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Ammonia emission has attracted considerable attention concerning environmental protection in the world. About 33% of the atmospheric ammonia emission comes from farmland fertilization, so the monitoring of ammonia emissions from farmland is of great significance for controlling atmospheric ammonia pollution. In recent years, tuneable diode laser absorption spectroscopy (TDLAS) has been applied to the measurement of farmland ammonia emission; however, the spectral signal of the open optical path is susceptible to distortion due to temperature, noise, turbulence, etc. Meanwhile, the inversion of the distorted spectrum will result in abnormal concentration values that reduce the detection accuracy. This paper proposes a TDLAS spectral quality evaluation method based on dynamic time warping (DTW) algorithm and support vector data description (SVDD) algorithm. DTW algorithm was used to analyse the similarity between the measured spectrum and the reference spectrum, then SVDD algorithm was used to generate a classification model according to the results of DTW algorithm. DTWSVDD algorithm could effectively avoid obtaining wrong inversion concentration and improve the accuracy of concentration monitoring with identification accuracy of spectral quality reached more than 98%. Applied to the measurement of farmland ammonia emission in Fengqiu, Henan Province, China at the Agricultural Ecological Experiment Station of Chinese Academy of Sciences in November 2021, this method could effectively reduce the dispersion degree of measured concentration trend, as a result, which was better than that of the reported correlation coefficient method. DTW-SVDD algorithm should be of further research value for the application of the analysis of the Big Data of atmospheric composition detection based on grand-based optical remote sensing system. [ABSTRACT FROM AUTHOR]

Undoped and N-doped β-Ga2O3 nanowires (NWs), using NH3 as the dopant source, were successfully fabricated by the CVD method on Si substrates. The microstructure, morphology, element composition and carrier concentration of the samples were characterized by XRD, SEM, TEM, and EDX. The results revealed that well-aligned undoped NWs were perpendicular to the substrates. Comparing with undoped β-Ga2O3 NWs, the morphology of N-doped β-Ga2O3 NWs showed a significant change and they were randomly oriented relative to the substrates. As the NH3 flow was increased, the microstructure of the sample presented a lot of branched-like and trumpet-shaped structures. Simultaneously, a rougher surface has been attained. PL spectrum measurements showed that N-doped β-Ga2O3 NWs had ultraviolet (UV), blue and green emission peaks because of the N-doped process. Furthermore, micro-scale undoped β-Ga2O3/N-doped β-Ga2O3 homojunction structures were fabricated. The I– V property of the fabricated N-doped β-Ga2O3 microwire and β-Ga2O3/N-doped β-Ga2O3 microwire homojunction were compared. I– V results testified that N-doped β-Ga2O3 NWs showed p-type conductivity. [ABSTRACT FROM AUTHOR]

Background Older age, renal dysfunction and low left ventricular ejection fraction are accepted predictors of poor outcome in patients with infective endocarditis (IE). This study aimed to investigate the prognostic significance of the age, creatinine and ejection fraction (ACEF) score in IE. Methods The study involved 1019 IE patients, who were classified into three groups according to the tertiles of ACEF score: low ACEF (<0.6, n  = 379), medium ACEF (0.6–0.8, n  = 259) and high ACEF (>0.8, n  = 381). The ACEF score was calculated as follows: age (years)/ejection fraction (%)+1 (if serum creatinine value was >2 mg/dL). The relationship between ACEF score and adverse events was analyzed. Results In-hospital mortality was 8.2%, which increased with the increase of ACEF score (4.2% vs. 5.0% vs. 14.4% for the low-, medium- and high-ACEF groups, respectively; P  < 0.001). ACEF score had a good discriminative ability for predicting in-hospital death [areas under the curve (AUC), 0.706, P  < 0.001]. The predictive value of ACEF score in surgical treatment was significantly higher than in conservative treatment for predicting in-hospital death (AUC, 0.812 vs. 0.625; P  = 0.001). Multivariable analysis revealed that ACEF score was independently associated with in-hospital mortality (adjusted odds ratio, 2.82; P  < 0.001) and long-term mortality (adjusted hazard ratio, 2.51; P  < 0.001). Conclusion ACEF was an independent predictor for in-hospital and long-term mortality in IE patients, and it could be considered as a useful tool for risk stratification. ACEF score was more suitable for surgical patients in terms of assessing the risk of in-hospital mortality. [ABSTRACT FROM AUTHOR]

Aim: Diabetes is a risk factor in infective endocarditis. However, few studies have focused on the prognostic value of prediabetes in infective endocarditis. This analysis aimed to explore the relationship between prediabetes and outcomes for people with infective endocarditis. Methods: Diabetes and prediabetes definitions were based on the American Diabetes Association 2014 criteria. A total of 866 people who had been consecutively diagnosed with infective endocarditis between January 2009 and July 2015 were included in the analysis. They were divided into three groups: normoglycaemia (n = 469), prediabetes (n = 246) and diabetes (n = 151). Univariate and multivariate analyses were used to identify risk factors for adverse outcomes. Results: Overall in‐hospital mortality was 8.5% (74 of 866), and differed significantly among the normoglycaemia, prediabetes and diabetes groups (3.4%, 12.6% and 17.9%, respectively; P < 0.001). Compared with the normoglycaemia group, the adjusted odds ratio for in‐hospital death was 2.42 [95% confidence interval (CI) 1.11–5.31; P = 0.027) for prediabetes and 3.39 (95% CI 1.48–7.80; P = 0.004) for diabetes. The cumulative long‐term death rate was significantly higher in the prediabetes or diabetes groups than in the normoglycaemia group (log‐rank = 34.82; P < 0.001). Conclusion: In addition to diabetes, prediabetes was also associated with a higher risk of in‐hospital and long‐term mortality among people with infective endocarditis. Therefore, attention should be paid to this population. What's new: Compared with normoglycaemic people, those with infective endocarditis and diabetes demonstrated higher in‐hospital and long‐term mortality.Prediabetes was also a significant risk factor for mortality in people with infective endocarditis.Early identification and better monitoring and treatment is also suggested for people with prediabetes in order to improve their prognoses. [ABSTRACT FROM AUTHOR]

The purpose of this study was to estimate the selenium (Se) requirement of egg-laying ducks based on daily egg production and the selenoprotein glutathione peroxidase (Gpx). Five-hundred and forty laying ducks were divided into six treatments, each containing six replicates of 15 ducks. The birds were caged individually and received a Se-deficient basal diet (0.04 mg/kg) or diets supplemented with 0.08, 0.16, 0.24, 0.32, 0.40 mg/kg Se (as sodium selenite) for 6 months. The experiment consisted of two periods: an early-laying period of 2 months and the peak-laying period of 4 months. Egg production and feed intake were recorded daily. At the end of the experiment, blood samples were drawn for determination of Gpx activity in plasma (Gpx3) and in erythrocytes (Gpx1). Hepatic Gpx1 activity and relative expression of Gpx1 mRNA were also determined. Eggs (n = 6) were sampled for quality determination and Se content at the end of the experiment. The activities of plasma Gpx3, erythrocyte Gpx1 and liver Gpx1 increased in a quadratic manner (P < 0.001) with increasing supplemental Se. The mRNA abundance of hepatic Gpx1 increased linearly (P < 0.001) with dietary Se supplementation. Egg shell thickness was significantly reduced in the ducks fed 0.44 mg Se/kg (P < 0.05), indicating that higher dietary Se tends to compromise egg shell quality. Yolk and albumen contents of Se increased linearly (P < 0.0001) with dietary Se supplementation. Using quadratic broken line models, the Se requirement for daily egg production was 0.18 mg/kg for early-laying ducks and 0.24 mg/kg for peak-laying ducks; for optimal function of Gpx (peak-laying ducks), it was 0.37 mg Se/kg. The data on the function and requirement of minerals is insufficient for egg-laying ducks despite the large-scale laying duck production in Asia. Selenium deficiency leads to low antioxidant enzyme activities in ducks and the selenium requirement for laying ducks was obtained based on the egg production and activities of antioxidant enzymes in this study. Required selenium intake is important for the functions of antioxidant enzyme in production birds and animals. [ABSTRACT FROM AUTHOR]

A novel melting mechanism for single screw extruder with grooved melting zone and barr screw was established. The whole solid-plug, which came from the grooved feed zone, was ruptured and melted mainly by continuously changing the volume of the screw channels and the barrel grooves in the grooved melting zone. A new single screw extruder platform with hydraulic-clamshell type barrels was constructed to investigate the melting performance of different combinations of barrels and screws. The melting model was verified by experiments. Compared with conventional single screw extruder, the melting started earlier and the melting length was shorter in the single screw extruder with grooved melting zone. The melting efficiency was improved by the grooved melting zone and the melting stability was improved by the barr screw. The dimensionless analysis of energy indicates that the heat convection and viscous dissipation are the main melting heat sources for the single screw extruder with grooved melting zone. [ABSTRACT FROM AUTHOR]

To investigate the effects of a synthetic soybean isoflavone (ISF) on growth performance, meat quality, and antioxidation in male broilers, 1,500 birds that were 42 d old were allotted to 5 treatments with 6 replicates per treatment (50 birds per replicate). Birds were fed diets supplemented with 0, 10, 20, 40, or 80 mg of ISF/kg, respectively, for a period of 3 wk ad libitum. The results showed that dietary supplementations with 10 or 20 mg of ISF/kg increased weight gain by 13.6 and 16.2% (P < 0.01) and elevated feed intake by 7.37% (P < 0.05) and 11.2% (P < 0.01), respectively. Addition of 10 mg of ISF/kg decreased feed:gain by 5.5% (P < 0.05). Supple- mentation with 40 mg of ISF/kg in the diet slightly increased water-holding capacity by 17.24% (P <0.1), and the addition of 20 or 40 mg/kg of ISF significantly increased the pH value of meat (P < 0.01), although adding 40 or 80 mg of ISF/kg increased the lightness of meat color (P <0.05). Malondialdehyde production was slightly reduced in plasma of 20 mg of ISF/kg supplemented chickens (P < 0.1) and significantly decreased in breast muscles of 20, 40, or 80 mg of ISF/kg supplemented chickens (P < 0.01). The addition of 40 or 80 mg of ISF/kg significantly increased total antioxidant capability (P < 0.01) and slightly elevated total superoxide dismutase activity (P < 0.1) in plasma of chickens. The dose of 80 mg of ISF/kg slightly improved catalase activity in plasma (P < 0.06). In breast muscle, treatment of birds with 40 or 80 mg of ISF/kg caused an increase of total superoxide dismutase activity by 25.36% (P < 0.05) or 63.93% (P < 0.01). Catalase activity significantly increased by 70.61% by the supplemental ISF at the 40-mg level (P < 0.05). Also, 10, 20, or 40 mg doses of ISF/kg decreased lactic acid production (P < 0.05). The results of this study indicate that dietary ISF could improve growth performance and meat quality by decreasing lipid peroxidation and improving antioxidative status in male broilers. [ABSTRACT FROM AUTHOR]

The new compound (R)-4-phenyl-2-O-[β-d-xylopyranosyl(1 → 6)-β-d-glucopyranosyl]butane (1) and its epimer (2), together with (R)-4-phenyl-2-O-β-d-glucopyranosyl butane (24) and (S)-4-phenyl-2-O-β-d-glucopyranosyl butane (25) were firstly synthesized from 4-phenylbutan-2-one and glucose. The absolute configuration of C-2 for 1 was confirmed as R. Their anti-tumour activities were evaluated. [ABSTRACT FROM AUTHOR]

Three well-known natural diosgenyl glycosides which have the same sugar chains but different sequence, ophipogonin C′, polyphillin C and prosapogenin B, were synthesised by a facile approach. A method using the levulinyl group as a protecting group to selectively mask the C3–OH of diosgenyl 4,6-O-benzylidene-β-d-glucopyranoside is described. [ABSTRACT FROM AUTHOR]

An efficient method for the synthesis of the natural product (+)-(R)-butyl ester of rosmarinic acid (+)-(R)-1 and its enantiomer (−)-(S)-1 has been developed by chemical resolution of its phenyl lactic acid precursors 4 with (−)-menthol. Their antioxidative and anti-tumor activities were evaluated. [ABSTRACT FROM AUTHOR]

Martentoxin is a peptide of 37 amino acid residues purified from the venom of the Chinese scorpion Buthus martensi Karch, which has been demonstrated to be an inhibitor of voltage-dependent sodium channel and voltage-dependent delayed rectifier potassium channel. To elucidate the molecular mechanism of this interaction, the structure of martentoxin was studied by 2D-NMR. The secondary structure of martentoxin consists of a triple-stranded β-sheet connected to a α-helical structure. This helix encompasses 10 residues from Ser11 to Lys20. The three strands of β-sheet probably comprise residues Gly2-Asp5, Q27-N30 and Glu33-Cys36, Cys30-Asn33 with a type I′β turn centered on Asn31-Asn32. The results indicate that martentoxin possesses the conserved β α β β structure of all the potassium channel toxins. [ABSTRACT FROM AUTHOR]

A new peptide, designated as Buthus martensi Karch (BmK) AngM1, with an isoelectric point (pI) of 5.8 was purified and characterized from the venom of Buthus martensi Karch. The molecular mass was calculated as 7040.5 Da from multiple- charged ions by elelctrospray ionization mass spectroscopy (ESI/MS). The complete amino acid sequence of BmK AngM1 of 64 amino acid residues was determined by automatic sequencing of N-terminal part of the native peptide and the fragments of reduced and S-carboxymethylated (RCM)-peptide degraded by Staphylococcus aureaus V8 protease and TPCK(N-p-Tosyl- L-phenylalanine chloromethyl ketone)-treated trypsin. Bioactivity tested using mouse-twisting model showed an evident analgesic effect with 63.0% (P < 0.001) inhibition efficiency at the dose of 0.8 mg/kg, but the LD50 was larger than 50 mg/kg. Electrophysiological studies showed that BmK AngM1 at the concentration of 1 μM obviously inhibit voltage-dependent Na+ current (INa) and voltage-dependent delayed rectifier K+ current (IK) but had no effects on transient K+ current. [ABSTRACT FROM AUTHOR]

A new peptide named Martentoxin I and an analogue Martentoxin were purified and characterized from the venom of Buthus martensi Karch. Martentoxin I consisted of 36 amino acid residues with molecular mass as 3908.0 Da determined by matrix-assisted laser desorption ionization time-of-flight-MS. The amino acid sequence was determined as GLIDVKCFASSECWTACKKVTGSGQGKCQNNQCRCY by Edman degradation. Martentoxin consisted of 37 amino acid residues with a molecular mass as 4055.3 Da and it showed highly sequence identity to Martentoxin I as FGLIDVKCFASSECWTACKKVTGSGQGKCQNNQCRCY. Estimation from circular dichroism spectra indicated Martentoxin I owned 18.0% α-helix, 53.0% β-sheet structure and 3.9% turn while Martentoxin contained 13.3% α-helix, 64.3% β-sheet structure and 1.1% turn. The toxicity assay showed both peptides had no toxic effects on mice up to the dose of 10 mg/kg. Electrophysiological studies showed that Martentoxin I and Martentoxin at the concentration of 1 μ m significantly inhibited voltage-dependent Na+ current (INa) and voltage-dependent delayed rectifier K+ current (IK) but had no effects on transient K+ current (IA). Both interactions with Na+ and K+ channels were irreversible. [ABSTRACT FROM AUTHOR]