Single-port endoscopic-sentinel lymph node biopsy combined with indocyanine green and carbon nanoparticles in breast cancer.

BACKGROUND: In order to explore the surgical safety and the reliability of axillary staging of single-port endoscopic-sentinel lymph node biopsy, we combined it with indocyanine green that was excited by near-infrared fluorescence endoscopy and carbon nanoparticles as a tracer and compared this method to conventional open sentinel lymph node biopsy. METHODS: This is a retrospective and observational study, there were 20 patients in each group and the total sample size was 60: Group 1, single-port endoscopic-sentinel lymph node biopsy combined with indocyanine green and carbon nanoparticles; Group 2, single-port endoscopic-sentinel lymph node biopsy with carbon nanoparticles only; Group 3, conventional sentinel lymph node biopsy with indocyanine green and carbon nanoparticles. Sentinel lymph node detection and upper extremity function were determined to measure the safety and efficacy of the novel single-port endoscopic-sentinel lymph node biopsy (SPE-SLNB) technique to the standard conventional sentinel lymph node biopsy technique. RESULTS: The detection rate of sentinel lymph nodes was 100% in Group 1, 100% in Group 2, and 95% in Group 3. There were no significant differences in upper arm function and pain scores between the three groups. CONCLUSION: The novel technique of combining indocyanine green and carbon nanoparticles with single-port endoscopic-sentinel lymph node biopsy achieved a similar detection rate and mean number of sentinel lymph nodes as conventional sentinel lymph node biopsy. Traditional open surgery requires two different incisions for breast surgery and SLNB. While the most important advantage of SPE-SLNB is that two procedures can be effectively performed through a single-port in the axilla Therefore, for patients who meet the indications, single-port endoscopic-sentinel lymph node biopsy is as safe and reliable as conventional sentinel lymph node biopsy but has the aesthetic advantage of only one incision.

Analysis on Legal Relationship Based on a Typical Case of Medical Device Clinical Trial / 中国医学伦理学

Guaranteeing the rights and safety of subjects is an important responsibility of all participants in the medical devices clinical trial, including medical institutions, sponsors and researchers. The legal disputes caused by serious adverse events in the clinical trial of medical devices are characterized by complex legal relationships, great difficulty in handling, and many points of dispute. Based on a typical case of medical device clinical trials, this paper discussed the litigation subject qualification, the treatment of contract breach and tort in medical device clinical trial, analyzed the responsibility of different subjects, and provided constructive suggestions on the risk management of medical device clinical trial.

Analysis for trends in disease burden of congenital birth defects among children under 5 years old in China / 中南大学学报(医学版)

OBJECTIVES@#Congenital birth defects are the main source of disease burden among children under 5 years old in China. This study aims to compare the trends in disease burden of different congenital birth defects among Chinese children under 5 years old from 1990 to 2019, and to provide a scientific basis for strengthening the comprehensive prevention and control of birth defects.@*METHODS@#Based on data from the Global Burden Disease (GBD) in 2019, the incidence mortality rate, and disability-adjusted life years (DALYs) rate of congenital birth defects among Chinese children under 5 years old from 1990 to 2019 were selected as evaluation indicators. The Joinpoint regression model was used to analyze the trends in disease burden of different types with congenital birth defects over three decades. The study also compared the differences in disease burden of congenital birth defects among children under 5 years old by gender.@*RESULTS@#Compared to 1990, the DALYs rates of congenital heart anomalies (1 931.91/100 000), digestive congenital anomalies (364.63/100 000), neural tube defects (277.20/100 000), congenital musculoskeletal and limb anomalies (133.33/100 000), and Down syndrome (128.22/100 000) in children under 5 years old in China in 2019 were decreased 70.78%, 71.61%, 86.21%, 36.84% and 73.65%, respectively. From 1990 to 2019, the mortality rates and DALYs rates of different congenital birth defects showed an overall downward trend, but the incidence of digestive congenital anomalies and Down syndrome showed an upward trend after 2005 and 2001, respectively. Except for congenital musculoskeletal and limb anomalies, incidence of the remaining categories of birth defects were higher in boys than that in girls.@*CONCLUSIONS@#The disease burden of congenital birth defects in children under 5 years old in China is decreased substantially from 1990 to 2019, but the burden of congenital heart anomalies is still serious and the incidence of some birth defect diseases is on the rise, and it is still crucial to strengthen the prevention and treatment for birth defects in children and propose targeted measures according to their gender characteristics.

Comparing outcomes of single-port insufflation endoscopic breast-conserving surgery and conventional open approach for breast cancer.

BACKGROUND: In the surgical treatment of breast cancer, the goal of surgeons is to continually create and improve minimally invasive surgical techniques to increase patients' quality of life. Currently, routine breast-conserving surgery is often performed using two obvious incisions. Here, we compare the clinical efficacy and aesthetic outcomes of a novel technique using one incision, called 'single-port insufflation endoscopic breast-conserving surgery' (SIE-BCS), vs. conventional breast-conserving surgery (C-BCS) in patients with early-stage breast cancer. METHODS: A total of 180 patients with stage I or stage II breast cancer participated in this study, of whom 63 underwent SIE-BCS and 117 underwent C-BCS. Logistic regression analysis was conducted to assess the risk of local recurrence and metastasis. Aesthetic outcomes were evaluated using the BREAST-Q scale. RESULTS: The mean operation time was significantly longer for SIE-BCS (194.9 ± 71.5 min) than for C-BCS (140.3 ± 56.9 min), but the mean incision length was significantly shorter for SIE-BCS than for C-BCS (3.4 ± 1.2 cm vs. 8.6 ± 2.3 cm). While both surgeries yielded similar BREAST-Q ratings for satisfaction with breasts and sexual well-being, SIE-BCS was associated with significantly better ratings for physical well-being (chest area) and psychological well-being. Additionally, SIE-BCS was associated with decreased rates of adverse effects of radiation. The preliminary analysis showed that SIE-BCS did not increase the risk of local recurrence or metastasis. CONCLUSION: The novel single-port insufflation endoscopic assisted BCS technique is feasible, safe, and improves patients' postoperative comfort and psychological well-being, as compared to the conventional technique.

Oncological outcome of single-port insufflation endoscopic nipple-sparing mastectomy versus open mastectomy in early breast cancer patients: a study protocol for a randomised controlled trial.

INTRODUCTION: Breast cancer is the most prevalent cancer and the leading cause of cancer-related death in women. Conventional open mastectomy (C-OM) is one of the most common procedures for breast cancer, which involves the removal of the nipple-areola complex and a large proportion of the breast skin, leading to poor cosmetic effect and restriction of upper extremity function. Single-port insufflation endoscopic nipple-sparing mastectomy (SIE-NSM) could conceal the incision along the wrinkles in the axilla, preserve all the breast skin and nipple-areola complex and provide a better cosmetic outcome and quality of life. This trial aims to investigate the oncological safety between SIE-NSM and C-OM in early breast cancer patients. METHODS AND ANALYSIS: This is a single centre, non-blinded, randomised controlled trial (RCT) and will be conducted at Beijing Friendship Hospital. Patients will be enrolled in the inpatient ward. Breast surgeons will notify patients who meet the inclusion and exclusion criteria with the instruction of this RCT. Patients will be randomly assigned to C-OM or SIE-NSM with a 3:1 allocation as per a computer-generated randomisation schedule. Patients will be followed-up for 12 months for analysing surgical outcomes. The primary outcome is the local recurrence rate at a 12-month follow-up. The secondary outcome is the distant metastasis rate, cosmetic satisfaction score and psychosocial well-being score after a 12-month follow-up. To ensure the accuracy of the cosmetic satisfaction score and psychosocial well-being score, the standard scale, Breast-Q score, will be applied. ETHICS AND DISSEMINATION: This study will be conducted according to the medical ethics committee of the Beijing Friendship Hospital and according to the principles of the Declaration of Helsinki. All patients will receive clear instruction of their disease and treatment plan. Informed consent will be obtained from all patients when they agree to comply with our research plan. The results will be disseminated at academic presentations and publications in peer-reviewed journals. The raw data will be confidentially stored in our electronic data capture database. Data will not be shared unless an appropriate data request is submitted after the trial completion and peer-review journal publication. TRIAL REGISTRATION NUMBER: NCT04461847.

Recent global warming as a proximate cause of deforestation and forest degradation in northern Pakistan.

Instrumental climatological records such as weather stations data of northern areas of Pakistan are not sufficient to assess the forest extreme events reliably. To understand the past climatic variability, tree ring width based climatic reconstruction is the best alternative to trace climate variability that goes back in time. Quercus Incana is the most sensitive species to drought and climatic variation in northern Pakistan. However, very little research quantifies the rate of ongoing climatic changes. A total of 65 tree cores were collected from two sites to understand the radial growth of Q. Incana to extreme drought events. The radial growth is mainly affected by high temperatures during May-July. In addition, radial growth exhibits a positive correlation with February-June precipitation while it is negatively correlated with the September precipitation. The radial growth decrease, particularly in harsh climatic conditions. The reconstructed tree ring record was strongly coherent with the May-June self-calibrated Palmer drought severity index (scPDSI) and reliable in reconstructing drought variability for the period 1750-2014. During the past 264 years, wet periods were found during 1980-2010, 1812-1836, and 1754-1760, while dry periods were found during 1896-1922, 1864-1876, and 1784-1788. Our reconstruction explains 39.8% of the scPDSI variance. The extreme drought and wet years we arrived at were in close agreement with the drought and wet periods that occurred in northern Pakistan. Wavelet analysis revealed drought variability at periodicities of 2.2-2.5, 3.3, 3-4, 16.7, 16.8, and 68-78.8 years. Hence it is concluded that deforestation and forest degradation rate increased with extreme drought and wet years. Overall, the variation of drought in northern Pakistan seems to have been affected due to El Nino south oscillation, Pacific decadal oscillation, or Atlantic multi-decadal oscillations.

Human Umbilical Cord Mesenchymal Stem Cells Improve the Necrosis and Osteocyte Apoptosis in Glucocorticoid-Induced Osteonecrosis of the Femoral Head Model through Reducing the Macrophage Polarization

Background and Objectives@#Apoptosis is an outstanding determinant of glucocorticoid (GC)-induced osteonecrosis of the femoral head (ONFH). Human umbilical cord mesenchymal stem cells (hUC-MSCs) have been demonstrated to be associated with apoptosis in diseases models. However, the role of hUC-MSCs in GC-induced ONFH via regulating apoptosis still needs further study. @*Methods@#and Results: In the present study, a GC-induced ONFH model was built in vivo through a consecutive injection with lipopolysaccharide (LPS) and methylprednisolone. The necrosis and apoptosis of the femoral head was evaluated by histological and Terminal-deoxynucleoitidyl Transferase Mediated Nick End Labeling (TUNEL) assay. The level of collagen and TRAP positive cells were determined by Masson and TRAP staining, respectively. M1 macrophage polarization was assessed using immunofluorescence assay. The level of proinflammatory cytokines including tumor necrosis factor (TNF)‐α, Interleukin (IL)‐1β and IL-6 of femoral head was determined by enzyme-linked immunosorbent assay (ELISA) kits. The protein expression of AKT, mTOR, p-AKT and p-mTOR was detected using western blot assay. The results showed that hUC-MSCs treatment prominently promoted the GC-induced the decrease of the collagen level and the increase of TRAP positive cells. Besides, hUC-MSCs treatment decreased necrosis and apoptosis, macrophage polarization, the level of TNF‐α, IL‐1β and IL-6, the protein expression of p-AKT and p-mTOR, and the radio of p-AKT to AKT and p-mTOR to mTOR of femoral head in vivo. @*Conclusions@#Therefore, the present study revealed that hUC-MSCs improved the necrosis and osteocyte apoptosis in GC-induced ONFH model through reducing the macrophage polarization, which was associated with the inhibition of AKT/mTOR signaling pathway.

Epidemiological and clinical characteristics of pediatric lower extremity amputation and functional rehabilitation / 中国康复理论与实践

ObjectiveTo analyze the epidemiological and clinical characteristics of children's lower extremity amputation and amputation rehabilitation, and to explain the causes of children's amputation and the complications after amputation. MethodsFrom January, 2016 to March, 2021, 51 amputation related children were retrospectively analyzed. The correlation between the cause of amputation and complications post amputation were analyzed. ResultsTraumatic amputations accounted for 58.82%, and the main cause was traffic accidents (70%). Amputations caused by diseases accounted for 41.18%, and the main cause was congenital limb deformities (80.95%). Traumatic amputation was more likely to have stump complications than expected (P < 0.05). The possibility of stump complications after disease-specific amputation was lower than expected (P < 0.05). ConclusionTraffic trauma is the main cause of amputation in children and is characterized clinically by a high incidence of unsatisfactory stumps, mainly due to soft tissue abnormalities, and most cases require stump revision to improve the poor residuals for prosthetic restoration of ambulation. Congenital pseudarthrosis of the tibia is the main cause of disease-specific amputation, and the outcome of amputation often cannot be definitely avoided even after long-term limb preservation treatment.

The mechanism of action of Pudilan Xiaoyan oral liquid against LPS-induced acute respiratory infection in mice based on biological network analysis and metabolomics / 药学学报

This study integrates metabolomics and network pharmacology techniques to systematically analyze the possible mechanism of Pudilan Xiaoyan oral liquid (PDL) in the treatment of acute respiratory infections. GC-MS metabolomics analysis found 8 endogenous metabolites, 3-phosphoglycerate, α-aminoadipate, D-ribulose-5-phosphate, β-mannosylglyceric acid, D-fructose, urea, D-maltose and ornithine in the serum of mice with acute respiratory infection induced by LPS; these substances can be used as biomarkers for PDL use in the treatment of acute respiratory infections. Biological network studies revealed 10 potential targets for intervention by PDL in the glycolysis and pentose phosphate pathways, including GPI, G6PD, H6PD, PFKM, TALDO1, TKT, GAPDH, HK1, PKLR and TPI1. All animal experiments were carried out with approval of the Animal Ethics Committee of Nanjing University of Chinese Medicine. Our findings indicate that the strategy of combining metabolomics and network analysis can provide information on the possible mechanism of PDL in acute respiratory infections, and reveal that PDL may ameliorate the pathological process of acute respiratory infections by regulating disordered metabolic pathways.

Rational design and synthesis of magnetic covalent organic frameworks for controlling the selectivity and enhancing the extraction efficiency of polycyclic aromatic hydrocarbons.

A series of three-dimensional magnetic covalent organic frameworks were designed and synthesized via monomer selection, coating thickness optimization, and composite strategy transformation. Their structure properties including morphology, functional group, surface area, and pore size were characterized. The relationship between the structural properties and analytical performance was systematically investigated by density functional theory calculation and batch extraction experiments for polycyclic aromatic hydrocarbons. It is proven that the extractant modified by monomer 1,4-phthalaldehyde provides a hizgh affinity for high molecule weight polycyclic aromatic hydrocarbons and the right balance between extraction and elution efficiency. The relationship between coating thickness and mass transfer rate of polycyclic aromatic hydrocarbons was studied by accurate tuning of coating layers via layer-by-layer method. A mathematical model was derived and employed to determine that two coating layers were sufficient to provide the highest extraction efficiency with the shortest equilibrium time. The extractants synthesized by two different composite strategies (layer-by-layer and one-step) show opposite selectivity for polycyclic aromatic hydrocarbons. After optimization of the extraction conditions, dispersed solid-phase extraction coupled with gas chromatography-mass spectroscopy method was developed providing a wide linear range (5-500 ng L-1), good linearity (R2 > 0.9923), high precision in intra-day (RSD% < 8.2%) and inter-day (RSD% < 12.3%) detection, and low detection limits (1.5-15.1 ng L-1). The method was applied to the simultaneous determination of 16 polycyclic aromatic hydrocarbons with acceptable recoveries, which were 87-109% for groundwater, 83-116% for East Lake water, and 82-116% for Yangtze River water samples.

Gastrointestinal involvement of COVID-19 and potential faecal transmission of SARS-CoV-2 / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was found initially in Wuhan, China in early December 2019. The pandemic has spread to 216 countries and regions, infecting more than 23310 000 people and causing over 800 000 deaths globally by Aug. 24, 2020, according to World Health Organization (https://www.who.int/emergencies/diseases/ novel-coronavirus-2019). Fever, cough, and dyspnea are the three common symptoms of the condition, whereas the conventional transmission route for SARS-CoV-2 is through droplets entering the respiratory tract. To date, infection control measures for COVID-19 have been focusing on the involvement of the respiratory system. However, ignoring potential faecal transmission and the gastrointestinal involvement of SARS-CoV-2 may result in mistakes in attempts to control the pandemic.

Eco-friendly and facile one-step synthesis of a three dimensional net-like magnetic mesoporous carbon derived from wastepaper as a renewable adsorbent.

Millions of tons of paper and its derivatives are annually wasted without being recycled and reused. To promote the comprehensive utilization of resources and eco-friendly preparation, waste filter paper, printer paper, and napkins were chosen as carbon sources to one-step synthesize three types of three dimensional (3D) net-like magnetic mesoporous carbon (MMC) by an eco-friendly and low-cost method. These mesoporous (3.90-7.68 nm) composites have a high specific surface area (287-423 m2 g-1), well-developed porosity (0.24-0.74 cm3 g-1) and abundant oxygen-containing functional groups. Compared to the other two composites, the adsorbent derived from filter paper showed the highest adsorption capacity towards methylene blue (MB) (q max = 332.03 mg g-1) and rhodamine B (RhB) (q max = 389.59 mg g-1) with a high adsorption rate (<5 min). According to the effect of pH value on adsorption capacity, and combining the analysis of Fourier transform infrared spectrometry and X-ray photoelectron spectroscopy, the main adsorption mechanisms can be summarized as hydrogen bonds, electrostatic interactions, and π-π interaction. Besides, the occurrence of redox reactions between Fe2+/Fe0 and dye cannot be ignored. Finally, experiments on reusability were performed. They showed that the 3D net-like MMC could be easily regenerated and still maintained a removal efficiency of above 80% for RhB and 90% for MB after five cycles.

Qualitative evaluation of Forsythia suspensa by HPLC-PDA fingerprint combined with UFLC-Q-TOF-MS qualitative identification / 中国中药杂志

The analysis of Forsythia suspensa was performed on Waters Symmetry C18 column( 4. 6 mm×250 mm,5 μm) and mobile phase was methanol( A)-0. 1% formic acid aqueous solution( B) with the elution gradient. Column temperature was maintained at 30℃,and the flow rate was 1. 0 m L·min-1 with detection wavelength 265 nm. The HPLC-PDA fingerprint of F. suspensa was optimized.Chemical constituents in F. suspensa were analyzed by UFLC-Q-TOF-MS in positive and negative ion mode. The quality of 48 batches of F. suspensa from different habitats,processing methods and specifications was evaluated by similarity evaluation and cluster analysis.The 18 common peaks were confirmed. The similarity of F. suspensa from different habitats was more than 0. 98,and 56 chemical constituents were identified. Different processing methods had great influence on the quality of F. suspensa. Compared with boiled and direct drying,the quality of F. suspensa processed by sun-drying was obviously decreased. The similarity was about 0. 58. Different specifications of F. suspensa also had obvious distinction,and the similarity was about 0. 78. The effective components of grown F. suspensa,such as forsythoside A and phillyrin,were significantly reduced. The results of cluster analysis were basically consistent with the results of similarity evaluation. The establishment of fingerprint and the recognition of chemical pattern of F. suspensa can provide a more comprehensive reference for the quality control of herbs.

Application on imidazolium ionic liquid in extraction of flavonoids from natural products / 中草药

Flavonoids have many physiological and pharmacological activities. Ionic liquids are increasingly used in the extraction of flavonoids from natural products due to their unique properties. In this paper, various extraction methods of natural flavonoids were reviewed and summarized. The effects of anion and cation type, length of carbon chain, and bond cooperation on the extraction of natural flavonoids in ionic liquids, especially imidazole type ionic liquids, were also reviewed. Suggestions on selection of extractant for ionic liquid extraction of flavonoids were given. The advice of the green recovery of ionic liquids and the development of edible ionic liquids for the future direction of development were suggested. This study will lay the foundation for the basic research and industrial application of ionic liquids in the extraction of natural flavonoids.

NK cell exhaustion and NK-based checkpoint blockade immunotherapy / 中国免疫学杂志

As the first line of defense of the host immune system, natural killer cells play important roles in anti-tumor immunity, either by direct anti-tumor effects, or by assisting T cell immune responses. However, NK cells are usually functionally exhausted in tumor microenvironment, accompanied with dysregulated expression of an array of surface receptors, restricting the effector potentials of NK cells. NK-based checkpoint immunotherapy aims to trigger anti-tumor efficacy by blocking NK cell surface inhibitory receptors, unleashing NK cells from inhibitory signals of the tumor microenvironment, and reversing NK cell exhaustion, representing a novel strategy in cancer therapy. With more in-depth research to reveal the mechanisms of action, indications, and biomarkers for specific NK cell checkpoint molecules, we shall fully exploit the potentials of NK-based checkpoint blockade immunotherapy.

Hydrothermally tailor-made chitosan fiber for micro-solid phase extraction of petroleum acids in crude oils.

Tailor-made chitosan fiber was prepared via hydrothermal treatment to serve as a micro-solid phase extraction (micro-SPE) sorbent for the analysis of petroleum acids (PAs) in crude oils. Chitosan fiber, which is commercial and cheap, has a diameter of about 10 µm and a length of a few centimeters. The fibrous property of the sorbent enables the micro-SPE to deal with viscous crude oil samples because of the low back-pressure during extraction, while the abundant hydroxyl groups and amino groups on the surface of chitosan fiber can provide high density of specific sites for adsorption of PAs. Moreover, it was found that hydrothermal treatment at certain conditions could tune the surface properties of chitosan fiber, leading to significant improvement of the capacity of the fiber in adsorption of PAs. Using hydrothermally treated chitosan fiber as sorbent, the micro-SPE was applied to the determination of PAs in crude oils, with the advantages of easy-operation, rapidness and high sensitivity (the limits of detection range from 0.7 ng/g to 5.4 ng/g). Furthermore, coupled with comprehensive two dimensional gas chromatography-mass spectrometry (GC × GCMS), the treated chitosan fiber packed micro-SPE method showed a great potential for comprehensive profiling of PAs in crude oils.

Porphyrin-based magnetic nanocomposites for efficient extraction of polycyclic aromatic hydrocarbons from water samples.

Stable and reusable porphyrin-based magnetic nanocomposites were successfully synthesized for efficient extraction of polycyclic aromatic hydrocarbons (PAHs) from environmental water samples. Meso-Tetra (4-carboxyphenyl) porphyrin (TCPP), a kind of porphyrin, can connect the copolymer after amidation and was linked to Fe3O4@SiO2 magnetic nanospheres via cross-coupling. Several characteristic techniques such as field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectrometry, vibrating sample magnetometry and a tensiometer were used to characterize the as-synthesized materials. The structure of the copolymer was similar to that of graphene, possessing sp2-conjugated carbon rings, but with an appropriate amount of delocalized π-electrons giving rise to the higher extraction efficiency for heavy PAHs without sacrificing the performance in the extraction of light PAHs. Six extraction parameters, including the TCPP:Fe3O4@SiO2 (m:m) ratio, the amount of adsorbents, the type of desorption solvent, the desorption solvent volume, the adsorption time and the desorption time, were investigated. After the optimization of extraction conditions, a comparison of the extraction efficiency of Fe3O4@SiO2-TCPP and Fe3O4@SiO2@GO was carried out. The adsorption mechanism of TCPP to PAHs was studied by first-principles density functional theory (DFT) calculations. Combining experimental and calculated results, it was shown that the π-π stacking interaction was the main adsorption mechanism of TCPP for PAHs and that the amount of delocalized π-electrons plays an important role in the elution process. Under the optimal conditions, Fe3O4@SiO2-porphyrin showed good precision in intra-day (<8.9%) and inter-day (<13.0%) detection, low method detection limits (2-10 ng L-1), and wide linearity (10-10000 ng L-1). The method was applied to simultaneous analysis of 15 PAHs with acceptable recoveries, which were 71.1%-106.0% for ground water samples and 73.7%-107.1% for Yangtze River water samples, respectively.

Magnetic extractant with an Fe3O4@SiO2 core and aqueous ammonia coating for microextraction of petroleum acids.

Magnetic aqueous ammonia (MAA) was prepared as a magnetic extractant for dispersive microextraction of petroleum acids (PAs). The amount of extractant in MAA was custom-made by a simple approach. In the MAA composed of an aqueous ammonia coating and Fe3O4@SiO2 core, the coating is a base extractant that can selectively extract acids, while the magnetic core serves as a support to achieve dispersion as well as rapid magnetic retrieval of the extractant during the extraction processes. This is the first use of reusable, stable and modifiable Fe3O4@SiO2 as a support instead of bare Fe3O4 in a magnetic particle assisted dispersive liquid-liquid microextraction technique. The parameters that affect extraction efficiency were investigated. The sampling step as well as the desorption step can be completed in 2 min. The linear ranges are 5-5000 ng g-1, while the limits of quantification range from 2.5 to 6.2 ng g-1. The recoveries in spiked crude oil samples are in the range of 79.1% to 112.1% with relative standard deviations less than 11.3% (intra-day) and 13.4% (inter-day). Finally, the proposed method was applied to the analysis of PAs in diluted crude oils with different maturities. In comparison to the existing methods for extraction of PAs, the proposed method provides superior performances including high throughput (12-well plate), high degree of sample clean-up, and low consumption of separation material, solvent and time.

Cucurbitane-type triterpenoids from the tubers of Hemsleya dolichocarpa / 药学学报

Seven cucurbitane-type triterpenoids were isolated from the ethanol extract of the tubers of Hemsleya dolichocarpa, with a combination of various chromatographic approaches, including silica gel, Sephadex LH-20, Semi-HPLC and so on. On the basis of spectroscopic data analysis, they were identified as 3β,11α,26,27-tetrahydroxycucurbita-5,24(E)-diene-3,26-glucosides (1), scandenogenin D (2), jinfushanencin F (3), scandenoside R3 (4), scandenoside R1 (5), scandenogenin A (6), scandenoside R2 (7). Among them, compound 1 is a new triterpenoid, compound 2 showed remarkable activity against human cancer cell line HeLa with IC50 value of 6.78 μmol·L-1.

Pb2+-Induced Allosteric PS2.M as A Label-Free Colorimetric Sensor for Detection of Cumulative Radon Radiation / 分析化学

A new sensitive method for detection of cumulative radon radiation based on the lead was established. PS2.M which stabilized by K+with hemin as a co-factor exhibits superior peroxidase-like activity, and can effectively catalyze the H2O2-mediated oxidation of TMB. In the presence of Pb2+, K+-stabilized PS2.M DNAzymes are induced to undergo a conformational change,because Pb2+has a higher efficiency with regard to stabilizing G-quadruplexes than K+, accompanied by a decrease of catalytic activity and a sharp decrease of readout signal. In the work, a novel"turn-off"model of colorimetry-Pb2+biosensor based on superior peroxidase-like activity of G-quadruplex for Pb2+analysis was developed. The fading degree of reaction system (△A value) was linearly related to Pb2+concentration in the range of 5. 0×10-9-1. 8× 10-7mol/L. The linear regression equation was △A=0.36+0.13C (10-8mol/L), with R=0.9987. The detection limits of lead and radon were 3.76 nmol/L(S/N=3) and 1.96×103Bq·h/m3(S/N=3), respectively. The method exhibited good selectivity, high sensitivity and convenient operation, and could avoid the radioactive hazard in determination of the radon in environment.