Boosting the thermoelectric performance of p-type heavily Cu-doped polycrystalline SnSe via inducing intensive crystal imperfections and defect phonon scattering

In this study, we, for the first time, report a high Cu solubility of 11.8% in single crystal SnSe microbelts synthesized via a facile solvothermal route. The pellets sintered from these heavily Cu-doped microbelts show a high power factor of 5.57 μW cm−1 K−2 and low thermal conductivity of 0.32 W m−1 K−1 at 823 K, contributing to a high peak ZT of ∼1.41. Through a combination of detailed structural and chemical characterizations, we found that with increasing the Cu doping level, the morphology of the synthesized Sn1−xCuxSe (x is from 0 to 0.118) transfers from rectangular microplate to microbelt. The high electrical transport performance comes from the obtained Cu+ doped state, and the intensive crystal imperfections such as dislocations, lattice distortions, and strains, play key roles in keeping low thermal conductivity. This study fills in the gaps of the existing knowledge concerning the doping mechanisms of Cu in SnSe systems, and provides a new strategy to achieve high thermoelectric performance in SnSe-based thermoelectric materials

Uygur Autonomous Region Research

Abstract: Related HLA-haploidentical HSCT has been applied more and more recently, but the reconstitution of T lymphocyte subsets and its clinical significance in patients received related HLA-haploidentical non T-cell depleted in vitro high-dose peripheral blood hematopoietic SCT (RHNT-PSCT) are incompletely defined. In the present study of our RHNT-PSCT, we found that in non-aGVHD group, CD3 + T lymphocyte recovered to normal levels gradually between 60 and 90 days, and the recovery of CD4 + T lymphocyte was retarded significantly, CD4 + /CD8 + ratio was apparently inverted. Whereas, the ratio of CD4 + CD25 + Foxp3 + Treg cells was significantly lower in aGVHD group than in healthy control group and non-aGVHD group, and also in grade III-IV aGVHD patients than in grade I-II aGVHD patients. Meanwhile, we observed the level of interleukin-10 (IL-10) gradually increased in serum of patients without aGVHD, but decreased in III-IV aGVHD patients significantly. Spearman correlation analysis showed that serum IL-10 level was negatively correlated with the grade of aGVHD. These results suggest that the reconstitution of peripheral blood T lymphocyte subsets is good, and dynamic detection of Treg cells and serum IL-10 level might predict aGVHD in the early stage after our RHNT-PSCT

Correction: Computer-aided design of high-efficiency GeTe-based thermoelectric devices

Correction for ‘Computer-aided design of high-efficiency GeTe-based thermoelectric devices’ by Min Hong et al., Energy Environ. Sci., 2020, DOI: 10.1039/d0ee01004a. The authors regret errors in the author affiliations in the original manuscript. The corrected list of authors and affiliations for this paper is as shown above. The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers

Effects of plasma and gas flow conditions on the structures and photoluminescence of carbon nanomaterials

In this work, we demonstrate the conversion of amorphous to crystalline carbon nanomaterials through the synthesis of carbon nanomaterials on silicon substrates coated with gold films in CH4-N2-H2 environment and CH4-N2-H2 plasma by hot filament chemical vapor deposition, respectively. The characterization results indicate that the flow rate of methane and plasma lead to the structural conversion and the change of composition of carbon nanomaterials, which are related to the conversion of hydrocarbon radicals to benzene molecules on the gold nanoparticles and the incorporation of nitrogen in the carbon nanomaterials caused by the plasma. Furthermore, the isothermal absorption theory was applied to study the structural conversion of amorphous to crystalline carbon nanomaterials in the CH4-N2-H2 plasma. The studies suggest that the change of surface tension caused by the dissolution of different carbon species in gold nanoparticles plays a key role for the structural conversion of the carbon nanomaterials. The photoluminescence properties of synthesized carbon nanomaterials were investigated at room temperature. The results exhibit that the carbon nanomaterials can generate the ultraviolet, blue, green and red light due to the functional groups on the surfaces of carbon nanomaterials and they are expected to emit white light after the functional groups are adjusted. The outcomes of this work are significant to control the structures of carbon nanomaterials and contribute the development of white light emission devices

Nanocarbon phase transformations controlled by solubility of carbon species in gold nanoparticles

The hybrid structures of carbon nanomaterials reveal the excellent properties and open new windows for the applications of carbon-based nanomaterials. However, the structural transformation of carbon nanomaterials should be better understood to design the new hybrid carbon nanomaterials. For this reason, we explore the growth of carbon nanorods composed of nanocrystalline graphite sheets and amorphous carbon nanoparticles by plasma enhanced hot filament chemical vapor deposition using Au film as the catalyst. The results indicate that the carbon nanorods are a hybrid structure of nanocrystalline graphite sheets and amorphous carbon nanoparticles formed via the large Au nanoparticles. The studies of transformation mechanism indicate that the solubility of C2 and C3 carbon species in the Au nanoparticles plays an important role in the conversion between graphite carbon and amorphous carbon. Moreover, the solubility of C, C2 and C3 carbon species in the Au nanoparticles can control the graphitic nanostructure and morphology. Furthermore, the study on the photoluminescence of carbon nanorods indicates the synthesized carbon nanorods emit the ultraviolet and green light at room temperature, which originates from the hydrocarbon radicals on the carbon nanorods and the transition between π* and π bands of sp2 carbon clusters in the carbon nanorods, respectively. The results enable us not only to control the structure of carbon nanomaterials but also develop the next-generation optoelectronic devices based on carbon nanomaterials

An Optimized Trichloroacetic Acid/Acetone Precipitation Method for Two-Dimensional Gel Electrophoresis Analysis of Qinchuan Cattle Longissimus Dorsi Muscle Containing High Proportion of Marbling.

Longissimus dorsi muscle (LD) proteomics provides a novel opportunity to reveal the molecular mechanism behind intramuscular fat deposition. Unfortunately, the vast amounts of lipids and nucleic acids in this tissue hampered LD proteomics analysis. Trichloroacetic acid (TCA)/acetone precipitation is a widely used method to remove contaminants from protein samples. However, the high speed centrifugation employed in this method produces hard precipitates, which restrict contaminant elimination and protein re-dissolution. To address the problem, the centrifugation precipitates were first grinded with a glass tissue grinder and then washed with 90% acetone (TCA/acetone-G-W) in the present study. According to our result, the treatment for solid precipitate facilitated non-protein contaminant removal and protein re-dissolution, ultimately improving two-dimensional gel electrophoresis (2-DE) analysis. Additionally, we also evaluated the effect of sample drying on 2-DE profile as well as protein yield. It was found that 30 min air-drying did not result in significant protein loss, but reduced horizontal streaking and smearing on 2-DE gel compared to 10 min. In summary, we developed an optimized TCA/acetone precipitation method for protein extraction of LD, in which the modifications improved the effectiveness of TCA/acetone method

Computer-aided design of high-efficiency GeTe-based thermoelectric devices

Driven by materials science development, the thermoelectric performance has been enhanced. However, only increasing the figure of merit to enhance the thermoelectric efficiency becomes more challenging. Here, we combine an enhanced figure of merit and geometry optimization of a device by computer-aided design to achieve a record-high thermoelectric efficiency of 16%. A figure of merit over 2.2 in p-type Ge1−x−yCrxSbyTe alloys is achieved resulting from the convergence of three valence edges induced by Cr doping to enhance the power factor and superlattice precipitates to lower the thermal conductivity. Using finite element analysis simulations, we optimize the geometry of a segmented thermoelectric device made of the as-developed Ge1−x−yCrxSbyTe and other reported materials, leading to a record high efficiency. Furthermore, our simulations on over 70 existing n-type thermoelectric materials can serve as a library to bridge the gap between materials science and device engineering to achieve high-efficiency thermoelectric devices

Chemoselective and Continuous Flow Hydrogenations in Thin Films Using a Palladium Nanoparticle Catalyst Embedded in Cellulose Paper

Cellulose immobilized palladium (0) nanoparticles (PdNPs) were prepared for the use in scalable catalytic reactions in flow. Preparation of the catalyst is remarkably simple and fast, where a palladium acetate solution is drop-casted onto cellulose paper and then exposed to 1 atm of hydrogen for a mere 90 s to produce embedded Pd(0) nanoparticles. This catalyst system is efficient in the hydrogenation of alkenes, nitroarenes, ketones, and enamides, with products formed in high yields, under ambient pressure and temperature. The system is also effective for transfer hydrogenation using ammonium formate as an alternative hydrogen source. A high catalyst stability and reusability are demonstrated along with the chemoselective and scalable synthesis of industrially important fine chemicals, including the biobased molecule cyrene

Acyltransferase zinc finger DHHC-type containing 2 aggravates gastric carcinoma growth by targeting Nrf2 signaling: A mechanism-based multicombination bionic nano-drug therapy

The significant regulatory role of palmitoylation modification in cancer-related targets has been demonstrated previously. However, the biological functions of Nrf2 in stomach cancer and whether the presence of Nrf2 palmitoylation affects gastric cancer (GC) progression and its treatment have not been reported. Several public datasets were used to look into the possible link between the amount of palmitoylated Nrf2 and the progression and its outcome of GC in patients. The palmitoylated Nrf2 levels in tumoral and peritumoral tissues from GC patients were also evaluated. Both loss-of-function and gain-of-function via transgenic experiments were performed to study the effects of palmitoylated Nrf2 on carcinogenesis and the pharmacological function of 2-bromopalmitate (2-BP) on the suppression of GC progression in vitro and in vitro. We discovered that Nrf2 was palmitoylated in the cytoplasmic domain, and this lipid posttranslational modification causes Nrf2 stabilization by inhibiting ubiquitination, delaying Nrf2 destruction via the proteasome and boosting nuclear translocation. Importantly, we also identify palmitoyltransferase zinc finger DHHC-type palmitoyltransferase 2 (DHHC2) as the primary acetyltransferase required for the palmitoylated Nrf2 and indicate that the suppression of Nrf2 palmitoylation via 2-bromopalmitate (2-BP), or the knockdown of DHHC2, promotes anti-cancer immunity in vitro and in mice model-bearing xenografts. Of note, based on the antineoplastic mechanism of 2-BP, a novel anti-tumor drug delivery system ground 2-BP and oxaliplatin (OXA) dual-loading gold nanorods (GNRs) with tumor cell membrane coating biomimetic nanoparticles (CM@GNRs-BO) was established. In situ photothermal therapy is done using near-infrared (NIR) laser irradiation to help release high-temperature-triggered drugs from the CM@GNRs-BO reservoir when needed. This is done to achieve photothermal/chemical synergistic therapy. Our findings show the influence and linkage of palmitoylated Nrf2 with tumoral and peritumoral tissues in GC patients, the underlying mechanism of palmitoylated Nrf2 in GC progression, and novel possible techniques for addressing Nrf2-associated immune evasion in cancer growth. Furthermore, the bionic nanomedicine developed by us has the characteristics of dual drugs delivery, homologous tumor targeting, and photothermal and chemical synergistic therapy, and is expected to become a potential platform for cancer treatment

A synergy of strain loading and laser radiation in determining the high-performing electrical transports in the single Cu-doped SnSe microbelt

Semiconducting microbelts are key components of the thermoelectric micro-devices, and their electrical transport properties play significant roles in determining the thermoelectric performance. Here, we report heavily Cu-doped single-crystal SnSe microbelts as potential candidates employed in thermoelectric micro-devices, fabricated by a facile solvothermal route. The considerable Cu-doping concentration of ∼11.8 % up to the solubility contributes to a high electrical conductivity of ∼416.6 S m-1 at room temperature, improved by one order of magnitude compared with pure SnSe (38.0 S m-1). Meanwhile, after loading ∼1 % compressive strain and laser radiation, the electrical conductivity can be further improved to ∼601.9 S m-1 and ∼589.2 S m-1, respectively, indicating great potentials for applying to thermoelectric micro-devices. Comprehensive structural and compositional characterizations indicate that the Cu+ doping state provides more hole carriers into the system, contributing to the outstanding electrical conductivity. Calculations based on first-principle density functional theory reveal that the heavily doped Cu lowers the Fermi level down into the valence bands, generating holes, and the 1 % strain can further reduce the bandgap, strengthening the ability to release holes, and, in turn, leading to such an excellent electrical transport performance. This study fills the gaps of finding novel materials as potential candidates employed in the thermoelectric micro-devices and provides new ideas for micro/nanoscale thermoelectric material design