The differential expression of genes is crucial for plant somatic embryogenesis (SE), and the accurate quantification of gene expression levels relies on choosing appropriate reference genes. To ...select the most suitable reference genes for SE studies, 10 commonly used reference genes were examined in synchronized somatic embryogenic and subsequent germinative cultures of Liriodendron hybrids by using quantitative real-time reverse transcription PCR. Four popular normalization algorithms: geNorm, NormFinder, Bestkeeper and Delta-Ct were used to select and validate the suitable reference genes. The results showed that elongation factor 1-gamma, histone H1 linker protein, glyceraldehyde-3-phosphate dehydrogenase and α-tubulin were suitable for SE tissues, while elongation factor 1-gamma and actin were best for the germinative organ tissues. Our work will benefit future studies of gene expression and functional analyses of SE in Liriodendron hybrids. It is also serves as a guide of reference gene selection in early embryonic gene expression analyses for other woody plant species.
Broilers in four groups were fed a basal diet supplemented with 60 mg/kg zinc oxide (60-ZnO; control), or 20, 60, or 100 mg/kg ZnO nanoparticles (20-, 60-, and 100-nano-ZnO, respectively). Compared ...with the controls, after 14 days, birds in the 20- and 60-nano-ZnO groups had significantly greater weight gains and better feed conversion ratios. However, the body weight of birds in the 100-nano-ZnO group was dramatically reduced after 28 days. Relative to the control group, the total antioxidant capability (T-AOC) in serum and liver tissue was significantly higher in the 20-nano-ZnO group at all time points and also significantly higher in the 60- and 100-nano-ZnO groups in serum on days 28 and 35 and in liver tissues on days 21 and 28. Compared with the controls, the activity of copper-zinc superoxide dismutase (Cu-Zn-SOD) was significantly greater in the 60- and 100-nano-ZnO groups in serum on days 28 and 35 and in liver tissues after 21 days. Catalase activity in serum samples was significantly higher in the 20- and 60-nano-ZnO groups relative to the control and 100-nano-ZnO birds, but catalase activity in liver tissue was not affected by different nano-ZnO levels. Malondialdehyde content in serum and liver tissues was significantly reduced in the 20-, 60-, and 100-nano-ZnO groups compared with that in the control group at all time points except day 42. Taken together, our data indicate that appropriate concentration of dietary ZnO nanoparticles improves growth performance and antioxidative capabilities in broilers, and 20 mg/kg nano-ZnO is the optimal concentration.
A new strategy for the construction of optically active 5'-CF3 spiropyrrolidin-3,2'-oxindole was described. A series of unprecedented 1,3-dipoles were obtained by condensation of CF3CH2NH2 with ...isatins. The 1,3-dipolar cycloaddition reactions of these ketimines with enals gave the products bearing four contiguous stereogenic centers in excellent yields, diastereoselectivities and enantioselectivities.
High entropy diborides require high temperature (>2000 °C) for densification, leading to grain coarsening and deteriorated mechanical properties. Herein, fully dense and fine-grained (Hf, Zr, Ta, Nb, ...Ti)B2 ceramics were successfully fabricated by spark plasma sintering at 1500 °C using metallic cobalt as additives. The result showed that the relative density of (Hf, Zr, Ta, Nb, Ti)B2 increased tremendously from 49.3% to 99.5% as 5 vol% cobalt (HEB5C-15) were introduced. The Co–B based liquid phase was reactively formed during sintering, accelerating the densification by wetting grain boundaries and resulting the presence of Co segregation. Due to the significantly reduced sintering temperature, sluggish diffusion characteristic of the high entropy matrix and the segregation drag effect, the resulting (Hf, Zr, Ta, Nb, Ti)B2 grain size was as small as 0.5 μm. Vickers hardness of HEB5C-15 densified at 1500 °C was 24.90 ± 1.39 GPa, at least 20% higher than the corresponding value in the cobalt free counterpart densified at 2000 °C.
Display omitted
There exist several positively and negatively charged electrolytes or ions in human blood, urine, and other body fluids. Tests that measure the concentration of these ions in clinics are performed ...using a more affordable, portable, and disposable potentiometric sensing method with few sample volumes, which requires the use of ion-selective electrodes (ISEs) and reference electrodes. This review summarily descriptively presents progressive developments and applications of ion selective electrodes in medical laboratory electrolytic ion tests, from conventional ISEs, solid-contact ISEs, carbon nanotube based ISEs, to graphene-based ISEs.
Carbonyl reductase (CR)-catalyzed asymmetric reduction offers an approach for producing t-butyl 6-cyano-(3R,5R)-dihydroxyhexanoate ((3R,5R)-1b), which serves as a key building block in atorvastatin ...(Liptor). However, controlling the stereopreference of CR with the desired selectivity remains challenging because natural CRs usually exhibit Prelog preference. Moreover, transferring knowledge from engineered anti-Prelog CRs to other CRs is difficult. Herein, the key residues that regulate the stereopreference of a CR from Kluyveromyces marxianus (KmCR) were identified by a semirational engineering toward t-butyl 6-cyano-(5R)-hydroxy-3-oxohexanoate ((5R)-1a). A structural switch that consists of the key residues was discovered, and related structural features were summarized to predict the stereopreference by analyzing the structural information and multiple-sequence alignment of structure-available CRs carefully. According to the obtained knowledge, the simultaneous mutation of four key residues enabled the conversion of Prelog-selectivity of KmCR into a complete anti-Prelog selectivity (de p > 99% (R) for (3R,5R)-1b). Moreover, the stereopreferences of 11 CRs that share 20–40% sequence identities with KmCR were predicted successfully and engineered experimentally. The knowledge gained from this protein engineering study on KmCR has universal significance for CRs toward (5R)-1a.
It is increasingly recognized that biotic interactions could play a significant role in species distribution modelling. To assess the conservation effectiveness of the giant panda (Ailuropoda ...melanoleuca) reserves in a changing climate, we combined both biotic variables (food availability) and abiotic (climatic and geographic) to project the potential changes of distribution and quality of giant panda habitats using the most recent IPCC-CMIP5 climate scenarios. Our results suggested that climate change would adversely affect giant pandas through habitat degradation, in that: (1) 52.9–71.3% of the current habitats could be lost; (2) the giant panda habitats could become more fragmented and isolated; and (3) both the quantity and quality of habitats in the current giant panda reserves could substantially contract, and approximately 20% of the reserves could lose all habitat representations in this century. Additionally, we found that climate change would make it increasingly necessary to translocate small populations of pandas from the southwestern to the northwestern part of the current distribution range to ensure population viability. Our results suggest the need for immediate change in current conservation policies and formulating adaptation plans for giant panda conservation in a changing climate.
As a component of China’s strategic emerging industries, green lighting is an important industry supporting the high-quality and high-efficiency development of China’s economy, and is also an ...important way to achieve energy conservation and emission reduction. At present, China has basically established a policy framework to promote the development of green lighting industry, but there is no empirical evidence on the performance of existing policies on energy conservation and emission reduction. Based on the development status of China’s green lighting industry, this paper sorts out the milestones of China’s green lighting industry policy and the current status of the framework of the existing green lighting industry development policies, constructs a policy performance evaluation model for China’s green lighting industry based on the difference-in-difference (DID) model, and evaluates the implementation effects of green lighting industry policies in China from the perspective of energy conservation and emission reduction. The empirical results of China’s 85 cities show that the implementation of green lighting industry policies has significantly promoted regional energy conservation and emission reduction. Finally, this paper puts forward targeted policy recommendations to provide policy support for the transformation of China’s green lighting industry from “large” to “strong”.
In this study, we investigated the effect of 1,3,5,8-tetrahydroxyxanthone (THX) on the adipogenesis of 3T3-L1 adipocytes. THX, a xanthone isolated from
Gentianella acuta
, inhibited lipid ...accumulation in 3T3-L1 adipocytes and reduced the protein levels of the key adipogenic transcriptional factors, peroxisome proliferator-activated receptor gamma (PPARγ) and CCAAT/enhancer-binding protein α (C/EBPα), in a dose-dependent manner. In addition, THX enhanced the transcriptional activity of Gli1 known as the key indicator of Hedgehog (Hh) signaling activity and increased the expression of Gli1 and its upstream regulator Smo. The Smo activator SAG exerted the similar effect with THX on regulating Gli1, Smo, PPARγ and C/EBPα expression, which led to the suppression of fat formation in 3T3-L1 adipocytes. Furthermore, we found that the inhibitory effect of THX on adipogenesis was derived from regulation of the early stage of adipogenesis. These results suggest that THX suppresses the differentiation of adipocyte through Hh signaling and may be considered as a potent agent for the prevention of obesity.
We report a synthetic strategy for a chemoselective switch and a diastereo‐divergent approach for the asymmetric reaction of 5H‐oxazol‐4‐ones and N‐itaconimides catalyzed by l‐tert‐leucine‐derived ...tertiary amine–urea compounds. The reaction was modulated to harness either tandem conjugate addition–protonation or 4+2 cycloaddition as major product with excellent enantio‐ and diastereoselectivities. Subjecting the enantio‐enriched cycloaddition products to a basic silica gel reagent yields the diastereomer vis‐à‐vis the product directly obtained under conditions for addition–protonation, thus opening a diastereo‐divergent route for creating 1,3‐tertiary‐hetero‐quaternary stereocenters. Quantum chemical studies further provide stereochemical analysis for the 4+2 process and a plausible mechanism for this chemoselective switch is proposed.
Divergent reaction paths: The first asymmetric reaction of 5H‐oxazol‐4‐ones with itaconimides was developed by employing a chiral tertiary amine–urea catalyst. The substrates could go through either tandem conjugate addition–protonation or 4+2 cycloaddition with excellent enantio‐ and diastereoselectivities under controlled experimental conditions.
PDF
