Morphology and Properties of Mg2Si Phase Modified by Pb in As-Cast Mg-2.5Si-xPb Alloys.

Pb plays an important role in determining the morphologies and mechanical properties of the Mg2Si phase in Mg-2.5Si-xPb alloys. As the amount of Pb increases from 0.4 wt.% to 1 wt.%, the primary Mg2Si phase is refined during solidification. Its morphologies transform from equiaxed-dendrite to polygonal and finally to roughly circular. The key reason for morphology evolution is the preferential adsorption of Pb atoms on Mg2Si {100} surfaces to suppress the growth rate along the ⟨100⟩ directions, which is demonstrated by the adsorption model based on first principles. In addition, the hardness of the Mg2Si phase decreases with the increasing solution content of Pb according to the results of the nanoindentation. With the addition of Pb at 1 wt.%, Pb content in the primary Mg2Si phase reaches a maximum of 0.4 wt.%, and the hardness of the primary Mg2Si phase reaches a minimum of 3.64 GPa. This reduction in hardness is attributed to the augmented ionic bond ratio resulting from the solution of Pb, which concurrently enhances the toughness of the Mg2Si phase.

Development and Validation of a Prediction Model for 30-Day Mortality and Functional Outcome in Patients with Primary Brainstem Hemorrhage.

INTRODUCTION: Primary brainstem hemorrhage (PBSH) is the most fatal subtype of intracerebral hemorrhage and is associated with poor prognosis. We aimed to develop a prediction model for predicting 30-day mortality and functional outcome in patients with PBSH. METHODS: We reviewed records of 642 consecutive patients with first-time PBSH from three hospitals between 2016 and 2021. Multivariate logistic regression was used to establish a nomogram in a training cohort. Cutoff points of the variables were determined by receiver operating characteristic curve analysis, and certain points were assigned to these predictors to produce the PBSH score. The nomogram and PBSH score were compared with other scoring systems for PBSH. RESULTS: Five independent predictors, comprised of temperature, pupillary light reflex, platelet-to-lymphocyte ratio, Glasgow Coma Scale (GCS) score on admission, and hematoma volume, were incorporated to construct the nomogram. The PBSH score consisted of 4 independent factors with individual points assigned as follows: temperature, ≥38°C (=1 point), <38°C (=0 points); pupillary light reflex, absence (=1 point), presence (=0 points); GCS score 3-4 (=2 points), 5-11 (=1 point), and 12-15 (=0 points); PBSH volume >10 mL (=2 points), 5-10 mL (=1 point), and <5 mL (=0 points). Results showed that the nomogram was discriminative in predicting both 30-day mortality (area under the ROC curve [AUC] of 0.924 in the training cohort, and 0.931 in the validation cohort) and 30-day functional outcome (AUC of 0.887). The PBSH score was discriminative in predicting both 30-day mortality (AUC of 0.923 in the training cohort and 0.923 in the validation cohort) and 30-day functional outcome (AUC of 0.887). The prediction performances of the nomogram and the PBSH score were superior to the intracranial hemorrhage (ICH) score, primary pontine hemorrhage (PPH) score, and new PPH score. CONCLUSIONS: We developed and validated two prediction models for 30-day mortality and functional outcome in patients with PBSH. The nomogram and PBSH score could predict 30-day mortality and functional outcome in PBSH patients.

N/S Co-Doped Graphene Aerogels as Superior Anode Materials for High-Rate Lithium-Ion Batteries.

The nitrogen and sulfur co-doped graphene aerogel (SNGA) was synthesized by a one-pot hydrothermal route using graphene oxide as the starting material and thiourea as the S and N source. The obtained SNGA with a three-dimensionally hierarchical structure, providing more available pathways for the transport of lithium ions. The existing form of S and N was regulated by changing the calcination temperature and thiourea doping amount. The results revealed that high temperature could decompose -SOX- functional groups and promote the transformation of C-S-C to C-S, ensuring the cyclic stability of electrode materials, and increasing the thiourea dosage amount introduced more pyridine nitrogen, improving the multiplicative performance of electrode materials. Benefiting from the synergistic effect of sulfur and nitrogen atoms, the prepared SNGA showed superior rate capability (107.8 mAh g-1 at 5 A g-1), twice more than that of GA (52.8 mAh g-1), and excellent stability (232.1 mAh g-1 at 1 A g-1 after 300 cycles), 1.85 times more than that of GA (125.6 mAh g-1). The present study provides a detailed report on thiourea as a dopant to provide a sufficient basis for SNGA and a theoretical guide for further modifying.

Antibacterial and anti-inflammatory effects of PGLa-loaded TiO2 nanotube arrays.

Objectives: This study investigated the antimicrobial effect and anti-inflammatory activities of PGLa-loaded TiO2 nanotube arrays (TiO2 NTs) in osteoblast-like MG-63 cells. Methods: The surface morphology and roughness of three titanium (Ti) substrates (Ti, TiO2 NTs, PGLa-loaded TiO2 NTs) were evaluated by scanning electron microscopy (SEM) and atomic force microscope (AFM). The wettability of three titanium substrates was evaluated by contact angle. Biocompatibility of PGLa-loaded TiO2 NTs were evaluated in MG-63 cells (cell adhesion, proliferation, cytoskeletal evaluation and alkaline phosphatase activity). Spread plate counting method was used to evaluate antibacterial abilities of the titanium substrates. The calcein AM/PI staining evaluated cell viability of MG-63 cells on the substrates with or without proinflammatory factors (TNF-α). Results: The average surface roughness of untreated Ti, TiO2 NTs, PGLa-loaded TiO2 NTs were found to be 135.8 ± 6.4 nm, 300.5 ± 10.5 nm, 348.9 ± 16.9 nm, respectively. The contact angle of the untreated Ti was 77.4° ± 6.6°. TiO2 NTs displayed excellent wettability which of contact angle was 12.1° ± 2.9°. The contact angle of the PGLa-loaded TiO2 NTs was 34.6° ± 4.9°. MG-63 cells on surface of PGLa-loaded TiO2 NTs showed better cell adhesion, proliferation and osteogenic activity. The antibacterial rate of PGLa-loaded TiO2 NTs group significantly increased (84.6% ± 5.5%, p < 0.05). The rate of dead cells on the surfaces of the PGLa-loaded TiO2 NTs with TNF-α decreased significantly (4.49% ± 0.02, p < 0.01). Conclusion: PGLa-loaded TiO2 NTs have multi-biofunctions including biocompatibility, antibacterial and anti-inflammatory properties.

MicroRNA-215-5p promotes proliferation, invasion, and inhibits apoptosis in liposarcoma cells by targeting MDM2.

BACKGROUND: Liposarcoma (LPS) is one of the most common soft tissue malignancies in adults, and it is characterized by dysregulation of multiple signaling pathways, including MDM2 proto-oncogene (MDM2) amplification. MicroRNA (miRNA) regulates gene expression through incomplete complementary pairing with the 3' untranslated region of mRNAs involved in tumor progression. METHODS: In this study, bioinformatics analysis, RT-qPCR, dual-luciferase reporter gene, MTT, flow cytometry, cell scratches, chamber migration, colony formation, FISH, WB, and CCK8 were used. RESULTS: RT-qPCR showed that the expression of MDM2 was increased when miR-215-5p was overexpressed compared with the control group. The dual-luciferase reporter gene showed that the Renilla ratio firefly fluorescence intensity was decreased in the overexpression group compared with the control group. Cell phenotype experiments revealed that the overexpression group had increased cell proliferation rate, increased apoptosis rate, increased colony formation rate, increased cell healing area ratio, and increased number of cell invasions. FISH revealed increased MDM2 expression in the overexpression group. WB suggested decreased Bax expression, increased PCNA, Bcl-2, and MDM2 expression, and decreased P53 and P21 expression in the overexpression group. CONCLUSIONS: In this study, we suggest that miR-215-5p can target and promote MDM2 expression, promote the proliferation and invasion of LPS cells SW-872, and inhibit apoptosis.Targeting miR-215-5p may be a novel therapeutic strategy for the treatment of LPS.

Mechanisms of changing speciation and bioavailability of selenium in agricultural mollisols of northern cold regions.

The distribution, speciation, and bioavailability of selenium (Se) - an essential micronutrient for human beings - in agricultural soils influence the resource recovery of agricultural benefits and the sustainable use of Se in agroecosystems. Quantitative understanding in this regard however remains limited in the world's mollisol agroecosystems, despite their critical importance in securing global food supply. Herein, a systematic investigation of Se in the river sediment-irrigation water-mollisols-rhizosphere-rice seeds continuum, at the core zone of the northern mollisol regions, was conducted to elucidate the hydrological-hydrogeochemical processes and mechanisms responsible for the distribution and bioavailability of Se. The content of total Se in the mollisols ranged between 0.12 and 0.54 mg/kg with an average of 0.31 mg/kg. At the riverside flood plains, humic-acid bound Se accounted on average for 39 % of total Se. This pool of Se can be transformed to water-soluble and ion-exchangeable Se(VI), supporting a higher potential of Se bioavailability at riparian agricultural mollisols. For mollisol lands far from the river channels, the topography affects the speciation and partitioning of Se presumably through regulating water retention and organic matter transport. Moreover, altering pH and redox conditions in response to irrigation with the river water may boost Se bioavailability in weakly acidic and high Eh mollisols. It can be in part ascribed to the transformation of organic-bound Se along with infiltrated oxygenated water that leads to the increase of water-soluble and ion-exchangeable Se. These findings reinforce that hydrological-hydrogeochemical perturbations due to irrigation with surface water need to be assessed carefully in the management of Se resources in the mollisol agroecosystems.

Unveiling the effects of atomic electronegativity on ESIPT behaviors for FQ-OH system: A theoretical study.

In this work, we mainly focus on exploring the effects of atomic electronegativity on excited state intramolecular proton transfer (ESIPT) behavior for novel FQ-OH derivatives theoretically. Combining analyses of geometrical changes, infrared (IR) spectral variations, and bonding energies via band critical point (BCP) parameters, we clarify the excited state hydrogen bonding strength is enhancing with decrease of atomic electronegativity. In addition, photo-induced charge reorganization and different energy gap of momentous frontier molecular orbitals (MOs) further reflect intramolecular charge transfer (ICT) promotes ESIPT reaction. Low atomic electronegativity reveals excited state high kinetic dynamics and chemical activities. Via constructing potential energy curves (PECs) and searching transition state (TS), we clarify atomic electronegativity dependent ESIPT behavior for FQ-OH. Particularly, the modification of atomic electronegativity also plays critical roles in regulating UV-Vis spectra. This work not only uncovering detailed ESIPT mechanism for FQ-OH, but also presents a novel regulated mechanism via atomic electronegativity.

METTL3 stabilizes HDAC5 mRNA in an m6A-dependent manner to facilitate malignant proliferation of osteosarcoma cells.

Osteosarcoma (OS) is a prevalent primary bone sarcoma. Methyltransferase-like 3 (METTL3) is dysregulated in human malignancies. This study explored the mechanism of METTL3 in OS cell proliferation. Our results demonstrated that METTL3 was highly expressed in OS, and correlated with the tumor size, clinical stage, and distant metastasis of OS patients. Higher METTL3 expression indicated poorer prognosis. METTL3 silencing inhibited the malignant proliferation of OS cells, while METTL3 overexpression led to an opposite trend. METTL3 upregulated histone deacetylase 5 (HDAC5) expression in OS cells by increasing the m6A level. HDAC5 reduced the enrichment of H3K9/K14ac on miR-142 promoter, thus suppressing miR-142-5p expression and upregulating armadillo-repeat-containing 8 (ARMC8) level. HDAC5 overexpression or miR-142-5p silencing attenuated the inhibitory effect of METTL3 silencing on OS cell proliferation. Xenograft tumor experiment in nude mice confirmed that METTL3 silencing repressed OS cell proliferation in vivo via the HDAC5/miR-142-5p/ARMC8 axis. Collectively, METTL3-mediated m6A modification facilitated OS cell proliferation via the HDAC5/miR-142-5p/ARMC8 axis.

A theoretical study of the intermolecular interactions of H2-CuF complex: Intermolecular vibrations, isotope effects, and rotational structure.

In this paper, a theoretical study has been made on the intermolecular interactions of the H2-CuF complex, including binding energy, intermolecular vibrations, isotope effects, and rotational structure. Based on different bond lengths of H2 and CuF monomers, three intermolecular potential energy surfaces (PESs) were constructed at the level of single and double excitation coupled-cluster method with a non-iterative perturbation treatment of triple excitations [CCSD(T)] with aug-cc-pVTZ basis set supplemented with bond functions. A global minimum on the PESs show that H2-CuF complex belongs to C2ν point group with a T-shaped structure. The obtained binding energy ranges from 8890 to 10050 cm-1, which increases as the increment of H-H bond length, but opposite case has been determined as the increment of Cu-F bond length. The accuracy of PESs was examined by the available data of 101-000 transition. The predicted rotational transition frequency obtained from bound state calculations can reproduce the experimental observation very well, and the predicted error is 0.1% based on the PES1 constructed with rH2 and rCuF fixed at 0.838 and 1.7409 Å. By analyzing the wave function of the bound state, the intermolecular vibrational modes were assigned unambiguously. Isotope effects were also studied and the largest error is also 0.1% compared with the available 101-000 transition data. A set of spectroscopic parameters were obtained for six isotopologues to determine rotational structure of H2-CuF complex. Upon the complex formation, the obtained structure parameters show that H-H bond length is elongated by 0.081 Å, while Cu-F value is shortened by 0.008 Å from the respective average bond lengths of free monomer.

The Zea mays mutants opaque2 and opaque16 disclose lysine change in waxy maize as revealed by RNA-Seq.

In maize, opaque2 (o2) and opaque16 (o16) alleles can increase lysine content, while the waxy (wx) gene can enhance the amylopectin content of grains. In our study, o2 and o16 alleles were backcrossed into waxy maize line (wxwx). The o2o2o16o16wxwx lines had amylopectin contents similar to those of waxy line. Their nutritional value was better than waxy line, but the mechanism by which the o2 and o16 alleles increased the lysine content of waxy maize remained unclear. The o2o2o16o16wxwx lines and their parents on kernels (18th day after pollination) were subjected to RNA sequencing (RNA-Seq). The RNA-Seq analysis revealed 272 differentially expressed genes (DEGs). Functional analyses revealed that these DEGs were mainly related to biomass metabolism. Among them, in o2o2o16o16wxwx lines, 15 genes encoding α-zein were down-regulated, which resulted in the reduction of α-zein synthesis and increased lysine content; lkr/sdh1 and Zm00001d020984.1 genes involved in the lysine degradation pathway were down-regulated, thereby inhibited lysine degradation; sh2, bt2 and ae1 genes involved in starch metabolism were upregulated, leaded to wrinkling kernel and farinaceous endosperm. Our transcriptional-level identification of key genes responsible for increased grain lysine content and farinaceous endosperm formation following introgression of o2 and o16 alleles should promote molecular breeding for maize quality.

Transcriptome Dynamics of Double Recessive Mutant, o2o2o16o16, Reveals the Transcriptional Mechanisms in the Increase of Its Lysine and Tryptophan Content in Maize.

In maize, pyramiding of o2 and o16 alleles can greatly improve the nutritional quality of grains. To dissect its molecular mechanism, we created a double recessive mutant line, o2o2o16o16, by introgression of the o2 and o16 alleles into the wild-type maize inbred line, by molecular marker-assisted backcross selection. The kernels (18 day after pollination (DAP), 28 DAP, and 38 DAP) of the o2o2o16o16 mutant and its parent lines were subject to RNA sequencing (RNA-Seq). The RNA-Seq analysis revealed that 59 differentially expressed genes (DEGs) were involved in lysine metabolism and 43 DEGs were involved in tryptophan metabolism. Among them, the genes encoding AK, ASADH, and Dap-F in the lysine synthesis pathway were upregulated at different stages of endosperm development, promoting the synthesis of lysine. Meanwhile, the genes encoding LKR/SDH and L-PO in the lysine degradation pathway were downregulated, inhibiting the degradation of lysine. Moreover, the genes encoding TAA and YUC in the tryptophan metabolic pathway were downregulated, restraining the degradation of tryptophan. Thus, pyramiding o2 and o16 alleles could increase the lysine and tryptophan content in maize. These above results would help to uncover the molecular mechanisms involved in the increase in lysine and the tryptophan content, through the introgression of o2 and o16 alleles into the wild-type maize.

Molecular Mechanisms Underlying Increase in Lysine Content of Waxy Maize through the Introgression of the opaque2 Allele.

The opaque2 (o2) mutation in maize is associated with high lysine content in endosperm and good nutritional value. To improve the nutritional quality of waxy maize, the o2 allele was introgressed into the wxwx line using marker-assisted backcrossing selection technology. The lysine content of o2o2wxwx lines was higher than that of the wxwx line. To reveal the mechanism of increasing lysine content through introgression of the o2 in waxy maize, the transcriptome on kernels (18th day after pollination) of the o2o2wxwx and parent lines was analyzed using RNA-sequencing (RNA-Seq). The RNA-Seq analysis revealed 49 differentially expressed genes (DEGs). Functional analysis showed that these DEGs were mostly related to the catalytic activity and metabolic processes. The O2 gene regulated multiple metabolic pathways related to biological processes (BP) and molecular function (MP) during waxy maize endosperm development. In particular, in the o2o2wxwx lines, the two genes that encode the EF-1α and LHT1 were up-regulated, but the gene that encodes sulfur-rich proteins was down-regulated, raising the grain lysine content. These findings are of great importance for understanding the molecular mechanism underlying the lysine content increase due to o2 allele introgression into waxy maize.

Nanoporous Au-Ag shell with fast kinetics: integrating chemical and plasmonic catalysis.

Nanoporous noble metals and alloys are widely utilized as efficient catalysts, because they have high surface-to-volume ratios for sufficient active sites and induce molecule polarization through plasmon excitation as well. Herein, we demonstrate one approach to fabricate nanoporous Au-Ag shell. Such material represents the dual functions serving as efficient catalysts and high-performance surface-enhanced Raman scattering substrate. In situ spectrum acquisition can track the conversion of p-nitrothiophenol to 4, 4'-dimercapto-azobenzene at ambient temperature. In particular, as a result of chemical catalysis of Ag elements and strong plasmon-molecule coupling, catalytic kinetics of nanoporous Au-Ag shell is 79.2-123.8 times faster than Au nanoparticles (NPs), and 2.2-3.3 times faster than Ag NPs. This investigation offers a route to design superior catalysts to integrate chemical and plasmonic catalysis.

Screening lactic acid bacteria with high yielding-acid capacity from pickled tea for their potential uses of inoculating to ferment tea products.

For there were very short of excellent strains inoculated to ferment tea products, the lactic acid bacteria from pickled tea were isolated, characterized and identified, and the acid production capacity of part better strains was determined. There are only 22 strains isolated from pickled tea, and 2 of them were yeast, and 8 strains selected from the other 20 strains all were identified as Lactobacillus plantarum. A1, L2 and L5 of L. plantarum with a high acid production capacity were screened out and could obviously shorten the fermentation time of pickled tea by the verification, which suggests that they have a potential use of inoculating to ferment tea products. It was the first report on screening lactic acid bacteria with high yielding-acid capacity from pickled tea, which will bring benefits to fermenting tea products by artificial inoculation.

Conformations of 2-thiouracil in the aqueous solution and its adsorption behavior on the gold substrates explored by DFT calculations and experimental methods.

2-Thiouracil, a thio-derivative of uracil, may appear in various tautomeric forms due to the different positions of protons. In this paper, the adsorption behavior and conformations of 2-thiouracil on the gold substrates are inspected by means of surface-enhanced Raman scattering (SERS) and density functional theory (DFT) calculations. The results indicate that all the enhanced bands are assigned to in-plane vibration modes. Besides, most of the bands related to N and S atoms are significantly enhanced and have obvious shifts in the SERS spectra. Furthermore, the CO stretching band at 1695 cm(-1) also appears in the SERS spectra. The theoretical SERS spectra of 2TU-Au4 and 2TU2-Au4 complexes agree well with the experimental SERS spectra of 2-thiouracil at 0.04 mM. Meanwhile, we calculate that the binding energies for 2TU2-Au4 and 2TU-Au4 are ca. 70 and 50 kcal/mol, respectively. Those results above imply that the 2TU and 2TU2 conformers can exist stably in the aqueous solution and both of them are vertically chemisorbed on the gold surfaces. For the 2TU, it is adsorbed on the gold surfaces through N1H position and the sulfur atom. While the 2TU2 adsorbed on the gold substrates through the N1 site and its deprotonated sulfur atom.

Adsorption behavior of 6-Mercaptonicotinic acid on self-assembled gold nano-substrates explored by SERS combined with theoretical calculations.

As a typical Raman reporter molecule, 6-Mercaptonicotinic acid (C6H5NO2S, MNA) has three atoms (i.e., N, O, and S), which could be potential to chemically interact with gold nano-surface. In the present report, the adsorption behavior of MNA on self-assembled gold nano-substrates is explored by means of surface-enhanced Raman scattering and theoretical calculations. The results reveal that all the enhanced bands are assigned to in-plane vibrations. The ring triangle breathing coupling with CS stretching band at 1108cm(-)(1) is enhanced a lot and redshifts to 1088cm(-)(1) in the SERS spectra. Furthermore, most of the bands related to N atom are apparently enhanced and shift in the SERS spectra. Based on the surface selection rule, it infers that MNA is vertically chemisorbed on self-assembled gold substrates through the S and the N atoms. The spectroscopic results are further interpreted by the density functional theory (DFT) calculations.

Increasing lysine content of waxy maize through introgression of opaque-2 and opaque-16 genes using molecular assisted and biochemical development.

The low lysine content of waxy maize cannot meet the nutritional requirements of humans, livestock, or poultry. In the present study, the high-lysine genes o2 and o16 were backcrossed into wx lines using the maize high-lysine inbreds TAIXI19 (o2o2) and QCL3021 (o16o16) as donors and the waxy maize inbred line QCL5019 (wxwx) as a receptor. In the triple-cross F1, backcross, and inbred generations, the SSR markers phi027 and phi112 within the wx and o2 genes and the SSR marker umc1121 linked to the o16 gene were used for foreground selection. Background selection of the whole-genome SSR markers was performed for the selected individuals. The grain lysine content was determined using the dye-binding lysine method. The waxiness of the grain was determined with the I2-KI staining and dual-wavelength spectrophotometric analysis. The BC2F2 generation included 7 plants of genotype wxwxo2o2O16_, 19 plants of genotype wxwxo16o16O2_, and 3 plants of genotype wxwxo2o2o16o16. In these seeds, the average amylopectin content was 96.67%, 96.87%, and 96.62%, respectively, which is similar to that of QCL5019. The average lysine content was 0.555%, 0.380%, and 0.616%, respectively, representing increases of 75.1%, 19.9%, 94.3%, respectively, over QCL5019. The average genetic background recovery rate of the BC2F3 families was 95.3%, 94.3%, 94.2%, respectively. Among these 3 wxwxo2o2O16O16 families, 4 wxwxo2o2O16o16 families, and 3 wxwxo2o2o16o16 families, the longest imported parent donor fragment was 113.35 cM and the shortest fragment was 11.75 cM. No significant differences in lysine content were found between the BC2F4 seeds and the BC2F3 seeds in these 10 families. This allowed us to increase the lysine content of waxy corn and produce seeds with excellent nutritional characteristics suitable for human consumption, animal feed, and food processing. This may be of significance in the breeding of high-quality corn and in improvement of the nutrition of humans, livestock, and poultry.

Heterofertilization of the opaque-2 endosperm in maize.

Selection on endosperm traits among individual kernels is very important in maize because the characteristics of the kernel, especially the endosperm, are directly related to quality and yield. However the accuracy of the selection according to endosperm phenotype may be affected by heterofertilization. The objective of this work was to investigate the frequency of heterofertilization of opaque-2 (o2) kernels in maize. Three BC(1)F(1) populations using o2 lines as recurrent parents and some BC(1)F(2) progenies were used to investigate endosperm phenotypes and plant genotypes. The plant genotypes were determined using simple sequence repeat (SSR) markers, phi057 or phi112, which are sequences located within the Opaque-2 (O2) gene; the endosperm phenotypes were observed visually. In the BC(1)F(1) populations, the frequency of heterofertilization was 0 approximately 4.545%. This result indicates that there may be up to a 5% difference between the selections based on endosperm phenotype and plant genotype in a backcross breeding program. Molecular marker assisted selection should be a more accurate selection procedure. In addition, we discuss the relationship between the endosperm heterofertilization of o2 maize and the variations within the O2 locus.