The hydrogen spillover effect (HSPE) plays an important role in heterogeneous catalysis and hydrogen storage as an interfacial phenomenon, which facilitates the improvement of hydrogen storage ...properties of porous nanomaterials and indirectly or directly affects the reaction performance of multiphase catalytic reactions. The setting-up of the word “hydrogen spillover” opened up a new area to gain insight into the dynamic behavior of migrating hydrogen atoms on a catalyst surface. However, a comprehensive understanding of the HSPE is still lacking. Today, the development of advanced characterization techniques provides increasingly valuable information to further our understanding of the HSPE. Based on these considerations, in this review, we hope to provide some answers to the question “What is hydrogen spillover and how do we recognize it?”. To do this, we will rely on advanced characterization techniques as well as experimental and theoretical studies. Then, we discuss in detail the influences of the HSPE on hydrogen storage performance and the important catalytic effects of the HSPE in catalysis. These effects will be reviewed by looking through the catalytic results obtained in many reactions in thermal catalysis, electrocatalysis, and photocatalysis. Furthermore, based on the application potential of hydrogen spillover, we present some preliminary research proposals and discuss the opportunities and challenges that remain to be faced in this research area.
The application of hydrogen spillover effect in hydrogen storage and catalysis was comprehensively summarized. Display omitted
•Support and metal active components play a crucial role on the hydrogen spillover process.•Characterizations of hydrogen spillover phenomena were summarized.•Mechanisms of hydrogen spillover were discussed in depth.•Application of hydrogen spillover in hydrogen storage and catalysis was illustrated.•Perspectives of future work on hydrogen spillover effect are proposed.
To develop and validate a radiomics nomogram based on T2-weighted imaging (T2WI) and apparent diffusion coefficient (ADC) features for the preoperative prediction of lymph node (LN) metastasis in ...rectal cancer patients.
One hundred and sixty-two patients with rectal cancer confirmed by pathology were retrospectively analyzed, who underwent T2WI and DWI sequences. The data sets were divided into training (n = 97) and validation (n = 65) cohorts. For each case, a total of 2,752 radiomic features were extracted from T2WI, and ADC images derived from diffusion-weighted imaging. A two-sample
-test was used for prefiltering. The least absolute shrinkage selection operator method was used for feature selection. Three radiomics scores (rad-scores) (rad-score 1 for T2WI, rad-score 2 for ADC, and rad-score 3 for the combination of both) were calculated using the support vector machine classifier. Multivariable logistic regression analysis was then used to construct a radiomics nomogram combining rad-score 3 and independent risk factors. The performances of three rad-scores and the nomogram were evaluated using the area under the receiver operating characteristic curve (AUC). Decision curve analysis (DCA) was used to assess the clinical usefulness of the radiomics nomogram.
The AUCs of the rad-score 1 and rad-score 2 were 0.805, 0.749 and 0.828, 0.770 in the training and validation cohorts, respectively. The rad-score 3 achieved an AUC of 0.879 in the training cohort and an AUC of 0.822 in the validation cohort. The radiomics nomogram, incorporating the rad-score 3, age, and LN size, showed good discrimination with the AUC of 0.937 for the training cohort and 0.884 for the validation cohort. DCA confirmed that the radiomics nomogram had clinical utility.
The radiomics nomogram, incorporating rad-score based on features from the T2WI and ADC images, and clinical factors, has favorable predictive performance for preoperative prediction of LN metastasis in patients with rectal cancer.
Trace ethylene poses a significant challenge during the storage and transportation of agricultural products, causing over-ripening, reducing shelf life, and leading to food waste. Zeolite-supported ...silver adsorbents show promise for efficiently removing trace ethylene. Herein, hierarchical Ag/NZ5(X) adsorbents were prepared via different ammonia modifications, which featured enhanced ethylene adsorption ability. Ag/NZ5(2.5) exhibited the largest capacity and achieved near-complete removal at room temperature with prolonged efficacy. Characterization results indicated that the ammonia modification led to the formation of a hierarchical structure in the zeolite framework, reducing diffusion resistance and increasing the accessibility of the active sites. Additionally, desilication effects increased the defectiveness, generating a stronger metal-support interaction and resulting in a higher metal dispersion rate. These findings provide valuable insights into the development of efficient adsorbents for removing trace ethylene, thereby reducing food waste and extending the shelf life of agricultural products.
Nature has provided a fantastic array of enzymes that are responsible for essential biochemical functions but not usually suitable for technological applications. Not content with the natural ...repertoire, protein engineering holds promise to extend the applications of improved enzymes with tailored properties. However, engineering of robust proteins remains a difficult task since the positive mutation library may not cooperate to reach the target function in most cases owing to the ubiquity of epistatic effects. The main demand lies in identifying an efficient path of accumulated mutations. Herein, we devised a computational strategy (greedy accumulated strategy for protein engineering, GRAPE) to improve the robustness of a PETase from Ideonella sakaiensis. A systematic clustering analysis combined with greedy accumulation of beneficial mutations in a computationally derived library enabled the redesign of a variant, DuraPETase, which exhibits an apparent melting temperature that is drastically elevated by 31 °C and a strikingly enhanced degradation toward semicrystalline poly(ethylene terephthalate) (PET) films (30%) at mild temperatures (over 300-fold). Complete biodegradation of 2 g/L microplastics to water-soluble products under mild conditions is also achieved, opening up opportunities to steer the biological degradation of uncollectable PET waste and further conversion of the resulting monomers to high-value molecules. The crystal structure revealed the individual mutation match with the design model. Concurrently, synergistic effects are captured, while epistatic interactions are alleviated during the accumulation process. We anticipate that our design strategy will provide a broadly applicable strategy for global optimization of enzyme performance.
•An easy method for preparing high performance porous silicon powder was developed by acid etching Al-Si alloy (Al-80%, Si-20%) powder for the first time.•In 1M LiPF6, EC:DMC=1:1(V/V) + 15% FEC, at ...first and 258th cycles, its discharge capacities were 2072mAhg-1Si and 1368 mAhg-1Si, respectively.•This new advance method is simple, low cost, and may have good potential for practical application in high energy lithium ion battery area.
We developed a novel, simple method to prepare porous silicon powder by acid etching Al–Si alloy powder. .The morphology and structure of the as-obtained material were investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscope (TEM), and BET methods. It was found that the porous silicon powder (size about 15μm) had a spongy structure, consisting of silicon nanobars with diameter about 50nm and length of 1.5μm. Its specific surface area was 102.8m2g−1. The electrochemical properties of porous silicon electrode were evaluated by measuring voltammograms and charge and discharge curves. The porous silicon electrode with ratio of porous Si powder:Super P:binder=1:1:1 was tested in button style lithium/Si cell. It was found that due to its ability to promote the formation of primal SEI film on the surface of electrodes, additive fluoroethylene carbonate (FEC) had an effect to improve the charge and discharge cycle stability of porous silicon electrodes. In solution 1M LiPF6, EC:DMC=1:1 (V/V) containing 15% FEC, the first charge and discharge capacities of porous silicon electrode were 3450mAhg−1 Si and 2072mAhg−1 Si respectively, at current density 100mAg−1. The discharge capacity retained 66% as 1368mAhg−1 Si after 258 charge and discharge cycles. In 1M LiPF6/EC:DEC=1:1 (V/V) solution, the charge and discharge capacities of porous silicon electrode in first cycle were 3396mAhg−1 Si and 2537mAhg−1 Si respectively. At 69th cycle, the discharge capacity remained 59% as 1497mAhg−1 Si. The high electrochemical performance of porous silicon powder could be attributed to its porous structure, which provides enough tiny space to buffer the huge volume change of Si anode during charging and discharging processes. The nano-size Si bars benefited the diffusion process of lithium in Li–Si alloy. Moreover, the firm connection between Si nanobars in spongy porous structure prevented the breakdown of porous Si particles. This new advanced method for preparing high performance porous Si material is simple and inexpensive, presenting a promising prospect for practical application.
The increasing cadmium (Cd) pollution in paddy fields has severely threatened China’s ecological and food safety. Cultivation of low Cd accumulation varieties to reduce Cd content in rice or ...cultivation of Cd-tolerant varieties for phytoremediation are considered effective methods to control Cd pollution in paddy fields. However, the underlying molecular mechanism of Cd absorption and transport by rice plants needs to be deciphered to cultivate these varieties. Here, we summarized the molecular mechanisms underlying Cd absorption and transport in rice, as well as the variation of Cd accumulation among rice varieties, the QTLs related to Cd accumulation in rice, and discusses the direction of future research.
Reactive distillation (RD) process is an innovative hybrid process combining reaction with distillation, which has recently come into sharp focus as a successful case of process intensification. ...Considered as the most representative case of process intensification, it has been applied for many productions, especially for production of ester compounds. However, such problems existing in the RD system for ester productions are still hard to solve, as the removal of the water which comes from the esterification, and the separation of the azeotropes of ester–alcohol (–water). Many methods have been studying on the process to solve the problems resulting in further intensification and energy saving. In this paper, azeotropic–reactive distillation or entrainer enhanced reactive distillation (ERD) process, reactive extractive distillation (RED) process, the method of co-production in RD process, pressure-swing reactive distillation (PSRD) process, reactive distillation–pervaporation coupled process (RD–PV), are introduced to solve the problems above, so the product(s) can be separated efficiently and the chemical equilibrium can be shifted. Dividing-wall column (DWC) structure and novel methods of loading catalyst are also introduced as the measures to intensify the process and save energy.
Atorvastatin ester (Ate) is a structural trim of atorvastatin that can regulate hyperlipidemia. The purpose of this study was to evaluate the lipid-lowering effect of Ate. Male Sprague Dawley (SD) ...rats were fed a high-fat diet for seven months and used as a hyperlipidemia model. The lipid level and liver function of the hyperlipidemia rats were studied by the levels of TG, TC, LDL, HDL, ALT, and AST in serum after intragastric administration with different doses of Ate. HE staining was used to observe the pathological changes of the rat liver and gastrocnemius muscle. The lipid deposits in the liver of rats were observed by staining with ORO. The genes in the rat liver were sequenced by RNA-sequencing. The results of the RNA-sequencing were further examined by qRT-PCR and western blotting. Biochemical test results indicated that Ate could obviously improve the metabolic disorder and reduce both the ALT and AST levels in serum of the hyperlipidemia rats. Pathological results showed that Ate could improve HFD-induced lipid deposition and had no muscle toxicity. The RNA-sequencing results suggested that Ate affected liver lipid metabolism and cholesterol, metabolism in the hyperlipidemia-model rats may vary via the PPAR-signaling pathway. The western blotting and qRT-PCR results demonstrated the Ate-regulated lipid metabolism in the hyperlipidemia model through the PPAR-signaling pathway and HMGCR expression. In brief, Ate can significantly regulate the blood lipid level of the model rats, which may be achieved by regulating the PPAR-signaling pathway and HMGCR gene expression.
Urbanization as a human activity alters the surface structure, modifying the urban ecological environment. In this study, the greenness, wetness, building index, and heatness of Dalian, a coastal ...city in northeast China, were extracted from the summer MODIS remote sensing data of 2010 and 2022, and the remote sensing ecological index (RSEI) was created based on spatial principal component analysis. The artificial impervious surface fraction (AISF) in Dalian was extracted to analyze the impact of urban expansion on urban ecological environment with the background of urbanization, the spatial and temporal change characteristics of the urban ecological environment in Dalian from 2010 to 2022 were thoroughly evaluated. The results show that: (1) Dalian's RSEI in 2010 and 2022 primarily ranged from 0.2 to 0.8. During 2010-2022, the RSEI in urban built-up areas decreased from 0.2-0.4 to 0-0.2. However, the areas of RSEI approaching 1 have increased significantly in the past ten years, mainly distributed in original forest land or ecological land in the northern areas of Dalian. (2) From 2010 to 2022, Dalian's natural environment showed a positive development in which, the area with enhanced ecological quality accounted for 59.09%; however, the proportion of ecological land with RSEI greater than 0.8 declined from 76.64% to 51.05% and the proportion of urban building land rose from 1.11% to 11.85%, demonstrating that urbanization has had a substantial impact on the urban natural environment and has altered the urban land use structure. (3) The AISF of Dalian's urban center area was found to exceed 70% and is centered in the south's densely built-up area. The urban expansion boundary extending from the city center to the surrounding territory has an AISF ranging from 20% to 70%. This study objectively analyzed the geographical and temporal features of the ecological environment, as well as the impact of urbanization, and offers constructive recommendations for urban building design and population distribution optimization.
Classical hypergeometric series are reformulated as analytic functions of their parameters (in both the numerator and the denominator). Then, the coefficient extraction method is applied to examine ...hypergeometric series transformations. Several new closed form evaluations are established for harmonic series containing multinomial coefficient (4n/n,n,n,n) and central binomial coefficient (2n/n). These results exclusively concern the alternating series of convergence rate “−1/4”.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
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