Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
1.
Nano Lett ; 22(7): 2725-2733, 2022 Apr 13.
Artículo en Inglés | MEDLINE | ID: mdl-35293751

RESUMEN

In van der Waals (vdW) heterostructures, the interlayer electron-phonon coupling (EPC) provides one unique channel to nonlocally engineer these elementary particles. However, limited by the stringent occurrence conditions, the efficient engineering of interlayer EPC remains elusive. Here we report a multitier engineering of interlayer EPC in WS2/boron nitride (BN) heterostructures, including isotope enrichments of BN substrates, temperature, and high-pressure tuning. The hyperfine isotope dependence of Raman intensities was unambiguously revealed. In combination with theoretical calculations, we anticipate that WS2/BN supercells could induce Brillouin-zone-folded phonons that contribute to the interlayer coupling, leading to a complex nature of broad Raman peaks. We further demonstrate the significance of a previously unexplored parameter, the interlayer spacing. By varying the temperature and high pressure, we effectively manipulated the strengths of EPC with on/off capabilities, indicating critical thresholds of the layer-layer spacing for activating and strengthening interlayer EPC. Our findings provide new opportunities to engineer vdW heterostructures with controlled interlayer coupling.

2.
Fish Physiol Biochem ; 48(4): 1011-1023, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35804212

RESUMEN

This study presents the first incidence of intersex associated with testis-ova in spotted scat (Scatophagus argus) reared in a controlled environment. The testis-ova is associated with the abnormal occurrence of primary oocytes (POs) in some male testis and is referred to as ectopic primary oocytes (Ecto-PO), whiles individuals with Ecto-PO are called "Ecto-PO gonad/individuals." We investigated gonads of 129 male spotted scat aged 4-12 and 18 months after hatch (mah) by histological studies for the presence of female sexual characteristics. A total of 20 out of 88 gonads representing 22.7% of male fish aged 6-12, or 15.5% of all male fish sampled, were found to have visible Ecto-PO. At least, the Ecto-PO had an average of 7 oocytes per gonadal section, indicating high severity. The Ecto-PO appears after sex differentiation and degenerates during sexual maturation. The Ecto-PO did not significantly influence the expression pattern of male and female sex-related genes performed using qPCR. Immunofluorescence of 42sp50 specifically stained the Ecto-PO without influence from the surrounding testicular tissues. In addition, temperature did not correlate with the proliferation of the Ecto-PO, but rather gonad developmental strategy. The results show that the naturally occurring Ecto-PO might not be detrimental to testis development and could be considered a frequent-high-level incidence of natural aberration. This study highlights the intricacy of fish sex differentiation and provides a new research chapter to ascertain the mystery behind the occurrence of Ecto-PO.


Asunto(s)
Trastornos del Desarrollo Sexual , Peces , Animales , Trastornos del Desarrollo Sexual/genética , Trastornos del Desarrollo Sexual/veterinaria , Femenino , Peces/genética , Gónadas , Masculino , Diferenciación Sexual , Testículo
3.
Sensors (Basel) ; 21(7)2021 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-33916361

RESUMEN

The direct-sequence spread-spectrum (DSSS) technique has been widely used in wireless secure communications. In this technique, the baseband signal is spread over a wider bandwidth using pseudo-random sequences to avoid interference or interception. In this paper, the authors propose methods to adaptively detect the DSSS signals based on knowledge-enhanced compressive measurements and artificial neural networks. Compared with the conventional non-compressive detection system, the compressive detection framework can achieve a reasonable balance between detection performance and sampling hardware cost. In contrast to the existing compressive sampling techniques, the proposed methods are shown to enable adaptive measurement kernel design with high efficiency. Through the theoretical analysis and the simulation results, the proposed adaptive compressive detection methods are also demonstrated to provide significantly enhanced detection performance efficiently, compared to their counterpart with the conventional random measurement kernels.

4.
Ergonomics ; 58(4): 635-49, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25909756

RESUMEN

Theoretical and practical approaches to safety based on sociotechnical systems principles place heavy emphasis on the intersections between social-organisational and technical-work process factors. Within this perspective, work system design emphasises factors such as the joint optimisation of social and technical processes, a focus on reliable human-system performance and safety metrics as design and analysis criteria, the maintenance of a realistic and consistent set of safety objectives and policies, and regular access to the expertise and input of workers. We discuss three current approaches to the analysis and design of complex sociotechnical systems: human-systems integration, macroergonomics and safety climate. Each approach emphasises key sociotechnical systems themes, and each prescribes a more holistic perspective on work systems than do traditional theories and methods. We contrast these perspectives with historical precedents such as system safety and traditional human factors and ergonomics, and describe potential future directions for their application in research and practice. PRACTITIONER SUMMARY: The identification of factors that can reliably distinguish between safe and unsafe work systems is an important concern for ergonomists and other safety professionals. This paper presents a variety of sociotechnical systems perspectives on intersections between social--organisational and technology--work process factors as they impact work system analysis, design and operation.


Asunto(s)
Salud Laboral , Seguridad , Análisis de Sistemas , Ergonomía , Humanos , Modelos Organizacionales , Cultura Organizacional , Lugar de Trabajo
5.
Biomedicine (Taipei) ; 12(3): 56-71, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36381194

RESUMEN

COVID-19 pandemic has been a global outbreak of coronavirus (SARS-CoV-2 virus) since 2019. Taiwan Chingguan Yihau (NRICM101) is the first traditional Chinese medicine (TCM) classic herbal formula and is widely used for COVID-19 patients in Taiwan and more than 50 nations. This study is to investigate in silico target fishing for the components of NRICM101 and to explore whether NRICM101 inhibits cytokines-induced normal human lung cell injury in vitro. Our results showed that network prediction of NRICM101 by a high throughput target screening platform showed that NRICM101 has multiple functions that may affect cytokine regulation to prevent human lung cell injury. In addition, NRICM101 revealed protective effects against TNF-α/IL-1ß-induced normal human lung HEL 299 cell injury through JNK and p38MAPK kinase signaling. Next-generation sequencing (NGS) analysis of NRICM101 on TNF-α/IL-1ß-injured HEL 299 cells indicated that inflammatory pathway, cell movement of macrophages, cellular infiltration by macrophages, and Th1/Th2 immuno-regulation pathways were included. Thus, NRICM101 is a therapeutic agent, and it can improve COVID-19 syndrome to confer beneficial effects through multiple targeting and multiple mechanisms.

6.
Mol Med Rep ; 20(1): 117-124, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31115565

RESUMEN

The adenosine A2a receptor agonist CGS21680 has been suggested to act as an anti­inflammatory agent that protects against cardiopulmonary bypass (CPB)­induced organ injury. However, the therapeutic effects of CGS21680 for CPB­induced lung injury have not been comprehensively evaluated. Using a juvenile rat model, the present study was designed to evaluated whether CGS21680 attenuates CPB­induced lung injury. Our juvenile rat CPB model was established by 60 min CPB with or without CGS21680 pretreatment (100 µg/kg, in the CPB priming solution). Rats in the Sham group only underwent cannulation and heparinization. Serum and pulmonary levels of inflammatory markers and histological features of pulmonary tissues were analyzed. All juvenile rats survived following CPB. Significantly elevated serum levels of tumor necrosis factor­α (TNF­α), myeloperoxidase (MPO) and interleukin­1ß (IL­1ß), and decreased glutathione peroxidase (GSH­PX) levels were observed in the CPB group compared to the Sham group (all P<0.05). TNF­α, MPO and IL­1ß were significantly decreased, while GSH­PX was markedly increased in the CGS group when compared to the CPB group. Consistently, pulmonary tissues from rats in the CPB group showed considerable amounts of damaged pneumocytes, severe edema, and increased alveolar macrophages, and significantly higher lung injury scores compared to the controls. Collectively, these changes were all further attenuated by CGS21680. Pretreatment with CGS21680 before CPB attenuated pulmonary injury, which may be related to the anti­inflammatory effects of CGS21680 downstream of A2a receptor activation.


Asunto(s)
Agonistas del Receptor de Adenosina A2/farmacología , Adenosina/análogos & derivados , Inflamación/tratamiento farmacológico , Lesión Pulmonar/tratamiento farmacológico , Fenetilaminas/farmacología , Adenosina/farmacología , Animales , Puente Cardiopulmonar/efectos adversos , Modelos Animales de Enfermedad , Humanos , Inflamación/genética , Inflamación/patología , Interleucina-1beta/genética , Pulmón/metabolismo , Pulmón/patología , Lesión Pulmonar/genética , Lesión Pulmonar/fisiopatología , Peroxidasa/genética , Ratas , Ratas Sprague-Dawley , Receptor de Adenosina A2A/genética , Factor de Necrosis Tumoral alfa/genética
7.
Oncol Rep ; 38(2): 959-966, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28656255

RESUMEN

Accumulating evidence demonstrates that dysregulated microRNAs (miRNAs) play a critical role in tumorigenesis and progression of various cancers. miR-320b, a member of miR­320 family, was revealed downregulated in numerous human cancers, including nasopharyngeal carcinoma and colorectal cancer. However, the function of miR­320b in human glioma remained poorly defined. In this study, we report that miR­320b was lowly expressed in glioma tissues and cell lines in contrast with controls, being closely correlated with histological malignancy of glioma. Furthermore, patients with low expression of miR­320b were associated with poor prognostic outcomes. In vitro functional assays indicated that overexpression of miR­320b could markedly enhance cell apoptosis rate and suppress cell proliferation, migration and invasion. miR-320b mimic impaired cell cycle and metastasis through inhibiting the expression of G1/S transition key regulator Cyclin D1 as well as decreasing the expression level of MMP2 and MMP9. Additionally, upregulation of miR­320b could markedly promote apoptosis by increasing the level of Bax and reducing Bcl-2 expression in glioma. Taken together, our data suggested that miR­320b might serve as a novel prognostic marker and potential therapeutic target for glioma.


Asunto(s)
Biomarcadores de Tumor/genética , Glioma/genética , MicroARNs/genética , Pronóstico , Adulto , Anciano , Apoptosis/genética , Carcinogénesis/genética , Movimiento Celular/genética , Proliferación Celular/genética , Ciclina D1/genética , Femenino , Regulación Neoplásica de la Expresión Génica , Glioma/patología , Humanos , Masculino , Metaloproteinasa 2 de la Matriz/genética , Metaloproteinasa 9 de la Matriz/genética , Persona de Mediana Edad , Proteínas Proto-Oncogénicas c-bcl-2/genética , Proteína X Asociada a bcl-2/genética
8.
Biochem Biophys Res Commun ; 302(4): 703-9, 2003 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-12646226

RESUMEN

Since Chinese hamster ovary (CHO) cells never express urate oxidase (UO), we tried to establish cell lines stably producing UO in order to elucidate the peroxisomal import process. The enzyme is a peroxisome targeting signal 1 (PTS1) protein harboring SKL motif at the carboxy-terminus [Biochem. Biophys. Res. Commun. 158 (1989) 991] and PEX5 protein (Pex5p) is supposed to be involved in the import process [Nat. Genet. 9 (1995) 115; J. Cell Biol. 130 (1995) 51]. We transfected a cDNA encoding rat UO into both wild type and PEX5-defective CHO cells to isolate each cell line stably producing the enzyme. While we examined the import process of UO in mutant cells, we noticed an interesting observation by using polyclonal antibody U1 or U2, which separately recognizes epitopes of UO. U1 antibody mainly interacts with epitopes in the amino-terminal region of UO. On the other hand, U2 antibody reacts with many epitopes distributed in the broad region of UO molecule. When UO produced in cultured cells was stained with U2 antibody, the enzyme was detected in peroxisomes of both wild type and PEX5-mutant cells. Whereas, U1 antibody stained the peroxisomal UO in wild type cells, but not in PEX5-mutant cells. These immunocytochemical observations suggest that the epitopes at the amino-terminal region of UO will be concealed in mutant cells. When the mutant cells were transfected with wild type PEX5 cDNA, U1 antibody came to react with UO in peroxisomes of mutant cells. The restoration indicates that the exposure of N-terminal epitopes of UO will depend upon the functional Pex5p. Immunoelectron microscopic observation showed that the peroxisomal import of UO was partially retarded in PEX5 mutant cells. The observation also supported the fact that UO was mainly localized in the peroxisomal matrix of wild type cells but in the membrane of mutant cells.


Asunto(s)
Epítopos , Peroxisomas/metabolismo , Receptores Citoplasmáticos y Nucleares/genética , Urato Oxidasa/inmunología , Urato Oxidasa/metabolismo , Animales , Anticuerpos/metabolismo , Células CHO , Línea Celular , Cricetinae , Microscopía Electrónica , Receptor de la Señal 1 de Direccionamiento al Peroxisoma , Ratas , Receptores Citoplasmáticos y Nucleares/metabolismo , Urato Oxidasa/genética
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA