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SummaryNeuron-enriched microRNAs (miRNAs), miR-9/9* and miR-124 (miR-9/9*-124), direct cell fate switching of human fibroblasts to neurons when ectopically expressed by repressing anti-neurogenic genes. How these miRNAs function after the onset of the transcriptome switch to a neuronal fate remains unclear. Here, we identified direct targets of miRNAs by Argonaute (AGO) HITS-CLIP as reprogramming cells activate the neuronal program and reveal the role of miR-124 that directly promotes the expression of its target genes associated with neuronal development and function. The mode of miR-124 as a positive regulator is determined by a neuron-enriched RNA-binding protein, ELAVL3, that interacts with AGO and binds target transcripts, whereas the non-neuronal ELAVL1 counterpart fails to elevate the miRNA-target gene expression. Although existing literature indicate that miRNA-ELAVL1 interaction can result in either target gene upregulation or downregulation in a context-dependent manner, we specifically identified neuronal ELAVL3 as the driver for miRNA target gene upregulation in neurons. In primary human neurons, repressing miR-124 and ELAVL3 led to the downregulation of genes involved in neuronal function and process outgrowth, and cellular phenotypes of reduced inward currents and neurite outgrowth. Results from our study support the role of miR-124 promoting neuronal function through positive regulation of its target genes.

The effect of extrusion ratio on microstructure and mechanical properties of as-extruded Mg-6Sn-2Zn-1Ca (TZX621) (mass fraction, %) alloy was investigated. It is found that incomplete dynamic recrystallization (DRX) took place in as-extruded TZX621 alloy. As the extrusion ratio was increased from 6 to 16, both fraction of un-DRXed grains and average size of DRXed grains in as-extruded TZX621 alloy decreased and the basal texture was weakened. Coarse CaMgSn phase was broken into particles and fine Mg2Sn phase precipitated from α-Mg matrix during hot extrusion. Yield strength, ultimate tensile strength and elongation of as-extruded TZX621 alloy with extrusion ratio of 16 reached 226.9 MPa, 295.6 MPa and 18.1%, which were improved by 36.0%, 17.7% and 13.5%, respectively, compared to those of as-extruded TZX621 alloy with extrusion ratio of 6.

In this work, effects of different pre-deformation on the microstructures and corrosion behavior of 2219 aluminum alloys were investigated. The results showed that the size of grains decreased gradually and the distributions of the precipitated phases was improved effectively during the aging processes, leading to an obvious increase in tensile strength and corrosion resistance. It demonstrated that the large amount of dislocations induced by the pre-deformation processes providing the preferential conditions for the θ′ precipitated phases. The fined and dispersed θ′ phases for this alloy subjected to 20% pre-deformation effectively hindered the movement of dislocations which enhanced the tensile strength. The tensile strength decreased slightly because of the uneven distributions of θ′ phase if the pre-deformation reaches to 30%. The rank of corrosion resistance of different pre-deformation after aging process from the highest to the lowest can be drawn as: 20%＞30%＞10%＞5%, which was attributed to the change of population of θ′ precipitates and the width of precipitation free zone (PFZ).

Fine-grained AA2014 aluminum alloy was innovatively achieved by cold source assisted friction stir processing (CSA-FSP) under different cooling conditions. The investigation detailedly addresses the effects of cooling capacity induced by liquid CO2 on microstructural evolution and mechanical properties of the stirred zone (SZ) along thickness direction. The results indicated that FSP with liquid CO2 cooling can provide fine grain structures in the upper region of SZ due to higher strain rate, higher cooling efficiency, lower deformation temperature and shorter high temperature residence time. Besides the dominant CDRX and GDRX mechanisms in the entire SZ, the additional grain refinement mechanism of DDRX in the surface region while PSN in the bottom region was partially involved. The strength and microhardness of CSA-FSP 2014 aluminum alloy were enhanced as the cooling rate increased. The ultimate tensile strength in the upper region of SZ cooled with liquid CO2 achieved 519.7 MPa with a high elongation of 9.4%, which was 110.66% and 118.6% higher than that of the homogenized base alloy (246.7 MPa and 4.3%) due to the fine grain strengthening and second phase strengthening. The refined and retained second phase particles also can further enhance the grain refinement and dislocation accumulation effect, thus achieving an excellent combination of strength and plasticity. Meanwhile, the contribution of various strengthening mechanisms to the overall strength of CSA-FSP 2014 aluminum alloy was qualitatively evaluated

The changing of the microstructure and properties with the pre-deformation degree of the 2219 aluminum alloys during aging treatment was investigated. The results reveal that the pre-deformation leads to the increasing of the dislocation density in the matrix that in turn gives rise to the formation of the dense and smaller precipitated θ′ phases with dispersive distribution in the α-matrix, which results in the enhancing of the strength of the pre-deformed samples. It is also observed that the strength of the 4.19% pre-deformed sample shows an abrupt slightly decline by comparing with the 2.88% pre-deformed sample, which caused by the formation of the non-uniformly distributed θ′ precipitates due to the large amount of the dislocation cells formed by the pre-deformation in the matrix.

The initial rostrocaudal patterning of the neural tube leads to differential expression of Hox genes that contribute to the specification of motor neuron (MN) subtype identity. Although several 3′ Hox mRNAs are expressed in progenitors in a noisy manner, these Hox proteins are not expressed in the progenitors and only become detectable in postmitotic MNs. MicroRNA biogenesis impairment leads to precocious expression and propagates the noise of Hoxa5 at the protein level, resulting in an imprecise Hoxa5-Hoxc8 boundary. Here we uncover, using in silico simulation, two feed-forward Hox-miRNA loops accounting for the precocious and noisy Hoxa5 expression, as well as an ill-defined boundary phenotype in Dicer mutants. Finally, we identify mir-27 as a major regulator coordinating the temporal delay and spatial boundary of Hox protein expression. Our results provide a novel trans Hox-miRNA circuit filtering transcription noise and controlling the timing of protein expression to confer robust individual MN identity., In the spinal cord, some Hox genes are transcribed in progenitors while their proteins are only detected in differentiating postmitotic motor neurons. Here, the authors show that miRNAs (specifically mir-27) regulate post-transcriptional Hoxa5 expression in motor neurons.

The mammalian imprinted Dlk1-Dio3 locus produces multiple long non-coding RNAs (lncRNAs) from the maternally inherited allele, including Meg3 (i.e., Gtl2) in the mammalian genome. Although this locus has well-characterized functions in stem cell and tumor contexts, its role during neural development is unknown. By profiling cell types at each stage of embryonic stem cell-derived motor neurons (ESC~MNs) that recapitulate spinal cord development, we uncovered that lncRNAs expressed from the Dlk1-Dio3 locus are predominantly and gradually enriched in rostral motor neurons (MNs). Mechanistically, Meg3 and other Dlk1-Dio3 locus-derived lncRNAs facilitate Ezh2/Jarid2 interactions. Loss of these lncRNAs compromises the H3K27me3 landscape, leading to aberrant expression of progenitor and caudal Hox genes in postmitotic MNs. Our data thus illustrate that these lncRNAs in the Dlk1-Dio3 locus, particularly Meg3, play a critical role in maintaining postmitotic MN cell fate by repressing progenitor genes and they shape MN subtype identity by regulating Hox genes., eLife digest When a gene is active, its DNA sequence is ‘transcribed’ to form a molecule of RNA. Many of these RNAs act as templates for making proteins. But for some genes, the protein molecules are not their final destinations. Their RNA molecules instead help to control gene activity, which can alter the behaviour or the identity of a cell. For example, experiments performed in individual cells suggest that so-called long non-coding RNAs (or lncRNAs for short) guide how stem cells develop into different types of mature cells. However, it is not clear whether lncRNAs play the same critical role in embryos. Yen et al. used embryonic stem cells to model how motor neurons develop in the spinal cord of mouse embryos. This revealed that motor neurons produce large amounts of a specific group of lncRNAs, particularly one called Meg3. Further experiments showed that motor neurons in mouse embryos that lack Meg3 do not correctly silence a set of genes called the Hox genes, which are crucial for laying out the body plans of many different animal embryos. These neurons also incorrectly continue to express genes that are normally active in an early phase of the stem-like cells that make motor neurons. There is wide interest in how lncRNAs help to regulate embryonic development. With this new knowledge of how Meg3 regulates the activity of Hox genes in motor neurons, research could now be directed toward investigating whether lncRNAs help other tissues to develop in a similar way.

The mammalian imprintedDlk1-Dio3locus produces multiple long non-coding RNAs (lncRNAs) from the maternally inherited allele, includingMeg3(i.e.Gtl2) in the mammalian genome. Although this locus has well-characterized functions in stem cell and tumor contexts, its role during neural development is unknown. By transcriptome profiling cell types at each stage of spinal cord development, we uncovered that lncRNAs expressed from theDlk1-Dio3locus are predominantly and gradually enriched in rostral motor neurons (MNs). Mechanistically,Meg3and otherDlk1-Dio3locus-derived lncRNAs facilitate Jarid2-Ezh2 interactions. Loss of these lncRNAs compromises the H3K27me3 landscape, leading to aberrant expression of progenitor and caudalHoxgenes in postmitotic MNs. Our data illustrate that these lncRNAs in theDlk1-Dio3locus play a critical role in maintaining postmitotic MN cell fate by repressing progenitor genes and they shape MN subtype identity by regulatingHoxgenes, providing strong evidence of how lncRNAs function during embryonic development.

Automobile wheel of A356 alloy was cast by low pressure casting process. The effect of heat treatment process on microstructures and mechanical properties of A356 alloy cast was discussed. The results indicated that optimal parameters of heat treatment process for A356 alloy included solution temperature of 535°Cand holding time of 4.5hours, aging temperature of 145°Cand holding time of 4hours. Ultimate strength of A356 is 270MPa and elongation rate is 10%. Meanwhile, the microstructure has been apparently improved. The eutectic silicon particle became more spheroidal and distributed uniformly in matrix.

Long-noncoding RNAs (lncRNAs) are numerous and one of their major functions is to regulate transcription via epigenetic regulation. Epigenetic modifications have been shown to have pivotal roles in regulating motor neuron (MN) subtype specification. However, the interplay between long-noncoding RNAs (lncRNAs) and the epigenetic landscape during MN diversification remains unexplored. We systematically identified MN-enriched lncRNAs from embryonic stem cell (ESC)-derived MNs (ESC~MNs) and reveal that lncRNA Meg3 is highly expressed in MNs. Loss of Meg3 leads to ectopic expression of neural progenitor genes and caudal Hox genes. Mechanistically, Meg3 facilitates PRC2/Jarid2 interaction and targets them to non-neuronal genes to maintain postmitotic MN fate, while sculpting MN subtype identity by targeting caudal Hox genes. Absence of lncRNAs (including Meg3) from the Dlk1-Dio3 imprinted locus in embryos leads to ectopic Hoxc8 expression in the Hoxa5 domain and eroded axonal arborization in the proximal nerves of brachial spinal segments. We suggest that Meg3 is a critical lncRNA for choreographing MN cell fate and subtype identity.

Microstructural evolution of AZ61 magnesium alloy was analyzed after ECAE process. This research focused on the effects of deformation temperature and extrusion passes on microstructure of AZ61 magnesium alloy. The results showed that microstructure have not improved significantly at the lower temperature. Grains can be refined greatly at deformation temperature of 370°C. With an increase of extrusion passes, grains tend to be much refined, which is beneficial to obtaining good property.

The paper briefly analyzes and systematically summarizes flotation process and chemical treatment method of low-grade oxidized copper ores in recent years. The new high-efficient collectors and system of reagent combined usage are developed widely and have become an important research direction of oxidized copper ores.

The flotation methods of scheelite, such as conventional flotation, heating flotation, lime flotation and their application were reviewed in this paper.

This paper reviews all possible traditional methods to digest natural polysaccharides, which have been widely used as depressants or flocculants in flotation. Its characteristics of environmental friendly, highly selectivity and availability helps a lot in its application either in food or mining industries. The common digestion methods in flotation of polysaccharides, such as starch or dextrin, include thermal treatment at different temperatures or alkali-digestion at different concentrations.

Hot compression of AZ3l magnesium alloy was carried out at deformation temperatures of 523-723K and strain rates of 0.01-10s-1. The effects of deformation process on the microstructure and flow stress were investigated. The flow stress curves showed the characteristic of dynamic recrystallization (DRX) with deformation process parameters. Optical microscopy and TEM observations indicated that dynamic recrystallisation and twins structure were found during hot compression. Deformation mechanism of AZ3l magnesium alloy at elevated temperature was discussed in this paper.

Hot compression test for AZ3l magnesium alloy at deformation temperatures of 523-723K and strain rates of 0.01-10s-1 were carried out using Gleeble-3500 thermo-mechanical simulator. The experimental results show that the flow stress and microstructure vary apparently with deformation process parameters. Microstructure observations show that dynamic recrystallisation (DRX) takes place during the deformation. The characteristic with the dynamic recrystallization change with the process parameters.

The X-linked disease Barth syndrome (BTHS) is caused by mutations in TAZ; TAZ is the main determinant of the final acyl chain composition of the mitochondrial-specific phospholipid, cardiolipin. To date, a detailed characterization of endogenous TAZ has only been performed in yeast. Further, why a given BTHS-associated missense mutation impairs TAZ function has only been determined in a yeast model of this human disease. Presently, the detailed characterization of yeast tafazzin harboring individual BTHS mutations at evolutionarily conserved residues has identified seven distinct loss-of-function mechanisms caused by patient-associated missense alleles. However, whether the biochemical consequences associated with individual mutations also occur in the context of human TAZ in a validated mammalian model has not been demonstrated. Here, utilizing newly established monoclonal antibodies capable of detecting endogenous TAZ, we demonstrate that mammalian TAZ, like its yeast counterpart, is localized to the mitochondrion where it adopts an extremely protease-resistant fold, associates non-integrally with intermembrane space-facing membranes and assembles in a range of complexes. Even though multiple isoforms are expressed at the mRNA level, only a single polypeptide that co-migrates with the human isoform lacking exon 5 is expressed in human skin fibroblasts, HEK293 cells, and murine heart and liver mitochondria. Finally, using a new genome-edited mammalian BTHS cell culture model, we demonstrate that the loss-of-function mechanisms for two BTHS alleles that represent two of the seven functional classes of BTHS mutation as originally defined in yeast, are the same when modeled in human TAZ.

A novel cationic waterborne epoxy emulsion for oil filter paper was synthesized. Hydrophilic groups were introduced into a multifunctional bisphenol-A novolac epoxy resin (NEP) by chemical modification, while maintaining the epoxy groups as many as possible, which were neutralized to form the equably water dispersed epoxy resin. The structure of modified NEP in different rate of ring-opening was characterized by Fourier Transform Infrared Spectroscopy (FTIR). The emulsion particle dispersion and micromorphology of waterborne bisphenol-A novolac epoxy resin (WNEP) was detected by granularity measured instrument and TEM. Mechanical properties and microstructure of oil filter papers impregnated by five different waterborne epoxy emulsions were tested and observed by SEM. From the results it can be shown that oil filter paper impregnated by WNEP emulsion has comprehensive properties better than other four commercialized products, exhibiting the best air permeability and improved bursting strength15% higher than that impregnated by poly-styrene-acrylate (PSA) latex.

Summary The ability to convert human somatic cells efficiently to neurons facilitates the utility of patient-derived neurons for studying neurological disorders. As such, ectopic expression of neuronal microRNAs (miRNAs), miR-9/9∗ and miR-124 (miR-9/9∗-124) in adult human fibroblasts has been found to evoke extensive reconfigurations of the chromatin and direct the fate conversion to neurons. However, how miR-9/9∗-124 break the cell fate barrier to activate the neuronal program remains to be defined. Here, we identified an anti-neurogenic function of EZH2 in fibroblasts that acts outside its role as a subunit of Polycomb Repressive Complex 2 to directly methylate and stabilize REST, a transcriptional repressor of neuronal genes. During neuronal conversion, miR-9/9∗-124 induced the repression of the EZH2-REST axis by downregulating USP14, accounting for the opening of chromatin regions harboring REST binding sites. Our findings underscore the interplay between miRNAs and protein stability cascade underlying the activation of neuronal program.

The conformations of phenylazo-2-naphthalene (I) and phenylazo-1-naphthalene (II) have been studied using ab initio methods and density functional theory. The rotational potential energy surfaces about the CN bonds were calculated for both the trans and the cis forms at the PM3 and HF/STO-3G levels. The PM3 method was found to be incapable for locating the energy minima correctly. The geometries of rotamers obtained from the HF/STO-3G surface were fully optimized at the HF/6-31G* and B3LYP/6-31G* levels. Single-point MP2/6-31G* calculations have also been carried out at the HF/6-31G* geometries. The vibrational spectra, standard thermodynamic functions, heats of formation, and equilibrium molar fractions have been obtained. According to the calculated results, I is comparatively more stable than II. The trans forms have much lower energies than the cis forms, implying that I and II mainly exist in the trans planar forms. The energy gap (ΔE) between the frontier molecular orbitals (MOs) of the cis forms are about 0.7 eV higher than those of the trans ones, indicating that change in geometry from trans to cis form will cause a hypsochromic effect. © 2000 John Wiley & Sons, Inc. Int J Quant Chem 79: 25–33, 2000

crystal – was grown in our Laboratory. The absorption and fluorescence spectra were measured and show some differences from the results of common Nd:MgO:LiNbO3 with monodomain structure. Third-order quasi-phase-matched violet second-harmonic generation in the sample was demonstrated to characterize the quality of the crystal. The properties indicate that the periodically poled optical superlattice Nd:MgO:LiNbO3 has great potential for constructing a blue or green light source through self-frequency-doubling operation using the maximum nonlinear optical coefficient d33 of LiNbO3 and the high-gain π polarization at the same time.

Optical superlattice crystals were grown by the Czochralski method. The effect of thermal annealing below the Curie temperature on domain structures of a sample with good periodicity was studied. It was found that the periodic domain structure remained unchanged at annealing temperature lower that and began to deteriorate when annealed at above . A sample at for an hour almost changed to a single-domain structure except that a single-domain layer with reversed spontaneous polarization was formed at the edge of the sample. These results are useful for revealing the mechanism of formation of the periodic domain structure and designing a more favourable temperature field to improve the crystals' quality. A space-charge-field model was proposed to explain the phenomena.

Fluorescence spectra of phosphate glasses with different erbium doping have been measured. The flourescence intensity reaches its maximum at an Er3+-doping concentration of 0.75 mol%. When the Er3+ doping exceeds 0.75 mol%, the fluorescence intensity decreases due to concentration quenching. The attenuation at 1.53 µm of the fiber is 12.8 db/m. The fluorescence up-conversion of 1.064 µm Nd:YAG laser pulses into intense green 547 and 667 nm light in the fiber has been measured. The fluorescence output power of green (547 nm) and red (667 nm) light is 178 and 42 μW, respectively with an excitation power of 1 W. The two signals are referred to as4S3/2 →4I1 5/2 and4F9/2 →4I1 5/2 transitions through two-photon absorption fluorescence.

Some thermomechanical properties such as expansion, transition temperature and high-temperature viscosity of phosphate glasses with different P2O5 and BaO compositions have been measured. Absorption and fluorescence spectra of the phosphate glasses with different Er3+ doping have also been measured. The Er3+ doping concentration with respect to the maximal fluorescence intensity is 0.75 mol %. The attenuation of the fibre at a wavelength of 1.53 μm is 12.8 db m−1. Upconversion of 1.064 μm Nd∶YAG laser pulses into intense green 547 and 667 nm light in the 0.75 mol % Er3+-doped phosphate glass fibre has been achieved. The output power of the two fluorescence signals of green 547 nm and red 667 nm are 178 and 42 μW, respectively, with an upconversion efficiency of 1.78×10−2% and 4.2×10−3% respectively.

Absorption spectra and fluorescence spectra in Er 3+ -doped phosphate glasses have been measured. Some emission parameters, such as emission cross section, spontaneous emission probability, and fluorescence linewidth of the Er 3+ -doped phosphate glass, have been calculated. Upconversion of 1.064 μm Nd:YAG laser pulses into intense green 547 nm and red 667 nm light in a Er 3+ -doped phosphate glass fiber has been achieved. Fluorescence efficiencies of the two signals, green 547 nm and red 667 nm fluorescences, are 1.78 × 10 −2 % and 4.2 × 10 −3 %, respectively. The two signals are refered to 4 S 3 2 → 4 I 15 2 and 4 F 9 2 → 4 I 15 2 radiative transitions by two-photon absorption fluorescence.

According to fundus fluorescein angiography images characteristics, this paper proposes a feature based image mosaic vessel edge method. First, detect edge of blood vessels by carrying on the pretreatment to the fundus fluorescein angiography image in the foundation, wavelet edge detection algorithm. Then, the matching method based on chain code feature is described. Finally, a local area based on gray level information of the image fusion method is applied to angiographic image series. Data processing results show that the method can generate an ideal mosaic effect.

Frequency tuning of optical parametric generators in periodically poled LiNbO3 by applying a periodic electric field was demonstrated. Remarkable wavelength change was achieved. The dependence of the wavelength shift on the applied field shows a linear relationship. The tuning rates exceeding 3 nm/(kV/mm) were obtained. The phenomenon of dispersion in electro-optic tuning was predicted. Possible applications were discussed.

Optical superlattice Er:LiNbO3 was fabricated by inducing a periodic ferroelectric domain structure into the crystal during the growing process. Because of the combination of the nonlinear optical properties of LiNbO3 and the spectral properties of Er3+, the crystal can simultaneously emit the second harmonic light through quasi-phase matching and the green light through upconversion at room temperature. Pumped by infrared diode lasers, violet-and-green and blue-and-green light generation was demonstrated in two samples. The detailed absorption spectrum and emission spectrum of upconversion were measured. The possible physical mechanism was discussed.

It is shown that, when two coherent waves are obliquely incident to a one-dimensional nonlinear optical superlattice containing Kerr-form dielectric nonlinearity, an incident-dependent two-dimensional nonlinear optical superlattice can be constructed. This structure can be bistable. There exist two types of optical bistable mechanism, i.e., the index-modulation mechanism and distributed feedback mechanism. Owing to the index-modulation mechanism, the threshold for the bistability is lower than that of a more traditional one-dimensional distributed feedback structure.

We report the 390 and 385 nm violet light generation by frequency doubling of a tunable 90 fs, 82 MHz Ti:sapphire laser in two optical superlattice LiNbO3 samples through third‐order quasiphase matching (QPM). With the average incident infrared light power of 770 mW, 9.7 and 2.9 mW output second‐harmonic lights were obtained without photorefractive damage. The QPM wavelength acceptance bandwidth measurement indicates that violet light generation with higher efficiency is possible.

A transmission silica phase mask grating was used to fabricate LiNbO3 wafer phase gratings by a single excimer pulse at 248 nm. The morphologies of the LiNbO3 wafer gratings were studied with an atomic force microscope as well as an optical microscope. The crystal structures of the gratings were characterized by x‐ray diffraction and three new crystal phases were found at the gratings’ surface besides the substrate phase of LN (110).

Optical superlattice LiNbO3 crystals with a modulation period number over 200 and a modulation period from 2.0 to over 15.0 μm were grown by the Czochralski method in a carefully designed asymmetric temperature field system. Measurements of the frequency doubling efficiency for generating light from blue to green were performed. The largest efficiency obtained was 24.0% for frequency doubling of a picosecond 980 nm fundamental light. The angle tuning tolerance of a LiNbO3 optical superlattice was measured to be over 10° of the incidence angle.

We have grown Nd:MgO:LiNbO3 crystals with periodic ferroelectric domain structures. Absorption and fluorescence spectra measured on these crystals showed little difference from those from Nd:MgO:LibO3 with uniform domain structures. Green fluorescence was generated by self‐frequency doubling in a cavity having great losses and pumped by a pulsed dye laser.