Correction: Batch-produced, GIS-informed range maps for birds based on provenanced, crowd-sourced data inform conservation assessments

[This corrects the article DOI: 10.1371/journal.pone.0259299.].

Influence of working conditions and salary on agency work for intermediate and intensive care units

Background

Agency work in nursing is used as a form of labor to counter vacant staff positions in hospitals. Both hospital owners and nurses view this critically for different reasons.

Aim

The aim of this study was to assess what personal net income nurses in German intensive care units and intermediate care units consider “fair and sufficient” for their work (addressed in Part 1 of the survey) and what influence—aside from the salary—the working conditions have on the willingness to change to temporary work or back to a permanent position.

Methods

From September to October 2020, an anonymous online survey was conducted among nurses of intermediate care units, intensive care units, and special care units in German-speaking countries. Descriptive statistics were used for the analysis.

Result

Of 1203 participants, 86% (n = 1036) could be evaluated. None of the job satisfaction factors queried received four or five stars (maximum five stars) from those participating in the survey. The most unsatisfied group proved to be regularly employed nurses with an additional part-time job. Key job satisfaction factors differed markedly between the groups, with regular employees favoring consistency and stability. Agency workers prefer gaining experience in a broader range of tasks. Unreliable duty rosters and poor nurse to patient ratios were common points of criticism.

Conclusion

For job satisfaction, making nurses feel appreciated and respected is essential. This includes a guaranteed nurse to patient ratio and reliable duty rosters that also include tasks outside direct patient care. In order for nurses to leave agency work, it is necessary to take into account the differences in interests in terms of the focus of activity.

[Intensive care of patients with [infarct-related] cardiogenic shock : Abridged version of the S1 guideline]

BACKGROUND

Cardiovascular diseases and (infarct-related) cardiogenic shock are among the most frequent causes of death in Germany. Adequate clinical care often poses great challenges for hospitals. The complex care of patients in a multi-professional team places high demands on all those involved in the care process. Since nurses in particular are in close contact with patients and play a decisive role in shaping and controlling therapy, a national (intensive) care guideline is urgently needed.

METHODS

Within the framework of the guideline programme of the Association of the Scientific Medical Societies in Germany (AWMF), an S1 guideline was developed with the participation of six professional societies and published in May 2022. The guideline group defined relevant topics, which were processed through a systematic literature search in peer-reviewed journals. Based on the S1 classification, no separate evidence review was conducted. A formal consensus-building process was used to classify the recommendations.

RESULTS

The guideline contains 36 recommendations ranging from nursing care in the central emergency department to the cardiac catheterisation laboratory, intensive care unit and follow-up care. In addition, recommendations are made on the necessary qualifications and structural requirements in the respective areas in order to ensure a high-quality (nursing) care process.

CONCLUSION

This is the first national intensive care guideline. It is aimed at nurses involved in the care of patients with (infarct-related) cardiogenic shock. The guideline is valid until 30.12.2026.

Einfluss der Arbeitsbedingungen und des Gehalts auf die Leiharbeit für Intermediate-Care- und Intensivstationen

Hintergrund

Leiharbeit in der Pflege wird als Arbeitsform verwendet, um offenen Personalstellen in Kliniken zu begegnen. Sowohl Krankenhausträger als auch Pflegekräfte sehen dies aus unterschiedlichen Gründen kritisch.

Ziel

Zweck dieser Untersuchung war es herauszufinden, welches persönliche Nettoeinkommen Pflegekräfte von deutschen Intensivstationen und Intermediate-Care-Stationen als „gerecht und ausreichend“ für ihre Tätigkeit empfinden und welchen Einfluss das Gehalt auf die Wechselwilligkeit in die Leih‑/Zeitarbeit bzw. wieder zurück in eine Festanstellung haben.

Methode

Von September bis Oktober 2020 wurde eine anonymisierte Onlineumfrage unter Pflegenden von Intermediate-Care-Stationen, Intensivstationen und Funktionsbereichen im deutschsprachigen Raum durchgeführt. Die Auswertung erfolgte mittels deskriptiver Statistik.

Ergebnis

Von 1203 Teilnehmer_innen (TN) konnten 1036 (86 %) in Deutschland Arbeitende ausgewertet werden. Die Frage nach dem persönlichen Nettoeinkommen wurde von 1032 (99 %) TN beantwortet. Der überwiegende Anteil der Befragten (n = 522) gibt an, über ein persönliches Nettoeinkommen von 2000–2999 €/Monat zu verfügen. Der Wunsch, in die Leiharbeit zu gehen, ist in der untersuchten Stichprobe geringer, je höher das persönliche Nettoeinkommen ist. Die TN in Festanstellung ohne Nebenerwerb empfinden ein persönliches Nettoeinkommen von 3200 €/Monat (Median 3200 €; IQR 2800–3800 €) als ausreichend und gerecht für ihre Tätigkeit. Von den Leiharbeiter_innen gaben 142 Personen an, dass ein persönliches Nettoeinkommen von 3200 €/Monat (Median 3200 €; Interquartilsabstand 3000–3950 €) ausreichend wäre, um von der Leiharbeit zurück in eine Festanstellung zu wechseln.

Schlussfolgerung

Die Intensivpflegenden dieser Umfrage empfinden ein Gehalt von 3200 €/Monat netto als ausreichend und gerecht für ihre Tätigkeit. Die Gehaltshöhe kann ein Parameter für die Entscheidung sein, in die Leiharbeit zu gehen, aber auch um wieder in die Festanstellung zu wechseln. Unabhängig vom Gehalt wurden bessere Arbeitsbedingungen für alle befragten Gruppen als essenzieller Bestandteil in Bezug auf die Arbeitszufriedenheit angegeben.

Testing a global standard for quantifying species recovery and assessing conservation impact

Recognizing the imperative to evaluate species recovery and conservation impact, in 2012 the International Union for Conservation of Nature (IUCN) called for development of a "Green List of Species" (now the IUCN Green Status of Species). A draft Green Status framework for assessing species' progress toward recovery, published in 2018, proposed 2 separate but interlinked components: a standardized method (i.e., measurement against benchmarks of species' viability, functionality, and preimpact distribution) to determine current species recovery status (herein species recovery score) and application of that method to estimate past and potential future impacts of conservation based on 4 metrics (conservation legacy, conservation dependence, conservation gain, and recovery potential). We tested the framework with 181 species representing diverse taxa, life histories, biomes, and IUCN Red List categories (extinction risk). Based on the observed distribution of species' recovery scores, we propose the following species recovery categories: fully recovered, slightly depleted, moderately depleted, largely depleted, critically depleted, extinct in the wild, and indeterminate. Fifty-nine percent of tested species were considered largely or critically depleted. Although there was a negative relationship between extinction risk and species recovery score, variation was considerable. Some species in lower risk categories were assessed as farther from recovery than those at higher risk. This emphasizes that species recovery is conceptually different from extinction risk and reinforces the utility of the IUCN Green Status of Species to more fully understand species conservation status. Although extinction risk did not predict conservation legacy, conservation dependence, or conservation gain, it was positively correlated with recovery potential. Only 1.7% of tested species were categorized as zero across all 4 of these conservation impact metrics, indicating that conservation has, or will, play a role in improving or maintaining species status for the vast majority of these species. Based on our results, we devised an updated assessment framework that introduces the option of using a dynamic baseline to assess future impacts of conservation over the short term to avoid misleading results which were generated in a small number of cases, and redefines short term as 10 years to better align with conservation planning. These changes are reflected in the IUCN Green Status of Species Standard.

Batch-produced, GIS-informed range maps for birds based on provenanced, crowd-sourced data inform conservation assessments

Accurate maps of species ranges are essential to inform conservation, but time-consuming to produce and update. Given the pace of change of knowledge about species distributions and shifts in ranges under climate change and land use, a need exists for timely mapping approaches that enable batch processing employing widely available data. We develop a systematic approach of batch-processing range maps and derived Area of Habitat maps for terrestrial bird species with published ranges below 125,000 km2 in Central and South America. (Area of Habitat is the habitat available to a species within its range.) We combine existing range maps with the rapidly expanding crowd-sourced eBird data of presences and absences from frequently surveyed locations, plus readily accessible, high resolution satellite data on forest cover and elevation to map the Area of Habitat available to each species. Users can interrogate the maps produced to see details of the observations that contributed to the ranges. Previous estimates of Areas of Habitat were constrained within the published ranges and thus were, by definition, smaller-typically about 30%. This reflects how little habitat within suitable elevation ranges exists within the published ranges. Our results show that on average, Areas of Habitat are 12% larger than published ranges, reflecting the often-considerable extent that eBird records expand the known distributions of species. Interestingly, there are substantial differences between threatened and non-threatened species. Some 40% of Critically Endangered, 43% of Endangered, and 55% of Vulnerable species have Areas of Habitat larger than their published ranges, compared with 31% for Near Threatened and Least Concern species. The important finding for conservation is that threatened species are generally more widespread than previously estimated.

[Core curriculum Medical intensive care medicine of the German Society of Medical Intensive Care and Emergency Medicine (DGIIN)]

Medical intensive care medicine treats patients with severe, potentially life-threatening diseases covering the complete spectrum of internal medicine. The qualification in medical intensive care medicine requires a broad spectrum of knowledge and skills in medical intensive care medicine, but also in the general field of internal medicine. Both sides of the coin must be taken into account, the treatment with life-sustaining strategies of the acute illness of the patient and also the treatment of patient's underlying chronic diseases. The indispensable foundation of medical intensive care medicine as described in this curriculum includes basic knowledge and skills (level of competence I-III) as well as of behavior and attitudes. This curriculum is primarily dedicated to the internist in advanced training in medical intensive care medicine. However, this curriculum also intends to reach trainers in intensive care medicine and also the German physician chambers with their examiners, showing them which knowledge, skills as well as behavior and attitudes should be taught to trainees according to the education criteria of the German Society of Medical Intensive Care and Emergency Medicine (DGIIN).

Projected impacts of climate change on habitat availability for an endangered parakeet

In tropical montane cloud forests, climate change can cause upslope shifts in the distribution ranges of species, leading to reductions in distributional range. Endemic species with small ranges are particularly vulnerable to such decreases in range size, as the population size may be reduced significantly. To ensure the survival of cloud forest species in the long term, it is crucial to quantify potential future shifts in their distribution ranges and the related changes in habitat availability in order to assure the long-term effectiveness of conservation measures. In this study, we assessed the influence of climate change on the availability of forested habitat for the endemic El Oro parakeet. We investigated the future range shift by modelling the climatic niche of the El Oro parakeets and projecting it to four different climate change scenarios. Depending on the intensity of climate change, the El Oro parakeets shift their range between 500 and 1700 m uphill by the year 2100. On average, the shift is accompanied by a reduction in range size to 15% and a reduction in forested habitat to only 10% of the original extent. Additionally, the connectivity between populations in different areas is decreasing in higher altitudes. To prevent a population decline due to habitat loss following an upslope range shift, it will be necessary to restore habitat across a large elevational span in order to allow for movement of El Oro parakeets into higher altitudes.

[Positioning therapy and early mobilization in intensive care units : Findings from the current 2015 guidelines]

The 2007 guidelines "Positioning for prophylaxis and therapy of pulmonary disorders" were completely revised in 2015 on behalf of the German Society of Anaesthesiology and Intensive Care Medicine. With regard to practical and scientific relevance, early mobilization of patients in critical care has been included in the guidelines for the first time. Furthermore, the recommendations for prone positioning have been updated, based on current evidence in medicine and nursing. In addition, recommendations regarding unsuitable positions that may actually harm patients were made. As such, the flat supine position should only be used in cases of urgent medical or nursing needs. This underlines the importance of a moderately elevated head of bed position (20(o)-45(o)) in mechanically ventilated patients.

[Short version S2e guidelines: "Positioning therapy and early mobilization for prophylaxis or therapy of pulmonary function disorders"]

The German Society of Anesthesiology and Intensive Care Medicine (DGAI) commissioned a revision of the S2 guidelines on "positioning therapy for prophylaxis or therapy of pulmonary function disorders" from 2008. Because of the increasing clinical and scientific relevance the guidelines were extended to include the issue of "early mobilization" and the following main topics are therefore included: use of positioning therapy and early mobilization for prophylaxis and therapy of pulmonary function disorders, undesired effects and complications of positioning therapy and early mobilization as well as practical aspects of the use of positioning therapy and early mobilization. These guidelines are the result of a systematic literature search and the subsequent critical evaluation of the evidence with scientific methods. The methodological approach for the process of development of the guidelines followed the requirements of evidence-based medicine, as defined as the standard by the Association of the Scientific Medical Societies in Germany. Recently published articles after 2005 were examined with respect to positioning therapy and the recently accepted aspect of early mobilization incorporates all literature published up to June 2014.

S2e guideline: positioning and early mobilisation in prophylaxis or therapy of pulmonary disorders : Revision 2015: S2e guideline of the German Society of Anaesthesiology and Intensive Care Medicine (DGAI)

The German Society of Anesthesiology and Intensive Care Medicine (DGAI) commissioneda revision of the S2 guidelines on "positioning therapy for prophylaxis or therapy of pulmonary function disorders" from 2008. Because of the increasing clinical and scientificrelevance the guidelines were extended to include the issue of "early mobilization"and the following main topics are therefore included: use of positioning therapy and earlymobilization for prophylaxis and therapy of pulmonary function disorders, undesired effects and complications of positioning therapy and early mobilization as well as practical aspects of the use of positioning therapy and early mobilization. These guidelines are the result of a systematic literature search and the subsequent critical evaluation of the evidence with scientific methods. The methodological approach for the process of development of the guidelines followed the requirements of evidence-based medicine, as defined as the standard by the Association of the Scientific Medical Societies in Germany. Recently published articles after 2005 were examined with respect to positioning therapy and the recently accepted aspect of early mobilization incorporates all literature published up to June 2014.

[Early mobilization. Competencies, responsibilities, milestones]

BACKGROUND

Early mobilization is an evident, interprofessional concept to improve the outcome of intensive care patients. It reduces psychocognitive deficits and delirium and attenuates a general deconditioning, including atrophy of the respiratory pump and skeletal muscles. In this regard the interdisciplinary approach of early mobilization, taking into account different levels of mobilization, appears to be beneficial. The purpose of this study was to explore opinions on collaboration and tasks between different professional groups.

METHOD

During the 25th Bremen Conference on Intensive Medicine and Nursing on 20 February 2015, a questionnaire survey was carried out among the 120 participants of the German Early Mobilization Network meeting.

RESULTS

In all, 102 questionnaires were analyzed. Most participants reported on the interdisciplinarity of the approach, but none of the tasks and responsibilities concerning early mobilization can be assigned to a single professional group. The practical implementation of mobilizing orally intubated patients may require two registered nurses as well as a physical therapist. Implementation in daily practice seems to be heterogeneous.

CONCLUSIONS

There is no consensus regarding collaboration, competencies, and responsibilities with respect to early mobilization of intensive care patients. The approach to date has been characterized by a lack of interprofessional communication, which may lead to an inefficient use of the broad and varied base of knowledge and experienceof the different professions.

[Tolerance of endotracheal tubes in patients on mechanical ventilation]

BACKGROUND

Modern concepts for sedation and analgesia and guidelines recommend light analgesia and sedation, so that patients on mechanically ventilation are more awake, compared to previous concepts. Hence, these patients are more alert and able to experience their situation on the ventilator and their endotracheal tube (ETT).

PROBLEM

There is currently no convincing evidence of how patients tolerate the tube under present conditions, which interventions could help them, or whether they want to be sedated deeper because of the tube. Based upon our own observations, a broad range of reactions are possible.

PURPOSE

The tolerance of the ETT in intensive care patients was explored.

METHOD

A systematic literature research without time constraints in the databases PubMed and CINAHL was performed. Included were quantitative and qualitative studies written in German or English that investigated tolerance of the ETT in adult intensive care patients. Excluded were anesthetic studies including in- and extubation immediately before and after operations.

RESULTS

Of the 2348 hits, 14 studies were included, including 4 qualitative studies about the experience of intensive care, 8 quantitative studies including 2 randomized controlled studies, and 2 studies with a mixed approach. Within the studies different aspects could be identified, which may in- or decrease the tolerance of an ETT. Aspects like breathlessness, pain during endotracheal suctioning and inability to speak decrease the tolerance. Information, the presence of relatives and early mobilization appear to increase the tolerance.

CONCLUSION

Tolerance of the ETT is a complex phenomenon. A reflected and critical evaluation of the behavior of the patient with an ETT is recommended. Interventions that increase the tolerance of the ETT should be adapted to the situation of the patient and should be evaluated daily.

[Wasp-sting-induced pheochromozytoma crisis with stress-related cardiomyopathy (Takotsubo)]

This article presents the case of a patient with sudden onset of heart failure caused by transient severe left ventricular dysfunction with the typical pattern of stress-induced cardiomyopathy (takotsubo cardiomyopathy) who had wasp sting a few hours before admission in the presence of a previously asymptomatic pheochromocytoma. There seems to be correlation between the wasp-venom-induced pheochomocytoma crisis and acute onset of heart failure. Once pheocromocytoma is diagnosed, medical therapy is preferable before surgical treatment. This case demonstrates that a previously asymptomatic pheochromocytoma can become clinically relevant by catecholamine-releasing wasp venom causing stress-related cardiomyopathy and that patient history is mandatory for evaluating the cause of sudden clinical outcome.

Individual differences in migratory behavior shape population genetic structure and microhabitat choice in sympatric blackcaps (Sylvia atricapilla)

In migratory birds, traits such as orientation and distance are known to have a strong genetic background, and they often exhibit considerable within-population variation. How this variation relates to evolutionary responses to ongoing selection is unknown because the underlying mechanisms that translate environmental changes into population genetic changes are unclear. We show that within-population genetic structure in southern German blackcaps (Sylvia atricapilla) is related to individual differences in migratory behavior. Our 3-year study revealed a positive correlation between individual migratory origins, denoted via isotope (δ²H) values, and genetic distances. Genetic diversity and admixture differed not only across a recently established migratory polymorphism with NW- and SW-migrating birds but also across δ²H clusters within the same migratory route. Our results suggest assortment based on individual migratory origins which would facilitate evolutionary responses. We scrutinized arrival times and microhabitat choice as potential mechanisms mediating between individual variation in migratory behavior and assortment. We found significant support that microhabitat choice, rather than timing of arrival, is associated with individual variation in migratory origins. Moreover, examining genetic diversity across the migratory divide, we found migrants following the NW route to be genetically more distinct from each other compared with migrants following the traditional SW route. Our study suggests that migratory behavior shapes population genetic structure in blackcaps not only across the migratory divide but also on an individual level independent of the divide. Thus, within-population variation in migratory behavior might play an important role in translating environmental change into genetic change.

[Methods for endotracheal tube fixation. Results of a survey of intensive care nurses]

There are a wide variety of strategies and methods used in securing and managing the oral endotracheal tube and mouth and oral care in German clinical intensive care nursing for mechanically ventilated patients. There are no nationally recognized guidelines or recommendations on this topic. A survey among intensive care nurses identified the most widely used nursing strategies and methods. Regarding the results of the survey and international literature findings, the commonly used strategies and methods are discussed. Following these discussions, there are recommendations for improving nursing care of orally intubated patients in intensive care, including the aspects of evidence identified, currently used methods and patient needs. Also included are aspects of patient safety, potential complications and quality-orientated nursing care within a system having limited overall nursing care resources.

Overview of the tunable beamlines for protein crystallography at the EMBL Hamburg Outstation; an analysis of current and future usage and developments

The EMBL Hamburg Outstation currently operates two tunable protein crystallography beamlines suitable for single and multiple anomalous diffraction (SAD/MAD) experiments. The first beamline, designated X31, is located on a bending magnet of the DORIS III storage ring whereas the second beamline, BW7A, is positioned at a multipole wiggler at the same storage ring. X31 is equipped with an energy stabilization device to ensure constant wavelength during longer data-collection periods. The in-house built crystallographic end-station is now equipped with a Mar345 imaging-plate scanner as a detector. The wiggler beamline BW7A features a novel sagitally focusing monochromator. The end-station used here has also been developed and built in-house. The beamline is currently operated with a Mar 165 CCD detector. In this paper the hardware and software developments of the last years will be summarized and the outlook for substantial upgrades will be given. The future plans include the design and construction of a third tunable beamline, designated X12, for protein crystallography. The development of automated beamlines for protein crystallography is of particular importance with respect to structural genomics initiatives. The analysis of the projects of the last years shows the wide range of anomalous scatterer used on the tunable beamlines thus demonstrating the need of a wide range of accessible energies and fast and reliable energy changes.

Changes in the iron coordination sphere of Fe(II) lipoxygenase-1 from soybeans upon binding of linoleate or oleate

Fe K-edge X-ray absorption spectra of the non-heme iron constituent of lipoxygenase-1 from soybeans were obtained. The spectrum of 2.5 mM Fe(II) lipoxygenase, mixed with 1.2 M linoleate in the absence of O2, was compared to the spectrum of the native (i.e. untreated) enzyme. In the lipoxygenase-linoleate complex, an edge shift to lower energy was observed. This indicated that the iron-ligand distances in this complex are slightly longer than those in the untreated enzyme species. The extended X-ray absorption fine structure spectrum of Fe(II) lipoxygenase, prepared by anaerobic reduction of 2.5 mM Fe(II) lipoxygenase with 1.2 M linoleate, was very similar to the spectrum of the anaerobic lipoxygenase-linoleate complex. We conclude that the conformational differences between the iron coordination spheres of native and cycled Fe(II) lipoxygenase must be ascribed to the presence of linoleate, and not to changes in the enzyme that occur only after one cycle of oxidation and reduction. Furthermore, spectra of 2.5 mM Fe(II) lipoxygenase mixed with 1.2 M oleate, either in the absence or in the presence of O2, were also identical to the spectrum of the Fe(II) lipoxygenase-linoleate complex. This finding is in agreement with our observation that oleate is a competitive inhibitor of the lipoxygenase reaction. Moreover, the similarity of the lipoxygenase-oleate complexes in the presence and absence of O2 excludes the possibility that O2 binding to the iron cofactor is induced upon binding of a fatty acid to lipoxygenase.

Cloning and expression of Saccharomyces cerevisiae copper-metallothionein gene in Escherichia coli and characterization of the recombinant protein

The gene sequences for intact and truncated forms of copper-binding metallothionein from Saccharomyces cerevisiae were cloned and overexpressed in Escherichia coli BL21(DE3)pLysE cells. In contrast to several other genes, the intact and truncated metallothionein genes are amplified in the polymerase chain reaction when Mg2+ is replaced by Co2+. The recombinant truncated protein binds copper in vivo and in vitro. A ratio of 8 Cu/12 cysteines was determined from atomic absorption, X-ray fluorescence and amino acid analysis. Extended X-ray absorption spectroscopy indicates that all Cu is in Cu(I) form and coordinated to three S atoms.

X-ray absorption spectroscopy of soybean lipoxygenase-1. Influence of lipid hydroperoxide activation and lyophilization on the structure of the non-heme iron active site

X-ray absorption spectra at the Fe K-edge of the non-heme iron site in Fe(II) as well as Fe(III) soybean lipoxygenase-1, in frozen solution or lyophilized, are presented; the latter spectra were obtained by incubation of the Fe(II) enzyme with its product hydroperoxide. An edge shift of about 2-3 eV to higher energy occurs upon oxidation of the Fe(II) enzyme to the Fe(III) species, corresponding to the valence change. The extended X-ray absorption fine structure shows clear differences in active-site structure as a result of this conversion. Curve-fitting on the new data of the Fe(II) enzyme, using the EXCURV88 program, leads to a coordination sphere that is in agreement with the active-site structure proposed earlier (6 +/- 1 N/O ligands at 0.205-0.209 nm with a maximum variance of 0.009 nm, including 4 +/- 1 imidazole ligands) [Navaratnam, S., Feiters, M. C., Al-Hakim, M., Allen, J. C., Veldink, G. A. and Vliegenthart, J. F. G. (1988) Biochim. Biophys. Acta 956, 70-76], while for the Fe(III) enzyme a shortening in ligand distances occurs (6 +/- 1 N/O ligands at 0.200-0.203 nm with maximum variance of 0.008 nm) and one imidazole is replaced by an oxygen ligand of unknown origin. Lyophilization does not lead to any apparent differences in the iron coordination of either species and gives a much better signal/noise ratio, allowing analysis of a larger range of data.

Evidence for polynuclear aggregates of ferric daunomycin. A Mössbauer, EPR, X-ray absorption spectroscopy and magnetic susceptibility study

The interaction of the antitumor agent daunomycin (DN) with ferric iron has been analysed by Mössbauer spectroscopy, EPR, extended X-ray absorption fine structure (EXAFS), and magnetic susceptibility measurements. In contrast to literature data, at millimolar iron and anthracycline concentrations no solitary Fe(DN)3 complexes are formed in appreciable amounts. The Mössbauer spectroscopic analysis revealed severe dependencies on temperature, on the preparation procedure, the time allowed for equilibration, and on the metal/ligand ratio. The Mössbauer spectra exhibit two components: a broad magnetic sextet and a quadrupole doublet at an Fe/DN molar ratio of 1:3 and exclusively a doublet at a molar ratio of 1:20, indicating an equilibrium of these two spectral components. The EPR spectra are dominated by a signal at g(eff) = 2. Double integration of the EPR signals enabled the determination of their spin density and a correlation between EPR and Mössbauer spectra. The Mössbauer sextet species is EPR invisible and corresponds to magnetically ordered polynuclear aggregates with high magnetic anisotropy. EXAFS and susceptibility measurements provide additional evidence for the formation of polynuclear aggregates of ferric daunomycin. The quadrupole doublet species in the Mössbauer spectra correlates with the g = 2 signal in EPR. This species is also related to a magnetically ordered system, exhibiting, however, superparamagnetic behavior due to less magnetic anisotropy. Since daunomycin forms dimers in aqueous solution at millimolar concentrations, we conclude that the cooperative phenomena observed in EPR and Mössbauer spectra are a consequence of its stacking effects.

Zn-ligation in inorganic deposits in the wall of the human aorta determined by X-ray absorption spectroscopy

X-ray absorption spectra were recorded at the K edge of Zn from inorganic deposits present in the human aortic wall. The interatomic distances and coordination numbers obtained indicate that Zn atoms probably occupy selected Ca positions in the lattice of the octacalcium phosphate crystals localized at the surface of the deposit.

Extended X-ray absorption fine structure (EXAFS) investigations of model compounds for zinc enzymes

A test of the ability of extended X-ray absorption fine structure (EXAFS) to determine structural information with specific reference to zinc sites in enzymes has been made. X-ray absorption spectra of 18 compounds of zinc have been measured and the nearest-neighbour scattering has been interpreted using a Fourier transform and an ab initio technique. Empirical Zn-N, Zn-O, Zn-S and Zn-Cl amplitude and phase functions have been extracted from Zn(C3H4N2)4(ClO4)2, ZnO, Zn(S2COC2H5)2 and [N(CH3)4]2[ZnCl4], respectively and tabulated as a function of the wavevector with respect to 9660.0 eV X-ray energy. These amplitude and phase functions were then tested with respect to the other 14 compounds. For a single species of atoms in the first coordination shell the interatomic distances can be established to +/- 0.5 pm (+/- 5 x 10(-3) A) whilst when mixed shells exist errors in distances are +/-4 pm (+/- 40 x 10(-3) A). Coordination numbers are given to +/- 16% for the single species case a and +/- 25% for the mixed coordination case. Using the theoretical amplitude and phase functions of McKale et al. [(1988) J. Am. Chem. Soc. 110, 3763-3768] the deduced distances are systematically too small by an average of 0.6 pm (6 x 10(-3) A). The errors in the coordination numbers are 18%.

Absolute energy calibration of X-ray radiation from synchrotron sources

A new apparatus and technique to determine the absolute energy of X-rays from a synchrotron source were used to establish the absolute energy of the zinc metal K absorption edge [9661.1(2) eV] and to measure systematic errors in the angular settings of a typical rotation table used for X-ray spectroscopy. These errors have a period of 1° associated with the worm gear of the rotation table and should provide a warning to other synchrotron radiation spectroscopists that systematic errors exist in experimental data. The technique relies on determining the orientation of a static silicon crystal with respect to the incoming beam by establishing degenerate reflections with differing Miller indices. Absolute energies can be determined for X-rays with energies greater than 6 keV. An analysis of the system shows that the technique is also useful for the accurate characterization of the monochromator resolution.

[Transitory oligoclonal paraproteinemia with virus infection and malignant lymphatic disease]

Oligoclonal paraproteinaemia occurred in two patients with malignant lymphocytic disease (highly malignant non-Hodgkin lymphoma, B-cell type of acute lymphocytic leukaemia), in one case during a cytomegalovirus infection and in the other during an infectious mononucleosis. At that time both patients were in complete remission. Paraproteinaemia in the first case disappeared within a year where the transformation from an initially four-banded paraproteinaemia (2 IgM-lambda and 2 IgG-lambda) into a three-banded paraproteinaemia (IgG-lambda) could be observed. In the second patient the concentration of the paraprotein decreased considerably. Because both patients were no longer under cytostatic treatment after manifestation of the paraproteinaemia, and were in complete remission during the whole of the observation period (4 years and 1 year), a direct relationship with the primary disease is unlikely. The transitory paraproteinaemia appears to be rather the result of an acquired defect of the immune system.