Late Outcomes of Carotid Artery Stenting for Radiation Therapy-Induced Carotid Stenosis

PURPOSE

Carotid artery stenting (CAS) appears as a promising alternative treatment to carotid endarterectomy for radiation therapy (RT)-induced carotid stenosis. However, this is based on a poor level of evidence studies (small sample size, primarily single institution reports, few long-term data). The purpose of this study was to report the long-term outcomes of a multicentric series of CAS for RT-induced stenosis.

METHODS

All CAS for RT-induced stenosis performed in 11 French academic institutions from 2005 to 2017 were collected in this retrospective study. Patient demographics, clinical risk factors, elapsed time from RT, clinical presentation and imaging parameters of carotid stenosis were preoperatively gathered. Long-term outcomes were determined by clinical follow-up and duplex ultrasound. The primary endpoint was the occurrence of cerebrovascular events during follow-up. Secondary endpoints included perioperative morbidity and mortality rate, long-term mortality rate, primary patency, and target lesion revascularization.

RESULTS

One hundred and twenty-one CAS procedures were performed in 112 patients. The mean interval between irradiation and CAS was 15 ± 12 years. In 31.4% of cases, the lesion was symptomatic. Mean follow-up was 42.5 ± 32.6 months (range 1-141 months). The mortality rate at 5 years was 23%. The neurologic event-free survival and the in-stent restenosis rates at 5 years were 87.8% and 38.9%, respectively. Diabetes mellitus (p=0.02) and single postoperative antiplatelet therapy (p=0.001) were found to be significant predictors of in-stent restenosis. Freedom from target lesion revascularization was 91.9% at 5 years.

CONCLUSION

This study showed that CAS is an effective option for RT-induced stenosis in patients not favorable to carotid endarterectomy. The CAS was associated with a low rate of neurological events and reinterventions at long-term follow-up.

Calcium phosphate precipitation in experimental gaps between fluoride-containing fast-setting calcium silicate cement and dentin

A novel fast-setting calcium silicate cement containing fluoride (novel-CSC) has been developed for applications in tooth crowns. The aim of this study was to assess the ability of the novel-CSC to close the experimental gaps at the dentin-cement interface. The novel-CSC was tested against Vitrebond and GC Fuji II LC. Experimental gaps of 50 or 300 μm width were created between the materials and dentin. Specimens with the 300-μm-wide gap were immersed in phosphate-buffered saline and the closed gap area was measured during 96 h. All specimens with 50 or 300 μm gap width were analyzed by scanning electron microscopy equipped with energy dispersive X-ray spectroscopy (SEM/EDX) to assess the morphology and chemical composition of the precipitates after 96 h immersion in phosphate-buffered saline. High-resolution micro-computed tomography (μCT) was used to evaluate the integrity and continuity of the precipitiates after 96 h and 180 d. In all novel-CSC samples, precipitates closed the gap area completely after 96 h. The SEM/EDX revealed that the globular precipitates closing the gap area were mainly composed of calcium and phosphorus. After 180 d, μCT indicated thicker precipitates compared with initial precipitates only in the novel-CSC group, whereas no precipitates were observed in resin-modified glass ionomers. Novel-CSC promoted continuous precipitation of calcium phosphate, including apatite, and closed the experimental gaps.

Deactivation behavior of an iron-molybdate catalyst during selective oxidation of methanol to formaldehyde

Molybdenum loss, phase transformations and catalytic performance of an iron molybdate catalyst.

Mucosal melanoma: clinical, histological and c-kit gene mutational profile of 86 French cases

BACKGROUND

Mucosal melanomas are rare and highly aggressive tumours. Few studies evaluated mucosal melanomas of locations other than the head and neck region, and other than those of the Asian population.

OBJECTIVES

The objective of this study was to analyse the clinical and histological features, as well as the mutational status of c-kit and b-raf gene of mucosal melanoma in any localization in a French series.

METHODS

We investigated clinical (sex, age, performance status, survival, treatment of the patients and lack of pigmentation of the tumours) and histopathological features (ulceration, Breslow's index, mitotic rate), as well as the mutational status of c-kit and b-raf of 86 mucosal melanomas diagnosed in 15 years in four French University Hospitals.

RESULTS

Most melanomas affected women (72%) and the genital region (46.5%). A fifth of melanomas were amelanotic. 81% of melanomas had a Breslow's index ≥1, whereas all glans melanomas, and most vulvar melanomas had a Breslow index ≤1 mm. Overall survival was 54% at 3 years; 11.6% of the 43 tested mucosal melanomas were c-kit-mutated while the 15 tested genital melanomas were not. The c-kit gene mutation did not influence the overall survival. Age ≥ 50, amelanotic type and performance status ≥1 were not poor prognostic factors in our series.

CONCLUSION

This study confirmed that mucosal melanomas are rare and could be difficult to diagnose being often amelanotic and in hidden sites. Most melanomas were thick at the diagnosis, but glans and vulvar melanomas were thinner probably because of their greater visibility. The frequency of the c-kit mutation varied depending on the initial tumour site. In our series, the prognosis was poor, independently from c-kit mutations and the patient's general health and age. The presence of metastasis at diagnosis was associated with a worse prognosis indicating the importance of an early diagnosis.

Combining light-harvesting with detachability in high-efficiency thin-film silicon solar cells

Efforts to realize thin-film solar cells on unconventional substrates face several obstacles in achieving good energy-conversion efficiency and integrating light-management into the solar cell design. In this report a technique to circumvent these obstacles is presented: transferability and an efficient light-harvesting scheme are combined for thin-film silicon solar cells by the incorporation of a NaCl layer. Amorphous silicon solar cells in p-i-n configuration are fabricated on reusable glass substrates coated with an interlayer of NaCl. Subsequently, the solar cells are detached from the substrate by dissolution of the sacrificial NaCl layer in water and then transferred onto a plastic sheet, with a resultant post-transfer efficiency of 9%. The light-trapping effect of the surface nanotextures originating from the NaCl layer on the overlying solar cell is studied theoretically and experimentally. The enhanced light absorption in the solar cells on NaCl-coated substrates leads to significant improvement in the photocurrent and energy-conversion efficiency in solar cells with both 350 and 100 nm thick absorber layers, compared to flat-substrate solar cells. Efficient transferable thin-film solar cells hold a vast potential for widespread deployment of off-grid photovoltaics and cost reduction.

Historical Hallmarks of Anticoagulation and Antiplatelet Agents

Thrombosis is a well known phenomenon among physicians since antiquity. A variety of peculiar agents, such as leeches and bark, were used to prevent it. Hirudin was used during the 19th century. The next eon, heparin, strepokinase, urokinase, TPA, dicumarol, warfarin, aspirin, ticlopidine, Clopidogrel, SSHA and SP54 provoked huge advances in anticoagulation. During 21st century with the use of fondaparinux, dabigatran, rivaroxaban and Ticagrelor antithrombotic prevention and therapeutic interaction entered an era of medical challenges. Although the risk after a thrombotic episode is now highly reduced, blood clots still present damaging or even lethal consequences in human organisms and further research is strongly recommended.

[Léopold Chauveau (1870-1940), a doctor, writer, painter and sculptor]

Léopold Chauveau born in Lyon was a renowned writer during the years 1920-1930, then nearly forgotten. He was the son of Augustin Chauveau (1827-1917) the famous veterinary who had a leading role in the scientific life in the 19th century. Léopold Chauveau was particulary appreciated for his tales for kids. Some of his compilations were illustrated by his friend the painter Pierre Bonnard. His novels were published by the NRF so he was very closed to Gide, to Martin du Gard, to Eugene Dabit partners of this publishing house. At the first he was a medecine doctor, house doctor in Paris hospitals, ORL-surgeon, surgeon "beyond the fight" on the battle front during the WWI. But at that time greatly moved by the slaughter he had seen and by the deaths of his nearest and dearest : his wife and two of his four sons, he completely renounced his medical practice. He actually became writer, talented illustrator, monsters sculptor... He died exhausted during the debacle in 1940. His tales for children are a talk to little Renaud (his dead son) beyond the hereafter, they are an outled for one'sorrow. All these texts are now studied by specialists, republished, discovered by the Japanese. All his books and novels are very sensitive,full of a philo- sophic spirit and a delicious imagination. His pictures are outstanding.

Apatite precipitation on a novel fast-setting calcium silicate cement containing fluoride

Aim: Calcium silicate cements are widely used in endodontics. Novel fast-setting calcium silicate cement with fluoride (Protooth) has been developed for potential applications in teeth crowns including cavity lining and cementation.

Objective: To evaluate the surface apatite-forming ability of Protooth compositions as a function of fluoride content and immersion time in phosphate-buffered saline (PBS).

Material and methods: Three cement compositions were tested: Protooth (3.5% fluoride and 10% radiocontrast), ultrafast Protooth (3.5% fluoride and 20% radiocontrast), and high fluoride Protooth (15% fluoride and 25% radiocontrast). Powders were cap-mixed with liquid, filled to the molds and immersed in PBS. Scanning electron microscopy, energy dispersive X-ray analysis, and Raman spectroscopy were used to characterize the precipitations morphology and composition after 1, 7, 28, and 56 days. Apatite/belite Raman peak height indicated the apatite thickness.

Results: Spherical calcium phosphate precipitations with acicular crystallites were formed after 1-day immersion in PBS and Raman spectra disclosed the phosphate band at 965 cm⁻¹, supporting the apatite formation over Protooth compositions. The apatite deposition continued and more voluminous precipitations were observed after 56 days over the surface of all cements. Raman bands suggested the formation of β-type carbonated apatite over Protooth compositions. High fluoride Protooth showed the most compact deposition with significantly higher apatite/belite ratio compared to Protooth and ultrafast Protooth after 28 and 56 days.

Conclusions: Calcium phosphate precipitations (apatite) were formed over Protooth compositions after immersion in PBS with increasing apatite formation as a function of time. High fluoride Protooth exhibited thicker apatite deposition.

[A quarantine of plague at the lazaret of Frioul in 1901]

In September 1901, a cruise for work and pleasure is organized in Mediterranean including VIP all firstclass (politicals, scientists, clergymen...) These were 174 passengers on the ship Senegal. After a departure from Marseille, the ship must quickly turn and go back on account of a sailor in the crew might be sicked with plague. A quarantine was organised in the lazaret of Frioul's island. This man died but an another actually ill will be cured. All the conference participents landed in the Frioul lazaret stayed only seven days on place and remained uninjured. This misadventure will be studied by scientific people and given to authorities. So, Pr Jules Buckoy' communication to the french Academy of medicine. Adrien Proust gave a report. In this doctoral thesis in 1902 Joseph Pellissier reported all the cases of plague cured in the Frioul lazaret. The physician Charles Leroux made an epidemiologic study about effects and troubles with plague serums. A lot of orig- inal and beautiful photographs, notably those by the famous passenger, Léon Gaumont, are joined in our presentation.

[The fate of the wood of the Fabrica of 1543]

Destiny of the wood blocks which have been used for engraving of illustrations of 1543 edition of the Fabrica is really outstanding. Several times lost and found again, they were transported over Europe in a surprising conservation state, for more than four centuries. Made by the famous Venitian wood-cutters, the blocks cross the Alps to join up Basel in Switzerland and Joannes Oporinus, the printer. Felix Platter uses 48 Vesalian wood-blocks for his own treaty in 1583. These blocks reappear in Augsburg in 1706, at the printer Andreas Maschenbauer's; they are found again by Von Wollter from Ingolstadt: they are used to illustrate Leveling's anatomy book in 1781 and 1783. Ingolstadt university and the blocks will be transferred to Landshut because of Napoleon's war, then to Munich in 1826. But in 1892 147 blocks are found again in the library; and are forgotten again. Forty years after, 230 blocks are discovered again! Icones anatomicae represent the last and fabulous edition made in 1934. The Second World War closes this epic with the library fire on July 13th 1944: none of these precious blocks remains today.

Hydrated human corneal stroma revealed by quantitative dynamic atomic force microscopy at nanoscale

The structures and mechanical properties of human tissues are significantly influenced by water. The functionality of the human cornea can be linked to the hydrated collagen fibers. By applying quantitative dynamic atomic force microscopy to investigate morphological and mechanical property variations of corneal stroma under different hydration levels, we found that the collagen fibers in the stromal tissue show the specific periodicities and the stiffness of giga-Pa magnitude at 40% humidity. However, under increasing hydration, the collagen fibers clearly show nanoparticle structures along the fibers with the stiffness in mega-Pa magnitude. By increasing the hydration time, the stroma regains the fiber structure but with larger diameter. The age-dependency in stiffness was further investigated. The interplay of structures and nanomechanical mapping may be applied for the future diagnosis and assessment or even pathologic analysis.

[Clinical study of a cohort of 94 children with influenza A(H1N1) on the Réunion Island]

We conducted a monocentric retrospective study at the Félix-Guyon Regional Hospital, Saint-Denis, Réunion Island, from August 1, 2009 to September 30, 2009. We included 94 children with nasal and/or throat swabs tested positive for influenza A(H1N1)v during the study period. We describe the clinical, biological, and radiological presentations, the hospitalization rate, and the antiviral and antibiotic therapies. Children between six months and two years were the ones most at risk of severe forms and the first risk factor was asthma. Children with risk factors were at risk of severe forms except immune suppressed children. 7% of our cohort had only digestive signs. Recommendations for antiviral treatment were followed in 75% of the treated children. Risk factors and clinical signs, not age, guided physicians in the initiation of treatment.

Interactions Between Hydrogen and Silicon Acceptors in p-Type GaAs:Si

We show that silicon acceptors can be neutralized in p-type GaAs: Si. SIMS analysis shows that the deuterium concentration closely follows the net acceptor concentration. Infrared absorption spectroscopy reveals lines at 2094.7cm-1 and 1514.5cm-1 in hydrogenated and deuterated samples respectively. The ratio r of the two frequencies is 1.383 indicating that the lines are related to hydrogen isotopes. The reduction of the intensity of the local vibrational mode (LVM) of SiAs after neutralization is consistent with the formation of SiAs-H bonds. From SIMS data, it is concluded that most of the hydrogen present in the passivated material is complexed with silicon. A microscopic model of the Si-H complex is proposed.

Carrier Removal in n+ GaAs:Si by Proton Implantation. a Spectroscopic Study

Protons and deuterons have been implanted in n+ GaAs:Si epilayers. Localized vibrational modes (LVM's) associated to H- and D-related defects are observed in the as-implanted samples and they account presumably for the carrier removal in the compensated region, but a small concentration of Si-H passivating centers is already present. LVM spectroscopy shows that after a 200° C annealing, passivation predominates over compensation while a 400° C annealing extends partial passivation throughout the layer.

Hydrogen Diffusion in Boron Doped Diamond: Evidence of Hydrogen-Boron Interactions

Deuterium diffusion has been investigated in boron doped diamond as a function of the diffusion temperature and the boron concentration. The results show that, up to 480°C, hydrogen diffusion is limited by the boron concentration with a diffusion activation energy of 0.35 eV for [B] = 5×1019 cm−3. This first experimental evidence of deuterium-boron interactions in diamond is interpreted as the result of hydrogen ionization and diffusion of fairly mobile protons which form pairs with negatively charged boron acceptors

Interface Stress and an Apparent Negative Poisson's Ratio in Ag/Ni Multilayers

By use of dc-magnetron sputtering, (111) textured Ag/Ni multilayered thin films were deposited with nominal bilayer repeat lengths ranging from 2 nm to 250 nm. Bulk and interface stresses were obtained from X-ray diffraction and measurements of substrate curvatures. Both in-plane and out-of-plane expansions were observed in the Ni layers, and a compressive interface stress of −2.24±0.21 J/m2 was found. This is in agreement with a previously published result of the interface stress in Ag/Ni thin films which had, as opposed to the present multilayers, a high level of total stress.

Fibronectin adsorption, cell adhesion, and proliferation on nanostructured tantalum surfaces

The interaction between dental pulp derived mesenchymal stem cells (DP-MSCs) and three different tantalum nanotopographies with and without a fibronectin coating is examined: sputter-coated tantalum surfaces with low surface roughness <0.2 nm, hut-nanostructured surfaces with a height of 2.9 +/- 0.6 nm and a width of 35 +/- 8 nm, and dome structures with a height of 13 +/- 2 nm and a width of 52 +/- 14 nm. Using ellipsometry, the adsorption and the availability of fibronectin cell-binding domains on the tantalum surfaces were examined, as well as cellular attachment, proliferation, and vinculin focal adhesion spot assembly on the respective surfaces. The results showed the highest fibronectin mass uptake on the hut structures, with a slightly higher availability of cell-binding domains and the most pronounced formation of vinculin focal adhesion spots as compared to the other surfaces. The proliferation of DP-MSCs was found to be significantly higher on dome and hut surfaces coated with fibronectin compared to the uncoated flat tantalum surfaces. Consequently, the results presented in this study indicate that fibronectin-coated nanotopographies with a vertical dimension of less than 5 nm influence cell adhesion. This rather interesting behavior is argued to originate from the more available fibronectin cell-binding domains observed on the hut structures.

[Joseph Rollet & the shadow of Ricord]

There are three distinguished names in French venereology during the first half of XIXth century: Ricord, Bassereau and Rollet. Ricord is above all a colourful practitioner of fashionable circles and he takes care of a lot of VIP: political people, actors, writers ... With his influence he takes strong opinions but in fact he has only linked gonorrhoea with veneral ulcers. Joseph Rollet head surgeon in the Antiquaille hospital of Lyon, continuing the studies of Bassereau, proves many basic points about venereal diseases often opposed to the theories of Ricord. So theses two scientists too discret or provincial will remain in the shadow of Ricord.

Spatial and temporal changes in the morphology of preosteoblastic cells seeded on microstructured tantalum surfaces

It has been widely reported that surface morphology on the micrometer scale affects cell function as well as cell shape. In this study, we have systematically compared the influence of 13 topographically micropatterned tantalum surfaces on the temporal development of morphology, including spreading, and length of preosteoblastic cells (MC3T3-E1). Cells were examined after 0.5, 1, 4, and 24 h on different Ta microstructures with vertical dimensions (heights) of 0.25 and 1.6 mum. Cell morphologies depended upon the underlying surface topography, and the length and spreading of cells varied as a function of time with regard to the two-dimensional pattern and vertical dimension of the structure. Microstructures of parallel grooves/ridges caused elongated cell growth after 1 and 4 h in comparison to a flat, nonstructured, reference surface. For microstructures consisting of pillars, cell spreading was found to depend on the distance between the pillars with one specific pillar structure exhibiting a decreased spreading combined with a radical change in morphology of the cells. Interestingly, this morphology on the particular pillar structure was associated with a markedly different distribution of the actin cytoskeleton. Our results provide a basis for further work toward topographical guiding of cell function.

The influence of glancing angle deposited nano-rough platinum surfaces on the adsorption of fibrinogen and the proliferation of primary human fibroblasts

We have used the glancing angle deposition (GLAD) method as a simple and fast method to generate nano-rough surfaces for protein adsorption experiments and cell assays. The surface roughness and the detailed geometrical surface morphology of the thin films were characterized by atomic force microscopy (AFM) and scanning electron microscopy (SEM). As the GLAD deposition angle approaches grazing incidence, sharp and whisker-like columnar protrusions are formed. Smaller and less sharp surface features appear for the thin films synthesized at higher deposition angles. By changing the GLAD deposition angle together with the total amount of mass deposited per area on the respective surfaces, the size of the surface features can be varied on the nanoscale. Using the GLAD topographies as model surfaces, we have investigated the influence of the nano-roughness on fibrinogen adsorption and on the proliferation of primary human fibroblasts. It is found that fibrinogen, an important blood protein, preferentially adheres on the whisker-like nano-rough substrates in comparison to a flat surface. Furthermore, the proliferation of the human fibroblasts is significantly reduced on the nano-rough substrates. These results demonstrate that the GLAD technique can be used to fabricate nano-rough surface morphologies that significantly influence both protein and cellular adhesion to surfaces and are therefore well suited for biological assays.

Enhanced surface activation of fibronectin upon adsorption on hydroxyapatite

In this study the adsorption characteristics and the structure of fibronectin adsorped on hydroxyapatite (Ha) and a reference gold substrate (Au) is examined by quartz crystal microbalance with dissipation (QCM-D) and atomic force microscopy (AFM) at the following concentrations: 20 microg/mL, 30 microg/mL, 40 microg/mL, 100 microg/mL, 200 microg/mL, and 500 microg/mL. The conformational changes of the fibronectin molecules upon surface binding were examined as well with monoclonal antibody directed against the cell binding-domain (CB domain) of fibronectin. The QCM-D and AFM results show that the fibronectin uptake is larger on Au as compared with Ha regardless of the protein bulk concentration used in the experiment, suggesting that the individual fibronectin molecules in general attach to the surfaces in a more unfolded configuration on Ha. Moreover the dissipation values obtained with QCM-D indicate that the individual fibronectin molecules bind in a more compact and rigid configuration on Au compared to the Ha surface. In particular the monoclonal antibody data show that the CB domain on fibronectin is more available on Ha, where such cell-recognizing abilities are more pronounced at low fibronectin surface coverage. The results demonstrate that the detailed molecular structure of fibronectin and its functional activity depend significantly on both the underlying surface chemistry as well as the fibronectin surface coverage.

Fibronectin adsorption on tantalum: the influence of nanoroughness

The complex mechanisms of protein adsorption at the solid-liquid interface is of great importance in many research areas, including protein purification, biocompatibility of medical implants, biosensing, and biofouling. The protein adsorption process depends crucially on both the nanoscale chemistry and topography of the interface. Here, we investigate the adsorption of the cell-binding protein fibronectin on flat and nanometer scale rough tantalum oxide surfaces using ellipsometry and quartz crystal microbalance with dissipation (QCM-D). On the flat tantalum oxide surfaces, the interfacial protein spreading causes an increase in the rigidity and a decrease in the thickness of the adsorbed fibronectin layer with decreasing bulk protein concentration. For the tantalum oxide surfaces with well-controlled, stochastic nanometer scale roughness, similar concentration effects are observed for the rigidity of the fibronectin layer and saturated fibronectin uptake. However, we find that the nanorough tantalum oxide surfaces promote additional protein conformational changes, an effect especially apparent from the QCM-D signals, interpreted as an additional stiffening of the formed fibronectin layers.

Bovine serum albumin adsorption on nano-rough platinum surfaces studied by QCM-D

The adsorption of bovine serum albumin (BSA) on platinum surfaces with a root-mean-square roughness ranging from 1.49nm to 4.62nm was investigated using quartz crystal microbalance with dissipation (QCM-D). Two different BSA concentrations, 50microg/ml and 1mg/ml, were used, and the adsorption studies were complemented by monitoring the antibody interaction with the adsorbed BSA layer. The adsorption process was significantly influenced by the surface nano-roughness, and it was observed that the surface mass density of the adsorbed BSA layer is enhanced in a non-trivial way with the surface roughness. From a close examination of the energy dissipation vs. frequency shift plot obtained by the QCM-D technique, it was additionally observed that the BSA adsorption on the roughest surface is subject to several distinct adsorption phases revealing the presence of structural changes facilitated by the nano-rough surface morphology during the adsorption process. These changes were in particular noticeable for the adsorption at the low (50microg/ml) BSA concentration. The results confirm that the nano-rough surface morphology has a significant influence on both the BSA mass uptake and the functionality of the resulting protein layer.

Critical size of crystalline ZrO(2) nanoparticles synthesized in near- and supercritical water and supercritical isopropyl alcohol

Nanocrystalline ZrO(2) samples with narrow size distributions and mean particle sizes below 10 nm have been synthesized in a continuous flow reactor in near and supercritical water as well as supercritical isopropyl alcohol using a wide range of temperatures, pressures, concentrations and precursors. The samples were comprehensively characterized by powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), and small-angle X-ray scattering (SAXS), and the influence of the synthesis parameters on the particle size, particle size distribution, shape, aggregation and crystallinity was studied. On the basis of the choice of synthesis parameters either monoclinic or tetragonal zirconia phases can be obtained. The results suggest a critical particle size of 5-6 nm for nanocrystalline monoclinic ZrO(2) under the present conditions, which is smaller than estimates reported in the literature. Thus, very small monoclinic ZrO(2) particles can be obtained using a continuous flow reactor. This is an important result with respect to improvement of the catalytic properties of nanocrystalline ZrO(2).

[The arrival of the "grand pox" at the hôtel-Dieu de Lyon]

Founded in 542, the Hospital hôtel-Dieu in Lyons is considered as the oldest French Hospital. At the beginning it was a place to receive and assist the poor and pilgrims and in the middle of the XVth century it received infectious patients during some epidemic periods. As King Charles VIII came back from Naples his troops suffering from syphilis arrived in Lyons in October 1495 and were treated in the Hospital hôtel-Dieu so that it became the first French Hospital to treat syphilitic patients. On the 7th of July 1496, a request of the "Consulat" gave the first information mentioned about syphilitic soldiers in Lyons and the well-known French physician Symphorien Champier was the first to publish about syphilis. For three centuries the Hospital hôtel-Dieu tried to move away syphilitic patients and it succeeded in 1802 as the Hospital L'Antiquaille was built.

Crystal blocking measurements of the time delay of fission induced by 32S, 48Ti, and 58Ni bombardment of W

The time delay in fission induced by bombardment of W with 180 MeV 32S, 240-255 MeV 48Ti, and 315-375 MeV 58Ni has been measured by observation of crystal blocking. There is a clear narrowing and a small increase in the minimum yield of the angular dips for fission compared with scaled dips for elastically scattered ions. This is interpreted as a fission delay of about 2 as, only weakly dependent on energy and atomic number. The delay is longer by 1 to 2 orders of magnitude than obtained from standard interpretations of measurements of prescission neutrons and giant-dipole-resonance gamma rays and from calculations of the nuclear dynamics in heavy-ion reactions.

Nanostructure of the neurocentral growth plate: Insight from scanning small angle X-ray scattering, atomic force microscopy and scanning electron microscopy

In this study, the experimental techniques scanning electron microscopy (SEM) including energy-dispersive X-ray analysis, atomic force microscopy (AFM) and scanning small angle X-ray scattering (SAXS) have been exploited to characterize the organization of large molecules and nanocrystallites in and around the neurocentral growth plate (NGP) of a pig vertebrae L4. The techniques offer unique complementary information on the nano- to micrometer length scale and provide new insight in the changes in the matrix structure during endochondral bone formation. AFM and SEM imaging of the NGP reveal a fibrous network likely to consist of collagen type II and proteoglycans. High-resolution AFM imaging shows that the fibers have a diameter of approximately 100 nm and periodic features along the fibers with a periodicity of 50-70 nm. This is consistent with the SAXS analysis that yields a cross-sectional diameter of the fibers in the range of 90 to 112 nm and a predominant orientation in the longitudinal direction of the NGP. Furthermore, we find inhomogeneities around 7 nm in the NGP by SAXS analysis. Moving towards the bone in the direction perpendicular to the growth plate, a systematic change in apparent thickness is observed, while the large-scale structural features remain constant. In the region of bone, the apparent thickness equals the mean mineral thickness and increases from 2 nm to approximately 3.5 nm as a function distance from the NGP. The mineral particles are organized as plates in a rather compact network structure. We have demonstrated that SEM, AFM and SAXS are valuable tools for the investigation of the organization of large molecules and nanocrystallites in the NGP and adjacent trabecular bone. Our findings will be an important basis for future work into identifying the defects on nanometer length scale responsible for idiopathic scoliosis and other growth-plate-related diseases.

Rare earth ions and Ge nanocrystals in SiO(2)

Experimental studies of Ge nanocrystals embedded in SiO(2) films doped with Er and Yb deposited by rf-magnetron sputtering are presented. Although inter-band photoluminescence (PL) from the Ge nanocrystals is not observed, it is nevertheless found that the presence of Ge nanocrystals is crucial for obtaining light emission from Er(3+) and Yb(3+). For both kinds of rare earth ions, the intensity of the related PL line has a maximum after heat treatment at 800 °C, and the PL excitation spectra for the two cases are very similar. This suggests that the presence and the structure of the nanocrystals are important for the efficiency of PL from Er(3+) and Yb(3+). Experiments performed with multilayer structures of Ge nanocrystals and SiO(2) show that the optically active rare earth ions are located in the SiO(2) layers, and not inside the Ge nanocrystals. The mechanism of energy transfer from Ge nanocrystals to the rare earth ions is found to be non-optical.

QCM-D studies of attachment and differential spreading of pre-osteoblastic cells on Ta and Cr surfaces

The quartz crystal microbalance with dissipation (QCM-D) technique was employed to characterize initial cell adhesion in terms of attachment and spreading of pre-osteoblastic MC3T3-E1 cells on Ta and Cr surfaces. Evaluation of initial cell adhesion established a correlation between input cell number and the shifts in frequency (f) and dissipation (D). The f-shift was found to be much larger in serum-free medium as compared to a medium including serum; hence, initial cell adhesion was subsequently evaluated in serum-free medium. During the first hour of adhesion, we found a positive correlation between the QCM-D f-shift and the average area of the spread cells, as measured by cryo-scanning electron microscopy (cryo-SEM). Finally, the QCM-D technique was used to study cell adhesion on different metal oxide surfaces. Initial cell adhesion on Ta was found to induce a larger f-shift as compared to Cr, indicating larger spreading of cells on Ta. Cryo-SEM data confirmed that spreading of cells on Cr was on average only two-thirds the spreading on Ta. Our results demonstrate that the QCM-D technique is a versatile technique to quickly distinguish initial cell-surface interactions on different biomaterials.

Cell volume increase in murine MC3T3-E1 pre-osteoblasts attaching onto biocompatible tantalum observed by magnetic AC mode atomic force microscopy

Magnetic AC mode (MACmode) atomic force microscopy (AFM) was used to study murine (mouse) MC3T3-E1 preosteoblastic cells attached to biocompatible tantalum substrates. Cell volumes of attached cells derived from AFM images were compared to volumes of detached cells in suspension measured by the Coulter sizing technique. An increase of approximately 50% in cell volume was observed when the cells attached to planar tantalum substrates and developed a flattened structure including lamellipodia. We address thoroughly the issues general to the AFM determination of absolute cell volumes, and compare our magnetic AC mode AFM measurements to hitherto reported cell volume determinations by contact mode AFM.

Adsorption of fibrinogen on tantalum oxide, titanium oxide and gold studied by the QCM-D technique

The adsorption of human fibrinogen on tantalum oxide, titanium oxide and gold surfaces has been studied by quartz crystal microbalance with dissipation (QCM-D) at 37 degrees C. Two different protein concentrations have been used, one close to physiological concentration (1 mg/ml) and one significantly lower (0.033 mg/ml). To further characterize the adsorbed fibrinogen layer, the subsequent binding of both polyclonal and monoclonal antibodies of fibrinogen is studied. We found that the viscoelastic properties of the fibrinogen layer depends strongly on the initial protein concentration. The trend is generally seen for all three surfaces. The fibrinogen layer on gold and tantalum oxide is found to have the same viscoelastic properties, which are different from those found for the fibrinogen layer adsorbed on titanium oxide. The dependency of the surface chemistry on the viscoelastic properties of the fibrinogen layer is observed directly for the 0.033 mg/ml solution, and indirectly through the antibody response for the 1 mg/ml solution. From this we conclude that the orientation and/or denaturation of fibrinogen on a surface depends on the surface chemistry and the protein concentration in the solution, and that the binding of antibodies is a useful way to detect this difference.

Shallow donors with high n-type electrical conductivity in homoepitaxial deuterated boron-doped diamond layers

Diamond is a unique semiconductor for the fabrication of electronic and opto-electronic devices because of its exceptional physical and chemical properties. However, a serious obstacle to the realization of diamond-based devices is the lack of n-type diamond with satisfactory electrical properties. Here we show that high-conductivity n-type diamond can be achieved by deuteration of particularly selected homo-epitaxially grown (100) boron-doped diamond layers. Deuterium diffusion through the entire boron-doped layer leads to the passivation of the boron acceptors and to the conversion from highly p-type to n-type conductivity due to the formation of shallow donors with ionization energy of 0.23 eV. Electrical conductivities as high as 2omega(-1) x cm(-1) with electron mobilities of the order of a few hundred cm2 x V(-1) x s(-1) are measured at 300 K for samples with electron concentrations of several 10(16) x cm(-3). The formation and break-up of deuterium-related complexes, due to some excess deuterium in the deuterated layer, seem to be responsible for the reversible p- to n-type conversion. To the best of our knowledge, this is the first time such an effect has been observed in an elemental semiconductor.