Wave properties in asymmetric single-negative-base photonic crystals.

We theoretically study wave properties for one-dimensional defective asymmetric photonic crystals, air/(AB)MG(BA)N/air, air/(AQ)MG(QA)N/air, and air/(BQ)MG(QB)N/air, where A is a lossy epsilon-negative material, B is a lossy mu-negative material, G and Q are dielectrics with different refractive indexes, and M and N are stack numbers with M≠N. Special attention has been paid to their absorption spectra. It is found that at certain frequencies the absorption can exhibit unidirectional properties. Our calculated results show two kinds of unidirectional absorption peaks. One is a single absorption peak whose frequency depends on the thickness of defect layer G. For the other peaks, its frequency does not change when the defect layer's thickness changes. In addition, in the second kind of peaks, the peak numbers for forward and backward propagation are different, that is, there are (M-1) absorption peaks for forward propagation, while there are (N-1) absorption peaks for backward propagation. When the two kinds of unidirectional absorption peaks are merged, some new peaks appear, and both forward and backward propagation will have (M+N-1) absorption peaks.

White matter tract integrity of frontostriatal circuit in attention deficit hyperactivity disorder: association with attention performance and symptoms.

The frontostriatal circuit has been postulated to account for the core symptoms such as inattention in attention deficit/hyperactivity disorder (ADHD). This study investigated the white matter integrity of frontostriatal fiber tracts using diffusion spectrum imaging (DSI) tractography and its correlations with measures of multi-dimensional aspects of inattention based on psychiatric interview and attention tasks in 25 children with ADHD and 25 matched typically developing (TD) children. All the subjects were assessed with comprehensive psychiatric interviews and the Conner's Continuous Performance Test (CCPT). DSI data were acquired on a 3-Tesla MRI system. The frontostriatal fiber pathways were reconstructed by deterministic tractography, and generalized fractional anisotropy values were measured along individual targeted tracts to investigate alterations in microstructure integrity. Children with ADHD performed worse than TD children in the dimensions of focused attention, sustained attention, impulsivity, and vigilance of the CCPT, and showed impaired integrity in four bilateral frontostriatal tracts, namely the dorsolateral-caudate, medial prefrontal-caudate, orbitofrontal-caudate, and ventrolateral-caudate tracts, and in global white matter as well. The integrity of the left orbitofronto-caudate tract was associated with the symptom of inattention in children with ADHD, compatible with the attention deficit and motivational dysfunction theories in ADHD. The integrity of the frontostriatal tracts was associated with the attention performance only in TD children, suggestive of possible recruitment of tracts other than the frontostriatal tracts implicated in attention deficits in children with ADHD. In conclusion, our results demonstrate the functional involvement of the frontostriatal circuit with respect to clinical symptoms and attention performance.

Germ aversion is a risk factor for chronic low back pain and shoulder pain under the COVID-19 pandemic: an internet-based panel study.

The COVID-19 pandemic has increased germ aversion, an aversive affective response to a high likelihood of pathogen transmission. While psychological factors are associated with chronic pain, the relationship between germ aversion and chronic pain remains unexplored. This study aimed to examine the relationship between germ aversion and new-onset and prognosis of chronic pain using longitudinal data collected during the COVID-19 pandemic. We conducted web-based surveys of full-time workers at baseline and after three months. Data were collected on demographic characteristics, psychological factors, and chronic pain. Germ aversion was assessed using a modified Perceived Vulnerability to Disease scale. We analyzed responses from 1265 panelists who completed the survey twice. The prevalence of chronic low back pain (CLBP) and chronic neck and shoulder pain (CNSP) was associated with sex, short sleep duration, psychological distress, loneliness, and germ aversion. Stratified analyses showed that germ aversion was a risk factor for CLBP at three months in both individuals with and without CLBP at baseline, and for CNSP at three months in those with CNSP at baseline, even after adjustment for confounders. In conclusion, this preliminary study suggests that high germ aversion is a risk factor for CLBP and CNSP in young and middle-aged workers.

Comparative modeling of improved synthesis of energetic dinitrobenzofuroxan (DNBF) derivatives.

Quantum chemical theoretical computation was performed on gaseous molecular reaction systems to simulate parallel synthesis of energetic primary explosive precursor 4,6-dinitrobenzofuroxan (4,6-DNBF) and its isomeric derivatives. Related polarized continuum model (PCM) and Materials Studio (MS/forcite) energies were collected via kinetic rate and thermodynamic equilibrium analyses, enabling comparison of and suggestions as to suitable reaction conditions (reaction temperature, reagent concentration, mixed acid ratio) together with feasible pathways to obtain a high production yield of the research target. In summary, at a low reaction temperature of 278 K, 1.0 M 4-nitrobenzofuroxan (or 5,6-nitrobenzofuroxan) could be nitrated using concentrated nitric acid/sulfuric acid at a 1 to 2 volume ratio to efficiently and rapidly produce 4,6-dinitro-benzofuroxan (or 5,6-dinitrobenzofuroxan), in agreement with the experimental results reported in the literature. Graphical abstract.

Transcutaneous electric acupoint stimulation alleviates remifentanil-induced hyperalgesia in patients undergoing thyroidectomy: a randomized controlled trial.

BACKGROUND: In this prospective, randomized, double-blind study, we verified the hypothesis that TEAS can alleviate remifentanil-induced hyperalgesia in patients undergoing thyroidectomy. METHODS: 60 American Society of Anesthesiologists physical status (ASA) I-IIpatients, aged 18-60 year, scheduled for thyroidectomy were randomly allocated to TEAS or sham groups. TEAS consisted of 30 min of stimulation (6-9 mA, 2/10 Hz) on the Hegu (LI4) and Neiguan (PC6) before anesthesia. Anesthesia was maintained with sevoflurane adjusted to bispectral index (40-60) and target remifentanil 5.0 ng/ml. Mechanical pain thresholds were assessed using electronic von Frey. The primary outcome was mechanical pain thresholds. Secondary outcomes included postoperative pain scores, the time to first rescue analgesic, cumulative number of rescue analgesia, and side effects, including postoperative nausea and vomiting (PONV), dizziness and shivering in 24 h postoperatively. RESULTS: Baseline mechanical pain thresholds were similar between the groups. The analysis revealed the decrease in mechanical threshold was greater in the sham group than the TEAS group (P < 0.001). Postoperative pain scores and cumulative number of rescue analgesia were lower in the TEAS group (P < 0.05). In addition, TEAS group patients reduced the incidence of PONV and shivering. CONCLUSION: Preoperative TEAS can attenuate remifentanil-induced hyperalgesia in patients undergoing thyroidectomy.

Transcutaneous Electrical Acupoint Stimulation Improves the Postoperative Quality of Recovery and Analgesia after Gynecological Laparoscopic Surgery: A Randomized Controlled Trial.

Background. We conducted this prospective, randomized, double-blind, placebo-controlled study to evaluate the effects of transcutaneous electric acupoint stimulation (TEAS) on the quality of recovery (QoR) and postoperative analgesia after gynecological laparoscopic surgery. Methods. 74 American Society of Anesthesiologists physical status (ASA) I or II patients undergoing gynecological laparoscopic surgery were randomly allocated to TEAS or control groups. The primary outcome was the quality of recovery, which was assessed on the day before surgery and 24 h after surgery using a 40-item questionnaire. Secondary outcomes included postoperative pain scores, the incidence of postoperative nausea and vomiting (PONV), duration of postanesthesia care unit (PACU) stay, and patient's satisfaction. Results. The TEAS group had higher QoR scores than control group upon 24 h after surgery (177 versus 165; P < 0.001). Compared with the control group, postoperative pain scores and the cumulative number of opioids administered were lower in the TEAS group patients (P = 0.04). TEAS reduced the incidence of PONV and dizziness, as well as duration of PACU stay. Simultaneously, the patient's satisfaction scores were higher in the TEAS group (P = 0.002). Conclusion. Preoperative TEAS enhances QoR, improves postoperative analgesia and patient's satisfaction, alleviates postoperative side effects, and accelerates discharge after general anesthesia for gynecological laparoscopic surgery.