29 research outputs found
Tuning ultrafast electron thermalization pathways in a van der Waals heterostructure
Ultrafast electron thermalization - the process leading to Auger
recombination, carrier multiplication via impact ionization and hot carrier
luminescence - occurs when optically excited electrons in a material undergo
rapid electron-electron scattering to redistribute excess energy and reach
electronic thermal equilibrium. Due to extremely short time and length scales,
the measurement and manipulation of electron thermalization in nanoscale
devices remains challenging even with the most advanced ultrafast laser
techniques. Here, we overcome this challenge by leveraging the atomic thinness
of two-dimensional van der Waals (vdW) materials in order to introduce a highly
tunable electron transfer pathway that directly competes with electron
thermalization. We realize this scheme in a graphene-boron nitride-graphene
(G-BN-G) vdW heterostructure, through which optically excited carriers are
transported from one graphene layer to the other. By applying an interlayer
bias voltage or varying the excitation photon energy, interlayer carrier
transport can be controlled to occur faster or slower than the intralayer
scattering events, thus effectively tuning the electron thermalization pathways
in graphene. Our findings, which demonstrate a novel means to probe and
directly modulate electron energy transport in nanoscale materials, represent
an important step toward designing and implementing novel optoelectronic and
energy-harvesting devices with tailored microscopic properties.Comment: Accepted to Nature Physic
Gender differences in personality patterns and smoking status after a smoking cessation treatment
The importance of bracteoles in ensuring Atriplex halimus germination under optimal conditions
Atriplex halimus L. is a native halo-nitrophilous scrub that grows in salt-marsh environments and saline soils of the Mediterranean basin.
The presence of bracteoles did not change the germination rate of seeds and fruits (seeds with bracteoles) in water, although bracteoles did slow down the process, from 2.5 to 5.7 days to reach the 50% of the final germination in seeds and fruits, respectively.
Bracteoles prevented germination NaCl solutions greater than 0.3M. The seeds without bracteoles germinated at concentrations higher than 0.3M NaCl, but had smaller cotyledons than seeds germinated in water (3.1 and 5.6 mm, respectively), and all the roots had necrotic zones. The results showed that bracteoles play an important role in preventing seeds from germinating in NaCl concentrations higher than 0.3M, ensuring that they remained dormant and only germinated when freshwater was available. The recovery experiments showed that the seeds from the fruits that did not germinate in salt were not unviable, but remained dormant, awaiting the proper conditions to germinate. In the presence of water, the final germination was higher than 95%, and there was little necrosis found in the roots. The results showed how the presence of bracteoles prevented germination under unfavourable conditions for plant development
Processes and Outcomes of the Veterans Health Administration Safe Patient Handling Program: Study Protocol
Female dental students’ perceptions of patient safety culture: a cross sectional study at a middle eastern setting
Measuring safety culture in Dutch primary care: psychometric characteristics of the SCOPE-PC questionnaire
G protein-coupled and ATP-sensitive inwardly rectifying potassium ion channels are essential for HIV entry
An Artificial Bee Colony Algorithm Based on Dynamic Penalty and Lévy Flight for Constrained Optimization Problems
Development of an integrative cessation program for co-smokers of cigarettes and cannabis
BACKGROUND: Tobacco and cannabis use are strongly interrelated, but current national and international cessation programs typically focus on one substance, and address the other substance either only marginally or not at all. This study aimed to identify the demand for, and describe the development and content of, the first integrative group cessation program for co-smokers of cigarettes and cannabis. METHODS: First, a preliminary study using expert interviews, user focus groups with (ex-)smokers, and an online survey was conducted to investigate the demand for, and potential content of, an integrative smoking cessation program (ISCP) for tobacco and cannabis co-smokers. This study revealed that both experts and co-smokers considered an ISCP to be useful but expected only modest levels of readiness for participation.Based on the findings of the preliminary study, an interdisciplinary expert team developed a course concept and a recruitment strategy. The developed group cessation program is based on current treatment techniques (such as motivational interviewing, cognitive behavioural therapy, and self-control training) and structured into six course sessions.The program was evaluated regarding its acceptability among participants and course instructors. RESULTS: Both the participants and course instructors evaluated the course positively. Participants and instructors especially appreciated the group discussions and the modules that were aimed at developing personal strategies that could be applied during simultaneous cessation of tobacco and cannabis, such as dealing with craving, withdrawal, and high-risk situations. CONCLUSIONS: There is a clear demand for a double cessation program for co-users of cigarettes and cannabis, and the first group cessation program tailored for these users has been developed and evaluated for acceptability. In the near future, the feasibility of the program will be evaluated