties and chirality of 2D materials along with newly emerging magic angle 2D superlattices. Following that, the promising applications of 2D materials in electronics, optoelectronics, catalysis, energy storage, solar cells, biomedicine, sensors, environments, etc. are described sequentially. Thereafter, we present the theoretic calculations and simulations of 2D materials. Finally, after concluding the current progress, we provide some personal discussions on the existing challenges and future outlooks in this rapidly developing field.

For many liver malignancies, major hepatectomy is the usual therapy. Although a normal liver has a tremendous capacity for regeneration, liver hepatectomy in humans is usually carried out on a diseased liver and, in such cases, liver regeneration takes place in a cirrhotic remnant. Mitochondrial function in cirrhotic livers shows a variety of changes compared to control livers. This study investigated how mitochondrial respiratory function and antioxidant capacity change following partial hepatectomy of cirrhotic livers, because liver regeneration requires greater energy demands and control of oxidative stress. Cirrhosis was induced in male Wistar-Furth rats by administration of thioacetamide. NADH-cytochrome c reductase activity, mitochondrial glutathione peroxidase activity and mitochondrial GSH levels were all significantly lowered in cirrhotic livers and in the cirrhotic remnants up to 72 h after 70% hepatectomy when compared to the corresponding controls. Lower respiratory control ratios with succinate as substrate were also observed from 6 to 48 h post-hepatectomy. At 24 h post-hepatectomy, higher levels of lipid peroxidation were observed. We conclude that, compared to the controls, cirrhotic livers have diminished oxidative phosphorylation capabilities due to changes in NADH and FADH(2)-linked respiration as well as impaired antioxidant defenses following partial hepatectomy. Both of these factors, if critical, could then impede liver regeneration.

Complex correlated states emerging from many-body interactions between quasiparticles (electrons, excitons and phonons) are at the core of condensed matter physics and material science. In low-dimensional materials, quantum confinement affects the electronic, and subsequently, optical properties for these correlated states. Here, by combining photoluminescence, optical reflection measurements and ab initio theoretical calculations, we demonstrate an unconventional excitonic state and its bound phonon sideband in layered silicon diphosphide (SiP2), where the bound electron–hole pair is composed of electrons confined within one-dimensional phosphorus–phosphorus chains and holes extended in two-dimensional SiP2 layers. The excitonic state and emergent phonon sideband show linear dichroism and large energy redshifts with increasing temperature. Our ab initio many-body calculations confirm that the observed phonon sideband results from the correlated interaction between excitons and optical phonons. With these results, we propose layered SiP2 as a platform for the study of excitonic physics and many-particle effects.

Saliva eosinophil cationic protein (ECP) is higher in asthmatic adults than in healthy ones. However, its relationship with asthma severity, other atopic conditions and allergic sensitization have not been reported. Saliva collection is painless, readily acceptable to children and parents, and can be a potentially useful body fluid to measure asthma biomarkers. We recruited 102 physician-diagnosed young asthmatic subjects from outpatient clinics with change in FEV(1) > or = 12% with inhaled salbutamol and collected data on asthma severity, concurrent allergic rhinitis (AR) and atopic dermatitis (AD), and medication used (bronchodilator and corticosteroid). We measured whole saliva and serum ECP and performed skin prick tests (SPT) for three dust mites (Dermatophagoides pteronyssisinus, Dermatophagoides farinae and Blomia tropicalis) and two cockroaches (Periplaneta americana and Blatella germanica). Median salivary ECP was 84.6 microg/l (inter-quartile range [IQR]: 40.9-147.9) and median serum ECP was 14.7 microg/l (IQR: 6.4-32.1). Serum ECP was only higher in children whose sleep was disturbed by asthma in the past year than those who were not (geometric mean [GM]: 18.9 vs. 11.1 microg/l, relative mean difference [RMD]: 1.71 [95%CI: 1.09-2.69]). Serum ECP was increased among asthmatic children on inhaled corticosteroid than those not using them (GM: 15.6 vs. 8.1 microg/l, RMD: 1.93 [95%CI: 1.11-3.39]). Salivary ECP was not associated with asthma severity, concurrence of atopic conditions, medications used, or any SPT parameter. Saliva ECP did not correlate with serum ECP (r(s) = 0.032, p = 0.790). Salivary and serum ECP did not correlate with wheal size for any skin prick test.

It is probably not feasible to use saliva as a replacement for blood for the measurement of AChE levels. This is because of the much lower levels of AChE in saliva relative to erythrocytes, the weak correlation between the two measurements and the previously reported high intra-individual variation of salivary AChE.