Correlated TKD/EDS - TEM - APT analysis on selected interfaces of CoSi2 thin films

Correlative analysis is a powerful way to relate crystallographic and chemical information to the properties of materials. In this work, a procedure is proposed to select and analyze interfaces of polycrystalline thin film materials through correlative transmission Kikuchi diffraction/energy dispersive X-ray spectroscopy (TKD/EDS), transmission electron microscopy (TEM) and atom probe tomography (APT). TKD provides information on the crystallographic orientation. The EDS analysis performed together with TKD in the scanning electron microscope (SEM) makes chemical information available allowing phases of similar crystal structure, but with a different composition to be distinguished. The information of TKD/EDS can be correlated to successive TEM and APT analysis on selected interfaces for structural and chemical analysis at the atomic scale. An interface of an epitaxial orientated grain of a polycrystalline CoSi₂ thin film on (111)Si is selected and analyzed. The selected interface has a twin character and shows facets of different orientation and area. Site-specific segregation of Ge to junctions of the facets is evidenced. The correlation between local strain from misfit (defects) at the interface and segregation is discussed.

Aqueous dispersions of organogel nanoparticles - potential systems for cosmetic and dermo-cosmetic applications

OBJECTIVE

The preparation and physicochemical characterization of organogel nanoparticles dispersed in water have been developed. These systems could be employed as nanocarrier for cosmetic applications or as hydrophobic reservoirs for drug delivery.

METHODS

Gelled particles of organic liquid and 12-hydroxystearic acid (organogelator) were obtained by hot emulsification (T>Tgel), with a surfactant (acetylated glycol stearate) and polymers (sodium hyaluronate and polyvinyl alcohol) as stabilizing agents, and cooling at room temperature (T<Tgel). An organic UVB sunscreen molecule, obtained by microwave activation, was used as a hydrophobic model molecule. The physicochemical properties of the starting organogel (gelation tests; rheological study) and the dispersed gelled particles (rheological study; particle mean size, size distribution, zeta-potential measurements; physical stability evaluation; UVB absorption and water resistance ability) were studied. The synthesis of sunscreen compound using microwave activation was also described.

RESULTS

According to the gelation test results, organogels were obtained with various organic liquids. Vaseline and almond oils were selected as organic medium for the gelled nanoparticle preparation. A preliminary formulation study was carried out in order to determine the optimal experimental conditions to obtain stable nanoparticle dispersions. Gelled nanoparticles contained the sunscreen model molecule, with mean size of 450 nm, polydispersity index of 0.18 and zeta-potential value above -30 mV, were obtained by ultrasound probe homogenization method. A comparative study of their dispersion ageing showed a greatly enhanced stability after gelation. According to the UVB absorption evaluation, gelled particles improved the photoprotective ability and the photostability of immobilized UVB blocker. They showed a high water resistance (~83%) even after 40 min of immersion.

CONCLUSION

The obtained results demonstrate the interest of these gelled nanoparticles and their aqueous dispersion for the preparation of new formulations for cosmetic and dermo-cosmetic applications.

Ex vivo absorption of promestriene from oil-in-water emulsion into infant foreskin

Hypospadias is a birth defect in which the urinary tract opening is not at the tip of the penis. Hypospadias surgery is frequently complicated by healing deficiencies. Topical treatments with oestrogens were reported to improve healing. In the present study, ex vivo percutaneous absorption of promestriene, a synthetic oestrogen resulting of the double esterification of estradiol was conducted as a pre-requisite for further clinical trial in infants. Penetration of promestriene into infant foreskin treated with commercial oil in water emulsion (10 μg mg(-1)) for 24 h was characterized showing controlled release properties enabling epidermal concentration more than six times higher than dermal concentration (4.13±2.46 mg g(-1) versus 0.62±0.84 mg g(-1), respectively). Furthermore, apparent promestriene fluxes into and through the skin (i.e., 1.5 μg cm(-2) h(-1) and<0.89 μg cm(-2) h(-1), respectively) were calculated from (i) drug amount retained into epidermis and dermis, or (ii) the limit of detection into the receptor fluid. In conclusion, less than 2% of initial dose were absorbed within 24h which compared well with others steroids applied topically in colloidal systems.

Impact of intravenous lipid emulsion infusion on the stratum corneum barrier function in patients receiving parenteral nutrition

The importance of the lipid matrix of stratum corneum (SC) in epidermal barrier function is well documented. Intravenous lipid emulsions (ILE) provide essential fatty acids (EFAs), main components of the SC lipid matrix. The objective of this study was to investigate the influence of ILE upon SC barrier function. The skin barrier was assessed by measuring transepidermal water loss (TEWL). Patients receiving lipid-containing parenteral nutrition (LCPN) were compared to patients receiving lipid-free PN (LFPN). In addition, a before/after LCPN introduction study was set up to limit the influence of inter-individual variability. Twenty-six patients receiving LCPN and seven patients receiving LFPN were included. Median age was not significantly different between the two groups. The TEWL of the LCPN group (9.05 g/m2/h) was significantly lower than the TEWL of the LFPN group (12.1 g/m2/h; Wilcoxon test: p = 0.016). The relative variation of TEWL before and after ILE treatment of 5 studied patients was 21.29 ± 10.28 %. ILE improve epidermal barrier function when compared to lipid-free parenteral treatments. Results of the before/after study confirm this conclusion and the usefulness of ILE intake for preventing excessive TEWL. SC barrier function improvement could be a choice criterion between the different ILE generations, in particular in burn patients and premature neonates.

Integrated polarization rotator made of periodic asymmetric buried Ta2O5 / silica sol-gel waveguides

A ridge waveguide technology exhibiting high polarization dependency is developed for new efficient multi-section passive polarization rotator applications. In the presented configuration, the calculated mode coupling between the waveguide sections is very efficient and allows a polarization rotation with a high extinction ratio at lambda=1,55 mum. Experimental results show efficient polarization rotation with low cross-talk levels (-16dB) and no significant excess losses between sections. However, the overall transmission efficiency is limited by propagation losses and coupling losses to standard optical fibers.

Kinetic and inhibition studies of cinnamoyl-CoA reductase 1 from Arabidopsis thaliana

Cinnamoyl coenzyme A reductase (CCR, EC 1.2.1.44), one of the key enzymes in the biosynthesis of lignin monomers, catalyzes the NADPH-dependent reduction of cinnamoyl-CoA esters to their corresponding cinnamaldehydes. AtCCR1, one of the two distinct isoforms isolated from Arabidopsis thaliana, was shown to be involved in lignin biosynthesis during development. Here, we report on the purification of the recombinant AtCCR1 protein expressed in Escherichia coli and the subsequent determination of its kinetic properties (K(m) and k(cat)/K(m) values) towards its main substrates i.e. feruloyl-CoA, sinapoyl-CoA, and p-coumaroyl-CoA esters. In addition, the potential inhibitory effect of five substrate-like analogs possessing an N-acetylcysteamine thioester group was tested on CCR activity using either feruloyl-CoA or sinapoyl-CoA as substrates. The K(i) values were in the range of 4.4-502 microM and the type of inhibition was found to be either uncompetitive or noncompetitive. Interestingly, for compounds 3 and 5, the type of inhibition was found to be different depending on the substrate used to monitor the enzyme activity. The best inhibitors were those possessing the feruloyl (compound 3) and sinapoyl (compound 5) aromatic moiety (4.1 and 7.1 microM) while the enzyme activity was monitored using the corresponding substrates.

[Potential pro-thrombotic effects of cyclooxygenase-2. inhibitors Two cases pf myocardial infarction]

Type 2 cyclo-oxygenase inhibitors are new anti-inflammatory drugs with better gastrointestinal tolerance than traditional non-steroidal anti-inflammatory drugs. They have no platelet anti-aggregant effects and there is still some discussion as to whether this new therapeutic class has any pro-thrombotic effects. The authors report two cases of myocardial infarction in patients considered to be at low risk treated by type 2 cyclo-oxygenase inhibitors.

The effect of hypertonic saline dextran solutions on hypoxic pulmonary vasoconstriction in anaesthetised piglets

Hypoxic pulmonary vasoconstriction (HPV) is a regulatory mechanism by which blood is diverted from poorly ventilated to better ventilated areas of the lung. The aim of the present study was to assess the extent to which hypertonic saline dextran and dextran solutions modify the magnitude of HPV during isovolumic haemodilution in intact acutely instrumented piglets. Eighteen large white piglets were anesthetised and assigned to two groups. Mean pulmonary arterial pressure (PAP) and cardiac output (Q), systemic arterial pressure and left arterial pressure (LAP) were measured. A decrease in Q was obtained by reducing venous return. This enabled measurement of transpulmonary pressures (mean PAP minus LAP) at four levels of Q in hyperoxia (inspiratory oxygen fraction (FiO2)=0.4) then in hypoxia (Fi,O2=0.1) in the two groups before blood soustraction (10 mL x kg(-1)) and after loading with sodium chloride (NaCl) 7.5% and dextran 6% or with dextran 6% alone. Dextran alone led to a decrease in mean PAP-LAP/Q values, and NaCl with dextran was associated with a significant shift of mean PAP-LAP/Q plots to higher pressures in hypoxia. Hypertonic saline dextran solution, as replacement fluid in isovolaemic haemodilution increased the magnitude of hypoxic pulmonary vasoconstriction, whereas dextran solution reduced it.

Effects of sevoflurane on hypoxic pulmonary vasoconstriction in anaesthetized piglets

In vitro, halogenated agents reduce the pulmonary vasoconstrictor response to alveolar hypoxia in isolated perfused lungs. However, studies in intact animals have been less convincing. The aim of the present study was to assess the effect of sevoflurane on hypoxic pulmonary vasoconstriction (HPV) in anaesthetized piglets using the pressure/cardiac index relationship (P/Q). Ten large white piglets were anaesthetized and mechanically ventilated, alternately in hyperoxia (FIO2 = 0.4) and hypoxia (FIO2 = 0.12). Multipoint plots of pulmonary arterial pressure (PAP) or differences between PAP and left atrial pressure (LAP) against Q were generated by gradual inflation of a balloon introduced into the inferior vena cava. P/Q relationships were established in hyperoxia and hypoxia at baseline, and then with sevoflurane. In hypoxia, pressure gradients (PAP-LAP) increased at every level of Q, thus demonstrating active pulmonary vasoconstriction. Sevoflurane at 1 MAC did not affect these P/Q relationships in hyperoxia or hypoxia as compared with baseline. Sevoflurane at a clinically relevant concentration (1 MAC) has no significant effect on HPV in anaesthetized piglets.

[Arterial hypertension due to compression of the renal artery, revealing ovarian cancer]

BACKGROUND

The etiologic work-up of hypertension with hyperaldosteronism and elevated serum renin includes search for renal artery stenosis. Intrinsic stenosis is a common finding, but hypertension secondary to extrinsic compression of the renal artery is exceptional.

CASE REPORT

A 48-year-old woman with an uneventful history was hospitalized for recent onset hypertension. Laboratory tests showed hypokaliemia, and elevated aldosterone and renin. Duplex Doppler exploration of the renal vessels evidenced extrinsic compression of the left renal artery by a tumoral mass found to be a nodal metastasis at surgery. Pathology reported cancer of the ovary. Blood pressure, and aldosterone and renin levels returned to normal after complete tumor resection. No antihypertensive treatment was required.

CONCLUSION

This is undoubtedly the first case of metastatic cancer of the ovary revealed by hypertension; it can be added to the list of 49 other published cases of extrinsic compression of the renal artery by various causes leading to hypertension. In most cases, surgical removal of the obstacle or nephrectomy provided cure of the hypertension.

[Acute obstructive renal failure and scrotal complete hernia of the bladder. Apropos of a case, review of the literature]

Massive herniation of the bladder into the scrotum is uncommon and can have a deleterious effect on the upper urinary tract. We report a case where complete scrotal hernia of the bladder lead to obstructive renal failure due to torsion of the trigone. Most simple bladder hernias can be explained by a prostate or uretral obstacle. The mechanism in our patient with no known prostate or uretral disease was the passage of the bladder via a defective inguinal canal caused by excessive obesity. This type of massive hernia has been reported in Sumo boxers. The effect on the upper urinary tract may be related to a fold in the terminal ureter or more exceptionally in the trigone. Immediate treatment requires urine drainage above the obstacle and intensive care. After stabilization, the anatomic position of the excluded bladder is re-established with reconstruction of the inguinal area, usually with a prosthesis. Any obstacle below the bladder must be removed.

Stent implantation in acute myocardial infarction

Among 138 patients treated with coronary angioplasty during acute myocardial infarction (AMI), 35 (25%) had stent implantation. Mean age was 56 years and 83% were men. Mean onset of chest pain was 6.0 +/- 5.3 hours, and previous thrombolytic therapy was given to 10 patients (29%). Infarct location was anterior in 19 (54%), inferior in 14 (40%), and lateral in 2 patients (6%). Thrombolysis in Myocardial Infarction trial flows 0,1, and 2 were seen in 24 (69%), 6 (17%), and 5 patients (14%), respectively. The culprit vessel was the left anterior descending artery in 18 (51%), right coronary artery in 14 (40%), left circumflex in 2 (6%), and left main coronary artery in 1 patient (3%). Mean vessel diameter was 3.3 +/- 0.3 mm. Indications were: primary in 5 (14%), suboptimal result in 8 (23%), nonocclusive dissection in 14 (40%), and occlusive dissection in 8 patients (23%). Angiographic thrombus after initial angioplasty was present in 12 patients (34%). A total of 46 stents were implanted; mean balloon diameter and pressure were 3.4 +/- 0.4 mm and 15.5 +/- 2.2 atm, respectively. Residual diameter stenosis was 4 +/- 7%. There were 2 deaths; sudden 1, and after elective coronary artery bypass grafting in the other; 2 patients (6%) had groin hematomas. Mean hospitalization was 9.9 +/- 5.0 days. Repeat angiography revealed no stent occlusion. With initial intravenous heparin for 3 to 7 days, all patients received aspirin and ticlopidine for 1 month. Thus, AMI is not a contraindication for stent implantation. The benefits of stenting are a high success rte, low residual diameter stenosis, and low incidence of in-hospital recurrent ischemia. Reduction in restenosis rate in this setting is likely but remains to be determined.

[Fatal poisoning caused by African viper's bite (Echis carinatus)]

The case is reported of a 44-year-old European who was bitten on the foot in Djibouti, probably by an African viper. Unusually, there wasn't any pain, nor any cardiovascular collapse nor any local swelling. An oedema of the lower limb started the day afterwards. Two days after the bite, the patient presented a generalized haemorrhagic syndrome, which led to his admission. There was a consumption of fibrinogen and prothrombin, without any decrease in the platelet count. Heparin was started (100 IU.kg-1.day-1), as well as fluid replacement (albumin, fresh frozen plasma, packed red cells). This allowed him to be transferred to France, where he arrived in anuria, with hyperpyrexia, and severe lower limb oedema and a haemorrhagic syndrome. There was a major extensive retroperitoneal haematoma spreading to the perineum. The four limbs were ischaemic. The patient's condition continued to worsen, developing hypoxic pulmonary oedema. He died on the seventh day after the bite, during a session of haemodialysis, from cardiovascular failure resistant to all the usual drugs. The principles of anti-venom therapy are recalled. Indeed, this should be started early enough and relies on large amounts of serum (greater than 50 ml).

Duplex sonographic findings in a popliteal vein aneurysm

We report on a new case of popliteal vein aneurysm, a rare anomaly almost always presented by pulmonary emboli. Usually the lesion is demonstrated on phlebography. However it is possible to establish the diagnosis with duplex sonography. A short review of the literature is included.

[Lumbar dracunculosis. Apropos of a case]

A young boy of 15 is examined because a swelling of the right lumbar fossa, of which etiology was not established. As a matter of fact, this swelling was the abscess wrapping up the anterior tip of a Medina filaria, which was rooted out by the patient himself in one step and without complication. Delay in diagnosis is explained by the lack of dracunculosis in the area, and by the migratory habits of this young patient who did consider his filariosis as a benign occurrence.

[Complications of measles in adult Africans. Apropos of 95 cases]

85 cases of measles with complications have been reported in Agades (Niger) from September 1983 to March 1985. The patients were all adults more than 15 years of age. Such complications are more frequent during winter season. The disease is superposable to the one observed in children: same course, same types of complications (superinfection, undernutrition, dehydration, broken compensation of a parasitosis, encephalitis). Mortality rate is next to the one observed in child (18.2%). Death occurs mainly in women (15 women/1 man). The more often fatal complications are: laryngitis, subcutaneous, emphysema, encephalitis, pernicious malaria, pregnancy complications. It appears highly desirable to extend to adults not yet diseased the immunisation campaign carried out for children.

[Scorpionism complicated by transient blindness. Apropos of a case]

A six years old child, string by a Leiurus quinquestriatus scorpion (Buthidae fam), got, 15 hours after having been string, consciousness disorders and convulsions within a feverish context. The general status recovered rapidly, but disorders of upper functions and a total blindness both occurred. The latter disappeared in few weeks time; central disorders improved progressively while a pyramidal syndrome appeared. No satisfactory explanation was given of such phenomena.