Precise Method Research Articles

YOLOv5-T: A precise real-time detection method for maize tassels based on UAV low altitude remote sensing images

Maize tassels is an important organ of maize plant, and has a very important impact on yield prediction and variety breeding. Therefore, realizing the efficient and accurate detection of maize tassels in the natural environment is the key to obtain maize phenotypes in large quantities and accurately predict maize yield. This study constructed a dataset of tassels from different growth stages, proposed a YOLOv5-Tassel (YOLOv5-T) maize tassels detection model based on UAV remote sensing platform, combined with attention mechanism, YOLOv5_l network, spatial pyramid pooling structure and multi-scale extraction advantages of Atrous convolution. The experimental results showed that the Average Precision (AP) of the model for maize tassels detection could reach 98.70 %, and the detection speed was 42.2f/s. And the method in this paper had strong robustness to changes in light intensity and maize tassels at different growth stages. It was feasible to use YOLOv5-T to detect large areas of maize tassels in real time, which provided a useful reference for the estimation of maize yield and the selection of maize varieties.

An ensemble-based approach for effective distributed denial of service attack detection in software defined networking

<p>Software defined networking (SDN) is a network framework that aims to redefine network characteristics through the programmability of network components, faster and larger network monitoring, centralized network operation, and effective detection of fraudulent traffic and special malfunctions. However, SDN networks are vulnerable to security threats that can cause complete network failure. To address this issue, in this paper, machine learning techniques are suggested for the swift detection of attacks. Various methods for detecting distributed denial of service (DDoS) attacks are evaluated, and the study identifies the most precise method for categorizing such attacks within a SDN network. The results indicate that the proposed system achieves high accuracy in detecting DDoS attacks, with ensemble learning achieving 99% accuracy. This indicates a remarkable improvement percentage in comparison to the approaches of decision tree (DT), k-nearest neighbors (KNN), and support vector machine (SVM).</p>

Implementing Improved YOLOv5s for Immediate Identification of Helmetless Forklift Drivers

Implementing Improved YOLOv5s for Immediate Identification of Helmetless Forklift Drivers

Decoupling mechanical and chemical effects on energetics of coherent nanoprecipitates with interfacial segregation

Interfacial energetics for coherent interfaces are typically calculated using two key concepts: interfacial energy and coherency strain energy. Although these calculations are well-established in pristine systems, their direct application to doped systems often leads to inaccuracies. This is primarily because foreign solute atoms not only modify interfacial energetics but also introduce additional mechanical and chemical effects within the bulk phases. To address this, our study employs the PSTRESS tag in VASP to simulate equivalent lattice stresses induced by solute atoms without physically incorporating them. This novel approach allows us to isolate the doping energy caused by the solute atoms’ mechanical and chemical effects, thereby enhancing our understanding of the impacts of dopants solely on interfacial energetics. Furthermore, we extend the calculations of interfacial energy and coherency strain energy to doped interfaces, providing a precise and effective evaluation method for both bulk and interfacial energetics in doped systems.

Sulfur Modified Carbon-Based Single-Atom Catalysts for Electrocatalytic Reactions.

Efficient and sustainable energy development is a powerful tool for addressing the energy and environmental crises. Single-atom catalysts (SACs) have received high attention for their extremely high atom utilization efficiency and excellent catalytic activity, and have broad application prospects in energy development and chemical production. M-N4 is an active center model with clear catalytic activity, but its catalytic properties such as catalytic activity, selectivity, and durability need to be further improved. Adjustment of the coordination environment of the central metal by incorporating heteroatoms (e.g., sulfur) is an effective and feasible modification method. This paper describes the precise synthetic methods for introducing sulfur atoms into M-N4 and controlling whether they are directly coordinated with the central metal to form a specific coordination configuration, the application of sulfur-doped carbon-based single-atom catalysts in electrocatalytic reactions such as ORR, CO2RR, HER, OER, and other electrocatalytic reaction are systematically reviewed. Meanwhile, the effect of the tuning of the electronic structure and ligand configuration parameters of the active center due to doped sulfur atoms with the improvement of catalytic performance is introduced by combining different characterization and testing methods. Finally, several opinions on development of sulfur-doped carbon-based SACs are put forward.

Bandgap accuracy and characteristics of fluid-filled periodic pipelines utilizing precise parameters transfer matrix method

The phononic crystal theory provides a novel approach for effectively controlling the bending vibrations in fluid-filled pipelines. This paper innovatively proposes the precise parameters transfer matrix method to investigate the band calculation accuracy and bandgap characteristics of fluid-filled periodic pipelines with various beam types. Firstly, the differential equations for bending vibration of fluid-filled pipelines are established based on deformation and force analysis. The parameters of the system state are precisely represented by the structural form of multiplying the constitutive matrix with the derivative matrix. Combined with Bloch's theorem, the novel precise parameters transfer matrix method for calculating the band structure is proposed. Secondly, the validity of this method is verified through a comparison with finite element simulation results. A detailed analysis is provided regarding the mechanism of bandgap formation and the effect of fluid filling on the band structure. Then, the influence of shear deformation, moment of inertia, and their coupling on the band calculation accuracy for fluid-filled periodic pipelines is studied based on various beam theories. Finally, it delves into the bandgap characteristics of fluid-filled periodic pipelines under different material parameters, structural parameters, and excitation conditions. This research offers valuable insights for the structural design and vibration damping application in fluid-filled periodic pipelines, providing theoretical support for accurately determining their bandgaps.

Measurement Refinements of Ground-Based Radar Interferometry in Bridge Load Test Monitoring: Comprehensive Analysis on a Multi-Span Cable-Stayed Bridge

This paper presents three refinements in ground-based radar interferometer (GB-radar) measurement for bridge load testing: (1) GB-radar phase jumps were detected for the first time on bridge tower displacement monitoring, and a recovery method is presented to obtain the correct unwrapped value; (2) a precise displacement projection method considering target deformation was exploited, and a case study of the Fifth Nanjing Yangtze River Bridge (FNYRB) GB-radar campaign shows that a centimeter-level compensation can be achieved; (3) a post-construction settlement phenomenon was found during the FNYRB static load tests, characterized by 0.31 mm/min, which accumulated up to 25 mm. In addition, the dynamic monitoring capabilities of GB-radar for the bridge tower and girder were verified, highlighting its potential for bridge structural health monitoring (SHM). The insights gained from this study offer valuable recommendations for future GB-radar bridge displacement monitoring.

Molecular cytogenetic screening of sex chromosome abnormalities in young horse populations.

Chromosomal abnormalities occur in the equine population at a rate of approximately 2%. The use of molecular cytogenetic techniques allows a more accurate identification of chromosomal abnormalities, especially those with a low rate of abnormal metaphases, demonstrating that the actual incidence in equine populations is higher. Estimation of the number of carriers of karyotypic abnormalities in a sample from a population of young horses of various breeds, using molecular cytogenetic techniques. Cross-sectional. Venous blood samples were collected from 500 young horses representing 5 breeds (Purebred Arabian, Hucul, Polish primitive horse [Konik], Małopolska, Coldblood, Silesian). Chromosomes and DNA were obtained from blood lymphocytes and evaluated by fluorescence in situ hybridisation (FISH) and PCR, using probes and markers for the sex chromosomes and select autosomes. Nineteen horses, 18 mares and 1 stallion, were diagnosed with different chromosomal abnormalities: 17 cases of mosaic forms of sex chromosome aneuploidies with a very low incidence (0.6%-4.7%), one case of a SRY-negative 64,XY sex reversal mare, and one mare with X-autosome translocation. The percentage of sex chromosomal aberrations was established as 3.8% in the whole population, 6.08% in females and 0.49% in males. Limited sample size, confined to horses from Poland. The rate of sex chromosomal abnormalities we identified was almost double that reported in previous population studies that used classical chromosome staining techniques. FISH allowed the detection of aneuploid cell lines which had a very low incidence. The FISH technique is a faster and more precise method for karyotype examination; however, it is usually focused on only one or two chromosomes while banding karyotyping includes the entire chromosome set.

PRECISION AND RELIABILITY OF NANOPLATE DIGITAL PCR SYSTEM FOR PORK DNA IDENTIFICATION AND QUANTIFICATION

The adulteration and mislabeling of food ingredients, particularly meat products, pose a significant concern for consumers. In order to address this issue, it is crucial to use precise and sensitive methods for species identification, mainly when dealing with samples that contain a limited number of copies of DNA. The primary objective of this study is to design a digital nanoplate polymerase chain reaction (PCR) technique for the purpose of quantifying species identification. The primer used in this study was cytochrome b gene. The results showed that target DNA can be amplified using the digital PCR nanoplate until the lowest sample concentration of 0.0013 ng/µL. This study can be applied to enhance species identification processes in food samples by utilizing digital PCR nanoplates.

Development and validation of high-performance liquid chromatography method for the simultaneous quantification of rivastigmine hydrogen tartrate and asiaticoside co-loaded in niosomes: A Box–Behnken design approach

Rivastigmine hydrogen tartrate (RHT), a reversible cholinesterase inhibitor, is considered as the first-line therapy for mild to moderate Alzheimer’s disease. Asiaticoside (AS), a pentacyclic triterpenoid saponin, is well known as cognitive enhancer due to its antioxidant effect. Based on the hypothesis of their synergistic therapeutic potential, RHT and AS were co-encapsulated in niosomal formulation. A simple, precise, and accurate high-performance liquid chromatography method was developed for simultaneous quantitative analysis. The chromatographic parameters were optimized by Box-Behnken experimental design. The separation was performed on a reversed-phase Phenomenex C18 (150 mm × 4.6 mm, 5 μm) column at 30 °C under the UV detection of 210 nm. The optimized mobile phase consisted of a mixture of 20 mM potassium dihydrogen phosphate buffer (pH 2.6) and acetonitrile (72:28 % v/v) under the isocratic mode at the flow rate of 0.9 mL/min. The developed method was fully validated under the ICH guidelines and could be successfully applied for simultaneous quantitative analysis of RHT and AS in niosomal formulation.

#2646 Precision verification and method comparison of anti-MPO anti-hsPR3 immunoassay on Alegria2 instrument

Abstract Background and Aims Antibodies to myeloperoxidase (anti-MPO) and proteinase 3 (anti-PR3) are recognized as the only clinically relevant antineutrophil cytoplasmic antibodies (ANCA) specificities so far. ANCA testing can be used in different clinical settings, especially in situations that require rapid diagnosis like renal-pulmonary syndrome that require result within 24 hours. The aim of this study was to perform analytical verification of the new automated single test ELISA based method on Alegria2 instrument to test if the reagents and analyser were acceptable for the routine use. Method For precision assessment we tested two concentration levels of commercial control material in triplicate for five days in a row. We used EASI acceptable criteria for precision for anti-MPO as well as for anti-hsPR3. For method comparison we included 50 patients with history or suspicion of vasculitis. Anti-MPO and anti-PR3 were measured using 5 different reagents: Anti-Myeloperoxidase ELISA (IgG) and anti-PR3-hn-hr ELISA (IgG) on Euroimmun Analyzer I-2P (EUROIMMUN AG, Lubeck, Germany), MPO and PR3 II chemiluminiscent immunoassay (CLIA) on IDS iSYS (IDS ISYS, Pouilly en Auxois, France), QUANTA Flash® MPO and QUANTA Flash® PR3 CLIA on BIO-FLASH® (Inova Diagnostics Inc, San Diego, USA), Anti-MPO and anti-PR3 hs on Alegria2 ELISA based method (Orgentec, Mainz, Germany), and Anti-MPO and anti-PR3 ELISA (Orgentec, Mainz, Germany). Results were categorized as positive or negative and we calculated kappa statistics as well as intraclass correlation coefficient. Complete statistical analysis was done using MedCalc statistical software (MedCalc version 14.8.1, Ostend, Belgium). Results Within-laboratory precision (CV%) for anti-MPO for normal and pathological controls were 5.73% and 15.14% respectively. For anti-PR3 hs within-laboratory precision (CV%) for normal and pathological controls were 5.46% and 18.89% respectively. Intraclass correlation coefficient showed excellent degree of consistency in average measures (0.9778 (95% CI: 0.9665-0.9862)) for anti-MPO and good reliability on single ratings (0.8981 (95% CI: 0.8522-0.9344). For anti PR3 intraclass correlation coefficient showed excellent degree of consistency in average measures (0.9257 (95% CI: 0.8873-0.9539)) but only moderate consistency in single ratings (0.7136 (95% CI: 0.6115-0.8053)). Separate Cohen`s kappa testing revealed almost perfect agreement for most reagent combination for anti- MPO (kappa from 0.825 to 0.958). For anti-PR3 we found moderate agreement between QUANTA Flash® PR3 and PR3 II IDS iSYS (kappa 0.520) but mostly substantial agreement (kappa from 0.629 to 0.865). We also found almost perfect agreement between anti-PR3 hs on Alegria2 and QUANTA Flash® PR3 (kappa = 0.901). Conclusion Our results showed a rather small relative variability and met the precision criteria defined by EASI initiative. Satisfactory agreement between methods is very reassuring but due to the lack of standardisation in autoimmune diagnostics imposes that information about methodological differences must be clearly stated on laboratory report. According to our results the new method for anti-MPO and anti-PR3 proved to be suitable for the routine use.

The Downregulation of MMP23B Facilitates the Suppression of Vitality and Induction of Apoptosis in Endometrial Cancer Cells.

Endometrial cancer is a malignant tumor that commonly occurs in the female reproductive system and its incidence is still increasing. The mechanism of the development of endometrial cancer has not yet been fully clarified, so we need to continuously study the relevant mechanisms of endometrial cancer and continue to explore its biomarkers in order to discover more precise and effective treatment methods for endometrial cancer. RT-qPCR (Real-Time quantitative Polymerase Chain Reaction) experiments were used to detect the expression level of MMP23B (Matrix Metalloproteinase 23B) in endometrial cancer cells; the clinical data of the TCGA (The Cancer Genome Atlas) database were downloaded, and gene expression profiles were analyzed to investigate the correlation between MMP23B (Matrix Metalloproteinase 23B) and the survival prognosis of endometrial cancer, and functional enrichment analysis was performed on MMP23B (Matrix Metalloproteinase 23B) related genes. After silencing MMP23B (Matrix Metalloproteinase 23B), CCK8 (Cell Counting Kit-8), RT-qPCR (Real-Time quantitative Polymerase Chain Reaction), scratch assay, and transwell assay were used to detect cell viability, levels of apoptotic factors, migration rate, and invasion number of endometrial cancer, respectively. MMP23B (Matrix Metalloproteinase 23B) was highly expressed in endometrial cancer, which is closely related to a poor survival prognosis for endometrial cancer, and may act on endometrial cancer through apoptosis-related functions. The downregulation of MMP23B (Matrix Metalloproteinase 23B) reduced the cell viability of endometrial cancer cells, upregulated the expression levels of CASP3 (Caspase-3), CASP8 (Caspase-8) and CASP9 (Caspase-9) in cells, and inhibited cell migration and invasion.

Flood Timing and Flood Loss Impact on Effectiveness of Florpyrauxifen-benzyl Coated on Urea in Rice

ABSTRACT Florpyrauxifen-benzyl applications generated complaints and concerns around rice injury and off-target movement to soybean after the commercial launch in 2018. A precise application method for florpyrauxifen-benzyl was imperative for its continued use. Experiments were conducted in 2020 and 2021 to evaluate rice weed control as influenced by preflood application interval and flood loss following florpyrauxifen-benzyl at 30 g ai ha-1 applied as a spray or coated on urea. In the preflood application experiment, coating florpyrauxifen-benzyl on urea and applying it the day of flood establishment, 5, and 10 d prior to flooding (DPTF) resulted in lower yellow nutsedge, broadleaf signalgrass, and barnyardgrass control than when the herbicide was spray at 3 and 5 wk after final treatment (WAFT). Coating florpyrauxifen-benzyl on urea only provided 61 to 63% yellow nutsedge control at 3 and 5 WAFT, which was 35 to 37 percentage points lower than when spray applied at 5 or 10 DPTF. Likewise, rice yields following applications of florpyrauxifen-benzyl coated on urea were 1200 kg ha-1 less than yields following spray applications. Florpyrauxifen-benzyl coated on urea and clomazone provided lower levels of weed control than spraying the herbicide, suggesting an explanation for the yield losses. The timing of flood loss experiment suggested that when florpyrauxifen-benzyl coated on urea at 30 g ai ha-1 was applied preflood and flood was relinquished at 2 hours, 24 hours, and 7 d after flood establishment, hemp sesbania and yellow nutsedge control were not affected. However, loss of floodwater 2 hours after flood establishment resulted in lower barnyardgrass control than when the flood was lost 24 hours and 7 d after flooding. Generally, the period between a herbicide application and flooding completion should be minimized to aid in weed control. These results indicate the importance of maintaining a flood for weed control and nutrient management.

Evaluating Two Sampling Methods for Mycoplasma Bovis Diagnosis in American Bison (Bison Bison).

Mycoplasma bovis is a bacterial pathogen endemic to cattle. In the early 2000s, M. bovis emerged as a cause of respiratory disease in American bison (Bison bison), causing significant morbidity and mortality. Bison herds that experience an outbreak of M. bovis are at higher risk for subsequent outbreaks, suggesting that chronic, subclinical infections can be established. Antemortem testing is therefore crucial to disease management; however, the precise sampling method to maximize detection of M. bovis in bison is unknown. We evaluated two sample types-superficial nasal swabs and deep nasopharyngeal swabs-collected from apparently healthy or symptomatic bison from January 2021 through December 2022. We used real-time PCR to detect M. bovis in 76/938 bison (8.1%) from 11 herds. For bison testing positive on at least one swab type, M. bovis was detected in 63/76 (82.8%) deep nasopharyngeal swabs and 29/73 (38.1%) superficial nasal swabs. Agreement between swabs for positive bison was 21% (n=16, kappa coefficient 0.319). We conclude that deep nasopharyngeal swabbing is more sensitive than superficial nasal swabbing for detection of M. bovis in bison and that low agreement between methods may be related to stage of infection. We further tested pooled samples by PCR and found that pooling of up to five samples can be effective to increase throughput and minimize costs. Management of wild bison relies on the ability to relocate animals to maintain gene flow and healthy populations. Sensitive and specific diagnostic tests are needed to inform decisions and minimize risk of transmission, especially from subclinical carriers. This study provides valuable insight that will inform best practices for M. bovis testing, thereby supporting the conservation of bison as healthy wildlife, which in turn promotes ecological restoration, safeguards cultural practices of Tribal Nations, and upholds the bison as a unique American icon.

Direct Selective Epitaxy of 2D Sb2Te3 onto Monolayer WS2 for Vertical p-n Heterojunction Photodetectors.

Two-dimensional transition metal dichalcogenides (2D-TMDs) possess appropriate bandgaps and interact via van der Waals (vdW) forces between layers, effectively overcoming lattice compatibility challenges inherent in traditional heterojunctions. This property facilitates the creation of heterojunctions with customizable bandgap alignments. However, the prevailing method for creating heterojunctions with 2D-TMDs relies on the low-efficiency technique of mechanical exfoliation. Sb2Te3, recognized as a notable p-type semiconductor, emerges as a versatile component for constructing diverse vertical p-n heterostructures with 2D-TMDs. This study presents the successful large-scale deposition of 2D Sb2Te3 onto inert mica substrates, providing valuable insights into the integration of Sb2Te3 with 2D-TMDs to form heterostructures. Building upon this initial advancement, a precise epitaxial growth method for Sb2Te3 on pre-existing WS2 surfaces on SiO2/Si substrates is achieved through a two-step chemical vapor deposition process, resulting in the formation of Sb2Te3/WS2 heterojunctions. Finally, the development of 2D Sb2Te3/WS2 optoelectronic devices is accomplished, showing rapid response times, with a rise/decay time of 305 μs/503 μs, respectively.

Alpha-1-Acid Glycoprotein Quantification via Spatial Proximity Analyte Reagent Capture Luminescence Assay: Application as Diagnostic and Prognostic Marker in Serum and Effusions of Cats with Feline Infectious Peritonitis Undergoing GS-441524 Therapy

Until recently, the diagnosis of feline infectious peritonitis (FIP) in cats usually led to euthanasia, but recent research has revealed that antiviral drugs, including the nucleoside analog GS-441524, have the potential to effectively cure FIP. Alpha-1-acid glycoprotein (AGP) has been suggested as a diagnostic marker for FIP. However, AGP quantification methods are not easily accessible. This study aimed to establish a Spatial Proximity Analyte Reagent Capture Luminescence (SPARCLTM) assay on the VetBio-1 analyzer to determine the AGP concentrations in feline serum and effusion samples. Linearity was found in serial dilutions between 1:2000 and 1:32,000; the intra-run and inter-run precision was <5% and <15%, respectively; and AGP was stable in serum stored for at least 8 days at room temperature, at 4 °C and at −20 °C. Cats with confirmed FIP had significantly higher serum AGP concentrations (median: 2954 µg/mL (range: 200–5861 µg/mL)) than those with other inflammatory diseases (median: 1734 µg/mL (305–3449 µg/mL)) and clinically healthy cats (median 235 µg/mL (range: 78–616 µg/mL); pKW < 0.0001). The AGP concentrations were significantly higher in the effusions from cats with FIP than in those from diseased cats without FIP (pMWU < 0.0001). The AGP concentrations in the serum of cats with FIP undergoing GS-441524 treatment showed a significant drop within the first seven days of treatment and reached normal levels after ~14 days. In conclusion, the VetBio-1 SPARCLTM assay offers a precise, fast and cost-effective method to measure the AGP concentrations in serum and effusion samples of feline patients. The monitoring of the AGP concentration throughout FIP treatment provides a valuable marker to evaluate the treatment’s effectiveness and identify potential relapses at an early stage.

Spectrophotometric Method Development and Validation for the Estimation of Trelagliptin Succinate in Bulk and Pharmaceutical Dosage Form

A Simple, precise and sensitive ultraviolet spectrophotometric method was developed for the estimation of Trelagliptin succinate in bulk and pharmaceutical dosage form, method was run through LABINDIA UV-Visible spectrophotometer-3200 with solvent of acetonitrile was used. In this method working wavelength was selected at 276 nm. The developed method was validated as per the international conference on harmonization (ICH Q2(R1)) guidelines. The drug was obeying Beer-Lambert’s law revealed good correlation in the concentration range of 10 - 60 µg/ml with correlation coefficient (r2) of 0.9993. The validity of the proposed method was assessed by applying the standard addition technique where the percentage recovery of the added standard was found to be 99.97 % for Trelagliptin succinate. The absorbance was found to be 0.0365 - 0.0506 with %RSD for both inter-day precision & intraday precision. The limit of detection and quantification were calculated and was found to be 0.0563 µg/mL and 0.1689 µg/mL respectively. The developed method was successfully applied to the determination of Trelagliptin in commercially available dosage form with percentage assay of 98.52. The proposed method is recommended for routine analysis of Trelagliptin in bulk and dosage forms in quality control testing laboratories. Since it is rapid, simple, accurate and sensitive.

Time-frequency analysis of nonlinear structures under nonstationary excitation by directly solving structural dynamic equation through absolute displacement

The time-frequency evolution of seismic ground motion energy under strong earthquakes, which can be described by the evolutionary power spectral density (EPSD) matrix, will amplify the most unfavorable responses of members in nonlinear structural systems. However, the existing general finite element software fails to reduce the dimension of the EPSD matrix and then decouple time from frequency in frequency domain analysis. This failure greatly limits the simulation and calculation of multi-dimensional nonlinear structures with multiple degrees of freedom by the stochastic vibration theory. In this study, the pseudo excitation method (PEM), which can direct solve structural dynamic equations using absolute displacement, is used to derive the self-spectral and cross-spectral densities of seismic ground motions in one-dimensional and multi-dimensional cases. In MATLAB, the EPSD matrix is transformed into a four-dimensional uniform modulation excitation matrix independent of the time variable. Nonlinear iteration is conducted and the precise integration method (PIM) is employed through a transient analysis module. Furthermore, a simple one-dimensional example is presented to verify the correctness of the proposed algorithm herein. Finally, as an example, we select important parameters of the coherence model at different supports of a half-through three-span concrete-filled steel tubular (CFST) tied-arch bridge in view of real engineering conditions, and calculate the time-varying power spectrum and variance of the responses of arch ribs, arch feet and the bridge deck system. The results show that the theoretical derivation and the algorithm constructed in this paper can simulate the time-delay effect of the nonlinear structural system. This proves the feasibility of general finite element software in solving and analyzing random responses to multi-dimensional and multi-support non-stationary excitation of nonlinear structures.

Exogenous and Endogenous Dual-Activated Nanoladder for Precise Imaging of Mitochondrial Ferroptosis-Related Inhibition miRNA with Tumor Cell Specificity.

Developing precise tumor cell-specific mitochondrial ferroptosis-related inhibition miRNA imaging methods holds enormous potential for anticancer drug screening and cancer treatment. Nevertheless, traditional amplification methods still tolerated the limited tumor specificity because of the "off-tumor" signal leakage resulting from their "always-active" sensing mode. To overcome this limitation, we herein developed a dual (exogenous 808 nm NIR light and endogenous APE1) activated nanoladder for precise imaging of mitochondrial ferroptosis-related miRNA with tumor cell specificity and improved imaging resolution. Exogenous NIR light-activation can regulate the ferroptosis-related inhibition miRNA imaging signals within mitochondria, and endogenous enzyme-activation can confine signals to tumor cells. Based on this dual activation design, off-tumor signals were greatly reduced and tumor-to-background contrast was enhanced with an improved tumor/normal discrimination ratio, realizing tumor cell-specific precise imaging of mitochondrial ferroptosis-related inhibition miRNA.

Development and Validation of a RP-HPLC Method for the Simultaneous Determination of Silver Sulfadiazine and Sodium Hyaluronate in the Presence of Methyl and Propyl Paraben in a Pharmaceutical Cream for Burns.

A direct and precise isocratic RP-HPLC method for simultaneous determination of silver sulfadiazine (SSD) and sodium hyaluronate (SH) in the presence of methyl (MP) and propyl parabens (PP) was developed and validated. Agilent chromatograph with X-Select C18 column (250 × 4.6mm2, 5μm) was used. Chromatographic separation was achieved using a mobile phase consisting of acetonitrile and 0.05M phosphate buffer (pH5.0 to which added triethyl amine 0.5ml/L), at a ratio 35: 65v/v. Elution was used at flow rate of 1.0mL/min at ambient temperature with UV detection at 205nm. The retention times for SH, SSD, MP and PP were 1.49, 3.3, 6.7 and 19.5min, respectively. The presented chromatographic method was fully validated in accordance with ICH requirements, it was valid over linearity ranges of (0.80-100.00μg/mL) and (3.20-100.00μg/mL) for SSD and SH, respectively. Acceptable precision and accuracy were obtained for concentrations over the standard curve ranges and the sensitivity of the method, as the limits of detection and quantification for each active ingredient was also determined. The validated method was successfully applied for the quantification of SSD and SH in pharmaceutical cream formulation and the mean recovery %±SD were 100.93 ± 0.985 and 100.05 ± 0.668 for SSD and SH; respectively, indicating satisfactory accuracy of the method.