46 research outputs found
Harnessing graph state resources for robust quantum magnetometry under noise
Precise measurement of magnetic fields is essential for various applications,
such as fundamental physics, space exploration, and biophysics. Although recent
progress in quantum engineering has assisted in creating advanced quantum
magnetometers, there are still ongoing challenges in improving their efficiency
and noise resistance. This study focuses on using symmetric graph state
resources for quantum magnetometry to enhance measurement precision by
analyzing the estimation theory under Markovian and non-Markovian noise models.
The results show a significant improvement in estimating both single and
multiple Larmor frequencies. In single Larmor frequency estimation, the quantum
Fisher information spans a spectrum from the standard quantum limit to the
Heisenberg limit within a periodic range of the Larmor frequency, and in the
case of multiple Larmor frequencies, it can exceed the standard quantum limit
for both Markovian and non-Markovian noise. This study highlights the potential
of graph state-based methods for improving magnetic field measurements under
noisy environments.Comment: 10 pages, 7 figure
An in-situ thermoelectric measurement apparatus inside a thermal-evaporator
At the ultra-thin limit below 20 nm, a film's electrical conductivity,
thermal conductivity, or thermoelectricity depends heavily on its thickness. In
most studies, each sample is fabricated one at a time, potentially leading to
considerable uncertainty in later characterizations. We design and build an
in-situ apparatus to measure thermoelectricity during their deposition inside a
thermal evaporator. A temperature difference of up to 2 K is generated by a
current passing through an on-chip resistor patterned using photolithography.
The Seebeck voltage is measured on a Hall bar structure of a film deposited
through a shadow mask. The measurement system is calibrated carefully before
loading into the thermal evaporator. This in-situ thermoelectricity measurement
system has been thoroughly tested on various materials, including Bi, Te, and
BiTe, at high temperatures up to 500 K
Associations of Underlying Health Conditions With Anxiety and Depression Among Outpatients: Modification Effects of Suspected COVID-19 Symptoms, Health-Related and Preventive Behaviors
Objectives: We explored the association of underlying health conditions (UHC) with depression and anxiety, and examined the modification effects of suspected COVID-19 symptoms (S-COVID-19-S), health-related behaviors (HB), and preventive behaviors (PB).Methods: A cross-sectional study was conducted on 8,291 outpatients aged 18–85 years, in 18 hospitals and health centers across Vietnam from 14th February to May 31, 2020. We collected the data regarding participant's characteristics, UHC, HB, PB, depression, and anxiety.Results: People with UHC had higher odds of depression (OR = 2.11; p < 0.001) and anxiety (OR = 2.86; p < 0.001) than those without UHC. The odds of depression and anxiety were significantly higher for those with UHC and S-COVID-19-S (p < 0.001); and were significantly lower for those had UHC and interacted with “unchanged/more” physical activity (p < 0.001), or “unchanged/more” drinking (p < 0.001 for only anxiety), or “unchanged/healthier” eating (p < 0.001), and high PB score (p < 0.001), as compared to those without UHC and without S-COVID-19-S, “never/stopped/less” physical activity, drinking, “less healthy” eating, and low PB score, respectively.Conclusion: S-COVID-19-S worsen psychological health in patients with UHC. Physical activity, drinking, healthier eating, and high PB score were protective factors
Validation and utilization of an internally controlled multiplex Real-time RT-PCR assay for simultaneous detection of enteroviruses and enterovirus A71 associated with hand foot and mouth disease
BACKGROUND: Hand foot and mouth disease (HFMD) is a disease of public health importance across the Asia-Pacific region. The disease is caused by enteroviruses (EVs), in particular enterovirus A71 (EV-A71). In EV-A71-associated HFMD, the infection is sometimes associated with severe manifestations including neurological involvement and fatal outcome. The availability of a robust diagnostic assay to distinguish EV-A71 from other EVs is important for patient management and outbreak response. METHODS: We developed and validated an internally controlled one-step single-tube real-time RT-PCR in terms of sensitivity, linearity, precision, and specificity for simultaneous detection of EVs and EV-A71. Subsequently, the assay was then applied on throat and rectal swabs sampled from 434 HFMD patients. RESULTS: The assay was evaluated using both plasmid DNA and viral RNA and has shown to be reproducible with a maximum assay variation of 4.41 % and sensitive with a limit of detection less than 10 copies of target template per reaction, while cross-reactivity with other EV serotypes was not observed. When compared against a published VP1 nested RT-PCR using 112 diagnostic throat and rectal swabs from 112 children with a clinical diagnosis of HFMD during 2014, the multiplex assay had a higher sensitivity and 100 % concordance with sequencing results which showed EVs in 77/112 (68.8 %) and EV-A71 in 7/112 (6.3 %). When applied to clinical diagnostics for 322 children, the assay detected EVs in throat swabs of 257/322 (79.8 %) of which EV-A71 was detected in 36/322 (11.2 %) children. The detection rate increased to 93.5 % (301/322) and 13.4 % (43/322) for EVs and EV-A71, respectively, when rectal swabs from 65 throat-negative children were further analyzed. CONCLUSION: We have successfully developed and validated a sensitive internally controlled multiplex assay for rapid detection of EVs and EV-A71, which is useful for clinical management and outbreak control of HFMD. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12985-015-0316-2) contains supplementary material, which is available to authorized users
AI is a viable alternative to high throughput screening: a 318-target study
: High throughput screening (HTS) is routinely used to identify bioactive small molecules. This requires physical compounds, which limits coverage of accessible chemical space. Computational approaches combined with vast on-demand chemical libraries can access far greater chemical space, provided that the predictive accuracy is sufficient to identify useful molecules. Through the largest and most diverse virtual HTS campaign reported to date, comprising 318 individual projects, we demonstrate that our AtomNet® convolutional neural network successfully finds novel hits across every major therapeutic area and protein class. We address historical limitations of computational screening by demonstrating success for target proteins without known binders, high-quality X-ray crystal structures, or manual cherry-picking of compounds. We show that the molecules selected by the AtomNet® model are novel drug-like scaffolds rather than minor modifications to known bioactive compounds. Our empirical results suggest that computational methods can substantially replace HTS as the first step of small-molecule drug discovery
In Defense of Scene Graphs for Image Captioning
The mainstream image captioning models rely on Convolutional Neural Network (CNN) image features to generate captions via recurrent models. Recently, image scene graphs have been used to augment captioning models so as to leverage their structural semantics, such as object entities, relationships and attributes. Several studies have noted that the naive use of scene graphs from a black-box scene graph generator harms image captioning performance and that scene graph-based captioning models have to incur the overhead of explicit use of image features to generate decent captions. Addressing these challenges, we propose SG2Caps, a framework that utilizes only the scene graph labels for competitive image captioning performance. The basic idea is to close the semantic gap between the two scene graphs - one derived from the input image and the other from its caption. In order to achieve this, we leverage the spatial location of objects and the Human-Object-Interaction (HOI) labels as an additional HOI graph. SG2Caps outperforms existing scene graph-only captioning models by a large margin, indicating scene graphs as a promising representation for image captioning. Direct utilization of scene graph labels avoids expensive graph convolutions over high-dimensional CNN features resulting in 49% fewer trainable parameters. Our code is available at: https://github.com/Kien085/SG2Caps
Variational quantum metrology for multiparameter estimation under dephasing noise
We present a hybrid quantum-classical variational scheme to enhance precision
in quantum metrology. In the scheme, both the initial state and the measurement
basis in the quantum part are parameterized and optimized via the classical
part. It enables the maximization of information gained about the measured
quantity. We discuss specific applications to 3D magnetic field sensing under
several dephasing noise modes. Indeed, we demonstrate its ability to
simultaneously estimate all parameters and surpass the standard quantum limit,
making it a powerful tool for metrological applications.Comment: 7 pages, 7 figure
FIGURE 1 in A new species of the genus Theloderma Tschudi, 1838 (Anura: Rhacophoridae) from Northwestern Vietnam
FIGURE 1. Collection locality in Vietnam: Van Ban District, Nam Tha Commune, Lao Cai Province, (1)
The effects of drying conditions on bioactive compounds and antioxidant activity of the Australian maroon bush, Scaevola spinescens
Scaevola spinescens is a native Australian plant that has traditionally been used for medical purposes. This study aimed to determine the impact of different drying conditions on the bioactive compound yield and antioxidant activity in dried S. spinescens. The results showed that different drying conditions significantly affected total phenolics, flavonoids, saponins and antioxidant activity. Microwave irradiation at 240 W retained the highest levels of total phenolics (45.82 mg GAE/g), whereas hot air‐drying at 110°C and vacuum oven drying at 90°C retained the highest levels of saponins (150.72 mg ESE/g and 146.61 mg ESE/g, respectively) and antioxidant activity. Per kWh of energy consumed, microwave drying at 240 W for 600 s had dramatically higher yields than all other methods tested (~4,700 times more efficient than freeze drying and ~66 times more efficient than hot air or vacuum oven drying), and therefore is recommended for drying S. spinescens