Speed limits and locality in many-body quantum dynamics

We review the mathematical speed limits on quantum information processing in many-body systems. After the proof of the Lieb-Robinson Theorem in 1972, the past two decades have seen substantial developments in its application to other questions, such as the simulatability of quantum systems on classical or quantum computers, the generation of entanglement, and even the properties of ground states of gapped systems. Moreover, Lieb-Robinson bounds have been extended in non-trivial ways, to demonstrate speed limits in systems with power-law interactions or interacting bosons, and even to prove notions of locality that arise in cartoon models for quantum gravity with all-to-all interactions. We overview the progress which has occurred, highlight the most promising results and techniques, and discuss some central outstanding questions which remain open. To help bring newcomers to the field up to speed, we provide self-contained proofs of the field's most essential results.Comment: review article. 93 pages, 10 figures, 1 table. v2: minor change

Constraints on a special running vacuum model

Funder: Physics Division, National Center for Theoretical Sciences; doi: http://dx.doi.org/10.13039/100009638Abstract: We study a special running vacuum model (RVM) with Λ=3αH2+3βH04H-2+Λ0, where α, β and Λ0 are the model parameters and H is the Hubble one. This RVM has non-analytic background solutions for the energy densities of matter and radiation, which can only be evaluated numerically. From the analysis of the CMB power spectrum and baryon acoustic oscillation along with the prior of α>0 to avoid having a negative dark energy density, we find that α<2.83×10-4 and β=(-0.2-4.5+3.9)×10-4 (95% C.L.). We show that the RVM fits the cosmological data comparably to the ΛCDM. In addition, we relate the fluctuation amplitude σ8 to the neutrino mass sum Σmν

A Phase-Coded Time-Domain Interleaved OTFS Waveform with Improved Ambiguity Function

Integrated sensing and communication (ISAC) is a significant application scenario in future wireless communication networks, and sensing capability of a waveform is always evaluated by the ambiguity function. To enhance the sensing performance of the orthogonal time frequency space (OTFS) waveform, we propose a novel time-domain interleaved cyclic-shifted P4-coded OTFS (TICP4-OTFS) with improved ambiguity function. TICP4-OTFS can achieve superior autocorrelation features in both the time and frequency domains by exploiting the multicarrier-like form of OTFS after interleaved and the favorable autocorrelation attributes of the P4 code. Furthermore, we present the vectorized formulation of TICP4-OTFS modulation as well as its signal structure in each domain. Numerical simulations show that our proposed TICP4-OTFS waveform outperforms OTFS with a narrower mainlobe as well as lower and more distant sidelobes in terms of delay and Doppler-dimensional ambiguity functions, and an instance of range estimation using pulse compression is illustrated to exhibit the proposed waveform\u2019s greater resolution. Besides, TICP4-OTFS achieves better performance of bit error rate for communication in low signal-to-noise ratio (SNR) scenarios.Comment: This paper has been accepted by 2023 IEEE Globecom Workshops (GC Wkshps): Workshop on Integrated Sensing and Communications for Internet of Thing

Survival Outcomes of Patients with Esophageal Cancer Who Did Not Proceed to Surgery after Neoadjuvant Treatment

Background: This retrospective study examined outcomes in esophageal squamous cell carcinoma (ESCC) patients who did not undergo surgical resection after neoadjuvant chemoradiotherapy (nCRT). Methods: Patients receiving nCRT between 2012 and 2020 were divided into two groups: group 1 (scheduled surgery) and group 2 (no surgery). Group 2 was further categorized into subgroups based on reasons for not proceeding to surgery: group 2a (disease progression), group 2b (poor general conditions), and group 2c (patient refusal). Overall survival (OS) was the primary outcome. Results: Group 1 comprised 145 patients, while subgroups 2a, 2b, and 2c comprised 24, 16, and 31 patients, respectively. The 3-year OS rate was significantly lower in group 2 compared with group 1 (34% versus 56%, p &lt; 0.001). A subgroup analysis showed varying 3-year OS rates: 13% for group 2a, 25% for group 2b, and 58% for group 2c (p &lt; 0.001). Propensity score matching for group 2c and group 1 revealed no significant difference in 3-year OS rates (p = 0.91). Conclusion: One-third of ESCC patients receiving nCRT did not undergo surgical resection. Overall survival in this group was generally poorer, except for those who refused surgery (group 2c).</p

Resveratrol Downregulates Interleukin-6-Stimulated Sonic Hedgehog Signaling in Human Acute Myeloid Leukemia

IL-6 and sonic hedgehog (Shh) signaling molecules are considered to maintain the growth of cancer stem cells (CSCs). Resveratrol, an important integrant in traditional Chinese medicine, possesses certain antitumor effects. However, the mechanisms on regulating acute myeloid leukemia (AML) are unclear. This study first used human subjects to demonstrate that the plasma levels of IL-6 and IL-1β in AML patients were higher and lower, respectively, than healthy donors. The expression of Shh preproproteins, and C- and N-terminal Shh peptides increased in bone marrow and peripheral blood mononuclear cells isolated from AML patients, and the plasma N-Shh secretion was greater. To further clarify the effect of IL-6 and resveratrol in Shh signaling, human AML HL-60 cells were tested. IL-6 upregulated Shh and Gli-1 expression and was accompanied by an increase of cell viability. Resveratrol significantly decreased CSC-related Shh expression, Gli-1 nuclear translocation, and cell viability in IL-6-treated HL-60 cells and had synergistic effect with Shh inhibitor cyclopamine on inhibiting cell growth. Conclusions. IL-6 stimulated the growth of AML cells through Shh signaling, and this effect might be blocked by resveratrol. Further investigations of Shh as a prognostic marker and resveratrol as a therapeutic drug target to CSCs in AML are surely warranted

Clinical Evaluation of Acupuncture as Treatment for Complications of Cerebrovascular Accidents: A Randomized, Sham-Controlled, Subject- and Assessor-Blind Trial

Background and Purpose. The effect of acupuncture as treatment for poststroke complications is questionable. We performed a randomized, sham-controlled double-blind study to investigate it. Methods. Patients with first-time acute stroke were randomized to receive 24 sessions of either real or sham acupuncture during an eight-week period. The primary outcome measure was change in National Institute of Health Stroke Scale (NIHSS) score. Secondary outcome measures included changes in Barthel Index (BI), Instrumental Activities of Daily Living (IADL), Hamilton Depression Rating Scale (HAM-D), and Visual Analogue Scale (VAS) for pain scores. Results. Of the 52 patients who were randomized to receive acupuncture (n=28) or placebo (n=24), 10 patients in the acupuncture group and 9 patients in the placebo group failed to complete the treatment. In total, 18 patients in the acupuncture group and 15 patients in the control group completed the treatment course. Reduction in pain was significantly greater in the acupuncture group than in the control group (p value = 0.04). There were no significant differences in the other measures between the two groups. Conclusions. Acupuncture provided more effective poststroke pain relief than sham acupuncture treatment. However, acupuncture had no better effect on neurological, functional, and psychological improvement

Tunable polarization-drived superior energy storage performance in PbZrO3 thin films

Antiferroelectric PbZrO3 (AFE PZO) films have great potential to be used as the energy storage dielectrics due to the unique electric field (E)-induced phase transition character. However, the phase transition process always accompanies a polarization (P) hysteresis effect that induces the large energy loss (Wloss) and lowers the breakdown strength (EBDS), leading to the inferior energy storage density (Wrec) as well as low efficiency. In this work, the synergistic strategies by doping smaller ions of Li+–Al3+ to substitute Pb2+ and lowering the annealing temperature (T) from 700 to 550 ℃ are proposed to change the microstructures and tune the polarization characters of PZO films, except to dramatically improve the energy storage performances. The prepared Pb(1−x)(Li0.5Al0.5)xZrO3 (P(1−x)(L0.5A0.5)xZO) films exhibit ferroelectric (FE)-like rather than AFE character once the doping content of Li+–Al3+ ions reaches 6 mol%, accompanying a significant improvement of Wrec of 49.09 J/cm3, but the energy storage efficiency (η) is only 47.94% due to the long-correlation of FE domains. Accordingly, the low-temperature annealing is carried out to reduce the crystalline degree and the P loss. P0.94(L0.5A0.5)0.06ZO films annealed at 550 ℃ deliver a linear-like polarization behavior rather than FE-like behavior annealed at 700 ℃, and the lowered remanent polarization (Pr) as well as improved EBDS (4814 kV/cm) results in the superior Wrec of 58.7 J/cm3 and efficiency of 79.16%, simultaneously possessing excellent frequency and temperature stability and good electric fatigue tolerance