Measurement of the ratio of the p(p)over-bar -> W + c-jet cross section to the inclusive p(p)over-bar -> W + jets cross section

We present a measurement of the fraction of inclusive W +jets events produced with net charm quantum number 11, denoted W + c-jet, in p collisions at root s = 1.96 TeV using approximately 1 fb(-1) of data collected by the do detector at the Fermilab Tevatron Collider. We identify the W +jets events via the leptonic W boson decays. Candidate W + c-jet events are selected by requiring a jet containing a muon in association with a reconstructed W boson and exploiting the charge correlation between this muon and W boson decay lepton to perform a nearly model-independent background subtraction. We measure the fraction of W + c-jet events in the inclusive W +jets sample for jet PT > 20 GeV and pseudorapidity |eta| < 2.5 to be 0.074 +/- 0.019(stat.) +/-(0.012)(0.014) (syst.), in agreement with theoretical predictions. The probability that background fluctuations could produce the observed fraction of W + c-jet events is estimated to be 2.5 x 10(-4), which corresponds to a 3.5 sigma statistical significance. Published by Elsevier B.V.

Direct measurement of oligonucleotide binding stoichiometry of gene V protein by mass spectrometry.

The binding stoichiometry of gene V protein from bacteriophage f1 to several oligonucleotides was studied using electrospray ionization-mass spectrometry (ESI-MS). Using mild mass spectrometer interface conditions that preserve noncovalent associations in solution, gene V protein was observed as dimer ions from a 10 mM NH4OAc solution. Addition of oligonucleotides resulted in formation of protein-oligonucleotide complexes with stoichiometry of approximately four nucleotides (nt) per protein monomer. A 16-mer oligonucleotide gave predominantly a 4:1 (protein monomer: oligonucleotide) complex while oligonucleotides shorter than 15 nt showed stoichiometries of 2:1. Stoichiometries and relative binding constants for a mixture of oligonucleotides were readily measured using mass spectrometry. The binding stoichiometry of the protein with the 16-mer oligonucleotide was measured independently using size-exclusion chromatography and the results were consistent with the mass spectrometric data. These results demonstrate, for the first time, the observation and stoichiometric measurement of protein-oligonucleotide complexes using ESI-MS. The sensitivity and high resolution of ESI-MS should make it a useful too] in the study of protein-DNA interactions.

Temporally dependent C, N, and P dynamics associated with the decay of Rhizophora mangle L. leaf litter in oligotrophic mangrove wetlands of the Southern Everglades

We performed two litter decomposition experiments using nearly-senesced red mangrove (Rhizophora mangle L.) leaves collected from an Everglades dwarf mangrove wetland to understand the short-term (3 weeks) and long-term (1 year) changes in mass, as well as C-, N-, and P-content of decomposing leaf litter. We expected that leaves decomposing in this oligotrophic environment would be short-term sources of C, N, and P, but potential long-term sinks for N and P. In May 1998, we conducted a 3-week leaching experiment, incubating fresh, individual leaves in seawater for up to 21 days. From May 1997 to May 1998, leaf litter in mesh bags decomposed on the forest floor at two dwarf mangrove sites. Leaching accounted for about 33% loss of dry mass from R. mangle leaves after 3 weeks. Leaching losses were rapid, peaking by day 2, and large, with leachate concentrations of total organic carbon (TOC) and total phosphorus (TP) increasing by more than an order of magnitude after 3 weeks. Mean leaf C:N increased from 105 to 115 and N:P increased from a mean of 74 to 95 after 21 days, reflecting the relatively large leaching losses of N and P. Loss of mass in the litterbags leveled off after 4 months, with roughly 60%dry mass remaining (DMR) after nearly 1 year of decomposition. The mass of carbon in each litterbag declined significantly after 361 days, but the mass of nitrogen and phosphorus doubled, indicating long-term accumulation of these constituents into the detritus. Subsequently, the leaf C:N ratio dropped significantly from 90 to 34 after 361 days. Following an initial 44-day increase, leaf N:P decreased from 222 to 144, reflecting high accumulation of P relative to N. A review of several estuarine macrophyte decomposition studies reveals a trend in nitrogen accumulation through time regardless of site, but suggests no clear pattern for C and P. We believe that the increase in litter P observed in this study was indicative of the P-limited status of the greater Everglades ecosystem and that decomposing mangrove litter may represent a substantial phosphorus pool in the system.

Mancha foliar e desfolha causada por Cylindrocladium spp. em genótipos de eucalipto no Acre, Amazônia.

Este trabalho teve como objetivo avaliar a severidade da mancha foliar e da desfolha em genótipos de eucalipto em experimentos instalados no Campo Experimental da Embrapa Acre.

MITIE C-Arm - Advanced innovation in education

Aim: In 2013 QUT introduced the Medical Imaging Training Immersive Environment (MITIE) as a virtual reality (VR) platform that allowed students to practice general radiography. The system software has been expanded to now include C-Arm. The aim of this project was to investigate the use of this technology in the pedagogy of undergraduate medical imaging students who have limited to no experience in the use of the C-Arm clinically. Method: The Medical Imaging Training Immersive Environment (MITIE) application provides students with realistic and fully interactive 3D models of C-Arm equipment. As with VR initiatives in other health disciplines (1–2) the software mimics clinical practice as much as possible and uses 3D technology to enhance 3D spatial awareness and realism. The application allows students to set up and expose a virtual patient in a 3D environment as well as creating the resultant “image” for comparison with a gold standard. Automated feedback highlights ways for the student to improve their patient positioning, equipment setup or exposure factors. The students' equipment knowledge was tested using an on line assessment quiz and surveys provided information on the students' pre-clinical confidence scale, with post-clinical data comparisons. Ethical approval for the project was provided by the university ethics panel. Results: This study is currently under way and this paper will present analysis of initial student feedback relating to the perceived value of the application for confidence in a high risk environment (i.e. operating theatre) and related clinical skills development. Further in-depth evaluation is ongoing with full results to be presented. Conclusion: MITIE C-Arm has a development role to play in the pre-clinical skills training for Medical Radiation Science students. It will augment their theoretical understanding prior to their clinical experience. References 1. Bridge P, Appleyard R, Ward J, Phillips R, Beavis A. The development and evaluation of a virtual radiotherapy treatment machine using an immersive visualisation environment. Computers and Education 2007; 49(2): 481–494. 2. Gunn T, Berry C, Bridge P et al. 3D Virtual Radiography: Development and Initial Feedback. Paper presented at the 10th Annual Scientific Meeting of Medical Imaging and Radiation Therapy, March 2013 Hobart, Tasmania.

Different Modes of Transactivation of Bacteriophage Mu Late Promoters by Transcription Factor C

Transactivator protein C is required for the expression of bacteriophage Mu late genes from lys, I, P and mom promoters during lytic life cycle of the phage. The mechanism of transcription activation of mom gene by C protein is well understood. C activates transcription at Pmom by initial unwinding of the promoter DNA, thereby facilitating RNA polymerase (RNAP) recruitment. Subsequently, C interacts with the (sic) subunit of RNAP to enhance promoter clearance. The mechanism by which C activates other late genes of the phage is not known. We carried out promoter-polymerase interaction studies with all the late gene promoters to determine the individual step of C mediated activation. Unlike at P-mom, at the other three promoters, RNAP recruitment and closed complex formation are not C dependent. Instead, the action of C at P-lys, P-I, and P-P is during the isomerization from closed complex to open complex with no apparent effect at other steps of initiation pathway. The mechanism of transcription activation of mom and other late promoters by their common activator is different. This distinction in the mode of activation (promoter recruitment and escape versus isomerization) by the same activator at different promoters appears to be important for optimized expression of each of the late genes.

Wnt and FGF signaling in C. elegans vulval cell lineage polarity

The interpretation of extracellular cues leading to the polarization of intracellular components and asymmetric cell divisions is a fundamental part of metazoan organogenesis. The C. elegans vulva, with its invariant cell lineage and interaction of multiple cell signaling pathways, provides an excellent model for the study of cell polarity within an organized epithelial tissue. Herein I discuss the interaction of Wnt and FGF signaling in controlling vulval cell lineage polarity with emphasis on the posterior-most cell that forms the vulva, P7.p.

The mirror symmetry of the C. elegans vulva is achieved by the opposite division orientation of the vulval precursor cells (VPCs) flanking the axis of symmetry. Opposing Wnt signals control the division patterns of the VPCs by controlling the localization of SYS-1/ β-catenin toward the direction of the Wnt gradient. Multiple Wnt signals, expressed at the axis of symmetry, promote the wild-type, anterior-facing, P7.p orientation, whereas Wnts EGL-20 and CWN-1 from the tail and posterior body wall muscle, respectively, promote the daughter cells of P7.p to face the posterior. EGL-20 acts through a member of the LDL receptor superfamily, LRP-2, along with Ror/CAM-1 and Van Gogh/VANG-1. All three transmembrane proteins control orientation through the localization of the SYS-1.

The Fibroblast Growth Factor (FGF) pathway acts in concert with LIN-17/Frizzled to regulate the localization of SYS-1. The source of the FGF ligand is the 1° VPC, P6.p, which controls the polarity of the neighboring 2° VPC, P7.p, by signaling through the sex myoblasts (SMs), activating the FGF pathway. The Wnt, cwn-1, is expressed in the posterior body wall muscle of the worm as well as the SMs, making it the only Wnt expressed on the posterior and anterior sides of P7.p at the time of the polarity decision. Both sources of cwn-1 act instructively to influence P7.p polarity in the direction of the Wnt gradient. The FGF pathway leads to the regulation of cwn-1 transcripts in the SMs. These results illustrate the first evidence of the interaction between FGF and Wnt in C. elegans development and vulval cell lineage polarity as well as highlight the promiscuous nature of Wnt signaling within C. elegans.

Signal transduction, regulation, and developmental logic of EGFR signalling in C. elegans

RTKs-mediated signaling systems and the pathways with which they interact (e.g., those initiated by G protein-mediated signaling) involve a highly cooperative network that sense a large number of cellular inputs and then integrate, amplify, and process this information to orchestrate an appropriate set of cellular responses. The responses include virtually all aspects of cell function, from the most fundamental (proliferation, differentiation) to the most specialized (movement, metabolism, chemosensation). The basic tenets of RTK signaling system seem rather well established. Yet, new pathways and even new molecular players continue to be discovered. Although we believe that many of the essential modules of RTK signaling system are rather well understood, we have relatively little knowledge of the extent of interaction among these modules and their overall quantitative importance.

My research has encompassed the study of both positive and negative signaling by RTKs in C. elegans. I identified the C. elegans S0S-1 gene and showed that it is necessary for multiple RAS-mediated developmental signals. In addition, I demonstrated that there is a SOS-1-independent signaling during RAS-mediated vulval differentiation. By assessing signal outputs from various triple mutants, I have concluded that this SOS-1-independent signaling is not mediated by PTP-2/SHP-2 or the removal of inhibition by GAP-1/ RasGAP and it is not under regulation by SLI-1/Cb1. I speculate that there is either another exchange factor for RASor an as yet unidentified signaling pathway operating during RAS-mediated vulval induction in C. elegans.

In an attempt to uncover the molecular mechanisms of negative regulation of EGFR signaling by SLI-1/Cb1, I and two other colleagues codiscovered that RING finger domain of SLI-1 is partially dispensable for activity. This structure-function analysis shows that there is an ubiquitin protein ligase-independent activity for SLI-1 in regulating EGFR signaling. Further, we identified an inhibitory tyrosine of LET-23/ EGFR requiring sli-1(+)for its effects: removal of this tyrosine closely mimics loss of sli-1 but not loss of other negative regulator function.

By comparative analysis of two RTK pathways with similar signaling mechanisms, I have found that clr-1, a previously identified negative regulator of egl-15 mediated FGFR signaling, is also involved in let-23 EGFR signaling. The success of this approach promises a similar reciprocal test and could potentially extend to the study of other signaling pathways with similar signaling logic.

Finally, by correlating the developmental expression of lin-3 EGF to let-23 EGFR signaling activity, I demonstrated the existence of reciprocal EGF signaling in coordinating the morphogenesis of epithelia. This developmental logic of EGF signaling could provide a basis to understand a universal mechanism for organogenesis.

I. The 3.7 Å crystal structure of horse heart ferricytochrome C. II. The application of the Karle-Hauptman tangent formula to protein phasing

I. The 3.7 Å Crystal Structure of Horse Heart Ferricytochrome C.

The crystal structure of horse heart ferricytochrome c has been determined to a resolution of 3.7 Å using the multiple isomorphous replacement technique. Two isomorphous derivatives were used in the analysis, leading to a map with a mean figure of merit of 0.458. The quality of the resulting map was extremely high, even though the derivative data did not appear to be of high quality.

Although it was impossible to fit the known amino acid sequence to the calculated structure in an unambiguous way, many important features of the molecule could still be determined from the 3.7 Å electron density map. Among these was the fact that cytochrome c contains little or no α-helix. The polypeptide chain appears to be wound about the heme group in such a way as to form a loosely packed hydrophobic core in the molecule.

The heme group is located in a cleft on the molecule with one edge exposed to the solvent. The fifth coordinating ligand is His 18 and the sixth coordinating ligand is probably neither His 26 nor His 33.

The high resolution analysis of cytochrome c is now in progress and should be completed within the next year.

II. The Application of the Karle-Hauptman Tangent Formula to Protein Phasing.

The Karle-Hauptman tangent formula has been shown to be applicable to the refinement of previously determined protein phases. Tests were made with both the cytochrome c data from Part I and a theoretical structure based on the myoglobin molecule. The refinement process was found to be highly dependent upon the manner in which the tangent formula was applied. Iterative procedures did not work well, at least at low resolution.

The tangent formula worked very well in selecting the true phase from the two possible phase choices resulting from a single isomorphous replacement phase analysis. The only restriction on this application is that the heavy atoms form a non-centric cluster in the unit cell.

Pages 156 through 284 in this Thesis consist of previously published papers relating to the above two sections. References to these papers can be found on page 155.

Composição elementar corporal, desbalanço alimentar e reciclagem de nutrientes em peixes de um riacho costeiro de Mata Atlântica

No presente estudo foi avaliada a variação na dieta e na composição elementar corporal (C:N:P) de oito espécies de peixes que coocorrem em dois trechos de um riacho. Além disso, foram investigadas as diferenças na demanda e excreção de nutrientes por duas espécies de Loricariidae, sendo uma nativa (Hypostomus punctatus) e a outra não nativa (Parotocinclus maculicauda). As coletas foram realizadas no rio Ubatiba, através de pesca elétrica em diferentes meses entre os anos de 2010 e 2012. A partir da análise alimentar, observamos que as espécies apresentaram variação na dieta entre as localidades, com exceção das duas espécies de Characidium. Apesar destas variações, o presente estudo corroborou a hipótese de homeostase estequiométrica corporal. A exceção foi a espécie Hoplias malabaricus que apresentou variação na concentração elementar corporal e alto desbalanço alimentar entre as localidades, sendo as diferenças mais acentuadas na área aberta. Analisando as diferenças na demanda nutricional dos Loricariidae verificamos uma maior concentração corporal de carbono e nitrogênio para a espécie nativa e maior de fósforo na espécie não nativa, sendo essa diferença confirmada por um maior consumo de fósforo pela espécie não nativa. A análise da excreção revelou que a espécie nativa excreta mais nitrogênio e fósforo que a não nativa. Sendo assim, os resultados sugerem que a espécie não nativa apresenta uma requisição de fósforo maior do que a nativa. Logo, ambientes com altas concentrações de nutrientes, tal como o riacho estudado, podem favorecer o estabelecimento desta espécie

大白花杜鹃菌根真菌多样性的研究

杜鹃花属(Rhododendron L.)植物分布广泛，研究发现所有的杜鹃花科植物都能形成一种特殊的菌根——杜鹃花类菌根(Ericoid Mycorrhiza)。杜鹃花类菌根对杜鹃花科植物在营养胁迫的环境下生长起到重要的作用。近几年，对杜鹃花类菌根的生物学和生态功能的研究越来越重视。我国是杜鹃花属植物资源最为丰富的国家，因此研究杜鹃花属植物菌根真菌多样性，充分利用杜鹃花特有的菌根资源，促进杜鹃花迁地保护成功具有重大的意义。 本研究以分布较广并且是中国特有的杜鹃花属植物——大白花杜鹃(Rhododendron decorum Franch.)的野生植株为研究对象，应用直接扩增根中真菌ITS区的分子鉴定方法和T-RFLP(末端限制性片段长度多态性)的分析方法，来研究其菌根真菌的多样性；并结合生态化学计量学特征分析、宿主遗传相似性及其群落组成分析等内容，探讨大白花杜鹃的菌根真菌－宿主植物－根际土壤三者之间的关系。主要结果如下： (1)通过用直接扩增真菌ITS区序列，揭示了大白花杜鹃根部真菌的多样性，本研究发现，野生大白杜鹃根部的真菌种类比较丰富，至少有26个ITS-taxa，包括子囊菌和担子菌共5个真菌目：Helotiales、Lecanorales(≡Agyriales)、Onygenales、Sebacinales和Thelephorales，其中包括典型的ERM真菌——树粉孢属Oidiodendron sp.(Myxotrichaceae)真菌。另外还发现了黑色有隔内生菌(Dark septate endophyte，DSE)以及一些未命名的子囊菌。担子菌在本研究中占有较大比例，尤其是蜡壳耳菌目真菌；此外还有较典型的外生菌根真菌——革菌目真菌。 (2)大白花杜鹃野生植株与栽培植株在菌根真菌种类组成上，有一定的相似性；在忽略种源差异等条件下相较而言，前者的物种丰富度远高于后者。 (3)大白花杜鹃菌根真菌多样性和丰富度同它的根际土壤与叶片的C、N、P含量以及C/N、N/P、土壤pH值、宿主的海拔高度等都没有显著的相关关系。 (4)在大白花杜鹃的菌根真菌群落组成方面，整体上保持了相当程度的相似性，同时还保持了一定水平的差异；大白杜鹃菌根真菌的种类是丰富的，优势度指数表明其多样性水平很高。 (5)大白花杜鹃的遗传距离与其菌根真菌群落组成结构有极显著的相关关系，宿主的种内遗传差异可能对菌根真菌群落物种组成产生选择偏好。 (6)大白花杜鹃的群落组成与其菌根真菌群落组成有极为显著的关联性，伴生种的菌根类型可能会影响宿主植物菌根真菌的物种组成结构。

全球变化背景下科尔沁沙地生态系统C、N循环过程

工业革命以来，由于人口的快速增加和人类活动的强烈干扰（主要包括煤炭、石油等石化燃料的燃烧、化肥生产和使用）导致土地利用/覆被变化、大气CO2浓度升高、N沉降等一系列全球环境变化问题。有关陆地生态系统生物地球化学循环，尤其是陆地生态系统C、N循环及其耦合过程方面的研究成为全球变化科学研究领域的重要内容。 干旱/半干旱地区占地球陆地总面积的1/3。与湿润地区相比较，干旱/半干旱地区生态系统稳定性比较差，往往属于生态脆弱区。因此，全球变化对干旱/半干旱地区生态系统影响更加敏感。科尔沁沙地位于我国北方干旱/半干旱地区，是我国典型的农牧交错区和生态脆弱区。科尔沁沙地是世界上人口密度最高的干旱/半干旱地区之一，人类活动对其影响剧烈。然而，有关科尔沁沙地生态系统C、N元素生物地球化学循环过程对土地利用/覆被变化、N沉降等全球变化响应及其反馈机制的研究非常缺乏。因此，本文以科尔沁沙地退化沙质草地、农田、不同年龄樟子松和杨树人工林等生态系统为对象，开展了造林、模拟N沉降和凋落物管理对生态系统C、N元素循环过程影响的研究。 在科尔沁沙地东南缘，以退化沙质草地、樟子松（Pinus sylvestris var. mongolica）人工林（15、24和30年生）、杨树（Poplus xiaozhuanica）人工林（7、11和15年生）为对象，研究草地转变为林地对生态系统C、N储量影响；以退化草地、榆树疏林草地和32年生樟子松人工林为对象，比较草地造林对土壤C、N循环过程及其土壤微生物性状的影响；以农田和5、10、15年生杨树人工林为对象，研究退耕还林对生态系统C、N储量和循环过程影响；以35年生樟子松人工林为对象，模拟研究N沉降和凋落物管理对生态系统C、N循环过程影响。通过上述研究，得到以下主要结果： （1）草地生态系统总C储量为34.38 Mg ha-1，15、24和30年生樟子松人工林生态系统总C储量分别为43.56、60.45和66.59 Mg ha-1，7、11和15年生杨树人工林生态系统总C储量分别为34.54、48.26和78.77 Mg ha-1；与农田相比，退耕5年的杨树人工林生态系统总C库储量下降13%，而10年和15年杨树人工林分别增加了176%和5倍；随着人工林年龄的增加，地上植被生物量C库储量占生态系统总C库储量的比例逐渐增加，并主要分配在树干。草地生态系统总N库储量为2.54 Mg ha-1，15、24和30年生樟子松人工林生态系统总N库储量分别为1.96、2.10和2.19 Mg ha-1，7、11和15年生杨树人工林生态系统总N库储量分别为2.27、1.84和2.60 Mg ha-1；与农田相比，退耕5年的杨树人工林生态系统总N库储量下降32%，而10年和15年杨树人工林分别增加了47%和76%；农田和草地造林后生态系统N储量依然主要分配在土壤中。 （2）草地和农田造林后土壤C、N库储量的变化受多因子的影响，例如林龄、树种种类以及立地条件等。农田和草地造林初期，土壤C、N库储量表现出下降趋势，随着林龄的增加，土壤C、N储量逐渐恢复。草地营造樟子松人工林30年后，0–60 cm深度土壤C、N储量依然显著低于草地；与草地相比，15年生杨树人工林土壤C、N储量差异不显著。在立地条件较好的情况下，10年杨树人工林土壤C、N储量已显著高于农田；然而，在立地条件相对较差的情况下，15年杨树人工林土壤C、N储量仍然与农田相比差异不显著。 （3）土地利用变化能够强烈地改变土壤C、N循环过程。与草地或疏林草地相比，32年生樟子松人工林土壤C、N、P含量显著降低；土壤C、N矿化过程发生显著变化，并且受季节变化的影响；在不同季节，土壤微生物量碳含量、代谢熵（qCO2）、微生物熵（MBC/TOC）以及土壤酶活性等在不同土地利用条件下表现出规律不一致。同样，农田退耕杨树人工林能够显著影响土壤C、N矿化过程，土壤无机氮（铵态氮+硝态氮）含量，土壤微生物量碳含量以及土壤微生物活性。草地造林在一定程度上导致土壤质量下降。而农田造林有利于土壤质量改善，尤其在在立地条件较好情况下。 （4）N添加增加对沙地樟子松人工林地上和地下C、N元素含量影响不大；N添加1年后，仅林下植被C、N含量显著增加，高氮处理（N15）凋落物N含量显著增加。N添加抑制了沙地樟子松人工林凋落物的早期分解和N、P元素释放。5、6、8和9月份土壤无机N含量均随着N输入增加表现出一定程度的增加，然而，7月份N添加导致土壤无机N含量降低。N添加对土壤潜在N矿化速率影响不显著。7和8月份N添加影响土壤C矿化速率，而其它月份影响不显著。低氮处理（N5）有利于增加土壤微生物量碳含量，而高氮处理（N15）在一定程度上降低土壤微生物量碳含量。 （5）凋落物输入变化（凋落物添加和凋落物移出）在一定程度上改变了35年生沙地樟子松人工林生态系统C、N循环过程。凋落物移出（C0）增加了林下植被C含量，降低了树木叶片N含量。凋落物移出抑制了凋落物分解和P元素的释放，而增加了C元素的早期释放速率，对N元素释放过程影响不显著。凋落物输入变化对不同月份土壤无机N含量和土壤N矿化过程影响均不显著。仅在6月份凋落物移出显著抑制了土壤C矿化速率，其它月份差异均不显著。凋落物管理对土壤微生物量碳含量影响不显著。 以上研究结果表明，土地利用变化、N沉降和凋落物输入改变等能够影响半干旱地区沙地生态系统C、N储量和循环过程。尤其是土地利用变化强烈改变沙地生态系统C、N储量、分配格局和循环过程，并且受到多因子的影响。科尔沁沙地樟子松人工林生态系统C、N元素生物地球化学循环存在密切的耦合关系。今后有必要进一步结合3S技术、同位素技术、模型模拟以及分子生物学技术等，从微观-宏观不同尺度上，研究半干旱地区沙地生态系统C、N循环过程对全球变化的响应及其反馈机制。

P(AM/AMPS/NVP)降失水剂合成与耐温性能研究

采用自由基水溶液聚合法成功制备了丙烯酰胺(AM)/2-甲基-2-丙烯酰胺基丙磺酸(AMPS)/N-乙烯基吡咯烷酮(NVP)三元共聚耐温型降滤失剂,通过红外(FTIR)光谱和核磁C谱表征了共聚物的结构,通过元素分析考察了共聚物组成。热失重(TGA)表明,P(AM/AMPS/NVP)耐温性优于P(AM/AMPS)和P(AM),通过对三元共聚物的抗高温性和降失水性的研究,表明P(AM/AMPS/NVP)具有良好的耐温降滤失性能。

Efect of Nostoc muscorum Ag. on germination in vitro of Bremia lactucae sporangia in Lactuca sativa L. Regel

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