Ternary digital systems

In view of recent developments in large-scale, complex digital systems, it is of interest to broaden the study of two-leveled logical systems to the study of three-leveled systems. This paper introduces the ternary logic system and develops a design approach for ternary digital systems that is based on familiar binary techniques. Ternary number systems are introduced and two base-conversion algorithms are given: one for integral numbers and the other for fractional numbers. Ternary arithmetic is similar to binary arithmetic or to decimal arithmetic. Four algebraic operations, Cycling, Negation, And, and Or, are then defined and the algebra is systematically developed through postulates and theorems. The algebraic method of minimization is difficult for a large number of variables or terms, and the map method is impracticable for more than three variables. Hence a programmable minimization method is developed by analogy with the Quine-McCluskey method for binary minimization. Diode-transistor schemes of circuit realization are presented. In these, the idea is to use p-n-p and n-p-n transistor pairs to provide the three different voltage levels desired. Tristable devices using three Cycling-gates are also described. A core storage element employs two differently oriented cores and provides one ternary digit of storage. Additional algebraic operations that are used in the current literature are given in the Appendix

Cellular synthesis of synchronous sequential machines

With the advancing solid-state technology, it is necessary to develop new techniques for synthesizing digital networks. The regular pattern of cellular circuits seems to be the best fitted for the new LSI technology. Recently, cellular implementations of comibinational circuits have received considerable attention but very little attention has been given to sequential circuits. In this paper, we present two new methods for realizing sequential machines, both using cellular circuits. These new techniques will also enable us to do away with the time-consuming and difficult problem of state assignment. State-assigned (Moore) machines are assumed throughout. The first method converts sequential functions into combinational like equations. In order to do so, the machine must be either definite or finite input and feedback memory (FIFM). If the machine is neither definite nor FIFM, it is made FIFM by constructing a proper feedback function. These combinational like equations can easily be implemented by conventional combinational cellular circuits, such as the cutpoint cellular arrays, together with delay elements. The second method utilizes matrix methods. It is noted that when a machine is in a certain state and is subject to an input, it does two things: it makes a state transition and it produces outputs. If the diagonal elements of an nxn array of cells are thought as representing n states, the transition of states can be accomplished by first moving horizontally and then vertically and the output can be collected by an added bottom collection row. In both cases, bounds on the number of cells are established and minimal realizations are studied. Methods for starting these cellular machines are also investigated. In order to make the machine more flexible, techniques are devised to initialize the machine into any state desired. It is safe to predict that future computing systems will continue to increase the demands on several sophisticated design areas. They will need to be more readily expandable and modifiable. Automatic error detection and correction will also play a more significant role. Therefore, besides modularity, reliability and programmability are also important aspects of any new design techniques. Both synthesis methods presented in this paper can easily be modified to include these features

Comparison of admission random glucose, fasting glucose, and glycated hemoglobin in predicting the neurological outcome of acute ischemic stroke: a retrospective study

Background Hyperglycemia is a known predictor of negative outcomes in stroke. Several glycemic measures, including admission random glucose, fasting glucose, and glycated hemoglobin (HbA1c), have been associated with bad neurological outcomes in acute ischemic stroke, particularly in nondiabetic patients. However, the predictive power of these glycemic measures is yet to be investigated. Methods This retrospective study enrolled 484 patients with acute ischemic stroke from January 2009 to March 2013, and complete records of initial stroke severity, neurological outcomes at three months, and glycemic measures were evaluated. We examined the predictive power of admission random glucose, fasting glucose, and HbA1c for neurological outcomes in acute ischemic stroke. Furthermore, subgroup analyses of nondiabetic patients and patients with diabetes were performed separately. Results Receiver operating characteristic (ROC) analysis revealed that admission random glucose and fasting glucose were significant predictors of poor neurological outcomes, whereas HbA1c was not (areas under the ROC curve (AUCs): admission random glucose = 0.564, p = 0.026; fasting glucose = 0.598, p = 0.001; HbA1c = 0.510, p = 0.742). Subgroup analyses of nondiabetic patients and those with diabetes revealed that only fasting glucose predicts neurological outcomes in patients with diabetes, and the AUCs of these three glycemic measures did not differ between the two groups. A multivariate logistic regression analysis of the study patients indicated that only age, initial stroke severity, and fasting glucose were independent predictors of poor neurological outcomes, whereas admission random glucose and HbA1c were not (adjusted odds ratio: admission random glucose = 1.002, p = 0.228; fasting glucose = 1.005, p = 0.039; HbA1c = 1.160, p = 0.076). Furthermore, subgroup multivariate logistic regression analyses of nondiabetic patients and those with diabetes indicated that none of the three glycemic measures were associated with poor neurological outcomes. Discussion Fasting glucose is an independent predictor of poor neurological outcomes in patients with acute ischemic stroke and had greater predictive power than that of admission random glucose and HbA1c. The predictive power of glycemic measures for poor neurological outcomes did not differ significantly between the nondiabetic patients and those with diabetes

8-Alkylcoumarins from the Fruits of Cnidium monnieri Protect against Hydrogen Peroxide Induced Oxidative Stress Damage

Three new 8-alkylcoumarins, 7-O-methylphellodenol-B (1), 7-methoxy-8-(3-methyl- 2,3-epoxy-1-oxobutyl)chromen-2-one (2), and 3'-O-methylvaginol (3), together with seven known compounds (4–10) were isolated from the fruits of Cnidium monnieri. Their structures were determined by detailed analysis of spectroscopic data and comparison with the data of known analogues. All the isolates were evaluated the cytoprotective activity by MTS cell proliferation assay and the results showed that all the three new 8-alkylcoumarins exhibited cytoprotective effect on Neuro-2a neuroblastoma cells injured by hydrogen peroxide