Transition‐metal phosphides (TMPs) have emerged as promising catalyst candidates for the hydrogen evolution reaction (HER). Although numerous methods have been investigated to obtain TMPs, most rely ...on traditional synthetic methods that produce materials that are inherently deficient with respect to electrical conductivity. An electrospinning‐based reduction approach is presented, which generates nickel phosphide nanoparticles in N‐doped porous carbon nanofibers (Ni2P@NPCNFs) in situ. Ni2P nanoparticles are protected from irreversible fusion and aggregation in subsequent high‐temperature pyrolysis. The resistivity of Ni2P@NPCNFs (5.34 Ω cm) is greatly decreased by 104 times compared to Ni2P (>104 Ω cm) because N‐doped carbon NFs are incorporated. As an electrocatalyst for HER, Ni2P@NPCNFs reveal remarkable performance compared to other previously reported catalysts in acidic media. Additionally, it offers excellent catalytic ability and durability in both neutral and basic media. Encouraged by the excellent electrocatalytic performance of Ni2P@NPCNFs, a series of pea‐like MxP@NPCNFs, including Fe2P@NPCNFs, Co2P@NPCNFs, and Cu3P@NPCNFs, were synthesized by the same method. Detailed characterization suggests that the newly developed method could render combinations of ultrafine metal phosphides with porous carbon accessible; thereby, extending opportunities in electrocatalytic applications.
Like peas in a pod: An electrospinning‐based reduction approach was used to embed metal phosphide nanoparticles in nitrogen‐doped porous carbon nanofibers (NPCNFs). A series of pea‐like MxP@NPCNFs structures were fabricated (MxP=Ni2P, Fe2P, Co2P, and Cu3P). Ni2P@NPCNFs is a highly active catalyst for the hydrogen evolution reaction at all pH values.
Due to the advantages of good scalability, flexibility, low cost, ease of processing, 3D‐stacking capability, and large capacity for data storage, polymer‐based resistive memories have been a ...promising alternative or supplementary devices to conventional inorganic semiconductor‐based memory technology, and attracted significant scientific interest as a new and promising research field. In this review, we first introduced the general characteristics of the device structures and fabrication, memory effects, switching mechanisms, and effects of electrodes on memory properties associated with polymer‐based resistive memory devices. Subsequently, the research progress concerning the use of single polymers or polymer composites as active materials for resistive memory devices has been summarized and discussed. In particular, we consider a rational approach to their design and discuss how to realize the excellent memory devices and understand the memory mechanisms. Finally, the current challenges and several possible future research directions in this field have also been discussed.
In this review we introduce the general characteristics of the device structures and fabrication, memory effects, and switching mechanisms of polymer‐based resistive memory devices. Subsequently, the research progress concerning the use of single polymers or polymer composites as active materials for resistive memory devices are summarized. Finally, current challenges and future research directions in this field are discussed.
Phosphorescent manganese(II) complexes are emerging as a new generation of phosphorescent materials showing great potentials in many applications, owing to their unique features including highly ...efficient phosphorescence, diverse structural/molecular design, and ease of synthesis, structural diversity, rich physical properties (e.g., triboluminescence, stimuli‐responsivity, etc.), high abundance, and low cost. The research on phosphorescent manganese(II) complexes is just in its infancy but rapidly flourishing indeed, and their potential applications are also emerging in many aspects. Herein, the recent progress on the molecular design of new manganese(II) complex‐based materials, mechanism of phosphorescence, photophysical properties, and their representative applications is highlighted, which covers topics such as: i) structural features and photophysics of phosphorescent manganese(II) complexes; ii) molecular design strategies of phosphorescent manganese(II) complexes (e.g., neutral complexes, ionic complexes, coordination polymers, and other types of complexes); and iii) their emerging applications in the fields of organic electroluminescence, information recording and security protection, temperature sensors. Finally, some perspectives together with future research focus of the field are described.
Compared with the noble metals, manganese has abundant reserves, is environmentally friendly, and inexpensive. Phosphorescent manganese(II) complexes are emerging as a new generation of phosphorescent materials with great potential in many application areas. An overview of the molecular design, synthesis, photophysics, and recent research progress on phosphorescent manganese(II) complexes and their emerging applications is provided.
The prognostic value of FoxP3(+) regulatory T cells (Tregs) in cancer remains controversial. We did a meta-analysis to assess the prognostic effect of FoxP3(+) Treg across different types of cancer ...and to investigate factors associated with variations in this effect. PubMed, Embase, Cochrane CENTRAL, and Scopus were searched to identify eligible studies. In total, we analyzed 76 articles encompassing 17 types of cancer, and including 15,512 cancer cases. The overall pooled analysis including all types of cancer suggested FoxP3(+)Tregs had a significant negative effect on overall survival (OS) (OR 1.46, P < 0.001), but the prognostic effect varied greatly according to tumor site. High FoxP3(+) Tregs infiltration was significantly associated with shorter OS in the majority of solid tumors studied, including cervical, renal, melanomas, and breast cancers, et al; whereas, FoxP3(+) Tregs were associated with improved survival in colorectal, head and neck, and oesophageal cancers. The stratified analysis suggested the molecular subtype and tumor stage significantly influenced the prognostic value of FoxP3(+) Tregs in certain types of cancer. In conclusion, our meta-analysis suggests that the prognostic role of FoxP3(+) Tregs was highly influenced by tumor site, and was also correlated with the molecular subtype and tumor stage.
Primary graft dysfunction (PGD) is the main cause of early morbidity and mortality after lung transplantation. Previous studies have yielded conflicting results for PGD risk factors. Herein, we ...carried out a systematic review and meta-analysis of published literature to identify recipient-related clinical risk factors associated with PGD development.
A systematic search of electronic databases (PubMed, Embase, Web of Science, Cochrane CENTRAL, and Scopus) for studies published from 1970 to 2013 was performed. Cohort, case-control, or cross-sectional studies that examined recipient-related risk factors of PGD were included. The odds ratios (ORs) or mean differences (MDs) were calculated using random-effects models.
Thirteen studies involving 10042 recipients met final inclusion criteria. From the pooled analyses, female gender (OR 1.38, 95% CI 1.09 to 1.75), African American (OR 1.82, 95%CI 1.36 to 2.45), idiopathic pulmonary fibrosis (IPF) (OR 1.78, 95% CI 1.49 to 2.13), sarcoidosis (OR 4.25, 95% CI 1.09 to 16.52), primary pulmonary hypertension (PPH) (OR 3.73, 95%CI 2.16 to 6.46), elevated BMI (BMI≥25 kg/m2) (OR 1.83, 95% CI 1.26 to 2.64), and use of cardiopulmonary bypass (CPB) (OR 2.29, 95%CI 1.43 to 3.65) were significantly associated with increased risk of PGD. Age, cystic fibrosis, secondary pulmonary hypertension (SPH), intra-operative inhaled nitric oxide (NO), or lung transplant type (single or bilateral) were not significantly associated with PGD development (all P>0.05). Moreover, a nearly 4 fold increased risk of short-term mortality was observed in patients with PGD (OR 3.95, 95% CI 2.80 to 5.57).
Our analysis identified several recipient related risk factors for development of PGD. The identification of higher-risk recipients and further research into the underlying mechanisms may lead to selective therapies aimed at reducing this reperfusion injury.
Highly efficient lepidine‐based phosphorescent iridium(III) complexes with pentane‐2,4‐dione or triazolpyridine as ancillary ligands have been designed and prepared by a newly developed facile ...synthetic route. Fluorine atoms and trifluoromethyl groups have been introduced into the different positions of ligand, and their influence on the photophysical properties of complexes has been investigated in detail. All the triazolpyridine‐based complexes display the blueshifted dual‐peak emission compared to the pentane‐2,4‐dione‐based ones with a broad single‐peak emission. The complexes show emission with broad full width at half maximum (FWHM) over 100 nm, and the emissions are ranges from greenish–yellow to orange region with the absolute quantum efficiency (ΦPL) of 0.21–0.92 in solution, i.e., ΦPL = 0.92 (18), which is the highest value among the reported neutral yellow iridium(III) complexes. Furthermore, high‐performance yellow and complementary‐color‐based white organic light‐emitting diodes (OLEDs) have been fabricated. The FWHMs of the yellow, greenish–yellow OLEDs are in the range of 94–102 nm, which are among the highest values of the reported yellow or greenish–yellow‐emitting devices without excimer emission. The maximum external quantum efficiency of monochrome OLEDs can reach 24.1%, which is also the highest value among the reported yellow or greenish–yellow devices. The color rendering indexes of blue and complementary yellow‐based white OLED is as high as 78.
Excellent fluorine‐containing lepidine‐based phosphorescent iridium(III) complexes with pentane‐2,4‐dione or triazolpyridine as ancillary ligands are designed and prepared by a facile synthetic route. These complexes exhibit greenish‐yellow to yellow emission with high phosphorescent quantum yields up to 0.92 and wide emission band with FWHM over 100 nm, which is used for fabricating highly efficient yellow and white organic light‐emitting diodes.
Magnesium (Mg) alloys, as the lightest metal engineering materials, have broad application prospects. However, the strength and ductility of traditional Mg alloys are still relativity low and ...difficult to improve simultaneously. Refining grain size via the deformation process based on the grain boundary strengthening and the transition of deformation mechanisms is one of the feasible strategies to prepare Mg alloys with high strength and high ductility. In this review, the effects of grain size on the strength and ductility of Mg alloys are summarized, and fine-grained Mg alloys with high strength and high ductility developed by various severe plastic deformation technologies and improved traditional deformation technologies are introduced. Although some achievements have been made, the effects of grain size on various Mg alloys are rarely discussed systematically and some key mechanisms are unclear or lack direct microscopic evidence. This review can be used as a reference for further development of high-performance fine-grained Mg alloys.
Owing to the extremely limited structural deformation caused by the introduction of guest ions that their rigid structure can sustain, crystalline materials typically fail owing to structural ...collapse when utilized as electrode materials. Amorphous materials, conversely, are more resistant to volume expansion during dynamic ion transport and can introduce a lot of defects as active sites. Here, The amorphous polyaniline-coated/intercalated V
O
·nH
O (PVOH) nanowires are prepared by in situ chemical oxidation combined with self-assembly strategy, which exhibited impressive electrochemical properties because of its short-range ordered crystal structure, oxygen vacancy/defect-rich, improved electronic channels, and ionic channels. Through in situ techniques, the energy storage mechanism of its Zn
/H
co-storage is investigated and elucidated. Additionally, this work provides new insights and perspectives for the investigation and application of amorphous cathodes for aqueous zinc ion batteries.
Exploring nonlinear optical (NLO) functional motifs (FM, the structural origin of NLO efficiency) is vital for the rational design of NLO materials. Normal spectrum techniques applied in studying ...photon exciting materials are invalid for NLO materials, in which electrons are not excited substantially but only distorted under laser. A general strategy of determining NLO FM is proposed by comparative studies of experimental electron density (ED) without and under the laser. The in situ experimental ED and wavefunction of typical NLO material LiB3O5 (LBO) under dark and 360 and 1064 nm lasers are investigated. Compared with the initial state under dark, the ED of B3O5− unit at functional states under laser irradiation exhibits remarkable changes of topological atomic and bond properties, confirming the NLO FM being B3O5−. The work extracts for the first time the FM of a NLO material experimentally and highlights the crucial role of in situ ED analysis in studying NLO mechanisms.
A general strategy of determining nonlinear optical (NLO) functional motif (FM) is proposed by comparative studies of experimental electron density (ED) without and under the laser. In situ ED analysis is firstly adopted for an NLO material with typical LiB3O5 as an example. The work extracts the FM of a NLO material experimentally and highlights the crucial role of in situ ED analysis in studying NLO mechanisms.
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