Near-infrared microscopy reveals diabetic nephropathy in ob/ob mice.

Diabetic nephropathy (DN) is a major cause of global kidney failure. While histological kidney biopsy is the gold standard for diagnosis, it primarily reveals tissue morphology. In contrast, near-infrared (NIR) microscopy offers a label-free method for detailed molecular characterization of kidney tissue.

Fructosyl Amino Oxidase as a Therapeutic Enzyme in Age-Related Macular Degeneration.

Age-related macular degeneration (AMD) is an age-related disorder that is a global public health problem. The non-enzymatic Maillard reaction results in the formation of advanced glycation end products (AGEs). Accumulation of AGEs in drusen plays a key role in AMD.

Does dinocyst wall composition really reflect trophic affinity? New evidence from ATR micro-FTIR spectroscopy measurements.

Attenuated total reflection (ATR) microscope Fourier transform infrared (micro-FTIR) spectroscopy was used to investigate the dinosporin composition in the walls of modern, organic-walled dinoflagellate resting cysts (dinocysts). Variable cyst wall compositions were observed, which led to the erection of four spectrochemical groups, some with striking similarities to other resistant biomacromolecules such as sporopollenin and algaenan. Furthermore, possible proxies derivable from the spectrochemical composition of modern and fossil dinocysts were discussed.

Engineering of Phenylpyridine- and Bipyridine-Based Covalent Organic Frameworks for Photocatalytic Tandem Aerobic Oxidation/Povarov Cyclization.

Covalent organic frameworks (COFs) are emerging as a new class of photoactive organic semiconductors, which possess crystalline ordered structures and high surface areas. COFs can be tailor-made toward specific (photocatalytic) applications, and the size and position of their band gaps can be tuned by the choice of building blocks and linkages. However, many types of building blocks are still unexplored as photocatalytic moieties and the scope of reactions photocatalyzed by COFs remains quite limited.

Pyrene-Based Covalent Organic Frameworks for Photocatalytic Hydrogen Peroxide Production.

Four highly porous covalent organic frameworks (COFs) containing pyrene units were prepared and explored for photocatalytic H O production. The experimental studies are complemented by density functional theory calculations, proving that the pyrene unit is more active for H O production than the bipyridine and (diarylamino)benzene units reported previously. H O decomposition experiments verified that the distribution of pyrene units over a large surface area of COFs plays an important role in catalytic performance.

Attenuated Total Reflection (ATR) Micro-Fourier Transform Infrared (Micro-FT-IR) Spectroscopy to Enhance Repeatability and Reproducibility of Spectra Derived from Single Specimen Organic-Walled Dinoflagellate Cysts.

The chemical composition of recent and fossil organic-walled dinoflagellate cyst walls and its diversity is poorly understood and analyses on single microscopic specimens are rare. A series of infrared spectroscopic experiments resulted in the proposition of a standardized attenuated total reflection micro-Fourier transform infrared-based method that allows the collection of robust data sets consisting of spectra from individual dinocysts. These data sets are largely devoid of nonchemical artifacts inherent to other infrared spectrochemical methods, which have typically been used to study similar specimens in the past.

Identification of vanadium dopant sites in the metal-organic framework DUT-5(Al).

Studying the structural environment of the V ions doped in the metal-organic framework (MOF) DUT-5(Al) ((AlOH)BPDC) with electron paramagnetic resonance (EPR) reveals four different vanadium-related spectral components. The spin-Hamiltonian parameters are derived by analysis of X-, Q- and W-band powder EPR spectra. Complementary Q-band Electron Nuclear DOuble Resonance (ENDOR) experiments, Scanning Electron Microscopy (SEM), Energy Dispersive X-ray spectroscopy (EDX), X-Ray Diffraction (XRD) and Fourier Transform InfraRed (FTIR) measurements are performed to investigate the origin of these spectral components.

The biological plastic pump: Evidence from a local case study using blue mussel and infaunal benthic communities.

The distinct spatial variability in microplastic concentrations between marine regions and habitats calls for a better understanding about the transport pathways of this omnipresent pollutant in the marine environment. This study provides empirical evidence that a sessile filter feeder, the Blue mussel M. edulis, accelerates microplastic deposition by aggregating them into sinking particulate faeces and pseudofaeces.

Fructosamine-3-Kinase as a Potential Treatment Option for Age-Related Macular Degeneration.

Age-related macular degeneration is the leading cause of blindness in the developed world. Since advanced glycation end products (AGEs) are implicated in the pathogenesis of AMD through various lines of evidence, we investigated the potential of fructosamine-3-kinase (FN3K) in the disruption of retinal AGEs, drusenoid material and drusenoid lesions in patients with AMD. AGE-type autofluorescence was measured to evaluate the effects of FN3K on glycolaldehyde-induced AGE-modified neural porcine retinas and unmodified human neural retinas.

Metal-free activation of molecular oxygen by covalent triazine frameworks for selective aerobic oxidation.

Oxygen activation is a critical step in ubiquitous heterogeneous oxidative processes, most prominently in catalysis, electrolysis, and pharmaceutical applications. We present here our findings on metal-free O activation on covalent triazine frameworks (CTFs) as an important class of N-rich materials. The O activation process was studied for the formation of aldehydes, ketones and imines.

Do different habits affect microplastics contents in organisms? A trait-based analysis on salt marsh species.

Salt marshes in urban watersheds are prone to microplastics (MP) pollution due to their hydrological characteristics and exposure to urban runoff, but little is known about MP distributions in species from these habitats. In the current study, MP occurrence was determined in six benthic invertebrate species from salt marshes along the North Adriatic lagoons (Italy) and the Schelde estuary (Netherlands). The species represented different feeding modes and sediment localisation.

Mixed-metal metal-organic frameworks.

Mixed-metal MOFs are metal-organic frameworks that contain at least 2 different metal ions as nodes of their frameworks. They are prepared relatively easily by either a one-pot synthesis with a synthesis mixture containing the different metals, or by a post-synthetic ion-exchange method by soaking a monometallic MOF in a concentrated solution of a different (but compatible) metal-ion. More difficult is the accurate characterization of these materials.

The affiliation of Hexasterias problematica and Halodinium verrucatum sp. nov. to ciliate cysts based on molecular phylogeny and cyst wall composition.

Species in the genera Hexasterias and Halodinium have been recorded over the last decades as acritarchs in palynological and/or plankton studies. In paleoenvironmental studies, these resting stages are often interpreted as indicators of freshwater input. The biological affinity of these genera has never been definitely established.

Elucidating the Vibrational Fingerprint of the Flexible Metal-Organic Framework MIL-53(Al) Using a Combined Experimental/Computational Approach.

In this work, mid-infrared (mid-IR), far-IR, and Raman spectra are presented for the distinct (meta)stable phases of the flexible metal-organic framework MIL-53(Al). Static density functional theory (DFT) simulations are performed, allowing for the identification of all IR-active modes, which is unprecedented in the low-frequency region. A unique vibrational fingerprint is revealed, resulting from aluminum-oxide backbone stretching modes, which can be used to clearly distinguish the IR spectra of the closed- and large-pore phases.

ENDOR-Induced EPR of Disordered Systems: Application to X-Irradiated Alanine.

The electron paramagnetic resonance (EPR) spectra of radiation-induced radicals in organic solids are generally composed of multiple components that largely overlap due to their similar weak g anisotropy and a large number of hyperfine (HF) interactions. Such properties make these systems difficult to study using standard cw EPR spectroscopy even in single crystals. Electron-nuclear double-resonance (ENDOR) spectroscopy is a powerful and widely used complementary technique.

First record of resting cysts of the benthic dinoflagellate Prorocentrum leve in a natural reservoir in Gujan-Mestras, Gironde, France.

The resting cysts of the benthic dinoflagellate Prorocentrum leve from a natural reservoir in Gujan-Mestras (Gironde, France) were described in this study. The incubated urn-shaped cysts gave rise to cells of P. leve.

Sensing the framework state and guest molecules in MIL-53(Al) via the electron paramagnetic resonance spectrum of V dopant ions.

X-ray diffraction (XRD) and electron paramagnetic resonance spectroscopy (EPR) were combined to study the structural transformations induced by temperature, pressure and air humidity of the "breathing" metal-organic framework (MOF) MIL-53(Al), doped with paramagnetic V ions, after activation. The correlation between in situ XRD and thermogravimetric analysis measurements showed that upon heating this MOF in air, starting from ambient temperature and pressure, the narrow pore framework first dehydrates and after that makes the transition to a large pore state (lp). The EPR spectra of V[double bond, length as m-dash]O molecular ions, replacing Al-OH in the structure, also allow to distinguish the as synthesized, hydrated (np-h) and dehydrated narrow pore (np-d), and lp states of MIL-53(Al).

Microwave induced "egg yolk" structure in Cr/V-MIL-53.

Using a one pot microwave procedure, mixed-metal "egg yolk" MOFs are created, with a core of (Cr/V)-MIL-53 and a shell of Cr-MIL-53. In contrast, the solvothermal method produces homogeneous mixed-metal MOFs. The influence of Cr and V on the flexibility and breathing was studied via T-XRPD and CO adsorption measurements.

EPR and DFT analysis of biologically relevant chromium(V) complexes with d-glucitol and d-glucose.

1,2-diolato ligands, such as carbohydrates and glycoproteins, tend to stabilize chromium(V), thus forming important intermediates that have been implicated in the genotoxicity of Cr(VI). Since many years, room-temperature continuous-wave electron paramagnetic resonance (EPR) at X-band microwave frequencies has been used as a standard characterization tool to study chromium(V) intermediates formed during the reduction of Cr(VI) in the presence of biomolecules. In this work, the added value is tested of using a combination of pulsed and high-field EPR techniques with density functional theory computations to unravel the nature of Cr(V) complexes with biologically relevant chelators, such as carbohydrates.

Density and Capture Cross-Section of Interface Traps in GeSnO2 and GeO2 Grown on Heteroepitaxial GeSn.

An imperative factor in adapting GeSn as the channel material in CMOS technology, is the gate-oxide stack. The performance of GeSn transistors is degraded due to the high density of traps at the oxide-semiconductor interface. Several oxide-gate stacks have been pursued, and a midgap Dit obtained using the ac conductance method, is found in literature.

Fourth stable radical species in X-irradiated solid-state sucrose.

High-energy radiation produces radicals in crystalline sucrose. As such, sucrose is considered as a relevant model system for studying radiation damage to the sugar units of DNA. Many of these radicals are stable, detectable at room temperature with electron paramagnetic resonance (EPR) and their concentration is proportional to the absorbed dose in a considerable range.

Multi-frequency (S, X, Q and W-band) EPR and ENDOR Study of Vanadium(IV) Incorporation in the Aluminium Metal-Organic Framework MIL-53.

Doping the well-known metal-organic framework MIL-53(Al) with vanadium(IV) ions leads to significant changes in the breathing behaviour and might have repercussions on the catalytic behaviour as well. To understand the properties of such a doped framework, it is necessary to determine where dopant ions are actually incorporated. Electron paramagnetic resonance (EPR) and electron-nuclear double resonance (ENDOR) are applied to reveal the nearest environment of the paramagnetic vanadium(IV) dopant ions.

EMR Study and DFT-Assisted Identification of Transient Radicals in X-Irradiated Crystalline Sucrose.

Solid-state sucrose is a well-known dosimetric system, which is capable of reliable dose estimates only at a considerable time after exposure. Immediately after irradiation at room temperature, its electron paramagnetic resonance (EPR) spectrum is dominated by contributions from unstable radicals, which are studied here using continuous-wave EPR and electron-nuclear double resonance (ENDOR) spectroscopy. Four hyperfine tensors of proton couplings were determined, associated with two radical species, and subsequently compared to density functional theory calculation results, which led to the identification of the species with lower abundance (U2) as a radical formed by a H abstraction from C4.

Understanding the dosimetric powder EPR spectrum of sucrose by identification of the stable radiation-induced radicals.

Sucrose, the main component of table sugar, present in nearly every household and quite radiation sensitive, is considered as an interesting emergency dosemeter. Another application of radiation-induced radicals in sugars is the detection of irradiation in sugar-containing foodstuffs. The complexity of electron paramagnetic resonance (EPR) spectra of radicals in these materials, as a result of many hyperfine interactions and the multi-compositeness of the spectra of individual sugars, complicate dose assessment and the improvement of protocols for control and identification of irradiated sugar-containing foodstuffs using EPR.