Silicone Oils

The detailed procedure has been published before^{20 (link),21 (link)}. In brief, mice were anesthetized by an intraperitoneal injection of Avertin (0.3mg/g) and received the SO (Alcon Laboratories, 1000 mPa.s) injection at 9–10 weeks of age. Prior to injection, one drop of 0.5% proparacaine hydrochloride (Akorn, Somerset, New Jersey) was applied to the cornea to reduce its sensitivity during the procedure. A 32G needle was tunneled through the layers of the cornea at the superotemporal side close to the limbus to reach the anterior chamber without injuring lens or iris. Following this entry, ~ 2µl silicone oil (1000 mPa s, Silikon, Alcon Laboratories, Fort Worth, Texas) was injected slowly into the anterior chamber using a homemade sterile glass micropipette, until the oil droplet expanded to cover most areas of the iris (diameter ~ 1.8–2.2mm). After the injection, veterinary antibiotic ointment (BNP ophthalmic ointment, Vetropolycin, Dechra, Overland Park, Kansas) was applied to the surface of the injected eye. The contralateral control eyes received 2 µl normal saline to the anterior chamber. During the whole procedure, artificial tears (Systane Ultra Lubricant Eye Drops, Alcon Laboratories, Fort Worth, Texas) were applied to keep the cornea moist.

All experiments were carried out at room temperature (22 ± 2 °C). Conventional electrochemical experiments were performed in a three electrode format with an Ag/AgCl QRCE (preparation described above) and platinum wire (Goodfellow, U.K.) auxiliary electrode on a CHI-730A potentiostat (CH instruments, U.S.A.). All other electrochemical experiments were carried out in the SECCM format on a home-built electrochemical workstation.^{34 ,45 (link)} In this setup, a dual-barreled nanopipet probe was filled with electrolyte solution (5 or 100 mM HClO₄) and mounted on a z-piezoelectric positioner (P-753.3CD, PhysikInstrumente). The tip of the nanopipet probes were elliptical in shape, with major (r_a) and minor (r_b) radii of approximately 250 nm and 130 nm, respectively, as shown in Fig. S2a.† Ag/AgCl wire placed in each barrel served as QRCEs (detailed above). A bias potential (E_b) of either +0.05 V (100 mM HClO₄) or +0.2 V (5 mM HClO₄) was applied between the QRCEs in order to generate an ion conductance current, which was used as a feedback signal during positioning of the nanopipet probe (see below). The nanopipet was positioned above the surface of interest using micropositioners for coarse movement and an xy-piezoelectric positioner (P-622.2CD, PhysikInstrumente) for fine movement. The nanopipet was oscillated normal to the surface of interest (f ≈ 280 Hz, Δz ≈ 30 nm peak-to-peak) by an ac signal generated by a lock-in amplifier (SR830, Stanford Research Systems, U.S.A.) applied to the z-piezoelectric positioner. During approach, the magnitude of the ac ion conductance current generated by distance modulation (measured using the same lock-in amplifier) was used as feedback to detect when the meniscus at the end of the nanopipet had made contact with the working electrode surface.^{34 ,45 (link)} The nanopipet itself did not contact the substrate. Electrochemical (voltammetric) measurements were performed in the confined area defined by the meniscus (droplet cell) created between the tip and substrate. The size of the confined area (i.e., working electrode area) was determined by (SEM) imaging the droplet “footprint” left after electrochemical measurements, as demonstrated in Fig. S2b.†Electrochemical measurements at the substrate (working electrode) were made using a linear-sweep voltammetric “hopping” regime, as described previously.^{37 (link),39 (link),40 (link)} In brief, as shown schematically in Fig. 1a, the nanopipet was approached to the surface of interest at a series of predefined locations in a grid and, upon each landing, a linear sweep voltammetric experiment was carried out, building up an voltammetric ‘map’ of the substrate. In other words, in the resulting “electrochemical map” (equipotential image), each pixel corresponds to an individual LSV. The hopping distance between each pixel was 1 μm to avoid overlap of the probed areas. Note that in the images and movies presented, there is no interpolation of the data.
The SECCM cell and all piezoelectric positioners were placed in an aluminum Faraday cage equipped with heat sinks and vacuum panels to block out all light (important in the study of semiconducting materials) and minimize noise and thermal drift. The QRCE potentials were controlled (with respect to ground) with a home-built bipotentiostat and the substrate (working electrode, common ground) current was measured using a home-built electrometer with variable data acquisition times. A home-built 16th order (low-pass) brick-wall filter unit (time constant = 2 ms) was utilized during data (current) collection. Data acquisition and fine control of all the instruments was achieved using an FPGA card (PCIe-7852R) controlled by a LabVIEW 2016 (National Instruments, U.S.A.) interface. Data treatment and analysis was carried out using the Matlab R2015b (8.6.0.267246, Mathworks, U.S.A.) and OriginPro 2016 64bit (b9.3.226, OriginLab, U.S.A.) software packages.
The dual-barrelled nanopipets were pulled from quartz filamented theta-capillaries (QTF120-90-100, Friedrich & Dimmock Inc., U.S.A.) using a CO₂-laser puller (P-2000, Sutter Instruments, U.S.A.). Following pulling, the outer walls of nanopipet tips were silanized with dichlorodimethylsilane to aid meniscus confinement (and stability) when coming into contact with the substrate of interest. After the nanopipet tips were filled with the solution of interest using a MicroFil syringe (World Precision Instruments Inc., U.S.A.), a layer of silicone oil (DC 200, Sigma-Aldrich) was added on top in order to minimize evaporation (exacerbated by the filament, shown schematically in Fig. S3†). The QRCEs were then inserted through the oil layer, into the solution of interest, and mounted on the z-piezoelectric positioner, as described above.

According to the method described by Sun et al. (18 (link)) with minor modifications to determine the rheological properties (Viscotester iQ, Thermo Fisher Scientific Shier, Guangzhou, China) of the samples. Tests were performed in gradient warming oscillation mode using 50 mm plates. The samples were uniformly coated on the test platform. Before the test, the sample edges were sealed with silicone oil to keep closed. Then, the temperature was increased from 20 to 80°C at a rate of 1°C/min with a frequency of 0.1 Hz and a plate spacing of 0.6 mm.

Physiological susceptibility tests for transfluthrin were conducted for each mosquito strain before the start of semi-field experiments. The tests were performed using tube test bioassays following World Health Organization (WHO) guidelines [25 ]. As there is no recommended discriminating dose of transfluthrin for testing the susceptibility status of these mosquitoes, transfluthrin-impregnated papers at the doses proposed by Sukkanon et al. [26 (link)] were used. Five serial dilutions of emulsifiable concentrate (EC) were prepared by mixing with acetone and silicone oil in individual Falcon tubes. The concentrations of EC transfluthrin were 0.00125%, 0.0025%, 0.005%, 0.01%, 0.02%, 0.04%, 0.08% and 0.1% for Anopheles, and 0.003125%, 0.00625%, 0.125%, 0.025%, 0.05% and 0.1% for Ae. aegypti. Whatman grade 1 filter papers (12 × 15 cm; Whatman International, Banbury, UK) were prepared by impregnation with the concentrations of EC transfluthrin. For each filter paper, 2 ml of diluted EC transfluthrin was used. The impregnated papers were air-dried in the shade at ambient temperature, then wrapped in aluminium foil and refrigerated at 4 °C before use in the tests that were carried out on the same day. The papers were destroyed after the experiment.
One hundred and fifty non-blood-fed, 3–5-day-old mosquitoes were exposed to the transfluthrin-treated paper or to the control for 1 h. The mosquitoes were then provided with 10% sucrose solution and maintained at approximately 27 °C and 80% RH for the determination of 24 h mortality. Each dilution was tested four times.
The discriminating concentration (DC) for Anopheles (Table 4) was used to test the susceptibility status of An. gambiae (Kisumu strain; KDR) and An. funestus (FUMOZ strain). The same procedure was used as in the susceptibility test, and the same numbers of mosquitoes were exposed to the transfluthrin-treated paper as per the obtained DC.

To evaluate the spectral performance, we prepared 5 × 5 mm² unpolished as-cut samples of varying thicknesses (2, 5, 10, and 20 mm) sawed from a larger (5 × 5 × 50 mm³) unpolished Ce:GAGG single-crystal block (TPS, Republic of Korea) grown by the Czochralski technique. The mechanically polished reference samples were prepared using a polisher (XP 8, Ted Pella) with alumina suspension (particle size: 1 μm). The chemically polished samples were fabricated by dipping the as-cut samples into a beaker containing phosphoric acid (85% in volume), placed in a silicone oil bath, to evaluate the effect of chemical polishing on the light output of the crystal samples [11 (link), 12 (link)]. First, to investigate the correlation between the chemical polishing time and the etching rate, groups of 5 × 5 × 2 mm³ Ce:GAGG single-crystal samples were etched separately for 5, 10, 20, 30, 60, 90, and 120 min. As described before, the transmittance of the scintillation light to the photosensor is also dependent on the crystal thickness; thus, the Ce:GAGG single-crystal samples of 2, 5, 10, and 20 mm thicknesses were chemically polished for 30, 60, 90, and 120 min to compare their light outputs. The two polishing methods and spectral data acquisition process are illustrated in Fig 1. After the chemical polishing, each sample was cleaned with deionized water and dried in air. Next, the change in the weight of each sample was recorded to assess the weight loss due to chemical polishing.