A critical analysis of attenuation effects of different types of ear protective devices

The present study was undertaken to evaluate the noise attenuation characteristics of different types of Ear protective Devices which are commonly used. 20 healthy normal subjects’ open and closed hearing thresholds (with the usage of ear protective device) were recorded in an anechoic chamber and the attenuation charactaristics at 8 discrete frequencies were analysed and compared. Though the attenuation given by different types of ear protective devices are variable and not the ideal, still the present generation of devices have shown satisfactory attenuation characteristics, It is important that proper selection, fitment and usage of these devices should he carefully thought of prior to its usage.     

牛膝多糖的化学研究

我国传统的中草药牛膝经沸水提取,去游离蛋白质,透析,沉淀,依次进行Cellex D和Sephadex G-150柱层析,得到有免疫活性的肽多糖ABAB,分子量2.3×10⁴。是由D-葡萄糖酸,D-半乳糖,D-半乳糖酸,L-阿拉伯糖和L-鼠李糖组成,摩尔比为12:2:3:1:1。经羧基还原,甲基化反应,过碘酸盐氧化,Smith降解,IR分析,证明它有(1→4)-D-葡萄糖酸和(1→4)-D-半乳糖酸残基组成的主链。ABAB中肽的含量为24.7%,主要有甘氨酸,谷氨酸,门冬氨酸和丝氨酸组成。     

The doctor-nurse relationship: an historical perspective

The purpose of this historical research was to explore the evolution of the doctor-nurse relationship. Specifically, older nurses were interviewed regarding their nursing interactions with physicians approximately 50 years ago. A grounded theory approach was employed to analyse the data. Inherent to the difficulties nurses experienced was the dominant power position assumed by doctors in the health profession. The data give added insights into the development of this relationship. It was found that because nurses were educated primarily by doctors and because they were hired by doctors if they were considered to be 'good' nurses, a sex role stereotype of the nurse emerged. Historically these roles have influenced and continued to influence the nursing profession.     

Identification of monoclonal antibodies that inhibit the function of protein C inhibitor. Evidence for heparin-independent inhibition of activated protein C in plasma

Monoclonal antibodies specific for protein C inhibitor (PCI) partially blocked the inactivation of activated protein C (APC) in plasma, whereas in a purified system, the PCI activity could be completely blocked. The inactivation of APC in normal and in PCI-depleted plasma was similar in the absence of heparin. The addition of heparin did not change the rate of inactivation of APC in PCI-depleted plasma, whereas in normal plasma a rapid phase of inhibition of APC was followed by a slower phase of inhibition. The slower phase was identical to the rate of inhibition of APC in the absence of heparin. After incubation of normal plasma with a monoclonal antibody specific for PCI that blocked its activity, there was no difference in heparin-dependent or heparin- independent inhibition of APC. These results indicate that in the absence of heparin PCI is unable to inactivate APC in a plasma environment.     

Amphetamine actions on pre- and postpubertal rat hippocampal dentate granule neurons

Clinical evidence suggests different actions of amphetamine (AMPH) in children and adults. Using intracellular recording techniques, the actions of AMPH at 10 and 40 microM were investigated in granule neurons of hippocampal slices from pre- and postpubertal rats. AMPH (10-40 microM) caused depolarization of most postpubertal neurons, often with increased spontaneous activity, whereas most prepubertal neurons were hyperpolarized. In both age groups, AMPH caused increased neuronal excitability by reducing spike threshold, attenuating the postspike train afterhyperpolarization, reducing spike frequency adaptation, and potentiating excitatory postsynaptic potentials. Changes in cell input resistance were variable and Ca2+ currents were unaffected. AMPH actions took 10-15 min to appear and became maximal 30-55 min after application. The effects were reversible at 10 microM, but at 40 microM, prolonged washout for up to 2 h did not completely reverse these actions. The beta-adrenergic blocker, propranolol, partially blocked AMPH actions. The dopamine (D2) blocker, haloperidol, did not block AMPH actions. Mature neurons were also tested with 2.5 microM AMPH showing similar but more reversible effects as the higher concentrations. Depleting catecholamines by reserpine partly attenuated the effects of 40 microM AMPH in mature neurons. Perfusion of neurons with 10 and 20 microM cocaine did not produce effects similar to those of AMPH. It is suggested that AMPH produces its effects on granule neurons only in part through the release of norepinephrine. The involvement of other neurotransmitters and/or neuromodulators released by AMPH, or direct postsynaptic actions of AMPH are also possible.     

Small lymphocytic lymphoma: a clinicopathologic analysis of 268 cases

We analyzed specimens from 268 patients with small lymphocytic lymphoma (SL) to identify prognostic factors significant for survival. These patients were staged and treated according to the protocols of the Cancer and Leukemia Group B, Eastern Cooperative Oncology Group, Southeastern Cancer Study Group, and the Southwest Oncology Group. Univariate analysis showed that a large-cell grade greater than I, WBC greater than 10,000/microL, hemoglobin (Hgb) less than 11 g/dL, age greater than or equal to 55 years, and failure to respond to treatment were all poor prognostic factors. Multivariate analysis showed that large-cell grade, age, degree of capsular invasion, and symptom type were independently associated with survival. Separate analyses of cases with and without leukocytosis indicated differences in survival. In patients without leukocytosis, age, presence or absence of anemia, and treatment response were significant prognostic variables; in patients with leukocytosis, large-cell grade, presence or absence of anemia, symptom type, and treatment response were significantly related to survival. Multivariate analysis showed that age was the only significant independent prognostic variable in patients without leukocytosis; in patients with leukocytosis, symptom type, large-cell grade, and bone marrow involvement were independently associated with survival. We conclude that several parameters, both clinical and pathologic, should be assessed at the initial diagnosis of SL to predict prognosis better.     

Caring and nursing: a dilemma

The history of caring is intertwined with the history of women and thus with nursing Although nurses have a professional mandate to provide care, the significance, meaning and function of care and caring remains undefined and intangible within nursing Many factors contribute to a dilemma that requires the professional responsibility to care while withholding recognition from those who provide such care Caring is often hailed as the hallmark of nursing This paper considers some of the questions and permutations related to the concept of caring in nursing     

A model to guide development and application of multiple nursing theories

Over the past decade there has been an explosion of interest and activity in the nursing profession directed toward the development of a theory base for nursing education and practice. Although we support the overall thrust of nursing theory development, we have concerns about its utility, scope and stated purposes. We are especially sensitive to the plight of the practising nurse who might attempt to use the current nursing theories to guide and explain choices made in daily practice. In this paper we examine current use of the word 'theory' and describe problems inherent in nursing's efforts to apply educationally derived conceptual frameworks to nursing practice. We identify a need for the development and use of many theories for nursing and argue that there is a logical need for a 'meta-model' which will guide the use of multiple theories in practice. A model is presented which allows the practising nurse to examine the various theories in terms of their applicability to a given client situation. We believe the model is also useful to nurse educators and researchers who may be attempting to use nursing theories for educational purposes or develop nursing's knowledge base through empirical work.