Polyhydroxyalkanoates (PHAs) are a unique class of commercially manufactured biodegradable polyesters with properties suitable for partially substituting petroleum‐based plastics. However, high costs ...and low volumes of production have restricted their application as commodity materials. In this study, tri‐metallic complexes were developed for carbonylative polymerization via a dual catalysis strategy, and 17 products of novel PHAs with up to 38.2 kg mol−1 Mn values were discovered. The polymerization proceeds in a sequential fashion, which entails the carbonylative ring expansion of epoxide to β‐lactone and its subsequent ring‐opening polymerization that occurs selectively at the O‐alkyl bond via carboxylate species. The wide availability and structural diversity of epoxide monomers provide PHAs with various structures, excellent functionalities, and tunable properties. This study represents a rare example of the preparation of PHAs using epoxides and carbon monoxide as raw materials.
A dual catalysis strategy via carboxylate species featuring weak nucleophilicity and basicity is used for the direct carbonylative polymerization of various epoxides for the production of original advanced polyhydroxyalkanoates (PHAs) with high molecular weight and tunable functionalization. This study represents a rare example of PHAs synthesis using epoxides and carbon monoxide as raw materials.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Understanding the neural substrates of depression is crucial for diagnosis and treatment. Here, we review recent studies of functional and effective connectivity in depression, in terms of functional ...integration in the brain. Findings from these studies, including our own, point to the involvement of at least four networks in patients with depression. Elevated connectivity of a ventral limbic affective network appears to be associated with excessive negative mood (dysphoria) in the patients; decreased connectivity of a frontal‐striatal reward network has been suggested to account for loss of interest, motivation, and pleasure (anhedonia); enhanced default mode network connectivity seems to be associated with depressive rumination; and diminished connectivity of a dorsal cognitive control network is thought to underlie cognitive deficits especially ineffective top‐down control of negative thoughts and emotions in depressed patients. Moreover, the restoration of connectivity of these networks—and corresponding symptom improvement—following antidepressant treatment (including medication, psychotherapy, and brain stimulation techniques) serves as evidence for the crucial role of these networks in the pathophysiology of depression.
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BFBNIB, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
Applications of artificial intelligence in intelligent manufacturing： a review Li, Bo-hu; Hou, Bao-cun; Yu, Wen-tao ...
Frontiers of Information Technology & Electronic Engineering/Frontiers of Informaion Technology & Electronic Engineering,
2017, 1-2017, 2017-1-00, 20170101, Volume:
18, Issue:
1
Journal Article
Peer reviewed
Open access
Based on research into the applications of artificial intelligence （AI） technology in the manufacturing industry in recent years, we analyze the rapid development of core technologies in the new era ...of＇Internet plus AI＇, which is triggering a great change in the models, means, and ecosystems of the manufacturing industry, as well as in the development of AI. We then propose new models, means, and forms of intelligent manufacturing, intelligent manufacturing system architecture, and intelligent man- ufactudng technology system, based on the integration of AI technology with information communications, manufacturing, and related product technology. Moreover, from the perspectives of intelligent manufacturing application technology, industry, and application demonstration, the current development in intelligent manufacturing is discussed. Finally, suggestions for the application of AI in intelligent manufacturing in China are presented.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Herein, we introduce a variety of azopolyesters (azobenzene‐based polyesters) with remarkable intrinsic crystallinity and photoinduced reversible solid‐to‐liquid transition abilities from ...copolymerization of azobenzene‐based epoxides with cyclic anhydrides. The length of the soft alkyl side‐chain inlaid with azobenzenes and stereoregularity of main‐chain of azopolymers have tremendous effects on crystallization properties of the resulting polyesters with melting temperature (Tm) in the range of 51–251 °C. Moreover, some of azopolyesters possess excellently photoinduced reversible solid‐to‐liquid transition performance thanks to trans‐cis photoisomerization of azobenzenes. Trans‐azopolyesters are yellow solids with Tms or glass transition temperatures (Tgs) above room temperature, whereas cis‐polymers are red liquids with Tgs below −20 °C. These azopolyesters could be applied as novel light‐switchable adhesives for quartz/quartz, wood/wood and quartz/wood adhesion, with the strength in the range of 0.73–0.89 MPa for trans‐polymers. Conversely, the adhesion strength of liquefied cis‐azopolyesters generated from the irradiation of trans‐polymers by UV light was about 0.1 MPa, which shows light enable to control the adhesion process with high spatiotemporal resolution.
Azobenzene‐based polyesters (azopolyesters) from copolymerization of azobenzene‐based epoxides with cyclic anhydrides possess remarkable intrinsic crystallinity and novel photoinduced reversible solid‐to‐liquid transition abilities, owing to photoinduced trans‐cis isomerizations of azobenzenes being inlaid with soft alkyl side‐chain. This represents a new design strategy for the synthesis of reversible adhesives.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
5.
Essential elements for nuclear binding Lu, Bing-Nan; Li, Ning; Elhatisari, Serdar ...
Physics letters. B,
10/2019, Volume:
797, Issue:
C
Journal Article
Peer reviewed
Open access
How does nuclear binding emerge from first principles? Our current best understanding of nuclear forces is based on a systematic low-energy expansion called chiral effective field theory. However, ...recent ab initio calculations of nuclear structure have found that not all chiral effective field theory interactions give accurate predictions with increasing nuclear density. In this letter we address the reason for this problem and the first steps toward a solution. Using nuclear lattice simulations, we deduce the minimal nuclear interaction that can reproduce the ground state properties of light nuclei, medium-mass nuclei, and neutron matter simultaneously with no more than a few percent error in the energies and charge radii. We find that only four parameters are needed. With these four parameters one can accurately describe neutron matter up to saturation density and the ground state properties of nuclei up to calcium. Given the absence of sign oscillations in these lattice Monte Carlo simulations and the mild scaling of computational effort scaling with nucleon number, this work provides a pathway to high-quality simulations in the future with as many as one or two hundred nucleons.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Synthesis of stereoregular polyesters with main-chain chirality was achieved for the first time by the asymmetric copolymerization of meso-epoxides and cyclic anhydrides using catalyst systems based ...on enantiopure bimetallic complexes. The combination of the biphenol-linked dinuclear aluminum complex with tert-butyl groups in the phenolate ortho-positions and a nucleophilic co-catalyst was found to be more efficient in catalyzing this asymmetric copolymerization, affording enantiomerically enriched polyesters (up to 91% ee) with completely alternating structure and narrow molecular weight distribution. It was discovered that the isotactic-enriched poly(cyclopentene phthalate) is a typical semicrystalline material with a melting endothermic peak at 221 °C. This study is expected to provide a promising route to prepare various stereoregular polyesters having a wide variety of physical properties and degradability.
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IJS, KILJ, NUK, PNG, UL, UM
Dysfunction of the circadian rhythm is one of most common nonmotor symptoms in Parkinson's disease (PD), but the molecular role of the circadian rhythm in PD is unclear. We here showed that ...inactivation of brain and muscle ARNT‐like 1 (BMAL1) in 1‐methyl‐4‐phenyl‐1,2,4,5‐tetrahydropyridine (MPTP)‐treated mice resulted in obvious motor functional deficit, loss of dopaminergic neurons (DANs) in the substantia nigra pars compacta (SNpc), decrease of dopamine (DA) transmitter, and increased activation of microglia and astrocytes in the striatum. Time on the rotarod or calorie consumption, and food and water intake were reduced in the Bmal1−/− mice after MPTP treatment, suggesting that absence of Bmal1 may exacerbate circadian and PD motor function. We observed a significant reduction of DANs (~35%) in the SNpc, the tyrosine hydroxylase protein level in the striatum (~60%), the DA (~22%), and 3,4‐dihydroxyphenylacetic acid content (~29%), respectively, in MPTP‐treated Bmal1−/− mice. Loss of Bmal1 aggravated the inflammatory reaction both in vivo and in vitro. These findings suggest that BMAL1 may play an essential role in the survival of DANs and maintain normal function of the DA signaling pathway via regulating microglia‐mediated neuroinflammation in the brain.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
To determine distribution of severe acute respiratory syndrome coronavirus 2 in hospital wards in Wuhan, China, we tested air and surface samples. Contamination was greater in intensive care units ...than general wards. Virus was widely distributed on floors, computer mice, trash cans, and sickbed handrails and was detected in air ≈4 m from patients.
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DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The precise synthesis of poly(thioester)s with diverse structures is still a significant challenge in the polymeric materials field. Herein, we report a novel approach to the synthesis of ...well‐defined poly(thioester)s by the controlled alternating copolymerization of cyclic thioanhydrides and episulfides induced by simple organic ammonium salts. Both the cation and anion have strong effects on the copolymerization. PPNOAc (PPN=bis(triphenylphosphine)iminium) with a bulky cation was proven to be efficient in initiating this polymerization, yielding poly(thioester)s with a completely alternating structure, controlled molecular weight, and narrow polydispersity. The poly(thioester) obtained from succinic thioanhydride and propylene sulfide is a typical semicrystalline material, possessing a high refractive index of up to 1.78. Because it uses readily available monomers, this method is expected to open up a new route to poly(thioester)s with diverse structures and properties.
Bulky is best: The synthesis of well‐defined poly(thioester)s by the controlled alternating copolymerization of cyclic thioanhydrides and episulfides can be induced by simple organic ammonium salts. Both the cation and anion have strong effects, and a bulky cation was efficient in initiating the polymerization, resulting in poly(thioester)s with a completely alternating structure, controlled molecular weight, and narrow polydispersity.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
A new, general oxidative route to transformations of 1,3‐dicarbonyl compounds to 1,2‐dicarbonyl compounds by merging copper and I2 catalysis is described. This method is applicable to broad ...1,3‐dicarbonyl compounds, including 1,3‐diketones, 1,3‐keto esters and 1,3‐keto amides. Mechanistical studies show that the reaction is achieved via the C–C bond cleavage and CO release cascades.
DMSO multi‐tasking enabled a copper/I2‐cocatalyzed transformations of 1,3‐dicarbonyl compounds to 1,2‐dicarbonyl compound is depicted. This method is achieved through a sequence of C–C oxidative cleavage and CO release using DMSO as oxidant, oxygen source and solvent, which is general to a wide range of 1,3‐dicarbonyl compounds, including 1,3‐diketones, 1,3‐keto esters and 1,3‐keto amides, with excellent selectivity and a broad functional group tolerance.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
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