Efficient Emission of Highly Polarized Thermal Radiation from a Suspended Aligned Carbon Nanotube Film.

A polarized light source covering a wide wavelength range is required in applications across diverse fields, including optical communication, photonics, spectroscopy, and imaging. For practical applications, high degrees of polarization and thermal performance are needed to ensure the stability of the radiation intensity and low energy consumption. Here, we achieved efficient emission of highly polarized and broadband thermal radiation from a suspended aligned carbon nanotube film. The anisotropic nature of the film, combined with the suspension, led to a high degree of linear polarization (∼0.9) and great thermal performance. Furthermore, we performed time-resolved measurements of thermal emission from the film, revealing a fast time response of approximately a few microseconds. We also obtained visible light emission from the device and analyzed the film's mechanical breakdown behavior to improve the emission intensity. Finally, we demonstrated that suspended devices with a constriction geometry can enhance the heating performance. These results show that carbon nanotube film-based devices, as electrically driven thermal emitters of polarized radiation, can play an important role for future development in optoelectronics and spectroscopy.

Medication incidents associated with the provision of medication assistance by non-medical care staff in residential care facilities.

The shift towards community-based care in Japan has led to increased medication assistance for older people by non-medical care staff. These staff members help take pre-packaged medications, apply patches, and administer eye drops. This study assessed the risks associated with such assistance by reviewing medication-related incidents across 106 residential care facilities between April 1, 2015, and March 31, 2016. An analysis of incident reports showed that all incidents were minor, with no serious outcomes. The incidents were categorized into four types: dropped drugs, misdelivery/misuse of medicines, forgetting to take medicines, and loss of medicines, with dropped drugs being the most frequent. Most incidents occurred in the morning and primarily involved residents with intermediate nursing care needs. These findings indicate a low risk of serious incidents because of medication assistance from non-medical staff. However, the frequency and nature of the incidents were influenced by the timing of medication administration and the care needs of the residents. These insights highlight the need for customized approaches to medication assistance, considering the residents' care levels and potentially optimizing medication administration times to improve safety in residential care settings.

High-Speed Modulation of Polarized Thermal Radiation from an On-Chip Aligned Carbon Nanotube Film.

Spectroscopic analysis with polarized light has been widely used to investigate molecular structure and material behavior. A broadband polarized light source that can be switched on and off at a high speed is indispensable for reading faint signals, but such a source has not been developed. Here, using aligned carbon nanotube (CNT) films, we have developed broadband thermal emitters of polarized infrared radiation with switching speeds of ≲20 MHz. We found that the switching speed depends on whether the electrical current is parallel or perpendicular to the CNT alignment direction with a significantly higher speed achieved in the parallel case. Together with detailed theoretical simulations, our experimental results demonstrate that the contact thermal conductance to the substrate and the conductance to the electrodes are important factors that determine the switching speed. These emitters can lead to advanced spectroscopic analysis techniques with polarized radiation.

Analysis of contributory factors to incidents related to medication assistance for residents taking medicines in residential care homes for the elderly: a qualitative interview survey with care home staff.

BACKGROUND: In Japan, staff who are not doctors or nurses can assist the elderly in residential care facilities to take their pre-packaged medicines. Therefore, there is a potential risk of incidents specific to staffs. The aim of this study was to clarify the causes of incidents related to medication assistance by staff in residential care facilities. METHOD: Semi-structured interviews with staff involved in medication incidents in long-term care facilities, focusing on how and why each incident happened, were conducted. The interview covered basic information about the subject and resident, the circumstances under which the incident had occurred, contributing factors, and countermeasures put in place. Verbatim transcripts of the interviews were prepared. Based on thematic analysis, codes and themes were created. RESULTS: Twelve subjects participated in this study. All subjects were staffs (not doctors or nurses) in long-term care facilities. All incidents covered in this study were incidents in which the wrong resident was given the medication. The incidents arose because of "not following procedures", such as lack of "self-check of residents' faces/residents' names/residents' medicine envelopes" or "double-check with other staff" or "using a device for medication intake". Contributory factors were grouped into four categories: individual resident factor items such as "decreased ability to understand their medication" or "refusal to take medicines", individual staff factor items such as "lack of knowledge related to medication" or "mental burden" or "experience in medication assistance", team factor items such as "failure to communicate with other staff", work environment factor items such as "presence of other residents" or "other work besides medication assistance" or "not enough time" or "little understanding of fostering a safety culture at the facility". CONCLUSION: This study identified four categories of contributory factors that may lead to incidents during medication assistance by caregivers for residents of care homes. These findings should be helpful for risk management in residential care facilities where staff usually provide medication assistance. Separation of meal times and medication assistance, and professional review to stagger the timing of administration of residents' medication may be effective in reducing incidents.

Microemitter-Based IR Spectroscopy and Imaging with Multilayer Graphene Thermal Emission.

IR analyses such as Fourier transform infrared spectroscopy (FTIR) are widely used in many fields; however, the performance of FTIR is limited by the slow speed (∼10 Hz), large footprint (∼ millimeter), and glass bulb structure of IR light sources. Herein, we present IR spectroscopy and imaging based on multilayer-graphene microemitters, which have distinct features: a planar structure, bright intensity, a small footprint (sub-µm2), and high modulation speed of >50 kHz. We developed an IR analysis system based on the multilayer-graphene microemitter and performed IR absorption spectroscopy. We show two-dimensional IR chemical imaging that visualizes the distribution of the chemical information. In addition, we present high-spatial-resolution IR imaging with a spatial resolution of ∼1 µm, far higher than the diffraction limit. The graphene-based IR spectroscopy and imaging can open new routes for IR applications in chemistry, material science, medicine, biology, electronics, and physics.

High-Speed and On-Chip Optical Switch Based on a Graphene Microheater.

Graphene is a promising material for producing optical devices because of its optical, electronic, thermal, and mechanical properties. Here, we demonstrated on-chip optical switches equipped with a graphene heater, which exhibited high modulation speed and efficiency. We designed the optimal structure of the optical switch with an add/drop-type racetrack resonator and two output waveguides (the through and drop ports) by the electromagnetic field calculation. We fabricated the optical switch in which the graphene microheater was directly placed on the resonator and directly observed its operation utilizing a near-infrared camera. As observed from the transmission spectra, this device exhibited high wavelength tuning efficiency of 0.24 nm/mW and high heating efficiency of 7.66 K·µm3/mW. Further, we measured the real-time high-speed operation at 100 kHz and verified that the graphene-based optical switch achieved high-speed modulation with 10%-90% rise and fall response times, 1.2 and 3.6 µs, respectively, thus confirming that they are significantly faster than typical optical switches that are based on racetrack resonators and metal heaters with response times of ∼100 µs. These graphene-based optical switches on silicon chips with high efficiency and speed are expected to enable high-performance silicon photonics and integrated optoelectronic applications.

Manipulation of phase slips in carbon-nanotube-templated niobium-nitride superconducting nanowires under microwave radiation.

We study the manipulation of thermal/quantum phase slips (tPSs/qPSs) in ultra-thin niobium-nitride superconducting nanowires (scNW) grown on carbon-nanotube templates. These NWs exhibit resistive steps in current-voltage (I-V) characteristics, and the number of phase slip centers (PSCs) in an NW can be tuned by the NW length. Under microwave (MW) radiation, emergence of each single PSC can be precisely controlled by varying the MW power. For thin and short scNW, a dip structure between the qPS-dominated low-temperature region and the tPS-dominated high-temperature region were observed owing to anti-proximity effect by electrodes.

[Survey on the Attitudes and Concerns of Nursing Home Staff Regarding Assistance of Medication Administrations in Japan: A Questionnaire Survey].

Care workers at care facilities play an important role in providing medication-administration assistance, and in medication risk management. Nevertheless, research has not made clear the specific concerns that care workers have at work sites, as well as the extent of their burdens. Thus, we conducted a questionnaire survey from October 1 through October 31, 2014 for staff who provide medication-administration assistance at for-pay elderly person homes about the concrete concerns and burdens with regards to the assistance. A total of 1677 respondents were analyzed: 228 nurses and 1449 care workers. Results showed that the care workers had a variety of problems and issues. These included the fact that, since care workers are not medical profession, they were unable to answer questions that the facility residents asked about their medications; they had concerns regarding their own lack of awareness of the efficacies of medications, and as to whether certain drugs were inappropriate for certain patients with swallowing dysfunctions; they wondered whether drugs in tablet forms had to be crushed before administration. They also encountered pharmacological-related issues, including whether administration times and numbers failed to match the lifestyle patterns of facility residents, and so forth. It is presumed that, with active intervention of pharmacists within facilities, these issues could be resolved. Study results, thus, suggested the need for system creation whereby pharmacists can become deeply involved in medication-administration assistance along with the care workers within facilities.

Medications and fall risk: a case-control study in nursing home residents in Japan.

AIM: Falls are a significant problem for older people, but are few studies of the risk of falling in residents of nursing homes in Japan. We aimed to investigate the risk factors for falls and the association of medication use and falls in nursing home residents in Japan. METHODS: This case-control study reviewed the records of residents of who were ≥ 65 years of age and had fallen in 2012 and an age-, sex-, and facility-matched control group selected from 58 nursing homes in Japan. The odds ratios of potential risk factors and current medications were determined by conditional logistic regression. RESULTS: A total of 1832 residents (916 cases and 916 controls) were included. Falls were significantly associated with an inability to walk without assistance or stand up without assistance, need for toileting assistance, visual impairment, insomnia, and dementia. Current prescription of antithrombotic, nonsteroidal anti-inflammatory, or antiparkinson drugs, muscle relaxants, antiepileptics, antipsychotics, antidepressants, opioids, selective serotonin reuptake inhibitors, and memantine was also associated with increased risk of falling. CONCLUSIONS: Many medications were associated with falls in nursing homes residents in Japan. To prevent these falls, caregivers should provide adequate care, and healthcare professionals should consider switching or dose reduction for these medications.

A light emitter based on practicable and mass-producible polycrystalline graphene patterned directly on silicon substrates from a solid-state carbon source.

We developed a procedure for direct patterning of graphene with arbitrary position, size, and shape on silicon substrates from a solid-state carbon source without dry etching processing. Our light emitting graphene devices perform on a par with those based on high crystallinity graphene obtained via mechanical exfoliation or chemical vapor deposition.

Current-induced magnetization switching using an electrically insulating spin-torque generator.

Current-induced magnetization switching through spin-orbit torques is the fundamental building block of spin-orbitronics, which promises high-performance, low-power memory and logic devices. The spin-orbit torques generally arise from spin-orbit coupling of heavy metals. However, even in a heterostructure where a metallic magnet is sandwiched by two different insulators, a nonzero spin-orbit torque is expected because of the broken inversion symmetry; an electrical insulator can be a source of the spin-orbit torques. We demonstrate current-induced magnetization switching using an insulator. We show that oxygen incorporation into the most widely used spintronic material, Pt, turns the heavy metal into an electrically insulating generator of the spin-orbit torques, which enables the electrical switching of perpendicular magnetization in a ferrimagnet sandwiched by insulating oxides. We also show that the spin-orbit torques generated from the Pt oxide can be controlled electrically through voltage-driven oxygen migration. These findings open a route toward energy-efficient, voltage-programmable spin-orbit devices based on insulating metal oxides.

High-speed and on-chip graphene blackbody emitters for optical communications by remote heat transfer.

High-speed light emitters integrated on silicon chips can enable novel architectures for silicon-based optoelectronics, such as on-chip optical interconnects, and silicon photonics. However, conventional light sources based on compound semiconductors face major challenges for their integration with a silicon-based platform because of their difficulty of direct growth on a silicon substrate. Here we report ultra-high-speed (100-ps response time), highly integrated graphene-based on-silicon-chip blackbody emitters in the near-infrared region including telecommunication wavelength. Their emission responses are strongly affected by the graphene contact with the substrate depending on the number of graphene layers. The ultra-high-speed emission can be understood by remote quantum thermal transport via surface polar phonons of the substrates. We demonstrated real-time optical communications, integrated two-dimensional array emitters, capped emitters operable in air, and the direct coupling of optical fibers to the emitters. These emitters can open new routes to on-Si-chip, small footprint, and high-speed emitters for highly integrated optoelectronics and silicon photonics.

What the Desirable Collaboration between Care Workers in Nursing Homes and Phamacists Should Be: An Approach for Security and Safe Medication for Residents in Nursing Homes.

In our previous research, there was no collaboration between care workers and pharmacists, for the most part. As a result, it was discovered that in some cases, problems concerning medication of nursing home residents had not been resolved. To solve this issue, we brought together care workers and pharmacists for a workshop we conducted. We assigned 12 care workers with at least two years of experience and 12 pharmacists to four mixed groups and guided them in the management of in-home long-term medical care and conducted small group discussions (SGD) using the KJ method. In the pre-survey before the workshop, all 12 care workers replied "yes" to having experienced "concerns over medication" and nine (75%) replied "no" to having experienced "discussions (consultations) with pharmacists regarding the medication of residents". As a result of the SGD, "information sharing among professionals" was revealed as a problem common to all groups. Furthermore, common countermeasures for this issue included communication notes and holding collaborative meetings. In the post-survey after the workshop, 67% of the participants replied that their thoughts concerning countermeasures were "coherent", and everyone replied that their "awareness was increased". In a follow-up survey after the workshop, 82% of the participants replied that they were using some form of what they had learned and discovered in the workshop in their actual work.

An Approach for Safe Medication Assistance in Nursing Homes: A Workshop to Identify Problems of and Plan Measures for Care Workers.

We conducted a workshop that aimed to clarify problems with care workers supporting medication use in nursing homes, to propose measures for solving these problems, and to raise awareness of these problems among care workers. Eighteen care workers from different fee-based elderly nursing homes were enrolled in the workshop, and divided into four groups. The participants in these groups identified the issues based on their experiences regarding medication-related incidents, and discussed related problems and viable measures using the KJ method. The issues identified by each group were "dropping a medication", "wrong resident", "refusal to take medication", and "confusion". To resolve these problems, the participants recommended: "conducting study sessions or testing of manuals and medication knowledge", "strengthening monitoring systems", "enhancing information sharing", etc. The involvement of pharmacists was hardly mentioned, despite the workshop being designed for "medication assistance". A post-workshop questionnaire revealed that 88.9% of the participants acknowledged an increased awareness of safe assistance in the use of medication. A follow-up questionnaire, distributed approximately seven months after the workshop, revealed that 82.4% of participants applied the experience and knowledge they learned at the workshop to their work. The workshop seemed to raise awareness and lead to preventive measures for safe medication assistance. Communication between care workers and other health care professionals, such as pharmacists, is important to designing and implementing safe medical care in nursing homes.

An electrically driven, ultrahigh-speed, on-chip light emitter based on carbon nanotubes.

The integration of high-speed light emitters on silicon chips is an important issue that must be resolved in order to realize on-chip or interchip optical interconnects. Here, we demonstrate the first electrically driven ultrafast carbon nanotube (CNT) light emitter based on blackbody radiation with a response speed (1-10 Gbps) that is more than 10(6) times higher than that of conventional incandescent emitters and is either higher than or comparable to that of light-emitting diodes or laser diodes. This high-speed response is explained by the extremely fast temperature response of the CNT film, which is dominated by the small heat capacity of the CNT film and its high heat dissipation to the substrate. Moreover, we experimentally demonstrate 140 ps width pulsed light generation and real-time optical communication. This CNT-based emitter with the advantages of ultrafast response speeds, a small footprint, and integration on silicon can enable novel architectures for optical interconnects, photonic, and optoelectronic integrated circuits.

Short-wavelength electroluminescence from single-walled carbon nanotubes with high bias voltage.

Short-wavelength electroluminescence (EL) emission is observed from unipolar and ambipolar carbon nanotube field-effect transistors (CNFETs) under high bias voltage. EL measurements were carried out with an unsuspended single-walled carbon nanotube (SWNT) in high vacuum to prevent the oxidation damage induced by current heating. Short-wavelength emission under high bias voltage is obtained because of the Schottky barrier reduction and the electric field increase in a SWNT. The simultaneous measurements of transport and EL spectra revealed the excitation mechanism of impact excitation or electron and hole injection dependent on the conduction type of unipolar or ambipolar characteristics. In addition to the EL emission, blackbody radiation was also observed in a p-type CNFET. Taking into account the device temperature estimated from blackbody radiation, the contribution of impact excitation and thermal effect to the exciton production rate was evaluated.

Direct observation of the deformation and the band gap change from an individual single-walled carbon nanotube under uniaxial strain.

We have fabricated a new device for applying uniaxial strain to an individual suspended SWNT, and the form and the photoluminescence (PL) of an individual suspended SWNT under stretching are investigated. The processes of deformation and break of a SWNT under stretching are directly observed by scanning electron microscopy (SEM). From the PL measurements, the emission energy shifts due to the band gap change are measured under the elastic strain. The behaviors of the emission shifts can be related to the deformation processes observed by SEM. Moreover, the emission intensity reduction due to the elastic strain of a SWNT is also observed just before breaking.