1,388 research outputs found
Collapse transition of a square-lattice polymer with next nearest-neighbor interaction
We study the collapse transition of a polymer on a square lattice with both
nearest-neighbor and next nearest-neighbor interactions, by calculating the
exact partition function zeros up to chain length 36. The transition behavior
is much more pronounced than that of the model with nearest-neighbor
interactions only. The crossover exponent and the transition temperature are
estimated from the scaling behavior of the first zeros with increasing chain
length. The results suggest that the model is of the same universality class as
the usual theta point described by the model with only nearest-neighbor
interaction.Comment: 14 pages, 5 figure
Effects of emotional labor on musculoskeletal disorders among physical therapists in Seoul
Introduction: Health care workers, including physical therapists, have some of the most important roles in the health care system as shown during the COVID-19 pandemic. Physical therapists encounter emotionally and physically vulnerable patients, experience emotional labor, and are exposed to conditions that can lead to job stress and musculoskeletal disorders. We aimed to examine the relationship between physical therapistsā emotional labor and its effect on perceived job stress and risk of musculoskeletal disorders.
Methods: We conducted a 30-day survey among 230 physical therapists working in various settings from October 2 to November 1, 2019. Questionnaires, including questions on musculoskeletal symptoms, perceived job stress, and emotional labor, were administered to the participants.
Results: The physical therapist's surface behavior affected the body burden. Job burnout experienced by physical therapists had an effect on their interpersonal relationships. The physical therapist's emotional law affects the degree of compensation.
Conclusion: To prevent the long-term consequences of work-related strain, physical therapists should receive support in terms of maintaining a healthy lifestyle and developing effective methods of communication with patients. Encouragement of activities for psychological rejuvenation with colleagues with whom they can share emotional difficulties is also desirable. It is also necessary to establish a communication channel that can directly convey the grievances of physical therapists to hospitals
Epidemiology of Foodborne Norovirus Outbreak in Incheon, Korea
On June 14, 2008, an outbreak of gastroenteritis occurred among elementary school students in Incheon. We conducted an investigation to identify the source and described the extent of the outbreak. We performed a retrospective cohort study among students, teachers and food handlers exposed to canteen food in the elementary school. Using self-administered questionnaires we collected information on symptoms, days of canteen food eaten, food items consumed. Stool samples were collected from 131 symptomatic people and 11 food handlers. The catering kitchen was inspected and food samples were taken. Of the 1,560 people who ate canteen food, 117 were symptomatic cases, and the attack rate was 7.5%. Consumption of cucumber-crown daisy salad (RR=2.71), fresh cabbage mix (RR=2.23), dried radish salad (RR=3.04) and young radish kimchi (RR=2.52) were associated with illness. Sixty-four (45%) of the 142 stool specimens were positive for Norovirus. Norovirus was detected in 2 food handlers. Interviews with kitchen staff indicated the likelihood of contamination from an infected food handler to the dried radish salad during food processing. The excretion of Norovirus from asymptomatic food handlers may be an infection source of Norovirus outbreaks
Charge Transfer Induced Molecular Hole Doping into Thin Film of Metal-Organic-Frameworks
Despite the highly porous nature with significantly large surface area, metal
organic frameworks (MOFs) can be hardly used in electronic, and optoelectronic
devices due to their extremely poor electrical conductivity. Therefore, the
study of MOF thin films that require electron transport or conductivity in
combination with the everlasting porosity is highly desirable. In the present
work, thin films of Co3(NDC)3DMF4 MOFs with improved electronic conductivity
are synthesized using layer-by-layer and doctor blade coating techniques
followed by iodine doping. The as-prepared and doped films are characterized
using FE-SEM, EDX, UV/Visible spectroscopy, XPS, current-voltage measurement,
photoluminescence spectroscopy, cyclic voltammetry, and incident photon to
current efficiency measurements. In addition, the electronic and semiconductor
property of the MOF films are characterized using Hall Effect measurement,
which reveals that in contrast to the insulator behavior of the as-prepared
MOFs, the iodine doped MOFs behave as a p-type semiconductor. This is caused by
charge transfer induced hole doping into the frameworks. The observed charge
transfer induced hole doping phenomenon is also confirmed by calculating the
densities of states of the as-prepared and iodine doped MOFs based on density
functional theory. Photoluminescence spectroscopy demonstrate an efficient
interfacial charge transfer between TiO2 and iodine doped MOFs, which can be
applied to harvest solar radiations.Comment: Main paper (19 pages, 6 figures) and supplementary information (15
pages, 10 figures), accepted in ACS Appl. Materials & Interface
Exact Partition Function Zeros of a Polymer on a Simple-Cubic Lattice
We study conformational transitions of a polymer on a simple-cubic lattice by
calculating the zeros of the exact partition function, up to chain length 24.
In the complex temperature plane, two loci of the partition function zeros are
found for longer chains, suggesting the existence of both the coil-globule
collapse transition and the melting-freezing transition. The locus
corresponding to coil-globule transition clearly approaches the real axis as
the chain length increases, and the transition temperature could be estimated
by finite-size scaling. The form of the logarithmic correction to the scaling
of the partition function zeros could also be obtained. The other locus does
not show clear scaling behavior, but a supplementary analysis of the specific
heat reveals a first-order-like pseudo-transition.Comment: 21 pages, 4 figure
Influenza Viral Infection Is a Risk Factor for Severe Illness in COVID-19 Patients: A Nationwide Population-Based Cohort Study
In order to prepare for the twindemic of influenza and SARS-CoV-2 infection, we investigated the association between influenza infection and subsequent severity of SARS-CoV-2 infection. A population-based nationwide cohort study was performed using data from the National Health Insurance Service (NHIS) in the Republic of Korea. This study included 274,126 individuals who underwent SARS-CoV-2 PCR testing between 20 January 2020 and 1 October 2020. Among these patients, 28,338 tested positive for SARS-CoV-2, and 4,003 of these individuals had a history of influenza. The control group was selected through 1:1 propensity score matching. In the group of 4,003 COVID-19-positive individuals with no history of influenza, 192 (4.8%) experienced severe illness from COVID-19 infection. In the group of 4,003 COVID-19-positive individuals with a history of influenza, 260 (6.5%) had severe illness from COVID-19, and the overall adjusted odds ratio (aOR) was 1.29 (95% confidence interval 1.04-1.59). Among the 4,003 COVID-19-positive individuals with a history of influenza, severe COVID-19 infection was experienced by 143 of 1,760 (8.1%) with an influenza history within 1 year before the onset of COVID-19, 48 of 1,129 (4.3%) between 1 and 2 years, and 69 of 1,114 (6.2%) between 2 and 3 years before COVID-19 onset, and the aORs were 1.54 (1.20-1.98), 1.19 (0.84-1.70), and 1.00 (0.73-1.37), respectively. In conclusion, individuals who had an influenza infection less than 1 year before COVID-19 infection were at an increased risk of experiencing severe illness from the SARS-CoV-2 infection. To control the public health burden, it is essential that effective public health control measures, which include influenza vaccination, hand washing, cough etiquette, and mask use are in place
Suppression of magnetic ordering in XXZ-type antiferromagnetic monolayer NiPS3
How a certain ground state of complex physical systems emerges, especially in
two-dimensional materials, is a fundamental question in condensed-matter
physics. A particularly interesting case is systems belonging to the class of
XY Hamiltonian where the magnetic order parameter of conventional nature is
unstable in two-dimensional materials leading to a
Berezinskii-Kosterlitz-Thouless transition. Here, we report how the XXZ-type
antiferromagnetic order of a magnetic van der Waals material, NiPS3, behaves
upon reducing the thickness and ultimately becomes unstable in the monolayer
limit. Our experimental data are consistent with the findings based on
renormalization group theory that at low temperatures a two-dimensional XXZ
system behaves like a two-dimensional XY one, which cannot have a long-range
order at finite temperatures. This work provides experimental examination of
the XY magnetism in the atomically thin limit and opens new opportunities of
exploiting these fundamental theorems of magnetism using magnetic van der Waals
materials.Comment: 57 pages, 24 figures (including Supplementary Information
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