Amine adducts of triallylborane as highly reactive allylborating agents for Cu(I)-catalyzed allylation of chiral sulfinylimines.

The implementation of selective catalytic processes with highly active reagents is an attractive strategy that meets the modern principles of sustainable development of chemistry. In the current study, we for the first time describe the method and general principles of Cu(I)-catalyzed allylation of imines with amine adducts of allylic triorganoboranes. Triallylborane is an extremely reactive compound and cannot be used for the catalytic allylation of imines, whereas its amine adducts are ideal substrates for catalysis. The structure of the amine fragment successfully balances the safety, selectivity and stability of the allylboron reagent, allowing it to demonstrate high activity in catalytic allylation reactions, exceeding many times any known allylboranes. The obtained results are supported by quantitative kinetics data and DFT calculations. The catalytic efficacy of the system was demonstrated on model sulfinylimines (23 examples). High diastereoselectivity up to >99% was achieved, including for the gram-scale synthesis of 2-hydroxyphenyl-derivatives. Taking into account the high reactivity and unsurpassed atom-economy of amine adducts of triallylborane (AAT), they can be considered as prospective allylation reagents with Cu(I) and other appropriate metallocatalysts.

Exposure of volunteers to microgravity by dry immersion bed over 21 days results in gene expression changes and adaptation of T cells.

The next steps of deep space exploration are manned missions to Moon and Mars. For safe space missions for crew members, it is important to understand the impact of space flight on the immune system. We studied the effects of 21 days dry immersion (DI) exposure on the transcriptomes of T cells isolated from blood samples of eight healthy volunteers. Samples were collected 7 days before DI, at day 7, 14, and 21 during DI, and 7 days after DI. RNA sequencing of CD3+ T cells revealed transcriptional alterations across all time points, with most changes occurring 14 days after DI exposure. At day 21, T cells showed evidence of adaptation with a transcriptional profile resembling that of 7 days before DI. At 7 days after DI, T cells again changed their transcriptional profile. These data suggest that T cells adapt by rewiring their transcriptomes in response to simulated weightlessness and that remodeling cues persist when reexposed to normal gravity.

High density lithium niobate photonic integrated circuits.

Photonic integrated circuits have the potential to pervade into multiple applications traditionally limited to bulk optics. Of particular interest for new applications are ferroelectrics such as Lithium Niobate, which exhibit a large Pockels effect, but are difficult to process via dry etching. Here we demonstrate that diamond-like carbon (DLC) is a superior material for the manufacturing of photonic integrated circuits based on ferroelectrics, specifically LiNbO3. Using DLC as a hard mask, we demonstrate the fabrication of deeply etched, tightly confining, low loss waveguides with losses as low as 4 dB/m. In contrast to widely employed ridge waveguides, this approach benefits from a more than one order of magnitude higher area integration density while maintaining efficient electro-optical modulation, low loss, and offering a route for efficient optical fiber interfaces. As a proof of concept, we demonstrate a III-V/LiNbO3 based laser with sub-kHz intrinsic linewidth and tuning rate of 0.7 PHz/s with excellent linearity and CMOS-compatible driving voltage. We also demonstrated a MZM modulator with a 1.73 cm length and a halfwave voltage of 1.94 V.

Bilateral metalloheterocyclic systems based on palladacycle and piperidine-2,4-dione pharmacophores.

The design of molecules with effective anticancer properties constructed from both dually active metal complex and organic fragments is a novel trend in medicinal chemistry. This concept suggests the impact of a drug on several biological targets or the synergistic action of both fragments as a single unit. We propose that the combination of a Pd-metallocomplex fragment and an organic unit can be an interesting model for anticancer drug discovery. The first phase in the development of such suggested molecules is the synthesis of bilateral metallosystems containing bioactive 6-substituted piperidin-2-one and a palladated N-phenylpyrazolic fragment. Both fragments were incorporated into one molecule through the fused pyrazole-piperidine-2-one unit followed by pyrazol-directed cyclopalladation of the phenyl-group with Pd(OAc)2. An effect of acceleration of the rate of the palladation by NH-lactam was observed. The synthesized hybrid palladacycles have been characterized and tested for their cytotoxic activity on three cancerous cell lines as PPh3 complexes, revealing structures with potential for further development and structural optimization.

Energy Efficient Single Pulse Switching of [Co/Gd/Pt]N Nanodisks Using Surface Lattice Resonances.

The impact of plasmonic surface lattice resonances on the magneto-optical properties and energy absorption efficiency has been studied in arrays of [Co/Gd/Pt]N multilayer nanodisks. Varying the light wavelength, the disk diameter, and the period of the array, it is demonstrated that surface lattice resonances allow all-optical single pulse switching of [Co/Gd/Pt]N nanodisk arrays with an energy 400% smaller than the energy needed to switch a continuous [Co/Gd/Pt]N film. Moreover, the magneto-optical Faraday effect is enhanced at the resonance condition by up to 5,000%. The influence of the disk diameter and array period on the amplitude, width and position of the surface lattice resonances is in qualitative agreement with theoretical calculations and opens the way to designing magnetic metasurfaces for all-optical magnetization switching applications.

A photonic integrated continuous-travelling-wave parametric amplifier.

The ability to amplify optical signals is of pivotal importance across science and technology typically using rare-earth-doped fibres or gain media based on III-V semiconductors. A different physical process to amplify optical signals is to use the Kerr nonlinearity of optical fibres through parametric interactions1,2. Pioneering work demonstrated continuous-wave net-gain travelling-wave parametric amplification in fibres3, enabling, for example, phase-sensitive (that is, noiseless) amplification4, link span increase5, signal regeneration and nonlinear phase noise mitigation6. Despite great progress7-15, all photonic integrated circuit-based demonstrations of net parametric gain have necessitated pulsed lasers, limiting their practical use. Until now, only bulk micromachined periodically poled lithium niobate (PPLN) waveguide chips have achieved continuous-wave gain16,17, yet their integration with silicon-wafer-based photonic circuits has not been shown. Here we demonstrate a photonic-integrated-circuit-based travelling-wave optical parametric amplifier with net signal gain in the continuous-wave regime. Using ultralow-loss, dispersion-engineered, metre-long, Si3N4 photonic integrated circuits18 on a silicon chip of dimensions 5 × 5 mm2, we achieve a continuous parametric gain of 12 dB that exceeds both the on-chip optical propagation loss and fibre-chip-fibre coupling losses in the telecommunication C band. Our work demonstrates the potential of photonic-integrated-circuit-based parametric amplifiers that have lithographically controlled gain spectrum, compact footprint, resilience to optical feedback and quantum-limited performance, and can operate in the wavelength ranges from visible to mid-infrared and outside conventional rare-earth amplification bands.

Tuning of Magnetic Damping in Y3Fe5O12/Metal Bilayers for Spin-Wave Conduit Termination.

In this work, we investigate the structural and dynamic magnetic properties of yttrium iron garnet (YIG) films grown onto gadolinium gallium garnet (GGG) substrates with thin platinum, iridium, and gold spacer layers. Separation of the YIG film from the GGG substrate by a metal film strongly affects the crystalline structure of YIG and its magnetic damping. Despite the presence of structural defects, however, the YIG films exhibit a clear ferromagnetic resonance response. The ability to tune the magnetic damping without substantial changes to magnetization offers attractive prospects for the design of complex spin-wave conduits. We show that the insertion of a 1-nm-thick metal layer between YIG and GGG already increases the effective damping parameter enough to efficiently absorb spin waves. This bilayer structure can therefore be utilized for magnonic waveguide termination. Investigating the dispersionless propagation of spin-wave packets, we demonstrate that a damping unit consisting of the YIG/metal bilayers can dissipate incident spin-wave signals with reflection coefficient R < 0.1 at a distance comparable to the spatial width of the wave packet.

Nucleophilic Substitution Reactions in the [B3H8]- Anion in the Presence of Lewis Acids.

As a result of our study on the interaction between the octahydrotriborate anion with nucleophiles (Nu = THF, Ph3P, Ph2P-(CH2)2-PPh2 (dppe), Ph3As, Et3N, PhNH2, C5H5N, CH3CN, Ph2CHCN)) in the presence of a wide range of Lewis acids (Ti(IV), Hf(IV), Zr(IV), Al, Cu(I), Zn, Mn(II), Co(II) halides and iodine), a number of substituted derivatives of the octahydrotriborate anion [B3H7Nu] are obtained. It is found that the use of TiCl4, AlCl3, ZrCl4, HfCl4, CuCl and iodine leads to the highest product yields. In this case, it is most likely that the reaction proceeds through the formation of an intermediate [B3H7-HMXnx], which was detected by NMR spectroscopy. The structures of [Ph3P·B3H7] and [PhNH2·B3H7] were determined by X-ray diffraction.

Half-Sandwich Cyclometalated RhIII Complexes Bearing Thiolate Ligands: Biomolecular Interactions and In Vitro and In Vivo Evaluations.

A class of cyclometalated RhIII complexes [Cp*Rh(ppy)(SR)] bearing thiolate ligands, Cp* = pentamethylcyclopentadienyl, ppy = 2-phenylpyridinate, and R = pyridyl (Spy, 2), pyrimidyl (SpyN, 3), benzimidazolyl (Sbi, 4), and benzothiazolyl (Sbt, 5), were produced and identified by means of spectroscopic methods. The in vitro cytotoxicity of the RhIII compounds in three different human mortal cancerous cell lines (ovarian, SKOV3; breast, MCF-7; lung, A549) and a normal lung (MRC-5) cell line were evaluated, indicating the selectivity of these cyclometalated RhIII complexes to cancer cells. Complex 5, selected for in vivo experiment, has shown an effective inhibition of tumor growth in SKOV3 xenograft mouse model relative to control (p-values < 0.05 and < 0.01). Importantly, the outcomes of H&E (hematoxylin and eosin) staining and hematological analysis revealed negligible toxicity of 5 compared to cisplatin on a functioning of the main organs of mouse. Molecular docking, UV-vis, and emission spectroscopies (fluorescence, 3D fluorescence, synchronous) techniques were carried out on 1-5 to peruse the mechanism of the anticancer activities of these complexes. The obtained data help to manifest the binding affinity between the rhodium compounds and calf thymus DNA (CT-DNA) through the interaction by DNA minor groove and moderate binding affinity with bovine serum albumin (BSA), particularly with the cavity in the subdomain IIA. It can be concluded that the Rh-thiolate complexes are highly promising leads for the development of novel effective DNA-targeted anticancer drugs.

Expanding Characterized Diversity and the Pool of Complete Genome Sequences of Methylococcus Species, the Bacteria of High Environmental and Biotechnological Relevance.

The bacterial genus Methylococcus, which comprises aerobic thermotolerant methanotrophic cocci, was described half-a-century ago. Over the years, a member of this genus, Methylococcus capsulatus Bath, has become a major model organism to study genomic and metabolic basis of obligate methanotrophy. High biotechnological potential of fast-growing Methylococcus species, mainly as a promising source of feed protein, has also been recognized. Despite this big research attention, the currently cultured Methylococcus diversity is represented by members of the two species, M. capsulatus and M. geothermalis, while finished genome sequences are available only for two strains of these methanotrophs. This study extends the pool of phenotypically characterized Methylococcus strains with good-quality genome sequences by contributing four novel isolates of these bacteria from activated sludge, landfill cover soil, and freshwater sediments. The determined genome sizes of novel isolates varied between 3.2 and 4.0Mb. As revealed by the phylogenomic analysis, strains IO1, BH, and KN2 affiliate with M. capsulatus, while strain Mc7 may potentially represent a novel species. Highest temperature optima (45-50°C) and highest growth rates in bioreactor cultures (up to 0.3h-1) were recorded for strains obtained from activated sludge. The comparative analysis of all complete genomes of Methylococcus species revealed 4,485 gene clusters. Of these, pan-genome core comprised 2,331 genes (on average 51.9% of each genome), with the accessory genome containing 846 and 1,308 genes in the shell and the cloud, respectively. Independently of the isolation source, all strains of M. capsulatus displayed surprisingly high genome synteny and a striking similarity in gene content. Strain Mc7 from a landfill cover soil differed from other isolates by the high content of mobile genetic elements in the genome and a number of genome-encoded features missing in M. capsulatus, such as sucrose biosynthesis and the ability to scavenge phosphorus and sulfur from the environment.

Synthesis of Hafnium(IV) Polyaminoacetates.

The interaction of hafnium(IV) salts (oxide-dichloride, chloride, and bromide) with nitrilotriacetic acid (NTA), diethylenetriamminepentaacetic acid (DTPA), 1,2-diaminocyclohexanetetraacetic acid (CDTA), 1,3-dipropylmino-2-hydroxy N,N,N',N'-tetraacetic acid (dpta), and N-(2-hydroxyethyl)ethylenediamine triacetic acid (HEDTA) has been studied. The corresponding complexes Na2[Hf(NTA)2]·3H2O (1), Na[HfDTPA]·3H2O (2), [HfCDTA(H2O)2] (3), and Na[Hf2(dpta)2]·7.5H2O·0.5C2H5OH (4) have been isolated and characterized and their structures have been determined by single crystal X-ray diffraction. Biological studies of [HfCDTA(H2O)2] have shown that in 5% glucose solution this complex has low toxicity and good contrasting ability.

Construction of piperidine-2,4-dione-type azaheterocycles and their application in modern drug development and natural product synthesis.

The current review summarizes the latest achievements in the synthesis of piperidine-2,4-dione-type azaheterocycles. Two main groups traditional (carbonyl compound transformations) and novel (anionic enolate rearrangements) of complementary methods for the simple and effective preparation of structurally diverse compounds in racemic and enantiopure forms have been reported. Due to the specific structure and appropriate reactivity profiles of dione-type molecules, they are a convenient modern platform for the construction of functionalized piperidine-type systems possessing high synthetic and medicinal potential. This potential is successfully realized by the creation of highly active pharmaceutically relevant compounds and the synthesis of natural products.

An intronic deletion in megakaryoblastic leukemia 1 is associated with hyperproliferation of B cells in triplets with Hodgkin lymphoma.

Megakaryoblastic leukemia 1 (MKL1) is a coactivator of serum response factor and together they regulate transcription of actin cytoskeleton genes. MKL1 is associated with hematologic malignancies and immunodeficiency, but its role in B cells is unexplored. Here we examined B cells from monozygotic triplets with an intronic deletion in MKL1, two of whom had been previously treated for Hodgkin lymphoma (HL). To investigate MKL1 and B-cell responses in the pathogenesis of HL, we generated Epstein-Barr virus-transformed lymphoblastoid cell lines from the triplets and two controls. While cells from the patients with treated HL had a phenotype close to that of the healthy controls, cells from the undiagnosed triplet had increased MKL1 mRNA, increased MKL1 protein, and elevated expression of MKL1-dependent genes. This profile was associated with elevated actin content, increased cell spreading, decreased expression of CD11a integrin molecules, and delayed aggregation. Moreover, cells from the undiagnosed triplet proliferated faster, displayed a higher proportion of cells with hyperploidy, and formed large tumors in vivo This phenotype was reversible by inhibiting MKL1 activity. Interestingly, cells from the triplet treated for HL in 1985 contained two subpopulations: one with high expression of CD11a that behaved like control cells and the other with low expression of CD11a that formed large tumors in vivo similar to cells from the undiagnosed triplet. This implies that pre-malignant cells had re-emerged a long time after treatment. Together, these data suggest that dysregulated MKL1 activity participates in B-cell transformation and the pathogenesis of HL.

Dimethylamine adducts of allylic triorganoboranes as effective reagents for Petasis-type homoallylation of primary amines with formaldehyde.

Dimethylamine adducts of triallyl-, triprenyl- and trans-cinnamyl(dipropyl)borane are effective reagents for mild homoallylation of primary amines with aqueous formaldehyde in MeOH without an inert atmosphere. A new concept is proposed for the explanation of the high stability of allylborane-amine adducts in aqueous MeOH.

Adducts of Triallylborane with Ammonia and Aliphatic Amines as Stoichiometric Allylating Agents for Aminoallylation Reaction of Carbonyl Compounds.

Triallylborane-amines adducts are effective stoichiometric allylating agents in the aminoallylation reaction of carbonyl compounds in methanol. Moreover, copper-catalyzed diastereoselective allylation of Ellman's imine was achieved with triallylborane-methylamine adduct.

Alternative Splicing of FOXP3 Controls Regulatory T Cell Effector Functions and Is Associated With Human Atherosclerotic Plaque Stability.

RATIONALE: Regulatory T (Treg) cells suppress immune responses and have been shown to attenuate atherosclerosis. The Treg cell lineage-specification factor FOXP3 (forkhead box P3) is essential for Treg cells' ability to uphold immunologic tolerance. In humans, FOXP3 exists in several different isoforms, however, their specific role is poorly understood. OBJECTIVE: To define the regulation and functions of the 2 major FOXP3 isoforms, FOXP3fl and FOXP3Δ2, as well as to establish whether their expression is associated with the ischemic atherosclerotic disease. METHODS AND RESULTS: Human primary T cells were transduced with lentiviruses encoding distinct FOXP3 isoforms. The phenotype and function of these cells were analyzed by flow cytometry, in vitro suppression assays and RNA-sequencing. We also assessed the effect of activation on Treg cells isolated from healthy volunteers. Treg cell activation resulted in increased FOXP3 expression that predominantly was made up of FOXP3Δ2. FOXP3Δ2 induced specific transcription of GARP (glycoprotein A repetitions predominant), which functions by tethering the immunosuppressive cytokine TGF (transforming growth factor)-ß to the cell membrane of activated Treg cells. Real-time polymerase chain reaction was used to determine the impact of alternative splicing of FOXP3 in relation with atherosclerotic plaque stability in a cohort of >150 patients that underwent carotid endarterectomy. Plaque instability was associated with a lower FOXP3Δ2 transcript usage, when comparing plaques from patients without symptoms and patients with the occurrence of recent (<1 month) vascular symptoms including minor stroke, transient ischemic attack, or amaurosis fugax. No difference was detected in total levels of FOXP3 mRNA between these 2 groups. CONCLUSIONS: These results suggest that activated Treg cells suppress the atherosclerotic disease process and that FOXP3Δ2 controls a transcriptional program that acts protectively in human atherosclerotic plaques.

The Small Rho GTPases Rac1 and Rac2 Are Important for T-Cell Independent Antigen Responses and for Suppressing Switching to IgG2b in Mice.

The Rho GTPases Cdc42, Rac1, and Rac2 coordinate receptor signaling to cell adhesion, migration, and proliferation. Deletion of Rac1 and Rac2 early during B cell development leads to failure in B cell entry into the splenic white pulp. Here, we sought to understand the role of Rac1 and Rac2 in B cell functionality and during the humoral antibody response. To circumvent the migratory deficiency of B cells lacking both Rac1 and Rac2, we took the approach to inducibly delete Rac1 in Rac2-/- B cells in the spleen (Rac1BRac2-/- B cells). Rac1BRac2-/- mice had normal differentiation of splenic B cell populations, except for a reduction in marginal zone B cells. Rac1BRac2-/- B cells showed normal spreading response on antibody-coated layers, while both Rac2-/- and Rac1BRac2-/- B cells had reduced homotypic adhesion and decreased proliferative response when compared to wild-type B cells. Upon challenge with the T-cell-independent antigen TNP-conjugated lipopolysaccharide, Rac1BRac2-/- mice showed reduced antibody response. In contrast, in response to the T-cell-dependent antigen sheep red blood cells, Rac1BRac2-/- mice had increased serum titers of IgG1 and IgG2b. During in vitro Ig class switching, Rac1BRac2-/- B cells had elevated germline γ2b transcripts leading to increased Ig class switching to IgG2b. Our data suggest that Rac1 and Rac2 serve an important role in regulation of the B cell humoral immune response and in suppressing Ig class switching to IgG2b.

Nuclear Wiskott-Aldrich syndrome protein co-regulates T cell factor 1-mediated transcription in T cells.

BACKGROUND: The Wiskott-Aldrich syndrome protein (WASp) family of actin-nucleating factors are present in the cytoplasm and in the nucleus. The role of nuclear WASp for T cell development remains incompletely defined. METHODS: We performed WASp chromatin immunoprecipitation and deep sequencing (ChIP-seq) in thymocytes and spleen CD4+ T cells. RESULTS: WASp was enriched at genic and intergenic regions and associated with the transcription start sites of protein-coding genes. Thymocytes and spleen CD4+ T cells showed 15 common WASp-interacting genes, including the gene encoding T cell factor (TCF)12. WASp KO thymocytes had reduced nuclear TCF12 whereas thymocytes expressing constitutively active WASpL272P and WASpI296T had increased nuclear TCF12, suggesting that regulated WASp activity controlled nuclear TCF12. We identify a putative DNA element enriched in WASp ChIP-seq samples identical to a TCF1-binding site and we show that WASp directly interacted with TCF1 in the nucleus. CONCLUSIONS: These data place nuclear WASp in proximity with TCF1 and TCF12, essential factors for T cell development.

Stereoselective synthesis of novel adamantane derivatives with high potency against rimantadine-resistant influenza A virus strains.

A series of (R)- and (S)-isomers of new adamantane-substituted heterocycles (1,3-oxazinan-2-one, piperidine-2,4-dione, piperidine-2-one and piperidine) with potent activity against rimantadine-resistant strains of influenza A virus were synthesized through the transformation of adamantyl-substituted N-Boc-homoallylamines 8 into piperidine-2,4-diones 11 through the cyclic bromourethanes 9 and key intermediate enol esters 10. Biological assays of the prepared compounds were performed on the rimantadine-resistant S31N mutated strains of influenza A - A/California/7/2009(H1N1)pdm09 and modern pandemic strain A/IIV-Orenburg/29-L/2016(H1N1)pdm09. The most potent compounds were both enantiomers of the enol ester 10 displaying IC50 = 7.7 µM with the 2016 Orenburg strain.

Biomarkers can predict potential clinical responders to DIMS0150 a toll-like receptor 9 agonist in ulcerative colitis patients.

BACKGROUND: Glucocorticoids (GCS) remain one of the mainstay treatments in the management of ulcerative colitis (UC) but up to a third of patients will ultimately fail to respond and progress to a more severe and difficult to manage disease state. Previous clinical studies suggest that the Toll-Like Receptor 9 (TLR9) agonist DIMS0150 not only induces production of key anti-inflammatory cytokines as IL-10 but interestingly also enhances steroid sensitivity in steroid refractory UC patients. We investigated, in the context of a clinical study, whether a pre-selection of steroid response genes could identify steroid refractory UC subjects most likely to respond to DIMS0150 treatment. METHODS: In a non-interventional pilot study, blood from steroid refractory UC patients and healthy volunteers was taken and thirty-four previously described steroid response genes were analysed by real time PCR analysis. To establish clinical utility of the identified biomarkers, a placebo controlled, randomized, double blinded study in active steroid dependent and steroid resistant UC patients on concomitant steroid therapies was used (EudraCT number: 2006-001846-15). RESULTS: We identified three potential biomarkers CD163, TSP-1 and IL-1RII whose response to steroids was significantly enhanced when DIMS0150 was applied. Thirty-four subjects were randomized to receive a single rectal administration of placebo or 30 mg of DIMS0150. Blood derived PBMCs were obtained prior to dosing and assayed for evidence of a steroid enhancing effect following steroid incubation in the presence of DIMS0150. Comparison to established steroid sensitivity marker IL-6 confirmed that clinical responders are steroid refractory UC patients. Upon study completion and un-blinding, the biomarker assay correctly predicted a clinical response in over 90% of the patients. CONCLUSION: Using specific steroid response biomarkers, GCS refractory UC patients most likely to benefit from DIMS0150 treatment could be identified and illustrates the usefulness of a personalized treatment approach.