Shallow Crustal Structure of S-Wave Velocities in the Coastal Area of South China Constrained by Receiver Function Amplitudes

As a traditional method, passive seismic exploration is used to construct the body-wave velocity structure of the upper crust, but it is cost-ineffective and depth-limited when applied to large areas. In this study, we use another more economical method to determine the S-wave velocity (SWV) of the upper crust based on the principle that the amplitude of the direct P-wave on the teleseismic receiver function is sensitive to the upper crust. Using the amplitudes of the massive receiver functions from permanent broadband seismic stations, the SWV structure of the upper crust is obtained in the coastal area of South China (CASC). A pattern of high to low SWVs is exhibited across the study area, with SWVs varying about 2.5–3.7 km/s from west to east. In the profile parallel to the coastline, lateral variations in the SWV correspond to the fault zone, indicating that the cutting depth of most coastal faults is approximately 10 km. Referring to previous studies, we deduce that the low SWV in most sub-areas can be interpreted as the joint effect of the sedimentary layer of the alluvial plain and the accumulation of underground heat flows, in addition to multistage fracturing tectonism. Moreover, the gradual change in the SWV in each profile from the surface to approximately 10 km is correlated with multiple invasions and the coverage of volcanic rocks, to a certain extent

Shallow Crustal Structure of S-Wave Velocities in the Coastal Area of South China Constrained by Receiver Function Amplitudes

As a traditional method, passive seismic exploration is used to construct the body-wave velocity structure of the upper crust, but it is cost-ineffective and depth-limited when applied to large areas. In this study, we use another more economical method to determine the S-wave velocity (SWV) of the upper crust based on the principle that the amplitude of the direct P-wave on the teleseismic receiver function is sensitive to the upper crust. Using the amplitudes of the massive receiver functions from permanent broadband seismic stations, the SWV structure of the upper crust is obtained in the coastal area of South China (CASC). A pattern of high to low SWVs is exhibited across the study area, with SWVs varying about 2.5–3.7 km/s from west to east. In the profile parallel to the coastline, lateral variations in the SWV correspond to the fault zone, indicating that the cutting depth of most coastal faults is approximately 10 km. Referring to previous studies, we deduce that the low SWV in most sub-areas can be interpreted as the joint effect of the sedimentary layer of the alluvial plain and the accumulation of underground heat flows, in addition to multistage fracturing tectonism. Moreover, the gradual change in the SWV in each profile from the surface to approximately 10 km is correlated with multiple invasions and the coverage of volcanic rocks, to a certain extent

Simplifying the Electrolyte Systems with the Functional Cosolvent

Simplifying the Electrolyte Systems with the Functional Cosolven

A MEMS-based Electronic Capsule for Time Controlled Drug Delivery in the Alimentary Canal

A controlled drug delivery system (CDDS) that is capable of releasing right dose of drug in the alimentary canal at the prespecified time has been designed, fabricated and tested. This micro-electro-mechanical system (MEMS)-based CDDS, in the form of an electronic capsule, has four major components: a timer module for controlling drug release, a driving unit for releasing drug to the alimentary canal, a microfluidic chamber for drug reservoir, and a power supply. Of these four components, the timer module is the most critical one as it needs to provide precise timing points for drug release and must have a simple mechanism for setting up timing parameters externally. To this end, a microcontroller has been employed to realize the timer, while an external resistance network is used to program the timing parameter. The performance of the electronic capsule is evaluated through in vitro and in vivo animal experiments. The preliminary results have confirmed that the electronic capsule can release drug reliably and effectively at the scheduled time points

New insights into the biodegradation of polylactic acid: from degradation to upcycling

Owing to its capability to be biosynthetic and biodegradable, polylactic acid (PLA) is considered as the most promising biopolymer among all plastic materials, which will play a crucial role as a potentially environmentally friendly material for a sustainable bioeconomy. However, its long life cycle indicates that it cannot be easily degraded in nature. Therefore, understanding the biodegradation mechanism of PLA is important to reduce impacts of waste plastic, waste disposal and alleviate the energy crisis. With the recent development of molecular biological techniques, some studies have confirmed that specific groups of microorganisms may aid the biodegradation process of PLA. Here, recent advances in the biodegradation of PLA (i.e., microbial and enzymatic degradation) and key factors affecting the degradation efficiency were reviewed. In addition, compared to complete degradation through mineralization, upcycling is also proposed as a more recyclable strategy for disposing the waste plastics.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Effects of mold, water damage and window pane condensation on adult rhinitis and asthma partly mediated by different odors

A questionnaire survey was performed in eight Chinese cities (40,279 adults participated; response rate 75%). There were questions on demographic information of the participants, allergic rhinitis, asthma, perceived odors and home environment. The majority were women (74.7%) and 12.2% were smokers; 6.6% reported allergic rhinitis and 1.6% reported asthma. Totally 38% reported stuffy odor; 24.6% unpleasant odor; 11.5% pungent odor and 10.4% mold odor. Reporting of condensation on window panes were common (62.1%); visible mold or dampness stains (21.9%) and water damage (14.7%) were less common. All dampness indicators were associated with allergic rhinitis and asthma (OR = 1.34–1.87) and all odors (OR = 1.79–6.17). All odors were associated with allergic rhinitis and asthma (OR = 1.23–4.51). Odor perception was partly a mediator of the effects of mold and dampness on allergic rhinitis (% of total effect mediated: 2.7–9.8%) and asthma (2.2–10.7%) when adjusting for other home environment factors. Increased mediation effects for allergic rhinitis (% of total effect mediated: 11.2–17.4%) and asthma (% of total effect mediated: 5.5–14.7%) were found for total odor score (0–8) as compared to the mediation effects for four single odors. In conclusion, mold and dampness in dwellings were associated with adult allergic rhinitis, asthma and odors. Different odors were related to allergic rhinitis and asthma. Some of the effects of mold/dampness on allergic rhinitis and asthma were indirect effect mediated by odors from damp buildings, but most of the effects were direct effects

Interaction effect of prenatal and postnatal exposure to ambient air pollution and temperature on childhood asthma

Background: Although mounting evidence has associated air pollution and environmental temperature with children's health problems, it is unclear whether there is an interaction between these factors on childhood asthma. Objectives: To explore the effects of temperature-pollution interactions during pre- and post-natal periods on asthma among pre-schoolers. Methods: A retrospective cohort study of 39,782 pre-schoolers was performed during 2010-2012, in seven cities in China. Exposure to three temperature indicators (TI) and three critical ambient air pollutants, including particulate matter with aerodynamic diameter <= 10 mu m (PM10), sulfur dioxide (SO2) and nitrogen dioxide (NO2) as proxies of industrial and vehicular air pollution, was estimated by an inverse distance weighted (IDW) method. Two-level logistical regression analysis was used to examine the association between both pre- and post-natal exposure and childhood asthma in terms of odds ratio (OR) and 95 % confidence interval (CI). Results: Asthma prevalence in pre-schoolers at age of 3-6 years (6.9 %) was significantly associated with traffic-related air pollutant (NO2) exposure, with ORs (95 % CI) of 1.17 (1.06, 1.28), 1.19 (1.05-1.34) and 1.16 (1.03-1.31) for an IQR increase in NO2 exposure during lifetime, pregnancy, and entire postnatal period respectively. Furthermore, childhood asthma was positively associated with exposure to increased temperature during lifetime, pregnancy, and entire postnatal period with ORs (95 % CI) = 1.89 (1.66, 2.16), 1.47 (1.34, 1.61), and 1.15 (1.11, 1.18) respectively, while was negatively associated with decreased temperatures. Childhood asthma was positively related with exposure to extreme heat days (EHD) during postnatal period particularly in first year of life respectively with ORs (95 % CI) = 1.23 (1.04, 1.46) and 1.26 (1.07, 1.47), but was not related with extreme cold days (ECD) exposure. A combination of high air pollutant levels and high temperatures significantly increased the risk of asthma during both pre- and post-natal periods. Strikingly, we found a significantly positive interaction of temperature and PM10 or SO2 on asthma risk among boys and younger children. Conclusions: Prenatal and postnatal exposure to ambient air pollution and high temperatures are independently and jointly associated with asthma risk in early childhood

Unusual Tetrahydropyridoindole-Containing Tetrapeptides with Human Nicotinic Acetylcholine Receptors Targeting Activity Discovered from Antarctica-Derived Psychrophilic Pseudogymnoascus sp. HDN17-933

Chemical investigation of the psychrophilic fungus Pseudogymnoascus sp. HDN17-933 derived from Antarctica led to the discovery of six new tetrapeptides psegymamides A–F (1–6), whose planar structures were elucidated by extensive NMR and MS spectrometric analyses. Structurally, psegymamides D–F (4–6) possess unique backbones bearing a tetrahydropyridoindoles unit, which make them the first examples discovered in naturally occurring peptides. The absolute configurations of structures were unambiguously determined using solid-phase total synthesis assisted by Marfey’s method, and all compounds were evaluated for their inhibition of human (h) nicotinic acetylcholine receptor subtypes. Compound 2 showed significant inhibitory activity. A preliminary structure–activity relationship investigation revealed that the tryptophan residue and the C-terminal with methoxy group were important to the inhibitory activity. Further, the high binding affinity of compound 2 to hα4β2 was explained by molecular docking studies