Rating instruments

Rated instrument limit primary current Rated primary current... 

Once the selectivity is optimized, a system optimization can be performed to Improve resolution or to minimize the separation time. Unlike selectivity optimization, system cqptimization is usually highly predictable, since only kinetic parameters are generally considered (see section 1.7). Typical experimental variables include column length, particle size, flow rate, instrument configuration, sample injection size, etc. Hany of these parameters can be. Interrelated mathematically and, therefore, computer simulation and e]q>ert systems have been successful in providing a structured approach to this problem (480,482,491-493). 

For approximately 20% to 30% of people with schizophrenia, drug treatment is ineffective. A standard definition of treatment resistance includes patients who have persistent positive symptoms despite treatment with at least two different antipsychotics given at adequate doses (at least 600 chlorpro-mazine equivalents) for an adequate duration (4 to 6 weeks). In addition, patients must have a moderately severe illness as defined by rating instruments, and have a persistence of illness for at least 5 years.40 These patients are often highly symptomatic and require extensive periods of hospital care. 

The viscosity vs. shear rate data for PTF and BTF (Figure 9) were obtained in n-heptane solution at 25°C using a Contraves low shear rate instrument. n-Heptane was used as a nonpolar solvent, as it has a high enough boiling point to avoid losses due to evaporation during the measurement period. The curves presented here are reproducible in both directions of shear and are thus t ime-independent. 

In addition to the clinical interview, psychometric rating instruments allow for rapid and reliable measurement of the nature and severity of depressive and associated symptoms. 

The cost, both in dollars (for commercially sold instruments) and in clinician time, must be considered. A clinician-rated instrument is sometimes superior (for some disorders), but when a parent rating or teacher rating is as useful, it might be preferred. 

Scahill, L., King, R.A., Schultz, R.T., and Leckman, J.F. (1999) Selection and use of diagnostic and clinical rating instruments. In Leckman, J.F., and Cohen, D.J., eds. Tourette s Syndrome—Tics, Obsessions, Compulsions Developmental Psychopathology and Clinical Care. New York John Wiley and Sons, pp. 310-324. 

Patient selection based on symptom severity. This can be defined directly by a minimal acceptable severity score as measured by a rating instrument (e.g. the Hamilton Rating Scale for Depression, the Positive and Negative Symptom Scale or other established assessment instruments see Section 5.6). An indirect definition of symptom severity may be a consequence of the status of a patient population a clinical trial designed for inpatients generally implies a more severe symptom profile than a study with... 

The clinical endpoint is a clinically meaningful measure of how patients feel, function or survive. Investigator-rated or self-assessed rating instruments are the most frequently used clinical endpoints. A primary endpoint is the main outcome that a study protocol is designed to evaluate. The statistical power and the sample size calculation of a particular trial are determined by the primary endpoint. Depending on the purpose of a study the primary endpoint can be... 

A safety parameter examples are drop-out rate due to adverse effects, adverse effects measured by a (side-effect-spedfic) rating instrument, biological markers, etc. 

DIAGNOSIS-SPECIFIC RATING INSTRUMENTS Depression Scales... 

The MADRS is a ten-item investigator-rated instrument for the assessment of depressive symptoms. It focuses on symptoms of sadness, lassitude, pessimistic thoughts and suicidality in contrast to the HRSD. no items are dedicated to the somatic aspects of depression. 

The Treatment Outcome PTSD Scale (TOP-8) is a clinician-rated instrument that measures the presence and severity of eight PTSD symptoms that occur frequently in PTSD patients and are sensitive to treatment. The scale was developed from the Structured Interview for PTSD (SI-PTSD Davidson et at., 1997), an alternative to the SCID. The TOP-8 questions are representative of the three major PTSD symptom dimensions (intrusive, avoidant and hyperarousal symptoms). Each symptom is rated on a defined step scale (0 4), with a high numeric rating indicating greater symptom severity (Davidson and Colket, 1997). The TOP-8 has proved sensitive to changes of PTSD symptoms in studies with antidepressants. 

The Davidson Trauma Scale (DTS) is a 17-item self-rated instrument that allows the patient to assess the level of distress caused by various symptoms. Patients are asked to rate both the frequency and severity of each item on a scale of 0 4, with a higher numeric rating reflecting a greater degree of distress (Davidson et al.. 1997). 

Additional trauma-related rating instruments are discussed in detail in Briere... 

The Brief Psychiatric Rating Scale (BPRS Overall and Gorham, 1962) is an 18-item rating instrument covering a wide range of psychopathology. Ratings are... 

In the reviews cited in this chapter there is often some breakdown of findings into those relating to heroin use, criminality, HIV-risk behaviours, social rehabilitation and nonopiate abuse. We have noted that crime was one of the earliest indicators in methadone treatment, while the wider range of outcomes is formalized in drug misuse rating instruments such as the Opiate Treatment Index (Darke et al. 1992a). The main areas in which methadone treatment has been found to be of substantial benefit are indicated in Table 1.3. 

All these studies essentially use the same definition for responder (i.e., 20% improvement on a standard rating instrument, usually the Positive and Negative Symptoms Scale [PANSS]). Because this criterion is the standard and was decided beforehand, there is no statistical problem of a post hoc choice of optimal cutoff points for dichotomization. 

The investigators who studied only the cognitive effects of triazolam (0.125 mg) stated, Elderly persons may remain unaware of or fail to express on standard rating instruments, the sedative effects of triazolam seen by an observer and evident in the results of tests of psychomotor function and memory ( 321). 

A unique and considerably more elaborate multiaxial test employs a thick-walled hollow sphere test specimen which may be pressurized internally or externally with a nearly incompressible liquid. Figure 20 illustrates the essential features of the test device as described by Bennet and Anderson (5). The specimen is prepared by casting propellant in a mold fitted with a sand-poly (vinyl alcohol) mandrel inside the sphere which may be removed easily after curing. A constant displacement rate instrument drives the piston to pressurize the chamber and apply large deformations. The piston s total displacement volume is transferred to... 

Installation and operational qualification work includes verification of temperature, pressure, and flow rates, instrument calibration, and thorough flushing of the entire system to remove oil, metal particles, and other contaminants. The type of testing and acceptance limits listed in the validation protocol may vary from firm to firm however, compressed air with product contact should be tested for such quality attributes as hydrocarbons, water vapor, and microbial content (typically less than 0.1 CFU/cu. ft.)... 

Due to the lower carrier gas flow rate, instruments with a differentially... 

A variation of the concentric cylinder viscometer is the rotating cylinder in an infinite sample . In this controlled (low) shear rate instrument, the sample is contained in a vessel of such large diameter relative to the cylinder s diameter that the vessel wall exerts no influence on the shear... 

In axial-flow viscometers, the sample is made to flow through a duct of regular cross-section. Capillary (circular cross-section) and slit (rectangular cross-section) viscometers are controlled stress instruments a known pressure difference (which causes shear stress in the sample) is applied over the duct length, and the resulting volumetric flow rate measured. In the extrusion viscometer, a controlled shear rate instrument, the sample is extruded through a capillary tube by the action of a constant speed piston, acting on the sample in a cylindrical reservoir to which the capillary is attached. The pressure difference between the ends of the capillary is measured. 

A summary of commercially available reaction-rate instruments and their applicability has been made. 

Parker, Pardue, and Willis S described a reaction-rate instrument including a reciprocal-time digital computer circuit designed for on-line variable-time analyses. Alkaline phosphatase could be determined satisfactorily with a relative standard deviation of about 1% if the times were in excess of 0.5 s. Their data indicate that, with proper calibration and temperature control, the limitations lie in the chemical and detection systems rather than in the rate-measuring system. 

Cyclone separators Can be designed to separate very small particles and to give good mass segregation. Particle cutoff size depends on inlet flow rate. Instrument size is proportional to l/D",/, ( Dmin = minimum particle diameter). 

---