Poly(arylene-1,2,4-oxadiazole)s (PAOs) bearing flexible, linear side chains, 3a - c , were prepared by solution cyclodehydration of their precursors, poly(arylene acyloylamide oxime)s (PAAs), 2a - c , which were synthesized by solution polycondensation of 2,5-bis(n-alkoxymethyl)-terephthaldiamide oximes (DIS-TADO), 1a - c , with terephthaloyl dichloride (TPC). The length of the n-alkoxy group was varied from methoxy via butoxy to octyloxy. The reduction of the phase transition temperatures and the enhancement of the solubilities of 3a - c were greatly affected by the length of the side chains. PAOs with longer side chains, 3b and 3c , are nematic type liquid-crystalline polymers. 相似文献
Physician geographic maldistribution is a problem in the United States health care system. Innovative strategies are needed to entice resident family physicians training in the larger, more numerous suburban and urban training programs to practice in rural areas upon completing their training. This paper describes a strategy used at St. Elizabeth Medical Center Family Practice Residency Program, Dayton, OH, to encourage rural practice. In the St. Elizabeth plan, the interested family practice resident moonlights in a rural practice provided by the local county hospital. The county medical staff covers the resident physician's practice during the frequent absences. The residency program faculty provide on-site supervision, telephone back-up coverage, and practice consultation. The county hospital provides billing services; the resident physician retains 100 percent of collections. The resident physician gains exposure to the knowledge, skills, and attitudes needed in rural practice. Upon completion of residency training, the physician remains in practice and is not required to pay back any expenses incurred by the hospital. Two resident physicians participate currently; three others have expressed interest in practicing in the community. A similar plan might work in parts of the United States where, like Ohio, training programs and rural communities are not far apart. 相似文献
Background: The Na sup + channel is voltage gated and characterized by three distinct states: closed, open, and inactivated. To identify the effects of halothane on the cardiac Na sup + current (INa) at various membrane potentials, the effects of 1.2 mm halothane at different holding potentials (VH) on INa were examined in single, enzymatically isolated guinea pig ventricular myocytes.
Methods: The INa was recorded using the whole-cell configuration of the patch-clamp technique. Currents were generated from resting VH s of -110, -80, or -65 mV. State-dependent block was characterized by monitoring frequency dependence, tonic block, and removal of inactivation by veratridine.
Results: Halothane produced significant (P < 0.05) VH -dependent depressions of peak INa (mean +/- SEM): 24.4 +/- 4.1% (VH = -110 mV), 42.1 +/- 3.4% (VH = -80 mV), and 75.2 +/- 1.5% (VH = -65 mV). Recovery from inactivation was significantly increased when cells were held at -80 mV (control, tau = 6.0 +/- 0.3 ms; halothane, tau = 7.1 +/- 0.4 ms), but not at -110 mV. When using a VH of -80 mV, halothane exhibited a use-dependent block, with block of INa increasing from 8.6 +/- 1.4% to 30.7 +/- 3.5% at test pulse rates of 2 and 11 Hz, respectively. Use-dependent inhibition was not apparent at VH of -110 mV. When inactivation of INa was removed by exposure to 100 micro Meter veratridine, no significant difference was observed in the depressant effect of halothane at both VH s: 26.6 +/- 4.5% (VH = -80 mV) and 26.4 +/- 5.6% (VH = -110 mV). 相似文献
A tissue equivalent phantom was used in the study and absored x-ray doses.It measuring for some important organs of head and neck by four routive sialography methods (panoramic conventional x-ray radioagraphy,tomography,fluoroscope,CT) and also the X-ray absorbed doses of thyroid and len when lead containing loop and spectacles of head containing glass were used for prevention.All the data were processed statistically and a compartive study of absorbed x-ray doses of four sialography methods:Doses of submandibular gland were higher in CT,tomography and fluoroscope among them,CT was the highest indicating that it was superior to other methods for accurately locating that it was superior to other methods for accurately locating the within-gland tumor.Fluoroscope will be use more frequently in clinic,because it can observe the living gland panoramic and normal radiography can be used routinely because they had the minimum doses in measured organs.2.The absorbed x-ray doses of len and thyroid decreased by 93%-% when prevention was taken in CT or fluoroscope,65%-85% doses was decreased in normal radiography or panoramic with prevention. 相似文献
Abstract We investigated factors correlated with abnormal behavior in the elderly residing in a special nursing home (group A) and a psychiatric hospital (group B) using the dementia behavior disturbance scale, the mini mental state examination, the Japanese version of the Philadelphia Geriatric Center morale scale, and the ADL assessment scale. The cognitive function of group B was decreased compared with that of group A, but most activities of daily living (ADL) in the latter group were disrupted compared with those in the former. Only a few categories of ADL correlated with abnormal behavior in group A, whereas cognitive function, quality of life, and most categories of ADL correlated with abnormal behavior in group B. These results suggest that factors correlated with abnormal behavior in the elderly differ within institutions of medical and social welfare systems. 相似文献