In this study, MCM-41 mesoporous silica nanoparticles were successfully synthesized by the condensation of a tetraorthosilicate precursor on a template self-assembled by cetyltrimethylammonium ...bromide in alkaline. The small-angle x-ray diffraction patterns of MCM-41 indicate that silica nanoparticles possess hexagonal structures with a high degree of structural ordering. Transmission electron microscopy images show that the size of the MCM-41 particles is around 100-120 nm, and the pore sizes range from 2 nm to 4 nm. In addition, the specific surface area of MCM-41 obtained by Brunauer–Emmett–Teller analysis is as high as 987 m
2
.g
−1
and the pore size extracted from nitrogen physical adsorption isotherms is in accordance with the TEM result. Thermogravimetric analysis, Fourier-transform infrared spectroscopy, Zeta potential measurements and photoluminescence measurements show that 3-aminopropyltriethoxysilane (APTES) and doxorubicin were grafted and loaded successfully onto MCM-41 nanoparticles. An assay on fibroblasts, A549 and doxorubicin-resistant A549/DOX cells indicates that the prepared MCM41 grafting APTES nanoparticles are safe to normal cells and toxic to cancer cells
in vitro
.
Graphic abstract
The question of how children learn Function Words (FWs) is still a matter of debate among child language researchers. Are early multiword utterances based on lexically specific patterns or rather ...abstract grammatical relations? In this corpus study, we analyzed FWs having a highly predictable distribution in relation to Mean Length Utterance (MLU) an index of syntactic complexity in a large naturalistic sample of 315 monolingual French children aged 2 to 4 year-old. The data was annotated with a Part Of Speech Tagger (POS-T), belonging to computational tools from CHILDES. While eighteen FWs strongly correlated with MLU expressed either in word or in morpheme, stepwise regression analyses showed that subject pronouns predicted MLU. Factor analysis yielded a bifactor hierarchical model: The first factor loaded sixteen FWs among which eight had a strong developmental weight (third person singular verbs, subject pronouns, articles, auxiliary verbs, prepositions, modals, demonstrative pronouns and plural markers), whereas the second factor loaded complex FWs (possessive verbs and object pronouns). These findings challenge the lexicalist account and support the view that children learn grammatical forms as a complex system based on early instead of late structure building. Children may acquire FWs as combining words and build syntactic knowledge as a complex abstract system which is not innate but learned from multiple word input sentences context. Notably, FWs were found to predict syntactic development and sentence complexity. These results open up new perspectives for clinical assessment and intervention.
The primary objective of this paper is to develop an appropriate predictive formula for the compressive strength of pervious concrete, which depends on its mixture. This will allow for the ...improvement of the proportioning procedure that considers both the target porosity and target compressive strength. To achieve this, an effective computational strategy is first constructed and investigated for the creation of simple and easily applicable symbolic regression functions within the Genetic Programming-based Symbolic Regression framework. Recent advancements in fast logical parallelism and model-based algorithms are also applied to perform calculations on a large quantity of examples, with the aim of finding the most suitable analytical solutions at a low computational cost. Next, to assess the effectiveness of this model in predicting the compressive strength of concrete in general, computations are carried out using the well-known Yeh's dataset on conventional concrete compressive strength. This dataset has been extensively studied using both "black-box" and "white-box" machine learning algorithms. The results reveal that more suitable formulas can be generated through this computational process, compared to several scenarios discussed in the literature. Furthermore, the model is extended to pervious concrete, based on the dataset of 164 samples of 28-day compressive strength collected from 14 different sources. The findings for pervious concrete exhibited high accuracy compared to the most effective black-box models and micromechanical/empirical models, with a coefficient of determination of approximately 0.9 for simple predictive equations, thereby supporting the effectiveness of the proposed approach.
Background
One of the most consistent findings reported in the paediatric cochlear implant (CI) literature is the heterogeneity of language performance observed more in grammatical morphology than in ...lexicon or pragmatics. As most of the corpus studies addressing these issues have been conducted in English, it is unclear whether their results can be generalized to other languages. In particular, little is known about languages known for their grammatical complexity, such as French.
Aims
The aim of this corpus study was to compare the productive use of function words (FWs) and some agreement features (AGRs) in children with CIs and children with typical development (TD) matched for mean length of utterance in words (MLUwords), a general index of grammatical complexity, and auditory experience, as measured by hearing age (HA) and chronological age (CA), respectively.
Methods & Procedures
Natural speech samples from 116 monolingual French‐speaking children, including 40 children with CIs followed longitudinally and 76 TD children, were collected. FWs and AGRs were analysed using a Part of Speech Tagger (POS‐T) from the Child Language Data Exchange System (CHILDES).
Outcomes & Results
The two groups differed by 3 years for HA and CA. No effect of family socio‐economic status (SES) was found in the CI group. Stepwise regression analyses showed that the two groups did not share the same predictors of MLUwords: plurals and determiners predicted MLUwords in children with CIs, at 2 and 3 years of HA, whereas feminine markers and subject‐pronouns were found to best predict MLUwords in TD children at 2 and 3 years of CA. Structural equation models (SEMs), a combination of confirmatory factor analysis (CFA) and path analysis, yielded a different hierarchical structure of grammatical relations (GRs). Selective difficulties affecting verbal clitics and other pronominal forms were found specifically in the CI group (object‐pronouns, reflexive, relative and past participles). Dependency grammar analysis confirmed these contrasting developmental profiles in multiword utterances, such as preposition/nouns, subject/verbs, and verb/determiner/nouns.
Conclusions & Implications
Atypical grammatical patterns in children with CIs reflect a specific architecture of syntactic dependencies of FWs underpinning morphological complexity and syntactic connectivity. Clinical implications are discussed for assessment and intervention planning.
What This Paper Adds
What is already known on this subject
The productive use of FWs has been identified as a particular area of weakness in children with CIs compared with TD children. In addition, heterogenous grammatical performance has often been found after 1–3 years of CI use, regardless of demographic factors such as age at implantation, duration of deafness or SES.
What this paper adds to existing knowledge
Assessing the early building of FWs and AGRs in children with CIs helps to understand the syntactic complexity and hierarchical structure of their language. Since most corpus studies on grammatical morphology have been conducted in English, it is not clear whether their difficulties can be generalized to other languages. The French language has a system of FWs and inflections that determine the morphophonological properties of nominal and verbal forms. Early grammar learning in children with CIs born with profound deafness were compared with the two groups of TD children matched both for duration of auditory experience (i.e., HA of CI children, CA of TD children) and for MLUwords. We found a similar profile between groups at 2 years but not at 3 years for HA and CA. The two groups do not share the same predictors of MLUwords: namely, plurals and determiners for CI children versus feminine markers and subject pronouns for TD children. They show a different syntactic organization of GRs. Children with CIs struggle with selective difficulties affecting verbal clitics and pronominal forms (object‐pronouns, reflexive, relative and past participles). Consistent with theories of morphophonological richness and syntactic connectivity, our results support the distributional learning hypothesis of language acquisition that infants and toddlers are sensitive to FWs and AGRs at an early age. Specific components of syntactic organization are disrupted in children with CIs.
What are the potential or actual clinical implications of this work?
This work has potential clinical implications because it unravels the limitations of morphophonological processing in children with CIs. Its results highlight a specific difficulty in learning FWs and AGRs in a verbal inflectional morphology context.
In this study, heterogeneous catalytic ozonation using fly ash (FA) modified ZnO nanoparticles to the decolorization of acid orange II (AOII) was studied. The combination of ZnO and fly ash via an ...incipient wetness impregnation method to form ZOFA composites created a synergistic effect that led to efficient catalytic ozonation activity towards AOII degradation and decolorization compared with individual ozonation processes. From the experimental results, ZOFA composite with the optimal weight ratio between ZnO NPs and FA was 20 wt% (denoted as ZOFA-20) that exhibited outstanding catalytic ozonation activity. Moreover, through other investigations including initial pH conditions and catalyst dosage, AOII could be effectively and optimally eliminated by 0.5 g of ZOFA-20 with an initial pH value of 11. The corresponding
k
value was measured as 0.248 min
−1
with a maximum TOC removal content of 77.27%. Besides, ZOFA-20 could show high catalytic ozonation activity even at highly concentrated AOII concentrations while it could also retain its excellent stability and reusability over 5 continuous AOII removal cycles. From the experimental and electron paramagnetic resonance (EPR) results, hydroxyl radical (
·
OH) was the main active species during the catalytic ozonation of AOII. The present study provides a promising approach to prepare novel composite-based fly ash that would be applicable for removing azo dye and other dye pollutants in water via a catalytic ozonation strategy.
Despite the discovery of several closely related viruses in bats, the direct evolutionary progenitor of SARS-CoV-2 has not yet been identified. In this study, we investigated potential animal sources ...of SARS-related coronaviruses using archived specimens from Sunda pangolins (
) and Chinese pangolins (
) confiscated from the illegal wildlife trade, and from common palm civets (
) raised on wildlife farms in Viet Nam. A total of 696 pangolin and civet specimens were screened for the presence of viral RNA from five zoonotic viral families and from Sarbecoviruses using primers specifically designed for pangolin coronaviruses. We also performed a curated data collection of media reports of wildlife confiscation events involving pangolins in Viet Nam between January 2016 and December 2020, to illustrate the global pangolin supply chain in the context of Viet Nam where the trade confiscated pangolins were sampled for this study. All specimens from pangolins and civets sampled along the wildlife supply chains between February 2017 and July 2018, in Viet Nam and tested with conventional PCR assays designed to detect flavivirus, paramyxovirus, filovirus, coronavirus, and orthomyxovirus RNA were negative. Civet samples were also negative for Sarbecoviruses, but 12 specimens from seven live pangolins confiscated in Hung Yen province, northern Viet Nam, in 2018 were positive for Sarbecoviruses. Our phylogenetic trees based on two fragments of the RdRp gene revealed that the Sarbecoviruses identified in these pangolins were closely related to pangolin coronaviruses detected in pangolins confiscated from the illegal wildlife trade in Yunnan and Guangxi provinces, China. Our curated data collection of media reports of wildlife confiscation events involving pangolins in Viet Nam between January 2016 and December 2020, reflected what is known about pangolin trafficking globally. Pangolins confiscated in Viet Nam were largely in transit, moving toward downstream consumers in China. Confiscations included pangolin scales sourced originally from Africa (and African species of pangolins), or pangolin carcasses and live pangolins native to Southeast Asia (predominately the Sunda pangolin) sourced from neighboring range countries and moving through Viet Nam toward provinces bordering China.
Topographies of speech auditory brainstem response (speech ABR), a fine electrophysiological marker of speech encoding, have never been described. Yet, they could provide useful information to assess ...speech ABR generators and better characterize populations of interest (e.g., musicians, dyslexics). We present here a novel methodology of topographic speech ABR recording, using a 32‐channel low sampling rate (5 kHz) EEG system. Quality of speech ABRs obtained with this conventional multichannel EEG system were compared to that of signals simultaneously recorded with a high sampling rate (13.3 kHz) EEG system. Correlations between speech ABRs recorded with the two systems revealed highly similar signals, without any significant difference between their signal‐to‐noise ratios (SNRs). Moreover, an advanced denoising method for multichannel data (denoising source separation) significantly improved SNR and allowed topography of speech ABR to be recovered.
Poor sleep quality is recognized as a major risk factor for poor health, increasing the incidence of serious chronic diseases. In people with Down syndrome, sleep apnea prevalence is significantly ...greater, it is caused by genetic, anatomical, endocrine, and metabolic abnormalities. The consequences of sleep disruption due to sleep apnea are very serious, especially in terms of neurocognitive and cardiovascular effects, leading to reduced life expectancy and quality of life in this population. However, the management, care, and treatment of related disorders in people with Down syndrome are still inadequate and limited. Therefore, this article wants to increase understanding and awareness about sleep apnea and the benefits of physical activity in improving sleep quality in the Down syndrome community, families, and their care specialists.
This paper presents the thermoluminescence properties of K2GdF5:Tb material irradiated in a reference neutron-gamma field and its possibility to be used in neutron dosimetry. Double fluoride of ...K2GdF5 doped with 10 at% Tb3+ ions was synthesized under solid-state reaction conditions and irradiated in the reference neutron-gamma field of 241Am-Be source. The thermoluminescence glow curves were measured by the Rexon UL-320 TLD reader connected with the WinRex-320 processing program for obtaining the integrated thermoluminescence signals (counts). The results show that the temperature peaks of the irradiated K2GdF5:Tb material concerning the gamma and neutron fields at the distance of 100 cm from the source are at 230?C and 300?C, respectively. The sensitivity ratios of fast-to-thermal neutron and gamma-to-thermal neutron are 6.3 % and 18.2 %, respectively. The batch homogeneity and reproducibility are less than 30 % and 7.5 %, respectively. The linearity is less than 10 % in the dose range of less than 24 mSv. The detection threshold is less than 0.1 mSv, and the fading is 10.7 % after 90 days of irradiation. These thermoluminescence properties of K2GdF5:Tb material considerably satisfy the requirements to be used in neutron dosimetry.
Background: The microphone is the first link of the sound processing chain and if there is dirt on the membrane or in the input port, the frequency response is modified.
Objective: The effect of ...microphone cleaning in cochlear implants (CI) was studied by measuring speech perception scores in the noise of CI users and of normal hearing (NH) subjects with a CI simulator.
Material and methods: Sixty-one adult CI users and 20 NH were tested. In CI subjects, speech comprehension scores in noise were compared before and after cleaning microphone ports with one of two different cleaning procedures. NH listeners were tested using a vocoder that simulated soiled microphones. Two main coding schemes were considered, channel-picking (CP) and fixed-channel (FC).
Results: With NH subjects, the effect of the coding strategy and degree of soiling was statistically significant (p < 10
−4
); for the intermediate signal to noise ratios (SNRs), the recognition percentages were clearly affected. With CI users, cleaning the microphones significantly improved the recognition scores (p < 10
−4
). The two cleaning procedures considered turned out to be significantly different (p < 10
−4
).
Conclusions: It is suggested to perform a regular microphone port cleaning to avoid deep soiling which leads to a decrease in speech understanding.
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