Though patch clamping at room temperature is a widely disseminated standard procedure in the electrophysiological community, it does not represent the biological system in mammals at around 37 °C. In order to better mimic the natural environment in electrophysiological studies, we present a custom-built, temperature-controlled patch clamp platform for upright microscopes, which can easily be adapted to any upright patch clamp setup independently, whether commercially available or home built. Our setup can both cool and heat the platform having only small temperature variations of less than 0.5 °C. We demonstrate our setup with patch clamp measurements at 36 °C on Jurkat T lymphocytes and human induced pluripotent stem cell-derived neurons. Passive membrane parameters and characteristic electrophysiological properties, such as the gating properties of voltage-gated ion channels and the firing of action potentials, are compared to measurements at room temperature. We observe that many processes that are not explicitly considered as temperature dependent show changes with temperature. Thus, we believe in the need of a temperature control in patch clamp measurements if improved physiological conditions are required. Furthermore, we advise researchers to only compare electrophysiological results directly that have been measured at similar temperatures since small variations in cellular properties might be caused by temperature alterations.

Two novel chromium oxide arsenide materials have been synthesized, Sr 2 CrO 2 Cr 2 OAs 2 (i.e., Sr 2 Cr 3 As 2 O 3 ) and Sr 2 CrO 3 CrAs (i.e., Sr 2 Cr 2 AsO 3 ), both of which contain chromium ions in two distinct layers. Sr 2 CrO 2 Cr 2 OAs 2 was targeted following electron microscopy measurements on a related phase. It crystallizes in the space group P 4/ mmm and accommodates distorted CrO 4 As 2 octahedra containing Cr 2+ and distorted CrO 2 As 4 octahedra containing Cr 3+ . In contrast, Sr 2 CrO 3 CrAs incorporates Cr 3+ in CrO 5 square-pyramidal coordination in [Sr 2 CrO 3 ] + layers and Cr 2+ ions in CrAs 4 tetrahedra in [CrAs] − layers and crystallizes in the space group P 4/ nmm . Powder neutron diffraction data reveal antiferromagnetic ordering in both compounds. In Sr 2 CrO 3 CrAs the Cr 2+ moments in the [CrAs] − layers exhibit long-range ordering, while the Cr 3+ moments in the [Sr 2 CrO 3 ] + layers only exhibit short-range ordering. However, in Sr 2 CrO 2 Cr 2 OAs 2 , both the Cr 2+ moments in the CrO 4 As 2 environments and the Cr 3+ moments in the CrO 2 As 4 polyhedra are long-range-ordered below 530(10) K. Above this temperature, only the Cr 3+ moments are ordered with a Néel temperature slightly in excess of 600 K. A subtle structural change is evident in Sr 2 CrO 2 Cr 2 OAs 2 below the magnetic ordering transitions.

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