Shape-controlling effects of hydrohalic and carboxylic acids in TiO2 nanoparticle synthesis.

The ability to synthesize nanoparticles (NPs), here TiO2, of different shapes in a controlled and reproducible way is of high significance for a wide range of fields including catalysis and materials design. Different NP shapes exhibit variations of emerging facets, and processes such as adsorption, diffusion, and catalytic activity are, in general, facet sensitive. Therefore, NP properties, e.g., the reactivity of NPs or the stability of assembled NPs, depend on their shape. We combine computational modeling based on density functional theory with experimental techniques such as transmission electron microscopy, energy-dispersive x-ray spectroscopy, and x-ray powder diffraction to investigate the ability of various adsorbates, including hydrohalic and carboxylic acids, to influence NP shape. This approach allows us to identify mechanisms stabilizing specific surface facets and thus to predict NP shapes using computational model systems and to experimentally characterize the synthesized NPs in detail. Shape-controlled anatase TiO2 NPs are synthesized here in agreement with the calculations in platelet and bi-pyramidal shapes by employing different precursors. The importance of the physical conditions and chemical environment during synthesis, e.g., via competitive adsorption or changes in the chemical potentials, is studied via ab initio thermodynamics, which allows us to set previous and new results in a broader context and to highlight potentials for additional synthesis routes and NP shapes.

Limited influence of blunt aortic injuries on the outcome of polytraumatized patients: a matched pair analysis.

INTRODUCTION: Traumatic lesions of great vessels such as the aorta are life-threatening injuries. There is limited evidence about the influence of traumatic aortic injuries in multiple trauma patients in particular with regard to posttraumatic complications. The aim of this study was to evaluate the influence of blunt thoracic aortic injuries in multiple trauma patients compared to a multiple trauma cohort without this specific injury. In addition, the safety of Thoracic Endovascular Aortic Repair (TEVAR) in multiple trauma patients was analyzed. MATERIALS AND METHODS: A retrospective study was performed. We included all multiple trauma patients (ISS ≥ 16, age > 14 years) between 2005 and 2014 with (group BTAI) and without (group nBTAI) blunt traumatic aortic injuries who were treated at our level-1 trauma center. Demographic as well as clinical parameters were analyzed including injury pattern, mechanism of injury, posttraumatic complications such as ARDS, multiple organ dysfunction syndrome (MODS) and others. A matched pair analysis was performed by propensity score matching. RESULTS: In total, 721 patients were enrolled (group BTAI: n = 45; nBTAI: n = 676). In the initial study population, surgical intervention was done in n = 32 (71.1%) patients (TEVAR: n = 25; 78.1%), there was an increased AISChest and overall injury severity in group BTAI with associated significantly more posttraumatic complications in group BTAI. The matched pair analysis consisted of 42 patients per group. Beside an increased ventilation time, no significant differences were evident after the matching process. There was a trend to increased risk for SIRS using binary logistic regression analysis. CONCLUSIONS: Multiple trauma patients with blunt thoracic aortic injuries who are treated at a level-1 trauma center show a comparable outcome matched to their counterparts without aortic injuries. Our study confirms that using TEVAR in polytraumatized patients is a safe procedure. In all patients treated with TEVAR, there were no procedure-related complications, especially no neurological deficit.

[Injury to the upper limbs and prevention in equestrian sports]. / Verletzungen der oberen Extremität und Prävention im Reitsport.

The upper limb is one of the most frequently injured body regions in equestrian sports, but it is unclear which injuries are involved, and there are no data on the associated accident mechanism. The present study is aimed at evaluating the accident mechanisms, injuries of the upper limbs, and the circumstances of the accident in equestrian sports. We included 218 patients who were all treated between 2006 and 2014 at the level I trauma center at the Medical University in Hannover because of equestrian-related accidents. The most frequent injuries were fractures and bruising in the shoulder area, fingers and hands, and the distal area of the lower arm, which were mostly caused by the horse kicking. To prevent hand injuries it is recommended that gloves are worn; the potential introduction of strengthened materials could protect the bones from severe bumping. Training in falling techniques to prevent serious injury to the upper limb would be useful. In general, primary prevention in equestrian sports should be extended to counteract the increasing neglect of protective equipment.

[Accidents in equestrian sports : Analysis of injury mechanisms and patterns]. / Unfälle im Reitsport : Analyse von Verletzungsmechanismen und -mustern.

BACKGROUND: Equestrian sports are one of the most popular forms of sport in Germany, while also being one of the most accident-prone sports. Furthermore, riding accidents are frequently associated with a high degree of severity of injuries and mortality. Nevertheless, there are insufficient data regarding incidences, demographics, mechanisms of accidents, injury severity and patterns and outcome of injured persons in amateur equestrian sports. Accordingly, it was the aim of the present study to retrospectively analyze these aspects. METHODS: A total of 503 patients were treated in the emergency room of the Hannover Medical School because of an accident during recreational horse riding between 2006 and 2011. The female gender was predominantly affected with 89.5 %. The mean age of the patients was 26.2 ± 14.9 years and women (24.5 ± 12.5 years) were on average younger than men (40.2 ± 23.9 years). A special risk group was girls and young women aged between 10 and 39 years. The overall injury severity was measured using the injury severity score (ISS). RESULTS: Based on the total population, head injuries were the most common location of injuries with 17.3 % followed by injuries to the upper extremities with 15.2 % and the thoracic and lumbar spine with 10.9 %. The three most common injury locations after falling from a horse were the head (17.5 %), the upper extremities (17.4 %), the thoracic and lumbar spine (12.9 %). The most frequent injuries while handling horses were foot injuries (17.2 %), followed by head (16.6 %) and mid-facial injuries (15.0 %). With respect to the mechanism of injury accidents while riding were predominant (74 %), while accidents when handling horses accounted for only 26 %. The median ISS was 9.8 points. The proportion of multiple trauma patients (ISS > 16) was 18.1 %. Based on the total sample, the average in-hospital patient stay was 5.3 ± 5.4 days with a significantly higher proportion of hospitalized patients in the group of riding accidents. Fatal cases were not found in this study but the danger of riding is not to be underestimated. The large number of sometimes severe injuries with ISS values up to 62 points can be interpreted as an indication that recreational riding can easily result in life-threatening situations. CONCLUSION: Girls and young women could be identified as a group at particular risk. It has been demonstrated in this study that the three most common injury locations after falling from a horse were the head, the upper extremities, the thoracic and lumbar spine. The most frequent injury locations while handling horses were foot injuries, followed by head and mid-facial injuries.

[Cervical spine injury in equestrian sports]. / Halswirbelsäulenverletzungen im Breitenreitsport.

The cervical spine is considered fragile and vulnerable to injuries in equestrian sport. This retrospective study investigates the injury pattern and severity. Patients of the medical university in Hannover from the years 2006-2011, who had an equestrian accident, were identified. Patients who had been injured in the course of their work were excluded. Results counted with a p-value < 0.05 were considered significant. In 13.1% of patients, there were 71 cervical spine injuries (92.4% female; 7.6% male). The mean age was 27.1 ± 13.2 years. Of these, 86.4% associated the injury to the riding accident. In 56 cases, it concerned falls from the horse. In 13.6% of the cases, the injury was caused while handling the horse. Sprains were most common (70.4%). Fractures of the neck vertebrae were found in 22.5% of the cases. The mean ISS was 7.0 ± 5.8 pts. Polytrauma was identified in 6.1% of patients (ISS ≥ 16 Pkt). The most common accompanying injury presented was an injury to the head (29.2%; p = 0.003). Of the 30 hospitalized patients, 13.3% were admitted to intensive medical care for 2.3 ± 15.4 d. The mortality was 0%. Injuries of the cervical spine are not to be underestimated in their frequency and severity. It is shown that, especially with injuries of the head and thoracic and lumbar spine area, patients are at increased risk of concurrent cervical lesions. The prevention of neck injuries is currently done in the form of riding helmets, airbag jackets, riding behavior and education. Further study of the prevention of neck injuries is required.

Electron rearrangement dynamics in dissociating I(2)

The charge rearrangement in dissociating I_{2}^{n+} molecules is measured as a function of the internuclear distance R using extreme ultraviolet pulses delivered by the free-electron laser in Hamburg. Within an extreme ultraviolet pump-probe scheme, the first pulse initiates dissociation by multiply ionizing I_{2}, and the delayed probe pulse further ionizes one of the two fragments at a given time, thus triggering charge rearrangement at a well-defined R. The electron transfer between the fragments is monitored by analyzing the delay-dependent ion kinetic energies and charge states. The experimental results are in very good agreement with predictions of the classical over-the-barrier model demonstrating its validity in a thus far unexplored quasimolecular regime relevant for free-electron laser, plasma, and chemistry applications.

[Challenges in the context of medical care during a naval research expedition. A case report]. / Herausforderungen im Rahmen der ärztlichen Begleitung einer Forschungsseereise. Ein Erfahrungsbericht.

Exploration for natural resources in the seabed of the Indian Ocean was undertaken by the German government institution of earth sciences and resources ("Bundesanstalt für Geowissenschaften und Rohstoffe", BGR) in November 2012. To provide for the medical safety of crew and scientists, a cooperation between the BGR and the trauma department of the Hannover Medical School was established. Research by physicians accompanying the naval expedition revealed that medical consultations mainly occur because of respiratory infections, abdominal discomfort, genitourinary discomfort and seasickness, with the rate of traumas being between 31% and 41%. Di Giovanna et al. stated that 97% of all emergencies on cruise ships are not critical and only 3% need an immediate emergency medical intervention. Consultations were already performed on the mainland prior to departure and included minor traumas due to non-appropriate footwear, otitis and respiratory infections. Seasickness was the main reason for consultation during the first days at sea. Strong seas resulted in some bruises. Minor injuries and foreign body injuries to the hands and feet also required consultation. First-degree sunburns resulted from exposure to the sun, while air-conditioning caused rhinosinusitis and conjunctivitis. A special consultation was a buccal splitting of tooth 36. An immediate emergency medical intervention was not necessary due to the relative low level of pain for the patient; however, due to the risk of further damage caused by nocturnal bruxism, a protective splint was formed using a small syringe. Other reasons for consultation were similar to those reported in the general literature. Medical activities at exotic locations may create the vision of a holiday character at first; however, intensive planning and preparation are needed. We recommend contacting police, customs, the federal institute for drugs and medical devices as well as the labour inspectorate, preferably in both the originating country and the destination, to prepare custom formalities and to obtain formal documents and approvals beforehand. It is advisable to be prepared not only for emergency situations, but also for general medical and dental problems. Improvisation in the treatment of special health problems is an unavoidable requisite.

Ultrafast charge rearrangement and nuclear dynamics upon inner-shell multiple ionization of small polyatomic molecules.

Ionization and fragmentation of methylselenol (CH(3)SeH) molecules by intense (>10(17) W/cm(2)) 5 fs x-ray pulses (hω=2 keV) are studied by coincident ion momentum spectroscopy. We contrast the measured charge state distribution with data on atomic Kr, determine kinetic energies of resulting ionic fragments, and compare them to the outcome of a Coulomb explosion model. We find signatures of ultrafast charge redistribution from the inner-shell ionized Se atom to its molecular partners, and observe significant displacement of the atomic constituents in the course of multiple ionization.

Time-resolved measurement of interatomic coulombic decay in Ne2.

The lifetime of interatomic Coulombic decay (ICD) [L. S. Cederbaum et al., Phys. Rev. Lett. 79, 4778 (1997)] in Ne2 is determined via an extreme ultraviolet pump-probe experiment at the Free-Electron Laser in Hamburg. The pump pulse creates a 2s inner-shell vacancy in one of the two Ne atoms, whereupon the ionized dimer undergoes ICD resulting in a repulsive Ne+(2p(-1))-Ne+(2p(-1)) state, which is probed with a second pulse, removing a further electron. The yield of coincident Ne+-Ne2+ pairs is recorded as a function of the pump-probe delay, allowing us to deduce the ICD lifetime of the Ne2(+)(2s(-1)) state to be (150±50) fs, in agreement with quantum calculations.

Ultrastable, high-repetition-rate attosecond beamline for time-resolved XUV-IR coincidence spectroscopy.

The implementation of attosecond photoelectron-photoion coincidence spectroscopy for the investigation of atomic and molecular dynamics calls for a high-repetition-rate driving source combined with experimental setups characterized by excellent stability for data acquisition over time intervals ranging from a few hours up to a few days. This requirement is crucial for the investigation of processes characterized by low cross sections and for the characterization of fully differential photoelectron(s) and photoion(s) angular and energy distributions. We demonstrate that the implementation of industrial-grade lasers, combined with a careful design of the delay line implemented in the pump-probe setup, allows one to reach ultrastable experimental conditions leading to an error in the estimation of the time delays of only 12 as over an acquisition time of 6.5 h. This result opens up new possibilities for the investigation of attosecond dynamics in simple quantum systems.

Nanoplasma dynamics of single large xenon clusters irradiated with superintense x-ray pulses from the linac coherent light source free-electron laser.

The plasma dynamics of single mesoscopic Xe particles irradiated with intense femtosecond x-ray pulses exceeding 10(16) W/cm2 from the Linac Coherent Light Source free-electron laser are investigated. Simultaneous recording of diffraction patterns and ion spectra allows eliminating the influence of the laser focal volume intensity and particle size distribution. The data show that for clusters illuminated with intense x-ray pulses, highly charged ionization fragments in a narrow distribution are created and that the nanoplasma recombination is efficiently suppressed.

Wavelength dependence of the suppressed ionization of molecules in strong laser fields.

We study ionization of molecules by an intense laser field over a broad wavelength regime, ranging from 0.8 to 1.5 µm experimentally and from 0.6 to 10 µm theoretically. A reaction microscope is combined with an optical parametric amplifier to achieve ionization yields in the near-infrared wavelength regime. Calculations are done using the strong-field S-matrix theory and agreement is found between experiment and theory, showing that ionization of many molecules is suppressed compared to the ionization of atoms with identical ionization potentials at near-infrared wavelengths at around 0.8 µm, but not at longest wavelengths (10 µm). This is due to interference effects in the electron emission that are effective at low photoelectron energies but tend to average out at higher energies. We observe the transition between suppression and nonsuppression of molecular ionization in the near-infrared wavelength regime (1-5 µm).

Attosecond photoionisation time delays reveal the anisotropy of the molecular potential in the recoil frame.

Photoionisation time delays carry structural and dynamical information on the target system, including electronic correlation effects in atoms and molecules and electron transport properties at interfaces. In molecules, the electrostatic potential experienced by an outgoing electron depends on the emission direction, which should thus lead to anisotropic time delays. To isolate this effect, information on the orientation of the molecule at the photoionisation instant is required. Here we show how attosecond time delays reflect the anisotropic molecular potential landscape in CF4 molecules. The variations in the measured delays can be directly related to the different heights of the potential barriers that the outgoing electrons see in the vicinity of shape resonances. Our results indicate the possibility to investigate the spatial characteristics of the molecular potential by mapping attosecond photoionisation time delays in the recoil-frame.

A single dose of intravenous zoledronate prevents glucocorticoid therapy-associated bone loss in acute flare of Crohn's disease, a randomized controlled trial.

OBJECTIVES: To assess the effectiveness and safety of zoledronate (ZOL) in preventing glucocorticoid therapy-associated bone loss in patients with acute flare of Crohn's disease (CD) in a randomized, double-blind, placebo-controlled trial. METHODS: Forty CD patients starting a glucocorticoid therapy (60 mg prednisolone per day) for acute flare (CD activity index (CDAI) >220) were randomized to compare the effect of ZOL (4 mg intravenous, n=20) or placebo (n=20) on change in lumbar bone mineral density (BMD). All patients received calcium citrate (800 mg) and colecalciferol (1,000 IU) daily. Dual energy X-ray absorptiometry (DXA) of the lumbar spine (L1-L4) was performed at baseline and day 90. Follow-up examinations at day 1/7/14/30 and 90 included laboratory tests and adverse event/serious adverse events reports. RESULTS: Thirty-six patients were available for per-protocol analysis. With placebo (n=18), a decrease in BMD was seen (T-score: -0.98 ± 0.8, day 0 and -1.25 ± 0.77, day 90, P=0.06), with ZOL (n=18) BMD increased (-1.15 ± 1.02, day 0 and -0.74 ± 1.09, day 90, P=0.03). The change in BMD under placebo (-0.26 ± 0.21) vs. ZOL (+0.41 ± 0.19) was highly significant (P=0.006). In all, 14 out of 18 patients with ZOL had an increase in BMD (+0.64 ± 0.48), 12 of 18 with placebo a decrease (-0.50 ± 0.39). Changes of clinical findings and laboratory results of inflammation (leukocytes, platelets, and C-reactive protein) were the same in- and between-groups throughout the study. With ZOL, serum bone degradation marker ß-Cross-Laps decreased. Study medication was safe and well tolerated. CONCLUSIONS: ZOL is effective in preventing glucocorticoid therapy-induced bone loss in patients with acute flare of CD and should be considered whenever a glucocorticoid therapy is started in CD patients.

Second-order autocorrelation of XUV FEL pulses via time resolved two-photon single ionization of He.

Second-order autocorrelation spectra of XUV free-electron laser pulses from the Spring-8 Compact SASE Source (SCSS) have been recorded by time and momentum resolved detection of two-photon single ionization of He at 20.45 eV using a split-mirror delay-stage in combination with high-resolution recoil-ion momentum spectroscopy (COLTRIMS). From the autocorrelation trace we extract a coherence time of 8 ± 2 fs and a mean pulse duration of 28 ± 5 fs, much shorter than estimations based on electron bunch-length measurements. Simulations within the partial coherence model [Opt. Lett. 35, 3441 (2010)] are in agreement with experiment if a pulse-front tilt across the FEL beam diameter is taken into account that leads to a temporal shift of about 6 fs between both pulse replicas.

[Development of an emergency room algorithm for treatment of multiple trauma. Wolfsburg model]. / Entwicklung eines Schockraumalgorithmus für die Polytraumaversorgung. "Wolfsburger Modell."

Within the framework of restructuring for the certification to a regional trauma centre of the DGU (German Society for Casualty Surgery), a uniform algorithm for multiple trauma was developed in the medical centre of Wolfsburg. The Wolfsburg multiple trauma algorithm is based on ATLS (advanced trauma life support) with integration of FAST (focused assessment with sonography for trauma), as well as the white paper of the DGU and regional-specific features. Thus structural, instrumental, organizational and personnel conditions were created to improve the care of multiply traumatized patients even further. The conditions for transition to a regional trauma centre of the DGU were confirmed by a successful audit.

Ultrafast extreme ultraviolet induced isomerization of acetylene cations.

Ultrafast isomerization of acetylene cations ([HC=CH](+)) in the low-lying excited A(2)Σ(g)(+) state, populated by the absorption of extreme ultraviolet (XUV) photons (38 eV), has been observed at the Free Electron Laser in Hamburg, (FLASH). Recording coincident fragments C(+) + CH2(+) as a function of time between XUV-pump and -probe pulses, generated by a split-mirror device, we find an isomerization time of 52±15 fs in a kinetic energy release (KER) window of 5.8

Injury severity in polytrauma patients is underestimated using the injury severity score: a single-center correlation study in air rescue.

PURPOSE: Prehospital estimation of injury severity is essential for prehospital therapy, deciding on the destination hospital and the associated emergency room care. The aim of this study was to compare prehospital estimates of the abbreviated injury scale (AIS) and the Injury Severity Score (ISS) by emergency physicians with the values of AIS and ISS of injury severity determined at the conclusion of diagnostics. METHODS: In this prospective study, the ISS was determined prehospital by emergency physicians. The validated AIS and ISS were analyzed based on final diagnoses. A Bland-Altman plot was used in analyzing the agreement between two different assays as well as sensitivity and specificity were determined. Confidence intervals were calculated for a Wilson score. Significance level was set at p ≤ 0.05. RESULTS: The prehospital ISS was estimated at 26.0 ± 13.0 and was 34.7 ± 16.3 (p < 0.001) after in-hospital validation. In addition, most of the AIS subgroups were significantly higher in the final calculation than preclinically estimated (p < 0.05). When analyzing subgroups of trauma patients (ISS < 16 vs. ISS ≥ 16), we were able to demonstrate a sensitivity of > 90% to identify a multiple-trauma patient. Diagnosing a higher injury severity group (ISS ≥ 25), sensitivity dropped to 61.1%. The Bland-Altman plot demonstrates that injury severity is underestimated in higher injury levels. CONCLUSION: Multiple-trauma patients can be identified using the ISS. Anatomic scores might be used for transport decisions; however, an accurate estimation of the injury severity should also be based on other criteria such as patient status, mechanism of injury, and other triage criteria.

Dose-response studies on the effects of alpha-, beta-, and gamma-hexachlorocyclohexane on putative preneoplastic foci, monooxygenases, and growth in rat liver.

Alpha-, beta-, and gamma-hexachlorocyclohexane (alpha-, beta-, gamma-HCH) isomers are widespread environmental pollutants; alpha-HCH can cause liver tumors in rats and mice. In the present study we have checked first the tumor-initiating activity of HCH using the appearance of phenotypically altered foci in female rat liver as an end point. Foci were identified by means of the gamma-glutamyltransferase (GGT) reaction and by morphological alterations. No evidence of initiating activity was found. Secondly, we have attempted to determine quantitatively the ability of HCH isomers to promote tumor development. For this purpose growth and phenotypic changes of foci were used as an end point. Rats received a single dose of N-nitrosomorpholine. Then five different doses of each HCH isomer or phenobarbital (PB) (as a positive control) were administered continuously via the diet for 4, 15, and 20 weeks. Both number and size of altered foci were enhanced by doses of 2 to 3 mg/kg or more of the three isomers; in addition, foci phenotypes showed a pronounced shift towards strong expression of GGT and sharp demarcation from the surrounding liver. Based on daily doses the three HCH isomers were approximately equipotent; based on concentrations in liver or adipose tissue, gamma-HCH was severalfold more effective than alpha- and beta-HCH. Thirdly, size and DNA and monooxygenase activities of the liver were determined. All three parameters were enhanced by HCH isomers and PB. However, no strict correlations were found. Rather, at the highest doses tested PB was the most effective inducer of monooxygenases, alpha-HCH was the most potent inducer of liver growth, and all three HCHs were more potent than PB as inducers of focal expansion. Thus, induction of liver growth appears to be associated with foci expansion (tumor promotion); however, neither liver growth nor monooxygenase induction can be used for quantitative predictions of foci expansion by chemical compounds. Finally, no-observed-effect levels were estimated for the parameters studied and are discussed in relation to human exposure.

Is there a benefit for health care workers in testing HIV, HCV and HBV in routine before elective arthroplasty?

INTRODUCTION: Occupational infection of clinical health care workers with blood-borne viruses (BBVs) like human immunodeficiency virus (HIV), hepatitis B virus (HBV) or hepatitis C virus (HCV) is a current and often emotionally discussed issue. HCV and especially HIV are still stigmatized. The consequence is a broad and maybe irrational fear of professional health care workers being infected occupationally. Therefore, we assessed preoperative screening to: (1) answer whether this can detect not previously diagnosed blood-borne virus infections to a great extent, (2) calculate a cost-benefit ratio to find out, if the screening's potential ability to prevent occupational transmission of BBVs to health care workers faces unjustifiable high costs. HYPOTHESIS: Preoperative routine screening is limited suitable for enhancement of detecting fomites compared to interview the patient. MATERIALS AND METHODS: Retrospective cohort study of preoperative screening for HIV, HBV and HCV (HBsAg, anti-HCV and HIV-Ab/Ag-Combination) for every patient who was admitted to the traumatologic department for elective arthroplasty between 01/01/1997 and 31/12/2008. RESULTS: Among the 1534 patients who underwent elective prosthetic surgery [total hip (879) and knee arthroplasty (508), followed by shoulder, elbow and upper ankle joint], 693 (45.2%) patients were male and 841 (54.8) female. Mean age was 64.2±13.8 years. Screening tests were available for 1373 patients (89.5%). Among all screened patients, we found 21 HCV, 10 HBV and 1 HIV infections. 5 HBV (0.5%) and 7 HCV infections (0.7%) were unknown before. Every newly detected infectious patient occasions screening costs about 7250€. Considering this data, the risk of HCV transmission from an index patient with unknown status of infectiousness to health care worker after percutaneous contact to blood is 0.08 ‰ and of HIV transmission is 0.00054 ‰ in our study population. DISCUSSION: Routine preoperative screening for BBVs of patients undergoing elective arthroplasty, who were asked for HBV, HCV and HIV, should be reconsidered and is, in times of sparse funds, overpriced. LEVEL OF EVIDENCE: IV.