Explore the vast range of titles available.

The discovery of ferroelectricity in HfO2-based materials in 2011 provided new research directions and opportunities. In particular, for atomic layer deposited Hf0.5Zr0.5O2 (HZO) films, it is possible to obtain homogenous thin films with satisfactory ferroelectric properties at a low thermal budget process. Based on experiment demonstrations over the past 10 years, it is well known that HZO films show excellent ferroelectricity when sandwiched between TiN top and bottom electrodes. This work reports a comprehensive study on the effect of TiN top and bottom electrodes on the ferroelectric properties of HZO thin films (10 nm). Investigations showed that during HZO crystallization, the TiN bottom electrode promoted ferroelectric phase formation (by oxygen scavenging) and the TiN top electrode inhibited non-ferroelectric phase formation (by stress-induced crystallization). In addition, it was confirmed that the TiN top and bottom electrodes acted as a barrier layer to hydrogen diffusion into the HZO thin film during annealing in a hydrogen-containing atmosphere. These features make the TiN electrodes a useful strategy for improving and preserving the ferroelectric properties of HZO thin films for next-generation memory applications.

Polyphenols have been suggested to aid exercise recovery through antioxidant properties, but their efficacy remains controversial, partly due to limited bioavailability. This study investigated whether low-molecular weight polyphenols (LMWPs, oligonol) influence metabolic responses related to fatigue and oxidative stress during and after a maximal exercise test in healthy young men. A randomized, single-blind crossover design includes a placebo, a single dose of LMWP (S-LMWP), and 5-day LMWP (5-LMWP) intervention with ≥2-week washouts. Ten eligible participants completed all conditions. Exercise performance, fatigue-related metabolic parameters, and oxidative stress markers were measured before, immediately after, and 30 min after exercise. Heart rate and lactate were additionally assessed for 5 min post-exercise. Exercise performance and anthropometrics did not differ among conditions. However, both LMWP groups showed significantly lower blood lactate at 30 min recovery compared with the placebo group (placebo: 17.09 ± 1.29; S-LMWP: 8.36 ± 0.73; 5-LMWP: 9.18 ± 0.60; p = 0.005). Malondialdehyde (MDA), elevated immediately post-exercise, returned closer to baseline at 30 min in the LMWP groups, particularly S-LMWP. Percent MDA change was significantly lower in the S-LMWP group than in the placebo group (placebo: 26.80 ± 3.01; S-LMWP: −8.41 ± 4.86; p = 0.007). Short-term LMWP supplementation did not affect performance or immediate responses but was associated with a more favorable recovery profile, including lower lactate and faster normalization of oxidative stress markers. Larger controlled studies are needed to confirm these findings.

Aluminum nitride (AlN) thin films were grown using thermal atomic layer deposition in the temperature range of 175–350 °C. The thin films were deposited using trimethyl aluminum (TMA) and hydrazine (N2H4) as a metal precursor and nitrogen source, respectively. Highly reactive N2H4, compared to its conventionally used counterpart, ammonia (NH3), provides a higher growth per cycle (GPC), which is approximately 2.3 times higher at a deposition temperature of 300 °C and, also exhibits a low impurity concentration in as-deposited films. Low temperature AlN films deposited at 225 °C with a capping layer had an Al to N composition ratio of 1:1.1, a close to ideal composition ratio, with a low oxygen content (7.5%) while exhibiting a GPC of 0.16 nm/cycle. We suggest that N2H4 as a replacement for NH3 is a good alternative due to its stringent thermal budget.

Atomic layer deposition (ALD) technique has been widely employed in the semiconductor industry. As the devices continuously scaling down to sub 3 nm, SiOx and SiNx thin films, for applications such as a spacer or an etch stopper, are expected to satisfy stringent requirements (e.g., precise thickness control, high bulk film density, high wet-etch resistance, conformality, and lowthermal budget) in the current back-end-of-line process. Besides the film qualities, challenges in the current “top-down” approach also need to be addressed to reduce the size of the devices. Moreover, the lack of a fundamental understanding of surface chemistry using in-situ characterization can further impede future interconnect technology.This dissertation focuses on the application of the ALD process for current and future interconnect technology applications. The first study is ALD of high-quality SiOx and SiNx films with lowtemperature feasibility. With the structural modification of conventional Si precursors (e.g., the addition of ligand or substitution of terminating groups), the molecular polarity of precursors is changed, resulting in the improvement of surface reactivities. By leveraging the unique structure of the Si sources, the film deposition at low temperature with enhanced film properties can be achieved. Secondly, this dissertation further identifies the correlation between the metal surface condition and physical/chemical stability of passivation materials in application to the areaselective deposition process. Using in-situ reflectance absorption infrared spectroscopy (RAIRS), X-ray photoelectron spectroscopy (XPS), and high-resolution TEM analysis, the issues arising with poor ALD selectivity are identified. After analyzing the issues, the potential solution to provide a high-quality SAM monolayer is demonstrated. Lastly, a cleaning process using a noble metal cleaning agent, in which a clean metal surface at low temperature (< 200 o C) can be achieved, is developed. The unique cleaning process could pave the way for the implementation of the consecutive organic-free area-selective-deposition process.

The effects of yarn number and liquid ammonia (L/A) treatment on the physical properties of woven fabrics prepared with pure hemp spun yarns were investigated. As a result of L/A treatment, the crystal structure of hemp fiber was changed from cellulose I to the mixtures of cellulose III and cellulose I and its crystallinity was slightly decreased by 13 %. The crease recovery of hemp fabric treated with L/A was improved upto 78 %. The washing shrinkage of hemp fabric treated with L/A decreased significantly to less than 0.4 %, while the washing shrinkage of hemp fabric prepared with the fined yarn was superior to that of hemp fabric prepared with the coarsed yarn. Especially, the wicking speed and drying ratio of hemp fabrics treated with L/A were higher than those of the untreated as yarn number increased. However, it was found that there is no significant effect on the UV protection of the L/A treated hemp fabrics.

The objective of this study was to evaluate the prognostic value of C-reactive protein (CRP), procalcitonin (PCT), and their combination for mortality in patients with septic shock. This multicenter, prospective, observational study was conducted between November 2015 and December 2017. A total of 1,772 septic shock patients were included, and the overall 28-day mortality was 20.7%. Although both CRP and PCT were elevated in the non-survivor group, only CRP had statistical significance (11.9 mg/dL vs. 14.7 mg/dL, p = 0.003, 6.4 ng/mL vs. 8.2 ng/mL, p = 0.508). Multivariate analysis showed that CRP and PCT were not independent prognostic markers. In the subgroup analysis of the CRP and PCT combination matrix using their optimal cut-off values (CRP 14.0 mg/dL, PCT 17.0 ng/dL), both CRP and PCT elevated showed significantly higher mortality (Odds ratio 1.552 [95% Confidence intervals 1.184–2.035]) than both CRP and PCT not elevated (p = 0.001) and only PCT elevated (p = 0.007). However, both CRP and PCT elevated was also not an independent predictor in multivariate analysis. Initial levels of CRP and PCT alone and their combinations in septic shock patients had a limitation to predict 28-day mortality. Future research is needed to determine new biomarkers for early prognostication in patients with septic shock.

Resistance switching in metal oxides could form the basis for next-generation non-volatile memory. It has been argued that the current in the high-conductivity state of several technologically relevant oxide materials flows through localized filaments, but these filaments have been characterized only indirectly, limiting our understanding of the switching mechanism. Here, we use high-resolution transmission electron microscopy to probe directly the nanofilaments in a Pt/TiO 2 /Pt system during resistive switching. In situ current–voltage and low-temperature (∼130 K) conductivity measurements confirm that switching occurs by the formation and disruption of Ti n O 2 n −1 (or so-called Magnéli phase) filaments. Knowledge of the composition, structure and dimensions of these filaments will provide a foundation for unravelling the full mechanism of resistance switching in oxide thin films, and help guide research into the stability and scalability of such films for applications. Nanoscale filaments with a Magnéli structure are shown to be responsible for resistance switching in thin films of TiO 2 , and the properties of the filaments are directly observed during the switching process.

Microplastic pollution causes a major concern in the marine environment due to their worldwide distribution, persistence, and adverse effects of these pollutants in the marine ecosystem. Despite its global presence, there is still a lack of information on the effect of microplastics on marine organisms at the molecular level. Herein we demonstrated ingestion and egestion of nano- (0.05 μm) and micro-sized (0.5 and 6 μm) polystyrene microbeads in the marine copepod Paracyclopina nana , and examined molecular responses to exposure to microbeads with in vivo endpoints such as growth rate and fecundity. Also, we proposed an adverse outcome pathway for microplastic exposure that covers molecular and individual levels. This study provides the first insight into the mode of action in terms of microplastic-induced oxidative stress and related signaling pathways in P. nana .

Single-atom-catalysts (SACs) afford a fascinating activity with respect to other nanomaterials for hydrogen evolution reaction (HER), yet the simplicity of single-atom center limits its further modification and utilization. Obtaining bimetallic single-atom-dimer (SAD) structures can reform the electronic structure of SACs with added atomic-level synergistic effect, further improving HER kinetics beyond SACs. However, the synthesis and identification of such SAD structure remains conceptually challenging. Herein, systematic first-principle screening reveals that the synergistic interaction at the NiCo-SAD atomic interface can upshift the d-band center, thereby, facilitate rapid water-dissociation and optimal proton adsorption, accelerating alkaline/acidic HER kinetics. Inspired by theoretical predictions, we develop a facile strategy to obtain NiCo-SAD on N-doped carbon (NiCo-SAD-NC) via in-situ trapping of metal ions followed by pyrolysis with precisely controlled N-moieties. X-ray absorption spectroscopy indicates the emergence of Ni-Co coordination at the atomic-level. The obtained NiCo-SAD-NC exhibits exceptional pH-universal HER-activity, demanding only 54.7 and 61 mV overpotentials at −10 mA cm −2 in acidic and alkaline media, respectively. This work provides a facile synthetic strategy for SAD catalysts and sheds light on the fundamentals of structure-activity relationships for future applications. While single, dispersed atoms enable efficient atomic utilization, controllably preparing single-atom dimers remains challenging. Here, authors prepare nickel-cobalt single-atom dimers as high-performance pH-universal H 2 evolution electrocatalysts.

This study aimed to develop and validate deep-learning-based artificial intelligence algorithm for predicting mortality of AHF (DAHF). 12,654 dataset from 2165 patients with AHF in two hospitals were used as train data for DAHF development, and 4759 dataset from 4759 patients with AHF in 10 hospitals enrolled to the Korean AHF registry were used as performance test data. The endpoints were in-hospital, 12-month, and 36-month mortality. We compared the DAHF performance with the Get with the Guidelines-Heart Failure (GWTG-HF) score, Meta-Analysis Global Group in Chronic Heart Failure (MAGGIC) score, and other machine-learning models by using the test data. Area under the receiver operating characteristic curve of the DAHF were 0.880 (95% confidence interval, 0.876-0.884) for predicting in-hospital mortality; these results significantly outperformed those of the GWTG-HF (0.728 [0.720-0.737]) and other machine-learning models. For predicting 12- and 36-month endpoints, DAHF (0.782 and 0.813) significantly outperformed MAGGIC score (0.718 and 0.729). During the 36-month follow-up, the high-risk group, defined by the DAHF, had a significantly higher mortality rate than the low-risk group(p<0.001). DAHF predicted the in-hospital and long-term mortality of patients with AHF more accurately than the existing risk scores and other machine-learning models.