Size Restrictions Research Articles

Hybrid ultrathin metasurface for broadband sound absorption

To this day, achieving broadband low-frequency sound absorption remains a challenge even with the possibilities promised by the advent of metamaterials and metasurfaces, especially when size and structural restrictions exist. Solving this engineering challenge relies on stringent impedance matching and coupling of the multiple independent local resonators in metasurface absorbers. In this Letter, we present an innovative design approach to broaden the sound absorption bandwidth at low-frequency regime. A hybrid metasurface design is proposed where four coupled planar coiled resonators are also coupled to a well-designed thin planar cavity. This hybrid metasurface creates a broad sound absorption band (130–200 Hz) that is twice as wide as that of the traditional single layer metasurface utilizing four coiled cavities at a deep subwavelength thickness (∼λ/51). This design strategy opens routes toward engineering a class of high-performance thin metasurfaces for ultra-broadband sound absorption, while keeping the planar size unchanged.

Ultrasmall Pd nanocrystals confined into Co-based metal organic framework-decorated MXene nanoarchitectures for efficient methanol electrooxidation

The natural scarcity and insufficient utilization of noble metal-based catalysts bring a heavy block in the way of the widespread applications of direct methanol fuel cells. Herein, we propose a feasible bottom-up approach to the construction of ultrasmall Pd nanocrystals confined into Co-based metal organic framework-decorated Ti3C2Tx MXene (Pd/MOF-MX) nanoarchitectures via a controllable solvothermal process. The ultrathin MXene nanolamellas and porous Co-based MOFs constitute an ideal hybrid carrier with high electron conductivity and large accessible surface areas, which not only facilitates the size restriction and uniform dispersion of Pd nanocrystals, but also ameliorates their intrinsic catalytic activity through the direct electronic interactions. By virtue of the pronounced synergistic coupling effects, the newly-developed Pd/MOF-MX nanoarchitectures exhibit markedly enhanced electrocatalytic properties towards the methanol oxidation reaction, including a large electrochemically active surface area of 116.7 m2 g−1, a high mass activity of 1700.4 mA mg−1 as well as a satisfactory long-term durability, which are superior to those of traditional Pd electrocatalysts anchored on carbon blacks, carbon nanotubes, graphene, and undecorated MXene matrixes.

Machine learning assisted Raman spectroscopy: A viable approach for the detection of microplastics

The accumulation of microplastics (MPs) resulting from disposal of plastic waste into water sources, poses a significant threat to aquatic organisms. These are readily ingested by organisms, leading to the accumulation of harmful substances, disrupting their biological processes. Current methods for identifying microplastics have notable drawbacks, including low resolution, extended imaging time, and restricted particle size analysis. Integrating Raman spectroscopy with machine learning (ML) proves to be an effective approach for identifying and classifying MPs, especially in scenarios where they are found in environmental media or mixed with various types. Machine learning (ML) can be vital tool in assisting Raman analysis, owing to its robust feature extraction capabilities. This comprehensive review outlined the utilization of various machine learning techniques in conjunction with Raman spectral features for diverse investigations related to microplastics. The methodologies discussed encompass Principal Component Analysis, K-Nearest Neighbour, Random Forest, Support Vector Machine, and various deep learning algorithms.

Genetic insights into across pancreatitis types: the causal influence of immunoglobulin G N-glycosylation variants on disease risk.

While a few case-control studies indicated a possible correlation of IgG N-glycosylation patterns with pancreatitis, their restricted sample sizes and methodologies prevented conclusive insights into causality or distinguishing traits across pancreatitis types. We conducted a two-sample Mendelian Randomization (MR) analysis to investigate the causal relationship between 77 IgG N-glycosylation traits and various types of pancreatitis, including acute pancreatitis (AP), chronic pancreatitis (CP), alcohol acute pancreatitis (AAP), and alcohol chronic pancreatitis (ACP). This analysis utilized summary-level data from genome-wide association studies (GWAS), employing methods such as IVW, MR-Egger, and weighted median. To ensure the robustness of our findings, several sensitivity analyses, including Cochran's Q statistic, leave-one-out, MR-Egger intercept, and MR-PRESSO global test were conducted. Our study uncovered the causal relationship between specific IgG N-glycosylation traits and various types of pancreatitis. Notably, an increase in genetically predicted IGP7 levels was associated with a decreased risk of developing AP. For CP, our data suggested a protective effect associated with higher levels of both IGP7 and IGP31, contrasting with increased levels of IGP27 and IGP65, which were linked to a heightened risk. Moreover, in the case of AAP, elevated IGP31 levels were causatively associated with a lower incidence, while higher IGP26 levels correlated with an increased risk for ACP. This study establishes causal relationship between specific IgG N-glycosylation patterns and varying risks of different pancreatitis forms, underscoring their potential as predictive biomarkers. These findings necessitate further exploration into the underlying mechanisms, promising to inform more personalized diagnostic and therapeutic strategies in pancreatitis management.

Shape transformation on curved surfaces using a phase-field model

Shape transformation on evolving curved surfaces is essential for its diverse applications across various scientific disciplines and facilitates the deeper understanding of natural phenomena, the development of new materials, and engineering design optimization. In this study, we develop a phase-field model and its numerical methods for shape transformation on curved surfaces. A modified surface Allen–Cahn (AC) equation with a fidelity term is proposed to simulate shape transformation on curved surfaces. To numerically solve the modified surface AC equation on curved surfaces, we propose a fully explicit scheme and an unconditionally stable method. The proposed stable approach is not only simple and efficient to implement numerically but is also unconditionally stable and eliminates the restrictive temporal time step size constraints. Through numerical experiments using the proposed approach, we demonstrate that shape transformation on evolving curved surfaces can be implemented on both simple and complex curved surfaces.

Optical system for extremely large spectroscopic survey telescope

This article presents research work on a spectroscopic survey telescope. Our idea is as follows: for such a telescope, a pure reflecting optical system is designed, which should have an aperture and a field of view (FOV) both as large as possible and excellent image quality, and then a strip lensm (lens-prism) atmospheric dispersion corrector (S-ADC) is added, only for correcting the atmospheric dispersion. Given the fund limitation and the simplicity of scaling up, some 12-m telescopes are designed as examples. Su, Korsch, and Meinel put forward the four-mirror Nasmyth systems I and II, which are used in this paper. FOVs of 1.5°, 2°, and 2.5° are selected. For all systems, the image qualities are excellent. Because the S-ADC relaxes the optical glass size restriction, this 12-m telescope with a FOV of 2.5° can be magnified in proportion to a 16-m telescope. Its etendue (from French étendue) and focal surface will now be the largest in the world. In such a telescope, a pure reflecting optical system can also be obtained. A subsequent coudé system is designed with excellent image quality.

Finite speed axially symmetric Navier-Stokes flows passing a cone

Let D be the exterior of a cone inside a ball, with its altitude angle at most π/6 in R3, which touches the x3 axis at the origin. For any initial value v0=v0,rer+v0,θeθ+v0,3e3 in a C2(D‾) class, which has the usual even-odd-odd symmetry in the x3 variable and has the partial smallness only in the swirl direction: |rv0,θ|≤1100, the axially symmetric Navier-Stokes equations (ASNS) with Navier-Hodge-Lions slip boundary condition have a finite-energy solution that stays bounded for all time. In particular, no finite-time blowup of the fluid velocity occurs. Compared with standard smallness assumptions on the initial velocity, no size restriction is made on the components v0,r and v0,3. In a broad sense, this result appears to solve 2/3 of the regularity problem of ASNS in such domains in the class of solutions with the above symmetry. Equivalently, this result is connected to the general open question which asks that if an absolute smallness of one component of the initial velocity implies the global smoothness, see e.g. page 873 in Chemin et al. (2017) [6]. Our result seems to give a positive answer in a special setting.As a byproduct, we also construct an unbounded solution of the forced Navier Stokes equation in a special cusp domain that has finite energy. The forcing term, with the scaling factor of −1, is in the standard regularity class, and it can be generated by an electric current in a long and straight wire (i.e. Ampère force). This result confirms the intuition that if the channel of a fluid is very thin, arbitrarily high speed in the classical sense can be attained under a mildly singular, physically reasonable force.

Abstract A063: What can we learn from a retrospective evaluation of HER2, P53 and P16INK4A protein expression in rare ovarian tumors?

Abstract A063: What can we learn from a retrospective evaluation of HER2, P53 and P16INK4A protein expression in rare ovarian tumors?

Flight dynamics of aircraft incorporating the semi-aeroelastic hinge

Aircraft like the Boeing 777-X use on-ground folding wingtips to meet the airport gate size restriction while increasing the aspect ratio during flight to reduce induced drag. A recent concept of aircraft design is to utilise in-flight floating wingtips as a means of load alleviation, which is known as semi-aeroelastic hinge (SAH). This device allows wingtips to be released during manoeuvre and severe gusts to alleviate wing loads, while locking the wingtips during cruise to maintain an optimum aerodynamic shape. This paper develops a flight mechanics model incorporating flexible wings to study the influence of the SAH device on multiple aspects of aircraft flight dynamics. The dynamic responses of the aircraft to gusts and control surface inputs are computed and compared for various hinge and wingtip configurations and release times. It was found that the gust load measured from the wing with free hinge configuration was approximately 40% lower compared to that of the fixed hinge case. It is also shown that when the SAH is released, it can significantly reduce an aircraft's roll damping and the frequency of the short-period mode, leading to higher roll and pitch rates. Furthermore, it shows that the transient responses following the wingtip release will exacerbate the responses induced by gusts, and greater load alleviation can be achieved by manipulating the hinge release time for each gust length. Finally, a step input of the elevator during the hinge release was found to be beneficial for enhancing the gust load alleviation.

Bone formation in large/moderate gap after immediate implantation in response to different treatments: a pre-clinical study in the canine posterior mandible.

This study aims to investigate different treatments on new bone formation around immediate implants in the canine posterior mandible with varying sized mesial-distal gap. The 4th premolar and the 1st molar of six Labrador dogs were extracted from the mandible, and 4 dental implants were placed 1mm below the level of the buccal bone crest. Moderate/large mesial-distal gaps between the implants and the sockets were treated with one of four methods and divided into the following groups: (1) the blank group, (2) the collagen membrane (CM) group, (3) the deproteinized bovine bone mineral (DBBM) group, and (4) the DBBM + CM group. Sequential fluorescent labeling was performed at 4, 8, and 10 weeks after the operation. After 12 weeks, the dogs were euthanized, and specimens were collected for micro-CT scanning and histological analysis. The survival rate of immediate implant was 100%. Micro-CT showed significant differences in bone mineral density (BMD) and bone volume fraction (BVF) among groups (P = 0.040, P = 0.009); other indicators were not significantly different among groups. Histological analysis showed the proportion of new bone formation and bone-to-implant contact were not significantly different among groups. No significant difference in bone reduction height around dental implant among four groups and varied mesial-distal gap size. Owing to the restricted sample size, this pilot study lacks conclusive findings. Within the limitation, this study demonstrated that although DBBM significantly increase BMD and BVF, the use of DBBM/CM didn't significantly improve bone formation and healing in extraction sockets around the implants in both moderate and large mesial-distal gap. The use of deproteinized bovine bone in conjunction with collagen is a common practice in immediate implantation procedures in the posterior mandible. However, there is a lack of conclusive evidence regarding the timing and circumstances under which they should be employed.

Harnessing the advances of MEDA to optimize multi-PUF for enhancing IP security of biochips

Digital microfluidic biochips (DMFBs) have a significant stride in the applications of medicine and the biochemistry in recent years. DMFBs based on micro-electrode-dot-array (MEDA) architecture, as the next-generation DMFBs, aim to overcome drawbacks of conventional DMFBs, such as droplet size restriction, low accuracy, and poor sensing ability. Since the potential market value of MEDA biochips is vast, it is of paramount importance to explore approaches to protect the intellectual property (IP) of MEDA biochips during the development process. In this paper, an IP authentication strategy based on the multi-PUF applied to MEDA biochips is presented, called bioMPUF, consisting of Delay PUF, Split PUF and Countermeasure. The bioMPUF strategy is designed to enhance the non-linearity between challenges and responses of PUFs, making the challenge–response pairs (CRPs) on the MEDA biochips are difficult to be anticipated, thus thwarting IP piracy attacks. Moreover, based on the easy degradation of MEDA biochip electrodes, a countermeasure is proposed to destroy the availability of piracy chips. Experimental results demonstrate the feasibility of the proposed bioMPUF strategy against the brute force attack and modeling attack.

A comprehensive systematic review and meta-analysis of Listeria monocytogenes prevalence in food products in South Korea

Listeria monocytogenes is a foodborne pathogen that can cause deadly severe listeriosis. While systematic review and meta-analysis are powerful tools for comprehensive analysis by pooling every related study, these approaches to L.monocytogenes contamination food have yet to be studied in South Korea. We aimed to identify high-risk L.monocytogenes foods in South Korea through a prevalence survey of retail food products for the first time. A total of 13,684 samples of 59 articles were used for meta-analysis through the systematic review, and the results were synthesized using a random-effects model considering the heterogeneity. The overall pooled prevalence was 2.26 % (95 % CI: 1.44–3.52 %). Among nine food categories, meat exhibited the highest prevalence at 8.32 % (95 % CI: 4.42–12.14 %) after sample size restriction. Specifically, a post-hoc sensitivity analysis was conducted to identify the prevalence difference among subgroups and the source of heterogeneity. Intriguingly, the analysis revealed chicken as the primary contributor to the elevated prevalence of L.monocytogenes, a key factor deriving the observed heterogeneity. This study carries significant implications for public health and food safety in Korea. Furthermore, knowledge of differences in prevalence levels in various foods will be able to be used as a predictive guideline for foodborne outbreaks.

Integration of One-Dimensional (1D) Lead-Free Perovskite Microbelts onto Silicon for Ultraviolet-Visible-Near-Infrared (UV-vis-NIR) Heterojunction Photodetectors.

Lead-free perovskites are considered to be candidates for next-generation photodetectors, because of their excellent charge carrier transport properties and low toxicity. However, their application in integrated circuits is hindered by their inadequate performance and size restrictions. To aim at the development of lead-free perovskite-integrated optoelectronic devices, a CsAg2I3/silicon (CAI/Si) heterojunction is presented in this work by using a spatial confinement growth method, where the in-plane growth of CAI microbelts with high-quality single-crystal characteristics is primarily dependent on the concentration of surrounding precursor solution. The fabricated photodetectors based on the CAI/Si heterojunctions exhibit a broad-spectrum detection capability in the ultraviolet-visible-near-infrared (UV-vis-NIR) range. In addition, the photodetectors show good photoelectric detection performance, including a maximum responsivity of 48.5 mA/W and detectivity of 1.13 × 1011 Jones, respectively. Besides, the photodetectors have a rapid response of 6.5/224 μs and good air stability for over 2 months. This work contributes a new idea to design next-generation optoelectronic devices with high integration density.

Patterns of Wolf Dispersal Respond to Harvest Density across an Island Complex.

Wolves are highly mobile predators and can disperse across a variety of habitats and over long distances. However, less is known about dispersal capabilities across water and among islands. The biogeography of island systems fosters spatially structured local populations, and their degree of connectivity may influence the dynamics and long-term viability of the regional population. We sought to quantify wolf dispersal rate, distance, and dispersal sex bias throughout Prince of Wales Island, a 6670 km2 island in southeast Alaska, and the surrounding islands that constitute the wildlife management unit (9025 km2). We also investigated patterns of dispersal in relation to hunting and trapping intensity and wolf population density. We used DNA data collected during 2012-2021 long-term monitoring efforts and genotyped 811 wolves, 144 of which (18%) were dispersers. Annual dispersal rates were 9-23% and had a weakly positive relationship with wolf density. Wolves dispersed 41.9 km on average (SD = 23.7 km), and males and females did not disperse at different rates. Of the dispersing wolves, 107 died, and the majority (n = 81) died before they were able to settle. The leading manner of death was trapping (97% of mortalities), and wolves tended to disperse from areas with low harvest density to areas where harvest density was relatively higher. Dispersal occurred both to and from small islands and the larger Prince of Wales Island, indicating bidirectional as opposed to asymmetrical movement, and the genetic overlap of wolf groups demonstrates connectivity throughout this naturally patchy system. Island ecosystems have different predator-prey dynamics and recolonization processes than large, intact systems due to their isolation and restricted sizes; thus, a better understanding of the degree of population connectivity including dispersal patterns among islands in the Prince of Wales archipelago could help inform the management and research strategies of these wolves.

Bulbophyllum gopalianum (Orchidaceae), a new species from Mizoram (India), the westernmost region of the Indo‐Myanmar biodiversity hotspot

A new species, Bulbophyllum gopalianum, is described from the montane sub‐tropical forest of Mizoram (India) in the westernmost area of the Indo‐Myanmar biodiversity hotspot. The new species belongs to the section Lemniscata and shows close morphological affinity to B. suavissimum and B. shanicum. A detailed description, diagnosis, phenology, taxonomic notes and conservation assessment are presented. The new species is assessed as critically endangered (CR) based on its very small and restricted population size.

Konservasi sebagai landasan perencanaan lansekap berbasis tempat pada masyarakat Baduy Dalam di Kabupaten Lebak Provinsi Banten

The Baduy clan is one of the native Sundanese clans that actually sticks to its traditions precursors, their lives are committed to satisfying the order of their predecessors in securing equilibrium and congruity of the universe. Advancement exercises, neighborhood environmental change andGlobalization represents a danger to conventional clans, like the Baduy clan too. The consequences of the grouping and bioregional examination of the Baduy Dalam scene can be arranged into 103 place unit. Assessment is done at every area unit in light of dangers and issues every unit. The principal issue found in the Inward Baduy scene is its restricted size accessibility of agrarian land assets which can be utilized in turn so that has suggestions for diminishing area richness. Then again, the populace development rate is very high requests an expansion in the requirement for farming creation land. The answer for this issue was understood as a scene plan created in light of the idea of partitioning space with adjusting land use for useful purposes to have the option to earn barely enough to get by. inhabitants for rural creation land. Scene plan executed in spatial plans (drafting), dissemination plans, and vegetation plans.

Power supply thermal analysis

The article provides an analysis of heat removal from power elements in a low-power power source. The efficiency of cooling fuel elements using the free convection method without additional inclusion of active cooling is considered due to design limitations of the overall dimensions of the source. Calculation estimates were made using numerical modeling of the temperature regime of the source. The object of the study is an intrinsically safe power supply with size restrictions of 200×160×65 mm with an aluminum housing. The main heat-generating elements are power transistors with a power of 1 to 6 W, mounted on the heat-dissipating parts of the housing through an insulating gasket. For stable operation of semiconductors, a temperature regime is required without exceeding the transistor temperature of 85 ° C under standard environmental conditions at an air temperature of 20 ° C and a relative humidity of 20%. The authors analyzed the heat exchange between the model of the designed power supply housing and the air environment according to the parameter of the limiting temperature of heat-generating semiconductors in a steady state. Conclusions about whether the thermal operating conditions are adequately ensured for this case are made.

Biogenic synthesis of silver nanoparticles from the leaf extract of Enicostema axillare (Poir. ex Lam.) A. Raynal and its alpha amylase inhibition activity

Due to its numerous applications, commercial demand for silver nanoparticles produced by biological means is rising. This procedure has no adverse effects, is inexpensive, takes little time, and is non-toxic. The current work uses leaf extracts from Enicostema axillare (Mamajavo) to synthesise silver nanoparticles. The nanoparticles may be characterised by UV–VIS, FT-IR, SEM, TEM, and EDAX. The effectiveness of the screening inhibition assay and alpha-amaylase inhibitory activities is assessed using methanolic leaf extracts and silver nanoparticles. The outcome shows that AgNps exhibit aggregates of grains with a restricted size distribution range between 60 and 80 nm. In comparison to leaf extract, silver nanoparticles made from methanolic leaf extracts have high alpha-amaylase inhibitory action. This study showed that Enicostema axillare's AgNps decrease in the presence of alpha-amylase inhibitors.

The Economic and Geopolitical Implications of China's Belt and Road Initiative in Eastern Europe: A Case Study on Serbia

This paper critically analyses the economic and geopolitical consequences of China's Belt and Road Initiative (BRI) on Serbia. The primary focus is on the initiative's effects on the country's infrastructure development, employment, and trade sectors. The study adopts a positivist research ethic and employs a deductive technique. It utilizes quantitative methodologies by administering an online survey to 350 practitioners actively engaged in BRI projects in Serbia. The data analysis was conducted using the SPSS program. The research findings demonstrate that the infrastructure investment and employment generation associated with the BRI have had notable positive impacts on Serbia's economic and geopolitical development. Moreover, it has been discovered that trade dynamics with China have the potential to bolster economic growth and foster positive geopolitical relations. Nevertheless, the study admits many limitations, including a restricted sample size and the lack of qualitative data. Future study recommendations encompass the need for enhanced stakeholder engagement on a wider scale and the implementation of longitudinal studies to effectively capture the dynamic and evolving impacts over time.

HIV-1 capsids enter the FG phase of nuclear pores like a transport receptor

HIV-1 infection requires nuclear entry of the viral genome. Previous evidence suggests that this entry proceeds through nuclear pore complexes (NPCs), with the 120 × 60 nm capsid squeezing through an approximately 60-nm-wide central channel1 and crossing the permeability barrier of the NPC. This barrier can be described as an FG phase2 that is assembled from cohesively interacting phenylalanine–glycine (FG) repeats3 and is selectively permeable to cargo captured by nuclear transport receptors (NTRs). Here we show that HIV-1 capsid assemblies can target NPCs efficiently in an NTR-independent manner and bind directly to several types of FG repeats, including barrier-forming cohesive repeats. Like NTRs, the capsid readily partitions into an in vitro assembled cohesive FG phase that can serve as an NPC mimic and excludes much smaller inert probes such as mCherry. Indeed, entry of the capsid protein into such an FG phase is greatly enhanced by capsid assembly, which also allows the encapsulated clients to enter. Thus, our data indicate that the HIV-1 capsid behaves like an NTR, with its interior serving as a cargo container. Because capsid-coating with trans-acting NTRs would increase the diameter by 10 nm or more, we suggest that such a ‘self-translocating’ capsid undermines the size restrictions imposed by the NPC scaffold, thereby bypassing an otherwise effective barrier to viral infection.