Search

The Wittig reaction can be used for late stage functionalization of proteins and peptides to ligate glycans, pharmacophores, and many other functionalities. In this manuscript, we modified 160 000 N-terminal glyoxaldehyde peptides displayed on phage with the Wittig reaction by using a biotin labeled ylide under conditions that functionalize only 1% of the library population. Deep-sequencing of the biotinylated and input populations estimated the rate of conversion for each sequence. This “deep conversion” (DC) from deep sequencing correlates with rate constants measured by HPLC. Peptide sequences with fast and slow reactivity highlighted the critical role of primary backbone amides (N–H) in accelerating the rate of the aqueous Wittig reaction. Experimental measurement of reaction rates and density functional theory (DFT) computation of the transition state geometries corroborated this relationship. We also collected deep-sequencing data to build structure–activity relationship (SAR) models that can predict the DC value of the Wittig reaction. By using these data, we trained two classifier models based on gradient boosted trees. These classifiers achieved area under the ROC (receiver operating characteristic) curve (ROC AUC) of 81.2 ± 0.4 and 73.7 ± 0.8 (90–92% accuracy) in determining whether a sequence belonged to the top 5% or the bottom 5% in terms of its reactivity. This model can suggest new peptides never observed experimentally with ‘HIGH’ or ‘LOW’ reactivity. Experimental measurement of reaction rates for 11 new sequences corroborated the predictions for 8 of them. We anticipate that phage-displayed peptides and related mRNA or DNA-displayed substrates can be employed in a similar fashion to study the substrate scope and mechanisms of many other chemical reactions., 160 000 peptides displayed on phage were subjected to the Wittig reaction with a biotinylated ylide. Deep-sequencing estimated the conversion rate for each sequence and unveiled the relationship between sequences and the rate of the Wittig reaction.

A new process was developed to recover high specific activity (no carrier added) 99Mo from electron-accelerator irradiated U3O8 or uranyl sulfate targets. The process leverages a novel solvent extraction scheme to recover Mo using di(2-ethylhexyl) phosphoric acid following uranium and transuranics removal with tri-n-butyl phosphate. An anion-exchange concentration column step provides a final purification, generating pure 99Mo intended for making 99Mo/99mTc generators. The process was demonstrated with irradiated uranium targets resulting in more than 95% 99Mo recovery and without presence of fission products or actinides in the product.

In this study, density functional theory (DFT) and time dependent density functional theory (TD-DFT) are used to investigate the stabilities and spectral properties [IR, UV–vis, and two-photon absorption (2PA)] of two sets of modified RNA nucleobase tautomers. The modifications introduce either a sulfur or selenium atom to form an isothiazolo[4,3-d]pyrimidine or isoselenazolo[4,3-d]pyrimidine heterocyclic core, respectively. The relative stabilities of both sets of modified tautomers determined with B3LYP/6-31++G(d,p) reveal that in water (with a polarizable continuum model), the 6-keto-2-amino tautomer of guanine and the rare 4-imino-2-keto tautomer of cytosine may be present at significant populations, whereas the 6-enol-2-amino tautomer of guanine is more common in the gas phase. The identification of these modified tautomers is possible due to the natural differences in their vibrational modes and hence IR spectra. Furthermore, the photophysical properties of both these sets of modified tautomers indicate that excitation and emission energies are shifted relative to their more abundant form in both one photon absorption and emission and 2PA spectra, as determined at the B3LYP/6-31++G(d,p) and CAM-B3LYP/aug-cc-pVDZ levels of theory, respectively. Even though the 2PA cross sections in water for all of the species are small (0.3–2.3 GM), the modified cytosine tautomer shows promise, as its cross section is larger than the more dominant form. The spectral separation between the dominant form and the tautomers of isoselenazole and isothiazole modified cytosine and guanine are relatively similar, suggesting both modifications could be useful in elucidating the tautomers from their more abundant counterparts.

The production of very pure molybdenum, free of Re even at ultratrace levels, is extremely important in meeting target purity specifications during the production of 99Mo for medical applications. ...

The inorganic, normal-phase sorbents alumina, titania, and zirconia were evaluated and screened for the separation of Ba, La, 228Ra, 228Ac, and 212Pb in a dilute acid matrix. The results show that ...

The stabilization of silicon(II) and germanium(II) dihydrides by an intramolecular Frustrated Lewis Pair (FLP) ligand, PB, i Pr2 P(C6 H4 )BCy2 (Cy=cyclohexyl) is reported. The resulting hydride complexes [PB{SiH2 }] and [PB{GeH2 }] are indefinitely stable at room temperature, yet can deposit films of silicon and germanium, respectively, upon mild thermolysis in solution. Hallmarks of this work include: 1) the ability to recycle the FLP phosphine-borane ligand (PB) after element deposition, and 2) the single-source precursor [PB{SiH2 }] deposits Si films at a record low temperature from solution (110 °C). The dialkylsilicon(II) adduct [PB{SiMe2 }] was also prepared, and shown to release poly(dimethylsilane) [SiMe2 ]n upon heating. Overall, this study introduces a "closed loop" deposition strategy for semiconductors that steers materials science away from the use of harsh reagents or high temperatures.

Electron-donating N-heterocyclic carbenes (Lewis bases, LB) and electron-accepting Lewis acids (LA) have been used in tandem to yield donor-acceptor complexes of inorganic tetrelenes LB·EH2·LA (E = Si, Ge, and Sn). Herein, we introduce the new germanium (II) dihydride adducts ImMe2·GeH2·BH3 (ImMe2 = (HCNMe)2C:) and ImiPr2Me2·GeH2·BH3 (ImiPr2Me2 = (MeCNiPr)2C:), with the former complex containing nearly 40 wt % germanium. The thermal release of bulk germanium from ImMe2·GeH2·BH3 (and its deuterated isotopologue ImMe2·GeD2·BD3) was examined in solution, and a combined kinetic and computational investigation was undertaken to probe the mechanism by which Ge is liberated. Moreover, the thermolysis of ImMe2·GeH2·BH3 in solution cleanly affords conformal nanodimensional layers of germanium as thin films of variable thicknesses (20-70 nm) on silicon wafers. We also conducted a computational investigation into potential decomposition pathways for the germanium(II)- and tin(II)-dihydride complexes NHC·EH2·BH3 (NHC = [(HCNR)2C:]; R = 2,6-iPr2C6H3 (Dipp), Me, and H; and E = Ge and Sn). Overall, this study introduces a mild and convenient solution-only protocol for the deposition of thin films of Ge, a widely used semiconductor in materials research and industry.

Additive manufacturing/3D printing is a rapidly maturing field with potential advantages for the fabrication of chemical processing equipment. A demonstration of the molybdenum solvent-extr...

Solvent extraction is used widely for chemical separations and environmental remediation. Although the kinetics and efficiency of this process rely upon the formation of ion–extractant complexes, it has proven challenging to identify the location of ion–extractant complexation within the solution and its impact on the separation. Here, we use tensiometry and X-ray scattering to characterize the surface of aqueous solutions of lanthanide chlorides and the water-soluble extractant bis(2-ethylhexyl) phosphoric acid (HDEHP), in the absence of a coexisting organic solvent. These studies restrict ion–extractant interactions to the aqueous phase and its liquid–vapor interface, allowing us to explore the consequences that one or the other is the location of ion–extractant complexation. Unexpectedly, we find that light lanthanides preferentially occupy the liquid–vapor interface. This contradicts our expectation that heavy lanthanides should have a higher interfacial density since they are preferentially extracted by HDEHP in solvent extraction processes. These results reveal the antagonistic role played by ion–extractant complexation within the aqueous phase and clarify the advantages of complexation at the interface. Extractants in common use are often soluble in water, in addition to their organic phase solubility, and similar effects to those described here are expected to be relevant to a variety of separations processes., Observations of lanthanide ions and HDEHP extractants at the aqueous−vapor interface suggest an unexpected role for aqueous complexation and speciation in the process of liquid−liquid extraction.

The Wittig reaction can be used for late stage functionalization of proteins and peptides to ligate glycans, pharmacophores, and many other functionalities. In this manuscript, we modified 160,000 N-terminal glyoxaldehyde peptides displayed on phage with the Wittig reaction by biotin labeled ylide under conditions that functionalize only 1% of the library population. Deep-sequencing of the biotinylated and input populations estimated the rate of conversion for each sequence. This “deep conversion” (DC) from deep sequencing correlates with rate constants measured by HPLC. Peptide sequences with fast and slow reactivity highlighted a critical role of primary backbone amides (N-H) in accelerating the rate of the aqueous Wittig reaction. Experimental measurement of reaction rates and density functional theory (DFT) computation of the transition state geometries corroborated this relationship. We also collected deep-sequencing data to build structure activity relationship (SAR) models that can predict DC value of the Wittig reaction. By using this data, we trained two classifier models based on Gradient Boosted trees. These classifiers achieved area under the ROC (Receiver Operating Characteristic) Curve (ROC AUC) of 81.2 ± 0.4 and 73.7 ± 0.8 (90–92% accuracy) in determining whether a sequence belonged to the top 5% or the bottom 5% in terms of its reactivity. We have deployed our learned models as a publicly available web app: http://44.226.164.95/ We anticipate that phage-displayed peptides and related mRNA or DNA-displayed substrates can be employed in a similar fashion to study the substrate scope and mechanisms of many other chemical reactions.

Expanded low-carbon baseload power production through the use of nuclear fission can be enabled by recycling long-lived actinide isotopes within the nuclear fuel cycle. This approach provides the benefits of (a) more completely utilizing the energy potential of mined uranium, (b) reducing the footprint of nuclear geological repositories, and (c) reducing the time required for the radiotoxicity of the disposed waste to decrease to the level of uranium ore from one hundred thousand years to a few hundred years. A key step in achieving this goal is the separation of long-lived isotopes of americium (Am) and curium (Cm) for recycle into fast reactors. To achieve this goal, a novel process was successfully demonstrated on a laboratory scale using a bank of 1.25-cm centrifugal contactors, fabricated by additive manufacturing, and a simulant containing the major fission product elements. Americium and Cm were separated from the lanthanides with over 99.9% completion. The sum of the impurities of the Am/Cm product stream using the simulated raffinate was found to be 3.2 × 10−3 g/L. The process performance was validated using a genuine high burnup used nuclear fuel raffinate in a batch regime. Separation factors of nearly 100 for 154Eu over 241Am were achieved. All these results indicate the process scalability to an engineering scale.

This letter describes the on-going SAR efforts to develop PLD1, PLD2 and dual PLD1/2 inhibitors with improved physiochemical and disposition properties as well as securing intellectual property position. Previous PLD inhibitors, based on a triazaspiro[4.5]decanone core proved to be highly selective PLD2 inhibitors, but with low plasma free fraction (rat, human fu 65 mL/min/kg) and very short half-lives in vivo (t1/2 3 h), and led to the first issued US patent claiming composition of matter for small molecule PLD inhibitors.

The synthesis of the first bismuth-containing macromolecules that exhibit phosphorescence in the solid state and in the presence of oxygen is reported. These red emissive high molecular weight polymers (>300 kDa) feature benzobismoles appended to a hydrocarbon scaffold, and were built via an efficient ring-opening metathesis (ROMP) protocol. Moreover, our general procedure readily allows for the formation of cross-linked networks and block copolymers. Attaining stable red phosphorescence with non-toxic elements remains a challenge and, thus, our new class of soluble (processable) polymeric phosphor is of great interest. Furthermore, the formation of bismuth-rich cores within organic-inorganic block copolymer spherical micelles is possible, leading to patterned arrays of bismuth in the film state.

Targeted radionuclide therapy generally relies on the chelation of select short-lived isotopes such as 177Lu and 67Cu. The majority of Lu(III) and Cu(II) chelate structural information is derived from solid state diffraction data. Herein, the complexes Lu(DOTA)−, Cu(NOTA)− were examined in solution using EXAFS for the first time. Both ligands were fully deprotonated and coordinated to the metal with four and three carboxylic sites for Lu(DOTA)− and Cu(NOTA)−, respectively. Near-neighbor correlations from nitrogen atoms on the macrocyclic cages were also visible in the spectra in addition to the adjacent carbon backbones. Coordination numbers, bond distances, and Debye-Waller factors are reported and discussed alongside differences with known crystal structures.

Aims To describe the effect of alcohol policy on the incidence of intensive care unit (ICU) admissions associated with hazardous and harmful alcohol use in the Northern Territory (NT) of Australia DESIGN, SETTING AND PARTICIPANTS: Before and after analysis of admissions to NT ICUs between April 2018 and September 2019, extending on both a descriptive study describing hazardous and harmful alcohol use and single-centre analyses of harm minimization policies. After exclusions, 2281 (83%) admissions were analysed, 20.3% of which were associated with hazardous and harmful alcohol use. Measurements Primary outcome was the incidence of admissions associated with hazardous and harmful alcohol use in the 5 months preceding (baseline period) the introduction of new alcohol policies [full-time stationing of Police Auxiliary Liquor Inspectors (PALIs) and minimum unit price (MUP)] compared with 12 months (post-intervention) following. Secondary outcomes included measures of resource use [length of stay (LoS), need for mechanical ventilation] and mortality, stratified by site. Findings Overall, there was a 4.5% [95% confidence interval (CI) = 0.8-8.2%] absolute risk reduction between the time-periods (95% CI = 23.4 versus 18.9% for baseline and post-intervention, respectively, P = 0.01), predominantly due to a reduction in admissions associated with acute misuse (2.3%, 95% CI = -0.2 to 4.9% risk reduction, P = 0.06). There were regional differences, with a more marked relative risk reduction observed in Central Australia compared with the city of Darwin (27.0 versus 16.7% relative risk reduction, respectively). Conclusions Introduction of new alcohol harm minimization policies in the Northern Territory of Australia appears to have reduced the number of intensive care unit admissions associated with hazardous and harmful alcohol use. Strength of effect varies by geographical region and chronicity of hazardous and harmful alcohol use.

In this work, we present a computational investigation on the photoexcitation of indigo carmine (IC). Physical insights regarding IC photoexcitation and photolysis were obtained from a fundamental perspective through quantum chemistry computations. Density functional theory (DFT) was used to investigate the ground state while its time-dependent formalism (TD-DFT) was used for probing excited state properties, such as vertical excitation energies, generalized oscillator strengths (GOS), and structures. All the computations were undertaken using two different approaches: M06-2X/6-311+G(d,p) and CAM-B3LYP/6-311+G(d,p), in water. Results determined using both methods are in systematic agreement. For instance, the first singlet excited state was found at 2.28 eV (with GOS = 0.4730) and 2.19 eV (GOS = 0.4695) at the TD-DFT/CAM-B3LYP/6-311+G(d,p) and TD-DFT/M06-2X/6-311+G(d,p) levels of theory, respectively. Excellent agreement was observed between the computed and the corresponding experimental UV-Vis spectra. Moreover, results suggest IC undergoes photodecomposition through excited state chemical reaction rather than via a direct photolysis path. To the best of our knowledge, this work is the first to tackle the photoexcitation, and its potential connections to photodegradation, of IC from a fundamental chemical perspective, being presented with expectations to motivate further studies.

It was previously reported that Laplace transformed local CC2 (LCC2*) provided the best agreement (MAE = 0.145 eV) when comparing vertical excitation energies to experimental λmax for a benchmark set of 17 BODIPY/Aza-BODIPY molecules. However, these energies did not agree with values obtained from canonical CC2. Here we report LCC2* computations of vertical excitation energies on the same benchmark set of molecules using a newly implemented treatment of the ground state. Comparison with resolution-of-identity approximate coupled cluster to second-order (RI-CC2) results demonstrate that the new LCC2* results agree quantitatively. Furthermore, these values can easily be corrected empirically to also provide excellent agreement with the experiment. We show that the local algebraic diagrammatic construction to second-order (LADC(2)) method exhibits the same differences between implementations as seen for LCC2. The source of the difference is traced to an improved treatment of the ground state in the local methods, which decreases agreement with the experiment (as attributed to a fortuitous cancellation of errors) but significantly improves agreement with RI-CC2. While the absolute vertical excitation energies now show larger deviations, there remains a strong linear correlation between the LCC2* results and the experiment. For the 17 BODIPY/Aza-BODIPY molecules vertical excitation energies are determined using DLPNO-STEOM-CCSD and shown to have excellent agreement with experimental λmax (MAE = 0.145 eV), which is the best of all the single-reference methods. The vertical excitation energies are determined using LCC2*, empirically corrected LCC2*, and RI-CC2 for a series of eight large BODIPYs and Aza-BODIPYs.

This protocol has been optimized for the recombinant expression of a codon-optimized Bst-LF polymerase. The goal of this protocol was to eliminate the use of large volumes for dyalisis through the use of concentrators for buffer exchange before storage conditions. The plasmid encoding the codon-optimized Bst-LF enzyme used here can be found on reclone.org

About: This protocol has been optimized for recombinant expression of molony virus based reverse transcriptases (RT). The plasmid used contains a reverse transcriptase gene which is derived from Moloney Murine Leukemia Virus. The enzyme when expressed recombinantly can synthesizes a complementary DNA strand from single-stranded RNA, DNA, or an RNA:DNA hybrid. Enzyme Engineering: The enzyme contains point mutations to generate a highly processive, thermostable, and improved fidelity mutant reverse transcriptase. Details, incluiding the sequence of this enzyme are published and can be found in the references below and addgene link. The enzyme contains an active RNAse H domain and is highly thermostable. This MMLV construct contains the following mutations: D200N, L603W, T330P, L139P, E607K,D524G, E562Q, D583N and D653N. These appear to be the same set of mutations present in the Thermo Fisher Maxima H- RT, which is one of the best preforming RTs you can buy. The enzyme in our hands is extremely active. Moreover, while the MMLV RT is thermostable and will work up to 65°C it runs optimally at 42°C. The point muitations utilized here are currently filed under a provisional patent with Thermo Fisher Scientific. Commcercial use of this enzyme must go though Thermo Fisher Scientific. It is also possible to further engineer this enzyme with to increase thermostability and eliminate RNase H activity to generate an enzyme which closely mimicks Thermo Fisher Maxima H+ RT. Introducing mutations (D524G, E562Q, D583N and D653N) and/or (D524, D583, E562, H204, V223, T306, F309) are best suted eliminate RNase H activity completely, and it will increase the thermostability somewhat as well Comments: Reference 2 highlights several point mutations which can be introduced to eliminate Rnase H activity which may also enhance RT sensitivity. Thermo Product information brochure from 2013 suggest that this mutant or some combintation of other identified point mutations from reference 2 is Maxima RT, Maxima H-. The paper has also identified a few more useful point mutations which may further optimise MMLV-RT This expression protocol can also implemented to express other MMLV based reverse transcriptases or diversely related retroviral RTs, provided the genes are in an expresison construct with an N- terminal 6-10 His Tag and are expressed under a T7 promoter. The plasmid used can be found on reclone.org and addgene SkiBar H+ RT was synthesized as a gBlock from IDT and is codon optimized. Expressed in Rosetta DE3 his tag is on still but seems to work fine with it on. Tgatcc motif at MCS is a result of issues cloning in with BamHI. Had to use a compatible sticky end from BclI-HF Protein Properties: 79.9 kDa Isoelectric point (pI) : 7.77 Charge at pH 7.0: 9.52 Name: The name SkiBar H+ RT is an abbreviation of the first two first authors where the MMLV mutations used in the construct were originally discovered (Skirgaila & Baranauskas). References: Baranauskas, Aurimas Paliksa, Sigitas Alzbutas, Gediminas Vaitkevicius, Mindaugas Lubiene, Judita Letukiene, Virginija Burinskas, Sigitas Sasnauskas, Giedrius Skirgaila, Remigijus Generation and characterization of new highly thermostable and processive M-MuLV reverse transcriptase variants Protein Engineering, Design and Selection (2012) Skirgaila, Remigijus Pudzaitis, Vaidas Paliksa, Sigitas Vaitkevicius, Mindaugas Janulaitis, Arvydas Compartmentalization of destabilized enzyme-mRNA-ribosome complexes generated by ribosome display: A novel tool for the directed evolution of enzymes Protein Engineering, Design and Selection (2013)

This protocol has been optimized for recombinant expression of molony virus based reverse transcriptases (RT). The plasmid used contains a reverse transcriptase gene which is derived from Moloney Murine Leukemia Virus. The enzyme when expressed recombinantly can synthesizes a complementary DNA strand from single-stranded RNA, DNA, or an RNA:DNA hybrid. The enzyme contains point mutations to generate a highly processive, thermostable, and improved fidelity mutant reverse transcriptase. Details, incluiding the sequence of this enzyme are published and can be found here PMID: 22691702. The enzyme contains an active RNAse H domain and is highly thermostable. The point muitations utilised here are currently filed under a provisioal patent with Thermo Fisher Scientific. Commcercial use of this enzyme must go though Thermo Fisher Scientific. This expression protocol can also implemented to express other MMLV based reverse transcriptases or diversely related retroviral RTs, provided the genes are in an expresison construct with an N- terminal 6-10 His Tag and are expressed under a T7 promoter. The plasmid used can be found on reclone.org

Multi-photon absorption properties, particularly two-photon absorption (2PA), of fluorescent proteins (FPs) have made them attractive tools in deep-tissue clinical imaging. Although the diversity of photophysical properties for FPs is wide, there are some caveats predominant among the existing FP variants that need to be overcome, such as low quantum yields and small 2PA cross-sections. From a computational perspective, Salem et al. (2016) suggested the inclusion of non-canonical amino acids in the chromophore of the red fluorescent protein DsRed, through the replacement of the tyrosine amino acid. The 2PA properties of these new non-canonical chromophores (nCCs) were determined in vacuum, i.e., without taking into account the protein environment. However, in the computation of response properties, such as 2PA cross-sections, the environment plays an important role. To account for environment and protein–chromophore coupling effects, quantum mechanical/molecular mechanical (QM/MM) schemes can be useful. In this work, the polarizable embedding (PE) model is employed along with time-dependent density functional theory to describe the 2PA properties of a selected set of chromophores made from non-canonical amino acids as they are embedded in the DsRed protein matrix. The objective is to provide insights to determine whether or not the nCCs could be developed and, thus, generate a new class of FPs. Results from this investigation show that within the DsRed environment, the nCC 2PA cross-sections are diminished relative to their values in vacuum. However, further studies toward understanding the 2PA limit of these nCCs using different protein environments are needed.

In this work, we present a computational investigation on diquat, paraquat, and six dipyridyl isomers (2,2 ′ -dipyridyl, 2,3 ′ -dipyridyl, 2,4 ′ -dipyridyl, 3,3 ′ -dipyridyl, 3,4 ′ -dipyridyl, and 4,4 ′ -dipyridyl). Ground state properties such as equilibrium structures, relative energetics, transition states for cis–trans interconversion, and vibrational frequencies were determined for all the isomers at the MP2 level of theory with the cc-pVTZ basis set in the gas-phase; the MP2/cc-pVTZ and MP2/6-311+G(d,p) levels of theory in water were employed for diquat and paraquat. The trans structures are the most stable ones among the compounds that present such isomeric forms, with relative energies of 6.24 kcal/mol, 0.61 kcal/mol, and 0.12 kcal/mol lower than the cis counterparts in 2,2 ′ -dipyridyl, 2,3 ′ -dipyridyl, and 3,3 ′ -dipyridyl, respectively. The transition state lies at 7.65 kcal/mol above the trans form in the case of 2,2 ′ -dipyridyl, 3.68 kcal/mol for 2,3 ′ -dipyridyl, and 2.02 kcal/mol for 3,3 ′ -dipyridyl, indicating that the interconversion is feasible in the cases of 2,3 ′ -dipyridyl and 3,3 ′ -dipyridyl and unlikely to occur in 2,2 ′ -dipyridyl at room temperature. Vertical excitation energies and respective generalized oscillator strengths (GOS) were determined using time-dependent density functional theory (CAM-B3LYP/cc-pVTZ and PBE0/cc-pVTZ) and EOM-CCSD/cc-pVTZ. In terms of excitation (and independent of computational method), all the isomers except 4,4 ′ -dipyridyl, presented excited electronic states that are both bright (with GOS > 0.1) and energetically accessible at UV–vis wavelengths. Two bright states were found for diquat and paraquat in the UV region. Therefore, we expect that photoinduced degradation of both compounds can benefit from the utilization of techniques combining more than one source of radiation.

The Axion Resonant InterAction Detection Experiment (ARIADNE) is a collaborative effort to search for the QCD axion using nuclear magnetic resonance (NMR), where the axion acts as a mediator of spin-dependent forces between an unpolarized tungsten source mass and a sample of polarized helium-3 gas. Since the experiment involves precision measurement of a small magnetization, it relies on limiting ordinary magnetic noise with superconducting magnetic shielding. In addition to the shielding, proper characterization of the noise level from other sources is crucial. We investigate one such noise source in detail: the magnetic noise due to impurities and Johnson noise in the tungsten source mass.

Dysfunctional adipose tissue phenotype underpins type 2 diabetes mellitus (T2DM) development. The disruption of circadian rhythms contributes to T2DM development. We investigated the effects of high-energy diet and photoperiod length on visceral and subcutaneous adipose tissue phenotype. Psammomys obesus sand rats exposed to neutral (12 light:12 dark) or short (5 light:19 dark) photoperiod were fed a low- (LE) or high- (HE) energy diet. The HE diet and/or short photoperiod reduced subcutaneous expression of adipocyte differentiation/function markers C/ebp&alpha, Ppar&delta, Ppar&gamma, and Adipoq. Visceral Ppar&alpha, levels were elevated in the 5:19HE group, however, the HE diet and/or short photoperiod decreased visceral Ppar&gamma, and Adipoq expression. 5:19HE animals had elevated Ucp1 yet lower Pgc-1&alpha, levels. The HE diet increased visceral Tgf-&beta, 1, Ccl2 and Cd68 levels, suggestive of a pro-inflammatory state. Daily visceral rhythms of these genes were affected by a short photoperiod and/or HE diet. The 12:12HE, 5:19LE or 5:19HE animals had a higher proportion of larger adipocytes, indicating increased adipocyte hypertrophy. Collectively, the HE diet and/or shorter light exposure drives a dysfunctional adipose tissue phenotype. Daily rhythms are affected by a short photoperiod and HE diet in a site-specific manner. These findings provide mechanistic insight on the influence of disrupted circadian rhythms and HE diet on adipose tissue phenotype.

Non-invasive molecular imaging techniques are accruing more interest in the last decades. Several radiolabelling elements have been FDA-approved and are currently used to characterize tumors. In this study, the DNA intercalating agent doxorubicin was radiolabelled with 125I. Several parameters for the radiolabelling reaction were investigated and optimized. A maximum yield of 94 ± 0.3% was reached after reacting 20 μg of doxorubicin with 200 μg Chloramine-T at pH 5 for 30 min. The in vivo stability of 125I-doxorubicin is validated by the low propensity for thyroid uptake in mice. The preclinical T/NT ratio was approximately 6.4 at 30 min. Docking and molecular dynamics confirmed that the radiolabelling of doxorubicin did not affect (or slightly improved its binding to DNA). Overall, 125I-doxorubicin was demonstrated to be a promising non-invasive probe for solid tumor imaging.

Summary Lysophosphatidate acyltransferase (LPAAT) catalyses the second step of the Kennedy pathway for triacylglycerol (TAG) synthesis. In this study we expressed Trapaeolum majus LPAAT in Brassica napus (B. napus) cv 12075 to evaluate the effects on lipid synthesis and estimate the flux control coefficient for LPAAT.We estimated the flux control coefficient of LPAAT in a whole plant context by deriving a relationship between it and overall lipid accumulation, given that this process is a exponential.Increasing LPAAT activity resulted in greater TAG accumulation in seeds of between 25% and 29%; altered fatty acid distributions in seed lipids (particularly those of the Kennedy pathway); and a redistribution of label from 14C‐glycerol between phosphoglycerides.Greater LPAAT activity in seeds led to an increase in TAG content despite its low intrinsic flux control coefficient on account of the exponential nature of lipid accumulation that amplifies the effect of the small flux increment achieved by increasing its activity. We have also developed a novel application of metabolic control analysis likely to have broad application as it determines the in planta flux control that a single component has upon accumulation of storage products.

Fundamental coordination chemistry of Mo(VI) at its macroconcentrations in solvent extraction systems is of great importance for industrial processes that require the purification or recovery of large concentrations of Mo. The coordination of Mo(VI) in tri-n-butyl phosphate (TBP) from solutions of hydrochloric acid and up to 0.3 M Mo was investigated using UV, FTIR, and 31P NMR spectroscopies, as well as EXAFS. From these techniques we resolved near-neighbor atoms, speciation, structural information on the coordination environment, and thermodynamic parameters affiliated with the solvent extraction of Mo(VI) and HCl. The solvated extracted form of Mo(VI) as MoO2Cl2·2TBP was identified. High extraction yield of Mo at >5 M HCl concentration is driven by replacing HCl in the organic phase by Mo. The existence of additional organic Mo adducts is also discussed with the aid of density functional theory, however no evidence of dimeric or polymeric Mo species was found to be present in TBP.

We report a new method of crystal growth and synthesis based on liquid-liquid partitioning that allows for isolation and in-depth characterization of molybdenyl bis(formohydroxamate), Mo-FHA, molybdenyl bis(acetohydroxamate), Mo-AHA, and molybdenyl deferoxamine, Mo-DFO, for the first time. This novel approach affords shorter crystal growth time (hourly timeframe) without sacrificing crystal size or integrity when other methods of crystallization were unsuccessful. All three Mo complexes are characterized in solution via FTIR, NMR, UV–vis, and EXAFS spectroscopy. Mo-AHA and Mo-FHA structures are resolved by single crystal X-ray diffraction. Using the molybdenyl hydroxamate structural information, the speciation of Mo in a siderophore complex (Mo-DFO) is determined via complimentary spectroscopic methods and confirmed by DFT calculations. ESI-MS verifies that a complex of 1:1 molybdenum to deferoxamine is present in solution. Additionally, the Mo solution speciation in the precursor organic phase, MoO2(NO3)2HEH[EHP]2 (where HEH[EHP] is 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester), is characterized by FTIR and EXAFS spectroscopy as well as DFT calculations.

OBJECTIVE To examine the association between soluble tumor necrosis factor receptor 1 (sTNFR1) levels and kidney disease progression in Indigenous Australians at high risk of kidney disease. RESEARCH DESIGN AND METHODS This longitudinal observational study examined participants aged ≥18 years recruited from >20 sites across diabetes and/or kidney function strata. Baseline measures included sTNFR1, serum creatinine, urine albumin-to-creatinine ratio (uACR), HbA1c, C-reactive protein (CRP), waist-to-hip ratio, systolic blood pressure, and medical history. Linear regression was used to estimate annual change in estimated glomerular filtration rate (eGFR) for increasing sTNFR1, and Cox proportional hazards were used to estimate the hazard ratio (HR) and 95% CI for developing a combined renal outcome (first of a ≥30% decline in eGFR with a follow-up eGFR RESULTS Over a median of 3 years, participants with diabetes (n = 194) in the highest compared with the lowest quartile of sTNFR1 experienced significantly greater eGFR decline (−4.22 mL/min/1.73 m2/year [95% CI −7.06 to −1.38]; P = 0.004), independent of baseline age, sex, eGFR, and uACR. The adjusted HR (95% CI) for participants with diabetes per doubling of sTNFR1 for the combined renal outcome (n = 32) was 3.8 (1.1–12.8; P = 0.03). No association between sTNFR1 and either renal outcome was observed for those without diabetes (n = 259). CONCLUSIONS sTNFR1 is associated with greater kidney disease progression independent of albuminuria and eGFR in Indigenous Australians with diabetes. Further research is required to assess whether TNFR1 operates independently of other metabolic factors associated with kidney disease progression.

A well-defined Ir-allyl complex catalyzes the Z-selective cross-coupling of allyl carbonates with α-aryl diazo esters. The process overrides the large thermodynamic preference for E-products typically observed in metal-mediated coupling reactions to enable the synthesis of Z,E-dieneoates in good yield with selectivities consistently approaching or greater than 90 : 10. This transformation represents the first productive merger of Ir-carbene and Ir-allyl species, which are commonly encountered intermediates in allylation and cyclopropanation/E-H insertion catalysis. Potentially reactive functional groups (aryl halides, ketones, nitriles, olefins, amines) are tolerated owing to the mildness of reaction conditions. Kinetic analysis of the reaction suggests oxidative addition of the allyl carbonate to an Ir-species is rate-determining. Mechanistic studies uncovered a pathway for catalyst activation mediated by NEt3.

The complexation of HDEHP, HEH[EHP], T2EHDGA, and TODGA and mixtures thereof in n-dodecane with Nd(III), Pm(III), and Am(III), extracted from pH 3 aqueous media, were analyzed by distribution analysis, IR, UV–vis, and X-ray spectroscopies. Appreciable ternary complex formation is seen among HDEHP with DGA components and to a lesser extent with HEH[EHP]. Ternary complex formation constants were determined by absorption spectroscopy and slope analysis. The effect of the adduct formation on the process performance and on the Ln/An selectivity is discussed. It has been shown that the ternary complexes have the tendency to extract larger trivalent cations as Am and Nd over Eu, thus diminishing the overall Ln/Am selectivity of the process. Also, previously unreported extraction constants were derived for HEH[EHP] with Am and Pm as well as coordination information for Nd-HEH[EHP] and Nd-T2EHDGA complexes.

Previous research in our group showed that tellurophenes with pinacolboronate (BPin) units at the 2- and/or 5-positions displayed efficient phosphorescence in the solid state, both in the presence of oxygen and water. In this current study, we show that luminescence from a tellurophene is possible when various aryl-based substituents are present, thus greatly expanding the family of known (and potentially accessible) Te-based phosphors. Moreover, for the green phosphorescent perborylated tellurium heterocycle, 2,3,4,5-TeC4BPin4 (4BTe), oxygen-mediated quenching of phosphorescence is an important contributor to the lack of emission in solution (when exposed to air); thus this system displays aggregation-enhanced emission (AEE). These discoveries should facilitate the future design of color tunable tellurium-based luminogens.

A new process was developed to recover high specific activity (no carrier added)

Molybdenum-99 is the parent isotope of the most widely used isotope, technetium-99m, in all diagnostic nuclear medicine procedures. Due to proliferation concerns associated with the use of highly enriched uranium (HEU), the preferred method of fission-based Mo-99 production uses low enriched uranium (LEU) targets. Using LEU versus HEU for Mo-99 production produces ∼30 times more Pu-239, due to neutron capture on U-238 to produce Np-239, which ultimately decays to Pu-239 (t1/2 = 24,110 yr). Argonne National Laboratory is supporting a potential US Mo-99 producer in their efforts to produce Mo-99 from an LEU solution. In order to mitigate the generation of large volumes of greater-than-class-C (GTCC) low level waste (Pu-239 concentrations greater than 1 nCi/g), we have focused our efforts on the separation chemistry of Pu and Mo with a titania sorbent in sulfate media. Results from batch and column experiments show that temperature and acid wash concentration can be used to control Pu behavior on titania.

Determining the impact of lipid electrophile-mediated protein damage that occurs during oxidative stress requires a comprehensive analysis of electrophile targets adducted under pathophysiological conditions. Incorporation of ω-alkynyl linoleic acid into the phospholipids of macrophages prior to activation by Kdo2-lipid A, followed by protein extraction, click chemistry, and streptavidin affinity capture, enabled a systems-level survey of proteins adducted by lipid electrophiles generated endogenously during the inflammatory response. Results revealed a dramatic enrichment for membrane and mitochondrial proteins as targets for adduction. A marked decrease in adduction in the presence of MitoTEMPO demonstrated a primary role for mitochondrial superoxide in electrophile generation and indicated an important role for mitochondria as both a source and target of lipid electrophiles, a finding that has not been revealed by prior studies using exogenously provided electrophiles.

Several promising pathways exist for the production of 99Mo/99mTc using enriched 98Mo or 100Mo. Use of Mo targets requires a major change in current generator technology, and the necessity for an e...

While statins have formed the cornerstone of strategies for cardiovascular prevention, the residual risk related to low-density lipoprotein cholesterol (LDL-C) and other lipoprotein factors provides a landscape for development of new therapies. However, a number of lipid-modifying therapies have failed to reduce cardiovascular event rates in contemporary clinical trials of statin-treated patients. The factors considered in outcome measure selection for clinical trials of novel lipid-lowering therapies are reviewed. Evaluation of lipid-modifying drugs in clinical trials spans a spectrum from their effects on conventional circulating lipid parameters through to their impact on atherosclerotic plaque and ultimately clinical outcomes. The design of these trials has an important impact on the result and ultimate interpretation of these studies.

The effects of explicit hydrogen bonding with H2O on the resonance Raman spectra of uracil and thymine are examined computationally. The three bonding sites in uracil and thymine that form the lowest energy uracil-H2O and thymine-H2O complexes, as well as a more limited number of low-lying ones containing two waters, are considered. The ground state structures are optimized at the PBE0/aug-cc-pVTZ level of theory in H2O (C-PCM), and the gradients of the bright excited state ( S 1 ) are computed at the TD-CAM-B3LYP/aug-cc-pVTZ level of theory in H2O (C-PCM). As the resonance Raman spectrum is governed by the ground state normal modes and the excited state Cartesian gradient (within the Herzberg-Teller formalism), the differences between spectra of uracil- and thymine-(H2O)n, n = 1 or 2, are compared in terms of these two factors. Explicit hydrogen bonding to water is found to cause changes in both relative peak positions and intensities for the resonance Raman spectra of uracil and thymine when compared to the isolated molecules. The effect of hydrogen bonding is primarily on the ground state normal mode character, especially for the high frequency modes (>1600 cm−1), rather than on the excited state Cartesian gradients. Different hydrogen bonding sites are found to have different contributions to the resulting resonance Raman spectra, and inclusion of explicit hydrogen bonding on the carbonyl bond opposite to the ring nitrogen is necessary to obtain good agreement between the simulated and experimental resonance Raman spectra for uracil and thymine.

In this work, we present a computational study on the antioxidant potential of myricetin 3-O-α-L-rhamnopyranoside (Compound M3) and myricetin 4′-O-α-L-rhamnopyranoside (Compound M4′). Structural parameters, bond dissociation enthalpies (BDEs), ionization potentials (IPs), proton dissociation enthalpies (PDEs), proton affinities (PAs), and electron transfer enthalpies (ETEs), which are properties connected with different mechanisms related to antioxidant activity, were determined using density functional theory (DFT) with B3LYP, LC-ωPBE, M06-2X, and BMK functionals along with the 6-311G(d,p) and 6-311+G(d,p) basis sets in the gas phase, water, and pentylethanoate. The values obtained were compared with results previously available in the literature for myricetin (the parent molecule and a well-known antioxidant) and myricetin 3,4′-di-O-α-L-rhamnopyranoside (Compound M3,4′). As the BDEs are considerably lower than the IPs, the HAT mechanism is preferred over SET for the compounds M3 and M4′. The present study indicates Compound M3 as having its lowest bond dissociation enthalpy from the several different OH groups with similar value to the lowest for myricetin (74.72 kcal/mol versus 74.8 kcal/mol, respectively, at the B3LYP/6-311G(d,p) level of theory in the gas phase) and, thus, presenting antioxidant potential as good as its parent molecule. On the other hand, Compound M4′ presented 78.97 kcal/mol as the lowest BDE at the B3LYP/6-311G(d,p) level of theory in the gas phase, that is very close to the 78.34 kcal/mol computed using the same approach for Compound M3,4′. Therefore, the present investigation indicated Compound M4′ as being a slightly inferior antioxidant (with antioxidant potential comparable to Compound M3,4′) than Compound M3. In addition, the inclusion of the sugar moiety studied here in the position 4′-ArOH of myricetin seems to have a more marked impact (downward) on the antioxidant activity than the glycosylation in the position 3-ArOH.

Indigenous Australians experience a heavy burden of CKD. To address this burden, the eGFR Follow-Up Study recruited and followed an Indigenous Australian cohort from regions of Australia with the greatest ESRD burden. We sought to better understand factors contributing to the progression of kidney disease. Specific objectives were to assess rates of progression of eGFR in Indigenous Australians with and without CKD and identify factors associated with a decline in eGFR.This observational longitudinal study of Indigenous Australian adults was conducted in20 sites. The baseline cohort was recruited from community and primary care clinic sites across five strata of health, diabetes status, and kidney function. Participants were then invited to follow up at 2-4 years; if unavailable, vital status, progression to RRT, and serum creatinine were obtained from medical records. Primary outcomes were annual eGFR change and combined renal outcome (first of ≥30% eGFR decline with follow-up eGFR60 ml/min per 1.73 m(2), progression to RRT, or renal death).Participants (n=550) were followed for a median of 3.0 years. Baseline and follow-up eGFR (geometric mean [95% confidence interval], 83.9 (80.7 to 87.3) and 70.1 (65.9 to 74.5) ml/min per 1.73 m(2), respectively. Overall mean annual eGFR change was -3.1 (-3.6 to -2.5) ml/min per 1.73 m(2). Stratified by baseline eGFR (≥90, 60-89,60 ml/min per 1.73 m(2)), annual eGFR changes were -3.0 (-3.6 to -2.4), -1.9 (-3.3 to -0.5), and -5.0 (-6.5 to -3.6) ml/min per 1.73 m(2). Across baseline eGFR categories, annual eGFR decline was greatest among adults with baseline albumin-to-creatinine ratio (ACR)265 mg/g (30 mg/mmol). Baseline determinants of the combined renal outcome (experienced by 66 participants) were higher urine ACR, diabetes, lower measured GFR, and higher C-reactive protein.The observed eGFR decline was three times higher than described in nonindigenous populations. ACR was confirmed as a powerful predictor for eGFR decline across diverse geographic regions.

A series of 11 different boron-dipyrromethene (BODIPY) dimers is carefully examined by means of ab initio and Tamm-Dancoff approximated density functional theory methods. Vertical and 0-0 excitation energies along with the tetraradical character of these dimers are determined. Possible application of a series of linked dimers for photodynamic therapy (PDT) was investigated through computing their excitation energies, spin-orbit coupling matrix elements, and singlet-triplet energy gaps. Finally through a systematic investigation of a series of 36 different BODIPY and aza-BODIPY dimers, a new class of near-IR heavy atom free photosensitizers for PDT action is introduced.

The major components of the modified ALSEP process have been demonstrated on a modified 2-cm annular centrifugal contactor with an enhanced mixing zone using stable fission products and radiotracers. The results show that by decreasing the pH of the minor actinide stripping solution, using HEDTA instead of DTPA, and increasing contact time, the process is very effective in separating americium from the lanthanides and the fission products.

In this work, we present a computational study on the antioxidant potential of myricetin 3,4 $^{\prime }$ -di-O-α-L-rhamnopyranoside (Compound M). A density functional theory (DFT) approach with the B3LYP and LC-ωPBE functionals and with both the 6-311G(d,p) and 6-311+G(d,p) basis sets was used. The focus of the investigation was on the structural and energetic parameters including both bond dissociation enthalpies (BDEs) and ionization potentials (IPs), which provide information on the potential antioxidant activity. The properties computed were compared with BDEs and IPs available in the literature for myricetin, a compound well known for presenting antioxidant activity (and the parent molecule of the compound of interest in the present work). Myricetin 3,4 $^{\prime }$ -di-O-α-L-rhamnopyranoside presented the lowest BDE to be 79.13 kcal/mol (as determined using B3LYP/6-311G(d,p) in water) while myricetin has a quite similar value (within 3.4 kcal/mol). IPs computed in the gas phase [B3LYP/6-311G(d,p)] are 157.18 and 161.4 kcal/mol for myricetin 3,4 $^{\prime }$ -di-O-α-L-rhamnopyranoside and myricetin, respectively. As the values of BDEs are considerably lower than the ones probed for IPs (in the gas phase or in any given solvent environment), the hydrogen atom transfer mechanism is preferred over the single electron transfer mechanism. The BDEs obtained suggest that myricetin 3,4 $^{\prime }$ -di-O-α-L-rhamnopyranoside can present antioxidant potential as good as the parent molecule myricetin (a well-known antioxidant). Therefore, experimental tests on the antioxidant activity of Compound M are encouraged.

Nucleobases (adenine, cytosine, guanine, and uracil), the four molecules that forms RNA, have been found to be useful in probing in the human body when modified because they can emit light. Non-modified nucleobases do not exhibit emissive properties and cannot be used as probes. Some of the modifications include the substitution of nitrogen atoms with sulfur and selenium, and the resulting modified nucleobases give place to the so-called tz- and ts- RNA alphabets, respectively. Therefore, the aim of this project was to provide insights about the viability, from a computational perspective, of using the modified nucleobases as probes, evaluating the differences in thermochemical, structural and emissive properties of the modified nucleobases with respect to the non-modified ones. Nucleobases can coexist with other modified nucleobases or tautomers, molecules that differ due to the change in position of hydrogen atoms in a molecule’s structure and as a result have different physical and chemical properties. The thermochemical properties evaluation mainly consisted in the computation of the relative Gibbs Free Energy (G), which is related to the fraction F, an index of the relative population among tautomers. This was done using Gaussian 09 software by performing geometry analysis and frequency computations on each one of the tautomers. By comparing the equilibrium fractions, it was determined that in both cases, tz- and ts- guanine and cytosine exist principally in the form of one of their tautomers (Cytosine 2 and Guanine 2) as in the case of the non-modified cases. After confirming which tz- and ts- tautomers were the ones with the largest probable population, infrared (IR) and ultraviolet-visible (UV-vis) spectra were obtained. The IR spectra of selenium and sulfur tautomers of guanine and cytosine indicated that the tautomers had peaks at similar frequencies with respect to each other, however, the intensities varied, implying slight structural changes between the tautomers. On the other hand, the UV-vis spectra showed a change in peak positions between the tautomers with sulfur and selenium, suggesting that the change between sulfur and selenium has an effect on the spectra by shifting the peaks from the original molecules’ λmax values. Their relative population fractions show that only the canonical forms of the modified nucleobases exist in a larger extent than the rest of their tautomer forms. In addition, the features in their UV-vis and IR spectra allow these tautomers to be differentiated from each other.

A new method is presented here for digesting irradiated low-enriched uranium foil targets in alkaline carbonate media to recover 99Mo. This method consists of the electrolytic dissolution of uranium foil in a sodium bicarbonate solution, followed by the precipitation of carbonate, base-insoluble fission products, activation products, and actinides with calcium oxide; most of the molybdenum, technetium, and iodine remain in solution. An electrochemical dissolver and mixing vessel were designed, fabricated, and tested for the processing of a full-sized irradiated foil under ambient pressure and elevated temperature. Over 92% of the fission-induced 99Mo was recovered in a product solution that was compatible with an anion-exchange column for retaining molybdenum and iodine.

SummaryCirculating levels of the gut microbe-derived metabolite trimethylamine-N-oxide (TMAO) have recently been linked to cardiovascular disease (CVD) risk. Here, we performed transcriptional profiling in mouse models of altered reverse cholesterol transport (RCT) and serendipitously identified the TMAO-generating enzyme flavin monooxygenase 3 (FMO3) as a powerful modifier of cholesterol metabolism and RCT. Knockdown of FMO3 in cholesterol-fed mice alters biliary lipid secretion, blunts intestinal cholesterol absorption, and limits the production of hepatic oxysterols and cholesteryl esters. Furthermore, FMO3 knockdown stimulates basal and liver X receptor (LXR)-stimulated macrophage RCT, thereby improving cholesterol balance. Conversely, FMO3 knockdown exacerbates hepatic endoplasmic reticulum (ER) stress and inflammation in part by decreasing hepatic oxysterol levels and subsequent LXR activation. FMO3 is thus identified as a central integrator of hepatic cholesterol and triacylglycerol metabolism, inflammation, and ER stress. These studies suggest that the gut microbiota-driven TMA/FMO3/TMAO pathway is a key regulator of lipid metabolism and inflammation.