A single molecular layer of titanium diselenide (TiSe2) is a promising material for advanced electronics beyond graphene-a strong focus of current research. Such molecular layers are at the quantum ...limit of device miniaturization and can show enhanced electronic effects not realizable in thick films. We show that single-layer TiSe2 exhibits a charge density wave (CDW) transition at critical temperature TC=232±5 K, which is higher than the bulk TC=200±5 K. Angle-resolved photoemission spectroscopy measurements reveal a small absolute bandgap at room temperature, which grows wider with decreasing temperature T below TC in conjunction with the emergence of (2 × 2) ordering. The results are rationalized in terms of first-principles calculations, symmetry breaking and phonon entropy effects. The observed Bardeen-Cooper-Schrieffer (BCS) behaviour of the gap implies a mean-field CDW order in the single layer and an anisotropic CDW order in the bulk.
Gastric cancer (GC) is among the most common malignancy in the world with poor prognosis and limited treatment options. It has been established that gastric carcinogenesis is caused by a complex ...interaction between host and environmental factors. Copy number variation (CNV) refers to a form of genomic structural variation that results in abnormal gene copy numbers, including gene amplification, gain, loss and deletion. DNA CNV is an important influential factor for the expression of both protein-coding and non-coding genes, affecting the activity of various signaling pathways. CNV arises as a result of preferential selection that favors cancer development, and thus, targeting the amplified 'driver genes' in GC may provide novel opportunities for personalized therapy. The detection of CNVs in chromosomal or mitochondrial DNA from tissue or blood samples may assist the diagnosis, prognosis and targeted therapy of GC. In this review, we discuss the recent CNV discoveries that shed light on the molecular pathogenesis of GC, with a specific emphasis on CNVs that display diagnostic, prognostic or therapeutic significances in GC.
The formability and mechanical properties of many engineering alloys are intimately related to the formation and growth of twins. Understanding the structure and chemistry of twin boundaries at the ...atomic scale is crucial if we are to properly tailor twins to achieve a new range of desired properties. We report an unusual phenomenon in magnesium alloys that until now was thought unlikely: the equilibrium segregation of solute atoms into patterns within fully coherent terraces of deformation twin boundaries. This ordered segregation provides a pinning effect for twin boundaries, leading to a concomitant but unusual situation in which annealing strengthens rather than weakens these alloys. The findings point to a platform for engineering nano-twinned structures through solute atoms. This may lead to new alloy compositions and thermomechanical processes.
Summary
Background
Clostridium difficile infection is a major cause of nosocomial diarrhoea.
Aim
To evaluate long‐term (≥90 days) efficacy and safety of faecal microbiota transplantation for C. ...difficile infection and explore the factors affecting the faecal microbiota transplantation outcomes.
Methods
MEDLINE, the Cochrane Library and EMBASE were searched and only observational studies that utilised faecal microbiota transplantation for C. difficile infection with long‐term follow‐up duration (≥90 days) were included. Primary cure rate, overall recurrence rate and early (<90 days) and late (≥90 days) recurrence rate were calculated.
Results
Eighteen observational studies with 611 patients were included. The primary cure rate was 91.2% (95% confidence interval, CI 86.7–94.8%). The overall recurrence rate was 5.5% (95% CI 2.2–10.3%). The early recurrence rate and late recurrence rate were 2.7% (95% CI 0.7–6.0%) and 1.7% (95% CI 0.4–4.2%) respectively. Most adverse events were expected, short‐lived, self‐limited and manageable. The association between faecal microbiota transplantation therapy and adverse events such as inflammatory bowel disease flare, infectious disease and autoimmune disease was a concern but remained insignificant. Old age (≥65 years) was identified as a risk factor for after faecal microbiota transplantation therapy. Upper gastrointestinal administration also results in less frequent primary cure.
Conclusions
Faecal microbiota transplantation seems to be a highly effective and robust therapy for recurrent C. difficile infection. However, more quality studies, such as randomised controlled trials and cohort studies with control groups, are needed to confirm its long‐term efficacy and safety.
Composition of soybean proteins is briefly described. Gels and gelling processes of soybean proteins and other functionalities such as colloidal properties and emulsifying properties are described. ...The effects of temperature, pH, ionic strength, processing conditions such as high pressure, ultrasonic treatment, utilisation of enzyme, chemical modification are also described since they have been found useful to improve the processing and final product.
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•Factors influencing the gelation of soy protein are described.•Factors influencing emulsification using soy protein are described.•How to enhance the gelling or emulsification are described.•Examples of application are described.
Operational flexibility is an important attribute for the design of sustainable power systems with a high share of intermittent renewable energy sources (IRES). Resilience against extreme weather is ...also becoming an important concern. In this study, a modeling and optimization framework for power systems planning, which considers both operational flexibility and resilience against extreme weather events, is proposed. In particular, a set of piece-wise linear models are developed to capture the impact of extreme heat waves and drought events on the performance of the power generation units and on the system load. A method is, also, proposed to incorporate the impact models within a modified optimal power system planning problem that can adequately accommodate high shares of IRES. The framework is applied to a case study based on real future climate projections from the Coupled Model Intercomparison Project phase 5 (CMIP5) under different levels of IRES penetration (up to 50%) and severity of the extreme weather events. A sensitivity analysis is conducted for planning under different Representative Concentration Pathways (RCPs) that cover the impact of different trajectories of greenhouse gas concentration on future climate. In particular, RCPs with increase in radiative forcing of +8.5 Wm-2, +4.5 Wm-2 and +2.6 Wm-2 of the pre-industrial levels are considered. The results demonstrate that significant improvements in terms of load supply under an extreme heat wave and drought events can be achieved following the resilient planning framework proposed, compared to conventional planning methods. It is also shown how renewable generation units can improve the system performance against those extreme climate events. Moreover, the quantitative assessment indicates an important interaction between the resilience of the system and its flexibility, and the compound impact of failing to consider either aspect in the power system design phase.
•A quantitative modeling framework for extreme heat wave and drought events.•An optimization model for resilient power system design against extreme weather impact.•High shares of renewables improve the system resilience against extreme heat wave events.•Investigation of the interaction between the flexibility and resilience of power systems.
Colorectal cancer (CRC) results from the accumulation of genetic alterations, and somatic copy number alterations (CNAs) are crucial for the development of CRC. Genome-wide survey of CNAs provides ...opportunities for identifying cancer driver genes in an unbiased manner. The detection of aberrant CNAs may provide novel markers for the early diagnosis and personalized treatment of CRC. A major challenge in array-based profiling of CNAs is to distinguish the alterations that play causative roles from the random alterations that accumulate during colorectal carcinogenesis. In this view, we systematically discuss the frequent CNAs in CRC, focusing on functional genes that have potential diagnostic, prognostic and therapeutic significance.
Aims
Ansamycins are a family of macrolactams that are synthesized by type I polyketide synthase (PKS) using 3‐amino‐5‐hydroxybenzoic acid (AHBA) as the starter unit. Most members of the family have ...strong antimicrobial, antifungal, anticancer and/or antiviral activities. We aimed to discover new ansamycins and/or other AHBA‐containing natural products from actinobacteria.
Methods and Results
Through PCR screening of AHBA synthase gene, we identified 26 AHBA synthase gene–positive strains from 206 plant‐associated actinomycetes (five positives) and 688 marine‐derived actinomycetes (21 positives), representing a positive ratio of 2·4–3·1%. Twenty‐five ansamycins, including eight new compounds, were isolated from six AHBA synthase gene–positive strains through TLC‐guided fractionations followed by repeated column chromatography. To gain information about those potential ansamycin gene clusters whose products were unknown, seven strains with phylogenetically divergent AHBA synthase genes were subjected to fosmid library construction. Of the seven gene clusters we obtained, three show characteristics for typical ansamycin gene clusters, and other four, from Micromonospora spp., appear to lack the amide synthase gene, which is unusual for ansamycin biosynthesis. The gene composition of these four gene clusters suggests that they are involved in the biosynthesis of a new family of hybrid PK‐NRP compounds containing AHBA substructure.
Conclusions
PCR screening of AHBA synthase is an efficient approach to discover novel ansamycins and other AHBA‐containing natural products.
Significance and Impact of the Study
This work demonstrates that the AHBA‐based screening method is a useful approach for discovering novel ansamycins and other AHBA‐containing natural products from new microbial resources.
Highlights • NRG1 protects against OGD-induced cortical neuronal apoptosis. • NRG1-mediated neuroprotection is blocked by neutralizing NRG1 and ErbB4 inhibition. • GABA receptor agonists have no ...synergistic effect with NRG1. • NRG1-mediated neuroprotection is partly blocked by GABA receptor antagonists. • The NRG1 neuroprotection against brain ischemia is abolished in PV-ErbB4−/− mice.
Prostate cancer (PCa) is considered to be a frequently diagnosed cancer in males with high mortality worldwide, but the molecular mechanism responsible for prostate tumorigenesis and progression ...remains unclear. Increasing evidence has shown that microRNAs (miRNAs) play an important role in PCa. In this review, we focus on the current advances about the role of miRNAs in regulating tumorigenesis and progression of PCa, mainly in suppressing or promoting PCa growth and metastasis, and maintaining the pluripotency of PCa stem cells (PCSC). More studies on miRNAs will provide a better understanding of their regulatory mechanisms in PCa.
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