Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Quasi Time-Fuel Optimal Control Strategy for dynamic target tracking

A quasi time-fuel optimal control strategy to solve the dynamic tracking problem of unmanned systems is investigated. It could bring the biggest advantage into full play in the field of switching tracking for multiple targets, such as the multi-target strike of weapons and the rapid multi-target grabbing of robots on industrial assembly lines. Compared with the time-fuel optimal control studied before, the proposed controller retains the advantages of optimal control when switching between multiple dynamic targets, and overcomes the high-frequency oscillation problem of the system under the discontinuous control strategies. Moreover, the asymmetry of friction load, which can affect the dynamic performance of the system, is also considered. Therefore, the novel control law proposed in this brief can make the corresponding system achieve the desired transient performance and satisfactory steady-state performance when switching between multiple dynamic targets. The experiment results based on the visual tracking turntable verify the superiority of the proposed method

Identification of A Cold-active Lipase Producing Strain, Optimization of Fermentation Conditions and Analysis of Enzymatic Properties

To screen strains with high production of cold-active lipase and optimize enzyme production conditions, as well as to provide production information for the industrial development of lipase, a cold-active lipase producing strain was screened from soil samples in Mohe County, Heilongjiang Province, and identified as Serratia plymuthica by morphological identification, physiological and biochemical experiments and molecular biology. The effects of different factors such as temperature, pH, loading volume, inoculum, carbon source, nitrogen source, metal ion and inducer on the enzyme production of the strain were investigated by single-factor experiments, as well as the optimization of the addition of olive oil, peptone and loading volume by Plackett-Burman experiment, hill climbing test and response surface design. The results showed that the optimal enzyme production conditions were 20 ℃, pH7.5, loading volume 42 mL, inoculum 0.5%, 20 g/L maltose, 14 g/L peptone, 0.5 g/L MgSO4·7H2O and 46 mL/L olive oil. The lipase activity under this optimized condition was 98.05 U/mL, which was 5.85 times higher than that before optimization. The results of enzymatic properties showed that the optimum temperature of this lipase was 30 ℃, which was a low temperature lipase, and the optimum reaction pH was 7. Mg2+ could obviously promote the enzyme activity. The organic solvents methanol and ethanol obviously inhibited the enzyme activity, while n-hexane could obviously promote the enzyme activity. The conclusion can provide some theoretical basis and methodological guidance for the development and utilization of microbial resources and industrial production of low-temperature lipase

Single layer diamond - A new ultrathin 2D carbon nanostructure for mechanical resonator

The single layer diamond – diamane, a two-dimensional (2D) form of diamond with a bilayer sp3 carbon nanostructure, has been initially predicted in 2009, while its experimental synthesis has only been reported very recently. This work carries out a comprehensive study on the vibrational properties of diamane nanoribbon (DNR) targeting the ultra-sensitive sensing applications. Based on in silico studies, it is found that the DNR resonator possesses a higher natural frequency and a large quality factor (Q-factor) on the order of 105 higher than those of a bilayer nanoribbon resonator. Under pre-tensile strain, the natural frequency of the DNR resonator receives a remarkable increase and its Q-factor maintains a high magnitude yielding to an extremely high figure of merit on the order of 1015. It is further found that the randomly distributed surface hydrogenation exerts negligible influence on the vibrational properties of the DNR resonator. However, an unevenly distributed hydrogenation results in out-of-plane deformation and significantly changes its vibrational properties. It is additionally found that the stacking configuration of the diamane leads to negligible influence on its vibrational properties. This study reveals that the DNR resonator has excellent vibrational properties, which are promising for the construction of ultra-sensitive resonator-based sensors.</p

Flexible Sensors Based on Organic–Inorganic Hybrid Materials

Flexible electronic devices are widely used in daily life. Among them, flexible sensors are widely studied by their potential for extensive applications. Materials are one of the essential foundations for making electronic devices. Due to the excellent unique properties of organic and inorganic hybrid materials, they are widely used in the manufacture of flexible sensors. Flexible sensor technology is developed by combining organic and inorganic materials and these hybrid materials can ensure the high frequency and high-speed conductive property of a device while making the device flexible. In this review, the main three elements of sensors are mentioned and the materials selections in different elements are reviewed. After investigating the materials’ performance requirements of sensors, the performance of hybrid materials in sensors is comprehensively summarized according to the type of the sensor. Finally, some challenges and future directions of development are summarized and presented for flexible sensors based on such promising materials.</p

Catalytic Oxidation and Desulfurization of Calcium-Hydroxide Gypsum Wet Flue Gas Using Modified MIL-53(Fe)

MIL-53(Fe) was prepared and modified with benzoic acid to prepare MIL-53(Fe)-BA additive, which was used to improve the catalytic oxidation rate of sulfite, prevent the scaling of the desulfurization tower, and improve the desulfurization efficiency during the wet flue gas desulfurization (WFGD) process of power plants. MIL-53(Fe)-BA exhibits abundant Lewis acid sites because of the appearance of coordination unsaturated Fe atoms. Due to the excellent sorption capacity, Ca(OH)2 was used as the main SO2 desulfurizer. The composite desulfurizers were prepared by mixing MIL-53(Fe)-based additives and Ca(OH)2, and were characterized by SEM, XRD, and FT-IR. A desulfurization unit was set up at laboratory scale to study the effect of catalytic oxidation additives on sulfite oxidation and desulfurization efficiency. The results showed that the addition of MIL-53(Fe)-BA can increase the oxidation capacity of sulfite by 159%, and greatly improve the desulfurization efficiency. These composite desulfurizers broaden the adaptability of the desulfurizing system to high-sulfur coals, and provide support for improving the desulfurizing efficiency of power plants

Wood-Inspired Ultrafast High-Performance Adsorbents for CO₂ Capture

Under favorable regeneration conditions (120 °C, 100% CO2), ultrafast adsorption kinetics and excellent long-term cycle stability are still the biggest obstacles for amine-based solid CO2 adsorbents. Inspired by natural wood, a biochar with a highly ordered pore structure and excellent thermal conductivity was prepared and used as a carrier of organic amines to prepare ideal CO2 adsorbents. The results showed that the prepared adsorbent has a very high adsorption working capacity (4.23 mmol CO2·g–1), and its performance remains stable even after 30 adsorption–desorption cycles in the harsh desorption environment (120 °C, 100% CO2). Due to the existence of the hierarchical structure, the adsorbent exhibited ultra-fast adsorption kinetics, and the reaction rate constant is 37 times higher than that of traditional silica. This adsorbent also showed a very low regeneration heat of 1.64 MJ·kg–1 (CO2), which is especially important for the practical application. Therefore, these biochar-based adsorbents derived from natural wood make the CO2 capture process promising

Diagnostic Value of SFRP1 as a Favorable Predictive and Prognostic Biomarker in Patients with Prostate Cancer

<div><p>Growing genetic and molecular biological evidence suggests that the disruption of balance between Secreted Frizzled-Related Protein-1 (SFRP1) and β-catenin plays an important role in the initiation and development of multiple cancers. The aim of this study was to examine whether the expression of SFRP1 and β-catenin is associated with the clinical-pathologic features of patients with prostate cancer (PCa), and to evaluate their potential roles as predictive and prognostic biomarkers. In this study, a total of 61 patients with PCa and 10 patients with benign prostatic hyperplasia were included, and we showed that the expression of SFRP1 and β-catenin was correlated with the Gleason score, survival rate and response for endocrine therapy of PCa. The survival rates of PCa patients with low SFRP1 expression (P = 0.016) or high β-catenin expression (P = 0.004) were significantly poorer. A negative correlation (r = -0.275, P = 0.032) between SFRP1 and β-catenin was observed by Chi-square test. Multivariate analysis suggested that SFRP1 (hazard ratio, 0.429; 95% confidence intervals, 0.227–0.812; P = 0.009) may serve as an independent predictive and prognostic factor for PCa. We also showed that the protein and mRNA levels of SFRP1 in androgen-dependent PCa cell line LNCaP were significantly higher than those in androgen-independent PCa cell lines DU145 and PC3. However, the protein level of β-catenin in LNCaP cells was significantly lower than that in DU145 and PC3 cells, and no significant difference of β-catenin mRNA level was observed in LNCaP, DU145 and PC3 cells. Bisulfite sequencing PCR assay revealed significantly lower methylation level of <i>SFRP1</i> promoter in LNCaP cells than that in DU145 and PC3 cells. Taken together, these findings suggest that SFRP1, which expression inversely correlates with that of β-catenin, is a favorable predictive and prognostic biomarker.</p></div