Nonlocal Effects of Low-Energy Excitations in Quantum-Spin-Liquid Candidate Cu_(3)Zn(OH)_(6)FBr

We systematically study the low-temperature specific heats for the two-dimensional kagome antiferromagnet,Cu_(3)Zn(OH)_(6)FBr.The specific heat exhibits a T1.7 dependence at low temperatures and a shoulder-like feature above it.We construct a microscopic lattice model of Z_(2) quantum spin liquid and perform large-scale quantum Monte Carlo simulations to show that the above behaviors come from the contributions from gapped anyons and magnetic impurities.Surprisingly,we find the entropy associated with the shoulder decreases quickly with grain size d,although the system is paramagnetic to the lowest temperature.While this can be simply explained by a core-shell picture in that the contribution from the interior state disappears near the surface,the 5.9-nm shell width precludes any trivial explanations.Such a large length scale signifies the coherence length of the nonlocality of the quantum entangled excitations in quantum spin liquid candidate,similar to Pippard’s coherence length in superconductors.Our approach therefore offers a new experimental probe of the intangible quantum state of matter with topological order.

Effect of preoperative neoadjuvant chemotherapy on the expression of malignant molecules in colon cancer tissue and the degree of trauma caused by radical operation

Objective:To study the effect of preoperative neoadjuvant chemotherapy on the expression of malignant molecules in colon cancer tissue and the degree of trauma caused by radical operation.Methods: Patients who were diagnosed with colon cancer in Fengrun People's Hospital between March 2014 and February 2017 were selected and randomly divided into the XELOX group who accepted XELOX neoadjuvant chemotherapy combined with radical operation for colon cancer and the control group who accepted radical operation for colon cancer alone. Surgically removed colon cancer tissue was collected to test the expression of proliferation, apoptosis and invasion genes, and serum was collected to detect the contents of liver and kidney function indicators as well as inflammatory factors.Results: Rac1, PLD2, CHD1L, Snail, Vimentin and N-cadherin mRNA expression levels in surgically removed colon cancer lesions of XELOX group were significantly lower than those of control group while MS4A12 and ASPP2 mRNA expression levels were significantly higher than those of control group;serum ALT, AST,β2-MG, Cys-C, sICAM-1, sVCAM-1, sTM and sE-selectin contents were not significantly different between the two groups of patients 1 day and 3 days after surgery.Conclusion: Preoperative neoadjuvant chemotherapy can inhibit the proliferation, apoptosis and invasion gene expression in colon cancer tissues without increasing the trauma of operation.

Tunable patterning of microscale particles using a surface acoustic wave device with slanted-finger interdigital transducers

Polymer-based materials with patterned functional particles have been used to develop smart devices with multiple functionalities.This paper presents a novel method to pattern microscale particles into biocompatible polyethylene glycol diacrylate(PEGDA)fluid through a designed surface acoustic wave(SAW)device with slanted-finger interdigital transducers(SFITs).By applying signals of different frequencies,the SFITs can excite SAWs with various wavelengths to pattern the microscale particles.The structural design and working principle of the SAW device with SFITs are firstly presented.To investigate the generation of standing SAWs and pressure field distributions of the SAW device with SFITs,a numerical model was developed.Simulation results showed that different strip-shape patterned pressure fields can be generated,and the period and width of adjacent strips can be adjusted by changing the frequencies of the excitation signals.Experiments were performed to verify that the microscale particles in the PEGDA solution can be successfully patterned into strip-shape patterns with various positions,periods,and widths.The results obtained in this study demonstrate that the developed method of using an SAW device with SFITs can be used for tunable patterning of microscale particles in solutions,and shows great potential for biomedical and microfluidic applications.