AbstractThis study estimated the wind gust factor and turbulence intensity for hurricane winds that are modeled as a nonstationary non-Gaussian process. The estimation considered the time-varying ...mean wind velocity, and the time–frequency decomposition using S-transform characterized the time-varying amplitude and frequency content of the fluctuating wind. Winds simulated by applying a newly developed algorithm were used to augment the sample size. Results indicate that the standardized power spectral density function of hurricane winds can be represented in terms of the reduced frequency but with time-varying mean wind velocity. The standardized fluctuating wind is only weakly non-Gaussian; the average skewness and kurtosis coefficients are not very sensitive to whether the 10-or 60-min time-varying mean wind speed is considered. The assessed relation between the gust factor and turbulence intensity indicates that such a relationship is influenced by whether the instantaneous aspect of the nonstationary process is considered. There is large uncertainty in the developed relationship. By removing samples associated with a low mean wind velocity, the largest value of the estimated gust factor decreases. The consideration of the non-Gaussian aspect of the fluctuating wind to estimate the gust factor could be important as turbulence intensity increases.
Large-scale, highly integrated and low-power-consuming hardware is becoming progressively more important for realizing optical neural networks (ONNs) capable of advanced optical computing. ...Traditional experimental implementations need N
units such as Mach-Zehnder interferometers (MZIs) for an input dimension N to realize typical computing operations (convolutions and matrix multiplication), resulting in limited scalability and consuming excessive power. Here, we propose the integrated diffractive optical network for implementing parallel Fourier transforms, convolution operations and application-specific optical computing using two ultracompact diffractive cells (Fourier transform operation) and only N MZIs. The footprint and energy consumption scales linearly with the input data dimension, instead of the quadratic scaling in the traditional ONN framework. A ~10-fold reduction in both footprint and energy consumption, as well as equal high accuracy with previous MZI-based ONNs was experimentally achieved for computations performed on the MNIST and Fashion-MNIST datasets. The integrated diffractive optical network (IDNN) chip demonstrates a promising avenue towards scalable and low-power-consumption optical computational chips for optical-artificial-intelligence.
Thoracic endovascular aortic repair (TEVAR) is an emerging therapy for thoracic aortic pathologies. However, the role of left subclavian artery (LSA) revascularisation in patients with LSA coverage ...in TEVAR has not been established. A systematic review and meta-analysis was done to investigate the effect of LSA revascularisation in TEVAR when the LSA was covered.
PubMed, Embase, and the Cochrane Library were searched to find relevant randomised controlled trials (RCTs) and cohort studies. The Cochrane Risk of Bias Tool and Newcastle–Ottawa Scale was used to evaluate the methodological quality of RCTs and cohort studies respectively. Relative risks (RRs) with 95% confidence intervals (CIs) were calculated to express differences for dichotomous outcomes. Random effects models were used to combine outcomes for studies with I2 > 50%; otherwise, fixed effects models were used. Subgroup analyses and sensitivity analyses were performed to further validate the results.
Sixteen cohort studies with a total of 2591 patients were included in this systematic review and meta-analysis. The average score of the included studies was 7.56. Of the included patients, the peri-operative stroke rate was 6.8% (n = 176/2591). The peri-operative stroke rates of the with and without LSA revascularisation groups were 5.4% and 7.8%, respectively. Compared with no LSA revascularisation, patients with LSA revascularisation had a significantly lower peri-operative stroke rate (RR 0.61; 95% CI 0.45–0.82; I2 = 20%) and peri-operative spinal cord ischaemia (SCI) rate (RR 0.59; 95% CI 0.39–0.90; I2 = 0). No significant difference was found between the with and without LSA revascularisation groups with respect to peri-operative mortality (RR 0.86; 95% CI 0.60–1.21; I2 = 35%) and peri-operative paraplegia (RR 0.81; 95% CI 0.45–1.44; I2 = 17%).
The results of this review reveal that LSA revascularisation was associated with significantly lower peri-operative stroke and SCI rates. LSA revascularisation should be recommended for patients with LSA coverage in TEVAR. High quality RCTs are needed to further validate the conclusion.
Microplastics can alter microbial communities and enzymatic activities in soils. However, the influences of microplastics on soil carbon cycling which driven by microbial communities remain largely ...unknown. In this study, we investigated the effects of polyester microfiber (PMF) and natural organic matter（OM）on soil microbial communities, carbon-degraded enzymes, and carbon accumulation through an incubation experiment. Our results showed that the addition of PMF increased the activities of soil cellulase and laccase but did not impact soil bacterial and fungal communities too much. However, the addition of OM largely altered soil microbial communities and the activities of carbon-degraded enzymes, then mitigated the PMF effects on the activities of soil cellulase and laccase. On the other hand, greater alpha diversity of bacterial community attached on PMF was observed than those in the surrounding soils. The interaction of PMF and OM increased the richness of bacterial community in soils and on PMF. More importantly, we observed that the accumulation of natural organic carbon in soils reduced with increasing PMF. Thus, our results provide valuable insights into the effects of microplastics on soil organic carbon dynamics and microbial communities, and further work is required to clarify the biochemical processes at the surface of microplastics.
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•Polyester microfiber increased the richness of soil microbial communities.•The α-diversity of bacterial on polyester microfiber was higher than that in soils.•Polyester microfiber increased the activities of soil laccase and cellulase.•Polyester microfiber decreased the accumulation of natural organic carbon in soils.
Our current understanding of the cosmic star formation history at
z
> 3 is primarily based on UV-selected galaxies (Lyman-break galaxies, i.e., LBGs). Recent studies of
H
-dropouts (HST-dark ...galaxies) have revealed that we may be missing a large proportion of star formation that is taking place in massive galaxies at
z
> 3. In this work, we extend the
H
-dropout criterion to lower masses to select optically dark or faint galaxies (OFGs) at high redshifts in order to complete the census between LBGs and
H
-dropouts. Our criterion (
H
> 26.5 mag & 4.5 < 25 mag) combined with a de-blending technique is designed to select not only extremely dust-obscured massive galaxies but also normal star-forming galaxies (typically
E
(
B
−
V
) > 0.4) with lower stellar masses at high redshifts. In addition, with this criterion, our sample is not contaminated by massive passive or old galaxies. In total, we identified 27 OFGs at
z
phot
> 3 (with a median of
z
med
= 4.1) in the GOODS-ALMA field, covering a wide distribution of stellar masses with log(
M
⋆
/
M
⊙
) = 9.4 − 11.1 (with a median of log(
M
⋆med
/
M
⊙
) = 10.3). We find that up to 75% of the OFGs with log(
M
⋆
/
M
⊙
) = 9.5 − 10.5 were neglected by previous LBGs and
H
-dropout selection techniques. After performing an optical-to-millimeter stacking analysis of the OFGs, we find that rather than being limited to a rare population of extreme starbursts, these OFGs represent a normal population of dusty star-forming galaxies at
z
> 3. The OFGs exhibit shorter gas depletion timescales, slightly lower gas fractions, and lower dust temperatures than the scaling relation of typical star-forming galaxies. Additionally, the total star formation rate (SFR
tot
= SFR
IR
+ SFR
UV
) of the stacked OFGs is much higher than the SFR
UV
corr
(SFR
UV
corrected for dust extinction), with an average SFR
tot
/SFR
UV
corr
= 8 ± 1, which lies above (∼0.3 dex) the 16–84th percentile range of typical star-forming galaxies at 3 ≤
z
≤ 6. All of the above suggests the presence of hidden dust regions in the OFGs that absorb all UV photons, which cannot be reproduced with dust extinction corrections. The effective radius of the average dust size measured by a circular Gaussian model fit in the
uv
plane is
R
e(1.13 mm)
= 1.01 ± 0.05 kpc. After excluding the five LBGs in the OFG sample, we investigated their contributions to the cosmic star formation rate density (SFRD). We found that the SFRD at
z
> 3 contributed by massive OFGs (log(
M
⋆
/
M
⊙
) > 10.3) is at least two orders of magnitude higher than the one contributed by equivalently massive LBGs. Finally, we calculated the combined contribution of OFGs and LBGs to the cosmic SFRD at
z
= 4 − 5 to be 4 × 10
−2
M
⊙
yr
−1
Mpc
−3
, which is about 0.15 dex (43%) higher than the SFRD derived from UV-selected samples alone at the same redshift. This value could be even larger, as our calculations were performed in a very conservative way.
Polybrominated diphenyl ethers (PBDEs) have been shown to disrupt thyroid hormone (TH) functions on experimental animals, and one of the proposed disruption mechanisms is the competitive binding of ...PBDE metabolites to TH transport proteins. In this report, a nonradioactive, site-specific fluorescein–thyroxine (F–T4) conjugate was designed and synthesized as a fluorescence probe to study the binding interaction of hydroxylated PBDEs to thyroxine-binding globulin (TBG) and transthyretin (TTR), two major TH transport proteins in human plasma. Compared with free F–T4, the fluorescence intensity of TTR-bound conjugate was enhanced by as much as 2-fold, and the fluorescence polarization value of TBG-bound conjugate increased by more than 20-fold. These changes provide signal modulation mechanisms for F–T4 as a fluorescence probe. Based on fluorescence quantum yield and lifetime measurements, the fluorescence intensity enhancement was likely due to the elimination of intramolecular fluorescence quenching of fluorescein by T4 after F–T4 was bound to TTR. In circular dichroism and intrinsic tryptophan fluorescence measurements, F–T4 induced similar spectroscopic changes of the proteins as T4 did, suggesting that F–T4 bound to the proteins at the T4 binding site. By using F–T4 as the fluorescence probe in competitive binding assays, 11 OH–PBDEs with different levels of bromination and different hydroxylation positions were assessed for their binding affinity with TBG and TTR, respectively. The results indicate that the binding affinity generally increased with bromine number and OH position also played an important role. 3-OH–BDE-47 and 3′-OH–BDE-154 bound to TTR and TBG even stronger, respectively, than T4. With rising environmental level and high bioaccumulation capability, PBDEs have the potential to disrupt thyroid homeostasis by competitive binding with TH transport proteins.
We present the experimental demonstration of what are to our knowledge the first two-dimensional planar plasmonic lenses formed by an array of spatially varying cross-shaped apertures in a metallic ...film for Fresnel-region focusing. The design utilizes localized surface plasmon resonances occurring inside the apertures, accompanied by an aperture geometry dependent phase shift, to achieve the desired spatial phase modulation in the transmitted field. The performance of lenses with different design configurations was evaluated using a confocal scanning optical microscope, and the effects of diffraction on the optical response of these microscale devices are discussed.
Soilborne microplastics can persist for decades and their consequences are of growing concern. Therefore, it is important to explore the feasible approaches for eliminating microplastic effects on ...soil properties. Through an incubation experiment, we evaluate the effects of thermal treatment on physical properties, enzymatic activities and microbial communities in polyester-microfibers contaminated soils. The effects of polyester-microfiber levels (0%, 0.1%, 0.3% and 1.0% of soil dry weight) on soil properties were detected under not heated (PMF), heated (mPMF) and added with natural-organic-matters (OM) following heated (mPMF+OM) conditions. Our results showed that 1.0% mPMF soil had lower bulk density and higher mean weight diameter than 0% mPMF soil, akin to PMF soils. Meanwhile, great volumes of < 30 µm pores in 0.3% and 1.0% mPMF soils were observed than that in 0% mPMF soil. Additionally, the dose-effects of melted polyester-microfiber on soil enzymatic activities and bacterial communities were still observed following thermal treatment, even under the OM added condition. Furthermore, our results demonstrated that polyester microfibers influenced soil microbial communities and functioning via altering specific soil physical properties, regardless of thermal treatment or not. Results of this study should be useful to guide further develop viable methods for remediating soils contaminated with microplastics.
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•The effects of melted PMF and PMF on soil physical properties were similar.•Melted PMF still influenced soil enzymatic activity and bacterial community.•OM could not eliminate the melted PMF effects on soil bio-physical properties.•PMF influenced microbial community via altering soil specific physical properties.
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