Search

• The variation of color results in considerable surface temperature differences. • Surface temperature difference is strongly correlated with solar radiation received. • Thermal inertia of the material greatly affects the surface temperature change trend. In the design of urban buildings, regionality is take into account to ensure that the colors and materials used are consistent with the surrounding environment and urban development. This helps maintain the urban characteristics and local cultural values. However, the effects on the thermal environment are typically not considered in this process. To explore the rationality of the current urban design guidance, a field study was conducted in Xi'an-iHarbour. The surface temperatures of buildings with different colors and materials were investigated, and the solar radiation received by these surfaces was measured. The results show that variations in surface colors can lead to considerable differences in surface temperature, which are strongly and positively correlated with the amount of solar radiation received. In addition, the thermal inertia of the material can significantly influence the daily variation in the surface temperature. The current guidelines for Xi'an urban design have been found to be inappropriate. Low-thermal-inertia materials and light colors have been suggested to improve the urban thermal environment of Xi'an. The findings of this research provide insights on the thermal performance of building surfaces and provide ideas for the architectural design of other cities that also have thermal environmental concerns. [ABSTRACT FROM AUTHOR]

To effectively improve the power dispatching, the prediction accuracy of wind power has been the concern of many scholars for many years. The wind power prediction problem is actually equivalent to the wind speed prediction problem. Based on linear regression (LR) and variational mode decomposition (VMD), in this paper, we proposed an efficient hybrid method to predict wind speed. In the proposed method, the VMD is used to decompose the signal of wind speed into several sub-signal. Compared with the original wind-speed series, each sub-signal is a more stable subsequence signal. Then, we used the LR method to predict each subsequence signal. Eventually, we obtain the final prediction results of the original wind speed series merged the forecasting values of all subsequences signal. We selected two data to test our proposed method in our experiment. Compared with several comparison methods, we found that our proposed methods has better prediction performance than other methods from the experimental results. [ABSTRACT FROM AUTHOR]

ABSTRACT The crystallinity of polyelectrolytes has long been known to affect their ionic conductivity, but the effects of water of hydration on polyelectrolyte structure are not commonly studied. Here, polymer complexes consisting of poly(ethylene oxide) (PEO) with magnesium chloride (anhydrous MgCl2, MgCl2·4H2O, and MgCl2·6H2O, respectively) have been prepared by a mixed-solvent method. Fourier transform-infrared measurements indicate each magnesium chloride salt can coordinate with PEO to form a complex. The structures of (PEO)xMgCl2·4H2O and (PEO)xMgCl2·6H2O complexes are similar, whilst the structure of (PEO)xMgCl2 complex is different to both. Wide angle X-ray diffraction studies indicate in each polymer complex system the crystallization of PEO is depressed by the interaction of magnesium cation with the ether oxygen of PEO. PEO in (PEO)xMgCl2 and (PEO)xMgCl2·4H2O are shown to be amorphous, but in (PEO)xMgCl2·6H2O it is crystalline. Polar optical microscopy images indicate in each PEO/magnesium chloride system the crystalline morphology clearly changes with the increase of magnesium salt content. The reason for the formation of the spherulites with special morphology are the strong interaction between magnesium cation and ether oxygen of PEO, and the different evaporation rates of ethanol and chloroform in mixed solvent. A better understanding of the effects of hydration on polyelectrolyte crystallinity can help in improving their use in a variety of applications. © 2013 Wiley Periodicals, Inc. J Polym Sci Part B: Polym. Phys. 2013, 51, 1162-1174 [ABSTRACT FROM AUTHOR]

The resistance distance rij between vertices i and j of a connected (molecular) graph G is computed as the effective resistance between nodes i and j in the corresponding network constructed from G by replacing each edge of G with a unit resistor. The Kirchhoff index Kf(G) is the sum of resistance distances between all pairs of vertices. In this work, according to the decomposition theorem of Laplacian polynomial, we obtain that the Laplacian spectrum of linear hexagonal chain Ln consists of the Laplacian spectrum of path P2n+1 and eigenvalues of a symmetric tridiagonal matrix of order 2n + 1. By applying the relationship between roots and coefficients of the characteristic polynomial of the above matrix, explicit closed-form formula for Kirchhoff index of Ln is derived in terms of Laplacian spectrum. To our surprise, the Krichhoff index of Ln is approximately to one half of its Wiener index. Finally, we show that ${Kf(G)\over W(G)}>{1\over 5}$ holds for all graphs G in a class of graphs including Ln. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008 [ABSTRACT FROM AUTHOR]

The resistance distance rij between vertices i and j of a connected (molecular) graph G is computed as the effective resistance between nodes i and j in the corresponding network constructed from G by replacing each edge of G with a unit resistor. The Kirchhoff index Kf(G) is the sum of resistance distances between all pairs of vertices. In this work, closed-form formulae for Kirchhoff index and resistance distances of circulant graphs are derived in terms of Laplacian spectrum and eigenvectors. Special formulae are also given for four classes of circulant graphs (complete graphs, complete graphs minus a perfect matching, cycles, Möbius ladders Mp). In particular, the asymptotic behavior of Kf(Mp) as p → ∞ is obtained, that is, Kf(Mp) grows as 1/6p3 as p → ∞. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007 [ABSTRACT FROM AUTHOR]

Product development in the manufacturing industry has been facing unprecedented challenges brought about by ever-changing global and competitive market conditions as well as changing individual customer demands. As manufacturing enterprises become more specialized, they need to communicate and work concurrently on a large volume of product data covering their factories, sub-contractors as well as suppliers. The collaboration and cooperation between enterprises is changing from a supply chain based on material flow to a collaborative product development chain based on task flow. Computer network technologies, especially the Internet, have injected velocity into product development activities and enabled companies to shift their traditionally centralized product development philosophy to networked product development philosophy. This paper introduces a new paradigm called Internet-based collaborative product development chain (ICPDC) to answer the aforementioned needs of current product development. It connects users in geographically different locations to carry out product development activities simultaneously and collaboratively using a series of tools, including product management tools, workflow management tools, and project management tools. Some key aspects of the ICPDC, including its concept, collaboration mechanism, constituents and fashioning principle, are introduced in detail. Furthermore, a framework for the ICPDC based on a Brower/Server is proposed. Finally, a prototype is implemented using web services technology and .Net programming language to demonstrate the feasibility of the structure and the collaborative approach that has been developed. [ABSTRACT FROM AUTHOR]

[Display omitted] Graphene oxide (GO), for its unique structure with high biocompatibility and designability, is widely used in the antibacterial field. Various strategies have been designed to fabricate GO-based composites with antibacterial properties. This review summarized these strategies, divided them into three types and interpreted their antibacterial mechanisms: (i) "GO*/non-GO" type in which GO acts as the single antibacterial core, (ii) "GO*/non-GO*" type in which GO and non-GO components function synergistically as dual antibacterial cores, (iii) "GO/non-GO*" type in which non-GO acts as the single antibacterial core, while GO component plays a supportive, not a dominant role in antibiosis. Besides, the fields suiting their applications and factors influencing their antibacterial properties were analyzed. Finally, the limitations and prospects in the current researches were discussed. In summary, GO-based composites have revolutionized antibacterial strategies. This review may serve as a reference to inspire further research on GO-based antibacterial composites. [ABSTRACT FROM AUTHOR]

Minimizing variability in collection and processing of human blood samples for research remains a challenge. Delaying plasma or serum isolation after phlebotomy (processing delay) can cause perturbations of numerous analytes. Thus, a comprehensive understanding of how processing delay affects major endpoints used in human immunology research is necessary. Therefore, we studied how processing delay affects commonly measured cytokines and immune cell populations. We hypothesized that short-term time delays inherent to human research in serum and plasma processing impact commonly studied immunological analytes. Blood from healthy donors was subjected to processing delays commonly encountered in sample collection, and then assayed by 62-plex Luminex panel, 40-parameter mass cytometry panel, and 540,000 transcript expression microarray. Variance for immunological analytes was estimated using each individual's baseline as a control. In general, short-term processing delay led to small changes in plasma and serum cytokines (range − 10.8 to 43.5%), markers and frequencies of peripheral blood mononuclear cell phenotypes (range 0.19 to 3.54 fold), and whole blood gene expression (stable for > 20 K genes)—with several exceptions described herein. Importantly, we built an open-access web application allowing investigators to estimate the degree of variance expected from processing delay for measurements of interest based on the data reported here. [ABSTRACT FROM AUTHOR]

Let f be a binary word and n ≥ 1. Then the generalized Lucas cube Q n (f ↽ ) is the graph obtained from the n -cube Q n by removing all vertices that have a circulation containing f as a factor. Ilić, Klavžar and Rho solved the question for which f and n , Q n (f ↽ ) is an isometric subgraph of Q n for all binary words of length at most five. This question is further studied in this paper. For an isometric word f , sufficient and necessary conditions of Q n (f ↽ ) being an isometric subgraph of Q n are found, and two problems on generalized Lucas cubes are also listed. [ABSTRACT FROM AUTHOR]

• Correlation and regression analyses were conducted on nearly 33000 meteorological data and 14 urban physical indicators. • Maximum daytime temperature will increase by 0.91 °C for every 10% addition in building footprint ratio. • Daytime thermal environment and nighttime thermal environment are affected by different urban physical indicators. Recent trends in increasing global extreme weather patterns have led to a proliferation of studies about urban climate. However, most current studies have been conducted with insufficient urban climate and spatial data. Nearly 33,000 meteorological data were obtained from Foshan Meteorological Bureau to accurately identify whether and how urban spatial form affects urban thermal environment. Correlation and regression analyses were conducted on these meteorological data and 14 selected urban physical indicators, eight of which exhibited correlations with urban thermal environment. Unitary regression analysis showed that building footprint ratio is the most reliable predictor among the 14 urban physical indicators. The building footprint ratio explained about 70 % of the variance in daytime air temperature (AT) and urban heat island temperature (UHIT). According to the fitting equation, maximum daytime temperature, average daytime UHIT and average night UHIT will increase by 0.91 °C, 0.39 °C and 0.44 °C, respectively for every 10 % addition in building footprint ratio. Besides, the most surprising aspect of the regression analysis is that the daytime thermal environment and nighttime thermal environment are affected by different urban physical indicators. It can be seen from the results of unitary regression analysis that water area ratio has a strong correlation with daytime thermal environment, while impervious surface area ratio has a more obvious influence on night thermal environment. Multiple regression analysis revealed that the model composed of building footprint, green area, and water ratios explained about 83.3 % of the variance in average daytime UHIT. The model composed of building footprint, impervious surface area, and green area ratios explained about 80 % of the variance in average night UHIT. [ABSTRACT FROM AUTHOR]

• Temporal and spatial distribution characteristics of urban climate in Xi'an were assessed. • The assignment method was proposed for drawing single meteorological factor distribution map. • The divided climate zones were classified by applying the k-means clustering analysis in winter and summer. • A method of drawing the UC-Map based on the spatial statistical analysis of multivariate data was developed. • Multivariate data were converted into the urban planning management unit to facilitate the urban management work. Rapid urbanization have increased the sensitivity of urban environment to extreme weather. To improve the deteriorating urban environment, the current situation of urban climate should be evaluated systematically and applied to the planning process. This study reports on the temporal and spatial variability of urban climate and introduces a method for constructing an urban climate map based on spatial statistical analysis of field measurement data. Taking Xi'an, a metropolis in northern China, as the case study, we first conducted a 3-year meteorological investigation, including air temperature, relative humidity, and wind speed in both summer and winter. Meanwhile, five indicators with potential impacts on urban climate were selected to describe the urban characteristics. Then, the geographic information system was applied to integrate the meteorological data and urban characteristic data in order to assign more meteorological data. Next, three types of meteorological single-factor and thermal comfort spatial distribution maps were derived. The k-means clustering analysis method was then employed to classify three types of meteorological factors into seven zones in horizontal spatial dimension. Finally, urban climate maps were generated. This study can help planners quickly distinguish urban climate-sensitive and valuable zones in order to make better strategies for future development. [ABSTRACT FROM AUTHOR]

[Display omitted] • Rigid-rotor molecules are irradiated by THz pulses in resonance with molecular rotational transitions. • The phases of expansion coefficients in molecular rotational wave packet are independent of the amplitudes or durations of the pulses at some conditions. • The phase differences of expansion coefficients in molecular rotational wave packet are in linear relationships with the carrier envelope phases of pulses at some conditions. We found the phase differences of the expansion coefficients in rotational wave packet are in linear relationships with the phases of corresponding pulses when gas-phase linear molecules are irradiated by pulses in resonant with their rotational transitions. Using these relationships, we can accurately control the wave packet by first determine the phases of the controlling pulses, and then optimize the durations (or amplitudes) of the pulses to demanded population. We also compared the phase relationships obtained from ground and other initial rotational eigenstates and analyzed the reason for lowered orientation degree in non-zero temperature conditions. [ABSTRACT FROM AUTHOR]

• Economy of various vegetation-planting options are analyzed. • The improvement and cost of PET for different vegetation are analyzed quantitatively. • Continuous planting is the most effective layout to improve the thermal comfort. • We prove that dispersed planting of trees is the most economical layout for improving thermal comfort. Global climate change and urbanization have generated increased attention to thermal comfort in urban residential areas. The use of vegetation to improve thermal comfort has been confirmed by many previous studies. However, in actual construction projects, we not only need to know the positive benefits of different greening patterns on outdoor thermal comfort but we also need to consider the cost. In this paper, the main research intent is to analyze the economics of the improvement of outdoor thermal comfort through different greening patterns to provide a theoretical basis for the selection of efficient greening patterns for actual construction projects. All vegetation species, include tree, shrub and ground-cover plant, could reduce the PET difference for whole daytime. To reduce the PET mean value by 1°C, the expenses of tree is 1/31.2 to 1/320.7 of the ground-cover plants or 1/2.9 to 1/18.2 of shrubs. We propose that trees should be planted in areas where improving outdoor thermal comfort is necessary. The dispersed planting of trees can make the improvement of outdoor thermal comfort more economical. Ground-cover plants and shrubs could be planted on a large scale in areas that have a low demand for outdoor thermal comfort. [ABSTRACT FROM AUTHOR]

The blade is a key component of aero engines. In traditional blade electrochemical machining (ECM) processes, the electrolyte is simultaneously supplied to the concave and convex parts. To improve flow field uniformity at marginal areas of the blade, a new blade flow mode with an independent electrolyte supply at the leading and trailing edges is proposed here. Flow field simulations of the entire blade ECM process are carried out. The results show that in comparison with conventional flow field modes, electrolyte distribution in this new flow field mode is more uniform and the change in velocity is smaller along the flow path. In addition, the size and pressure of the liquid inlets at the leading and trailing edges were optimized, with optimal height and pressure values of 3 mm and 0.9 MPa determined, respectively. The results of experimental investigations proved that the new flow mode proposed here was reasonable, and the surface roughness and contour accuracy of the leading and trailing edges were significantly enhanced. [ABSTRACT FROM AUTHOR]

Palmitoylation plays an important role in modulating protein trafficking, stability, and activity. The major predicament in protein palmitoylation study is the lack of specific and sensitive tools to visualize protein-specific palmitoylation. Although FRET approach was explored by metabolically labeled palmitic acid and antibody recognized target protein. The trans -membrane strategy suffers from low FRET efficiency due to the donor and acceptor located at different sides of membrane. Herein, we proposed a cis -membrane multi–fluorescence resonance energy transfer (multi–FRET) for amplified visualization of specific palmitoylated proteins through metabolic labeling and targeted recognition. The azido-palmitic acid (azido-PA) was metabolically incorporated into cellular palmitoylated proteins, followed by reacting with dibenzylcylooctyne-modified Cy5 (DBCO-Cy5) through copper-free click chemistry. The protein probe was attached to targeted protein by specific peptide recognition, which initiates a hybridization chain reaction (HCR) amplification process. The cis -membrane labeling method enables effective intramolecular donor-acceptor distance and allow to increase FRET efficiency. Simultaneously, HCR amplification triggered multi–FRET phenomenon with significantly improved FRET efficiency. With the superiority, this strategy has achieved the enhanced FRET imaging of palmitoylated PD-L1 and visualizing the palmitoylation changes of on PD-L1 under drug treatment. Furthermore, the established method successfully amplified visualization of PD-L1 palmitoylation in vivo and mice tumor slice. We envision the approach would provide a useful platform to investigate the effects of palmitoylation on the protein structure and function. [Display omitted] • We proposed a cis -membrane multi-FRET for amplified visualization of specific palmitoylated proteins. • HCR amplification triggered multi–FRET phenomenon with significantly improved FRET efficiency. • The cis -membrane multi-FRET strategy successfully amplified visualization of PD-L1 palmitoylation in vivo. [ABSTRACT FROM AUTHOR]

By numerically solving the time-dependent Schrödinger equation, we study high-order harmonic generation from the asymmetric diatomic molecule HeH2+ in a corotating two-color circularly polarized laser field. Our results reveal a strong correlation between the molecule orientation and the harmonic yield. The harmonics in the plateau region can achieve an intensity modulation of one to two orders of magnitude with the change in the orientation angle. Through the time-dependent evolution of ionized electron wave packets combined with the analysis of the transition dipole moment between the continuum and bound states, the modulation of the harmonic strength may be attributed to the difference in the recollision angle of ionized electron wave packets relative to the molecules. In addition, the harmonic ellipticity is also affected by the molecular orientation. Notably, we found that the harmonic with greater ellipticity and higher intensity can be obtained with an orientation angle of 147°. These findings open up new avenues for achieving enhanced efficiency, the near-circular polarization of harmonics, and precise control over harmonic polarization states. [ABSTRACT FROM AUTHOR]

A simple, sensitive and portable biosensor for the detection of DNA based on the nanogold-functionalized poly(amidoamine) (PAMAM) dendrime composites and personal glucose meters (PGMs) was developed. In the presence of the target DNA, strand displacement reaction occurred between signal DNA and the target, inducing the release of invertase-DNA nanogold-functionalized PAMAM (IM-Au-PAMAM) from DNA-functionalized magnetic beads. The free IM-Au-PAMAM after magnetic separation finally acted as a highly efficient signal amplifier to catalyze the hydrolysis of sucrose into glucose for the readout of PGMs. The PGM signal intensity versus logarithm of DNA level was linear in the range from 0.5 pM to 1 nM. The detection limit for the target DNA sequence was 0.26 pM with good selectivity. Moreover, the new biosensor showed the advantages of cost-effectiveness, simplicity, portability, and convenience, and could be expected to be an emerging alternative for point-of-use detection of non-glucose targets. [ABSTRACT FROM AUTHOR]

In this work, we propose a hairpin probe-mediated exponential amplification reaction (HEAR) strategy that combines DNA strand displacement with a "who triggers, who gets generated" mode, providing excellent single-base discrimination and a reduced background signal. The detection limit is 19 aM, which is reduced by 3 orders of magnitude compared to traditional exponential amplification approaches. This one-pot strategy also exhibits a wide dynamic range, high specificity and short detection time. It is expected to become a powerful tool for clinical diagnosis. [ABSTRACT FROM AUTHOR]

The detailed characteristics of the harmonics emission of atoms driven via a linearly polarized laser field combined with an orthogonal, weaker electrostatic field were investigated by numerically solving the time-dependent Schrödinger equation. It was found that the direction of the laser polarization and the polarization of the attosecond light, which is synthesized from the harmonic, can be controlled by the amplitude of the electrostatic field. With the analysis of the spatial distribution of the time-dependent dipole moment and the time-dependent evolution of the electronic wave packet, the control mechanism for the harmonic characters was investigated. The generation of harmonics in the vertical direction of the laser electric field is caused by the breaking of the symmetry of the time wave packet distribution. With this mechanism, we obtained circularly polarized attosecond light. [ABSTRACT FROM AUTHOR]

Based on the strong field approximation theory and numerical solution of Maxwell's propagation equations, the high–order harmonic is generated from a neon (Ne) atom irradiated by a high–intensity laser pulse whose central wavelength is 800 nm. In the harmonic spectrum, it is found that in addition to the odd harmonics of the driving laser, a new frequency peak appeared. By examining the time–dependent behavior of the driving laser, it is found that the symmetry of the laser field is broken. We demonstrated that these new spectrum peaks are caused by the intensity reduction and frequency blue shift of the high–intensity laser during propagation. Our results reveal that it is feasible to modulate the harmonics of the specific energy to produce high–intensity harmonic emission by changing the gas density and the position of the gas medium interacting with the laser pulse. [ABSTRACT FROM AUTHOR]

High-order harmonic generation of atoms irradiated by an ultrashort laser pulse was calculated by numerically solving the time-dependent Schrödinger equation and the Bohmian trajectory scheme. The harmonic spectra with the two schemes are quantitatively consistent. Using the wavelet behavior of the Bohmian trajectory, the spatio-temporal features of harmonic emission from different energy regions are analyzed. It is found that the spatio-temporal distribution of the harmonic well revealed the physical mechanism of harmonic generation. This method will contribute to the understanding of harmonic emission mechanisms in complex systems, which include many atoms. [ABSTRACT FROM AUTHOR]

By using the numerical solution of the time-dependent Schrödinger equation, we theoretically explored the high-order harmonic generation process under the interaction of high-intensity two-color ultrashort driving laser pulses with atoms. The symmetry of the electric field of the laser pulse will be broken. The producing electric field was controlled at the subcycle level by an IR laser and its second harmonic, which has the unique characteristic that two sequential half-cycles become distinct, rather than merely opposite in sign. Compared with the case of the atom in the fundamental laser pulse, the harmonic efficiency showed an increase of 1∼2 orders of magnitude at specific harmonic order with this combined pulse action. Through the theoretical analysis with the "three-step model", it was demonstrated that the enhancement of the harmonic intensity is due to the fast ionization of electrons at the ionization moment and the short time from ionization to recombination of ionized electrons. In addition, effects of the peak field amplitude ratio, the full width at half maximum, the phase delay of the two-color pulses, the laser intensity and ionization probability on the harmonic efficiency enhancement were also investigated. [ABSTRACT FROM AUTHOR]

BACKGROUND: Implant-restored patients with periodontitis have a higher risk of developing peri-implantitis, and helping them develop oral cleaning habits is significant. OBJECTIVE: To evaluate the effectiveness of motivational interviewing based on the transtheoretical model on the modification of oral cleaning behaviors of implant-restored patients with periodontitis. METHODS: Patients with periodontitis (n = 70) who would receive dental implant treatment were included. And they were randomly divided into two groups: experimental (n = 35) and control (n = 35). Control patients received routine oral hygiene education, and those in the experimental group received motivational interviewing based on the transtheoretical model. Oral cleaning behavior was compared between the two groups before and after intervention. In addition, periodontal health status was compared on the day of implant restoration and three months later. RESULTS: Compared to the control, the experimental group demonstrated significantly better oral hygiene behavior after intervention (P < 0.05). Three months after implant restoration, significantly better results were obtained by the experimental group in terms of mPLI and mSBI (P < 0.05). CONCLUSION: Motivational interviewing based on the transtheoretical model can effectively improve the oral cleaning behavior and periodontal health of implant-restored patients with periodontitis. [ABSTRACT FROM AUTHOR]

BACKGROUND: Sinus floor elevation and immediate dental implantation are commonly performed to treat dentition defects in elderly patients. Targeted cognitive behavioral interventions (CBI) during the perioperative period can reduce pain and anxiety as well as improve sleep quality. This can lead to improvements in patient cooperation during follow-up treatment and enhance the overall efficacy of the surgery. OBJECTIVE: The study aimed to investigate the impact of a cognitive behavioral intervention method on perioperative pain, anxiety, and sleep quality in elderly patients undergoing sinus floor elevation and immediate dental implantation. METHODS: Forty patients who required the treatment at the Stomatology Clinic in our hospital between December 2018 and December 2022 were enrolled in this randomized controlled trial. The patients were randomly divided into two groups: a control group (n = 20), which received conventional treatment and care during the perioperative period, and an intervention group (n = 20), which received comprehensive behavioral intervention in addition to the conventional treatment and care during the perioperative period. The perioperative anxiety, pain, and sleep quality of the patients in both groups were evaluated. Anxiety was assessed using the Self-Rating Anxiety Scale (SAS), sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI), and pain was measured using the visual analog scale (VAS). RESULTS: No statistically significant differences in SAS and PSQI were observed between the two groups at the initial visit; the values were significantly higher than those measured postoperatively. The SAS scores and PSQI of patients on days 0 and 7 post-surgery in the intervention group were significantly lower than those in the control group (P < 0.05). CONCLUSION: Perioperative cognitive behavioral intervention can effectively improve anxiety, postoperative pain and sleep quality in elderly patients who have undergone sinus floor elevation and immediate dental implantation, thereby reducing the incidence of complications. [ABSTRACT FROM AUTHOR]

Glycosylated PD-L1 is a more reliable biomarker for immune checkpoint therapy and plays important roles in tumor immunity. Glycosylation of PD-L1 hinders antibody-based detection, which is partially responsible for the inconsistency between PD-L1 immunohistochemical results and therapeutic treatment response. Herein, we present a proximity ligation assay mediated rolling circle amplification (PLA-RCA) strategy for amplified imaging of glycosylated PD-L1 in situ. The strategy relies on a pair of DNA probes: an aptamer probe to specifically recognize cellular surface protein PD-L1 and a glycan conversion (GC) probe for metabolic glycan labeling. Upon proximity ligation of sequence binding to the two probes, the proximity ligation–triggered RCA occurs. The feasibility of the as-proposed strategy has been validated as it realized the visualization of PD-L1 glycosylation in different cancer cells and the monitoring of the variation of PD-L1 glycosylation during drug treatment. Thus, we envision the present work offers a useful alternative to track protein-specific glycosylation and potentially advances the investigation of the dynamic glycan state associated with the disease process. [ABSTRACT FROM AUTHOR]

An enzyme-free sandwich-type electrochemical biosensor was developed for highly sensitive detection of CTCs by fabricating a novel PdRu/Pt hierarchical structures through a facile hydrothermal method and coupling with hemin/G-quadruplex as signal amplification probes. Meanwhile, high conductive Super P and gold nanoparticles (AuNPs) acted as sensing medium to improve electrical conductivity and immobilization of anti-EpCAM antibody to specifically capture model CTCs. [Display omitted] • 3D hyperbranched PdRu/Pt heterostructures with excellent catalytic activity was synthesized to improve signal amplification. • PdRu/Pt integrated with hemin/G-quadruplex DNAzyme was first utilized as signal probe. • As-proposed biosensor reached a detection limit down to 2 cells mL−1. Metastasis due to circulating tumor cells (CTCs) shed from the original tumor accounts for the majority of cancer-related death. Efficient CTCs detection is pivotal to the diagnosis of early cancer metastasis. In this work, Platinum nanoparticles (PtNPs) decorated hyperbranched PdRu nanospines (PdRu/Pt) hierarchical structures were firstly synthesized to detect CTCs with the assistance of DNAzyme. Meanwhile, Super P and gold nanoparticles (AuNPs) acted as sensing medium to improve electrical conductivity and immobilization of anti-EpCAM antibody to specifically capture model CTCs. After immune-conjugation of anti-EpCAM-MCF-7-signal probes on the gold electrode, PtNPs, PdRu nanospines (PdRuNSs) and hemin/G-quadruplex co-catalyzed substrate H 2 O 2 to realize multiplexed signal amplification, which significantly improves the analytical performance of the electrochemical biosensor. As-proposed biosensor reached a limit of detection (LOD) down to 2 cells mL−1 and showed a wide detection range of 2 to 106 cells mL−1. Application of the biosensor to detect MCF-7 cells spiked human blood samples further demonstrated the feasibility for early cancer evaluation in clinic. [ABSTRACT FROM AUTHOR]

The emergence of DNA nanotechnology has enabled the systematic design of diverse bionic dissipative behaviors under the precise control of nucleic acid nanodevices. Nevertheless, when compared to the dissipation observed in robust living systems, it is highly desirable to enhance the anti-interference for artificial DNA dissipation to withstand perturbations and facilitate repairs within the complex biological environments. In this study, we introduce strategically designed "trash cans" to facilitate kinetic control over interferences, transforming the stochastic binding of individual components within a homogeneous solution into a competitive binding process. This approach effectively eliminates incorrect binding and the accumulation of systemic interferences while ensuring a consistent pattern of energy fluctuation from response to silence. Remarkably, even in the presence of numerous interferences differing by only one base, we successfully achieve complete system reset through multiple cycles, effectively restoring the energy level to a minimum. The system was able to operate stably without any adverse effect under conditions of irregular interference, high-abundance interference, and even multiplex interferences including DNA and RNA crosstalk. This work not only provides an effective paradigm for constructing robust DNA dissipation systems but also greatly broadens the potential of DNA dissipation for applications in high-precision molecular recognition and complex biological reaction networks. [Display omitted] • By eliminating cumulative errors we built an anti-interference DNA dissipation system first time. • Affinity trash bring the dissipation network closer to living organisms to multiple complex stimuli. • Be able to stably work in high abundance, irregular, multiple interference, and RNA and DNA crosstalk. [ABSTRACT FROM AUTHOR]

A fluorometric assay was introduced to determine Acinetobacter baumannii (A. baumannii) in blood samples by utilizing Zr-MOFs both as functional coating for magnetic Fe3O4 nanoparticles to provide modification surface (Zr-mMOF) and as fluorescein carrier to produce fluorescence signals (F@UIO-66-NH2). Through strong Zr-O-P bonding, two distinct terminal phosphate-labeled A. baumannii and lipopolysaccharide (LPS) specific aptamers were attached onto Zr-MOFs to fabricate the magnetic core-shell capture probe (denoted as Zr-mMOF-p-Ab-Apt) and signal probe (denoted as F@UIO-66-NH2-p-LPS-Apt), respectively. After successive incubation with A. baumannii in blood samples and magnetic separation, the sandwich-type composite of capture probe/A. baumannii cells/signal probe was treated with high concentration of anionic phosphate ions to destroy the nano-structure of UIO-66-NH2 in the signal probe and fast release of fluorescein to produce amplified fluorescence signals. Due to the high aptamer modification efficiency of Zr-mMOF-p-Ab-Apt (up to 93%) and its strong affinity to A. baumannii, the enrichment efficiency of this capture probe has reached to 96.7%. Further, due to the high fluorescein loading efficiency of UIO-66-NH2 and our novel amplification strategy to destroy F@UIO-66-NH2-p-LPS-Apt to release and amplify fluorescein signals at 512 nm in the presence of high concentration of anionic phosphate ions, the sensitivity of this method has reached 10 cfu mL−1. This method allows enrichment and determination of A. baumannii within ~2.5 h. The limit of detection of A. baumannii in blood samples is 10 cfu mL−1 with a linear range of 101–105 cfu mL−1. This indicates the potential of this assay for diagnosis of bloodstream infection in early stage. [ABSTRACT FROM AUTHOR]

• Rapid analysis for long-range multi-site haplotypes was developed. • Thermodynamically designed LNA-button probes combine high specificity and yield. • Rapidly determine whether SNP sites apart > 1000 bp are located on the same DNA strand. • Rapid analysis of all haplotype combinations of two DNA strands. • Modularized algorithm proposed is highly scalable for different setting and platform. Some combinations of statistically related SNPs (tag SNPs) distributed within individual chromosomes may reflect richer medical and genetic information than isolated SNPs, called haplotypes. However, unlike the rapidly growing number of rapid SNP tests, determining whether SNP loci separated thousands of bases are located on the same chromosome is so difficult and time-consuming that its personalized application in clinical settings is slow. First, we designed special targets that retain modularized haplotype information; through DNA nanotechnology, we developed Holliday-junction button probes that specifically identify much longer double-stranded targets; through exploration of thermodynamic mechanisms, we overcame the paradox of probe specificity and yield to significantly improve detection; through mathematical logic reasoning, we designed modular algorithms to simplify difficult long-range multilocus haplotype analysis. The multidisciplinary intersection allows us to quickly and accurately read known haplotypes. Most importantly, haplotype analysis based on mathematical logic is universally applicable, and other effective molecular biological techniques can be combined with our algorithm to obtain more professional results. This study provides a new perspective on the field's efforts to solve the thorny problem of haplotype analysis. It is promising to contribute to the development of personalized applications of haplotype analysis. [ABSTRACT FROM AUTHOR]

N6-methyladenosine (m6A), one of the most abundant RNA methylation which is ubiquitous in eukaryotic RNA, plays vital roles in many biological progresses. Therefore, the rapid and accurate quantitative detection of m6A is particularly important for its functional research. Herein, a label-free and highly selective electrochemical immunosensor was developed for the detection of m6A. The method is established on that the anti-m6A-Ab can recognize both m6A-RNA and m6A-DNA. An analogous modified DNA probe (L1) serves as a signal molecule, by competing with m6A-RNA for binding to Abs to broaden the linear range. The detection of m6A-RNA by this method is unaffected by the lengths and base sequences of RNA. Under optimal conditions, the proposed immunosensor presented a wide linear range from 0.05 to 200 nM with a detection limit as low as 0.016 nM (S/N = 3). The specificity and reproducibility of the method are satisfactory. Furthermore, the developed immunosensor was validated for m6A determination in human cell lines. Thus, the immunosensor provides a promising platform for m6A-RNA detection with simplicity, high specificity and sensitivity. [ABSTRACT FROM AUTHOR]

The precise identification of rare single nucleotide variations (SNVs) concomitant with excess wild-type DNA is a valuable method for minimally invasive disease diagnosis and early prediction of drug responsiveness. Selective enrichment of mutant variants via strand displacement reaction offers an ideal approach of SNVs analysis but fails to differentiate wildtype from mutants with variant allele fraction (VAF) < 0.01%. Here, we demonstrate that integration of PAM-less CRISPR-Cas12a and adjacent mutation-enhanced inhibition of wild-type alleles enables highly sensitive measurement of SNVs well below the 0.01% VAF threshold. Raising the reaction temperature to the upper limit of LbaCas12a helps to boost PAM-less activation of collateral DNase activity, which can be further enhanced using PCR additives, leading to ideal discriminative performance for single point mutations. Along with selective inhibitors bearing additional adjacent mutation, it allowed detection of model EGFR L858R mutants down to 0.001% with high sensitivity and specificity. Preliminary investigation on adulterated genomic samples prepared in two different ways also suggests that it can accurately measure ultralow-abundance SNVs extracted directly from clinical samples. We believe that our design, which combines the superior SNV enrichment capability of strand displacement reaction and unparalleled programmability of CRISPR-Cas12a, has the potential to significantly advance current SNV profiling technologies. [Display omitted] • Temperature enhanced PAM-less activation of CRISPR-Cas12a shows higher specificity toward single point mutation. • PAM-less Cas12a and allele-specific enrichment enable ultrasensitive post-PCR measurement of model SNVs below 0.001% VAFs. • Analysis of genomic samples and series-diluted clinical samples demonstrate the feasibility to detect SNVs of VAFs < 0.01%. [ABSTRACT FROM AUTHOR]

We experimentally investigate gas pressure-dependent effect on the high harmonic generation (HHG) of Ar and N 2 gases in a tight focusing regime with near IR ultrafast laser fields. Different from a loose-focusing condition, the measured data show a shift of the pressure regime for phase matching towards to the lower pressure side with the increasing driven laser intensity. By comparing the results with a theoretical calculation based on the Constant’ one-dimensional model, we illustrate that this pressure dependence stems from the Gaussian beam phase gradient and atomic dipole phase which can become the key factors for phase matching in the tight focusing regime, interested in a high-repetition-rate coherent extreme-ultraviolet generation. [ABSTRACT FROM AUTHOR]

Circulating tumor cells (CTCs) are promising liquid biopsy biomarkers for early cancer detection and anti-cancer therapy evaluation. The ultra-low abundance of CTCs in blood samples requires highly sensitive and accurate detection ways. In this study, we propose the design of a dual-recognition electrochemical biosensor to improve both the specificity and signal response. PdPtCuRu mesoporous nanospheres (PdPtCuRu MNSs) with excellent three dimensions (3D) nanopore structures were synthesized by one-pot method and connected to mucin 1 (MUC1) aptamer to serve as signal amplification probe. Besides, superconductive carbon black, Ketjen Black (KB), and gold nanoparticles (AuNPs) modified organometallic frame (CeMOF-Au) were combined to work as signal transducer. The characteristic branching structure of KB provides abundant contact points to load CeMOF-Au to heighten the interface electron transfer rate. In addition, AuNPs were reduced on the surface of CeMOF, which could effectively bind the capture antibody and further enhance the conductivity. Under the optimized condition, the limit of detection (LOD) of the as-constructed biosensor was less than 10 cells mL−1 for model A549 cells, and showed good specificity and accuracy in spiked serum samples. We envision the as-proposed electrochemical biosensor would alternate as a useful tool for the clinical detection of CTCs for cancer diagnosis. Scheme. (A) The synthesis procedure of PdPtCuRu MNSs. (B) Construction of the sandwich-type electrochemical biosensor. [Display omitted] • 3D PdPtCuRu mesoporous nanospheres with excellent catalytic activity was first synthesized to improve signal amplification. • Ketjen Black integrated with CeMOF-Au was utilized as electrochemical responsive substrate for the first time. • As-proposed dual-recognition biosensor reached a detection limit less than 10 cells mL−1 of A549. [ABSTRACT FROM AUTHOR]

We present a high-resolution and delay-stabilized setup for attosecond spectroscopy based on high-order harmonic generation from the intense laser passing through a differential gas cell. It shows the ability to generate the tunable photons from VUV to Soft X-ray (20–180 eV) at low backing pressure of target gas. This atto-beamline consists of an HHG source, electron and XUV spectrometers, and an active stabilization system. The measurements show it can be stabilized to sub-20 as in hours, together with a home-built XUV spectrometer with an energy resolution better than E / Δ E ≥ 1200 in the wavelength range of 5–25 nm. We demonstrated its applications for producing the narrowband XUV source, extending the cutoff energy of HHG, and performing RABBITT measurements, particularly for investigating the excitation and ionization dynamics of atoms and molecules in a broad energy range by measuring the electrons and photons with attosecond temporal resolution. [Display omitted] • We designed and built a stable attosecond beamline based on strong laser-driven high-harmonic generation from a home-built differential gas cell. • Attosecond pulse trains with a 280 as duration has been produced and reconstructed from RABBITT scanning, tunable attosecond XUV pulse with energy from 20 to 180 eV are characterized. • High energy resolution electron and XUV spectrometers are built and characterized for the study of ultrafast atomic and molecular dynamics. [ABSTRACT FROM AUTHOR]

Nucleic acid nanotechnologies based on toehold-mediated strand displacement are ideally suited for single-nucleotide variations (SNVs) detection. But only a limited number of means could be used to construct selective hybridization probes via finely designed toehold and regulation of branching migration. Herein, we present a cooperative hybridization strategy relying on a dual-toehold and bulge-loop (DT&BL) probe, coupled with the strand displacement catalytic (SDC) cycle to identify SNVs. The dual-toehold can simultaneously hybridize the 5′ and 3′ ends of the target, so that it possessed the mutual correction function for improving the specificity in comparison with the single target-binding domain. Insertion of BLs into the dual-toehold probe allows tuning of Gibbs free energy change (ΔG) and control of the reaction rate during branching migration. Using the SDC cycle, the reactivity and selectivity of the DT&BL probe were increased drastically without elaborate competitive sequences. The feasibilities of this platform were demonstrated by the identification of three cancer-related genes. Moreover, the applicability of this biosensor to detect clinical samples showed satisfactory accuracy and reliability. We envision it would offer a new perspective for the construction of highly specific probes based on dynamic DNA nanotechnology, and serves as a promising tool for clinical diagnostics. [ABSTRACT FROM AUTHOR]

Pseudomonas aeruginosa (P. aeruginosa) is one of the most common bacteria in nosocomial infection. Here, a novel fluorescence biosensor based on double-stranded DNA branch migration-induced hybridization chain reaction (HCR) and DNAzyme feedback circuit was constructed for sensitive detection of P. aeruginosa. The binding of P. aeruginosa with its aptamer on a DNA three-way junction structure initiated the double-stranded DNA branch migration to form two DNA "Y" junction structures. One DNA "Y" junction structure opened the fluorescence-labelled DNA hairpins and triggered the HCR. The other DNA "Y" junction structure formed a double-stranded DNAzyme and cleaved the specific ribonucleotide site, producing new triggering probes to start the next cycle of the double-stranded DNA branch migration. Ultimately, a large number of DNA "Y" junction structures were produced, which greatly promoted signal amplification. Under optimized conditions, the proposed biosensor detected a wide linearity range of 102–107 CFU mL−1, and the limit of detection was 37 CFU mL−1 (S/N = 3). The recovery test results indicated that the biosensor has promising clinical application potential. Because of the simultaneous initiation of the HCR and the DNAzyme feedback circuit through the double-stranded DNA branch migration, the constructed biosensor provided an ideal platform for pathogenic bacteria detection without protein enzymes and complex signal amplification procedures. [Display omitted] • Double-stranded DNA branch migration was firstly applied to bacterial biosensing. • Both HCR and DNAzyme feedback circuit were contributed to amplify the signal. • Protein enzymes and complex signal amplification procedures are not required. • The biosensor exhibits high sensitivity and specificity for detecting P. aeruginosa. [ABSTRACT FROM AUTHOR]

Aconitum georgei Comber is a China-specific Aconitum (Ranunculaceae) plant. In the present study, eighteen compounds, including fourteen diterpenoid alkaloids (1 – 14) and four nonalkaloidal constituents (15 – 18) were isolated from the roots of A. georgei. Among them, fifteen compounds (1 – 11 and 14 – 18) have not previously been found in this species, and 3-methoxymethylbenzoate (17) has not previously been isolated from the Aconitum genus. The chemotaxonomic value of these compounds was explored through network analysis. The results showed that some of these compounds such as falconeridine (6) and 14-anisoyl- N -deethylaconine (10) showed limited distribution in the genus, which could help to narrow species identification to A. georgei where other phenotypic characters are limited. • Eighteen compounds were isolated from Aconitum georgei. • Fifteen compounds were isolated in A. georgei for the first time. • 3-methoxymethylbenzoate has not previously been isolated from genus Aconitum. • Compound-species network analysis exhibited their chemotaxonomic value. [ABSTRACT FROM AUTHOR]

Precise detection of low-frequency gene mutations surrounded by excess wild-type DNA is important in many aspects of medical fields. Most hybridization-based methods for high-resolution mutant allele analysis are hindered by competition of the complementary strand with single-strand probes for the target strand. Here, we demonstrate that site-specific insertion of endonuclease recognition sites into amplicons allows post-PCR generation of short dsDNA or ssDNA, whereby improves the sensitivity of both melting temperature analysis (MTA) and end-point detection following up. Using a three-staged PCR protocol, enrichment of target gene and incorporation of specific restriction sites in amplicons were ensued with hardly any loss in amplification efficiency and specificity. It enables simultaneous discrimination among a panel of totally 11 EGFR 19 exon deletion mutations via MTA after post-PCR digestion by either FokI only or cooperated with CRISPR-Cas12a, using SYBR green I. By replacement of one double-strand cleavage site with a nickase binding domain post-PCR generation of ssDNA of interest via strand displacement amplification (termed as iSDA) is realized. Our preliminary investigation shows that iSDA permits analysis of single nucleotide variants down to 0.1% allelic-frequency using end-point detection. Given the good compatibility with the majority of mutant-enrich PCR methods, we envision it would advance the current gene profiling technologies to a large extent. [ABSTRACT FROM AUTHOR]

Sensitive and specific detection of single nucleotide variants (SNVs) has great potential for disease diagnosis and prognosis. Hybridization probes based on DNA strand displacement have shown high SNV discrimination and programmability. However, it remains a challenge to balance the specificity and sensitivity of hybridization reactions due to the limited adjustability of probe sequences. Herein, we inserted bulge-loops in probes to fine-tune the thermodynamic changes of the entropy-driven catalytic reaction (EDC), significantly improving the selectivity (the DF of CAC>CGC mutation was promoted from 17.66832 ± 2.25913–72.54 ± 8.21) and responsiveness of SNV identification. In addition, oligonucleotides with chromophores (Tags) were used to impart microspheres with different fluorescence characteristics, to construct a set of convenient and flexible barcodes. Coupled with the bulge-loops tuned EDC probes and the Tag-encoded barcodes, the designed biosensor achieved higher specificity (DF=194.86 ± 62.11) and lower signal leakage. Most importantly, it allowed simultaneous detection of low-abundance five-plexed EGFR mutations in the same system. This work provided insights into a rational design of DNA cascade reaction networks and advanced the construction of customizable multiplexed detection systems in the suspension array technology. • We insert bulge-loops into EDC probes to achieve superior specificity while maintaining satisfactory yield. • We propose a flexible and stable suspension array composed of ten optical barcodes. • As-proposed probes with barcodes reaches a detection limit of down to 0.05% CAC > CGC mutation. • Constructed Multiplexed detection system simultaneously detected five 1% EGFR mutations from 1 femtomolar gene sample. [ABSTRACT FROM AUTHOR]

[Display omitted] • The ionization yield of the initial momenta L = −1 is an order of magnitude higher than that of L = 1 for the Ar atom. • The angular distribution at the single ionization instants play a key role in the recollision progress. • The recollision times of the different initial angular momenta are mapped to the electron momentum spectrum. The non-sequential double ionization process of Ar atoms with different initial angular momenta in the 500 nm circularly polarized field is investigated with a classical ensemble model. The numerical results show that, under the circularly polarized laser pulse, the double ionization yield as a function of the laser intensity for Ar atoms with different initial angular momenta exhibit an obvious Knee structure. The ionization yield in the counter-rotating case where the electronic initial rotation direction is opposite to the vector potential of the laser field, significantly higher than that in the co-rotating case where the electronic initial rotation direction is consistent with the vector potential of the laser field. Based on the classical trajectory analysis, it is found that this ionization difference comes from the angle between the direction of the electronic momentum and the force of the laser field at the single ionization instant. The angle in the counter-rotating case is greater than that in the co-rotating case, and the counter-rotating electrons are more likely to return to the parent ion for recollision. Besides, the recollision intants of Ar atoms with the different initial angular momenta are mapped to the electron momentum spectrum. This may provide a method to obtain the electron's recollision instant of Ar atoms with different initial angular momenta. [ABSTRACT FROM AUTHOR]

Nucleic acid hybridization plays a critical role in medical diagnostics and nanotechnology, but its selectivity and robustness remain to be improved. Here, focusing on double-stranded nucleic acid-based hybridization, we present a series of related strategies. Above all, two simple strategies for enriching toehold-included double-stranded nucleic acids have been proposed. On this basis, two universal hybridization methods with higher selectivity than typical toehold exchange reaction and a long target detection method using short probes to extend the detectable length range are realized. We also provide a double-stranded nucleic acids-catalyzed cycle amplification reaction to improve sensitivity, which has superior interference resistance and excellent discrimination for single-base mismatches. Besides, double-stranded nucleic acids with forked toeholds are used as essential elements to construct a series of logic gates that can evaluate different input combinations. Given the unique advantages of double-stranded nucleic acids, we expect the current work to advance the application of double-stranded nucleic acid-based hybridization in medical diagnostics and nanotechnology. [Display omitted] • Two methods for enriching double-stranded nucleic acids that possess toeholds. • Two universal hybridization methods and a long targets detection method were provided. • A double-stranded nucleic acids-catalyzed cycle amplification reaction for improving sensitivity. • Double-stranded nucleic acids for robust logic computation. [ABSTRACT FROM AUTHOR]

Abstract: BaMgAl10O17:Eu2+(BAM) phosphor particles were prepared by sol–gel processes. The effect of the firing temperature and the Eu2+ concentration on the distribution of Eu2+ among different sites was firstly investigated through the changes of excitation spectra with changing firing temperature and Eu2+ concentration. The mechanism underlying was elucidated. The stability of BAM could be improved by increasing the firing temperature and Eu2+ concentration. [Copyright &y& Elsevier]

N6-methyladenosine (m6A) is the most abundant post-transcriptional modification in RNA and has important implications in physiological processes and tumor development. However, sensitive and specific quantification of locus-specific m6A modification levels remains a challenging task. In the present work, a novel m6A-sensitive DNAzyme was utilized to directly detect m6A by coupling with a three-way junction-mediated isothermal exponential CRISPR amplification reaction for the first time. This method was built on the fact that the binding arm of the DNAzyme bound to the specific site and its core structure catalyzed the selective cleavage of unmodified adenine instead of methylated adenines. Subsequently, the intact RNA was identified by the proximity effect of the three-way junction. Enormous amounts of single-stranded DNA products were generated through a combination of SDA and EXPAR for signal amplification. The specific real-time curve of products was recorded through detecting the fluorescence intensity triggered by CRISPR Cas12a. As a result, methylation target of abundance down to 1% was successfully identified. In addition, this strategy could be used for the analysis of cell RNA extracts. Combined with an electrochemical sensor for quantitative detection of RNA methylation, we demonstrated the generality of as-proposed strategy. We envision the present method would provide a new platform for the analysis of m6A in RNA and promote its application in clinical diseases. • DNAzyme and the three-way junction were firstly used to specifically identify m6A RNA. • The integration of EXPAR and CRISPR Cas12a assisted exponential amplification realized sensitive detection of m6A modifications down to 1% abundance. • This strategy was easily elaborated into multiple reactions for different detection purposes. [ABSTRACT FROM AUTHOR]

• Established a rapid multiplexing method for simultaneous detection of multidrug-resistant genes in Acinetobacter baumannii. • CRISPR-Cas12a detection following PCR counterweighs the quantification discrepancy originated from primer dimer formation. • Combination of multiplex PCR and CRISPR-Cas12a enhance the detection limit of single gene target. Bacterial identification and phenotypic antibiotic susceptibility test (p-AST) limit timely anti-infection treatment of patients in clinic to a large extent. Here, we develop a rapid platform integrated multiplex PCR with CRISPR-Cas array to detect multidrug-resistant Acinetobacter baumannii (MDRAB). The platform relies on multiplex PCR amplification strategy which can simultaneously amplify the house-keeping gene and 4 β-lactamase genes of Acinetobacter baumannii (A. baumannii), accompanying with the indiscriminate single-stranded DNase activity of LbaCas12a to generate a single fluorescent signal for multiplex PCR products. The genotypic antibiotic susceptibility test (g-AST) of A. baumannii was completed within 2 h, with a detection limit down to 50 CFU/mL. In addition, we also proved the specificity to differentiate primer dimers. These findings jointly demonstrate the ultimate potential of the CRISPR-Cas12a method for multiple genes detection with high throughput and high specificity. Given the versatility and universality of CRISPR-Cas12a platform, it is expected that this research will further promote its application in the diagnosis and treatment of multidrug-resistant bacteria. [ABSTRACT FROM AUTHOR]

High-order harmonic generation is investigated by using time-dependent density functional theory to numerically simulate the interaction of the benzene molecule with a few-cycle circularly polarized laser pulse. Compared with the harmonics from atoms and diatomic molecules with similar ionization energy irradiated by the same laser pulse, the harmonics from benzene molecules possess higher efficiency and cut-off energy. Further research reveals that the harmonic efficiency and cut-off energy of the benzene molecule increase gradually as the wavelength of the driving laser decreases. Through the analysis of the time-dependent evolution of electronic wave packets, it is found that the harmonic generation can be attributed to the recombination of the ionized electrons and their parent ions. By optimizing the driving laser pulse, we demonstrated that high-order harmonic generation in the benzene molecule can be used to produce isolated circularly polarized attosecond pulse. [ABSTRACT FROM AUTHOR]

• The electron momentum "correlation behavior" cause by the sequential double ionization in the high-intensity linearly polarized laser field. • This correlation behavior is caused by the ultrafast electronic ionization within a quarter optical period of the laser field. The double ionization of a hydrogen molecule in a high-intensity linearly polarized laser pulse is systematically investigated. It is found that the process of the double ionization of the hydrogen molecules is dominated by the sequential double ionization, whereas the spectrum of the electron momentum exhibits an obvious correlation behavior of electrons and this correlation behavior exists with the variation of the nuclear distance. Based on the analysis of electron trajectories, we demonstrate that this correlation is caused by the ultrafast electronic ionization within a quarter optical period of the laser field. Especially, the correlation of the electron momenta depends on the laser pulse's negative vector potential, which is corresponding to the ionization instants of the two electrons. [ABSTRACT FROM AUTHOR]