Hierarchical TiO2 photoanode for dye-sensitized solar cells.

Hierarchical or one-dimensional architectures are among the most exciting developments in material science these recent years. We present a nanostructured TiO(2) assembly combining these two concepts and resembling a forest composed of individual, high aspect-ratio, treelike nanostructures. We propose to use these structures for the photoanode in dye-sensitized solar cells, and we achieved 4.9% conversion efficiency in combination with C101 dye. We demonstrate this morphology beneficial to hamper the electron recombination and also mass transport control in the mesopores when solvent-free ionic liquid electrolyte is used.

[Relevance of a driving simulator in the assessment of handicapped individuals]. / Intérêt du simulateur de conduite pour la reprise de la conduite automobile en situation de handicap.

AIMS: To evaluate the value of our driving simulator in deciding whether or not to allow patients with physical and/or cognitive deficits to resuming driving and to analyze whether or not the medical expert's final decision is based more on the results of the driving simulator than those of the neuropsychological examination. METHODS: One hundred and twenty-three patients were evaluated with the driving simulator. Thirty-five of those with cognitive deficits also underwent a neuropsychological examination prior to the medical expert's decision on driving aptitude. In cases of uncertainty or disagreement, a driving assessment in real conditions was performed by a driving instructor. RESULTS: In cases of physical handicap, the medical expert's decision concurred with that of the occupational therapist. For brain-injured patients, there was a significant correlation between the neuropsychologist's opinion and that of the occupational therapist (kappa=0.33; P=0.01). However, the sensibility and specificity were only 55 and 80%, respectively. The correlation between an occupational therapy decision based on the driving simulator and that of the medical expert was very significant (kappa=0.81; P<0.0001) and the sensibility and specificity were 84 and 100%, respectively. In contrast, these values were lower (63 and 71%, respectively) for the correlation between the neuropsychologist's opinion and that of the medical expert. CONCLUSION: Our driving simulator enables the danger-free evaluation of driving aptitude. The results mirror an in situ assessment and are more sensitive than neuropsychological examination. In fact, the neuropsychologist's opinion often is more negative or uncertain with respect to the patient's real driving aptitude. When taking a decision on a patient's driving aptitude, the medical expert is more inclined to trust the results of the driving simulator.

Clinical implementation of a Monte Carlo based treatment plan QA platform for validation of Cyberknife and Tomotherapy treatments.

PURPOSE: The main focus of the current paper is the clinical implementation of a Monte Carlo based platform for treatment plan validation for Tomotherapy and Cyberknife, without adding additional tasks to the dosimetry department. METHODS: The Monte Carlo platform consists of C++ classes for the actual functionality and a web based GUI that allows accessing the system using a web browser. Calculations are based on BEAMnrc/DOSXYZnrc and/or GATE and are performed automatically after exporting the dicom data from the treatment planning system. For Cyberknife treatments of moving targets, the log files saved during the treatment (position of robot, internal fiducials and external markers) can be used in combination with the 4D planning CT to reconstruct the actually delivered dose. The Monte Carlo platform is also used for calculation on MRI images, using pseudo-CT conversion. RESULTS: For Tomotherapy treatments we obtain an excellent agreement (within 2%) for almost all cases. However, we have been able to detect a problem regarding the CT Hounsfield units definition of the Toshiba Large Bore CT when using a large reconstruction diameter. For Cyberknife treatments we obtain an excellent agreement with the Monte Carlo algorithm of the treatment planning system. For some extreme cases, when treating small lung lesions in low density lung tissue, small differences are obtained due to the different cut-off energy of the secondary electrons. CONCLUSIONS: A Monte Carlo based treatment plan validation tool has successfully been implemented in clinical routine and is used to systematically validate all Cyberknife and Tomotherapy plans.

Efficient Lateral Electron Transport inside a Monolayer of Aromatic Amines Anchored on Nanocrystalline Metal Oxide Films.

A monolayer of a phosphonated triarylamine adsorbed on nanocrystalline TiO2, ZrO2, or Al2O3 film deposited on conducting glass displays reversible electrochemical and electrochromic behavior although the redox potential of the electroactive molecules (0.80 V vs NHE) lies in the forbidden band of the semiconducting or insulating oxides. The mechanism of charge transport was found to involve hole injection from the conducting support followed by lateral electron hopping within the monolayer. The apparent diffusion coefficient ranged from 2.8 × 10(-12) m(2) s(-1) in the neat 1-ethyl-2-methylimidazolium bis(trifluoromethylsulfonyl)imide (EtMeIm(+)Tf2N(-)) to 1.1 × 10(-11) m(2) s(-1) in acetonitrile + 2 M EtMeIm(+)Tf2N(-). A percolation threshold for electronic conductivity was found at a surface coverage corresponding to 50% of a full monolayer.

A swift dye uptake procedure for dye sensitized solar cells.

Solar cells based on swift self-assembled sensitizer bis(tetrabutylammonium)-cis-di(thiocyanato)-N,N'-bis(4-carboxylato-4'-carboxylic acid-2,2'-bipyridine)ruthenium(II) (N719) on double layers of 12 + 4 microm thick nanocrystalline TiO2 films exhibit the incident monochromatic photon-to-current conversion efficiency (IPCE) 90% and show a short circuit current density of 17 mA cm(-2), 750 mV open circuit potential and 0.72 fill factor yielding power conversion efficiencies over 9.18% under AM 1.5 sun. For the first time highest power conversion efficiencies are obtained for dye sensitized solar cells using a swift self-assembled procedure.

A fibrin sealant for perforated and preperforated corneal ulcers.

Fibrin sealant is used to close perforated or preperforated corneal ulcers. In addition to the usual advantages of cyanoacrylates it is degraded physiologically and provides a good support for corneal healing. Corneal grafting can be avoided when contraindicated or postponed when conditions allow. This technique has been successful in nine eyes of eight patients.

Intracerebral electrode implantation system. Technical note.

A new technique for deep-brain electrode implantation is described. A very flexible nontraumatic electrode guided by a central stylet and a new electrode head-fixation screw are the two unique features of this system. Electrodes can be guided precisely and their watertight fixation to the bone by means of the special screw is reliable and totally reversible. The system has been designed to fit most of the stereotaxic frames currently in use.

[Proposed treatment of the Urrets-Zavalia syndrome. A propos of one reversible case]. / Proposition de traitement du syndrome d'Urrets-Zavalia. A propos d'un cas réversible.

Regression of Urrets-Zavalia's syndrome was obtained in one case after treatment administered according to a strict sequence following keratoplasty for keratoconus: sympatholytic drops (guanethidine 5%-Ismelin) every 4 hours for 24 hours, followed the next day, when mydriasis had been slightly reduced, by parasympathomimetic drops (pilocarpine 2%). Marked myosis was observed and treatment discontinued. This resulted in recurrence of the mydriasis, but this was successfully treated by repeating therapy. Pilocarpine drops were progressively diminished, followed by a slow reduction of guanethidine drops over 8 weeks, resulting in only slight residual anisocoria. This treatment is based on the physiopathological concept of sympathetic spasm with parasympathetic inhibition, and it is suggested that reduction of spasm should be obtained before administration of therapy to stimulate the sphincter. Pharmacological data on the compounds employed are discussed.

[Fungal mycotic aneurysms and multiple cerebral abscesses caused by Scedosporium apiospermum. Apropos of a case with review of the literature]. / Anévrysmes mycotiques et abcès cérébraux multiples à Scedosporium apiospermum. A propos d'une observation avec revue de la littérature.

The authors report a case of intracranial fungal aneurysm and brain abscesses. The compromised host was a young drowned woman. Scedosporium Apiospermum was isolated in fungal culture from abscess. Radiological and clinical pictures are typical of the hyphal form.

Synthesis, characterization, and DFT-TDDFT computational study of a ruthenium complex containing a functionalized tetradentate ligand.

A ruthenium complex trans-[Ru(L)(NCS)2], L = 4,4' ''-di-tert-butyl-4',4' '-bis(carboxylic acid)-2,2':6',2' ':6' ',2' ''-quaterpyridine (N886), was synthesized and characterized by spectroscopic and electrochemical methods. The absorption spectrum of the N886 complex shows metal-to-ligand charge-transfer transitions in the entire visible region and quasi-reversible oxidation and reduction potentials at E(1/2) = +0.38 and -1.92 V vs ferrocene, respectively. The electronic spectra of the N886 complex were calculated by density functional theory (DFT)-time-dependent DFT, which qualitatively reproduces the experimental absorption spectra for both the protonated and deprotonated species. From the analysis of the computed optical transitions of N886, we assign its absorption bands as mixed Ru/SCN-to-quaterpyridine charge-transfer transitions, which extend from the near-IR to the UV regions. The panchromatic response of the N886 complex renders it as a suitable sensitizer for solar energy conversion applications based on titanium dioxide mesoporous electrodes. The preliminary results using the N886 complex as a sensitizer in a dye-sensitized solar cell, with an electrolyte containing 0.60 M butylmethylimidazolium iodide, 0.03 M I2, and 0.50 M tert-butylpyridine in a mixture of acetonitrile and valeronitrile (volume ratio 1:1), show 40% incident photon-to-current efficiencies, yielding under standard AM 1.5 sunlight a short-circuit photocurrent density of 11.8 +/- 0.2 mA/cm(2), an open-circuit voltage of 680 +/- 30 mV, and a fill factor of 0.73 +/- 0.03, corresponding to an overall conversion efficiency of 5.85%.

[Functional assessment of the hand in neurologic rehabilitation]. / Evaluation fonctionnelle de la main en réadaptation neurologique.

Functional evaluation of hand is essential in neurorehabilitation because it provides crucial information about capacities/incapacities of patients during their daily activities. Then therapists can plan realistic aims. This evaluation is usually devoted to occupational therapists, who have different tests and scales to measure the functions of hand. The movements and gestures of hands are so various and complex that no test is better than another. Here we select a few specific tests to evaluate hand functions and we present their advantages and interest in neurorehabilitation.

[Assessment of car driving skills in brain injured individuals]. / Evaluation des aptitudes à la conduite automobile chez le cérébrolésé.

Independent driving is considered as very important for a full independence and social integration of disabled people. In these patient with disabilities or handicaps, the driving skills must be carefully assessed, especially in presence of a moderate dysexecutive syndrome. A precise neurological and neuropsychological examination is usually necessary to evaluate aptitudes for driving. Standard neuropsychological tests are often limited to value the brain injury patients. At the moment, assessment on driving simulators really improves the opinion of medical experts, as they give qualitative and quantitative data on reproducible conditions. In fact, in more than 80% of cases, the tests on driving simulators allow to determine if the patient is able to drive or no, with or without a specially adapted vehicle. However, in a small percentage of cases, the evaluation of open-road driving by a driving instructor is necessary, proving that driving simulators will never take over from reality.

Multipolar hollow-core electrode for brain recordings.

A multicontact macroelectrode for brain recordings is described. Its hollow-core structure and slightly recessed contacts allow the electrode to be guided with a central stylet for minimal tissue trauma. The helical design of the electrode is characterized by high fatigue resistance and high flexibility allowing movement with the brain and preventing slicing through tissue. Clinical results have been obtained on epileptic patients.

[Treatment of recurrent congenital ocular toxoplasmosis. Our initial experience with Fansidar]. / Traitement de la toxoplasmose oculaire congénitale à rechutes. Notre première expérience du Fansidar.

Congenital ocular toxoplasmosis with recurrences must be treated by Spiramycin destroys trophozoites when they escape from the true cysts. Fansidar (Pyrimethamine + Sulfadoxine) seems to have less efficacity than Pyrimethamine with Sulfadiazine.

[Not Available].

Summary To detect a foreign collagen in a tissue on a substantially idemtied protein, a radio-tracer technique appeared ideal. The method is only valuable if the introduction of the tram element into the micro molecule does not modify its properties. The first collagen used was tagged by the introduction of C1* into the peptide chain from marked proline by biosynthesis. A 0.3% concentration in sorbic acid solution was applied to the back of the animal and the penetration followed by measuring the activity of tissue sections. No radioactivity was found in the interior of the deinnir after periods of 15, 30,90 and 120 min after application. The method of biosynthetic marking was abandoned as the activity of the protein was considered to be insufficient. The technique of the incorporation of 1(125) in the tyrosine was used to obtain a greater specific activity without modifying the active principle. This chemical treatment resulted from the oxidation of tagged iodide in the presence of collagen. The protein was purified by chromatography and successive dialyses and diluted in unlabelled collagen for subsequent manipulation. Skin applications were made in sorbic acid solution at 0.3% and at 10% in a cosmetic cream. Skin penetration forthe same periods as previously were followed by the same sectionning technique. The penetration reached a maximum at the end of 15 min and was greater for the cream than for the solution. Metabolic studies showed that 15 days after application the residual radioactivity was present mainly in the lymphatic glands and in the skin. Treated dcin showed more activity than untreated areas. At the end of 10 days the excretion of radioactivity had dropped to very low levels. Chromatography on molecular sieve of the collagen extracted from the deeper layers on the skin indicated that the largest part of the radio-activity originated in peptide chains.

[In vivo blood histamine during anesthesia]. / Etude de l'histaminémie in vivo pendant l'anesthésie

Assays of overal histaminaemia were carried out, in 150 patients anaesthetised according to three different techniques, apart from any surgical act. 119 anaesthesias took place without any incident, 33 were disturbed by the appearance of rashes or of bronchospasm. The overall histaminaemia varied according to three types of graphs (a flat graph, an ascending graph, or a descending graph) without it being possible to evoke any relationship between this course and the clinical signs. It seems that the presence of a background predisposing to histamine-liberation is however responsible for greater frequency of the descending graphs, and that the method of administration of the anaesthetic product is a factor which can intervene in the genesis of the phenomena of histamine-liberation during anaesthesia. An interpretation of the variations in the graphs of histaminaemia is attempted by the authors.

A microelectronic pH sensor.

This paper presents preliminary data on a new integrated circuit microelectronic pH sensor. The device is extremely miniaturized by the use of integrated circuit technology, and uses the intrinsic hydrogen ion selective properties of the gate insulator material. In order to make the device compatible with aqueous solution monitoring, the silicon dioxide-silicon nitride gate insulator structure is used. The integrated circuit chip was designed, processed, and packaged by a variety of techniques which protect all metal parts from the aqueous solution. Test data are reported on leakage current, sensitivity, reproducibility, linearity, stability, response time, and life. The results indicate that this type of pH sensor may have many significant advantages for biomedical research and application.