Precise Measurement of the e^{+}e^{-}→D_{s}^{*+}D_{s}^{*-} Cross Sections at Center-of-Mass Energies from Threshold to 4.95 GeV

The process e^{+}e^{-}→D_{s}^{*+}D_{s}^{*-} is studied with a semi-inclusive method using data samples at center-of-mass energies from threshold to 4.95 GeV collected with the BESIII detector operating at the Beijing Electron Positron Collider. The Born cross sections of the process are measured for the first time with high precision in this energy region. Two resonance structures are observed in the energy-dependent cross sections around 4.2 and 4.4 GeV. By fitting the cross sections with a coherent sum of three Breit-Wigner amplitudes and one phase-space amplitude, the two significant structures are assigned masses of (4186.8±8.7±30) and (4414.6±3.4±6.1)  MeV/c^{2}, widths of (55±15±53) and (122.5±7.5±8.1)  MeV, where the first errors are statistical and the second ones are systematic. The inclusion of a third Breit-Wigner amplitude is necessary to describe a structure around 4.79 GeV.

First Experimental Study of the Purely Leptonic Decay D_{s}^{*+}→e^{+}ν_{e}

Using 7.33  fb^{-1} of e^{+}e^{-} collision data taken with the BESIII detector at the BEPCII collider, we report the first experimental study of the purely leptonic decay D_{s}^{*+}→e^{+}ν_{e}. Our data contain a signal of this decay with a statistical significance of 2.9σ. The branching fraction of D_{s}^{*+}→e^{+}ν_{e} is measured to be (2.1_{-0.9_{stat}}^{+1.2}±0.2_{syst})×10^{-5}, corresponding to an upper limit of 4.0×10^{-5} at the 90% confidence level. Taking the total width of the D_{s}^{*+} [(0.070±0.028)  keV] predicted with the radiative D_{s}^{*+} decay from the lattice QCD calculation as input, the decay constant of the D_{s}^{*+} is determined to be f_{D_{s}^{*+}}=(214_{-46_{stat}}^{+61}±44_{syst})  MeV, corresponding to an upper limit of 354 MeV at the 90% confidence level.

Effect of artesunate on cardiovascular complications in periodontitis in a type I diabetes rat model and related mechanisms

PURPOSE

Both cardiovascular disease and periodontitis are complications of diabetes that have a great impact on human life and health. Our previous research found that artesunate can effectively improve cardiovascular disease in diabetes and has an inhibitory effect on periodontal disease. Therefore, the present study aimed to explore the potential therapeutic possibility of artesunate in the protection against cardiovascular complications in periodontitis with type I diabetes rats and to elucidate the possible underlying mechanisms.

METHODS

Sprague‒Dawley rats were randomly divided into the healthy, diabetic, periodontitis, diabetic with periodontitis, and artesunate treatment groups (10, 30, and 60 mg/kg, i.g.). After artesunate treatment, oral swabs were collected and used to determine changes in the oral flora. Micro-CT was performed to observe changes in alveolar bone. Blood samples were processed to measure various parameters, while cardiovascular tissues were evaluated by haematoxylin-eosin, Masson, Sirius red, and TUNEL staining to observe fibrosis and apoptosis. The protein and mRNA expression levels in the alveolar bone and cardiovascular tissues were detected using immunohistochemistry and RT‒PCR.

RESULTS

Diabetic rats with periodontitis and cardiovascular complications maintained heart and body weight but exhibited reduced blood glucose levels, and they were able to regulate blood lipid indicators at normal levels after artesunate treatment. The staining assays suggested that treatment with 60 mg/kg artesunate has a significant therapeutic effect on myocardial apoptotic fibrosis. The high expression of NF-κB, TLR4, VEGF, ICAM-1, p38 MAPK, TGF-β, Smad2, and MMP9 in the alveolar bone and cardiovascular tissue in the type I diabetes and type I diabetes with periodontitis rat models was reduced after treatment with artesunate in a concentration-dependent manner. Micro-CT showed that treatment with 60 mg/kg artesunate effectively alleviated alveolar bone resorption and density reduction. The sequencing results suggested that each model group of rats had vascular and oral flora dysbiosis, but artesunate treatment could correct the dysbacteriosis.

CONCLUSIONS

Periodontitis-related pathogenic bacteria cause dysbiosis of the oral and intravascular flora in type I diabetes and aggravate cardiovascular complications. The mechanism by which periodontitis aggravates cardiovascular complications involves the NF-κB pathway, which induces myocardial apoptosis, fibrosis, and vascular inflammation.

First Study of Reaction Ξ^{0}n→Ξ^{-}p Using Ξ^{0}-Nucleus Scattering at an Electron-Positron Collider

Using (1.0087±0.0044)×10^{10}  J/ψ events collected with the BESIII detector at the BEPCII storage ring, the process Ξ^{0}n→Ξ^{-}p is studied, where the Ξ^{0} baryon is produced in the process J/ψ→Ξ^{0}Ξ[over ¯]^{0} and the neutron is a component of the ^{9}Be, ^{12}C, and ^{197}Au nuclei in the beam pipe. A clear signal is observed with a statistical significance of 7.1σ. The cross section of the reaction Ξ^{0}+^{9}Be→Ξ^{-}+p+^{8}Be is determined to be σ(Ξ^{0}+^{9}Be→Ξ^{-}+p+^{8}Be)=(22.1±5.3_{stat}±4.5_{sys})  mb at the Ξ^{0} momentum of 0.818  GeV/c, where the first uncertainty is statistical and the second is systematic. No significant H-dibaryon signal is observed in the Ξ^{-}p final state. This is the first study of hyperon-nucleon interactions in electron-positron collisions and opens up a new direction for such research.

Measurements of Normalized Differential Cross Sections of Inclusive π^{0} and K_{S}^{0} Production in e^{+}e^{-} Annihilation at Energies from 2.2324 to 3.6710 GeV

Based on electron positron collision data collected with the BESIII detector operating at the BEPCII storage rings, the differential cross sections of inclusive π^{0} and K_{S}^{0} production as a function of hadron momentum, normalized by the total cross section of the e^{+}e^{-}→hadrons process, are measured at six center-of-mass energies from 2.2324 to 3.6710 GeV. Our results, which cover a relative hadron energy range from 0.1 to 0.9, significantly deviate from several theoretical calculations based on existing fragmentation functions.

Precision Measurement of the Decay Σ^{+}→pγ in the Process J/ψ→Σ^{+}Σ[over ¯]^{-}

Using (10 087±44)×10^{6} J/ψ events collected with the BESIII detector, the radiative hyperon decay Σ^{+}→pγ is studied at an electron-positron collider experiment for the first time. The absolute branching fraction is measured to be (0.996±0.021_{stat}±0.018_{syst})×10^{-3}, which is lower than its world average value by 4.2 standard deviations. Its decay asymmetry parameter is determined to be -0.652±0.056_{stat}±0.020_{syst}. The branching fraction and decay asymmetry parameter are the most precise to date, and the accuracies are improved by 78% and 34%, respectively.

Measurements of the Electric and Magnetic Form Factors of the Neutron for Timelike Momentum Transfer

We present the first measurements of the electric and magnetic form factors of the neutron in the timelike (positive q^{2}) region as function of four-momentum transfer. We explored the differential cross sections of the reaction e^{+}e^{-}→n[over ¯]n with data collected with the BESIII detector at the BEPCII accelerator, corresponding to an integrated luminosity of 354.6  pb^{-1} in total at twelve center-of-mass energies between sqrt[s]=2.0-2.95  GeV. A relative uncertainty of 18% and 12% for the electric and magnetic form factors, respectively, is achieved at sqrt[s]=2.3935  GeV. Our results are comparable in accuracy to those from electron scattering in the comparable spacelike region of four-momentum transfer. The electromagnetic form factor ratio R_{em}≡|G_{E}|/|G_{M}| is within the uncertainties close to unity. We compare our result on |G_{E}| and |G_{M}| to recent model predictions, and the measurements in the spacelike region to test the analyticity of electromagnetic form factors.

Observation of a New X(3872) Production Process e^{+}e^{-}→ωX(3872)

Using 4.7  fb^{-1} of e^{+}e^{-} collision data at center-of-mass energies from 4.661 to 4.951 GeV collected by the BESIII detector at the BEPCII collider, we observe the X(3872) production process e^{+}e^{-}→ωX(3872) for the first time. The significance is 7.8σ, including both the statistical and systematic uncertainties. The e^{+}e^{-}→ωX(3872) Born cross section and the corresponding upper limit at 90% confidence level at each energy point are reported. The line shape of the cross section indicates that the ωX(3872) signals may be from the decays of some nontrivial structures.

Observation of Three Charmoniumlike States with J^{PC}=1^{--} in e^{+}e^{-}→D^{*0}D^{*-}π^{+}

The Born cross sections of the process e^{+}e^{-}→D^{*0}D^{*-}π^{+} at center-of-mass energies from 4.189 to 4.951 GeV are measured for the first time. The data samples used correspond to an integrated luminosity of 17.9  fb^{-1} and were collected by the BESIII detector operating at the BEPCII storage ring. Three enhancements around 4.20, 4.47, and 4.67 GeV are visible. The resonances have masses of 4209.6±4.7±5.9  MeV/c^{2}, 4469.1±26.2±3.6  MeV/c^{2}, and 4675.3±29.5±3.5  MeV/c^{2} and widths of 81.6±17.8±9.0  MeV, 246.3±36.7±9.4  MeV, and 218.3±72.9±9.3  MeV, respectively, where the first uncertainties are statistical and the second systematic. The first and third resonances are consistent with the ψ(4230) and ψ(4660) states, respectively, while the second one is compatible with the ψ(4500) observed in the e^{+}e^{-}→K^{+}K^{-}J/ψ process. These three charmoniumlike ψ states are observed in the e^{+}e^{-}→D^{*0}D^{*-}π^{+} process for the first time.

Genome-wide identification and expression analysis of SlRR genes in response to abiotic stress in tomato

The cytokinin two-component signal transduction system (TCS) is involved in many biological processes, including hormone signal transduction and plant growth regulation. Although cytokinin TCS has been well characterized in Arabidopsis thaliana, its role in tomato remains elusive. In this study, we characterized the diversity and function of response regulator (RR) genes, a critical component of TCS, in tomato. In total, we identified 31 RR genes in the tomato genome. These SlRR genes were classified into three subgroups (type-A, type-B and type-C). Various stress-responsive cis-elements were present in the tomato RR gene promoters. Their expression responses under pesticide treatment were evaluated by transcriptome analysis. Their expression under heat, cold, ABA, salinity and NaHCO₃ treatments was further investigated by qRT-PCR and complemented with the available transcription data under these treatments. Specifically, SlRR13 expression was significantly upregulated under salinity, drought, cold and pesticide stress and was downregulated under ABA treatment. SlRR23 expression was induced under salt treatment, while the transcription level of SlRR1 was increased under cold and decreased under salt stress. We also found that GATA transcription factors played a significant role in the regulation of SlRR genes. Based on our results, tomato SlRR genes are involved in responses to abiotic stress in tomato and could be implemented in molecular breeding approaches to increase resistance of tomato to environmental stresses.

Reef islands have continually adjusted to environmental change over the past two millennia

Global environmental change is identified as a driver of physical transformation of coral reef islands over the past half-century, and next 100 years, posing major adaptation challenges to island nations. Here we resolve whether these recent documented changes in islands are unprecedented compared with the pre-industrial era. We utilise radiometric dating, geological, and remote sensing techniques to document the dynamics of a Maldivian reef island at millennial to decadal timescales. Results show the magnitude of island change over the past half-century (±40 m movement) is not unprecedented compared with paleo-dynamic evidence that reveals large-scale changes in island dimension, shape, beach levels, as well as positional changes of ±200 m since island formation ~1,500 years ago. Results highlight the value of a multi-temporal methodological approach to gain a deeper understanding of the dynamic trajectories of reef islands, to support development of adaptation strategies at timeframes relevant to human security.

[Surveillance of Aedes populations in Jiangsu Province in 2020]

OBJECTIVE

To investigate the seasonal Aedes population fluctuation and the resistance of Aedes populations to common insecticides in Jiangsu Province in 2020, so as to provide insights into vector-borne infectious diseases control.

METHODS

One village was randomly sampled from each of Xinbei District of Changzhou City and Zhangjiagang County of Suzhou City in southern Jiangsu Province, Hai'an County of Nantong City and Yandu District of Yancheng City in Central Jiangsu Province, and Suining County of Xuzhou City and Sihong County of Suqian City in northern Jiangsu Province during the period between May and October, 2020. A small ponding container was sampled, and larval Aedes mosquitoes were collected using straws once each in early and late stages of each month. All larvae were bred in laboratory to adults for population identification. In addition, larval breeding were observed in all small ponding containers in and out of 30 households that were randomly sampled from six surveillance sites, and the larval mosquito density was estimated using Breteau index. Larval A. albopictus mosquitoes were sampled around Cuiyuan New Village in Jintan District of Changzhou City, and bred in laboratory to the first offspring generation, and the susceptibility of adult female mosquitoes to deltamethrin, lambda-cyhalothrin, malathion, and propoxur was tested using the filter-paper bioassay recommended by WHO.

RESULTS

A total of 1 165 larval Aedes mosquitoes were captured from small ponding containers in six surveillance sites of Jiangsu Province in 2020, and all were identified as A. albopictus following eclosion. The largest number of Aedes larvae captured was found in July. A total of 1 152 households were investigated in six surveillance sites, and the mean Breteau indexes were 9.58, 13.20, 13.71, 13.20, 12.18 and 5.58 from May to October, respectively, while a high Aedes transmission risk was seen in Xinbei District of Changzhou City, with a higher Breteau index than in Suining (H = 23.667, P_adjusted = 0.001) and Sihong (H = 22.500, P_adjusted = 0.003) counties. The field-captured A. albopictus from Cuiyuan New Village in Jintan District of Changzhou City remained sensitive to malathion, but was resistant to propoxur, and developed high-level resistance to deltamethrin and lambda-cyhalothrin.

CONCLUSIONS

A. albopictus was present in southern, central and northern Jiangsu Province in 2020, and the larval density peaked in July. A. albopictus captured from Cuiyuan New Village in Jintan District of Changzhou City has developed high-level resistance to pyrethroid pesticides.

[Considerations on pathological diagnosis of inherited metabolic liver disease]

A liver biopsy has an important suggestive role in the diagnosis of inherited metabolic liver disease (IMLD). This article introduces the IMLD pathological diagnosis considerations, five types of classification of liver biopsy based on the morphological characteristics (basic normal liver tissue morphology, steatosis, cholestatic disease, storage/deposition, and hepatitis), and a summary of the pathological characteristics of different injury patterns and common diseases in order to provide clues for the correct diagnosis.

[Introduction to the recommendations from the European Association for the Study of the Liver clinical practice guidelines on the management of cystic liver disease]

The diagnosis of cystic liver disease has made great progress with the advent of enhanced imaging techniques. At the same time, its management has gradually improved over the past few decades, providing the basis for the development of appropriate diagnostic and treatment guidelines. To this end, the European Association for the Study of the Liver has developed clinical guidelines for the diagnosis and treatment of non-infectious cystic liver disease. This guideline put forward recommendations based on an in-depth review of the relevant literature for addressing clinical issues, including the diagnosis and treament of hepatic cysts, hepatic mucocystic tumors, biliary hamartomas, polycystic liver disease, Caroli disease or Caroli syndrome, biliary hamartomas, and peribiliary cyst.

[Evaluation of the effectiveness of malaria control health education among overseas enterprise employees]

OBJECTIVE

To evaluate the effectiveness of health education on knowledge, attitude and practice (KAP) relating to malaria control among overseas enterprise employees.

METHODS

In September 2019, on-site malaria control health education was conducted among all Chinese employees of a China-funded mining enterprise in the Democratic Republic of Congo. The KAP questionnaire for malaria control was generated on the Questionstar website, and the participants were subjected to two questionnaire surveys prior to and 14 months after health education. After the questionnaires were recovered, all valid questionnaires were divided into 4 groups, including the baseline group (the questionnaires filled out by respondents who received health education and participated in two questionnaire surveys before health education), the loss-to-follow-up group (the questionnaires filled out by respondents who received health education but only participated in the questionnaire survey after health education), the retest group (the questionnaires filled out by respondents who received health education and participated in two questionnaire surveys after health education) and the new group (questionnaires filled out by respondents who did not receive health education and only participated in the questionnaire survey after health education) according to subjects' receiving health education and participation in two questionnaire surveys. The correct rate of malaria control knowledge, the proportion to good attitudes towards malaria control and the proportion of good practices towards malaria control were compared between the baseline group and the loss-to-follow-up group, between the baseline group and the retest group, and between the retest group and the new group.

RESULTS

A total of 110 and 142 valid questionnaires were recovered during the two surveys, and the recovery rates were 90.9% and 70.3%, respectively. There were 77, 77, 33, and 65 valid questionnaires recovered from the baseline group, the loss-to-follow-up group, the retest group, and the new group, respectively. There were no significant differences in respondents' gender, age and educational levels between the baseline group and the loss-to-follow-up group (all P values > 0.05), and there were no significant differences between the two groups in terms of the mean score of malaria control knowledge (Z = 2.011, P > 0.05), the mean score of attitudes towards malaria control (t = -0.787, P > 0.05) and the mean score of practices towards malaria control (t = -0.787, P > 0.05). There were significant differences between the retest group and the baseline group in terms of the mean score of malaria control knowledge (10.83 vs. 9.79; Z = -4.017, P < 0.05), the mean score of attitudes towards malaria control (29.48 vs. 28.61; Z = -1.981, P < 0.05) and the mean score of practices towards malaria control (6.43 vs. 5.91; Z = -2.499, P < 0.05). There were no significant differences between the retest group and the new group in terms of gender, age or education levels (all P values > 0.05), and a higher mean score of malaria control knowledge was found in the retest group than in the new group (10.83 vs. 9.81; Z = -2.962, P < 0.05), while no significant differences were seen in the mean score of attitudes towards malaria control (29.48 vs. 30.17; Z = -1.158, P > 0.05) and the mean score of practices towards malaria control (6.43 vs. 6.37; Z = -0.048, P > 0.05) between the two groups.

CONCLUSIONS

Malaria control health education may significantly improve the understanding of malaria control knowledge, positive attitudes towards malaria control and the compliance of practices towards malaria control among overseas enterprise employees.

[Research progress on the application of time-restricted eating in adult obesity and related metabolic diseases]

The soaring prevalence of obesity and its complications presents a significant health care burden, and there is currently a lack of effective and sustainable treatment methods. Time-restricted eating (TRE) is a specific intermittent fasting (IF) protocol involving consistent fasting and eating periods within a 24-hour cycle. Time-restricted eating can restore robust circadian rhythms and improve metabolic health, providing an emerging dietary strategy for the prevention and treatment of obesity and related metabolic diseases. Previous TRE trials laid the groundwork, and indicate a need for further clinical research including large-scale controlled trials to determine TRE efficacy and the mechanisms by which it may affect humans.

BMSC-Derived ApoEVs Promote Craniofacial Bone Repair via ROS/JNK Signaling

Bone defect caused by trauma, neoplasia, congenital defects, or periodontal disease is a major cause of disability and physical limitation. The transplantation of bone marrow mesenchymal stem cells (BMSCs) promotes bone repair and regeneration. However, it has been shown that most BMSCs die within a short period after transplantation. During apoptosis, BMSCs generate a large number of apoptotic cell-derived extracellular vesicles (ApoEVs). This study aims to understand the potential role of ApoEVs in craniofacial bone defect repair and regeneration. First, we confirmed that BMSCs undergo apoptosis within 2 d after transplantation into the defect of the cranium. Abundant ApoEVs were generated from apoptotic BMSCs. Uptake of ApoEVs efficiently promoted the proliferation, migration, and osteogenic differentiation of recipient BMSCs in vitro. ApoEVs from cells in the middle stage of apoptosis were the most efficient to enhance the regenerative capacity of BMSCs. Moreover, a critical size bone defect model in rats was used to evaluate the osteogenic property of ApoEVs in vivo. Local transplantation of ApoEVs promoted bone regeneration in the calvarial defect. Mechanistically, ApoEVs promoted new bone formation by increasing intracellular reactive oxygen species to activate JNK signaling. This study reveals a previously unknown role of the dying transplanted BMSCs in promoting the viability of endogenous BMSCs and repairing the calvarial defects. Since it could avoid several adverse effects and limits of BMSC cytotherapy, treatment of ApoEVs might be a promising strategy in craniofacial bone repair and regeneration.

[Identification of New Psychoactive Tryptamines 4-OH-MET and 4-AcO-DMT Using High Resolution Mass Spectrometry and Nuclear Magnetic Resonance Spectroscopy]

Abstract

Objective To detect the uncontrolled new psychoactive tryptamines involved in drug-related cases with high resolution mass spectrometry and nuclear magnetic resonance spectroscopy. Methods White and brown powder obtained in actual cases were extracted and analyzed by gas chromatography-quadrupole time-of-flight mass spectrometry （GC-QTOF-MS）, ultra-high performance liquid chromatography-linear ion trap quadrupole-orbitrap mass spectrometry （UPLC-LTQ-Orbitrap MS） and ¹H-nuclear magnetic resonance spectroscopy （1H-NMR）. Results After detection by GC-QTOF-MS, the components of white powder showed main characteristic fragment ion peaks at m/z 218.141 0 （molecular ion peak）, 72.080 6 （base peak）, etc. After detection by UPLC-LTQ-Orbitrap MS, its protonated molecular ion was m/z 219.149 4. The main ions in the secondary mass spectrum under the collision-induced dissociation （CID） mode were m/z 160.076 3 and 72.080 8. After detection by GC-QTOF-MS, the components of brown powder showed main characteristic fragment ion peaks at m/z 246.135 7 （molecular ion peak）, 58.065 1 （base peak）, etc. After detection by UPLC-LTQ-Orbitrap MS, its protonated molecular ion was m/z 247.145 0. The main ions in the secondary mass spectrum under CID mode were m/z 202.087 1, 160.076 3 and 134.060 5. NIST 17 library retrieval and ¹H-NMR confirmed that the white powder and brown powder contained new psychoactive tryptamines 4-OH-MET and 4-AcO-DMT, respectively. Conclusion GC-QTOF-MS, UPLC-LTQ-Orbitrap MS and ¹H-NMR can be used together to identify unknown new psychoactive substances.

[Surveillance of Culex mosquitoes in Jiangsu Province from 2018 to 2019]

OBJECTIVE

To investigate the distribution and density of Culex mosquito populations and the resistance of Culex pipiens pallens to insecticides in Jiangsu Province in 2018 and 2019.

METHODS

During the period from June to October in 2018 and 2019, six counties (districts, cities) were sampled in southern, northern and central Jiangsu Province as surveillance sites. The density of Culex mosquitoes was measured overnight using the light trapping technique. In addition, Culex pipiens pallens mosquitoes were collected from Hai'an of Nantong City and Yandu District of Yancheng City, central Jiangsu Province, and the sensitivity of female first filial generations to dichlorodiphenyltrichloroethane (DDT), malation, proposur, beta cypermethrin and deltamethrin was tested using the standard WHO insecticide susceptibility test assay.

RESULTS

A total of 104 423 Culex mosquitoes were captured in six surveillance sites of Jiangsu Province in 2018 and 2019, and Culex quinquefasciatus (49.11%), Culex pipiens pallens (28.38%), and Culex tritaeniorhynchus (21.04%) were predominant species. The density of Culex mosquitoes started to increase since early June, peaked in July and tended to be low in late October. Culex pipiens pallens mosquitoes captured from Hai'an was susceptible to malation, while those from Yandu District were moderately resistant to malation. Culex pipiens pallens mosquitoes from both Yandu and Hai'an were moderately resistant to proposur, and were resistant to DDT, beta cypermethrin and deltamethrin.

CONCLUSIONS

Culex quinquefasciatus, Culex pipiens pallens and Culex tritaeniorhynchus are predominant Culex species in Jiangsu Province. Culex pipiens pallens is resistant to DT, beta cypermethrin and deltamethrin in central Jiangsu Province.

[Study on emergency metabolic changes of Anopheles sinensis larvae following exposure to deltamethrin]

OBJECTIVE

To analyze the changes of small molecular metabolites in the larvae of a deltamethrin-sensitive strain of Anopheles sinensis following exposure to deltamethrin, so as to provide the scientific basis for investigating the metabolic pathway and screening metabolic markers of deltamethrin in An. sinensis.

METHODS

The 50% and 75% lethal concentrations (LC₅₀ and LC₇₅) of deltamethrin against the larvae of a deltamethrin-sensitive strain of An. sinensis were calculated in laboratory. The type and content of An. sinensis larvae metabolites were detected using high performance liquid chromatography and mass spectrometry (LC-MS/MS) following exposure to deltamethrin at LC₅₀ and LC₇₅ for 30 min and 24 h, and the changes of metabolites were analyzed.

RESULTS

The LC₅₀ and LC₇₅ values of deltamethrin were 4.36 × 10^-3 µg/mL and 1.12 × 10^-2 µg/mL against thelarvae of a deltamethrin-sensitive strain of An. sinensis. Following exposure of the larvae of a deltamethrin-sensitive strain of An. sinensis to deltamethrin at LC₅₀ and LC₇₅ for 30 min, the differential metabolites mainly included organic oxygen compounds, carboxylic acid and its derivatives, fatty acyl and pyrimidine nucleotides, with reduced glucose levels. Following exposure for 24 h, the differential metabolites mainly included organic oxygen compounds, carboxylic acid and its derivatives, aliphatic acyl and purine nucleotides, with increased glucose level detected.

CONCLUSIONS

Carbohydrate, carboxylic acid and its derivatives, fatty acyls, amino acids and their derivatives may play important roles in deltamethrin metabolism in the larvae of a deltamethrin-sensitive strain of An. sinensis.

Determination of Azide Ions in Blood by Pentafluorobenzyl Derivation Followed by GC-MS

Abstract

Objective To establish a method for determination of the azide ions in blood by gas chromatography-mass spectrometry （GC-MS） following pentafluorobenzyl derivatization. Methods A blood sample of 0.2 mL was placed into a 10 mL glass test tube, and the internal standard sodium cyanide, derivatization reagent pentafluorobenzyl bromide and catalyst tetradecyl benzyl dimethyl ammonium chloride were added in turn. After vortex mixing, the mixture was heated with low-power microwave for 3 min. After centrifugation, the organic phase was taken for GC-MS analysis. Results The azide ions in blood had a good linear relationship in the mass concentration range of 0.5 to 20 μg/mL. The lowest detection limit was 0.25 μg/mL and the relative recovery was 91.36%-94.58%. The method was successfully applied to a case of death from sodium azide poisoning. The mass concentration of azide ions in the blood of the dead was 11.11 μg/mL. Conclusion The method developed in this paper has strong specificity and is easy to operate, which is suitable for the rapid detection of azide ions in blood.