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The development of efficient and sustainable methods for reducing carbon dioxide (CO2) and converting it into valuable hydrocarbons has gained significant attention. In this study, researchers focused on Ti4+-doped metal-organic framework (MOF-74) photocatalysts. The incorporation of Ti4+ ions into the MOF-74 structure was achieved through a one-pot hydrothermal method. By replacing Zn2+ ions with Ti4+ ions in a substitutional manner, researchers have aimed to enhance the photocatalytic activity of the CO2 reduction. The obtained Ti4+-doped MOF-74 photocatalysts exhibited a significantly improved performance in the reduction of CO2 into carbon monoxide (CO). The doping of Ti4+ ions induced energy bands below the conduction band minimum (CBM) of MOF-74, extending the visible response range and enabling the photocatalysts to utilize a broader spectrum of light for catalytic reactions. This extension of the visible response range enables photocatalysts to utilize a broader spectrum of light for catalytic reactions. The incorporation of Ti4+ ions not only extends the visible response range but also suppresses charge carrier recombination. This work provides valuable insights into the design principles of MOF-based photocatalysts and paves the way for their practical implementation in addressing the energy crisis and reducing greenhouse gas emissions.
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Objective: This study aims to evaluate inpatient services in 49 tertiary comprehensive hospitals using indicators from the diagnosis related groups (DRG) payment system. Method: DRG data from 49 tertiary comprehensive hospitals were obtained from the quality monitoring platform for provincial hospitals, and relevant indicators were identified. The analytic hierarchy process (AHP) was used to compute the weight of each indicator. The rank sum ratio method was used to calculate the weight rank sum ratio (WRSR) value and the corresponding probit value of each hospital. The hospitals were divided into four grades based on the threshold value: excellent, good, fair, and poor. Results: Eight indicators of the 49 hospitals were scored, and the hospital rankings of indicators varied. The No. 1 hospital ranked first in the indicators of "total number of DRG", "number of groups", and "proportion of relative weights (RW) ≥ 2". The WRSR value of the No.1 hospital was the largest (0.574), and the WRSR value of the No. 44 hospital was the smallest (0.139). The linear regression equation was established: WRSRpredicted =-0.141+0.088*Probit, and the regression model was well-fitted (F = 2066.672, p < 0.001). The cut-off values of the three WRSRspredicted by the four levels were 0.167, 0.299, and 0.431, respectively. The 49 hospitals were divided into four groups: excellent (4), good (21), average (21), and poor (3). There were significant differences in the average WRSR values of four categories of hospitals (p < 0.05). Conclusion: There were notable variances in the levels of inpatient services among 49 tertiary comprehensive hospitals, and hospitals of the same category also showed different service levels. The evaluation results contribute to the health administrative department and the hospital to optimize the allocation of resources, improve the DRG payment system, and enhance the quality and efficiency of inpatient services.
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Grupos Diagnósticos Relacionados , Pacientes Internos , Humanos , HospitalesRESUMEN
Objective: Our aim was to explore the diagnostic value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI)-related quantitative parameters for benign and malignant nasal cavity and sinus tumors. Methods: A total of 78 patients with nasal sinus tumors admitted to People's Hospital of Qingdao Chengyang District in China were enrolled in our study, Of the patients, 41 were diagnosed as having benign tumors and 37 as having malignant tumors by pathological diagnosis. All patients received DCE-MRI scans before surgery to derive time-intensity curves (TICs) and related quantitative parameters (flux rate constant [Kep], transfer constant [Ktrans], extravascular volume fraction [Ve]). The diagnostic surgical pathology results were used as the gold standard to analyze the diagnostic effect of TIC and related quantitative parameters of DCE-MRI, and the receiver operating characteristic (ROC) curves were plotted to determine the values of each parameter in predicting nasal sinus tumors. Results: The percentage of class I in the benign group was significantly higher than in the malignant group (P < .05); the percentage of class III in the benign group was significantly lower than in the malignant group (P < .05); the percentage of class II in the 2 groups was comparable (P > .05). Kep, Ktrans and Ve in the benign group were 0.338±0.124, 0.061±0.035 and 0.532±0.138, respectively; Kep, Ktrans and Ve in the malignant group were 0.785±0.211, 0.441±0.125 and 0.327±0.048, respectively. The levels of Kep and Ktrans were significantly lower in the benign group than in the malignant group (all P < .05); the levels of Ve were significantly higher in the benign group than in the malignant group (P < .05). The optimal Kep cut-off value for predicting malignant nasal sinus tumors was 0.510 min-1, with a sensitivity of 81.4% and specificity of 89.5%; the optimal Ktrans cut-off value for predicting malignant nasal sinus tumors was 0.206 min-1, with a sensitivity of 84.3% and specificity of 89.7%; the optimal Ve cut-off value for predicting malignant nasal sinus tumors was 0.384 min-1, with a sensitivity of 71.8% and specificity of 82.4%. Conclusion: DCE-MRI-related quantitative parameters are ideal for the diagnosis of benign and malignant nasal sinus tumors. This modality provides more data for the identification of the nature of the tumor, and thus merits clinical promotion and application.
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Heat treatments are necessary sometimes in order to improve comprehensive properties of stainless steel cladding plate (SSCP). However, carbon atoms in carbon steel diffuse into stainless cladding during the heat treatment process, thus decreasing its corrosion resistance. In this paper, optical microscopy, scanning electron microscopy, and microhardness and shear testing were employed to characterize the microstructure and mechanical properties of the bonding interface in SSCP. Then, the corrosion resistance of the stainless steel cladding surface was evaluated by electrochemical tests. The results showed that the diffusion of carbon atoms played an important role in enhancing the bonding strength of SSCP, but might lead to intergranular sensitization of the cladding surface because of chromium carbide precipitation. Notably, this precipitation could be induced by quenching and tempering treatment, and hindered by solution treatment. Hence, the cladding surface on SSCP after single solution treatment possessed the superior corrosion resistance, and SSCP with continuous solution and tempering treatment exhibited the highest bonding strength.
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Modulation of the local electronic structure and microenvironment of catalytic metal sites plays a critical role in electrocatalysis, yet remains a grand challenge. Herein, PdCu nanoparticles with an electron rich state are encapsulated into a sulfonate functionalized metal-organic framework, UiO-66-SO3 H (simply as UiO-S), and their microenvironment is further modulated by coating a hydrophobic polydimethylsiloxane (PDMS) layer, affording PdCu@UiO-S@PDMS. This resultant catalyst presents high activity toward the electrochemical nitrogen reduction reaction (NRR, Faraday efficiency: 13.16%, yield: 20.24 µg h-1 mgcat. -1 ), far superior to the corresponding counterparts. Experimental and theoretical results jointly demonstrate that the protonated and hydrophobic microenvironment supplies protons for the NRR yet suppresses the competitive hydrogen evolution reaction reaction, and electron-rich PdCu sites in PdCu@UiO-S@PDMS are favorable to formation of the N2 H* intermediate and reduce the energy barrier of NRR, thereby accounting for its good performance.
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Recently, Zr- and Ti-based metal-organic frameworks (MOFs) have gathered increasing interest in the field of chemistry and materials science, not only for their ordered porous structure, large surface area, and high thermal and chemical stability, but also for their various potential applications. Particularly, the unique features of Zr- and Ti-based MOFs enable them to be a highly versatile platform for catalysis. Although much effort has been devoted to developing Zr- and Ti-based MOF materials, they still suffer from difficulties in targeted synthesis, especially for Ti-based MOFs. In this Feature Article, we discuss the evolution of Zr- and Ti-based MOFs, giving a brief overview of their synthesis and structures. Furthermore, the catalytic uses of Zr- and Ti-based MOF materials in the previous 3-5 years have been highlighted. Finally, perspectives on the Zr- and Ti-based MOF materials are also proposed. This work provides in-depth insight into the advances in Zr- and Ti-based MOFs and boosts their catalytic applications.
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The exposed facets of supported catalysts play a crucial role in catalysis; however, they are usually ignored and related studies remain rare. Herein, we have fabricated a series of sandwich-structured metal-organic framework composites, denoted ZIF-8X @Pd@ZIF-8 (x represents the morphology of ZIF-8 core, i.e., ZIF-8C exposing (100) facet, ZIF-8RD exposing (110) facet, and ZIF-8TRD exposing mixed (100) and (110) facets), featuring Pd nanoparticles deposited on the specific crystal facets of ZIF-8 core, for hydrogenation of p-chloronitrobenzene. The Pd electronic state is tailored by the ZIF-8 core, where more electron-deficient Pd is found in ZIF-8C @Pd@ZIF-8 than that in ZIF-8RD @Pd@ZIF-8, leading to discriminative adsorption of the -NO2 and -Cl groups of p-chloronitrobenzene. Consequently, ZIF-8C @Pd@ZIF-8 exhibits excellent activity (97.6 %) and selectivity (98.1 %) to p-chloroaniline. This work highlights crystal facet engineering of supports to modulate the microenvironment and electronic state of supported metal nanoparticles, offering a promising avenue to enhanced catalysis.
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Selective hydrogenation with high efficiency under ambient conditions remains a long-standing challenge. Here, a yolk-shell nanostructured catalyst, PdAg@ZIF-8, featuring plasmonic PdAg nanocages encompassed by a metal-organic framework (MOF, namely, ZIF-8) shell, has been rationally fabricated. PdAg@ZIF-8 achieves selective (97.5%) hydrogenation of nitrostyrene to vinylaniline with complete conversion at ambient temperature under visible light irradiation. The photothermal effect of Ag, together with the substrate enrichment effect of the catalyst, improves the Pd activity. The near-field enhancement effect from plasmonic Ag and optimized Pd electronic state by Ag alloying promote selective adsorption of the -NO2 group and therefore catalytic selectivity. Remarkably, the unique yolk-shell nanostructure not only facilitates access to PdAg cores and protects them from aggregation but also benefits substrate enrichment and preferential -NO2 adsorption under light irradiation, the latter two of which surpass the core-shell counterpart, giving rise to enhanced activity, selectivity, and recyclability.
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The marine applicability of adsorbents intended for recovering uranium from seawater is crucial. For such applicability, the materials must exhibit anti-biofouling properties, seawater pH adaptability (pH~8), and salt tolerance. Extracting uranium from seawater is a long-term project; hence, biofouling, high salt concentrations, and weak alkaline environments negatively affect the adsorption of uranium and damage the recovered materials. Most studies on the extraction of uranium from seawater focus on increasing the adsorption capacity of the employed adsorbent, while its marine applicability is neglected. In the present study, three types of guanidine polymer (GP)-modified acrylic fibers were prepared to investigate the impact of the introduced structure on the marine applicability of the fibers. After screening, the introduction of polyhexamethylene biguanidine (PHMB) is observed to produce PAO-PHMB-A, characterized by excellent marine applicability. The enhanced properties include high antimicrobial activity (109 CFU/mL, 99.71%), good salt tolerance, and optimal adsorption at a pH of 8. Owing to the synergistic effect of its functional groups, the PAO-PHMB-A material exhibits excellent adsorption performance (525.89 mg/g), as well as high selectivity and durability. More importantly, long-term marine tests revealed that PAO-PHMB-A shows a remarkable uranium adsorption capacity (30 d, 3.19 mg/g) and excellent antibacterial activity. Considering its excellent marine applicability and good adsorption performance, the PAO-PHMB-A material developed in this work could serve as a potential adsorbent for engineering applications associated with uranium recovery from seawater.
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Incrustaciones Biológicas , Uranio , Adsorción , Polímeros , Agua de MarRESUMEN
Exploiting two-dimensional (2D) materials with natural band gaps and anisotropic quasi-one-dimensional (quasi-1D) carrier transport character is essential in high-performance nanoscale transistors and photodetectors. Herein, the stabilities, electronic structures and carrier mobilities of 2D monolayer ternary metal iodides MLaI5(M = Mg, Ca, Sr, Ba) have been explored by utilizing first-principles calculations combined with numerical calculations. It is found that exfoliating MLaI5monolayers are feasible owing to low cleavage energy of 0.19-0.21 J m-2and MLaI5monolayers are thermodynamically stable based on phonon spectra. MLaI5monolayers are semiconductors with band gaps ranging from 2.08 eV for MgLaI5to 2.51 eV for BaLaI5. The carrier mobility is reasonably examined considering both acoustic deformation potential scattering and polar optical phonon scattering mechanisms. All MLaI5monolayers demonstrate superior anisotropic and quasi-1D carrier transport character due to the striped structures. In particular, the anisotropic ratios of electron and hole mobilities along different directions reach hundreds and tens for MLaI5monolayers, respectively. Thus, the effective electron-hole spatial separation could be actually achieved. Moreover, the absolute locations of band edges of MLaI5monolayers have been aligned. These results would provide fundamental insights for MLaI5monolayers applying in nano-electronic and optoelectronic devices.
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The early evolutionary pattern and molecular adaptation mechanism of alpine Parnassius butterflies to high altitudes in Qinghai-Tibet Plateau are poorly understood up to now, due to difficulties in sampling, limited sequence data, and time calibration issues. Here, we present large-scale transcriptomic datasets of eight representative Parnassius species to reveal the phylogenetic timescale and potential genetic basis for high-altitude adaptation with multiple analytic strategies using 476 orthologous genes. Our phylogenetic results strongly supported that the subgenus Parnassius formed a well-resolved basal clade, and the subgenera Tadumia and Kailasius were closely related in the phylogenetic trees. In addition, molecular dating analyses showed that the Parnassius began to diverge at about 13.0 to 14.3 million years ago (middle Miocene), correlated with their hostplant's spatiotemporal distributions, as well as geological and palaeoenvironmental changes of the Qinghai-Tibet Plateau. Moreover, the accelerated evolutionary rate, candidate positively selected genes and their potentially functional changes were detected, probably contributed to the high-altitude adaptation of Parnassius species. Overall, our study provided some new insights into the spatiotemporally evolutionary pattern and high altitude adaptation of Parnassius butterflies from the extrinsic and intrinsic view, which will help to address evolution, biodiversity, and conservation questions concerning Parnassius and other butterfly species.
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The development of two-dimensional (2D) lateral heterostructures (LHs) with the powerful tunability of electronic properties will be of great realistic significance for next-generation device applications. Herein, we report the novel 2D MoX2 and MoX2H2 (X = As or Sb) monolayer materials with excellent stability. Using first-principles calculations, we demonstrated that 2D MoX2 layers possess the metallic characteristic while the full surface hydrogenation effect would play a role in stabilizing the 2D lattices and lead to band gap openings of 0.83 and 0.50 eV for the 2D MoAs2H2 and MoSb2H2, respectively. In addition, our results suggest that the 2D MoAs2H2 and MoSb2H2 can serve as the 'building blocks' to construct the seamless LHs exhibiting excellent thermal and dynamical stability. The obtained nL-MoAsSb LHs enable the fully tunable band gap engineering behavior with linear tendency as a function of the width of the in-plane components. The phase transition from direct to in-direct band gap was also confirmed in the LHs as the crucial value of n = 3. In view of the type-II band alignment and efficient carrier separation in nL-MoAsSb, the predicted MoX2H2 and nL-MoAsSb LHs not only highlight the promising candidates for 2D pristine materials, but also paves the way for the realization of practical integrating device applications.
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The chemical environment of metal nanoparticles (NPs) possesses significant influence on their catalytic performance yet is far from being well understood. Herein, tiny Pd NPs are encapsulated into the pore space of metal-organic frameworks (MOFs), UiO-66-X (X = H, OMe, NH2 , 2OH, 2OH(Hf)), affording Pd@UiO-66-X composites. The surface microenvironment of the Pd NPs is readily modulated by pore wall engineering, via the functional group and metal substitution in the MOFs. Consequently, the catalytic activity of Pd@UiO-66-X follows the order of Pd@UiO-66-OH > Pd@UiO-66-2OH(Hf) > Pd@UiO-66-NH2 > Pd@UiO-66-OMe > Pd@UiO-66-H toward the hydrogenation of benzoic acid. It is found that the activity difference is not only ascribed to the distinct charge transfer between Pd and the MOF, but is also explained by the discriminated substrate adsorption energy of Pd@UiO-66-X (-OH < -2OH(Hf) < -NH2 < -OMe < -H), based on CO-diffuse reflectance infrared Fourier transform spectra and density-functional theory (DFT) calculations. The Pd@UiO-66-OH, featuring a high Pd electronic state and moderate adsorption energy, displays the highest activity. This work highlights the influence of the surface microenvironment of guest metal NPs, the catalytic activity of which is dominated by electron transfer and the adsorption energy, via the systematic substitution of metal and functional groups in host MOFs.
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Exploring ultrathin two-dimensional (2D) solid electrolytes with fast ion transport is highly desirable in nanoelectronics, ionic devices and various energy storage systems, following the rapid scaling of devices to the nanometer scale. Herein, two-dimensional (2D) metal trihalides MX3 (ScCl3, ScBr3, AsI3, ScI3, YBr3, SbI3, YI3 and BiI3) with intrinsic atomic pore structures have been examined and found to be promising as realistic 2D solid electrolytes. Through examining the binding interactions and the diffusion barriers of monolayer MX3-ion (Li+, Na+, K+, Mg2+, and Ca2+) systems by utilizing first principles calculations, it is found that MX3-ion complexes are energetically favorable and the energy barriers of some MX3-ion systems are comparable to or even smaller than those of the conventional solid electrolyte systems. More significantly, the short diffusion time of Na+ and K+ ions in some monolayers MX3 at the nanosecond (ns) or even at the sub-ns scale indicates fast ion transport. In terms of practical applications, ultrafast Li+ travelling in the timescale of sub-ns to ns and Na+ in several tens ns in few-layer MX3 is achieved. In addition, the insulating nature of wide band gaps for MX3 is maintained during the ion transport, which is essential for solid electrolytes. These theoretical results provide fundamental guidance that MX3 materials with natural atomic pores are realistic candidates for 2D solid electrolytes with broad applications in ionic devices and energy storage devices.
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Deep phylogeny involving arthropod lineages is difficult to recover because the erosion of phylogenetic signals over time leads to unreliable multiple sequence alignment (MSA) and subsequent phylogenetic reconstruction. One way to alleviate the problem is to assemble a large number of gene sequences to compensate for the weakness in each individual gene. Such an approach has led to many robustly supported but contradictory phylogenies. A close examination shows that the supermatrix approach often suffers from two shortcomings. The first is that MSA is rarely checked for reliability and, as will be illustrated, can be poor. The second is that, to alleviate the problem of homoplasy at the third codon position of protein-coding genes due to convergent evolution of nucleotide frequencies, phylogeneticists may remove or degenerate the third codon position but may do it improperly and introduce new biases. We performed extensive reanalysis of one of such "big data" sets to highlight these two problems, and demonstrated the power and benefits of correcting or alleviating these problems. Our results support a new group with Xiphosura and Arachnopulmonata (Tetrapulmonata + Scorpiones) as sister taxa. This favors a new hypothesis in which the ancestor of Xiphosura and the extinct Eurypterida (sea scorpions, of which many later forms lived in brackish or freshwater) returned to the sea after the initial chelicerate invasion of land. Our phylogeny is supported even with the original data but processed with a new "principled" codon degeneration. We also show that removing the 1673 codon sites with both AGN and UCN codons (encoding serine) in our alignment can partially reconcile discrepancies between nucleotide-based and AA-based tree, partly because two sequences, one with AGN and the other with UCN, would be identical at the amino acid level but quite different at the nucleotide level.
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A porphyrinic metal-organic framework (MOF), PCN-222(Fe), was found to exhibit sound activity and selectivity to cyclohexanone and cyclohexanol (known as KA oil) toward cyclohexane oxidation. Remarkably, hydrophobicity engineering of the MOF pore walls led to significantly enhanced activity and selectivity to KA oil, far superior to that of the homogeneous porphyrin catalyst.
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: Novel fluffy Fe@α-Fe2O3 core-shell nanowires have been synthesized using the chemical reaction of ferrous sulfate and sodium borohydride, as well as the post-annealing process in air. The coercivity of the as-synthesized nanowires is above 684 Oe in the temperature range of 5 to 300 K, which is significantly higher than that of the bulk Fe (approximately 0.9 Oe). Through the annealing process in air, the coercivity and the exchange field are evidently improved. Both the coercivity and the exchange field increase with increasing annealing time (TA) and reach their maximum values of 1,042 and 78 Oe, respectively, at TA = 4 h. The magnetic measurements show that the effective anisotropy is increased with increasing the thickness of theα-Fe2O3 by annealing. The large values of coercivity and exchange field, as well as the high surface area to volume ratio, may make the fluffy Fe@α-Fe2O3 core-shell nanowire a promising candidate for the applications of the magnetic drug delivery, electrochemical energy storage, gas sensors, photocatalysis, and so forth.
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The purpose of this study was to estimate the spatial and temporal variation of microalgae in the South China Sea and to demonstrate the environmental factors controlling the diversity of microalgae by GIS (geographic information system)-based analysis of 18S rDNA sequences. Six 18S rDNA libraries were constructed from environmental samples collected at different sites in the study area, and more than 600 18S rDNA sequences were determined. The rDNA sequence data were then analyzed by DIVA-GIS software to display the spatial and temporal variation of phytoplankton's composition. It was shown that the autotrophic eukaryotic plankton dominated over the heterotrophic cells in most of our clone libraries, and the dominating phytoplankton was Dinophyceae except for Bacillariophyta at the Xiamen harbor. The percentages of these two groups were controlled by water temperature and salinity. Our results also revealed that the species composition of Chlorophyta showed a close relationship with latitude, changing from Prasinophyceae at the high latitude to Trebouxiophyceae at the low latitude. Several newly classified picoplankton lineages were first uncovered in the South China Sea, including the pico-sized green alga Ostreococcus sp. and Picochlorum eukaryotum, and picobiliphytes, which was just discovered in 2007 with unknown affinities to other eukaryotes. Their spatial and temporal variation were also analyzed and discussed.
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Proteínas Algáceas/genética , Chlorophyta/genética , ADN Ribosómico/análisis , Agua de Mar , Secuencia de Bases , China , Chlorophyta/clasificación , Chlorophyta/metabolismo , Océano Pacífico , Filogenia , TemperaturaRESUMEN
OBJECTIVE: To detect cholesteryl ester transfer protein (CETP) levels, frequencies of CETP D442G and I 14A mutations and characteristics of abnormal lipids in patients with cardio-cerebro vascular diseases. METHODS: Ninety-four myocardial infarction (MI) patients, 110 stroke patients and 335 healthy controls were selected. The CETP concentration was determined using ELISA. The CETP activity was measured using a substrate of (14)C-radiolabeled discoidal bilayer particles. The CETP gene mutations were detected by PCR-RFLP. RESULTS: The CETP concentrations in the MI and stroke group, were higher than those in the controls. The gene mutation frequencies of D442G in the MI, stroke and control group were 3.5%, 3.6% and 5%, respectively, and the frequencies of I 14A were 1.05%, 0.91% and 1%, respectively. One case of D442G homozygote was detected in the healthy group. The frequency of two CETP gene mutations showed no significant difference among the patients and controls. The CETP concentration and activity in subjects with CETP mutations were one-third of those in the control group. The level of HDL-C, apo-A1 increased in the mutation subjects, while the TG level decreased. CONCLUSIONS: The CETP level increased significantly in patients with cardio-cerebrovascular diseases. The carriers of CETP deficiency had CETP and lipid abnormalities.