The present paper considers the mechanical and fracture properties of four different epoxy polymers containing 0, 10 and 20
wt.% of well-dispersed silica nanoparticles. Firstly, it was found that, ...for any given epoxy polymer, their Young’s modulus steadily increased as the volume fraction,
v
f, of the silica nanoparticles was increased. Modelling studies showed that the measured moduli of the different silica-nanoparticle filled epoxy polymers lay between upper-bound values set by the Halpin–Tsai and the Nielsen ‘no-slip’ models, and lower-bound values set by the Nielsen ‘slip’ model; with the last model being the more accurate at relatively high values of
v
f. Secondly, the presence of silica nanoparticles always led to an increase in the toughness of the epoxy polymer. However, to what extent a given epoxy polymer could be so toughened was related to structure/property relationships which were governed by (a) the values of glass transition temperature,
T
g, and molecular weight,
M
c, between cross-links of the epoxy polymer, and (b) the adhesion acting at the silica nanoparticle/epoxy-polymer interface. Thirdly, the two toughening mechanisms which were operative in all the epoxy polymers containing silica nanoparticles were identified to be (a) localised shear bands initiated by the stress concentrations around the periphery of the silica nanoparticles, and (b) debonding of the silica nanoparticles followed by subsequent plastic void growth of the epoxy polymer. Finally, the toughening mechanisms have been quantitatively modelled and there was good agreement between the experimentally-measured values and the predicted values of the fracture energy,
G
c, for all the epoxy polymers modified by the presence of silica nanoparticles. The modelling studies have emphasised the important roles of the stress versus strain behaviour of the epoxy polymer and the silica nanoparticle/epoxy-polymer interfacial adhesion in influencing the extent of the two toughening mechanisms, and hence the overall fracture energy,
G
c, of the nanoparticle-filled polymers.
Display omitted
Context.
Snowlines during star and disk formation are responsible for a range of effects during the evolution of protostars, such as setting the chemical composition of the envelope and disk. This in ...turn influences the formation of planets by changing the elemental compositions of solids and affecting the collisional properties and outcomes of dust grains. Snowlines can also reveal echoes of past accretion bursts, providing insight into the formation process of stars.
Aims.
The objective is to identify which parameters (e.g., luminosity, gas density, and presence of disk) dictate the location of snowlines during the early, deeply embedded phase and to quantify how each parameter changes the observed snowline location.
Methods.
A numerical chemical network coupled with a grid of cylindrical-symmetric physical models was used to identify what physical parameters alter the CO and H
2
O snowline locations. The investigated parameters are the initial molecular abundances, binding energies of CO and H
2
O, heating source, cloud core density, outflow cavity opening angle, and disk geometry. Simulated molecular line emission maps were used to quantify the change in the snowline location with each parameter.
Results.
The snowline radius of molecules with low sublimation temperatures (≲30 K), such as CO, shift outward on the order of 10
3
AU with an order of magnitude increase in protostellar luminosity. An order of magnitude decrease in cloud core density also shifts the CO snowline position outward by a few 10
3
AU. The presence of disk(-like) structures cause inward shifts by a factor of a few, and mainly along the disk mid-plane. For molecules that sublimate at higher temperatures, such as H
2
O, increasing the protostellar luminosity or decreasing the cloud core density by an order of magnitude shifts the snowline position outward by a factor of a few. The presence of a disk concentrates molecules with high sublimation temperatures to compact regions (a few 10 AU) around the protostar by limiting the outward shift of snowline positions. Successful observational measurements of snowline locations are strongly dependent on spatial resolution, the presence or lack thereof of disk(-like) structures, and the inclination of the disk(-like) structure.
Conclusions.
The CO and H
2
O snowline locations do not occur at a single, well-defined temperature as is commonly assumed. Instead, the snowline position depends on luminosity, cloud core density, and whether a disk is present or not. Inclination and spatial resolution affect the observability and successful measurement of snowline locations. We note that N
2
H
+
and HCO
+
emission serve as good observational tracers of CO and H
2
O snowline locations. However, constraints on whether or not a disk is present, the observation of additional molecular tracers, and estimating envelope density will help in accurately determining the cause of the observed snowline position. Plots of the N
2
H
+
and HCO
+
peak emission radius versus luminosity are provided to compare the models with observations of deeply embedded protostars aiming to measure the CO and H
2
O snowline locations.
Background:
Synthetic cathinone abuse is a global health issue. Synthetic cathinones emerged in Taiwan in 2009, and their prevalence rapidly rose. They are usually made into “instant coffee packets,” ...and these so-called “toxic coffee packets” may also contain psychoactive drugs other than synthetic cathinones. Due to the diversity of the ingredients, clinical presentations can be complex.
Methods:
Retrospective analysis of emergency department (ED) patients who reported ingesting toxic coffee packets at three Chang-Gung Memorial Hospitals located in northern Taiwan between January, 2015 and December, 2019.
Results:
Sixty patients were included. Their mean age was 28.85 ± 9.24 years and 47(78.33%) were male. The most common presentations were palpitation, agitation, hallucination, and altered consciousness. Tachycardia and hypertension were common, while hyperthermia was observed in only three patients. Three patients (5%) developed rhabdomyolysis, and one underwent transient hemodialysis. Most patients were discharged from the ED, but 15(25%) were admitted, of whom nine (15%) were admitted to the intensive care unit (ICU), and one eventually died. Confirmation tests (mass-spectrometry-based analysis) were available in 10 patients; all reported positive for at least one type of synthetic cathinone. Polysubstance exposure was common. In multivariate logistic regression analyses, Glasgow coma scale ≤13 and the presence of seizure were associated with ICU admission.
Conclusion:
Patients who report ingesting toxic coffee packets are very likely to have been exposed to synthetic cathinones. Polysubstance exposure is common following ingestion. Cardiovascular and neurological symptoms are the main presentations, and severe complications such as rhabdomyolysis and life-threatening dysrhythmia can occur.
Finite-temperature phases of many-body quantum systems are fundamental to phenomena ranging from condensed-matter physics to cosmology, yet they are generally difficult to simulate. Using an ion trap ...quantum computer and protocols motivated by the quantum approximate optimization algorithm (QAOA), we generate nontrivial thermal quantum states of the transversefield Ising model (TFIM) by preparing thermofield double states at a variety of temperatures. We also prepare the critical state of the TFIM at zero temperature using quantum–classical hybrid optimization. The entanglement structure of thermofield double and critical states plays a key role in the study of black holes, and our work simulates such nontrivial structures on a quantum computer. Moreover, we find that the variational quantum circuits exhibit noise thresholds above which the lowest-depth QAOA circuits provide the best results.
Summary
What is known and objective
Rhabdomyolysis is a severe potential adverse drug reaction of statin therapy. We report a case of rhabdomyolysis due to drug–drug interaction (DDI) between ...atorvastatin and fluconazole and review the literature.
Case summary
A 70‐year‐old woman received atorvastatin for hyperlipidaemia without any problem for 4 years. When intravenous fluconazole was added for treating a fungal infection, rhabdomyolysis developed 2 weeks later. Removal of atorvastatin led to the resolution of her rhabdomyolysis.
What is new and conclusion
Our case demonstrates that in some subjects even a moderate CYP3A4 inhibitor such as fluconazole may lead to rhabdomyolysis in subjects receiving a statin.
Characteristics of reported cases of rhabdomyolysis associated with drug interaction between statins and fluconazole.
The bilayer-based Antiferroelectric Tunneling Junction (AFTJ) with ferroelectric (FE) HfZrO 2 (HZO) and dielectric (DE) Al 2 O 3 demonstrates a current ratio of <inline-formula> <tex-math ...notation="LaTeX">> 100\times </tex-math></inline-formula>, a TER (tunneling electroresistance) of <inline-formula> <tex-math notation="LaTeX">> 50\times </tex-math></inline-formula>, multilevel states, <inline-formula> <tex-math notation="LaTeX">> 10^{4} </tex-math></inline-formula> sec retention, and a cycling endurance as high as 10 8 . The concept of tunneling current through DE in an antiferroelectric (AFE) system enhances the capacity to modulate the current/TER ratio and makes the AFTJ feasible for low-power crossbar eNVM (embedded nonvolatile memory) applications.
Summary
Background
Data are limited regarding the effectiveness and safety of generic velpatasvir plus sofosbuvir (VEL/SOF) for hepatitis C virus (HCV) in patients with or without human ...immunodeficiency virus (HIV) coinfection.
Aim
To evaluate the effectiveness and safety of generic VEL/SOF‐based therapy for HCV infection in patients with or without HIV coinfection in Taiwan.
Methods
Sixty‐nine HIV/HCV‐coinfected and 159 HCV‐monoinfected patients receiving 12 weeks of generic VEL/SOF with or without ribavirin (RBV) for HCV were prospectively enrolled. The anti‐viral responses and the adverse events (AEs) were compared between the two groups. The characteristics potentially related to sustained virological response 12 weeks off therapy (SVR12) were analysed.
Results
The SVR12 was achieved in 67 HIV/HCV‐coinfected patients (97.1%; 95% CI: 90.0%‐99.2%) and in 156 HCV‐monoinfected patients (98.1%; 95% CI: 94.6%‐99.4%) receiving VEL/SOF‐based therapy, respectively. The SVR12 rates were comparable between HIV/HCV‐coinfected and HCV‐monoinfected patients, regardless of pre‐specified baseline characteristics. One hundred twenty‐two (53.5%) and seven (3.1%) patients had baseline resistance‐associated substitutions (RASs) in HCV NS5A and NS5B regions, but the SVR12 rates were not affected by the presence or absence of RASs. One (1.4%) and five (3.1%) patients in the HIV/HCV‐coinfected and HCV‐monoinfected groups had serious AEs. No patient died or discontinued treatment due to AEs. The eGFR remained stable throughout the course of treatment in HIV/HCV‐coinfected patients receiving anti‐retroviral therapy containing tenofovir disoproxil fumarate (TDF).
Conclusions
Generic VEL/SOF‐based therapy is well‐tolerated and provides comparably high SVR12 rates for HCV infection in patients with and without HIV coinfection.
Epicardial and abdominal adipose tissues have recently been demonstrated to play inflammatory roles in coronary atherosclerosis. We sought to compare tissue adipocytokine levels of these two ...anatomically distinct adipose stores in patients with and without coronary artery diseases (CAD).
Samples of abdominal and epicardial fat tissues were harvested to detect the levels of adipocytokines and proinflammatory mediators.
Forty-six patients with CAD who underwent coronary artery bypass surgery and 12 non-CAD control subjects who underwent other types of open-heart surgery.
Tissue levels of adipocytokines (adiponectin, leptin and visfatin) and proinflammatory mediators (tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6)) were determined by enzyme-linked immunosorbent assay.
Tissue levels of TNF-alpha, IL-6, leptin and visfatin were significantly higher in CAD patients relative to control subjects. In addition, significantly higher tissue levels of these four cytokines from abdominal fat depots were found compared to those from epicardial fat in CAD patients. Conversely, in comparison with control subjects, tissue levels of adiponectin were significantly reduced in CAD patients with a significantly lower tissue levels of abdominal than epicardial fat depots demonstrated.
Abdominal adiposity may play more significant role than epicardial fat in the pathogenesis of coronary atherosclerosis.
Multi-walled carbon nanotubes, with a typical length of 140 μm and a diameter of 120 nm, have been used to modify an anhydride-cured epoxy polymer. The modulus, fracture energy and the fatigue ...performance of the modified polymers have been investigated. Microscopy showed that these long nanotubes were agglomerated, and that increasing the nanotube content increased the severity of the agglomeration. The addition of nanotubes increased the modulus of the epoxy, but the glass transition temperature was unaffected. The measured fracture energy was also increased, from 133 to 223 J/m
2
with the addition of 0.5 wt% of nanotubes. The addition of the carbon nanotubes also resulted in an increase in the fatigue performance. The threshold strain-energy release-rate,
G
th
, increased from 24 J/m
2
for the unmodified material to 73 J/m
2
for the epoxy with 0.5 wt% of nanotubes. Electron microscopy of the fracture surfaces showed clear evidence of nanotube debonding and pull-out, plus void growth around the nanotubes, in both the fracture and fatigue tests. The modelling study showed that the modified Halpin–Tsai equation can fit very well with the measured values of the Young’s modulus, when the orientation and agglomeration of the nanotubes are considered. The fracture energy of the nanotube-modified epoxies was predicted, by considering the contributions of the toughening mechanisms of nanotube debonding, nanotube pull-out and plastic void growth of the epoxy. This indicated that debonding and pull-out contribute to the toughening effect, but the contribution of void growth is not significant. There was excellent agreement between the predictions and the experimental results.
Management of curable sexually-transmitted infections (STI) such as Chlamydia can be revolutionized by highly sensitive nucleic acid testing that is deployable at the point-of-care (POC). Here we ...report the development of a mobile nucleic acid amplification testing (mobiNAAT) platform utilizing a mobile phone and droplet magnetofluidics to deliver NAAT in a portable and accessible format. By using magnetic particles as a mobile substrate for nucleic acid capture and transport, fluid handling is reduced to particle translocation on a simple magnetofluidic cartridge assembled with reagents for nucleic acid purification and amplification. A mobile phone user interface operating in tandem with a portable Bluetooth-enabled cartridge-processing unit facilitates process integration. We tested 30 potentially Chlamydia trachomatis (CT)-infected patients in a hospital emergency department and confirmed that mobiNAAT showed 100% concordance with laboratory-based NAAT. Concurrent evaluation by a nontechnical study coordinator who received brief training via an embedded mobile app module demonstrated ease of use and reproducibility of the platform. This work demonstrates the potential of mobile nucleic acid testing in bridging the diagnostic gap between centralized laboratories and hospital emergency departments.
PDF
