241 research outputs found
High-temperature terahertz optical diode effect without magnetic order in polar FeZnMoO
We present a terahertz spectroscopic study of polar ferrimagnet
FeZnMoO. Our main finding is a giant high-temperature optical diode
effect, or nonreciprocal directional dichroism, where the transmitted light
intensity in one direction is over 100 times lower than intensity transmitted
in the opposite direction. The effect takes place in the paramagnetic phase
with no long-range magnetic order in the crystal, which contrasts sharply with
all existing reports of the terahertz optical diode effect in other
magnetoelectric materials, where the long-range magnetic ordering is a
necessary prerequisite. In \fzmo, the effect occurs resonantly with a strong
magnetic dipole active transition centered at 1.27 THz and assigned as electron
spin resonance between the eigenstates of the single-ion anisotropy
Hamiltonian. We propose that the optical diode effect in paramagnetic
FeZnMoO is driven by signle-ion terms in magnetoelectric free energy
Emergent photons and fractionalized excitations in a quantum spin liquid
A quantum spin liquid (QSL) arises from a highly entangled superposition of
many degenerate classical ground states in a frustrated magnet, and is
characterized by emergent gauge fields and deconfined fractionalized
excitations (spinons). Because such a novel phase of matter is relevant to
high-transition-temperature superconductivity and quantum computation, the
microscopic understanding of QSL states is a long-sought goal in condensed
matter physics. The 3D pyrochlore lattice of corner-sharing tetrahedra can host
a QSL with U(1) gauge fields called quantum spin ice (QSI), which is a quantum
(with effective ) analog of the classical (with large effective moment)
spin ice. A key difference between QSI and classical spin ice is the predicted
presence of the linearly dispersing collective excitations near zero energy,
dubbed the "photons", arising from emergent quantum electrodynamics, in
addition to the spinons at higher energies. Recently, 3D pyrochlore systems
Ce2M2O7 (M = Sn, Zr, Hf) have been suggested as effective QSI
candidates, but there has been no evidence of quasielastic magnetic scattering
signals from photons, a key signature for a QSI. Here, we use polarized neutron
scattering experiments on single crystals of Ce2Zr2O7 to conclusively
demonstrate the presence of magnetic excitations near zero energy at 50 mK in
addition to signatures of spinons at higher energies. By comparing the energy
(E), wave vector (Q), and polarization dependence of the magnetic excitations
with theoretical calculations, we conclude that Ce2Zr2O7 is the first example
of a dipolar-octupolar flux QSI with dominant dipolar Ising interactions,
therefore identifying a microscopic Hamiltonian responsible for a QSL
Imaging antiferromagnetic antiphase domain boundaries using magnetic Bragg diffraction phase contrast
Manipulating magnetic domains is essential for many technological
applications. Recent breakthroughs in Antiferromagnetic Spintronics brought up
novel concepts for electronic device development. Imaging antiferromagnetic
domains is of key importance to this field. Unfortunately, some of the basic
domain types, such as antiphase domains, cannot be imaged by conventional
techniques. Herein, we present a new domain projection imaging technique based
on the localization of domain boundaries by resonant magnetic diffraction of
coherent x rays. Contrast arises from reduction of the scattered intensity at
the domain boundaries due to destructive interference effects. We demonstrate
this approach by imaging antiphase domains in a collinear antiferromagnet
Fe2Mo3O8, and observe evidence of domain wall interaction with a structural
defect. This technique does not involve any numerical algorithms. It is fast,
sensitive, produces large-scale images in a single-exposure measurement, and is
applicable to a variety of magnetic domain types
Causes and effects of 2008 financial crisis
Beginning in the mid 2007’s the US financial market started to slide into the “worst financial crisis since the Great Depression of the early 1930’s” (Thakor, 2015: p.156). The domino effect of several events and occasions were leading first to a countrywide recession in the USA then later spreading globally. In the following this term paper will deal with the main causes and effects of 2008 financial crisis. Unlike other topics in literature there is no consensus about the question of guilt in this sense. Among economists there are different approaches to explain the main causes of the financial crisis
Effectiveness and tolerability of transdermal buprenorphine patches: a multicenter, prospective, open-label study in Asian patients with moderate to severe chronic musculoskeletal pain
AEs: Adverse events; BS-11: Box Scale-11; CIs: Confidence intervals; EAPC: European Association for Palliative Care; EQ VAS: EQ-5D visual analogue scale; EQ-5D-3 L questionnaire: EuroQol Group 5-Dimension SelfReport Questionnaire-3 Level Version Survey; GSQA: Global Sleep Quality Assessment Scale; ITT: Intent-to-treat; LS: Least squares; NICE: National Institute for Health and Care Excellence; NSAIDs: Nonsteroidal antiinflammatory drugs; PP: Per-protocol; SD: Standard deviation; TDB: Transdermal buprenorphine; TEAEs: Treatment-emergent adverse eventsAbstract
Background
We examined the effectiveness and tolerability of transdermal buprenorphine (TDB) treatment in real-world setting in Asian patients with musculoskeletal pain.
Methods
This was an open-label study conducted in Hong Kong, Korea, and the Philippines between June 2013 and April 2015. Eligible patients fulfilled the following criteria: 18 to 80 years of age; clinical diagnosis of osteoarthritis, rheumatoid arthritis, low back pain, or joint/muscle pain; chronic non-malignant pain of moderate to severe intensity (Box-Scale-11 [BS-11] pain score ≥ 4), not adequately controlled with non-opioid analgesics and requiring an opioid for adequate analgesia; and no prior history of opioid treatment. Patients started with a 5 μg/h buprenorphine patch and were titrated as necessary to a maximum of 40 μg/h over a 6-week period to achieve optimal pain control. Patients continued treatment with the titrated dose for 11 weeks. The primary efficacy endpoint was the change in BS-11 pain scores. Other endpoints included patients sleep quality and quality of life as assessed by the 8-item Global Sleep Quality Assessment Scale (GSQA) questionnaire and the EuroQol Group 5-Dimension Self-Report Questionnaire-3 Level version (EQ-5D-3 L), respectively. Tolerability was assessed by collecting adverse events.
Results
A total of 114 eligible patients were included in the analysis. The mean BS-11 score at baseline was 6.2 (SD 1.6). Following initiation of TDB, there was a statistically significant improvement in BS-11 score from baseline to visit 3 (least squares [LS] mean change: -2.27 [95% CI -2.66 to −1.87]), which was maintained till the end of the study (visit 7) (LS mean change: −2.64 [95% -3.05 to −2.23]) (p < 0.0001 for both). The proportion of patients who rated sleep quality as good increased from 14.0% at baseline to 26.9% at visit 6. By visit 6, the mean EQ VAS score increased by 7.7 units (SD 17.9). There were also significant improvements in patients levels of functioning for all EQ-5D-3 L dimensions from baseline at visit 6 (p < 0.05 for all). Seventy-eight percent of patients reported TEAEs and 22.8% of patients discontinued due to TEAEs. TEAEs were generally mild to moderate in intensity (96.5%).
Conclusions
TDB provides effective pain relief with an acceptable tolerability profile over the 11-week treatment period in Asian patients with chronic musculoskeletal pain. More studies are needed to examine the long-term efficacy and safety of TBD treatment in this patient population.This study was funded by Mundipharma Pte Ltd., Singapor
Development of the ASHRAE Global Thermal Comfort Database II
Recognizing the value of open-source research databases in advancing the art and science of HVAC, in 2014 the ASHRAE Global Thermal Comfort Database II project was launched under the leadership of University of California at Berkeley's Center for the Built Environment and The University of Sydney's Indoor Environmental Quality (IEQ) Laboratory. The exercise began with a systematic collection and harmonization of raw data from the last two decades of thermal comfort field studies around the world. The ASHRAE Global Thermal Comfort Database II (Comfort Database), now an online, open-source database, includes approximately 81,846 complete sets of objective indoor climatic observations with accompanying “right-here-right-now” subjective evaluations by the building occupants who were exposed to them. The database is intended to support diverse inquiries about thermal comfort in field settings. A simple web-based interface to the database enables filtering on multiple criteria, including building typology, occupancy type, subjects' demographic variables, subjective thermal comfort states, indoor thermal environmental criteria, calculated comfort indices, environmental control criteria and outdoor meteorological information. Furthermore, a web-based interactive thermal comfort visualization tool has been developed that allows end-users to quickly and interactively explore the data.acceptedVersio
Pooled analysis of who surgical safety checklist use and mortality after emergency laparotomy
Background: The World Health Organization (WHO) Surgical Safety Checklist has fostered safe practice for 10 years, yet its place in emergency surgery has not been assessed on a global scale. The aim of this study was to evaluate reported checklist use in emergency settings and examine the relationship with perioperative mortality in patients who had emergency laparotomy. Methods: In two multinational cohort studies, adults undergoing emergency laparotomy were compared with those having elective gastrointestinal surgery. Relationships between reported checklist use and mortality were determined using multivariable logistic regression and bootstrapped simulation. Results: Of 12 296 patients included from 76 countries, 4843 underwent emergency laparotomy. After adjusting for patient and disease factors, checklist use before emergency laparotomy was more common in countries with a high Human Development Index (HDI) (2455 of 2741, 89⋅6 per cent) compared with that in countries with a middle (753 of 1242, 60⋅6 per cent; odds ratio (OR) 0⋅17, 95 per cent c.i. 0⋅14 to 0⋅21, P < 0⋅001) or low (363 of 860, 42⋅2 percent; OR 0⋅08, 0⋅07 to 0⋅10, P < 0⋅001) HDI. Checklist use was less common in elective surgery than for emergency laparotomy in high-HDI countries (risk difference −9⋅4 (95 per cent c.i. −11⋅9 to −6⋅9) per cent; P < 0⋅001), but the relationship was reversed in low-HDI countries (+12⋅1 (+7⋅0 to +17⋅3) per cent; P < 0⋅001). In multivariable models, checklist use was associated with a lower 30-day perioperative mortality (OR 0⋅60, 0⋅50 to 0⋅73; P < 0⋅001). The greatest absolute benefit was seen for emergency surgery in low-and middle-HDI countries. Conclusion: Checklist use in emergency laparotomy was associated with a significantly lower perioperative mortality rate. Checklist use in low-HDI countries was half that in high-HDI countries
Global economic burden of unmet surgical need for appendicitis
Background: There is a substantial gap in provision of adequate surgical care in many low-and middle-income countries. This study aimed to identify the economic burden of unmet surgical need for the common condition of appendicitis. Methods: Data on the incidence of appendicitis from 170 countries and two different approaches were used to estimate numbers of patients who do not receive surgery: as a fixed proportion of the total unmet surgical need per country (approach 1); and based on country income status (approach 2). Indirect costs with current levels of access and local quality, and those if quality were at the standards of high-income countries, were estimated. A human capital approach was applied, focusing on the economic burden resulting from premature death and absenteeism. Results: Excess mortality was 4185 per 100 000 cases of appendicitis using approach 1 and 3448 per 100 000 using approach 2. The economic burden of continuing current levels of access and local quality was US 73 141 million using approach 2. The economic burden of not providing surgical care to the standards of high-income countries was 75 666 million using approach 2. The largest share of these costs resulted from premature death (97.7 per cent) and lack of access (97.0 per cent) in contrast to lack of quality. Conclusion: For a comparatively non-complex emergency condition such as appendicitis, increasing access to care should be prioritized. Although improving quality of care should not be neglected, increasing provision of care at current standards could reduce societal costs substantially
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