Dynamic placement of the linker histone H1 associated with nucleosome arrangement and gene transcription in early Drosophila embryonic development

The linker histone H1 is critical to maintenance of higher-order chromatin structures and to gene expression regulation. However, H1 dynamics and its functions in embryonic development remain unresolved. Here, we profiled gene expression, nucleosome positions, and H1 locations in early Drosophila embryos. The results show that H1 binding is positively correlated with the stability of beads-on-a-string nucleosome organization likely through stabilizing nucleosome positioning and maintaining nucleosome spacing. Strikingly, nucleosomes with H1 placement deviating to the left or the right relative to the dyad shift to the left or the right, respectively, during early Drosophila embryonic development. H1 occupancy on genic nucleosomes is inversely correlated with nucleosome distance to the transcription start sites. This inverse correlation reduces as gene transcription levels decrease. Additionally, H1 occupancy is lower at the 5\u27 border of genic nucleosomes than that at the 3\u27 border. This asymmetrical pattern of H1 occupancy on genic nucleosomes diminishes as gene transcription levels decrease. These findings shed new lights into how H1 placement dynamics correlates with nucleosome positioning and gene transcription during early Drosophila embryonic development

Effect of Molar Mass on Critical Specific Work of Flow for Shear-Induced Crystal Nucleation in Poly (l-Lactic Acid)

The concept of specific work of flow has been applied for the analysis of critical shearing conditions for the formation of crystal nuclei in poly (l-lactic acid) (PLLA). Systematic variation in both time and rate of shearing the melt in a parallel-plate rheometer revealed that these parameters are interconvertible regarding the shear-induced formation of crystal nuclei; that is, low shear rate can be compensated for by increasing the shear time and vice versa. This result supports the view that critical shearing conditions can be expressed by a single quantity, providing additional options for tailoring polymer processing routes when enhanced nuclei formation is desired/unwanted. Analysis of PLLA of different mass-average molar masses of 70, 90, 120, and 576 kDa confirmed improved shear-induced crystal nucleation for materials of higher molar mass, with critical specific works of flow, above which shear-induced nuclei formation occurs, of 550, 60, 25, and 5 kPa, respectively

Effect of Molar Mass on Critical Specific Work of Flow for Shear-Induced Crystal Nucleation in Poly (l-Lactic Acid)

The concept of specific work of flow has been applied for the analysis of critical shearing conditions for the formation of crystal nuclei in poly (l-lactic acid) (PLLA). Systematic variation in both time and rate of shearing the melt in a parallel-plate rheometer revealed that these parameters are interconvertible regarding the shear-induced formation of crystal nuclei; that is, low shear rate can be compensated for by increasing the shear time and vice versa. This result supports the view that critical shearing conditions can be expressed by a single quantity, providing additional options for tailoring polymer processing routes when enhanced nuclei formation is desired/unwanted. Analysis of PLLA of different mass-average molar masses of 70, 90, 120, and 576 kDa confirmed improved shear-induced crystal nucleation for materials of higher molar mass, with critical specific works of flow, above which shear-induced nuclei formation occurs, of 550, 60, 25, and 5 kPa, respectively

Overexpression of GhSWEET42, a SWEET-like gene from cotton, enhances the oil content and seed size

AbstractSWEET (‘sugars will eventually be exported transporters’) family genes reportedly play a critical role in sugar translocation and oil biosynthesis in various plant species. However, their functions in cotton are unknown. The present study demonstrated that while GhSWEET42 was widely expressed in different cotton tissues, it had the highest expression level in the developing ovules. Hence, it performs a vital role in seed development. We constructed GhSWEET42 transgenic Arabidopsis lines to verify the biological function of this gene and found that the oil content and weight of the seeds produced by the overexpression lines were 18–23% and 19–20% higher, respectively than those of the wild-type. Gas chromatography–mass spectrometry (GC–MS) analysis revealed that it was mainly a relative increase in unsaturated fatty acids (FAs) that contributed to the relative increase in oil content in the transgenic seeds. Moreover, the latter exhibited comparative upregulation of certain genes associated with FA and triacylglycerol biosynthesis as well as cell expansion. GhSWEET42 might work synergistically with the aforementioned genes. This finding indicates that GhSWEET42 may be essential in oil biosynthesis and seed development in cotton. The results of the present work may facilitate further explorations into the molecular mechanism of cottonseed oil biosynthesis as well as the cultivation of novel oil-rich cotton varieties

Improved optical limiting performance of laser-ablation-generated metal nanoparticles due to silica-microsphere-induced local field enhancement

For practical application, optical limiting materials must exhibit a fast response and a low threshold in order to be used for the protection of the human eye and electro-optical sensors against intense light. Many nanomaterials have been found to exhibit optical limiting properties. Laser ablation offers the possibility of fabricating nanoparticles from a wide range of target materials. For practical use of these materials, their optical limiting performance, including optical limiting threshold and the ability to efficiently attenuate high intensity light, needs to be improved. In this paper, we fabricate nanoparticles of different metals by laser ablation in liquid. We study the optical nonlinear properties of the laser-generated nanoparticle dispersion. Silica microspheres are used to enhance the optical limiting performance of the nanoparticle dispersion. The change in the optical nonlinear properties of the laser-generated nanoparticle dispersion caused by silica microspheres is studied. It is found that the incident laser beam is locally focused by the microspheres, leading to an increased optical nonlinearity of the nanoparticle dispersion

Efficient Biosynthesis of Phosphatidylserine in a Biphasic System through Parameter Optimization

Phosphatidylserine (PS) has significant biological and nutritional effects and finds wide applications in the food, pharmaceutical, and chemical industries. To produce high-value PS efficiently, phospholipase D (PLD)-induced transphosphatidylation of low-value phosphatidylcholine (PC) with L-serine has been explored. In this research, we purified recombinant PLD from Streptomyces antibioticus SK-3 using ion exchange chromatography and gel filtration chromatography. Subsequently, we thoroughly characterized the purified enzyme and optimized the transphosphatidylation conditions to identify the most favorable settings for synthesizing PS in a biphasic system. The purified recombinant PLD displayed a robust transphosphatidylation function, facilitating efficient catalysis in the synthesis of PS. Under the optimal conditions (butyl acetate/enzyme solution 1:1, L-serine 160 mg/mL, soybean lecithin 2 mg/mL, and MgCl2 15 mM, at 50 °C for 2.5 h with shaking), we achieved a conversion rate of 91.35% and a productivity of 0.73 g/L/h. These results demonstrate the applicability of the process optimization strategy for using the candidate enzyme in the efficient synthesis of PS. Overall, this study presents a novel and scalable approach for the efficient large-scale synthesis of PS

Synthesis and Characterization of Quadrupolar-Hydrogen-Bonded Polymeric Ionic Liquids for Potential Self-Healing Electrolytes

Within the era of battery technology, the urgent demand for improved and safer electrolytes is immanent. In this work, novel electrolytes, based on pyrrolidinium-bistrifluoromethanesulfonyl-imide polymeric ionic liquids (POILs), equipped with quadrupolar hydrogen-bonding moieties of ureido-pyrimidinone (UPy) to mediate self-healing properties were synthesized. Reversible addition–fragmentation chain-transfer (RAFT) polymerization was employed using S,S-dibenzyl trithiocarbonate as the chain transfer agent to produce precise POILs with a defined amount of UPy and POIL-moieties. Kinetic studies revealed an excellent control over molecular weight and polydispersity in all polymerizations, with a preferable incorporation of UPy monomers in the copolymerizations together with the ionic monomers. Thermogravimetric analysis proved an excellent thermal stability of the polymeric ionic liquids up to 360 °C. By combining the results from differential scanning calorimetry (DSC), broadband dielectric spectroscopy (BDS), and rheology, a decoupled conductivity of the POILs from glass transition was revealed. While the molecular weight was found to exert the main influence on ionic conductivity, the ultimate strength and the self-healing efficiency (of up to 88%) were also affected, as quantified by tensile tests for both pristine and self-healed samples, evidencing a rational design of self-healing electrolytes bearing both hydrogen bonding moieties and low-molecular-weight polymeric ionic liquids

Systematic identification and characterization of the soybean (Glycine max) B-box transcription factor family

AbstractIn plants, the B-box (BBX) transcription factors (TFs) are a subfamily of zinc-finger TFs that act to regulate diverse plant growth and development processes. The BBX TFs have been the subject of considerable attention, and are well characterized in diverse plant species, including in rice (Oryza sativa) and Arabidopsis thaliana, but less so in the economically important soybean (Glycine max). In this work, we systematically identified and characterized 57 soybean BBX genes (GmBBX1 to GmBBX57). These genes were mapped to all 20 soybean chromosomes and were divided into five clades with high intra-clade intron–exon similarity. The majority of GmBBX gene promoter cis-acting elements were responsive to light, abscisic acid, salicylic acid and methyl jasmonate, as well as a diverse array of other stimuli. Quantitative RT-PCR indicated that several GmBBX genes exhibited tissue-specific and phytohormone- and abiotic stress-responsiveness. The results of this study will be useful in the continued characterization of soybean BBX gene functions and provide new ideas for soybean breeding

Influence of extraction technology on rapeseed oil functional quality: a study on rapeseed polyphenols

Extraction technology can influence the vegetable oil functional quality. Polyphenols in rapeseed oil have been proved to be beneficial for cardiovascular health. In this study, we evaluated the effect of extraction methods on the functional quality of rapeseed oil from the perspective of phenolic compounds. The results showed that hot pressing produces the highest amount of phenolic compounds in rapeseed oil. Its most abundant phenolic compound, sinapine (9.18 μg g−1), showed the highest activity in inhibiting anaerobic choline metabolism with an EC50 value of 1.9 mM, whose downstream products are related to cardiovascular diseases. Molecular docking and molecular dynamics (MD) simulations revealed that sinapine exhibits good binding affinity toward CutC, and CutC–sinapine is a stable complex with fewer conformational fluctuations and similar tightness. Taken together, hot pressing can be considered the best extraction method for rapeseed oil from the perspective of phenolic compounds

Influence of crystallization kinetics and flow behavior on structural inhomogeneities in 3D printed parts made from semi-crystalline polymers

We report the results of a study focusing on the influence of crystallization kinetics and the flow behavior on structural inhomogeneities in 3D printed parts made from polyamide 12 (PA12) and poly (lactic acid) (PLA) by Dynamic Mechanical Analysis (DMA), Differential Scanning Calorimetry (DSC), Fast Scanning Calorimetry (FSC) and Wide-Angle X-ray Diffraction (WAXD). Temperature-dependent WAXD measurements on the neat PLA filament reveal that PLA forms a single orthorhombic α phase during slow cooling and subsequent 2nd heating. The PA12 filament shows a well pronounced polymorphism with a reversible solid-solid phase transition between the (pseudo)hexagonal γ phase near room temperature and the monoclinic α′ phase above the Brill transition temperature TB = 140 °C. The influence of the print bed temperature Tb on structure formation, polymorphic state, and the degree of crystallinity χc of the 3D printed parts is investigated by height and depth dependent WAXD scans and compared with that of 3D printed single layers, used as a reference. It is found that the heat transferred from successive layers has a strong influence on the polymorphic state of PA12 since a superimposed mixture of γ and α phase is present in the 3D printed parts. In case of PLA a single α phase is formed. The print bed temperature has, in comparison to PA12, a major influence on the degree of crystallinity χc and thus the homogeneity of the 3D printed parts, especially close to the print bed. By comparing the obtained results from WAXD, DMA, DSC and FSC measurements with relevant printing times, guidelines for 3D printed parts with a homogeneous structure are derived