Do thermal effects cause the propulsion of bulk graphene material?

In a recent article, Zhang et al.1 observed the direct propulsion of a bulk graphene sponge when exposed to laser light. They attributed this to the momentum of the light-induced ejected electrons. However, the force provided by the ejected electrons is about 2.7 × 10−11 N (supposing that the average current and the kinetic energy of the ejected electrons are 9 × 10−7 A and 70 eV, respectively), which is far smaller than the gravitational force of a 0.86 mg graphene sponge. From our knowledge of rarefied gas dynamics, the horizontal, vertical and rotational motion of the laser-illuminated graphene sponge could be due to the radiometric force

A method for detecting abnormal behavior of ships based on multi-dimensional density distance and an abnormal isolation mechanism

Abnormal ship behavior detection is essential for maritime navigation safety. Most existing abnormal ship behavior detection methods only build A ship trajectory position outlier detection model; however, the construction of a ship speed outlier detection model is also significant for maritime navigation safety. In addition, in most existing methods for detecting a ship's abnormal behavior based on abnormal thresholds, one unsuitable threshold leads to the risk of the ship not being minimized as much as possible. In this paper, we proposed an abnormal ship behavior detection method based on distance measurement and an isolation mechanism. First, to address the problem of traditional trajectory compression methods and density clustering methods only using ship position information, the minimum description length principle based on acceleration (AMDL) algorithm and Multi-Dimensional Density Clustering (MDDBSCAN) algorithm is used in this study. These algorithms not only considered the position information of the ship, but also the speed information. Second, regarding the issue of the difficulty in determining the anomaly threshold, one method for determining the anomaly threshold based on the relationship between the velocity weights and noise points of the MDDBSCAN algorithm has been introduced. Finally, due to the randomness issue of the selected segmentation value in iForest, a strategy of selectively constructing isolated trees was proposed, thus further improving the efficiency of abnormal ship behavior detection. The experimental results on the historical automatic identification system data set of Xiamen port prove the practicality and effectiveness of our proposed method. Our experiment results show that the proposed method achieves an improvement of about 10% over the trajectory outlier detection based on the local outlier fraction method, about 14% over the isolation-based online anomalous trajectory method in terms of the accuracy of ship position information anomaly detection, and about 3% over the feature fusion method in terms of the accuracy of ship speed anomaly detection. This method improves algorithm efficiency by about 5% compared to the traditional isolation forest anomaly detection algorithm

Experimental study of the influence of drainage conditions on sandstone mechanics and its deformation localization characteristics

In order to study the deformation localization failure characteristics of sandstone under the coupling action of seepage and stress, the triaxial compression tests of sandstone under different drainage conditions were carried out using the visualized triaxial servo control test system combined with three-dimensional digital image correlation (3D-DIC). The rock mechanics, seepage and deformation localization characteristics were analyzed, and the micro-morphology of fracture surface after sandstone failure was analyzed using electron microscope scanning. The results shown that the peak strength and elastic modulus of sandstone under drainage condition were higher than those under undrained condition, the peak strength, elastic modulus and Poisson’s ratio of sandstone increased with the increasing seepage water pressure, the time point of penetration crack and maximum permeability would be advanced. When the seepage water pressure was the same, the localized zone of deformation field cloud map of the sand surface was wider in the undrained condition than that in the drained condition, i.e., the macroscopic crack of rock was more obvious. Water flow under drained condition took away the mineral particles inside the rock and formed holes, the rupture surface of which was smoother than that under undrained condition, whereas flakes cuttings were obviously attached to the surface of the particles under undrained condition. The initiation point of radial deformation localization was consistently higher than that of axial deformation localization for all drainage conditions, with an average increase of 1.23%. The initiation stress levels of the radial and axial deformation localization increased with increasing seepage water pressure, i.e., the initiation time point was earlier. The radial and axial initiation stress level of sandstone under drainage condition were higher than those under undrained condition, with an average increase of 1.85% and 2.21% respectively. When the water pressure was the same, the initiation stress and stress level were more significantly affected by water pressure in the undrained condition than in the drained condition

Advantages of GaN Based Light-Emitting Diodes with a P-InGaN Hole Reservoir Layer

A p-type InGaN hole reservoir layer (HRL) was designed and incorporated in GaN based light-emitting diodes (LEDs) to enhance hole injection efficiency and alleviate efficiency droop. The fabricated LEDs with p-type HRL exhibited higher light output power, smaller emission energy shift and broadening as compared to its counterpart. Based on electrical and optical characteristics analysis and numerical simulation, these improvements are mainly attributed to the alleviated band bending in the last couple of quantum well and electron blocking layer, and thus better hole injection efficiency. Meanwhile, the efficiency droop can be effectively mitigated when the p-InGaN HRL was used

The market challenge of wind turbine industry-renewable energy in PR China and Germany

This paper presents the role of global Industry 4.0 technology management in the growth of the wind turbine industry. The article begins with a brief overview of the Industry 4.0 wind turbine industry development, focusing on factors shaping this development. The legal policies are identified as one of the significant factors, especially in PR China and Germany. A detailed secondary data analysis of the country-specific systems is presented, followed by the analysis of patents and companies in both countries to understand better how the development, management and transfer of technology affected the different factors and the global patterns. An effective approach of acquiring technology for local enterprises as well as market development entry mode for the foreign technology holding companies are both identified. Accessing technology through licensing, entering joint ventures, or acquiring knowledge-intensive companies can be identified as common and often successful industry approaches. To develop, obtain, or maintain competitive advantages in the wind turbine industry, we suggest that the governments issue relevant legislation and regulations to support the upgrading of the industry, and the enterprises can access and manage the technology through the approaches mentioned above

Bioprospecting metagenomics of decaying wood: mining for new glycoside hydrolases

<p>Abstract</p> <p>Background</p> <p>To efficiently deconstruct recalcitrant plant biomass to fermentable sugars in industrial processes, biocatalysts of higher performance and lower cost are required. The genetic diversity found in the metagenomes of natural microbial biomass decay communities may harbor such enzymes. Our goal was to discover and characterize new glycoside hydrolases (GHases) from microbial biomass decay communities, especially those from unknown or never previously cultivated microorganisms.</p> <p>Results</p> <p>From the metagenome sequences of an anaerobic microbial community actively decaying poplar biomass, we identified approximately 4,000 GHase homologs. Based on homology to GHase families/activities of interest and the quality of the sequences, candidates were selected for full-length cloning and subsequent expression. As an alternative strategy, a metagenome expression library was constructed and screened for GHase activities. These combined efforts resulted in the cloning of four novel GHases that could be successfully expressed in <it>Escherichia coli</it>. Further characterization showed that two enzymes showed significant activity on <it>p</it>-nitrophenyl-α-<smcaps>L</smcaps>-arabinofuranoside, one enzyme had significant activity against <it>p</it>-nitrophenyl-β-<smcaps>D</smcaps>-glucopyranoside, and one enzyme showed significant activity against <it>p</it>-nitrophenyl-β-<smcaps>D</smcaps>-xylopyranoside. Enzymes were also tested in the presence of ionic liquids.</p> <p>Conclusions</p> <p>Metagenomics provides a good resource for mining novel biomass degrading enzymes and for screening of cellulolytic enzyme activities. The four GHases that were cloned may have potential application for deconstruction of biomass pretreated with ionic liquids, as they remain active in the presence of up to 20% ionic liquid (except for 1-ethyl-3-methylimidazolium diethyl phosphate). Alternatively, ionic liquids might be used to immobilize or stabilize these enzymes for minimal solvent processing of biomass.</p

Cancer chemoprevention with PV-1, a novel Prunella vulgaris-containing herbal mixture that remodels the tumor immune microenvironment in mice

The herb Prunella vulgaris has shown significant immune-stimulatory and anti-inflammatory effects in mouse models. Here, the effects of a novel Prunella vulgaris-containing herbal mixture, PV-1, were examined in several mouse models for cancer, including chemically induced models of lung and oral cancers as well as syngraft models for lung cancer and melanoma. PV-1, consisting of extracts from Prunella vulgaris, Polygonum bistorta, Sonchus brachyotus and Dictamnus dasycarpus, exhibited no toxicity in a dose escalation study in A/J mice. PV-1 significantly inhibited mouse lung tumor development induced by the lung carcinogens vinyl carbamate and benzo[a]pyrene. PV-1 also hindered the induction of oral squamous cell carcinomas in C57BL/6 mice caused by 4-nitroquinoline-1-oxide. Flow cytometry analysis showed that PV-1 increased the numbers of CD8+ tumor-infiltrating lymphocytes (TILs) and increased the production of granzyme B, TNF-α, and IFN-γ by CD8+ TILs. PV-1 also suppressed granulocytic myeloid-derived suppressor cell numbers (g-MDSCs) and improved the anti‐cancer activity of anti-PD‐1 immunotherapy. These results indicate that PV-1 remodels the tumor immune microenvironment by selectively inhibiting g‐MDSCs and increasing CD8+ TILs within tumors, resulting in decreased immune suppression and enhanced cancer chemopreventive efficacy

Localized delivery of CRISPR/dCas9 via layer-by-layer self-assembling peptide coating on nanofibers for neural tissue engineering

The clustered regularly interspaced short palindromic repeat (CRISPR) systems have a wide variety of applications besides precise genome editing. In particular, the CRISPR/dCas9 system can be used to control specific gene expression by CRISPR activation (CRISPRa) or interference (CRISPRi). However, the safety concerns associated with viral vectors and the possible off-target issues of systemic administration remain huge concerns to be safe delivery methods for CRISPR/Cas9 systems. In this study, a layer-by-layer (LbL) self-assembling peptide (SAP) coating on nanofibers is developed to mediate localized delivery of CRISPR/dCas9 systems. Specifically, an amphiphilic negatively charged SAP− is first coated onto PCL nanofibers through strong hydrophobic interactions, and the pDNA complexes and positively charged SAP+-RGD are then absorbed via electrostatic interactions. The SAP-coated scaffolds facilitate efficient loading and sustained release of the pDNA complexes, while enhancing cell adhesion and proliferation. As a proof of concept, the scaffolds are used to activate GDNF expression in mammalian cells, and the secreted GDNF subsequently promotes neurite outgrowth of rat neurons. These promising results suggest that the LbL self-assembling peptide coated nanofibers can be a new route to establish a bioactive interface, which provides a simple and efficient platform for the delivery of CRISPR/dCas9 systems for regenerative medicine.Agency for Science, Technology and Research (A*STAR)Ministry of Education (MOE)Accepted versio

26S Proteasome Activity Is Down-Regulated in Lung Cancer Stem-Like Cells Propagated In Vitro

Cancer stem cells (CSCs) are a small subset of cancer cells capable of self-renewal and tumor maintenance. Eradicating cancer stem cells, the root of tumor origin and recurrence, has emerged as one promising approach to improve lung cancer survival. Cancer stem cells are reported to reside in the side population (SP) of cultured lung cancer cells. We report here the coexistence of a distinct population of non-SP (NSP) cells that have equivalent self-renewal capacity compared to SP cells in a lung tumor sphere assay. Compared with the corresponding cells in monolayer cultures, lung tumor spheres, formed from human non-small cell lung carcinoma cell lines A549 or H1299, showed marked morphologic differences and increased expression of the stem cell markers CD133 and OCT3/4. Lung tumor spheres also exhibited increased tumorigenic potential as only 10,000 lung tumor sphere cells were required to produce xenografts tumors in nude mice, whereas the same number of monolayer cells failed to induce tumors. We also demonstrate that lung tumor spheres showed decreased 26S proteasome activity compared to monolayer. By using the ZsGreen–cODC (C-terminal sequence that directs degradation of Ornithine Decarboxylase) reporter assay in NSCLC cell lines, only less than 1% monolayer cultures were ZsGreen positive indicating low 26S proteasome, whereas lung tumor sphere showed increased numbers of ZsGreen-positive cells, suggesting the enrichment of CSCs in sphere cultures