Joint control of Drosophila male courtship behavior by motion cues and activation of male-specific P1 neurons

Sexual behaviors in animals are governed by inputs from multiple external sensory modalities. However, how these inputs are integrated to jointly control animal behavior is still poorly understood. Whereas visual information alone is not sufficient to induce courtship behavior in Drosophila melanogaster males, when a subset of male-specific fruitless (fru)- and doublesex (dsx)-expressing neurons that respond to chemosensory cues (P1 neurons) were artificially activated via a temperature-sensitive cation channel (dTRPA1), males followed and extended their wing toward moving objects (even a moving piece of rubber band) intensively. When stationary, these objects were not courted. Our results indicate that motion input and activation of P1 neurons are individually necessary, and under our assay conditions, jointly sufficient to elicit early courtship behaviors, and provide insights into how courtship decisions are made via sensory integration.     

Hierarchical nanostructured conducting polymer hydrogel with high electrochemical activity

Conducting polymer hydrogels represent a unique class of materials that synergizes the advantageous features of hydrogels and organic conductors and have been used in many applications such as bioelectronics and energy storage devices. They are often synthesized by polymerizing conductive polymer monomer within a nonconducting hydrogel matrix, resulting in deterioration of their electrical properties. Here, we report a scalable and versatile synthesis of multifunctional polyaniline (PAni) hydrogel with excellent electronic conductivity and electrochemical properties. With high surface area and three-dimensional porous nanostructures, the PAni hydrogels demonstrated potential as high-performance supercapacitor electrodes with high specific capacitance (~480 F·g(-1)), unprecedented rate capability, and cycling stability (~83% capacitance retention after 10,000 cycles). The PAni hydrogels can also function as the active component of glucose oxidase sensors with fast response time (~0.3 s) and superior sensitivity (~16.7 μA · mM(-1)). The scalable synthesis and excellent electrode performance of the PAni hydrogel make it an attractive candidate for bioelectronics and future-generation energy storage electrodes.     

Crucial role of copper in detection of metal-coordinating odorants

Odorant receptors (ORs) in olfactory sensory neurons (OSNs) mediate detection of volatile odorants. Divalent sulfur compounds, such as thiols and thioethers, are extremely potent odorants. We identify a mouse OR, MOR244-3, robustly responding to (methylthio)methanethiol (MeSCH(2)SH; MTMT) in heterologous cells. Found specifically in male mouse urine, strong-smelling MTMT [human threshold 100 parts per billion (ppb)] is a semiochemical that attracts female mice. Nonadjacent thiol and thioether groups in MTMT suggest involvement of a chelated metal complex in MOR244-3 activation. Metal ion involvement in thiol-OR interactions was previously proposed, but whether these ions change thiol-mediated OR activation remained unknown. We show that copper ion among all metal ions tested is required for robust activation of MOR244-3 toward ppb levels of MTMT, structurally related sulfur compounds, and other metal-coordinating odorants (e.g., strong-smelling trans-cyclooctene) among >125 compounds tested. Copper chelator (tetraethylenepentamine, TEPA) addition abolishes the response of MOR244-3 to MTMT. Histidine 105, located in the third transmembrane domain near the extracellular side, is proposed to serve as a copper-coordinating residue mediating interaction with the MTMT-copper complex. Electrophysiological recordings of the OSNs in the septal organ, abundantly expressing MOR244-3, revealed neurons responding to MTMT. Addition of copper ion and chelator TEPA respectively enhanced and reduced the response of some MTMT-responding neurons, demonstrating the physiological relevance of copper ion in olfaction. In a behavioral context, an olfactory discrimination assay showed that mice injected with TEPA failed to discriminate MTMT. This report establishes the role of metal ions in mammalian odor detection by ORs.     

Net -1 frameshifting on a noncanonical sequence in a herpes simplex virus drug-resistant mutant is stimulated by nonstop mRNA

Ribosomal frameshifting entails slippage of the translational machinery during elongation. Frameshifting permits expression of more than one polypeptide from an otherwise monocistronic mRNA, and can restore expression of polypeptides in the face of frameshift mutations. A common mutation conferring acyclovir resistance in patients with herpes simplex virus disease deletes one cytosine from a run of six cytosines (C-chord) in the viral thymidine kinase (tk) gene. However, this mutation does not abolish TK activity, which is important for pathogenicity. To investigate how this mutant retains TK activity, we engineered and analyzed viruses expressing epitope-tagged TK. We found that the mutant's TK activity can be accounted for by low levels of full-length TK polypeptide produced by net -1 frameshifting during translation. The efficiency of frameshifting was relatively high, 3-5%, as the polypeptide from the reading frame generated by the deletion, which lacks stop codons (nonstop), was poorly expressed mainly because of inefficient protein synthesis. Stop codons introduced into this reading frame greatly increased its expression, but greatly decreased the level of full-length TK, indicating that frameshifting is strongly stimulated by a new mechanism, nonstop mRNA, which we hypothesize involves stalling of ribosomes on the polyA tail. Mutational studies indicated that frameshifting occurs on or near the C-chord, a region lacking a canonical slippery sequence. Nonstop stimulation of frameshifting also occurred when the C-chord was replaced with a canonical slippery sequence from HIV. This mechanism thus permits biologically and clinically relevant TK synthesis, and may occur more generally.     

From the Cover: Quantum teleportation between remote atomic-ensemble quantum memories

Quantum teleportation and quantum memory are two crucial elements for large-scale quantum networks. With the help of prior distributed entanglement as a “quantum channel,” quantum teleportation provides an intriguing means to faithfully transfer quantum states among distant locations without actual transmission of the physical carriers [Bennett CH, et al. (1993) Phys Rev Lett 70(13):1895–1899]. Quantum memory enables controlled storage and retrieval of fast-flying photonic quantum bits with stationary matter systems, which is essential to achieve the scalability required for large-scale quantum networks. Combining these two capabilities, here we realize quantum teleportation between two remote atomic-ensemble quantum memory nodes, each composed of ∼10⁸ rubidium atoms and connected by a 150-m optical fiber. The spin wave state of one atomic ensemble is mapped to a propagating photon and subjected to Bell state measurements with another single photon that is entangled with the spin wave state of the other ensemble. Two-photon detection events herald the success of teleportation with an average fidelity of 88(7)%. Besides its fundamental interest as a teleportation between two remote macroscopic objects, our technique may be useful for quantum information transfer between different nodes in quantum networks and distributed quantum computing.     

Outcomes of preoperative Angiotensin-converting enzyme inhibitor therapy in patients undergoing isolated coronary artery bypass grafting

The association between preoperative use of angiotensin-converting enzyme (ACE) inhibitors and outcomes after coronary artery bypass grafting (CABG) remain controversial. Our aim was to study in-hospital outcomes after isolated CABG in patients on preoperative ACE inhibitors. A retrospective analysis of 8,889 patients who underwent isolated CABG from 2000 through 2011 was conducted. The primary outcome of interest was the incidence of major adverse events (MAEs) defined as a composite of mortality, postoperative renal dysfunction, myocardial infarction, stroke, and atrial fibrillation during index hospitalization. The secondary outcome was the incidence of individual outcomes included in MAEs. Logistic regression analyses were performed. Of 8,889 patients, 3,983 (45%) were on preoperative ACE inhibitors and 4,906 (55%) were not. Overall incidence of MAEs was 38.1% (n = 1,518) in the ACE inhibitor group compared to 33.6% (n = 1,649) in the no-ACE inhibitor group. Preoperative use of ACE inhibitors was independently associated with MAEs (odds ratio 1.13, 95% confidence interval 1.03 to 1.24), most of which was driven by a statistically significant increase in postoperative renal dysfunction (odds ratio 1.18, 95% confidence interval 1.03 to 1.36) and atrial fibrillation (odds ratio 1.15, 95% confidence interval 1.05 to 1.27). In-hospital mortality, postoperative myocardial infarction, and stroke were not significantly associated with preoperative ACE inhibitor use. Analyses performed after excluding patients with low ejection fractions yielded similar results. In conclusion, preoperative ACE inhibitor use was associated with an increased risk of MAEs after CABG, in particular postoperative renal dysfunction and atrial fibrillation.     

牙龈卟啉单胞菌PG0839基因突变株的构建

目的构建牙龈卟啉单胞菌毒力岛基因PG0839突变菌株,为研究PG0839基因功能提供实验基础。方法扩增1 584 bp PG0839基因片段,对聚合酶链反应（PCR）产物和pUC19载体进行BamH Ⅰ和EcoRⅠ双酶切,连接酶切产物得到质粒pPG0839-1。将2 101 bp erm基因产物插入到pPG0839-1中PG0839基因的EcoRⅤ位点,构建质粒pPG0839-2,作为电穿孔的供体质粒。电穿孔转化于受体菌牙龈卟啉单胞菌W83菌株,红霉素抗性培养基筛选阳性克隆,命名为PG0839基因突变菌株。结果运用插入失活方法构建PG0839基因突变菌株,进而通过酶切、测序、PR和反转录PCR对PG0839基因突变菌株进行验证,证实PG0839基因突变菌株构建成功。结论本实验成功构建PG0839基因突变菌株。     

口腔局部麻醉的并发症及其防治

口腔局部麻醉是口腔疾病诊治过程中经常应用的技术之一,其并发症及不良反应的发生率为4．5％－13％,其中大部分不良反应是可逆的、一过性的,但是不能排除威胁生命的可能。口腔局部麻醉的并发症分为局部并发症和全身并发症2大类,具体类型较多,在临床处理中需要注意的问题亦较多;因此,对于口腔医师来说,除了掌握口腔局部麻醉理论和技术之外,如何正确预防和处理口腔局部麻醉的并发症,也是一项必备的临床技能。本文着重于临床常见的局部麻醉并发症,对其防治原则进行了探讨和论述。