Summary
A wealth of epidemiological studies concerning the distribution of type 1 diabetes (T1D) around the world have pointed to the appreciable variation in the incidence of T1D among disparate age ...groups, ethnicities, and geographical locations. On the whole, the incidence of childhood T1D has been on the rise, and a plausible inverse relationship between the initial incidence rate and the following annual increase in incidence has been raised. Countries that used to exhibit lower incidences tend to have steep annual increase whereas those with already‐established high incidences are more likely to show a modest increase or even stabilization in T1D incidence. Environmental agents considered responsible for the current evolving pattern of T1D incidence will be detailed, mainly including the increasing prevalence of childhood obesity, viral infections in a chronic manner, maternal‐child interaction such as breastfeeding, and latitude‐ultraviolet B‐vitamin D pathway. Certain rationale has been put forward in an attempt to explain the potential association between environmental agents and development of T1D. For instance, accelerator hypothesis regards insulin resistance as the promoter of earlier disease onset in obese children whereas the negative correlation of microbial infections in background populations with incidence of T1D represents the basic component of the hygiene hypothesis. Further investigations are still warranted to verify these theories across multiple ethnic groups and to identify additional contributors to the variation in T1D incidence.
Convolutional neural networks (CNN) have been widely used in various fields and have played an impor-tant role. Convolution operator is the basic component of CNN, and it is also the most ...time-consuming part. In recent years, researchers have proposed several fast convolution algorithms including FFT and Winograd. Among them, Winograd convolution has quickly become the first choice for fast convolution implementation on convolu-tion operators with small convolution kernels, because it greatly reduces the multiplication operations in convolu-tion and occupies less memory. Related work focuses on the generalization, extension and implementation on various architectures of the Winograd convolution, but there are no researchers who have systematically summa-rized the Winograd convolution algorithm. This paper aims to provide detailed reference for follow-up researchers, and summarizes all related work since the introduction of Winograd convolution. Firstly, the introduction of Winograd minimum filtering algorithm
Spectral splitting is an approach to the design of hybrid photovoltaic-thermal (PVT) collectors that promises significant performance benefits. However, the ultimate efficiency limits, optimal PV ...cell materials and optical filters of spectral-splitting PVT (SSPVT) collectors remain unclear, with a lack of consensus in the literature. We develop an idealized model of SSPVT collectors and use this to determine their electrical and thermal efficiency limits, and to uncover how these limits can be approached through the selection of optimal PV cell materials and spectral-splitting filters. Assuming that thermal losses can be minimized, the efficiency limit, optimal PV material and optimal filter all depend strongly on a coefficient w, which quantifies the value of the delivered thermal energy relative to that of the generated electricity. The total (electrical plus thermal) efficiency limit of SSPVT collectors increases at higher w and at higher optical concentrations. The optimal spectral-splitting filter is defined by sharp lower- and upper-bound energies; the former always coincides with the bandgap of the cell, whereas the latter decreases at higher w. The total effective efficiency limit of SSPVT collectors is over 20% higher than those of either standalone PV modules or standalone ST collectors when w is in the range from 0.35 to 0.50 and up to 30% higher at w ≈ 0.4. This study provides a method for identifying the efficiency limits of ideal SSPVT collectors and reports these limits, along with guidance for selecting optimal PV materials and spectral-splitting filters under different conditions and in different applications.
Recently, it was shown that the highly variable after-effect of continuous theta-burst stimulation (cTBS) of the primary motor cortex (M1) can be predicted by the latency of motor-evoked potentials ...(MEPs) recorded before cTBS. This suggests that at least part of this inter-individual variability is driven by differences in the neuronal populations preferentially activated by transcranial magnetic stimulation (TMS).
Here, we recorded MEPs, TMS-evoked brain potentials (TEPs) and somatosensory-evoked potentials (SEPs) to investigate the effects of cTBS delivered over the primary sensorimotor cortex on both the ipsilateral and contralateral M1, and the ipsilateral and contralateral primary somatosensory cortex (S1).
We confirm that the after-effects of cTBS can be predicted by the latency of MEPs recorded before cTBS. Over the hemisphere onto which cTBS was delivered, short-latency MEPs at baseline were associated with an increase of MEP magnitude (i.e. an excitatory effect of cTBS) whereas late-latency MEPs were associated with reduced MEPs (i.e. an inhibitory effect of cTBS). This relationship was reversed over the contralateral hemisphere, indicating opposite effects of cTBS on the responsiveness of the ipsilateral and contralateral M1. Baseline MEP latencies also predicted changes in the magnitude of the N100 wave of TEPs elicited by stimulation of the ipsilateral and contralateral hemisphere, indicating that this TEP component is specifically dependent on the state of M1. Finally, there was a reverse relationship between MEP latency and the effects of cTBS on the SEP waveforms (50-130 ms), indicating that after-effects of cTBS on S1 are opposite to those on M1.
Taken together, our results confirm that the variable after-effects of cTBS can be explained by differences in the neuronal populations activated by TMS. Furthermore, our results show that this variability also determines remote effects of cTBS in S1 and the contralateral hemisphere, compatible with inter-hemispheric and sensorimotor interactions.
Most solar energy incident (>70%) upon commercial photovoltaic panels is dissipated as heat, increasing their operating temperature, and leading to significant deterioration in electrical ...performance. The solar utilisation efficiency of commercial photovoltaic panels is typically below 25%. Here, we demonstrate a hybrid multi-generation photovoltaic leaf concept that employs a biomimetic transpiration structure made of eco-friendly, low-cost and widely-available materials for effective passive thermal management and multi-generation. We demonstrate experimentally that bio-inspired transpiration can remove ~590 W/m
of heat from a photovoltaic cell, reducing the cell temperature by ~26 °C under an irradiance of 1000 W/m
, and resulting in a relatively 13.6% increase in electrical efficiency. Furthermore, the photovoltaic leaf is capable of synergistically utilising the recovered heat to co-generate additional thermal energy and freshwater simultaneously within the same component, significantly elevating the overall solar utilisation efficiency from 13.2% to over 74.5%, along with over 1.1 L/h/m
of clean water.
Hybrid photovoltaic-thermal (PV-T) collectors, which are capable of cogenerating useful thermal energy and electricity from the same aperture area, have a significantly higher overall efficiency and ...ability to displace emissions compared to independent, separate photovoltaic panels, solar thermal collectors or combinations thereof. Spectral splitting has emerged as a promising route towards next-generation high-performance PV-T collectors, and nanotechnology plays an important role in meeting the optical and thermal requirements of advanced spectral splitting PV-T collector designs. This paper presents a comprehensive review of spectral splitting technologies based on nanomaterials for PV-T applications. Emerging nanomaterials (nanofluids, nanofilms and nanowires) suitable for achieving spectral splitting based on reflection, diffraction, refraction and/or absorption approaches in PV-T collectors are presented, along with the associated challenges and opportunities of these design approaches. The requirements from such materials in terms of optical properties, thermal properties, stability and cost are discussed with the aim of guiding future research and innovation, and developing this technology towards practical application. Nanofluids and nanofilms are currently the most common nanomaterials used for spectral splitting, with significant progress made in recent years in the development of these materials. Nevertheless, there still remains a considerable gap between the optical properties of currently-available filters and the desired properties of ideal filters. Aiming to instruct and guide the future development of filter materials, a simple generalized method is further proposed in this paper to identify optimal filters and efficiency limits of spectral splitting PV-T systems for different scenarios. It is found that the optimal filter of a spectral splitting PV-T system is highly sensitive to the value of thermal energy relative to that of electricity, which therefore depends strongly on the application and location. The efficiency limit of spectral splitting PV-T collectors is significantly higher than that of standalone PV panels. The stability of nanomaterial filters remains a critical challenge for their long-term employment and also for high-temperature operation in practical applications.
Porous tantalum (Ta) is a promising biomaterial and has been applied in orthopedics and dentistry for nearly two decades. The high porosity and interconnected pore structure of porous Ta promise fine ...bone ingrowth and new bone formation within the inner space, which further guarantee rapid osteointegration and bone-implant stability in the long term. Porous Ta has high wettability and surface energy that can facilitate adherence, proliferation and mineralization of osteoblasts. Meanwhile, the low elastic modulus and high friction coefficient of porous Ta allow it to effectively avoid the stress shield effect, minimize marginal bone loss and ensure primary stability. Accordingly, the satisfactory clinical application of porous Ta-based implants or prostheses is mainly derived from its excellent biological and mechanical properties. With the advent of additive manufacturing, personalized porous Ta-based implants or prostheses have shown their clinical value in the treatment of individual patients who need specially designed implants or prosthesis. In addition, many modification methods have been introduced to enhance the bioactivity and antibacterial property of porous Ta with promising in vitro and in vivo research results. In any case, choosing suitable patients is of great importance to guarantee surgical success after porous Ta insertion.
A new type of observer is presented for a class of nonlinear time-delay systems in this paper. Different from the traditional observers, the design of new observers is based on the assumption that ...the output is measured intermittently. The methods of designing observers for systems with fast-varying state delay and slow-varying state delay are investigated, respectively, by constructing two novel time-varying switching Lyapunov function/functional combined with the convex combination technique. Some sufficient conditions are derived to guarantee the stability of the corresponding error systems, and the observers can be designed by solving a set of linear matrix inequalities. Finally, two numerical examples are provided to illustrate the effectiveness of the proposed methods.
•Mechanical model for the peeling behavior of a film with finite length perfectly bonded to an elastic substrate has been proposed.•The effects of root rotation, ratio between Young’s moduli of the ...film and the substrate, and film’s aspect ratio on peeling behavior have been demonstrated.•Empirical expression for estimating peeling force in relation to those parameters has been established.
A mechanical model for the peeling behavior of a film with finite length perfectly bonded to an elastic substrate has been proposed. The film has been considered as an elastic beam from which the root rotation at the boundary between the debonded and bonded portions can be obtained. Numerical results have demonstrated significant effects of the parameters including root rotation, ratio between Young’s moduli of the film and the substrate, and film’s aspect ratio on the stress intensity factors that were used to measure the interfacial tractions. Based on the numerical results, empirical expressions for the stress intensity factors have been presented. And hence expression for estimating peeling force in relation to those parameters has been established. The results in the present paper may be helpful for characterizing the peeling behavior of film-substrate systems.
Metronidazole (Met) is the first choice for treating Helicobacter pylori (Hp). However, Hp is easy to resistant, making Met unable to be widely used. How to overcome Hp’s Met resistance is still an ...issue. In this study, Met was used as the primary raw material with linolenic acid to prepare a novel compound-linolenic acid-metronidazole (Lla-Met). The MIC, minimum bactericidal concentration (MBC), colonization amount of Hp in gastric mucosa, etc., were evaluated, respectively. Lla-Met was successfully prepared by the detection of nuclear magnetic resonance, etc., and its MIC and MBC to Hp were 2~4 μg/mL, 8~16 μg/mL. Moreover, in vivo experiments, Lla-Met significantly reduced the colonization of drug-resistant Hp in gastric mucosa. In the toxicity test, Lla-Met inhibited rate to GES-1 and BGC823 cells were 15% at 128 μg/mL; the mice were administered 10 times treatment Lla-Met treatment (240 mg/kg), have no difference significant injuries were found in their stomach, liver, spleen, kidney, and weight. In addition, Hp G27 continued for 18 days in vitro with sub-Lla-Met concentration, G27 did not show drug resistance to Lla-Met; Lla-Met did not exert an effect on non-Hp species with 128 μg/mL; Compared with a neutral environment, when the acid concentration is 3.0, Lla-Met is not decomposed and has better stability. Conclusion: Lla-Met, a newly prepared compound, has relatively well antibacterial of Met-resistant and sensitive Hp, with a capability of overcoming the metronidazole resistance of Hp.
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