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We conducted a comprehensive investigation on the influence of TiN thickness and stress on the ferroelectric properties of Hf 0.5 Zr 0.5 O 2 thin films. TiN top electrode layers with varying thicknesses of 2, 5, 10, 30, 50, 75, and 100 nm were deposited and analyzed. It was observed that the in-plane tensile stress in TiN films increased with the thickness of the TiN top electrode. This is expected to elevate the tensile stress in the Hf 0.5 Zr 0.5 O 2 film, consequently leading to an enhancement in ferroelectric polarization. However, the effect of stress on the ferroelectric behavior of Hf 0.5 Zr 0.5 O 2 films exhibited distinct stages: improvement, saturation, and degradation. Our study presents novel findings revealing a saturation and degradation phenomenon of in-plane tensile stress on the ferroelectric properties of polycrystalline Hf 0.5 Zr 0.5 O 2 films, thereby partially resolving the discrepancies between experimental observations and theoretical predictions. The observed phase transformation induced by tensile stress in Hf 0.5 Zr 0.5 O 2 films played a crucial role in these effects. Furthermore, we found that the impact of the TiN top electrode thickness on other factors influencing ferroelectricity, such as grain size and oxygen vacancies, was negligible. These comprehensive results offer valuable insights into the influence of stress and TiN top electrode thickness on the ferroelectric behavior of Hf 0.5 Zr 0.5 O 2 films. [ABSTRACT FROM AUTHOR]

Hf0.5Zr0.5O2 (HZO) is a promising candidate for low-power non-volatile memory due to its nanoscale ferroelectricity and compatibility with silicon-based technologies. Stress and oxygen vacancy (VO) are key factors that impact the ferroelectricity of HZO. However, their combined effects have not been extensively studied. In this study, we investigated the impact of the VO content on HZO thin films' ferroelectricity under different electrode stresses by using TiN and tungsten (W) top electrodes and controlling ozone dose time during HZO deposition. The HZO thin films with W top electrodes exhibit elevated stress levels and a greater abundance of orthorhombic/tetragonal phases, and the HZO thin films with TiN top electrode shows an increase in the monoclinic phase with increasing ozone dose time. The residual polarization (Pr) of the capacitors with TiN and W top electrodes displayed different or even opposing trends with increasing ozone dose time, and the VO content decreases with increasing ozone dose time for both sets of capacitor samples. We propose a model to explain these observations, considering the combined influence of electrode stresses and VO on the free and formation energy of the crystalline phase. Increasing the VO content promotes the transformation of the tetragonal phase to the orthorhombic phase in HZO films with TiN top electrodes, and with W top electrodes, a higher VO content prevents the tetragonal phase from transforming into the orthorhombic/monoclinic phase. Additionally, an alternative explanation is proposed solely from the perspective of stress. These findings provide valuable insights into the regulation of ferroelectricity in HZO thin films. [ABSTRACT FROM AUTHOR]

The ferroelectric field effect transistor (FeFET) is a very promising candidate for low-power and non-volatile memory. However, the co-existing effect of ferroelectric polarization and interface charge trapping in the FeFETs is demonstrated and many efforts have been made to eliminate this charge-trapping effect, which is usually treated as a deleterious effect. In contrast, we have found that the charge-trapping effect can play a dominant role in ferroelectric gates. In this work, we have verified that the charge-trapping effect of the ferroelectric/insulator interface could induce a memory window as the main physical mechanism in the TiN/Hf0.5Zr0.5O2/SiO2/p-Si (MFIS) structure, in which the ferroelectric characteristics of HZO thin films was verified through a reverse-grown MFIS structure. We also demonstrated that 2.5 nm SiO2 is optimal for the charge tunneling effect and the device has the largest memory window. Moreover, in order to enlarge the memory window of MFIS capacitors, we utilized the stress-enhanced ferroelectric polarization characteristics of Hf0.5Zr0.5O2 to improve the charge-trapping effect. Such a finding demonstrates that the ferroelectric-aided charge-trapping devices are potential to be used in non-volatile memories. [ABSTRACT FROM AUTHOR]

Background: Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have revolutionized the treatment of lung cancer patients with mutated EGFR. However, the efficacy of EGFR-TKIs in wild-type EGFR tumors has been shown to be marginal. Methods that can sensitize EGFR-TKIs to EGFR wild-type NSCLC remain rare. Hence, we determined whether combination treatment can maximize the therapeutic efficacy of EGFR-TKIs. Methods: We established a focused drug screening system to investigate candidates for overcoming the intrinsic resistance of wild-type EGFR NSCLC to EGFR-TKIs. Molecular docking assays and western blotting were used to identify the binding mode and blocking effect of the candidate compounds. Proliferation assays, analyses of drug interactions, colony formation assays, flow cytometry and nude mice xenograft models were used to determine the effects and investigate the molecular mechanism of the combination treatment. Results: Betulinic acid (BA) is effective at targeting EGFR and synergizes with EGFR-TKIs (gefitinib and osimertinib) preferentially against wild-type EGFR. BA showed inhibitory activity due to its interaction with the ATP-binding pocket of EGFR and dramatically enhanced the suppressive effects of EGFR-TKIs by blocking EGFR and modulating the EGFR-ATK-mTOR axis. Mechanistic studies revealed that the combination strategy activated EGFR-induced autophagic cell death and that the EGFR-AKT-mTOR signaling pathway was essential for completing autophagy and cell cycle arrest. Activation of the mTOR pathway or blockade of autophagy by specific chemical agents markedly attenuated the effect of cell cycle arrest. In vivo administration of the combination treatment caused marked tumor regression in the A549 xenografts. Conclusions: BA is a potential wild-type EGFR inhibitor that plays a critical role in sensitizing EGFR-TKI activity. BA combined with an EGFR-TKI effectively suppressed the proliferation and survival of intrinsically resistant lung cancer cells via the inhibition of EGFR as well as the induction of autophagy-related cell death, indicating that BA combined with an EGFR-TKI may be a potential therapeutic strategy for overcoming the primary resistance of wild-type EGFR-positive lung cancers. Highlights: 1. BA is a potent wild-type EGFR inhibitor. 2. BA enhances the anticancer efficacy of erlotinib/gefitinib in NSCLC patients with wild-type EGFR. 3. The combination of BA and gefitinib/osimertinib synergistically blocks EGFR and inhibits the PI3K-AKT-mTOR signaling pathway, leading to autophagic cell death and cell cycle arrest. 4. This combination strategy targets wild-type EGFR in NSCLC and induces autophagy and tumor suppression in vivo. BA, an EGFR inhibitor, sensitizes EGFR-TKIs' activity, indicating that BA plus EGFR-TKIs may be a potential therapeutic strategy to overcome the primary resistance of wild-type EGFR NSCLC. [ABSTRACT FROM AUTHOR]

Studying the energy use behavior of occupants is crucial for accurately predicting building energy consumption. However, few studies have considered the impact of occupant behaviors on energy consumption in university dormitories. The objective of this study is to establish an agent-based model of energy consumption for university dormitories based on energy use behavior. The dormitories of a typical university in Sichuan, China, were subdivided into three clusters using a two-step cluster analysis. Subsequently, the energy use behaviors of occupants in each type of dormitory were characterized to establish a stochastic energy use behavior model. On the basis of the above, NETLOGO was used to construct an agent-based model for dormitories' energy consumption to dynamically simulate energy use behavior. The accuracy of the model was verified by comparing the simulated values with the measured data. Finally, a building-energy-friendly retrofit scheme was proposed, and it was found that the optimized dormitory reduced energy consumption by 16.07%. Therefore, the results can provide information support for energy-saving decisions during the early design and retrofit phases of buildings. With the popularity of centralized supply, the research methodology may provide an extensive reference for energy management policies and sustainable strategies in the building sector. [ABSTRACT FROM AUTHOR]

Persistent luminescence is reported for a series of SrAl2O4 single crystals co-doped with 1.0 mol% Eu2O3 and (0.5–3.0 mol%) Nd2O3. Crystals were successfully grown under an Ar atmosphere in an optical floating zone furnace and consisted of a single phase with a monoclinic structure. The maximum intensity of the photoexcitation spectra (PLE) of all samples peaked at 421 nm. Under excitation at 421 nm, the photoluminescence (PL) spectra showed a broad emission in the visible region centered on 522 nm, which corresponds to the Eu2+ 4f65d1 → 4f7 transition, and three additional emissions in the near infrared region, corresponding to the 4F3/2 → 4I9/2 (880/907 nm), 4F3/2 → 4I11/2 (1062/1114 nm) and 4F3/2 → 4I13/2 (1332 nm) transitions from Nd3+. Thermoluminescence (TL) spectra showed that traps in the conduction band are shallower than that of the singly Eu-doped sample, and their concentration gradually increased with increasing Nd3+ content, reaching a maximum in the crystal prepared with 2.5 mol% Nd2O3. The lifetime of the afterglow decay curve also increased with increasing Nd3+ content of the crystals, reaching a maximum value of almost 35 seconds with 2.5 mol% Nd2O3. A mechanism for the long afterglow is proposed in which Eu2+ electrons are first excited, then transported through the conduction band to defect centers which function as traps (produced by Nd3+ doping), and the thermal energy at room temperature is sufficient to reverse this process, so that equilibrium is established and a long residual luminescence results. [ABSTRACT FROM AUTHOR]

Synthetic Ti-doped delafossite (CuFe1−xTixO2) was prepared by solid state reaction of Fe2O3, CuO and TiO2, and crystals were successfully prepared by the optical floating zone method using a modified experimental protocol that produced crystals in <10% of the time used in previous work. The effects of Ti on the microstructure and magnetic properties of CuFeO2 were investigated. The nonlinear change of cell size may be the result of Ti4+ reduction to Ti3+. However, the Fe oxidation state was not affected by Ti doping, although some oxidation of Cu+ to Cu2+ was observed with the highest Ti contents. The two characteristic magnetic transition temperatures of CuFeO2 occurred at 17 K (TN1) and 11 K (TN2) in the undoped crystal, and these increased to 51 K and 20 K, respectively, in the crystal with x = 0.007, although there was no major change in the two magnetic transition temperatures in crystals with other doping concentrations. In an applied magnetic field of 500 Oe, the magnetization of the x = 0.007 sample was 22 times that of CuFeO2, and its magnetization curve shows the coexistence of regions with ferrimagnetic and antiferromagnetic properties. Furthermore, magnetic hysteresis loops revealed that the saturation magnetization (M) of the sample x = 0.007 is 4.15 emu g−1, but at higher Ti concentrations the M–H curves returned to pairwise linear temperature dependence. Overall, crystals of synthetic delafossite with greatly affected magnetic properties can be prepared by doping with a limited range of Ti contents. [ABSTRACT FROM AUTHOR]

In this work, we point out that the major dilemma of image aesthetics assessment (IAA) comes from the abstract nature of aesthetic labels. That is, a vast variety of distinct contents can correspond to the same aesthetic label. On the one hand, during inference, the IAA model is required to relate various distinct contents to the same aesthetic label. On the other hand, when training, it would be hard for the IAA model to learn to distinguish different contents merely with the supervision from aesthetic labels, since aesthetic labels are not directly related to any specific content. To deal with this dilemma, we propose to distill knowledge on semantic patterns for a vast variety of image contents from multiple pre-trained object classification (POC) models to an IAA model. Expecting the combination of multiple POC models can provide sufficient knowledge on various image contents, the IAA model can easier learn to relate various distinct contents to a limited number of aesthetic labels. By supervising an end-to-end single-backbone IAA model with the distilled knowledge, the performance of the IAA model is significantly improved by 4.8% in SRCC compared to the version trained only with ground-truth aesthetic labels. On specific categories of images, the SRCC improvement brought by the proposed method can achieve up to 7.2%. Peer comparison also shows that our method outperforms 10 previous IAA methods. [ABSTRACT FROM AUTHOR]

Ethylene-co-vinyl acetate (EVA) is widely used in daily life and the development of its detection technology is very important. In this study, the thermal gravimetric analysis coupled with mass spectrometry (TGA-MS) was applied to develop a method for the direct quantitative analysis of EVA without further sample pretreatment. The degradation of EVA as measured by the combination of TGA with Fourier transform infrared spectrometer (FTIR) and gas chromatograph-mass spectrometer (GC/ MS) consists of three steps. The results show that a large amount of acetic acid produced in the deacetylation step of second stage can be clearly identified, while (CH)n fragments and acetone produced in this step. With the increase of pyrolysis temperature, benzene derivatives and large (CH2 ) fragments are detected. This indicates the chain scission reactions occurring at the end of the polymer main chain during deacetylation. Isothermal deacetylation reaction is monitored by MS which determines that the formation of ketones does not affect deacetylation. MS signal intensities of acetic acid linearly responding to EVA concentrations, therefore the quantitative analysis of EVA can be clearly identified by acetic acid. This method is easier operation and rapid to test the concentration of EVA, at the same time it can be a viable complement to existing methods. [ABSTRACT FROM AUTHOR]

In 3D NAND, as the stack number increases, the process cost becomes higher and higher, and the stress problem becomes more and more serious. Therefore, the low cost and low stress plasma enhanced tetraethyl orthosilicate (PE TEOS), compared to high density plasma (HDP) oxide, shows its superiority as pre-metal dielectric (PMD) oxide layer in 3D NAND. This paper explores the challenges in the application of PE TEOS in 3D NAND PMD oxide layer. In our experiment both PE TEOS and HDP are employed as the PMD oxide for 3D NAND staircase protection. There is not any void found in the two oxide structures. However, oxide pitting is spotted in the subsequent diluted hydrofluoric acid wet etching in the PE TEOS split. Moreover, we observe that the top silicon nitride corrodes in hot phosphoric acid. We study the mechanism of PE TEOS oxide pitting and silicon nitride corroding, propose two solutions: (1) HDP oxide + PE TEOS, and (2) PE TEOS + dry etching. Experimental results demonstrate that our solutions can well address the issue of PE TEOS oxide pitting and effectively protect the staircase structure. This work extends the application of PE TEOS oxide of which the cost and the stress are both low in 3D NAND. [ABSTRACT FROM AUTHOR]

Extensive testing is essential to break the transmission of SARS-CoV-2, which causes the ongoing COVID-19 pandemic. Here, we present a CRISPR-based diagnostic assay that is robust to viral genome mutations and temperature, produces results fast, can be applied directly on nasopharyngeal (NP) specimens without RNA purification, and incorporates a human internal control within the same reaction. Specifically, we show that the use of an engineered AsCas12a enzyme enables detection of wildtype and mutated SARS-CoV-2 and allows us to perform the detection step with loop-mediated isothermal amplification (LAMP) at 60-65 °C. We also find that the use of hybrid DNA-RNA guides increases the rate of reaction, enabling our test to be completed within 30 minutes. Utilizing clinical samples from 72 patients with COVID-19 infection and 57 healthy individuals, we demonstrate that our test exhibits a specificity and positive predictive value of 100% with a sensitivity of 50 and 1000 copies per reaction (or 2 and 40 copies per microliter) for purified RNA samples and unpurified NP specimens respectively. As the COVID-19 pandemic continues, variants of the virus are emerging. Here the authors present a diagnostic assay that can detect wildtype and known variants using engineered Cas12a. [ABSTRACT FROM AUTHOR]

Herein we investigated the morphology, chemical characteristics, and source apportionment of fine particulate matter (PM2.5) samples collected from five sites in Jiaxing. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed that soot aggregates and coal-fired fly ash were generally the most abundant components in the samples. All the samples were analyzed gravimetrically for mass concentrations and their various compositions were determined. Our results revealed that the PM2.5 concentrations in the samples were in the following order: winter > spring > autumn > summer. The PM2.5 concentrations in winter and spring were higher than those in autumn and summer, except for inorganic elements. Carbonaceous species and water-soluble inorganic ions were the most abundant components in the samples, accounting for 26.17–50.44% and 34.27–49.6%, respectively. The high secondary organic carbon/organic carbon ratio indicated that secondary organic pollution in Jiaxing was severe. The average ratios of NO3−/SO42−, ranging from 1.01 to 1.25 at the five sites, indicated that mobile pollution sources contributed more to the formation of PM2.5 than stationary sources. The BeP/(BeP + BaP) ratio (0.52–0.71) in samples reflected the influence of transportation from outside of Jiaxing. The positive matrix factorization (PMF) model identified eight main pollution sources: secondary nitrates (26.95%), secondary sulfates (15.49%), secondary organic aerosol (SOA) (19.64%), vehicle exhaust (15.67%), coal combustion (8.6%), fugitive dust (7.7%), ships and heavy oil (5.23%), biomass burning, and other sources (0.91%). Therefore, PM2.5 pollution in Jiaxing during the winter and spring seasons was more severe than that in the summer and autumn. Secondary aerosols were the most important source of PM2.5 pollution; therefore, focus should be placed on controlling gaseous precursors. [ABSTRACT FROM AUTHOR]

Background: In adult women with polycystic ovary syndrome (PCOS) 17-OHP responses to human chorionic gonadotropin (hCG) stimulation are highly variable and inversely correlated with serum anti-Mullerian hormone (AMH) levels. The objective of this study was to determine whether adolescents with PCOS exhibit similar variable 17-OHP responsiveness to hCG and whether these responses are correlated to AMH levels. Methods: In a prospective study, adolescent PCOS (n=14) and normal controls (n=10) received 25 μg of hCG, intravenously. Blood samples were obtained before and 24 h afterwards for measurement of 17-OHP and basal AMH. Results: Variable 17-OHP responses to hCG were observed among PCOS girls similar to that observed in adults. There was no correlation between AMH and 17-OHP responses to hCG. Conclusions: Among adult and adolescent individuals with PCOS variable 17-OHP production appears to be characteristic of the disorder. In adolescent PCOS, 17-OHP responsiveness to hCG is not correlated to AMH. [ABSTRACT FROM AUTHOR]

Ce/Nd-containing UiO-7 molecular sieves were ionothermally synthesized in imidazole-tetramethylammonium chloride eutectic mixture. The reaction conditions were systematically investigated. It is concluded that the crystallinity of products changes with Ce(Nd)/Al ratios and crystallization temperature. The morphologies and properties of Me-UiO-7 (Me = Ce, Nd) were characterized through X-ray powder diffraction (XRD), scanning electron microscopy (SEM), ultraviolet-visible spectroscopy (UV-Vis), Brunauer-Emmett-Teller (BET) and thermogravimetric analysis (TG). The results indicate that hetero atom Ce and Nd occupy the sites of Al in crystal lattice of molecular sieves by isomorphous replacement and partially entered the framework of UiO-7 molecular sieve. The morphology of Ce-UiO-7 is rectangular columnar with smooth surface, and the morphology of Nd-UiO-7 leaf-like with rough surface. The thermal stability of Ce-UiO-7 and Nd-UiO-7 are both superior to UiO-7. The BET surface areas of Ce-UiO-7 and Nd-UiO-7 are also larger than that of UiO-7. [ABSTRACT FROM AUTHOR]

Here we report the application of solid dispersion (SD) technique to improve paclitaxel (PTX) release from poly(ε-caprolactone) (PCL)-based film. Paclitaxel solid dispersions (SDs) with either poloxamer188 (PXM) or polyethylene glycol (PEG) were successfully prepared by a melting method and then incorporated into PCL films, which were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC) and In vitro drug release/dissolution studies. It was found that PTX was faster released from the SDs than the corresponding physical mixtures (PMs) or PTX alone. For the PCL films with almost the same PTX loading, drug release from films containing SDs was remarkably faster than that from the film directly incorporated with PTX particles, and the films containing SDs with PXM exhibited a faster drug release than those with PEG. An increase In the content of PXM had no significant influence on PTX release from the films containing SDs. Incorporation of a higher content of SDs led to slower drug release from PCL films, indicating that PTX loading had a dominating effect on drug release. Through this study, we demonstrated the feasibility of the application of SD technique on the improvement of PTX release from PCL films and offered some beneficial information on modulating drug release behavior by changing the compositions and contents of the SDs-loaded PCL films. [ABSTRACT FROM AUTHOR]

Hydrophilic 5-fluorouracil (5-FU) loaded cylindrical poly(εϵ-caprolactone) (PCL) implants with different implant diameters (2, 4 and 8 mm), different drug loadings (25% and 50%) and end-capping were fabricated and characterized. The implant structure, drug content and molecular weight of PCL after 120 days drug release were investigated. The in vitro release results showed that, when the drug loading was the same, drug release was fastest for the implant with a diameter of 2 mm and slowest for the implant with a diameter of 8 mm; for the implants with the same diameters, the release of drug from the implants with 50% drug loading was faster than that from the implants with 25% drug loading; however, this effect of drug loading decreased with the increase of implant diameter; in addition, 5-FU was released slightly slower from the end-capped implants than from the corresponding uncapped implants; the drug release data for all the uncapped implants were best fit with the Ritger-Peppas model. Drug release from the hydrophobic implants was found to be dominated by diffusion mechanism. Scanning electron microscopy images and drug content measurements revealed that 5-FU release took place gradually from the exterior region to the interior region of the implants. [ABSTRACT FROM AUTHOR]