Search results for "MOLA"
showing 10 items of 1216 documents
Phase equilibria and interfacial tension between coexisting phases for the system water/2-propanol/poly(acrylic acid)
1995
The cloud point curve, tie-lines and interfacial tensions were measured for solutions of 50 mol-% neutralized (counter-ion Na ○+ ) poly(acrylic acid) (molar mass M w = 9 700 g/mol; polydispersity index M w /M n = 2,0) in the mixed solvent water/2-propanol at 30°C. Due to the non-uniformity of the polymer, the end-points of the tie-lines are not situated on the cloud-point curve. The interfacial tension σ, determined by means of the spinning drop method, increases in sigmoidal manner with R tl , the length of the tie-line, expressed in terms of weight fractions. An evaluation of these data in a double-logarithmic plot of σ.M -0,5 versus R tl yields a critical exponent of 4,23 as compared wit…
Apparent Molar Mass of a Polyelectrolyte in an Organic Solvent in the Low Ionic Strength Limit As Revealed by Light Scattering
2013
The apparent molar mass of a partially quaternized poly-2-vinylpyridines (degree of quaternization 4.3% < Q < 35%) in 1-propanol is measured by light scattering at low ionic strength (10–6 M < cs < 10–3 M) as a function of polyion repeat unit concentration (7 × 10–5 monomol/L < cm,p < 4 × 10–2 monomol/L). No dialysis was applied prior to measurements. The apparent molar mass under “salt-free” conditions is smaller than the true molar mass by an order of magnitude, while approaching the true value at higher ionic strength. Concomitant data on the dependence of scattering intensity on scattering wave vector show that the dilute polyelectrolyte solutions are strongly correlated. A recent theor…
Characterization of lignin dissolved during alkaline pretreatment of softwood and hardwood
2015
Various alkaline pretreatments were applied to Scots pine (Pinus sylvestris) and silver/white birch (Betula pendula/pubescens) wood chips and the characterization of sulfur-free lignin dissolved was performed. The behavior of lignin during these pretreatments (alkali charge 1–8% NaOH, time 30–120 minutes, and temperature 130–150°C) was studied mainly in terms of lignin removal efficiency and molar mass distribution of dissolved lignin. The amount of lignin in pretreatment liquors increased along with an increase in the alkali charge of 0.8–4.4% and 0.6–3.4% of o.d. pine and birch wood, respectively. The most significant parameter affecting the molar mass of the dissolved lignin was shown to…
1995
About 340 g of a cycloaliphatic ionene (see formula given in the introduction) were fractionated by a continuous countercurrent extraction method (CPF). The efficiency of the separation was checked by viscometry and gel permeation chromatography (GPC). Ten different fractions with number average molecular masses between 16 000 and 29 000 D were obtained and their glass transition temperatures T g determined by differential scanning calorimetry (DSC) for their bromide and tetrafluoroborate salts. No molecular weight dependence of T g was found, in contrast to recently reported results with aliphatic ionenes, where - in case of the bromide - T g increases with rising molecular weight.
Detailed clinical, genetic and neuroimaging characterization of OFD VI syndrome.
2012
Oral-facial-digital syndrome type VI (OFD VI) is characterized by the association of malformations of the face, oral cavity and extremities, distinguished from the 12 other OFD syndromes by cerebellar and metacarpal abnormalities. Cerebellar malformations in OFD VI have been described as a molar tooth sign (MTS), thus, including OFD VI among the "Joubert syndrome related disorders" (JSRD). OFD VI diagnostic criteria have recently been suggested: MTS and one or more of the following: 1) tongue hamartoma(s) and/or additional frenula and/or upper lip notch; 2) mesoaxial polydactyly of hands or feet; 3) hypothalamic hamartoma. In order to further delineate this rare entity, we present the neuro…
The turnover of dental microwear texture: Testing the" last supper" effect in small mammals in a controlled feeding experiment
2020
Dental microwear texture (DMT) analysis is commonly applied for dietary reconstruction of vertebrates. The temporal scale on which dietarily informative microscopic wear forms on enamel surfaces is crucial to infer dietary flexibility and seasonality. Microwear is assumed to form shortly before the individual's death, reflecting information pertaining to the last meals consumed (“last supper” effect). In primate feeding experiments, microwear features formed within hours, suggesting rates of turnover within one to two weeks. As DMT formation experiments testing the persistence of microwear three-dimensionally (textures) are still lacking, we test how quickly DMTs form and pr…
Everything matters: Molar microwear texture in goats (Capra aegagrus hircus) fed diets of different abrasiveness
2020
There is an ongoing discourse about whether or not external abrasives influence the microscopic wear in herbivore teeth, including a statement that “dust does not matter”. We submitted the maxillary and mandibular second molar of 28 goats (Capra aegagrus hircus) to dental microwear texture analysis (DMTA). The study animals were divided into four groups, which received diets of increasing phytolith-based abrasiveness (L: lucerne based pellets, very low phytolith abrasion diet, acting as control; G: grass-based pellets, medium abrasive phytolith diet; GR: grass and rice husk pellets, high abrasion phytolith diet), or a diet with added external abrasives (GRS: the GR diet with add…
Peri-implant defect grafting with autogenous bone or bone graft material in immediate implant placement in molar extraction sites-1- to 3-year result…
2020
Objectives To evaluate the survival rate, the orobuccal bone resorption and stability of peri-implant hard and soft tissues following immediate implant placement of wide diameter implants in molar extraction sites and peri-implant defect grafting with autogenous bone (AB) or biphasic bone graft material (BBGM) with 1- to 3-year follow-up examinations. Material and methods Fifty wide diameter implants were placed in 50 patients immediately into molar extraction sockets by a flapless approach. Peri-implant defect augmentation was performed randomized with either AB or BBGM. Primary outcome variable was implant survival. Marginal bone level changes, orobuccal width of the alveolar crest, probi…
Periodontal health in shortened dental arches: A 10-year RCT
2020
Journal of prosthodontic research 64(4), 498-505 (2020). doi:10.1016/j.jpor.2020.01.005
Effect of Chlorhexidine on durability of two self-etch adhesive systems
2020
Background Despite of the rapid development in the field of dental adhesives, the issue of reduction in dentin bond durability has still not been resolved. The activity of dentinal endogenous enzymes such as MMPs is one of the most important causes of failure in resin composite restorations. The aim of this study was to investigate the influence of Chlorhexidine on micro-tensile bond strength of two types of commercially available self-etch adhesives. Material and Methods Twenty four sound and freshly extracted molars were selected. Four standardized flat mid-coronal dentinal disks were prepared from each tooth. The specimens were randomly assigned to 6 groups (n=16). Groups A(control group…