Efficient and cost‐effective 3D cellular imaging by sub‐voxel‐resolving light‐sheet add‐on microscopy

Light‐sheet fluorescence microscopy (LSFM) allows volumetric live imaging at high‐speed and with low photo‐toxicity. Various LSFM modalities are commercially available, but their size and cost limit their access by the research community. A new method, termed sub‐voxel‐resolving (SVR) light‐sheet add‐on microscopy (SLAM), is presented to enable fast, resolution‐enhanced light‐sheet fluorescence imaging from a conventional wide‐field microscope. This method contains two components: a miniature add‐on device to regular wide‐field microscopes, which contains a horizontal laser light‐sheet illumination path to confine fluorophore excitation at the vicinity of the focal plane for optical sectioning; an off‐axis scanning strategy and a SVR algorithm that utilizes sub‐voxel spatial shifts to reconstruct the image volume that results in a twofold increase in resolution. SLAM method has been applied to observe the muscle activity change of crawling C. elegans, the heartbeat of developing zebrafish embryo, and the neural anatomy of cleared mouse brains, at high spatiotemporal resolution. It provides an efficient and cost‐effective solution to convert the vast number of in‐service microscopes for fast 3D live imaging with voxel‐super‐resolved capability.     

Synthesis,photoluminescence properties and theoretical insights on 1,3‐diphenyl‐5‐(9‐anthryl)‐2‐pyrazoline and ‐1H‐pyrazole

1,3‐Diphenyl‐5‐(9‐anthryl)‐2‐pyrazoline and 1,3‐diphenyl‐5‐(9‐anthryl)‐1H‐pyrazole with an anthryl chromophore were synthesized and characterized using ¹H NMR, ¹³C NMR, FT‐IR, mass spectrometry and elemental analysis. Their optical properties were characterized by UV–vis absorption and fluorescence spectroscopy. It was observed that the absorption and fluorescence spectra of the two compounds showed a red shift with respect to that of anthracene. Pyrazole exhibited high fluorescent quantum yields (Φ_f = 0.90 in toluene) while pyrazoline showed nearly no fluorescence in solution. The significant fluorescence divergence of the two similar compounds was investigated theoretically through density functional theory (DFT) calculations. The energetically lowest‐lying state S₁ in the pyrazoline exhibited both characteristics of locally excited and electron‐transfer states that resulted in the fluorescence quenching of anthryl chromophore whereas the S₁ state in the pyrazole corresponded to an optically allowed state that led to high fluorescence quantum yields in solutions. Copyright © 2012 John Wiley & Sons, Ltd.     

A note on pseudo‐observations and left‐truncation

Pseudo‐observations have been introduced as a way to perform regression analysis of a mean value parameter related to a right‐censored time‐to‐event outcome, such as the survival probability or the restricted mean survival time. Since the introduction of the approach there have been several extensions from the original setting. However, the proper definition and performance of pseudo‐observations under left‐truncation has not yet been addressed. Here, we look at two types of pseudo‐observations under right‐censoring and left‐truncation. We explored their performance in a simulation study and applied them to data on diabetes patients with left‐truncation.     

Gold‐silver and silver‐silver nanoparticle constructs based on DNA hybridization of thiol‐ and amino‐functionalized oligonucleotides

Metal nanoparticle constructs of particles of different sizes and materials were prepared, using DNA as connecting element. Therefore, gold and silver nanoparticles were functionalized with complementary DNA sequences that enabled a controlled coupling. The well‐established system based on thiolated DNA was thereby complemented with amino‐functionalized DNA. The realization of specific DNA‐DNA bonds due to hybridization was controlled by the ionic strength. The results demonstrate the potential of the combination of different particle sizes, composition as well as coupling chemistry in order to realize controlled conjugates of nanoparticles. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Proliferation‐ and migration‐enhancing effects of ginseng and ginsenoside Rg1 through IGF‐I‐ and FGF‐2‐signaling pathways on RSC96 Schwann cells

The aim of the present study is to evaluate the proliferation‐ and migration‐enhancing effects of ginseng and its component, ginsenoside (Rg1) on RSC96 Schwann cells. We investigated the molecular signaling pathways, which include: (1) survival signaling, IGFs‐IGFIR‐Akt‐Bcl2 and proliferative signaling, cell cycle factors and mitogen‐activated protein kinase (MAPK) pathways, (2) migrating and anti‐scar signaling, FGF‐2‐uPA‐MMPs.We treated RSC96 cells with different concentrations (100, 200, 300, 400, 500 µg ml^?1) of ginseng and its constituent, Rg1 (5, 10, 15, 20, 25 µg ml^?1). We observed a proliferative effect in a dose‐dependent manner by PCNA western blotting assay, MTT assay, and wound healing test. Furthermore, we also found in the results of western blotting assay, ginseng and Rg1 enhance protein expression of IGF‐I pathway regulators, cell cycle controlling proteins, and MAPK signaling pathways to promote the cell proliferation. In addition, ginseng and Rg1 also stimulated the FGF‐2‐uPA‐MMP 9 migrating pathway to enhance the migration of RSC96 Schwann cells. Using MAPK chemical inhibitors, U0126, SB203580, and SP600125, the proliferative effects of ginseng and Rg1 on RSC96 cells were identified to be MAPK signaling‐dependent. On the basis of the results, applying appropriate doses of ginseng and Rg1 with biomedical materials would be a potential approach for enhancing neuron regeneration. Copyright © 2009 John Wiley & Sons, Ltd.     

PI3K is involved in L‐selectin‐ and PSGL‐1‐mediated neutrophil rolling on E‐selectin via F‐actin redistribution and assembly

L‐selectin and P‐selectin glycoprotein ligand‐1 (PSGL‐1) are adhesion molecules that play critical roles in neutrophil rolling during inflammation and lymphocyte homing. On the other hand they also function as signaling receptors to induce cytoskeleton changes. The present study is to investigate the signaling kinases responsible for the F‐actin changes mediated by L‐selectin and PSGL‐1 during neutrophil rolling on E‐selectin. Western blot analysis demonstrated that PI3K activation, peaking within 5 min, was induced by ligation of L‐selectin and PSGL‐1 with E‐selectin, and that Vav1 (the pivotal downstream effector of PI3K signaling pathway involved in cytoskeleton regulation) was recruited to the membrane and tyrosine‐phosphorylated, depending on PI3K. Furthermore, the F‐actin redistribution and assembly mediated by ligation with E‐selectin were blocked by LY294002, a PI3K specific inhibitor. Additional experiments showed that PI3K activity was involved in neutrophil rolling on E‐selectin. However, Syk/Zap70, the well‐known upstream kinase of PI3K, was not involved in this event. These data suggest that PI3K is required for the F‐actin‐based cytoskeleton changes during neutrophil rolling on E‐selectin, which may consequently regulate the rolling event. J. Cell. Biochem. 110: 910–919, 2010. © 2010 Wiley‐Liss, Inc.     

Short‐ and long‐term effects on mAb‐producing CHO cell lines after cryopreservation

Cryopreservation provides the foundation for research, development, and manufacturing operations in the CHO‐based biopharmaceutical industry. Despite its criticality, studies are lacking that explicitly demonstrate that the routine cell banking process and the potential stress and damage during cryopreservation and recovery from thaw have no lasting detrimental effects on CHO cells. Statistics are also scarce on the decline of cell‐specific productivity (Q_p) over time for recombinant CHO cells developed using the glutamine synthetase (GS)‐based methionine sulfoximine (MSX) selection system. To address these gaps, we evaluated the impact of freeze‐thaw on 24 recombinant CHO cell lines (generated by the GS/MSX selection system) using a series of production culture assays. Across the panel of cell lines expressing one of three monoclonal antibodies (mAbs), freeze‐thaw did not result in any significant impact beyond the initial post‐thaw passages. Production cultures sourced from cryopreserved cells and their non‐cryopreserved counterparts yielded similar performance (growth, viability, and productivity), product quality (size, charge, and glycosylation distributions), and flow cytometric profiles (intracellular mAb expression). However, many production cultures yielded lower Q_p at increased cell age: 17 of the 24 cell lines displayed ≥20% Q_p decline after ～2–3 months of passaging, irrespective of whether the cells were previously cryopreserved. The frequency of Q_p decline underscores the continued need for understanding the underlying mechanisms and for careful clone selection. Because our experiments were designed to decouple the effects of cryopreservation from those of cell age, we could conclusively rule out freeze‐thaw as a cause for Q_p decline. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 34:463–477, 2018     

Some Aspects of Continuity and Change Among Anthropologists in Australia or‘He‐Who‐Eats‐From‐One‐Dish‐With‐Us‐With‐One‐Spoon’

Since the future of anthropology in Australia is clouded, the address takes a look at where it has been coming from. Rather than a distinctive regional school, the discipline in Australia has been part of anthropology in the UK and the USA. In common with anthropology elsewhere, it lacks a distinctive theoretical stance, but draws on the theory current in the other social sciences. Recognising that what makes anthropology ‘special’ is the field work experience, the address reflects on the history and nature of this practice.     

VCD studies on cyclic peptides assembled from L‐α‐amino acids and a trans‐2‐aminocyclopentane‐ or trans‐2‐aminocyclohexane carboxylic acid

The increasing interest in peptidomimetics of biological relevance prompted us to synthesize a series of cyclic peptides comprising trans‐2‐aminocyclohexane carboxylic acid (Achc) or trans‐2‐aminocyclopentane carboxylic acid (Acpc). NMR experiments in combination with MD calculations were performed to investigate the three‐dimensional structure of the cyclic peptides. These data were compared to the conformational information obtained by electronic circular dichroism (ECD) and vibrational circular dichroism (VCD) spectroscopy. Experimental VCD spectra were compared to theoretical VCD spectra computed quantum chemically at B3LYP/6‐31G(d) density functional theory (DFT) level. The good agreement between the structural features derived from the VCD spectra and the NMR‐based structures underlines the applicability of VCD in studying the conformation of small cyclic peptides. Copyright © 2010 European Peptide Society and John Wiley & Sons, Ltd.     

Norepinephrine‐ and Epinephrine‐deficient Mice Gain Weight Normally on a High‐fat Diet

Objective: Signaling through adrenergic receptors (ARs) by norepinephrine (NE) and epinephrine (Epi) regulates weight gain when mice are fed a high‐fat diet (HFD) by controlling diet‐induced thermogenesis. Thus, one would predict that mice unable to make NE/Epi because of inactivation of the dopamine β‐hydroxylase gene (Dbh‐null mice) would have a propensity to become obese. We characterized the response of Dbh‐null and control mice to a HFD. Research Methods and Procedures: Dbh‐null and control mice were fed an HFD or a regular diet (RD) for 2 months. Body weight, adiposity, muscle triglyceride levels, and adipocyte size were measured, as were circulating leptin, adiponectin, triglyceride, glucose, and insulin levels. A glucose tolerance test was also preformed. Results: Dbh‐null mice gain weight normally on an HFD and have the same adiposity. Their serum triglyceride and leptin levels are normal, but adipocytes are ～30% smaller than controls. Dbh‐null mice maintain low blood glucose levels and glucose tolerance when exposed to the HFD in contrast to controls. Discussion: Complete lack of NE/Epi does not predispose to obesity. Because mice lacking all three βARs become obese on an HFD, an imbalance of signaling through α‐ and βARs seems to be responsible for obesity. Surprisingly, Dbh‐null mice maintain glucose tolerance.     

Effects of corticosterone and 2,3,7,8‐tetrachloro‐ dibenzo‐p‐dioxin on epididymal antioxidant system in adult rats

2,3,7,8‐Tetrachlorodibenzo‐p‐dioxin (TCDD), an endocrine disruptor, causes epididymal toxicity by inducing oxidative stress. Glucocorticoids have been found to influence TCDD action in vitro and in vivo. The present experiments were set up to analyze the effects of TCDD on rat epididymal antioxidant system under the influence of increased corticosterone level. Adult male Wistar/NIN rats (70–80 days old) numbering 24 (six per group) were used in the study. Corticosterone (3 mg/kg body weight per day) or TCDD (100 ng/kg body weight per day) were administered or coadministered to rats for 15 days. Treatment with corticosterone or TCDD decreased the levels of serum testosterone significantly. In caput, corpus, and cauda fractions, administration of corticosterone or TCDD increased the levels of lipid peroxidation and hydrogen peroxide and decreased the activities of superoxide dismutase and catalase significantly. Coadministration of corticosterone and TCDD to rats decreased the levels of serum testosterone significantly as compared with rats treated with TCDD alone. In caput, corpus, and cauda fractions, the levels of lipid peroxidation and hydrogen peroxide were increased and activities of superoxide dismutase and catalase were decreased significantly as compared with rats treated with TCDD alone. Stress, characterized by increased glucocorticoid levels and activity, may enhance TCDD‐induced epididymal toxicity. © 2010 Wiley Periodicals, Inc. J Biochem Mol Toxicol 24:242–249, 2010; View this article online at wileyonlinelibrary.com . DOI 10.1002/jbt.20332     

All‐Solid‐State On‐Chip Supercapacitors Based on Free‐Standing 4H‐SiC Nanowire Arrays

All‐solid‐state on‐chip SiC supercapacitors (SCs) based on free‐standing SiC nanowire arrays (NWAs) are reported. In comparison to the widely used technique based on the interdigitated fingers, the present strategy can be much more facile for constructing on‐chip SCs devices, which is directly sandwiched with a solid electrolyte layer between two pieces of SiC NWAs film without any substrate. The mass loading of active materials of on‐chip SiC SCs can be up to ≈5.6 mg cm^?2, and the total device thickness is limited in ≈40 µm. The specific area energy and power densities of the SCs device reach 5.24 µWh cm^?2 and 11.2 mW cm^?2, and their specific volume energy and power densities run up to 1.31 mWh cm^–3 and 2.8 W cm^?3, respectively, which are two orders of magnitude higher than those of state‐of‐the‐art SiC‐based SCs, and also much higher than those of other solid‐state carbon‐based SCs ever reported. Furthermore, such on‐chip SCs exhibit superior rate capability and robust stability with over 94% capacitance retention after 10 000 cycles at a scan rate of 100 mV s^?1, representing their high performance in all merits.     

Inside Cover: Efficient and cost‐effective 3D cellular imaging by sub‐voxel‐resolving light‐sheet add‐on microscopy

A type of compact and cost‐effective light‐sheet imaging device, termed sub‐voxel‐resolving light‐sheet add‐on module (SLAM), is developed to cooperate with conventional 2D epifluorescence microscope, allowing high‐contrast, resolution‐improved 3D imaging of various biological samples at high throughput. Further details can be found in the article by Fang Zhao, Yicong Yang, Yi Li, et al. ( e201960243 ).

     

Synthesis of enantiomers of exo‐2‐norbornyl‐N‐n‐butylcarbamate and endo‐2‐norbornyl‐N‐n‐butylcarbamate for stereoselective inhibition of acetylcholinesterase

The acetylcholinesterase inhibition by enantiomers of exo‐ and endo‐2‐norbornyl‐N‐n‐butylcarbamates shows high stereoselelectivity. For the acetylcholinesterase inhibitions by (R)‐(+)‐ and (S)‐(?)‐exo‐2‐norbornyl‐N‐n‐butylcarbamates, the R‐enantiomer is more potent than the S‐enantiomer. But, for the acetylcholinesterase inhibitions by (R)‐(+)‐ and (S)‐(?)‐endo‐2‐norbornyl‐N‐n‐butylcarbamates, the S‐enantiomer is more potent than the R‐enantiomer. Optically pure (R)‐(+)‐exo‐, (S)‐(?)‐exo‐, (R)‐(+)‐endo‐, and (S)‐(?)‐endo‐2‐norbornyl‐N‐n‐butylcarbamates are synthesized from condensations of optically pure (R)‐(+)‐exo‐, (S)‐(?)‐exo‐, (R)‐(+)‐endo‐, and (S)‐(?)‐endo‐2‐norborneols with n‐butyl isocyanate, respectively. Optically pure norborneols are obtained from kinetic resolutions of their racemic esters by lipase catalysis in organic solvent. Chirality 2010. © 2009 Wiley‐Liss, Inc.     

ITO‐Free,Small‐Molecule Organic Solar Cells on Spray‐Coated Copper‐Nanowire‐Based Transparent Electrodes

The great potential of solution‐processed metal nanowire networks utilized as a transparent electrode has attracted much attention in the last years. Typically, silver nanowires are applied, although their replacement by more abundant and cheaper materials is of interest. Here, a hydrazine‐free synthesis route for high aspect ratio copper nanowires is used to prepare conductive networks showing an enhanced electrode performance. The network deposition is done with a scalable spray‐coating process on glass and on polymer foils. By a pressing or an annealing step, highly conductive transparent electrodes are obtained, and they reveal transmittance‐resistance values similar to indium tin oxide (ITO) and networks made of silver nanowires. The application potential of the copper nanowire electrodes is demonstrated by integrating them into an evaporated small‐molecule organic solar cell with 3% efficiency.