119 research outputs found
Cooperativity‐Driven Reactivity of a Dinuclear Copper Dimethylglyoxime Complex
In this report, we present the dinuclear copper(II) dimethylglyoxime (Hdmg) complex [Cu(Hdmg)(Hdmg)(dmg)] (1), which, in contrast to its mononuclear analogue [Cu(Hdmg)] (2), is subject to a cooperativity-driven hydrolysis. The combined Lewis acidity of both copper centers increases the electrophilicity of the carbon atom in the bridging μ-O−N=C-group of Hdmg and thus, facilitates the nucleophilic attack of H2O. This hydrolysis yields butane-2,3-dione monoxime (3) and NHOH that, depending on the solvent, is then either oxidized or reduced. In ethanol, NHOH is reduced to NH, yielding acetaldehyde as the oxidation product. In contrast, in CHCN, NHOH is oxidized by Cu to form NO and [Cu(CHCN)4]. Herein are presented the combined synthetic, theoretical, spectroscopic and spectrometric methods that indicate and establish the reaction pathway of this solvent-dependent reaction
Planet Populations as a Function of Stellar Properties
Exoplanets around different types of stars provide a window into the diverse
environments in which planets form. This chapter describes the observed
relations between exoplanet populations and stellar properties and how they
connect to planet formation in protoplanetary disks. Giant planets occur more
frequently around more metal-rich and more massive stars. These findings
support the core accretion theory of planet formation, in which the cores of
giant planets form more rapidly in more metal-rich and more massive
protoplanetary disks. Smaller planets, those with sizes roughly between Earth
and Neptune, exhibit different scaling relations with stellar properties. These
planets are found around stars with a wide range of metallicities and occur
more frequently around lower mass stars. This indicates that planet formation
takes place in a wide range of environments, yet it is not clear why planets
form more efficiently around low mass stars. Going forward, exoplanet surveys
targeting M dwarfs will characterize the exoplanet population around the lowest
mass stars. In combination with ongoing stellar characterization, this will
help us understand the formation of planets in a large range of environments.Comment: Accepted for Publication in the Handbook of Exoplanet
Медицинские и социальные аспекты коммерческого секса
Представлены демографические, медицинские, психологические и социальные характеристики женщин, оказывающих платные сексуальные услуги. Обсуждается проблема легализации и регламентации проституции в контексте профилактики инфекций, передающихся половым путем, и заражения ВИЧ.Demographic, medical, psychological and social characteristics of women rendering sexual services are described. The problem of legalization and regulation of prostitution in the context of prevention of sexually transmitted infections and HIV is discussed
Paradoxical antidepressant effects of alcohol are related to acid sphingomyelinase and its control of sphingolipid homeostasis
Alcohol is a widely consumed drug that can lead to addiction and severe brain damage. However, alcohol is also used as self-medication for psychiatric problems, such as depression, frequently resulting in depression-alcoholism comorbidity. Here, we identify the first molecular mechanism for alcohol use with the goal to self-medicate and ameliorate the behavioral symptoms of a genetically induced innate depression. An induced over-expression of acid sphingomyelinase (ASM), as was observed in depressed patients, enhanced the consumption of alcohol in a mouse model of depression. ASM hyperactivity facilitates the establishment of the conditioned behavioral effects of alcohol, and thus drug memories. Opposite effects on drinking and alcohol reward learning were observed in animals with reduced ASM function. Importantly, free-choice alcohol drinking—but not forced alcohol exposure—reduces depression-like behavior selectively in depressed animals through the normalization of brain ASM activity. No such effects were observed in normal mice. ASM hyperactivity caused sphingolipid and subsequent monoamine transmitter hypo-activity in the brain. Free-choice alcohol drinking restores nucleus accumbens sphingolipid- and monoamine homeostasis selectively in depressed mice. A gene expression analysis suggested strong control of ASM on the expression of genes related to the regulation of pH, ion transmembrane transport, behavioral fear response, neuroprotection and neuropeptide signaling pathways. These findings suggest that the paradoxical antidepressant effects of alcohol in depressed organisms are mediated by ASM and its control of sphingolipid homeostasis. Both emerge as a new treatment target specifically for depression-induced alcoholism. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00401-016-1658-6) contains supplementary material, which is available to authorized users
Non-randomized therapy trial to determine the safety and efficacy of heavy ion radiotherapy in patients with non-resectable osteosarcoma
<p>Abstract</p> <p>Background</p> <p>Osteosarcoma is the most common primary malignant bone tumor in children and adolescents. For effective treatment, local control of the tumor is absolutely critical, because the chances of long term survival are <10% and might effectively approach zero if a complete surgical resection of the tumor is not possible. Up to date there is no curative treatment protocol for patients with non-resectable osteosarcomas, who are excluded from current osteosarcoma trials, e.g. <it>EURAMOS1</it>. Local photon radiotherapy has previously been used in small series and in an uncontrolled, highly individualized fashion, which, however, documented that high dose radiotherapy can, in principle, be used to achieve local control. Generally the radiation dose that is necessary for a curative approach can hardly be achieved with conventional photon radiotherapy in patients with non-resectable tumors that are usually located near radiosensitive critical organs such as the brain, the spine or the pelvis. In these cases particle Radiotherapy (proton therapy (PT)/heavy ion therapy (HIT) may offer a promising new alternative. Moreover, compared with photons, heavy ion beams provide a higher physical selectivity because of their finite depth coverage in tissue. They achieve a higher relative biological effectiveness. Phase I/II dose escalation studies of HIT in adults with non-resectable bone and soft tissue sarcomas have already shown favorable results.</p> <p>Methods/Design</p> <p>This is a monocenter, single-arm study for patients ≥ 6 years of age with non-resectable osteosarcoma. Desired target dose is 60-66 Cobalt Gray Equivalent (Gy E) with 45 Gy PT (proton therapy) and a carbon ion boost of 15-21 GyE. Weekly fractionation of 5-6 × 3 Gy E is used. PT/HIT will be administered exclusively at the Ion Radiotherapy Center in Heidelberg. Furthermore, FDG-PET imaging characteristics of non-resectable osteosarcoma before and after PT/HIT will be investigated prospectively. Systemic disease before and after PT/HIT is targeted by standard chemotherapy protocols and is not part of this trial.</p> <p>Discussion</p> <p>The primary objectives of this trial are the determination of feasibility and toxicity of HIT. Secondary objectives are tumor response, disease free survival and overall survival. The aim is to improve outcome for patients with non-resectable osteosarcoma.</p> <p>Trail Registration</p> <p>Registration number (ClinicalTrials.gov): NCT01005043</p
Tolerability of inhaled N-chlorotaurine in the pig model
<p>Abstract</p> <p>Background</p> <p>N-chlorotaurine, a long-lived oxidant produced by human leukocytes, can be applied in human medicine as an endogenous antiseptic. Its antimicrobial activity can be enhanced by ammonium chloride. This study was designed to evaluate the tolerability of inhaled N-chlorotaurine (NCT) in the pig model.</p> <p>Methods</p> <p>Anesthetized pigs inhaled test solutions of 1% (55 mM) NCT (n = 7), 5% NCT (n = 6), or 1% NCT plus 1% ammonium chloride (NH<sub>4</sub>Cl) (n = 6), and 0.9% saline solution as a control (n = 7), respectively. Applications with 5 ml each were performed hourly within four hours. Lung function, haemodynamics, and pharmacokinetics were monitored. Bronchial lavage samples for captive bubble surfactometry and lung samples for histology and electron microscopy were removed.</p> <p>Results</p> <p>Arterial pressure of oxygen (PaO<sub>2</sub>) decreased significantly over the observation period of 4 hours in all animals. Compared to saline, 1% NCT + 1% NH<sub>4</sub>Cl led to significantly lower PaO<sub>2 </sub>values at the endpoint after 4 hours (62 ± 9.6 mmHg vs. 76 ± 9.2 mmHg, p = 0.014) with a corresponding increase in alveolo-arterial difference of oxygen partial pressure (AaDO<sub>2</sub>) (p = 0.004). Interestingly, AaDO<sub>2 </sub>was lowest with 1% NCT, even lower than with saline (p = 0.016). The increase of pulmonary artery pressure (PAP) over the observation period was smallest with 1% NCT without difference to controls (p = 0.91), and higher with 5% NCT (p = 0.02), and NCT + NH<sub>4</sub>Cl (p = 0.05).</p> <p>Histological and ultrastructural investigations revealed no differences between the test and control groups. The surfactant function remained intact. There was no systemic resorption of NCT detectable, and its local inactivation took place within 30 min. The concentration of NCT tolerated by A549 lung epithelial cells <it>in vitro </it>was similar to that known from other body cells (0.25–0.5 mM).</p> <p>Conclusion</p> <p>The endogenous antiseptic NCT was well tolerated at a concentration of 1% upon inhalation in the pig model. Addition of ammonium chloride in high concentration provokes a statistically significant impact on blood oxygenation.</p
Neutral sphingomyelinase mediates the co-morbidity trias of alcohol abuse, major depression and bone defects
Mental disorders are highly comorbid and occur together with physical diseases, which are often considered to arise from separate pathogenic pathways. We observed in alcohol-dependent patients increased serum activity of neutral sphingomyelinase. A genetic association analysis in 456,693 volunteers found associations of haplotypes of SMPD3 coding for NSM-2 (NSM) with alcohol consumption, but also with affective state, and bone mineralisation. Functional analysis in mice showed that NSM controls alcohol consumption, affective behaviour, and their interaction by regulating hippocampal volume, cortical connectivity, and monoaminergic responses. Furthermore, NSM controlled bone–brain communication by enhancing osteocalcin signalling, which can independently supress alcohol consumption and reduce depressive behaviour. Altogether, we identified a single gene source for multiple pathways originating in the brain and bone, which interlink disorders of a mental–physical co-morbidity trias of alcohol abuse—depression/anxiety—bone disorder. Targeting NSM and osteocalcin signalling may, thus, provide a new systems approach in the treatment of a mental–physical co-morbidity trias
Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences
The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported
by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on
18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based
researchers who signed it in the short time span from 20 September to 6 October 2016
Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches
Extracellular vesicles (EVs), through their complex cargo, can reflect the state of their cell of origin and change the functions and phenotypes of other cells. These features indicate strong biomarker and therapeutic potential and have generated broad interest, as evidenced by the steady year-on-year increase in the numbers of scientific publications about EVs. Important advances have been made in EV metrology and in understanding and applying EV biology. However, hurdles remain to realising the potential of EVs in domains ranging from basic biology to clinical applications due to challenges in EV nomenclature, separation from non-vesicular extracellular particles, characterisation and functional studies. To address the challenges and opportunities in this rapidly evolving field, the International Society for Extracellular Vesicles (ISEV) updates its 'Minimal Information for Studies of Extracellular Vesicles', which was first published in 2014 and then in 2018 as MISEV2014 and MISEV2018, respectively. The goal of the current document, MISEV2023, is to provide researchers with an updated snapshot of available approaches and their advantages and limitations for production, separation and characterisation of EVs from multiple sources, including cell culture, body fluids and solid tissues. In addition to presenting the latest state of the art in basic principles of EV research, this document also covers advanced techniques and approaches that are currently expanding the boundaries of the field. MISEV2023 also includes new sections on EV release and uptake and a brief discussion of in vivo approaches to study EVs. Compiling feedback from ISEV expert task forces and more than 1000 researchers, this document conveys the current state of EV research to facilitate robust scientific discoveries and move the field forward even more rapidly
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