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Daniel Oltean-Dan,1 Gabriela-Bombonica Dogaru,2 Maria Tomoaia-Cotisel,3,4 Dragos Apostu,1 Alexandru Mester,5 Horea-Rares-Ciprian Benea,1 Mihai-Gheorghe Paiusan,1 Elena-Mihaela Jianu,6 Aurora Mocanu,3 Reka Balint,3 Catalin-Ovidiu Popa,7 Cristian Berce,8 Gyorgy-Istvan Bodizs,9 Alina-Mihaela Toader,10 Gheorghe Tomoaia1,41Iuliu Hatieganu University of Medicine and Pharmacy, Department of Orthopedics and Traumatology, 400132 Cluj-Napoca, Romania; 2Iuliu Hatieganu University of Medicine and Pharmacy, Department of Medical Rehabilitation, 400347 Cluj-Napoca, Romania; 3Babes Bolyai University, Faculty of Chemistry and Chemical Engineering, Department of Chemical Engineering, Research Center of Physical Chemistry, 400028 Cluj-Napoca, Romania; 4Academy of Romanian Scientists, 050085 Bucharest, Romania; 5Iuliu Hatieganu University of Medicine and Pharmacy, Department of Oral Rehabilitation, Oral Health and Management, 400012 Cluj-Napoca, Romania; 6Iuliu Hatieganu University of Medicine and Pharmacy, Department of Histology, 400349 Cluj-Napoca, Romania; 7Technical University of Cluj-Napoca, Department of Materials Science and Engineering, 400641 Cluj-Napoca, Romania; 8Iuliu Hatieganu University of Medicine and Pharmacy, Center for Experimental Medicine, 400349 Cluj-Napoca, Romania; 9Rehabilitation Clinic, 400347 Cluj-Napoca, Romania; 10Iuliu Hatieganu University of Medicine and Pharmacy, Department of Physiology, 400006 Cluj-Napoca, RomaniaPurpose: Bone consolidation after severe trauma is the most challenging task in orthopedic surgery. This study aimed to develop biomimetic composite for coating Ti implants. Afterwards, these implants were tested in vivo to assess bone consolidation in the absence or the presence of high-frequency pulsed electromagnetic short-waves (HF-PESW).Materials: Biomimetic coating was successfully developed using multi-substituted hydroxyapatite (ms-HAP) functionalized with collagen (ms-HAP/COL), embedded into poly-lactic acid (PLA) matrix (ms-HAP/COL@PLA), and subsequently covered with self-assembled COL layer (ms-HAP/COL@PLA/COL, named HAPc).Methods: For in vivo evaluation, 32 Wistar albino rats were used in four groups: control group (CG) with Ti implant; PESW group with Ti implant+HF-PESW; HAPc group with Ti implant coated with HAPc; HAPc+PESW group with Ti implant coated with HAPc+HF-PESW. Left femoral diaphysis was fractured and fixed intramedullary. From the first post-operative day, PESW and HAPc+PESW groups underwent HF-PESW stimulation for 14 consecutive days. Biomimetic coating was characterized by XRD, HR-TEM, SEM, EDX and AFM.Results: Osteogenic markers (ALP and osteocalcin) and micro-computed tomography (CT) analysis (especially bone volume/tissue volume ratio results) indicated at 2 weeks the following group order: HAPc+PESW>HAPc≈PESW (P>0.05) and HAPc+PESW>control (P

The development of low-cost, sensitive, and simple analytical tools for biomolecule detection in health status monitoring is nowadays a growing research topic. Sensing platforms integrating nanocomposite materials as recognition elements in the monitoring of various biomolecules and biomarkers are addressing this challenging objective. Herein, we have developed electrochemical sensing platforms by means of a novel fabrication procedure for biomolecule detection. The platforms are based on commercially available low-cost conductive substrates like glassy carbon and/or screen-printed carbon electrodes selectively functionalized with nanocomposite materials composed of Ag and Au metallic nanoparticles and an organic polymer, poly(3,4-ethylenedioxythiophene). The novel fabrication method made use of alternating currents with controlled amplitude and frequency. The frequency of the applied alternating current was 100 mHz for the polymer deposition, while a frequency value of 50 mHz was used for the in situ electrodeposition of Ag and Au nanoparticles. The selected frequency values ensured the successful preparation of the composite materials. The use of readily available composite materials is intended to produce cost-effective analytical tools. The judicious modification of the organic conductive matrix by various metallic nanoparticles, such as Ag and Au, extends the potential applications of the sensing platform toward a range of biomolecules like quercetin and epinephrine, chosen as benchmark analytes for proof-of-concept antioxidant and neurotransmitter detection. The sensing platforms were tested successfully for quercetin and epinephrine determination on synthetic and real samples. Wide linear response ranges and low limit-of-detection values were obtained for epinephrine and quercetin detection., Competing Interests: The authors declare no conflicts of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of the data; in the writing of the manuscript; or in the decision to publish the results.

Association behavior between quinizarin (1,4-dihydroxyanthraquinone), an analogue of the chromophore of anthracycline anticancer drugs and sodium dodecyl sulfate (SDS) micelles in the presence of glucose, NaCl and urea additives was studied using absorption spectroscopy and conductometric techniques. The spectral results indicate an increase of binding constant and partition coefficient values in the presence of glucose and NaCl whereas the addition of urea leads to a decrease of binding strength and quinizarin partitioning into SDS micelles. Thus, the rise of NaCl and glucose concentrations is favorable for the quinizarin distribution into SDS micelles. From electrical conductivity measurements it was found that the critical micelle concentration (CMC) of SDS/quinizarin system decreases by adding NaCl and glucose whereas urea has not influence on the micelization process at the concentrations used in the present study. Since biologically compounds like glucose, NaCl and urea are found in the human body, the attained outcomes can be important in finding of effective drug delivery systems.

Liver cirrhosis is the consequence of chronicisation and of the evolution of untreated liver diseases. The complexity of the disease and the complications it can cause have been and are still intensively researched, aiming to discover new therapies or improve existing ones for the effective management of liver cirrhosis. Currently, the treatment used is directed against the cause that caused the disease, if it is known; in advanced cases, liver transplantation is the only valid therapeutic option. Hepatoprotectors that are currently on the market are numerous, having as common properties the antioxidant, anti-inflammatory, stabilizing properties of the hepatocytic membrane; A few examples: the ethanolic extract of Curcuma longa, the extract from the plant called Sophora flavescens, the extract of Glycyrrhiza glabra, silymarin (extracted from Sylibum marianum), the extract of Ganoderma lucidum, etc. Liver cirrhosis is accompanied by generalized hypovitaminosis, so supplementing the diet with hydro- and liposoluble vitamins is mandatory. Protein-caloric malnutrition can be prevented by a hyperprotein diet, especially beneficial being the supplementation with branched-chain amino acids, which are also applicable in the prophylaxis and treatment of hepatic encephalopathy. Nanoparticles are a state-of-the-art therapeutic option, proving increased bioavailability, for example polydopamine nanoparticles loaded with l-arginine have been tested as therapy in liver cirrhosis. Among the innovative treatment directions in liver cirrhosis are hybrid products (e.g. hybrid polymer nanoparticles loaded with caffeic acid), cell cultures and artificial or bioartificial liver support.

Background: Healthcare systems data (HSD) has the potential to optimise the efficiency of randomised controlled trials (RCTs), by decreasing trial-specific data demands. Therefore, the use of HSD in trials is expected to increase. In 2019, it was estimated that 47% of NIHR-funded trials were planning to use HSD. We aim to understand the extent and nature of its current use and its evolution over time., Methods: We identified a cohort of RCTs within the NIHR Journals Library that commenced after 2019 and were described as being in progress on 6 June 2022. Details on the source and use of HSD were extracted from eligible RCTs. The use of HSD was categorised according to whether it was used as the sole data source for outcomes and whether the outcomes were primary or secondary. HSD is often insufficient for patient-reported outcomes (PROs). We aimed to determine methods used by trialists for collecting PRO data alongside HSD., Results: Of the 84 eligible studies, 52 (62%) planned to use HSD and 79 (94%) planned to collect PROs. The number of RCTs planning to use HSD for at least one outcome was 28 (54%) with 24 of these planning to use HSD as the sole data source for at least one outcome. The number of studies planning to use HSD for primary and secondary outcomes was 10 (20%) and 21 (40%) respectively. The sources of HSD were National Health Service (NHS) Digital (n = 37, 79%), patient registries (n = 7, 29%), primary care (n = 5, 21%), The Office for National Statistics (ONS) (n = 3, 13%) and other (n = 2, 8%). PROs were collected for 92% of the trials planning to use HSD. Methods for collection of PROs included in-person (n = 26, 54%), online (n = 22, 46%), postal (n = 18, 38%), phone (n = 14, 29%) and app (n = 2, 4%)., Conclusions: HSD is being used in around two thirds of the studies but cannot yet be used to support PRO data collection within the cohort we examined. Comparison with an earlier cohort demonstrates an increase in the number of RCTs planning to use HSD., (© 2024. The Author(s).)

Background: Healthcare system data (HSD) are increasingly used in clinical trials, augmenting or replacing traditional methods of collecting outcome data. This study, PRIMORANT, set out to identify, in the UK context, issues to be considered before the decision to use HSD for outcome data in a clinical trial is finalised, a methodological question prioritised by the clinical trials community., Methods: The PRIMORANT study had three phases. First, an initial workshop was held to scope the issues faced by trialists when considering whether to use HSDs for trial outcomes. Second, a consultation exercise was undertaken with clinical trials unit (CTU) staff, trialists, methodologists, clinicians, funding panels and data providers. Third, a final discussion workshop was held, at which the results of the consultation were fed back, case studies presented, and issues considered in small breakout groups., Results: Key topics included in the consultation process were the validity of outcome data, timeliness of data capture, internal pilots, data-sharing, practical issues, and decision-making. A majority of consultation respondents (n = 78, 95%) considered the development of guidance for trialists to be feasible. Guidance was developed following the discussion workshop, for the five broad areas of terminology, feasibility, internal pilots, onward data sharing, and data archiving., Conclusions: We provide guidance to inform decisions about whether or not to use HSDs for outcomes, and if so, to assist trialists in working with registries and other HSD providers to improve the design and delivery of trials., (© 2024. The Author(s).)

Ferroelectricity in two-dimensional hybrid (2D) organic-inorganic perovskites (HOIPs) can be engineered by tuning the chemical composition of the organic or inorganic components to lower the structural symmetry and order-disorder phase change. Less efforts are made toward understanding how the direction of the polar axis is affected by the chemical structure, which directly impacts the anisotropic charge order and nonlinear optical response. To date, the reported ferroelectric 2D Dion-Jacobson (DJ) [PbI 4 ] 2- perovskites exhibit exclusively out-of-plane polarization. Here, we discover that the polar axis in ferroelectric 2D Dion-Jacobson (DJ) perovskites can be tuned from the out-of-plane (OOP) to the in-plane (IP) direction by substituting the iodide with bromide in the lead halide layer. The spatial symmetry of the nonlinear optical response in bromide and iodide DJ perovskites was probed by polarized second harmonic generation (SHG). Density functional theory calculations revealed that the switching of the polar axis, synonymous with the change in the orientation of the sum of the dipole moments (DMs) of organic cations, is caused by the conformation change of organic cations induced by halide substitution.

DNA thermal denaturation was evaluated as a measure of the effect of antitumor drug actinomycin D on the stability of the double helix and also the effect of SDS micelles on actinomycin D - DNA complexes. The results indicated that the melting temperature of DNA was dependent on drug concentration, increasing with actinomycin D concentration. High thermal stabilization (about 10 °C) of the DNA helix after the association with actinomycin D clearly demonstrates the intercalative binding mode. The presence of SDS micelles leads to the release of intercalated actinomcyin D molecules from DNA double helix and their further relocation in surfactant micelles. These results highlighted that the drug release can be controlled in time and by varying the concentration and nature of surfactant.

Aromatic hydrocarbons with fused benzene rings and regular triangular shapes, called n -triangulenes according to the number of rings on one edge, form groundstates with n -1 unpaired spins because of topological reasons. Here, we focus on methodological aspects emerging from the density functional theory (DFT) treatments of dimer models of the n = 2 triangulene (called also phenalenyl), observing that it poses interesting new problems to the issue of long-range corrections. Namely, the interaction comprises simultaneous spincoupling and van der Waals effects, i.e., a technical conjuncture not considered explicitly in the benchmarks calibrating long-range corrections for the DFT account of supramolecular systems. The academic side of considering dimer models for calculations and related analysis is well mirrored in experimental aspects, and synthetic literature revealed many compounds consisting of stacked phenalenyl cores, with intriguing properties, assignable to their long-range spin coupling. Thus, one may speculate that a thorough study assessing the performance of state-of-the-art DFT procedures has relevance for potential applications in spintronics based on organic compounds.

Phenalenyl is a triangular aromatic molecule made of three fused benzene rings, carrying an unpaired electron, and many of its derivatives show crystal structures with stacked radicals. Here, we investigate the inter-molecular binding in phenalenyl dimers by state-of-the-art computational methods and phenomenological models. Aside from being important for the supramolecular assembly of such radical molecules, the theoretical insight is relevant in methodological aspects, due to the interplay of long-range exchange coupling effects and van der Waals forces. We used comparative wave function-based and density functional theories. Drawing the potential energy surfaces as a function of inter-planar separation and mutual rotation of the monomer units, we found an interesting pattern which is not discovered in previous computational reports on the title systems. The dependence can be nicely interpreted by a transparent phenomenological model based on an orbital overlap paradigm of exchange coupling. We also brought forth a simplified phenomenological valence bond (VB) model of inter-molecular coupling, which is realized on the background of the VB spin model inside of the aromatic monomers and calibrated with the corresponding ab initio data. As the systems can be considered good candidates with potential applications in spintronics and organic magnetism, the theoretical rationalization opens up prospective ways to realize such promises.

Introduction: Birth hypoxia is a leading cause of perinatal mortality and neurological morbidity, resulting in central nervous system injury. Cerebral hypoxia and ischemia can produce a severe brain damage following a typical pattern, defined by selective vulnerability of the brain regions. The neonates are most prone to hypoxic-ischemic injuries due to the lack of efficient antioxidant defense. Neonatal hypoxia-ischemia (HI) in a 7-day-old rat HI model can produce cell death by apoptotic or necrotic mechanisms. The degree of apoptotic or necrotic mechanisms responsible for cell death in neonatal hypoxia-ischemia are not very clear as yet. The form of neuronal death may also depend on the severity of ischemic injury. Necrosis predominates in more severe cases, whereas apoptosis occurs in areas with milder ischemic injury. A human study demonstrated apoptotic and necrotic forms of cell death after hypoxic injury, whereas in some brains from stillbirths, only apoptotic figures were observed. The expression of activated caspase-3 reflects the role of apoptosis in neonatal hypoxic ischemic brain injury., Objectives: The aim of this study was to evaluate the possible neuroprotective effect of melatonin and hypothermia in hypoxic-ischemic encephalopathy in newborn rats. Local damages induced by hypoxia and ischemia were assessed by evaluating the changes in terms of histology and apoptosis., Methods: The experiment was conducted on 20 newborn Wistar rats premedicated for seven days with melatonin in a dose of 20 mg/kg/day. On the 7 th postnatal day (P7), the newborn rats were exposed to ischemia (by clamping the right carotid artery) and hypobaric hypoxia (8% O 2 for 90 minutes) and some groups to hypothermia., Results: In this experimental model of neonatal encephalopathy, melatonin, in a dose of 20 mg/kg/day has neuroprotective effect by reducing the number of cells expressing apoptosis in Cornu Ammonis (CA) (Ammon's Horn) CA1, CA2, CA3 and dentate gyrus of the hippocampus when combined with hypothermia., Conclusion: The results of this study prove that melatonin is protective in ischemic-hypoxic brain injuries, but the protection is conditioned in most of the brain regions (excepting cerebral cortex) by conjugation with post-injury hypothermia treatment.

Investigation of the interaction of quinizarin (Q), an analogue of the core unit of different anticancer drugs, with anionic SDS micelles has been performed by absorption and conductance measurements in 0.1 M phosphate buffer, pH 7.4 and over the temperature range of 298.15-323.15 K. The values of binding constant (Kb), partition coefficient (Kx) and the corresponding thermodynamic parameters (Gibbs free energy, enthalpy, entropy) for the binding and distribution of quinizarin between the bulk aqueous solution and surfactant micelles have been determined and discussed in terms of possible intermolecular interactions. Values of critical micelle concentration (CMC) and degree of ionization (?) for SDS in the absence and the presence of quinizarin have been evaluated from conductometric study. Comparing the absorption spectra of quinizarin in SDS micelles with the spectra in different solvents revealed that quinizarin molecules are located in the hydrophilic region of SDS micelles. The trend of changes in Gibbs free energy, enthalpy and entropy with temperature shows that both binding and partition processes are spontaneous and entropy driven. In addition, the hydrophobic interactions are the main forces involved in binding and partition processes.

Inflammation and oxidative stress are interrelated processes, during which many pathological processes lead to the reactive oxygen species (ROS) and the cytokines release. The aim of this experimental study was to analyse the effects of chlorogenic acid, in oral daily administration, against the oxidative stress and oedema development in experimental carrageenan-induced rat paw inflammation. The oxidative stress parameters were investigated after a paw inflammation was produced in rats that previoulsy received, for 14 days, either chlorogenic acid (100 mg/day or 150 mg/day) or indomethacin (1 mg/kg/day). The paw oedema was measured through plethysmometry made at 2, 6 and 24 hours after carrageenan injection. The oxidative stress was investigated through spectrophotometry. Blood samples, paw skin and kidneys were collected to investigate malondialdehyde (MDA), glutathione (GSH) and oxidized glutathione (GSSG). The protein expression of oxidative stress-related pathways was analysed in skin and kidneys through Western blot. The present study showed that indomethacin and both doses of chlorogenic acid, after 14 days of oral administration, exerted antioedematous effects during the inflammation development after carrageenan local injection. Compared to the group that received only carrageenan injection, significant decreases of the inflamed paw volume were shown in the treated groups (P < 0.001), in all inflammation phases. The lipid peroxidation was significantly decreased by both doses of chlorogenic acid in inflamed skin (P < 0.0001) and kidney (P < 0.0001). In serum, it was significantly inhibited by indomethacin (P < 0.01) and by 100 mg/day of chlorogenic acid (P < 0.05). The antioxidant protection, evaluated through the ratio GSH/GSSG, was significantly increased by chlorogenic acid in inflamed skin (P < 0.0001) and kidney (100 mg/day, P < 0.01; 150 mg/day, P < 0.0001). In serum, only indomethacin administration produced significant increases of the antioxidant protection (P < 0.05). Western blot analysis showed significant decreases of COX-2 in inflamed skin and kidney in the groups of rats that received indomethacin or 100 mg/day of chlorogenic acid. The effects of chlorogenic acid on NF-κB and pNF-κB were dose-dependent.

We revisit, in the key of structural chemistry, one of the most known and important drugs: the aspirin. Although apparently simple, the factors determining the molecular structure and supramolecular association in crystals are not trivial. We addressed the problem from experimental and theoretical sides, considering issues from X-ray measurements and results of first-principle reconstruction of molecule and lattices by ab initio calculations. Some puzzling problems can give headaches to specialists and intrigue the general public. Thus, the reported polymorphism of aspirin is disputed, a so-called form II being alleged as a result of misinterpretation. At the same time, were presented evidences that the structure of common form I can be disrupted by domains where the regular packing is changed to the pattern of form II. The problems appear even at the level of independent molecule: the most stable conformation computed by various techniques of electronic structure differs from those encountered in crystals. Because the energy difference between the related conformational isomers (computed as most stable vs. the experimental structure) is small, about 1 kcal/mol, comprised in the error bars of used methods, the unresting question is whether the modelling is imprecise, or the supramolecular factors are mutating the conformational preferences. By a detective following of the issue, the intermolecular effects were made responsible for the conformation of the molecule in crystal. The presented problems were gathered from literature results, debates, glued with modelling and analysis redone by ourselves, in order to secure the unitary view of the considered prototypic topic., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Deriving a practical formula for the atomic body with generalized shell occupations, we perform a detective analysis of the radial distribution in the exchange energy, hinting at ideas about new types of density functionals, dedicated to the specifics of the electronic structure of atoms, exploiting the intrinsic spherical symmetry.

Nitroxide-based radicals, having the advantage of firm chemical stability, are usable as probes in the detection of nanoscale details in the chemical environment of various multi-component systems, based on subtle variations in their electron paramagnetic resonance spectra. We propose a systematic walk through the vast area of problems and inquires that are implied by the rationalization of solvent effects on the spectral parameters, by first-principle methods of structural chemistry. Our approach consists of using state-of-the-art procedures, like Density Functional Theory (DFT), on properly designed systems, kept at the border of idealization and chemical realism. Thus, we investigate the case of real solvent molecules intervening in different configurations between two radical molecules, in comparison with radicals taken in vacuum or having the solvent that is treated by surrogate models, such as polarization continuum approximation. In this work, we selected the dichloromethane as solvent and the prototype radicals abbreviated TEMPO ((2,2,6,6-Tetramethylpiperidin-1-yl) oxyl). In another branch of the work, we check the interaction of radicals with large toroidal molecules, β-cyclodextrin, and cucurbit[6]uril, modeling the interaction energy profile at encapsulation. The drawn synoptic view offers valuable rationales for understanding spectroscopy and energetics of nitroxide radicals in various environments, which are specific to soft chemistry.

In vitro studies showed that high-frequency pulsed electromagnetic fields (HF-PEMFs) increase the activity/expression of early and late osteogenic markers and enhance bone mineralization. The main aim of this study was to investigate the in vivo effects of HF-PEMFs on fracture healing using a rat model. A femur fracture was established by surgery in 20 male Wistar rats. Titanium nails were implanted to reduce and stabilize the fracture. After surgery, 20 rats were equally divided into untreated control and treated group (from the first postoperative day HF-PEMFs at 400 pulses/sec [pps] were applied for 10 minutes/day, for two weeks). Quantitative and qualitative assessment of bone formation was made at two and eight weeks following surgery and included morphological and histological analysis, serological analysis by ELISA, micro-computed tomography (micro-CT), and three-point bending test. At two weeks in HF-PEMF group, soft callus was at a more advanced fibrocartilaginous stage and the bone volume/total tissue volume (BV/TV) ratio in the callus area was significantly higher compared to control group (p = 0.047). Serum concentration of alkaline phosphatase (ALP) and osteocalcin (OC) was significantly higher in HF-PEMF group (ALP p = 0.026, OC p = 0.006) as well as the mechanical strength of femurs (p = 0.03). At eight weeks, femurs from HF-PEMF group had a completely formed woven bone with dense trabeculae, active bone marrow, and had a significantly higher BV/TV ratio compared to control (p = 0.01). HF-PEMFs applied from the first postoperative day, 10 minutes/day for two weeks, enhance bone consolidation in rats, especially in the early phase of fracture healing.

It is proposed that at the commercial flight altitude the cosmic radiation affects the human body and induces the oxidative stress. This review presents data to support this idea and also cumulates the information to provide the basis for antioxidant supplementation in persons that travel by plane at high altitudes. The conclusion is that the heterogeneity of cosmic radiation can produce different effects on human body through different mechanisms and the prophylactic treatment with antioxidants can reduce the oxidative stress generated by the radiation exposure.

The focus of the present work was to investigate the interaction of the anticancer drug mitoxantrone with two bile salts, sodium taurodeoxycholate (NaTDC) and sodium taurocholate (NaTC). Ultraviolet-visible (UV-Vis) absorption and electron paramagnetic resonance (EPR) spectroscopy were used to quantify the interaction and to obtain information on the location of mitoxantrone in bile salt micelles. The presence of submicellar concentrations of both bile salts induces mitoxantrone aggregation and the extent of drug aggregation in NaTDC is higher than in NaTC. For micellar bile salts concentrations, mitoxantrone monomers are entrapped in the micellar core. Binding constants, micelle/water partition coefficients and the corresponding thermodynamic parameters for binding and partitioning processes were estimated using the changes in monomer absorbance in the presence of bile salts. Binding interaction of mitoxantrone is stronger for NaTDC than NaTC micelles, whereas partitioning efficiency is higher for NaTC micelles for all investigated temperatures. Thermodynamic parameters indicate that both binding and partitioning processes are spontaneous and entropy controlled. The spectral behavior and thermodynamic parameters indicate distinct types of mitoxantrone interaction with NaTDC and NaTC micelles supported by the differences in nature and structure of bile salts micelles., Competing Interests: The authors declare no conflict of interest.

Mitoxantrone is a synthetic anticancer drug used clinically in the treatment of different types of cancer. It was developed as a doxorubicin analogue in a program to find drugs with improved antitumor activity and decreased cardiotoxicity compared with the anthracyclines. As the cell membrane is the first barrier encountered by anticancer drugs before reaching the DNA sites inside the cells and as surfactant micelles are known as simple model systems for biological membranes, the drugs-surfactant interaction has been the subject of great research interest. Further, quantitative understanding of the interactions of drugs with biomimicking structures like surfactant micelles may provide helpful information for the control of physicochemical properties and bioactivities of encapsulated drugs in order to design better delivery systems with possible biomedical applications. The present review describes the physicochemical aspects of the interactions between the anticancer drug mitoxantrone and different surfactants. Mitoxantrone-micelle binding constants, partitions coefficient of the drug between aqueous and micellar phases and the corresponding Gibbs free energy for the above processes, and the probable location of drug molecules in the micelles are discussed.

Introduction: Cerebral hypoxia and ischemia are the major causes of perinatal mortality resulting in central nervous system injury. Hypoxia and ischemia produce massive brain damage and one of the most important mechanisms in the lesion pattern is oxidative stress., Aims: The objectives of this study are to assess the effects of resveratrol pretreatment in a cerebral hypoxic-ischemic (HI) newborn rat model as well as the influence that hypothermia has on redox parameters in this experimental model and the effects of the combined therapy from the oxidative stress perspective., Material and Method: The experiment was performed on eighty newborn Wistar rats of both genders, weighing about 10 grams, placed into eight groups: control, treated with resveratrol (RES), RES+HI insult, RES+hypothermia, subjected to hypothermia only, HI insult+normothermia, HI insult+hypothermia. Resveratrol was administrated in a dose of 20 mg/kg/day for seven days as premedication. At the end of this period the animals were exposed to hypobaric hypoxia (9% O(2+) for 90 minutes) and ischemia (by clamping the right carotid artery). In order to test the effect of combined therapy of resveratrol with hypothermia, several animals were exposed after HI injury to whole body moderate hypothermia (with 4°C) for 3h. After recovery the malondialdehyde level and the activities of superoxide dismutase and glutathione peroxidase were determined in the brain tissue of the newborn rats., Results: MDA levels were increased in the groups receiving resveratrol pretreatment. In the group subjected to simple hypothermia MDA levels were also increased. In the group subjected to HI insult and then to hypothermia, MDA levels were significantly lower. MDA levels were lower also in the group where RES was associated with hypothermia in HI insult context. GPx levels were decreased in groups pretreated with RES and subjected to HI, hypothermia, the same effect in case of hypothermia alone. Only in the group treated with RES was the GPx level higher than in controls. SOD levels were high in the RES pretreated group, but decreased in HI insult. In the group subjected to hypothermia after HI, SOD was significantly higher., Conclusion: The results of this study prove that hypothermia offers better neuroprotection in ischemic brain injuries than resveratrol. The combined therapy influenced the oxidative stress parameters. Hypothermia is a stress factor, but when applied in post-lesion condition, offers protection for the brain.

Second harmonic generation (SHG) investigations on alpha-CN-terthiophene-thiolate-covered GaAs(110) electrodes in 1 N H2SO4 solution revealed significant changes in the rotational anisotropy of the SH response. The enhancement of the 1- and the 3-fold contributions around -250 mV suggests changes in the symmetry properties of the delocalized electron system due to an alteration of the adsorption geometry induced by the applied potentials. The analysis of the EIS data showed that in the potential region where the SH signal exhibits the more important changes the Mott-Schottky plot undergoes a pronounced shift to more negative potentials as a result of the charging of the surface states grouped about 1.06 eV below the conduction band edge. Semiempirical MO calculations suggest that the most energetically favorable interaction implies electron transfer from the semiconductor conduction band to the lowest unoccupied molecular orbital of the organic molecule with epsilon(LUMO)=-1.707 eV. Such a chemisorption bond bringing the organic molecule to a quasi-planar position is well supported by the major changes in the XPS spectra of the electrochemically biased samples with respect to the as-prepared ones. Two distinct N 1s species instead of one and a shift of 1.6 eV to higher BE of the terthiophene S 2s core level are strong evidence for a potential-induced change in the adsorption geometry. Taking into account that the acceptor-like surface state group located close to the semiconductor valence edge (EC,S=-1.06 eV) may correspond to the LUMO level (shifted downward by the adsorption process), we assume that the organic molecule, initially adsorbed by the thiolate end, undergoes a conformational change from a tilted to an almost flat position when the applied potential brings the semiconductor Fermi level into its neighborhood. This assumption is in a very good agreement with the potential-induced variation in the thiol thickness estimated from the thiol capacitance.

Spin correlations in the paramagnetic phase of La(2)CuO(4) have been studied using polarized neutron scattering, with two important results. First, the temperature dependence of the characteristic energy scale of the fluctuations and the amplitude of the neutron structure factor are shown to be in quantitative agreement with the predictions of the quantum nonlinear sigma model. Second, a comparison of a high-temperature series expansion of the equal-time spin correlations with the diffuse neutron intensity provides definitive experimental evidence for ring exchange.