Search results for "polymer"
showing 10 items of 10504 documents
Abnormalities in alpha-dystroglycan expression in MDC1C and LGMD2I muscular dystrophies
2004
We recently identified mutations in the fukutin related protein (FKRP) gene in patients with congenital muscular dystrophy type 1C (MDC1C) and limb girdle muscular dystrophy type 2I (LGMD2I). The sarcolemma of these patients typically displays an immunocytochemical reduction of alpha-dystroglycan. In this report we extend these observations and report a clear correlation between the residual expression of alpha-dystroglycan and the phenotype. Three broad categories were identified. Patients at the severe end of the clinical spectrum (MDC1C) were compound heterozygote between a null allele and a missense mutation or carried two missense mutations and displayed a profound depletion of alpha-d…
Osteogenic differentiation of periodontal fibroblasts is dependent on the strength of mechanical strain
2012
Abstract Objective During orthodontic therapy the correct strength of mechanical strain plays a key role for bone remodelling during tooth movement. Aim of this study was to investigate the osteogenic differentiation of human periodontal ligament fibroblasts (HPdLF) depending on the applied strength of mechanical strain compared to osteoblasts (HOB). Design HPdLF and HOB were loaded with different strengths (1%, 5% and 10%) of static mechanical strain (SMS) for 12 h in vitro. Viability was verified by MTT and apoptosis by TUNEL assay. Gene expression of cyclin D1, collagen type-1 (COL-I), alkaline phosphatase (ALP), osteocalcin, osteoprotegerin (OPG) and receptor activator of the NF-κB liga…
Comparisons of processing and strength properties of two adhesive systems for composite joints
2007
Abstract In the present study rheological, static and impact tests are carried out on two adhesive resins usually employed in marine applications; then single lap joint tests are conducted on composites joints evidencing the effect of the curing time of both resins on the mechanical properties of the joint. The applicability and workability conditions of the adhesive resins are determined evaluating the curing evolution by a preliminary rheological analysis; then the relation of curing properties with the mechanical performances of the resins themselves and with ones of the composite joints is estimated. Static flexural and Izod impact tests are performed on the resins at increasing time af…
Arthralgia as an early extraintestinal symptom of Whipple's disease. Report of five cases.
1997
Five patients with Whipple's disease all suffered from arthralgia for a long time (15 years in one case) before developing gastrointestinal or other symptoms. In all patients, arthralgia was seronegative, and there was no evidence of joint destruction. Arthralgias were symmetric and migrating. Whipple's disease is part of the differential diagnosis of enteropathic arthralgia. Thereby, the polymerase chain reaction can be a helpful tool to prove Whipple's disease in difficult differential diagnosis.
Numerical experimental analysis of hybrid double lap aluminum-CFRP joints
2015
Abstract Due to their reliability and ease of assembly, both the adhesively bonded and the mechanical joints are commonly used in different fields of modern industrial design and manufacturing, to joint composite materials or composites with metals. As it is well known, adhesively bonded joints are characterized by high stiffness and good fatigue life, although delamination phenomena localized near the free edges may limit their use, especially for applications where corrosive environments and/or moisture can lead to premature failure of the bonding. In these cases, a possible alternative is given by the well-known mechanical joints. On the contrary, these last joints (bolted, riveted) requ…
Sequence analysis of the DRB1 promoter reveals limited polymorphism with no influence on gene expression.
2001
HLA-class II promoters contain a set of conserved regulatory regions necessary for constitutive and induced gene expression. For the HLA-DQB as well as for the DRB1 promoter sequence, polymorphisms with influence on gene expression have been reported. In contrast to these data we could show that there is very limited allele-specific polymorphism among the HLA-DRB1 promoter alleles. In a long range PCR we amplified a DNA sequence containing the promoter and the second exon of the DRB1 gene in one fragment. Nested PCR products of this PCR fragment for the promoter and for the second exon were analysed by DNA sequencing to allow the linkage of a promoter to its DR allele. Most investigated DRB…
Parathyroid hormone-related peptide and 8701-BC breast cancer cell growth and invasion in vitro: evidence for growth-inhibiting and invasion-promotin…
1995
It has been previously reported that 8701-BC cells, derived from a primary carcinoma of the breast, constitutively express parathyroid hormone-related peptide (PTHrP) gene and that N-terminal PTHrP immunoreactivity can be found in cell medium. Here we have firstly measured immunoreactive PTHrP in 8701-BC cell medium using antibodies raised against midregion and C-terminal fragments, and also demonstrated the expression of PTH/PTHrP receptor by 8701-BC cells. Secondly, we have examined the role, if any, elicited by diverse PTHrP domains on 8701-BC cell proliferation, and invasive behaviour in vitro related to production of extracellular proteolytic enzymes. Our data show that PTHrP [1-34], a…
Extracellular matrix regulation of PTHrP and PTH/PTHrP receptor in a human breast cancer cell line
1999
AbstractIt was previously reported that 8701-BC breast cancer cells express the gene for parathyroid hormone-related peptide (PTHrP) and its cognate receptor (PTHrP-R), and release immunoreactive PTHrP in the extracellular medium; it was also found that PTHrP, in turn, exerts a role on the proliferative and invasive behavior in vitro of the same cell line. On the other hand, evidence has been produced that adhesion of 8701-BC cells onto different collagen substrates influences in various ways a number of phenotypic expressions, such as cell growth, motility, invasion of reconstituted basement membrane and production of lytic enzymes of the extracellular matrix (ECM). In light of these previ…
STABILITY AND ORGANOCATALYTIC EFFICIENCY OF N-HETEROCYCLIC CARBENES ELECTROGENERATED IN ORGANIC SOLVENTS FROM IMIDAZOLIUM IONIC LIQUIDS
2015
The kinetic of degradation of 1-butyl-3-methylimidazole-2-ylidene (selected as model N-heterocyclic carbene - NHC), generated in organic solvents by cathodic reduction of the parent 1-butyl-3- methylimidazolium salts BMIm-X, was studied by a simple voltammetric analysis. The effect of NHC degradation rate on the efficiency of an organocatalyzed reaction (the synthesis of g-butyrolactone from cinnamaldehyde and trifluoromethylacetophenone) was investigated. The nature of the solvent and of the anion X have a remarkable effect on the stability of the NHC, the bis(trifluoromethylsulfonyl) imide anion being the best for a long lasting carbene (while acetonitrile seems to be the worst solvent). …
Hyaluronan‐coated poly(propylene imine) dendrimers as biomimetic nanocarriers of doxorubicin
2022
A coating technology based on low molecular weight hyaluronic acid (HA) and ferulic acid (FA) was applied to the coating of low generation poly(propylene imine) dendrimers through a biocompatible hexa(ethylene glycol) spacer. The ensuing HA-FA-HEG-PPID dendrimeric materials showed interesting loading capability (between 7.65% and 9.08%) regarding anticancer agent doxorubicin, and their interactions with the drug appeared to hamper the drug release in the physiological environment. Thus, the stable nanostructured loaded delivery systems were able to internalize into cells expressing the HA receptor CD44 and to demonstrate high cytotoxicity comparable to that shown by equivalent amounts of fr…