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Phospholipids are a main component of cell membranes. Therefore, the experimental investigation of the self-organization of phospholipids is of great interest. Here we present results concerning the orientation of the phospholipid 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) at the surface of the polar solvents formamide and 3-hydroxypropionitrile (HPN), which we investigated by means of neutral impact collision ion scattering spectroscopy. It is shown that, in HPN, at low POPC surface excesses, the phospholipids are oriented with the polar headgroups pointing out of the solution. It is concluded that the behavior of lipids at the surface of liquids is more complex than expected and to a great extent dependent on the solvent. Comprehension of the behavior of POPC in the applied solvents might contribute to the understanding of the self-organization of phospholipids in water.

Use of forbs in revegetation projects in the Great Basin is limited due to high seed cost and insufficient understanding of their germination and establishment requirements. We tested the effects of seeding depth from 0 to 25.4 mm (1 in) on emergence and survival in clay and sandy loam soils of 5 ecologically important forbs. Significantly less emergence occurred of gooseberry-leaf globemallow ( Sphaeralcea grossulariifolia (Hook. & Arn.) Rydb. [Malvaceae]) without a 3.2 mm covering of soil in both soil textures (14% and 19% reductions, respectively). Mountain dandelion ( Agoseris glauca (Pursh) Raf. [Asteraceae]), Utah milkvetch ( Astragalus utahensis (Torr.) Torr. & A. Gray [Fabaceae]), and tapertip hawksbeard ( Crepis acuminata Nutt. [Asteraceae]) had greatest emergence on the soil surface and decreased at greater depths. Scarlet globemallow ( Sphaeralcea coccinea (Nutt.) Rydb. [Malvaceae]) and S. grossulariifolia had significantly greater survival in the sand loam (71% and 87%) than in the clay soil (32% and 52%). Survival of A. utahensis and C. acuminata decreased significantly with surface seeding in the sandy loam soil. Seeding depth did not significantly impact survival of A. glauca . Seeding at 25.4 mm (1 in) reduced emergence or survival for all species. Maximum emergence and survival occurred at shallower seeding depths in the clay loam for most species. Based on our results for these forbs, we recommend a seeding depth of 3.2 mm (0.13 in) in clay soil and 6.4 mm (0.26 in) for sandy loam soil.

Objective The aim of this study was to investigate the role of p16 in tumorigenesis of endometrial carcinoma (EC). Methods Expression of p16 protein was analyzed using immunohistochemistry. The methylation status of p16 promoter region was determined by methylation-specific PCR. Deletion analysis of the p16 gene was performed by PCR-analyses. Results Aberrant protein expression of p16 was observed in 18 of 46 (39.2%) ECs and correlated significantly with p16 alterations, including gene deletions in 26 of 46 (56.5%) ECs and promoter hypermethylation in 8 of 46 (17.4%) ECs ( p p16 alterations from early stage (I–II) to advanced stage (III–IV) ECs was observed ( p =0.002). There was no significant correlation between p16 protein expression and the clinico-pathological features of EC. The development of metastases correlated significantly with the frequency of p16 alterations: p16 alterations were detected in 14 of 15 (93.3%) PTs with metastases and in only 18 of 31 (58.1%) PTs without metastases ( p =0.018). The genetic comparison of 15 primary ECs and their paired metastases revealed that in most of the cases the deleted region of p16 gene remains the same or becomes larger during the progression from primary tumor to its corresponding metastases. Conclusion Our results suggest that p16 alterations and particularly p16 gene deletions in ECs are associated with increased incidence of metastases.

The inelastic scattering of low energy electrons from liquid glycerol has been studied. For the first time, electron energy loss spectra of liquids are sufficiently well resolved to permit the identification of vibrations corresponding to individual bonds, namely the C–H and O–H stretching vibrations in glycerol. The angular distribution of the specular peak is very broad, indicating the absence of long-range order at the surface of the liquid. The measurement of the loss signals as a function of the primary electron energy suggests a hybrid mechanism of excitation. The excitation mechanism for the O–H vibration has a stronger impact character as compared to the C–H vibration. A negative ion resonance of glycerol is found at a primary energy of 8 eV. The signal intensities measured as a function of the specular angle of the electron beam appear to be influenced by the angular dependence of the dipole and impact scattering cross-section and a possible preferred orientation of the C–H and O–H groups at the surface of the liquid.

Schlanke Prozesse und ein optimaler Ressourceneinsatz mit durchgangigen IT-Systemen ohne Medienbruche sind Ziele, die viele Unternehmen heute verfolgen. Es soll Zeit und Geld sparen und gleichzeitig das Effizienz- und Qualitatsniveau der Arbeit steigern. Nicht selten werden in den Aufbau- und Ablauforganisationen der Unternehmen Arbeiten doppelt verrichtet, Entscheidungen verzogert umgesetzt, weil etwa die Rollen und Verantwortlichkeiten nicht eindeutig geregelt sind oder auch „Schatten-IT-Systeme“ parallel zur offiziellen IT-Landschaft vorgehalten werden. Diese organisationalen Spannungsfelder pragen den Unternehmensalltag. Auch vor diesem Hintergrund sind Projekte zur Prozessoptimierung fruher oder spater bei fast allen Unternehmen auf der Tagesordnung – gleich welcher Grosenordnung und Branche.

Microfluidic devices can be used for either pre-mix emulsification (a method in which a coarse emulsion is broken up by passing it through a geometry) or direct emulsification (a method in which oil and water are introduced separately in the device and the emulsion is formed at their point of contact). Depending on the surface properties of the microfluidic device or other microstructured device (e.g. membrane) either oil-in-water (hydrophilic device) or water-in-oil (hydrophobic device) emulsions are formed. Also related products, such as double emulsions, particles and capsules are reported in literature. For an extensive description of the construction of various microfluidic devices for emulsion preparation, and the various products that have been reported, please consult the recent comprehensive review by Vladisavljevic, Kobayashi, and Nakajima [1]. For further reading also the review on droplet based microfluicics by Seeman and co-workers [2] is highly recommended. In the current chapter, the most used microfluidic devices are described, and compared using criteria based on scaling relations, ease of operation and productivity. In the future research section, the use of these devices as tools for dynamic interfacial tension measurement, and emulsion stability are discussed amongst others.

Hydrocyclones enhance oil–water separation efficiency compared to conventional separation methods. An efficient collision detection scheme with Np ln Np dependency on the number of particles is proposed. The scheme is developed to investigate the importance of particle–particle interaction for flow and particle behavior in dilute oil–water separators. However, the proposed scheme can also be used for efficient multigrid soft collision calculation with long-range particle–particle interaction models. The collision detection scheme is first validated using a case of settling spheres. Subsequently, the scheme is applied to a simplified flow field, similar to the flow fields observed in hydrocyclones.

Lightweight and functional integration are two major drivers for additive manufacturing technologies. In order to integrate functionality, the use of smart materials like Nickel-Titanium (NiTi) shape memory alloys (SMAs) is a constructive approach. Generally, shape memory alloys are hard to machine and at the same time expensive materials. In this context, additive manufacturing processes like laser metal deposition are reasonable technologies to process these materials as the used powder can be recycled and near net shape geometry can be generated due to a layer-by-layer build-up process. For actuator applications, it might be reasonable to use hybrid systems, meaning just certain sections of a part are made of a shape memory material. One possible example is a NiTi shape memory element on a Ti sheet metal. Due to the varying coefficients of thermal expansion, a dissimilar build-up by means of laser metal deposition without any defects like cracks is challenging. In this paper, an approach that applies p...

Background Severe congenital diaphragmatic hernia (CDH) is prenatally managed by fetoscopic tracheal occlusion (FETO) to improve lung growth and maturation. As FETO is not able to reduce the pressure onto the developing lungs originating from the intestine growing into the thoracic cavity, fetal abdominal decompression may alleviate this pressure effect by directing the growing intestine into the amniotic cavity away from the lungs. Therefore, aim of this study was to establish an animal model for fetoscopic abdominal decompression in fetal sheep with CDH. Methods CDH was created surgically on day 75 of 145 day gestation in eight fetuses. 2-3 weeks later, an opening was created in the fetal abdomen by fetoscopic surgery. The fetuses were retrieved by cesarean section at the end of pregnancy and evaluated. Results Five fetuses with CDH were treated with fetoscopic abdominal decompression. Three fetuses with CDH were taken as controls. One fetus was lost after creation of the CDH and two other after creation of the abdominal defect. Preliminary sterological results showed that the septal thickness of the experimental group was smaller than in the CDH group. Conclusion This study demonstrates the general feasibility of fetoscopic abdominal decompression for diaphragmatic hernia in our new animal model. Although not statistically significant, the lungs of treated fetuses were larger and heavier than those of untreated controls. Our findings support the hypothesis of palliative fetal surgery for severe CDH compared to tracheal occlusion. More controlled animal trials are needed.

INTRODUCTION Aim of this study was to compare the short-term outcome of transumbilical laparoscopic-assisted (TULAA) with laparoscopic (LA) and open appendectomy (OA) in a case-control study. MATERIALS AND METHODS Our first 20 consecutive children with appendicitis treated with TULAA were matched to 20 patients treated with LA and OA, respectively. Matching criteria were age, sex, and the histology of appendicitis. The children were retrospectively evaluated for outcome, efficacy, and complications. RESULTS No significant differences between the groups were found, except that children operated by OA required less analgesics than children operated by LA and TULAA. DISCUSSION TULAA appears to be a safe procedure with no disadvantage except for postoperative pain, which needed a longer course of analgesics compared to OA. Whether TULAA has advantages over LA and OA has to be evaluated in larger prospective series.

Background Prospective data of transumbilically laparoscopic-assisted appendectomies (TULAA) is absent in the pediatric population. We therefore compared the midterm outcome of TULAA with open (OA) and laparoscopic (LA) appendectomies in children with appendicitis in a matched prospective study. Methods A total of 20 patients operated with TULAA were matched to 20 cases operated by LA and OA, respectively, according to sex, age, and histology of the resected appendix. All 60 children were evaluated during a 3-month follow-up visit. Results The subjective pain level after discharge, the rate of complications, and persistent painful wound as well as the duration of days refraining from school or kindergarten were similar in all three groups. The wound satisfaction was significantly higher in TULAA and LA. Children operated with TULAA had a faster return to full physical activity compared with OA. Conclusion Our data suggest that TULAA, LA, and OA have a similar outcome 3 months after surgery apart from cosmetic appearance of the wound and return to full physical activity in pediatric patients. Whether parental bias or the increased wound satisfaction act as confounders for early return to full physical activity should be evaluated in larger prospective randomized trials.

A pilot study was conducted to investigate the influence of electromagnetic fields in the short-wave range (3-30 MHz) radio transmitter signals on salivary melatonin concentration in dairy cattle. The hypothesis to be tested was whether EMF exposure would lower salivary melatonin concentrations, and whether removal of the EMF source would be followed by higher concentration levels. For this pilot study, a controlled intervention trial was designed. Two commercial dairy herds at two farms were compared, one located at a distance of 500 m (exposed), the other at a distance of 4,000 m (unexposed) from the transmitter. At each farm, five cows were monitored with respect to their salivary melatonin concentrations over a period of ten consecutive days. Saliva samples were collected at two-hour intervals during the dark phase of the night. As an additional intervention, the short-wave transmitter was switched off during three of the ten days (off phase). The samples were analyzed using a radioimmunoassay. The average nightly field strength readings were 21-fold greater on the exposed farm (1.59 mA/m) than on the control farm (0.076 mA/m). The mean values of the two initial nights did not show a statistically significant difference between exposed and unexposed cows. Therefore, a chronic melatonin reduction effect seemed unlikely. However, on the first night of re-exposure after the transmitter had been off for three days, the difference in salivary melatonin concentration between the two farms (3.89 pg/ml, CI: 2.04, 7.41) was statistically significant, indicating a two- to seven-fold increase of melatonin concentration. Thus, a delayed acute effect of EMF on melatonin concentration cannot completely be excluded. However, results should be interpreted with caution and further trials are required in order to confirm the results.

The pathogenesis of intestinal dysmotility in gastroschisis is not completely understood. Peel formation and disorganization of interstitial Cajal cells (ICC) have been proposed in humans. The aim of this study was to evaluate the impact of prenatal coverage of gastroschisis on gut inflammation and expression of ICC in a fetal lamb model. Twenty-one German blackhead sheep with an abdominal wall defect that was created fetoscopically on day 77 of 145 days gestation were used in this study. Intrauterine surgery with the aim to cover the defect was performed 3 weeks later; two fetuses were covered completely, 5 partially and 11 remained uncovered. Three fetuses without gastroschisis were used as controls. All fetuses were retrieved by cesarean section at day 135. Samples of the small intestine were stained with hematoxylin and eosin for histologic analysis of peel formation and serosal and muscular thickness. For ICC detection, immunohistochemistry using anti-CD117 (c-Kit) antibody was used. In all samples with exposure to amniotic fluid, peel formation and significantly decreased ICC were found. Complete coverage reduced peel formation and disorganization of ICC compared to uncovered animals almost to the level of controls. Peel formation and ICC derangement were significantly reduced by prenatal coverage of gastroschisis. Moreover, this animal model mimics the histopathological bowel changes as seen in human gastroschisis and may, therefore, be used for further research on the pathophysiology and fetal therapy of this malformation.

To test the clinical and sonographic predictors of testicular torsion (TT) with the aim of reducing negative exploration rates.We performed a prospective study of all boys treated for 'acute scrotum' at our institute between January 2001 and April 2012 and clinical findings were documented. If available, ultrasonography (US) was added to the diagnostic evaluation. A prediction of the diagnosis was based on clinical and sonographic features, and was followed by surgical exploration in all patients.A total of 104 patients were included in the 16-month period of the study. No single finding excluded TT. The clinical features (pain24 h, nausea/vomiting, abnormal cremasteric reflex, high position of the testis) appeared predictive (100% sensitivity) and the clinical scoring system was proven to be reliable, reducing the negative exploration rate by55%. Ultrasound predictors alone were not able to identify all boys with TT.It is safe to refrain from routine surgical exploration in every child with acute scrotum if the clinical score is applied, which results in a marked reduction of negative explorations. A reliable diagnosis could not be obtained based on US alone. As scrotal US is unpleasant for the child, we propose to refrain from this if the clinical score is positive. Patients with a negative clinical score are suitable candidates for US to establish and secure diagnosis.

Power Electronics on DCB are used for high power devices. There is a wide field of applications for such power electronic devices like converters or inverters for wind mills, solar parks or for electric and hybrid vehicles. High efficiency, long life time and increased power density are the major technical requirements for those devices. Especially the life time, but also the power density are limited by die attach and wire bond materials. New material solutions to overcome these limitations in life time will be discussed in this paper. Results of an active power cycling test of DCB devices supported by the failure analysis and material data will be used to demonstrate and explain the novel materials advantages versus conventional solutions.

Impalement injuries are uncommon, especially in the pediatric population. Because of the rarity of these injuries, physicians may have difficulty recognizing and treating impalement injuries appropriately. Clinical findings are sometimes innocuous, but can be life threatening. Therefore, evaluation of suspected impalement injury should involve careful history and thorough physical examination, even if there is no evidence of trauma to the perineum. We report a very rare case of rectum perforation after transanal introduction of a broomstick with almost no clinical findings. Impalement injuries are difficult to recognize, and severity may not be reflected by their external appearance. To diagnose these injuries in time, it is important to use a well-organized workup. Language: en

We report two different modes of phase inversion in surfactant-stabilized oil-in-water emulsions subjected to a unidirectional drying stress. Coalescence occurs either through a nucleation-and-growth mechanism, where coalesced pockets form and grow randomly throughout the sample, or through a coalescence front that propagates into the sample from the drying end. This drying-induced coalescence results from the development of a pressure gradient from the drying front into the bulk of the sample, established by limited water transport through the Plateau borders. Depending on the steepness of this pressure profile, coalescence occurs throughout the sample or only at the drying front. Moreover, we find that surfactant concentration plays a significant role through its effect on the critical disjoining pressure at which coalescence occurs. Very stable emulsions, characterized by a high critical pressure, tend to develop steep pressure profiles, which favours front-dominated coalescence, while unstable emulsions with low critical pressures develop shallow pressure gradients, favouring nucleation-and-growth dominated coalescence. These results offer new insights into the microscopic mechanisms governing the complex and poorly understood macroscopic phenomena during phase inversion of drying emulsions.

We report the results of experiments on the coalescence dynamics in flowing oil-in-water emulsions using an integrated microfluidic device. The microfluidic circuit permits direct observation of shear-induced collisions and coalescence events between emulsion droplets. Three mineral oils with a range of viscosities 8–70 mPa s and five silicone oils with a range of viscosities 6–100 mPa s were chosen as dispersed phase. Pure water was used as continuous phase. Trajectory analysis of colliding droplet pairs allows evaluation of the film drainage profile and coalescence time. From the coalescence times obtained for ten thousands of droplet pairs we calculate coalescence time distributions for the different emulsions. For all systems, the coalescence time decreases with increasing capillary number and increases with increasing dispersed phase viscosity. Scaling relations for the coalescence time are derived and compared with theoretical predictions. The potential of the procedure as a diagnostic tool for the prediction of emulsion stability in oil/water separation is discussed, as well as alternative applications of the microfluidic circuits.

We present the results of experiments studying droplet coalescence in a dense layer of emulsion droplets using microfluidic circuits. The microfluidic structure allows direct observation of shear-induced collisions and coalescence events between oil droplets dispersed in water. A mineral oil was chosen as the dispersed phase and a 9 wt% NaCl aqueous solution as the continuous phase. We determine the coalescence rate as a function of the droplet velocity and droplet concentration from image sequences measured with a high-speed camera. A trajectory analysis of colliding droplet pairs allows evaluation of the film drainage profile and coalescence time tc. From the coalescence times obtained for ten thousands of droplet pairs we calculate the coalescence time distributions for each set of experimental parameters, which are the mean droplet approach velocity 〈v0〉 and the mean dispersed phase fraction 〈φ〉. We discuss the potential of the procedure for the prediction of emulsion stability in industrial applications.

Power semiconductor modules are used in a wide field of applications and power ranges. Two common trends for these devices are miniaturization and cost reduction, leading to new requirements for dies, substrates and interconnect materials. As a result, the power density and therefore the operation temperature in the devices rise, creating the need for new interconnect materials. These materials must have high thermal and electrical conductivity to ensure excellent heat dissipation and thermo-mechanical stability. Consequently, the device operation temperature, which is currently limited to maximum 150°C, can be increased and the reliability of the module can be improved. The novel mAgic sinter materials feature highest thermal and electrical conductivity and can be used for operation temperatures above 150°C. This new material family provides a solution to reduce size and cost of high power semiconductor modules and, at the same time, improves the overall performance and reliability of these packages.

We present the results of experiments studying droplet coalescence in a dense layer of emulsion droplets using microfluidic circuits. The microfluidic structure allows direct observation of collisions and coalescence events between oil droplets dispersed in water. The coalescence rate of a flowing hexadecane-in-water emulsion was measured as a function of the droplet velocity and droplet concentration from image sequences measured with a high-speed camera. A trajectory analysis of colliding droplet pairs allows evaluation of the film drainage profile and coalescence time t(c.) The coalescence times obtained for thousands of droplet pairs enable us to calculate coalescence time distributions for each set of experimental parameters, which are the mean droplet approach velocity (v(0)), the mean dispersed phase fraction (φ) and the mean hydraulic diameter of a droplet pair (d(p)). The expected value E(t(c)) of the coalescence time distributions scales as E(t(c)) is proportional to (v(0))(-0.105±0.043)(d(p))(0.562±0.287), but is independent of φ. We discuss the potential of the procedure for the prediction of emulsion stability in industrial applications.

The breakup of crude oil emulsions to produce clean oil and water phases is an important task in crude oil processing. We have investigated the demulsification kinetics of a model oil-in-water emulsion in a centrifugal field to mimic the forces acting on emulsion droplets in oil/water separators such as hydrocyclones. The rate of growth of separated oil phase and the change in mean droplet diameter of the emulsion layer was measured as a function of surfactant concentration, centrifugal acceleration and time. Demulsification is enhanced with increasing centrifugal acceleration and time and decreasing surfactant concentration. A kinetic analysis was performed that allows to estimate the characteristic coalescence times between droplets in the emulsion and between a droplet and the separated oil interface. The experimental procedure presented in this work can serve as a simple, but useful test to predict the separation efficiency of emulsions in separators with swirling flow fields.

To explore the role of transforming growth factor-beta (TGF beta) isoforms and other growth-related genes during prostate morphogenesis in the mouse, we examined mRNA levels in fetal day 17 urogenital sinus, mesenchyme (UGM), and epithelium (UGE) as well as in the ventral, dorsal, and anterior lobes of the adult prostate. In addition, we used antiserum specific for extracellular TGF beta 1 in immunohistochemical studies to localize accumulation of the TGF beta 1 isozyme in the above tissues as well as those derived from fetal day 19 and neonatal mouse prostate. Differential patterns of expression in fetal and adult tissues were seen. TGF beta 1, -beta 2, and -beta 3 expression was substantially elevated in UGM compared to that in UGE, yet only TGF beta 1, not TGF beta 2 or TGF beta 3, mRNA levels were sustained in adult prostate tissues. High levels of accumulation of TGF beta 1 were demonstrated by immunohistochemistry in the mesenchymal compartment compared to those in the epithelial compartment throughout development. Interestingly, the highest levels of TGF beta 1 appeared in areas of active epithelial duct formation and delineated the mesenchymal architectural changes necessary for ductal network formation. Additional studies revealed that levels of mRNAs for other genes involved in tissue remodeling and growth were also elevated in UGM compared to those in UGE. Tissue plasminogen activator, urokinase plasminogen activator, androgen receptor, and c-myc mRNA levels were also elevated in UGM compared to UGE. Interestingly, whereas tissue plasminogen activator mRNA levels, like those of TGF beta 2 and -beta 3, were barely detectable in adult prostatic tissues, mRNA levels for urokinase plasminogen activator, androgen receptor, and c-myc were readily detected and expressed in a lobe-specific fashion. Overall, these data indicate that expression of TGF beta 1 isoforms and other growth-related genes is associated with mesenchymal cells in areas of active morphogenesis during prostate development and provide objective molecular and cellular information regarding mediators of mesenchymal-epithelial interactions in prostate.

We investigated the methylation status of mismatch repair gene hMLH1 in 80 primary human endometrial carcinomas (ECs) and in 30 metastatic lesions. It was correlated to the expression of hMLH1 protein, microsatellite instability (MSI) of ECs and to the well-known clinico-pathological variables of cancer. The hMLH1 promoter methylation was detected in 24 out of 64 (37.5 %) primary ECs but only in one out of 18 (5.6 %) metastatic lesions investigated. Promoter hMLH1 hypermethylation was found more often in early stage ECs and was associated with a decrease of hMLH1 protein expression immunohistochemically. An inverse relationship between hMLH1 expression and clinical stage of the disease was found (p = 0.048). Interestingly, there was a significant correlation between MSI and hMLH1 protein expression level (p = 0.042). MSI phenotype was found more often in EC metastases compared to the primary tumors (66.7 % vs 29.3 %; p = 0.039). However, neither hMLH1 promoter hypermethylation nor MSI was independent predictive factors for patient’s outcome. Using an in vitro model we showed that hMLH1 methylation is reversible. These data showed that hMLH1 methylation with a consequent protein decrease occurred early during EC tumorigenesis and may cause a MSI phenotype, which occurs relatively late. MSI may be an important mechanism supporting further the tumor progression. These findings may have importance for the specific chemosensitization of the primary tumors/metastases and can improve our understanding of endometrial carcinogenesis in humans.

Conductive adhesives provide advantageous properties for many electronics assembly applications (low processing temperatures, high flexibility) and they are green materials. However, the limited electrical and thermal conductivity of conventional conductive adhesives restrict their usage in most cases to low to medium power density packages. The novel mAgic silver sinter adhesives feature the conventional positive properties of conductive adhesives and combine them with electrical and thermal conductivity that are comparable to solder. This new development therefore provides solutions to the growing challenge of increasing power densities related to shrinkage of packages and / or increase of power.

Gastroschisis is a malformation consisting of an abdominal wall defect with eviscerated bowel. Its standard treatment is postnatal repositioning or temporary prosthetic bag placement. The aim of our study is to evaluate the feasibility of its fetoscopic management in a lamb model. At mid-gestation (day 75), gastroschisis was created in eight German blackhead sheep. A second fetoscopic procedure was performed on day 105, assessing the viability, extension, and potential for repositioning of eviscerated bowel. The fetus was retrieved by Cesarean section on day 132 and evaluated. In six fetuses gastroschisis could be successfully created and assessed with fetoscopy. Two fetuses were lost due to technical complications. Primary repair by repositioning the intestine into the abdomen was not possible because it grew into an inflammatory conglomerate too large for the small fetal abdominal cavity. Although technically demanding, we were able to produce and reassess six cases of gastroschisis by fetoscopy. As primary repositioning appears unfavorable, fetoscopic prosthetic bag placement may become an alternative.

Mouse prostate reconstitution is a useful model for studying the progression of ras + myc-induced carcinomas. When these oncogenes were introduced into both the epithelial and the mesenchymal compartments, poorly differentiated adenocarcinomas resulted. Restricted introduction of both oncogenes into the epithelium produced epithelial hyperplasia. Malignancies were produced in two out of 17 cases of selectively transformed epithelium, suggesting that the hyperplastic condition represents a premalignant phenotype. Restricted introduction of both oncogenes into the mesenchyme produced only mesenchymal dysplasia. Transforming growth factor-beta 1 (TGF-beta 1) and beta 3 (TGF-beta 3) mRNA levels were elevated in the ras + myc-induced carcinomas when compared to the normal controls or to the epithelial hyperplasias. In contrast, TGF-beta 2 mRNA levels were similar in all control and ras + myc-induced carcinomas. Elevated TGF-beta 1 mRNA levels were also found in mesenchymal dysplasia pointing to a potential paracrine activity by the ras + myc transformed mesenchyme. We conclude that elevated TGF-beta 1 and beta 3 are correlated with progression to malignancy and that mesenchyme derived TGF-beta 1 may play an important role in the promotion of ras + myc-induced carcinomas in this model system.

The chemical potential of a surfactant in solution can be calculated from the Gibbs adsorption equation when the surface excess of the surfactant and the surface tension of the solution as a function of surfactant concentration are known. We have investigated a solution of the nonionic surfactant 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) in the polar solvent 3-hydroxypropionitrile at concentrations below and above the critical micelle concentration (cmc). Neutral impact collision ion scattering spectroscopy was applied for the direct measurement of the surface excess of POPC as a function of concentration. The Gibbs adsorption equation was applied in conjunction with surface tension measurements to evaluate the chemical potential and the activity coefficients of POPC, respectively. We find that the solution shows ideal behavior up to the cmc and that the chemical potential remains constant at concentrations larger than the cmc.

Neutral impact collision ion scattering spectroscopy under normal incidence is known to yield the concentration depth profiles of all elements except hydrogen at the surface of liquids and other amorphous material. In the evaluation of the data one tactically has to assume that the top surface layer and the adjacent layers are laterally homogeneous. In the present paper we establish that the angular resolved mode of this spectroscopy is able to test with high accuracy whether the lateral homogeneity is valid and-if this is not the case-in which way the top layer is structured. In particular, it is possible to map out the local environment of selected atoms. We expect that this so far inaccessible information on the local topography at liquid surfaces will have an impact on the understanding of reactions at the gas/liquid interface.

Informations- und Kommunikationssysteme werden zunehmend zu zentralen Komponenten einer Gesellschaft. Praktisch alle Industrie-, Handels- und Dienstleistungsunternehmen sowie staatliche Organisationen betreiben zur eflizienten Verarbeitung immer komplexer werdender Aufgaben Systeme der Informationstechnik (IT-Systeme). Informationen uber Geschaftsergebnisse, Strategieplane, Logistikinformationen und Kundendaten stellen einen erheblichen Wert dar. Daher werden sie vielfach als Produktionsfaktor verstanden, ahnlich wie Vermogenswerte, deren Schutz essentiell ist. Dies hat insbesondere fur Kreditinstitute eine herausragende Bedeutung. Ein umfassendes Sicherheitsbewustsein und eine entsprechende Sicherheitspolitik sind daher unabdingbare Voraussetzungen fur einen dem Stellenwert gerechten Umgang mit Informationen. Bei der Absicherung von Informations- und Kommunikationssystemen sind insbesondere die folgenden Grundwerte zu betrachten: Verfugbarkeit: Es ist sicherzustellen, das Daten dann verfugbar sind, wenn sie benotigt werden. Aber auch Kommunikationsverbindungen mussen verfugbar sein. Beispielsweise kann es fur einen Kunden oder einen Finanzdienstleister wesentlich sein, innerhalb bestimmter Fristen auf Informationen des Unternehmens zugreifen oder bestimmte Aktionen (z.B. Wertpapieran- und verkaufe) auslosen zu konnen. Die Verfugbarkeit last sich nicht durch Sicherheitsfunktionen (wie z.B. kryptographische Verfahren), sondern nur durch infrastrukturelle oder organisatorische Masnahmen (z.B. redundante Auslegung von Netzverbindungen, Back-up-Server) erreichen. Integritat: Sensitive Daten sind so zu schutzen, das sie nicht unbemerkt verandert werden konnen (z.B. Kontoangaben, Betrage, Auftrage). Ebenso sind Kommunikationsverbindungen so abzusichern, das Daten bei der Ubertragung nicht unbemerkt verandert werden konnen. Ein typisches Beispiel sind Auftrage im Zahlungsverkehr, bei denen z.B. sowohl Anderungen an den angegebenen Betragen als auch an den Kontoangaben verhindert bzw. zuverlassig erkannt werden mussen. Vertraulichkeit: Sensitive Daten sind so zu schutzen, das sie nicht Unbefugten zuganglich gemacht werden konnen. Ebenso ist fur Kommunikationsverbindungen sicherzustellen, das die ubertragenen Daten vertraulich bleiben. Authentizitat (Verbindlichkeit): Bei sensitiven Daten ist wie bei ihren handschriftlichen Entsprechungen die Urheberschaft der Daten und damit ihre Echtheit zu sichern. Dies kann zum Beispiel dann notig werden, wenn die Verbindlichkeit eines Kundenauftrags oder einer Verfugung gewahrleistet und spater uberpruft werden soil. Kommunikationsverbindungen sind so zu schutzen, das die Identitat der beteiligten Kommunikationspartner stets bekannt und sichergestellt ist. So ist es beispielsweise fur Kunden wichtig, sicher zu wissen, das sie mit dem gewunschten Unternehmen oder Kreditinstitut verbunden sind, wenn sie dem Unternehmen vertrauliche Informationen ubergeben. Umgekehrt ist es in bestimmten Fallen auch fur das Kreditinstitut wichtig, die Identitat des Kommunikationspartners sicher zu kennen, da diese beispielsweise Grundlage fur die Berechtigung zu bestimmten Aktionen (z.B. Verfugungsberechtigung) oder auch zum Empfang bestimmter Informationen (bei Kunden z.B. Kontooder Depotstand, bei Mitarbeitern z.B. Zugriff auf bankinterne Informationen) ist.

In response to the question "What is your favorite element?" this article offers an introduction to fictional chemical elements in fantasy and science fiction.

As-deposited films of multilayered polyelectrolytes are considered to be non-equilibrium structures. Due to the strong attraction between oppositely charged polyions, polyelectrolyte interdiffusion is thought to be suppressed during the adsorption process. Equilibration is promoted by a decrease of the electrostatic attraction between polyion pairs. We have used neutral impact collision ion scattering spectroscopy to investigate the influence of polyelectrolyte multilayer annealing in water and aqueous 1 M NaCl solutions at different temperatures (20 and 70 degrees C) on the increase in interpenetration of a single polyelectrolyte layer throughout the whole film. The multilayers were composed of poly(4-vinylpyridinium) and poly(4-styrenesulfonate). Contrast between neighboring layers was established by labelling the layer in question with the heavy atom ruthenium. It is found that both temperature and salt increase layer interpenetration, whereas salt has a stronger influence than temperature. From numerical simulations polyelectrolyte diffusion coefficients were evaluated for the different annealing conditions. The influence of temperature and salt on the equilibration of the film is interpreted in terms of increased screening of polyion charges and binding of small counterions to polyion monomeric units.

Commonly, the surface excess is determined from surface tension measurements via the Gibbs equation. This equation relates the activity (chemical potential), the surface excess, and the surface tension. When knowing two out of the three quantities, the third one can be calculated. Unfortunately, in the case of surface active components the concentration is in most cases too low to determine the activity from a measurable change in the bulk properties and thus assumptions are made about the activity coefficients. However, if the surface excess is measured directly and the surface tension is known, the activity can be determined making use of the Gibbs equation. The surface excess is the quantity of a surfactant solution which changes most strongly with the concentration. Thus it is obvious that this procedure should be used to determine activity coefficients of surfactants. One of the few techniques for determining the surface excess directly is neutral impact collision ion scattering spectroscopy (NICISS). With NICISS concentration depth profiles can be measured in the surface near region with a depth resolution of a few angströms. The surface excess and the activities are investigated here for the system tetrabutylphosphonium bromide (Bu4PBr) dissolved in the polar solvent formamide.