Recently, chiral metasurfaces have drawn enormous attentions due to their flexibility in realizing nearly arbitrary chiral effect with designable strength. One intriguing direction in this field is ...chiral‐selective absorption. However, previous studies mostly require multilayer design and meanwhile often work in a passive way. Here, for the first time to the authors’ knowledge, a chiral‐selective metasurface absorber is experimentally demonstrated with a single‐layer free‐standing metasurface using coherent control method, where the strength of the chiral‐selective behavior can be actively tuned with a 100% modulation depth by simply changing the phase difference between the two coherent inputs. Specifically, under coherent symmetric illumination, near unity absorption is achieved for one circularly polarized incidence, while high‐efficiency cross‐polarization conversion is obtained for the other circularly polarized incidence. Such chiral‐selective absorption property is quite suitable for achieving coherent chiral‐selective wavefront control for the unabsorbed circularly polarized incidence. Three coherent chiral metagratings are designed and experimentally characterized by further employing Pancharatnam–Berry phase method and multiplexed method, where very good performances are achieved. The proposed approach on coherent control can enrich the functionalities and also improve the performances of the conventional single‐layer metasurfaces, which can find extending applications in various practical cases.
A coherent chiral‐selective metasurface absorber is experimentally demonstrated using a single‐layer metasurface, which can efficiently absorb one circularly polarized wave while converting the other to its cross‐polarized state. Taking advantage of such chiral properties, the authors further demonstrate three metagratings using Pancharatnam–Berry phase and multiplexed methods, showing the potential of their design in versatile chiral‐selective wavefront control applications.
A thermally tunable metamaterial comprising a periodic array of metallic split-ring resonators with an embedded semiconductor has been proposed. The resonance frequencies of the metamaterial are ...demonstrated to be continuously tuned in the terahertz regime by increasing the temperature. The tunability is attributed to the temperature-dependent permittivity of the embedded semiconductor and well analyzed by an equivalent capacitor–inductor model. The proposed designs ensure broadband thermally tunable terahertz devices.
► Semiconductors have a significant advantage in that their relative permittivity can be modified by changing the temperature. ► Metamaterials comprising semiconductor constituents thus enable a broadband thermal tuning of resonance frequency in the terahertz regime. ► A large blueshift of resonance frequency in our proposed structures as much as ~ 65% can be implemented with increasing temperature. ► The shifts of resonance frequency obtainable are quite consistent with the analytical predictions based on an equivalent
LC model.
Abstract
Aims
Intensive systolic blood pressure (SBP) lowering has been increasingly used; however, data is missing on patients who had target-achieved (TA). This study aims to show the ...cardiovascular effect of maintaining SBP at intensive levels.
Methods
The Strategy of Blood Pressure Intervention in Elderly Hypertensive Patients (STEP) trial was a multicentre, randomized, controlled trial which enrolled 8511 young-older (60–80 years) hypertensive patients without prior stroke to compare the cardiovascular prognosis of the intensive treatment (SBP target, 110 to <130 mmHg) vs. the standard treatment (130 to <150 mmHg). This secondary analysis assessed data in patients who achieved a mean SBP within target values. The association of mean achieved SBP and cardiovascular events was examined using a cubic spline function.
Results
In total, 3053 patients (72.0%) in the intensive-treatment group and 3427 (80.3%) in the standard-treatment group had an SBP target achieved, with mean follow-up SBP values of 124.2 mmHg and 137.4 mmHg, respectively. Throughout the median 3.38-year follow-up, the cardiovascular risk was significantly lower in the TA intensive-treatment group than in the TA standard-treatment group adjusted hazard ratio (HR) 0.61, 95% confidence interval (CI) 0.46–0.80; P < 0.001. In the intensive-treatment group, patients failing to achieve SBP targets presented higher cardiovascular risk than those TA patients (HR 2.04, 95% CI 1.44–2.88; P < 0.001). A J-shaped relationship was observed between the mean achieved SBP and risk of cardiovascular events, with the lowest risk at an SBP of 126.9 mmHg.
Conclusions
Maintaining SBP at <130 mmHg offers additional cardiovascular benefits among young-older patients with hypertension.
Registration
ClinicalTrials.gov: NCT03015311.
Lay Summary
This present study is a secondary analysis that investigated the association between mean achieved BP in the two treatment groups (SBP target, 110 to <130 vs. 130 to <150 mmHg) and their cardiovascular outcomes in the STEP study (60–80-year-old patients with hypertension).Patients achieving a target in the intensive-treatment group have better cardiovascular outcome than patients achieving a target in the standard treatment arm, supporting the cardiovascular benefits of maintaining SBP <130 mmHg.J-shaped relationships were observed between mean achieved SBP and cardiovascular outcomes (with the nadir around 130 mmHg), but not for stroke.
Graphical Abstract
Graphical Abstract
A broadband metamaterial absorber (MA) based on the titanium nitride (TiN) nano-disk array is studied using finite difference time domain simulations. The semiconducting indium tin oxide (ITO) thin ...film is introduced as the space layer in this sandwiched structure. Utilizing the symmetrical geometry of the MA structure, polarization insensitivity of the broadband absorption was gained. The absorber with TiN nano-disk array shows a peak absorbance of 99 % and larger than 98 % from 560 to 675 nm by numerical simulation. This compact design may have potential applications in the plasmonic sensing and photovoltaic devices.
Optical physical unclonable function (PUF) is one of the most promising hardware security solutions, which has been proven to be resistant to machine learning attacks. However, the disordered ...structures of the traditional optical PUFs are usually deterministic once they are manufactured and therefore exhibit fixed challenge-response behaviors. Herein, a reconfigurable PUF (R-PUF) is proposed and demonstrated by using the reversible phase transition behavior of VO
nanocrystals combined with TiO
disordered nanoparticles. Both the simulation and experiment results show that the near-infrared laser speckle pattern of the R-PUF can be almost completely altered after the phase transition of VO
nanocrystals, resulting in a reconfigurable and reproducible optical response. The similarity of the response speckles shows an obvious hysteresis loop during the rise and drop of temperature, providing a simple way to regulate and control the response behaviors of the R-PUF. More importantly, the hysteretic characteristic provides a new dimension to describe the challenge-response behavior of the R-PUF besides the laser speckle, providing an effective way to improve the security and encoding capacity of the optical PUFs. The proposed R-PUF can be employed as a promising security primitive for high robustness and high-security authentication and encryption.
Abstract Background Although extensive research has characterized intricate genetic programs in heart system, the information generated is highly fragmented. Here we have developed a new database ...called CardioSignal, which was designed for integration of regulatory information on the transcriptional regulation involved in heart development and cardiac hypertrophy. Methods Data about sequences, positions and functional annotation of transcription binding sites, cis -regulatory modules as well as promoters were collected from scientific literature. Genes involved in both processes were also manually gathered, particularly those preferentially expressed in the heart. Data was stored in MySQL database and Perl was used as the server-side programming language. Results Currently, CardioSignal contains 677 cardiac genes from twenty species. Among them are 128 cardiac transcription factors. Of the approximately 179 individual promoters from six species, the database also documented 247 experimentally verified binding sites and 64 cis -regulatory modules. CardioSignal may be searched for the promoter of a specific gene by specifying a gene name, Entrez geneID, swissProt accession number and so on. Downstream targets of transcriptional factors and cardiac regulatory modules can also be retrieved through a user-friendly web interface. Also available is experimental supporting evidence. Computational analysis tools were implemented for on-the-fly motif finding and comparative genomic analysis respectively. Conclusions CardioSignal offers a unique resource as it contains simultaneously the promoter collected while correlating the information of transcription factor binding sites and cis -regulatory modules from heart system. We are hopeful that its implementation will contribute toward the elucidation of the complex processes in cardiac development and hypertrophy.
The dielectric properties (epsilon and tan delta) of MZT-based ceramics can be tailored at both 1 MHz and the terahertz (THz) frequencies (0.2-2 THz) by CaTiO.sub.3 (CT) doping. CT was formed liquid ...phase during the sintering process and accelerated the densification of the ceramics. Doped with CT, the increase of the epsilon at 1 MHz could be explained by Lichtenecker expressions equation, and the tan delta is decreased at 1 MHz due to the high density. By doping with CT, the THz dielectric properties of ceramics can be modified, due to the variation of the lattice parameter and microstructure (porosity). At THz frequencies, ion displacement polarization is difficult to achieve, so that epsilon at THz is smaller than epsilon at 1 MHz according to Clausius-Mosotti equation. According to the four-parameter factorized oscillator model, the tan delta is increased with frequency up to THz frequencies. The power absorption of the MZT-based ceramics is lower than 10 cm.sup.-1 below 1 THz, and it is a good choice as a transparent material at terahertz domain, which may promote the development of terahertz devices.
We systematically studied the ability of 20 alkali halides to form solid hydrates in the frozen state from their aqueous solutions by terahertz time-domain spectroscopy combined with density ...functional theory (DFT) calculations. We experimentally observed the rise of new terahertz absorption peaks in the spectral range of 0.3–3.5 THz in frozen alkali halide solutions. The DFT calculations prove that the rise of observed new peaks in solutions containing Li+, Na+, or F– ions indicates the formation of salt hydrates, while that in other alkali halide solutions is caused by the splitting phonon modes of the imperfectly crystallized salts in ice. As a simple empirical rule, the correlation between the terahertz signatures and the ability of 20 alkali halides to form a hydrate has been established.
Escherichia coli is a leading cause of bloodstream infection (BSI) in hospitals and communities.
We conducted a retrospective study in 2015 to evaluate the clinical features and microbiological ...characteristics of E. coli BSI acquired in the hospital and community.
A total of 100 patients with E. coli BSI were enrolled, among whom 60 % had hospital-onset (HO) BSI while 40 % had community-onset (CO) BSI. Patients with HO BSI had higher percentages of haematological disorders, immunosuppression conditions, underwent surgery within 2 weeks and had a higher 30-day mortality. The prevalences of multidrug-resistant and extended-spectrum β-lactamase-producing strains were 81 and 60 %, respectively. Resistance percentages to ampicillin, ampicillin-sulbactam, cefazolin, ceftriaxone, ciprofloxacin and levofloxacin were greater than 50 %. Of the 43 different sequence types (STs) identified, ST131 (15.3 %) was the most common. The serum agglutination rate was 52 % in which 13 O and 11 H serogroups were observed. Among the 36 detected virulence factor (VF) genes, IutA (66 %) and traT (61 %) were the most predominant. papA, papC and papEF were different between the CO and HO BSI groups. VF scores were high (mean >7) in the frequently detected ST95, ST1193 and ST131.
This study revealed that the clinical features of HO and CO E. coli BSI were different. STs and serotypes showed a great diversity in this region while VF genes of the isolates varied between clones.
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