Bi2Te3-Based Thermoelectric Modules for Efficient and Reliable Low-Grade Heat Recovery.

Bismuth-telluride-based alloy has long been considered as the most promising candidate for low-grade waste heat power generation. However, optimizing the thermoelectric performance of n-type Bi2Te3 is more challenging than that of p-type counterparts due to its greater sensitivity to texture, and thus limits the advancement of thermoelectric modules. Herein, the thermoelectric performance of n-type Bi2Te3 is enhanced by incorporating a small amount of CuGaTe2, resulting in a peak ZT of 1.25 and a distinguished average ZT of 1.02 (300-500 K). The decomposed Cu+ strengthens interlayer interaction, while Ga+ optimizes carrier concentration within an appropriate range. Simultaneously, the emerged numerous defects, such as small-angle grain boundaries, twin boundaries, and dislocations, significantly suppresses the lattice thermal conductivity. Based on the size optimization by finite element modelling, the constructed thermoelectric module yields a high conversion efficiency of 6.9% and output power density of 0.31 W cm-2 under a temperature gradient of 200 K. Even more crucially, the efficiency and output power little loss after subjecting the module to 40 thermal cycles lasting for 6 days. This study demonstrates the efficient and reliable Bi2Te3-based thermoelectric modules for broad applications in low-grade heat harvest.

High Performance Thermoelectric Power of Bi0.5Sb1.5Te3 Through Synergistic Cu2GeSe3 and Se Incorporations.

Bi2Te3-based alloys are the benchmark for commercial thermoelectric (TE) materials, the widespread demand for low-grade waste heat recovery and solid-state refrigeration makes it imperative to enhance the figure-of-merits. In this study, high-performance Bi0.5Sb1.5Te3 (BST) is realized by incorporating Cu2GeSe3 and Se. Concretely, the diffusion of Cu and Ge atoms optimizes the hole concentration and raises the density-of-states effective mass (md *), compensating for the loss of "donor-like effect" exacerbated by ball milling. The subsequent Se addition further increases md *, enabling a total 28% improvement of room-temperature power factor (S2σ), reaching 43.6 µW cm-1 K-2 compared to the matrix. Simultaneously, the lattice thermal conductivity is also significantly suppressed by multiscale scattering sources represented by Cu-rich nanoparticles and dislocation arrays. The synergistic effects yield a peak ZT of 1.41 at 350 K and an average ZT of 1.23 (300-500 K) in the Bi0.5Sb1.5Te2.94Se0.06 + 0.11 wt.% Cu2GeSe3 sample. More importantly, the integrated 17-pair TE module achieves a conversion efficiency of 6.4%, 80% higher than the commercial one at ΔT = 200 K. These results validate that the facile composition optimization of the BST/Cu2GeSe3/Se is a promising strategy to improve the application of BST-based TE modules.

Enhanced Thermoelectric Performance of P-Type (Bi,Sb)2 Te3 by Incorporating Non-Stoichiometric Ag5 Te3 and Refining Te-Se Ratio.

Power generation modules utilizing thermoelectric (TE) materials are suitable for recycling widespread low-grade waste heat (<600 K), highlighting the immediate necessity for advanced Bi2 Te3 -based alloys. Herein, the substantial enhancement in TE performance of the p-type Bi0.4 Sb1.6 Te3 (BST) sintered sample is realized by subtly incorporating the non-stoichiometric Ag5 Te3 and counteractive Se. Specifically, Ag atoms diffused into the BST lattice improve the density-of-states effective mass (md * ) and boost the hole concentration for the suppressed bipolar effect. The addition of Se further improves md * prompting the room-temperature power factor upgrade to 46 W cm-1  K-2 . Concurrently, the lattice thermal conductivity is considerably lowered by multiple scattering sources exemplified by Sb-rich nanoprecipitates and dense dislocations. These synergistic results yield a high peak ZT of 1.44 at 375 K and an average ZT of 1.28 between 300 and 500 K in the Bi0.4 Sb1.6 Te2.95 Se0.05 + 0.05 wt.% Ag5 Te3 sample. More significantly, when coupled with n-type zone-melted Bi2 Te2.7 Se0.3 , the integrated 17-pair TE module achieves a competitive conversion efficiency of 6.1% and an output power density of 0.40 W cm-2 at a temperature difference of 200 K, demonstrating great potential for practical applications.

Optimized Thermoelectric Cooler Performance by the Structure-Matching Design of Asymmetrical p/n-Type Legs.

Commercial Bi2Te3-based thermoelectric (TE) coolers typically comprise equal-size p- and n-type legs. However, this traditional structure limits the cooling temperature differences of TE coolers (TECs) due to identical current density, when their electrical or thermal characteristics differ significantly. This work presents a novel design of p- and n-type TE legs to optimize the performance of TECs. The cooling properties of the materials are initially calculated by theoretical equations and then evaluated by using a combination of finite element simulations and experiments. The research findings suggest that by utilizing higher ZT p-type materials to enhance the TEC cooling performance, further optimization of the ratio of the cross-sectional area of the TE legs (Ap/An) improves the structural matching of the legs, which achieves the maximum figure of merit Z and leads to a 5.4% increase in cooling power density. Additionally, the TEC with optimized Ap/An increases the cooling temperature difference by 3.3 and 2.7 K for the same current at hot side temperatures of 300 and 315 K, respectively, while the coefficient of performance remains unchanged. Moreover, the maximum cooling temperature difference reaches 70 and 74 K, respectively. We anticipate that our results will guide the design and optimization of the TECs.

Synthesis of CsPbBr3 in Micro Total Reaction System: Fast Operation Space Mapping and Subsecond Growth Process Monitoring.

Lead halide perovskite nanocrystals (LHP NCs) have the characteristics of fast reaction kinetics and crystal instability due to the intrinsically highly ionic bonding between the respective ions, which bring challenges for revealing the growth kinetics and practical applications. Compared with conventional batch synthesis methods, the single-function microreactor can achieve precise and stable control of the NCs synthesis process, but it still has the shortcoming of not being able to obtain information about the growth process. In this study, a micro Total Reaction System (µTRS) with remote control, online detection, and rapid data analysis functions is designed. µTRS can sample the photoluminescence information of CsPbBr3 NCs growth in ligand-assisted reprecipitation method. CsPbBr3 NCs with an emission range of 435-492 nm are successfully detected, which breaks the record of the smallest size of CsPbBr3 NCs synthesized directly from precursors. The real-time feature of µTRS enables the construction of an automated close-loop synthesis system. Besides, the rapid acquisition and timely processing of product information enable the rapid mapping of the operation space for CsPbBr3 NCs preparation, which provides a reliable and learnable data set for designing a fully autonomous microreaction system capable of synthesizing NCs.

Efficacy and safety of inclisiran in stroke or cerebrovascular disease prevention: a systematic review and meta-analysis of randomized controlled trials.

Aims: As the impact of inclisiran in stroke prevention in atherosclerotic cardiovascular disease (ASCVD) patients or those at high risk of ASCVD is still unclear, we conducted a systematic review and meta-analysis of randomized controlled trials (RCT) to quantify the effectiveness of inclisiran in stroke prevention in these patients. Methods: Literature research was conducted in four electronic databases (PubMed, EMBASE, Web of Science, CENTRAL) and two clinical trials registers (ClinicalTrials.gov, WHO ICTRP) from the inception of the study to 17 October 2022, and was updated by the end of the study on 5 January 2023. Two authors independently screened the studies, extracted the data, and assessed the bias. The risk of bias was assessed using the Cochrane risk-of-bias tool for randomized trials (RoB 2). The intervention effect was estimated by calculating risk ratio (RR), weighted mean difference (WMD), and 95% confidence interval (CI) with R 4.0.5. Sensitivity analysis by changing meta-analysis model was also performed to test the robustness of the pooled results. If this was not possible, a descriptive analysis was conducted. Results: Four RCTs (n = 3,713 patients) were rated as high-risk bias. Meta-analysis of three RCTs (ORION-9, ORION-10, and ORION-11) showed that inclisiran reduced myocardial infarction (MI) risk by 32% (RR = 0.68, 95%CI = 0.48-0.96) but did not reduce stroke (RR = 0.92, 95%CI = 0.54-1.58) and major cardiovascular events (MACE) (RR = 0.81, 95%CI = 0.65-1.02) risk. Sensitivity analysis results were stable. Safety was similar to the placebo group but had frequent injection-site reactions (RR = 6.56, 95%CI = 3.83-11.25), which were predominantly mild or moderate. A descriptive analysis of one RCT (ORION-5) was conducted due to different study designs, and suggested that inclisiran might be given semiannually from the beginning. Conclusion: Inclisiran is not beneficial for stroke or MACE prevention in ASCVD or patients at high risk of ASCVD but is associated with the reduction of MI. Given the limited number and quality of the available studies and the lack of a standardized definition for cardiovascular events, further studies are essential for confirming the results.

High-Performance Industrial-Grade p-Type (Bi,Sb)2 Te3 Thermoelectric Enabled by a Stepwise Optimization Strategy.

As the sole dominator of the commercial thermoelectric (TE) market, Bi2 Te3 -based alloys play an irreplaceable role in Peltier cooling and low-grade waste heat recovery. Herein, to improve the relative low TE efficiency determined by the figure of merit ZT, an effective approach is reported for improving the TE performance of p-type (Bi,Sb)2 Te3 by incorporating Ag8 GeTe6 and Se. Specifically, the diffused Ag and Ge atoms into the matrix conduce to optimized carrier concentration and enlarge the density-of-states effective mass while the Sb-rich nanoprecipitates generate coherent interfaces with little loss of carrier mobility. The subsequent Se dopants introduce multiple phonon scattering sources and significantly suppress the lattice thermal conductivity while maintaining a decent power factor. Consequently, a high peak ZT of 1.53 at 350 K and a remarkable average ZT of 1.31 (300-500 K) are attained in the Bi0.4 Sb1.6 Te0.95 Se0.05  + 0.10 wt% Ag8 GeTe6 sample. Most noteworthily, the size and mass of the optimal sample are enlarged to Ø40 mm-200 g and the constructed 17-couple TE module exhibits an extraordinary conversion efficiency of 6.3% at ΔT = 245 K. This work demonstrates a facile method to develop high-performance and industrial-grade (Bi,Sb)2 Te3 -based alloys, which paves a strong way for further practical applications.

Targeted inhibition of FcRn reduces NET formation to ameliorate experimental ulcerative colitis by accelerating ANCA clearance.

Dysregulated immune responses have now been recognized as an essential stimulator of ulcerative colitis (UC). Neutrophil extracellular traps (NET) were reported as the potential factor in sustaining mucosal inflammation in UC. NET formation further induces antineutrophil cytoplasm autoantibodies (ANCA) that serve as a biomarker in determining the severity of UC, which have a long half-life due to neonatal Fc receptor (FcRn)-mediated recycling. This study aimed to explore the role of the ANCA-NET cycle in UC and evaluate the potential of targeting FcRn in UC treatment. Dextran sodium sulfate-induced mice and rat models were used in this study. anti-rat FcRn monoclonal antibodies were used to block FcRn function in vivo. Disease activity index (DAI) and histopathological score (HS) were estimated to characterize the inflammation severity of UC. Serum concentrations of IgG, ANCA, TNF-α, IL-1ß and CRP were measured using specific ELISA kits. Colonic NET-associated protein (NAP) expression was determined by western blotting. Serum ANCA and colonic NAPs showed a positive correlation that varied with changes in serum inflammation-related indexes (IRI; including TNF-α, IL-1ß, and CRP) and DAI and HS in mice with UC. Blockade of FcRn significantly reduced serum ANCA levels and colonic NAP expression and effectively decreased serum IRIs, DAI, and HS in rats with UC. Especially during the inflammation recurrence period, blockade of FcRn exerted even better therapeutic effects in rats with UC than salazosulfapyridine. Our results show that anti-FcRn therapy has benefits in UC treatment through reduced colonic NET formation by accelerating serum ANCA clearance.

Synergistic Manipulation of Interdependent Thermoelectric Parameters in SnTe-AgBiTe2 Alloys by Mn Doping.

In the mid-temperature region, SnTe is a promising substitute for PbTe, whereas the thermoelectric (TE) property of pristine SnTe is severely limited by the good thermal conductivity and inferior Seebeck coefficient. In this research, we synergistically manipulate the interdependent TE parameters of SnTe-AgBiTe2 alloys by Mn doping to increase the ZT value. The AgBiTe2 alloying is found to greatly reduce the electrical conductivity and electronic contribution for thermal transport by reducing the carrier mobility, while Mn doping obviously improves the Seebeck coefficient by effectively decreasing the valence band offset. The lowest κl of Mn-doped SnTe-AgBiTe2 alloys is 0.49 W m-1 K-1 at 823 K since the various defects strengthen the phonon scattering. Collectively, these manipulations yield a peak ZT value of 1.40 at 823 K and an average ZT value of 0.73 (300-823 K) in the Mn-doped SnTe-AgBiTe2 alloys. This research suggests that Mn doping is a valid scheme to constantly improve the thermoelectric property of SnTe-AgBiTe2 alloys in a wide temperature range.

Optimized Thermoelectric Properties of Bi0.48Sb1.52Te3 through AgCuTe Doping for Low-Grade Heat Harvesting.

Zone-melted Bi2Te3-based alloys are the only commercially available thermoelectric (TE) materials, but they suffer from mediocre figure of merit (ZT) values and brittleness. In this work, we prepared Bi0.48Sb1.52Te3 sintered samples using a hot-pressing method and added tiny AgCuTe to improve the comprehensive properties. Because the carrier concentration is boosted by the AgCuTe addition, the bipolar effect at higher temperature is explicitly suppressed and the power factor is also improved in a broad temperature scope. Simultaneously, κlat is mostly diminished by the introduced phonon scattering centers comprising point defects, dislocations, and grain boundaries. Consequently, we achieved a ZTmax of 1.25 at 350 K and its average ZTave of 1.1 from 300 to 500 K in the (Bi0.48Sb1.52Te3 + 3 wt % Te) + 0.12 wt % AgCuTe sample. Composed of this sample and commercial Bi2Te2.5Se0.5, the fabricated TE module manifests a maximum power output density of 0.31 W cm-2 (Tcold = 300 K and Thot = 500 K). This work suggests that AgCuTe-doped Bi0.48Sb1.52Te3 is promising for recovering low-grade thermal energy near room temperature.

Assessing CYP2C8-Mediated Pharmaceutical Excipient-Drug Interaction Potential: A Case Study of Tween 80 and Cremophor EL-35.

Pharmaceutical excipients (PEs) are substances included in drug formulations. Recent studies have revealed that some PEs can affect the activity of metabolic enzymes and drug transporters; however, the effects of PEs on CYP2C8 and its interaction potential with drugs remain unclear. In this study, we evaluated the effects of Tween 80 and EL-35 on CYP2C8 in vitro and further investigated their impacts on the PK of paclitaxel (PTX) in rats after single or multiple doses. The in vitro study indicated that Tween 80 and EL-35 inhibited CYP2C8 activity in human and rat liver microsomes. EL-35 also decreased the expression of CYP2C8 in HepG2 cells. In the in vivo study, Tween 80 did not alter the PK of PTX after single or multiple doses, whereas EL-35 administered for 14 days significantly increased the AUC and MRT of PTX. Further analysis indicated that multiple-dose EL-35 reduced the expression of Cyp2c22 and production of 6-OH-PTX in the rat liver. Our study suggested that short-term exposure to both PEs did not affect the PK of PTX in rats, but multiple doses of EL-35 increased the AUC and MRT of PTX by downregulating the hepatic expression of Cyp2c22. Such effects should be taken into consideration during drug formulation and administration.

CREBBP knockdown suppressed proliferation and promoted chemo-sensitivity via PERK-mediated unfolded protein response in ovarian cancer.

CREBBP, in short CBP, has been reported to be involved in tumorigenesis in various cancers, but its role in ovarian cancer remains largely unexplored. In our study, survival analysis of CBP in patients with ovarian cancer was conducted using the Kaplan-Meier Plotter database, then we utilized specific shRNA targeting CREBBP to block the expression of CBP, and detected its effect on cell proliferation and chemo-sensitivity in ovarian cancer cells. The results showed that high expression of CBP was correlated with poor prognosis in ovarian cancer patients. CREBBP knockdown in ovarian cancer cells significantly inhibited tumor proliferation both in vitro and in vivo. Moreover, CREBBP knockdown promoted chemo-sensitivity in ovarian cancer cells. Mechanism research further demonstrated that CREBBP knockdown attenuated unfolded protein response (UPR), which was mediated by PERK/ATF4/STC2 signaling pathway. Our research linked CBP and UPR in ovarian cancer and may provide new strategies for the clinical treatment of ovarian cancer.

Enhanced Thermoelectric and Mechanical Performances in Sintered Bi0.48Sb1.52Te3-AgSbSe2 Composite.

Bismuth telluride alloys have dominated the industrial application of thermoelectric cooling, but the relatively poor mechanical performance of commercial zone-melting material seriously limits the device integration and stability. Here, we exhibit synergistically enhanced thermoelectric and mechanical performances of sintered Bi0.48Sb1.52Te3-AgSbSe2 composites. It is found that the increased hole concentration improves the S2σ to 40 µW cm-1 K-2 at room temperature, and the emerged various defects effectively suppress the κl to 0.57 W m-1 K-1 at 350 K. All effects harvest a highest ZT = 1.2 at 350 K along with an average ZT = 1.0 between 300-500 K in the x = 0.2 sample. Notably, AgSbSe2 addition not only optimizes the thermoelectric properties, but also enhances the mechanical performance with a Vickers hardness of 0.75 GPa. Furthermore, the isotropy of thermoelectric properties is also observably promoted by solid-phase reaction combined with high-energy ball milling and hot pressing. Our study reveals a viable strategy to improve the comprehensive performance of sintered bismuth telluride materials.

Achieving High Thermoelectric Performance of n-Type Bi2Te2.79Se0.21 Sintered Materials by Hot-Stacked Deformation.

Bismuth telluride has been the only commercial thermoelectric candidate, but the n-type sintered material lags well behind the p-type one in the zT value, which severely limits the further development of thermoelectrics. Here, we report a promising technique named hot-stacked deformation to effectively improve the thermoelectric properties of n-type Bi2Te2.79Se0.21 + 0.067 wt % BiCl3 materials based on zone-melting ingots. It is found that a high grain alignment is maintained during the plastic deformation and the carrier concentration is properly optimized owing to the donor-like effect, leading to an enhanced power factor. Moreover, the lattice thermal conductivity is obviously suppressed due to the emerged phonon scattering centers of dense grain boundaries and dislocations. These effects synergistically yield a maximum zT value of 1.38 and an average zTave of 1.18 between 300 and 500 K in the hot-stacked deformed sample, which is approximately 42% higher than those of the zone-melting ingots.

Phonon Engineering for Thermoelectric Enhancement of p-Type Bismuth Telluride by a Hot-Pressing Texture Method.

Phonon engineering is a core stratagem to improve the thermoelectric performance, and multi-scale defects are expected to scatter a broad range of phonons and compress the lattice thermal conductivity. Here, we demonstrate obviously enhanced thermoelectric properties in Bi0.48Sb1.52Te3 alloy by a hot-pressing texture method along the axial direction of a zone-melted ingot. It is found that a plastic deformation of grain refinement and rearrangement occurs during the textured pressing process. Although the obtained power factor is slightly decreased, a large amount of grain boundaries emerges in the textured samples and dense dislocations are observed around the boundaries and inside the grains. These additional phonon scattering centers can effectively scatter the low- and mid-frequency phonons, and the corresponding lattice thermal conductivity is significantly reduced to only 50% of that of zone-melted samples. Consequently, the maximum figure of merit (ZT) reaches 1.44 at 330 K and the average ZT (300-380 K) reaches 1.38. This study suggests that the simple hot-pressing texture technique is a promising method to significantly optimize the cooling capacity of Bi0.48Sb1.52Te3-based thermoelectric refrigeration.

Near and Mid-Infrared Emission Characteristics of Er³âº/Tm³âº/Ho³âº-Doped LiYF4 Single Crystals Excited by Laser Diode.

Yttrium lithium fluoride (LiYF4) single crystals triply doped with Er³âº/Tm³âº/Ho³âº are synthesized by a vertical Bridgman method. Absorption spectra, emission spectra, and decay curves are measured to investigate the luminescent properties of the crystals. Compared with Er³âº singly doped and Er³âº/Tm³âº and Er³âº/Ho³âº doubly doped LiYF4 crystals, an intense emission around 2.7 µm can be obtained in the triply doped LiYF4 crystal under excitation of 980 nm laser diode. Meanwhile, the near infrared emission at 1.5 µm from Er³âº in the triply doped crystal is effectively reduced. The possible energy transfer processes and the luminescent mechanisms for enhancing emission at 2.7 µm and quenching emission at 1.5 µm in the Er³âº/Ho³âº/Tm³âº triply doped crystals are proposed. The large energy transfer efficiency of 82.0% and excellent optical transmission indicate that this Er³âº/Tm³âº/Ho³âº triply doped crystal can be considered as a promising material for a mid- infrared laser at 2.7 µm.