bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of perioperative complications on clinical outcome scores in lumbar fusion surgery
Authors: Lambat Manish P. , Glassman Steven D. , Carreon Leah Y.
Published: January 2013

Object

Although lumbar fusion is effective in well-selected patients, it is not without complications associated with short-term morbidity. There is a paucity of literature on the effect of these complications on long-term clinical outcomes. The purpose of this study was to determine whether perioperative complications—that is, those occurring within 30 days after surgery—alter the long-term clinical outcomes after lumbar fusion.

Methods

The authors retrospectively reviewed surgical and clinical databases for the period from 2001 to 2008 to identify patients who had undergone instrumented lumbar spinal fusion and had complete preoperative and 2-year postoperative outcome measures data. Outcome measures included the 36-Item Short-Form Health Survey (SF-36) Physical Component Summary, SF-36 Mental Component Summary, Oswestry Disability Index (ODI), and Numeric Rating Scales (0–10) for back and leg pain.

Three patient groups were created for comparison—one with major complications, one with only minor complications, and another with no complications—using propensity matching techniques based on demographics, baseline clinical outcome scores, and surgical characteristics. Preoperative and 2-year postoperative outcome scores in the groups were compared. One-way ANOVA was used to compare continuous variables, and the Fisher exact test was used to compare categorical variables between the groups. Significance was set at p < 0.001.

Results

In the database with 1144 patients, 81 had a major complication. Of these 81 patients, 78 were propensity matched to a similar group of patients with minor complications and another group with no complications. Comparison of the 3 groups revealed that 2-year postoperative outcomes were not statistically different for any of the measures. Overall ODI at 2 years was better in patients having no complications (39.6) or only minor complications (37.0) than in those having major complications (44.5), but this difference was not statistically significant (p = 0.074). The proportion of patients reaching a minimum clinically important difference (MCID) for ODI was statistically significantly smaller in the major complication group (31%) than in the minor complication (51%) and no complication groups (65%; p < 0.001).

Conclusions

A smaller proportion of patients achieved MCID for ODI 2 years after a major perioperative complication following lumbar fusion than after a minor complication or no complications.
Ovarian Cancer: In Search of Better Marker Systems Based on DNA Repair Defects
Authors: Varga Dominic , Deniz Miriam , Schwentner Lukas , Wiesmüller Lisa
Published: January 2013

Ovarian cancer is the fifth most common female cancer in the Western world, and the deadliest gynecological malignancy. The overall poor prognosis for ovarian cancer patients is a consequence of aggressive biological behavior and a lack of adequate diagnostic tools for early detection. In fact, approximately 70% of all patients with epithelial ovarian cancer are diagnosed at advanced tumor stages. These facts highlight a significant clinical need for reliable and accurate detection methods for ovarian cancer, especially for patients at high risk. Because CA125 has not achieved satisfactory sensitivity and specificity in detecting ovarian cancer, numerous efforts, including those based on single and combined molecule detection and “omics” approaches, have been made to identify new biomarkers. Intriguingly, more than 10% of all ovarian cancer cases are of familial origin. BRCA1 and BRCA2 germline mutations are the most common genetic defects underlying hereditary ovarian cancer, which is why ovarian cancer risk assessment in developed countries, aside from pedigree analysis, relies on genetic testing of BRCA1 and BRCA2. Because not only BRCA1 and BRCA2 but also other susceptibility genes are tightly linked with ovarian cancer-specific DNA repair defects, another possible approach for defining susceptibility might be patient cell-based functional testing, a concept for which support came from a recent case-control study. This principle would be applicable to risk assessment and the prediction of responsiveness to conventional regimens involving platinum-based drugs and targeted therapies involving poly (ADP-ribose) polymerase (PARP) inhibitors.
Overlapping ATP2C1 and ASTE1 Genes in Human Genome: Implications for SPCA1 Expression?
Authors: Micaroni Massimo , Malquori Lorenzo
Published: January 2013

The ATP2C1 gene encodes for the secretory pathway calcium (Ca2+)-ATPase pump (SPCA1), which localizes along the secretory pathway, mainly in the trans-Golgi. The loss of one ATP2C1 allele causes Hailey-Hailey disease in humans but not mice. Examining differences in genomic organization between mouse and human we speculate that the overlap between ATP2C1 and ASTE1 genes only in humans could explain this different response to ATP2C1 dysregulation. We propose that ASTE1, overlapping with ATP2C1 in humans, affects alternative splicing, and potentially protein expression of the latter. If dysregulated, the composition of the SPCA1 isoform pool could diverge from the physiological status, affecting cytosolic Ca2+-signaling, and in turn perturbing cell division, leading to cell death or to neoplastic transformation.
Les matériels pédagogiques pour la formation linguistique de base des résidents étrangers adultes en France : supports identitaires d'un groupe professionnel ?
Authors: Coulbaut-Lazzarini Amélie , Bergere Amandine
Published: January 2013

Résumé Le secteur professionnel de la formation linguistique de base pour adultes en France demeure flou et complexe. Cet article veut montrer que les matériels pédagogiques utilisés par les formateurs reflètent une unité, voire une identité de ce qu’il convient alors d’appeler un groupe professionnel. Basé sur les travaux en sciences du langage, mais surtout sur les travaux récents en sociologie des groupes professionnels, cet article analyse les matériels pédagogiques produits et utilisés par les formateurs. Il s’intéresse particulièrement aux principes pédagogiques et aux exercices contenus dans ces matériels, ainsi qu’à l’adéquation ou non des uns aux autres, représentatifs des tensions du secteur.
A General Approach for Controlling Transcription and Probing Epigenetic Mechanisms: Application to the Cd4 Locus
Authors: Wan Mimi , Kaundal Ravinder , Huang Haichang , Zhao Jiugang , Yang Xiaojun , Chaiyachati Barbara H. , Li Sicong , Chi Tian
Published: January 2013

Synthetic regulatory proteins such as tetracycline (tet)-controlled transcription factors are potentially useful for repression as well as ectopic activation of endogenous genes and also for probing their regulatory mechanisms, which would offer a versatile genetic tool advantageous over conventional gene targeting methods. In this study, we provide evidence supporting this concept using Cd4 as a model. CD4 is expressed in double-positive and CD4 cells but irreversibly silenced in CD8 cells. The silencing is mediated by heterochromatin established during CD8 lineage development via transient action of the Cd4 silencer; once established, the heterochromatin becomes self-perpetuating independently of the Cd4 silencer. Using a tet-sensitive Cd4 allele harboring a removable Cd4 silencer, we found that a tet-controlled repressor recapitulated the phenotype of Cd4-deficient mice, inhibited Cd4 expression in a reversible and dose-dependent manner, and could surprisingly replace the Cd4 silencer to induce irreversible Cd4 silencing in CD8 cells, thus suggesting the Cd4 silencer is not the (only) determinant of heterochromatin formation. In contrast, a tet-controlled activator reversibly disrupted Cd4 silencing in CD8 cells. The Cd4 silencer impeded this disruption but was not essential for its reversal, which revealed a continuous role of the silencer in mature CD8 cells while exposing a remarkable intrinsic self-regenerative ability of heterochromatin after forced disruption. These data demonstrate an effective approach for gene manipulation and provide insights into the epigenetic Cd4 regulatory mechanisms that are otherwise difficult to obtain.
HLA Class II Molecules Influence Susceptibility versus Protection in Inflammatory Diseases by Determining the Cytokine Profile
Authors: Mangalam Ashutosh K. , Taneja Veena , David Chella S.
Published: January 2013

The MHC in humans encodes the most polymorphic genes, the HLA genes, which are critical for the immune system to clear infection. This can be attributed to strong selection pressure as populations moved to different parts of the world and encountered new kinds of infections, leading to new HLA class II alleles. HLA genes also have the highest relative risk for autoimmune diseases. Three haplotypes, that is, HLA-DR2DQ6, DR4DQ8, and DR3DQ2, account for HLA association with most autoimmune diseases. We hypothesize that these haplotypes, along with their multiple subtypes, have survived bottlenecks of infectious episodes in human history because of their ability to present pathogenic peptides to activate T cells that secrete cytokines to clear infections. Unfortunately, they also present self-peptides/mimics to activate autoreactive T cells secreting proinflammatory cytokines that cause autoimmune diseases.
Surficial geology of the eastern Gulf of Maine and Bay of Fundy
Authors: Fader G B , King L H , Maclean B
Published: January 2013

This study is based on the interpretation of echogram profiles, high resolution seismic reflection records, bottom dredge and grab samples, piston cores, bottom photographs, and adjacent land geology. The report is accompanied by Map 4011-G prepared at a scale of
1 : 300 000. Five sedimentary surficial units occur within the map-area and are continuous from the adjacent Scotian Shelf. The surficial sediments in the Gulf of Maine are mostly relict while those in the Bay of Fundy are presently undergoing change. The distribution and stratigraphic relationships
of the surficial units were controlled to a large extent by late and post- glacio-isostatic and glacio-eustatic fluctuations.
Numerical Boundary Conditions for Specular Reflection in a Level-Sets-Based Wavefront Propagation Method
Authors: Martinelli Sheri L.
Published: January 2013

We study the simulation of specular reflection in a level set method implementation for wavefront propagation in high frequency acoustics using WENO spatial operators. To implement WENO efficiently and maintain convergence rate, a rectangular grid is used over the physical space. When the physical domain does not conform to the rectangular grid, appropriate boundary conditions to represent reflection must be derived to apply at grid locations that are not coincident with the reflecting boundary. A related problem is the extraction of the normal vectors to the boundary, which are required to formulate the reflection condition. A separate level set method is applied to pre-compute the boundary normals which are then stored for use in the wavefront method. Two approaches to handling the reflection boundary condition are proposed and studied: one uses an approximation to the boundary location, and the other uses a local reflection principle. The second method is shown to produce superior results.
Aerosol indirect effect on warm clouds over South-East Atlantic, from co-located MODIS and CALIPSO observations
Authors: Costantino L. , Bréon F.-M.
Published: January 2013

Abstract. In this study, we provide a comprehensive analysis of aerosol interaction with warm boundary layer clouds over the South-East Atlantic. We use aerosol and cloud parameters derived from MODIS observations, together with co-located CALIPSO estimates of the layer altitudes, to derive statistical relationships between aerosol concentration and cloud properties. The CALIPSO products are used to differentiate between cases of mixed cloud-aerosol layers from cases where the aerosol is located well-above the cloud top. This technique allows us to obtain more reliable estimates of the aerosol indirect effect than from simple relationships based on vertically integrated measurements of aerosol and cloud properties. Indeed, it permits us to somewhat distinguish the effects of aerosol and meteorology on the clouds, although it is not possible to fully ascertain the relative contribution of each on the derived statistics. Consistently with the results from previous studies, our statistics clearly show that aerosol affects cloud microphysics, decreasing the Cloud Droplet Radius (CDR). The same data indicate a concomitant strong decrease in cloud Liquid Water Path (LWP), which is inconsistent with the hypothesis of aerosol inhibition of precipitation (Albrecht, 1989). We hypothesise that the observed reduction in LWP is the consequence of dry air entrainment at cloud top. The combined effect of CDR decrease and LWP decrease leads to rather small sensitivity of the Cloud Optical Thickness (COT) to an increase in aerosol concentration. The analysis of MODIS-CALIPSO coincidences also evidences an aerosol enhancement of low cloud cover. Surprisingly, the Cloud Fraction (CLF) response to aerosol invigoration is much stronger when (absorbing) particles are located above cloud top than in cases of physical interaction. This result suggests a relevant aerosol radiative effect on low cloud occurrence: absorbing particles above the cloud top may heat the corresponding atmosphere layer, decrease the vertical temperature gradient, increase the low tropospheric stability and provide favourable conditions for low cloud formation. We also analyse the impact of anthropogenic aerosols on precipitation, through the statistical analysis of CDR-COT co-variations. A COT value of 10 is found to be the threshold beyond which precipitation is mostly formed, in both clean and polluted environments. For larger COT, polluted clouds show evidence of precipitation suppression. Results suggest the presence of two competing mechanisms governing LWP response to aerosol invigoration: a drying effect due to aerosol enhanced entrainment of dry air at cloud top (predominant for optically thin clouds) and a moistening effect due to aerosol inhibition of precipitation (predominant for optically thick clouds).
The Collection 6 MODIS aerosol products over land and ocean
Authors: Levy R. C. , Mattoo S. , Munchak L. A. , Remer L. A. , Sayer A. M. , Hsu N. C.
Published: January 2013

Abstract. The twin Moderate Imaging resolution Spectroradiometer (MODIS) sensors have been flying on Terra since 2000 and Aqua since 2002, creating an incredible dataset of global Earth observations. Here, we introduce the Collection 6 (C6) algorithm to retrieve aerosol optical depth (AOD) and aerosol size parameters from MODIS-observed spectral reflectance. While not a major overhaul from the previous Collection 5 (C5) version, there are enough changes that there is significant impact on the products and their interpretation. The C6 algorithm is comprised of three sub-algorithms for retrieving aerosol properties (1) over ocean (dark in visible and near-IR wavelengths), (2) over vegetated/dark-soiled land (dark in the visible) and (3) over desert/arid land (bright in the visible). Here, we focus on the changes to both "dark target" algorithms (#1 and #2; DT-ocean and DT-land). Affecting both DT algorithms, we have updated assumptions for central wavelengths, Rayleigh optical depths and gas (H2O, O3, CO2, etc.) absorption corrections, and relaxed the solar zenith angle limit (up to ≤ 84°) to increase pole-ward coverage. For DT-land, we have updated the cloud mask to allow heavy smoke retrievals, fine-tuned the assignments for aerosol type as function of season/location, corrected bugs in the Quality Assurance (QA) logic, and added diagnostic parameters such topographic altitude. For DT-ocean, improvements include a revised cloud mask for thin-cirrus detection, inclusion of wind speed dependence in the retrieval, updates to logic of QA Confidence flag (QAC) assignment, and additions of important diagnostic information. All together, the changes to the DT algorithms result in reduced global AOD (by 0.02) over ocean and increased AOD (by 0.01) over land, along with some changes in spatial coverage. Preliminary validation shows that compared to surface-based sunphotometer data, the C6 DT-products should compare at least as well as those from C5. However, at the same time as we have introduced algorithm changes, we have also been accounting for such "upstream" changes including new instrument calibration, revised land/sea masking and changed cloud masking that has resulted in changes to the coverage and global statistics of the retrieved AOD. To satisfy users' desires for more complete global aerosol coverage, C6 will include a merged DT/DB product over semi-arid land surfaces. In addition to changes to aerosol retrieval, C6 will include diagnostic information about clouds in the aerosol field, such as an aerosol "cloud mask" at 500 m resolution, and products that describe the "distance to the nearest cloud" from clear pixels. Finally, responding to the needs of the air quality community, in addition to the standard 10 km product, C6 will include a global (DT-land and DT-ocean) aerosol product at 3 km resolution.
Dynamics of a two-fault system with viscoelastic coupling
Authors: Amendola A. , Dragoni M.
Published: January 2013

Abstract. A fault system made of two segments or asperities subject to a constant strain rate is considered. The fault is modelled as a discrete dynamical system made of two blocks coupled by a Maxwell spring dashpot element and pulled at constant velocity on a rough plane. The long-term behaviour of the fault is studied by calculating the orbits of the system in the phase space. The model shows the role of viscoelastic relaxation in the Earth's crust in controlling the occurrence times of earthquakes. If a viscoelastic coupling is present, earthquakes are anticipated or delayed with respect to the elastic case. The limit cycles made of two alternate asperity failures, which are observed in the case of purely elastic coupling, are no longer produced. The model is applied to the 1964 Alaska earthquake, which was the effect of the failure of two asperities and for which a remarkable post-seismic relaxation has been observed in the subsequent decades. In such a fault system, viscoelastic coupling of the asperities appears to have a great influence on the occurrence times of earthquakes.
Soil amendment with Aerva javanica (Burm. F.) Juss. ex Schult. in the control of root rot fungi of cowpea [Vigna unguiculata (L.) Walp.] and mung bean [Vigna radiata (L.)]
Authors: Ikram Naheed , Dawar Shahnaz
Published: January 2013

Root rot fungi cause severe losses of crop plants, so the present work was carried out to determine the effect of Aerva javanica parts powder on root infecting fungi of mung bean (Vigna radiata (L.) and cowpea (Vigna unguiculata (L.) Walp.). A. javanica parts (stem, leaves and flower) were used as soil amendments at 0.1, 1 and 5% to check the effectiveness on growth parameters. All the plant parts showed a significant reduction in root rot fungi like Fusarium spp., Rhizoctonia solani Kuhn, and Macrophomina phaseolina (Tassi) Goid. It was noted that germination percentage, fresh weight, leaf area and number of nodules were significantly higher and the inhibitory effect on root rot fungi increased when the soil was amended with A. javanica leaves at 1%. Thus, among all the treatments, A. javanica leaves at 1% were found to be the most effective against root rot fungi.
First record of the eucalyptus gall wasp, Leptocybe invasa Fisher and La Salle (Hymenoptera: Eulophidae), in Iraq
Authors: Hassan Feyroz R.
Published: January 2013

The eucalyptus gall wasp, Leptocybe invasa (Hymenoptera: Eulophidae), is a new genus and species recorded for the first time in Duhok city, Kurdistan region, Iraq. L. invasa makes galls on petioles, leaf midribs and young branches of Eucalyptus camaldulensis saplings and trees. This galling eventually can lead to heavily injured saplings. The average number of galls was 37.23 gall/branch, and major infestation was on leaf midribs with an average of 19.35 galls.
Weed infestation of spring common wheat (Triticum aestivum L.) grown in monoculture depending on the cover crop and weed control method
Authors: Gawęda Dorota , Kwiatkowski Cezary A.
Published: January 2013

The aim of this 3-year field study was to evaluate the effect of some stubble crops and in-crop weed control methods on the species composition, number and air-dry weight of weeds in a wheat crop grown in short-term monoculture. The study was conducted in the period 2009-2011 in the Uhrusk Experimental Farm on mixed rendzina soil classified as very good rye soil complex. It included various types of stubble crops ploughed in each year (control treatment without cover crop, white mustard, lacy phacelia, a mixture of legumes – narrow-leaf lupin + field pea) and methods of weed control in spring wheat (mechanical, mechanical and chemical, chemical weed control). On average during the study period, all stubble crops used reduced the air-dry weight of weds in the treatments with mechanical weed management relative to the control treatment. Irrespective of the weed control method, the number of weeds in the wheat crop was significantly lower only after the ploughing in of white mustard. Mechanical weed management proved to be less effective in reducing the number and dry weight of weeds compared to other weed control methods. The white mustard and legume mixture cover crops had a reducing effect on the number of weed species in relation to the treatment without cover crops. The highest floristic diversity of weed communities was found in the spring wheat crop in which only mechanical weeding alone was used.
Spectral Flow Cytometry
Authors: Nolan John P. , Condello Danilo
Published: January 2013

Interest in measuring the complete fluorescence spectra of individual cells in flow can be traced to the earliest days of flow cytometry. Recent advances in detectors, optics, and computation have made it possible to make full spectral measurements in the sub‐millisecond time frame in which flow cytometry measurements typically occur. This opens up new possibilities for applying spectroscopy to the analysis of individual cells. This unit reviews historical and contemporary approaches to spectral flow cytometry, as well as instrument design, calibration, and data analysis for spectral flow cytometry applications. Curr. Protoc. Cytom. 63:1.27.1‐1.27.13. © 2013 by John Wiley & Sons, Inc.
Heat Transfer Measurements for Nonboiling Two‐Phase Flow
Authors: Ghajar Afshin J. , Tang Clement C.
Published: January 2013

Two‐phase gas–liquid flow in a pipe is influenced by forces such as buoyancy, inertia, viscous, and surface tension, which result in various flow patterns being formed. The interaction of the two‐phase flow patterns with the inner pipe surface leads to the occurrence of nonuniform local heat transfer coefficient on the inner pipe surface. Due to the complex nature of two‐phase flow, the characterization of nonboiling gas–liquid flow heat transfer in a pipe at various inclination angles requires a functional experimental setup and proper experimental procedures. The functionality of the experimental setup and the experimental procedures to measure heat transfer systematically is discussed in this chapter. The measured heat transfer results indicate that the balance between the forces of buoyancy and inertia of two‐phase flow in a pipe, with varying inclinations, affects the local heat transfer coefficient on the inner pipe surface circumferentially. Two‐phase flow in a pipe with slight inclination angles has been observed with enhancement in heat transfer.
Wind Energy Measurements
Authors: Gregg Peter
Published: January 2013

An introduction to wind power concepts, fundamentals, and wind measurement. This chapter provides a brief overview of wind turbine technology and fundamentals, followed by a discussion of wind measurement, evaluation, and application as it relates to wind energy.
Corrosion Monitoring
Authors: Roberge Pierre R.
Published: January 2013

Corrosion monitoring refers to corrosion measurements performed under industrial or practical operating conditions. This requirement has led to the evolution of corrosion monitoring tools toward real‐time data acquisition, process control tools, knowledge based systems, and smart structures. Correct and effective corrosion monitoring strategies should be used as a proactive tool to assist with operating a plant or any other system more effectively, thereby prolonging its life and gaining optimum throughput. Fundamentally, four strategies have been discussed to an organization in its dealings with corrosion. Corrosion monitoring systems vary significantly in complexity, from simple coupon exposures or handheld data loggers to fully integrated plant process surveillance units with remote data access and data management capabilities. Numerous real‐time corrosion monitoring programs in diverse branches of industry have revealed that the severity of corrosion damage is rarely uniform with time. Rather, serious corrosion damage is usually sustained in time frames where operational parameters have suffered upsets. These undesirable operational windows can only be identified with the real‐time monitoring approach. An example of a widely available technique is linear polarization resistance, which many commercial monitoring systems use to measure corrosion rates.
Thermal Conductivity of Engineering Materials
Authors: Blumm Juergen
Published: January 2013

In many fields of modern engineering, knowledge of the thermophysical properties is becoming more and more important. Development of state‐of‐the‐art products such as cars, computers, space craft or modern production machines would not be possible without understanding and optimization of the heat transfer within parts under thermal load. This requires understanding of the theoretical background and the material properties. Presented in this chapter is an introduction to the basic heat transfer equations. Additionally, the most important thermophysical properties such as thermal conductivity, thermal diffusivity and specific heat are explained. Measurement methods are mentioned together with their typical application ranges. Finally some measurement examples are given in the field of polymers and ceramics.
Optical Methods for the Measurement of Thermal Conductivity
Authors: Bandaru Prabhakar R. , Aubain Max S.
Published: January 2013

To mitigate the issues associated with conventional methodologies for thermal conductivity measurements, such as those related to contact or thermal boundary resistance, noncontact, optical methods provide an alternate measurement technique. In this article, we briefly review the history of such optical methods and explain the principles involved in the thermoreflectance techniques as applied to silicon thin films.
Measurement Uncertainty
Authors: Clippinger David
Published: January 2013

Uncertainty is a property of a measurement. Its value allows us to quantify the expected level of dispersion in the quantity being measured. It is an important parameter for quantitatively determining the suitability of a measurement technique. Despite its frequent omission, the uncertainty of a measurement is actually important in all situations where a measured quantity must be trusted with a certain level of confidence. The two methods of evaluating or computing uncertainty have been presented here. These methods are consistent with each other while each possessing its own particular advantages. The ISO approach has the advantage of ease of application and flexibility. All uncertainties are treated identically, allowing for simplicity in approach. Further, the experimentalist may select an appropriate coverage factor or simply report the combined uncertainty and allow the end user of the measurement to determine the suitability of the measurement. The ASME approach requires that the sources of measurement uncertainty be sorted into systematic and random categories.
Iron‐Catalyzed CC Bond Cleavage and CN Bond Formation
Authors: Li Wenjuan , Zheng Xiaojian , Li Zhiping
Published: January 2013

A novel approach for CN bond formation was developed by iron‐catalyzed CC bond cleavage. Anilines and sulfonamides reacted smoothly with 2‐substituted 1,3‐diphenylpropane‐1,3‐diones to afford N‐alkylation products, in which the 1,3‐dicarbonyl group acts as a leaving group in the presence of an iron catalyst. The reversible CC bond cleavage plays a driving force to give the thermodynamically stable products. The method is complementary to the previous methods for CN bond formation.
Selective and Practical Oxidation of Sulfides to Diastereopure Sulfoxides: A Combined Experimental and Computational Investigation
Authors: Bottoni Andrea , Calvaresi Matteo , Ciogli Alessia , Cosimelli Barbara , Mazzeo Giuseppe , Pisani Laura , Severi Elda , Spinelli Domenico , Superchi Stefano
Published: January 2013

We describe an effective oxidation of diltiazem (DTZ)‐like molecules (a class of prochiral sulfides with potential pharmacological properties) using m‐chloroperbenzoic acid (MCPBA) as oxidant either in dichloromethane or methanol. An excellent diastereomeric excess of one sulfoxide has been observed “in the absence of any chiral auxiliary”. The stereochemistry of the two diastereomeric sulfoxides has been determined by TDDFT simulations of the experimental electronic circular dichroism (ECD) spectra. A computational DFT study of the reaction mechanism shows that the attack of MCPBA on the two sulfide enantiotopic faces affords two preliminary complexes M1 and M1′. M1 is more stable than M1′ by 3.3 and 3.5 kcal mol−1 in dichloromethane and methanol, respectively, and after equilibration its population must be dominant. Two diastereomeric pathways originate from M1 and M1′ and give two diastereomeric sulfoxides with R and S configurations at the new chiral sulfur, respectively. Since TS (the transition state originating from M1) is more stable than TS′ (the energy gap is 0.7 kcal mol−1 in dichloromethane or methanol), following the Curtin–Hammett principle, the favoured path is the pro‐R channel (M1→TS→M2) affording the (Rc,Rs)‐2a′ product species in agreement with the observed diastereoselectivity. The M1–M1′ and TS–TS′ energy gaps are actually determined by the difference in the hydrogen bond network that features the two species even if the approaching orientation of the two molecules is governed by the interactions between the π systems of oxidant and substrate aromatic rings. The diastereomeric ratio computed on the basis of the energy difference between TS and TS′ (0.7 kcal mol−1) is 63:37, which must be compared to the experimental value 9:1. When we consider free energy differences (2.4 kcal mol−1 in vacuum and 2.9 kcal mol−1 in solution) this theoretical ratio becomes 85:15 and 89:11, respectively, in excellent agreement with the experimental value 9:1.
Transparent low‐density polyethylene/starch nanocomposite films
Authors: Inceoglu Funda , Menceloglu Yusuf Ziya
Published: January 2013

Low‐density polyethylene (LDPE)/starch nanocomposite films were prepared by melt extrusion process. The first step includes the preparation of starch–clay nanocomposite by solution intercalation method. The resultant product was then melt mixed with the main matrix, which is LDPE. Maleic anhydride‐grafted polyethylene (MAgPE), produced by reactive extrusion, was used as a compatibilizer between starch and LDPE phases. The effects of using compatibilizer, clay, and plasticizers on physico‐mechanical properties were investigated. The results indicated that the initial intercalation reaction of clay layers with starch molecules, the conversion of starch into thermoplastic starch (TPS) by plasticizers, and using MAgPE as a compatibilizer provided uniform distribution of both starch particles and clay layers, without any need of alkyl ammonium treatment, in LDPE matrix. The nanocomposite films exhibited better tensile properties compared to clay‐free ones. In addition, the transparency of LDPE film did not significantly change in the presence of TPS and clay particles. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Preparation and application of triglyceride plasticizers for poly(vinyl chloride)
Authors: Ye Jinhua , Liu Shuzhen , Xiang Jun , Lei Jingxin , Zhou Changlin
Published: January 2013

A series of triglyceride plasticizers were prepared from glycerol, acetic acid, and benzoic acid through a two‐step reaction to develop potential uses of glycerol. The optimum reaction conditions were determined by the esterification of glycerol and acetic acid to produce glyceryl triacetate. When the molar ratio of glycerol to benzoic acid to acetic acid was 1:1:3.5, a novel plasticizer triglyceride mixture (GTM) was successfully synthesized; it had a good plasticizing effect on poly(vinyl chloride) (PVC). The elongation at break of PVC composites containing 80 phr GTM increased around 350%; the corresponding hardness (Shore D) and tensile strength decreased to around 35 D and 20 MPa, respectively. Moreover, the glass‐transition temperature (Tg) of PVC composites containing 40 phr GTM decreased to around 50°C. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Synthesis, characterization, and flocculation performance of anionic polyacrylamide P (AM‐AA‐AMPS)
Authors: Ma Jiangya , Zheng Huaili , Tan Mingzhuo , Liu Liwei , Chen Wei , Guan Qingqing , Zheng Xiaokai
Published: January 2013

In this study, a kind of anionic polyacrylamide (P(AM‐AA‐AMPS)) was synthesized using acrylamide (AM), acrylic acid (AA), and 2‐acrylamido‐2‐methyl propane sulfonic acid (AMPS) under ultraviolet (UV) irradiation. The conditions of the polymerization reaction such as monomer mass ratio, solution pH value, EDTA concentration and urea concentration were investigated by using the single factor approach and an L16 (45) orthogonal array. The structure and morphologies of the copolymer were determined by nuclear magnetic resonance spectrometer (NMR), infrared spectrometer (IR) and scanning electron microscope (SEM). The results show P(AM‐AA‐AMPS) with the intrinsic viscosity of 1.5 × 103 mL g−1 was synthesized at optimal conditions: mass ratio, m(AM) : m(AA) : m(AMPS) of 70 : 10 : 10, pH value of 9.0, EDTA concentration of 0.10% and urea concentration of 0.20%. In addition, P(AM‐AA‐AMPS) had better flocculation efficiency than commercial PAM in sludge dewatering experiment; the minimum filter cake moisture content could be reduced to 65.1%. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
In situ synthesis of nano silver on polyester using NaOH/Nano TiO2
Authors: Allahyarzadeh Vida , Montazer Majid , Nejad Nahid Hemmati , Samadi Nasrin
Published: January 2013

Alkali hydrolysis of polyester along with application of nano silver/nano TiO2 to produce hydrolyzed polyester fabric with antibacterial and self‐cleaning properties is a very interesting subject. In this article, a novel idea is introduced to achieve a polyester fabric with self‐cleaning and antibacterial properties with a good feeling handle in one step. The polyester fabric is hydrolyzed in alkali media to enhance the surface activity, improve nanoparticle absorption, and produce ethylene glycol for reducing silver nitrate into nano silver. XRD pattern confirms the presence of nanoparticles with crystal size of 10 nm on the fabric surface and FESEM pictures show the distribution of nanocomposite particles on the fiber surfaces with average size of 54 nm. The degradation of Methylene Blue under daylight irradiation confirms the photoactivity of nano TiO2 on the polyester fabric. Also, very good bactericidal efficiency is obtained against S. aureus and E. coli. Interestingly, the fabric tensile strength improves even with the action of alkali in surface hydrolysis of polyester. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Carbohydrate–PNA and Aptamer–PNA Conjugates for the Spatial Screening of Lectins and Lectin Assemblies
Authors: Scheibe Christian , Wedepohl Stefanie , Riese Sebastian B. , Dernedde Jens , Seitz Oliver
Published: January 2013

Nucleic acid architectures offer intriguing opportunities for the interrogation of structural properties of protein receptors. In this study, we performed a DNA‐programmed spatial screening to characterize two functionally distinct receptor systems: 1) structurally well‐defined Ricinus communis agglutinin (RCA120), and 2) rather ill‐defined assemblies of L‐selectin on nanoparticles and leukocytes. A robust synthesis route that allowed the attachment both of carbohydrate ligands—such as N‐acetyllactosamine (LacNAc), sialyl‐Lewis‐X (sLeX), and mannose—and of a DNA aptamer to PNAs was developed. A systematically assembled series of different PNA–DNA complexes served as multivalent scaffolds to control the spatial alignments of appended lectin ligands. The spatial screening of the binding sites of RCA120 was in agreement with the crystal structure analysis. The study revealed that two appropriately presented LacNAc ligands suffice to provide unprecedented RCA120 affinity (KD=4 μM). In addition, a potential secondary binding site was identified. Less dramatic binding enhancements were obtained when the more flexible L‐selectin assemblies were probed. This study involved the bivalent display both of the weak‐affinity sLeX ligand and of a high‐affinity DNA aptamer. Bivalent presentation led to rather modest (sixfold or less) enhancements of binding when the self‐assemblies were targeted against L‐selectin on gold nanoparticles. Spatial screening of L‐selectin on the surfaces of leukocytes showed higher affinity enhancements (25‐fold). This and the distance–activity relationships indicated that leukocytes permit dense clustering of L‐selectin.
Pitfalls associated with the use of current recommendations for fluoroscopy‐guided common femoral artery access
Authors: Yaganti Vamsee , Mejevoi Nicolai , Hasan Omar , Cohen Marc , Wasty Najam
Published: January 2013

Background

Vascular access complications remain the leading cause of morbidity after cardiac catheterization procedures. Fluoroscopy‐guided vascular access has been recommended to reduce these complications. However, the use of current recommendations still results in arterial access above the inferior epigastric artery (IEA) (high stick) or below the common femoral artery (CFA) bifurcation (low stick).

Objectives

The goal of our study was to evaluate the influence of patient characteristics like age, body mass index, and pelvic anatomy on current recommendations.

Methods

We prospectively collected clinical, anatomic, and angiographic data on 631 consecutive patients who underwent coronary and noncoronary procedures via CFA access. Anatomic location of IEA loop, CFA bifurcation, public tubercle (PT), and anterior superior iliac spine were identified in relationship to the femoral head Location of IEA loop was used as a surrogate for inguinal ligament (IL).

Results

Approximately 12% of patients had a low‐lying IEA loop (group B). These patients had a significantly higher BMI compared with patients with IEA loop above the centerline of femoral head (group A) (P = 0.018). The anatomic location of PT was below the lower border of femoral head significantly more frequently in group B compared to group A (P < 0.0001). Fifteen percent of patients had a high CFA bifurcation. On clinical follow‐up during index hospitalization, there was no significant difference between the two groups, in terms of complications including retroperitoneal hemorrhage, access site hematoma >5 cm, bleeding requiring transfusion or pseudoaneurysm.

Conclusions

Anatomic location of PT on fluoroscopy can be used as an additional surrogate to predict the location of IL. Patients with high BMI have a low lying IL, which may predispose them to “high sticks.” The location of IEA cannot be used as a surrogate for IL in all patients. © 2012 Wiley Periodicals, Inc.
Enhancement of Catalyst Performance in the Direct Propene Epoxidation: A Study into Gold–Titanium Synergy
Authors: Chen Jiaqi , Halin Sander J. A. , Pidko Evgeny A. , Verhoeven M. W. G. M. (Tiny) , Ferrandez Dulce M. Perez , Hensen Emiel J. M. , Schouten Jaap C. , Nijhuis T. Alexander
Published: January 2013

Enhanced productivity toward propene oxide in the direct propene epoxidation with hydrogen and oxygen over gold nanoparticles supported on titanium‐grafted silica was achieved by adjusting the gold–titanium synergy. Highly isolated titanium sites were obtained by lowering the titanium loading grafted on silica. The tetrahedrally coordinated titanium sites were found to be favorable for attaining small gold nanoparticles and thus a high dispersion of gold. The improved productivity of propene oxide can be attributed to the increased amount of the interfacial AuTi sites. The active hydroperoxy intermediate is competitively consumed by epoxidation and hydrogenation at the AuTi interface. A higher propene concentration is favorable for a lower water formation rate and a higher formation rate of propene oxide. Propene hydrogenation, if occurring, can be switched off by a small amount of carbon monoxide.
Theoretical Study of the Oxidation of Phenolates by the [Cu2O2(N,N′‐di‐tert‐butylethylenediamine)2]2+ Complex
Authors: Liu Yan Fang , Yu Jian Guo , Siegbahn Per E. M. , Blomberg Margareta R. A.
Published: January 2013

Experiments have shown that the μ‐η2:η2‐peroxodicopper(II) complex [Cu2O2(N,N′‐di‐tert‐butylethylenediamine)2]2+ rapidly oxidizes 2,4‐di‐tert‐butylphenolate into a mixture of catechol and quinone and that, at the extreme temperature of −120 °C, a bis‐μ‐oxodicopper(III)phenolate intermediate, labeled complex A, can be observed. These experimental results suggest a new mechanism of action for the dinuclear copper‐containing enzyme tyrosinase, involving an early OO bond‐cleavage step. However, whether phenolate binding occurs before or after the cleavage of the OO bond has not been possible to answer. In this study, hybrid density functional theory is used to study the synthetic reaction and, based on the calculated free‐energy profile, a mechanism is suggested for the entire phenolate‐oxidation reaction that agrees with the experimental observations. Most importantly, the calculations show that the very first step in the reaction is the cleavage of the OO bond in the peroxo complex and that, subsequently, the phenolate substrate coordinates to one of the copper ions in the bis‐μ‐oxodicopper(III) complex to yield the experimentally characterized phenolate intermediate (A). The oxidation of the phenolate substrate into a quinone then occurs in three steps: 1) CO bond formation, 2) coupled internal proton and electron transfer, and 3) electron transfer coupled to proton transfer from an external donor (acidic workup, experimentally). The first of these steps is rate limiting for the decay of complex A, with a calculated free‐energy barrier of 10.7 kcal mol−1 and a deuterium kinetic isotope effect of 0.90, which are in good agreement with the experimental values of 11.2 kcal mol−1 and 0.83(±0.09). The tert‐butyl substituents on both the phenol substrate and the copper ligands need to be included in the calculations to give a correct description of the reaction mechanism.
Collective Total Synthesis of Englerin A and B, Orientalol E and F, and Oxyphyllol: Application of the Organocatalytic [4+3] Cycloaddition Reaction
Authors: Wang Jie , Chen Shu‐Guang , Sun Bing‐Feng , Lin Guo‐Qiang , Shang Yong‐Jia
Published: January 2013

The concise collective total synthesis of englerin A and B, orientalol E and F, and oxyphyllol has been accomplished in 10–15 steps, with the total synthesis of orientalol E and oxyphyllol being achieved for the first time. The success obtained was enabled by the realization of the [4+3] cycloaddition reaction of 9 and 10. Other features of the synthesis include 1) the intramolecular Heck reaction to access the azulene core, 2) the epoxidation–SN2′ reduction sequence to access the allylic alcohol, 3) the efficient regioselective and stereoselective formal hydration of the bridging CC bond in the synthesis of englerins, and 4) the late‐stage chemo‐ and stereoselective CH oxidation in the synthesis of orientalol E. The total synthesis of these natural products has enabled the structural revision of oxyphyllol and established the absolute stereochemical features of the organocatalytic [4+3] cycloaddition reaction. The identification of 5 as the natural product oxyphyllol, the success in converting 5 to orientalol E, along with the fact that englerins and oxyphyllol were isolated from plants of the same genus Phyllanthus gives support to our proposed biosynthetic pathways. This work may enable detailed biological evaluations of these natural products and their analogues and derivatives, especially of their potential in the fight against renal cell carcinoma (RCC).
Syntheses and Characterization of New Vinyl‐Borylene Complexes by the Hydroboration of Alkynes with [(μ3‐BH)(Cp*RuCO)2(μ‐CO)Fe(CO)3]
Authors: Bose Shubhankar Kumar , Roy Dipak Kumar , Shankhari Pritam , Yuvaraj K. , Mondal Bijan , Sikder Amrita , Ghosh Sundargopal
Published: January 2013

Room temperature photolysis of a triply‐bridged borylene complex, [(μ3‐BH)(Cp*RuCO)2(μ‐CO)Fe(CO)3] (1 a; Cp*=C5Me5), in the presence of a series of alkynes, 1,2‐diphenylethyne, 1‐phenyl‐1‐propyne, and 2‐butyne led to the isolation of unprecedented vinyl‐borylene complexes (Z)‐[(Cp*RuCO)2(μ‐CO)B(CR)(CHR′)] (2: R, R′=Ph; 3: R=Me, R′=Ph; 4: R, R′=Me). This reaction permits a hydroboration of alkyne through an anti‐Markovnikov addition. In stark contrast, in the presence of phenylacetylene, a metallacarborane, closo‐[1,2‐(Cp*Ru)2(μ‐CO)2{Fe2(CO)5}‐4‐Ph‐4,5‐C2BH2] (5 a), is formed. A plausible mechanism has been proposed for the formation of vinyl‐borylene complexes, which is supported by density functional theory (DFT) methods. Furthermore, the calculated 11B NMR chemical shifts accurately reflect the experimentally measured shifts. All the new compounds have been characterized in solution by mass spectrometry and IR, 1H, 11B, and 13C NMR spectroscopies and the structural types were unequivocally established by crystallographic analysis of 2, 5 a, and 5 b.
Discovery of Pyridone‐Based Histone Deacetylase Inhibitors: Approaches for Metabolic Stability
Authors: Cho Misun , Choi Eunhyun , Yang Jee Sun , Lee Chulho , Seo Jeong Jea , Kim Beom Seok , Oh Soo Jin , Kim Hwan Mook , Lee Kiho , Park Song‐Kyu , Kwon Ho Jeong , Han Gyoonhee
Published: January 2013

Histone deacetylases (HDACs) are important enzymes in epigenetic regulation and are therapeutic targets for cancer. Most zinc‐dependent HDACs induce proliferation, dedifferentiation, and anti‐apoptotic effects in cancer cells. We designed and synthesized a new series of pyridone‐based HDAC inhibitors that have a pyridone ring in the core structure and a conjugated system with an olefin connecting the hydroxamic acid moiety. Consequently, most of the selected pyridone‐based HDAC inhibitors showed similar or higher inhibition profiles in addition to remarkable metabolic stability against hydrolysis relative to the corresponding lactam‐based HDAC inhibitors. Furthermore, the selectivity of the novel pyridine‐based compounds was evaluated across all of the HDAC isoforms. One of these compounds, (E)‐N‐hydroxy‐3‐{1‐[3‐(naphthalen‐2‐yl)propyl]‐2‐oxo‐1,2‐dihydropyridin‐3‐yl}acrylamide, exhibited the highest level of HDAC inhibition (IC50=0.07 μM), highly selective inhibition of class I HDAC1 and class II HDAC6 enzymes, metabolic stability in mouse liver microsomal studies, and effective growth inhibition of various cancer cell lines. Docking studies indicated that a long alkyl linker and bulky hydrophobic cap groups affect in vitro activities. Overall, the findings reported herein regarding pyridone‐based HDAC inhibitors can be used to guide future research efforts to develop new and effective anticancer therapeutics.