A diastereoselective 1,3-dipolar cycloaddition reaction between trifluoroethyl amine-derived isatin ketimines and chalcones was successfully achieved in the presence of DBU. A series of ...5′-CF3-substituted 3,2′-pyrrolidinyl spirooxindoles were efficiently synthesized with high yields and excellent diastereoselectivities (up to 89% yield, and >99 : 1 dr). The in vitro anticancer activities of these highly functionalized spiropyrrolidin-3,2′-oxindole derivatives were evaluated.
As the 2019 novel coronavirus disease (COVID-19) rapidly spread across China and to more than 70 countries, an increasing number of pregnant women were affected. The vertical transmission potential ...of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is of great concern to the obstetrics, neonatologists, and public health agencies. Though some studies indicated the risk of vertical transmission is low, few cases have been reported with comprehensive serial tests from multiple specimens. In this case, a female preterm infant was born to a mother with confirmed COVID-19. She presented with mild respiratory distress and received general management and a short period of nasal continuous positive airway pressure support. During her stay at the hospital, a series of SARS-CoV-2 nucleic test from her throat and anal swab, serum, bronchoalveolar lavage fluid, and urine were negative. The nucleic acid test from the mother's amniotic fluid, vaginal secretions, cord blood, placenta, serum, anal swab, and breast milk were also negative. The most comprehensively tested case reported to date confirmed that the vertical transmission of COVID is unlikely, but still, more evidence is needed.
Multicomponent surface droplets that consist of more than one compound are of great interest for fundamental studies of microwetting, evaporation, and dissolution behaviors, as well as for practical ...applications in high-throughput screening, microcompartmentalized chemical reactions, and microanalytics. In this work, we study the formation of multicomponent surface nanodroplets from heterogeneous nucleation and growth induced by the process of solvent exchange. In our experiments, as a solution of two oils in their good solvent was displaced by a poor solvent of the oils in the standard solvent exchange, binary droplets of oils were produced on an immersed substrate. The concentration of one oil was constant in the initial solution, whereas the other oil was increased gradually. We characterized the ratio of the two oils inside individual binary droplets by an infrared microspectrometer. Our results show that the ratio of two oils within binary nanodroplets could be varied from 0 to 100% by tuning the composition of the initial solution. However, the ratio of the two oils in the droplets did not simply correspond to that in the solution. Rather, we were able to correlate the ratio of the oils in the droplet to the oversaturation level of each oil based on the ternary phase diagram. We further demonstrate that the principle of the oversaturation level also governs the components in ternary nanodroplets formed by solvent exchange. The quantitative understanding in this work is valuable for the formation of multicomponent surface nanodroplets, which may be applied in nanoextraction, microcompartmentalized reactions, and surface functionalization.
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► The near-infrared QDs are synthesized in an aqueous solution. ► QDs-based biosensor exhibits visible-light induced cathodic photocurrent. ► The oxygen dependency of the photocurrent ...is verified. ► A photoelectrochemical strategy is established by coupling with enzymatic reaction. ► Photoelectrochemical sensor shows high upper detection limit, acceptable stability and accuracy.
A visible light induced photoelectrochemical biosensing platform based on oxygen-sensitive near-infrared quantum dots (NIR QDs) was developed for detection of glucose. The NIR QDs were synthesized in an aqueous solution, and characterized with scanning electron microscopy and X-ray photoelectron spectroscopy. The as-prepared NIR QDs were employed to construct oxygen-sensitive photoelectrochemical biosensor on a fluorine-doped tin oxide (FTO) electrode. The oxygen dependency of the photocurrent was investigated at as-prepared electrode, which demonstrated the signal of photocurrent is suppressed with the decreasing of oxygen. Coupling with the consumption of oxygen during enzymatic reaction, a photoelectrochemical strategy was proposed for the detection of substrate. Using glucose oxidase (GOx) as a model enzyme, that is, GOx was covalently attached to the surface of CdTe QDs, the resulting biosensor showed the sensitive response to glucose. Under the irradiation of visible light of a wavelength at 505nm, the proposed photoelectrochemical method could detect glucose ranging from 0.1mM to 11mM with a detection limit of 0.04mM. The photoelectrochemical biosensor showed a good performance with high upper detection limit, acceptable stability and accuracy, providing an alternative method for monitoring biomolecules and extending the application of near-infrared QDs.
Detection and quantification of the absolute DNA copy number alterations in tumor cells is challenging because the DNA specimen is extracted from a mixture of tumor and normal stromal cells. ...Estimates of tumor purity and ploidy are necessary to correctly infer copy number, and ploidy may itself be a prognostic factor in cancer progression. As deep sequencing of the exome or genome has become routine for characterization of tumor samples, in this work, we aim to develop a simple and robust algorithm to infer purity, ploidy and absolute copy numbers in whole numbers for tumor cells from sequencing data.
A simulation study shows that estimates have reasonable accuracy, and that the algorithm is robust against the presence of segmentation errors and subclonal populations. We validated our algorithm against a panel of cell lines with experimentally determined ploidy. We also compared our algorithm with the well-established single-nucleotide polymorphism array-based method called ABSOLUTE on three sets of tumors of different types. Our method had good performance on these four benchmark datasets for both purity and ploidy estimates, and may offer a simple solution to copy number alteration quantification for cancer sequencing projects.
The R package absCNseq is available from http://biostats.mcc.ucsd.edu/files/absCNseq_1.0.tar.gz CONTACT: kmesser@ucsd.edu Supplementary information: Supplementary data are available at Bioinformatics online.
Live cell imaging of protein‐specific glycoforms is important for the elucidation of glycosylation mechanisms and identification of disease states. The currently used metabolic oligosaccharide ...engineering (MOE) technology permits routinely global chemical remodeling (GCM) for carbohydrate site of interest, but can exert unnecessary whole‐cell scale perturbation and generate unpredictable metabolic efficiency issue. A localized chemical remodeling (LCM) strategy for efficient and reliable access to protein‐specific glycoform information is reported. The proof‐of‐concept protocol developed for MUC1‐specific terminal galactose/N‐acetylgalactosamine (Gal/GalNAc) combines affinity binding, off‐on switchable catalytic activity, and proximity catalysis to create a reactive handle for bioorthogonal labeling and imaging. Noteworthy assay features associated with LCM as compared with MOE include minimum target cell perturbation, short reaction timeframe, effectiveness as a molecular ruler, and quantitative analysis capability.
A localized chemical remodeling strategy for live cell imaging of protein‐specific glycoform is reported. Compared with the currently used global chemical remodeling method, namely metabolic oligosaccharide engineering, desired assay features of this approach include minimum target cell perturbation, short reaction timeframe, effectiveness as a molecular ruler, and quantitative analysis capability.
The gut microbiota of wild animals, influenced by various factors including diet, nutrition, gender, and age, plays a critical role in their health and disease status. This study focuses on raccoon ...dogs (
), a commonly found wild animal, and its gut microbiota composition in response to dietary shifts. The study aimed to compare the fecal bacterial communities and diversity of rescued raccoon dogs fed three different diet types (fish and amphibians, mixed protein with maize, and solely maize) using high-throughput sequencing. Results indicated that the dietary composition significantly influenced the gut microbiota, with notable differences in the abundance of several key phyla and genera. The study identified
as the dominant phylum in all diet groups, with notable variations in the relative abundances of
,
, and
. Notably, the group solely fed maize exhibited a significant increase in
, potentially linked to dietary fiber and lignin degradation. The genus-level analysis highlighted significant differences, with
and
responding to dietary shifts. The genus
in
can be identified as a marker for assessing the health of the gut and deserves further investigation. Gender-specific differences in the gut microbiota were observed, highlighting the influence of individual variation. Furthermore, the analysis of bacterial functions suggested a connection between diet and host metabolism, emphasizing the need for further research to understand the complex mechanisms underlying the relationship between dietary composition and gut microbiota in wild animals. These findings provide crucial insights into conservation and rescue efforts for wild animals.
Recently, programmable metamaterials or metasurfaces have been developed to dynamically edit electromagnetic waves for realizing different functions in the same platform. However, the proposed ...programmable metasurfaces can only control reflected or transmitted wavefronts in half‐space. Here, a “Janus” digital coding metasurface with the capabilities to program various electromagnetic functions in the reflected (with R‐codes) and transmitted (with T‐codes) waves simultaneously is presented. Three PIN diodes are employed to design the metaparticle, and the state of the PIN diodes can be switched to change the reflected and transmitted phases independently. Three schemes achieved by the proposed programmable metasurface are provided as illustrative examples, including anomalous deflections, beam focusing, and scattering reduction in the full space. As a proof‐of‐concept, a prototype composed of 10 × 20 metaparticles is fabricated and the measured results are in good agreement with the designs and numerical results, validating the full‐space modulations enabled by the programmable metasurface. It is expected that the new programmable metasurface can broaden the applications in stealth technologies, imaging systems, and the next generation of wireless communications.
A “Janus” coding programmable metasurface is proposed to edit the reflected and transmitted waves simultaneously in real‐time. Benefiting from the design of the separated current paths of diodes, the reflected and transmitted phases can be controlled independently in different polarizations. The proposed metasurface can implement various electromagnetic functions in the reflected (with R‐codes) and transmitted (with T‐codes) regions simultaneously.
Solution processed SnO2 film has been demonstrated to be an efficient electron transporting layer for perovskite solar cells owning to its outstanding opto-electric properties. At the same time, ...SnCl2, SnCl4 and their hydrates are the most widely used tin sources for depositing SnO2 films. Herein, we demonstrate that tin oxalate (SnC2O4) can function as an alternative tin source. A fast, clean and energy-saving method is proposed to fabricate SnO2 electron transporting layer at moderate temperature of 180 °C using a precursor solution of SnC2O4 dissolved in hydrogen peroxide. After optimization of the SnC2O4 concentrations, high quality SnO2 films can be obtained, which result in higher power conversion efficiency and better long-term device stability of the corresponding perovskite solar cells compared with the reference solar cells fabricated on commercial SnO2 films. Furthermore, the champion power conversion efficiency has been increased from 20.40% for the reference solar cell to 21.31% for the target solar cell.
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•SnC2O4 is used as an alternative tin source to fabricate SnO2 film.•A fast, clean, and energy-saving method using SnC2O4 and H2O2 is demonstrated.•PSCs with SnO2 film derived from SnC2O4 exhibit excellent performances.
The development of inertial confinement fusion (ICF) experiments necessitates the diagnostic instrument to have multiple frames with a high spatial and temporal resolution for the two-dimensional ...detection of the hot spot at the implosion end of the ICF. The existing sampling two-dimensional imaging technology in the world has superior performance; however, its subsequent development requires a streak tube with large lateral magnification. In this work, an electron beam separation device was designed and developed for the first time. The device can be used without changing the structure of the streak tube. It can be combined directly with the corresponding device and matched with a special control circuit. Based on the original transverse magnification, 1.77 times the secondary amplification can be achieved, which is conducive to expanding the recording range of the technology. The experimental results showed that the static spatial resolution of the streak tube after the inclusion of the device can still reach 10 lp/mm.
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