Deficiency of leucine-rich repeat kinase 2 aggravates thioacetamide-induced acute liver failure and hepatic encephalopathy in mice.

BACKGROUND: Hepatic encephalopathy (HE) is closely associated with inflammatory responses. However, as a crucial regulator of the immune and inflammatory responses, the role of leucine-rich repeat kinase 2 (LRRK2) in the pathogenesis of HE remains unraveled. Herein, we investigated this issue in thioacetamide (TAA)-induced HE following acute liver failure (ALF). METHODS: TAA-induced HE mouse models of LRRK2 wild type (WT), LRRK2 G2019S mutation (Lrrk2G2019S) and LRRK2 knockout (Lrrk2-/-) were established. A battery of neurobehavioral experiments was conducted. The biochemical indexes and pro-inflammatory cytokines were detected. The prefrontal cortex (PFC), striatum (STR), hippocampus (HIP), and liver were examined by pathology and electron microscopy. The changes of autophagy-lysosomal pathway and activity of critical Rab GTPases were analyzed. RESULTS: The Lrrk2-/--HE model reported a significantly lower survival rate than the other two models (24% vs. 48%, respectively, p < 0.05), with no difference found between the WT-HE and Lrrk2G2019S-HE groups. Compared with the other groups, after the TAA injection, the Lrrk2-/- group displayed a significant increase in ammonium and pro-inflammatory cytokines, aggravated hepatic inflammation/necrosis, decreased autophagy, and abnormal phosphorylation of lysosomal Rab10. All three models reported microglial activation, neuronal loss, disordered vesicle transmission, and damaged myelin structure. The Lrrk2-/--HE mice presented no severer neuronal injury than the other genotypes. CONCLUSIONS: LRRK2 deficiency may exacerbate TAA-induced ALF and HE in mice, in which inflammatory response is evident in the brain and aggravated in the liver. These novel findings indicate a need of sufficient clinical awareness of the adverse effects of LRRK2 inhibitors on the liver.

Distribution and Probabilistic Risk Assessment of Antibiotics, Illegal Drugs, and Toxic Elements in Gastropods from Southeast China.

We investigated fourteen antibiotics, three illegal drugs, and two toxic elements in commercially available gastropods from southeast China. The data revealed high detection frequencies (DFs) for florfenicol (61.32%), florfenicol amine (47.33%), and thiamphenicol (39.88%), with maximum concentrations of 1110, 2222, and 136 µg/kg wet weight (ww), respectively. The DFs of illegal drugs were 3.54% for leucomalachite green and 0.3% for chloramphenicol. The average levels of Cd and As were 1.17 and 6.12 mg/kg ww, respectively. All chemicals presented diverse DFs in different sampling months. The highest DFs of florfenicol, florfenicol amine, and thiamphenicol were in July. The health risk assessment showed that targeted hazard quotients (THQs) of antibiotics, Cd, and As for children, teens, and adults were all less than one. Notably, the toxic elements (Cd and As) were identified as the primary health risk in gastropods, contributing to over 90% of the total THQs.

Antibiotic residues in commercial freshwater fish from southeast China: distribution and human health risk assessment.

We investigated 14 antibiotic residues in 8 marketed freshwater fish species from southeast China and estimated the associated health risks to local consumers. The antibiotic residues were determined by UPLC-MS/MS. Our findings revealed widespread distribution of quinolones (QNs), tetracyclines (TCs), and chloramphenicols (CAPs) in the freshwater fish. Notably, the average concentrations of enrofloxacin and ciprofloxacin reached levels as high as 62.5 µg/kg wet weight (ww) and 11.7 µg/kg ww, respectively, and detection frequencies were 68.7% for enrofloxacin and 31.6% for ciprofloxacin. Additionally, we detected chloramphenicol, a prohibited antibiotic, in samples with a detection frequency of 0.76%. Among the fish species, the mean concentration of total antibiotic residues was highest in bluntnose black bream (263.3 µg/kg), followed by English perch (52.4 µg/kg), crucian carp (46.3 µg/kg), black carp (28.6 µg/kg), yellowcheek carp (21.0 µg/kg), grass carp (15.3 µg/kg), bighead carp (3.78 µg/kg), and mandarin fish (3.69 µg/kg). We estimated the daily intake values of these antibiotic residues which were lower than the acceptable daily intake values and hazard indexes were much less than 1. It indicates that there is very low direct health risk to consumers. Despite that, investigation on the chronic impact, such as antibiotic-resistant bacteria, gut microbiota disruption, and allergic reactions, is urgently needed.

Toxic Elements in Beans from Zhejiang, Southeast China: Distribution and Probabilistic Health Risk Assessment.

This study described the distribution of As, Cd, Cr, Hg, and Pb in 692 bean samples from Zhejiang province, southeast China, and estimated the health risk using Monte Carlo simulation. The average levels of As, Cd, Cr, Hg, and Pb were 0.0349, 0.0379, 0.246, 0.0019, and 0.0246 mg kg-1. Correlation analyses showed very strong positive correlations for Cd-Pb in kidney beans and mung beans, Cd-As in black beans, and Pb-As in red beans. The target hazard quotients (THQs) were adopted for non-carcinogenic risk assessment, and THQs at the 50th percentile were all less than 1, indicating that there are no deleterious effects from rice exposure to these elements. When evaluating THQ for multiple elements, the certainty with a hazard index (HI) greater than 1 for children was 12.64%, for teens 11.54%, and for adults 1.01%. The sensitivity analysis reveals that the concentration of Cd in beans and ED (exposure duration) are the main principal factors that contributed to the total risk. The mean carcinogenic risks for children, teens, and adults were all less than 1 × 10-4, indicating no potential carcinogenic risk. Despite that, the routine monitoring of these elements, especially for Cd should be continued.

Dendrobine rescues cognitive dysfunction in diabetic encephalopathy by inhibiting ferroptosis via activating Nrf2/GPX4 axis.

BACKGROUND: Ferroptosis playsa crucial role in the development of dementia and dendrobine (Den)possesseshypoglycemic and neuroprotective effects. However, the character of ferroptosis in diabetic encephalopathy (DE) and Den's therapeutic effect remains unclear. PURPOSE: This study aimed to verify the effects of Den on ferroptosis in treating DE and underlying mechanisms. STUDY DESIGN: Den's therapeutic effect was assessed in db/db mice and advanced glycation end products (AGEs)-induced HT22 cells. METHODS: After oral administration with Den orMetformin for 8-week, behavioral tests were used to assess cognitive capacity. Then, biochemical analysis was preformed to detect glucose and lipid metabolism levels; histological analysis and transmission electron microscope were applied to evaluate pathological injuries. Meanwhile, EdU staining and flow cytometry were applied to test cell apoptosis. Furthermore, mitochondrial dynamics, iron transport, and Nrf2/GPX4 axis related proteins were detected by western blot or immunofluorescence. RESULTS: Our results demonstrated that Den remarkably alleviated glucose and lipid metabolism disorders, as well as ameliorated mnemonic deficits of db/db mice. Meanwhile, Den could protect AGEs-induced HT22 cells from death and apoptosis. In addition, we noted that Den inhibited lipid peroxidation by restoring mitochondrial function and reducing reactive oxygen species production. Furthermore, ferroptosis was proven to exist in db/db mice brain and Den could inhibit it via activating Nrf2/GPX4 axis. CONCLUSION: These findings indicated that Den could rescue cognitive dysfunction in DE by inhibiting ferroptosis via activating Nrf2/GPX4 axis.

Analytical Method Optimization of Tetrodotoxin and Its Contamination in Gastropods.

Tetrodotoxin (TTX) is an extremely potent marine biotoxin. An analytical method was developed for both trace contamination and extremely high levels of TTX in gastropods by liquid chromatography-tandem mass spectrometry (LC-MS/MS) with clean-up of cation exchange solid phase extraction (SPE) in this study. The limit of detection (LOD) in the sample matrix was 0.5 µg/kg. With the calibration of a screened internal standard (validamycin, IS), the linear range was 0.1-100 ng/mL (1.5-1500 µg/kg in sample matrix) with a correlation coefficient of r2 > 0.999. The average recoveries at three spiking levels (1.5 µg/kg, 44 µg/kg, and 1500 µg/kg) were 82.6-94.4% with relative standard deviations (RSDs) less than 8.4%. TTX levels in seven gastropods (741 samples) were studied. The contamination and analogues in Neverita didyma (N. didyma, 565 samples collected in Zhejiang province, China, from 2016 to 2022) were first reported. The detection rate of TTX in N. didyma was 34.2%. The average concentration was 23.1 µg/kg, and the maximum value was 2327 µg/kg. The time distribution study indicated that high contaminations of TTX occurred from May to August for N. didyma.

Quantification of 37 glucocorticoids in chicken muscle by UHPLC-Q-Orbitrap-MS with parallel reaction monitoring.

The quantification capability of high-resolution mass spectrometry (HRMS) has received increasing interest from analysts. In this study, we present a method for analyzing 37 glucocorticoids in chicken muscle using UHPLC-Q-Orbitrap MS with parallel reaction monitoring (PRM). The analytes were extracted using acetonitrile (ACN) containing 0.1% formic acid and subjected to commercial PRiME HLB solid-phase extraction (SPE) cartridge clean-up. Under optimized conditions, the analytes were separated on an analytical column and subsequently detected using a high-resolution hybrid quadrupole/Orbitrap mass spectrometer coupled with PRM scan mode. The Q-Orbitrap with PRM exhibited remarkable sensitivity, with limits of quantification (LOQs) ranging from 0.08 µg kg-1 to 7.59 µg kg-1. To validate the method, we conducted intra- and inter-day tests using a blank matrix sample at different spiking levels. The achieved results demonstrated satisfactory recovery values (74.1-97.5%) and precise results (RSDs < 15%) for all the studied analytes. In application, we found dexamethasone with 6.5 µg kg-1 and fluorometholone with 3.9 µg kg-1 in two chicken samples. These findings suggest that the UHPLC-Q-Orbitrap system, in conjunction with the SPE sample preparation method, has great potential as a routine quantification approach for multiple glucocorticoid residues in chicken samples.

Heavy metals accumulation in bivalve mollusks collected from coastal areas of southeast China.

The distribution of six heavy metal and metalloids (As, Cd, Cr, Hg, Ni and Pb) was analyzed in 597 bivalve mollusks (8 species) collected from coastal areas of southeast China. Target hazard quotient, total hazard index, and target cancer risk were calculated to evaluate potential human health risks from bivalve consumption. The mean concentrations of As, Cd, Cr, Hg, Ni and Pb were 1.83, 0.581, 0.111, 0.0117, 0.268 and 0.137 mg kg-1 wet weight in bivalves. The average estimated daily intakes for As, Cd, Cr, Hg, Ni and Pb were 1.156, 0.367, 0.07, 0.007, 0.167 and 0.087 µg kg-1 body weight/day. Health risk assessment showed that there was no non-carcinogenic health risk to general residents to these metals from consumption of bivalves. Cd intake through mollusks posed a potential cancer risk. Accordingly, regular monitoring for heavy metals, especially Cd is recommended with respect to potential contaminant on marine ecosystems.

Distribution of Cadmium in Fresh Vegetables Marketed in Southeast China and Its Dietary Exposure Assessment.

This study investigated concentrations of cadmium (Cd) in 2465 vegetable samples (52 species) from 2018 to 2022 and estimated the associated health risk for local consumers. The average concentration of Cd was 0.035 mg kg-1, and the percentage of samples exceeding the Chinese maximum allowed concentration was 3.89% (96/2465). The top five species with highest Cd levels were Lilium brownii F (0.182 mg kg-1), Allium chinense G (0.117 mg kg-1), Allium macrostemon Bunge (0.105 mg kg-1), Colocasia esculenta (0.064 mg kg-1), and Amaranthus tricolor L (0.054 mg kg-1). Bulb vegetables had a higher relative accumulation of Cd compared to other vegetables. The levels of Cd in vegetables varied significantly across sampling areas and years. The mean estimated daily intake (EDI) of cadmium through consumption of vegetables was 0.519 µg kg-1 bw per day for adults and 0.217 µg kg-1 bw per day for children. The target hazard quotients (THQs) were all less than the threshold of 1 for both adults and children. This indicates that there is low health risk for Cd through vegetable consumption. However, routine monitoring of Cd levels in food is still crucial to ensure food safety and protect public health.

Determination of steroid hormone residues in farmed fish using high-resolution orbital ion trap mass spectrometry.

A method for the determination of 15 steroid hormones in farmed fish by liquid chromatography-orbital ion trap mass spectrometry has been developed and validated. The method involved sample preparation with acetonitrile extraction and clean-up, and separation in the LC using a C18 column. The orbital ion trap MS was operated at a resolution of 35 000 FWHM in selected ion monitoring mode. An ion source with heated electrospray ionization was used in positive ionization mode. The samples were prepared by solid-phase extraction. The limit of quantification of steroid hormones in fish samples was 2 µg kg-1. Good linearity was observed since correlation coefficients were more than 0.99 for all compounds. Recoveries of spiked fish samples (2 µg kg-1 and 20 µg kg-1) ranged from 80.8% to 112.6% with relative deviations less than 15%. The method was successfully applied to detect steroid hormones in real farmed fish samples at the µg kg-1 level.

Distribution and safety assessment of heavy metals in fresh meat from Zhejiang, China.

There are increasing concerns on heavy metals in animal derived foods. We analyzed the levels of As, Cd, Cr, Cu, Hg, Ni, and Pb in 1066 fresh meat samples including pork, beef, mutton, chicken and duck from Zhejiang province, southeast China. The average levels of As, Cd, Cr, Cu, Hg, Ni, and Pb were 0.018, 0.002, 0.061, 0.801, 0.0038, 0.055, and 0.029 mg/kg wet weight respectively. There are significant positive correlations among Cd, Hg and Pb (P < 0.05) and negative correlations for Cu-Pb or Cu-Cd (P < 0.05). The exposure assessment showed that the health risk to humans by consuming these meat products was relatively low. However, regular monitoring of heavy metals in meat products is still recommended considering their intensive industrial activities.

[Seasonal Variation and Sources Identification of Dissolved Sulfate in a Typical Karst Subterranean Stream Basin Using Sulfur and Oxygen Isotopes].

Karst water, which provides approximately 25% of the world's drinking water, is especially vulnerable to anthropogenic pollutants. To determine the variations between high and low flow periods and the sources of dissolved sulfate (SO42-) in small karst basins, SO42- concentrations, stable sulfur and oxygen isotopes (δ34S-SO4 and δ18O-SO4), and oxygen isotopes of water (δ18O-H2O) were investigated in surface and groundwaters, during the high and low flow seasons, within the Babu subterranean stream basin. Analysis showed that: ① the water samples that were directly impacted by acid mine drainage exhibited high SO42- concentrations (≥250 mg·L-1) and significant seasonal variation, while the seasonal variation of non-AMD-impacted water with low SO42- concentrations was not significant. ② During the high flow season, the mean δ34S-SO4 and δ18O-SO4 values of surface water were -10.5‰ and 4.7‰, respectively, and -11.5‰ and 1.3‰ during the low flow period; the mean values of δ34S-SO4 and δ18O-SO4 in groundwater samples were -2.9‰ and 7.1‰ during the high flow period, respectively, and -3.2‰ and 6.2‰ during the low flow period. Both surface and groundwater samples exhibited higher δ34S-SO4 and δ18O-SO4 values during the high flow period than during the low flow period. ③ The values of δ34S-SO4 in the surface and groundwater samples were relatively stable, indicating that the sources of SO42- at specific sampling sites were stable.④ The main sources of SO42- in surface and groundwaters were rain, sulfide, and gypsum, accounting for 13%, 40%, and 47%, respectively, of SO42- in samples taken from the basin outlet during the high flow season, and 18%, 39%, and 43%, respectively, in samples obtained during the low flow season.

Health risk assessment of heavy metals in marine fish to the population in Zhejiang, China.

Environmental pollution with toxic metals can lead to the possible contamination of the marine fish. We investigated the levels of As, Cd, Cr, Hg and Pb in 652 marine fish samples (15 species) collected from coastal areas of Zhejiang, China and estimated their health risk. Mean concentrations of As, Cd, Cr, Hg and Pb were 0.783, 0.009, 0.114, 0.031, 0.043 mg/kg wet weight. The average estimated daily intakes (EDIs) for As, Cd, Cr, Hg and Pb were 1.214, 0.014, 0.177, 0.048 and 0.067 µg/kg bw/day. The risk assessment at mean exposure level showed that there was no health risk associated with these elements through consumption of marine fish. However, potential health risk may exist for high exposure consumers considering the possible contamination of As and Hg. Given that the different levels of certain elements in marine fish in China, this study provides a scientific basis for food safety assessment and suggestions for risk management.

[Sources and Fate of Nitrate in Groundwater in a Typical Karst Basin: Insights from Carbon, Nitrogen, and Oxygen Isotopes].

Multiple isotopes (C, N, and O) and hydrochemical data were used to trace the sources and fate of nitrate in ground and surface waters of the Babu subterranean stream watershed in Guizhou Province. The origin of nitrate in the water samples was also quantitatively analyzed by the SIAR model. Approximately 38% of the groundwater samples were not drinkable because the nitrate exceeded the drinking water standard, thereby indicating that the groundwater was seriously polluted by nitrate. The ranges of δ15N-NO3, δ18O-NO3, and δ18O-H2O in groundwater were 2.30‰-30.33‰ (mean of 9.68‰), 2.65‰-13.73‰ (mean of 6.64‰), and -8.83‰ï¹£-7.37‰ (mean of -8.18‰), respectively. Based on the stable isotopic compositions (δ15N-NO3, δ18O-NO3, and δ18O-H2O), nitrification was the dominant process in the basin. The nitric acid produced by nitrification promoted the dissolution of carbonate rocks, thereby leading to a significantly negative correlation (P<0.001) between the carbon isotope of dissolved inorganic carbon (δ13CDIC) and δ15N-NO3 and indicating that δ13CDIC, combined with δ15N-NO3, is effective in exploring the fate of nitrate in karst groundwater. The nitrate in the ground and surface waters mainly originated from soil N, manure and sewage, and ammonium nitrogen fertilizer. The results of the SIAR model showed that the contributions of soil N, manure and sewage, and ammonium nitrogen fertilizer were 36.19%, 33.71%, and 30.10% in groundwater, respectively, and 39.15%, 36.08%, and 24.77% in surface water, respectively. Therefore, it would be more effective to reduce the nitrate recharge flux in groundwater by simultaneously removing nitrate and ammonium nitrogen during wastewater treatment and by adopting scientific fertilization technology in agricultural areas.

Protective effect and possible mechanisms of ligustrazine isolated from Ligusticum wallichii on nephropathy in rats with diabetes: A preclinical systematic review and meta-analysis.

ETHNOPHARMACOLOGICAL RELEVANCE: Ligusticum wallichii has been used to treat renal diseases for thousands of years in China. Ligustrazine (Lig) is the active ingredient of Ligusticum wallichii that possesses a variety of biological activities against kidney disease. AIM OF THE STUDY: The purpose of this review is to further evaluate whether the supplementation with Lig has an effect on improving renal pathology, renal function indexes and blood glucose levels in animal model of diabetic nephropathy (DN). Potential mechanisms of Lig for DN as well as the existing problems regarding the modeling method and limitations in this area of research were also summarized. MATERIALS AND METHODS: The Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) checklist was used to organize the search of eight databases from inception to June 2019. We used Cochrane Collaboration's 10-item checklist and Rev-Man 5.3 software to analyze the data as well as risk of bias. RESULTS: The study quality scores ranged from 2 to 6 points with an average of 4.471. Compared with the control group, Lig significantly improved pathological changes of kidney including glomeruli and tubules, and induced significant decreases in levels of blood urea nitrogen, serum creatinine, 24-h urinary albumin and HbA1c, as well as increasing creatinine clearance rates. In subgroup analysis, the groups of high-dose STZ (≥60 mg/kg) and longer period of Lig treatment (>8 w) showed better results than those of the control group. No difference was seen between the high (>150 mg/kg, QD) and low (≤150 mg/kg, QD) dose of Lig treatment groups. CONCLUSION: Lig exerts renoprotective functions in an animal model of DN mediated by antioxidant action, inhibition of apoptosis, anti-inflammatory action, reduction of renal fibrosis, reduction of the proliferation of mesangial cells, inhibition of endotheliosis, inhibition of atherosclerosis and promotion of renal autophagy. The positive conclusion should be treated cautiously because of various methodological flaws. Further studies are recommended according to ARRIVE guidelines. The method of modeling with high-dose STZ should be avoided and improved STZ modeling schemes are recommended. Considering the large dosage range of Lig used clinically and in animals, the future studies on the basis of animal renal histology are urgently needed to determine the optimal dosages to delay histological changes. Nevertheless, together, our findings suggest that Lig is a renoprotective candidate drug for treatment of DN.

[Geochemical Characteristics and Ecological Significance of Carbon Isotopes in Groundwater Under the Influence of Different Land Use Types in Karst Areas].

Based on the seasonal characteristics of groundwater hydrochemistry and the carbon isotopes (δ13C) of dissolved inorganic carbon (DIC) in the Hongjiadu Basin, Guizhou Province, this paper discusses the natural processes and anthropogenic factors affecting the characteristics of δ13CDIC in karst groundwaters under different land use types. The results show that the main sources of DIC in groundwater are carbonate weathering and soil CO2. In winter, the δ13CDIC values for groundwater ranged from -14.8‰ to -4.1‰ with an average of -10.1‰ and, in summer, ranged from -14.5‰ to -6.3‰ with an average of -10.2‰. Sulfuric acid from sulfide oxidation in coal-bearing strata and acid rain is involved in carbonate weathering, resulting in the enrichment of groundwater with heavy carbon isotopes. Due to the soil CO2 effect, the δ13CDIC values of woodland groundwater experiencing less disturbance from human activities are lower in summer than in winter. The degradation of organic matter input from residential areas is a significant contributor of DIC to groundwater. The average values of δ13CDIC in winter and summer were -11.9‰ and -11.6‰, respectively, and the seasonal difference was relatively small in residential areas. During different seasons and for different types of land use, human activities could lead to differences in groundwater δ13CDIC values and hydrochemistry. Therefore, δ13CDIC can reflect the impact of human activities on karst aquifers, which has important ecological significance.

[Spatial and Temporal Variations in Fertilizer Use Across Prefecture-level Cities in China from 2000 to 2015].

Chemical fertilizer plays an important role in increasing grain production in agricultural systems but overuse also brings a series of environmental problems, such as eutrophication of surface water, deterioration of soil structure, and the decline of agricultural carrying capacity. At present, research on chemical fertilizer use mainly focuses on utilization efficiency while studies on the spatial characteristics of its use are limited. It is also of great significance for the sustainable development of agriculture in China to fully understand the spatial changes in the use of chemical fertilizers. Based on data of pure chemical fertilizer use, sown area, and grain yield in prefecture-level cities from 2000 to 2015, spatial autocorrelation analysis, cold and hot spot analysis, nuclear density analysis, and standard deviation ellipse analysis were applied. The temporal and spatial variations in total fertilizer use and fertilizer load per unit area in 2000, 2005, 2010, and 2015 were compared. The results showed that:① The use of chemical fertilizer in China increased linearly from 2000 to 2015 but it has been in a relatively high agglomeration state in the region. The pure use of chemical fertilizer experienced a process of increasing regional aggregation from 2000 to 2005, weakening from 2005 to 2010, and increasing from 2010 to 2015. ② From a spatial perspective, the total amount of chemical fertilizer applied between 2000 and 2015 showed an increasing trend, shown by an increase in the number of prefecture-level cities and regions in which the use of chemical fertilizer exceeded the standard. The eastern regions of China, which have experienced rapid economic development, such as Guangdong Province and Fujian Province, are over the critical load of chemical fertilizer more and denser than other prefecture-level cities because the proportional reduction in sown area is greater than the increase in chemical fertilizer use. ③ The movement track of the grain production center in China from 2000 to 2015 was not consistent with the movement track of chemical fertilizer usage. Specifically, the center of grain production moves to the northeast, while the center of chemical fertilizer use moves to the west. This demonstrates that the status of commercial grain production in Northeast China is becoming more and more important, and that the use of chemical fertilizer in the western regions of China is gradually increasing. Here, there is a trend for exceeding the standard, which required further attention.

Screening of multi-class antibiotics in pork meat by LC-Orbitrap-MS with modified QuEChERS extraction.

The quantification capability of high resolution mass spectrometry is of great interest to analysts. We described a method for analysis of multi-class antibiotics in pork meat by UPLC-quadrupole (Q)-Orbitrap-MS. The QuEChERS approach with a clean-up step using a sorbent of primary-secondary amine (PSA) and C18 was adopted for sample preparation, and 37 antibiotics including beta-lactams, tetracyclines, sulfonamides, fluoroquinolones and macrolides were analyzed. The Q-Orbitrap method showed high sensitivity with limits of detection (LODs) ranging from 0.8 µg kg-1 to 2.9 µg kg-1. The method was further validated by intra and inter-day tests with fortified samples. Recovery (85-105.6%) and precision values (RSDs < 15%) for all analytes were obtained. The result indicates that UPLC-Q-Orbitrap-MS coupled with QuEChERS preparation can serve as a routine method for multi-class antibiotic analysis in pork meat.

The use of in-strip digestion for fast proteomic analysis on tear fluid from dry eye patients.

Tear is an accessible fluid for exploring biomarkers of dry eye disease. This study describes a fast proteomic method by LC-Q-orbitrap-MS analysis with in-strip digestion and investigates the tear proteome of dry eye patients. Schirmer's strips were used for collection of tear fluid from patients. These strips were cut into pieces and directly digested with trypsin before mass spectrometry analysis. The data showed that more than 50 proteins were found in tear fluid from dry eye patients. Gene Ontology (GO) annotation showed that most of proteins were transfer/carrier proteins, hydrolyses, enzyme modulators and signaling molecules. Targeted proteomics strategy revealed that 18 proteins were differentially expressed in dry eye patients. Furthermore, it was showed that the common post-translational modification in tear proteins is deamidation of Asn.