Dissolved organic carbon concentrations, amino sugar concentrations and highly significantly correlating FT-ICR mass peak magnitudes obtained from solid phase extracted marine dissolved organic matter during POLARSTERN cruise ANT-XXV/1

Dissolved organic matter (DOM) was extracted with solid phase extraction (SPE) from 137 water samples from different climate zones and different depths along an Eastern Atlantic Ocean transect. The extracts were analyzed with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) with electrospray ionization (ESI). D14C analyses were performed on subsamples of the SPE-DOM. In addition, the amount of dissolved organic carbon was determined for all water and SPE-DOM samples as well as the yield of amino sugars for selected samples. Linear correlations were observed between the magnitudes of 43% of the FT-ICR mass peaks and the extract D14C values. Decreasing SPE-DOM D14C values went along with a shift in the molecular composition to higher average masses (m/z) and lower hydrogen/carbon (H/C) ratios. The correlation was used to model the SPE-DOM D14C distribution for all 137 samples. Based on single mass peaks a degradation index was developed to compare the degradation state of marine SPE-DOM samples analyzed with FT-ICR MS. A correlation between D14C, degradation index, DOC values and amino sugar yield supports that SPE-DOM analyzed with FT-ICR MS reflects trends of bulk DOM. A relative mass peak magnitude ratio was used to compare aged SPE-DOM and fresh SPE-DOM regarding single mass peaks. The magnitude ratios show a continuum of different reactivities for the single compounds. Only few of the compounds present in the FT-ICR mass spectra are expected to be highly degraded in the oldest water masses of the Pacific Ocean. All other compounds should persist partly thermohaline circulation. Prokaryotic (bacterial) production, transformation and accumulation of this very stable DOM occurs probably primarily in the upper ocean. This DOM is an important contribution to very old DOM, showing that production and degradation are dynamic processes.

ICR water utility database system users' guide /

"EPA 814/B-96-004."

Future directions in course quality assurance

The Course Quality Assurance System at Queensland University of Technology (QUT) has as its centrepiece an exemplar of data visualisation known as the Individual Course Report (ICR). This report provides every course coordinator with an annual snapshot of their performance data evaluated against QUT and national benchmarks. In this article, the impact of the ICR is explored through the case study of one undergraduate course identified as underperforming. The case study features an innovative, ethnographic approach to working with course teams and highlights the importance of context, collaboration and appropriate support in creating evidence-based action plans for course improvement.

Gas-phase reactions of aryl radicals with 2-butyne : an experimental and theoretical investigation employing the N-methyl-pyridinium-4-yl radical cation

Aromatic radicals form in a variety of reacting gas-phase systems, where their molecular weight growth reactions with unsaturated hydrocarbons are of considerable importance. We have investigated the ion-molecule reaction of the aromatic distonic N-methyl-pyridinium-4-yl (NMP) radical cation with 2-butyne (CH3C CCH3) using ion trap mass spectrometry. Comparison is made to high-level ab initio energy surfaces for the reaction of NMP and for the neutral phenyl radical system. The NMP radical cation reacts rapidly with 2-butyne at ambient temperature, due to the apparent absence of any barrier. The activated vinyl radical adduct predominantly dissociates via loss of a H atom, with lesser amounts of CH3 loss. High-resolution Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry allows us to identify small quantities of the collisionally deactivated reaction adduct. Statistical reaction rate theory calculations (master equation/RRKM theory) on the NMP + 2-butyne system support our experimental findings, and indicate a mechanism that predominantly involves an allylic resonance-stabilized radical formed via H atom shuttling between the aromatic ring and the C-4 side-chain, followed by cyclization and/or low-energy H atom beta-scission reactions. A similar mechanism is demonstrated for the neutral phenyl radical (Ph center dot)+2-butyne reaction, forming products that include 3-methylindene. The collisionally deactivated reaction adduct is predicted to be quenched in the form of a resonance-stabilized methylphenylallyl radical. Experiments using a 2,5-dichloro substituted methyl-pyridiniumyl radical cation revealed that in this case CH3 loss from the 2-butyne adduct is favoured over H atom loss, verifying the key role of ortho H atoms, and the shuttling mechanism, in the reactions of aromatic radicals with alkynes. As well as being useful phenyl radical analogues, pyridiniumyl radical cations may form in the ionosphere of Titan, where they could undergo rapid molecular weight growth reactions to yield polycyclic aromatic nitrogen hydrocarbons (PANHs).

Long-term outcomes following Medtronic Open Pivot valved conduit

Aortic root replacement is a complex procedure, though subsequent modifications of the original Bentall procedure have made surgery more reproducible. The study aim was to examine the outcomes of a modified Bentall procedure, using the Medtronic Open PivotTM valved conduit. Whilst short-term data on the conduit and long-term data on the valve itself are available, little is known of the long-term results with the valved conduit. Patients undergoing aortic root replacement between February 1999 and February 2010, using the Medtronic Open Pivot valved conduit were identified from the prospectively collected Cardiothoracic Register at The Prince Charles Hospital, Brisbane, Australia. All patients were followed up echocardiographically and clinically. The primary end-point was death, and a Cox proportional model was used to identify factors associated.with survival. Secondary end-points were valve-related morbidity (as defined by STS guidelines) and postoperative morbidity. Predictors of morbidity were identified using logistic regression. A total of 246 patients (mean age 50 years) was included in the study. The overall mortality was 12%, with actuarial 10-year survival 79% and a 10-year estimate of valve-related death of 0.04 (95% CI: 0.004, 0.07). Preoperative myocardial infarction (p = 0.004, HR 4.74), urgency of operation (p = 0.038, HR 2.8) and 10% incremental decreases in ejection fraction (p = 0.046, HR 0.69) were predictive of mortality. Survival was also affected by the valve gradients, with a unit increase in peak gradient reducing mortality (p = 0.021, HR 0.93). Valve-related morbidity occurred in 11 patients. Urgent surgery (p <0.001, OR 4.12), aortic dissection (p = 0.015, OR 3.35), calcific aortic stenosis (p = 0.016, OR 2.35) and Marfan syndrome (p 0.009, OR 3.75) were predictive of postoperative morbidity. The reoperation rate was 1.2%. The Medtronic Open Pivot valved conduit is a safe and durable option for aortic root replacement, and is associated with low morbidity and 10-year survival of 79%. However, further studies are required to determine the effect of valve gradient on survival.

Kirjallisuusosa: Alzheimerin taudin rottamallien vastaavuus tautiin ihmisessä ja mallien käyttökelpoisuus

Kirjallisuusosa: Alzheimerin taudin hoitoon olisi tarvetta uusille taudinkulkuun vaikuttaville lääkeaineille. Niiden kehittämiseksi tarvitaan eläinmalleja, joissa esiintyy taudin patofysiologisia piirteitä. Rottamalleista vanhemmat skopolamiini- tai MK-801-häirintä sekä ikääntyneiden rottien käyttö eivät kovin hyvin vastaa taudin patofysiologiaa, vaikka niissä eläimen muisti käyttäytymiskokeissa onkin heikentynyt. Uudemmat transgeeniset rottamallit ja mallit, joissa annetaan Aβ:a aivoihin, ilmentävät huomattavasti paremmin Alzheimerin taudin kaltaista tilaa aivoissa ainakin Aβ:n osalta. Taupatofysiologiaa ei silti kummassakaan näistä malleista juuri esiinny. Toisaalta Aβ:lla näyttäisi olevan huomattavasti tau:ta suurempi rooli taudissa, joten sen ilmeneminen mallissa onkin keskeisempi tekijä. Nämä mallit ilmentävät melko suurelti osin yhtä hyvin Alzheimerin taudin patofysiologiaa. Aβ:n antaminen on hieman yksinkertaisempi suorittaa käytännössä, sillä siinä ei tarvitse luoda transgeenista kantaa. Toisaalta transgeenisessa mallissa Aβ-patofysiologia syntyy enemmän Alzheimerin taudin kaltaisesti solujen sisällä eikä valmiita aggregoituvia Aβ-peptidejä anneta ulkopuolelta aivoihin. Molemmat mallit ovat kuitenkin käyttökelpoisia, ja soveltuvat erityisesti Aβ:an vaikuttavien lääkeaineiden kehittämiseen. Kokeellinen osa: Kokeen tarkoituksena oli validoida kohotettu ristikko-sokkelo (elevated plus-maze, EPM) hiirillä kognitiomallina. Kokeessa käytettiin kahden koekerran (trial, T) menetelmää, jossa koekertojen pituus oli viisi minuuttia. Näin saatiin useita oppimista kuvaavia parametreja. Hiirille yritettiin saada muistihäiriö aikaviiveen avulla (koekertojen väli 1-18 vrk) tai antamalla muskariinireseptoriantagonistia skopolamiinia (0,1-0,8 mg/kg i.p.) 30 minuuttia ennen T1:tä. Nämä kokeet suoritettiin sekä C57BL/6J- että ICR:(CD-1)-hiirillä. Aikaviivekokeissa ainut ryhmä, jolla oli viitettä unohtamisesta, oli ICR:(CD-1)-hiirien 18 vrk:n ryhmä. Tämän perusteella tutkittiin vielä 21 vuorokauden aikaväli, mutta selvää muistihäiriötä ei esiintynyt. Skopolamiini ei häirinnyt muistia ICR:(CD-1)-hiirillä, mutta C57BL/6J-hiirillä 0,2 mg/kg:n annoksesta ylöspäin merkitsevä muistihäiriö esiintyi. Näin ollen jatkokokeissa käytettäväksi valittiin skopolamiinin annos 0,2 mg/kg C57BL/6J-hiirillä, ja siinä tutkittiin donepetsiilin (0,3, 0,8 ja 1,5 mg/kg s.c), memantiinin (5,0 ja 10,0 mg/kg s.c) ja kokeellisen 5-HT6-antagonistin SB742457:n (1,5 ja 6,0 mg/kg s.c) muistia parantavia vaikutuksia. Tutkittavat lääkeaineet annettiin 40 minuuttia ennen T1:tä ja skopolamiini 30 minuuttia ennen. Memantiinilla (5,0 mg/kg) oli selkeä skopolamiinin heikentämää kognitiota parantava vaikutus ja donepetsiilillakin (1,5 mg/kg) suuntaus tähän. Tulosten perusteella malli näyttäisi soveltuvan muisti- ja oppimisvaikutusten tutkimiseen käytettäväksi malliksi.

Correlation of Calcification on Excised Aortic Valves by Micro-Computed Tomography with Severity of Aortic Stenosis

Background and aim of the study: The quantification of incidentally found aortic valve calcification on computed tomography (CT) is not performed routinely, as data relating to the accuracy of aortic valve calcium for estimating the severity of aortic stenosis (AS) is neither consistent nor validated. As aortic valve calcium quantification by CT is confounded by wall and coronary ostial calcification, as well as motion artifact, the ex-vivo micro-computed tomography (micro-CT) of stenotic aortic valves allows a precise measurement of the amounts of calcium present. The study aim, using excised aortic valves from patients with confirmed AS, was to determine if the amount of calcium on micro-CT correlated with the severity of AS. Methods: Each of 35 aortic valves that had been excised from patients during surgical valve replacement were examined using micro-CT imaging. The amount of calcium present was determined by absolute and proportional values of calcium volume in the specimen. Subsequently, the correlation between calcium volume and preoperative mean aortic valve gradient (MAVG), peak transaortic velocity (V-max), and aortic valve area (AVA) on echocardiography, was evaluated. Results: The mean calcium volume across all valves was 603.2 +/- 398.5 mm(3), and the mean ratio of calcium volume to total valve volume was 0.36 +/- 0.16. The mean aortic valve gradient correlated positively with both calcium volume and ratio (r = 0.72, p <0.001). V-max also correlated positively with the calcium volume and ratio (r = 0.69 and 0.76 respectively; p <0.001). A logarithmic curvilinear model proved to be the best fit to the correlation. A calcium volume of 480 mm(3) showed sensitivity and specificity of 0.76 and 0.83, respectively, for a diagnosis of severe AS, while a calcium ratio of 0.37 yielded sensitivity and specificity of 0.82 and 0.94, respectively. Conclusion: A radiological estimation of calcium amount by volume, and its proportion to the total valve volume, were shown to serve as good predictive parameters for severe AS. An estimation of the calcium volume may serve as a complementary measure for determining the severity of AS when aortic valve calcification is identified on CT imaging. The Journal of Heart Valve Disease 2012;21:320-327

Optimum steering input determination and path-tracking of all-wheel steer vehicles on uneven terrains based on constrained optimization

In this paper we propose a framework for optimum steering input determination of all-wheel steer vehicles (AWSV) on rough terrains. The framework computes the steering input which minimizes the tracking error for a given trajectory. Unlike previous methodologies of computing steering inputs of car-like vehicles, the proposed methodology depends explicitly on the vehicle dynamics and can be extended to vehicle having arbitrary number of steering inputs. A fully generic framework has been used to derive the vehicle dynamics and a non-linear programming based constrained optimization approach has been used to compute the steering input considering the instantaneous vehicle dynamics, no-slip and contact constraints of the vehicle. All Wheel steer Vehicles have a special parallel steering ability where the instantaneous centre of rotation (ICR) is at infinity. The proposed framework automatically enables the vehicle to choose between parallel steer and normal operation depending on the error with respect to the desired trajectory. The efficacy of the proposed framework is proved by extensive uneven terrain simulations, for trajectories with continuous or discontinuous velocity profile.

Applications of a Concise and General Strategy for the Syntheses of Transtaganolide and Basiliolide Natural Products

Herein are described the total syntheses of all members of the transtaganolide and basiliolide natural product family. Utilitzation of an Ireland–Claisen rearrangement/Diels–Alder cycloaddition cascade (ICR/DA) allowed for rapid assembly of the transtaganolide and basiliolide oxabicyclo[2.2.2]octane core. This methodology is general and was applicable to all members of the natural product family.

A brief introduction outlines all the synthetic progress previously disclosed by Lee, Dudley, and Johansson. This also includes the initial syntheses of transtaganolides C and D, as well as basiliolide B and epi-basiliolide B accomplished by Stoltz in 2011. Lastly, we discuss our racemic synthesis of basililide C and epi-basiliolide C, which utilized an ICR/DA cascade to constuct the oxabicyclo[2.2.2]octane core and formal [5+2] annulation to form the ketene-acetal containing 7-membered C-ring.

Next, we describe a strategy for an asymmetric ICR/DA cascade, by incorporation of a chiral silane directing group. This allowed for enantioselective construction of the C8 all-carbon quaternary center formed in the Ireland–Claisen rearrangement. Furthermore, a single hydride reduction and subsequent translactonization of a C4 methylester bearing oxabicyclo[2.2.2]octane core demonstrated a viable strategy for the desired skeletal rearrangement to obtain pentacyclic transtaganolides A and B. Application of the asymmetric strategy culminated in the total syntheses of (–)-transtaganolide A, (+)-transtaganolide B, (+)-transtaganolide C, and (–)-transtaganolide D. Comparison of the optical rotation data of the synthetically derived transtaganolides to that from the isolated counterparts has overarching biosynthetic implications which are discussed.

Lastly, improvement to the formal [5+2] annulation strategy is described. Negishi cross-coupling of methoxyethynyl zinc chloride using a palladium Xantphos catalyst is optimized for iodo-cyclohexene. Application of this technology to an iodo-pyrone geranyl ester allowed for formation and isolation of the eneyne product. Hydration of the enenye product forms natural metabolite basiliopyrone. Furthermore, the eneyne product can undergo an ICR/DA cascade and form transtaganolides C and D in a single step from an achiral monocyclic precursor.

软电离质谱在蛋白质组分析和生物活性分子表征中的应用

随着软电离技术的发展，特别是基质辅助激光解析（MALDI）和电喷雾（ESI）两种软电离技术的出现，使质谱分析生物大分子成为可能，将质谱的应用范围迅速扩展到生命科学的诸多研究领域，特别是成为了蛋白质组分析，医学诊断，药物分析等领域不可替代的新工具。首先，采用凝胶电泳与傅立叶变换离子回旋共振质谱（FT-ICR MS）的高分辨率和高质量精确度性能相结合的新方法，对不同肺病患者的支气管肺泡灌洗液进行了快速直接的蛋白质组分析，为肺疾病诊断学、肺病相关机理的研究以及高分辨质谱在蛋白质组分析中的应用奠定了基础。一维（1-D）和二维（2-D）凝胶电泳与高分辨FT-ICR MS相结合，对慢性支气管炎（cblonic broncnitis，CB）和囊泡纤维化（cystic fibrosis，CF）患者的支气管肺泡灌洗液（BALF）中表面蛋白A和D进行了鉴定；并对表面蛋白的翻译后修饰（hydroxy-prollne）进行了直接的确定；对来自于不同肺泡蛋白沉积症（PAP）患者的BALF中的特异性蛋白进行了鉴定，鉴定出表面蛋白A的两个降解片段，为研究与肺病相关的SP-A降解产物的可能降解途径提供了初步的信息。证实了FT-ICR MS的高分辨率和高质量精确度在蛋白质的鉴定过程中的突出作用：（i）利用单个多肤的精确质量，可以避免依赖离子的串联质谱数据进行蛋白质鉴定，即无需对谱图中的离子进行串联质谱分析，就可实现蛋白质或蛋白质混合物的快速、确切的鉴定；（ii）在数据库检索中应用很小的误差范围可以大大提高蛋白质鉴定时的选择性；（iii）通过来自于微量蛋白质的少量肤峰就可以进行蛋白质的准确鉴定。通过MALDI/EST FT-ICR MS、园二色谱（CD）和H／D交换实验（hydrogedeuteriuln exchange）对一系列人SP-C及其类似物进行了表征。证实了溶液相中FFI-SP-C和rh-SP-C的非共价二聚体的存在；研究了人SP-C在有机溶剂中的构象变化和聚集行为，为探讨肺病相关机理奠定了基础。其次，以电喷雾多级串联质谱为研究手段，对部分生物类黄酮及其络合物进行系统的质谱研究，发现二氢黄酮及二氢黄酮醇类化合物在电喷雾条件负离子模式下具有不同的特征质谱行为，为质谱区分这两类化合物提供了重要的依据；黄酮金属络合物的研究中，四种二价过渡金属（Cu（II），Zn，Mn（II）和Fe（II））与芸香普均可以形成络合物，探讨了芸香普一铜络合物软电离条件下的碎裂机理，并利用多级串联质谱数据探讨了络合物C和D的结构，为质谱方法探讨金属清除疾病相关自由基的机理以及提高金属的生物利用度奠定了基础。

人胚胎干细胞建系及向神经细胞定向分化的研究

研究和利用人胚胎干细胞(hES)细胞已成为生命科学领域的核心问题之一。当前hES 细胞研究主要集中在hES 的建系和维持其不分化状态；提高hES 细胞定向分化为特定 细胞的比例；ES 细胞自我更新和分化的机制等方面。本论文一方面概述了hES 细胞相 关领域的研究进展；另一方面建立了不同培养体系条件下3 株hES 细胞，并在此基础 上利用G5 和肝生长因子（HGF）诱导hES 细胞定向分化成高纯度的NPs。主要结论如 下：1) 建立人卵体外受精和胚胎培养体系。获得了15 个囊胚，采用了免疫外科法分离 内细胞团，运用含血清以及不含血清的培养体系，在ICR 小鼠胚胎成纤维饲养层上分 别建立了YKh-1、YKh-2 和YKh-3 3 株人胚胎干细胞系，生长良好，核型正常。ES 细 胞表达碱性磷酸酶活性、SSEA-3、SSEA-4、TRA-1-60、TRA-1-81 和Oct-4，但不表达 SSEA-1； ES 细胞在体外能够分化为属于外胚层、中胚层和内胚层的各种分化细胞， 在SCID 小鼠体内能形成畸胎瘤，畸胎瘤包括了所有三个胚层来源的细胞类型。证实了 ES 细胞系的多向分化潜能。2) 对比含血清以及无血清的培养体系的hES 细胞系的特征， 观察了其集落形态、生长速度、分化能力。结果表明，在含血清培养体系的Yhk-2，其 集落形态较致密，含2-3 个核的细胞较多，细胞倍增时间为43.9±5.7h；而在无血清培 养体系的Yhk-3，其集落形态较铺展，细胞较小而圆，倍增时间为34.8±3.8h。细胞免疫 染色和PCR 结果表明，二者在体外都能分化为三个胚层来源的多种细胞，但比例有所 差异。提示二者在向三个胚层来源的细胞的分化能力上有所不同。 3) 以所建立的hES 细胞系为模型，采用HGF 和G5 作为诱导因子添加到神经诱导培养基中，诱导hES 细 胞分化成高纯度的NPs。单独的HGF 或G5 仅能诱导ES 细胞分化成70.9± 5.0%和 72.9±7.2%NPs，而联用HGF 和G5 使NPs 的比率达到91.2±11.2%，进一步纯化后获得 98±3.2%的NPs。获得的NPs 能分化成三个谱系神经细胞，亚克隆实验也进一步证明采 用HGF+G5 获得的单个NPs 具有神经干细胞的特性，也能在体外分化成三个谱系的神 经细胞。用SHH 处理NPs，获得的分化细胞表达不同脑区标志，表明所得到NPs 具有 对脑区信号发生反应，进一步分化为不同脑区神经元细胞的能力。 本实验建立了具有自主知识产权的中国人源胚胎干细胞系，建立了ES 细胞的含血 清以及无血清的培养体系和向神经前体细胞定向分化系统，得到高比例的神经前体细 胞，为进一步研究利用人胚胎干细胞打下良好的基础。