bluuebunny/crossref_metadata_2025_split huggingface dataset:
Breast Positioning during Mammography: Mistakes to be Avoided
Authors: Popli Manju Bala , Teotia Rahul , Narang Meenakshi , Krishna Hare 
Published: July 2014

Aims and Objectives Breast positioning is the key factor affecting a mammogram. If care is taken during positioning, it maximizes the amount of breast tissue being imaged, eliminates most of the artifacts, and increases sensitivity of the mammogram. This retrospective study was carried out in our department to assess correctness, and also the incorrectness of breast positioning, which need to be avoided to obtain an ideal mammogram. Material and Methods A total of 1369 female patients were included in this study. Mammography was performed on full field detector digital mammography equipment. Craniocaudal (CC) view and mediolateral oblique (MLO) view were carried out for each breast. Four views were done for 1322 patients. The remaining 47 patients had undergone a mastectomy and underwent two views for the other breast. Mistakes in improperly positioned mammogram were assessed with respect to proper visualization of nipple, position of pectoralis major, pectoral–nipple distance (PND), inframammary fold, and adequate coverage of all breast quadrants. Results As per prescribed guidelines, mistakes in positioning were recognized in 2.879% of total mammograms. Improper positioning of the nipple was the commonest problem, seen in 3.827% of mammograms, CC view. On MLO view, bilaterally, pectoralis shadow was not seen in 0.520% mammograms, its margin was not straight/convex in 0.706%, lower edge of pectoralis was above pectoralis–nipple line in 2.081%, and inframammary fold was not seen in 1.189%. There was inadequate coverage of lower quadrants in 2.787%, and mismatch in PND was seen in 3.864%. In few of the patients, the shortcomings as a result of improper positioning were noted on one view, the rest being normal. Conclusion Positioning is the most important factor affecting the resultant mammography image. During mammography, many cases are improperly positioned and as a result the examination is inconclusive, which reduces the sensitivity of mammography.
Semantic Clustering and Processing Speed in Suzuki Violinists
Authors: Bugos Jennifer , Mazuc Jennifer 
Published: July 2014

AbstractThe purpose of this research was to examine the effects of Suzuki violin instruction on verbal memory performance, memory strategy usage, and visual processing speed performance in child musicians and non-musicians, ages 8–12. Thirty-five participants, 18 musicians with four or more years of musical training and 17 non-musicians, completed measures of music aptitude, motor speed, music reading, intelligence, verbal memory, and processing speed. Results indicate significantly (p &lt; .05) enhanced performance by musicians compared to non-musicians in verbal memory performance, including distraction list items, short-delay free recall trials, semantic clustering scores, and overall processing speed. These data support the hypothesis that Suzuki violin instruction leads to the development of semantic and syntactical knowledge to categorize words assisting in memory retrieval. Results underscore the role of auditory skills in early music instruction, the impact of musical training in cognitive development, and importance of providing musical training at an early age.
Progesterone Receptor and PTEN Expression Predict Survival in Patients With Low- and Intermediate-Grade Pancreatic Neuroendocrine Tumors
Authors: Estrella Jeannelyn S. , Broaddus Russell R. , Mathews Amber , Milton Denái R. , Yao James C. , Wang Huamin , Rashid Asif 
Published: July 2014

Context.—The PI3K-AKT-mTOR (phosphatidylinositol 3-kinase–AKT–mammalian target of rapamycin) pathway plays a crucial role in a subset of advanced pancreatic neuroendocrine tumors (PanNETs). In breast and endometrial carcinoma, activation of this pathway inhibits progesterone receptor (PR) expression.
Objective.—To determine whether combined low expression of PR and phosphatase and tensin homologue (PTEN), a negative regulator of the PI3K-AKT-mTOR pathway, is a prognostic factor.
Design.—A total of 160 resected PanNETs (89 low grade and 71 intermediate grade) were analyzed for PR and PTEN immunohistochemical positivity and staining was correlated with metastasis-free survival (MFS) and overall survival (OS). Progesterone receptor staining was scored as positive by using 1% or greater as cutoff. Weak/faint staining in greater than 90% of tumor cells was considered low PTEN positivity.
Results.—Most PanNETs (110 cases, 69%) were both PR and PTEN positive, 45 (28%) were either PR or PTEN positive, and only 5 (3%) had a PR-negative and PTEN-low profile. Combined PR-PTEN positivity was significantly associated with MFS in patients with stage I and II disease (P &lt;.001) and OS in all patients (P &lt; .001) and remained a significant predictor of survival after adjusting for other factors. Patients with PR-negative–PTEN-low PanNETs had the shortest median MFS and OS, compared to those with tumors that were either PR or PTEN positive and with tumors positive for both PR and PTEN (P ≤ .001).
Conclusion.—Combined immunohistochemical assessment of PR and PTEN may help identify a small subset of PanNETs with more aggressive behavior and may aid in risk stratification.
Primary Closure of Elective Toe Amputations in the Diabetic Foot—Is it Safe?
Authors: Lakstein Dror , Lipkin Alexander , Schorr Louis , Feldbrin Zeev 
Published: July 2014

BackgroundToe amputation is the most common partial foot amputation. Controversy exists regarding whether to primarily close toe amputations or to leave them open for secondary healing. The purpose of this study was to evaluate the results of closed toe amputations in diabetic patients, with respect to wound healing, complications, and the need for further higher level amputation.MethodsWe retrospectively reviewed the results of 40 elective or semi-elective toe amputations with primary closure performed in 35 patients treated in a specialized diabetic foot unit. Patients with abscesses or necrotizing fasciitis were treated emergently and were excluded. Patients in whom clean margins could not be achieved due to extensive cellulitis or tenosynovitis and patients requiring vascular intervention were excluded as well. Outcome endpoints included wound healing at 3 weeks, delayed wound healing, or subsequent higher level amputation.ResultsOut of 40 amputations, 38 healed well. Thirty amputations healed by the time of stitch removal at 3 weeks and eight had delayed healing. In two patients the wounds did not heal and subsequent higher level amputation was eventually required.ConclusionsIn carefully selected diabetic foot patients, primary closure of toe amputations is a safe surgical option. We do not recommend primary closure when infection control is not achieved or in patients requiring vascular reconstruction. Careful patient selection, skillful assessment of debridement margins and meticulous technique are required and may be offered by experienced designated surgeons in a specialized diabetic foot unit.
Space‐time model for repeating earthquakes and analysis of recurrence intervals on the San Andreas Fault near Parkfield, California
Authors: Nomura Shunichi , Ogata Yosihiko , Nadeau Robert M. 
Published: July 2014

AbstractWe propose a stochastic model for characteristically repeating earthquake sequences to estimate the spatiotemporal change in static stress loading rate. These earthquakes recur by a cyclic mechanism where stress at a hypocenter is accumulated by tectonic forces until an earthquake occurs that releases the accumulated stress to a basal level. Renewal processes are frequently used to describe this repeating earthquake mechanism. Variations in the rate of tectonic loading due to large earthquakes and aseismic slip transients, however, introduce nonstationary effects into the repeating mechanism that result in nonstationary trends in interevent times, particularly for smaller‐magnitude repeating events which have shorter interevent times. These trends are also similar among repeating earthquake sites having similar hypocenters. Therefore, we incorporate space‐time structure represented by cubic B‐spline functions into the renewal model and estimate their coefficient parameters by maximizing the integrated likelihood in a Bayesian framework. We apply our model to 31 repeating earthquake sequences including 824 events on the Parkfield segment of the San Andreas Fault and estimate the spatiotemporal transition of the loading rate on this segment. The result gives us details of the change in tectonic loading caused by an aseismic slip transient in 1993, the 2004 Parkfield M6 earthquake, and other nearby or remote seismic activities. The degree of periodicity of repeating event recurrence intervals also shows spatial trends that are preserved in time even after the 2004 Parkfield earthquake when time scales are normalized with respect to the estimated loading rate.
Deep crustal structure in the eastern Gulf of Mexico
Authors: Christeson G. L. , Van Avendonk H. J. A. , Norton I. O. , Snedden J. W. , Eddy D. R. , Karner G. D. , Johnson C. A. 
Published: July 2014

AbstractWe use air gun data recorded by ocean bottom seismometers to constrain the velocity structure along Gulf of Mexico Basin Opening Line 4, a profile extending from the northwestern Florida peninsula across the Florida Escarpment to the central Gulf of Mexico. Moderately thinned continental crust with a Moho depth of 32–33 km, average sediment thickness of 6 km, and an average crustal thickness of 27 km is interpreted on the northeast end of the profile offshore Florida. Thinned and intruded continental crust is identified over a horizontal distance of 225 km where the crustal layer thins from 25 km to 6–7 km; mean seismic velocities of the crust in this region increase from 6.55 km/s to 6.95 km/s from northeast to southwest and are evidence for increased magmatic input as rifting developed. Oceanic crust with an average thickness of 5.6–5.7 km is observed over a distance of 175 km on the southwest end of the profile, with an extinct spreading ridge with an axial valley morphology imaged on a coincident seismic reflection profile. Anomalously high upper oceanic crust velocities of 6.0–6.7 km/s are interpreted as massive basalt flows and could reflect increased temperatures during emplacement. Integrating well, seismic reflection and our seismic refraction data allow us to estimate a full‐spreading rate of 2.2 cm/yr for seafloor spreading along the profile; this indicates that oceanic crust was emplaced at a slow‐spreading center.
Saltwater‐freshwater mixing dynamics in a sandy beach aquifer over tidal, spring‐neap, and seasonal cycles
Authors: Heiss James W. , Michael Holly A. 
Published: July 2014

AbstractThe biogeochemical reactivity of sandy beach aquifers is closely linked to physical flow and solute transport processes. Thus, a clearer understanding of the hydrodynamics in the intertidal zone is needed to accurately estimate chemical fluxes to the marine environment. A field and numerical modeling study was conducted over a 1 year timeframe to investigate the combined effects of tidal stage, spring‐neap variability in tidal amplitude, and seasonal inland water table oscillations on intertidal salinity and flow dynamics within a tide‐dominated, microtidal sandy beach aquifer. Measured and simulated salinities revealed an intertidal saline circulation cell with a structure and cross‐sectional mixing zone area that varied over tidal, spring‐neap, and seasonal time scales. The size of the circulation cell and area of the mixing zone were shown for the first time to be most affected by seasonal water table oscillations, followed by tidal amplitude and tidal stage. The intertidal circulation cell expanded horizontally and vertically as the inland water table declined, displacing the fresh discharge zone and lower interface seaward. Over monthly spring‐neap cycles, the center of the circulation cell shifted from beneath the backshore and upper beachface to the base of the beach. Salinity variations in the intertidal zone over semidiurnal tidal cycles were minimal. The dynamics of the circulation cell were similar in simulations with and without a berm. The highly transient nature of intertidal salinity over multiple time scales may have important implications for the types and rates of chemical transformations that occur in groundwater prior to discharge to the ocean.
An Unexpected Addition of Acetic Acid to ortho‐Electron‐ Deficient Alkynyl‐Substituted Aryl Aldehydes Catalyzed by Palladium(II) Acetate
Authors: Zhang Jianbo , Han Xiuling 
Published: July 2014

AbstractAn unexpected addition of acetic acid to ortho‐electron‐deficient alkynyl‐substituted aryl aldehydes catalyzed by palladium(II) acetate was achieved, which provided a convenient method for the synthesis of dihydroisobenzofurans in moderate to good yields. The electron‐withdrawing groups attached to alkynes may play an important role for the cyclization.magnified image
N‐Heterocyclic Carbene/Brønsted Base Cascade Catalysis: Base‐Controlled Selective Synthesis of Multifunctional Benzofuran‐3‐ones or Flavone Derivatives from the Reaction of 3‐(2‐Formylphenoxy)propenoates with Imines
Authors: Zhao Yuan , Wang Zi‐Tian , Cheng Ying 
Published: July 2014

AbstractThe N‐heterocyclic carbene/Brønsted base cascade catalysis in the reaction of 3‐(2‐formylphenoxy)propenoates with N‐Boc‐arylimines has been studied. Both multifunctional benzofuran‐3‐ones and benzopyran‐4‐ones (flavone derivatives) were selectively synthesized in good yields simply by regulating the loading of the base catalyst.magnified image
Regioselective Ring‐Opening Nucleophilic Addition of Aziridines through Photoredox Catalyst
Authors: Sun Hongnan , Yang Chao , Lin Run , Xia Wujiong 
Published: July 2014

AbstractA mild and efficient procedure was developed for the regioselective ring‐opening nucleophilic addition reactions of aziridines via visible light photoredox catalysis, that provides a practical synthetic access to 1,2‐bifunctional compounds. Furthermore, the regioselective synthesis of non‐racemic amino ethers from chiral aziridine could also be achieved under mild conditions. Finally, a possible reaction mechanism was proposed and further supported by control experiments.magnified image
Synthesis of Benzocoumarins and Characterization of Their Photophysical Properties
Authors: Kim Dokyoung , Xuan Qui Pham , Moon Hyunsoo , Jun Yong Woong , Ahn Kyo Han 
Published: July 2014

AbstractBenzocoumarins (benzochromenones) are π‐extended coumarins and constitute a promising family of photonic materials. Disclosed here are syntheses and characterization of the photophysical properties of a series of benzo[g]coumarins and benzo[f]coumarins that contain both an electron donor and an electron acceptor which are electronically conjugated through the benzocoumarin core. The maximum absorption and emission wavelengths of benzo[g]coumarins are at longer wavelengths than the corresponding benzo[f]coumarins, as the former family has favourable intramolecular charge transfer from the donor to the acceptor moiety due to linear conjugation. The emission behaviour of the benzocoumarins is dependent on solvent due to their dipolar nature. The fluorescence of benzo[f]coumarins that have a dimethylamino donor at the C9 or C7 position is much weaker in polar media such as dimethyl sulfoxide (DMSO) and water compared with that of the corresponding benzo[g]coumarins. Comparison of a benzo[g]coumarin and a benzo[h]coumarin that have the same donor and acceptor groups shows that the Stokes shift of the former is larger than the latter. The benzo[g]coumarin series is highly promising for bioimaging applications because they are known to be two‐photon excitable around 900 nm, an optimum biological optical window. The synthetic routes established here provide a basis to obtain functional benzocoumarin derivatives.
Frontal ostium neo‐osteogenesis and patency after Draf III procedure: a computer‐assisted study
Authors: Ye Ting , Hwang Peter H. , Huang Zhenxiao , Huang Qian , Xian Junfang , Li Cheng , Zhou Bing 
Published: July 2014

BackgroundStenosis of the frontal neo‐ostium after Draf III procedure has been associated with inflammatory risk factors. However, the degree to which neo‐osteogenesis contributes to postsurgical stenosis of the frontal neo‐ostium is unclear.MethodsTwenty‐five patients with chronic frontal sinusitis who underwent Draf III procedure and had been followed for at least 12 months were included. Paranasal sinus computed tomography (CT) scans were performed 7 days and 1 year postoperatively. The frontal neo‐ostium cross‐sectional area and the amount of frontal neo‐osteogenesis were measured by a standardized protocol using triplanar radiologic viewing software. Association between the severity of frontal neo‐osteogenesis and the patency of the neo‐ostium was analyzed, as was the correlation between the extent of neo‐osteogenesis and the preoperative Global Osteitis Scoring Scale (GOSS), Lund‐Mackay score (LMS), Lund‐Kennedy score (LKS), serum eosinophil count, and history of previous surgery.ResultsAt 1 year postoperatively, significant inverse correlation was found between the size of the frontal neo‐ostium and the extent of neo‐osteogenesis. According to a multiple linear regression model, the severity of neo‐osteogenesis was positively correlated with preoperative GOSS and negatively correlated with asthma (p < 0.05). Additionally, there was no association between extent of neo‐osteogenesis and the preoperative LMS, LKS, serum eosinophil count, and history of previous surgery.ConclusionNeo‐osteogenesis has a significant impact on the patency of the frontal neo‐ostium but appears unrelated to inflammatory factors. Patients with a higher risk for developing neo‐osteogenesis can be identified preoperatively based on GOSS; these patients may benefit from closer monitoring during the follow‐up period.
Proteintemplat‐vermittelter Acyltransfer: eine chemische Methode für die Markierung von Membranproteinen an lebenden Zellen
Authors: Reinhardt Ulrike , Lotze Jonathan , Zernia Sarah , Mörl Karin , Beck‐Sickinger Annette G. , Seitz Oliver 
Published: July 2014

AbstractEine neue Methode zur chemischen Proteinmarkierung läuft mit hoher Zielspezifität innerhalb weniger Minuten ab und ermöglicht eine freie Wahl des Reportermoleküls. Sie beruht auf Peptidtemplaten, die einen Thioester und ein N‐terminales Cystein so ausrichten, dass eine Acyltransferreaktion bei nanomolarer Konzentration möglich wird. Das Zielprotein wird N‐terminal mit einem 22 Aminosäure langen Cys‐E3‐Peptid (Akzeptor) ausgestattet, das mit einem Reporter‐tragenden K3‐Peptid (Donor) ein Coiled‐Coil bilden kann. Dadurch wird die Übertragung des Reportermoleküls auf den Akzeptor am Zielprotein ausgelöst. Weil die Ligierung der wechselwirkenden Peptide vermieden wird, ist der Massenzuwachs am Zielprotein minimal. Zur Veranschaulichung der Methode werden die rasche Fluoreszenzmarkierung und die fluoreszenzmikroskopische Untersuchung des humanen Y2‐Rezeptors an lebenden Zellen gezeigt.
Chemical Sealing of Nanotubes: A Case Study on Sb2S3
Authors: Sarkar Suresh , Guria Amit K. , Patra Biplab K. , Pradhan Narayan 
Published: July 2014

AbstractImplementing the solution chemistry, herein, we report the sealing of both ends of Sb2S3 semiconductor nanotubes following the diffusion‐controlled deposition of the sealing material, AgSbS2. As a consequence, unique dumbbell‐shaped hollow nanocapsules having a binary–ternary epitaxial heterojunction were formed in solution. Whereas these capsule‐shaped nanostructures were obtained by the introduction of Ag0 nanocrystals just after the formation of Sb2S3 nanotubes, the addition of Ag0 at the beginning of the process, prior to the formation of nanotubes, changed the growth pattern, and solid nanorods of Sb2S3 were formed. The details of the chemistry involved in the formation of these nanostructures were investigated and are discussed herein.
Catalytic Methylation of CH Bonds Using CO2 and H2
Authors: Li Yuehui , Yan Tao , Junge Kathrin , Beller Matthias 
Published: July 2014

AbstractFormation of CC bonds from CO2 is a much sought after reaction in organic synthesis. To date, other than CH carboxylations using stoichiometric amounts of metals, base, or organometallic reagents, little is known about CC bond formation. In fact, to the best of our knowledge no catalytic methylation of CH bonds using CO2 and H2 has been reported. Described herein is the combination of CO2 and H2 for efficient methylation of carbon nucleophiles such as indoles, pyrroles, and electron‐rich arenes. Comparison experiments which employ paraformaldehyde show similar reactivity for the CO2/H2 system.
Paenilamicin: Structure and Biosynthesis of a Hybrid Nonribosomal Peptide/Polyketide Antibiotic from the Bee Pathogen Paenibacillus larvae
Authors: Müller Sebastian , Garcia‐Gonzalez Eva , Mainz Andi , Hertlein Gillian , Heid Nina C. , Mösker Eva , van den Elst Hans , Overkleeft Herman S. , Genersch Elke , Süssmuth Roderich D. 
Published: July 2014

AbstractThe spore‐forming bacterium Paenibacillus larvae is the causative agent of American Foulbrood (AFB), a fatal disease of honey bees that occurs worldwide. Previously, we identified a complex hybrid nonribosomal peptide/polyketide synthesis (NRPS/PKS) gene cluster in the genome of P. larvae. Herein, we present the isolation and structure elucidation of the antibacterial and antifungal products of this gene cluster, termed paenilamicins. The unique structures of the paenilamicins give deep insight into the underlying complex hybrid NRPS/PKS biosynthetic machinery. Bee larval co‐infection assays reveal that the paenilamicins are employed by P. larvae in fighting ecological niche competitors and are not directly involved in killing the bee larvae. Their antibacterial and antifungal activities qualify the paenilamicins as attractive candidates for drug development.
PyBidine/Copper Catalyst: Asymmetric exo′‐Selective [3+2] Cycloaddition using Imino Ester and Electrophilic Indole
Authors: Awata Atsuko , Arai Takayoshi 
Published: July 2014

AbstractElectrophilic indoles having two electron‐withdrawing groups undergo nucleophilic attack at C2 and electrophilic functionalization at C3. This is the first enantioselective formal [3+2] cycloaddition using electrophilic indoles. The PyBidine/Cu catalyst smoothly promoted highly enantio‐ and exo′‐selective [3+2] cycloaddition using imino esters and 3‐nitroindoles. This reaction provides a method for the preparation of diverse and complex chiral pyrroloindoline compounds.
Furanosyl Oxocarbenium Ion Stability and Stereoselectivity
Authors: van Rijssel Erwin R. , van Delft Pieter , Lodder Gerrit , Overkleeft Herman S. , van der Marel Gijsbert A. , Filippov Dmitri V. , Codée Jeroen D. C. 
Published: July 2014

AbstractLewis acid mediated substitution reactions using [D]triethylsilane as a nucleophile at the anomeric center of the four pentofuranoses, ribose, arabinose, xylose, and lyxose, all proceed with good to excellent stereoselectivity to provide the 1,2‐cis adducts. To unravel the stereoelectronic effects underlying the striking stereoselectivity in these reactions we have mapped the energy landscapes of the complete conformational space of the oxocarbenium ions of the four pentofuranoses. The potential energy surface maps provide a detailed picture of the influence of the differently oriented substituents and their mutual interactions on the stability of the oxocarbenium ions and the maps can be used to account for the observed stereoselectivities of the addition reactions.