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NHC supersilyl silver complex [Ag(IPr)SitBu3] as a promising agent for substitution reactions
(2020)
The NHC supersilyl silver complex [Ag(IPr)SitBu3] (IPr = NHCIPr) was prepared by treatment of Ag(IPr)Cl with Na(thf)2[SitBu3] in benzene/thf at room temperature. X‐ray quality crystals of the NHC supersilyl silver complex [Ag(IPr)SitBu3] (monoclinic, space group P21/m) were grown from heptane at room temperature. The 29Si NMR spectrum of a solution of [Ag(IPr)SitBu3] in C6D6 revealed two doublets caused by coupling to 107Ag and 109Ag nuclei. We further investigated the possibility of a conversion of triel halides EX3 by treatment with [Ag(IPr)SitBu3]. At ambient temperature the reaction of [Ag(IPr)SitBu3] with an excess of EX3 yielded tBu3SiEX2 (E = B, Al; X = Cl, Br; E = Ga; X = Cl) and IPr·EX3 (EX3 = BCl3, BBr3, AlCl3, AlBr3, GaCl3). The identity of tBu3SiEX2 and IPr·EX3 was confirmed by comparison with authentic samples.
[1,3-Bis(2,6-diisopropylphenyl)-1,3-dihydro-2H-imidazol-2-ylidene]triiodoborane benzene hemisolvate
(2020)
Tailoring of spin state energetics of transition metal complexes and even the correct prediction of the resulting spin state is still a challenging task, both for the experimentalist and the theoretician. Apart from the complexity in the solid state imposed by packing effects, molecular factors of the spin state ordering are required to be identified and quantified on equal rights. In this work we experimentally record the spin states and SCO energies within an eight-member substitution-series of N4O2 ligated iron(II) complexes both in the solid state (SQUID magnetometry and single-crystal X-ray crystallography) and in solution (VT-NMR). The experimental survey is complemented
by exhaustive theoretical modelling of the molecular and electronic structure of the open-chain N4O2 family and its macrocyclic N6 congeners through density-functional theory methods. Ligand topology is identified as the leading factor defining ground-state multiplicity of the corresponding iron(II) complexes. Invariably the low-spin state is sterically trapped in the macrocycles, whereas subtle substitution effects allow for a molecular fine tuning of the spin state in the open-chain ligands. Factorization of computed relative SCO energies holds promise for directed design of future SCO systems.
Simple Summary
The interaction between tumors and immune cells influences tumor fate, i.e., regression, growth, or even metastases. The evaluation of tumor infiltrating lymphocytes (TILs) in human breast cancer has prognostic value. Pet rabbits develop spontaneous mammary carcinomas and have an immune system that is comparable with that of humans, so that they have the potential to provide an animal model for human breast cancer. To further substantiate this similarity, this study examined TILs in 107 pet rabbit mammary carcinomas according to criteria established for human breast cancer. For TIL evaluation routinely stained microscopic sections were examined by light microscopy. Relevant histological and immunohistochemical tumor characteristics were obtained from a data base. Results showed that increased presence of stromal TILs was statistically associated with histological tumor features indicative of a less aggressive biological behavior, i.e., reduced tumor cell proliferation and a lower histological grade. The expression by tumor cells of calponin, a presumed tumor suppressor protein, was also associated with their reduced proliferation and a higher percentage of stromal TILs. Data suggest that higher percentages of stromal TILs may have the potential to serve as favorable prognostic indicator in rabbit mammary carcinomas and support the value of pet rabbits for comparative research.
Abstract
Tumor infiltrating lymphocytes (TILs) serve as prognostic biomarker in human breast cancer. Rabbits have the potential to act as animal model for human breast cancer, and close similarities exist between the rabbit and human immune system. The aim of this study is to characterize TILs in pet rabbit mammary carcinomas and to statistically correlate results with histological and immunohistochemical tumor characteristics. Microscopic evaluation of TILs was performed in hematoxylin and eosin stained sections of 107 rabbit mammary carcinomas according to international guidelines for human breast cancer. Data on histological features of malignancy, estrogen and progesterone receptor status and calponin expression were obtained from the data base. This study revealed a statistical association between stromal TILs in the central tumor (CT) and infiltrative margin. Higher maximal percentages of stromal TILs at the CT were statistically correlated with decreased mitotic count and lower tumor grade. An increased number of calponin positive tumor cells was statistically associated with a lower mitotic count and a higher percentage of stromal TILs. Results suggest that higher percentages of stromal TILs are useful biomarkers that may point toward a favorable prognosis in rabbit mammary carcinomas and support the concept of the use of rabbits for translational research
The hidden burden of severe asthma: from patient perspective to new opportunities for clinicians
(2020)
Severe asthma is an important topic in respiratory diseases, due to its high impact on morbidity and mortality as well as on health-care resources. The many challenges that still exist in the management of the most difficult-to-treat forms of the disease, and the acknowledgement of the existence of unexplored areas in the pathophysiological mechanisms and the therapeutic targets represent an opportunity to gather experts in the field with the immediate goals to summarize current understanding about the natural history of severe asthma and to identify gaps in knowledge and research opportunities, with the aim to contribute to improved medical care and health outcomes. This article is a consensus document from the “International Course on Severe Asthma” that took place in Palermo, Italy, on May 10–11, 2019. Emerging topics in severe asthma were addressed and discussed among experts, with special focus on patient’s needs and research opportunities, with the aim to highlight the unanswered questions in the diagnostic process and therapeutic approach.
Obstructive Sleep Apnea is emerging as a global health epidemic, particularly due to the obesity pandemic. However, comprehensive prevalence data are still lacking and global OSA research has not yet been structurally evaluated. Using the latest comprehensive age/gender-specific BMI and obesity data, a global landscape estimating the risk/burden of OSA was created. Results were presented in relation to an in-depth analysis of OSA research and countries’ socioeconomic/scientific background. While the USA, Canada, and Japan are the highest publishing countries on OSA, Iceland, Greece, and Israel appeared at the forefront when relating the scientific output to socioeconomic parameters. Conversely, China, India, and Russia showed relatively low performances in these relations. Analysis of the estimated population at risk (EPR) of OSA showed the USA, China, India, and Brazil as the leading countries. Although the EPR and OSA research correlated strongly, major regional discrepancies between the estimated demand and actual research performances were identified, mainly in, but not limited to, developing nations. Our study highlights regional challenges/imbalances in the global activity on OSA and allows targeted measures to mitigate the burden of undiagnosed/untreated OSA. Furthermore, the inclusion of disadvantaged countries in international collaborations could stimulate local research efforts and provide valuable insights into the regional epidemiology of OSA.
Using a qualitative sampling approach to survey for Odonata along water systems inside and outside of four major protected areas in Southern Ghana (viz; Atewa Range Forest Reserve, Ankasa Forest Reserve, Owabi Wildlife Sanctuary and Bobiri Forest Reserve), a total of 66 Odonata species in seven families encompassing 28 Zygoptera and 38 Anisoptera were recorded. Libellulidae (n= 36) exhibited the highest number of species, followed by Coenagrionidae (n= 10), and Calopterygidae (n= 5). In considering the observed number of species exhibited by each protected area, the Atewa Range Forest Reserve exhibited the highest number of species (n= 51), followed by the Ankasa Forest Reserve (n= 47), the Owabi Wildlife Sanctuary (n= 44) and Bobiri Forest Reserve (n= 43). Disturbance tolerance species dominated in habitats outside the various forest reserves, whiles forest specialists predominated inside the reserves, indicating the quality of the forest cover therein.
Background: The feedback given to students plays an important role in their efficiency related to learning practical skills. In the present study, diverse feedback modalities have been investigated. Our hypothesis is that individualized and unsupervised video feedback can produce a similar learning experience as performing practical skills in an oral and maxillofacial surgery setting with conventional direct expert feedback (control group).
Methods: This prospective, randomized, controlled, and blinded study compared direct expert feedback (DEF), individualized video feedback (IVF) and unsupervised video feedback (UVF). The participants were fourth-year dental students from University Goethe in Frankfurt. The students were assigned to one of the three feedback methods (n = 20 per group) using simple randomization. All participants watched an instruction video for an interdental (‘Ernst’) ligature and periphery venous catheterization. Next, the students were video recorded performing the tasks by themselves (pre-test). Following this, every student received feedback using one of the above-mentioned feedback modalities. The participants then performed the same task again while being video recorded (post-test) to measure the acquired competence. Six weeks later, the students participated in an objective structured clinical examination (OSCE) to evaluate their long-term knowledge retention. All examiners were blinded regarding the students’ instructional approach and their affiliation in terms of the learning group.
Results: For the interdental ligature, we found significant improvements in performance in each feedback modality group between the pre-test and post-test (p < 0.001). UVF had the strongest effect on performance time. The comparison between each group in the post-test showed no significant differences between the three groups.
Conclusion: This study showed that IVF and UVF can be considered an alternative or adjunct to conventional methods (i.e. DEF) when learning procedural skills in oral and maxillofacial surgery. However, DEF showed to be the most effective method of feedback and therefore preferable in teaching.
Background: Recent advances in 3D printing technology have enabled the emergence of new educational and clinical tools for medical professionals. This study provides an exemplary description of the fabrication of 3D‐printed individualised patient models and assesses their educational value compared to cadaveric models in oral and maxillofacial surgery.
Methods: A single‐stage, controlled cohort study was conducted within the context of a curricular course. A patient's CT scan was segmented into a stereolithographic model and then printed using a fused filament 3D printer. These individualised patient models were implemented and compared against cadaveric models in a curricular oral surgery hands‐on course. Students evaluated both models using a validated questionnaire. Additionally, a cost analysis for both models was carried out. P‐values were calculated using the Mann‐Whitney U test.
Results: Thirty‐eight fourth‐year dental students participated in the study. Overall, significant differences between the two models were found in the student assessment. Whilst the cadaveric models achieved better results in the haptic feedback of the soft tissue, the 3D‐printed individualised patient models were regarded significantly more realistic with regard to the anatomical correctness, the degree of freedom of movement and the operative simulation. At 3.46 € (compared to 6.51 €), the 3D‐printed patient individualised models were exceptionally cost‐efficient.
Conclusions: 3D‐printed patient individualised models presented a realistic alternative to cadaveric models in the undergraduate training of operational skills in oral and maxillofacial surgery. Whilst the 3D‐printed individualised patient models received positive feedback from students, some aspects of the model leave room for improvement.
Purpose: To investigate cortical thickness and cortical quantitative T2 values as imaging markers of microstructural tissue damage in patients with unilateral high-grade internal carotid artery occlusive disease (ICAOD).
Methods: A total of 22 patients with ≥70% stenosis (mean age 64.8 years) and 20 older healthy control subjects (mean age 70.8 years) underwent structural magnetic resonance imaging (MRI) and high-resolution quantitative (q)T2 mapping. Generalized linear mixed models (GLMM) controlling for age and white matter lesion volume were employed to investigate the effect of ICAOD on imaging parameters of cortical microstructural integrity in multivariate analyses.
Results: There was a significant main effect (p < 0.05) of the group (patients/controls) on both cortical thickness and cortical qT2 values with cortical thinning and increased cortical qT2 in patients compared to controls, irrespective of the hemisphere. The presence of upstream carotid stenosis had a significant main effect on cortical qT2 values (p = 0.01) leading to increased qT2 in the poststenotic hemisphere, which was not found for cortical thickness. The GLMM showed that in general cortical thickness was decreased and cortical qT2 values were increased with increasing age (p < 0.05).
Conclusion: Unilateral high-grade carotid occlusive disease is associated with widespread cortical thinning and prolongation of cortical qT2, presumably reflecting hypoperfusion-related microstructural cortical damage similar to accelerated aging of the cerebral cortex. Cortical thinning and increase of cortical qT2 seem to reflect different aspects and different pathophysiological states of cortical degeneration. Quantitative T2 mapping might be a sensitive imaging biomarker for early cortical microstructural damage.
Rational agency is of central interest to philosophy, with evolutionary accounts of the cognitive underpinnings of rational agency being much debated. Yet one building block—our ability to argue—is less studied, except Mercier and Sperber’s argumentative theory (Mercier and Sperber in Behav Brain Sci 34(02):57–74, https://doi.org/10.1017/s0140525x10000968 [Titel anhand dieser DOI in Citavi-Projekt übernehmen] , 2011, in The enigma of reason. Harvard University Press, Cambridge, 2017). I discuss their account and argue that it faces a lacuna: It cannot explain the origin of argumentation as a series of small steps that reveal how hominins with baseline abilities of the trait in question could turn into full-blown owners of it. This paper then provides a first sketch of the desired evolutionary trajectory. I argue that reasoning coevolves with the ability to coordinate behavior. After that, I establish a model based on niche construction theory. This model yields a story with following claims. First, argumentation came into being during the Oldowan period as a tool for justifying information ‘out of sight’. Second, argumentation enabled hominins to solve collective action problems with collaborators out of sight, which stabilized argumentative practices eventually. Archeological findings are discussed to substantiate both claims. I conclude with outlining changes resultant from my model for the concept of rational agency.
Explaining humans as rational creatures—capable of deductive reasoning—remains challenging for evolutionary naturalism. Schechter (Philosophical Perspectives, 24(1)437–464, 2011, 2013) proposes to link the evolution of this kind of reasoning with the ability to plan. His proposal, however, does neither include any elaborated theory on how logical abilities came into being within the hominin lineage nor is it sufficiently supported by empirical evidence. I present such a theory in broad outline and substantiate it with archeological findings. It is argued that the cognitive makeup of any animal is constituted by being embedded in a certain way of life. Changing ways of life thus foster appearances of new cognitive abilities. Finally, a new way of life of coordinated group behavior emerged within the hominins: anticipatory group planning involved in activities like making sophisticated spears for hunting. This gave rise to human logical cognition. It turned hominins into domain-general reasoner and adherents of intersubjective norms for reasoning. However, as I argue, it did not—and most likely could not—give rise to reason by deductive logic. More likely, deductive reasoning entered our world only a few thousand years ago: exclusively as a cultural artifact.
Introns of human transfer RNA precursors (pre-tRNAs) are excised by the tRNA splicing endonuclease TSEN in complex with the RNA kinase CLP1. Mutations in TSEN/CLP1 occur in patients with pontocerebellar hypoplasia (PCH), however, their role in the disease is unclear. Here, we show that intron excision is catalyzed by tetrameric TSEN assembled from inactive heterodimers independently of CLP1. Splice site recognition involves the mature domain and the anticodon-intron base pair of pre-tRNAs. The 2.1-Å resolution X-ray crystal structure of a TSEN15–34 heterodimer and differential scanning fluorimetry analyses show that PCH mutations cause thermal destabilization. While endonuclease activity in recombinant mutant TSEN is unaltered, we observe assembly defects and reduced pre-tRNA cleavage activity resulting in an imbalanced pre-tRNA pool in PCH patient-derived fibroblasts. Our work defines the molecular principles of intron excision in humans and provides evidence that modulation of TSEN stability may contribute to PCH phenotypes.
Diplura is a group of entognathous hexapods, often considered a sister group to insects. They play an important role in recycling organic matter in soil and subterranean terrestrial ecosystems. The Campodeidae is the most diverse family, divided into four subfamilies. The subfamily Plusiocampinae has a subterranean life-style with many species distributed in the Euro-Mediterranean area. The incertae sedis tachycampoids ("lignée Tachycampoïde") is a group within the family Campodeidae that share with the Plusiocampinae a strong preference for subterranean habitats and several morphological characters, such as slender body shape, elongated appendages, considerable increment in the number of antennomeres and cercal articles, and complexity of sensorial structures. The present monograph provides a taxonomic revision of the subfamily Plusiocampinae and the genera belonging to the tachycampoid lineage from Europe and the Mediterranean region. It comprises detailed morphological descriptions and illustrations together with data on the habitats and distributions of 87 species, 10 subspecies and 11 affinis forms. Seven new species are described among those, namely: Plusiocampa (Plusiocampa) apollo Sendra, Giachino & Vailati sp. nov., P. (P.) chiosensis Sendra & Gasparo sp. nov., P. (P.) dublanskii Sendra & Turbanov sp. nov., P. (P.) hoffmanni Sendra & Paragamian sp. nov., P. (P.) rhea Sendra sp. nov., P. (P.) ternovensis Sendra & Borko sp. nov. and P. (Venetocampa) ferrani Sendra & Delić sp. nov.
Campodeinae is the most diverse subfamily of Campodeidae diplurans and inhabits soils and subsurface ecosystems. These are distributed in the Palearctic area, clearly rarifying towards northern latitudes. The major taxonomic characters are chaetotaxy, shape and complexity of pretarsal structures, and secondary sexual characters. This monograph provides a taxonomic revision of the subfamily Campodeinae in the Euro-Mediterrnean region, based on extensive literature review and new material studied. It comprises detailed morphological descriptions and illustrations together with habitat and distribution data of 161 species and 14 subspecies from 10 genera: Campodea Westwood, 1842, Edriocampa Silvestri, 1933, Eutrichocampa Silvestri, 1902, Helladocampa Condé, 1984, Libanocampa Condé, 1955, Litocampa Silvestri, 1933, Oreocampa Condé, 1950, Podocampa Silvestri, 1932, Remycampa Condé 1952, and Spaniocampa Silvestri, 1933. With 116 species Campodea is the most diverse and widely distributed genus in the studied area.
Purpose: In this study, we examined distress levels and quality of life (QoL) of patients with hematologic malignancies under treatment in an acute setting. We used external- and self-assessment instruments for distress. Additionally, we investigated the relation between distress and QoL as well as whether highly distressed patients differed from less distressed patients concerning their QoL.
Methods: A cross-sectional study with patients of the Medical Clinic II of the University Hospital Frankfurt was conducted. One hundred and nine patients were assessed with an expert rating scale and completed self-report questionnaires. Data were exploratively analyzed and group comparisons between patients who scored above the cut-off of the respective screening instruments and those who did not were conducted.
Results: Patients with hematologic malignancies experience high levels of distress and low QoL. Especially, role and social functioning are affected. Patients suffer most from fatigue, appetite loss, and insomnia. Using established cut-offs, all screening instruments were able to differentiate between patients regarding distress and QoL. Patients scoring above the cut-off were significantly more distressed and had a lower QoL. There was a medium-to-strong correlation between distress and QoL indicators.
Conclusion: Cancer-specific screening instruments seem to be able to identify treatment needs more specifically. They also allowed a better differentiation concerning QoL. The close link between distress and QoL needs to be recognized to enable a holistic approach to treatment and thereby optimize the quality of treatment.
Objective: To explore and describe exposure to suicidality in healthcare providers (HCP) working with oncological patients. Special emphasis was put on five central aspects from the HCPs perspective: Exposure, Confidence, Expertise, Distress, and Education.
Methods: A 48‐item online questionnaire was developed and distributed to HCPs working with cancer patients. Three hundred fifty‐four answered questionnaires were analyzed.
Results: Overall 83.3% of HCPs reported to have encountered at least one suicidal patient in the last year. Feeling confident in talking about suicidality was reported by 72.1% of HCPs, with 71.2% of nurses reporting feeling insecure compared with only 5.1% of psychotherapists. Similarly, 22.3% of HCPs felt overwhelmed when confronted with a patient who substantiated his suicidality during consultation. A lack of personal knowledge concerning suicidality in general and in oncological patients in particular, was reported by 39.6% and 49.8%, respectively. In total, 88.1% of HCPs reported feeling distressed when confronted with suicidality, while 81.1% of participants wanted further education regarding suicidality in cancer patients despite that 73.2% had already received some sort of psycho‐oncology education.
Conclusions: Despite the well‐documented fact of elevated suicide rates in cancer patients, there remain deficits in knowledge, which induce feelings of insecurity and helplessness in HCPs. There is a demand for further education concerning the treatment of suicidal cancer patients. Therefore, special curricula addressing this topic should be devised. A general debate about suicidality in cancer patients could help raise awareness of this problem and generate means of prevention.
Background: With refinements in diagnosis and therapy of gliomas, the importance of survival time as the sole outcome parameter has decreased, and patient-centered outcome parameters have gained interest. Pursuing a profession is an indispensable component of human happiness. The aim of this study was to analyze the professional outcomes besides their neuro-oncological and functional evaluation after surgery for gliomas in eloquent areas.
Methods: We assessed neuro-oncological and functional outcomes of patients with gliomas WHO grades II and III undergoing surgery between 2012 and 2018. All patients underwent routine follow-up and adjuvant treatment. Treatment and survival parameters were collected prospectively. Repercussions of the disease on the patients’ professional status, socio-economic situation, and neurocognitive function were evaluated retrospectively with questionnaires.
Results: We analyzed data of 58 patients with gliomas (WHO II: 9; III: 49). Median patient age was 35.8 years (range 21–63 years). Awake surgery techniques were applied in 32 patients (55.2%). Gross total and subtotal tumor resections were achieved in 33 (56.9%) and 17 (29.3%) patients, respectively, whereas in 8 patients (13.8%) resection had to remain partial. Most patients (n = 46; 79.3%) received adjuvant treatment. Median follow up was 43.8 months (range 11–82 months). After treatment 41 patients (70.7%) were able to resume a working life. Median time until returning to work was 8.0 months (range 0.2–22.0 months). To be younger than 40 at the time of the surgery was associated with a higher probability to return to work (p < .001). Multivariable regression analysis showed that patient age < 40 years as well as occupational group and self-reported fatigue were factors independently associated with the ability to return to work.
Conclusion: The ability to resume professional activities following brain tumor surgery is an important patient-oriented outcome parameter. We found that the majority of patients with gliomas were able to return to work following surgical and adjuvant treatment. Preservation of neurological function is of utmost relevance for individual patients´ quality of life.
In this thesis different descriptions for the non-Abelian Landau-Pomeranchuk-Migdal (LPM) effect are studied within the partonic transport approach BAMPS (Boltzmann Approach to Multi-Parton Scatterings), which numerically solves the 3+1-dimensional Boltzmann equation for massless partons based on elastic and radiative interactions calculated in perturbative quantum chromodynamics.
The LPM effect is a coherence effect originating from the finite formation time of gluon emissions leading to characteristic dependencies of the radiative energy loss of energetic partonic projectiles, as e.g. jets in ultra-relativistic heavy-ion collisions.
Due to this non-locality of interactions, such coherence effects are difficult to describe rigorously in transport theory.
Therefore we compare in this work three different implementations for the LPM effect: i) a parametric LPM suppression based on a theta function in the radiative matrix elements, ii) a stochastic LPM approach, which explicitly simulates the elastic interactions of gluons during their formation time, and iii) the thermal gluon emission rate from the AMY formalism, which is a hard-thermal-loop calculation exactly considering the non-Abelian LPM effect by resumming ladder diagrams in the large medium limit.
After discussing the numerical implementation of the three approaches, we investigate their consequences in different jet-energy loss scenarios: first the academic scenarios of eikonal and non-eikonal jets flying through a static brick of thermal quark-gluon plasma and then jets traversing the expanding medium of ultra-relativistic heavy-ion collisions at LHC energies.
We can demonstrate that although the different LPM approaches show similarities in the radiative energy loss there are differences in the underlying gluon emission spectra, which originate from the specific treatment of divergences in the matrix elements within BAMPS.
Furthermore, based on the different LPM approaches we present simulation results for recent jet quenching observables from the LHC experiments and discuss properties of the underlying heavy-ion medium.