Search

To prospectively investigate the nocturnal bladder function and sleep in children with refractory primary monosymptomatic nocturnal enuresis (RPMNE). Fifty-three children diagnosed with RPMNE and 30 controls who had upper urinary tract abnormality but without any voiding problems were included in the study. RPMNE patients underwent a standardized investigation protocol, including the Pittsburgh Sleep Quality Index (PSQI) questionnaire, a 7-day bladder diary, and the simultaneous ambulatory urodynamic monitoring and polysomnography (PSG); controls were evaluated using the PSQI questionnaire and PSG. The children with RPMNE were subdivided into the nocturnal detrusor overactivity (NDO) case group and the non-NDO case group. The children in the NDO case group had a higher percentage of total sleep time in light sleep and a lower percentage in the N3 sleep stage than those in the non-NDO case group and control group (P <.05). The cortical arousal index and PSQI scores of both RPMNE subgroups were higher compared to the control group (P <.05). The incidences of reduced nocturnal bladder capacity (NBC) in the NDO case group were higher than in the non-NDO case group (P <.05). The frequency of involuntary detrusor contractions during sleep was positively correlated with cortical arousal index in the NDO case group (r = 0.811, P <.0001). In addition to the reduced NBC, the RPMNE is related to abnormal NDO, increased light sleep period, and cortical arousal dysfunction. Moreover, there is a certain correlation between the abnormal degrees of NDO and cortical arousal dysfunction. [ABSTRACT FROM AUTHOR]

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide and macrophage polarization plays an important role in its pathogenesis. However, which molecule regulates macrophage polarization in NAFLD remains unclear. Herein, we showed NAFLD mice exhibited increased 17 β -hydroxysteroid dehydrogenase type 7 (17 β -HSD7) expression in hepatic macrophages concomitantly with elevated M1 polarization. Single-cell RNA sequencing on hepatic non-parenchymal cells isolated from wild-type littermates and macrophage-17 β -HSD7 knockout mice fed with high fat diet (HFD) for 6 weeks revealed that lipid metabolism pathways were notably changed. Furthermore, 17 β -HSD7 deficiency in macrophages attenuated HFD-induced hepatic steatosis, insulin resistance and liver injury. Mechanistically, 17 β -HSD7 triggered NLRP3 inflammasome activation by increasing free cholesterol content, thereby promoting M1 polarization of macrophages and the secretion of pro-inflammatory cytokines. In addition, to help demonstrate that 17 β -HSD7 is a potential drug target for NAFLD, fenretinide was screened out from an FDA-approved drug library based on its 17 β -HSD7 dehydrogenase inhibitory activity. Fenretinide dose-dependently abrogated macrophage polarization and pro-inflammatory cytokines production, and subsequently inhibited fat deposition in hepatocytes co-cultured with macrophages. In conclusion, our findings suggest that blockade of 17 β -HSD7 signaling by fenretinide would be a drug repurposing strategy for NAFLD treatment. By increasing free cholesterol content, 17 β -HSD7 promotes NLRP3 inflammasome activation and M1 polarization, ultimately resulting in NAFLD. Moreover, fenretinide reduces M1 polarization and further hepatocytes lipid accumulation through inhibiting 17 β -HSD7. [Display omitted] [ABSTRACT FROM AUTHOR]

Bi 2 Te 3 based alloys have been the most widely used thermoelectric material at low temperature for many decades. Here we report Se doped n-type Mg 3 Bi 2 based materials with a thermoelectric figure-of-merit ZT of 0.82 at 300 K and a peak ZT of 1.24 at 498 K, which is comparable to the n-type Bi 2 Te 3 and Te doped Mg 3 Bi 1.4 Sb 0.6. The improved thermoelectric performance is benefited from the high carrier concentration and mobility as well as the thermal conductivity reduction. The reduced resistivity increased the power factor at all measured temperatures, leading to a higher engineering ZT (ZT eng) and engineering power factor (PF eng) for n-type Mg 3 Bi 2. The n-type Mg 3 Bi 1.4 Sb 0.6 materials are promising for thermoelectric power generation and cooling applications near room temperature. [ABSTRACT FROM AUTHOR]

Half-Heusler (HH) thermoelectric (TE) materials have been attracting extensive research interest over the last two decades, owing to their thermal stability, mechanical strength, and moderate ZT . This material system are potential candidates for medium to high temperature applications, which is close to the temperature range of most industrial waste heat sources. In this mini-review article, we briefly summarize the recent progress and advances in HH thermoelectric materials. Some effectively available approaches, such as HH nanocomposites to reduce thermal conductivity, using larger atomic mass and size differences to enhance phonon scattering to further reduce the thermal conductivity, forming ternary systems following the cost effective approach. In addition, new thermoelectric HH members are also discussed in this article, which points out that many new HH compounds may be possible for TE applications. [ABSTRACT FROM AUTHOR]

AgCuTe has been recognized as a promising thermoelectric material due to its reported ultralow lattice thermal conductivity, but its phase transition and unsatisfactory thermoelectric performance at close to room temperature restrict its application for the harvesting of low-grade heat. In this work, the near-room-temperature phase transition is successfully avoided by iodine doping at the Te site. In addition, iodine doping effectively reduces the hole concentration, thus greatly increasing the Seebeck coefficient and improving the average power factor, as well as reducing the electronic thermal conductivity. Consequently, a room-temperature ZT of ~0.35 and a maximum ZT of ~0.9 at 463 K were obtained in AgCuTe 0.9 I 0.1 , leading to a high average ZT of ~0.6 between 303 and 463 K. Our work paves a new way for realizing stable high performance in AgCuTe-based materials for thermoelectric applications. Image 1 • Phase transition was avoided near room temperature in iodine doped AgCuTe. • The hole concentration was reduced by doping iodine at the Te site. • The near-room-temperature ZT s and average ZT were enhanced greatly. [ABSTRACT FROM AUTHOR]

Because preparation circumstances are limited, the relationship between spherical porous zinc sulfide (ZnS) and cells is rarely investigated. Thus, using the hydrothermal approach, four different types of ZnS spheres with consistent size, high dispersion, and stability were created in this research by varying the temperature, duration, solvent ratio, and pH level of the hydrothermal process. Three structures are present in the generated particle spheres: solid, hollow, and mesoporous structures. In addition to causing a significant variation in the particle spheres' specific surface area, porosity, and surface roughness, the distinct architectures also have an impact on ZnS particle spheres' capacity to produce hydrogen sulfide (H 2 S) gas in an acidic environment. Experiments on hemolysis and cytotoxicity demonstrated that ZnS particle spheres with varying concentrations and shapes exhibited no cytotoxicity and good biocompatibility. According to cellular uptake trials, ZnS particle spheres with a rougher surface structure and a bigger specific surface area are more likely to be absorbed by macrophages and release more H 2 S gas. This activity of releasing H 2 S gas by H+ action and MA phagocytosis by employing ZnS as a donor lays the groundwork for later particles to load medicines and carry out biological functions. [ABSTRACT FROM AUTHOR]

• 1. A low-cost, safe and excellent photocatalytic method for the preparation of SnO 2 NPs/SnSe-NSS core-shell heterojunction was provided. • 2. SnO 2 NPs/SnSe-NSS core-shell heterojunction was prepared by two-step method. • 3. The effects of oxidation time and heat treatment temperature on SnO 2 NPs/SnSe-NSS core-shell heterojunction were discussed in detail. • 4. SnO 2 NPs/SnSe-NSS core-shell heterojunction composites have good photocatalytic activity for methylene blue aqueous solution under visible light. • 5. The possible mechanism of photodegradation of dyes in SnO 2 NPs/SnSe-NSS core-shell heterojunction composites is that ∙O 2 − is the main active material for photocatalytic degradation of methylene blue, followed by OH. Flower-like core-shell SnSe@SnO 2 was prepared by low-temperature in situ oxidation. The relationship between different oxidation times and the formation of core-shell structures of the samples was explored. The results showed that SnSe was obtained by thermal oxidation of SnO 2 in close contact with air. The size range of the flower-like core-shell structure SnSe@SnO 2 was 15–20 μm. The flower-like structure was self-assembled from nanoplates with a thickness of about 200 nm. This flower-like core-shell structured SnSe@SnO 2 has a band gap of about ∼1.4 eV. The electrochemical characterization of the samples was analyzed for charge transfer phenomena at the junctions as well as at the interface between the shell layer and the aqueous solution. The effect of different SnO 2 shell layers on the photocatalytic degradation activity of the composites for methylene blue was evaluated. The samples with SnSe oxidized in air for 8 h showed optimal photocatalytic performance and displayed excellent photostability and reusability. In addition, O 2 − was the main active species for the degradation of the organic dye methylene blue. [Display omitted] [ABSTRACT FROM AUTHOR]

In this work, we reported a simple synthesis of submicron α-Fe 2 O 3 with rod-like structure. When it evaluated as electrode material for lithium ion battery, comparing with Cu foil and Ni foam, the as-prepared α-Fe 2 O 3 electrodes with Cu foam current collector exhibited higher reversible capacity of 415 mAh g −1 and more stable cycle performance after 30 cycles. Comparative researches on electrochemical performances of the α-Fe 2 O 3 employing different current collectors (Cu foil, Cu foam and Ni foam) were discussed here in detail. According to our results, the improved electrochemical behaviors of α-Fe 2 O 3 electrode with Cu foam current collector could be attributed to its particular electrode structure, i.e., porous, good electric conductivity, closed adhere to the electrode materials. Just because of that, it may make sure an easy accessibility of electrolytes and fast transportation of lithium ions, importantly, it could avoid the active materials falling off from the current collector on account of volume expansion. [ABSTRACT FROM AUTHOR]

SnSe/SnO 2 @rGO composite photocatalyst was prepared using a simple in-situ selenization method. The structure, morphology, and properties of the material were characterized by X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and Brunauer–Emmett–Teller method. Moreover, the photocatalytic efficiency of the catalyst was evaluated on the aqueous solution of methylene blue under simulated natural light irradiation (wavelength >300 nm). After 120 min of degradation, the photocatalytic activity of SnSe/SnO 2 @rGO exceeded 90%. These results indicate that the heterojunction structure of SnSe/SnO 2 @rGO effectively promoted interfacial electron transfer and reduced the self-radiative recombination of charges, thereby improving the performance of the photocatalyst. Hence, the synthesized SnSe/SnO 2 @rGO possesses potential applications in the photocatalytic degradation of wastewater. • SnSe/SnO2@rGO heterojunctions were prepared by a one-step selenization method using Sn3O4 as raw material.. • rGO contributes to the decrease in band gap value of SnSe/SnO2@rGO and the increase in charge transfer capability. • The photocatalytic performance of SnSe/SnO 2 @rGO was improved by the synergistic effect of the multiphase interface.. • The photocatalytic degradation of MB by SnSe/SnO 2 @rGO composites was highly dependent on the generation of ∙OH. [ABSTRACT FROM AUTHOR]

Mg 2 (Ge, Sn) solid solutions are eco-friendly thermoelectric materials in moderate temperature (500–800 K) range. However, p-type Mg 2 (Ge, Sn) solid solutions show poor thermoelectric performance compared to the n-type counterpart. In this work, the filtering of low energy holes and the blocking of thermal excited electrons in Mg 1.92 Li 0.08 Ge 0.4 Sn 0.6 by Si addition are demonstrated, which optimize the power factor by interface barrier and reduce the lattice thermal conductivity by nanoscale composition fluctuation. Finally, the power factor of ~1.85 × 10−3 Wm−1 K−2 and the dimensionless figure of merit ZT ~0.75 are achieved in Li doped Mg 2 Ge 0.4 Sn 0.6 with Si addition at 723 K. When the band gap of matrix (E g1) is smaller than the band gap of second phase (E g2), the interface barriers in panel (a) may filter the low-energy holes while allowing the high-energy holes in the valence band (VB) before bipolar effect. Above thermal excited temperature, the energy barriers in panel (b) can filter the low-energy holes and simultaneously block the thermal excited electrons in the conduction band (CB) to suppress bipolar effect. Eventually, the results indicate that the power factor obviously increased and the thermal conductivity significantly decreased by the filtering of the low-energy holes and the blocking of the thermal excited electrons. Unlabelled Image [ABSTRACT FROM AUTHOR]

Mg(Sn,Si) and Mg(Sn,Ge) are promising n-type thermoelectric materials with good thermoelectric properties in the temperature range of 300–800 K. For power generation, similar thermoelectric performance of p-type materials is equally important. However, p-type material performance is much worse than the n-type, because achieving optimized carrier concentration has been difficult for the p-type Mg 2 X (X = Sn, Si). In this study we systematically compared the effect of the dopants Li, Na, and Ga and found that the highest carrier concentrations are achievable in Li-doped samples. Due to the relatively high content of Sn, carrier concentration of > 5 × 10 19 cm −3 were achieved for all dopants. Analysis of the transport data in the framework of a single parabolic band model showed similar and carrier concentration independent effective masses for all dopants. Our results therefore indicate a rigid band structure for p-type Mg 2 X for the studied dopants, in contrast to previous reports. Higher carrier mobilities have been achieved for Li-doped samples compared to the previous reports. Larger Hall mobilities leads to a higher peak power factor. Due to the higher carrier concentration, the onset of intrinsic excitations (bipolar effect) effectively shifts to higher temperature compared to the other two dopants, which results in a peak figure of merit of ∼0.5 at 723 K for Li doped samples. [ABSTRACT FROM AUTHOR]

The thermal reliability of Al-Si eutectic alloy as phase change materials (PCMs) was investigated through vacuum thermal cycling 250, 500, 750, and 1000 times going through the solid-liquid phase change. The changes in thermal properties of Al-Si eutectic alloy, including melting point, latent heat, specific heat, thermal diffusivity and thermal conductivity, were investigated using differential scanning calorimetric (DSC) and laser flash apparatus. The results revealed that, with increasing the number of cycles, the melting point and latent heat of fusion of the Al-Si eutectic alloy showed almost no changes. Moreover, the thermal conductivity showed an outstanding stability after 1000 thermal cycles. Therefore, it is concluded that the thermal reliability of Al-Si eutectic alloy is more than adequate for long-term performance as a phase change material for thermal energy storage (TES) applications. [ABSTRACT FROM AUTHOR]

A series of Nb doped (Hf 0.25 Zr 0.75 ) 1– x Nb x NiSn ( x = 0–0.03) samples were synthesized and studied by arc-melting the elements to first form ingots, then ball-milling the ingots to obtain fine powders, and finally hot-pressing the fine powder to form bulk samples. Instead of the conventional Sb doping on the Sn site of the n-type half-Heusler, it was found that Nb is also an effective dopant. When the carrier concentration is optimized at 2.2% Nb, a power factor of ∼47 μW cm −1 K −2 is achieved at and above 600 °C, and a peak ZT ∼0.9 is achieved at 700 °C with Nb doping from 1.8 at% to 2.2 at%. An output power density of ∼22 W cm −2 and a leg efficiency of ∼12% are calculated for the Nb doped samples. [ABSTRACT FROM AUTHOR]

We surprisingly made a new n-type thermoelectric compound NbCoSb with half-Heusler (HH) structure having valence electron count of 19, different from the traditional 18, which opens up a new route to develop new half-Heusler thermoelectric materials not following the traditional valence electron count of 18. The samples are made by arc melting followed by ball milling and hot pressing. The effect of hot pressing temperature on the thermoelectric properties of NbCoSb samples has been studied. A maximum thermoelectric figure-of-merit ( ZT ) of ∼0.4 is achieved at 700 °C in NbCoSb sample that is hot pressed at 1000 °C. This work add a new member to HH compounds for thermoelectric applications, although the peak ZT of ∼0.4 is still lower than that of the traditional HHs. Moreover, it is very interesting to see that a traditionally thought of valence electron counts of 18 is not required. [ABSTRACT FROM AUTHOR]

Good thermoelectric generators should ideally be realized by utilizing the same compounds in both p-type and n-type materials for achieving high energy conversion efficiency to drive the application. In this work, we enable a conduction transition from p-type to n-type in the YbMg 2 Sb 2 -based Zintl compounds via Mg vacancies compensation and cation site doping with Y. It is obviously demonstrated that Y is an effective electron donor to realize n-type conduction and increase the carrier concentration. By further Mg-doping in the Yb site, a significantly suppressed lattice thermal conductivity and noticeably enhanced power factor is obtained simultaneously. Thus, n-type YbMg 2 Sb 2 -based compounds with high power factor, low thermal conductivity, and high figure of merit are obtained. Our work broadens the family of n-type Zintl phase thermoelectric materials, demonstrating that the intrinsic defect chemistry and extrinsic doping are important approaches for such materials systems to achieve n-type conduction. [Display omitted] [ABSTRACT FROM AUTHOR]