Synthesis, Characterization, and Electromagnetic Wave Absorption Properties of Composites of Reduced Graphene Oxide with Porous LiFe₅O₈ Microspheres

A novel three-dimensional composite of reduced graphene oxide sheets and porous LiFe₅O₈ microspheres was fabricated via a facile, green, and highly tunable strategy, and the microstructure, composition, and microwave-absorbing performances of the rGO/porous LiFe₅O₈ composite were characterized and investigated. The experimental results indicate that the porous LiFe₅O₈ microspheres are dispersed on the thin rGO sheets uniformly. Compared with the pure LiFe₅O₈ particles and porous LiFe₅O₈ microspheres, the as-prepared rGO/porous LiFe₅O₈ composites exhibit outstanding microwave-absorbing performances including efficient bandwidth and reflection loss. The rGO/porous LiFe₅O₈ composite (S-50) displays a maximum reflection loss of −53.4 dB at 12.2 GHz with a coating layer thickness of 2.2 mm and a broad effective bandwidth of 3.5 GHz (from 10.4 to 13.9 GHz). The outstanding microwave-absorbing performances are assigned to employing magnetic microflowers with multi-interfaces to improve impedance matching, which is ascribed to strong relaxation loss, electrical loss, and magnetic loss. This further confirms that the rGO/porous LiFe₅O₈ composites could be potential candidates for lightweight microwave-absorbing materials

Utilizing GRACE-based groundwater drought index for drought characterization and teleconnection factors analysis in the North China Plain

Traditional drought monitoring methods rely on ground station data, which are difficult to reflect large-scale dynamic drought information. Thus, Gravity Recovery and Climate Experiment (GRACE) gravity satellite technology is applied to monitor and estimate drought, which can provide new data sources and measurement instruments for drought investigation. In this study, the GRACE groundwater drought index (GGDI) was utilized as a metric for assessing drought. The temporal evolution, spatial distribution and trend characteristics of drought were comprehensively identified in the North China Plain (NCP) from 2003 to 2015. Subsequently, the links between GGDI and teleconnection factors were clarified using cross wavelet transform technology. The results indicated that: (1) the quantitative results of GRACE were reliable and robust for drought evaluation; (2) the most serious drought event occurred from August 2013 to September 2014, with an average GGDI value of −1.36; (3) the monthly and seasonal droughts were increasing based on the modified Mann-Kendall (MMK) trend test method; and (4) the cross wavelet transform revealed that teleconnection factors had significant influences on drought evolution, and El Niño-Southern Oscillation (ENSO) had the strongest impact on drought in the NCP. This study sheds new insights into drought monitoring by using GRACE gravity satellite, which can be applied in other regions as well

A new copula-based standardized precipitation evapotranspiration streamflow index for drought monitoring

Traditional univariate drought indices are likely to be insufficient for reflecting the comprehensive information of drought. Thus, it is of great significance to construct a comprehensive drought index for drought monitoring under the consideration of the complexity of meteorological and hydrological conditions in a changing environment. In this study, a new copula-based Standardized Precipitation Evapotranspiration Streamflow Index (SPESI) was proposed, which can synthetically characterize meteorological and hydrological drought. The temporal change, spatial distribution and return period of drought were comprehensively identified in the Yellow River Basin (YRB) from 1961 to 2015. Subsequently, the links between SPESI and teleconnection factors were revealed using cross wavelet transform technology. The results indicated that: (1) based on the combination of meteorological and hydrological drought information, the constructed SPESI could capture the occurrence, duration and termination of drought sensitively and effectively; (2) the seasonal and annual droughts were increasing in the YRB during 1961–2015, with different temporal change characteristics in each subzone; (3) the month and season with the most serious drought was June and summer, with an average SPESI value of −1.23 and −0.89, respectively; (4) Frank-copula was considered to be the best-fitted copula function in the YRB; and (5) the cross wavelet transform illustrated that teleconnection factors had strong influences on the evolution of drought in the YRB, and the impacts of El Niño-Southern Oscillation (ENSO), Arctic Oscillation (AO) and sunspot on the droughts were stronger than those of Pacific Decadal Oscillation (PDO). This study can provide a reliable and effective multivariate index for drought monitoring, which can also be applied in other regions

Additional file 1 of Radiomics-based discrimination of coronary chronic total occlusion and subtotal occlusion on coronary computed tomography angiography

Supplementary Material

Parameter optimization of SWMM model using integrated Morris and GLUE methods

The USEPA (United States Environmental Protection Agency) Storm Water Management Model (SWMM) is one of the most extensively implemented numerical models for simulating urban runoff. Parameter optimization is essential for reliable SWMM model simulation results, which are heterogeneously sensitive to a variety of parameters, especially when involving complicated simulation conditions. This study proposed a Genetic Algorithm-based parameter optimization method that combines the Morris screening method with the generalized likelihood uncertainty estimation (GLUE) method. In this integrated methodology framework, the Morris screening method is used to determine the parameters for calibration, the GLUE method is employed to narrow down the range of parameter values, and the Genetic Algorithm is applied to further optimize the model parameters by considering objective constraints. The results show that the set of calibrated parameters, obtained by the integrated Morris and GLUE methods, can reduce the peak error by 9% for a simulation, and then the multi-objective constrained Genetic Algorithm reduces the model parameters’ peak error in the optimization process by up to 6%. During the validation process, the parameter set determined from the combination of both is used to obtain the optimal values of the parameters by the Genetic Algorithm. The proposed integrated method shows superior applicability for different rainfall intensities and rain-type events. These findings imply that the automated calibration of the SWMM model utilizing a Genetic Algorithm based on the combined parameter set of both has enhanced model simulation performance

Facile Synthesis of Flowerlike LiFe₅O₈ Microspheres for Electrochemical Supercapacitors

Facile synthesis of porous and hollow spinel materials is very urgent due to their extensive applications in the field of energy storage. In present work, flowerlike porous LiFe₅O₈ microspheres etched for 15, 30, and 45 min (named as p-LFO-15, p-LFO-30, and p-LFO-45, respectively) are successfully synthesized through a facile chemical etching method based on bulk LiFe₅O₈ (LFO) particles as precursors, and they are applied as electrode materials for high-performance electrochemical capacitors. In particular, the specific surface area of p-LFO-45 reaches 46.13 m² g^–1, which is 112 times greater than that of the unetched counterpart. Therefore, the p-LFO-45 electrode can achieve a higher capacitance of 278 F g^–1 at a scan rate of 5 mV s^–1 than the unetched counterpart. Furthermore, the p-LFO-45 electrode presents a good cycling stability with 78.3% of capacitive retention after 2000 cycles, which is much higher than that of the unetched LFO particles (66%). Therefore, the flowerlike porous LFO microspheres are very promising candidate materials for supercapacitor applications

DataSheet_1_Association between sarcopenia-related traits and cardiovascular diseases: a bi-directional Mendelian randomization study.zip

BackgroundThe two geriatric diseases, sarcopenia and cardiovascular disease (CVD), often coexist, yet the causal relationship is unclear. However, few studies focus on the effect of muscle mass on CVD. This comprehensive study is dedicated to unearthing the potential connection between sarcopenia-related traits and CVD at the genetic level.MethodA two-sample bi-directional Mendelian randomization (MR) study was conducted. In the first stage, we performed MR analysis regarding coronary heart disease (CHD), stroke, and myocardial infarction (MI) as exposure factors to reveal their effect on appendicular lean mass (ALM) and hand grip strength. In the second stage, we reverse the position of exposures and outcomes. The inverse variance weighted (IVW) method was used as the primary approach to reveal the potential causation between the exposure and outcome.ResultsThe results of the IVW method revealed a negative causal effect of ALM on CHD (OR = 0.848, 95% CI = 0.804 to 0.894, p = 8.200E-10), stroke (OR = 0.931, 95% CI = 0.890 to 0.975, p = 2.220E-03), and MI (OR = 0.810, 95% CI = 0.694 to 0.901, p = 1.266E-13). Additionally, the left-hand grip strength is a significant protective factor for CHD (OR = 0.737, 95% CI = 0.601 to 0.904, p = 3.353E-03) and MI (OR = 0.631, 95% CI = 0.515 to 0.765, p = 2.575E-06), but is not causally linked to the stroke (OR = 0.971, 95% CI =0.829 to 1.139, p = 0.720). Meanwhile, the same conclusion about the effect of right-hand grip strength on CHD (OR = 0.681, 95% CI = 0.558 to 0.832, p = 1.702E-05), MI (OR = 0.634, 95% CI = 0.518 to 0.776, p = 9.069E-06), and stroke (OR = 1.041, 95% CI = 0.896 to 1.209, p = 0.604) was obtained. However, no significant causal effect of CVD (CHD, stroke, MI) on sarcopenia-related traits (ALM, handgrip strength) was found.ConclusionThere is a unidirectional causal relationship between sarcopenia and CVD. The loss of muscle mass and strength has a significant causal role in promoting the occurrence and development of CVD, providing a reference for the prevention and treatment of comorbidities in older people.</p

Comprehensive evaluation of hydrological drought and its relationships with meteorological drought in the Yellow River basin, China

Under the background of global warming, the acceleration of water cycle process will aggravate the risk of hydrological drought in the river basin. The Yellow River basin (YRB) is the most severely affected area by drought in China's major river basins, so it is particularly important to comprehensively evaluate the hydrological drought and explore its relationships with meteorological drought in the YRB. In this study, the Standardized Streamflow Index (SSI) was adopted as a hydrological drought index, and the evolution characteristics of hydrological drought were comprehensively evaluated in the YRB from 1961 to 2015. The duration and severity of hydrological drought events were identified based on run theory, and the copula functions with the highest goodness of fit (GOF) were used to investigate the drought return period. Finally, the Standardized Precipitation Evapotranspiration index (SPEI) was adopted as a meteorological drought index, and the relationships between hydrological and meteorological drought were revealed by cross wavelet transform method. The results indicated that: (1) drought showed an increasing trend in the YRB from 1961 to 2015, while the worst drought occurred in 1997; (2) the trend characteristic of drought was different in each subzone; (3) the most severe drought lasted for 32 months, with drought severity of 43.29, and drought return period of 23.26 years; (4) Frank-copula was considered to be the best-fitted copula function in the YRB; and (5) the cross wavelet transform illustrated that there was a positive correlation between hydrological and meteorological drought, and the phase angle relationships indicated that meteorological drought occurred earlier than hydrological drought in the YRB

Soft Material Approach to Induce Oxidative Stress in Mesenchymal Stem Cells for Functional Tissue Repair

Biomimicking hydrogel-based cell culture platforms with physiologically relevant stiffness are powerful tools to modulate the behaviors of stem cells. Herein, the use of fibronectin-conjugated polyacrylamide (PAA) hydrogel biointerface is exploited to modulate the intracellular oxidative stress of human bone marrow derived mesenchymal stem cells (MSCs). We show that compliant culture surface with kPa range matrix stiffness can augment the expression level of reactive oxygen species (ROS) in MSCs by approximately 2–4 fold compared with cells grown on conventional FN coated glass control surface in a noncytotoxic manner. Via an unbiased proteomics approach and mechanistic studies, we show that the secretion level of a sub series of “mechano-sensitive” chemokines and trophic factors is heavily dependent on the PAA matrix stiffness mediated ROS level. Importantly, the secretome harvested from the cells that were grown on the PAA hydrogel was found to enhance wound healing in both in vitro and in vivo full thickness mouse excisional wound model. The devised “soft approach” to induce oxidative stress in MSCs is posited to pave the way for novel cell-free therapeutic interventions targeting a wide variety of diseases and to foster functional tissue repair

Systematic Analysis of Lysine Acetylation in the Halophilic Archaeon <i>Haloferax mediterranei</i>

Lysine acetylation is a reversible and highly regulated post-translational modification that plays a critical role in regulating many aspects of cellular processes, both in bacteria and in eukaryotes. However, this modification has not been systematically studied in archaea. Herein, we report the lysine acetylome of a model haloarchaeon, <i>Haloferax mediterranei.</i> Using immunoaffinity enrichment and LC–MS/MS analysis, we identified 1017 acetylation sites in 643 proteins, accounting for 17.3% of the total proteins in this haloarchaeon. Bioinformatics analysis indicated that lysine acetylation mainly distributes in cytoplasm (94%) and participates in protein biosynthesis and carbon metabolism. Specifically, the acetylation of key enzymes in PHBV biosynthesis further suggested that acetylation plays a key role in the energy and carbon storage. In addition, a survey of the acetylome revealed a universal rule in acetylated motifs: a positively charged residue (K, R, or H) located downstream of acetylated lysine at the positions +1, +2, or +3. Interestingly, we identified acetylation in several replication initiation proteins Cdc6; mutation on the acetylated site of Cdc6A destroyed the Autonomous Replication Sequence (ARS) activity of its adjacent origin <i>oriC1</i>. Our study indicates that lysine acetylation is an abundant modification in <i>H. mediterranei</i>, and plays key roles in the processes of replication, protein biosynthesis, central metabolism, and carbon storage. This acetylome of <i>H. mediterranei</i> provides opportunities to explore the physiological role of acetylation in halophilic archaea