National Cheng Kung University

About: National Cheng Kung University is a education organization based out in Tainan City, Taiwan. It is known for research contribution in the topics: Population & Thin film. The organization has 49723 authors who have published 69799 publications receiving 1437420 citations. The organization is also known as: NCKU.

Running exercise protects the substantia nigra dopaminergic neurons against inflammation-induced degeneration via the activation of BDNF signaling pathway

Abstract: Parkinson's disease (PD) is characterized by a progressive and selective loss of dopaminergic (DA) neurons in the substantia nigra (SN). Although the etiology of PD remains unclear, neuroinflammation has been implicated in the development of PD. Running exercise (Ex) promotes neuronal survival and facilitates the recovery of brain functions after injury. Therefore, we hypothesize that Ex protects the DA neurons against inflammation-induced injury in the SN. An intraperitoneal lipopolysaccharide (LPS, 1 mg/kg) injection induced microglia activation in the SN within hours, followed by a reduction in the number of DA neurons. LPS reduced the level of dopamine in the striatum and impaired the performance of motor coordination. Furthermore, the levels of the brain-derived neurotrophic factor (BDNF) were reduced in the SN by the LPS treatment. Four weeks of Ex before LPS treatment completely prevented the LPS-induced loss of DA neurons, reduction of dopamine levels and dysfunction of motor movement. Ex did not change the LPS-induced status of microglia activation or the levels of cytokines/chemokines, but restored the levels of LPS-reduced BDNF-TrkB signaling molecules. Blocking the action of BDNF, through its receptor TrkB antagonist, abolished the Ex-induced protection against LPS-induced DA neuron loss. Intrastriatal perfusion of BDNF alone was sufficient to counteract the LPS-induced DA neuron loss. Altogether, our results show that Ex protects DA neurons against inflammation-induced insults. The neuroprotective effects of Ex are not due to the modulation of inflammation status, but rather to the activation of the BDNF-TrkB signaling pathway.

Work-related COVID-19 transmission in six Asian countries/areas: A follow-up study.

Abstract: Objective There is limited evidence of work-related transmission in the emerging coronaviral pandemic. We aimed to identify high-risk occupations for early coronavirus disease 2019 (COVID-19) local transmission. Methods In this observational study, we extracted confirmed COVID-19 cases from governmental investigation reports in Hong Kong, Japan, Singapore, Taiwan, Thailand, and Vietnam. We followed each country/area for 40 days after its first locally transmitted case, and excluded all imported cases. We defined a possible work-related case as a worker with evidence of close contact with another confirmed case due to work, or an unknown contact history but likely to be infected in the working environment (e.g. an airport taxi driver). We calculated the case number for each occupation, and illustrated the temporal distribution of all possible work-related cases and healthcare worker (HCW) cases. The temporal distribution was further defined as early outbreak (the earliest 10 days of the following period) and late outbreak (11th to 40th days of the following period). Results We identified 103 possible work-related cases (14.9%) among a total of 690 local transmissions. The five occupation groups with the most cases were healthcare workers (HCWs) (22%), drivers and transport workers (18%), services and sales workers (18%), cleaning and domestic workers (9%) and public safety workers (7%). Possible work-related transmission played a substantial role in early outbreak (47.7% of early cases). Occupations at risk varied from early outbreak (predominantly services and sales workers, drivers, construction laborers, and religious professionals) to late outbreak (predominantly HCWs, drivers, cleaning and domestic workers, police officers, and religious professionals). Conclusions Work-related transmission is considerable in early COVID-19 outbreaks, and the elevated risk of infection was not limited to HCW. Implementing preventive/surveillance strategies for high-risk working populations is warranted.

Nuclear epidermal growth factor receptor (EGFR) interacts with signal transducer and activator of transcription 5 (STAT5) in activating Aurora-A gene expression

Abstract: Loss of the maintenance of genetic material is a critical step leading to tumorigenesis. It was reported that overexpression of Aurora-A and the constitutive activation of the epidermal growth factor (EGF) receptor (EGFR) are implicated in chromosome instability. In this study, we examined that when cells treated with EGF result in centrosome amplification and microtubule disorder, which are critical for genetic instability. Interestingly, the expression of Aurora-A was also increased by EGF stimulus. An immunofluorescence assay indicated that EGF can induce the nuclear translocation of EGFR. Chromatin immunoprecipitation (ChIP) and re-ChIP assays showed significant EGF-induced recruitment of nuclear EGFR and signal transducer and activator of transcription 5 (STAT5) to the Aurora-A promoter. A co-immunoprecipitation assay further demonstrated that EGF induces nuclear interaction between EGFR and STAT5. A small interfering (si)RNA knockdown assay also showed that EGFR and STAT5 are indeed involved in EGF-increased Aurora-A gene expression. Altogether, this study proposes that the nuclear EGFR associates with STAT5 to bind and increase Aurora-A gene expression, which ultimately may lead to chromosome instability and tumorigenesis. The results also provide a novel linkage between the EGFR signaling pathway and overexpression of Aurora-A in tumorigenesis and chromosome instability.

Indentation Resilience of Conventional and Auxetic Foams

Abstract: Materials with a negative Poisson's ratio (auxetic materials) demonstrate the fascinating property of becoming fatter when stretched. This phenomenon is fundamentally important to the properties of a material and a significant change in the value of the ratio has significant effects on the material's mechanical performance. This article describes foams with a negative Poisson's ratio that show better indentation resilience than conventional foams with a positive Poisson's ratio. The unusual mechanical properties of auxetic foams are attributed to the deformation characteristics of re-entrant (concave polyhedral) cell structures.