396 research outputs found
Temperature-heat uncertainty relation for quantum thermometry
We investigate the resource theory for temperature estimation. We demonstrate
that it is the fluctuation of heat that fundamentally determines temperature
precision through the temperature-heat uncertainty relation. Specifically, we
find that heat is divided into trajectory heat and correlation heat, which are
associated with the heat exchange along thermometer's evolution path and the
correlation between the thermometer and the sample, respectively. Based on two
type of thermometers, we show that both of these heat terms are resources for
enhancing temperature precision. Additionally, we demonstrate that the
temperature-heat uncertainty relation is consistent with the well known
temperature-energy uncertainty relation in thermodynamics. By clearly
distinguishing the resources for enhancing estimation precision, our findings
not only explain why various quantum features are crucial for accurate
temperature sensing but also provide valuable insights for designing
ultrahigh-sensitive quantum thermometers.Comment: 6 pages, 1 figur
Quantum Control in Open and Periodically Driven Systems
Quantum technology resorts to efficient utilization of quantum resources to
realize technique innovation. The systems are controlled such that their states
follow the desired manners to realize different quantum protocols. However, the
decoherence caused by the system-environment interactions causes the states
deviating from the desired manners. How to protect quantum resources under the
coexistence of active control and passive decoherence is of significance.
Recent studies have revealed that the decoherence is determined by the feature
of the system-environment energy spectrum: Accompanying the formation of bound
states in the energy spectrum, the decoherence can be suppressed. It supplies a
guideline to control decoherence. Such idea can be generalized to systems under
periodic driving. By virtue of manipulating Floquet bound states in the
quasienergy spectrum, coherent control via periodic driving dubbed as Floquet
engineering has become a versatile tool not only in controlling decoherence,
but also in artificially synthesizing exotic topological phases. We will review
the progress on quantum control in open and periodically driven systems.
Special attention will be paid to the distinguished role played by the bound
states and their controllability via periodic driving in suppressing
decoherence and generating novel topological phases.Comment: A review articl
Ab initio MCDHF calculations of the In and Tl electron affinities and their isotope shifts
We report multiconfiguration Dirac-Hartree-Fock and relativistic
configuration interaction calculations on the Thallium (Tl) electron affinity,
as well as on the excited energy levels arising from the ground configuration
of Tl. The results are compared with the available experimental values and
further validated by extending the study to its homologous, lighter element,
Indium (In), belonging to Group 13 (III.A) of the periodic table. The
calculated electron affinities of In and Tl, 383.4 and 322.8 meV, agree with
the latest measurements by within 1\%. Three bound states are
confirmed in the configuration of In while only the ground state
is bound in the configuration of Tl. The isotope
shifts on the In and Tl electron affinities are also estimated. The E2/M1
intraconfiguration radiative transition rates within 5s^25p^2 \; ^3P_{0,1,2}
of In are used to calculate the radiative lifetimes of the metastable
levels
miR-15a and miR-16-1 inhibit the proliferation of leukemic cells by down-regulating WT1 protein level
<p>Abstract</p> <p>Background</p> <p>miR-15a and miR-16-1(miR-15a/16-1) have been implicated as tumor suppressors in chronic lymphocytic leukemia, multiple myeloma, and acute myeloid leukemic cells. However the mechanism of inhibiting the proliferation of leukemic cells is poorly understood.</p> <p>Methods</p> <p>K562 and HL-60 cells were transfected with pRS-15/16 or pRS-E, cell growth were measured by CCK-8 assay and direct cell count. Meanwhile WT1 protein and mRNA level were measured by Western blotting and quantitative real-time PCR.</p> <p>Results</p> <p>In this study we found that over-expression of miR-15a/16-1 significantly inhibited K562 and HL-60 cells proliferation. Enforced expression of miR-15a/16-1 in K562 and HL-60 cells significantly reduced the protein level of WT1 but not affected the mRNA level. However enforced expression of miR-15a/16-1 can not reduce the activity of a luciferase reporter carrying the 3'-untranslated region(3'UTR) of WT1. Silencing of WT1 by specific siRNA suppressed leukemic cells proliferation resembling that of miR-15a/16-1 over-expression. Anti-miR-15a/16-1 oligonucleotides (AMO) reversed the expression of WT1 in K562 and HL-60 cells. Finally, we found a significant inverse correlation between miR-15a or miR-16-1 expression and WT1 protein levels in primary acute myeloid leukemia (AML) blasts and normal controls.</p> <p>Conclusions</p> <p>These data suggest that miR-15a/16-1 may function as a tumor suppressor to regulate leukemic cell proliferation potentially by down-regulating the WT1 oncogene. However WT1 is not directly targeted by miR-15a/16-1 through miRNA-mRNA base pairing, therefore more study are required to understand the mechanism by which miR-15a/16-1 downregulate WT1.</p
Intrahepatic HBV DNA as a predictor of antivirus treatment efficacy in HBeAg-positive chronic hepatitis B patients
AIM:
To evaluate the effect of antiviral agents on intrahepatic HBV DNA in HBeAg-positive chronic hepatitis B patients.
METHODS:
Seventy-one patients received treatment with lamivudine, interferon alpha (IFN-alpha 2b) or sequential therapy with lamivudine-IFN-alpha 2b for 48 wk. All subjects were followed up for 24 wk. Serum and intrahepatic HBV DNA were measured quantitatively by PCR. HBV genotypes were analyzed by PCR-RFLP.
RESULTS:
At the end of treatment, the intrahepatic HBV DNA level in 71 patients decreased from a mean of (6.1 +/- 1.0) log10 to (4.9 +/- 1.4) log10. Further, a larger decrease was seen in the intrahepatic HBV DNA level in patients with HBeAg seroconversion. Intrahepatic HBV DNA level (before and after treatment) was not significantly affected by the patients' HBV genotype, or by the probability of virological flare after treatment.
CONCLUSION:
Intrahepatic HBV DNA can be effectively lowered by antiviral agents and is a significant marker for monitoring antivirus treatment. Low intrahepatic HBV DNA level may achieve better efficacy of antivirus treatment
Demonstration of Adiabatic Variational Quantum Computing with a Superconducting Quantum Coprocessor
Adiabatic quantum computing enables the preparation of many-body ground
states. This is key for applications in chemistry, materials science, and
beyond. Realisation poses major experimental challenges: Direct analog
implementation requires complex Hamiltonian engineering, while the digitised
version needs deep quantum gate circuits. To bypass these obstacles, we suggest
an adiabatic variational hybrid algorithm, which employs short quantum circuits
and provides a systematic quantum adiabatic optimisation of the circuit
parameters. The quantum adiabatic theorem promises not only the ground state
but also that the excited eigenstates can be found. We report the first
experimental demonstration that many-body eigenstates can be efficiently
prepared by an adiabatic variational algorithm assisted with a multi-qubit
superconducting coprocessor. We track the real-time evolution of the ground and
exited states of transverse-field Ising spins with a fidelity up that can reach
about 99%.Comment: 12 pages, 4 figure
Screening and characterization of Bacillus velezensis LB-Y-1 toward selection as a potential probiotic for poultry with multi-enzyme production property
Bacillus spp. have gained increasing recognition as an option to use as antimicrobial growth promoters, which are characterized by producing various enzymes and antimicrobial compounds. The present study was undertaken to screen and evaluate a Bacillus strain with the multi-enzyme production property for poultry production. LB-Y-1, screened from the intestines of healthy animals, was revealed to be a Bacillus velezensis by the morphological, biochemical, and molecular characterization. The strain was screened out by a specific screening program, possessed excellent multi-enzyme production potential, including protease, cellulase, and phytase. Moreover, the strain also exhibited amylolytic and lipolytic activity in vitro. The dietary LB-Y-1 supplementation improved growth performance and tibia mineralization in chicken broilers, and increased serum albumin and serum total protein at 21 days of age (p < 0.05). Besides, LB-Y-1 enhanced the activity of serum alkaline phosphatase and digestive enzyme in broilers at 21 and 42 days of age (p < 0.05). Analysis of intestinal microbiota showed that a higher community richness (Chao1 index) and diversity (Shannon index) in the LB-Y-1 supplemented compared with the CON group. PCoA analysis showed that the community composition and structure were distinctly different between the CON and LB-Y-1 group. The beneficial genera such as Parasutterella and Rikenellaceae were abundant, while the opportunistic pathogen such as Escherichia-Shigella were reduced in the LB-Y-1 supplemented group (p < 0.05). Collectively, LB-Y-1 can be considered as a potential strain for further utilization in direct-fed microbial or starter culture for fermentation
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