RESUMO
Efficient coupling in broad wavelength range is desirable for wide-spectrum infrared light detection, yet this is a challenge for intersubband transition in semiconductor quantum wells (QWs). High-Q cavities mostly intensify the absorption at peak wavelengths but with shrinking bandwidth. Here, we propose a novel approach to expand the operating spectral range of the Quantum Well Infrared Photodetectors (QWIPs). By processing the QWs into asymmetric micro-pillar array structure, the device demonstrates a substantial enhancement in spectral response across the wavelength from 7.1 µm to 12.3 µm with guided mode resonance (GMR) effects. The blackbody responsivity is then increased by 3 times compared to that of the 45° polished edge-coupled counterpart. Meanwhile, the dark current density remains unchanged after the deep etching process, which will benefit the electrical performance of the detector with reduced volume duty ratio. In contrast to the symmetric micro-pillar array that contains simple resonance mode, the detectivity of QWIP in asymmetric pillar structure is found to be improved by 2-4 times within the range of 9.5 µm to 15 µm.
RESUMO
OBJECTIVE: To analyze the laboratory diagnosis results and epidemiological characteristics of imported malaria cases in Chongqing Municipality in 2015. METHODS: According to the Standard Operating Procedures of Malaria Diagnosis Reference Laboratory Manual, all the blood samples collected from the imported malaria patients were detected by microscopy, RDT and nest PCR. Meanwhile, the epidemiological data of the malaria cases were collected from the Parasitic Diseases Information Management System and analyzed. RESULTS: Totally 31 cases of imported malaria were reported in Chonqing Municipality in 2015, among which, there were 2 vivax malaria cases (6.45%), 23 falciparum malaria cases (74.19%), 5 ovale malaria cases (16.13%), 1 malariae malaria case (3.22%). For the 5 ovale cases, three of them were confirmed as Plasmodium ovale wallikeri infection. Among all the cases, 30 cases (96.77%) were from African countries, 1(3.33%) was from Southeast Asia. Thirty patients were male, and 1 was female. All the patients were aged from 23-61 years. There was no obvious seasonality in the case distribution. Both the medians of duration from malaria attack to first visiting a doctor and from first visiting a doctor to diagnosis were 2 days. The medical care units that the patients first visited were mainly county-level units, while those that made the diagnosis were mainly provincial level institutes. CONCLUSIONS: All the malaria cases in Chongqing in 2015 are imported, no local cases have been found, which suggests that this municipality still maintain the malaria elimination state. However, the monitoring and management of imported malaria cases as well as the training on malaria control for related medical staff still need to be strengthened.