Effects of rare-earth light conversion film on the growth and fruit quality of sweet pepper in a solar greenhouse.

Light is an important environmental factor influencing plant growth and development. However, artificial light supplement is difficult to spread for its high energy consumption. In recent years, rare-earth light conversion film (RPO) covering is being focused on to be a new technology to study the mechanism of light affecting plant growth and development. Compared with the polyolefin film (PO), the RPO film advanced the temperature and light environment inside the greenhouse. Ultimately, improved growth and higher yield were detected because of a higher photosynthesis, Rubisco activity and Rubisco small subunit transcription. Compared with that in the greenhouse with polyolefin film, the plant height, stem diameter and internode length of sweet pepper treated with RPO increased by 11.05, 16.96 and 25.27%, respectively. In addition, Gibberellic acid 3 (GA3), Indole-3-acetic acid (IAA), Zeatin Riboside contents were increased by 11.95, 2.84 and 16.19%, respectively, compared with that with PO film. The fruit quality was improved, and the contents of ascorbic acid (Vc), soluble protein and soluble sugar were significantly higher than those of PO film, respectively, increased by 14.29, 47.10 and 67.69%. On the basis of improved fruit quality, the yield of RPO treatment increased by 20.34% compared with PO film. This study introduces an effective and low-energy method to study the mechanism and advancing plant growth in fruit vegetables production.

A new antibacterial chromone from a marine sponge-associated fungus Aspergillus sp. LS57.

Chemical investigation for the secondary metabolite of marine-derived fungus Aspergillus sp. LS57 resulted in the isolation of one new chromone named aspergilluone A (1) containing a chromone skeleton fused with an unusual hydrogenation cyclopentanoid ring, along with three known compounds 2-4. The structure of 1 was elucidated by 1D and 2D nuclear magnetic resonance (NMR) spectroscopic and mass spectrometric analyses. Its absolute configuration was established by combining NMR quantum chemical calculations and comparison between the experimental and calculated circular dichroism (CD) curves. Additionally, the antibacterial assay of compound 1 was performed. As a result, compound 1 showed in vitro anti-Mycobacterium tuberculosis with MIC value of 32 µg/mL, together with moderate antibacterial activity against Staphylococcus aureus (MIC values = 64 µg/mL), and exhibited feeble activity against gram-positive Bacillus subtilis and gram-negative pathogen Escherichia coli (both MICs = 128 µg/mL).

New antifungal tetrahydrofuran derivatives from a marine sponge-associated fungus Aspergillus sp. LS78.

Two new tetrahydrofuran derivatives named aspericacids A and B (1 and 2) were isolated from the metabolites produced by the sponge-associated Aspergillus sp. LS78. They represented an unusual type of tetrahydrofuran derivatives, possessing 2,5-disubstituted tetrahydrofuran ring coupled with a chain unsaturated fatty acid. The planar structures of 1 and 2 were determined by HRESIMS, 1D and 2D NMR spectroscopy. The absolute configuration of 1 was assigned using both experimental and computational electronic circular dichroism (ECD). In addition, aspericacid A (1) exhibited in vitro antifungal activity (MIC = 50 µg/mL), but 2 showed not significantly activity against any of the tested strains with the MIC values of 128 µg/mL.

Size Effect on the Cytotoxicity of Layered Black Phosphorus and Underlying Mechanisms.

A systematic cytotoxicity study of layered black phosphorus (BP) is urgently needed before moving forward to its potential biomedical applications. Herein, bulk BP crystals are synthesized and exfoliated into layered BP with different lateral size and thickness. The cytotoxicity of as-exfoliated layered BP is evaluated by a label-free real-time cell analysis technique, displaying a concentration-, size-, and cell type-dependent response. The IC50 values can vary by 40 and 30 times among the BP sizes and cell types, respectively. BP-1 with the largest lateral size and thickness has the highest cytotoxicity; whereas the smallest BP-3 only shows moderate toxicity. The sensitivity of three tested cell lines follows the sequence of 293T > NIH 3T3 > HCoEpiC. Two possible mechanisms for BP to induce cytotoxicity are proposed and verified: (1) the generation of intracellular reactive oxygen species (ROS) is detected by a ROS sensitive probe using the inverted fluorescence microscopy and flow cytometry; (2) the interaction of layered BP and model cell membrane is examined by quartz crystal microbalance with dissipation, illustrating the disruption of cell membrane integrity especially by the largest BP-1. This systematic study of BP's cytotoxicity will shed light on its future biomedical and environmental applications.

Osteogenic potential and responsiveness to leptin of mesenchymal stem cells between postmenopausal women with osteoarthritis and osteoporosis.

The aim of this study was to compare the osteogenic potential and responsiveness to leptin of mesenchymal stem cells (MSCs) from bone marrow between postmenopausal women with osteoarthritis (OA) and osteoporosis (OP). MSCs of the proximal femur from OA and OP donors were cultured under control and different experimental mediums. After verifying the availability of primary cells, their osteogenic potential and responsiveness to leptin were compared between two groups. Similar patterns of cell growth were shown in both OA and OP groups. However, after the sixth passage, the viability of undifferentiated cells decreased more in OP than in OA donors. Under the same osteogenic supplements condition, the mRNA expression of osteogenesis-specific genes, osteocalcin (OC) and alkaline phosphatase (ALP) were higher in OA group. Comparison of bone matrix mineralization was parallel to that of mRNA expression. The level of bone-specific ALP (BAP) was higher in cells from donors with OA, whereas osteoprotegerin (OPG) was higher in OP group. This difference in BAP expression proved to be insignificant after the administration of leptin. Although leptin upregulated the expression of OPG, a significant difference still existed between OA and OP. In conclusion, differential osteogenic potential and responsiveness to leptin of MSCs were noted between postmenopausal women with OA and OP. Differential biological behavior of MSCs seems to be partly related to the different distribution of bone mass between OA and OP populations.