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1.
Chemistry ; 23(57): 14375-14383, 2017 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-28758338

RESUMO

The buckybowl trichalcogenasumanenes show cleavage of flanking benzene ring upon oxidation, which leads their dissection by fusing various amidine moieties onto peripheral region. By gradually increasing the ring size of amidine from five- to six- and seven-membered, the molecule engineering results in the [7-5-6]-, [7-6-6]-, and [7-7-6]-fused polycycles. Three systems are distinct in the molecular geometries, packing motifs, and optoelectronic properties. The [7-5-6]-fused case adopts the flat backbone, displays strong emission with the fluorescence quantum yield up to 52.3 %, and undergoes a two-photon absorption process. The [7-6-6]-fused one is of a curvature with molecular geometry inversion, forms a tight stack of curved π-system, shows broad absorption extended to 700 nm, and exhibits the p-type semiconducting behavior with hole mobility of 4.4×10-3  cm2 V-1 s-1 . The [7-7-6]-fused one possesses the highly twisted skeleton to show stable chirality, and exhibits red emission in both solution and solid state. The surgery on trichalcogenasumanene is a promising approach to create polycycles with diverse functionalities.

2.
Angew Chem Int Ed Engl ; 56(43): 13470-13474, 2017 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-28834589

RESUMO

The regioselective transformation of heterobuckybowl trichalcogenasumanenes 1 a,b at peripheral butoxy groups afforded trichalcogenasumanene ortho-quinones 2 a,b. Compounds 2 a,b are distinct from 1 a,b in terms of their molecular geometry and electronic state; that is, they have a shallower bowl depth and show absorbance in the NIR region. The reaction of 2 a,b with diamines resulted in a variety of heteropolycycles, including molecular spoon 3 a-6 a, planar π-systems 3 b-6 b, and highly twisted [7-6-6]-fused systems 7 a,b. These new heteropolycycles had different optical/electrical properties: 4 a,b showed hole mobility of approximately 0.002 cm2 V-1 s-1 , 6 a displayed red emission in both solution and the solid state, and 7 a,b formed tight stacks of the curved π-surface.

3.
Rev Sci Instrum ; 95(4)2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38619549

RESUMO

The vortex flowmeter occupies a vital position in flow measurement with its unique advantages. It is essentially a fluid vibration instrument, and its measurement process is susceptible to interference, which seriously affects measurement accuracy. In particular, at low flow rates, it is an urgent problem to extract vortex signals from the complex noise. Among many signal processing methods, Empirical Mode Decomposition (EMD) is a time-frequency analysis method suitable for nonlinear, non-stationary signals. EMD can adaptively decompose noisy signals into noise and useful signal components arranged from high frequency to low frequency. For the above problems, an innovative, improved EMD method is proposed in this paper. The digital filter is designed according to the amplitude-frequency characteristic of vortex signals. After filtering, the vortex signal is adjusted to a fixed value, and high-frequency noise is filtered. According to the consistency of the filtered signal's amplitude, we design a decomposition stop criterion for EMD to process the output signal of the vortex sensor. This method not only maintains the characteristic of adaptive decomposition in EMD but also completes the automatic extraction of the vortex signal under complex noise. It provides a new comprehensive method for realizing high-precision and anti-interference vortex flowmeters.

4.
Brain Behav ; 13(8): e3178, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37479950

RESUMO

OBJECTIVE: The phenotype of the chromosomal aberration 47, XXY exhibits considerable heterogenicity. In addition, epilepsy is extremely uncommon in individuals with this chromosomal disorder. As a result, the clinical characteristics of epilepsy in these patients remain poorly understood. METHODS: Clinical data and the evolution of epilepsy in a boy diagnosed with chromosomal aberration 47, XXY were collected and analyzed. Furthermore, a systematic literature review was conducted to examine the relationship between chromosomal aberration 47, XXY and epilepsy in children. RESULTS: We identified a novel phenotype associated with the chromosomal anomaly 47, XXY in a 2-year-2-month-old boy who presented with self-limited epilepsy with autonomic seizures at onset, followed by developmental and/or epileptic encephalopathy with spike-wave activation in sleep (D/EE-SWAS), which was responsive to corticosteroid treatment. Including the present case, we analyzed 21 cases of children diagnosed with epilepsy due to the presence of the 47, XXY chromosomal anomaly. The most common types of epilepsy were focal combined generalized epilepsy (n = 9), epileptic spasms (n = 6), and generalized epilepsy (n = 4). There were six cases of infantile epileptic spasm syndrome (IESS) (n = 5) and developmental and epileptic encephalopathy (n = 1), one case of Lennox-Gastaut syndrome, and one case of D/EE-SWAS. Apart from corticosteroids in IESS, 15 antiseizure medications (ASMs) were prescribed to eight children in this cohort, with valproate (n = 5) being the most frequently used. CONCLUSIONS: The epilepsy types and syndromes associated with the chromosomal anomaly 47, XXY demonstrated considerable heterogeneity. Among the observed phenotypes, IESS and focal epilepsy, which displayed partial responsiveness to multiple ASMs, were the most prevalent.


Assuntos
Epilepsias Parciais , Epilepsia , Síndromes Epilépticas , Espasmos Infantis , Humanos , Epilepsia/tratamento farmacológico , Epilepsia/genética , Aberrações Cromossômicas , Espasmos Infantis/tratamento farmacológico , Espasmos Infantis/genética
5.
IEEE Trans Image Process ; 30: 5426-5438, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34097609

RESUMO

Existing defocus blur detection (DBD) methods usually explore multi-scale and multi-level features to improve performance. However, defocus blur regions normally have incomplete semantic information, which will reduce DBD's performance if it can't be used properly. In this paper, we address the above problem by exploring deep ensemble networks, where we boost diversity of defocus blur detectors to force the network to generate diverse results that some rely more on high-level semantic information while some ones rely more on low-level information. Then, diverse result ensemble makes detection errors cancel out each other. Specifically, we propose two deep ensemble networks (e.g., adaptive ensemble network (AENet) and encoder-feature ensemble network (EFENet)), which focus on boosting diversity while costing less computation. AENet constructs different light-weight sequential adapters for one backbone network to generate diverse results without introducing too many parameters and computation. AENet is optimized only by the self- negative correlation loss. On the other hand, we propose EFENet by exploring the diversity of multiple encoded features and ensemble strategies of features (e.g., group-channel uniformly weighted average ensemble and self-gate weighted ensemble). Diversity is represented by encoded features with less parameters, and a simple mean squared error loss can achieve the superior performance. Experimental results demonstrate the superiority over the state-of-the-arts in terms of accuracy and speed. Codes and models are available at: https://github.com/wdzhao123/DENets.

6.
Artigo em Inglês | MEDLINE | ID: mdl-31562089

RESUMO

Recent state-of-the-art methods on focus region detection (FRD) rely on deep convolutional networks trained with costly pixel-level annotations. In this study, we propose a FRD method that achieves competitive accuracies but only uses easily obtained bounding box annotations. Box-level tags provide important cues of focus regions but lose the boundary delineation of the transition area. A recurrent constraint network (RCN) is introduced for this challenge. In our static training, RCN is jointly trained with a fully convolutional network (FCN) through box-level supervision. The RCN can generate a detailed focus map to locate the boundary of the transition area effectively. In our dynamic training, we iterate between fine-tuning FCN and RCN with the generated pixel-level tags and generate finer new pixel-level tags. To boost the performance further, a guided conditional random field is developed to improve the quality of the generated pixel-level tags. To promote further study of the weakly supervised FRD methods, we construct a new dataset called FocusBox, which consists of 5000 challenging images with bounding box-level labels. Experimental results on existing datasets demonstrate that our method not only yields comparable results than fully supervised counterparts but also achieves a faster speed.

7.
Chem Commun (Camb) ; 54(78): 10981-10984, 2018 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-30209446

RESUMO

Two flanking benzene rings on trichalcogenasumanenes (1a/1b) were opened upon oxidation, and the successive ring reconstruction afforded donor-acceptor type polycycles containing diimide units (3a/3b). 3a and 3b show excellent optical-limiting properties superior to C60.

8.
Chem Commun (Camb) ; 53(83): 11407-11409, 2017 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-28983539

RESUMO

The charge transport properties of a bowl-shaped sumanene derivative with dense convex-concave columnar packing were studied. Single-crystal microribbons were grown by solution casting. Organic field-effect transistors based on individual single-crystal ribbons displayed a high hole mobility up to 0.37 cm2 V-1 s-1, which was one of the highest mobilities for buckybowl aromatics.

9.
Chem Commun (Camb) ; 53(9): 1546-1549, 2017 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-28094368

RESUMO

Thiophene rings in trithiasumanene (1) are oxidized regioselectively to form tris(S,S-dioxide)-trithiasumanene (3). Compound 3 displays strong indigo fluorescence in both solution and the solid state, and forms a 1 : 1 cocrystal with HBT to give a yellow emission in crystalline form.

10.
Chem Commun (Camb) ; 52(100): 14486-14489, 2016 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-27904895

RESUMO

Tritellurasumanene is synthesized from a triphenylene skeleton via ultrasound assisted one-pot reaction. This compound adopts a flat conjugated system and displays TeTe (3.83 Å) interactions in the solid state. Its optical properties and chemical reactivity are quite different from those of its trithia- and triselena-analogues.

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