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关键词： anxiety   brain development   brain networks   endocannabinoid signaling   functional connectivity  

摘要： The endocannabinoid system is an important regulator of emotional responses such as fear, and a number of studies have implicated endocannabinoid signaling in anxiety. The fatty acid amide hydrolase (FAAH) C385A polymorphism, which is associated with enhanced endocannabinoid signaling in the brain, has been identified across species as a potential protective factor from anxiety. In particular, adults with the variant FAAH 385A allele have greater fronto-amygdala connectivity and lower anxiety symptoms. Whether broader network-level differences in connectivity exist, and when during development this neural phenotype emerges, remains unknown and represents an important next step in understanding how the FAAH C385A polymorphism impacts neurodevelopment and risk for anxiety disorders. Here, we leveraged data from 3,109 participants in the nationwide Adolescent Brain Cognitive Development Study(SM) (10.04 +/- 0.62 years old;44.23% female, 55.77% male) and a cross-validated, data-driven approach to examine associations between genetic variation and large-scale resting-state brain networks. Our findings revealed a distributed brain network, comprising functional connections that were both significantly greater (95% CI for p values = [<0.001, <0.001]) and lesser (95% CI for p values = [0.006, <0.001]) in A-allele carriers relative to non-carriers. Furthermore, there was a significant interaction between genotype and the summarized connectivity of functional connections that were greater in A-allele carriers, such that non-carriers with connectivity more similar to A-allele carriers (i.e., greater connectivity) had lower anxiety symptoms (beta = -0.041, p = 0.030). These findings provide novel evidence of network-level changes in neural connectivity associated with genetic variation in endocannabinoid signaling and suggest that genotype-associated neural differences may emerge at a younger age than genotype-associated differences in anxiety.

关键词： convex variational techniques   Girsanov's theorem   partial information   risk-sensitive optimal control   stochastic maximum principle  

摘要： This paper deals with a partially observed risk-sensitive optimal control problem described by mean-field forward-backward stochastic differential equations and the cost functional is a mean-field exponential of integral type. By using Girsanov's theorem as well as classical convex variational techniques, we obtain two risk-sensitive maximum principles, which are characterized in terms of the variational inequalities. Moreover, under certain concavity assumption, we give the sufficient condition for the optimality. Through the application of results, we consider the linear-quadratic risk-sensitive optimal control problem under partially observed information and fully observed information, respectively.

关键词： Particle swarm optimization   Differential evolution   Swarm intelligence   Evolutionary computation   Applications   COVID-19  

摘要： COVID-19 disease, which highly affected global life in 2020, led to a rapid scientific response. Versatile optimization methods found their application in scientific studies related to COVID-19 pandemic. Differential Evolution (DE) and Particle Swarm Optimization (PSO) are two metaheuristics that for over two decades have been widely researched and used in various fields of science. In this paper a survey of DE and PSO applications for problems related with COVID-19 pandemic that were rapidly published in 2020 is presented from two different points of view: 1. practitioners seeking the appropriate method to solve particular problem, 2. experts in metaheuristics that are interested in methodological details, inter comparisons between different methods, and the ways for improvement. The effectiveness and popularity of DE and PSO is analyzed in the context of other metaheuristics used against COVID-19. It is found that in COVID-19 related studies: 1. DE and PSO are most frequently used for calibration of epidemiological models and image-based classification of patients or symptoms, but applications are versatile, even interconnecting the pandemic and humanities;2. reporting on DE or PSO methodological details is often scarce, and the choices made are not necessarily appropriate for the particular algorithm or problem;3. mainly the basic variants of DE and PSO that were proposed in the late XX century are applied, and research performed in recent two decades is rather ignored;4. the number of citations and the availability of codes in various programming languages seems to be the main factors for choosing metaheuristics that are finally used.

关键词： inflammatory lung lesion   FDG PET/CT   subcutaneous skin lesion   differential diagnosis  

摘要： We present a 37-year-old man with cough and progressive dyspnea for the past 3 years. According to inconclusive chest CT scan and lung biopsy histopathology findings, the patient referred for F-18-FDG PET/CT scan for further evaluation. Classic pulmonary manifestations of Langerhans cell histiocytosis were seen on CT images with intense FDG uptake on PET scan. Moreover, PET/CT revealed multiple hypermetabolic subcutaneous foci throughout his body. Finally, the patient was treated with corticosteroids. Follow-up chest CT images demonstrated improvement of lung lesions in accordance with improvement in the patient's symptoms. We are briefly discussing differential diagnoses in this patient.

关键词： Digital lowpass differentiator   Digital allpass filter   Equiripple method   Maximally flat method  

摘要： The paper investigates the design of infinite-impulse response lowpass differentiators based on second-order allpass filter application. Specifications of the lowpass differentiator are first transformed into specifications of an equivalent second-order allpass filter. Unknown allpass filter coefficients are then determined such that relative passband magnitude response error of the corresponding lowpass differentiator is either minimized in the Chebyshev sense or maximally flat about some frequency in the passband. The main advantage of the proposed differentiators is their low group delay, which makes them suitable for real-time applications. Furthermore, the proposed equiripple design method exhibits fast convergence, while the maximally flat method is characterized by the simple closed-form expressions for the allpass filter coefficients values. Proposed lowpass differentiators are also compared with some of the existing infinite-impulse response lowpass differentiators.

关键词： Endocannabinoid system (ECS)   Cannabinoid type-1 receptor (CB1)   Down syndrome (DS)   Ts65Dn mouse   Hippocampus (HPC)  

摘要： Down syndrome (DS) or Trisomy 21 is the most common genetic cause of mental retardation with severe learning and memory deficits. DS is due to the complete or partial triplication of human chromosome 21 (HSA21) triggering gene overexpression and protein synthesis alterations responsible for a plethora of mental and physical phenotypes. Among the diverse brain target systems that affect hippocampal-dependent learning and memory deficit impairments in DS, the upregulation of the endocannabinoid system (ECS), and notably the over expression of the cannabinoid type-1 receptor (CB1), seems to play a major role. Combining various protein and gene expression targeted approaches using western blot, qRT-PCR and FISH techniques, we investigated the expression pattern of ECS components in the hippocampus (HPC) of male Ts65Dn mice. Among all the molecules that constitute the ECS, we found that the expression of the CB1 is altered in the HPC of Ts65Dn mice. CB1 distribution is differentially segregated between the dorsal and ventral part of the HPC and within the different cell populations that compose the HPC. CB1 expression is upregulated in GABAergic neurons of Ts65Dn mice whereas it is downregulated in glutamatergic neurons. These results highlight a complex regulation of the CB1 encoding gene (Cnr1) in Ts65Dn mice that could open new therapeutic solutions for this syndrome.

摘要： Context.-Chordomas are uncommon malignant neoplasms with notochordal differentiation encountered by neuropathologists, bone/soft tissue pathologists, and general surgical pathologists. These lesions most commonly arise in the axial skeleton. Optimal therapy typically involves complete surgical resection, which is often technically difficult owing to the anatomic location, leading to a high rate of recurrence. Lesions have been generally resistant to radiation and chemotherapy;however, experimental studies involving targeted therapy and immunotherapy are currently underway. Objective.-To summarize the clinical and pathologic findings of the various types of chordoma (conventional chordoma, dedifferentiated chordoma, and poorly differentiated chordoma), the differential diagnosis, and recent advances in molecular pathogenesis and therapeutic modalities that are reliant on accurate diagnosis. Data Sources.-Literature review based on PubMed searches containing the term "chordoma"that address novel targeted and immunomodulatory therapeutic modalities;ongoing clinical trials involved in treating chordoma with novel therapeutic modalities identified through the Chordoma Foundation and ***;and the authors' practice experience combined with various authoritative texts concerning the subject. Conclusions.-Chordoma is a clinically and histologically unique malignant neoplasm, and numerous diagnostic considerations must be excluded to establish the correct diagnosis. Treatment options have largely been centered on surgical excision with marginal results;however, novel therapeutic options including targeted therapy and immunotherapy are promising means to improve prognosis.

关键词： modular flyback differential inverter (MFBDI)   continuous modulation scheme (CMS)   static linear strategy (SLS)   harmonic compensation strategy  

摘要： This paper proposes a single-stage three-phase modular flyback differential inverter (MFBDI) for medium/high power solar PV grid-integrated applications. The proposed inverter structure consists of parallel modules of flyback DC-DC converters based on the required power level. The MFBDI offers many features for renewable energy applications, such as reduced components, single-stage power processing, high-power density, voltage-boosting property, improved footprint, flexibility with modular extension capability, and galvanic isolation. The proposed inverter has been modelled, designed, and scaled up to the required application rating. A new mathematical model of the proposed MFBDI is presented and analyzed with a time-varying duty-cycle, wide-range of frequency variation, and power balancing in order to display its grid current harmonic orders for grid-tied applications. In addition, an LPF-based harmonic compensation strategy is used for second-order harmonic component (SOHC) compensation. With the help of the compensation technique, the grid current THD is reduced from 36% to 4.6% by diminishing the SOHC from 51% to 0.8%. Moreover, the SOHC compensation technique eliminates third-order harmonic components from the DC input current. In addition, a 15% parameters mismatch has been applied between the flyback parallel modules to confirm the modular operation of the proposed MFBDI under modules divergence. In addition, SiC MOSFETs are used for inverter switches implementation, which decrease the inverter switching losses at high-switching frequency. The proposed MFBDI is verified by using three flyback parallel modules/phase using PSIM/Simulink software, with a rating of 5 kW, 200 V, and 50 kHz switching frequency, as well as experimental environments.

关键词： Low-carbon steel sheet   Strength differential effect   Stack compression test   In-plane compression test   Equibiaxial tension test   Pressure coefficient  

摘要： The effect of hydrostatic stress on the strength differential effect (SDE) in a 0 8-mm-thick low-carbon steel sheet is experimentally investigated. The in-plane compressive stress-strain curve is approximately 10% higher than the uniaxial tensile stress-strain curve at a strain of 0.15, confirming that the test sample exhibited the SDE. A stack compression test in the thickness direction of the test sample is also performed. The measured through-thickness uniaxial compressive stress-strain curve is found to be higher than the equibiaxial tensile stress-thickness plastic strain curves measured using a cruciform equibiaxial tension test (ISO 16842) and a hydraulic bulge test (ISO 16808), indicating a positive correlation between hydrostatic pressure and flow stress. From these experiments, we conclude that the SDE in a low-carbon steel sheet is caused by the effect of hydrostatic pressure on flow stress. However, the pressure coefficient of the test sample, 50 - 150 TPa-1, is found to be significantly higher than those for high-strength steel alloys and Fe single crystals (13 - 23 TPa-1) reported by Richmond and Spitzig (1980).

关键词： Hadamard fractional calculus   Finite-time stability   Weighted Banach spaces   Beesack inequality   Delayed Mittag-Leffler matrix function  

摘要： The main purpose of this paper is to investigate the finite-time stability of Hadamard fractional differential equations (HFDEs). Firstly, the standard definitions of finite-time stability of HFDEs in compatible Banach spaces are proposed. In light of the method of successive approximation and Beesack inequality with weakly singular kernel, the criteria of finite-time stability for linear and nonlinear HFDEs are established, respectively. Then with regard to linear HFDEs with pure delay, a novel fractional delayed matrix function (also called delayed Mittag-Leffler matrix function) is given. Specific to nonlinear HFDEs with constant time delay, both Beesack inequality and Holder inequality are utilized in the framework of the generalized Lipschitz condition. Finally, several indispensable simulations are implemented to verify the effectiveness and practicability of the main results.