77 research outputs found
Data-Driven Energy Levels Calculation of Neutral Ytterbium ( = 70)
In view of the difficulty in calculating the atomic structure parameters of
high- elements, the HFR (Hartree-Fock with relativistic corrections) theory
in combination with the ridge regression (RR) algorithm rather than the Cowan
code's least squares fitting (LSF) method is proposed and applied. By analyzing
the energy level structure parameters of the HFR theory and using the fitting
experimental energy level extrapolation method, some excited state energy
levels of the {Yb~I} () atom including the open shell are
calculated. The advantages of the ridge regression algorithm are demonstrated
by comparing it with Cowan's least squares results. In addition, the results
obtained by the new method are compared with the experimental results and other
theoretical results to demonstrate the reliability and accuracy of our
approach
Efficient display of active lipase LipB52 with a Pichia pastoris cell surface display system and comparison with the LipB52 displayed on Saccharomyces cerevisiae cell surface
<p>Abstract</p> <p>Background</p> <p>For industrial bioconversion processes, the utilization of surface-displayed lipase in the form of whole-cell biocatalysts is more advantageous, because the enzymes are displayed on the cell surface spontaneously, regarded as immobilized enzymes.</p> <p>Results</p> <p>Two <it>Pichia pastoris </it>cell surface display vectors based on the flocculation functional domain of FLO with its own secretion signal sequence or the α-factor secretion signal sequence were constructed respectively. The lipase gene <it>lipB52 </it>fused with the <it>FLO </it>gene was successfully transformed into <it>Pichia pastoris </it>KM71. The lipase LipB52 was expressed under the control of the <it>AOX1 </it>promoter and displayed on <it>Pichia pastoris </it>KM71 cell surface with the two <it>Pichia pastoris </it>cell surface display vectors. Localization of the displayed LipB52 on the cell surface was confirmed by the confocal laser scanning microscopy (CLSM). The LipB52 displayed on the <it>Pichia pastoris </it>cell surface exhibited activity toward <it>p</it>-nitrophenol ester with carbon chain length ranging from C<sub>10 </sub>to C<sub>18</sub>, and the optimum substrate was <it>p</it>-nitrophenol-caprate (C<sub>10</sub>), which was consistent with it displayed on the <it>Saccharomyces cerevisiae </it>EBY100 cell surface. The hydrolysis activity of lipase LipB52 displayed on <it>Pichia pastoris </it>KM71-pLHJ047 and KM71-pLHJ048 cell surface reached 94 and 91 U/g dry cell, respectively. The optimum temperature of the displayed lipases was 40°C at pH8.0, they retained over 90% activity after incubation at 60°C for 2 hours at pH 7.0, and still retained 85% activity after incubation for 3 hours.</p> <p>Conclusion</p> <p>The LipB52 displayed on the <it>Pichia pastoris </it>cell surface exhibited better stability than the lipase LipB52 displayed on <it>Saccharomyces cerevisiae </it>cell surface. The displayed lipases exhibited similar transesterification activity. But the <it>Pichia pastoris </it>dry cell weight per liter (DCW/L) ferment culture was about 5 times than <it>Saccharomyces cerevisiae</it>, the lipase displayed on <it>Pichia pastoris </it>are more suitable for whole-cell biocatalysts than that displayed on <it>Saccharomyces cerevisiae </it>cell surface.</p
Enhanced quantum sensing with amplification and deamplification
Quantum sensing is a fundamental building block of modern technology that
employs quantum resources and creates new opportunities for precision
measurements. However, previous methods usually have a common assumption that
detection noise levels should be below the intrinsic sensitivity provided by
quantum resources. Here we report the first demonstration of Fano resonance
between coupled alkali-metal and noble gases through rapid spin-exchange
collisions. The Fano resonance gives rise to two intriguing phenomena: spin
amplification and deamplification, which serve as crucial resources for
enhanced sensing. Further we develop a novel scheme of quantum sensing enhanced
by amplification and deamplification, with relaxed requirements on the
detection noise. The coupled systems of alkali-metal and noble gases act as
amplifiers or de-amplifiers, enabling to extract small signals above the
detection noise before final detection. We demonstrate magnetic-field
measurement about 54 decibels below the photon-shot noise, which outperforms
the state-of-the-art squeezed-light technology and realizes femtotesla-level
sensitivity. Our work opens new avenues to applications in searches for
ultralight dark matter with sensitivity well beyond the supernova-observation
constraints.Comment: 7 pages, 4 figure
All-in-One: A Highly Representative DNN Pruning Framework for Edge Devices with Dynamic Power Management
During the deployment of deep neural networks (DNNs) on edge devices, many
research efforts are devoted to the limited hardware resource. However, little
attention is paid to the influence of dynamic power management. As edge devices
typically only have a budget of energy with batteries (rather than almost
unlimited energy support on servers or workstations), their dynamic power
management often changes the execution frequency as in the widely-used dynamic
voltage and frequency scaling (DVFS) technique. This leads to highly unstable
inference speed performance, especially for computation-intensive DNN models,
which can harm user experience and waste hardware resources. We firstly
identify this problem and then propose All-in-One, a highly representative
pruning framework to work with dynamic power management using DVFS. The
framework can use only one set of model weights and soft masks (together with
other auxiliary parameters of negligible storage) to represent multiple models
of various pruning ratios. By re-configuring the model to the corresponding
pruning ratio for a specific execution frequency (and voltage), we are able to
achieve stable inference speed, i.e., keeping the difference in speed
performance under various execution frequencies as small as possible. Our
experiments demonstrate that our method not only achieves high accuracy for
multiple models of different pruning ratios, but also reduces their variance of
inference latency for various frequencies, with minimal memory consumption of
only one model and one soft mask
Predictors of lung adenocarcinoma with leptomeningeal metastases: A 2022 targeted-therapy-assisted molGPA model
Objective: To explore prognostic indicators of lung adenocarcinoma with leptomeningeal metastases (LM) and provide an updated graded prognostic assessment model integrated with molecular alterations (molGPA).
Methods: A cohort of 162 patients was enrolled from 202 patients with lung adenocarcinoma and LM. By randomly splitting data into the training (80%) and validation (20%) sets, the Cox regression and random survival forest methods were used on the training set to identify statistically significant variables and construct a prognostic model. The C-index of the model was calculated and compared with that of previous molGPA models.
Results: The Cox regression and random forest models both identified four variables, which included KPS, LANO neurological assessment, TKI therapy line, and controlled primary tumor, as statistically significant predictors. A novel targeted-therapy-assisted molGPA model (2022) using the above four prognostic factors was developed to predict LM of lung adenocarcinoma. The C-indices of this prognostic model in the training and validation sets were higher than those of the lung-molGPA (2017) and molGPA (2019) models.
Conclusions: The 2022 molGPA model, a substantial update of previous molGPA models with better prediction performance, may be useful in clinical decision making and stratification of future clinical trials
Spatiotemporal patterns and spatial risk factors for visceral leishmaniasis from 2007 to 2017 in Western and Central China: a modelling analysis
Visceral leishmaniasis (VL) is a neglected disease caused by trypanosomatid protozoa in the genus Leishmania, which is transmitted by phlebotomine sandflies. Although this vector-borne disease has been eliminated in several regions of China during the last century, the reported human VL cases have rebounded in Western and Central China in recent decades. However, understanding of the spatial epidemiology of the disease remains vague, as the spatial risk factors driving the spatial heterogeneity of VL. In this study, we analyzed the spatiotemporal patterns of annual human VL cases in Western and Central China from 2007 to 2017. Based on the related spatial maps, the boosted regression tree (BRT) model was adopted to explore the relationships between VL and spatial correlates as well as predicting both the existing and potential infection risk zones of VL in Western and Central China. The mined links reveal that elevation, minimum temperature, relative humidity, and annual accumulated precipitation make great contributions to the spatial heterogeneity of VL. The maps show that Xinjiang Uygur Autonomous Region, Gansu, western Inner Mongolia Autonomous Region, and Sichuan are predicted to fall in the highest infection risk zones of VL. Approximately 61.60 million resident populations lived in the high-risk regions of VL in Western and Central China. Our results provide a better understanding of how spatial risk factors driving VL spread as well as identifying the potential endemic risk region of VL, thereby enhancing the biosurveillance capacity of public health authorities
SAPPHIRE: Search for exotic parity-violation interactions with quantum spin amplifiers
Quantum sensing provides sensitive tabletop tools to search for exotic
spin-dependent interactions beyond the Standard Model, which has attracted
great attention in theories and experiments. Here we develop a technique based
on quantum Spin Amplifier for Particle PHysIcs REsearch (SAPPHIRE) to
resonantly search for exotic interactions, specifically parity-odd spin-spin
interactions. The present technique effectively amplifies the pseudomagnetic
field generated by exotic interactions by a factor of about 200 while being
insensitive to spurious external magnetic fields. Our studies, using such a
quantum amplification technique, open the doors to exploring the
parity-violation interactions mediated by Z' bosons in the challenging
parameter space (force range between 3 mm and 0.1 km) and set the most
stringent constraints on Z'-mediated electron-neutron couplings, significantly
improving previous limits by up to five orders of magnitude. Moreover, our
bounds on Z'-mediated couplings between nucleons reaches into a hitherto
unexplored parameter space (force range below 1 m), complementing the existing
astrophysical and laboratory studies.Comment: 8 pages, 5 figure
Knockdown of Akt Sensitizes Osteosarcoma Cells to Apoptosis Induced by Cisplatin Treatment
Akt plays an important role in the inhibition of apoptosis induced by chemotherapy and other stimuli. We therefore investigated if knockdown of Akt2 promoted drug-induced apoptosis in cultured osteosarcoma cells in vitro. SAOS-2 cells were transfected with Akt2 siRNA. The sensitivity of the transformed cell line to the chemotherapeutic drug cisplatin was assessed. Reduced expression of Akt2 did not directly inhibit the growth rate of the transfected cells; however, it significantly increased their sensitivity to cisplatin. Knockdown of Akt2, together with cisplatin treatment, promoted the expression of p53 up-regulated modulator of apoptosis (PUMA). It is possible that the augmentation of cisplatin cytotoxicity may be mediated by PUMA activation. The results of this study suggest that knockdown of Akt2 expression may have therapeutic applications in enhancing the efficacy of chemotherapy in patients with osteosarcoma
Single-cell RNA sequencing reveals cell type-specific immune regulation associated with human neuromyelitis optica spectrum disorder
IntroductionOne rare type of autoimmune disease is called neuromyelitis optica spectrum disorder (NMOSD) and the peripheral immune characteristics of NMOSD remain unclear.MethodsHere, single-cell RNA sequencing (scRNA-seq) is used to characterize peripheral blood mononuclear cells from individuals with NMOSD.ResultsThe differentiation and activation of lymphocytes, expansion of myeloid cells, and an excessive inflammatory response in innate immunity are observed. Flow cytometry analyses confirm a significant increase in the percentage of plasma cells among B cells in NMOSD. NMOSD patients exhibit an elevated percentage of CD8+ T cells within the T cell population. Oligoclonal expansions of B cell receptors are observed after therapy. Additionally, individuals with NMOSD exhibit elevated expression of CXCL8, IL7, IL18, TNFSF13, IFNG, and NLRP3.DiscussionPeripheral immune response high-dimensional single-cell profiling identifies immune cell subsets specific to a certain disease and identifies possible new targets for NMOSD
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