Characterization of organic crystals for second-harmonic generation.

Second-harmonic generation (SHG) is a common technique with many applications. Common inorganic single-crystalline materials used to produce SHG light are effective using short IR/visible wavelengths but generally do not perform well at longer, technologically relevant IR wavelengths such as 1300, 1550, and 2000 nm. Efficient SHG materials possess many of the same key material properties as terahertz (THz) generators, and certain single-crystalline organic THz generation materials have been reported to perform at longer IR wavelengths. Consequently, this work focuses on characterizing three efficient organic THz generators for SHG, namely, DAST (trans-4-[4-(dimethylamino)-N-methylstilbazolium] p-tosylate), DSTMS (4-N,N-dimethylamino-4'-N'-methylstilbazolium 2,4,6-trimethylbenzenesulfonate), and the recently discovered generator PNPA ((E)-4-((4-nitrobenzylidene)amino)-N-phenylaniline). All three of these crystals outperform the beta-barium borate (BBO), an inorganic material commonly used for SHG, using IR pump wavelengths (1200-2000 nm).

Data Mining for Terahertz Generation Crystals.

A data mining approach to discover and develop new organic nonlinear optical crystals that produce intense pulses of terahertz radiation is demonstrated. The Cambridge Structural Database is mined for non-centrosymmetric materials and these structural data are used in tandem with density functional theory calculations to predict new materials that efficiently generate terahertz radiation. This enables us to (in a relatively short time) discover, synthesize, and grow large, high-quality crystals of four promising materials and characterize them for intense terahertz generation. In a direct comparison to the current state-of-the-art organic terahertz generation crystals, these new materials excel. The discovery and characterization of these novel terahertz generators validate the approach of combining data mining with density functional theory calculations to predict properties of high-performance organic materials, potentially for a host of exciting applications.

Depressive Symptoms and Suicidal Ideation Among Lawyers and Other Law Professionals.

Law professionals are an understudied population that is integral to society. Limited research indicates lawyers experience poor mental health, decreased wellbeing, and suicidality. This cross-sectional study recruited 654 law professionals and responses to a depression scale, the patient health questionnaire 9 (PHQ-9) were compared with the general working population. Lawyers were significantly more likely to report suicidal ideation "several days" and "more than half the days" as compared with the general working population, with odds ratios (OR) of 6.54 (95% confidence interval [CI] 4.16 to 10.29) and 5.50 (95% CI 2.23 to 13.53) respectively. Lawyers were more likely reported mild (OR = 3.89, 95% CI 3.04 to 4.96), moderate (OR = 5.29, 95% CI 3.61 to 7.76), moderately severe (OR = 9.71, 95% CI 5.50 to 17.14), and severe (OR = 18.34, 95% CI 6.00 to 56.11) depressive symptoms. 17.5% of lawyers in this study were experiencing symptoms equivalent to a diagnosis of a major depressive disorder.