Interfacing Lanthanide Metal-Organic Frameworks with ZnO Nanowires for Alternating Current Electroluminescence.

Alternating current electroluminescence (ACEL) devices are attractive candidates in cost-effective lighting, sensing, and flexible displays due to their uniform luminescence, stable performance, and outstanding deformability. However, ACEL devices have suffered from limited options for the light-emitting layer, which presents a significant constraint in the progress of utilizing ACEL. Herein, a new class of ACEL phosphors based on lanthanide metal-organic frameworks (Ln-MOFs) is devised. A synthesis of lanthanide-benzenetricarboxylate (Ln-BTC) thin film on a brass grid substrate seeded with ZnO nanowires (NWs) as anchors is developed. The as-synthesized Ln-BTC thin film is employed as the emissive layer and shows visible electroluminescence driven by alternating current (2.9 V µm-1 , 1 kHz) for the first time. Mechanistic investigations reveal that the Ln-based ACEL stems from impact excitation by accelerated electrons from ZnO NWs. Fine-tuning of the ACEL color is also demonstrated by controlling the Ln-MOF compositions and introducing an extra ZnS emitting layer. The advances in these optical materials expand the application of ACEL devices in anti-counterfeiting.

First isolation and characterization of Brucella suis from yak.

Brucella spp., facultative intracellular pathogens that can persistently colonize animal host cells and cause zoonosis, affect public health and safety. A Brucella strain was isolated from yak in Qinghai Province. To detect whether this isolate could cause an outbreak of brucellosis and to reveal its genetic characteristics, several typing and whole-genome sequencing methods were applied to identify its species and genetic characteristics. Phylogenetic analysis based on MLVA and whole-genome sequencing revealed the genetic characteristics of the isolated strain. The results showed that the isolated strain is a B. suis biovar 1 smooth strain, and this isolate was named B. suis QH05. The results of comparative genomics and MLVA showed that B. suis QH05 is not a vaccine strain. Comparison with other B. suis strains isolated from humans and animals indicated that B. suis QH05 may be linked to specific animal and human sources. In conclusion, B. suis QH05 does not belong to the Brucella epidemic species in China, and as the first isolation of B. suis from yak, this strain expands the host range of B. suis.

Development and evaluation of a gp85 protein-based subgroup-specific indirect enzyme-linked immunosorbent assay for the detection of anti-subgroup J avian leukosis virus antibodies.

Avian leukosis virus subgroup J (ALV-J) is an important pathogen for various neoplasms and causes significant economic losses in the poultry industry. Serological detection of specific antibodies against ALV-J infection is important for successful clinical diagnosis. Here, a 293F stable cell line was established to stably express gp85 protein. In this cell line, gp85 protein was expressed at approximately 30 mg/L. A subgroup-specific indirect enzyme-linked immunosorbent assay (iELISA) was developed using ALV-J gp85 protein as coated antigen to detect antibodies against ALV-J. The sensitivity of the iELISA (1:51200 diluted in serum) was 16 times more than that of indirect immunofluorescence assay (IFA; 1:3200 diluted in serum). Moreover, there was no crossreactivity with antibodies against other common avian viruses and other avian leukosis virus subgroups, such as subgroups A and B. The practicality of the iELISA was further evaluated by experimental infection and clinical samples. The results from experimental infection indicated that anti-ALV-J antibodies were readily detected by iELISA as early as 4 weeks after ALV-J infection, and positive antibodies were detected until 20 weeks, with an antibody-positive rate of 11.1% to 33.3%. Moreover, analysis of clinical samples showed that 9.49% of samples were positive for anti-ALV-J antibodies, and the concordance rate of iELISA and IFA was 99.24%. Overall, these results suggested that the subgroup-specific iELISA developed in this study had good sensitivity, specificity, and feasibility. This iELISA will be very useful for epidemiological surveillance, diagnosis, and eradication of ALV-J in poultry farms.

Sensitive Luminescence Thermometry through Excitation Intensity Ratio in Eu-Doped BaTiO3.

Optical ratiometric thermometry techniques have gained much attention in recent years due to their reliable and noncontact temperature sensing capability for industrial and biorelated applications. Herein, we exploited the temperature dependence of the absorption band of BaTiO3 (BTO) for novel excitation intensity ratio (EIR) thermometry. Photoluminescence and excitation properties of Eu3+-doped BTO powders were studied as a function of Eu3+ doping concentration. The excitation peak intensities at 397 and 468 nm, corresponding to the 7F0 → 5L6 and 5D2 transitions of Eu3+, were used as EIR parameters. The temperature dependence of the EIR can be explained by the competitive absorption between Eu3+ and the BTO host. The EIR properties were studied in relation to the doping concentration, registering a maximum relative sensitivity (Sr) of 4.89% K-1 in BTO:Eu3+ (0.5%) at 303 K. An amphoteric Eu3+ occupation mode at both Ba2+ and Ti4+ sites was found to interpret the doping concentration dependence of the Sr. The reduced Ba2+ site occupation ratio proved to be responsible for the low Sr values at high Eu3+ doping concentrations. Accordingly, an Eu3+/Ti3+ codoping method was further proposed to improve the Sr by increasing the Ba2+ site occupation ratio. Our result showed that BTO:Eu3+ (0.5%) demonstrated an enhancement of Sr from 4.89 to 6.42% K-1 at 303 K after 2% Ti3+ codoping.

Emerging Halide Perovskite Ferroelectrics.

Halide perovskites have gained tremendous attention in the past decade owing to their excellent properties in optoelectronics. Recently, a fascinating property, ferroelectricity, has been discovered in halide perovskites and quickly attracted widespread interest. Compared with traditional perovskite oxide ferroelectrics, halide perovskites display natural advantages such as structural softness, low weight, and easy processing, which are highly desirable in applications pursuing miniaturization and flexibility. This review focuses on the current research progress in halide perovskite ferroelectrics, encompassing the emerging materials systems and their potential applications in ferroelectric photovoltaics, self-powered photodetection, and X-ray detection. The main challenges and possible solutions in the future development of halide perovskite ferroelectric materials are also attempted to be pointed out.

Prevalence of hypertension in endemic and non-endemic areas of Keshan disease: A cross-sectional study in rural areas of China.

Background: Hypertension is a major public health concern that strongly influences the quality of life of people worldwide. Keshan disease (KD) is an endemic cardiomyopathy related to low selenium, threatening residents in rural areas of 16 provinces in China. Furthermore, the prevalence of hypertension in the KD-endemic areas has been increasing annually. However, hypertension research associated with KD has only focused on endemic regions, and no studies have compared hypertension prevalence between endemic and non-endemic areas. Therefore, this study investigated the prevalence of hypertension to provide a basis for preventing and controlling hypertension in the KD-endemic areas, even in rural areas. Methods: We extracted blood pressure information from cardiomyopathy investigation data from a cross-sectional study of the KD-endemic and non-endemic areas. The hypertension prevalence between the two groups was compared using the Chi-square test or Fisher s exact test. Additionally, Pearson's correlation coefficient was employed to evaluate the relationship between the per capita gross domestic product (GDP) and hypertension prevalence. Results: There was a statistically significant increase of hypertension prevalence in the KD-endemic areas (22.79%, 95% confidence interval [CI]: 22.30-23.27%) over the non-endemic areas (21.55%, 95% CI: 21.09-22.02%). In the KD-endemic areas, more men had hypertension than women (23.90% vs. 21.65%, P < 0.001). Furthermore, the hypertension prevalence was higher in the north than in the south in the KD-endemic areas (27.52% vs. 18.76%, P < 0.001), non-endemic areas (24.86% vs. 18.66%, P < 0.001), and overall (26.17% vs. 18.68%, P < 0.001). Finally, the prevalence of hypertension positively correlated with per capita GDP at province level. Conclusions: The increasing hypertension prevalence is a public health problem in the KD-endemic areas. Healthy diets, such as high consumption of vegetables and seafoods, and foods that are rich in selenium, might help prevent and control hypertension in the KD-endemic areas and other rural areas in China.

A spatial study on Keshan disease prevalence and selenoprotein P in the Heilongjiang Province, China.

OBJECTIVES: Few spatial studies on Keshan disease (KD) prevalence and serum selenoprotein P (SELENOP) levels have been reported in the Heilongjiang Province, China. This study aimed to investigate the spatial relationships between KD prevalence, SELENOP levels, and the socio-economic status for the precise prevention and control of KD. MATERIAL AND METHODS: The study was carried out in all the 66 KD endemic counties in the Heilongjiang Province using a non-probability sampling method of a key village survey based on county-wide case-searching. The participants completed a questionnaire and had their serum SELENOP levels measured using enzyme-linked immunosorbent assay. Thematic maps were created, and spatial regression analysis was performed by ordinary least squares using ArcGIS 9.0. RESULTS: Overall, 53 676 residents were surveyed based on case-searching, and blood samples were collected from 409 residents. In total, 50 chronic KD cases were identified with a total prevalence of 9.3/10 000 population. The prevalence in the Tangyuan County was the highest (250/10 000 population). The mean serum SELENOP level was 13.96 mg/l. The spatial regression analysis showed that KD prevalence positively correlated with SELENOP levels and negatively with per capita disposable income among rural residents. CONCLUSIONS: The Tangyuan County should be considered for the precise prevention and control of KD. Further research is necessary to verify the reliability of SELENOP for estimating body selenium levels, and to better understand the relationship between selenium intake and KD in the investigated area. Int J Occup Med Environ Health. 2021;34(5):659-66.

Fluorescence polarization assay improves the rapid detection of human brucellosis in China.

BACKGROUND: Brucellosis is an infectious-allergic zoonotic disease caused by bacteria of the genus Brucella. Early diagnosis is the key to preventing, treating, and controlling brucellosis. Fluorescence polarization immunoassay (FPA) is a new immunoassay for relatively rapid and accurate detection of antibodies or antigens based on antigen-antibody interaction. However, there is no report on FPA-based detection of human brucellosis in China. Therefore, this study is to evaluate the value of FPA for the diagnosis of human brucellosis in China. METHODS: We recruited 320 suspected brucellosis cases who had the clinical symptoms and epidemiological risk factors between January and December, 2019. According to China Guideline for Human Brucellosis Diagnosis, the Rose Bengal test (RBT) was used for the screening test, and the serum agglutination test (SAT) was used as the confirmatory test. Brucellosis was confirmed only if the results of both tests were positive. Additionally, FPA and enzyme linked immune sorbent assay (ELISA) were compared with SAT, and their sensitivity, specificity, coincidence rate and consistency coefficient (Kappa value) as diagnostic tests were analyzed individually and in combination. The optimal cut-off value of FPA was also determined using the receiver operator characteristic (ROC) curve. RESULTS: The optimum cut-off value of FPA was determined to be 88.5 millipolarization (mP) units, with a sensitivity of 94.5% and specificity of 100.0%. Additionally, the coincidence rate with the SAT test was 96.6%, and the Kappa value (0.9) showed excellent consistency. The sensitivity and specificity of FPA and ELISA combined were higher at 98.0% and 100.0% respectively. CONCLUSIONS: When the cut-off value of FPA test is set at 88.5 mP, it has high value for the diagnosis of brucellosis. Additionally, when FPA and ELISA are combined, the sensitivity of diagnosis is significantly improved. Thus, FPA may have potential in the future as a diagnostic method for human brucellosis in China.

Association of selenium levels with the prevention and control of Keshan disease: A cross-sectional study.

PURPOSE: The prevalence of Keshan disease (KD) is low and has reached controlled or eliminated levels even in counties that had a high KD prevalence in the past. Few nationwide surveys on selenium levels in KD areas have been conducted in the past 2 decades. We conducted a cross-sectional study to investigate the selenium levels and their association with KD control and prevention in areas where KD is prevalent. METHODS: We collected 2143 human-hair, 698 soil, 701 rice, 607 flour, 521 corn, and 330 other-food samples from 49 counties with KD and 19 non-KD counties of nine KD provinces of China. The selenium content of samples was examined with hydride generation atomic fluorescence spectrometry. The difference in selenium levels between the KD and non-KD areas was analyzed. Cochran-Armitage trend tests were used to evaluate the association between selenium levels and KD control. RESULTS: The selenium levels in human hair, soil, staple foods, and other foods in the KD areas (0.2996 mg/kg, 0.1380 mg/kg, 0.0190 mg/kg and 0.0076 mg/kg, respectively) were lower than those in the non-KD areas (0.3700 mg/kg, 0.1930 mg/kg, 0.0240 mg/kg and 0.0165 mg/kg, respectively). The Cochran-Armitage tests showed that there was a trend for the selenium standard ratio in the counties to increase in the order of KD uncontrolled, to controlled, to eliminated (Z = 2.229, P < 0.05). CONCLUSION: The residents in the KD areas were found to be selenium-deficient. Improving the supply of staple foods containing selenium levels exceeding 0.025 mg/kg and abundant foodstuffs might contribute to KD control and prevention.