First-Principles Modeling of Equilibration Dynamics of Hyperthermal Products of Surface Reactions Using Scalable Neural Network Potential

Equilibration dynamics of hot oxygen atoms following O2 dissociation on Pd(100) and Pd(111) surfaces are investigated by molecular dynamics simulations based on a scalable neural network potential enabling first-principles description of O2 and O interacting with variable Pd supercells. We find that to accurately describe the equilibration dynamics after dissociation, the simulation cell length necessarily exceeds twice the maximum distance of equilibrated oxygen adsorbates. By analyzing hundreds of trajectories with appropriate initial sampling, the measured distance distribution of equilibrated atom pairs on Pd(111) is well reproduced. However, our results on Pd(100) suggest that the ballistic motion of hot atoms predicted previously is a rare event under ideal conditions, while initial molecular orientation and surface thermal fluctuation could significantly affect the overall post-dissociation dynamics. On both surfaces, dissociated oxygen atoms remain primarily locate their nascent positions and then randomly cross bridge sites nearby

Epidermal growth factor receptor in breast carcinoma: association between gene copy number and mutations

<p>Abstract</p> <p>Background</p> <p>The epidermal growth factor receptor (EGFR) is an available target of effective anti-EGFR therapy for human breast cancer. The aim of this study was to assess the presence of EGFR gene amplification and mutations in breast cancer and to analyze the association between the statuses of these two gene alterations.</p> <p>Materials and methods</p> <p>EGFR gene amplification and mutations were investigated in formalin-fixed, paraffin-embedded tissues from 139 Chinese female patients with breast cancer by means of fluorescence in-situ hybridization (FISH) and fluorescently labeled real-time quantitative polymerase chain reaction (RT-PCR), respectively.</p> <p>Results</p> <p>EGFR gene amplification was observed in 46/139 (33.1%) of cases by FISH. Based on RT-PCR, 2/139 (1.4%) samples had EGFR gene mutations. Overall, only 1 (0.7%) of the cases was identified with both whole gene amplification and mutation, and 92 (66.2%) of cases were negative for both. High gene copy numbers of EGFR had significant correlation with the occurrence of EGFR protein expressions (P = 0.002).</p> <p>Conclusion</p> <p>In this study, EGFR mutations were presented in only two samples, indicating that EGFR mutations should not be employed in future trials with anti-EGFR therapies for breast cancer. However, EGFR whole gene amplification is frequently observed in patients with breast cancer. It will be of significant interest to investigate whether EGFR gene copy number is a suitable screening test for EGFR-targeted therapy for breast cancer.</p

Insights into Land Plant Evolution Garnered from the Marchantia polymorpha Genome.

The evolution of land flora transformed the terrestrial environment. Land plants evolved from an ancestral charophycean alga from which they inherited developmental, biochemical, and cell biological attributes. Additional biochemical and physiological adaptations to land, and a life cycle with an alternation between multicellular haploid and diploid generations that facilitated efficient dispersal of desiccation tolerant spores, evolved in the ancestral land plant. We analyzed the genome of the liverwort Marchantia polymorpha, a member of a basal land plant lineage. Relative to charophycean algae, land plant genomes are characterized by genes encoding novel biochemical pathways, new phytohormone signaling pathways (notably auxin), expanded repertoires of signaling pathways, and increased diversity in some transcription factor families. Compared with other sequenced land plants, M. polymorpha exhibits low genetic redundancy in most regulatory pathways, with this portion of its genome resembling that predicted for the ancestral land plant. PAPERCLIP

Research progress and framework on the simulation and assessment of fish habitat degradation in lakes

Lake ecosystems play a crucial role in maintaining global biodiversity, flood storage, and water purification. Fish living in lakes and their habitat quality are significant indicators of the overall health of the lake ecosystem. In recent years, the impact of climate change and human activities on lake habitats has become an important research topic. In this paper, using fish as an indicator species, the habitat factors of lake fish were classified into hydrological factors, water quality factors, topographic and substrate factors, and biological factors, based on which the influence mechanism of each factor of the lake habitat system on fish was sorted out. We used the VOSviewer bibliometric analysis tool to visualize the knowledge map and identify current research hotspots and development trends related to simulation and assessment methods for lake fish habitats. Additionally, we reviewed the research progress of four types of lake habitat models. Based on the current research perspectives and shortcomings, a research framework for assessing the risk of lake habitat degradation is proposed, which consists of four parts. This framework could establish a theoretical foundation for the protection and restoration of lake ecosystems

Resilience-oriented planning method of local emergency power supply considering V2B

Private electric vehicles (EVs) have great potential to conduct emergency power supply, considering the rapid development of EVs and vehicle-to-building (V2B) technologies. To enhance the resilience of the building power supply, charging piles can be upgraded to support bi-directional power supply, thus enabling EVs to help restore the buildings affected by disasters. A planning method for the charging piles’ upgrade is proposed. First, a scenario set is generated to consider the influence of uncertainties during the planning period. The uncertainties of disasters, EVs, and building load are included. Then, a two-stage stochastic programming model is established to decide the upgrade plan. Pre-disaster decisions are made in the first stage and the building is restored in the second stage. The method is applied to two different types of buildings and the test results verify the effectiveness of the proposed method

Ecological Flow Assessment to Improve the Spawning Habitat for the Four Major Species of Carp of the Yangtze River: A Study on Habitat Suitability Based on Ultrasonic Telemetry

Four major species of Chinese carp, namely black carp (Mylopharyngodon piceus), grass carp (Ctenopharyngodon idellus), silver carp (Hypophthalmichthys molitrix) and bighead carp (Hypophthalmichthys nobilis), are important economic freshwater fish varieties in China. They primarily inhabit and breed in the Yangtze River. Unfortunately, the construction and operation of the Gezhouba Dam and the Three Gorges Dam have dramatically changed the hydrodynamic conditions in the middle reaches of the Yangtze River, leading to a sharp decline in the reproduction rates of these carp. The egg abundance of the four species of carp downstream from the Three Gorges Dam reached 8.35 billion in 1965, but abundance during 2005&ndash;2012 was only 0.25 billion. One of the main reasons was that the hydrodynamic conditions of the spawning ground could not meet the four species&rsquo; breeding requirements. However, due to the limitations of traditional detection tools, the spawning characteristics of these four species of carp were still unclear. In this study, the ultrasonic telemetry and a three&ndash;dimensional hydrodynamic model were utilized to build the habitat suitability index (HSI) curves for the four species of carp. The habitat suitability model was then built based on HSI curves to assess spawning habitat quantity under different flow conditions. Finally, the habitat suitability model in the Yidu spawning ground was validated using 32 groups of sampling data in 2015 and 2017. The statistical results showed that the most suitable velocity ranged from 0.78 m/s to 0.93 m/s. The most suitable water depth ranged from 14.56 m to 16.35 m, and the most suitable Froude number ranged from 0.049 to 0.129. The habitat suitability model simulation results indicated that when the discharge was between 15,000 m3/s and 21,300 m3/s, the weighted usable area (WUA) values in both the Yidu and Zhicheng spawning grounds would remain at a high level. The validation results showed that most spawning activities occurred at a high level of WUA, and that the daily spawning egg numbers increased with the WUA value. Therefore, discharges of between 15,000 m3/s and 21,300 m3/s could be recommended as ecological operation target flows. We propose a feasible ecological operation scheme by setting the initial flow at 15,000 m3/s and maintaining the daily discharge increase at 1500 m3/s for 4 days

Optimization research based on local exhaust of oil mist particles in cutting machine tool

Oil particles generated from metalworking fluids(MWFs) in machining process can lead serious health problem to operator. Local exhaust hood is an effective engineering method to capture oil particles and other contamination which is wildly used in manufacture workshop. In this paper, exhaust hood capture efficiency with various height, air volume and particle size was gotten by Computational Fluid Dynamic(CFD) technology. Though further analysis of the CFD result, feature air velocity was introduced. Then an equation of feature velocity and capture efficiency was established by multi regression method. According to this equation one improvement solution was studied: Set to flexible enclosure for up exhaust hood. The solution raised particle capture efficiency on each size significant, the result is equivalent to low down up exhaust hood for 60cm

Structure of a novel PTH-related peptide hPTH' and its interaction with the PTH receptor

We have previously shown that a recombinant human PTH fragment, Pro-Pro-[Arg11] hPTH (134)-Pro-Pro-Asp (hPTH'), could be a potentially better and more cost-effective therapeutic agent than PTH (134) on osteoporosis. In this report, we characterized the solution conformations of hPTH' by NMR spectroscopy and modeled the interactions between the hPTH' and the PTH receptor. By comparing it with PTH (134) structures and their respective interactions with the PTH receptor, we identified two segments of helix extending from Ile5 to Met8 and from Glu22 to Gln29 with a divided kink between the two helixes around Arg20. Mutated arginine makes hPTH' fill the receptor cavity better as well as forms hydrogen bonds with Val193. Understanding the ligand receptor interactions will help us design small molecules to better mimic the activities of PTH. Copyright (c) 2012 European Peptide Society and John Wiley & Sons, Ltd.Natural Science Foundation of China [30730026]; Program of Shanghai Subject Chief Scientist [09XD1405100