XUV frequency comb production with an astigmatism-compensated enhancement cavity.

We have developed an extreme ultraviolet (XUV) frequency comb for performing ultra-high precision spectroscopy on the many XUV transitions found in highly charged ions (HCI). Femtosecond pulses from a 100 MHz phase-stabilized near-infrared frequency comb are amplified and then fed into a femtosecond enhancement cavity (fsEC) inside an ultra-high vacuum chamber. The low-dispersion fsEC coherently superposes several hundred incident pulses and, with a single cylindrical optical element, fully compensates astigmatism at the w0 = 15 µm waist cavity focus. With a gas jet installed there, intensities reaching ∼ 1014 W/cm2 generate coherent high harmonics with a comb spectrum at 100 MHz rate. We couple out of the fsEC harmonics from the 7th up to the 35th (42 eV; 30 nm) to be used in upcoming experiments on HCI frequency metrology.

Piagetian Tasks and Psychometric Intelligence: Different or Similar Constructs?

Research on cognitive ability is done in different paradigms. In the Piagetian paradigm, cognitive ability focuses on cognitive development along qualitative stages. Interactive real scenarios, "Piagetian tasks", are constructed for measurement. According to age, tasks differing in complexity are applied in individual measurements. In the psychometric paradigm, the investigation of cognitive ability focuses on individual differences. Intelligence is seen as a quantitative construct with gradual differences between persons and ages. Paper-and-pencil tests with items differing in difficulty are used for IQ measurement of single persons or school classes. However, do those tasks measure two distinct cognitive abilities? Solving tasks in both approaches requires basic (speed, working memory) and complex cognitive abilities (reasoning, understanding). Regarding empirical relationships, we used three Austrian samples (in kindergarten four to six years old N = 40, in primary school six to eight years old N = 40, and nine to ten years old N = 41). They were tested with psychometric tests (Raven CPM or SPM) and Piagetian tasks. In addition, mental speed (ZVT) was measured in the two school samples. The average observed correlation between IQ and Piagetian tasks was r = .51. In factor analyses, the tests loaded on a common factor of general intelligence. Further analyses revealed that mental speed is correlated more strongly with psychometric (r = .50) than with Piagetian tasks (r = .39), while Piagetian tasks are more related to parental education indicators (speed: r = .11, Raven: r = .20, Piaget: r = .25).

Does Blindness Boost Working Memory? A Natural Experiment and Cross-Cultural Study.

Intelligence requires sufficient working-memory capacity. Traditionally, working memory was seen as a process and as a prerequisite for fluid intelligence. Working memory was assumed to be determined by maturation and health. There is a gap in the literature: It is still not fully understood to which extent and how working memory can be influenced. So this study tested how visual impairment and the extent of visual impairment are related to working memory capacity. In our study we compared N = 249 children (6-16 years) with and without visual impairment (blind, visually impaired, and sighted) in two countries (South Africa and Austria) at different development levels on their working-memory capacity and verbal comprehension. Using the WISC-IV, blind and visually impaired children showed higher working-memory capacity than sighted children (r = + 0.35, 14, and 3 IQ points, respectively). On the other hand, visually impaired children showed a weakness in verbal comprehension (r = -0.39, on average 13 IQ points lower). The pattern remained robust when SES and race-ethnicity were controlled. Our natural (quasi-)experiment shows a pattern, which is unlikely to be genetic, and so supports the view that working memory and intelligence scores can be modified.

100 MHz frequency comb for low-intensity multi-photon studies: intra-cavity velocity-map imaging of xenon.

We raise the power from a commercial 10 W frequency comb inside an enhancement cavity and perform multi-photon ionization of gas-phase atoms at 100 MHz for the first time, to the best of our knowledge. An intra-cavity velocity-map-imaging setup collects electron-energy spectra of xenon at rates several orders of magnitude higher than those of conventional laser systems. Consequently, we can use much lower intensities ${\sim}{{10}^{12}} \;{\rm W}/{{\rm cm}^2} $∼1012W/cm2 without increasing acquisition times above just a few seconds. The high rate and coherence of the stabilized femtosecond pulses are known to be transferred to the actively stabilized cavity and will allow studying purely perturbative multi-photon effects, paving the road towards a new field of precision tests in nonlinear physics.

An audit of the use of platelet transfusions at Universitas Academic Hospital, Bloemfontein, South Africa.

An audit was performed at a tertiary hospital in Bloemfontein, South Africa, to establish whether clinicians adhered to local platelet transfusion guidelines. The audit showed poor compliance with local guidelines, with 34% of platelet transfusions not aligned with guidelines and 29.9% of transfusions administered to patients with platelet counts of ≥ 150 × 10(9)/L. When compared to medical disciplines, surgical disciplines tended significantly more to transfuse platelets inappropriately (17.1% and 53.7%, respectively; p < 0.0001). Documentation was poor and in 48.4% of orders for platelets, the indication for the platelet transfusion was not clearly stated. Considerable cost could be avoided with improved adherence to guidelines. This study emphasises the need for improving education in transfusion medicine amongst medical doctors. It is hoped that the information gleaned from this study would assist in the design of educational programmes in transfusion medicine as we attempt to close the existing gaps in knowledge and skills in the field, while ensuring that blood is transfused in a cost-effective and appropriate manner.

Incidences and predictors of difficult laryngoscopy in adult patients undergoing general anesthesia : a single-center analysis of 102,305 cases.

BACKGROUND: Hypoxemia caused by difficulties in airway management presents a major cause for perioperative morbidity and mortality. The ability to predict difficult laryngoscopy more accurately would enable anesthesiologists to take specific precautions to reduce airway risks and prevent patient-threatening events. METHODS: Over a 6-year period of time, all anesthesia records with a documented direct laryngoscopic view were retrieved from the electronic data management system and statistically processed. The Cormack-Lehane four-point scale of grading laryngoscopy was used to assess visibility of the vocal cords. RESULTS: Of 102,306 cases, the overall rate of difficult laryngoscopy was 4.9 %. Male gender (6.5 %), Mallampati score III and IV (17.3 %), obesity with a BMI ≥35 kg/m(2) (6.1 %), as well as physical status ASA III or IV (6.2 %), were identified as risk factors for difficult laryngoscopy. Patients undergoing surgery in the departments of oromaxillofacial (8.9 %), ear nose throat surgery (ENT) (7.4 %), and cardiac surgery (7.0 %) showed the highest rates of difficult laryngoscopy. CONCLUSIONS: The results indicate that the risk for difficult airway situations might substantially differ between surgical patient groups. In hospitals with departmental structures and spatially separated operating rooms, the deduction might be increased awareness and particular structural preparation for difficult airway situations in the respective subspecialties.

[Anesthesiological time requirements and reasons for delayed processes in MRI examinations of children undergoing sedation or general anesthesia]. / Magnetresonanztomografie bei Kindern in Sedierung--anästhesiologisches Prozedere, Zeitbedarf und Determinanten verzögerter Prozessabläufe.

PURPOSE: MRI examinations in children under sedation or general anesthesia are a multidisciplinary challenge for pediatric, radiology and anesthesiology departments. This article presents findings about patient population, anesthesiology procedures and process times in pediatric MRI procedures under sedation or general anesthesia. The analysis is focused on the potential to optimize process times. MATERIALS AND METHODS: Retrospectively over a 5-year period, data from diagnostic radiology procedures in children requiring sedation or general anesthesia were retrieved from anesthesia records and analyzed statistically. RESULTS: The median anesthesia time in patients without an airway device was 6 min. In patients with a laryngeal mask (19 min) and in patients receiving endotracheal intubation (20 min), the anesthesia time was significantly longer (p < 0.001). The need for airway management in the age groups was 67 % for neonates, 25 % for infants, 8 % for toddlers and 7 % for school children. Improved clinical pathways could potentially save additional time up to 69 hours in our period of investigation. CONCLUSION: In relation to older children, toddlers, infants and neonates had the longest process times in diagnostic radiology procedures, caused by the need to secure the airway. Improved pre-MRI processes have an enormous potential to generate additional examination time.

[Measurement of retinal thickness with the Heidelberg retina tomograph for patients with macular edema and healthy individuals]. / Netzhautdickenmessung mit dem Heidelberg Retina Tomograph bei Patienten mit Makulaödem und bei Gesunden.

BACKGROUND: This study was carried out to test the reliability of a defined cut-off value for retinal thickness with estimation of the sensitivity, specificity and formation of an edema index in comparison to retinal thickness. MATERIALS AND METHODS: This was a single center prospective clinical non-blinded study of 100 eyes, including 22 eyes with central vein or branch vein occlusions, 20 eyes with diabetic macular edema, 6 eyes with postoperative macular edema, 2 eyes with uveitis and 50 healthy eyes. Detection of macular edema was carried out by third generation optical coherence tomography. Using the latest version of the Heidelberg retina tomograph (HRT 3) series of five images were produced and evaluated. The 9-zone circle of the HRT was used as the analysis contour. RESULTS: The reliability of measuring retinal thickness with the HRT in the subjects showed an intraclass correlation between 0.248 and 0.740 and patients with macular edema showed values between 0.515 and 0.949. The reliability of the edema index with the HRT in the subjects showed an intraclass correlation between 0.461 and 0.826 and patients with macular edema showed values between 0.383 and 0.826. The calculated cut-off values were between 285 µm and 360 µm. The corresponding sensitivity values were between 74.7% and 95.9% with a corresponding specificity of 74.7-90.2%. There was also a highly significant correlation between the edema index and retinal thickness (p < 0.001). CONCLUSIONS: The retina module of the latest generation HRT is capable of reproducible measurement of the retinal thickness in micrometers. The defined cut-off values correspond to expectations and can be used in this form in the clinical practice.

[Diode laser. Ex vivo studies on vaporization and coagulation characteristics]. / Der Diodenlaser. Ex-vivo-Untersuchungen zu den Vaporisations- und Koagulationseigenschaften.

INTRODUCTION AND OBJECTIVES: Laser therapy of symptomatic benign prostatic hyperplasia (BPH) remains a challenge for most urologic surgeons. The main goal of laser surgery is to achieve a marked volume reduction and to decrease bladder outlet obstruction and lower urinary tract symptoms with minimal morbidity. Laser therapy encompasses a variety of techniques using different laser wavelengths, application systems, and surgical techniques to achieve contrasting tissue effects. In an in vitro animal model we compared the vaporization and coagulation effects of the potassium-titanyl-phosphate (KTP) laser, holmium:yttrium-aluminum-garnet (Ho:YAG) laser, and diode laser (980 nm). MATERIAL AND METHODS: In an in vitro model using isolated perfused porcine kidneys we investigated the vaporization, the coagulation effect, and the bleeding rate of the KTP, Ho:YAG, and diode lasers on five porcine kidneys each. The application of each laser type was standardized. The area of laser application was 1 cm x 1 cm. The KTP group received an application with 80 W, the Ho:YAG group an application with 10-30 W, and the diode group an application with 30, 60, and 100 W. Hemostasis was measured semiquantitatively. Ablation and coagulation were investigated macro- and microscopically. RESULTS: Concerning the ablation capacity, the diode laser is most effective (more than fivefold) compared to the KTP and Ho:YAG lasers but demonstrated a rather large coagulation zone of up to tenfold in comparison to the KTP and Ho:YAG lasers. Semiquantitatively, in terms of bleeding rate, all lasers were equivalent in this ex vivo model. CONCLUSIONS: Our very early and limited experience indicates that KTP (80 W) and Ho:YAG (30 W) laser application are equivalent in terms of tissue ablation capacity and coagulation in an experimental setting. The diode laser at 980 nm is superior in terms of ablation capacity but has a large coagulation zone. Concerning the bleeding rate all tested lasers are equivalent in this ex vivo model.

[VC and DCE in groundwater and drainage channel water]. / VC und CIS im Grund- und Oberflächenwasser -- Kontamination von Bodenluft und Grabensedimenten. Risikoabschätzungen für die Nahrungskette, Untersuchungen von Lebensmittelproben.

In an area used merely for gardening in a downland moor, which is partly transformed to an industrial estate, accidentally a contamination of a drainage channel with VOC's - predominantly chloroethylene (vinyl chloride [VC]) and 1.2-cis-dichloroethylene (DCE) - was found. The ascending ground water leaks into the drainage channels. The dissolved harmful substances (water solubility of VC is 1.6 g/l) can reach the radix range of plants and fruit bosks and can theoretically be incorporated with the water influx. Additionally the water from the drainage channels can be used to water the crops. Six gardens and a housing were involved. In the groundwater of the mainly concerned region max. 5,000 microg/l VOC's (quite predominantly VC and DCE) was measured from 147 samples. In the drainage channel water max. 2,500 microg/l was measured from 52 samples (limit value according to the drinking water ordinance is 10 microg/l). In the sediment of the channel with approximately 60,000 microg/kg VOC was found in dry matter (6 samples). We describe, how the consumer protection dept. dealt with this unexpected situation and what measures were taken. The impact on human health by the contaminated ground and channel water or by means of contaminated plants are determined for tree fruits, potatoes, bulbs and carrots. The soil air was contaminated, but in buildings no harmful compounds were detectioned.

Isolation, identification and changes in the composition of lactic acid bacteria during the malting of two different barley cultivars.

Malt has a complex microbial population, which changes as the malting process commences. Little is known about the proliferation of lactic acid bacteria (LAB) in each of the malting phases. In this study, we determined the number of LAB present in the different phases of malting with Clipper and Prisma barley cultivars. The strains were identified to species level by using numerical analysis of total soluble cell protein patterns, RAPD-PCR banding patterns and 16S rRNA sequencing. The number of viable LAB in the barley before steep was higher in Prisma than Clipper (7.6 x 10(4) and 1.2 x 10(3) cfu/g, respectively). Despite this, the number of viable cells recorded in the first steep water was slightly higher for Clipper (9.0 x 10(5) cfu/g) than Prisma (5.5 x 10(5) cfu/g). More or less, the same cell numbers were recorded for the two barley cultivars after the first and second dry stands. Both cultivars displayed more or less the same cell numbers (3.7 x 10(7) for Clipper and 3.2 x 10(7) cfu/g for Prisma) after the third day of germination. However, a higher number of LAB were detected in the kilned Prisma malt (6.9 x 10(4) cfu/g) than the Clipper malt (1.5 x 10(4) cfu/g). Leuconostoc argentinum, Le. lactis and Weissella confusa were the most predominant in both cultivars. A few strains were identified as W. paramesenteroides (four strains), Lactobacillus casei (five strains), Lactococcus lactis (five strains) and Lb. rhamnosus (two strains). Lb. casei and Lb. rhamnosus were not isolated from the Prisma cultivar, while W. paramesenteroides and Lc. lactis were absent in the Clipper cultivar. Kilned malt of the Clipper cultivar contained predominantly Le. argentinum, whereas the Prisma cultivar contained mainly Lc. lactis. To our knowledge. this is the first report of LAB in Clipper and Prisma barley and the various malting phases. The influence of the various groups of lactic acid bacteria on the fermenting ability of brewers' yeast is currently being determined.

Sulfonylurea receptors inhibit the epithelial sodium channel (ENaC) by reducing surface expression.

In the kidney the epithelial Na+ channel (ENaC) is co-expressed with the sulfonylurea receptor (SUR), an ABC protein that shares a high degree of homology with the cystic fibrosis transmembrane conductance regulator (CFTR) and reportedly modifies ENaC in various preparations. To investigate a possible regulatory relationship between SUR and ENaC, we performed co-expression studies on Xenopus laevis oocytes, which were assayed for amiloride-sensitive currents (DeltaIami). Moreover, a chemiluminescence assay was used to investigate the surface expression of extracellular hemagglutinin-tagged SUR1 (SUR1-HA) or HA-tagged ENaC (ENaC-HA). In oocytes co-injected with SUR1/ENaC (or SUR2B/ENaC) DeltaIami was reduced by congruent with 53% (or congruent with 45%) compared to DeltaIami measured in matched control oocytes injected with ENaC alone. The inhibitory effect of SUR on DeltaIami was preserved in oocytes expressing ENaC with C-terminally truncated subunits. Co-expression of SURs did not confer sensitivity of DeltaIami to diazoxide, pinacidil, tolbutamide, or glibenclamide. ENaC does not facilitate the surface expression of SUR1-HA, which is known to be retained in the endoplasmatic reticulum (ER) by an ER-retention/retrieval signal. SUR1-HAAAA, a mutant that lacks this signal, still inhibits ENaC currents. Chemiluminescence was reduced by congruent with 49% in oocytes co-expressing ENaC-HA/SUR1 compared to that in control oocytes expressing ENaC-HA alone. We conclude that SUR does not interact with ENaC at the level of the plasma membrane but that it inhibits DeltaIami by reducing surface expression of the channel.

Mapping and expression pattern analysis of key components of the major histocompatibility complex class I antigen processing and presentation pathway in a representative human renal cell carcinoma cell line.

Renal cell carcinoma (RCC) represent approximately 5% of all cancer deaths. At the time of presentation, over 50% of the patients have already developed locally advanced or metastatic disease with five-year survival rates of less than 20%. Although relative resistant to conventional regimens, RCC are partially susceptible to T cell-based immunotherapy. To further develop this treatment modality, two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) was applied for both the mapping of the key components of the major histocompatibility complex (MHC) class I antigen processing and presentation machinery (APM) and the characterization of the constitutive and cytokine-regulated protein expression profiles in a representative human RCC cell line. The latter aspect is based on the fact, that the expression level of some of the APM components can be altered in response to interferon (IFN)-gamma treatment. Total cell lysates from untreated and IFN-gamma-treated tumor cells were separated on 2-D PAGE gels using broad range immobilized pH gradient (IPG) strips. Serial Western blot analyses using sets of APM-specific antibodies were performed to target the relevant protein spots. Protein verification was mostly accomplished via peptide mass finger-printing using matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS). To date, the majority of the APM-related components have been identified and mapped. In addition, the different protein expression profiles of untreated and IFN-gamma-treated RCC cells are under investigation.

Ovine male genital duct epithelial cells differentiate in vitro and express functional CFTR and ENaC.

To investigate the biology of the male genital duct epithelium, we have established cell cultures from the ovine vas deferens and epididymis epithelium. These cells develop tight junctions, high transepithelial electrical resistance, and a lumen-negative transepithelial potential difference as a sign of active transepithelial ion transport. In epididymis cultures the equivalent short-circuit current (I(sc)) averaged 20.8+/-0.7 microA/cm(2) (n = 150) and was partially inhibited by apical application of amiloride with an inhibitor concentration of 0.64 microM. In vas deferens cultures, I(sc) averaged 14.4+/-1.1 microA/cm(2) (n = 18) and was also inhibited by apical application of amiloride with a half-maximal inhibitor concentration (K(i)) of 0.68 microM. The remaining amiloride-insensitive I(sc) component in epididymis and vas deferens cells was partially inhibited by apical application of the Cl(-) channel blocker diphenylamine-2-carboxylic acid (1 mM). It was largely dependent on extracellular Cl(-) and, to a lesser extent, on extracellular HCO(-)(3). It was further stimulated by basolateral application of forskolin (10(-5) M), which increased I(sc) by 3.1+/-0.3 microA/cm(2) (n = 65) in epididymis and 0.9+/-0.1 microA/cm(2) (n = 11) in vas deferens. These findings suggest that cultured ovine vas deferens and epididymis cells absorb Na(+) via amiloride-sensitive epithelial Na(+) channels (ENaC) and secrete Cl(-) and HCO(-)(3) via apical cystic fibrosis transmembrane conductance regulator (CFTR) Cl(-) channels. This interpretation is supported by RT-PCR data showing that vas deferens and epididymis cells express CFTR and ENaC mRNA.