Microwaves

微波
  • 文章类型: Journal Article
    杏仁树是世界上栽培最多的坚果树。生产杏仁会产生大量的副产品,其中大部分未使用。在这里,这项研究旨在开发一种绿色化学方法来鉴定和提取潜在有价值的化合物从杏仁副产品。最初,用10种不同的天然深共晶溶剂(NADES)进行筛选。乳酸/甘油的混合物,摩尔比为1:1(1:50植物材料与NADES(w/v),水含量为20%v/v)被确定为儿茶素的最佳提取溶剂,咖啡酰奎宁酸,和浓缩的杏仁壳中的单宁。随后,通过使用小型化提取技术的实验设计(DoE)协议对方法进行了优化,微波辅助萃取(MAE),与所选的NADES一起使用。发现最佳条件为70°C,辐照时间为15分钟。通过实验确认了由DoE确定的最佳提取条件,并与文献中已经建立的方法进行了比较。在这些条件下,代谢物的提取量高2.4倍,根据总峰面积的增加,而不是使用的既定文献方法。此外,通过应用多参数分析绿色度量(AGREE)和绿色分析过程指数(GAPI)度量,可以得出结论,所开发的方法比已建立的文献方法更绿色,因为它包括绿色分析化学的各种原理。
    Almond trees are the most cultivated nut tree in the world. The production of almonds generates large amounts of by-products, much of which goes unused. Herein, this study aimed to develop a green chemistry approach to identify and extract potentially valuable compounds from almond by-products. Initially, a screening was performed with 10 different Natural Deep Eutectic Solvents (NADESs). The mixture lactic acid/glycerol, with a molar ratio 1:1 (1:50 plant material to NADES (w/v) with 20% v/v of water) was identified as the best extraction solvent for catechin, caffeoylquinic acid, and condensed tannins in almond hulls. Subsequently, a method was optimized by a Design of Experiment (DoE) protocol using a miniaturized extraction technique, Microwave-Assisted Extraction (MAE), in conjunction with the chosen NADESs. The optimal conditions were found to be 70 °C with 15 min irradiation time. The optimal extraction conditions determined by the DoE were confirmed experimentally and compared to methods already established in the literature. With these conditions, the extraction of metabolites was 2.4 times higher, according to the increase in total peak area, than the established literature methods used. Additionally, by applying the multiparameter Analytical Greenness Metric (AGREE) and Green Analytical Process Index (GAPI) metrics, it was possible to conclude that the developed method was greener than the established literature methods as it includes various principles of green analytical chemistry.
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  • 文章类型: Journal Article
    最近,提出了一种利用微波抑制疟原虫生长的新方法。然而,用于演示这种方法的设备成本高,不可移动,阻碍了这一研究领域的进展,仍处于早期阶段。本文提出了重新设计,建筑,和等效系统的验证,将其转换为便携式且低成本的系统,能够取代现有的。该系统主要由射频发生器(MAX2870)、RF放大器(SKYWORKS66292-11)和图形用户界面。同样,原始研究提出的射频施加器进行了重新设计,导致回波损耗提高了五倍。获得的结果表明,所提出的系统实现了90%的寄生虫生长抑制,以不到其成本的1%匹配其对应方的性能。这些结果代表了创造更小,增强的设备,为对抗这种毁灭性疾病的替代治疗开辟了新的可能性。
    Recently, a novel method for the growth inhibition of malaria parasites using microwaves was proposed. However, the apparatuses used to demonstrate this method are high-cost and immovable, hindering the progression in this field of research, which is still in its early stages. This paper presents the redesign, construction, and validation of an equivalent system, converting it into a portable and low-cost system, capable of replacing the existing one. The proposed system is mainly composed of an RF generator (MAX2870), an RF amplifier (SKYWORKS 66292-11) and a graphical user interface. Likewise, the RF applicator proposed by the original study was redesigned, resulting in a five-fold improvement in return loss. The obtained results indicate that the proposed system achieves 90% parasite growth inhibition, matching the performance of its counterpart at less than 1% of its cost. These results represent a breakthrough for the creation of smaller, enhanced devices that open new possibilities for an alternative treatment to combat this devastating disease.
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  • 文章类型: Journal Article
    通过机械榨油过程中提高采油率,可以在一定程度上克服食用芥子油供需之间的巨大差距。据报道,芥菜种子的微波(MW)预处理可以对机械可表达油的可用性产生积极影响。以床厚和暴露时间为变量,使用高光谱成像(HSI)来了解微波(MW)处理种子中油的空间传播变化,使用可见近红外(可见近红外,400-1000nm)和短波红外(SWIR,1000-1700nm)系统。使用化学计量学技术分析光谱数据,例如偏最小二乘判别分析(PLS-DA)和回归(PLSR),以开发预测模型。PLS-DA模型显示出强大的能力,以96.6和99.5%的高精度水平,从对照样品进行不同MW预处理的芥菜种子的Vis-NIR和SWIR-HSI分类,分别。用SWIR-HSI光谱数据建立的PLSR模型预测(R2>0.90)油含量和油酸等脂肪酸成分,芥酸,饱和脂肪酸,和PUFA最接近分析技术获得的结果。然而,使用Vis-NIR光谱数据时,这些预测(R2>0.70)的准确性较低.
    The wide gap between the demand and supply of edible mustard oil can be overcome to a certain extent by enhancing the oil-recovery during mechanical oil expression. It has been reported that microwave (MW) pre-treatment of mustard seeds can have a positive effect on the availability of mechanically expressible oil. Hyperspectral imaging (HSI) was used to understand the change in spatial spread of oil in the microwave (MW) treated seeds with bed thickness and time of exposure as variables, using visible near-infrared (Vis-NIR, 400-1000 nm) and short-wave infrared (SWIR, 1000-1700 nm) systems. The spectral data was analysed using chemometric techniques such as partial least square discriminant analysis (PLS-DA) and regression (PLSR) to develop prediction models. The PLS-DA model demonstrated a strong capability to classify the mustard seeds subjected to different MW pre-treatments from control samples with a high accuracy level of 96.6 and 99.5% for Vis-NIR and SWIR-HSI, respectively. PLSR model developed with SWIR-HSI spectral data predicted (R2 > 0.90) the oil content and fatty acid components such as oleic acid, erucic acid, saturated fatty acids, and PUFAs closest to the results obtained by analytical techniques. However, these predictions (R2 > 0.70) were less accurate while using the Vis-NIR spectral data.
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  • 文章类型: Journal Article
    罗勒种子胶的分散体具有高粘度并表现出剪切稀化行为。本研究旨在分析不同时间间隔(0、1、2和3分钟)的微波处理(MT)对罗勒种子胶分散体(0.5%,w/v)。这项研究的发现表明,罗勒种子胶分散体(未处理的分散体)的表观粘度从0.330Pa降低。S到0.068Pa。s随着剪切速率(SR)从12.2s-1增加到171.2s-1。此外,罗勒种子胶分散体的表观粘度从0.173Pa降低。s到0.100Pa。s随着MT时间从0增加到3分钟(SR=61s-1)。使用幂律(PL)成功地模拟了口香糖分散体的流变特性,宾汉姆,Herschel-Bulkley(HB),和卡森模型,PL模型是描述罗勒种子胶分散行为的最佳模型。PL模型显示出优异的性能,对于所有口香糖分散体,具有最大r值(平均r值=0.942)和最小平方误差(SSE)值(平均SSE值=5.265)和均方根误差(RMSE)值(平均RMSE值=0.624)。MT对罗勒种子胶分散体的稠度系数(k值)和流动行为指数(n值)的变化有相当大的影响(p<0.05)。罗勒种子胶分散的k值从3.149Pa显着降低。sn到1.153Pa。sn(p<0.05)随着MT时间从0增加到3分钟。随着MT时间的增加,罗勒种子胶分散的n值从0.25显着增加到0.42(p<0.05)。罗勒种子胶分散体的宾汉塑性粘度从0.029Pa显著增加。S到0.039Pa。s(p<0.05),而MT的持续时间增加。随着MT时间从0增加到3分钟,罗勒种子胶分散体的Casson屈服应力从5.010Pa显着降低到2.165Pa(p<0.05)。
    Dispersion of Basil seed gum has high viscosity and exhibits shear-thinning behavior. This study aimed to analyze the influence of microwave treatment (MT) at various time intervals (0, 1, 2, and 3 min) on the viscosity and rheological behavior of Basil seed gum dispersion (0.5%, w/v). The finding of this study revealed that the apparent viscosity of Basil seed gum dispersion (non-treated dispersion) reduced from 0.330 Pa.s to 0.068 Pa.s as the shear rate (SR) increased from 12.2 s-1 to 171.2 s-1. Additionally, the apparent viscosity of the Basil seed gum dispersion reduced from 0.173 Pa.s to 0.100 Pa.s as the MT time increased from 0 to 3 min (SR = 61 s-1). The rheological properties of gum dispersion were successfully modeled using Power law (PL), Bingham, Herschel-Bulkley (HB), and Casson models, and the PL model was the best one for describing the behavior of Basil seed gum dispersion. The PL model showed an excellent performance with the maximum r-value (mean r-value = 0.942) and the minimum sum of squared error (SSE) values (mean SSE value = 5.265) and root mean square error (RMSE) values (mean RMSE value = 0.624) for all gum dispersion. MT had a considerable effect on the changes in the consistency coefficient (k-value) and flow behavior index (n-value) of Basil seed gum dispersion (p < 0.05). The k-value of Basil seed gum dispersion decreased significantly from 3.149 Pa.sn to 1.153 Pa.sn (p < 0.05) with increasing MT time from 0 to 3 min. The n-value of Basil seed gum dispersion increased significantly from 0.25 to 0.42 (p < 0.05) as the MT time increased. The Bingham plastic viscosity of Basil seed gum dispersion increased significantly from 0.029 Pa.s to 0.039 Pa.s (p < 0.05) while the duration of MT increased. The Casson yield stress of Basil seed gum dispersion notably reduced from 5.010 Pa to 2.165 Pa (p < 0.05) with increasing MT time from 0 to 3 min.
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  • 文章类型: Journal Article
    虽然治疗肾脏肿瘤的金标准是手术治疗,热消融方法是一种可行的治疗选择,适用于肾脏小肿块(<4cm)患者,但手术治疗效果较差.这项研究的目的是比较技术上的成功,经皮射频和微波消融治疗肾脏小肿块的主要疗效和并发症发生率。回顾性分析2017年12月至2022年1月期间接受射频或微波消融治疗的肾脏小肿块患者。3个月后,通过对比增强计算机断层扫描检查评估对消融治疗的反应。43例患者进行了44例肾脏病变的消融。射频治疗16个病灶,微波消融治疗28个病灶。两种方法均具有较高的技术成功率(100%)。射频和微波消融的主要有效率分别为81.3%和89.3%,分别。仅在微波消融治疗的患者中发现消融相关并发症(18.5%),所有这些都是低等级的(Clavien-Dindo1和2)。射频和微波消融在治疗小肾脏肿块方面具有相当的疗效。微波消融与相对较高数量的并发症相关。
    Although the gold standard in the management of kidney tumors is surgical treatment, thermal ablation methods are a viable therapeutic option for patients with small (<4 cm) renal masses who are poor surgical candidates. The aim of this study was to compare the technical success, primary efficacy and complication rate of percutaneous radiofrequency and microwave ablation in the treatment of small renal masses. A retrospective analysis of consecutive patients with small renal masses treated with radiofrequency or microwave ablation between December 2017 and January 2022 was conducted. Response to the ablative therapy was assessed on contrast-enhanced computed tomography examination after 3 months. Ablations of 44 kidney lesions were performed in 43 patients. Sixteen lesions were treated with radiofrequency and 28 with microwave ablation. Both methods were associated with high technical success (100%). Primary efficacy rates of radiofrequency and microwave ablation were 81.3% and 89.3%, respectively. Ablation-related complications were noted only in the patients treated with microwave ablation (18.5%), all of them being low grade (Clavien-Dindo 1 and 2). Radiofrequency and microwave ablation exhibited comparable efficacy in the treatment of small renal masses. Microwave ablation was associated with a comparatively higher number of complications.
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  • 文章类型: Journal Article
    目的:微波消融(MWA)和常规经动脉化疗栓塞(cTACE)是通常在早期进行的局部治疗,早期和中期的肝细胞癌(HCC)。尽管结合局部方法在获得完全肿瘤坏死方面显示出令人鼓舞的结果,它们在单个会话中的应用描述不佳。我们的目的是评估单次MWA和cTACE治疗5-cmHCC的安全性和有效性及其对肝功能的影响。
    方法:回顾性记录和分析2020年1月至2022年12月在我们的介入放射科接受MWA和cTACE单次治疗的所有5-cm肝癌。排除治疗前后影像学差或缺失的患者。技术上的成功,临床成功,并将并发症发生率作为主要终点.还评估了治疗前和治疗后的肝功能实验室参数。
    结果:共15个病灶(平均病灶直径,5.0±1.4cm),15例患者(11例男性;平均年龄,67.1±8.9年)进行回顾性评估。技术和临床成功率分别为100%和73%,分别。记录了4例(27%)部分反应的病例,没有进展或稳定的病例。已发现AST和ALT值在治疗后实验室测试中显著较高。没有记录治疗前和治疗后实验室值之间的其他显着差异。AST和ALT治疗前后较高的差异(ΔAST和ΔALT)与较低的临床成功率显着相关。
    结论:MWA和cTACE单次治疗对5-cm肝癌是安全有效的,无明显肝功能损害。治疗后AST和ALT值的增加可能是临床失败的预测因子。
    OBJECTIVE: Microwave ablation (MWA) and conventional transarterial chemoembolization (cTACE) are locoregional treatments commonly performed in very early, early and intermediate stages of hepatocellular carcinoma (HCC). Despite combined locoregional approaches have shown encouraging results in obtaining complete tumor necrosis, their application in a single session is poorly described. Our aim was to evaluate the safety and efficacy of single-session MWA and cTACE treatment in 5-cm HCCs and its influence on liver function.
    METHODS: All 5-cm HCCs treated by MWA and cTACE performed in a single-session in our Interventional Radiology unit between January 2020 and December 2022 were retrospectively recorded and analyzed. Patients with poor or missing pre- and post-treatment imaging were excluded. Technical success, clinical success, and complications rate were examined as primary endpoints. Pre- and post-treatment liver function laboratory parameters were also evaluated.
    RESULTS: A total of 15 lesions (mean lesion diameter, 5.0 ± 1.4 cm) in 15 patients (11 men; mean age, 67.1 ± 8.9 years) were retrospectively evaluated. Technical and clinical success were 100% and 73%, respectively. Four (27%) cases of partial response and no cases of progressive or stable disease were recorded. AST and ALT values have found to be significantly higher in post-treatment laboratory tests. No other significant differences between pre- and post-treatment laboratory values were registered. AST and ALT pre- and post-treatment higher differences (ΔAST and ΔALT) were significantly associated with a lower clinical success rate.
    CONCLUSIONS: MWA and cTACE single-session approach is safe and effective for 5-cm HCCs, without significant liver function impairment. A post-treatment increase in AST and ALT values may be a predictor for clinical failure.
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  • 文章类型: Journal Article
    本研究探讨了微波(MW)场下l-赖氨酸干预小麦面筋蛋白(WG)凝胶形成的机理。结果表明,在相同的升温速率下,MW处理具有较高的ζ电位值。加入L-赖氨酸后,溶液电导率和介电损耗显著增加。此外,在MW处理下,WG凝胶强度提高了4.40%。傅里叶光谱显示,随着赖氨酸的加入,α-螺旋含量降低了13.78%。紫外吸收光谱和荧光光谱表明,MW辐射比水浴加热更有效地影响WG分子之间的相互作用。促进蛋白质结构的变性和展开。此外,扫描电镜分析表明,赖氨酸的掺入促进了蛋白质有序网络结构的形成,这增强了凝胶特性。这表明1-赖氨酸的两性离子在MW场中蛋白质的聚集中起调节作用。
    This study explored the mechanism of l-lysine intervention in wheat gluten protein (WG) gel formation under a microwave (MW) field. The results showed that the MW treatment had higher ζ-potential values at the same heating rate. After adding l-lysine, the solution conductivity and dielectric loss were significantly increased. Moreover, the WG gel strength enhanced 4.40% under the MW treatment. The Fourier spectra showed that the α-helix content was decreased 13.78% with the addition of lysine. The ultraviolet absorption spectra and fluorescence spectra indicated that MW irradiation impacted the interactions between WG molecules more effectively than the water bath heating, promoting the denaturation and unfolding of the protein structure. In addition, scanning electron microscopy analysis showed that the incorporation of lysine promoted an ordered network structure formation of the protein, which enhanced the gel properties. This indicated that the zwitterion of l-lysine played a regulatory role in the aggregation of proteins in the MW field.
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  • 文章类型: Journal Article
    这项工作概述了从原始农业废料杏仁壳(AH)生产生物燃料前体糠醛(FF)的第一个微波(MW)辅助协议,橄榄石(OS),和酿酒衍生的葡萄茎(GS),葡萄渣(GM)和耗尽葡萄渣(EGM)通过一锅法合成。为了提高整体产量,催化过程首先是从木糖发展起来的,木质纤维素生物质中存在的半纤维素的主要成分。该方法提供了具有100%选择性的FF,当使用H2SO4时,分离产物的产率超过85%,而使用AlCl3·6H2O的产率为37%,在150°C下仅10分钟。对于这两种催化剂,所开发的方法得到了进一步验证,证明了从上述木质纤维素原料生产目标FF的适应性和有效性。更具体地说,AlCl3·6H2O的使用导致最高的选择性(来自GM的高达89%)和FF产率(来自OS和AH的42%和39%摩尔,分别),保持对后者的显著选择性(来自AH和OS的61%和48%)。在这方面,考虑到可持续性的环境因素,重要的是要指出AlCl3·6H2O相对于H2SO4的作用,从而减轻有害物质。这项研究通过可持续的实践为潜在的生物基化学品的开发提供了农业废物的重要管理,符合绿色化学和工艺强化原则。
    This work outlines the first microwave (MW)-assisted protocol for the production of biofuel precursor furfural (FF) from the raw agricultural waste almond hull (AH), olive stone (OS), and the winemaking-derived grape stalk (GS), grape marc (GM) and exhausted grape marc (EGM) through a one-pot synthesis process. To enhance the overall yield, a catalytic process was firstly developed from xylose, major constituent of hemicellulose present in lignocellulosic biomass. This method afforded FF with 100 % selectivity, yielding over 85 % in isolated product when using H2SO4, as opposed to a 37 % yield with AlCl3·6H2O, at 150 °C in only 10 min. For both catalysts, the developed methodology was further validated, proving adaptable and efficient in producing the targeted FF from the aforementioned lignocellulosic raw materials. More specifically, the employment of AlCl3·6H2O resulted in the highest selectivity (up to 89 % from GM) and FF yield (42 % and 39 % molar from OS and AH, respectively), maintaining notable selectivity for the latter (61 and 48 % from AH and OS). At this regard, and considering the environmental factor of sustainability, it is important to point out the role of AlCl3·6H2O in contrast to H2SO4, thus mitigating detrimental substances. This study provides an important management of agricultural waste through sustainable practises for the development of potential bio-based chemicals, aligning with Green Chemistry and process intensification principles.
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  • 文章类型: Journal Article
    传统的外场辅助疗法,例如,微波(MW)疗法和光疗,不能有效和最小的伤害消除深层感染,由于光的穿透性差和低活性氧(ROS)刺激能力的MW。在这里,可植入和无线供电的治疗平台(CNT-FeTHQ-TS),其中外部MW可以通过MW无线供电的发光芯片转换为内部光,旨在通过MW诱导的深层光动力疗法根除深层组织感染。在应用中,CNT-FeTHQ-TS植入内部病变处,芯片在外部MW照射下发光。随后,平台中的CNT-FeTHQ涂层可以同时响应MW和光,以产生ROS和MW热疗,从而在焦点处进行快速精确的灭菌。重要的是,MW还通过在FeTHQ中引入空位以促进光激发过程并改变电子的自旋状态以抑制光生电子-空穴对的络合,从而提高了CNT-FeTHQ的光动力学性能,通过模拟计算和原位MW辐照光致发光实验证实了这一点。在体内,CNT-FeTHQ-TS能有效治愈小鼠背部皮下组织金黄色葡萄球菌感染。这项工作克服了治疗深层感染的安全能量传输和转换的关键临床局限性。
    Traditional external field-assisted therapies, e.g., microwave (MW) therapy and phototherapy, cannot effectively and minimally damage eliminate deep-seated infection, owing to the poor penetrability of light and low reactive oxygen species (ROS) stimulation capability of MW. Herein, an implantable and wireless-powered therapeutic platform (CNT-FeTHQ-TS), in which external MW can be converted into internal light via MW wireless-powered light-emitting chips, is designed to eradicate deep-seated tissue infections by MW-induced deep-seated photodynamic therapy. In application, CNT-FeTHQ-TS is implanted at internal lesions, and the chip emits light under external MW irradiation. Subsequently, CNT-FeTHQ coating in the platform can respond to both MW and light simultaneously to generate ROS and MW-hyperthermia for rapid and precise sterilization at focus. Importantly, MW also improves the photodynamic performance of CNT-FeTHQ by introducing vacancies in FeTHQ to facilitate the photoexcitation process and changing the spin state of electrons to inhibit the complexation of photogenerated electron-hole pairs, which were confirmed by simulation calculations and in situ MW-irradiated photoluminescence experiments. In vivo, CNT-FeTHQ-TS can effectively cure mice with Staphylococcus aureus infection in dorsal subcutaneous tissue. This work overcomes the key clinical limitations of safe energy transmission and conversion for treating deep-seated infections.
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