A practical method for identifying intermetallic phase particles in aluminium alloys by electron probe microanalysis

Aluminium alloys that contain Si, Mg, Fe, Mn and/or Cu usually contain one or more types of intermetallic phases that are not readily distinguishable in the microstructure by conventional microscopy methods. It has thus been a challenge to develop a method that will unambiguously identify them. A practical approach has been developed that is based on an inherent linear relationship revealed for the overall distribution of any two elements in a precipitate/matrix geometry and the first-order approximation of electron probe microanalysis (EPMA) results. Application of this approach to a direct chill cast 6082 alloy is demonstrated, and its major limitations are discussed.     

A logistic dose-ranging method for phase I clinical investigations trials

This paper describes an alternative to the continual reassessment method (CRM) for phase I trials. The logistic dose ranging strategy (LDRS) uses logistic regression and a dose allocation scheme similar to the CRM. It can easily be implemented from any logistic regression program. The LDRS can be a stand alone dose allocation scheme or it can be incorporated into standard three on a dose strategies to indicate when escalation can proceed more rapidly. Finally, the effect of covariates such as age or comorbid conditions on the toxicity expected for the dose selected for a phase II trial can be examined.     

Some technical improvements for the voltage clamp with the double sucrose gap

Ultraviolet radiation induces two photochemical alterations relevant to excitability in the nodal membranes: A selective blocking of the sodium permeability and a potential translation of the voltage dependent kinetic parameters of sodium inactivation and activation along the potential axis in the negative direction. The underlying processes are two different photoreactions, since 1) the action spectrum of the blocking effect shows a marked peak near 280 nm and rapidly decreasing sensitivity towards higher and lower wavelengths, while the action spectrum of the potential shift increase with lower wavelengths; 2) the blocking effect is enhanced by a more positive holding potential, while the potential shift is decreased; 3) the potential shift can be prevented intraaxonal application of l-cysteine or 2-mercaptoethanol, but the blocking effect is not affected.     

一种工程化的数字调相信号快速分类识别方法

在数字调制分类中,信号的相位周期特性会形成相位的卷叠并降低对接收到的射频信号的自动数字调制正确分类的概率.根据多进制数字相位调制(multiple-level phase shift keying,MPSK)信号的相位特征,通过相位去卷叠、根据最小均方误差原则去线性相位分量,以及相位的模π运算,提出了一种MPSK信号的分类方法.实验结果表明,基于相位特征的通信信号的自动调制分类算法具有很强的鲁棒性,对不同类型和滚降系数的脉冲成形滤波器和高码元速率都达到了较高的识别率.     

Monitoring of proteinuria in phase I studies in healthy male subjects

An extended analysis for loss of heterozygosity (LOH) on eight chromosomes was conducted in a series of 82 Wilms tumors. Observed rates of allele loss were: 9.5% (1p), 5% (4q), 6% (6p), 3% (7p), 9.8% (11q), 28% (11p15), 13.4% (16q), 8.8% (18p), and 13.8% (22q). Known regions of frequent allele loss on chromosome arms 1p, 11p15, and 16q were analyzed with a series of markers, but their size could not be narrowed down to smaller intervals, making any positional cloning effort difficult. In contrast to most previous studies, several tumors exhibited allele loss for multiple chromosomes, suggesting an important role for genome instability in a subset of tumors. Comparison with clinical data revealed a possible prognostic significance, especially for LOH on chromosome arms 11q and 22q with high frequencies of anaplastic tumors, tumor recurrence, and fatal outcome. Similarly, LOH 16q was associated with anaplastic and recurrent tumors. These markers may be helpful in the future for selecting high-risk tumors for modified therapeutic regimens.     

A practical method for identifying inoculants

The macrostructure of an ingot can be altered by controlling the fluid flow during solidification. Such control produces drastically different results depending on whether a solute addition acts as an inoculating agent (involving a low proportion of a nucleating second phase) or if it is mostly soluble and forms a second phase only as a result of microsegregation. This differentiation, previously shown for Al and some of its alloys, is repeated with magnesium containing zirconium, which is a known inoculant for Mg. Copper is then tested as an addition to lead. Its action allows the production of very curious macroscopic grain structures which will be shown to be characteristic of an inoculant. Subsequent tests support the validity of applying fluid flow structure-control as a method for identifying inoculants. Formerly with the Scientific Research Staff     

A method of objectively evaluating improvements in laparoscopic skills

BACKGROUND: In this paper, we explored a quick and inexpensive method to evaluate the improvement in laparoscopic skills gained by residents after attending a formal training course in laparoscopy. METHODS: Surgical residents attending an endoscopic workshop were randomly selected to perform tasks in a training simulator. Each was evaluated qualitatively and quantitatively before and after the workshop. A control group of six residents who did not attend the workshop were selected to perform the same tasks twice in succession. RESULTS: The total mean time improvement for all tasks in the study group was 34.3% and in the control group 7.3% (p = 0.0001). When the data was separated for each task, statistically significant improvement was demonstrated in five of the six tasks. CONCLUSIONS: Residents who attend a formal workshop in endoscopy can gain significant improvement in skills. The methods described in this study can be used to quantitatively measure this improvement throughout a resident's training.     

A practical method of autotransfusion in the emergency center

A new mobile autotransfusion device, modified for use in the Emergency Center, is described. Preliminary usage in thirty trauma patients who underwent autotransfusion of 60 units of blood indicated the device was simple to utilize, efficacious, inexpensive, cost-effective, and safe.     

Informed consent for phase I studies: evaluation of quantity and quality of information provided to patients

BACKGROUND: The process by which patients are informed and their consent is obtained in phase I trials has thus far been only marginally studied. Since 1986 we have followed an oral procedure, consisting of three consecutive conversations in which the investigator responsible for phase I studies, the research nurse and the patients' relatives and/or friends also participate, followed by the patients signing of a written consent form. It is required that six items of information considered essential by our staff be conveyed to patients by the responsible investigator. Meerwein's model, which defines three main dimensions of the informing process (the information itself, the emotional and interactive aspects), has been studied to ascertain whether it can be applied to evaluate the quality of the information proffered. METHODS: Thirty-two conversations were taped, transcribed and evaluated by one psychiatrist and one psychologist. A quantitative analysis of information was performed by calculating the number of patients to whom the essential items of information had been conveyed. The qualitative analysis was performed by rating on a five-point scoring system, from 1 (very bad) to 5 (excellent), the three dimensions of the informing process for each patient and by calculating for each dimension the mean score of the constituent items. RESULTS: Complete information about the characteristics of the phase I drug and the modalities of the treatment and follow up was given to almost 80% of the patients. All but one of the items of the information dimension scored 3.5 or higher, with the one related to the assessment by the doctor of the patient's understanding at the end of the consultation scoring less than 3 in 53% of the patients. All items of the emotional dimension scored higher than 3.5. Greater difficulty was encountered by the physician with the interactive dimension, the lowest mean scores being reported on the items related to the doctor's awareness of the indirectly expressed anxieties of the patients. In 71% of the consultations the three dimensions of information scored more than 3 and balanced one another, indicating a successful consultation by the Meerwein model. CONCLUSIONS: The informed consent procedure applied was satisfactory from a quantitative point of view, and the main items of information were acceptable to the patients. Meerweins's model proved to be applicable and useful for identifying pitfalls in communication. Greater attention should be paid to the indirect messages and implied criticisms of the patients to improve their participation in decision making. Physicians should become more skillful in providing adequate information and improve their methods of communication.     

A practical method of adjusting for risk in the prospective costs of capitated systems

Increasingly, providers of health services and medical groups are required to negotiate with managed care organizations and evaluate the adequacy of capitation rates. An intelligent assessment of the rate of payment requires an accurate projection of the costs per member per month that have been adjusted for the risk present in the insured population. This article develops a practical model for incorporating risk in forecasts of the full cost per member per month.     

Approximately optimal designs for phase II clinical studies

There is no consensus on determination of sample size in phase II clinical trials. The use of Bayesian decision theory has been proposed by Stallard (1), among others. In this article, optimal three-stage designs are obtained using decision theory. These are compared with procedures proposed by Schoenfeld (2), Ensign et al. (3), and Chen et al. (4) and the sequential probability ratio test of Wald (5) and Barnard (6). The three-stage procedures are shown to be close to the true optimal test; the sequential probability ratio test is easier to obtain and only marginally inferior. Because optimality of the decision-theory approach depends on accurate specification of costs and profits, an assessment is made of the sensitivity of the proposed procedures to a range of gain function parameter values.     

Getting the mail questionnaire returned: Some practical research considerations.

Tested the effectiveness of 3 methods most often used for returned mail questionnaires, in terms of the rate of return and respondent bias in each method. 100 managers received a questionnaire which was to be returned by either a stamped envelope, a business reply envelope, or their firm's interplant mail system. The interplant mail system provided the greatest return rate, at lowest cost, without respondent bias. The business reply envelope produced a very poor response rate. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Informed consent in phase I trial

The three-dimensional structure of a complex of cinnamycin, a 19-amino acid residue immunopotentiator peptide, and lysophosphatidylethanolamine was determined by 1H-NMR. The complex was cylindrical in shape, 11 A in diameter and 26 A in length, excluding the acyl chain of the phospholipid. The peptide had a hydrophobic pocket surrounded by residues Phe-7 through Ala(S)-14 to bind to the head group of the ligand. Fitting of the head group to the hydrophobic pocket was so good that other than a glycerophosphoethanolamine head group would be unable to fit the pocket. The goodness of the fitting is compatible with the strict specificity of ligand binding of the peptide.     

Generalized enthalpy method for multicomponent phase change

Phase change problems with coupled transport of heat and species occur in solidification and other fields of materials processing. This article describes a new formulation for numerical modeling of coupled phase transformation. The technique is an extension of the conventional heat diffusion enthalpy method and uses the control volume approach. Numerical time-steps are separated into a transport section which updates extensive molar quantities from flux expressions and balance equations, and a thermodynamic section which computes intensive quantities from state functions through local entropy maximization. Heat and species transport are handled in a symmetrical manner with flux expressions from irreversible thermodynamics. The scheme is general enough to cover an unrestricted number of species and phases in various systems and is appropriate for three-dimensional modeling. Applications of the algorithm are illustrated by computations on isomorphous, eutectic, and peritectic binary systems; a simplified dendritic growth problem with coupled heat and species transport is also presented.