ABSTRACT We used dedicated magnetic resonance imaging (MRI) equipment and methods to study phloem xylem transport in large potted plants. Quantitative flow profiles were obtained on a per‐pixel basis, giving parameter maps of velocity, flow‐conducting area volume (flux). The diurnal dynamics poplar, castor bean, tomato tobacco compared. In clear differences profile found, but flux remained constant. tomato, only small observed. bean tobacco, unchanged. all plants, showed variation. Decreases...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTIntramolecular Interactions in the Ground and Excited States of Tetrakis(N-methylpyridyl)porphyrinsFrank J. Vergeldt, Rob B. M. Koehorst, Arie van Hoek, Tjeerd SchaafsmaCite this: Phys. Chem. 1995, 99, 13, 4397–4405Publication Date (Print):March 1, 1995Publication History Published online1 May 2002Published inissue 1 March 1995https://pubs.acs.org/doi/10.1021/j100013a007https://doi.org/10.1021/j100013a007research-articleACS PublicationsRequest...

Due to the fragile pressure gradients present in xylem and phloem, methods study sap flow must be minimally invasive. Magnetic resonance imaging (MRI) meets this condition. A dedicated MRI method has been applied quantify long-distance hydraulics an intact cucumber (Cucumis sativus) plant. The accuracy of effective flow-conducting area is demonstrated by measuring characteristics water a virtual slice through stem comparing results with uptake data microscopy. in-plane image resolution 120 x...

Monolayers of a series 1-alkynes, from 1-dodecyne to 1-octadecyne, have been prepared on the hydrogen-terminated Si(100) surface via thermal reaction organic compound with this Si surface. An efficient procedure is presented for synthesis 1-alkynes corresponding 1-alkenes. The resulting monolayers were characterized by water contact angle measurements, ATR infrared spectroscopy, and X-ray reflectivity. results show that these give well-ordered, covalently bonded monolayers, which are at...

Several processes during sexual reproduction in higher plants involve the movement of water between cells or tissues. Before flower anthesis, anther and pollen dehydration takes place before release mature at dehiscence. Aquaporins represent a class proteins that mediates over cellular membranes. plasmamembrane PIP2 family are expressed tobacco (Nicotiana tabacum) anthers may therefore be involved this organ. To gain more insight into role these play process, we have analyzed their...

This article presents a facile strategy to combine Eu3+ and Gd3+ ions into coacervate core micelles in controlled way with statistical distribution of the ions. Consequently, formed show high tunability between luminescence relaxivity. These highly stable present great potential for new materials, e.g. as bimodal imaging probes.

Pulsed field gradient nuclear magnetic resonance has been successfully applied to a direct and detailed experimental study of topological dynamic aspects involved in the exchange small, nonsorbed fluid molecules between intraparticle pore network interparticle void space chromatographic columns packed with spherical-shaped, porous particles. The approach provides quantitative data about effective, diffusion coefficients (and tortuosity factors) associated, diffusion-limited mass transfer...

Gastric digestion is crucial for protein breakdown. Although it has been widely studied with in vitro models, verification vivo remains a big challenge. Magnetic resonance imaging (MRI) the potential to bridge this gap. Our objective was use transverse relaxation time (T2) and rate (R2 = T2−1) monitor hydrolysis of protein-rich food during gastric digestion. Whey solution heat-induced hydrogels were digested by means simulated fluid (SGF). Free amino groups (–NH2 groups) concentration...

The effect of osmotic stress (−0.35 MPa) on the cell water balance and apical growth was studied non‐invasively for maize (Zea mays L., cv. LG 11) pearl millet (Pennisetumamericanum MH 179) by 1H NMR microscopy in combination with uptake measurements. Single parameter images content transverse relaxation time (T2) were used to discriminate between different tissues follow status region during stress. T2 values non‐stressed stem tissue turned out be correlated dimensions as determined optical...

The use of microbial fuel cells (MFCs) for wastewater treatment fits in a circular economy context, as they can produce electricity by the removal organic matter wastewater. Activated carbon (AC) granules are an attractive electrode material bioanodes MFCs, cheap and provide electroactive bacteria with large surface area attachment. characterization biofilm growth on AC granules, however, is challenging due to their high roughness three-dimensional structure. In this research, we show that...

Abstract A flavodoxin from Azotobacter vinelandii is chosen as a model system to study the folding of α/ß doubly wound proteins. The guanidinium hydrochloride induced unfolding apoflavodoxin demonstrated be reversible. Apoflavodoxin thus can fold in absence FMN cofactor. curves obtained for wild‐type, C69A and C69S monitored by circular dichroism fluorescence spectroscopy do not coincide. occurs therefore via simple two‐state mechanism. experimental data described three‐state mechanism...

• Changes in the physical state of cellular water and its interrelations with carbohydrate metabolism were studied during preplanting storage tulip bulbs (Tulipa gesneriana'Apeldoorn'). Magnetic resonance imaging, light scanning electron microscopy high-performance anion exchange chromatography pulsed amperometric detection used to follow time-dependent changes bulb at 17 or 20°C (nonchilled) 4°C (chilled). No visible differences scale structure central bud development observed...

Abstract The gas‐liquid distribution in a monolith film flow reactor is investigated the scope of this work. Magnetic resonance imaging (MRI) and customized liquid collection method have been successfully applied to determine over cross‐section. Using well‐positioned spray nozzle distributor, very uniform distributions are found which address needs for applications that require high single‐pass conversions. Due lack radial convective monoliths, initial propagates through reactor. With...

Abstract: Proton nuclear magnetic resonance ( 1 H‐NMR) relaxometry was used to study the effects of high pressure and thermal processing on membrane permeability cell compartmentalization, important components plant tissue texture. High treated onions were subjected levels from 20 200 MPa at 5 min hold time initial temperatures °C. Thermally exposed for 30 40 90 Loss integrity clearly shown by changes in transverse relaxation (T 2 ) water 60 °C above. Destabilization membranes observed as...

Magnetic resonance imaging (MRI) offers unique opportunities to monitor moisture transport during drying or heating of food, which can render unexpected insights. Here, we report about MRI observations made the broccoli stalks indicating anomalous behaviour. In fresh samples content in core sample increases drying, conflicts with Fickian diffusion. We have put hypothesis that this increase is due stress diffusion induced by elastic impermeable skin. Pre-treatments change skin and bulk...