Neutral point detection using the AOP of polarized skylight patterns.

The neutral points are one of the most significant characteristics of the polarized skylight pattern in the whole sky. At present, detection of the neutral points mostly utilizes ellipse fitting of the degree of polarization. However, because the degree of polarization distribution characteristics of a polarized skylight pattern is easily affected by the environment, the robustness of the detection is unstable. Aiming at the problem, we analyzed the angle of polarization distribution characteristics of polarized skylight patterns in the region around the neutral point by measurement experiments. Based on this, we proposed an automatic detection method of neutral points using the angle of polarization of the polarized skylight pattern. The experimental results of different times in a continuous period of time show that compared with ellipse fitting of the degree of polarization, the detection accuracy of the proposed method is almost the same, but the robustness is better. It provides a novel method for the position detecting of the neutral point, which is in favor of the measurement applications of polarization technology.

Acute kidney injury in China: a cross-sectional survey.

BACKGROUND: Acute kidney injury (AKI) has become a worldwide public health problem, but little information is available about the disease burden in China. We aimed to evaluate the burden of AKI and assess the availability of diagnosis and treatment in China. METHODS: We launched a nationwide, cross-sectional survey of adult patients who were admitted to hospital in 2013 in academic or local hospitals from 22 provinces in mainland China. Patients with suspected AKI were screened out on the basis of changes in serum creatinine by the Laboratory Information System, and we reviewed medical records for 2 months (January and July) to confirm diagnoses. We assessed rates of AKI according to two identification criteria: the 2012 Kidney Disease: Improving Global Outcomes (KDIGO) AKI definition and an increase or decrease in serum creatinine by 50% during hospital stay (expanded criteria). We estimated national rates with data from the 2013 report by the Chinese National Health and Family Planning Commission and National Bureau of Statistics. FINDINGS: Of 2,223,230 patients admitted to the 44 hospitals screened in 2013, 154,950 (7·0%) were suspected of having AKI by electronic screening, of whom 26,086 patients (from 374,286 total admissions) were reviewed with medical records to confirm the diagnosis of AKI. The detection rate of AKI was 0·99% (3687 of 374,286) by KDIGO criteria and 2·03% (7604 of 374,286) by expanded criteria, from which we estimate that 1·4-2·9 million people with AKI were admitted to hospital in China in 2013. The non-recognition rate of AKI was 74·2% (5608 of 7555 with available data). Renal referral was done in 21·4% (1625 of 7604) of the AKI cases, and renal replacement therapy was done in 59·3% (531 of 896) of those who had the indications. Delayed AKI recognition was an independent risk factor for in-hospital mortality, and renal referral was an independent protective factor for AKI under-recognition and mortality INTERPRETATION: AKI has become a huge medical burden in China, with substantial underdiagnosis and undertreatment. Nephrologists should take the responsibility for leading the battle against AKI. FUNDING: National 985 Project of China, National Natural Science Foundation of China, Beijing Training Program for Talents, International Society of Nephrology Research Committee, and Bethune Fund Management Committee.

Nutritional and physicochemical characteristics of purple sweet corn juice before and after boiling.

Sweet corn juice is becoming increasingly popular in China. In order to provide valuable health-related information to consumers, the nutritional and physicochemical characteristics of raw and boiled purple sweet corn juices were herein investigated. Sugars, antinutrients, total free phenols, anthocyanins, and antioxidant activity were analyzed by conventional chemical methods. The viscosity and stability of juices were determined by Ubbelohde viscosity meter and centrifugation, respectively. Boiling process could elevate viscosity, stability and sugar content, and reduce antinutrients, total free phenols, anthocyanins, and antioxidant activity in corn juice. In addition, short time boiling efficiently reduced the degradation of anthocyanins during subsequent refrigeration. The content of amino acids, vitamin B1/B2 and E were detected by High Performance Liquid Chromatography. Gas Chromatography Mass Spectrometry was used for the analysis of fatty acids and aroma compounds. Several aroma compounds not previously reported in corn were identified, including 1-heptanol, 2-methyl-2-butenal, (Z)-3-nonen-1-ol, 3-ethyl-2-methyl-1,3-hexadiene, and 2,4-bis(1,1-dimethylethyl)phenol. Interestingly, the boiling process had no apparent effect on the amino acids profile, but it caused a 45.8% loss of fatty acids in the juice by promoting the retention of fatty acids in the corn residue. These results provide detailed information that could be used for increasing consumers' knowledge of sweet corn juice, further development of sweet corn juice by food producers, and maize breeding programs.