[National data set "emergency department": development, structure and approval by the Deutsche Interdisziplinäre Vereinigung für Intensivmedizin und Notfallmedizin]

BACKGROUND

The Deutsche Interdisziplinäre Vereinigung für Intensivmedizin und Notfallmedizin (DIVI) is divided into sections one of which is the "Sektion Notaufnahmeprotokoll" (emergency department protocol section) founded in 2007. The main task was to create a national data set for the documentation of patients in emergency departments (ED).

MATERIAL AND METHODS

In order to create such a data set a careful look was taken at the current state of documentation in many different hospitals throughout Germany. In addition, existing registries and international requirements were also taken into consideration. The content of the dataset "ED documentation" was developed in interdisciplinary and interprofessional expert rounds.

RESULTS

The dataset "ED documentation" forms the first basis for documentation in German EDs. The modular data set contains 676 fields and covers all relevant information of the whole clinical process in the ED. Legal issues as well as several aspects for internal and external quality management are also included. For this reason the data of several German quality registries (e.g. TraumaRegister DGU® of the German Society of Trauma Surgery) are part of the data set. Furthermore, the data set forms the basis for several financial and billing aspects. A set of six forms was created in accordance with the developed modular data set. In 2010 the data set was approved by the executive committee of the DIVI. Several German medical associations (e.g. German Association for Emergency Medicine/Deutsche Gesellschaft Interdisziplinäre Notfall- und Akutmedizin, DGINA) recommend its use. Currently 80 hospitals are using the data set.

CONCLUSION

Beside the ability to exchange information the presented data set is the basis for internal and external quality assessment in the ED even if most of the available scoring and benchmarking tools are not validated for the German medical system. Implementing an ED register in Germany which is planned in the future, could close this gap.

Microscopic description of intraband absorption in graphene: the occurrence of transient negative differential transmission

We present a microscopic explanation of the controversially discussed transient negative differential transmission observed in degenerate optical pump-probe measurements in graphene. Our approach is based on the density matrix formalism allowing a time- and momentum-resolved study of carrier-light, carrier-carrier, and carrier-phonon interaction on microscopic footing. We show that phonon-assisted optical intraband transitions give rise to transient absorption in the optically excited hot carrier system counteracting pure absorption bleaching of interband transitions. While interband transition bleaching is relevant in the first hundreds of fs after the excitation, intraband absorption sets in at later times. In particular, in the low excitation regime, these intraband absorption processes prevail over the absorption bleaching resulting in a zero crossing of the differential transmission. Our findings are in good qualitative agreement with recent experimental pump-probe studies.

Anisotropy of excitation and relaxation of photogenerated charge carriers in graphene

We present a pump-probe experiment on graphene, which reveals a pronounced dependence of the pump-induced transmission on the angle between pump and probe polarization. It reflects a strong anisotropy of the pump-induced occupation of photogenerated carriers in momentum space. Within 150 fs after excitation, an isotropic carrier distribution is established. The experiments are well described by microscopic modeling, which identifies carrier-phonon scattering to be the main relaxation mechanism giving rise to an isotropic carrier distribution.

Key concepts behind forming-free resistive switching incorporated with rectifying transport properties

This work reports the effect of Ti diffusion on the bipolar resistive switching in Au/BiFeO₃/Pt/Ti capacitor-like structures. Polycrystalline BiFeO₃ thin films are deposited by pulsed laser deposition at different temperatures on Pt/Ti/SiO₂/Si substrates. From the energy filtered transmission electron microscopy and Rutherford backscattering spectrometry it is observed that Ti diffusion occurs if the deposition temperature is above 600°C. The current-voltage (I–V) curves indicate that resistive switching can only be achieved in Au/BiFeO₃/Pt/Ti capacitor-like structures where this Ti diffusion occurs. The effect of Ti diffusion is confirmed by the BiFeO₃ thin films deposited on Pt/sapphire and Pt/Ti/sapphire substrates. The resistive switching needs no electroforming process, and is incorporated with rectifying properties which is potentially useful to suppress the sneak current in a crossbar architecture. Those specific features open a promising alternative concept for nonvolatile memory devices as well as for other memristive devices like synapses in neuromorphic circuits.

Forming-free resistive switching in multiferroic BiFeO3 thin films with enhanced nanoscale shunts

A controlled shunting of polycrystalline oxide thin films on the nanometer length scale opens the door to significantly modify their transport properties. In this paper, the low energy Ar(+) irradiation induced shunting effect of forming-free, non-volatile resistive switching in polycrystalline BiFeO3 thin film capacitor-like structures with macroscopic bottom and top contacts was investigated. Oxygen atoms at the BiFeO3 surface are preferentially sputtered by Ar(+) ion irradiation and oxygen vacancies and a metallic Bi phase are formed at the surface of the BiFeO3 thin film before deposition of the top contacts. A phenomenological model is that of nanoscale shunt resistors formed in parallel to the actual BiFeO3 thin film capacitor-like structure. This model fits the noticeable increase of the retention stability and current density after irradiation. The formation of stable and conductive shunts is further evidenced by conductive atomic force microscopy measurements.

[The concept of small volume resuscitation for preclinical trauma management. Experiences in the Air Rescue Service]

BACKGROUND

Prompt hemorrhage control and adequate fluid resuscitation are the key components of early trauma care. However, the optimal resuscitation strategy remains controversial. In this context the small volume resuscitation (SVR) concept with hypertonic-hyperoncotic solutions is a new strategy.

PATIENTS AND METHODS

This was a retrospective study in the Helicopter Emergency Medical Service over a 5-year period. Included were all major trauma victims if they were candidates for SVR (initially 4 ml HyperHaes/kg body weight, followed by conventional fluid resuscitation with crystalloids and colloids). Demographic data, type and cause of injury and injury severity score (ISS) were recorded and the amount of fluid volume and the hemodynamic profile were analyzed. Negative side-effects as well as sodium chloride serum levels on hospital admission were recorded.

RESULTS

A total of 342 trauma victims (male 70.2%, mean age 39.0 ± 18.8 years, ISS 31.6 ± 16.9, ISS>16, 81.6%) underwent prehospital SVR. A blunt trauma mechanism was predominant (96.8%) and the leading cause of injury was motor vehicle accidents (61.5%) and motorcycle accidents (22.3%). Multiple trauma and polytrauma were noted in 87.4% of the cases. Predominant was traumatic brain injury (73.1%) as well as chest injury (73.1%) followed by limb injury (69.9%) and abdominal/pelvic trauma (45.0%). Within the whole study group in addition to 250 ml HyperHaes, mean volumes of 1214 ± 679 ml lactated Ringers and 1288 ± 954 ml hydroxethylstarch were infused during the prehospital treatment phase. There were no statistically significant differences in the amount of crystalloids and colloids infused regarding the subgroups multisystem trauma (ISS>16), severe traumatic brain injury (GCS<9) and entrapment trauma compared to the total study group. In patients with an initial systolic blood pressure (SBP) >80 mmHg significantly less colloids (1035 ± 659 ml vs. 1288 ± 954 ml, p<0.006) were infused, whereas in patients with an initial SBP ≤ 80 mmHg significantly more colloids were infused (1609 ± 1159 ml vs. 1288 ± 954 ml, p<0.002). There was a statistically significant increase in systolic as well as diastolic blood pressure at all times of blood pressure measurement during prehospital treatment after bolus infusion of HyperHaes within the whole study group. The same applies to the subgroups multisystem trauma, severe traumatic brain injury and entrapment trauma. Minor negative side-effects were observed in 4 cases (1.2%). The mean serum sodium chloride profile on hospital admission was 146.9 ± 5.0 mmol/l, the base excess (BE) was -5.7 ± 5.3 mmol/l) and the pH was 7.3 ± 0.1.

CONCLUSION

The concept of small volume resuscitation provides early and effective hemodynamic control. Clinical side-effects associated with bolus infusion of hypertonic-hyperoncotic solutions are rare.

Reverse epitaxy of Ge: ordered and faceted surface patterns

Normal incidence ion irradiation at elevated temperatures, when amorphization is prevented, induces novel nanoscale patterns of crystalline structures on elemental semiconductors by a reverse epitaxial growth mechanism: on Ge surfaces irradiation at temperatures above the recrystallization temperature of 250 °C leads to self-organized patterns of inverse pyramids. Checkerboard patterns with fourfold symmetry evolve on the Ge (100) surface, whereas on the Ge (111) surface, isotropic patterns with a sixfold symmetry emerge. After high-fluence irradiations, these patterns exhibit well-developed facets. A deterministic nonlinear continuum equation accounting for the effective surface currents due to an Ehrlich-Schwoebel barrier for diffusing vacancies reproduces remarkably well our experimental observations.

Transient increase of the energy gap of superconducting NbN thin films excited by resonant narrow-band terahertz pulses

Observations of radiation-enhanced superconductivity have thus far been limited to a few type-I superconductors (Al, Sn) excited at frequencies between the inelastic scattering rate and the superconducting gap frequency 2Δ/h. Utilizing intense, narrow-band, picosecond, terahertz pulses, tuned to just below and above 2Δ/h of a BCS superconductor NbN, we demonstrate that the superconducting gap can be transiently increased also in a type-II dirty-limit superconductor. The effect is particularly pronounced at higher temperatures and is attributed to radiation induced nonthermal electron distribution persisting on a 100 ps time scale.

Thermally assisted all-optical helicity dependent magnetic switching in amorphous Fe(100-x)Tb(x) alloy films

All-optical switching (AOS) in ferrimagnetic Fe(100-x)Tb(x) alloys is presented. AOS is witnessed below, above, and in samples without a magnetic compensation point. It is found that AOS is associated with laser heating up to the Curie temperature and intimately linked to a low remanent sample magnetization. Above a threshold magnetization of 220 emu/cc helicity dependent AOS is replaced by pure thermal demagnetization.

Large area photoconductive terahertz emitter for 1.55 μm excitation based on an InGaAs heterostructure

We present scalable large area terahertz (THz) emitters based on a nanoscale multilayer InGaAs/InAlAs heterostructure and a microstructured electrode pattern. The emitters are designed for pump lasers working at the telecommunication wavelength of 1.55 μm. Electric THz fields of more than 2.5 V cm⁻¹ are reached with moderate pump powers of 80 mW, the corresponding spectrum extends up to 3 THz. The saturation characteristics have been investigated for different pump laser spot sizes. For small pump powers of less than 50 mW the emitted THz field is nearly independent of the spot size, for higher pump powers and small spot sizes a clear saturation of the generated THz pulse can be observed. Hence the use of scalable emitters is especially promising for high power fibre laser systems. The spectral content of the generated radiation is nearly independent of the parameters spot size, pump power, and bias voltage, which allows for stable operation in spectroscopic applications.

Observation of forbidden exciton transitions mediated by Coulomb interactions in photoexcited semiconductor quantum wells

We use terahertz pulses to induce resonant transitions between the eigenstates of optically generated exciton populations in a high-quality semiconductor quantum well sample. Monitoring the excitonic photoluminescence, we observe transient quenching of the 1s exciton emission, which we attribute to the terahertz-induced 1s-to-2p excitation. Simultaneously, a pronounced enhancement of the 2s exciton emission is observed, despite the 1s-to-2s transition being dipole forbidden. A microscopic many-body theory explains the experimental observations as a Coulomb-scattering mixing of the 2s and 2p states, yielding an effective terahertz transition between the 1s and 2s populations.

Time-resolved spectroscopy on epitaxial graphene in the infrared spectral range: relaxation dynamics and saturation behavior

We present the results of pump–probe experiments on multilayer graphene samples performed in a wide spectral range, namely from the near infrared (photon energy 1.5 eV) to the terahertz (photon energy 8 meV) spectral range. In the near infrared, exciting carriers and probing at higher photon energies provides direct evidence for a hot carrier distribution. Furthermore, spectroscopic signatures of the highly doped graphene layers at the interface to SiC are observed in the near-infrared range. In the mid-infrared range, the various relaxation mechanisms, in particular scattering via optical phonons and Auger-type processes, are identified by comparing the experimental results to microscopic modeling. Changes from induced transmission to induced absorption are attributed to probing above or below the Fermi edge of the graphene layers. This effect occurs for certain photon energies in the near-infrared range, where it is related to highly doped graphene layers at the interface to SiC, and in the far-infrared range for the quasi-intrinsic graphene layers. In addition to the relaxation dynamics, the saturation of pump-induced bleaching of graphene is studied. Here a quadratic dependence of the saturation fluence on the pump photon energy in the infrared spectral range is revealed.

InP nanocrystals on silicon for optoelectronic applications

One of the solutions enabling performance progress, which can overcome the downsizing limit in silicon technology, is the integration of different functional optoelectronic devices within a single chip. Silicon with its indirect band gap has poor optical properties, which is its main drawback. Therefore, a different material has to be used for the on-chip optical interconnections, e.g. a direct band gap III-V compound semiconductor material. In the paper we present the synthesis of single crystalline InP nanodots (NDs) on silicon using combined ion implantation and millisecond flash lamp annealing techniques. The optical and microstructural investigations reveal the growth of high-quality (100)-oriented InP nanocrystals. The current-voltage measurements confirm the formation of an n-p heterojunction between the InP NDs and silicon. The main advantage of our method is its integration with large-scale silicon technology, which allows applying it for Si-based optoelectronic devices.

Magnetic Mn5Ge3 nanocrystals embedded in crystalline Ge: a magnet/semiconductor hybrid synthesized by ion implantation

The integration of ferromagnetic Mn5Ge3 with the Ge matrix is promising for spin injection in a silicon-compatible geometry. In this paper, we report the preparation of magnetic Mn5Ge3 nanocrystals embedded inside the Ge matrix by Mn ion implantation at elevated temperature. By X-ray diffraction and transmission electron microscopy, we observe crystalline Mn5Ge3 with variable size depending on the Mn ion fluence. The electronic structure of Mn in Mn5Ge3 nanocrystals is a 3d6 configuration, which is the same as that in bulk Mn5Ge3. A large positive magnetoresistance has been observed at low temperatures. It can be explained by the conductivity inhomogeneity in the magnetic/semiconductor hybrid system.

[The TraumaRegister DGU® as the basis of medical quality management. Ten years experience of a national trauma centre exemplified by emergency room treatment]

BACKGROUND

The trauma register of the German Society of Trauma Surgery (TraumaRegister DGU®/TR-DGU) has been proven to be a valuable tool for external assessment of quality in the treatment of patients with major trauma. This publication shows for the first time how the quality of trauma treatment in a level I trauma centre could be improved over a period of almost ten years with the help of continuous quality management, i.e. recognizing a problem, developing a solution and evaluating its effect.

MATERIALS AND METHODS

Tracer parameters and indicators of quality are presented in four periods over a total study period from 1st January 1989 to 31st March 2007. The division into four periods is due to major changes in the trauma treatment algorithms or structural changes in the trauma room. The results are displayed for all patients treated in the trauma room and for those patients with an injury severity score (ISS)≥16.

RESULTS

Over all four periods a total number of n=2,239 patients were admitted to the trauma room. Based on the results of the trauma register a number of changes were made, not only structural changes, such as the introduction of point-of-care diagnostics, initially conventional X-ray, then digital X-ray and finally multislice computed tomography (CT) scanning in the trauma room but also changes in the way personnel participating in the trauma treatment are trained. Advanced trauma life support (ATLS®) has become the standard training for doctors and prehospital trauma life support (PHTLS®) for nurses. Time efficient treatment algorithms were introduced. All measures led to changes in several parameters which are chosen as indicators for good treatment quality. It was for instance possible to reduce the average total trauma treatment time for patients with an ISS≥16 from initially 90.9±48.6 min to 37.4±18.  min in the final study period.

CONCLUSIONS

The external quality management performed by the TR-DGU has proved to be a constant source of inspiration. The effects of the changes made can be scientifically proven. It is to be discussed to what extent a sole external quality management can be useful.

Intersublevel spectroscopy on single InAs-quantum dots by terahertz near-field microscopy

Using scattering-type near-field infrared microscopy in combination with a free-electron laser, intersublevel transitions in buried single InAs quantum dots are investigated. The experiments are performed at room temperature on doped self-assembled quantum dots capped with a 70 nm GaAs layer. Clear near-field contrast of single dots is observed when the photon energy of the incident beam matches intersublevel transition energies, namely the p-d and s-d transition of conduction band electrons confined in the dots. The observed room-temperature line width of 5-8 meV of these resonances in the mid-infrared range is significantly below the inhomogeneously broadened spectral lines of quantum dot ensembles. The experiment highlights the strength of near-field microspectroscopy by demonstrating signals from bound-to-bound transitions of single electrons in a probe volume of the order of (100 nm)(3).

[Special aspects of the emergency medical care of head and neck injuries]

The overall incidence of severe head, face and neck injuries as seen from the German Trauma Registry of the National Association of German Trauma Surgeons is 81.3%. The leading causes of death among these patients are hemorrhage and severe traumatic brain injury. The aim of prehospital emergency medical care is to stabilize vital functions in order to ensure primary survival and to reduce morbidity with appropriate prehospital treatment of the individual injuries within the overall injury pattern. In this review, special aspects as well as pitfalls of the prehospital management of patients with head, face and neck injuries are demonstrated. Prehospital airway management concepts as well as concepts for stopping bleeding in the head, face and neck region are discussed in detail.