1,554 research outputs found
Synthesis of (+)-Cortistatin A
Steroids have historically elicited attention from the chemical sciences owing to their utility in living systems, as well as their intrinsic and diverse beauty.1 The cortistatin family (Figure 1, 1-7 and others),2 a collection of unusual, marine 9-(10,19)-abeo-androstane steroids, is certainly no exception; aside from challenging stereochemistry and an odd bricolage of functional groups, the salient feature of these sponge metabolites is, inescapably, their biological activity. Cortistatin A, the most potent member of the small family, inhibits the proliferation of human umbilical vein endothelial cells (HUVECs, IC50) 1.8 nM), evidently with no general toxicity toward either healthy or cancerous cell lines (IC50(testing cells)/IC50(HUVECs) g 3300).2a From initial pharmacological studies, binding appears to occur reversibly, but to an unknown target, inhibiting the phosphorylation of an unidentified 110 kDa protein, and implying a pathway that may be unique to know
Practical experimental certification of computational quantum gates via twirling
Due to the technical difficulty of building large quantum computers, it is
important to be able to estimate how faithful a given implementation is to an
ideal quantum computer. The common approach of completely characterizing the
computation process via quantum process tomography requires an exponential
amount of resources, and thus is not practical even for relatively small
devices. We solve this problem by demonstrating that twirling experiments
previously used to characterize the average fidelity of quantum memories
efficiently can be easily adapted to estimate the average fidelity of the
experimental implementation of important quantum computation processes, such as
unitaries in the Clifford group, in a practical and efficient manner with
applicability in current quantum devices. Using this procedure, we demonstrate
state-of-the-art coherent control of an ensemble of magnetic moments of nuclear
spins in a single crystal solid by implementing the encoding operation for a 3
qubit code with only a 1% degradation in average fidelity discounting
preparation and measurement errors. We also highlight one of the advances that
was instrumental in achieving such high fidelity control.Comment: 7 pages, 6 figure
Randomized benchmarking of single and multi-qubit control in liquid-state NMR quantum information processing
Being able to quantify the level of coherent control in a proposed device
implementing a quantum information processor (QIP) is an important task for
both comparing different devices and assessing a device's prospects with
regards to achieving fault-tolerant quantum control. We implement in a
liquid-state nuclear magnetic resonance QIP the randomized benchmarking
protocol presented by Knill et al (PRA 77: 012307 (2008)). We report an error
per randomized pulse of with a
single qubit QIP and show an experimentally relevant error model where the
randomized benchmarking gives a signature fidelity decay which is not possible
to interpret as a single error per gate. We explore and experimentally
investigate multi-qubit extensions of this protocol and report an average error
rate for one and two qubit gates of for a three
qubit QIP. We estimate that these error rates are still not decoherence limited
and thus can be improved with modifications to the control hardware and
software.Comment: 10 pages, 6 figures, submitted versio
Use GPT-J Prompt Generation with RoBERTa for NER Models on Diagnosis Extraction of Periodontal Diagnosis from Electronic Dental Records
This study explored the usability of prompt generation on named entity
recognition (NER) tasks and the performance in different settings of the
prompt. The prompt generation by GPT-J models was utilized to directly test the
gold standard as well as to generate the seed and further fed to the RoBERTa
model with the spaCy package. In the direct test, a lower ratio of negative
examples with higher numbers of examples in prompt achieved the best results
with a F1 score of 0.72. The performance revealed consistency, 0.92-0.97 in the
F1 score, in all settings after training with the RoBERTa model. The study
highlighted the importance of seed quality rather than quantity in feeding NER
models. This research reports on an efficient and accurate way to mine clinical
notes for periodontal diagnoses, allowing researchers to easily and quickly
build a NER model with the prompt generation approach.Comment: 2023 AMIA Annual Symposium, see
https://amia.org/education-events/amia-2023-annual-symposiu
Use GPT-J Prompt Generation with RoBERTa for NER Models on Diagnosis Extraction of Periodontal Diagnosis from Electronic Dental Records
This study explored the usability of prompt generation on named entity recognition (NER) tasks and the performance in different settings of the prompt. The prompt generation by GPT-J models was utilized to directly test the gold standard as well as to generate the seed and further fed to the RoBERTa model with the spaCy package. In the direct test, a lower ratio of negative examples with higher numbers of examples in prompt achieved the best results with a F1 score of 0.72. The performance revealed consistency, 0.92-0.97 in the F1 score, in all settings after training with the RoBERTa model. The study highlighted the importance of seed quality rather than quantity in feeding NER models. This research reports on an efficient and accurate way to mine clinical notes for periodontal diagnoses, allowing researchers to easily and quickly build a NER model with the prompt generation approach
Extracting periodontitis diagnosis in clinical notes with RoBERTa and regular expression
This study aimed to utilize text processing and natural language processing
(NLP) models to mine clinical notes for the diagnosis of periodontitis and to
evaluate the performance of a named entity recognition (NER) model on different
regular expression (RE) methods. Two complexity levels of RE methods were used
to extract and generate the training data. The SpaCy package and RoBERTa
transformer models were used to build the NER model and evaluate its
performance with the manual-labeled gold standards. The comparison of the RE
methods with the gold standard showed that as the complexity increased in the
RE algorithms, the F1 score increased from 0.3-0.4 to around 0.9. The NER
models demonstrated excellent predictions, with the simple RE method showing
0.84-0.92 in the evaluation metrics, and the advanced and combined RE method
demonstrating 0.95-0.99 in the evaluation. This study provided an example of
the benefit of combining NER methods and NLP models in extracting target
information from free-text to structured data and fulfilling the need for
missing diagnoses from unstructured notes.Comment: IEEE ICHI 2023, see https://ieeeichi.github.io/ICHI2023/program.htm
Efficient measurement of quantum gate error by interleaved randomized benchmarking
We describe a scalable experimental protocol for obtaining estimates of the
error rate of individual quantum computational gates. This protocol, in which
random Clifford gates are interleaved between a gate of interest, provides a
bounded estimate of the average error of the gate under test so long as the
average variation of the noise affecting the full set of Clifford gates is
small. This technique takes into account both state preparation and measurement
errors and is scalable in the number of qubits. We apply this protocol to a
superconducting qubit system and find gate errors that compare favorably with
the gate errors extracted via quantum process tomography.Comment: 5 pages, 2 figures, published versio
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Drug target optimization in chronic myeloid leukemia using innovative computational platform.
Chronic Myeloid Leukemia (CML) represents a paradigm for the wider cancer field. Despite the fact that tyrosine kinase inhibitors have established targeted molecular therapy in CML, patients often face the risk of developing drug resistance, caused by mutations and/or activation of alternative cellular pathways. To optimize drug development, one needs to systematically test all possible combinations of drug targets within the genetic network that regulates the disease. The BioModelAnalyzer (BMA) is a user-friendly computational tool that allows us to do exactly that. We used BMA to build a CML network-model composed of 54 nodes linked by 104 interactions that encapsulates experimental data collected from 160 publications. While previous studies were limited by their focus on a single pathway or cellular process, our executable model allowed us to probe dynamic interactions between multiple pathways and cellular outcomes, suggest new combinatorial therapeutic targets, and highlight previously unexplored sensitivities to Interleukin-3.We would like to thank the members of the Fisher laboratory, in particular to Gavin Smyth
and Caroline Dahl for their help with the BMA development, and Alex Hajnal for valuable
comments on the manuscript and insightful discussions. Research in BG laboratory is
supported by the Medical Research Council, Leukaemia and Lymphoma Research, The
Leukemia and Lymphoma Society, Microsoft Research and core support grants by the
Wellcome Trust to the Cambridge Institute for Medical Research and Wellcome
Trust-MRC Cambridge Stem Cell Institute.This is the final published version. It was originally published in Scientific Reports 5: 8190. DOI: 10.1038/srep08190
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