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Abstract A broadband dual‐polarised reconfigurable frequency selective surface (RFSS) based on general dual‐branch parallel circuit model is proposed by the authors. The specific circuit model is constructed to feature the switchable functions of transmission and reflection characteristics by introducing a parallel branch. It is beneficial to clarify the operating mechanism and provide an effective guidance to satisfy the switching bandwidth requirements of the desired RFSS. In order to validate the proposed concept of the dual‐branch parallel circuit model, a broadband dual‐polarised RFSS prototype has been designed, fabricated and measured. A satisfactory agreement can be reached between the synthesis, simulation and measurement. The experimental results exhibit the merits of low insertion loss, broad switching bandwidth and good angular stability for different polarisation and different incident angles.

Abstract Background Hand, foot, and mouth disease (HFMD) is a common infectious disease occurring in children under 5 years of age worldwide, and Enterovirus A71 (EV-A71) and Coxsackievirus A16 (CVA-16) are identified as the predominant pathogens. In recent years, Coxsackievirus A6 (CVA-6) and Coxsackievirus A10 (CVA-10) have played more and more important role in a series of HFMD outbreaks. This study aimed to understand the epidemic characteristics associated with HFMD outbreak in Guangzhou, 2018. Methods The clinical and laboratory data of 1220 enterovirus-associated HFMD patients in 2018 were analysed in this study. Molecular diagnostic methods were performed to identify its serotypes. Phylogenetic analyses were depicted based on the complete VP1 gene. Results There were 21 enterovirus serotypes detected in Guangzhou in 2018. Three serotypes of enterovirus, CVA-6 (364/1220, 29.8%), CVA-10 (305/1220, 25.0%), and CVA-16 (397/1220, 32.5%), were identified as the causative pathogens and accounted for 87.3% among all 1220 HFMD patients. In different seasons, CVA-6 was the predominant pathogen of HFMD during autumn, and CVA-10 as well as CVA-16 were more prevalent in summer. Patients infected by CVA-6, CVA-10 or CVA-16 showed similar clinical features and laboratory characteristics, and the ratios of severe HFMD were 5.8, 5.9, and 1.5% in the three serotypes. Phylogenetic analyses of VP1 sequences showed that the CVA-6, CVA-10, and CVA-16 sequences belonged to the sub-genogroup E2, genogroup E, and genogroup B1, respectively. Conclusions CVA-6, CVA-10, and CVA-16 were the predominant and co-circulated serotypes in Guangzhou China, 2018, which should be the new target for prevention and control of HFMD. Our findings provide useful information for diagnosis, treatment, and prevention of HFMD.

Abstract Creep behavior is one of the most important mechanical behaviors of coal. In the present study, we systematically carried out a series of creep experiments of briquette samples under triaxial compression and gas pressure. The experimental results showed that the creep deformation characteristics of coal were related to deviatoric stress and gas pressure. The accelerating creep stage initiated when the deviatoric stress reached or exceeded the yield stress until failure took place. In contrast, when the deviatoric stress was less than the yield strength, only transient and steady creep stage occurred. Besides, gas pressure played a positive role in the creep process of coal. The axial strain of coal slightly increased with gas pressure (range from 0.13 to 0.40 MPa) when the effective triaxial stress remained constant. For example, in the steady creep stage (σ1 = 9 MPa, p = 0.13 MPa), the axial strain of sample S1 is 2.710% and that of sample S2 is 3.361%, that is, coal samples with high gas pressure have higher axial strain. Moreover, gas pressure has two main effects on the mechanical behavior of coal. One is that the coal adsorbs gas molecules resulting in swelling strain and swelling stress, and the other is that the gas pressure may compress the coal particles. Considering the swelling stress and gas pressure, we intensively studied the effective stress formula of coal containing gas. Then, the effective stress was taken into consideration in the nonlinear Nishihara creep model. Furthermore, the tertiary creep factor n was introduced in the nonlinear model to control the creep deformation evolution with time so that the nonlinear model could accurately describe the full creep stage of coal. In contrast, due to the lack of such a controlling parameter, the Nishihara model failed to reproduce the accelerating creep stage.

Two new tfmpiq-based bis-cyclometalated iridium(III) complexes, [(tfmpiq)2Ir(imdzppo)] (2a) and [(tfmpiq)2Ir(idzpo)] (2b) (where tfmpiq = 1-(4-(trifluoromethyl)phenyl)isoquinoline, imdzppo = 2-(imidazo[1,2-a]pyridin-2-yl)phenol, idzpo = 2-(2H-indazol-2-yl)phenol), have been synthesized and fully characterized. The single crystal structure of 2b has been determined. The relationship between the structures and photophysical properties of both complexes are considered, and the DFT calculations have been used to further support the deduction. These Ir(III) complexes emit red light with quantum yields of 39.9–51.9% in degassed CH2Cl2 solution at room temperature. Also, their emission originates from a hybrid 3MLCT/3LLCT/3LC excited state. All these results show that iridium(III) complexes 2a-2b are suitable for red-phosphorescent materials in OLEDs.

Two new iridium(III) complexes were synthesized and fully characterized, [(bo)2Ir(pzpy)] (2a) and [(bo)2Ir(pzpyz)] (2b) (where bo = 2-phenylbenzo[d]oxazole, pzpy = 2-(1H-pyrazol-3-yl)pyridine, pzpyz = 2-(1H-pyrazol-3-yl)pyrazine). The single crystal structures of 2a-2b have been determined. Considering the relationship between their structures and photophysical properties, DFT calculations have been used to further support this inference. These Ir(III) complexes emit from the excited state of 3MLCT/3LLCT in the green and yellow region, and the quantum yields in the degassed CH2Cl2 solution at room temperature are 35.2% and 46.1%. Theoretical and experimental results show that iridium(III) complexes 2a-2b are promising phosphorescent material.

Four new cationic iridium (III) complexes: [(cf3piq)2Ir(pzpy)]+PF6- (Ir1), [(cf3piq)2Ir(pzpyz)]+PF6-(Ir2), [(cf3piq)2Ir(impy)]+PF6- (Ir3), and [(cf3piq)2Ir(impyz)]+PF6- (Ir4) (where cf3piq=1-(4-(trifluoromethyl)phenyl)isoquinoline, pzpy=2-(1H-pyrazol-3-yl) pyridine, pzpyz=2-(1H-pyrazol-3-yl)pyrazine, impy=2-(1H-imidazol-2-yl)pyridine, and impyz=2-(1H-imidazol-2-yl)pyrazine) have been synthesized and fully characterized. The single crystal structure of Ir3 has been determined by X-ray diffraction, and confirmed to have two hydrogen bonds (C14-H14···N2 and C57-H57···N9) and one intermolecular p-p stacking interaction. The UV-vis absorption, photoluminescence, and electrochemistry properties of all complexes have been studied. These complexes emit orange-red photoluminescence with quantum yields of 28-46% and excited state lifetimes of 0.48-0.65 µs in CH2Cl2 solution at room temperature. Based on the DFT calculations, we concluded that their emission originated predominantly from a hybrid 3MLCT/3ILCT excited state. [ABSTRACT FROM AUTHOR]

Background: Dengue virus is transmitted by mosquito around the tropical and sub-tropical regions. There was a large-scale dengue epidemic in Guangdong province, China during 2014 and around fifty thousands dengue fever cases, including six deaths, have been reported. In this study, we aimed to understand the clinical characteristics of hospitalized patients with laboratory-confirmed dengue virus (DENV) infection and determined the origin of the virus from the outbreak.Methods: We have summarized the data from 138 hospitalized patients who were laboratory confirmed for dengue infection in Guangzhou city. Patients were classified as either non-severe dengue fever or severe dengue fever according to the guidelines from the WHO. Viral serotypes were determined by real time RT-PCR. Genetic sequences of the envelope and non-structural genes were amplified and analyzed from the serum samples of eleven patients.Results: Co-circulation of dengue serotype 1 and 2 were identified from the outbreak. Patients infected by serotype 1 or 2 showed similar clinical features. Patients with severe dengue fever showed prolonged hospitalization and significant impairment of organ functions. Four samples from serotype 1 and five samples from serotype 2 were closely related respectively and clustered with Guangzhou isolates from previous years. The remaining isolates of serotype 1 were related to viruses found in Malaysia, India, Bangladesh and Singapore.Conclusion: The phylogenetic grouping of Guangdong isolates suggests that dengue is no longer an imported disease in China. Analysis of the isolates obtained in this study together with the size of the outbreak are suggestive of endemic circulation in Guangdong province. [ABSTRACT FROM AUTHOR]

To elucidate the effect of solidification processes on the redispersibility of drug nanocrystals (NC) during freeze-drying, ursodeoxycholic acid (UDCA) nanosuspensions were transformed into UDCA-NC via different solidification process included freezing and lyophilization. The effect of different concentrations of stabilizers and cryoprotectants on redispersibility of UDCA-NC was investigated, respectively. The results showed that the redispersibility of UDCA-NC was RDI−20 °C < RDI−80 °C < RDI−196 °Cduring freezing, which indicated the redispersibility of UDCA-NC at the conventional temperature was better more than those at moderate and rigorous condition. Compared to the drying strengthen, the employed amount and type of stabilizers more dramatically affected the redispersibility of UDCA-NC during lyophilization. The hydroxypropylmethylcellulose and PVPK30 were effective to protect UDCA-NC from damage during lyophilization, which could homogeneously adsorb into the surface of NC to prevent from agglomerates. The sucrose and glucose achieved excellent performance that protected UDCA-NC from crystal growth during lyophilization, respectively. It was concluded that UDCA-NC was subjected to agglomeration during solidification transformation, and the degree of agglomeration suffered varied with the type and the amounts of stabilizers used, as well as different solidification conditions. The PVPK30-sucrose system was more effective to protect UDCA-NC from the damage during solidification process. [ABSTRACT FROM AUTHOR]

The objective of this study was to prepare and characterize ursodeoxycholic acid submicron emulsion (UA-SME) loaded with ursodeoxycholic acid phytosomes (UA-PS) and optimize the process variables. A screening experiment with response surface methodology with Box-Behnken design (BBD) was used to optimize the process parameters of UA-SME. The blood concentrations of UA after oral administration of UA-SME and UA coarse drug were assayed. The optimum process conditions were finally obtained by using a desirability function. It was found that stirring velocity, homogenization pressure and homogenization cycles were the most important variables that affected the particles size, polydispersity index and entrapment efficiency of UA-SME. Results showed that the optimum stirring velocity, homogenization pressure and cycles were 16 000 rpm, 60 MPa and 10 cycles, respectively. The mean diameter, polydispersity index and entrapment efficiency of UA-SME were 251.9 nm, 0.241 and 74.36%, respectively. Pharmacokinetic parameters of UA and UA-SME in rats were Tmax 2.215 and 1.489 h, Cmax 0.0364 and 0.1562 μg/mL, AUC0-∞ 3.682 and 13.756 μg h/mL, respectively. The bioavailability of UA in rats was significantly different ( p < 0.05) after oral administration of UA-SME compared to those of UA coarse drug. This was due to improvement of the hydrophilicity and lipophilic property of UA-SME. [ABSTRACT FROM AUTHOR]