2-(1H-Pyrrolo­[2,3-b]pyridin-2-yl)pyridine

In the title compound, C12H9N3, the dihedral angle between the pyridine and aza­indole rings is 6.20 (2)°. In the crystal, pairs of N—H⋯N hydrogen bonds link mol­ecules into inversion dimers

3,4-Dinitro-2,5-bis­[4-(trifluoro­meth­yl)phen­yl]thio­phene

The title compound, C18H8F6N2O4S, is a precursor for the production of low-band-gap conjugated polymers. In the crystal structure, the dihedral angles between the thio­phene and benzene rings are 35.90 (8) and 61.94 (8)°, and that between the two benzene rings is 40.18 (8)°. The two nitro groups are twisted with respect to the thio­phene ring, the dihedral angles being 53.66 (10) and 31.63 (10)°. Weak inter­molecular C—H⋯O hydrogen bonding helps to stabilize the crystal structure

[4-(1-Benzofuran-2-yl)phen­yl]diphenyl­amine

The asymmetric unit of the title compound, C26H19NO, contains two mol­ecules. The dihedral angles between the benzofuran and benzene rings are 5.09 (8), 59.02 (8) and 67.74 (8)° in one mol­ecule and 18.70 (8), 52.78 (8) and 41.74 (8)° in the other. Weak inter­molecular C—H⋯π inter­actions help to stabilize the molecular structure

Entanglement, subsystem particle numbers and topology in free fermion systems

We study the relationship between bipartite entanglement, subsystem particle number and topology in a half-filled free fermion system. It is proposed that the spin-projected particle numbers can distinguish the quantum spin Hall state from other states, and can be used to establish a new topological index for the system. Furthermore, we apply the new topological invariant to a disordered system and show that a topological phase transition occurs when the disorder strength is increased beyond a critical value. It is also shown that the subsystem particle number fluctuation displays behavior very similar to that of the entanglement entropy. This provides a lower-bound estimation for the entanglement entropy, which can be utilized to obtain an estimate of the entanglement entropy experimentally.Comment: 14 pages, 6 figure

Effects of Electroacupuncture on Benign Prostate Hyperplasia Patients with Lower Urinary Tract Symptoms: A Single-Blinded, Randomized Controlled Trial

We tested the effect of electroacupuncture (EA) on lower urinary tract symptoms (LUTS) in benign prostatic hyperplasia (BPH) patients. A total of 42 BPH patients with LUTS were randomly assigned to either the EA group (EG), received 2 Hz EA for 20 min twice/week for a total of twelve treatments, or a sham EA group (CG), received sham EA. The increase of voiding volume, average flow rate, and maximal flow rate in the EG were 32.2 ± 104.4 mL, 1.2 ± 1.6 mL/sec, and 2.3 ± 3.7 mL/sec, respectively, from baseline value (before EA) using the measurement of an uroflowmetry. These increases were greater than −37.9 ± 120.4, −0.22 ± 2.7, and −0.3 ± 4.3, respectively, in the CG (P = .038, .026, and .030, resp.). The changes of prostate special antigen and international prostatic symptom score were not significantly different between two groups (P = .573, .175, resp.), suggesting the clinical improvement of 2 Hz EA was quite limited to the LUTS of patients with BPH

Online Multicast Traffic Engineering for Software-Defined Networks

Previous research on SDN traffic engineering mostly focuses on static traffic, whereas dynamic traffic, though more practical, has drawn much less attention. Especially, online SDN multicast that supports IETF dynamic group membership (i.e., any user can join or leave at any time) has not been explored. Different from traditional shortest-path trees (SPT) and graph theoretical Steiner trees (ST), which concentrate on routing one tree at any instant, online SDN multicast traffic engineering is more challenging because it needs to support dynamic group membership and optimize a sequence of correlated trees without the knowledge of future join and leave, whereas the scalability of SDN due to limited TCAM is also crucial. In this paper, therefore, we formulate a new optimization problem, named Online Branch-aware Steiner Tree (OBST), to jointly consider the bandwidth consumption, SDN multicast scalability, and rerouting overhead. We prove that OBST is NP-hard and does not have a $|D_{max}|^{1-\epsilon}$-competitive algorithm for any $\epsilon >0$, where $|D_{max}|$ is the largest group size at any time. We design a $|D_{max}|$-competitive algorithm equipped with the notion of the budget, the deposit, and Reference Tree to achieve the tightest bound. The simulations and implementation on real SDNs with YouTube traffic manifest that the total cost can be reduced by at least 25% compared with SPT and ST, and the computation time is small for massive SDN.Comment: Full version (accepted by INFOCOM 2018