bluuebunny/crossref_metadata_2025 huggingface dataset:
Resident and hospitalist perspectives on the “great teaching case”: Correlation with actual patient assignment decisions
Authors: Roberts Daniel L. , Labonte Helene R. , Cheng Meng‐Ru , Chang Yu‐Hui H.
Published: May 2014

BACKGROUND

With the advent of limits to resident duty hours and the size of teaching services, many academic institutions have introduced nonteaching services, often triaging perceived better teaching cases to the resident services.

OBJECTIVE

To compare resident versus faculty perceptions of ideal cases for teaching services and compare these perceptions with actual triage decisions made by faculty who assigned patients to either teaching or nonteaching services.

DESIGN

Residents and hospitalist faculty were surveyed about their perceptions of ideal and actual teaching admissions, first with qualitative, open‐ended questions and then with quantitative, specific questions generated from responses to the first survey. Characteristics of patients admitted to teaching and nonteaching services were analyzed retrospectively and compared with resident and faculty perceptions.

RESULTS

Residents and faculty agreed that rare cases, patients with unique physical findings, and a variety of pathology were ideal for teaching services and that social admissions, benefactors, and patients with chronic or functional pain were not. Residents believed that traditional (“bread and butter”) medicine cases were under‐represented on the teaching services. Although residents perceived that they received a disproportionate number of older patients, outside transfers, patients with chronic pain, and patients with cancer, the only statistically significant difference was in patient age, with the teaching service actually receiving younger patients (66.7 vs 69.3 years; P = 0.008).

CONCLUSIONS

Residents and faculty have similar views about ideal teaching cases, but a triage system based on perceived educational merit creates the possibility of resident misperceptions about their case mix, even if patients are distributed relatively equitably. Journal of Hospital Medicine 2014;9:508–514. © 2014 Society of Hospital Medicine
Approximation of the inverse of the Hodge matrix via sparsity pattern
Authors: Moura A.S. , Saldanha R.R. , Silva E.J. , Lisboa A.C. , Facco W.G.
Published: May 2014

The solution of electromagnetic wave propagation problems in time domain using an explicit method requires the inversion of Hodge matrices. This paper proposes an approximation to obtain a sparse inverse via the sparsity pattern of the original matrix. It is also shown the application of the algorithm Cuthill–McKee on Hodge matrices in order to reduce their bandwidth and thus speed up the method of recursive sparsification. Copyright © 2014 John Wiley & Sons, Ltd.
Characterization of nitrogen and water status in oat leaves using optical sensing approach
Authors: Zhao Baoping , Ma Bao‐Luo , Hu Yuegao , Liu Jinghui
Published: May 2014

BACKGROUND

Optical sensing is a potential tool to estimate plant N status, but soil water deficits may interefere with forming a clear relationship. A greenhouse study was conducted with oat plants treated with three water regimes and four N levels to determine whether optical sensing could be used to estimate leaf N and relative water content (RWC).

RESULTS

Leaf N was strongly correlated with reflectance at 550 nm and at around 705 nm, and N treatments caused a red‐edge peak shift to lower wavelength. The ratio of the first derivative reflectance at 741–696 nm (FDRE) was identified to be a good estimator of leaf N at jointing (R2 = 0.90) and heading (R2 = 0.86) stages across water treatments. Leaf N also had a stronger association with the red‐edge position (REP) at both stages (R2 = 0.83 and 0.78), or with the ratio R4 (R760/R550) at jointing (R2 = 0.88), than with chlorophyll meter (SPAD) readings. Under water stress, the predictive accuracy of leaf N increased with these reflectance indices, but decreased using SPAD readings.

CONCLUSION

The results indicate that specific reflectance indices of FDRE, REP and R4 may be used for a rapid and non‐destructive estimation of oat plant N status over a range of water regimes. © 2014 Her Majesty the Queen in Right of Canada Journal of the Science of Food and Agriculture © 2014 Society of Chemical Industry
Development of a new stir bar sorptive extraction method for the determination of medium‐level volatile thiols in wine
Authors: Elpa Decibel , Durán‐Guerrero Enrique , Castro Remedios , Natera Ramón , Barroso Carmelo G.
Published: May 2014

A fast, simple, and reliable analytical method for the determination of medium‐level volatile thiols in wines is presented. Stir bar sorptive extraction using ethylene glycol‐silicone coated stir bars has been used in combination with thermal desorption gas chromatography with mass spectrometry for the analysis of 4‐mercapto‐4‐methylpentan‐2‐one, 2‐furanmethanethiol, 3‐mercaptohexyl acetate, and 3‐mercaptohexanol in wine. Optimization of the extraction technique was performed using a two‐level fractional factorial design. For the extraction step, the optimum conditions were: Ethylene glycol and silicone coated stir bars, pH at 3.5, sample volume of 25 mL, extraction time of 90 min, NaCl content 4.0 g, and stirring speed at 500 rpm. The optimized method achieved good linearity for all studied compounds (r2 > 0.995) and it provided detection limits of 21.52, 0.36, 0.73, and 2.55 μg/L for 4‐mercapto‐4‐methylpentan‐2‐one, 2‐furanmethanethiol, 3‐mercaptohexyl acetate, and 3‐mercaptohexanol, respectively. It was repeatable, with precisions lower than 18% relative standard deviation for both intraday and interday repeatability. The developed procedure is suitable for the determination of these kinds of compounds when they are present at medium concentration levels. It was finally applied to real wine samples with negative aroma derived from the high concentration levels of these compounds.
Alpha-fetoprotein level > 1000 ng/mL as an exclusion criterion for liver transplantation in patients with hepatocellular carcinoma meeting the Milan criteria
Authors: Hameed Bilal , Mehta Neil , Sapisochin Gonzalo , Roberts John P. , Yao Francis Y.
Published: May 2014

Serum alpha-fetoprotein (AFP) has been increasingly recognized as a marker for a poor prognosis after liver transplantation (LT) for hepatocellular carcinoma (HCC). Many published reports, however, have included a large proportion of patients with HCC beyond the Milan criteria, and the effects of incorporating AFP as an exclusion criterion for LT remain unclear. We studied 211 consecutive patients undergoing LT for HCC within the Milan criteria according to imaging under the Model for End-Stage Liver Disease organ allocation system between June 2002 and January 2009. The majority (93.4%) had locoregional therapy before LT. The median follow-up was 4.5 years (minimum = 2 years). The Kaplan-Meier 1- and 5-year patient survival rates were 94.3% and 83.4%, respectively. In a univariate analysis, significant predictors of HCC recurrence included vascular invasion [hazard ratio (HR) = 10, 95% confidence interval (CI) = 3.9–26, P < 0.001], a pathological tumor stage beyond the University of California San Francisco criteria (HR = 4.1, 95% CI = 1.36–12.6, P = 0.01), an AFP level > 1000 ng/mL (HR = 4.5, 95% CI = 1.3–15.3, P = 0.02), and an AFP level > 500 ng/mL (HR = 3.1, 95% CI = 1.04–9.4, P = 0.04). In a multivariate analysis, vascular invasion was the only significant predictor of tumor recurrence (HR = 5.6, 95% CI = 1.9–19, P = 0.02). An AFP level > 1000 ng/mL was the strongest pretransplant variable predicting vascular invasion (odds ratio = 6.8, 95% CI = 1.6–19.1, P = 0.006). The 1- and 5-year rates of survival without recurrence were 90% and 52.7%, respectively, for patients with an AFP level > 1000 ng/mL and 95% and 80.3%, respectively, for patients with an AFP level ≤ 1000 ng/mL (P = 0.026). Applying an AFP level > 1000 ng/mL as a cutoff would have resulted in the exclusion of 4.7% of the patients from LT and a 20% reduction in HCC recurrence. In conclusion, an AFP level > 1000 ng/mL may be a surrogate for vascular invasion and may be used to predict posttransplant HCC recurrence. Incorporating an AFP level > 1000 ng/mL as an exclusion criterion for LT within the Milan criteria may further improve posttransplant outcomes. Liver Transpl 20:945–951, 2014. © 2014 AASLD.
Antimicrobial Polyurethane Thermosets Based on Undecylenic Acid: Synthesis and Evaluation
Authors: Lluch Cristina , Esteve‐Zarzoso Braulio , Bordons Albert , Lligadas Gerard , Ronda Juan C. , Galià Marina , Cádiz Virginia
Published: May 2014

In the present study, plant oil‐derived surface‐modifiable polyurethane thermosets are presented. Polyol synthesis is carried out taking advantage of thiol‐yne photopolymerization of undecylenic acid derivatives containing methyl ester or hydroxyl moieties. The prepared methyl ester‐containing polyurethanes allow surface modification treatment to enhance their hydrophilicity and impart antimicrobial activity through the following two steps: i) grafting poly(propylene glycol) monoamine (Jeffamine M‐600) via aminolysis and ii) Jeffamine M‐600 layer complexation with iodine. The antimicrobial activity of the iodine‐containing polyurethanes is demonstrated by its capacity to inhibit the growth of Staphylococcus aureus, and Candida albicans in agar media.
Regulation of p53‐targeting microRNAs by polycyclic aromatic hydrocarbons: Implications in the etiology of multiple myeloma
Authors: Gordon Michael W. , Yan Fang , Zhong Xiaoming , Mazumder Pranab Behari , Xu‐Monette Zijun Y. , Zou Dehui , Young Ken H. , Ramos Kenneth S. , Li Yong
Published: May 2014

Multiple myeloma (MM) is a common and deadly cancer of blood plasma cells. A unique feature of MM is the extremely low somatic mutation rate of the p53 tumor suppressor gene, in sharp contrast with about half of all human cancers where this gene is frequently mutated. Eleven miRNAs have been reported to repress p53 through direct interaction with the 3' untranslated region. The expression of nine of them is higher in MM plasma cells than in healthy donor counterparts, suggesting that miRNA overexpression is responsible for p53 inactivation in MM. Here, we report that the environmental carcinogen benzo[a]pyrene (BaP) upregulated the expression of seven p53‐targeting miRNAs (miR‐25, miR‐15a, miR‐16, miR‐92, miR‐125b, miR‐141, and miR‐200a), while 2,3,7,8‐tetrachlorodibenzo‐ρ‐dioxin (TCDD) upregulated two of them (miR‐25 and miR‐92) in MM cells. The miR‐25 promoter was activated by both BaP and TCDD, and this response was mediated by the aryl hydrocarbon receptor (AhR). We screened 727 compounds that inhibit MM cell survival and down‐regulate the expression of p53‐targeting miRNAs. We found that (−)‐epigallocatechin‐3‐gallate (EGCG), a constituent of green tea and a major component of the botanical drug Polyphenon® E, reduced the expression of four p53‐targeting miRNAs, including miR‐25, miR‐92, miR‐141, and miR‐200a. Collectively, these data implicate polycyclic aromatic hydrocarbons and AhR in the regulation of p53‐targeting miRNAs in MM and identify a potential therapeutic and preventive agent to combat this deadly disease. © 2014 Wiley Periodicals, Inc.
Functional implications of the p.Cys680Arg mutation in the MLH1 mismatch repair protein
Authors: Dominguez‐Valentin Mev , Drost Mark , Therkildsen Christina , Rambech Eva , Ehrencrona Hans , Angleys Maria , Lau Hansen Thomas , de Wind Niels , Nilbert Mef , Juel Rasmussen Lene
Published: May 2014

In clinical genetic diagnostics, it is difficult to predict whether genetic mutations that do not greatly alter the primary sequence of the encoded protein causing unknown functional effects on cognate proteins lead to development of disease. Here, we report the clinical identification of c.2038 T>C missense mutation in exon 18 of the human MLH1 gene and biochemically characterization of the p.Cys680Arg mutant MLH1 protein to implicate it in the pathogenicity of the Lynch syndrome (LS). We show that the mutation is deficient in DNA mismatch repair and, therefore, contributing to LS in the carriers.
Nonempirical calculations of the one‐bond 29Si–13C spin–spin coupling constants taking into account relativistic and solvent corrections
Authors: Rusakova Irina L. , Rusakov Yury Yu. , Krivdin Leonid B.
Published: May 2014

The computational study of the one‐bond 29Si–13C spin–spin coupling constants has been performed at the second‐order polarization propagator approximation (SOPPA) level in the series of 60 diverse silanes with a special focus on the main factors affecting the accuracy of the calculation including the level of theory, the quality of the basis set, and the contribution of solvent and relativistic effects. Among three SOPPA‐based methods, SOPPA(MP2), SOPPA(CC2), and SOPPA(CCSD), the best result was achieved with SOPPA(CCSD) when used in combination with Sauer's basis set aug‐cc‐pVTZ‐J characterized by the mean absolute error of calculated coupling constants against the experiment of ca 2 Hz in the range of ca 200 Hz. The SOPPA(CCSD)/aug‐cc‐pVTZ‐J method is recommended as the most accurate and effective computational scheme for the calculation of 1J(Si,C). The slightly less accurate but essentially more economical SOPPA(MP2)/aug‐cc‐pVTZ‐J and/or SOPPA(CC2)/aug‐cc‐pVTZ‐J methods are recommended for larger molecular systems. It was shown that solvent and relativistic corrections do not play a major role in the computation of the total values of 1J(Si,C); however, taking them into account noticeably improves agreement with the experiment. The rovibrational corrections are estimated to be of about 1 Hz or 1–1.5% of the total value of 1J(Si,C). Copyright © 2014 John Wiley & Sons, Ltd.
Observation of true and pseudo NOE signals using CEST‐MRI and CEST‐MRS sequences with and without lipid suppression
Authors: Lu Jianhua , Zhou Jinyuan , Cai Congbo , Cai Shuhui , Chen Zhong
Published: May 2014

Purpose

To investigate the characteristics of nuclear Overhauser enhancement (NOE) imaging signals in the brain at 7T.

Methods

Fresh hen eggs, as well as six healthy, and six C6 glioma‐bearing Wistar rats were scanned using chemical exchange saturation transfer‐magnetic resonance imaging (CEST‐MRI) and chemical exchange saturation transfer‐magnetic resonance spectroscopy (CEST‐MRS) sequences (saturation duration 3 s, power 1.47 µT) with and without lipid suppression. CEST data were acquired over an offset range of −6 to +6 ppm relative to the water resonance in 0.5 ppm steps.

Results

The water signals were not disrupted by other protons during the CEST‐MRS sequences, and true NOE signals could be observed. Using the CEST‐MRI sequence without lipid suppression, pseudo NOE imaging signals were observed in the lipid‐containing regions (egg yolk, scalp, and even white matter). These pseudo NOE signals were almost (but incompletely) removed with the lipid suppression. Egg yolk results indicated the presence of the NOE to olefinic protons overlapping with the water signal. In vivo experiments showed that the amide proton transfer signal was larger in the tumor, whereas the NOE signal was larger in the normal white matter.

Conclusions

True NOE signals can be detected using MRS sequences, and considerable pseudo NOE imaging signals may be observed using MRI sequences. Magn Reson Med 73:1615–1622, 2015. © 2014 Wiley Periodicals, Inc.
Property Rights and Forest Commons
Authors: Coleman Eric A. , Liebertz Scott S.
Published: May 2014

Although property rights have been linked to a variety of positive social outcomes at the macro‐level, less research focuses on how property rights affect the benefits that actors receive at the micro‐level. This article examines property rights to a common‐pool resource (CPR) that are asymmetrically allocated among users, and presents a theoretical argument that property rights affect the allocation of resource benefits in two important ways. First, users with extensive property rights receive more benefits than users with limited property rights. Second, users with the power to influence how community rules are enforced—for example, landholders and ethnic majorities—more effectively define and defend their property and thus receive disproportionate CPR benefits compared to users with similar levels of property rights, but with less power. Using household‐level survey data in Bolivia, Kenya, Mexico, and Uganda, collected after a period of property rights decentralization, the empirical analysis finds support for these propositions. We conclude that power critically moderates the effects of property rights on the commons.
Effects of alternating temperatures and humidity on the moisture absorption and mechanical properties of ramie fiber reinforced phenolic plates
Authors: Yang Zhaohui , Xian Guijun , Li Hui
Published: May 2014

In this article, ramie fiber reinforced phenolic (RFRP) plates were prepared with compression molding process, and the plates were subjected to 98% humidity environment and alternating temperatures (from 25°C to 55°C in 24 h for a cycle) for 4 weeks. The resulted moisture absorption and the variation of the mechanical properties of RFRPs were studied. As found, compared to constant exposure temperatures (25°C or 60°C), alternating temperatures brought in higher moisture uptake and more serious degradation in the flexural strength, flexural modulus and short beam shear strength of the RFRP samples under the same humidity condition. The deteriorated effects of alternating temperatures is attributed to more remarkable degradation of the bonding between the fiber and resin, due to the moisture uptake and the internal cyclic stress around the ramie fibers with alternating temperatures. The flexural modulus of RFRP plates was much more susceptible to the moisture uptake than the flexural strength. After fully drying, the mechanical properties of the RFRP samples were recovered to some extent, but still less than the original values, indicating permanent damages occurred. Fiber Bragg grating sensors embedded in the RFRP plate was applied to monitor the variation of the internal strain during the exposure. As indicated, the moisture absorption and alternating temperatures bring in relaxation of the internal tension stress formed during compressing process, and decrease in the coefficient of thermal expansion of the RFRP samples. POLYM. COMPOS., 36:1590–1596, 2015. © 2014 Society of Plastics Engineers
Preparation of a novel phosphorus‐ and nitrogen‐containing flame retardant and its synergistic effect in the intumescent flame‐retarding polypropylene system
Authors: Zheng Zaihang , Liu, Bingnan Wang, Ting Yang Songfeng , Cui Xuejun , Wang Hongyan
Published: May 2014

A novel phosphorus‐ and nitrogen‐containing flame retardant (melamine phytate) was synthesized via the reaction between melamine and phytic acid. The chemical structure of melamine phytate (MPA) was confirmed by Fourier transform‐infrared spectra (FT‐IR) and elemental analysis. And the thermal behavior of MPA investigated by thermogravimetric analysis (TGA) demonstrates that MPA possesses a good char‐forming ability at high temperature. Besides, limiting oxygen index (LOI) and vertical burning tests (UL‐94) illustrate that polypropylene/melamine phytate/dipentaerythritol (PP/MPA/DPER) (70/22.5/7.5) can reach the LOI value of 28.5% and achieve V‐0 rating at the flame retardant loading of 30 wt%. Except that, the thermal weight loss of MPA and DPER in PP composites was investigated by TGA in detail. Moreover, the char residue of PP composite after combustion was systematically analyzed by FT‐IR, scanning electron microscope (SEM) and X‐ray photoelectron spectroscopy (XPS), which can further propose and confirm the flame retardant mechanism. POLYM. COMPOS., 36:1606–1619, 2015. © 2014 Society of Plastics Engineers
CLASSIFICATION ACCURACY OF ORAL READING FLUENCY AND MAZE IN PREDICTING PERFORMANCE ON LARGE‐SCALE READING ASSESSMENTS
Authors: Decker Dawn M. , Hixson Michael D. , Shaw Amber , Johnson Gloria
Published: May 2014

The purpose of this study was to examine whether using a multiple‐measure framework yielded better classification accuracy than oral reading fluency (ORF) or maze alone in predicting pass/fail rates for middle‐school students on a large‐scale reading assessment. Participants were 178 students in Grades 7 and 8 from a Midwestern school district. The multiple‐measure framework yielded classification accuracy rates that were either similar to, or better than, the individual predictors. Specificity was improved using a combined measure of ORF and maze versus individual predictors alone. Educational implications for identifying students in need of reading intervention are discussed.
Laserlicht auf den Punkt gebracht
Authors: Lingnau Benjamin , Lüdge Kathy
Published: May 2014

Halbleiter‐Laserdioden werden ständig weiterentwickelt. Neben den weit verbreiteten Quantentroglasern führte das zu den Quantenpunktlasern. Halbleiter‐Quantenpunkte sind winzige Kristallpyramiden, die für die Wellenpakete der Elektronen nulldimensionale Objekte darstellen. Sie wirken als künstliche Atome im Halbleitermaterial, die zum Lasern angeregt werden. Die Anregung geschieht über Elektronenstreuung. Quantenpunktlaser sind in ihrem dynamischen Verhalten viel stabiler als Quantentroglaser, was von Vorteil für die optische Datenübertragung ist. Die Quantenpunkte variieren in ihrer Größe und können so in verschiedenen Wellenlängen lasern, was kurze Pulse erlaubt. Mit einem Laserstrahl von außen kann man sie wie künstliche Neuronen oder optische Schalter mit zwei Schaltzuständen steuern. Dies und ihr geringer Energieverbrauch machen sie für technische Anwendungen interessant, darunter auch völlig neue.
Achtung Solarofen
Authors: Vollmer Michael , Möllmann Klaus‐Peter
Published: May 2014

Konkav gewölbte Glasfassaden von Großbauten können bei ungünstiger Orientierung zur Sonne zum Brennspiegel werden. Unfreiwillig berühmt gewordene Beispiele sind das Vdara‐Hotel in Las Vegas und das “Walkie‐Talkie”‐Hochhaus in London. Dieser Effekt tritt auch nur an bestimmten Tagen bei passendem Sonnenstand auf. Da die Fassaden keine perfekten Parabolspiegel sind, produzieren sie keinen scharfen Brennpunkt, sondern aufgeweitete Brennflecke, sogenannte Kaustiken. Trotzdem können dort hohe Bestrahlungsstärken auftreten. Simulationen und Experimente mit Modellen bestätigen dies.
Klimamodelle und Globale Erwärmung
Authors: Marotzke Jochem
Published: May 2014

Die vom Menschen verursachte globale Erwärmung ist in ihrer physikalischen Grundlage sehr gut verstanden und robust nachgewiesen. Ihre quantitative Abschätzung weist allerdings noch immer erhebliche Unsicherheiten von bis zu 50 % auf. Die von Menschen freigesetzten Treibhausgase verändern den Strahlungshaushalt der Atmosphäre und erhöhen den Energieinhalt des Klimasystems. Klimamodelle basieren in ihrem Kern auf physikalischen Grundgesetzen. Entscheidend für ihre Entwicklung ist eine möglichst gute Kenntnis der Rückkopplungen im Klimasystem. Heutige Modelle können die beobachtete langfristige, global gemittelte Erwärmung sehr gut wiedergeben. Die in den letzten 15 Jahren beobachtete Abschwächung der Erwärmung an der Erdoberfläche wirft zwar faszinierende Fragen zur natürlichen Klimavariabilität auf. Sie ist jedoch weitgehend irrelevant für den langfristigen anthropogenen Klimawandel.
Der innere Kreislauf der Erde
Authors: Futterer Birgit , Egbers Christoph
Published: May 2014

GeoFlow ist ein Schwerelosigkeitsexperiment zur bildhaften Untersuchung von Strömungen im flüssigen Erdkern oder im zähflüssigen Erdmantel. Es erfasst vereinfacht die wichtigsten Antriebsmechanismen im Erdinneren, wie Temperaturunterschiede, Rotation und Materialeigenschaften. Gleichzeitig lassen sich mit den Ergebnissen Computermodelle überprüfen.
Das Dropleton – ein neues Quasiteilchen in Halbleitern
Authors: Kira Mackillo , Koch Stephan W. , Cundiff Steven T.
Published: May 2014

In der quantenmechanischen Beschreibung ausgedehnter, kristalliner Festkörpersysteme definiert man verschiedene Quasiteilchen. Diese besitzen in vielerlei Beziehung Teilchencharakter, aber ihre physikalischen Eigenschaften werden von den Wechselwirkungen im Kristall beeinflusst. Unsere Gruppe von der Universität Marburg und Boulder (Colorado) hat kürzlich ein neues Quasiteilchen nachgewiesen, das wir als Dropleton bezeichnen.
Wenn es knallt und kracht
Authors: Vollmer Michael , Möllmann Klaus‐Peter
Published: May 2014

An die Knallgasprobe erinnert sich wohl noch jeder aus dem Chemieunterricht. Die Zeitskala, auf der Wasserstoff und Sauerstoff reagieren hängt davon ab, ob die beiden Reaktionsgase zu Beginn getrennt oder gemischt vorliegen. Dies zeigt sich deutlich in Hochgeschwindigkeits‐Aufnahmen von Experimenten, bei denen Luftballons entweder mit reinem Wasserstoff oder aber mit Knallgas gefüllt werden.
Die App Oszilloskop analysiert Schall oder elektrische Signale
Authors: Hirth Michael , Kuhn Jochen , Wilhelm Thomas , Lück Stephan
Published: May 2014

Im Alltag sind wir von Geräuschen aller Art umgeben. Die App Oszilloskop für iOS stellt Signale dar, die vom internen Mikrofon, dem Mikrofoneingang des Klinkensteckers oder einem USB‐Adapter stammen können. Diese Signale kann man dann mit verschiedenen Werkzeugen auswerten. Außerdem lassen sich elektrische Signale darstellen und analysieren. Oszilloskop ist deshalb der bereits früher beschriebenen App Audio Kit überlegen.
Die Heizung der Sonne
Authors: Loos Andreas
Published: May 2014

An seiner berühmtesten Veröffentlichung hat er gar nicht mitgeschrieben. Ohne sein Wissen und gegen den Willen des “dritten” Autors hat ein Kollege seinen Nachnamen hinzugefügt, weil er so gut passte: Die Autorennamen bilden einen Dreiklang, der an den Anfang des Alphabets erinnert.
Auf den Schnitt kommt's an
Authors: Vilgis Thomas
Published: May 2014

Einer alten, kontrovers diskutierten Metzgerregel zufolge, sollten Steaks, Lenden oder anderes Muskelfleisch immer quer zur Faser geschnitten werden. Bei bestens gereiftem Muskelfleisch für ein Carpaccio ist das in der Tat unerlässlich – und das aus guten physikalischen Gründen.
Interior Ballistics Simulation of the Two Chambers GLMAV Launcher
Authors: Krcmar Jan , Steinbach Claude , Dahhani Khalid
Published: May 2014

The concept of a gun launched micro air vehicle (GLMAV) is currently studied at ISL. A micro air vehicle (MAV) packaged in a projectile is launched using the energy delivered by a portable weapon. When it reaches the apogee the projectile is transformed in such a way that the MAV becomes operational over the zone to be observed. A light projectile of 80 mm caliber has to be launched with low velocity: 57 or 100 m s−1. To achieve these velocities a very low pressure in the tube is needed. Hence the GLMAV launcher is designed as a two chambers system. Propellants and igniters are enclosed in a small high‐pressure canister, which is connected to the tube with the projectile (low pressure chamber) by vent holes. The charge consists of two propellants in partially separated volumes; the fast burning GB propellant ignites the slow burning L1 propellant. The interior ballistics of the GLMAV launcher is solved by the zero dimensional model STANAG 4367 with an extension for the two chambers system. Calculated pressures in the high and low pressure chamber and the muzzle velocities are compared with ISL measurements. Although the used theoretical model cannot describe correctly all specific features of the GLMAV launcher, the differences between the calculated and measured maximum values are up to 10 %.
A course on noncommutative geometry in string theory
Authors: Blumenhagen R.
Published: May 2014

In this pedagogical mini course the basics of the derivation of the noncommutative structures appearing in string theory are reviewed. First we discuss the well established appearance of the noncommutative Moyal‐Weyl star‐product in the correlation functions of open string vertex operators on a magnetized D‐brane. Second, we will review the most recent attempts to generalize these concepts to the closed string moving in a nongeometric flux background.
A fault recovery‐based scheduling algorithm for cloud service reliability
Authors: Qi Ping , Li Longshu
Published: May 2014

Because of the unreliable and dynamic characteristics, cloud service failures are inevitable. It has an adverse effect on task execution and scheduling. To improve cloud service reliability, we first analyze the fault recovery mechanism, and then, cloud service failures considered in this paper are classified into unrecoverable failures and recoverable failures. By extending the traditional dynamic level scheduling (DLS) algorithm, a novel scheduling algorithm based on fault recovery mechanism named fault recovery‐based DLS algorithm is proposed to reduce the failure probability of task scheduling. The experimental results confirm that fault recovery mechanism can meet the reliability requirements of cloud computing infrastructures and the proposed algorithm can effectively ensure trustworthy execution of tasks. Copyright © 2014 John Wiley & Sons, Ltd.
New venture strategic adaptation: The interplay of belief structures and industry context
Authors: Kiss Andreea N. , Barr Pamela S.
Published: May 2014

We adopt an information processing perspective to investigate how the interplay of belief structures and industry context shapes new venture strategic adaptation in a sample of 104 publicly traded new ventures founded between 1996 and 2006 in several technology‐intensive industries. Results highlight that distinct espoused belief structures attributes (complexity, centrality, proactive causal logics) and industry growth combinations predict diversity, frequency, and speed of new venture strategic actions. We contribute to prior literature on early firm strategic adaptation by providing an elaborated understanding of the role of espoused belief structures in interpreting and translating industry signals into new venture strategic action. Further, we highlight the role of belief structures in facilitating the fast, diverse, and frequent organizational actions typically associated with continuous adaptation. Copyright © 2014 John Wiley & Sons, Ltd.
Ex Vivo Molecular Rejuvenation Improves the Therapeutic Activity of Senescent Human Cardiac Stem Cells in a Mouse Model of Myocardial Infarction
Authors: Avolio Elisa , Gianfranceschi Giuseppe , Cesselli Daniela , Caragnano Angela , Athanasakis Emmanouil , Katare Rajesh , Meloni Marco , Palma Anita , Barchiesi Arianna , Vascotto Carlo , Toffoletto Barbara , Mazzega Elisa , Finato Nicoletta , Aresu Giuseppe , Livi Ugolino , Emanueli Costanza , Scoles Giacinto , Beltrami Carlo Alberto , Madeddu Paolo , Beltrami Antonio Paolo
Published: May 2014

Cardiac stem cells (CSC) from explanted decompensated hearts (E-CSC) are, with respect to those obtained from healthy donors (D-CSC), senescent and functionally impaired. We aimed to identify alterations in signaling pathways that are associated with CSC senescence. Additionally, we investigated if pharmacological modulation of altered pathways can reduce CSC senescence in vitro and enhance their reparative ability in vivo. Measurement of secreted factors showed that E-CSC release larger amounts of proinflammatory cytokine IL1β compared with D-CSC. Using blocking antibodies, we verified that IL1β hampers the paracrine protective action of E-CSC on cardiomyocyte viability. IL1β acts intracranially inducing IKKβ signaling, a mechanism that via nuclear factor-κB upregulates the expression of IL1β itself. Moreover, E-CSC show reduced levels of AMP protein kinase (AMPK) activating phosphorylation. This latter event, together with enhanced IKKβ signaling, increases TORC1 activity, thereby impairing the autophagic flux and inhibiting the phosphorylation of Akt and cAMP response element-binding protein. The combined use of rapamycin and resveratrol enhanced AMPK, thereby restoring downstream signaling and reducing IL1β secretion. These molecular corrections reduced E-CSC senescence, re-establishing their protective activity on cardiomyocytes. Moreover ex vivo treatment with rapamycin and resveratrol improved E-CSC capacity to induce cardiac repair upon injection in the mouse infarcted heart, leading to reduced cardiomyocyte senescence and apoptosis and increased abundance of endogenous c-Kit+ CSC in the peri-infarct area. Molecular rejuvenation of patient-derived CSC by short pharmacologic conditioning boosts their in vivo reparative abilities. This approach might prove useful for refinement of CSC-based therapies. Stem Cells  2014;32:2373–2385
Engineering the Human Thymic Microenvironment to Support Thymopoiesis In Vivo
Authors: Chung Brile , Montel-Hagen Amélie , Ge Shundi , Blumberg Garrett , Kim Kenneth , Klein Sam , Zhu Yuhua , Parekh Chintan , Balamurugan Arumugam , Yang Otto O. , Crooks Gay M.
Published: May 2014

A system that allows manipulation of the human thymic microenvironment is needed both to elucidate the extrinsic mechanisms that control human thymopoiesis and to develop potential cell therapies for thymic insufficiency. In this report, we developed an implantable thymic microenvironment composed of two human thymic stroma populations critical for thymopoiesis; thymic epithelial cells (TECs) and thymic mesenchyme (TM). TECs and TM from postnatal human thymi were cultured in specific conditions, allowing cell expansion and manipulation of gene expression, before reaggregation into a functional thymic unit. Human CD34+ hematopoietic stem and progenitor cells (HSPC) differentiated into T cells in the aggregates in vitro and in vivo following inguinal implantation of aggregates in immune deficient mice. Cord blood HSPC previously engrafted into murine bone marrow (BM), migrated to implants, and differentiated into human T cells with a broad T cell receptor repertoire. Furthermore, lentiviral-mediated expression of vascular endothelial growth factor in TM enhanced implant size and function and significantly increased thymocyte production. These results demonstrate an in vivo system for the generation of T cells from human HSPC and represent the first model to allow manipulation of gene expression and cell composition in the microenvironment of the human thymus. Stem Cells  2014;32:2386–2396
Selection Via Pluripotency-Related Transcriptional Screen Minimizes the Influence of Somatic Origin on iPSC Differentiation Propensity
Authors: Hartjes Katherine A. , Li Xing , Martinez-Fernandez Almudena , Roemmich Alexa J. , Larsen Brandon T. , Terzic Andre , Nelson Timothy J.
Published: May 2014

The value of induced pluripotent stem cells (iPSCs) within regenerative medicine is contingent on predictable and consistent iPSC differentiation. However, residual influence of the somatic origin or reprogramming technique may variegate differentiation propensity and confound comparative genotype/phenotype analyses. The objective of this study was to define quality control measures to select iPSC clones that minimize the influence of somatic origin on differentiation propensity independent of the reprogramming strategy. More than 60 murine iPSC lines were derived from different fibroblast origins (embryonic, cardiac, and tail tip) via lentiviral integration and doxycycline-induced transgene expression. Despite apparent equivalency according to established iPSC histologic and cytomorphologic criteria, clustering of clonal variability in pluripotency-related gene expression identified transcriptional outliers that highlighted cell lines with unpredictable cardiogenic propensity. Following selection according to a standardized gene expression profile calibrated by embryonic stem cells, the influence of somatic origin on iPSC methylation and transcriptional patterns was negated. Furthermore, doxycycline-induced iPSCs consistently demonstrated earlier differentiation than lentiviral-reprogrammed lines using contractile cardiac tissue as a measure of functional differentiation. Moreover, delayed cardiac differentiation was predominately associated with upregulation in pluripotency-related gene expression upon differentiation. Starting from a standardized pool of iPSCs, relative expression levels of two pluripotency genes, Oct4 and Zfp42, statistically correlated with enhanced cardiogenicity independent of somatic origin or reprogramming strategy (R2 = 0.85). These studies demonstrate that predictable iPSC differentiation is independent of somatic origin with standardized gene expression selection criteria, while the residual impact of reprogramming strategy greatly influences predictable output of tissue-specification required for comparative genotype/phenotype analyses. Stem Cells  2014;32:2350–2359
A Novel Oncogenic Role of Inositol Phosphatase SHIP2 in ER-Negative Breast Cancer Stem Cells: Involvement of JNK/Vimentin Activation
Authors: Fu Chiung-Hui , Lin Ruey-Jen , Yu John , Chang Wen-Wei , Liao Guo-Shiou , Chang Wen-Ying , Tseng Ling-Ming , Tsai Yi-Fang , Yu Jyh-Cherng , Yu Alice L.
Published: May 2014

Overexpression of SH2-containing-5′-inositol phosphatase-2 (SHIP2) correlates with poor survival in breast cancer. However, its role in breast cancer stem cells (BCSCs) remains unclear. Here, we showed that the percentage of SHIP2+ cells was positively correlated with that of CD24−CD44+ cells in 60 breast cancer specimens. Among 20 estrogen receptor (ER)-negative samples, 17 had greater SHIP2 expression in CD24−CD44+ subpopulation than the remaining subpopulation. Data mining of microarray analysis of 295 breast tumors showed a significant correlation of higher SHIP2 expression with distant metastasis. Examination of patient-derived mouse xenografts revealed that SHIP2 protein and its tyrosine 1135 phosphorylation were significantly higher in BCSCs, identified as CD24−CD44+ or aldehyde dehydrogenase (ALDH+), than non-BCSCs. SHIP2 silencing or inhibitor of SHIP2 phosphatase significantly decreased mammosphere-forming efficiency, ALDH+ subpopulation in vitro and tumorigenicity of BCSCs in vivo. Overexpression of SHIP2 enhanced the expression of epithelial–mesenchymal transition markers including vimentin (VIM), which was mainly expressed in ER-negative breast cancer cells with higher level in mammospheres than monolayer culture. Ablation of c-Jun N-terminal kinase 1 (JNK1), JNK2, or VIM diminished the increased ALDH+ population and tumorigenicity, induced by SHIP2 overexpression. BCSCs displayed greater expression of phospho-JNK than non-BCSCs and silencing of JNK suppressed SHIP2-mediated upregulation of VIM. Furthermore, SHIP2 overexpression enhanced Akt activation, but Akt inhibition failed to influence SHIP2-induced phospho-JNK/VIM upregulation. In conclusion, SHIP2 plays a key role in BCSCs of ER-negative breast cancers through activation of Akt and JNK with upregulation of VIM and may serve as a target for therapy directed at BCSCs. Stem Cells  2014;32:2048–2060
Importance of Cell-Cell Contact in the Therapeutic Benefits of Cardiosphere-Derived Cells
Authors: Xie Yucai , Ibrahim Ahmed , Cheng Ke , Wu Zhijun , Liang Wenbin , Malliaras Konstantinos , Sun Baiming , Liu Weixin , Shen Deliang , Cheol Cho Hee , Li Taosheng , Lu Lin , Lu Guoping , Marbán Eduardo
Published: May 2014

Cardiosphere-derived cells (CDCs) effect therapeutic regeneration after myocardial infarction (MI) both in animal models and in humans. Here, we test the hypothesis that cell-cell contact plays a role in mediating the observed therapeutic benefits of CDCs, above and beyond conventional paracrine effects. Human CDCs or vehicle were injected into immunodeficient (SCID) mouse hearts during acute MI. CDC transplantation augmented the proportion of cycling (Ki67+) cardiomyocytes and improved ventricular function. CDC-conditioned media only modestly augmented the percentage of Ki67+ cardiomyocytes (>control but <CDCs), but did not improve pump function. When neonatal rat ventricular myocytes (NRVMs) were cocultured with human CDCs in vitro, the percentage of cycling NRVMs (Ki67+ or BrdU+ nuclei) increased relative to solitary NRVM culture. To further dissect the relative contributions of soluble factors versus contact-dependent mechanisms, we compared CDCs grown with NRVMs in a transwell contact-free system versus admixed coculture. The percentage of cycling NRVMs was higher in admixed coculture than in the contact-free system. Pretreatment with inhibitors of MEK and PI3K, or with β1 integrin neutralizing antibody, blocked the ability of CDCs to promote myocyte cycling. While conditioned media are not inert, direct apposition of CDCs to cardiomyocytes produces greater enhancement of cardiomyocyte proliferation in vitro and in vivo, and improves function post-MI. Intact cardiomyocyte β1 integrin signaling is necessary for the contact-dependent cardioproliferative effects of CDCs. Stem Cells  2014;32:2397–2406
Elements for Adequate Informed Consent in the Surgical Context
Authors: Abaunza Hernando , Romero Klaus
Published: May 2014

Given a history of atrocities and violations of ethical principles, several documents and regulations have been issued by a wide variety of organizations. They aim at ensuring that health care and clinical research adhere to defined ethical principles. A fundamental component was devised to ensure that the individual has been provided the necessary information to make an informed decision regarding health care or participation in clinical research. This article summarizes the history and regulations for informed consent and discusses suggested components for adequate consent forms for daily clinical practice in surgery as well as clinical research.
High Survival in Patients Operated for Small Isolated Liver Metastases from Gastric Cancer: A Multi‐institutional Study
Authors: Komeda Koji , Hayashi Michihiro , Kubo Shoji , Nagano Hiroaki , Nakai Takuya , Kaibori Masaki , Wada Hiroshi , Takemura Shigekazu , Kinoshita Masahiko , Koga Chikato , Matsumoto Masataka , Sakaguchi Tatsuma , Inoue Yoshihiro , Hirokawa Fumitoshi , Kwon A‐Hon , Uchiyama Kazuhisa
Published: May 2014

Background

Although several studies have reported the outcomes of surgery for the treatment of liver metastases of gastric cancer (GLM), indications for liver resection for gastric metastases remain controversial. This study was designed to identify prognostic determinants that identify operable hepatic metastases from gastric cancer and to evaluate the actual targets of surgical therapy.

Methods

Retrospective analysis was performed on outcomes for 24 consecutive patients at five institutions who underwent gastrectomy for gastric cancer followed by curative hepatectomy for GLM between 2000 and June 2012.

Results

Overall 5‐year survival and median survival were 40.1 % and 22.3 months, respectively. Uni‐ and multivariate analyses showed that liver metastatic tumour size less than 5 cm was the most important predictor of overall survival (OS, p = 0.03). Four patients survived >5 years. Repeat hepatectomy was performed in three patients. Two of these patients have remained disease‐free since the repeat hepatectomy.

Conclusions

GLM patients with metastatic tumour diameter less than 5 cm maximum are the best candidates for hepatectomy. Hepatic resection should be considered as an option for gastric cancer patients with liver metastases.
Japanese D3 Lymph Node Dissection in Low Rectal Cancer with Inferior Mesenteric Lymph Node Metastases
Authors: Ubukata Mamiko , Itabashi Michio , Kameoka Shingo
Published: May 2014

Background

There is currently no consensus on the significance of Japanese D3 lymph node dissection in low rectal cancer with inferior mesenteric lymph node (IMLN) metastasis. This is partly because, despite a number of studies on the subject, cases of IMLN metastasis are relatively rare, and there are few cases of curative resection because of metastasis to other organs. A retrospective study involving a large number of patients was conducted.

Methods

The subjects were 2,743 patients registered in the national registry of the Japanese Society for Cancer of the Colon and Rectum. The data were analyzed for (1) prognostic factors for IMLN metastasis, and (2) outcomes in R0 cases with IMLN metastasis.

Results

In the control group, 67 patients (2.7 %) were considered positive for IMLN metastasis. The outcomes in the 35 R0 cases with IMLN metastasis were 50.8 % for 5‐year relapse‐free survival (RFS) and 61.9 % for 5‐year overall survival (OS), which were each better than for R1+R2 cases (5‐year RFS 16.1 %, p = 0.0001; 5‐year OS 26.7 %, p = 0.0002). The outcomes for R0 cases (total metastatic lymph nodes ≥7) with IMLN metastasis (5‐year RFS 53.9 %, 5‐year OS 68.8 %) did not differ significantly from those for IMLN(−) cases (5‐year RFS 54.6 %, 5‐year OS 57.1 %) (RFS: p = 0.9515, OS: p = 0.4621).

Conclusions

It was confirmed that cases of IMLN metastasis in low rectal cancer tend to have a large total number of metastatic lymph nodes, but if curative resection can be performed, a good prognosis can be expected. These results demonstrate the value of radical Japanese D3 lymph node dissection in low rectal cancer with IMLN metastasis.
Investigation of Micellization and Vesiculation of Conjugated Linoleic Acid by Means of Self‐Assembling and Self‐Crosslinking
Authors: Fan Ye , Fang Yun , Ma Lin , Jiang Hang
Published: May 2014

Bioactive and biocompatible conjugated linoleic acid (CLA) has been only considered as a food or medicine ingredient due to its rare natural occurrence. In this work, the surface activities and pH‐induced self‐assembling behaviors of the semi‐synthetic CLA molecules into micelles or vesicles were systematically investigated. First, the self‐assembling of CLA was studied in detail, and it was found that aside from temperature and ionic strength, pH is the prominent factor affecting the self‐assembling of CLA. Moreover, stable CLA ufasomes (unsaturated fatty acid liposomes) in uniform size were obtained by self‐crosslinking of the CLA ufasomes, and the morphologies of the crosslinked CLA assemblies were recorded by transmission electron microscopy, which made known the pH‐induced formation of the CLA ufasomes or the CLA micelles. The crosslinked CLA assemblies presented improved properties such as a higher calcium stability, a lower lime soap dispersing requirement and a better solubilization ability than that of the CLA molecules themselves or the pre‐crosslinked linoleic acids. These investigations could be helpful for comprehensively understanding effects of environment factors on self‐assembling behaviors of conjugated fatty acids and responsive polymerization of polymerizable surfactants.
Lipidomics Reveals Mitochondrial Membrane Remodeling Associated with Acute Thermoregulation in a Rodent with a Wide Thermoneutral Zone
Authors: Pan Qian , Li Min , Shi Yao‐Long , Liu Huwei , Speakman John R. , Wang De‐Hua
Published: May 2014

Mongolian gerbils (Meriones unguiculatus) have high physiological flexibility in response to acute temperature changes, and have the widest thermoneutral zone (TNZ, 26.5–38.9 °C) reported among small mammals. At the upper critical temperature (Tuc, 38.9 °C), body temperatures of gerbils were significantly increased (39–41 °C) while metabolic rates were maintained at the basal level. In contrast, below the lower critical temperature (Tlc, 26.5 °C), metabolism was elevated and body temperature stable. Rapid changes in mitochondrial membrane lipidome were hypothesized to play an important role during acute thermoregulation of gerbils. Taking advantage of a recent lipidomic technique, we examined changes in the membrane phospholipids environment and free fatty acids (FFA) production in mitochondria between 38 and 27 °C (in the TNZ), and between 27 and 16 °C (below the TNZ). At 38 °C, acute heat stress elicited distinct remodeling in mitochondrial membrane lipidome which related to a potential decrease in mitochondrial respiration and membrane fluidity compared to 27 °C. At 16 °C, a sharply decreased unsaturation index and increased chain lengths were detected in mitochondrial FFA production both in muscle and brown adipose tissue. Our results suggest that mitochondrial membrane lipid remodeling may stabilize membrane function and activity of respiration related membrane protein to maintain a stable metabolic rate at Tuc, and improve heat production by decomposing less fluid fatty acid conjugates of membrane lipids under acute cold exposure. These data therefore imply an important role of membrane remodeling during acute thermoregulation in a non‐hibernating endotherm.