As the basic sector providing basic service and promoting economy development, the increment demand of transport sector has brought much more pressure on the environment. Beijing-Tianjin-Hebei region ...is the representative region of the advanced region of China and it is significant to analyze how to achieve the low-carbon transport development in Beijing-Tianjin-Hebei region, meanwhile provide reference of green development for other regions. Using the panel data from 1995 to 2016, the paper analyses the driving factor of carbon dioxide emissions from transport sector with two different analytical methods. The results of LMDI show that transportation energy intensity and economic effect is the main factor increasing the carbon dioxide emissions and the contributing factors to the carbon dioxide emissions reduction in the transport sector are the energy structure effect, the freight turnover of unit industrial output effect and the industrialization effect. In different subclasses divided by different threshold variables, industrialization has the positive impact while the coefficients vary, which indicates that appropriate development policies should be formulated in light of the development characteristics of different regions.
This study aims at advancing leadership research in corporate communications by introducing a more rigorous statistical approach to test whether communication professionals of different hierarchical ...reporting levels, years of experience, and educational backgrounds would ascribe the same meanings to the construct of leadership excellence in corporate communications via survey research. By using an established measurement model of leadership excellence in corporate communications, the study uses three samples, including senior communication executives/leaders, mid-level communication professionals, and senior college students majoring in communication and/or public relations, to conduct the measurement invariance tests. By imposing constraints to different parameters in a sequence of nested models, findings indicate that the measures of leadership excellence in corporate communications can be equivalent across multiple groups. Measurement invariance was confirmed at multiple levels, including the higher-order measurement model, configural invariance, metric invariance, scalar invariance, and error invariance. This study deepens our understanding of measurement invariance when applying multi-group comparison in testing leadership excellence. Such evidence can also be used as central principles when developing corresponding leadership training and development modules by organizations in supporting multicultural and multi-group sensitivity in leadership development. Future research and practical implications are also discussed.
Exogenous H2S donor, sodium hydrosulfide (NaHS), can influence the bleomycin‐induced pulmonary fibrosis by attenuating the epithelial‐mesenchymal transition (EMT) of alveolar epithelial cells, but ...whether NaHS affects paraquat (PQ)‐induced EMT and the molecular mechanisms remain unclarified. The aim of the present study is to examine the effect of exogenous NaHS on PQ‐induced EMT in human alveolar epithelial cells (A549 cells) and assess if this effect occurs through regulating transforming growth factor (TGF)‐β1/Smad2/3 signaling pathway. The expressions of endogenous H2S producing enzymes, namely cystathionine β‐synthase, cystathionine γ‐lyase and 3‐mercaptopyruvate sulfur transferase, were detected by reverse transcription‐polymerase chain reaction and western blotting. The induced EMT was assessed by morphological and phenotypic characterizations, and the protein level of E‐cadherin and vimentin were detected by western blotting. To investigate the effect of NaHS on PQ‐induced EMT and potential mechanism, A549 cells were pretreated with NaHS before incubating with PQ and then evaluated by morphological changes, cell migration ability, the expression of EMT markers and TGF‐β1/Smad2/3 signaling pathway related proteins. PQ significantly downregulated the expression levels of cystathionine β‐synthase and cystathionine γ‐lyase, but not 3‐mercaptopyruvate sulfur transferase, in a time‐dependent manner in A549 cells. Exogenous NaHS could significantly retard PQ‐induced morphological changes and cell migration ability. Furthermore, exogenous NaHS significantly upregulated the expression of E‐cadherin, whereas it downregulated the expression of vimentin. In addition, exogenous NaHS could also significantly attenuates PQ‐induced TGF‐β1, phosphorylated Smad2/3 proteins expression, which induced by PQ in a time‐dependent manner. This study provides the first evidence that exogenous NaHS attenuates PQ‐induced EMT and migration of human alveolar epithelial cells through regulating the TGF‐β1/Smad2/3 signaling pathway.
Exogenous H2S donor, sodium hydrosulfide (NaHS), can influence the bleomycin induced pulmonary fibrosis by attenuating the epithelial‐mesenchymal transition (EMT) of alveolar epithelial cells, but whether NaHS affects paraquat (PQ)‐induced EMT and the molecular mechanisms remain unclarified. The aim of the present study is to examine the effect of exogenous NaHS on PQ‐induced EMT in human alveolar epithelial cells (A549 cells) and assess if this effect occurs through regulating transforming growth factor (TGF)‐β1/Smad2/3 signaling pathway.
The optical control of polarization switching is attracting tremendous interest because photoirradiation stands out as a nondestructive, noncontact, and remote-control means beyond an electric or ...strain field. The current research mainly uses various photoexcited electronic effects to achieve the photocontrol polarization, such as a light-driven flexoelectric effect and a photovoltaic effect. However, since photochromism was discovered in 1867, the structural phase transition caused by photoisomerization has never been associated with ferroelectricity. Here, we successfully synthesized an organic photochromic ferroelectric with polar space group Pna21, 3,4,5-trifluoro-N-(3,5-di-tert-butylsalicylidene)aniline, whose color can change between yellow and orange via laser illumination. Its dielectric permittivity and spontaneous polarization can be switched reversibly with a photoinduced phase transition triggered by structural photoisomerization between the enol form and the trans-keto form. To our knowledge, this is the first photoswitchable ferroelectric crystal to achieve polarization switching through a structural phase transition triggered by photoisomerization. This finding paves the way toward photocontrol of smart materials and biomechanical applications in the future.
Plastic ferroelectrics, featuring large entropy changes in phase transitions, hold great potential application for solid-state refrigeration due to the electrocaloric effect. Although conventional ...ceramic ferroelectrics (
e.g.
, BaTiO
3
and KNbO
3
) have been widely investigated in the fields of electrocaloric material and catalysis, organic plastic ferroelectrics with a high Curie point (
T
c
) are rarely reported but are of great importance for the sake of environmental protection. Here, we reported an organic plastic ferroelectric, (−)-camphanic acid, which crystallizes in the
P
2
1
space group, chiral polar 2 (C
2
) point group, at room temperature. It undergoes plastic paraelectric-to-ferroelectric phase transition with the Aizu notation of 23F2 and high
T
c
of 414 K, showing large entropy gain (Δ
S
t
= 48.2 J K
−1
mol
−1
). More importantly, the rectangular polarization-electric field (
P
-
E
) hysteresis loop was recorded on the thin film samples with a large saturated polarization (
P
s
) of 5.2 μC cm
−2
. The plastic phase transition is responsible for its multiaxial ferroelectric feature. This work highlights the discovery of organic multiaxial ferroelectrics driven by the motive of combining chirality and plastic phase transition, which will extensively promote the practical application of such unique functional materials.
An organic plastic ferroelectric, (−)-Camphanic acid, shows multiaxial ferroelectric feature and large entropy gain during the phase transition.
Ophiorrhiza japonica Bl. is a traditional Chinese materia medica widely used to treat several diseases. Chemical and pharmacological studies on O. japonica have been carried out; however, neither of ...them has been fully explored. In this study, an array of compounds was isolated from the title plant, including a new anthraquinone, ophiorrhizaquinone A (1), three alkaloids 2–4 and seven other compounds 5–11 with diverse structural types. Additionally, compounds 2, 5, 7, 8, 10 and 11 were isolated from the genus of Ophiorrhiza for the first time. Antioxidant bioassays in vitro using DPPH and ABTS were performed, and the results showed that compound 3 exhibited modest antioxidant activity with IC50 values of 0.0321 mg/mL and 0.0319 mg/mL, respectively. An in silico study of PPARα agonistic activities of compounds 2 and 3 was conducted by molecular docking experiments, revealing that both of them occupied the active site of PPARα via hydrogen bonds and hydrophobic interactions effectively. This study enriched both the phytochemical and pharmacological profiles of O. japonica.
The dysfunction of the renin-angiotensin system (RAS) has been observed in coronavirus infection disease (COVID-19) patients, but whether RAS inhibitors, such as angiotensin-converting enzyme ...inhibitors (ACEIs) and angiotensin II type 1 receptor blockers (ARBs), are associated with clinical outcomes remains unknown. COVID-19 patients with hypertension were enrolled to evaluate the effect of RAS inhibitors. We observed that patients receiving ACEI or ARB therapy had a lower rate of severe diseases and a trend toward a lower level of IL-6 in peripheral blood. In addition, ACEI or ARB therapy increased CD3 and CD8 T cell counts in peripheral blood and decreased the peak viral load compared to other antihypertensive drugs. This evidence supports the benefit of using ACEIs or ARBs to potentially contribute to the improvement of clinical outcomes of COVID-19 patients with hypertension.
A portable kit was demonstrated for rapid and reliable surface-enhanced Raman scattering (SERS) detection of drugs in human urine. This kit contains two sealed reagent tubes, a packet of standardized ...SERS substrates, and a mini Raman device. A 3 min pretreatment for separating amphetamines from human urine was developed with an extraction rate of >80% examined by ultraperformance liquid chromatography (UPLC). Simultaneously, highly reproducible two-dimensional (2D) gold nanorod (GNR) arrays were assembled by the use of methoxymercaptopoly(ethylene glycol) (mPEG-SH) capping. Thirty batches of GNR arrays produced the 1001 cm–1 intensity of methamphetamine (MA) molecules with a relative standard deviation (RSD) of 7.9%, and a 21 × 21 μm2 area mapping on a 2D GNR array produced a statistical RSD of <10%, implying an excellent reproducibility and uniformity. The detection limit of amphetamines in human urine was at least 0.1 ppm. Moreover, the portable kit was successfully used for detecting MA, 3,4-methylenedioxymethamphetamine (MDMA), and methcathinone (MC) in 30 volunteers’ urine samples with various clinical natures, and the dual-analyte detection of MA and MDMA implied a good capability of multiplex analysis. UPLC examination and the SERS recovery test clearly indicated that our pretreatment procedure was sufficient to lower the high background signals caused by complex components in urine and demonstrated the practicability and the resistance to false positives, which is a vital problem for law enforcement applications. The excellent performance of our portable kit promises a great prospective toward a rapid, reliable, and on-spot analyzer, especially for public safety and healthcare.
PDF
