Variation of ionic conductivity in a plastic-crystalline mixture.

Ionically conducting plastic crystals (PCs) are possible candidates for solid-state electrolytes in energy-storage devices. Interestingly, the admixture of larger molecules to the most prominent molecular PC electrolyte, succinonitrile, was shown to drastically enhance its ionic conductivity. Therefore, binary mixtures seem to be a promising way to tune the conductivity of such solid-state electrolytes. However, to elucidate the general mechanisms of ionic charge transport in plastic crystals and the influence of mixing, a much broader database is needed. In the present work, we investigate mixtures of two well-known plastic-crystalline systems, cyclohexanol and cyclooctanol, to which 1 mol. % of Li ions were added. Applying differential scanning calorimetry and dielectric spectroscopy, we present a thorough investigation of the phase behavior and the ionic and dipolar dynamics of this system. All mixtures reveal plastic-crystalline phases with corresponding orientational glass-transitions. Moreover, their conductivity seems to be dominated by the "revolving-door" mechanism, implying a close coupling between the ionic translational and the molecular reorientational dynamics of the surrounding plastic-crystalline matrix. In contrast to succinonitrile-based mixtures, there is no strong variation of this coupling with the mixing ratio.

Comparison of auto-fluorescence and tetracycline fluorescence for guided bone surgery of medication-related osteonecrosis of the jaw: a randomized controlled feasibility study.

Recent studies have indicated that bone shows auto-fluorescence under an appropriate fluorescence lamp. The aim of this preliminary study was to compare the success rates of the established tetracycline fluorescence-guided bone surgery with auto-fluorescence-guided bone surgery in the treatment of medication-related osteonecrosis of the jaw (MRONJ). Forty patients suffering from MRONJ were referred for surgical treatment and were divided randomly into two groups: auto-fluorescence (n=20) or tetracycline fluorescence (n=20) guided bone surgery. The primary endpoint was treatment success, defined as the absence of exposed bone at 8 weeks after surgery. Secondary outcomes assessed were mucosal integrity, signs of infection, pain, and loss of sensitivity; these were evaluated descriptively at 10 days, 8 weeks, 6 months, and 1 year after surgery. At 8 weeks postoperative, 18/20 patients (90%) in the auto-fluorescence group and 17/20 patients (85%) in the tetracycline fluorescence group showed mucosal integrity (P>0.05). At the last follow-up, 94% in the auto-fluorescence group and 89% in the tetracycline fluorescence group presented complete mucosal coverage with no exposed bone, infection, or pain (P>0.05). There was no significant difference between the two techniques for any of the secondary outcomes (P>0.05). The results of this preliminary study show that auto-fluorescence-guided bone surgery has comparable success rates to the established tetracycline fluorescence-guided bone surgery.

[Multimodal group therapy for the elderly with chronic pain: concept and results in a before and after comparison]. / Multimodale Gruppentherapie bei Senioren mit chronischen Schmerzen : Konzept und Ergebnisse im Prä-post-Vergleich.

BACKGROUND: Multimodal pain therapy programs are increasingly being recommended as an effective treatment option also for elderly patients with chronic pain. However, data from Germany are limited. PATIENTS AND METHODS: A multimodal group program adapted to the specific needs of elderly pain patients over 70 years old (20 treatment days, over 10 weeks) was started in our pain clinic in June 2005. We evaluated clinical, psychometric and physical data at the beginning and at the end of the treatment program, and compared outcome results with a waiting list control group. RESULTS: A total of 24 patients (mean age 76.2+/-4.79 years) could be evaluated of which 21 patients suffered from musculoskeletal pain, 2 from neuropathic pain syndromes and 1 from headache. In the waiting-list control group 13 patients were included. There were no significant between-group differences regarding age, stages of chronification, pain intensity, duration of pain and pain diagnosis. CONCLUSIONS: A multimodal pain therapy program for elderly patients (over 70 years old) is an effective treatment option to reduce pain intensity and pain disability. Furthermore, life quality and physical performance improved. Long-term effects still have to be evaluated.

[Monitoring of patient-controlled analgesia by the nursing staff]. / Uberwachung der patientenkontrollierten Analgesie (PCA) durch den Pflegedienst auf Allgemeinstationen.

OBJECTIVE: Patient-controlled analgesia (PCA) is employed successfully on surgical wards. Continuous monitoring is important for the safety of the patient and the efficiency of this form of pain therapy. In the study we evaluated the regularity and completeness of monitoring data which had been collected by the nursing staff on the surgical wards. METHODS: Data on pain intensity, vital signs, and side effects were collected. Additionally, in the case of epidural analgesia, sensory and motor function were tested. In the first four hours after starting the PCA-pump, the nursing staff was instructed to document this data hourly (phase I), followed by a two hour interval until 8 am the next day (phase II). In general, monitoring was continued every four hours up to the discontinuation of the PCA; whereas in our study only forty hours (10 measurements) were included (phase III). Documentation protocols of 637 patients were evaluated and tested for the completeness of the data. RESULTS: In phase I, the data of 128 patients (20%) were complete. In 173 patients (27%) less than 50% of the data were documented. During phase II, only in 98 patients (15%) the data collection was complete. In 237 patients (37%) less than 50% of the measurements were determined. In phase III, in 205 patients (32%) all measurements, and in 104 patients (16%) less than 50% of the measurements were documented. CONCLUSION: Complications during PCA become manifest mainly during the first hours after starting the PCA-pump. Especially during these phases, documentation was found to be quite poor. This underlines the importance of an intense cooperation between acute-pain service and nursing staff with periodical training of the staff.

Sodium space and intravascular volume: dietary sodium effects in cystic fibrosis and healthy adolescent subjects.

OBJECTIVE: To assess the physiologic response to salt depletion in subjects with cystic fibrosis (CF) and control male adolescents for sodium balance, sodium space, and stimulation of the renin-angiotensin-aldosterone axis. DESIGN: Seven subjects with CF and six controls received a salt-replete (150 or 290 mmol NaCl per day) diet and then a salt-deplete (10 mmol NaCl per day) diet while in a clinical research center. RESULTS: Space maintenance: CF subjects responded to salt depletion with a greater weight loss than did controls (1.9 vs 0.8 kg) and a decrease in 24Na+ space, whereas controls maintained 24Na+ space. Paired (Na-deplete/Na-replete) blood volumes decreased in subjects with CF, but not in controls. Renin-angiotensin-aldosterone axis stimulation: During salt repletion, subjects with CF had significantly higher aldosterone values than did controls in the afternoon, but not at 7:00 AM. During salt depletion, plasma renin activity and aldosterone increased significantly more in subjects with CF than in controls (renin, 35 vs 13 ng/mL/hour [9.7 vs 3.6 ng.L-1 s-1]; aldosterone: 181 vs 101 ng/dL [5021 vs 2802 pmol/L]). Furthermore, the angiotensin antagonist saralasin increased renin much more in subjects with CF (154 vs 36 ng/mL per hour [43 vs 10 ng.L-1 s-1]). Vasomotor functions: Mean arterial pressure was decreased in subjects with CF on both diets and decreased significantly more with low salt only in subjects with CF. During salt depletion, subjects with CF showed enhanced orthostatic tolerance (less heart rate increase with standing) compared with controls, thus obscuring their volume loss. The blood pressure response to an acute infusion of saralasin suggested that in salt-replete subjects with CF, but not in controls, angiotensin receptors were functional in maintaining vascular tone. During salt depletion, angiotensin was more important for maintenance of blood pressure in subjects with CF than in controls, because the saralasin-induced drop in blood pressure was 20%, ie, close to shock levels, in subjects with CF, and only 6% in controls. CONCLUSION: The data suggest that patients with CF are so successful in compensating for volume depletion by vigorous activation of the renin-angiotensin system that salt depletion/dehydration cannot be recognized easily by routine clinical measurements, eg, capillary refill, serum sodium levels, or tachycardia.

Psychological impact of home apnea monitoring: temporal effects, family resources, and maternal coping style.

Mothers of 30 infants who had experienced an emergency apnea episode and were placed on a home apnea monitor were studied longitudinally, using measures of mood disturbance (anxiety, depression, hostility, fatigue, vigor and confusion). Mothers were assessed at the time of hospitalization immediately following the apnea episode, after approximately one month of home monitoring, and after three months of home monitoring. Measures of family resources, health locus of control, and coping style, involving preference for information under situations of threat, were obtained as predictor variables. A high level of mood disturbance was seen initially, but this was transient, diminishing significantly after the first month of monitoring. Level of family resources was highly predictive of mood disturbance throughout the study period, while health locus of control beliefs were predictive of changes in mood disturbance over time. These findings suggest a means for identifying families at higher risk for maladaptive responses, and in need of more intensive psychosocial support.