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Microbiomes exert significant influence on our planet's ecology. Elucidating the identities of individual microbes within these communities and how they interact is a vital research imperative. Using traditional plating and culturing methods, it is impractical to assess even a small fraction of the interactions that exist within microbial communities. To address this technology gap, we integrated gel microdroplet technology with microfluidics to generate millions of microdroplet cultures (MDs) that sequester individual cells for phenotyping MDs, facilitating rapid analysis and viable recovery using flow cytometry. Herein, we describe a validated high-throughput phenotyping pipeline that elucidates cell-to-cell interactions for millions of combinations of microorganisms. Through iterative co-culturing of an algae and a pool of environmentally sourced microbes, we successfully isolated bacteria that improved algal growth.

Abstract

Zeolite imidazole frameworks (ZIF-8) are a group of metal–organic frameworks (MOFs) that harbor application potential due to their unique high porosity and other physicochemical properties. However, the small cavities, unstable dispersion, and the lack of surface functional groups hinder the practical application of ZIF-8. In this study, we aimed to develop a ZIF-8-based multifaceted platform with hollow structure and abundant functional groups via a simple one-pot method. We synthesized the ZIF-8 with thiol functionalization (ZSH), while 2-mercaptoimidazole was served as both etching agent and functional counterpart. The hollow morphology and the thiol-groups modification were validated by scanning electron microscopy, transmission electron microscopy with energy-disperse X-ray mapping and X-ray photoelectron spectroscopy. The interparticle structure was estimated by Brunauer–Emmmett–Teller and ultraviolet–visible spectroscopy. The hollow architecture, colloidal stable, and thiol-abundant surface endow ZSHs exploiting the antioxidant and anti-inflammatory ability than pristine ZIF-8 toward a broad scale of morphological change with high functionalization degree. Moreover, ZSHs can specifically encapsulate gold nanoparticles in large quantities for further applications. Finally, ZSHs possess good biocompatibility in human cells and in vivozebrafish model and could potentially protect human cells against oxidative stress. This concept valuably elucidated the new era for functionalized ZIF-8 to apply as the next generation of multifunctional biomaterials.

End-pumped by a continuous-wave 976 nm diode laser, efficient 1522 nm laser operation was demonstrated in an Er:Yb:GdAl_3(BO_3)_4 crystal when a sapphire crystal was used as a heat diffuser. A continuous-wave 1522 nm laser with a maximum output power of 750 mW and slope efficiency of 36% was realized at an absorbed pump power of 4.1 W. The pulse performances of an acousto-optic Q-switched laser with various repetition frequencies were investigated in detail. In a repetition frequency range of 1–10 kHz, 1522 nm pulse lasers with a slope efficiency of about 10%, peak output power at the kilowatt level, and width of about 50 ns were first obtained in an Er:Yb:GdAl_3(BO_3)_4 crystal pumped by a continuous-wave diode laser. The results indicate that the crystal is a promising gain medium for an actively Q-switched 1.5 μm laser.

We present our recent spectrophotometric results of the infrared luminous Seyfert 2 galaxy NGC 7679. We find compelling evidence for the presence of a recent nuclear starburst, revealed by the observations of a) the spectral features of high order Balmer absorption lines, b) the weak equivalent widths for CaIIK λ3933, CN λ4200, G-band λ4300 and MgIb λ5173, and c) the suggested UV stellar wind resonance lines (N V λ1240, Si IV λ1400 and C IV λ1550) in the IUE spectrum. Using the simple stellar population synthesis model, we find that in the nuclear 2" $\times$2" region, the contributions from the old, intermediate and young components are 21.7% , 42.9% and 35.4% , respectively. These nuclear starburst activities might have been triggered by the close encounter with NGC 7682, as suggested by recent numerical simulations.

The cryostat in the China Fusion Engineering Testing Reactor (CFETR) provides vacuum and low temperature operating conditions for the superconducting magnet system. A high pressure in the cryostat can increase the Rayleigh number (Ra) and cause the natural convection within the continuous hypothesis. A three-dimensional model, using incompressible ideal gas model and realizable k-ε model, is built to simulate the natural convection between the superconducting magnet system and the thermal shield within the temperature range of 4.5-80 K. The distributions of velocity field and heat flux on different surfaces of superconducting magnet system are obtained under different Rayleigh number conditions. The results show that the areas with large natural convection velocity mainly locate near the Central Solenoid (CS) coils and at the bottom of vacuum chamber. When the Rayleigh number ranges from 104to 1010, the maximum velocity of helium gas decreases, while the heat flux on walls of superconducting magnets increases rapidly, and the heat flux on walls of PF-1, CS and TF coils is more affected by pressure, which needs to be considered in designing the safety system.

We present a theoretical study on the nonlocal optical effects on the Goos–Hänchen (GH) shift of reflected light from a composite material of metallic nanoparticles (MNPs). Using different nonlocal effective medium models, it is observed that such effects can be significant for small MNP of sizes down to a few nanometers. For small metallic volume fractions, the composite behaves like dielectric and the nonlocal effects lead to significant different Brewster angles, at which large negative GH shifts take place. For larger volume fractions or shorter wavelengths, the composite behaves more like metals and the nonlocal effects also lead to different Brewster angles but at values close to grazing incidence. These results will have significant implications in the application of different effective medium models for the characterization of these nanometallic composites when the MNPs are down to a few nanometers in size.

Er:NaY(WO_4)_2 and Er:Yb:Ce:NaY(WO_4)_2 crystals were grown by the Czochralski method. Er:Yb:NaY(WO_4)_2, Er:Ce:NaY(WO_4)_2, and Yb:NaY(WO_4)_2 crystal powders were synthesized by means of the solid-state reaction. The spectroscopic properties of the crystals were investigated, including the absorption and fluorescence spectra and fluorescence decay. The energy transfer efficiency from Yb^3+ to Er^3+ in Er:Yb:NaY(WO_4)_2 and Er:Yb:Ce:NaY(WO_4)_2 was calculated and analyzed. End-pumped by a diode laser at 970 nm in a hemispherical cavity, a 1.84 W quasi-continuous-wave laser around 1.55 μm with a slope efficiency of 17% and an absorbed pump threshold of 1.60 W was achieved in a 1.04 mm thick c-cut Er:Yb:Ce:NaY(WO_4)_2 crystal. The results show that the Er:Yb:Ce:NaY(WO_4)_2 crystal with high Ce^3+ doping is a candidate for gain medium of low threshold 1.55 μm laser.

To compare the effects of losartan and atenolol on plasma fibrinolytic parameters and von Willebrand factor (vWF), Chinese subjects with mild-to-moderate hypertension were randomized to receive losartan (50 mg/day; n= 30) or atenolol (50 mg/day; n= 30) for 8 weeks. If target blood pressure (< 140/90 mmHg) was not achieved at week 4, hydrochlorothiazide (12.5 mg/day) was also administered. Plasma levels of tissue plasminogen activator (tPA), plasminogen activator inhibitor-1 (PAI-1) and vWF were determined at baseline and after treatment. Between-group baseline characteristics and blood pressure decrease were comparable. Losartan significantly reduced plasma PAI-1 and vWF and PAI-1/tPA ratio. Atenolol significantly increased plasma tPA, but PAI-1, vWF and PAI-1/tPA ratio were unchanged. In conclusion, losartan, but not atenolol improved the fibrinolytic system and reduced plasma vWF levels in Chinese hypertensives.

The forest floor represents an important compartment for the accumulation of heavy metals in forest soils. To study the mobility of Pb species and their linkage to C cycling in the forest floor, we investigated concentrations of trimethyllead (C3H9Pb+) and total Pb (Pbtotal) in throughfall and forest floor percolates during 14 snow‐free wk. For our study, we used a long‐term field experiment with increased input of throughfall and litterfall at a Norway spruce [Picea abies(L.) H. Karst.] site. The concentrations of trimethyllead were highest in throughfall (106 pg Pb L−1) and decreased with depth of the forest floor. Strong correlations between trimethyllead concentrations in throughfall and forest floor percolates suggested that trimethyllead in forest floor percolates originates largely from throughfall. The partition coefficients of trimethyllead and Pbtotal, estimated as ratios of concentrations in percolates to those in forest floors, ranged from 54 to 560 and 870 to 26,400 L kg−1, respectively, indicating that the mobility of trimethyllead was greater than PbtotalThe Pbtotalconcentrations were low in throughfall and often the highest in Oa horizon percolates (15.2−57.5 μg L−1). They decreased in Oi horizon percolates after increased throughfall addition. Increased litterfall resulted in increased concentrations of Pbtotalin forest floor percolates. Concurrently, dissolved organic C increased. The tight coupling of Pbtotalto dissolved organic C was also indicated by correlations (r ≥ 0.48) that were stronger than those between Pbtotaland pH (r ≤ −0.22). We concluded that the mobilization of Pbtotalfrom the large pool in forest floor horizons is strongly linked to the release of dissolved organic matter. Conversely, the mobility of trimethyllead is regulated by throughfall input and not by dissolved organic C.

AbstractThis paper describes the design, implementation and evaluation of Mykil, a new key management system for supporting secure group multicast. Mykil was developed on a combination of group-based hierarchy and key-based hierarchy systems for secure group key management. The advantages of Mykil include a fast and efficient rekeying operation for large group sizes, continuous availability of the key management service in a disconnected network environment, an ability to map group structure to the underlying network infrastructure, and support for user mobility and smaller, hand-held devices. A prototype of Mykil has been implemented. The paper describes this implementation and reports on the performance measured.

Experiments were conducted to investigate the status of DIMBOA (2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one) and phenolic acids in leaves of some transgenic Bt corn hybrids. Comparison between Bt corn hybrids and their corresponding non-transgenic near-isogenic lines suggested that the introduction of the Bt gene has adverse effects on the biosynthesis and accumulation of DIMBOA and some phenolic acids, such as ferulic acid, in the corn plants. Under conditions of either water or nitrogen stress, the accumulation of DIMBOA in the leaves of the Bt corns could be enhanced. The results of this study suggest that caution must be taken when considering the introduction of Bt corns into China because Bt corns may have a weaker capacity, relative to traditional Chinese corn hybrids, to synthesise DIMBOA and some forms of phenolic acids in the leaves and, therefore, reduce the plant's resistance to pathogens, diseases, and pests other than the targetted corn borer.

The general large-scale synthesis of a family of single-crystalline transition metal tungstate nanorods/nanowires is easily realized by a hydrothermal crystallization technique under mild conditions using cheap and simple inorganic salts as precursors. Uniform tungstate nanorods/nanowires such as MWO4 (M = Zn, Mn, Fe), Bi2WO6, Ag2WO4, and Ag2W2O7 with diameters of 20–40 nm, lengths of up to micrometers, and controlled aspect ratios can be readily obtained by hydrothermal transformation and recrystallization of amorphous particulates. This novel and efficient pathway toward various kinds of related low-dimensional tungstate nanocrystals under mild conditions could open new opportunities for further investigating the novel properties of tungstate materials.

The general large‐scale synthesis of a family of single‐crystalline transition metal tungstate nanorods/nanowires is easily realized by a hydrothermal crystallization technique under mild conditions using cheap and simple inorganic salts as precursors. Uniform tungstate nanorods/nanowires such as MWO4(M = Zn, Mn, Fe), Bi2WO6, Ag2WO4, and Ag2W2O7with diameters of 20–40 nm, lengths of up to micrometers, and controlled aspect ratios can be readily obtained by hydrothermal transformation and recrystallization of amorphous particulates. This novel and efficient pathway toward various kinds of related low‐dimensional tungstate nanocrystals under mild conditions could open new opportunities for further investigating the novel properties of tungstate materials.

The baculovirus/insect cell system has been widely used for recombinant protein production. Since the finding that baculovirus was able to infect hepatocytes in 1995, various attempts to utilize baculovirus as a gene delivery vehicle into mammalian cells have been reported. In this study, we intended to explore the possibility of utilizing a baculovirus/mammalian cell system as a nonlytic, continuous protein production system. A recombinant baculovirus vector carrying enhanced green fluorescent protein (EGFP) under the control of cytomegalovirus immediate-early (CMV-IE) promoter was constructed. This virus was used to infect four common mammalian cell lines, and HeLa was found to yield the highest expression level. Additions of butyrate and valproic acid both enhanced the expression level, but butyrate exhibited a more profound effect. More importantly, HeLa cells were found to be superinfected by baculovirus, a result not observed in the conventional baculovirus/insect cell system. The effects of multiplicity of infection (MOI) and infection timing were also compared. High MOI up to 800 increased the expression in the short term (4 days), but the relatively higher cell death and lower cell density compromised the overall protein yield thereafter. The highest overall expression for a long term was obtained at MOI = 200 when the cells were initially infected at the mid-exponential phase and superinfected with additional baculovirus (MOI = 200) together with a one-time supplement of butyrate. In summary, the strategic infection and feeding enhanced the expression level 9-fold (compared with unsuperinfected culture) and prolonged the duration of expression to 16 days. This study reveals that this baculovirus/mammalian cell system has great potential to become a novel continuous, nonlytic expression system.

In DMSO cleavage of triethylsilyl (TES) ethers by o-iodoxybenzoic acid (IBX) was significantly faster than cleavage of tert-butyldimethylsilyl (TBS) ethers or further oxidation into carbonyl compounds. In most cases, TES protecting groups could be removed in good to excellent yields within 1 h, whereas similar TBS protecting groups remained intact under the same conditions. The procedure also could be adapted for direct one-pot conversion of TES ethers into carbonyl compounds.

Reactions of ZrCl4 with 2 or 3 equiv of Li[C4H3N(CH2NMe2)-2] in toluene afford ZrCl2[C4H3N(CH2NMe2)-2]2 (1) and ZrCl[C4H3N(CH2NMe2)-2]3 (2), respectively. Compounds 1 and 2 are characterized by NMR spectroscopy and single-crystal X-ray diffraction. Compound 1 exists as a six-coordinate octahedral structure with the two NMe2 units taking trans positions, and the seven-coordinate compound 2 shows a chloride-capped octahedral structure in which three bidentate pyrrole ligands form a pseudo-propeller structure with a δλλ form. A polymerization study shows that compounds 1 and 2 exhibit moderate activity toward ethylene, with compound 2 having higher activity.

Reactions of AlCl3 with 1 equiv of Li{C4H2N(CH2NMe2)2-2,5} or 2 equiv of Li{C4H3N(CH2NMe2)-2} in diethyl ether at −78 °C afforded AlCl2{C4H2N(CH2NMe2)2-2,5} (1) and AlCl{C4H3N(CH2NMe2)-2} (2), respectively. Alkylation of 1 with MeLi in diethyl ether generates the aluminum dimethyl complex 3. Compound 2 is thermally unstable and was converted to uncharacterized product in CHCl3 within 2 days at 80 °C. Compounds 1, 2, and 3 were characterized by NMR spectroscopy and X-ray structure determination.

Co-stimulator blockade and trans inhibitory signaling, using agents such as CTLA-4-Ig and Fas ligand (FasL) respectively have been invoked as alternative strategies for suppressing pathogenic T cells. This study describes a novel hetero-bifunctional fusion protein, CTLA-4-FasL, designed to combine within a single protein both co-stimulator blocking and trans inhibitory signaling potentials. A chimeric expression cassette, in which the ectodomain coding sequences for CTLA-4 and FasL were linked in-frame, was used to produce a CTLA-4-FasL fusion protein. CTLA-4-FasL binding to both B7-1/B7-2-expressing Daudi B cells and Fas-expressing Jurkat T cells was documented by immunofluorescence and flow cytometry. The capacity of CTLA-4-FasL to induce apoptosis in Jurkat targets was markedly enhanced by the addition of Daudi and other B7-1/B7-2⁺ B cell lines, which provided a membrane platform for the otherwise soluble CTLA-4-fusion protein. Moreover, in dual-chamber experiments, Daudi cells pre-coated with CTLA-4-FasL demonstrated Jurkat inhibitory activity that was cell-contact dependent. Significantly, when used to inhibit in vitro cellular proliferation of peripheral blood mononuclear cells, CTLA-4-FasL was ~1000-fold more potent than the extensively characterized CTLA-4-Ig fusion protein. Furthermore, the degree of inhibition induced by CTLA-4-FasL substantially surpassed that observed for CTLA-4-Ig and a soluble FasL when used in combination. CTLA-4-FasL represents the first of a novel class of fusion proteins, designated here as `trans signal converter proteins', that combine trans signal masking and direct trans signaling functions.

Co-stimulator blockade and trans inhibitory signaling, using agents such as CTLA-4-Ig and Fas ligand (FasL) respectively have been invoked as alternative strategies for suppressing pathogenic T cells. This study describes a novel hetero-bifunctional fusion protein, CTLA-4-FasL, designed to combine within a single protein both co-stimulator blocking and trans inhibitory signaling potentials. A chimeric expression cassette, in which the ectodomain coding sequences for CTLA-4 and FasL were linked in-frame, was used to produce a CTLA-4-FasL fusion protein. CTLA-4-FasL binding to both B7-1/B7-2-expressing Daudi B cells and Fas-expressing Jurkat T cells was documented by immunofluorescence and flow cytometry. The capacity of CTLA-4-FasL to induce apoptosis in Jurkat targets was markedly enhanced by the addition of Daudi and other B7-1/B7-2(+) B cell lines, which provided a membrane platform for the otherwise soluble CTLA-4-fusion protein. Moreover, in dual-chamber experiments, Daudi cells pre-coated with CTLA-4-FasL demonstrated Jurkat inhibitory activity that was cell-contact dependent. Significantly, when used to inhibit in vitro cellular proliferation of peripheral blood mononuclear cells, CTLA-4-FasL was approximately 1000-fold more potent than the extensively characterized CTLA-4-Ig fusion protein. Furthermore, the degree of inhibition induced by CTLA-4-FasL substantially surpassed that observed for CTLA-4-Ig and a soluble FasL when used in combination. CTLA-4-FasL represents the first of a novel class of fusion proteins, designated here as 'trans signal converter proteins', that combine trans signal masking and direct trans signaling functions.

The ultraviolet photodissociation of 1-bromo-3-fluorobenzene and 1-bromo-4-fluorobenzene at 266 nm has been performed on a universal crossed molecular beams machine combined with the photofragment translational spectroscopy (PTS) detection technique. The time-of-flight (TOF) spectra of Br and FC6H4 photofragments have been measured. The observed translational energy distributions P(Et) of photofragments revealed that about 46.8 ± 3.3% and 41.7 ± 3.0% of the available energy are partitioned into translational energy and the anisotropy parameter β is 0.7 ± 0.1 and −0.4 ± 0.1 for 1-bromo-3-fluorobenzene and 1-bromo-4-fluorobenzene, in accord with that of bromobenzene (−0.7), indicating significant change caused by the fluorine atom substitution. To better interpret the experimental results, ab initio calculations have been performed and the calculation results are in good agreement with the experimental results. A plausible photodissociation mechanism is suggested, and the substitution effect of the fluorine atom is discussed.

The ultraviolet photodissociation of nitrosobenzene at 266 nm has been performed on a universal crossed molecular beams machine with a TOFMS detector. The time-of-flight spectra of the NO and C6H5 photofragments have been measured. The TOF spectra evidence only one component. The measured photofragment translational energy distribution P(Et) reveals that about 29% of the available energy is partitioned into translational energy. The anisotropy parameter β at this wavelength is −0.64. From P(Et) and β, we deduce that during the photodissociation of C6H5NO, a perpendicular transition dominates over a parallel transition. Ab initio calculations were also performed to interpret the mechanism of the photodissociation.