Fluoropolymer ferroelectrics: Multifunctional platform for polar-structured energy conversion.

Ferroelectric materials are currently some of the most widely applied material systems and are constantly generating improved functions with higher efficiencies. Advancements in poly(vinylidene fluoride) (PVDF)-based polymer ferroelectrics provide flexural, coupling-efficient, and multifunctional material platforms for applications that demand portable, lightweight, wearable, and durable features. We highlight the recent advances in fluoropolymer ferroelectrics, their energetic cross-coupling effects, and emerging technologies, including wearable, highly efficient electromechanical actuators and sensors, electrocaloric refrigeration, and dielectric devices. These developments reveal that the molecular and nanostructure manipulations of the polarization-field interactions, through facile defect biasing, could introduce enhancements in the physical effects that would enable the realization of multisensory and multifunctional wearables for the emerging immersive virtual world and smart systems for a sustainable future.

Suanzaoren Decoction for the treatment of chronic insomnia: a systematic review and meta-analysis.

OBJECTIVE: Suanzaoren decoction (SZRD) in Traditional Chinese Medicine is a common prescription for chronic insomnia. This study systematically and accurately evaluated the safety and efficacy of SZRD in the treatment of chronic insomnia, thus providing a reference for its clinical application. MATERIALS AND METHODS: From the establishment of the corresponding database until May 2022, we systematically queried EMbase, PubMed, Cochrane Library, Web of Science, CNKI, VIP, and Wanfang Database. Randomized control trials (RCTs) were included in this study, and the results that qualified for inclusion were screened and cross-checked by two researchers. After the relevant data were extracted, a meta-analysis was performed using RevMan 5.3 software. RESULTS: A total of 1,311 patients with chronic insomnia from 12 RCTs were enrolled in the meta-analysis, showing that the use of SZRD alone or in combination was superior to the control group in improving the clinical effective rate (RR=1.22, 95%CI [1.16, 1.29], p<0.00001), reducing the recurrence rate (RR=0.47, 95%CI [0.28, 0.80], p=0.005), and lowering the Pittsburgh Sleep Quality Index (PSQI) scores (MDSZRD+WM=-3.35,95%CI [-5.22, -1.47], p<0.00001); (MDSZRD=-1.94, 95%CI [-3.80, -0.07], p = 0.04). SZRD also could reduce the adverse effects rate (RR=0.30, 95% CI [0.22, 0.40], p<0.00001). CONCLUSIONS: It was therefore concluded that SZRD alone or in combination with Western medicine can increase the clinical effective rate, reduce the recurrence rate, improve the quality of life of chronic insomnia patients, and decrease the incidence of adverse effects. However, studies included in this analysis varied in quality, and more large-sample, high-quality, multi-center RCTs are still needed to verify the above conclusions.

Relaxor ferroelectric polymer exhibits ultrahigh electromechanical coupling at low electric field.

Electromechanical (EM) coupling-the conversion of energy between electric and mechanical forms-in ferroelectrics has been used for a broad range of applications. Ferroelectric polymers have weak EM coupling that severely limits their usefulness for applications. We introduced a small amount of fluorinated alkyne (FA) monomers (<2 mol %) in relaxor ferroelectric poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) (PVDF-TrFE-CFE) terpolymer that markedly enhances the polarization change with strong EM coupling while suppressing other polarization changes that do not contribute to it. Under a low-dc bias field of 40 megavolts per meter, the relaxor tetrapolymer has an EM coupling factor (k33) of 88% and a piezoelectric coefficient (d33) >1000 picometers per volt. These values make this solution-processed polymer competitive with ceramic oxide piezoelectrics, with the potential for use in distinct applications.

MicroRNA-802 promotes the progression of osteosarcoma through targeting p27 and activating PI3K/AKT pathway.

PURPOSE: Increasing evidences suggest dysfunctions of microRNAs (miRNAs) are playing important part in tumors. Therefore, the role of miR-802 in osteosarcoma (OS) was exploited. The object was to evaluate the effect of miR-802 and verify its influence on p27 Kip1 (p27) in OS. METHODS: RT-qPCR experiment was used to detect miR-802 and p27 expression in OS tissues and cells. We explored the function of miR-802 through Transwell assays. The phosphoinositide 3-kinase (PI3K)/AKT serine/threonine kinase pathway and epithelial-mesenchymal transition (EMT) was detected by Western blot assays. Luciferase assay was used to testify the target of miR-802. RESULTS: MiR-802 expression was elevated in OS, which was related to poor clinical outcome in OS patients. MiR-802 overexpression promoted OS migration, invasion and EMT. Further, p27 is a direct target of miR-802. P27 elevation counteracted the promotion effect of OS on EMT, migration and invasion induced by miR-802. In addition, miR-802 overexpression inactivated PI3K/AKT pathway via targeting p27 in OS. CONCLUSION: MiR-802 promoted the progress of EMT, migration and invasion in OS via targeting p27. This newly identified miR-802/p27/PI3K/AKT axis may represent potential targets for OS.

High-entropy polymer produces a giant electrocaloric effect at low fields.

More than a decade of research on the electrocaloric (EC) effect has resulted in EC materials and EC multilayer chips that satisfy a minimum EC temperature change of 5 K required for caloric heat pumps1-3. However, these EC temperature changes are generated through the application of high electric fields4-8 (close to their dielectric breakdown strengths), which result in rapid degradation and fatigue of EC performance. Here we report a class of EC polymer that exhibits an EC entropy change of 37.5 J kg-1 K-1 and a temperature change of 7.5 K under 50 MV m-1, a 275% enhancement over the state-of-the-art EC polymers under the same field strength. We show that converting a small number of the chlorofluoroethylene groups in poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) terpolymer into covalent double bonds markedly increases the number of the polar entities and enhances the polar-nonpolar interfacial areas of the polymer. The polar phases in the polymer adopt a loosely correlated, high-entropy state with a low energy barrier for electric-field-induced switching. The polymer maintains performance for more than one million cycles at the low fields necessary for practical EC cooling applications, suggesting that this strategy may yield materials suitable for use in caloric heat pumps.

Hydrogel Ionic Diodes toward Harvesting Ultralow-Frequency Mechanical Energy.

Energy harvesting from human motion is regarded as a promising protocol for powering portable electronics, biomedical devices, and smart objects of the Internet of things. However, state-of-the-art mechanical-energy-harvesting devices generally operate at frequencies (>10 Hz) well beyond human activity frequencies. Here, a hydrogel ionic diode formed by the layered structures of anionic and cationic ionomers in hydrogels is presented. As confirmed by finite element analysis, the underlying mechanism of the hydrogel ionic diode involves the formation of the depletion region by mobile cations and anions and the subsequent increase of the built-in potential across the depletion region in response to mechanical pressure. Owing to the enhanced ionic rectification ratio by the embedded carbon nanotube and silver nanowire electrodes, the hydrogel ionic diode exhibits a power density of ≈5 mW cm-2 and a charge density of ≈4 mC cm-2 at 0.01 Hz, outperforming the current energy-harvesting devices by several orders of magnitude. The applications of the self-powered hydrogel ionic diode to tactile sensing, pressure imaging, and touchpads are demonstrated, with sensing limitation is as low as 0.01 kPa. This work is expected to open up new opportunities for ionic-current-based ionotronics in electronics and energy devices.

Morphology-induced dielectric enhancement in polymer nanocomposites.

The mechanism of the recently discovered enhancement of dielectric properties in dilute polymer-nanoparticle composites is investigated by experiments and computer simulations. We show that the weakening of the hydrogen bonds between the nanoparticles and the polymer chains reduces the polymer-nanoparticle composite's dielectric enhancement. The subsequent multiscale simulations investigate the attachment of solvated highly dipolar polymers to oxide nanoparticles, which leads to deposition of nanoparticle-polymer blobs during solution casting and a reduced density compared to a neat polymer film. Coarse-grained simulations of nanocomposite morphology are followed by molecular dynamics and density functional theory calculations of permittivities. The increased free volume in the nanocomposite enables easier reorientation of monomer dipoles with an applied electric field, and thus a higher dielectric permittivity. The numerical results are in excellent agreement with experimental data for PEEU and PEI nanocomposites.

Improving electric thermal stability of polypropylene by chemically linking small amount of hindered phenol groups.

Thermal stability of polypropylene (PP) over a broad temperature is critical for many applications. Hindered phenol (HP) groups have been utilized in PP for thermal-oxidative protection. This paper studies thermal stability of the electret property of PP linked with 0.2 mol% HP. It is observed that small amount of chemically linked HP groups improves electret thermal stability as reflected by the higher peak temperature of the thermally stimulated discharge curve and about 65% increase in the trap level. In addition, the HP groups in PP generate "rigid backbones" which maintain the PP film shapes to temperatures near the melting (~ 150 °C), compared with pristine PP at 70 °C. SUPPLEMENTARY INFORMATION: The online version of this article (10.1557/s43580-021-00016-1) contains supplementary material, which is available to authorized users.

Analysis of altered miRNA profiling in the colon of a mouse model with ß-lactoglobulin allergy.

OBJECTIVES: The differences in the expression profiles of colonic miRNAs between ß-lactoglobulin (ß-Lg) allergic mice and normal mice were analyzed to investigate the important role of the miRNA regulation mechanism in the pathogenesis of cow's milk allergy. METHODS: The present study performed Illumina sequencing to characterize the miRNA profile changes in mouse colon responding to ß-Lg challenge. Target genes were predicted by TargetScan 50 and miRanda 3.3a algorithms and assessed by GO and KEGG analysis. The expression levels of selected miRNAs and cytokine production were verified by cell transfection and quantitative RT-PCR. RESULTS: A total of 15 miRNAs were diversely expressed between the colon of the normal and ß-Lg-sensitized mice (P < 0.05, fold change of >1.50 or <0.67), including six up-regulated miRNAs and nine down-regulated miRNAs, among which seven miRNAs were validated using qRT-PCR. GO enrichment and KEGG pathway analyses further revealed that biological process, protein binding, cytoplasm and the pathways of cancer were significantly enriched, which were closely connected to the allergic inflammation development. Additionally, six key functional interaction pairs in ß-Lg allergy were identified in miRNA prediction algorithms and verified using qRT-PCR. CONCLUSIONS: We can conclude that our results suggested that the miRNAs regulation network participated in the pathogenesis of cow's milk allergy.

Creating an Eco-Friendly Building Coating with Smart Subambient Radiative Cooling.

Subambient daytime radiative cooling (SDRC) provides a promising electricity- and cryogen-free pathway for global energy-efficiency. However, current SDRC systems require stringent surface designs, which are neither cost-effective nor eco-friendly, to selectively emit thermal radiation to outer space and simultaneously maximize solar reflectance. Here, a generic method is developed to upgrade the conventional building-coating materials with a peculiar self-adaptive SDRC effect through combining particle scattering, sunlight-excited fluorescence, and mid-infrared broadband radiation. It is also theoretically proved that heat exchange with the sky can eliminate the use of resonant microstructures and noble metal mirrors in conventional SDRC, and also leads to enhanced daytime cooling yet suppressed nighttime overcooling. When exposed to direct sunlight, the upgraded coating over an aluminum plate can achieve 6 °C (7 °C on a scale-model building) below the ambient temperature under a solar intensity of 744 W m-2 (850 W m-2 ), yielding a cooling power of 84.2 W m-2 . The results pave the way for practical large-scale applications of high-performance SDRC for human thermal comfort in buildings.

Room Temperature Magnetoelectric Sensor Arrays For Application of Detecting Iron Profiles in Organs.

Noninvasive measurement of liver iron concentration (LIC) is clinically important. Yet, at the present time, it can only be achieved with SQUID technology. However, SQUID based BLS suffers high costs and cumbersome cryogenic requirements that prevent SQUID BLS from being adopted by clinical applications. Recently, we demonstrated that a single channel ME sensor with piezo-single crystals could detect LIC from only 3cc of mouse liver tissue without any magnetic field shielding. The results demonstrated not only the sensitivity of ME sensor system for LIC but also the feasibility for mapping LIC profiles spatially. This investigation further developed ME sensor arrays, exploiting the compact size and room temperature operation. A Dual-Channel 1-D ME sensor array along the vertical, Z-direction, was developed and shown to be sensitive to the skin-liver distance change which can be utilized to calibrate and eliminate the inter-subject variability of the LIC measurement due to skin-liver distance. With phantom having spatially dependent iron concentrations, the 1-D ME sensor array was capable of mapping the one-dimensional profile of the iron concentration in the horizontal X- and Y-directions. The results of the prototype sensor devices show the feasibility of an array ME-sensors for imaging iron profile.

A highly scalable dielectric metamaterial with superior capacitor performance over a broad temperature.

Although many polymers exhibit excellent dielectric performance including high energy density with high efficiency at room temperature, their electric and dielectric performance deteriorates at high temperatures (~150°C). Here, we show that nanofillers at very low volume content in a high-temperature (high-glass transition temperature) semicrystalline dipolar polymer, poly(arylene ether urea), can generate local structural changes, leading to a marked increase in both dielectric constant and breakdown field, and substantially reduce conduction losses at high electric fields and over a broad temperature range. Consequently, the polymer with a low nanofiller loading (0.2 volume %) generates a high discharged energy density of ca. 5 J/cm3 with high efficiency at 150°C. The experimental data reveal microstructure changes in the nanocomposites, which, at 0.2 volume % nanofiller loading, reduce constraints on dipole motions locally in the glassy state of the polymer, reduce the mean free path for the mobile charges, and enhance the deep trap level.

[Clinical characteristics and risk factors analysis of intracranial and extracranial arterial dissection].

Objective: To compare and analyze the clinical features and potential risk factors of intracranial and extracranial arterial dissection. Methods: A total of 241 consecutive patients with cervicocerebral artery dissection (CAD) in the First Affiliated Hospital of Zhengzhou University from 2010 to 2019 were observed. The 241 CAD patients were divided into extracranial artery dissection group (EAD) (n=81) and intracranial artery dissection group (IAD) (n=160), clinical characteristics and risk factors were compared between the two groups. Results: Compared with EAD, the National Institute of Health Stroke Scale (NIHSS) score was higher in patients with ischemic stroke in the IAD group (P=0.015). Patients with IAD were more likely to present with headache (58.8% vs 37.0%, P<0.001), and dissection Aneurysms (76.3% vs 38.3%, P<0.001). Patients with EAD more likely to have a history of mild head and neck injuries (11.1% vs 4.4%, P=0.047) and often involved the anterior circulation (77.8% vs 20.0%, P<0.001). Multivariate Logistic regression analysis showed differences in a history of minor head and neck trauma (OR=3.53, 95%CI 1.04-11.97, P=0.042), anterior circulation involvement (OR=0.09, 95%CI 0.05-0.19, P<0.001), dissection aneurysms (OR=4.98, 95%CI 2.80-8.84, P<0.001), headache (OR=2.42, 95%CI 1.39-4.20, P=0.002) remained significant, and the NHISS score lost its significance. Conclusions: EAD often involves the anterior circulation and a history of mild injury to the head and neck. IAD is more prone to exhibit headache symptoms, and it is more likely to form a dissection aneurysm, and the symptoms of ischemic stroke are more severe.

Modulation effect of Lactobacillus acidophilus KLDS 1.0738 on gut microbiota and TLR4 expression in ß-lactoglobulin-induced allergic mice model.

OBJECTIVES: ß-lactoglobulin (ß-Lg)-sensitized mice model was employed to investigate the correlation between Lactobacillus acidophilus KLDS 1.0738 (Lap KLDS 1.0738) modulating gut microbiota and inducting Toll-like receptors (TLRs) expression. METHODS: The alterations of mice fecal microbiota were analyzed by 16S rRNA gene sequencing. The serum cytokines production and TLR4/NF-κB mRNA expression in the colon tissues were measured by ELISA kit and quantitative RT-PCR, respectively. RESULTS: The results showed that Lap KLDS 1.0738 pretreatment attenuated ß-Lg-induced hypersensitivity, accompanied with a diminished expression of TLR4/NF-κB signaling. Moreover, oral administration of Lap KLDS 1.0738 improved the richness and diversity of fecal microbiota, which was characterized by fewer Proteobacteria phylum and Helicobacteraceae family, and higher Firmicutes phylum and Lachnospiraceae family than allergic group. Notably, TLR4/NF-κB expression was positively correlated with the family of Helicobacteraceae in allergic group, but negatively correlated with the family of Lachnospiraceae, Ruminococcaceae and anti-inflammatory cytokines level. A significant positive correlation was observed between TLR4/NF-κB expression and the production of histamine, total IgE and pro-inflammatory cytokines. CONCLUSIONS: Intake of Lap KLDS 1.0738 can influence the gut bacterial composition, which might result in recognizing TLRs signaling so as to inhibit allergic response.

[Impact of diagnostic ureteroscopy and biopsy on radical nephroureterectomy of upper tract urothelial carcinoma].

OBJECTIVE: To investigate the impact of preoperative diagnostic ureteroscopy and biopsy (UB) on radical nephroureterectomy (RNU) and the prognosis of upper tract urothelial carcinoma (UTUC). METHODS: The clinical data of UTUC patients receiving RNU between Jan. 2007 and Dec. 2016 were retrospectively collected. The median follow up time was 40 months. The operation time and blood loss of RNU were compared between UB group and non-UB group. Subgroup analyses were conducted according to the time interval between UB and RNU, and surgery methods of lower ureter. The linear regression model was used to adjust for other common factors that impacted operation time. RESULTS: A total of 163 UTUC patients were included in the final analysis. For the lower ureter, open ureterectomies were performed in 91 patients (55.9%), while retroperitoneal laparoscopic ureterectomies were performed in 72 patients (44.1%). A total of 110 (67.5%) patients received preoperative UB. Compared with non-UB group, the average operation time of UB group was significantly longer [(252.5±79.8) min vs. (221.3±79.8) min, P=0.019], but no difference of blood loss was found (median, 50 mL vs. 50 mL, P=0.143). In subgroup analysis, the average operation time of RNU was significantly prolonged when RNU was performed after 1 week of UB (P=0.023). Meanwhile, the median blood loss of RNU increased significantly when it was done after 2 weeks of UB compared with non-UB group (100 mL vs. 50 mL, P=0.012). UB was also significantly prolonged the operation time of RNU in retroperitoneal laparoscopic ureterectomy group (P=0.012). In multivariable analysis, UB (P=0.049), ≥pT3 (P=0.039), pN+ (P=0.018) and ureterectomy method (P=0.005) were independent risk factors of prolonged operation time. The 3-year cancer specific survival (CSS) rate was 87.2% in our cohort. UB had no significant impact on cancer specific survival (P=0.435). CONCLUSION: UB was an independent risk factor of prolonged RNU time, but did not significantly influence cancer specific survival of upper tract urothelial carcinoma patients.

[Perioperative management of endoscopic ear surgery].

With the rapid development of modern equipment and widespread familiarity with the relative knowledge, endoscopic ear surgery has attracted many oto-surgeons and is becoming more popular in primary hospitals in China. Standardized management of perioperative period in this field can help surgeons shorten the learning curve and avoid potential complications in endoscopic ear surgery. In this article, the management technique was introduced in detail, covering five main aspects including handling of related in-struments, preoperative examination and preparation, informed consent, preparation for patients and operation room setup. Extra focus was placed on the manipulation and resolution of possible difficulties during the procedure.

A Novel Magnetoelectric Biomagnetic Susceptometer on Iron Level Detection with Mice Tissue in Vitro.

Iron plays a vital role in human body. Liver Iron Concentration (LIC) is directly correlated to total body iron and can be an important indicator to a variety of pathologies. Non-invasive methods to quantitatively assess tissue iron with low cost and high sensitivity have drawn vast interests and investments. Among various methods, the magnetoelectric (ME) sensor based biomagnetic liver susceptometer (BLS) is of great promise because it operates at room temperature but with the same principle as that of the well-developed SQUID (Superconducting Quantum Interference Device). Here, we report a magnetoelectric (ME) sensor based BLS system exploiting the recently developed PIN-PMN-PT piezoelectric single crystal. The newly developed ME BLS, which employs the horizontal scanning mechanism with a water bath interface to automatically eliminate the diamagnetic background of the tissues and irregular shape of torso, exhibits an overall sensitivity advancement (300X) to the sensor system previously reported. A linear correlation (R2 = 0.97) found between the system measurements and the biopsy data demonstrates the validity of the system. The ability to detect signals from only 3cc of mouse liver tissue samples suggests a high spatial resolution which could be used for finer scanning and enable magnetic distribution image and profiling.

Enhancement of the dielectric response in polymer nanocomposites with low dielectric constant fillers.

In order to increase the dielectric constants of polymer-based dielectrics, composite approaches, in which inorganic fillers with much higher dielectric constants are added to the polar polymer matrix, have been investigated. However, high dielectric constant fillers cause high local electric fields in the polymer, resulting in a large reduction of the electric breakdown strength. We show that a significant increase in the dielectric constant can be achieved in polyetherimide nanocomposites with nanofillers whose dielectric constant can be similar to that of the matrix. The presence of nanofillers reduces the constraints on the dipole response to the applied electric field, thus enhancing the dielectric constant. Our results demonstrate that through nanostructure engineering, the dielectric constant of nanocomposites can be enhanced markedly without using high dielectric constant nanofillers.

Decreased expression of miR-490-3p in osteosarcoma and its clinical significance.

OBJECTIVE: Increasing evidence has revealed that miRNAs play a key role in the development and progression of tumor and are being explored as a prognostic biomarker. The aim of this study was to investigate the clinical significance of miR-490-3p expression in osteosarcoma. PATIENTS AND METHODS: Quantitative real-time PCR (qRT-PCR) was used to evaluate miR-490-3p level in osteosarcoma tissues. We also analyzed the correlations between the expression level of miR-490-3p and the clinical characteristics in cases of osteosarcoma. Also, Kaplan-Meier curve and the log-rank test were conducted to detect the prognostic value of miR-490-3p. Finally, univariable and multivariable Cox regression analyses were used to evaluate independent prognostic factors. RESULTS: MiR-490-3p expression level was significantly downregulated in osteosarcoma tissues in comparison with noncancerous bone tissues. Moreover, low miR-490-3p expression was significantly associated with distant metastasis, advanced clinical stage and poor overall survival and relapse-free survival. Univariate and multivariate analysis results indicated that miR-490-3p was an independent prognostic factor in osteosarcoma. CONCLUSIONS: Our results showed that miR-490-3p plays critical roles in osteosarcoma progression and serves as a novel prognostic indicator and a potential therapeutic target for osteosarcoma.