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1.
J Acoust Soc Am ; 155(4): 2612-2626, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38629882

RESUMO

This study presents an acoustic investigation of the vowel inventory of Drehu (Southern Oceanic Linkage), spoken in New Caledonia. Reportedly, Drehu has a 14 vowel system distinguishing seven vowel qualities and an additional length distinction. Previous phonological descriptions were based on impressionistic accounts showing divergent proposals for two out of seven reported vowel qualities. This study presents the first phonetic investigation of Drehu vowels based on acoustic data from eight speakers. To examine the phonetic correlates of the proposed phonological vowel inventory, multi-point acoustic analyses were used, and vowel inherent spectral change (VISC) was investigated (F1, F2, and F3). Additionally, vowel duration was measured. Contrary to reports from other studies on VISC in monophthongs, we find that monophthongs in Drehu are mostly steady state. We propose a revised vowel inventory and focus on the acoustic description of open-mid /ɛ/ and the central vowel /ə/, whose status was previously unclear. Additionally, we find that vowel quality stands orthogonal to vowel quantity by demonstrating that the phonological vowel length distinction is primarily based on a duration cue rather than formant structure. Finally, we report the acoustic properties of the seven vowel qualities that were identified.


Assuntos
Fonética , Acústica da Fala , Acústica
2.
Cell Mol Biol (Noisy-le-grand) ; 70(3): 89-94, 2024 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-38650151

RESUMO

The association between the cuproptosis-related genes and the immune infiltration and their prognostic value in thyroid carcinoma is still unexplored. Bioinformatics analyses were performed with data obtained from the TCGA dataset. The aberrantly expressed genes were selected. KEGG and GO analyses were conducted to explore the enriched pathways of the up-regulated or down-regulated genes in thyroid carcinoma. Totally 1495 genes were differentially expressed (691 up-regulated, 804 down-regulated) in thyroid carcinoma (p<0.05). The 10 cuproptosis-related RNAs (DLD, LIAS, LIPT1, FDX1, DLAT, MTF1, PDHA1, CDKN2A, GLS and PDHB) were also demonstrated to be aberrantly expressed in thyroid carcinoma patients tissues. FDX1 expression was correlated with the overall survival in thyroid carcinoma patients (HR=0.4995, 95% CI: 0.2688-0.9285, p=0.0282). Further multivariate cox regression analysis revealed that DLD (HR=24.8869, 95% CI: 4.48772-138.01181, p=0.00024), and LIAS (HR=7.74092, 95% CI: 1.12194-53.40898, p=0.03783) were associated with the survival of thyroid carcinoma patients. The immune infiltration analysis demonstrated that significant correlation between the 10 cuproptosis-related genes and immune infiltration in thyroid carcinoma (p<0.01). We presented the expression profiles of dysregulated genes in thyroid carcinoma. The findings of our study highlighted the potential of cuproptosis-related genes as prognostic biomarkers for thyroid carcinoma.


Assuntos
Regulação Neoplásica da Expressão Gênica , Neoplasias da Glândula Tireoide , Humanos , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/imunologia , Neoplasias da Glândula Tireoide/mortalidade , Neoplasias da Glândula Tireoide/patologia , Prognóstico , Feminino , Masculino , Pessoa de Meia-Idade , Perfilação da Expressão Gênica , Biomarcadores Tumorais/genética , Estimativa de Kaplan-Meier , Modelos de Riscos Proporcionais , Biologia Computacional/métodos
3.
Int J Nurs Stud ; 139: 104446, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36746012

RESUMO

BACKGROUND: High exit rates, stalling entry rates, population ageing, and, most recently, the COVID-19 pandemic have placed significant strain on the world's nursing workforce. Both developed and developing countries face similar predicaments. Evidence-based programmes to support older nurses in the workplace are urgently needed to ensure the sustainability of a career in nursing for this group of healthcare professionals. OBJECTIVES: To scope and synthesise available evidence on evaluated programmes and interventions implemented to support the ageing nursing workforce's health, wellbeing, and retention. DESIGN: A literature review of available evidence using a systematic approach. METHOD: Medline, Scopus, PsycINFO and CINAHL were searched for relevant peer-reviewed evidence. Data from the peer-reviewed literature were extracted separately into purpose designed-extraction spreadsheets. Information relevant to study design, intervention design, outcome constructs, intervention outcomes, and barriers and enablers to intervention success were collected. The protocol for this review was registered in PROSPERO [CRD42021274491]. RESULTS: Eighteen published studies were included in this review. We identified a range of interventions and programmes that have been implemented to support older nurses, which included flexible and reduced work arrangements, mentoring programmes, exercise and lifestyle interventions, continued professional development and purpose-designed remote retreats. We found limited evidence of evaluated outcomes from workplace support interventions that addresses the actual challenges faced by ageing nurses as reported in previous literature reviews. Interventions that were designed to promote a sense of purpose at work resulted in positive outcomes and appeared to more directly address the stated needs of older nurses. Holistic programmes and interventions that could potentially promote both physical well-being and psychological well-being required a broader, whole-of-organisation approach rather than more piecemeal interventions addressing individual physical and mental health concerns. Interventions which acknowledged older nurses' clinical expertise and experience (e.g., mentoring programmes) were linked to positive outcomes. CONCLUSION: Future intervention efforts should acknowledge and balance intervention participation opportunities against existing everyday workload constraints faced by older nurses. Our review suggests the need for further intervention studies assessing specific outcomes such as psychological and emotional health, as well as interventions that more directly address the most pressing concerns that ageing nurses report at personal and organisational levels. A paradigm shift in productivity measurement in clinical nursing work is required in order to increase the value placed on the unique contribution of older nurses working clinically, particularly in sharing their acquired knowledge, skill, and expertise.


Assuntos
COVID-19 , Enfermeiras e Enfermeiros , Humanos , Pandemias , Local de Trabalho/psicologia , Pessoal de Saúde
4.
Int J Speech Lang Pathol ; 25(1): 125-129, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36511655

RESUMO

PURPOSE: To showcase how applications of automatic speech recognition (ASR) technology could help solve challenges in speech-language pathology practice with children with communication disability, and contribute to the realisation of the Sustainable Development Goals (SDGs). RESULT: ASR technologies have been developed to address the need for equitable, efficient, and accurate assessment and diagnosis of communication disability in children by automating the transcription and analysis of speech and language samples and supporting dual-language assessment of bilingual children. ASR tools can automate the measurement of and help optimise intervention fidelity. ASR tools can also be used by children to engage in independent speech production practice without relying on feedback from speech-language pathologists (SLPs), thus bridging the long-standing gap between recommended and received intervention intensity. These innovative technologies and tools have been generated from interdisciplinary partnerships between SLPs, engineers, data scientists, and linguists. CONCLUSION: To advance equitable, efficient, and effective speech-language pathology services for children with communication disability, SLPs would benefit from integrating ASR solutions into their clinical practice. Ongoing interdisciplinary research is needed to further advance ASR technologies to optimise children's outcomes. This commentary paper focusses on industry, innovation and infrastructure (SDG 9) and partnerships for the goals (SDG 17). It also addresses SDG 1, SDG 3, SDG 4, SDG 8, SDG 10, SDG 11, and SDG 16.


Assuntos
Transtornos da Comunicação , Percepção da Fala , Humanos , Criança , Desenvolvimento Sustentável , Transtornos da Comunicação/terapia , Idioma , Fala
5.
Front Psychol ; 13: 981008, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36483708

RESUMO

Characterizing older adult engagement is important to determine the effectiveness of interventions. Engagement refers to the occupying of oneself in external stimuli and is observable across multiple dimensions of behavior. Engagement of older adults is commonly investigated using a single behavioral dimension. There is a dearth of analytical methods that can simultaneously quantify both verbal and non-verbal forms of communication as proxies for engagement. In this article, we present a multidimensional technique to measure engagement of older adults using techniques appropriate for people with varying degrees of dementia. The new analytical approach measures facial movement, lexical use, and prosodic patterns of speech as indices of affective and behavioral outcomes of engagement. Contexts for engagement included a dyadic reminiscence therapy interview and a 12-week technology-driven group reminiscence therapy. Illustrative examples of the technique are described by two participants from two different groups in a naturalistic setting. Application of these analytical techniques can enhance measurement precision and further develop the science and evidence base, especially for, but not confined to, non-pharmacological interventions.

6.
Front Psychol ; 13: 805447, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36176800

RESUMO

In many communities around the world, speech to infants (IDS) and small children (CDS) has increased mean pitch, increased pitch range, increased vowel duration, and vowel hyper-articulation when compared to speech directed to adults (ADS). Some of these IDS and CDS features are also attested in foreigner-directed speech (FDS), which has been studied for a smaller range of languages, generally major national languages, spoken by millions of people. We examined vowel acoustics in CDS, conversational ADS, and monologues directed to a foreigner (possible FDS, labeled MONO here) in the Towet dialect of the Papuan language Nungon, spoken by 300 people in a remote region in northeastern Papua New Guinea. Previous work established that Nungon CDS entails optional use of consonant alteration, special nursery vocabulary, and special morphosyntax. This study shows that Nungon CDS to children aged 2;2-3;10 lacks vowel hyper-articulation, but still displays other common prosodic traits of CDS styles around the world: increased mean pitch and pitch range. A developmental effect was also attested, in that speech to 2-year-olds contained vowels that were significantly longer than those in speech to 3-year-olds, which in turn had vowels of similar duration to those in Nungon ADS. We also found that Nungon FDS vowel triangles, measured from monologues primarily directed to a non-native speaker, were significantly larger than those of either CDS or conversational ADS, indicating vowel hyper-articulation. The Nungon pattern may align with the patterns of vowels in Norwegian IDS, CDS, and FDS, where hyper-articulation is found in FDS, but not CDS or IDS. The languages of the New Guinea area constitute 20% of the world's languages, but neither an acoustic comparison of vowels in CDS and ADS, nor an acoustic study of FDS, has previously been completed for any language of New Guinea. The function of an FDS style in a small, closed community like those of much of New Guinea may differ from that in larger societies, since there are very few non-native speakers of Nungon. Thus, this study uses monologues recorded with a foreign researcher as interlocutor to study Nungon FDS.

7.
JMIR Form Res ; 6(6): e33036, 2022 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-35727623

RESUMO

BACKGROUND: Australians living in rural and remote areas are at elevated risk of mental health problems and must overcome barriers to help seeking, such as poor access, stigma, and entrenched stoicism. e-Mental health services circumvent such barriers using technology, and text-based services are particularly well suited to clients concerned with privacy and self-presentation. They allow the client to reflect on the therapy session after it has ended as the chat log is stored on their device. The text also offers researchers an opportunity to analyze language use patterns and explore how these relate to mental health status. OBJECTIVE: In this project, we investigated whether computational linguistic techniques can be applied to text-based communications with the goal of identifying a client's mental health status. METHODS: Client-therapist text messages were analyzed using the Linguistic Inquiry and Word Count tool. We examined whether the resulting word counts related to the participants' presenting problems or their self-ratings of mental health at the completion of counseling. RESULTS: The results confirmed that word use patterns could be used to differentiate whether a client had one of the top 3 presenting problems (depression, anxiety, or stress) and, prospectively, to predict their self-rated mental health after counseling had been completed. CONCLUSIONS: These findings suggest that language use patterns are useful for both researchers and clinicians trying to identify individuals at risk of mental health problems, with potential applications in screening and targeted intervention.

8.
Int J Speech Lang Pathol ; 24(4): 341-351, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-34612102

RESUMO

Purpose: The Australian English Communicative Development Inventory (OZI) is a 558-item parent report tool for assessing language development at 12-30 months. Here, we introduce the short form (OZI-SF), a 100-item, picture-supported, online instrument with substantially lower time and literacy demands.Method: In tool development (Study 1), 95 items were drawn from the OZI to match its item distribution by age of acquisition and semantic categories. Five items were added from four other semantic categories, plus 12 gestures and six games/routines. Simulations computed OZI-SF scores from existing long-form OZI norm data, and OZI and projected OZI-SF scores were correlated. In an independent norming sample (Study 2), parents (n = 230) completed the OZI-SF for their children aged 12-30 months. Child scores were analysed by age and sex.Result: OZI-SF and OZI scores correlate highly across age and language development levels. Vocabulary scores (receptive, expressive) correlate with age and the median for girls is higher until 24 months. By 24 months, 50% of the sample combine words "often". The median time to OZI-SF completion was 12 minutes.Conclusion: Fitted percentiles permit working guidelines for typical (median) performance and lower cut-offs for children who may be behind on age-based expectations and/or at risk for a communication difficulty. The OZI-SF is a short-form of the OZI that has promise for research and clinical/educational use with Australian families.


Assuntos
Desenvolvimento da Linguagem , Vocabulário , Austrália , Criança , Linguagem Infantil , Comunicação , Feminino , Humanos , Lactente , Idioma
9.
JMIR Ment Health ; 8(2): e19478, 2021 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-33625373

RESUMO

BACKGROUND: People living in rural and remote areas have poorer access to mental health services than those living in cities. They are also less likely to seek help because of self-stigma and entrenched stoic beliefs about help seeking as a sign of weakness. E-mental health services can span great distances to reach those in need and offer a degree of privacy and anonymity exceeding that of traditional face-to-face counseling and open up possibilities for identifying at-risk individuals for targeted intervention. OBJECTIVE: This scoping review maps the research that has explored text-based e-mental health counseling services and studies that have used language use patterns to predict mental health status. In doing so, one of the aims was to determine whether text-based counseling services have the potential to circumvent the barriers faced by clients in rural and remote communities using technology and whether text-based communications, in particular, can be used to identify individuals at risk of psychological distress or self-harm. METHODS: We conducted a comprehensive electronic literature search of PsycINFO, PubMed, ERIC, and Web of Science databases for articles published in English through November 2020. RESULTS: Of the 9134 articles screened, 70 met the eligibility criteria and were included in the review. There is preliminary evidence to suggest that text-based, real-time communication with a qualified therapist is an effective form of e-mental health service delivery, particularly for individuals concerned with stigma and confidentiality. There is also converging evidence that text-based communications that have been analyzed using computational linguistic techniques can be used to accurately predict progress during treatment and identify individuals at risk of serious mental health conditions and suicide. CONCLUSIONS: This review reveals a clear need for intensified research into the extent to which text-based counseling (and predictive models using modern computational linguistics tools) may help deliver mental health treatments to underserved groups such as regional communities, identify at-risk individuals for targeted intervention, and predict progress during treatment. Such approaches have implications for policy development to improve intervention accessibility in at-risk and underserved populations.

10.
J Acoust Soc Am ; 147(4): 2891, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32359261

RESUMO

This study is a comprehensive acoustic description and analysis of the six vowels /i e a u o ɔ/ in the Towet dialect of the Papuan language Nungon ⟨yuw⟩ of northeastern Papua New Guinea. Vowel tokens were extracted from a corpus of audio speech recordings created for general language documentation and grammatical description. To assess the phonetic correlates of a claimed phonological vowel length distinction, vowel duration was measured. Multi-point acoustic analyses enabled investigation of mean vowel F1, F2, and F3; vowel trajectories, and coarticulation effects. The three Nungon back vowels were of particular interest, as they contribute to an asymmetrical, back vowel-heavy array, and /o/ had previously been described as having an especially low F2. The authors found that duration of phonologically long and short vowels differed significantly. Mean vowel formant measurements confirmed that the six phonological vowels form six distinct acoustic groupings; trajectories show slightly more formant movement in some vowels than was previously known. Adjacent nasal consonants exerted significant effects on vowel formant measurements. The authors show that an uncontrolled, general documentation corpus for an under-described language can be mined for acoustic analysis, but coarticulation effects should be taken into account.


Assuntos
Fonética , Acústica da Fala , Acústica , Papua Nova Guiné , Fala
11.
Oncol Lett ; 15(5): 7855-7863, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29725475

RESUMO

Previous years have witnessed the importance of long non-coding RNAs (lncRNAs) in cancer research. The lncRNA Pvt1 oncogene (non-protein coding) (PVT1) was revealed to be upregulated in various cancer types. The aim of the present study was to investigate the function of PVT1 in clear cell renal cell carcinoma (ccRCC). The expression of PVT1 in ccRCC was analyzed using reverse transcription-quantitative polymerase chain reaction, and it was revealed that PVT1 expression was upregulated in ccRCC tissues compared with that in normal adjacent tissues. Next, PVT1 expression from The Cancer Genome Atlas datasets was validated, and it was also revealed that the high expression of PVT1 was associated with advanced disease stage and a poor prognosis. Furthermore, the knockdown of PVT1 induced apoptosis by increasing the expression of poly ADP ribose polymerase and Bcl-2-associated X protein, and promoted cell cycle arrest at the G1 phase by decreasing the expression of cyclin D1. Study of the mechanism involved indicated that PVT1 promoted the progression of ccRCC partly through activation of the epidermal growth factor receptor pathway. Altogether, the results of the present study suggested that PVT1 serves oncogenic functions and may be a biomarker and therapeutic target in ccRCC.

12.
Biochimie ; 148: 46-54, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29501482

RESUMO

A novel extracellular laccase was purified from fermentation broth of the white rot fungus Trametes sp. F1635 by a three-step protocol including two consecutive ion-exchange chromatography steps on DEAE-Sepharose and SP-Sepharose, and a final gel-filtration on Superdex 75. The purified laccase (TsL) was a monomeric protein with the molecular mass of 64.8 kDa. It demonstrated high oxidation activity of 4.00 × 104 U/mg towards ABTS. Its N-terminal amino acid sequence was AIGPVADLTIINNAV which was unique and sharing high similarity of other fungal laccases. TsL was a yellow laccase based on absorption spectrum analysis. It demonstrated an acidic pH optimum of 2.6 and temperature optimum of 50 °C towards ABTS. The Km and Vmax values towards ABTS were estimated to 18.58 µM and 1.35 µmol/min, respectively. TsL manifested effective decolorization activity towards eriochrome black T (EBT), remazol brilliant blue R (RBBR), malachite green (MG), and eriochrome black T (EBT) (over 60%). Violuric acid (VA) and acetosyringone (AS) were the optimal mediators for the laccase in dye decolorization. Results suggest that TsL demonstrates great potential for dye decolorization and water treatment.


Assuntos
Corantes/metabolismo , Espaço Extracelular/enzimologia , Lacase/metabolismo , Trametes/citologia , Sequência de Aminoácidos , Cor , Fermentação , Concentração de Íons de Hidrogênio , Cinética , Lacase/química , Peso Molecular , Temperatura , Trametes/enzimologia
13.
J Acoust Soc Am ; 140(2): 1089, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27586739

RESUMO

Wind instrument players control the initial and final transients of notes using breath, lips, and tonguing. This paper uses a clarinet-playing machine and high-speed camera to investigate how blowing pressure, lip force, and tonguing parameters affect transients. After tongue release, the reed quickly comes to rest, losing its mechanical energy. However, the changing aperture past the reed rapidly changes the airflow. For pressure above the oscillation threshold, successive interactions between reflections of this pulse of airflow and the reed produce an exponential increase in the sound. The rates r of exponential increase in the fundamental of the sound range from several tens to several hundreds of dB s(-1), as functions of blowing pressure and lip force. Because the reed's initial mechanical energy is lost, tongue force and acceleration have little effect on r. However, larger tongue force and acceleration produce more rapid changes in flow, which start notes sooner after tongue release. Further, large tongue force increases the third harmonic during the transient. There is a hysteresis region on the (pressure, lip force) plane where regenerative oscillation is not produced spontaneously by increasing blowing pressure only. Here, tongue action can initiate sustained notes at low pressure.

14.
J Acoust Soc Am ; 139(2): 825-38, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26936564

RESUMO

Articulation, including initial and final note transients, is important to tasteful music performance. Clarinettists' tongue-reed contact, the time variation of the blowing pressure P¯mouth, the mouthpiece pressure, the pressure in the instrument bore, and the radiated sound were measured for normal articulation, accents, sforzando, staccato, and for minimal attack, i.e., notes started very softly. All attacks include a phase when the amplitude of the fundamental increases exponentially, with rates r ∼1000 dB s(-1) controlled by varying both the rate of increase in P¯mouth and the timing of tongue release during this increase. Accented and sforzando notes have shorter attacks (r∼1300 dB s(-1)) than normal notes. P¯mouth reaches a higher peak value for accented and sforzando notes, followed by a steady decrease for accented notes or a rapid fall to a lower, nearly steady value for sforzando notes. Staccato notes are usually terminated by tongue contact, producing an exponential decrease in sound pressure with rates similar to those calculated from the bandwidths of the bore resonances: ∼400 dB s(-1). In all other cases, notes are stopped by decreasing P¯mouth. Notes played with different dynamics are qualitatively similar, but louder notes have larger P¯mouth and larger r.

15.
Oncotarget ; 6(2): 1064-78, 2015 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-25473900

RESUMO

Long intergenic noncoding RNAs (lincRNAs) play important roles in regulating various biological processes in cancer, including proliferation and apoptosis. However, the roles of lincRNAs in bladder cancer remain elusive. In this study, we identified a novel lincRNA, which we termed AATBC. We found that AATBC was overexpressed in bladder cancer patient tissues and positively correlated with tumor grade and pT stage. We also found that inhibition of AATBC resulted in cell proliferation arrest through G1 cell cycle mediated by cyclin D1, CDK4, p18 and phosphorylated Rb. In addition, inhibition of AATBC induced cell apoptosis through the intrinsic apoptosis signaling pathway, as evidenced by the activation of caspase-9 and caspase-3. The investigation for the signaling pathway revealed that the apoptosis following AATBC knockdown was mediated by activation of phosphorylated JNK and suppression of NRF2. Furthermore, JNK inhibitor SP600125 could attenuate the apoptotic effect achieved by AATBC knockdown, confirming the involvement of JNK signaling in the induced apoptosis. Moreover, mouse xenograft model revealed that knockdown of AATBC led to suppress tumorigenesis in vivo. Taken together, our study indicated that AATBC might play a critical role in pro-proliferation and anti-apoptosis in bladder cancer by regulating cell cycle, intrinsic apoptosis signaling, JNK signaling and NRF2. AATBC could be a potential therapeutic target and molecular biomarker for bladder cancer.


Assuntos
Apoptose/genética , Proliferação de Células/genética , Interferência de RNA , RNA Longo não Codificante/genética , Neoplasias da Bexiga Urinária/genética , Ensaios Antitumorais Modelo de Xenoenxerto/métodos , Idoso , Animais , Western Blotting , Linhagem Celular , Linhagem Celular Tumoral , Ciclina D1/genética , Ciclina D1/metabolismo , Quinase 4 Dependente de Ciclina/genética , Quinase 4 Dependente de Ciclina/metabolismo , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Camundongos Endogâmicos NOD , Camundongos SCID , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Carga Tumoral/genética , Neoplasias da Bexiga Urinária/metabolismo , Neoplasias da Bexiga Urinária/patologia
16.
Pest Manag Sci ; 70(7): 1041-7, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24002996

RESUMO

BACKGROUND: Azadirachtin is a botanical pesticide, which possesses conspicuous biological actions such as insecticidal, anthelmintic, antifeedancy, antimalarial effects as well as insect growth regulation. Deterrent for chemoreceptor functions appears to be the main mechanism involved in the potent biological actions of Azadirachtin, although the cytotoxicity and subtle changes to skeletal muscle physiology may also contribute to its insecticide responses. In order to discover the effects of Azadirachtin on the central nervous system (CNS), patch-clamp recording was applied to Drosophila melanogaster, which has been widely used in neurological research. RESULTS: Here, we describe the electrophysiological properties of a local neuron located in the suboesophageal ganglion region of D. melanogaster using the whole brain. The patch-clamp recordings suggested that Azadirachtin modulates the properties of cholinergic miniature excitatory postsynaptic current (mEPSC) and calcium currents, which play important roles in neural activity of the CNS. The frequency of mEPSC and the peak amplitude of the calcium currents significantly decreased after application of Azadirachtin. CONCLUSION: Our study indicates that Azadirachtin can interfere with the insect's CNS via inhibition of excitatory cholinergic transmission and partly blocking the calcium channel.


Assuntos
Drosophila melanogaster/efeitos dos fármacos , Inseticidas/farmacologia , Limoninas/farmacologia , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/fisiologia , Cálcio/metabolismo , Canais de Cálcio/metabolismo , Sistema Nervoso Central/efeitos dos fármacos , Sistema Nervoso Central/fisiologia , Drosophila melanogaster/fisiologia , Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Neurônios/fisiologia
17.
Nanoscale Res Lett ; 8(1): 45, 2013 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-23339353

RESUMO

MnSi~1.7 nanowires (NWs) with a single orientation and a large aspect ratio have been formed on a Si(110) surface with the molecular beam epitaxy method by a delicate control of growth parameters, such as temperature, deposition rate, and deposition time. Scanning tunneling microscopy (STM) was employed to study the influence of these parameters on the growth of NWs. The supply of free Si atoms per unit time during the silicide reaction plays a critical role in the growth kinetics of the NWs. High growth temperature and low deposition rate are favorable for the formation of NWs with a large aspect ratio. The orientation relationship between the NWs and the reconstruction rows of the Si(110) surface suggests that the NWs grow along the 11¯0 direction of the silicon substrate. High-resolution STM and backscattered electron scanning electron microscopy images indicate that the NWs are composed of MnSi~1.7.

18.
Toxicol Lett ; 201(3): 258-63, 2011 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-21251955

RESUMO

Pyrethroid insecticide modulation of the voltage-gated sodium channel (VGSC) is proposed to underlie their effects on neuronal excitability by inhibiting channel inactivation and increasing channel open time. However, some in vitro evidences indicate that target sites other than VGSCs could contribute to pyrethroid disruption of neuronal activity. Cholinergic excitability in Drosophila, as in other insects and mammals, is important for activity in the central nervous system. The effects of permethrin, a putative calcium antagonist, on calcium current and cholinergic mini-synaptic transmission were investigated in the Drosophila brain. At concentration of 2.5µM, permethrin significantly decreased the calcium current and cholinergic mini-synaptic current. However, the permethrin could not antagonize the calcium current completely. Removal of calcium from the external solution produced a significant decrease of cholinergic mini-synaptic transmission. The results are consistent with the hypothesis that permethrin may modulate cholinergic mini-synaptic currents by partially blocking the calcium channel.


Assuntos
Bloqueadores dos Canais de Cálcio , Inseticidas/toxicidade , Sistema Nervoso Parassimpático/efeitos dos fármacos , Permetrina/toxicidade , Sinapses/efeitos dos fármacos , Transmissão Sináptica/efeitos dos fármacos , Animais , Encéfalo/citologia , Encéfalo/efeitos dos fármacos , Cálcio/metabolismo , Drosophila , Fenômenos Eletrofisiológicos , Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Lisina/análogos & derivados , Microscopia de Fluorescência , Neurônios/metabolismo , Técnicas de Patch-Clamp , Pupa , Canais de Sódio/efeitos dos fármacos , Canais de Sódio/metabolismo , Software
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