bluuebunny/crossref_metadata_2025 huggingface dataset:
From Single Nucleotide Polymorphism to Transcriptional Mechanism
Authors: Martini Sebastian , Nair Viji , Patel Sanjeevkumar R. , Eichinger Felix , Nelson Robert G. , Weil E. Jennifer , Pezzolesi Marcus G. , Krolewski Andrzej S. , Randolph Ann , Keller Benjamin J. , Werner Thomas , Kretzler Matthias
Published: February 2013

Genome-wide association studies have proven to be highly effective at defining relationships between single nucleotide polymorphisms (SNPs) and clinical phenotypes in complex diseases. Establishing a mechanistic link between a noncoding SNP and the clinical outcome is a significant hurdle in translating associations into biological insight. We demonstrate an approach to assess the functional context of a diabetic nephropathy (DN)-associated SNP located in the promoter region of the gene FRMD3. The approach integrates pathway analyses with transcriptional regulatory pattern-based promoter modeling and allows the identification of a transcriptional framework affected by the DN-associated SNP in the FRMD3 promoter. This framework provides a testable hypothesis for mechanisms of genomic variation and transcriptional regulation in the context of DN. Our model proposes a possible transcriptional link through which the polymorphism in the FRMD3 promoter could influence transcriptional regulation within the bone morphogenetic protein (BMP)-signaling pathway. These findings provide the rationale to interrogate the biological link between FRMD3 and the BMP pathway and serve as an example of functional genomics-based hypothesis generation.
Systemic Free Fatty Acid Disposal Into Very Low-Density Lipoprotein Triglycerides
Authors: Koutsari Christina , Mundi Manpreet S. , Ali Asem H. , Patterson Bruce W. , Jensen Michael D.
Published: February 2013

We measured the incorporation of systemic free fatty acids (FFA) into circulating very low-density lipoprotein triglycerides (VLDL-TGs) under postabsorptive, postprandial, and walking conditions in humans. Fifty-five men and 85 premenopausal women with BMI 18–24 (lean) and 27–36 kg/m2 (overweight/obese) received an intravenous bolus injection of [1,1,2,3,3-2H5]glycerol (to measure VLDL-TG kinetics) and either [1-14C]palmitate or [9,10-3H]palmitate to determine the proportion of systemic FFA that is converted to VLDL-TG. Experiments started at 0630 h after a 12-h overnight fast. In the postabsorptive protocol, participants rested and remained fasted until 1330 h. In the postprandial protocol, volunteers ingested frequent portions of a fat-free smoothie. In the walking protocol, participants walked on a treadmill for 5.5 h at ∼3× resting energy expenditure. Approximately 7% of circulating FFA was converted into VLDL-TG. VLDL-TG secretion rates (SRs) were not statistically different among protocols. Visceral fat mass was the only independent predictor of VLDL-TG secretion, explaining 33–57% of the variance. The small proportion of systemic FFA that is converted to VLDL-TG can confound the expected relationship between plasma FFA concentration and VLDL-TG SRs. Regulation of VLDL-TG secretion is complex in that, despite a broad spectrum of physiological FFA concentrations, VLDL-TG SRs did not vary based on different acute substrate availability.
All-Cause and Cardiovascular Mortality in Middle-Aged People With Type 2 Diabetes Compared With People Without Diabetes in a Large U.K. Primary Care Database
Authors: Taylor Kathryn S. , Heneghan Carl J. , Farmer Andrew J. , Fuller Alice M. , Adler Amanda I. , Aronson Jeffrey K. , Stevens Richard J.
Published: February 2013

OBJECTIVE

Middle-aged people with diabetes have been reported to have significantly higher risks of cardiovascular events than people without diabetes. However, recent falls in cardiovascular disease rates and more active management of risk factors may have abolished the increased risk. We aimed to provide an up-to-date assessment of the relative risks associated with type 2 diabetes of all-cause and cardiovascular mortality in middle-aged people in the U.K.

RESEARCH DESIGN AND METHODS

Using data from the General Practice Research Database, from 2004 to 2010, we conducted a cohort study of 87,098 people, 40–65 years of age at baseline, comparing 21,798 with type 2 diabetes and 65,300 without diabetes, matched on age, sex, and general practice. We produced hazard ratios (HRs) for mortality and compared rates of blood pressure testing, cholesterol monitoring, and use of aspirin, statins, and antihypertensive drugs.

RESULTS

People with type 2 diabetes, compared with people without diabetes, had a twofold increased risk of all-cause mortality (HR 2.07 [95% CI 1.95–2.20], adjusted for smoking) and a threefold increased risk of cardiovascular mortality (3.25 [2.87–3.68], adjusted for smoking). Women had a higher relative risk than men, and people <55 years of age had a higher relative risk than those >55 years of age. Monitoring and medication rates were higher in those with diabetes (all P < 0.001).

CONCLUSIONS

Despite efforts to manage risk factors, administer effective treatments, and develop new therapies, middle-aged people with type 2 diabetes remain at significantly increased risk of death.
Low Serum Cultured Adipose Tissue-Derived Stromal Cells Ameliorate Acute Kidney Injury in Rats
Authors: Katsuno Takayuki , Ozaki Takenori , Saka Yosuke , Furuhashi Kazuhiro , Kim Hangsoo , Yasuda Kaoru , Yamamoto Tokunori , Sato Waichi , Tsuboi Naotake , Mizuno Masashi , Ito Yasuhiko , Imai Enyu , Matsuo Seiichi , Maruyama Shoichi
Published: February 2013

Current studies suggest that mesenchymal stromal cells (MSCs) improve acute kidney injury (AKI) via paracrine/ endocrine effects. We established human adipose tissue-derived stromal cells (hASCs) cultured in low (2%) serum (hLASCs), which have great potential of tissue regeneration. The present study was performed to investigate the therapeutic effects of hLASCs on AKI and to clarify the mechanisms involved. In low serum, hASCs proliferated well, while human bone marrow-derived stromal cells (hBMSCs) did not. hLASCs secreted higher levels of hepatocyte growth factor (HGF) and vascular endothelial growth factor (VEGF) than did hASCs cultured in high (20%) serum (hHASCs) or hBMSCs cultured in high serum (hHBMSCs). AKI was induced in nude rats by folic acid, and hLASCs, hHASCs or control medium were administered into the renal subcapsules. hLASCs significantly attenuated acute renal damage, while hHASCs showed far less effect. Furthermore, interstitial fibrosis observed on day 14 was less pronounced in the hLASCs group. Cell tracking experiment showed no evidence of transdifferentiation. Intravenous injection of hLASCs or hHBMSCs or subcapsular injection of hHBMSCs did not ameliorate AKI. Concerning the mechanisms, our in vivo experiments showed that HGF knockdown by siRNA impaired the ability of hLASCs to protect the kidney from acute injury whereas VEGF knockdown did not. In conclusion, hLASCs, but not hHASCs or hHBMSCs, ameliorated AKI via paracrine effects, and HGF is one of the key mediators.
Perceptions of Authenticity of Cultural Events: A Host–Tourist Analysis
Authors: Brida Juan Gabriel , Disegna Marta , Osti Linda
Published: February 2013

Many cultural events are an adoption of past rituals and traditional customs created by destination managers in order to advance tourism development. However, to be successful, such cultural events need to be authentic and need the support of the local community and the capacity of the locals to identify themselves with what is staged. In this article, the authors analyze the perception of authenticity by tourists and local residents at Christmas Markets in Northern Italy. The main objectives of this article are to determine the level of authenticity perceived by visitors and to examine any differences between tourists and local residents. To do so, a logistic regression model was employed. The results show not only a difference between the two groups, but especially the need for local organizers to focus on the involvement of local residents in the organization of fringe events based on deeply rooted local customs. This will provide tourists with a broader experience of the local traditions and more opportunities to interact with local residents.
Special Issue on the Accelerating Clinical Trials and Outcomes Research (ACTOR) Conference
Authors: Lin Susan H.
Published: February 2013

This special issue of AJOT features papers from the Accelerating Clinical Trials and Outcomes Research (ACTOR) Conference, which took place December 1–2, 2011.
Phosphine‐Free Palladium‐Catalyzed Decarboxylative Coupling of Alkynylcarboxylic Acids with Aryl and Heteroaryl Halides
Authors: Reddy Police Vishnuvardhan , Srinivas Pottabathula , Annapurna Manne , Bhargava Suresh , Wagler Jorg , Mirzadeh Nedaossadat , Kantam Mannepalli Lakshmi
Published: February 2013

We herein report the design and development of a carboxyamido/carbene ligand and its Pd‐complex for the decarboxylative coupling of alkynylcarboxylic acids with aryl and heteroaryl halides to afford arylalkynes.
Use of a Semihollow‐Shaped Triethynylphosphane Ligand for Efficient Formation of Six‐ and Seven‐Membered Ring Ethers through Gold(I)‐Catalyzed Cyclization of Hydroxy‐Tethered Propargylic Esters
Authors: Ito Hideto , Harada Ayumi , Ohmiya Hirohisa , Sawamura Masaya
Published: February 2013

The formation of six‐ and seven‐membered ring ethers from hydroxy‐tethered propargylic esters was efficiently catalyzed by a cationic gold(I) complex with a semihollow‐shaped triethynylphosphane ligand. This gold catalysis showed a tolerance toward the reactions of primary, secondary, and tertiary alcohol substrates with various substitution patterns. A sterically congested 2,2,6,6‐tetraalkyl‐substituted tetrahydropyran derivative as well as 6,6‐ and 7,6‐fused bicyclic diethers were obtained in useful yields. In addition, the gold catalysis was applicable to the reaction of a sulfonamide‐tethered propargylic ester to give a piperidine derivative.
Using Conveniently Designed α‐Amino Ketones in Michael Reactions under Iminium Catalysis: Enantioselective Synthesis of γ‐Lactams and γ‐Amino‐δ‐keto Esters
Authors: Talavera Garazi , Reyes Efraím , Vicario Jose L. , Carrillo Luisa , Uria Uxue
Published: February 2013

The behaviour of aminoacetophenones as Michael donors in catalytic enantioselective Michael reactions with α,β‐unsaturated aldehydes under iminium activation has been studied. These compounds react with each other in the presence of catalytic amounts of a chiral secondary amine through a Michael/hemiaminal formation cascade process which proceeds with high yields and enantiocontrol. Elaboration of these adducts by oxidation allows the easy access to chiral disubstituted γ‐lactams and other synthetically useful chiral building blocks such as γ‐amino‐δ‐keto esters or β‐substituted δ‐oxoamides are accessible from the obtained adducts by simple transformations.
Room Temperature Palladium‐Catalyzed Decarboxylative Acyl/Aroylation using [Fe(III)(EDTA)(η2‐O2)]3− as Oxidant at Biological pH
Authors: Sharma Sugandha , Khan Imran A. , Saxena Anil K.
Published: February 2013

The purple‐coloured iron peroxo complex [Fe(III)EDTA(η2‐O2)]3− as a novel reagent system for Pd‐catalyzed decarboxylative ortho‐acylation of acetanilides with α‐oxocarboxylic acids at room temperature in aqueous media has been realized. This reaction provides an effective access to ortho‐acylacetanilides under mild conditions.
Asymmetric Price Transmission in Food Supply Chains: Impulse Response Analysis by Local Projections Applied to U.S. Broiler and Pork Prices
Authors: Kuiper W. Erno , Lansink Alfons G.J.M. Oude
Published: February 2013

In this article, the author's set out Jordà's (2005) method of local projections by which nonlinear/ asymmetric impulse responses can be computed without the need to specify and estimate the underlying nonlinear/asymmetric dynamic system. The method is used to compute price‐reaction functions that show how the prices of the different stages in a food supply chain dynamically respond to each other and whether or not these responses reveal any asymmetric patterns. Empirical applications for the U.S. pork‐meat and broiler‐composite chains illustrate the convenience of the method and reveal that in the pork chain asymmetric price transmission enables retailers (wholesalers) to increase their marketing margin vis‐à‐vis the wholesalers (farmers), whereas in the broiler sector the retailers face both temporary decreases and increases in their marketing margin as a consequence of asymmetric wholesale‐retail price transmission.
Stoichiometric modeling of oxidation of reduced inorganic sulfur compounds (Riscs) in Acidithiobacillus thiooxidans
Authors: Bobadilla Fazzini Roberto A. , Cortés Maria Paz , Padilla Leandro , Maturana Daniel , Budinich Marko , Maass Alejandro , Parada Pilar
Published: February 2013

The prokaryotic oxidation of reduced inorganic sulfur compounds (RISCs) is a topic of utmost importance from a biogeochemical and industrial perspective. Despite sulfur oxidizing bacterial activity is largely known, no quantitative approaches to biological RISCs oxidation have been made, gathering all the complex abiotic and enzymatic stoichiometry involved. Even though in the case of neutrophilic bacteria such as Paracoccus and Beggiatoa species the RISCs oxidation systems are well described, there is a lack of knowledge for acidophilic microorganisms. Here, we present the first experimentally validated stoichiometric model able to assess RISCs oxidation quantitatively in Acidithiobacillus thiooxidans (strain DSM 17318), the archetype of the sulfur oxidizing acidophilic chemolithoautotrophs. This model was built based on literature and genomic analysis, considering a widespread mix of formerly proposed RISCs oxidation models combined and evaluated experimentally. Thiosulfate partial oxidation by the Sox system (SoxABXYZ) was placed as central step of sulfur oxidation model, along with abiotic reactions. This model was coupled with a detailed stoichiometry of biomass production, providing accurate bacterial growth predictions. In silico deletion/inactivation highlights the role of sulfur dioxygenase as the main catalyzer and a moderate function of tetrathionate hydrolase in elemental sulfur catabolism, demonstrating that this model constitutes an advanced instrument for the optimization of At. thiooxidans biomass production with potential use in biohydrometallurgical and environmental applications. Biotechnol. Bioeng. 2013; 110: 2242–2251. © 2013 Wiley Periodicals, Inc.
A Dopamine Electrochemical Sensor Based on Molecularly Imprinted Poly(acrylamidophenylboronic acid) Film
Authors: Hong Shuangjin , Lee Lawrence Yoon Suk , So Ming‐Him , Wong Kwok‐Yin
Published: February 2013

Molecularly imprinted polymeric films were prepared on the surface of a gold electrode by reductive electrochemical co‐polymerization of 3‐acrylamidophenylboronic acid (AABA), acrylamide (as spacer monomer), and N,N′‐methylenebisacrylamide (as crosslinker monomer) in the presence of dopamine in water. The analytical determination of dopamine was investigated with this molecularly imprinted poly(AABA) film‐modified gold electrode using cyclic voltammetry, electrochemical quartz crystal balance, and differential pulse voltammetry. The covalent nature of dopamine‐boronic acid interaction as well as the negative charge on the molecularly imprinted polymeric film at physiological pH allowed excellent selectivity against ascorbic acid and other structurally similar interferents. The sensitivity of molecularly imprinted poly(AABA)‐modified electrode was further improved by depositing a thin layer of multiwalled carbon nanotubes on the gold electrode surface prior to electropolymerization. The increased surface area due to the presence of carbon nanotubes improved the dopamine sensor’s detection limit to ∼20 nM as determined by differential pulse voltammetry. A linear dependence of peak current in the differential pulse voltammograms was obtained over the dopamine concentration range from 50 nM to 2 µM.
High‐resolution estimate for the depositional duration of the Triassic Latemar Platform: A new magnetostratigraphy and magnetic susceptibility cyclostratigraphy from basinal sediments at Rio Sacuz, Italy
Authors: Spahn Z. P. , Kodama K. P. , Preto N.
Published: February 2013

A new magnetostratigraphy and magnetic susceptibility cyclostratigraphy from Middle Triassic basinal sediments at Rio Sacuz, northern Italy, suggests a depositional duration of ~1 myr for most of the 670 m carbonate Latemar Platform, giving a high‐resolution estimate for the duration for the Latemar's deposition. The new magnetostratigraphy from Rio Sacuz clarifies the ambiguities in a previous magnetostratigraphic study of the Latemar caused by lightning strike remagnetizations. Our Rio Sacuz study was unaffected by lightning. Using thermal demagnetization, we show a Normal‐Reversed‐Normal‐Reversed sequence at the Latemar‐correlated locality of Rio Sacuz. With a polarity interval duration of ~0.25–0.5 myr for the Middle Triassic, this gives a depositional duration of ~1–2 myr. Rock magnetic experiments show that the magnetic carrier is magnetite, suggesting a primary, depositional‐age remanence. Measurement of magnetic susceptibility at 1 m intervals from Rio Sacuz reveals eight short eccentricity cycles (~95–125 kyr) bundled into slightly more than two 405 kyr long eccentricity cycles indicating a more precise duration for the Rio Sacuz section of 0.8 to 1 myr. The shorter depositional duration required by this study forces a sub‐Milankovitch time scale of 1–2 kyr for the Latemar platform's meter‐scale rhythmic bedding and provides strong evidence for nonorbitally driven climate change in the Middle Triassic.
Convective self‐aggregation, cold pools, and domain size
Authors: Jeevanjee Nadir , Romps David M.
Published: February 2013

Convective self‐aggregation refers to a phenomenon in cloud‐resolving simulations wherein the atmosphere spontaneously develops a circulation with a convecting moist patch and a nonconvecting dry patch. All previous studies have found a sharp transition to aggregated convection when the domain size exceeds a critical threshold, typically in the range of 200–300 km. Here, we show that cold pools are responsible for this sharp transition. When cold pools are inhibited, self‐aggregation occurs at all domain sizes. In this case, the aggregation strength decreases smoothly as the domain size L is decreased below about 200–300 km. A streamfunction analysis reveals two distinct sources for the air subsiding into the dry‐patch boundary layer: a moist, shallow circulation and a dry, deep circulation. The deep circulation scales with L, whereas the shallow circulation does not. At small L, the shallow circulation dominates, thereby weakening the aggregation.
Large mineralogically distinct impact melt feature at Copernicus crater – Evidence for retention of compositional heterogeneity
Authors: Dhingra Deepak , Pieters Carle M. , Head James W. , Isaacson Peter J.
Published: February 2013

Despite several lines of evidence for efficient mixing of impact melt in complex craters, we document mineralogical heterogeneity in impact melt deposit on a scale of tens of kilometers on the Moon in the 96 km‐diameter Copernicus crater. This heterogeneity is in the form of a large, sinuous impact melt feature on the floor and northern wall that is spectrally distinct from melt in its immediate vicinity. This melt feature spanning >30 km in length and 0.5–5 km in width has relatively short‐wavelength, narrow ferrous absorption bands near ~900 nm and ~2000 nm indicating a more Mg‐rich pyroxene composition as compared to impact melt deposit in the vicinity which is relatively rich in Fe/Ca‐pyroxenes. This distinction provides evidence for the preservation of compositional heterogeneity in impact melt in complex craters on the Moon and documents an example of inefficient mixing of melt during the cratering process.
Modeling past and future surface mass balance of the Northern Patagonia Icefield
Authors: Schaefer M. , Machguth H. , Falvey M. , Casassa G.
Published: February 2013

Glaciers are strongly retreating and thinning in Patagonia. We present new inferences about the climatic situation and the surface mass balance on the Northern Patagonia Icefield in the past and the future using a combined modeling approach. The simulations are driven by NCAR/NCEP Reanalysis and ECHAM5 data, which were physically downscaled using the Weather Research and Forecasting regional climate model and simple sub‐grid parameterizations. The surface mass balance model was calibrated with geodetic mass balance data of three large non‐calving glaciers and with point mass balance measurements. An increase of accumulation on the Northern Patagonia Icefield was detected from 1990–2011 as compared to 1975–1990. Using geodetic mass balance data, calving losses from the Northern Patagonia Icefield could be inferred, which doubled in 2000–2009 as compared to 1975–2000. The 21st century projection of future mass balance of the Northern Patagonia Icefield shows a strong increase in ablation from 2050 and a reduction of solid precipitation from 2080, both due to higher temperatures. The total mass loss in the 21st century is estimated to be 592±50 Gt with strongly increasing rates towards the end of the century. The prediction of the future mass balance of the Northern Patagonia Icefield includes several additional sources of errors due to uncertainties in the prediction of future climate and due to possible variations in ice dynamics, which might modify the geometry of the icefield and change the rate of mass losses due to calving.
Constructing China's Roads as Works of Art: A Case Study of “Esthetic Greenway” Construction in the Shennongjia Region of China
Authors: Cheng B. , Lv Y. , Zhan Y. , Su D. , Cao S.
Published: February 2013

Sustainable development based on economic growth that is environmentally sound is increasingly essential. To achieve both ecological and social progress without detracting from China's primary economic objectives, China's Ministry of Communications has promoted the strategy of harmonious road systems, for which artistic principles are incorporated in the road's design to balance the needs of the environment with those of socioeconomic development without neglecting human esthetic needs. To illustrate the new strategy's impact, we examined a project that has been conducted following this approach in the Shennongjia region of China's Hubei Province since 2004. As in the use of ecological corridors, the new strategy emphasizes the need to decrease the impact of road construction on plant and animal habitats by emphasizing the protection of existing natural habitats and the use of local species for revegetation of the land surrounding the roads. However, it also emphasizes the need to improve traffic safety, promote local tourism and economic growth, and provide a demonstration to citizens (including bureaucrats) of the need for environmental protection both during and after road construction. After 6 years of monitoring, we found that the new strategy both satisfies the human desire for beauty and improves the road's harmony with nature and the surrounding visual landscape while promoting environmental conservation, ecotourism, traffic safety, socioeconomic development, and cultural values. This approach will help to guide future landscape design, planning, and management. Copyright © 2013 John Wiley & Sons, Ltd.
Comment on SESAM‐free mode‐locked semiconductor disk laser
Authors: Wilcox Keith G. , Tropper Anne C.
Published: February 2013

The authors of the recent paper titled “SESAM‐free mode‐locked semiconductor disk laser” [1] make the claim that Kerr lens mode‐locking has been observed in a SESAM free semiconductor disk laser. However, the data presented in the manuscript at best weakly support the central claim that this laser is mode‐locked and at worst are simply the characterisation of a continuous‐wave (CW) laser. The physical principles of mode‐locking are clearly defined in many text books as well as in the first paper reporting mode‐locking [2] and more recently the work of H. A. Haus [3]. When reporting a new mode‐locking technique for a particular class of laser, it is essential to pay detailed attention to the measured characteristics. It is also helpful to comment on the strength of the mode‐locking mechanism. In this case, for example, the effective Kerr lens could be calculated, or better, experimentally measured, to further support the central claim.
Rationalization of interpretation of uroflowmetry for a non‐caucasian (Indian) population: conceptual development and validation of volume‐normalized flow rate index
Authors: Agarwal Mayank Mohan , Patil ShivKumar , Roy Kishore , Bandawar Mayur , Choudhury Sunirmal , Mavuduru Ravimohan , Sharma Suresh K. , Mandal Arup K. , Singh Shrawan K.
Published: February 2013

Aims

We intended to define volume‐normalized flow rates (cQ; VQI) and to construct and validate uroflow (Q)–volume (V) nomograms in our Indian (non‐Caucasian) population.

Methods

Prospective observational study. Participants: Group A, male healthy volunteers 18–45 years without LUTS. Group B, men >18 years with LUTS (IPSS > 7; global QOL > 2). The participants voided in standing on normal‐to‐strong desire into digital gravimetric uroflowmeter. Data of <50 ml void and intermittent flow was discarded. Reference cQ calculated using (i) Von Garrelts equations (=Q/), (ii) cubic equations (=Q/). Bladder volume (BV) rather than voided volume (VV) was considered for Q–V relation (BV = VV + PVR). VQI derived from present data were compared with the reference‐VQI in terms of differences in area‐under‐curve of receiver operating characteristics. For comparing sensitivity, specificity and predictive values of study nomograms with Caucasian nomograms (Liverpool and Siroky), data of group‐A and ‐B were plotted on each nomogram and no. of observations above and below the cutoffs (defined as equivalent to −1 SD) manually counted.

Results

Total 542 voids of group‐A and 465 of group‐B included for final analysis. Q–V relation was best described as [Q ∝ BV2.4 ≅ BV2]. The derived VQI (=Q/ ≅ Q/) fared significantly superior to reference VQI with VV as denominator. Nomograms, constructed on Q ∝ BV2, were less sensitive but had higher specificity and positive predictive values compared to Caucasian nomograms.

Conclusions

Volume‐normalized flow‐rate index with BV as denominator (Q/) is has highly discriminative value in screening for voiding dysfunction. Population‐specific Q–BV nomograms are more specific and predictive than Caucasian Q–VV nomograms. Neurourol. Urodynam. 33:135–141, 2014. © 2013 Wiley Periodicals, Inc.
Influence of stereoregularity and linkage groups on chiral recognition of poly(phenylacetylene) derivatives bearing L‐leucine ethyl ester pendants as chiral stationary phases for HPLC
Authors: Zhang Chunhong , Liu Fangbin , Li Yufa , Shen Xiande , Xu Xiaodong , Sakai Ryosuke , Satoh Toshifumi , Kakuchi Toyoji , Okamoto Yoshio
Published: February 2013

Stereoregular poly(phenylacetylene) derivatives bearing L‐leucine ethyl ester pendants, poly‐1 and poly‐2a, were, respectively, synthesized by the polymerization of N‐(4‐ethynylphenylcarbamoyl)‐L‐leucine ethyl ester (1) and N‐(4‐ethynylphenyl‐carbonyl)‐L‐leucine ethyl ester (2) using Rh(nbd)BPh4 as a catalyst, while stereoirregular poly‐2b was synthesized by solid‐state thermal polymerization of 2. Their chiral recognition abilities for nine racemates were evaluated as chiral stationary phases (CSPs) for high‐performance liquid chromatography (HPLC) after coating them on silica gel. Both poly‐1 and poly‐2a with a helical conformation showed their characteristic recognition depending on coating solvents and the linkage groups between poly(phenylacetylene) and L‐leucine ethyl ester pendants. Poly‐2a with a shorter amide linkage showed higher chiral recognition than poly‐1 with a longer urea linkage. Coating solvents played an important role in the chiral recognition of both poly‐1 and poly‐2a due to the different conformation of the polymer main chains induced by the solvents. A few racemates were effectively resolved on the poly‐2a coated with a MeOH/CHCl3 (3/7, v/v) mixture. The separation factors for these racemates were comparable to those obtained on the very popular CSPs derived from polysaccharide phenylcarbamates. Stereoirregular poly‐2b exhibited much lower chiral recognition than the corresponding stereoregular, helical poly‐2a, suggesting that the regular structure of poly(phenylacetylene) main chains is essential to attain high chiral recognition. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Ring‐opening polymerization of lactones using binaphthyl‐diyl hydrogen phosphate as organocatalyst and resulting monosaccharide functionalization of polylactones
Authors: Miao Yong , Phuphuak Yupin , Rousseau Cyril , Bousquet Till , Mortreux André , Chirachanchai Suwabun , Zinck Philippe
Published: February 2013

Binaphthyl‐diyl hydrogen phosphate has been assessed for the first time as a catalyst for the ring‐opening polymerization of ε‐caprolactone (CL) and δ‐valerolactone (VL). In the presence of benzyl alcohol as coinitiator at 40–60 °C, the polymerization is quantitative and controlled both in terms of dispersity and of number‐average molecular weight corresponding to the monomer/initiator ratio. The use of a selectively protected D‐glucose derivative bearing the primary C6 hydroxyl group as initiator leads to the quantitative end‐functionalization of the polyesters in rather short reaction times (ca. 10 min at 60 °C for δ‐VL) with dispersities around 1.08–1.10. Methyl‐α‐D‐glucopyranoside has been used as a carbohydrate polyol initiator in bulk. The initiation efficiency is partial, leading to hydrophilic carbohydrates functionalized polylactones in a one‐step procedure. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Application of parylene for surface (polymer) enhanced laser desorption/ionization of synthetic polymers
Authors: Miksa Beata J. , Sochacki Marek , Sroka‐Bartnicka Anna , Uznański Paweł , Nosal Andrzej , Potrzebowski Marek J.
Published: February 2013

RATIONALE

Synthetic polymers of molecular masses up to a few kDa can be analyzed without the use of any matrix by direct laser desorption/ionization mass spectrometry (LDI‐MS). In this technique, the surface of the sample plate plays a crucial role, and many attempts have been made to understand the influence of the surface on the ease of desorption. Since this technique requires no tedious sample pretreatment, it is a promising method for the rapid characterization of various synthetic polymers.

METHODS

Parylene (poly(p‐xylylenes), PPX) was tested as a surface support for studying the molecular masses of biocompatible polymers: poly(ethylene glycol) (PEG), poly(L‐lactide) (PLLA), and poly(methyl methacrylate) (PMMA). The average molecular masses of the polymers were: PEG (600.0 Da and 3.5 kDa), PMMA (2.0 kDa), and PLLA (2.8 kDa).

RESULTS

LDI mass spectra of polymers deposited on parylene were enhanced by a factor of two over those obtained directly from the gold target plate.

CONCLUSIONS

Modification of the surface of the target plate by the addition of a PPX layer extended the functionality of LDI‐TOF MS, especially for the analysis of low‐mass compounds. The LDI analysis using the PPX‐coated target plate provided details of polymers including: end‐group, composition, monomer unit, and molecular mass distribution. The average molecular weights of four tested polymers on the gold target plate and the PPX support were unchanged, indicating that sample degradation was not occurring despite the high energy of the laser beam. The LDI investigations showed that the PPX support boosted ion yields by a factor of two compared with the gold target plate. Copyright © 2013 John Wiley & Sons, Ltd.
Penalized regression and risk prediction in genome‐wide association studies
Authors: Austin Erin , Pan Wei , Shen Xiaotong
Published: February 2013

An important task in personalized medicine is to predict disease risk based on a person's genome, e.g. on a large number of single‐nucleotide polymorphisms (SNPs). Genome‐wide association studies (GWAS) make SNP and phenotype data available to researchers. A critical question for researchers is how to best predict disease risk. Penalized regression equipped with variable selection, such as least absolute shrinkage and selection operator (LASSO) and smoothly clipped absolute deviation (SCAD), is deemed to be promising in this setting. However, the sparsity assumption taken by the LASSO, SCAD, and many other penalized regression techniques may not be applicable here: it is now hypothesized that many common diseases are associated with many SNPs with small to moderate effects. In this article, we use the GWAS data from the Wellcome Trust Case Control Consortium (WTCCC) to investigate the performance of various unpenalized and penalized regression approaches under true sparse or non‐sparse models. We find that in general penalized regression outperformed unpenalized regression; SCAD, truncatedL1−penalty (TLP), and LASSO performed best for sparse models, while elastic net regression was the winner, followed by ridge, TLP, and LASSO, for non‐sparse models. © 2013 Wiley Periodicals, Inc. Statistical Analysis and Data Mining, 2013
Tautomerism in nucleic acid bases and base pairs: a brief overview
Authors: Shukla Manoj K. , Leszczynski Jerzy
Published: February 2013

This article provides a brief overview of current status of studies on nucleic acid bases and base pairs tautomeric properties in the different environments. Applications of high‐level theoretical calculations have been found to be extremely useful in interpreting and enlightening complex experimental results. Actually, theory and experiments are complementary to each other and therefore it is not surprising that application of theoretical calculations were necessary to assign relatively higher energy tautomers of guanine in the gas phase. Inability to observe the stable tautomers in the laser‐desorbed guanine in the jet‐cooled beam demands more experiments and rigorous analysis. The usefulness of theoretical methods in the assignment of tautomeric forms of other bases and base pairs has also been discussed. Furthermore, we would like to state that recent surge in the high‐level computation of system such as nucleic acid bases and base pairs is only possible due to the advancement in state‐of‐the‐art computer hardware and computational algorithms. Afterward, it is not unexpected to assume that future investigations would utilize high‐level quantum chemistry calculation more rigorously in explaining complex experimental data as well as in revealing new phenomena not studied by experiments. WIREs Comput Mol Sci 2013, 3:637–649. doi: 10.1002/wcms.1145

This article is categorized under:

Structure and Mechanism > Molecular Structures

Structure and Mechanism > Computational Biochemistry and Biophysics
Infiltration into soils: Conceptual approaches and solutions
Authors: Assouline Shmuel
Published: February 2013

Key Points

historical retrospective of physical models of infiltration

Time Compression Approximation (TCA)

effects of special conditions on infiltration
The TeraFERMI terahertz source at the seeded FERMI free-electron-laser facility
Authors: Perucchi A. , Di Mitri S. , Penco G. , Allaria E. , Lupi S.
Published: February 2013

We describe the project for the construction of a terahertz (THz) beamline to be called TeraFERMI at the seeded FERMI free electron laser (FEL) facility in Trieste, Italy. We discuss topics as the underlying scientific case, the choice of the source, the expected performance, and THz beam propagation. Through electron beam dynamics simulations we show that the installation of the THz source in the beam dump section provides a new approach for compressing the electron bunch length without affecting FEL operation. Thanks to this further compression of the FEL electron bunch, the TeraFERMI facility is expected to provide THz pulses with energies up to the mJ range during normal FEL operation.
Potential energy curves for the interaction of Ag($\mathbf {5}{\bm s}$5s) and Ag($\mathbf {5}{\bm p}$5p) with noble gas atoms
Authors: Loreau J. , Sadeghpour H. R. , Dalgarno A.
Published: February 2013

We investigate the interaction of ground and excited states of a silver atom with noble gases (NG), including helium. Born-Oppenheimer potential energy curves are calculated with quantum chemistry methods and spin-orbit effects in the excited states are included by assuming a spin-orbit splitting independent of the internuclear distance. We compare our results with experimentally available spectroscopic data, as well as with previous calculations. Because of strong spin-orbit interactions, excited Ag-NG potential energy curves cannot be fitted to Morse-like potentials. We find that the labeling of the observed vibrational levels has to be shifted by one unit.
Robotics, biological grounding and the Fregean tradition
Authors: Hooijmans Marti , Keijzer Fred
Published: February 2013

Dynamic, embodied and situated cognition set up organism-environment interaction — agency for short — as the core of cognitive systems. Robotics became an important way to study this behavioral kernel of cognition. In this paper, we discuss the implications of what we call the biological grounding problem for robotic studies: Natural and artificial agents are hugely different and it will be necessary to articulate what must be replicated by artificial agents such as robots. Interestingly, once this issue is explicitly raised, it seems that a full replication of biological features is required for cognition itself to be plausibly cast as a biological phenomenon. Several issues come to the fore once one takes this implication seriously. Why does a full biological interpretation of cognition remain so controversial? How does this impact the relevance of robotics for the study of cognition? We try to articulate and ease the various tensions that arise from this biological scenario.
Mechanism is not enough
Authors: Bickhard Mark H.
Published: February 2013

I will argue that mechanism is not sufficient to capture representation, thus cognition. More generally, mechanism is not sufficient to capture normativity of any sort. I will also outline a model of emergent normativity, representational normativity in particular, and show how it transcends these limitations of mechanism. To begin, I will address some illustrative attempts to model representation within mechanistically naturalistic frameworks, first rather generally, and then in the cases of the models of Fodor and Millikan.
Whence the autonomy?
Authors: Kravchenko Alexander V.
Published: February 2013

The internalist (computational) account of cognition is questioned and the explanatory power of the biology of cognition in resolving epistemological issues is emphasized. It is argued that, far from being an autonomous activity within the brains of cognizers which generates input/output capacity and can be auditioned by the Turing Test, cognition is a function of living systems as unities of interactions that exist in an environment in structural coupling. Therefore, it is distributed.
Challenges of safe medication practice in paediatric care – a nursing perspective
Authors: Star Kristina , Nordin Karin , Pöder Ulrika , Edwards I Ralph
Published: February 2013

Aim

To explore nurses’ experiences of handling medications in paediatric clinical practice, with a focus on factors that hinder and facilitate safe medication practices.

Methods

Twenty nurses (registered nurses) from four paediatric wards at two hospitals in Sweden were interviewed in focus groups. The interviews were analysed using content analysis.

Results

Six themes emerged from the analysed interviews: the complexity specific for nurses working on paediatric wards is a hindrance to safe medication practices; nurses’ concerns about medication errors cause a considerable psychological burden; the individual nurse works hard for safe medication practices and values support from other nurse colleagues; circumstances out of the ordinary are perceived as critical challenges for maintaining patient safety; nurses value clear instructions, guidelines and routines, but these are often missing, variable or changeable; management, other medical professionals, the pharmacy, the pharmaceutical industry and informatics support need to respond to the requirements of the nurses’ working situations to improve safe medication practices.

Conclusion

Weaknesses were apparent in the long chain of the medication‐delivery process. A joint effort by different professions involved in that delivery process, and a nationwide collaboration between hospitals is recommended to increase safe medication practices in paediatric care.
Atypical pilar leiomyomatosis: an unusual presentation of multiple atypical cutaneous leiomyomas
Authors: Cook Deborah L. , Pugliano‐Mauro Melissa A. , Schultz Zea L.
Published: February 2013

Cutaneous leiomyomas are relatively common benign smooth muscle tumors that may arise as solitary or multiple lesions. Rare forms with cytologic atypia, and features similar to symplastic leiomyomas of the uterus, have been described. We report a case of multiple cutaneous atypical leiomyomas occurring in a 43‐year‐old man with long history of lesions of the right lower leg and a family history of leiomyomatosis. Twenty of the lesions were excised due to pain and were examined histopathologically. All the lesions exhibited features described in atypical leiomyomas of the skin including increased cellularity, nuclear atypia and pleomorphism, and low mitotic activity. The biologic potential of cutaneous atypical leiomyomas is uncertain. Only a few case reports exist in the literature with the majority occurring as solitary lesions. Most of the reported atypical leiomyomas have behaved in a benign fashion. However, a rare account of transformation to leiomyosarcoma emphasizes the need for long‐term follow up of these patients. Herein, we describe a case of multiple atypical cutaneous leiomyomas arising in the setting of familial leiomyomatosis.
Contrast‐induced acute kidney injury following PCI
Authors: Tehrani Shana , Laing Chris , Yellon Derek M. , Hausenloy Derek J.
Published: February 2013

Background

Coronary revascularization using percutaneous coronary intervention (PCI) is one of the major treatments for patients with stable coronary artery disease, with approximately 1.5 million patients undergoing PCI in the United States and Europe every year. An important neglected complication of PCI is contrast‐induced acute kidney injury (CI‐AKI).

Design

In this article, we review the definition, pathogenesis and management of CI‐AKI and highlight potential therapeutic options for preventing CI‐AKI in post‐PCI patients.

Results

CI‐AKI is an important but underdiagnosed complication of PCI that is associated with increased in‐hospital morbidity and mortality. Patients with pre‐existing renal impairment and diabetes are particularly susceptible to this complication post‐PCI. Optimization of the patients' circulating volume remains the mainstay for preventing CI‐AKI, although the best strategy for achieving this is still controversial.

Conclusion

Following PCI, CI‐AKI is an overlooked complication which is associated with significant morbidity and mortality. In this article, we review the pathophysiology of CI‐AKI in patients undergoing PCI and discuss the potential therapeutic options for preventing it.
Mammary ductal elongation and myoepithelial migration are regulated by the composition of the extracellular matrix
Authors: NGUYEN‐NGOC K.‐V. , EWALD A.J.
Published: February 2013

Mammary branching morphogenesis occurs over a period of weeks deep inside an adipocyte‐rich stroma. The adipocytes contain light‐scattering lipid droplets that limit the depth of penetration of visible light. Organotypic culture methods were developed to enable high‐resolution optical monitoring of branching morphogenesis ex vivo. A challenge has been to identify the best culture conditions to model specific developmental events. We recently demonstrated that collagen I induces protrusive invasion in both normal and neoplastic mammary epithelium. In this study, we observed that the abundance of collagen I fibrils correlated strongly with invasive behaviour, even when the collagen I concentration was identical. We found that the extent of fibril assembly was experimentally manipulable by varying the incubation time at 4°C following pH neutralization. We next tested the capacity of collagen I fibrils to induce invasive behaviour when presented in combination with basement membrane proteins (Matrigel). We found that epithelial organoids in mixed gels of collagen I and basement membrane proteins exhibited more extensive branching morphogenesis but did not initiate protrusions into the matrix. Organoids in pure Matrigel produced many small epithelial buds that were bare of myoepithelial cells. Surprisingly, organoids in mixed gels of collagen I and Matrigel produced fewer epithelial buds, the buds elongated further, and the elongating buds remained covered by myoepithelial cells. Our mixed gels therefore provide a more physiologically accurate model of mammary branching morphogenesis. Our results also suggest that changes in the composition of the extracellular matrix could induce migration of epithelial cells past myoepithelial coverage.
Long‐Term Trends in Relative Earnings Mobility
Authors: Schiller Bradley R. , Mukhopadhyay Sankar
Published: February 2013

Objectives

The extent of individual mobility across hierarchical ranks of the income distribution is a critical factor in interpreting the sociopolitical significance of well‐documented increases in cross‐sectional inequality. The objective of this study is to replicate two earlier investigations of mobility, allowing one to discern trends in mobility rates and patterns.

Methods

Mobility was measured using data from NLSY79 (where NLSY is National Longitudinal Survey of Youth) for the years 1989–2004.

Results

Results show that hierarchical (relative) mobility has remained substantial and pervasive from the 1970s through the 1990s for male workers, with no evidence of any attenuation. In view of the increased distance between (absolute) income ranks, this observation is both surprising and reassuring.

Conclusion

Despite substantial increase in cross‐sectional inequality, long‐term mobility rates have not changed since the 1960s.
Active Control of a Reduced Scale Riser Undergoing Vortex-Induced Vibrations
Authors: Fortaleza Eugenio
Published: February 2013

This article concerns the use of an active control applied to a reduced scale riser undergoing vortex-induced vibrations (VIV). The control system relies upon the fact that a flexible structure undergoing VIV oscillates at frequencies corresponding to the structure resonant modes. These experiments were carried out in a recirculating water channel at IFP. For control design, the structure dynamic behavior is approximated by the dynamic behavior of its most excited mode. This is achieved through modal analysis and leads to a simple linear second order system. Its input is a displacement at the structure top end; its output is the structure displacement of a point away from the top end. The input is computed to attenuate the vibrations associated the most excited mode. This control strategy has been tested on a reduced scale experiment. These results are shown to agree with numerical results obtained on a phenomenological model. Both suggest a VIV reduction about 30%.