Liposomes are now considered the most commonly used nanocarriers for various potentially active hydrophobic and hydrophilic molecules due to their high biocompatibility, biodegradability, and low ...immunogenicity. Liposomes also proved to enhance drug solubility and controlled distribution, as well as their capacity for surface modifications for targeted, prolonged, and sustained release. Based on the composition, liposomes can be considered to have evolved from conventional, long-circulating, targeted, and immune-liposomes to stimuli-responsive and actively targeted liposomes. Many liposomal-based drug delivery systems are currently clinically approved to treat several diseases, such as cancer, fungal and viral infections; more liposomes have reached advanced phases in clinical trials. This review describes liposomes structure, composition, preparation methods, and clinical applications.
Liposomes; Phospholipids; Lamellarity; Stealth liposomes; Vaccinations.
At present, most of the existing studies on bamboo nodes focus on the raw bamboo. There is still a lack of researches on the nodes in side press-laminated bamboo lumber (LBL). However, after ...processing, bamboo nodes in the laminated bamboo lumber are different from the raw bamboo nodes in terms of performance. Therefore, this paper carried out tests to analyze the influence of bamboo node on the tensile properties parallel to grain of side press-laminated bamboo lumber. A total of 180 specimens were divided into six groups, and the number and position of the bamboo nodes at the specimen in each group were different. The effects of these factors on the strength, elastic modulus, and Poisson’s ratio of the side press-laminated bamboo lumber under tension parallel to grain were obtained. The tensile failure of side press-laminated bamboo lumber was a brittle fracture, and the typical failure mode can be classified into three types. The mean value for tensile strength was 127.18 MPa when there was no bamboo node, while the mean value was 89.99–107.37 MPa when there were one to three bamboo nodes. The number of bamboo nodes would significantly affect the tensile properties parallel to grain of side press-laminated bamboo lumber, whereas the position of bamboo nodes has an insubstantial impact. Comparisons with other research results were also carried out. A series of formulas were proposed based on the test results to reflect how the node influenced the mechanical properties of side press LBL under tensile conditions.
Due to the Internet of Things (IoT) requirements for a high-density network with low-cost and low-power physical (PHY) layer design, the low-power budget transceiver systems have drawn momentous ...attention lately owing to their superior performance enhancement in both energy efficiency and hardware complexity reduction. As the power budget of the classical transceivers is envisioned by using inefficient linear power amplifiers (PAs) at the transmitter (TX) side and by applying high-resolution analog to digital converters (ADCs) at the receiver (RX) side, the transceiver architectures with low-cost PHY layer design (i.e., nonlinear PA at the TX and one-bit ADC at the RX) are mandated to cope with the vast IoT applications. Therefore, in this paper, we propose the orthogonal shaping pulses minimum shift keying (OSP-MSK) as a multiple-input multiple-output (MIMO) modulation/demodulation scheme in order to design the low-cost transceiver architectures associated with the IoT devices. The OSP-MSK fulfills a low-power budget by using constant envelope modulation (CEM) techniques at the TX side, and by applying a low-resolution one-bit ADC at the RX side. Furthermore, the OSP-MSK provides a higher spectral efficiency compared to the recently introduced MIMO-CEM with the one-bit ADC. In this context, the orthogonality between the in-phase and quadrature-phase components of the OSP are exploited to increase the number of transmitted bits per symbol (bps) without the need for extra bandwidth. The performance of the proposed scheme is investigated analytically and via Monte Carlo simulations. For the mathematical analysis, we derive closed-form expressions for assessing the average bit error rate (ABER) performance of the OSP-MSK modulation in conjunction with Rayleigh and Nakagami-m fading channels. Moreover, a closed-form expression for evaluating the power spectral density (PSD) of the proposed scheme is obtained as well. The simulation results corroborate the potency of the conducted analysis by revealing a high consistency with the obtained analytical formulas.
Photonic crystal fibers (PCFs) have recently attracted compelling attention because of their numerous applications, particularly in the mid-infrared (mid-IR) wavelength region. In this paper, we have ...presented and analyzed mid-IR optical modulator based on phase-changing material (PCM) known as germanium-antimony-tellurium (GST) and D-shaped PCF. The modulation process can be performed as the GST material’s phase undergoes a transition between amorphous (on) and crystalline (off) states. To analyze the proposed design numerically, full vectorial finite element method (FVFEM) is employed. Further, we studied the light propagation through the suggested structure using 3D finite difference time domain (FDTD) method. The optical losses of the fundamental transverse electric (TE) mode supported by the reported structure in the two GST states are studied. The obtained extinction ratio (ER) of the proposed modulator approaches 302.61 dB, whereas the insertion loss (IL) is less than 0.00014 dB throughout the wavelength range from 3 to 5.8 μm at a device length (L
D
) of 0.2 mm. Therefore, the suggested modulator can be utilized in photonic integrated circuits that require high ER, very low IL, and large optical bandwidth.
Space modulation techniques (SMTs) have emerged as promising candidates for spectral- and energy-efficient wireless communication systems since they strike a good balance among error performance, ...power efficiency, spectrum efficiency, and receiver complexity. In SMTs, the information is not only conveyed by the habitual M-ary signal constellations; rather, it is also conveyed by the indices of the transmit antennas. As such, the indices of the transmit antennas are harnessed in such a manner that they enhance the transmission efficiency compared with the other multiple-input multiple-output opponents. Despite their exceptional advantages, SMTs suffer from a major drawback, which lies in the logarithmic proportion between their achievable data rates and the number of transmit antennas. In this regard, the fully generalized spatial modulation (F-GSM) and the fully quadrature spatial modulation (F-QSM) are proposed in this paper in order to vanquish this controversial drawback. In F-GSM and F-QSM, the transmit antennas used for data transmission are varied from the state in which only one transmit antenna is activated to the state in which multiple/all transmit antennas are activated. Therefore, a linear relationship between the achievable data rates and the number of transmit antennas is acquired. Moreover, a novel mathematical framework for assessing the average bit error rate performance of different SMTs is delineated. The driven mathematical framework is considered as the first major attempt to generalize the analytical analysis of different SMTs. In addition, the receiver's computational complexity of the proposed schemes is obtained and analyzed in terms of the computational complexity of different SMTs. The simulation results substantiate the validity of the analytical analysis conducted throughout the paper, as they are very akin to the obtained analytical formulas.
In order to meet the objective requirements of the safety and comfort of the modern lightweight timber floors, and strengthen the research on the coupling performance of the lightweight timber floors ...vibration characteristics and the building comfort, this article discusses the floor of a two-story prefabricated lightweight timber building demonstration house. In this paper, the floor structure of a two-story light-weight wooden house has been carried out on structural calculation modal and experimental modal, static uniform load and concentrated load deflection value testing. The evaluation of the deflection value of the floor structure, the mode shape, the coupling of the fundamental frequency mode parameters, and the vibration comfort were also studied. The results show that the fundamental frequency simulation value, one-way modal test value and two-way modal test value of the floor structure all meet the requirements of BS-6472 (BS6472-1:2008). That is, the floor structure is not lower than 8 Hz design requirements, and meets the frequency of BS-6472(BS6472-1:2008). The weighted root mean square acceleration is lower than the requirement of 0.45 m/s2; the first three natural frequencies of the floor structure calculated by the finite element simulation are 16.413, 31.847 and 48.921 Hz, and the fundamental frequency mode is the bending vibration in the length and width directions. The second order is the bending mode in the length direction, and the third order is the bending mode in the width direction. The fundamental frequency of the two-way modal test of the floor structure is the first-order bending mode in the X direction; and the second-order natural frequency is the second-order bending vibration shape in the X direction. when the uniform load is mainly the weight of floor own, the simulated maximum deflection value is 1.0658 mm; the simulation is performed according to the standard value of 0.566 kN/m for the uniform load of the floor design, and the simulation is the largest. The maximum deflection value of the simulated floor is 1.47383 mm at its midpoint, which meets the requirements of National Building Code of Canada-2015 (NBCC). The maximum deflection limit of the light wood structure floor system is lower than 3 m and the maximum deflection limit is 2 mm; the six deflection value test lines simulated under a concentrated load of 1 kN all present a parabolic distribution and are symmetrical. The above results has engineering application value for promoting the research on the vibration characteristics of the fabricated lightweight timber floors structure and its optimization design.
Over the past few years, dynamic spectrum access has been gaining an increasing attention as a solution to the spectrum scarcity problem. In this paper, a primary user detection technique based on ...Maximum A Posteriori estimation is proposed for dynamic spectrum access networks. In the proposed technique, a set of secondary users acting as sensing nodes send their individual decisions about the existence of the primary user to a central fusion center. The fusion center uses the received data to form a codeword then, applies the maximum a posteriori estimation rule to make a final decision regarding the presence of the primary user. The proposed technique takes into consideration the accuracy of the local decisions provided by the secondary users when making a final decision. In this paper, we analyze the performance of the proposed scheme and derive closed-form expressions for the upper bounds of the false alarm and misdetection probabilities. The results show that the proposed technique outperforms other combining techniques in terms of its ability to detect the primary user and, accordingly, minimizes the harmful interference to the licensed network. Moreover, the proposed technique achieves better performance at a lower number of reporting secondary users which compensates for the complexity of the maximum a posteriori estimation.
•Mechanical properties and working performance of SWSSC were analyzed.•The effect of seawater and/or sea sand on the performance of OPC was analyzed.•The long-term performance and corrosion mechanism ...of FRP in SWSSC were summarized.•The effect of CI− on the durability properties of SWSSC was summarized.
With the development of the marine economy and the deployment of national maritime power, a large number of coastal port structures and civil engineering projects need to be constructed. The preparation of traditional concrete will excessively consume river sand, ore, and freshwater resources, while also violating the concept of sustainable development. In order to solve the problems of lack of resources and high transportation costs, it is crucial to prepare seawater and sea sand concrete (SWSSC). This paper takes seawater and (or) sea sand concrete as the research object, and comprehensively analyzes the workability, mechanical performance, durability of SWSSC, and the development law of bonding performance and durability of SWSSC and fiber reinforced polymer (FRP) reinforcement composite structure by comparing the characteristics of seawater and sea sand. The results indicate that the early compressive strength of SWSSC develops faster than that of ordinary concrete, and the later strength of the two is similar. The chloride ions in seawater and sea sand cause corrosion of steel bars, but have little impact on carbonization depth and freeze–thaw resistance. Using mineral admixtures and FRP bars can effectively solve a series of durability problems caused by the high chloride ion content in SWSSC. However, alkaline environments significantly affect FRP bars and have good corrosion resistance in seawater environments.
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