Ultrasonics Sonochemistry最新文献

{"title":"Gold removal from e-waste using high-intensity focused ultrasound","authors":"Axi Holmström ,&nbsp;Topi Pudas ,&nbsp;Jere Hyvönen ,&nbsp;Martin Weber ,&nbsp;Kenichiro Mizohata ,&nbsp;Tom Sillanpää ,&nbsp;Joni Mäkinen ,&nbsp;Antti Kuronen ,&nbsp;Tapio Kotiaho ,&nbsp;Edward Hæggström ,&nbsp;Ari Salmi","doi":"10.1016/j.ultsonch.2024.107109","DOIUrl":"10.1016/j.ultsonch.2024.107109","url":null,"abstract":"<div><div>The demand for rare and precious metals (RPMs), e.g. gold, is increasing, as these are used in the ever-increasing amount of electronics needed for technological development and digitalization. Due to their rarity, virgin mining of RPMs is becoming more difficult and expensive. At the same time, over 62<!--> <!-->Mt of e-waste is created globally each year. The high concentration of gold and other RPMs in e-waste makes it an excellent source for recycling. Unfortunately, current recycling methods need to separate the different metals and the current pyrometallurgical and hydrometallurgical processes also create toxic pollutants, large amounts of wastewater and require highly corrosive substances. Here we present a new method for gold removal for the purpose of recycling, using only water and high-intensity focused ultrasound to induce material erosion through cavitation. An 11.8<!--> <!-->MHz ultrasonic transducer is used to first image the sample to locate gold-coated pads on discarded printed circuit boards (PCBs) and subsequently to remove only the gold layer. We demonstrate that the gold removal can be controlled by the number of transmitted ultrasonic bursts and that the energy efficiency is optimal when only minute amounts of the nickel layer beneath are also removed. Removing solely the gold layer also decreases the need for further processing steps. This greener gold removal method for e-waste is therefore well aligned with, and contributing to, the United Nations Sustainable Development Goal 12: Ensure sustainable consumption and production patterns.</div></div>","PeriodicalId":442,"journal":{"name":"Ultrasonics Sonochemistry","volume":"111 ","pages":"Article 107109"},"PeriodicalIF":8.7,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142492478","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Proof-of-concept for removing micropollutants through a combination of sub-atmospheric-pressure non-thermal plasma and hydrodynamic (super)cavitation","authors":"Mojca Zupanc ,&nbsp;Gregor Primc ,&nbsp;Matevž Dular ,&nbsp;Martin Petkovšek ,&nbsp;Robert Roškar ,&nbsp;Rok Zaplotnik ,&nbsp;Jurij Trontelj","doi":"10.1016/j.ultsonch.2024.107110","DOIUrl":"10.1016/j.ultsonch.2024.107110","url":null,"abstract":"<div><div>The persistence and toxicity of hazardous pollutants present in wastewater effluents require the development of efficient and sustainable treatment methods to protect water resources. In this study, the efficacy and efficiency of a novel combination of two advanced oxidation processes – sub-atmospheric-pressure plasma and hydrodynamic cavitation – were systematically tested for the removal of valsartan (VAL), sulfamethoxazole, trimethoprim, naproxen, diclofenac (DF), tramadol, propyphenazone, carbamazepine, 17β-estradiol (E2) and bisphenol A (BPA). The results show that both sample temperature and plasma power play a role and the highest removal, from 29–99 %, was achieved at 25 ℃ and 53 W of plasma power. E2, BPA, DF, and VAL were removed to the highest degree. These results are particularly important in the case of E2 and BPA, whose harmful environmental effects may start to occur already at sub-ng/L to µg/L levels. The differences in the removals obtained depend strongly on the physicochemical properties, and the compounds with the highest log<em>K</em>_OW were removed to the highest extent. The energy yield, in terms of plasma power, was between 1 and 26 mg/kWh under optimal experimental conditions. Our results show that the novel plasma-cavitation treatment shows potential that could prove valuable for upcoming regulatory requirements.</div></div>","PeriodicalId":442,"journal":{"name":"Ultrasonics Sonochemistry","volume":"111 ","pages":"Article 107110"},"PeriodicalIF":8.7,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142492482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identification of novel antifreeze peptides from yak skin gelatin ultrasound-assisted enzymatic hydrolysate","authors":"Xiaotong Ma ,&nbsp;Wenxing Wang ,&nbsp;Hongmei Shi ,&nbsp;Xiangying Kong ,&nbsp;Li Zhang","doi":"10.1016/j.ultsonch.2024.107102","DOIUrl":"10.1016/j.ultsonch.2024.107102","url":null,"abstract":"<div><div>In this paper, a new type of antifreeze peptide was identified from the ultrasonic-assisted enzymolysis product of yak skin. First, the antifreeze peptides were obtained by ultrasonic-assisted enzymolysis of yak skin gelatin. The obtained peptides with 150 W ultrasound treatment could increase the survival rate of <em>Lactobacillus plantarum</em> from 16 % to 60 % after four freeze–thaw cycles. Then, the component with the highest antifreeze activity in the peptides’ ultrafiltration product was analyzed by LC-MS/MS to obtain 961 peptides. After screening of antifreeze activity and physical properties, three antifreeze peptide sequences were obtained (S1: GERGGPGGPGPQ, S2: PGGAEGPGRDAQQP, S3: VAPPGAPKKEH). DSC analysis, <em>Lactobacillus plantarum</em> cryoprotection experiments and molecular docking showed that the S1 sequence had the best antifreeze activity. This study provides a new idea for the high-value utilization of yak by-products and a potential candidate for food antifreeze agents.</div></div>","PeriodicalId":442,"journal":{"name":"Ultrasonics Sonochemistry","volume":"111 ","pages":"Article 107102"},"PeriodicalIF":8.7,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142455177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of ultrasound-assisted Maillard reaction on functional properties and flavor characteristics of Oyster protein enzymatic hydrolysates","authors":"Zilong Zhao ,&nbsp;Wenduo Wang ,&nbsp;Jin Chen ,&nbsp;Jianxu Chen ,&nbsp;Jinying Deng ,&nbsp;Guixian Wu ,&nbsp;Chunxia Zhou ,&nbsp;Guili Jiang ,&nbsp;Jingjing Guan ,&nbsp;Donghui Luo","doi":"10.1016/j.ultsonch.2024.107113","DOIUrl":"10.1016/j.ultsonch.2024.107113","url":null,"abstract":"<div><div>To address the delamination phenomenon during storage and flavor characteristics of Oyster protein hydrolysates (OPH). In this study, <em>xylo</em>-oligosaccharides (XOS) were selected to covalently graft with OPH through ultrasound-assisted Maillard reaction, and the effect of ultrasound-assisted Maillard reaction on the structure, functional properties, and flavor characteristics of OPH were investigated. The results revealed that the ultrasound treatment led to a 1.46-fold increase in the degree of grafting compared with the conventional wet-heat Maillard reaction methods. Structural analyses at various levels indicated substantial alterations in the OPH structure following the ultrasound-assisted Maillard reaction. More ordered α-helical secondary structures were shifting to random coiling, the tertiary structure showed more stretching changes, and the surface structure was characterized by loose and porous features. Compared with OPH, the solubility of the ultrasound-assisted Maillard reaction products (OPH-U-M) increased from 54.67% to 70.14%, leading to a notable enhancement in storage stability. Flavor profile analysis demonstrated a decrease in unsaturated aldehydes and ketones presenting fishy and bitter aromas, while an increase in presenting meat aroma compounds was observed in OPH-U-M. Furthermore, OPH-U-M exhibited superior antioxidant properties with DPPH and ABTS radical scavenging abilities enhancing 46.05% and 42.09% in comparison with OPH, respectively. The results demonstrated that covalently binding with XOS under ultrasonication pretreatment endowed OPH with superior functional properties (including solubility, storage stability, and antioxidant activity), and the improvement of flavor profile. This study can provide theoretical guidance and practical implications for promoting the processing applications of oyster protein.</div></div>","PeriodicalId":442,"journal":{"name":"Ultrasonics Sonochemistry","volume":"111 ","pages":"Article 107113"},"PeriodicalIF":8.7,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142492414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fabrication of millet starch nanocapsules loaded with beta carotene using acid hydrolysis and ultrasonication: Characterisation, release behaviour and bioactivity retention","authors":"Mehak Nazir ,&nbsp;Faiza Jhan ,&nbsp;Asir Gani ,&nbsp;Adil Gani","doi":"10.1016/j.ultsonch.2024.107112","DOIUrl":"10.1016/j.ultsonch.2024.107112","url":null,"abstract":"<div><div>The acid hydrolysis process was used to create novel millet starch-based nanoparticles from three different sources: sorghum, foxtail millet and pearl millet. An environment-friendly, risk-free ultrasonication technique was used for encapsulating beta carotene in starch nanoparticles to create nanocapsules that will shield the bioactivity of beta carotene in gastrointestinal conditions and increase its accessibility after consumption. Formulated nanocapsules were examined for zeta potential, particle size and encapsulation efficiency. The particle dimensions of beta carotene-loaded sorghum (SSB), foxtail millet (FSB), and pearl millet (PSB) starch nanoparticles were 416, 399 and 587 nm with zeta potential of −17.98, −19.03 and –22.31 mV respectively. Encapsulation efficiencies of nanocapsules were found to be 85.83, 89.65 and 78.32 % for SSB, FSB and PSB respectively. Scanning electron microscopy (SEM) was also harnessed as a confirmatory tests towards the presence of beta carotene in nanocapsules. Beta carotene encapsulation in starch nanoparticles was also demonstrated using ATR-FTIR which revealed broad characteristic peaks at 3000, 1086 and 885 cm⁻¹ that occur without any discernible interaction. Intestinal juice with higher beta carotene content ensured controlled release in the intestine. Encapsulated beta carotene showed more bioactive properties in terms of antioxidant activity as compared to free beta carotene form.</div></div>","PeriodicalId":442,"journal":{"name":"Ultrasonics Sonochemistry","volume":"111 ","pages":"Article 107112"},"PeriodicalIF":8.7,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142492477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First applications of ultrasound technology in solid rocket propellant combustion promotion","authors":"Zhan Wen ,&nbsp;Heng Jing ,&nbsp;Feng Hao ,&nbsp;Yuheng Wang ,&nbsp;Bicheng Kuang ,&nbsp;Peijin Liu ,&nbsp;Wen Ao","doi":"10.1016/j.ultsonch.2024.107107","DOIUrl":"10.1016/j.ultsonch.2024.107107","url":null,"abstract":"<div><div>The regulation of propellant combustion using ultrasonic waves is proposed. Under ultrasonic frequencies of 25–40 kHz, we systematically examined the combustion characteristics of Al particles, ammonium perchlorate (AP)/hydroxyl-terminated polybutadiene (HTPB) propellants, and Al-containing Al/AP/HTPB propellants. Ultrasonic treatment increased the ignition delay time of the Al particles by 48.3 %. However, it increased the burning rate of the AP/HTPB propellants by up to 26.1 % and decreased their ignition delay by 39.3 %. As the ultrasonic frequency increased, the burning rate of the solid Al/AP/HTPB propellants increased by 22.5 %, and the degree of Al agglomeration decreased, resulting in a 24 % decrease in the size of the condensed-phase combustion products. The action mechanism was analyzed in terms of the effects of ultrasonic waves on Al droplets and combustion flames. The introduction of ultrasonic waves split the Al droplets near the burning surface into smaller particles, which affected combustion efficiency. Bringing the diffusion flame closer to the burning surface affected the burning rate. These findings demonstrate that the combustion and agglomeration characteristics of solid propellants can be modified using ultrasonic techniques, providing a new method for controlling the thrust of solid rocket motors.</div></div>","PeriodicalId":442,"journal":{"name":"Ultrasonics Sonochemistry","volume":"111 ","pages":"Article 107107"},"PeriodicalIF":8.7,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142446940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Progress in application of nanomedicines for enhancing cancer sono-immunotherapy","authors":"Hongxin Zhao,&nbsp;Fangxue Du,&nbsp;Xi Xiang,&nbsp;Yuanjiao Tang,&nbsp;Ziyan Feng,&nbsp;Ziyao Wang,&nbsp;Xiao Rong,&nbsp;Li Qiu","doi":"10.1016/j.ultsonch.2024.107105","DOIUrl":"10.1016/j.ultsonch.2024.107105","url":null,"abstract":"<div><div>Cancer immunotherapy has significant potential as a cancer treatment since it boosts the immune system and prevents immune escape to get rid of or fight cancers. However, its clinical applicability is still limited because of the low response rate and immune-related side effects. Recently ultrasound has been shown to alter the tumor immune microenvironment, enhance the effectiveness of other antitumor therapies, and cause tumors to become more sensitive to immunotherapy, thus providing new insights into cancer treatment. Nanomedicines are also anticipated to have a positive impact on improving the immunological effects and enhancing ultrasound effect for cancer therapy. Therefore, designing effective nanomedicines enhanced ultrasound effect for augmenting sono-immunotherapy has been a pivot on anticancer therapy. In this review, the immunological impacts of various ultrasound therapeutic modalities, ultrasound parameters, and their underlying mechanisms are discussed. Moreover, we highlight the recent progress of nanomedicines synergistically enhancing sono-immunotherapy. Finally, we put forward opportunities and challenges on sono-immunotherapy.</div></div>","PeriodicalId":442,"journal":{"name":"Ultrasonics Sonochemistry","volume":"111 ","pages":"Article 107105"},"PeriodicalIF":8.7,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142455192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimizing degassing for particle-reinforced Al composite: Advanced ultrasonic-assisted argon treatment and numerical simulation insights","authors":"Jian Chen ,&nbsp;Xinyuan Jin ,&nbsp;Jiwei Geng ,&nbsp;Xianhui Luo ,&nbsp;Yugang Li ,&nbsp;Peikang Xia ,&nbsp;Xianfeng Li ,&nbsp;Fangming Wang ,&nbsp;Dong Chen ,&nbsp;Mingliang Wang ,&nbsp;Haowei Wang","doi":"10.1016/j.ultsonch.2024.107092","DOIUrl":"10.1016/j.ultsonch.2024.107092","url":null,"abstract":"<div><div>Hydrogen removal from particle-reinforced Al composite is critical for preventing porosities near particle clusters and improving comprehensive material properties. This study investigated the effects of different argon flow schemes and power ultrasound on bubble dispersion in water. Based on similarity theory, the optimal argon flow scheme for ultrasonic-assisted argon (UAA) treatment was identified and applied to TiB₂/2024 Al composite to explore the degassing mechanism. Three argon flow schemes for UAA treatment: EV-EC (External ventilation, equal channel), IV-EC (Internal ventilation, equal channel), and IV-RC (Internal ventilation, reduced channel) were evaluated through numerical simulation and water simulation experiments. The results demonstrated that IV-RC scheme exhibits superior bubble dispersion characteristics and a broader bubbling range. Experimental results in Al composite confirmed that UAA treatment with IV-RC scheme achieved the highest degassing efficiency, with a relative density improvement of up to 98.01 % and the lowest hydrogen content (0.0235 ppm). Synchrotron radiation X-ray computed tomography results indicated that UAA treatment effectively reduces the pore size and volume, transforming interconnected, complex pores into dispersed, nearly spherical ones. Ultrasonic cavitation aids this process by breaking small argon bubbles into numerous tiny bubbles that penetrate deeply into the melt, reducing the wettability angle between particles and the matrix and thereby improving hydrogen removal efficiency.</div></div>","PeriodicalId":442,"journal":{"name":"Ultrasonics Sonochemistry","volume":"111 ","pages":"Article 107092"},"PeriodicalIF":8.7,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142455191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of ultrasonic probe type, frequency, and static pressure on large-scale graphene exfoliation","authors":"Minhui Gao ,&nbsp;Hu Zong ,&nbsp;Lei Yu ,&nbsp;Jiacheng Yao ,&nbsp;Su Zhao ,&nbsp;Ying Zhou ,&nbsp;Yifei Li ,&nbsp;Yanyuan Zhou ,&nbsp;Jiahao Zhang ,&nbsp;Ronghe Li","doi":"10.1016/j.ultsonch.2024.107103","DOIUrl":"10.1016/j.ultsonch.2024.107103","url":null,"abstract":"<div><div>The ultrasonic liquid phase exfoliation method has emerged as an essential research direction for graphene preparation due to its cost-effectiveness and ability to minimize defects. However, this method faces challenges related to processing throughput when scaled up for industrial production. In this study, industrial grade ultrasonic homogenizers with different frequencies and probe types were evaluated for the preparation of FLG. In each experiment, 1.5 kg of graphite slurry was treated using a cyclic ultrasonic system. The results demonstrated that the 25 kHz dumbbell probe produced the thinnest FLG with the lowest defect density. Moreover, applying a static pressure of 0.2 MPa in the cycle system enhanced the cavitation-induced exfoliation of graphite sheets, effectively reducing the layer count and distribution range of FLG. This method improves the conductivity while minimizing defect density.</div></div>","PeriodicalId":442,"journal":{"name":"Ultrasonics Sonochemistry","volume":"111 ","pages":"Article 107103"},"PeriodicalIF":8.7,"publicationDate":"2024-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142446941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing salt-induced gelation of egg yolk granules through pH-ultrasound combined treatment: A physicochemical and microstructural analysis","authors":"Dan Zheng ,&nbsp;Danrong Yu ,&nbsp;Shuai Lin ,&nbsp;Liting Ji ,&nbsp;Yaogui Sun ,&nbsp;Chunyou Liu ,&nbsp;Xiaoyu Zhang ,&nbsp;Zhihui Yu","doi":"10.1016/j.ultsonch.2024.107101","DOIUrl":"10.1016/j.ultsonch.2024.107101","url":null,"abstract":"<div><div>Salted duck eggs are a popular food product, but their high salt content and uneven salt distribution can reduce acceptability. This study investigated the effects of pH-high-intensity ultrasound combined treatment on the salt-induced gelation properties of egg yolk granules. The results showed that the pH5 + 150 W treatment group exhibited the best physical and gelation properties, with the smallest particle size (1597.33 nm), optimal dispersibility (PDI 0.29), and good stability. The gelation properties of this group also demonstrated excellent springiness (0.30 mm), cohesiveness (0.56), and gumminess (0.05 N). Furthermore, the pH5 + 150 W group had the highest water holding capacity of 97.42 % and relatively high hydrophobicity (173.39 μg). Notably, it also showed high oil exudation (2.83 %) and good sandiness (62.07 %). The pH5 + 150 W led to a significant redshift of the fluorescence peak at 335 nm and an enhancement of the peak intensity at 562 nm compared to the control group. Structural characterization revealed a more ordered protein structure and a uniform gel structure with enhanced electrostatic repulsion between oil droplets. Secondary structure analysis of the proteins showed a significant reduction in α-helix and β-sheet, while β-turn and random coil increased. In summary, the pH5 + 150 W treatment displayed the best gelation properties, providing theoretical guidance for enhancing the processing performance of yolk and expanding their application in the food industry.</div></div>","PeriodicalId":442,"journal":{"name":"Ultrasonics Sonochemistry","volume":"111 ","pages":"Article 107101"},"PeriodicalIF":8.7,"publicationDate":"2024-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142446942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}