In 1841, the extraction of hematoporphyrin from dried blood by removing iron marked the birth of the photosensitizer. The last twenty years has witnessed extensive research in the application of ...photodynamic therapy (PDT) in tumor-bearing (or other diseases) animal models and patients. The period has seen development of photosensitizers from the first to the third generation, and their evolution from simple to more complex entities. This review focuses on porphyrin photosensitizers and their effect on tumors, mediated via several pathways involved in cell necrosis, apoptosis or autophagic cell death, and the preventive and therapeutic application of PDT against atherosclerosis.
Most orogenic belts have experienced a complex accretionary process with multiple episodes of seafloor subduction and trench retreat. This accretionary process is important in continental development ...and growth .
Correntropy is a local similarity measure between two arbitrary variables, and it has been applied in a variety of learning algorithms to improve noise insensitivity. In this paper, based on the ...correntropy, a non-convex and bounded loss function is obtained which contains second and higher order moments of the classification margin. And the novel loss function is robust to noises and close to the 0–1 loss function. Then we introduce it into extreme learning machine (ELM), and propose a correntropy-based robust ELM framework for classification, trained by half quadratic optimization to cope with non-convexity of the algorithm. To evaluate robustness, feature noise and label noise are simulated to provide noisy environments. Experimental results on benchmark datasets demonstrate that the proposed algorithm is better than original algorithms and robust algorithms. Moreover, the superiority of proposed algorithm in noisy environment is more evident, which further proves its robustness to noises.
Oceanic plateaus with high-Mg rocks in the present-day oceanic crust have attracted much attention for their proposed mantle-plume origins and abnormally high mantle potential temperatures (Tp). ...However, equivalent rocks in ancient oceanic environments are usually poorly preserved because of deformation and metamorphism. Here we present petrological, geochronological and geochemical data for pillow lavas from Cambrian ophiolites in the Lajishan and Yongjing regions of the South Qilian Accretionary Belt (SQAB), from the southern part of the Qilian Orogen, northern China. Three rock groups can be identified geochemically: (1) sub-alkaline basalts with enriched mid- ocean ridge basalt (E-MORB) affinity; (2) alkaline basalts with oceanic island basalt (OIB) features, probably derived from partial melting of an enriched mantle source; and (3) picrites with MgO (18–22wt%). Cr-numbers Cr#=Cr/(Cr+Al) of spinels from the picrites suggest 18–21% degree of partial melting at the estimated mantle potential temperature (Tp) of 1489–1600°C, equivalent to values of Cenozoic Hawaiian picrites (1500–1600°C). Zircons from one gabbro sample yielded a U–Pb Concordia age of 525±3Ma, suggesting the oceanic crust formed in the Cambrian. Available evidence suggests that Cambrian mantle plume activity is preserved in the South Qilian Accretionary Belt, and influenced the regional tectonics: “jamming” of the trench by thick oceanic crust explains the emplacement and preservation of the oceanic plateau, and gave rise to the generation of concomitant Ordovician inner-oceanic island arc basalts via re-organisation of the subduction zones in the region.
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•We present plume-type ophiolites in an Early Paleozoic accretionary belt.•We confirm that they occurred as an oceanic plateau with a minimum age of 525Ma.•The rocks are mainly sub-alkaline, alkaline and picrites.•The subduction of oceanic plateau caused trench jam and continental accretion.
•An extremely rapid adsorption rate of arsenic on the sorbent was observed.•Higher affinity towards arsenic than most modified activated carbon sorbents.•The oxidation of As (III) occurred during the ...adsorption.•–OH group on the sorbent surface was involved in the adsorption via ligand exchange.
Co-existence of arsenate and arsenite in groundwater poses a great risk to humans. The objective of this study was to develop a cerium oxide modified activated carbon and to study its performance for removal of arsenic species. The adsorbent was prepared by a one-step solvothermal process. The FESEM-EDX analysis showed that the cerium oxide was mainly coated on the carbon surface. The thermal gravimetric analysis indicated the abundant presence of hydroxyl groups on the adsorbent. The point of zero charge was approximately 6.0. The uptake of arsenic species was highly affected by solution pH. The maximum adsorption capacities of As(V) and As(III) at pH 5 were 43.60 and 36.77mg-As/g, respectively. A rapid adsorption causing 90% of ultimate uptake in 30min was observed in the adsorption kinetics study, which outperformed other reported adsorbents; the better fitting of the experimental data was obtained by a pore diffusion model. The presence of phosphate exhibited the most significant interference on the adsorption. A limited interference was caused by the existence of humic acid, sulphate and carbonate, in particular at low concentration levels. Based on the results from the X-ray photoelectron spectroscopy analysis, nearly 90% of cerium element on the adsorbent was Ce(IV). The high redox potential of Ce(IV) was responsible for the partial oxidation of As(III) during the removal, which improved the As(III) uptake. The ligand exchange between hydroxyl groups on the adsorbent and arsenic species played a key role in the uptake of arsenic.
Cold stress limits plant geographical distribution and influences plant growth, development, and yields. Plants as sessile organisms have evolved complex biochemical and physiological mechanisms to ...adapt to cold stress. These mechanisms are regulated by a series of transcription factors and proteins for efficient cold stress acclimation. It has been established that the
signaling pathway in plants regulates how plants acclimatize to cold stress. Cold stress is perceived by receptor proteins, triggering signal transduction, and
(
) genes are activated and regulated, consequently upregulating the transcription and expression of the
(
) genes. The
protein binds to the
(
), a homeopathic element of the
genes (
gene) promoter, activating their transcription. Transcriptional regulations and post-translational modifications regulate and modify these entities at different response levels by altering their expression or activities in the signaling cascade. These activities then lead to efficient cold stress tolerance. This paper contains a concise summary of the
pathway elucidating on the cross interconnections with other repressors, inhibitors, and activators to induce cold stress acclimation in plants.
Silver ions in wastewater streams are a major pollutant and a threat to human health. Given the increasing demand and relative scarcity of silver, these streams could be a lucrative source to extract ...metallic silver. Wastewater is a complex mixture of many different metal salts, and developing recyclable sorbents with high specificity towards silver ions remains a major challenge. Here we report that molybdenum oxide (MoO
) adsorbent with mixed-valence (Mo(V) and Mo(VI)) demonstrates high selectivity (distribution coefficient of 6437.40 mL g
) for Ag
and an uptake capacity of 2605.91 mg g
. Our experimental results and density functional theory calculations illustrate the mechanism behind Ag
adsorption and reduction. Our results show that Mo(V) species reduce Ag
to metallic Ag, which decreases the energy barrier for subsequent Ag
reductions, accounting for the high uptake of Ag
from wastewater. Due to its high selectivity, MoO
favorably adsorbs Ag
even in the presence of interfering ions. High selective recovery of Ag
from wastewater (recovery efficiency = 97.9%) further supports the practical applications of the sorbent. Finally, MoO
can be recycled following silver recovery while maintaining a recovery efficiency of 97.1% after five cycles. The method is expected to provide a viable strategy to recover silver from wastewater.
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•Electrochemical technologies for heavy metal recovery are systematacially reviewed.•Four typical electrochemical recovery methods are classified for the first time.•Mechanisms of ...different electrochemical recovery technologies are fully discussed.•Influence factors of improving recovery efficiency for heavy metals are analyzed.•Electrochemical high value-added reutilization of heavy metal are prospected.
Wastewater treatment for heavy metals is currently transitioning from pollution remediation towards resource recovery. As a controllable and environment-friendly method, electrochemical technologies have recently gained significant attention. However, there is a lack of systematic and goal oriented summarize of electrochemical metal recovery techniques, which has inhibited the optimized application of these methods. This review aims at recent advances in electrochemical metal recovery techniques, by comparing different electrochemical recovery methods, attempts to target recycling heavy metal resources with minimize energy consumption, boost recovery efficiency and realize the commercial application. In this review, different electrochemical recovery methods (including E-adsorption recovery, E-oxidation recovery, E-reduction recovery, and E-precipitation recovery) for recovering heavy metals are introduced, followed an analysis of their corresponding mechanisms, influencing factors, and recovery efficiencies. In addition, the mass transfer efficiency can be promoted further through optimizing electrodes and reactors, and multiple technologies (photo-electrochemical and sono-electrochemical) could to be used synergistically improve recovery efficiencies. Finally, the most promising directions for electrochemical recovery of heavy metals are discussed along with the challenges and future opportunities of electrochemical technology in recycling heavy metals from wastewater.
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