The coronavirus disease (COVID-19) has become a global public health threaten. A series of strict prevention and control measures were implemented in China, contributing to the improvement of air ...quality. In this study, we described the trend of air pollutant concentrations and the incidence of COVID-19 during the epidemic and applied generalized additive models (GAMs) to assess the association between short-term exposure to air pollution and daily confirmed cases of COVID-19 in 235 Chinese cities. Disease progression based on both onset and report dates as well as control measures as potential confounding were considered in the analyses. We found that stringent prevention and control measures intending to mitigate the spread of COVID-19, contributed to a significant decline in the concentrations of air pollutants except ozone (O3). Significant positive associations of short-term exposure to air pollutants, including particulate matter with diameters ≤2.5 μm (PM2.5), particulate matter with diameters ≤10 μm (PM10), and nitrogen dioxide (NO2) with daily new confirmed cases were observed during the epidemic. Per interquartile range (IQR) increase in PM2.5 (lag0-15), PM10 (lag0-15), and NO2 (lag0-20) were associated with a 7% 95% confidence interval (CI): (4–9), 6% 95% CI: (3–8), and 19% 95% CI: (13–24) increase in the counts of daily onset cases, respectively. Our results suggest that there is a statistically significant association between ambient air pollution and the spread of COVID-19. Thus, the quarantine measures can not only cut off the transmission of virus, but also retard the spread by improving ambient air quality, which might provide implications for the prevention and control of COVID-19.
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•There is a statistically significant association between ambient air pollution and the spread of COVID-19.•The lag days from onset date to report date of COVID-19 were taken into account.•Quarantine measures can not only cut off the transmission of virus, but also retard the spread by improving air quality.
Short-term exposure to air pollutants, including PM2.5, PM10, NO2, may contribute to an increase in the counts of daily onset cases. Stringent prevention and control measures can not only cut off the transmission of virus, but also retard the virus spread by reducing air pollution, which might provide implications for the prevention and control of COVID-19.
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•The preparation approach for TiO2/AC-5-Ag composites photocatalysts is convenient.•TiO2/AC-5-Ag shows a large specific surface area and wider light absorption.•TiO2/AC-5-Ag exhibits ...much higher CO2 adsorption capacity than pristine TiO2.•The CO2 photo-reduction efficiency of TiO2/AC-5-Ag is better compared to that of TiO2.
Improving CO2 adsorption capacity, suppressing the recombination of carriers, and extending the light absorption range are key challenges for obtaining high efficiency photocatalytic conversion of CO2 with H2O as reducing agent. In this paper, we proposed using noble metal Ag and activated carbon obtained from biomass with high CO2 adsorption capacity to modify TiO2, thus assembling a TiO2/AC-Ag ternary composite photocatalyst via using ultrasonic and situ photodeposition methods. The TiO2/AC-Ag displayed six times increase in CO yield compared to that of pristine TiO2. The enhanced CO2 photoconversion performance can be attributed to the following three factors: (1) The activated carbon not only leads to enhanced CO2 adsorption capacity due to its properties and high surface area but also makes the electron transfer to its surface due to similar conductivity to metals derived from diverse electronic structures of activated carbon, thereby suppressing the recombination of photo-generated electron and hole pairs. (2) The oxidation reaction sites of H2O are located on the surface of TiO2 and the reduction reaction sites of CO2 are on the surface of activated carbon; the effective separation of two reaction sites remarkably inhibited the reverse reaction during CO generation. (3) The surface plasmon resonance (SPR) of Ag enables the materials to absorb light in a broader spectrum.
ABSTRACT
We present extensive observations of SN 2018zd covering the first ∼450 d after the explosion. This SN shows a possible shock-breakout signal ∼3.6 h after the explosion in the unfiltered ...light curve, and prominent flash-ionization spectral features within the first week. The unusual photospheric temperature rise (rapidly from ∼12 000 to above 18 000 K) within the earliest few days suggests that the ejecta were continuously heated. Both the significant temperature rise and the flash spectral features can be explained by the interaction of the SN ejecta with the massive stellar wind ($0.18^{+0.05}_{-0.10}\, \rm M_{\odot }$), which accounts for the luminous peak ($L_{\rm max} = 1.36\pm 0.63 \times 10^{43}\, \rm erg\, s^{-1}$) of SN 2018zd. The luminous peak and low expansion velocity (v ≈ 3300 km s−1) make SN 2018zd like a member of the LLEV (luminous SNe II with low expansion velocities) events originating due to circumstellar interaction. The relatively fast post-peak decline allows a classification of SN 2018zd as a transition event morphologically linking SNe IIP and SNe IIL. In the radioactive-decay phase, SN 2018zd experienced a significant flux drop and behaved more like a low-luminosity SN IIP both spectroscopically and photometrically. This contrast indicates that circumstellar interaction plays a vital role in modifying the observed light curves of SNe II. Comparing nebular-phase spectra with model predictions suggests that SN 2018zd arose from a star of $\sim 12\, \rm M_{\odot }$. Given the relatively small amount of 56Ni ($0.013\!-\!0.035 \rm M_{\odot }$), the massive stellar wind, and the faint X-ray radiation, the progenitor of SN 2018zd could be a massive asymptotic giant branch star that collapsed owing to electron capture.
Precut fistulotomy is of interest as one of the salvage techniques for selective bile duct cannulation using endoscopic retrograde cholangiopancreatography. Of the various endoscopic treatments ...reported to date for bleeding associated with papillotomy incision, endoscopic hemostasis treatment with a novel self-assembling peptide (SAP) matrix-forming gel (TDM-621) (3-D Matrix Ltd., Tokyo, Japan) remains only insufficiently reported in the literature.
We herein report 6 cases of precut fistulotomy-related bleeding successfully treated with endoscopic hemostasis treatment with TDM-621, i.e., 5 and 1 cases during and after precut fistulotomy, respectively, in 2 males and 4 females aged 68-96 years (mean age, 85 years), 3 of whom had been on antithrombotic drugs. Types of bleeding treated included oozing bleeding (
= 5) and oozing bleeding from a visible vessel (
= 1). In all cases, complete hemostasis was achieved with TDM-621 without causing rebleeding.
Endoscopic hemostasis with TDM-621 may prove effective for precut fistulotomy-related bleeding and represent a potential modality of first choice in hemostasis. In addition, endoscopic hemostasis with combined modality therapy using TDM-621 and endoscopic hemoclips may prove effective for bleeding from visible vessels.
Exciton-polaritons, formed by the strong coupling between excitons and cavity-confined photons, are the building blocks of polaritonic devices. In this work, we report experimental realization of an ...all-optically controlled dynamic superlattice for polaritons working in the ultraviolet wavelength range at room temperature. The optical superlattice was realized on a one-dimensional (1D) ZnO microrod using an array of periodically arranged laser spots. Polaritonic mini-band features were clearly observed by both momentum- and real-space imaging spectroscopy. By controlling the periodicity of the laser spots, we demonstrated that the band structures of polaritons can be well controlled by external lasers. Theoretically, by extending the Kronig-Penney model to the polariton system, we calculated the polaritonic mini-bands and found it to be in good agreement with our experimental observations. By imaging the polariton flow in real space, the lifetime of polaritons and their relationship with their exitonic fractions were also extracted. The polaritonic superlattices demonstrated in this work are fully reconfigurable and optically controlled, and our results could thus stimulate the development of polaritonic all-optical devices.
An optically-controlled and fully reconfigurable dynamic superlattice was realized on a one-dimensional ZnO microrod for exciton-polaritons.
Bleeding from gastric cancer may lead to severe anemia and hypovolemic shock, and can be a life-threatening condition in affected patients; thus, achieving hemostasis is essential to improving their ...clinical course. While endoscopic hemostasis is recommended as the hemostatic modality of first choice, endoscopic hemostasis involving the endoscopic mucosal resection (EMR) technique is also being used, though under-reported. An 85-year-old man diagnosed with bleeding from gastric cancer was raced to our hospital for hemostasis. Emergency esophagogastroduodenoscopy (EGD) revealed a 45 mm-sized elevated lesion involving the coagula due to dripping bleeding from the surface of the posterior wall of the gastric lower body. EMR was performed without any technical difficulty, and hemostasis was achieved immediately. The patient was discharged without rebleeding. This case appears to support the usefulness of EMR as an emergency endoscopic hemostatic modality for severe bleeding from early gastric cancer.
While the differential diagnosis of duodenal adenocarcinoma versus adenoma remains the key to determining treatment strategies in patients with suspected duodenal adenocarcinoma, the role of linked ...color imaging (LCI) in their differential diagnosis remains insufficiently documented. In this case, esophagogastroduodenoscopy (EGD) was performed on a 67-year-old man for anemia, which revealed a 20-mm-sized, whitish, partially reddish, pedunculated lesion located in the duodenal bulb on white light imaging. Using LCI, the lesion was highlighted as a whitish, pedunculated lesion with its central and inferior areas depicted as orangish and reddish, respectively. Endoscopic mucosal resection was performed on the suspicion of an adenocarcinoma for biopsy and endoscopic diagnosis. Histological examination revealed the lesion to be an adenocarcinoma contained in an adenoma: papillary, type 0-Ip, measuring 20x20 mm, pTis (M), involving no lymphovascular invasion. This case appears to underpin the usefulness of LCI in the differential diagnosis of duodenal adenocarcinoma.
We present photometric and spectroscopic observations of the type Ibn supernova (SN) 2019uo, the second ever SN Ibn with flash ionization (He ii, C iii, N iii) features in its early spectra. SN ...2019uo displays a rapid post-peak luminosity decline of 0.1 mag day−1 similar to most of the SNe Ibn, but is fainter ( mag) than a typical SN Ibn and shows a color evolution that places it between SNe Ib and the most extreme SNe Ibn. SN 2019uo shows P-cygni He i features in the early spectra which gradually evolve and become emission dominated post peak. It also shows faster evolution in line velocities as compared to most other members of the type Ibn subclass. The bolometric light curve is fairly well described by a 56Ni + circumstellar interaction model.
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