The effect of corticosteroids on clinical outcomes in patients with influenza pneumonia remains controversial. We aimed to further evaluate the influence of corticosteroids on mortality in adult ...patients with influenza pneumonia by comparing corticosteroid-treated and placebo-treated patients.
The PubMed, Embase, Medline, Cochrane Central Register of Controlled Trials (CENTRAL), and Information Sciences Institute (ISI) Web of Science databases were searched for all controlled studies that compared the effects of corticosteroids and placebo in adult patients with influenza pneumonia. The primary outcome was mortality, and the secondary outcomes were mechanical ventilation (MV) days, length of stay in the intensive care unit (ICU LOS), and the rate of secondary infection.
Ten trials involving 6548 patients were pooled in our final analysis. Significant heterogeneity was found in all outcome measures except for ICU LOS (I
= 38%, P = 0.21). Compared with placebo, corticosteroids were associated with higher mortality (risk ratio RR 1.75, 95% confidence interval CI 1.30 ~ 2.36, Z = 3.71, P = 0.0002), longer ICU LOS (mean difference MD 2.14, 95% CI 1.17 ~ 3.10, Z = 4.35, P < 0.0001), and a higher rate of secondary infection (RR 1.98, 95% CI 1.04 ~ 3.78, Z = 2.08, P = 0.04) but not MV days (MD 0.81, 95% CI - 1.23 ~ 2.84, Z = 0.78, P = 0.44) in patients with influenza pneumonia.
In patients with influenza pneumonia, corticosteroid use is associated with higher mortality.
PROSPERO (ID: CRD42018112384 ).
Electrocatalytic performance can be enhanced by engineering a purposely designed nanoheterojunction and fine‐tuning the interface electronic structure. Herein a new approach of developing atomic ...epitaxial in‐growth in Co‐Ni3N nanowires array is devised, where a nanoconfinement effect is reinforced at the interface. The Co‐Ni3N heterostructure array is formed by thermal annealing NiCo2O4 precursor nanowires under an optimized condition, during which the nanowire morphology is retained. The epitaxial in‐growth structure of Co‐Ni3N at nanometer scale facilitates the electron transfer between the two different domains at the epitaxial interface, leading to a significant enhancement in catalytic activities for both hydrogen and oxygen evolution reactions (10 and 16 times higher in the respective turn‐over frequency compared to Ni3N‐alone nanorods). The interface transfer effect is verified by electronic binding energy shift and density functional theory (DFT) calculations. This nanoconfinement effect occurring during in situ atomic epitaxial in‐growth of the two compatible materials shows an effective pathway toward high‐performance electrocatalysis and energy storages.
Co‐Ni3N nanorod arrays with an atomic epitaxial interface are synthesized, which exhibit significant enhancement in catalytic activities for both hydrogen and oxygen evolution reactions. A nanoconfinement effect is proposed to facilitate the interface charge transfer.
Catalyst‐controlled regiodivergent catalysis is a vital chemical tool that allows efficient access to large collections of structurally diverse molecules from a common precursor but remains a ...challenge. We report a catalyst‐controlled, tunable, and predictable regiodivergency in transforming the internal aliphatic propargyl esters into diverse libraries of highly substituted 1,3‐dienyl and allyl products by Pd‐catalysis. Depending on the ligand employed, the palladium catalyst can involve two typical approaches: electrophilic palladium catalysis and a sequential oxidative addition–reductive elimination pathway. This regiodivergent protocol endows facile access to four regioisomers with high regio‐ and stereoselectivity from the common propargyl esters. In terms of synthetic utility, a notable feature of this protocol is amenable to structural diversification of bioactive relevant molecules, enabling rapid assembly of many useful structural analogs of pharmaceutical candidates.
An unprecedented catalyst‐controlled regiodivergent strategy has been developed that allows efficient access to structurally diverse 1,3‐dienyl and allyl esters from common propargyl esters with high regio‐ and stereochemical outcomes. The ligand backbone is crucial for the regioselectivity pattern, enabling the palladium catalyst to involve electrophilic metal catalysis or sequential oxidative addition–reductive elimination pathway.
With the ever-growing need for lithium-ion batteries, particularly from the electric transportation industry, a large amount of lithium-ion batteries is bound to retire in the near future, thereby ...leading to serious disposal problems and detrimental impacts on environment and energy conservation. Currently, commercial lithium-ion batteries are composed of transition metal oxides or phosphates, aluminum, copper, graphite, organic electrolytes with harmful lithium salts, polymer separators, and plastic or metallic cases. The lack of proper disposal of spent lithium-ion batteries probably results in grave consequences, such as environmental pollution and waste of resources. Thus, recycling of spent lithium-ion batteries starts to receive attentions in recent years. However, owing to the pursuit of lithium-ion batteries with higher energy density, higher safety and more affordable price, the materials used in lithium-ion batteries are of a wide diversity and ever-evolving, consequently bringing difficulties to the recycling of spent lithium-ion batteries. To address this issue, both technological innovations and the participation of governments are required. This article provides a review of recent advances in recycling technologies of spent lithium-ion batteries, including the development of recycling processes, the products obtained from recycling, and the effects of recycling on environmental burdens. In addition, the remaining challenges and future perspectives are also highlighted.
Display omitted
•Advances in technologies for recycling spent LIBs are reviewed.•Characteristics and development of different recycling processes are discussed.•Products obtained from recycling of spent LIBs are summarized.•Effects of recycling spent LIBs on environmental burdens are presented.•Remaining challenges and future perspectives are highlighted.
Due to the relationship between structure and function in chemistry, access to novel chemical structures ultimately drives the discovery of novel chemical function. In this light, the formidable ...utility of the octahedral geometry of six‐coordinate metal complexes is founded in its stereochemical complexity combined with the ability to access chemical space that might be unavailable for purely organic compounds. In this Minireview we wish to draw attention to inert octahedral chiral‐at‐metal complexes as an emerging class of metal‐templated asymmetric “organocatalysts” which exploit the globular, rigid nature and stereochemical options of octahedral compounds and promise to provide new opportunities in the field of catalysis.
“Organocatalysis” with metal complexes: Inert octahedral metal complexes are an emerging class of catalysts for asymmetric synthesis. In these compounds the globular, rigid nature and stereochemical options of octahedral compounds are exploited. Complexes like those shown promise new opportunities in the field of catalysis.
As the best electrocatalysts for alcohol oxidation reactions in direct alcohol fuel cells (DAFCs), Pt‐based nanomaterials still face the challenges of low utilization efficiency of Pt atoms and poor ...reaction kinetics. To address these issues, a self‐etching strategy is developed to prepare PtBi nanorings (NRs) with abundant low‐coordinated atoms and inhomogeneous tensile strain (≈4%). The obtained PtBi NRs exhibit superior activity toward methanol oxidation reaction (MOR) and ethanol oxidation reaction (EOR) in alkaline media. Particularly, the mass activities of PtBi NRs for MOR and EOR are 9.4 and 8.5 times higher than those of commercial Pt/C, respectively, which are among the best in the reported Pt‐based catalysts. The highly open structure of PtBi NRs is believed to provide plentiful catalytic active sites and increase the utilization of Pt atoms. Theoretical calculations show that the two important factors, i.e., adsorption energy with the key reaction intermediates and the energy barrier for the potential‐determining step, are significantly optimized owing to the synergy of tensile strain and the ligand effect in PtBi NRs. This study offers a promising strategy for the rational design and preparation of highly efficient catalysts for DAFCs.
PtBi nanorings with abundant low‐coordinated atoms and inhomogeneous tensile strain (≈4%) are prepared based on a self‐etching strategy. The obtained PtBi nanorings exhibit outstanding electrocatalytic activity and stability toward methanol oxidation reaction and ethanol oxidation reaction in alkaline media.
Transition‐metal catalyzed intermolecular 1,2‐diarylation of electronically unactivated alkenes has emerged as an extensive research topic in organic synthesis. However, most examples are mainly ...limited to terminal alkenes. Furthermore, transition‐metal catalyzed asymmetric 1,2‐diarylation of unactivated alkenes still remains unsolved and is a formidable challenge. Herein, we describe a highly efficient directed nickel‐catalyzed reductive 1,2‐diarylation of unactivated internal alkenes with high diastereoselectivities. More importantly, our further effort towards enantioselective 1,2‐diarylation of the unactivated terminal and challenging internal alkenes is achieved, furnishing various polyarylalkanes featuring benzylic stereocenters in high yields and with good to high enantioselectivities and high diastereoselectivities. Interestingly, the generation of cationic Ni‐catalyst by adding alkali metal fluoride is the key to increased efficiency of this enantioselective reaction.
A highly diastereoselective Ni‐catalyzed reductive 1,2‐diarylation of unactivated internal alkenes was developed. Additionally, the enantioselective variant with unactivated terminal and challenging internal alkenes was also achieved, delivering various polyarylalkanes bearing benzylic stereocenters with good to high enantioselectivities and excellent diastereoselectivities.
Considering the synthetic value of introducing active alcoholic hydroxyl group, developing C-H functionalization of alcohols is of significance. Herein, we present a photochemical method that under ...visible light irradiation, selectfluor can effectively promote the oxidative cross-coupling between alcohols and heteroarenes without the external photocatalysis, achieving the selective α sp
C-H arylation of alcohol, even in the presence of ether. The N-F activation of selectfluor under blue LEDs irradiation is evidenced by electron paramagnetic resonance (EPR) study, which is the key process for the oxidative activation of α sp
C-H alcohols. The observed reactivity may have significant implications for chemical transformations.
A method for the construction of boron‐substituted quaternary carbons or diarylquaternary carbons by arylboration of highly substituted alkenylarenes is presented. A wide range of alkenes and ...arylbromides can participate in this reaction thus allowing for a diverse assortment of products to be prepared. In addition, a solvent dependent regiodivergent arylboration of 1,2‐disubstituted alkenylarenes is presented, thus greatly increasing the scope of products that can be accessed.
Boron‐substituted quaternary carbon or diarylquaternary carbon centers are constructed by arylboration of highly substituted alkenylarenes. A wide range of alkenes and arylbromides can participate in this reaction. In addition, a solvent dependent regiodivergent arylboration of 1,2‐disubstituted alkenylarenes is presented, thus greatly increasing the scope of products that can be accessed.
Two‐dimensional (2D) organic–inorganic hybrid perovskite nanosheets (NSs) are attracting increasing research interest due to their unique properties and promising applications. Here, for the first ...time, we report the facile synthesis of single‐ and few‐layer free‐standing phenylethylammonium lead halide perovskite NSs, that is, (PEA)2PbX4 (PEA=C8H9NH3, X=Cl, Br, I). Importantly, their lateral size can be tuned by changing solvents. Moreover, these ultrathin 2D perovskite NSs exhibit highly efficient and tunable photoluminescence, as well as superior stability. Our study provides a simple and general method for the controlled synthesis of 2D perovskite NSs, which may offer a new avenue for their fundamental studies and optoelectronic applications.
Ultrathin perovskite nanosheets: Single‐ and few‐layer free‐standing phenylethylammonium lead halide perovskite nanosheets with controlled lateral sizes were synthesized by a facile and fast crystallization method. These as‐prepared nanosheets show bright, tunable light emission (see picture) as well as enhanced stability.
PDF
