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A kind of launching platform driven by two permanent magnet synchronous motors which is used to launch kinetic load to hit the target always faces strong parameter uncertainties and strong external disturbance such as the air current impulsion which would degrade their tracking accuracy greatly. In this paper, a practical method which combines adaptive robust control with neural network-based disturbance observer is proposed for high-accuracy motion control of the launching platform. The proposed controller not only accounts for the parametric uncertainties but also takes the external disturbances into account. Adaptive control is designed to compensate the former, while neural network-based disturbance observer is designed to compensate the latter respectively and both of them are integrated together via a feedforward cancellation technique. A new kind of parametric adaptation and weight adaptation strategy is designed by using the linear combination of the system's tracking error and the weight estimation error as a driving signal for parametric adaptation and disturbance approximation. The stability of the novel control scheme is analyzed via a Lyapunov method and this method presents a prescribed output tracking performance in the presence of both parameter uncertainties and unmodeled nonlinearities. Extensive comparative simulation and experimental results are obtained to verify the high-performance of the proposed control strategy. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Purpose: The oncogenic roles of sphingosine kinase 1 (SphK1) in various cancers, including thyroid cancer, have been well demonstrated. However, the microRNAs (miRNAs) associated with the oncogenic roles of SphK1 remain largely unknown. Methods: Global gene and miRNA expression in TPC1-Vector and TPC1-SphK1 cells was analyzed using digital gene expression (DGE) analysis and small RNA-seq, respectively. miRNA-mRNA interactions were explored by microT-CDS, and the predicted networks were visualized using CytoScape. Cell invasion and migration were assessed by performing Transwell invasion and wound-healing assays. Luciferase reporter and immunoblot assays were used to evaluate the targeting of fibronectin 1 (FN1) by miR-144-3p. Results: In this study, we found that overexpression of SphK1 differentially regulates the expression of 46 miRNAs and 506 mRNAs in papillary thyroid cancer (PTC) TPC1 cells. Combining bioinformatics predictions of mRNA targets with DGE data on mRNA expression allowed us to identify the mRNA targets of deregulated miRNAs. The direct interaction between miR-144-3p and FN1, which mediates the pro-invasive role of SphK1 in PTC cells, was experimentally validated. Conclusions: Our results demonstrated that SphK1 overexpression drives a regulatory network governing miRNA and mRNA expression in PTC cells. We also demonstrated the roles played by miR-144-3p and FN1 in mediating the oncogenic function of SphK1, which enhanced the understanding of the etiology of PTC. [ABSTRACT FROM AUTHOR]

Cellulose acetate (CA) membranes have been widely used as food packaging materials as well as reverse osmosis systems. This study presents the manufacturing of composite CA film with antibacterial properties which is essential for CA film applications in the industry. N-Halamine precursor of polymethacrylamide-modified nano-crystalline cellulose particles (NCC-PMAMs) were prepared and incorporated into CA film. The composite films with intercalated structure were formed via a solvent-casting technique. After chlorination, the composite film CA/NCC-PMAM-Cl-1.0 with 1.82 × 1016 atoms/cm2 covalently bonded chlorine showed excellent antibacterial properties by inactivating 6.04 logs of Staphylococcus aureus and 6.27 logs of Escherichia coli within 10 and 5 min, respectively. According to X-ray diffraction spectra, NCC-PMAMs behaved as a facilitator for film crystallization. The mechanical strength of the composite film also increased compared with that of pure CA film. However, the composite film became brittle and the maximum decomposition temperature decreased slightly. Preliminary data of in vitro cytocompatibility evaluation indicate that the film is not toxic and has potential use in food packaging. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Braided and biodegradable polyglycolide suture was antibacterially functionalised with N-halamines via layer-by-layer assembly technique. Multilayers of chitosan (polycation) and poly-sodium-p-styrenesulfonate (polyanion) were successfully coated via electrostatic assembly, followed by top layer of chitosan on polyglycolide suture. Upon chlorination of coated suture with dilute sodium hypochlorite solution, the amino groups of chitosan were transformed into N-halamine structures. The transformation was assessed by iodometric/thiosulfate titration, Fourier transform infrared spectroscopy and differential scanning calorimeter analysis. The surface morphology of coated suture was observed by scanning electron microscope and atomic force microscope. Chlorine loading, antibacterial efficacy and tensile strength of chlorinated sutures treated with two different molecular weights of chitosan were compared and evaluated. A general trend of linear increase in chlorine loadings of sutures with the increase in number of layers and solution concentration was found. The chlorinated suture with high molecular weight chitosan coating completely inactivated both Escherichia coli O157:H7 and Staphylococcus aureus bacteria within 15 min of contact time. The 3T3 mouse fibroblasts in vitro cell cytocompatibility studies demonstrated that antibacterial sutures have fairly good biocompatibility. [ABSTRACT FROM AUTHOR]

ABSTRACT In this study, new cationic homopolymer and anionic copolymer were synthesized, and deposited onto polyglycolide sutures using a layer-by-layer assembly technique. The coated sutures were rendered antibacterial by chlorinating with dilute solution of household bleach solution at pH 7. The chlorination treatment transformed the NH groups of anionic copolymer into N-halamine structures. The N-halamine-modified sutures were challenged with Staphylococcus aureus and Escherichia coli O157:H7 bacteria at different contact times. The suture with chlorine loading of 0.22% completely inactivated both bacterial strains in 30 min contact time. Fourier transform infrared spectroscopy, scanning electron microscopy, and analytical titration confirmed the successful deposition of the N-halamine multilayers. The effect of layer-by-layer coatings of polyelectrolytes on the chlorine loading and antibacterial efficacy of sutures was evaluated. The straight-pull and knot-pull strength tests performed on the sutures reported slight decline in tensile properties after chlorination treatment. The in vitro hemolysis and cytocompatibility tests revealed that the N-halamines-based antibacterial sutures were biocompatible. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42483. [ABSTRACT FROM AUTHOR]

The vacuum-based magnetron sputtering was utilized to the fabrication of CuZnSnS (CZTS) thin films on flexible Al, Mo, and stainless steel foil substrates. The structural, compositional, and morphological properties of prepared thin films were investigated. According to the XRD and Raman results, for Al and Mo foil substrates, the structures of thin films are major CZTS and tiny secondary phase of CuSnS. The preferred orientation of CZTS is along the (112) plane. The XRD peaks and Raman peaks of CZTS on Mo foil substrate are stronger than those on Al foil substrate. The calculated grain sizes are 33.6 and 39.0 nm for the thin films on Al and Mo foil substrates, respectively, indicating the higher crystallinity for Mo foil substrate samples. The compositions of thin films are near the stoichiometry of CZTS and show Cu-poor and Zn-rich properties. The surfaces of thin films are composed of compact grains. When using stainless steel foil as substrate, the fabricated thin films are composed of CuSnS, FeS, and Zn, revealing the existence of sulfurization of Fe. The reaction between Fe and S inhibits the full sulfurization of Cu-Zn-Sn precursor, resulting in the absence of CZTS in the fabricated thin films. The composition of thin films is far from the stoichiometry of CZTS. In order to get desired properties of CZTS thin films, the inhibition of reaction between Fe and S is needed for stainless steel foil substrate. [ABSTRACT FROM AUTHOR]

A general and efficient palladium-catalyzed direct C3 alkenylation of 4H-pyrido[1,2-a]pyrimidin-4-ones using AgOAc/O2 as the oxidant has been developed. A variety of 4H-pyrido[1,2-a]pyrimidin-4-ones were successfully coupled with acrylate esters, styrenes, methylvinylketone, and acrylamide in moderate to excellent yields. The reaction exhibited complete regio- and stereoselectivity. This transformation provides an attractive new approach to functionalize 4H-pyrido[1,2-a]pyrimidin-4-ones. [ABSTRACT FROM AUTHOR]

Natural bone apatite crystals, which mediate the development and regulate the load-bearing function of bone, have recently been associated with strongly bound citrate molecules. However, such understanding has not been translated into bone biomaterial design and osteoblast cell culture. In this work, we have developed a new class of biodegradable, mechanically strong, and biocompatible citrate-based polymer blends (CBPBs), which offer enhanced hydroxyapatite binding to produce more biomimetic composites (CBPBHAs) for orthopedic applications. CBPBHAs consist of the newly developed osteoconductive citrate-presenting biodegradable polymers, crosslinked urethane-doped polyester and poly (octanediol citrate), which can be composited with up to 65 wt % hydroxyapatite. CBPBHA networks produced materials with a compressive strength of 116.23 ± 5.37 MPa comparable to human cortical bone (100-230 MPa), and increased C2C12 osterix gene and alkaline phosphatase gene expression in vitro. The promising results above prompted an investigation on the role of citrate supplementation in culture medium for osteoblast culture, which showed that exogenous citrate supplemented into media accelerated the in vitro phenotype progression of MG-63 osteoblasts. After 6 weeks of implantation in a rabbit lateral femoral condyle defect model, CBPBHA composites elicited minimal fibrous tissue encapsulation and were well integrated with the surrounding bone tissues. The development of citrate-presenting CBPBHA biomaterials and preliminary studies revealing the effects of free exogenous citrate on osteoblast culture shows the potential of citrate biomaterials to bridge the gap in orthopedic biomaterial design and osteoblast cell culture in that the role of citrate molecules has previously been overlooked. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 2521-2532, 2014. [ABSTRACT FROM AUTHOR]

Objective The purpose of this study is to assess the height and width of mandibular cross-sections and the thickness of cortical bone for young females in different vertical skeletal pattern by cone beam CT (CBCT) and determine the characteristics and differences of mandible among different vertical skeletal patterns. Methods A total of 64 females, aged from 19 to 40 years old, were enrolled from Department of Orthodontics of School of Stomatology of Shandong University. After examination with CBCT scan, they were divided into 3 groups according to the vertical skeletal patterns(14 in low-angle group, 31 in average-angle group and 19 in high-angle group). The mandibular mor-phology was evaluated according to the height and width of the mandibular cross-sections and the thickness of cortices. SPSS 16.0 was used to analyze the characteristics and differences of mandible among different vertical skeletal patterns. Results The height of symphysis in the high-angle group was higher than that in the low-angle group, but the height of molars in the low-angle group was higher than that in the high-angle group (P<0.05). In the regions of anterior teeth and premolars, the width of upper one third of the mandibular cross-sections in the low-angle group was significantly larger than those in the high-angle group, while in the symphysis and lateral incisors regions, the width of lower one third of the mandibular cross-sections in the low-angle group was larger than those in the high-angle group (P<0.05). Except of the region of premolars, the cortical thickness of base in the low-angle group was significant thicker than those in the high-angle group (P<0.05>). In the regions of canine, premolar and molar, the cortical thickness of buccal upper one third in the low-group was thicker than those in the high-angle group, but in the regions of canine and the second molar, the cortical thickness of buccal lower one third in the low-angle groups was thicker than those in the high-angle group (P<0.05). In the regions of the symphysis, the cortical thickness of lingual lower one third in the low-angle group was thicker than those in the high-angle group (P<0.05), but in the regions of premolar and molar of lingual upper one third in the low-angle group was thicker than those in the high-angle group (P<0.05). Conclusion The height and width of the cross-sections of the body of mandible differed more than thickness of cortical bone among the three different vertical skeletal patterns. The height of cross-sections decreases gradually from the an-terior region to the posterior region in three groups. The width of cross-sections in the low-group is thicker than those in other two groups. The thickness of cortical bones decreases successively from low, average to high angle group. [ABSTRACT FROM AUTHOR]

Nanofibrous poly( [ABSTRACT FROM AUTHOR]

CuZrAlM (M = Ce, Pr, Tb, and Gd) bulk metallic glassy (BMG) alloys were prepared by copper-mold vacuum suction casting. The effects of rare-earth elements on the glass-forming ability (GFA), thermal stability, and mechanical properties of CuZrAlM were investigated. The GFA of CuZrAlM (M = Ce, Pr) alloys is dependent on the content of Ce and Pr, and the optimal content is 4 at.%. CuZrAlTb ( x = 2, 4, and 5) amorphous alloys with a diameter of 5 mm can be prepared. The GFA of CuZrAlGd ( x = 2, 4, and 5) increases with increasing Gd. T and T of all decrease. T is dependent on the rare-earth element and its content. Δ T for most of these alloys decreases except the CuZrAlGd alloy. The activation energies Δ E, Δ E, and Δ E for the CuZrAlGd BMG alloy with Kissinger equations are 340.7, 211.3, and 211.3 kJ/mol, respectively. These values with Ozawa equations are 334.8, 210.3, and 210.3 kJ/mol, respectively. The CuZrAlTb alloy presents the highest microhardness, Hv 590, while the CuZrAlPr alloy presents the least, Hv 479. The compressive strength ( σ) of the CuZrAlGd BMG alloy is higher than that of the CuZrAlTb BMG alloy. [ABSTRACT FROM AUTHOR]

The article examines the controlled delivery of tetracycline hydrochloride (TC) and chlorotetracycline hydrochloride (CTC) from electrospun poly(D,L-lactide) (PDLLA) nanofibers. The influence of methanol as a cosolvent in the eletrospinning solution in regard to physical fiber properties and drug release behavior is discussed. The study shows that with increasing amounts of methanol, fiber diameters decreases and contact angle and drug-loading efficiency increases.

Generally, bulk metallic glasses (BMGs) exhibit a very limited plastic deformation under a compression load at room temperature, often less than 2% before fracturing. In this letter, through an appropriate choice of BMGs' composition, an amorphous rod of ZrM64.80Cu14.85Ni10.35Al10 with a diameter of 2 mm was prepared by using copper mold suction casting. X-ray diffraction and differential scanning calorimetry were utilized to determine its structure and thermal stability, and the uniaxial compression test was adopted to study its plastic deformation behavior at room temperature simultaneously. The results showed that the glass transition temperature and onset temperature of the exothermic reaction of the amorphous rod were 646 and 750 K, respectively, and its micro-hardness was 594.7 Hv. During compression, when the engineering strain and engineering stress arrived at 9.05% and 1732 MPa, respectively, i.e., the true strain and true stress reached 9.42% and 1560 MPa, respectively, the amorphous rod started to yield. After yielding, with the increase of load, the strain increased and the glass rod ultimately were compressed into flake-like form. Although the maximum engineering strain was larger than 70%, i.e., the maximum true strain exceeded by 120%, the amorphous specimen was not fractured, indicating that it has super-plasticity at room temperature. Through the appropriate choice of composition and optimization of the technological process, flexible BMG with super-plasticity at room temperature could be produced. [ABSTRACT FROM AUTHOR]

Engaging children in describing real-life scenes provides an effective approach to fostering language production and developing their language skills, enabling them to establish meaningful connections between their language proficiency and authentic contexts. However, for such learning tasks, there has been a lack of research focusing on promoting self-directed language learning by using artificial intelligence techniques, primarily due to the challenges of handling multimodal information involved in such tasks. To address this gap, this study introduced a two-stage automated evaluation method that employed emerging cross-modal matching AI techniques. Firstly, an automated scoring model was developed to evaluate the quality of students' responses to scene description tasks. Compared with manually assigned human scores, our model scored students' descriptions accurately, as evidenced by a small testing mean absolute error of 0.3969 for a total score of 10 points. Based on the scoring results, immediate feedback was then provided to students by generating targeted comments and suggestions. The goal of this feedback was to assist students in progressively improving their descriptions of daily-life scenes, thereby enabling them to practice their language skills independently. To assess the effectiveness of the feedback, a comprehensive investigation was conducted involving 157 students from middle schools in China, and both qualitative and quantitative experimental data were collected from the students. It is found that the quality of students' descriptions was improved significantly with the assistance of immediate feedback. On average, students achieved an increase of 1.48 points in their scores after making revisions based on the feedback. In addition, students reported positive learning experiences and expressed favorable opinions regarding the language learning tasks with the automated evaluation. The findings of this study have significant implications for future research and educational practice. They not only highlighted the potential of emerging cross-modal matching AI techniques in automatically evaluating learning tasks involving multimodal data but also suggested that providing immediate targeted feedback based on automated scoring results can effectively promote students' self-directed language learning. • Generating descriptions from real-life visuals enhances authentic language learning. • Feasible to provide automated feedback in self-directed language learning using AI. • Automated feedback motivates students to improve and engage in language learning. [ABSTRACT FROM AUTHOR]

This study investigates the economic resilience of cities in Hubei province during the COVID-19 pandemic, utilizing highway nighttime lights as a proxy indicator. By February 2020, the pandemic had caused a significant economic contraction in Hubei. However, by May 2021, a strong recovery was observed, with most cities experiencing growth rates of over 20%. Despite initially similar responses to the crisis, this study reveals significant heterogeneity in economic resilience across the examined cities in Hubei. The spatial distribution follows a core-periphery structure, with Wuhan exhibiting greater resistance to economic shocks compared to peripheral cities. Furthermore, the response capacity within the Wuhan urban agglomeration area exhibits regional variations. In summary, lockdown policies had spatially varied impacts on economic resilience across Hubei's cities. These results offer valuable insights into regional economic resilience and contribute to the formulation of strategies aimed at effectively addressing future unforeseen events. [ABSTRACT FROM AUTHOR]

Corn oil as a nanofluid base fluid has the problem of easy oxidation, and the addition of tertiary butyl-hydroquinone is expected to improve the antioxidant property of corn oil. In this paper, a new environmentally friendly nanofluid was prepared by using corn oil as a base fluid, A12O3 as nanoparticles, and tertiary butylhydroquinone as an antioxidant to study its settlement stability and antioxidant properties. The content of oxidation products and viscosity of the nanofluids at different times were investigated from the perspectives of particle size, particle mass fraction, antioxidant type, and antioxidant addition. The results showed that the nanofluids produced without surfactant, 100 mL of corn oil, Al2O3 nanoparticles with a particle size of 20 nm and a particle mass fraction of 1.1083% had the best sedimentation stability. The nanofluid with 0.7% of tertiary butylhydroquinone added had the optimum antioxidant properties. There are two phenolic hydroxyl groups in the molecule of tertiary butylhydroquinone, and each of the two phenolic hydroxyl groups provides one hydrogen ion, which forms stable quinone compounds in corn oil, making the oxidation rate of the corn oil slower. When the content of tertiary butylhydroquinone was added at less than 0.4%, the content of tertiary butylhydroquinone was not enough to effectively retard the oxidation reaction of the oil. When the addition of tertiary butylhydroquinone exceeded 0.7%, the antioxidant property of the nanofluid could only be improved slightly, and the oxidation induction time increased slowly, but on the contrary, the viscosity of the nanofluid would be increased greatly. The nanofluid prepared in this paper has the characteristics of environmental friendly and good antioxidant performance, which can effectively slow down the generation of oxidised substances. This study contributes to the further development of antioxidant research of environmentally friendly nanofluids. [ABSTRACT FROM AUTHOR]

Background: In recent years, significant progress has been made in developing highly complex tissue-engineered skin substitutes (TESSs) for wound healing. However, the lack of skin appendages, such as hair follicles and sweat glands, and the time required, are two major limitations that hinder its broad application in the clinic. Therefore, it is necessary to develop a competent TESS in a short time to meet the needs for clinical applications. Methods: Adult scalp dermal progenitor cells and epidermal stem cells together with type I collagen as a scaffold material were used to reconstitute bilayer TESSs in vitro. TESSs at 4 different culture times (5, 9, 14, and 21 days) were collected and then grafted onto full-thickness wounds created in the dorsal skin of athymic nude/nude mice. The skin specimens formed from grafted TESSs were collected 4 and 8 weeks later and then evaluated for their structure, cell organization, differentiation status, vascularization, and formation of appendages by histological analysis, immunohistochemistry, and immunofluorescent staining. Results: Early-stage bilayer TESSs after transplantation had a better efficiency of grafting. A normal structure of stratified epidermis containing multiple differentiated layers of keratinocytes was formed in all grafts from both early-stage and late-stage TESSs, but higher levels of the proliferation marker Ki-67 and the epidermal progenitor marker p63 were found in the epidermis formed from early-stage TESSs. Interestingly, the transplantation of early-stage TESSs produced a thicker dermis that contained more vimentin- and CD31-positive cells, and importantly, hair follicle formation was only observed in the skin grafted from early-stage TESSs. Finally, early-stage TESSs expressed high levels of p63 but had low expression levels of genes involved in the activation of the apoptotic pathway compared to the late-stage TESSs in vitro. Conclusions: Early-stage bilayer TESSs reconstituted from skin progenitor cells contained more competent cells with less activation of the apoptotic pathway and produced a better skin structure, including hair follicles associated with sebaceous glands, after transplantation, which should potentially provide better wound healing when applied in the clinic in the future. [ABSTRACT FROM AUTHOR]

• A small-signal sequence impedance model of the island power system is built by harmonic linearization method. It is found that the output sequence impedance of the source PWM inverter in the system is not affected by the stable operating point. • Based on the impedance model, the influence of load type and load power on the stability of the island power system is analyzed. The essential reason of the high-frequency oscillation is that the capacitive output impedance of the source PWM inverter does not match the inductive output impedance of the load PWM rectifier at high-frequency areas. • An impedance reconstruction control for the source PWM inverter is proposed, which improves the phase of the output sequence impedance of the source PWM inverter at high-frequency areas to effectively suppress the high-frequency oscillation of the island power system. In island power system with strong mutual interaction of power electronic devices, stability problems such as high-frequency oscillation are prone to occur. Firstly, a small-signal sequence impedance model of an island power system is built by harmonic linearization method. It is found that the output sequence impedance of the source PWM inverter in the system is not affected by the stable operating point, but the input sequence impedance of the load PWM rectifier will decrease with the increase of power. Then, based on the sequence impedance model and Nyquist stability criterion, the influence of load type and load power on stability of the island power system is analyzed, which can reveal that high-frequency oscillation occurs when the source PWM inverter interacts with the load PWM rectifier. The essential reason of the high-frequency oscillation is that the capacitive output impedance of the source PWM inverter does not match the inductive output impedance of the load PWM rectifier at high-frequency areas. Aiming at this issue, an impedance reconstruction control for the source PWM inverter is proposed, which improves the phase of the output sequence impedance of the source PWM inverter at high-frequency areas to effectively suppress the high-frequency oscillation of the system. Finally, experiment results verify the correctness of analysis and effectiveness of the proposed control strategy. [ABSTRACT FROM AUTHOR]

• A small-signal model of the grid-connected system of SSVSI is established. The model fully considers the power coupling phenomenon in the system and provides a basis for in-depth analysis of the system characteristics. • The effects of grid equivalent resistance and SSVSI control parameters on the system are comprehensively analyzed. The effects of power coupling on the stable region of control parameters are quantitatively analyzed. In addition, the contradiction between SFR suppression and power coupling is analyzed when the virtual resistance is introduced. • An SFR suppression method based on band-stop filters is proposed. The proposed method effectively suppresses the resonance peaks without changing the original control parameters of the system, and improves the power response speed of the system. In addition, the proposed method avoids exacerbating the power coupling of the system compared to the virtual resistance method. Self-synchronizing voltage source inverter (SSVSI) can effectively improve grid frequency stability. However, the synchronous frequency resonance (SFR) inevitably exists in SSVSI. In this paper, a small-signal model considering power coupling is established to analyze the system characteristics. It is found that the control parameter adjustment and the virtual resistance method can suppress the SFR. However, the control parameter adjustment will change the dynamic and steady-state characteristics of the system, and the virtual resistance method will exacerbate the power coupling of the system. For this reason, based on the idea of eliminating the resonance peaks, this paper proposes an SFR suppression method based on band-stop filters. By connecting band-stop filters in series in the active power control loop (APCL) and the reactive power control loop (RPCL), the proposed method effectively suppresses the resonance peaks without changing the original control parameters of the system, and the control bandwidth is wider, which improves the power response speed of the system. In addition, the proposed method avoids exacerbating the power coupling of the system compared with the virtual resistance method. Finally, the simulation and experimental results verify the correctness of the theoretical analysis and the effectiveness of the control method. [ABSTRACT FROM AUTHOR]

• The effect of the internal power-sharing ratio of WTGs on the admittance characteristics of wind farms is investigated. • The identification method of the AOP-admittance model considering frequency-coupling for wind farms is proposed. • This method can identify the AOP-admittance model of wind farms by measurement data of WTGs under several operating points. • The identification method can avoid the dimension disaster in admittance modeling for the wind farm. Admittance identification is an effective tool to solve the issue of black-box admittance modeling in wind farms. However, due to the large operating range of wind farms, it is difficult to accurately identify the admittance model of wind farms under all operating conditions, which limits the research on wideband oscillation caused by the interaction between wind farms and the power grid. This paper analyses the characteristics of the frequency-coupling admittance for wind farms. It is found that the power-sharing ratio of wind turbine generators (WTGs) affects the admittance characteristic of the wind farm, which leads to a huge number of operating points for the wind farm. The all-operating-point (AOP) admittance model of wind farms considering frequency-coupling characteristics is hard to directly identify. Aiming for this problem, this paper proposes to first identify the AOP-admittance model for WTGs. Then, based on the operating points of each WTG and the network structure, the AOP-admittance model of the wind farm is obtained via the admittance aggregation and model reduction method. This proposed method solves the problem of black-box admittance modeling and addresses the problem of dimension disaster in admittance modeling for wind farms. The identified model of the wind farm can be used to accurately assess the stability of the wind power integration system under various operating conditions. Finally, the effectiveness of the proposed method is verified through the admittance measurement and stability analysis of the wind farm. [ABSTRACT FROM AUTHOR]

Hostile environmental cues cause Mycobacterium tuberculosis to enter a state of slow growth for survival. However, the underlying regulatory mechanism remains unclear. DnaA is essential for DNA replication initiation and represents an efficient target for growth regulation in bacteria. Here, we show that the nucleoid-associated protein NapM is a DnaA antagonist, protecting M. tuberculosis from stress-mediated killing. NapM can be induced by diverse stressful signals. It binds to DnaA to inhibit both its DNA replication origin-binding and ATP hydrolysis activity. As a DnaA antagonist, NapM inhibits the mycobacterial DNA synthesis in vitro and in vivo in M. tuberculosis. Furthermore, we show that NapM contributes to the survival of M. tuberculosis under stress and within macrophages during infection. Our findings provide a previously unidentified mechanism of mycobacterial survival under stress and also suggest NapM as a potential drug target for tuberculosis control. Yu Liu, Zhiwei Xie et al. show that nucleoid-associated protein NapM enhances the survival of M. tuberculosis in macrophages under stress by inhibiting DNA synthesis as a DnaA antagonist. This study suggests NapM as a potential drug target for tuberculosis control. [ABSTRACT FROM AUTHOR]

Background: Inflammatory markers, including the product of neutrophil count, platelet count, and monocyte count divided by lymphocyte count (PIV) and the platelet‐to‐white blood cell ratio (PWR), have not been previously reported as prognostic factors in nasopharyngeal carcinoma (NPC) patients. In order to predict overall survival (OS) in NPC patients, our goal was to create and internally evaluate a nomogram based on inflammatory markers (PIV, PWR). Methods: A retrospective study was done on patients who received an NPC diagnosis between January 2015 and December 2018. After identifying independent prognostic indicators linked to OS using Cox proportional hazards regression analysis, we created a nomogram with the factors we had chosen. Results: A total of 630 NPC patients in all were split into training (n = 441) and validation sets (n = 189) after being enrolled in a population‐based study in 2015–2018 and monitored for a median of 5.9 years. In the training set, the age, PIV, and PWR, selected as independent predictors for OS via multivariate Cox's regression model, were chosen to develop a nomogram. Both training and validation cohorts had C‐indices of 0.850 (95% confidence interval [CI]: 0.768–0.849) and 0.851 (95% CI: 0.765–0.877). Furthermore, compared with traditional TNM staging, our nomogram demonstrated greater accuracy in predicting patient outcomes. The risk stratification model derived from our prediction model may facilitate personalized treatment strategies for NPC patients. Conclusion: Our findings confirmed the prognostic significance of the PWR and PIV in NPC. High PIV levels (>363.47) and low PWR (≤36.42) values are associated with worse OS in NPC patients. [ABSTRACT FROM AUTHOR]