Metavalently bonded tellurides: the essence of improved thermoelectric performance in elemental Te.

Elemental Te is important for semiconductor applications including thermoelectric energy conversion. Introducing dopants such as As, Sb, and Bi has been proven critical for improving its thermoelectric performance. However, the remarkably low solubility of these elements in Te raises questions about the mechanism with which these dopants can improve the thermoelectric properties. Indeed, these dopants overwhelmingly form precipitates rather than dissolve in the Te lattice. To distinguish the role of doping and precipitation on the properties, we have developed a correlative method to locally determine the structure-property relationship for an individual matrix or precipitate. We reveal that the conspicuous enhancement of electrical conductivity and power factor of bulk Te stems from the dopant-induced metavalently bonded telluride precipitates. These precipitates form electrically beneficial interfaces with the Te matrix. A quantum-mechanical-derived map uncovers more candidates for advancing Te thermoelectrics. This unconventional doping scenario adds another recipe to the design options for thermoelectrics and opens interesting pathways for microstructure design.

The relationship between hypertriglyceridemic wait-to-height ratio and hypertension-diabetes comorbidity among older adult.

Objective: Limited information is available on the effect of hypertriglyceridemic waist-to-height ratio (HTHWH) and hypertension-diabetes comorbidity (HAD) in older adult people. We aimed to explore the relationship between HTHWH and HAD for the co-management of hypertension and diabetes mellitus in the older adult. Methods: A cross-sectional study, randomized cluster sampling from 10 community health service centers, and multivariate logistic regression were used in this study. A total of 3,501 participants aged 65 years or older recruited between January 2019 and December 2019 completed the study. Results: Among 3,501 participants, the median age was 69.96 years, and 42.50% were men. A total of 1,207 subjects were in the HTHWH group, and the prevalence rate of HAD was 17.23% in this group. Multivariate logistic regression analysis showed that, as compared with the normal group, the risk of HAD in the HTHWH group increased by 2.05 times (OR = 3.05, 95% CI: 2.06-4.51). The risks of hypertension or diabetes mellitus (HOD), hypertension, and diabetes mellitus were also increased in the HTHWH group, with their ORs (95%CIs) being 1.82 (1.44-2.29), 1.73 (1.38-2.17), and 2.28 (1.66-3.13), respectively. Conclusion: HTHWH significantly increases the risk of HAD and can be used as a reliable tool to screen the high-risk population for HAD.

Large Mobility Enables Higher Thermoelectric Cooling and Power Generation Performance in n-type AgPb18+xSbTe20 Crystals.

The room-temperature thermoelectric performance of materials underpins their thermoelectric cooling ability. Carrier mobility plays a significant role in the electronic transport property of materials, especially near room temperature, which can be optimized by proper composition control and growing crystals. Here, we grow Pb-compensated AgPb18+xSbTe20 crystals using a vertical Bridgman method. A large weighted mobility of ∼410 cm2 V-1 s-1 is achieved in the AgPb18.4SbTe20 crystal, which is almost 4 times higher than that of the polycrystalline counterpart due to the elimination of grain boundaries and Ag-rich dislocations verified by atom probe tomography, highlighting the significant benefit of growing crystals for low-temperature thermoelectrics. Due to the largely promoted weighted mobility, we achieve a high power factor of ∼37.8 µW cm-1 K-2 and a large figure of merit ZT of ∼0.6 in AgPb18.4SbTe20 crystal at 303 K. We further designed a 7-pair thermoelectric module using this n-type crystal and a commercial p-type (Bi, Sb)2Te3-based material. As a result, a high cooling temperature difference (ΔT) of ∼42.7 K and a power generation efficiency of ∼3.7% are achieved, revealing promising thermoelectric applications for PbTe-based materials near room temperature.

[Preliminary results of postoperative adjuvant treatment with tamoxifen in colorectal cancer].

OBJECTIVE: To investigate estrogen receptor (ER) expression and the effects of anti-estrogen therapy on the prognosis of colorectal carcinoma. METHODS: ER was measured in fresh colorectal cancer tissues by Dextran-coated charcoal (DCC) assay. The relationships between ER expression and clinicopathological parameters in colorectal cancer were analyzed. Tamoxifen was administrated postoperatively as adjuvant treatment. RESULTS: The positive rate of ER in colorectal tumor tissues was 37.0%. The 5-year survival rates of tamoxifen group and control group were 66.7% and 72.5% respectively, and there was no significant difference between the two groups. The distant metastasis rate of Tamoxifen group was significantly lower than that of control group (3% versus 20%). CONCLUSION: Some colorectal carcinomas are hormone-dependent tumors, and anti-estrogen therapy has no effect on them.