创新人才培养目标下仪器分析“教研赛”教学模式研究

依照创新人才培养目标,针对传统仪器分析教学中存在的弊端,以竞赛为依托,将科研前沿引入课堂,以线上教学为纽带,开展“教研赛”融合式教学模式改革探索。该教学模式着重培养学生的创新意识、创新思维、创新能力,以及综合分析问题、解决问题的能力;同时,该教学模式也促进理论与实验教学的衔接,形成“虚实结合、理实一体化”的教学体系。

Risk factors of intra-abdominal bacterial infection after liver transplantation in patients with hepatocellular carcinoma

Objective： To explore the risk factors of intra-abdominal bacterial infection （IAI） after liver transplantation （LT） in patients with hepatocellular carcinoma （HCC）. Methods： A series of 82 HCC patients who received LT surgeries in our department between March 2004 and April 2010 was recruited in this study. Then we collected and analyzed the clinical data retrospectively. Statistical analysis system （SPSS） software was adopted to perform statistical analysis. Chi-square test, t-test and Wilcoxon rank sum test were used to analyze the clinical data and compute the significance of the incidences of early-stage IAI after LT for HCC patients. Binary logistic regression was performed to screen out the risk factors, and multiple logistic regression analyses were performed to compute the independent risk factors. Results： A series of 13 patients （13/82, 15.9%） had postoperative IAI. The independent risk factors of postoperative intra-abdominal bacterial infections after LT for HCC patients were preoperative anemia [Hemoglobin （HGB） 〈90 g/L] and postoperative abdominal hemorrhage （72 hours 〉400 mL）, with the odds ratios at 8.121 （95% CI, 1.417 to 46.550, P=0.019） and 5.911 （95% CI, 1.112 to 31.432, P=0.037）. Conclusions： Postoperative IAI after LT in patients with HCC was a common complication. Preoperative moderate to severe anemia, as well as postoperative intra-abdominal hemorrhage more than 400 mL within the first 72 hours might independently indicate high risk of IAI for these patients.

“Wrapping the gastroduodenal artery stump” during pancreatoduodenectomy reduced the stump hemorrhage incidence after operation

Objective： After pancreaticoduodenectomy （PD）, the postoperative gastroduodenal artery stump （GDAS） hemorrhage is one of the most serious complications. The purpose of this study is to determine whether wrapping the GDAS during PD could decrease the postoperative GDAS hemorrhage incidence. Methods： A retrospective review involving 280 patients who underwent PD from 2005 to 2012 was performed. Wrapping the GDAS during PD was defined as ＂Wrapping the GDAS using the teres hepatis ligamentum during PD＂. A total of 140 patients accepted the ＂wrapping＂ procedure （wrapping group）. The other 140 patients didn＇t apply the procedure （non-wrapping group）. Age, sex, preoperative data, estimated intraoperative blood loss, postoperative complications, pathologic parameters and hospitalization time were compared between two groups. ResultsI There were no significant differences in patient characteristics between two groups. After wrapping, the incidence of postoperative GDAS bleeding decreased significantly （1/140 vs. 9/140, P=0.01）. The rates of the other complications （such as intra-abdominal infection pancreatic fistula, billiary fistula, gastrointestinal bleeding, et aL） showed no significant differences. Conclusions： Wrapping the GDAS during PD significantly reduced the postoperative GDAS hemorrhage incidence. And the ＂wrapping＂ had no obvious influence on other complications.

High sideband suppression silicon single sideband modulator integrated with a radio frequency branch line coupler

We demonstrate a single-chip silicon optical single sideband (OSSB) modulator composed of a radio frequenc(RF) branch line coupler (BLC) and a silicon dual-parallel Mach–Zehnder modulator (DP-MZM).A co-design between the BLC and the DP-MZM is implemented to improve the sideband suppression ratio (SSR).The modu lator has a modulation efficiency of V_(π)L_(π)~1.75 V·cm and a 3 dB electro-optical (EO) bandwidth of 48.7 GHz The BLC can generate a pair of RF signals with equal amplitudes and orthogonal phases at the optimal frequenc of 21 GHz.We prove through theoretical calculation and experiment that,although the BLC’s performance in terms of power balance and phase orthogonality deteriorates in a wider frequency range,high SSRs can be realized by adjusting relevant bias phases of the DP-MZM.With this technique,the undesired sidebands are completel suppressed below the noise floor in the frequency range from 15 GHz to 30 GHz when the chip operates in the ful carrier OSSB (FC-OSSB) mode.In addition,an SSR>35 dB and an carrier suppression ratio (CSR)>42 dB ar demonstrated at 21 GHz in the suppressed carrier OSSB (SC-OSSB) mode.

How Microbes Shape Their Communities? A Microbial Community Model Based on Functional Genes

Exploring the mechanisms of maintaining microbial community structure is important to understand biofilm development or microbiota dysbiosis. In this paper, we propose a functional gene-based composition prediction(FCP) model to predict the population structure composition within a microbial community. The model predicts the community composition well in both a low-complexity community as acid mine drainage(AMD) microbiota, and a complex community as human gut microbiota. Furthermore, we define community structure shaping(CSS) genes as functional genes crucial for shaping the microbial community. We have identified CSS genes in AMD and human gut microbiota samples with FCP model and find that CSS genes change with the conditions. Compared to essential genes for microbes, CSS genes are significantly enriched in the genes involved in mobile genetic elements, cell motility, and defense mechanisms, indicating that the functions of CSS genes are focused on communication and strategies in response to the environment factors. We further find that it is the minority, rather than the majority, which contributes to maintaining community structure. Compared to health control samples, we find that some functional genes associated with metabolism of amino acids, nucleotides, and lipopolysaccharide are more likely to be CSS genes in the disease group. CSS genes may help us to understand critical cellular processes and be useful in seeking addable gene circuitries to maintain artificial self-sustainable communities. Our study suggests that functional genes are important to the assembly of microbial communities.

Flexible Three-Dimensional Graphene Hydrogels with Superior Conductivity and Excellent Electrochemical Performance for Supercapacitor Electrodes

Three-dimensional porous graphene hydrogels have been prepared by a green and facile but very efficient ap- proach using glucose as an assistant. Based on a one-step hydrothermal reaction with optimal experimental condi- tions such as the reaction time and temperature, the graphene hydrogels exhibit a superior electrical conductivity （95.3 S/m） and can be used as supercapacitor electrode without any binder or conducting additives but showing a high specific capacitance of 384.6 F/g at a current density of 1 A/g. The results show that addition of glucose can not only greatly decrease the reaction temperature but also shorten the reaction time. The superior performance of the three-dimensional porous graphene hydrogels as electrode for supercapacitor suggests its promising potentials in the field of energy storage devices.

Improved performance and air stability of perovskite solar cells based on low-cost organic hole-transporting material X60 by incorporating its dicationic salt

The development of an efficient, stable, and low-cost hole-transporting material (HTM) is of great significance for perovskite solar cells (PSCs) from future commercialization point of view. Herein, we specifically synthesize a dicationic salt of X60 termed X60(TFSI)2, and adopt it as an effective and stable "doping" agent to replace the previously used lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) for the low-cost organic HTM X60 in PSCs. The incorporation of this dicationic salt significantly increases the hole conductivity of X60 by two orders of magnitude from 10-6 to 10-4 S cm-1. The dramatic enhancement of the conductivity leads to an impressive power conversion efficiency (PCE) of 19.0% measured at 1 sun illumination (100 mW cm-2, AM 1.5 G), which is comparable to that of the device doped with LiTFSI (19.3%) under an identical condition. More strikingly, by replacing LiTFSI, the PSC devices incorporating X60(TFSI)2 also show an excellent long-term durability under ambient atmosphere for 30 days, mainly due to the hydrophobic nature of the X60(TFSI)2 doped HTM layer,which can effectively prevent the moisture destroying the perovskite layer. The present work paves the way for the development of highly efficient, stable, and low-cost HTM for potential commercialization of PSCs.

Variant selection in stationary shoulder friction stir welded Ti-6Al-4V alloy

Stationary shoulder friction stir welding of Ti-6Al-4V of 7 mm thickness was conducted with varying welding speeds and rotation speeds. Variant selection analysis was carried out based on the inherited α phase texture and the reconstructed 13 phase texture. The weld surfaces became significantly smoother with increasing welding speed and decreasing rotation speed. Heat input decreased greatly with increased welding speed and it decreased slightly with decreased rotation speed. The orientation relationship between the prior 13 grains was measured based on the reconstructed electron backscattered diffraction （EBSD） data. Weak Variant selection has occurred in all the welds because most of the prior 13 grains did not share { 110} poles. Strong links between crystal orientation of the prior 13 grains and hardness have been found.

Efficient perovskite solar cells employing a solution-processable copper phthalocyanine as a hole-transporting material

The development of alternative low-cost and high-performing hole-transporting materials(HTMs) is of great significance for the potential large-scale application of perovskite solar cells(PSCs) in the future.Here,a facilely synthesized solution-processable copper tetra-(2,4-dimethyl-3-pentoxy) phthalocyanine(CuPc-DMP) via only two simple steps,has been incorporated as a hole-transporting material(HTM) in mesoscopic perovskite solar cells(PSCs).The optimized devices based on such a HTM afford a very competitive power conversion efficiency(PCE) of up to 17.1%measured at 100 mW cm^(-2) AM 1.5G irradiation,which is on par with that of the well-known 2,2',7,7'-tetrakis(N'N'-di-p-methoxyphenylamine)-9,9'-spirobifluorene(spiro-OMeTAD)(16.7%) under equivalent conditions.This is,to the best of our knowledge,the highest value reported so far for metal organic complex-based HTMs in PSCs.The advantages of this HTM observed,such as facile synthetic procedure,superior hole transport characteristic,high photovoltaic performance together with the feasibility of tailoring the molecular structure would make solution-processable copper phthalocyanines as a class of promising HTM that can be further explored in PSCs.The present finding highlights the potential application of solution processed metal organic complexes as HTMs for cost-effective and high-performing PSCs.

LANXESS Greater China Sales Grow 7.8% for Q2

LANXESS Greater China sales increased by7.8% to EUR 167.5 million for the secondquarter of 2009 compared to the same periodof 2008. Adjusted for exchange-rate effectsand divested or newly integrated businesses,it receded slightly by 3.6%. In comparison tothe weak first quarter of 2009, sales almostdoubled from EUR 84.8 million.