Mid-infrared (MIR) nonlinear optical (NLO) crystals are crucial in generating MIR lasers, which are important in civilian and military applications. Compared to the extensively investigated ternary and quaternary chalcogenide NLO crystals, ternary phosphide crystals have a large nonlinearity coefficient and a wide transparency range. For instance, the well-known ternary chalcopyrite phosphide NLO crystal, ZnGeP 2 , possesses a large nonlinearity coefficient (d eff = 75 pm/ V) and a broad transmittance range of 0.75−12 μm. However, its applications in the far-infrared laser range were hindered by its strong absorption near 9 and 10−12 μm. Here, considering that Mn 2+ not only makes contributions to large secondharmonic generation (SHG) response but also extends the transparency wavelength range, a new ternary chalcopyrite phosphide crystal, MnSiP 2 (MSP), was rationally designed by substituting a II-site metal (Zn or Cd) for Mn in the II-Si-P 2 family. In this work, the synthesis and single-crystal growth of MSP were systematically investigated. The theoretical and experimental characterizations demonstrated that MSP exhibits a good balance between strong SHG behavior (6 × AgGaS 2 ) and large laser damage threshold (about 70 MW/cm 2 ). Specifically, the long-wavelength MIR cutoff edge of MSP is 18.2 μm, and the outstanding terahertz (THz) transmittance covers the range of 0.4−2.0 THz, indicating the ultrabroad transparency range. This work may provide a feasible strategy and impel one to search for promising outstanding MIR NLO crystals in the ternary phosphide family.

The outbreak of COVID-19 has spread across the world and was characterized as a pandemic. To protect medical laboratory personnel from infection, most laboratories inactivate the clinical samples before testing. However, the effect of inactivation on the detection results remains unknown. Here, we used a digital PCR assay to determine the absolute SARS-CoV-2 RNA copy number in 63 nasopharyngeal samples and assess the effect of inactivation methods on viral RNA copy number. Viral inactivation was performed with three different methods: (1) incubation with TRIzol® LS Reagent for 10 min at room temperature, (2) heating in a waterbath at 56°C for 30 min, and (3) high-temperature treatment, including 121°C autoclaving for 20 min, 100°C boiling for 20 min, and 80°C heating for 20 min. Compared to the amount of RNA in the original sample, TRIzol treatment destroyed 47.54% of N gene and 39.85% of ORF 1ab. For samples treated at 56°C for 30 min, the copy number of N gene and ORF 1ab was reduced by 48.55% and 56.40%, respectively. Viral RNA copy number dropped by 50–66% after 80°C heating for 20 min. Nearly no viral RNA was detected after autoclaving at 121°C or boiling at 100°C for 20 min. These results indicated that inactivation reduced the quantity of detectable viral RNA and may cause false negative results especially in weakly positive cases. Thus, TRIzol is recommended for sample inactivation in comparison to heat inactivation as Trizol has the least effect on RNA copy number among the tested methods.

Seeded flux growth of bulk o-SiP single crystals with layered structure and in-plane anisotropic photoresponse.

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