Cotyledon-Specific Flow Evaluation of Rhesus Macaque Placental Injury Using Ferumoxytol Dynamic Contrast-Enhanced MRI.

BACKGROUND: Recently, dynamic contrast-enhanced (DCE) MRI with ferumoxytol as contrast agent has recently been introduced for the noninvasive assessment of placental structure and function throughout. However, it has not been demonstrated under pathological conditions. PURPOSE: To measure cotyledon-specific rhesus macaque maternal placental blood flow using ferumoxytol DCE MRI in a novel animal model for local placental injury. STUDY TYPE: Prospective animal model. SUBJECTS: Placental injections of Tisseel (three with 0.5 mL and two with 1.5 mL), monocyte chemoattractant protein 1 (three with 100 µg), and three with saline as controls were performed in a total of 11 rhesus macaque pregnancies at approximate gestational day (GD 101). DCE MRI scans were performed prior (GD 100) and after (GD 115 and GD 145) the injection (term = GD 165). FIELD STRENGTH/SEQUENCE: 3 T, T1-weighted spoiled gradient echo sequence (product sequence, DISCO). ASSESSMENT: Source images were inspected for motion artefacts from the mother or fetus. Placenta segmentation and DCE processing were performed for the dynamic image series to measure cotyledon specific volume, flow, and normalized flow. Overall placental histopathology was conducted for controls, Tisseel, and MCP-1 animals and regions of tissue infarctions and necrosis were documented. Visual inspections for potential necrotic tissue were conducted for the two Tisseelx3 animals. STATISTICAL TESTS: Wilcoxon rank sum test, significance level P < 0.05. RESULTS: No motion artefacts were observed. For the group treated with 1.5 mL of Tisseel, significantly lower cotyledon volume, flow, and normalized flow per cotyledon were observed for the third gestational time point of imaging (day ~145), with mean normalized flow of 0.53 minute-1 . Preliminary histopathological analysis shows areas of tissue necrosis from a selected cotyledon in one Tisseel-treated (single dose) animal and both Tisseelx3 (triple dose) animals. DATA CONCLUSION: This study demonstrates the feasibility of cotyledon-specific functional analysis at multiple gestational time points and injury detection in a placental rhesus macaque model through ferumoxytol-enhanced DCE MRI. LEVEL OF EVIDENCE: NA TECHNICAL EFFICACY: Stage 2.

Impact of COVID-19 pandemic responses on tuberculosis incidence: insights from Shantou, China.

BACKGROUND: Various measures taken against the COVID-19 pandemic are not only effective in reducing the spread of the disease, but also lead to some unexpected results. This article regarded these measures as an intervention and explored their impact on the incidence of tuberculosis in Shantou, China. METHODS: The incidence rate and the surveillance data of tuberculosis from January 1st, 2018 to December 31st, 2021 were provided by the Shantou Tuberculosis Prevention and Control Institute. Data were divided into pre-pandemic period (January 1st, 2018 - December 31st, 2019) and pandemic periods (January 1st, 2020 - December 31st, 2021). The Interrupted Time Series (ITS) was used to analyze the trend of tuberculosis incidence prior to and during the COVID-19 epidemic. RESULTS: The results showed that the incidence of tuberculosis cases in Shantou decreased significantly (p < 0.05) during the pandemic as compared to that prior to the pandemic. Among them, the 45-64 age group and the 65 + age group have statistically significant declines. When patients were stratified by occupation, the unemployed and those working in agriculture reduced the most. CONCLUSIONS: In response to the pandemic, measures like lockdowns and quarantines seem to have reduced tuberculosis incidence. However, this does not imply a true decrease. Underlying causes for the reduced true incidence need further scrutiny. Findings offer a preliminary exploration of interventions designed for one disease but functioning as unexpected results for another.

The "supercompensation" effect of children's lockdown during COVID-19: based on the analysis of changes in physical activity, sleep, and psychology.

OBJECTIVE: To investigate the "supercompensation" effect of preschoolers during the coronavirus disease 2019 lockdown by comparing the changes in physical activity (PA), psychological, and sleep indicators before and after the lockdown. METHODS: A total of 127 children (aged 3-6 years) were recruited. Before and after the lockdown, the children's PA levels were measured using the ActiGraph GT3X+, and their psychological and sleep indicators were measured using the Strengths and Difficulties Questionnaire (SDQ) and Child Sleep Habit Questionnaire (CSHQ), respectively. RESULTS: Regarding PA, the children's total physical activity, low-intensity physical activity, and medium-intensity physical activity (MVPA) were higher after the lockdown than before the lockdown, with significant differences in MVPA (p < 0.05). Regarding psychology, the children's SDQ and multidimensional scores were better after the lockdown than before the lockdown, with a significant difference in SDQ scores (p < 0.05). Regarding sleep, the children's CSHQ scores were better after the lockdown than before the lockdown, with a highly significant difference in CSHQ scores (p < 0.01). CONCLUSION: After lockdown, children's PA, psychological, and sleep effects were "supercompensated." In particular, the PA of preschoolers before, during, and after the lockdown may show a "baseline-inhibition-supercompensation" process.

Relationship between 24-h activity behavior and body fat percentage in preschool children: based on compositional data and isotemporal substitution analysis.

OBJECTIVE: This study aims to elucidate the dose‒response relationship between 24-h activity behaviors and body fat percentage (BFP) in Chinese preschool children using a compositional isotemporal substitution model (ISM). METHODS: In a cross-sectional design, 881 children aged 3-6 from urban and rural areas of Jiangxi Province were sampled. Activity behaviors, including sedentary behavior (SB), low-intensity physical activity (LPA), and moderate- to high-intensity physical activity (MVPA), were measured using accelerometers. Sleep patterns were assessed through questionnaires, and BFP was determined by bioelectrical impedance analysis (BIA). The study employed compositional data analysis (CoDA) and ISM to estimate the impact of reallocating durations of different activity behaviors on BFP. RESULTS: Higher BFP was found in urban vs. rural children, decreasing with age. Overweight and obesity rates were 10.6% and 7.6%, respectively, above national averages. MVPA and LPA were negatively correlated with BFP, while SB was positively correlated. A 30-min MVPA reduction significantly increased zBFR, particularly in overweight children. Gender-specific nuances revealed that boys' MVPA negatively influenced zBFP (ß = -0.155), P < 0.05), while girls' SB positively impacted zBFP (ß = 0.636, P < 0.01). Isotemporal simulations emphasized amplified effects in overweight children, with boys' zBFR rising rapidly when MVPA was substituted and girls displaying a notable substitution effect between SB and LPA. CONCLUSION: BFP is closely linked to 24-h activity behaviors, notably in overweight and obese preschoolers. ISM identified MVPA as a critical influencer, with a 30-min reduction substantially increasing BFP. Gender disparities were evident, implicating MVPA in boys and LPA and SB in girls.

Electroacupuncture remodels the extracellular matrix and promotes synaptic plasticity in a mouse model of depression.

Depression is a chronic and recurrent disease without satisfactory treatment strategies. The therapeutic effect of acupuncture is well known in Traditional Chinese medicine (TCM) due to its unique non-pharmacological nature. Electroacupuncture (EA) for antidepressant therapy has been widely recognized and used in clinic. In this study, the lipopolysaccharide (LPS)-induced depression mice model was used to evaluate the anti-depressant effects of EA treatment. Open Field Test (OFT), Force Swimming Test (FST), and Sucrose Preference Test (SPT) were utilized to detect the ethological alterations in mice. The transcriptology technique was used to evaluate the changes in the hippocampal transcriptome in different groups. We measured protein levels using Western blot and immunohistochemistry. Our data showed that LPS induced ethological alterations in mice and enhanced the gene expression related to gene ontology such as the banded collagen fibril, fibrillar collagen trimer, and collagen fibril organization, pathways such as collagen chain trimerization, collagen biosynthesis and modifying enzymes, and collagen formation. EA could reverse the ECM deposition by inhibiting collagen type Ⅳ trimer, extracellular matrix organization, and collagen formation. EA could enhance the MMP1 and MMP9 expression and promote synaptic plasticity. These data indicated that EA possesses an antidepressant effect, this may achieve by increasing MMPs expression and then remodeling the ECM surrounding the neurons, ultimately repairing neural circuits and promoting synaptic plasticity.

Ferumoxytol dynamic contrast enhanced magnetic resonance imaging identifies altered placental cotyledon perfusion in rhesus macaques†.

Identification of placental dysfunction in early pregnancy with noninvasive imaging could be a valuable tool for assessing maternal and fetal risk. Dynamic contrast enhanced (DCE) magnetic resonance imaging (MRI) can be a powerful tool for interrogating placenta health. After inoculation with Zika virus or sham inoculation at gestation age (GA) 45 or 55 days, animals were imaged up to three times at GA65, GA100, and GA145. DCE MRI images were acquired at all imaging sessions using ferumoxytol, an iron nanoparticle-based contrast agent, and analyzed for placental intervillous blood flow, number of perfusion domains, and perfusion domain volume. Cesarean section was performed at GA155, and the placenta was photographed and dissected for histopathology. Photographs were used to align cotyledons with estimated perfusion domains from MRI, allowing comparison of estimated cotyledon volume to pathology. Monkeys were separated into high and low pathology groups based on the average number of pathologies present in the placenta. Perfusion domain flow, volume, and number increased through gestation, and total blood flow increased with gestation for both low pathology and high pathology groups. A statistically significant decrease in perfusion domain volume associated with pathology was detected at all gestational ages. Individual perfusion domain flow comparisons demonstrated a statistically significant decrease with pathology at GA100 and GA145, but not GA65. Since ferumoxytol is currently used to treat anemia during human pregnancy and as an off-label MRI contrast agent, future transition of this work to human pregnancy may be possible.

Laser triangulation measurement system with Scheimpflug calibration based on the Monte Carlo optimization strategy.

We propose a linear laser triangulation measurement system using Scheimpflug calibration based on the Monte Carlo optimization strategy. A Scheimpflug inclination camera calibration model is introduced in the measurement system for improving the image definition in small-range measurements with a large depth-of-field. To address the nonlinear optimization problem between the instrument resolution and measurement range, the Monte Carlo method is adopted to determine the optimal optical parameters (scattering angle, Scheimpflug angle, and focus length) in a practical measurement system. Furthermore, we experimentally constructed the measurement system to demonstrate the measurement precision by measuring a standard step block (measurement range 15 mm). The performance parameters of the maximum measurement error, maximum standard deviation, and linearity are obtained as ±7 µm, 0.225 µm, and 0.046%, respectively. Finally, the proposed measurement system based on the Monte Carlo optimization strategy is promising for high-precision measurements in industrial applications and provides guidance for optimizing the design parameters of ranging measurement sensors.

A Concise Total Synthesis of (-)-Berkelic Acid.

Reported here is a concise total synthesis of (-)-berkelic acid in eight linear steps. This synthesis features a Catellani reaction/oxa-Michael cascade for the construction of the isochroman scaffold, a one-pot deprotection/spiroacetalization operation for the formation of the tetracyclic core structure, and a late-stage Ni-catalyzed reductive coupling for the introduction of the lateral chain. Notably, four stereocenters are established from a single existing chiral center with excellent stereocontrol during the deprotection/spiroacetalization process. Stereocontrol of the intriguing deprotection/spiroacetalization process is supported by DFT calculations.

An Improved Low-Noise Processing Methodology Combined with PCL for Industry Inspection Based on Laser Line Scanner.

This paper introduces a three-dimensional (3D) point cloud data obtained method based on a laser line scanner and data processing technology via a PCL open project. This paper also provides a systematical analysis of the error types of laser line scanner and common error reducing solutions and calibration of the laser line scanner. The laser line scanner is combined with a precision motorized stage to obtain the 3D information of a measurand, and the format of point cloud data is converted via the set of x, y, and z coordinates. The original signal is processed according to the noise signal types of the raw point cloud data. This paper introduced a denoise process step by step combining various segmentation methods and a more optimized three-dimensional data model is obtained. A novel method for industry inspection based on the numerous point cloud for the dimensions evaluation via feature extraction and the deviation of complex surface between scanned point cloud and designed point cloud via registration algorithm is proposed. Measurement results demonstrate the good performance of the proposed methods. An obtained point cloud precision of ±10 µm is achieved, and the precision of dimension evaluation is less than ±40 µm. The results shown in the research demonstrated that the proposed method allows a higher precision and relative efficiency in measurement of dimensions and deviation of complex surfaces in industrial inspection.

Palladium(II)-Initiated Catellani-Type Reactions.

The Catellani reaction is known as a powerful strategy for the expeditious synthesis of highly substituted arenes and benzo-fused rings, which are usually difficult to access through traditional cross-coupling strategies. It utilizes the synergistic interplay of palladium and norbornene catalysis to facilitate sequential ortho C-H functionalization and ipso termination of aryl halides in a single operation. In classical Catellani-type reactions, aryl halides are mainly used as the substrates, and a Pd0 catalyst is required to initiate the reaction. Nevertheless, recent advances showcase that Catellani-type reactions can also be initiated by a PdII catalyst with different starting materials instead of aryl halides via different reaction mechanisms and under different conditions. This emerging concept of PdII /norbornene cooperative catalysis has significantly advanced Catellani-type reactions, thus enabling future developments of this field. In this Minireview, PdII -initiated Catellani-type reactions and their application in the synthesis of bioactive molecules are summarized.

Epoxides as Alkylating Reagents for the Catellani Reaction.

We report a cooperative catalytic system comprising a PdII complex, XPhos, and the potassium salt of 5-norbornene-2-carboxylic acid that enables the use of epoxides as alkylating reagents in the Catellani reaction, thereby expanding the existing paradigm of this powerful transformation. The potassium salt of inexpensive 5-norbornene-2-carboxylic acid acts as both mediator and base in the process. This mild, chemoselective, scalable, and atom-economical protocol is compatible with a wide variety of readily available functionalized aryl iodides and epoxides, as well as terminating olefins. The resulting products undergo facile oxa-Michael addition to furnish ubiquitous isochroman scaffolds.

Velocity-selective arterial spin labeling perfusion measurements in 2nd trimester human placenta with varying BMI.

INTRODUCTION: Proper placental development is crucial to fetal health but is challenging to functionally assess non-invasively and is thus poorly characterized in populations. Body mass index (BMI) has been linked with adverse outcomes, but the causative mechanism is uncertain. Velocity-selective arterial spin labeling (VS-ASL) MRI provides a method to non-invasively measure placental perfusion with robustness to confounding transit time delays. In this study, we report on the measurement of perfusion in the human placenta in early pregnancy using velocity-selective arterial spin labeling (VS-ASL) MRI, comparing non-obese and obese participants. METHODS: Participants (N = 97) undergoing routine prenatal care were recruited and imaged with structural and VS-ASL perfusion MRI at 15 and 21 weeks gestation. Resulting perfusion images were analyzed with respect to obesity based on BMI, gestational age, and the presence of adverse outcomes. RESULTS: At 15 weeks gestation BMI was not associated with placental perfusion or perfusion heterogeneity. However, at 21 weeks gestation BMI was associated with higher placental perfusion (p < 0.01) and a decrease in perfusion heterogeneity (p < 0.05). In alignment with past studies, perfusion values were also higher at 21 weeks compared to 15 weeks gestation. In a small cohort of participants with adverse outcomes, at 21 weeks lower perfusion was observed compared to participants with uncomplicated pregnancies. DISCUSSION: These results suggest low placental perfusion in the early second trimester may not be the culpable factor driving associations of obesity with adverse outcomes.

A new carbazole based fluorescent probe with AIE characteristic for detecting and imaging hydrazine in living cells, mungbean sprouts, Arabidopsis thaliana, and practical samples.

In this study, we report a new carbazole-malononitrile fluorescent probe CBC with an interesting aggregation-induced emission (AIE) characteristic. Probe CBC could rapidly and selectively detect hydrazine (N2H4) in ～100% aqueous media, and also exhibit an exceedingly low detection limit of 6.3 nM for sensitively detecting N2H4. The sensing mechanism of CBC towards N2H4 has been well demonstrated through the spectra of 1H NMR, HRMS and FTIR. Interestingly, probe CBC was applied to visualize and detect gaseous and aqueous N2H4 with sensitive color changes. Importantly, probe CBC was applied to effectively detect N2H4 in practical samples such as soil, human serum, human urine, plants, foods and beverages, as well as sensitively sense and image N2H4 in biological systems including living mungbean sprouts, Arabidopsis thaliana, and HeLa cells.

Acupuncture for generalized anxiety disorder: a study protocol for a randomized controlled trial.

During the COVID-19 outbreak, there was a sharp increase in generalized anxiety disorder (GAD). Acupuncture therapy has the advantages of accurate clinical efficacy, safety and reliability, few adverse reactions, and no dependence, and is gradually becoming one of the emerging therapies for treating GAD. We present a study protocol for a randomized clinical trial with the aim of exploring the mechanism of brain plasticity in patients with GAD and evaluate the effectiveness and reliability of acupuncture treatment. Transcranial magnetic stimulation (TMS) will be used to assess cortical excitability in GAD patients and healthy people. Sixty-six GAD patients meeting the inclusion criteria will be randomly divided into two groups: TA group, (treatment with acupuncture and basic western medicine treatment) and SA group (sham acupuncture and basic western medicine treatment). Twenty healthy people will be recruited as the control group (HC). The parameters that will be evaluated are amplitude of motor evoked potentials (MEPs), cortical resting period (CSP), resting motor threshold (RMT), and Hamilton Anxiety Scale (HAMA) score. Secondary results will include blood analysis of γ-aminobutyric acid (GABA), glutamate (Glu), glutamine (Gln), serotonin (5-HT), and brain-derived nerve growth factor (BDNF). Outcomes will be assessed at baseline and after the intervention (week 8). This study protocol is the first clinical trial designed to detect differences in cerebral cortical excitability between healthy subjects and patients with GAD, and the comparison of clinical efficacy and reliability before and after acupuncture intervention is also one of the main contents of the protocol. We hope to find a suitable non-pharmacological alternative treatment for patients with GAD.

Fire acupuncture for plaque psoriasis case series.

OBJECTIVE: To investigate the clinical efficacy of fire acupuncture (FA) on plaque psoriasis (PP), exploring its suitable syndrome types, in order to achieve better therapeutic effects, accelerate the possibility of psoriasis skin lesion recovery, and provide assistance for clinical treatment. METHODS: A total of 8 patients with PP aged between 18 and 60 years were recruited and treated with FA once a week, and the lesion area and severity index (PASI), visual analog scale and pruritus were measured before, 2, 4 and 8 weeks after treatment and at the follow-up period (week 12), respectively. Visual analog scale, and dermoscopy were used for assessment. RESULTS: All patients showed improvement in pruritus after 1 FA treatment, and lesions were reduced to varying degrees after 2 weeks. Except for patients 5 and 8, who only achieved effective results due to severe disease, all other patients with psoriasis achieved significant results at 8 weeks after treatment. CONCLUSION: FA can significantly control the development of lesions, reduce the symptoms of PP lesions and pruritus, and help prevent psoriasis recurrence.

Depression and macrophages: A bibliometric and visual analysis from 2000 to 2022.

BACKGROUND: Macrophages are closely related to the occurrence and development of depression, but there are few bibliometric studies on the role of macrophages in depression. We aim to examine the current state and frontier trends of the research on macrophages in depression from 2000 to 2022 in this study, so as to establish a new direction for follow-up research. METHODS: The literature scan covering the period 2000 to 2022 was performed on macrophages in depression, which were analyzed with Citespace 6.1.R2 and VOSviewer 1.6.18 after manual screening, including country publications, institutions, authors, journals, keywords, and references. RESULTS: This study included 387 papers in total. There has been an increase in the number of published papers since 2009. In terms of productivity, the United States and Ohio State University are the most productive countries and institutions. The most cited author is Maes M, cited 173 times, which has made a great contribution to the study of macrophages in depression. In terms of publications, Pariante CM, Drexhage HA. have the largest number, each author with five. Brain Behavior and Immunity is the most published and cited journals. The highest burst intensity keyword is microglia, and the highest burst intensity reference is Dowlati Y, 2010. CONCLUSION: Research hotspots and trends are analyzed and predicted in this study, which will facilitate the development of macrophage research in depression, so as to provide a reference for further research in this field.

Highly sensitive fluorescent sensor for hypochlorite in nearly 100% aqueous solution and its application for live-cell, plant and zebrafish imaging.

A new ICT type D-π-A structured chemosensor DTB derived from a bithiophene-benzothiazole derivative has been synthesized. Sensor DTB showed a colorimetric and fluorometric dual-signaling response to hypochlorite (ClO-) in EtOH/HEPES solution (1/99, V/V, pH = 7.4, nearly 100% aqueous solution). Sensor DTB exhibited well specificity, high sensitivity and rapidity (<1 min) for ClO- with a detection limit of 25 nM. Sensor DTB features remarkable color changes and significant fluorescence "turn-on" response (ca. 45 fold) after treating with ClO-. Comprehensive analyses by 1H NMR, TLC, FTIR, HRMS, UV-vis, fluorescence and DFT illustrated that ClO- reacted with the CC bond of DTB, generating fluorophore 2T-CHO, leading to strong blue fluorescence. Interestingly, DTB loaded colorimetric test strips were established for rapid and real-time visual detection of ClO-. Furthermore, the DTB was successfully applied to quantitatively and sensitively detect ClO- in 84 disinfectant, bio-fluids (human serum and urine) and actual water samples. Importantly, the biocompatible DTB has been employed for visualizing and bioimaging ClO- in mung bean sprouts, Arabidopsis, live cells and zebrafish. These investigations demonstrate that DTB has great potentials for detecting ClO- in various biosystems and environments. This work would offer a new idea for developing multifunctional sensors with better performance for chemo/biosensors.

Evaluating on-board kVCT- and MVCT-based dose calculation accuracy using a thorax phantom for helical tomotherapy treatments.

Purpose.To evaluate the impact of CT number calibration and imaging parameter selection on dose calculation accuracy relative to the CT planning process in thoracic treatments for on-board helical CT imaging systems used in helical tomotherapy.Methods and Materials.Direct CT number calibrations were performed with appropriate protocols for each imaging system using an electron density phantom. Large volume and SBRT treatment plans were simulated and optimized for planning CT scans of an anthropomorphic thorax phantom and transferred to registered kVCT and MVCT scans of the phantom as appropriate. Relevant DVH metrics and dose-difference maps were used to evaluate and compare dose calculation accuracy relative to the planning CT based on a variation in imaging parameters applied for the on-board systems.Results.For helical kVCT scans of the thorax phantom, median differences in DVH parameters for the large volume treatment plan were less than ±1% with dose to the target volume either over- or underestimated depending on the imaging parameters utilized for CT number calibration and thorax phantom acquisition. For the lung SBRT plan calculated on helical kVCT scans, median dose differences were up to -2.7% with a more noticeable dependence on parameter selection. For MVCT scans, median dose differences for the large volume plan were within +2% with dose to the target overestimated regardless of the imaging protocol.Conclusion.Accurate dose calculations (median errors of <±1%) using a thorax phantom simulating realistic patient geometry and scatter conditions can be achieved with images acquired with a helical kVCT system on a helical tomotherapy unit. This accuracy is considerably improved relative to that achieved with the MV-based approach. In a clinical setting, careful consideration should be made when selecting appropriate kVCT imaging parameters for this process as dose calculation accuracy was observed to vary with both parameter selection and treatment type.

New dual-responsive fluorescent sensor for hypochlorite and cyanide sensing and its imaging application in live cells and zebrafish.

Excessive levels of cyanide (CN-) and hypochlorite (ClO-) anions are the significant threats to the human health and the environment. Thus, great efforts have been to design and synthesize molecular sensors for the simple, instantaneous and efficient detecting environmentally and biologically important anions. Currently, developing a single molecular sensor for multi-analyte sensing is still a challenging task. In our present work, we developed a new molecular sensor (3TM) based on oligothiophene and Meldrum's acid units for detecting cyanide and hypochlorite anions in biological, environmental and food samples. The detecting ability of 3TM has been examined to various testing substances containing amino acids, reactive oxygen species, cations and anions, showing its high selectivity, excellent sensitivity, short response time (ClO-: 30 s, CN-: 100 s), and broad pH working range (4-10). The detection limits were calculated as 4.2 nM for ClO- in DMSO/H2O (1/8, v/v) solution and 6.5 nM for CN- in DMSO/H2O (1/99, v/v) solution. Sensor 3TM displayed sharp turn-on fluorescence increasement (555 nm, 435 nm) and sensitive fluorescence color changes caused by CN-/ClO-, which is ascribed to the nucleophilic addition and oxidation of ethylenic linkage by cyanide and hypochlorite, respectively. Moreover, sensor 3TM was applied for hypochlorite and cyanide detecting in real-world water, food samples and bio-imaging in live cells and zebrafish. To our knowledge, the developed 3TM sensor is the seventh single-molecular sensor for simultaneous and discriminative detecting hypochlorite and cyanide in food, biological and aqueous environments using two distinct sensing modes.

A dual-responsive fluorescent turn-on sensor for sensitively detecting and bioimaging of hydrazine and hypochlorite in biofluids, live-cells, and plants.

Hydrazine (N2H4) and hypochlorite (ClO-) are extremely harmful to the public health, so it is vitally necessary to detect them in living system. Herein, we developed a new phenthiazine-thiobarbituric acid based dual-analyte responsive fluorescent sensor PT for visually distinguishing and detecting N2H4 and ClO-. PT underwent N2H4/ClO--induced CC breakage, achieving olive-drab/brilliant green fluorescence lighting-up response towards N2H4/ClO- with superb specifity, ultra-sensitivity (detection limit: 15.4 nM for N2H4, 13.7 nM for ClO-), and ultra-fast response (N2H4: <15 s, ClO-: <20 s). The mechanisms for sensing N2H4 and ClO- were investigated with support of spectral measurements and DFT investigation. Sensor based paper-strip/silica-gel device was developed for in-field supervision and on-site monitoring of gaseous and aqueous N2H4 and ClO- solution. In addition, the PT was also applied for quantitatively detecting N2H4 and ClO- in soil, food, plants and bio-fluids. Moreover, PT was utilized to visualize exogenous N2H4 and ClO- in living plants and live-cells, demonstrating this sensor utilized as a powerful tool to detect N2H4 and ClO- in biological fields.