Continuous capacitance-voltage spectroscopy mapping for scanning microwave microscopy.

A new method, scanning sawtooth capacitance spectroscopy (SSCS), is proposed to measure a map of capacitance/voltage curves (C-V) by applying a low frequency voltage sawtooth signal (20-100 Hz) to the AFM tip while scanning. For this a scanning microwave microscope (SMM) is used to acquire calibrated capacitance data in the high frequency range of 1-20 GHz. While the capacitance is acquired pixel by pixel, the applied voltage signal is recorded as well, and each pixel of the capacitance is assigned the corresponding voltage value. Assuming the voltage variable is smooth over time, adjacent pixels within a scan line will have similar voltage values and a small sequence of neighboring pixels can be combined into a virtual C-V spectroscopy curve. With standard SMM operation parameters roughly 26,000 C-V curves can be acquired within few minutes data acquisition time. The method is demonstrated for n-type and p-type silicon semiconductor samples and can be applied to other samples including new materials and bio-membranes.

Calibrated nanoscale capacitance measurements using a scanning microwave microscope.

A scanning microwave microscope (SMM) for spatially resolved capacitance measurements in the attofarad-to-femtofarad regime is presented. The system is based on the combination of an atomic force microscope (AFM) and a performance network analyzer (PNA). For the determination of absolute capacitance values from PNA reflection amplitudes, a calibration sample of conductive gold pads of various sizes on a SiO(2) staircase structure was used. The thickness of the dielectric SiO(2) staircase ranged from 10 to 200 nm. The quantitative capacitance values determined from the PNA reflection amplitude were compared to control measurements using an external capacitance bridge. Depending on the area of the gold top electrode and the SiO(2) step height, the corresponding capacitance values, as measured with the SMM, ranged from 0.1 to 22 fF at a noise level of ~2 aF and a relative accuracy of 20%. The sample capacitance could be modeled to a good degree as idealized parallel plates with the SiO(2) dielectric sandwiched in between. The cantilever/sample stray capacitance was measured by lifting the tip away from the surface. By bringing the AFM tip into direct contact with the SiO(2) staircase structure, the electrical footprint of the tip was determined, resulting in an effective tip radius of ~60 nm and a tip-sample capacitance of ~20 aF at the smallest dielectric thickness.

Experimental gastritis in mice enhances anxiety in a gender-related manner.

There is a gender-related comorbidity of pain-related and inflammatory bowel diseases with psychiatric diseases. Since the impact of experimental gastrointestinal inflammation on the emotional-affective behavior is little known, we examined whether experimental gastritis modifies anxiety, stress coping and circulating corticosterone in male and female Him:OF1 mice. Gastritis was induced by adding iodoacetamide (0.1%) to the drinking water for at least 7 days. Inflammation was assessed by gastric histology and myeloperoxidase activity, circulating corticosterone determined by enzyme immunoassay, anxiety-related behavior evaluated with the elevated plus maze and stress-induced hyperthermia tests, and depression-like behavior estimated with the tail suspension test. Iodoacetamide-induced gastritis was associated with gastric mucosal surface damage and an increase in gastric myeloperoxidase activity, this increase being significantly larger in female mice than in male mice. The rectal temperature of male mice treated with iodoacetamide was enhanced, whereas that of female mice was diminished. The circulating levels of corticosterone were reduced by 65% in female mice treated with iodoacetamide but did not significantly change in male mice. On the behavioral level, iodoacetamide treatment caused a decrease in nocturnal home-cage activity, drinking and feeding. While depression-related behavior remained unaltered following induction of gastritis, behavioral indices of anxiety were significantly enhanced in female but not male mice. There was no correlation between the estrous cycle and anxiety as well as circulating corticosterone. Radiotracer experiments revealed that iodoacetamide did not readily enter the brain, the blood-brain ratio being 20:1. Collectively, these data show that iodoacetamide treatment causes gastritis in a gender-related manner, its severity being significantly greater in female than in male mice. The induction of gastritis in female mice is associated with a reduction of circulating corticosterone and an enforcement of behavioral indices of anxiety. Gastric inflammation thus has a distinct gender-dependent influence on emotional-affective behavior and its neuroendocrine control.

Incidence of obsessive-compulsive phenomena in the course of acute schizophrenia and schizoaffective disorder.

Studies examining OC phenomena in schizophrenic and schizoaffective disorders have shown a prevalence of such phenomena in 1 to 60% of schizophrenic or schizoaffective patients. In this prospective study, about 10% of 150 male patients suffering from acute psychotic disorders (fulfilling DSM-IV criteria for Schizophrenia or Schizoaffective Disorder) were found to have OC symptoms. These symptoms showed no correlation to the type and severity of psychosis. As only 19% of the patients with obsessions and compulsions during acute psychosis showed an obsessive-compulsive personality disorder prior to their psychotic episodes, it may be concluded that there is no clear linkage between intrapsychotic OC phenomena and premorbid anancastic personality traits.

[Aggressive and suicidal behavior. A cluster analysis study of suicidal and nonclinical subjects]. / Aggressivität und suizidales Verhalten. Eine clusteranalytische Studie an Suizidenten und klinisch unauffälligen Vergleichspersonen.

AIMS: An attempt was made to examine the relationship between different dimensions of aggression and suicidal behavior in clinical and non-clinical subjects. METHOD: A clinical sample of 68 suicide attempters (39 females, 29 males) and a matched sample of 70 non-clinical subjects (38 females, 32 males) were subgrouped by cluster analytic techniques. Classification variables included the scales of the Aggressive Factors Questionnaire (AFQ). Discriminant function analyses were performed on the clusters to determine the quality of group separation and to assess the power of each input variable. External variables such as the amount of hopelessness, suicidal ideation and the number of suicide attempts were used to assess the clinical relevance of the identified clusters. RESULTS: Two subgroups were identified in each sample. Variables that contributed most to group separation were Auto-aggression/Depression and Spontaneous Aggression in the non-clinical sample and Excitability in the clinical sample, respectively. The clusters identified within the non-clinical sample differentiated between ideators and non-ideators. Cluster allocation within the clinical sample was indicative of the number of suicide attempts. CONCLUSIONS: Clusters defined on the basis of different dimensions of aggressiveness turned out to be a classification with significant implications for the assessment of suicidal behavior.

Increasing women's knowledge and satisfaction with cervical cancer screening.

In a randomized clinical trial, the efficacy of three interventions, designed to increase patient knowledge of cancer screening and satisfaction with preventive health care, were evaluated: verbal information; graphically supported information; information provided using video colposcopy; no standardized information (control condition). A sample of 147 healthy women were randomly assigned to the intervention group (IG) or the control group (CG). Pre- and post-test measures were obtained using a semi-structured interview, the State-Trait Anxiety Inventory and the Patient Satisfaction Tool. At pre-test, women had a low level of knowledge which increased significantly at post-test. The knowledge scores were slightly higher in women who received information supported by graphic or video colposcopy than in women who received standardized information without teaching aids. Compared to the CG, women in the IGs scored significantly higher on questions related to cervical cancer prevention. The level of satisfaction was significantly higher in women receiving video-supported information and graphic-supported information compared to women receiving information without teaching aids. The results indicated that visual teaching aids were effective: video colposcopy in increasing patient satisfaction with preventive health care; and graphic representation in improving knowledge regarding cancer screening. The combination of both should routinely accompany cervical cancer screening.

[Cardiovascular effects of active coping behavior in mental and social stress situations during various incentive conditions]. / Kardiovaskuläre Effekte aktiven Bewältigungsverhaltens in mentalen und sozialen Belastungssituationen unter verschiedenen Anreizbedingungen.

The main purpose of this study was to examine the cardiovascular effects of active coping behavior during mental and social challenge. Furthermore, the additional effects of monetary incentives were explored. A total of 80 normotensive male students of the ages 19 to 30 years served as subjects. Statistical analyses revealed strong task-specific effects on systolic (SBP) and diastolic blood pressure (DBP) as well as heart rate (HR). Compared to Mental Arithmetic and Preparing a Discussion Task, social challenges during Discussion lead to exaggerated increases in SBP (37.6 mmHg) and HR (26.1 bpm) coupled with intermediate elevations in DBP (18.0 mmHg). Monetary incentives were associated with enhanced HR reactivity. The intra-task correlation pattern showed a remarkable across-task stability of correlations between SBP and HR reactivity scores, with an apparent lack of significant correlations between SBP and DBP reactivity scores. Results of inter-task correlations supported the hypothesis of specific cardiovascular response patterns that might be indicative of different aspects of active coping with mental and social stress.

[Acne and free fatty acids in sebum, modification by doxycycline]. / Akne und freie Fettsäuren im Hauttalg, Beeinflussung durch Doxycyclin.

The severity of acne correlates with the quotient of triglycerides to free fatty acids in sebum. This quotient increases during systemic therapy with doxycycline, while the clinical picture of the disease improves.

[Augmentation of mandibular bone with hydroxylapatite--follow-up]. / Die absolute Kieferkammerhöhung mit Hydroxylapatit im Unterkiefer. Eine Nachuntersuchung.

A group of 31 patients whose mandibles had been augmented surgically with various methods using hydroxylapatite granules between 1984 and 1987, were followed-up to rate their subjective and objective masticatory function. The subjective assessment of the treatment result is comparable to the opinion given about vestibulo- and floor of the mouth-plasty. Masticatory function determined according to the method of fractionated sieving of the chewed food did not show any significant differences from the function measured in complete denture patients with strong alveolar bones. The need for regular follow-up is emphasized.

Different anisotropies of movement direction in upper and lower layers of the cat's area 18 and their implications for global optic flow processing.

Cells in Area 18 of awake and behaving cats were tested for directional preference with a large visual noise pattern. Upper and lower layer cells were found to exhibit different anisotropies for movement direction, offset by 90 degrees. These findings could reflect different functions for the global mapping and processing of optic flow field in upper and lower layers.

[Possibilities of psychological preparation for surgery in children and adults]. / Möglichkeiten der psychologischen Operationsvorbereitung bei Kindern und Erwachsenen.

Research in the field of behavioural medicine concerning psychological preparation for surgery is beginning to focus on practical issues. In the first study sixty children between the ages of 4 and 8 received the usual medical preparation from the hospital staff. In addition, the patients of two treatment groups were provided with relevant information by presenting a photographic peer model, or received emotional support by a psychologically trained supervisor. The second study was designed to assess the anxiolytic effects on preoperative state anxiety in 40 adult in-patients by implementing a systematic desensitization program. As a main result the findings demonstrated the sensitizing effects of psychological preparation for surgery both in children and adults. Contraindications and resulting practical issues are discussed.

[Proof of the effectiveness of a clotrimazole cream paste in acne vulgaris]. / Wirkungsnachweis einer Clotrimazol-Crèmepaste bei Acne vulgaris.

The efficacy of Clotrimazol cream paste containing a penetration enhancer in the treatment of acne vulgaris was objectified by investigating the sebum composition. Following treatment over three and six weeks, the ratio of triglyceride to free fatty acid significantly increased, which indicated an effective reduction of the lipase activity of Propionibacterium acnes within the sebaceous follicle.

Differences in direction specificity of receptive fields in upper and lower layers of the cat's prestriate area 18.

Direction specificity was measured for neurons in area 18 (A18) in penetrations approximately perpendicular to the layers in awake cats. A majority of lower layer cells (below 1.0 mm) preferred stimuli moving at rather orthogonal directions with respect to the preferred directions of the neurons in the upper layers (0-1.0 mm). The results suggest more functional autonomy of the corresponding cortical layers.