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The Middle Pleistocene archaeological record of the southern Levant has proven key to understanding human evolution and intercontinental faunal biogeography. Knowledge of archaeological sites of that period in the southern Levant is biased, with most Middle Pleistocene localities in the Mediterranean areas in the north, despite the mosaic of environments that mark the entire region. A key Middle Pleistocene location in the Judean Desert - on the eastern margin of the Mediterranean zone - is the site of Oumm Qatafa, excavated in the early 1900s, which yielded a faunal collection spanning an estimated time period of 600-200 kya. Here, we present a revised taxonomy of the macromammalian fauna from the site, discuss the palaeoenvironmental implications of this assemblage, and relate the finds to other Pleistocene sites from the Levant. These data enable a more precise palaeoenvironmental reconstruction which attests to an open landscape, but with the addition of a mesic Mediterranean component close by. In addition, detailed taphonomic observations on butchery marks and Fourier transform infrared spectroscopy analysis of burnt bone link the fauna for the first time to anthropogenic activities in the cave.

Deep learning is a powerful tool for exploring large datasets and discovering new patterns. This work presents an account of a metric learning-based deep convolutional neural network (CNN) applied to an archaeological dataset. The proposed account speaks of three stages: training, testing/validating, and community detection. Several thousand artefact images, ranging from the Lower Palaeolithic period (1.4 million years ago) to the Late Islamic period (fourteenth century AD), were used to train the model (i.e., the CNN), to discern artefacts by site and period. After training, it attained a comparable accuracy to archaeologists in various periods. In order to test the model, it was called to identify new query images according to similarities with known (training) images. Validation blinding experiments showed that while archaeologists performed as well as the model within their field of expertise, they fell behind concerning other periods. Lastly, a community detection algorithm based on the confusion matrix data was used to discern affiliations across sites. A case-study on Levantine Natufian artefacts demonstrated the algorithm’s capacity to discern meaningful connections. As such, the model has the potential to reveal yet unknown patterns in archaeological data.

Pyrotechnology is a key element of hominin evolution. The identification of fire in early hominin sites relies primarily on an initial visual assessment of artifacts’ physical alterations, resulting in potential underestimation of the prevalence of fire in the archaeological record. Here, we used a suite of spectroscopic techniques to counter the absence of visual signatures for fire and demonstrate the presence of burnt fauna and lithics at the Lower Paleolithic (LP) open-air site of Evron Quarry (Israel), dated between 1.0 and 0.8 Mya and roughly contemporaneous to Gesher Benot Ya’aqov where early pyrotechnology has been documented. We propose reexamining finds from other LP sites lacking visual clues of pyrotechnology to yield a renewed perspective on the origin, evolution, and spatiotemporal dispersal of the relationship between early hominin behavior and fire use.

Global warming has prompted a search for new materials that capture and sink carbon dioxide (CO2). Biochar is a derivative of biomass pyrolysis and a carbon sink mainly used to improve crop production. This work explores the underlying mechanism behind biochar's electric conductivity using a wide range of feedstocks and its combination with a binder (gypsum). This gypsum-biochar composite exhibits decreased density and flexural moduli with increasing biochar content, particularly after 20% w/w. Gypsum-biochar drywall-like composite prototypes display increasing shielding efficiency mostly in the microwave range as a function of biochar content, differing from other conventional metal (copper) and synthetic carbon-based materials. This narrow range of electromagnetic interference (EMI) shielding is attributed to natural alignment (isotropy) of the carbon ultrastructure (e.g., lignin) induced by heat and intrinsic interconnectivity in addition to traditional phenomena such as dissipation of surface currents and polarization in the electric field. These biomass-derived products could be used as sustainable lightweight materials in a future bio-based economy.

Production of stone artefacts using pyro-technology is known from the Middle and Upper Palaeolithic of Europe and the Levant, and the Middle Stone Age in Africa. However, determination of temperatures to which flint artefacts were exposed is impeded by the chemical and structural variability of flint. Here we combine Raman spectroscopy and machine learning to build temperature-estimation models to infer the degree of pyro-technological control effected by inhabitants of the late Lower Palaeolithic (Acheulo-Yabrudian) site of Qesem Cave, Israel. Temperature estimation shows that blades were heated at lower median temperatures (259 °C) compared to flakes (413 °C), whereas heat-induced structural flint damage (for example, pot-lids and microcracks) appears at 447 °C. These results are consistent with a differential behaviour for selective tool production that can be viewed as part of a plethora of innovative and adaptive behaviours of Levantine hominins >300,000 years ago. Controlled used of fire is one of the most outstanding achievements attributed to humankind. Artificial intelligence estimates the heating temperatures of flint tools fabricated by hominins over 300,000 years ago at Qesem Cave, providing insightful views into both advanced behaviours and the cognitive evolution of our species.

Herein appropriateness of nonfunctionalized mesoporous silica nanoparticles SBA-15 and functionalized with (3-chloropropyl)triethoxysilane (→ SBA-15~Cl) and (3-aminopropyl)triethoxysilane (→ SBA-15~NH2) on delivery of physically adsorbed Ph3Sn(CH2)6OH (Sn6) is evaluated. Fluorescent nanomaterial, bearing isatoic moiety, loaded with Sn6 (→ SBA-15~NF|Sn6) was used for cellular uptake study. The fluorescent nanomaterial is efficiently acquired and distributed into the cytoplasm of the cells even after 2 h of cultivation. According to the attained data, all SBA-15 materials loaded with Sn6 diminished cellular viability in dose dependent manner while carriers alone (SBA-15, SBA-15~Cl, SBA-15~NH2) did not show cytotoxicity against B16 cells. According to the MC50 values structural modification of SBA-15 did not improve the efficacy of tested drug. While progressive apoptosis was detected upon the treatment with SBA-15|Sn6, exposure of cells to SBA-15~NH2|Sn6 revealed extinguished apoptosis in time, accompanied with lower caspase activity. This effect is probably due to triggered autophagic process under the treatment with the SBA-15~NH2|Sn6, thus opposed to apoptosis. Presented results suggested that functionalization of SBA-15 was not beneficial for the efficacy of loaded drug, thus, all of them are almost equally efficient considering loaded Sn6 content. Importantly, functionalization of SBA-15 does have an influence on the mode of action and differentiation inducing properties.

Biomineralization is a common strategy adopted by organisms to support their body structure. Plants practice significant silicon and calcium based biomineralization in which silicon is deposited as silica in cell walls and intracellularly in various cell-types, while calcium is deposited mostly as calcium oxalate in vacuoles of specialized cells. In this review, we compare cellular processes leading to protein-dependent mineralization in plants, diatoms and sponges (phylum Porifera). The mechanisms of biomineralization in these organisms are inherently different. The composite silica structure in diatoms forms inside the cytoplasm in a membrane bound vesicle, which after maturation is exocytosed to the cell surface. In sponges, separate vesicles with the mineral precursor (silicic acid), an inorganic template, and organic molecules, fuse together and are extruded to the extracellular space. In plants, calcium oxalate mineral precipitates in vacuolar crystal chambers containing a protein matrix which is never exocytosed. Silica deposition in grass silica cells takes place outside the cell membrane when the cells secrete the mineralizing protein into the apoplasm rich with silicic acid (the mineral precursor molecules). Our review infers that the organism complexity and precursor reactivity (calcium and oxalate versus silicic acid) are main driving forces for the evolution of varied mineralization mechanisms.

Surface functionalized ZrO

Eocene flint 48–56.0 million years old (mya) from the Negev desert (Israel) was characterized using a suite of analytical techniques. High-resolution transmission electron microscopy (HR-TEM) and selected area electron diffraction (SAED) of the inorganic component showed the texture, morphology, size, and distribution of two silica polymorphs: α–quartz and moganite. While euhedral forms were attributed to α-quartz, moganite crystals were comprised of spherulitic grains. An electron less-dense amorphous material (no scattering under SAED) was found between the siliceous crystallites. Energy dispersive X-rays (EDS) and electron energy loss spectroscopy (EELS) demonstrated that this electron less-dense amorphous material is composed solely of carbon. Low vacuum, low energy backscattered environmental scanning electron microscopy (BSE-eSEM) imaging of flint surfaces showed the presence of micrometer-sized organic inclusions randomly distributed throughout the siliceous matrix. Energy-dispersive X-ray studies (EDS) demonstrated that these organic micro-inclusions were composed of carbon, sulfur, and nitrogen with a C/N ratio attributed to marine sources. These micro-inclusions were not directly associated with hard-shell fossils. BSE-eSEM imaging conditions allowed the identification of entrapped carbon-rich organic material, which is not possible when applying commonly used electron microscopy conditions that require carbon coating and high acceleration voltages, rendering carbon-rich features electron-transparent. Phase contrast-enhanced micro-computed tomography (PC-μCT) showed that these organic micro-inclusions were randomly distributed throughout the siliceous matrix. Time-of-flight secondary ion mass spectrometry (ToF-SIMS), nano-Fourier transform infrared spectroscopy (nano-FTIR), and scanning probe microscopy (SPM) were used to further characterize these organic micro-inclusions. These three in situ analytical techniques with nanometer resolution provided complementary information on the chemical composition and structure of the organic material. Specifically, ToF-SIMS analysis revealed amino acid and hydrocarbon mass spectra fingerprints inside the organic micro-inclusions. While the former were exclusively found in the organic micro-inclusions, the mass spectral fingerprints for hydrocarbons were also found in the siliceous matrix in agreement with the HR-TEM/EDS/EELS results, where pure carbon was found between the siliceous nanocrystals. While ToF-SIMS provides chemical information, it does not provide structural information. Nano-FTIR analysis showed the presence of amide I and II infrared vibrations exclusively on the organic micro-inclusions. The scanning probe microscopy (SPM) techniques Peak Force Quantitative Nanomechanics (PF-QNM) and Contact Resonance Atomic Force Microscopy (CR-AFM) were used to assess the mechanical properties. PF-QNM measurements on the organic micro-inclusions, under dry and liquid conditions, demonstrated that the organic micro-inclusions swell upon hydration and soften, pointing toward the presence of hydrophilic molecules in agreement with nano-FTIR and ToF-SIMS results. CR-AFM allows in situ determination of the mechanical properties of materials with high stiffness at nanometer resolution. This technique, rarely used in a geological context, revealed that the organic micro-inclusions had an unusually high stiffness atypical for modern organic material, which was attributed to molecular cross-linking promoted by diagenesis. This work provided a comprehensive view of the inorganic and organic components of Eocene flint from the Negev desert with implications for paleontology and archaeology. It offers a roadmap of novel complementary techniques that can be used in the exploration of entrapped organic material in flint.

Multicomponent nanostructures containing purely organic or inorganic as well as hybrid organic–inorganic components connected through a solid interface are, unlike conventional spherical particles, able to combine different or even incompatible properties within a single entity. They are multifunctional and resemble molecular amphiphiles, like surfactants or block copolymers, which makes them attractive for the self-assembly of complex structures, drug delivery, bioimaging, or catalysis. We have synthesized Pd@FexO heterodimer nanoparticles (NPs) to fabricate a macroporous, hydrophobic, magnetically active, three-dimensional (3D), and template-free hybrid foam capable of repeatedly separating oil contaminants from water. The Pd domains in the Pd@FexO heterodimers act as nanocatalysts for the hydrosilylation of polyhydrosiloxane and tetravinylsilane, while the FexO component confers magnetic properties to the final functional material. Pd@FexO heterodimers were synthesized by heterogeneous nucleation and g...

Cotton is the one of the world's most important crops. Like any other crop, cotton growth/development and fiber quality is highly dependent on environmental factors. Increasing global weather instability has been negatively impacting its economy. Cotton is a crop that exerts an intensive pressure over natural resources (land and water) and demands an overuse of pesticides. Thus, the search for alternative cotton culture methods that are pesticide-free (biocotton) and enable customized standard fiber quality should be encouraged. Here we describe a culture of Gossypium hirsutum ("Upland" Cotton) utilizing a greenhouse and hydroponics in which the fibers are morphological similar to conventional cultures and structurally fit into the classical two-phase cellulose I model with 4.19nm crystalline domains surrounded by amorphous regions. These fibers exhibit a single crystalline form of cellulose I-Iß, monoclinic unit cell. Fiber quality bulk analysis shows an improved length, strength, whiteness when compared with soil-based cultures. Finally, we show that our fibers can be spun, used for production of non-woven fabrics and indigo-vat stained demonstrating its potential in industrial and commercial applications.

Superoxide radicals are associated with the development of many severe diseases, such as cancer. Under nonpathogenic conditions, the natural enzyme superoxide dismutase (SOD) regulates the intracellular superoxide concentrations, but nearly all tumor tissues show reduced SOD levels. Selective imaging in early progression stages remains a key requirement for efficient cancer diagnosis and treatment. Magnetic resonance imaging (MRI) as a noninvasive tool with high spatial resolution may offer advantages here, but MRI contrast agents exhibiting a redox-triggered change in the image contrast towards superoxide radicals have not been reported so far. Here we show that manganese oxide (MnO) nanoparticles (NPs) exhibit an intrinsic SOD-like activity, which is higher than that of the native Mn-dependent SOD. In addition, MnO NPs significantly enhance the MRI contrast when exposed to superoxide radicals, making them responsive MRI contrast agents for the treatment and imaging of cancer cells with reduced SOD levels.

Pottery kilns are usually recognizable in the archaeological record based on their prominent and characteristic architectural features, evidence of exposure to high temperatures and associated waste products. Here we describe how we identified a kiln that has no readily recognizable architectural features, but does have an upper chamber full of broken pottery, and a lower chamber full of ash. The typology of the pottery in the upper chamber and radiocarbon dating show that the kiln was constructed after around 600 CE and was used until the early 7th century. The confining structures around these two chambers are sediments, some of which were deliberately brought to the site. A detailed study of the section through the kiln using on-site and off-site microarchaeological techniques revealed much about the firing conditions. The ash is composed almost entirely of phytoliths with a small amount of calcite. Surprisingly the diversity of phytolith morphotypes identified was low, and many of the phytoliths are unusually large multicells. The phytolith analysis shows that the fuel was mainly the stalks/chaff of domesticated grasses, most probably wheat, and probably not animal dung. Many of the phytolith morphologies are distorted and charred due to exposure to high temperatures, and show birefringence. Infrared spectra show that the phytoliths have partially recrystallized into the high temperature silicate mineral cristobalite. Slags formed close to the inner surfaces of the confining sediments presumably from melted phytoliths, and some of the clay-rich sediment close to these surfaces is clearly heat altered. These observations show that the temperatures in the firing chamber ranged from around 700 to 900 °C. The calcite in this ash is extremely disordered at the atomic level, based on the grinding curve analysis. A partial reconstruction of the kiln structure shows that the pottery chamber is above the firing chamber, and there is no constructed partition that separates the two chambers. The identification and characterization of this unusual kiln depended significantly on the use of the microarchaeological approach.

Herein appropriateness of nonfunctionalized mesoporous silica nanoparticles SBA-15 and functionalized with (3-chloropropyl)triethoxysilane (→ SBA-15~Cl) and (3-aminopropyl)triethoxysilane (→ SBA-15~NH

Cotton is the leading fiber source in the textile industry and one of the world’s most important crops. Despite its economic interest, cotton culture exerts an enormous pressure on natural resources (land and water) and has a negative impact on the environment (abuse of pesticides). Thus, alternative cotton growing methods are urged to be implemented. Recently, we have demonstrated that Gossypium hirsutum (“Upland” cotton) can be grown in a greenhouse (controlled conditions) and hydroponically. Here we report on the elucidation of the structural changes of the Gossypium hirsutum fibers during maturation grown [10, 14, 17, 20, 36 and 51 days post anthesis (dpa)] under a greenhouse and hydroponically, by means of scanning electron microscopy (SEM), Fourier transform infrared spectroscopy with attenuated total reflectance (FT-IR ATR) and thermal gravimetric analysis/differential scanning calorimetry (TGA/DSC). The transition from primary to secondary cell wall growth occurs between 17 and 20 dpa—similarly to the soil-based cultures. However, this new cotton culture offers an advantageous pesticide and soil-free all year-round closed system with efficient water use yielding standardized mature fibers with improved properties (maturity, strength, length, whiteness).

Surface functionalized ZrO2 nanoparticles show strong photoluminescence and are a versatile tool for cellular targeting due to their chemical functionality. They are highly photostable, biocompatible and amenable to coupling with bioligands (e.g. secondary goat anti-rabbit antibody (GAR) and tri-phenyl phosphine (TPP)) via carbodiimide chemistry. Antibody (GAR) functionalized ZrO2 nanoparticles were used to image the nuclear protein Sirt6, whereas triphenyl phosphonium ion (TPP) functionalized ZrO2 nanoparticles specifically targeted the mitochondria. The versatility and easiness of the ZrO2 surface modification opens up new possibilities for designing non-toxic water dispersible and photostable photoluminescent NPs.

In this paper, we apply a digital holographic microscope (DHM) in conjunction with stroboscopic acquisition synchronization. Here, the temperature-dependent decrease of the first resonance frequency (S1(T)) and Young’s elastic modulus (E1(T)) of silicon micromechanical cantilever sensors (MCSs) are measured. To perform these measurements, the MCSs are uniformly heated from T0 = 298 K to T = 450 K while being externally actuated with a piezo-actuator in a certain frequency range close to their first resonance frequencies. At each temperature, the DHM records the time-sequence of the 3D topographies for the given frequency range. Such holographic data allow for the extracting of the out-of-plane vibrations at any relevant area of the MCSs. Next, the Bode and Nyquist diagrams are used to determine the resonant frequencies with a precision of 0.1 Hz. Our results show that the decrease of resonance frequency is a direct consequence of the reduction of the silicon elastic modulus upon heating. The measured temperature dependence of the Young’s modulus is in very good accordance with the previously-reported values, validating the reliability and applicability of this method for micromechanical sensing applications.

Cotton is a promising basis for wearable smart textiles. Current approaches that rely on fiber coatings suffer from function loss during wear. We present an approach that allows biological incorporation of exogenous molecules into cotton fibers to tailor the material’s functionality. In vitro model cultures of upland cotton ( Gossypium hirsutum ) are incubated with 6-carboxyfluorescein–glucose and dysprosium–1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid–glucose, where the glucose moiety acts as a carrier capable of traveling from the vascular connection to the outermost cell layer of the ovule epidermis, becoming incorporated into the cellulose fibers. This yields fibers with unnatural properties such as fluorescence or magnetism. Combining biological systems with the appropriate molecular design offers numerous possibilities to grow functional composite materials and implements a material-farming concept.

Iron, as inorganic ion or as oxide, is widely used by biological systems in a myriad of biological functions (e.g., enzymatic, gene activation and/or regulation). In particular, marine organisms containing silica structures—diatoms and sponges—grow preferentially in the presence of iron. Using primary sponge cell culture from S. domuncula–primmorphs—as an in vitro model to study the Demospongiae spiculogenesis, we found the presence of agglomerates 50 nm in diameter exclusively inside sponge specialized cells called sclerocytes. A clear phase/material separation is observed between the agglomerates and the initial stages of intracellular spicule formation. STEM-HRTEM-EDX analysis of the agglomerates (30–100 nm) showed that they are composed of pseudohexagonal nanoparticles between 5 and 15 nm in size, displaying lattice parameters corresponding to hematite (Fe2O3) and mixed iron oxide phases typically attributed to ferritin. Further analysis, using western blotting, inductively coupled plasma mass spectrometry (ICP-MS), sequence alignment analysis, immunostaining and magnetic resonance imaging (MRI), of mature spicule filaments confirm the presence of ferritin within these organic structures. We suggest that S. domuncula can be classified as a dual biomineralizating organism, i.e., within the same cellular structure two distinct biomineralizing processes can occur as a result of the same cellular/metabolic function, spiculogenesis.

Sulfite oxidase is a mitochondria-located molybdenum-containing enzyme catalyzing the oxidation of sulfite to sulfate in the amino acid and lipid metabolism. Therefore, it plays a major role in detoxification processes, where defects in the enzyme cause a severe infant disease leading to early death with no efficient or cost-effective therapy in sight. Here we report that molybdenum trioxide (MoO3) nanoparticles display an intrinsic biomimetic sulfite oxidase activity under physiological conditions, and, functionalized with a customized bifunctional ligand containing dopamine as anchor group and triphenylphosphonium ion as targeting agent, they selectively target the mitochondria while being highly dispersible in aqueous solutions. Chemically induced sulfite oxidase knockdown cells treated with MoO3 nanoparticles recovered their sulfite oxidase activity in vitro, which makes MoO3 nanoparticles a potential therapeutic for sulfite oxidase deficiency and opens new avenues for cost-effective therapies for gene-induced deficiencies.

The skeletal system of Demospongiae consists of siliceous spicules, which are composed of an axial channel containing an organic axial filament (AF) surrounded by a compact layer of hydrated amorphous silica. Here we report the ultrastructural investigations of the AF of siliceous spicules from two Demospongiae: Suberites domuncula and Tethya aurantium . Electron microscopy, electron diffraction and elemental mapping analyses on both longitudinal and transversal cross-sections yield that spicules’s AF consist of a three-dimensional crystal lattice of six-fold symmetry. Its structure, which is the result of a biological growth process, is a crystalline assembly characterized by a lattice of organic cages (periodicity in the range of 6 nm) filled with enzymatically-produced silica. In general, the six-fold lattice symmetry is reflected by the morphology of the AF, which is characterized by six-fold facets. This seems to be the result of a lattice energy minimization process similar to the situation found during the growth of inorganic crystals. Our structural exploitation of three-dimensional organic lattices generated by biological systems is expected to contribute for explaining the relation between axial filament’s ultrastructure and spicule’s ultimate morphology.

Boron's unusual properties inspired major advances in chemistry. In Nature, the existence and importance of boron has been fairly explored (e.g. bacterial signaling, plant development) but its role as biological catalyst was never reported. Here, we show that boric acid [B(OH)3] can restore chloroperoxidase activity of Curvularia inaequalis recombinant apo-haloperoxidase's (HPO) in the presence of hydrogen peroxide and chloride ions. Molecular modeling and semi-empirical PM7 calculations support a thermodynamically highly favored (bio)catalytic mechanism similarly to vanadium haloperoxidases (V-HPO) in which [B(OH)3] is assumedly located in apo-HPO's active site and a monoperoxyborate [B(OH)3(OOH)-] intermediate is formed and stabilized by interaction with specific active site amino acids leading ultimately to the formation of HOCl. Thus, B(OH)3-HPO provides the first evidence towards the future exploitation of boron`s role in biological systems.

Micro/nano thermogravimetry (TG) employing MEMS has significant potential to improve the minimum sample mass and mass resolution as compared to commercial TG instruments. Although there have been a few previous reports on MEMS TG, none of them have critically analysed the obtained TG curve in detail. In this work, we have designed and fabricated a microelectromechanical thermogravimetric device (MMTG) with integrated microheaters and temperature sensors. The mass sensitivity of the device was estimated to be 0.89 pg/Hz which outperforms the standard TG approaches. We tested the MMTG performance with CuSO4.5H2O crystals. The final mass loss ratio corresponds to the theoretically expected value, although the obtained TG curve deviated from the standard TG curve of CuSO4.5H2O obtained from commercial TG instruments. We attributed the deviation to the inherent temperature non-uniformity, non-isothermal conditions and temperature gradients of metallic-wire based microheaters. Finite Element (FE) simulations were carried out in order to confirm and gain insights into the non-uniform heating phenomena of microheater and sample. Based on the simulation results, we propose designs that can be realized to make MEMS TG a successful enterprise.

The impressive mechanical properties of natural composites, such as nacre, arise from their multiscale hierarchical structures, which span from nano- to macroscale and lead to effective energy dissipation. While some synthetic bioinspired materials have achieved the toughness of natural nacre, current production methods are complex and typically involve toxic chemicals, extreme temperatures, and/or high pressures. Here, the exclusive use of bacteria to produce nacre-inspired layered calcium carbonate-polyglutamate composite materials that reach and exceed the toughness of natural nacre, while additionally exhibiting high extensibility and maintaining high stiffness, is introduced. The extensive diversity of bacterial metabolic abilities and the possibility of genetic engineering allows for the creation of a library of bacterially produced, cost-effective, and eco-friendly composite materials.

One endeavour of nanochemistry is the bottom-up synthesis of functional mesoscale structures from basic building blocks. We report a one-pot wet chemical synthesis of Ni@γ-Fe2O3 superparticles containing Ni cores densely covered with highly oriented γ-Fe2O3 (maghemite) nanorods (NRs) by controlled reduction/decomposition of nickel acetate (Ni(ac)2) and Fe(CO)5. Automated diffraction tomography (ADT) of the Ni-Fe2O3 interface in combination with Mossbauer spectroscopy showed that selective and oriented growth of the γ-Fe2O3 nanorods on the Ni core is facilitated through the formation of a Fe0.05Ni0.95 alloy and the appearance of superstructure features that may reduce strain at the Ni-Fe2O3 interface. The common orientation of the maghemite nanorods on the Ni core of the superparticles leads to a greatly enhanced magnetization. After functionalization with a catechol-functional polyethylene glycol (C-PEG) ligand the Ni@γ-Fe2O3 superparticles were dispersible in water.

6 páginas, 4 figuras., The complex process of supercontinuum generation (SG) is known to be exploitable for designing spatially coherent white light sources emitting light simultaneously in the ultraviolet, visible, and infrared ranges. Herein the first natural material able to generate in laboratory conditions a supercontinuum similar to those known from man-made photonic crystal fibers is described. The ability resides in siliceous 20–50 cm long spicules of the glass sponge Sericolophus hawaiicus. By shedding into the spicules optical peak intensities ranging from 1 to 100 TW cm−2 the generation of a SG is revealed. The SG involves wavelengths between 650 and 900 nm and shows a maximum spectral spread for excitation at a wavelength of 750 nm. It is hypothesized that the SG is favored by spicules being a biocomposite that incorporates together isotopically pure biogenic silica (δ30Si = −3.28) and 15.2 ± 1.3 μg N-acetyl-glucosamine (chitin) per mg of silica. The internal organization of these spicules is distinguished by a solid silica core with a 1 μm wide axial channel as well as a highly ordered silica–chitin composite. Such a composition and organization pattern may be of potential interest for the design of low temperature synthesis of future materials for light guidance., This work was partially supported by the following research grants DFG Grant EH 394/3-1, Krüger Research School, Biohydrometallurgical Center for Strategic Elements (BHMZ) at TU Bergakademie Freiberg, BMBF within the project CryPhys Concept (03EK3029A), Germany, and a grant of the Spanish Government (CTM2015-67221-R) to M.M.

Owing to their physical and chemical properties, inorganic functional materials have tremendous impacts on key technologies such as energy generation and storage, information, medicine, and automotive engineering. Nature, on the other hand, provides evolution-optimized processes, which lead to multifunctional inorganic–bio-organic materials with complex structures. Their formation occurs under physiological conditions, and is goverened by a combination of highly regulated biological processes and intrinsic chemical properties. Nevertheless, insights into the molecular mechanisms of biomineralization open up promising perspectives for bioinspired and biomimetic design and the development of inorganic–bio-organic multifunctional hybrids. Therefore, biomimetic approaches may disclose new synthetic routes under ambient conditions by integrating the concept of gene-regulated biomineralization principles. The skeletal structures of marine sponges provide an interesting example of biosilicification via enzymatically controlled and gene-regulated silica metabolism. Spicule formation is initiated intracellularly by a fine-tuned genetic mechanism, which involves silica deposition in vesicles (silicassomes) under the control of the enzyme silicatein, which has both catalytic and templating functions. In this review, we place an emphasis on the fabrication of biologically inspired materials with silicatein as a biocatalyst.

V2O5 nanowires exhibit an intrinsic catalytic activity towards classical peroxidase substrates such as 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 3,3,5,5,-tetramethylbenzdine (TMB) in the presence of H2O2. These V2O5 nanowires show an optimum reactivity at a pH of 4.0 and the catalytic activity is dependent on the concentration. The Michaelis-Menten kinetics of the ABTS oxidation over these nanowires reveals a behavior similar to that of their natural vanadium-dependent haloperoxidase (V-HPO) counterparts. The V2O5 nanowires mediate the oxidation of ABTS in the presence of H2O2 with a turnover frequency (k(cat)) of 2.5 x 10(3) s(-1). The K-M values of the V2O5 nanowires for ABTS oxidation (0.4 mu M) and for H2O2 (2.9 mu M) at a pH of 4.0 are significantly smaller than those reported for horseradish peroxidases (HRP) and V-HPO indicating a higher affinity of the substrates for the V2O5 nanowire surface. Based on the kinetic parameters and similarity with vanadium-based complexes a mechanism is proposed where an intermediate metastable peroxo complex is formed as the first catalytic step. The nanostructured vanadium-based material can be re-used up to 10 times and retains its catalytic activity in a wide range of organic solvents (up to 90%) making it a promising mimic of peroxidase catalysts.

The gold standard for bone reconstruction is the use of autogeneic grafts from various donor regions, since they possess osteoinductive as well as osteoconductive potential. Only a few synthetic materials possess/display properties that allow optimal bone reconstitution. Previously, we showed that the natural product, bio-silica, comprises osteoinductive, and probably also osteoconductive activity. Bio-silica is formed enzymatically via silicatein; this enzyme has been isolated from siliceous sponges and has also been cloned and prepared recombinantly. In the present study, silicatein was encapsulated together with its substrate, sodium metasilicate, in poly(D,L-lactide)/poly(vinyl pyrrolidone)-based microspheres, termed silicatein-and-silica-containing microspheres (SSMs). The deposition of silica and the kinetics of silicatein release from the microspheres are given. Furthermore, SSMs were successfully embedded in a poly(vinyl pyrrolidone)/starch-based matrix, termed plastic-like filler matrix containing silicic acid (PMSA). A blend of SSM and PMSA forms a biocompatible, moldable, and biodegradable functional implant material that hardens at a controlled and clinically suitable rate within approximately 30 min to 6 h to implants that were tightly integrated in artificial defects of rabbit femurs. Until now no toxic reactions caused by the silicatein have been observed in vitro or in vivo. We assume that the data given here contribute to a successful introduction of the silicatein/bio-silica-based implant materials to the field of regenerative medicine.

In j ngster Vergangenheit hat das Interesse f r die Entwicklung von Hybrid-Nanostrukturen, die sich aus verschiedenen Materialien zusammensetzen, in erheblichem Mase zugenommen. Es wurde berichtet, dass die Zusammenf hrung verschiedener Nanomaterialien, die ihrerseits spezifische optische, magnetische oder elektronische Eigenschaften aufweisen, zu Kompositen aus mehreren dieser Komponenten, deren individuelle Eigenschaften ver ndern oder sogar verbessern k nnen. Durch gezielte Optimierung der Struktur und der Grenzfl chenwechselwirkung innerhalb der Nanokomposite k nnte eine breite Basis f r zuk nftige Technologien geschaffen werden, beispielweise f r die synchrone Biomarkierung, Proteintrennung und -detektion, heterogene Katalyse und multimodale biomedizinische Bildgebung. Unter den verschiedenen Arten von Nanomaterialien spielen Goldnanost be wegen ihrer ausergew hnlich hohen Polarisierbarkeit im optischen Frequenzbereich, die von der Anregung lokalisierter Oberfl chenplasmonenresonanzen herr hrt, eine besondere Rolle. Zus tzlich weisen Goldnanost be vielversprechende therapeutische Eigenschaften als Hyperthermie-Wirkstoffe auf, da die Temperatur um die Nanost be rtlich durch die gezielte Anregung der Oberfl chenplasmonen nach Bestrahlung mit Infrarotlasern erh ht werden kann. Die Verwendung von Nahinfrarot-Strahlung bietet dar ber hinaus den Vorteil einer geringen Absorption und Streuung durch Blut und umgebendes Gewebe, was ein tieferes Eindringen der Strahlung in den K rper erm glicht. Magnetische Nanopartikel stellen eine weitere Klasse von Nanomaterialien dar, die in den vergangenen Jahren erhebliches Forschungsinteresse geweckt hat. Vor allem austauschgekoppelte magnetische Nanokomposite wie antiferromagnetische/ferromagnetische Kern-Schale-Nanopartikel (z.B. MnO/Mn3O4) weisen magnetische Eigenschaften auf, die sich von denen der einzelnen Komponenten stark unterscheiden. Im Bezug auf biomedizinische Anwendungen ist seit einigen Jahren bekannt, dass sich superparamagnetische Nanopartikel als Kontrastmittel f r die Magnetresonanztomographie (MRT) nutzen lassen. Die meisten Nanopartikel, die in diesem Kontext untersucht wurden, enthalten unterschiedliche Eisenoxide (Fe3O4, g-Fe2O3), welche die transversale (oder Spin-Spin-) Relaxationszeit T2 verk rzen. [11] Vor kurzem konnte dar ber hinaus gezeigt werden, dass Manganoxid(MnO)-Nanopartikel zu einer Verk rzung der longitudinalen (oder Spin-Gitter-) Relaxationszeit T1 f hren. Daher w re ein Nanopartikelsystem, das sowohl eine optisch adressierbare Au-Einheit als auch eine magnetisch aktive MnO-Komponente enth lt, f r eine simultane optische und MRT-Detektion besonders vorteilhaft. Obwohl in j ngster Zeit die Entwicklung geeigneter Oberfl chenliganden stark vorangetrieben wurde, ist die spezifische Adressierbarkeit der Oberfl che f r biologische Anwendungen noch immer ein groses Hindernis. Daher bietet ein Nanokomposit mit individuell ansprechbaren Auund MnO-Dom nen zwei verschiedene Oberfl chen f r die selektive Anbindung unterschiedlicher Molek le, was das Potenzial f r Diagnostik und Therapie wesentlich erh ht. Auserdem kann die Gr se der jeweiligen Komponente zur Optimierung der optischen und magnetischen Eigenschaften variiert werden. Hier berichten wir ber die Synthese von Au@MnO-Nanokompositen, die aus superparamagnetischen MnO-Nanopartikeln und Au-Kristalliten bestehen, sowie [*] T. D. Schladt, Dr. M. I. Shukoor, K. Schneider, Dr. M. N. Tahir, O. K hler, Prof. Dr. W. Tremel Institut f r Anorganische Chemie und Analytische Chemie Johannes Gutenberg-Universit t Duesbergweg 10-14, 55099 Mainz (Deutschland) Fax: (+49)6131-39-25605 E-Mail : tremel@uni-mainz.de

Here, design of the first pathogen-mimicking metal oxide nanoparticles with the ability to enter cancer cells and to selectively target and activate the TLR9 pathway, and with optical and MR imaging capabilities, is reported. The immobilization of ssDNA (CpG ODN 2006) on MnO nanoparticles is performed via the phosphoramidite route using a multifunctional polymer. The multifunctional polymer used for the nanoparticle surface modification not only affords a protective organic biocompatible shell but also provides an efficient and convenient means for loading immunostimulatory oligonucleotides. Since fluorescent molecules are amenable to photodetection, a chromophore (Rhodamine) is introduced into the polymer chain to trace the nanoparticles in Caki-1 (human kidney cancer) cells. The ssDNA coupled nanoparticles are used to target Toll-like receptors 9 (TLR9) receptors inside the cells and to activate the classical TLR cascade. The presence of TLR9 is demonstrated independently in the Caki-1 cell line by western blotting and immunostaining techniques. The magnetic properties of the MnO core make functionalized MnO nanoparticles potential diagnostic agents for magnetic resonance imaging (MRI) thereby enabling multimodal detection by a combination of MR and optical imaging methods. The trimodal nanoparticles allow the imaging of cellular trafficking by different means and simultaneously are an effective drug carrier system.

Ferromanganese [Fe/Mn] crusts formed on basaltic seamounts, gain considerable economic importance due to their high content of Co, Ni, Cu, Zn and Pt. The deposits are predominantly found in the Pacific Ocean in depths of over 1000 m. They are formed in the mixing layer between the upper oxygen-minimum zone and the lower oxygen-rich bottom zone. At present an almost exclusive abiogenic origin of crust formation is considered. We present evidence that the upper layers of the crusts from the Magellan Seamount cluster are very rich in coccoliths/coccolithophores (calcareous phytoplankton) belonging to different taxa. Rarely intact skeletons of these unicellular algae are found, while most of them are disintegrated into their composing prisms or crystals. Studies on the chemical composition of crust samples by high resolution SEM combined with an electron probe microanalyzer (EPMA) revealed that they are built of distinct stacked piles of individual compartments. In the center of such piles Mn is the dominant element, while the rims of the piles are rich in Fe ( mineralization aspect). The compartments contain coccospheres usually at the basal part. Energy dispersive X-ray spectroscopy (EDX) analyses showed that those coccospheres contain, as expected, CaCO3 but also Mn-oxide. Detailed analysis displayed on the surface of the coccolithophores a high level of CaCO3 while the concentration of Mn-oxide is relatively small. With increasing distance from the coccolithophores the concentration of Mn-oxide increases on the expense of residual CaCO3. We conclude that coccoliths/coccolithophores are crucial for the seed/nucleation phase of crust formation ( biomineralization aspect). Subsequently, after the biologically induced mineralization phase Mn-oxide deposition proceeds “auto”catalytically.

A chemically specific and facile method for the biofunctionalization of WS2 nanotubes (NT-WS2) is reported. The covalent modification strategy is based on the affinity of the nitrilotriacetic acid (NTA) side chain, which serves as a ligand for the surface binding to NT-WS2 and simultaneously as an anchor group for the binding of His-tagged proteins to the polymer backbone. The polymer functionalized WS2 nanotubes can be solubilized either in water or organic solvents; they are stable for at least one week. The probes were characterized by FT-IR and UV-vis spectroscopy. The immobilization of silicatein, a hydrolytic protein encountered in marine sponges, was visualized by scanning force microscopy (SFM) and confocal laser scanning microscopy (CLSM). The formation of the biotitania coating mediated by the immobilized silicatein onto the surface was characterized by scanning electron microscopy (SEM), and transmission electron microscopy (TEM).