Construction of coumarin-appended calix[4]arene-based fluorescence sensor for the detection of carbofuran in cabbage

This study presents a novel approach for the detection of carbofuran (CBF) insecticide by systematically exploring a calix[4]arene-derived fluorescence probe, CouC4S, functionalized with two coumarin-labelled cystamine linkages at the narrow edge of the calix[4]arene platform. The proposed method showed a fluorescence "signal - off" effect when CBF binds with CouC4S by quenching the fluorescence intensity of CouC4S. Its limit of detection was as low as 5.55 μM according to the emission study. The working concentration range for this ligand was observed to be up to 5-65 μM. This method could be applied for the on-spot detection of CBF in real samples such as cabbage by spiking CBFvia in situ experiments, which exhibited a limit of detection of 8.823 ppm. For the further confirmation of CouC4S:CBF binding, cyclic voltammetry, differential pulse voltammetry, powder X-ray diffraction, FT-IR spectroscopy, 1H NMR titration, MALDI-TOF and computational investigations were carried out.

Lab on chip for testing of repurposed drugs

The lab-on-chip technique broadly comprises of microfluidics and aims to progress multidimensionally by changing the outlook of medicine and pharmaceuticals as it finds it roots in miniaturization. Moreover, microfluidics facilitates precise physiological simulation and possesses biological system-mimicking capabilities for drug development and repurposing. Thus, organs on chip could pave a revolutionary pathway in the field of drug development and repurposing by reducing animal testing and improving drug repurposing.

Paper disc interfaced Prussian blue nanocube modified immunodevice for electrochemical detection of diverse biomarker at point of care

The detection of specific biomarkers is used in various phases of the diagnosis of plant and human diseases, from prognosis to monitoring. Herein, we report a Prussian blue nanocube-modified immunodevice interfaced with a paper disc for the detection of plant biomarkers via streptavidin-biotin recognition. The detection ability of the immunodevice was assessed using Potato virus X as a model biomarker and analyzed using cyclic voltammetry, differential pulse voltammetry, and electrochemical impedance spectroscopy. The immunodevice displayed excellent performance for Potato virus X detection with a detection limit of 0.92 nM (3S/N). The selectivity of the fabricated Potato virus X immunodevice was investigated using closely associated antigens, such as potato aucuba mosaic virus, Potato virus Y, and Potato virus A. The Potato virus X immunodevice exhibited ∼ 90 % recovery in spiked complex plant samples with a relative error of ∼ 9 %. Furthermore, the immunodevice was used to screen for Potato virus X in 10 samples from potato tubers and leaves. The paper-disc-interfaced immunodevice was also evaluated by detecting other biomarkers, such as potato aucuba mosaic virus in plant diseases and C-reactive protein in human ones. This immunodevice may allow the on-site monitoring of diverse biomarkers by simplifying the current point of care diagnostic tools.

Tailored calix[4]arene-gold nanoconjugate as a ultra-sensitive immunosensing nanolabel

The construction of highly sensitive and specific immunosensing nanolabels have attracted tremendous attention in the development of reliable point-of-care disease diagnostics. However, there are still challenges with traditional immunoassays, such as complicated and time-consuming procedure, the use of enzyme label, non-specificity, and require readers for detection. Therefore, we have designed and developed site-directed antibody-immobilized calix[4]arene-gold nanoconjugate based colorimetric immunosensing nanolabel to offer high sensitivity. The prepared nanolabel enabled oriented binding of the antibodies by providing full accessibility of Fab domain for antigen binding. The improved sensitivity of the developed nanolabel was evaluated using vertical flow immunoassay (VFIA) for detecting C-reactive protein (CRP) with a lower detection limit up to 1 ng/ml. Our developed nanolabel was found to be highly specific, easy, quick, and appropriate for onsite detection. The nanolabel is validated with spiked blood samples which exhibited ~90% recovery having a relative error of ~2%. Furthermore, the nanolabel was also used for screening of human blood real samples which showed relative error of ~0.6%. The developed nanolabel can be utilized as a potential nanolabel for the quantitative detection of various biomolecules in clinical samples.

Seed Priming with ZnO and Fe3O4 Nanoparticles Alleviate the Lead Toxicity in Basella alba L. through Reduced Lead Uptake and Regulation of ROS

The increased lead (Pb) content in the environment has an impact on all living beings, including plant growth and quality. The present study aims to investigate the protective roles of zinc (Zn)- and iron (Fe)- nanoparticles (NPs) in alleviating stress symptoms caused by lead (Pb) exposure in Basella alba seedlings. For this purpose, 15 different treatment combinations of seed priming with two NPs at 0 and 200 mg L−1, and five Pb levels (0, 4, 8, 15, 20 mM) were chosen. Pb stress (20 mM) was found to reduce seed germination by 72.8% and seedling growth, particularly root length, by 92% when compared to the control. Under different Pb concentrations, seed priming with ZnNPs (200 mg L−1) and FeNPs (200 mg L−1) increased seed germination by 34.7% and 54.9%, respectively, and root length by 152.9% and 252.9%, respectively. In 20 mM Pb stress, NPs primed seedling showed decrease in Pb content by 33.7% with ZnNPs and 32.6% with FeNPs. Increased Pb stress resulted in increased reactive oxygen species (ROS) generation (H2O2) and lipid peroxidation (MDA) compared to non-Pb stressed seedlings. However, increased antioxidants in the NPs treatments such as SOD, CAT, POD and proline content, scavenged these ROS. Considering all the parameters under study, priming alleviated Pb stress in the following order: FeNPs > ZnNPs > hydropriming > control. To summarise, seed priming with Zn- and Fe-NPs has the potential to alleviate Pb toxicity via reduced Pb uptake, ROS generation and lipid peroxidation as well as increased proline content and activation of antioxidant enzymatic system.

Microfluidic tools for veterinary and zoonotic disease diagnostics

Animal disease diagnostics has linked as the cause and cure of any disease. It also plays a vital role in disease management and prevention. A small outbreak of disease can pose a threat to the entire animal community as we realized in corona pandemic. Thus, to ensure the overall welfare of animals and disease spread monitoring, the development of detection tools for veterinary diagnosis becomes essential. Currently, the animal disease diagnosis is relied on laboratory-based testing. There is a parallel necessity for rapid, reliable and low-cost diagnostic tests to be done by intervention of growing area such as microfluidic platform. Therefore, in this chapter, we have discussed about various microfluidic platform and their application for early diagnosis of veterinary disease. Followed by, we also lightened on future perspective of role of microfluidic in animal disease diagnostics.

Optimizing Small, Low-Risk, Unruptured Intracranial Aneurysm Treatment Using Game Theory

The incidental diagnosis of unruptured intracranial aneurysms has been increasing in the past several decades. A significant proportion represent small, low-risk, unruptured intracranial aneurysms for which there is equipoise on whether to offer treatment or conservative management. Given this uncertainty, patients may not always be comfortable with their physicians' recommendations. Herein, we use game theory to study the interactions between physicians and patients to determine how conflict and cooperation affect the management of small, low-risk, unruptured intracranial aneurysms. We constructed a game theory model of the interaction between physicians and patients with respect to decision-making for a small, low-risk, unruptured intracranial aneurysm in an asymptomatic patient when there is perceived equipoise between whether to treat or manage conservatively. Assuming that both the physician and patient are rational and eliciting individual patient preferences is not practical, the physician should play the game based on an ex ante probability of meeting a patient with a certain type of preference. This recommendation means that the expectations of the physician regarding the patient's preferences should guide the decision to offer treatment or conservative management as a first option for a small, asymptomatic, low-risk, unruptured intracranial aneurysm for which there is clinical equipoise.

Challenges and opportunities in micro/nanofluidic and lab-on-a-chip

Fluidic systems are prevalent in many areas of science due to its advantage in miniaturization, development of unique tools for diseases diagnosis and biomolecule separation. In the chapter, we will describe some of the key features of microfluidic/nanofluidic (MF/NF) and lab-on-a-chip system in diverse field over the past years. In addition, we will highlight the major challenges for the microfluidic/nanofluidic and lab-on-a-chip system. All-purpose and universal micro/nanofluidic platforms that can perform multiplexed assays on real biological samples are in high demand. However, the adoption of novel microfluidic devices has been carried out at a slow pace due to translation gap in development of new devices to realization into commercialization. By addressing the challenges of system integration, low-cost technology availability, rapid regulatory approval, and clinical acceptance, a pipeline of promising microdevice technologies can be developed.

An introduction to microfluidics and their applications

In the past decade, microfluidics and lab-on-chip are rapidly growing area. It has been used for number of biology to biotechnology and medicine applications. It has the potential to reduce cost of reagent and time of experiment. It has been used integrated with automation for extraction and detection of protein, nucleic acids, enzymes, metabolites and delivery of drug to target location. It has been used for drug discovery, high throughput screening of potent drug and used for delivery. Paper based microfluidics was used for point-of-care diagnosis for accurate treatment of diseases. In this chapter, we highlight advances of microfluidics devices for number of biological and translational science applications.

Micro/nanofluidic devices for DNA/RNA detection and separation

The development and research have ramped up at a greater speed than ever in the field of diseases diagnosis. Still there is struggle in developing early detection techniques which uses complex biomolecules like RNA, DNA and proteins in order to detect diseases caused by bacteria, viruses or fungi. Until now separation techniques used before detection rely on traditional techniques like electrophoresis etc. which often require centralized services. Although efforts are made in developing devices that is capable enough on carrying out separation and detection based on microfluidic (MF) and nanofluidic (NF) or lab on chip. Hence, in this chapter, we have discussed about the advancement, limitations and future steps that needs to be taken to flourish the field of NF and MF for the detection and separation of nucleic acid.

Disposable paper-based PET fluorescence probe linked with calix[4]arene for lithium and phosphate ion detection

As a part of our ongoing research, we have synthesized a new fluorescence probe, p-C4A, based on a calix[4]arene substituted with 4-aminoquinoline moieties with amide linkages for lithium and phosphate ions.

Low vitamin D levels and prognosis in a COVID-19 pediatric population: a systematic review

We aim to study the relationship between vitamin D level, risk and severity of Coronavirus disease of 2019 (COVID-19) infection in pediatric population through systematic review. We searched PubMed, CINAHL, EMBASE, Cochrane Library and Google Scholar from December 2019 to June 2021 for retrieving articles studying association between vitamin D deficiencies with COVID-19. Qualitative details were synthesized in evidence table and quantitative data was used for deriving pooled estimate through meta-analysis. After initial search of 2261 articles, eight eligible studies (two reviews) were included in the systematic review. Meta-analysis of the quantitative data (six studies) showed pooled prevalence of vitamin D deficiency as 45.91% (95% CI: 25.148-67.450). In infected pediatric patients, low levels of vitamin D increased the risk of severe disease (odds ratio-5.5; 95% CI: 1.560-19.515; P = 0.008). It was also found that children and adolescents having vitamin D deficiency had greater risk of COVID infection as compared to patients with normal vitamin D levels. Improvement in disease severity with vitamin D supplementation was also noted. The systematic review showed that almost half of the pediatric COVID patients suffer from vitamin D deficiency. It is also clear that the low level of vitamin D is associated with greater risk of infection and poorer outcome in pediatrics.

Rescan Time Delays in Ischemic Stroke Imaging: A Retrospective Observation and Analysis of Causes and Clinical Impact

BACKGROUND AND PURPOSE

Delays to reperfusion negatively impact outcomes of patients with ischemic stroke, yet current guidelines recommend selective sequential imaging for thrombectomy candidates. We aimed to quantify and analyze time delays associated with rescanning in sequential acute stroke imaging.

MATERIALS AND METHODS

This was a retrospective cohort study of consecutive patients with acute ischemic stroke who underwent imaging for treatment decision-making from January 1, 2017, to June 30, 2020. Rescan time delay was defined as ≥10-minute difference between initial NCCT and CTA ± CTP. Mean rescan time delays in comprehensive and primary stroke centers were compared. Bivariate and multivariable regression analyses assessed clinical and imaging factors associated with rescanning time delays and early outcomes.

RESULTS

A total of 588 patients with acute ischemic were included in statistical analyses. Rescanning occurred in 27.9% (164/588 patients), with a mean time delay of 53.7 (SD, 43.4) minutes. For patients presenting at primary compared with comprehensive stroke centers, rescan time delays were more common (59.6% versus 11.8%, P < .001), with longer delays (65.4 [SD, 45.4] minutes versus 23.6 [SD, 14.0] minutes, P < .001). Independent predictors of rescan time delays included primary stroke center presentation, intravenous thrombolysis administration, black race, admission NIHSS ≥10, baseline independent ambulation, and onset-to-comprehensive stroke center arrival in ≥6 hours. Protocols for early simultaneous comprehensive CT (NCCT + CTA + CTP) were associated with lower odds of time delays (OR = 0.34; 95% CI, 0.21-0.55). Rescanning was associated with lower odds of home discharge (OR = 0.53; 95% CI, 0.30-0.95).

CONCLUSIONS

A sequential approach to CT-based imaging may be significantly associated with prolonged acute stroke evaluations. Adoption of early simultaneous comprehensive CT could minimize treatment delays and improve outcomes.

Emerging diagnostic tools for detection of COVID-19 and perspective

The COVID-19 caused by a novel coronavirus, named Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2) has taken a great toll of life affecting lakhs of people around the globe. It was detected initially in Wuhan, China and has spread rapidly to more than 208 countries to date. A range of molecular and immunoassay-based techniques ranging from central laboratory testing to point-of-care tests is urgently needed for the diagnosis and management of COVID-19 patients. Intensive research is going on for the rapid and highly sensitive detection of COVID 19 using varied approach. Hence, this review will focus on the structure of SARS-CoV-2 and recent progress of different detection tool for the detection of COVID-19. This review will also stimulate academics and researcher to update their current technology. Additionally, we also state about the future revolving around the detection of the novel coronavirus. Lately, the way ahead for better management are also put forward.

Turn on fluorescence strip based sensor for recognition of Sr2+ and CN- via lowerrim substituted calix[4]arene and its computational investigation

Fluorescence sensor L designed around a calix[4]arene scaffold, bearing two fluorogenic aminoquinoline moities, has been synthesized. It is found to be selective and sensitive towards Sr²⁺ and CN^- over a wide range of cations and anions in a spectrofluorometric study in acetonitrile. The ion-binding property of L was monitored by fluorescence spectroscopy, UV-vis spectroscopy, ESI-MS, ¹H NMR, FT-IR investigation and PXRD study. The host L shows a minimum detection limit which is 1.36 nM for Sr²⁺ and 1.23 nM for CN^- having concentration range 5-120 nM and 5-115 nM respectively. The calculated binding constants for L:Sr²⁺ and L: CN^- are respectively 8.859 × 10⁸ M^-1 and 8.574 × 10⁸ M^-1. Our host L has been utilised in formation of a user-friendly, affordable, and disposable paper-based analytical device (PAD) for rapid chemical screening of Sr²⁺ and CN^- ion via single strip. Moreover, the optimization of probe L has also been done by the MOPAC-2016 software package using NM7 popular method resulting -21.71 kcals/mol heat of formation and also determined the HOMO-LUMO energy band gap for L, L:Sr²⁺ and L: CN^-. Further, molecular docking score has been calculated using HEX software. The applicability of our probe in real samples containing Sr²⁺ and CN^- has also been checked by emission study with 94-99% recovery.

Luminescent behavior of pyrene-allied calix[4]arene for the highly pH-selective recognition and determination of Zn2+, Hg2+ and I−via the CHEF-PET mechanism: computational experiment and paper-based device

In this article, for the first time, we have reported a novel CHEF-PET fluorescence sensor L based on calix[4]arene containing four pyrene groups as binding sites, which is highly selective and sensitive towards Zn²⁺, Hg²⁺ and I⁻.

Single-step fluorescence recognition of As3+, Nd3+ and Br− using pyrene-linked calix[4]arene: application to real samples, computational modelling and paper-based device

A new fluorescence sensor has been synthesized for its selective recognition of As³⁺ (11.53 nM), Nd³⁺ (0.65 nM) and Br⁻ (11.25 nM).

Multifunctional Silver-Cellulose Nanocomposite as a Promising Plasmonic Sensing Platform

Cellulose paper based multifunctional nanoplatform shows great promise towards molecular sensing and diagnostics application due to their sustainability, biocompatibility, affordability, environmental appeal and broad chemical modification capabilities. Herein, we have effectively synthesized plasmonic silver-cellulose nanocomposite (SCN) using complete green and in situ approach using the hydroxyl groups of cellulose paper acting as the reducing agent and stabilizing agent. The fabricated SCN were investigated and characterized by SEM, UV-Vis, DLS, PXRD and EDX. The important influencing parameters such as temperature and pH were optimized during the fabrication of SCN. Besides, this SCN functionalized with 3-aminopropyltriethoxysilane and has been exploited for monitoring of fluoride ion from water samples with distinguishing F- from a wide range of environmental prevalent ions. These remarkable properties of SCN have been used as rapid, portable test panel which could be simple, lightweight and disposable.

Synthesis of biocompatible iron oxide nanoparticles as a drug delivery vehicle

Over the last decade, there has been growing interest in developing novel nanoparticles (NPs) for biomedical applications. A safe-by-design approach was used in this study to synthesize biocompatible iron oxide NPs. The size of the particles obtained was ~100 nm. Although these NPs were significantly (P<0.05) internalized in MCF-7 (human breast adenocarcinoma cell line) cells, no adverse effect was observed in the cells as assessed by cytotoxicity assays (neutral red uptake and 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) and cell cycle analysis. Our data demonstrate the potential of iron oxide NPs as a biocompatible carrier for targeted drug delivery.

Curcumin Ag nanoconjugates for improved therapeutic effects in cancer

Curcumin has a broad spectrum of pharmacological activities, one of them is anticancer activity that is mediated through multiple mechanisms. The major disadvantage associated with the use of curcumin is its low bioavailability due to its poor aqueous solubility. Nanoformulations of curcumin provide an effective solution for this problem. In this study, we have synthesized curcumin Ag nanoconjugates and evaluated their anticancer potential.

Effects of Radiation Exposure on the Cost-Effectiveness of CT Angiography and Perfusion Imaging in Aneurysmal Subarachnoid Hemorrhage

BACKGROUND AND PURPOSE

CT angiography and perfusion imaging is an important prognostic tool in the management of patients with aneurysmal subarachnoid hemorrhage. The purpose of this study was to perform a cost-effectiveness analysis of advanced imaging in patients with SAH, incorporating the risks of radiation exposure from CT angiography and CT perfusion imaging.

MATERIALS AND METHODS

The risks of radiation-induced brain cancer and cataracts were incorporated into our established decision model comparing the cost-effectiveness of CT angiography and CT perfusion imaging and transcranial Doppler sonography in SAH. Cancer risk was calculated by using National Cancer Institute methodology. The remaining input probabilities were based on literature data and a cohort at our institution. Outcomes were expected quality-adjusted life years gained, costs, and incremental cost-effectiveness ratios. One-way, 2-way, and probabilistic sensitivity analyses were performed.

RESULTS

CT angiography and CT perfusion imaging were the dominant strategies, resulting in both better health outcomes and lower costs, even when incorporating brain cancer and cataract risks. Our results remained robust in 2-way sensitivity analyses varying the prolonged latency period up to 30 years, with either brain cancer risk up to 50 times higher than the upper 95% CI limit or the probability of cataracts from 0 to 1. Results were consistent for scenarios that considered either symptomatic or asymptomatic patients with SAH. Probabilistic sensitivity analysis confirmed our findings over a broad range of selected input parameters.

CONCLUSIONS

While risks of radiation exposure represent an important consideration, CT angiography and CT perfusion imaging remained the preferred imaging compared with transcranial Doppler sonography in both asymptomatic and symptomatic patients with SAH, with improved health outcomes and lower health care costs, even when modeling a significantly higher risk and shorter latency period for both cataract and brain cancer than that currently known.

DNA assembled metal nanoclusters: synthesis to novel applications

In this review, we have discussed the emergence of promising environmental-benign DNA assembled fluorescent metal nanoclusters and their unique electronic structures, unusual physical and chemical properties.

A unique fluorescence biosensor for selective detection of tryptophan and histidine

A novel photoinduced electron transfer (PET) based substituted calix[4]arene fluoroionophore has been used for the selective recognition of tryptophan (L-Trp) and histidine (L-His) by emission spectroscopy. The detection limit of the synthesized receptor was found to be 0.00826 nM for L-Trp and 0.00158 nM for L-His. Moreover, this probe has been applied for the recognition of L-Trp and L-His from blood serum.

Fluorescent magnesium nanocomplex in a protein scaffold for cell nuclei imaging applications

For the first time, we report a facile strategy for the synthesis of ultra-fine blue-green emitting fluorescent magnesium nanoparticles–protein complex (MgNC) which shows excellent photo stability and also stain cell nuclei with high specificity.

CT angiographic features of symptom-producing plaque in moderate-grade carotid artery stenosis

BACKGROUND AND PURPOSE

Emerging evidence indicates that plaque imaging can improve stroke risk stratification in patients with carotid artery atherosclerosis. We studied the association between soft and hard (calcified) plaque thickness measurements on CTA and symptomatic disease status (ipsilateral stroke or TIA) in patients with moderate-grade carotid artery stenosis.

MATERIALS AND METHODS

We measured soft-plaque and hard-plaque thickness on CTA axial source images in each carotid artery plaque in subjects with NASCET 50%-69% ICA stenosis. We used logistic regression and receiver operating characteristic analyses to assess the strength of the association between thickness measurements and prior stroke or TIA.

RESULTS

Twenty of 72 vessels studied (27.7%) had ischemic symptoms ipsilateral to the side of moderate-grade carotid stenosis. Each 1-mm increase in soft plaque resulted in a 3.7 times greater odds of a prior ipsilateral ischemic event (95% CI, 1.9-7.2). Conversely, for each 1-mm increase in hard plaque, the odds of being symptomatic decreased by approximately 80% (OR, 0.22; 95% CI, 0.10%-0.48%). Receiver operating characteristic analysis showed an area under the curve of 0.88 by using soft-plaque thickness measurements to discriminate between asymptomatic and symptomatic plaques. Sensitivity and specificity were optimized by using a maximum soft-plaque thickness of 2.2 mm, which provided a sensitivity of 85% and a specificity of 83%.

CONCLUSIONS

Simple CTA plaque-thickness measurements might differentiate symptomatic and asymptomatic moderate-grade carotid artery plaque. With further prospective validation, CTA plaque measures could function as an easily implementable tool for risk stratification in carotid artery disease.

Cost-effectiveness of CT angiography and perfusion imaging for delayed cerebral ischemia and vasospasm in aneurysmal subarachnoid hemorrhage

BACKGROUND AND PURPOSE

Delayed cerebral ischemia and vasospasm are significant complications following SAH leading to cerebral infarction, functional disability, and death. In recent years, CTA and CTP have been used to increase the detection of delayed cerebral ischemia and vasospasm. Our aim was to perform comparative-effectiveness and cost-effectiveness analyses evaluating CTA and CTP for delayed cerebral ischemia and vasospasm in aneurysmal SAH from a health care payer perspective.

MATERIALS AND METHODS

We developed a decision model comparing CTA and CTP with transcranial Doppler sonography for detection of vasospasm and delayed cerebral ischemia in SAH. The clinical pathways were based on the "Guidelines for the Management of Aneurysmal Subarachnoid Hemorrhage: A Guideline for Healthcare Professionals from the American Heart Association/American Stroke Association" (2012). Outcome health states represented mortality and morbidity according to functional outcomes. Input probabilities of symptoms and serial test results from CTA and CTP, transcranial Doppler ultrasound, and digital subtraction angiography were directly derived from an SAH cohort by using a multinomial logistic regression model. Expected benefits, measured as quality-adjusted life years, and costs, measured in 2012 US dollars, were calculated for each imaging strategy. Univariable, multivariable, and probabilistic sensitivity analyses were performed to determine the independent and combined effect of input parameter uncertainty.

RESULTS

The transcranial Doppler ultrasound strategy yielded 13.62 quality-adjusted life years at a cost of $154,719. The CTA and CTP strategy generated 13.89 quality-adjusted life years at a cost of $147,097, resulting in a gain of 0.27 quality-adjusted life years and cost savings of $7622 over the transcranial Doppler ultrasound strategy. Univariable and multivariable sensitivity analyses indicated that results were robust to plausible input parameter uncertainty. Probabilistic sensitivity analysis results yielded 96.8% of iterations in the right lower quadrant, representing higher benefits and lower costs.

CONCLUSIONS

Our model results suggest that CTA and CTP are the preferred imaging strategy in SAH, compared with transcranial Doppler ultrasound, leading to improved clinical outcomes and lower health care costs.

Oxygen extraction fraction and stroke risk in patients with carotid stenosis or occlusion: a systematic review and meta-analysis

BACKGROUND AND PURPOSE

Increased oxygen extraction fraction on PET has been considered a risk factor for stroke in patients with carotid stenosis or occlusion, though the strength of this association has recently been questioned. We performed a systematic review and meta-analysis to summarize the association between increased oxygen extraction fraction and ipsilateral stroke risk.

MATERIALS AND METHODS

A comprehensive literature search was performed. We included studies with baseline PET oxygen extraction fraction testing, ipsilateral stroke as the primary outcome, and at least 1 year of follow-up. A meta-analysis was performed by use of a random-effects model.

RESULTS

After screening 2158 studies, 7 studies with 430 total patients with mean 30-month follow-up met inclusion criteria. We found that 6 of 7 studies were amenable to meta-analysis. Although 4 of the 6 studies independently did not reach statistical significance, meta-analysis revealed a significant positive relationship between abnormal oxygen extraction fraction and future ipsilateral stroke, with a pooled OR of 6.04 (95% CI, 2.58-14.12). There was no statistically significant difference in OR in the subgroup analyses according to testing method or disease site.

CONCLUSIONS

Abnormal oxygen extraction fraction remains a powerful predictor of stroke in carotid stenosis or occlusion and is a valuable reference standard to compare and validate MR imaging-based measures of brain oxygen metabolism. However, there is a need for further evaluation of oxygen extraction fraction testing in patients with high-grade but asymptomatic carotid disease.

A smart and rapid colorimetric method for the detection of codeine sulphate, using unmodified gold nanoprobe

Herein, we reported unique optical and electrochemical properties of citrate-stabilized gold nanoparticles (AuNPs) as a probe for smartphone-assisted, on-spot detection of codeine sulphate in toxicological screening with high sensitivity (0.9 μM).

A pyrenyl linked calix[4]arene fluorescence probe for recognition of ferric and phosphate ions

A pyrenyl linked calix[4]arene fluroionophore has been synthesized and used as a ditopic chemosensing ensemble for Fe³⁺ and H₂PO₄⁻ using emission spectra. The detection limit of the synthesized receptor was found to be 0.88 pM for Fe³⁺ and 1.11 pM for H₂PO₄⁻. Moreover, this probe has been applied for recognition of Fe³⁺ in blood serum and H₂PO₄⁻ in waste water.

Intraplaque high-intensity signal on 3D time-of-flight MR angiography is strongly associated with symptomatic carotid artery stenosis

BACKGROUND AND PURPOSE

Intraplaque hemorrhage in carotid artery atherosclerotic plaque has been shown to be a marker of risk, associated with prior and future ischemic events, and has been associated with regions of intraplaque high-intensity signal on 3D-TOF MRA. We assessed the association of intraplaque high-intensity signal determined on 3D-TOF MRA with the incidence of prior ipsilateral stroke or TIA.

MATERIALS AND METHODS

We assessed intraplaque hemorrhage by evaluating for intraplaque high-intensity signal adapting a recently validated technique on 3D-TOF source images in participants with high-grade (≥ 70%) extracranial carotid stenosis. Logistic regression analyses were used to assess the strength of association between the presence of intraplaque high-intensity signal on routine MRA sequences and prior stroke or TIA.

RESULTS

Intraplaque high-intensity signal was present in 22 (41.5%) of 53 carotid arteries studied in 51 patients. Ipsilateral ischemic events occurred in 15 (68.1%) of 22 in the intraplaque high-intensity signal-positive group (10 strokes, 5 TIAs) and in 4 (12.9%) of 31 in the intraplaque high-intensity signal-negative group (3 strokes, 1 TIA). Ischemic events occurred within the 6-month period preceding imaging in 18 (94.7%) of 19 cases. The univariate odds ratio of the association of intraplaque high-intensity signal with any prior ischemic event was 14.5 (95% CI, 3.6-57.6), and the multivariate age- and sex-adjusted odds ratio was 14.2 (95% CI, 3.3-60.5). The association remained present across 1.5 T and 3T magnet field strengths.

CONCLUSIONS

Intraplaque high-intensity signal determined from MRA sequences already in place to measure luminal stenosis is strongly associated with prior ipsilateral ischemic events. Prospective validation of these findings to predict outcome in carotid artery stenosis could provide a valuable and widely accessible stroke risk stratification tool.

A novel calix[4]arene thiol functionalized silver nanoprobe for selective recognition of ferric ion with nanomolar sensitivity via DLS selectivity in human biological fluid

A high concern for human health and safety has motivated dynamic research on the potential impact of transition metal ions and their toxic effects, thus it is very challenging to design transition-metal ion detection devices that are cost-effective, rapid and applicable to the biological milieus. Driven by the need to detect trace amounts of Fe(3+) from blood samples, we report a highly selective and ultrasensitive calix[4]arene modified silver nanoprobe for Fe(3+) recognition at the 9.4 nM level from aqueous solution with excellent discrimination against other heavy metals and biomolecules. The assembly was characterized by TEM (transmission electron microscopy), DLS (dynamic light scattering), UV-Vis, FT-IR, ESI-MS and (1)H NMR spectrometry, which demonstrate the higher binding affinity for Fe(3+). The biosensor has been successfully applied to estimate the ferric ion in human blood serum as well as in human hemoglobin.