Dual Platforms Research Articles

Developing dual detection platforms for the electrochemical quantification of homocysteine in biological samples

This study presents a novel dual electrochemical sensor developed using simple electropolymerization technique to detect and measure homocysteine (HC). The developed electrode modification was confirmed using FTIR, XRD, and SEM-EDX examinations. The poly(N-phenylanthranilic acid) modification of the glassy carbon electrode (GCE) and Screen-printed electrode (SPE) significantly enhanced the response for HC, surpassing the findings of previous studies. The improvement can be credited to the exceptional catalytic efficiency of the electro-polymer in electro-oxidizing HC. The electrochemical investigations were conducted utilizing analytical methods such as cyclic voltammetry and differential pulse voltammetry, with a 0.1 M phosphate buffer solution employed as the supporting medium. The poly-NPAA/GCE and poly-NPAA/SPE sensor has demonstrated exceptional sensing properties such as excellent selectivity, sensitivity, reproducibility and and repeatability. It is highly effective in identifying and quantifying HC. The exhibited linear range of both poly-NPAA/GCE and poly-NPAA/SPE are the widest, ranging from 1.0 to 2300.0 μM for poly-NPAA/GCE and from 3.0 to 3000.0 μM for poly-NPAA/SPE, making it the most remarkable result ever reported. The detection limit (LOD) of poly-NPAA/GCE was determined to be 0.165 µM while that of poly-NPAA/SPE was obtained as 0.618 µM. Furthermore, real-sample analysis was performed using biological fluids at the advanced sensor. Therefore, the fabricated poly-NPAA/GCE and poly-NPAA/SPE exhibited exceptional electrocatalytic capabilities for HC sensing, rendering it appropriate for continuous monitoring.

Dual colorimetric platforms for direct detection of glyphosate based on Os-Rh nanozyme with peroxidase-like activity

BackgroundTo minimize the impact of pesticide residues in food on human health, it is necessary to enhance their detection. Recently, many nanozyme-based colorimetric methods for pesticides detection have been developed, however, they often required the assistance of natural enzymes, which made the process and result of methods susceptible to the stability and activity of natural enzymes. To overcome these drawbacks, methods for direct detection of pesticides using nanozymes have been developed, and there are few studies in this field currently. Thus, it is of great research and practical significance to develop more nanozymes-based colorimetric methods for direct detection of pesticides. ResultsDual colorimetric platforms based on Os-Rh nanozyme with excellent peroxidase-like activity were constructed for directly detection of glyphosate in this work. Results showed that glyphosate was able to sensitively and selectively inhibit the peroxidase-like activity of Os-Rh nanozyme through hindering the decomposition of H2O2 by Os-Rh nanozyme to produce HO∙. Based on this, the dual colorimetric platforms achieved highly sensitive detection for glyphosate over a wide linear concentration range (50–1000 μg L−1 in solution platform and 200–1000 μg L−1 in paper platform), with the detection limits of 28.37 μg L−1 in solution platform and 400 μg L−1 (naked-eye detection limit)/123.25 μg L−1 (gray scale detection limit) in paper platform, respectively. Moreover, the dual colorimetric platforms possessed satisfactory reliability and accuracy for practical applications, and has been successfully applied to the detection of real samples with the spiked recoveries of 92.78–102.75 % and RSD of 1.17–3.88 %. SignificanceThe dual colorimetric platforms for glyphosate direct detection based on Os-Rh nanozyme developed in this work not only owned considerable practical application potential, but also could provide more inspirations and ideas for the rational design and development of colorimetric sensing methods for the rapid detection of pesticides based on nanozymes.

A study on the cross-platform influence mechanism of physicians’ live streaming behavior on performance

PurposeThe advent of online live streaming platforms (OLSPs) and online health communities (OHCs) has expedited the integration of traditional medical services with Internet new media technology. Since the practice of physicians conducting live streaming is a relatively new phenomenon, the potential cross-platform effects of such physicians’ live streaming have not received adequate attention.Design/methodology/approachThis study collected data from 616 physicians specializing in cardiology, obstetrics and gynecology and neurology between April and November 2022 on Live.Baidu.com and WeDoctor.com. It constructed a panel data set comprising a total of 4,928 observations over an 8-month period and validated the model using empirical analysis with the fixed-effects method.FindingsWe find evidence of cross-platform influence in online healthcare. Physicians’ live streaming behavior (whether live or not and the heat of their streams) on OLSPs positively impacts both their consultation and reputation on OHCs. Additionally, physicians’ ability positively moderates the relationships between live streaming heat and their performance (in terms of consultation volume and reputation) on OHCs. However, ability does not moderate the relationship between physicians’ live streaming status (live or not) and their performance (in terms of consultation and reputation) on OHCs. Furthermore, the attractive appearance of the physicians also significantly moderates the impact in a positive way.Originality/valueThis is one of the pioneering studies on physicians’ live streaming. The study offers vital guidance for physicians and patients utilizing dual platforms and holds significant reference value for platform operators (such as OLSPs and OHCs) aiming to optimize platform operations and for the government in policy formulation and industry regulation.

基于双平台的“线上 线下”混合教学模式的实践研究——以文科数学《微积分》为例

基于双平台的“线上 线下”混合教学模式的实践研究——以文科数学《微积分》为例

Excellent luminescent thermal stability of Dy3+/Sm3+ co-activated multifunctional titanate single-phase phosphors.

Nowadays, the development of phosphors with excellent luminescent thermal stability for various applications has become a research hotspot. Therefore, the Dy3+/Sm3+ co-activated multifunctional NaYTiO4 phosphors with excellent comprehensive performance in the field of non-contact optical measurement and white LED solid-state lighting were reported in this paper, and their crystal structure, elemental composition, optical bandgap and photoluminescence properties were systematically studied. Remarkably, the reason why NaYTiO4:Dy3+,Sm3+ phosphors achieved color-controlled emission from yellow to orange-red and even to white at the excitation wavelength of 363 nm was not based on the energy transfer process from Dy3+ to Sm3+ but on co-excitation. When the temperature reached 475 K, the luminescence intensity of the phosphor still maintained 96.75% of the initial intensity, demonstrating excellent thermal quenching property. Furthermore, the temperature sensing performance was evaluated by FIR technique according to the differential decreasing trend of Dy3+ and Sm3+ emission intensity with increasing temperature. Finally, we also certified the applicability of NaYTiO4:Dy3+,Sm3+ phosphors in white LEDs for indoor health lighting. These results indicate that NaYTiO4:Dy3+,Sm3+ multifunctional phosphors are promising dual functional luminescent platforms that can be used for non-contact optical thermometers and white LED device applications.

Cubosomal functionalized block copolymer platform for dual delivery of linagliptin and empagliflozin: Recent advances in synergistic strategies for maximizing control of high-risk type II diabetes

A well-made chitosan-PVP block copolymer platform was equipped with highly ordered and uniform nano-channels. This highly adhesive block copolymer platform was designed to ensure the efficient co-delivery of two synergistic-acting hypoglycemic drugs. Linagliptin oral bioavailability is 30% due to poor permeability and intestinal degradation. Its pharmacokinetics shows a non-linear profile. Empagliflozin exhibited decreased permeability and decreased solubility in aqueous media between pH 1 and 7.5. Cubosomes were functionalized as a good microdomain to guest and improve the physicochemical characteristics of drug molecules with decreased permeability and solubility. Cubosomes loaded with linagliptin (linagliptin cubosomes (LCs)) and empagliflozin (empagliflozin cubosomes ECs) were separately prepared using the top-down method and optimized by applying 23 factorial design. Optimized cubosomal systems LCs (F3) and ECs (F4) were incorporated into a chitosan-PVP gel to obtain dual cubosome-loaded platforms (LECF) optimized through 22 factorial design. The permeation study from the optimized LECF (C1) ensured enhanced empagliflozin permeation alongside continued efflux for linagliptin, resolving potential risks due to its non-linear plasma profile. The in-vivo study revealed that AUC(0–∞) of linagliptin and empagliflozin was enhanced by 2- and threefold, respectively. Therefore, the chitosan-PVP block copolymer platform buccal application for the co-delivery of linagliptin and empagliflozin could contribute to enhanced clinical effectiveness in treating diabetes.Graphical Graphical abstract showing dual cubosome-loaded platform tested in-vivo using a rabbit model

Dual sorbent coating based magnet-integrated fabric phase sorptive extraction as a front-end to gas chromatography–mass spectrometry for multi-class pesticide determination in water samples

Magnet-integrated fabric phase sorptive extraction (MI-FPSE) is a sample preparation technique that has proved to be a powerful tool for environmental analysis. The fabrication and application of magnet-integrated dual sorbent-based FPSE membrane prepared by combining two different sol-gel sorbent-coated disks of different polarities together with a magnetic bar inserted between the two membranes to allow the stirring, was examined as novel preparation technique that not required samples pretreatments. The dual sorbent-based sample preparation platforms (made up of poly(tetrahydrofuran) and Carbowax 20M) were used for the extraction of seven classes of pesticides from ambient surface water samples prior to their determination by gas chromatography–mass spectrometry. Initially, different single and dual sol-gel sorbent-based MI-FPSE membranes were evaluated in terms of their extraction efficiency. The MI-FPSE with dual sol-gel sorbents were found to be superior to the single-materials MI-FPSE devices in terms of extraction recovery. The main parameters affecting the MI-FPSE extraction protocol (e.g., adsorption time, sample volume, stirring rate, salt addition, eluent type, desorption time and elution volume) were investigated. The selected extraction protocol enabled detection limits in the range between 0.001 and 0.16 ng mL−1. Furthermore, good relative standard deviation values for the intra-day and inter-day repeatability studies were obtained and were lower than 5.9 and 9.9 %, respectively. The proposed method was successfully used for the multi-class analysis of environmental surface water samples.

Metal–organic framework- and graphene quantum dot-incorporated nanofibers as dual stimuli-responsive platforms for day/night antibacterial bio-protection

Development of advanced antibacterial nanomaterials is important to prevent pathogenic microbial contamination and achieve bioprotection. Herein, we developed dual-stimuli-responsive nanoplatforms with efficient antibacterial activity based on electrospun polycaprolactone/hydroxypropyltrimethylammonium chloride chitosan (PQ) nanofiber membranes (NFMs) incorporated with naringenin-loaded zeolitic imidazolate framework-8 (NAR@ZIF-8) and graphene quantum dots (GQDs). These NFM nanoplatforms could simultaneously be used as “smart” pH-responsive controlled-release and photocatalytic systems. NAR was encapsulated in the microporous structure of the ZIF-8 channel, with a loading capacity of 22.57%. NAR@ZIF-8- and GQD-incorporated PQ (PQZG) nanofibers exhibited enhanced thermal stability and mechanical properties. The release kinetics and microstructure of the nanocarriers demonstrated that the acid-sensitive cleavable crystal structure of ZIF-8 resulted in the pH-responsive release of NAR from PQZG NFMs. Moreover, the presence of GQDs significantly enhanced the photoinduced reactive oxygen species (ROS) generation by NFMs. pH-triggered NAR release and photoinduced ROS generation improved the antibacterial efficacy of PQZG NFMs, forming the synergetic chemical-photodynamic strategies of the dual stimuli-responsive nanoplatforms. Additionally, cytotoxicity experiments revealed that the PQZG NFMs were non-toxic and had good biocompatibility. Therefore, the designed composite nanomaterials combined with the two antibacterial strategies can aid in the development of biosafe nanofibrous membranes for antibacterial or multifunctional bio-protection.

The spillover effects of online tourism platforms on sustainable development

AbstractIn recent years, the proliferation of self‐established and third‐party online tourism platforms has impacted the visitor economy and social welfare sustainably. Tourism enterprises face the key decision of whether to join third‐party platforms or sell tourism services/products directly to consumers. Some researchers have addressed issues about online tourism platforms, but none analyse the internal mechanism and operational management, or the impact of the online tourism platform on sustainable economic growth and social welfare. To fill this gap, we establish an analytical model to explore the optimal tourism marketing and operational management of online tourism platforms for non‐profit tourist attractions and for‐profit tourism enterprises, which can help guide the decisions of managers. We construct a game‐theoretical model in which competing tourism attractions can choose only solo or dual online tourism platform promotion. When competition on a third‐party platform is intense, for‐profit tourism enterprises benefit from dual platforms. We further illustrate that with high competition, non‐profit tourist attractions provide higher social welfare when offering tourism products/services on both self‐established and third‐party tourism channels. However, with lower competition, third‐party tourism platforms harm social welfare if the tourism service/product quality is extremely high or low. Under a decentralised structure, we find that related tourism enterprises prefer to follow and collaborate with their tourist attractions' channel selection when competition in the third‐party platform is not fierce. This result indicates that a third‐party tourism platform improves the visitor economy and social welfare if the tourist attraction collaborates with its tourism‐related enterprises through the online tourism platform.

Instructional materials that control cellular activity through synthetic Notch receptors

The field of regenerative engineering relies primarily on the dual technical platforms of cell selection/conditioning and biomaterial fabrication to support directed cell differentiation. As the field has matured, an appreciation for the influence of biomaterials on cell behaviors has resulted in engineered matrices that meet biomechanical and biochemical demands of target pathologies. Yet, despite advances in methods to produce designer matrices, regenerative engineers remain unable to reliably orchestrate behaviors of therapeutic cells in situ. Here, we present a platform named MATRIX whereby cellular responses to biomaterials can be custom defined by combining engineered materials with cells expressing cognate synthetic biology control modules. Such privileged channels of material-to-cell communication can activate synthetic Notch receptors and govern activities as diverse as transcriptome engineering, inflammation attenuation, and pluripotent stem cell differentiation, all in response to materials decorated with otherwise bioinert ligands. Further, we show that engineered cellular behaviors are confined to programmed biomaterial surfaces, highlighting the potential to use this platform to spatially organize cellular responses to bulk, soluble factors. This integrated approach of co-engineering cells and biomaterials for orthogonal interactions opens new avenues for reproducible control of cell-based therapies and tissue replacements.

Dual drug delivery platforms for bone tissue engineering.

The dual delivery platforms used in bone tissue engineering provide supplementary bioactive compounds that include distinct medicines and growth factors thereby aiding enhanced bone regeneration. The delivery of these compounds can be adjusted for a short or prolonged time based on the requirement by altering various parameters of the carrier platform. The platforms thus used are fabricated to mimic the niche of the bone microenvironment, either in the form of porous 3D structures, microspheres, or films. Thus, this review article focuses on the concept of dual drug delivery platform and its importance, classification of various platforms for dual drug delivery specific to bone tissue engineering, and finally highlights the foresight into the future direction of these techniques for better clinical applications.

The Effects Of The Short Foot Exercise On The Knee During Landing

Intrinsic foot muscles play an important role in the stabilization of the foot and assist with pronation of the foot. Excessive eversion, a component of pronation, may carry up the kinetic chain to impact the knee’s frontal plane position, increasing the chance of a knee injury. Runners who go on to sustain injuries have a greater peak knee abduction moment during running than those without injury. Regular short foot exercise (SFE) strengthens the intrinsic foot muscles, which over time could help improve foot posture and mechanics up the kinetic chain. It is unclear if a single bout of SFE can change mechanics or reduce injurious movement patterns. PURPOSE: The purpose of this study was to study the effects of acute bouts of the SFE on knee adduction moments during a drop vertical jump (DVJ) landing. METHODS: Ten participants (6 male; 24.9 ± 1.2 y) were asked to do three DVJs (PRE) from an 18-inch box. They then completed the SFE bilaterally for two sets of 30 repetitions, both seated and standing followed by three DVJs (POST). Kinetic data was sampled at 1000 Hz with dual AMTI force platforms (Newton, MA); and the kinematics were sampled at 100 Hz with 14-camera motion capture system (Qualysis, Sweden). External moments were calculated via standard inverse dynamics using Visual 3D software (C-motion Inc, Rockville, MD). Peak external knee abduction moment (KABD) normalized to body mass was used for analysis. RESULTS: Paired-t tests showed that there was no effect of SFE on the right KABD (PRE: 0.29 ± 0.13 Nm/kg; POST: 0.28 ± 0.14 Nm/kg; p = 0.432; d = 0.26); however, there was trend towards a decrease in the left KABD with a moderate effect size (PRE: 0.30 ± 0.17 Nm/kg; POST: 0.25 ± 0.14 Nm/kg; p = 0.051; d = 0.76). CONCLUSIONS:In a healthy population, the SFE has little to no effect on the KABD. There was a small decrease in the left KABD in these individuals indicating that in a population with poor mechanics, SFE might be an effective intervention.

Modulatory Contribution of Oxygenating Hydrogels and Polyhexamethylene Biguanide on the Antimicrobial Potency of Neutrophil-like Cells.

Neutrophils are a first line of host defense against infection and utilize a series of oxygen-dependent processes to eliminate pathogens. Research suggests that oxygen availability can improve anti-infective mechanisms by promoting the formation of reactive oxygen species. Also, oxygen can synergistically upregulate the antibacterial properties of certain antibiotics against bacteria by altering their metabolism and causing an increase in the antibiotic uptake of bacteria. Therefore, understanding the effects of oxygen availability, as provided via a biomaterial treatment alone or along with potent antibacterial agents, on neutrophil functions can lead us to the development of new anti-inflammatory and anti-infective approaches. However, the study of neutrophil functions in vitro is often limited by their short life span and nonreproducibility, which suggests the need for cell line-based models as a substitute for primary neutrophils. Here, we took advantage of the differentiated human leukemia-60 cell line (HL-60), as an in vitro neutrophil model, to test the effects of local oxygen and antibacterial delivery by fluorinated methacrylamide chitosan (MACF) hydrogels incorporated with polyhexamethylene biguanide (PHMB) antibacterial agent. Considering the natural modes of neutrophil actions to combat bacteria, we studied the impact of our dual functioning oxygenating-antibacterial platforms on neutrophil phagocytosis and antibacterial properties as well as the formation of neutrophil extracellular traps (NETs) and reactive oxygen species (ROS). Our results demonstrated that supplemental oxygen and antibacterial delivery from MACF-PHMB hydrogel platforms upregulated neutrophil antibacterial properties and ROS production. NET formation by neutrophils upon treatment with MACF and PHMB varied when chemical and biological stimuli were used. Overall, this study presents a model to study immune responses in vitro and lays the foundation for future studies to investigate if similar responses also occur in vivo.

College Teaching Innovation from the Perspective of Sustainable Development: The Construction and Twelve-Year Practice of the 2P3E4R System

It is imperative to construct high-level, innovative and challenging courses in the teaching of colleges and universities. It is also of great significance to explore innovative teaching methods for improving students’ learning effect. In this paper, the course “Civil Engineering Construction” of a civil engineering major is taken as a reform example. In this teaching-innovation mode, guided by students’ moral education and students’ achievements, and the course platform is built in order to achieve the education concept of sustainable development and cultivate applied talents who can solve complex problems in civil engineering. In teaching practice, “Dual Platforms”, which combines course teaching platform and virtual simulation platform, is built mainly to expand the learning approaches. The “Three Educations” mode, which combines on-site education, classroom education, and mental health education, is established to improve the comprehensive quality of students. Comprehensive academic evaluation is carried out through “Four Reports”, including an open assignment report, special technical study report, BIM (building information modeling) technical work report, and final comprehensive written test report. Through studying this course, students not only master the knowledge of civil engineering construction, but also acquire knowledge-innovation ability, such as thesis publication, patent writing, discipline competition, and cultivating the craftsman spirit and social responsibility to abide by professional ethics in future work. This teaching innovation mode has been implemented for 12 years and achieved excellent results in cultivating students’ intelligent ability for sustainable development. It has been promoted in 14 courses, and has certain reference significance for engineering-course teaching.

Application of Dual Metabarcoding Platforms for the Meso- and Macrozooplankton Taxa in the Ross Sea.

Meso- and macrozooplankton play crucial roles in the trophic web and the biological carbon pump in the ocean by transferring energy from lower to higher trophic levels and vertically exporting carbon from the surface to the deep ocean and seabed. In this study, zooplankton community structures in the Ross Sea, Antarctica, were analyzed using metabarcoding methods. Both regular barcode (RB) (using a PacBio Sequel system) and mini barcode (MB) (using the Illumina MiSeq platform) methods were utilized. As the result of a combination of the two bioinformatic pipelines used in the RB, 55 reliable haplotypes were obtained from the pooled zooplankton net samples, whereas 183 amplicon sequence variants (ASVs) were isolated from the MB metabarcoding analyses of 14 individual stations. Among these, 39 (70.9%) and 125 (90.6%) showed higher than 99% sequence identity to the database, indicating that there were sufficient reference sequences to employ metabarcoding analysis—except for several taxa, including small-sized copepods, cnidarians, and pneumodermatids. A high degree of shared taxa showed that both metabarcoding analyses were feasible for use in the analysis of zooplankton assemblages in the Ross Sea. However, RB would be more useful for the construction of a reference database due to its relatively high cost, whereas MB would be more economic for ecological surveys due to its relatively low cost (albeit, only if reference sequences were well documented using RB). Zooplankton assemblages were highly diverse in each sample site, presumably due to the narrow covered volumes of the vertical net-towed samples from polynyas in the Ross Sea. As metabarcoding data accumulate, we will gain better insights into zooplankton communities and their ecological implications in the Ross Sea.

Single-leg mechanical performance and inter-leg asymmetries during bilateral countermovement jumps: A comparison of different calculation methods

BackgroundThe possibility to selectively assess the force exerted by each leg during bilateral jumps has allowed sport scientists to explore inter-leg asymmetries, this metric being a rich source of research due to its potential applications to improve sports performance and reduce the risk of injury. The purpose of this study was to explore the reliability and agreement of single-leg mechanical performance and inter-leg asymmetry variables obtained by two procedures of analysis (Synchronous [simultaneous jump detection for both legs] and Asynchronous [specific jump detection for each leg]) during bilateral countermovement jumps (CMJs). MethodDuring a single testing session, 74 participants performed 5 maximal height bilateral CMJs on dual force platforms (Kistler, model 9260AA6, Winterthur, Switzerland), and the 2 trials that differed the least in terms of squat depth and jump height were considered for statistical analyses. The following mechanical variables were calculated separately for each leg using the Synchronous and Asynchronous procedures: mean force, peak force, and propulsive impulse. ResultsThe procedures showed comparable reliability, except for mean force and propulsive impulse of the left leg (higher for the Asynchronous procedure). The agreement between the procedures was very high, while the most reliable mechanical variable was mean force (CV≈2.9%, ICC≈0.98), followed by peak force (CV≈4.4%, ICC≈0.96) and propulsive impulse (CV≈6.4%, ICC≈0.91). Reliability of inter-leg asymmetries was greater using mean and peak force (ICC range=0.74–0.82) than using propulsive impulse (ICC range = 0.65–0.66). SignificanceBoth Synchronous and Asynchronous procedures can be used to evaluate single-leg mechanical performance (mean force, peak force, and propulsive impulse) and asymmetries, whereas mean force should be used to evaluate single-leg mechanical performance and mean or peak force to assess asymmetries.

The Test-Retest Reliability of Bilateral and Unilateral Force Plate-Derived Parameters of the Countermovement Push-Up in Elite Boxers.

Maximal power describes the ability to immediately produce power with the maximal velocity at the point of release, impact, and/or take off-the greater an athlete's ability to produce maximal power, the greater the improvement of athletic performance. In reference to boxing performance, regular consistent production of high muscular power during punching is considered an essential prerequisite. Despite the importance of upper limb power to athletic performance, presently, there is no gold standard test for upper limb force development performance. To investigate the test-retest reliability of the force plate-derived measures of countermovement push-up in elite boxers. Test-retest design. High Performance Olympic Training Center. Eighteen elite Olympic boxers (age = 23 [3]y; height = 1.68 [0.39]m; body mass = 70.0 [17]kg). Participants performed 5 repetitions of countermovement push-up trials on FD4000 Forcedeck dual force platforms on 2 separate test occasions 7days apart. Peak force, mean force, flight time, rate of force development, impulse, and vertical stiffness of the bilateral and unilateral limbs from the force-time curve. No significant differences between the 2 trial occasions for any of the derived bilateral or unilateral performance measures. Intraclass correlation coefficients indicated moderate to high reliability for performance parameters (intraclass correlation coefficients = .68-.98) and low coefficient of variation (3%-10%) apart from vertical stiffness (coefficient of variation = 16.5%-25%). Mean force demonstrated the greatest reliability (coefficient of variation = 3%). In contrast, no significant differences (P < .001) were noted between left and right limbs (P = .005-.791), or between orthodox or southpaw boxing styles (P = .19-.95). Force platform-derived kinetic bilateral and unilateral parameters of countermovement push-up are reliable measures of upper limb power performance in elite-level boxers; results suggest unilateral differences within the bilateral condition are not the norm for an elite boxing cohort.

Simultaneous detection of dual food adulterants using graphene oxide and gold nanoparticle based surface enhanced Raman scattering duplex DNA biosensor

Development of a facile, fast, sensitive and multiplex DNA detection for the quantitative verification of food adulterant is of high significance these days. RT-PCR, and nanoparticle based fluorescence and electrochemical detection techniques have been successfully used in clinical medicine. However, requirements of pre-conditioning steps and fluorescence dye labeling in RT-PCR, inherent photobleaching and overlapping spectra of fluorescent probe in fluorescent assay, are the few drawbacks that urge to find a suitable alternative. Surface-enhanced Raman scattering (SERS) provides molecule specific fingerprint spectra, could be a strategic to resolve the limitations. Here, we report a SERS based duplex DNA detection strategy for simultaneous and quantitative detection of a meat adulterant (pork) and an endangered species – Malayan Box Turtle (MBT). In the biosensing strategy, SERS active dual platforms – graphene oxide-gold nanoparticles (GO-AuNPs) and AuNPs, and uniquely designed Raman tag intercalated short-length signal probe (SP) sequences are used. The sensing principle relies on the covalent linking of SP sequences functionalized AuNPs and capture probe (CP) functionalized GO-AuNPs via hybridization with corresponding target DNA. Coupling of multi-component platforms contributes in huge SERS signal enhancement due to electromagnetic and charge transfer mechanism. The biosensor showed an improved sensitivity in simultaneous detection of both adulterants with limit of detection (LOD) is 1 × 10−14 M. Moreover, efficiency of SERS biosensor was validated by the DNA extracted from real samples with a LOD of 1 × 10-13 M. Furthermore, the biosensing approach showed excellent sequence specificity in discriminating DNA sequences of five non-target species and specificity towards single nucleotide differentiation.

RGD Peptide‐Drug Conjugates as Effective Dual Targeting Platforms: Recent Advances

AbstractIn recent years, targeted therapies have raised increasing interest as effective strategies to improve therapeutic efficiency, reduce the impact of adverse side effects, and overcome drug resistance, particularly in the field of cancer chemotherapeutics. Many examples of RGD (Arg‐Gly‐Asp) peptide‐drug conjugates (PDCs) have been proposed as targeted drug delivery systems. These molecular hybrids embody high affinity ligands targeting disease signatures (overexpressed integrin receptors or specific integrin‐related pathways within diseased cells/tissues) connected to recognized therapeutic units by means of carefully designed linker‐spacer combinations, to ultimately control stability, physico‐chemical properties, timing, and localization of drug release. This account has collected and critically surveyed relevant contributions from the period of 2015 to the present day, wishing to provide a window open on new synthesis strategies facing the challenging issues of site‐selective drug delivery and dual drug targeting.

Constructing Customized Multimodal Phantoms Through 3D Printing: A Preliminary Evaluation

Purpose: To develop a method for constructing customizable, multimodal quality control (QC) imaging phantoms based on 3D printing technology.Materials and Methods: Four phantoms were designed and constructed through 3D printing technology using three unique printing materials. Physical parameters of the 3D printed materials were evaluated, including density, shore hardness, porosity, deformation temperature, computed tomography (CT) number, absorption coefficient, and printing accuracy. Imaging performance of the phantoms was studied using MRI, CT, PET/MR, and PET/CT, and compared with conventional/commercial phantoms. Imaging assessments included high contrast resolution, low contrast resolution, uniformity, deformation, SNR, slice accuracy/slice thickness, location accuracy/laser alignment, CT number, relaxation time, and registration.Results: All three printing materials have a shore hardness of 90. The physical densities of these materials are 1.15 g/cm3, 0.76 g/cm3, and 1.27 g/cm3, respectively. The porosities are 9.09, 6.81, and 18.56%, respectively. The threshold temperature of deformation for the three materials is &amp;gt;105°C, which is higher than that of PMMA and silica gel. Imaging scans of the constructed phantoms for single modality scanners (MRI and CT) and dual-modality scanners (PET/MRI and PET/CT) were compared with those of the commercial phantoms. The standard deviation of the HU value uniformity test was &amp;lt;3 HU for CT scans.Conclusion: 3D printed medical imaging phantoms allow for rapid, customized phantom fabrication for clinical situations across single and dual modality imaging platforms. Further imaging parameter analysis is underway to provide more quantitative evaluation of the proposed phantoms.