Multi-objective hybrid split-ring resonator and electromagnetic bandgap structure-based fractal antennas using hybrid metaheuristic framework for wireless applications.

Design closure and parameter optimisation are crucial in creating cutting-edge antennas. Antenna performance can be improved by fine-tuning preliminary designs created using theoretical considerations and rough dimension adjustment via supervised parameter sweeps. This paper introduces a frequency reconfigurable antenna design that can operate at 28/38 GHz frequencies to meet FCC and Ofcom standards for 5G applications and in the 18 GHz frequency band for K-band radar applications. A PIN diode is used in this design to configure multiple frequency bands. The antenna has a modified rectangular patch-like structure and two optimised plugins on either side. The study that is being presented focuses on maximising the parameters that are subject to optimisation, including length (Ls), width (Ws), strip line width (W1), and height (ht), where the antenna characteristic parameters such as directivity is tuned by a hybrid optimisation scheme called Elephant Clan Updated Grey Wolf Algorithm (ECU-GWA). Here, the performance of gain and directivity are optimally attained by considering parameters such as length, width, ground plane length, width, height, and feed offsets X and Y. The bandwidth of the proposed antenna at - 10 dB is 0.8 GHz, 1.94 GHz, and 7.92 GHz, respectively, at frequencies 18.5 GHz, 28.1 GHz, and 38.1 GHz. Also, according to the simulation results, in the 18 GHz, 28 GHz, and 38 GHz frequencies S11, the return loss is - 60.81 dB, - 56.31 dB, and - 14.19 dB, respectively. The proposed frequency reconfigurable antenna simulation results achieve gains of 4.41 dBi, 6.33 dBi, and 7.70 dBi at 18.5 GHz, 28.1 GHz, and 38.1 GHz, respectively. Also, a microstrip quarter-wave monopole antenna with an ellipsoidal-shaped complementary split-ring resonator-electromagnetic bandgap structure (ECSRR-EBG) structure has been designed based on a genetic algorithm having resonating at 2.9 GHz, 4.7 GHz, 6 GHz for WLAN applications. The gain of the suggested ECSRR metamaterial and EBG periodic structure, with and without the ECCSRR bow-tie antenna. This is done both in the lab and with numbers. The measured result shows that the ECSRR metamaterial boosts gain by 5.2 dBi at 5.9 GHz. At 5.57 GHz, the two-element MIMO antenna achieves its lowest ECC of 0.00081.

Description and molecular analysis of an Italian population of Centrorhynchus globo caudatus (Zeder, 1800) Lühe, 1911 (Acanthocephala: Centrorhynchidae) from Falco tinnunculus (Falconidae) and Buteo buteo (Accipitridae).

Centrorhynchus globocaudatus (Zeder, 1800) Lühe, 1911 (Centrorhynchidae) was reported in birds of prey. Our population from Falco tinnunculus Linnaeus (Falconidae) and Buteo buteo Linnaeus (Accipitridae) in northern Italy was morphologically distinct from others described elsewhere. The worms are elongate and cylindrical. Proboscis long, apically truncated and bare, with wider base and variably faint constriction at point of attachment of receptacle. Large anterior hooks well rooted; posterior spiniform hooks with reduced roots; transitional hooks with scutiform roots in-between. Four tubular cement glands extend into prominent ducts overlapping a large Saefftigen's pouch. Bursa large, with sensory plates. Vagina with laterally slit orifice in sub-ventral pit of globular terminal extension. Thick-shelled eggs ovoid without polar prolongation of fertilization membrane. In our specimens, proboscis hooks, receptacle, male reproductive system, and lemnisci especially in males varied in size from those from Ukraine, India, Egypt, Kyrgystan, Russia, Georgia, Armenia and Asian Soviet Republics. Our description of the Italian specimens includes new morphological information supported by scanning electron microscopy and microscope images, molecular analysis and energy dispersive X-ray analysis (EDXA) of hooks. Additional new details of proboscis hook roots, micropores and micropore distribution are described. Metal composition of hooks (EDXA) demonstrated high levels of calcium and phosphorous, and high levels of sulphur in core and cortical layers of eggs. The molecular profile based on sequences of 18S and cytochrome c oxidase 1 genes is also provided, as well as phylogenetic reconstructions including all available sequences of the family Centrorhynchidae, although further sequences are needed in order to clarify their phylogenetic relationships.

Ultrastructure of male Centrorhynchus globocaudatus (Acanthocephala) cement apparatus and function of cement gland secretion.

Cement glands are one of the most conspicuous and distinctive elements of taxonomic interest in male Acanthocephala. Cement glands vary in shape, number and arrangement in different classes of the taxon. The glands and their products have a fundamental role in the reproductive process. Light and electron microscopy were used to investigate the ultrastructure of the cement apparatus, which includes both cement glands and the cement reservoir, in mature males of Centrorhynchus globocaudatus (Zeder, 1800). Centrorhynchus globocaudatus is an enteric parasite of birds of prey, including Falco tinnunculus (Linnaeus, 1758) and Buteo buteo (Linnaeus, 1758) from the province of Ferrara (northern Italy). The four elongated cement glands of C. globocaudatus are situated posterior to the testes. Sections through the cement glands show each gland is surrounded by a fibrous envelope with an approximate thickness of 0.6 µm. Beneath this envelope is an outer cytoplasmic layer thickness ranging from 22 to 26 µm, which contains a number of nuclei with diameters variable from 20 to 22 µm. The cytoplasmic layer is filled with prominent free ribosomes and many mitochondria with lamellar cristae. Secretory granules, measuring from 1 to 1.3 µm in diameter, are formed within the cytoplasmic layer. The cytoplasmic layer surrounds the luminal area for storage of the cement material in each gland. Cement gland ducts arise from the gland and extend towards a common cement reservoir in close contact with the seminal vesicle and Saefftigen's pouch. Microtubules, large secretory granules and rest of undefined organelles were also observed within the cement reservoir.

Long-Lived Hot Carriers in III-V Nanowires.

Heat management mechanisms play a pivotal role in driving the design of nanowire (NW)-based devices. In particular, the rate at which charge carriers cool down after an external excitation is crucial for the efficiency of solar cells, lasers, and high-speed transistors. Here, we investigate the thermalization properties of photogenerated carriers by continuous-wave (cw) photoluminescence (PL) in InP and GaAs NWs. A quantitative analysis of the PL spectra recorded up to 310 K shows that carriers can thermalize at a temperature much higher than that of the lattice. We find that the mismatch between carrier and lattice temperature, ΔT, increases exponentially with lattice temperature and depends inversely on the NW diameter. ΔT is instead independent of other NW characteristics, such as crystal structure (wurtzite vs zincblende), chemical composition (InP vs GaAs), shape (tapered vs columnar NWs), and growth method (vapor-liquid-solid vs selective-area growth). Remarkably, carrier temperatures as high as 500 K are reached at the lattice temperature of 310 K in NWs with ∼70 nm diameter. While a population of nonequilibrium carriers, usually referred to as "hot carriers", is routinely generated by high-power laser pulses and detected by ultrafast spectroscopy, it is quite remarkable that it can be observed in cw PL measurements, when a steady-state population of carriers is established. Time-resolved PL measurements show that even in the thinnest NWs carriers have enough time (∼1 ns) after photoexcitation to interact with phonons and thus to release their excess energy. Nevertheless, the inability of carriers to reach a full thermal equilibrium with the lattice points to inhibited phonon emission primarily caused by the large surface-to-volume ratio of small diameter NWs.

Biomarcadores en el paciente con dolor torácico: pasado, presente y futuro / Biomarkers in the patient with chest pain: past, present, and future

En los últimos años gracias a la introducción de biomarcadores se ha avanzado mucho en el manejo de pacientes con dolor torácico. Desde los años 90 las troponinas cardiacasse han instaurado como una herramienta esencial en el diagnóstico precoz del infarto de miocardio. Recientemente, la aparición de troponinas de alta sensibilidad han implicado un importante adelanto en el diagnóstico de estos pacientes. Este artículo revisa brevemente el uso de troponinas de alta sensibilidad y sus diferencias con las troponinas convencionales en los servicios de urgencias, así como las limitaciones que su uso conlleva. Además resume los diferentes biomarcadores que han salido a la luz en los últimos años, como es el caso de la copeptina y su posible papel en los sevicios de urgencias. Por último repasamos las mejoras que se esperan en el futuro en el campo de los biomarcadores y el síndrome coronario agudo (AU)

Biochemical markers have greatly advanced the management of patients with chest pain in recent years. The measurement of cardiac troponins has provided an essential tool for the early diagnosis of myocardial infarction since the1990s, and the introduction of tests for highly sensitive troponins represents a significant recent advance. This brief review of testing for highly sensitive troponins in comparison with conventional troponins discusses their value in emergency departments and their limitations. Other recently introduced biomarkers, such as copeptin, are also considered for their possible use in emergency care. Finally, we describe improvements that can be expected with respect to biomarkers in acute coronary syndrome (AU)

Imaging with low-voltage scanning transmission electron microscopy: a quantitative analysis.

A dedicated specimen holder has been designed to perform low-voltage scanning transmission electron microscopy in dark field mode. Different test samples, namely InGaAs/GaAs quantum wells, InGaAs nanowires and thick InGaAs layers, have been analysed to test the reliability of the model based on the proportionality to the specimen mass-thickness, generally used for image intensity interpretation of scattering contrast processes. We found that size of the probe, absorption and channelling must be taken into account to give a quantitative interpretation of image intensity. We develop a simple procedure to evaluate the probe-size effect and to obtain a quantitative indication of the absorption coefficient. Possible artefacts induced by channelling are pointed out. With the developed procedure, the low voltage approach can be successfully applied for quantitative compositional analysis. The method is then applied to the estimation of the In content in the core of InGaAs/GaAs core-shell nanowires.

Microscopic mechanisms of self-compensation in Si delta-doped GaAs.

We combined systematic cross-sectional scanning tunneling microscopy and spectroscopy investigations with Hall measurements on single Si delta-doped layers, as well as Si delta-doped superlattices in GaAs. We found that Si self-compensation involves nucleation and growth of electrically neutral Si precipitates at the expense of the conventional donor Si phase.

Resonant transport in Nb /GaAs /AlGaAs heterostructures: realization of the de Gennes-Saint-James model.

Resonant transport is demonstrated in a hybrid superconductor-semiconductor heterostructure junction grown by molecular beam epitaxy on GaAs. This heterostructure realizes the model system introduced by de Gennes and Saint-James in 1963 [P. G. de Gennes and D. Saint-James, Phys. Lett. 4, 151 (1963)]. At low temperatures a single marked resonance peak is shown superimposed to the characteristic Andreev-dominated subgap conductance. The observed magnetotransport properties are successfully analyzed within the random matrix theory of quantum transport, and ballistic effects are included by directly solving the Bogoliubov-de Gennes equations.

Aminophylline and increased activity of peripheral chemoreceptors in newborn infants.

Peripheral chemoreceptor activity was studied in nine healthy, unsedated neonates (with a mean (SD) postconceptional age of 39 (2) weeks and birth weight of 3000 (400) g) by measuring the inhibition of ventilation elicited by five breaths of 100% oxygen (Dejours technique). Changes in tidal volume, frequency, and minute ventilation were measured before and after administration of aminophylline (10 mg/kg by mouth). Before aminophylline hyperoxia induced a decrease in minute ventilation (from a mean (SE) of 825 (55) to 520 (30) ml/kg/min) as result of reduction of tidal volume (from 12 (0.3) to 8 (0.3) ml/kg). After aminophylline administration the hyperoxia induced decrease in tidal volume (from 14 (0.7) to 6 (0.3) ml/kg) and minute ventilation (from 847 (57) to 386 (21) ml/kg/min) was significantly greater than before. It is concluded that in neonates peripheral chemoreceptors are more active in the presence of aminophylline. It is speculated that aminophylline increases the activity of peripheral chemoreceptors, reducing the breakdown of cAMP, which is a crucial mediator for peripheral chemoreceptor discharge.