Effect of Ammonia Fiber Expansion Combined with NaOH Pretreatment on the Resource Efficiency of Herbaceous and Woody Lignocellulosic Biomass.

The most essential issue facing the world today is the provision of energy and sustainable consumption of natural resources. Pretreatment is an essential step to produce biofuels from lignocellulosic biomass. In this study, ammonia fiber explosion (AFEX) combined with NaOH (A-NaOH) pretreatment effects on the characteristics of Pennisetum sinese (herbaceous), oak (hardwood), and camphor wood (softwood) were assessed using enzymatic efficiency analysis, thereby identifying the composition properties of subsequent bio-H2 production. The results show that the lignin removal (84.2%, 59.7%, and 36.7%, respectively) at 5%A-NaOH conditions and enzymatic efficiency (36.2%, 9.7%, and 6.5%, respectively) of Pennisetum sinese (P. sinese), oak, and camphor wood were significantly increased under 4% A-NaOH conditions. Further A-NaOH pretreatment significantly promoted dark fermentation bio-H2 production (152.3, 99.1, and 76.9 mL/g TS, respectively) and volatile acid production (4660.2, 3720.2, and 3496.2 mg/L, respectively) of P. sinese, oak, and camphor wood. These findings show that A-NaOH pretreatment is an effective means of utilization of lignocellulose resources.

Revealing the mechanisms of alkali-based magnetic nanosheets enhanced hydrogen production from dark fermentation: Comparison between mesophilic and thermophilic conditions.

In the present study, a dark fermentation system inoculated with mixed culture bacteria (MCB) was developed using prepared alkali-based magnetic nanosheets (AMNSs) to facilitate biohydrogen (BioH2) production. The highest BioH2 yields of 232.8 ± 8.5 and 150.3 ± 4.8 mL/g glucose were observed at 100 (mesophilic condition) and 400 (thermophilic condition) mg/L AMNSs groups, which were 65.4% and 43.3%, respectively, above the 0 mg/L AMNSs group. The fermentation pathway revealed that AMNSs enhanced the butyrate-type metabolic pathway and the corresponding nicotinamide adenine dinucleotides (NADHand NAD+) ratio, and hydrogenase activity was enhanced in mesophilic fermentation. The interaction of AMNSs and MCB suggested that AMNSs could assist in electron transfer and that the released metal elements might be responsible for elevated hydrogenase activity. AMNSs also promoted the evolution of the dominant microbial community and altered the content of extracellular polymers, leading to increased production of BioH2.

Genetic variants in m6A regulators are associated with gastric cancer risk.

N6-methyladenosine (m6A) modification plays a vital regulatory role in tumorigenesis and development. In this study, we determined that the mRNA expression of IGF2BP1, IGF2BP2 and IGF2BP3, as the m6A modification genes, was significantly increased in gastric cancer (GC) tissues. Using a logistic regression model, we found that novel single-nucleotide polymorphism (SNP) rs9906944 C > T in IGF2BP1 was remarkably associated with a decreased risk of GC in discovery stage (odds ratio (OR) = 0.75, 95% confidence interval (95% CI): 0.60-0.93, P = 8.51 × 10-3). This finding was repeated in an independent Nanjing population (OR = 0.76, 95% CI: 0.59-0.98, P = 3.45 × 10-2). The combined analysis including 2900 GC cases and 3,536 controls confirmed the association between rs9906944 C > T and GC risk (OR = 0.75, 95% CI: 0.64-0.88, P = 5.76 × 10-4). Furthermore, we found that GC patients with higher IGF2BP1 mRNA expression level had prominent poorer overall survival (hazard ratio (HR) = 1.49, 95% CI: 1.16-1.91, logrank P = 1.50 × 10-3). For the first time, our findings suggested the importance of genetic variants in m6A regulators in GC and indicated that IGF2BP1 plays a crucial role in GC. Genetic variants in m6A modification genes may be used for GC risk prediction.

Multiple In-Gap States Induced by Topological Surface States in the Superconducting Topological Crystalline Insulator Heterostructure Sn_{1-x}Pb_{x}Te-Pb.

Superconducting topological crystalline insulators (TCIs) have been proposed to be a new type of topological superconductor where multiple Majorana zero modes may coexist under the protection of lattice symmetries. The bulk superconductivity of TCIs has been realized, but it is quite challenging to detect the superconductivity of topological surface states inside their bulk superconducting gaps. Here, we report high-resolution scanning tunneling spectroscopy measurements on lateral Sn_{1-x}Pb_{x}Te-Pb heterostructures using superconducting tips. Both the bulk superconducting gap and the multiple in-gap states with energy differences of ∼0.3 meV can be clearly resolved on TCI Sn_{1-x}Pb_{x}Te at 0.38 K. Quasiparticle interference measurements further confirm the in-gap states are gapless. Our work demonstrates that the unique topological superconductivity of a TCI can be directly distinguished in the density of states, which helps to further investigate the multiple Dirac and Majorana fermions inside the superconducting gap.

Genetic variants in Ras/Raf/MEK/ERK pathway are associated with gastric cancer risk in Chinese Han population.

The dysregulation of Ras/Raf/MEK/ERK pathway governs occurrence and progression of cancers. In previous studies, genome-wide association studies (GWAS) have identified multiple gene loci related to gastric cancer. However, a great many genetic loci have been missed due to multiple statistical comparisons of GWAS. In this study, Multi-marker Analysis of GenoMic Annotation (MAGMA) was applied to analyze genes in Ras/Raf/MEK/ERK pathway and their single nucleotide polymorphisms (SNPs) based on Chinese GWAS including 1625 gastric cancer cases and 2100 controls. The SNP effects on gastric cancer susceptibility were calculated on the basis of a logistic regression model. Expression quantitative trait loci (eQTL) analysis was performed based on the genotype-tissue expression (GTEx) project. We identified that three SNPs in MAP2K1, rs4287513, rs76906202 and rs11631448 were markedly associated with gastric cancer risk (rs4287513: OR = 1.30, 95% CI = 1.10-1.54, P = 1.92 × 10-3; rs76906202: OR = 0.87, 95% CI = 0.79-0.96, P = 3.72 × 10-3; rs11631448: OR = 1.21, 95% CI = 1.05-1.39, P = 6.74 × 10-3). All the loci were eQTLs for MAP2K1 in normal gastric samples. Moreover, the low expression of MAP2K1 was significantly associated with poor survival in gastric cancer patients. Thus, MAP2K1 might represent a key gene related to gastric cancer in Ras/Raf/MEK/ERK pathway, whereas SNPs in MAP2K1 confer gastric cancer susceptibility by having biological effects on the MAP2K1 expression.

Genome-wide identification of the ARF (auxin response factor) gene family in peach and their expression analysis.

Auxin response factors (ARFs) are important transcription factors to relay auxin signaling. From the Genome Database for Rosaceae (GDR), we identified 17 peach ARF genes (PpARFs) encoding the proteins with three conserved domains. Their gene structure and functional domains were analyzed. Their transcriptional response to exogenous auxin treatment was tested and confirmed. We also expressed PpARF-GFP fusion reporters in tobacco leaves and observed their nuclear localization by fluorescence microscopy. It has been known that ARFs are widely involved in fruit development. We compared the expression pattern of all PpARFs in different tissues including the fruits at different developmental stages of two peach cultivars, "melting" and "stony hard". We found eight PpARFs were more highly expressed in the "melting" peaches compared to "stony hard" peaches, while three PpARFs were more highly expressed in "stony hard" peaches. Among them, the expression difference of PpARF4, PpARF7 and PpARF12 was large, and their function in regulating fruit development and fruit quality was discussed. Our work provides a basis for further exploring the mechanisms underlying auxin regulated peach fruit ripening.

Engineering of Magnetic Coupling in Nanographene.

Nanographenes with sublattice imbalance host a net spin according to Lieb's theorem for bipartite lattices. Here, we report the on-surface synthesis of atomically precise nanographenes and their atomic-scale characterization on a gold substrate by using low-temperature noncontact atomic force microscopy and scanning tunneling spectroscopy. Our results clearly confirm individual nanographenes host a single spin of S=1/2 via the Kondo effect. In covalently linked nanographene dimers, two spins are antiferromagnetically coupled with each other as revealed by inelastic spin-flip excitation spectroscopy. The magnetic exchange interaction in dimers can be well engineered by tuning the local spin density distribution near the connection region, consistent with mean-field Hubbard model calculations. Our work clearly reveals the emergence of magnetism in nanographenes and provides an efficient way to further explore the carbon-based magnetism.

Superconductivity of Topological Surface States and Strong Proximity Effect in Sn1- x Pbx Te-Pb Heterostructures.

Superconducting topological crystalline insulators are expected to form a new type of topological superconductors to host Majorana zero modes under the protection of lattice symmetries. The bulk superconductivity of topological crystalline insulators can be induced through chemical doping and the proximity effect. However, only conventional full gaps are observed, so the existence of topological superconductivity in topological crystalline insulators is still controversial. Here, the successful fabrication of atomically flat lateral and vertical Sn1- x Pbx Te-Pb heterostructures by molecular beam epitaxy is reported. The superconductivity of the Sn1- x Pbx Te-Pb heterostructures can be directly investigated by scanning tunneling spectroscopy. Unconventional peak-dip-hump gap features and fourfold symmetric quasiparticle interference patterns taken at the zero energy in the superconducting gap support the presence of the topological superconductivity in superconducting Sn1- x Pbx Te. Strong superconducting proximity effect and easy preparation of various constructions between Sn1- x Pbx Te and Pb make the heterostructures to be a promising candidate for topological superconducting devices to detect and manipulate Majorana zero modes in the future.

Micellar Aggregation Behavior of Alkylaryl Sulfonate Surfactants for Enhanced Oil Recovery.

Alkylaryl sulfonate is a typical family of surfactants used for chemically enhanced oil recovery (EOR). While it has been widely used in surfactant-polymer flooding at Karamay Oilfield (40 °C, salinity 14,000 mg/L), its aggregation behavior in aqueous solutions and the contribution of aggregation to EOR have not been investigated so far. In this study, raw naphthenic arylsulfonate (NAS) and its purified derivatives, alkylaryl monosulfonate (AMS) and alkylaryl disulfonate (ADS), were examined under simulated temperature and salinity environment of Karamay reservoirs for their micellar aggregation behavior through measuring surface tension, micellar size, and micellar aggregation number. It was found that all three alkylaryl sulfonate surfactants could significantly lower the surface tension of their aqueous solutions. Also, it has been noted that an elevation both in temperature and salinity reduced the surface tension and critical micellar concentration. The results promote understanding of the performance of NAS and screening surfactants in EOR.

Genome-Wide Analysis and Identification of the Aux/IAA Gene Family in Peach.

The Auxin/indole-3-acetic acid (Aux/IAA) repressor genes down-regulate the auxin response pathway during many stages of plant and fruit development. In order to determine if and how Aux/IAAs participate in governing texture and hardness in stone fruit maturation, we identified 23 Aux/IAA genes in peach, confirmed by the presence of four conserved domains. In this work, we used fluorescence microscopy with PpIAA-GFP fusion reporters to observe their nuclear localization. We then conducted PCR-based differential expression analysis in "melting" and "stony hard" varieties of peach, and found that in the "melting" variety, nine PpIAAs exhibited peak expression in the S4-3 stage of fruit maturation, with PpIAA33 showing the highest (>120-fold) induction. The expression of six PpIAAs peaked in the S4-2 stage, with PpIAA14 expressed the most highly. Only PpIAA15/16 showed higher expression in the "stony hard" variety than in the "melting" variety, both peaking in the S3 stage. In contrast, PpIAA32 had the highest relative expression in buds, flowers, young and mature leaves, and roots. Our study provides insights into the expression patterns of Aux/IAA developmental regulators in response to auxin during fruit maturation, thus providing insight into their potential development as useful markers for quantitative traits associated with fruit phenotype.

Constructing magnetic and high-efficiency AgI/CuFe2O4 photocatalysts for inactivation of Escherichia coli and Staphylococcus aureus under visible light: Inactivation performance and mechanism analysis.

Magnetic materials usually exhibit advanced performance in many areas for their easy separating and recycle ability. In this study, silver iodide/copper ferrite (AgI/CuFe2O4) catalysts with excellent magnetic property were successfully synthesized and characterized by a series of techniques. Two typical bacteria Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were applied to estimate the photocatalytic inactivation performance of obtained AgI/CuFe2O4 catalysts. Results revealed that the AgI/CuFe2O4 (12.5% AgI) composite could absolutely inactivate 3 × 109 CFU/mL E. coli and 2.7 × 108 CFU/mL S. aureus cells severally in 50 min and 40 min under visible light irradiation, which showed a much higher photo-disinfection activity than monomers. Transmission electron microscopy was used to study the biocidal action of this nanocatalyst, the results confirmed that the treated E. coli cells were damaged, the nanocatalyst permeated into cells and resulting in death of cells. Besides, it was found that the destruction of bacterial membrane together with substantial leaked potassium ion (K+) which caused by the photo-generated reactive species superoxide radical (O2-) and holes (h+) could be the direct disinfection principles. For a deep insight into practical applications, the influences of different catalyst concentrations and reaction pH were also taken into discussion in details. The overall results indicated the novel photocatalyst with strong redox capacity and outstanding reusability can be widely employed in bacteria elimination.

Diamagnetic Response of Potassium-Adsorbed Multilayer FeSe Film.

Intrigued by the discovery of high-temperature superconductivity in a single unit-cell layer of FeSe film on SrTiO_{3}, researchers recently found large superconductinglike energy gaps in K-adsorbed multilayer FeSe films by angle-resolved photoemission and scanning tunneling spectroscopy. However, the existence and nature of the high-temperature superconductivity inferred by the spectroscopic studies has not been investigated by measurements of zero resistance or the Meissner effect due to the fragility of K atoms in air. Using a self-developed multifunctional scanning tunneling microscope, we succeed in observing the diamagnetic response of K-adsorbed multilayer FeSe films, and thus find a dome-shaped relation between the critical temperature (T_{c}) and K coverage. Intriguingly, T_{c} exhibits an approximately linear dependence on the superfluid density in the whole K adsorbed region. Moreover, the quadratic low-temperature variation in the London penetration depth indicates a sign-reversal order parameter. These results provide compelling information towards further understanding of the high-temperature superconductivity in FeSe-derived superconductors.

Fabrication of visible-light-driven silver iodide modified iodine-deficient bismuth oxyiodides Z-scheme heterojunctions with enhanced photocatalytic activity for Escherichia coli inactivation and tetracycline degradation.

At present, various organic pollutants and pathogenic microorganisms presented in wastewater have severely threatened aquatic ecosystem and human health. Meanwhile, semiconductor photocatalysis technology for water purification has attracted increasingly significant attention. Herein, we successfully constructed a series of novel visible-light-driven (VLD) Bi4O5I2/AgI hybrid photocatalysts with different AgI amounts. Compared with pristine AgI and Bi4O5I2, Bi4O5I2/AgI with the optimal AgI contents exhibited remarkably enhanced photocatalytic performance in probe experiment for Escherichia coli (E. coli) disinfection and tetracycline (TC) degradation. The efficiency for TC degradation and E. coli inactivation reached 82% and 100% in 30 min, respectively. The enhanced electron-hole separation efficiency was responsible for improved photocatalytic activity. In addition, the destruction process of the chemical structure of TC molecules was further investigated by three-dimensional excitation-emission matrix fluorescence spectra (3D EEMs). The activity and crystal phase of the catalysts did not change significantly after four cycles, demonstrating their excellent recyclability and stability of catalysts. The Ag+ ion leaking experiments, radical trapping experiments and ESR tests demonstrated that OH, O2- and h+ were the main active species in photocatalytic disinfection processes. Furthermore, the photocatalytic mechanism of Bi4O5I2/AgI nanomaterials was discussed in detail in conjunction with the energy band structure, and a reasonable Z-scheme interfacial charge transfer mechanism was proposed. This work is expected to provide an efficient water disinfection method.

Quasiparticle interference and nonsymmorphic effect on a floating band surface state of ZrSiSe.

Non-symmorphic crystals are generating great interest as they are commonly found in quantum materials, like iron-based superconductors, heavy-fermion compounds, and topological semimetals. A new type of surface state, a floating band, was recently discovered in the nodal-line semimetal ZrSiSe, but also exists in many non-symmorphic crystals. Little is known about its physical properties. Here, we employ scanning tunneling microscopy to measure the quasiparticle interference of the floating band state on ZrSiSe (001) surface and discover rotational symmetry breaking interference, healing effect and half-missing-type anomalous Umklapp scattering. Using simulation and theoretical analysis we establish that the phenomena are characteristic properties of a floating band surface state. Moreover, we uncover that the half-missing Umklapp process is derived from the glide mirror symmetry, thus identify a non-symmorphic effect on quasiparticle interferences. Our results may pave a way towards potential new applications of nanoelectronics.

Construction of highly efficient and stable ternary AgBr/Ag/PbBiO2Br Z-scheme photocatalyst under visible light irradiation: Performance and mechanism insight.

In this work, the novel ternary AgBr/Ag/PbBiO2Br Z-scheme photocatalysts were synthesized via a CTAB-assisted calcination process. The AgBr/Ag/PbBiO2Br composites were employed for the degradation of rhodamine B (RhB) and antibiotic bisphenol A (BPA) under visible light irradiation. Results showed that the obtained AgBr/Ag-3/PbBiO2Br displayed optimal photocatalytic performance, which could remove almost all RhB within 25 min and effectively decompose 82.3% of BPA in 120 min. Three-dimensional excitation-emission matrix fluorescence spectra (3D EEMs) were utilized for the purposes of fully grasping the behaviors of RhB molecules during the reaction process. Meanwhile, the effects of initial RhB concentration and co-existent electrolytes were investigated from the viewpoint of practical application. In addition, there was no obvious loss in degradation efficiency even after four cycles. The enhanced photocatalytic performances of AgBr/Ag/PbBiO2Br could be credited to the accelerated interfacial charge transfer process and the improved separation of the photogenerated electron-hole pairs. The existence of a small amount of metallic Ag played a significant role in preventing AgBr from being further photocorroded, resulting in the formation of a stable Z-scheme photocatalyst system. This study demonstrated that using metallic Ag as an electron mediator to construct Z-scheme photocatalytic system provided a feasible strategy in promoting the stability of Ag-based semiconductors.

Enhanced Escherichia coli inactivation and oxytetracycline hydrochloride degradation by a Z-scheme silver iodide decorated bismuth vanadate nanocomposite under visible light irradiation.

Novel Z-scheme AgI/BiVO4 photocatalysts were fabricated by a chemical deposition-precipitation approach. The photocatalytic activities of the obtained catalysts were evaluated by disinfection of Escherichia coli (E. coli) and degradation of oxytetracycline hydrochloride (OTC-HCl) under visible-light irradiation. The BA3 (contained 9.09% of AgI) exhibited the highest photocatalytic activity and maintained good stability. It could completely inactivate 7.0×107 CFU/mL of E. coli in 50 min and degrade 80% of OTC-HCl in 60 min. The enhanced photocatalytic activity of AgI/BiVO4 composites could be ascribed to the lower recombination rate of electron-hole pairs. Meanwhile, radical trapping experiments revealed that the superoxide radical (O2-) and holes (h+) were the dominant reactive species in photo-disinfection process. Furthermore, the effects of bacterial initial concentration and inorganic anions were also investigated to optimize the photocatalyst for practical application. This study will give a new insight to construct the effective Z-scheme system for bacterial inactivation and organic pollutants degradation.

Majorana Zero Mode Detected with Spin Selective Andreev Reflection in the Vortex of a Topological Superconductor.

Recently, theory has predicted a Majorana zero mode (MZM) to induce spin selective Andreev reflection (SSAR), a novel magnetic property which can be used to detect the MZM. Here, spin-polarized scanning tunneling microscopy or spectroscopy has been applied to probe SSAR of MZMs in a topological superconductor of the Bi_{2}Te_{3}/NbSe_{2} heterostructure. The zero-bias peak of the tunneling differential conductance at the vortex center is observed substantially higher when the tip polarization and the external magnetic field are parallel rather than antiparallel to each other. This spin dependent tunneling effect provides direct evidence of MZM and reveals its magnetic property in addition to the zero energy modes. Our work will stimulate MZM research on these novel physical properties and, hence, is a step towards experimental study of their statistics and application in quantum computing.

TGF-ß1 induces erlotinib resistance in non-small cell lung cancer by down-regulating PTEN.

BACKGROUND: TKI-acquired resistance is a tough obstacle for effectively treating NSCLC patients with EGFR mutant characteristics. T790M mutations and MET amplifications account for 70% of the acquired resistance, but the causes for the remaining 30% need elucidation. METHODS: We detected TGF-ß1and PTEN expression levels in 51 NSCLC patients undergoing EGFR-TKI treatment using Immunohistochemistry (IHC) assay. We examined erlotinib sensitivity, apoptosis rate, and invasion ability in PC-9 cells and PC-9/TGF-ß1 cells with CCK-8, flow cytometry, and trans-well assays. We examined and analyzed the AKT and ERK pathways' expression levels using western blot. RESULTS: High TGF-ß1 and low PTEN expression levels were correlated with poor EGFR-TKI sensitivity and overall survival in 51 NSCLC samples. In vitro analysis revealed that TGF-ß1 could reduce erlotinib sensitivity, increase anti-apoptosis ability and invasive characteristic in TKI-sensitive PC-9 cell lines by down-regulating PTEN and activating the Akt and ERK pathways. CONCLUSIONS: The results suggest that TGF-ß1 demonstrated another acquired erlotinib resistance by down-regulating PTEN expression.

[Comparison of subgingival debridement efficacy of air polishing and manual scaling].

PURPOSE: To assess the efficacy of subgingival air polishing and traditional manual scaling in 3-6 mm pockets. METHODS: Patients with chronic periodontitis who were in the maintenance phase were randomly assigned to receive subgingival air polishing (experimental group) and manual scaling (control group) in 4 teeth with probing depths of 3 to 6 mm. Clinical variables including plaque index (PI), probing depth (PD), probing on bleeding (BOP) and gingival recession (GR) were recorded at baseline, 7 and 30 days post-treatment. "Pocket closure" [PD ≤ 4 mm and BOP⁻] was also calculated as supplementary data. The data of the 2 groups were compared using paired t test with SAS 8.2 software package. RESULTS: Thirty-one patients were enrolled and PI was 0.8 during the study. Both treatment procedures resulted in significant reductions of PD at day 7 (P<0.0001). BOP% had significant reduction in the experimental group at day 7 (P=0.0390), but there was no significant difference compared to baseline at day 30. Meanwhile, BOP% in the control group demonstrated downward trends during the study, and significant improvement at day 30. The percentages of sites of "pocket closure" significantly increased in both groups (P=0.0329 and P=0.0035, respectively). CONCLUSIONS: The study indicates that subgingival air polishing and traditional manual scaling are both effective for improving clinical variables during supportive periodontal therapy (SPT) in teeth with probing depths of 3 to 6 mm. But the results reveal no significant difference between the 2 modalities.