Highly Sensitive and Selective Fluorescent Probe for Detection of Fe3+ Based on Rhodamine Fluorophore.

A simple rhodamine-based fluorescent probe L1, which exhibits good response to Fe3+ in CH3CN/Tris-HCl buffer (v:v = 9:1, pH 7.00) solution. With the experimental conditions optimized, the probe L1 could be used as a fluorescent and colorimetric probe for Fe3+ with the detection limit as low as 0.29 µM. The binding constant (Ka) of Fe3+ binding to the probe L1 were calculated to be 1.4 × 1010 M-2, respectively from a Benesi-Hildebrand plot. With the addition of Fe3+, the CH3CN/Tris-HCl buffer (v:v = 9:1, pH 7.00) solution of the probe L1 exhibited a obviously color change from transparent to pink with distinctive changes. More importantly, the recognition process of the probe L1 for Fe3+ was chemically reversible on the addition AcO-. Graphical Abstract.

A One-Pot Tandem Strategy in Catalytic Asymmetric Vinylogous Aldol Reaction of Homoallylic Alcohols.

Reported is a rationally-designed one-pot sequential strategy that allows homoallylic alcohols to be employed in a catalytic, asymmetric, direct vinylogous aldol reaction with a series of activated acyclic ketones, including trifluoromethyl ketones, γ-ketoesters, and α-keto phosphonates, in high yields (up to 95%) with excellent regio- and enantio-selectivity (up to 99% ee). This modular combination, including Jones oxidation and asymmetric organocatalysis, has satisfactory compatibility and reliability even at a 20 mmol scale, albeit without intermediary purification.

Dual NIR-channel fluorescent probe for detecting ONOO- in vitro and vivo.

As one of endogenous reactive oxygen species (ROS), peroxynitrite (ONOO-) performs various functions in both pathological and physiological mechanisms. In this work, an optical and near-infrared (NIR) fluorescent probe (NX), which based on 3-dihydro-1H-xanthene and 2-dicyanomethylene-3-cyano-4,5,5-trimethyl-2,5-dihydrofuran (TCF) group was designed and prepared to detect ONOO-. This probe revealed an obvious optical and a fluorescent response when ONOO- was present and it exhibited higher selectivity over other ROS. Especially, the dual NIR fluorescence changes at 660 and 800 nm allowed quantitative detection of ONOO- in the range of 15-40 µM, and the detection limit was 82 nM. Finally, the probe was effectively employed to visualize exogenous and endogenous ONOO- in HepG2 cells and zebrafish, respectively. All the results indicated the dual NIR-channel probe could serve as a potent detecting tools in studying ONOO- in vitro and in vivo.

Soluble CD80 oral delivery by recombinant Lactococcus suppresses tumor growth by enhancing antitumor immunity.

CD80 is an important co-stimulatory molecule that participates in the immune response. Soluble CD80 can induce T cell activation and overcome PDL1-mediated immune suppression. In this study, we aimed to construct recombinant Lactococcus lactis for oral delivery of the soluble CD80 (hsCD80) protein or the fusion protein containing the cholera toxin B subunit (CTB) and hsCD80 (CTB-hsCD80) under the control of the nisin-inducible expression system. The recombinant L. lactis expressed and secreted hsCD80 or CTB-hsCD80 fusion proteins after induction by nisin in vitro and in the enteric cavity. Additionally, the CTB-hsCD80 fusion protein showed uptake by intestinal epithelial cells, was cleaved by the furin protease, and was released as free hsCD80 protein into the blood circulation. Orally administered hsCD80 and CTB-hsCD80 containing L. lactis increased the proportion of activated T cells in the spleen and intestinal epithelium, inhibited tumor growth, and prolonged the survival of tumor-bearing mice. The hsCD80-containing L. lactis showed greater therapeutic effects on primary colonic adenoma in APCmin/- mice and completely suppressed tumor growth. Further, recombinant CTB-hsCD80 in L. lactis was more efficient than hsCD80-containing bacteria in inhibiting the growth of xenografted colon cancer and melanoma cells. hsCD80 engineered probiotics may serve as a promising new approach for antitumor immunotherapy, especially for colorectal cancer.

(1-Oxo-2,6,7-trioxa-1-phosphabicyclo-[2.2.2]octan-4-yl)methyl 4-methyl-benzene-sulfonate.

In the title compound, C(12)H(15)O(7)PS, the P atom has a distorted tetra-hedral environment. The P-O-C-C torsion angles deviate significantly from zero [average = 12.0 (3)°], indicating that the bicyclic OP(OCH(2))(3)C cage is strained. In the crystal, weak C-H⋯O inter-actions consolidate the packing.

7-[(5,5-Dimethyl-2-oxido-1,3,2-dioxaphosphinan-2-yl)-oxy]-4-methyl-2H-chromen-2-one.

The title compound, C(15)H(17)O(6)P, was obtained from a reaction of 4-methyl-7-hy-droxy-coumarin and 2-chloro-5,5-dimethyl-1,3,2-dioxaphosphinane 2-oxide. There are two mol-ecules in the asymmetric unit in which the benzopyran ring system is almost planar [r.m.s. deviation for each molecule = 0.003 Å]. In the crystal, C-H⋯O hydrogen bonds and π-π stacking inter-actions [with centroid-centroid distances of 3.743 (3) and 3.727 (3) Å] link the two mol-ecules. The dioxaphospho-rinane ring adopts a chair conformation in both asymmetric molecules.

Improving obesity and lipid metabolism using conjugated linoleic acid.

BACKGROUND: Conjugated linoleic acid (CLA) can prevent fatty acid accumulation induced by a high-fructose diet and improve lipid metabolism disorders in patients. OBJECTIVES: We aimed to investigate the effect of CLA on obesity and lipid metabolism and its possible mechanism. METHODS: Eight-month-old male BKS.Cg-Dock7m +/+ Leprdb /JNju (db/db) mice (n = 12) were fed a CLA mix composed of equivalent c9, t11-CLA and t10, c12-CLA for 1 month. The effect of CLA on body weight, water and food intake, and triglyceride (TG) and total cholesterol (TC) levels was investigated. PPARα, PPARγ and CD36 expression was determined by quantitative PCR and western blotting. Additionally, the expression of these three genes was studied in HepG2 cells treated with CLA and linoleic acid. RESULTS: CLA treatment notably reduced the dietary and water intake of db/db mice, effectively reduced body weight, and decreased serum TG and TC levels (p < 0.05). Increased expression of PPARα (p < 0.05) and decreased expression of CD36 (p < 0.001) were observed in the liver of mice that were fed CLA. CLA increased PPARα expression (p < 0.001) and decreased PPARγ (p < 0.001) and CD36 expression (p < 0.01) in HepG2 cells. CONCLUSIONS: Our results showed that CLA can improve lipid metabolism in obese mice through upregulation of PPARα expression and downregulation of CD36 expression.

High Thermoelectric Performance of p-Type Bi0.4Sb1.6Te3+x Synthesized by Plasma-Assisted Ball Milling.

The exploration of new synthesis methods is important for the improvement of the thermoelectric property of a material for the different mechanisms of microstructure fabrication, surface activity modulation, and particle refinement. Herein, we prepared p-Bi2Te3 bulk materials by a simple synthesis method of the plasma-assisted ball milling, which yielded finer nanopowders, higher texture of in-plane direction, and higher efficiency compared to the traditional ball milling, favoring the simultaneous improvement of electrical and thermal properties. When combined with the Te liquid sintering, nano-/microscale hierarchical pores were fabricated and the carrier mobility was also increased, which together resulted in the low lattice thermal conductivity of 0.52 W·m-1·K-1 and the high power factor of 43.4 µW·cm-1·K-2 at 300 K, as well as the ranking ahead zT of 1.4@375 K. Thus, this work demonstrated the advantages of plasma-assisted ball milling in highly efficient synthesis of p-type Bi2Te3 with promising thermoelectric performance, which can also be utilized to prepare other thermoelectric materials.

ICT-modulated NIR water-soluble fluorescent probe with large Stokes shift for selective detection of cysteine in living cells and zebrafish.

The fluorescent probes with good water-solubility, long-wavelength emission and large Stokes shift are greatly desirable for in vivo detection. Herein, we designed a novel 1,8-naphthalimide-based near-infrared (NIR) optical and fluorescent probe (NTC) for sensing cysteine (Cys). Using acrylate as the recognition site, the probe demonstrated high selectivity and sensitivity for Cys with a low detection limit (0.093 µM) in aqueous buffer solution due to the excellent water-solubility. Upon the reaction with Cys, the recovery of intramolecular charge transfer (ICT) in the probe led to about 40-fold fluorescence enhancement. Furthermore, the reaction result was investigated by 1H NMR, and HRMS analyses, and the sensing mechanism was validated by quantum calculations. Finally, NTC was applied to image exogenous and endogenous Cys in HeLa cells and zebrafish selectively, implying that the probe possessed great potential application in biological fluorescence sensing.

2-Amino-4,6-dimethyl-pyrimidin-1-ium 1-oxo-2,6,7-trioxa-1λ-phosphabicyclo-[2.2.2]octane-4-carboxyl-ate.

In the title compound, C(6)H(10)N(3) (+)·C(5)H(6)O(6)P(-), the cation and anion are linked by pairs of N-H⋯O hydrogen bonds. There are additional inter-molecular N-H⋯N hydrogen bonds, which generate centrosymmetric tetramers of two cations and two anions.

Ethyl 3-[2-(p-tolyl-carbamothio-yl)hydrazinyl-idene]butano-ate.

The title compound, C(14)H(19)N(3)O(2)S, was obtained from a condensation reaction of N-(p-tol-yl)hydrazinecarbothio-amide and ethyl acetoacetate. The mol-ecule assumes an E configuration; the thio-semicarbazide and ester groups are located on the opposite sides of the C=N bond. The almost planar thio-semicarbazide unit (r.m.s. deviation = 0.0130 Å) is tilted at a dihedral angle of 49.54 (12)° with respect to the benzene ring. Inter-molecular N-H⋯N and N-H⋯S hydrogen bonding stabilizes the crystal structure. The eth-oxy group of the ester unit is disordered over two positions, with a site-occupancy ratio of 0.680 (10):0.320 (10).

Novel Lactobacillus reuteri HI120 Affects Lipid Metabolism in C57BL/6 Obese Mice.

Intestinal probiotics are a primary focus area of current medical research. Probiotics such as bifidobacteria and lactobacilli can positively impact obesity and other metabolic diseases by directly or indirectly affecting lipid metabolism. However, the precise mechanisms of these effects remain unclear. In our previous work, the novel strain Lactobacillus reuteri HI120 was isolated and identified. HI120 expresses high levels of linoleic isomerase, resulting in the production of large amounts of conjugated linoleic acid (CLA) when mixed with linoleic acid (LA). As HI120 can efficiently transform LA into CLA, the effect of HI120 on the lipid metabolism in C57BL/6 obese mice was studied and the underlying molecular mechanism was explored in vitro. The results revealed no significant change in the diet, body weight, and serum triglyceride levels in mice. However, serum cholesterol levels were significantly decreased. The underlying mechanism may involve a CLA-mediated reduction in the gene expression levels of NPC1L1, SREBP-2, and HMG-CR, resulting in reduced cholesterol synthesis and absorption. Thus, HI120 can be developed as a potential probiotic formulation. After oral administration, LA from certain food sources can be converted into CLA in the human intestine to contribute to the prevention and treatment of obesity and hyperlipidemia.

First measurements of the radiation dose on the lunar surface.

Human exploration of the Moon is associated with substantial risks to astronauts from space radiation. On the surface of the Moon, this consists of the chronic exposure to galactic cosmic rays and sporadic solar particle events. The interaction of this radiation field with the lunar soil leads to a third component that consists of neutral particles, i.e., neutrons and gamma radiation. The Lunar Lander Neutrons and Dosimetry experiment aboard China's Chang'E 4 lander has made the first ever measurements of the radiation exposure to both charged and neutral particles on the lunar surface. We measured an average total absorbed dose rate in silicon of 13.2 ± 1 µGy/hour and a neutral particle dose rate of 3.1 ± 0.5 µGy/hour.

[Conjugated linoleic acid improves glucose and lipid metabolism in diabetic mice].

OBJECTIVE: To analyze the effect of conjugated linoleic acid (CLA) on glucose and lipid metabolism in obese diabetic (db/db) mice. METHODS: db/db mice were randomized for treatment with saline or CLA mixture administered intragastrically. The changes in body weight, dietary intake, water intake, oral glucose tolerance, triglyceride and total cholesterol were recorded after the treatments. HE staining and oil red O staining were used to assess liver pathologies and fatty acid content. The expression levels of PPARα, PPARγ, CD36, CHREBP and SREBP-1c were detected using real-time PCR and Western blotting. HepG2 cells were treated with CLA and linoleic acid and the expressions of PPARα, ACC, P-ACC, and CD36 were detected; the level of acetyl-CoA in the cell supernatant was detected using ELISA. RESULTS: CLA treatment obviously reduced the dietary and water intake of db/db mice, effectively reduced the body weight and decreased serum triglyceride and cholesterol levels (P < 0.05). CLA significantly reduced fasting blood glucose, increased glucose tolerance, reduced the accumulation of lipid droplets in the liver and improved lipid metabolism in db/db mice. The mice showed significantly increased expression of PPARα (P < 0.05) and lowered CD36 expression (P < 0.001) in the liver after CLA treatment. Cellular experiments showed that CLA significantly up-regulated PPARα (P < 0.001) and P-ACC and decreased the expression of CD36 (P < 0.01). ELISA showed that acetyl-CoA was significantly up-regulated in the cells after CLA treatment (P < 0.01). CONCLUSIONS: The mixture of two conjugated linoleic acid isomers can reduce fasting blood glucose, increase glucose tolerance and improve glycolipid metabolism in db/db mice by enhancing the expression of PPARα, increasing P-ACC and inhibiting CD36 expression.