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Daptomycin is a last-line antibiotic used in the treatment of multidrug-resistant Enterococcus faecium infections. Alarmingly, daptomycin-resistant E. faecium isolates have emerged. In this study, we investigated the evolution and mechanisms of daptomycin resistance in clinical E. faecium isolates and the corresponding acquisition of collateral sensitivity (CS) as an evolutionary trade-off. We evolved daptomycin resistance in six daptomycin-susceptible E. faecium isolates to obtain daptomycin-resistant mutants. The six E. faecium strains successfully acquired high-level resistance to daptomycin in vitro, but this led to fitness costs in terms of growth, in vitro competition, and virulence. Mutations in liaFSR, yycFG, and cls; increased surface positive charge; thicker cell walls; and elevated expression of dltABCD and tagGH were observed in daptomycin-resistant mutants. Surprisingly, we observed the emergence of CS in SC1762 isolates after the induction of daptomycin resistance. Compared with parental strains, the SC1174-D strain (i.e., daptomycin-resistant mutant of SC1174; non-CS) showed significantly upregulated expression of the vanA gene cluster. However, in SC1762-D (i.e., daptomycin-resistant mutant of SC1762), all vanA cluster genes except the vanX gene were obviously downregulated. Further in silico analyses revealed that an IS1216E-based composite transposon was generated in SC1762-D, and it disrupted the vanH gene, likely affecting the structure and expression of the vanA gene cluster and resulting in resensitization to glycopeptides. Overall, this study reports a novel form of CS between daptomycin and glycopeptides in E. faecium. Further, it provides a valuable foundation for developing effective regimens and sequential combinations of daptomycin and glycopeptides against E. faecium.

The generalised Pareto distribution is an efficient model to characterise the high-resolution sea clutter. Robust and precise estimation of the model's parameters is a precondition of effective target detection in sea clutter. It is known that the explicit bipercentile (BiP) estimators are efficient in computation and robust to outliers. In this study, it is proved that the explicit BiP estimators are also consistent with respect to sample size. In practical applications, only limited samples are available and the bias of the BiP estimators degrades the estimation precision. The properties of the biases are analysed and BiP estimators of bias reduction are constructed by the look-up table method. The BiP estimators of bias reduction are verified by simulated data and measured sea clutter data.

BACKGROUND The data of nasal anthropometric measurements could help surgeons perform preoperative or postoperative assessments and decide surgical strategies of the nose plastic surgery and related cosmetic rhinoplasty. The aim of the study was to describe the average values of the nasal anthropometric measurements in Han Nationality young female population in Central China. METHODS All 430 Han Chinese young females were obtained for this study, and their anthropometric features were measured including weight, height, 11 items of linear distance and 4 angles. Seven proportion indices of the soft tissue of the external nose were determined. Related results were compared with the result of other available literature about nasal anthropometry in Han Nationality young females from different regions of China and the other racial/ethnic nasal anthropometry in the world populations. RESULTS The means of the linear measurements of the external nose in this study were as follows: nasal height (48.9 mm), nasal bridge length (43.3 mm), morphological facial height (110.4 mm), facial width (125.1 mm), intercanthal width (35.9 mm), nasal tip protrusion (21.1 mm), nasal width (35.5 mm), nasal ala length (27.9 mm), nasal ala thickness (4.1 mm), columella height (8.9 mm), columella width (6.0 mm). The means of the angular measurements of the nose were as follows: nasofrontal angle (143.3 degree), nasofacial angle (34.1 degree), nasal tip angle (80.4 degree), nasolabial angle (97.3 degree). CONCLUSIONS There were regional differences of the external nasal anthropometric of the Han Nationality young female adults in China and the racial/ethnic differences of that compared with the some races/ethnic around the world. This study could provide credible and objective reference material for plastic and maxillofacial surgeons for the external nasal soft tissue evaluation and planning of the cosmetic nasal surgery in the Han Nationality young female adults in Central China.

Cutaneous wound healing has always been an intractable medical problem for both clinicians and researchers, with an urgent need for more efficacious methods to achieve optimal outcomes morphologically and functionally. Stem cells, the body’s rapid response ‘road repair crew,’ being on standby to combat tissue injuries, are an essential part of regenerative medicine. Currently, the use of adipose-derived stem cells (ADSCs), a kind of mesenchymal stem cells with multipotent differentiation and self-renewal capacity, is surging in the field of cutaneous wound healing. ADSCs may exert influences either by releasing paracrine signalling factors or differentiating into mature adipose cells to provide the ‘building blocks’ for engineered tissue. As an important paracrine substance released from ADSCs, exosomes are a kind of extracellular vesicles and carrying various bioactive molecules mediating adjacent or distant intercellular communication. Previous studies have indicated that ADSCs derived exosomes (ADSCs-Exos) promoted skin wound healing by affecting all stages of wound healing, including regulating inflammatory response, promoting proliferation and migration of fibroblasts or keratinocytes, facilitating angiogenesis, and regulating remodeling of extracellular matrix, which have provided new opportunities for understanding how ADSCs- Exos mediate intercellular communication in pathological processes of the skin and therapeutic strategies for cutaneous wound repair. In this review, we focus on elucidating the role of ADSCs-Exos at various stages of cutaneous wound healing, detailing the latest developments, and presenting some challenges necessary to be addressed in this field, with the expectation of providing a new perspective on how to best utilize this powerful cell-free therapy in the future. (Ann Dermatol 33(4) 309∼317, 2021)

With heterogeneous traffic agents moving at unprotected phase, severe crossing conflicts are witnessed at mixed-flow intersections, especially when left-turning vehicles are confronted with motorcycles. However, for modelling vehicle turning behaviour, potential conflicts involving diagonal-crossing motorcycles are seldom investigated in existing studies. To explore these scenes, we present a novel interaction-aware deep-learning framework. Firstly, a Long Short-Term Memory (LSTM) based network is employed to encode vehicle historical motion features. Secondly, each vehicle’s potential target lanes are identified with a probabilistic method, followed by a pooling module that extracts and summarizes intention features. Thirdly, Graph Attention Network (GAT) and a synthesized network are introduced to model vehicle-vehicle interaction and vehicle-motorcycle interaction respectively. Finally, multiple kinds of obtained features are sent to a LSTM based decoder module, where both future displacement and body orientation of vehicles are predicted. In short-time simulation experiments, average displacement error is reduced by 47.7% and 20.0% compared to baseline and state-of-the-art methods, with ablation studies conducted to quantify the efficacy of each kind of feature. Moreover, regarding recursive simulation, our model shows availability of reproducing lane-selecting and motorcycle-evasive behaviours. Distributions of post-encroachment time further indicate that the proposed framework can serve as a promising method to realize reliable motion planning for autonomous vehicles.

Large-scene sea clutter exhibits spatially-varying power and non-Gaussianity due to varying grazing angle and sea state, which leads to the lack of data with consistent statistical property, called spatially small-sample (SSS) problem. Therefore, compound-Gaussian model with spatially-varying texture is introduced to characterize large-scene sea clutter. However, existing methods of sea clutter parameter estimation, including moment-based, maximum likelihood and explicit bipercentile estimators, lose their estimation efficiencies with the SSS problem. In this study, a multiscan recursive Bayesian (MRSB) method is proposed to deal with the estimation problem of spatially-varying sea clutter parameters. This method is constructed by transforming scanning data in frames to the prior information of parameters in order to cover the shortage of sample number. The MRSB method not only improves the parameter estimation property of spatially-varying sea clutter due to the performance assessment with clutter data, but also starts a new mode of radar, that is, radar remembers all information and no data.

In this article, the relationship between the mechanical properties of wood–plastic composite (WPC) parts fabricated by selective laser sintering (SLS) and the laser intensity is determined. Green parts were formed from WPC by SLS process, the SLS green parts had sufficient strengths for features to be built with relatively high dimensional accuracy. In order to improve the mechanical properties of the parts to better level, the post-processing – infiltration with wax – is used. Experiments for studying mechanical properties of WPC parts with laser intensity growing are carried on, the result is as following: because interfacial adhesion of copolyester and densification are improved with laser intensity growing, impact strength increased gradually either in green part style or in wax-infiltrated part style, tensile strength and bending strength of wax-infiltrated parts increased gradually. The tensile strength improved 191% and the bending strength improved 17%, with the increase in laser intensity from 226 Watt/mm2 to 311 Watt/mm2; the impact strength of green parts improved 543% and the impact strength of wax-infiltrated parts improved 147%, respectively, by increasing the laser intensity from 226 Watt/mm2 to 340 Watt/mm2. But when the laser intensity is greater than 311 Watt/mm2, the tensile strength and bending strength decreased for further increasing of the laser intensity, leading to higher temperature, making the melt viscosity of the copolyester drop.

The development of electrochemical micromachining (EMM) was influenced greatly by the technology of pulses generator. In order to solve the problems of EMM, it was an effective method to use nanosecond pulses voltage in EMM. Therefore, a nanosecond pulses voltage was prepared firstly. Its minimum pulse duration is 5 ns, and its voltage, current, and duty ratio can be changed freely. Then the microelectrode of tungsten filament was fabricated in sodium hydroxide electrolyte. The cylindrical microelectrode was less than 30μm in diameter, 50 in ratio of length and diameter. It was used to fabricate micro structure by EMM milling layer by layer. The little gap can be realized by adjusting machine parameters, the process can be carried out by short circuit detected, and a fine micro structure also can be realized finally. The application of the nanosecond pulses voltage can make EMM a further development.