Search results for "aggregate"

A new twist on sea silk : the peculiar protein ultrastructure of fan shell and pearl oyster byssus

2018

11 pages; International audience; Numerous mussel species produce byssal threads - tough proteinaceous fibers, which anchor mussels in aquatic habitats. Byssal threads from Mytilus species, which are comprised of modified collagen proteins - have become a veritable archetype for bio-inspired polymers due to their self-healing properties. However, threads from different species are comparatively much less understood. In particular, the byssus of Pinna nobilis comprises thousands of fine fibers utilized by humans for millennia to fashion lightweight golden fabrics known as sea silk. P. nobilis is very different from Mytilus from an ecological, morphological and evolutionary point of view and …

Metal Ions and Metal Complexes in Alzheimer's Disease.

2015

Background: Alzheimer’s disease (AD) is the most common form of dementia that seriously affects daily life. Even if AD pathogenesis is still subject of debate, it is generally accepted that cerebral cortex plaques formed by aggregated amyloid-β (Aβ) peptides can be considered a characteristic pathological hallmark. It is well known that metal ions play an important role in the aggregation process of Aβ. Methods: This review focuses on the anti-Aβ aggregation activity of chelating ligands as well as on the use of metal complexes as diagnostic probes and as potential drugs. Conclusion: While chelating agents, such as curcumin or flavonoid derivatives, are currently used to capture metal ions …

Detecting Protein Aggregation on Cells Surface: Concanavalin A Oligomers Formation

2009

A number of neurodegenerative diseases involve protein aggregation and amyloid formation. Recently evidence has emerged indicating small-transient prefibrillar oligomers as the primary pathogenic agents. Noteworthy, strict analogies exist between the behaviour of cells in culture treated with misfolded non-pathogenic proteins and in pathologic conditions, this instance together with the observation that the oligomers and fibrils are characterised by common structural features suggest that common mechanisms for cytotoxicity could exists and have to be perused in common interactions involved in aggregation.We here report an experimental study on ConcanavalinA (ConA) aggregation and its effect…

A Note on Laws of Motion for Aggregate Distributions

2020

I derive the law of motion for the aggregate distribution directly from the laws of motion for the individuals’ states. By relying on concepts from measure theory, the derivation is concise and intuitive. I address random shocks both at the micro level and at the macro level. Micro-level shocks completely cancel at the aggregate level provided that a law of large numbers applies. Therefore, the law of motion for the aggregate distribution is a deterministic process in the absence of macro-level uncertainty. If there are macro-level risks, the law of motion for the aggregate distribution exhibits a stochastic component additionally. I illustrate the formalism in a model of wealth accumulatio…

SURFACTANT SELF-ASSEMBLING IN THE GAS PHASE: AOT METAL ION NEGATIVE CHARGED AGGREGATES

2008

Investigation of molecular dimers by ensemble and single molecule spectroscopy

2002

International audience; We have investigated molecular dimers with different electronic coupling strengths by bulk and single molecule spectroscopy. In one of the dimers the two monomers (perylene-monoimide) are directly connected via a single bond while in the other one they are separated by the benzil motif. The close proximity of the monomers in the first case gives rise to excitonic band splitting which is clearly observable in the bulk absorption spectra. For the benzil structure the electronic interactions are governed by Förster-type energy hopping between the monomers. Fluorescence intensity trajectories at the single molecule level show one-step and two-step bleaching behaviour whi…

Influence of social factors on avoidable mortality: a hospital-based case-control study.

2005

Objective. The effect of socioeconomic factors on avoidable mortality at an individual level is not well known, since most studies showing this association are based on aggregate data. The purpose of this study was to determine socioeconomic differences between those patients who die of avoidable causes and those who do not die. Methods. A matched case-control study was carried out regarding in-hospital avoidable mortality (Holland's medical care indicators) that occurred in a university hospital serving a Spanish-Mediterranean population during a 30-month period. Results. We studied 82 cases of death from avoidable causes and 300 controls matched on medical care indicators and age. The var…

The prognostic value of sentinel lymph node micrometastases in patients with invasive breast carcinoma

2016

The prognostic value of sentinel lymph node micrometastases in invasive breast cancer patients is still widely debated. Even if, in the absence of unequivocal guidelines, the axillary lynphadenectomy is not still performed in the routine clinical care of these patients.We have retrospectively analyzed 746 patients with operable invasive breast cancer and clinically negative axillary lymph nodes. These patients underwent conservative surgery or total mastectomy with sentinel lymph node biopsy. Patients with micrometastases in the sentinel lymph node treated with axillary dissection has been checked and the involvement of the remaining lymph nodes analyzed. Patients with micrometastases in th…

The accuracy of sentinel lymph node biopsy in the treatment of multicentric invasive breast cancer using a subareolar injection of tracer.

2008

BACKGROUND: The aim of this study was to evaluate the feasibility and the accuracy of sentinel lymph node biopsy in multicentric breast cancer (MBC) performed by means of a subareolar (SA) injection of both 99Tc-labeled human albumin colloid and lymphazurin. METHODS: Between January 2002 and October 2007, 34 patients with MBC with clinically negative axilla underwent sentinel lymph node biopsy (SLNB) followed by total axillary node dissection (AD). Overall successful identification rate of SLN was 100%; there were no false negatives and overall accuracy rate was 100%. RESULTS: The mean number of sentinel lymph nodes (SLNs) identified was 1.8 +/- 0.88 (range = 1-4); the mean number of axilla…

Lymphoscintigraphy with peritumoral injection versus lymphoscintigraphy with subdermal periareolar injection of technetium-labeled human albumin to i…

2014

Background Preoperative lymphoscintigraphy is without doubt a valid method for the detection of the sentinel lymph node (SLN). There has been considerable debate regarding the optimal site for the introduction of the tracer; various sites include peritumoral (PT), periareolar (PA), subdermal, and intradermal injection. Purpose To evaluate retrospectively the lymphoscintigraphic identification rate of peritumoral (PT) injection versus subdermal periareolar (PA) injection in the detection of SLNs in breast cancer. Material and Methods Between October 2002 and December 2011, a cohort of 906 consecutive patients with biopsy proven breast cancer underwent 914 SLN biopsy procedures. A total of 33…