Current rectification by asymmetric molecules: An ab initio study

We study current rectification effect in an asymmetric molecule HOOC-C$_6$H$_4$-(CH$_2$)$_n$ sandwiched between two Aluminum electrodes using an {\sl ab initio} nonequilibrium Green function method. The conductance of the system decreases exponentially with the increasing number $n$ of CH$_2$. The phenomenon of current rectification is observed such that a very small current appears at negative bias and a sharp negative differential resistance at a critical positive bias when $n\ge 2$. The rectification effect arises from the asymmetric structure of the molecule and the molecule-electrode couplings. A significant rectification ratio of $\sim$38 can be achieved when $n=5$.Comment: to appear in J. Chem. Phy

Implementation and effect of daily review method in management of cardiovascular surgical intensive care unit

目的  探讨日点评分析法对心血管重症监护室内病人护理质量的提高及对护士日常工作规范的重要性。方法  每日医护书面晨交班后，利用30min时间，由护士长主持，首先，根据医护晨交班的内容对于监护室内的病人基本病情请每位责任护士对自己所管的病人病情进行描述，责任组长补充，尤其对现存或潜在的护理问题重点指出。其次，根据病人的诊断、手术后的护理重点、现存或潜在的护理问题并结合国内外护理动态向当天值班的护士讲解。最后，根据病人术后恢复情况及病情向责任护士交待每位病人应观察的重点；向监护室的行政组长交待督导的重点、存在的安全隐患等。结果  医护满意度、 患者满意度、核心护理质量指标与去年同期相比均有较大幅度的提高。压疮、意外拔管、坠床等不良事件发生率均为零。结论  日点评分析法启用以来调动了护士的积极性。对于一些理论知识欠缺或临床经验较少的护士是一个很好的学习机会。使护士能够有重点的观察处理病人。并对当天的工作有非常周密的安排。Objective: To explore the effect of daily review method on normalization of nurses’ daily work as well as the improvement of the quality of nursing in the cardiovascular intensive patients at ICU. Methods: The head nurse hosts the daily review, to fully use of 30 minutes, after handover of medical records in the morning. First of all, every nurse is required to describe the basic conditions of the patients in ICU according to the contents of medical records, the leader added, especially for existing or potential problems. Second, explain patient’s diagnosis, the key points of nursing after operation, the existing or potential nursing problems combined with the domestic and international nursing trends to the nurse on duty. Finally, teach the nurse in charge the priority during observation according to the patient’s postoperative recovery and the condition of the patient, and explain to the chief executive of ICU about the focus of monitor, the existence of security risks. Results: Health care satisfaction, patient satisfaction, core quality of care and quality indicators were significantly improved compared with the previous year. The incidence of adverse events such as pressure ulcer, accidental extubation and falling bed were all zero. Conclusion: Daily review analysis method could mobilize the enthusiasm of nurses, provides a good learning opportunity for nurses with a lack of theoretical knowledge and clinical experience. It enables nurses to mask focused observation and treatment of patients. And it facilitates a very thorough arrangement of the nurses.

Experimental demonstration of tripartite entanglement and controlled dense coding for continuous variables

A tripartite entangled state of bright optical field is experimentally produced using an Einstein-Podolsky-Rosen entangled state for continuous variables and linear optics. The controlled dense coding among a sender, a receiver and a controller is demonstrated by exploiting the tripartite entanglement. The obtained three-mode position correlation and relative momentum correlation between the sender and the receiver and thus the improvements of the measured signal to noise ratios of amplitude and phase signals with respect to the shot noise limit are 3.28dB and 3.18dB respectively. If the mean photon number $\bar{n}$ equals 11 the channel capacity can be controllably inverted between 2.91 and 3.14. When $\bar{n}$ is larger than 1.0 and 10.52 the channel capacities of the controlled dense coding exceed the ideal single channel capacities of coherent and squeezed state light communication.Comment: 8 pages, 4 figure

Evaluation of Performance of Different Methods in Detecting Abrupt Climate Changes

We compared and evaluated the performance of five methods for detecting abrupt climate changes using a time series with artificially generated abrupt characteristics. Next, we analyzed these methods using annual mean surface air temperature records from the Shenyang meteorological station. Our results show that the moving t-test (MTT), Yamamoto (YAMA), and LePage (LP) methods can correctly and effectively detect abrupt changes in means, trends, and dynamic structure; however, they cannot detect changes in variability. We note that the sample size of the subseries used in these tests can affect their results. When the sample size of the subseries ranges from one-quarter to three-quarters of the jump scale, these methods can effectively detect abrupt changes; they perform best when the sample size is one-half of the jump scale. The Cramer method can detect abrupt changes in the mean and trend of a series but not changes in variability or dynamic structure. Finally, we found that the Mann-Kendall test could not detect any type of abrupt change. We found no difference in the results of any of the methods following removal of the mean, creation of an anomaly series, or normalization. However, detrending and study period selection affected the results of the Cramer and Mann-Kendall methods; in the latter case, they could lead to a completely different result

The juxtamembrane and carboxy-terminal domains of Arabidopsis PRK2 are critical for ROP-induced growth in pollen tubes.

Polarized growth of pollen tubes is a critical step for successful reproduction in angiosperms and is controlled by ROP GTPases. Spatiotemporal activation of ROP (Rho GTPases of plants) necessitates a complex and sophisticated regulatory system, in which guanine nucleotide exchange factors (RopGEFs) are key components. It was previously shown that a leucine-rich repeat receptor-like kinase, Arabidopsis pollen receptor kinase 2 (AtPRK2), interacted with RopGEF12 for its membrane recruitment. However, the mechanisms underlying AtPRK2-mediated ROP activation in vivo are yet to be defined. It is reported here that over-expression of AtPRK2 induced tube bulging that was accompanied by the ectopic localization of ROP-GTP and the ectopic distribution of actin microfilaments. Tube depolarization was also induced by a potentially kinase-dead mutant, AtPRK2K366R, suggesting that the over-expression effect of AtPRK2 did not require its kinase activity. By contrast, deletions of non-catalytic domains in AtPRK2, i.e. the juxtamembrane (JM) and carboxy-terminal (CT) domains, abolished its ability to affect tube polarization. Notably, AtPRK2K366R retained the ability to interact with RopGEF12, whereas AtPRK2 truncations of these non-catalytic domains did not. Lastly, it has been shown that the JM and CT domains of AtPRK2 were not only critical for its interaction with RopGEF12 but also critical for its distribution at the plasma membrane. These results thus provide further insight into pollen receptor kinase-mediated ROP activation during pollen tube growth

Maximally localized states and quantum corrections of black hole thermodynamics in the framework of a new generalized uncertainty principle

As a generalized uncertainty principle (GUP) leads to the effects of the minimal length of the order of the Planck scale and UV/IR mixing, some significant physical concepts and quantities are modified or corrected correspondingly. On the one hand, we derive the maximally localized states --- the physical states displaying the minimal length uncertainty associated with a new GUP proposed in our previous work. On the other hand, in the framework of this new GUP we calculate quantum corrections to the thermodynamic quantities of the Schwardzschild black hole, such as the Hawking temperature, the entropy, and the heat capacity, and give a remnant mass of the black hole at the end of the evaporation process. Moreover, we compare our results with that obtained in the frameworks of several other GUPs. In particular, we observe a significant difference between the situations with and without the consideration of the UV/IR mixing effect in the quantum corrections to the evaporation rate and the decay time. That is, the decay time can greatly be prolonged in the former case, which implies that the quantum correction from the UV/IR mixing effect may give rise to a radical rather than a tiny influence to the Hawking radiation.Comment: 27 pages, 10 figures, 4 tables; v2: 30 pages, sections 3-6 substantially revised but conclusions unchanged; v3: 27 pages, clarifications added; v4: 29 pages, clarifications and references added, final version to appear in Advances in High Energy Physic