Lactobacillus Firm-5-derived succinate prevents honeybees from having diabetes-like symptoms.

The gut microbiome plays an important role in honeybee hormonal regulation and growth, but the underlying mechanisms are poorly understood. Here, we showed that the depletion of gut bacteria resulted in reduced expression of insulin-like peptide gene (ilp) in the head, accompanied by metabolic syndromes resembling those of Type 1 diabetes in humans: hyperglycemia, impaired lipid storage, and decreased metabolism. These symptoms were alleviated by gut bacterial inoculation. Gut metabolite profiling revealed that succinate, produced by Lactobacillus Firm-5, played deterministic roles in activating ilp gene expression and in regulating metabolism in honeybees. Notably, we demonstrated that succinate modulates host ilp gene expression through stimulating gut gluconeogenesis, a mechanism resembling that of humans. This study presents evidence for the role of gut metabolite in modulating host metabolism and contributes to the understanding of the interactions between gut microbiome and bee hosts.

Sesamin inhibits RANKL-induced osteoclastogenesis and attenuates LPS-induced osteolysis via suppression of ERK and NF-κB signalling pathways.

Infection by bacterial products in the implant and endotoxin introduced by wear particles activate immune cells, enhance pro-inflammatory cytokines production, and ultimately promote osteoclast recruitment and activity. These factors are known to play an important role in osteolysis as well as potential targets for the treatment of osteolysis. Sesamin has been shown to have a variety of biological functions, such as inhibiting inflammation, anti-tumour and involvement in the regulation of fatty acid and cholesterol metabolism. However, the therapeutic effect of sesamin on osteolysis and its mechanism remain unclear. Present studies shown that in the condition of in vitro, sesamin could inhibit osteoclastogenesis and bone resorption, as well as suppressing the expression of osteoclast-specific genes. Further studies on the mechanism suggest that the effect of sesamin on human osteoclasts was mediated by blocking the ERK and NF-κB signalling pathways. Besides, sesamin was found to be effective in treating LPS-induced osteolysis by decreasing the production of pro-inflammatory cytokines and inhibiting osteoclastogenesis in vivo. Sesamin was non-toxic to heart, liver, kidney, lung and spleen. Therefore, sesamin is a promising phytochemical agent for the therapy of osteolysis-related diseases caused by inflammation and excessive osteoclast activation.

A Multifunctional Liposome for Synergistic Chemotherapy with Ferroptosis Activation of Triple-Negative Breast Cancer.

There is an urgent need to develop efficient treatments for highly invasive triple-negative breast cancer (TNBC) with a high rate of postoperative. Baicalin (BA) has shown inhibitory effects on several tumor cells and could activate ferroptosis in some tumor cells by producing reactive oxygen species (ROS). For overcoming the shortcomings of BA in clinical applications and enhancing the effect of ferroptosis in TNBC, herein, a multifunctional liposome (BA-Fe(III) coordination-polymer-loaded liposome, BA-Fe(III) Lipo) was developed for synergistic chemotherapy of TNBC with ferroptosis activation. Fe(III) released from BA-Fe(III) Lipo could be efficiently reduced to Fe(II) in the presence of high glutathione in tumor microenvironment, which in turn catalyzed the oxidation of unsaturated fats through lipid peroxidation for more ROS production. In addition, BA-Fe(III) Lipo activated tumor cell ferroptosis by down-regulating the enzymatic activity of ferritin heavy chain 1 protein and glutathione peroxidase. This study provided a novel therapeutic strategy for the treatment of TNBC by ingeniously combining chemotherapy with the activation of ferroptosis, which presented potential clinical applications.

Assessing the effects of NapA gene overexpression on denitrification and denitrogenation in magnetospirillum gryphiswaldense MSR-1.

Previous research on Magnetospirillum gryphiswaldense MSR-1 found that MSR-1 has a good denitrification nitrogen removal ability and specific application prospects in the sewage biological nitrogen removal field. Therefore, this study selected the essential denitrification gene NapA in MSR-1-wt for overexpression, and the overexpressed MSR-1-NapA was successfully constructed. Q-PCR amplification experiment and AGAR gel electrophoresis experiment proved that the relative transcription level of the NapA gene was increased by more than four times, and the denitrification ability of MSR-1-wt and MSR-1-NapA was further determined by enzyme activity experiment, denitrification experiment, and flow cytometry. The results showed that overexpression of the NapA gene increased nitrate reductase activity in MSR-1-NapA by more than four times. In the solution with a nitrate concentration of 118.33 ± 3.23 mgN/L, the denitrification efficiency of MSR-1-NapA was superior to that of MSR-1-wt, significantly enhancing both the denitrification and nitrogen removal capacities of MSR-1. This indicates its greater potential for biological nitrogen removal in wastewater treatment.

Intramolecular Hosomi-Sakurai Reaction for the Synthesis of Benzoxasiloles.

A Lewis acid-catalyzed intramolecular Hosomi-Sakurai reaction of o-(allylsilyl)benzaldehyde/ketone has been developed. The reaction proceeds through simultaneous C-Si bond cleavage and C-C bond reconstruction. This protocol provides a rapid approach for the synthesis of allyl-substituted benzoxasiloles under mild conditions.

Recycling of Polydicyclopentadiene Enabled with N-Coordinated Boronic Ester Bonds.

In this contribution, the transformation of polydicyclopentadiene (PDCPD) from thermoset into vitrimer is introduced. First, two N-coordinated diboronic diols are successfully synthesized via the reaction of N,N,N-tri(2-hydroxyethyl)amine and/or N,N,N",N"-tetrakis(2-hydroxyethyl)ethylene diamine with 4-(hydroxymethyl) phenylboronic acid and then they are transformed into two N-coordinated cyclic boronic diacrylates. The latter two dienes carrying electron-withdrawing substituents are used for the ring opening insertion metathesis copolymerization (ROIMP) of dicyclopentadiene to afford the crosslinked PDCPD. In the crosslinked PDCPD networks, N-coordinated cyclic boronic ester bonds are integrated. It is found that the as-obtained PDCPD networks displayed the excellent reprocessing properties. In the meantime, the fracture toughness is significantly improved. Owing to the inclusion of N-coordinated cyclic boronic ester bonds, the modified PDCPDs have the thermal stability much superior to plain PDCPD. The results reported in this work demonstrate that PDCPD can successfully be transformed into the vitrimers via the introduction of N-coordinated cyclic boronic ester bonds.

[Determination of twelve halobenzoquinones in drinking water by solid phase extraction-ultra-performance liquid chromatography-tandem mass spectrometry].

OBJECTIVE: To establish a method for twelve halobenzoquinones(HBQs) in drinking water by solid phase extraction-ultra-performance liquid chromatography coupled with electrospray-tandem mass spectrometry(SPE-UPLC-MS/MS). METHODS: The drinking water was acidified with formic acid and concentrated by Bond Elut Plexa solid phase extraction column. The sample solution was separated using Waters ACQUITY HSS T3 column(100 mm×2.1 mm, 1.8 µm) with gradient elution using methanol-water containing 0.1% formic acid as mobile phase. The target compouds were detected in negtive electrospray ionization(ESI~-) and multiple reaction monitoring. RESULTS: The concentration of twelve HBQs showed good linearity in the range 5.0-150.0 ng/mL, respectively, with the correlation coefficients greater than 0.999. The limits of detection(LOD) of twelve HBQs were lower than 2.0 ng/mL, and the limits of quantification(LOQ) for twelve HBQs were lower than 5.0 ng/mL, respectively. The recoveries of three levels in the matrix were 70.0%-84.0%. The matrix effffect was 0.08-0.64. CONCLUSION: The SPE-UPLC-MS/MS method has high sensitivity, good accuracy and fast analysis speed for the detection of halobenzoquinones in drinking water.

Distinct invasive patterns in situ between estrogen receptor-positive and triple-negative breast cancer through the intraductal tracking of carbon nanoparticles.

Given that the transition from ductal carcinoma in situ (DCIS) to invasive breast cancer (BC) is crucial during the BC progression, the mechanism involved in the invasion transition behind triple-negative breast cancer (TNBC) and estrogen receptor-positive (ER-positive) subtype has remained elusive. This article detected distinct invasion patterns of BC cells between the ER-positive and TNBC using intraductal murine models with intraductal administration of carbon nanoparticles (CNPs). First, the feasibility of the utility of CNPs as a tracer was proved. The area ratio of CNPs and tumor cells invading the stroma at the late stage was found significantly higher than that in the early stage in MNU-induced ER-positive BC. However, opposite results were obtained in the triple-negative model. Consequently, we proposed that the ER-positive phenotype cells behave differently between different stages during tumor progression while there is no such difference in the invasion process of TNBC cells. The analysis regarding the duct integrity along with immunohistochemical characteristics further explained the distinct invasion features between the ER-positive and triple-negative subtypes. Last, the relationship between the duct thickness and the duct integrity suggested that ER-positive tumors gradually increased in size within the lumen before the invasion. Overall, this study suggested the different invasion characteristics of ER-positive BC and TNBC in vivo.

Correlation of Intravoxel Incoherent Motion and Diffusion Kurtosis MR Imaging Models With Reactive Stromal Grade in Prostate Cancer.

BACKGROUND: Reactive stroma is recognized as one of the independent prognostic factors in prostate cancer (PCa). Intravoxel incoherent motion (IVIM) and diffusion kurtosis imaging (DKI) may be useful for assessing the reactive stromal grade (RSG). PURPOSE: To investigate whether IVIM and DKI models can evaluate RSG in PCa patients. STUDY TYPE: Retrospective. SUBJECTS: A total of 56 PCa patients aged 73 years on average confirmed by MRI and transrectal ultrasound (MRI/TRUS) fusion biopsy divided into two subgroups (18 high RSG and 38 low RSG). FIELD STRENGTH/SEQUENCE: A 3 T/T1 WI-fs, T1 WI, T2 WI-fs, T2 WI, DWI, IVIM, and DKI. ASSESSMENT: Apparent diffusion coefficient (ADC), pure diffusion coefficient (D), pseudo-diffusion coefficient (D*), perfusion fraction (f), mean diffusion (MD), mean kurtosis (MK) were obtained. Patients were divided into high RSG PCa (>50% reactive stroma) and low RSG PCa (≤50% reactive stroma) groups on hematoxylin and eosin (H&E) stained sections. STATISTICAL TESTS: Spearman correlation and independent sample t-test or Wilcoxon's rank sum test was used to investigate the relationship between each imaging parameter and RSG. The combined parameters were calculated using a binary logistic regression model. Receiver operating characteristic (ROC) analysis was used to explore the value of individual and combined parameters to differentiate between high and low RSG group. Area under the ROC curves (AUC) > 0.7 were used as reference standards. RESULTS: ADC, D, f, and MD values showed positive correlation with RSG (r = 0.489, 0.619, 0.318, and 0.544, respectively); MK showed negative correlation with RSG (r = -0.444). ADC, D, f, and MD values were significantly lower in the low RSG group than in the high RSG group. The combined model showed the best diagnostic ability to differentiate low and high RSG groups (AUC = 0.887). DATA CONCLUSION: Parameters of IVIM and DKI may be promising methods for assessment of RSG in PCa patients. EVIDENCE LEVEL: 3. TECHNICAL EFFICACY: Stage 3.

Pop Music Singing in Education with Modern Innovative Technologies: How the Chinese Language Shapes the Creation of Popular Singing.

The purpose of this study is to investigate the uniqueness of the pop singing genre by determining the role of the Chinese language in the creation of popular singing in education with modern innovative technologies. The paper began by determining which types of popular music were the most popular among respondents and the influence of modern innovative technologies on music education. The results showed that popular folk music (25%) and popular music (23%) are the most popular genres. This is because they are based on improvisational elements and combine modern and ethnic musical elements with the use of modern innovative technologies. Pentatonic preservation (94.3), modern innovative technologies (91.2), expressive performance (85.6), sound fluidity and mobility (82) and instrumental accompaniment have been identified as the most defining characteristics of contemporary Chinese popular music (78.1). Taking into account how pure and expressive Chinese music is, the study found that singing should take into account the following aspects of the Chinese language: the tonality of vowels, the influence of consonant sounds, the use of sound imitations, the performance of words with different levels of complexity, and the relationship between speech and musical intonation. It has been proven that students in group 1 who studied vocals and were taught the rules for combining phonetic features of language when singing had better results in terms of quality performance (0.83) and expressive performance (0.91). The non-professional singers in group 2 attained scores of 0.62 and 0.85, respectively.

[Determination of beauvercin and enniatins in rice flour and wheat flour by solid phase extraction-ultra performance liquid chromatography-tandem mass spectrometry].

OBJECTIVE: To develop a method for the determination of beauvercin(BEA), enniatin A(ENNA), enniatin A1(ENNA1), enniatin B(ENNB) and enniatin B1(ENNB1) in rice flour and wheat flour by ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS). METHODS: Samples were extracted by acetonitrile-water, purified by Oasis Prime HLB solid-phase extraction column. The sample solution was separated by waters BEH C_(18) column(2.1 mm×100 mm, 1.8 µm). The detection was performed in the electrospray positive ionization(ESI+) under multiple reaction monitoring(MRM) mode. The internal standard method and the matrix-matched calibrations were used for quantification. RESULTS: The linear relationships of BEA and 4 kinds of enniatins(ENNs) were good in the range of 0.1-50.0 ng/mL(r>0.999). The average recoveries of BEA and ENNs in rice flour and wheat flour were 96.4%-105.4% and 99.1%-109.2%, with the relative standard deviations(RSD) of 1.01%-7.42% and 1.09%-9.69%(n=6). The detection limits(LOD) of BEA and ENNs were 0.03 µg/kg. The quantitative limits(LOQ) of BEA and ENNs were 0.1µg/kg. The matrix induced suppression or enhancement effect were 72.7%-99.3% and 60.8%-100.4%, respectively. The levels of emerging BEA and ENNs in wheat flour were higher than rice flour. The detection rate of enniatin B was highest in wheat flour and rice flour, the contents were 0.03-9.57 µg/kg and 0.03-0.56 µg/kg, the positive percentage were 98.5% and 36.4%. CONCLUSION: The method is quick, easy, accurate and sensitive, which is suitable for the determination of BEA and 4 kinds of ENNs in rice flour and wheat flour.

Targeted inhibition of TXNRD1 prevents cartilage extracellular matrix degeneration by activating Nrf2 pathway in osteoarthritis.

Osteoarthritis, a prevalent orthopedic disease, can affect the elderly and causes impairment. The degradation and aberrant homeostasis of cartilage extracellular matrix figure pivotally in the progression of osteoarthritis. Thioredoxin systems plays a role in a wide range of biological processes, including cell proliferation, apoptosis, and oxidative stress. The present study aimed to investigate the unique function and underlying pathophysiological mechanism of TXNRD1 in chondrocytes. An upregulated expression of TXNRD1 was observed in the articular cartilage of osteoarthritis patients compared with normal articular cartilage. Furthermore, in vitro experiments showed that the expression of TXNRD1 was also abnormally increased in IL-1ß-induced primary mouse chondrocytes. Silencing TXNRD1 using siRNA in chondrocytes could effectively inhibit the expression of ADAMTS5 and MMP13, and enhance the expression of COL2A1 and SOX9. The same was true for auranofin, an inhibitor of TXNRD1. This phenomenon indicated that inhibition of TXNRD1 attenuated il-1ß-induced metabolic imbalance of extracellular matrix (ECM) and the progression of chondrocyte osteoarthritis. Further mechanism analysis revealed that the activation of Nrf2 signaling pathway and the expression of heme oxygenase-1 (HO-1) were increased upon TXNRD1 inhibition. Furthermore, auranofin was found to attenuate DMM-induced osteoarthritis progression in vivo. Therefore, the pharmacological downregulation of TXNRD1 may provide an effective novel therapy for OA.

Chondrogenic potential of manganese-loaded composite scaffold combined with chondrocytes for articular cartilage defect.

Cartilage is an alymphatic, avascular and non-innervated tissue. Lack of potential regenerative capacity to reconstruct chondral defect has accelerated investigation and development of new strategy for cartilage repair. We prepared a manganese ion-incorporated natupolymer-based scaffold with chitosan-gelatin by freeze-drying procedure. The scaffold was characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, energy dispersive spectroscopy, compressive testing, and analysis of porosity and flexibility. Live/dead assay confirmed the good cytocompatibility of prepared scaffold on rat articular chondrocytes after 10 days and 4 weeks of culture. The manganese-loaded composite scaffold upregulated the expression of chondrogenic-related markers (Sox9, integrin, and Col II) in chondrocytes. Western blot analysis of proteins extracted from chondrocytes grown on scaffolds indicated the signaling pathways of p-Akt and p-ERK1/2 played a key role. Histological analysis following implantation of current composite scaffold loaded with chondrocytes into a rat articular cartilage defect model showed that the scaffolds promoted the formation of collagen II and cartilage repair. These findings suggested the potential of manganese-loaded scaffold to promote new cartilage formation and a promising strategy for articular cartilage engineering application.

[Determination of vitamin A, vitamin E isomers and cholesterol in foods by reversed-phase high-performance liquid chromatography].

OBJECTIVE: To establish a method for simultaneous analysis of vitamin A, three vitamin E isomers and cholesterol in meat products by reversed-phase high-performance liquid chromatography. This method is used to determine the contents of the corresponding nutrients in several meat products. METHODS: The sample was pretreated with saponification and liquid-liquid extraction, then separated on Waters Symmetry C_(18) column(4.6 mm×250 mm, 5 µm). The mobile phase consisted of methanol(98%) and water(2%). The analytes were detected by photo-diode array(PDA)detector. 325 nm, 294 nm, and 210 nm were selected as the characteristic absorption wavelengths of vitamin A, vitamin E, and cholesterol, respectively by scanning in the range of 190-350 nm in 3 D mode. Benzo[e]pyrene was internal standard for vitamin A and E. Cholesterol was quantified by external standard curve method. RESULTS: The concentration of vitamin A, three vitamin E isomers and cholesterol showed good linearity in the range of 0.18-9.00 µg/mL、0.76-5.2 µg/mL and 0.11-5.50 mg/mL, respectively, with the correlation coefficients greater than 0.995.The limits of detections(LODs) were 5、20 and 330 µg/100 g and the limits of quantification(LOQs) for vitamin A, three vitamin E isomers and cholesterol were 15、60 and 990 µg/100 g, respectively. The recoveries at three levels in the matrix were 86.3%-105.6%, and the relative standard deviations(RSDs) were all less than 7.0%(n=6). CONCLUSION: The method is sensitive, accurate and suitable for analysis of vitamin A, three vitamin E isomers and cholesterol in meat products.

[Nutritional composition in different processed wheats from Shaanxi Province].

OBJECTIVE: To study the content of nutritive ingredients of 11 kinds of different processed wheats planted in Shaanxi Province, and assess their nutritional value. METHODS: The macronutrients, moisture, ash and vitamins in 11 different wheat were determined. The index of nutritional quality(INQ) method was used to evaluate the different nutrients in 11 kinds of wheat and the fuzzy membership function method was used to evaluate the nutritional value comprehensively. RESULTS: The contents of water and carbohydrate in 11 kinds of whole wheat flour were lower than those of special flour and wheat core flour. The contents of ash, fat, protein and total dietary fiber were significantly higher than those of special flour and wheat core flour. The wheat flour contained high levels of vitamin B_1, certain vitamin B_2 and trace amount of ß-carotene. Under the parameters selected in this article, the comprehensive evaluation shows that Jinmai 54 had the highest nutritive value among 11 kinds of wheat, while Zhoumai 26 had the lowest nutritive value. CONCLUSION: 11 kinds of wheat is rich in protein, vitamins and other nutrients, peeling can cause a large loss of vitamin B and vitamin E in wheat flour. The comprehensive nutritional value of whole wheat flour is higher than the special flour and wheat core powder.

Using a strong chemical oxidant, potassium ferrate (K2FeO4), in waste activated sludge treatment: A review.

The ever-increasing production of waste activated sludge (WAS) has become a widespread problem to sewage treatment plants around the world. Among the multitudinous sludge treatment methods, chemical oxidation is considered as an excellent technology with both high efficiency and low investment cost. As an eco-friendly oxidant, potassium ferrate (PF) has attracted great attention in sludge treatment over the past decade. The applications of PF have demonstrated advantages in: (1) sludge dewatering; (2) minimization; (3) anaerobic fermentation; (4) removal of pollutants. This review summarizes recent work on the effects of PF on these four aspects of facilitating sludge disposal. Meanwhile, the underlying mechanisms for the diverse applications of PF on sludge treatment are analyzed. Furthermore, the shortages and knowledge gaps on current PF oxidizing methods are discussed, and directions for further research to simultaneously enhance treatment efficiency and reduce processing cost are suggested as well.

Heme oxygenase-1 regulates autophagy through carbon-oxygen to alleviate deoxynivalenol-induced hepatic damage.

Deoxynivalenol (DON) cannot be totally removed due to its stable chemical characteristics and chronic exposure to low doses of DON causes significant toxic effects in humans and animals. However, the potential hazard of such low-dose exposure in target organs still remains not completely understood, especially in liver, which is mainly responsible for detoxification of DON. In the present study, we demonstrated for the first time that estimated human daily DON exposure (25 µg/kg bw) for 30 and 90 days caused low-grade inflammatory infiltration around hepatic centrilobular veins, elevated systemic IL-1ß, IL-6 and TNF-α and impaired liver function evidenced by increased serum ALT activity. At the molecular level, expressions of autophagy-related proteins as well as Cleaved Caspase-3 and Cleaved Caspase-7 were upregulated during DON exposure, which indicated the activation of autophagy and apoptosis. Importantly, AAV-mediated liver-specific overexpression of HO-1 reversed DON-induced liver damages, upregulated autophagy and attenuated apoptosis in liver, while AAV-mediated HO-1 silence aggravated DON-induced liver damages, inhibited autophagy and increased apoptosis. Furthermore, in vitro experiments demonstrated that lentivirus-mediated HO-1 overexpression in Hepa 1-6 cells prolonged the duration of autophagy and delayed the onset of apoptosis. HO-1 silence in Hepa 1-6 cells inhibited activation of autophagy and accelerated occurrence of apoptosis, and these could be recovered by CO pre-treatment. Therefore, we suppose that HO-1 might be a potential research target to protect human and animal from liver injuries induced by low dose of DON exposure.

The impact of climate change on residential energy consumption in urban and rural divided southern and northern China.

In different regions of China, climate change has various influences on urban and rural residential energy consumption, which also shows that the research on it could be profoundly vital in order to formulate the energy-saving and emission-reducing policies. Based the provincial panel data from 2000-2016, the extended stochastic impacts by regression on population, affluence, and technology (extended STIRPAT) model was utilized to evaluate the impacts of climate change on residential energy consumption in different Chinese regions. The results show that: (1) during 2000 to 2016, the urban and rural energy consumption enlarged by 878.83 billion kWh and 488.98 billion kWh, respectively. In addition, electricity and oil have occupied more proportion in urban energy consumption, while coal still plays an important role in rural residential energy consumption (28.2%). (2) Heating degree day (HDD) and cooling degree day (CDD) have positive influences on urban and rural residential energy consumption in different areas, and the elastic coefficients are 0.028-0.371 and 0.066-0.158, respectively. (3) The elastic coefficient of CDD in urban areas of southern regions (0.158) is much larger than that in northern regions (0.068).

[Determination of vitamin A and vitamin E in human serum by high performance liquid chromatography with fluorescence detection].

OBJECTIVE: To establish a method for the simultaneous and rapid determination of vitamin A and vitamin E of different configurations in human serum by high performance liquid chromatography(HPLC) with multi-wavelength fluorescence detector. METHODS: The serum was mixed after adding internal standard, and acetonitrile was added for protein precipitation. The mixture was centrifuged after extraction with n-hexane. The n-hexane layer was dried by N_2 flow, the residue was dissolved with methanol. The HPLC system was consisted of WATERS Symmetry C_(18) column(4. 6 mm × 250 mm, 5 µm) and the mobile phase was methanol. The column temperature was 30 ℃ and fluorescence detector with online wavelength conversion method was carried out for the quantitative detection. RESULTS: The liner range of determination of vitamin A, α-vitamin E, ß-vitamin E and δ-vitamin E were 0. 050-2. 0 µg/mL, 0. 50-50 µg/mL, 0. 050-5. 0 µg/mL and 0. 050-5. 0 µg/mL, respectively(r≥0. 996). The minimum detection limits of the method for vitamin A and vitamin E were all 0. 02 µg/mL. The intraday and interday relative standard deviations(RSDs) were less than 3% at high, medium and low concentrations. The recoveries of the samples at the three concentrations were 91. 2%-107. 5%, and the RSDs were less than 10%. CONCLUSION: This method is simple and accurate, with higher sensitivity than using UV detector and can be used for the simultaneous determination of vitamin A and vitamin E of different configurations in serum, and is suitable for rapid detection of batch serum samples.

[Simultaneous determination of 25-hydroxyvitamin D and vitamin K_1 in serum by ultra-performance liquid chromatography-tandem mass spectrometry].

OBJECTIVE: To establish a method for analysis of 25-hydroxylvitamin D_2(25(OH)D_2), 25-hydroxylvitamin D_3(25(OH)D_3)and vitamin K_1 in serum by ultra-performance liquid chromatography tandem mass spectrometry(UPLC-MS/MS), which can be applied in diagnosis of vitamin deficiency and estimation on the nutritional status of people. METHODS: Serum samples mixed with d_6-25(OH)D_3, d_7-vitamin K_1(internal standard)were precipitated with acetonitrile and extracted with n-hexane. The sample solution was separated using BEH C_(18) column(2. 1 mm×100 mm, 1. 7 µm) with gradient elution using methanol-water containing 0. 1% formic acid as mobile phase. The target molecule was detected in positive electrospray ionization(ESI~+) and multiple reaction monitoring. RESULTS: The concentration of 25(OH)D_2, 25(OH)D_3 and vitamin K_1 showed good linearity in the range 5. 0-75. 0 ng/mL, 2. 0-81. 5 ng/mL and 0. 3-12. 0 ng/mL, respectively, with the correlation coefficients greater than 0. 995. The limits of detection(LOD) of 25(OH)D_2, 25(OH)D_3 and vitamin K_1 were 1, 0. 25 and 0. 1 ng/mL, and the limits of quantification(LOQ) for 25(OH)D_2, 25(OH)D_3 and vitamin K_1were 3, 0. 75 and 0. 3 ng/mL, respectively. The recoveries of three levels in the matrix were 98. 5%-104. 3%, the relative standard deviation(RSD) were all less than 5. 0%(n=6). CONCLUSION: An UPLC-MS/MS method for analysis of 25(OH)D_2, 25(OH)D_3 and vitamin K_1 in serum is sensitive, rapid, accurate and suitable for the nutritional surveillance of vitamin D and K_1 in the population.