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1.
J Hepatol ; 80(6): 928-940, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38336346

RESUMO

BACKGROUND & AIMS: Men are more prone to develop and die from liver fibrosis than women. In this study, we aim to investigate how sex-determining region Y gene (SRY) in hepatocytes promotes liver fibrosis. METHODS: Hepatocyte-specific Sry knock-in (KI), Sry knockout (KO), and Sry KI with platelet-derived growth factor receptor α (Pdgfrα) KO mice were generated. Liver fibrosis was induced in mice by bile duct ligation for 2 weeks or carbon tetrachloride treatment for 6 weeks. In addition, primary hepatocytes, hepatic stellate cells (HSCs), and immortalized cell lines were used for in vitro studies and mechanistic investigation. RESULTS: Compared to females, the severity of toxin- or cholestasis-induced liver fibrosis is similarly increased in castrated and uncastrated male mice. Among all Y chromosome-encoded genes, SRY was the most significantly upregulated and consistently increased gene in fibrotic/cirrhotic livers in male patients and in mouse models. Sry KI mice developed exacerbated liver fibrosis, whereas Sry KO mice had alleviated liver fibrosis, compared to age- and sex-matched control mice after bile duct ligation or administration of carbon tetrachloride. Mechanistically, both our in vivo and in vitro studies illustrated that SRY in hepatocytes can transcriptionally regulate Pdgfrα expression, and promote HMGB1 (high mobility group box 1) release and subsequent HSC activation. Pdgfrα KO or treatment with the SRY inhibitor DAX1 in Sry KI mice abolished SRY-induced HMGB1 secretion and liver fibrosis. CONCLUSIONS: SRY is a strong pro-fibrotic factor and accounts for the sex disparity observed in liver fibrosis, suggesting its critical role as a potentially sex-specific therapeutic target for prevention and treatment of the disease. IMPACT AND IMPLICATION: We identified that a male-specific gene, sex-determining region Y gene (SRY), is a strong pro-fibrotic gene that accounts for the sex disparity observed in liver fibrosis. As such, SRY might be an appropriate target for surveillance and treatment of liver fibrosis in a sex-specific manner. Additionally, SRY might be a key player in the sexual dimorphism observed in hepatic pathophysiology more generally.


Assuntos
Células Estreladas do Fígado , Hepatócitos , Cirrose Hepática , Camundongos Knockout , Proteína da Região Y Determinante do Sexo , Animais , Masculino , Feminino , Camundongos , Cirrose Hepática/genética , Cirrose Hepática/metabolismo , Cirrose Hepática/fisiopatologia , Humanos , Hepatócitos/metabolismo , Proteína da Região Y Determinante do Sexo/genética , Proteína da Região Y Determinante do Sexo/metabolismo , Células Estreladas do Fígado/metabolismo , Caracteres Sexuais , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/genética , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/metabolismo , Tetracloreto de Carbono/toxicidade , Tetracloreto de Carbono/efeitos adversos , Colestase/genética , Colestase/metabolismo , Colestase/fisiopatologia , Modelos Animais de Doenças
3.
Chemistry ; 29(20): e202204060, 2023 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-36622137

RESUMO

A series of side-chain liquid crystalline polymers P4VP(CN-DBE)x , where x is the molar ratio of cyanostilbene (CN-DBE) to poly(4-vinylpyridine) (P4VP) repeating unit, was synthesized based on the intermolecular hydrogen bonding between P4VP and CN-DBE. Their luminescent property, liquid crystalline structure and photo-thermo-electric property were elucidated using photoluminescence spectra, X-ray diffraction, thermal imaging and thermoelectric experiments. With the increase of x, the supramolecular system can be changed from lamellar structure to hexagonal columnar structure. Moreover, the P4VP(CN-DBE)x polymer with columnar structure exhibits more efficient photothermal effect. The temperature of P4VP(CN-DBE)0.6 can rise to 130 °C within 10 s under the irradiation of ultraviolet lamp. In addition, the supramolecular system possesses unique photo-thermo-electric conversion ability, and 25 mA current can be detected in the circuit coupled with the thermoelectric module. This work broadens the potential applications of hydrogen-bonded polymer, and provides a simple and facile strategy to prepare liquid crystalline polymers with photo-thermo-electric property.

4.
Inorg Chem ; 62(5): 2236-2243, 2023 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-36689619

RESUMO

Two zero-dimensional inorganic-organic hybrids, namely, [C4mim][Cd(TCDPPA)3] (1) and [C4mpy][Cd(TCDPPA)3] (2), where (TCDPPA)- = 2,2,2-trichloro-N-(di(pyrrolidin-1-yl)phosphoryl)acetamide, (C4mim)+ = 1-butyl-3-methylimidazolium, and (C4mpy)+ = 1-butyl-4-methylpyridinium, have been synthesized via metathesis reactions and characterized systematically. These ionic cadmium-containing inorganic-organic hybrid compounds are assembled from a bulky organic cation and a complex anion constructed from the chelation of three TCDPPA ligands to one cadmium ion. These compounds possess wide band gaps and emit in the deep-blue region intensely with a quantum yield as high as 34.04%. The success of this work provides a new method for the design and fabrication of high-efficiency blue-emitting materials.

5.
Behav Brain Res ; 439: 114247, 2023 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-36473677

RESUMO

Many human activities require high cognitive performance over long periods, while impairments induced by sleep deprivation influence various aspects of cognitive abilities, including working memory (WM), attention, and processing speed. Based on previous research, vagal nerve stimulation can modulate cognitive abilities, attention, and arousal. Two experiments were conducted to assess the efficacy of transcutaneous auricular vagus nerve stimulation (taVNS) to relieve the deleterious effects of sleep deprivation. In the first experiment, 35 participants completed N-back tasks at 8:00 a.m. for two consecutive days in a within-subject study. Then, the participants received either taVNS or earlobe stimulation (active control) intervention in two sessions at random orders after 24 h of sustained wakefulness. Then, they completed the N-back tasks again. In the second experiment, 30 participants completed the psychomotor vigilance task (PVT), and 32 completed the N-back tasks at 8:00 a.m. on the first and second days. Then, they received either taVNS or earlobe stimulation at random orders and finished the N-back and PVT tasks immediately after one hour. In Experiment 1, taVNS could significantly improve the accuracy rate of participants in spatial 3-back tasks compared to active control, which was consistent with experiment 2. However, taVNS did not specifically enhance PVT performance. Therefore, taVNS could be a powerful intervention for acute sleep deprivation as it can improve performance on high cognitive load tasks and is easy to administer.


Assuntos
Estimulação do Nervo Vago , Humanos , Privação do Sono , Memória de Curto Prazo , Nervo Vago/fisiologia , Cognição
6.
Front Psychiatry ; 13: 1022442, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36440417

RESUMO

Background: Circadian rhythm was involved in the pathogenesis of depression. The detection of circadian genes and white matter (WM) integrity achieved increasing focus for early prediction and diagnosis of major depressive disorder (MDD). This study aimed to explore the effects of PER1 gene polymorphisms (rs7221412), one of the key circadian genes, on the association between depressive level and WM microstructural integrity. Materials and methods: Diffusion tensor imaging scanning and depression assessment (Beck Depression Inventory, BDI) were performed in 77 healthy college students. Participants also underwent PER1 polymorphism detection and were divided into the AG group and AA group. The effects of PER1 genotypes on the association between the WM characteristics and BDI were analyzed using tract-based spatial statistics method. Results: Compared with homozygous form of PER1 gene (AA), more individuals with risk allele G of PER1 gene (AG) were in depression state with BDI cutoff of 14 (χ2 = 7.37, uncorrected p = 0.007). At the level of brain imaging, the WM integrity in corpus callosum, internal capsule, corona radiata and fornix was poorer in AG group compared with AA group. Furthermore, significant interaction effects of genotype × BDI on WM characteristics were observed in several emotion-related WM tracts. To be specific, the significant relationships between BDI and WM characteristics in corpus callosum, internal capsule, corona radiata, fornix, external capsule and sagittal stratum were only found in AG group, but not in AA group. Conclusion: Our findings suggested that the PER1 genotypes and emotion-related WM microstructure may provide more effective measures of depression risk at an early phase.

7.
Zhen Ci Yan Jiu ; 47(10): 938-40, 2022 Oct 25.
Artigo em Chinês | MEDLINE | ID: mdl-36301174

RESUMO

Shu-Mu acupoint combination is commonly employed in acupuncture and moxibustion treatment. In animal experiments, it is difficult to implement such combination because of the uncontrollable features of animals. Therefore, there is an urgent need to design an experimental device to facilitate the operation of acupuncture and moxibustion at Shu-Mu acupoints in rats. The present study designed a device equipped with a fixed plate and a moxibustion frame for rats. The fixed plate and the moxibustion frame with detachable connection can allow acupuncture on the back, chest, and abdomen of rats to meet the requirements of the Shu-Mu acupoint combination. The moxibustion frame is made of universal hose and equipped with moxa clip, which ensures moxibustion in any direction and performs moxibustion on acupoints in the back, chest, and abdomen simultaneously. This device is unique in structure and convenient in operation, with safety and reliability. It is beneficial to the development of animal experiments related to acupuncture and moxibustion of Shu-Mu acupoint combination in the future.


Assuntos
Terapia por Acupuntura , Meridianos , Moxibustão , Ratos , Animais , Pontos de Acupuntura , Reprodutibilidade dos Testes
8.
J Pharm Biomed Anal ; 220: 115030, 2022 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-36088810

RESUMO

A negatively-charged tetraphenylethylene derivative (TPE-SE) was designed and synthesized as turn-on fluorescent sensor for berberine chloride (BBC) detection in aqueous solution. The fluorescent property and detection mechanism were elucidated by UV-vis absorption spectra, photoluminescence spectra, dynamic light scattering experiments. The results reveal that the BBC can lead to aggregation-induced emission of TPE-SE due to the electrostatic interactions, endowing TPE-SE with excellent turn-on detecting ability, high selectivity and sensitivity to BBC. The detection limit is as low as 6.58 × 10-6M. These results should be applicable to fabricate special turn-on fluorescent sensors towards various antibiotics, and it is crucially important for achieving reasonable control and intake of small biomolecules.


Assuntos
Berberina , Alcanossulfonatos , Antibacterianos , Cloretos , Corantes Fluorescentes , Espectrometria de Fluorescência/métodos , Estilbenos , Água
9.
Front Neurosci ; 16: 947236, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35928012

RESUMO

A previous study found that combining transcranial direct current stimulation (tDCS) and transcutaneous auricular vagus nerve stimulation (taVNS) could evoke significantly larger activation on a range of cortical and subcortical brain regions than the numerical summation of tDCS and taVNS effects. In this study, two within-subject experiments were employed to investigate its effects on working memory (WM). In experiment 1, the WM modulatory effects of tDCS over the left dorsolateral prefrontal cortex (DLPFC), taVNS, and simultaneous joint simulation of tDCS over the left DLPFC and taVNS (SJS-L) were compared among 60 healthy subjects. They received these three interventions between the baseline test and post-test in a random manner three times. In spatial 3-back task, there was a significant interaction between time and stimulations in the accuracy rate of matching trials (mACC, p=0.018). MACCs were significantly improved by SJS (p = 0.001) and taVNS (p = 0.045), but not by tDCS (p = 0.495). Moreover, 41 subjects in the SJS group showed improvement, which was significantly larger than that in the taVNS group (29 subjects) and tDCS group (26 subjects). To further investigate the generalization effects of SJS, 72 students were recruited in experiment 2. They received tDCS over the right DLPFC, taVNS, simultaneous joint simulation of tDCS over the right DLPFC and taVNS (SJS-R), and sham stimulation in a random manner four times. No significant results were found, but there was a tendency similar to experiment 1 in the spatial 3-back task. In conclusion, combining tDCS and taVNS might be a potential non-invasive neuromodulation technique which is worthy of study in future.

10.
Quant Imaging Med Surg ; 12(5): 2767-2776, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35502380

RESUMO

Background: Coronary slow flow phenomenon (CSFP) is not uncommon in conventional coronary angiography. A disorder of serum homocysteine (tHcy) metabolism may play a role in the pathogenesis of slow coronary flow. Moreover, elevated tHcy concentration is closely associated with atherosclerosis. We aimed to evaluate the relationship between carotid artery stiffness and serum tHcy levels in patients with CSFP. Methods: This was a case-control study. The study population comprised 146 patients with newly diagnosed stable angina, including 73 patients with CSFP and 73 patients with normal coronary flow. All participants underwent conventional coronary angiography, carotid ultrasonography, and biochemical examination. Results: The carotid artery stiffness parameters of ß index (ß), pressure-strain elastic modulus (Ep), and local pulse wave velocity (PWV) in the CSFP group were significantly higher than those in the control group (ß: 10.75±2.16 vs. 9.02±2.11, P=0.007; Ep: 147.41±41.22 vs. 116.21±39.21, P=0.004; PWV: 7.45±1.23 vs. 6.16±1.20, P=0.003), However, arterial compliance (AC) was lower in the CSFP group than the control group (0.52±0.11 vs. 0.69±0.24, P=0.008). The mean thrombolysis in myocardial infarction (TIMI) frame count and the tHcy concentration in the CSFP group were significantly higher than those in the control group (48.60±1.30 vs. 24.50±3.80, P=0.001; 19.95±4.00 vs. 9.12±2.72, P=0.009). The tHcy concentration was positively correlated with ß (R value =0.494, P<0.0001), Ep (R value =0.469, P<0.0001), and PWV (R value =0.436, P<0.0001), but negatively correlated with AC (R value =-0.230, P=0.022). The predictors of CSFP were tHcy concentration, left PWV, right PWV, left ß index, and right ß index. Among them, the left ß index and right ß index were the best indictors for predicting CSFP. The cutoff values of left ß index, right ß index, left PWV, and right PWV were 9.3, 9.3, 6.7, and 6.6, respectively. Conclusions: Our data showed that serum tHcy levels were elevated in patients with CSFP compared with the control group. Carotid artery stiffness parameters were correlated with tHcy. The best predictors of CSFP were left ß index and right ß index. These findings may contribute to a better understanding of systemic vascular disorders in patients with coronary slow flow, rather than simply attributing such disorders to a single and isolated lesion of the epicardial coronary artery.

11.
Pest Manag Sci ; 78(1): 379-387, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34538026

RESUMO

BACKGROUND: Responses to sex pheromones are commonly antagonized by pheromone components of closely related species. Pheromone antagonism has not been widely explored for phylogenetically distant species that have completely different pheromone components. Yet, pheromone components of sympatrically occurring species may also interfere with each other even if these species are distantly related. Here, the effects of heterospecific pheromones on electrophysiology (electroantennogram, EAG) and behavioral responses were tested on the diamondback moth Plutella xyloslella (Plutellidae) and two sympatric noctuid moth species, Spodoptera litura and Spodoptera exigua, whose larvae also feed on Brassica crops. RESULTS: The sex pheromone blend of P. xyloslella, and its components, did not elicit EAG responses in males of the two noctuid species, while sex pheromone components of the noctuid moths elicited significant EAG responses in P. xyloslella males. In wind tunnel bioassays, both (Z, E)-9, 12-tetradecadienyl acetate (ZE-9,12-14:OAc) and (Z, E)-9, 11-tetradecadienyl acetate (ZE-9,11-14:OAc), sex pheromone components from the noctuid moths, inhibited the upwind flight behavior of P. xyloslella males toward an intraspecific pheromone odor source. In Brassica fields, sex pheromone lures of P. xyloslella did not influence trap catches of the noctuid moths, while P. xyloslella pheromone lures baited with either ZE-9,11-14:OAc or ZE-9,12-14:OAc decreased trap catches of P. xyloslella males in a dose-dependent manner. Trap catches of P. xylostella males were also affected by the proximity of ZE-9,11-14:OAc or ZE-9,12-14:OAc to P. xylostella lures. CONCLUSION: The uni-directional pheromone antagonism by ZE-9,11-14:OAc and ZE-9,12-14:OAc suggests innovative semiochemical-based strategies for the management of P. xyloslella and other economically important pests in Brassica fields. © 2021 Society of Chemical Industry.


Assuntos
Brassica , Mariposas , Atrativos Sexuais , Animais , Masculino , Feromônios , Atrativos Sexuais/farmacologia , Spodoptera
12.
Zhongguo Zhen Jiu ; 41(10): 1166-70, 2021 Oct 12.
Artigo em Chinês | MEDLINE | ID: mdl-34628752

RESUMO

OBJECTIVE: To analyze the rules of acupoint and medication selection of acupoint application therapy for functional constipation (FC) by data mining technology. METHODS: The clinical research literature regarding acupoint application therapy for FC from published to February 26, 2020 was searched in CNKI, VIP, Wanfang, SinoMed and PubMed. The prescriptions were extracted, and by using SPSS24.0 and SPSS Modeler14.0 software, the use of high-frequency acupoints and medication was summarized. The association rule analysis, cluster analysis and core prescription analysis of acupoints and medication were analyzed. RESULTS: A total of 122 prescriptions of acupoint application therapy were included, involving 32 acupoints. The core prescription of acupoints was Tianshu (ST 25), Dachangshu (BL 25), Shenque (CV 8) and Guanyuan (CV 4). The high-frequency meridians mainly included conception vessel, yangming stomach meridian of foot and taiyang bladder meridian of foot. The core prescription of medication was rheum officinale, mirabilite, immature bitter orange, mangnolia officinalis, common aucklandia root and borneol. CONCLUSION: The use of local acupoint and regulating-qi and purgating medication is an important principle of acupoint application therapy for FC.


Assuntos
Terapia por Acupuntura , Meridianos , Pontos de Acupuntura , Constipação Intestinal/tratamento farmacológico , Mineração de Dados , Humanos
13.
Lab Chip ; 21(12): 2372-2382, 2021 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-34128001

RESUMO

We investigate liquid dielectrophoresis (LDEP) to implement field-effect pumps (FEPs) that drive liquids from source, via gate, toward drain electric fields between parallel plates without external pumps or the problem of dead volume. The appropriate gate electric field establishes a wall-less virtual microchannel to transfer the liquid from source to drain with an adjustable flow rate (Q) controlled by the difference of the square of the electric field strength (ΔE2DS). Analogous to field-effect transistors (FETs), the FEPs can operate in a "linear", "transition" or "saturation" region depending on ΔE2GD and ΔE2DS. With a sufficient ΔE2GD and a small ΔE2DS, the FEPs operated in the linear region where Q was linearly proportional to ΔE2DS and inversely proportional to the flow resistance R that was mainly determined by the length (L), width (W) and height (H) of a stable and fully-occupied virtual microchannel. With an insufficient ΔE2GD and a moderate to large ΔE2DS, narrowing, tapering and even pinch-off of virtual microchannels were observed, which increased R and changed the operation into the transition or saturation region. A field-effect stream merger regulating two streams was built based on two FEPs with shared gate and drain electrodes. The versatility of FEPs was demonstrated with preliminary studies on whole blood and particle solutions.


Assuntos
Eletricidade , Eletrodos
14.
Plant Cell Environ ; 41(1): 176-186, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28963730

RESUMO

Volatile terpenoids produced in tea plants (Camellia sinensis) are airborne signals interacting against other ecosystem members, but also pleasant odorants of tea products. Transcription regulation (including transcript processing) is pivotal for plant volatile terpenoid production. In this study, a terpene synthase gene CsLIS/NES was recovered from tea plants (C. sinensis cv. "Long-Men Xiang"). CsLIS/NES transcription regulation resulted in 2 splicing forms: CsLIS/NES-1 and CsLIS/NES-2 lacking a 305 bp-fragment at N-terminus, both producing (E)-nerolidol and linalool in vitro. Transgenic tobacco studies and a gene-specific antisense oligo-deoxynucleotide suppression applied in tea leaves indicated that CsLIS/NES-1, localized in chloroplasts, acted as linalool synthase, whereas CsLIS/NES-2 localized in cytosol, functioned as a potential nerolidol synthase, but not linalool synthase. Expression patterns of the 2 transcript isoforms in tea were distinctly different and responded differentially to the application of stress signal molecule methyl jasmonate. Leaf expression of CsLIS/NES-1, but not CsLIS/NES-2, was significantly induced by methyl jasmonate. Our data indicated that distinct transcript splicing regulation patterns, together with subcellular compartmentation of CsLIS/NE-1 and CsLIS/NE-2 implemented the linalool biosynthesis regulation in tea plants in responding to endogenous and exogenous regulatory factors.


Assuntos
Camellia sinensis/genética , Monoterpenos/metabolismo , Proteínas de Plantas/metabolismo , Splicing de RNA/genética , Acetatos/farmacologia , Monoterpenos Acíclicos , Alquil e Aril Transferases/genética , Alquil e Aril Transferases/metabolismo , Sequência de Bases , Camellia sinensis/efeitos dos fármacos , Camellia sinensis/metabolismo , Ciclopentanos/farmacologia , Flores/efeitos dos fármacos , Flores/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Oxilipinas/farmacologia , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas , Splicing de RNA/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Sesquiterpenos/metabolismo , Frações Subcelulares/metabolismo , Terpenos/metabolismo , Nicotiana/genética
15.
Medicine (Baltimore) ; 96(19): e6834, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28489766

RESUMO

The relationship between hyperinsulinemia and decreased sex hormone-binding globulin (SHBG) levels has been observed in obese adults and children. Weight reduction not only increased insulin sensitivity but also elevated serum SHBG levels in obese adults and children. However, the correlation between the changes in insulin resistance indices and serum SHBG concentration during weight reduction program (WRP) is not fully understood, particularly in obese children. This study is to evaluate whether SHBG level is a potential biomarker that can be used to assess insulin resistance in obese children during a short-term WRP. Forty-eight obese Taiwanese children (11.7 ±â€Š2.2 years; 25 boys and 23 girls) participating in 8-week WRP were studied. Anthropometric measurements, lipid profiles, insulin resistance indices, and serum SHBG concentration were recorded at baseline and at the end of the WRP. The results showed body weight (BW), body mass index (BMI), body fat percentage (BF%), body fat weight (BFW), and insulin resistance indices such as fasting insulin, fasting insulin to glucose ratio, homeostasis model assessment (HOMA) of insulin resistance, log (HOMA) all significantly decreased after the 8-week WRP. With respect to lipid profiles, only high-density lipoprotein cholesterol (HDL-C) levels increased in both sexes. At baseline, insulin resistance indices were inversely correlated with SHBG concentrations in girls, but not in boys. The difference in SHBG after WRP was 2.58 nmol/L (95% confidence interval [CI]: -3.51, 8.66) in boys and 0.58 nmol/L (95% CI: -5.23, 6.39) in girls. There was a trend toward increased serum SHBG levels in boys (P = .39) and girls (P = .84) after weight loss, but a significantly negative correlation between the change in SHBG and in each of the insulin resistance indices only in the girls after adjusting age and ΔBFW during WRP.In conclusion, short-term WRP has the potential effects of decreased BW, BMI, BF%, and BFW, as well as increased serum HDL-C levels and insulin sensitivity in obese Taiwanese children. Although serum SHBG levels moderately increased in both sexes during short-term WRP, measuring the change in SHBG concentrations might be a potential biomarker to evaluate improvement in insulin resistance in girls only, and not in boys.


Assuntos
Obesidade/sangue , Obesidade/terapia , Caracteres Sexuais , Globulina de Ligação a Hormônio Sexual/metabolismo , Programas de Redução de Peso , Antropometria , Biomarcadores/sangue , Criança , HDL-Colesterol/sangue , Feminino , Humanos , Resistência à Insulina/fisiologia , Masculino , Taiwan , Resultado do Tratamento , Redução de Peso/fisiologia
16.
Biomed Eng Online ; 14: 109, 2015 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-26611649

RESUMO

BACKGROUND: Microelectrode array (MEA) devices are frequently used in neural circuit studies, especially in retinal prosthesis. For a high throughput stimulation and recording paradigm, it is desirable to obtain the responses of multiple surface RGCs initiated from the electrical signals delivered to multiple photoreceptor cells. This can be achieved by an high density MEA-tissue-MEA (MTM) sandwich configuration. However, the retina is one of the most metabolically active tissues, consumes oxygen as rapidly as the brain. The major concern of the MTM configuration is the supply of oxygen. METHODS: We aimed to develop a high density MTM sandwich platform which consists of stacks of a stimulation MEA, retinal tissue and a recording MEA. Retina is a metabolically active tissue and the firing rate is very sensitive to oxygen level. We designed, simulated and microfabricated porous high density MEAs and an adjustable perfusion system that electrical signals can be delivered to and recorded from the clipped retinal tissue. RESULTS: The porous high-density MEAs linked with stimulation or recording devices within a perfusion system were manufactured and the MTM platform was assembled with a retina slice inside. The firing rate remained constant between 25 and 55 min before dramatically declined, indicating that within certain period of time (e.g. 30 min after habituation), the retina condition was kept by sufficient oxygen supply via the perfusion holes in the MEAs provided by the double perfusion system. CONCLUSIONS: MTM sandwich structure is an efficient platform to study the retinal neural circuit. The material and arrangement of high density microelectrodes with porous design make this MEA appropriate for sub-retina prosthesis. Finding ways to prolong the recording time and reduce the signal-to-noise ratio are important to improve our MTM prototype.


Assuntos
Rede Nervosa/citologia , Retina/citologia , Animais , Difusão , Estimulação Elétrica , Desenho de Equipamento , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microeletrodos , Rede Nervosa/metabolismo , Rede Nervosa/fisiologia , Oxigênio/metabolismo , Retina/metabolismo , Retina/fisiologia , Próteses Visuais
17.
ScientificWorldJournal ; 2014: 180590, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24995351

RESUMO

Issues about opinion diffusion have been studied for decades. It has so far no empirical approach to model the interflow and formation of crowd's opinion in elections due to two reasons. First, unlike the spread of information or flu, individuals have their intrinsic attitudes to election candidates in advance. Second, opinions are generally simply assumed as single values in most diffusion models. However, in this case, an opinion should represent preference toward multiple candidates. Previously done models thus may not intuitively interpret such scenario. This work is to design a diffusion model which is capable of managing the aforementioned scenario. To demonstrate the usefulness of our model, we simulate the diffusion on the network built based on a publicly available bibliography dataset. We compare the proposed model with other well-known models such as independent cascade. It turns out that our model consistently outperforms other models. We additionally investigate electoral issues with our model simulator.


Assuntos
Atitude , Simulação por Computador , Modelos Teóricos , Política , Apoio Social , Humanos
18.
Lab Chip ; 14(15): 2728-38, 2014 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-24899133

RESUMO

For diverse material phases used on an electro-microfluidic (EMF) platform, exploiting the electro-optical properties of matter in varied phases is essential to reap the benefits of the optofluidic capabilities of that platform. Materials in the four fundamental phases--solid-phase dielectric layer, liquid-phase droplet, gas-phase bubble, and plasma-phase bubble microplasma--have been investigated to offer electrically tunable optical characteristics for the manipulation of fluids on an EMF platform. Here we present an overview of the basic driving mechanisms for electrowetting and dielectrophoresis on the EMF platform. Three optofluidic examples occurring in multiple phases are described: solid optofluidics--liquid and light regulation by electrowetting on a solid polymer dispersed liquid crystal (PDLC) dielectric layer; liquid optofluidics--transmittance and reflectance modulation with formation of particle chains in a liquid droplet; and gas and plasma optofluidics--ignition and manipulation of a bubble microplasma by liquid dielectrophoresis. By combining the various materials possessing diverse electro-optical characteristics in separate phases, the EMF platform becomes an ideal platform for integrated optofluidics.

19.
PLoS One ; 8(7): e68756, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23874751

RESUMO

Third instar larvae of the cotton bollworm (Helicoverpa armigera) were reared with artificial diet containing a Bacillus thuringiensis-abamectin (BtA) biopesticide mixture that resulted in 20% mortality (LD20). The adult male survivors from larvae treated with BtA exhibited a higher percentage of "orientation" than control males but lower percentages of "approaching" and "landing" in wind tunnel bioassays. Adult female survivors from larvae treated with BtA produced higher sex pheromone titers and displayed a lower calling percentage than control females. The ratio of Z-11-hexadecenal (Z11-16:Ald) and Z-9-hexadecenal (Z9-16:Ald) in BtA-treated females changed and coefficients of variation (CV) of Z11-16:Ald and Z9-16:Ald were expanded compared to control females. The peak circadian calling time of BtA-treated females occurred later than that of control females. In mating choice experiment, both control males and BtA-treated males preferred to mate with control females and a portion of the Bt-A treated males did not mate whereas all control males did. Our Data support that treatment of larvae with BtA had an effect on the sex pheromone communication system in surviving H. armigera moths that may contribute to assortative mating.


Assuntos
Bacillus thuringiensis/metabolismo , Inseticidas/farmacologia , Ivermectina/análogos & derivados , Larva/efeitos dos fármacos , Mariposas/efeitos dos fármacos , Mariposas/metabolismo , Atrativos Sexuais/fisiologia , Comunicação Animal , Animais , Feminino , Ivermectina/farmacologia , Masculino , Preferência de Acasalamento Animal , Mariposas/microbiologia
20.
Nanotechnology ; 23(1): 015303, 2012 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-22155926

RESUMO

We demonstrate the effect of the pre-growth heat treatment process on the nucleation properties of Ge dots grown on pit-patterned Si(001) substrates. The prefabricated 200 nm diameter pits inherently evolve into truncated inverted pyramids (TIPs) with (110) base edges and a 7°-9° sidewall slope during heat treatment; this morphology transformation is robust against variations in shape and orientation of the pit patterns. Uniform Ge dots with an areal density of 4 × 10(9) cm(-2) were obtained on the Si substrates having TIPs. Each TIP contains four aligned Ge dots locating symmetrically with respect to (110). These dots exhibit an elliptical dome shape with major axis oriented along (100). The nucleation position, shape and spatial orientation of these Ge dots coincide with the calculated surface chemical potential distribution of the TIP.

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