Beijing Administration Institute

In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.

capture as well as utilization were systematically discussed and compared. With our great effort, this review would be of significant importance for academic researchers for obtaining an overall understanding of the current developments and future trends of CCU. This work is bound to benefit researchers in fields relating to CCU and facilitate the progress of significant breakthroughs in both fundamental research and commercial applications to deliver perspective views for future scientific and industrial advances in CCU.

We review the uptake, translocation and transformation of metal based nanoparticles in higher plants, and present advanced analytical techniques and future perspectives in this field.

Nanostructured MoS₂ materials and their potential applications in energy conversion and storage devices.

δ-MnO₂was the best catalyst for catalytic oxidation of HCHO among four types of MnO₂catalyst.

Additive-free synthesis of ZIF-8 with perfect morphology in water at room temperature involves 3 key reactions and 5 evolutional steps.

In the past few decades, hundreds of materials have been tried as adjuvant; however, only aluminum-based adjuvants continue to be used widely in the world. Aluminum hydroxide, aluminum phosphate and alum constitute the main forms of aluminum used as adjuvants. Among these, aluminum hydroxide is the most commonly used chemical as adjuvant. In spite of its wide spread use, surprisingly, the mechanism of how aluminum hydroxide-based adjuvants exert their beneficial effects is still not fully understood. Current explanations for the mode of action of aluminum hydroxide-based adjuvants include, among others, the repository effect, pro-phagocytic effect, and activation of the pro-inflammatory NLRP3 pathway. These collectively galvanize innate as well as acquired immune responses and activate the complement system. Factors that have a profound influence on responses evoked by aluminum hydroxide-based adjuvant applications include adsorption rate, strength of the adsorption, size and uniformity of aluminum hydroxide particles, dosage of adjuvant, and the nature of antigens. Although vaccines containing aluminum hydroxide-based adjuvants are beneficial, sometimes they cause adverse reactions. Further, these vaccines cannot be stored frozen. Until recently, aluminum hydroxide-based adjuvants were known to preferentially prime Th2-type immune responses. However, results of more recent studies show that depending on the vaccination route, aluminum hydroxide-based adjuvants can enhance both Th1 as well as Th2 cellular responses. Advances in systems biology have opened up new avenues for studying mechanisms of aluminum hydroxide-based adjuvants. These will assist in scaling new frontiers in aluminum hydroxide-based adjuvant research that include improvement of formulations, use of nanoparticles of aluminum hydroxide and development of composite adjuvants.

Silver nanoparticles (AgNPs) are the nanomaterials most widely used as antimicrobial agents in a range of consumer products, due to the environmental release of either the AgNPs themselves or silver ions. Although AgNPs appear to be more potent than silver ions, the mechanism behind the activity is not fully elucidated yet. The most common mechanism of toxicity of AgNPs proposed to date is the release of silver ions and/or the particle-specific functions. In this study, Pseudomonas aeruginosa (a model for Gram-negative bacteria) was treated with AgNPs, and its proteomic response was comprehensively characterized to elucidate the antimicrobial mechanism of AgNPs in the microorganism. In total, 59 silver-regulated proteins (27 up-regulated and 32 down-regulated proteins) and 5 silver-binding proteins were identified. Bioinformatic analysis revealed that interference with the cell-membrane function and generation of intracellular reactive oxygen species (ROS) were the main pathways for the antibacterial effect. The pattern of membrane proteins regulated by AgNPs was similar to that found for silver ions. In addition, the same silver-binding proteins were obtained with both AgNPs and silver ions, which indicated that AgNPs probably affect the cell membrane and react with proteins by releasing silver ions. The elevation of intracellular ROS relative to that with silver ions confirmed oxidative damage caused by AgNPs, which may be ascribed to the nano-characteristics and higher uptake efficiency of the particles. These results demonstrate that the antimicrobial activity of AgNPs is due to the synergistic action of release of dissolved silver ions and particle-specific effects. The proteomic analysis of silver-binding and silver-regulated proteins in the present study provides insight into the mechanism of antimicrobial activity of such nanomaterials.

Alginate lyases catalyze the degradation of alginate, a complex copolymer of α-L-guluronate and its C5 epimer β-D-mannuronate. The enzymes have been isolated from various kinds of organisms with different substrate specificities, including algae, marine mollusks, marine and terrestrial bacteria, and some viruses and fungi. With the progress of structural biology, many kinds of alginate lyases of different polysaccharide lyases families have been characterized by obtaining crystal structures, and the catalytic mechanism has also been elucidated. Combined with various studies, we summarized the source, classification and properties of the alginate lyases from different polysaccharide lyases families. The relationship between substrate specificity and protein sequence was also investigated.

Selective catalytic reduction of NOx using NH3 or hydrocarbons (NH3-SCR or HC-SCR) in oxygen-rich exhaust from diesel engines remains a major challenge in environmental catalysis. The development of highly efficient, stable and environmentally-benign catalysts for SCR processes is very important for practical use. In this feature article, the structure-activity relationship of vanadium-free catalysts in the NH3-SCR reaction is discussed in detail, including Fe-, Ce-based oxide catalysts and Fe-, Cu-based zeolite catalysts, which is beneficial for catalyst redesign and activity improvement. Based on our research, a comprehensive mechanism contributing to the performance of Ag/Al2O3 in HC-SCR is provided, giving a clue to the design of a catalytic system with high efficiency.

Intestines are organs that not only digest food and absorb nutrients, but also provide a defense barrier against pathogens and noxious agents ingested. Tight junctions (TJs) are the most apical component of the junctional complex, providing one form of cell-cell adhesion in enterocytes and playing a critical role in regulating paracellular barrier permeability. Alteration of TJs leads to a number of pathophysiological diseases causing malabsorption of nutrition and intestinal structure disruption, which may even contribute to systemic organ failure. Claudins are the major structural and functional components of TJs with at least 24 members in mammals. Claudins have distinct charge-selectivity, either by tightening the paracellular pathway or functioning as paracellular channels, regulating ions and small molecules passing through the paracellular pathway. In this review, we have discussed the functions of claudin family members, their distribution and localization in the intestinal tract of mammals, their alterations in intestine-related diseases and chemicals/agents that regulate the expression and localization of claudins as well as the intestinal permeability, which provide a therapeutic view for treating intestinal diseases.

Engineered nanomaterials such as ZnO nanoparticles (NPs) will inevitably enter the environment because of the large quantities produced and their widespread application.

Graphene-based materials have shown great potential in various fields across physics, chemistry, biology, and electronics, due to their unique electronic properties, facile synthesis, and ease of functionalization.

Co-catalyst loading provides an effective way to enhance the efficiency of photocatalysts for solar hydrogen production. From a sustainability point of view, it has immense scientific and technological values to explore more efficient co-catalytic systems by using multi-cocatalysts, because of potential synergetic effects between different components. Herein, the feasibility of using Ti3C2 MXene nanoparticles and Pt nanoclusters as dual co-catalysts to enhance the photoactivity of g-C3N4 for H2 production was investigated. Due to the improved electrical conductivity and increased reactive sites for photoreduction reactions, Ti3C2 and Pt co-modified photocatalysts exhibited a high photocatalytic hydrogen production activity of 5.1 mmol h-1 g-1. Compared to g-C3N4/Ti3C2 and g-C3N4/Pt, the 3- and 5-fold increased photoactivity demonstrated great potential of Ti3C2 MXene nanoparticles to construct high-performance photocatalysts. The synergetic effects between Ti3C2 and Pt were fundamentally investigated, indicating that the specific transfer of electrons not only contributed to the inhibited recombination of charge carriers but also resulted in good stability of heterostructured photocatalysts. Our results have demonstrated an approach worthy for the design and fabrication of high-efficiency heterostructures with superior photoactivity for hydrogen energy production.

An ultrahigh arsenic uptake capacity was achieved using a hierarchically porous UiO-66 with tunable mesopores and active sites.

PURPOSE: Tau deposition is a key pathological feature of Alzheimer's disease (AD) and other neurodegenerative disorders. The spreading of tau neurofibrillary tangles across defined brain regions corresponds to the observed level of cognitive decline in AD. Positron-emission tomography (PET) has proved to be an important tool for the detection of amyloid-beta (Aβ) aggregates in the brain, and is currently being explored for detection of pathological misfolded tau in AD and other non-AD tauopathies. Several PET tracers targeting tau deposits have been discovered and tested in humans. Limitations have been reported, especially regarding their selectivity. METHODS: In our screening campaign we identified pyrrolo[2,3-b:4,5-c']dipyridine core structures with high affinity for aggregated tau. Further characterization showed that compounds containing this moiety had significantly reduced monoamine oxidase A (MAO-A) binding compared to pyrido[4,3-b]indole derivatives such as AV-1451. RESULTS: F]PI-2620 (compound 7) displayed high affinity for tau deposits in AD brain homogenate competition assays. Specific binding to pathological misfolded tau was further demonstrated by autoradiography on AD brain sections (Braak I-VI), Pick's disease and progressive supranuclear palsy (PSP) pathology, whereas no specific tracer binding was detected on brain slices from non-demented donors. In addition to its high affinity binding to tau aggregates, the compound showed excellent selectivity with no off-target binding to Aβ or MAO-A/B. Good brain uptake and fast washout were observed in healthy mice and non-human primates. CONCLUSIONS: F]PI-2620 was selected for clinical validation.

A novel 3D hybrid of layered MoS₂/nitrogen-doped graphene nanosheet aerogels exhibits significantly enhanced catalytic activity for bio-electrochemical hydrogen evolution.

Heterostructured composites with outstanding photocatalytic performance have attracted intense attention because of their great potential for use in environmental remediation.

The influence of environmental transformation on the toxicity of metal nanoparticles and possible mechanisms are recapitulated and discussed.

The recent discovery of ferromagnetic single-layer CrI₃ creates ample opportunities for studying the fundamental properties and the spintronic applications of atomically thin magnets.