Observation of photonic Peierls transition for manipulating microwave in metallic diaphragm-array periodic structures.

Peierls transition that modifies electronic band structure has attracted intensive attention in solid state physics. In the present work, we report that a photonic analog of Peierls transition has been observed in a 1-D triangular metal diaphragm array, where the photonic bandgap structures have been designed at will by adjusting periodically metal diaphragm positions. It is shown by the numerical analysis that the transmission and radiation effect of the present periodic metal structure designed through the Peierls transition rule exhibits the behavior significantly different from an original periodic structure with each unit cell containing a metal diaphragm. The near- and far-field measurement results are in good agreement with our theoretical simulation. The present effect of photonic Peierls transition can serve as a working mechanism for designing new types of guided wave devices. It can be seen that the photonic Peierls transition would be one of the simplest ways for modifying the transport characteristics of electromagnetic waves in periodic structures.

A kind of planar waveguides for cheating the high-speed digital signals into misidentifying the characteristic impedance.

Since a planar periodic transmission line can suppress drastically the electromagnetic coupling, it would be advantageous to use such a kind of transmission lines in solving the problem of miniaturization of circuit area. By adjusting the lattice constants and geometric parameters of periodic microstrip lines, a time domain characteristic impedance that is the same as that of conventional microstrip lines (CMLs) can be achieved. Such periodic microstrip lines can therefore be used to trick high-speed digital signals, causing a digital signal to misjudge the time domain characteristic impedance of the transmission lines. The theoretical analysis has been verified by our experimental measurement results. Besides, a specific expression for the characteristic impedance of lossless periodic artificial materials is deduced by a circuit model and a standard of misidentification for the characteristic impedance of periodic microstrip lines is given for the digital signals.

Epidemiological Characteristics and the Dynamic Transmission Model of Dengue Fever in Zhanjiang City, Guangdong Province in 2018.

Background: With the progress of urbanization, the mobility of people has gradually increased, which has led to the further spread of dengue fever. This study evaluated the transmissibility of dengue fever within districts and between different districts in Zhanjiang City to provide corresponding advice for cross-regional prevention and control. Methods: A mathematical model of transmission dynamics was developed to explore the transmissibility of the disease and to compare that between different regions. Results: A total of 467 DF cases (6.38 per 100,000 people) were reported in Zhanjiang City in 2018. In the model, without any intervention, the number of simulated cases in this epidemic reached about 950. The dengue fever transmissions between districts varied within and between regions. When the spread of dengue fever from Chikan Districts to other districts was cut off, the number of cases in other districts dropped significantly or even to zero. When the density of mosquitoes in Xiashan District was controlled, the dengue fever epidemic in Xiashan District was found to be significantly alleviated. Conclusions: When there is a dengue outbreak, timely measures can effectively control it from developing into an epidemic. Different prevention and control measures in different districts could efficiently reduce the risk of disease transmission.

Dengue fever transmission between a construction site and its surrounding communities in China.

BACKGROUND: Due to an increase in mosquito habitats and the lack facilities to carry out basic mosquito control, construction sites in China are more likely to experience secondary dengue fever infection after importation of an initial infection, which may then increase the number of infections in the neighboring communities and the chance of community transmission. The aim of this study was to investigate how to effectively reduce the transmission of dengue fever at construction sites and the neighboring communities. METHODS: The Susceptible-Exposed-Infectious/Asymptomatic-Recovered (SEIAR) model of human and SEI model of mosquitoes were developed to estimate the transmission of dengue virus between humans and mosquitoes within the construction site and within a neighboring community, as well between each of these. With the calibrated model, we further estimated the effectiveness of different intervention scenarios targeting at reducing the transmissibility at different locations (i.e. construction sites and community) with the total attack rate (TAR) and the duration of the outbreak (DO). RESULTS: A total of 102 construction site-related and 131 community-related cases of dengue fever were reported in our area of study. Without intervention, the number of cases related to the construction site and the community rose to 156 (TAR: 31.25%) and 10,796 (TAR: 21.59%), respectively. When the transmission route from mosquitoes to humans in the community was cut off, the number of community cases decreased to a minimum of 33 compared with other simulated scenarios (TAR: 0.068%, DO: 60 days). If the transmission route from infectious mosquitoes in the community and that from the construction site to susceptible people on the site were cut off at the same time, the number of cases on the construction site dropped to a minimum of 74 (TAR: 14.88%, DO: 66 days). CONCLUSIONS: To control the outbreak of dengue fever effectively on both the construction site and in the community, interventions needed to be made both within the community and from the community to the construction site. If interventions only took place within the construction site, the number of cases on the construction site would not be reduced. Also, interventions implemented only within the construction site or between the construction site and the community would not lead to a reduction in the number of cases in the community.

Positive correlation between cognitive impairment and renal microangiopathy in patients with type 2 diabetic nephropathy: a multicenter retrospective study.

OBJECTIVE: This study was performed to explore the correlation between cognitive impairment and renal microangiopathy in patients with type 2 diabetic nephropathy (T2DN) by detecting changes in cognitive function and cerebral metabolism in these patients with different stages of T2DN. METHODS: Prospectively maintained databases were reviewed from 2006 to 2017. Blood biochemical indexes and the urinary albumin excretion rate (UAER) were measured in all participants. Cognitive function was assessed by the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment Scale (MoCA). Cognitive impairment was the primary endpoint. Renal microangiopathy was the secondary endpoint. Pearson correlation analysis was used to assess correlations. RESULTS: Two hundred sixteen patients with type 2 diabetes mellitus (T2DM) were divided into three groups according to their UAER: T2DM without nephropathy (n=72), early T2DM with nephropathy (n=74), and the clinical stage of early T2DM with nephropathy (n=70). Healthy participants were selected as the normal control group (n=70). Pearson correlation analysis demonstrated that the total MMSE and MoCA score was negatively correlated with the UAER (r=-0.327) and positively correlated with the estimated glomerular filtration rate (r=0.428) in patients with T2DN. CONCLUSIONS: The present study showed a positive correlation between cognitive impairment and renal microangiopathy in patients with T2DN.

[APPLICATION OF ONE STAGE VACUUM SEALING DRAINAGE COMBINED WITH BI-PEDICLE SLIDING FLAP TRANSPLANTATION FOR OPEN TIBIOFIBULAR FRACTURE AND SOFT TISSUE DEFECTS OF THE LOWER LEG].

OBJECTIVE: To evaluate the effectiveness of one stage vacuum sealing drainage (VSD) combined with bi-pedicle sliding flap transplantation in repairing open tibiofibular fracture and soft tissue defects of the lower leg. METHODS: Twenty-five patients with open tibiofibular fracture and soft tissue defects of the lower leg were treated by VSD combined with bi-pedicle sliding flap transplantation between January 2012 and July 2014. There were 18 males and 7 females, aged 12-65 years (mean, 35.2 years). The injury causes included traffic accident injury (20 cases), falling injury from height (3 cases), and heavy pound injury (2 cases). The left side was involved in 14 cases, the right side in 8 cases, and both sides in 3 cases. According to Gustilo classification, injury was rated as type II (6 lower extremities), type III a (19 lower extremities), and type III b (3 lower extremities). The anterior tibial defect area after debridement ranged from 6 cmx3 cm to 12 cmx5 cm. The course of injury and admission was 1-18 hours (mean, 4.5 hours). An anterior tibial bi-pedicle sliding flap of 24 cmx6 cm to 48 cmx8 cm was designed to cover the wound and tibia fracture was fixed with minimally invasive internal fixation. After suturing the anterior tibial wound without tension, the flap was transferred forward. The exposed fibula was fixed with reconstruction plate. The remained wound was covered by VSD. Continuously antibiotic saline irrigation was applied postoperatively. After 15 days, the VSD dressing was removed and free skin graft was used to cover the remained wound. RESULTS: After the VSD dressing was removed, the wounds and tension-reduced wound of 18 lower extremities completely healed. Unhealing wounds were covered by skin graft in 9 lower extremities. Infection occurred in 1 lower extremity and was cured after treated with antibiotics. All the wounds healed and flaps survived. The patients were followed up 6-24 months (mean, 18 months). The fractures union was confirmed by X-ray and the average union time was 3.2 months (range, 2.5-5 months). CONCLUSION: The application of one stage VSD combined with bi-pedicle sliding flap transposition is a simple and safe treatment regimen for Gustilo type II-IIIa open tibiofibular fracture and soft tissue defects of the lower leg. It has the advantages of few complications and low costs, short hospitalization, and good effectiveness.