Effects of PEF on Cell and Transcriptomic of Escherichia coli.

Pulsed electric field (PEF) is an up-to-date non-thermal processing technology with a wide range of applications in the food industry. The inactivation effect of PEF on Escherichia coli was different under different conditions. The E. coli inactivated number was 1.13 ± 0.01 lg CFU/mL when PEF was treated for 60 min and treated with 0.24 kV/cm. The treatment times were found to be positively correlated with the inactivation effect of PEF, and the number of E. coli was reduced by 3.09 ± 0.01 lg CFU/mL after 100 min of treatment. The inactivation assays showed that E. coli was inactivated at electrical intensity (0.24 kV/cm) within 100 min, providing an effective inactivating outcome for Gram-negative bacteria. The purpose of this work was to investigate the cellular level (morphological destruction, intracellular macromolecule damage, intracellular enzyme inactivation) as well as the molecular level via transcriptome analysis. Field Emission Scanning Electron Microscopy (TFESEM) and Transmission Electron Microscope (TEM) results demonstrated that cell permeability was disrupted after PEF treatment. Entocytes, including proteins and DNA, were markedly reduced after PEF treatment. In addition, the activities of Pyruvate Kinase (PK), Succinate Dehydrogenase (SDH), and Adenosine Triphosphatase (ATPase) were inhibited remarkably for PEF-treated samples. Transcriptome sequencing results showed that differentially expressed genes (DEGs) related to the biosynthesis of the cell membrane, DNA replication and repair, energy metabolism, and mobility were significantly affected. In conclusion, membrane damage, energy metabolism disruption, and other pathways are important mechanisms of PEF's inhibitory effect on E. coli.

miR-34c-5p inhibited fibroblast proliferation, differentiation and epithelial-mesenchymal transition in benign airway stenosis via MDMX/p53 pathway.

Benign airway stenosis (BAS) means airway stenosis or obstruction that results from a variety of non-malignant factors, including tuberculosis, trauma, benign tumors, etc. In consideration of the currently limited research on microRNAs in BAS, this study aimed to explore the role and mechanism of miR-34c-5p in BAS. The expression of miR-34c-5p in BAS granulation tissues showed a significant down-regulation compared with the normal control group. Moreover, miR-34c-5p mimics suppressed the proliferation and differentiation of human bronchial fibroblasts (HBFs) and the epithelial-mesenchymal transition (EMT) of human bronchial epithelial cells (HBE). Conversely, miR-34c-5p inhibitors aggravated those effects. A dual-luciferase reporter assay confirmed that miR-34c-5p can target MDMX rather than Notch1. The over-expression of MDMX can reverse the inhibiting effect of miR-34c-5p on HBFs proliferation, differentiation and EMT. Furthermore, the expressions of tumor protein (p53) and PTEN were down-regulated following the over-expression of MDMX. In addition, the expressions of PI3K and AKT showed an up-regulation. In conclusion, miR-34c-5p was down-regulated in BAS and may inhibit fibroblast proliferation differentiation and EMT in BAS via the MDMX/p53 signaling axis. These findings expand the understanding of the role of miR-34c-5p and will help develop new treatment strategies for BAS.

Down-regulation of miR-21-5p by pirfenidone to inhibit fibroblast proliferation in the treatment of acquired tracheal stenosis.

OBJECTIVE: Treatment options for acquired tracheal stenosis (ATS) are limited due to a series of pathophysiological changes including inflammation and cell proliferation. Micro ribonucleic acid-21-5p (miR-21-5p) may promote the excessive proliferation of fibroblasts. However, various types of fibrosis can be prevented with pirfenidone (PFD). Currently, the effect of PFD on miR-21-5p and its biological function has not been clarified. In this study, PFD was evaluated as a potential treatment for ATS by inducing fibroblast proliferation in lipopolysaccharide (LPS)-induced fibroblasts by targeting miR-21-5p. METHODS: For 48 h, 1 g/ml LPS was used to generate fibroblasts in vitro, followed by the separation of cells into four groups: control, PFD, mimic, and mimic + PFD. The Cell Counting Kit-8 (CCK-8) technique was adopted to measure the proliferation of fibroblasts. Real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot (WB) were used to measure the relative expressions of tumor necrosis factor-α (TNF-α), transforming growth factor-ß1 (TGF-ß1), drosophila mothers against decapentaplegic 7 (Smad7) and collagen type I alpha 1(COL1A1) messenger RNA (mRNA) and proteins, respectively. RESULTS: (1) At 0, 24, 48, and 72 h, fibroblast growth was assessed using the CCK-8 method. Compared with the control group, the mimic group showed the highest fibroblast viability, and the PFD group showed the lowest fibroblast viability. However, fibroblast viability increased in the mimic + PFD group but decreased in the mimic one. (2) RT-qPCR and WB showed that the mimic group exhibited a significant up-regulation in the relative expressions of TNF-α, TGF-ß1, and COL1A1 mRNA and proteins but a down-regulation in the relative expression of Smad7 mRNA and protein compared with the control one. In the PFD group, the results were the opposite. Nevertheless, the relative expressions of TNF-α, TGF-ß1, and COL1A1 mRNA and proteins were increased, whereas that of Smad7 mRNA was decreased in the mimic + PFD group. The change was less in the mimic group. CONCLUSION: PFD may have a preventive and curative effect on ATS by inhibiting fibroblast proliferation and the fibrotic process and possibly through down-regulating miR-21-5p and up-regulating Smad7 and its mediated fibrotic and inflammatory responses.

Identification and verification of microtubule associated genes in lung adenocarcinoma.

Associated with high morbidity and mortality, lung adenocarcinoma (LUAD) is lacking in effective prognostic prediction and treatment. As chemotherapy drugs commonly used in clinics, microtubule-targeting agents (MTAs) are limited by high toxicity and drug resistance. This research aimed to analyze the expression profile of microtubule-associated genes (MAGs) in LUAD and explore their therapy efficiency and impact on prognosis. Key MAGs were identified as novel molecular targets for targeting microtubules. The LUAD project in The Cancer Genome Atlas (TCGA) database was used to identify differently expressed MAGs. On the one hand, a microtubule-related prognostic signature was constructed and validated, and its links with clinical characteristics and the immune microenvironment were analyzed. On the other hand, hub MAGs were obtained by a protein-protein interaction (PPI) network. Following the expression of hub MAGs, patients with LUAD were classified into two molecular subtypes. A comparison was made of the differences in half-maximal drug inhibitory concentration (IC50) and tumor mutational burden (TMB) between groups. In addition, the influence of MAGs on the anticancer efficacy of different therapies was explored. MAGs, which were included in both the prognosis signature and hub genes, were considered to have great value in prognosis and targeted therapy. They were identified by quantitative real-time polymerase chain reaction (qRT-PCR). A total of 154 differently expressed MAGs were discovered. For one thing, a microtubule-related prognostic signature based on 14 MAGs was created and identified in an external validation cohort. The prognostic signature was used as an independent prognostic factor. For another, 45 hub MAGs were obtained. In accordance with the expression profile of 45 MAGs, patients with LUAD were divided into two subtypes. Distinct differences were observed in TMB and IC50 values of popular chemotherapy and targeted drugs between subtypes. Finally, five genes were included in both the prognosis signature and hub genes, and identified by qRT-PCR. A microtubule-related prognosis signature that can serve as an independent prognostic factor was constructed. Microtubule subtype influenced the efficacy of different treatments and could be used to guide therapy selection. In this research, five key MAGs, including MYB proto-oncogene like 2 (MYBL2), nucleolar and spindle-associated protein 1 (NUSAP1), kinesin family member 4A (KIF4A), KIF15 and KIF20A, were verified and identified. They are promising biomarkers and therapeutic targets in LUAD.

Analysis of clinical characteristics of 617 patients with benign airway stenosis.

Introduction: Benign airway stenosis (BAS), namely airway narrowing caused by a variety of benign lesions, can lead to varying degrees of breathing difficulties and even death due to asphyxia. This study aimed to elucidate the clinical characteristics of BAS, including etiology, treatment and pathology, by analyzing the clinical data of BAS patients. Methods: A retrospective analysis was conducted using the clinical data of 617 BAS cases from January 2017 to December 2022. The pathological characteristics of the tissues were assessed by hematoxylin-eosin (H&E) and Masson's staining. Besides, protein expression levels were determined by immunohistochemistry (IHC). Results: A total of 617 patients were included (333 females [53.97%] and 284 males [46.03%]), with an average age of 48.93 ± 18.30 (range 14-87). Tuberculosis (n = 306, 49.59%) and trauma (n = 179, 29.02%) were the two leading etiologies of BAS, followed by airway foreign bodies (FB, n = 74, 11.99%), external compression (n = 25, 4.05%) and other etiologies (n = 33, 5.35%). Among 306 tuberculous tracheobronchial stenosis (TBTS) cases, most were females (n = 215, 70.26%), and TBTS mainly occurred in the left main bronchus (n = 97, 31.70%), followed by the right middle bronchus (n = 70 cases, 22.88%). The majority of TBTS patients (n = 259, 84.64%) were treated by interventional therapy. The condition of 179 BAS patients was ascribed to trauma, such as tracheal intubation (n = 92, 51.40%), tracheotomy (n = 69, 38.56%), injury (n = 15, 8.38%) and surgery (n = 3, 1.68%), which mostly took place in the trachea (n = 173, 96.65%). TAS patients mainly received interventional therapy (n = 168, 93.85%) and stent implantation (n = 47, 26.26%). The granulation tissues of BAS primarily featured inflammation, proliferation and fibrosis. IHC indicated the up-regulated expressions of transforming growth factor-ß1 (TGF-ß1), α-smooth muscle actin (α-SMA), collagen type I protein (COL-I) and vimentin, and the down-regulated expression of E-cadherin, which indicated fibrosis and epithelial-mesenchymal transition (EMT). Conclusion: Tuberculosis was the main etiology, and trauma was the secondary etiology. The granulation tissues of BAS were characterized by inflammation, fibrosis and probably EMT. Comprehensive interventional therapy is an effective method of treating BAS.

Distribution and chemotactic mechanism of CD4+ T cells in traumatic tracheal stenosis.

A systemic and local inflammatory immune imbalance is thought to be the cause of traumatic tracheal stenosis (TS). However, with CD4+ T lymphocytes being the predominant immune cells in TS, the mechanism of action and recruitment has not been described. In our research, using flow cytometry, ELISA, immunofluorescence, and Transwell chamber assays, the expression, distribution, and potential chemotactic function of CD4+ T cells in TS patients were examined before and after treatment. The results showed that the untreated group had significantly more CD4+ T cells and their secreted TGF-ß1 than the treated group. Additionally, the untreated group's CD4+ T cells showed a significant rise in CCL22 and CCL1, as well as a larger proportion of CCR4 and CCR8. CD4+ T cells and CD68+ macrophages located in TS also expressed CCL1 and CCL22. In vitro, anti-CCL1 and anti-CCL22 can partially block the chemoattractant effect of TS bronchoalveolar lavage (BAL) on purified CD4+ T cells. The findings of this study indicated that TS contained unbalanced CD4 immune cells that were actively recruited locally by CCR4/CCL22 and CCR8/CCL1. As a result, it is anticipated that CD4 immune rebalancing can serve as a novel treatment for TS.

Identification of potential prognostic markers for lung adenocarcinoma using comprehensive analysis.

Lung adenocarcinoma (LUAD) is a common malignancy throughout the world with high levels of mortality and morbidity. In the present study, potential biomarkers and treatment targets for LUAD were investigated using data from The Cancer Genome Atlas. Overall, 4,485 differentially expressed genes (DEGs) were identified (1,857 upregulated and 2,628 downregulated) between tumor and adjacent control tissues. Functional analysis with Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, Gene Set Variation Analysis and Gene Set Enrichment Analysis revealed significant enrichment of the DEGs in pathways related to system development, cell cycle and cell adhesion. Weighted gene co­expression network analysis distinguished ten co­expression modules on inclusion of the clinical profiles of patients with LUAD. Of these, the blue/turquoise modules showed peak association with tumor onset. Analysis of hub modules identified five hub genes, namely ANGPTL7, SLC6A4, PTPRQ, KCNA4 and TEDC2 (also known as C16orf59). Survival analysis revealed associations between hub­gene expression profiles and patient prognosis. Downregulation of SLC6A4 in LUAD tumor tissues was confirmed using immunohistochemistry. Additional assays (Cell Counting Kit­8, colony formation, scratch assay, cell cycle, Transwell invasion assay and cell adhesion assay) revealed that SLC6A4 overexpression inhibited A549 cell growth, invasion and migration. The findings demonstrated that the hub genes could act as treatment targets or new biomarkers for LUAD.

Targeted therapy for multiple gene mutations in multiple metastases of advanced gastric cancer: a case report.

In China, gastric cancer is the second most common cause of cancer-related death, after lung cancer. At present, the morbidity and mortality rates of gastric cancer are increasing, and targeted therapy for gastric cancer has become a research hotspot. Herein, we report a patient with multiple metastases from advanced gastric cancer. After identifying MET gene amplification, initial treatment induced regression of the tumor. However, in later stages, due to the overexpression or mutation of HER-2, KRAS, TP53, and other genes, the targeted drug therapy became ineffective, and the disease progressed rapidly, leading to the death of the patient.

Differential expression of miRNAs revealed by small RNA sequencing in traumatic tracheal stenosis.

Introduction: Traumatic tracheal stenosis (TTS) is a major cause of complex difficult airways, without clinically definitive efficacious drugs available. The aim of this study was to provide a general view of interactions between micro and messenger ribonucleic acids (miRNAs and mRNAs) and many potential mechanisms in TTS via small RNA sequencing. Methods: In this study, the identification of miRNAs was completed using small RNA sequencing and samples from four TTS patients and four normal control cases. By using bioinformatics tools, such as miRanda and RNAhybrid, for identifying the candidate target genes of miRNAs with differential expression in each sample, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes were employed for enriching the predicted target genes of miRNAs with differential expression based on the correspondence between miRNAs and their target genes. We detected the expression of the candidate miRNAs using quantitative real-time polymerase chain reaction (qRT-PCR). Results: Twenty-four miRNAs with significant differential expression were identified, including 13 upregulated and 11 downregulated ones. Bioinformation technology was adopted to predict 2,496 target genes. These miRNA-target genes were shown to be primarily enriched in cells and organelles with catalytic activity and binding function, such as binding proteins, small molecules, and nucleotides. Finally, they were observed to process into TTS through the intercellular and signal regulation of related inflammatory signaling and fibrosis signaling pathways. QRT-PCR confirmed the upregulation of miR21-5p and miR214-3p and the downregulation of miR141-3p and miR29b-3p, which was expected to become a high-specific miRNA for TTS. Conclusion: Among all the miRNAs detected, 24 miRNAs demonstrated differential expression between the TTS and normal control groups. A total of 2,496 target genes were predicted by bioinformation technology and enriched in inflammatory and fibrotic signaling pathways. These results provide new ideas for further studies and the selection of targets for TTS in the future.

Clinical course and management of insidious adrenal crisis manifested initially as hyperpyrexia secondary to pembrolizumab: Case reports and literature review.

Immune checkpoint inhibitors (ICIs) are novel drugs with a dramatic survival benefit in patients with advanced malignancies. With the widespread use, several immune-related adverse events (irAEs) have emerged, which may be life-threatening. Herein we report two patients with adrenal crisis who received anti-programmed cell death protein 1 (PD-1) (pembrolizumab) therapy. Several reports of secondary adrenal insufficiency caused by pembrolizumab exist, including during treatment or late onset. Severe adrenal insufficiency according to the Common Terminology Criteria for Adverse Events (CTCAE) has rarely been described in the literature, since it initially manifests as high-grade fever. The two male patients developed adrenal crisis that was first characterized by hyperpyrexia accompanied by abdominal symptoms. These initial manifestations confused the clinicians who misdiagnosed them as infection. Timely identification, hydrocortisone pulse therapy, and fluid resuscitation improved the patients' condition. Compliance with the standardized treatment approach and course can prevent or relieve the crisis as soon as possible. Assessment of relevant laboratory test results and patient education, including when to use stress-dose hydrocortisone and guidance on route of administration, can reduce the incidence of adrenal crisis. We report these two cases and have evaluated the literature on previously reported cases to improve our understanding of this condition and offer a more scientific approach to diagnosis and treatment options.

Prognostic Risk Signature and Comprehensive Analyses of Endoplasmic Reticulum Stress-Related Genes in Lung Adenocarcinoma.

Lung adenocarcinoma (LUAD) is the main pathological subtype of non-small-cell lung cancer. Endoplasmic reticulum stress (ERS) has been found to be involved in multiple tumor-related biological processes. At present, a comprehensive analysis of ERS-related genes in LUAD is still lacking. A total of 1034 samples from TCGA and GEO were used to screen differentially expressed genes. Further, Random Forest algorithm was utilized to screen characteristic genes related to prognosis. Then, LASSO Cox regression was used to construct a prognostic signature. Taking the median of signature score as the threshold, patients were separated into high-risk (HR) group and low-risk (LR) group. Tumor mutation burden (TMB), immune cell infiltration, cancer stem cell infiltration, expression of HLA, and immune checkpoints of the two risk groups were analyzed. TIDE score was used to evaluate the response of the two risk groups to immunotherapy. Finally, the gene expression was verified in clinical tissues with RT-qPCR. An eight-gene signature (ADRB2, AGER, CDKN3, GJB2, SFTPC, SLC2A1, SLC6A4, and SSR4) was constructed. TMB and cancer stem cell infiltration were higher in the HR group than the LR group. TIDE score and expression level of HLA were higher in the LR group than the HR group. Expression level of immune checkpoints, including CD28, CD27, IDO2, and others, were higher in the LR group. Multiple drugs approved by FAD, targeting ERS-related genes, were available for the treatment of LUAD. In summary, we established a stable prognostic model based on ERS-related genes to help the classification of LUAD patients and looked for new treatment strategies from aspects of immunity, tumor mutation, and tumor stem cell infiltration.

Optimization of Headspace Solid-Phase Micro-Extraction Conditions (HS-SPME) and Identification of Major Volatile Aroma-Active Compounds in Chinese Chive (Allium tuberosum Rottler).

In order to rapidly and precisely identify the volatile compounds in Chinese chive (Allium tuberosum Rottler), seven key parameters of headspace solid-phase micro-extraction conditions (HS-SPME) from Chinese chive were optimized. A total of 59 volatile compounds were identified by using the optimized method, including 28 ethers, 15 aldehydes, 6 alcohols, 5 ketones, 2 hydrocarbons, 1 ester, and 2 phenols. Ethers are the most abundant, especially dimethyl trisulfide (10,623.30 µg/kg). By calculating the odor activity values (OAVs), 11 volatile compounds were identified as the major aroma-active compounds of Chinese chive. From the analysis of the composition of Chinese chive aroma, the "garlic and onion" odor (OAV = 2361.09) showed an absolute predominance over the other 5 categories of aroma. The results of this study elucidated the main sources of Chinese chive aroma from a chemical point of view and provided the theoretical basis for improving the flavor quality of Chinese chive.

Effects of iron-catalyzed and metmyoglobin oxidizing systems on biochemical properties of yak muscle myofibrillar protein.

The objective of this study was to compare the effects of two oxidation systems on the biochemical properties of yak myofibrillar protein (MP). Oxidation was induced by incubating MP with either an iron-catalyzed oxidizing system (IOS) or a metmyoglobin-oxidizing system (MOS). The following indicators of protein oxidation and protein degradation were analyzed. The carbonyl, disulfide bonds, dityrosine, and ß-sheet content increased markedly with oxidant concentration in both systems(P < .05), whereas the total sulfhydryl, surface hydrophobicity and α-helix content decreased significantly(P < .05). Furthermore, the MOS carbonyl formation rate was significantly faster than the IOS rate, and the MOS significantly affected the formation of disulfide bonds and inhibited the exposure of hydrophobic amino acids. Both oxidative systems promoted cross-linking of myosin heavy chains (MHCs) and action, but the degree of cross-linking in IOS was greater than that in MOS. MOS also promoted cross-linking of myosin light chains (MLCs). IOS and MOS produced mainly 20-25-kDa and 20-17-kDa MLC degradation products, respectively. In conclusion, oxidation caused cross-linking in MHCs or MLCs through disulfide bonds, but the extent of such cross-linking was oxidant dose-dependent and specific to each oxidizing system.

Cytoplasmic hnRNPK interacts with GSK3ß and is essential for the osteoclast differentiation.

Osteoclast differentiation is a complex and finely regulated physiological process that involves a variety of signaling pathways and factors. Recent studies suggested that the Ser9 phosphorylation of Glycogen synthase kinase-3ß (GSK3ß) is required for the osteoclast differentiation. However, the precise underlying mechanism remains unclear. We have previously identified the heterogeneous nuclear ribonucleoprotein K (hnRNPK) as a putative GSK3ß interactor. In the present study, we demonstrate that, during the RANKL-induced osteoclast differentiation, the PI3K/Akt-mediated Ser9 phosphorylation of GSK3ß provokes the nuclear-cytoplasmic translocation of hnRNPK in an ERK-dependent manner, enhancing the cytoplasmic co-localization and interaction of GSK3ß and hnRNPK. We show that hnRNPK is essential for the osteoclast differentiation, and is involved in several reported functions of GSK3ß, including the activation of NF-κB, the expression of NFATc1, and the acetylation of tubulin, all known to be critical for osteoclast differentiation and functions. We find that hnRNPK is localized in the actin belt, and is important for the mature osteoclast formation. Taken together, we demonstrate here the critical role of hnRNPK in osteoclast differentiation, and depict a model in which the cytoplasmic hnRNPK interacts with GSK3ß and regulates its function.

A homogeneous time-resolved fluorescence-based high-throughput screening for discovery of inhibitors of Nef-sdAb19 interaction.

The human immunodeficiency virus (HIV) protein negative factor (Nef) is important for AIDS pathogenesis. An anti-Nef single-domain antibody (sdAb19) derived from camelids has been previously generated and shown to effectively block the physiological functions of Nef in vitro and in vivo in nef-transgenic mice. However, sdAb19 must be ectopically expressed within the target cell to be able to exert its neutralizing effect on Nef, while the extra-cellular administration method turned out to be ineffective. This might suggest a default of the stability or/and deliverability of sdAb19. The identification of small molecule compounds capable of inhibiting the Nef-sdAb19 interaction and mimicking the neutralizing activity of sdAb19 in vivo would therefore be the means of circumventing the problem encountered with sdAb19. Here we describe the development of a high-throughput screening method combining the homogeneous time-resolved fluorescence (HTRF) and the microscale thermophoresis (MST) techniques for the identification of small-molecule compounds inhibiting the Nef-sdAb19 interaction by binding to Nef protein. Eight small-molecule compounds have been selected for their ability to significantly inhibit the Nef-sdAb19 interaction and to bind to Nef. These molecules could be further assessed for their potential of being the Nef-neutralizing agents in the future.

Unexpectedly strong magnetic anisotropy in a mononuclear eight-coordinate cobalt(II) complex: a theoretical exploration.

Ab initio methods have been used to explore the unexpectedly strong magnetic anisotropy and the magnetostructural correlations in mononuclear eight-coordinate complex [Co(II)(12-crown-4)2](2+). Our calculations showed that both decreasing α and increasing φ may enhance its magnetic anisotropy, which was rationalized by the qualitative theory proposed by Long and co-workers. Moreover, we deduced that the |D| value of [Co(II)(12-crown-4)2](2+) with α = 52° and φ = 43° is the largest one.

[Interaction of Flightless I with Nup88 and Importin ß].

High expression of Fightless I (FLII) is associated to multiple tumors. Based on our previous study that FLII might be involved in the nuclear export, we assessed the possible interaction of FLII with the nuclear envelop associating proteins Importin ß and Nup88. We first constructed GST-FLII, GST-LRR recombinant plasmids and transformed them into the Rosetta strain to produce GST-FLII, GST-LRR fusion protein. After purification of these proteins, GST-pull down, as well as co-immunoprecipitation, were used to test the interaction of FLII with Importin ß and Nup88. FLII interacted with Importin ß and Nup88, and FLII LRR domain is responsible for these interactions. Thus, FLII may play a role in nuclear export through interaction with Importin ß and Nup88.

Determination of 15 sedative residues in mutton by rapid resolution liquid chromatography-tandem mass spectrometry.

BACKGROUND: The use of xenobiotic compounds in animal husbandry has given rise to consumer anxieties regarding residual risk and food safety. Thus, animal tissues have become main samples for residue analysis and food safety for sedatives. In this study, a rapid resolution liquid chromatography-tandem mass spectrometry (RRLC-MS/MS) method was established for the determination of 15 sedatives residues in mutton. RESULTS: After enzymolysis, sedatives residues in mutton were extracted by ammonium hydroxide-acetonitrile (10:90, v/v) and determined by RRLC-MS/MS with quantification by standard curve method. The calibration curves showed good linearity within the concentrations of 0.5-50 µg kg(-1) with the correlation coefficients (r(2)) ranged from 0.9639 to 0.9984. The limits of detection (LODs) and quantification (LOQs) were 0.25-2.5 and 0.5-5 µg kg(-1), respectively. The average recoveries of spikes samples were in the ranges of 74.1-116.8% with relative standard deviations of intra- and inter-day ranged from 2.6% to 11.2% and from 2.1% to 11.4%, respectively. CONCLUSION: This method is simple, sensitive and accurate in the determination of sedative residues.

Slow magnetic relaxation in a mononuclear eight-coordinate cobalt(II) complex.

The quest for the single-molecular magnets (SMMs) based on mononuclear transition-metal complexes is focused on the low-coordinate species. No transition-metal complex with a coordination number of eight has been shown to exhibit SMM properties. Here the magnetic studies have been carried out for a mononuclear, eight-coordinate cobalt(II)-12-crown-4 (12C4) complex [Co(II)(12C4)2](I3)2(12C4) (1) with a large axial zero-field splitting. Magnetic measurements show field-induced, slow magnetic relaxation under an applied field of 500 Oe at low temperature. The magnetic relaxation time τ was fitted by the Arrhenius model to afford an energy barrier of Ueff = 17.0 cm(-1) and a preexponential factor of τ0 = 1.5 × 10(-6) s. The work here presents the first example of the eight-coordinate, mononuclear, 3d metal complex exhibiting the slow magnetic relaxation.

The Global Volatile Signature of Veal via Solid-phase Microextraction and Gas Chromatography-mass Spectrometry.

The volatile composition of veal has yet to be reported and is one of the important factors determining meat character and quality. To identify the most important aroma compounds in veal from Holstein bull calves fed one of three diets, samples were subjected to solid-phase microextraction (SPME) combined with gas chromatography-quadrupole mass spectrometry (GC-MS). Most of the important odorants were aldehydes and alcohols. For group A (veal calves fed entirely on milk for 90 d before slaughter), the most abundant compound class was the aldehydes (52.231%), while that was alcohols (26.260%) in group C (veal calves fed starter diet for at least 60 d before slaughter). In both classes the absolute percentages of the volatile compounds in veal were different indicating that the veal diet significantly (p<0.05) affected headspace volatile composition in veal as determined by principal component analysis (PCA). Twenty three volatile compounds showed significance by using a partial least-squared discriminate analysis (PLS-DA) (VIP>1). The establishment of the global volatile signature of veal may be a useful tool to define the beef diet that improves the organoleptic characteristics of the meat and consequently impacts both its taste and economic value.