Screening anabolic androgenic steroids in human urine: an application of the state-of-the-art gas chromatography-Orbitrap high-resolution mass spectrometry.

Over the past few decades, anabolic androgenic steroids (AASs) have been abused in and out of competition for their performance-enhancing and muscle-building properties. Traditionally, AASs were commonly detected using gas chromatography-mass spectrometry in the initial testing procedure for doping control purposes. Gas chromatography-Orbitrap high-resolution mass spectrometry (GC-Orbitrap-HRMS) is a new technology that has many advantages in comparison with GC-MS (e.g., a maximum resolving power of 240,000 (FWHM at m/z 200), excellent sub-ppm mass accuracy, and retrospective data analysis after data acquisition). Anti-doping practitioners are encouraged to take full advantage of the updated techniques of chromatography-mass spectrometry to develop sensitive, specific, and rapid screening methods for AASs. A new method for screening a wide range of AASs in human urine using GC-Orbitrap-HRMS was developed and validated. The method can qualitatively determine 70 anabolic androgenic steroids according to the minimum required performance limit of the World Anti-Doping Agency. Moreover, the validated method was successfully applied to detect six metabolites in urine after the oral administration of metandienone, and their excretion curves in vivo were studied. Metandienone M6 (17ß-hydroxymethyl-17α-methyl-18-nor-androst-1,4,13-trien-3-one) has been identified as a long-term urinary metabolite which can be detected up to 7 weeks, thus providing a longer detection window compared with previous studies. This study provides a rationale for GC-Orbitrap-HRMS in drug metabolism and non-targeted screening.

Derivatization-Enhanced Analysis of Glucocorticoids for Structural Characterization by Gas Chromatography-Orbitrap High-Resolution Mass Spectrometry.

Glucocorticoids are classified in section S9 of the Prohibited List of the World Anti-Doping Agency, due to a potential risk to improving physical performance and causing harm to the health of athletes. Based on the similar physiological actions of glucocorticoids, both differentiating known glucocorticoids and identifying unknown glucocorticoids are important for doping control. Gas chromatography coupled with mass spectrometry plays an important role in structural characterization because of abundant structural diagnostic ions produced by electron ionization. It also provides a chance to study the fragmentation patterns. Thus, an enhanced derivatization procedure was optimized to produce trimethylsilylated glucocorticoids and structural diagnostic ions of nineteen trimethylsilylated glucocorticoids were obtained by gas chromatography-orbitrap high-resolution mass spectrometry. In our study, glucocorticoids were classified as: 3-keto-4-ene, 1,4-diene-3-keto, 3α-hydroxy with saturated A-ring, 21-hydroxy-20-keto and halo substituent glucocorticoids based on their structural difference. Structural diagnostic ions that contributed to structural characterization were specifically presented and the fragment patterns were demonstrated according to the above categories. This study not only gave new insights into the structural characterization of these glucocorticoids but also provided evidence for tracing unknown glucocorticoids or chemically modified molecules.

Stable Isotope Labeling-Based Nontargeted Strategy for Characterization of the In Vitro Metabolic Profile of a Novel Doping BPC-157 in Doping Control by UHPLC-HRMS.

Traditional strategies for the metabolic profiling of doping are limited by the unpredictable metabolic pathways and the numerous proportions of background and chemical noise that lead to inadequate metabolism knowledge, thereby affecting the selection of optimal detection targets. Thus, a stable isotope labeling-based nontargeted strategy combined with ultra-high-performance liquid chromatography-high-resolution mass spectrometry (UHPLC-HRMS) was first proposed for the effective and rapid metabolism analysis of small-molecule doping agents and demonstrated via its application to a novel doping BPC-157. Using 13C/15N-labeled BPC-157, a complete workflow including automatic 13C0,15N0-13C6,15N2m/z pair picking based on the characteristic behaviors of isotope pairs was constructed, and one metabolite produced by a novel metabolic pathway plus eight metabolites produced by the conventional amide-bond breaking metabolic pathway were successfully discovered from two incubation models. Furthermore, a specific method for the detection of BPC-157 and the five main metabolites in human urine was developed and validated with satisfactory detection limits (0.01~0.11 ng/mL) and excellent quantitative ability (linearity: 0.02~50 ng/mL with R2 > 0.999; relative error (RE)% < 10% and relative standard deviation (RSD)% < 5%; recovery > 90%). The novel metabolic pathway and the in vitro metabolic profile could provide new insights into the biotransformation of BPC-157 and improved targets for doping control.

Risk assessment and early warning of the presence of heavy metal pollution in strawberries.

Heavy metal pollution is a major threat to agricultural produce and it can pose potential ecological risks which subsequently impacts on human health. Strawberries are an economically important produce of China. The intrinsic link of heavy metal pollution risk in the soil-strawberry ecosystem is of concern. In this study, the pollution index of heavy metal pollutants in farmlands of different provinces were evaluated, and the results showed significantly high levels of cadmium. In addition, Nemerow integrated pollution index analysis showed that low-pollution farmlands only accounted for 14.07% of the total arable land area. Then, the transfer factors were used to calculate the migration of heavy metals from the soil into strawberries. The results showed that cadmium and nickel were relatively high in strawberries from the Guangxi province. Similar results were found for mercury in Jiangxi Province. The pollution index of single food pollution also showed that mercury in strawberries from Jiangxi Province was at a moderate pollution level. The comprehensive pollution index indicated that heavy metal pollution in strawberries in Central China may be severe. In addition, spatial clustering analysis showed that cadmium, chromium, lead, arsenic and zinc in strawberries had significant hotspot clustering in central, south and southwest China. Finally, our studies also suggested that the risk of carcinogenic and non-carcinogenic diseases was higher in the (2, 4] years age group than in other age groups. People in Yunnan Province were also found to have a higher non-carcinogenic risk than those in other provinces and cities in China. This study provides a comprehensive view of the potential risks of heavy metal contamination in strawberries, which could provide assistance in the design of regulatory and risk management programs for chemical pollutants in strawberries, thus ensuring the safety of consumption of these edible fruits.

An Improved POD Model for Fast Semi-Quantitative Analysis of Carbendazim in Fruit by Surface Enhanced Raman Spectroscopy.

The current detection method of carbendazim suffers from the disadvantages of complicated preprocessing and long cycle time. In order to solve the problem of rapid quantitative screening of finite contaminants, this article proposed a qualitative method based on characteristic peaks and a semi-quantitative method based on threshold to detect carbendazim in apple, and finally the method is evaluated by a validation system based on binary output. The results showed that the detection limit for carbendazim was 0.5 mg/kg, and the detection probability was 100% when the concentration was no less than 1 mg/kg. The semi-quantitative analysis method had a false positive rate of 0% and 5% at 0.5 mg/kg and 2.5 mg/kg, respectively. The results of method evaluation showed that when the added concentration was greater than 2.5 mg/kg, the qualitative detection method was consistent with the reference method. When the concentration was no less than 5 mg/kg, the semi-quantitative method is consistent between different labs. The semi-quantitative method proposed in this study can achieve the screening of finite contaminants in blind samples and simplify the test validation process through the detection probability model, which can meet the needs of rapid on-site detection and has a good application prospect.

Online trypsin digestion coupled with LC-MS/MS for detecting of A1 and A2 types of ß-casein proteins in pasteurized milk using biomarker peptides.

Bovine A1-or A2-type ß-caseins have attracted a growing interest due to their variation in beta-casomorphin-7 (BCM-7) formation, which may affect health. In the present work, identification and quantification of A1 and A2 types of ß-casein proteins at the peptide level was achieved for the first time. An automated and online immobilized trypsin digestion system was employed for high throughput digesting of proteins into peptides. Tryptic peptides were separated and analyzed subsequently by liquid chromatography coupled to mass spectrometry platform. Two specific peptides ranging from the position of 49 to 97 in the peptide chain were selected for the identification and quantification of A1 and A2 ß-casein, which covered the different amino acids between them. Synthetic isotopically labeled winged peptides were used for absolute quantification. Compared with traditional in-solution digestion, online digestion shortens digestion times from 2 to 24 h to 4 min. The limits of quantification (LOQ) of A1 and A2 ß-casein in pasteurized milk are 0.8 and 2.4 µg/g, respectively. To further demonstrate the applicability of the proposed method, commercial pasteurized milk tests were performed with satisfactory results. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-022-05376-6.

Aminolactonization of Unactivated Alkenes Catalyzed by Aryl Iodine.

A one-step protocol of the aryl iodine-catalyzed aminolactonization of unactivated alkenes under oxidation conditions was first reported to efficiently construct diverse amino lactones in a short time using HNTs2 as the compatible nitrogen source. In addition, we investigated the influence of the reaction rate based on the structure of the iodoarene precatalyst, which revealed the selective adjustment effect on aminolactonization and oxylactonization. Finally, preliminary experiments verified the feasibility of asymmetric aminolactonization catalyzed by a chiral iodoarene precatalyst.

Iodoarene-Catalyzed Oxyamination of Unactivated Alkenes to Synthesize 5-Imino-2-Tetrahydrofuranyl Methanamine Derivatives.

Reported here is the room-temperature metal-free iodoarene-catalyzed oxyamination of unactivated alkenes. In this process, the alkenes are difunctionalized by the oxygen atom of the amide group and the nitrogen in an exogenous HNTs2 molecule. This mild and open-air reaction provided an efficient synthesis to N-bistosyl-substituted 5-imino-2-tetrahydrofuranyl methanamine derivatives, which are important motifs in drug development and biological studies. Mechanistic study based on experiments and density functional theory calculations showed that this transformation proceeds via activation of the substrate alkene by an in situ generated cationic iodonium(III) intermediate, which is subsequently attacked by an oxygen atom (instead of nitrogen) of amides to form a five-membered ring intermediate. Finally, this intermediate undergoes an SN2 reaction by NTs2 as the nucleophile to give the oxygen and nitrogen difunctionalized 5-imino-2-tetrahydrofuranyl methanamine product. An asymmetric variant of the present alkene oxyamination using chiral iodoarenes as catalysts also gave promising results for some of the substrates.

Effects of miR-599 targeting YAP1 on proliferation, invasion and apoptosis of bladder urothelial carcinoma cells.

The aim of this study was to investigate the effects of microRNA (miR)-599 targeting Yes-associated protein 1 (YAP1) on the proliferation, invasion and apoptosis of bladder urothelial carcinoma cell line J82. J82 cells cultured in vitro were divided into miR-nc group (transfected with analog negative control miR-NC), miR-599 group (transfected with miR-599 analog), miR-599 + pcDNA3.1 group (co transfected with miR-599 analog and pcDNA3.1 empty vector), miR-599 + pcDNA3.1-YAP1 group (co transfected with miR-599 analog and pcDNA3.1-YAP1 over expression vector), the targeting relationship between miR-599 and YAP1 was detected by double luciferase reporter gene assay, the expression level of miR-599 was detected by real-time fluorescence quantitative PCR, the expression of YAP1 was detected by Western blot, cell proliferation was detected by MTT method, cell invasion was detected by Transwell's cell experiment, and apoptosis was detected by flow cytometry. The miR-599 was able to bind to YAP1 targetingly; compared with those in miR-NC group, miR-599 expression level and apoptosis rate in miR-599 group were significantly higher, however, the expression level of YAP1 protein and the abilities of cell proliferation and invasion were significantly lower (P < 0.05); there was no significant difference in the above indexes between miR-599 group and miR-599 + pcDNA3.1 group (P > 0.05); compared with those in miR-599 + pcDNA3.1 group, the expression level of YAP1 protein and the abilities of cell proliferation and invasion in miR-599 + pcDNA3.1-YAP1 group were significantly higher, while the apoptotic rate was significantly lower (P < 0.05). MiR-599 may inhibit the proliferation, invasion and promote apoptosis of bladder urothelial carcinoma J82 cells by targetingly regulating YAP1.

The effect and mechanism of neighbourhood choice on socioeconomic integration of migrants: Evidence from China.

On the basis of the 2013 China Migrants Dynamic Survey provided by the National Health and Family Planning Commission, we explored the impact of neighbourhood choice on the socioeconomic integration of migrants and the underlying mechanism. When problems with endogeneity were controlled, the findings showed that neighbourhood choice had a significant positive effect on the socioeconomic integration of migrants, that is, compared with migrants living in informal neighbourhoods (urban villages or outdated inner-city housing), those living in formal neighbourhoods (commercial housing, affordable housing or work unit housing neighbourhoods) displayed higher socioeconomic integration. Further research found that neighbourhood choice did not directly affect the socioeconomic integration of migrants in China, partly because migrants living in formal neighbourhoods established localized social capital (contacting local residents and government personnel, seeking help from them and increasing expenditures on local invitations and gifts) to promote better integration into the city, and they had a stronger willingness to settle down, which encouraged them to work harder, actively integrated into the mainstream society.

Study on the ArI-catalyzed intramolecular oxy-cyclization of 2-alkenylbenzamides to benzoiminolactones.

A new intramolecular oxy-cyclization of 2-alkenylbenzamides catalyzed by ArI has been developed. This protocol is highlighted by its metal-free catalytic system and extremely short reaction time, providing efficient and straightforward access to various benzoiminolactones in good to excellent yields. Interestingly, a regioselective transformation occurred when using two different reaction systems. Mechanistic studies suggested that mCPBA acts as both oxidant and ligand at the IIII center, and the Lewis acid BF3 accelerated ligand exchange and reductive elimination in the catalytic process.

Stream loss in an urbanized and agricultural watershed in China.

Stream losses are extensively observed due to human activities in the world, and the patterns of stream loss vary in different land use types. However, relationship between stream loss pattern and land use covers is poorly understood. We select the lower Taihu watershed (LTWS) within Yangtze River Delta (YRD), which is dominated by agricultural and urban covers and a typical case of most urbanized watersheds in China. In this study, we measured the stream loss of LTWS from 1960s to 2010s and investigated its relation to different land use covers and impervious area percentage (IAP) in order to figure out the main factor of stream loss in this area. The results show that urban area has tripled with fractional contribution from 10.3% to 33.18% in the form of conversion from agriculture to urban area during 1990-2015. 12.5% of all the streams are lost and 1st-order streams contribute most (91.8%) to the total stream loss. Urban cover contribute most (76%) to total streams loss compared to other land use types. We find that 1st-order streams have highest stream loss intensity, which is mainly caused by urban expansion, but preferred protections are given to highest-order streams. The linear model of correlation of pixel-level streams loss and IAP shows that the streams loss is statistically significant positive with IAP of cells (R2 = 0.91). Tradeoffs between city expansion and river network make small channels sacrifice for the urbanization. Urgent measures including legislation must be taken to protect small streams during urbanization nowadays and in future.

Perivascular adipose tissue dysfunction aggravates adventitial remodeling in obese mini pigs via NLRP3 inflammasome/IL-1 signaling pathway.

Perivascular adipose tissue (PVAT), a special type of adipose tissue, closely surrounds vascular adventitia and produces numerous bioactive substances to maintain vascular homeostasis. PVAT dysfunction has a crucial role in regulating vascular remodeling, but the exact mechanisms remain unclear. In this study, we investigated whether and how obesity-induced PVAT dysfunction affected adventitia remodeling in early vascular injury stages. Mini pigs were fed a high sugar and fat diet for 6 months to induce metabolic syndrome and obesity. In the mini pigs, left carotid vascular injury was then generated using balloon dilation. Compared with normal mini pigs, obese mini pigs displayed significantly enhanced vascular injury-induced adventitial responses, evidenced by adventitia fibroblast (AF) proliferation and differentiation, and adventitia fibrosis, as well as exacerbated PVAT dysfunction characterized by increased accumulation of resident macrophages, particularly the M1 pro-inflammatory phenotype, increased expression of leptin and decreased expression of adiponectin, and production of pro-inflammatory cytokines interleukin (IL)-1ß and IL-18. Primary AFs cultured in PVAT-conditioned medium from obese mini pigs also showed significantly increased proliferation and differentiation. We further revealed that activated nod-like receptor protein 3 (NLRP3) inflammasome and its downstream products, i.e., IL-1 family members such as IL-1ß and IL-18 were upregulated in the PVAT of obese mini pigs; PVAT dysfunction was also demonstrated in preadipocytes treated with palmitic acid. Finally, we showed that pretreatment with IL-1 receptor (IL-1R) antagonist or IL-1R knockdown blocked AF proliferation and differentiation in AFs cultured in PVAT-conditioned medium. These results demonstrate that obesity-induced PVAT dysfunction aggravates adventitial remodeling after early vascular injury with elevated AF proliferation and differentiation via activating the NLRP3/IL-1 signaling pathway.

Risk analysis of African swine fever in Poland based on spatio-temporal pattern and Latin hypercube sampling, 2014-2017.

BACKGROUND: African swine fever (ASF) is a devastating infectious disease of pigs. ASF poses a potential threat to the world pig industry, due to the lack of vaccines and treatments. In this study, the Geographic Information System (GIS) spatial analysis was applied to analyze the distribution, dispersion of the epidemic and clustering of ASF in Poland. RESULTS: The results show that the center of the epidemic moved gradually towards the southwest, and the distribution of the epidemic changed from south-north to east-west. Through space-time scan statistical analysis, the 3 clusters major of wild boar cases involve longer time spans and larger radii, while the other five with higher relative risks involved in domestic pigs. And then, a quantitative model was constructed to analyse the risk of releasing African swine fever virus (ASFV) from Poland by the legal export of pork and pork products. The Latin hypercube sampling results show that the probability is relatively low (the average value is 4.577 × 10- 7). CONCLUSIONS: All the identification of the spatio-temporal patterns of the epidemic and the risk analysis model would give a further understanding of the dynamics of disease transmission and help to design corresponding measures to minimize the catastrophic consequences of potential ASFV introduction.

Synthesis of deuterium-labeled 2-quinoxalinecarboxylic acid and 3-methylquinoxaline-2-carboxylic acid from deuterium aniline.

An efficient and simple synthetic route of deuterium-labeled 2-quinoxalinecarboxylic acid-d4 (QCA-d4 ) and 3-methylquinoxaline-2-carboxylic acid-d4 (MQCA-d4 ) is presented with 99.9% and 99.6% isotopic enrichment using aniline-d5 as labeled starting material. Their chemical structures were confirmed by 1 H NMR, and their isotopic abundance was determined by mass spectrometry analysis.

A Novel Zebrafish (Danio rerio) Assay for Assessing Musk Ambrette-Induced Toxicity.

Musk ambrette (4-tert-butyl-3-methoxy-2,6-dinitrotoluene) is a nitro musk, a cheap substitute for natural musk and a potential environmental pollutant based on its persistence, accumulation in human organisms. We investigated the acute toxicity of musk ambrette using wild-type AB and transgenic Tg(fli1a:EGFP)y1 zebrafish. Different concentrations were delivered to zebrafish by direct soaking from 6 to 72 h post-fertilization (hpf). The LC50 of musk ambrette was 76.4 µg mL-1. As musk ambrette concentration increased, zebrafish embryos showed developmental delays (50 µg mL-1, 22 hpf), pericardial edema (5 µg mL-1, 48 hpf), circulatory disturbances, curved body axis (1 µg mL-1, 72 hpf) and death (100 µg mL-1, 22 hpf). Target organ toxicity was evaluated by a zebrafish angiogenesis model. Musk ambrette induced cardiovascular morphological changes, vessel permeability variation, angiogenic changes and cardiotoxicity (10 µg mL-1, 48 hpf). The disappearance of caudal vein plexus confirmed the vascular development toxicity. Musk ambrette negatively affects early life-stage survival and demonstrates various toxicities in zebrafish.

Evaluation of the Lyophilized Platelets Function by Thromboelastography in an In Vitro Platelet Transfusion Model.

BACKGROUND: At present, liquid conserved platelets (PLTs) can only be stored at 22°C for up to 5 days. Waste of outdated PLTs and short supply of fresh PLTs were both seen in blood banks. Lyophilized PLTs were considered as one of the candidate replacements for liquid conserved PLTs. It is important to evaluate the function before it can be used in clinical trial. METHODS: In this study, an in vitro platelet transfusion model was established to evaluate the function of rehydrated lyophilized platelets (RLPs) by thromboelastography (TEG). Blood samples from 11 patients were spiked with 3 preparations of specific donors' apheresis platelets (stored at room temperature, frozen, and lyophilized) to an increment equivalent to transfusion with 3x10^11 platelets. Whole blood TEG assay was performed and the maximum amplitude (MA) value was used to evaluate the function of "transfused" platelets. RESULTS: The recovery of rehydrated lyophilized platelets (RLPs) in our study was 81.38% ± 2.38, and mean platelet volume (MPV) was 9.02 ± 0.54 fL. MA was significantly enhanced in the three different groups after the addition of PLTs when compared with the whole blood (WB) group. CONCLUSIONS: Our findings suggest that RLPs are capable of enhancing the MA value as well as fresh and frozen PLTs in vitro. The clinical significance of this remains to be determined.

Dynamic simulation of water resources in an urban wetland based on coupled water quantity and water quality models.

Water quality in wetlands plays a huge role in maintaining the health of the wetland ecosystem. Water quality should be controlled by an appropriate water allocation policy for the protection of the wetlands. In this paper, models of rainfall/runoff, non-point source pollution load, water quantity/quality, and dynamic pollutant-carrying capacity were established to simulate the water quantity/quality of Xixi-wetland river network (in the Taihu basin, China). The simulation results showed a satisfactory agreement with field observations. Furthermore, a 'node-river-node' algorithm that adjusts to the 'Three Steps Method' was adopted to improve the dynamic pollutant-carrying capacity model and simulate the pollutant-carrying capacity in benchmark years. The simulation result shows that the water quality of the river network could reach class III stably all year round if the anthropogenic pollution is reduced to one-third of the current annual amount. Further investigation estimated the minimum amount of water diversion in benchmark years under the reasonable water quantity-regulating rule to keep water quality as class III. With comparison of the designed scale, the water diversion can be reduced by 184 million m3 for a dry year, 191 million m3 for a normal year, and 198 million m3 for a wet year.

Involvement of calcium, reactive oxygen species, and ATP in hexavalent chromium-induced damage in red blood cells.

AIM: The aim of this study was to investigate the mechanisms of Cr(6+)-induced red blood cells (RBCs) damage. METHODS: The effect of Cr(6+) exposure on RBCs was evaluated by hemolytic rate and blood gas assays. After exposure to 20 µM Cr(6+), the percentage of phosphatidylserine (PS)-exposing cells, intracellular Ca(2+), reactive oxygen species (ROS), and ATP levels were evaluated, and cell morphology was observed. RBCs were exposed to Cr(6+) in different Ringer solutions to investigate the role of changes of Ca(2+), ROS, and ATP levels in eryptosis and morphology. RESULTS: The Cr(6+)-induced damage of RBCs was dose-dependent. After a 6 h incubation with Cr(6+), RBCs exhibited significant Ca(2+) influx, ROS increase, ATP depletion, and PS exposure, but displayed no obvious change in morphology at this time point. After 24 h Cr(6+) exposure, the RBCs decreased in size, appeared to be spike-like, and had decreased forward scatter. Inhibition of Ca(2+) influx attenuated PS-exposure caused by 6 h Cr(6+) exposure, but did not prevent 24 h Cr(6+) exposure-induced morphological change in RBCs. Inhibition of rapid ATP consumption using adenine significantly ameliorated Cr(6+)-caused PS-exposure at 12 h, 24 h and 48 h, and prevented 24 h Cr(6+) incubation-induced morphological change in RBCs. CONCLUSION: Cr(6+) can lead to eryptosis. Ca(2+) influx, increased ROS levels, and rapid ATP consumption are closely related to Cr(6+)-induced RBCs damage. Ca(2+) influx plays an extremely important role in Cr(6+)-mediated toxicity.

A dual-signaling surface-enhanced Raman spectroscopy ratiometric strategy for ultrasensitive Hg2+ detection based on Au@Ag/COF composites.

Heavy metal ion pollution poses significant risks to human health and ecological systems, and its monitoring is important. A sensitive and accurate surface-enhanced Raman spectroscopy (SERS) detection assay for Hg2+ was developed using Au@Ag/COF substrates and Y-shaped DNA labeled with two Raman reporters. The Au@Ag NPs in the COF produced robust and uniform E-fields, improving their detection reproducibility. The Y-shaped DNA design increased sensitivity with a low detection limit of 5.0 × 10-16 M by bringing the Raman reporter closer to the substrate surface. Additionally, the use of two Raman reporters allowed for a ratiometric method, improving detection accuracy by detecting both "signal-off" and "signal-on" signals. This selective sensor exhibited excellent recovery in river water, tap water, and milk samples, showcasing its robust biosensing capability for the detection of Hg2+ and its potential for sensing other heavy-metal ions in food and environmental applications.