Solid-state stability studies of crystal form of tebipenem

The aim of this study was to determine the kinetic and thermodynamic parameters of tebipenem degradation in the solid state. The process was analyzed based on the results obtained by a high performance liquid chromatography (HPLC) method using ultraviolet diode-array detector (DAD)/electrospray ionization tandem mass spectrometry (Q-TOF-MS/MS), Fourier transform infrared spectroscopy (FT-IR) and Raman spectroscopic (RS) studies. In dry air, the degradation of tebipenem was a first-order reaction depending on the substrate concentration while at an increased relative air humidity tebipenem was degraded according to the kinetic model of autocatalysis. The thermodynamic parameters: energy of activation (E_a), enthalpy (ΔH^≠a) and entropy (ΔS^≠a) of tebipenem degradation were calculated. Following a spectroscopic analysis of degraded samples of tebipenem, a cleavage of the β-lactam bond was proposed as the main degradation pathway, next confirmation using HPLC-Q-TOF-MS/MS method.     

Size and time dependent internalization of label-free nano-graphene oxide in human macrophages

Graphene oxide shows great promise as a material for biomedical applications,e.g.,as a multi-drug delivery platform.With this in view,reports of studies on the interaction between nanosized graphene oxide flakes and biological cells are beginning to emerge.However,the number of studies remains limited,and most used labeled graphene oxide samples to track the material upon endocytosis.Unfortunately,the labeling process alters the surface functionality of the graphene oxide,and this additional functionalization has been shown to alter the cellular response.Hence,in this work we used label-free graphene oxide.We carefully tracked the uptake of three different nanoscale graphene oxide flake size distributions using scanning/transmission electron microscopy.Uptake was investigated in undifferentiated human monocyte cells (THP-1) and differentiated macrophage cells.The data show clear size dependence for uptake,such that larger graphene oxide flakes (and clusters) are more easily taken up by the cells compared to smaller flakes.Moreover,uptake is shown to occur very rapidly,within two min of incubation with THP-1 cells.The data highlights a crucial need for cellular incubation studies with nanoparticles,to be conducted for short incubation periods as certain dependencies (e.g.,size and concentration) are lost with longer incubation periods.     

Carbon Monoxide and Nitric Oxide as Examples of the Youngest Class of Transmitters

The year 2021 is the 100th anniversary of the confirmation of the neurotransmission phenomenon by Otto Loewi. Over the course of the hundred years, about 100 neurotransmitters belonging to many chemical groups have been discovered. In order to celebrate the 100th anniversary of the confirmation of neurotransmitters, we present an overview of the first two endogenous gaseous transmitters i.e., nitric oxide, and carbon monoxide, which are often termed as gasotransmitters.     

Pd/polyaniline as the catalysts for 2‐ethylanthraquinone hydrogenation. The effect of palladium dispersion

By doping of polyaniline (PANI) in PdCl₂ aqueous and ethanol solutions the catalysts containing crystalline and colloidal Pd particles of different sizes were prepared. The size of palladium particles present in Pd/PANI catalysts (characterised by SEM and XRD methods) influenced the course of 2‐ethylanthraquinone (eAQ) hydrogenation, a key step in the industrial production of H₂O₂. The presence of large palladium particles promotes reactions leading to the formation of the so‐termed “degradation products” not capable of hydrogen peroxide formation. This revised version was published online in July 2006 with corrections to the Cover Date.     

Free-ranging European bisons accumulate more cadmium in the liver and kidneys than domestic cattle in north-eastern Poland

It has been shown that free-ranging big game animals accumulate several-fold more cadmium (Cd) in the liver and kidneys than domestic animals. To examine possible reasons for this difference, in the present work we determined the concentrations of Cd in the liver and kidney cortex of European bisons (n=23) from Bia?owieza Forest (north-eastern Poland) and domestic cattle (n=15) from the same region; in addition, analyses of Cd in the grasses and soil as well as of soil pH were carried out. The accumulation of Cd in liver and kidney cortex of the female bisons correlated significantly with the age up to 7 years, but stabilized thereafter. The 7-12-year-old bisons had 2.14- and 2.25-fold higher concentrations of Cd in the liver and kidney cortex, respectively, than the age-matched domestic cattle. Notably, the Cd levels in the liver and kidneys of the 8-12-year-old cattle were comparable to those found in the 2-year-old and 4-6-year-old bisons, respectively. The content of Cd in the grasses from Bia?owieza Forest appeared to be 2.1-fold higher than that in the plants from the pastures. Similarly, the concentration of water-extractable Cd in the soil was 2.7-fold greater in Bia?owieza Forest than in the pastures, despite the fact that nitric acid-extractable Cd (total Cd) was similar in the soils from the two sites. The concentration of water-extractable Cd in the soil as well as the content of Cd in the grasses inversely correlated with soil pH, which appeared to be significantly lower in Bia?owieza Forest. These data indicate that soil pH is probably responsible for the higher concentrations of Cd in the feed and tissues of bisons as compared with those of domestic cattle.     

Identification of eight coumarins occurring with psoralen,xanthotoxin, and bergapten on leaf surfaces

Surface extracts of the leaves of five species in the Umbelliferae,Citrus limon (Rutaceae), andPsoralea bituminosa (Leguminosae) were examined for the presence of coumarins, after a previous study had shown the presence of three psoralens. In the current investigation eight more coumarins were identified by mass spectrometric techniques: the simple coumarins scopoletin, scoparone, and osthol, the linear furanocoumarins imperatorin and phellopterin, the angular furanocoumarins angelicin and pimpinellin, and the pyranocoumarin seselin. Five of these occur inApium graveolens, and scopoletin, scoparone, and imperatorin were each found in three of the species examined. The co-occurrence of all these coumarins on the surface may be significant in communication between the plant and its environment.     

Influence of low-intensity ultraviolet radiation on extrusion of furanocoumarins to the leaf surface

Exposure ofRuta graveolens leaves to low intensity 366-nm radiation led to a ca. 20% increase in concentrations of the furanocoumarins psoralen, xanthotoxin and bergapten, as compared to leaves kept in darkness. Both direct and, even more, scattered UV radiation produced increases in total concentrations. Changes in the concentrations of individual coumarins were generally parallel. Extrusion to the surface was increased, especially in lower, older leaves exposed to the scattered radiation, where it exceeded the control by factors of eight or nine. It is suggested that this response could enhance shielding of leaves against penetration of UV into the cells and that irradiation, by exciting the furanocoumarins, could augment protection against potential microbial invaders.     

Genetic variation in the extract viscosity of rye (Secale cereale L.) bread made from endosperm and wholemeal flour: impact of high-molecular-weight arabinoxylan, starch and protein

BACKGROUND: To verify the viscous potential of rye bread made from population and hybrid cultivars, the overall extract viscosities (EVs) of endosperm and wholemeal breads (EBs and WMBs respectively) were assessed using extractants of different pH. Also, arabinoxylan‐dependent EV (AX‐EV) was determined after combined action of starch‐ and protein‐degrading enzymes. RESULTS: The synergistic effect of a combination of α‐amylase, amyloglucosidase and protease on EV was almost two times higher than the effects observed after single addition of each of them. However, water‐extractable arabinoxylans (WE AXs) were the major contributors to EV. Unexpectedly, a decrease in the mean WE AX contents observed in the following order, WMB (31.7 g kg^?1) and EB (29.3 g kg^?1) of hybrid rye and WMB (28.8 g kg^?1) and EB (23.8 g kg^?1) of population rye, was accompanied by an increase in their AX‐EVs (12, 21, 21 and 29 mPa s respectively). CONCLUSION: In some cases the structure of WE AXs is a more important determinant of AX‐EV than their content in rye bread. Nevertheless, both factors influence AX‐EV, which may reflect the viscosity of the human small intestine after rye bread consumption, related to some beneficial metabolic effects. Therefore AX‐EV can be a preliminary parameter for selection towards high‐viscosity bread. Copyright © 2010 Society of Chemical Industry