bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigating the 331-Z′ mediated FCNC effects on b → sμ+μ− transitions
Authors: Singh Soram Robertson , Mawlong Barilang , D’cruz Ritu
Published: August 2018

The rare semileptonic [Formula: see text] and [Formula: see text] decay modes mediated by the [Formula: see text] transition are studied in this paper. We analyze observables such as the differential branching ratio, lepton polarization asymmetry and forward–backward asymmetry within the standard model in the low [Formula: see text] region. We then perform an analysis of the same modes within the 331 or [Formula: see text] model in which a new heavy [Formula: see text] boson contributes. The effects of the [Formula: see text]-mediated flavor-changing neutral current (FCNC) transitions on these modes are investigated by varying the mass [Formula: see text] and the model parameter [Formula: see text]. The new [Formula: see text] couplings are constrained by flavor observables of [Formula: see text] mixing and branching ratio of [Formula: see text]. We find that for some values of these couplings, the observables are quite sensitive to [Formula: see text] effects and deviations from Standard Model can be large.
No-scale SUGRA inflation and Type-I seesaw
Authors: Garg Ila , Mohanty Subhendra
Published: August 2018

We show that MSSM with three right-handed neutrinos (RHNs) incorporating a renormalizable Type-I seesaw superpotential and no-scale SUGRA Kähler potential can lead to a Starobinsky kind of inflation potential along a flat direction associated with gauge invariant combination of Higgs, slepton and right-handed sneutrino superfields. The inflation conditions put constraints on the Dirac Yukawa coupling and the Majorana masses required for the neutrino masses and also demand the tuning among the parameters. The scale of inflation is set by the mass of the heaviest right-handed neutrino. We also fit the neutrino data from oscillation experiments at low scale using the effective RGEs of MSSM with three right-handed neutrinos.
Entanglement in composite systems due to external influences
Authors: Gitman D. M. , Meireles M. S. , Levin A. D. , Shishmarev A. A. , Castro R. A.
Published: August 2018

In this paper, we consider two examples of an entanglement in two-qubit systems and an example of entanglement in quantum field theory (QFT). In the beginning, we study the entanglement of two spin states by a magnetic field. A nonzero entanglement appears for interacting spins. When the coupling between the spins is constant, we study the entanglement by several types of time-dependent magnetic fields. In the case of a constant difference between [Formula: see text] components of magnetic fields acting on each spin, we find several time-dependent coupling functions [Formula: see text] that also allow us to analyze analytically and numerically the entanglement measure. Considering two photons moving in an electron medium, we demonstrate that they can be entangled in a controlled way by applying an external magnetic field. The magnetic field affecting electrons of the medium affects photons and, thus, causes an entanglement of the photon beams. The third example is related to the effect of production of electron–positron pairs from the vacuum by a strong external electric field. Here, we have used a general nonperturbative expression for the density operator of the system under consideration. Applying a reduction procedure to this density operator, we construct mixed states of electron and positron subsystems. Calculating the von Neumann entropy of such states, we obtain the loss of information due to the reduction and, at the same time, the entanglement measure of electron and positron subsystems. This entanglement can be considered as an example of an entanglement in QFT.
The structural, elastic and thermodynamic properties of intermetallic phases in Mg–Sn–Si–Ca(Sr) alloys: A first-principles study
Authors: Li Yan , Zhao Yuhong , Hou Hua , Yang Xiaomin
Published: August 2018

The structural, elastic and thermodynamic properties of Mg2Si, Mg2Sn, CaMgSi and MgSnSr phases in Mg–Sn–Si–Ca(Sr) alloys have been investigated by implementing first-principles calculations. Formation enthalpies and cohesive energies show that MgSnSr has the strongest alloying ability and CaMgSi has the highest structural stability. The bulk modulus B, shear modulus G, Young’s modulus E, G/B, Poisson ratio [Formula: see text], anisotropy index A[Formula: see text] are estimated after evaluating the elastic constants. The mechanical properties are further analyzed and discussed. Finally, the Gibbs free energy and Debye temperature of these phases are calculated by means of the quasi-harmonic Debye model in temperature ranging from 0 K to 1000 K.
Elastic properties of the charge density wave system HoTe3
Authors: Saint-Paul M. , Guttin C. , Lejay P. , Leynaud O. , Monceau P.
Published: August 2018

We present ultrasonic measurements on the rare earth tritelluride HoTe3 compound. Different anomalies are observed at the upper and lower charge density wave phase transition T[Formula: see text] = 284 K and T[Formula: see text] = 120 K. A striking T2 temperature dependence of the velocities of the longitudinal C[Formula: see text], C[Formula: see text] and shear C[Formula: see text] modes is observed in the ordered phase below the lower CDW phase transition T[Formula: see text]. Such a behavior is related to the temperature dependence of the CDW order parameter.
Almost prime submodules
Authors: Thao Le Phuong
Published: August 2018

In this paper, we introduce the notion of almost prime submodules of a given right [Formula: see text]-module and study some properties of them as a generalization of weakly prime ideals in associative rings. We will also investigate modules in which every fully invariant submodule is almost prime.
Protein Engineering Strategies to Expand CRISPR-Cas9 Applications
Authors: Ribeiro Lucas F. , Ribeiro Liliane F. C. , Barreto Matheus Q. , Ward Richard J.
Published: August 2018

The development of precise and modulated methods for customized manipulation of DNA is an important objective for the study and engineering of biological processes and is essential for the optimization of gene therapy, metabolic flux, and synthetic gene networks. The clustered regularly interspaced short palindromic repeat- (CRISPR-) associated protein 9 is an RNA-guided site-specific DNA-binding complex that can be reprogrammed to specifically interact with a desired DNA sequence target. CRISPR-Cas9 has been used in a wide variety of applications ranging from basic science to the clinic, such as gene therapy, gene regulation, modifying epigenomes, and imaging chromosomes. Although Cas9 has been successfully used as a precise tool in all these applications, some limitations have also been reported, for instance (i) a strict dependence on a protospacer-adjacent motif (PAM) sequence, (ii) aberrant off-target activity, (iii) the large size of Cas9 is problematic for CRISPR delivery, and (iv) lack of modulation of protein binding and endonuclease activity, which is crucial for precise spatiotemporal control of gene expression or genome editing. These obstacles hinder the use of CRISPR for disease treatment and in wider biotechnological applications. Protein-engineering approaches offer solutions to overcome the limitations of Cas9 and generate robust and efficient tools for customized DNA manipulation. Here, recent protein-engineering approaches for expanding the versatility of the Streptococcus pyogenes Cas9 (SpCas9) is reviewed, with an emphasis on studies that improve or develop novel protein functions through domain fusion or splitting, rational design, and directed evolution.
Markers of Local Inflammation and Bone Resorption in the Acute Diabetic Charcot Foot
Authors: Jansen Rasmus Bo , Christensen Tomas Møller , Bülow Jens , Rørdam Lene , Jørgensen Niklas Rye , Svendsen Ole Lander
Published: August 2018

Objective. Due to the localized nature of Charcot foot, systemically altered levels of inflammation markers can be difficult to measure. The aim of this study was to investigate whether it is possible to detect an arteriovenous (A-V) flux in any locally produced inflammatory biomarkers from an acute Charcot foot by comparing local and systemic measurements. Methods. We included patients with acute diabetic Charcot foot. Blood was sampled from the vena saphena magna on the distal part of the crus bilaterally as well as from the arteria radialis. To minimize the A-V shunting effect, the feet were externally cooled with ice water prior to resampling. Results. Both before and after cooling, the A-V flux of interleukin-6 (IL-6) between the Charcot feet and the arterial level was significantly higher than the flux between the healthy feet and the arterial level (Δvaluebefore: 7.25 versus 0.41 pg/mL, resp., p=0.008; Δvalueafter: 10.04 versus 1.68 pg/mL, resp., p=0.032). There were no differences in the fluxes for other markers of inflammation. Conclusion. We have found an increased A-V flux of IL-6 in the acute diabetic Charcot foot compared to the healthy foot in the same patients.
Bone Morphogenetic Protein 6 Inhibits the Immunomodulatory Property of BMMSCs via Id1 in Sjögren’s Syndrome
Authors: Su Yingying , Gu Yi , Wu Ruiqing , Wang Hao
Published: August 2018

Mesenchymal stem cells (MSCs) treatment has emerged as a promising approach for treating Sjögren’s syndrome (SS). Impaired immunoregulatory activities of bone marrow mesenchymal stem cells (BMMSCs) are found in both SS patients and animal models, and the underlying mechanism is poorly understood. Increased expression of BMP6 is reported to be related to SS. The aim herein was to determine the effects of BMP6 on BMMSCs function. BMMSCs were isolated from SS patients and NOD mice and showed a high level of BMP6 expression. The effects of BMP6 on BMMSCs function were investigated using in vitro BMMSCs differentiation and in vitro and in vivo T cell proliferation and polarization assays. BMP6 increased osteogenic differentiation of BMMSCs and inhibited the immunomodulatory properties of BMMSCs. BMP6 enhanced T cell proliferation and Th1/Th17 differentiation in a T cell-BMMSC coculture system. Mechanistically, BMP6 downregulated PGE2 and upregulated IFN-gamma via Id1 (inhibitor of DNA-binding protein 1). Neutralizing BMP6 and knockdown of Id1 could restore the BMMSCs immunosuppressive function both in vitro and in vivo. The present results suggest a novel role of Id1 in BMP-mediated MSCs function, which may contribute to a better understanding of the mechanism of action of MSCs in treating autoimmune diseases.
Microarray Analysis of Differentially Expressed Profiles of Circular RNAs in a Mouse Model of Intestinal Ischemia/Reperfusion Injury with and Without Ischemic Postconditioning
Authors: Feng Dongcheng , Li Zhenlu , Wang Guangzhi , Yao Jihong , Li Yang , Qasim Wasim , Zhao Yongfu , Tian Xiaofeng
Published: August 2018

Background/Aims: Ischemic postconditioning (iPoC) represents a promising strategy to mitigate ischemia/reperfusion (I/R) injury of the intestine, yet the mechanisms of this treatment remain to be elucidated. Circular RNAs (circRNAs), a novel class of endogenous non-coding RNAs, have recently been recognized as important regulators of gene expression and pathological processes. Here, we aimed to investigate the expression patterns of circRNAs after intestinal I/R with and without iPoC and, furthermore, to explore the potential mechanisms of iPoC in relation to the differentially expressed circRNAs. Methods: The global circRNA and mRNA expression profiles in mouse intestinal mucosa were initially screened by microarray (n = 3 per group) and quantitative real-time PCR was used to validate the expression pattern of circRNAs and mRNAs. Bioinformatics analysis including Gene ontology, KEGG pathway analysis, microRNA binding sites identification and circRNA-miRNA-mRNA network construction were utilized for in-depth mechanism exploration. Results: There were 4 up- and 58 downregulated circRNAs as well as 322 up- and 199 downregulated mRNAs in the intestinal I/R group compared with the sham group, whereas compared with I/R, iPoC treatment significantly upregulated 12 circRNAs and 129 mRNAs and downregulated 21 circRNAs and 174 mRNAs. The expression levels of a randomly selected set of 6 circRNAs and 5 mRNAs were successfully validated by qRT-PCR. Through a systematic comparison of the direction of circRNA expression changes in all groups, we identified two circRNAs, circRNA_012412 and circRNA_016863, that may be closely associated with the protective mechanisms of iPoC. Finally, four possible circRNA_012412/circRNA_016863-miRNA-mRNA pathways were predicted, which may play important roles in endogenous protective signaling in iPoC. Conclusions: This study was the first to comprehensively delineate the expression profiles of circRNAs in a mouse model of intestinal I/R and iPoC and provides novel clues for understanding the mechanisms of iPoC against intestinal I/R injury.
Life histories, demographies and population dynamics of three sympatric chameleon species (Furcifer spp.) from western Madagascar
Authors: Eckhardt Falk , Kraus Cornelia , Kappeler Peter M.
Published: August 2018

The life histories and population dynamics of chameleons remain poorly known, most likely due to practical challenges related to their cryptic nature. However, several studies have indicated that some of these reptiles have unusually brief life histories. Specifically, one Madagascan chameleon (Furcifer labordi) was found to have an annual life cycle characterized by population-wide survival of the austral winter in the egg stage; a unique life history among tetrapods. In this study, we compare the life history of F. labordi with two locally sympatric congeners (F. cf. nicosiai and F. oustaleti) in Kirindy forest, western Madagascar, to determine how these species adjust their life histories to a highly seasonal and unpredictable climate. We found differences in lifespan, timing of hatching, growth rates, survival, reproductive rates, adult body size, and roosting heights among all three species. Moreover, two species exhibited relatively short lifespans: 6-9 months in F. labordi and 16-18 months in F. cf. nicosiai. In contrast, F. oustaleti is perennial and large-sized juveniles and adults aestivate during the dry season, but survival rates of adults seemed relatively low. Strikingly, the annual cohort of F. labordi was already adult when hatchlings of F. oustaleti and subsequently F. cf. nicosiai emerged. Our study suggests the co-existence of three different life histories with seasonal adjustment that might be related to the partitioning of overall food availability and contributes valuable life history data on enigmatic chameleon species.
Emptiness and Presence in a Non-substantialist Formulation of Trinitarian Doctrine
Authors: Kang Chris
Published: August 2018

This paper examines the ideas of emptiness (śūnyatā) and presence (svabhāva) in the discourses of Indian Madhyamika thinkers in comparison with the work of prominent Kyoto School philosopher and key figure in Buddhist-Christian dialogue, Masao Abe (1915–2006). Madhyamika’s negative dialectic and Abe’s oeuvre are applied to the trinitarian theology of Scottish theologian and churchman Thomas Forsyth Torrance (1913–2007), even as Torrance’s oeuvre is allowed to recast and illuminate notions of emptiness in light of the trinitarian faith. In this movement of ideas, the dynamic interpretations and reinterpretations of the doctrine of emptiness by Indian thinkers are brought to bear on Abe’s thought and, in turn, on Torrance’s trinitarian theology. In this way, the metaphysical basis of trinitarian doctrine is drawn into sharper focus even as an emptiness-based, non-substantialist, onto-relational theology of the Trinity emerges as a potentially viable account of the nature of the triune Godhead.
Early Holocene Occupations at Ashash Rock Shelter (Zemmur, Western Sahara)
Authors: Borrell Ferran , Alcalde Gabriel , Clemente Ignacio , Saña Maria , Soler Joaquim , Soler Narcís
Published: August 2018

The archaeological record of the Western Sahara remains extremely fragmentary, with very few sites systematically excavated. The excavation at Ashash rock shelter (Zemmur region) has provided, for the first time in the region, the evidence of superimposition of two prehistoric occupations that have been radiocarbon dated to the early 9th millennium cal.BPand to the mid-7th millennium cal.BP. The Epipalaeolithic occupation is strongly marked by the standardised production of geometric microliths and points using a microburin blow technique. The Neolithic occupation of the site has yielded a few potsherds that provide the first unambiguous evidence of pottery in the Zemmur area in the mid-7th millennium cal.BP.
A substitute name for a genus of fossil mantispid (Insecta: Neuroptera: Mesomantispinae) from the Jurassic of Kazakhstan
Authors: JEPSON JAMES E. , KHRAMOV ALEXANDER V. , OHL MICHAEL
Published: August 2018

In a recent paper (Jepson et al., 2018) a new genus of Mesomantispinae from Karatau, Kazakhstan was described. The name given to the genus, Longicollum, is unavailable, because it is preoccupied by a senior homonym, Longicollum Yamaguti, 1935 (Acanthocephala: Pomphorhynchidae). In accordance with Art. 60.1. of the ICZN, we herein propose a replacement name for the genus: Longipronotum nom. nov.
Thrombolytic therapy in acute MI: coronary care nurses' knowledge and practice
Authors: Shaaban Khalil Nahla , Sayed Ismaeel Manal , Sayed Ewees Amany
Published: August 2018

Thrombolytic therapy is commonly used to treat patients with acute myocardial infarction, and it must be administered quickly to be effective. Coronary care nurses are often the first health professionals to evaluate patients with suspected myocardial infarction in emergency rooms, and there are several protocols for prompt appraisal and management.

Aim:

The current study aimed to evaluate coronary care nurses' knowledge and practice concerning the management of patients w acute myocardial infarction receiving thrombolytic therapy.

Methods:

A descriptive cross-sectional analysis design was used. All coronary care nurses (n=30) at a university hospital in Upper Egypt were recruited. A questionnaire on demographics, a knowledge questionnaire and an observational checklist were used to collect data.

Results:

The majority of nurses (86.7%) had unsatisfactory knowledge scores about thrombolytic therapy. In addition, most of them (90%) showed unsatisfactory practices regarding administering thrombolytic therapy.

Conclusion:

Coronary care nurses' knowledge and practice were inadequate.

Recommendations:

Educational programmes should be offered to improve nurses' knowledge and practice around the administration of thrombolytic therapy to patients with acute myocardial infarction. In addition, their practice during thrombolytic drug administration should be monitored.
ECG of the month
Authors: Richley Dave
Published: August 2018

Dave Richley presents an ECG for you to analyse
The pulmonary rehabilitation regimen: a treatment for frailty and ‘inflammaging’?
Authors: Tanner A , Vassallo M , Kwan JSK , Allen SC
Published: August 2018

Pulmonary rehabilitation is an exercise-based intervention that improves walking endurance, strength, functional independence, wellbeing and the risk of re-admission to hospital. It was developed for patients recovering from acute exacerbations of chronic obstructive pulmonary disease, and sometimes other long-term inflammatory lung diseases. Many other conditions have a chronic inflammatory component, including type 2 diabetes, obesity, osteoarthritis and old age. Such background inflammation is linked to a range of adverse outcomes, including all-cause mortality, sarcopenia and other markers of frailty. Exercise, including pulmonary rehabilitation, has an anti-inflammatory effect on innate immune chemistry, and improves outcomes in a variety of conditions, although for most diagnostic groups there is no consistent structured programme similar to pulmonary rehabilitation. The authors contend that the pulmonary rehabilitation model could be used generically to treat other chronic and post-acute inflammatory states and thereby reduce the risk of frailty and other adverse outcomes.
EFFECT OF ROLE CONFLICT AND ROLE OVERLOAD TO BURNOUT AND ITS IMPACT ON CYBERLOAFING (STUDY ON PT PLN (PERSERO) PUSAT MANAJEMEN KONSTRUKSI)
Authors: Hardiani Wenefrida Ardhian ayu , Rahardja Eddy , Yuniawan Ahyar
Published: August 2018

Cyberloafing is one of the employee's counterproductive behavior by using mobile phone and office internet facility for personal use during working hours. Cyberloafing behavior is caused one of them by the psychological condition of employees, namely burnout. The cause of this burnout is due to role conflict and role overload. If the behavior of cyberloafing continues to be done will hamper the productivity of employees and eventually will have a negative impact on the company. The problem in this research is how to decrease cyberloafing by seeing role conflict, role overload, and burnout. The sample of this study amounted to 150 respondents. Sample determination was done by census technique. Respondents in this research are employees of PT PLN (Persero) Pusat Manajemen Konstruksi Semarang. The analysis tool used is Structural Equation Modeling (SEM) in AMOS 22 program.Based on five hypotheses tested, there are four accepted hypotheses. Role conflict has a significant effect on cyberloafing, role overload has no effect on cyberloafing, role conflict and burnout has a significant effect on burnout, and burnout has a significant effect on cyberloafing. In an effort to decrease the level of cyberloafing, good human resource management is required. Purpose of Human resource management is to avoid role conflict, role overload, and burnout affecting cyberloafing.
Capillary Electrophoretic Analysis of Exhaled Breath Condensate in the Diagnosis of Gastroesophageal Reflux Disease
Authors: Kubáň Peter , Ďurč Pavol , Lačná Julia , Greguš Michal , Foret František , Dolina Jiří , Konečny Štefan , Doubková Martina , Kindlová Dagmar , Pokojová Eva , Skřičková Jana
Published: August 2018

In this work, capillary electrophoresis with contactless conductometric detection (CCD) was used for the analysis of the ionic content of exhaled breath condensate (EBC) to differentiate between healthy individuals and patients with gastroesophageal reflux disease (GERD). The exhaled breath condensate was collected using a miniature sample collection device and the content analyzed using a separation electrolyte composed of 20 mM 2-(N-morpholino)ethanesulfonic acid, 20 mM L-histidine, 2 mM 18-Crown-6 and 30 M cetyltrimethylammonium bromide. The separation of anions took less than 2.5 minutes, while the cations were separated in less than 1.5 minutes. The most significantly elevated ions in the group of patients suffering from gastroesophageal reflux disease were chloride, nitrate, propionate and butyrate. Although the number of subjects was too small to draw definite conclusions with regard to the discriminatory power of these ions, the pilot data are promising for EBC as a useful non-invasive alternative for other methods used in the diagnosis of gastroesophageal reflux disease
“Yeah, but I’m Shy!”: Classroom Participation as a Social Justice Issue
Authors: DiAngelo Robin , Sensoy Özlem
Published: August 2018

In-class participation is a common component of many university students’ course grade, yet there has been some debate over whether it is fair to grade participation, given that some students are “ naturally” introverted. In this paper, we problematize the central assumption that the arguments against grading participation rest upon: that classrooms are neutral spaces into which a range of personalities come together, each with unique needs that should be recognized and supported. As educators whose work and teaching is grounded in critical social justice frameworks, we argue that there is a fundamental dynamic that is missed when silence is presumed to be a-political. We argue that classrooms are microcosms of the wider society and as such, are political spaces in which dynamics of unequal social power also play out; there is no neutral classroom or natural mode of engagement. In this paper, we lay out the foundation of a social justice approach to teaching and problematize the notion of neutral classroom spaces. We speak back to some of the most common arguments against grading classroom participation and in doing so argue that participation in classroom settings is a central element to dismantling social injustice in our wider communities.
Verfolgung der Bildung reduzierender Substanzen mit Hilfe der elektrochemischen H2O2-Meßmethode an inkubierter Chlorella pyrenoidosa im Hellen und im Dunkeln
Authors: Damaschke K.
Published: August 2018

Da bei der elektrochemischen H2O2-Messung nicht nur H2O2, sondern die Summe der reduzierenden Stoffe angezeigt wird, lag es nahe, die Bildung dieser Stoffe in Chlorellasuspensionen unter den verschiedensten Bedingungen zu untersuchen. Es wurde erst einmal grundsätzlich festgestellt, daß während der Lichteinwirkung reduzierende Stoffe gebildet werden. Die Bildung derselben wurde dann bei verschiedenen CO2-Gehalten und nach verschieden langer Inkubationszeit verfolgt. Es zeigte sich, daß die Menge der gebildeten reduzierenden Stoffe mit der Länge der vorangegangenen Inkubationszeit ansteigt. Die im Licht gebildeten reduzierenden Stoffe wurden ebenfalls im Licht wieder zersetzt. Ist dies geschehen, setzt die Photosynthese ein. Die dabei entstehenden O2 Konzentrations-Änderungen werden ebenfalls elektrochemisch gemessen. Während der Dunkelzeit werden geringe Mengen eines reduzierenden Stoffes gebildet. Die Bildung der reduzierenden Stoffe während der Hellzeit ist durch o-Phenantrolin hemmbar.
Cytologische Studien IV
Authors: Wohlfarth-Bottermann K. E.
Published: August 2018

An Hand von Dünnschnitten läßt sich im Endoplasma von Paramecium caudatum unter bestimmten experimentellen Bedingungen eine Entstehung von Mitochondrien aus cytoplasmatischen Strukturen nachweisen. Kleine „cytoplasmatische Bläschen“ vergrößern sich und bilden die für die Mitochondrien von Paramecium typischen Innenstrukturen aus. Die Ausbildung dieser Innenstrukturen, der Tubuli mitochondriales, wird eingeleitet durch das Auftreten von Mikrotubuli, deren Durchmesser nur etwa die Hälfte des Durchmessers normaler Tubuli beträgt. Auf dem Wege zur Zellperipherie wachsen diese „Promitochondrien“ mit Mikrotubuli zu normalen Mitochondrien heran.

In der Zellperipherie von Paramecium vermehren sich die Mitochondrien durch Querteilung. Eine gleichmäßige Verteilung der Mitochondrien-Substanz auf die beiden Tochterstadien wird hierbei nicht beobachtet.

Bei den Paramecium-Mitochondrien läßt sich eine Abscheidung von Tubuli mitochondriales in das Cytoplasma nachweisen. Es handelt sich um eine echte Abscheidung geformter Sekrete durch die Mitochondrien, da diese die abgegebenen tubulären Strukturen regenerieren können. Die Neubildung der Tubuli beginnt wie bei der Entstehung der Mitochondrien mit den zuerst auftretenden Mikrotubuli.
Autoradiographische Untersuchungen über den Eiweißstoffwechsel von Oocyten und Eizellen
Authors: Erb Walter , Maurer Werner
Published: August 2018

Bei Oocyten und Eizellen von Seeigeln sowie bei Oocyten von Seesternen und bei pflanzlichen Eizellen zweier Braunalgen-Arten wurde die Eiweißsynthese innerhalb der verschiedenen Zellstrukturen mit 3H-Lysin und 3H-Leucin autoradiographisch untersucht. Beim Seeigel können solche Untersuchungen unter in vivo-Bedingungen durchgeführt werden.

Auch unter in vivo-Verhältnissen konnte die Bedeutung des Nucleolus für die Kerneiweiß-Synthese bei Oocyten bestätigt werden. Der Beitrag des Nucleolus zur Kerneiweiß-Synthese ist bei Oocyten wesentlich größer als bei somatischen Zellen. Innerhalb der Zellstrukturen war die Aminosäure-Inkorporation pro Volumen-Einheit unabhängig von der Größe der Strukturen bzw. dem Entwicklungsstadium dieser Zellen. Die Eizellen der Seeigel zeigten keine Aminosäure-Inkorporation. Bei den Eizellen der beiden Fucus-Arten dominiert die Inkorporation im Cytoplasma.
Preparation and Characterization of Group III A Derivatives
Authors: Pohlmann J. L. W. , Brinckmann F. E.
Published: August 2018

Unter Verwendung des Grignard - Reagenz von Brompentafluorbenzol wurde die vollständige Reihe der Tris-(pentafluorphenyl)-Verbindungen der Elemente der dritten Hauptgruppe in siedendem Toluol dargestellt und in Form der Ätherate charakterisiert. Bei der Sublimation ergaben die Bor- und die Thallium-Verbindungen die freien Derivate. Hingegen gelang es nicht, den 1 : 1-Ätherkomplex von Tris-(pentafluorphenyl)-aluminium zu spalten; ebenso schlugen alle Versuche fehl, die ätherfreie Verbindung direkt darzustellen.

Bei der Bereitung der Indium- und der Thallium-Derivate aus den Chloriden wurden die entsprechenden Bis-(pentafluorphenyl)-metallbromide als Nebenprodukte isoliert. Demnach muß ein Halogenaustausch mit der Arylierung in Konkurrenz stehen, da bei der Verwendung von Indiumtribromid nur Bis-(pentafluorphenyl)-indiumbromid erhalten wurde.

Bei den meisten Umsetzungen trat ein fluorhaltiger, aromatischer Kohlenwasserstoff als weiteres Nebenprodukt auf; derselbe wurde auch direkt aus Pentafluorphenylmagnesiumbromid in siedendem Toluol erhalten.
Polymerisation von Methacrylsäuremethylester unter stiller elektrischer Entladung
Authors: Strohmeier W. , Grübel H.
Published: August 2018

Reiner Methacrylsäuremethylester (MM) kann unter stiller elektrischer Entladung bei Temperaturen polymerisiert werden, bei welchen eine thermische Polymerisation nicht möglich ist. Das gleiche gilt für MM, welchem Metallcarbonyle zugesetzt sind.

Zugabe von Metallcarbonylen und Tetrachlorkohlenstoff zu MM ermöglicht die entladungschemische Polymerisation bei 50° mit hohen Ausbeuten unter Bildung hochmolekularer Produkte.
Protonenresonanz-Spektroskopie ungesättigter Ringsysteme I
Authors: Günther Harald
Published: August 2018

The proton magnetic resonance spectra of 1.6-methano- and 1.6-oxido-cyclodecapentaene are described and analyzed in terms of chemical shifts and coupling constants. The results are discussed in connection with the structure and possible aromatic character of these compounds. Measurements of the concentration dependence of the chloroform resonance signal in solutions of both compounds give additional support for the presence of a delocalized 10 π-electron system.
Die dirigierende Wirkung der Guanidinium-Gruppe
Authors: Heesing A. , Wernicke U.
Published: August 2018

Die Darstellung der N-Chlor-arylguanidine gelingt nur in besonderen Fällen, da meist oxydative Ausweichreaktionen eintreten. Diese N-Chlor-Derivate lagern sich in Schwefelsäure unter Kernchlorierung um. Das Isomerenverhältnis - untersucht am Beispiel des N-Chlor-N′-phenyl-N′-methylguanidins - beträgt o: m: p = 21:17: 62. Dasselbe Ergebnis wird bei der Chlorierung des N-Phenyl-N-methyl-guanidins mit N-Chlor-N′-n-butyl-guanidin erhalten. In beiden Fällen verhält sich also die Guanidinium-Gruppe, trotz ihrer positiven Ladung, als Substituent 1. Ordnung.
Das Vorkommen von Glucosaminestern der Hydroxy-zimtsäuren in Gewebekulturen von Nicotiana tabacum
Authors: Bergmann L. , Thies W. , Erdelsky K.
Published: August 2018

Tissue cultures of Nicotiana tabacum var. “Samsun” contain an array of phenolic compounds. Beside the known glucose and quinyl esters of the hydroxycinnamic acids three hitherto unreported phenolic acid esters were isolated from tobacco tissue cultures. The analytical and spectral data presented in this paper lead to the conclusion that these compounds are glucosamine esters of p-coumaric, caffeic, and ferulic acid.
Über α- und β-Li3MeF6-Verbindungen / On α- and β-Li3MeF6 Compounds
Authors: Massa W. , Rüdorff W.
Published: August 2018

The compounds Li3MeF6 (Me = Al, Ga, Ti, V, Cr and Fe) were prepared by reaction of LiF and MeF3. We obtained the orthorhombic α-modifications on quenching, on cooling slowly the β-modifications are formed, which crystallise monoclinic, space group C6
2h (C2/c) or Cs
4 (Cc). DTA-measurements on α-Li3VF6 and the densities of both modifications suggest the α-modification to be the thermodynamical stable phase at room temperature.
II. The Photo-electric Efficiency of the Median and the Lateral Photoreceptor of the Barnacle Balanus eburneus
Authors: Krischer Christof C.
Published: August 2018

Formulae which were derived in a preceeding publication are used to analize the electrical response to flashes of 10 μsec duration of the median, Fig. 3, and the lateral photoreceptors of the barnacle Balanus eburneus in the temperature ranges 3 - 5°, 12 - 14° and 20 - 22°C. The method of measuring nerve current extracellularly is applied and discussed.

The median receptor has a response rate two times faster than the lateral receptor. The curve parameters of both receptors such as peak amplitude, latency time and initial potential increase with time obey, however, the same dependence of light intensity and temperature, provided they are normalized to the same state (halfsaturation), Figs. 4, 6, 7, Table III. With the macroscopic morphology and the electrophysiological data the photo-electric efficiency, defined as the number of univalent ions which flow across the receptor membrane for each absorbed photon, is for both receptors about 105. A complementary discussion accounting for the light-reflecting tapetum of the lateral receptor and the larger inner surface area of the median receptor yields for the median receptor a higher efficiency for flashes and a smaller efficiency for steady light. The reverse holds for the lateral receptor. A model explains this specialization of the photoreceptors with a difference in volume of the photopigment-bearing structures (microvilli).
Zinn(II)halogenid-Zinn(II)chalkogenidsysteme / Tin(II)halide-Tin(II)chalcogenide Systems
Authors: Blachnik Roger , Kasper Franz-W.
Published: August 2018

The phase diagrams of the systems SnX2-SnY (X = Cl, Br, J, Y = S, Se, Te) were determined. New compounds were found in the systems SnBr2-SnS and SnJ2-SnSe.
Hochdrucksynthese und Kristallstrukturen von TlInS2-II und TlInS2-III / High Pressure Synthesis and Crystal Structures of TlInS2-II and TlInS2-III
Authors: Range Klaus-Jürgen , Engert Gerd , Müller Wiking , Weiss Armin
Published: August 2018

Pressure treatment of TlInS2-I at 30 kbar, 300°C yielded the rhombohedral modification TlInS2-II (space group R3̄m, α = 3,83 Å, c= 22,23 Å, Z = 3). TlInS2-II has a-NaFeO2-structure and is metastable at all ρ, T-conditions investigated. At 30 kbar, 400°C, TlInS2-I and TlInS2-II transform to the hexagonal modification TlInS2-III, which was later found to be the normal pressure, low temperature modification of TlInS2. The crystal structure of Τ1Ιn2InS2-ΙΙΙ was solved from single-crystal data. The crystals are hexagonal, space group P63/mmc, with a = 3,83 Å, c = 14,88 Å and Z = 2. The structure consists of sulfur layers with a sequence ABBA ... All octahedral sites are occupied by In, and one half of the trigonal-prismatic sites by Tl. The arrangement is such as to separate Tl and In by the greatest possible distance.
Markierte Verbindungen, XVIII / On Labelled Compounds, XVIII
Authors: Boberg Friedrich , Kresse Josef
Published: August 2018

SbCl3⁻(36Cl) is prepared from SbCl3 and NaCl₋(36Cl). In the homogeneous system SbCl3⁻(36Cl)/1/CH2Cl2 and in the heterogeneous system SbCl3⁻(36Cl)/1, with solid SbCl3⁻ (36Cl), at 0-65 °C 1 is only labelled at C-1 and C-3; at 150 °C in the system SbCl3⁻(36Cl)/1 C-2 is labelled too. Carbenium intermediates explain the chlorine exchange, in accordance with investigations with 14C-labelled compounds too. The distribution of 36Cl and 14C in the molecule is proved by reactions to other labelled compounds.
Protonenresonanz-spektroskopische Untersuchungen am Chlor-, Brom- und Methylcyclobutadieneisentricarbonyl / A Proton Magnetic Resonance Investigation on Chloro-, Bromo- and Methyl-cyclobutadiene-irontricarbonyl
Authors: Brune Hans Albert , Hanebeck Hans , Horlbeck Gernot , Hüther Hans
Published: August 2018

Proton magnetic resonance spectra including all observable 13C-H-couplings have been measured for chloro-cyclobutadiene-irontricarbonyl.bromo-cyclobutadiene-irontricarbonyl and methyl-cyclobutadiene-irontricarbonyl. The results are discussed with respect to structure and bonding. The structure of a cyclic diene with alternating double and single bonds can be excluded for the four-membered ring of all three compounds. Instead the complex bonded cyclobutadiene contains an electron distribution of higher symmetry with — despite the influence of the substituent — nearly uniform bond orders.
Über substituierte Pentaphenyl-cyclopentadienyl-Verbindungen und Tetracyclone, XII1 Polarographische und EPR-spektroskopische Untersuchungen zur Konformation von Tetracyclonen und deren Radikalionen / Substituted Pentaphenylcyclopentadienyls and Tetraphenylcyclopentadienones, XII1 The Conformation of Tetraphenylcyclopentadienones and their Anion Radicals as Studied by Polarography and EPR Spectroscopy
Authors: Oestreich S. , Broser W. , Kurreck H.
Published: August 2018

The polarographic reduction of tetraarylcyclopentadienones is studied in connection with quantummechanical calculations basing on the well known structure of the corresponding ketyls. A linear free energy relationship is found assuming a change in conformation between the redox components. Comparison of the ketone geometry with the conformation of tetraarylpyrryls gives a prove for this surprising result.
Synthesis of 6-, and 7-Nitro-1,2-di-oxo-4-thioindeno[2,3,d] Pyrimidines
Authors: El-Zimaity Mohamed Tawfik , Kandeel Ezzat Mohamed , El-Morsi Saad , Elnagdi Mohamed Hilmy
Published: August 2018

Ethyl 5-nitroindan-1,3-dione-2-carboxylate (3; 5-NO2) was prepared via esterification of 3-nitrophthalic acid and subsequent treatment of the resulting diester with ethyl acetate in sodium ethoxide solution. Attempted synthesis of 3; 4-NO2 via a similar route was obscured by unability to effect diesterification of 1: 3-NO2 by ethanol and hydrochloric acid. The diester 2: 3-NO2 could be prepared by the action of ethanol on the anhydride 5. This ester could be then converted into 3: 4-NO2 by treatment with ethyl acetate and sodium ethoxide.

Compounds 3 (4- and 5-NO2) could be converted into the corresponding indeno[2,3-d]-pyrimidine derivatives (9 a, b) by their reaction with thiourea. The behaviour of 9 a, b toward the action of hydrazinehydrate, monochloroacetic acid and hydrogen peroxide is reported.
Notizen: Niedermolekulare und polymere Ätioporphyrin-germaniuIV-Komplexe / Low Molecular and Polymeric Complexes of Etioporphyrin-germaniumIV
Authors: Meyer Gunter , Wöhrle Dieter
Published: August 2018

The synthesis and spectroscopic properties of low molecular and polymeric complexes of etioporphyrin-germaniumIV are described.
Eine theoretische Begründung empirischer Sektorenregeln der optischen Aktivität / Theoretical Verification of Empirical Sector Rules of Optical Activity
Authors: Rau Hermann , Schuster Otto
Published: August 2018

A simple procedure for derivation of octant rules for optically active molecules containing a chromophoric group is developed within the framework of Kuhn's classical model of coupled oscillators. The important feature in this derivation is the clue that the locus of the center of gravity of the atoms not belonging to the chromophoric group and the direction of maximum polarizability of this ensemble of atoms are not independent. The octant rule for carbonyl compounds arrived at by this procedure is in agreement with the empirical one. A newly derived rule for cis-azo compounds is verified by empirical data.
Komplexe zweifach positiver Übergangsmetallkationen mit Hydrazido-thiophosphorsäure-estern/ Complexes of Divalent Transition Metals with Hydrazido Thiophosphoric Acid Esters
Authors: Engelhardt Udo , Friedrich Bernd , Kirner Ingeborg
Published: August 2018

Dihydrazido thiophosphoric acid phenyl ester, (NH2NH)2P(= S)-OC6H5 (DHTPPH), forms a 2:1 complex with manganese(II) chloride: [Mn(II)(DHTPPh)2Cl2], soluble in methanol. Solvolysis yields the corresponding methyl ester complex. With water in methanol the dihydrazidothiophosphato complex [Mn(II){(NH2NH)2P(= O)S}2] is formed. Monohydrazido thiophosphoric acid diphenyl ester NH2NH-P(= S)(OC6H5)2 (MHTPPh) gives various complexes with first row transition metals: [M(II)(MHTPPh)nX2], n = 2, 4; X = halogen. The nickel complex (n = 4; X = Cl) is characterized by elemental analysis and spectroscopic methods. MHTPPh is monodentate through the terminal N atoms of the hydrazido groups. Iron(II) and cadmium complexes have different compositions (n- 2; X = Cl) and therefore different structures, probably with MHTPPh as a bidentate chelate ligand.
On the Active Principles of the Euphorbiaceae, IXa Ingenane Type Diterpene Esters from Five Euphorbia Species
Authors: Gotta H. , Adolf W. , Opferkuch H. J. , Hecker E.
Published: August 2018

Investigations of E. antiquorum, E. helioscopia, E. palustris, E. peplus and E. quadrialata for irritant and tumor promoting constituents afforded several new ingenane type diterpene esters derived from the parent alcohols ingenol and 20-deoxyingenol and from the hitherto unknown 20- deoxy-16-hydroxyingenol and 20-deoxy-13.16-dihydroxyingenol. The irritant activities of the natural compounds are reported together with some aspects on structure activity relationships
Beiträge zur Chemie des Bors, 163 [1]. Die Molekülstruktur zweier Silaborazine / Contributions to the Chemistry of Boron, 163 [1]. The Molecular Structure of Two Silaborazines
Authors: Hanecker E. , Nöth H.
Published: August 2018

The crystal and molecular structure of Ph2Si(NMeBMe)2NMe (1) and MeB(NMeSiPh2 )2NMe (2) have been determined by X-ray structure analyses. Both compounds possess almost planar heterocycles. The average BN bond lengths in both compounds are practically identical (1.44 Å), but the two nonequivalent SiN bonds in 2 are significantly different (1.719, 1.732 Å). NMR data ( 1H, 11B, 13C, 27Si) are consistent with planar silaborazine rings.
Synthese unsymmetrischer Trissilylamine mit gehinderter Bindungsrotation / Synthesis of Unsymmetrical Trissilylamines with Rotational Barrier
Authors: Walter Simone , Klingebiel Uwe , Noltemeyer Mathias , Schmidt-Bäse Dieter
Published: August 2018

Bis- and tris(fluorosilyl)amines with bulky groups are prepared in the reaction of lithiated di-tert-butylfluorosilylamine with fluorosilanes. Tris(fluorosilyl)amines with three different silyl groups could be synthesized stepwise in these reactions.

In all tris(fluorosilyl)amines a rotational barrier is observed by NMR spectroscopy at room temperature. The compounds 7, 8, 11 and 12 show only one structural isomer, whereas the compounds 10, 13 and 14 show two structural isomers. To prove the conclusion drawn from the spectra, the crystal structures of 10 and 12 were determined.
Vernetzung wäßriger Alginsäure mittels der Vierkomponenten-Kondensation unter Einschluß-Immobilisierung von Enzymen / Crosslinking of Aqueous Alginic Acid by Four Component Condensation with Inclusion Immobilization of Enzymes
Authors: König Stephan , Ugi Ivar
Published: August 2018

The four component condensation (4 CC, Ugi reaction) of aqueous alginic acid with formaldehyde, difunctional amine and isocyanide components produces a gel. Enzymes, e.g. “acidic phosphatase” (AP) and L-(+)-lactate dehydrogenase (LDH), can be immobilized by inclusion in the above crosslinked alginic acid. The enzymes retain some of their activity (LDH: 8-10%; AP: 82-87%).
Die Kristallstrukturen von [MoCl2(NO)2(OPEt3)]2, [MoCl3(NO)(OPPh3)2•MoCl4(OPPh3)2], [MoCl2(NO)(PPh3)2(CH3CN)] und [MoCl4(NPPh3)(OPPh3)] / The Crystal Structures of [MoCl2(NO)2(OPEt3)]2, [MoCl3(NO)(OPPh3)2 • MoCl4(OPPh3)2], [MoCl2(NO)(PPh3)2(CH3CN)], and [MoCl4(NPPh3)(OPPh3)]
Authors: Philipp Gunnar , Wocadlo Sigrid , Massa Werner , Dehnicke Kurt , Fenske Dieter , Maichle-Mössmer Cäcilia , Niquet Elke , Strähle Joachim
Published: August 2018

The title compounds have been prepared by reactions of MoCl2(NO)2 with PPh3, OPPh3, or Me3SiNPR3 (R = Et, Ph) in dichloromethane and acetonitrile suspension, respectively. All complexes were characterized by IR spectroscopy and by crystal structure determinations. [MoCl2(NO)2(OPEt3)]2: Space group C2/c, Z = 4, 2950 observed unique reflections, R = 0.029. Lattice dimensions at —70 °C: a = 2390.5(11), b = 875.5(5), c = 1399.1(6) pm, β = 113.18(2)°. The complex forms a centrosymmetric dimer with MoCl2Mo bridges, the nitrosyl groups being in a cis-arrangement. The OPEt3 ligand is coordinated in trans position to one of the nitrosyl ligands.

[MoCl3(NO)(OPPh3)2 • MoCl4(OPPh3)2]: Space group P21/c, Z = 4, 10243 observed unique reflections, R = 0.060. Lattice dimensions at —60 °C: a = 1900.4(3), b = 1689.1(5), c = 2209.3(7) pm, β = 95.92(2)°. The structure consists of the two independent complexes [MoCl3(NO)(OPPh3)2] and [MoCl4(OPPh3)2]. In both complexes the OPPh3 groups are in a cis-arrangement at the octahedrally coordinated Mo atoms; in the nitrosyl complex one of the OPPh3 molecules is in trans-position to the nitrosyl ligand.

[MoCl2(NO)(PPh3)2(CH3CN)]: Space group P21/n, Z = 4, 5107 observed unique reflections, R = 0.028. Lattice dimensions at 20 °C: a = 1006.5(2), b = 1527.2(2), c = 2342.3(2) pm, β = 90.97(1)°. The PPh3 molecules are in trans-positions to one another at the octahedrally coordinated Mo atom, whereas the acetonitrile molecule is in trans-position to the nitrosyl ligand.

[MoCl4(NPPh3)(OPPhi)]: Space group P21, Z = 2, 3323 observed unique reflections, R = 0.057. Lattice dimensions at —70 °C: a = 985.7(8), b = 1471.2(9), c = 1215.9(11) pm, β = 100.50(3)°. The OPPh3 molecule coordinates in trans-position to the phosphorane iminato ligand at the octahedrally coordinated Mo atom.
Darstellung, 11B-NMR- und Schwingungsspektren von Aminohexahydro-closo-hexaborat(1–), [B6H6(NH2)]- sowie Kristallstruktur von Cs[B6H6(NH2)] · H2O / Preparation, 11B NMR and Vibrational Spectra of Aminohexahydro-closo-hexaborate(1–), [B6H6(NH2)]-, and the Crystal Structure of Cs[B6H6(NH2)] · H2O
Authors: Franken A. , Preetz W.
Published: August 2018

Aminohexahydro-closo-hexaborate(1–), Crystal Structure, 11B NMR Spectra, Vibrational Spectra

By reduction of [B6H5(NO2)]2- with Fe2+ in aqueous alkaline solution [B6H6(NH2)]- is formed. The compound has been separated by extraction with dichloromethane in the presence of tetrabutylammoniumbromid and precipitated from the organic phase by adding CsCH3COO/C2H5OH. The Crystal structure of Cs[B6H6(NH2)] · H2O has been determined by single crystal X-ray diffraction analysis; monoclinic space group C2 with a = 22.1075(14), b = 6.491(2), c = 5.9570(4) A, β = 100.168(6)°. The 11B NMR spectrum is consistent with a mono-hetero-substituted octahedral B6 cage with local C4v symmetry. The IR and Raman spectra exhibit characteristic N–H, B–H and B6 vibrations.
Calcium- und Bariumkomplexe mit 1-Phenyl-3-methyl-4-benzoylpyrazol-5-on / Calcium and Barium Complexes with 1-Phenyl-3-methyl-4-benzoyl-5-pyrazolone
Authors: Uhlemann Erhard , Schilde Uwe , Weller Frank
Published: August 2018

The calcium and barium complexes with 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone have been synthesized and characterized by X-ray structural analysis. Besides two molecules of the ligand, the calcium atom binds two molecules of ethanol in an octahedral coordination. The barium atom attains the coordination number 8 by coordinating 4 molecules of the pyrazolone ligand.
Über einen Lanthanoid-Mangan-Apatit: Nd4Mn(SiO4)3O / On a Lanthanoid Manganese Apatite: Nd4Mn(SiO4)3O
Authors: Klüver E. , Müller-Buschbaum Hk.
Published: August 2018

Single crystals of Nd4Mn(SiO4)3O have been prepared by a Bi2O3 flux in closed copper tubes. The colourless crystals show hexagonal symmetry, space group C6h
2—P63/m, a = 9,4986(9), c = 6,944(2) Å, Z = 2. Nd4Mn(SiO4)3O crystallizes in the Apatite structure and shows Nd3+ and Mn2+ with partly statistical distribution. As a consequence of this, O(2) and O(4) are occupying split positions.