TEM investigations on the local microstructure of electrodeposited galfenol nanowires.

The local microstructure of Fe-Ga nanowires is investigated considering dependence on the deposition technique. Using a complexed electrolyte, smooth and homogeneous Fe80Ga20 nanowires are deposited into anodic aluminum oxide templates by either applying pulse potential or potentiostatic deposition technique. At optimized deposition conditions the wires show the desired composition of Fe80±2Ga20±2 without a gradient along the growth direction. Composition distribution, structure and microstructure are examined in detail and reveal only minor differences. Line EELS and crystal lattice measurements reveal a negligible oxygen content for both preparation routines. Neither Fe/Ga oxides nor hydroxides were found. Both potentiostatically deposited as well as pulse deposited nanowires exhibit a preferred 〈110〉orientation, the latter with slightly larger crystals. Different contrast patterns were found by TEM that appear more pronounced in the case of pulse deposited wires. High resolution transmission electron microscopy analysis and comparison of differently prepared focused ion beam lamellas reveal that these contrasts are caused by defects in the alternating potential deposition itself and are not induced during the TEM preparation process. The alternating potential mode causes periodic growth thereby inducing different layers with reduced wire thickness/defects at the layer interfaces.

Synthesis of silver nanoparticles in melts of amphiphilic polyesters.

The current work presents a one-step procedure for the synthesis of amphiphilic silver nanoparticles suitable for production of silver-filled polymeric materials. This solvent free synthesis via reduction of Tollens' reagent as silver precursor in melts of amphiphilic polyesters consisting of hydrophilic poly(ethylene glycol) blocks and hydrophobic alkyl chains allows the production of silver nanoparticles without any by-product formation. This makes them especially interesting for the production of medical devices with antimicrobial properties. In this article the influences of the chain length of the hydrophobic block in the amphiphilic polyesters and the process temperature on the particle size distribution (PSD) and the stability of the particles against agglomeration are discussed. According to the results of spectroscopic and viscosimetric investigations the silver precursor is reduced to elemental silver nanoparticles by a single electron transfer process from the poly(ethylene glycol) chain to the silver ion.

[Reliability of pulsatile saturometry in patients with shock. Digital standard sensors are not reliable for facial measurement!]. / Fiabilité de la saturométrie pulsée chez les patients en état de choc. Les capteurs digitaux standard ne sont pas fiables sur les sites faciaux !

INTRODUCTION: Non-invasive monitoring of oxygen saturation by pulse oxymetry (SpO(2)) is sometimes perturbed on fingers during shock states. Other sites are possible (toes, forehead, nose, ear). Self-adhesive standard digital sensors are commonly used off-label in these sites. We have assessed their reliability for all of these sites. METHODS: We have studied patients presenting a stabilized shock state and receiving vasoconstrictive catecholamines. When an arterial blood gas was ordered, six SpO(2) were measured quasi-simultaneously (self-adhesive standard sensors): right and left index, toe, forehead, nose and ear. SpO(2) at "finger", "toe", "forehead", "nose" and "ear" were compared to the arterial oxygen saturation (SaO(2)) by using the Bland and Altman method. The plethysmographic curve was assessed as "correct" or "unsatisfactory". RESULTS: Hundred and ten patients were included (63 ± 15 years, SAPSII 46 ± 16, catecholamines: 0.6 ± 0.5 µg/kg/min). Plethysmographic curves are more often of "correct" quality for fingers (90%) than for the other locations (50 to 70%). Bias are low for all the locations (-0.1 to +1.5%). Limits of agreement are around ±5% for fingers and toes, but as high as ±15% for the face locations. When the analysis is restricted to plethysmographic curves of "good" quality, the limits of agreement are unchanged for fingers and toes, but improved (between ±5 to ±10%) for face locations. CONCLUSION: In patients with a shock receiving vasoconstrictive catecholamines, the reliability of SpO(2) measurements with standard sensors appears better for fingers than for toes and face locations. These standard sensors should be discouraged for facial measurement because of their low reliability, even when the plethysmographic curve seems correct. Sensors specifically designed for each facial site exist, and their reliability should be estimated in patients receiving vasoconstrictive catecholamines.

Mechano-chemical radical formation and polymerization initiation during wet grinding of alumina.

The formation of free radicals during wet grinding of alumina in a stirred media mill was studied by using the test radical 2,2-diphenyl-1-picrylhydracyl (DPPH). The kinetics of mechano-chemical radical formation follows a zeroth-order rate law. Particle breakage as well as mechanical activation of the surface of the alumina particles contributes to the radical formation. The rate constants of the radical formation due to mechanical activation of the particle surface k(A) and due to particle breakage k(B) depend on the milling process parameters. The radical formation during wet grinding of alumina was exploited to initiate mechano-chemical polymerization reactions of acrylic acid and acryl amide, respectively. In this way nanoparticles functionalized with polyacrylic acid and polyacryl amide, respectively, are obtained. The influence of the milling process parameters on the kinetics of mechano-chemical radical formation and on the grafted amount of polymer is discussed on the basis of stress energy and number of stress events in the mill. A correlation between the grafted amount of polyacryl amide on the alumina particles and the total radical formation rate was found showing that the concentration of mechano-chemically formed free radicals governs the efficacy of a chemical reaction at activated particle surfaces.

[Management of a catheter-induced rupture of a pulmonary artery]. / Vorgehen bei einer katheterinduzierten Pulmonalarterienperforation.

HISTORY AND ADMISSION FINDINGS: A 72-year-old woman presented with progressive dyspnea on exertion. There was no chest pain. A 4/6 systolic murmur was detected on auscultation. INVESTIGATIONS: Echocardiography demonstrated a combined aortic valve defect with severe stenosis and moderate insufficiency, additionally a persistent foramen ovale. The coronary angiography revealed coronary heart disease with severe stenosis of the left anterior descending (LAD) and the right coronary artery (RCA). The stenosis of the aortic valve was severe (Pmax 91 mm Hg, Pmean 52 mm Hg). During catheterization of the right heart iatrogenic perforation of a pulmonary artery occurred, resulting in diffuse pulmonary bleeding. The patient suffered from progredient dyspnea and hemoptysis. DIAGNOSIS, TREATMENT AND COURSE: Catheter-induced rupture of an artery of the right inferior pulmonary lobe was diagnosed. Because of bleeding into this lobe an immediate intubation with a double-lumen bronchial tube was necessary to ensure ventilation of the contralateral lung. Several attempts to occlude the arterial leak by ballon failed. Bleeding stopped after embolisation of the vessel by injection of thrombin. CONCLUSION: Iatrogenic rupture of a pulmonary artery is a rare and life-threatening complication of the catheterization of the right heart and demands rapid therapy. The protection of the contralateral lung by intubation with a double-lumen tubes is of highest priority. Selective embolization of the affected vessel via thrombin can be a lifesaving alternative to lobectomy or conservative therapy.

Kinetics of radical formation during the mechanical activation of quartz.

The kinetics of radical formation during the mechanical activation of quartz by wet grinding or sonication was investigated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) as a scavenger. The consumption of DPPH during the sonication of quartz in an ethanol suspension is a zeroth-order process. A linear relationship between the rate constant of the DPPH consumption and the quartz concentration in the suspension indicates that radical formation under sonication increases with the growing total surface area of the quartz particles. Sonication leads to the formation of free radicals by the mechanical activation of the particle surface. The kinetics of the DPPH consumption during wet grinding of quartz in a stirred media mill is described successfully by a modified zeroth-order rate law taking the total surface area of the quartz particles into account. The surface-normalized rate constant of the DPPH consumption decreases from 1.8x10(-7) mol L(-1) h(-1) m(-2) to 4.8x10(-8) mol L(-1) h(-1) m(-2) if the specific surface area of the feed material increases from 0.5 to 84 m2/g. This finding indicates that the breakage of the quartz particles contributes much more to radical formation than does the mechanical activation of the particles in the mill because the breakage rate increases with growing particle diameter. Ethanol but not DPPH was found on the surface of the ground quartz particles. From this finding, it can be concluded that radicals on the surface of the quartz particles react with ethanol, leading to the formation of ethanol radicals and H radicals. DPPH reacts with the H radicals. As a side reaction, radicals can react with oxygen, leading to the formation of peroxides.

[Impact of Sfar experts' conference entitled "Modalities of sedation and/or analgesia in hospital setting"]. / Impact de la conférence d'experts intitulée "Modalités de la sédation et/ou de l'analgésie en situation extrahospitalière".

UNLABELLED: In 1999, the Société française d'anesthésie et de réanimation (Sfar) published guidelines regarding sedation in prehospital setting. The recommendated protocol for emergency intubation was the rapid sequence induction (RSI). The aim of this study was to assess the impact of these guidelines on clinical practices. PATIENTS AND METHODS: A restrospective observational study was conducted in three French mobile emergency and intensive care units. In 1998, 2000 and 2004, during periods of four months, charts from every interventions were analyzed. All the patients over 15 years of age needing to be intubated and not in cardiac arrest were included. The following data were collected: anaesthetic protocol used for intubation, drugs used for maintenance of sedation, circumstances requiring tracheal intubation and side effects related to tracheal intubation or sedation. An anonymous questionnary form was also sent to all physicians from the three units in order to assess sedation protocol used for emergency intubation, knowledge regarding the Sfar conference. RESULTS: Five hundred and thirty-one patients were included, and orotracheal intubation was performed in 84% of cases. RSI was administrated in 23% of cases in 1998, 45% in 2000 and 68% in 2004. Protocol for maintenance sedation complied the guidelines in 45% of cases in 1998, 68% in 2000 and 75% in 2004. Among the 62 physicians who answered the questionnary, 90% indicated they used RSI sequence for orotracheal intubation and 92% achieved sedation maintenance using midazolam fentanyl. CONCLUSION: The Sfar guidelines regarding sedation in prehospital setting seem to meet a good compliance in clinical practice.

[Complications during the intrahospital transport in critically ill patients]. / Complications durant le transport intrahospitalier de malades critiques de réanimation.

INTRODUCTION: Intrahospital transport (IHT) of mechanically ventilated critically ill patients is associated with an important risk of complications. OBJECTIVES: The purpose of this study was to assess the incidence of complications occurring during the IHT and to analyse the causes and the consequences of such complications. PATIENTS AND METHODS: All the IHT performed in mechanically ventilated patients, hospitalised in medical and surgical intensive care units of a university hospital were prospectively included during a three-month period. Complications were defined as follows: patient related problems (desaturation, restlessness, haemodynamic instability, extubation) and ventilator related problems (breakdown or defect of the material). RESULTS: 123 IHT concerning 64 patients were analysed, with 64 IHT were realised for diagnostic procedure (computed tomography) and 59 for therapeutic procedure (surgical procedure or interventional radiology). At least one patient related problem occurred during 41 IHT (33%) (desaturation n = 11, agitation n = 21, haemodynamic alterations n = 19, extubation n = 0). In two patients, these complications led to cardiac arrest. Patient related problems were observed more frequently in sedated patient (66 %, p = 0.0001) as well as during IHT for diagnostic procedure (p = 0.03). A ventilator problem occurred in 26 transports (21 %) and was more frequently reported when a turbine ventilator was used (p = 0.0056). CONCLUSION: This study supports the fact that IHT of mechanically ventilated critically ill patients, is a high-risk procedure associated with potentially severe complications. This finding emphasises the need of standardised procedures and medical surveillance during IHT.

Transarterial aortic valve replacement with a self expanding stent in pigs.

OBJECTIVES: To evaluate the feasibility of percutaneous aortic valve replacement without cardiac arrest in animal experiments. METHODS: A self expanding nitinol stent, containing pulmonary valves from pigs in its proximal part, was implanted in six pigs (94-118 kg) by means of a 25 French catheter through the left subclavian artery under guidance of fluoroscopy and transoesophageal echocardiography. During stent deployment the original aortic valve was pushed against the aortic wall by the self expanding force of the stent while the new valve was expanded. RESULTS: It was possible to replace the aortic valve in the beating heart in four pigs (67%) with no complication or relevant drop in blood pressure. The procedure failed in two pigs (33%) due to dysfunction of the catheter device in one case and to problems with correct positioning in the left ventricular outflow tract in the other. After successful stent valve implantation, dopamine was infused in doses of 5 microg/kg/min, 10 microg/kg/min, and 15 microg/kg/min. Cardiac output increased from 4.4 to 8.8 l/min and the mean arterial pressure rose from 79 to 105 mm Hg. The maximum peak to peak pressure gradient across the valve carrying stent reached a maximum of 8 mm Hg under dopamine infusion. All pigs were killed six hours after transvascular aortic valve replacement. The chest was opened, and the left ventricle and the ascending aorta were carefully inspected. There were no signs of malfunction of the implant, of damage of the aortic vessel wall, or of obstruction of the coronary ostia. CONCLUSIONS: Percutaneous aortic valve replacement with a self expanding nitinol stent in the beating heart is possible. The device was safe under pharmacological stress test. After successful chronic animal experiments, this concept may become a feasible option for treating patients with relevant aortic valve disease but where open heart surgery would be risky.

Effect of keratinocyte growth factor on the proliferation, clonogenic capacity and colony size of human epithelial tumour cells in vitro.

PURPOSE: The effect of recombinant human keratinocyte growth factor (rHuKGF) on the proliferation, clonogenic capacity and colony size of low-passage human epithelial tumour cells was tested in vitro. MATERIALS AND METHODS: Five tumour cell cultures derived from head and neck squamous cell carcinomas, three cultures derived from pleural effusions of carcinomas of different origin and normal human nasal epithelial cells were analysed in passages 2-4. Expression of FGF7 and its receptor (FGFR2) were determined by the RNase protection assay. Cells were incubated with rHuKGF (10-200 ng ml(-1)) 3 days before or immediately after plating for clonal growth in serum-depleted media. To determine cellular radiosensitivity, single doses of 1-8 Gy X-rays were applied. Colony formation as well as colony size, reflecting the number of cell divisions, was determined after 10-15 days of growth in rHuKGF-treated and control cells. RESULTS: Normal nasal epithelial cells showed a two- to threefold increase in the number of cell divisions due to rHuKGF-treatment. In tumour cell cultures, significant stimulation of proliferation occurred in only one of eight samples. Tumour cells expressed FGF7 mRNA and protein, and low levels of FGFR2 mRNA. The addition of rHuKGF to the medium of the tumour cell cultures influenced neither radiation-induced impairment of proliferation nor clonogenic cell survival. CONCLUSION: rHuKGF has been shown to ameliorate the radiation tolerance of normal epithelia. The minimum in vitro tumour cell response to rHuKGF compared with normal epithelial cells suggests a potential for selective protection of normal epithelia during radiotherapy. The low FGFR2 expression as well as the FGF7 expression in the tumour cells may contribute to their resistance to rHuKGF treatment.

Excimer laser fragmentation-fluorescence spectroscopy as a method for monitoring ammonium nitrate and ammonium sulfate particles.

Excimer laser fragmentation-fluorescence spectroscopy (ELFFS) is shown to be an effective detection strategy for ammonium nitrate and ammonium sulfate particles at atmospheric pressure and room temperature. Following photofragmentation of the ammonium salt particle, fluorescence of the NH fragment is observed at 336 nm. The fluorescence signal is shown to depend linearly on particle surface area for laser intensities varying from 1.2 x 10(8) to 6 x 10(8) W/cm2. The 100 shot (1 s) detection limits for ammonium nitrate range from 20 ppb for 0.2 microm particles to 125 ppb for 0.8 microm particles, where these concentrations are expressed as moles of ammonium ion per mole of air. For ammonium sulfate, the 100 shot (1 s) detection limits vary from 60 ppb for 0.2 microm particles to 500 ppb for 1 microm particles. These detection limits are low enough to measure ammonium salt particles that form in the exhaust of combustion processes utilizing ammonia injection as a nitric oxide control strategy.

Independent regulatory elements in the upstream region of the Drosophila beta 3 tubulin gene (beta Tub60D) guide expression in the dorsal vessel and the somatic muscles.

The beta 3 tubulin gene (beta Tub60D) is a structural gene expressed during mesoderm development from the extended germ band stage onward. Expression within the individual mesodermal derivatives is guided by different control elements. The upstream regions allow expression in the dorsal vessel and the somatic mesoderm while enhancers localized in the first intron guide expression in the visceral mesoderm. Deletion analysis carried out in transgenic flies revealed independent regulatory elements for the dorsal vessel and the somatic mesoderm. For expression in the somatic mesoderm, a 279-bp region is absolutely essential. This region contains a binding site for the Drosophila myocyte-specific enhancer binding factor 2 (D-MEF2), a MADS-box transcription factor known to be essential for mesoderm development. Deletion or mutation of this D-MEF2 binding site strongly reduces transcription. This pattern is consistent with the strongly reduced expression of beta 3 tubulin in D-mef2 mutant embryos. This analysis furthermore reveals that the D-MEF2 binding site acts in concert with nearby cis regulatory elements. These data show that the upstream control region of the beta 3 tubulin gene is an early target of the D-MEF2 transcriptional activator.

Ammonia detection and monitoring with photofragmentation fluorescence.

Excimer laser fragmentation-fluorescence spectroscopy is an effective detection strategy for NH(3) in combustion exhausts at atmospheric pressure and high temperatures. Two-photon photofragmentation of NH(3) with 193-nm light yields emission from the NH(A-X) band at 336 nm. There are no major interferences in this spectral region, and the sensitivity is at the parts per billion (ppb) level. Quenching of the NH(A) state radical by the major combustion products is measured and does not limit the applicability of the detection method. Detection limits in practical situations are of the order of 100 ppb for a 100-shot (1-s) average. This technique could prove useful in monitoring ammonia emissions from catalytic and noncatalytic NO(x) reduction processes involving ammonia injection.

The mesodermal expression of rolling stone (rost) is essential for myoblast fusion in Drosophila and encodes a potential transmembrane protein.

In homozygous rolling stone embryos, the fusion of myoblasts to syncytial myotubes is diminished. Nevertheless, the visceral mesoderm, the heart mesoderm, and few somatic muscles are properly formed. Thus, we postulate a central role of rolling stone for the fusion process within the somatic mesoderm. We have cloned the rolling stone gene, and the deduced protein sequence is in accordance with a transmembrane protein, which agrees with the enrichment of Rost in the membrane fraction of Drosophila embryos. No homologous genes have been described so far. rolling stone is expressed in the embryonic nervous system and cells of the somatic mesoderm, most notable in muscle founder cells. To elucidate the function of rolling stone for myoblast fusion, we applied a knock-out strategy. The expression of an antisense rolling stone transcript specifically within the mesoderm of wild-type embryos results in fusion defects of myoblasts, proving that the rolling stone expression in the mesoderm is responsible for the rolling stone phenotype. We suggest that rolling stone is a member of a group of genes that are necessary for the fusion process during myogenesis.

Computer-assisted mapping of infarcted and viable regions of gross cardiac sections following experimental myocardial infarction.

We have developed a computer-assisted method that creates digital maps of the viable and infarcted regions of tetrazolium-stained gross cardiac sections. Here we describe and test the method, using a canine occlusion-reperfusion infarction model. Quantitative image analysis showed that the method accurately recorded differences between infarcted and viable regions at a spatial resolution of 5-20 pixels per mm2. Microscopic analysis of tissue samples taken from the sections showed that the maps were accurate. In 15 of 15 cases the histology of the samples matched that predicted by the maps. A comparison of infarct area measurements derived from the maps showed that the method was reproducible. The average intraoperator standard deviation was +/- 8% of a slice's infarcted area and the average interoperator standard deviation was +/- 20%. We conclude that the method creates accurate, detailed, and reproducible maps of the infarcted and viable regions of tetrazolium-stained cardiac sections.

Concurrent radiation therapy, 5-fluorouracil, and cisplatin for stage II, III, and IV, node-negative, squamous cell head and neck cancer. Results and surgical implications.

METHODS: Between 1983 and 1989, 42 patients with Stage II, III, and IV, node-negative, squamous cell head and neck cancer were treated with concurrent 5-fluorouracil, cisplatin, and radiation therapy. Two courses of chemotherapy with 30 Gy of concurrent radiation therapy were to be followed in all patients by definitive surgery and then an additional 30 Gy of radiation therapy and one to two courses of chemotherapy. The patients who achieved a complete response to the initial induction treatment, however, did not undergo surgery. RESULTS: After the completion of all therapy, 41 of the 42 patients (98%) were considered disease-free. Only 4 of these 41 had relapses, for a projected Kaplan-Meier disease-free survival rate of 86%. Treatment failure occurred in no patients with Stage II, 1 of 17 patients with Stage III, and 4 of 14 patients with Stage IV disease. Of the 42 patients, 23 (55%) did not require surgery after achieving a complete response to induction therapy, and only 1 of these 23 patients subsequently had a relapse. CONCLUSIONS: Although the value of adding chemotherapy to conventional treatment remains unproven in squamous cell head and neck cancer, this treatment schedule appears promising in node-negative disease. Randomized trials will be necessary, however, to validate the efficacy of this approach and confirm the suggestion by the authors that surgery can be avoided in most patients with N0 disease.

Long-term results after chemoradiotherapy for locally confined squamous-cell head and neck cancer.

The long-term results after simultaneous chemoradiotherapy in 54 patients with previously untreated or minimally treated, locally confined (M0) squamous-cell carcinoma of the head and neck are presented. Multiple concurrent courses of radiation therapy and chemotherapy with cisplatin and a four-day 5-fluorouracil infusion were given. Twenty-eight patients underwent definitive surgery and 26 were treated without surgical resection. Treatment-associated toxicity was significant, including mucositis, myelosuppression, and a mean 12% loss of initial body weight. Of the 54 patients, 51 were ultimately rendered disease free by this combined modality protocol. With a follow-up ranging from 42-68 months, the projected Kaplan-Meier relapse-free survival for the entire patient cohort is 70%, with all relapses occurring within 17 months of patient entry. The projected Kaplan-Meier relapse-free survival for patients with Stage IV disease is 62%. The durability of these remissions suggests that there is a significant likelihood of cure in all patients with locally confined disease, and justifies comparative trials with standard treatment.

Simultaneous versus sequential combined technique therapy for squamous cell head and neck cancer.

Forty-eight patients with locally confined (M0) squamous cell head and neck cancer were prospectively randomized to receive either simultaneous (SIM) or sequential (SEQ) combined technique therapy with a 5-fluorouracil infusion, a cisplatin bolus injection, and radiation therapy. Patients with residual resectable disease underwent surgery after induction therapy, whereas those achieving a complete response to induction did not require surgery. Patients on the two treatment arms were equivalent in all measured variables, including disease extent. Toxicities of the SIM and SEQ arms also were equivalent except for mucositis and the resultant weight loss, which were more severe on the SIM arm (P = 0.002). With a follow-up time ranging from 9 to 41 months, seven of the 24 SIM patients and 14 of the 24 SEQ patients are considered treatment failures. The relapse-free survival is significantly better on the SIM arm (P = 0.03), although an overall survival advantage has not yet been demonstrated (P = 0.13). The achievement of a complete response after induction therapy correlates with both the relapse-free (P = 0.0005) and overall (P = 0.05) survival, and the likelihood of an induction complete response also is significantly better for those treated with the SIM schedule (P = 0.02). Eighteen patients did not require surgery after achieving an induction complete response. Relapse-free survival does not appear to be compromised in this patient subset.

Simultaneous radiotherapy and chemotherapy with 5-fluorouracil and cisplatin for locally confined squamous cell head and neck cancer.

Fifty-four patients with previously untreated or minimally treated locally confined (MO) squamous cell carcinoma of the head and neck were treated with chemoradiotherapy employing multiple courses of simultaneous radiation, cisplatin, and a 4-day 5-fluorouracil infusion. Twenty-eight patients subsequently underwent definitive surgery, and 26 were treated without surgical resection. Of the 54 patients, 51 were ultimately rendered disease free by this combined modality protocol. The projected relapse-free survival rate for the entire cohort is 71%, with a median relapse-free survival time greater than 17 months. Thirteen patients who had tumors that were technically operable did not undergo surgery after achieving a complete response to induction chemoradiotherapy. Only 1 of these patients experienced subsequent local failure. Although the treatment-associated mucositis and local failure. Although the treatment-associated mucositis and myelosuppression were significant, this chemoradiotherapeutic protocol offers a significant chance of relapse-free survival for all patients with locally confined disease and merits comparison with more standard treatment approaches.