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Among the different nanostructures that have been demonstrated as promising materials for various applications, three–dimensional (3D) nanostructures have attracted significant attention as building blocks for constructing high-performance nanodevices because of their unusual mechanical, electrical, thermal, optical, and magnetic properties arising from their novel size effects and abundant active catalytic/reactive sites due to the high specific surface area. Considerable research efforts have been devoted to designing, fabricating, and evaluating 3D nanostructures for applications, including structural composites, electronics, photonics, biomedical engineering, and energy. This review provides an overview of the nanofabrication strategies that have been developed to fabricate 3D functional architectures with exquisite control over their morphology at the nanoscale. The pros and cons of the typical synthetic methods and experimental protocols are reviewed and outlined. Future challenges of fabrication of 3D nanostructured materials are also discussed to further advance current nanoscience and nanotechnology.

Acoustic/elastic metasurfaces as a kind of two-dimensional metamaterials are of subwavelength thickness and show remarkable ability of acoustic/elastic wave manipulation. They have potential applications in various fields such as acoustic imaging, communications, cloaking, camouflage, vibration/noise control, energy harvesting, and nondestructive testing. In this review, we mainly summarize recent developments in acoustic/elastic phase gradient metasurfaces, including design principles, design of functional elements, wave field manipulation with applications, design of tunable metasurfaces, as well as the emerging digital coding metasurfaces. At last, we outline the future research directions in this field.

Natural silk fiber derived from the Bombyx mori (B. mori) silkworm has long been used as a luxury raw material in textile industry because of its shimmering appearance and durability, and as surgical suture for its high strength and flexibility. Regenerated silk fibroin, as the main protein extracted from the cocoons of the B. mori silkworm, recently has gained considerable attention due to its outstanding properties, including facile processability, superior biocompatibility, controllable biodegradation, and versatile functionalization. Tremendous effort has been made to fabricate silk fibroin into various promising materials with controlled structural and functional characteristics for advanced utilities in a multitude of biomedical applications, flexible optics, electronics devices, and filtration systems. Herein, reverse engineered silk fibroin extraction methods are reviewed, recent advances in extraction techniques are discussed. Fabrication methods of silk fibroin materials in various formats are also addressed in detail; in particular, progress in new fabrication technologies is presented. Attractive applications of silk fibroin-based materials are then summarized and highlighted. The challenges faced by current approaches in production of silk fibroin-based materials and future directions acquired for pushing these favorable materials further toward above mentioned applications are further elaborated.

Seismic metamaterials (SMs) are expected to assist or replace traditional isolation systems owing to their strong attenuation of seismic waves. In this paper, a one-dimensional inverted T-shaped SM (1D ITSM) with an ultra-wide first bandgap (FBG) is proposed. The complex band structures are calculated to analyze the wave characteristics of the surface waves in the SMs. We find that the FBG of the 1D ITSM is composed of two parts; part 1 with surface evanescent waves and part 2 with no surface modes. Similar results are found in the complex band structure of the FBG of the SM consisting of periodically arranged pillars and substrate. The propagation of seismic surface waves in the 1D ITSM is different in these two frequency ranges of the FBG. In part 1, the seismic surface waves are significantly attenuated in the 1D ITSM, while in part 2, the surface waves are converted into bulk waves. Finally, the ultra-wide FBG is verified by using a kind of the two-dimensional ITSM in large-scale field experiments., 30 pages,15 figures

High-performance and lightweight waterborne acoustic devices have provided important support for the development of ocean exploration, health monitoring, etc. In this work, we propose a high-efficiency ultrathin nonlocal waterborne acoustic metasurface. Due to strong nonlocal interaction between the waterborne unit cells induced by the fluid-solid interaction, a nonlocal design concept based on diffraction theory and the optimization approach is proposed to design waterborne acoustic metasurfaces, in contrast to the local design based on the generalized Snell's law. The theoretical efficiency limitation of the generalized Snell's law can be broken, and unitary efficiency could be obtained even for large-angle anomalous reflection. The high-efficiency modulation is achieved owing to the energy flow along the metasurface resulting from the nonlocal interaction. The thickness of the waterborne acoustic metasurface can be minimized to one tenth or even one sixtieth of the working wavelength. The nonlocal design with fluid-solid interaction paves the way for high-efficiency and deep-subwavelength waterborne acoustic wave manipulation.

Acoustic metasurface carpet cloak has suffered from narrowband limitation due to highly frequency-dependent phase response. Here, we adopt two entirely different ways to broaden the working frequency range of the carpet cloak with dynamic or static metasurface structure. Numerical simulations and experimental measurements demonstrate that the designed dynamic or static metasurface carpet cloak can both exhibit a broadband stealth performance. The proposed design strategy is expected to break the narrowband limitation of metasurfaces, making a significant difference to the practical applications of the broadband acoustic devices.

International audience; Acoustic metasurfaces can reshape a reflected wavefront rather arbitrarily, despite being much thinner than the wavelength, thus allowing on-demand wavefront modulation in a variety of applications. Recent passive metasurfaces, however, have suffered from bandwidth limitations, thus restricting their range of operation. In this work, we propose the systematic design of ultra-broadband passive metasurfaces by combining the broadband local reflection rule with an optimization method. The validation of the technique is demonstrated by fabrication and measurement of an ultra-broadband carpet cloak. Numerical and experimental results show that the relative bandwidth of the optimized carpet cloak, thinner than one fifth of the maximum wavelength, can exceed 93.33%, a value that is much larger than that of previous passive metasurfaces. Furthermore, multi-frequency pulse incidence tests reveal the excellent time-domain broadband characteristics of the metasurface over a wide range of angles of incidence. The proposed strategy opens a new route for the design of advanced passive metasurfaces for ultra-broadband wave manipulation and thus promotes practical applications of broadband acoustical devices.

OBJECTIVE: To study the application value of surface electromyography in children with dysphagia. METHODS: A total of 20 children with dysphagia were enrolled as the observation group, and 20 healthy children, matched for sex and age, were enrolled as the control group. Surface electromyography was used to record the electromyography integral values of the submental and infrahyoid muscle groups in the resting state and the state after water swallowing. The two groups were compared in terms of the electromyography integral values of the submental and infrahyoid muscle groups in the resting state and the state after swallowing 5 mL water. The observation group was observed in terms of the changes in the electromyography integral values of the submental and infrahyoid muscle groups after 1 month of rehabilitation treatment. A Spearman correlation analysis was used to evaluate the correlation of the degree of dysphagia with the electromyography integral values of the submental and infrahyoid muscle groups in the observation group. RESULTS: There was no significant difference between the two groups in the electromyography integral values of the submental and infrahyoid muscle groups in the resting state (P > 0.05), while after water swallowing, the observation group had significantly higher electromyography integral values than the control group (P < 0.05). The observation group had significant improvements in the clinical symptoms of dysphagia after treatment, with significant reductions in the electromyography integral values of the submental and infrahyoid muscle groups (P < 0.05). The severity of dysphagia was positively correlated with the electromyography integral values of the submental and infrahyoid muscle groups (P < 0.01). CONCLUSIONS: Surface electromyography is useful in the diagnosis and therapeutic effect evaluation for dysphagia in children.

Self-accelerating beams have applications in optic and acoustic fields due to their peculiar properties. As a promising artificial two-dimensional metamaterial, a metasurface can be used as the generator of self-accelerating beams. However, restricted by the generalized Snell's law, most research hotspots focus on flat metasurfaces. In this Letter, the generalized Snell's law on an arbitrary curved reflective surface is discussed. Then, the phase profile for the self-accelerating beams generated from the curved reflective surface is derived based on the caustic theory. The metasurface consisting of the tunable spiral path units is constructed, and numerical and experimental validations are performed. The methodology developed in the present letter extends the applications of the self-accelerating beams.

In this paper, a tunable arc-shaped acoustic metasurface (AAM) carpet cloak has been proposed and systematically investigated. The AAM carpet cloak consists of covers, rotors, bolts and nuts. The rotors can be rotated continuously within the covers to form a reconfigurable hook channel mechanism. By setting various rotational angles, we construct two-dimensional (2D) tunable AAM carpet cloaks to achieve excellent stealth performances under different operating conditions. Numerical simulations and experimental results for the 2D carpet cloaks show good agreements. Furthermore, simulated results for three-dimensional (3D) carpet cloaks have demonstrated that tapered objects are successfully escaping from being detected. The tunable hook channel mechanism can be flexibly applied to arbitrarily curved metasurface carpet cloaks, making them closer to practical invisibility acoustic devices.

Summary Objective To clarify whether exanthema is related to illness severity in acute enterovirus infection in children. Methods The data of pediatric inpatients at Zhujiang Hospital during 2009–2012 with an acute enterovirus infection were reviewed retrospectively. Enterovirus infection was determined by real-time reverse transcription PCR. Clinical data were summarized and compared between cases with and without exanthema. Results A total of 780 pediatric inpatients with an acute enterovirus infection were included in this study, of whom 83 (10.6%) presented no exanthema. The percentage of deaths in the group of patients without exanthema was significantly higher than that in the group with exanthema (7.2% vs. 1.1%; p = 0.002). Central nervous system involvement (41.0% vs. 30.0%; p = 0.041), severe central nervous system (CNS) involvement (21.7% vs. 11.0%; p = 0.005), severe CNS involvement with cardiopulmonary failure (9.6% vs. 2.3%; p = 0.002), an altered level of consciousness (15.7% vs. 7.6%; p = 0.013), and convulsions (14.4% vs. 6.3%; p = 0.007) occurred significantly more frequently in the group without exanthema. Conclusions A considerable proportion of children with an acute enterovirus infection in Guangdong Province, China during 2009–2012 presented no exanthema, and the absence of exanthema was found to be related to death and illness severity for these acute enterovirus infections. Clinicians in China should consider enterovirus as the possible pathogen when treating children with an acute pathogen infection without exanthema.

Background Enterovirus (EV)-related hand, foot, and mouth disease/herpangina (HFMD/HA) has been prevalent in Guangdong Province, China, since 2010. Methods Clinical data for EV-related HFMD/HA inpatients admitted to the Department of Paediatrics of Zhujiang Hospital from 2010 to 2013 were retrospectively reviewed. The corresponding EV serotypes were also determined by reverse transcription-polymerase chain reaction or BLAST analysis of the sequenced partial lengths of the viral protein1/5′-untranslated region. Results A total of 867 eligible inpatients admitted during 2010–2013 were included in the study. Of these, the serotype of the responsible EV was successfully identified in 824 cases. The incidence of enterovirus 71 (EV71) infection amongst pediatric HFMD/HA inpatients decreased dramatically from 55.5 % in 2010 to 8.1 % in 2013, with a similar decrease recorded for coxsackievirus A16 (CVA16). However, the incidence of non-EV71/CVA16 infection increased from 30.0 % in 2010 to 83.8 % in 2013. We noted that the types of infection caused by different EV serotypes varied: EV71 was responsible for 100 % of the paralysis cases (26/26), 84.6 % of the deaths (11/13), and 84.1 % of cases with severe central nervous system involvement (SCNSI) (74/88); echovirus contributed to 16.4 % of the deaths (2/13) and 4.4 % of the SCNSI cases; and coxsackievirus accounted for only 2.2 % of the SCNSI cases (2/90). The clinical features of HFMD/HA cases varied greatly during the time period examined, with drastic changes in the hospitalization rates (45.1, 63.7, 36.4, and 19.1 % for 2010, 2011, 2012, and 21013, respectively), mortality rates (2.3, 0.9, 2.5, and 0.0 %, respectively), paralysis (5.1, 1.2, 5.4, and 0.0 %, respectively), SCNSI (16.8, 7.1, 12.7, and 2.2 %, respectively), and acute respiratory infection (21.1, 22.0, 45.9, and 59.0 %, respectively). Conclusions The incidences of infection caused by different EV serotypes, along with the clinical features of HFMD/HA cases, changed drastically in Guangdong Province, China, from 2010 to 2013, with the biggest changes observed in 2013. The changed constituent ratios of the different EV serotypes might therefore be responsible for the differences in the observed clinical features of HFMD/HA during this period. Electronic supplementary material The online version of this article (doi:10.1186/s12879-016-1690-0) contains supplementary material, which is available to authorized users.

The proliferation of cardiac fibroblasts (CFs) and excessive deposition of extracellular matrix are the predominant pathological characteristics of cardiac fibrosis. As the largest member of the nucleotide‑binding domain and leucine‑rich repeat (NLR) family, NLRC5 has been shown to be pivotal in the development of hepatic fibrosis. However, whether NLRC5 is involved in the pathogenesis of cardiac fibrosis remains to be elucidated. The present study aimed to investigate the role of NLRC5 and its mechanisms in regulating cardiac fibrosis. CFs were stimulated with transforming growth factor (TGF)‑β1 for various times and the mRNA and protein expression of NLRC5 was assessed using reverse transcription‑quantitative polymerase chain reaction and western blot analysis, respectively. In addition, CFs were transfected with small interfering (si)RNA targeting NLRC5 or scramble siRNA for 24 h and then stimulated with TGF‑β1 for 24 h. Subsequently, cell proliferation was measured using an MTT assay, whereas cell migration was evaluated using a Transwell migration assay. The protein expression levels of α‑smooth muscle actin, collagen I, connective tissue growth factor, phosphorylated‑Smad3 and Smad3 were measured using western blot analysis. The results demonstrated that NLRC5 was upregulated in TGF‑β1‑induced CFs. The knockdown of NLRC5 significantly inhibited cell proliferation and migration, and suppressed myofibroblast differentiation and the expression of pro‑fibrotic molecules in TGF‑β1‑treated CFs. Furthermore, the knockdown of NLRC5 attenuated TGF‑β1‑induced phosphorylation of small mothers against decapentaplegic (Smad)3 in the CFs. The results of the present study indicated that NLRC5 acted as a key regulator of pathological cardiac fibrosis, and NLRC5 silencing ameliorated cardiac fibrosis by inhibiting the TGF‑β1/Smad3 signaling pathway. These results suggested that NLRC5 may be a novel target for attenuating cardiac fibrosis.

The proliferation of cardiac fibroblasts (CFs) and deposition of extracellular matrix (ECM) proteins are pivotal in the development of cardiac fibrosis. Recent studies have indicated that diosgenin may inhibit high glucose‑induced renal tubular fibrosis; however, to the best of our knowledge, no studies have focused on the effects of diosgenin on cardiac fibrosis. Therefore, the present study aimed to explore the effects of diosgenin on angiotensin II (Ang II)‑induced ECM remodeling, and its possible mechanism in rat CFs. CFs were pre‑incubated with diosgenin (1, 5 and 10 µM) for 24 h and were then stimulated with Ang II (100 nM) for 24 h. Cell proliferation was estimated using the MTS assay. The expression levels of α‑SMA, fibronectin, collagen I, TGF‑β1, in addition to phosphorylation of Smad3 were detected by western blotting. The results demonstrated that diosgenin inhibited Ang II‑induced CF proliferation and the differentiation of CFs to myofibroblasts. In addition, diosgenin was able to inhibit Ang II‑induced ECM expression in rat CFs. Furthermore, diosgenin inhibited Ang II‑induced expression of transforming growth factor‑β1 (TGF‑β1) and Smad3 phosphorylation in CFs. Taken together, these results suggest that diosgenin may inhibit Ang II‑induced ECM remodeling by suppressing the TGF‑β1/Smad3 signaling pathway in rat CFs. Therefore, diosgenin may possess therapeutic potential for the treatment of cardiac fibrosis.