Experimental capabilities for liquid jet samples at sub-MHz rates at the FXE Instrument at European XFEL.

The Femtosecond X-ray Experiments (FXE) instrument at the European X-ray Free-Electron Laser (EuXFEL) provides an optimized platform for investigations of ultrafast physical, chemical and biological processes. It operates in the energy range 4.7-20 keV accommodating flexible and versatile environments for a wide range of samples using diverse ultrafast X-ray spectroscopic, scattering and diffraction techniques. FXE is particularly suitable for experiments taking advantage of the sub-MHz repetition rates provided by the EuXFEL. In this paper a dedicated setup for studies on ultrafast biological and chemical dynamics in solution phase at sub-MHz rates at FXE is presented. Particular emphasis on the different liquid jet sample delivery options and their performance is given. Our portfolio of high-speed jets compatible with sub-MHz experiments includes cylindrical jets, gas dynamic virtual nozzles and flat jets. The capability to perform multi-color X-ray emission spectroscopy (XES) experiments is illustrated by a set of measurements using the dispersive X-ray spectrometer in von Hamos geometry. Static XES data collected using a multi-crystal scanning Johann-type spectrometer are also presented. A few examples of experimental results on ultrafast time-resolved X-ray emission spectroscopy and wide-angle X-ray scattering at sub-MHz pulse repetition rates are given.

Geometric control of next-nearest-neighbor coupling in evanescently coupled dielectric waveguides.

We experimentally demonstrate that the next-nearest-neighbor-coupling (NNN-coupling) in an array of waveguides can naturally be negative. To do so, dielectric zig-zag shaped waveguide arrays are fabricated with direct laser writing (DLW). By changing the angle of the zig-zag shape it is possible to tune between positive and negative ratios of nearest and next-nearest-neighbor coupling, which also allows to reduce the impact of the NNN-coupling to zero at the correct respective angle. We confirm the existence of negative NNN-couplings experimentally and show the improved accuracy of a refined tight-binding model. Our results are also of importance for other discrete systems in which the tight-binding model is often used.

Association between changes in knee load and effusion-synovitis: evidence of mechano-inflammation in knee osteoarthritis using high tibial osteotomy as a model.

OBJECTIVE: Although mechanically-induced inflammation is an appealing explanation linking different etiologic factors in osteoarthritis (OA), clinical research investigating changes in both biomechanics and joint inflammation is limited. The purpose of this study was to evaluate the association between change in surrogate measures of knee load and knee effusion-synovitis in patients with medial compartment knee OA undergoing high tibial osteotomy (HTO). METHODS: Thirty-six patients with medial compartment knee OA and varus alignment underwent 3D gait analysis and 3T magnetic resonance imaging (MRI) preoperatively and 1 year after medial opening wedge HTO. Primary outcome measures were the change in the external knee adduction moment impulse during walking and change in knee suprapatellar effusion-synovitis volume manually segmented on MRI by one blinded assessor. RESULTS: Mean (SD) knee adduction moment impulse [24.0 (6.5) Nm•s] and knee effusion-synovitis volume [8976.7 (8016.9) mm3] suggested substantial preoperative medial knee load and inflammation. 1-year postoperative changes in knee adduction moment impulse [-10.1 Nm•s (95%CI: -12.7, -7.4)], and knee effusion-synovitis volume [-1856 mm3 (95%CI: -3830, 117)] were positively correlated [r = 0.60 (95% CI 0.34, 0.78)]. Simple linear regression suggested a 448 mm3 (95%CI: 241, 656) reduction in knee effusion-synovitis volume per 1 Nm•s reduction in knee adduction moment impulse. Change in knee adduction moment impulse explained 36% (R2 = 0.36) of the variance of change in knee effusion-synovitis volume. CONCLUSIONS: Reduction in medial knee load is positively associated with reduction in knee inflammation after HTO, suggesting the phenomenon of mechano-inflammation in patients with knee OA.

Supportive care in the acute phase of Stevens-Johnson syndrome and toxic epidermal necrolysis: an international, multidisciplinary Delphi-based consensus.

BACKGROUND: Supportive care is the cornerstone of management of adult and paediatric Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). However, consensus on the modalities of supportive care is lacking. OBJECTIVES: Our aim in this international multicentric Delphi exercise was to establish a multidisciplinary expert consensus to standardize recommendations regarding supportive care in the acute phase of SJS/TEN. METHODS: Participants were sent a survey via the online tool SurveyMonkey, consisting of 103 statements organized into 11 topics: multidisciplinary team composition, suspect drug management, infection prevention, fluid resuscitation and prevention of hypothermia, nutritional support, pain and psychological distress management, management of acute respiratory failure, local skincare, ophthalmological management, management of other mucosa, and additional measures. Participants evaluated the level of appropriateness of each statement on a scale of 1 (extremely inappropriate) to 9 (extremely appropriate). The results were analysed according to the RAND/UCLA Appropriateness Method. RESULTS: Forty-five participants from 13 countries (on three continents) participated. After the first round, a consensus was obtained for 82.5% of the 103 initially proposed statements. After the second round, a final consensus was obtained for 102 statements. CONCLUSIONS: We have reached an international Delphi-based consensus on best supportive care practice for SJS/TEN. Our expert consensus should help guide physicians in treating patients with SJS/TEN and thereby improve short-term prognosis and the risk of sequelae.

A versatile liquid-jet setup for the European XFEL.

The SPB/SFX instrument of the European XFEL provides unique possibilities for high-throughput serial femtosecond crystallography. This publication presents the liquid-jet sample delivery setup of this instrument. The setup is compatible with state-of-the-art gas dynamic virtual nozzle systems as well as high-viscosity extruders and provides space and flexibility for other liquid injection devices and future upgrades. The liquid jets are confined in a differentially pumped catcher assembly and can be replaced within a couple of minutes through a load-lock. A two-microscope imaging system allows visual control of the jets from two perspectives.

Spin Heat Engine Coupled to a Harmonic-Oscillator Flywheel.

We realize a heat engine using a single-electron spin as a working medium. The spin pertains to the valence electron of a trapped ^{40}Ca^{+} ion, and heat reservoirs are emulated by controlling the spin polarization via optical pumping. The engine is coupled to the ion's harmonic-oscillator degree of freedom via spin-dependent optical forces. The oscillator stores the work produced by the heat engine and, therefore, acts as a flywheel. We characterize the state of the flywheel by reconstructing the Husimi Q function of the oscillator after different engine run times. This allows us to infer both the deposited energy and the corresponding fluctuations throughout the onset of operation, starting in the oscillator ground state. In order to understand the energetics of the flywheel, we determine its ergotropy, i.e., the maximum amount of work which can be further extracted from it. Our results demonstrate how the intrinsic fluctuations of a microscopic heat engine fundamentally limit performance.

Endovascular stroke treatment does not preclude high thrombolysis rates.

BACKGROUND AND PURPOSE: In 1995 intravenous recombinant tissue plasminogen activator (IVRTPA) was the first reperfusion therapy to be approved in patients with acute ischaemic stroke (AIS). The significance and impact of IVRTPA in times of modern endovascular stroke treatment (EST) were analysed in a German academic stroke centre. METHODS: A retrospective observational cohort analysis of 1034 patients with suspected AIS presenting at the emergency department in 2014 was performed. Patients were evaluated for baseline characteristics, reperfusion procedures, IVRTPA eligibility, clinical outcome, symptomatic intracranial haemorrhage (sICH) and mortality. Data acquisition was part of an investigator-initiated, prospective and blinded end-point registry. RESULTS: In 718 (69%) patients the diagnosis of symptomatic AIS was confirmed. 419 (58%) patients presented within 4.5 h of symptom onset and of those 260 (62%) received reperfusion therapy (IVRTPA alone, n = 183; combination or bridging therapy, n = 60; EST alone, n = 17). Subtracting cases with absolute contraindications for IVRTPA resulted in an effective thrombolysis rate of 82%. sICH occurred in two patients treated with IVRTPA alone (1.1%). The median door-to-needle interval was 30 min. Fifty (17%) non-EST eligible AIS patients presenting within 4.5 h without absolute contraindications did not receive IVRTPA mainly due to mild or regressive symptoms. Most of these untreated IVRTPA eligible patients (82%) were discharged with a good clinical outcome (modified Rankin Scale ≤ 2). CONCLUSIONS: Intravenous recombinant tissue plasminogen activator remains the most frequently applied reperfusion therapy in AIS patients presenting within 4.5 h of onset in a tertiary stroke centre. An effective thrombolysis rate of over 80% can be achieved without increased rates of sICH.

Fractal morphology, imaging and mass spectrometry of single aerosol particles in flight.

The morphology of micrometre-size particulate matter is of critical importance in fields ranging from toxicology to climate science, yet these properties are surprisingly difficult to measure in the particles' native environment. Electron microscopy requires collection of particles on a substrate; visible light scattering provides insufficient resolution; and X-ray synchrotron studies have been limited to ensembles of particles. Here we demonstrate an in situ method for imaging individual sub-micrometre particles to nanometre resolution in their native environment, using intense, coherent X-ray pulses from the Linac Coherent Light Source free-electron laser. We introduced individual aerosol particles into the pulsed X-ray beam, which is sufficiently intense that diffraction from individual particles can be measured for morphological analysis. At the same time, ion fragments ejected from the beam were analysed using mass spectrometry, to determine the composition of single aerosol particles. Our results show the extent of internal dilation symmetry of individual soot particles subject to non-equilibrium aggregation, and the surprisingly large variability in their fractal dimensions. More broadly, our methods can be extended to resolve both static and dynamic morphology of general ensembles of disordered particles. Such general morphology has implications in topics such as solvent accessibilities in proteins, vibrational energy transfer by the hydrodynamic interaction of amino acids, and large-scale production of nanoscale structures by flame synthesis.

Comprehensive pharmaceutical care to prevent drug-related readmissions of dependent-living elderly patients: a randomized controlled trial.

BACKGROUND: Elderly patients are vulnerable to adverse drug reactions (ADRs). Drug-related readmissions (DRRs) can be a major consequence of ADR. Therefore, this study aimed to investigate the effects of a ward-based, comprehensive pharmaceutical care service on the occurrence of DRRs as the endpoint in dependent-living elderly patients. METHODS: A randomized, controlled trial was performed at a German University Hospital. Patients fulfilling the following criteria were eligible: admission to a cooperating ward, existing drug therapy at admission, 65 years of age and older, home-care or nursing home residents in ambulatory care, and a minimum hospital stay of three days. Patients received either standard care (control group) or pharmaceutical care (intervention group). Follow-up consultations were conducted for each patient at 1, 8, 26, and 52 weeks after discharge. The time to DRR was defined as the primary outcome measure and was analysed using the log-rank test. The Cox-proportional hazard model was used for risk factor analysis. RESULTS: Sixty patients (n = 31 intervention group, n = 29 control group) participated in the study. For patients in the intervention group, the median time to DRR was prolonged; however, the level of statistical significance was not reached (log-rank test P = 0.068; HR = 3.28, P = 0.086). When the risk factors 'age' or 'length of stay on the ward' were added to the Cox proportional hazard model, patients in the control group exhibited a significantly higher risk of experiencing a DRR than patients of the intervention group (HR = 4.62; P = 0.028 including age and HR = 5.76; P = 0.033 including length of stay on the ward). CONCLUSIONS: Our findings demonstrate the successful implementation of ward-based, comprehensive pharmaceutical care for dependent-living elderly. Despite a low participation rate, which led to an underpowered study, the results provide a preliminary efficacy signal and effect size estimates to power a definitive trial. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT01578525 , prospectively registered April 13, 2012.

Investigation into diseases in free-ranging ring-necked pheasants (Phasianus colchicus) in northwestern Germany during population decline with special reference to infectious pathogens.

The population of ring-necked pheasants (Phasianus colchicus) is decreasing all over Germany since the years 2008/2009. Besides impacts of habitat changes caused by current rates of land conversion, climatic influences or predators, a contribution of infectious pathogens needs also to be considered. Infectious and non-infectious diseases in free-living populations of ring-necked pheasants have been scarcely investigated so far. In the present study, carcasses of 258 deceased free-ranging pheasants of different age groups, predominantly adult pheasants, collected over a period of 4 years in the states of Lower Saxony, North Rhine-Westphalia and Schleswig-Holstein, were examined pathomorphologically, parasitologically, virologically and bacteriologically, with a focus set on infectious pathogens. A periocular and perinasal dermatitis of unknown origin was present in 62.3% of the pheasants. Additional alterations included protozoal cysts in the skeletal musculature (19.0%), hepatitis (21.7%), enteritis (18.7%), gastritis (12.6%), and pneumonia (11.7%). In single cases, neoplasms (2.6%) and mycobacteriosis (1.7%) occurred. Further findings included identification of coronaviral DNA from trachea or caecal tonsils (16.8%), siadenoviral DNA (7.6%), avian metapneumoviral RNA (6.6%), and infectious bursal disease viral RNA (3.7%). Polymerase chain reaction (PCR) on herpesvirus, avian influenza virus (AIV), paramyxovirus type 1 (PMV-1), avian encephalomyelitis virus (AEV), and chlamydia were negative. Based on the present results, there is no indication of a specific pathogen as a sole cause for population decline in adult pheasants. However, an infectious disease can still not be completely excluded as it may only affect reproduction effectivity or a certain age group of pheasants (e.g., chicks) which were not presented in the study.

Scalable Creation of Long-Lived Multipartite Entanglement.

We demonstrate the deterministic generation of multipartite entanglement based on scalable methods. Four qubits are encoded in ^{40}Ca^{+}, stored in a microstructured segmented Paul trap. These qubits are sequentially entangled by laser-driven pairwise gate operations. Between these, the qubit register is dynamically reconfigured via ion shuttling operations, where ion crystals are separated and merged, and ions are moved in and out of a fixed laser interaction zone. A sequence consisting of three pairwise entangling gates yields a four-ion Greenberger-Horne-Zeilinger state |ψ⟩=(1/sqrt[2])(|0000⟩+|1111⟩), and full quantum state tomography reveals a state fidelity of 94.4(3)%. We analyze the decoherence of this state and employ dynamic decoupling on the spatially distributed constituents to maintain 69(5)% coherence at a storage time of 1.1 sec.

Effective axillary malodour reduction by polyquaternium-16-containing deodorants.

OBJECTIVE: Worldwide, individuals apply deodorants to combat malodour formation originating from the axillary vault. Considering the globally increasing demand for efficacious, safe deodorants, we investigated the antimicrobial effectiveness of a polymeric quaternary ammonium compound (PQ-16) as a new active in a roll-on formulation against microbial growth and axillary malodour. METHODS: We utilized an in vivo microbiological assessment to determine antimicrobial effects of the PQ-16-containing deodorant formulation (DEO1) (i) in comparison with a commercially available deodorant roll-on claiming a 24-h protection against body odour (DEO2) and (ii) in comparison with a roll-on containing the same formulation as DEO1 but comprising aluminium chlorohydrate instead of PQ-16 (DEO3) 1, 4, 8, 24 and 48 h after treatment. Also, the axillary malodour intensity 24 and 48 h after application of deodorants was investigated in a controlled in vivo study performed by a trained sniffer panel using direct sniffing. RESULTS: Treatment with DEO1 in comparison with application of DEO2 significantly reduced the log 10 bacterial count at all points in time. After 24 and 48 h, sniffers rated malodour production in the DEO1-treated axillae significantly lower than in the DEO2-treated armpits. Application of DEO1 in comparison with DEO3 decreased the log 10 bacterial count after 1, 4, 8 and 24 h (significant for 4 and 8 h). After 48 h, the log 10 bacterial count showed similar values for both DEO1 and DEO3. The sniffer panel reported no significant differences between axillary malodour in DEO1-treated compared to DEO3-treated armpits after 24 and 48 h. CONCLUSION: We identified polyquaternium-16 (PQ-16, copolymers of 1-vinyl-2-pyrrolidone and 1-vinyl-3-methylimidazolium chloride) as a highly effective deodorant active. Results showed that a newly developed PQ-16-containing deodorant roll-on formulation (i) significantly reduced axillary malodour 24 and 48 h after treatment, (ii) significantly decreased the amount of axillary bacteria, (iii) compared to a commercially available deodorant claiming a 24-h odour protection significantly lowered axillary malodour 24 h and 48 h after application, and (iv) was well tolerated by the study population. PQ-16 represents an innovative and skin-friendly deodorant active.

Quantum-Enhanced Sensing Based on Time Reversal of Nonlinear Dynamics.

We experimentally demonstrate a nonlinear detection scheme exploiting time-reversal dynamics that disentangles continuous variable entangled states for feasible readout. Spin-exchange dynamics of Bose-Einstein condensates is used as the nonlinear mechanism which not only generates entangled states but can also be time reversed by controlled phase imprinting. For demonstration of a quantum-enhanced measurement we construct an active atom SU(1,1) interferometer, where entangled state preparation and nonlinear readout both consist of parametric amplification. This scheme is capable of exhausting the quantum resource by detecting solely mean atom numbers. Controlled nonlinear transformations widen the spectrum of useful entangled states for applied quantum technologies.

Phase-Stable Free-Space Optical Lattices for Trapped Ions.

We demonstrate control of the absolute phase of an optical lattice with respect to a single trapped ion. The lattice is generated by off-resonant free-space laser beams, and we actively stabilize its phase by measuring its ac-Stark shift on a trapped ion. The ion is localized within the standing wave to better than 2% of its period. The locked lattice allows us to apply displacement operations via resonant optical forces with a controlled direction in phase space. Moreover, we observe the lattice-induced phase evolution of spin superposition states in order to analyze the relevant decoherence mechanisms. Finally, we employ lattice-induced phase shifts for inferring the variation of the ion position over the 157 µm range along the trap axis at accuracies of better than 6 nm.

Verbal memory declines more in female patients with Parkinson's disease: the importance of gender-corrected normative data.

BACKGROUND: Data on gender-specific profiles of cognitive functions in patients with Parkinson's disease (PD) are rare and inconsistent, and possible disease-confounding factors have been insufficiently considered. METHOD: The LANDSCAPE study on cognition in PD enrolled 656 PD patients (267 without cognitive impairment, 66% male; 292 with mild cognitive impairment, 69% male; 97 with PD dementia, 69% male). Raw values and age-, education-, and gender-corrected Z scores of a neuropsychological test battery (CERAD-Plus) were compared between genders. Motor symptoms, disease duration, l-dopa equivalent daily dose, depression - and additionally age and education for the raw value analysis - were taken as covariates. RESULTS: Raw-score analysis replicated results of previous studies in that female PD patients were superior in verbal memory (word list learning, p = 0.02; recall, p = 0.03), while men outperformed women in visuoconstruction (p = 0.002) and figural memory (p = 0.005). In contrast, gender-corrected Z scores showed that men were superior in verbal memory (word list learning, p = 0.02; recall, p = 0.02; recognition, p = 0.04), while no difference was found for visuospatial tests. This picture could be observed both in the overall analysis of PD patients as well as in a differentiated group analysis. CONCLUSIONS: Normative data corrected for gender and other sociodemographic variables are relevant, since they may elucidate a markedly different cognitive profile compared to raw scores. Our study also suggests that verbal memory decline is stronger in women than in men with PD. Future studies are needed to replicate these findings, examine the progression of gender-specific cognitive decline in PD and define different underlying mechanisms of this dysfunction.

Neurothrombectomy in acute ischaemic stroke: a prospective single-centre study and comparison with randomized controlled trials.

BACKGROUND AND PURPOSE: In the last few months five multicentre, randomized controlled trials (RCTs) unequivocally showed the superiority of mechanical thrombectomy in large vessel occlusion acute ischaemic stroke compared to systemic thrombolysis. Despite varying inclusion criteria and time intervals from onset to revascularization overall increases of good functional outcome between 55% and 81% were reported. However, only a minority of screened patients (approximately 1%) were eligible for intra-arterial (IA) therapy. METHODS: An investigator-initiated, single-centre, prospective and blinded end-point analysis was performed of 3123 consecutive patients with acute ischaemic stroke presenting between February 2010 and December 2014. RESULTS: One hundred and fifty-four patients [4.9%, age (years) mean (SD), median (interquartile range) 71.2 (±14), 74.7 (65.9-81.4)] met the inclusion criteria of sparse early ischaemic signs on initial standard cranial computed tomography (CT) (ASPECT score ≥7), large vessel occlusion in the anterior circulation on CT angiography and start of treatment within 6 h of onset of symptoms. After consensual interdisciplinary treatment decisions 130 patients (4.2%) received IA treatment - in the majority stent-assisted thrombectomy in combination with intravenous (IV) recombinant tissue plasminogen activator - and 24 patients (0.7%) standard IV thrombolysis. On 3 months' follow-up an overall significant improvement of disability (P = 0.05) as measured by the modified Rankin Scale was shown in favour of the IA treatment group. Good functional outcome was achieved in about twice as many patients (IA vs. IV, 41.2% vs. 21.2%; P = 0.078). CONCLUSION: By choosing pragmatic inclusion criteria state-of-the-art IA therapy of a specialized tertiary stroke centre can be safely applied under real-world conditions to a higher percentage of patients with similar success to the recently published RCTs.

Fluorescence and Textural Characterization of Ortho-Amine Tetraphenylporphyrin Covalently Bonded to Organo-Modified Silica Xerogels.

Most of the studies performed with porphyrins involve these species functionalized with peripheral substituents lying on the same macrocyclic molecular plane. The main objective of this work deals with the successful preservation and optimization of the fluorescence of a uncommonly used porphyrin species, i.e. tetrakis-(ortho-amino-phenyl)-porphyrin; a molecule with substituents localized not only at one but at both sides of its molecular plane. In cases like this, it must be stressed that fluorescence can only be partially preserved; nevertheless, intense fluorescence can still be reached by following a twofold functionalization strategy involving: (i) the bonding of substituted macrocycles to the pore walls of (ii) organo-modified silica monoliths synthesized by the sol-gel method. The analysis of both absorption and emission UV spectra evidenced a radiation energy transfer taking place between the porphyrin and the host silica matrix. Our results showed that the adequate displaying of the optical properties of macrocyclic species trapped in SiO2 xerogels depend on the polarity existing inside the pores, a property which can be tuned up through the adequate selection of organic groups used to modify the surface of the pore cavities. Additionally, the pore widths attained in the final xerogels can vary depending on the identity of the organic groups attached to the network. All these facts finally demonstrated that, even if using inefficient surface functionalization species, such as ortho-substituted tetraphenylporphyrins, it is still possible to modulate the pore shape, pore size, and physicochemical environment created around the trapped macrocycles. The most important aspect related to this research deals with the fact that the developed methodology offers a real possibility of controlling both the textural and morphological characteristics of a new kind of hybrid porous materials and to optimize the physicochemical properties of diverse active molecules trapped inside the pores of these materials.

Spectrum, Applicability and Diagnostic Capacity of Contrast-Enhanced Ultrasound in Pediatric Patients and Young Adults after Intravenous Application - A Retrospective Trial.

Purpose: To investigate the spectrum, applicability and diagnostic capacity of intravenous contrast-enhanced ultrasound imaging (CEUS) in a pediatric population. Materials and Methods: From 08/2005 to 11/2015, n = 40 pediatric patients and young adults from 0 - 26 years (Ø 11.4 ±â€Š7.5) and 3.0 - 85.3 kg (Ø 40.8 ± 25.6) with n = 55 investigations received n = 79 IV applications of ultrasound contrast agent (UCA). UCA dose and side effects were documented. Scanned organs were the liver (n = 42), spleen (n = 9), kidney (n = 3), and testis (n = 1). Histology, surgery or reference imaging was compared to CEUS and clinical follow-up. Results: The UCA dose < 20 kg was 0.4 ±â€Š0.3 ml, (0.05 ±â€Š0.02 ml/kg) and > 20 kg was 1.0 ±â€Š0.4 ml (p< 0.0001) (0.02 ±â€Š0.01 ml/kg, p< 0.0001). Adverse effects occurred in 2/79 applications (2.5 %). Agreement CEUS/gold standard resulted in 32/34 investigations. For liver diagnostics (gold standard: MRI, CT, histology, serology), n = 11 malignant and n = 15 benign focal liver lesions were included. The specificity was 100 % (95 % CI: 0.77 - 1.00), the sensitivity was 82 % (95 % CI: 0.48 - 0.98), the positive predictive value was 100 % (95 % CI: 0.69 - 1.00) and the negative predictive value was 88 % (95 % CI: 0.62 - 0.98, p< 0.0001). In n = 2 reference imaging misdiagnosed and CEUS was in accordance with clinical follow-up. All splenic/renal lesions were diagnosed correctly. In n = 1 an insufficient testicular perfusion was ruled out. The observation time was 30.4 ±â€Š30.5 months. Conclusion: CEUS is a well-tolerated and diagnostically equivalent modality in pediatric care, providing fundamental advantages compared to currently approved imaging modalities for these age groups.

Chlorophyll a Covalently Bonded to Organo-Modified Translucent Silica Xerogels: Optimizing Fluorescence and Maximum Loading.

Chlorophyll is a pyrrolic pigment with important optical properties, which is the reason it has been studied for many years. Recently, interest has been rising with respect to this molecule because of its outstanding physicochemical properties, particularly applicable to the design and development of luminescent materials, hybrid sensor systems, and photodynamic therapy devices for the treatment of cancer cells and bacteria. More recently, our research group has been finding evidence for the possibility of preserving these important properties of substrates containing chlorophyll covalently incorporated within solid pore matrices, such as SiO2, TiO2 or ZrO2 synthesized through the sol-gel process. In this work, we study the optical properties of silica xerogels organo-modified on their surface with allyl and phenyl groups and containing different concentrations of chlorophyll bonded to the pore walls, in order to optimize the fluorescence that these macrocyclic species displays in solution. The intention of this investigation was to determine the maximum chlorophyll a concentration at which this molecule can be trapped inside the pores of a given xerogel and to ascertain if this pigment remains trapped as a monomer, a dimer, or aggregate. Allyl and phenyl groups were deposited on the surface of xerogels in view of their important effects on the stability of the molecule, as well as over the fluorescence emission of chlorophyll; however, these organic groups allow the trapping of either chlorophyll a monomers or dimers. The determination of the above parameters allows finding the most adequate systems for subsequent in vitro or in vivo studies. The characterization of the obtained xerogels was performed through spectroscopic absorption, emission and excitation spectra. These hybrid systems can be employed as mimics of natural systems; the entrapment of chlorophyll inside pore matrices indicates that it is possible to exploit some of the most physicochemical properties of trapped chlorophyll for diverse technological applications. The data herein collected suggest the possibility of applying the developed methodology to other active, captive molecules in order to synthesize new hybrid materials with optimized properties, suitable to be applied in diverse technological fields.

Increasing the field of view in grating based X-ray phase contrast imaging using stitched gratings.

Grating based X-ray differential phase contrast imaging (DPCI) allows for high contrast imaging of materials with similar absorption characteristics. In the last years' publications, small animals or parts of the human body like breast, hand, joints or blood vessels have been studied. Larger objects could not be investigated due to the restricted field of view limited by the available grating area. In this paper, we report on a new stitching method to increase the grating area significantly: individual gratings are merged on a carrier substrate. Whereas the grating fabrication process is based on the LIGA technology (X-ray lithography and electroplating) different cutting and joining methods have been evaluated. First imaging results using a 2×2 stitched analyzer grating in a Talbot-Lau interferometer have been generated using a conventional polychromatic X-ray source. The image quality and analysis confirm the high potential of the stitching method to increase the field of view considerably.