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The oxygen exchange kinetics of epitaxial Pr0.1Ce0.9O2−δelectrodes was modified by decoration with submonolayer amounts of different basic (SrO, CaO) and acidic (SnO2, TiO2) binary oxides. The oxygen exchange reaction (OER) rate and the total conductivity were measured by in situPLD impedance spectroscopy (i-PLD), which allows to directly track changes of electrochemical properties after each deposited pulse of surface decoration. The surface chemistry of the electrodes was investigated by near-ambient pressure XPS measurements (NAP-XPS) at elevated temperatures and by low-energy ion scattering (LEIS). While a significant alteration of the OER rate was observed after decoration with binary oxides, the pO2dependence of the surface exchange resistance and its activation energy were not affected, suggesting that surface decorations do not alter the fundamental OER mechanism. Furthermore, the total conductivity of the thin films does not change upon decoration, indicating that defect concentration changes are limited to the surface layer. This is confirmed by NAP-XPS measurements which find only minor changes of the Pr-oxidation state upon decoration. NAP-XPS was further employed to investigate changes of the surface potential step on decorated surfaces. From a mechanistic point of view, our results indicate a correlation between the surface potential and the altered oxygen exchange activity. Oxidic decorations induce a surface charge which depends on their acidity (acidic oxides lead to a negative surface charge), affecting surface defect concentrations, any existing surface potential step, potentially adsorption dynamics, and consequently also the OER kinetics.

Electrochemical impedance spectroscopy was used to investigate the chemical capacitance of La0.6Sr0.4CoO3−δ(LSC) thin-film electrodes under anodic polarization (i.e., in the electrolysis mode). For this purpose, electrodes with different microstructures were prepared via pulsed-laser deposition. Analysis of dense electrodes and electrodes with open porosity revealed decreasing chemical capacitances with increasing anodic overpotentials, as expected from defect chemical considerations. However, extremely high chemical capacitance peaks with values in the range of 104F/cm3at overpotentials of >140 mV were obtained after annealing for several hours in synthetic air and/or after applying high anodic bias voltages of >750 mV. From the results of several surface analysis techniques and transmission electron microscopy, it is concluded that closed pores develop upon both of these treatments: (i) During annealing, initially open pores get closed by SrSO4, which forms due to strontium segregation in measurement gases with minute traces of sulfur. (ii) The bias treatment causes mechanical failure and morphological changes including closed pores in the bulk of dense films. Under anodic polarization, high-pressure oxygen accumulates in those closed pores, and this causes the capacitance peak. Model calculations based on a real-gas equation allow us to properly predict the experimentally obtained capacitance increase. We demonstrate that analysis of the chemical capacitance of oxygen electrodes in solid oxide electrolysis cells can thus be used as a nondestructive observation tool to detect and quantify closed porosity with a lower detection limit between 10–4and 10–3.

The continuous extraction of the rhodium inventory in supported liquid-phase (SLP) catalytic materials utilized in the hydroformylation (HyFo) of 1-butene was investigated by supercritical carbon dioxide (scCO2). Optimization of extraction efficiency involved varying parameters such as temperature (90 and 120 °C), pressure (10, 20 and 30 MPa), and the addition of methanol as a polar co-feed to the extraction medium (0–20 vol%). The results underscored the critical role of methanol in facilitating extraction, as experiments employing pure scCO2yielded no rhodium recovery. Furthermore, extraction performance demonstrated sensitivity to temperature and pressure adjustments during the process. Notably, the use of 10 vol% methanol at 120 °C and 30 MPa achieved complete rhodium extraction from the grained SLP materials, which was identified as the optimum extraction condition. This study highlights the potential for scaling up in-situ rhodium extraction processes within HyFo production plants based on SLP catalysts, emphasizing significant implications for industrial applications.

The interface stability vs. Li represents a major challenge in the development of next-generation all-solid-state batteries (ASSB), which take advantage of the inherently safe ceramic electrolytes. Cubic Li7La3Zr2O12garnets represent the most promising electrolytes for this technology. The high interfacial impedance versus Li is, however, still a bot-tleneck towards future devices. Herein, we studied the electrochemical performance of Fe3+-stabilized Li7La3Zr2O12(LLZO:Fe) versus Li metal and found a very high total conductivity of 1.1 mS cm-1 at room temperature but a very high area specific resistance of ~1 kΩ cm2. After removing the Li metal electrode we observe a black surface coloration at the interface, which clearly indicates interfacial degradation. Raman- and nanosecond laser induced breakdown spectroscopy reveals, thereafter, the formation of a 130 µm thick tetragonal LLZO interlayer and a significant Li deficiency of about 1-2 formula units towards the interface. This shows that cubic LLZO:Fe is not stable versus Li metal by forming a thick tetragonal LLZO interlayer causing high interfacial impedance.

Laterally resolved chemical analysis (chemical imaging) has increasingly attracted attention in the Life Sciences during the past years. While some developments have provided improvements in lateral resolution and speed of analysis, there is a trend toward the combination of two or more analysis techniques, so-called multisensor imaging, for providing deeper information into the biochemical processes within one sample. In this work, a human malignant pleural mesothelioma sample from a patient treated with cisplatin as a cytostatic agent has been analyzed using laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) and matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS). While LA-ICPMS was able to provide quantitative information on the platinum distribution along with the distribution of other elemental analytes in the tissue sample, MALDI MS could reveal full information on lipid distributions, as both modes of polarity, negative and positive, were used for measurements. Tandem MS experiments verified the occurrence of distinct lipid classes. All imaging analyses were performed using a lateral resolution of 40 μm, providing information with excellent depth of details. By analyzing the very same tissue section, it was possible to perfectly correlate the obtained analyte distribution information in an evaluation approach comprising LA-ICPMS and MALDI MS data. Correlations between platinum, phosphorus, and lipid distributions were found by the use of advanced statistics. The present proof-of-principle study demonstrates the benefit of data combination for outcomes beyond one method imaging modality and highlights the value of advanced chemical imaging in the Life Sciences.

Perovskite-type La0.57Li0.29TiO3(LLTO) is a promising solid electrolyte material with high Li-ion conductivity. However, its experimental electrochemical stability window is not precisely known, and thus the compatibility with potential electrode materials is partly unclear. In this contribution, we present results from electrochemical and analytical experiments to elucidate the stability of LLTO when being polarized with Li-ion-blocking Pt electrodes. Above 2.5 V, a darkened color front starts moving from the cathode to the anode, leading to electrolyte degradation. While first-principles calculations predict the appearance of new phases as decomposition products, we find zones with modified defect chemical properties originating from the anode and cathode. The darkened zone forming at the cathode contains Ti3+polarons with high mobility, which leads to a mixed ion-electron conductivity, already for a very small Li excess concentration. Next to the anode a spatially very confined, weakly conductive Li depletion zone forms. The spatially confined but substantial Li depletion near the anode could be quantified by analytical laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). In contrast to first-principles calculations, no new phases were found near the anode, according to synchrotron-based grazing incidence XRD measurements.

Improvement of solid oxide fuel cells strongly relies on the development of cathode materials with high catalytic activity for the oxygen reduction reaction. Excellent activity was found for perovskite-type oxides such as La1−xSrxCoO3−δ(LSC), but performance degradation, probably caused by surface composition changes, hinders exploitation of the full potential of LSC. This study reveals that the potentially very high activity of the LSC surface can be traced back to few very active sites. Already tiny amounts of SrO, for example, 4% of a monolayer, deposited on an LSC surface, lead to severe deactivation. Co, on the other hand, causes (re-)activation, suggesting that active sites are strongly related to Co being present at the surface. These insights could be gained by a novel method to measure changes of the electrochemical performance of thin film electrodes in situ, while modifying their surface: impedance spectroscopy measurements during deposition of well-defined fractions of monolayers of Sr-, Co- and La-oxides by single laser pulses in a pulsed laser deposition chamber.

Modern chemical imaging techniques provide spatially resolved information on the molecular and elemental composition of samples with both high spatial and spectral resolution. Over the past few decades these techniques, in particular, Fourier transform infrared (FTIR) spectroscopy and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) have been successfully applied in histopathological research. This work demonstrates that the multivariate analysis of combined FTIR and LA-ICP-MS microscopy hyperspectral images can bring additional knowledge to biomedical research. The concept of such analysis was demonstrated while investigating two different tumor samples subjected to anticancer therapy. Combined analysis has revealed a correlation between the lateral distribution of analytes and sample properties within the different techniques. Correlations between alterations in the average protein secondary structure and platinum distribution were found, as well as between changes in the cell nuclear morphology and a reduction of physiologically relevant trace elements. The results of combined analysis suggested different degrees of tumor viability. Univariate analysis and k-means clustering successfully discriminated dead tumor regions and supported the results of combined analysis.

An analytical procedure for straight-forward quantification of rare earth elements (REEs) in tea was developed. The method consists of three steps: first, dry tea powder is converted into an aqueous sample solution using a microwave-assisted digestion procedure. Then, the REEs are retained on newly designed sorbent particles and are thus effectively extracted from the sample digest. Then, the REE-loaded sorbent material is introduced into the furnace of an electro-thermal vaporization (ETV) unit. There, the core of the particles is pyrolyzed and removed in a first temperature step. Then, the REE analytes are swiftly evaporated at high temperatures, and subsequently analyzed by ICP-OES. The advantages of the method proposed here are as follows: extraction of REEs is accomplished via“dispersed particle extraction”; this avoids typical shortcomings of conventional solid-phase extraction. The analysis viaETV allows separation of the sorbent particles from the analytes in time. Thus, detrimental effects of plasma-loading are circumvented. The method was shown to provide satisfactory detection limits of typically 50 ng g−1in the dry tea samples (3 s criterion). The method was validated by means of spike recovery experiments, and applied to the analysis of ten different tea samples from China, Japan and India, as sold in European markets.

Symmetric cells with porous La0.6Sr0.4Co0.2Fe0.8O3-d (LSCF) electrodes on Gd0.1Ce0.9O1.95 (GDC) electrolytes were aged at 800degC for 800 hours in ambient air. Electrochemical impedance spectroscopy (EIS) measurements performed periodically at 700degC showed a continuous increase of the polarization resistance from 0.15 to 0.34 O*cm2. Three-dimensional (3D) tomographic analysis using focused ion beam-scanning electron microscopy (FIB-SEM) showed negligible changes due to the ageing, suggesting that the observed resistance increase was not caused by electrode morphological evolution. However, an increased amount, by a factor of 3, of a water-soluble Sr rich surface phase on the aged LSCF electrode was detected by an etching procedure coupled with inductively coupled plasma-optical emission spectrometry (ICP-OES). The electrochemical analysis in combination with the microstructural parameters determined by FIB-SEM was used to examine the effect of Sr segregation on the rate of oxygen surface exchange, based on the Adler-Lane-Steele (ALS) model.

Immunosuppressive signaling via the adenosine A2Areceptor (A2AR) is an important pathway to control inflammation. In immune cells, expression levels of A2ARs influence responsiveness to inflammatory stimuli. However, mechanisms driving expressional changes of A2ARs are still largely elusive. In the current study, we have investigated the impact of microRNAs (miRNAs) on A2AR expression in human polymorphonuclear leukocytes (PMNs) and T cells. Bioinformatic analyses and reporter gene assays revealed that A2AR expression is controlled by miRNA-214, miRNA-15, and miRNA-16. We detected all three miRNAs in both human PMNs and T cells. However, in PMNs, up to 10-fold higher levels of miRNA-16 and miRNA-214 were detected as compared with T cells. Upon in vitrostimulation, no significant expressional changes occurred. Expression levels of all three miRNAs strongly differed between individuals. A2AR expression also exhibited significant differences between PMNs and T cells: In PMNs, more than a 60-fold increase was seen upon LPS stimulation, whereas in T cells only a 2-fold increase was observed upon anti-CD3CD28 activation. The extent of A2AR upregulation in PMNs strongly differed between individuals (from less than 10-fold to more than 100-fold). In PMNs, the increase in A2AR mRNA expression upon stimulation was inversely correlated with the expression levels of miRNA-214, miRNA-15, and miRNA-16 (R= −0.87, P< 0.0001); no correlation was found in human T cells. These results indicate that individual miRNA profiles gain important influence on A2AR expression regulation in PMNs upon stimulation. Determination of miRNA expression levels may help to identify patients with an increased risk for severe inflammation.

Pulsed laser deposited La0.6Sr0.4CoO3[?]d (LSC) thin film electrodes on yttria stabilized zirconia (YSZ) single crystals were investigated by impedance spectroscopy, time of flight secondary ion mass spectrometry (ToF-SIMS) and inductively coupled plasma optical emission spectrometry (ICP-OES). Effects caused by different film deposition temperatures, thermal annealing and chemical etching were studied. Correlations between changes in electrode polarization resistance of oxygen reduction and surface composition were found. At high deposition temperatures and after thermal annealing an inhomogeneous cation distribution was detected in the surface-near region, most manifest in a significant Sr enrichment at the surface. An activating effect of chemical etching of LSC is described, which can lower the polarization resistance by orders of magnitude. Chemistry behind this activation and thermal degradation was analyzed by ToF-SIMS and ICP-OES measurements of in-situ etched LSC films. The latter allow quantitative depth resolved compositional analysis with nominally sub nm resolution. High resolution scanning electron microscopy images illustrate the accompanying changes in surface morphology. All measurements suggest that stoichiometric LSC surfaces intrinsically exhibit very high activity towards oxygen reduction.

La0.6Sr0.4CoO3-d (LSC) thin film electrodes on yttria stabilized zirconia (YSZ) were investigated by impedance spectroscopy, inductively coupled plasma optical emission spectrometry (ICP-OES) and time of flight secondary ion mass spectrometry (ToF-SIMS). Effects caused by different film deposition temperatures, thermal annealing and chemical etching were studied. Correlations between changes in electrode polarization resistance of oxygen reduction and surface composition were found. The surface cation composition was analyzed by ToF-SIMS and ICP-OES measurements of in situ etched LSC films allowing depth resolved compositional analysis with nominally sub nm resolution. High resolution scanning electron microscopy images illustrate changes in surface morphology.

A method for accurate on-line ultra-trace analysis of palladium by inductively coupled plasma mass spectrometry has been developed. After separation of interfering cations by cation exchange chromatography, palladium was selectively adsorbed on to a C18 micro-column on-line which had been reversibly loaded with the complexing agent N,N-diethyl-N′-benzoylthiourea (DEBT). The palladium complex formed was eluted with methanol and introduced into an ICP-SFMS via microconcentric nebulization with membrane desolvation. Quantification of palladium was carried out by isotope dilution analysis. The results obtained via the isotope ratios of 105Pd/108Pd and 106Pd/108Pd agreed within their measurement uncertainty. For solid samples (total intake 100 mg, final sample volume of 10 mL after closed vessel microwave digestion) the limit of detection was 0.24 ng g−1 palladium (2 mL of digested sample). The necessity of combining matrix separation and pre-concentration for elimination of spectral interferences was demonstrated using soil samples. The method was validated by analysis of the certified reference material BCR-723 (road dust).

A method for on-line pre-concentration of platinum with subsequent determination by electro-thermal atomic absorption spectrometry ETAAS has been developed. After a preliminary treatment of the sample solution with tinii-chloride the formed anionic Pt–Sn complexes were on-line adsorbed on a C18 micro column which has been reversibly loaded with the chelating agent N,N-diethyl-N′-benzoylthiourea. The formed platinum complex was eluted with ethanol and directly introduced into the graphite furnace. Using a sample volume of 1.57 mL the limit of detection was calculated to be 0.1 μg L−1. The reproducibility of the method given as the relative standard deviation was 5.5 at a concentration level of 0.5 μg L−1Pt n 10. The accuracy of the developed method has been demonstrated by the analysis of the certified reference material BCR-723 road dust. The new method has been applied to the analysis of platinum in aerosol samples collected in a highway-tunnel in Vienna, Austria.

A method for on-line pre-concentration of platinum with subsequent determination by electro-thermal atomic absorption spectrometry (ETAAS) has been developed. After a preliminary treatment of the sample solution with tin(ii)-chloride the formed anionic Pt–Sn complexes were on-line adsorbed on a C18 micro column which has been reversibly loaded with the chelating agent N,N-diethyl-N'-benzoylthiourea. The formed platinum complex was eluted with ethanol and directly introduced into the graphite furnace. Using a sample volume of 1.57 mL the limit of detection was calculated to be 0.1 μg L−1. The reproducibility of the method given as the relative standard deviation was 5.5% at a concentration level of 0.5 μg L−1 Pt (n = 10). The accuracy of the developed method has been demonstrated by the analysis of the certified reference material BCR-723 (road dust). The new method has been applied to the analysis of platinum in aerosol samples collected in a highway-tunnel in Vienna, Austria.

Various tetrahydrofuran2ylmethylamines have been prepared in good yields by an efficient onestep synthesis utilizing the reaction of tetrahydrofurfurylchloride with different secondary cyclic amines without any catalyst. The compounds were tested for their in vitroaffinity for the α42β23and α7 nicotinic acetylcholine receptor nAChR subtypes. Pyrrolidine, piperidine and azepane containing analogs 1a, 1b, 1c showed Kivalues in the lower micromolar range for these neuronal nAChR subtypes in rat brain.

Pt, Pd and Rh concentration levels related to particle size distribution were measured in Viennese aerosol. The urban aerosol was studied over a period of 1 month during summer 2002 in a heavy traffic area. A 6-stage cascade impactor collected classified particles with aerodynamic equivalent diameter (aed) &lt;10 µm. Total suspended particulate matter (aed &lt;30 µm) was assessed by filtering air (open face sampling head). The analysis of Pt, Pd and Rh in aerosol samples required a different strategy for each element to obtain accurate results and maximum sensitivity. Sample preparation was carried out by microwave-assisted acid digestion. For the determination of Pd an anion-exchange procedure was implemented. The digested samples were measured by ICP-SFMS in combination with ultrasonic nebulization and membrane desolvation, utilizing the high-resolution capabilities of this instrument for the determination of Rh. Pt and Pd were quantified by isotope dilution (IDMS), Rh by external calibration. Excellent detection limits of 0.07, 0.06 and 0.05 pg m−3 (impactor substrates) and 0.18, 0.22, 0.14 pg m−3 (open face sampling head substrates) for Pd, Pt and Rh, respectively, could be achieved. Since platinum group elements (PGE) are emitted from car catalysts as a result of mechanical processes, Pt, Pd and Rh were mainly found in the coarse fraction of urban aerosol. Summing up the concentrations assessed for the impactor stages (aed &lt;10 µm) revealed a weekly average of 4.3 ± 1.7, 2.6 ± 0.6 and 0.4 ± 0.1 pg m−3 for Pt, Pd and Rh respectively. Concentration levels of samples collected with the open face sampling head (aed &lt;30 µm) over the period of one week were significantly higher with average values of 38.1 ± 6.3, 14.4 ± 3.1 and 6.6 ± 2.4 pg m−3. Moreover, the presence of a collective of small particles containing the three investigated PGE was shown. Investigation of the impactor samples revealed an analogue size distribution for Pt, Rh and Pd with a maximum at 1–2.15 µm aed. These particles are toxicological relevant, as they penetrate deeply in human lungs (particles of 0.1–2.5 µm aed are deposited in the lung alveoli).

A flow injection procedure with ETAAS detection for the on-line matrix separation and preconcentration of palladium in environmental samples such as airborne particulate matter and road dust was developed. The selective enrichment of palladium was performed on a C18 micro column which has been reversibly loaded with the complexing agent N,N-diethyl-N'-benzoylthiourea. The formed palladium complex was eluted with ethanol and directly introduced into the graphite furnace. With the use of a 1.57 ml sample loop a limit of detection of 23 ng l−1 and a limit of quantification of 39 ng l−1 were obtained for the determination of palladium, with a relative standard deviation being not more than 3.9%. The method including the developed digestion procedure has been evaluated using the certified reference material BCR-723 (road dust). Finally the procedure was applied for the analysis of aerosol samples from the urban site Vienna.

A new method was developed for the simultaneous determination of polar organic compounds from liquid samples (atmospheric hydrometeors) as well as for aerosol samples. The analysis of aerosol samples includes a new extraction method using diethylether, methanol and organic free water to obtain a liquid sample solution. The sample-separation into two classes of organic compounds with different polarity was performed using solid phase extraction (SPE). The adsorbed fraction contains weakly polar compounds like monocarboxylic acids (C8 - C18), alcohols (C8 - C18), phthalates, aliphatic and aromatic aldehydes. The solution passing the SPE-tube contains the not adsorbed strong polar organic compounds like dicarboxylic acids (C2 - C9) and related compounds. After a sample pretreatment of the two fractions, including esterification of the acids and extraction with cyclohexane, the samples were analyzed with GC-MS. Recoveries for the determined compounds ranged from 60 - 100%, the experiments have shown that substances with longer carbon chains exhibit decreased recoveries. The reproducibility given as the relative standard deviation varies from 5 - 15%. The absolute amount of an individual compound which is necessary for detection is about 10 to 50 ng. For quantification the absolute amounts varies in a range of 25 to 150 ng. The new method is applied for the analysis of aerosol and cloud water samples from a continental background site in Central Europe (Sonnblick Observatory).

53 children diagnosed as having minimal brain dysfunction by the criteria of Clements had X-rays of their left wrist and hand for the determination of bone age. All X-rays were read independently by three physicians skilled in radiology. The films were read blind, that is, sex and case numbers but not age were available. The degree of inter-rater reliability was very high (r= 0.87). Bone age for the minimal brain dysfunction group was significantly retarded (p< 0.01) compared with the standard group's norms. Bone ages of more than 2 SDbelow the mean occurred in 10 children, while only one child showed a bone age of more than 2 SDabove the mean. Two-thirds of the children in the minimal brain dysfunction group fell below the mean of the standard norms. No correlation was found between bone age and thyroid level. These findings suggest that children diagnosed as having minimal brain dysfunction may be physiologically retarded in their bone age, although marked individual variations remain. The concept of physiological immaturity should be considered by professionals in the education and social planning for the child with minimal brain dysfunction.

This study assessed the potential trophic significance of zooplankton in a stream ecosystem that has distinct riffle and pool geomorphology. Quantitative samples were taken in the first five orders of an alluvial gravel bed stream, the Illinois River, Arkansas, USA. A manipulative experiment was performed in a third order reach to determine if plankton resources were utilized by net-spinning caddisfly larvae, Cheumatopsyche. An abundant, diverse zooplankton community comparable to that of local reservoirs was present in the headwaters, especially where flow through pools was < 0.02 m/sec. an inverse relationship between plankton density and flow rate was observed among pools where flow was > 0.05 m/sec. Significant (p < 0.05) quantities of plankters were produced within pools and then removed as the stream flowed across second and third order riffles. the instream experiment revealed that substrate colonized by Cheumatopsyche removed significantly (p < 0.05) more of the plankton at midnight than substrate alone, but not at midday. Both treatments removed considerable plankton. Fewer zooplankton were collected from downstream sites (orders three through five). This was partially attributed to increased predation by planktivorous fish. Zooplankton apparently increase the food quality of seston in streams, especially those which have areas of sufficiently slow flow rates.

Isothermal P, x data at 413.65 K, excess enthalpies at 323.15, 363.15, and 413.15 K, and azeotropic data are presented for binary systems containing benzaldehyde, benzene, toluene, and phenol. Reliable information about the real behavior of systems including these components is very important for various chemical processes, e.g., for the production of phenol by toluene oxidation. Furthermore, these data will be used for the revision, extension, and further development of the group contribution method modified UNIFAC (Dortmund). The vapor−liquid equilibrium (VLE) data of four systems were measured using a static apparatus. In the case of the system benzaldehyde + phenol, azeotropic data were determined by distillation. For all systems, the corresponding experimental excess enthalpy (H^E) data were determined with the help of an isothermal flow calorimeter. For the simultaneous description of VLE and H^E data, the NRTL model was used.

Adrenocortical function was studied in 25 children with hypoglycemia, separated into two groups, depending on whether their height was above or below the third percentile. Plasma 17-hydroxycorticosteroid (17-OHCS) concentrations were not significantly different in the two groups, and were higher than normal in both. In both groups, the urinary 17-OHCS values were quite low considering the high plasma concentrations, but in neither group were they significantly lower than normal. Adrenal responsiveness to adrenocorticotropic hormone (ACTH) was normal as judged by the responses of both plasma and urinary 17-OHCS. In contrast, the control urinary 17-ketosteroid (17-KS) levels differed significantly from each other in the two groups, those in the group with severe growth retardation being significantly lower than normal and those in the other group being in the low normal range.

FEW STUDIES concerning adrenocortical function in children with cystic fibrosis of the pancreas have been reported. In two patients, di Sant'Agnese et al1 noted an increased excretion of urinary 17-ketosteroids (17-KS) in response to corticotropin, a normal reduction of urinary electrolyte excretion during salt restriction, and little response of sweat electrolytes to desoxycorticosterone administration. Siegenthaler et al2 have demonstrated normally elevated urinary aldosterone levels, but persistently pathological sweat electrolyte concentrations during salt restriction in one child, and normal control urinary aldosterone levels in four children with this disease. Recently, Lietman and di Sant'Agnese3 reported studies on ten patients with cystic fibrosis of the pancreas. These studies yielded the following observations: (1) normal urinary aldosterone levels during control and salt-restriction periods in eight patients, (2) the lack of a decrease in sweat electrolyte concentrations during salt restriction in all patients, and (3) normal oral glucose response tests, urinary

•Intense human activity between ~1300 cal BCE and ~500 cal BCE.•High Sn concentrations imply bronze casting between ~1210 cal BCE ~540 cal BCE.•Early periods of moderate human impact around ~2350 cal BCE and ~1800 cal BCE.•Distinct isotopic signature of peat underlines the local origin of signals.

STRUCTURALLY, glycogen is a complex branched molecule composed of glucosyl units.1 The branching points are formed by 1,6-bonds, while all other glucosyl units are attached by 1,4-bonds. Liver phosphorylase, an enzyme activated by glucagon, splits the 1,4-bonds, releasing glucose-1-phosphate. This, in turn, is metabolized to glucose-6-phosphate and then to glucose. The debrancher enzyme (amylo-1,6-glucosidase) splits the 1,6-bonds; if this enzyme is deficient, the degradation of glycogen will cease at the branching points. Theoretically, a 14-hour fast in a patient with debrancher enzyme deficiency, type 3 glycogen storage disease by Cori's classification,1 would be associated with the degradation of the outer branches of glycogen by liver phosphorylase to the points of 1,6-bonds; glucagon administration to such a patient would not result in a hyperglycemic response. If, however, such a patient were fasted for 14 hours and then fed a regular meal, outer branches might be resynthesized sufficiently so

DURING the past 18 months we have seen three patients who developed hypoglycemia in association with salicylate ingestion. The purpose of this paper is to emphasize the importance of considering and recognizing this association. It was possible to perform extensive studies on only one of these patients (case 1); this case will be presented in some detail and the other two only briefly. REPORT OF CASES Case 1.—This 22-month-old white male was the product of a term pregnancy which was complicated by toxemia and abruptio placenta. His birth weight and length were 1.5 kg (31/2 lb) and 41 cm (16 inches), respectively. The first 48 hours of life were complicated by respiratory distress, recurrent apneic spells, and generalized seizures. A blood sugar value at this time was 4 mg%. The hypoglycemia was adequately controlled with hydrocortisone therapy. At 2 weeks of age, the patient developed unexplained jaundice, associated with hepatosplenomegaly,

SALICYLATES and acetaminophen (Tempra), structurally related compounds, are prescribed commonly as antipyretic and analgesic agents for children. The undesirable effects of salicylates as manifested by either acute or chronic salicylism are well described.1 The currently recognized side effects associated with acute acetaminophen toxicity include methemoglobinemia, anemia, hepatic cell injury, and possibly allergic reactions.2,3 Recently, certain patients have been described who developed hypoglycemia while receiving salicylates.4,5 The purpose of this paper is to report a patient who developed hypoglycemia in association with acetaminophen administration. REPORT OF A CASE The clinical course of this patient through 22 months of age has been reported previously.4 His past history included the following features: delivery at term following a pregnancy complicated by toxemia and abruptio placenta; respiratory distress, apnea, and seizures associated with hypoglycemia occurring during the first 48 hours of life; control of hypoglycemia with hydrocortisone therapy; seizures occurring at