Tracing Photoinduced Hydrogen Migration in Alcohol Dications from Time-Resolved Molecular-Frame Photoelectron Angular Distributions.

The recent implementation of attosecond and few-femtosecond X-ray pump/X-ray probe schemes in large-scale free-electron laser facilities has opened the way to visualize fast nuclear dynamics in molecules with unprecedented temporal and spatial resolution. Here, we present the results of theoretical calculations showing how polarization-averaged molecular-frame photoelectron angular distributions (PA-MFPADs) can be used to visualize the dynamics of hydrogen migration in methanol, ethanol, propanol, and isopropyl alcohol dications generated by X-ray irradiation of the corresponding neutral species. We show that changes in the PA-MFPADs with the pump-probe delay as a result of intramolecular photoelectron diffraction carry information on the dynamics of hydrogen migration in real space. Although visualization of this dynamics is more straightforward in the smaller systems, methanol and ethanol, one can still recognize the signature of that motion in propanol and isopropyl alcohol and assign a tentative path to it. A possible pathway for a corresponding experiment requires an angularly resolved detection of photoelectrons in coincidence with molecular fragment ions used to define a molecular frame of reference. Such studies have become, in principle, possible since the first XFELs with sufficiently high repetition rates have emerged. To further support our findings, we provide experimental evidence of H migration in ethanol-OD from ion-ion coincidence measurements performed with synchrotron radiation.

A randomised multicentre phase II study with cisplatin/docetaxel vs oxaliplatin/docetaxel as first-line therapy in patients with advanced or metastatic non-small cell lung cancer.

BACKGROUND: This study was designed to compare cisplatin/docetaxel with oxaliplatin/docetaxel in patients with advanced and metastatic non-small lung cancer as a first-line treatment. METHODS: Patients were randomly assigned to receive either cisplatin 75 mg m(-2) and docetaxel 75 mg m(-2) every 3 weeks or oxaliplatin 85 mg m(-2) and docetaxel 50 mg m(-2) every 2 weeks. The primary end point was response rate, and secondary end points were toxicity, time to progression and overall survival. RESULTS: A total of 88 patients (median age: 65 (39-86) years; stage IV: 93%) were randomly assigned. Response rate (complete and partial response) was 47% (95% CI: 33-61%) in the cisplatin/docetaxel arm and 28% (95% CI: 17-43%) in the oxaliplatin/docetaxel arm (P=0.118). There was no significant difference in time to progression (6.3 vs 4.9 months, P=0.111) and median overall survival (11.6 vs 7.0 months, P=0.102) with cisplatin/docetaxel vs oxaliplatin/docetaxel, although slight trends favouring cisplatin were seen. Oxaliplatin/docetaxel was associated with significantly less (any grade) renal toxicity (56% vs 11%), any grade fatigue (81% vs 59%), complete alopecia (76% vs 27%), any grade leukopenia (84% vs 61%) and grade 3/4 leukopenia (44% vs 14%) and neutropenia (56% vs 27%). CONCLUSION: Oxaliplatin/docetaxel has activity in metastatic non-small cell lung cancer, but it seems to be inferior to cisplatin/docetaxel.

Addressing Community Health Needs through the Development of a Student-Led Community Health Fair.

This article was migrated. The article was marked as recommended. PROBLEM: Based on a specific community benefit analysis of Greenville, South Carolina, we identified the Dunean community with its increased prevalence of health inequities with respect to access to health care, poverty burden, and disease mortality on a county, state, and national level. The Dunean community's data reflect poorer health outcomes in terms of disease and unhealthy lifestyle as well as inadequate access to medical resources compared to other communities in South Carolina. APPROACH: Students, residents, attendings, faculty, and staff from the University of South Carolina School of Medicine Greenville (UofSC SOMG) formed a task force to engage the community and combat the root causes of diseases. This task force built partnerships with community leaders to create Root Cause, a monthly health event designed to bring community members to a unified space, share a free community dinner, and provide a wide range of health and wellness resources to educate and inspire them to make healthy lifestyle choices. Outcomes: This report describes the formation of the community engagement task force and execution of Root Cause. In five Root Cause events, we partnered with 36 community agencies and our academic health center partners who shared their resources, served 207 Dunean neighborhood members, and facilitated 1,237 total interactions between community members and partners. CONCLUSION: Under the Root Cause model, medical students and neighborhood partners have initiated a trusted, bidirectional dialogue to determine their specific needs with the desire to positively transform the health and wellness of the Dunean community. Our data suggests that based on our efforts, the neighborhood of Dunean, SC increased community cohesiveness and improved perceptions of access to health care. Additionally, participating medical students advanced their understanding of social health and economic challenges which helped to facilitate their development along the active citizen continuum, as well as increase empathy for their future patients in the local community.

Panton-Valentine leukocidin-positive Staphylococcus aureus in skin and soft tissue infections from primary care patients.

OBJECTIVES: To characterize deep skin and soft tissue infections (dSSTI) caused by Panton-Valentine leukocidin (PVL)-positive versus PVL-negative Staphylococcus aureus isolates. METHODS: We performed a retrospective analysis of patients' records including S. aureus isolates from outpatients with dSSTI. Samples had been submitted by primary care physicians, i.e. general practitioners, surgeons, dermatologists and paediatricians, located in Berlin, Germany, in 2007-2017. Bacterial isolates were identified and tested for antimicrobial susceptibility by VITEK 2; PVL was detected by PCR. RESULTS: In total, 1199 S. aureus isolates from 1074 patients with dSSTI were identified, and 613 (51.1%) of 1199 samples were PVL+. The median age of patients with PVL+S. aureus was lower than in patients with PVL- S. aureus (34 years, range 0-88 years, vs. 44 years, range 0-98 years; p < 0.0001). PVL was associated with repeated/multiple samples compared to single sample submission (69/92, 75% vs. 448/982, 45.6%, p < 0.0001; odds ratio (OR), 3.6; 95% confidence interval (CI), 2.2-5.8). Interestingly, the highest PVL positivity rate was found in isolates from gluteal (82/108, 75.9%; OR, 3.6; 95% CI, 2-5) or axillary (76/123, 61.8%; OR, 2; 95% CI, 1.1-3.3) localizations compared to isolates from the arm. The PVL positivity rate did not increase over time. Yet we noticed an increase in the trimethoprim/sulfamethoxazole (SXT) resistance rate in PVL+ isolates, mainly methicillin-sensitive S. aureus, when considering SXT resistance rates of 2007-2012 versus 2013-2017 (35/226, 15.5% vs. 74/289, 25.6%; p 0.01). CONCLUSIONS: In outpatients, gluteal and axillary dSSTI are indicative of PVL+S. aureus. Providing SXT as a complementary treatment for dSSTI should be based on susceptibility testing.

Matrix-assisted laser desorption ionization-time of flight mass spectrometry for fast and reliable identification of clinical yeast isolates.

The clinical impact of severe infections with yeasts and yeast-like fungi has increased, especially in immunocompromised hosts. In recent years, new antifungal agents with different and partially species-specific activity patterns have become available. Therefore, rapid and reliable species identification is essential for antifungal treatment; however, conventional biochemical methods are time-consuming and require considerable expertise. We evaluated matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) for the rapid routine identification of clinical yeast isolates. A total of 18 type collection strains and 267 recent clinical isolates of Candida (n = 250), Cryptococcus, Saccharomyces, Trichosporon, Geotrichum, Pichia, and Blastoschizomyces spp. were identified by MALDI-TOF MS. The results were compared with those obtained by conventional phenotyping and biochemical tests, including the API ID 32C system (bioMérieux, Nürtingen, Germany). Starting with cells from single colonies, accurate species identification by MALDI-TOF MS was achieved for 247 of the clinical isolates (92.5%). The remaining 20 isolates required complementation of the reference database with spectra for the appropriate reference strains which were obtained from type culture collections or identified by 26S rRNA gene sequencing. The absence of a suitable reference strain from the MALDI-TOF MS database was clearly indicated by log(score) values too low for the respective clinical isolates; i.e., no false-positive identifications occurred. After complementation of the database, all isolates were unambiguously identified. The established API ID 32C biochemical diagnostic system identified 244 isolates in the first round. Overall, MALDI-TOF MS proved a most rapid and reliable tool for the identification of yeasts and yeast-like fungi, with the method providing a combination of the lowest expenditure of consumables, easy interpretation of results, and a fast turnaround time.

Visualization of the peroxisomal compartment in living mammalian cells: dynamic behavior and association with microtubules.

Peroxisomes in living CV1 cells were visualized by targeting the green fluorescent protein (GFP) to this subcellular compartment through the addition of a COOH-terminal peroxisomal targeting signal 1 (GFP-PTS1). The organelle dynamics were examined and analyzed using time-lapse confocal laser scanning microscopy. Two types of movement could be distinguished: a relatively slow, random, vibration-like movement displayed by the majority (approximately 95%) of the peroxisomes, and a saltatory, fast directional movement displayed by a small subset (approximately 5%) of the peroxisomes. In the latter instance, peak velocities up to 0.75 micron/s and sustained directional velocities up to 0.45 micron/s over 11.5 microns were recorded. Only the directional type of motion appeared to be energy dependent, whereas the vibrational movement continued even after the cells were depleted of energy. Treatment of cells, transiently expressing GFP-PTS1, with microtubule-destabilizing agents such as nocodazole, vinblastine, and demecolcine clearly altered peroxisome morphology and subcellular distribution and blocked the directional movement. In contrast, the microtubule-stabilizing compound paclitaxel, or the microfilament-destabilizing drugs cytochalasin B or D, did not exert these effects. High resolution confocal analysis of cells expressing GFP-PTS1 and stained with anti-tubulin antibodies revealed that many peroxisomes were associated with microtubules. The GFP-PTS1-labeled peroxisomes were found to distribute themselves in a stochastic, rather than ordered, manner to daughter cells at the time of mitosis.

Pex22p of Pichia pastoris, essential for peroxisomal matrix protein import, anchors the ubiquitin-conjugating enzyme, Pex4p, on the peroxisomal membrane.

We isolated a Pichia pastoris mutant that was unable to grow on the peroxisome-requiring media, methanol and oleate. Cloning the gene by complementation revealed that the encoded protein, Pex22p, is a new peroxin. A Deltapex22 strain does not grow on methanol or oleate and is unable to import peroxisomal matrix proteins. However, this strain targets peroxisomal membrane proteins to membranes, most likely peroxisomal remnants, detectable by fluorescence and electron microscopy. Pex22p, composed of 187 amino acids, is an integral peroxisomal membrane protein with its NH2 terminus in the matrix and its COOH terminus in the cytosol. It contains a 25-amino acid peroxisome membrane-targeting signal at its NH2 terminus. Pex22p interacts with the ubiquitin-conjugating enzyme Pex4p, a peripheral peroxisomal membrane protein, in vivo, and in a yeast two-hybrid experiment. Pex22p is required for the peroxisomal localization of Pex4p and in strains lacking Pex22p, the Pex4p is cytosolic and unstable. Therefore, Pex22p anchors Pex4p at the peroxisomal membrane. Strains that do not express Pex4p or Pex22p have similar phenotypes and lack Pex5p, suggesting that Pex4p and Pex22p act at the same step in peroxisome biogenesis. The Saccharomyces cerevisiae hypothetical protein, Yaf5p, is the functional homologue of P. pastoris Pex22p.

A mobile PTS2 receptor for peroxisomal protein import in Pichia pastoris.

Using a new screening procedure for the isolation of peroxisomal import mutants in Pichia pastoris, we have isolated a mutant (pex7) that is specifically disturbed in the peroxisomal import of proteins containing a peroxisomal targeting signal type II (PTS2). Like its Saccharomyces cerevisiae homologue, PpPex7p interacted with the PTS2 in the two-hybrid system, suggesting that Pex7p functions as a receptor. The pex7Delta mutant was not impaired for growth on methanol, indicating that there are no PTS2-containing enzymes involved in peroxisomal methanol metabolism. In contrast, pex7Delta cells failed to grow on oleate, but growth on oleate could be partially restored by expressing thiolase (a PTS2-containing enzyme) fused to the PTS1. Because the subcellular location and mechanism of action of this protein are controversial, we used various methods to demonstrate that Pex7p is both cytosolic and intraperoxisomal. This suggests that Pex7p functions as a mobile receptor, shuttling PTS2-containing proteins from the cytosol to the peroxisomes. In addition, we used PpPex7p as a model protein to understand the effect of the Pex7p mutations found in human patients with rhizomelic chondrodysplasia punctata. The corresponding PpPex7p mutant proteins were stably expressed in P. pastoris, but they failed to complement the pex7Delta mutant and were impaired in binding to the PTS2 sequence.

Pex19p interacts with Pex3p and Pex10p and is essential for peroxisome biogenesis in Pichia pastoris.

We report the cloning and characterization of Pichia pastoris PEX19 by complementation of a peroxisome-deficient mutant strain. Import of peroxisomal targeting signal 1- and 2-containing peroxisomal matrix proteins is defective in pex19 mutants. PEX19 encodes a hydrophilic 299-amino acid protein with sequence similarity to Saccharomyces cerevisiae Pex19p and human and Chinese hamster PxF, all farnesylated proteins, as well as hypothetical proteins from Caenorhabditis elegans and Schizosaccharomyces pombe. The farnesylation consensus is conserved in PpPex19p but dispensable for function and appears unmodified under the conditions tested. Pex19p localizes predominantly to the cytosolic fraction. Biochemical and two-hybrid analyses confirmed that Pex19p interacts with Pex3p, as seen in S. cerevisiae, but unexpectedly also with Pex10p. Two-hybrid analysis demonstrated that the amino-terminal 42 amino acids of Pex19p interact with the carboxyl-terminal 335 amino acids of Pex3p. In addition, the extreme carboxyl terminus of Pex19p (67 amino acids) is required for interaction with the amino-terminal 380 amino acids of Pex10p. Biochemical and immunofluorescence microscopy analyses of pex19Delta cells identified the membrane protein Pex3p in peroxisome remnants that were not previously observed in S. cerevisiae. These small vesicular and tubular (early) remnants are morphologically distinct from other Pppex mutant (late) remnants, suggesting that Pex19p functions at an early stage of peroxisome biogenesis.

Globus sensation: pharyngoesophageal function, psychometric and psychiatric findings, and follow-up in 88 patients.

BACKGROUND: The globus sensation has been widely regarded as psychogenic, but organic disorders were found to be etiologically significant. OBJECTIVE: To investigate the structural, functional, psychological, and psychiatric factors possibly eliciting the globus sensation and influencing its course. METHODS: Eighty-eight patients, 67 women and 21 men (aged 22-71 years), referred to 2 tertiary care centers underwent history taking, otolaryngological examination, pharyngoesophageal videofluoroscopy and manometry, psychosocial evaluation, psychometric tests, psychiatric interview, and when indicated, esophagogastroduodenoscopy, esophageal bolus transport, gastroesophageal reflux, and gastric emptying studies. According to revealed disorders, therapy was initiated, and the outcome was studied. RESULTS: Only 15 patients had normal pharyngoesophageal function; of these 15, 6 had chronic tonsillitis or pharyngitis, 3 had thyroid adenomata, 4 had cervical spondylosis, and 1 each had dry oropharyngeal mucosa and chronic bronchitis. Of the other 73 patients, 2 had pharyngeal dysfunction, 24 had achalasia, 1 had diffuse esophageal spasms, 3 had "nutcracker esophagus," 30 had nonspecific esophageal motor disorders, and 13 had gastroesophageal reflux. Psychometry revealed no more anxiety and depression than in general medical outpatients. Of 58 patients interviewed, 37 met criteria for psychiatric disorders. Psychometric scores and psychiatric characteristics were unrelated to the sensation's course. Therapy was recommended, but only 26 patients were treated accordingly; 22 received nonspecific treatment. Follow-up 3 to 59 months later revealed that the sensation had vanished in 13 patients who had received specific treatment, 5 who had received nonspecific treatment, and 6 who had received no treatment; it was alleviated in 10 who had received specific treatment, 13 who had received nonspecific treatment, and 9 who had received no treatment; and it was unchanged in 3 who had received specific treatment, 5 who had received nonspecific treatment, and 23 patients who had received no treatment. CONCLUSIONS: Pharyngoesophageal disorders may be sensed only vaguely, inducing the globus sensation. Psychological and psychiatric characteristics could be relevant to the discomfort experienced but are unlikely to be etiologically significant.

Thermoplasma acidophilum proteasomes degrade partially unfolded and ubiquitin-associated proteins.

It is shown that proteasomes from the arachaebacterium Thermoplasma acidophilum selectively degrade substrate proteins partially unfolded by phenylhydrazine- or hydrogen peroxide-treatment. Surprisingly, the pre-incubation of the substrate proteins with ubiquitin is also sufficient to render them susceptible to proteolytic degradation by proteasomes. We propose that, upon spontaneously associating with the substrate protein, ubiquitin exerts a chaotropic effect on it; this may involve the exposure of hydrophobic segments of the polypeptide chain which are recognized by the binding sites of the proteasome.

Existence of a molecular ruler in proteasomes suggested by analysis of degradation products.

Analysis of the degradation products from two proteins, the insulin B-chain and human hemoglobin, generated by archaebacterial Thermoplasma acidophilum 20 S proteasomes, revealed an unexpectedly broad specificity. In spite of the vast number of different peptides found, they fell into a rather narrow size range. This suggests that a molecular ruler exists which determines the length of the cleavage products.

Characterization of the yeast BMH1 gene encoding a putative protein homologous to mammalian protein kinase II activators and protein kinase C inhibitors.

We describe the identification and characterization of the BMH1 gene from the yeast Saccharomyces cerevisiae. The gene encodes a putative protein of 292 amino acids which is more than 50% identical with the bovine brain 14-3-3 protein and proteins isolated from sheep brain which are strong inhibitors of protein kinase C. Disruption mutants and strains with the BMH1 gene on multicopy plasmids have impaired growth on minimal medium with glucose as carbon source, i.e. a 30-50% increase in generation time. These observations suggest a regulatory function of the bmh1 protein. In contrast to strains with an intact or a disrupted BMH1 gene, strains with the BMH1 gene on multicopy plasmids hardly grew on media with acetate or glycerol as carbon source.

In vivo trabecular microcracks in human vertebral bone.

Human vertebral cancellous bone from white males (N = 19), black males (N = 16), white females (N = 12), and black females (N = 17) was examined histologically for the presence, numerical density, and morphology of in vivo microscopic cracking (microdamage). Two patterns of microcracks, linear and cross-hatched, were observed. Linear microcracks were observed in both the central portion and near surfaces of trabeculae. Those inside trabeculae were usually single microcracks approximately 50 microns in length and were found in both cement lines and in interstitial bone matrix. Linear microcracks near the trabecular surface were usually multiple parallel cracks approximately 80 microns in length. Microcracks with a cross-hatched appearance were less prevalent. They were observed primarily in vertically oriented trabeculae and were often surrounded by an area of diffuse staining. Two-way ANOVA revealed no differences in microcrack density (Cr.Dn; #/mm2) between males and females [mean (SD) 5.13 (5.02) vs. 5.41 (6.26), respectively], but whites had significantly higher microcrack density than blacks [7.00 (5.71) vs. 3.63 (4.98), respectively, p < 0.05]. White males had a significantly higher microcrack density than black males [7.60 (5.56) vs. 2.21 (1.78), respectively, p < 0.05]. Although not statistically significant, white females also had higher microcrack density than black females. In contrast to what has been reported in the femur, regression analysis found no statistically significant relationship between microcrack density in the spine and age for any of the four race-gender groups. However, significant power relationships were found between microcrack density and bone area fraction for all groups except for black females. The difference between axial and appendicular bone remodeling rates, and their implications for microdamage accumulation, are discussed.

Labeling of peroxisomes with green fluorescent protein in living P. pastoris cells.

We exploited the light-activated fluorescent properties of the green fluorescent protein (GFP) of the jellyfish Aequorea victoria for studies on the peroxisomal sorting of polypeptides. GFP and GFP-SKL (containing a C-terminal, tripeptide peroxisomal targeting signal, SKL) were expressed from a methanol-inducible, alcohol oxidase (AOX1) promoter in the methylotrophic yeast Pichia pastoris. GFP was cytosolic, whereas the GFP-SKL fusion protein was targeted to peroxisomes, as demonstrated by biochemical fractionation of organelles on Nycodenz gradients. Neither GFP nor GFP-SKL affected the viability of yeast cells but both were fluorescent on excitation with 395-nm UV light. The subcellular locations of GFP and GFP-SKL in living yeast cells were monitored by fluorescence microscopy and their fluorescence was coupled to photo-oxidation of diaminobenzidine (DAB), resulting in the deposition of electron-dense oxidized DAB at intracellular locations of GFP derivatives. This photooxidation procedure permitted facile ultrastructural localization of GFP in cells by electron microscopy, and provided further evidence that GFP produced in P. pastoris is cytosolic, whereas GFP-SKL is peroxisomal. The GFP-SKL fusion protein is therefore a versatile reporter for the peroxisomal compartment, with many applications for studies involving peroxisomal import and biogenesis.

Decay times of surface plasmon excitation in metal nanoparticles by persistent spectral hole burning

We describe a new technique to determine the homogeneous linewidths of surface plasmon resonances of metal nanoparticles and thus measure the decay time of this collective electron excitation. The method is based on spectral hole burning and has been applied to supported oblate Ag particles with radii of 7.5 nm. From the experimental results and a theoretical model of hole burning the linewidth of 260 meV corresponding to a decay time of 4.8 fs was extracted. This value is shorter than expected for damping by bulk electron scattering. We conclude that additional damping mechanisms have been observed and reflect confinement of the electrons in nanoparticles with sizes below 10 nm.

Psychiatric disorders in patients with blepharospasm - a reactive pattern?

OBJECTIVE: The purpose of this study was to assess the life-time prevalence of all major psychiatric disorders in patients suffering from blepharospasm. METHOD: A total of 31 consecutive patients with blepharospasm attending the Department of Neurology were interviewed at the Department of Psychiatry at the University of Vienna. Patients had been submitted to standard neurological diagnostic procedures, psychiatric diagnoses were made with the help of the SCID, functional impairment was assessed by the General Assessment of Functioning Scale (GAF). RESULTS: A current or life-time psychiatric diagnosis was made for 22 patients (71%). The most frequent disorders were depressive disorders, mainly major depression (five patients, 16.1%), secondary dysthymia (six patients, 19.3%), and recurrent major depression (five patients, 16.1%). A diagnosis of simple phobia was made for seven patients (22.5%), for obsessive-compulsive disorder in three patients (9.6%). The mean GAF score of our sample was 63.1%. CONCLUSION: In contrast to previously published results, we did not find a high rate of a single specific disorder or patterns in our study sample, though by the inclusion of life-time diagnostic criteria, the majority of patients fulfilled criteria for at least one diagnosis. This might indicate the considerable negative impact of blepharospasm on the patients' lives.

Psychiatric comorbidity in patients with spasmodic torticollis.

Several studies have reported raised levels of psychopathology based on self-rating scales in patients with spasmodic torticollis. Recent publications have also proposed that psychopathology, especially symptoms of depression, might be a reaction to dystonia or constitute a nonspecific reaction pattern. To determine the actual frequency of psychiatric disorders, we evaluated 44 patients with spasmodic torticollis (20 female, 24 male; mean age 43.6 years, SD 10.4) using the standard instrument for psychiatric diagnosis in the DSM-III-R (Structured Clinical Interview Schedule, SCID). The SCID permits retrospective diagnosis for most of the major psychiatric disorders, including the time before onset of dystonia. SCID criteria for at least one psychiatric disorder were fulfilled in 65.9% of patients, including both lifetime and current diagnosis. The most frequent diagnostic categories were panic disorder with or without agoraphobia (29.5%), major depressive disorder (25%), substance abuse (13.6%), and obsessive compulsive disorders (6.8%) were diagnosed less frequently. The patient-recalled onset of psychiatric symptoms preceded onset of torticollis symptoms in 43.2% of those investigated.

Welding metallurgy's putative influence on Björk-Shiley convexo-concave valve outlet strut failures.

BACKGROUND AND AIM OF THE STUDY: Multiple reports of convexo-concave valve outlet strut fractures have focused on the welds, often implicating putative defects of uncertain character and significance. This study differs from all others in that it systematically assesses a large number (n = 60) of intact and fractured valves and clearly differentiates findings on the critical, tensile-stressed, inflow side of the outlet strut leg from those on the outflow side, which are subject only to compression. METHODS: Each valve was examined by scanning electron microscopy and subjected to multiple metallographic sectioning of each strut-flange interface. All fractures and selected intact valves were further analyzed with X-ray dispersive spectroscopy. RESULTS: Fatigue striations were seen in all fractured valves, and their orientation indicated that every fracture initiated in an area on the inflow side, spreading out progressively towards the outflow side. Data indicated that 22% of the first-to-fail leg separations and 17% of all fractures initiated outside of the weld. Element segregation areas were seen in 40% of welds, significantly more commonly in intact valves, invariably located on the outflow side, and typically (85%) apart from the fracture path. Microporosity was identified in 15% of welds, usually near the outflow side, and in the same proportion of intact and fractured valves. One fracture surface had a 38 microns, inflow-side void that might have been a factor in crack initiation in this valve, which was highly stressed. CONCLUSIONS: With this singular exception, no metallurgical feature of any weld was found that appeared to have contributed, even in a minor way, to the process of outlet fracture.

The 'oddball CNV' as an indicator of different information processing in patients with panic disorders.

In previous studies we found an inverse relationship between CNV amplitude and the probability of the occurrence of the warning stimulus (S1) in a cued reaction time task. The aim of the present study was to investigate this 'oddball effect' on CNV amplitude (Oddball CNV) in patients with anxiety disorders, since this effect describes the influence of event probability on reactive as well as proactive components of information processing. Patients suffering from panic disorders with or without agoraphobia and controls participated in a choice reaction time experiment. The subjects' task was to respond to flashes (S2s), cued 4 s in advance in random order by one of two easily distinguishable acoustic stimuli (S1a, S1b). In condition 1 the probability of S1a and S1b was 0.2 and 0.8, respectively, and in condition 2 0.5 for both S1s. The DC-EEG was recorded from F3, F4, C3, Cz, C4 and P3, linked mastoids as the reference. The data obtained confirm the oddball effect on the CNV amplitude, show clear deviations of patients in this effect, and also indicate remarkable differences in CNV shape between patients and controls. These observations are discussed as differences in information processing and information utilization.