This study examined the Panic Disorder Self-Report (PDSR), a new self-report diagnostic measure of panic disorder based on the 4th edition of the Diagnostic and Statistical Manual of Mental Disorders (American Psychiatric Association, 1994). PDSR diagnoses were compared with structured interview diagnoses of individuals with generalized anxiety disorder, social phobia, and panic disorder and nonanxious controls. Receiver operating characteristic analyses revealed that the PDSR showed 100% specificity and 89% sensitivity. The PDSR also demonstrated retest reliability, convergent and discriminant validity, and kappa agreement of .93 with a structured interview. Finally, the PDSR demonstrated clinical validity. Students who were identified as having panic disorder using the PDSR did not have significantly different scores on the Panic Disorder Severity Scale--Self-Report form (P. R. Houck, D. A. Speigel, M. K. Shear, & P. Rucci, 2002) than a panic disordered community sample. However, both groups had significantly higher scores than students identified as not meeting criteria for panic disorder.

Grain-oriented ceramics of ferroelectric lead metaniobate have been prepared by molten salt synthesis of anisotropic crystallites followed by doctor blade casting. The sintered ceramics have an orthorhombic texture with elongated c axis grains parallel to the casting direction. This allows efficient poling in directions perpendicular to the tape.N RECENT years novel fabrication techof ceramics with textured microstructures. The earlier applications were in the production of magnetic ceramics.' More rcently, hot-forging techniques have produced grain-oriented ferroelectrics,2 primarily directed toward maximizing piezoelectric properties. The most recent and possibly simplest technique is a combination of molten salt synthesis of anisotropic crystallites and conventional doctor blade casting., This system has been shown to produce highly oriented ceramics for the layer structures Bi4Ti3OI2 and Bi2W06.This communication presents preliminary data demonstrating that the moltensalt-tape-casting method can produce ceramic that is more than just oriented in the sheet of the casting but is actually orthorhombic in texture and in electrical properties. The oxide chosen for study is lead metaniobate which is used commercially in piezoelectric transducers because of three outstanding properties4: a very high Curie point (570"C), a very low mechanical Q (.=20), and a large d,,/d,l ratio. The large ratio results in a large hydrostatic piezoelectric effect dh=d33=2d31. For this reason, PbNb206 is preferred over PZT for hydrostatic pressure detectors. The lower dielectric constant of PbNb206 is also ad-

Grain-oriented BizWOa ceramics were fabricated by normal sintering techniques. Platelike crystallites were initially synthesized by a fused salt process using an NaCl-KCI melt. When calcined at <800°C, the Bi2W0, crystallites are 325 p m in size and, at >850°C, =lo0 pm. After dissolving away the salt matrix, the BizW06 particles were mixed with an organic binder and tapecast to align the plateliie crystallites. Large particles were easily oriented by tapecasting but the sinterability of the tape was poor. Preferred orientation of small particles was increased by tapecasting and grain growth during sintering further improves the degree of orientation. Sintering above the 950°C phase transition, however, results in discontinuous grain growth and low densities. Optimum conditions for obtaining highly oriented ceramics with high density occur at sintering temperatures of 900°C using fine-grained powders which yield orientation factors of ==0.88 and densities of 94% theoretical.

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