The main challenge in Raman detection of pesticide residues in agricultural products is matrix interference, which hinders accurate identification of trace compounds in complicated agricultural ...samples. In this study, a novel surface-enhanced Raman spectroscopy approach based on magnetic molecularly imprinted polymers (MMIP-SERS) was introduced for the rapid analysis of myclobutanil and tebuconazole in apples. The synthesized magnetic molecularly imprinted polymer selectively adsorbed triazole pesticides, effectively eliminating matrix interference in real samples. The saturation adsorption time for MMIPs was only 10 min. In addition, the synthesized colloidal gold served as an excellent substrate for enhancing the specific signals for myclobutanil and tebuconazole. We successfully identified the characteristic peak of tebuconazole at 1089 cm−1, while myclobutanil showed its characteristic peak at 632 cm−1. The series of experiments and recovery tests confirmed the high sensitivity of the developed MMIP-SERS method using colloidal gold as an enhanced substrate for fungicide analysis in apple samples. The linear detection ranges for myclobutanil and tebuconazole in apples were determined to be 0.2–10 mg/kg and 0.5–10 mg/kg, respectively. The limit of detection was 0.09 mg/kg for tebuconazole and 0.05 mg/kg for myclobutanil. This study provides a rapid and simple method for detecting myclobutanil and tebuconazole based on the synergistic effect of the imprinted polymer and SERS with good separation and detection performance.
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•The newly magnetic molecularly imprinted polymers (MMIPs) were synthesized.•The obtained MMIPs presented good class-specific adsorption of triazole pesticides.•The MMIP-SERS method for detecting tebuconazole and myclobutanil was developed and proved to be sensitive, simple and rapid.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
To characterize the strains of Anaplasma phagocytophilum in wild and domestic animals in China, we isolated the organism from rodents and sheep in northeastern China. We isolated 3 strains (2 from ...rodents and 1 from sick sheep) through propagation in BALB/c mice and then cell culture in HL60 cells. The 3 isolates were identified by Wright-Giemsa staining, immunofluorescence, and electronic microscopy and were characterized by sequence analyses of the 16S rRNA gene, partial citrate synthase gene, major surface protein 4 gene, and heat shock protein gene. The multiple sequences of the 3 isolates were identical to each other but different from all known strains from other countries. The public health and veterinary relevance of the isolates deserves further investigation.
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DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We analyzed the epidemiological data during 1990-2012 that investigated the blood lead level (BLL) in the population aged 0-18 years old in China mainland and provided evidence of the benefits of ...implementing policies to prevent lead pollution based on the dynamic changes of BLL. Data were collected through databases including China Knowledge Resource Integrated Database (CNKI), CBM disc, Wanfang Data, Pubmed and Medline. The inclusion criteria were: 1. Epidemiological study in healthy population not included studies limited to specific patient; 2. Study subject was not the specific lead exposure population; 3. Sample size should be no less than 100 (for neonatal, no less than 50); 4. BLL detection was under strict quality control; and 5. Results should be presented as BLL (arithmetic mean level or geometric mean level). 62 articles were included in this study. All the surveys in these articles contained 189,352 subjects in 19 provinces, autonomous regions and municipalities. Linear regression analysis showed a significant decrease between 1990 and 2012 with an estimated regression coefficient of 3.05/year (SE=0.01, p<0.001). BLL gradually declined since early 21st century. Median levels of BLL among the three economic zones were 51.4 μg/L in the eastern zone, 52.72 μg/L in the central zone and 46.2 μg/L in the western zone respectively. Median BLLs in male and female population aged 0-18 years old of China were 48.8 μg/L and 46.1μg/L. Median levels of BLL among the different age ranges were 74.9 μg/L in newborn, 46.4 μg/L in 0 to 3 years old, 57.6 μg/L in 3 to 7 years old and 55.6 μg/L in above 7 years old respectively. In conclusion, the BLL in the Chinese population of 0-18 years old has gradually dropped in the past 10 years. The decline in temporal trend still remains under potential impacts of several factors such as economical level, gender and age difference. Although, China has made significant achievements in the control prevention of lead pollution, concerted efforts are still warranted to reduce children lead poisoning.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The online property of fountain codes enables the encoder to efficiently find the optimal encoding strategy that minimizes the encoding overhead based on the instantaneous decoding state. Therefore, ...the receiver is able to optimally recover data from losses that differ significantly from the initial expectation. In this paper, we propose a framework to analyze the relationship between overhead and the number of recovered source symbols for online fountain codes based on random graph theory. Motivated by the analysis, we propose improved online fountain codes (IOFCs) by introducing a designated selection of source symbols. Theoretical analysis shows that IOFC has lower overhead compared with the conventional online fountain codes. We verify the proposed analysis via simulation results and demonstrate the tradeoff between full recovery and intermediate performance in comparison to other online fountain codes.
Anaplasma phagocytophilum was detected by polymerase chain reaction in 13 (14.1%) of 92 rodents captured from a mountainous area of Zhejiang Province in southeastern China. The nucleotide sequences ...of 1442-bp, nearly entire 16S rRNA gene amplified from these rodents, had 100% identity, but varied from all known corresponding sequences of A. phagocytophilum deposited in GenBank. To further identify and classify the variant, fragments of 357-bp partial citrate synthase gene (gltA), 849-bp major surface protein 4 gene (msp4), and 443-bp groESL heat-shock operon gene, were amplified and analyzed. The nucleotide sequences of the partial gltA gene amplified from the rodents were identical to each other, but distinct from previously reported A. phagocytophilum sequences,as were msp4 and groESL. These findings indicate that the newly discovered agent represents a novel A. phagocytophilum variant.
In recent years, machine learning techniques have been widely used in intelligent fault diagnosis field. As a major unsupervised learning technology, cluster analysis plays an important role in fault ...intelligent diagnosis based on machine learning. In rolling bearing fault diagnosis, the traditional spectrum analysis method usually adopts the resonant demodulation technology, but when the inner circle, rolling body or multi-point faults produce composite modulation, it is difficulty to identify the fault type from demodulation spectral lines. According to this, a novel rolling bearing fault diagnosis method based on KFCM (Kernel-based Fuzzy C-Means) cluster analysis is proposed. Through clustering on test data and the known samples, the memberships of test data are obtained. From these, the rolling bearing fault type can be determined. Experimental results show that this method is effective.
The recombinant carboxylesterase PvCarE1-catalyzed hydrolysis product p-nitrophenol (p-NP) can quench the fluorescence of glutathione-stabilized gold nanoclusters (GSH-AuNCs) through internal ...filtration effect, while organophosphate pesticides (OPs) can inhibit the PvCarE1 activity and maintain the fluorescence of GSH-AuNCs.
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•We developed a sensitive fluorescence sensor for rapid organophosphate pesticide (OP) detection.•We utilized glutathione-stabilized gold nanoclusters (GSH-AuNCs) and recombinant carboxylesterase PvCarE1.•The fluorescence signal was quenched by p-nitrophenol (p-NP) without OPs.•OPs inhibit enzymes, thus maintaining GSH-AuNC fluorescence.•The method demonstrated high sensitivity for dichlorvos, trichlorfon, and profenofos.
Considering the severe threat to human health posed by organophosphate pesticides (OPs), reliable and rapid detection methods are urgently needed. In this study, we developed a straightforward and sensitive fluorescence sensor for OP detection. The sensor is based on glutathione-stabilized gold nanoclusters (GSH-AuNCs) and the inhibition of the recombinant carboxylesterase PvCarE1. The fluorescence signal of GSH-AuNCs is efficiently quenched by p-nitrophenol (p-NP) through inner filter effect, which is the product of the recombinant carboxylesterase PvCarE1-catalyzed hydrolysis of p-nitrophenol acetate (p-NPA). In the presence of OPs, the activity of the recombinant carboxylesterase PvCarE1 is inhibited, resulting in decreased p-NP production, and the fluorescence signal of the GSH-AuNCs is maintained. The assay exhibited good sensitivity to dichlorvos, trichlorfon, and profenofos, with detection limits of 0.2 μg/L, 5 μg/L, and 5 μg/L, respectively. In addition, the developed assay was applied to apple sample detection, with recoveries ranging from 84.5 % to 106.3 % and RSDs ranging from 1.3 % to 10.5 %, demonstrating its high potential in monitoring OPs in food.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A basic requirement for quantum information processing is the ability to universally control the state of a single qubit on timescales much shorter than the coherence time. Although ultrafast optical ...control of a single spin has been achieved in quantum dots, scaling up such methods remains a challenge. Here we demonstrate complete control of the quantum-dot charge qubit on the picosecond scale corrected, orders of magnitude faster than the previously measured electrically controlled charge- or spin-based qubits. We observe tunable qubit dynamics in a charge-stability diagram, in a time domain, and in a pulse amplitude space of the driven pulse. The observations are well described by Landau-Zener-Stückelberg interference. These results establish the feasibility of a full set of all-electrical single-qubit operations. Although our experiment is carried out in a solid-state architecture, the technique is independent of the physical encoding of the quantum information and has the potential for wider applications.
Mitochondrial DNA (mtDNA) control region (5′ hypervariable region, 554 bp) sequences from 71 samples of blue sheep (
Pseudois nayaur
Hodgson, 1833) collected from six study localities throughout ...Helan Mountain Nature Reserve in Ningxia province of China were investigated to analyse distribution patterns of genetic variability, elucidate matrilineal structure, and investigate population history. Haplotype diversity (h) among the 71 samples was estimated to be 0.792 ± 0.037, and nucleotide diversity (Π) was relatively low (0.00392 ± 0.00046). A χ
2
contingency analysis of all mtDNA haplotype frequencies revealed that these haplotypes were distributed in a nonrandom fashion among study localities (χ
2
= 86.205, P = 0.092). Additional evidence of matrilineal structure was provided by the finding that a significant amount (9.02%; P < 0.01) of mtDNA variation was partitioned among different localities in the study area. We conclude that blue sheep of Helan Mountain Nature Reserve are structured spatially along matrilines. Pairwise computations of Φ
st
and an AMOVA indicated that some sampling localities are differentiated relative to a random collection of genotypes and reflected differences in the spatial distribution of genetic variation. Isolation-by-distance (IBD) models (Mantel tests) revealed no obvious association between genetic differentiation and geographical distance. These results could be a basis for the development of suitable management strategies for conservation purposes. This work represents the first analysis of blue sheep mitochondrial control region DNA to be performed from a population genetics perspective.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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