Nanocrystalline Hydroxyapatite-Bisphosphonate Composites

The direct synthesis of hydroxyapatite─1,8-octan-bisphosphonic acid (HAp─BISPH) nanocrystals has been carried out in presence of increasing amounts of BISPH in solution, by hydrothermal method at 120 °C for 15 h. XRD, IR, NMR-MAS (31P, 1H and 13C), TEM, AFM, TGA and chemical analysis were used to characterize the structure, morphology and composition of the products. X-ray powder diffraction patterns show that the incorporation of bisphosphonate moieties induces a significant loss of the material crystallin-ity and a clear decrease of the crystallite size. TEM and AFM images show that the precipitated apatite particles prepared in the presence of this bisphosphonic acid are nanosized. The IR and NMR-MAS 1H spectroscopy show that the BISPH can replace the OH− groups of the apatitic structure. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3519

Analysis of the resistance to crack propagation in SENT test specimens printed in ABS using parallel or crossed filaments between layers

Additive manufacturing techniques continue to develop and cover all industrial fields. However, the performances of aspect and mechanical behavior of the parts obtained by this process remain to be mastered and are still the subject of current research works. Among these performances, the one corresponding to the resistance to the propagation of cracks. In order to improve this very interesting property in various industrial fields, it is desirable to master the understanding of crack propagation in this type of structure obtained by 3D printing. The objective of this paper is to analyze and understand the effect of the adopted raster angle on the crack propagation in SENT specimens obtained by FDM in ABS (Acrylonitrile-Butadiene-Styrene). Two approaches were developed: one is experimental to determine the critical stress intensity factor KIC and the other is numerical to predict the possible paths of crack propagation

Sarcoidosis with heart involvement: a rare association of terrible prognosis, a report of two cases

Sarcoidosis is a multisystemic disorder of unknown etiology which is characterized by the formation of non-caseating granulomas in involved tissues. Cardiac involvement is one of the least common manifestations and it can occur at any point of time during the course of sarcoidosis. Here we present the case of 2 patients with known sarcoidosis who develop cardiac abnormalities in the absence of known primary cardiac cause. In our report, we would like to draw attention to the importance of considering heart involvement in any case with systemic sarcoidosis especially in young age

Topological descriptors for 3D surface analysis

We investigate topological descriptors for 3D surface analysis, i.e. the classification of surfaces according to their geometric fine structure. On a dataset of high-resolution 3D surface reconstructions we compute persistence diagrams for a 2D cubical filtration. In the next step we investigate different topological descriptors and measure their ability to discriminate structurally different 3D surface patches. We evaluate their sensitivity to different parameters and compare the performance of the resulting topological descriptors to alternative (non-topological) descriptors. We present a comprehensive evaluation that shows that topological descriptors are (i) robust, (ii) yield state-of-the-art performance for the task of 3D surface analysis and (iii) improve classification performance when combined with non-topological descriptors.Comment: 12 pages, 3 figures, CTIC 201

Page number not for citation purposes 1 Des Furoncles résistants aux antibiotiques: penser à la myiase !!

Les myiases sont des infections parasitaires par des larves de mouches. La localisation cutanée doit être évoquée de retour d'un pays tropical devant une évolution inhabituelle de lésions cutanées. Nous rapportons une observation d'un militaire tunisien, ayant séjourné en République Démocratique du Congo. Il était atteint de myiase cutanée simulatrice d'une furonculose résistante aux antibiotiques. L'intérêt de cette observation est de souligner l'importance d'évoquer la myiase dont le traitement est simple et rapide chez un patient de retour de zone d'endémie.Key words: Furoncles, myiase, mouche

Poussée de maladie de Kaposi et élévation du CA 19-9: Penser à la tuberculose!

La maladie de Kaposi (MK) est une entité pathologique qui peut survenir chez les patients VIH positifs et dans le cadre d'une immunodépression, d'origine tuberculeuse très rarement. On décrit le cas d'une MK chez un patient VIH négatif au décours d'une tuberculose. Nous rapportons le cas d'un patient âgé de 81 ans, VIH négatif, ayant présenté deux nodules angiomateux de l'avant bras gauche dont la biopsie cutanée était en faveur d'une MK. L'évolution était marquée 2 mois plus tard, par  l'apparition de placards angiomateux extensifs des deux membres supérieurs et d'adénopathies cervicales jugulo-carotidiennes bilatérales. La biopsie ganglionnaire était en faveur d'une  tuberculose ganglionnaire. Par ailleurs, il avait un taux sérique élevé des CA 19-9. La régression de l'étendue des lésions au niveau des membres  supérieurs et la  normalisation du taux sérique des CA 19-9 ont été obtenues sous traitement anti-tuberculeux. Chez les patients atteints d'une MK avec une élévation des CA 19-9, il faut penser à la tuberculose

Coexistence of pyoderma gangrenosum and sweet’s syndrome in a patient with ulcerative colitis

Pyoderma gangrenosum (PG) and Sweet's Syndrome (SS) are inflammatory skin diseases caused by the accumulation of neutrophils in the skin and, rarely, in internal organs. These neutrophilic dermatosis (NDs) are distinguished by the existence of forms of transition or overlap. They are frequently associated to systemic diseases especially hematologic and gastrointestinal ones. We report a case of a patient with ulcerative colitis (UC) who successively developed two types of NDs: PG then SS. A 66 years old patient with a history of UC consulted in July 2012 for an erythematous swelling of the back of the right hand treated with antibiotics without improvement. At that time, bacteriological samples were negative. In October 2012, he was hospitalized for polyarthralgia and impaired general condition. In physical examination, he had vesiculobullous plaque of 10 cm long of the right hand and wrist, infiltrated erythematous plaque on the right leg and another topped with a large pustule at the left ankle. Skin biopsy showed at the back of the right hand an aspect of PG and at the infiltrated plaques of the ankle an aspect of SS. Prednisone was started with improvement of the skin lesions and a recovery condition. The combination of PG and SS has already been described in cases of hematologic malignancy and rarely in UC. There is also the notion of passage from a neutrophilic dermatosis to another. Indeed, a typical lesion initially of SS can evolve to a future PG. This case demonstrates that neutrophilic dermatoses form a continous spectrum of entities that may occur in UC

Artificially decreasing cortical tension generates aneuploidy in mouse oocytes

Human and mouse oocytes’ developmental potential can be predicted by their mechanical properties. Their development into blastocysts requires a specific stiffness window. In this study, we combine live-cell and computational imaging, laser ablation, and biophysical measurements to investigate how deregulation of cortex tension in the oocyte contributes to early developmental failure. We focus on extra-soft cells, the most common defect in a natural population. Using two independent tools to artificially decrease cortical tension, we show that chromosome alignment is impaired in extra-soft mouse oocytes, despite normal spindle morphogenesis and dynamics, inducing aneuploidy. The main cause is a cytoplasmic increase in myosin-II activity that could sterically hinder chromosome capture. We describe here an original mode of generation of aneuploidies that could be very common in oocytes and could contribute to the high aneuploidy rate observed during female meiosis, a leading cause of infertility and congenital disorders

Significantly less wear of UHMWPE rubbing against pyrocarbon than against CoCr

\ua9 2024 The AuthorsThe history of joint replacement can be framed as a battle to reduce wear. Pyrocarbon has been shown to be a low wear material, but can low wear against an ultra high molecular weight polyethylene (UHMWPE) counterface be achieved? To investigate this research question, a 50-station, clinically validated wear screening machine was used. Half the stations tested UHMWPE pins against pyrocarbon discs, and half the stations tested UHMWPE pins against cobalt chromium (CoCr) discs. The test rig ran at 1Hz, the nominal contact stress was 2.07 MPa, and testing ran to 5 million cycles. A biomimetic lubricant was used, it was replaced every 500,000 cycles. At the end of testing, the UHMWPE pins rubbing against pyrocarbon discs had a statistically significant reduced wear, compared with the UHMWPE pins rubbing against CoCr discs (p ≤ 0.01). Analysis of the discs at the end of testing showed greater adherence of phospholipids on the pyrocarbon discs than the CoCr discs. In turn, it was also seen that far less UHMWPE was attached to the pyrocarbon discs than to the CoCr discs. Based on this evidence, it is suggested that pyrocarbon surfaces are associated with reduced adhesive wear of UHMWPE compared with CoCr surfaces. In addition, at the end of testing, the CoCr discs were found to be significantly rougher than the pyrocarbon discs. Therefore, pyrocarbon maintained a smoother surface than CoCr, likely meaning that abrasive wear of UHMWPE was reduced compared with CoCr

Impact of hyperhomocysteinemia on histo-morphometry and histochemistry of pancreas in sand rat, Psammomys obesus

Introduction. The sand rat, Psammomys obesus, a diurnal rodent, which lives in the south-east of the Algerian Sahara, is an excellent animal model for the study of diabetes, atherosclerosis, and metabolic syndrome. Hyperhomocysteinemia (Hhcy), defined by high plasma homocysteine level, is associated with many diseases affecting various organs (heart, blood vessels, liver…). Objectives. The objective of this study was to determine the effect of Hhcy on the sand rats pancreas. Material and methods. The rats were divided into two groups: a control group received its natural diet with halophile plant of the Chenopodiacae family (Suaedamollis), and an experimental group received the same diet associated with an intraperitoneal administration of methionine (150 mg/kg body weight/day) during 6 months. Histological and histochemical analysis of Psammomys pancreas were realized and completed by a morphometric study. Results. The methionine excess led to a hyperhomocysteinemia in Psammomys obesus. Several alterations were observed in pancreas extracellular matrix of hyperhomocysteinemic rats, marked by an accumulation of fibrillar collagens, and glycoproteins leading to a fibrosis. This accumulation was observed in the Langerhans islets, and in the exocrine pancreas (interstitial tissue, around blood vessels, and excretory channels). A disorganization of the vascular wall, and a micro- and macrovesicular steatosis were also observed in the pancreas of hyperhomocysteinemic rats. Conclusion. The hyperhomocysteinemia, generated by the methionine excess, leads to a pancreatic extracellular matrix remodeling in Psammomys obesus