Selectively separating CH4 from N2 in natural gas purification is extremely important, but challenging. Herein, a copper‐based metal–organic framework (MOF) NKMOF‐8‐Me with inert pore environment was ...reported for efficient CH4/N2 separation. Adsorption results show that this material owns the highest CH4 uptake (1.76 mmol/g) and initial adsorption heat (Qst0) of CH4 (28.0 kJ/mol) as well as difference in Qst0 (9.1 kJ/mol) among all materials with good water stability. Breakthrough experiments confirm that this MOF can completely separate the CH4/N2 mixture with the highest CH4/N2 breakthrough selectivity (7.8) reported so far. Theoretical calculations reveal the separation mechanism is the short average distance between CH4 and pore wall, resulting in a stronger adsorption affinity for CH4. In addition, this MOF exhibits highly structural stability and regeneration. These results guarantee this MOF as a promising adsorbent for the recovery of CH4 from coalbed methane.
In this feature article, we discuss in detail developmental bottleneck issues in Raman spectroscopy in its early stages and surface-enhanced Raman spectroscopy (SERS) in the past four decades. We ...divide SERS research into two different directions with different targets. Fundamental research is extending the limits of SERS to single-molecule, sub-nanometer resolution and femtosecond processes. In contrast, practical research is expanding the range of applications with the aim of providing versatile analytical tools for surface, materials, life, environmental, forensic and food sciences and also commercial instruments for use in daily life. In the second direction there have continually been many complex bottlenecks to be overcome. We attempt to enumerate the key issues in detail and also describe the achievements made to overcome the bottlenecks. In the last, but not least important part, we discuss the remaining bottlenecks and possible strategies for overcoming them to enable SERS to be an even more powerful and versatile technique.
This feature article discusses developmental bottleneck issues in surface Raman spectroscopy in its early stages and surface-enhanced Raman spectroscopy (SERS) in the past four decades and future perspectives.
Hypoxia is a parameter related to many diseases. Ratiometric hypoxia probes often rely on a combination of an O2‐insensitive fluorophore and an O2‐sensitive phosphor in a polymer matrix, which ...require high cost and multi‐step synthesis of transition metal complexes. The two‐chromophore hypoxia probes encounter unfavorable energy transfer processes and different stabilities of the chromophores. Reported herein is a pure organic ratiometric hypoxia nanoprobe, assembled by a monochromophore, naphthalimide ureidopyrimidinone (BrNpA‐UPy), bridged by a bis‐UPy‐functionalized benzyl skeleton. The joint factors of quadruple hydrogen bonding, the rigid backbone of UPy, and bromine substitution of the naphthalimide derivative facilitate bright phosphorescence (ΦP=7.7 %, τP=3.2 ms) and fluorescence of the resultant nanoparticles (SNPs) at room temperature, which enable accurate, ratiometric, sensitive oxygen detection (Ksv=189.6 kPa−1) in aqueous solution as well as in living HeLa cells.
An organic hypoxia nanoprobe assembled by quadruple hydrogen bonds, shows efficient long‐lived phosphorescence (ΦP=7.7 %, τP=3.2 ms) and fluorescence from a monochromophore at room temperature and can be used for oxygen detection in water and living cells. This is the first example of ratiometric hypoxia sensing by supramolecular assemblies of an organic monochromophore.
Metabolomics offers a noninvasive methodology to identify metabolic markers for pathogenesis and diagnosis of diseases. This work aimed to characterize circulating metabolic signatures of benign ...thyroid nodule (BTN) and papillary thyroid carcinoma (PTC) via serum‐plasma matched metabolomics. A cohort of 1,540 serum‐plasma matched samples and 114 tissues were obtained from healthy volunteers, BTN and PTC patients enrolled from 6 independent centers. Untargeted metabolomics was determined by liquid chromatography‐quadrupole time‐of‐flight mass spectrometric and multivariate statistical analyses. The use of serum‐plasma matched samples afforded a broad‐scope detection of 1,570 metabolic features. Metabolic phenotypes revealed significant pattern differences for healthy versus BTN and healthy versus PTC. Perturbed metabolic pathways related mainly to amino acid and lipid metabolism. It is worth noting that, BTN and PTC showed no significant differences but rather overlap in circulating metabolic signatures, and this observation was replicated in all study centers. For differential diagnosis of healthy versus thyroid nodules (BTN + PTC), a panel of 6 metabolic markers, namely myo‐inositol, α‐N‐phenylacetyl‐L‐glutamine, proline betaine, L‐glutamic acid, LysoPC(18:0) and LysoPC(18:1) provided area under the curve of 97.68% in the discovery phase and predictive accuracies of 84.78–98.18% in the 4 validation centers. Taken together, serum‐plasma matched metabolomics showed significant differences in circulating metabolites for healthy versus nodules but not for BTN versus PTC. Our results highlight the true metabolic nature of thyroid nodules, and potentially decrease overtreatment that exposes patients to unnecessary risks.
What's new?
When thyroid nodules are classified “indeterminate,” is it better to wait and see, or take out the thyroid? Usually, doctors remove the thyroid, resulting in a lifetime of levothyroxine replacement, yet most often the nodules are not cancerous. Here, the authors investigated whether metabolic profile could give a more accurate prediction of whether a thyroid nodule is cancerous. They tested healthy patients, those with benign nodules, and those with papillary thyroid carcinoma. Healthy patients showed distinct differences from those with benign nodules and those with carcinomas, while significant overlap was observed between circulating metabolites from BTN and PTC patients.
A novel palladium‐catalyzed CO‐gas‐ and autoclave‐free protocol for the synthesis of 11H‐pyrido2,1‐bquinazolin‐11‐ones has been developed. Quinazolinones, which are omnipresent motif in many ...pharmaceuticals and agrochemicals, were prepared in good yields by CH bond activation and annulation using DMF as the CO surrogate. A 13CO‐labelled DMF control experiment demonstrated that CO gas was released from the carbonyl of DMF with acid as the promotor. The kinetic isotope effect (KIE) value indicated that the CH activation step may not be involved in the rate‐determining step. This methodology is operationally simple and showed a broad substrate scope with good to excellent yields.
When DMF meets TFA: A novel palladium‐catalyzed CO‐gas and autoclave‐free procedure for the synthesis of 11H‐pyrido2,1‐bquinazolin‐11‐one using DMF as a CO surrogate has been developed (see scheme). 13CO‐labelled DMF and control experiments demonstrate that CO gas could be released from easily available and cheap DMF with the aid of an acid. The kinetic isotope effect (KIE) value indicates that the CH activation step may not be involved in the rate‐determining step. The reaction conditions displayed good functional group tolerance, and the desired products were isolated in good yields.
We investigate a generalized framework to estimate a latent low-rank plus sparse tensor, where the low-rank tensor often captures the multi-way principal components and the sparse tensor accounts for ...potential model mis-specifications or heterogeneous signals that are unexplainable by the low-rank part. The framework flexibly covers both linear and generalized linear models, and can easily handle continuous or categorical variables. We propose a fast algorithm by integrating the Riemannian gradient descent and a novel gradient pruning procedure. Under suitable conditions, the algorithm converges linearly and can simultaneously estimate both the low-rank and sparse tensors. The statistical error bounds of final estimates are established in terms of the gradient of loss function. The error bounds are generally sharp under specific statistical models, for example, the sub-Gaussian robust PCA and Bernoulli tensor model. Moreover, our method achieves nontrivial error bounds for heavy-tailed tensor PCA whenever the noise has a finite
2
+
ε
moment. We apply our method to analyze the international trade flow dataset and the statistician hypergraph coauthorship network, both yielding new and interesting findings.
Supplementary materials
for this article are available online.
The emergence of radical chemistry has driven chemists to develop general and efficient radical reactions as well as to discover safe and cost‐effective radical sources. Among the various ...transformations, the radical‐involved alkylation reaction continues to blossom since the alkyl unit is ubiquitous in biological and pharmaceutical compounds. The utilization of aliphatic aldehydes as alkyl radical precursors via peroxides or oxygen‐initiated decarbonylation reactions has attracted great attention over the past decade due to their ready availability and the simple operation. Although examples of radical acylation reactions starting from aldehydes have been reviewed before, reviews on decarbonylative radical reactions of aliphatic aldehydes are scarce. In this review, we summarize recent significant advances in this rapidly growing area, mainly focusing on reaction design and reaction mechanisms.
Sustainable solutions on fabricating and using a face mask to block the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) spread during this coronavirus pandemic of 2019 (COVID‐19) are ...required as society is directed by the World Health Organization (WHO) toward wearing it, resulting in an increasingly huge demand with over 4 000 000 000 masks used per day globally. Herein, various new mask technologies and advanced materials are reviewed to deal with critical shortages, cross‐infection, and secondary transmission risk of masks. A number of countries have used cloth masks and 3D‐printed masks as substitutes, whose filtration efficiencies can be improved by using nanofibers or mixing other polymers into them. Since 2020, researchers continue to improve the performance of masks by adding various functionalities, for example using metal nanoparticles and herbal extracts to inactivate pathogens, using graphene to make masks photothermal and superhydrophobic, and using triboelectric nanogenerator (TENG) to prolong mask lifetime. The recent advances in material technology have led to the development of antimicrobial coatings, which are introduced in this review. When incorporated into masks, these advanced materials and technologies can aid in the prevention of secondary transmission of the virus.
Masks are critical during the coronavirus pandemic of 2019 (COVID‐19), and there is a huge demand for them globally. Many countries use cloth masks and 3D‐printed masks as substitutes, but the filtration efficiencies are unqualified. Herein, various new mask technologies and advanced materials, including metal nanoparticles, graphene, metal organic framework (MOF), and triboelectric nanogenerator (TENG) are reviewed, to deal with critical shortages, cross‐infection, and secondary transmission risk of masks.
Backgrounds
Two technologies, cardiac contractility modulation (CCM) and subcutaneous implantable cardioverter‐defibrillator (S‐ICD), can be successfully combined and applied to patients with ...advanced heart failure (HF) with reduced left ventricular ejection fraction (LVEF).
Case Report
We reported a case of a 51‐year‐old man with reduced ejection fraction (LVEF = 33%) and a narrow QRS complex who first underwent simultaneous implantation of CCM and S‐ICD.
Conclusion
Our case report aimed to reveal that the simultaneous implantation of CCM and S‐ICD could be successfully used in patients with advanced HF, which could significantly improve the clinical symptoms of such patients during one surgery.
The difference in the mechanical behaviors of dilute solid solutions, complex solid solutions and their corresponding strengthening mechanisms, is an evolving field of study. An understanding of the ...mechanisms and formulation of theories of strengthening in the complex atomic energy landscapes could eventually lead to a better understanding of the fundamental behavior of condensed matter itself. In this work we attempt to extract the effect of thermo–mechanical processing on the microstructure–mechanical property linkages of complex concentrated alloys (CCAs) by training machine learning (ML) models using processing information / parameters as features. The effect of processing on the phase morphology and the mechanical properties is studied. The stacking fault energy (SFE) predicted based on CCA composition is used as a benchmark to identify deformation mechanisms that are activated based on the arrangement of the component elements within the distorted CCA lattice. This work presents a novel method that attempts to establish ML based process–structure–property (PSP) linkages that could help capture higher order dependencies that may not be adequately captured by existing relations between mechanical properties, phase evolution, composition and processing information. An assortment of Bayesian–learning models are used to create a framework that captures the evolution of phases, their volume fractions, grain sizes and the corresponding change in mechanical properties of a diverse set of CCA compositions as they encounter various processing conditions. The evolution of the mechanical property with grain size is captured as Hall–Petch relations as an example of possible PSP linkage representations.
•Effect of thermo-mechanical processing on the microstructure-mechanical properties.•A hierarchical model for determining properties over multiple length scale.•Bayesian learning models for predicting phases and their volume fractions.•Hall-Petch relation is verified as an example of PSP linkage representations.
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