Formation energies of native defects in Bi 2 (Te x Se 3−x), with comparison to ideal Bi 2 Te 2 S, are calculated in density-functional theory to assess transport properties. Bi 2 Se 3 is found to be n type for both Bi-and Se-rich growth conditions, while Bi 2 Te 3 changes fromn to p type going from Te-to Bi-rich conditions, as observed. Bi 2 Te 2 Se and Bi 2 Te 2 S are generally n type, explaining observed heavily doped n-type behavior in most samples. A (0/−) transition level at 16 meV above valence-band maximum for Bi on Te antisites in Bi 2 Te 2 Se is related to the observed thermally active transport gap causing a p-ton transition at low temperature. Bi 2 (Te x Se 3−x) with x>2 are predicted to have high bulk resistivity due to effective carrier compensation when approaching the n-to-pcrossover. Predicted behaviors are confirmed from characterization of our grown single crystals.

To transfer the preplan for the head and neck brachytherapy to the clinical implantation procedure, a preplan-based 3D-printed individual template for needle insertion guidance had previously been designed and used. The accuracy of needle insertion using this kind template was assessed in vivo. In the study, 25 patients with head and neck tumors were implanted with 125I radioactive seeds under the guidance of the 3D-printed individual template. Patients were divided into four groups based on the site of needle insertion: the parotid and masseter region group (nine patients); the maxillary and paranasal region group (eight patients); the submandibular and upper neck area group (five patients); and the retromandibular region group (six patients). The distance and angular deviations between the preplanned and placed needles were compared, and the complications and time required for needle insertion were assessed. The mean entrance point distance deviation for all 619 needles was 1.18 ± 0.81 mm, varying from 0.857 ± 0.545 to 1.930 ± 0.843 mm at different sites. The mean angular deviation was 2.08 ± 1.07 degrees, varying from 1.85 ± 0.93 to 2.73 ± 1.18 degrees at different sites. All needles were manually inserted to their preplanned positions in a single attempt, and the mean time to insert one needle was 7.5 s. No anatomical complications related to inaccurately placed implants were observed. Using the 3D-printed individual template for the implantation of 125I radioactive seeds in the head and neck region can accurately transfer a CT-based preplan to the brachytherapy needle insertion procedure. Moreover, the addition of individual template guidance can reduce the time required for implantation and minimize the damage to normal tissues.

The carbon–silicon switch strategy has become a key technique for structural optimization of drugs to widen the chemical space, increase drug activity against targeted proteins, and generate novel and patentable lead compounds. Flubeneteram, targeting succinate dehydrogenase (SDH), is a promising fungicide candidate recently developed in China. We describe the synthesis of novel SDH inhibitors with enhanced fungicidal activity to enlarge the chemical space of flubeneteram by employing the C–Si switch strategy. Several of the thus formed flubeneteram-silyl derivatives exhibited improved fungicidal activity against porcine SDH compared with the lead compound flubeneteram and the positive controls. Disease control experiments conducted in a greenhouse showed that trimethyl-silyl-substituted compound W2 showed comparable and even higher fungicidal activities compared to benzovindiflupyr and flubeneteram, respectively, even with a low concentration of 0.19 mg/L for soybean rust control. Furthermore, compound W2 encouragingly performed slightly better control than azoxystrobin and was less active than benzovindiflupyr at the concentration of 100 mg/L against soybean rust in field trials. The computational results showed that the silyl-substituted phenyl moiety in W2 could form strong van der Waals (VDW) interactions with SDH. Our results indicate that the C–Si switch strategy is an effective method for the development of novel SDH inhibitors.

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Transmission synchrotron diffraction was employed to characterize the Ga ordering in magnetostrictive Fe 100−x Ga x alloys with Ga concentrations from 0 to 20.3 at. %. The experiments focused on the development of atomic short-range ordering (SRO) by analysis of the diffuse scattering appearing at superlattice positions of the D0 3 ordered alloy structure. No SRO was found for Ga concentrations less than 4 at. %. Between 13 and 20.3 at. %, D0 3 -type SRO clusters are observed whose size increases with Ga concentration for both slowcooled and quenched samples. Thermal quenching of the samples suppresses the cluster sizes when compared to slow-cooled samples of the same concentration. For quenched samples with large Ga concentration, Ga pairing is evidenced by growing B2-type correlations. At low concentrations, the presence of SRO appears to have little (if any) effect on the enhanced magnetostriction. However, the dramatic suppression of magnetostriction near ∼20 at. % Ga can be linked rapid growth of SRO just before the onset of long-range chemical order. Transmission synchrotron diffraction was employed to characterize the Ga ordering in magnetostrictive Fe 100−x Ga x alloys with Ga concentrations from 0 to 20.3 at. %. The experiments focused on the development of atomic short-range ordering ͑SRO͒ by analysis of the diffuse scattering appearing at superlattice positions of the D0 3 ordered alloy structure. No SRO was found for Ga concentrations less than 4 at. %. Between 13 and 20.3 at. %, D0 3 -type SRO clusters are observed whose size increases with Ga concentration for both slowcooled and quenched samples. Thermal quenching of the samples suppresses the cluster sizes when compared to slow-cooled samples of the same concentration. For quenched samples with large Ga concentration, Ga pairing is evidenced by growing B2-type correlations. At low concentrations, the presence of SRO appears to have little ͑if any͒ effect on the enhanced magnetostriction. However, the dramatic suppression of magnetostriction near ϳ20 at. % Ga can be linked rapid growth of SRO just before the onset of long-range chemical order.