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1.
J Pediatr Orthop B ; 30(3): 211-217, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33767123

RESUMO

Limited evidence is available in the literature regarding the fate of the unfused structural thoracic curve following selective thoracolumbar-lumbar curve fusion (SLF) in Lenke 6C adolescent idiopathic scoliosis (AIS) patients. Therefore, we compared the outcomes of SLF between Lenke 6C and 5C AIS patients. We retrospectively reviewed 31 patients Lenke 5C (n = 18) and Lenke 6C (n = 13) AIS patients who underwent SLF at a single institution. Multiple radiological parameters were measured using whole-spine radiographs taken before and after surgery and at the last follow-up visit. SRS-22 at the final follow-up was obtained for clinical assessment. A total of 31 patients with a mean age of 14.6 years at operation who were followed for a mean of 6.4 years were included in this study. The Cobb angle of the unfused thoracic curve was spontaneously corrected immediately following SLF and increased slightly but not significantly at the final follow-up in both groups (Lenke 5C: pre 33.0°, post 14.4°, final 19.4°, Lenke 6C: pre 46.1°, post 31.7°, final 34.2°). At every time point, the thoracic Cobb angle was significantly larger in the Lenke 6C. SRS-22 score at the final follow-up, including the self-image domain, did not differ between the two groups. In this study, SLF for Lenke 6C AIS achieved a significant spontaneous correction of the unfused thoracic curve and yielded a comparable SRS-22 result at the final follow-up to that of Lenke 5C. Our findings suggest that SLF is a viable treatment option for Lenke 6C AIS.

2.
IEEE Trans Cybern ; PP2021 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-33750722

RESUMO

In this article, the problem of distributed synchronization of networked systems with actuator bias faults is investigated. To effectively use the limited network bandwidth and avoid the requirement of global information, a novel adaptive event-triggered state feedback controller and a dynamic triggering law are designed jointly by employing a projection operator approach. The proposed synchronization scheme is different from existing ones that have focused on designing controllers and triggering laws independently. Besides, our scheme is extended to design an observer-based distributed adaptive event-triggered controller and corresponding dynamic triggering law when the system states are unmeasurable. Theoretical analysis shows that under the two different distributed event-triggered synchronization schemes, the following three results can be obtained: 1) fully distributed synchronization can be achieved without knowing global information associated with the underlying communication topology and node's scale; 2) continuous communication among adjacent nodes can be avoided for both designed controllers and dynamic triggering laws; and 3) exclusion of Zeno phenomenon is shown by contradiction. Finally, the effectiveness of the proposed algorithms is verified through three numerical examples.

3.
Phys Chem Chem Phys ; 23(5): 3637-3645, 2021 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-33524094

RESUMO

Due to their broken out-of-plane inversion symmetry, Janus two-dimensional (2D) materials exhibit some exceptional and interesting physical properties and have recently attracted increasing attention. Herein, based on first-principles calculations, we propose a series of Janus 2D titanium nitride halide TiNX0.5Y0.5 (X, Y = F, Cl, or Br, and X ≠ Y) monolayers constructed from 2D ternary compounds TiNX (X = F, Cl, or Br), where the halogen atoms X or Y are located on each side of the monolayer, respectively. Our calculations confirm that the Janus monolayers are both dynamically and thermally stable. As compared with those of perfect TiNX monolayers, the band-structure changes of Janus TiNX0.5Y0.5 monolayers are very limited and the corresponding bandgaps only increase by about 0.1-0.2 eV. Meanwhile, the Janus TiNX0.5Y0.5 monolayers show remarkable out-of-plane piezoelectricity by virtue of their broken centrosymmetry. The calculated out-of-plane piezoelectric coefficient d31 is as high as 0.34 pm V-1, which is larger than those of most 2D piezoelectric materials reported previously. In addition, it is found that the formation of Janus structures could effectively improve the carrier mobility. The hole mobilities along the x-direction (y-direction) of Janus TiNF0.5Cl0.5 and TiNF0.5Br0.5 monolayers reach as high as 5402 (5118) and 5538 (4135) cm2 V-1 s-1 at 300 K, respectively, which is almost twice as large as those of perfect TiNX monolayers. The giant out-of-plane piezoelectricity and high carrier mobility of Janus TiNX0.5Y0.5 monolayers suggest that these novel 2D materials could be promising for applications in electronic and piezoelectric devices.

4.
IEEE Trans Cybern ; PP2021 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-33606651

RESUMO

This article analyzes the problem of the sliding-mode control (SMC) design for discrete-time piecewise nonhomogeneous Markov jump nonlinear systems (MJNSs) subject to an external disturbance with time-varying transition probabilities (TPs). A discrete-time asynchronous integral sliding surface is constructed, which yields matched-nonlinearity-free sliding-mode dynamics (SMDs). Then, by using the mode-dependent Lyapunov function technique, a sufficient condition is established for ensuring the stochastic stability of SMD with extended dissipation. The solution to designing controller gains is obtained. Moreover, an SMC law and an adaptive law are, respectively, derived for driving the system trajectories to move into a predetermined sliding-mode region with specified precision. Finally, the feasibility and effectiveness of the new design are verified and demonstrated by a simulation example.

5.
Dalton Trans ; 50(11): 3887-3893, 2021 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-33634813

RESUMO

At present, cyclometalated iridium (Ir)(iii) complexes are the most promising emitters for OLEDs. Contrary to well-developed Ir(iii)-based red and green phosphorescent complexes, the efficient blue emitters are limited and the performances of blue OLEDs are still not satisfactory. Inspired by this, we designed two novel blue Ir(iii) complexes employing 2-(2,4-difluoropyridyl)pyridine (dfpypy) and 2,6-difluoro-3-(pyridin-2-yl)benzonitrile (FCN) as the main ligands, respectively, and phenyl(pyridin-2-yl)phosphinate (ppp) as the ancillary ligand. The rational design of the molecular structure makes the two complexes achieve blue emission and possess good electron mobility simultaneously. The devices based on the Ir(iii) phosphors exhibited good electroluminescence performances with low turn-on voltages, a peak current efficiency of 24.51 cd A-1, a maximum external quantum efficiency of 12.4%, a peak power efficiency of 21.99 lm W-1 and low efficiency roll-off. These results provide an effective strategy for the future molecular design of blue Ir(iii) complexes with good electron transport property for OLEDs.

6.
Artigo em Inglês | MEDLINE | ID: mdl-33577457

RESUMO

The problem of finite-time adaptive tracking control against event-trigger error is investigated in this article for a type of uncertain nonlinear systems. By fusing the techniques of command filter backstepping technical and event-triggered control (ETC), an adaptive event-triggered design method is proposed to construct the controller, under which the effect of event-triggered error can be compensated completely. Moreover, the proposed controller can increase robustness against uncertainties and event error in the backstepping design framework. In particular, we establish the finite-time convergence condition under which the tracking error asymptotically converges to zero in finite time with the aid of a scaling function. Detailed and rigorous stability proofs are given by making use of the improved finite time stability criterion. Two simulation examples are provided to exhibit the validity of the designed adaptive ETC approach.

7.
IEEE Trans Cybern ; PP2021 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-33417583

RESUMO

This article studies the problem of dissipativity-based asynchronous state estimation for a class of discrete-time Markov jump neural networks subject to randomly occurring nonlinearities, sensor saturations, and stochastic parameter uncertainties. First, two stochastic nonlinearities occurring in the system are described by statistical means and obey two Bernoulli processes independently. Then, the hidden Markov model is used to characterize the real communication environment closely between the designed estimator and the system model due to the networked-induced phenomenons that also lead to randomly occurring parametric uncertainties of the estimator considered modeled by two Bernoulli processes. A new criterion is established to guarantee that the resulting error system is stochastically stable with predefined dissipativity performance. Finally, we provide a simulation example to validate the theoretical analysis.

8.
BMC Plant Biol ; 20(1): 553, 2020 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-33297963

RESUMO

BACKGROUND: Pentatricopeptide repeat (PPR) proteins compose a large protein family whose members are involved in both RNA processing in organelles and plant growth. Previous reports have shown that E-subgroup PPR proteins are involved in RNA editing. However, the additional functions and roles of the E-subgroup PPR proteins are unknown. RESULTS: In this study, we developed and identified a new maize kernel mutant with arrested embryo and endosperm development, i.e., defective kernel (dek) 55 (dek55). Genetic and molecular evidence suggested that the defective kernels resulted from a mononucleotide alteration (C to T) at + 449 bp within the open reading frame (ORF) of Zm00001d014471 (hereafter referred to as DEK55). DEK55 encodes an E-subgroup PPR protein within the mitochondria. Molecular analyses showed that the editing percentage of 24 RNA editing sites decreased and that of seven RNA editing sites increased in dek55 kernels, the sites of which were distributed across 14 mitochondrial gene transcripts. Moreover, the splicing efficiency of nad1 introns 1 and 4 and nad4 intron 1 significantly decreased in dek55 compared with the wild type (WT). These results indicate that DEK55 plays a crucial role in RNA editing at multiple sites as well as in the splicing of nad1 and nad4 introns. Mutation in the DEK55 gene led to the dysfunction of mitochondrial complex I. Moreover, yeast two-hybrid assays showed that DEK55 interacts with two multiple organellar RNA-editing factors (MORFs), i.e., ZmMORF1 (Zm00001d049043) and ZmMORF8 (Zm00001d048291). CONCLUSIONS: Our results demonstrated that a mutation in the DEK55 gene affects the mitochondrial function essential for maize kernel development. Our results also provide novel insight into the molecular functions of E-subgroup PPR proteins involved in plant organellar RNA processing.

9.
Phys Chem Chem Phys ; 22(46): 27441-27449, 2020 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-33232408

RESUMO

Low-dimensional materials have aroused widespread interest for their novel and fascinating properties. Based on first-principles calculations, we predict the one-dimensional (1D) InSeI nanochains with van der Waals (vdW) interchain interactions, which could be exfoliated mechanically and kept at steady states at room temperature. Compared with bulk InSeI, the single nanochain InSeI has a larger direct bandgap of 3.15 eV. Its calculated carrier mobility is as high as 54.17 and 27.49 cm2 V-1 s-1 for holes and electrons, respectively, comparable with those of other 1D materials. In addition, a direct-to-indirect bandgap transition is implemented under a small applied strain (∼6%). More importantly, the nanochains are found to be promising candidates for optoelectronic devices since they possess a high absorption coefficient of ∼105 cm-1 in the ultraviolet region. The results thus pave a novel avenue for the applications of InSeI nanochains with excellent thermal stability in nanoelectronic and optoelectronic devices.

10.
IEEE Trans Cybern ; PP2020 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-33170795

RESUMO

This article, based on dissipativity theory, aims to tackle the consensus tracking issue for Lipschitz nonlinear singular multiagent systems (MASs) with switching topologies and communication delays. Rooted at the leader node, a directed spanning tree is assumed to be contained in the union of all possible interaction graphs. Within the framework of topology switching controlled by a Markov chain, communication delays encountered in the data transmission process are reasonably considered to be time-varying and dependent on Markovian jump modes. By using tools from the stochastic Lyapunov functional technique, algebraic graph theory, and strict (Q,S,R)-α-dissipativity analysis, the consensus controller collecting delayed in-neighboring agents' information is designed to ensure stochastic admissibility and strict dissipativity of the resulting consensus error system. The theoretical analysis is validated by numerical simulations.

11.
Dis Model Mech ; 2020 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-33033107

RESUMO

Improving revascularization is one of the major measures in fracture treatment. Moderate local inflammation triggers angiogenesis, whereas systemic inflammation hampers angiogenesis. Previous studies showed that Akkermansia muciniphila (A. muc), a gut probiotic, ameliorates systemic inflammation by tightening intestinal barrier. In this study, fractured mice intragastrically administrated with A. muc were found to display better fracture healing than mice treated with vehicle. Notably, more preosteclasts positive for platelet-derived growth factor-BB (PDGF-BB) were induced by A. muc at 2 weeks post fracture, coinciding with increased formation of type H vessels, a specific vessel subtype that couples angiogenesis and osteogenesis and can be stimulated by PDGF-BB. Moreover, A. muc treatment significantly reduced gut permeability and inflammation at early stage. Dextran Sulfate Sodium (DSS) was used to disrupt the gut barrier to determine the role of gut barrier in fracture healing and whether A. muc still can stimulate bone fracture healing. As expected, A. muc evidently improved gut barrier, reduced inflammation, and restored the impaired bone healing and angiogenesis in DSS-treated mice. Our results suggest that A. muc reduces intestinal permeability and alleviates inflammation, which probably induces more PDGF-BB positive preosteoclasts and type H vessel formation in callus, thereby promoting fracture healing. This study provides the evidences about the involvement of type H vessels in fracture healing and suggests the potential of A. muc as a promising strategy for bone healing.

12.
J Am Chem Soc ; 142(41): 17756-17765, 2020 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-33021373

RESUMO

This work describes a strategy to produce circularly polarized thermally activated delayed fluorescence (CP-TADF). A set of two structurally similar organic emitters SFST and SFOT are constructed, whose spiro architectures containing asymmetric donors result in chirality. Upon grafting within the spiro frameworks, the donor and acceptor are fixed proximally in a face-to-face manner. This orientation allows intramolecular through-space charge transfer (TSCT) to occur in both emitters, leading to TADF properties. The donor units in SFST and SFOT have a sulfur and oxygen atom, respectively; such a subtle difference has great impacts on their photophysical, chiroptical, and electroluminescence (EL) properties. SFOT exhibits greatly enhanced EL performance in doped organic light-emitting diodes, with external quantum efficiency (EQE) up to 23.1%, owing to the concurrent manipulation of highly photoluminescent quantum efficiency (PLQY, ∼90%) and high exciton utilization. As a comparison, the relatively larger sulfur atom in SFST introduces heavy atom effects and leads to distortion of the molecular backbone that lengthens the donor-acceptor distance. SFST thus has lower PLQY and faster nonradiative decay rate. The collective consequence is that the EQE value of SFST, i.e., 12.5%, is much lower than that of SFOT. The chirality of these two spiro emitters results in circularly polarized luminescence. Because SFST has a more distorted molecular architecture than SFOT, the luminescence dissymmetry factor (|glum|) of circularly polarized luminescence of one enantiomer of the former, namely, either (S)-SFST or (R)-SFST, is almost twice that of (S)-SFOT/(R)-SFOT. Moreover, the CP organic light-emitting diodes (CP-OLEDs) show obvious circularly polarized electroluminescence (CPEL) signals with gEL of 1.30 × 10-3 and 1.0 × 10-3 for (S)-SFST and (S)-SFOT, respectively.

13.
IEEE Trans Cybern ; PP2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-33055052

RESUMO

Using semitensor products (STPs) of matrices, sampled-data state-feedback control (SDSFC) with the Lebesgue sampling region Sτ is first considered to stabilize a Boolean control network (BCN) to a fixed point, under which a necessary and sufficient condition for stabilization is obtained when the considered BCN with the Lebesgue sampling region is converted to a switching system. Meanwhile, the corresponding asynchronous SDSFC gains are designed from a sequence of reachable sets. Then, an algorithm is shown to obtain the minimal number of controlling times and all states globally stabilize to the desired state with the fastest convergence rate under the minimal number of controlling times. Besides, the results have been extended to p Lebesgue sampling regions Sτi, i=1,2,..., p. And some results are presented for this situation, including the necessary and sufficient conditions stabilization under the p Lebesgue sampling regions, the asynchronous SDSFC gains, and the algorithm to obtain the optimal states sampling regions. Examples are listed to show the effectiveness of our results, and the biological example indicates that the SDSFC with Lebesgue sampling is also suitable for stochastic BCNs.

14.
IEEE Trans Cybern ; PP2020 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-33095724

RESUMO

This article is concerned with the robust adaptive fault-tolerant control (FTC) circuit designs for a class of continuous-time disturbed systems. A circuit realization method is investigated to convert the robust adaptive FTC control schemes into analog control circuits. An adaptive compensation control scheme against state-dependent and partially bounded actuator faults and disturbances is first developed to demonstrate the approach clearly, then its equivalent control circuits are implemented by using the circuit theory. Compared with simulation results achieved by MATLAB and professional circuit simulation software, the effectiveness of the proposed robust adaptive FTC circuits is validated by a rocket fairing system and a Chua's circuit system.

15.
IEEE Trans Cybern ; PP2020 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-32991298

RESUMO

This article is concerned with the event-triggered output consensus problem for heterogeneous multiagent systems (MASs) with nonuniform communication delays. Unlike the existing event-triggered consensus results, more general heterogeneous linear MASs and nonuniform communication delays are considered. To reduce communication among subsystems, novel dynamic periodic event-triggered mechanisms are proposed. By using the event-triggered signals at the previous sampling instant, new distributed observers are designed to eliminate asynchronous behavior caused by nonuniform communication delays. Based on the developed observers, the observer error system is converted into a time-delay system with interval time-varying delays. Besides, a controller is designed by using the states of observers. It is shown that the consensus problem can be solved by the proposed method. Finally, an illustrative example is provided to verify the effectiveness of the developed method.

16.
Artigo em Inglês | MEDLINE | ID: mdl-32881691

RESUMO

This article concentrates on dealing with distributed control problems for second-order signed networks subject to not only cooperative but also antagonistic interactions. A distributed control protocol is proposed based on the nearest neighbor rules, with which necessary and sufficient conditions are developed for consensus of second-order signed networks whose communication topologies are described by strongly connected signed digraphs. Besides, another distributed control protocol in the presence of a communication delay is designed, for which a time margin of the delay can be determined simultaneously. It is shown that under the delay margin condition, necessary and sufficient consensus results can be derived even though second-order signed networks with a communication delay are considered. Simulation examples are included to illustrate the validity of our established consensus results of second-order signed networks.

17.
Adv Sci (Weinh) ; 7(15): 2000804, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32775163

RESUMO

To boost intrinsic circularly polarized luminescence (CPL) properties of chiral emitters, an axially chiral biphenyl unit is inlaid in thermally activated delayed fluorescent (TADF) skeleton, urging the participation of chiral source in frontier molecular orbital distributions. A pair of enantiomers, (R)-BPPOACZ and (S)-BPPOACZ, containing the cyano as electron-withdrawing moieties and carbazole and phenoxazine as electron-donating units are synthesized and separated. The circularly polarized TADF enantiomers exhibit both high photoluminescence quantum yield of 86.10% and excellent CPL activities with maximum dissymmetry factor |g PL| values of almost 10-2 in solution and 1.8 × 10-2 in doped film, which are among the best values of previously reported small chiral organic materials. Moreover, the circularly polarized organic light-emitting diodes based on the TADF enantiomers achieve the maximum external quantum efficiency of 16.6% with extremely low efficiency roll-off. Obvious circularly polarized electroluminescence signals with |g EL| values of 4 × 10-3 are also recorded.

18.
Int J Clin Exp Pathol ; 13(7): 1880-1885, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32782718

RESUMO

BACKGROUND: To analyze the clinical and molecular characteristics, as well as pathologic diagnosis and treatment of lung tumors that spread to the breast in 22 Chinese patients. MATERIALS AND METHODS: A systematic literature search of PubMed, Embase, ScienceDirect, Chinese National Knowledge Infrastructure (CNKI), Chinese Science and Technology Journal Database and Wanfang Databases was conducted to identify the related studies published before March 31, 2020. A case of a 64-year-old man who underwent pneumonectomy and who was eventually diagnosed with a breast lump 5 years after surgery at our hospital, was also included in the present study. We analyzed the clinical and immunohistochemical characteristics from these case reports. RESULTS: The analysis totally incorporates 21 case reports and our own case, covering 22 subjects. Among all cases we found 11 adenocarcinomas, 7 small-cell carcinomas, and 4 squamous carcinomas. In addition, most of metastatic breast masses were located below or near the nipple, rather than in the outer quadrant. The results of immunohistochemistry mostly showed triple negative breast cancers. CONCLUSION: A lung cancer patient with a breast tumor should suggest the possibility of metastasis. It is extremely difficult to distinguish secondary breast cancer from primary simply through medical observation and pathologic testing. Additional immunohistochemical examinations are necessary to avoid delays in diagnosis and treatment.

19.
IEEE Trans Cybern ; PP2020 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-32809949

RESUMO

This article addresses the adaptive neural tracking control problem for a class of uncertain stochastic nonlinear systems with nonstrict-feedback form and prespecified tracking accuracy. Some radial basis function neural networks (RBF NNs) are used to approximate the unknown continuous functions online, and the desired controller is designed via the adaptive dynamic surface control (DSC) method and the gain suppressing inequality technique. Different from the reported works on uncertain stochastic systems, by combining some non-negative switching functions and dynamic surface method with the nonlinear filter, the design difficulty is overcome, and the control performance is analyzed by employing stochastic Barbalat's lemma. Under the constructed controller, the tracking error converges to the accuracy defined a priori in probability. The simulation results are shown to verify the availability of the presented control scheme.

20.
Infect Drug Resist ; 13: 2161-2170, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32753912

RESUMO

Purpose: Our study is a retrospective observational study conducted in one of the largest clinical centers of neurosurgery in China. We aimed to investigate the antimicrobial susceptibility patterns of the Enterobacteriaceae isolates responsible for nosocomial meningitis/encephalitis in post-neurosurgical patients. Meanwhile, we tried to evaluate the risk factors for mortality following Enterobacteriaceae meningitis/encephalitis. Patients and Methods: Medical data on clinical characteristics, antibiotic susceptibilities, and mortality were reviewed until patients' discharge or death in the hospital. Data for a total of 164 cerebrospinal fluid (CSF) infection cases due to Enterobacteriaceae after neurosurgery were collected between January 2014 and November 2019 in order to identify risk factors affecting the outcome. Kaplan-Meier survival analysis and multivariable Cox proportional hazard models were applied. Results: In this study, a total of 2416 neurosurgical meningitis/encephalitis cases were reported between 2014 and 2019. Enterobacteriaceae accounted for 7.3% (176/2416) of all the bacterial infections. Of them, 164 Enterobacteriaceae isolates were available to divide into two groups according to the final outcome of whether the patient died or survived. In total, 38 patients died (23.2%) and 126 patients survived (76.8%). The most frequent infecting species was Klebsiella pneumoniae (47.0%, 77/164). Fourteen-day and 30-day mortality rates were 7.9% (13/164) and 15.2% (25/164). Kaplan-Meier survival analysis revealed that the risk factors of Enterobacteriaceae meningitis/encephalitis that resulted in poor outcomes included comorbidities, Glasgow Coma Scale (GCS) score, sepsis, intensive care unit (ICU) admission, extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae, and ventilation. A GCS score of less than or equal to 8 (P=0.04, HR 2.562) was identified to be a significant risk factor for mortality according to the multivariable Cox proportional hazards model. Conclusion: In-hospital mortality caused by Enterobacteriaceae meningitis/encephalitis in neurosurgery was high. A GCS score of ≤8 was an independent risk factor for mortality following Enterobacteriaceae meningitis/encephalitis in post-neurosurgical patients.

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