In this work, we have doped carbon into Cr:AlN and got two main results. First, we have found that doping small fraction of carbon will enhance magnetism significantly. This may be useful for ...designing new diluted magnetic semiconductors (DMS) materials and devices. Second, carbon doping modulated electric resistivity significantly. This attracts our further interest in the recent background of resistive memory device.
Carbon was doped into Cr:AlN films. Microstructure analysis demonstrated that the Cr atom kept at AlN lattice when carbon content was lower. The doped carbon atoms formed graphite phases and C–N clusters dispersing in the films, which influenced the electric and magnetic properties significantly. When the resistivity was around 10
5–10
7
Ω
cm under an alternating current (AC) frequency of 210
Hz, it increased with increasing carbon content, and when the resistivity was around 10
3
Ω
cm under a higher AC frequency of 800
kHz, it decreased with increasing carbon content. The magnetisms for the carbon-doped samples are stronger than those of samples without carbon doping. The atomic magnetic moment (AMM) of the sample with a carbon content of 2.3
at.% was the highest (0.4
μ
B/Cr). It was proposed that atomic migration of carbon might have occurred under high AC frequency. The formation of C–N compounds could consume part of the available nitrogen and then increased the density of N vacancy in the Cr:AlN lattice, which is favorable for coupling among bound magnetic polarons (BMP).
To determine the distribution and antimicrobial drug resistance in bacterial pathogens causing nosocomial infections, surveillance data on nosocomial infections documented from 1981 to 1999 at ...National Taiwan University Hospital were analyzed. During this period, 35,580 bacterial pathogens causing nosocomial infections were identified. Candida species increased considerably, ranking first by 1999 in the incidence of pathogens causing all nosocomial infections, followed by Staphylococcus aureus and Pseudomonas aeruginosa. Candida species also increased in importance as bloodstream infection isolates, from 1.0% in 1981-1986 to 16.2% in 1999. The most frequent isolates from urinary tract infections were Candida species (23.6%), followed by Escherichia coli (18.6%) and P. aeruginosa (11.0%). P. aeruginosa remained the most frequent isolates for respiratory tract and surgical site infections in the past 13 years. A remarkable increase in incidence was found in methicillin-resistant S. aureus (from 4.3% in 1981-1986 to 58.9% in 1993-1998), cefotaxime-resistant E. coli (from 0% in 1981-1986 to 6.1% in 1993-1998), and cefotaxime-resistant Klebsiella pneumoniae (from 4.0% in 1981-1986 to 25.8% in 1993-1998). Etiologic shifts in nosocomial infections and an upsurge of antimicrobial resistance among these pathogens, particularly those isolated from intensive care units, are impressive and alarming.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In this work, a lightweight, ultrathin and flexible paper-based gel electrolyte is developed for liquid-free Al-air batteries, which employs a natural cellulose paper to store an alkaline gel. The ...as-fabricated electrolyte can be applied in either mechanical-rechargeable or single-use Al-air batteries, providing an open-circuit voltage (OCV) of 1.5 V and a peak power density around 3.5 mW cm−2. In addition, the battery discharge specific capacity is as high as 900 mA h g−1 even with low-purity Al. Moreover, a flexible Al-air battery can be obtained, which exhibits a stable performance under different bending angles. By optimizing the electrolyte properties including polymer concentration, gel loading and solution casting time, the battery power output can be further improved to 6.4 mW cm−2. Finally, two stacking strategies are investigated for developing Al-air battery packs, including both vertical stacking and planar stacking. Benefited from the complete ionic isolation among the single cells, both stacking strategies are demonstrated viable, with a normal OCV of 5.6 V for a 4-cell stack and a stacking efficiency as high as 87.5%. Such kind of liquid-free Al-air batteries are especially suitable for powering portable electronic devices with small rated power.
•A paper-based gel electrolyte is developed for liquid-free Al-air battery.•The battery can provide an OCV of 1.5 V and a peak power density of 6.4 mW cm−2•A high specific capacity of 900 mA h g−1 can be achieved even with low-purity Al.•A flexible Al-air battery is also successfully developed.•A convenient and efficient stacking of Al-air battery pack is demonstrated.
Psychosocial working conditions have been linked to mental health outcomes, but their association with well-being is poorly studied. We aimed to investigate the association between psychosocial ...working conditions and well-being before retirement, and to explore the role of gender and leisure activities in the association. From the Swedish National Study on Aging and Care in Kungsholmen, 598 community dwellers aged 60-65 years were included in the cross-sectional study. Lifelong occupational history was obtained through an interview. Job demands and job control in the longest-held occupation were graded with job exposure matrices. Psychosocial working conditions were classified into high strain (high demands, low control), low strain (low demands, high control), passive job (low demands, low control), and active job (high demands, high control). Well-being was assessed with the 10-item version of positive and negative affect schedule, and scored using confirmatory factor analysis. Engagement in leisure activities was categorized as low, moderate, and high. Data were analyzed using linear regression. Both high job control and high job demands were dose-dependently associated with higher well-being. Overall, compared to active jobs, passive jobs were associated with lower well-being (β −0.19, 95% CI −0.35 to −0.02, P = 0.028). Passive (β −0.28, 95% CI −0.51 to −0.04, P = 0.020) and high strain (β −0.31, 95% CI −0.52 to −0.10, P = 0.004) jobs were associated with lower well-being in men, but not in women. The association between passive jobs and well-being was attenuated by high leisure activities, while the association between high strain and well-being was magnified by low leisure activities. In conclusion, negative psychosocial working conditions are associated with poor well-being, especially in men. Leisure activities may modulate the association. Our study highlights that promoting favorable working conditions can be a target to improve well-being among employees and active participation in leisure activities is encouraged to cope with work-related stress for better well-being.
With the aim to get a clear understanding of this category of polymerizations, the Michael addition polymerizations of trifunctional amines, i.e. 4-aminomethyl piperidine (AMPD),
N-methyl ...ethylenediamine (MEDA), and 1-(2-aminoethyl) piperazine (AEPZ), with an equimolar diacrylamide,
N,
N′-methylene diacrylamide (MDA), were investigated. Similar to the polymerizations of these amines with an equimolar diacrylate, novel linear poly(amido amine)s containing secondary and tertiary amines in the backbones are obtained from these polymerizations as reflected by
13C NMR (INVGATE). In situ monitoring the polymerization processes using NMR shows that the reactivity sequence of three types amines in the trifunctional amines is 2° amine (original)>1° amine≫2° amine (formed), and the 2° amine (formed) is kept out of the reaction. But these results are different from those reported for the polymerizations of the similar amines with an equimolar divinyl sulfone and some diacrylates. The molecular weights and properties of poly(amindo amine)s obtained were characterized by GPC, DSC and TGA, respectively.
Several studies have demonstrated that exercise helps reduce or prevent cognitive deterioration among older adults, and recent studies have further examined the effects of resistance-exercise ...training on cognition. The purpose of this review was to examine the role of resistance-exercise training on cognition in healthy older adults. Specifically, it describes the definition, health benefits, and the design of resistance-exercise training. The authors also review the research related to resistance exercises and cognition and found that this exercise modality may enhance specific cognitive performances. Next, they examine the potential mechanisms underlying resistance exercise and cognitive enhancement. Finally, they consider potential therapeutics and recommendations for further research on resistance-exercise training and cognition in older adults.
Numerous genetic changes are associated with cancer cell metastasis and invasion. In search for key regulators of invasion and metastasis, a panel of lung cancer cell lines with different invasive ...ability was screened. The gene for contactin-1 was found to play an essential role in tumor invasion and metastasis. Suppression of contactin-1 expression abolished the ability of lung adenocarcinoma cells to invade Matrigel in vitro as well as the polymerization of filamentous-actin and the formation of focal adhesion structures. Furthermore, knockdown of contactin-1 resulted in extensive inhibition of tumor metastasis and in increased survival in an animal model. RhoA but not Cdc42 or Rac1 was found to serve a critical role in contactin-1-mediated invasion and metastasis. Contactin-1-specific RNA interference resulted in loss of metastatic and invasive capacity in both in vitro and in vivo models. This loss was overturned by constitutive expression of the active form of RhoA. Contactin-1 was differentially expressed in tumor tissues, and its expression correlated with tumor stage, lymph node metastasis, and patient survival. Contactin-1 is proposed to function importantly in the invasion and metastasis of lung adenocarcinoma cells via RhoA-mediated mechanisms.
The main purpose of this research is to develop technically, economically, and environmentally attractive construction materials from sediments dredged from Brazilian seaports. The final composite ...material contains 50 to 60 wt% in mass of sediments and thus creates an opportunity to diminish the pollution of the Atlantic Ocean. Construction and demolition debris (20–35%) and lime production wastes (15–30%) were used as components of the composite materials. Uniaxial compressive strength values reach 6.3 MPa on the 3rd day and 14.5 MPa on the 90th day; linear shrinkage varied between 0.07% and 0.35%, water absorption - between 11.0 and 13.4%. These values attend the demands of Brazilian norms on conventional bricks, blocks, etc. XRD, XRF, SEM, EDS, AAS and LAMMA analysis showed that amorphous new formations are responsible for material strengthening.
•Stopping of world oceans environment clogging by contaminated ports dredged sludge.•Construction materials containing 50–60% sludge of sea ports were developed.•Uniaxial compressive strength of the materials on the 90th day of curing reached 14.5 MPa.•The value of linear expansion is 0.35% and water absorption is 13.4% after 90 days.•The materials have new structural formations from mainly amorphous CSH-type and carbonates.
Paper-based microfluidic fuel cells are prominent in flexible electronics, including wearable and disposable devices, such as smart packages and point-of-care diagnostics. However, the performance is ...generally low, and the long-term durability is questionable. In this work, we propose a flexible paper-based fuel cell with a novel cell architecture that adopts a single flow for the delivery of both the fuel and the supporting electrolyte. During cell operation, the anode is immersed in a liquid fuel with a supporting electrolyte, while the cathode is exposed to the ambient air. The performance of this cell is increased by one order of magnitude compared to the conventional co-flow cell architecture due to the enhanced mass transfer. A maximum power density of ~20 mW/cm2 and a maximum current density of 122.9 mA/cm2 are achieved, which are the highest among all reported paper-based direct formate fuel cells. Furthermore, this cell can steadily discharge at 5 mA cm−2 for more than 10 days continuously, while the morphology of the anode and the cathode before and after cell operation remains unchanged. Finally, this paper-based fuel cell can be efficiently fabricated by 3D printing, which is simple, low cost, and advantageous for paper-based fuel cell fabrication.
•An innovative architecture for a single-flow paper-based fuel cell (PBFC) is proposed.•The air-breathing PBFC uses formate as fuel, which can be efficiently fabricated by printing.•A peak power density of 20 mW/cm2 and a cut-off current density of 123 mA/cm2 are achieved.•The PBFC can discharge at 5 mA cm−2 for more than 10 days continuously until fuel depletion.•The PBFC can be re-activated by refueling.
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