bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of co‐ligand on the biological properties of Schiff base metal complexes: Synthesis, characterization, cytotoxicity, and antimicrobial studies
Authors: Vijayan Thamilarasan , Kim Jinheung , Azam Mohammad , Al‐Resayes Saud I. , Stalin Antony , Kannan Balakrishnan Senthamarai , Jayamani Arumugam , Ayyakannu Arumugam , Nallathambi Sengottuvelan 
Published: December 2021

In this work, six new mixed ligand Schiff base metal complexes of [M2(L1)(X)2Cl4] type, (where, M = CoII, NiII, CuII, L1 = Schiff base ligand derived from 1‐pyrenecarboxaldehyde and 1,4‐bis[3‐aminopropyl]piperazine and X = pyrazine‐2‐carboxylic acid or 2,2′‐biimidazole) were synthesized and studied their biological activity and cytotoxicity. The synthesized Schiff base ligands, their metal complexes were characterized by Infrared, UV‐Visible spectroscopy, and elemental analysis. Density functional theory calculations were performed to examine the molecular geometry and frontier molecular orbital properties of complexes (1–6). The DNA binding ability of these complexes (1–6) was evaluated by in vitro spectroscopic (absorption and fluorescence) titrations, viscosity measurements, and in silica by molecular docking measurements. The results showed a good binding propensity with the binding constant from 2.65 × 104 to 3.38 × 105 M−1 in the order 6 > 5 > 4 > 3 > 2 > 1, respectively. All complexes exhibited a good binding affinity to BSA proteins with relatively higher binding constant values similar to the trend of DNA binding studies and where Cu (II) complexes have greater efficiency than Co (II) and Ni (II) complexes. The in vitro cytotoxic study of all the complexes was investigated in the cervical cancer (HeLa) cell line, which displayed IC50 values of 1.36–24.2 μM, signifying the potential of complexes for an operative anticancer drug. Metal complexes were also screened for antimicrobial properties, which showed virtuous inhibition than the free ligands.
Facile Azabenz‐Annulations through UV‐induced Photocyclization: A Promising Method for Perylenediimide‐Based Organic Semiconductors
Authors: Sun Hua , Mu Zifeng , Yang Canglei , Zhang Kai , Ji Xingyu , Zhang Tianshu , Ding Huanda , Wang Shifan , Dong Liming , Zhang Jing , Zhang Qichun 
Published: December 2021

AbstractThe derivatization of perylenediimides (PDIs) by bay decoration is essential for the development of PDI‐based semiconductors owing to their excellent photoelectric properties. Herein, four bis‐azabenz‐annulated PDIs (bis‐AzaBPDIs) are concisely synthesized in high yields through ultraviolet‐induced photocyclization, where the reaction processes including aldimine condensation, cyclization, and oxidative re‐aromatization are investigated. The optical characterizations and theoretical simulation reveal that the unique properties of the four bis‐AzaBPDIs are comparable to their parent PDI. Organic field effect transistors with compounds 2, 3, or 4 as active layers indicated that all compounds showed unipolar electron transport properties with the mobilities of 1.1×10−3, 5.8×10−4, and 8.5×10−6 cm2 V−1 s−1, respectively. These results suggest the great potential of bis‐AzaBPDIs as organic semiconductors. The easy preparation approach reported in this work would renew research interest in developing bis‐AzaBPDI‐based optoelectronic molecules.
Semen and serum platinum levels in cisplatin‐treated survivors of germ cell cancer
Authors: Malone Eoghan R. , Lewin Jeremy , Li Xuan , Zhang Wen‐Jiang , Lau Susan , Jarvi Keith , Hamilton Robert J. , Hansen Aaron R. , Chen Eric X. , Bedard Philippe L. 
Published: December 2021

AbstractBackgroundTesticular cancer survivors often have impaired gonadal function possibly related to chemotherapy. Platinum is a heavy metal that can be detected at low levels in serum many years after treatment, it is not known whether platinum also persists in semen and if platinum persistence in semen is associated with impaired fertility.MethodsAdult cisplatin‐treated testicular cancer survivors were enrolled. High‐Performance Liquid Chromatography‐tandem mass spectrometry was used to measure semen and serum platinum levels. Semen quality and DNA Fragmentation Index (DFI) were assessed.ResultsFrom 11/2017 to 12/2019, 38 patients (median age 32 years; range: 19–52) were enrolled. Median cumulative cisplatin dose was 301 mg/m2 (range: 274–404). Platinum levels were higher in semen than in blood (p = 0.03). Semen platinum levels were not significantly associated with time from last cisplatin dosing (r = −0.34; p = 0.09) nor cumulative dose (r = −0.10, p = 0.63). Sperm concentration was correlated with time from last cisplatin dosing (r = 0.58, p < 0.001) but not with semen platinum level (r = −0.15, p = 0.46). DFI was not significantly associated with time from last cisplatin dosing (r = 0.55, p = 0.08) or semen platinum level (r = −0.32, p = 0.33). In four patients with serial semen samples, platinum level decreased and sperm concentration and motility increased over time.ConclusionsPlatinum is detected in semen of testicular cancer survivors at higher levels than matched blood samples. These preliminary findings may have important implications for the reproductive health of survivors of advanced testicular cancer, further study is needed to assess the relationship between platinum persistence in semen and recovery of fertility postchemotherapy.
Why do cells need oxygen? Insights from mitochondrial composition and function
Authors: Manoj Kelath Murali , Gideon Daniel Andrew , Jaeken Laurent 
Published: December 2021

AbstractMitochondrial membrane‐embedded redox proteins are classically perceived as deterministic “electron transport chain” (ETC) arrays cum proton pumps; and oxygen is seen as an “immobile terminal electron acceptor.” This is untenable because: (1) there are little free protons to be pumped out of the matrix; (2) proton pumping would be highly endergonic; (3) ETC‐chemiosmosis‐rotary ATP synthesis proposal is “irreducibly complex”/”non‐evolvable” and does not fit with mitochondrial architecture or structural/distribution data of the concerned proteins/components; (4) a plethora of experimental observations do not conform to the postulates/requisites; for example, there is little evidence for viable proton‐pumps/pH‐gradient in mitochondria, trans‐membrane potential (TMP) is non‐fluctuating/non‐trappable, oxygen is seen to give copious “diffusible reactive (oxygen) species” (DRS/DROS) in milieu, etc. Quite contrarily, the newly proposed murburn model's tenets agree with known principles of energetics/kinetics, and builds on established structural data and reported observations. In this purview, oxygen is needed to make DRS, the principal component of mitochondrial function. Complex V and porins respectively serve as proton‐inlet and turgor‐based water‐exodus portals, thereby achieving organellar homeostasis. Complexes I to IV possess ADP‐binding sites and their redox‐centers react/interact with O2/DRS. At/around these complexes, DRS cross‐react or activate/oxidize ADP/Pi via fast thermogenic one‐electron reaction(s), condensing to form two‐electron stabilized products (H2O2/H2O/ATP). The varied architecture and distribution of components in mitochondria validate DRS as (i) the coupling agent of oxidative reactions and phosphorylations, and (ii) the primary reason for manifestation of TMP in steady‐state. Explorations along the new precepts stand to provide greater insights on mitochondrial function and pathophysiology.
Three‐Dimensional Electrodes for Oxygen Electrocatalysis
Authors: Xu Jinxiao , Ma Yingjun , Xuan Cuijuan , Ma Chuanli , Wang Jie 
Published: December 2021

AbstractRechargeable metal‐air batteries have drawn extensive attention because of their remarkably high theoretical energy output and the ultra‐stable voltage platform but are restricted by the sluggish kinetics of oxygen reduction/evolution reactions at the cathode. To resolve this issue, great efforts have been made in focusing the three‐dimensional (3D) electrodes, which can provide adequate hierarchical channels and ensure the gas penetration of the air electrodes. Therefore, it is necessary to give a timely updates of 3D electrodes. In this review, we present the fundamentals and recent progress of 3D electrodes in oxygen reduction/evolution reactions, mainly including the 3D electrode design, the electrocatalysis in oxygen reduction, oxygen evolution and the bi‐functional activity of the two reactions. Besides, metal‐air batteries facilitated with 3D electrodes are also fully discussed, including the mechanisms based on the aqueous and organic electrolytes. At the end, the existing challenges and perspectives of 3D electrodes are proposed for further development of the metal‐air batteries and auxiliary generative ideas for the renewable energy development.
Spin States, Bonding and Magnetism in Mixed‐Valence Iron(0)‐Iron(II) Complexes**
Authors: Kim Daniel , Wilson Daniel W. N. , Fataftah Majed S. , Mercado Brandon Q. , Holland Patrick L. 
Published: December 2021

Abstract“Xenophilic” complexes offer metal‐metal bonds between disparate metal sites, but the nature of the metal‐metal bonding is often unclear. Here, we describe two novel complexes with unsupported Fe−Fe bonds, LxFe−Fp (LX = β‐aldiminate or β‐diketiminate; Fp = Fe(CO)2Cp), that offer insight into Fe−Fe bonding. Mössbauer, magnetism, and DFT analysis indicate that the most accurate electronic structure description is LFeII←Fe0(CO)2Cp, in which the Fe(CO)2Cp is low‐spin iron(0) and acts as an X‐type ligand toward the high‐spin iron(II) of the LFe fragment. This largely electrostatic interaction has a bond order of only 0.5. The three‐coordinate high‐spin iron(II) site has large zero‐field splitting, and in addition its Mössbauer parameters can be used to rank the Fp− “metalloligand” as a donor; it is nearly as strong a donor as phosphides and alkyls.
Targeting the IspD Enzyme in the MEP Pathway: Identification of a Novel Fragment Class
Authors: Diamanti Eleonora , Hamed Mostafa M. , Lacour Antoine , Bravo Patricia , Illarionov Boris , Fischer Markus , Rottmann Matthias , Witschel Matthias , Hirsch Anna K. H. 
Published: December 2021

AbstractThe enzymes of the 2‐C‐methylerythritol‐d‐erythritol 4‐phosphate (MEP) pathway (MEP pathway or non‐mevalonate pathway) are responsible for the synthesis of universal precursors of the large and structurally diverse family of isoprenoids. This pathway is absent in humans, but present in many pathogenic organisms and plants, making it an attractive source of drug targets. Here, we present a high‐throughput screening approach that led to the discovery of a novel fragment hit active against the third enzyme of the MEP pathway, PfIspD. A systematic SAR investigation afforded a novel chemical structure with a balanced activity–stability profile (16). Using a homology model of PfIspD, we proposed a putative binding mode for our newly identified inhibitors that sets the stage for structure‐guided optimization.
Structural analysis of the microglia–interneuron interactions in the CA1 hippocampal area of the APP/PS1 mouse model of Alzheimer's disease
Authors: Gervais Étienne , Iloun Parisa , Martianova Ekaterina , Gonçalves Bessa Ana Claudia , Rivest Serge , Topolnik Lisa 
Published: December 2021

AbstractMicroglia can interact with glutamatergic neurons and, through control of synaptic elements, regulate their physiological function. Much less is known about the partnership between microglia and GABAergic inhibitory interneurons. Here, we compared the interactions between microglia and parvalbumin (PV+) and somatostatin (SOM+) expressing interneurons in the CA1 hippocampal area of APP/PS1 transgenic mice that mimic certain aspects of the Alzheimer's disease (AD). We first uncovered a high level of interactions between microglia and two types of interneurons, with 98% of SOM+ and 90% of PV+ cells receiving different types of putative microglial contacts. The latter included the microglia soma to the interneuron soma (SomaMG‐to‐SomaIN), the microglia process to the interneuron soma (ProcessMG‐to‐SomaIN) and the microglia process to the interneuron dendrite (ProcessMG‐to‐DendIN) interactions. Moreover, we found significantly larger areas of interaction for the SomaMG‐to‐SomaIN and the ProcessMG‐to‐DendIN type of contacts between microglia and SOM+ cells. In contrast, PV+ cells exhibited larger areas for the ProcessMG‐to‐SomaIN interactions. Second, in APP/PS1 mice, although the overall microglia interactions with interneurons remained preserved, the fraction of interneurons receiving putative microglia contacts on their dendrites was reduced, and larger areas of interactions were observed for somatic contacts, suggesting a stronger modulation of the interneuron output by microglia in AD. In summary, these results reveal microglia as important partners of hippocampal PV+ and SOM+ GABAergic cells, with interneuron type‐specific pattern of interactions. Thus, microglia may play an essential role in the operation of interneurons under normal conditions and their dysfunction in disease.
Photocatalytic Activity of Radial Rutile Titanium(IV) Oxide Microspheres for Aerobic Oxidation of Organics
Authors: Kojima Ryota , Ohtani Bunsho , Tada Hiroaki 
Published: December 2021

AbstractRadial rutile TiO2 nanorod homomesocrystals (TiO2‐NR HOMCs) or the so‐called “sea urchin‐like TiO2 microspheres” were synthesized by using a hydrothermal method. TiO2‐NR HOMCs show photocatalytic activity for aerobic oxidative degradation of 2‐naphthol under irradiation of UV‐ and visible light. Furthermore, extremely small iron oxide clusters were formed on the surface of TiO2‐NR HOMCs (FeOx/TiO2‐NR HOMCs) by the chemisorption‐calcination technique to reduce the band gap. The FeOx‐surface modification gives rise to drastic enhancement of the UV‐ and visible‐light activity. Reversed double‐beam photoacoustic spectroscopy measurements were performed for TiO2‐NR HOMCs and FeOx/TiO2‐NR HOMCs to obtain the ERDT (energy‐resolved distribution of electron traps)/CBB (conduction‐band bottom) patterns. The ERDT/CBB pattern of TiO2‐NR HOMCs consists of two components derived from rutile (C1) and amorphous TiO2 (C2). In the pattern, the surface electron traps in C2 exist near the CBB to be removed by the FeOx‐surface modification. By taking this finding into consideration, the striking surface modification effect is ascribable to the electrocatalytic activity (or the action as an electron reservoir) of the FeOx clusters for multiple ORR, the suppression of recombination, and the increase in the visible‐light harvesting efficiency.
Structural Characterization of a New Collagen Biomimetic Octapeptide with Nanoscale Self‐Assembly Potential: Experimental and Theoretical Approaches
Authors: Mocanu Cosmin Stefan , Petre Brindusa Alina , Darie‐Ion Laura , Drochioiu Gabi , Niculaua Marius , Stoica Iuliana , Homocianu Mihaela , Nita Loredana Elena , Gradinaru Vasile Robert 
Published: December 2021

AbstractBioinspired peptides are attractive biomolecules which can improve our understanding of self‐assembly processes for rational design of new peptide‐based materials. Herein, a new amidated peptide FRSAPFIE (FRS), based on a sequence present in human collagen, was synthesized, characterized by mass spectrometry and subjected to self‐assembling investigations. The optimal conditions for self‐assembly were disclosed by dynamic light scattering at 32 °C and a peptide concentration of 0.51 %. In addition, AFM studies revealed ellipsoidal FRS shapes with an area between 0.8 and 3.1 μm2. The ability of self‐assembly was also proved using FAD dye as extrinsic fluorescence reporter. According to the theoretical analysis, the FRS peptide tends to form a bundle‐type association, with a type of fibrillary tangles particle. Altogether, our findings address new challenges regarding the FRS peptide which can be used in further self‐assembly studies to design biocompatible drug‐delivery platforms.
Isolation and Measurement of Respiration and Structural Studies of Purified Mitochondria from Heterotrophic Plant Tissues
Authors: Pandey Sonika , Kumari Aprajita , Singh Pooja , Gupta Kapuganti Jagadis 
Published: December 2021

AbstractMitochondria are the power houses of eukaryotic cells. These organelles contain various oxidoreductase complexes. Electron transfer from different reducing equivalents channeled via these complexes drives proton translocation across the inner mitochondrial membrane, leading to ATP generation. Plant mitochondria contain alternative NAD(P)H dehydrogenases, alternative oxidase, and uncoupling protein, and TCA cycle enzymes are located in their matrix. Apart from ATP production, mitochondria are also involved in synthesis of vitamins and cofactors and participate in fatty acid, nucleotide, photorespiratory, and antioxidant metabolism. Recent emerging evidence suggests that mitochondria play a role in redox signaling and generation of reactive oxygen and nitrogen species. For mitochondrial studies, it is essential to isolate physiologically active mitochondria with good structural integrity. In this article, we explain a detailed procedure for isolation of mitochondria from various heterotrophic tissues, such as germinating chickpea seeds, potato tubers, and cauliflower florets. This procedure requires discontinuous Percoll gradient centrifugation and can give a good yield of mitochondria, in the range of 4 to 8 mg per 50 g tissue with active respiratory capacity. After MitoTracker staining, isolated mitochondria can be visualized by using a confocal microscope. The structure of mitochondria can be monitored by scanning electron microscopy. © 2021 Wiley Periodicals LLC.Basic Protocol 1: Isolation of mitochondria from germinating chickpea seeds, potato tubers, and cauliflower floretsBasic Protocol 2: Quantification of mitochondrial protein concentration by Bradford assayBasic Protocol 3: Quantification of mitochondrial respiration using single‐channel free‐radical analyzerBasic Protocol 4: Staining of mitochondria and confocal imagingBasic Protocol 5: Visualization of isolated mitochondria under scanning electron microscope
Comparison of family selection methodologies used in the initial phase of sugarcane breeding
Authors: Ferreira Pedro Henrique Silva , Gonçalves Mateus Teles Vital , Teixeira Gabriely , Ferreira Matheus de Paula , de Oliveira Rebeca Lourenco , Barbosa Marcio Henrique Pereira , Peternelli Luiz Alexandre 
Published: December 2021

AbstractThe simplified system (SS) is a new method of selecting families in the first experimentation phase used in some sugarcane (Saccharum officinarum L.) breeding programs in Brazil. In the SS, clones are obtained from families whose genotypes are not individualized in the field. Such selected clones are used to compose the cloned family trial. In the conventional method (CM) of breeding, each genotype is individualized to form part of the family evaluation experiment. This work aimed to compare and verify if the SS provides genetic information at least similar to the CM. Two experiments were conducted, one for the CM and the other for the SS. Sixty full‐sib families were evaluated in each experiment. The characteristics evaluated were average stalk height, average stalk diameter, the content of total soluble solids (BRIX), the number of stalks per meter, average stalk mass, tonnes of stalks per hectare, and tonnes of BRIX per hectare. The mixed model methodology was used to estimate the genetic parameters and predict the families' genotypic values. Both methods enabled high precision in the evaluation of families and similar average genetic gains (10.1% for CM and 9.6% for SS). The SS makes it possible to select families with high genotypic value, high accuracy, and genetic gains comparable to the CM. Therefore, although the SS presents similar results as the CM, its simplicity and ease of being installed in the field in a smaller experimental area make it a promising methodology for selecting cloned families in a sugarcane breeding program.
Invasive predators affect community‐wide pollinator visitation
Authors: Liang Christina T. , Shiels Aaron B. , Haines William P. , Sandor Manette E. , Aslan Clare E. 
Published: December 2021

AbstractDisruption of plant–pollinator interactions by invasive predators is poorly understood but may pose a critical threat for native ecosystems. In a multiyear field experiment in Hawai'i, we suppressed abundances of globally invasive predators and then observed insect visitation to flowers of six native plant species. Three plant species are federally endangered (Haplostachys haplostachya, Silene lanceolata, Tetramolopium arenarium) and three are common throughout their range (Bidens menziesii, Dubautia linearis, Sida fallax). Insect visitors were primarily generalist pollinators, including taxa that occur worldwide such as solitary bees (e.g., Lasioglossum impavidum), social bees (e.g., Apis mellifera), and syrphid flies (e.g., Allograpta exotica). We found that suppressing invasive rats (Rattus rattus), mice (Mus musculus), ants (Linepithema humile, Tapinoma melanocephalum), and yellowjacket wasps (Vespula pensylvanica) had positive effects on pollinator visitation to plants in 16 of 19 significant predator–pollinator–plant interactions. We found only positive effects of suppressing rats and ants, and both positive and negative effects of suppressing mice and yellowjacket wasps, on the frequency of interactions between pollinators and plants. Model results predicted that predator eradication could increase the frequency of insect visitation to flowering species, in some cases by more than 90%. Previous results from the system showed that these flowering species produced significantly more seed when flowers were allowed to outcross than when flowers were bagged to exclude pollinators, indicating limited autogamy. Our findings highlight the potential benefits of suppression or eradication of invasive rodents, ants, and yellowjackets to reverse pollination disruption, particularly in locations with high numbers of at‐risk plant species or already imperiled pollinator populations.
Stable Isotope Trajectory Analysis (SITA): A new approach to quantify and visualize dynamics in stable isotope studies
Authors: Sturbois Anthony , Cucherousset Julien , De Cáceres Miquel , Desroy Nicolas , Riera Pascal , Carpentier Alexandre , Quillien Nolwenn , Grall Jacques , Espinasse Boris , Cherel Yves , Schaal Gauthier 
Published: December 2021

AbstractEcologists working with stable isotopes have to deal with complex datasets including temporal and spatial replication, which makes the analysis and the representation of patterns of change challenging, especially at high resolution. Due to the lack of a commonly accepted conceptual framework in stable isotope ecology, the analysis and the graphical representation of stable isotope spatial and temporal dynamics of stable isotope value at the organism or community scale remained in the past often descriptive and qualitative, impeding the quantitative detection of relevant functional patterns. The recent community trajectory analysis (CTA) framework provides more explicit perspectives for the analysis and the visualization of ecological trajectories. Building on CTA, we developed the Stable Isotope Trajectory Analysis (SITA) framework, to analyze the geometric properties of stable isotope trajectories on n‐dimensional (n ≥ 2) spaces of analysis defined analogously to the traditional multivariate spaces (Ω) used in community ecology. This approach provides new perspectives into the quantitative analysis of spatio‐temporal trajectories in stable isotope spaces (Ωδ) and derived structural and functional dynamics (Ωγ space). SITA allows the calculation of a set of trajectory metrics, based on either trajectory distances or directions, and new graphical representation solutions, both easily performable in an R environment. Here, we illustrate the use of our approach by reanalyzing previously published datasets from marine, terrestrial, and freshwater ecosystems. We highlight the insights provided by this new analytic framework at the individual, population, community, and ecosystems levels, and discuss applications, limitations, and development potential.