Mammalian oocytes not fertilized immediately after ovulation can undergo ageing and a rapid decline in quality. The addition of antioxidants can be an efficient approach to delaying the oocyte ageing process. Onion peel extract (OPE) contains quercetin and other flavonoids with natural antioxidant activities. In this study, we investigated the effect of OPE on mouse oocyte ageing and its mechanism of action. The oocytes were aged in vitro in M16 medium for 16 h after adding OPE at different concentrations (0, 50, 100, 200, and 500 μg/ml). The addition of 100 μg/ml OPE reduced the oocyte fragmentation rate, decreased the reactive oxygen species (ROS) level, increased the glutathione (GSH) level, and improved the mitochondrial membrane potential compared with the control group. The addition of OPE also increased the expression of SOD1, CAT, and GPX3 genes, and the caspase-3 activity in OPE-treated aged oocytes was significantly lower than that in untreated aged oocytes and similar to that in fresh oocytes. These results indicated that OPE delayed mouse oocyte ageing by reducing oxidative stress and apoptosis and enhancing mitochondrial function.

We simulated the motions and interactions of circular squirmers under gravity in a two-dimensional channel at finite fluid inertia, aiming to provide a comprehensive analysis of the dynamic features of swimming microorganisms or engineered microswimmers. In addition to a squirmer-type factor (β), another control parameter (α) was introduced, representing ratio of the self-propelling strength to the sedimentation strength of squirmers. Simulations were performed at 0.4 ≤ α ≤ 1.2 and −5 ≤ β ≤ 5. We first considered the sedimentation of a single squirmer. Five patterns were revealed, depending on both α and β: steady downward falling, steady inclined falling or rising and small-scale or large-scale oscillating. Compared with a pusher (β < 0, gaining thrust from rear), a puller (β > 0, gaining thrust from front) is more likely to break down its symmetrical structure and subsequently lose stability, owing to the high-pressure regions on its lateral sides. Typically, a pusher settles faster than a puller, whereas a neutral squirmer (β = 0) settles in between. This is related to the ‘trailing negative flow’ behind a pusher and ‘leading negative flow’ before a puller. We then placed two squirmers in line with the gravity direction to study their interactions. Results show pullers attract each other and come into contact as a result of the low-pressure regions between them, whereas the opposite is observed for pushers. The interactions between two pullers are illustrated by their respective patterns. In contrast, pushers never come into contact and maintain distance from each other with increasing separation. We finally examined how a puller interacts with a pusher.

The staining procedure is critical for investigating intra- and extra-cellular ultrastructure of microorganisms by transmission electron microscopy (TEM). Here, we propose a new ultra-low lead staining (ULLS) technique for preparing the ultrathin sections for TEM analysis. Sections of Enterobacter sp. (bacteria), Aspergillus niger (filamentous fungi), Rhodotorula mucilaginosa (fungi), and Chlamydomonas reinhardtii (microalgae) were tested. Compared with the sections prepared by the typical double-staining technique, ULLS-based sections showed evident advantages: (i) the staining process only required the addition of Pb(NO3)2; (ii) the Pb level during incubation was set as low as 1 mg/L, which had negligible toxicity to most microbial cells; (iii) the Pb cations were added during microbial culture, which avoided complicated sample preparation as in typical double staining. Taking C. reinhardtii as an example, the ULLS technique allowed fine investigation of microbial ultrastructure, e.g., starch granule, mitochondrion, Golgi apparatus, vacuole, and vesicle. Meanwhile, the physiological processes of the cells such as cell lysis and exocytosis were successfully captured, with relatively high contrast. This study hence shows a bright future on preparation of the high-quality ultrathin sections of microbial cells by the ULLS technique.

This article presents a brief review of our case studies of data-driven Integrated Computational Materials Engineering (ICME) for intelligently discovering advanced structural metal materials, including light-weight materials (Ti, Mg, and Al alloys), refractory high-entropy alloys, and superalloys. The basic bonding in terms of topology and electronic structures is recommended to be considered as the building blocks/units constructing the microstructures of advanced materials. It is highlighted that the bonding charge density could not only provide an atomic and electronic insight into the physical nature of chemical bond of materials but also reveal the fundamental strengthening/embrittlement mechanisms and the local phase transformations of planar defects, paving a path in accelerating the development of advanced metal materials via interfacial engineering. Perspectives on the knowledge-based modeling/simulations, machine-learning knowledge base, platform, and next-generation workforce for sustainable ecosystem of ICME are highlighted, thus to call for more duty on the developments of advanced structural metal materials and enhancement of research productivity and collaboration.

Identifying the relative importance of urban and non-urban land-use types for potential denitrification derived N2O at a regional scale is critical for quantifying the impacts of human activities on nitrous oxide (N2O) emission under changing environments. In this study we used a regional dataset from China including 197 soil samples and six land-use types to evaluate the main predictors (land use, heavy metals, soil pH, soil moisture, substrate availability, functional and broad microbial abundances) of potential denitrification using multivariate and pathway analysis. Our results provide empirical evidence that soils on farms have the greatest potential denitrifying ability (PDA) (10.92±6.08ng N2O-N·g–1 dry soil·min–1) followed by urban soil (6.80±5.35ng N2O-N·g–1 dry soil·min–1). Our models indicate that land use (low vs. high human activity), followed by total nitrogen (TN) and heavy metals (Cu, Zn, Pb, Cd) was the most important driver of PDA. In addition, our path analysis suggests that at least part of the impacts of land use on potential denitrification were mediated via microbial abundance, soil pH and substrates including TN, dissolved organic carbon and nitrate. This study identifies the main predictors of denitrification at a regional scale which is needed to quantify the impact of human activities on ecosystem functionality under changing conditions.

Previous studies have suggested that vitamin E (VE) may affect bone health, but the findings have been inconclusive. We examined the relationship between VE status (in both diet and serum) and bone mineral density (BMD) among Chinese adults. This community-based study included 3203 adults (2178 women and 1025 men) aged 40–75 years from Guangzhou, People’s Republic of China. General and dietary intake information were collected using structured questionnaire interviews. The serum α-tocopherol (TF) level was quantified by reversed-phase HPLC. The BMD of the whole body, the lumbar spine and left hip sites (total, neck, trochanter, intertrochanter and Ward’s triangle) were measured using dual-energy X-ray absorptiometry. In women, the dietary intake of VE was significantly and positively associated with BMD at the lumbar spine, total hip, intertrochanter and femur neck sites after adjusting for covariates (Ptrend: 0·001–0·017). Women in quartile 3 of VE intake typically had the highest BMD; the covariate-adjusted mean BMD were 2·5, 3·06, 3·41 and 3·54 % higher, respectively, in quartile 3 (v. 1) at the four above-mentioned sites. Similar positive associations were observed between cholesterol-adjusted serum α-TF levels and BMD at each of the studied bone sites (Ptrend: 0·001–0·022). The covariate-adjusted mean BMD were 1·24–4·83 % greater in quartile 4 (v. 1) in women. However, no significant associations were seen between the VE levels (dietary or serum) and the BMD at any site in men. In conclusion, greater consumption and higher serum levels of VE are associated with greater BMD in Chinese women but not in Chinese men.

The Shuidonggou site cluster in northern China contains 12 different early prehistoric sequences with great potential to cast light on the transition to Upper Palaeolithic behaviour in East Asia. Here researchers present the latest results from Locality 2, reporting seven occupation levels with hearths, animal bone and diverse industries. Although previously compared with European Upper Palaeolithic sequences, the new work proposes a different trajectory of development. Distinctive macroblade technology arrived in the area, possibly from Mongolia or Siberia, about 41000–34000 years ago. This industry subsequently disappeared, to be replaced by flake technologies.

This article focuses on advances in both basic and applied research on soybean germplasm resources collected from China and dispersed to the world. Many landraces developed over the course of the 4500 years since its domestication in the Huangdi period. Systematic germplasm collection was begun in the early 20th century by Professor Shou Wang, and since then over 170,000 accessions have been conserved worldwide. Evaluation with respect to key morphological characteristics, pest resistance, abiotic stress tolerance and nutritional quality attributes has been widely carried out. In addition, genetic diversity has been assessed at the DNA level, and used to establish core collections for both cultivated (Glycine max) and wild (Glycine soja) soybean. Some core sets have targeted the most used parental lines, and others have focused on specific traits, such as resistance to the soybean cyst nematode or to soybean mosaic virus, or enhanced phosphorus use efficiency. The recent acquisition of the soybean genome sequence should accelerate the utilization of not only the Chinese soybean germplasm collection, but also those maintained elsewhere in the world.

We have employed a simple and novel solution processing method to prepare V2O5-WO3 composite films which demonstrate enhanced Li-ion intercalation properties for applications in lithium-ion batteries. It should be noted that this solution processing method employs precursors that only contain the elements of V, W, O and H, which avoids impurity elements such as Na that has been commonly used in other solution methods. The V2O5-WO3 composite films show enhanced Li-ion intercalation properties compared to pure V2O5 and WO3 films. For example, V2O5-WO3 film with a molar ratio V2O5/WO3 of 10/1 exhibits a discharge capacity of 254 mA•h/g, while the pure V2O5 film delivers a discharge capacity of 76 mA•h/g at a high current density of 1.33 A/g. Such enhanced Li-ion intercalation properties are attributed to the reduced crystallinity and increased porosity and surface area in the composite films. In addition, the chronopotentiometric curves of the V2O5-WO3 film with a mol ratio of 10:1 are distinctively different from those of pure oxide films and other composite films with different V2O5/WO3 mol ratios, suggesting a different Li-ion intercalation process in the V2O5-WO3 film with the mol ratio of 10/1.

We have employed anodic oxidation of Ti foils to prepare self-organized TiO2 nanotube arrays which show enhanced electrochemical properties for applications as Li-ion battery electrode materials. The lengths and pore diameters of TiO2 nanotubes can be finely tuned by varying voltage, electrolyte composition, or anodization time. The as-prepared nanotubes are amorphous and can be converted into anatase nanotubes with heat treatment at 480oC and nanotubes of mixed anatase/rutile phases by heating at 580oC. The morphological features of nanotubes remain unchanged after annealing. Amorphous nanotubes with a length of 3.0 μm and an outer diameter of 125 nm delivers a capacity of 91.2 μA h cm-2 at a current density of 400 μA cm-2, while those with a length of 25 μm and an outer diameter of 158 nm display a capacity of 533 μA h cm-2. The 3-μm long anatase nanotubes and nanotubes of mixed phases show lower capacities of 53.8 μA h cm-2 and 63.1 μA h cm-2, respectively at the same current density. The amorphous TiO2 nanotubes with a length of 1.9 μm exhibit a capacity five times higher than that of TiO2 compact layer even when the nanotube array is cycled at a current density 80 times higher than that for the compact layer. The amorphous nanotubes show excellent capacity retention ability over 50 cycles. Cycled nanotubes show little change in morphology compared to the nanotubes before cycling, indicating the high structural stability of TiO2 nanotubes.

The heterogeneous photocatalytic oxidation of rhodamine B in aqueous solution containing pure or zinc (iron)-doped titania films has been studied. N-deethylation of rhodamine B was accelerated by iron(III) and zinc(II) doping as compared with pure titania film. It is shown that improvement of electron transfer from dye molecules to the film may be responsible for the high N-deethylation rate for iron-doped (0.5 mol%) film, while for zinc-doped (20 mol%) film, high surface roughness may be the main reason. In addition, both iron and zinc doping brought a new shallow trap to the intragap meaning that the surface defects had increased after doping; this is a possible reason doped films present relative low photoreactivity to catalyze the direct degradation of dye molecules.

TiO2 nanocrystals were prepared by a photo-assisted sol-gel process in which tetrabutoxide titanate was hydrolyzed in acidic medium under ultraviolet irradiation. X-ray diffraction and Raman spectra showed that the as-prepared TiO2 particles without further annealing were well-crystallized anatase. Such TiO2 particles were easily immobilized on dacron cloth and showed very high photocatalytic activity. In contrast, TiO2 particles were ill crystallized and showed lower activity when no light was introduced under otherwise equal conditions.

The redistribution of nitrogen from silicon to the Si-SiO2 interface due to thermal processing is investigated by Secondary Ion Mass Spectroscopy (SIMS) using Metal-Oxide-Semiconductor (MOS) capacitors. SIMS profiles of implanted atomic nitrogen concentration indicate a significant redistribution of the nitrogen, from the silicon to the oxide layer in response to variations of the steady state time and temperature parameters of Rapid Thermal Anneal (RTA) processing. RTA treatment, in N2 ambient, over a temperature range of 750°C - 1100°C, results in a measured increase of the integrated nitrogen peak at the interface. High Frequency Capacitance Voltage (HFCV) measurements of an implanted (N/ 5 × 1014 cm2/s / 26keV) and annealed (900°C / 10s) sample is compared with a control (without N implant) sample to determine the relative nitrogen abundance at the interface. This value corresponds to the increase in fixed oxide charge Q that produces a negative shift in the flat band voltage Vo under negative gate bias conditions.

There exists a relation (1.5) between any n + 2 distinct particular solutions of the differential equation

In this paper, we show that when and only when n = 0, 1 and 2, this relation can be represented by the following form:

provided the form of this relation function Φn depends only on n and is independent of the coefficients of the equation. This result reveals interesting properties of these non-linear differential equations.

A class of scalar periodic differential equations x ]f(x, t, A) with regularisable infinity in which the Riccati equation is included, can be treated as autonomous systems on the torus T2. Through this geometric interpretation, the properties of the set of bifurcation points of λ (∊R) are studied. When the results obtained are applied to the Riccati equation, they can match the well-known properties of the spectral set of the corresponding Hill's equation.