Reptiles show a remarkable diversity of sex determination mechanisms and sex chromosome systems, derived from different autosomal pairs. The origin of the ZW sex chromosomes of Lacerta agilis, a widespread Eurasian lizard species, is a matter of discussion: is it a small macrochromosome from the 11-18 group, common to all lacertids, or this species has unique ZW pair derived from the large chromosome 5. Using independent molecular cytogenetic methods, we investigated the karyotype of L. agilis exigua...
Mon Nov 18, 2019 02:00
The evolution of bacterial regulatory networks has largely been explained at macroevolutionary scales through lateral gene transfer and gene duplication. Transcription factors (TF) have been found to be less conserved across species than their target genes (TG). This would be expected if TFs accumulate mutations faster than TGs. This hypothesis is supported by several lab evolution studies which found TFs, especially global regulators, to be frequently mutated. Despite these studies, the contribution...
Mon Nov 18, 2019 02:00
A major research goal in evolutionary genetics is to uncover loci experiencing positive selection. One approach involves finding 'selective sweeps' patterns, which can either be 'hard sweeps' formed by de novo mutation, or 'soft sweeps' arising from recurrent mutation or existing standing variation. Existing theory generally assumes outcrossing populations, and it is unclear how dominance affects soft sweeps. We consider how arbitrary dominance and inbreeding via self-fertilisation affect hard and...
Mon Nov 18, 2019 02:00
Because the evolution of modern humans from early mammals has been a continuous process, human genetic diversity at the molecular level should reflect mammalian genetic diversity. To test this prediction, we contrasted the proportion of segregating sites, q, in human data from the 1000 Genome Project with phylogenetic trees of genes in 96 mammalian genomes ranging from human to platypus. The evolvability of a gene in the human population was found to be positively correlated with the long-term molecular...
Mon Nov 18, 2019 02:00
Genome studies of facultative sexual species are providing insight into the evolutionary consequences of mixed reproductive modes. However, it is unclear if the evolutionary history of facultative sexuals' genomes can be captured by standard population genetic models; in particular, whether they can be approximated by Wright-Fisher dynamics while assuming a rescaled effective population size Ne. Here, I determine when the gene genealogies of diploid facultative sexuals, which can either reproduce...
Mon Nov 18, 2019 02:00
Reptiles show a remarkable diversity of sex determination mechanisms and sex chromosome systems, derived from different autosomal pairs. The origin of the ZW sex chromosomes of Lacerta agilis, a widespread Eurasian lizard species, is a matter of discussion: is it a small macrochromosome from the 11-18 group, common to all lacertids, or this species has unique ZW pair derived from the large chromosome 5. Using independent molecular cytogenetic methods, we investigated the karyotype of L. agilis exigua...
Mon Nov 18, 2019 02:00
Recombination, variance in genetic relatedness, and selection against introgressed DNA [NEW RESULTS]
The genomic proportion that two relatives share identically by descent - their genetic relatedness - can vary depending on the patterns of recombination and segregation in their pedigree. Here, we calculate the precise connection between genome-wide genetic shuffling and variance in genetic relatedness. For the relationships of grandparent-grandoffspring and siblings, the variance in genetic relatedness is a simple decreasing function of[r] , the average proportion of locus pairs that recombine in...
Mon Nov 18, 2019 02:00
The phylogenetic analysis of Y chromosomal haplogroup O2a-M95 was crucial to determine the nested structure of South Asian branches within the larger tree, predominantly present in East and Southeast Asia. However, it had previously been unclear how many founders brought the haplogroup O2a-M95 to South Asia. On the basis of the updated Y chromosomal tree for haplogroup O2a-M95, we analysed 1,437 male samples from South Asia for various downstream markers, carefully selected from the extant phylogenetic...
Mon Nov 18, 2019 02:00
In a number of animal species, divergent natural selection has repeatedly and independently driven the evolution of reproductive isolation between populations adapted to contrasting, but not to similar environments. This process is known as parallel ecological speciation, and examples in plants are enigmatically rare. Here, we perform a comprehensive test of the ecological speciation hypothesis in an Australian wildflower where parapatric populations found in coastal sand dunes (Dune ecotype) and...
Mon Nov 18, 2019 02:00
Chromosomal inversions contribute widely to adaptation and speciation, yet they present a unique evolutionary puzzle as both their allelic content and frequency evolve in a feedback loop. In this simulation study, we quantified the role of the allelic content in determining the long-term fate of the inversion. Recessive deleterious mutations accumulated rapidly on both arrangements with most of them being private to a given arrangement. The emerging overdominance led to maintenance of the inversion...
Mon Nov 18, 2019 02:00
Natural selection is a major driver for the origins of adaptations and new species. Whether or not the processes driving adaptation and speciation share a molecular basis remains largely unknown. Here, we show that divergence in hormone signalling contributed to the evolution of complex adaptations and intrinsic reproductive isolation in the Australian wildflower Senecio lautus. We provide evidence that differences in the auxin pathway, a hormone required for plant growth and development, has led...
Mon Nov 18, 2019 02:00
Human-mediated transport creates secondary contacts between genetically differentiated lineages, bringing new opportunities for gene exchange. When similar introductions occur in different places, they provide informally replicated experiments for studying hybridisation. We here examined 4279 Mytilus mussels, sampled in Europe and genotyped with 77 ancestry informative markers. We identified a type of introduced mussels, called 'dock mussels', associated with port habitats and displaying a particular...
Mon Nov 18, 2019 02:00
New techniques for the species-level sorting of millions of specimens are needed in order to accelerate species discovery, determine how many species live on earth, and develop efficient biomonitoring techniques. These sorting methods should be reliable, scalable and cost-effective, as well as being largely insensitive to low-quality genomic DNA, given that this is usually all that can be obtained from museum specimens. Mini-barcodes seem to satisfy these criteria, but it is unclear how well they...
Mon Nov 18, 2019 02:00
Occasionally during protein synthesis, the ribosome bypasses the stop codon and continues translation to the next stop codon in frame. This error is called translational readthrough (TR). Earlier research suggest that TR is a relatively common error, in several taxa, yet the evolutionary relevance of this translational error is still unclear. By analysing ribosome profiling data, we have conducted species comparisons between yeasts to infer conservation of TR between orthologs. Moreover, we infer...
Mon Nov 18, 2019 02:00
Abstract Purpose Ineffective use of continuous positive airway pressure (CPAP) therapy can result in inconvenience and additional costs in patients with obstructive sleep apnea (OSA). This study investigated the predictive value of body mass index (BMI) to assess the efficacy of CPAP in patients with OSA. Methods Data were extracted from a retrospective study...
Mon Nov 18, 2019 02:00
Suspension microlaryngoscopy (SML) is generally a safe, same-day procedure. Complications have been linked to prolonged operative time and substantial force applied to the tongue. This report of two cases describes marked tongue edema following SML, a complication not yet reported in the literature.
Mon Nov 18, 2019 02:00
There have been several reports of spontaneous closure and reopening of a macular hole, however, in most of those cases, it was observed in eyes post vitrectomy. Here, we report a case of multiple episodes of ...
Sun Nov 17, 2019 02:00
Regulatory T cells (Tregs) play a central role in the induction and maintenance of immune homeostasis and self-tolerance. Tregs constantly express the high-affinity receptor to IL-2. IL-2 is a pleiotropic cytokine and a key survival factor for Tregs. It maintains Tregs’ suppressive function by promoting Foxp3 expression and subsequent production of immunoregulatory cytokines. Administration of low-dose IL-2 is shown to be a promising approach to prevent allograft rejection and to treat autoimmune...
Mon Nov 18, 2019 23:00
Key PointsPseudomonas bacterial lung infection leads to pulmonary ACE2 dynamic variation. The ACE2 dynamic alteration is critical in regulating neutrophilic lung inflammation. ACE2 modulates IL-17–mediated neutrophil influx by impacting STAT3 activity.
Mon Nov 18, 2019 23:00
Inflammasomes are cytoplasmic multiprotein complexes that coordinate inflammatory responses, including those that take place during pregnancy. Inflammasomes and their downstream mediators caspase-1 and IL-1β are expressed by gestational tissues (e.g., the placenta and chorioamniotic membranes) during normal pregnancy. Yet, only the activation of the NLRP3 inflammasome in the chorioamniotic membranes has been partially implicated in the sterile inflammatory process of term parturition. In vivo and...
Mon Nov 18, 2019 23:00
Key PointsFOH promotes CD1d expression in human DC via activation of PPAR, RARα, and p38 MAPK. FOH modulates cytokine release through nuclear receptors, MAPK, and NF-B pathways. FOH diminishes human DC capacity to activate iNKT, Th1, and FOXP3+ regulatory T cells.
Mon Nov 18, 2019 23:00
Key PointsTCR signal strength regulates acetyl-CoA metabolism. Weak TCR signals promote phosphorylation of citrate synthase via Akt. TCR signal strength differentially regulates acetyl-lysine containing proteins.
Mon Nov 18, 2019 23:00
Key PointsUhrf1-mediated DNA methylation represses Tnf-α expression in macrophages. Uhrf1 deficiency augments Tnf-α expression, resulting in aggravated colitis. Tnf-α triggers macrophage activation through destabilizing Uhrf1 protein.
Mon Nov 18, 2019 23:00
Key PointsLARI inhibits allergic reactivity while displaying an excellent safety profile. LARI blunts allergic responses via multiple mechanisms at multiple steps.
Mon Nov 18, 2019 23:00
Key PointsAnti–IL-15 depletes NK cells and disrupts TEM homeostasis in SIV-infected RM. IL-15 inhibition does not alter SIV replication dynamics or CD4+ T cell depletion. IL-15 inhibition does accelerate reactivation of an oncogenic -herpesvirus.
Mon Nov 18, 2019 23:00
Key PointsAutoreactive T cells drive the lethal disease in Malt1PD mice. Malt1PD mice display B cell hyperactivation to environmental Ags. IPEX-like disease occurs in Malt1PD mice despite in vitro Treg suppressive activity.
Mon Nov 18, 2019 23:00
Key PointsEarly monocyte infiltration causes long-term microgliosis in sepsis. Brain microglia self-proliferate during severe sepsis. Microglia proliferation is associated with local M-CSF.
Mon Nov 18, 2019 23:00
Key PointsCREMα induces DUSP4 phosphatase expression in CD4+ T cells. DUSP4 promotes IL-17A and reduces IL-2 production by effector T cells. The CREMα/DUSP4 axis is involved in the pathophysiology of SLE.
Mon Nov 18, 2019 23:00
Key PointsUbc9 interacts with and SUMOylates the immune adaptor SLP-76 in T cells. Synergy of SLP-76–Ubc9 on IL-2 transcription is SLP-76 SUMOylation dependent. SLP-76 SUMOylation is required for Ubc9-NFAT complex assembly for IL-2 transcription.
Mon Nov 18, 2019 23:00
Key PointsCD11c+ ABCs exhibit functional characteristics of MBCs. ABCs express polyreactive B cell receptors binding diverse self-antigens. Adoptively transferred ABCs contribute to rapid recall responses to viral Ags.
Mon Nov 18, 2019 23:00
Key PointsInhibitory receptors are upregulated on peripheral Tregs of DC-deficient mice. Tregs from DC-deficient mice are functionally impaired. Tregs require DCs for inhibition of T cell transfer-induced colitis.
Mon Nov 18, 2019 23:00
Key PointsUBASH3A interacts with the TCR–CD3 complex and regulates its turnover. UBASH3A facilitates the downmodulation of cell-surface TCR–CD3 upon TCR engagement. UBASH3A binds to CBL-B, another T1D-associated protein that inhibits T cell function.
Mon Nov 18, 2019 23:00
Key PointsMAIT cells comprise half the CD8 T cell IFN- response to BCG in blood. Frequencies of MAIT cells were not sustainably modulated by BCG vaccination. Innate cytokines mediate BCG-induced MAIT cell responses in whole blood.
Mon Nov 18, 2019 23:00
Key PointsTNF-Tg mice develop NSIP-like lung disease with increased cDC2 and macrophages. Anti-TNF therapy modulates prefibrotic ILD in TNF-Tg mice.
Mon Nov 18, 2019 23:00
Key PointsNK cells are required for immune control of secondary T. gondii infection. NK cells do not develop intrinsic memory-like features during T. gondii infection. Secondary NK cell responses depend upon IL-12 and IL-23.
Mon Nov 18, 2019 23:00
Key PointsRegulatory T cells can undergo extensive intravascular crawling in skin vessels. Mechanisms of regulatory T cell transmigration can be modulated dynamically.
Mon Nov 18, 2019 23:00
Key PointsDR3 is highly expressed on human MAIT cells. DR3 ligand TL1A licenses innate TNF-α production and boosts polyfunctionality. TL1A equally augments TCR-dependent MAIT cell effector functions.
Mon Nov 18, 2019 23:00
Key PointsRELMα (hResistin) activates pulmonary macrophages in PAH patients and hypoxic mice. RELMα (hResistin) induces HMGB1 acetylation by suppressing Sirt1 in macrophages. The RELMα–HMGB1 axis causes macrophage-mediated PASMC proliferation.
Mon Nov 18, 2019 23:00
Key PointsGSK3β interacts with Src tyrosine kinase. Src positively regulates antiviral immune response. Src undergoes K63-linked ubiquitination by TRAF2.
Mon Nov 18, 2019 23:00
Key PointsTLR2 directly regulates the anti-CD3–activated CD8+ T cells independently on APCs. Bioenergy metabolism is important for TLR2-mediated enhancement of CD8+ T cells. TLR2 enhances the antiviral CD8+ T cell response and the efficacy of HBV vaccine.
Mon Nov 18, 2019 23:00
Key PointsExercise enhances resolution of acute inflammation and RvD1 biosynthesis. Epinephrine stimulates macrophage production of RvD1 through α1-AR. α1-AR blockade in vivo abrogates exercise-enhanced resolution.
Mon Nov 18, 2019 23:00
Key PointsMHCII molecule upregulation is not required for the development of skin moDCs. Skin CD206+ moDCs do not migrate to LNs in the absence of MHCII ubiquitination. GM-CSF restores the migration of skin moDCs by upregulating CCR7 and IRF4.
Mon Nov 18, 2019 23:00
Key PointsRecognition of monomeric Lex by IG5F6 using a panel of Lex analogues was studied. Anti-Lex mAbs bind in different ways; the hydrophobic patch of β-d-Gal is essential.
Mon Nov 18, 2019 23:00
Key PointsFnip1 is required for pre–B cell development/survival independent of p53 and Bcl-xL. Fnip1 is required for optimal inhibition of mTORC1 in response to amino acid restriction. Fnip1 regulates TFE3 nuclear translocation and lysosome biogenesis in pre–B cells.
Mon Nov 18, 2019 23:00
Key PointsA mucosally associated lymphoid tissue is identified in teleost pharyngeal cavity. Trout pharyngeal bacteria are mainly coated with secretory IgT. Teleost IgT plays a vital role in protecting the PC from invading pathogens.
Mon Nov 18, 2019 23:00
Key PointsTwo lamprey BCMA-like receptors interact with a single lamprey BAFF protein. BCMAL1 and BCMAL2 genes are differentially expressed during VLRB cell stimulation. BAFF-based mechanisms for B cell regulation appeared early in vertebrate evolution.
Mon Nov 18, 2019 23:00
Key PointsSTAT3 induces the expression of Wnt5a in CLL cells. Wnt5a provides CLL cells with survival advantage.
Mon Nov 18, 2019 23:00
A team of researchers has found a way to identify gene regulatory elements that could help produce 'designer' plants and lead to improvements in food crops at a critical time.
Mon Nov 18, 2019 21:03
Elysium Health, a life sciences company selling health products with a particular focus on interventions that target fundamental processes of aging, has developed the Index at-home biological age test. The company claims that the test allows users to determine their biological age at home, and provides science-backed healthy living recommendations that may be able to impact overall health. Aging is the largest risk-factor for a huge array of diseases and health issues, and, indeed, mortality....
Mon Nov 18, 2019 22:48
Optical coherence tomography (OCT) is an imaging modality that provides a micron-level look at the tissues being examined. It is used in ophthalmology to assess the eyes and for imaging the interior of arteries to help with atherectomies. Although OCT has significant potential to help clinicians evaluate the health of tissues, it has proven difficult to use deep within the body. Now, researchers at Duke University have managed to equip a rigid borescope, the kind used to look inside joints...
Mon Nov 18, 2019 21:09
Pentax Medical won FDA clearance for its ED34-i10T2 duodenoscope that features a disposable elevator end piece, making it easier to guarantee that the scope is properly sterilized between patients. This is the first scope of its kind, although we recently covered the clearance of ScopeSeal, a disposable device that snaps over a scope’s business end to keep it clean. Thanks to a disposable end piece, there are fewer parts to process when sterilizing the new ED34-i10T2 duodenoscope....
Mon Nov 18, 2019 19:27
Abstract The epidermal growth factor receptor (EGFR) is a membrane protein that regulates cell proliferation, differentiation and survival, and is a drug target for cancer therapy. Ligand-induced activation of the EGFR kinase is generally regarded to require ligand-bound-dimers, while phosphorylation and down-stream signalling is modulated by oligomers. Recent work has unveiled changes in EGFR dynamics from ligand-induced dimerization in membranes extracted from cells, however,...
Mon Nov 18, 2019 02:00
With ongoing attacks on reproductive rights and an ever-growing list of politicians, celebrities, and billionaires accused of sexual assault and harassment, we need more safe spaces, especially for individuals seeking access to sexual health care. In Toronto, calls for inclusivity and diversity in sexual health care services abound, marking a paradigmatic shift from earlier forms of sexual health care in the interwar and postwar periods, where public sexual health services existed primarily to prevent...
Mon Nov 18, 2019 22:30
The Council for Museum Anthropology is looking forward to a vibrant AAA/CASCA program this year. All members (or those interested in joining) are encouraged to attend both the CMA business meeting (Friday, November 22 at 12:15 p.m.) and reception (Friday, November 22 at 8:00 p.m.). In addition, Aaron Glass, this year’s winner of the CMA Michael Ames Award for Innovative Museum Anthropology, will be installing a complete panel version of the award-winning exhibit “The Story Box” at the Annual Meeting...
Mon Nov 18, 2019 20:30
Publication date: Available online 17 November 2019Source: European Journal of Surgical OncologyAuthor(s): M. Moustafa, E. Fasolo, D. Bassi, F.E. D'amico, E. Gringeri, Timothy M. Pawlik, U. CilloAbstractBackgroundAim of work was to investigate the prognostic impact of liver resection (LR) on locally advanced Intrahepatic Cholangiocarcinoma (IC) in comparison to alternative palliative chemotherapy (CTx).MethodA retrospective cohort study performed utilizing Surveillance, Epidemiology, and End Results...
Mon Nov 18, 2019 22:19
Abstract Background: In 2013, the American Society of Clinical Oncology (ASCO)’s Continuing Education Committee recommended establishing an interprofessional, longitudinal cohort pilot project. The main goals of the cohort were to gain feedback from oncology providers on how they use resources to address their learning needs and gain insights into the utility of different ASCO educational activities. ...
Mon Nov 18, 2019 02:00
Mon Nov 18, 2019 13:33
Abstract Purpose Achieving biochemical control (normalization of insulin-like growth factor-1 [IGF-1] and growth hormone [GH]) is a key goal in acromegaly management. However, IGF-1 and GH fluctuate over time. The true potential impact of time-varying biochemical control status on comorbidities is unclear and relies on multiple, longitudinal IGF-1 and GH measurements. This study assessed the association between time-varying biochemical...
Mon Nov 18, 2019 02:00
Mon Nov 18, 2019 08:09
Abstract The differential diagnosis for hoarseness is extensive and includes a multitude of etiologies that span a large geographic area from the brainstem to the mediastinum. Therefore, localizing a causative lesion can be extremely difficult for clinicians and radiologists alike. In this review, we will first discuss the normal anatomy of the larynx and its innervation via the vagus and recurrent laryngeal nerves. We will then proceed with a guided tour of the various infectious/inflammatory,...
Mon Nov 18, 2019 02:00
To quantify microvascular flow from high speed capillary flow image sequences, we developed STAFF (Spatial Temporal Analysis of Fieldwise Flow) software. Across the full image field and over time, STAFF evaluates flow velocities and generates a sequence of color-coded spatial maps for visualization and tabular output for quantitative analyses.
Mon Nov 18, 2019 21:00
This article presents a protocol of differential-speed centrifugation in combination with density gradient centrifugation to separate mitochondria from human ovarian cancer tissues and control ovarian tissues for quantitative proteomics analysis, resulting in a high-quality mitochondrial sample and high-throughput and high-reproducibility quantitative proteomics analysis of a human ovarian cancer mitochondrial proteome.
Mon Nov 18, 2019 20:00
Analyst, 2019, Accepted ManuscriptDOI: 10.1039/C9AN01952A, PaperDavid Joseph Sconyers, James BlakemoreHomoleptic acetonitrile complexes of first-row transition metal ions are a common product of the detrimental speciation of coordination complexes and organometallic compounds. However, the electrochemical properties of such species are...The content of this RSS Feed (c) The Royal Society of Chemistry
Mon Nov 18, 2019 02:00
Analyst, 2019, Accepted ManuscriptDOI: 10.1039/C9AN01976F, PaperKai Asai, Takashi Yamamoto, Shinichi Nagashima, Genki Ogata, Hiroshi Hibino, Yasuaki EinagaStable and continuous biosensing of electroactive species in vivo have been achieved by boron-doped diamond (BDD) electrodes owing to the outstanding electrochemical properties. However, the present problem of the biosensing...The content of this RSS Feed (c) The Royal Society of Chemistry
Mon Nov 18, 2019 02:00
Analyst, 2019, Accepted ManuscriptDOI: 10.1039/C9AN02026H, PaperMalama Chisanga, Dennis Linton, Howbeer Muhamadali, David I. Ellis, Richard Kimber, Aleksandr Mironov, Royston GoodacreThe Gram-negative bacterial pathogen Campylobacter jejuni is a major cause of foodborne gastroenteritis worldwide. Rapid detection and identification of C. jejuni informs timely prescription of appropriate therapeutics and epidemiological investigations....The content of this RSS Feed (c) The Royal Society of Chemistry
Mon Nov 18, 2019 02:00
A scoping project was funded by the Food and Agriculture Organization in 2017 on the health and safety of aquaculture workers. This project developed a template covering basic types of aquaculture production, health and safety hazards and risks, and related data on injuries and occupational ill health, regulations, social welfare conditions, and labour and industry activity in the sector. Profiles using the template were then produced for key aquaculture regions and nations across the globe where...
Mon Nov 18, 2019 19:00
Mucosal Immunology, Published online: 18 November 2019; doi:10.1038/s41385-019-0227-4IgA and the intestinal microbiota: the importance of being specific
Mon Nov 18, 2019 02:00
Mon Nov 18, 2019 02:00
Abstract Purpose and objective Randomized trials indicate that electronic or app-based assessment of patient-reported outcomes may improve outcomes in cancer patients. To analyze if an app-based follow-up would be accepted by elderly cancer patients, we conducted a single-center prospective feasibility study (NCT03196050). Materials and methods Cancer patients...
Mon Nov 18, 2019 02:00
Publication date: Available online 17 November 2019Source: Hearing ResearchAuthor(s): Katharina Vogt, Jan-Willem Wasmann, A. John Van Opstal, Ad F.M. Snik, Martijn J.H. AgterbergAbstractCongenital unilateral conductive hearing loss (UCHL) jeopardizes directional hearing and speech perception in noisy conditions. Potentially, children with congenital UCHL can benefit from fitting a hearing device, such as a bone-conduction device (BCD). However, the literature reports limited benefit from fitting...
Mon Nov 18, 2019 19:27
Publication date: Available online 18 November 2019Source: International Journal of Pediatric OtorhinolaryngologyAuthor(s): Kareem Al-Mulki, N. Wendell ToddAbstractObjectiveTo describe the association, or non-association, of public health district staffing (specifically, Early Hearing Detection and Intervention [EHDI] coordinator/navigator) and loss to follow-up in newborns who did not pass hearing screening in selected public health districts in Georgia, USA.MethodsBy Freedom of Information request,...
Mon Nov 18, 2019 19:10
Deposition of a monolayer nanoarray on the surface of a micrometer‐thick substrate is demonstrated, producing rectification characteristics at the nanoscale. The heterogeneity of the structure and the charge density are the two key factors affecting rectification. By altering the asymmetric electrolyte environment, the fabricated heterogeneous membrane can be used in energy conversion. Abstract The deposition of a monolayer nanoarray on the surface of a micrometer‐thick substrate is demonstrated,...
Mon Nov 18, 2019 19:04
1D nonplanar graphene nanoribbons generally have three possible conformers: helical, zigzag, and mixed conformations. In this research, a novel kind of 1D nonplanar graphene nanoribbon, namely dodecatwistarene imides featuring twelve linearly fused benzene rings, was obtained by bottom‐up synthesis of palladium‐catalyzed Stille coupling and C‐H activation. Single‐crystal X‐ray diffraction analyses revealed that it displays a zigzag‐twisted conformation caused by steric hindrance between imide groups...
Mon Nov 18, 2019 19:04
A game of strain: The synthesis of highly strained natural products provides unexpected opportunities for the development of new reactions and strategies. In the synthesis of (+)‐[5]‐ladderanoic acid unexpected strain release driven transformations were uncovered, thus requiring a drastic revision of the synthetic design that ultimately led to the development of a novel stepwise cyclobutane assembly by an allylboration/Zweifel olefination sequence. Abstract The synthesis of structurally complex...
Mon Nov 18, 2019 19:04
A molecular calcium hydride effects the two electron reduction of polyaromatic hydrocarbons, including naphthalene (E0 = ‐3.1 V).
Mon Nov 18, 2019 16:19
A surface digging effect of supported Ni NPs on an amorphous N‐doped carbon is described, during which the surface‐loaded Ni NPs etch and sink into the carbon support underneath to prevent sintering. The sinking Ni NPs could be transformed into thermodynamically stable and active metal‐defect sites for activation of C−H bonds for methane oxidation by simply elevating temperature. Abstract A surface digging effect of supported Ni NPs on an amorphous N‐doped carbon is described, during which...
Mon Nov 18, 2019 15:53
The acid treatment of TiO2 weakens the bonding of octahedral chains in anatase TiO2, rendering the formation of amorphous TiO2 buffer layer on the surface of anatase TiO2. This amorphous TiO2 buffer layer contains rich oxygen vacancies, which increase the donor density of TiO2. Abstract The ability to effectively transfer photoexcited electrons and holes is an important endeavor toward achieving high‐efficiency solar energy conversion. Now, a simple yet robust acid‐treatment strategy is used...
Mon Nov 18, 2019 15:52
Ultrafast heating addresses the thermodynamic contradiction of precursor volatilization during polymerization and leads to strongly adhesive carbon nitride on electrodes with a gradient C‐rich texture. Charge separation and mobility are accelerated and a remarkable photocurrent and a record cathodic electrochemiluminescence efficiency are observed. Abstract Semiconducting polymeric carbon nitride (CN) has drawn wide attention ranging from photocatalysis to more recent biosensing owing to unique...
Mon Nov 18, 2019 15:50
The nanocluster Au56(TBBT)34 was synthesized. X‐ray crystallography revealed a defective kernel layer stacking mode different from that shared by a magic series of nanoclusters, Au28(TBBT)20, Au36(TBBT)24, Au44(TBBT)28, Au52(TBBT)32, and Au56(TBBT)34. Not only the size but also the odevity of the kernel layer number influences both polarity and photoluminescence of the metal nanoclusters. Abstract Kernel atoms of Au nanoclusters are packed layer‐by‐layer along the [001] direction with every...
Mon Nov 18, 2019 15:49
My own way: Thiophenylazobenzene is a sulfur‐based azoheteroarene photoswitch with impressive fatigue resistance, photoisomerization efficiency, and highly selective photoconversion. Its (Z)‐isomer adopts an unusual orthogonal geometry stabilized by an intramolecular lone‐pair⋅⋅⋅π interaction governing the ultrafast photoisomerization, which requires a mechanism involving significant movement along the inversion reaction coordinate. Abstract Azoheteroarene photoswitches have attracted attention...
Mon Nov 18, 2019 15:49
Blink and you'll miss it: A rationally designed small‐molecule label comprising fluorogenic and self‐blinking features has been designed and synthesized for bioorthogonal chemistry and super‐resolution microscopy in living cells. Abstract Recent developments in fluorescence microscopy call for novel small‐molecule‐based labels with multiple functionalities to satisfy different experimental requirements. A current limitation in the advancement of live‐cell single‐molecule localization microscopy...
Mon Nov 18, 2019 14:37
Beyond natural: A protein catalyst was engineered to perform selective halogenation of a fragment of martinelline, a pharmaceutically relevant non‐native substrate. Directed evolution of non‐heme iron halogenase WelO5* afforded a variant with an up to 400‐fold higher apparent k cat and a 290‐fold higher TTN for this target substrate than the wildtype enzyme while achieving high stereo‐ and regioselectivity (>99 %). Abstract Non‐heme iron halogenases are synthetically valuable biocatalysts...
Mon Nov 18, 2019 14:29
Activation code: The aromatic nitrogen atoms of heteroarylaldehydes are activated by carbene catalysts to react with ketone electrophiles. A broad scope of cyclic N,O‐acetal products are afforded in good to excellent yields and optical purities. The reaction involves the formation of an aza‐fulvene acylazolium intermediate. Several products exhibit excellent antibacterial activities and are valuable in the development of novel agrichemicals. Abstract The aromatic nitrogen atoms of heteroarylaldehydes...
Mon Nov 18, 2019 14:29
Partner up: Photocatalysis offers a one‐step strategy to selectively functionalize the benzylic positions of electron‐rich arenes with alcohols. It merges the photoredox activation of arenes with copper(II)‐mediated oxidation of the resulting benzylic radicals, enabling the introduction of benzylic C−O bonds with high site selectivity, chemoselectivity, and functional‐group tolerance using only two equiv of the alcohol coupling partner. Abstract Methods that enable the direct C−H alkoxylation...
Mon Nov 18, 2019 14:27
Material gains: A general bottom‐up topochemical strategy has been developed to synthesize solution‐processable two‐dimensional transition‐metal phosphides, which exhibit semiconducting features and superior activity towards the oxygen evolution reaction. Notably, Co2P is a p‐type semiconductor, with a hole mobility of 20.8 cm2 V−1 s−1 at 300 K in field‐effect transistors. Abstract Transition‐metal phosphides (TMPs) have emerged as a fascinating class of narrow‐gap semiconductors and electrocatalysts....
Mon Nov 18, 2019 14:27
Fast dynamic STEM combined with a spatio‐temporal image denoising algorithm is employed to explore the structure and stability of Pt clusters on carbon, which represents a highly relevant catalysis system. At room temperature, dynamic amorphous 2D structures are found, while above ≈300 °C, the clusters transform into a crystalline state. Abstract Little is known about metallic clusters consisting merely of a dozen of atoms or even less, despite of their importance in catalysis and crystal nucleation....
Mon Nov 18, 2019 14:26
Easy as 1‐2‐3: A chemoselective Pd0‐catalyzed alkyne‐directed [2+2+1] spiroannulation of aryl iodides with bromophenol derivatives has been established for the assembly of spirocycle‐embedded polycyclic frameworks. This two‐component reaction proceeds via remote C−H cleavage, biaryl cross‐coupling, and arene dearomatization. Abstract Palladium‐catalyzed alkene‐directed cross‐coupling of aryl iodide with another aryl halide through C−H arylation opens a unique avenue for unsymmetrical biaryl‐derived...
Mon Nov 18, 2019 14:25
It's a trap! The simultaneous detection and quantitation of multiple different biothiols in a single sample by EPR spectroscopy has been demonstrated using a technique termed EPR thiol‐trapping. This technique was used to monitor the efflux of glutathione and cysteine from HepG2 cells. Abstract Biothiols, such as glutathione (GSH), homocysteine (Hcy), and cysteine (Cys), coexist in biological systems with diverse biological roles. Thus, analytical techniques that can detect, quantify, and distinguish...
Mon Nov 18, 2019 14:24
Going polar: An efficient route was reported to generate polar‐functionalized, crosslinkable, self‐healing, and photoresponsive polyolefins with thermoplastic, elastomeric, and thermosetting properties. Abstract The nonpolar nature of polyolefins is one of their biggest limitations. Now, an efficient route to generate polar‐functionalized, crosslinkable, self‐healing, photoresponsive polyolefins with thermoplastic, elastomeric, and thermosetting properties is reported. Tunable amounts of carboxylic...
Mon Nov 18, 2019 14:23
Based on a truxene a chiral monkey saddle shaped polyaromatic hydrocarbon (PAH) with three eight‐membered rings was accessible in only three synthetic steps. The enantiomers were separated by chiral HPLC and investigated photophysically. Abstract A contorted polycyclic aromatic hydrocarbon (PAH) in the shape of a monkey saddle has been synthesized in three steps from a readily available truxene precursor. The monkey saddle PAH is consisting of three five‐, seven six‐, and three eight‐membered...
Mon Nov 18, 2019 14:23
Dynamic duo: The combination of electrochemistry and photochemistry allows the generation of highly reactive catalytic intermediates without the need for a chemical oxidant. This photoelectrocatalytic strategy thus accessed the elusive reactivity of flavins for oxidizing unactivated aliphatic alcohols. HAT=hydrogen‐atom transfer. Abstract Riboflavin‐derived photocatalysts have been extensively studied in the context of alcohol oxidation. However, to date, the scope of this catalytic methodology...
Mon Nov 18, 2019 14:20
The TCICA/KF approach to oxidative fluorination of heteroatoms has emerged as a surprisingly simple, safe, and versatile surrogate to classically challenging fluorination reactions. The mild syntheses of metastable difluoro(aryl)(perfluoroalkyl)‐λ4‐sulfanes and selanes is reported and preliminary evidence is provided that difluoro(aryl)(trifluoro‐methyl)‐λ4‐sulfanes may act as fluorinating reagents. Abstract The TCICA/KF approach to oxidative fluorination of heteroatoms has emerged as a surprisingly...
Mon Nov 18, 2019 14:19
Bring the heat! Supramolecular assemblies provide an elegant way to fabricate organic photothermal materials with enhanced stability and photothermal conversion efficiency, which can be termed supramolecular photothermal effects. By elaborating the inherent mechanisms, the supramolecular photothermal effects are expected to greatly benefit the design of novel high‐efficiency photothermal materials and their applications in a variety of fields. Abstract Supramolecular assemblies have been very...
Mon Nov 18, 2019 14:19
A de novo first collective total synthesis of 11‐deoxylandomycins is reported. A signature step is featured by the Pd‐catalyzed asymmetric addition of alcohol to ene‐alkoxyallenes that assembles oligomeric 2,3,6‐trideoxyoligosaccharides. The unique feature of the protocol is illustrated by a flexible access to various natural 11‐deoxylandomycins as well as non‐natural analogues.
Mon Nov 18, 2019 13:55
A substituted poly(phenylacetylene) derivative with two hydroxymethyl groups at the meta position of the side phenyl ring (PPAHB) was examined as a conformation‐switchable helical spring polymer that responds to solvent and heat stimuli in a precisely controlled manner. The intramolecular hydrogen bonding that gives rise to the helical structure of the polymer was destroyed and regenerated by adjusting the hydrogen bonding strength (pKHB) values of various combinations of solvents or by varying the...
Sun Nov 17, 2019 20:49
Transition metal‐catalyzed ethylene copolymerization with polar monomers is a highly challenging reaction. After decades of research, the scope of suitable comonomer substrates has expanded from special to fundamental polar monomers and, recently, to 1,1‐disubstituted ethylenes. In this contribution, we aim to describe a direct and tandem strategy to realize ethylene copolymerization with various 1,2‐disubstituted ethylenes. The direct route is sensitive to steric effects from both the comonomers...
Sun Nov 17, 2019 16:59
A photoresponsive chiral catalyst based on an oligotriazole‐functionalized unidirectional molecular motor has been developed for stereodivergent anion binding catalysis. The motor function controls the helical chirality of supramolecular assemblies with chloride anions, which by means of chirality transfer enables the enantioselective addition of a silyl ketene acetal nucleophile to oxocarbenium cations. Reversal of stereoselectivity (up to 142% Δee) was achieved through rotation of the motor core...
Sun Nov 17, 2019 16:58
Direct alkylation of C(sp2)‐H bonds in order to convert an aldehyde into a ketone is a notorious transformation, due to the laborious challenge of the formation of ketyl or acyl radicals. Herein, we report a green, cheap, metal‐free and efficient method for the hydroacylation of olefins in water. This photochemical protocol utilizes phenylglyoxylic acid, a commercially available small organic molecule, as the photoinitiator, water as the solvent and household fluorescent lamps as the irradiation...
Sun Nov 17, 2019 16:48
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