3,660 research outputs found
Selective disinfection based on directional ultraviolet irradiation and artificial intelligence
Ultraviolet disinfection has been proven to be effective for surface sanitation. Traditional ultraviolet disinfection systems generate omnidirectional radiation, which introduces safety concerns regarding human exposure. Large scale disinfection must be performed without humans present, which limits the time efficiency of disinfection. We propose and experimentally demonstrate a targeted ultraviolet disinfection system using a combination of robotics, lasers, and deep learning. The system uses a laser-galvo and a camera mounted on a two-axis gimbal running a custom deep learning algorithm. This allows ultraviolet radiation to be applied to any surface in the room where it is mounted, and the algorithm ensures that the laser targets the desired surfaces avoids others such as humans. Both the laser-galvo and the deep learning algorithm were tested for targeted disinfection
trans-Diaquabis[5-carboxy-4-carboxylato-2-(4-pyridinio)-1H-imidazol-1-ido-κ2 N 3,O 4]iron(II)
In the title complex, [Fe(C10H6N3O4)2(H2O)2], the FeII atom is located on a twofold rotation axis and is coordinated by two trans-positioned N,O-bidentate and zwitterionic 5-carboxy-2-(pyridinium-4-yl)-1H-imidazol-1-ide-4-carboxylate H2PIDC− ligands and two water molecules in a distorted environment. In the crystal packing, a three-dimensional network is constructed via hydrogen-bonding involving the water molecules, uncoordinated imidazole N atom, protonated pyridine N and carboxylate O atoms
Carbohydrate metabolism in grape cultivars that differ in sucrose accumulation
Sugar concentrations and sucrose-metabolism related enzyme activities in berries and leaves were investigated during berry development using grape cultivars with different sucrose concentrations. Sucrose concentration was significantly negatively related to acid invertase activity in berries. Acid invertase showed the lowest activities in berries of high-sucrose cultivars, ‘Honey Juice’ and ‘B180’, and the highest in tracesucrose cultivars, ‘Concord’, ‘Jingxiu’, and ‘Jingya’. Acid invertase activities in berries of low-sucrose cultivar ‘Canadice’ were between high- and trace-sucrose cultivars. There was no significant difference in glucose and fructose concentrations, the activities of neutral invertase, sucrose synthase and sucrose phosphate synthase in berries among high-, low- and trace-sucrose cultivars as acid invertase. Sugar concentrations and sucrose-metabolism related enzymes activities in leaves also did not show such difference among all cultivars. The results suggest that differences in sucrose concentration in berries among grape cultivars mainly be due to acid invertase activity. In addition, the final sucrose concentration in berries at maturity for a grape cultivar might be decided at véraison, and véraison is the key period for sucrose accumulation.
trans-Diaquabis[5-carboxy-4-carboxylato-2-(4-pyridinio)-1H-imidazol-1-ido-κ2 N 3,O 4]zinc(II)
In the title complex, [Zn(C10H6N3O4)2(H2O)2], the ZnII atom is located on a twofold rotation axis and is coordinated by two trans-positioned N,O-bidentate and zwitterionic 5-carboxy-4-carboxylato-2-(4-pyridinio)-1H-imidazol-1-ide (H2PIDC−) ligands and two water molecules, defining a distorted octahedral environment. The complete solid-state structure can be described as a three-dimensional supramolecular framework, stabilized by extensive hydrogen-bonding interactions involving the coordinated water molecules, uncoordinated imidazole N atom, protonated pyridine N and carboxylate O atoms of the H2PIDC− ligands
trans-Diaquabis[5-carboxy-2-(3-pyridyl)-1H-imidazole-4-carboxylato-κ2 N 3,O 4]iron(II)
In the title complex, [Fe(C10H6N3O4)2(H2O)2], the FeII atom is located on an inversion centre and is trans-coordinated by two N,O-bidentate 5-carboxy-2-(3-pyridyl)-1H-imidazole-4-carboxylate ligands and two water molecules, defining a distorted octahedral environment. A two-dimensional network of N—H⋯O and O—H⋯O hydrogen bonds extending parallel to (110) helps to stabilize the crystal packing
Aqueous Extracts of Herba Cistanche
Traditional Chinese medicine was reported to have good effects in treating functional constipation. This work attempted to prove the effects of aqueous extracts of Herba Cistanche (AEHC) on STC treatment and to determine the possible mechanisms by a loperamide-induced slow transit constipation (STC) model. HPLC was performed for identification and confirmation of the bioactive components in the AEHC. It was found that AEHC attenuated STC responses based on increased fecal quantity, moisture content, and intestinal transit rate, as well as serum levels of GAS, MTL, SS, and CGRP. The protein and mRNA levels of c-kit, a labeling of interstitial cells of Cajal (ICC), also increased. Meanwhile, only the protein level of SCF, a ligand of c-kit, increased. The analysis of our data suggested that AEHC could obviously improve the function of ICC via a signaling pathway involving PI3K, SCF, and c-kit and enhance colonic motility indices such as GAS, MTL, SS, and CGRP. It is interesting to note that AEHC appeared to be effective on constipation, so further experiments are necessary to clarify the exact mechanisms involved
Conformationally Strained trans- Cyclooctene (sTCO) Enables the Rapid Construction of 18 F-PET Probes via Tetrazine Ligation
The bioorthogonal reaction between tetrazines and trans-cyclooctenes is a method for the rapid construction of F-18 probes for PET imaging. Described here is a second generation 18F-labeling system based on a conformationally strained trans-cyclooctene (sTCO)—a dienophile that is approximately 2 orders of magnitude more reactive than conventional TCO dienophiles. Starting from a readily prepared tosylate precursor, an 18F labeled sTCO derivative (18F-sTCO) could be synthesized in 29.3 +/- 5.1% isolated yield and with high specific activity. Tetrazine ligation was carried out with a cyclic RGD-conjugate of a diphenyl-s-tetrazine analogue (RGD-Tz) chosen from a diene class with an excellent combination of fast reactivity and stability both for the diene as well as the Diels-Alder adduct. For both the tetrazine and the sTCO, mini-PEG spacers were included to enhance solubility and improve the in vivo distribution profile of the resulting probe. Extremely fast reactivity (up to 2.86 x 105 M-1s-1 at 25 °C in water) has been observed in kinetic studies in the reaction of sTCO with diphenyl-s-tetrazine derivatives. A kinetic study on sTCO diastereomers in 55:45 MeOH:water showed that the syn-diastereomer displayed slightly faster reactivity than the anti-diastereomer. An 18F-sTCO conjugate with RGD-Tz demonstrated prominent and persistent tumor uptake in vivo with good tumor-to-background contrast. Unlike most radiolabeled RGD peptides, the tumor uptake of this PET agent increased from 5.3 +/- 0.2% ID/g at 1 h post injection (p.i.), to 8.9 +/- 0.5% ID/g at 4 h p.i., providing evidence for prolonged blood circulation. These findings suggest that tetrazine ligations employing 18F-sTCO should serve as a powerful and general platform for the rapid construction of peptide or protein derived PET agents
Stimuli-responsive 2D polyelectrolyte photonic crystals for optically encoded pH sensing.
A versatile photonic crystal sensing motif based on a twodimensional (2D) inverse opal monolayer of stimuli-responsive polyelectrolyte gel with tunable optical properties is reported. The photonic membrane shows prompt response to pH and can be readily
read out from either its optical spectra or interference colours
The study on the structure of exotic states via beauty-hadron decays in collisions at
A dynamically constrained phase-space coalescence (DCPC) model was introduced
to study the exotic state yield for three possible
structures: tetraquark state, nuclear-like state, and molecular state
respectively, where the hadronic final states generated by the parton and
hadron cascade model (PACIAE). The / cross-section
ratio from beauty-hadron decays (non-prompt) based on the or
bound state in the decay chains as a
function of charged-particle multiplicity and transverse momentum in
collisions at are calculated. A tetraquark state
scenario from PACIAE+DCPC model shows better agreement with the LHCb and ATLAS
measurements for the non-prompt / cross-section
ratio distributions, indicating that the is more likely to
be a compact tetraquark state
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