Thin films alloys of Pd and Ni make good sensors for H partial pressures (p H sub 2 ) over a very wide range: from 10 exp )3 to 700 Torr. For pH sub 2 from 1-700 Torr the atomic percent of Ni in the ...alloy has a strong effect on the change in film resistance which is used as the sensing property. The phase transition from the alpha - to the hydride beta -phase must be avoided to maintain a reversible sensor. The characteristics of alloys with Ni of 3, 5.3, 8 and 15% are reported. The phase transition was found in the 5.3% alloy at approx25o Torr, but alloys of Ni > 8% showed no phase change behaviour up to 630 Torr (pure H sub 2 ) at ambient temperatures. Other characteristics of the Pd/Ni alloy sensors are also reported, including the effect of temperature, oxygen, and relative humidity, and the speed of response to step changes in p H sub 2 .
A two-phase study was conducted on the relationship between organizational climate variables and burnout among personnel in a multifunction community service agency. Initial interviews with a small ...pilot sample identified major sources of stress, which were then incorporated into a second-phase questionnaire to all staff. Multiple regression analyses illustrated that perceived interactions between head office administrators and sections of the agency contributed significantly to emotional exhaustion, whereas perceptions of within-section interactions and involvement in decision-making had a positive impact on personal accomplishment. Perceived communication levels, however, were negatively related to personal accomplishment. The findings suggest the importance of organizational variables and highlight strategies for burnout reduction and effective stress management in human service organizations.
After 10 years, loosening of total joint endoprostheses occurs in about 3 to 10 percent of all patients, requiring elaborate revision surgery. A periprosthetic membrane is routinely found between ...bone and loosened prosthesis. Further histomorphological examination allows determination of the etiology of the loosening process. Aim of this study is the introduction of clearly defined histopathological criteria for a standardized evaluation of the periprosthetic membrane. Based on histomorphological criteria and polarized light microscopy, four types of the periprosthetic membrane were defined: periprosthetic membrane of wear particle type (type I), periprosthetic membrane of infectious type (type II), periprosthetic membrane of combined type (type III), periprosthetic membrane of indifferent type (type IV). Periprosthetic membranes of 268 patients were analyzed according to the defined criteria. The correlation between histopathological and microbiological diagnosis was high (89%, p<0,001), the inter-observer reproducibility was sufficient (95%). This classification system enables a standardized diagnostic procedure and therefore is a basis for further studies concerning the etiology of and pathogenesis of prosthesis loosening.
In multiple trauma patients successful treatment of femur shaft fractures depends more on timing of osteosynthesis than on choosing a specific type of fracture stabilization. Because of theoretical ...and practical reasons early osteosynthesis within 24 to 48 hours seems to be advantageous. In our experience it led to a significant decrease in complications. However, concomitant thorax trauma mandates special consideration. The two fatalities in our study belonged to this subgroup. With adequate indication for therapeutic intervention, correct operative technique and consideration of the patient's general status good results can be expected with every type of fracture treatment available (external fixation, plate fixation, intramedullary nailing).
Although the clinical picture of an acute rupture of the Achilles tendon is clear, it remains unrecognized or falsely evaluated in up to 10% of all cases. Wrong management without surgical ...intervention or adequate immobilization frequently leads to unstable scar tissue, requiring completely different therapy and rehabilitation than in the case of an acute injury. Between 6/2000 and 3/2002 11 patients (average age 53 years, M:F=9:2) with a neglected rupture of the Achilles tendon undergoing reconstruction of unstable scar tissue were evaluated in a prospective study. The preoperative cardinal symptoms were loss of strength and stress pain. The length of the unstable scar tissue measured 3.5 cm on average (2.0-6.0 cm). After resection of the scar lesion, a broad central gastrocnemius aponeurotic flap was performed in nine cases,whereas two cases underwent a central tendon shift. As a result of the surgical tendon reconstruction,we noted a 40% mean increase of strength in the final examination. This improvement was associated with less pain and a comparable range of motion. Protracted wound secretion and superficial wound necrosis were recorded on one and two occasions, respectively. Ultrasound and X-ray as preoperative imaging diagnostic tools in addition to the clinical picture appear to be sufficient for proper indication and planning of surgical intervention. The broad central aponeurotic flap has proven to be the most successful method in our patients. In cases of a short distal end, the "grip-box plasty" with a central tendon shift is indicated. Even lesions up to 6 cm can thus be repaired with autologous tissue.
The centrally acting alpha 2-adrenoceptor agonist clonidine was used to assess the sensitivity of alpha 2-adrenergic neurotransmission in man, using receptor-binding studies and clonidine-induced ...growth hormone response. Neither acute (2 micrograms/kg body weight) nor subchronic (3 days, 2 x 150 micrograms/kg body weight) administration of clonidine affected platelet alpha 2-adrenoceptor number in humans as judged by 3H-yohimbine and 3H-UK-14,304 binding. The same treatment also did not modify central postsynaptic alpha 2-adrenoceptor function in the same individuals as assessed by clonidine-induced growth hormone responses. Similarly, subchronic (3 days, 500 micrograms/kg body weight, i.p.) or chronic (14 days, 500 micrograms/kg, i.p.) administration of clonidine to mice failed to change 3H-yohimbine or 3H-UK-14,304 binding sites in membranes prepared from frontal cortex. On the other hand, in vitro experiments using mouse frontal cortex or human platelet membranes showed pronounced reduction of 3H-UK-14,304 but not of 3H-yohimbine binding sites after incubation with several adrenoceptor agonists. The data indicate that acute and subchronic clonidine treatment may not change alpha 2-adrenoceptor sensitivity in humans or mice as assessed both at the functional and receptor level.
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