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Homogeneous ultra thin silicon nitride layers (SiN x layers) close to the surface have been produced by 10 keV 15 N 2 + molecular ion implantation and an ion current density of 10 μA/cm 2 , into single crystal silicon at room temperature. Stoichiometric SiN x layers with thicknesses of about 28 nm (analyzed by NRA) were obtained at fluences of 1.5 x 10 17 at/cm 2 . NRA anlayses of samples annealed by EB-RTA at T = 1150°C for 15 s indicated that the N/Si ratio and the layer thickness did not change drastically. FT IR ellipsometry analyses indicated the existence of Si 3 N 4 bonds in as-implanted specimens. A disordered Si layer (d-Si, typically 15 nm thick) underneath the implantation region caused by the ion implantation was found by channeling RBS analyses. The d-Si layer partly recrystallized during EB-RTA showing a thickness of 6 nm afterwards. The SiN x layers showed no decomposition and detachment after EB-RTA. Due to EB-RTA, however, the smooth surface of the as-implanted specimens changed into a surface with remaining whisker-like structures surrounded by circular recesses as shown by AFM analyses. A model for the growth of these whisker-liker structures caused by low energy ion implantation and EB-RTA is presented on the basis of the thickness of the SiN x layer, the existence of the d-Si layer and the special annealing process.

We report radio frequency (rf) electrical readout of graphene mechanical resonators. The mechanical motion is actuated and detected directly by using a vector network analyzer, employing a local gate to minimize parasitic capacitance. A resist-free doubly clamped sample with resonant frequency ~ 34 MHz, quality factor ~ 10000 at 77 K, and signal-to-background ratio of over 20 dB is demonstrated. In addition to being over two orders of magnitude faster than the electrical rf mixing method, this technique paves the way for use of graphene in rf devices such as filters and oscillators., 10 pages, 2 figures

The education of medical professionals is divided into medical studies, postgraduate training leading to the qualification as a specialist, and continuing professional development. During education, all scientific knowledge and practical skills are to be acquired, which enable the physician to practice responsibly in a specialized medical area. In the present article, relevant curricula are analyzed regarding the consideration of medical device-related topics, as the clinical application of medical technology has reached a central position in modern patient care. Due to the enormous scientific and technical progress, this area has become as important as pharmacotherapy. Our evaluation shows that medical device-related topics are currently underrepresented in the course of medical education and training and should be given greater consideration in all areas of medical education. Possible solutions are presented.

Autologous ear cartilage is relatively easy to procure in suitable form and sufficient quantity. At the donor site, there are, as a rule, no complications to be expected. Autologous ear cartilage without conjunctival coverage is of good use for replacing and lengthening the inner layer of an eyelid, not only to reconstruct large eyelid-defects, but also to give additional support and length. The cartilage graft will grow on well, provided the wound is well vascularized. This must not be expected with scarring or poor blood perfusion. The brittleness of the cartilage demands an adapted technique. Precautions to protect the cornea and to prevent adhesions in the fornix are to be taken.

The electrical and geometric properties of GaAs multilayer structures are measured nondestructively by infrared reflectance spectroscopy (50–5000 cm−1). Using oblique incidence and both s- and p-polarizations of the probing beam, carrier concentration and thickness of the epitactic films as well as the carrier concentration of the GaAs substrate are determined. The main structures in the spectra are due to phonon reststrahlen bands, Fabry-Perot interferences and the zeros of the dielectric function leading to dips in the reflectance (Berreman Mode). The results compare favorably with a depth-resolved secondary ion mass spectrometric (SIMS) sample analysis. The range of applicability of the method is discussed.

A 46-year-old man presented two hours after ingestion of about 250 mg strychnine with severe violent, generalized convulsions, triggered by external stimuli. During the convulsion-free periods there were no abnormal signs in the physical examination.The presence of strychnine was confirmed by urine analysis with gas chromatography-mass spectrometry.Because diazepam as anticonvulsant of choice was not effective in abating the convulsions the patient was intubated. A combination with midazolam, fentanyl and pancuronium was effective in controlling the convulsions. The patient was discharged from ICU on day three.Fatal outcome of strychnine poisoning demands an aggressive management with early intubation, control of muscle tremors and prevention of rhabdomyolisis and renal failure.

Der Aufbau des Kapitels „Rechtsgrundlagen“ orientiert sich an der Frage: „Was soll mit dem Baggergut passieren?“ und stellt die bei der jeweiligen Ablagerungsart relevanten Rechtsgrundlagen dar. Diese Darstellung beschrankt sich in erster Linie auf die erforderlichen Genehmigungen. Welche weiteren rechtlichen Regelungen im Zusammenhang mit der jeweiligen Genehmigung zu beachten sind, ist eine Frage des Einzelfalls. Eine vom Einzelfall losgeloste, abstrakte Darstellung aller weiteren in Betracht kommenden Rechtsgrundlagen ist im Rahmen dieser Arbeit nicht leistbar, zumal es sich im wesentlichen um landesrechtlich geregelte Genehmigungsverfahren handelt. Insofern konnen lediglich einige grundlegende, ubergreifend anwendbare weitere Rechtsgrundlagen dargestellt werden.

Indirekte Zwerchfellrupturen (ZR) sind erworbene, komplette Durchtrennungen des Diaphragmas nach stumpfer Gewalteinwirkung und treten bei etwa 1–5% aller polytraumatisierten Patienten auf. Die Diagnose ist nicht immer einfach, bestimmte Unfallmechanismen und Verletzungsmuster konnten jedoch auf das Vorliegen einer ZR deuten. Auffallig war bei unserer retrospektiven Analyse (17 Falle, 1993–1999) die Kombination mit Beckenfrakturen und Gurttragern (64%). Rechtsseitige ZR (35%) waren haufig, eine „Schutzfunktion der Leber“ liegt also nicht vor. Bei beatmeten Patienten kann der Riss bis zur Extubation unentdeckt bleiben. Bei komplexen Polytraumen sollte eine ZR immer ausgeschlossen werden, am sichersten durch eine CT mit oraler KM-Gabe. Der Zugang sollte wegen der haufigen Begleitverletzungen von abdominell erfolgen.

Sinorhizobium meliloti 1021 responds to external biotin signals from alfalfa plants through the bioS regulatory locus. Immunogold labeling and electron microscopy revealed that the BioS protein is located within the S. meliloti cytoplasm. Under biotin-limiting conditions the S. meliloti cell lumen was filled with polyhydroxybutyrate (PHB) granules suggesting that either PHB synthesis or degradation are influenced by biotin. To test this hypothesis a 3-hydroxybutyrate-dehydrogenase-lacZ (bdhA-lacZ) fusion was mobilized into S. meliloti. beta-galactosidase tests revealed an overall 3.6-5.2-fold higher bdhA transcription in the presence of added biotin. Comparison of the bdhA and the bioS promoter regions identified several common motifs.

Sinorhizobium meliloti 1021 produces biotin required for growth, but it also responds to external biotin signals from alfalfa plants through the bioS regulatory locus. Mutation of bioS increases biotin uptake, extends stationary phase in the presence of biotin, and impairs competitive growth in the presence of biotin. New data supporting the relevance of this gene to plant-microbe interactions show that a bioS-gusA reporter fusion is expressed by bacteria on plant roots, by bacteria in alfalfa root nodules, and more generally by any stationary-phase bacterial cells in the presence of biotin. Significant transcription of bioS-gusA was detected at 50 pM biotin, and a 16-fold induction was measured in stationary-phase cells with 1 nM biotin. A positive autoregulation of bioS is suggested by the fact that, in the presence of 10 nM biotin, a bioS-gusA fusion in wild-type cells was transcribed at more than twice the rate of the same reporter fusion in a bioS mutant background. Analyses of primer extension products and expression studies with three different bioS-gusA promoter fusions defined major characteristics of the bioS promoter. Expression of bioS in Escherichia coli resulted in the production of a 35-kDa BioS protein with characteristics of an LysR-type regulator. Those traits included a deduced amino acid sequence containing possible helix-turn-helix DNA-binding structures and three T-N (11)-A motifs upstream from the bioS gene. A regulatory role for BioS protein was supported by tests showing that a 321-bp DNA fragment containing the bioS promoter altered the electrophoretic mobility of recombinant BioS and of a corresponding band in protein extracts from S. meliloti 1021. The absence in BioS of any significant homology to known amino acid sequences was consistent with the fact that DNA hybridization tests with seven genera of bacteria detected bioS only in Sinorhizobium.

The purpose of this study was to analyze the therapy concept used in the management of severe epistaxis in order to optimize the quality of our treatment and to arrive at an optimal therapeutic concept.The study was performed as a retrospective analysis of the charts of all 335 patients treated as inpatients for epistaxis over a period of 6 years.An increased rate of complications was found in the following three situations: 1. Age65 years, 2. chronic obstructive pulmonary disease, 3. several systemic illnesses. Recurrence was increased with septal perforations and Osler's disease.Localization of the site of bleeding is the first priority and allows treatment of bleeding with bipolar electrocautery. If the bleeding vessel is not found, insertion of a Merocel pack is recommended. Patients with persistent or recurrent bleeding are treated in the operating theater under general anesthesia if they are at an elevated risk for complications or have a septal deviation which is clinically significant. The nose is systematically visualized with the endoscope, bleeding vessels are coagulated under endoscopic control, and, where appropriate, a septoplasty is performed. In the remaining cases an epipharynx balloon is inserted, combined with an anterior pack. Angiography with superselective embolization, external ligation of the ethmoidal arteries, and endonasal obliteration of the sphenopalatine artery is reserved for cases where the measures discussed above have failed.

Wir wissen, das Ruckenbeschwerden heutzutage in Industriestaaten ein weit verbreitetes Problem darstellen mit einer spurbaren Zunahme im Verlauf der letzten Jahrzehnte, auch abhangig von einer beruflichen Belastung. Die meisten verfugbaren epidemiologischen Daten betreffen die Pravalenz von Beschwerden an der LWS und stammen aus Fallstudien. An wenigen, der Ubersichtsarbeit von Andersson entnommenen Zahlen beispielhaft aufgezeigt ergibt sich folgendes Bild [1]: in Europa bestehen 10–15% der Arbeitsunfahigkeitszeiten aufgrund von Ruckenbeschwerden, die Einjahrespravalenz betragt 25–45%, chronische Ruckenbeschwerden findet man bei 3–7% der erwachsenen Bevolkerung, die lebenslange Pravalenz fur Ruckenbeschwerden in Industriestaaten betragt mehr als 70%: 25% davon als Ischialgie, 1–2% als Bandscheibenvorfall.

The usefulness of splinting of severely loosened teeth in advanced periodontitis has been discussed extensively, both positively and negatively. Retention of patients own teeth through the aid of this simple and inexpensive resin composite splint provides a satisfactory solution for many affected patients. The fabrication and placement techniques for splints for the anterior and posterior regions are described, as are additional indications for such splints, which are fabricated from resin composite and glass fiber bundles. Such splinting can be provided even for severely loosened, periodontally diseased teeth without danger of intraoperative tooth loss. Long-term retention of such teeth can be ensured only through a risk-oriented postoperative program of oral hygiene and regular examination of the splint.

The GaAs(110) surface was exposed to normal-incidence ${\mathrm{Ar}}^{+}$ ion bombardment at energies ranging from 200 eV to 3 keV. The structural, electronic, and compositional modifications induced were monitored by low-energy electron diffraction, electron energy-loss spectroscopy (EELS), and by Auger-electron spectroscopy for different flux densities, accumulated fluences, and specimen temperatures. The fluences necessary for the amorphization of the near-surface region at room temperature amount to some 1\ifmmode\times\else\texttimes\fi{}${10}^{15}$ ${\mathrm{Ar}}^{+}$/${\mathrm{cm}}^{2}$ and increase both with decreasing flux density and with decreasing impact energy, the latter effect being very pronounced below 1 keV. The alterations of the electronic states as inferred from EELS exhibit a similar fluence dependence but are less sensitive to the bombardment energy. Prolonged ion irradiation causes an As depletion of the surface which saturates at fluences \ensuremath{\ge}1\ifmmode\times\else\texttimes\fi{}${10}^{16}$ ${\mathrm{Ar}}^{+}$/${\mathrm{cm}}^{2}$, again dependent on the impact energy and flux density. The steady-state Ga/As surface concentration ratio (${\mathit{c}}_{\mathrm{Ga}}$/${\mathit{c}}_{\mathrm{As}}$${)}_{\mathrm{\ensuremath{\infty}}}$ is 1.25 (relative to the bulk composition) at 200 eV and increases to \ensuremath{\sim}1.45 at 3 keV. These surface composition changes are reduced for ion bombardment at elevated specimen temperatures and almost no variations are observed with the sample held at 730 K.

The infrared absorption of silicon oil with metal overlayers was studied using attenuated total reflection (ATR) technique. It is shown that the presence of thin (40...100 angstroms) Ag films leads to significant enhancement of absorption band intensities.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Optical properties of ultrathin metal (Nb) films (1.5 angstroms - 20 angstroms) on (alpha) - quartz have been studied. On quartz the metal films were prepared by radio frequency sputtering. Such films shows metallic behavior even for the thickness of a few angstroms. Then the samples were covered by a 50 angstroms Si protective film. As was found earlier, the imaginary part of dielectric function (Im(Epsilon) ) of Nb depends on the thickness nonmonotonically and has maximum at 6 angstroms. To study this effect in more detail we have used two sets of samples with thickness increasing from sample to sample on 2 angstroms and on 1.5 angstroms. All spectra were recorded using Fourier-transform spectrometer Michelson-110 (BOMEM).© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Autologous ear cartilage is relatively easy to procure in suitable form and sufficient quantity. At the donor site, there are, as a rule, no complications to be expected. Autologous ear cartilage without conjunctival coverage is of good use for replacing and lengthening the inner layer of an eyelid, not only to reconstruct large eyelid-defects, but also to give additional support and length. The cartilage graft will grow on well, provided the wound is well vascularized. This must not be expected with scarring or poor blood perfusion. The brittleness of the cartilage demands an adapted technique. Precautions to protect the cornea and to prevent adhesions in the fornix are to be taken.

Lyophilization of the amber-colored, fluorescent oils obtained via thermolysis of amino acid mixtures (Lys, Ala, Gly) leads to a cellular-structured material—with an average cell diameter of 50 μm. The cellular aggregates show a resemblance to epithel tissues. Single cellular entities find their analogs in Fox microspheres as well as in the microfossilsIsuasphaera. Short-wave UV (254 nm) irradiation of the aqueous suspensions destroys the cells, whereas suspension in saline solutions (NaCl) offers protection against dissolution by UV light. The fluorescence spectrum of the microscopic preparations containing the highly fluorescent cellular material (“lumispheres”) was registered.

The measurement of reflection and transmission of normally incident light to obtain the optical constants of a material is a usual tool in solid-state spectroscopy. If the material under investigation is a thin film, the interaction of the electromagnetic field with the sample can be enhanced by oblique incidence. If the light is p-polarized, structures in the reflection and transmission spectra are observed at the frequencies of transverse (TO) and longitudinal (LO) resonances. The LO structure — called the Berreman effect — is generated by the surface charges due to the normal component of the electric field. We discuss this effect for three cases: a free film, a film with a metallic back and a substrate with thin films on both sides. The dependence of the effect on the energy-loss function Im {−1/ɛ} and on the film thickness is discussed. For idealized systems simple formulae are derived and a characteristic parameter, called the Berreman thickness, is obtained. Films of this thickness show a maximum effect. Intuitive arguments are given to explain the effect. Examples for the application of the Berreman effect to characterize very thin films are discussed.

The 29Si chemical shifts of several trimethyl silyl derivatives of amines and amides are measured and compared to other chemical and theoretical properties such as the basicities or the electronic charge on the nitrogen or the hydrogen of the N-H group of the amine or the amide. Whereas the 29Si chemical shift of saturated amines can be rationalized in terms of substituent effects, the shifts of aromatic amines show some dependency on the basic character of the amine. There seems to be little correlation between 29Si chemical shifts and electronic charge, but there is a similarity of 29Si with 1H chemical shifts of the NH group, which is interpreted as depending on anisotropy effects.

Measurements of the reflectance and transmittance in the infrared part of the spectrum (400...4000cm−1) are carried out on oxidized Si wafers. Intrinsic dielectric properties of the oxide layers prepared by various methods are derived from experimental data. The dielectric functions of the oxides can be fitted by oscillator models. The related model parameters are compared with those of other SiO2 samples, as crystals and glasses. Optical arrangements to detect and characterize layers of thicknesses down to 3 nm are discussed. In particular, it is shown that experiments with polarized light at oblique incidence up to 80° are a powerful tool to characterize those layers. Experiments are reported to determine, in addition, extrinsic properties such as B and P atoms in the oxide layer or defects due to an ion implantation treatment. Conditions are discussed which should be applied to obtain the best quantitative analysis of the defect concentration.

Current technology permits the deposition of Al2O3 films up to a few tens of microns thick at low temperature, only after several hours. To this end, a modified technique for the production of films by dc reactive magnetron sputtering is presented focused on a combined hard and software approach using the principle of separation of the reactive gas feed from the target gas region. Results obtained from this are reported in the context of the hysteresis effect associated with such deposition processes. The applicability of this approach is extended to the deposition of other nonconducting materials. Film properties such as adhesion, optical absorption, hardness, and composition are presented and compared to those for Al2O3 produced by rf diode and rf magnetron sputtering. Deposition rate and process performance are also given for all techniques. The suitability of the material to magnetic head applications is also discussed.

Examination of the tension, speed, and power characteristics of regular and “tensionless” dye jigs shows conclusively that the tensionless type maintains more uniform low tension in the cloth with less operator attention. However, it is impracticable to maintain as high a tension as in a regular jig, in spite of the larger motor which must be used. Although the cost of power is at least twice as much as for a regular jig handling the same production the difference is usually not of commercial importance. The cloth speed is not constant. When rolling a 30-in. roll on to a 6-in. beam, the cloth speed more than doubles after the start. The present paper derives formulas which may readily be used for computing the performance of any jig and batch of cloth. Thus are disclosed ways toward improvements in both types of jigs which should overcome their respective disadvantages. Such methods of improvement are believed to be of interest both to manufacturers and to users of dye jigs.

The analytical investigation herewith reported was undertaken in order to determine whether or not the manner in which an abrasive cutoff wheel is operated might have an important effect upon the amount of service obtainable during the life of each wheel; and whether or not the maximum possible cutting rate might also be subject to improvement by better methods of operation. The geometrical relationships involved in cutting round stock have been determined, with the stock rigidly clamped and with the stock rotating in each direction relative to the wheel rotation. Based on the geometry of the several conditions, some predictions have been made as to the advantages which might be gained by a well-organized experimental program.

This paper presents analytical studies of the most common problems that are encountered in the design of mechanisms to rotate airplane propeller blades about their axes. It includes (1) a brief discussion of centrifugal thrust-bearing loads, (2) an analysis of the torque created by centrifugal force, (3) an analysis of lateral bearing loads from which their frictional torques can be determined, and (4) an investigation of the centrifugal torque of multiple masses by means of which a counterbalance can be designed to neutralize to any desired extent, at all settings, the centrifugal blade torque. The analyses are carried further than in previous published work, and results are reached by which quantitative design data can be obtained with minimum numerical and graphical labor.