Determination of tetracyclines in meat using two phases freezing extraction method and HPLC-DAD

Food Analytical Methods - The protein binding of tetracyclines may cause the common extraction methods are not able to completely remove them from the proteins. To overcome this problem, we...     

Nanoporous Ag and Pd foam: Redox induced fabrication using electrochemically deposited nanoporous Cu foam with no need to any additive

A simple, rapid and green method for fabrication of nanoporous metal (Ag and Pd) foams using electrochemically deposited nanoporous copper foam is presented. Ideally direct electrochemical formation of Ag and Pd foam structures without any additive reagent does not lead to a desired result; however, indirect fabrication starting from electrochemically fabricated Cu foam seems promising. Highly porous copper foam is fabricated electrochemically at a copper sheet and in turn serves as a hard template and a redox inducer for the deposition of Ag or Pd. The redox induced replacement of copper foam with Ag or Pd is done via simple immersion of as-fabricated nanoporous copper foam in cation aqueous solutions of Ag or Pd. The surface morphology of the as-fabricated foam is characterized by scanning electron microscopy (SEM), EDX and X-ray diffraction. The hydrogen evolution reaction is investigated as an example to demonstrate the electrocatalytic ability of as-fabricated foams.     

Improving adaptive receivers performance in molecular communication via diffusion

Forthcoming applications for molecular communications (MC) such as drug‐delivery and health monitoring will require robust receiver capabilities to mitigate channel memory and inter symbol interference caused by previous transmitted symbols. Here, the authors introduce an adaptive weighted algorithm to reduce the influence of these factors. This novel signal detection is deployed on to a concentration‐based MC system with absorbing receiver which is based on the so‐called first passage time concept. The proposed detector has low complexity and does not require explicit channel knowledge. To evaluate authors’ proposed algorithm, a theoretical approach is developed to derive the bit error rate (BER). Numerical results also carried out to verify the accuracy of these formulations and establish that the new detector will achieve better performance in comparison with other common low‐complex detectors under certain scenarios. Additionally, the authors propose a simple pre‐coding technique to combat the sequence of consecutive ones in low ISI scenarios. Also a comparison between detectors is given, which is based on the variation of distance, symbol period, signal‐to‐noise ratio (SNR), and number of molecules.Inspec keywords: radio receivers, error statistics, signal detection, intersymbol interferenceOther keywords: low‐complex detectors, low ISI scenarios, symbol period, signal‐to‐noise ratio, adaptive receivers performance, molecular communication, drug‐delivery, health monitoring, robust receiver capabilities, channel memory, inter symbol interference, previous transmitted symbols, adaptive weighted algorithm, novel signal detection, concentration‐based MC system, absorbing receiver, passage time concept, low complexity, explicit channel knowledge, authors, theoretical approach, bit error rate, numerical results     

Immunomodulatory Hydrogels: Advanced Regenerative Tools for Diabetic Foot Ulcer

Diabetic foot ulcer (DFU) is one of the most common complications of diabetes, bringing physical and mental challenges for patients due to the lack of efficient curative therapy. Despite considerable advances in pharmacological and surgical approaches, clinical trials for DFU patients remain disappointing due to the local overactive and excessive inflammation. Immunomodulatory hydrogels has significant advantages to overcome the clinical challenge of DFUs therapy. Here, recent fabrication and regenerative advances in the utilization of functional hydrogels for altering the immune microenvironment of DFUs are comprehensively reviewed. The pathological features and the healing processes of DFUs, followed by summarizing the physicochemical properties essential for the design of regenerative hydrogels for immunomodulation in DFUs, are briefly introduced. Then, the potential immuno-therapeutic modalities of hydrogels and emerging trends used to treat DFUs via multitherapeutic approaches and enhanced efficacy and safety are discussed. Taken together, by linking the structural properties of hydrogels to their functions in DFU therapy with a particular focus on immunomodulatory stimuli, this review can promote further advances in designing advanced hydrogels for DFUs, resulting in improved diabetic wound repair through translation into clinical setting in the near future.     

Nutlin‐3a and Cytokine Co‐loaded Spermine‐Modified Acetalated Dextran Nanoparticles for Cancer Chemo‐Immunotherapy

The combination of chemo‐ and immunotherapy represents one promising strategy to overcome the existent challenges in the present‐day anticancer therapy. Here, spermine‐modified acetalated dextran nanoparticles (Sp‐AcDEX NPs), co‐loaded with the non‐genotoxic molecule Nutlin‐3a (Nut3a), and the cytokine granulocyte–macrophage colony‐stimulating factor (GM‐CSF), are developed to induce cancer cell death and create a specific antitumor immune response. These polymeric NPs release Nut3a in a pH dependent fashion and induce endosomal escape. Due to Nut3a, the loaded NPs exert specific toxicity toward wild‐type p53 cancer cells while avoiding toxicity in immune cells. Furthermore, the NPs show intrinsic immune adjuvancy on monocyte derived‐dendritic cells, upregulating the expression of cell surface CD83 and CD86 costimulatory markers. Finally, it is examined that by inducing MCF‐7 breast cancer cell death and acting as immune adjuvants, the NPs can downregulate the expression of IL‐10 and upregulate IL‐1β, leading to proliferation of CD3⁺ and cytotoxic CD8⁺ T cells. Overall, the study suggests that Sp‐AcDEX NPs loaded with Nut3a and GM‐CSF is a promising system for chemo‐immunotherapy, capable of inducing tumor cell death and stimulating immune response.     

Forming limit diagram of aluminum/copper bi-layered tubes by bulge test

Chemo-mechanical-grinding (CMG) is a hybrid process which integrates chemical reaction and mechanical grinding between abrasives and workpiece into one process. It has been successfully applied into manufacturing process of silicon wafers where both geometric accuracy and surface quality are required. This paper aims to study the potential of CMG process in manufacturing process of single crystal sapphire wafers. The basic material removal mechanism in terms of chemical effect and mechanical effect in CMG process has been analysed based on experiment results of two different kinds of CMG wheels. The experiment results suggest that chromium oxide (Cr₂O₃) performs better than silica (SiO₂) in both material removal rate (MRR) and surface quality. It also reveals that, no matter under dry condition or wet condition, CMG is with potential to achieve excellent surface quality and impressive geometric accuracy of sapphire wafer. Meanwhile, test result by Raman spectrum shows that, by using Cr₂O₃ as abrasive, the sub-surface damage of sapphire wafer is hardly to be detected. Transmission electron microscopy (TEM) tells that the sub-surface damage, about less than 50 nm, might remain on the top surface if chemical effect is not sufficient enough to meet the balance with mechanical effect in CMG process.     

The effect of hydrodynamic parameters on probability of bubble–particle collision and attachment

In this study the dependence of the impeller speed on the particle size variation was investigated on the quartz particles using laboratory mechanical flotation cell. Maximum recovery was obtained at 1100 rpm. For either more quiescent (impeller speed <900 rpm) or more turbulent (impeller speed >1300 rpm) conditions, flotation recovery decreased steadily. Furthermore, amount of collision probabilities is calculated using various equations. According to this study, maximum collision probability was obtained around 48.35% with impeller speed of 1100 rpm, air flow rate of 15 l/h and particle size of 545 μm and minimum collision probability was obtained around 2.43% with impeller speed of 700 rpm, air flow rate of 15 l/h and particle size of 256 μm. Maximum attachment probability was obtained around 44.16% with impeller speed of 1300 rpm, air flow rate of 75 l/h and particle size of 256 μm. With using some frothers such as poly propylene glycol, MIBC and pine oil, probability of collision increased, respectively. Maximum collision probability was obtained around 65.46% with poly propylene glycol dosage of 75 g/t and particle size of 545 μm.     

X-Ray Measurement and Enhancement of SBUPF1 Plasma Focus Device in Different Ar Pressures and Operating Voltages

In this paper, best condition of filling gas pressure and operating voltage for SBUPF1 plasma focus device to have maximum intensity of hard and soft X-ray emission has been reported. For time resolved X-ray detection, PIN detector and fast plastic Scintillator detector with appropriate filters have been used and for time integrated X-ray emission measurement, radiography films with appropriate filter masks have been used. Rogowski coil has been used for pinch detection. The highest hard X-ray emission has been observed at the pressure of 0.45 mbar of Argon and discharge voltage about 23.5 kV. The highest Soft X-ray emission has been observed at the pressure of 0.35 mbar of Argon and discharge voltage about 23.5 kV. For enhancement of hard X-ray emission intensity, lead disk was placed in copper anode tip and measurements were repeated. Results have shown that hard X-ray emission has been enhanced about 23% and soft X-ray emission has been enhanced about 33% with inserting a high atomic number metal disk like lead. Results from integral X-ray measurement have shown presence of dominant peaks in ranges 13.2–15, 21–21.9 and 23.4–24.3 keV with significant spectral components in the range of 0–50 keV. Pinch size has measured with pin hole camera and it is about 0.6 mm × 2.12 mm. Captured images with SBUPF1 have confirmed that it is a suitable source for introspective imaging with capability of showing very fine details.