Melittopalynology and Trophic niche analysis of Apis cerana and Apis mellifera in Yunnan Province of Southwest China

The present study reports results of qualitative melittopalynological analyses of 34 honey samples of Apis cerana and Apis mellifera between 2011 and 2012 in Mengzi (China Yunnan) and the trophic niche analysis of two bee species on pollen food resources. A diverse spectrum of 17 pollen types from 14 families was identified with the Asteraceae and Myrtaceae being most frequent at non-nectar flow and the Lythraceae being most frequent at main nectar flow of pomegranate. The results of trophic niche analysis to Apis cerana and Apis mellifera are these, at non-nectar flow, the Niche breadth are 0.65 and 0.57, respectively; at nectar flow, the values are 0.41 and 0.24, respectively. Trophic niche overlap index, the value of nectar flow(0.68) is greater than non-nectar flow(0.61). Interspecific competition index, the value of nectar flow(0.92) is also greater than non-nectar flow(0.77). These results may promote the development of local beekeeping and help scholars assessing the impact of introduced bees on native bees in China

3-[(1H-Benzimidazol-2-yl)sulfanyl­methyl]benzonitrile

In the title compound, C15H11N3S, the dihedral angle between the benzimidazole ring system and the benzene ring is 51.8 (2)°. The crystal structure exhibits inter­molecular N—H⋯N hydrogen bonds which lead to the formation of C(4) chains along the [001] direction

On Gravitational anomaly and Hawking radiation near weakly isolated horizon

Based on the idea of the work by Wilczek and his collaborators, we consider the gravitational anomaly near weekly isolated horizon. We find that there exists a universal choice of tortoise coordinate for any weakly isolated horizon. Under this coordinate, the leading behavior of a quite arbitrary scalar field near horizon is a 2-dimensional chiral scalar field. This means we can extend the idea of Wilczek and his collaborators to more general cases and show the relation between gravitational anomaly and Hawking radiation is a universal property of black hole horizon.Comment: 14 page

Smart Hydrogel Grating Immunosensors for Highly Selective and Sensitive Detection of Human-IgG

This document is the Accepted Manuscript version of a Published Work that appeared in final form in [Industrial & Engineering Chemistry Research], copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see [https://pubs.acs.org/doi/10.1021/acs.iecr.0c00780].A smart diffraction grating immunosensor based on antigen-responsive hydrogel with enhanced analyte-induced volume changes is developed for highly selective and sensitive detection of human immunoglobulin G (H-IgG). The hydrogel grating contains poly(N-isopropylacrylamide) (PNIPAM) backbones with dual-cross-linking based on the dynamic complexation between pendent goat-anti-human IgG (GAH-IgG) and pendent H-IgG, and the covalent bonding by 4-arm-polyethylene glycol-acrylamide. Upon recognizing free H-IgG in the environment, the pendent GAH-IgG in the hydrogel can form new GAH-IgG/H-IgG complexes with free H-IgG because the binding constant of GAH-IgG to the free H-IgG is much larger than that of GAH-IgG to the pendent H-IgG and thus result in the decomplexation of GAH-IgG/H-IgG complexes with the pendent H-IgG as well as the swelling of hydrogel. The thermo-responsive PNIPAM backbones enable enhancement of H-IgG-responsive volume change of the proposed hydrogel grating via temperature regulation. Moreover, the cross-linker 4-arm-polyethylene glycol-acrylamide provides excellent transparency for the PNIPAM backbones during the volume change, which ensures output of diffracted optical signals with high intensity. With the elaborately designed molecular structures, the hydrogel grating allows highly selective and sensitive detection of [H-IgG] with a detection limit as low as 1.3 × 10–8 M. This work provides a simple and flexible strategy for developing diffraction grating immunosensors based on stimuli-responsive hydrogels for efficient detection of biomarkers

Simulation study of particle–fluid two-phase coupling flow field and its influencing factors of crystallization process

Obtaining the morphology of two-phase flow field accurately through experiments is very challenging, due to the complexity and the drainage area diversity of particle–fluid two-phase flow. Depending on the particle concentration, size, flow velocity, and so on, the two-phase flow tends to be in a more complex form, known as coupled flow status. Crystallisation process within a crystalliser is a typical engineering application of particle–fluid two-phase flow, and hence, the flow field within a potassium salt crystallizer is implemented to simulate the crystal suspension and to mix flow state during a continuous crystallisation process. Because the two-fluid model treats the particle phase and fluid phase as two distinct continuous media, this simulation model takes the effect of virtual mass force into considerations. The enhanced two-fluid model is then applied to investigate the influencing factors of the coupled flow field between the potassium salt particles and the fluid in the crystalliser under various operating conditions. The results indicated that the stirring speed, the concentration of the feed particles, and the particle size affected the distribution of coupled flow field at different levels and, thus, affected the crystallisation phenomena of a potassium salt. Among those factors, the stirring speed appears to have the most obvious effect on the flow field, as it affects the velocity of the two-phase flow. In the conditions listed in this paper, the minimum stirring speed is roughly 50 rpm to form a stable and circular flow field in the crystallizer, and the maximum particle size is controlled at around 12 mm and the feed particle concentration of roughly 32% to ensure cyclic crystallization. The research method used in this article provides a baseline for the study of the coupled flow field of particle–fluid two-phase flow and its influencing factors. This research also states theoretical guidance for the optimisation of operating conditions in the production and application of potassium salt crystallizer

Structural, magnetic and thermal properties of one-dimensional CoFe2O4 microtubes

One-dimensional CoFe2O4 microtubes have been prepared via a simple template-assembled sol–gel method. Influence of calcination temperature on structural and magnetic properties, heat capacity and specific heating rate under radiofrequency field 295 kHz was studied. A CoFe2O4 spinel was the main phase in all samples. As the calcination temperature increased, the average crystal size increased from 34.1 to 168 nm and the specific surface area decreased from 85.7 to 8.5 m2 g−1. When calcined at 1073 K, porous microtubes with a narrow size distribution in the range between 2.0 and 2.5 μm and a length to diameter ratio exceeding 20 were obtained. The heat capacity of the microtubes calcined at 973 K was 140.81 J mol−1 K−1 at 395 K, being close to the theoretic value. The sample calcined at 973 K showed highest rate of 0.293 K s−1 mg−1

Hederagenin from the leaves of ivy (Hedera helix L.) induces apoptosis in human LoVo colon cells through the mitochondrial pathway

BACKGROUND: Colorectal cancer has become one of the leading cause of cancer morbidity and mortality throughout world. Hederagenin, a derivative of oleanolic acid isolated from the leaves of ivy (Hedera helix L.), has been shown to have potential anti-tumor activity. The study was conducted to evaluate whether hederagenin could induce apoptosis of human colon cancer LoVo cells and explore the possible mechanism. METHODS: MTT assay was used for evaluating cell viability while Annexin V-FITC/PI assay and Hoechst 33342 nuclear stainining were used for the determination of apoptosis and mitochondrial membrane potential. DCFH-DA fluorescence staining and flow cytometry were used to measure ROS generation. Real-time PCR and western blot analysis were performed for apoptosis-related protein expressions. RESULTS: MTT assay showed that hederagenin could significantly inhibit the viability of LoVo cells in a concentration-dependent and time-dependent manner by IC(50) of 1.39 μM at 24 h and 1.17 μM at 48 h. The apoptosis ratio was significantly increased to 32.46% and 81.78% by the induction of hederagenin (1 and 2 μM) in Annexin V-FITC/PI assay. Hederagenin could also induce the nuclear changes characteristic of apoptosis by Hoechst 33342 nuclear stainining under fluorescence microscopy. DCFH-DA fluorescence staining and flow cytometry showed that hederagenin could increase significantly ROS generation in LoVo cells. Real-time PCR showed that hederagenin induced the up-regulation of Bax and down-regulation of Bcl-2, Bcl-xL and Survivin. Western blotting analysis showed that hederagenin decreased the expressions of apoptosis-associated proteins Bcl-2, procaspase-9, procaspase-3, and polyADP- ribosepolymerase (PARP) were increased, while the expressions of Bax, caspase-3, caspase-9 were increased. However, there was no significant change on caspase-8. CONCLUSIONS: These results indicated that the disruption of mitochondrial membrane potential might contribute to the apoptosis of hederagenin in LoVo cells. Our findings suggested that hederagenin might be a promising therapeutic candidate for human colon cancer

Controllable synthesis of one-dimensional isolated Ni 0.5 Zn 0.5 Fe 2 O 4 microtubes for application as catalyst support in RF heated reactors

One-dimensional isolated Ni0.5Zn0.5Fe2O4 microtubes have been prepared via a template assisted sol–gel method. Temperature dependence of the structural and magnetic properties was studied via XRD, N2 adsorption, SEM, TEM, and VSM. An increase in calcination temperature from 873 to 1273 K caused a decrease in the specific surface area from 80.7 to 17.0 m2/g due to an increase of the grain size from 25.3 to 112 nm. All samples demonstrated anomalous coercivity behavior due to mechanical stresses acting on their domain walls. The porous microtubes calcined at 1073 K have a mean external diameter of 3.7 μm with a length-to-diameter ratio exceeding 12. The microtubes calcined at 973 K have the highest coercivity of 88.1 Oe and demonstrated the largest specific heating rate of 4.36 W/g in a radiofrequency field at 295 kHz