Small Warriors of Nature: Novel Red Emissive Chlorophyllin Carbon Dots Harnessing Fenton-Fueled Ferroptosis for In Vitro and In Vivo Cancer Treatment.

The appeal of carbon dots (CDs) has grown recently, due to their established biocompatibility, adjustable photoluminescence properties, and excellent water solubility. For the first time in the literature, copper chlorophyllin-based carbon dots (Chl-D CDs) are successfully synthesized. Chl-D CDs exhibit unique spectroscopic traits and are found to induce a Fenton-like reaction, augmenting photodynamic therapy (PDT) efficacies via ferroptotic and apoptotic pathways. To bolster the therapeutic impact of Chl-D CDs, a widely used cancer drug, temozolomide, is linked to their surface, yielding a synergistic effect with PDT and chemotherapy. Chl-D CDs' biocompatibility in immune cells and in vivo models showed great clinical potential.Proteomic analysis was conducted to understand Chl-D CDs' underlying cancer treatment mechanism. The study underscores the role of reactive oxygen species formation and pointed toward various oxidative stress modulators like aldolase A (ALDOA), aldolase C (ALDOC), aldehyde dehydrogenase 1B1 (ALDH1B1), transaldolase 1 (TALDO1), and transketolase (TKT), offering a deeper understanding of the Chl-D CDs' anticancer activity. Notably, the Chl-D CDs' capacity to trigger a Fenton-like reaction leads to enhanced PDT efficiencies through ferroptotic and apoptotic pathways. Hence, it is firmly believed that the inherent attributes of Chl-CDs can lead to a secure and efficient combined cancer therapy.

Click, Compute, Create: A Review of Web-based Tools for Enzyme Engineering.

Enzyme engineering, though pivotal across various biotechnological domains, is often plagued by its time-consuming and labor-intensive nature. This review aims to offer an overview of supportive in silico methodologies for this demanding endeavor. Starting from methods to predict protein structures, to classification of their activity and even the discovery of new enzymes we continue with describing tools used to increase thermostability and production yields of selected targets. Subsequently, we discuss computational methods to modulate both, the activity as well as selectivity of enzymes. Last, we present recent approaches based on cutting-edge machine learning methods to redesign enzymes. With exception of the last chapter, there is a strong focus on methods easily accessible via web-interfaces or simple Python-scripts, therefore readily useable for a diverse and broad community.

NBN- and BNB-Phenalenyls: the Yin and Yang of Heteroatom-doped π Systems.

NBN- and BNB-doped phenalenyls are isoelectronic to phenalenyl anions and cations, respectively. They represent a pair of complementary molecules that have essentially identical structures but opposite properties as electron donors and acceptors. The NBN-phenalenyls 1-4 considered here were prepared from N,N'-dimethyl-1,8-diaminonaphthalene and readily available boron-containing building blocks (i. e., BH3⋅SMe2 (1), p-CF3-C6H4B(OH)2 (2), C6H5B(OH)2 (3), or MesBCl2/iPr2NEt (4)). Treatment of 1 with 4-Me2N-2,6-Me2-C6H2Li gave the corresponding NBN derivative 5. The BNB-phenalenyl 6 was synthesized from 1,8-naphthalenediyl-bridged diborane(6), PhNH2, and MesMgBr. A computational study reveals that the photoemission of 1, 4, and 5 originates from locally excited (LE) states at the NBN-phenalenyl fragments, while that of 2 is dominated by charge transfer (CT) from the NBN-phenalenyl to the p-CF3-C6H4 fragment. Depending on the dihedral angle θ between its Ph and NBN planes, compound 3 emits mainly from a less polar LE (θ >55°) or more polar CT state (θ <55°). In turn, the energetic preference for either state is governed by the polarity of the solvent used. An equimolar aggregate of the NBN- and BNB-phenalenyls 3 and 6 (in THF/H2O) shows a distinct red-shifted emission compared to that of the individual components, which originates from an intermolecular CT state.

Förster resonance energy transfer within the neomycin aptamer.

Förster resonance energy transfer (FRET) measurements between two dyes is a powerful method to interrogate both structure and dynamics of biopolymers. The intensity of a fluorescence signal in a FRET measurement is dependent on both the distance and the relative orientation of the dyes. The latter can at the same time both complicate the analysis and give more detailed information. Here we present a detailed spectroscopic study of the energy transfer between the rigid FRET labels Çmf (donor) and tCnitro (quencher/acceptor) within the neomycin aptamer N1. The energy transfer originates from multiple emitting states of the donor and occurs on a low picosecond to nanosecond time-scale. To fully characterize the energy transfer, ultrafast transient absorption measurements were performed in conjunction with static fluorescence and time-correlated single photon counting (TCSPC) measurements, showing a clear distance dependence of both signal intensity and lifetime. Using a known NMR structure of the ligand-bound neomycin aptamer, the distance between the two labels was used to estimate κ2 and, therefore, make qualitative statements about the change in orientation after ligand binding with unprecedented temporal and spatial resolution. The advantages and potential applications of absorption-based methods using rigid labels for the characterization of FRET processes are discussed.

Heatwaves: does global research reflect the growing threat in the light of climate change?

BACKGROUND: With the increasing impacts of climate change, heatwaves are placing an enormous burden on health and social systems and threatening ecological diversity around the world. Heatwaves are increasing not only in frequency but also in severity and magnitude. They are causing the deaths of thousands of people. Research is needed on a multidisciplinary, supra-regional, and regional level. METHODS: A detailed evaluation of the research conducted is not yet available. Therefore, this study provides a detailed insight into the publication landscape to identify key players, incentives, and requirements for future scientific efforts that are useful not only for scientists but also to stakeholders and project funders. RESULTS: The number of publications on heatwaves is increasing, outpacing the trend of research indexed by the Science Citation Index Expanded. However, funding is lagging behind comparatively. Looking at absolute numbers, the USA, Australia, China, and some European countries have been identified as major players in heatwave research. If socio-economic numbers are included, Switzerland and Portugal lead the way. Australia and the UK dominate if the change in heatwave-exposed people is included. Nevertheless, exposure and economic strength of publishing countries were identified as the main drivers of national research interests. Previous heatwaves, in particular, have driven research efforts primarily at the national level. CONCLUSION: For an efficient monitoring or early detection system that also includes the economically weak regions, internationally networked efforts are necessary to enable preventive measures and damage limitation against heatwaves. Regardless of previous regional extreme heat events, research approaches should be focused to the global level.

Exploring Structure-Property Relations of B,S-Doped Polycyclic Aromatic Hydrocarbons through the Trinity of Synthesis, Spectroscopy, and Theory.

Polycyclic aromatic hydrocarbons (PAHs) are prominent lead structures for organic optoelectronic materials. This work describes the synthesis of three B,S-doped PAHs with heptacene-type scaffolds via nucleophilic aromatic substitution reactions between fluorinated arylborane precursors and 1,2-(Me3SiS)2C6H4/1,8-diazabicyclo[5.4.0]undec-7-ene (72-92% yield). All compounds contain tricoordinate B atoms at their 7,16-positions, kinetically protected by mesityl (Mes) substituents. PAHs 1/2 feature two/four S atoms at their 5,18-/5,9,14,18-positions; PAH 3 is a 6,8,15,17-tetrafluoro derivative of 2. For comparison, we also prepared the skewed naphtho[2,3-c]pentaphene-type isomer 4. The simultaneous presence of electron-accepting B atoms and electron-donating S atoms results in a redox-ambiphilic behavior; the radical cations [1•]+ and [2•]+ were characterized by electron paramagnetic resonance spectroscopy. Several low-lying charge-transfer states exist, some of which (especially S-to-B and Mes-to-B transitions) compete on the excited-state potential-energy surface. Consistent with the calculated state characters and oscillator strengths, this competition results in a spread of fluorescence quantum yields (2-27%). The optoelectronic properties of 1 change drastically upon addition of Ag+ ions: while the color of 1 in CH2Cl2 changes bathochromically from yellow to red (λmax from 463 to 486 nm; -0.13 eV), the emission band shifts hypsochromically from 606 to 545 nm (+0.23 eV), and the fluorescence quantum yield increases from 12 to 43%. According to titration experiments, higher order adducts [Agn1m]n+ are formed. As a suitable system for modeling Ag+ complexation, our calculations predict a dimer structure (n = m = 2) with Ag2S4 core, approximately linear S-Ag-S fragments, and Ag-Ag interaction. The computed optoelectronic properties of [Ag212]2+ agree well with the experimentally observed ones.

Kretek Cigarettes and Particulate Matter Emissions-An Aerosol Spectrometric Study on Typical Indonesian Brands Flavored With Cloves.

INTRODUCTION: In Indonesia, smoking is widespread. The same applies to second-hand smoke (SHS) exposure. More than 90% of Indonesian smokers smoke clove cigarettes, so-called Kreteks. They often contain more tar and nicotine than conventional cigarettes, but little is known about particulate matter (PM) emissions. In smokers' homes, SHS is the main source of PM that is hazardous to health. This study presents data of PM emissions from Kreteks. METHODS: SHS was generated in a closed 2.88 m³ measuring chamber. PM fractions (PM10, PM2.5, PM1) of three popular Kretek brands (two king-sized and one slim-sized) in comparison to conventional cigarettes and a reference cigarette were measured by laser aerosol spectroscopy in real-time. RESULTS: The king-sized Kreteks reached PM10 and PM2.5 mean concentrations of up to about 3000 µg/m³, and PM1 mean concentrations of up to about 2700 µg/m³. Consequently, these Kreteks emitted up to about 100% more PM10 and PM2.5, respectively 84% more PM1 than the reference cigarette, and up to about 260% more PM10 and PM2.5, respectively 234% more PM1 than the other investigated cigarettes. CONCLUSIONS: PM emissions from Kreteks can be very high. The Indonesian public should be informed and warned about it, considering the high prevalence of smoking and SHS exposure, in particular. The Indonesian tobacco control regulation is limited, and it is overdue to start with a serious and effective tobacco control policy. PM declaration to government authorities could be useful in smoking prevention and tobacco control. IMPLICATIONS: Research data are limited for Kretek cigarettes, including data on particulate matter (PM). The clove buds in Kretek cigarettes are for flavoring the smoke and shall soften the smoke feeling. That makes them very popular in Indonesia, in particular. The declaration of PM data of Kreteks and other tobacco products can play a key role in a more effective tobacco policy to reduce consumption of tobacco products, not only in Indonesia. To provide data on PM emissions, this study ascertained PM amounts in passive smoke from Indonesian Kreteks.

Neonicotinoids: A critical assessment of the global research landscape of the most extensively used insecticide.

The broad-spectrum insecticides in the neonicotinoid group are the most widely used worldwide because of their widely recognized advantages in the mode of action. Therefore, their use is growing on a large scale and, moreover, is often used preventively without considering the ecological impact. Studies demonstrated harmful effects on non-target organisms, which in turn negatively impact biodiversity and thus food production. The dramatic decline of honey bee colonies, for example, could be linked to the use of neonicotinoids. Ecologically sustainable solutions to this conflict must be focused by scientific research. The question arose whether the global research efforts meet these requirements on a global scale. Therefore, this review article aimed to analyze the global research landscape on neonicotinoids under ecological, economic, and temporal aspects. To this end, key players and incentives for investigations in this research field are identified. The increase in publications over time is significant and shows a dynamic citation pattern. It indicates a comparatively high interest in current research, with ecological issues becoming more and more the focus of international research. It has been shown that national publication performance and funding are in line with global market interests, with the most publishing country being China. In addition, the elevated status quo of the scientific infrastructure in high-economy countries and their willingness to support research can be linked to national research output. Lower economies are sparsely involved in published studies. The research performance accumulates with a high North-South divide. Therefore, future research projects must have a sustainable focus and take regional requirements worldwide into account. This requires greater involvement of developing countries as the most economically dependent regions with enormously increasing consumption rates. Solutions must be found to ensure sustainable food production against a backdrop of already declining biodiversity due to the large-scale use of neonicotinoids.

Does health-related poverty publication landscape reflect global needs in the light of the current poverty rebound?

BACKGROUND: After nearly a quarter-century of declining poverty, the numbers are rising again significantly. This is due not only to effects of climate change but also to the COVID-19 pandemics and armed conflict. Combined with the enormous health impacts, that will cause misery and health care costs worldwide. Therefore, this study provides background information on the global research landscape on poverty and health to help researchers, stakeholders, and policymakers determine the best way to address this threat. RESULTS: The USA is the key player, dealing mainly with domestic issues. European countries are also involved but tend to be more internationally oriented. Developing countries are underrepresented, with Nigeria standing out. A positive correlation was found between publication numbers and economic strength, while the relationship between article numbers and multidimensional poverty was negatively correlated. CONCLUSIONS: These findings highlight the need for advanced networking and the benefits of cross-disciplinary research to mitigate the coming impacts.

Environmental and health-related research on application and production of rare earth elements under scrutiny.

BACKGROUND: Unlike most other commodities, rare earth elements (REEs) are part of a wide range of applications needed for daily life all over the world. These applications range from cell phones to electric vehicles to wind turbines. They are often declared as part of "green technology" and, therefore, often called "green elements". However, their production and use are not only useful but also risky to the environment and human health, as many studies have shown. Consequently, the range of global research efforts is broad and highly variable, and therefore difficult to capture and assess. Hence, this study aims to assess the global parameters of global research on REE in the context of environment and health (REEeh). In addition to established bibliometric parameters, advanced analyses using market driver and scientific infrastructure values were carried out to provide deep insight into incentives, necessities, and barriers to international research. RESULTS: The focus of REE research is in line with national aspirations, especially from the major global players, China and the USA. Whereas globally, regional research interests are related to market interests, as evidenced by the inclusion of drivers such as electric vehicles, wind turbines, and permanent magnets. The topics receiving the most attention are related to gadolinium used for magnetic resonance imaging and the use of ceria nanoparticles. Since both are used for medical purposes, the medical research areas are equally profiled and mainly addressed in high-income countries. Nevertheless, environmental issues are increasingly in focus. CONCLUSIONS: There is still a need for research that is independent and open-ended. For this, market-independent technologies, substitutes and recycling of REEs need to be addressed scientifically. The results of this study are relevant for all stakeholders, from individual scientists to planners to funders, to improve future research strategies in line with these research mandates.

Temperature Dependence of the Krokinobacter rhodopsin 2 Kinetics.

We investigated the temperature-dependent kinetics of the light-driven Na+ pump Krokinobacter rhodopsin 2 (KR2) at Na+-pumping conditions. The recorded microsecond flash photolysis data were subjected to detailed global target analysis, employing Eyring constraints and spectral decomposition. The analysis resulted in the kinetic rates, the composition of the different photocycle equilibria, and the spectra of the involved photointermediates. Our results show that with the temperature increase (from 10 to 40°C), the overall photocycle duration is accelerated by a factor of 6, with the L-to-M transition exhibiting an impressive 40-fold increase. It follows from the analysis that in KR2 the chromophore and the protein scaffold are more kinetically decoupled than in other microbial rhodopsins. We link this effect to the rigidity of the retinal protein environment. This kinetic decoupling should be considered in future studies and could potentially be exploited for fine-tuning biotechnological applications.

Structure guided fluorescence labeling reveals a two-step binding mechanism of neomycin to its RNA aptamer.

The ability of the cytidine analog Çmf to act as a position specific reporter of RNA-dynamics was spectroscopically evaluated. Çmf-labeled single- and double-stranded RNAs differ in their fluorescence lifetimes, quantum yields and anisotropies. These observables were also influenced by the nucleobases flanking Çmf. This conformation and position specificity allowed to investigate the binding dynamics and mechanism of neomycin to its aptamer N1 by independently incorporating Çmf at four different positions within the aptamer. Remarkably fast binding kinetics of neomycin binding was observed with stopped-flow measurements, which could be satisfactorily explained with a two-step binding. Conformational selection was identified as the dominant mechanism.

The Pandemic Year 2020: World Map of Coronavirus Research.

BACKGROUND: SARS-CoV-2 is one of the most threatening pandemics in human history. As of the date of this analysis, it had claimed about 2 million lives worldwide, and the number is rising sharply. Governments, societies, and scientists are equally challenged under this burden. OBJECTIVE: This study aimed to map global coronavirus research in 2020 according to various influencing factors to highlight incentives or necessities for further research. METHODS: The application of established and advanced bibliometric methods combined with the visualization technique of density-equalizing mapping provided a global picture of incentives and efforts on coronavirus research in 2020. Countries' funding patterns and their epidemiological and socioeconomic characteristics as well as their publication performance data were included. RESULTS: Research output exploded in 2020 with momentum, including citation and networking parameters. China and the United States were the countries with the highest publication performance. Globally, however, publication output correlated significantly with COVID-19 cases. Research funding has also increased immensely. CONCLUSIONS: Nonetheless, the abrupt decline in publication efforts following previous coronavirus epidemics should demonstrate to global researchers that they should not lose interest even after containment, as the next epidemiological challenge is certain to come. Validated reporting worldwide and the inclusion of low-income countries are additionally important for a successful future research strategy.

Changes in Exosomal miRNA Composition in Thyroid Cancer Cells after Prolonged Exposure to Real Microgravity in Space.

As much as space travel and exploration have been a goal since humankind looked up to the stars, the challenges coming with it are manifold and difficult to overcome. Therefore, researching the changes the human organism undergoes following exposure to weightlessness, on a cellular or a physiological level, is imperative to reach the goal of exploring space and new planets. Building on the results of our CellBox-1 experiment, where thyroid cancer cells were flown to the International Space Station, we are now taking advantage of the newest technological opportunities to gain more insight into the changes in cell-cell communication of these cells. Analyzing the exosomal microRNA composition after several days of microgravity might elucidate some of the proteomic changes we have reported earlier. An array scan of a total of 754 miRNA targets revealed more than 100 differentially expressed miRNAs in our samples, many of which have been implicated in thyroid disease in other studies.

Changes in Exosome Release in Thyroid Cancer Cells after Prolonged Exposure to Real Microgravity in Space.

Space travel has always been the man's ultimate destination. With the ability of spaceflight though, came the realization that exposure to microgravity has lasting effects on the human body. To counteract these, many studies were and are undertaken, on multiple levels. Changes in cell growth, gene, and protein expression have been described in different models on Earth and in space. Extracellular vesicles, and in particular exosomes, are important cell-cell communicators, being secreted from almost all the cells and therefore, are a perfect target to further investigate the underlying reasons of the organism's adaptations to microgravity. Here, we studied supernatants harvested from the CellBox-1 experiment, which featured human thyroid cancer cells flown to the International Space Station during the SpaceX CRS-3 cargo mission. The initial results show differences in the number of secreted exosomes, as well as in the distribution of subpopulations in regards to their surface protein expression. Notably, alteration of their population regarding the tetraspanin surface expression was observed. This is a promising step into a new area of microgravity research and will potentially lead to the discovery of new biomarkers and pathways of cellular cross-talk.

A world map of esophagus cancer research: a critical accounting.

BACKGROUND: Esophageal cancer (EC) is one of the deadliest cancers worldwide. The contemporary strong increase of the adenocarcinomas in Western countries and the high mortality rates require the intensification of prospective multinational studies. METHODS: Therefore, this global health issue has been chosen for the bibliometric review of the global publication output. As source for meta and citation data, the Web of Science has been used and Density Equalizing Maps were applied for visualization. RESULTS: 17,387 articles on EC could be identified. The years with publication and citation maxima correspond to the appearance of the most prolific articles. China is the most publishing country, followed by Japan and the USA. Germany and the UK ranked 4th and 5th. The analysis of the ratios articles and socio-economic parameters emphasizes the leading position of the Scandinavian countries and Japan. Here, the high-income countries come out on top. The high incidence regions are mainly represented by Chinese and Japanese research. The association of the publication output and the overall research funding could be shown. CONCLUSIONS: A strengthened international network increasingly consisting of the scientifically best positioned countries as well as more of the high incidence countries worldwide is mandatory for future research. The findings deliver scientists, clinicians and decision makers backgrounds for future decisions all over the world.

Kocuria tytonis sp. nov., isolated from the uropygial gland of an American barn owl (Tyto furcata).

Avian uropygial glands have received increasing attention in recent years, but little is known about micro-organisms in uropygial glands. In this study, we isolated a strain of Gram-stain-positive, non-motile, non-spore-forming cocci, designated 442T, from the uropygial gland of an American barn owl (Tyto furcata) and characterized it using a polyphasic approach. 16S rRNA gene sequence analysis placed the isolate in the genus Kocuria. The G+C content was 70.8 mol%, the major menaquinone was MK-7(H2) and the predominant cellular fatty acids were anteiso-C15 : 0, anteiso-C17 : 0 and iso-C15 : 0. Phylogenetic analyses based on the 16S rRNA gene identified Kocuria rhizophila DSM 11926T (99.6 % similarity), Kocuria salsicia DSM 24776T (98.7 %), Kocuria varians DSM 20033T (98.3 %) and Kocuria marina DSM 16420T (98.3 %) as the most closely related species. However, average nucleotide identity values below 86 % indicated that the isolate differed from all species hitherto described. Chemotaxonomic analyses and whole-cell protein profiles corroborated these findings. Accordingly, the isolate is considered to be a member of a novel species, for which the name Kocuria tytonis sp. nov. is proposed. The type strain is 442T (=DSM 104130T=LMG 29944T).

Time-resolved IR spectroscopy reveals mechanistic details of ion transport in the sodium pump Krokinobacter eikastus rhodopsin 2.

We report a comparative study on the structural dynamics of the light-driven sodium pump Krokinobacter eikastus rhodopsin 2 wild type under sodium and proton pumping conditions by means of time-resolved IR spectroscopy. The kinetics of KR2 under sodium pumping conditions exhibits a sequential character, whereas the kinetics of KR2 under proton pumping conditions involves several equilibrium states. The sodium translocation itself is characterized by major conformational changes of the protein backbone, such as distortions of the α-helices and probably of the ECL1 domain, indicated by distinct marker bands in the amide I region. Carbonyl stretch modes of specific amino acid residues helped to elucidate structural changes in the retinal Schiff base moiety, including the protonation and deprotonation of D116, which is crucial for a deeper understanding of the mechanistic features in the photocycle of KR2.

Chlorophyll and Chlorophyll Derivatives Interfere with Multi-Drug Resistant Cancer Cells and Bacteria.

Multidrug resistance (MDR) causes challenging tasks in medicine. Human cancer cells, as well as microorganisms, can acquire multiresistance due to the up-regulation of efflux pumps (ABC transporters) and are difficult to treat. Here, we evaluated the effects of chlorophyll, the most abundant pigment on the globe, and its derivative, pheophytin, on cancer cells and methicillin-resistant Staphylococcus aureus (MRSA). We found that both substances have significant reversal effects on multidrug-resistant CEM/ADR5000 cells (RRpheophytin = 3.13, combination index (CI)pheophytin = 0.438; RRchlorophyll = 2.72, CIchlorophyll < 0.407), but not on drug-sensitive CCRF-CEM cells when used in combination with doxorubicin. This indicates that the porphyrins could interact with efflux pumps. Strong synergism was also observed in antimicrobial tests against MRSA when combining ethidium bromide with chlorophyll (FICI = 0.08). As there is a strong need for new drugs in order to reliably treat MDR cells, our research provides potential candidates for further investigation.

Bark Extract of the Amazonian Tree Endopleura uchi (Humiriaceae) Extends Lifespan and Enhances Stress Resistance in Caenorhabditis elegans.

Endopleura uchi (Huber) Cuatrec (Humiriaceae), known as uxi or uxi-amarelo in Brazil, is an endemic tree of the Amazon forest. In traditional medicine, its stem bark is used to treat a variety of health disorders, including cancer, diabetes, arthritis, uterine inflammation, and gynecological infections. According to HPLC analysis, the main constituent of the bark extract is the polyphenol bergenin. In the current study, we demonstrate by in vitro and in vivo experiments the antioxidant potential of a water extract from the stem bark of E. uchi. When tested in the model organism Caenorhabditis elegans, the extract enhanced stress resistance via the DAF-16/FOXO pathway. Additionally, the extract promoted an increase in the lifespan of the worms independent from caloric restriction. It also attenuated the age-related muscle function decline and formation of polyQ40 plaques, as a model for Huntington's disease. Thus, these data support anti-aging and anti-oxidant properties of E. uchi, which has not yet been described. More studies are needed to assess the real benefits of E. uchi bark for human health and its toxicological profile.