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The fastener system is an essential component of the high-speed ballastless track system. A detailed analysis for the effect of fastener looseness on the vertical dynamic response of the vehicle–track coupling system is conducted from the time domain, frequency domain and time–frequency domain in this paper. A fine fastener system model is employed, which includes two spring rods and one rail pad. The preloaded force is proposed to simulate the defect of the fastener, and a looseness coefficient is defined to represent the loose degree of the fastener. First, three fastener system models are introduced into the model, respectively, and the difference in the vehicle–track dynamic is analyzed and compared. The results show that the proposed model is more consistent with the real situation and more suitable to simulate fastener defects. Then, the detailed analysis of vehicle and track dynamic responses is explored in the case of different degrees of loose fasteners and the case of completely loose fasteners. According to the simulation results, there is little impact on the dynamic response of the vehicle–track system when the looseness coefficient is less than 0.9. When the fasteners are completely loosened, the dynamic response of the wheelset and the rail significantly increases. The vibration responses of rail and wheelset enhance with the increase of the number of the completely loose fastener. The loose fasteners affect the low-frequency part of the wheelset vibration response and the high-frequency part of the rail vibration response. Finally, a time–frequency analysis method is used to analyze the system vibration response under the combined effect of the completely loose fastener and the track irregularity. The track irregularity still dominates the excitation of the system, and the vibration response of the wheelset and the rail is more sensitive to the fastener defect at low speed.

CTX-M extended spectrum beta-lactamase-producing

We reported that Shroom3 knockdown, via Fyn inhibition, induced albuminuria with foot process effacement (FPE) without glomerulosclerosis (FSGS) or podocytopenia. Interestingly, knockdown mice had reduced podocyte volumes. Human minimal change disease, where podocyte Fyn inactivation was reported, also showed lower glomerular volumes than FSGS. We hypothesized that lower glomerular volume prevented the progression to podocytopenia. To test this hypothesis, we utilized unilateral- and 5/6th nephrectomy models in Shroom3 knockdown mice. Knockdown mice exhibited lower glomerular volume, and less glomerular and podocyte hypertrophy after nephrectomy. FYN-knockdown podocytes had similar reductions in podocyte volume, implying Fyn was downstream of Shroom3. Using SHROOM3- or FYN-knockdown, we confirmed reduced podocyte protein content, along with significantly increased phosphorylated AMP-kinase, a negative regulator of anabolism. AMP-Kinase activation resulted from increased cytoplasmic redistribution of LKB1 in podocytes. Inhibition of AMP-Kinase abolished the reduction in glomerular volume and induced podocytopenia in mice with FPE, suggesting a protective role for AMP-Kinase activation. In agreement with this, treatment of glomerular injury models with AMP-Kinase activators restricted glomerular volume, podocytopenia and progression to FSGS. In summary, we demonstrate the important role of AMP-Kinase in glomerular volume regulation and podocyte survival. Our data suggest that AMP-Kinase activation adaptively regulates glomerular volume to prevent podocytopenia in the context of podocyte injury.

Chicken is the most widely consumed meat product worldwide and is a high-quality source of protein for humans. The skeletal muscle, which accounts for the majority of chicken products and contains the most valuable components, is tightly correlated to meat product yield and quality. In domestic chickens, skeletal muscle growth is regulated by a complex network of molecules that includes some non-coding RNAs (ncRNAs). As a regulator of muscle growth and development, ncRNAs play a significant function in the development of skeletal muscle in domestic chickens. Recent advances in sequencing technology have contributed to the identification and characterization of more ncRNAs (mainly microRNAs (miRNAs), long non-coding RNAs (LncRNAs), and circular RNAs (CircRNAs)) involved in the development of domestic chicken skeletal muscle, where they are widely involved in proliferation, differentiation, fusion, and apoptosis of myoblasts and satellite cells, and the specification of muscle fiber type. In this review, we summarize the ncRNAs involved in the skeletal muscle growth and development of domestic chickens and discuss the potential limitations and challenges. It will provide a theoretical foundation for future comprehensive studies on ncRNA participation in the regulation of skeletal muscle growth and development in domestic chickens.

Objective We investigated the level of physician trust in China and how it is influenced by various demographic factors. MethodsWe surveyed 12 public hospitals from which inpatients were randomly selected using hospitalization ID and outpatients were selected using census sampling to participate in the interview. Trust in physicians was measured using the Chinese version of Wake Forest Physician Trust Scale. Mixed-effects and logistic models were employed to study correlates of trust. ResultsThe distribution of scale mean was left skewed, which implied a subpopulation bearing low levels of trust towards physicians. Respondents who were male, young, outpatients, unsatisfied with their life status, had high levels of education and income, and paid less attention to their health were prone to be less satisfied with their physicians. ConclusionsThe level of physician trust in China is lower compared to studies in western countries. We also found demographic factors related with significantly lower physician trust, which may help policymakers identify potential target subpopulations and be more specific with their efforts to improve patient-physician relationships.

Objectives To evaluate disparity in service quality between second- and third-tier hospitals and explore factors that affect patients' perception of service quality in China. Design Cross sectional study. Setting Twelve hospitals in China. Participants 5714 patients. Intervention None. Main Outcome Measure Total score of the SERVQUAL scale and each of its five dimensions. Results Patients from third-tier hospitals rated significantly higher scores overall and in all the five dimensions of the SERVQUAL scale. Those with lower education, urban residents and those who had higher degree of life satisfaction and attention paid to health perceived higher service quality. Inpatients perceived higher service quality compared with outpatients. Conclusion We found a significant gap in patient's perceived service quality between second- and third-tier hospitals in China. A variety of demographic and personality factors were found to significantly influence patient's perceived service quality.

A novel magnetic solid-phase extraction (MSPE) material (Fe3O4@SiO2-NH2-G2) had been prepared and employed for adsorption and analysis of seven quaternary ammonium compounds (QACs) in infant fruit and vegetable products coupled with high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). In this paper, Fe3O4@SiO2-NH2-G2 was synthesized based on Fe3O4@SiO2-NH2 and dendrimer (G2) consisting of cyanuric chloride and imidazole. The morphology, configuration and magnetic behavior of the magnetic material were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectrometry (FT-IR), X-ray diffraction (XRD), and vibrating sample magnetometer (VSM). Critical parameters affecting extraction efficiency, such as the adsorbent amount, sample pH, extraction time, the type of eluent, and desorption time, were optimized. The proposed method provided good linearity with the correlation coefficients (R2) of 0.9992-0.9999, low limits of detection (LODs) (0.05-0.50 μg kg-1) and limits of quantitation (LOQs) (0.20-2.00 μg kg-1). The satisfactory method recoveries in three spiked infant fruit and vegetable products samples were between 80.12% and 101.35% with the relative standard deviations (RSDs) less than 12.04%. In summary, the established method was an effective sample preparation method and showed good prospect for the analysis of QACs in complex matrices.

Intelligent fault diagnosis algorithm for rolling bearings has received increasing attention. However, in actual industrial environments, most rolling bearings work under severe working conditions of variable speed and strong noise, which makes the performance of many intelligent fault diagnosis methods deteriorate sharply. In this regard, this paper proposes a new intelligent diagnosis algorithm for rolling bearing faults based on a residual dilated pyramid network and full convolutional denoising autoencoder (RDPN-FCDAE). First, a continuous wavelet transform (CWT) is used to convert original vibration signals into time-frequency images. Secondly, a deep two-stage RDPN-FCDAE model is constructed, which is divided into three parts: encoding network, decoding network and classification network. In order to obtain efficient expression of data denoising feature of encoding network, time-frequency images are first input into the encoding-decoding network for unsupervised pre-training. Then pre-trained coding network and classification network are combined into residual dilated pyramid full convolutional network (RDPFCN) for parameter fine-tuning and testing. The proposed method is applied to bearing vibration datasets of test rig with different speeds and noise modes. Compared with representative machine learning and deep learning method, the results show that the algorithm proposed is superior to other methods in diagnostic accuracy, noise robustness and feature segmentation ability.

Background DELLAs play key roles in plant gibberellin signaling pathways and are generally important in plant development and growth. However, DELLAs in many plant taxa have not yet been systematically analyzed. Results In our study, we searched for DELLA genes across 58 green plant genomes and found 181 DELLAs. Structure analysis showed some DELLA domains do not contain “D-E-L-L-A” sequences and instead contain similar domains, including DGLLA and DSLLH domains. “VHYNP” motifs in plant DELLAs comprise 23 types of sequences, while some DELLAs did not contain GRAS domains. In grape, we found that the DELLA protein GSVIVT01015465001 contains an F-box domain, while apple DELLA proteins MDP0000220512 and MDP0000403162 contain a WW domain and a BCIP domain, respectively. These DELLAs can be divided into 22 homologous groups and 17 orthologous groups, and 35 paralogous genes were identified. In total, 35 positively selected genes (PSGs) and 121 negatively selected genes (NSGs) were found among DELLAs based on selective pressure analysis, with an average Ks of NSGs that was significantly higher than that of PSGs (P Ka values. We also found some paralogous groups with ω values exceeding 1 that differed in their motifs. Conclusions This study provides helpful insights into the evolution of DELLA genes and offers exciting opportunities for the investigation of DELLA functions in different plants.

Molybdenum (Mo) is a component of the Mo cofactor (Moco) of nitrate reductase (NR) and is therefore essential for nitrate metabolism. However, little is known about Mo deficiency phenotypes or about how physiological and molecular mechanisms of Mo uptake and transport influence nitrate uptake and utilization in strawberry. Here, we used physiological and cytological techniques to identify Mo deficiency phenotypes in strawberry. Seedlings cultured with MoO4 2- grew well and exhibited normal microstructure and ultrastructure of leaves and roots. By contrast, seedlings cultivated under Mo-deficient conditions showed yellow leaf blades and ultrastructural changes such as irregular chloroplasts and unclear membrane structures that were similar to the symptoms of nitrogen deficiency. We cloned and analyzed a putative molybdate transporter, FaMOT1, which may encode a molybdate transporter involved in the uptake and translocation of molybdate. Interestingly, the addition of the molybdate analog tungstate led to lower tissue Mo concentrations, reduced the translocation of Mo from roots to shoots, and increased the plants' sensitivity to Mo deficiency. Seedlings cultivated with MoO4 2- altered expression of genes in Moco biosynthesis. As expected, NR activity was higher under sufficient MoO4 2- levels. Furthermore, seedlings grown on Mo-deficient medium exhibited decreased 15NO3 - translocation and lower 15NO3 - use efficiency. These findings represent an important step towards understanding how molybdate transport, concentration, and deficiency symptoms influence nitrate uptake and utilization in strawberry.

Background LncRNAs are key regulators in cancer. The current study explored the role of lncRNA LINC00261 (LINC00261) in lung cancer (LC). Methods Expression of LINC00261 in LC tissues and cells was determined by quantitative real-time polymerase chain reaction (qRT-PCR). Pearson’s Chi square test and Kaplan–Meier analysis were performed to evaluate the correlations between LINC00261 expression and clinical characteristics, and overall survival time. A549 and SPC-A1 cells were transfected with LINC00261 overexpression plasmid, cell viability, cell number, and apoptosis were detected by CCK-8 assay, colony formation, and flow cytometry. Moreover, wound-healing and transwell assay were performed to detect cell metastasis and invasion. Expressions of proteins related to cell proliferation and metastasis were determined by Western blot. Xenograft was constructed, and tumor size and weight were measured and the effects of LINC00261 overexpression on tumor growth were detected. Bioinformatics analysis, dual-luciferase reporter assay, qRT-PCR, correlation analysis, and functional rescue experiments were conducted on clinical cases and LC cells to explore the molecular mechanism of LINC00261 in LC. Results In LC, LINC00261 expression was down-regulated, and was associated with more advanced TNM stage, metastasis and a shorter survival time. LINC00261 overexpression inhibited the growth and metastasis of LC cells in vitro and tumor growth in vivo. Furthermore, miR-1269a directly interacted with LINC00261 and FOXO1. The expressions of miR-1269a and FOXO1 were dysregulated by LINC00261 in LC. Additionally, miR-1269a promoted the progression of LC through targeting FOXO1. Conclusions Down-regulation of LINC00261 expression has a prognostic value in LC, and overexpression LINC00261 inhibits LC progression via targeting miR-1269a/FOXO1 axis.

As a polymicrobial disease, sour rot decreases grape berry yield and wine quality. The diversity of microbial communities in sour rot-affected grapes depends on the cultivation site, but the microbes responsible for this disease in eastern coastal China, has not been reported. To identify the microbes that cause sour grape rot in this important grape-producing region, the diversity and abundance of bacteria and fungi were assessed by metagenomic analysis and cultivation-dependent techniques. A total of 15 bacteria and 10 fungi were isolated from sour rot-affected grapes. High-throughput sequencing of PCR-amplicons generated from diseased grapes revealed 1343 OTUs of bacteria and 1038 OTUs of fungi. Proteobacteria and Firmicutes were dominant phyla among the 19 bacterial phyla identified. Ascomycota was the dominant fungal phylum and the fungi Issatchenkia terricola, Colletotrichum viniferum, Hanseniaspora vineae, Saprochaete gigas, and Candida diversa represented the vast majority ofmicrobial species associated with sour rot-affected grapes. An in vitro spoilage assay confirmed that four of the isolated bacteria strains (two Cronobacter species, Serratia marcescens and Lysinibacillus fusiformis) and five of the isolated fungi strains (three Aspergillus species, Alternaria tenuissima, and Fusarium proliferatum) spoiled grapes. These microorganisms, which appear responsible for spoiling grapes in eastern China, appear closely related to microbes that cause this plant disease around the world.

Wheels are essential parts of railway freight cars, thus scheduling reasonable maintenance time can improve transportation efficiency and reduce maintenance cost, while ensuring operation safety. In this paper, an opportunity-centralized maintenance strategy is presented based on Remaining Useful Life (RUL) prediction. First, a degradation model of wheel tread wear is constructed with non-linear Wiener process, while model parameters are estimated using Gibbs sampling algorithm and wheel degradation data. With the updated model, real-time RUL of wheels are predicted. Next, an opportunity-centralized maintenance strategy based on the different failure time of all the wheels is proposed in order to make a reasonable maintenance schedule, which is difficult to set due to the significantly varying individual degradation processes on different wheels. The decision of maintenance strategy is transformed into a multi-objective optimization problem, in which maintenance times and cost are the optimization objectives. A cost function reflecting the wheel operation cost is constructed, while the average cost per time unit is defined as an optimization objective. Furthermore, NSGA-II algorithm is employed to solve the optimization problem. And a semi-randomized method is proposed to increase the diversity of the initial population. Finally, the effectiveness of the presented algorithm is verified using 500-days on-line monitoring data of wheel tread wear in a 54 fixed group of railway freight cars. The proposed method can be applied to maintenance strategy formulation of any equipment with many similar parts.

The wheel-rail dynamic responses under the initiation of rail corrugation are aggravating obviously, which may lead to the security issue and discomfort of a train with high-speed. In this work, firstly, the vehicle-track vertical coupling system is established to acquire the wheelset dynamic response of the vehicle under the action of rail corrugation and track irregularity. Correspondingly, the characteristic parameters of the wheelset vibration acceleration signals were selected using different signal processing methods. Next, the detection of rail corrugation and the corrugation depth classification were implemented using the support vector machine and particle swarm optimization algorithm. In the end, an optimal algorithm based on wavelet packet and bispectrum was proposed for the comparison of different signal processing algorithms. Features, such as normalized wavelet packet energy, energy entropy, bispectrum entropy, diagonal slice peak and normalized frequency were extracted. The detection accuracy of normal rail and rail corrugation based on the proposed algorithm can be up to 100% and the classification accuracy can be up to 99% under the corrugation depth of 0mm, 0.01mm~0.03mm, 0.04mm~0.07mm and 0.08mm~0.1mm, which performs better than EMD, WPT or bispectrum.

Rotor parts fly-off of large rotating machines could lead to high maintenance costs and accidents with disastrous consequences. The earlier fault features extraction and prognosis of unit breakdown are relatively difficult and has become a worldwide challenge. A rough-fine-scale prognosis (RFSP) model of compressors and steam-turbines fault is proposed in this paper. Firstly, a roughly classifying method for the health stage of rotating units based on Gradient Boosting Decision Tree is performed. The Peak-Difference-Vectors of multi-sensor vibration signals in time and frequency domain are extracted as fault features. Secondly, for the failure development processes, which signals have similar features, the fault severity index is built to quantify the trend of failure and distinguish different stages on fine-scale. The validity of the proposed method is verified with 5 processes for each of 9 large rotating units in real industrial scenarios. The best model achieves 99.5% accuracy for rough classifying health stages. Besides, the fine-scale prognosis achieves 100% accuracy for the determination of malfunctioning machinery and the division of health stages. This work highlights the promise of capturing the early symptom of rotor faults and predicting the failure of the rotor component in terms of few fault cases, changeable working conditions and interference of other unknown faults.

Many freight trains for special lines have in common the characteristics of a fixed group. Centralized Condition-Based Maintenance (CCBM) of key components, on the same freight train, can reduce maintenance costs and enhance transportation efficiency. To this end, an optimization algorithm based on the nonlinear Wiener process is proposed, for the prediction of the train wheels Remaining Useful Life (RUL) and the centralized maintenance timing. First, Hodrick–Prescott (HP) filtering algorithm is employed to process the raw monitoring data of wheel tread wear, extracting its trend components. Then, a nonlinear Wiener process model is constructed. Model parameters are calculated with a maximum likelihood estimation and the general deterioration parameters of wheel tread wear are obtained. Then, the updating algorithm for the drift coefficient is deduced using Bayesian formula. The online updating of the model is realized, based on individual wheel monitoring data, while a probability density function of individual wheel RUL is obtained. A prediction method of RUL for centralized maintenance is proposed, based on two set thresholds: “maintenance limit” and “the ratio of limit-arriving.” Meanwhile, a CCBM timing prediction algorithm is proposed, based on the expectation distribution of individual wheel RUL. Finally, the model is validated using a 500-day online monitoring data on a fixed group, consisting of 54 freight train cars. The validation result shows that the model can predict the wheels RUL of the train for CCBM. The proposed method can be used to predict the maintenance timing when there is a large number of components under the same working conditions and following the same path of degradation.

A novel, simple and efficient chemiluminescence system has been developed for the determination of monoamine neurotransmitters and metabolites. By using the Ag (III)-luminol chemiluminescence system as a detector, a high performance liquid chromatography chemiluminescence method (HPLC-CL) was established and used to detect seven monoamine neurotransmitters. Under the optimized conditions, the detection limits (3S/N) of epinephrine (E), levodopa ( l -DOPA), dopamine (DA), serotonin (5-HT), 3-methoxy-4-hydroxyphenylglycol (MHPG), 3,4-dihydroxyphenylacetic acid (DOPAC) and 5-hydroxypentylacetic acid (5-HIAA) were 20.0 μg dm−3,15.0 μg dm−3, 15.0 μg dm−3, 8.0 μg dm−3, 2.0 μg dm−3, 2.0 μg dm−3 and 3.0 μg dm−3, respectively. Moreover, they were well within the linear range of 50–1000 μg dm−3, 50–1000 μg dm−3, 50–1000 μg dm−3, 25–1000 μg dm−3, 5–25 μg dm−3, 5–25 μg dm−3 and 10–30 μg dm−3, respectively. The average recovery varied between 84.82% and 110.4%. The method has the attributes of simplicity, high sensitivity, and high efficiency. The sensitization and inhibition mechanisms for luminol-[Ag(HIO6)2]5–- analytes CL system were proposed by CL spectra and free-radical capture experiment.

Disengagement of emulsified cement asphalt mortar will increase the dynamic action between the vehicle and the track; as a consequence, the rate of cement asphalt mortar disengagement will increase further. This is a serious threat for the safe operation of high-speed railways and the service life of rail equipment. In this study, a vertical coupled model for the vehicle–China Railway Track System II-type slab track with cement asphalt disengagement was established. The cement asphalt mortar was divided into units in order to simulate the arbitrary length of disengagement. Under different conditions, the effects of the cement asphalt mortar disengagement on the dynamic characteristics of the coupled model were analyzed. The results show that when the length of disengagement exceeds 0.65 m under the condition of horizontal complete disengagement, the dynamic responses of the system increase much sharply than the condition of horizontal partly disengagement. Because of the difficulty in identifying defects in the track substructure, a novel method was proposed to rapidly identify the cement asphalt mortar disengagement based on the dynamic responses of the coupled system and particle swarm optimization–support vector machines. The feature vectors were extracted from the acceleration of the wheelset, which were used as training samples in support vector machines. The classification results show that the recognition algorithm based on the acceleration of the wheelset and support vector machines is effective. The location of the track plate with the cement asphalt mortar disengagement at lengths of 0.65 m, 1.3 m, and 1.95 m can be identified with an acceptable accuracy. The robustness of the proposed algorithm under different vehicle speeds, track spectrums, and signal–noise ratios was verified. Recognition of defects in the track substructure using sensors mounted on in-service vehicles has the potential to provide a valuable tool for ensuring the safe operation of railways and for developing a maintenance plan.

This study examined effects of the treatment-before-deposit policy on Chinese patients' trust in physicians and perceived service quality. This study included 3313 patients recruited from 12 hospitals in China. The research team used cross-sectional survey to examine Chinese patients' experience with the treatment-before-deposit policy, perceived service quality, and trust in their physicians. Using mediation analysis, we estimated direct and indirect effects of the treatment-before-deposit policy on patients' perceived service quality and trust in their physicians. Patients who benefitted from the treatment-before-deposit policy reported greater service quality and higher trust in their physicians. The impacts of whether patients benefitted from the policy on trust in physicians were fully mediated by perceived service quality with statistically significant indirect effect. The results support the hypothesis that the treatment-before-deposit policy improves patients' perceived service quality and trust in physicians.

Oxidations of hydrazine (H2NNH2) and substituted hydrazines (t-C4H9HNNH2 and c-C6H11HNNH2) by [IrCl6]2− are found to obey overall second-order kinetics: −d[IrCl62−]/dt = k′[RHNNH2]tot[IrCl62−], where k′ pertains to the observed second-order rate constants and [RHNNH2]tot stands for the total concentration of hydrazines. The k′ versus pH profiles have been established over a pH range from 3 to 10. Rapid scan spectra recorded for the reaction courses indicate that there are no fast substitutions on [IrCl6]2− and/or strong associations between [IrCl6]2− and hydrazines during the reactions. The determined ratios of Δ[Ir(IV)]/Δ[RHNNH2]tot clearly endow a 4:1 stoichiometry for all the hydrazines studied. The oxidation product has been identified by NMR spectroscopy in the case of t-C4H9HNNH2. The proposed reaction mechanisms involve parallel attack of [IrCl6]2− on RHNNH3+ and RHNNH2, forming the rate-determining steps and producing hydrazyl free radicals; these are followed by several fast reactions. Rate equations have been derived, and the rate constants of the rate-determining steps at 25.0 °C and 1.0 M ionic strength have been calculated. It is demonstrated that our kinetic analysis is a good approach for determination of the pKa values of hydrazines. Monoalkyl substitutions on hydrazine enhance the reactivity of substituted hydrazines significantly, but the reactivity has no correlation with the pKa values. All the kinetic and spectral attributes bestow that an outer-sphere electron transfer takes place in the rate-determining steps. Moreover, all the kinetic and mechanistic discrepancies for the hydrazine-[IrCl6]2− reaction remained in literature have been clarified in the present work.

Recent advancements in neuroimaging have made new ways of breaking down the dynamic interplay of genes and environmental influences, which affect the structure of accessible brain development. The impact on language abilities and verbal short-term memory of pre-school children from socioeconomic status (SES). Children from lower SES show less linguistic abilities and communication skills compared to higher SES children. The challenges of children's vocabulary brain development difference between lower and higher SES continues sometimes grows with age. Therefore this paper, machine learning assisted vocabulary development framework (MLVDF), has proposed a multimodal assessment of young children's brains' intellectual ability and capabilities. The proposed methodology is focused on the estimation and comparison with more developed strategies of nonverbal abilities using similar video interfaces. Machine learning technologies are used to determine a minimum number of variables capable of predicting particular children's cognitive skills. Thus, the findings highlight the complex effect of verbal and cognitive abilities on children's language and life experience. The results are obtained by the analysis of SES in Children's brain development as Cognitive skills ratio is 86.6%, Verbal abilities ratio is 87.12%, Children's brain capability ratio is 87.6%, Increasing the memory ratio is 83.5%, Learning attitude ratio is 93.8%, Reduce the effect of socioeconomic status ratio is 84.25%, Reading efficiency ratio is 87.6%.

Social and emotional learning (SEL) services from schools will help achieve good results for pupils. Nevertheless, these systems often lose efficiency and struggle to achieve the desired positive results. The ongoing study assesses the effect of application consistency on accomplishing a 12–19-year-old SEL-based school-based program. The research looks at the impact of various aspects of the project, such as dosages, compliance, customer satisfaction, and respondent response. The study gathered data from 35 school systems over three times using randomized controlled layouts and contrasted this data between four components: high adoption, low compliance, and regulation. School-based prevention through social and emotional learning (SP-SML) is proposed. The research compiled results from 35 school systems. Finite mixture models lengthwise determined the correlation between deployment evidence and formations information. The results showed that only the high-implementation community (declined emotional repression; decreased coping with preventative problems; improved coping with welfare protection; lower levels of depression and depressed side effects) had experienced the system's beneficial effects. The analysis of the implementing proportions showed a significant impact on all the design cues only by a commitment to performance. This research underlines the value of good quality execution as practical results and promotes the requirement for a multi-dimensional assessment of their implementations. The proposed method's outcomes in result analysis are: program effect size ratio is 85.6%, emotional intelligence score ratios are 88.3%, and efficiency analysis overall ratio is 90.4%.

Highlights • Ultrasound increases the DH of gelatin and antioxidant properties of hydrolysate. • Ultrasound facilitates the unfolding of protein structure. • Ultrasound accelerates the thermal degradation of the protein. • Ultrasound changes the morphology and interface characteristics of gelatin particles., This study primarily explored the internal mechanism underlying the ultrasonication-induced release of antioxidant peptides. An oxhide gelatin solution was treated ultrasonically (power = 200, 300, and 400 W), followed by enzymatic hydrolysis and structural and morphological analysis. The results showed that ultrasonication increased not only the degree of hydrolysis (DH) and protein recovery rate of the oxhide gelatin but also the ABTS radical scavenging, DPPH radical scavenging, ferrous chelating, and ferric reducing activities of its hydrolysate. The oxhide gelatin hydrolysate treated with 300-W ultrasonication had the maximum antioxidant activities. Ultrasonication inhibited hydrogen bond formation, reduced the crosslinking between collagen molecules, transformed part of the folded structure into a helical structure, and lowered the thermal stability of collagen molecules. The micromorphological analysis revealed that ultrasonication caused the gelatin surface to become loose and develop cracks, and as the power of the ultrasonication increased, the repetition interval distance (dÅ) also increased. Moreover, ultrasonication improved the solubilization, surface hydrophobicity, and interface characteristics and increased the content of basic and aromatic amino acids in the hydrolysate. In conclusion, ultrasonication modifies the protein structure, which increases the enzyme’s accessibility to the peptide bonds and further enhances antioxidant peptide release. These findings provide new insights into the application of ultrasonication in the release of antioxidant peptides.

Taint in grapes and wine following vineyard exposure to bushfire smoke continues to challenge the financial viability of grape and wine producers worldwide. In response, researchers are studying the chemical, sensory and physiological consequences of grapevine smoke exposure. However, studies involving winemaking trials are often limited by the availability of suitable quantities of smoke-affected grapes, either from vineyards exposed to smoke or from field trials involving the application of smoke to grapevines. This study compared the accumulation of volatile phenol glycosides (as compositional markers of smoke taint) in Viognier and Cabernet Sauvignon grapes exposed to smoke pre- vs. post-harvest, and found post-harvest smoke exposure of fruit gave similar levels of volatile phenol glycosides to fruit exposed to smoke pre-harvest. Furthermore, wines made from smoke-affected fruit contained similar levels of smoke-derived volatile phenols and their glycosides, irrespective of whether smoke exposure occurred pre- vs. post-harvest. Post-harvest smoke exposure therefore provides a valid approach to generating smoke-affected grapes in the quantities needed for winemaking trials and/or trials that employ both chemical and sensory analysis of wine.

5-hydroxytryptamine (5-HT) and its derivatives are endogenously active substances involved in multiple physiological and pathological processes. A novel method of detetermining 5-hydroxyindole ethanol (5-HTOL), 5-hydroxyindole acetic acid (5-HIAA), 5-hydroxytryptophan (5-HTP) and 5-HT in amniotic fluid by gas chromatography-mass spectrometry (GC-MS) was established based on a modified method of derivatization by silanization, in combination with solid-phase extraction pretreatment. Good linearity was achieved in the tested calibration range. The limits of detection (LOD) were 0.05, 0.08, 0.56, 0.43μg/L for 5-HTOL, 5-HIAA, 5-HTP and 5-HT, respectively. Accuracy (92.4-103.3) and precision (RSD5.4%) for all analytes was also determined. Then the method was used to analyze samples of amniotic fluid from 12 patients carrying foetuses with trisomy 21 and 12 healthy controls. Compared with normal fetuses, the levels of 5-HTOL, 5-HTP and 5-HT in the amniotic fluid were significantly altered in the fetuses with trisomy 21 (P0.01); the level of 5-HIAA showed no significant difference between the two groups (P0.05). This is a rapid, sensitive and reliable method for the determination of 5-HTOL, 5-HIAA, 5-HTP and 5-HT, and the study provide both potential trisomy 21 markers and elucidation of the physiological and pathological roles of 5-HT.

Pt(IV) anticancer active complexes are commonly regarded as prodrugs, and the reduction of the prodrugs to their Pt(II) analogs is the activation process. The reduction of a cisplatin prodrug cis-[Pt(NH3)2Cl4] and a carboplatin prodrug cis,trans-[Pt(cbdca)(NH3)2Cl2] by dl-homocysteine (Hcy) has been investigated kinetically in a wide pH range in this work. The reduction process follows overall second-order kinetics: −d[Pt(IV)]/dt = k′[Hcy]tot[Pt(IV)], where [Hcy]tot stands for the total concentration of Hcy and k′ pertains to the observed second-order rate constants. The k′ versus pH profiles have been established for both prodrugs. Spectrohotometric titrations reveal a stoichiometry of Δ[Pt(IV)]:Δ[Hcy]tot = 1:2; homocystine is identified as the major oxidation product of Hcy by high-resolution mass spectrometry. A reaction mechanism has been proposed, which involves all the four protolysis species of Hcy attacking the Pt(IV) prodrugs in parallel. Moreover, these parallel attacks are the rate-determining steps, resulting in a Cl+ transfer from the Pt(IV) prodrugs to the attacking sulfur atom. Rate constants of the rate-determining steps have been derived, indicating that the two prodrugs are reduced with a very similar rate in spite of the difference between the coordination ligands in their equatorial positions. The reactivity analysis in the case of cis,trans-[Pt(cbdca)(NH3)2Cl2] unravels that one species of Hcy (form III) is almost exclusively responsible for the reductions at the physiological pH (7.4), although it is existing only 5.2% of the total Hcy. On the other hand, the dominant existing form II of Hcy virtually does not make a contribution to the overall reactivity at pH 7.4.

Hydrogen sulfide (H2S) plays major functional and structural roles in diverse physiological functions and the pathogenesis of a variety of disorders in biological matrices. The significance of H2S has prompted the development of sensitive and selective methods to determine its concentration in biological samples. The fluorescent reagent monobromobimane (MBB) has been widely used to measure various thiol-containing species through alkylation. MBB may prevent the oxidation of sulfide and the reaction of sulfide with several different species (such as superoxide radicals, hydrogen peroxide and peroxynitrite). An isomers of MBB, 3-(bromomethyl)-2, 6, 7-trimethyl-1H, 5H-pyrazolo [1,2-a] pyrazole-1, 5-dione (MMB), is cheaper than MBB and its use in the analysis of H2S has not previously been reported. In the present study, we compared the derivatization reactions of hydrogen sulfide with MMB and MBB and developed a sensitive method to quantify H2S in blood. In our method, H2S was incubated in the dark with excess MMB in 0.1M Tris-HCl buffer (pH 10.1) at 50°C for 120min. 50μL aliquots of the derivatized product were analyzed using HPLC system with gradient elution of 0.1% (v/v) formic acid-acetonitrile. The limit of detection for the derivatized product was 0.03nmol/mL. The derivatization reaction was suitable for detecting low concentrations of H2S. The derivate product is stable over time, permitting batch storage and analysis.

Ascorbic acid (AA), uric acid (UA) and glutathione (GSH) are the most important water-soluble antioxidants. The concentrations of GSH and glutathione disulfide (GSSG) and their molar ratio are the indicators of oxidative stress. Little is known about the contents of UA, GSH and GSSG in human milk; a reliable and sensitive method to monitor the concentrations of the four compounds simultaneously in human milk is of critical importance. A new method for separation and quantification of these water-soluble antioxidants by HPLC coupled with Ag(III) chemiluminescence detector has been developed in this work with better recoveries. The antioxidants contents were determined in different times of lactation utilizing this method. The results show that the levels of AA, UA, GSH and GSH/GSSG of human colostrum are significantly higher than those of mature milk (P

Bisphenol A (BPA), as one of the environmental endocrine disruptors, is extensively existing and threatening to human health. To evaluate the environmental exposure level and protect human from the hazard of BPA, a precise and sensitive method is established. In this work, Graphene@ Fe3O4 (G@Fe3O4) is prepared by chemical coprecipitation method as magnetic dispersion solid phase extraction (MDSPE) material. The rapid and specific detection method of BPA is carried out by high-performance liquid chromatography (HPLC). Properties of G@Fe3O4 are identified by the fourier infrared spectrum and scanning electron microscopy. Conditions of solid phase extraction are optimized. Under the optimal extraction conditions, G@Fe3O4 has perfect enrichment effect on BPA. There is a good linear relationship in the range of 5.0~1000.0 μg/L with the correlation coefficient of 0.9997. The detection limit is 0.1 μg/L. This method is applied to water samples successfully, and recoveries of BPA are between 88.19% and 99.56% (RSDs

Purpose: The pathological mechanisms of constant exotropia (XT) are still not understood. This study aimed to critically investigate whether patients with XT express neuronal activity changes after the critical period of visual development and further explore how these alterations are associated with behavioral performance.Materials and methods: Fourteen patients with XT and 16 healthy controls (HCs) underwent resting-state functional magnetic resonance imaging (fMRI). The regional homogeneity (ReHo) method was used to evaluate spontaneous brain activities. The association between significantly altered mean ReHo values and behavioral performance was assessed using Pearson's correlation analysis.Results: Compared with HCs, the right secondary visual cortex (V2) in patients with XT exhibited increased ReHo values, whereas the left Brodmann area 47 (BA47) demonstrated decreased spontaneous ReHo values. In patients with XT, the correlation between the left BA47's mean ReHo value and duration of strabismus was positively significant.Conclusions: These findings indicate that patients with XT have severe neural dysfunction in the right V2 and left BA47, and pathological severity in the left BA47 is likely influenced by duration of ongoing strabismus. Therefore, these results may provide clinically important information toward understanding the underlying pathological mechanisms of XT and thus can be fundamental in future XT research.

Background As a polymicrobial disease, grape sour rot can lead to the decrease in the yield of grape berries and wine quality. The diversity of microbial communities in sour rot-infected grapes depends on the planting location of grapes and the identified methods. The east coast of China is one of the most important grape and wine regions in China and even in the world. Methods To identify the pathogenic microorganism s causing sour rot in table grapes of eastern coastal areas of China, the diversity and abundance of the bacteria and fungi were assessed based on two methods, including traditional culture-methods, and 16S rRNA and ITS gene high-throughput sequencing . Then the pathogenicity of cultivable microorganisms was determined in laboratory. Results Based on traditional culture-methods, we identified 15 cultivable bacterial species and 10 fungal species from sour rot-infected grapes. The p athogenicity assay confirmed five cultivated fungi species (three Aspergillus species, Alternaria tenuissima, and Fusarium proliferatum), and four bacteria species (two Cronobacter species, Serratia marcescens and Lysinibacillus fusiformis) as mainly pathogenic on grape. A. tenuissima, and F. proliferatum were the firstly discovered as pathogens on harvesting grape. Moreover, high-throughput sequencing revealed the OTUs numbers of bacteria and fungi were 1343.33 and 1038.67 respectively. Proteobacteria (72.15%) and Firmicutes (26.83%) were dominant phylums among the 19 bacterial phyla identified, while Ascomycota (93.86%) was the dominant fungal phylum. Then, bacteria such as Acetobacter sp., Gluconobacter sp., Bacillus sp., and Lactococcus sp. and fungi such as Incertae sedis sp., Issatchenkia terricola, Colletotrichum viniferum, Hanseniaspora vineae, Saprochaete gigas, and Candida diversa took the vast majority ofmicrobial species in sour rot-infected grapes. Therefore, more accurate and abundant microbial communities in sour rot-infected grapes could be identified using the traditional culture-methods and high-throughput sequencing.

A solid phase membrane adsorbent&mdash, a nylon 6 nanofibers membrane coated by polypyrrole (PPy-PA6-NFsM)&mdash, was firstly synthesized and used for extraction of two &beta, lactam antibiotics (oxacillin and cloxacillin) in urban river water. Then the analytes were detected by capillary electrophoresis with a diode array detector (CE-DAD). The synthesized nanofibers membrane was characterized by scanning electron microscopy and a Fourier transform infrared spectrometer. The experimental conditions were optimized, including the amount used of PPy-PA6-NFsM, pH of the sample solutions, adsorption volume, and desorption conditions. Under the optimal extraction and separation conditions, the detection limits were found to be 2.0 ng/mL for both oxacillin and cloxacillin. The proposed method was applied to the determination of the two &beta, lactams in water samples of an urban river. The recoveries of these two &beta, lactams were found to be in the range 84.2&ndash, 96.4%, demonstrating that PPy-PA6-NFsM has a high extraction capability for these two antibiotics. The relative standard deviations, ranging from 2.26% to 5.29% for intraday measurements and from 2.38% to 7.02% for inter-day determinations, were derived respectively.

This study investigated the activity of adenosine monophosphate-activated protein kinase (AMPK), glycolysis, and meat quality index in three altitude bovines during postmortem aging process. Local cattle (altitude:1,500 m), Gannan yak (3,000 m), and Yushu yak (4,500 m) postmortem Longissimus Dorsi (LD) muscle were used. Results indicated that CaCl2 significantly increased the AMPK activity by increasing the calcium-regulated protein kinase kinase (CaMKKβ) activity. Besides, AMPK activation enhanced the activity of lactate dehydrogenase (LDH) and Ca2+ -ATPase and accelerated the rate of muscle maturation during postmortem aging. Moreover, the expression of HIF-1, PRKAA2, and GLUT4 genes in high-altitude Yushu yak was higher than that of low-altitude bovines. CaCl2 activates AMPK by activating CaMKKβ cascade and accelerates postmortem glycolysis affecting the intramuscular environment, color, and muscle protein degradation to accelerate postmortem muscle maturation, suggesting that AMPK has essential effects on postmortem muscle glycolysis and quality, and can regulate muscle quality by regulating postmortem muscle AMPK activity. PRACTICAL APPLICATIONS: Insufficient postmortem glycolysis usually leads to DFD (dark, firm, and dry) meat. Beef have relatively high incidences of DFD meat, which has an unattractive dark color and causes significant loss to the meat industry. Therefore, AMPK, which can regulate postmortem glycolysis to affect meat quality, is a valid research target.

Background Chinese wild grapevine (Vitis amurensis) has remarkable cold stress tolerance, exceeding that of the common cultivated grapevine (Vitis vinifera L.). Result Here, we surveyed the expression dynamics of microRNAs (miRNAs) across Chinese wild grapevine (cv. Beibinghong) and cultivated grapevine (cv. Cabernet Sauvignon) under cold stress using high-throughput sequencing. We identified 186 known miRNAs in cultivated grape and 427 known miRNAs in Beibinghong. Of the identified miRNAs, 59 are conserved miRNAs orthologous in Cabernet Sauvignon and Beibinghong. In addition, 105 and 129 novel miRNAs were identified in Cabernet Sauvignon and Beibinghong, respectively. The expression of some miRNAs was related to cold stress both in Cabernet Sauvignon and Beibinghong. Many cold-related miRNAs in Cabernet Sauvignon and Beibinghong were predicted to target stress response-related genes such as MYB, WRKY, bHLH transcription factor genes, and heat shock protein genes. However, the expression tendency under cold treatment of many of these miRNAs was different between Cabernet Sauvignon and Beibinghong. Different modes of expression of cultivated and Chinese wild grape miRNAs were indicated in key pathways under cold stress by degradome, target prediction, GO, and KEGG analyses. Conclusion Our study indicated three likely reasons that led to the different cold stress tolerance levels of Cabernet Sauvignon and Beibinghong. Specifically, there may be (1) differential expression of orthologous miRNAs between cultivated grapevine and Chinese wild grape; (2) species-specific miRNAs or target genes; or (3) different regulatory models of miRNAs in cultivated and Chinese wild grape in some key pathways.

Enteroinvasive Escherichia coli (EIEC) are well-known food-borne pathogens that cause animal intestinal diseases. Lactobacillus is believed to inhibit intestinal pathogens and maintain a healthy gut microbiota. This study aimed to investigate the effects of pre-supplementation of Lactobacillus from yaks (4500m) to prevent the clinical symptoms and the improvement of the disordered flora caused by E. coli infection. Forty healthy mice were randomized to four study groups (n = 10); Leuconostoc pseudomesenteroides (LP1), Lactobacillus johnsonii (LJ1), blank control, and control groups. Mice in the LP1, LJ1, and control groups were intraperitoneally challenged with EIEC O124 (1 × 109 CFU) on day 23. After two days, the mice in control group were recorded for high mortality. The diarrhea in LP1 and LJ1 groups was much lower than that in the control group, and no death was recorded. In histopathology, pre-supplementation of LJ1 and LP1 relieved the damage to the liver, spleen and duodenum caused by E. coli. In addition, the normal intestinal microecology was also affected by infection of EIEC, including an increase in relative abundance of Proteobacteria. At the same time, the beneficial bacteria were increased and harmful bacteria were decreased in different intestinal segments of the LJ1 and LP1 groups compared to the control group. In conclusion, pre-supplementation of LP1 and LJ1 can mitigate EIEC-induced intestinal flora dysbiosis and can also reduce EIEC-associated diarrhea.

Rail corrugation often occurs on the high-speed railway, which will affect ride comfort and even the train operation safety in severe condition. Detection of rail corrugation wavelength and depth is absolutely essential for maintenance and safety. A novel method using wheel vibration acceleration is proposed in this paper, in which ensemble empirical mode decomposition (EEMD) is employed to estimate the wavelength, and bispectrum features are extracted to recognize the depth with support vector machine (SVM). Firstly, a vehicle-track coupling model considering the rail corrugation of high-speed railway is established to calculate the wheel vibration acceleration. Secondly, the estimation algorithm of wavelength is studied by analyzing the main frequency with EEMD. The optimal parameters of EEMD are selected according to the orthogonal coefficient of decomposition results and the distribution of the extreme points of signal. The depth detection is transformed to a classification problem with SVM. Bispectrum features, which are extracted from the reconstructed signal using the high-frequency components of wheel vibration acceleration, combining with train speed and corrugation wavelength are input into SVM to recognize the rail corrugation depth. Finally, numerical simulation is carried out to verify the accuracy of the proposed estimation method. The simulation results show that the proposed detection algorithm can accurately identify rail corrugation, the estimation error of rail corrugation wavelength is less than 0.25%, and the classification accuracy of rail corrugation depth is more than 99%.

Additional file 3: Table S3. Conseved miRNA orthologous between cultivated grape and Chinese wild grape.

Cement asphalt mortar (CA) disengagement of a ballastless track will induce changes of dynamic response of a passing vehicle, which can accordingly be used to estimate the disengagement degree. In this paper, a novel method called CA mortar disengagement degree estimation algorithm (CMDEA) is proposed through an analysis of wheel acceleration of a passing vehicle. The disengagement degree estimation is transformed into an optimization problem by regarding the CA mortar disengagement degree as a parameter of a vehicle-track coupling model. An improved genetic algorithm with a shifting window is employed for the parameter optimization, which is split into a number of phases and whose initial values are given in terms of a priori probabilities. The accuracy and robustness of the estimation are discussed, and the results are compared with regular genetic algorithm. The simulation results show that CMDEA can estimate CA mortar degrees with an acceptable accuracy. Meanwhile, the proposed algorithm has the advantages of a lower error value and much shorter computation time. Moreover, the robustness of the algorithm under different vehicle speeds, track irregularities, and signal noise levels is also verified.

Crack is a common tunnel disease, and the large crack directly affects the operation safety of the subway operations. Therefore, it is very important for tunnel safety to detect the tunnel surface crack accurately. The image processing technology based on machine vision has become the key method of automatic tunnel detection. In the field of image processing, it can be divided into two categories: traditional image processing algorithm and image processing algorithm based on deep learning. This paper uses a multi-stage cyclic filtering algorithm based on morphological processing and connected-domain filtering to extract the suspected tunnel crack region. Then the contaminated neural network is used to discriminate the suspected crack area. This paper uses the Open Source Computer Vision Library to write image processing algorithms in the Visual Studio environment. Construct a convolutional neural network using the deep learning framework Caffe. The experimental results show that the algorithm can realize the tunnel crack recognition under certain circumstances.

The detection of cracks which is one of the main diseases of the tunnel lining plays an important role in the tunnel safety. In order to improve the efficiency and accuracy of crack detection, this paper proposes an improved crack detection algorithm and an interface program for interaction. An image acquisition scheme based on a linear array camera system is proposed, and the system can be mounted on a track vehicle for image capturing. Experiments show that for the same image, the detection speed of improved algorithm is twenty times faster than the speed on MATLAB platform. In addition, this paper presents the design of three-dimensional display software for subway tunnel based on OpenGL, which is used to locate the position and predict the tendency of tunnel diseases.

A kinetic analysis of the oxidation of semicarbazide (SEM) by the single-electron oxidant [IrCl6]2− has been carried out by stopped-flow spectrometric techniques. The reaction proved to be first order each in [IrCl6 2−] and [SEM]tot, leading to overall second-order kinetics. The variation in the observed second-order rate constant k′ with pH was explored over the pH range of 0–7.11. Spectrophotometric titration revealed a stoichiometry of Δ[IrCl6 2−]/Δ[SEM]tot = 4:1 for the redox reaction. On the basis of the rate law, the redox stoichiometry, and the rapid scan spectra, a reaction mechanism is proposed which involves parallel attacks of [IrCl6]2− on both H2NCONHNH3 + and H2NCONHNH2 as rate-determining steps, followed by several rapid reactions. The rate expression, derived from the reaction mechanism, was utilized to simulate the k′–pH profile yielding a virtually perfect fit and indicating that the reaction path involving H2NCONHNH3 + does not make a significant contribution to the overall rate. The reaction between [IrCl6]2− and H2NCONHNH2 was further studied as a function of both temperature and ionic strength. From the temperature dependence, activation parameters were obtained as: ∆H 2 ‡ = 34.9 ± 1.5 kJ mol−1 and ∆S 2 ‡ = −78 ± 5 J K−1 mol−1. The observed ionic strength dependence suggests that the rate-determining step is between [IrCl6]2− and a neutral species of SEM. Hence, both the temperature and ionic strength dependency studies are in good agreement with the proposed reaction mechanism, in which the rate-determining step involves an outer sphere electron transfer.

A capillary electrophoresis method involving online indirect chemiluminescence (CL) detection was used to determine naphthol (NAP) isomers. The method was based on the quenching effect of 1- and 2-NAP on a new CL reaction of luminol with Ni(IV) complex in an alkaline medium. Separation was conducted with a 25.0 mM sodium borate buffer containing 0.8 mmol/L luminol. Under optimized conditions, 1- and 2-NAP were baseline separated and detected in less than 8 min. The limits of detection of 1- and 2-NAP were 3.1 and 2.7 μg/L, respectively (S/N = 3), with a linear range of 4.0-80.0 μg/L (r > 0.995). Analysis of real samples demonstrated that the spiked recoveries were in the range of 89.2-107.5% (n = 3). The proposed method was successfully used to determine 1- and 2-NAP contents in three environmental water samples and 14 human urine samples. No derivatization or tedious pretreatment was required in the analysis. The proposed method is a potential approach for routine tests of naphthol isomers in a facile CE-CL system.

A new, simple but efficient chemiluminescence system has been developed for determination of two β2-agonist drugs, ractopamine and fenoterol. The system is based on the chemiluminescence reaction of a Ni(IV) complex with luminol in alkaline media, while ractopamine or fenoterol can dramatically enhance chemiluminescence intensities. Under optimum conditions, chemiluminescence intensities are proportional to the concentrations of the drugs in the ranges of 1.0 × 10−8–1.0 × 10−6 mol dm−3 for ractopamine and of 1.0 × 10−9–1.0 × 10−7 mol dm−3 for fenoterol, respectively. The limits of detection (3σ) are 1.0 × 10−10 mol dm−3 for ractopamine and 1.0 × 10−11 mol dm−3 for fenoterol. Based on the kinetic characteristics of the chemiluminescence reaction, the chemiluminescence spectral change and free radical trapping experiment, a chemiluminescence reaction mechanism is proposed which involves free radicals in the Ni(IV)-luminol-ractopamine/fenoterol chemiluminescence systems. The mechanism of chemiluminescence enhancements by ractopamine/fenoterol to the Ni(IV)-luminol detection system is discussed.

In the present research, the application of a polypyrrole coating on Fe3O4 magnetic nanoparticles (PPy/Fe3O4 MNPs) as a sorbent was confirmed. The synthesized magnetic composites were characterized by TEM, FTIR spectroscopy, and XRD. Four β-lactams (oxacillin (OXA), cloxacillin (CLOX), dicloxacillin (DIC), and flucloxacillin (FLU)) were selected as analytes for the experiment. The extracted β-lactams were determined by micellar electrokinetic capillary chromatography-diode array detector (MEKC-DAD). The crucial parameters influencing the extraction efficiency and separation were studied and optimized. Under the optimal conditions, the limits of detection are 1.0 µg L−1 for OXA, CLOX, FLU, and 0.8 µg L−1 for DIC. The calibration curves are linear in the range of 2.5–200.0 µg L−1. The proposed method was applied for the determination of the β-lactams in water samples with satisfactory results. The intra-day relative standard deviations and the inter-day relative standard deviations range from 1.09% to 4.58% and from 2.95% to 7.80%, respectively. It can be concluded that this method is sensitive, convenient, and feasible for the determination of the β-lactams in water samples.

Veterinary drug residues, particularly traces of β2-agonists, can cause various kinds of harmful impact to the environment and public health. Here, a sensitive chemiluminescence (CL) method incorporated with a flow injection analysis is developed for the determination of two β2-agonists [i.e., salbutamol (SAL) and terbutaline (TEB)]. The system is based on the CL reaction of Ni(IV) complex with luminol in alkaline solutions, whereas SAL and TEB can significantly enhance CL intensities. Under optimum conditions, CL intensities are proportional to the SAL and TEB concentration in the range of 1.0 × 10−9 M to 5.0 × 10−7 M and 1.0 × 10−9 M to 1.0 × 10−7 M, respectively. The limits of detection (3σ) are 1.0 × 10−11 M for TEB, and 1.3 × 10−11 for SAL respectively. Relative standard deviations (n = 11) are less than 2% for 5.0 × 10−8 M SAL and TEB. Possible reaction mechanisms for the CL system are suggested based on the CL system spectra, Ni(IV) complex oxidation characteristics, and electron spin resonance (ESR) techniques. The proposed method has been applied to the analysis of urine and swine feed samples with satisfactory results.

The reaction mechanism of AgIII complex ([Ag(HIO6)2]5–) with ruthenium(II) bipyridine (Ru(bpy)32+) in acid medium was investigated. A novel flow injection chemiluminescence (CL) analysis method was developed for the detection of norfloxacin (NFLX) and ofloxacin (OFLX) in commercial drug, milk and human urine samples based on AgIII-ruthenium(II) bipyridine in acidic solution. Under optimal conditions, CL intensities were proportional to drug concentrations in the range of 1.6 × 10-9 to 8 × 10-6 g mL-1 for NFLX and 1.0 × 10-9 to 4 × 10-6 g mL-1 for OFLX. The detection limit was 1.0 × 10-9 g mL-1 for NFLX and 0.8 × 10-9 g mL-1 for OFLX. On the basis of the CL, UV and fluorescence spectra, possible reaction mechanisms were proposed.

Ormaplatin ([Pt(dach)Cl4]) is a prototypical of Pt(IV) anticancer prodrug; its reduction by 3,6-dioxa-1,8-octanedithiol (DODT, a model compound for the active site of thioredoxin), has been characterized at 25.0 °C and in a wide pH range by rapid scan spectral and kinetic analysis. The reduction follows overall second-order kinetics, being first-order each in [Pt(IV)] and in [DODT]; the observed second-order constant k′ versus pH profile has been established. A 1:1 reaction stoichiometry is obtained, indicating that DODT is oxidized to its intramolecular disulfide; these characteristics are consistent with the redox properties of thioredoxin. A reaction mechanism has been proposed which involves the three protolytic species of DODT attacking [Pt(dach)Cl4] in parallel as rate-determining steps. The rate equation is derived from the reaction mechanism and rate constants of the rate-determining steps have been evaluated. The thiol–thiolate and dithiolate forms of DODT are 105–106 times more reactive than the dithiol form. Comparisons of the rate constants highlight that the electron density of the sulfur atom plays a key role in determining the reactivity of DODT toward ormaplatin and similar Pt(IV) compounds. It is concluded that the reduced thioredoxin is a strong competitor to other thiol-containing compounds in the reduction processes of Pt(IV) anticancer prodrugs.