Selective Cleavage of α-Olefins to Produce Acetylene and Hydrogen.

Acetylene production from mixed α-olefins emerges as a potentially green and energy-efficient approach with significant scientific value in the selective cleavage of C-C bonds. On the Pd(100) surface, it is experimentally revealed that C2 to C4 α-olefins undergo selective thermal cleavage to form surface acetylene and hydrogen. The high selectivity toward acetylene is attributed to the 4-fold hollow sites which are adept at severing the terminal double bonds in α-olefins to produce acetylene. A challenge arises, however, because acetylene tends to stay at the Pd(100) surface. By using the surface alloying methodology with alien Au, the surface Pd d-band center has been successfully shifted away from the Fermi level to release surface-generated acetylene from α-olefins as a gaseous product. Our study actually provides a technological strategy to economically produce acetylene and hydrogen from α-olefins.

[Determination of tetrodotoxin in urine by liquid chromatography-tandem mass spectrometry with internal standard calibration].

OBJECTIVE: An analytical method was developed for tetrodotoxin(TTX) in urine by liquid chromatography-tandem mass spectrometry(LC-MS/MS) with internal standard calibration. METHODS: TTX in the sample was extracted with the mixture of acetic acid/methanol/acetonitrile(0.005 mL/0.8 mL/1.8 mL), cleaned by solid phase extraction(SPE) with cation exchange cartridge, eluted with 50% acetonitrile/water containing 0.3% hydrochloric acid, and neutralized with ammonia. The extract was separated by a Waters XBridge~(TM) BEH Amide column(150 mm×3.0mm, 1.7 µm) and measured by MS/MS. By optimizing sample extraction and SPE cleanup conditions, the problems of low recovery and strong suppression effects of MS signal for TTX in urine were resolved when cleaned with cation exchange cartridge. RESULTS: Quantitatively calibrated by the internal standard of Kasugamycin, good linear relationship was found for TTX in urine at the range of 0.2-200 µg/L with the correlation coefficient(r~2) of 0.997. The limits of detection and quantitation for TTX in sample matrix were 0.1 and 0.2µg/L, respectively. The average recoveries at three spiking levels(0.2, 10.0 and 200 µg/L) were 89.3%-95.3% with relative standard deviation(n=6) less than 5.1%. The concentrations of TTX in urine from 11 poisoning patients were 0.4-138 µg/L. The detection rate was 100% in urine collected within 3 days after poisoning. CONCLUSION: The established method was simple, accurate and sensitive. It can provide reliable technical support for the rapid treatment of TTX poisoning events and the study of toxin metabolism in vivo.

Simultaneous Analysis of Nicarbazin, Diclazuril, Toltrazuril, and Its Two Metabolites in Chicken Muscle and Eggs by In-Syringe Dispersive Solid-Phase Filter Clean-Up Followed by Liquid Chromatography-Tandem Mass Spectrometry.

Nicarbazin (NICA) and triazine anticoccidial drugs (diclazuril (DIZ) and toltrazuril (TOZ)) are the primary strategy for preventing and treating coccidiosis. To prevent the development of drug resistance and mitigate the potential chronic toxicity to humans resulting from prolonged exposure, a liquid chromatography-tandem mass spectrometry method with high reliability and sensitivity was developed to determine NICA, DIZ, TOZ, and its two metabolites in chicken muscle and eggs. Upon establishing the extraction conditions involving 10 mL of acetonitrile and 10 min of sonication, in-syringe dispersive solid-phase extraction with silica was performed in combination with n-hexane clean-up. The selection of isotope peaks of precursor ions and low-mass range scanning allowed the two transitions for the quantification of all compounds. The limits of detection for DIZ and NICA were both 0.1 µg/kg, and for TOZ and metabolites, they were 0.3 µg/kg; the limits of quantitation were 0.3 and 1 µg/kg, respectively. The linear range was 0.25-50 ng/mL with a correlation coefficient r > 0.999. The average recoveries at three spiking levels in muscle and eggs were 90.1-105.2% and 94.0-103.7% with the relative standard deviations of 3.0-8.1% and 3.1-14.4%, respectively. The precision, accuracy, and stability were evaluated by three quality control samples.

CircRUNX1 drives the malignant phenotypes of lung adenocarcinoma through mediating the miR-5195-3p/HMGB3 network.

BACKGROUND: Circular RNAs (circRNAs) are key factors in the regulation of cancer progression. However, the role of circRUNX1 in lung adenocarcinoma (LUAD) progression is unclear. METHODS: The expression levels of circRUNX1, microRNA (miR)-5195-3p, and high-mobility group protein B3 (HMGB3) were detected by quantitative real-time PCR. Cell proliferation, migration, invasion and apoptosis were analyzed by EdU staining, colony formation assay, transwell assay and flow cytometry. Protein levels were measured using western blot analysis. The interaction between miR-5195-3p and circRUNX1 or HMGB3 was verified by dual-luciferase reporter assay and RIP assay. Animal experiments were performed to investigate the role of circRUNX1 in LUAD tumorigenesis. RESULTS: We found that circRUNX1 was upregulated in LUAD tumor tissues and cells. CircRUNX1 knockdown suppressed LUAD cell proliferation and metastasis, while promoted apoptosis. In terms of mechanism, we found that circRUNX1 could sponge miR-5195-3p, and miR-5195-3p inhibitor abolished the regulation of circRUNX1 knockdown on LUAD cell proliferation, metastasis and apoptosis. In addition, miR-5195-3p could target HMGB3, and HMGB3 overexpression reversed the inhibition effect of miR-5195-3p on LUAD progression. Moreover, circRUNX1 knockdown reduced LUAD tumorigenesis. CONCLUSION: CircRUNX1 facilitated LUAD proliferation and metastasis by regulating the miR-5195-3p/HMGB3 axis, suggesting that it might be a possible therapeutic target for LUAD.

Burnout syndrome, doctor-patient relationship and family support of pediatric medical staff during a COVID-19 Local outbreak in Shanghai China: A cross-sectional survey study.

Objectives: To explore burnout syndrome (BOS) incidence, doctor-patient relationship, and family support on pediatric medical staff in Shanghai comprehensive hospitals during a COVID-19 local outbreak. Methods: A cross-sectional survey of pediatric medical staff from 7 comprehensive hospitals across Shanghai was conducted from March to July 2022. The survey included BOS, doctor-patient relationships, family support, and the related factors of COVID-19. The T-test, variance, the LSD-t test, Pearson's r correlation coefficient, and multiple regression analyses examined the data. Results: Using Maslach Burnout Inventory-General Survey (MBI-GS), 81.67% of pediatric medical staff had moderate BOS, and 13.75% were severe. The difficult doctor-patient relationship was positively correlated with emotional exhaustion(EE), cynicism(Cy), and negatively with personal accomplishment(PA). When medical staff need help, the greater the support provided by the family, the lower the EE and CY, and the higher the PA. Conclusion: "In our study, the pediatric medical staff in Shanghai comprehensive hospitals had significant BOS during a COVID-19 local outbreak." We provided the potential steps that can be taken to reduce the increasing rate of BOS in pandemics. These measures include increased job satisfaction, psychological support, maintaining good health, increased salary, lower intent to leave the profession, regularly carrying out COVID-19 prevention training, improving doctor-patient relations, and strengthening family support.

Determination of tetrodotoxin in salted pufferfish by liquid chromatography-tandem mass spectrometry / 预防医学

Objective@#To develop a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method with cation exchange-based solid phase extraction (SPE) for determination of tetrodotoxin (TTX) in salted pufferfish. @*Methods@#Evenly crushed salted pufferfish samples were subjected to ultrasound-assisted extraction with 0.5% acetic acid/50% methanol/water. The extract was cleaned with cation exchange-based SPE cartridge and eluted with 0.3% hydrochloric acid and 50% acetonitrile/water. The eluent was neutralized with ammonia and separated with a Waters XBridgeTM BEH Amide column (150 mm×3.0 mm, 1.7 μm), and determined using LC-MS/MS in a multiple reaction monitoring mode.@*Results@#The matrix effects of TTX were 85.7%-92.4%, and the matrix suppression effect was under effective control following clean-up procedures using the optimized SPE method. The TTX showed a good linear relationship at the range of 2.0 to 4 000 μg/kg, with a correlation coefficient (r2) of 0.999 2. The limits of detection and quantitation for TTX in sample matrix were 1.0 μg/kg and 2.0 μg/kg, respectively. The mean spiked-recovery rates were 81.2% to 96.5% at spiked amounts of 2.0, 200 μg/kg and 2 200 μg/kg, with relative standard deviations (RSDs) of 4.3% to 7.5%. The intraday accuracy and precision of TTX were 84.4% to 95.6% and 4.9% to 5.8% in quality control samples, and the interday accuracy and precision of TTX were 86.1% to 94.9% and 5.5% to 8.5% in quality control samples. The detection of TTX was 60.5% in 38 market-sold salted pufferfish products using the established LC-MS/MS method.@*Conclusion@#The established LC-MS/MS method is effective for accurate quantitative determination of TTX in salted pufferfish.

Rapid hemostasis and high bioactivity cerium-containing mesoporous bioglass for hemostatic materials.

A two-step-acid-catalyzed-self-assembly method was used to prepare cerium-containing mesoporous bioactive glass with P123 as a template. The results showed that MBG without cerium and MBG with cerium slightly affected its surface area, and its water absorption rate was significantly higher. In vitro coagulation experiments showed that Ce-MBG significantly reduces prothrombin time (PT) and activated partial thromboplastin time (APTT), indicating that MBG containing Ce could promote coagulation and platelet adhesion compared with MBG. These suggested that Ce-MBG may be a good dressing with hemostatic properties, which could shorten the bleeding time of the wound and control the bleeding.

A perspective on oxide-supported single-atom catalysts.

Single-atom catalysts (SACs) can not only maximize the metal atom utilization efficiency, but also show drastically improved catalytic performance for various important catalytic processes. Insights into the working principles of SACs provide rational guidance to design and prepare advanced catalysts. Many factors have been claimed to affect the performance of SACs, which makes it very challenging to clarify the correlation between the catalytic performance and physicochemical characteristics of SACs. Oxide-supported SACs are one of the most extensively explored systems. In this minireview, some latest developments on the determining factors of the stability, activity and selectivity of SACs on oxide supports are overviewed. Discussed also are the reaction mechanisms for different systems and methods that are employed to correlate the properties with the catalyst structures at the atomic level. In particular, a recently proposed surface free energy approach is introduced to fabricate well-defined modelled SACs that may help address some key issues in the development of SACs in the future.

Occurrence and ecological risk of pharmaceuticals and personal care products (PPCPs) and pesticides in typical surface watersheds, China.

To evaluate the occurrence and ecological risk of organic contaminants in aquatic environment in China, a method for simultaneously detecting 130 pharmaceuticals and personal care products (PPCPs) and 35 pesticides has been established using solid phase extraction-ultra performance liquid chromatography-tandem mass spectrometry (SPE-UPLC-MS/MS) method. In the present survey, a total of 122 target compounds (103 PPCPs and 19 pesticides) were detected in seven major watersheds in China, with average concentrations ranged from 0.02 ng/L (sulfamerazine) to 332.75 ng/L (bisphenol A), revealing that PPCPs and pesticides were widely distributed in surface water of China. Antibiotics and organophosphorus were the most ubiquitously PPCPs and pesticides, respectively; quinolones were the predominant antibiotics, most of which were detected in more than 96% sampling sites, with average concentrations ranged from 2.14 to 309.67 ng/L; six pesticides including isoprocarb, fenobucarb, acetamiprid, imidacloprid, acetochlor and bentazone were detected in more than 80% sampling sites, with average concentrations ranged from 5.62 to 225.93 ng/L; more than half of the non-antibiotic pharmaceuticals were hormones; and diethyltoluamide (DEET) was predominant personal care products; The risk assessment showed that each watershed was at potential medium ecological risk based on their mean concentration (RQTotal > 1), and pesticides were the main compounds arising risks.

[Occurrence and Spatial Distribution of Volatile Organic Compounds in Urban Drinking Water Distribution Systems].

Volatile organic compounds (VOCs) in the urban drinking water distribution systems for two coastal cities (S City and L City) in China were analyzed. Health risk assessments of VOCs detected in tap water were performed, and the distribution characteristics of VOCs in the tap water pipe network were also investigated. Among 47 target VOCs, 16 compounds were detected, of which 11 were detected in both S City and L City. Halogenated hydrocarbons were the most commonly detected VOCs, with trihalomethanes (including bromodichloromethane, dibromochloromethane, and bromoform) having the highest detection frequencies (92%-100%). With the exception of bromodichloromethane and dibromochloromethane, the maximum concentrations of detected VOCs in both cities complied with the relevant limits regulated by the standards for drinking water quality (GB 5749-2006). For bromodichloromethane and dibromochloromethane, not only did their concentrations exceed the standard limits of GB 5749-2006 (60 µg·L-1 for bromodichloromethane and 100 µg·L-1 for dibromochloromethane), but their lifetime cancer risks (LCR) were estimated at unacceptable levels (>10-4). Therefore, these two compounds should be given sufficient attention or be classified as priority control pollutants in municipal water supply networks. In addition, the spatial distribution of eight VOCs with high detection frequencies (>90%) in the tap water pipe network of S City was investigated. The concentrations of VOCs (excluding toluene) in this urban drinking water distribution system gradually decreased with increasing distance from the drinking water treatment plant.

Spatial variations in the occurrence of potentially genotoxic disinfection by-products in drinking water distribution systems in China.

We investigated the occurrence of disinfection by-products (DBPs) with genotoxic potential in plant effluent and distribution water samples from four drinking water treatment plants in two Chinese cities using comprehensive two-dimensional gas chromatography-quadrupole mass spectrometry. We tested the samples for 37 DBPs with genotoxic potential, which we had previously identified and prioritized in water under controlled laboratory conditions. Thirty of these DBPs were found in the water samples at detection frequencies of between 10% and 100%, and at concentrations between 3.90 and 1.77 × 103 ng/L. Of the DBPs detected, the concentrations of 1,1,1-trichloropropan-2-one were highest, and ranged from 299 to 1.77 × 103 ng/L with an average of 796 ng/L. The concentrations of 6-chloro-2-N-propan-2-yl-1,3,5-triazine-2,4-diamine and 2,6-ditert-butylcyclohexa-2,5-diene-1,4-dione were also much higher, and ranged from 107 to 721 ng/L, and from 152 to 504 ng/L, respectively. Concentrations of 1,1,1-trichloropropan-2-one, 2-chloro-1-phenylethanone, 2,2-dichloro-1-phenylethanone and 6-chloro-2-N-propan-2-yl-1,3,5-triazine-2,4-diamine were highest at or near the treatment plants and decreased with increasing distance from the plants. Patterns in the concentrations of benzaldehyde, 2-phenylpropan-2-ol, and 1-methylnaphthalene differed between plants. The levels of DBPs such as 4-ethylbenzaldehyde, (E)-non-2-enal, and 1-phenylethanone were relatively constant within the distribution systems, even at the furthest sampling points (20 km < d < 30 km). A risk assessment showed that there was no risk to human health. It is, however, important to note that, because of limited availability of toxicity data, only five DBPs were evaluated in this study. The risks to health associated with exposure to the target potentially genotoxic DBPs should not be ignored because of their prolonged existence in drinking water.

Tracking changes in composition and amount of dissolved organic matter throughout drinking water treatment plants by comprehensive two-dimensional gas chromatography-quadrupole mass spectrometry.

Dissolved organic matter (DOM) can affect the performance of water treatment processes and produce undesirable disinfection by-products during disinfection. Several studies have been undertaken on the structural characterization of DOM, but its fate during drinking water treatment processes is still not fully understood. In this work, the nontargeted screening method of comprehensive two-dimensional gas chromatography-quadrupole mass spectrometry (GC×GC-qMS) was used to reveal the detailed changes of different chemical classes of compounds in DOM during conventional and advanced drinking water treatment processes at three drinking water treatment plants in China. The results showed that when the dissolved organic carbon removal was low, shifts in the DOM composition could not be detected with the specific ultraviolet absorbance at 254nm, but the changes were clear in the three-dimensional fluorescence excitation-emission matrix or GC×GC-qMS analyses. Coagulation-sedimentation processes selectively removed 37-59% of the nitrogenous compounds, alcohols and aromatic hydrocarbons but increased the concentrations of halogen-containing compounds by 17-26% because of the contact time with chlorine in this step. Filtration was less efficient at removing DOM but preferentially removed 21-60% of the acids. However, other organic matter would be released from the filter (e.g., nitrogenous compounds, acids, and aromatic hydrocarbons). Biological activated carbon (BAC) treatment removed most of the compounds produced from ozonation, particularly ketones, alcohols, halogen-containing compounds and acids. However, it should be noted that certain highly polar or high molecular weight compounds not identified in this study might be released from the BAC bed. After the whole treatment processes, the concentrations of nitrogenous compounds, alcohols, alkenes, aromatic hydrocarbons and ketones were decreased more by the advanced treatment processes than by the conventional treatment processes. Alcohol and ketone removals were probably related to the reduction in protein-like materials. Alkane removal was probably related to the reduction in fulvic acid-like and humic acid-like materials.

WITHDRAWN:Radix astragali induces in vitro and in vivo synthesis of fetal hemoglobin in non­transfusion­dependent ß­thalassemia: A preliminary study.

Ahead of Print article withdrawn by publisher.

Modeling the transport of TiO2 nanoparticle aggregates in saturated and unsaturated granular media: effects of ionic strength and pH.

This study aims to explore the mechanisms governing the transport and retention kinetics of TiO(2) nanoparticle aggregates (NPAs) in flow-through columns of packed sand, particularly under unsaturated conditions. The study was carried out at different pHs (2.6, 7.1, and 9.6) and ionic strengths (ISs) (1.0, 10, and 50 mM). A two-site kinetic attachment model was used to describe transport behaviors of TiO(2) NPAs. At low ISs (i.e., 1.0 and 10 mM) and in neutral/alkaline conditions, high mobility of TiO(2) NPAs was observed in both saturated and unsaturated conditions. However, the retention of TiO(2) NPAs was substantially enhanced at the high IS (50 mM) and in extremely acidity condition (pH = 2.6), because of increased aggregation and straining of TiO(2) NPAs during their transport course. The breakthrough curves (BTCs) of TiO(2) NPAs under unsaturated and saturated conditions almost overlapped, suggesting that decreasing the water saturation did not enhance the retention of TiO(2) NPAs in sand columns. This was probably due to the repulsive interactions existed between negatively charged air-water and TiO(2) NPAs systems that resulted in unfavorable attachment conditions. The two-site kinetic attachment model provided a good description for the BTCs of TiO(2) NPAs both in saturated and unsaturated conditions. The fitted parameters could successfully explain the transport behaviors of TiO(2) NPAs under various solution chemistries.

[Effect of low-dose hydroxyurea with sodium butyrate on globin gene expression in human erythroid progenitor cells].

OBJECTIVE: To investigate the effects of combined use of low-dose hydroxyurea (HU) and sodium butyrate (NaB) on the expression of 7 globin genes (zeta, alpha, epsilon, Ggamma, Agamma, delta, and beta) in human erythroid progenitor cells. METHODS: Human erythroid progenitor cells were cultured using a two-step liquid culture system and treated with HU and NaB either alone or in combination. The inhibitory effects of the agents on the cell growth were monitored with trypan blue exclusion assay, and the changes in the mRNA of the 7 globin genes were detected using RT-PCR. RESULTS: Low-dose HU combined with NaB resulted in significantly lower inhibition rate of the erythroid progenitor cells than routine dose HU and NaB used alone (28.56% and 38.80%, respectively, P<0.05). Compared with untreated cells (0.653-/+0.092 and 0.515-/+0.048), HU combined with NaB significantly increased the expression of Ggamma-and Agamma- mRNA (1.203-/+0.018 and 0.915-/+0.088, respectively, P<0.05), and HU and NaB used alone produced similar effects (1.305-/+0.016 and 0.956-/+0.029 for HU, and 1.193-/+0.070 and 0.883-/+0.012 for NaB, P>0.05). HU and NaB, either used alone or in combination or at different doses, caused no significant changes in the other globin genes (zeta, alpha, epsilon, delta and beta) (P>0.05). CONCLUSION: Low-dose HU combined with NaB can up-regulate gamma globin gene expression, especially Ggamma-mRNA expression, to decrease the growth inhibition on human erythroid progenitor cells in vitro, but produces no significant effect on the expressions of zeta, alpha, epsilon, delta and beta genes.

[Mapping QTLs related to head length, eye diameter and eye cross of common carp (Cyprinus carpio L.)].

A common carp gynogenetic line including 44 individuals derived from the cross Barbless carp x Hebao-cold tolerance red carp was used to construct a linkage map using 445 markers (265 AFLP markers, 127 SSR markers, 37 EST-SSR markers and 16 RAPD markers). Quantitative traits loci (QTLs) associated with head length, eye diameter, and eye cross were identified by composite interval mapping of the software WinQTLCart2.5. Five QTLs were identified for head length on the linkage group of LG2, LG3, LG40, and LG4, which explained 12.39% to 34.29% of the total variation of the head length. All of their additive effects were negative. Two QTLs were associated with eye diameter on the linkage groups of LG39 (qED-39-1) and LG40 (qED-40-1), which explained 9.77% and 5.62% of the total variation of the eye diameter, respectively. The additive effect of qED-39-1 was positive and that of qED-40-1 was negative. Two QTLs were responsible for eye cross on the linkage group of LG28 and LG20, explaining 8.88% and 8.29% of the total variation of the eye cross, respectively. The additive effect of qEC-28-1 was negative and that of qEC-20-1 was positive.