Chemical bonding in phase-change chalcogenides.

Almost all phase-change memory materials (PCM) contain chalcogen atoms, and their chemical bonds have been denoted both as ``electron-deficient'' [sometimes referred to as ``metavalent''] and ``electron-rich'' [``hypervalent'', multicentre]. The latter involve lone-pair electrons. We have performed calculations that can discriminate unambiguously between these two classes of bond and have shown that PCM have electron-rich, 3c-4e (``hypervalent'') bonds. Plots of charge transferred between ($ET$) and shared with ($ES$) neighbouring atoms cannot on their own distinguish between ``metavalent'' and ``hypervalent'' bonds, both of which involve single-electron bonds. PCM do not exhibit ``metavalent'' bonding and are not electron-deficient; the bonding is electron-rich of the ``hypervalent'' or multicentre type. .

Extending the new era of genomic testing into pregnancy management: A proposed model for Australian prenatal services.

BACKGROUND: Trio exome sequencing can be used to investigate congenital abnormalities identified on pregnancy ultrasound, but its use in an Australian context has not been assessed. AIMS: Assess clinical outcomes and changes in management after expedited genomic testing in the prenatal period to guide the development of a model for widespread implementation. MATERIALS AND METHODS: Forty-three prospective referrals for whole exome sequencing, including 40 trios (parents and pregnancy), two singletons and one duo were assessed in a tertiary hospital setting with access to a state-wide pathology laboratory. Diagnostic yield, turn-around time (TAT), gestational age at reporting, pregnancy outcome, change in management and future pregnancy status were assessed for each family. RESULTS: A clinically significant genomic diagnosis was made in 15/43 pregnancies (35%), with an average TAT of 12 days. Gestational age at time of report ranged from 16 + 5 to 31 + 6 weeks (median 21 + 3 weeks). Molecular diagnoses included neuromuscular and skeletal disorders, RASopathies and a range of other rare Mendelian disorders. The majority of families actively used the results in pregnancy decision making as well as in management of future pregnancies. CONCLUSIONS: Rapid second trimester prenatal genomic testing can be successfully delivered to investigate structural abnormalities in pregnancy, providing crucial guidance for current and future pregnancy management. The time-sensitive nature of this testing requires close laboratory and clinical collaboration to ensure appropriate referral and result communication. We found the establishment of a prenatal coordinator role and dedicated reporting team to be important facilitators. We propose this as a model for genomic testing in other prenatal services.

Highly Contorted Rigid Nitrogen-Rich Nanographene with Four Heptagons.

Nucleophilic substitution of 9,10-dichlorooctafluoroanthracene with 3,4-diethylpyrrole and subsequent Scholl reaction give the annularly fused decapyrrollyl anthracene. Single crystal X-ray analysis revealed a highly contorted geometry induced by a combination of adjacent heptagons, forming a unique 7-7-6-7-7 topology. The end-to-end twist angle along the acene moiety is 90°. Cyclic voltammetry studies reveal 6-electron oxidation waves. Density functional theory calculations provided further insights into the aromaticity and electronic properties of this highly twisted, nitrogen-rich nanographene. The structural rigidity and high racemization energy barrier have been studied theoretically and experimentally by VT-NMR.

[Functional outcomes and return to sports, work, and daily activities after revision UKA compared to primary UKA and TKA]. / Funktionelle Ergebnisse und Wiederaufnahme von Sport, Arbeit und Alltagsaktivitäten nach Revision eines Monoschlittens im Vergleich zur Primärimplantation eines Mono- und Doppelschlittens.

BACKGROUND: Unicompartmental knee arthroplasty (UKA), in addition to total knee arthroplasty (TKA), has been shown to be effective in the surgical treatment of knee osteoarthritis with appropriate patient selection. In clinical studies, it has demonstrated superior functional results with lower complication rates. In clinical practice, these advantages must be weighed against the disadvantage of an increased revision rate, especially in younger patients with sports and work activities. OBJECTIVES: The aim of this study was to compare the functional outcome as well as the time to return to daily activities, work, and sports after revision of UKA to TKA with those of primary UKA and primary TKA using a matched-pair analysis. MATERIALS AND METHODS: The study was based on a matched-pair analysis at two defined time points, always comparing 28 patients who underwent either revision of a UKA to a TKA, primary UKA, or primary TKA. Patients completed the Oxford Knee Score, UCLA score, Knee Society score, and WOMAC score during standardized follow-up. In addition, postoperative patient satisfaction and return to activities of daily living, work, and sports were recorded in a standardized manner, and a clinical examination was performed. RESULTS: The four functional scores studied showed a common trend in favor of UKA, followed by primary TKA and revision TKA. The differences between converted UKA and primary TKA were not significant. However, at 3.2 years after the last surgery, the results of the converted UKA were significantly lower than those of the primary UKA. Return to work and sports tended to occur the earliest after UKA, followed by TKA and the revision group. All groups showed a tendency to engage in low-impact sports. CONCLUSION: The functional results of revised UKA were significantly inferior to those of primary UKA based on a 3-year follow-up. Return to work, sports, and activities of daily living tended to take longer after revision than after primary implantation of either a UKA or a TKA.

Management after acute injury of the anterior cruciate ligament (ACL). Part 3: Recommendation on surgical treatment.

PURPOSE: The aim of this consensus project was to give recommendations regarding surgical treatment of the anterior cruciate ligament (ACL) injured patient. METHODS: For this consensus process, an expert, steering and rating group was formed. In an initial online meeting, the steering group, together with the expert group, formed various key topic complexes for which multiple questions were formulated. For each key topic, a structured literature search was performed by the steering group. The results of the literature review were sent to the rating group with the option to give anonymous comments until a final consensus voting was performed. Sufficient consensus was defined as 80% agreement. RESULTS: During this consensus process, 30 topics regarding the surgical management and technique of ACL reconstruction were identified. The literature search for each key question resulted in 30 final statements. Of these 30 final statements, all achieved consensus. CONCLUSIONS: This consensus process has shown that surgical treatment of ACL injury is a complex process. Various surgical factors influence patient outcomes. The proposed treatment algorithm can be used as a decision aid for the surgeon. LEVEL OF EVIDENCE: Level V.

Follow-up Treatment after Cartilage Therapy of the Knee Joint - a Recommendation of the DGOU Clinical Tissue Regeneration Working Group. / Nachbehandlung nach Knorpeltherapie am Kniegelenk ­ eine Empfehlung der AG Klinische Geweberegeneration der DGOU.

The first follow-up treatment recommendation from the DGOU's Clinical Tissue Regeneration working group dates back to 2012. New scientific evidence and changed framework conditions made it necessary to update the follow-up treatment recommendations after cartilage therapy.As part of a multi-stage member survey, a consensus was reached which, together with the scientific evidence, provides the basis for the present follow-up treatment recommendation.The decisive criterion for follow-up treatment is still the defect localisation. A distinction is made between femorotibial and patellofemoral defects. In addition, further criteria regarding cartilage defects are now also taken into account (stable cartilage edge, location outside the main stress zone) and the different methods of cartilage therapy (e. g. osteochondral transplantation, minced cartilage) are discussed.The present updated recommendation includes different aspects of follow-up treatment, starting with early perioperative management through to sports clearance and resumption of contact sports after cartilage therapy has taken place.

Investigation of sRNA-mRNA Interactions in Bacillus subtilis In Vivo.

In this chapter, we describe in vivo methods for the analysis of interactions between an sRNA and its target mRNA in B. subtilis. All these methods have been either established or significantly improved in our group and successfully employed to characterize a number of sRNA/target mRNA systems in Bacillus subtilis. Whereas in Chap. 8, we describe a combination of in vitro methods, e.g., EMSA and RNA secondary structure probing, we focus here on the investigation of RNA-RNA interactions in vivo using compatible plasmids or chromosomal insertions and deletions, the elucidation of the mechanisms of action of regulatory sRNAs employing transcriptional and translational reporter gene fusions, as well as the determination of expression profiles, half-lives of sRNA and mRNA, and their intracellular concentrations, and, finally, the investigation of RNA chaperones that promote the sRNA/mRNA interaction. For an in-depth analysis of sRNA-mRNA interactions in B. subtilis, a combination of in vivo and in vitro methods should be applied.

In Vitro Methods for the Investigation of sRNA-mRNA Interactions in Bacillus subtilis.

So far, in Bacillus subtilis, only four trans-encoded and 11 cis-encoded sRNAs and their targets have been investigated in detail, the majority of them in our group (rev. in 1, 2). Here, we describe in vitro methods for the analysis of sRNA/mRNA interactions. All these methods have been either elaborated or significantly improved in our group and successfully applied to characterize a number of sRNA/target mRNA systems in Bacillus subtilis for which we provide examples from our own work. The in vitro methods comprise the synthesis and purification of labeled and unlabeled RNA, the analysis of sRNA/mRNA interactions in electrophoretic mobility shift assays (EMSAs) including the calculation of their apparent binding rate constants (kapp) and equilibrium dissociation constants (Kd), the localization of minimal regulatory regions of an sRNA, the determination of the secondary structures of both interacting RNAs and their complex as well as the analysis of RNA chaperones that may promote the sRNA/mRNA interaction.

[Shoulder-clinical introduction]. / Schultergelenk ­ klinische Einführung.

BACKGROUND: Radiological imaging plays a significant role in the diagnostics of shoulder pathologies. Based on a patient's medical history, physical examination and radiological imaging, it is possible to plan the further conservative or surgical treatment. OBJECTIVES: Common pathologies of the shoulder and the correct radiological imaging are presented. CONCLUSIONS: A rational and targeted use of radiological imaging, together with the medical history and physical examination allows correct diagnosis of pathologies of the shoulder joint.

A comprehensive study of the interactions in the B. subtilis degradosome with special emphasis on the role of the small proteins SR1P and SR7P.

Here, we employ coelution experiments and far-western blotting to identify stable interactions between the main components of the B. subtilis degradosome and the small proteins SR1P and SR7P. Our data indicate that B. subtilis has a degradosome comprising at least RNases Y and PnpA, enolase, phosphofructokinase, glycerol-3-phosphate dehydrogenase GapA, and helicase CshA that can be co-purified without cross-linking. All interactions were corroborated by far-western blotting with proteins purified from E. coli. Previously, we discovered that stress-induced SR7P binds enolase to enhance its interaction with and activity of enolase-bound RNase Y (RnY), while SR1P transcribed under gluconeogenic conditions interacts with GapA to stimulate its interaction with and the activity of RnjA (RnjA). We show that SR1P can directly bind RnjA, RnY, and PnpA independently of GapA, whereas SR7P only interacts with enolase. Northern blotting suggests that the degradation of individual RNAs in B. subtilis under gluconeogenic or stress conditions depends on either RnjA or RnY alone or on RnjA-SR1P, RnY-SR1P, or RnY-Eno. In vitro degradation assays with RnY or RnjA substrates corroborate the in vivo role of SR1P. Currently, it is unknown which substrate property is decisive for the utilization of one of the complexes.

Gene-expression profiling of laser-dissected islets and studies in deficient mice reveal chemokines as differential driving force of type 1 diabetes.

Although type 1 diabetes (T1D) results from the autoimmune destruction of the insulin-producing ß-cells, its treatment is largely restricted to exogenous insulin administration. Only few therapies targeting the autoaggressive immune system have been introduced into clinical practice or are considered in clinical trials. Here, we provide a gene expression profile of the islet microenvironment obtained by laser-dissection microscopy in an inducible mouse model. Thereby, we have identified novel targets for immune intervention. Increased gene expression of most inflammatory proteins was apparent at day 10 after T1D induction and largely paralleled the observed degree of insulitis. We further focused on genes involved in leukocyte migration, including chemokines and their receptors. Besides the critical chemokine CXCL10, we found several other chemokines upregulated locally in temporary or chronic manner. Localization of the chemokine ligand/receptor pairs to the islet microenvironment has been confirmed by RNAscope. Interference with the CXCL16-CXCR6 and CX3CL1-CX3CR1 axes, but not the CCL5-CCR1/3/5 axis, resulted in reduced insulitis and lower T1D incidence. Further, we found that the receptors for the differentially expressed chemokines CXCL10, CXCL16 and CX3CL1 are distributed unevenly among islet autoantigen-specific T cells, which explains why the interference with just one chemokine axis cannot completely abrogate insulitis and T1D.

Quantum Chemical Similarities of Bonding in Polyiodides and Phase-Change Materials.

Covalent chemical bonding beyond the two-center two-electron (2c-2e) bond is well-known for (inter)halogenic compounds, in particular, electron-rich multicenter (or hypervalent) bonding of the three-center four-electron (3c-4e) type to explain both their structure and stability. In the present work, we examine different solid-state polyiodides by combining both local orbital wave function and projected force constant analysis in order to numerically quantify the influence of multicenter (hypervalent) bonding based on periodic density functional theory (DFT) calculations. After linking our findings to established qualitative theories on multicenter bonding, particularly, Alcock's "secondary" bonding, we relate the bonding behavior in polyiodides to industrially relevant phase-change materials of the Ge-Sb-Te class, finding further evidence for the same underlying cause as regards chemical bonding in both material classes.

The small-molecule kinase inhibitor ceritinib, unlike imatinib, causes a significant disturbance of lipid membrane integrity: A combined experimental and MD study.

Ceritinib and imatinib are small-molecule protein kinase inhibitors which are applied as therapeutic agents against various diseases. The fundamentals of their clinical use, i.e. their pharmacokinetics as well as the mechanisms of the inhibition of the respective kinases, are relatively well studied. However, the interaction of the drugs with membranes, which can be a possible cause of side effects, has hardly been investigated so far. Therefore, we have characterized the interaction of both drugs with lipid membranes consisting of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) in the absence and in the presence of cholesterol. For determining the membrane impact of both drugs on a molecular level, different experimental (NMR, ESR, fluorescence) and theoretical (MD simulations) approaches were applied. The data show that ceritinib, in contrast to imatinib, interacts more effectively with membranes significantly affecting various physico-chemical membrane parameters like membrane order and transmembrane permeation of polar solutes. The pronounced membrane impact of ceritinib can be explained by a strong affinity of the drug towards POPC which competes with the POPC-cholesterol interaction by that attenuating the ordering effect of cholesterol. The data are relevant for understanding putative toxic and cytotoxic side effects of these drugs such as the triggering of cell lysis or apoptosis.

Texaphyrin-Based Calcium Sensor for Multimodal Imaging.

The ability to monitor intracellular calcium concentrations using fluorescent probes has led to important insights into biological signaling processes at the cellular level. An important challenge is to relate such measurements to broader patterns of signaling across fields of view that are inaccessible to optical techniques. To meet this need, we synthesized molecular probes that couple calcium-binding moieties to lanthanide texaphyrins, resulting in complexes endowed with a diverse complement of magnetic and photophysical properties. We show that the probes permit intracellular calcium levels to be assessed by fluorescence, photoacoustic, and magnetic resonance imaging modalities and that they are detectable by multimodal imaging in brain tissue. This work thus establishes a route for monitoring signaling processes over a range of spatial and temporal scales.

Natamycin interferes with ergosterol-dependent lipid phases in model membranes.

Natamycin is an antifungal polyene macrolide that is used as a food preservative but also to treat fungal keratitis and other yeast infections. In contrast to other polyene antimycotics, natamycin does not form ion pores in the plasma membrane, but its mode of action is poorly understood. Using nuclear magnetic resonance (NMR) spectroscopy of deuterated sterols, we find that natamycin slows the mobility of ergosterol and cholesterol in liquid-ordered (Lo) membranes to a similar extent. This is supported by molecular dynamics (MD) simulations, which additionally reveal a strong impact of natamycin dimers on sterol dynamics and water permeability. Interference with sterol-dependent lipid packing is also reflected in a natamycin-mediated increase in membrane accessibility for dithionite, particularly in bilayers containing ergosterol. NMR experiments with deuterated sphingomyelin (SM) in sterol-containing membranes reveal that natamycin reduces phase separation and increases lipid exchange in bilayers with ergosterol. In ternary lipid mixtures containing monounsaturated phosphatidylcholine, saturated SM, and either ergosterol or cholesterol, natamycin interferes with phase separation into Lo and liquid-disordered (Ld) domains, as shown by NMR spectroscopy. Employing the intrinsic fluorescence of natamycin in ultraviolet-sensitive microscopy, we can visualize the binding of natamycin to giant unilamellar vesicles (GUVs) and find that it has the highest affinity for the Lo phase in GUVs containing ergosterol. Our results suggest that natamycin specifically interacts with the sterol-induced ordered phase, in which it disrupts lipid packing and increases solvent accessibility. This property is particularly pronounced in ergosterol containing membranes, which could underlie the selective antifungal activity of natamycin.

Synthesis and Characterization of Iron Bispyridine Bisdicyanamide, Fe[C5H5N]2[N(CN)2]2.

Fe[C5H5N]2[N(CN)2]2 (1) was synthesized from a reaction of stoichiometric amounts of NaN(CN)2 and FeCl2·4H2O in a methanol/pyridine solution. Single-crystal and powder diffraction show that 1 crystallizes in the monoclinic space group I2/m (no. 12), different from Mn[C5H5N]2[N(CN)2]2 (P21/c, no. 14) due to tilted pyridine rings, with a = 7.453(7) Å, b = 13.167(13) Å, c = 8.522(6) Å, ß = 114.98(6)° and Z = 2. ATR-IR, AAS, and CHN measurements confirm the presence of dicyanamide and pyridine. Thermogravimetric analysis shows that π-stacking interactions of the pyridine rings play an important role in structural stabilization. Based on DFT-optimized structures, a chemical bonding analysis was performed using a local-orbital framework by projection from a plane-wave basis. The resulting bond orders and atomic charges are in good agreement with the expectations based on the structure analysis. SQUID magnetic susceptibility measurements show a high-spin state FeII compound with predominantly antiferromagnetic exchange interactions at lower temperatures.

Binding of Nitriles and Isonitriles to V(III) and Mo(III) Complexes: Ligand vs Metal Controlled Mechanism.

The synthesis and structures of nitrile complexes of V(N[tBu]Ar)3, 2 (Ar = 3,5-Me2C6H3), are described. Thermochemical and kinetic data for their formation were determined by variable temperature Fourier transform infrared (FTIR), calorimetry, and stopped-flow techniques. The extent of back-bonding from metal to coordinated nitrile indicates that electron donation from the metal to the nitrile plays a less prominent role for 2 than for the related complex Mo(N[tBu]Ar)3, 1. Kinetic studies reveal similar rate constants for nitrile binding to 2, but the activation parameters depend critically on the nature of R in RCN. Activation enthalpies range from 2.9 to 7.2 kcal·mol-1, and activation entropies from -9 to -28 cal·mol-1·K-1 in an opposing manner. Density functional theory (DFT) calculations provide a plausible explanation supporting the formation of a π-stacking interaction between a pendant arene of the metal anilide of 2 and the arene substituent on the incoming nitrile in favorable cases. Data for ligand binding to 1 do not exhibit this range of activation parameters and are clustered in a small area centered at ΔH‡ = 5.0 kcal·mol-1 and ΔS‡ = -26 cal·mol-1·K-1. Computational studies are in agreement with the experimental data and indicate a stronger dependence on electronic factors associated with the change in spin state upon ligand binding to 1.

Porcine spermadhesin AQN-3 binds to negatively charged phospholipids.

The spermadhesin AQN-3 is a major component of porcine seminal plasma. While various studies suggest that this protein binds to boar sperm cells, its attachment to the cells is poorly understood. Therefore, the capacity of AQN-3 to interact with lipids was investigated. For that purpose, AQN-3 was recombinantly expressed in E. coli and purified via the included His-tag. Characterizing the quaternary structure by size exclusion chromatography revealed that recombinant AQN-3 (recAQN-3) is largely present as multimer and/or aggregate. To determine the lipid specificity of recAQN-3, a lipid stripe method and a multilamellar vesicle (MLV)-based binding assay were used. Both assays show that recAQN-3 selectively interacts with negatively charged lipids, like phosphatidic acid, phosphatidylinositol phosphates, and cardiolipin. No interaction was observed with phosphatidylcholine, sphingomyelin, phosphatidylethanolamine, or cholesterol. The affinity to negatively charged lipids can be explained by electrostatic interactions because binding is partly reversed under high-salt condition. However, more factors have to be assumed like hydrogen bonds and/or hydrophobic forces because the majority of bound molecules was not released by high salt. To confirm the observed binding behavior for the native protein, porcine seminal plasma was incubated with MLVs comprising phosphatidic acid or phosphatidyl-4,5-bisphosphate. Attached proteins were isolated, digested, and analyzed by mass spectrometry. Native AQN-3 was detected in all samples analyzed and was - besides AWN - the most abundant protein. It remains to be investigated whether AQN-3, together with other sperm associated seminal plasma proteins, acts as decapacitation factor by targeting negative lipids with signaling or other functional roles in fertilization.

Etiology, Classification, Diagnostics, and Conservative Management of Osteochondral Lesions of the Talus. 2023 Recommendations of the Working Group "Clinical Tissue Regeneration" of the German Society of Orthopedics and Traumatology.

METHODS: Peer-reviewed literature was analyzed regarding different topics relevant to osteochondral lesions of the talus (OLTs) treatment. This process concluded with a statement for each topic reflecting the best scientific evidence available for a particular diagnostic or therapeutic concept, including the grade of recommendation. Besides the scientific evidence, all group members rated the statements to identify possible gaps between literature and current clinical practice. CONCLUSION: In patients with minimal symptoms, OLT progression to ankle osteoarthritis is unlikely. Risk factors for progression are the depth of the lesion on MRI, subchondral cyst formation, and the extent of bone marrow edema. Conservative management is the adaptation of activities to the performance of the ankle joint. A follow-up imaging after 12 months helps not to miss any progression. It is impossible to estimate the probability of success of conservative management from initial symptoms and imaging. Cast immobilization is an option in OLTs in children, with a success rate of approximately 50%, although complete healing, estimated from imaging, is rare. In adults, improvement by conservative management ranges between 45% and 59%. Rest and restrictions for sports activities seem to be more successful than immobilization. Intra-articular injections of hyaluronic acid and platelet-rich plasma can improve pain and functional scores for more than 6 months. If 3 months of conservative management does not improve symptoms, surgery can be recommended.