Evidence of 14-3-3 proteins contributing to kinetochore integrity and chromosome congression during mitosis.

The 14-3-3 family of proteins are conserved across eukaryotes and serve myriad important regulatory functions of the cell. Homo/heterodimers of these protein homologs, majorly recognize their ligands via conserved motifs to modulate the localization and functions of those effector ligands. In most of the genetic backgrounds of Saccharomyces cerevisiae, disruption of both 14-3-3 homologs (Bmh1 and Bmh2) are either lethal or survive with severe growth defects showing gross chromosomal missegregation and prolonged cell cycle arrest. To elucidate their contributions to chromosome segregation, in this work we investigated their centromere/kinetochore-related functions. Analysis of appropriate deletion mutants shows that Bmh isoforms have cumulative and unshared isoform-specific contributions in maintaining the proper integrity of the kinetochore ensemble. Consequently, bmh mutant cells exhibited perturbations in kinetochore-microtubule (KT-MT) dynamics, characterized by kinetochore declustering, mis-localization of kinetochore proteins, and Mad2-mediated transient G2/M arrest. These defects also caused an asynchronous chromosome congression in bmh mutants during metaphase. In summary, this report advances the knowledge on contributions of budding yeast 14-3-3 proteins in chromosome segregation by demonstrating their roles in kinetochore integrity and chromosome congression.

Formation of partially embedded Au nanostructures: Ion beam irradiation on thin film.

The Au partially embedded nanostructure (PEN) is synthesized by ion irradiation on an Au thin film deposited on a glass substrate using a 50 keV Ar ion. Scanning electron microscopy results show ion beam-induced restructuring from irregularly shaped nanostructures (NSs) to spherical Au NSs, and further ion irradiation leads to the formation of well-separated spherical nanoparticles. Higuchi's algorithm of surface analysis is utilized to find the evolution of surface morphology with ion irradiation in terms of the Hurst exponent and fractal dimension. The Au PEN is evidenced by Rutherford backscattering spectrometry and optical studies. Also, the depth of the mechanism behind synthesized PEN is explained on the basis of theoretical simulations, namely, a unified thermal spike and a Monte Carlo simulation consisting of dynamic compositional changes (TRIDYN). Another set of plasmonic NSs was formed on the surface by thermal annealing of the Au film on the substrate. Glucose sensing has been studied on the two types of plasmonic layers: nanoparticles on the surface and PEN. The results reveal the sensing responses of both types of plasmonic layers. However, PEN retains its plasmonic behavior as the NSs are still present after washing with water, which demonstrates the potential for reusability. RESEARCH HIGHLIGHTS: Synthesis of PENs by ion irradiation Utilization of Higuchi's algorithm to explore the surface morphology. Unified thermal spike and TRIDYN simulations being used to explain the results. Glucose is only used as a test case for reusability of substrate.

Study on damage of Gd2O3-CeO2 under electronic energy loss: comparison between bulk-like and nanostructure.

To understand the physical phenomena responsible for radiation damage of the materials used in nuclear reactors, and thus study their operation life and/or efficiency, it is required to simulate the conditions by exposing the materials to energetic ions. Ceria (CeO2) has been proposed as one of the inert matrices for the transmutation of minor actinides in the futuristic inert matrix fuel (IMF) concept. The inert matrix should also contain burnable poison to compensate for the initial reactivity of fuel. In this context, gadolinium (Gd) is an excellent burnable poison with a high neutron absorption cross-section. In view of this, Gd2O3-CeO2 nano-powders were synthesized and sintered at 800 °C and 1300 °C to obtain different grain sizes and morphologies. FESEM and TEM were carried out to study the grain size of pristine pellets. The sintered pellets were irradiated with 80-MeV Ag ions (electronic energy loss (Se) regime) at room temperature to emulate the effect of fission fragments. For analysis of the effect of grain size on the irradiation-induced structural degradation at different fluences, GIXRD and Raman spectroscopy were performed. Significantly large damage has been observed for the smaller grain-sized samples (sintered at 800 °C) as compared to the large grain-sized sample (sintered at 1300 °C). Neither of the samples amorphized under the present experimental conditions as indicated by the presence of the Raman-active T2g mode (centred at 462 cm-1) and all the XRD peaks of fluorite cubic structure up to the highest fluence employed (1 × 1014 ions cm-2). X-ray photoelectron spectroscopy results demonstrate that Ce4+ to Ce3+ and vacancy-related isolated clusters are the main defects produced in the systems. The radiation tolerance behaviour of the samples is understood with the help of thermal spike simulation, which indicates higher transient lattice temperatures with longer duration in the smaller grain-sized sample upon irradiation. Gd-doped ceria thus possesses good radiation stability in the Se regime, indicating its potential for application in IMFs.

Surface nanocrystallization enhances the biomedical performance of additively manufactured stainless steel.

Additive manufacturing enables the fabrication of patient-specific implants of complex geometries. Although selective laser melting (SLM) of 316L stainless steel (SS) is well established, post-processing is essential to preparing high-performance biomedical implants. The goal of this study was to investigate surface mechanical attrition treatment (SMAT) as a means to enhance the electrochemical, biomechanical, and biological performances of 316L SS fabricated by SLM in devices for the repair of bone tissues. The SMAT conditions were optimized to induce surface nanocrystallization on the additively manufactured samples. SMAT resulted in a thicker oxide layer, which provided corrosion resistance by forming a passive layer. The fretting wear results showed that the rate of wear decreased after SMAT owing to the formation of a harder nanostructured layer. Surface modification of the alloy by SMAT enhanced its ability to support the attachment and proliferation of pre-osteoblasts in vitro. The study of the response in vivo to the additively manufactured alloy in a critical-sized cranial defect murine model revealed enhanced interactions with the cellular components after the alloy was subjected to SMAT without inducing any adverse immune response. Taken together, the results of this work establish SMAT of additively manufactured metallic implants as an effective strategy for engineering next-generation, high-performance medical devices for orthopedics and craniomaxillofacial applications.

The selfish yeast plasmid exploits a SWI/SNF-type chromatin remodeling complex for hitchhiking on chromosomes and ensuring high-fidelity propagation.

Extra-chromosomal selfish DNA elements can evade the risk of being lost at every generation by behaving as chromosome appendages, thereby ensuring high fidelity segregation and stable persistence in host cell populations. The yeast 2-micron plasmid and episomes of the mammalian gammaherpes and papilloma viruses that tether to chromosomes and segregate by hitchhiking on them exemplify this strategy. We document for the first time the utilization of a SWI/SNF-type chromatin remodeling complex as a conduit for chromosome association by a selfish element. One principal mechanism for chromosome tethering by the 2-micron plasmid is the bridging interaction of the plasmid partitioning proteins (Rep1 and Rep2) with the yeast RSC2 complex and the plasmid partitioning locus STB. We substantiate this model by multiple lines of evidence derived from genomics, cell biology and interaction analyses. We describe a Rep-STB bypass system in which a plasmid engineered to non-covalently associate with the RSC complex mimics segregation by chromosome hitchhiking. Given the ubiquitous prevalence of SWI/SNF family chromatin remodeling complexes among eukaryotes, it is likely that the 2-micron plasmid paradigm or analogous ones will be encountered among other eukaryotic selfish elements.

Tuning LSPR of Thermal Spike-Induced Shape-Engineered Au Nanoparticles Embedded in Si3N4 Thin-Film Matrix for SERS Applications.

While gold nanoparticles (Au NPs) are widely used as surface-enhanced Raman spectroscopy (SERS) substrates, their agglomeration and dynamic movement under laser irradiation result in the major drawback in SERS applications, viz., the repeatability of SERS signals. We tune the optical and structural properties of size- and shape-modified Au NPs embedded in a thin silicon nitride (Si3N4) matrix by intense electronic excitation with swift heavy ion (SHI) irradiation with the aim of overcoming this classical SERS disadvantage. We demonstrate the shape evolution of a single layer of Au NPs inserted between amorphous Si3N4 thin films under fluences of 120 MeV Au9+ ions ranging between 1 × 1011 and 1 × 1013 ions cm-2. This shape modification results in the gradual blue shift of the localized surface plasmon resonance (LSPR) dip until 1 × 1012 ions/cm2 and then a sudden diminishment at 1 × 1013 ions/cm2. Finite domain time difference (FDTD) simulations further justify our experimental optical spectra. The dynamical NP aggregation and dissolution, in addition to NP elongation and deformation at different fluences, are noted from 2D grazing incidence small-angle X-ray scattering (GISAXS) profiles, as well as cross-sectional transmission electron microscopy (X-TEM). The systematic shape evolution of metal NPs embedded in the insulating matrix is shown to be due to thermal spike-induced localized melting and a localized pressure hike upon SHI irradiation. Utilizing this specific control over the characteristics of Au NPs, viz., shape, size, interparticle gap, and corresponding optical response via SHI irradiation, we demonstrate their applications as very stable SERS substrates, where the separation between NPs and analyte does not alter under laser illumination. Thus, these irradiated SERS active substrates with controlled NP size and gap provide the optimal conditions for creating localized electromagnetic hotspots that amplify the SERS signals, which do not alter with time or laser exposure. We found that the film irradiated with 1 × 1011 exhibits the highest SERS intensity due to its optimal NP size distribution and shape. Thus, not only our study provides a SERS substrate for stable and repeatable signals but also the understanding depicted here opens new research avenues in designing SERS substrates, photovoltaics, optoelectronic devices, etc. with ion beam irradiation.

Evidence of kinesin motors involved in stable kinetochore assembly during early meiosis.

During mitosis, the budding yeast, kinetochores remain attached to microtubules, except for a brief period during S phase. Sister-kinetochores separate into two clusters (bilobed organization) upon stable end-on attachment to microtubules emanating from opposite spindle poles. However, in meiosis, the outer kinetochore protein (Ndc80) reassembles at the centromeres much later after prophase I, establishing new kinetochore-microtubule attachments. Perhaps due to this, despite homolog bi-orientation, we observed that the Ndc80 are linearly dispersed between spindle poles during metaphase I of meiosis. The presence of end-on attachment marker Dam1 as a cluster near each pole suggests one of the other possibilities that the pole-proximal and pole-distal kinetochores are attached end-on and laterally to the microtubules, respectively. Colocalization studies of kinetochores and kinesin motors suggest that budding yeast kinesin 5, Cin8, and Kip1 perhaps localize to the end-on attached kinetochores while kinesin 8 and Kip3 resides at all the kinetochores. Our findings, including kinesin 5 and Ndc80 coappearance after prophase I and reduced Ndc80 levels in cin8 null mutant, suggest that kinesin motors are crucial for kinetochore reassembly and stability during early meiosis. Thus, this work reports yet another meiosis specific function of kinesin motors.

Plasma Membrane Channel TRPM4 Mediates Immunogenic Therapy-Induced Necrosis.

Several emerging therapies kill cancer cells primarily by inducing necrosis. As necrosis activates immune cells, potentially, uncovering the molecular drivers of anticancer therapy-induced necrosis could reveal approaches for enhancing immunotherapy efficacy. To identify necrosis-associated genes, we performed a genome-wide CRISPR-Cas9 screen with negative selection against necrosis-inducing preclinical agents BHPI and conducted follow-on experiments with ErSO. The screen identified transient receptor potential melastatin member 4 (TRPM4), a calcium-activated, ATP-inhibited, sodium-selective plasma membrane channel. Cancer cells selected for resistance to BHPI and ErSO exhibited robust TRPM4 downregulation, and TRPM4 reexpression restored sensitivity to ErSO. Notably, TRPM4 knockout (TKO) abolished ErSO-induced regression of breast tumors in mice. Supporting a broad role for TRPM4 in necrosis, knockout of TRPM4 reversed cell death induced by four additional diverse necrosis-inducing cancer therapies. ErSO induced anticipatory unfolded protein response (a-UPR) hyperactivation, long-term necrotic cell death, and release of damage-associated molecular patterns that activated macrophages and increased monocyte migration, all of which was abolished by TKO. Furthermore, loss of TRPM4 suppressed the ErSO-induced increase in cell volume and depletion of ATP. These data suggest that ErSO triggers initial activation of the a-UPR but that it is TRPM4-mediated sodium influx and cell swelling, resulting in osmotic stress, which sustains and propagates lethal a-UPR hyperactivation. Thus, TRPM4 plays a pivotal role in sustaining lethal a-UPR hyperactivation that mediates the anticancer activity of diverse necrosis-inducing therapies. SIGNIFICANCE: A genome-wide CRISPR screen reveals a pivotal role for TRPM4 in cell death and immune activation following treatment with diverse necrosis-inducing anticancer therapies, which could facilitate development of necrosis-based cancer immunotherapies.

A sustainable smart production model for partial outsourcing and reworking.

Smart production plays a significant role to maintain good business terms among supply chain players in different situations. Adjustment in production uptime is possible because of the smart production system. The management may need to reduce production uptime to deliver products ontime. But, a decrement in production uptime reduces the projected production quantity. Then, the management uses a limited investment for pursuing possible alternatives to maintain production schedules and the quality of products. This present study develops a mathematical model for a smart production system with partial outsourcing and reworking. The market demand for the product is price dependent. The study aims to maximize the total profit of the production system. Even in a smart production system, defective production rate may be less but unavoidable. Those defective products are repairable. The model is solved by classical optimization. Results show that the application of a variable production rate of the smart production for variable market demand has a higher profit than a traditional production (52.65%) and constant demand (12.45%).

A Catalytic Asymmetric Hydrolactonization.

Despite recent advancements in the development of catalytic asymmetric electrophile induced lactonization reactions of olefinic carboxylic acids, the archetypical hydrolactonization has long remained an unsolved and well-recognized challenge. Here, we report the realization of a catalytic asymmetric hydrolactonization using a confined imidodiphosphorimidate (IDPi) Brønsted acid catalyst. The method is operationally simple, scalable, and compatible with a wide variety of substrates. Its potential is showcased with concise syntheses of the sesquiterpenes (-)-boivinianin A and (+)-gossonorol. Through in-depth physicochemical and DFT analyses, we derive a nuanced picture of the mechanism and enantioselectivity of this reaction.

Silk composite interfacial layer eliminates rebleeding with chitosan-based hemostats.

Chitosan foams are among the approved hemostats for pre-hospital hemorrhagic control but suffer from drawbacks related to mucoadhesiveness and rebleeding. Herein, we have developed a designer bilayered hemostatic foam consisting of a bioactive layer composed of silica particles (≈300 nm) and silk fibroin to serve as the tissue interfacing component on a chitosan foam. The foam composition was optimized based on the in vitro clotting behavior and cytocompatibility of individual components. In vivo analysis in a rat model demonstrated that the developed hemostat could achieve rapid clotting (31 ± 4 s), similar to a chitosan-based hemostat, but the former had significantly lower blood loss. Notably, removal of the bilayered hemostat prevented rebleeding, unlike the chitosan foam, which was associated with markedly higher incidences of rebleeding (50 %) and left behind material residue. Thus, the designer bilayered foam presented here is a potent inducer of blood clotting whilst affording easy removal with minimal rebleeding.

Product outsourcing policy for a sustainable flexible manufacturing system with reworking and green investment.

Production of defective products is a very general phenomenon. But backorder and shortages occur due to this defective product, and it hampers the manufacturer's reputation along with customer satisfaction. That is why, these outsourced products supply, a portion of required products for in-line production. This study develops a flexible production model that reworks repairable defective products and outsources products to prevent backlogging. A percentage of total in-line production is defective products, which is random, and those defective products are repairable. A green investment helps the reworking process, which has a direct impact on the market demand for products. A classical optimization solves the profit maximization model, and a numerical method proves the global optimal solutions. Sensitivity analysis, managerial insights, and discussions provide the highlights and decision-making strategies for the applicability of this model.

Real-Time Polymerase Chain Reaction-Based Detection and Quantification of Hepatitis B Virus DNA.

Hepatitis B virus (HBV) is a significant cause of liver disease worldwide. It can lead to acute or chronic infections, making individuals highly susceptible to fatal cirrhosis and liver cancer. Accurate detection and quantification of HBV DNA in the blood are essential for diagnosing and monitoring HBV infection. The most common method for detecting HBV DNA is real-time PCR, which can be used to detect the virus and assess the viral load to monitor the response to antiviral therapy. Here, we describe a detailed protocol for the detection and quantification of HBV DNA in human serum or plasma using an IVD-marked real-time PCR-based kit. The kit uses primers and probes that target the highly conserved core region of the HBV genome and can accurately quantify all HBV genotypes (A, B, C, D, E, F, G, H, I, and J). The kit also includes an endogenous internal control to monitor possible PCR inhibition. This assay runs for 40 cycles, and its cutoff is 38 Ct. For the quantification of HBV DNA in clinical samples, a set of 5 quantification standards is provided with the kit. The standards contain known concentrations of HBV-specific DNA that are calibrated against the 4th WHO International Standard for HBV DNA for the nucleic acid test (NIBSC code 10/266). The standards are used to validate the functionality of the HBV-specific DNA amplification and to generate a standard curve, allowing the quantification of HBV DNA in a sample. HBV DNA as low as 2.5 IU/mL was detected using the PCR kit. The high sensitivity and reproducibility of the kit make it a powerful tool in clinical laboratories, aiding healthcare professionals in effectively diagnosing and managing HBV infections.

Recent Advancement of Functional Hydrogels toward Diabetic Wound Management.

Wound healing is a dynamic, orchestrated process comprising partially overlapping phases of hemostasis, inflammation, proliferation, and remodeling. This programmed process, dysregulated in diabetic individuals, results in chronic diabetic wounds. The normal process of healing halts at the inflammatory stage, and this prolonged inflammatory phase is characteristic of diabetic wounds. There are a few U.S. Food & Drug Administration approved skin substitutes; dermal matrixes are commercially available to manage diabetic wounds. However, expensiveness and nonresponsiveness in a few instances are the major limitations of such modalities. To address the issues, several treatment strategies have been exploited to treat chronic wounds; among them hydrogel-based systems showed promise due to favorable properties such as excellent absorption capabilities, porous structure, tunable mechanical strength, and biocompatibility. In the past two decades, hydrogels have become one of the most acceptable systems in the field of wound dressing material, offering single functionality to multifunctionality. This review focuses on the advancement of functional hydrogels explored for diabetic wound management. The process of diabetic wound healing is discussed in the light of the normal healing process, and the role of macrophages in the process is explained. This review also discusses the different approaches to treat diabetic wounds using functional hydrogels, along with their future opportunities.

Sth1, the ATPase subunit of the RSC chromatin remodeler has important roles in stress response and DNA damage repair in the pathogenic fungi Candida albicans.

Candida albicans, the most prevalent fungal pathogen, exists as a commensal in the human host. It is subjected to myriad physiological stress conditions in different host niches, which jeopardizes its fitness to survive and propagate as an established commensal. C. albicans has highly labile chromatin which gets remodeled in response to the stress conditions to facilitate the expression of several stress-responsive genes. Several epigenetic factors including histone variants, histone modifiers and chromatin remodelers that define the chromatin architecture play crucial roles in the regulation of the stress-responsive genes in this organism. Here we investigated the roles of the ATP-dependent chromatin remodeler RSC (Remodel the Structure of Chromatin) in several stress responses in C. albicans, by targeting the key ATPase component, Sth1, given its profound and similar roles exist in Saccharomyces cerevisiae. We have unraveled the crucial roles of the RSC complex (Sth1) in maintaining cell wall integrity and fighting against osmotic and oxidative stresses. We found that the mutant conditionally depleted of Sth1 was sensitive to the cell wall disrupting agents, and the mutant without exposure to any stressor accumulated higher chitin content in the cell wall as a defense mechanism to restore the cell wall integrity. Further, this was supported by the phosphorylation of MAPK1 protein Mkc1, which happens due to activation of the cell wall integrity pathway PKC1. We also observed the Sth1 mutant to be sensitive to oxidative and osmotic stresses in vitro, which are very important and imparted by the host defense mechanism. This suggests that the mutant could get attenuated and hence become less virulent than the wild-type when loss of function of Sth1 happens. We also found that Sth1 has a crucial role in maintaining genomic integrity as sth1 mutant cells accumulate extensive DNA damages and show the loss in cell viability. Overall this work suggests that Sth1 has an important role in fighting against some of the clinically relevant and physiologically important stresses. It also has a crucial role in fighting against stress to the genomic integrity and hence functions in DNA damage repair.

Catalytic Asymmetric Spirocyclizing Diels-Alder Reactions of Enones: Stereoselective Total and Formal Syntheses of α-Chamigrene, ß-Chamigrene, Laurencenone C, Colletoic Acid, and Omphalic Acid.

We disclose a general catalytic enantioselective Diels-Alder reaction of exo-enones with dienes to give spirocyclanes. The obtained products feature highly congested quaternary stereogenic spirocenters and are used in concise total and formal syntheses of several sesquiterpenes, including of α-chamigrene, ß-chamigrene, laurencenone C, colletoic acid, and omphalic acid. The stereo- and regioselectivities of our spirocyclizing cycloaddition are effectively controlled by strongly acidic and confined imidodiphosphorimidate catalysts. Computational studies shed light on the origin of reactivity and selectivity.

Emerging roles of SWI/SNF remodelers in fungal pathogens.

Fungal pathogens constantly sense and respond to the environment they inhabit, and this interaction is vital for their survival inside hosts and exhibiting pathogenic traits. Since such responses often entail specific patterns of gene expression, regulators of chromatin structure contribute to the fitness and virulence of the pathogens by modulating DNA accessibility to the transcriptional machinery. Recent studies in several human and plant fungal pathogens have uncovered the SWI/SNF group of chromatin remodelers as an important determinant of pathogenic traits and provided insights into their mechanism of function. Here, we review these studies and highlight the differential functions of these remodeling complexes and their subunits in regulating fungal fitness and pathogenicity. As an extension of our previous study, we also show that loss of specific RSC subunits can predispose the human fungal pathogen Candida albicans cells to filamentous growth in a context-dependent manner. Finally, we consider the potential of targeting the fungal SWI/SNF remodeling complexes for antifungal interventions.

Pharmacological studies of rhizomes of extract of Cyperus tegetum, emphasized on anticancer, anti-inflammatory and analgesic activity.

ETHNOPHARMACOLOGICAL RELEVANCE: With over 950 species, Cyperus is one of the most promising health boosting genera in the Cyperaceae family. Traditional uses of Cyperus sp. have been described for gastrointestinal blood abnormalities, menstrual irregularities, and inflammatory diseases, among others. Cyperus tegetum Roxb belonging to Cyperaceae family, is used in traditional medicine to treat skin cancers. AIM OF THE STUDY: The present study was carried out to explore the potential effect of the extract of the plant Cyperus tegetum against different pharmacological activity namely inflammatory, analgesic activity as well as skin cancer activity in mice. MATERIALS AND METHODS: Cytotoxicity of the extract was measured by MTT and Live/death assay on HeLa cell line. Skin cancer was induced by 7,12-dimethylbenz(a) anthracene (DMBA) and 12-O-tetradecanoylphorbol-13-acetate (TPA) in mice to measure its effects. RESULT: Stigmasterol and some poly phenolic compounds are identified using HPTLC process from the methanol extract of the rhizome of the plant Cyperus tegetum (CT-II). After confirmation of the presence of different polyphenolic compound and triterpenoids in the extract, it was subject to MTT and Live/death assay on HeLa cell line. From the observation it could be concluded that the IC50 of the extract is 300 µg/ml. Thus, the CTII was evaluated further for its in vivo anticancer property. In the tumorigenesis study, the number of tumor growths, the area and weight of the tumor significantly decreases with increment in the dose of CT-II extract and some elevated enzyme release in renal (creatinine, urea) as well as hepatic (AST, ALT, ALP) enzymes are also controlled with the increased dose of the same extract. The elevated enzyme release may be due to cancer induced rupture of the plasma and cellular damage. This CT-II extract also exhibits some other pharmacological activity like anti-inflammatory and analgesic activity. CONCLUSION: As metabolic activation via carcinogens and inflammation response plays important role in development of cancer, antioxidant, anti-inflammatory and analgesic properties can be correlated with anti-cancer properties. Taken all the above studies, it was illustrated that the extract of Cyperus tegetum might be a promising compound to reduce skin cancer risk.

Minichromosome maintenance proteins in eukaryotic chromosome segregation.

Minichromosome maintenance (Mcm) proteins are well-known for their functions in DNA replication. However, their roles in chromosome segregation are yet to be reviewed in detail. Following the discovery in 1984, a group of Mcm proteins, known as the ARS-nonspecific group consisting of Mcm13, Mcm16-19, and Mcm21-22, were characterized as bonafide kinetochore proteins and were shown to play significant roles in the kinetochore assembly and high-fidelity chromosome segregation. This review focuses on the structure, function, and evolution of this group of Mcm proteins. Our in silico analysis of the physical interactors of these proteins reveals that they share non-overlapping functions despite being copurified in biochemically stable complexes. We have discussed the contrasting results reported in the literature and experimental strategies to address them. Taken together, this review focuses on the structure-function of the ARS-nonspecific Mcm proteins and their evolutionary flexibility to maintain genome stability in various organisms.

Copper-Catalyzed Synthesis of Terminal vs. Fluorine-Substituted N-Allenamides via Addition of Diazo Compounds to Terminal Ynamides.

A copper-mediated coupling reaction between ynamides and diazo-compounds to produce N-allenamides is reported for the first time. This method enables facile and rapid access to terminal N-allenamides by using commercially available TMS-diazomethane with wide functional group compatibility on the nitrogen. Furthermore, the ubiquity of molecules containing a fluorine moiety in medicine, in agricultural, and material science requires the continuous search of new building blocks, including this unique surrogate. The CuI/diazo protocol was successfully applied to the synthesis of fluorine-substituted N-allenamides. DFT calculations provided insights in the mechanism involved.