Photon-counting Detector CT for Liver Fat Quantification: Validation across Protocols in Metabolic Dysfunction-associated Steatotic Liver Disease.

Background Traditional energy-integrating detector CT has limited utility in accurately quantifying liver fat due to protocol-induced CT value shifts, but this limitation can be addressed by using photon-counting detector (PCD) CT, which allows for a standardized CT value. Purpose To develop and validate a universal CT to MRI fat conversion formula to enhance fat quantification accuracy across various PCD CT protocols relative to MRI proton density fat fraction (PDFF). Materials and Methods In this prospective study, the feasibility of fat quantification was evaluated in phantoms with various nominal fat fractions. Five hundred asymptomatic participants and 157 participants with suspected metabolic dysfunction-associated steatotic liver disease (MASLD) were enrolled between September 2023 and March 2024. Participants were randomly assigned to six groups with different CT protocols regarding tube voltage (90, 120, or 140 kVp) and radiation dose (standard or low). Of the participants in the 120-kVp standard-dose asymptomatic group, 51% (53 of 104) were designated as the training cohort, with the rest of the asymptomatic group serving as the validation cohort. A CT to MRI fat quantification formula was derived from the training cohort to estimate the CT-derived fat fraction (CTFF). CTFF agreement with PDFF and its error were evaluated in the asymptomatic validation cohort and subcohorts stratified by tube voltage, radiation dose, and body mass index, and in the MASLD cohort. The factors influencing CTFF error were further evaluated. Results In the phantoms, CTFF showed excellent agreement with nominal fat fraction (intraclass correlation coefficient, 0.98; mean bias, 0.2%). A total of 412 asymptomatic participants and 122 participants with MASLD were included. A CT to MRI fat conversion formula was derived as follows: MRI PDFF (%) = -0.58 · CT (HU) + 43.1. Across all comparisons, CTFF demonstrated excellent agreement with PDFF (mean bias values < 1%). CTFF error was not influenced by tube voltage, radiation dose, body mass index, or PDFF. Agreement between CTFF and PDFF was also found in the MASLD cohort (mean bias, -0.2%). Conclusion Standardized CT value from PCD CT showed a robust and remarkable agreement with MRI PDFF across various protocols and may serve as a precise alternative for liver fat quantification. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Wildman-Tobriner in this issue.

Childhood adversities and memory function in later life: the mediating role of activity participation.

BACKGROUND: Childhood adversities may lead to decreased activity participation in later life, impacting memory health in ageing adults. Childhood adversities related to deprivation and threat, as conceptualized by the Dimensional Model of Adversity, can exhibit distinct impacts on cognitive and emotional outcomes in children and younger adults. This study examined the potential influence of childhood deprivation and threat on memory function in later life and the mediating role of activity participation in these relationships. METHODS: This study used data from the first wave of Panel Study of Active Ageing and Society (PAAS), a representative survey of Hong Kong residents aged 50 or above (N = 1,005). Key variables included late-life memory function measured by delayed recall test, deprivation- and threat-related childhood adversities, and the frequency of participation in informal and formal types of activities. Mediation tests were used for analysis. RESULTS: Childhood deprivation was associated with a lower late-life memory function, whereas threat was not. The negative effects of childhood deprivation and its subdomain, economic hardship, on memory function were mediated by activity participation. Total participation scores presented the strongest mediating effect (17.3-20.6%), with formal activities playing a more substantial mediating role than informal activities in mitigating the effect of childhood deprivation. CONCLUSIONS: These findings expand the applicability of the Dimensional Model of Adversity to ageing populations, highlighting the influence of deprivation on life-long cognitive development. Furthermore, this study revealed an indirect mechanism by which childhood deprivation affects memory health in old age through diverse activity participation.

COVID-19 infection, resilience, and depressive symptoms: the protective role of family functioning for aging Chinese adults in Hong Kong.

OBJECTIVES: Older adults are at an elevated risk of experiencing long COVID, with post-COVID-19 depressive symptoms being prevalent. However, the protective factors against this remain understudied. This study examined (a) the role of resilience in the association between COVID-19 infection and depressive symptoms in aging adults; (b) the moderating role of family functioning in the relationships between COVID-19 and resilience and between resilience and depressive symptoms; and (c) potential gender differences in the moderation. METHOD: Data were drawn from the first wave of the Panel Study of Active Ageing and Society, a representative survey of Hong Kong adults aged 50 or above. Mediation and moderated mediation analyses were conducted. RESULTS: Approximately 35% of the participants had tested positive for COVID-19. Resilience significantly mediated the association between COVID-19 infection and post-COVID-19 depressive symptoms (p < 0.001). Family functioning was a significant moderator: the COVID-19-resilience association was stronger, and the resilience-depressive symptoms association was weaker among participants with higher family functioning. The moderating role of family functioning was more salient in women than in men. CONCLUSION: Resilience can protect aging adults from post-COVID-19 depressive symptoms. Interventions for enhancing family functioning may promote the formation of resilience, especially among older women.

Bifunctionalization of styrene through ring-opening-recombination strategy of phenylpropathiazole salt.

By opening the ring of a benzothiazole salt, we provide a sulfur source for the bifunctional reaction of styrene. The ring-opening-recombination reaction of the benzothiazole salt simultaneously constructs new C-S, C-O, and CO bonds after C-S bond breaking. The reaction proceeds in green solvents, requires no transition metal catalyst, and is compatible with many functional groups.

Highly Transparent Poly(vinyl alcohol)(PVA)/TiO2 Nanocomposite Films with Remarkable Photocatalytic Performance and Recyclability.

Titanium dioxide (TiO2) has been regarded as an efficient photocatalyst for degradation of environmental pollutants. However, recovery of TiO2 nanoparticles from suspension limits its practical application. Herein, we reported a novel highly transparent poly(vinyl alcohol)(PVA)/TiO2 photocatalytic film via in-situ growth and solution casting method. TiO2 nanoparticles with average size of 10 nm were uniformly dispersed in transparent PVA matrix. The photocatalytic performance was investigated by photodegradation of methyl orange (MO) aqueous solution under solar light irradiation. PVA/TiO2 photocatalytic film exhibited remarkably high photocatalytic activity and excellent recyclable properties during multi-cycle use. PVA not only acted as a transparent supports for TiO2, but also worked as an efficient holes scavenger. The hydroxyl groups on PVA chains played a key role in separation of photo-generated electrons and holes, thus increased the photodegradation rate of MO. This work gives an easy and reliable way for polymer/TiO2 nanocomposites in practical environmental applications.

A Layer-by-Layer Self-Assembled Bio-Macromolecule Film for Stable Zinc Anode.

Side reactions on zinc metal (Zn) anodes are formidable issues that cause limited battery life of aqueous zinc-ion batteries (AZIBs). Here, a facile and controllable layer-by-layer (LbL) self-assembly technique is deployed to construct an ion-conductive and mechanically robust electrolyte/anode interface for stabilizing the Zn anode. The LbL film consists of two natural and biodegradable bio-macromolecules, chitosan (CS) and sodium alginate (SA). It is shown that such an LbL film tailors the solvation sheath of Zn ions and facilitates the oriented deposition of Zn. Symmetric cells with the four double layers of CS/SA ((CS/SA)4 -Zn) exhibit stable cycles for over 6500 h. The (CS/SA)4 -Zn||H2 V3 O8 coin cell maintains a specific capacity of 125.5 mAh g-1 after 14 000 cycles. The pouch cell with an electrode area of 5 × 7 cm2 also presents a capacity retention of 83% for over 500 cycles at 0.1 A g-1 . No obvious dendrites are observed after long cycles in both symmetric and full cells. Given the cost-effective material and fabrication, and environmental friendliness of the LbL films, this Zn protection strategy may boost the industrial application of AZIBs.

Prescription of Nonpharmacologic Interventions in Memory Clinics: Data from the Clinical Pathway for Alzheimer's Disease in China (CPAD) Study.

OBJECTIVES: Nonpharmacologic interventions are recommended to improve outcomes in dementia. Little is known about their prescription in practice, especially in non-Western populations. We investigated individual- and institution-level characteristics associated with nonpharmacologic interventions prescription in China. DESIGN: A multicenter observational study. SETTING AND PARTICIPANTS: This study used cross-sectional data from 889 community-dwelling outpatients living with dementia aged ≥45 years from a multicenter registry of 28 memory clinics in China. METHODS: Prescription records of nonpharmacologic interventions, carer and clinic characteristics, and reasons for declining interventions were collected. Multilevel logistic regression was used to identify factors associated with the prescription. RESULTS: Nonpharmacologic interventions were prescribed in 323 people (36.3%) with mild cognitive impairment or dementia. Cognitive activities and carer training/support were the most prescribed interventions. Multilevel logistic regression showed that 73% of the variance in prescription was attributed to institutional characteristics of the memory clinic. Greater caregiving gain [odds ratio (OR), 1.05; 95% CI, 1.02-1.09], lower burden (OR, 0.97; 95% CI, 0.95-1.00), worse carer-perceived dyad relationship (OR, 0.83; 95% CI, 0.70-0.99), and family history of dementia (OR, 2.08; 95% CI, 1.19-3.65) were individual-level factors associated with prescription. Among 440 people considered having a need but received no prescription, declined by user/carer was the main reason for not prescribing (70.7%). Skepticism about effectiveness by physicians/carers and carers being unable or lacking resources to use the interventions were the common reasons given. CONCLUSIONS AND IMPLICATIONS: A relatively low prescription rate of nonpharmacologic interventions is related to both individual- and institution-level factors. Carer support and education, instrumental support, and prescription guidelines across specialties and sites are possible strategies to improve access to nonpharmacologic interventions in dementia care.

Improving the creation of SiV centers in diamond via sub-µs pulsed annealing treatment.

Silicon-vacancy (SiV) centers in diamond are emerging as promising quantum emitters in applications such as quantum communication and quantum information processing. Here, we demonstrate a sub-µs pulsed annealing treatment that dramatically increases the photoluminescence of SiV centers in diamond. Using a silane-functionalized adamantane precursor and a laser-heated diamond anvil cell, the temperature and energy conditions required to form SiV centers in diamond were mapped out via an optical thermometry system with an accuracy of ±50 K and a 1 µs temporal resolution. Annealing scheme studies reveal that pulsed annealing can obviously minimize the migration of SiV centers out of the diamond lattice, and a 2.5-fold increase in the number of emitting centers was achieved using a series of 200-ns pulses at a 50 kHz repetition rate via acousto-optic modulation. Our study provides a novel pulsed annealing treatment approach to improve the efficiency of the creation of SiV centers in diamond.

[Determination of tetrodotoxin in seafood using graphitized carbon black clean-up with hilic ultra performance liquid chromatography-triple quadrupole mass spectrometry].

OBJECTIVE: To develop a rapid hilic ultra performance liquid chromatography (UPLC)-mass spectrum (MS)/MS method for determination of tetrodotoxin in seafood. METHODS: The sample of muscle and liver of puffer fish and nassarius were extracted with aqueous solution containing 0.2% (V/V) acetic acid (the extract of liver must be purified through HLB cartridge), and then cleanup of extract was accomplished by solid-phase extraction with a graphitized carbon black cartridge. The analysis of tetrodotoxin was carried out on a chromatographic column (Acquity UPLC BEH Amide, 100 mm×2.1 mm×1.7 µm) with gradient elution of 95% (V/V) acetonitrile-H2O both containing 0.1% (V/V) formic acid and 2.0 mmol/L ammonium formate, and detected by positive electrospray ionization tandem mass spectrometry in the multiple reaction monitoring (MRM) mode, and quantified by matrix-match standard solution. RESULTS: The calibration curves were linear in the range of 30 - 10 000, 50 - 10 000 and 30 - 10 000 µg/kg of tetradotoxin in muscle and liver of puffer fish and in muscle of nassarius, respectively. The correlation coefficients were within 0.9963 - 0.9990. The limits of detection were 10, 20 and 10 µg/kg, and that of quantitation were 30, 50 and 30 µg/kg for muscle and liver of puffer fish and muscle of nassarius, respectively. The average recoveries were 81.5% - 93.1%, 82.3% - 106.0% and 83.5% - 95.2% for tetrodotoxin spiked in muscle and liver of puffer fish and in muscle of nassarius, respectively, with relative standard deviation (RSD) of 2.3% - 11%, 4.3% - 14.0% and 3.5% - 13.0% (n = 6). CONCLUSION: The method was simple, accurate and sensitive, and could be successfully applied to the measurement of tetrodotoxin in puffer fish and nassarius.

Research on the evaluation method of steam power system operation status based on the theory of deterioration degree and health value.

The evaluation of the steam power system is very important for the operator to understand the operating status of the system, but the lack of consideration of the fuzziness of the complex system and the impact of the indicator parameters on the whole system makes the evaluation difficult. In this paper, an indicator system for evaluating the operation status of the experimental supercharged boiler is established. After discussing several methods of parameter standardization and weight correction, a comprehensive evaluation method based on the deterioration degree and health value is proposed while considering the deviation of the indicator and the fuzziness of the system. The comprehensive evaluation method, the linear weighting method and the fuzzy comprehensive evaluation method are respectively used to evaluate the experimental supercharged boiler. The comparison of the three methods shows that the comprehensive evaluation method is more sensitive to minor anomalies and faults and can draw quantitative health assessment conclusions.

[Isolation and identification of shellfish toxins from contaminated blue mussel (Mytilus edulis) from the East China Sea].

OBJECTIVE: To investigate the contamination of shellfish poisoning of mussels, the poisonous constituents in that were isolated and identified. METHODS: The mussel tissue homogenate was extracted by acetone, and then the acetone extract was partitioned between diethyl ether and water. The ether extract was fractionated by column chromatography over silica gel and further isolated by semi-preparative RP-HPLC, monitored by ultra performance liquid chromatography coupled with triple quadrupole mass spectrometry. RESULTS: Four poisonous constituents were isolated. Two of them were elucidated as pectenotoxin-2 seco acid and 7-epi-pectenotoxin-2 seco acid, respectively, on the basis of mass spectral data and compared with the production of enzymatic hydrolysis of PTX-2, and others were identified as okadaic acid and dinophysistoxin-1 by UPLC-MS/MS analysis compared with standard substances. CONCLUSION: OA, DTX-1, 7-epi-PTX-2sa and PTX-2sa had been isolated from the mussel, respectively. The concentrations of free OA, DTX-1 and total OA in which were surpassed the maximum permitted levels in EU. OA and DTX-1 were confirmed to be the main toxins responsible for this DSP outbreak.

[Highly sensitive determination of three kinds of amanitins in urine and plasma by ultra performance liquid chromatography-triple quadrupole mass spectrometry coupled with immunoaffinity column clean-up].

Cases of toxic mushroom poisoning occur frequently in China every year. In particular, mushrooms containing amanitins can cause acute liver damage, with high mortality rates. The symptoms of acute liver damage are experienced 9-72 h after consumption of the mushrooms. At this time, the concentration of amanitins in blood and urine is too low to be detected even by the highly sensitive ultra performance liquid chromatography-triple quadrupole mass spectrometry (UPLC-MS/MS), thus rendering clinical diagnosis and treatment difficult. To this end, a method was developed for the determination of α-amanitin, ß-amanitin and γ-amanitin in urine and plasma by UPLC-MS/MS. Urine and plasma samples were extracted and cleaned up by using an immunoaffinity column. A sample of 2.00 mL urine or 1.00 mL of plasma was diluted with 8.00 mL of phosphate buffer solution (PBS) and then loaded onto the immunoaffinity column at a flow rate of 0.5-1.0 mL/min. After washing the column with 10 mL of PBS and 13 mL of water successively, the bound amanitins were eluted with 3.00 mL of methanol-acetone (1∶1, v/v). The eluent was dried under nitrogen at 55 ℃. The residue was dissolved in 100 µL of 10% (v/v) methanol aqueous solution. The amanitins in urine were concentrated 20 times, while those in plasma were concentrated 10 times. Chromatographic separation was performed on a Kinetex Biphenyl column (100 mm × 2.1 mm, 1.7 µm) with gradient elution using methanol and 0.005% (v/v) formic acid aqueous solution as mobile phases. The three amanitins were detected by negative electrospray ionization tandem mass spectrometry in the multiple reaction monitoring (MRM) mode and quantified by the solvent standard curve external standard method. Method validation was performed as recommended by the European Drug Administration (EMEA). Four levels of quality control (QC) samples were prepared, which covered the calibration curve range, viz., the limit of quantification (LOQ), within three times the LOQ (low QC), medium QC, and at 85% of the upper calibration curve range (high QC), and used to test the accuracy, precision, matrix effect, extraction recovery, and stability. The calibration curves for the three amanitins showed good linear relationships in the range of 0.1-200 ng/mL, and the correlation coefficients (r) were greater than 0.999. The matrix effects and extraction efficiencies of the three amanitins in urine and plasma were 92%-108% and 90%-103%, respectively, and the coefficients of variation were less than 13%. The accuracies of the three amanitins in urine were within -9.4%-8.0%. The repeatability and intermediate accuracies were 3.0%-14% and 3.5%-18%, respectively. When the sampling volume was 2.00 mL, the limits of detection of the three amanitins in urine were 0.002 ng/mL. The accuracies of the three amanitins in plasma were within -13%-8.0%. The repeatability and intermediate accuracies were 3.9%-9.7% and 5.5%-12%, respectively. When the sampling volume was 1.00 mL, the limits of detection of the three amanitins in plasma were 0.004 ng/mL. The developed method is simple, sensitive, and accurate. During toxic mushroom poisoning detection, 0.0067 ng/mL of α-amanitin and 0.0059 ng/mL of ß-amanitin were detected in the urine of poisoned patients 138 h after ingesting poisonous mushrooms. This method has successfully solved the problem of detecting ultra-trace levels of amanitins in the urine and plasma of poisoned patients. It has important practical significance for the early diagnosis, early treatment, and mortality reduction of suspected poisoning patients. This method can also provide reliable technical support for future research on the toxicological effects and in vivo metabolism of these toxins.

A Molecular-Sieve Electrolyte Membrane enables Separator-Free Zinc Batteries with Ultralong Cycle Life.

The poor stability of the zinc-metal anode is a main bottleneck for practical application of aqueous zinc-ion batteries. Herein, a series of molecular sieves with various channel sizes are investigated as an electrolyte host to regulate the ionic environment of Zn2+ on the surface of the zinc anode and to realize separator-free batteries. Based on the ZSM-5 molecular sieve, a solid-liquid mixed electrolyte membrane is constructed to uniformize the transport of zinc ions and foster dendrite-free Zn deposition. Side reactions can also be suppressed through tailoring the solvation sheath and restraining the activity of water molecules in electrolyte. A V2 O5 ||ZSM-5||Zn full cell shows significantly enhanced performance compared to cells using glass fiber separator. Specifically, it exhibits a high specific capacity of 300 mAh g-1 , and a capacity retention of 98.67% after 1000 cycles and 82.67% after 3000 cycles at 1 A g-1 . It is attested that zeolites (ZSM-5, H-ß, and Bate) with channel sizes of 5-7 Å result in best cycle stability. Given the low cost and recyclability of the ZSM and its potent function, this work may further lower the cost and boost the industrial application of AZIBs.

Perceived Help-Seeking Difficulty, Barriers, Delay, and Burden in Carers of People with Suspected Dementia.

Because of an often complicated and difficult-to-access care system, help-seeking for people with suspected dementia can be stressful. Difficulty in help-seeking may contribute to carer burden, in addition to other known stressors in dementia care. This study examined the relationship between perceived help-seeking difficulty and carer burden, and the barriers contributing to perceived difficulty. We interviewed 110 carers accessing a community-based dementia assessment service for suspected dementia of a family member for their perceived difficulty, delays, and barriers in help-seeking, and carers burden in terms of role strain, self-criticism, and negative emotions. Linear regression models showed that perceived help-seeking difficulty is associated with carer self-criticism, while carer role strain and negative emotions are associated with symptom severity of the person with dementia but not help-seeking difficulty. Inadequate knowledge about symptoms, service accessibility, and affordability together explained more than half of the variance in perceived help-seeking difficulty (Nagelkerke R2 = 0.56). Public awareness about symptoms, support in navigating service, and financial support may reduce perceived difficulty in help-seeking, which in turn may reduce carer self-criticism during the early course of illness.

Antinociceptive effects of macrophage-derived extracellular vesicles by carrying microRNA-216a.

Cancer-induced bone pain (CIBP) represents the pain induced by bone metastases from malignancies. The role of extracellular vesicles (Evs) has been underscored in bone metastasis. However, the function of Evs, especially these derived from M2 macrophages (M2φ-Evs) in CIBP is unclear. Therefore, this investigation aimed to probe the possible antinociceptive effect of M2φ-Evs in CIBP and the underlying mechanism of action. Using the C57bl/6 mice, a CIBP animal model was established by the administration of Walker 256 mammary gland carcinoma cells, followed by M2φ-Evs administration. It was found that CIBP mice treated with M2φ-Evs had significantly reduced nociception and serum inflammatory factors. Microarray sequencing revealed that microRNA-216a (miR-216a) was the most upregulated miRNA in Evs-treated mouse spinal cord tissues. Subsequent bioinformatics, GSEA and KEGG enrichment analyses demonstrated that HMGB1 and TLR4-NF-κB pathway were the downstream effectors of miR-216a and were both downregulated in spinal cord tissues of CIBP mice treated with M2φ-Evs. Rescue experiments displayed that after we reduced miR-216a expression in M2φ-Evs, the antinociceptive effect of M2φ-Evs on CIBP mice was inhibited, and the HMGB1 expression and the TLR4-NF-κB signaling were significantly activated. Together, M2φ-Evs relieve CIBP by carrying miR-216a, which was elicited through the HMGB1/TLR4-NF-κB axis.

Effectiveness of interventions for people living with dementia and their carers in Chinese communities: protocol for a systematic review and meta-analysis of randomised controlled trials.

INTRODUCTION: As the largest and most rapidly ageing population, Chinese people are now the major driver of the continued growth in dementia prevalence globally. The need for evidence-based interventions in Chinese communities is urgent. Although a wide range of pharmacological and non-pharmacological interventions for dementia have been trialled in Chinese populations, the evidence has not been systematically synthesised. This systematic review and meta-analysis aims to map out the interventions for people living with dementia and their carers in Chinese communities worldwide and compare the effectiveness of these interventions. METHODS AND ANALYSIS: This protocol followed the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols checklist. We will search Chinese (China National Knowledge Infrastructure, WanFang DATA) and English bibliographical databases (MEDLINE, EMBASE, PsycINFO, CINAHL Plus, Global Health, WHO Global Index Medicus, Virtual Health Library, Cochrane CENTRAL, Social Care Online, BASE, MODelling Outcome and cost impacts of interventions for DEMentia (MODEM) Toolkit, Cochrane Database of Systematic Reviews), complemented by hand searching of reference lists. We will include studies evaluating the effectiveness of interventions for dementia or mild cognitive impairment in Chinese populations, using a randomised controlled trial design, and published between January 2008 and June 2020. We will use a standardised form to extract data and Version 2 of the Cochrane risk-of-bias tool for randomised trials to assess the risk of bias of the included studies. Collected data will be fully interpreted with narrative synthesis and analysed using pairwise and network meta-analyses to pool intervention effects where sufficient information is available. We will perform subgroup analysis and meta-regression to explore potential reasons for heterogeneity. ETHICS AND DISSEMINATION: No formal ethics approval is required for this protocol. The findings will facilitate the development of studies on interventions for dementia and timely inform dementia policymaking and practice. Planned dissemination channels include peer-reviewed publications, conference presentations, public events and websites. PROSPERO REGISTRATION NUMBER: CRD42019134135.

[Simultaneous determination of paraquat and diquat in plasma and urine by ion chromatography-triple quadrupole mass spectrometry].

Paraquat (PQ) and diquat (DQ) are widely used as non-selective contact herbicides. Several cases involving accidents, suicide, and homicide by PQ or DQ poisoning have been reported. Poising by PQ, which is mainly concentrated in the lungs, causes acute respiratory distress syndrome and leads to multiple organ toxicity. The toxic effects of DQ are similar to those of PQ but relatively less intense. The mortality rates in PQ and DQ poisoning are high. Simultaneous monitoring of the PQ and DQ concentrations in plasma and urine can provide valuable information for early clinical diagnosis and prognosis. High performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) is the main analytical method used to detect PQ and DQ in plasma and urine. As both these compounds are highly polar and water soluble, they cannot be retained effectively on a reversed-phase column with conventional mobile phases. The separation of PQ and DQ by ion-pair chromatography or hydrophilic chromatography has been reported. The use of an ion-pairing reagent helps in improving the retention capabilities of PQ and DQ. However, the sensitivity of MS detection is noticeably decreased because of ion suppression caused by the ion-pairing reagent in the mobile phase; furthermore, ion-pairing reagents may contaminate the MS system. The separation of PQ and DQ by hydrophilic chromatography is easily affected by matrix components in the sample, and their retention times are not stable. Considering PQ and DQ are bicharged cation species in solution, they are more suitable for separation by cation-exchange chromatography. A method based on ion chromatography-triple quadrupole mass spectrometry was established for the determination of PQ and DQ in plasma and urine. The plasma and urine samples were diluted with water, and then purified on a solid-phase extraction column containing a polymer-reversed phase and weak ion-exchange mixed-mode adsorbent (Oasis WCX). PQ and DQ were separated on an IonPac CS 18 analytical column (250 mm×2.0 mm, 6.0 µm) with gradient elution using a methylsulfonic acid solution electrolytically generated from an on-line eluent generation cartridge. An in-line suppressor was used to remove methylsulfonate and other anions from the eluent before the eluent entered the mass spectrometer. Between the suppressor and the ion source in MS, the addition of 3% (v/v) formic acid in acetonitrile as an organic modifier (using an auxiliary pump and a T-piece) aided desolvation in the ion source, resulted in a one-or two-fold improvement of the response, and eliminated the residual effects of the adsorption of PQ and DQ caused by ion source. The analytes were detected by triple quadrupole tandem mass spectrometry using positive electrospray ionization in the multiple reaction monitoring (MRM) mode. PQ-d8 and DQ-d4 were used as internal standards. The calibration curves for PQ and DQ showed good linear relationships in the ranges of 1.0-150 µg/L and 0.5-75 µg/L, respectively, and the correlation coefficients were > 0.999. The average matrix effects of PQ and DQ in plasma were 84.2%-89.3% and 84.7%-91.1%, while the average matrix effects of PQ and DQ in urine were 50.3%-58.4% and 51.9%-59.4%. The average recoveries of PQ and DQ in plasma were 93.5%-117% and 91.7%-112%, respectively, with relative standard deviations (RSDs) of 3.4-16.7% and 2.8%-13.2%, and that in urine were 90.0%-118% and 99.2%-116%, with relative standard deviations of 5.6%-14.9% and 2.4%-17.3% (n=6). The limits of detection of PQ and DQ in plasma and urine were 0.3 µg/L and 0.2 µg/L, respectively, with the corresponding limits of quantification being 1.0 µg/L and 0.5 µg/L. This method is sensitive and accurate, and it can be used to determine PQ and DQ for clinical diagnosis and prognosis in patients.

[Simultaneous determination of cucurbitacin B, E and I in plasma, urine, and melon and fruit vegetables by ultra performance liquid chromatography-triple quadrupole mass spectrometry using atmospheric pressure chemical ionization].

A method for the determination of cucurbitacin B (CuB), cucurbitacin I (CuI) and cucurbitacin E (CuE) in plasma, urine and melon and fruit vegetables was developed by ultra performance liquid chromatography-triple quadrupole mass spectrometry (UPLC-MS/MS). The target analytes in plasma and urine were extracted and cleaned-up by solid supported liquid-liquid extraction, while those in melon and fruit vegetables were extracted with acetonitrile and then diluted with water. CuB, CuI and CuE were separated on an XBridge BEH C18 column (100 mm×3.0 mm, 2.5 µm) with gradient elution using mobile phases of methanol and 0.025% (v/v) ammonia aqueous solution. An atmospheric pressure chemical ionization interface was used as the ion source and the analysis was performed in negative ionization multiple reaction monitoring (MRM) mode. The cucurbitacins in plasma and urine were quantified by the matrix working standard curve internal standard method, while those in melon and fruit vegetables were quantified by the solvent standard curve external standard method. Oleandrin was used as the internal standard. The average recoveries were 89.0%-113% for the three cucurbitacins in plasma and urine, with RSDs of 1.7%-12.2% (n=6). The average recoveries were 87.6%-114% for the three cucurbitacins in melon and fruit vegetables, with RSDs of 4.1%-11.1% (n=6). The limit of detection (S/N=3) of the three cucurbitacins was 0.03 µg/L in plasma and urine, and 5-10 µg/kg in melon and fruit vegetables. The method is simple, sensitive and accurate. It has been used for the determination of cucurbitacins in bitter bottle gourd and in the plasma and urine of patients poisoned by bitter bottle gourd, CuB was successfully detected.

[Determination of coriatin and corianin in plasma and urine using ultra-performance liquid chromatography-triple quadrupole mass spectrometry].

An ultra-performance liquid chromatography-triple quadrupole mass spectrometry (UPLC-MS/MS) method has been developed for the determination of coriatin and corianin in plasma and urine, which are the biomarkers of poisoning caused by Coriaria sinica Maxim. Plasma and urine samples were extracted and purified using a solid supported liquid/liquid extraction method. Chromatographic separation was performed on a Cortecs C18 column (100 mm×2.1 mm, 1.6 µm) using a gradient elution of methanol and water. Coriatin and corianin were detected using negative electrospray ionization tandem mass spectrometry in multiple reaction monitoring (MRM) mode and quantified via a matrix working standard curve internal standard method; florfenicol was used as the internal standard. The assay was linear in the calibration range of 0.03-5.0 µg/L for coriatin and 0.3-50 µg/L for corianin in plasma, and 0.1-10 µg/L and 1-100 µg/L for coriatin and corianin in urine, respectively. The average recoveries were 86.2%-110% for coriatin and corianin in plasma and urine with relative standard deviations of 5.1%-14.6% (n=6). The limits of detection (S/N=3) for coriatin and corianin were 0.01 µg/L and 0.1 µg/L in plasma, and 0.03 µg/L and 0.3 µg/L in urine, respectively. The method is simple, sensitive and accurate for the determination of coriatin and corianin in plasma and urine for toxicological purposes.

[Simultaneous rapid determination of 84 toxic plant constituents in plasma and urine by ultra-performance liquid chromatography- triple quadrupole/linear ion trap mass spectrometry].

An ultra-performance liquid chromatography-triple quadrupole/linear ion trap mass spectrometry (UPLC-Qtrap MS) method was developed for the determination of 84 toxic plant constiuents in plasma and urine. Plasma was precipitated by acetonitrile to remove proteins and then passed through a Prime HLB SPE column to remove phospholipids, while urine was diluted with methanol. Chromatographic separation of the analytes was achieved on an Acquity BEH C18 column (100 mm×2.1 mm, 1.7 µm) by gradient elution using the mobile phase of 0.1% (v/v) formic acid and 2 mmol/L ammonium formate both in 97% (v/v) acetonitrile aqueous solution and water. Electrospray ionization mass spectrometry was carried out in the positive ion mode with multiple reaction monitoring-information dependent acquisition-enhanced product ion scan mode (MRM-IDA-EPI). The 84 analytes were quantified by the matrix working standard curve internal standard method, and a good linear relationship was observed, with correlation coefficients of ≥ 0.9911. The limits of detection (LODs) in plasma and urine were 0.01-1 µg/L and 0.03-2 µg/L, respectively. The intra- and inter-day precisions of these analytes were 0.7%-18.4% and 1.1%-18.5%, and the accuracy of all analytes ranged from 70.6% to 124.5%. This method is simple, sensitive, and accurate for the measurement of these analytes in plasma and urine for both clinical and forensic applications.