Size Deviation Research Articles

How Many Participants Are Needed? Strategies for Calculating Sample Size in Nutrition Research.

Sample size estimation is a critical aspect of nutrition research methodology, yet it remains frequently overlooked, leading to underpowered studies and potentially inaccurate conclusions. This review addresses this gap by providing comprehensive guidance on how to calculate sample size in nutrition research. Emphasizing the importance of an a priori sample size calculation, the review outlines the key considerations, including the desired levels of significance and power, effect size estimation, and standard deviation assessment. Formulas for determining sample size for various comparisons, including two proportions, two means, three or more groups, and unevenly sized groups, are provided, along with strategies for addressing loss to follow-up. Hypothetical examples illustrate these formulas' application across different research scenarios, highlighting their practical value in ensuring study robustness. Additionally, the review discusses common pitfalls in sample size estimation, such as misjudging effect size or standard deviation, and emphasizes the need for transparent reporting of sample size calculations to enable accurate interpretation of study findings. This article is a resource for nutrition researchers, offering guidance on conducting appropriate sample size calculations to bolster methodological rigor and study reliability. By embracing the principles outlined herein, researchers can elevate the quality of nutrition research.

Systematic Review and Meta-Analysis in Randomized Controlled Trials of Anti-Hypertensive Drugs and the Risk of Cancer

This paper evaluates the potential carcinogenicity of anti-hypertensive medications by performing a meta-analysis on the risk of cancer associated with their use. The analysis incorporated data from 12 studies, encompassing a total of 16,711,997 observations, and focused on randomized controlled trials of anti-hypertensive drugs. The primary objective was to compare the cancer risk across different classes of these medications while considering their blood pressure-lowering effects. The meta-analysis employed a random-effects model to synthesize the results. The mean effect size was found to be 1.178, with a 95% confidence interval ranging from 1.027 to 1.351. A Z-test conducted to test the null hypothesis that the mean effect size equals 1 yielded a Z-value of 2.343 and a p-value of less than 0.019, leading to the rejection of the null hypothesis. This indicates a statistically significant association between the use of anti-hypertensive drugs and an increased risk of cancer. The heterogeneity among the included studies was significant, as evidenced by a Q-statistic of 85.118 with 11 degrees of freedom and a p-value of less than 0.001. The I-squared statistic was 87%, suggesting that 87% of the variance in observed effects was due to differences in true effects rather than sampling error. The tau-squared value, representing the variance of true effect sizes, was 0.040 in log units, while tau, the standard deviation of true effect sizes, was 0.201 in log units. Assuming a normal distribution of true effects, the prediction interval for the true effect size was estimated to be between 0.733 and 1.894, meaning that the true effect size in 95% of all studies would fall within this range. Overall, the findings suggest a potential risk of cancer associated with anti-hypertensive drugs, which warrants careful consideration when weighing their benefits and risks. The computations for the analysis were conducted using Comprehensive Meta-Analysis.

Interdiffusion Induced Changes in the Absorption Spectra of III-V Quantum Dot Systems

III-V Semiconductor quantum dots (QDs) grown with growth interruption technique do not have uniform group III composition inside the dot. Modelling such as-grown structures requires in-depth knowledge of the composition and potential well profile. In this work, we have developed a three-dimensional analytical model which incorporates strain, as well as the variation of group III composition profile in both lateral and vertical directions inside an as-grown QD in order to quantify the effect of dot size variation on the interband optical absorption spectra of as-grown QD systems. Earlier reports on this subject considered the variation of either the dot height or base to account for the size deviation, which may not be sufficient enough to predict the dot size distribution in realistic systems, where all dimensions are likely to suffer from deviation. Keeping this in mind, Gaussian distribution of dot volume has been adopted here to consider the variations of height and base of QDs in a cumulative way. In our study, we considered InGaAs/GaAs and InGaN/GaN QD systems. The non-uniform distribution of indium inside the as-grown dot leads to a non-rectangular potential well profile, which eventually transforms into a rectangular one after annealing. Through the proposed model, we have investigated the effect of inhomogeneous indium composition and dot size variation on the optical absorption spectra of InGaAs/GaAs and InGaN/GaN as-grown QD systems through Gaussian distribution of dot volume. We have also discussed the effect of size deviation on the full width at half maxima (FWHM) of both as-grown and annealed QD systems. Emphasis has been given to the changes in the conduction and valence band potential profiles due to changes in the morphology inside the dot leading to subsequent changes in the energy levels caused by composition uniformity due to annealing and interdiffusion, thus modifying the nature of absorption spectra.

Two-material structure non-probabilistic reliability-based topology optimization against geometric imperfections with bounded field model

In additive manufacturing processes for multi-material structures, geometric uncertainties such as boundary or interface size deviation inevitably occur in the structure because of processing errors and various other reasons; these uncertainties induce performance fluctuations and affect the reliability of the structure. Considering the limited number of samples in practical engineering projects, a novel method of two-material structure non-probabilistic reliability-based topology optimization (TNRBTO) against geometric uncertainty is proposed to improve structure reliability under conditions in which the geometric uncertainty is characterized by an uncertainty threshold field function and further described by a non-probabilistic bounded field model. TNRBTO is a nested optimization model in which the inner-loop is used for reliability evaluation and the outer loop is used to determine the optimal two-material topology via the material-field series-expansion (MFSE) topology optimization method. The sensitivity information for the TNRBTO model is obtained via adjoint sensitivity analysis, and a gradient-based optimization algorithm based on the method of moving asymptotes (MMA) is used to solve the optimization problem. Numerical examples verified the effectiveness of the TNRBTO model against the geometric uncertainty that exist in two-material structures with bounded field model.

Relationship of Iron Deficiency, Anemia and Combination of Iron Deficiency With Anemia With Severity of Manifestations of Chronic Heart Failure. Additional Analysis of the Study "Prevalence of Iron Deficiency in Patients With Chronic Heart Failure in the Russian Federation (J-CHF-RF)".

Aim To evaluate the role of iron deficiency (ID) identified by various criteria, anemia, and the combination of ID and anemia in determining the severity of the clinical course of chronic heart failure (CHF) in a retrospective analysis of data from 498 patients who participated in the ID-CHF-RF Russian multicenter program.Material and methods ID was diagnosed by the following three criteria established by the European Society of Cardiology (ESC) and the Russian Society of Cardiology (RSC): 1) ferritin concentration <100 μg/l or ferritin concentration 100-299 μg/l in combination with a decreased transferrin saturation (TS) <20%; 2) ID criteria that showed a high sensitivity and specificity when compared with bone marrow morphology (BMM): TS ≤19.8% or serum iron (SI) ≤13 μmol/l; and 3) a composite index including a ferritin concentration <100 μg/l in combination with TS <20% and SI ≤13 μmol/l. The presence of anemia was defined as a hemoglobin concentration of less than 12.0 g/dl in women and less than 13.0 g/dl in men according to the criteria of the World Health Organization.Results Concomitant anemia was detected in 40.3% of patients with CHF; in 85.1% of cases, anemia was combined with the SI concentration below normal. CHF patients with concomitant anemia were significantly older and had low levels of not only red blood cells and hemoglobin but also all parameters of iron metabolism, i.e., SI, ferritin concentration, and TS. The mean deviation of the red blood cell size, that characterizes the degree of anisocytosis, was significantly increased in patients with anemia, especially with a low SI. These patients had a higher CHF functional class, elevated levels of N-terminal fragment of pro-brain natriuretic peptide (NT-proBNP) and walked a shorter distance in the 6-minute walk test, which reflects significantly more severe manifestations of CHF with concomitant anemia, particularly in combination with a low SI. The incidence of ID was 83.1% (including 23.3% in combination with anemia) according to the ESC/RSC criteria; 74.5% (including 43.3% with anemia) according to the BMM criteria; and 51.6% (including 51.7% with anemia) according to the composite index, which seems to be stricter compared to the first two criteria. Regardless of the assessment method (by total weighted average data), in ID combined with anemia, not only the hemoglobin concentration was significantly reduced but all three analyzed parameters of iron metabolism were also significantly reduced (SI 9.0 μmol/l vs. 10.4 μmol/l; ferritin 41 μg/l vs. 59 μg/l; TS 8.5% vs. 12.9%) compared to ID without anemia, respectively. The CHF severity and the NT-proBNP concentration were also maximum for the combination of ID and anemia, in contrast to ID without anemia, regardless of the ID criterion used. A more accurate comparison of the methods for determining ID in CHF in the context of their prognostic value will be obtained by analyzing the data of a two-year follow-up of patients in this study, which will be the subject of the next article.Conclusion This analysis suggests that the presence of concomitant ID without anemia or anemia without ID moderately affects the severity of clinical manifestations of CHF and may be rather markers than factors determining the course of the disease, and in this case, does not require special correction with iron medications. And only ID anemia (a combination of ID with anemia) in patients with CHF can be considered a condition requiring special correction (for example, with intravenous medication) in addition to optimal therapy for CHF. This conclusion does not change depending on the used criteria for ID and requires verification in new RCTs.

Prevalence of developmental dental hard-tissue anomalies among adolescents in southeastern Nigerian rural communities

Background and objectives: Dental anomalies are significant deviation in the normal size, structure, number, root formation or shape of a tooth. It can affect primary and permanent dentition. The aim of the present study was to determine the prevalence of developmental dental hard tissue anomalies in the permanent dentition of adolescents in two southeastern Nigerian rural communities. Materials and methods: This cross-sectional descriptive study was conducted among school children aged 12-13 years attending two public secondary schools. The schools were located in Nkanu-West and Udi Local Government areas in Enugu state. Oral examination for the presence or absence of developmental dental hard tissue anomalies was performed by a single examiner. Statistical analysis was done using SPSS Version 25. Results: A total of 61 (44.9%) males and 75(55.1%) females participated in the study. The age range of the children was 12 to 13 years with mean age of 12.49 ± 0.50 years. The prevalence of developmental dental hard tissue anomalies was 2.2%. Developmental dental hard tissue anomalies were seen only in females, higher among 13-year-old school children and school children from middle socioeconomic status. Enamel hypoplasia was seen more than peg shaped lateral incisor. There was no statistically significant association with sex (p = 0.25), age (p = 0.61), socioeconomic status (p= 0.25) and developmental dental hard tissue anomalies. Conclusion: The prevalence of developmental dental hard tissue anomalies was low in this study. Developmental dental hard tissue anomalies can affect aesthetics and quality of life. A visit to dental clinic for clinical assessment, preventive interventions and management is recommended. January 2025; Vol. 19(1):002. DOI: https://doi.org/10.55010/imcjms.19.002 *Correspondence: Obehi. O Osadolor, Department of Child Dental Health, University of Nigeria Teaching Hospital, Ituku- ozalla, Enugu State. Nigeria. E-mail: osadolorobehi@yahoo.com; © 2025 The Author(s). This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0).

Nuclear pleomorphism in canine cutaneous mast cell tumors: Comparison of reproducibility and prognostic relevance between estimates, manual morphometry, and algorithmic morphometry.

Variation in nuclear size and shape is an important criterion of malignancy for many tumor types; however, categorical estimates by pathologists have poor reproducibility. Measurements of nuclear characteristics can improve reproducibility, but current manual methods are time-consuming. The aim of this study was to explore the limitations of estimates and develop alternative morphometric solutions for canine cutaneous mast cell tumors (ccMCTs). We assessed the following nuclear evaluation methods for accuracy, reproducibility, and prognostic utility: (1) anisokaryosis estimates by 11 pathologists; (2) gold standard manual morphometry of at least 100 nuclei; (3) practicable manual morphometry with stratified sampling of 12 nuclei by 9 pathologists; and (4) automated morphometry using deep learning-based segmentation. The study included 96 ccMCTs with available outcome information. Inter-rater reproducibility of anisokaryosis estimates was low (k = 0.226), whereas it was good (intraclass correlation = 0.654) for practicable morphometry of the standard deviation (SD) of nuclear size. As compared with gold standard manual morphometry (area under the ROC curve [AUC] = 0.839, 95% confidence interval [CI] = 0.701-0.977), the prognostic value (tumor-specific survival) of SDs of nuclear area for practicable manual morphometry and automated morphometry were high with an AUC of 0.868 (95% CI = 0.737-0.991) and 0.943 (95% CI = 0.889-0.996), respectively. This study supports the use of manual morphometry with stratified sampling of 12 nuclei and algorithmic morphometry to overcome the poor reproducibility of estimates. Further studies are needed to validate our findings, determine inter-algorithmic reproducibility and algorithmic robustness, and explore tumor heterogeneity of nuclear features in entire tumor sections.

Swarm manipulation: An efficient and accurate technique for multi-object manipulation in virtual reality

The theory of swarm control shows promise for controlling multiple objects, however, scalability is hindered by cost constraints, such as hardware and infrastructure. Virtual Reality (VR) can overcome these limitations, but research on swarm interaction in VR is limited. This paper introduces a novel swarm manipulation technique and compares it with two baseline techniques: Virtual Hand and Controller (ray-casting). We evaluated these techniques in a user study (N = 12) in three tasks (selection, rotation, and resizing) across five conditions. Our results indicate that swarm manipulation yielded superior performance, with significantly faster speeds in most conditions across the three tasks. It notably reduced resizing size deviations but introduced a trade-off between speed and accuracy in the rotation task. Additionally, we conducted a follow-up user study (N = 6) using swarm manipulation in two complex VR scenarios and obtained insights through semi-structured interviews, shedding light on optimized swarm control mechanisms and perceptual changes induced by this interaction paradigm. These results demonstrate the potential of the swarm manipulation technique to enhance the usability and user experience in VR compared to conventional manipulation techniques. In future studies, we aim to understand and improve swarm interaction via internal swarm particle cooperation.

Spherical Shell Bioprinting to Produce Uniform Spheroids with Controlled Sizes.

Conventional cell spheroid production methods are largely manual, leading to variations in size and shape that compromise consistency and reliability for use in cell-based therapeutic applications. To enhance spheroid production, a spherical shell bioprinting system was implemented, enabling the high-throughput generation of uniform cell spheroids with precisely controlled sizes. The system encapsulates cells within thin alginate hydrogel shells formed through bioprinting and ion crosslinking reactions. Alginate-calcium ion crosslinking created alginate shells that contained gelatin-based bioinks with embedded cells, facilitating spontaneous cell aggregation within the shells and eliminating the need for plastic wells. By adjusting cell concentrations in the alginate-gelatin bioink, we achieved precise control over spheroid size, maintaining a sphericity above 0.94 and size deviations within ±10 µm. This method has been successfully applied to various cell types including cancer cells, fibroblasts, chondrocytes, and epithelial cells, demonstrating its versatility. This scalable approach enhances the reliability of cell therapy and drug screening, offering a robust platform for future biomedical applications.

Towards Reliable ECG Analysis: Addressing Validation Gaps in the Electrocardiographic R-Peak Detection

Electrocardiographic (ECG) R-peak detection is essential for every sensor-based cardiovascular health monitoring system. To validate R-peak detectors, comparing the predicted results with reference annotations is crucial. This comparison is typically performed using tools provided by the waveform database (WFDB) or custom methods. However, many studies fail to provide detailed information on the validation process. The literature also highlights inconsistencies in reporting window size, a crucial parameter used to compare predictions with expert annotations to distinguish false peaks from the true R-peak. Additionally, there is also a need for uniformity in reporting the total number of beats for individual or collective records of the widely used MIT-BIH arrhythmia database. Thus, we aim to review validation methods of various R-peak detection methodologies before their implementation in real time. This review discusses the impact of non-beat annotations when using a custom validation method, allowable window tolerance, the effects of window size deviations, and implications of varying numbers of beats and skipping segments on ECG testing, providing a comprehensive guide for researchers. Addressing these validation gaps is critical as they can significantly affect validatory outcomes. Finally, the conclusion section proposes a structured concept as a future approach, a guide to integrate WFDB R-peak validation tools for testing any QRS annotated ECG database. Overall, this review underscores the importance of complete transparency in reporting testing procedures, which prevents misleading assessments of R-peak detection algorithms and enables fair methodological comparison.

Optical readout Micromegas for monitoring medical pencil scanning proton beams

Micro-pattern gaseous detectors (MPGDs), when integrated with optical imaging sensors, have been proven to effectively and accurately capture radiation beam information. To address the challenges of monitoring the dose and profile of medical pencil proton beams (MPPB), which have a high density of greater than 109 Hz/cm2, an optical readout micro-mesh gaseous structure (ORM) was proposed. A Micromegas prototype was manufactured with a glass substrate coated with transparent indium tin oxide as the detector anode. Its effective area is 8 cm × 8 cm. The ORM was firstly characterized with an Iron-55 X-ray source (55Fe) and a silver target X-ray tube individually, good energy resolution of 14.5% (FWHM), high gain greater than 104, and spatial resolution of 400 μm (10% MTF) were achieved. The prototype was then tested with the MPPB. The evaluation revealed linear dose responses exceeding 99% (R-squared value) for both single-point and nine-point beam spots at various beam energies and doses. The size and center position deviation of the nine-point spot measurement were within 0.35 mm and 1 mm, respectively, indicating the good potential of this method for MPPB spot quality assurance. Additionally, the ORM is expected to be expanded to monitor other types of high-flux beams, such as medical neutron and gamma beam inspections, by adding suitable conversion layers.

Shadow effect in dual‐source thermally evaporated perovskite patterns

AbstractPerovskite light‐emitting diodes (PeLEDs) have recently emerged as a potential next‐generation display technology due to their wide color gamut, high external quantum efficiency (EQE), and low fabrication cost. The thermal evaporation process with no solvent involvement and offers low substrate selectivity and high compatibility with production lines has attracted significant academic interest. However, in thermal evaporation processes, the shadow effect greatly affects the deposition size and positioning accuracy of the patterns, consequently impacting the effective device area and process repeatability of PeLEDs. In this study, we calculated the shadow distance during the dual‐source thermal evaporation and analyzed the issues of misalignment and size deviation caused by shadow effects. Based on the calculation of shadow distance, we increased the substrate height from 33 to 38 cm to enhance the deposition angle. This adjustment led to an improvement in the characteristic parameter W1/Wdot from 0.178 to 0.365 during perovskite deposition. As a result, we successfully obtained a high‐resolution perovskite array with uniform morphology and photofluorescence (PL) emission at 600 pixels per inch (ppi). This demonstrated the reliable calculation and analysis of shadow distance, which is effective for fine deposition of high‐resolution perovskite patterns and PeLEDs.

Enhancing melt foam stability, form-filling process, and pore structure evolution of shaped aluminum foam

This study explores the stability of Al–Si–Ca–Mg-Sc melt foams and investigates the melt foam filling process and the dynamic evolution of pore structures in the fabrication of foam aluminum profiles using the melt transfer foaming technique. The results show that Al–Si–Ca–Mg-Sc melt foam maintains high porosity and a stable pore structure even after 30 min of foaming, without any signs of boundary rupture or destabilization. This stability is attributed to the increased viscosity from finely dispersed second-phase particles, which hinder the growth, coalescence, and drainage of the melt foam. Regarding melt foam filling, enhanced filling capability is achieved by elevating the foaming temperature, extending the foaming time, and increasing the TiH2 addition. The melt foam exhibits a smooth flow from the lower part of the mold to the corners, completing the filling process with well-defined edges in the profile. During lateral movement for filling, a gradual increase in porosity, a decrease in pore number, and a slow enlargement of pore size and standard deviation along the lateral (x-axis) are observed. This is due to the slower liquid phase flow compared to the gas phase, resulting in bubble coalescence. After filling is complete, this phenomenon improves, contributing to a slow and stable evolution of the pore structure.Under optimized conditions of 1.4 wt% TiH2 addition at 600°Cfor 9 min of foaming with Al–Si–Ca–Mg-Sc alloy melting, we successfully fabricated foam aluminum profiles with complete filling, a porosity of 81.5%, an average pore size of 2–3 mm, and a uniform pore structure.

Determination of the particle size distribution of cube-shaped colloidal perovskite quantum dots from photoluminescence spectra: A combined theoretical-experimental approach.

A theoretical-experimental approach is proposed to convert the photoluminescence spectra of colloidal perovskite quantum dot ensembles into accurate estimates for their intrinsic particle size distribution functions. Two main problems were addressed and properly correlated: the size dependence of the first excitonic transition in a single cube-shaped quantum dot and the inhomogeneous broadening of the fluorescence line shape due to the size nonuniformity of the chemically prepared quantum dot suspension in addition to the single-dot homogeneous broadening. By applying the reported methodology to CsPbBr3 quantum dot samples belonging to the strong and intermediate confinement regimes, the calculated size distributions exhibited close agreement with those obtained from transmission electron microscopy, with precise estimates for the average particle size and standard deviation. Specifically for strongly confined ultrasmall CsPbBr3 quantum dots, the presented spectroscopic model for size distribution computation is based on a new analytical expression for the size-dependent bandgap, which was developed within the framework of the finite-depth square-well effective mass approximation accounting for band nonparabolicity effects. Such a quantum mechanical approach correctly predicts the expected transition to the intermediate confinement regime in sufficiently large quantum dots, which are traditionally described by the well-known bandgap equation in the infinite potential barrier limit with a spatially correlated electron-hole wavefunction and nonparabolic carrier effective masses. The proposed calculation scheme originates from general theoretical considerations so that it can be readily adapted to semiconductor quantum dots of many other systems, from all inorganic metal halides to hybrid perovskite materials, regardless of the adopted chemical synthesis route.

Highly sensitive multiplexed colorimetric lateral flow immunoassay by plasmon-controlled metal-silica isoform nanocomposites: PINs.

Lateral flow assay (LFA) systems use metal nanoparticles for rapid and convenient target detection and are extensively studied for the diagnostics of various diseases. Gold nanoparticles (AuNPs) are often used as probes in LFAs, displaying a single red color. However, there is a high demand for colorimetric LFAs to detect multiple biomarkers, requiring the use of multicolored NPs. Here, we present a highly sensitive multiplexed colorimetric lateral flow immunoassay by multicolored Plasmon-controlled metal-silica Isoform Nanocomposites (PINs). We utilized the localized surface plasmon resonance effect to create multi-colored PINs by precisely adjusting the distance between the NPs on the surface of PINs through the controlled addition of reduced gold and silver precursors. Through simulations, we also confirmed that the distance between nanoparticles on the surface of PINs significantly affects the color and colorimetric signal intensity of the PINs. We achieved multicolored PINs that exhibit stronger colorimetric signals, offering a new solution for LFA detection with high sensitivity and a 33 times reduced limit of detection (LOD) while maintaining consistent size deviations within 5%. We expect that our PINs-based colorimetric LFA will facilitate the sensitive and simultaneous detection of multiple biomarkers in point-of-care testing.

Changes and Influencing Factors of Corneal Endothelial Cells and Central Corneal Thickness after Pediatric Cataract Surgery

Introduction: This study aimed to examine the impact of cataract surgery on the corneal endothelium and central corneal thickness (CCT) in pediatric patients, and to identify the factors associated with corneal alterations. Methods: This retrospective study included consecutive children undergoing bilateral or unilateral cataract surgery and intraocular lens implantation at the Eye Hospital of Wenzhou Medical University, with or without posterior capsulorhexis and anterior vitrectomy, and an age-matched normal control group. This study aimed to assess whether changes in corneal parameters, including CCT, corneal endothelial cell density (CD), average cell area (AVE), standard deviation of size (SD), coefficient of variation (CV), percentage of hexagonal cells (6A) before and after surgery, and endothelial cell loss (ECL) differed among the bilateral cataract, unilateral cataract, and control groups. Furthermore, the potential effects of anterior vitrectomy, axial length, preoperative anterior chamber depth, surgical duration, horizontal corneal diameter, intraoperative pupil diameter (PD), and the number of corneal sutures on corneal endothelial parameters and CCT were investigated. Results: A total of 107 eyes from 107 children were included in the study. In the bilateral cataract group, CD significantly decreased, AVE and CCT significantly increased, and ECL was significantly higher than in the control group. The unilateral cataract group also exhibited a significant increase in CCT. Additionally, the number of corneal sutures was negatively correlated with CD, and PD was negatively correlated with CV in the unilateral cataract group. Conclusion: Cataract surgery in pediatric patients results in increased CCT, reduced CD, and morphological changes in corneal cells. A greater number of corneal sutures and a smaller PD increased the risk of CD reduction and elevated CV in the unilateral cataract group, underscoring the need for ophthalmologists to minimize corneal damage in these children.

Controlled Fabrication of Wafer-Scale, Flexible Ag-TiO2 Nanoparticle-Film Hybrid Surface-Enhanced Raman Scattering Substrates for Sub-Micrometer Plastics Detection.

As an important trace molecular detection technique, surface-enhanced Raman scattering (SERS) has been extensively investigated, while the realization of simple, low-cost, and controllable fabrication of wafer-scale, flexible SERS-active substrates remains challenging. Here, we report a facile, low-cost strategy for fabricating wafer-scale SERS substrates based on Ag-TiO2 nanoparticle-film hybrids by combining dip-coating and UV light array photo-deposition. The results show that a centimeter-scale Ag nanoparticle (AgNP) film (~20 cm × 20 cm) could be uniformly photo-deposited on both non-flexible and flexible TiO2 substrates, with a relative standard deviation in particle size of only 5.63%. The large-scale AgNP/TiO2 hybrids working as SERS substrates show high sensitivity and good uniformity at both the micron and wafer levels, as evidenced by scanning electron microscopy and Raman measurements. In situ bending and tensile experiments demonstrate that the as-prepared flexible AgNP/TiO2 SERS substrate is mechanically robust, exhibiting stable SERS activity even in a large bending state as well as after more than 200 tensile cycles. Moreover, the flexible AgNP/TiO2 SERS substrates show excellent performance in detecting sub-micrometer-sized plastics (≤1 μm) and low-concentration organic pollutants on complex surfaces. Overall, this study provides a simple path toward wafer-scale, flexible SERS substrate fabrication, which is a big step for practical applications of the SERS technique.

Eco‐friendly Green Synthesis of Silver Nanoparticles Using Daphne Mucronata Royle Seeds Extract and the Potential Antibacterial, Antifungal, and Scolicidal Activities

AbstractGreen synthesized silver nanoparticles (AgNPs) have received lots of attention due to being used as potential therapeutic agents. For the first time, this research investigated the biosynthesis of silver nanoparticles using the extract of Daphne mucronata seeds, which are rich in phenolic and polyphenolic substances and evaluated their antibacterial, antifungal, and scavenging activities. The process of nanoparticle (NPs) preparation was confirmed using UV–vis spectroscopy with an absorption peak at a wavelength of 440 nm. Dynamic light scattering (DLS) was used to determine the particles' distribution. Fourier‐transform infrared spectroscopy (FTIR) validated the functional groups contributing to the reduction of Ag+ to Ag. Moreover, X‐ray diffraction analysis (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) approved the crystalline nature and spherical shape of the particles with mean and standard deviation of particle size to be 60.25 and 24.88 nm, respectively. The antibacterial, antifungal, and scolicidal activities of AgNPs were studied using disc diffusion against four standard bacteria species and microdilution methods for four Candida strains. The greatest effect of AgNPs with the highest concentration (80 µg/mL) was observed on Staphylococcus aureus (22.26 mm) and the lowest on Pseudomonas aeruginosa (19.07 mm). In the case of Candida fungus, the highest effect of AgNPs was reported for Candida krusei (7.93 µg/mL) and the lowest for Candida albicans (63.49 µg/mL). Also, these nanoparticles were able to register 100% lethality on the Echinococcus granulosus parasite in 15 min at a concentration (80 µg/mL). Therefore, the production of AgNPs as a renewable and cheap material can be effective after performing all the necessary tests as antibacterial, antifungal and antiparasitic agents with the least side effects in biomedical and pharmaceutical sciences.

Thread plate posture analysis for screw rolling adjustment design

Abstract This research focuses on process design of the adjustment of movable thread plate and fixed thread plate in the screw rolling machine during production. By observing some key dimensions of the threaded screw, one can determine the movement amount and the rotation direction of the adjustment screw bars mechanism of the fixed thread plate that required for the specified size of this type of screw. One establishes a relationship from the adjustment of the screw bars mechanism to the fixed thread plate posture. It can be seen that the formed screw size deviations will lead the machine operator to adopt one of the proposed process to achieve the posture adjustment of the fixed thread plate. While the screw specification deviations do not conform to the standard ones, the operator just need to find out the error type of the formed screw and measures its specification to follow one of the proposed formulas, then the wrong thread plate posture can be modified to the correct posture under operator’s adjustment. The method addressed in this research can not only reduce the operational difficulty of screw thread rolling machine but also can reduce the trial-and-error processes in traditional operation methods.

Estimation of DNA content and genome size of some orchids using flow cytometry

Flow cytometry technique is used extensively in plant sciences to reveal the deviation of genomic size to better identify or resolve the closely related organisms or groups. In this study, extracted nuclei from the leaf tissue of ten Dendrobium species were analyzed for their DNA content. A flow cytometer was used to measure DNA content after extracting and specific staining of nuclei. Direct comparison was performed using chicken erythrocyte nuclei (1C DNA = 1.25 pg) as a standard. The calculated amount of DNA content showed the variation in the amount, ranging from 3.78 to 8.75pg, equivalent to a genomic size of 1852.20 to 4287.50 Mbp, respectively. There was no correlation between elevation and quantity of genome of studied Dendrobium species. It was observed that the quantity of a particular species DNA was inversely proportional to the size of their flowers and positively correlated with the plant height and leaf length. An ANOVA test among the four variables was performed and to identify the subsets that were distinct from one another, we performed Tukey’s HSD test. A pair-wise comparison was performed and among the six compressions, only the stem length significantly differed (mean = 97.873, p< 0.001) from other three variables.