Time series of satellite data provide unparalleled information on the response of vegetation to climate variability. Detecting subtle changes in vegetation over time requires consistent ...satellite-based measurements. Here, the impact of sensor degradation on trend detection was evaluated using Collection 5 data from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensors on the Terra and Aqua platforms. For Terra MODIS, the impact of blue band (Band 3, 470nm) degradation on simulated surface reflectance was most pronounced at near-nadir view angles, leading to a 0.001–0.004yr−1 decline in Normalized Difference Vegetation Index (NDVI) under a range of simulated aerosol conditions and surface types. Observed trends in MODIS NDVI over North America were consistent with simulated results, with nearly a threefold difference in negative NDVI trends derived from Terra (17.4%) and Aqua (6.7%) MODIS sensors during 2002–2010. Planned adjustments to Terra MODIS calibration for Collection 6 data reprocessing will largely eliminate this negative bias in detection of NDVI trends.
► This paper evaluates the impact of Terra/MODIS degradation on NDVI time series. ► Artifacts from degradation may be incorrectly attributed to changes in vegetation. ► Aqua MODIS data should be used until C6 reprocessing addresses degradation artifacts.
High reactivity and sintering resistance are key factors to design outstanding CH4 oxidation noble metal-based supported catalysts. Herein, we prepared and screened 0.5 wt% Pd/Al2O3 (among 0.3–3 wt% ...Pd loading) samples prepared by wet impregnation with very high CH4 catalytic activity. The hydrophobic modification of γ-Al2O3 support by triethoxyoctylsilane (TEOOS) exhibits further enhanced activity for CH4 oxidation, ca. T90 decrease from 375 °C to 350 °C with enhanced concentration of surface Pd0 sites. Besides, after Al2O3 protection layer deposition over the 0.5 wt% Pd/Al2O3 by atomic layer deposition (ALD), distinct higher temperature stability due to reduced agglomeration was demonstrated.
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•0.5%wtPd/Al2O3 catalysts with hydrophilic and atomic layer deposition modification are prepared.•0.5%wtPd loading on hydrophobic Al2O3 shows best CH4 oxidation reactivity with T90 at 350 °C.•0.5 wt% Pd/Al2O3 after depositing Al2O3 protection layer by ALD shows best sintering resistance.•Structural and oxidation performance of the catalysts are well characterized.
Umami is one of the basic taste sensing, and represents the recognition of N-containing compounds capable of evaluating the nutritious contents of food. Although several sensors have been developed, ...the assessment of umami intensity remains challenging due to the limitations of sensor specificity, sensitivity, and performance stability. Here we present a biomimetic conical nanochannels system integrated with Venus flytrap (VFT) domain from human umami receptor T1R1 subunit to meet the concern. By taking advantage of sensitive transmembrane ionic flux change, the functional nanochannels could precisely distinguish umami substances from other tastants. Detailed mechanism analysis reveals that specific binding between T1R1 and umami substances triggers local conformation change and surface charge redistribution of the protein, which modulates the ionic current. This study initiates the application of nanochannel device in taste perception, which could help to disclose umami perception mechanism and screen new umami substances.
Depression is a common psychological problem in adolescents worldwide. Although the World Health Organization recommends that members of this population engage in physical activity to reduce ...depressive symptoms, compliance with this recommendation is often low. Furthermore, although behavioral activation (BA) is recommended as a treatment for adolescents with depression, the reported effect size is small. Compared with traditional exercises, gamified physical activity (GPA) can be particularly appealing to adolescents because it is perceived as an enjoyable experience. In this study, we integrated BA and GPA to create behavioral activation play therapy (BAPT). We designed a clinical trial to investigate the feasibility, acceptability, and effectiveness of this treatment in adolescents with depression. This study is a randomized controlled trial (RCT) with a three-arm, assessor-blinded design, conducted to validate the effectiveness and applicability of BAPT for treating adolescent with depression. We will recruit 258 participants and randomly assign them to a BAPT group, BA group, or GPA group using a ratio of 1:1:1. Based on conventional strategies for treatment and care, the three groups will receive nine BAPT sessions, nine BA sessions, or nine GPA sessions, respectively. We will compare the outcomes of the BAPT with those of the BA and GPA interventions. This is the first RCT to explore the effectiveness and applicability of BAPT in adolescents with depression. This study will provide evidence that may help to decrease depressive symptoms in adolescents, and will demonstrate the treatment effectiveness in terms of increasing levels of physical activity, reducing the rate of non-suicidal self-injury behaviors, and improving sleep quality. We will also assess the presence of side effects and the treatment adherence of patients receiving BAPT.
Interfacial ligand passivation engineering has recently been recognized as a promising avenue, contributing simultaneously to the optoelectronic characteristics and moisture/operation tolerance of ...perovskite solar cells. To further achieve a win‐win situation of both performance and stability, an innovative conjugated aniline modifier (3‐phenyl‐2‐propen‐1‐amine; PPEA) is explored to moderately tailor organolead halide perovskites films. Here, the conjugated PPEA presents both “quasi‐coplanar” rigid geometrical configuration and distinct electron delocalization characteristics. After a moderate treatment, a stronger dipole capping layer can be formed at the perovskite/transporting interface to achieve favorable banding alignment, thus enlarging the built‐in potential and promoting charge extraction. Meanwhile, a conjugated cation coordinated to the surface of the perovskite grains/units can form preferably ordered overlapping, not only passivating the surface defects but also providing a fast path for charge exchange. Benefiting from this, a ≈21% efficiency of the PPEA‐modified solar cell can be obtained, accompanied by long‐term stability (maintaining 90.2% of initial power conversion efficiency after 1000 h testing, 25 °C, and 40 ± 10 humidity). This innovative conjugated molecule “bridge” can also perform on a larger scale, with a performance of 18.43% at an area of 1.96 cm2.
An innovative interfacial modifier, namely, 3‐phenyl‐2‐propen‐1‐amine (t‐PPEA) is developed for perovskite solar cells to overcome the dilemma of the trade‐off between transport and stability of the device, with a unique “quasi‐coplanar” rigid geometrical configuration and distinct electron delocalization characteristic.
Herein, a simple one‐pot way is designed to prepare a type of multifunctional metal–organic framework (MOF)‐based hybrid nanogels by in situ hybridization of dopamine monomer in the skeleton of MnCo. ...The resultant hybrid nanoparticles (named as MCP) show enhanced photothermal conversion efficiency in comparison with pure polydopamine or MnCo nanoparticles (NPs) synthesized under a similar method and, therefore, show great potential for photothermal therapy (PTT) in vivo. The MCP NPs are expected to possess T
1 positive magnetic resonance imaging ability due to the high‐spin Mn‐N6 (S = 5/2) in the skeleton of MnCo. To improve the therapy efficiency as a PTT agent, the MCP NPs are further modified with functional polyethylene glycol (PEG) and thiol terminal cyclic arginine–glycine–aspartic acid peptide, respectively: the first one is to increase the stability, biocompatibility, and blood circulation time of MCP NPs in vivo; the second one is to increase the tumor accumulation of MCP‐PEG NPs and improve their therapeutic efficiency as photothermal agent.
A one‐pot method to prepare multifunctional hybrid nanogels by in situ hybridization of dopamine monomer in the skeleton of MnCo is reported. After surface modification with polyethylene glycol and targeting molecules, the resultant hybrid nanoparticles with enhanced photothermal conversion efficiency demonstrate improved blood circulation time and tumor accumulation and, therefore, show great potential to kill tumor in vivo under near infrared (NIR) irradiation.
Summary
Movement of the conductive earth medium in the ambient geomagnetic field can generate an electromotive force and a motional induction current, which further cause the disturbances of the ...electromagnetic (EM) fields. Such a mechanoelectric coupling is known as the motional induction (MI) effect and has been proposed to be a possible mechanism for the generation of the observed EM signals during earthquakes. In this paper, we study the EM responses to an earthquake source due to such a MI effect in a 2-D horizontally layered model. First we transform the governing equations that couple the elastodynamic equations and Maxwell equations into a set of first-order ordinary depth-dependent differential equations. Then we solve the seismic and EM responses to a moment tensor source. Finally, we transform the 2-D seismic and EM responses to 3-D responses using a simple amplitude correction method. We conduct several numerical examples to investigate the properties of the EM signals generated by the earthquake source. The results show that two types of EM signals can be observed. The first one is the coseismic electric/magnetic field that accompanies the seismic P and S waves as well as the Rayleigh wave. The second one is the early EM signal which arrives before the P wave. The numerical results show that the EM signals change with the inclination angle of the geomagnetic field, the azimuth angle between the wave propagation plane and the geomagnetic vertical plane, and the medium conductivity. Increase in the conductivity can enhance the coseismic electric and magnetic signals. Our simulation also shows that an EM wave can be generated by a seismic wave at the interface separating two different media. The radiation pattern of the interface EM wave generated by a P wave is similar to that of a horizontal electric dipole located on the interface.
In this letter, a novel digital pre‐distortion (DPD) scheme for an end‐to‐end forward link (FL) channel in a satellite internet network (SIN) is first proposed. It aims at the unprecedented challenge ...of the model of non‐stationary (NS) cascade response consisting of channel fading and non‐linear behaviour of onboard payload. Unlike most existing schemes, the proposed DPD scheme explores a new model to describe the distortion with improved band‐limited memory polynomial (BLMP) by the equivalent response. To decrease the complexity of utilization, the authors design a new strategy to divide the unified non‐stationary situation into several different stationary situations. Meanwhile, a space‐time‐frequency stationary window function (STF‐WF) is proposed to compensate for the signal distortion. The experimental results demonstrate that the proposed schemes realize maximum total degradation (TD) gain by 15%.
In this letter, a novel digital pre‐distortion (DPD) scheme for an end‐to‐end forward link (FL) channel in a satellite internet network (SIN) is first proposed. Unlike most existing schemes, the proposed DPD scheme explores a new model to describe the distortion with improved band‐limited memory polynomial (BLMP) by the equivalent response. To decrease the complexity of utilization, we design a new strategy to divide the unified non‐stationary (NS) situation into several different stationary situations. Meanwhile, a space‐time‐frequency stationary window function (STF‐WF) is proposed to compensate for the signal distortion.
Surface shortwave net radiation (SSNR) is a key component of the surface radiation budget. In this paper, we refined a direct estimation approach to retrieve daily SSNR estimates from combined Terra ...and Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) data. The retrieved MODIS SSNR estimates were validated against measurements at seven stations of the Surface Radiation Budget Network. We also compared the MODIS retrievals with three existing SSNR products: the Clouds and the Earth's Radiant Energy System (CERES) products, the North American Regional Reanalysis (NARR) data, and the ERA-Interim reanalysis data from the European Centre for Medium-Range Weather Forecasts. MODIS data at 1 km were upscaled to mitigate the mismatch between site measurements and satellite retrievals. Among the four data sets, the aggregated MODIS retrievals agreed best with in situ measurements, with a root-mean-square error (rmse) of 23.1 W/m 2 and a negative bias of 6.7 W/m 2 . The CERES products have a slightly larger rmse of 24.2 W/m 2 and a positive bias of 7.6 W/m 2 . Both reanalysis data (NARR and ERA-Interim) overestimate daily SSNR and have much larger uncertainties. Monthly satellite SSNR data are more accurate than daily values, and the scaling issue in validating monthly MODIS SSNR retrievals is also less prominent. Averaged with a window size of 23 km, the two MODIS sensors can estimate monthly SSNR with an rmse error of 11.6 W/m 2 , representing an improvement of 2.4 W/m 2 over the CERES products.
Site-specific analysis of protein glycosylation is important for biochemical and clinical research efforts. Glycopeptide analysis using liquid chromatography−collision-induced dissociation/electron ...transfer dissociation mass spectrometry (LC−CID/ETD-MS) allows simultaneous characterization of the glycan structure and attached peptide site. However, due to the low ionization efficiency of glycopeptides during electrospray ionization, 200−500 fmol of sample per injection is needed for a single LC−MS run, which makes it challenging for the analysis of limited amounts of glycoprotein purified from biological matrixes. To improve the sensitivity of LC−MS analysis for glycopeptides, an ultranarrow porous layer open tubular (PLOT) LC column (2.5 m × 10 μm i.d.) was coupled to a linear ion trap (LTQ) collision-induced dissociation/electron transfer dissociation mass spectrometer to provide sensitive analysis of N-linked protein glycosylation heterogeneity. The potential of the developed method is demonstrated by the characterization of site-specific glycosylation using haptoglobin (Hpt) as a model protein. To limit the amount of haptoglobin to low picomole amounts of protein, we affinity purified it from 1 μL of pooled lung cancer patient plasma. A total of 26 glycoforms/glycan compositions on three Hpt tryptic glycopeptides were identified and quantified from 10 LC−MS runs with a consumption of 100 fmol of Hpt digest (13 ng of protein, 10 fmol per injection). Included in this analysis was the determination of the glycan occupancy level. At this sample consumption level, the high sensitivity of the PLOT LC−LTQ-CID/ETD-MS system allowed glycopeptide identification and structure determination, along with relative quantitation of glycans presented on the same peptide backbone, even for low abundant glycopeptides at the ∼100 amol level. The PLOT LC−MS system is shown to have sufficient sensitivity to allow characterization of site-specific protein glycosylation from trace levels of glycosylated proteins.
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