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1.
BMC Nurs ; 23(1): 389, 2024 Jun 06.
Article in English | MEDLINE | ID: mdl-38844927

ABSTRACT

BACKGROUND: Existing researches on nurses' work engagement and job burnout have mostly stayed at the individual level, and limited researches test the cross-level effects of psychosocial safety climate (PSC). The study aimed to explore the cross-level mediating effect of organization-based self-esteem (OBSE) and the moderating effect of psychological detachment between the relationship of PSC and work engagement and job burnout in nurses. METHODS: The cross-sectional study was conducted during November to December 2022 at a tertiary hospital in a northeastern province of China. Data was collected from 1832 nurses through an online questionnaire. Correlation analyses and hierarchical linear modeling were used to test study hypotheses. RESULTS: The results showed that PSC was positively associated with work engagement, and negatively associated with job burnout. OBSE mediated the effect of PSC on work engagement, as well as job burnout. Additionally, psychological detachment played a moderating role between PSC and work engagement, but no moderating effect was found between PSC and job burnout. CONCLUSIONS: PSC at the organizational level increases work engagement and reduces job burnout by stimulating nurses' high levels of OBSE. Psychological detachment, as a situational factor, enhances the positive influence of PSC on work engagement. The implementation of measures to improve the PSC levels of the organization, and the levels of OBSE and psychological detachment among nurses could help to promote their good work performance.

2.
Anal Chem ; 96(18): 7187-7193, 2024 May 07.
Article in English | MEDLINE | ID: mdl-38671557

ABSTRACT

Despite the significant importance of blood lithium (Li) detection in the treatment of bipolar disorder (BD), its point-of-care testing (POCT) remains a great challenge due to tedious sample preparation and the use of large-footprint atomic spectrometers. Herein, a system coupling dried blood spots (DBS) with a point discharge optical emission spectrometer equipped with a miniaturized ultrasonic nebulizer (MUN-µPD-OES) was developed for POCT of blood Li. Three microliters of whole blood were used to prepare a dried blood spot on a piece of filter paper to which 10 µL of eluent (1% (v/v) formic acid and 0.05% (v/v) Triton-X) was added. Subsequently, the paper was placed onto the vibrating steel membrane of the ultrasonic nebulizer and powered on to generate aerosol. The aerosol was directly introduced to the µPD-OES for quantification of Li by monitoring its atomic emission line at 670.8 nm. The proposed method minimized matrix interference caused by high levels of salts and protein. It is worth noting that the MUN suitably matches the needs of DBS sampling and can provide aerosolized introduction of Li into the assembled µPD-OES, thus eliminating all tedious sample preparation and the need for a commercial atomic spectrometer. Calibration response is linear in the therapeutic range and a limit of detection (LOD) of 1.3 µg L-1 is well below the Li minimum therapeutic concentration (2800 µg L-1). Li in mouse blood was successfully detected in real-time using MUN-µPD-OES after intraperitoneal injection of lithium carbonate, confirming that the system holds great potential for POCT of blood Li for patients with BD.


Subject(s)
Dried Blood Spot Testing , Lithium , Point-of-Care Testing , Lithium/blood , Humans , Dried Blood Spot Testing/instrumentation , Dried Blood Spot Testing/methods , Animals , Mice , Nebulizers and Vaporizers , Miniaturization , Ultrasonics , Limit of Detection
3.
Chem Commun (Camb) ; 60(39): 5205-5208, 2024 May 09.
Article in English | MEDLINE | ID: mdl-38652014

ABSTRACT

This work developed an aptamer-dye complex as a label-free ratiometric fluorescence sensor for rapid analysis of THC and its metabolite in sewage samples. Integrated with a portable fluorescence capture device, this sensor exhibited excellent sensitivity with visualization of as low as 0.6 µM THC via naked-eye observation, and THC analysis can be accomplished within 4 min, which would be a complementary tool for quantifying THC in sewage samples to estimate cannabis consumption.


Subject(s)
Aptamers, Nucleotide , Dronabinol , Fluorescent Dyes , Sewage , Aptamers, Nucleotide/chemistry , Dronabinol/analysis , Dronabinol/chemistry , Fluorescent Dyes/chemistry , Sewage/analysis , Sewage/chemistry , Spectrometry, Fluorescence , Biosensing Techniques
4.
J Hazard Mater ; 470: 134038, 2024 May 15.
Article in English | MEDLINE | ID: mdl-38552392

ABSTRACT

Millions of people worldwide are affected by naturally occurring arsenic in groundwater. The development of a low-cost, highly sensitive, portable assay for rapid field detection of arsenic in water is important to identify areas for safe wells and to help prioritize testing. Herein, a novel paper-based fluorescence assay was developed for the on-site analysis of arsenic, which was constructed by the solid-phase fluorescence filter effect (SPFFE) of AsH3-induced the generation of silver nanoparticles (AgNPs) toward carbon dots. The proposed SPFFE-based assay achieves a low arsenic detection limit of 0.36 µg/L due to the efficient reduction of Ag+ by AsH3 and the high molar extinction coefficient of AgNPs. In conjunction with a smartphone and an integrated sample processing and sensing platform, field-sensitive detection of arsenic could be achieved. The accuracy of the portable assay was validated by successfully analyzing surface and groundwater samples, with no significant difference from the results obtained through mass spectrometry. Compared to other methods for arsenic analysis, this developed system offers excellent sensitivity, portability, and low cost. It holds promising potential for on-site analysis of arsenic in groundwater to identify safe well locations and quickly obtain output from the global map of groundwater arsenic.

5.
Anal Chem ; 96(11): 4665-4672, 2024 Mar 19.
Article in English | MEDLINE | ID: mdl-38456411

ABSTRACT

Detecting scandium (Sc) with high selectivity and sensitivity is a challenging task due to its chemical similarity to other rare earth ions. Our findings show that the fluorescence of the complex fluorescent indicator calcein (CL) is quenched under acidic conditions (pH = 2), and Sc3+ strongly inhibits this process. The results demonstrate that CL forms multimers and precipitates out of the solution under acidic conditions, while Sc3+ causes a significant decrease in the scattering intensity of the solution. Additional experiments revealed that the strong Lewis acid nature of Sc3+ complexes with the carboxyl groups of CL leads to increased dispersion of CL even under acidic conditions, thus enhancing its absorption and fluorescence. The complexation ratio of Sc3+ and CL was investigated through spectral titrations and theoretical calculations. The interaction between Sc3+ and CL is the strongest among rare earth and common metal ions due to the smallest ionic radius, resulting in high selectivity. The fluorescence turn-on strategy had a linear range of 0.04 to 2.25 µM under optimal conditions, with a detection limit of 20 nM for Sc3+. The combination of 3D printing and a smartphone program allows for portable on-site analysis of Sc3+. Mineral and water samples were used to demonstrate the potential of this strategy for the rapid, selective, and sensitive analysis of low levels of Sc3+.

6.
Anal Chem ; 96(13): 5170-5177, 2024 Apr 02.
Article in English | MEDLINE | ID: mdl-38512240

ABSTRACT

To meet the needs of food safety for simple, rapid, and low-cost analytical methods, a portable device based on a point discharge microplasma optical emission spectrometer (µPD-OES) was combined with machine learning to enable on-site food freshness evaluation and detection of adulteration. The device was integrated with two modular injection units (i.e., headspace solid-phase microextraction and headspace purge) for the examination of various samples. Aromas from meat and coffee were first introduced to the portable device. The aroma molecules were excited to specific atomic and molecular fragments at excited states by room temperature and atmospheric pressure microplasma due to their different atoms and molecular structures. Subsequently, different aromatic molecules obtained their own specific molecular and atomic emission spectra. With the help of machine learning, the portable device was successfully applied to the assessment of meat freshness with accuracies of 96.0, 98.7, and 94.7% for beef, pork, and chicken meat, respectively, through optical emission patterns of the aroma at different storage times. Furthermore, the developed procedures can identify beef samples containing different amounts of duck meat with an accuracy of 99.5% and classify two coffee species without errors, demonstrating the great potential of their application in the discrimination of food adulteration. The combination of machine learning and µPD-OES provides a simple, portable, and cost-effective strategy for food aroma analysis, potentially addressing field monitoring of food safety.


Subject(s)
Coffee , Food Safety , Animals , Cattle , Meat/analysis , Food Contamination/analysis , Food Analysis
7.
Talanta ; 272: 125833, 2024 May 15.
Article in English | MEDLINE | ID: mdl-38430867

ABSTRACT

Iodine is essential for human growth and can enter the body through food, water, and air. Analyzing its presence in the environment is crucial for ensuring healthy human development. However, current large-scale instruments have limitations in the field analysis of iodine. Herein, a miniaturized purge and trap point discharge microplasma optical emission spectrometric (P&T-µPD-OES) device was developed for the field analysis of iodine in water. Volatile iodine molecules were produced from total inorganic iodine (TII) through a basic redox reaction under acidic conditions, then the purge and trap module effectively separated and preconcentrated iodine molecules. The iodine molecules were subsequently atomized and excited by the integrated point discharge microplasma and an iodine atomic emission line at 206.24 nm was monitored by the spectrometer. Under optimal conditions, this proposed method had a detection limit of 16.2 µg L-1 for iodine and a precision better than 4.8%. Besides, the accuracy of the portable device was validated by successful analysis of surface and groundwater samples and a comparison of the mass spectrometry method. This proposed portable, low-power device is expected to support rapid access to iodine levels and distribution in water.

8.
Environ Sci Technol ; 58(5): 2554-2563, 2024 Feb 06.
Article in English | MEDLINE | ID: mdl-38266240

ABSTRACT

Rapid and in situ identification of specific polymers is a challenging and crucial step in plastic recycling. However, conventional techniques continue to exhibit significant limitations in the rapid and field classification of plastic products, especially with the wide range of commercially available color polymers because of their large size, high energy consumption, and slow and complicated analysis procedures. In this work, a simple analytical system integrating a miniature and low power consumption (22.3 W) pyrolyzer (Pyr) and a low temperature, atmospheric pressure point discharge optical emission spectrometer (µPD-OES) was fabricated for rapidly identifying polymer types. Plastic debris is decomposed in the portable pyrolyzer to yield volatile products, which are then swept into the µPD-OES instrument for monitoring the optical emission patterns of the thermal pyrolysis products. With machine learning, five extensively used raw polymers and their consumer plastics were classified with an accuracy of ≥97.8%. Furthermore, the proposed method was applied to the identification of the aged polymers and plastic samples collected from a garbage recycling station, indicating its great potential for identification of environmentally weathered plastics. This portable Pyr-µPD-OES system provides a cost-effective tool for rapid and field identification of polymer types of recycled plastic for proper management and resource recycling.


Subject(s)
Plastics , Pyrolysis , Plastics/analysis , Polymers , Recycling , Machine Learning
9.
Anal Chem ; 95(47): 17238-17245, 2023 Nov 28.
Article in English | MEDLINE | ID: mdl-37966796

ABSTRACT

Acid-base titration of complex samples is conducive to the rapid evaluation of the degree and risk of environmental pollution to some extent. However, the traditional titration methods usually suffer from serious interference. Herein, an automatic acid-base titration method coupling miniature point discharge optical emission spectrometry (µPD-OES) with CO2 vapor generation was described for the precise, sensitive, and matrix interference-free acid-base titration of complex samples, particularly those with high color intensity, salinity, and turbidity such as wastewater and soil samples. In this work, acid-base titration was carried out in a chemical vapor generator where CO2 was generated through the addition of HCl or NaHCO3, thus enabling efficient separation of CO2 from a complex matrix. The generated CO2 was subsequently swept into the miniaturized point discharge for excitation and further detection by µPD-OES, where the carbon atomic emission at 193.0 nm was monitored. According to the consumed volume and concentration of HCl, accurate and automatic measurements of OH-, CO32-, and HCO3- can be accomplished. The proposed method possesses a high sensitivity of µPD-OES for the detection of CO2 with a relative standard deviation of below 3.0%. Moreover, the proposed system not only retains several unique advantages of accuracy, simplicity, and elimination of the use of complicated, expensive, and high power-consumption instruments but also alleviates the color and turbid interference from complex samples such as dyeing wastewater samples, oilfield water samples, and soil samples. It retains a promising potential application for titration analysis of other samples such as sludge, sediment, and landfill leachate.

10.
Anal Chem ; 95(49): 18303-18308, 2023 12 12.
Article in English | MEDLINE | ID: mdl-38019658

ABSTRACT

Salivary pepsin has been proposed as a promising diagnostic marker for gastroesophageal reflux disease (GERD). However, the activity of human pepsin is strongly influenced by pH, and the acidic condition (pH ∼ 2) is optimal, which is a contradiction for the pepsin detection kit based on its catalytic activity. Thus, its accurate quantification in saliva (neutral pH) by readily rapid tools with simplicity and low cost is still challenging. Herein, a convenient fluorescence assay has been developed for the rapid detection of pepsin at neutral pH based on its electrostatic interaction with SYBR Green (SG) rather than the bioactivity. At neutral pH, the positively charged SG fluorophore can be effectively adsorbed by the negatively charged pepsin due to the low isoelectric point (pI) and large molecular size of pepsin. Thus, the molecular rotation of SG is limited, and its fluorescence intensity is significantly increased. The strategy was further confirmed to have the same fluorescence response as that of normally active and inactivated pepsin. Due to the unique pI of pepsin, the fluorescence strategy is highly selective for pepsin compared to other proteins. On the basis of this strategy, a smartphone-based fluorescence capture device integrated with a programmed Python program was fabricated for both color recognition and the accurate detection of pepsin within 3 min. Under the optimal conditions, this turn-on sensor allowed for the on-site analysis of pepsin with a detection limit of 0.2 µg/mL. Moreover, this strategy was successfully used to assess salivary pepsin to aid in the noninvasive diagnosis of GERD.


Subject(s)
Gastroesophageal Reflux , Saliva , Humans , Saliva/chemistry , Pepsin A/metabolism , Static Electricity , Gastroesophageal Reflux/diagnosis , Gastroesophageal Reflux/metabolism , Hydrogen-Ion Concentration
11.
Anal Chem ; 95(37): 13949-13956, 2023 09 19.
Article in English | MEDLINE | ID: mdl-37659071

ABSTRACT

Iodine is an essential element that is used to make thyroid hormones. However, people usually ignore their iodine nutrition level, thus leading to a series of thyroid diseases, particularly in areas where medical resources are scarce. Thus, development of a portable, economical, and simple method for the detection of urinary iodine is of significant importance. Herein, a solid-phase fluorescence filter effect (SPFFE) induced by iodine was used to develop an SPFFE-based point-of-care testing (POCT) platform for the detection of urinary iodine by coupling with headspace sample introduction. This method can not only alleviate the matrix interference that occurred in the conventional inner filter effect (IFE) but also achieve high sensitivity. Furthermore, the urinary iodine (UI) POCT platform was developed through the integration of a sample pretreatment and fluorescence readout. This whole system costs less than US $20 and provides accurate temperature control and a portable fluorescence reading within 15-20 min. Compared to the traditional IFE-based assay, the SPFFE-based POCT platform allows the selective detection of iodine as low as 10 nM and has a linear range of 0.05-4 µM. In addition, it provides notable visualization from blue-violet to orange-red in the presence of iodine, which tends to indicate the iodine nutritional status of the human body. Eventually, the clinical applicability and feasibility of the UIPOCT platform as an early diagnostic test kit were confirmed by determining the iodine in urine samples from children and pregnant women.


Subject(s)
Iodine , Point-of-Care Systems , Pregnancy , Humans , Child , Female , Pregnant Women , Point-of-Care Testing , Biological Assay
12.
Anal Chem ; 95(37): 14036-14042, 2023 Sep 19.
Article in English | MEDLINE | ID: mdl-37658803

ABSTRACT

A simple solid phase photothermo-induced chemical vapor generation (SP-PT-CVG) is described and used as an environmentally friendly desorption method for the sensitive determination of mercury in water by direct immersion solid phase microextraction (DI-SPME) atomic fluorescence spectrometry (AFS). A DI-SPME array equipped with 20 nano-TiO2-coated tungsten fibers was employed to simultaneously preconcentrate mercury from 20 samples, enabling an extraction throughput of 40 samples per hour. Subsequently, the fibers were drawn from the sample solutions and inserted into an inner tube sealed in a specially designed UV lamp in turn for SP-PT-CVG to generate Hg0, which was swept to an AFS detector for its detection. It is worth noting that the tube served as both a vapor generator and a desorption chamber. This proof-of-concept study confirms the feasibility of solid phase CVG. Compared to conventional CVG carried out in the liquid phase, solid phase CVG not only retains the advantages of conventional CVG but also alleviates the matrix interference on vapor generation and preconcentrates analyte prior to vapor generation, improving analytical performance for liquid state samples. DI-SPME-SP-PT-CVG-AFS provides a limit of detection of 2.3 ng L-1 for mercury determination by AFS. In the proposed method, the combination of DI-SPME and SP-PT-CVG eliminates the tedious derivatization steps required in conventional headspace SPME, thus minimizing toxic reagent consumption and improving extraction throughput. The practicality of DI-SPME-SP-PT-CVG-AFS was evaluated by analyzing two different certified reference materials and river water samples with good spike recoveries (98-107%).

13.
J Hazard Mater ; 459: 132201, 2023 Oct 05.
Article in English | MEDLINE | ID: mdl-37544178

ABSTRACT

Dissolved sulfide tends to species transformation and loss upon leaving the matrix, thus the development of a practical on-site determination of sulfide is crucial for environmental monitoring and human health. In this work, a novel paper-based ratiometric fluorescence sensor was developed for the field analysis of sulfide, which system was constructed by the inner filter effect (IFE) of CdS quantum dots (QDs) toward carbon dots (C-dots). Instead of an aqueous phase system, the conversion of sulfide to its hydride would induce the in-situ formation of CdS QDs on the paper, which acted as an energy acceptor to quench the emission of C-dots, leading to a variation of ratiometric fluorescence from blue to yellow with the increasing concentration of sulfide. Moreover, we proposed a smartphone-based fluorescence capture device integrated with a programmed Python program, accomplishing both color recognition and accurate detection of sulfide. Under the optimal condition, this ratiometric fluorescence sensor allowed for the on-site analysis of sulfide with a limit of detection of 0.05 µM. The accuracy of the sensor was validated via the successful field analysis of environmental water samples with satisfactory recoveries. Compared to other fluorescence methods used for sulfide analysis, this developed system retains the advantages of label-free, low-cost, ease of operation, and miniaturization, showing great potential for the measurement of sulfide on-site, as well as environmental monitoring.

14.
Anal Chem ; 95(29): 10873-10878, 2023 Jul 25.
Article in English | MEDLINE | ID: mdl-37436933

ABSTRACT

The application of headspace solid-phase microextraction (HS-SPME) for mercury preservation and detection still has several shortcomings, including the use of high-temperature desorption chamber, the consumption of expensive reagent (NaBEt4 or NaBPr4), and analyte loss during sample storage. Herein, a self-heating HS-SPME device using a gold-coated tungsten (Au@W) fiber was developed for the field detection of mercury in soil by miniature point discharge optical emission spectrometry (µPD-OES). Hg2+ was reduced to Hg0 with NaBH4 solution and then preconcentrated with the Au@W fiber. The adsorbed Hg0 could be rapidly desorbed by directly heating the fiber with a mini lithium battery and subsequently detected by µPD-OES. A limit of detection (LOD) of 0.008 mg kg-1 was obtained with a relative standard deviation (RSD) of 2.4%. The accuracy of the self-heating HS-SPME was evaluated by analyzing a soil certified reference material (CRM) and nine soil samples with satisfactory recoveries (86-111%). Compared to the conventional external heating method, the proposed method reduces desorption time and power consumption from 80 s and 60 W to 20 s and 2.5 W, respectively. Moreover, the self-heating device enables the µPD-OES system to remove the high-temperature desorption chamber, making it more compact and suitable for field analytical chemistry. Interestingly, the Au@W SPME fiber can be also used for the long-term preservation of mercury with a sample loss rate <5% after 30 days of storage at room temperature.

15.
J Mater Chem B ; 11(28): 6697-6703, 2023 07 19.
Article in English | MEDLINE | ID: mdl-37377067

ABSTRACT

Nanozyme-based colorimetric assays have attracted much attention due to their cost-effectiveness, high stability, and sensitivity. In particular, the catalytic cascade imparted by the biological enzyme is highly selective. However, developing an efficient, one-pot, and pH-universal bio-nanozyme cascade remains challenging. Considering the tunable activity of the photo-activated nanozyme, we herein demonstrated a pH-universal colorimetric assay based on the Sc3+-boosted photocatalytic oxidation of carbon dots (C-dots). As a strong Lewis acid, Sc3+ shows ultra-fast complexation with OH- over a broad pH range and dramatically decreases the pH of the buffer solutions. In addition to regulating the pH, Sc3+ also binds to the C-dots to produce a persistent and strongly oxidizing intermediate based on photo-induced electron transfer. The proposed Sc3+-boosted photocatalytic system was successfully used in a cascade colorimetric assay with biological enzymes for assessing their activity as well as the detection of enzyme inhibitors at neutral and alkaline pH. Instead of designing new nanozymes for catalytic cascades, this work suggests that introducing promoters can be a convenient strategy in practical applications.


Subject(s)
Colorimetry , Scandium , Charcoal , Catalysis , Hydrogen-Ion Concentration
16.
Anal Chem ; 95(18): 7363-7371, 2023 05 09.
Article in English | MEDLINE | ID: mdl-37127404

ABSTRACT

Excessive consumption of Δ9-tetrahydrocannabinol (THC) severely endangers human health and has raised public safety concerns. However, its quantification by readily rapid tools with simplicity and low cost is still challenging. Herein, we found that a G-rich THC aptamer (THC1.2) can tightly bind to thioflavin T (ThT) with strong fluorescence, which would be specifically quenched in the presence of THC. Based on that, a label-free ratiometric fluorescent sensor for the sensing of THC and its metabolite (THC-COOH) based on THC1.2/ThT as a color emitter and red CdTe quantum dots as reference fluorescence was constructed. Notably, a transition of the fluorescent color of the ratiometric probe from green to red can be instantly observed upon the increased concentration of THC and THC-COOH. Furthermore, a portable smartphone-based fluorescence device integrated with a self-programmed Python program was fabricated and used to accomplish on-site monitoring of THC and THC-COOH within 5 min. Under optimized conditions, this ratiometric fluorescent sensor allowed for an instant response toward THC and its metabolite with considerable limits of detection of 97 and 254 nM, respectively. The established sensor has been successfully applied to urine and saliva samples and exhibited satisfactory recoveries (88-116%). This ratiometric fluorescent sensor can be used for the simultaneous detection of THC and THC-COOH with the advantages of rapidness, low cost, ease of operation, and portability, providing a promising strategy for on-site detection and facilitating law enforcement regulation and roadside control of THC.


Subject(s)
Cadmium Compounds , Quantum Dots , Humans , Dronabinol/analysis , Gas Chromatography-Mass Spectrometry , Smartphone , Tellurium , Coloring Agents , Fluorescent Dyes , Limit of Detection
17.
Anal Chem ; 95(19): 7409-7415, 2023 May 16.
Article in English | MEDLINE | ID: mdl-37144840

ABSTRACT

It is still a challenge to accurately determine dissolved sulfide due to its susceptibility to contamination and loss during transportation, storage, and analysis in the laboratory, thus highlighting the necessity for its sensitive field analysis. Herein, a robust nozzle electrode point discharge (NEPD) enhanced oxidation coupling with chemical vapor generation (CVG) is described for the highly efficient and flameless conversion of sulfide (S2-) to SO2. Subsequently, a portable and low-power consumption gas phase molecular fluorescence spectrometry (GP-MFS) was constructed for the highly selective and sensitive determination of the generated SO2 via detecting its molecular fluorescence excited by a zinc hollow cathode lamp. Under optimal conditions, a limit of detection (LOD) of 0.1 µM was obtained for dissolved sulfide with a relative standard deviation (RSD, n = 11) of 2.6%. The accuracy and practicability of the proposed method were validated by the analyses of two certified reference materials (CRMs) and several river and lake water samples with satisfactory recoveries of 99%-107%. This work confirms that NEPD enhanced oxidation is a low energy consumption yet highly efficient method for the flameless oxidation of hydrogen sulfide and thus is suitable for the easy field detection of dissolved sulfide in environmental water by CVG-GP-MFS.

18.
Anal Chim Acta ; 1261: 341184, 2023 Jun 22.
Article in English | MEDLINE | ID: mdl-37147059

ABSTRACT

Dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC) are two important indicators of global carbon cycle. However, there are no portable analyzers available to simultaneously accomplish high-throughput field detection of them in the same sample. Herein, a simple analyzer comprising a dual-mode reactor to accomplish both chemical vapor generation and headspace sampling, and a miniature point discharge optical emission spectrometer (µPD-OES) was developed for simultaneous and high-throughput detection of DIC and DOC in seawater and lake water. Phosphoric acid and persulfate were successively injected into sample solutions to convert DIC and DOC to CO2 under the conditions of magnetic stirring and UV irradiation, respectively. Subsequently, the generated CO2 was swept into the µPD-OES for quantitation of DIC and DOC via monitoring carbon atomic emission at 193.0 nm. Under optimal conditions, limits of detection for DIC and DOC (as C) were both 0.01 mg L-1 with relative standard deviations (n = 20) better than 5% and sample throughput of 80 samples per hour. Compared to conventional analyzers, the proposed instrument provides the advantages of high throughput, compactness, low energy consumption and eliminates expensive instruments. The accuracy of the system was validated by simultaneous determination of DIC and DOC in various water samples in laboratory and field environments.

19.
Anal Bioanal Chem ; 415(18): 3817-3830, 2023 Jul.
Article in English | MEDLINE | ID: mdl-36633622

ABSTRACT

Nanozymes exhibit their great potential as alternatives to natural enzymes. In addition to catalytic activity, nanozymes also need to have biologically relevant catalytic reactions at physiological pH to fit in the definition of an enzyme and to achieve efficient analytical applications. Previous reviews in the nanozyme field mainly focused on the catalytic mechanisms, activity regulation, and types of catalytic reactions. In this paper, we discuss efforts made on the substrate-dependent catalytic activity of nanozymes at neutral pH. First, the discrepant catalytic activities for different substrates are compared, where the key differences are the characteristics of substrates and the adsorption of substrates by nanozymes at different pH. We then reviewed efforts to enhance reaction activity for model chromogenic substrates and strategies to engineer nanomaterials to accelerate reaction rates for other substrates at physiological pH. Finally, we also discussed methods to achieve efficient sensing applications at neutral pH using nanozymes. We believe that the nanozyme is catching up with enzymes rapidly in terms of reaction rates and reaction conditions. Designing nanozymes with specific catalysis for efficient sensing remains a challenge.


Subject(s)
Nanostructures , Catalysis , Hydrogen-Ion Concentration , Chromogenic Compounds
20.
Cardiol J ; 30(1): 105-116, 2023.
Article in English | MEDLINE | ID: mdl-33634845

ABSTRACT

BACKGROUND: The contribution of sex and initial clinical presentation to the long-term outcomes in patients undergoing percutaneous coronary intervention (PCI) is still debated. METHODS: Individual patient data from 5 Korean-multicenter drug-eluting stent (DES) registries (The GRAND-DES) were pooled. A total of 17,286 patients completed 3-year follow-up (5216 women and 12,070 men). The median follow-up duration was 1125 days (interquartile range 1097-1140 days), and the primary endpoint was cardiac death at 3 years. RESULTS: The clinical indication for PCI was stable angina pectoris (SAP) in 36.8%, unstable angina pectoris (UAP) or non-ST-segment elevation myocardial infarction (NSTEMI) in 47.4%, and ST-segment elevation myocardial (STEMI) in 15.8%. In all groups, women were older and had a higher proportion of hypertension and diabetes mellitus compared with men. Women presenting with STEMI were older than women with SAP, with the opposite seen in men. There was no sex difference in cardiac death for SAP or UAP/NSTEMI. In STEMI patients, the incidence of cardiac death (7.9% vs. 4.4%, p = 0.001), all-cause mortality (11.1% vs. 6.9%, p = 0.001), and minor bleeding (2.2% vs. 1.2%, p = 0.043) was significantly higher in women. After multivariable adjustment, cardiac death was lower in women for UAP/NSTEMI (HR 0.69, 95% CI 0.53-0.89, p = 0.005), while it was similar for STEMI (HR 0.97, 95% CI 0.65-1.44, p = 0.884). CONCLUSIONS: There was no sex difference in cardiac death after PCI with DES for SAP and UAP/NSTEMI patients. In STEMI patients, women had worse outcomes compared with men; however, after the adjustment of confounders, female sex was not an independent predictor of mortality.


Subject(s)
Angina, Stable , Drug-Eluting Stents , Myocardial Infarction , Non-ST Elevated Myocardial Infarction , Percutaneous Coronary Intervention , ST Elevation Myocardial Infarction , Male , Humans , Female , Myocardial Infarction/etiology , ST Elevation Myocardial Infarction/diagnosis , ST Elevation Myocardial Infarction/surgery , Percutaneous Coronary Intervention/adverse effects , Angina, Unstable/diagnosis , Angina, Unstable/therapy , Angina, Stable/diagnosis , Angina, Stable/therapy , Registries , Death , Treatment Outcome
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