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Presents three papers delivered at the meeting of national representatives to the Committee on the Teaching of Chemistry of the International Union of Pure and Applied Chemistry. (PR)

Discusses types of laboratory waste materials and methods for their safe disposal. (MLH)

An efficient method to prepare enantiopure (S)-glycidyl pivalate from (R)-epichlorohydrin and pivalic acid is reported. This work provides an alternative to the synthesis of this important building block from readily available and inexpensive materials.

The group 11 hydride clusters [Ag6H4(dppm)4(OAc)2] and [Cu3H(dppm)3(OAc)2] (dppm = 1,1-bis(diphenylphosphino)methane) were synthesized from the reaction of M(OAc) (M = Ag, Cu) with Ph2SiH2, in the presence of the bidentante phosphine ligand, dppm. [Ag6H4(dppm)4(OAc)2] is the first structurally characterized homometallic polyhydrido silver cluster to be isolated. Both clusters catalyze the hydrosilylation of (,–unsaturated) ketones. Notably, this represents the first example of hydrosilylation with an authentic silver hydride complex. The larger copper hydride clusters [Cu10H10(DBEphos)4] (DBEphos = oxydi-2,1-phenylene)bis(diphenylphosphino)) and [Cu14H14(DBFphos)5] (DBFphos = 4,6-bis(diphenylphosphino)dibenzofuran) have also been isolated. Preliminary data suggest that there is a positive correlation between the bite angle of the bidentate phosphine and the size of the cluster generated. Finally, the copper selenoate cluster [Cu13H10(SePh)3(PPh3)7] was generated from the in situ reduction of Ph2Se2 by [CuH(PPh3)]6 and represents a facile method of selenium incorporation into copper clusters.Further studies into Cu cluster formation is examined through the reactivity of RSH (R = CH2CH2Ph, n-Bu, n-C12H25) with Cu(II) under anhydrous conditions, which results in the formation of “Atlas-sphere”-type copper thiolate nanoclusters, including [Cu12(SR’)6Cl12][(Cu(R’SH))6] (R’ = nBu) and [H(THF)2]2[Cu17(SR”)6Cl13(THF)2(R”SH)3] (R” = CH2CH2Ph). Consistent with the X-ray crystallographic data, the XANES edge energies of these clusters suggest they are constructed exclusively with Cu(I) ions. Given these results, as well as past work on Cu(II)/thiol reactivity, it is argued that Cu(0) cannot be accessed by reaction of Cu(II) with a thiol, and that previous reports of Cu(0)-containing clusters synthesized in this manner are likely erroneous.The generation of a partially metallic Cu cluster was realized through the synthesis of the mixed-valent organometallic cluster, [Cu20(CCPh)12(OAc)6)], which was isolated from the reduction of Cu(OAc) with Ph2SiH2 in the presence of phenylacetylene. This cluster is a rare example of a two-electron copper superatom, and the first to feature a tetrahedral [Cu4]2+ core. [Cu20(CCPh)12(OAc)6)] can be readily immobilized on dry, partially-dehydroxylated silica. Both materials are effective catalysts for [3+2] cycloaddition reactions between alkynes and azides (i.e., “Click” reactions) at room temperature. Significantly, neither material requires any pre-treatment for activation toward catalysis.To further expand the scope of first row transition metal clusters with partial metallic character, a re-examination of the synthesis and of monolayer-protected Cox(SCH2CH2Ph)m nanoclusters is addressed. These clusters were reportedly formed by the reaction of CoCl2 with NaBH4 in the presence of HSCH2CH2Ph, and were suggested to contain between 25 and 30 Co atoms. However, there is no evidence to support the existence of these large clusters in the reaction mixture. Instead, this reaction results in the relatively clean formation of the Co(II) coordination complex [Co10(SCH2CH2Ph)16Cl4]. This complex represents the first example of a thiolate-protected Co(II) T3 supertetrahedral cluster.The ketimide ligand has been shown to stabilize high oxidation states of the transition metals, though it has recently been hypothesized that this ligand may be useful in the generation of low-valent species as well. The isolation of the Pd(0) containing, ketimide-stabilized cluster Pd7(N=CtBu2)6 reinforces this hypothesis. Similar reactivity studies with Pt results in the isolation of the Pt(II) complex, Pt(N=CtBu2)2. Additionally, the low-valent Fe-ketimide cluster, [Fe4(N=CPh2)6], is isolated. These complexes have been previously reported by former Hayton group members, though their syntheses and characterization have been significantly improved. Pt(N=CtBu2)2 exhibits exceptionally short Pt-N distances (av. Pt-N = 1.815 Å) and an unusually deshielded 195Pt chemcial shift (δPt = -629 ppm) with a large 1JPtN coupling constant (537 Hz). Pd7(N=CtBu2)6 features a mixed-valent, hexagonal planar [Pd7]6+ core stabilized by six ketimide ligands. Finally, [Fe4(N=CPh2)6] displays fully delocalized metal bonding electrons, which gives rise to a ground spin-state of S = 7 and single molecule magnet behavior.

In marine continental margins, high saturations of natural gas hydrate are observed within the gas hydrate stability zone, but the gas migration pathways to the hydrate reservoir are not often clear. We focus on a site in Green Canyon Block 955 (GC 955) in the Gulf of Mexico, where gas hydrate occurs in a 35 m-thick reservoir with saturations of 79-93% in numerous centimeter- to decimeter-thick sandy silt layers and little to no gas hydrate in the interbedded cm to decimeter-thick clayey silt layers. Different datasets (well logging, coring, and seismic data) suggest different types of potential methane migration mechanisms. For example, relatively high particulate organic carbon content in the reservoir and the microbial methane source indicated by gas chromatography and methane isotopes suggest gas might be made locally and migration could occur through dissolved methane sources or water advection. In contrast, the visible deeply rooted faults intersecting the gas hydrate reservoir and the gas pockets adjacent to the faults on seismic data suggest that free gas may migrate directly into the reservoir. We tested three different mechanisms to form gas hydrate at GC 955: short-range methane diffusion, short-range methane diffusion coupled with upward water advection, and free gas flow. The 1-D and 2-D numerical models show that both the short-range migration and the upward water advection are not enough to form high saturations gas hydrate at GC 955, and that free gas flow is required to form the high saturations of gas hydrate observed at GC 955.

Massive volumes of gas are sequestered within gas hydrate in subsurface marine sediments in the Gulf of Mexico. Methane associated with gas hydrate is a potentially important economic resource and a significant reservoir of carbon within the global carbon cycle. Nevertheless, uncertainties remain about the genetic source (e.g., microbial, thermogenic) and possible migration history of natural gas incorporated into hydrate. Previous studies have primarily used the hydrocarbon molecular (CH4/C2H6+) and isotopic (δ13C-CH4, δ2H-CH4) compositions of natural gas to address these uncertainties. However, hydrocarbon tracers are altered by mixing, oxidation, secondary methanogenesis, or fluid migration, which presents challenges when deciphering the mechanisms responsible for methane formation and accumulation. To evaluate the genetic source of natural gases from Green Canyon Block 955 (GC 955), east of the Sigsbee escarpment, we collected and analyzed samples from the first pressurized hydrate-bearing sediment cores collected from a coarse-grained hydrate reservoir in the Gulf of Mexico. Gas samples were analyzed for hydrocarbon (C1- C5), major gas (e.g., N2, CO2), and noble gas (He-Xe) abundance and isotopic (e.g., δ13C-CH4, δ2H-CH4, δ13C-CO2, δ15N-N2, 3He/4He, 4He/20Ne) compositions. We determined that natural gas in hydrates from this location are predominantly of primary microbial origin (conservatively at least 76%) and are formed by the hydrogenotrophic (CO2 reduction) methanogenesis pathway. We also note increased thermogenic proportions (~6%) in a hydrate-bearing layer below the main hydrate-bearing interval (separated by a 5 m water-bearing layer). Our results suggest that microbial methane may be abundant below the base of gas hydrate stability at GC 955.

PURPOSE Docetaxel and abiraterone acetate plus prednisone or prednisolone (AAP) both improve survival when commenced alongside standard of care (SOC) androgen deprivation therapy in locally advanced or metastatic hormone-sensitive prostate cancer. Thus, patient-reported quality of life (QOL) data may guide treatment choices. METHODS A group of patients within the STAMPEDE trial were contemporaneously enrolled with the possibility of being randomly allocated to receive either docetaxel + SOC or AAP + SOC. A mixed-model assessed QOL in those who had completed at least one QLQ-C30 + PR25 questionnaire. The primary outcome measure was difference in global-QOL (QLQ-C30 Q29&30) between patients allocated to docetaxel + SOC or AAP + SOC over the 2 years after random assignment, with a predefined criterion for clinically meaningful difference of > 4.0 points. Secondary outcome measures included longitudinal comparison of functional domains, pain, and fatigue, plus global-QOL at defined timepoints. RESULTS Five hundred fifteen patients (173 docetaxel + SOC and 342 AAP + SOC) were included. Baseline characteristics, proportion of missing data, and mean baseline global-QOL scores (docetaxel + SOC 77.8 and AAP + SOC 78.0) were similar. Over the 2 years following random assignment, the mean modeled global-QOL score was +3.9 points (95% CI, +0.5 to +7.2; P = .022) higher in patients allocated to AAP + SOC. Global-QOL was higher for patients allocated to AAP + SOC over the first year (+5.7 points, 95% CI, +3.0 to +8.5; P < .001), particularly at 12 (+7.0 points, 95% CI, +3.0 to +11.0; P = .001) and 24 weeks (+8.3 points, 95% CI, +4.0 to +12.6; P < .001). CONCLUSION Patient-reported QOL was superior for patients allocated to receive AAP + SOC, compared with docetaxel + SOC over a 2-year period, narrowly missing the predefined value for clinical significance. Patients receiving AAP + SOC reported clinically meaningful higher global-QOL scores throughout the first year following random assignment.

Introduction A better understanding of how menthol cigarette flavoring and ENDS impact smoking initiation, cessation, and transitions between tobacco products could help elucidate the potential impact of a U.S. menthol ban on combustible tobacco products. Methods A multistate transition model was applied to data on 23,232 adults from Waves 1–4 (2013–2017) of the Population Assessment of Tobacco and Health Study (analysis was conducted in 2020–2021). Transition rates among never, noncurrent, nonmenthol versus menthol cigarette, ENDS, and dual everyday/someday use were estimated, as were transition-specific hazard ratios for age, sex, race/ethnicity, education, and income. Results Non-Hispanic Blacks who smoked menthol discontinued smoking at a much lower rate than those who smoked nonmenthol (hazard ratio=0.43, 95% CI=0.29, 0.64), but there was no statistically significant difference in the discontinuation rates among non-Hispanic Whites (hazard ratio=0.97, 95% CI=0.80, 1.16) or Hispanics (hazard ratio=0.81, 95% CI=0.56, 1.16). Non-Hispanic Whites who smoked menthol were more likely to become dual users than those who smoked nonmenthol (hazard ratio=1.43, 95% CI=1.14, 1.80). Young adults initiated menthol smoking at a higher rate than older adults (age 18–24 years versus ≥55 years: hazard ratio=2.45, 95% CI=1.44, 4.15) but not nonmenthol smoking (hazard ratio=1.02, 95% CI=0.62, 1.69). There were differences by sex in the impact of menthol flavor on smoking initiation and discontinuation but little difference by education or income. Conclusions Sociodemographic differences in product transitions should be accounted for when estimating the potential impact of a menthol ban.

Eukaryotic chromosomes contain regions of varying accessibility, yet DNA replication factors must access all regions. The first replication step is loading MCM complexes to license replication origins during the G1 cell cycle phase. It is not yet known how mammalian MCM complexes are adequately distributed to both accessible euchromatin regions and less accessible heterochromatin regions. To address this question, we combined time-lapse live-cell imaging with immunofluorescence imaging of single human cells to quantify the relative rates of MCM loading in euchromatin and heterochromatin throughout G1. We report here that MCM loading in euchromatin is faster than that in heterochromatin in early G1, but surprisingly, heterochromatin loading accelerates relative to euchromatin loading in middle and late G1. This differential acceleration allows both chromatin types to begin S phase with similar concentrations of loaded MCM. The different loading dynamics require ORCA-dependent differences in origin recognition complex distribution. A consequence of heterochromatin licensing dynamics is that cells experiencing a truncated G1 phase from premature cyclin E expression enter S phase with underlicensed heterochromatin, and DNA damage accumulates preferentially in heterochromatin in the subsequent S/G2 phase. Thus, G1 length is critical for sufficient MCM loading, particularly in heterochromatin, to ensure complete genome duplication and to maintain genome stability.In this study the authors have, for the first time, quantified DNA replication origin licensing dynamics and distribution in single cells at subnuclear resolution. The cell cycle and DNA replication fields have long appreciated that origin licensing is both absolutely essential for replication and that licensing is strictly confined to G1 phase. The biochemical process of origin licensing- which is the DNA loading of MCM complexes- is known in considerable detail. What has never been explored in any system, is the dynamics of origin licensing itself. Here the authors define the dynamics of human MCM loading at different times within G1 in both euchromatin and heterochromatin, and explore the consequences of those dynamics for genome stability.

Pathfinding elephants are moving through human dominated landscapes, often across international boundaries, thereby playing a vital role in connecting protected areas. Their movements are a call to action to not only understand their spatial requirements but to urgently work towards innovative ways to make people’s livelihoods compatible with conservation outcomes so that coexistence and connected landscapes can prevail. We discuss the first three phases of a long-term strategy to conserve elephant corridors whilst incorporating the socio-economic needs of the people that share the landscape with them. We present a comprehensive satellite-tracking history of elephants across two transfrontier conservation areas (TFCA), represented by Great Limpopo- and Lubombo TFCAs and involving four countries (South Africa, Zimbabwe, Mozambique and Eswatini) to flag where linking corridors exist. We use innovative cafeteria-style experiments to understand which elephant-unpalatable plants would offer lucrative alternative income streams to farmers living in human–elephant-conflict hotspots. The most suitable unpalatable plants are chosen based not only on whether they are unpalatable to elephants, but also on their life history traits and growth prerequisites. We consider a combination of potential economic values (food, essential oil, medicinal and bee fodder value) to ensure that selected plants would accommodate changing economic markets. Lastly, we highlight the importance of combining food security measures with ensuring people’s safety by means of deploying rapid-response units. By implementing these three phases as part of a longer-term strategy, we draw closer to ensuring the protection of bioregions to achieve biodiversity objectives at a landscape scale.

Criticizes early specialization in O-level courses in Britain and advocates the introduction of combined science at this level. This option would expose students to physics, chemistry and biology and avoid the present specialization that is common when these subjects are taken separately. (JR)

Background. C-reactive protein (CRP) is an independent biomarker of systemic inflammation and a predictor of future cardiovascular disease (CVD). More than just a pure bystander, CRP directly interacts with endothelial cells to decrease endothelial nitric oxide synthase (eNOS) expression and bioactivity, decrease nitric oxide (NO) production, and increase the release of vasoconstrictors and adhesion molecules. Race is significantly associated with CRP levels and CVD risks. With aerobic exercise, the vessel wall is exposed to chronic high laminar shear stress (HiLSS) that shifts the endothelium phenotype towards an anti-inflammatory, antioxidant, antiapoptotic, and antiproliferative environment. Thus, the purpose of this study was to assess the racial differences concerning the CRP-induced effects in endothelial cells and the potential role of HiLSS in mitigating these differences. Methods. Human umbilical vein endothelial cells (HUVECs) from four African American (AA) and four Caucasian (CA) donors were cultured and incubated under the following conditions: (1) static control, (2) CRP (10 μg/mL, 24 hours), (3) CRP receptor (FcγRIIB) inhibitor followed by CRP stimulation, (4) HiLSS (20 dyne/cm2, 24 hours), and (5) HiLSS followed by CRP stimulation. Results. AA HUVECs had significantly higher FcγRIIB receptor expression under both basal and CRP incubation conditions. Blocking FcγRIIB receptor significantly attenuated the CRP-induced decrements in eNOS expression only in AA HUVECs. Finally, HiLSS significantly counteracted CRP-induced effects. Conclusion. Understanding potential racial differences in endothelial function is important to improve CVD prevention. Our results shed light on FcγRIIB receptor as a potential contributor to racial differences in endothelial function in AA.

Aims Sleep apnoea and congestive heart failure (CHF) commonly co‐exist, but their interaction is unclear. Metabolomics may clarify their interaction and relationships to outcome. Methods and results We assayed 372 circulating metabolites and lipids in 1919 and 1524 participants of the Framingham Heart Study (FHS) (mean age 54 ± 10 years, 53% women) and Women's Health Initiative (WHI) (mean age 67 ± 7 years), respectively. We used linear and Cox regression to relate plasma concentrations of metabolites and lipids to echocardiographic parameters; CHF and its subtypes heart failure with reduced ejection fraction (HFrEF) and heart failure with preserved ejection fraction (HFpEF); and sleep indices. Adenine dinucleotide phosphate (ADP) associated with left ventricular (LV) fractional shortening; phosphocreatine with LV wall thickness; lysosomal storage molecule sphingomyelin 18:2 with LV mass; and nicotine metabolite cotinine with time spent with an oxygen saturation less than 90% (β = 2.3 min, P = 2.3 × 10−5). Pro‐hypertrophic metabolite hydroxyglutarate partly mediated the association between LV wall thickness and HFpEF. Central sleep apnoea was significantly associated with HFpEF (P = 0.03) but not HFrEF (P = 0.5). There were three significant metabolite canonical variates, one of which conferred protection from cardiovascular death [hazard ratio = 0.3 (0.11, 0.81), P = 0.02]. Conclusions Energetic metabolites were associated with cardiac function; energy‐ and lipid‐storage metabolites with LV wall thickness and mass; plasma levels of nicotine metabolite cotinine were associated with increased time spent with a sleep oxygen saturation less than 90%, a clinically significant marker of outcome, indicating a significant hazard for smokers who have sleep apnoea.

Background: MIDD0301 is an oral asthma drug candidate that binds GABAA receptors on airway smooth muscle and immune cells. Objective: The objective of this study is to identify and quantify MIDD0301 metabolites in vitro and in vivo and determine the pharmacokinetics of oral, IP, and IV administered MIDD0301. Methods: In vitro conversion of MIDD0301 was performed using liver and kidney microsomes/S9 fractions followed by quantification using liquid chromatography-tandem mass spectrometry (LC-MS/MS). A LC-MS/MS method was developed using synthesized standards to quantify MIDD0301 and its metabolites in urine and feces. Blood, lung, and brain were harvested from animals that received MIDD0301 by oral, IP, and IV administration, followed by LCMS/ MS quantification. Imaging mass spectrometry was used to demonstrate the presence of MIDD0301 in the lung after oral administration. Results: MIDD0301 is stable in the presence of liver and kidney microsomes and S9 fractions for at least two hours. MIDD0301 undergoes conversion to the corresponding glucuronide and glucoside in the presence of conjugating cofactors. For IP and IV administration, unconjugated MIDD0301 together with significant amounts of MIDD0301 glucoside and MIDD0301 taurine were found in urine and feces. Less conjugation was observed following oral administration, with MIDD0301 glucuronide being the main metabolite. Pharmacokinetic quantification of MIDD0301 in blood, lung, and brain showed very low levels of MIDD0301 in the brain after oral, IV, or IP administration. The drug half-life in these tissues ranged between 4-6 hours for IP and oral and 1-2 hours for IV administration. Imaging mass spectrometry demonstrated that orally administered MIDD0301 distributes uniformly in the lung parenchyma. Conclusion: MIDD0301 undergoes no phase I and moderate phase II metabolism.

OBJECTIVES: To evaluate the effects of different polyphenols and solvents on dentin collagen’s crosslinking interactions and biostabilization against MMPs and collagenase degradation. METHODS: Two polyphenols [proanthocyanidin (PA) and quercetin (QC)] with different water solubility were prepared as treatment solutions using ethanol (EtOH) or dimethyl sulfoxide (DMSO) as solvents. 6-um-thick dentin films were microtomed from dentin slabs of third molars. Following demineralization, films or slabs were subject to 60-s treatment (PA or QC) or no treatment (control) with subsequent extended-rinse with original solvent (EtOH or DMSO) or distilled water (DW). Collagen crosslinking interactions were assessed by FTIR. Biostability was assessed through endogenous MMPs activity via confocal laser scanning microscopy, and exogenous collagenase degradation via weight loss, hydroxyproline release and SEM. Finally, direct collagenase inactivation was also evaluated. Data were analyzed by three-way ANOVA and post-hoc tests (α=0.05%). RESULTS: Distinct effects of two polyphenols and solvents on collagen crosslinking and biostabilization were observed. Higher crosslinking and biostability efficacy occurred with PA than QC (p < 0.001) that demonstrated negligible collagen interactions. With DMSO solvent, efficacy results were significantly reduced with both polyphenols (p < 0.05). DMSO-rinse further weakened interactions of PA with collagen, diminishing biostability (p < 0.05). Low biostability was detected with QC and DW-rinse, suggesting direct enzymatic inhibition due to physical presence in collagen. SIGNIFICANCE: Collagen crosslinking interactions and biostability depend on polyphenol chemical characteristics. Treatment-solution solvents may affect interactions between polyphenols and collagen, specifically, DMSO showed detrimental effects on collagen crosslinking and biostability and should be used with caution.

Texturally complex minerals can provide critical information on dynamic hydrothermal processes. This study combines cathodoluminescence (CL), laser ablation-inductively coupled plasma-mass spectrometry (LA–ICP–MS), and high-resolution femtosecond laser ablation multi-collector inductively coupled plasma mass spectrometry (fs–LA–MC–ICP–MS) analyses to document textures, in situ Sr-Nd isotope systematics, and trace element compositions of texturally complex scheelite from the Yangjiashan W deposit, South China. The major motivation for this contribution was to reveal the correlation between CL response, textures, and trace element concentrations; document the origin of various REE fractionation patterns; and characterize grain-scale in situ variability of Sr-Nd isotopes of scheelite. Five sub-types of scheelite from both stages, including Sch1 and Sch2 from Stage 1, and Sch3 to Sch5 from Stage 2, are identified. CL images feature complex oscillatory, patchy, and evidence for coupled dissolution-reprecipitation reaction. These scheelites precipitated from reduced fluids and are close to end-member in composition, with Mo concentrations below 46 ppm. Concentrations of other elements vary, e.g., Sr (36–1025 ppm), Nd (8–351 ppm), and Na (7–300 ppm). LA–ICP–MS element maps reveal a large variability in REE concentrations among oscillatory zones and no consistent behavior between REE, Sr and Mo concentration, and CL intensity. Four distinct chondrite-normalized REE fractionation patterns are recognized: LREE-enriched, MREE-enriched, HREE-enriched, and flat patterns. Complex Eu anomalies (δEu = 0.2 to 20.7) are recognized among the five sub-types and are commonly observed within individual grains. Fluid compositions, different substitution mechanisms (i.e., Ca2+ + W6+ = REE3+ + Nb5+, and 2Ca2+ = REE3+ + Na+, 3Ca2+ = 2REE3++ ☐Ca, where ☐Ca is a Ca-site vacancy), primary-secondary processes (i.e., oscillatory and dissolution-reprecipitation, respectively), all contribute to the variation in REE fractionation patterns. Local fluctuation in fluid pH is responsible for the complex Eu anomalies. In situ Sr and Nd isotope signatures for the five sub-types of scheelite show relatively large ranges, i.e., the initial 87Sr/86Sr ratios range from 0.71336 to 0.72617, and the initial εNd values ranging from –24.9 to –7.7, suggesting a source derived from a mixture of magmatic-hydrothermal fluids and the Neoproterozoic slate. Decreasing 87Sr/86Sr ratios from Sch2 to Sch5 record decreasing fluid-rock interaction intensity. Large variation of εNd(t) values (–24.9 to –7.7) of scheelite with oscillatory zoning textures may relate to changes of Sm/Nd ratio of scheelite and contamination from wall rock with inhomogeneous Nd isotope composition. This study highlights the importance of performing coupled LA–ICP–MS mapping and in situ Sr-Nd isotope analyses on sample material that has been characterized in detail at the micrometer scale.

This report describes the significance of the kinetic parameters (k-values) obtained from the analysis of dynamic positron emission tomography (PET) scans using the Hawkins model describing the pharmacokinetics of sodium fluoride ([18F]NaF) to understand bone physiology. Dynamic [18F]NaF PET scans may be useful as an imaging biomarker in early phase clinical trials of novel drugs in development by permitting early detection of treatment-response signals that may help avoid late-stage attrition.

The 2A protein of Theiler’s murine encephalomyelitis virus (TMEV) acts as a switch to stimulate programmed −1 ribosomal frameshifting (PRF) during infection. Here we present the X-ray crystal structure of TMEV 2A and define how it recognises the stimulatory RNA element. We demonstrate a critical role for bases upstream of the originally predicted stem-loop, providing evidence for a pseudoknot-like conformation and suggesting that the recognition of this pseudoknot by beta-shell proteins is a conserved feature in cardioviruses. Through examination of PRF in TMEV-infected cells by ribosome profiling, we identify a series of ribosomal pauses around the site of PRF induced by the 2A-pseudoknot complex. Careful normalisation of ribosomal profiling data with a 2A knockout virus facilitated the identification, through disome analysis, of ribosome stacking at the TMEV frameshifting signal. These experiments provide unparalleled detail of the molecular mechanisms underpinningTheilovirusprotein-stimulated frameshifting.

The RAS-regulated RAF–MEK1/2–ERK1/2 pathway promotes cell proliferation and survival and RAS and BRAF proteins are commonly mutated in cancer. This has fuelled the development of small molecule kinase inhibitors including ATP-competitive RAF inhibitors. Type I and type I½ ATP-competitive RAF inhibitors are effective in BRAFV600E/K-mutant cancer cells. However, in RAS-mutant cells these compounds instead promote RAS-dependent dimerisation and paradoxical activation of wild-type RAF proteins. RAF dimerisation is mediated by two key regions within each RAF protein; the RKTR motif of the αC-helix and the NtA-region of the dimer partner. Dimer formation requires the adoption of a closed, active kinase conformation which can be induced by RAS-dependent activation of RAF or by the binding of type I and I½ RAF inhibitors. Binding of type I or I½ RAF inhibitors to one dimer partner reduces the binding affinity of the other, thereby leaving a single dimer partner uninhibited and able to activate MEK. To overcome this paradox two classes of drug are currently under development; type II pan-RAF inhibitors that induce RAF dimer formation but bind both dimer partners thus allowing effective inhibition of both wild-type RAF dimer partners and monomeric active class I mutant RAF, and the recently developed “paradox breakers” which interrupt BRAF dimerisation through disruption of the αC-helix. Here we review the regulation of RAF proteins, including RAF dimers, and the progress towards effective targeting of the wild-type RAF proteins

Progress in genome sequencing now enables the large-scale generation of reference genomes. Various international initiatives aim to generate reference genomes representing global biodiversity. These genomes provide unique insights into genomic diversity and architecture, thereby enabling comprehensive analyses of population and functional genomics, and are expected to revolutionize conservation genomics., Trends in Ecology & Evolution, 37 (3), ISSN:0169-5347, ISSN:1872-8383

Herein, we report the design and synthesis of inhibitors of Mycobacterium tuberculosis (Mtb) phospho-MurNAc-pentapeptide translocase I (MurX), the first membrane-associated step of peptidoglycan synthesis, leveraging the privileged structure of the sansanmycin family of uridylpeptide natural products. A number of analogues bearing hydrophobic amide modifications to the pseudo-peptidic end of the natural product scaffold were generated that exhibited nanomolar inhibitory activity against Mtb MurX and potent activity against Mtb in vitro. We show that a lead analogue bearing an appended neopentylamide moiety possesses rapid antimycobacterial effects with a profile similar to the frontline tuberculosis drug isoniazid. This molecule was also capable of inhibiting Mtb growth in macrophages where mycobacteria reside in vivo and reduced mycobacterial burden in an in vivo zebrafish model of tuberculosis.

The fresh flavor of a beer brand is one of its most important quality parameters and should be retained as long as possible through shelf-life. Early stages of beer production can have significant impacts on beer flavor stability. The use of cereal adjuncts – either malted or unmalted – is now widespread practice in brewing. This laboratory mashing study investigated the impacts of incorporating common solid adjuncts (corn and rice) at increasing grist percentages (0-50%) on flavor stability indicators measured in wort. Sweet worts were analysed for metal ion levels (ICP-MS), thiol content (RP-HPLC), oxidative stability (EPR spectroscopy), staling aldehydes (HS-SPME-GC-MS), trihydroxy fatty acids (GC-FID), t-2-nonenal potential (GC-MS), color and thiobarbituric acid (TBI). Mashing conditions for each formulation were adjusted in order to achieve target FAN values. Unmalted rice or corn adjuncts significantly reduced the total metal ion content, color, TBI and staling aldehydes in sweet worts at 50% adjunct incorporation (p