Accelerated Synthesis of TS-2 Zeolite via 2D Heterogeneous Nucleation for Efficient H2O2 Production.

MEL type c is crucial for addressing energy and environmental crises, yet efficient synthesis remains a challenge due to thermodynamic and kinetic limitations. In this work, TS-2 as typical zeolite is successfully synthesized with high efficiency (12 h with 92% yield) by introducing titanate acid (TA) 2D nanosheet into a hydrothermal synthesis system. A newly defined TA/TS-2 heterostructure is precisely identified as being incorporated into the zeolite framework via a heterogeneous nucleation mechanism. Ab initio molecular dynamics simulations deeply revealed the nucleation and growth mechanisms of the TA/TS-2 heterostructure. The formation energy barrier of Ti─O─Si structural units (88 kJ mol-1) is much lower than that of Si─O─Si units (119 kJ mol-1), leading to more efficient growth of the Ti─O─Si structure. The polarized electronic properties of Ti─O─Si (negative LUMO orbital and larger polarization) further enhanced the reaction probability and stability of Ti─Si bonding. This obtained TA/TS-2 heterostructure also demonstrated superior activity for photocatalytic production of hydrogen peroxide, which can be attributed to the abundant conductive band holes and narrow bandgap. This research provides an effective strategy for using 2D nanosheets to accelerate zeolite production, as well as an in-depth molecular-level insight into the nucleation and growth processes.

Excess copper inhibits the growth of rice seedlings by decreasing uptake of nitrate.

Copper (Cu) toxicity has a deleterious effect on plant growth, and different nitrogen (N) forms have significantly different impacts on the uptake and accumulation of heavy metals by plants. However, it remains unclear how excess Cu inhibits the growth of rice seedlings under different N forms. Here, we examined the mechanism of Cu toxicity inhibiting the growth of rice supplied with different N forms. Rice seedlings were grown in a nutrient solution with 0.81 mmol L-1 N, as ammonium (NH4+), nitrate (NO3-) and NH4+ + NO3-, or without N (0 N) in the presence of 0.2 µmol L-1 CuSO4 or 10 µmol L-1 CuSO4. The inhibition of shoot growth under excess Cu was more pronounced in plants that were supplied with NO3- than NH4+; such inhibition was not induced by higher Cu concentration in shoots. Applied with NO3- alone increased solution pH value up to 6.2, but supplied with NH4+ alone and NH4+ + NO3- decreased solution pH value to 4.0 and 4.2, respectively. The increment of solution pH reduced Cu concentration in shoots of rice supplied with NO3- alone. Copper toxicity decreased NO3- concentrations in rice seedlings that were supplied with NO3- alone but increased the NH4+ concentrations in plants that were supplied with NH4+ or NH4+ + NO3-. High Cu levels reduced the uptake of NO3- in roots by the analysis of net NO3- flux and NO3- assimilation enzymes activity. Under excess Cu, the transcript levels of OsNPF6.5, OsNPF2.2 and OsNPF2.4 genes were suppressed, while OsNRT2.1, OsNRT2.2 and OsNAR2.1 were raised in roots. In conclusion, Cu toxicity inhibits NO3- uptake and upward translocation by modulating the expression level of NO3- transporter genes. The reduction in the concentrations of NO3- and total N decreased shoot growth of rice seedlings when N was supplied as NO3-. Hence, rice seedlings supplied with NO3- had lower shoot biomass than those with NH4+ under Cu stress.

An Anti-FOD Method Based on CA-CM-CFAR for MMW Radar in Complex Clutter Background.

Traditional constant false alarm rate (CFAR) methods have shown their potential for foreign object debris (FOD) indication. However, the performance of these methods would deteriorate under the complex clutter background in airport scenes. This paper presents a threshold-improved approach based on the cell-averaging clutter-map (CA-CM-) CFAR and tests it on a millimeter-wave (MMW) radar system. Clutter cases are first classified with variability indexes (VIs). In homogeneous background, the threshold is calculated by the student-t-distributed test statistic; under the discontinuous clutter conditions, the threshold is modified according to current VI conditions, in order to address the performance decrease caused by extended clutter edges. Experimental results verify that the chosen targets can be indicated by the t-distributed threshold in homogeneous background. Moreover, effective detection of the obscured targets could also be achieved with significant detectability improvement at extended clutter edges.

A Clutter-Analysis-Based STAP for Moving FOD Detection on Runways.

Security risks and economic losses of civil aviation caused by Foreign Object Debris (FOD) have increased rapidly. Synthetic Aperture Radars (SARs) with high resolutions potentially have the capability to detect FODs on the runways, but the target echo is hard to be distinguished from strong clutter. This paper proposes a clutter-analysis-based Space-time Adaptive Processing (STAP) method in order to obtain effective clutter suppression and moving FOD indication, under inhomogeneous clutter background. Specifically, we first divide the radar coverage into equal scattering cells in the rectangular coordinates system rather than the polar ones. We then measure normalized RCSs within the X-band and employ the acquired results to modify the parameters of traditional models. Finally, we describe the clutter expressions as responses of the scattering cells in space and time domain to obtain the theoretical clutter covariance. Experimental results at 10 GHz show that FODs with a reflection higher than -30 dBsm can be effectively detected by a Linear Constraint Minimum Variance (LCMV) filter in azimuth when the noise is -60 dBm. It is also validated to indicate a -40 dBsm target in Doppler. Our approach can obtain effective clutter suppression 60dB deeper than the training-sample-coupled STAP under the same conditions.

Radar HRRP Target Recognition Based on Stacked Autoencoder and Extreme Learning Machine.

A novel radar high-resolution range profile (HRRP) target recognition method based on a stacked autoencoder (SAE) and extreme learning machine (ELM) is presented in this paper. As a key component of deep structure, the SAE does not only learn features by making use of data, it also obtains feature expressions at different levels of data. However, with the deep structure, it is hard to achieve good generalization performance with a fast learning speed. ELM, as a new learning algorithm for single hidden layer feedforward neural networks (SLFNs), has attracted great interest from various fields for its fast learning speed and good generalization performance. However, ELM needs more hidden nodes than conventional tuning-based learning algorithms due to the random set of input weights and hidden biases. In addition, the existing ELM methods cannot utilize the class information of targets well. To solve this problem, a regularized ELM method based on the class information of the target is proposed. In this paper, SAE and the regularized ELM are combined to make full use of their advantages and make up for each of their shortcomings. The effectiveness of the proposed method is demonstrated by experiments with measured radar HRRP data. The experimental results show that the proposed method can achieve good performance in the two aspects of real-time and accuracy, especially when only a few training samples are available.

Real-time monitoring of auxin vesicular exocytotic efflux from single plant protoplasts by amperometry at microelectrodes decorated with nanowires.

Recent biochemical results suggest that auxin (IAA) efflux is mediated by a vesicular cycling mechanism, but no direct detection of vesicular IAA release from single plant cells in real-time has been possible up to now. A TiC@C/Pt-QANFA micro-electrochemical sensor has been developed with high sensitivity in detection of IAA, and it allows real-time monitoring and quantification of the quantal release of auxin from single plant protoplast by exocytosis.

Metabolic engineering of Halomonas bluephagenesis for the production of ethylene glycol and glycolate from xylose.

Halophilic Halomonas bluephagenesis, a natural producer of poly-3-hydroxybutyrate (PHB), was metabolically engineered to synthesize ethylene glycol and glycolate from xylose. Xylose utilization was achieved by overexpressing either the xylonate pathway or the ribulose-1-phosphate pathway. The key genes encoding for xylonate dehydratase and 2-keto-3-deoxy-xylonate aldolase in the xylonate pathway were screened. With further overexpressing aldehyde reductase gene yjgB, ethylene glycol accumulation was improved to 0.91 g/L, accompanied with 1.48 g/L of PHB accumulation. The disruption of native glycolate oxidase was found to be essential for glycolate production, and the defective recombinant strain produced 0.80 g/L glycolate with 1.14 g/L PHB in shake flask cultures. These results indicated that H. bluephagenesis has the potential to produce diverse metabolic chemicals from xylose.

Mesenchymal stem/stromal cells-derived exosomes for osteoporosis treatment.

Osteoporosis is a systemic bone disease, which leads to decreased bone mass and an increased risk of fragility fractures. Currently, there are many anti-resorption drugs and osteosynthesis drugs, which are effective in the treatment of osteoporosis, but their usage is limited due to their contraindications and side effects. In regenerative medicine, the unique repair ability of mesenchymal stem cells (MSCs) has been favored by researchers. The exosomes secreted by MSCs have signal transduction and molecular delivery mechanisms, which may have therapeutic effects. In this review, we describe the regulatory effects of MSCs-derived exosomes on osteoclasts, osteoblasts, and bone immunity. We aim to summarize the preclinical studies of exosome therapy in osteoporosis. Furthermore, we speculate that exosome therapy can be a future direction to improve bone health.

Iterative mutagenesis induced by atmospheric and room temperature plasma treatment under multiple selection pressures for the improvement of coenzyme Q10 production by Rhodobacter sphaeroides.

CoQ10, which has been widely applied in medicine by dietary supplement, possesses important functions in antioxidant process and bioenergy generation. Iterative mutagenesis introduced by atmospheric and room temperature plasma (ARTP) treatment was studied to improve the coenzyme Q10 (CoQ10) production of Rhodobacter sphaeroides (R. sphaeroides), and multiple selection pressures including vitamin K3 (VK3), Na2S and benzoic acid (BA) were adopted for the first time. After two rounds of mutation and screening, a mutant strain R.S 17 was obtained, and the product titer was increased by 80.37%. The CoQ10 titer and cell density reached 236.7 mg L-1 and 57.09 g L-1, respectively, in the fed-batch fermentation, and the CoQ10 content was 22.1% higher than that of the parent strain. In addition, the spectral scanning results indicated the metabolic flux improvement contributing to the CoQ10 production in R.S 17, and the genetic stability was validated. Based on the iterative mutagenesis introduced by ARTP under multiple selection pressures, the promotion of CoQ10 production by R. sphaeroides was achieved. The significant improvement in fermentation performances and the good genetic stability of R.S 17 indicate a potential way for the efficient biosynthesis of CoQ10.

Up-regulation of MTHFD2 is associated with clinicopathological characteristics and poor survival in ovarian cancer, possibly by regulating MOB1A signaling.

BACKGROUND: MTHFD2 is a folate-coupled metabolic enzyme, which has been proved to participant in the metabolic reprogramming and tumor cell-sustaining proliferative capacity. However, the function of MTHFD2 in the development of ovarian cancer and its potential molecular mechanisms is still unclear. MATERIALS AND METHODS: The expression, various mutations, prognosis, and related network signaling pathways of MTHFD2 were analyzed using bioinformatics-related websites, including Oncomine, GEPIA, UCSC, cBioPortal, KM Plotter, TISIDB and TIMER. The prognostic value of MTHFD2 expression was validated by our own ovarian cancer samples using RT-qPCR. The migration ad invasion of ovarian cancer cells were further analyzed by CCK-8 and transwell assay. The Western-blot assay was performed to explore the protein levels of MTHFD2 and MOB1A. RESULTS: We obtained the following important results. (1) MTHFD2 expression was markedly up-regulated in ovarian cancer than normal samples. (2) Among patients with ovarian cancer, those with higher MTHFD2 expression was associated with lower survival rate. (3) The major mutation type of MTHFD2 in ovarian cancer samples was missense mutation. (4) MTHFD2 knockdown inhibited proliferation, migration, invasion, as well as the expression of MOB1A in vitro. CONCLUSION: MTHFD2, as a NAD + -dependent enzyme, accelerated tumor progression by up-regulating MBO1A, suggesting that this protein may be an independent prognostic factor and a potential therapeutic target for future ovarian cancer treatments.

PD-1 engineered cytomembrane cloaked molybdenum nitride for synergistic photothermal and enhanced immunotherapy of breast cancer.

Incomplete tumor ablation and subsequent tumor metastasis usually occur during photothermal anti-tumor processes. The combination of photothermal and immunotherapy has proven to be a promising method to conquer technical challenges. Inhibiting the programmed death ligand-1 (PD-L1)/programmed cell death protein 1 (PD-1) immune pathway represents one of the most successful immunotherapy strategies. Whereas, the PD-L1 expression level significantly differs, leading to a relatively low response rate to the immune checkpoint blockade (ICB) approaches. Therefore, improving the expression level of PD-L1 becomes one potential method to enhance the response rate. Herein, NIH 3T3 cells were educated to steadily express PD-1 protein. Furthermore, the synthesized molybdenum nitride was then coated with PD-1 protein-modified cytomembrane, which endows it with immune checkpoint blocking capability. Moreover, under the irradiation of near-infrared light, the local mild heat released from the molybdenum nitride causes the apoptosis of tumor cells. More importantly, the elevated temperature simultaneously helps elevate the expression level of PD-L1, further enhancing the response rate of ICB. Finally, the PD-1 cytomembrane coatings interact with the upregulated PD-L1, leading to the activation of the immune system. In summary, we confirmed that the PD-1 protein-coated molybdenum nitride could synergistically ablate tumors and avoid metastasis.

Increased expression of KPNA2 predicts unfavorable prognosis in ovarian cancer patients, possibly by targeting KIF4A signaling.

BACKGROUND: Karyopherin α-2 (KPNA2) is a member of karyopherin family, which is proved to be responsible for the import or export of cargo proteins. Studies have determined that KPNA2 is associated with the development and prognosis of various cancers, yet the role of KPNA2 in ovarian carcinoma and its potential molecular mechanisms remains unclear. MATERIALS AND METHODS: The expression and prognosis of KPNA2 in ovarian cancer was investigated using GEPIA and Oncomine analyses. Mutations of KPNA2 in ovarian cancer were analyzed by cBioPortal database. The prognostic value of KPNA2 expression was evaluated by our own ovarian carcinoma samples using RT-qPCR. Subsequently, the cell growth, migration and invasion of ovarian cancer cells were investigated by CCK-8 and transwell assay, respectively. The protein levels of KPNA2 and KIF4A were determined by western blot. RESULTS: We obtained the following important results. (1) KPNA2 and KIF4A wereoverexpressed in ovairan cancer tissues and cells. (2) Among patients with ovarian cancer, overexpressed KPNA2 was associated with lower survival rate. (3) Mutations (R197* and S140F) in KPNA2 will have some influences on protein structure, and then may cause protein function abnormal. (4) KPNA2 konckdown inhibited proliferation, migration, invasion, as well as the expression of KIF4A. CONCLUSION: KPNA2, as a tumorigenic gene in ovarian cancer, accelerated tumor progression by up-regulating KIF4A, suggesting that KPNA2 might be a hopeful indicator of treatment and poor prognosis.

Antioxidant activity of yeast mannans and their growth-promoting effect on Lactobacillus strains.

Yeast mannans from Saccharomyces cerevisiae (123.2 kDa, 40.5 kDa and 21.3 kDa) were prepared. The scavenging abilities of Fe2+, OH˙, and O2˙- and protective capacities against lipid peroxidation and oxidative DNA damage increased with the reduction of the molecular weights of yeast mannans. The highest scavenging abilities of Fe2+, OH˙ and O2˙- (25.32%, 70.8%, and 61.5%) were observed with YM-90, and it showed an anti-lipid peroxidation capacity of 65.82%, which was much stronger than that of vitamin C (VC), with a thiobarbituric acid-reactive substance (TBARS) inhibition rate of 80.41%. However, the highest DPPH scavenging rate (88.7%) was exhibited by YM-30. In addition, the growth-promoting effect of yeast mannans on Lactobacillus strains was further confirmed, and a 54.2% increment of Lactobacillus plantarum ZWR5 cell viability was achieved by YM-90. The results indicated the potential industrial applications of this yeast mannan technology in therapeutic and nutraceutical production.

Open simultaneous saccharification and fermentation of l-lactic acid by complete utilization of sweet sorghum stalk: a water-saving process.

A complete and efficient utilization of sweet sorghum stalk including sweet sorghum juice (SSJ) and sweet sorghum bagasse (SSB) was achieved via the open simultaneous saccharification and fermentation (SSF) of l-lactic acid. To simplify the pretreatment process and reduce water consumption, a combined hydrolysis approach was applied and the NaOH-pretreated liquor (SL) was utilized as a partial neutralizing agent. In order to further enhance the product titer, the acid hydrolysate of SSJ (SSJAH) was fed, and MgO was used as a neutralizing agent. A product titer of 94 g L-1 was obtained with a productivity of 1.55 g L-1 h-1, and the yield reached 98.31%. Totally, 274.79 g l-lactic acid was produced from 1 kg sweet sorghum stalk, and 83.22% water was saved compared with the previous study based on alkali pretreatment of SSB. This study provides an effective process for l-lactic acid biosynthesis from lignocellulosic substrates.

Recent Progress in Electrode Materials for Nonaqueous Lithium-Ion Capacitors.

As a new type of energy-storage devices, lithium-ion capacitors (LICs) are designed to deliver high energy densities, high power densities, and long lifespan by integrating the battery-type anodes and capacitor-type cathodes. Achieving high energy and power density simultaneously is the challenge of LICs, which is mainly determined by the cathode and anode materials. In this mini-review, basing on the working principles of LICs, we discuss the categories and electrochemical performance as well as the matching strategies of the cathodes and anodes. In anodes, we focus on summarizing the structural design of the prelithiation transition-metal compounds based materials. In cathodes, we emphasize discussing the fabrication and morphology adjustment of the low dimensional carbon materials. Finally, the prospects and challenges confronting future research and development of LICs are provided.

Analyses of DNA Methylation Involved in the Activation of Nuclear Karyopherin Alpha 2 Leading to Identify the Progression and Prognostic Significance Across Human Breast Cancer.

BACKGROUND: Karyopherin alpha 2 (KPNA2) is a nuclear import factor that plays a crucial role in nucleocytoplasmic transport, as well as cell proliferation, migration, and invasion in several cancers. However, the roles of KPNA2 in breast cancer as well as the underlying molecular mechanisms have not been elucidated. MATERIALS AND METHODS: To evaluate gene expression alterations during breast carcinogenesis, KPNA2 expression was analyzed using the Gene Expression Profiling Interactive Analysis and Oncomine analyses. The correlation between methylation and expression was analyzed using the MEXPRESS tool, UALCAN cancer database, and cBioPortal browser. Then, the expression and prognostic value of KPNA2 were investigated by our own breast cancer samples using RT-PCR. KPNA2 methylation level was detected by methylation-specific PCR. RESULTS: We obtained the following important results. (1) KPNA2 expression was significantly higher in breast cancer than normal samples and regulated by aberrant DNA hypomethylation of promoter region. (2) Among patients with breast cancer, those with higher KPNA2 expression had a lower survival rate. (3) The major mutation type of KPNA2 in breast cancer samples was missense mutation. (4) Homer1 was able to promote breast cancer progression may be through upregulating TPX2 expression. CONCLUSION: Our findings suggest that aberrant DNA hypomethylation of promoter regions contributes to the aberrant expression of KPNA2 in breast cancer, which might be a potential indicator of poor prognosis.

RNA-seq reveals the salt tolerance of Ipomoea pes-caprae, a wild relative of sweet potato.

Wild relatives of crops are often rich in genetic resources and provide great possibilities for crop improvement. Ipomoea pes-caprae is one of the wild relatives of sweet potato and has high salt tolerance. Transcriptomes in the treatment and control groups at various times were sequenced to identify salt tolerance genes and salt response pathways. A total of 40,525 genes were obtained, of which 2478 and 3334 were differentially expressed in the roots and leaves of I. pes-caprae under salt stress, respectively. Identification of candidate genes revealed that the mitogen-activated protein kinase (MAPK) signaling pathway of plants and plant hormone signal transduction participates in the salt signal of I. pes-caprae under salt stress. Homology to ABI2 (HAB2) and Clade A protein phosphatases type 2C (HAI1), which encode two protein phosphatases 2C (PP2C) in the abscisic acid (ABA) signal pathway, were continuously up-regulated upon salt stress, indicating their key role in the salt signal transduction pathway of I. pes-caprae. The expression of EIN3-binding F-box protein 1 (EBF1) in the ethylene signaling pathway was also up-regulated, revealing that the salt tolerance of I. pes-caprae was related to the scavenging of reactive oxygen species (ROS). This study provides insights into the mechanism of salt-tolerant plants and the mining of salt-tolerant genes in sweet potato for the innovation of germplasm resources.

Long noncoding RNA CCAT2 can predict metastasis and a poor prognosis: A meta-analysis.

BACKGROUND: Colon cancer associated transcript 2 (CCAT2), a novel long non-coding RNA (lncRNA), plays a key role in tumorigenesis. This meta-analysis systematically summarizes the relationship between CCAT2 and cancers. METHODS: A comprehensive, computerized literature search was conducted in PubMed, Cochrane library, Chinese National Knowledge Infrastructure, and Chinese Wan Fang database. Odds ratios (ORs), hazard ratios (HRs) and their 95% confidence interval (95% CI) were calculated to assess the effect size. A total of 9 studies were enrolled in this meta-analysis, which was performed by Revman5.3 software and Stata12.0. RESULTS: Our meta-analysis indicates that patients with elevated expression of CCAT2 are prone to developing distant metastasis (DM) (OR=12.42; 95% CI=5.77-26.74; P < 0.00001), which is associated with a tendency for lymph nodes metastasis (LNM) (OR=3.60 95% CI=1.65-7.87, P=0.001). Further analyses reveal that patients with high CCAT2 expression have poorer overall survival (OS) (HR=1.53, 95% CI=1.15-2.02, P=0.003, random-effects) and progression-free survival (PFS) (HR=2.88, 95% CI=1.81-4.56, P < 0.00001, fixed-effects). CONCLUSIONS: Therefore, CCAT2 may be a potential novel biomarker for indicating clinical outcomes of human cancers.

Abnormal expression levels of BMP15/Smad1 are associated with granulosa cell apoptosis in patients with polycystic ovary syndrome.

Polycystic ovary syndrome (PCOS) is a common endocrine disorder that affects reproductive dysfunction and metabolism in women of childbearing age. An increasing number of studies have suggested that the bone morphogenetic protein 15 (BMP15) signalling pathway serves an important role in the pathogenesis of PCOS; however, the full mechanism remains unknown. The present study revealed that intrinsic follicular dysplasia may be associated with regulation disorders of ovarian granulosa cell apoptosis. Compared with the control group, body mass index, luteinising hormone and testosterone levels were significantly increased (P<0.05). The percentage of S phase cells was significantly higher, cells in G2/M phase cells was significantly lower, and cells undergoing apoptosis was significantly higher in the PCOS group compared with the control group (P<0.05). The expression levels of B­cell lymphoma 2 was significantly decreased in granulosa cells of PCOS group, whereas the expression of caspase­3 was higher than the control group (P<0.05). The rate of apoptosis of granulosa cells was measured by a terminal deoxynucleotide transferase dUTP nick­end labelling assay. The relative mRNA expression levels of BMP receptor 2 and SMAD1 were significantly decreased in granulosa cells in the PCOS group compared with the control (P<0.05). In addition, the expression of BMP15 in follicular fluid and Smad1 in granulosa cells was significantly decreased in the PCOS group compared with the control (P<0.05). The data suggested that the BMP15/Smad1 signalling pathway may be involved in granulosa cell apoptosis, and may be a target for clinical treatment for PCOS.

Promotion of photosynthesis in transgenic rice over-expressing of maize C4 phosphoenolpyruvate carboxylase gene by nitric oxide donors.

We determined the effects of exogenous nitric oxide on photosynthesis and gene expression in transgenic rice plants (PC) over-expressing the maize C4pepc gene, which encodes phosphoenolpyruvate carboxylase (PEPC). Seedlings were subjected to treatments with NO donors, an NO scavenger, phospholipase inhibitors, a Ca(2+) chelator, a Ca(2+) channel inhibitor, and a hydrogen peroxide (H2O2) inhibitor, individually and in various combinations. The NO donors significantly increased the net photosynthetic rate (PN) of PC and wild-type (WT), especially that of PC. Treatment with an NO scavenger did inhibit the PN of rice plants. The treatments with phospholipase inhibitors and a Ca(2+) chelator decreased the PN of WT and PC, and photosynthesis was more strongly inhibited in WT than in PC. Further analyses showed that the NO donors increased endogenous levels of NO and PLD activity, but decreased endogenous levels of Ca(2+) both WT and PC. However, there was a greater increase in NO in WT and a greater increase in PLD activity and Ca(2+) level in PC. The NO donors also increased both PEPC activity and pepc gene expression in PC. PEPC activity can be increased by SNP alone. But the expression of its encoding gene in PC might be regulated by SNP, together with PA and Ca(2+).