Relaxation Properties Research Articles

The Submonolayer Structure of Ni(111)–(√3 × √3)R30°–Pb: Atomic Relaxation and Vibrational Properties

The Submonolayer Structure of Ni(111)–(√3 × √3)R30°–Pb: Atomic Relaxation and Vibrational Properties

Tangential Shear Stress in Oscillatory Flow of a Viscoelastic Incompressible Fluid in a Plane Channel

The problems of oscillatory flow of a viscoelastic incompressible fluid in a plane channel are solved for a given harmonic oscillation of the fluid flow rate. The transfer function (amplitude–phase frequency response) is determined. Using this function, the effect of the acceleration oscillation frequency and the relaxation properties of fluid on the ratio of the tangential shear stress on channel wall to the velocity averaged over the channel cross-section (cross-sectional velocity) is determined. It is shown that the viscoelastic properties of fluid, as well as its acceleration, are the limiting factors for using the quasi-stationary approach. The found formulas for determining the transfer function for viscoelastic fluid flow in the case of non-stationary stream make it possible to determine the dissipations of mechanical energy in a non-stationary flow of the medium which are of importance for calculation of the control of hydraulic and pneumatic systems.

An Exploratory Study on the Use of Biobinder Derived from Brewer’s Spent Grains as an Asphalt Modifier

The production of asphalt concrete depends on the use of nonrenewable resources, such as asphalt binder and crushed rocks. Nowadays, technologies exist to convert biomass into biofuels and other by-products, which are an alternative to traditional sources of energy. The by-products of biomass conversion are similar to those of petroleum distillation. Several researchers have investigated the use of bio-oils from biomass as asphalt additives, but the potential use of brewery waste has not been considered. In this project, spent grains from a local brewery were converted into bio-oil using an auger reactor. The water in the bio-oil was removed, and the biobinder was analyzed. It was found that the biobinder derived from brewer’s spent grain has an elemental composition similar to other biomass-derived biobinders. Fourier transform infrared (FTIR) spectroscopy identified multiple polar functional groups in the biobinder, including high nitrogen content (4.6% by weight). Also, thermogravimetric analysis and gas chromatography showed a higher thermal degradation rate of the biobinder and loss of volatile components. The biobinder was used to create six blends with 5%, 8%, 10%, 15%, 20%, and 25% replacement of asphalt. The performance of each of the six blends was compared with the performance of control unmodified samples. The modified binder characterization indicated that the biobinder makes the material more susceptible to permanent deformation at high temperatures, and it showed higher aging of the short-term aged residue. However, the biobinder seems to improve relaxation properties at low temperatures, which could be attributed to its high nitrogen content. The findings of this preliminary study suggest that production and use of brewer’s spent grain biobinder are feasible and could be considered a potential feedstock for further development of asphalt biomodifiers.

Stationary time correlations for fermions after a quench in the presence of an impurity

We consider the quench dynamics of non-interacting fermions in one dimension in the presence of a finite-size impurity at the origin. This impurity is characterized by general momentum-dependent reflection and transmission coefficients which are changed from to at time t = 0. The initial state is at equilibrium with such that the system is cut in two independent halves with , , respectively, to the right and to the left of the impurity. We obtain the exact large time limit of the multi-time correlations. These correlations become time translationally invariant, and are non-zero in two different regimes: i) for where the system reaches a non-equilibrium steady state (NESS), ii) for , i.e., the ray regime. For a repulsive impurity these correlations are independent of , , while in the presence of bound states they oscillate and memory effects persist. We show that these nontrivial relaxational properties can be retrieved in a simple manner from the large time behaviour of the single particle wave functions.

Benzodiazepines: Kamo griadeshi?

BENZODIAZEPINES: KAMO GRIADESHI? Mykolay Ya. Golovenko A. V. Bogatsky Physico-Chemical Institute of the National Academy of Sciences of Ukraine, Lyustdorfs’ka doroha Str., 86, Odesa 65080, Ukraine Introduction. Benzodiazepines are among the most prescribed medications in the world because of their demonstrated effectiveness at treating serious physical and mental disorders. The high frequency of clinical use is because of their anxiolytic, anticonvulsant, amnestic, muscle relaxant, and sedative-hypnotic properties. Unfortunately, benzodiazepines also cause unwanted side effects, for example excessive (or unwanted) sedation, tolerance, dependence, and a abuse. The aim – by combining own pharmacological and medical studies together with the systematized literature data to determine the historical circumstances, which facilitated BDZs to lead the all the lists of "the most frequently prescribed" following by oblivion. To set up the future way marks for these compounds. Quo vadis, BDZs? And toward what our path lies? To foresee the possible obstacles and challenges on the thorny way of use of well-known and creating of innovative BDZs derivatives. Materials and methods. When writing the review, searches were undertaken in two representative databases: PubMed and Google Scholar. The search of scientific articles published from 1970 to 2022 was performed. Results and conclusions. The available publication data were systemized and the brief information concerning the BDZs derivatives administration was provided. It was found that in most of the cases throughout the long period, BDZs perceiving still remains negatively biased without substantial scientific background. More and more often the appeals rise to renew the deliberations of problems of the medical use of BDZs in adherence to the exact prescriptions and conceptual stringency in the related comments. The social aspects of benzodiazepines administrations were discussed. The common conclusion was made that benzodiazepines use in the ranges of corresponding medical practice significantly overbalances the possible problems. Considered the possibilities of creating selective innovative medicines as new BDZs derivatives and the conveniences of their use. Keywords: benzodiazepines, indications, side effects, «designer benzodiazepine», improving access.

Lesser galangal (Alpinia officinarum Hance) essential oil incorporated biodegradable PLA/PBS films as shelf-life extension packaging of cooked rice

Adding natural essential oils to biodegradable polymers produces functional active packaging that reduces food loss and package waste. Polylactic acid and polybutylene succinate (PLA/PBS) films were produced via cast extrusion and blended with lesser galangal (Alpinia officinarum Hance.) essential oils (EO) at up to 6 %. Effects of EO and PLA/PBS ratios on morphology, relaxation, crystallinity and film properties were investigated. Results indicated that plasticization effects of EO reduced α-relaxation temperature and crystallinity, decreasing tensile strength by up to 22 %, while permeability of water vapor and oxygen increased by up to 42 % and 29 %, respectively. Interaction between EO and PLA/PBS shifted the diffraction angle, suggesting modified crystal morphology. EO enhanced melting of PBS giving smoother microstructures and reduced aggregates in the film matrices, contributing to lower surface roughness and hydrophobicity. Films were placed into packages of freshly steamed glutinous rice, allowing release of volatile lesser galangal EO majorly consisted of β-ocimene, 2-bornanone, eucalyptol and geraniol as determined by GC/MS. PLA/PBS films with lower PLA contents containing EO showed higher efficacy to delay fungal growth in cooked glutinous rice. Total microbial viable counts were significantly lower in packages containing EO above 4 %. PLA/PBS/EO films effectively extended the shelf-life of cooked glutinous rice by more than 2-fold depending on EO concentrations and PLA/PBS ratios due to release of volatiles into the headspace. Essential oil release from film interface into vapor and liquid phases showed antimicrobial functions which delayed mold and bacterial growth.

Feasibility of in vivo multi-parametric quantitative magnetic resonance imaging of the healthy sciatic nerve with a unified signal readout protocol

Magnetic resonance neurography (MRN) has been used successfully over the years to investigate the peripheral nervous system (PNS) because it allows early detection and precise localisation of neural tissue damage. However, studies demonstrating the feasibility of combining MRN with multi-parametric quantitative magnetic resonance imaging (qMRI) methods, which provide more specific information related to nerve tissue composition and microstructural organisation, can be invaluable. The translation of emerging qMRI methods previously validated in the central nervous system to the PNS offers real potential to characterise in patients in vivo the underlying pathophysiological mechanisms involved in a plethora of conditions of the PNS. The aim of this study was to assess the feasibility of combining MRN with qMRI to measure diffusion, magnetisation transfer and relaxation properties of the healthy sciatic nerve in vivo using a unified signal readout protocol. The reproducibility of the multi-parametric qMRI protocol as well as normative qMRI measures in the healthy sciatic nerve are reported. The findings presented herein pave the way to the practical implementation of joint MRN-qMRI in future studies of pathological conditions affecting the PNS.

In silico pharmacology and bioavailability of bioactive constituents from Triclisia subcordata (Oliv), an underutilized medicinal plant in Nigeria

Medicinal plants are rich sources of traditional medicines from which many modern medicines are made. Triclisia subcordata Oliv. is one among the underutilized medicinal plants in the Southwestern part of Nigeria. Therefore, this study was designed to present comprehensive data from the literature on pharmacological uses of T. subcordata and its phytochemistry, and to predict the pharmacology and bioavailability of the phytoconstituents isolated so far from Triclisia subcordata through an in silico approach. T. subcordata has high antioxidant activity and so it isthus used to treat oxidative stress-related diseases such as inflammation and diabetes. It also has antibacterial, antifungal, antimalarial and smooth muscle relaxing properties. It is a potent inhibitor of enzymes such as alpha-amylase and alpha-glucosidase. It has also traditionally been used in cancer treatment. One of the bisbenzylisoquinoline (BBIQ) alkaloids isolated from this plant, cycleanine, showed selectivity for ovarian cancer cell lines. The presence of phytochemicals such as cyanogenic glycosides and tannins in low concentrations in T. subcordata has also been reported to make it edible to humans. The results of predicted absorption, distribution, metabolism, excretion and toxicity was analyzed on the webserver ’ADEMTLab 2.0‘ . Prediction of activity studies for the four bisbenzylisoquinoline alkaloids isolated so far from this plant supported anticancer, antimicrobial, antidiabetic, antiulcer, antimalarial activities as well as muscle relaxant effect. Moreover, new activities including stimulation of leukopoiesis, inhibition of membrane permeability , inhibition of kinase and nicotinic alpha4beta4 receptor agonist properties were also predicted through in silico investigation. From our findings, these phytoconstituents could be lead candidates in drug discovery, since this plant is safe for human consumption.

Ab-initio study of [formula omitted] molecule adsorption on Si(001)-p(2 × 2) reconstructed surface

First-principles calculations are performed to investigate the relaxation and electronic properties of SiF2 molecule deposited on surface. The reconstructed Si(001)-p(2 × 2) surface, modeled using density functional theory method, forms the basis for our molecule adsorption study. Several adsorption configurations corresponding to different orientations of the molecule have been investigated. Both stable dissociative and non-dissociative adsorption are found. For the most stable configuration, the adsorption takes place without dissociation of the molecule whose silicon atom binds two atoms of the surface. The progressive decomposition process of SiF2 is also explored using the nudged elastic band (NEB) method. An important energy barrier is obtained for the SiF2 molecule decomposition as compared to that of the SiF molecule. This could explain the high percentage of the SiF2 volatile molecule observed experimentally during the fluoride plasma etching process on the Si(001) surface.

Role of ultrasonography, magnetic resonance imaging in evaluation of female pelvic masses with histopathological correlation

Adnexal mass that can be suspected as malignant with ultrasonography can be diagnosed as benign lesion at magnetic resonance imaging (MRI). This will help in preventing inappropriate surgery. MRI gives additional information on composition of soft-tissue masses using differences in MR relaxation properties in various tissue, which is not seen in ultrasonography. To evaluate pelvic pathology by ultrasound and MRI for differentiating malignant and benign tumors in adnexal masses compared with histopathology Prospective comparative study was carried out among 30 patients with suspected pelvic masses. Thorough clinical history was taken followed by physical examination. Clinically or ultrasonographically detected suspicious pelvic masses were subjected to MRI and correlated histopathologically. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated for ultrasonography and MRI with histopathology as gold standardMajority were <50 years. Bleeding per vaginum and pain abdomen were most common symptoms in 20% each. As per ultrasonography, most common diagnosis was adnexal mass in 36%. As per MRI, most common diagnosis was ovarian pathology in 47%. As per histopathology, most common diagnosis was cervical cancer, fibroids and benign ovarian pathologies in 20% of cases each. Sensitivity, specificity, PPV and NPV of USG compared to histopathology was 88.2%; 61.5%; 75% and 80% respectively. Sensitivity, specificity, PPV and NPV of MRI compared to histopathology was 100%; 92.8%; 84.1% and 100% respectively. On comparison, MRI had better diagnostic accuracy than USG MRI is a very sensitive imaging modality for the evaluation of female patients with suspected or confirmed adnexal masses and disease extent is better evaluated than ultrasonography.

Insight into the Effect of Glycerol on Dielectric Relaxation and Transport Properties of Potassium-Ion-Conducting Solid Biopolymer Electrolytes for Application in Solid-State Electrochemical Double-Layer Capacitor.

The increased interest in the transition from liquid to solid polymer electrolytes (SPEs) has driven enormous research in the area polymer electrolyte technology. Solid biopolymer electrolytes (SBEs) are a special class of SPEs that are obtained from natural polymers. Recently, SBEs have been generating much attention because they are simple, inexpensive, and environmentally friendly. In this work, SBEs based on glycerol-plasticized methylcellulose/pectin/potassium phosphate (MC/PC/K3PO4) are investigated for their potential application in an electrochemical double-layer capacitor (EDLC). The structural, electrical, thermal, dielectric, and energy moduli of the SBEs were analyzed via X-ray diffractometry (XRD), Fourier transforms infrared spectroscopy (FTIR), electrochemical impedance spectroscopy (EIS), transference number measurement (TNM), and linear sweep voltammetry (LSV). The plasticizing effect of glycerol in the MC/PC/K3PO4/glycerol system was confirmed by the change in the intensity of the samples' FTIR absorption bands. The broadening of the XRD peaks demonstrates that the amorphous component of SBEs increases with increasing glycerol concentration, while EIS plots demonstrate an increase in ionic conductivity with increasing plasticizer content owing to the formation of charge-transfer complexes and the expansion of amorphous domains in polymer electrolytes (PEs). The sample containing 50% glycerol has a maximal ionic conductivity of about 7.5 × 10-4 scm-1, a broad potential window of 3.99 V, and a cation transference number of 0.959 at room temperature. Using the cyclic voltammetry (CV) test, the EDLC constructed from the sample with the highest conductivity revealed a capacitive characteristic. At 5 mVs-1, a leaf-shaped profile with a specific capacitance of 57.14 Fg-1 was measured based on the CV data.

Polymer composition optimization approach based on feature extraction of bound and free water using time-domain nuclear magnetic resonance

As global environmental sustainability becomes increasingly emphasized, the development of eco-friendly materials, including solutions to the issue of marine plastics, is thriving. However, the material parameter space is vast, making efficient search a challenge. Time-domain nuclear magnetic resonance offers material property information through the complex T2 relaxation curves resulting from multiple mobilities. In this research, we used the Carr–Purcell–Meiboom–Gill (CPMG) pulse sequence to evaluate the binding state of water (water affinity) in polymers synthesized with various monomer compositions, which were immersed in seawater. We also assessed the T2 relaxation property of the polymers using the magic sandwich echo, double quantum filter, and magic-and-polarization echo filter techniques. We separated the T2 relaxation curves of CPMG into free and bound water for polymers by employing semisupervized nonnegative matrix factorization. By employing the features of separated bound water and polymer properties, a polymer composition optimization method offered crucial factors to monomers through random forests, predicted the components of the polymer using generative topography mapping regression, and determined expected values using Bayesian optimization for polymer composition candidates with the desired high water affinity and high rigidity.

Proton Pump Dysfunction and Upregulation of Caspase-3 Activity via Oxidative-Sensitive Signaling Mediate Rohypnol-Induced Testicular Toxicity

Rohypnol is a benzodiazepine that is used for its anxiolytic, anticonvulsant, muscle relaxant, and hypnotic properties, but commonly abused. It has been reported to induce sexual dysfunction; however, its effect on testicular integrity and sperm quality is yet to be documented. This study evaluated the impact of Rohypnol on testicular integrity, circulatory testosterone, spermatogenesis, and sperm quality. The likely role of oxidative stress-dependent pathway as well as testicular proton pumps and caspase-3 activity in Rohypnol-induced modulation of male reproductive function was explored. In this study, adult male rats were randomized into six groups of six rats each: the control received 1 ml of distilled water as vehicle, while the low- and high-dose Rohypnol-treated groups received 2 mg/kg and 4 mg/kg of Rohypnol for four weeks. The control-, low-, and high-dose recovery groups received 2 mg/kg and 4 mg/kg of Rohypnol for four weeks, respectively, which was followed by a 4-week drug-free recovery period. Rohypnol treatments led to impaired steroidogenesis and spermatogenesis and low sperm quality. This was accompanied by a rise in the markers of testicular injury, oxidative stress, inflammation, and apoptosis. Also, the activities of testicular enzymatic antioxidants and proton pumps were significantly reduced. Although the impacts of low-dose Rohypnol treatment were partially reversible, those of the high-dose Rohypnol treatment were not. Histopathological findings on the testicular tissues were in tandem with the biochemical alterations. Thus, it is safe to infer that Rohypnol induces testicular damage by the suppression of Na+/K+-ATPase and Ca2+-ATPase and the activation of caspase-3 through an oxidative-sensitive signaling pathway.

Different spin relaxation properties observed in linearly and circularly polarized laser induced terahertz emission from a Bi/Co bilayer

Recently, helicity-dependent photocurrent was reported in Bi single thin fi lms. It is proposed that the origin of this photocurrent is the combination of photo-spin conversion and spin-charge conversion effects in Bi and efficient spin conversion in Bi is expected. In this study, we measured two types of terahertz (THz) emissions from Bi/Co bilayer films induced by spin current generation using laser-induced demagnetization of the Co layer and photo-spin conversion effect in the Bi layer to investigate the spin current induced by the two mechanisms simultaneously. We clearly observed diff erent Bi thickness dependence of peak intensity and that of bandwidth for THz spin current in two experiments, i.e., spin current induced by demagnetization of Co and that by photo-spin conversion in Bi. The different Bi thickness dependence of spin current intensity and bandwidth in two experiments is caused by different spin relaxation properties of optically excited spin currents in Bi layers.

Impedance spectroscopy and DFT/TD-DFT studies of diyttrium trioxide for optoelectronic fields

Yttrium (III) oxide or so-called diyttrium trioxide (Y 2 O 3 ) is an excellent candidate ceramic material for optoelectronic applications. Structural, electrical conductivity, and dielectric relaxation properties of bulk yttrium (III) oxide are studied. X-ray diffraction (XRD) results indicate that the yttrium (III) oxide compound has a crystalline cubic phase. FTIR technique is used to ascertain the chemical structure of the yttrium (III) oxide compound. Impedance spectroscopy was used to analyze frequency-dependent electrical properties as a function of temperature in the range of 303–423 K and frequency range 0.1 Hz–2 MHz. Impedance spectroscopy parameters such as dielectric constant, dielectric loss, loss factor, electric modulus, and complex impedance of the yttrium (III) oxide compound have been studied. The Nyquist plot describes the complex impedance of the yttrium (III) oxide for different temperatures. The universal Jonscher’s power law was used for the analysis of the complex electrical conductivity of the yttrium (III) oxide compound. It is found that the real ( σ ′ ) and imaginary ( σ ˊ ˊ ) parts of the complex conductivity increase with increasing frequency. The exponent frequency (s) equals unity which confirms that the predominant conduction mechanism is a nearly constant loss (NCL) mechanism. DFT/TD-DFT studies using B3LYP/LanL2DZ level of theory were used to provide comparable theoretical data and electronic energy gap of HOMO→LUMO. Spatial plot of HOMO and LUMO of yttrium (III) oxide with their energy gap.

Characterization of styrene-butadiene-styrene (SBS)-modified asphalt binders using the bending beam rheometer and the asphalt binder cracking device

The addition of styrene butadiene styrene (SBS) to asphalt binders has led to enhanced performance in pavements across the entire range of working temperatures. SBS-modified binders have also proven to be more difficult to characterize in terms of their rheological properties. Low-temperature properties of asphalt binders are typically evaluated using the bending beam rheometer (BBR), which was developed to measure creep stiffness. Recent refinements to the BBR analysis have led to the development of Δ Tc which is meant to provide more insight into the relaxation properties of the binder. The Asphalt Binder Cracking Device (ABCD) was developed to improve on this characterization by also taking into consideration the failure strength and coefficient of thermal contraction. Previous research has shown that the ABCD provides more valuable insight into the effect of SBS on the low-temperature properties of asphalt binders. This paper will evaluate the ability of these two low-temperature tests to characterize the performance of five different asphalt binders with increasing concentrations of SBS. It was found that the evaluation of the materials using Δ Tc was inconsistent with binder type and generally indicated that SBS reduced cracking resistance, while the ABCD critical temperature and the proposed Δ Tf parameter generally showed an improved correlation with SBS concentration.

Spin-lattice relaxation time in water/graphene-oxide dispersion.

We present the results of the calculations of the spin-lattice relaxation time of water in contact with graphene oxide by means of all-atom molecular dynamics simulations. We fully characterized the water-graphene oxide interaction through the calculation of the relaxation properties of bulk water and of the contact angle as a function of graphene oxide oxidation state and comparing them with the available experimental data. We then extended the calculation to investigate how graphene oxide alters the dynamical and relaxation properties of water in different conditions and concentrations. We show that, despite the diamagnetic nature of the graphene oxide, the confining effects of the bilayers strongly affect the longitudinal relaxation properties of interfacial water, which presents a reduced dynamics due to hydrogen bonds with oxygen groups on graphene oxide. This property makes graphene oxide an interesting platform to investigate water dynamics in confined geometries and an alternative contrast-agent for magnetic resonance imaging applications, especially in view of the possibility to functionalize graphene oxide from theranostic perspectives.

Formation of Elastomeric Composition Properties in the Presence of Bioingredient

Peculiarities of formation of technological, vulcanization, dynamic, relaxation, and physicomechanical properties of elastomeric composition used for the tread production have been studied in the presence of bioingredient as a plasticizer-softener. Bioingredient is an organic component of sunflower oil winterization by-product (OSSO product). It was found that the OSSO product increases the cohesive strength of the rubber compound by 1.5 times in comparison with the industrial petrochemical lubricants. Under the same vulcanization conditions, the bioingredient provides 30–40 % higher resistance to reversion and relaxation processes at 373 K, lower dynamic losses, as well a high level of physical and mechanical characteristics.

Laboratory Investigation of Storage Stability and Aging Resistance of Slightly SBS-Modified Bitumen Binders

Slightly SBS-modified bitumen binders have been applied for the asphalt concrete impermeable layer of pumped storage power stations (PSPSs) in China. However, the storage stability and aging resistance of slightly SBS-modified bitumen are big concerns. In this study, three different types of slightly SBS-modified bitumen binders were evaluated by using a commonly used virgin bitumen and a normal SBS polymer-modified bitumen as references. All of the bitumen binders were subjected to short-term and long-term aging that were simulated by using a 5 h and 24 h thin film oven test (TFOT), respectively. A Fourier transform infrared (FTIR) spectroscopy test, storage stability test, dynamic shear rheological test, stress relaxation test, and direct tensile (DT) test were carried out to obtain insight into the storage stability and aging resistance. FTIR analysis indicated that slightly SBS modified bitumen exhibited serious aging of base bitumen together with higher polymer degradation. The aging indexes obtained from the carbonyl index and the polybutadiene (PB) index can well rank the aging resistance. Slightly SBS-modified bitumen binders had excellent storage stability, and even after a long-term period of 7 days of storage, the complex modulus and phase angle remained fairly constant. The rheological master curves were constructed to investigate the effects of short-term and long-term aging. Slightly modified bitumen binders were well identified by the plateau of the phase angle master curves. The aging resistance was well distinguished by the deviation of the complex modulus master curve using unaged bitumen as a baseline. It was found that three types of slightly SBS-modified bitumen binders exhibited inconsistent aging resistance in terms of rheological aging index. The relative change of the initial instantaneous modulus and the modulus relaxation rate was able to explain the relaxation properties. With respect to the direct tensile test, the increase in stiffness modulus and the loss of ultimate tensile strain can be used to evaluate the susceptibility of bitumen aging. An attempt was made to establish the relationship of the aging index between FTIR analysis, rheological properties, and low-temperature performance. It was found that the relationship among these aging indexes was weak. In general, slightly SBS modified bitumen should be well designed to obtain good aging resistance and low-temperature performance. Highly modified bitumen is foreseen to be promising in the case of extremely low temperatures and long-term durability.

Suramin Affects the Renal VEGF-A/VEGFR Axis in Short-Term Streptozotocin-Induced Diabetes

Diabetic nephropathy (DN) accounts for approximately 50% of end-stage renal diseases. Vascular endothelial growth factor A (VEGF-A) is thought to be a critical mediator of vascular dysfunction in DN, but its role is unclear. The lack of pharmacological tools to modify renal concentrations further hinders the understanding of its role in DN. In this study, rats were evaluated after 3 weeks of streptozotocin-induced diabetes and two suramin treatments (10 mg/kg, ip). Vascular endothelial growth factor A expression was evaluated by western blot of glomeruli and immunofluorescence of the renal cortex. RT-PCR for receptors Vegfr1 mRNA and Vegfr2 mRNA quantitation was performed. The soluble adhesive molecules (sICAM-1, sVCAM-1) in blood were measured by ELISA and the vasoreactivity of interlobar arteries to acetylcholine was evaluated using wire myography. Suramin administration reduced the expression and intraglomerular localisation of VEGF-A. Increased VEGFR-2 expression in diabetes was reduced by suramin to non-diabetic levels. Diabetes reduced the sVCAM-1 concentrations. Suramin in diabetes restored acetylcholine relaxation properties to non-diabetic levels. In conclusion, suramin affects the renal VEGF-A/VEGF receptors axis and has a beneficial impact on endothelium-dependent relaxation of renal arteries. Thus, suramin may be used as a pharmacological agent to investigate the potential role of VEGF-A in the pathogenesis of renal vascular complications in short-term diabetes.