Search results for "Bone"

1979

The thermal degradation behavior of head-to-head (H-H) and head-to-tail (H-T) polystyrenes and poly(vinylcyclohexane)s has been investigated by direct pyrolysis in a mass spectrometer. Both H-H and H-T isomers show only small differences in their initial temperatures of decomposition but remarkably different degradation processes. Whereas H-T polystyrene decomposes in accordance with earlier investigations mainly by a radicalic depolymerization into the monomer and yields only a small amount of dimer and trimer, the H-H polystyrene shows no unzipping and only a statistic degradation into oligomeric styrenes. The formation of stilbene is a diagnostic reaction of H-H polystyrene. The pyrolysi…

Effective conjugation in conjugated polymers with strongly twisted backbones: A case study on fluorinated MEHPPV

2016

Conjugated polymers with strongly twisted backbones, such as MEHPPV with fluorinated vinylene units (F-MEHPPV), demand a redefinition of the all-important ‘effective conjugation length’ ECL, which we extract here by a facile graphical method. In MEHPPV (being essentially planar), the ECL coincides with the ‘maximum conducive chain length’ MCC and extends over about n ≈ 9 repetition units (RU). In F-MEHPPV, the MCC is similarly long with n ≈ 8, but the ECL localizes on just one RU. The strong twist in F-MEHPPV persists in the excited state, broadening the emission spectrum and quenching the fluorescence with reduced radiative and enhanced non-radiative rates.

Cathepsin L in Normal and Pathological Bone Remodeling

2011

Abstract Cathepsin L is a ubiquitous lysosomal cysteine endopeptidase that is mainly involved in the metabolic turnover of intracellular proteins. However, it is now well established that this enzyme may also be implicated in the regulation of other important biological processes includ- ing bone resorption. Therefore, altered expression levels of Cathepsin L may result in disturbances of bone homeo- stasis and, eventually, in the onset of pathological condi- tions associated with altered bone turnover. These observations support the concept that Cathepsin L may be regarded as an additional target for the development of novel therapeutic options for the treatment of patients with bone disea…

Corrigendum to “Effects of Oleuropein on tumor cell growth and bone remodeling: Potential clinical implications for the prevention and treatment of m…

2021

Oxygen isotope analysis of human bone phosphate evidences weaning age in archaeological populations

2015

Here we report bone phosphate oxygen (δ(18)Op) values from perinates/neonates and infants ( 50 years), have δ(18)Op values consistent with the consumption of local modern drinking water. The implications of this study for the reconstruction of weaning practices in archaeological populations are discussed, including variations observed with bone δ(15)Ncoll and δ(18)Op co-analysis and the influence of culturally-modified drinking water and seasonality. The use of this method to explore human mobility and palaeoclimatic conditions are also discussed with reference to the data presented.

Oxygen isotopes in mammal bone phosphate: A new tool for paleohydrological and paleoclimatological research?

1984

Abstract Oxygen isotope analyses of water in blood of humans and domestic pigs indicate that the oxygen isotope fractionation effects between ingested water and body water are the same in all specimens of the same species. The δ 18 O of body water has been shown to vary linearly with the mean δ 18 O of local meteoric water. This conclusion also holds for the bone phosphate. Thus, δ 18 O ( PO 3− 4 ) values of unaltered fossil bones from humans and domestic pigs can be used to reconstruct the δ 18 O values of local meteoric waters during the life-times of the mammals. Such data can be used for paleohydrological and paleoclimatological studies both on land and at sea.

Association between osteocalcin and cognitive performance in healthy older adults.

2016

INTRODUCTION: cognitive deterioration and reductions of bone health coincide with increasing age. We examine the relationship between bone composition and plasma markers of bone remodelling with measures of cognitive performance in healthy adults.METHODS: this cross-sectional study included 225 old (52% women, mean age: 74.4 ± 3.3 years) and 134 young (52% women, mean age: 23.4 ± 2.7 years) adult participants from the MyoAge project. Whole body bone mineral density was measured by dual-energy X-ray absorptiometry. Blood analyses included a panel of bone-related peptides (dickkopf-1, osteoprotegerin, osteocalcin (OC), osteopontin, sclerostin, parathyroid hormone and fibroblast growth factor …

Zebrafish Fins as a Model System for Skeletal Human Studies

2007

Recent studies on the morphogenesis of the fins ofDanio rerio(zebrafish) during development and regeneration suggest that a number of inductive signals involved in the process are similar to some of those that affect bone and cartilage differentiation in mammals and humans. Akimenko et al. (2002) has shown that bone morphogenetic protein-2b (BMP2b) is involved in the induction of dermal bone differentiation during fin regeneration. Many other groups have also shown that molecules from the transforming growth factor-beta superfamily (TGFβ), including BMP2, are effective in promoting chondrogenesis and osteogenesisin vivoin higher vertebrates, including humans. In the present study, we review…

Influence of Biologically Oriented Preparation Technique on Peri-Implant Tissues; Prospective Randomized Clinical Trial with Three-Year Follow-Up. Pa…

2019

Purpose: The objective of this prospective randomized clinical trial (RCT) was to analyze and compare the clinical behavior of three types of prosthesis supported by single implants in the posterior region after three years of functional loading. Materials and methods: Seventy-five implants were divided into three groups according to the type of prosthetic restoration: screw-retained crown (group GS); cemented crown without finishing line (biologically oriented preparation technique) (group GBOPT); and conventional cemented crown with finishing line (group GCC). After three years in function, clinical parameters (presence of keratinized mucosa, probing depths, bleeding on probing, and radio…

Evaluation of the primary stability in dental implants placed in low density bone with a new drilling technique, osseodensification: an in vitro study

2020

Background Primary stability is an important key determinant of implant osseointegration. We investigated approaches to improve primary implant stability using a new drilling technique termed osseodensification (OD), which was compared with the conventional under-drilling (UD) method utilized for low-density bones. Material and Methods We placed 55 conical internal connection implants in each group, in 30 low-density sections of pig tibia. The implants were placed using twist drill bits in both groups; groups Under Drilling (UD) and Osseodensification (OD) included bone sections subjected to conventional UD and OD drilling, respectively. Before placing the implants, we randomized the bone s…