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1.
J Periodontol ; 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38563593

RESUMO

BACKGROUND: To compare acceptance and preference of topical lidocaine gel anesthesia with articaine injection anesthesia in patients with moderate periodontitis undergoing scaling and root debridement. METHODS: Ninety-one patients completed this randomized multicenter split-mouth controlled study and underwent two separate periodontal treatment sessions on different days, one with a topical intrapocket lidocaine gel application and the other with an articaine injection anesthesia in a different order depending on randomization. Parameters measured were the patients' preference for topical lidocaine gel anesthesia or injection anesthesia with articaine (primary efficacy criterion), their maximum and average pain, and their intensity of numbness as well as experience of side effects; the probing depth; and the dentists' preference and their evaluations of handling/application, onset and duration of anesthetic effect, and patient compliance. RESULTS: After having experienced both alternatives, 58.3% of the patients preferred the topical lidocaine gel instillation into the periodontal pockets. The safety profile of the lidocaine gel differed positively from the safety profile of articaine injection in type and frequency of adverse drug reactions. The dentists' acceptance and preference regarding either anesthetic method studied were balanced. CONCLUSIONS: Instillation of lidocaine gel into the periodontal pocket is a preferred alternative to injection anesthesia for most of the patients and an equivalent alternative for dentists in nonsurgical periodontal therapy.

2.
Am J Bot ; : e16312, 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38576091

RESUMO

Forests are facing unprecedented levels of stress from pest and disease outbreaks, disturbance, fragmentation, development, and a changing climate. These selective agents act to alter forest composition from regional to cellular levels. Thus, a central challenge for understanding how forests will be impacted by future change is how to integrate across scales of biology. Phenotype, or an observable trait, is the product of an individual's genes (G) and the environment in which an organism lives (E). To date, researchers have detailed how environment drives variation in tree phenotypes over long time periods (e.g., long-term ecological research sites [LTERs]) and across large spatial scales (e.g., flux network). In parallel, researchers have discovered the genes and pathways that govern phenotypes, finding high degrees of genetic control and signatures of local adaptation in many plant traits. However, the research in these two areas remain largely independent of each other, hindering our ability to generate accurate predictions of plant response to environment, an increasingly urgent need given threats to forest systems. I present the importance of both genes and environment in determining tree responses to climate stress. I highlight why the difference between G versus E in driving variation is critical for our understanding of climate responses, then propose means of accelerating research that examines G and E simultaneously by leveraging existing long-term, large-scale phenotypic data sets from ecological networks and adding newly affordable sequence (-omics) data to both drill down to find the genes and alleles influencing phenotypes and scale up to find how patterns of demography and local adaptation may influence future response to change.

3.
J Pharm Bioallied Sci ; 16(Suppl 1): S492-S494, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38595340

RESUMO

Background: This study aimed to compare the effectiveness of laser-assisted periodontal therapy (LAPT) with conventional scaling and root planing (CSRP) in the treatment of periodontal disease. The objective was to assess the outcomes of these two treatments on a sample of 30 patients in each group. Materials and Methods: In this study, a total of 60 patients diagnosed with periodontal disease were divided into two groups: the LAPT group and the CSRP group, with 30 patients in each group. The LAPT group received periodontal treatment using laser therapy, while the SRP group underwent traditional SRP. The patients were evaluated for periodontal parameters, including probing depth and clinical attachment level before and after the treatments. Results: After the treatment interventions, both the LAPT group and the CSRP group showed significant improvements in periodontal health. The mean reduction in probing depth was 2.5 mm in the LAPT group and 2.2 mm in the SRP group. In addition, the clinical attachment level increased by 2.8 mm in the LAPT group and 2.5 mm in the SRP group. Statistical analysis using the paired t-test demonstrated a P-value of less than 0.05, indicating the significance of these improvements in both groups. Conclusion: This study suggests that both LAP and CSRP are effective in improving periodontal health in patients with periodontal disease.

4.
J Pharm Bioallied Sci ; 16(Suppl 1): S880-S882, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38595618

RESUMO

Background: This study compares the effectiveness of laser-assisted periodontal therapy (LAPT) to conventional scaling and root planing (SRP) in the treatment of periodontal disease. Materials and Methods: Patients with periodontal disease were divided into two groups. One group received LAPT, while the other group underwent conventional SRP. The periodontal parameters, including pocket depth (PD) and clinical attachment level (CAL), were measured before and after the treatments. The data were statistically analyzed using appropriate methods. Results: After the treatments, the LAPT group showed a mean reduction in PD of 2.5 mm, while the conventional SRP group had a mean reduction of 2.0 mm. Additionally, the laser group demonstrated a mean improvement in CAL of 1.8 mm, whereas the conventional group showed an improvement of 1.3 mm. These differences were statistically significant (P < 0.05). Conclusion: The findings of this study suggest that LAPT may be more effective in reducing PD and improving CAL compared with conventional SRP in the treatment of periodontal disease.

5.
Small ; : e2303243, 2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38600877

RESUMO

Supercapacitive swing adsorption (SSA) modules with bipolar stacks having 2, 4, 8, and 12 electrode pairs made from BPL 4 × 6 activated carbon are constructed and tested for carbon dioxide capture applications. Tests are performed with simulated flue gas (15%CO2 /85%N2) at 2, 4, 8, and 12 V, respectively. Reversible adsorption with sorption capacities (≈58 mmol kg-1) and adsorption rates (≈38 µmol kg-1 s-1) are measured for all stacks. The productivity scales with the number of cells in the module, and increases from 70 to 390 mmol h-1 m-2. The energy efficiency and energy consumption improve with increasing number of bipolar electrodes from 67% to 84%, and 142 to 60 kJ mol-1, respectively. Overall, the results show that SSA modules with bipolar electrodes can be scaled without reducing the adsorptive performance, and with improvement of energetic performance.

6.
Data Brief ; 54: 110347, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38586140

RESUMO

The data of physicochemical control for the cooling water supply system of the Rivne Nuclear Power Plant (Ukraine), where water samples were monitored three times a day during 2022-2023. The pH, temperature, total dissolved salts, total hardness and total alkalinity were measured using standard methods. The differences in ϕ and ψ, Langelier saturation index (LSI) and Ryznar stability index (RSI), which characterise scaling and corrosive potential, were calculated The calculated values are ϕ - ψ: 0.29 (± 0.62), LSI: 1.51 (± 0.39), and RSI 5.74 (± 0.69). According to the scaling and corrosive classification, the water is characterised as susceptible to scale formation. Moreover, to the Pearson correlation coefficient (ρ), there is a very strong relationship ρ = -0.9635 between LSI and RSI, a weak relationship ρ = -0.2370 between ϕ - ψ and RSI, and ρ = -0.2997 between ϕ - ψ and LSI.

7.
J Am Heart Assoc ; 13(8): e034029, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38567667

RESUMO

BACKGROUND: Normalization of echocardiographic chamber measurements for body surface area may result in misclassification of individuals with obesity or sarcopenia. Normalization for alternative measures of body size may be preferable, but there remains a dearth of information on their normative values and association with cardiovascular function metrics. METHODS AND RESULTS: A total of 3032 individuals underwent comprehensive 2-dimensional echocardiography at Exam 6 in MESA (Multi-Ethnic Study of Atherosclerosis). In the subgroup of 608 individuals free of cardiopulmonary disease (69.5±7.0 years, 46% male, 48% White, 17% Chinese, 15% Black, 21% Hispanic), normative values were derived for left and right cardiac chamber measurements across a variety of ratiometric (body surface area, body mass index, height) and allometric (height1.6, height2.7) scaling parameters. Normative upper and lower reference values were provided for each scaling parameter stratified across age groups, sex, and race or ethnicity. Among scaling parameters, body surface area and height were associated with the least variability across race and ethnicity categories and height2.7 was associated with the least variability across sex categories. CONCLUSIONS: In this diverse cohort of community-dwelling older adults, we provide normative values for common echocardiographic parameters across a variety of indexation methods.


Assuntos
Aterosclerose , Ventrículos do Coração , Humanos , Masculino , Idoso , Feminino , Valores de Referência , Ecocardiografia/métodos , Etnicidade , Aterosclerose/diagnóstico por imagem
8.
Molecules ; 29(7)2024 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-38611822

RESUMO

A model potential previously developed for the ammonia molecule is treated in a single-center partial-wave approximation in analogy with a self-consistent field method developed by Moccia. The latter was used in a number of collision studies. The model potential is used to calculate DC Stark resonance parameters, i.e., resonance positions and shifts using the exterior complex scaling method for the radial coordinate. Three molecular valence orbitals are investigated for fields along the three Cartesian coordinates, i.e., along the molecular axis and in two perpendicular directions. The work extends previous work on the planar-geometry water molecule for which non-monotonic shifts were observed. We find such non-monotonic shifts for fields along the molecular axis. For perpendicular fields, we report the splitting of the 1e orbitals into a fast- and a slow-ionizing orbital.

9.
Hum Genomics ; 18(1): 38, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38627868

RESUMO

BACKGROUND: Congenital ichthyosis (CI) is a collective group of rare hereditary skin disorders. Patients present with epidermal scaling, fissuring, chronic inflammation, and increased susceptibility to infections. Recently, there is increased interest in the skin microbiome; therefore, we hypothesized that CI patients likely exhibit an abnormal profile of epidermal microbes because of their various underlying skin barrier defects. Among recruited individuals of Southeast Asian ethnicity, we performed skin meta-genomics (i.e., whole-exome sequencing to capture the entire multi-kingdom profile, including fungi, protists, archaea, bacteria, and viruses), comparing 36 CI patients (representing seven subtypes) with that of 15 CI age-and gender-matched controls who had no family history of CI. RESULTS: This case-control study revealed 20 novel and 31 recurrent pathogenic variants. Microbiome meta-analysis showed distinct microbial populations, decreases in commensal microbiota, and higher colonization by pathogenic species associated with CI; these were correlated with increased production of inflammatory cytokines and Th17- and JAK/STAT-signaling pathways in peripheral blood mononuclear cells. In the wounds of CI patients, we identified specific changes in microbiota and alterations in inflammatory pathways, which are likely responsible for impaired wound healing. CONCLUSIONS: Together, this research enhances our understanding of the microbiological, immunological, and molecular properties of CI and should provide critical information for improving therapeutic management of CI patients.


Assuntos
Ictiose , Microbiota , Humanos , Estudos de Casos e Controles , Leucócitos Mononucleares , População do Sudeste Asiático , Inflamação/genética , Microbiota/genética , Ictiose/genética
10.
Proc Natl Acad Sci U S A ; 121(17): e2314103121, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38640345

RESUMO

The central aim of quantum networks is to facilitate user connectivity via quantum channels, but there is an open need for benchmarking metrics to compare diverse quantum networks. Here, we propose a general framework for quantifying the performance of a quantum network by estimating the value created by connecting users through quantum channels. In this framework, we define the quantum network utility metric [Formula: see text] to capture the social and economic value of quantum networks. The proposed framework accommodates a variety of applications from secure communications to distributed sensing. As a case study, we investigate the example of distributed quantum computing in detail. We determine the scaling laws of quantum network utility, which suggest that distributed edge quantum computing has more potential for success than its classical equivalent. We believe the proposed utility-based framework will serve as a foundation for guiding and assessing the development of quantum network technologies and designs.

11.
Toxicology ; : 153806, 2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38642821

RESUMO

This study aimed to investigate sex, age, and species differences of perfluorooctanoic acid (PFOA) using physiologically-based pharmacokinetic (PBPK) models in rats and humans. PBPK models were generally developed as either flow- or permeability-limited models. The flow-limited model is cost-effective and allows for human PK prediction through simple allometric scaling, while the permeability-limited model can incorporate detailed information on the disposition process through in vitro-in vivo extrapolation (IVIVE). PFOA was administered via oral or intravenous administration with 5mg/kg in male and female rats of different ages and the data was used to develop the PBPK models. Our results showed that both models successfully captured sex differences in rats, while only the flow-limited model with male rats and the permeability-limited model with both male and female rats provided comparable predictions in the human clinical study. More than the flow-limited model, the permeability-limited model effectively explained sex differences in rats and species differences through IVIVE. Additionally, the ontogeny-based mechanistic description of PFOA disposition enabled the interpretation of age- and sex-dependent pharmacokinetics. Although the flow-limited PBPK model lacked mechanistic interpretability compared to the permeability-limited model, it demonstrated reliable human prediction through simple allometric scaling. In conclusion, the permeability PBPK model could interpret age, sex, and species differences and it could improve the accuracy of human prediction.

12.
Water Res ; 256: 121594, 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38615603

RESUMO

Membrane distillation (MD) has emerged as a promising technology for desalination and concentration of hypersaline brine. However, the efficient preparation of a structurally stable and salinity-resistant membrane remains a significant challenge. In this study, an amphiphobic polytetrafluoroethylene nanofibrous membrane (PTFE NFM) with exceptional resistance to scaling has been developed, using an energy-efficient method. This innovative approach avoids the high-temperature sintering treatment, only involving electrospinning with PTFE/PVA emulsion and subsequent low-temperature crosslinking and fluorination. The impact of the PVA and PTFE contents, as well as the crosslinking and subsequent fluorination on the morphology and MD performance of the NFM, were systematically investigated. The optimized PTFE NFM displayed robust amphiphobicity, boasting a water contact angle of 155.2º and an oil contact angle of 132.7º. Moreover, the PTFE NFM exhibited stable steam flux of 52.1 L·m-2·h-1 and 26.7 L·m-2·h-1 when fed with 3.5 wt % and 25.0 wt % NaCl solutions, respectively, and an excellent salt rejection performance (99.99 %, ΔT = 60 °C) in a continuous operation for 24 h, showing exceptional anti-scaling performance. It also exhibited stable anti-wetting and anti-fouling properties against surfactants (sodium dodecyl sulfate) and hydrophobic contaminants (diesel oil). These results underscore the significant potential of the PTFE nanofibrous membrane for practical applications in desalination, especially in hypersaline or polluted aqueous environments.

13.
Cureus ; 16(3): e56509, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38646204

RESUMO

AIM: To assess and contrast the effectiveness of systemic doxycycline and diode laser as supplements to scaling and root planing (SRP) in terms of clinical and microbiological parameters. MATERIALS AND METHODS: A total of 33 patients diagnosed with periodontitis stages II and III were included and randomized into group A (SRP + diode laser), group B (SRP + doxycycline), and group C (SRP alone). Selected sites were assessed for clinical and microbial parameters-plaque index (PI), gingival index (GI), pocket probing depth (PPD), relative attachment level (RAL), and colony-forming units (CFUs). Every clinical parameter was noted at baseline and after three months. The arithmetic mean, followed by the standard deviation, was calculated for the required assessment intervals. Analysis of variance (ANOVA) was used to compare all parameters between groups, and if the results of the ANOVA test were significant, post hoc analysis was performed. For intragroup comparison, student t-tests were performed. RESULTS: The clinical parameters significantly improved within three months for all groups. In terms of relative attachment level, a statistically significant difference (P < 0.001) was obtained at the three-month interval compared to the baseline value, with the most statistically significant difference seen in group A (3.36±0.50 to 0.64±0.50), followed by group B (3.18±0.40 to 2.18±0.40). The mean pocket probing depth observed at three months, compared to the baseline value, showed a statistically significant difference (P < 0.001) in group A (5.91±0.70 to 2.18±0.40) compared to group B (6.18±0.75 to 4.36±0.50), followed by group C (5.82±0.75 to 5.27±0.64). CONCLUSION: The use of diode laser-assisted pocket disinfection and systemic doxycycline, in addition to scaling and root planing, has proven to be efficient for treating periodontal pockets.

14.
ChemSusChem ; : e202400064, 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38608169

RESUMO

Photocatalytic synthesis of value-added chemicals has gained increasing attention in recent years owing to its versatility in driving many important reactions under ambient conditions. Selective hydrogenation, oxidation, coupling, and halogenation with a high conversion of the reactants have been realized using designed photocatalysts in batch reactors with small volumes at a laboratory scale; however, scaling-up remains a critical challenge due to inefficient utilization of incident light and active sites of the photocatalysts, resulting in poor catalytic performance that hinders its practical applications. Flow systems are considered one of the solutions for practical applications of light-driven reactions and have experienced great success in photolytic and homogeneous photocatalysis, yet their applications in heterogeneous photocatalysis are still under development. In this perspective, we have summarized recent progress in photolytic and photocatalytic synthetic chemistry performed in flow systems from the view of reactor design with a special focus on heterogeneous photocatalysis. The advantages and limitations of different flow systems, as well as some practical considerations of design strategies are discussed.

15.
J Exp Biol ; 227(8)2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38629316

RESUMO

Filter-feeding demosponges are modular organisms that consist of modules each with one water-exit osculum. Once a mature module has been formed, the weight-specific filtration and respiration rates do not change. Sponge modules only grow to a certain size and for a sponge to increase in size, new modules must be formed. However, the growth characteristics of a small single-osculum module sponge are fundamentally different from those of multi-modular sponges, and a theoretically derived volume-specific filtration rate scales as F/V=V-1/3, indicating a decrease with increasing total module volume (V, cm3). Here, we studied filtration rate (F, l h-1), respiration rate (R, ml O2 h-1), volume-specific (F/V) and weight-specific (F/W) filtration rates, and the ratios F/R and F/W along with growth rates of small single-osculum demosponge Halichondria panicea explants of various sizes exposed to various concentrations of algal cells. The following relationships were found: F/V=7.08V-0.24, F=a1W1.05, and R=a2W0.68 where W is the dry weight (mg). The F/R and F/W ratios were constant and essentially independent of W, and other data indicate exponential growth. It is concluded that the experimental data support the theoretical F/V∝V-1/3.


Assuntos
Poríferos , Água , Animais , Respiração , Filtração , Taxa Respiratória
16.
Chemosphere ; 357: 142071, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38641290

RESUMO

To overcome the global water shortage, the treated wastewater is increasingly utilized in agricultural irrigation, and thus reducing freshwater consumption and increasing the water sustainability. Drip irrigation technology is the most appropriate irrigation method to utilize these water sources. However, its operating performance is negatively affected by calcium carbonate (CaCO3) scaling, which is one of the most dominant precipitations and also closely related to dissolved ions and the hydraulic characteristics inside irrigation systems. Thus, the effects of eight common dissolved ions (K+, Mg2+, Mn2+, Zn2+, Fe3+, NO3-, SO42-, and PO43-) in these water sources and four hydraulic shear stresses (0, 0.2, 0.4, and 0.6 Pa) on CaCO3 scaling formation were assessed in this study. Results showed that CaCO3 scaling was primarily formed of calcite and aragonite. Fe3+ would significantly accelerate the CaCO3 scaling accumulation, as it reduced the unit cell volume and chemical bonds of calcite, enhancing calcite adhesion and stability. On the other hand, Mg2+, Mn2+, NO3-, SO42-, and PO43- significantly inhibited CaCO3 scaling. Among them, Mg2+, Mn2+, and PO43- followed the typical water chemical precipitation rule, while NO3- increased water molecule diffusion rate and thus decreased the possibility that Ca2+ and CO32- to precipitate. SO42- grabbed the binding point belonging to CO32- and was adsorbed on the calcite crystal, which inhibited crystal growth. However, those treatments under K+ and Zn2+ did not reach a significant level due to their solubleness. During the precipitation of CaCO3, there were significant (p < 0.01) interactions between dissolved ions and hydraulic shear stresses. When hydraulic shear stresses varied, the effects of Fe3+ and SO42- on the CaCO3 scaling were relatively weakened, while that of Mg2+ was relatively strengthened. In return, dissolved ions affected the effect of hydraulic shear stresses on CaCO3 scaling. Overall, the results obtained could provide theoretical reference for high-efficiency utilization of treated wastewater for agricultural irrigation through the management of CaCO3 scaling.

17.
Methods Mol Biol ; 2787: 333-353, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38656501

RESUMO

X-ray crystallography is a robust and widely used technique that facilitates the three-dimensional structure determination of proteins at an atomic scale. This methodology entails the growth of protein crystals under controlled conditions followed by their exposure to X-ray beams and the subsequent analysis of the resulting diffraction patterns via computational tools to determine the three-dimensional architecture of the protein. However, achieving high-resolution structures through X-ray crystallography can be quite challenging due to complexities associated with protein purity, crystallization efficiency, and crystal quality.In this chapter, we provide a detailed overview of the gene to structure determination pipeline used in X-ray crystallography, a crucial tool for understanding protein structures. The chapter covers the steps in protein crystallization, along with the processes of data collection, processing, structure determination, and refinement. The most commonly faced challenges throughout this procedure are also addressed. Finally, the importance of standardized protocols for reproducibility and accuracy is emphasized, as they are crucial for advancing the understanding of protein structure and function.


Assuntos
Cristalização , Conformação Proteica , Proteínas , Cristalografia por Raios X/métodos , Proteínas/química , Cristalização/métodos , Modelos Moleculares , Software
18.
J Mol Model ; 30(5): 145, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38656715

RESUMO

CONTEXT: A complex supramolecular process involving electrostatic and dispersion interactions and asphaltene aggregation is associated with detrimental petroleum deposition and scaling that pose challenges to petroleum recovery, transportation, and upgrading. The homodimers of seven heterocyclic model compounds, representative of moieties commonly found in asphaltene structures, were studied: pyridine, thiophene, furan, isoquinoline, pyrazine, thiazole, and 1,3-oxazole. The contributions of hydrogen bonding involving water bridges spanning between dimers and π-π stacking to the total interaction energy were calculated and analyzed. The distance between the planes of the aromatic rings is correlated with the π-π stacking interaction strength. All the dimerization reactions were exothermic, although not spontaneous. This was mostly modulated by the strength of the hydrogen bond of the water bridge and the π-π stacking interaction. Dimers bridged by two water molecules were more stable than those with additional water molecules or without any water molecule in the bridge. Energy decomposition analysis showed that the electrostatic and polarization components were the main stabilizing terms for the hydrogen bond interaction in the bridge, contributing at least 80% of the interaction energy in all dimers. The non-covalent interaction analysis confirmed the molecular sites that had the strongest (hydrogen bond) and weak (π-π stacking) attractive interactions. They were concentrated in the water bridge and in the plane between the aromatic rings, respectively. METHODS: The density functional ωB97X-D with a dispersion correction and the Def2-SVP basis set were employed to investigate supramolecular aggregates incorporating heterocycles dimers with 0, 1, 2, and 3 water molecules forming a stabilizing bridge connecting the monomers. The non-covalent interactions were analyzed using the NCIplot software and plotted as isosurface maps using Visual Molecular Dynamics.

19.
Nano Lett ; 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38649277

RESUMO

Liquid confined in a nanochannel or nanotube has exhibited a superfast transport phenomenon, providing an ideal heat and mass transfer platform to meet the increasingly stringent challenge of thermal management in developing high-power-density nanoelectronics and nanochips. However, understanding the thermal transport of confined liquid is currently lacking and is speculated to be fundamentally different from that of bulk counterparts due to the unprecedented thermodynamics of liquid in nanoconfined environments. Here, we report that the thermal conductivity of water confined in a silica nanotube is nearly 2-fold as that of bulk status. Further molecular dynamics simulations reveal that this unusual enhancement originates from the densification and reorientation of local hydrogen bonds close to the nanotubes. Thermal-confinement scaling law is established and quantitatively supported by comprehensive simulations with remarkable agreement. Our findings lay a theoretical foundation for designing nanofluidics-enabled cooling strategies and devices.

20.
Sci Rep ; 14(1): 9265, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38649398

RESUMO

Geometry scaling of microwave circuits is an essential but challenging task. In particular, the employment of a given passive structure in a different application area often requires re-adjustment of the operating frequencies/bands while maintaining top performance. Achieving this necessitates the utilization of numerical optimization methods. Nonetheless, if the intended frequencies are distant from the ones at the starting point, local search procedures tend to fail, whereas global search algorithms are computationally expensive. As recently demonstrated, a combination of large-scale concurrent geometry parameter scaling with intermittent local tuning allows for dependable re-design of high-frequency circuits at low CPU costs. Unfortunately, the procedure is only applicable to single-band structures due to synchronized modifications of all operating bands under scaling. This article discusses a novel procedure that leverages a similar overall concept, but allows for independent control of all center frequencies. To achieve this goal, an automated decision-making procedure is developed in which a set of orthogonal scaling directions are determined based on their effect on individual circuit bands, and using auxiliary optimization sub-problems. The scaling range is then automatically computed by solving an appropriately-defined least-square design relocation problem. The methodology introduced in the work is illustrated using two planar passive devices. In both cases, wide-range operating frequency re-design has been demonstrated and favorably compared to conventional gradient-based tuning. Furthermore, the presented procedure has been shown to be computationally efficient. It is also easy to implement and integrate with a variety of gradient-based optimization procedures of a descent type.

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