Endo/lysosomal escape of gene vectors and the subsequent unpacking of nucleic acids in cytosol are two major challenges for efficient gene delivery. Herein, we report a polymeric gene delivery ...vector, which consists of a photosensitizer (PS) with aggregation‐induced emission (AIE) characteristics and oligoethylenimine (OEI) conjugated via an aminoacrylate (AA) linker that can be cleaved by reactive oxygen species (ROS). In aqueous media, the polymer could self‐assemble into bright red fluorescent nanoparticles (NPs), which can efficiently bind to DNA through electrostatic interaction for gene delivery. Upon visible light irradiation, the generated ROS can break the endo/lysosomal membrane and the polymer, resulting in light‐controlled endo/lysosomal escape and unpacking of DNA for efficient gene delivery. The smart polymer represents the first successful gene vector to simultaneously address both challenges with a single light excitation process.
Special delivery! A photoactive polymeric gene delivery vector can concurrently escape from the endo/lysosome and unpack nucleic acids in cytosol in a single light irradiation process. The polymer, which comprises a fluorogen with aggregation‐enhanced‐emission characteristics and a linker that can be cleaved by reactive oxygen species, forms nanoparticles that bind DNA and are endocytosed by cells.
Activatable photosensitizers (PSs) have been widely used for the simultaneous fluorescence imaging and photodynamic ablation of cancer cells. However, the ready aggregation of traditional PSs in ...aqueous media can lead to fluorescence quenching as well as reduced phototoxicity even in the activated form. We have developed a series of PSs that show aggregation‐enhanced emission and phototoxicity and thus the exact opposite behavior to that of previously reported PSs. We further developed a dual‐targeted enzyme‐activatable bioprobe based on the optimized photosensitizer and describe simultaneous light‐up fluorescence imaging and activated photodynamic therapy for specific cancer cells. The design of smart probes should thus open new opportunities for targeted and image‐guided photodynamic therapy.
Target and kill: A dual‐targeted enzyme‐activatable bioprobe based on a photosensitizer was developed with the characteristics of aggregation‐induced emission and aggregation‐enhanced phototoxicity (see picture; ROS=reactive oxygen species). The probe enables simultaneous light‐up fluorescence imaging and photodynamic ablation of specific cancer cells and shows a high signal‐to‐noise ratio without the need for a quencher or energy acceptor.
Aims
A meta‐analysis was conducted of the prevalence rates of compassion satisfaction, compassion fatigue and burnout to identify the factors influencing these rates.
Background
The extents of ...compassion fatigue and burnout adversely affect nursing efficiency. However, the reported prevalence rates vary considerably.
Methods
Data were acquired from electronic databases. Random effects meta‐analyses were performed to obtain pooled estimates of the prevalence rates of compassion satisfaction, compassion fatigue and burnout and their respective instrumental scores. Meta‐regression analyses were performed to identify factors influencing these rates.
Results
Data from 21 studies were used for the meta‐analysis. The prevalence rates of compassion satisfaction, compassion fatigue and burnout were 47.55%, 52.55% and 51.98%, respectively. The possession of Bachelor's or Master's degrees by the nurses was significantly inversely associated with the percent prevalence of compassion fatigue (coefficient: −1.187) and burnout (coefficient: −0.810). The compassion fatigue score was also significantly inversely associated with nursing status as registered or licensed practical nurse (coefficient: −0.135).
Conclusion
In nursing, the prevalence rates of compassion fatigue and burnout are high. Better education and training may have a moderating effect on compassion fatigue and burnout and could improve the quality of life of nurses.
Photodynamic therapy (PDT), which relies on photosensitizers (PS) and light to generate reactive oxygen species to kill cancer cells or bacteria, has attracted much attention in recent years. PSs ...with both bright emission and efficient singlet oxygen generation have also been used for image‐guided PDT. However, simultaneously achieving effective 1O2 generation, long wavelength absorption, and stable near‐infrared (NIR) emission with low dark toxicity in a single PS remains challenging. In addition, it is well known that when traditional PSs are made into nanoparticles, they encounter quenched fluorescence and reduced 1O2 production. In this contribution, these challenging issues have been successfully addressed through designing the first photostable photosensitizer with aggregation‐induced NIR emission and very effective 1O2 generation in aggregate state. The yielded nanoparticles show very effective 1O2 generation, bright NIR fluorescence centered at 820 nm, excellent photostability, good biocompatibility, and negligible dark in vivo toxicity. Both in vitro and in vivo experiments prove that the nanoparticles are excellent candidates for image‐guided photodynamic anticancer therapy.
An aggregation‐induced emission (AIE) photosensitizer with near‐infrared emission is synthesized via precise molecular design. The nanoparticles based on the AIE photosensitizer show effective singlet‐oxygen generation, near‐infrared fluorescence, excellent photostability, good biocompatibility, and negligible dark in vivo toxicity, which make them excellent candidates for image‐guided photodynamic anticancer therapy.
Liver fibrosis is a reversible wound-healing process aimed at maintaining organ integrity, and presents as the critical pre-stage of liver cirrhosis, which will eventually progress to hepatocellular ...carcinoma in the absence of liver transplantation. Fibrosis generally results from chronic hepatic injury caused by various factors, mainly viral infection, schistosomiasis, and alcoholism; however, the exact pathological mechanisms are still unknown. Although numerous drugs have been shown to have antifibrotic activity in vitro and in animal models, none of these drugs have been shown to be efficacious in the clinic. Importantly, hepatic stellate cells(HSCs) play a key role in the initiation, progression, and regression of liver fibrosis by secreting fibrogenic factors that encourage portal fibrocytes, fibroblasts, and bone marrow-derived myofibroblasts to produce collagen and thereby propagate fibrosis. These cells are subject to intricate cross-talk with adjacent cells, resulting in scarring and subsequent liver damage. Thus, an understanding of the molecular mechanisms of liver fibrosis and their relationships with HSCs is essential for the discovery of new therapeutic targets. This comprehensive review outlines the role of HSCs in liver fibrosis and details novel strategies to suppress HSC activity, thereby providing new insights into potential treatments for liver fibrosis.
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Film capacitors with high energy storage are becoming particularly important with the development of advanced electronic and electrical power systems. Polymer-based materials have ...stood out from other materials and have become the main dielectrics in film capacitors because of their flexibility, cost-effectiveness, and tailorable functional properties. A core issue for achieving films with high performance is to process a material with high dielectric permittivity and breakdown strength but low dielectric loss. Nanocomposites and all-polymer dielectrics are two promising avenues to address this issue. Thus, in this work, the advances of the past decade are highlighted to reflect the latest developments in polymer-based film dielectrics. The key factors of dielectric properties, including polarization mechanisms, dielectric breakdown strength, filler–matrix interface, and hierarchical structures are discussed in detail. A comprehensive understanding of the fabrication of polymer-based materials with special constituents, molecular segments, and microstructures will provide guidance to engineers on the fabrication of polymer-based materials with high performance.
The upland agricultural soils in North China are distributed north of a line between the Kunlun Mountains, the Qinling Mountains and the Huaihe River. They occur in arid, semi-arid and semi-humid ...regions and crop production often depends on rain-fed or irrigation to supplement rainfall. This paper summarizes the characteristics of gross nitrogen（N） transformation, the fate of N fertilizer and soil N as well as the N loss pathway, and makes suggestions for proper N management in the region. The soils of the region are characterized by strong N mineralization and nitrification, and weak immobilization and denitrification ability, which lead to the production and accumulation of nitrate in the soil profile. Large amounts of accumulated nitrate have been observed in the vadose-zone in soils due to excess N fertilization in the past three decades, and this nitrate is subject to occasional leaching which leads to groundwater nitrate contamination. Under farmer＇s conventional high N fertilization practice in the winter wheat-summer maize rotation system（N application rate was approximately 600 kg ha–1 yr–1）, crop N uptake, soil residual N, NH_3 volatilization, NO_3~– leaching, and denitrification loss accounted for around 27, 30, 23, 18 and 2% of the applied fertilizer N, respectively. NH_3 volatilization and NO_3~– leaching were the most important N loss pathways while soil residual N was an important fate of N fertilizer for replenishing soil N depletion from crop production. The upland agricultural soils in North China are a large source of N_2O and total emissions in this region make up a large proportion（approximately 54%） of Chinese cropland N_2O emissions. The “non-coupled strong ammonia oxidation” process is an important mechanism of N_2O production. Slowing down ammonia oxidation after ammonium-N fertilizer or urea application and avoiding transient high soil NH4＋ concentrations are key measures for reducing N_2O emissions in this region. Further N management should aim to minimize N losses from crop and livestock production, and increase the recycling of manure and straw back to cropland. We also recommend adoption of the 4 R（Right soure, Right rate, Right time, Right place） fertilization techniques to realize proper N fertilizer management, and improving application methods or modifying fertilizer types to reduce NH_3 volatilization, improving water management to reduce NO_3~– leaching, and controlling the strong ammonia oxidation process to abate N_2O emission. Future research should focus on the study of the trade-off effects among different N loss pathways under different N application methods or fertilizer products.
In numerous industrial applications where safety, efficiency, and reliability are among primary concerns, condition-based maintenance (CBM) is often the most effective and reliable maintenance ...policy. Prognostics, as one of the key enablers of CBM, involves the core task of estimating the remaining useful life (RUL) of the system. Neural networks-based approaches have produced promising results on RUL estimation, although their performances are influenced by handcrafted features and manually specified parameters. In this paper, we propose a multiobjective deep belief networks ensemble (MODBNE) method. MODBNE employs a multiobjective evolutionary algorithm integrated with the traditional DBN training technique to evolve multiple DBNs simultaneously subject to accuracy and diversity as two conflicting objectives. The eventually evolved DBNs are combined to establish an ensemble model used for RUL estimation, where combination weights are optimized via a single-objective differential evolution algorithm using a task-oriented objective function. We evaluate the proposed method on several prognostic benchmarking data sets and also compare it with some existing approaches. Experimental results demonstrate the superiority of our proposed method.
The real-time monitoring of reactive oxygen species (ROS, particularly singlet oxygen) generation during photodynamic therapy is a great challenge due to the extremely short half-life and small ...radius of action. To tackle this issue, we herein report a bioprobe composed of a red emissive photosensitizer (PS) with aggregation-induced emission (AIE) characteristics and a fluorogenic green emissive rhodol dye conjugated
a singlet oxygen cleavable aminoacrylate (AA) linker. The probe emits red fluorescence in water, and the red emissive PS can be used for probe self-tracking. Upon image-guided light irradiation, the generated singlet oxygen cleaves the AA linker to yield green fluorescence turn-on of rhodol, which offers real-time and
monitoring of singlet oxygen generation during photodynamic ablation of cancer cells, providing a strategy for the early evaluation of the therapeutic effect.
A targeted and image-guided platinum prodrug conjugated with a photosensitizer with aggregation-induced emission (AIE) characteristics was designed for real-time and in situ drug activation ...monitoring in cancer cells as well as combinational photodynamic-chemotherapy against cisplatin resistant cancer cells.
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