SNaPshot minisequencing to resolve mitochondrial macro‐haplogroups found in Africa

African mitochondrial DNA (mtDNA) haplogroups are divided into seven macro‐haplogroups (L0′1′2′3′4′5′6), while the rest of the world's lineages are classified as subgroups of macro‐haplogroups M, N and R. The most common approach to characterizing mtDNA variation is the sequencing of hypervariable segments I and II of the non‐coding control region of the molecule. Given the higher mutation rate within the control region compared with the coding regions of the molecule, recurrent mutations in the former can sometimes hide possible phylogenetic structure. The incorporation of haplogroup‐defining coding region mutations has helped in overcoming this limitation. By judiciously selecting 14 coding region SNPs and incorporating them into a multiplex minisequencing assay we were able to resolve mtDNA sequences from some sub‐Saharan African populations into ten macro‐haplogroups (L0–L6, M, N and R). We tested the efficacy of the panel by screening 699 individuals, consisting mostly of Khoe‐San, Bantu speakers and individuals with mixed ancestries (Coloreds) and found no inconsistencies compared with hypervariable segment sequencing results. The panel provided a fast and efficient means of classifying mtDNA into the ten mitochondrial macro‐haplogroups and provided a reliable screening to distinguish African from non‐African‐derived mtDNA lineages.     

N‐heterocyclic carbenes as organocatalysts in controlled/living ring‐opening polymerization of O‐carboxyanhydrides derived from l‐lactic acid and l‐mandelic acid

An organocatalytic approach to controlled/living ring‐opening polymerizations (ROPs) of O‐carboxyanhydrides (OCAs) using N‐heterocyclic carbenes (NHCs) as nucleophilic catalysts has been investigated. NHCs with different structures were used in order to compare the catalytic performances in the ROP of OCA of l ‐lactic acid. ¹H NMR, SEC, and MALDI‐TOF MS measurements of the products clearly indicated a controlled/living manner of the polymerization. The controlled/living nature was further confirmed by kinetic and chain extension experiments. Additionally, polylol initiators were used to produce α,ω‐dihydroxy telechelic, 3‐, and 4‐armed star‐shaped polymers. Moreover, star‐shaped diblock copolymer, bearing methyl and phenyl side groups, has been successfully synthesized with OCA/NHC system. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 . 52, 2306–2315     

Spectroelectrochemical Studies on Silicate Sol‐Gel Matrix‐supported Sub‐10 nm Prussian Blue Nanostructures‐based Electrochromic Device

In this study, spectroelectrochemical (SPE) studies to monitor the electrochromic properties of electrochemically synthesized sub‐10 nm sized Prussian blue (PB) nanostructures (NSs) are employed. At the beginning the dark blue coloured device, shifts reversibly between translucent and dark‐blue while applying an applied bias between +1 to ?1 V with an opposite polarization. Amine functionalized silicate sol‐gel matrix (SSG) is used as a solid support and stabilizer for electrodepositing highly uniform sub‐10 nm PB NSs. The SSG's film thickness is suitably optimized through suitable controlled experiments. It is found that the SPE behaviour of sub‐10 nm sized PB NSs, suitably followed a colour modulation of PB into Prussian white (PW) and vice‐versa. SPE studies are used to investigate the redox switching between the PB and PW and which are responsible for an electrochromic function of a fabricated electrochromic device (ECD). Fabricated ECD has demonstrated an optical modulation at 680 nm with the moderate coloration efficiency of 115.8 cm²/C. Present study validates the SPE feature of sub‐10 nm PB NSs as an active electrochromic nanomaterial and demonstrating the applicability of SPE technique to investigate the variety of electrochromic nanomaterials, with consequences in both spectral and electrochemically active nanomaterials for electrochromic device applications.     

Non‐Conjugated Polymer Dots with Crosslink‐Enhanced Emission in the Absence of Fluorophore Units

A new type of fluorescent material is presented, which is called non‐conjugated polymer dots (NCPDs). The NCPDs only possess sub‐fluorophores (which are groups such as C?O, C?N, N?O) instead of typical conjugated fluorophore groups, and thus these materials should not have strong photoluminescence (PL) in the usual sense. Nevertheless, the PL of these sub‐fluorophores can be enhanced by chemical crosslinking or physical immobilization of polymer chains, which is named the crosslink‐enhanced emission (CEE) effect. The significant advances achieved by us and other groups on both experimental and theoretical aspects are discussed, and the covalent‐bond CEE, rigidity‐aggregated CEE, or supramolecular CEE in NCPDs is elaborated. Moreover, synthetic strategies, unique optical properties, and the promise of NCPDs in bio‐related fields, such as bioimaging and drug delivery, are systematically discussed.     

Self‐Reported Changes in Sun‐Protection Behaviors at Different Latitudes in Australia

Sun exposure is the most important source of vitamin D, but is also a risk factor for skin cancer. This study investigated attitudes toward vitamin D, and changes in sun‐exposure behavior due to concern about adequate vitamin D. Participants (n = 1002) were recruited from four regions of Australia and completed self‐ and interviewer‐administered surveys. Chi‐square tests were used to assess associations between participants' latitude of residence, vitamin D‐related attitudes and changes in sun‐exposure behaviors during the last summer. Multivariate logistic regression analyses were used to model the association between attitudes and behaviors. Overall, people who worried about their vitamin D status were more likely to have altered sun protection and spent more time in the sun people not concerned about vitamin D. Concern about vitamin D was also more common with increasing latitude. Use of novel item response theory analysis highlighted the potential impact of self‐reported behavior change on skin cancer predisposition due concern to vitamin. This cross‐sectional study shows that the strongest determinants of self‐reported sun‐protection behavior changes due to concerns about vitamin D were attitudes and location, with people at higher latitudes worrying more.     

Generalized Dice's coefficient‐based multi‐block principal component analysis with Bayesian inference for plant‐wide process monitoring

Plant‐wide process monitoring is challenging because of the complex relationships among numerous variables in modern industrial processes. The multi‐block process monitoring method is an efficient approach applied to plant‐wide processes. However, dividing the original space into subspaces remains an open issue. The loading matrix generated by principal component analysis (PCA) describes the correlation between original variables and extracted components and reveals the internal relations within the plant‐wide process. Thus, a multi‐block PCA method that constructs principal component (PC) sub‐blocks according to the generalized Dice coefficient of the loading matrix is proposed. The PCs corresponding to similar loading vectors are divided within the same sub‐block. Thus, the PCs in the same sub‐block share similar variational behavior for certain faults. This behavior improves the sensitivity of process monitoring in the sub‐block. A monitoring statistic T² corresponding to each sub‐block is produced and is integrated into the final probability index based on Bayesian inference. A corresponding contribution plot is also developed to identify the root cause. The superiority of the proposed method is demonstrated by two case studies: a numerical example and the Tennessee Eastman benchmark. Comparisons with other PCA‐based methods are also provided. Copyright © 2014 John Wiley & Sons, Ltd.     

Cluster TOF‐SIMS imaging of human skin remains: analysis of a South‐Andean mummy sample

A skin sample from a South‐Andean mummy dating back from the XI^th century was analyzed using time‐of‐flight secondary ion mass spectrometry imaging using cluster primary ion beams (cluster‐TOF‐SIMS). For the first time on a mummy, skin dermis and epidermis could be chemically differentiated using mass spectrometry imaging. Differences in amino‐acid composition between keratin and collagen, the two major proteins of skin tissue, could indeed be exploited. A surprising lipid composition of hypodermis was also revealed and seems to result from fatty acids damage by bacteria. Using cluster‐TOF‐SIMS imaging skills, traces of bio‐mineralization could be identified at the micrometer scale, especially formation of calcium phosphate at the skin surface. Mineral deposits at the surface were characterized using both scanning electron microscopy (SEM) in combination with energy‐dispersive X‐ray spectroscopy and mass spectrometry imaging. The stratigraphy of such a sample was revealed for the first time using this technique. More precise molecular maps were also recorded at higher spatial resolution, below 1 µm. This was achieved using a non‐bunched mode of the primary ion source, while keeping intact the mass resolution thanks to a delayed extraction of the secondary ions. Details from biological structure as can be seen on SEM images are observable on chemical maps at this sub‐micrometer scale. Thus, this work illustrates the interesting possibilities of chemical imaging by cluster‐TOF‐SIMS concerning ancient biological tissues. Copyright © 2012 John Wiley & Sons, Ltd.     

Mono‐functionalized Heteroporphyrin Building Blocks and Unsymmetrical Covalent and Non‐covalent Porphyrin Dyads

Heteroporphyrins resulted from the replacement of one or two pyrrolic nitrogens with other hetero atoms such as O, S, Se and Te possess very interesting and distinct properties compared to tetrapyrrolic porphyrins. Specially, the singlet state energy levels can be fine tuned with suitable modification of porphyrin core by substituting pyrrolic “N” with other hetero atoms such as “O” and “S”. In this review, we describe our synthetic approaches for the synthesis of various mono‐functionalized heteroporphyrin building blocks and their use in the synthesis of several covalently and non‐covalently linked unsymmetrical porphyrin dyads containing two different porphyrin sub‐units. The photophysical studies are also described to show the possibility of singlet‐singlet energy transfer from one porphyrin sub‐unit to another in these unsymmetrical porphyrin dyads.     

Particle‐in‐a‐Frame Nanostructures with Interior Nanogaps

Designing plasmonic hollow colloids with small interior nanogaps would allow structural properties to be exploited that are normally linked to an ensemble of particles but within a single nanoparticle. Now, a synthetic approach for constructing a new class of frame nanostructures is presented. Fine control over the galvanic replacement reaction of Ag nanoprisms with Au precursors gave unprecedented Au particle‐in‐a‐frame nanostructures with well‐defined sub‐2 nm interior nanogaps. The prepared nanostructures exhibited superior performance in applications, such as plasmonic sensing and surface‐enhanced Raman scattering, over their solid nanostructure and nanoframe counterparts. This highlights the benefit of their interior hot spots, which can highly promote and maximize the electric field confinement within a single nanostructure.     

Organelle‐Targeted BODIPY Photocages: Visible‐Light‐Mediated Subcellular Photorelease

Photocaging facilitates non‐invasive and precise spatio‐temporal control over the release of biologically relevant small‐ and macro‐molecules using light. However, sub‐cellular organelles are dispersed in cells in a manner that renders selective light‐irradiation of a complete organelle impractical. Organelle‐specific photocages could provide a powerful method for releasing bioactive molecules in sub‐cellular locations. Herein, we report a general post‐synthetic method for the chemical functionalization and further conjugation of meso‐methyl BODIPY photocages and the synthesis of endoplasmic reticulum (ER)‐, lysosome‐, and mitochondria‐targeted derivatives. We also demonstrate that 2,4‐dinitrophenol, a mitochondrial uncoupler, and puromycin, a protein biosynthesis inhibitor, can be selectively photoreleased in mitochondria and ER, respectively, in live cells by using visible light. Additionally, photocaging is shown to lead to higher efficacy of the released molecules, probably owing to a localized and abrupt release.     

Synthesis of Sub‐2 nm Iron‐Doped NiSe2 Nanowires and Their Surface‐Confined Oxidation for Oxygen Evolution Catalysis

Ultrathin nanostructures are attractive for diverse applications owing to their unique properties compared to their bulk materials. Transition‐metal chalcogenides are promising electrocatalysts, yet it remains difficult to make ultrathin structures (sub‐2 nm), and the realization of their chemical doping is even more challenging. Herein we describe a soft‐template mediated colloidal synthesis of Fe‐doped NiSe₂ ultrathin nanowires (UNWs) with diameter down to 1.7 nm. The synergistic interplay between oleylamine and 1‐dodecanethiol is crucial to yield these UNWs. The in situ formed amorphous hydroxide layers that is confined to the surface of the ultrathin scaffolds enable efficient oxygen evolution electrocatalysis. The UNWs exhibit a very low overpotential of 268 mV at 10 mA cm^?2 in 0.1 m KOH, as well as remarkable long‐term stability, representing one of the most efficient noble‐metal‐free catalysts.     

Designing Sub‐2 nm Organosilica Nanohybrids for Far‐Field Super‐Resolution Imaging

Stimulated emission depletion (STED) microscopy enables ultrastructural imaging of biological samples with high spatiotemporal resolution. STED nanoprobes based on fluorescent organosilica nanohybrids featuring sub‐2 nm size and near‐unity quantum yield are presented. The spin–orbit coupling (SOC) of heavy‐atom‐rich organic fluorophores is mitigated through a silane‐molecule‐mediated condensation/dehalogenation process, resulting in bright fluorescent organosilica nanohybrids with multiple emitters in one hybrid nanodot. When harnessed as STED nanoprobes, these fluorescent nanohybrids show intense photoluminescence, high biocompatibility, and long‐term photostability. Taking advantage of the low‐power excitation (0.5 μW), prolonged singlet‐state lifetime, and negligible depletion‐induced re‐excitation, these STED nanohybrids present high depletion efficiency (>96 %), extremely low saturation intensity (0.54 mW, ca. 0.188 MW cm^?2), and ultra‐high lateral resolution (ca. λ_em/28).     

A Half‐Century with Solar Neutrinos (Nobel Lecture)

The Sun derives its energy from fusion reactions in which hydrogen is transformed into helium. Every time four protons are turned into a helium nucleus, two neutrinos are produced. These neutrinos take only two seconds to reach the surface of the Sun and another eight minutes or so to reach the Earth. Thus, neutrinos tell us what happened in the center of the Sun eight minutes ago. The Sun produces one‐third as many neutrinos as predicted by the standard solar model of particle physics. The author's pioneering work proved that nothing was wrong with the experiments or the theory; something was “wrong” with the neutrinos, in the sense that they behave in ways beyond the standard model.     

Long‐Lived Spin States for Low‐Field Hyperpolarized Gas MRI

Parahydrogen induced polarization was employed to prepare a relatively long‐lived correlated nuclear spin state between methylene and methyl protons in propane gas. Conventionally, such states are converted into a strong NMR signal enhancement by transferring the reaction product to a high magnetic field in an adiabatic longitudinal transport after dissociation engenders net alignment (ALTADENA) experiment. However, the relaxation time T₁ of ～0.6 s of the resulting hyperpolarized propane is too short for potential biomedical applications. The presented alternative approach employs low‐field MRI to preserve the initial correlated state with a much longer decay time T_LLSS=(4.7±0.5) s. While the direct detection at low‐magnetic fields (e.g. 0.0475 T) is challenging, we demonstrate here that spin‐lock induced crossing (SLIC) at this low magnetic field transforms the long‐lived correlated state into an observable nuclear magnetization suitable for MRI with sub‐millimeter and sub‐second spatial and temporal resolution, respectively. Propane is a non‐toxic gas, and therefore, these results potentially enable low‐cost high‐resolution high‐speed MRI of gases for functional imaging of lungs and other applications.     

Functionally integrated liquid crystalline photochromic triple block copolymer with locally light‐ and thermal‐controllable sub‐blocks

Photoorientation and reorientation processes induced by illumination of the samples with oppositely directed polarized light and by the thermal treatment were studied for the films of triblock copolymer pAzo₁₀‐b‐pPhM₈₀‐b‐pAzo₁₀ consisting of a nematic phenyl benzoate сentral sub‐block (PhM, DP = 80) with two terminal smectic azobenzene sub‐blocks (Azo, DP = 10). For amorphized films of triblock copolymer, illumination with polarized light (λ = 546 nm) is shown to be by orientation of only Azo‐containing groups, but upon following annealing of the film, PhM groups are adjusted to the orientation of Azo fragments. It was found, that the subsequent illumination of the block copolymer sample with oppositely directed polarized light changes the orientation of azobenzene groups, while the orientation of phenyl benzoate groups is remained unchanged. Thus, the cyclic illumination of the triblock copolymer samples by the linear polarized light and subsequent thermal treatment make it possible to control and fix orientation of azobenzene and phenyl benzoate groups located in different sub‐blocks in the desired and independent manner. The comparison of these results with the data on random p(Azo₇‐ran‐PhM₃₀) copolymer of the similar composition revealed, that in the random copolymer, both Azo and PhM mesogenic groups are involved in the orientational cooperative process regardless of films process treatment. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 1602–1611     

Cobalt‐Catalyzed Hydrogen‐Atom Transfer Induces Bicyclizations that Tolerate Electron‐Rich and Electron‐Deficient Intermediate Alkenes

A novel Co^II‐catalyzed polyene cyclization was developed that is uniquely effective when performed in hexafluoroisopropanol as the solvent. The process is presumably initiated by metal‐catalyzed hydrogen‐atom transfer (MHAT) to 1,1‐disubstituted or monosubstituted alkenes, and the reaction is remarkable for its tolerance of internal alkenes bearing either electron‐rich methyl or electron‐deficient nitrile substituents. Electron‐rich aromatic terminators are required in both cases. Terpenoid scaffolds with different substitution patterns are obtained with excellent diastereoselectivities, and the bioactive C20‐oxidized abietane diterpenoid carnosaldehyde was made to showcase the utility of the nitrile‐bearing products. Also provided are the results of several mechanistic experiments that suggest the process features an MHAT‐induced radical bicyclization with late‐stage oxidation to regenerate the aromatic terminator.     

An Extra‐Large‐Pore Zeolite with 24×8×8‐Ring Channels Using a Structure‐Directing Agent Derived from Traditional Chinese Medicine

Extra‐large‐pore zeolites have attracted much interest because of their important applications for processing larger molecules. Although great progress has been made in academic science and industry, it is challenging to synthesize these materials. A new extra‐large‐pore zeolite SYSU‐3 (Sun Yat‐sen University no. 3) has been synthesized by using a novel sophoridine derivative as an organic structure‐directing agent (OSDA). The framework structure was solved and refined using continuous rotation electron diffraction (cRED) data from nanosized crystals. SYSU‐3 exhibits a new zeolite framework topology, which has the first 24×8×8‐ring extra‐large‐pore system and a framework density (FD) as low as 11.4 T/1000 ų. The unique skeleton of the OSDA plays an essential role in the formation of the distinctive zeolite structure. This work provides a new perspective for developing new zeolitic materials by using alkaloids as cost‐effective OSDAs.     

Resonance Raman Spectral Imaging of Intracellular Uptake of β‐Carotene Loaded Poly(D,L‐lactide‐co‐glycolide) Nanoparticles

The use of nanoparticles for drug delivery has been drawing considerable attention in pharmaceutical research. With increasing diversity and potential of various carrier systems, it is important to study the impact of nanocarriers on sub‐cellular metabolic processes and organelles, since the delivery of a drug usually involves intra‐cellular internalization. Herein, we employ Raman microscopy as a non‐invasive method for cellular and sub‐cellular imaging, to monitor the uptake and translocation patterns of particles based on poly(D,L‐lactide‐co‐glycolide) over time. As the technique detects inherent signals from the molecules of interest, it does not rely on external labels or dyes, which is an advantage over fluorescence labeling. For this purpose, the particles were loaded with β‐carotene. The conjugated π‐system of the molecule has a large Raman scattering cross‐section and gives rise to resonance Raman effects, which can enhance the sensitivity by orders of magnitude. β‐Carotene as a provitamin is not soluble in water and is thus usually of low bioavailability, which is enhanced by encapsulation into the nanoparticles.     

Biodegradable Micelles Capable of Mannose‐Mediated Targeted Drug Delivery to Cancer Cells

A targeted micellar drug delivery system is developed from a biocompatible and biodegradable amphiphilic polyester, poly(Lac‐OCA)‐b‐(poly(Tyr(alkynyl)‐OCA)‐g‐mannose) (PLA‐b‐(PTA‐g‐mannose), that is synthesized via controlled ring‐opening polymerization of O‐carboxyanhydride (OCA) and highly efficient “Click” chemistry. Doxorubicin (DOX), a model lipophilic anticancer drug, can be effectively encapsulated into the micelles, and the mannose moiety allows active targeting of the micelles to cancer cells that specifically express mannose receptors, which thereafter enhances the anticancer efficiency of the drug. Comprised entirely of biodegradable and biocompatible polyesters, this micellar system demonstrates promising potentials for targeted drug delivery and cancer therapy.

     

The Origin of the Selectivity and Activity of Ruthenium‐Cluster Catalysts for Fuel‐Cell Feed‐Gas Purification: A Gas‐Phase Approach

Gas‐phase ruthenium clusters Ru_n⁺ (n=2–6) are employed as model systems to discover the origin of the outstanding performance of supported sub‐nanometer ruthenium particles in the catalytic CO methanation reaction with relevance to the hydrogen feed‐gas purification for advanced fuel‐cell applications. Using ion‐trap mass spectrometry in conjunction with first‐principles density functional theory calculations three fundamental properties of these clusters are identified which determine the selectivity and catalytic activity: high reactivity toward CO in contrast to inertness in the reaction with CO₂; promotion of cooperatively enhanced H₂ coadsorption and dissociation on pre‐formed ruthenium carbonyl clusters, that is, no CO poisoning occurs; and the presence of Ru‐atom sites with a low number of metal–metal bonds, which are particularly active for H₂ coadsorption and activation. Furthermore, comprehensive theoretical investigations provide mechanistic insight into the CO methanation reaction and discover a reaction route involving the formation of a formyl‐type intermediate.