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Background: The extent of postoperative pain following transoral thyroidectomy is not well-understood and remains a subject of debate. This study aims to analyze and compare postoperative pain levels between patients undergoing transoral and conventional transcervical thyroidectomy. Methods: A prospective evaluation on postoperative pain was conducted in 310 patients undergoing conventional thyroidectomy and 194 undergoing transoral thyroidectomy. Pain levels were evaluated using the numerical rating scale (NRS, ranging from 0 to 10) through preoperative and postoperative questionnaires at specified time points: 1, 3, and 6 days, and 1 and 3 months following surgery. Propensity score-matched analysis was carried out based on six covariates: sex, age, body mass index, extent of thyroidectomy, tumor size, and central neck dissection. Results: After propensity score matching based on the six covariates, 121 patient pairs were identified from each group. Within this matched cohort, postoperative pain scores significantly worsened 1 day after surgery but showed progressive recovery up to 3 months post-surgery in both groups. The transoral group exhibited higher postoperative pain scores than the conventional group from day 1 (4.43 ± 2.6 vs. 3.11 ± 2.5, p< 0.001) to day 6 (1.76 ± 1.9 vs. 1.13 ± 1.6, p= 0.016) post-surgery, with no significant difference noted at 1 month. Among transoral procedures, pain scores were significantly higher for the endoscopic approach compared to the robotic approach on days 1 (5.52 ± 2.3 vs. 4.29 ± 2.3, p= 0.028) and 3 (3.52 ± 2.5 vs. 2.64 ± 2.0, p= 0.047) post-surgery. Conclusions: Postoperative pain was significantly higher in transoral thyroidectomy compared to conventional thyroidectomy up to 6 days post-surgery. Within the transoral group, the robotic procedure resulted in lower pain levels than the endoscopic approach during the early postoperative period. Graphic abstract:

This paper presents the control of a wind turbine composed by a doubly fed induction generator (DFIG), which provides power to the main grid through a feeder. The control algorithm is designed following the modified Conditional Servo-Compensator (mCS) theory. This control technique was recently developed to a broad class of nonlinear systems, and this paper brings the first result applied to wind turbines. The mCS theory has several advantages compared to others, as it is a robust nonlinear control scheme. First, it provides rigorous stability analysis, that allows explicit definition of performance and operating conditions. Secondly, it is a robust controller, and only needs lump values and bounds for parameters and dynamics. Finally it is very simple and easy to implement, and does not need heavy computer burden, it is only based on standard local measurements, and represents a promising solution for real applications. The theoretical results are verified by simulations using detailed Simpower models. These simulations show very good results facing a Low Voltage Ride Through scenario, which is one of the most severe tests used for practical applications. The proposed scheme could easily be adapted to the control of other applications based on power converters, as the control of the interconnection of a full wind farm to the main grid, or the control of a terminal in a DC grid.

ABSTRACT

Polyphenolic chemicals found in tea leaves are frequently used in pharmaceutics and the food industry. Catechin is a polyphenol that has antimicrobial, antioxidant, and antibacterial effects, as well as other health advantages. The goal of this study was to create a catechin-encapsulated alginate hydrogel (Cate-ALG) that would protect catechin from degradation and bioactivity loss in stressful environments while also delivering catechin. The antioxidant ability of catechin was found to be greater than that of vitamin C using the 2,2-diphenyl-1-pierylhyrazyl assay. The FT-IR spectra revealed the distinct peaks of catechin and alginate. Additionally, due to the hydrogen bond interaction between alginate and catechin molecules, frequency downshifting was observed in the carbonyl and hydroxyl regions. Furthermore, release profile revealed a burst release of 5% catechin-ALG in the first 25 min. On the other hand, the 3% Cate-ALG approached the controlled release profile of catechin and increased the release time by more than 40 minutes. The catechin in alginate hydrogel has the potential for controlled release via transdermal and wound dressing applications.

Microwave vacuum drying is one of innovative drying techniques that is today used in drying of foods, medical products and other high quality products. In this drying technology, heat is generated by directly transforming the electromagnetic energy into kinetic molecular energy of water, thus the heat is produced deep within the material to be dried under vacuum environment. This paper presents the results of research on microwave vacuum drying of “Cat Chu” mango in Mekong Delta – Vietnam. “Cat Chu” mango, with moisture content of (80 ± 1) % (wet basis - wb), was sliced into 5 cm thickness, and was dried in mWaveVac0150-lc dryer (Püschner - Germany). The drying vacuum was from 60 to 120 mbar. Three levels of microwave power were established: the first phase from 600 to 800 W, the second phase from 300 to 500 W, the last one from 150 to 250 W. The control sample was dried by convective drying method at 60 °C; and vacuum drying at 70 mbar, 60 °C. The results of this research showed that high quality product in terms of color, surface shrinkage and structure was obtained by microwave vacuum drying. The drying time was about 45 min, 450 min and 870 min with microwave vacuum drying, vacuum drying and convective hot-air drying, respectively. In addition, Fick’s equation and Crank’s solution were applied to analyze and calculate the accessibility and diffusion coefficient of microwave vacuum drying process. Starting accessibility of process was significantly increased; the diffusivity obtained was within a range from 6.44*10-10 m2/s to 16.16*10-10 m2/s. The results also indicated that there was a higher exchange in surface and a greater internal diffusion of experimental microwave vacuum drying samples compared to the control vacuum and hot-air drying samples.

Magnetic nanoparticles of manganese doped ZnS has been synthesized with different molar ratios of manganese and zinc by co-precipitation method. Structure of the prepared nanocomposite was investigated using FT-IR, XRD, TEM and VSM. The most excellent photodegradation efficiency of Reactive Blue 198 (RB198) was observed with the molar ratio of Mn-doped ZnS/Fe3O4 and it was 1:1 in which molar percentage of Mn2+ was 9%. The experiments of dye degradation were carried out under visible light and UV radiation. Results shown that the degradation efficiency of RB198 was up to 100% at the concentration of 200 ppm for 10 minutes when the amount of catalyst was 0.2g/l. Additionally, the effect of various parameters including initial concentration, illumination time and pH to the photodegradation efficiency of dye was also carried out. More interestingly, the reusable experiments showed that the nanocomposited exhibited high photodegradation capacity after three cycles and can be recycled conveniently from water with the assist of an external magnet because of its exceptional properties.

Recently, the results of an electrodeposition of nickel showed that the coating plated in supercritical carbon dioxide, Sc-CO 2 , emulsion has smaller grain size, higher hardness, excellent coverage, low surface roughness and pinhole-free microstructure over its conventional counterpart. It was found that, even without the addition of surfactant in the electrolyte, similar improvement over the coating properties was also obtained. However, the presence of surfactant in the Sc-CO 2 electrolyte resulted in a predominant preferred {111} texture. Meanwhile, adjusting boric acid up to 15 g/L and decreasing current density to 5 A/dm 2 resulted in more preferred {111} Ni crystalline as well. In addition, the use of pulse current in the Sc-CO 2 electroplating further modified Ni crystal from {200} to {111} orientation.

Recent research in drug delivery, gelatin stand out from all other natural polymer by its property such as biocompatible, biodegradable, reduced immunogenicity. Modify porous nano silica (PNS) by gelatin to use for drug delivery can avoid the detection of the human immune system. In this study, the coated PNS was successfully formed with spherical shape and diameter around 70 nm determined by transmission electron microscopy (TEM). Drug loading and release behaviors of doxorubicine@PNS-gelatin, in particular, were also tested. This study is expected to improve the stability of PNS for drug delivery system in cancer therapy.

In this study a novel magnetic composite used as a photocatalyst with combination of zinc oxide nanoparticles and chitosan (ZnO/Fe3O4/CS) was synthesized by a simple co-precipitation method. The role of the prepared magnetic nanocomposite is to improve the removal efficiency of textile dye due to the photocatalytic activity of zinc oxide nanoparticles and reusable capacity of Fe3O4magnetic nanoparticles. Constituents and structure properties of ZnO/Fe3O4/CS were investigated by scanning electron microscopy (SEM), x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). Magnetic property of the prepared composite was determined by vibrating sample magnetometer (VSM). The results demonstrated that ZnO/Fe3O4/CS nanocomposite dramatically improved the removal efficiency of reactive blue 198 dye (RB198) with high photocatalytic activity and easy separation by a permanent magnet. In addition, the photocatalytic activity of the prepared composite was also performed under different parameters such as contact time, initial pH, the amount of composite and initial concentration of RB198. Interestingly, ZnO/Fe3O4/CS nanocomposite still showed high removal efficiency after recycling three times and performed in a real textile dyeing wastewater.

Magnetic nanoparticles of manganese doped ZnO have been prepared by co-precipitation method. Photocatalytic activity results show that 9% of Mn in Mn-doped ZnO exhibited the highest photodegradation efficiency of reactive blue 198 dye. Additionally, excellent photocatalytic activity was observed when the molar ratio of Mn-doped ZnO/Fe3O4was 1:1. The photodegradation of reactive blue 198 (RB198) dye was carried out with different illumination times, initial concentrations of dye, amounts of photocatalyst and pH of medium. The results reveal that the degradation efficiency of reactive blue 198 were 99% at the concentration of 30 ppm for 25 min when the amount of catalyst was 5 g L?1. The photodegradation of dye increased with increasing catalyst load. Furthermore, the prepared magnetic nanoparticles could also serve as convenient recyclable photocatalysts because of their magnetic properties. As a result, the removal of dye was still 90% after three times recycling.

In this paper, CoFe2O4/chitosan-graft-poly(acrylic acid) (CoFe2O4/CS-graft-PAA) nanocomposites were prepared successfully by coprecipitation of the compounds in alkaline solution and were used for removal of nickel (II) ions from aqueous solution. The sorption rate was affected significantly by the initial concentration of the solution, sorbent amount, and pH value of the solution. Batch experiments were conducted to investigate the adsorption capacity under different initial concentration (ranging from 25 to 150 mg L?1), solution pH (4.1, 5.3, 6.4 and 7.6), and contact time. These nanocomposites can be recycled conveniently from water with the assistance of an external magnet because of their exceptional properties. The prepared nanocomposites were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), x-ray powder diffraction (XRD), and thermogravimetric analysis (TGA).

The amphiphilic triblock copolymer of poly(?-caprolactone)-b-poly(ethylene glycol)-b- poly(?-caprolactone) (PCL-PEG-PCL) was prepared by ring opening polymerization of PEG and ?-caprolactone in the presence of stannous 2-ethyl hexanoate (Sn(Oct)2) as catalyst. The structure of triblock copolymer was characterized by proton nuclear magnetic resonance (1H?NMR), Fourier transform infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC). The polymeric nanoparticles were prepared in aqueous solution by a co-solvent precipitation technique at room temperature. Nanoparticles were formed from the amphiphilic triblock copolymer, and the effect of organic solvent water-miscibility on the size of nanoparticles was also investigated. Polymeric nanoparticles were measured by dynamic light scattering (DLS), with sizes in the range of 70-90?nm and narrow polydispersity. Additionally, the toxicities of polymeric micelles were evaluated by MTT assay. These results confirmed low toxic polymeric micelles and suggest that the polymeric micelles hold a potential for anticancer drug delivery.

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