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A series of real and hypothetical polymers with a high content of –C(O)O– groups in the main chain was studied by ab-initio calculations. Carbon polymers with increasing levels of oxidation are normally correlated with higher tendencies toward environmental- and biodegradability. The ultimate oxidized polymer in this group is the hypothetical polymeric carbon dioxide. Results of the relatively inexpensive computational approach were consistent with experimental results and previous observations. The evaluation of free energies indicates trends in the effect of structural changes on stability as well as possible limitations. Several approaches to increasing the stability of highly oxidized carbon polymers are proposed.

Diamond-like carbon (DLC) protective films have received considerable attention in recent years. Beside tools and dies, diamond-like and related coatings are starting to find application in some highly stressed mechanical components, including bearings and gears. Several different gear tests show an increase in carrying load capacity or prolonged lifetime with tungsten carbide-doped DLC (W-DLC)-coated gears. The lubricants have been mostly commercially available gear oils that were primarily developed or tailored for ferrous materials and are probably far from optimal for amorphous W-DLC layers. In the present work, the influence of lubricant chemistry on the friction and wear in W-DLC-coated contacts was investigated using a reciprocating test device. The first six test lubricants were conventional non-inhibited API/ATIEL base stocks followed by selected test blends in combination with different surface-active single additives. Experimental results in coated contact have shown that for friction reduction performance, additives are not necessary, while wear resistance is related with the chemistry of the lubricant. It may be concluded at this stage that different mechanisms of friction-induced interaction between lubricants and W-DLC-coated layers are possible.

It was recently shown that the plasma protein-mediated attractive interaction between phospholipid membranes could in the budding process cause adhesion of the bud to the mother membrane [J. Urbanija, N. Tomsic, M. Lokar, A. Ambrozic, S. Cucnik, M. Kanduser, B. Rozman, A. Iglic, V. Kralj-Iglic, Coalescence of phospholipid membranes as a possible origin of anticoagulant effect of serum proteins, Chem. Phys. Lipids 150 (2007) 49-57]. Since in the in vivo conditions the budding of cell membranes leads to the release of microvesicles into the circulation, a hypothesis was put forward that the ability of plasma to cause adhesion between membranes supresses the microvesiculation process. In the present work, this hypothesis was tested in a population of 19 patients with gastrointestinal diseases. The number of microvesicles in peripheral blood of patients was determined by flow cytometry while the ability of plasma to cause adhesion between membranes was determined by adding patient's plasma to the suspension of giant phospholipid vesicles created by electroformation method, and measuring the average effective angle of contact between the adhered vesicles. Statistically significant negative correlations between the number of microvesicles and the average effective angle of contact (Pearson coefficient -0.50, p=0.031) and between the number of microvesicles per number of platelets and the average effective angle of contact (Pearson coefficient -0.64, p=0.003) were found, which is in favor of the above hypothesis. Patients with gastrointestinal cancer had larger number of microvesicles (difference 140%, statistical significance 0.033) and smaller average effective angle of contact (difference 20%, statistical significance 0.013) compared to patients with other gastrointestinal diseases.

Microvesicles (MVs) found in peripheral blood are derived from the budding of cell membranes and are associated with a higher risk of thrombosis. Recently, a hypothesis has been suggested that certain plasma proteins could suppress microvesiculation by mediating adhesion of the buds to the mother cell membrane. In a pilot study, we have tested this hypothesis by considering the relation between the amount of MVs in peripheral blood and the ability of plasma to induce adhesion between giant phospholipid vesicles (GPVs). MVs were isolated from human plasma and counted by flow cytometry. The adhesion between GPVs was measured by assessing the average angle of contact between the adhered vesicles. It was found that greater ability of plasma to induce adhesion relates to smaller concentration of MVs in plasma. The ratio between the concentration of MVs and the concentration of platelets proved the most efficient parameter to predict the propensity of the membrane to shed vesicles. Our results indicate that a stronger attractive interaction between GPVs mediated by plasma is associated with a smaller amount of MVs per platelets. Plasma that mediates stronger attractive interaction between GPVs might potentially be associated with a smaller risk of thrombosis.

Liquefied wood (LW) prepared in a microwave process was applied as a novel; inexpensive precursor feedstock for incorporation of (R)-3-hydroxyvalerate (3HV) into polyhydroxyalkanoate (PHA) biopolyesters in order to improve the biopolyester's material quality; Cupriavidus necator was applied as microbial production strain. For proof of concept, pre-experiments were carried out on a shake flask scale using different mixtures of glucose and LW as carbon source. The results indicate that LW definitely acts as a 3HV precursor, but, at the same time, displays toxic effects on C. necator at concentrations exceeding 10 g/L. Based on these findings, PHA biosynthesis under controlled conditions was performed using a fed-batch feeding regime on a bioreactor scale. As major outcome, a poly(3HB-co-0.8%-3HV) copolyester was obtained displaying a desired high molar mass of M-w = 5.39 x 10(5) g/mol at low molar-mass dispersity (D-M of 1.53), a degree of crystallinity (X-c) of 62.1%, and melting temperature T-m (176.3 degrees C) slightly lower than values reported for poly([R]-3-hydroxybutyrate) (PHB) homopolyester produced by C. necator; thus, the produced biopolyester is expected to be more suitable for polymer processing purposes.

The impairment of brachial plexus (IBP) in the neonate and infant remains an important problem. Risk factors for IBP are well known, but the mechanisms of impairment are not yet fully understood. It is important to identify early signs of IBP and to evaluate the hand function. In the guidelines we propose to use the Toronto scale for evaluation of hand function. The newborn with IBP should be referred to physiotherapy, and then regularly followed-up once a month. If the arm and hand function, especially flexion of the elbow, is not improving at the age of two months, the infant should be referred to the tertiary level rehabilitation centre and to department for plastic surgery at the University Medical Centre in Ljubljana. When necessary, the reconstructive procedure should be done by the age of three to six months. After reconstruction of brachial plexus, the child needs a comprehensive therapy program, which involves passive stretching, sensory stimulation, exercises to promote the development of active voluntary movements, bimanual activities, and symmetrical posture and movement patterns.

The discovery of cannabinoid receptors and endocannabinoid system has led to the potential therapeutic use of cannabis derivatives. Cannabinoids acting through the CB1 receptors modulate the release of other neurotransmitters in central nervous system, whereas the activation of peripheral CB2 receptors results in decreased inflammatory response and increased apoptosis of some tumor cells populations. The cannabinoids have been authorized for chemotherapy-induced nausea and vomiting; stimulation of appetite; to alleviate neuropathic pain and spasticity in multiple sclerosis, and to reduce pain in cancer patients. Efficacy in other diseases and clinical conditions should be proven in ongoing or future clinical trials. Isolation and identification of different cannabinoids from cannabis and synthesis of novel, more selective, derivatives widens their therapeutic potential. However, there are numerous adverse effects reported, especially when cannabinoids formulations with unknown quantitative and qualitative composition are used. Addiction, tolerance, withdrawal symptoms, increased risk of acute myocardial re-infarction, and increased risk of psychosis or worsening of psychosis are the most common adverse effects of cannabinoids. Acute adverse effects e. g. severe central nervous system depression, are more pronounced in children than in adults. Potential cannabinoid medicines should be subject to the same regulations as other potential drugs. Safety and efficacy of any potential drug candidate, regardless whether it is plant-derived or synthesized, should be proven in non-clinical studies and clinical trials, as well as the marketing authorization must be issued by the appropriate drug authority. Patients deserve a quality manufactured product, which always contains the specified amount of "Remedium cardinale."

Background: In this article, a facial reconstruction with implant-supported craniofacial epitheses and our clinical experience with the substitution of auricular and orbital region are described. Materials and methods: In this case series, 9 patients with 28 endosseous implants performed in the period between 2006 and 2013 were included. Two-stage and one-stage procedures were opted for; the former in six patients, and the latter in three patients. There were four patients with congenital defects of facial structures, and five patients who had undergone ablative oncological surgery; three among them received postoperative radiotherapy. In two patients adjuvant therapy with hyperbaric oxygen was used before and after implantation. We analysed the success of combined surgical-prosthodontic treatment. Results: We placed 28 titanium implants in 9 patients. A successful osseointegration was observed in 27 implants; only one endosseous implant failed to integrate and fell out of the bone (in an irradiated patient). The final implantsupported epithesis was achieved in six patients. Among them there were five ear-substituting epitheses and one epithesis substituting the eye and periorbital region. The final epithesis could not be made in three patients; in one patient too much keloid formed to fix a prosthodontic bar to the implants, the other two patients died because of the progression of malignancy. Conclusion: The surgical technique for rehabilitation using implant-supported facial epitheses is simple and reliable. In certain indications, it is the only proper option for aesthetic and socially acceptable rehabilitation. The major problem remains soft tissues surrounding the implants. Due to their stability and appearance, the implantsupported epitheses are superior to the adhesiveretained epitheses. Odkritje receptorjev za derivate iz konoplje in endokanabinoidnega sistema je privedlo do številnih možnosti za terapevtsko uporabo kanabinoidov. V osrednjem živčevju kanabinoidi učinkujejo predvsem modulatorno, uravnavajo sproščanje drugih nevrotransmitorjev prek aktivacije receptorjev CB1. Aktivacija receptorjev CB2 zunaj osrednjega živčevja povzroča zmanjšanje vnetnega odgovora in povečanje apoptoze nekaterih tumorskih celic. S kanabinoidi lahko zdravimo slabost in bruhanje, izzvano s citostatiki; stimuliramo apetit; blažimo nevropatsko bolečino in spastičnost pri multipli sklerozi ter bolečino pri bolnikih z rakom. Učinkovitost pri drugih boleznih in stanjih se še preverja. Izolacija in identifikacija posameznih kanabinoidov iz konoplje in sinteza bolj selektivnih derivatov povečuje terapevtske možnosti. Ob tem se pojavljajo številni problemi z neželenimi učinki, zlasti, kadar gre za uporabo pripravkov iz konoplje z neznano količinsko in kakovostno sestavo. Med toksičnimi učinki kanabinoidov so najbolj zaskrbljujoči kronični učinki, kot so odvisnost, toleranca z odtegnitvenimi simptomi, povečano tveganje za ponovni akutni miokardni infarkt in povečano tveganje za razvoj psihoz oziroma poslabšanje simptomov pri že obstoječi psihozi. Akutni učinki so bolj izraženi pri otrocih, pri katerih je bila pri naključnem zaužitju opažena huda depresija osrednjega živčevja. Za potencialna zdravila iz konoplje in sintetične kanabinoide morajo veljati enaka pravila kot za druga potencialna zdravila. Tudi če je snov naravnega (rastlinskega) izvora in ima biološke učinke, moramo uporabnost za zdravljenje in sprejemljivo varnost za bolnika dokazati v nekliničnih preizkušanjih in kliničnih študijah, dovoljenje za promet pa mora izdati ustrezen organ. Bolniki pa si zaslužijo tudi kakovostno izdelana zdravila, ki vedno vsebujejo predpisano količino t. i. "remedii cardinalis".

The structural performance of historical masonry elements can be understood provided the following factors are known: geometry; the characteristics of its masonry texture and morphology, state of damage and decay, physical, chemical and mechanical characteristics of the components (units, infill, mortar); the characteristics of built masonry as a composite material. In order to quantify the mechanical properties of the masonry both laboratory and in-situ tests are required. However, in the case of cultural heritage assets, the setting up of an effective knowledge procedure is strictly related to the minimization of invasiveness on the structure, with the aim of its conservation, rather than the cost–benefit optimization: thus it is essential to have available reference parameters to be adopted for different masonry types. Within this context, this State-of-the-Art paper on this topic is organized with integrated outcomes from the test campaigns carried out through the PERPETUATE project, that are also briefly presented. Reference parameters for effective seismic assessment are provided both for brick and stone masonry together with their upper and lower bound values for both mechanical parameters and damage limits for which proper limit states (LS) may be associated. Apart from the LS for structural elements (SE), the relevant LS’s for artistic assets attached to the SE are also presented in this paper.

The impairment of the brachial plexus (IBP) in neonates and infants remains an important problem. Risk factors for IBP are well known, but the mechanisms of impairment are not yet fully understood. It is important to identify early signs of IBP and to evaluate the hand function. In the guidelines we propose to use the Toronto scale for the evaluation of hand function. The newborn with IBP should be referred to physiotherapy, and then regularly followed-up once a month. If the arm and hand function, especially flexion of the elbow, is not improving at the age of two months, the infant should be referred to the tertiary level rehabilitation centre and to the department for plastic surgery at the University Medical Centre in Ljubljana. When necessary, the reconstructive procedure should be done by the age of three to six months. After reconstruction of the brachial plexus, the child needs a comprehensive therapy program, which involves passive stretching, sensory stimulation, exercises to promote the development of active voluntary movements, bimanual activities, and symmetrical posture and movement patterns. Okvara brahialnega pleteža (OBP) pri novorojenčku in dojenčku tudi v sodobnem času ostaja pomemben problem. Dejavniki tveganja za OBP so poznani, mehanizmi nastanka okvare pa še niso povsem pojasnjeni. V procesu obravnave novorojenčka in dojenčka z OBP je pomembno zgodnje prepoznavanje znakov okvare in natančna ocena funkcije roke. V predlogu smernic za oceno funkcije roke na novo predlagamo uporabo Torontske lestvice. Po ugotovitvi OBP je novorojenčka potrebno vključiti v program fizioterapije, nato pa redno spremljati popravljanje klinične slike in izboljševanje funkcije roke. Oceno je potrebno ponoviti enkrat mesečno. Če se funkcija roke, predvsem pa krčenje v komolcu ne popravlja, je dojenčka v starosti dveh mesecev potrebno napotiti na Univerzitetni rehabilitacijski inštitut RS Soča in konzilij za brahialni pletež na Univerzitetnem kliničnem centru v Ljubljani ter morda opraviti rekonstrukcijski poseg v starosti od treh do šestih mesecev. Po operaciji otrok potrebuje celostno habilitacijsko obravnavo, ki vključuje pasivno razgibavanje, spodbujanje razvoja občutenja različnih dražljajev, vaje za spodbujanje razvoja aktivnih hotenih gibov, soročnih aktivnosti, simetrične drže in gibanja.

Microwave radiation was used as the sole heating source to achieve liquefaction of Central European hardwoods, with glycols and organic acid anhydrides, using phosphoric acid as the acid catalyst. Pulsed microwaves of 300–700 W power were applied for 5–20 min. The efficiency of liquefaction increased with higher microwave power, longer radiation time, and higher phosphoric acid addition. With minor amounts of added acid it was possible to achieve complete liquefaction in 20 min. The method was tested for different hardwood types, with a series of glycols and anhydrides, and was found to be generally applicable. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101:1051–1056, 2006

Universal tractor transmission oil (UTTO) is multipurpose tractor oil formulated for use in transmissions, final drives, wet brakes and hydraulic systems of tractors employing a common oil reservoir. In the present work, the results of a series of tests performed to evaluate vegetable based oils are presented. Tribological properties of formulated rapeseed and high oleic sunflower based UTTO were investigated in the standard and non-standard test procedures and compared with the properties of commercially available synthetic and mineral UTTO. Performances of test oils were demonstrated by using SRV high frequency test device, four-ball test rig, and FZG spur gear test rig. For final tests a laboratory hydraulic system and a spur gear test rig were used.

Polyamide-6 was exposed as the sole nitrogen source to the filamentous fungus Phanerochaete chrysosporium under submerged cultivation conditions. Preliminary results are very encouraging. The fungus attached itself to polymer fibres, continued growing, and slowly degraded them. After three months the polymer's molar mass was reduced by 50%, as seen from viscosity measurements. The thermal properties of PA-6 fibres were studied by differential scanning calorimetry, which showed degradation-induced changes of the melting temperatures and enthalpies of fusion indicating a decreasing degree of crystallinity with longer incubation time. Physical degradation was observed by scanning electron microscopy. Degradation was seen as horizontal grooves in the fibres and was continued over a five months period after which the fibres lost most of their physical strength and readily fragmented.

Polyamide-6 (PA-6) is a widely used polycondensation polymer that can be recycled by hydrolysis to its monomer ϵ-caprolactam. The reaction is normally catalyzed by mineral acids. Using microwaves as the source of heating, zinc chloride, acetate and triflate were evaluated as non-acid catalysts for the reaction. Gravimetric and electron spray ionization mass spectrometry analysis of reaction products showed ZnCl2 as the most effective salt catalyst. A 50wt% (versus PA-6) addition gave 75% water-soluble, low-molecular-weight oligomers, which is approximately 25% lower than when using phosphoric acid. The triflate salt was effective only when used as an addition to a mineral acid, whereas the acetate was ineffective. FTIR and NMR spectroscopy of degradation products showed that dissociated ions from ZnCl2 bind to the amide group of the polymer. Using the triflate salt no such interaction could be observed, indicating that the degradation and catalysis mechanisms differ with the chloride and triflate salt. Five water-stable lanthanide triflates showed no catalytic effect on the reaction. Copyright © 2003 John Wiley & Sons, Ltd.

The cyclic dimer of e-caprolactam (C2) is a very stable compound as indicated by its high melting point (347 °C), low solubility in most solvents, and relatively low reactivity toward hydrolysis. FTIR measurements in solid state confirmed the existence of hydrogen bonds between NH protons and CO groups. Upon heating to 200 °C these bonds are not broken, but are merely weakened. This is shown by shifts of the NH stretching band toward higher wave numbers as well as by shifts of other characteristic bands. Temperature controlled NMR measurements on 0.3 and 30% C2 solutions in formic acid gave temperature coefficients of NH proton signals of −0.006 and −0.009 ppm/K, respectively, strongly indicating intermolecular hydrogen bonding. In the same concentration range signals for NH protons and CO carbons were shifted toward higher fields with higher C2 concentration. Using density functional theory (DFT) calculations it was not possible to successfully perform geometry optimization on any C2 structure with intramolecular hydrogen bonds. The trans form of C2 was found to be 7.0 kcal/mol lower in energy than the cis form. Symmetrical structures of C2 based on published trans X-ray structures were found to have comparable energies. Hydrogen bonds between trans C2 and discrete molecules of formic acid, water and N-methylacetamide, as model for solvents and a neighboring C2 molecule, were found to be comparable in energy. Full geometry optimization of a dimer of trans C2 gave energy stabilization of 8.25 kcal/mol per H-bond. These results show C2-C2 polar interactions to be comparable with polar interactions of C2 with solvents. The stability of C2, however, cannot be explained only by hydrogen bonding. It is likely that nonpolar interactions between C2 molecules complement the stabilization by hydrogen bonding. Optimized dimer of two trans cyclic-e-caprolactam-dimer molecules (Etot = −1 461.0682582 H).

An ab initio and DFT treatment of the nitroso-naphthol/quinone-monooxime tautomeric equilibrium revealed that the proton transfer process within the intramolecular hydrogen bond cannot be responsible for the observed doubling of NMR signals. Our analysis demonstrates that the barrier associated with geometric isomerization of the CN bond is the likely cause of the signal doubling phenomenon. The conclusion of our study would suggest the need for re-interpretation of the dynamics in tautomeric equilibria of this type.

Electron density at the carbon atom is a significant factor determining the stability of molecules, but it is difficult to quantify. Using the Atoms in Molecules (AIM) quantum theory, we calculated the atomic charges and volumes of carbon atoms in highly oxidized compounds. The two parameters are shown to be good quantitative descriptors of electron depletion and can be used as an indicator for stability/reactivity of such compounds.

In astrocytes, nerve growth factor (NGF) synthesis and secretion is stimulated by the cytokine interleukin-1 beta (IL-1 beta). In the present study, the role of IL-1 receptor binding sites in the regulation of NGF release was evaluated by determining the pharmacological properties of astroglially localized IL-1 receptors, and, by comparing the effects of both the agonists (IL-1 alpha and IL-1 beta) and the antagonist (IL-1ra)-members of the IL-1 family on NGF secretion from rat neonatal cortical astrocytes in primary culture. Using receptor-binding studies, binding of [(125)I] IL-1 beta to cultured astrocytes was saturable and of high affinity. Mean values for the K(D) and B(max) were calculated to be 60.7+/-7.4 pM and 2.5+/-0.1 fmol mg(-1) protein, respectively. The binding was rapid and readily reversible. IL-1 receptor agonists IL-1 alpha (K(i) of 341.1 pM) and IL-1 beta (K(i) 59.9 pM), as well as the antagonist IL-1ra (K(i) 257.6 pM), displaced specific [(125)I] IL-1 beta binding from cultured astrocytes in a monophasic manner. Anti-IL-1RI antibody completely blocked specific [(125)I] IL-1 beta binding while anti-IL-1RII antibody had no inhibitory effect. Exposure of cultured astrocytes to IL-1 alpha and IL-1 beta revealed the functional difference between the agonists in influencing NGF release. In contrast to IL-1 beta (10 U/ml), which caused a 3-fold increase in NGF secretion compared to control cells, IL-1 alpha by itself had no stimulatory action on NGF release. The simultaneous application of IL-1 alpha and IL-1 beta elicited no additive response. IL-1ra had no effect on basal NGF release but dose-dependently inhibited the stimulatory response induced by IL-1 beta. We concluded that IL-1 beta-induced NGF secretion from cultured rat cortical astrocytes is mediated by functional type I IL-1 receptors, whereas IL-1 alpha and IL-1ra, in spite of their affinity for IL-1RI, have no effect on NGF secretion from these cells. Type II IL-1R is not present on rat neonatal cortical astrocytes.

Analysis of linear and cyclic polyamide-6 (PA-6) oligomer mixtures is an often needed task, that requires expensive equipment and/or chemicals or involved chemical procedures. We present an analytical method using electrospray ionization-mass spectrometry (ESI-MS) that has none of the mentioned difficulties. Measurements were performed on simple acidic aqueous solutions of oligomers. The method allowed qualitative and quantitative characterization of cyclic and linear oligomers up to octamer. Scanning for both the positive, as well as negative ion fragments was used. Signal vs. concentration responses were determined for a number of lower oligomers. The method has the advantage of short analysis times and the use of relatively accessible instrumentation.

The nitrosophenol/quinone monooxime tautomeric equilibrium was studied by ab initio MO calculations using the Hartree–Fock method at the 6-31G and 6-31G∗ levels of theory. The 13 examined structures were based on benzene, naphthalene and phenanthrene ring systems with ortho and para substitution patterns of nitroso and hydroxy groups. Results show that the quinonoid form becomes increasingly favored with increasing ring system size. For 2-nitrosophenol and 1-nitroso-2-naphthol the phenolic forms are more stable by 10.3 and 0.5 kcal/mol, respectively, but for 9,10-nitrosophenanthrol the quinonoid form is more stable by 4.6 kcal/mol. Also, with larger ring systems the geometries of both tautomeric forms become increasingly similar. The most stable ortho structures possess an intramolecular H-bond that appears to be stronger in quinonoid forms. Results of the calculations are accordant with experimental data.

The use of microwave irradiation as the source of heating in glycolysis of waste poly(ethylene terephthalate) (PET) was investigated and shown to achieve complete PET solubilization in approx. 5 min. The reaction in diethylene glycol and propylene glycol was monitored in terms of temperature and pressure. Other glycols were also used as solvolysis reagents and a number of basic inorganic compounds were examined as potential catalysts. Their effectiveness was evaluated on the basis of irradiation time needed for PET solubilization and gel permeation chromatography analyses of reaction products. The effect of the amount of catalyst used was investigated for the case of zinc(II) acetate and showed a limited effect on the ratio of characterized products. Copyright © 1999 John Wiley & Sons, Ltd.