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Analytical Sciences : the International... Dec 2023Azo-linked covalent organic polymers (ACOPs) were synthesized by a simple azo reaction, with 2,2'-bis(trifluoromethyl)benzidine and 1,3,5-trihydroxybenzene as the...
Azo-linked covalent organic polymers (ACOPs) were synthesized by a simple azo reaction, with 2,2'-bis(trifluoromethyl)benzidine and 1,3,5-trihydroxybenzene as the monomers. The preparation process was mild, green, and environmental-friendly, avoiding the use of high temperature, metal catalysis, and harmful organic reagent. The obtained ACOPs were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, powder X-ray diffraction, and Brunauer-Emmett-Teller. With the prepared ACOPs as adsorbent, a method of pipette tip solid-phase extraction-liquid chromatography-tandem mass spectrometry detection (PTSPE-LC-MS/MS) was proposed for the analysis of target sedatives in animal tissues. Furthermore, the parameters for the extraction of five sedatives, including the amount of adsorbent, pH value, ion strength, elution solvent and volume, were investigated. Under the optimized conditions, the linear dynamic range was found from 0.1 to 10.0 μg kg, and the limits of detection were ranged from 0.02 to 0.1 μg kg. The method was assessed by the analysis of target sedatives in animal tissues, and the recoveries for the spiked pork muscle and pork liver samples were 84-102% and 83-101%, respectively. The results show that the developed method of PTSPE-LC-MS/MS with ACOPs as adsorbent is efficient for the analysis of trace sedatives in animal tissues.
Topics: Animals; Polymers; Chromatography, Liquid; Tandem Mass Spectrometry; Adsorption; Solid Phase Extraction; Chromatography, High Pressure Liquid
PubMed: 37584814
DOI: 10.1007/s44211-023-00406-5 -
Journal of Chromatography. A Jul 2024A novel azo-linked porous organic polymer (AL-POP) was synthesized from caffeic acid and benzidine via an azo-coupling reaction and characterized by FTIR, SEM-EDS, BET,...
Melamine sponges incorporated azo-linked porous organic polymer as adsorbent for extraction and determination of six B vitamins using pipette tip micro solid-phase extraction.
A novel azo-linked porous organic polymer (AL-POP) was synthesized from caffeic acid and benzidine via an azo-coupling reaction and characterized by FTIR, SEM-EDS, BET, TGA, XRD and zeta potential analysis. AL-POPs were incorporated into melamine sponges and used for pipette tip micro solid-phase extraction (PT-MSPE) of six types of B vitamins (including thiamine, riboflavin, nicotinamide, pyridoxine, folic acid, and cyanocobalamin). After extraction, the samples were analyzed using high performance liquid chromatography-diode array detection (HPLC-DAD) system. The effect of AL-POP composition on the extraction efficiency (EE) of vitamins was investigated and benzidine to caffeic acid mol ratio of 1.5, 3.35 mmol of NaNO and reaction time of 8 h were selected as optimum conditions. The efficiency of the extraction process was improved by optimizing various parameters such as the amount of sorbent, pH and ionic strength of the sample, sample volume, number of sorption and desorption cycles, type of wash solvent, and type and volume of eluent solvent. Linearity (R≥0.9987), Limit of detection (LOD) (11.88-18.97 ng/mL), limit of quantification (LOQ) (39.62-63.23 ng/mL), and enrichment factor (EF) (1.27-4.31) were obtained using calibration curves plotted under optimum conditions. Recovery values of these six B vitamins in the spiked multivitamin syrup samples varied from 80.01% to 108.35%, with a relative standard deviation (RSD) below 5.44%. Eventually, the optimized method was successfully used to extract and quantify the B vitamins in multivitamin syrup and non-alcoholic beer.
Topics: Triazines; Limit of Detection; Porosity; Chromatography, High Pressure Liquid; Vitamin B Complex; Adsorption; Polymers; Azo Compounds; Solid Phase Microextraction; Solid Phase Extraction; Hydrogen-Ion Concentration
PubMed: 38788401
DOI: 10.1016/j.chroma.2024.464978 -
Journal of Chromatography. A Nov 2023Simultaneous determination of multiple biomarkers can improve the effectiveness and accuracy of cancer diagnosis. Cortisol, cortisone, and 4-methoxyphenylacetic acid...
Simultaneous determination of three biomarkers of non-small cells lung cancer in urine by pipette-tip solid-phase extraction coupled with liquid chromatography tandem mass spectrometry.
Simultaneous determination of multiple biomarkers can improve the effectiveness and accuracy of cancer diagnosis. Cortisol, cortisone, and 4-methoxyphenylacetic acid (4-Me) are metabolic biomarker group with high specificity and sensitivity for the diagnosis of non-small cells lung cancer (NSCLC), and the development of their simultaneous determination method is desired. Herein, a simple, sensitive, and low-cost method involving pipette-tip solid-phase extraction (PT-SPE) using anion exchange adsorbent (MAX) coupled with liquid chromatography tandem mass spectrometry (LC-MS/MS) was developed for the simultaneous determination of three biomarkers (cortisol, cortisone, and 4-Me) in human urine. The sample (0.1 mL), adsorbent (1.5 mg) and organic reagent (3.5 mL) of MAX-PT-SPE are less consumed, and have the advantages of easy access to raw materials, simple assembly, convenient on-site instant extraction, low pollution, and low cost. The limits of detection of the three biomarkers were 0.006-0.024 ng mL, the recoveries of three spiked levels (2, 50, and 500 ng mL) were 91.0%-99.3%, with the relative standard deviations (RSDs) ≤ 5.9%. Finally, the MAX-PT-SPE-LC-MS/MS method achieved the quantitative analysis of cortisol, cortisone, and 4-Me in urine of different patients of NSCLC. This method is expected to be used in the non-invasive auxiliary diagnosis of NSCLC, and it provides a new strategy for multi-molecular diagnosis and multi-omics combined diagnosis.
Topics: Humans; Chromatography, Liquid; Tandem Mass Spectrometry; Cortisone; Hydrocortisone; Lung Neoplasms; Solid Phase Extraction; Chromatography, High Pressure Liquid
PubMed: 37852047
DOI: 10.1016/j.chroma.2023.464448 -
PloS One 2023Plate-based proteomic sample preparation offers a solution to the large sample throughput demands in the biotechnology field where hundreds or thousands of engineered...
Plate-based proteomic sample preparation offers a solution to the large sample throughput demands in the biotechnology field where hundreds or thousands of engineered microbes are constructed for testing is routine. Meanwhile, sample preparation methods that work efficiently on broader microbial groups are desirable for new applications of proteomics in other fields, such as microbial communities. Here, we detail a step-by-step protocol that consists of cell lysis in an alkaline chemical buffer (NaOH/SDS) followed by protein precipitation with high-ionic strength acetone in 96-well format. The protocol works for a broad range of microbes (e.g., Gram-negative bacteria, Gram-positive bacteria, non-filamentous fungi) and the resulting proteins are ready for tryptic digestion for bottom-up quantitative proteomic analysis without the need for desalting column cleanup. The yield of protein using this protocol increases linearly with respect to the amount of starting biomass from 0.5-2.0 OD*mL of cells. By using a bench-top automated liquid dispenser, a cost-effective and environmentally-friendly option to eliminating pipette tips and reducing reagent waste, the protocol takes approximately 30 minutes to extract protein from 96 samples. Tests on mock mixtures showed expected results that the biomass composition structure is in close agreement with the experimental design. Lastly, we applied the protocol for the composition analysis of a synthetic community of environmental isolates grown on two different media. This protocol has been developed to facilitate rapid, low-variance sample preparation of hundreds of samples and allow flexibility for future protocol development.
Topics: Acetone; Proteomics; Proteins; Indicators and Reagents
PubMed: 37418444
DOI: 10.1371/journal.pone.0288102 -
Angewandte Chemie (International Ed. in... May 2024Capturing short-lived intermediates at the molecular level is key to understanding the mechanism and dynamics of chemical reactions. Here, we have developed a...
Capturing short-lived intermediates at the molecular level is key to understanding the mechanism and dynamics of chemical reactions. Here, we have developed a paper-in-tip bipolar electrolytic electrospray mass spectrometry platform, in which a piece of triangular conductive paper incorporated into a plastic pipette tip serves not only as an electrospray emitter but also as a bipolar electrode (BPE), thus triggering both electrospray and electrolysis simultaneously upon application of a high voltage. The bipolar electrolysis induces a pair of redox reactions on both sides of BPE, enabling both electro-oxidation and electro-reduction processes regardless of the positive or negative ion mode, thus facilitating access to complementary structural information for mechanism elucidation. Our method enables real-time monitoring of transient intermediates (such as N,N-dimethylaniline radical cation, dopamine o-quinone (DAQ) and sulfenic acid with half-lives ranging from microseconds to minutes) and transient processes (such as DAQ cyclization with a rate constant of 0.15 s). This platform also provides key insights into electrocatalytic reactions such as Fe (III)-catalyzed dopamine oxidation to quinone species at physiological pH for neuromelanin formation.
PubMed: 38717236
DOI: 10.1002/anie.202318169 -
BMC Women's Health Apr 2024Women presenting with abnormal uterine bleeding needs careful and thorough assessment including ultrasound examination of endometrium and histopathological assessment of...
Rate and risk factors of inadequate endometrial tissues after endometrial sampling among Bhutanese women at the national referral hospital of Bhutan: a cross-sectional study.
INTRODUCTION
Women presenting with abnormal uterine bleeding needs careful and thorough assessment including ultrasound examination of endometrium and histopathological assessment of the endometrial tissues. The objective of this cross-sectional study was to determine the rate and the factors associated with inadequate endometrial tissues after endometrial sampling using MedGyn® pipette among Bhutanese women at the colposcopy clinic, Jigme Dorji Wangchuck National Referral Hospital (JDWNRH), Bhutan.
METHODS
This cross-sectional study was conducted at the colposcopy clinic, JDWNRH, Thimphu between October, 2021 and March, 2022. Women included in this study underwent endometrial sampling using MedGyn® pipette without anesthesia as an office procedure. Data were collected using an interviewer-administered questionnaire and results extracted into a structured pro forma. The histopathology reports were extracted from the Department of Pathology and Laboratory Medicine, JDWNRH using the unique Bhutanese citizenship identity card number of the study participants.
RESULTS
Inadequate endometrial tissues were noted in 27% (33 out of 122 cases). Among 89 patients with an adequate endometrial tissue, histologic results were normal in 30 (33.7%), benign pathology in 22 (24.7%), atrophy in 10 (8.2%), and hyperplasia in 27 (30.3%). In a univariate analysis, menopausal state (OR 1.6, 95% CI 0.708-3.765), overweight and obese (OR 1.6 95% CI 0.640-3.945), unemployed (OR 1.7, 95% CI 0.674-1.140), nulliparous (OR 1.7, 95% CI 0.183-15.816), primipara (OR 5.1, 95% CI 0.635-40.905) and use of hormonal contraception (OR 2.1, 95% CI 0.449-10.049) were associated with increased risk of inadequate endometrial tissues. On multivariate regression analysis, nulliparity (OR 1.1, 95% CI 0.101-12.061), overweight and obesity (OR 1.4, 95% CI 0.490-3.917), use of hormonal contraceptives (OR 2.2, 95% CI 0.347-13.889), and junior surgeons (OR 1.1, 95%CI 0.463-2.443) were found to be associated with inadequate endometrial tissues. However, the above associations were not statistically significant (p > 0.05).
CONCLUSION
The rate of inadequate endometrial tissue following endometrial sampling using MedGyn® pipette was 27.0%. Factors associated with an increased risk of inadequate endometrial tissue after endometrial sampling were menopausal state, overweight and obese, unemployed, nulliparous, primipara and use of hormonal contraception.
Topics: Humans; Female; Bhutan; Cross-Sectional Studies; Overweight; Endometrium; Obesity; Risk Factors; Referral and Consultation; Uterine Hemorrhage; Endometrial Neoplasms
PubMed: 38566186
DOI: 10.1186/s12905-024-03047-6 -
Journal of Labelled Compounds &... Mar 2024While automated modules for F-18 and C-11 radiosyntheses are standardized with features such as multiple reactors, vacuum connection and semi-preparative HPLC, labeling...
While automated modules for F-18 and C-11 radiosyntheses are standardized with features such as multiple reactors, vacuum connection and semi-preparative HPLC, labeling and processing of compounds with radiometals such as Zr-89, Lu-177 and Ac-225 often do not require complex manipulations and are frequently performed manually by a radiochemist. These procedures typically involve transferring solutions to and from vials using pipettes followed by heating of the reaction mixture, and do not require all the features found in most commercial automated synthesis units marketed as F-18 or C-11 modules. Here we present an efficient automated method for performing radiosyntheses involving radiometals by adapting a commercially available robotic pipettor originally developed for high-throughput processing of biological samples. While a robotic pipettor is less costly than a radiosynthesis module, it holds many similar advantages over manual radiosynthesis such as minimization of operator error, lower operator exposure rates, and abbreviated synthesis times, among others. To demonstrate the feasibility of using the OpenTrons OT-2 robotic pipettor to perform automated radiosyntheses, we radiolabeled and formulated Lu-PSMA-617 and Ac-PSMA-617 on the system. The OT-2 was then used to help streamline the quality control process for both products, further minimizing manual handling by and exposure to the radiochemist.
Topics: Radioisotopes; Actinium; Zirconium; Robotic Surgical Procedures; Dipeptides; Heterocyclic Compounds, 1-Ring; Prostate-Specific Antigen
PubMed: 38296817
DOI: 10.1002/jlcr.4085 -
The Journal of Biological Chemistry Apr 2024Mechanically activated Piezo1 channels undergo transitions from closed to open-state in response to pressure and other mechanical stimuli. However, the molecular details...
Mechanically activated Piezo1 channels undergo transitions from closed to open-state in response to pressure and other mechanical stimuli. However, the molecular details of these mechanosensitive gating transitions are unknown. Here, we used cell-attached pressure-clamp recordings to acquire single channel data at steady-state conditions (where inactivation has settled down), at various pressures and voltages. Importantly, we identify and analyze subconductance states of the channel which were not reported before. Pressure-dependent activation of Piezo1 increases the occupancy of open and subconductance state at the expense of decreased occupancy of shut-states. No significant change in the mean open time of subconductance states was observed with increasing negative pipette pressure or with varying voltages (ranging from -40 to -100 mV). Using Markov-chain modeling, we identified a minimal four-states kinetic scheme, which recapitulates essential characteristics of the single channel data, including that of the subconductance level. This study advances our understanding of Piezo1-gating mechanism in response to discrete stimuli (such as pressure and voltage) and paves the path to develop cellular and tissue level models to predict Piezo1 function in various cell types.
Topics: Humans; HEK293 Cells; Ion Channel Gating; Ion Channels; Kinetics; Markov Chains; Mechanotransduction, Cellular; Pressure
PubMed: 38479601
DOI: 10.1016/j.jbc.2024.107156 -
Mikrochimica Acta Nov 2023Microfluidic cotton thread-based electroanalytical devices (μTEDs) are analytical systems with attractive features such as spontaneous passive flow, low cost, minimal...
Improving the performance and versatility of microfluidic thread electroanalytical devices by automated injection with electronic pipettes: a new and powerful 3D-printed analytical platform.
Microfluidic cotton thread-based electroanalytical devices (μTEDs) are analytical systems with attractive features such as spontaneous passive flow, low cost, minimal waste production, and good sensitivity. Currently, sample injection in µTEDs is performed by hand using manual micropipettes, which have drawbacks such as inconstant speed and position, dependence of skilled analysts, and need of physical effort of operator during prolonged times, leading to poor reproducibility and risk of strain injury. As an alternative to these inconveniences, we propose, for the first time, the use of electronic micropipettes to carry out automated injections in µTEDs. This new approach avoids all disadvantages of manual injections, while also improving the performance, experience, and versatility of µTEDs. The platform developed here is composed by three 3D-printed electrodes (detector) attached to a 3D-printed platform containing an adjustable holder that keeps the electronic pipette in the same x/y/z position. As a proof-of-concept, both injection modes (manual and electronic) were compared using three model analytes (nitrite, paracetamol, and 5-hydroxytryptophan) on µTED with amperometric detection. As result, improved analytical performance (limits of detection between 2.5- and 5-fold lower) was obtained when using electronic injections, as well as better repeatability/reproducibility and higher analytical frequencies. In addition, the determination of paracetamol in urine samples suggested better precision and accuracy for automated injection. Thus, electronic injection is a great advance and changes the state-of-art of µTEDs, mainly considering the use of more modern and versatile electronic pipettes (wider range of pre-programmed modes), which can lead to the development of even more automated systems.
PubMed: 37926729
DOI: 10.1007/s00604-023-06026-0 -
Journal of Chromatography. A Jan 2024Alectinib is known as an effective targeted drug, which has excellent therapeutic effect on non-small cell lung cancer and can significantly prolong the survival of...
Determination of alectinib and its active metabolite in plasma by pipette-tip solid-phase extraction using porous polydopamine graphene oxide adsorbent coupled with high-performance liquid chromatography-ultraviolet detection.
Alectinib is known as an effective targeted drug, which has excellent therapeutic effect on non-small cell lung cancer and can significantly prolong the survival of patients. Therapeutic drug monitoring is necessary due to the photo-instability of alectinib and the individual differences in patients. In this work, a porous polydopamine graphene oxide composite (PDAG) was prepared by a simple surface modification method. A PDAG-based pipette-tip solid-phase extraction (PT-SPE) coupled with HPLC-UV detection was proposed for the separation and detection of alectinib and its active metabolite M4 in plasma. The method was methodologically validated and showed good linearity in the range of 50-5000 ng mL (R > 0.9995). The limit of detection (LOD) was 4.8 ng mL and 3.9 ng mL for alectinib and M4, respectively, and the limit of quantitation (LOQ) was 16.1 ng mL and 13.1 ng mL, respectively. The intra-day and inter-day precision expressed by coefficient of variation was less than 4.8 %. The recovery of this method ranged from 84.9 % to 103.5 % with a standard deviation of less than 4.3 %. In conclusion, the established method is accurate, stable and inexpensive, and can be used to monitor the levels of alectinib and M4 in plasma, which provide technical and data support for exploring optimal individualized remedial dosing regimens.
Topics: Humans; Chromatography, High Pressure Liquid; Porosity; Carcinoma, Non-Small-Cell Lung; Lung Neoplasms; Solid Phase Extraction
PubMed: 38104506
DOI: 10.1016/j.chroma.2023.464578