207 research outputs found
Relationships Between External Factors and University Students' Attitudes towards Academic Research
Research is an important part of an academic career, yet it is not always frequently practiced by most students. This descriptive-correlational research aimed to find out the external factors that influence students’ attitudes toward research. We sampled 201 undergraduates at Wenzhou-Kean University and analyzed their responses to the questionnaire in order to determine the relationship between possible factors and their attitudes. The results revealed that the external factor of the training environment has a moderate positive influence on research attitude, while support from the university has a strong positive influence on research attitude. Specifically, factors of faculty support, curriculum design, on-campus academic activities, library service, and financial support all moderately influence students’ attitudes towards research in a positive way. The most salient influential factor of all is faculty support. The results suggested that to improve students’ attitudes towards research, sufficient support is vital, especially academic and financial support. Therefore, to externally encourage students to conduct academic research, faculty and university could give more consideration to support provision.Echiverri, LL.; Yang, J.; Tang, F. (2020). Relationships Between External Factors and University Students' Attitudes towards Academic Research. En 6th International Conference on Higher Education Advances (HEAd'20). Editorial Universitat Politècnica de València. (30-05-2020):669-677. https://doi.org/10.4995/HEAd20.2020.11123OCS66967730-05-202
Origin and tuning of the magnetocaloric effect for the magnetic refrigerant MnFe(P1-xGex)
Neutron diffraction and magnetization measurements of the magneto refrigerant
Mn1+yFe1-yP1-xGex reveal that the ferromagnetic and paramagnetic phases
correspond to two very distinct crystal structures, with the magnetic entropy
change as a function of magnetic field or temperature being directly controlled
by the phase fraction of this first-order transition. By tuning the physical
properties of this system we have achieved a maximum magnetic entropy change
exceeding 74 J/Kg K for both increasing and decreasing field, more than twice
the value of the previous record.Comment: 6 Figures. One tabl
Chinese ‘low-tar’ cigarettes do not deliver lower levels of nicotine and carcinogens
BackgroundLow-tar cigarette smoking is gaining popularity in China. The China National Tobacco Corporation (CNTC) promotes low-tar cigarettes as safer than regular cigarettes.MethodsA total of 543 male smokers smoking cigarettes with different tar yields (15 mg, regular cigarettes, 10-13 mg low-tar cigarettes and < 10 mg low-tar cigarettes) were recruited in Shanghai, China, who then completed a questionnaire on smoking behaviour and provided a urine sample for analysis of the nicotine metabolites cotinine and trans-3'-hydroxycotinine. A total of 177 urine samples were selected at random for the analysis of the carcinogens polycyclic aromatic hydrocarbon metabolites (PAHs) (1-hydroxypyrene, naphthols, hydroxyfluorenes and hydroxyphenanthrenes) and the tobacco specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-butanone (NNK) metabolites, 4-(methylnitrosamino)-1-(3-pyridyl)-butanol (NNAL) and NNAL-glucuronide. Values were normalised by creatinine to correct for possible distortions introduced by dilution or concentration of the urine.ResultsSmokers of low-tar cigarettes smoked fewer cigarettes per day (p=0.001) compared to smokers of regular cigarettes. Despite this lower reported consumption, levels of cotinine, trans-3'-hydroxycotinine and PAHs in urine of people smoking low-tar cigarettes were not correlated with nominal tar delivery of the cigarettes they smoked. Urine concentrations of NNAL were higher in smokers of lower tar than higher tar cigarettes.ConclusionsChinese low-tar cigarettes do not deliver lower doses of nicotine and carcinogens than regular cigarettes, therefore it is unlikely that there would be any reduction in harm. CNTC's promotion of low-tar cigarettes as 'less harmful' is a violation of the World Health Organization Framework Convention on Tobacco Control, which China ratified in 2005
N-Acetyl-Serotonin Protects HepG2 Cells from Oxidative Stress Injury Induced by Hydrogen Peroxide
Oxidative stress plays an important role in the pathogenesis of liver diseases. N-Acetyl-serotonin (NAS) has been reported to protect against oxidative damage, though the mechanisms by which NAS protects hepatocytes from oxidative stress remain unknown. To determine whether pretreatment with NAS could reduce hydrogen peroxide- (H2O2-) induced oxidative stress in HepG2 cells by inhibiting the mitochondrial apoptosis pathway, we investigated the H2O2-induced oxidative damage to HepG2 cells with or without NAS using MTT, Hoechst 33342, rhodamine 123, Terminal dUTP Nick End Labeling Assay (TUNEL), dihydrodichlorofluorescein (H2DCF), Annexin V and propidium iodide (PI) double staining, immunocytochemistry, and western blot. H2O2 produced dramatic injuries in HepG2 cells, represented by classical morphological changes of apoptosis, increased levels of malondialdehyde (MDA) and intracellular reactive oxygen species (ROS), decreased activity of superoxide dismutase (SOD), and increased activities of caspase-9 and caspase-3, release of cytochrome c (Cyt-C) and apoptosis-inducing factor (AIF) from mitochondria, and loss of membrane potential (ΔΨm). NAS significantly inhibited H2O2-induced changes, indicating that it protected against H2O2-induced oxidative damage by reducing MDA levels and increasing SOD activity and that it protected the HepG2 cells from apoptosis through regulating the mitochondrial apoptosis pathway, involving inhibition of mitochondrial hyperpolarization, release of mitochondrial apoptogenic factors, and caspase activity
Tweaking the spin-wave dispersion and suppressing the incommensurate phase in LiNiPO4 by iron substitution
Elastic and inelastic neutron scattering studies of
Li(NiFe)PO single crystals reveal anomalous spin-wave
dispersions along the crystallographic direction parallel to the characteristic
wave vector of the magnetic incommensurate phase. The anomalous spin-wave
dispersion ({\it magnetic soft mode}) indicates the instability of the
Ising-like ground state that eventually evolves into the incommensurate phase
as the temperature is raised. The pure LiNiPO system (), undergoes a
first-order magnetic phase transition from a long-range incommensurate phase to
an antiferromagnetic ground state at {\it T} = 20.8 K. At 20% Fe
concentrations, although the AFM ground state is to a large extent preserved as
that of the pure system, the phase transition is second-order, and the
incommensurate phase is completely suppressed. Analysis of the dispersion
curves using a Heisenberg spin Hamiltonian that includes inter- and in-plane
nearest and next-nearest neighbor couplings reveals frustration due to strong
competing interactions between nearest- and a next-nearest neighbor site,
consistent with the observed incommensurate structure. The Fe substitution only
slightly lowers the extent of the frustration, sufficient to suppress the IC
phase. An energy gap in the dispersion curves gradually decreases with the
increase of Fe content from 2 meV for the pure system () to
0.9 meV for
Propolis Reduces Phosphatidylcholine-Specific Phospholipase C Activity and Increases Annexin a7 Level in Oxidized-LDL-Stimulated Human Umbilical Vein Endothelial Cells
To understand the mechanisms underlying the regulating dyslipidemia action of Chinese propolis and Brazilian green propolis, we investigated their effects on phosphatidylcholine-specific phospholipase C (PC-PLC) activity and annexin a7 (ANXA7) level which play crucial roles in the control of the progress of atherosclerosis. Furthermore, active oxygen species (ROS) levels, nuclear factor-KappaB p65 (NF-κB p65), and mitochondrial membrane potential (MMP) were also investigated in oxidized-LDL- (ox-LDL-) stimulated human umbilical vein endothelial cells (HUVECs). Our data indicated that the treatment of both types of propolis 12.5 μg/mL significantly increased cell viability and attenuated apoptosis rate, increased ANXA7 level, and decreased PC-PLC activity. Both types of propolis also inhibited ROS generation as well as the subsequent MMP collapse, and NF-κB p65 activation induced by ox-LDL in HUVECs. Our results also indicated that Chinese propolis and Brazilian green propolis had similar biological activities and prevented ox-LDL induced cellular dysfunction in HUVECs
A genome-wide detection of copy number variations using SNP genotyping arrays in swine
Altered intrinsic functional brain architecture in patients with functional constipation: a surface-based network study
BackgroundFunctional constipation (FCon) is a common functional gastrointestinal disorder (FGID). Studies have indicated a higher likelihood of psychiatric disorders, such as anxiety, depression, sleep disturbances, and impaired concentration, among patients with FCon. However, the underlying pathophysiological mechanisms responsible for these symptoms in FCon patients remain to be fully elucidated. The human brain is a complex network architecture with several fundamental organizational properties. Neurological interactions between gut symptoms and psychiatric issues may be closely associated with these complex networks.MethodsIn the present study, a total of 35 patients with FCon and 40 healthy controls (HC) were recruited for a series of clinical examinations and resting-state functional magnetic imaging (RS-fMRI). We employed the surface-based analysis (SBA) approach, utilizing the Schaefer cortical parcellation template and Tikhonov regularization. Graph theoretical analysis (GTA) and functional connectivity (FC) analysis of RS-fMRI were conducted to investigate the aberrant network alterations between the two groups. Additionally, correlation analyses were performed between the network indices and clinical variables in patients with FCon.ResultsAt the global level, we found altered topological properties and networks in patients with FCon, mainly including the significantly increased clustering coefficient (CP), local efficiency (Eloc), and shortest path length (LP), whereas the decreased global efficiency (Eglob) compared to HC. At the regional level, patients with FCon exhibited increased nodal efficiency in the frontoparietal network (FPN). Furthermore, FC analysis demonstrated several functional alterations within and between the Yeo 7 networks, particularly including visual network (VN), limbic network (LN), default mode network (DMN), and somatosensory-motor network (SMN) in sub-network and large-scale network analysis. Correlation analysis revealed that there were no significant associations between the network metrics and clinical variables in the present study.ConclusionThese results highlight the altered topological architecture of functional brain networks associated with visual perception abilities, emotion regulation, sensorimotor processing, and attentional control, which may contribute to effectively targeted treatment modalities for patients with FCon
Antiferromagnetism in the magnetoelectric effect single crystal LiMnPO
Elastic and inelastic neutron scattering studies reveal details of the
antiferromagnetic tansition and intriguing spin-dynamics in the
magneto-electric effect single crystal LiMnPO. The elastic scattering
studies confirm the system is antiferromagnetic (AFM) below =33.75 K with
local magnetic moments (Mn; ) that are aligned along the
crystallographic a-axis. The spin-wave dispersion curves propagating along the
three principal axes, determined by inelastic scattering, are adequately
modeled in the linear spin-wave framework assuming a spin-Hamiltonian that is
parameterized by inter- and in-plane nearest- and next-nearest-neighbor
interactions, and by easy-plane anisotropy. The temperature dependence of the
spin dynamics makes this an excellent model many-body spin system to address
the question of the relationship between spin-wave excitations and the order
parameter
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