bluuebunny/crossref_metadata_2025 huggingface dataset:
Combining Computational Fluid Dynamics with a Biokinetic Model for Predicting Ammonia and Phosphate Behavior in Aeration Tanks
Authors: Zima Piotr , Makinia Jacek , Swinarski Marek , Czerwionka Krzysztof
Published: October 2009

The aim of this study was to use computational fluid dynamics for predicting the behavior of reactive pollutants (ammonia and phosphate) in the aerobic zone of the bioreactor located at the Wschod wastewater treatment plant in Gdansk, Poland. The one‐dimensional advection‐dispersion equation was combined with simple biokinetic models incorporating the Monod‐type expressions as source terms for the two pollutants. The problem was solved numerically by a multi‐step splitting technique algorithm. The dispersion coefficient, EL, was estimated using a statistical method and numerical optimization based on experimental data from three tracer studies. With the first method, the values of EL varied within the range 1082 to 1860 m2/h and 695 to 1355 m2/h, respectively, in sections 1 and 2 of the aerobic zone. Except for one case, deviations of the corresponding numerically optimized values of EL did not exceed 14%. The maximum specific rates of nitrification [rn,max,20 = 4.6 g N/(kg VSS·h)] and phosphate uptake [rPupt,max,20 = 13.5 g P/(kg VSS·h)] at T = 20°C were determined based on laboratory batch experiments. With minor adjustments of the kinetic parameters, the model was capable of accurately predicting the longitudinal profiles of ammonia and phosphate in the aerobic zone, and the simulation results were presented using the actual horizontal geometry of the bioreactor as a background.
Surface Area and Travel Time Relationships in Aquifer Treatment Systems
Authors: Fox Peter , Makam Roshan
Published: October 2009

Soil aquifer treatment (SAT) and bank filtration use natural attenuation processes to purify water for subsequent use. Soil aquifer treatment may constitute both unsaturated and saturated flow conditions, while bank filtration systems are primarily saturated flow. This analysis focuses on the saturated zone, where the majority of residence time occurs, in both SAT and bank filtration systems. Sustainable removal mechanisms during subsurface flow are primarily surface‐mediated and therefore depend on surface area. By analyzing saturated subsurface flow hydraulics in granular media, a relationship between surface area and travel time was developed. For saturated subsurface flow, the ratio of surface area‐to‐travel time varied by approximately a factor of 3, for common aquifer materials subject to identical hydraulic gradients. Because travel time criteria often are used to regulate SAT and bank filtration systems, these criteria also may determine the surface area and associated surface‐mediated reactions for water purification. The ratio of surface area‐to‐travel time increases with increasing hydraulic gradient, implying that surface area is relatively constant for specific travel times, even if the hydraulic gradient changes; however, the increasing hydraulic gradient will increase the distance from the recharge zone to the recovery well. Therefore, travel time assessments based on maximum possible hydraulic gradients increase surface area and could provide a conservative limit for surface‐mediated reactions. This analysis demonstrates that travel time criteria for SAT and bank filtration systems indirectly provide a minimum surface area that may support sustainable removal mechanisms.
Detection Limits for Real‐Time Source Water Monitoring Using Indigenous Freshwater Microalgae
Authors: Rodriguez Miguel , Greenbaum Elias
Published: October 2009

This research identified toxin detection limits using the variable fluorescence of naturally occurring microalgae in source drinking water for five chemical toxins with different molecular structures and modes of toxicity. The five chemicals investigated were atrazine, Diuron®, paraquat, methyl parathion, and potassium cyanide. Absolute threshold sensitivities of the algae for detection of the toxins in unmodified source drinking water were measured. Differential kinetics between the rate of action of the toxins and natural changes in algal physiology, such as diurnal photoinhibition, are significant enough that effects of the toxin can be detected and distinguished from the natural variance. This is true even for physiologically impaired algae where diminished photosynthetic capacity may arise from uncontrollable external factors such as nutrient starvation. Photoinhibition induced by high levels of solar radiation is a predictable and reversible phenomenon that can be dealt with using a period of dark adaption of 30 minutes or more.
The Structure of Scientific Titles
Authors: Harmon Joseph E. , Gross Alan G.
Published: October 2009

This article proposes a taxonomy of scientific titles: those staking claims; those setting problems; and those conveying themes. A close analysis of the deep structure of these titles suggests that their goal is the maximization of information content within a short compass, a compression that permits their easy retrieval in computerized searches. Placing these titles into the context provided by Gross, Harmon, and Reidy's Communicating Science suggests further that titles evolved to this point by adapting to changes in systems of information retrieval.
Creating Editorial Authority through Technological Innovation
Authors: Lanier Clinton R.
Published: October 2009

This article considers a case in which editors created for themselves an amount of power and authority within an organization through technological innovation. Using retrospective analysis and e-mail interviews, the author discusses his own previous experience as a technical editor at a U.S. Government-run research facility when electronic editing was introduced and used. The introduction of electronic editing, the author argues, was an example of technological innovation, which, as other researchers have demonstrated, can create authority within an organization.
Breast-Feeding Modulates the Influence of the Peroxisome Proliferator–Activated Receptor-γ (PPARG2) Pro12Ala Polymorphism on Adiposity in Adolescents
Authors: Verier Caroline , Meirhaeghe Aline , Bokor Szilvia , Breidenassel Christina , Manios Yannis , Molnár Dénes , Artero Enrique G. , Nova Esther , De Henauw Stefaan , Moreno Luis A. , Amouyel Philippe , Labayen Idoia , Bevilacqua Noemi , Turck Dominique , Béghin Laurent , Dallongeville Jean , Gottrand Frédéric ,   on behalf of the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) Study Group
Published: October 2009

OBJECTIVE

The peroxisome proliferator–activated receptor-γ2 (PPARG2) Pro12Ala polymorphism has been associated with a higher BMI and a lower risk of type 2 diabetes in adulthood. The association between adiposity and PPARG variants can be influenced by environmental factors such as early growth, dietary fat, and (as recently shown) breast-feeding. The objectives of this study were to assess 1) the influence of the PPARG2 Pro12Ala polymorphism on adiposity markers in adolescents and 2) a possible modulating effect of breast-feeding on these associations.

RESEARCH DESIGN AND METHODS

Data on breast-feeding duration, BMI, and genotypes for the Pro12Ala polymorphism were available for 945 adolescents (mean age 14.7 years). The breast-feeding duration was obtained from parental records. We measured weight, height, waist circumference, and six skinfold thicknesses.

RESULTS

No significant associations between the Pro12Ala polymorphism and any of the above-mentioned anthropometric parameters were found. There were significant interactions between the PPARG2 Pro12Ala polymorphism and breast-feeding with regard to adiposity measurements (all adjusted P < 0.05). Indeed, in children who had not been breast-fed, Ala12 allele carriers had higher adiposity parameters (e.g., Δ BMI +1.88 kg/m2, adjusted for age, sex, and center, P = 0.007) than Pro12Pro adolescents. In contrast, in breast-fed subjects, there was no significant difference between Ala12 allele carriers and Pro12Pro children in terms of adiposity measurements, whatever the duration of breast-feeding.

CONCLUSIONS

Breast-feeding appears to counter the deleterious effect of the PPARG2 Pro12Ala polymorphism on anthropometric parameters in adolescents.
Microvascular function has no menstrual‐cycle‐dependent variation in healthy ovulatory women
Authors: Ketel Iris J.G. , Stehouwer Coen D.A. , Serné Erik H. , Poel Danielle M. , Groot Leonieke , Kager Cathrien , Hompes Peter G.A. , Homburg Roy , Twisk Jos W. , Smulders Yvo M. , Lambalk Cornelis B.
Published: October 2009

Objective: Hyper‐ and hypoestrogenism that persist for a long time can affect vascular and metabolic function. However, it is not clear whether the same is true for subtle sex hormone changes (i.e., during the menstrual cycle).

Methods:Twenty‐one healthy normal‐weight women with regular cycles were studied during the early‐follicular (day 3±2), late‐follicular (day 12±2), and midluteal (day 20±3) phases. Microvascular function was assessed by skin iontophoresis of acetylcholine (ACh) and sodium nitroprusside (SNP), by skin‐capillary recruitment after arterial and venous occlusion (i.e., capillaroscopy), and by Fourier analysis of resting skin laser Doppler flow at rest (i.e., vasomotion). Insulin sensitivity (i.e., homeostasis model assessment) and blood pressure were also determined during the study days.

Results: Three women were excluded from analyses because they were anovulatory. Skin microvascular responses to ACh and SNP, capillary function, vasomotion, insulin sensitivity, and blood pressure did not differ between the three phases (P≥ 0.1). Further, microvascular function did not correlate with plasma‐estrogen levels (r= −0.06−0.2;P≥ 0.2).

Conclusions: Microvascular function does not demonstrate a clear menstrual‐cycle–dependent variation.
Intervention Approach to the Menopausal Women in Rural Bangladesh
Authors: Yasmin Nahid , Sultana Sayeeda , Habib Shahin Akhter Jahan , Khatun Khodeza
Published: October 2009

To compare the level of knowledge about menopause in terms of its cause, problems and care seeking pattern among the rural women after a health education intervention program. It was a cross sectional intervention type study. In the study, the outcome of intervention was obtained by comparing pre intervention and post intervention of same study population to test if there is any difference in knowledge level. The total intervention program was evaluated ranking their answers and found that before the intervention the only 27.8% respondents had some knowledge regarding menopause related problems and 72.2% had no such perception. After intervention it was observed that 49.27% respondents improved their knowledge, statistically it was found significant. The study was conducted to assess and compare the improvement of knowledge of rural women regarding menopause through educational interventions program. From the study findings, it revealed the significant achievement among the respondents regarding the knowledge on menopause, health care seeking behaviour through an educational intervention program imparted to them. The aim of intervention program is that there should be some degree of changes about knowledge, attitude and behaviour. From the intervention program knowledge of the rural women upgraded. Though this study may not necessarily reflect the actual picture. Through the study the intervention program was found very effective which might be replicate in the country through a national program. Key word: Knowledge on menopausal problems, Health care seeking pattern.   DOI: 10.3329/bmj.v38i1.3580 Bangladesh Medical Journal 38(1) 2009 9-14
A Successful Outcome of Twin Pregnancy in Patient with Systemic Lupus Erythematosus - A Case Report
Authors: Akhtar Nahreen , Sultana Sayeeda , Habib Shahin Akhter Jahan
Published: October 2009

A 28 years old lady was admitted in BSMMU with 4th gravida 33 wks. twin pregnancy with preeclampsia and anasarca. She is a known case of SLE for 4 years and was diagnosed at her 3rd pregnancy. At that time her antids DNA titre was 1100IU/ml. She was in prednisolone and aspirin. She was in remission phase and with advice of physician she got pregnancy. She was diagnosed as a case of twin pregnancy at 12 weeks of pregnancy.   DOI: 10.3329/bmj.v38i1.3585 Bangladesh Medical Journal 38(1) 2009 35-36
Nosocomial Infection: General Principles and the Consequences, Importance of its Control and an Outline of the Control Policy - A Review Article
Authors: Khan SA
Published: October 2009

Nosocomial Infections or more commonly known as Hospital Acquired Infection [HAI], in short , may be defined as "Any infection that is being acquired in a hospital, particularly when the source or the risk factor for it is one peculiar to the hospital". The matter of concern is that nosocomial infection or hospital acquired infection at the moment affect not less than 400,000 hospitalized patients at anytime in the world and are direct or contributory causes of death of more than 80,000 cases a year in the U.S.A. alone. Billions of dollars are used annually in the developed countries alone for the control of just these hospital acquired infections alone which reflect another aspect of the magnitude of the problem. The magnitude of the problems of the nosocomial infections in other countries is even more serious and in a developing country like Bangladesh, one could one assume (since there is no established recognized statistics) the pathetic picture in terms of morbidity, mortality as well as the invisible but very valuable economic loss.The other frustrating fact regarding the natural history of Nosocomial or Hospital Acquired Infections is that they can not be eradicated entirely; but many of them can be prevented by proper control measures. In places where control programmes can be implemented, there had been a proven reduction of morbidity and mortality. Furthermore, the money that can be saved by reduction of nosocomial infections is much more used for infection control.   DOI: 10.3329/bmj.v38i2.3576 Bangladesh Medical Journal 38(2) 2009 60-64
Economies Evolve by Energy Dispersal
Authors: Annila Arto , Salthe Stanley
Published: October 2009

Economic activity can be regarded as an evolutionary process governed by the 2nd law of thermodynamics. The universal law, when formulated locally as an equation of motion, reveals that a growing economy develops functional machinery and organizes hierarchically in such a way as to tend to equalize energy density differences within the economy and in respect to the surroundings it is open to. Diverse economic activities result in flows of energy that will preferentially channel along the most steeply descending paths, leveling a non-Euclidean free energy landscape. This principle of 'maximal energy dispersal‘, equivalent to the maximal rate of entropy production, gives rise to economic laws and regularities. The law of diminishing returns follows from the diminishing free energy while the relation between supply and demand displays a quest for a balance among interdependent energy densities. Economic evolution is dissipative motion where the driving forces and energy flows are inseparable from each other. When there are multiple degrees of freedom, economic growth and decline are inherently impossible to forecast in detail. Namely, trajectories of an evolving economy are non-integrable, i.e. unpredictable in detail because a decision by a player will affect also future decisions of other players. We propose that decision making is ultimately about choosing from various actions those that would reduce most effectively subjectively perceived energy gradients.
Microgyroscope Temperature Effects and Compensation-Control Methods
Authors: Xia Dunzhu , Chen Shuling , Wang Shourong , Li Hongsheng
Published: October 2009

In the analysis of the effects of temperature on the performance of microgyroscopes, it is found that the resonant frequency of the microgyroscope decreases linearly as the temperature increases, and the quality factor changes drastically at low temperatures. Moreover, the zero bias changes greatly with temperature variations. To reduce the temperature effects on the microgyroscope, temperature compensation-control methods are proposed. In the first place, a BP (Back Propagation) neural network and polynomial fitting are utilized for building the temperature model of the microgyroscope. Considering the simplicity and real-time requirements, piecewise polynomial fitting is applied in the temperature compensation system. Then, an integral-separated PID (Proportion Integration Differentiation) control algorithm is adopted in the temperature control system, which can stabilize the temperature inside the microgyrocope in pursuing its optimal performance. Experimental results reveal that the combination of microgyroscope temperature compensation and control methods is both realizable and effective in a miniaturized microgyroscope prototype.
Visitors' Motivation for Attending Theme Parks in Orlando, Florida
Authors: Park Kwang-Soo , Reisinger Yvette , Park Cheol-Soo
Published: October 2009

The objective of this study is to identify the major factors that motivate visitors to attend theme parks in Orlando, Florida, and segment visitors by their motivations. A survey of 260 visitors to theme parks in Orlando was conducted. Thirty-five motivational items were factor analyzed.
The six factors that motivated visitors to attend theme parks in Orlando were "Fantasy & myth," "Learning," "Excitement," "Science & technology," "Rides," and "Small-town America." The cluster analysis identified four groups of visitors: "Fantasy seekers," "Thrilling ride seekers,"
"Light enjoyment seekers," and "Science seekers." The multivariate statistics showed significant differences among the four groups of visitors in their motivations for attending the Orlando theme parks. Implications of the study results are discussed.
Enabling Real-Time Video Services over Ad-Hoc Networks Opens the Gates for E-learning in Areas Lacking Infrastructure
Authors: Karlsson Johannes , Anani Adi , Li Haibo
Published: October 2009

In this paper we suggest a promising solution to come over the problems of delivering e-learning to areas with lack or deficiencies in infrastructure for Internet and mobile communication. We present a simple, reasonably priced and efficient communication platform for providing e-learning. This platform is based on wireless ad-hoc networks. We also present a preemptive routing protocol suitable for real-time video communication over wireless ad-hoc networks. Our results show that this routing protocol can significantly improve the quality of the received video. This makes our suggested system not only good to overcome the infrastructure barrier but even capable of delivering a high quality e-learning material.
A New Mobile Learning Adaptation Model
Authors: Hassan Mohamd Hassan , Al-Sadi Jehad
Published: October 2009

This paper introduces a new model for m- Learning context adaptation due to the need of utilizing mobile technology in education. Mobile learning; m-Learning for short; in considered to be one of the hottest topics in the educational community, many researches had been done to conceptualize this new form of learning. We are presenting a promising design for a model to adapt the learning content in mobile learning applications in order to match the learner context, preferences and the educational objectives. Moreover, the proposed model will support the student learning context which is a result of the mobility of m-learning scenarios such as user location, movement, duration of stay, noise level and availability of resources.
Cusp Forms Like Δ
Authors: Cummins C. J.
Published: October 2009

Letfbe a square-free integer and denote by Γ0(f)+the normalizer of Γ0(f) in SL(2, ℝ). We find the analogues of the cusp form Δ for the groups Γ0(f)+.
A Big Picard Theorem for Holomorphic Maps into Complex Projective Space
Authors: Ye Yasheng , Ru Min
Published: October 2009

We prove a big Picard type extension theoremfor holomorphic maps f : X–A → M, where X is a complex manifold, A is an analytic subvariety of X, and M is the complement of the union of a set of hyperplanes in ℙn but is not necessarily hyperbolically imbedded in ℙn.
Dunford–Pettis Properties and Spaces of Operators
Authors: Ghenciu Ioana , Lewis Paul
Published: October 2009

J. Elton used an application of Ramsey theory to show that ifXis an infinite dimensional Banach space, thenc0embeds inX, ℓ1embeds inX, or there is a subspace ofXthat fails to have the Dunford–Pettis property. Bessaga and Pelczynski showed that ifc0embeds inX*, then ℓ∞embeds inX*. Emmanuele and John showed that ifc0embeds inK(X,Y), thenK(X,Y) is not complemented inL(X,Y). Classical results from Schauder basis theory are used in a study of Dunford–Pettis sets and strong Dunford–Pettis sets to extend each of the preceding theorems. The spaceLw*(X*,Y) ofw*–wcontinuous operators is also studied.
Involutions of RA Loops
Authors: Goodaire Edgar G. , Milies César Polcino
Published: October 2009

LetLbe an RA loop, that is, a loop whose loop ring over any coefficient ringRis an alternative, but not associative, ring. Let ℓ ⟼ ℓθdenote an involution onLand extend it linearly to the loop ringRL. An element α ∈RLissymmetricif αθ= α andskew-symmetricif αθ= –α. In this paper, we show that there exists an involution making the symmetric elements ofRLcommute if and only if the characteristic ofRis 2 or θ is the canonical involution onL, and an involution making the skew-symmetric elements ofRLcommute if and only if the characteristic ofRis 2 or 4.
A Comment on “ 𝔭 < t”
Authors: Shelah Saharon
Published: October 2009

Dealing with the cardinal invariants 𝔭 and t of the continuum, we prove that m = p = ℵ2 ⇒ t = ℵ2. In other words, if MAℵ1 (or a weak version of this) holds, then (of course ℵ2 ≤ 𝔭 ≤ t and) 𝔭 = ℵ2 ⇒ 𝔭 = t. The proof is based on a criterion for 𝔭 < t.
A Note on Covering by Convex Bodies
Authors: Gábor Fejes Tóth
Published: October 2009

A classical theorem of Rogers states that for any convex body K in n-dimensional Euclidean space there exists a covering of the space by translates of K with density not exceeding n log n + n log log n + 5n. Rogers’ theorem does not say anything about the structure of such a covering. We show that for sufficiently large values of n the same bound can be attained by a covering which is the union of O(log n) translates of a lattice arrangement of K.
Modular Reduction in Abstract Polytopes
Authors: Monson B. , Schulte Egon
Published: October 2009

The paper studies modular reduction techniques for abstract regular and chiral polytopes, with two purposes in mind: first, to survey the literature about modular reduction in polytopes; and second, to apply modular reduction, with moduli given by primes in ℤ[τ] (with τ the golden ratio), to construct new regular 4-polytopes of hyperbolic types ﹛3, 5, 3﹜ and ﹛5, 3, 5﹜ with automorphism groups given by finite orthogonal groups.
Intuitionistic Fuzzy γ-Continuity
Authors: Hanafy I. M.
Published: October 2009

This paper introduces the concepts of fuzzy γ-open sets and fuzzy γ-continuity in intuitionistic fuzzy topological spaces. After defining the fundamental concepts of intuitionistic fuzzy sets and intuitionistic fuzzy topological spaces, we present intuitionistic fuzzy γ-open sets and intuitionistic fuzzy γ-continuity and other results related topological concepts.
Group Actions on Quasi-Baer Rings
Authors: Jin Hai Lan , Doh Jaekyung , Park Jae Keol
Published: October 2009

A ring R is called quasi-Baer if the right annihilator of every right ideal of R is generated by an idempotent as a right ideal. We investigate the quasi-Baer property of skew group rings and fixed rings under a finite group action on a semiprime ring and their applications to C*-algebras. Various examples to illustrate and delimit our results are provided.
988: It's not just for suicide, it's for substance use too
Authors: Knopf Alison
Published: April 2024

Called the 988 Suicide and Crisis Lifeline, this three‐digit number was launched more than a year ago by the Substance Abuse and Mental Health Services Administration (SAMHSA) to great fanfare. It appeared to everyone to be mainly for suicide prevention. But it is in fact for every crisis, and substance use is included.
Investigation of Micropattern Forming Process on Zr‐4 Alloy Surface Considering Plowing Effects
Authors: Niu Tong , Luo Yang , Luo Yuanxin , Peng Bo , Wang Hao
Published: April 2024

Micropattern forming process is an efficient and low‐cost process for fabricating multifunctional surfaces in electronics, energy, and biomedical products, but this process of creating microdimples on the surface of zirconium alloys has not been investigated. Currently, there are few models describing the micropattern forming process, and these existing models have not considered the effect of roughness on forming. The influence of roughness on micropattern forming process is not to be neglected due to the size effect, especially the plowing effects caused by asperities in surface roughness during sliding process. In this article, a micropattern forming process model is developed by combining a rough plane indentation model and a plowing effects model, and the experimental study of the forming process is conducted, which can quantitatively evaluate the effects of different process parameters and different roughness of forming die on forming process. The applicability range of the developed model is obtained, and the model is capable of predicting the forming process with various process parameters and surface roughness of forming die by comparing the experiment results with the model results, which is of great significance to the design of the forming die and the improvement of the forming process.
One‐Step Synthesis and Deposition of Metal Oxides: NiO Quantum Dots as a Transport Layer for Perovskite Photovoltaics
Authors: Padmanaban Dilli babu , Sadhu Subha , Dsouza Slavia Deeksha , Mushtaq Warda , Holman Zachary , Svrcek Vladimir , Mariotti Davide
Published: April 2024

One‐step synthesis and deposition of nickel oxide quantum dots using a gas‐phase microplasma process is demonstrated and their applicability as a transport layer for solar cell devices is shown. The process uses a solid nickel metal wire as sacrificial electrode, and the concentration of oxygen gas required in the synthesis is investigated. The quantum dots are characterized for physical, chemical, and optical properties and critical process parameters such as the process throughput are also estimated. Direct one‐step deposition directly on perovskite solar cells is carried out using a computer‐controlledx–ystage and the performance of the solar cell device is assessed.
Patterned Quasi‐Liquid Surfaces for Condensation of Low Surface Tension Fluids
Authors: Boylan Dylan , Monga Deepak , Guo Zongqi , Dosawada Pavan Sai , Shan Li , Wang Pengtao , Dai Xianming
Published: April 2024

Extensive research concerns dropwise condensation of low surface tension fluids to promote energy efficiency and decarbonization in thermal energy systems. However, it is challenging as these fluids typically result in filmwise condensation. Drawing inspiration from the Namib desert beetle that enhances condensation through patterned wettability, conventional beetle‐inspired surfaces excel in water condensation but flood when condensing low surface tension fluids. In this work, a patterned quasi‐liquid surface is reported that achieves exceptional dropwise condensation of low surface tension fluids. The surface consists of alternating stripes with low surface energy, that is, a perfluoropolyether (PFPE) and fluorinated quasi‐liquid surface (FQLS), that shows ultralow contact angle hysteresis for ethanol and hexane. The PFPE stripes are slightly more slippery, acting as slippery bridges that accelerate droplet coalescence and removal. It is experimentally demonstrated that the striped PFPE‐FQLS pattern exhibits a heat transfer coefficient 85%, 330%, and 550% higher than that of PFPE, fluorinated silane, and filmwise condensation, respectively. This study reveals that a high contact angle is desired to sustain dropwise condensation, irrespective of contact angle hysteresis. These findings provide a new paradigm for promoting the dropwise condensation of low surface tension fluids and offer valuable insights into surface design for energy sustainability.
Mechanically Robust Reversibly Cross‐Linked Polymers with Closed‐Loop Recyclability for Use in Flexible Printed Circuit Boards
Authors: Wang Wenjie , Lu Xingyuan , Li Yixuan , Li Xiang , Sun Haoxiang , Sun Junqi
Published: April 2024

It remains a huge challenge to efficiently recycle the printed circuit boards (PCBs) because of the diversity and complexity of the PCBs in terms of material composition. The recycling of PCBs highly depends on the design of the polymers that make up the polymer substrates and conductive pastes. Herein, closed‐loop recyclable plastics for use as the polymer substrates and for the preparation of the conductive pastes are fabricated by dynamically cross‐linking phenylboronic acid‐functionalized poly(methylmethacrylate) (PMMA‐B) and poly(urea‐urethane) (PUU‐B) with boroxines. The closed‐loop recyclable plastic, which is denoted as PMMA‐PUU exhibits a breaking strength of 71.0 MPa and Young's modulus of 1.8 GPa. Because of the dynamic nature of boroxines, the PMMA‐PUU0.6 plastic can be depolymerized in the N, N‐dimethylacetamide/ethanol mixture solvent. The depolymerized PMMA and PUU can be efficiently recovered in high yields and purity through their solubility differences in selective solvents. Conductive pastes suitable for printing of electrical circuits are fabricated through complexation of Ag particles with PMMA‐PUU. PCBs composed of PMMA‐PUU substrates and PMMA‐PUU‐based conductive pastes are flexible, healable, and recyclable. The closed‐loop recycling of the PCBs enables the collection of highly purified Ag particles, PMMA‐B, and PUU‐B monomers even when the PCBs are mixed with polymer wastes.
Liquid Metal‐Enhanced Highly Adhesive Electrodes for Multifunctional Epidermal Bioelectronics
Authors: Cao Chunyan , Hou Changshun , Wang Xiong , Lv Dong , Ai Liqing , Feng Yaxiu , Chen Peiran , Wang Xuejiao , He Mingliang , Yao Xi
Published: April 2024

Liquid metal (LM) bioelectronics find widespread uses in healthcare devices and medical implants. However, the current LM‐based electrodes suffer from achieving a combination of features including stable conductivity, high tissue adhesion, stability, good biocompatibility, degradability, and recyclability. In this work, a stable LM electrode is prepared with an extremely high adhesion strength (8.9 MPa), which is tunable in a wide range by introducing an adhesive ureidopyrimidinone (UPy)‐based polymer to harvest the abovementioned properties. With the help of dynamic LM particle‐polymer interactions in the polymer matrix, LMs can not only enhance the adhesion properties but also form a percolated network at a low LM loading (38 vol%) to achieve a high conductance stability (R/R0 = 0.76 at 100% strain). The high adhesion strength provides a highly stable electrical connection with rigid components with a high stretchability of 1154% when mounting a resistor, while a relatively low adhesion makes it a comfortable wounded skin‐interfaced electrode for accelerating wound healing. Taking advantage of their tunable surface adhesion and biocompatibility, the as‐prepared LM electrodes provide a more reliable and friendly approach to the development of healthcare devices.
Natural Killer Cell‐Derived Extracellular Vesicles as Potential Anti‐Viral Nanomaterials
Authors: Lim Siyoung A. , Ho Nathan , Chen Sophia , Chung Eun Ji
Published: April 2024

In viral infections, natural killer (NK) cells exhibit anti‐viral activity by inducing apoptosis in infected host cells and impeding viral replication through heightened cytokine release. Extracellular vesicles derived from NK cells (NK‐EVs) also contain the membrane composition, homing capabilities, and cargo that enable anti‐viral activity. These characteristics, and their biocompatibility and low immunogenicity, give NK‐EVs the potential to be a viable therapeutic platform. This study characterizes the size, EV‐specific protein expression, cell internalization, biocompatibility, and anti‐viral miRNA cargo to evaluate the anti‐viral properties of NK‐EVs. After 48 h of NK‐EV incubation in inflamed A549 lung epithelial cells, or conditions that mimic lung viral infections such as during COVID‐19, cells treated with NK‐EVs exhibit upregulated anti‐viral miRNA cargo (miR‐27a, miR‐27b, miR‐369‐3p, miR‐491‐5p) compared to the non‐treated controls and cells treated with control EVs derived from lung epithelial cells. Additionally, NK‐EVs effectively reduce expression of viral RNA and pro‐inflammatory cytokine (TNF‐α, IL‐8) levels in SARS‐CoV‐2 infected Vero E6 kidney epithelial cells and in infected mice without causing tissue damage while significantly decreasing pro‐inflammatory cytokine compared to non‐treated controls. Herein, this work elucidates the potential of NK‐EVs as safe, anti‐viral nanomaterials, offering a promising alternative to conventional NK cell and anti‐viral therapies.
Folate‐PEG‐PROTAC Micelles for Enhancing Tumor‐Specific Targeting Proteolysis In Vivo
Authors: Ma Junhui , Fang Lei , Sun Zhengjun , Li Meijing , Fan Ting , Xiang Guangya , Ma Xiang
Published: April 2024

Proteolysis targeting chimeras (PROTACs) technology is rapidly developed as a novel and selective medicinal strategy for the degradation of cellular proteins in cancer therapy. However, the applications of PROTACs as heterobifunctional molecules are largely limited by high molecular weight, low bioavailability, poor permeability, insufficient targeting, and low efficacy in vivo. Herein, self‐assembling micelles of FA‐PEG‐PROTAC are designed for cancer cell selective targeting and reductive‐response proteolysis in tumor‐bearing mice. FA‐PEG‐PROTAC is prepared by conjugating folic acid (FA)‐PEG with EGFR‐targeting PROTAC via a disulfide bond. The FA‐PEG‐PROTAC micelles, formed by self‐assembling, are demonstrated to significantly improve tumor targeting efficacy and exhibit excellent anti‐tumor efficacy in the mouse xenograft model compared to the traditional PROTACs. The strategy of applying self‐assembled FA‐PEG‐PROTAC micelles in tumor therapy can not only improve targeted proteolysis efficiency but also broaden applications in the development of PROTAC‐based drugs.
High pH Stability and Ultralong‐Lived Room Temperature Phosphorescence Carbon Dots in Aqueous Environment
Authors: Shi Shuhao , Liu Weifeng , Di Yujie , Xu Yike , Wu Tao , Huang Xiaobo , Wang Meiling , Liu Xuguang
Published: April 2024

Long‐lived room temperature phosphorescence (RTP) materials have many potential applications in areas such as luminescent lighting, biological imaging, and information security owing to their unique optical properties. However, traditional RTP materials are challenged by the fact that their phosphorescence can be easily quenched by dissolved oxygen and solvent‐assisted relaxation, making it difficult for them to emit phosphorescence in aqueous solutions, particularly in extreme pH environments. In this study, a multicolor RTP carbon dot‐based composite material (u‐CDs) is developed with urea and 3‐aminophenylboronic acid as raw materials. This material exhibits ultra‐long phosphorescence emission lifetime and high pH stability by constructing a rigid hydrogen bond network structure in an aqueous environment. The u‐CDs have an optimal emission of 448 nm, a quantum yield of 21.6%, a phosphorescence lifetime of 2.35 s, and an afterglow time of more than 50 s. With such unique properties, u‐CDs have great potential for applications in anti‐counterfeiting, information encryption, and 3D printing.
Bio‐Engineering Yeast Cells Biolenses by Reshaping Intracellular Vacuoles
Authors: Pirone Daniele , D'Agostino Massimo , Lombini Matteo , Cortecchia Fausto , Diolaiti Emiliano , Mongelluzzo Giuseppe , Giugliano Giusy , Bianco Vittorio , Miccio Lisa , Memmolo Pasquale , Ferraro Pietro
Published: April 2024

An intriguing field of research has recently emerged in which biological cells can be demonstrated to behave as photonics devices, such as optical microlenses. This research highlights yeast cells as promising candidates for engineering biolenses with customizable focal properties. Typically serving as positive biolenses due to their quasi‐spherical shape and positive refractive index (RI) contrast, yeast cells can achieve a negative lensing effect by manipulating their intracellular content, without altering their overall morphology. In fact, it shows that exposure to hypotonic conditions induces the formation of a large, roundish vacuole with lower RI values with respect to the surrounding cytoplasm, thus altering the cell's optical properties. This behavior is investigated by using 3D RI tomograms obtained through a holo‐tomographic phase imaging flow cytometry system, demonstrating that the anisotropic nature of yeast cells results in focal properties dependent on their specific orientations in respect to the incident light. Furthermore, Zemax OpticStudio is utilized to perform comprehensive assessments for optical design analysis of the obtained cell biolenses. The methods described here and the related results represent a pioneering investigation of biological cells’ metamorphoses via intracellular content manipulation for biolens applications.
Narrow Band Organic Photodiode with Photoresponse at 808 nm for Photoplethysmography
Authors: Saggar Siddhartha , Shukla Atul , Lo Shih‐Chun , Namdas Ebinazar B.
Published: April 2024

The fabrication and characterization of an all polymers‐based bulk heterojunction type organic photodiode having a narrowband response in the near‐infrared spectral region with full width at half‐maxima of 63 nm is reported. The active layer of the photodiode constitutes a 1:1 (by weight) blend of poly[4,8‐bis(5‐(2‐ethylhexyl)thiophen‐2‐yl)benzo[1,2‐b;4,5‐b']dithiophene‐2,6‐diyl‐alt‐(4‐(2‐ethylhexyl)‐3‐fluorothieno[3,4‐b]thiophene‐)‐2‐carboxylate‐2‐6‐diyl)] (PCE10) and poly{[N,N′‐bis(2‐octyldodecyl)‐naphthalene‐1,4,5,8‐bis(dicarboximide)‐2,6‐diy1]‐alt‐5,5′‐(2,2′‐dithiophene)} (N2200) deposited using solution processing. The device exhibits a linear dynamic range of 35 dB, response speed of 893 kHz, and specific‐detectivity of 109 Jones at 808 nm excitation wavelength. The narrowband response is achieved using the charge collection narrowing mechanism in a 2.7 μm thick junction device.
Polarization‐Enabled Tuning of Anapole Resonances in Vertically Stacked Elliptical Silicon Nanodisks
Authors: Kjellberg Mikko , Vennberg Felix , Ravishankar Ajith Padyana , Anand Srinivasan
Published: April 2024

This work presents the polarization‐dependent behavior of the anapole state in stacked amorphous silicon (a‐Si) nanodisks with elliptical geometries. Using SiO2 as a spacer layer between the a‐Si disks, the high index contrast between these materials can be used to significantly reduce the fabrication complexity of the system compared to traditional methods that require additional etching of the spacers. A novel way of continuous tuning of the electric dipole anapole excitation within elliptical stacked a‐Si nanoresonators is demonstrated. By rotating the incident electric field's polarization angle, the anapole state can be selectively excited at two distinct wavelength positions separated by 80 nm. Experimental results show characteristic dips in the reflectance of the fabricated elliptical a‐Si stacks with wavelength positions between 1135 and 1217 nm depending on the polarization angle of the incident field which is corroborated by FDTD simulations. Through simulating the internal electric field in the resonators and using multipole decomposition, it is shown that the reflectance dips are due to anapole excitation in the individual disks. The capability to excite anapoles at two distinct wavelengths in the same structure has promising implications for the development of tunable sensors, frequency converters, and quantum memory applications.
Cascade Structured Plasmonic Liquid Crystal Biosensor for the Rapid Detection of Harmful Bacteria Dispersed in Potable Water
Authors: Sforza Maria Laura , Petronella Francesca , De Biase Daniela , Zaccagnini Federica , Lim Seok‐In , Butt Usman Akhtar , d'Alessandro Antonio , Godman Nicholas P. , Evans Dean R. , McConney Michael , Jeong Kwang‐Un , De Sio Luciano
Published: April 2024

Pathogenic microorganisms contaminating potable water are a serious water quality concern because they have severe consequences for human and environmental health. Managing water contamination requires the availability of fast and highly sensitive point‐of‐use detection systems responsive to a wide concentration range. In the present work, this goal is achieved by realizing a cascade‐structured biosensor that exploits innovative stimuli‐responsive materials such as gold nanorods (AuNRs) and photosensitive nematic liquid crystals (NLCs). The cascade structure is fabricated by interfacing a glass substrate in a back‐to‐front arrangement, hosting an array of bioactivated AuNRs and an NLC cell. The AuNRs array integrates microfluidic channels, allowing direct water sampling and the analysis of reduced water volumes with high sensitivity. The biosensor combines in the same device two independent optical transducers: a bioactive AuNRs array (plasmonic biosensor), sensitive to refractive index alterations, and an NLC cell that detects the presence of pathogens by responding to light intensity variations. The plasmonic biosensor performs exceptionally well for very low concentrations of bacteria. In contrast, the NLC biosensor works for high‐concentration bacteria, thus providing a cascade‐like detection system able to detect bacteria in a wide concentration range from 10 to 109CFU mL−1.
Interference Lithography‐Based Fabrication of 3D Metallic Mesostructures on Reflective Substrates using Electrodeposition‐Compatible Anti‐Reflection Coatings for Power Electronics Cooling
Authors: Singhal Gaurav , Dewanjee Sujan , Bae Gwangmin , Ham Youngjin , Lohan Danny J. , Lan Kai‐Wei , Li Jiaqi , Gebrael Tarek , Joshi Shailesh N. , Jeon Seokwoo , Miljkovic Nenad , Braun Paul V.
Published: April 2024

A nanostructured copper oxide (nCO) coating which can be electrochemically reduced to copper metal is demonstrated as an anti‐reflection coating, enabling interference lithography of three‐dimensionally structured templates on a surface compatible with subsequent electrodeposition steps. The nCO presents a black needle‐like structure which effectively absorbs the incident radiation during interference lithography. Specular and diffused reflectivity measurements confirm nCO has near‐zero reflectivity from at least UV (350 nm) to near IR (700 nm) wavelengths. A particularly important aspect of the nCO is its ability to be reduced to copper metal, enabling electrodeposition inside porous templates fabricated on the nCO. It is demonstrated electrodeposition of copper within 3D templates defined by interference lithography and proximity field nano‐patterning processes, forming mesostructured metals which enhance two‐phase cooling. The resultant 5 µm thick structures exhibited up to 3 times the critical heat flux and 2 times heat transfer coefficient of bare silicon. The structures are optimized via computational tools including Finite Difference Time Domain (FDTD) and COMSOL Multiphysics. The use of the approach demonstrated here can potentially find application in many areas given the broad importance of mesostructured metals for energy, biomedical, and mechanical applications.
Real‐Time Noise Source Estimation of a Camera System from an Image and Metadata
Authors: Wischow Maik , Irmisch Patrick , Boerner Anko , Gallego Guillermo
Published: April 2024

Autonomous machines must self‐maintain proper functionality to ensure the safety of humans and themselves. This pertains particularly to its cameras as predominant sensors to perceive the environment and support actions. A fundamental camera problem addressed in this study is noise. Solutions often focus on denoising images a posteriori, that is, fighting symptoms rather than root causes. However, tackling root causes requires identifying the noise sources, considering the limitations of mobile platforms. In this work, a real‐time, memory‐efficient, and reliable noise source estimator that combines data‐based and physically based models is investigated. To this end, a deep neural network that examines an image with camera metadata for major camera noise sources is built and trained. In addition, it quantifies unexpected factors that impact image noise or metadata. This study investigates seven different estimators on six datasets that include synthetic noise, real‐world noise from two camera systems, and real‐field campaigns. For these, only the model with most metadata is capable to accurately and robustly quantify all individual noise contributions. This method outperforms total image noise estimators and can be plug‐and‐play deployed. It also serves as a basis to include more advanced noise sources, or as part of an automatic countermeasure feedback loop to approach fully reliable machines.
Intelligent Structure Searching and Designs for Nanoclusters: Effective Units in Atomic Manufacturing
Authors: Gao Junfeng , Zhao Luneng , Chang Yuan , Zhang Yanxue , Qiu Shi , Zhao Yuanyuan , Liu Hongsheng , Zhao Jijun
Published: April 2024

Clusters, an aggregation of several to thousands of atoms, molecules, or ions, are the building blocks of novel functional materials by atomic manufacturing and exhibit excellent applications in catalysis, quantum information, and nanomedicine. The evolution of cluster structures has been studied for many years. Many effective structural search methods, such as genetic algorithm, basin‐hopping, and so on, have been developed. However, the efficient execution of these methods relies on precise energy calculators, such as density functional theory (DFT) calculations. Up to now, limited by computational methods and capabilities, the researches mainly focus on free‐standing clusters, which are different from clusters in practical applications. Recently, the rapid development of big data‐driven machine learning is expected to replace DFT for high‐precision large‐scale computing. In this review, the present cluster search methods and challenges currently faced have been summarized. It is proposed that the development of artificial intelligence has the potential to solve some practical problems including the structural and properties evolution of clusters in complex environment, causing revolutionary developments in the fields of catalysis, quantum information, and nanomedicine based on clusters.
Deep Reinforcement Multiagent Learning Framework for Information Gathering with Local Gaussian Processes for Water Monitoring
Authors: Yanes Luis Samuel , Shutin Dmitriy , Marchal Gómez Juan , Gutiérrez Reina Daniel , Toral Marín Sergio
Published: April 2024

The conservation of hydrological resources involves continuously monitoring their contamination. A multiagent system composed of autonomous surface vehicles is proposed herein to efficiently monitor the water quality. To achieve a safe control of the fleet, the fleet policy should be able to act based on measurements and fleet state. It is proposed to use local Gaussian processes and deep reinforcement learning to jointly obtain effective monitoring policies. Local Gaussian processes, unlike classical global Gaussian processes, can accurately model the information in a dissimilar spatial correlation which captures more accurately the water quality information. A deep convolutional policy is proposed, that bases the decisions on the observation on the mean and variance of this model, by means of an information gain reward. Using a double deep Q‐learning algorithm, agents are trained to minimize the estimation error in a safe manner thanks to a Consensus‐based heuristic. Simulation results indicate an improvement of up to 24% in terms of the mean absolute error with the proposed models. Also, training results with 1–3 agents indicate that our proposed approach returns 20% and 24% smaller average estimation errors for, respectively, monitoring water quality variables and monitoring algae blooms, as compared to state‐of‐the‐art approaches.