X-ray spectroscopy station for sample characterization at ELI Beamlines

X-ray spectroscopy is a demanded tool across multiple user communities. Here we report on a new station for X-ray emission spectroscopy at the Extreme Light Infrastructure Beamlines Facility. The instrument utilizes the von Hamos geometry and works with a number of different sample types, notably including liquid systems. We demonstrate a simple and reliable method for source position control using two cameras. This approach addresses energy calibration dependence on sample position, which is a characteristic source of measurement uncertainty for wavelength dispersive spectrometers in XES arrangement. We also present a straightforward procedure for energy calibration of liquid and powder samples to a thin film reference. The developed instrumentation enabled us to perform the first experimental determination of the Kα lines of liquidized K3Fe(CN)6 as well as powdered and liquidized FeNH4(SO4)2. Finally, we report on proof-of-principle use of a colliding jet liquid sample delivery system in an XES experiment.

Nanotechnology for catalysis and solar energy conversion

This roadmap on Nanotechnology for Catalysis and Solar Energy Conversion focuses on the application of nanotechnology in addressing the current challenges of energy conversion: 'high efficiency, stability, safety, and the potential for low-cost/scalable manufacturing' to quote from the contributed article by Nathan Lewis. This roadmap focuses on solar-to-fuel conversion, solar water splitting, solar photovoltaics and bio-catalysis. It includes dye-sensitized solar cells (DSSCs), perovskite solar cells, and organic photovoltaics. Smart engineering of colloidal quantum materials and nanostructured electrodes will improve solar-to-fuel conversion efficiency, as described in the articles by Waiskopf and Banin and Meyer. Semiconductor nanoparticles will also improve solar energy conversion efficiency, as discussed by Boschloo et al in their article on DSSCs. Perovskite solar cells have advanced rapidly in recent years, including new ideas on 2D and 3D hybrid halide perovskites, as described by Spanopoulos et al 'Next generation' solar cells using multiple exciton generation (MEG) from hot carriers, described in the article by Nozik and Beard, could lead to remarkable improvement in photovoltaic efficiency by using quantization effects in semiconductor nanostructures (quantum dots, wires or wells). These challenges will not be met without simultaneous improvement in nanoscale characterization methods. Terahertz spectroscopy, discussed in the article by Milot et al is one example of a method that is overcoming the difficulties associated with nanoscale materials characterization by avoiding electrical contacts to nanoparticles, allowing characterization during device operation, and enabling characterization of a single nanoparticle. Besides experimental advances, computational science is also meeting the challenges of nanomaterials synthesis. The article by Kohlstedt and Schatz discusses the computational frameworks being used to predict structure-property relationships in materials and devices, including machine learning methods, with an emphasis on organic photovoltaics. The contribution by Megarity and Armstrong presents the 'electrochemical leaf' for improvements in electrochemistry and beyond. In addition, biohybrid approaches can take advantage of efficient and specific enzyme catalysts. These articles present the nanoscience and technology at the forefront of renewable energy development that will have significant benefits to society.

A metal-free blue chromophore derived from plant pigments

Blue natural pigments are rare, especially among plants. However, flowering species that evolved to attract Hymenoptera pollinators are colored by blue anthocyanin-metal complexes. Plants lacking anthocyanins are pigmented by betalains but are unable to produce blue hues. By extending the π-system of betalains, we designed a photostable and metal-free blue dye named BeetBlue that did not show toxicity to human hepatic and retinal pigment epithelial cells and does not affect zebrafish embryonal development. This chiral dye can be conveniently synthesized from betalamic acid obtained from hydrolyzed red beetroot juice or by enzymatic oxidation of l-dopa. BeetBlue is blue in the solid form and in solution of acidified polar molecular solvents, including water. Its capacity to dye natural matrices makes BeetBlue the prototype of a new class of low-cost bioinspired chromophores suitable for a myriad of applications requiring a blue hue.

Inception of electronic damage of matter by photon-driven post-ionization mechanisms

"Probe-before-destroy" methodology permitted diffraction and imaging measurements of intact specimens using ultrabright but highly destructive X-ray free-electron laser (XFEL) pulses. The methodology takes advantage of XFEL pulses ultrashort duration to outrun the destructive nature of the X-rays. Atomic movement, generally on the order of >50 fs, regulates the maximum pulse duration for intact specimen measurements. In this contribution, we report the electronic structure damage of a molecule with ultrashort X-ray pulses under preservation of the atoms' positions. A detailed investigation of the X-ray induced processes revealed that X-ray absorption events in the solvent produce a significant number of solvated electrons within attosecond and femtosecond timescales that are capable of coulombic interactions with the probed molecules. The presented findings show a strong influence on the experimental spectra coming from ionization of the probed atoms' surroundings leading to electronic structure modification much faster than direct absorption of photons. This work calls for consideration of this phenomenon in cases focused on samples embedded in, e.g., solutions or in matrices, which in fact concerns most of the experimental studies.

Effective catalytic disproportionation of aqueous H2O2 with di- and mono-nuclear manganese(II) complexes containing pyridine alcohol ligands

The two novel manganese(II) complexes with 2-hydroxymethylpyridine (2-CH2OHpy) {[Mn2(μ-Cl)2(2-CH2OHpy)4]Cl2·2H2O (1)} and 2-hydroxyethylpyridine (2-(CH2)2OHpy) {[Mn(2-(CH2)2OHpy)2(NCS)2] (2)} were synthesized and characterized by means of X-ray diffraction, IR, EPR, HF EPR spectroscopy, magnetic and TG/DTG data. The complexes show catalase-like activity in neutral aqueous solution since they were able to disproportionate H2O2 to harmless H2O and O2. Both complexes act as true catalysts since they reverted to their original form after depleting all the H2O2, as suggested by the operando resonant inelastic X-ray spectroscopy (RIXS) measurements.

A 3D printed microliquid jet with an adjustable nozzle diameter

Microliquid jets have many applications, in particular in the fields of spectroscopy/analysis of samples susceptible to beam damage.

High energy resolution off-resonant spectroscopy for x-ray absorption spectra free of self-absorption effects

X-ray emission spectra recorded in the off-resonant regime carry information on the density of unoccupied states. It is known that by employing the Kramers-Heisenberg formalism, the high energy resolution off-resonant spectroscopy (HEROS) is equivalent to the x-ray absorption spectroscopy (XAS) technique and provides the same electronic state information. Moreover, in the present Letter we demonstrate that the shape of HEROS spectra is not modified by self-absorption effects. Therefore, in contrast to the fluorescence-based XAS techniques, the recorded shape of the spectra is independent of the sample concentration or thickness. The HEROS may thus be used as an experimental technique when precise information about specific absorption features and their strengths is crucial for chemical speciation or theoretical evaluation.

A novel microdeletion syndrome at 3q13.31 characterised by developmental delay, postnatal overgrowth, hypoplastic male genitals, and characteristic facial features

BACKGROUND

Congenital deletions affecting 3q11q23 have rarely been reported and only five cases have been molecularly characterised. Genotype-phenotype correlation has been hampered by the variable sizes and breakpoints of the deletions. In this study, 14 novel patients with deletions in 3q11q23 were investigated and compared with 13 previously reported patients.

METHODS

Clinical data were collected from 14 novel patients that had been investigated by high resolution microarray techniques. Molecular investigation and updated clinical information of one cytogenetically previously reported patient were also included.

RESULTS

The molecular investigation identified deletions in the region 3q12.3q21.3 with different boundaries and variable sizes. The smallest studied deletion was 580 kb, located in 3q13.31. Genotype-phenotype comparison in 24 patients sharing this shortest region of overlapping deletion revealed several common major characteristics including significant developmental delay, muscular hypotonia, a high arched palate, and recognisable facial features including a short philtrum and protruding lips. Abnormal genitalia were found in the majority of males, several having micropenis. Finally, a postnatal growth pattern above the mean was apparent. The 580 kb deleted region includes five RefSeq genes and two of them are strong candidate genes for the developmental delay: DRD3 and ZBTB20.

CONCLUSION

A newly recognised 3q13.31 microdeletion syndrome is delineated which is of diagnostic and prognostic value. Furthermore, two genes are suggested to be responsible for the main phenotype.

[Thrombolytic therapy in acute myocardial infarct: the reasons for ineligibility]

STUDY OBJECTIVE

to establish the reasons of ineligibility for thrombolytic therapy (TL) in a group of patients with acute myocardial infarction (AMI).

DESIGN

retrospective analysis of protocols and clinical records.

SETTING

the medical intensive care unit (ICU) of a tertiary care hospital.

PATIENTS AND METHODS

we studied the records from patients with AMI admitted to the ICU during a five-year period (1987-91) and excluded from TL, to determine the cause(s) of ineligibility.

RESULTS

we found 1669 patients with AMI, 89 of which were excluded from the study. Of the remaining 1580 patients, 1274 (80.6%) did not receive TL. Mean age was 64.4 years; 66.4% were men. Mortality was 24.6%. Mean duration of chest pain was 19.4 hours. Chief reasons for exclusion from TL were advanced age (43.1% of patients) and delayed presentation (55.7%); one of these was present in 79.2%.

CONCLUSIONS

this study confirmed the high mortality of patients with AMI who do not receive TL. Advanced age and delayed presentation were the main causes of ineligibility. As age is being abandoned as an exclusion criterion, efforts for expansion of TL should center on the earlier arrival of patients to centers where it is available.

[Vasculitis associated with ANCA]

The authors present a case report of a 62-year old woman, with hypertension for many years. She suffered from weakness, anorexia and weight loss in the last 6 months. On admission, anemia, elevated ESR, haematuria, proteinuria and renal failure were present. Renal biopsy was compatible with chronic glomerulonephritis. The clinical picture and positivity for P-ANCA suggested systemic vasculitis. Later evidence of maxillary sinusitis and nasal mucosae ulcers as well as pneumonitis, although biopsy did not reveal granulomas, suggested the diagnosis of Wegener Vasculitis. Medicated with Cyclophosphamide and Prednisolone, for a year, with improvement. The authors make a brief discussion of the clinical criteria for classification of ANCA-associated systemic vasculitis.

[Cor pulmonale caused by neoplasm cell embolism]

The authors describe a case of Cor Pulmonale due to Tumor Cell Embolization in a 42-year-old woman with no history of antecedent malignant disease. The primary tumor was a Choriocarcinoma which could not be found in postmortem examination. The pathophysiology, clinical manifestations and diagnostic evaluation of this entity are briefly discussed.

[Surgical and trauma patients in a medical intensive care unit]

OBJECTIVE

to characterize and to assess in terms of severity the surgical and trauma patients admitted to a medical intensive care unit (ICU).

DESIGN

retrospective study base on clinical records and the ICU computerized database.

SETTING

the medical ICU of a tertiary hospital.

RESULTS

of the 2468 patients admitted to the ICU in 1989, 289 (11.7%) were surgical or trauma ones. The more frequent reasons for admission were: the need for mechanical ventilation, metabolic problems, and depression of consciousness. Of these 289 patients, 48.1% required mechanical ventilation, 14.9 hemodialysis; 4.8% had a pulmonary artery catheter inserted. Mean APACHE II, TISS and MOF scores were high (20.09 +/- 9.29, 24.17 +/- 11.45 and 5.4 +/- 3.59); they were determined in 79.2, 88.2 and 43.9% of patients respectively. Both APACHE and TISS scores were correlated with mortality. When compared with medical patients, surgical/trauma ones although younger (52.9 +/- 20.7 years versus 55.9 +/- 20.2, p = 0.00152), had a longer mean stay in the ICU (7.63 +/- 12.7 days v. 3.64 +/- 7.61, p = 0.0001), and a higher mortality (also in the ICU) (28.7 v. 16.7, p = 0.0005.

COMMENTS

these are seriously ill patients, who are frequently referred to the ICU in late stages of clinical evolution. We propose they should be closely followed, from the earliest possible stage, by medical-surgical teams, in order to benefit from a multidisciplinary approach.

[Poisoning at a polyvalent intensive care unit]

A retrospective analysis was made concerning 1340 admissions to a multidisciplinary Intensive Care Unit over four years (1986-1989), because of acute poisoning. In 666 patients occurred 735 drug overdoses and in 674 patients, 691 non-drug intoxications. The drugs with main action in central nervous system were the most frequent in drug overdoses and the organophosphates insecticides in the non-drug intoxications. During the considered period there was an absolute and relative fall in the number of admissions for acute poisoning (480 vs 244, 15.1% vs 9.9%). The patients admitted were 698 men (289 in drug-overdoses and 409 in non-drug group) with a statistically significant difference between the type of intoxication and sex (p less than 0.001). Age mean was 40.2 +/- 19.6 years, almost the same in the two groups of intoxications. The peak incidence occurred from March to October. From the hospital area of Lisbon came 814 patients and outside of Lisbon 495 patients. The mean duration of stay in the ICU was 3.90 +2- 6.15 days, being 2.71 +/- 3.80 in the drug overdoses and 5.08 +/- 7.62 in non-drug intoxications (p less than 0.001). From the therapeutic measures we emphasize mechanical ventilation (29.5%), total parenteral nutrition (18.5%), dialysis (2.9%), Swan-Ganz catheter (2.8%) and pacemaker (1.2%). The mortality rate was 13.7%, higher in non-drug intoxications (23.0%) than in drug overdoses (4.4%) (p less than 0.0001).

[Importance of magnetic resonance in Parkinson disease. An analytic study of the pars compacta]

The authors have studied by high field MR (Signa 1.5 T, GE) 11 patients with known Parkinson's disease and 19 normal controls. In all cases the widths of the pars compacta were measured by optical densitometry in T2-weighted images (gradient-echo TR 2600, TE 80). In Parkinson's patients the compactae of the nigra were found to be significantly thinned (p less than 0.01) which may be of importance for the discussion of the physicopathology and clinic of the extrapyramidal disease.