Sulfur oxidation is an essential component of the earth's sulfur cycle.
spp. can oxidize various reduced inorganic sulfur compounds (RISCs) with high efficiency to obtain electrons for their ...autotrophic growth. Strains in this genus have been widely applied in bioleaching and biological desulfurization. Diverse sulfur-metabolic pathways and corresponding regulatory systems have been discovered in these acidophilic sulfur-oxidizing bacteria. The sulfur-metabolic enzymes in
spp. can be categorized as elemental sulfur oxidation enzymes (sulfur dioxygenase, sulfur oxygenase reductase, and Hdr-like complex), enzymes in thiosulfate oxidation pathways (tetrathionate intermediate thiosulfate oxidation (S
I) pathway, the sulfur oxidizing enzyme (Sox) system and thiosulfate dehydrogenase), sulfide oxidation enzymes (sulfide:quinone oxidoreductase) and sulfite oxidation pathways/enzymes. The two-component systems (TCSs) are the typical regulation elements for periplasmic thiosulfate metabolism in these autotrophic sulfur-oxidizing bacteria. Examples are RsrS/RsrR responsible for S
I pathway regulation and TspS/TspR for Sox system regulation. The proposal of sulfur metabolic and regulatory models provide new insights and overall understanding of the sulfur-metabolic processes in
spp. The future research directions and existing barriers in the bacterial sulfur metabolism are also emphasized here and the breakthroughs in these areas will accelerate the research on the sulfur oxidation in
spp. and other sulfur oxidizers.
In this paper, a new-type of mechanical-motion-rectifier-based energy harvesting shock absorber using a ball-screw mechanism and two one-way clutches is proposed to replace conventional oil dampers ...in vehicle suspensions. The proposed energy-harvesting shock absorber can work as a controllable shock absorber as well as an energy harvester. The challenge to harvest energy from reciprocating suspension vibration is solved by integrating a mechanical motion rectifier in the proposed design, which can convert reciprocating vibration into unidirectional rotation of a generator. As a result, the proposed shock absorber achieves high energy-harvesting efficiency by enabling the generator to rotate at a relatively steady speed during irregular vibrations and improves system reliability by reducing impact forces in transmission gears. In addition, the backlash of the proposed shock absorber is significantly reduced due to the use of the ball-screw mechanism, which further increases transmission durability and efficiency. Lab and field tests are carried out to experimentally characterize the proposed energy-harvesting shock absorber. The field testing results show that, when the modified vehicle is driven on a paved road at 40 mph, the proposed energy-harvesting shock absorber is able to reduce the root-mean-square value of chassis acceleration by 11.12% over the oil shock absorber and simultaneously harvest an average power of 13.3 W for a representative period of 8 s.
Among all the stromal cells that present in the tumor microenvironment, cancer-associated fibroblasts (CAFs) are one of the most abundant and critical components of the tumor mesenchyme, which not ...only provide physical support for tumor cells but also play a key role in promoting and retarding tumorigenesis in a context-dependent manner. CAFs have also been involved in the modulation of many components of the immune system, and recent studies have revealed their roles in immune evasion and poor responses to cancer immunotherapy. In this review, we describe our current understanding of the tumorigenic significance, origin, and heterogeneity of CAFs, as well as the roles of different CAFs subtypes in distinct immune cell types. More importantly, we highlight potential therapeutic strategies that target CAFs to unleash the immune system against the tumor.
This article studies the robust trajectory tracking control problem of a quadrotor unmanned aerial vehicle (UAV). In order to guarantee the desired trajectory tracking performance in the presence of ...external disturbances and model uncertainties, the design process of the quadrotor UAV controller is divided into two steps. First, by decomposing the attitude dynamic system into two serial-connected subsystems, a cascade active disturbance rejection control scheme is applied to the attitude subsystem. Second, by introducing an additional high-gain design parameter, a novel backstepping sliding-mode control scheme for position subsystem is constructed. Moreover, the Lyapunov stability analysis is provided to show that the trajectory tracking error can converge to an arbitrarily small residual set. Numerical results illustrate the effectiveness of the designed control method and its robustness to the external disturbances and model uncertainties. Finally, the proposed method is implemented on a quadrotor UAV to demonstrate its feasibility in practical application.
Simultaneously achieving a high photoluminescence quantum yield (PLQY), ultrashort exciton lifetime, and suppressed concentration quenching in thermally activated delayed fluorescence (TADF) ...materials is desirable yet challenging. Here, a novel acceptor–donor–acceptor type TADF emitter, namely, 2BO‐sQA, wherein two oxygen‐bridged triarylboron (BO) acceptors are arranged with cofacial alignment and positioned nearly orthogonal to the rigid dispirofluorene‐quinolinoacridine (sQA) donor is reported. This molecular design enables the compound to achieve highly efficient (PLQYs up to 99%) and short‐lived (nanosecond‐scale) blue TADF with effectively suppressed concentration quenching in films. Consequently, the doped organic light‐emitting diodes (OLEDs) base on 2BO‐sQA achieve exceptional electroluminescence performance across a broad range of doping concentrations, maintaining maximum external quantum efficiencies (EQEs) at over 30% for doping concentrations ranging from 10 to 70 wt%. Remarkably, the nondoped blue OLED achieves a record‐high maximum EQE of 26.6% with a small efficiency roll‐off of 14.0% at 1000 candelas per square meter. By using 2BO‐sQA as the sensitizer for the multiresonance TADF emitter ν‐DABNA, TADF‐sensitized fluorescence OLEDs achieve high‐efficiency deep‐blue emission. These results demonstrate the feasibility of this molecular design in developing TADF emitters with high efficiency, ultrashort exciton lifetime, and minimal concentration quenching.
A novel acceptor–donor–acceptor type molecular skeleton is designed to realize blue thermally activated delayed fluorescence with ultrahigh emission efficiencies (up to 99%), nanosecond exciton lifetimes, and effectively suppressed concentration quenching in films. The doped and nondoped organic light‐emitting diodes attain high external quantum efficiencies up to 32.0% and 26.6%, respectively.
Summary
Accurate and high‐fidelity finite element (FE) models are in great demand in the design, performance assessment, and life‐cycle maintenance of long‐span cable‐stayed bridges. The structural ...system of a long‐span cable‐stayed bridge is often huge in size and complex with many components connected and various materials constituted. Therefore, the FE model of a long‐span cable‐stayed bridge involves a large number of elements and nodes with many uncertainties. The model updating of the FE model to best represent a real bridge is necessary but very challenging. One of the challenging issues is that the numerical computation needed for searching the global optimum of a large set of structural parameters is so extensive that the existing FE (not surrogate) model‐based updating methods cannot fulfill this task. In this study, a cluster computing‐aided FE model updating framework is proposed for the high‐performance FE model updating of large and complex structures. In the framework, several computer software packages, including MSC.Marc, Python, and MATLAB, are interconnected for making use of their respective functions of strength. The shake table test of a scaled physical structure of the Sutong cable‐stayed bridge in China is used to validate the accuracy and efficiency of the proposed framework. The simulated bridge responses based on the updated FE model are in good agreement with the measured ones from the shake table test. The successful application of the proposed framework provides a reference for the model updating of other types of large and complex structures.
Advanced glycation end products (AGEs), a group of compounds that are formed by non-enzymatic reactions between carbonyl groups of reducing sugars and free amino groups of proteins, lipids or nucleic ...acids, can be obtained exogenously from diet or formed endogenously within the body. AGEs accumulate intracellularly and extracellularly in all tissues and body fluids and can cross-link with other proteins and thus affect their normal functions. Furthermore, AGEs can interact with specific cell surface receptors and hence alter cell intracellular signaling, gene expression, the production of reactive oxygen species and the activation of several inflammatory pathways. High levels of AGEs in diet as well as in tissues and the circulation are pathogenic to a wide range of diseases. With respect to mobility, AGEs accumulate in bones, joints and skeletal muscles, playing important roles in the development of osteoporosis, osteoarthritis, and sarcopenia with aging. This report covered the related pathological mechanisms and the potential pharmaceutical and dietary intervention strategies in reducing systemic AGEs. More prospective studies are needed to determine whether elevated serum AGEs and/or skin autofluorescence predict a decline in measures of mobility. In addition, human intervention studies are required to investigate the beneficial effects of exogenous AGEs inhibitors on mobility outcomes.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
Transparent conductive electrodes, as transmission windows of photons and electrons, play important roles in high‐performance organic optoelectronic devices. The replacement of widely used indium tin ...oxide (ITO) electrodes has been attempted due to the increasing cost and intrinsically brittle characteristics of ITO. Ultrathin metal films, with excellent optoelectrical features, high flexibility, and sufficient mechanical stability, have been considered a potential candidate for the use as transparent conductive electrodes. However, ultrathin metal films follow the Volmer–Weber mechanism, resulting in a rough and discontinuous morphology with poor optoelectrical properties due to the bad adhesion to substrates. This review summarizes the progress in strategies for preparing ultrathin and ultrasmooth metal films with superior transmittance and conductivity by successfully suppressing the Volmer–Weber mechanism. The electrical and optical performances of the ultrathin metal films based on improved nucleation processes, as well as applications in ITO‐free organic optoelectronic devices, are also described and discussed in detail.
The development of ultrathin metal films with improved metal nucleation processes based on various strategies is summarized in this review. The great progress in the properties of ultrathin metal films as well as their application in indium tin oxide (ITO)‐free organic optoelectronic devices as transparent conductive electrodes are described.
The occurrence of sulfonamide and tetracycline resistance and their pollution profile in the aquaculture environment of Tianjin, northern China, were investigated. The presence of ...antibiotic-resistant bacteria was identified and the corresponding antibiotic resistance genes (ARGs) were quantified at 6 aquaculture farms in Tianjin. Sulfonamide-resistance genes were prevalent and their concentrations were the highest detected (3.0×10−5 to 3.3×10−4 for sul1/16S rDNA, 2.0×10−4 to 1.8×10−3 for sul2/16S rDNA) among the various ARGs, most likely because the use of sulfonamides is more prevalent than tetracyclines in this area. Bacillus was the most dominant bacterial genus in both sulfamethoxazole resistant bacteria (63.27% of the total resistant bacteria) and tetracycline-resistant bacteria (57.14% of the total resistant bacteria). At least two of those genes (tetM, tetO, tetT, tetW, sul1 and sul2) were detected in the isolates of Bacillus cereus, Bacillus subtilis, Bacillus megaterium and Acinetobacter lwofii, and all of the above genes were detected in B. cereus, suggesting the occurrence of multi-resistance in the studied area. The genetic transfer of sul1 between intestinal bacteria (e.g., Enterococcus spp.) and indigenous bacteria (e.g., Bacillus spp.) was implied by phylogenetic analysis. Several strains of resistant opportunistic pathogens (e.g., Acinetobacter spp.) were found in indigenous bacteria, which increase the risk of ARGs to public health. Overall, this is the first study to comprehensively investigate the antibiotic resistance profile by analyzing the species of antibiotic-resistant bacteria and adopting qualitative and quantitative methods to investigate ARGs at a typical aquaculture area in northern China.
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► We studied antibiotic resistance genes and resistant bacteria in aquaculture environment of Tianjin. ► Sulfonamide-resistance genes were prevalent. ► Bacillus was the most dominant bacterial genus in SMXr and TCr bacteria. ► Several strains of resistant opportunistic pathogens were found in indigenous bacteria.
•Household waste separation may end in failure due to the free-rider problem.•Economic rewards work better than social influence in promoting waste separation.•The effects of both strategies are ...partially mediated by self-efficacy.•Personal norms are not a significant mediated factor.
China has experienced a rapid growth of solid waste over the years, household waste source-separation is becoming a nationwide strategy for promoting recycling economy and improving urban environmental sustainability. Waste separation, however, may end in failure due to the free-rider problem similarly existing in other pro-environmental collective actions. Along with the economic and sociological/social psychological logic respectively, this study tested the effects of economic incentive and social influence, which are theoretically considered as two general solutions to domestic waste separation dilemma. One hundred and eighty-eight residents in the three communities of Hangzhou, Zhejiang Province were assigned to a control group or one of two experimental scenarios, where they were encouraged to participate in waste separation activities through either the economic rewards given on their performance, or door-stepping campaigns aimed at constructing a supportive social environment. Six-month intervention effects were analyzed and showed that economic inducement was more effective than social mobilization in promoting waste separation. Further mediation tests indicated that self-efficacy partially mediated the effects of both strategies, while personal norms were positively associated with two treatments instead of behavior demonstration. In addition, the moderating effects of several socio-demographic factors on psychological mechanisms were also explored. The findings, limitations and implications for future research and policy are discussed in the concluding section.
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