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We present measurements of the time evolution of plasma and electrical parameters in a pulsed capacitively coupled argon discharge operated at a radio frequency of 12.5 MHz, whose amplitude is ‘step-up’ and ‘step-down’ modulated. The ‘step-up (-down)’ amplitude-modulated waveform consists of three segments, i.e., a low (high)-voltage, a high (low)-voltage, and a zero-voltage stage. Here, we focus on the effect of the ratio (ζ = V L/ V H ⩽ 1) of the low-(V L) to high-voltage (V H) amplitude (measured at the end of the respective segment) on the time evolution of discharge parameters. We monitor the behavior of the discharge by measuring (i) the optical emission intensity (OEI) of a selected Ar-I spectral line, (ii) the electron density at the center of the plasma (using a hairpin probe) as well as (iii) the electrical characteristics (by voltage and current probes). It is found that at relatively large ζ (i.e., at low disparity between the two voltage amplitudes), for both the ‘step-up’ and ‘step-down’ cases, these parameters evolve relatively smoothly with time upon changing the voltage amplitude, and the ignition process strongly depends on the duration of the zero-voltage period. At low ζ (i.e., at high disparity between the voltage amplitudes), an abnormal evolution of the parameters can be observed during the low-voltage period for both cases. Specifically, the voltage amplitude and the modulus of the system impedance increase to a higher value, while the relative phase, φ vi, between the voltage and the current approaches 90°, resulting in a reduction of the power deposition and the OEI. The enhanced voltage amplitude decreases to a steady-state value, accompanied by a decline of φ vi, and an abnormal increase of the current amplitude and the electron density after some time, of which the duration increases with the decrease of ζ. The ζ -dependent evolution of the electron density during the low-voltage period was found to significantly affect the subsequent ignition process and electron power absorption mode at the beginning of the high-voltage period. [ABSTRACT FROM AUTHOR]

Under the new development pattern, the sustainable development of water resources has become the bottleneck restricting the high-quality economic development of Shandong Province. How to investigate the evolution direction and internal mechanism of water resources from a systematic perspective is of great practical significance for coordinating the contradiction between economic growth and ecological construction and comprehensively practising the new development concept. In view of this, through a specific analysis of the water resources system in Shandong Province, this paper hypothesizes the evolution direction of the water resources system : the evolution of the dissipative structure, and constructs the positive entropy measurement model (require pressure effective RPE) and the negative entropy measurement model (provide cushion harmonic PCH) respectively, combined with the escaped "Brussels device" model for a quantitative analysis. The results show that the water resources system in Shandong Province evolved to dissipative structure from 2006 to 2019, but the evolution efficiency is low. Finally, relevant suggestions are put forward for the phenomenon that hinders the evolution of water resources system to dissipative structure. In order to alleviate the shortage of water resources, the construction of the sponge city is strengthened and the key period of industrial transformation is smoothly spent. [ABSTRACT FROM AUTHOR]

Abstract Objective To investigate genetic and antibiotic resistance characteristics of Campylobacter jejuni (C. jejuni) isolated from Shenzhen. Methods Multilocs sequence typing and agar dilution methods were used to define the genotype and antibiotic resistance of C. jejuni, respectively. Results In total, 126 C. jejuni strains were isolated. The prevalence of C. jejuni was 5.3% in diarrheal patients. The prevalence in poultry meat (36.5%) was higher than that in cattle meat (1.1%). However, the prevalence in poultry cloacal swabs (27.0%) was lower than that in cattle stool (57.3%). Sixty-two sequence types were obtained, among which 27 of the STs and 10 alleles were previously unreported. The most frequently observed clonal complexes were ST-21 (11.9%), ST-22 (10.3%), and ST-403 (7.1%). ST-21, ST-45, ST-354, ST-403, and ST-443 complexes overlapped between isolates from patients and cattle, whereas ST-45 and ST-574 complexes overlapped between isolates from patients and poultry. All C. jejuni were resistant to at least one antibiotic. The highest resistance rate was toward ciprofloxacin (89.7%), followed by tetracycline (74.6%), and nalidixic acid (69.0%). Conclusion This is the first report of the genotypes and antibiotic resistance of C. jejuni in Shenzhen. Overlapping clonal complexes were found between isolates from patients and cattle, and between patients and poultry. [ABSTRACT FROM AUTHOR]

Versatile bioinspired strategies are urgently needed to fabricate high-performance nanoprobes for biomedical application. Herein, a novel bioinspired technology of mimicking drug-substrate interaction is reported for the fabrication of high-performance nanoprobes. As a proof of concept, a multifunctional bovine serum albumin (BSA)-MnO2 nanoparticle-based nanoplatform is strategically engineered via mimicking the disinfection process of KMnO4 in an extremely facile way. The prepared BSA-MnO2 nanoparticles possess sub-10 nm and uniform size, excellent colloidal stability, and impressive T1 relaxivity of 7.9 m m−1 s−1. The proposed nanoprobe could not only be employed as a high-performance magnetic resonance imaging (MRI) agent for tumor and renal imaging but can also provide a platform for integrating therapeutic strategies toward tumors. The universal strategy could also be easily extended to the fabrication of other nanoprobes for MR imaging in vivo using other bioactive proteins including ovalbumin and transferrin. This work will open a new way for the development of biomaterials in biomedicine applications. [ABSTRACT FROM AUTHOR]