Paulownia hybrid for the uptake and transport of 67 elements along with the physiological response of plants cultivated in highly contaminated post-industrial wastes  was investigated. Biochar (BR) was added to substrates to limit metal mobility and facilitate plant survival. Paulownia could effectively uptake and translocate B, Ca, K, P, Rb, Re and Ta. Despite severe growth retardation, chlorophyll biosynthesis was not depleted, while an increased carotenoid content was noted for plants cultivated in waste materials. In Paulownia leaves and roots hydroxybenzoic acids (C6-C1) were dominant phenolics, and hydroxycinnamic acids/phenylpropanoids (C6-C3) and flavonoids (C6-C3-C6) were also detected. Plant cultivation in wastes resulted in quantitative changes in the phenolic fraction, and a significant drop or total inhibition of particular phenolics. Cultivation in waste materials resulted in increased biosynthesis of malic and succinic acids in the roots of FT-cultivated plants, and malic and acetic acids in the case of MS/BR substrate. The obtained results indicate that the addition of biochar can support the adaptation of Paulownia seedlings growing on MS, however, in order to limit unfavorable changes in the plant, an optimal addition of waste is necessary.The potential of the  Paulownia includes mainly herbs with only a few woody plants. Fast-growing, deciduous trees of this genus naturally occur in Southeast Asia, but some species have been successfully introduced in Poland and can be found in the warmest areas in the country, i.e., Paulownia tomentosa (Thunb.) Steud. (known as the princess tree) and Paulownia fortunei (Seem.) Hemsl. . Both of them grow up to 20 m tall, and their crowns are typically spherical-shaped. The Paulownia tree is difficult to propagate since its seeds are highly vulnerable to soil fungi. Therefore, in vitro reproduction techniques are implemented to produce seedlings. To maximize the advantages of various species, some new artificial species and their varieties have been developed, e.g., Paulownia “Shan Tong” and Paulownia “Cotta Vista 2” (Paulownia tomentosa and Paulownia fortunei hybrid) [Paulownia Clon in Vitro 112 (Paulownia elongata × fortunei hybrid) developed by the Spanish In Vitro S.L. company. Trees of the latest clone assimilate more CO2 than other taxa of the Paulownia genus, and consequently produce more O2, earning them the name of “Oxytree”, a commercial name given by Carbon Solutions Global Ltd. in 2016 [Paulownia plantations have become increasingly popular [The genus  hybrid) , Paulown popular .Paulownia genus are usually described as good candidates for phytoremediative purposes due to their tolerance to high concentrations of metals, rapid growth, and above all, high biomass production [Paulownia may be suitable for metal phytoextraction due to their belonging to the C4 plant group, whose highly reductive internal environment of cells prevents the oxidative conversion of metals [Paulownia elongata × fortunei hybrid showed good resistance and reduced the Cu content in the soil by 17% [Paulownia [Paulownia has so far only been investigated to a limited extent on mining waste materials and there is lack of extensive research on the accumulation of noble or rare earth elements. However, bioconcentration and translocation factors exceeding one for common metallic pollutants as Cd, Cu, Pb and Zn, make Paulownia an increasingly attractive research subject [Paulownia fortunei.Along with poplar and willow, plants of the oduction . This asoduction ,6,7. Tref metals . As partl by 17% . It was l by 17% . Attentiaulownia ,11. Furt subject . Wang et subject  showed tPaulownia tomentosa, almost 2-fold higher than for Cytisus scoparius or Populus alba was documented [Paulownia was also described [Paulownia is clearly limited due to non-native trees are now prominently on the lists of invasive plants in many parts of the world [Paulownia genus can be seen in hybrids such as Paulownia elogata × fortunei that produce non-viable seeds and limiting the invasion risks [An effective reduction of metal load in soil using cumented . The higescribed  with clehe world . Possibion risks .Plant growth on contaminated soil is already problematic at the adaptation stage when the plant experiences contact with high concentrations of toxic elements. A promising solution undertaken in several works is the use of biochar. Many studies have reported that biochar has been effectively used to immobilize metal(loid)s in contaminated soils and influences their bioavailability and bioaccessibility for plants ,18. BiocThe search for plants capable of adaptation and growth on post-industrial waste is necessary due to the need for the decontamination of polluted matrices and their use in phytomining. The use of species recognized at present as invasive, although in the context of progressive climate change potentially non-invasive species in the future, seems rational, providing these plants are characterized by high resistance and accumulation of pollutants while growing on waste with moderate concentrations of toxic elements.Paulownia elongata × Paulownia fortunei hybrid to uptake 67 elements (including rare earth elements (REEs) and noble elements (NEs) together with an estimation of the physiological response of plants cultivated in highly contaminated post-industrial waste materials. Due to the high concentrations of metals and metalloids in the applied waste materials, biochar was used to assess its use as a factor limiting metal mobility and availability for plants, and ultimately facilitating the survival of Paulownia seedlings.The aim of this study was to characterize the potential of the Paulownia elongata S. Y. Hu × Paulownia fortunei (Seem.) Hemsl.) seedlings with the trade name of in Vitro 112, were obtained from an authorized supplier, Oxytree Solutions Poland Ltd. (formerly Carbon Solutions Poland Ltd.). Seedlings (6–8-month-old) were used after their preliminary selection from a population of 10,000 specimens according to similar biomass (14–16 g), height (15 cm) and leaf count (5 pcs).Oxytree (Miscanthus gigantheus). The lignocellulosic material was ground with a roller mill and sieved. The crushed plants were subjected to pyrolysis and carbonization in a chamber reactor in an oxygen free atmosphere by heating up to 600 °C at the temperature rate of 3 °C min−1 and then holding for 1 h. The pore structure of the biochar was characterized by the nitrogen adsorption-desorption method at 77.4 K in a sorptometer ASAP Micromeritics 2020. Prior to gas adsorption measurements, the biochar was degassed at 300 °C in a vacuum condition for 24 h. The Brunauer-Emmett-Teller (BET) surface area was calculated from the isotherms using the BET equation. The pH of the aqueous biochar solution was also determined. The mixtures of waste materials and BR (characterized by the specific surface area of 50.1 m2 g−1) were carefully blended using a POLYMIX PX-SR 90 D stirrer . Detailed characteristics of the resulting experimental substrates are shown in Tables 1 and 2 in the Results section.Five experimental systems were prepared in hydroponic pots  as follows: (1) control—6.1 kg of reference soil, (2) FT—4.2 kg of flotation tailings, (3) FT/BR—3.99 kg of FT and 0.21 kg of biochar (BR), (4) MS—4.6 kg of mining sludge and (5) MS/BR—4.37 kg of MS and 0.23 kg of BR. Biochar addition was set at 5% (w/w) based on preliminary trials where its application increased the porosity of waste materials and eventually led to undisturbed water flow in the substrate. Biochar was obtained from miscanthus  and divided into roots, stems and leaves. The biomass of separated organs was determined by weighing. For physiological and biochemical investigations, fresh organs were in situ frozen in liquid nitrogen and stored at −80 °C till analyses. Before extraction, each plant sample was homogenized in liquid nitrogen. For the elemental investigations, collected tissue was dried at 55 ± 2 °C to a constant weight using an electric oven . The dry material was ground using an SM 200 Cutting Mill  until a powder fraction was obtained. The remaining 3 plants from each group were left for the next growing season (2019), and the harvested plants were investigated for biomass parameters and metal accumulation.HA), fulvic acids (CFA) and humins (CHUMIN) were determined according to Kononowa [2+, Mg2+, K+, Na+) were determined by an inductively coupled plasma optical emission spectrometer  following the extraction with 1 M ammonium acetate. Cation exchange capacity (CEC) and base cation saturation ratio were calculated according to Culman et al. [Substrate samples were air dried and sieved through a 2 mm sieve. Particle size distribution was performed with the laser diffraction method using the Laser Particle Sizer ANALYSETTE 22 . pH was analyzed in a 1:2.5 substrate-water suspension using a Hanna Instruments  4221 pH-meter. Electrical conductivity (EC) was analyzed in a 1:5 substrate-water suspension with a HI 2316 EC-meter by Hanna Instruments . Total carbon (TC), nitrogen (Nt) and sulfur (St) were determined by the dry combustion method using the auto analyzer Vario El CUBE  . Soil orIn the experimental substrates and plant organs, 67 elements were analyzed as follows: Al, As, B, Ba, Be, Bi, Ca, Cd, Co, Cr, Cs, Cu, Fe, Ga, Ge, Hf, Hg, In, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, Rb, Re, Sb, Se, Si, Sn, Sr, Ta, Te, Th, Ti, Tl, V, W, Zn, Zr, rare earth elements (REEs): Ce, Dy, Er, Eu, Gd, Ho, La, Lu, Nd, Pr, Sc, Sm, Tb, Tm, Y and Yb and noble elements (NEs): Ag, Au, Ir, Pd, Rh, Ru, Os, Pt.Step 1—Exchangeable/extractable fraction (F1): 40 mL 0.11 M acetic acid was added to a 100 mL centrifuge tube containing 1 g of dry soil sample and sieved through a 2-mm grid. The samples were then shaken at room temperature for 16 h. The supernatant and solid were decanted and kept for further analysis. The residual solid was rinsed twice with distilled water (2 × 10 mL) by shaking for 15 min. After centrifugation, the liquid was decanted and discarded.Step 2— Reducible fraction bound Fe–Mn oxides (F2): 40 mL 0.5 M hydroxyloammonium chloride solution was added to the centrifuge tube containing the residue from step 1. The samples were shaken once more at room temperature for 16 h. The samples were then centrifuged and treated as in step 1.Step 3— Oxidizable fraction bound to organic matter (F3): 10 mL 8.8 M hydrogen peroxide solution was added to the Step 2 residue. The contents were digested first at room temperature for 1 h, then at 85 °C in a water bath until approximately 1 mL of solution was obtained. Then 50 mL 1 M ammonium acetate was added and shaken for 16 h at room temperature. The supernatant was collected after centrifugation and kept for further analysis. The solid was rinsed as before.Step 4— Residual fraction (F4): The residue remaining at the end of step 3 was digested in aqua regia solution and the concentration of REEs was determined using an inductively coupled plasma optical emission spectrometer .For the fractionation of elements in all experimental substrates, the four steps sequential extraction proposed by the Commission of the European Communities Bureau of Reference (BCR) procedure  was perf−1 DW.Samples of dry material (0.300 ± 0.001 g) were digested with concentrated nitric acid  in Teflon containers using a closed microwave sample preparation system . After digestion, the samples were diluted with Milli-Q water  to a final volume of 15 mL and filtered . Concentration of all determined elements is expressed as mg kg−1, respectively for nebulizer gas, auxiliary gas and plasma gas flows; detector charge coupled device (CCD) temperature −40 °C; the time of signal accusation 5 s for 3 replicates. The detection limit for all elements determined was set (as 3-sigma criteria) at the level of 0.01–0.09 mg kg−1 of dry weight (DW). The uncertainty for the total analytical procedure  was at the level of 20%. The recovery for certified reference materials analysis  was acceptable (80–120%) for most of the determined elements.The inductively coupled plasma optical emission spectrometry  was used for analysis. The following conditions of analytical procedure were set: radio frequency (RF) power 1.2 kW; 0.7, 1.0 and 12.0 L minDry samples (0.300 ± 0.001 g) were extracted in a glass flask with 10 mL of phosphoric acid (1 M) in an ultrasonic bath for 30 min. Next, the solution was diluted with water to a final volume of 10 mL and filtered using filter paper.−1 of phosphate buffer (5 mM Na2HPO4 and 50 mM KH2PO4 × 2H2O) and an injection volume of 200 µL. PEEK (polyetheretherketone) tubing was inserted into a Tygon sleeve for transfer of the eluent from the LC column to the in-spray chamber of the hydride generation unit . The concentration of NaBH4 was 1% in 1% NaOH, the concentration of HCl was 5 M . An inductively coupled plasma optical emission spectrometer Agilent 5110 ICP-OES  was used for signal detection with the parameters listed above. As an analytical signal, the peak height corrected by the noise level was used. The limits of quantification were 6, 18, 21 µg L–1 for As(III), DMA, and As(V), respectively. Due to a lack of certified reference materials for arsenic speciation in the analyzed matrix, the standard addition method was used for accuracy and traceability studies. Recovery at the level of 80–120% was found as satisfactory.The following arsenic species: inorganic As(III), As(V) and dimethylarsenic (DMA) were determined using high performance liquid chromatography with hydride generation optical emission spectrometry detection (HPLC-HG-ICP-OES). The HPLC instrument was a liquid chromatograph  with an anion-exchange column  LC-SAX1 (250 × 4.6 mm). The chromatographic elution was isocratic with a flow rate of 1 mL minA detailed description of the equipment, reagents, analytical procedure and obtained metrological data has been presented in previous work .Pigment content was assayed in methanolic extracts with colorimetric method . ApproxiLeaf samples of ~0.5 g were ground in liquid nitrogen and extracted with 6 mL of 80% methanol. Extracts were centrifuged , and the obtained supernatant was used for the total phenolic content (TPC) and relative antioxidant activity assays.2CO3 (2 mL) was added. Following incubation in a dark , the absorbance at λ = 765 nm was measured using a Varian Cary 300 Bio UV-Visible scanning spectrophotometer. The results were expressed as mg of gallic acid equivalents (GAE) per g of tissue fresh weight (mg GAE g−1 FW). The assay was performed in triplicate. Folin–Ciocalteu reagent was employed in order to determine the TPC in methanolic extracts . The extThe relative antioxidant activity of methanolic extracts was measured based on their scavenging activity towards a DPPH radical using a Cary 300 Bio UV-Vis spectrophotometer . The reacA is the absorbance of the control; eA is the absorbance of the extract.Paulownia leaves were ground in liquid nitrogen using a mortar and a pestle to obtain a fine powder and ~0.50 g was taken for analysis. SA was extracted twice with methanol (90% followed by a straight solvent) and each time sonicated for 15 min. After centrifugation , the supernatants were combined, and the solvent was evaporated to dryness under a stream of nitrogen . Dry extracts were redissolved in 3 mL of TCA  for pigment precipitation and centrifuged . SA was extracted from the aqueous phase three times with a mixture of ethyl acetate, cyclopentane and isopropanol . The organic phases were combined, and the solvent was evaporated to dryness under a stream of nitrogen. Dry extracts were stored at −24°C until analyses. Before analysis, dry residues were dissolved in the mobile phase  and analyzed with a Waters Alliance 2695 Chromatograph coupled with a Waters 2475 Multi-λ Fluorescence Detector . The separations were performed using a Waters Spherisorb ODS2 column  at a 1.5 mL min−1 flow rate. The fluorometric detection was performed at λEx = 295 and λEm = 405 nm. SA was identified according to the retention time and quantified by comparing the peak area using an appropriate calibration curve.The contents of salicylic acid (SA) in leaves was determined with a HPLC-FLD method ,29. Paul−1. The quantification was conducted at λ = 280 and 320 nm for LMWOAs and phenolic compounds, respectively .Rhizosphere, root and leaf sample preparation for phenolic acids and low-molecular-weight organic acids (LMWAOs) analyses was carried out . The samAll statistical analyses were performed using STATISTICA 13.3 software . To show the existence of uniform groups of objects (α = 0.05), the multiple comparison Tukey’s HSD test was performed following one-dimensional analysis of variance (ANOVA).Paulownia, the bioconcentration factor (BCF) was calculated. It is the ratio of particular elements or their groups  concentration in plant organs  to their concentration in soil. Additionally, to characterize the effectiveness of element transport from the root system to aerial plant parts, the translocation factor (TF) was calculated as the ratio of studied elements/groups of elements concentration in leaves and stem to their concentration in roots [Paulownia, a Metal Extraction Ratio (MER) was calculated [plant is the element concentration in the harvested organs of the plant (stems and leaves), mplant is the biomass of harvestable organs produced in one harvest, csoil is the element concentration in the experimental system, and mrootzone is the soil mass rooted by the plant during studies.To define the effectiveness of element uptake by in roots ,32. To plculated ,34. The lculated , and is The plant effective number (PEN) was calculated to estimate, how many plants are needed to extract 1 g of determined elements from the substrate, taking into account the biomass of the above-ground organs ,36.−1) , slightly acidic (pH = 5.39), low salinity (EC = 0.27 mS) and low cation exchange capacity (CEC = 22.6 meq 100 g−1) . Compare−1) .t, St compared to other variants  were characterized by an alkaline reaction with a pH ranging from 7.94 for MS/BR to 8.49 for FT/BR , which rvariants . The res−1 and was ~165 fold higher than FT  . For FT,In the first year, plant height reached 34.4 cm for the control and 25.9, 25.4 and 23.6 cm for the FT, FT/BR and MS/BR systems, respectively A. In theIn the first year of cultivation, plants suffered no visible leaf damage resulting from applied waste materials. In contrast, in the second year, leaf necrosis and chlorosis, along with root thinning, was observed for plants cultivated in FT/BR .Depending on the variant, a specific distribution of individual elements was found . After tIn the second year of studies, both control plants and plants cultivated in flotation tailings (FT and FT/BR) were characterized by effective uptake to roots observed for the majority of elements, and to a different extent, to leaves. Effective accumulation in the stem was limited to selected elements, i.e., As, Bi, Cd, Co, Cs, Hg, Rb, Sn, Ta and W.BCF and TF values higher than 1 were calculated for B, Ca, K, P, Rb, Re and Ta . EffectiConsidering metal accumulation per plant, the highest content of the majority of elements was determined for MS/BR (2018), and in the case of B, Ca, Cu, In and Si, for the control (2018 and 2019). Further, despite significant differences in Be and Bi content in substrates, their accumulation was strongly inhibited and found to be at a similar level .In the second year of the study, the similarities and differences between the control plants and FT and FT/BR were less visible. Content of REEs and also Al, As, B, Cu, K, Mn, Na, Ni, Sb, Se, Tl, V, Zn and Zr were similar in the control and seedlings growing under FT. It was also observed that BR addition to FT substrate modified metal concentration on plant biomass. Compared to the FT substrate plants growing on the FT/BR substrate had a significantly lower concentration per plant of most of the analyzed elements. This trend was observed in both 2018 and 2019.Paulownia hybrid with respect to polluted substrates enriched or not with biochar. For this reason, MER values were calculated to show the % of elements removed from the control and especially polluted substrate during one harvest. Values higher than 0.001% and in at least one experimental system are shown in Estimation of the uptake of particular elements using BCF or their transport from roots to shoots using TF does not explain the extraction ability of the studied PEN calculations for individual elements showed that for the extraction of 1.0 g of a particular metal from the substrate a different number of plants was needed depending on the experimental system. The lowest PEN values were calculated for Ca, K, Mg, Na, P and Fe, which is a common observation due to the role of these metals in plant growth and development .The highest PEN values were observed for Be, Li and V. Promising values regarding practical aspects were noted for NE, Al, B, Ba, Cs, Cu, Mn, Pb, Si and Sr remediation, where several dozen to several hundred plants are needed to extract 1.0 g of the mentioned elements.Substrate modification did not cause any significant changes in chlorophyll content . SimultaPaulownia leaves, clearly marked for plants cultivated in FT and MS/BR  (Substrate modification led to a significant decrease of the phenolic fraction in ctively) . Furtherctively) .In the leaves and roots of control plants C6-C1 (hydroxybenzoic acids), C6-C3 (hydroxycinnamic acids/phenylpropanoids) and C6-C3-C6 (flavonoids) were assessed .p-coumaric, chlorogenic, ferulic, sinapic acids). Among flavonoids, rutin, quercetin and catechin were detected at relatively lower levels.In leaves, the dominant group was C6-C1 structures represented by 2,5-DHBA > 3,4-DHBA (protocatechuic) > 4-HBA > gallic acid. Other hydroxybenzoic acids  were present in smaller amounts. The sum of C6-C1 was ~3-fold higher than the C6-C3 and C6-C3-C6 phenolics, and among phenylpropanoids, ferulic acid was a dominant compound. Other hydroxycinnamic acids were detected in lower amounts  aimed to increase the chances of plants adapting to new, unfavorable growth conditions. Adsorption on biochar particles because of the alkaline pH (10.0) was a factor limiting the rapid increase in the concentration of toxic elements in the rhizosphere and ultimately facilitating the growth of seedlings. The use of biochar with respect to active carbons seems to be more justified because it is not about highly effective sorption but limiting the sudden increase in the concentration of metals negatively affecting plant growth, especially at the beginning of the phytoextraction process.Moreover, excessive compaction of these wastes can also result in a disturbance of air conditions, which in turn cause significant obstruction or inhibition of growth. In poor ventilation conditions, plants may show a deficiency of nutrients, even with their high concentration in the substrate. Additionally, more toxic elements like As, Pb and Cd are strongly associated with fine fractions, which can also influence their bioavailability . In the Paulownia biomass, which was clearly observed when comparing the FT and FT /BR substrate both in 2018 and 2019. Most of the analyzed elements were significantly lower in the biomass of plants growing on FT / BR substrate compared to the FT substrate, which clearly indicates the influence of biochar on the reduction of the bioavailability of elements. This fact may suggest that even a small addition of biochar with a small specific surface may significantly affect the behavior of Paulownia.However, in our study, biochar did not significantly affect the investigated physicochemical properties, disregarding the bioavailable forms of selected elements in the F1 fraction, which decreased in FT/BR and MS/BR substrates compared to pure waste materials. The reduction of the F1 fraction of the analyzed elements resulted in a decrease in the content of the analyzed elements in the Paulownia proved its high resistance to elevated concentrations of toxic elements in cultivation substrates such as mining waste materials. However, a drop in temperature below 0 °C for several days in January 2019 could have caused an aggravation of substrate-derived stress and consequently led to the death of plants cultivated in the most polluted MS/BR. Moreover, seedlings exposed to MS were unable to grow, and a possible cause of their withering could be an extremely high concentration of DMA (42.4 mg kg−1) which has previously proved highly toxic to woody plants [−1, while higher concentrations resulted in damage to young tree seedlings. This could explain why seedlings exposed to MS/BR with a DMA concentration of 8.06 mg kg−1 were able to grow.The high efficiency of metal phytoextraction by y plants ,45. The Paulownia over several hundreds of years [Paulownia hybrid to remediate substrate polluted with selected elements only. PEN values calculated previously for Cd in six Chinese cabbage cultivars were from 3745 to 53,433 [Paulownia from 5800 (plants growing under MS/BR system) to 455,000 plants (control in the first year of the study). On the other hand, PEN values for Pb and Zn were 351–3252 and 220–1279 shoots, respectively, while in the case of Piptatherum miliaceum (L.) Cosson they were 22,000 and 4300 shoots, respectively [Paulownia hybrid for many years.Due to the effect of the chemical composition of the substrates, it is difficult to clearly state to what extent the results obtained in this work rank the studied hybrid in a hierarchy based on the potential of this species for effective metal phytoextraction. Oxytree could be an effective and selective accumulator of NE, B, Hf, K, Mg, Mo, Na, P, Pb, Rb, Re, Sr, Ta, Te, W and Zn as confirmed by a BCF > 1. Moreover, TF > 1 calculated for Ba, Be, Bi, Cd, Cs, Cu, Hf, Hg, In, K, Mn, Mo, P, Rb, Re, Se, Sn, Sr, Ta, Te, Th, Tl, W and Zn directly demonstrates the significant potential of this hybrid for the remediation of highly contaminated wastes. Unfortunately, calculated MER values showed that extraction of the studied elements was limited. All values of MER were lower than 1%, which is typical for the majority of plants and suggests that treatment of the waste used in the experiment will require the growth of of years . On the ectively . It shouPaulownia [Paulownia lines of different leaf sizes, showing varying efficiency in Pb and Zn phytoextraction. This suggests that the accumulation of metals may be closely related to the size of plants. Any change in soil pH strongly affects metal solubility and its bioavailability for plants [Paulownia compared to the control, especially for the FT and FT/BR substrates, as well as the significant reduction of biomass. Under normal conditions, Ca is a dominant component among base cation in the soil sorption complex and plays an extremely important role, both in maintaining soil fertility and proper plant functioning. In our study Ca2+ concentration in the sorption complex of FT and MS substrates was over 70 and 55 fold higher respectively, compared to the control. Despite the positive role played by this cation, in such extremely high concentrations, it can disturb the proper management of other plant nutrients present in the soil solution, such as K+ and Mg2+ [−1 respectively, which was much higher in comparison with the other experimental substrates. In such conditions, plants have a difficult uptake of water from the substrate, and as a result of osmotic stress, their growth slows down [The limited uptake of selected elements may be the effect of the high pH of the applied substrates, which may be the next factor able to increase MER values. However, limited translocation and metal accumulation in roots have previously been described for aulownia . The autr plants . In alkaand Mg2+ . An impoows down . This isPaulownia, like other plants, has a characteristic physiological response [Paulownia plants were indirectly measured by assessing pigment content in leaves [response ,50,51. Tn leaves . Howevern leaves .Paulownia elongata S. × Paulownia fortunei. The obtained results clearly indicated that TPC and the biosynthesis of individual metabolites were inhibited, as proved by the decreased total antioxidant activity values. In addition, hydroxybenzoic acid biosynthesis was more susceptible to inhibition than hydroxybenzoic acids, especially in leaves. In defense mechanisms under metal stress, phenolic compounds play the role of electron donors in the ROS scavenging system. However, even phenolic acids with high antioxidant potentials such as caffeic, chlorogenic and ferulic were not accumulated in Paulownia leaves and roots. The oxidative mechanisms resulting from metal stress are represented by both cinnamic and benzoic phenolic acids by either chelating heavy metals or removing free radicals [Paulownia cultivated in waste materials. Considering the phenolic profile, breaks of the metabolic pathway occurred at different stages depending on the waste material used, which is a start point for future studies.Phenolic compounds are secondary metabolites, playing numerous functions in plant metabolism, including defense mechanisms against various stressors. They are recognized as biomarkers of plant response in conditions of elevated metal concentration in soil/substrate ,55, and radicals . HoweverPlant stressors also activate other intercellular defense mechanisms in which low-molecular-weight organic acids are involved. Their role is to maintain the homeostasis of elements in cells , but thePaulownia roots was similar for the control and plants cultivated in FT, which was characterized by a high content of K, Ca and Mg. However, a significant decrease of oxalic and acetic acids content was observed, with a simultaneous increase in malic and citric acids. For biochar supplemented FT, the sum of detected acids was more than two-fold higher, with preservation of the tendency mentioned above. The observed changes may be related to the substrate characteristics, where the soluble cations, predominantly Ca and Mg, may have been exchanged with non-exchangeable and buffered soluble K as well as by organic acids produced by plant roots into the rhizosphere [Paulownia roots could also be related to the application of highly porous materials, such as biochar, which caused a significant loosening of substrate structure and improvement of air-water properties, thus directly affecting the defense mechanisms [Paulownia plants, the accumulation of LMWOAs in roots decreased, while the addition of BR to MS again stimulated their synthesis. The significant decrease in acid content may be related to the elemental overload in the substrate, especially of Cu, Cd, Zn and Pb, with a concomitant decrease of plant biomass. However, it is indisputable that increasing soil loosening with BR again stimulated acid synthesis.In the present study, the sum of detected LMWOAs in zosphere . Moreovezosphere ,65. Manyzosphere . Increaschanisms . In the Paulownia, citing the Opinion of the Committee for Plants of the State Council for Nature Conservation [The expansion of invasive  species is a significant ecological problem for a number of reasons, including the mixing of species ranges and ultimately the homogenization of the environment. According to the Bern Convention on the Conservation of European Wildlife and Natural Habitats, it is necessary to protect species and habitats through legislative and administrative measures . For thiervation , for remPaulownia prefers higher temperatures and significant water requirements. Therefore the first should be a proper selection of clones [f clones . Clones f clones . The self clones ,72.Paulownia showed a varying ability to uptake and translocate individual metals, depending on the substrate on which it grew. The reduction of biomass compared to the control plants was an obvious consequence of the presence of waste in the substrate. On the other hand, the addition of biochar to highly polluted mining sludge suggests its important role in increasing the adaptation of this plant to unfavorable growth conditions. The obtained results suggest that growth on wastes with moderate concentrations of metals could limit the physiological response of Paulownia and thus facilitate its growth in subsequent years of the phytoextraction process.Paulownia plants cultivated in heavily polluted waste materials does not illustrate their protective role in defense and adaptation mechanisms and this phenomenon requires further research.The present studies clearly demonstrated that LMWOAs biosynthesis in plant roots plays an important role in adaptation, tolerance and detoxification mechanisms under conditions of excessive concentrations of toxic elements. Therefore, acid profiling may be a key tool to elucidate the nature of plant acclimation and may ultimately aid the development of new plant varieties that are tolerant to environmental changes. Thus, plant metabolomics should be widely employed to evaluate stress biology by identifying different compounds produced in response to environmental stressors and the role these compounds play in acclimation or tolerance responses. Phenolic compounds play an important role in response to metal stress in plants, which occurs as an increase in their overall content or enhanced biosynthesis of particular metabolites. However, the observed depletion in phenolic biosynthesis in


Further, the most frequently provided treatment methods were adrenocorticosteroids, antibiotics, and conservative treatment. The low recognition rate of SFTS in Japan might lead to a misdiagnosis or delay in diagnosis and treatment, especially in mild to moderate cases. Medical professionals and citizens who live in areas inhabited by ticks need to be informed about SFTS to appropriately diagnose and manage SFTS cases in Japan in the future.Severe fever with thrombocytopenia syndrome (SFTS) is an infection mediated by ticks and has been reported to have a high mortality rate in Japan. At our hospital, we reported three cases of SFTS with relatively positive outcomes. We reviewed reports of SFTS cases in Japan to clarify the current state of the disease in Japan, the treatment provided, and its outcome. The Ichushi Web was searched for literature using the following terms as keywords: “SFTS” or “severe fever with thrombocytopenia syndrome”. Overall, 174 cases were collected and reviewed. The mean age of patients was 70.69 years old, and the mortality rate was 35%. The dead group was significantly older ( Severe fever with thrombocytopenia syndrome (SFTS) is a viral infection transmitted by tick bites. It is often prevalent during spring to summer and is characterized by fever, thrombocytopenia, hemorrhage, and gastrointestinal symptoms. SFTS was first identified in China in 2009 and was first reported in 2011 in humans ,4. The cThere are large gaps in the literature regarding differences in mortality rates between countries. For example, the reported mortality rates of those diagnosed with SFTS were 4.8%, 21.8%, and 27% in China, South Korea, and Japan, respectively ,6,7,8. IDiverse studies have been conducted to identify the factors associated with the severity of SFTS. For example, in a prospective study involving 2096 patients with SFTS who were treated in hospitals located in Henan Province, China, from April 2011 to October 2017, the mean age at the time of hospital admission was 61.4 years, 59% of those affected were female, and the mortality rate was 16.2% . TherefoThe severity and mortality rates of SFTS differ considerably for each country. Specifically, the mortality rate in Japan has been shown to be approximately 30%, indicating a poor prognosis ,9. In coThus, we aimed to investigate the treatments most often provided and the clinical outcomes among patients diagnosed with SFTS in Japan, focusing on academic reports published in Japanese. We also aimed to highlight the treatment and outcomes of three specific SFTS cases from rural areas.Of the patients hospitalized at Unnan City Hospital between January 2013 and July 2021, the cases of three patients diagnosed with SFTS were described with regard to symptom onset, diagnosis, and treatment. We have obtained informed consent from each patient.http://www.jamas.or.jp/service/ichu/about.html: Access date, 1 August 2021) for literature published between January 2013 and July 2021, using the following terms as keywords: “SFTS” or “severe fever with thrombocytopenia syndrome”. Ichushi Web is an online Japanese literature search system provided by the Non-Profit Japan Medical Abstracts Society. The Ichushi Web database covers about 10 million medical papers from 6000 journals in Japan and is often used to search for Japanese literature. As the inclusion criteria for the literature, we included case reports and studies that targeted humans and were original articles or abstracts presented for academic conferences held in Japan. We excluded studies that were not academic reports, those that targeted other organisms, and papers without original data. The following data were collected from each case report: reported year, region, patient information , AST level (U/L), platelet count (×104/μL), hemoglobin level (g/dL), white blood cell count (/μL), neutrophil count, and whether they developed hemorrhage or had neurologic or gastrointestinal symptoms and cytopenia).We searched the Ichushi Web  was clearly noted. Cases with neurologic symptoms were defined as those in which patients had an indication of staggering or disturbance of consciousness; cases that resulted in death were also included. Gastrointestinal symptoms included nausea, vomiting, diarrhea, and loss of appetite. We defined cases that had a decrease in the counts of at least one blood cell type, including red blood cells, white blood cells, and platelets, as having “cytopenia”. To ensure that the study quality was reliable, we collected and analyzed the data based on the PRISMA standards. This systematic review was registered in PROSPERO (registration number: 287115) and conducted according to the standard procedure.4/μL), hemoglobin level (g/dL), white blood cell count (/μL), neutrophil count, and whether the patient developed hemorrhage or had neurological or gastrointestinal symptoms and cytopenia. Student’s t-tests and Mann–Whitney U tests were performed for comparisons of parametric and non-parametric data, respectively. Statistical significance was defined by a p-value < 0.05. All statistical analyses were performed using EZR , a graphical user interface for the R software environment .The cases were categorized into two groups—either dead or alive—to investigate and compare the patients’ demographic and clinical information, including age, sex, chief complaint, duration from symptom onset to hospital admission, type of treatment provided, LDH level (U/L), AST level (U/L), platelet count , elevation of liver and muscle enzymes , and dehydration , which resulted in her being admitted to the hospital on the same day for investigation of the cause of fever. Cytopenia further progressed after hospital admission, and abnormally high levels of ferritin  were observed on Day X + 2; therefore, a bone marrow examination was conducted. As a result, she was diagnosed with hemophagocytic syndrome and treated with adrenocorticosteroids. The patient was finally diagnosed with SFTS using polymerase chain reaction (PCR) testing. She underwent fasting because of disturbance of consciousness, probably due to encephalopathy, and nutrition was managed with a central venous catheter. The platelet count was the lowest at 1.7 × 104/μL on Day X + 5; thereafter, its value and other laboratory data improved after treatment with fluid and platelet transfusions. Although rehabilitation took a long time, the patient was discharged after 1.5 months of hospitalization.The patient had no notable medical history, and health checkups conducted every year had shown no abnormalities. On Day X − 4, she was referred to a dermatologist for eczema on the right side of her neck and was prescribed antibiotics; on the same day, she developed chills and fever symptoms. A high fever of approximately 39 °C persisted for a few days, which caused her to visit our hospital on Day X. Vital signs upon arrival at the hospital were as follows: body temperature, 38.7 °C; blood pressure, 135/72 mmHg; heart rate, 62 beats/min; SpO2, 96%; and respiration rate, 20 breaths/min. Blood tests revealed that she had cytopenia of three cell types  and a prolonged activated partial thromboplastin time (57.7 s), and was admitted to the hospital for investigation of the cause of fever. Thereafter, abnormally high levels of ferritin (9824.7 ng/mL on Day X + 3) and elevation of AST (maximum at 199 IU/L on Day X + 7) were observed. Bone marrow examination and PCR testing were conducted, and she was diagnosed with hemophagocytic syndrome and SFTS. The platelet count was the lowest at 4.1 × 104/μL on Day X + 5, although it improved thereafter. Treatment with fluid transfusion, enteral nutrition, and adrenocorticosteroids was provided, which improved the symptoms associated with SFTS. However, she repeatedly developed sepsis due to a new bacterial infection (pneumonia and pyelonephritis) and needed to be treated with antibiotics, which required a long period of hospitalization. Finally, the patient was discharged to a long-term care facility after 5 months of hospitalization.The patient had a medical history of atrial fibrillation, hypertension, and hypothyroidism, but led a normal life until Day X − 1. She consulted a nearby doctor because she acutely developed staggering and gait disturbance on the morning of Day X and was referred to our hospital for close examination and treatment. Vital signs upon hospital arrival were as follows: body temperature, 39.7 °C; blood pressure, 138/67 mmHg; heart rate, 87 beats/min; SpO2, 94%; and respiration rate, 18 breaths/min. The blood test showed cytopenia of two cell types  and elevation of a liver enzyme (AST 75 IU/L); however, the C-reactive protein value was just slightly elevated. Due to several small blood spots on the left palm of the patient and episodes of tick bites, SFTS was considered as the cause and was confirmed by PCR testing. After hospital admission, dehydration and prerenal acute kidney injury were observed due to the inability to consume oral fluids, so fluid transfusion was provided to treat the dehydration. The platelet count continued to decrease and was the lowest at 6 × 104/μL on Day X + 5, although it improved thereafter. The level of the liver enzyme AST also peaked and improved after reaching its maximum value of 143 IU/L on Day X + 3. She was able to consume food orally, and no other complications developed. She was discharged on Day X + 14.The patient had a history of paroxysmal supraventricular tachycardia, dyslipidemia, and glaucoma. She had butchered wild boars that were exterminated daily. In the afternoon on Day X − 3, she developed fever and nausea. The cause of the fever was unknown, and she visited our hospital on Day X − 1. Vital signs at the time of arrival to the hospital on Day X were as follows: body temperature, 38.2 °C; blood pressure, 113/84 mmHg; heart rate, 154 beats/min; SpOWe searched the Ichushi Web on 1 August 2021, to extract 160 articles. From these articles, 136 studies targeting humans were extracted. We excluded those without full-text literature and those describing the same case, and the final number of available literature articles was 129. The number of cases included in the available literature was 171. By adding the three cases described in this review series, the total number of cases was 174 .p < 0.001). The duration from symptom onset to hospital admission was significantly shorter in the dead group than in the alive group. In addition, the dead group developed hemorrhage and neurological symptoms significantly more frequently. In contrast, the alive group developed cytopenia significantly more frequently. No significant differences were observed in the other factors between the alive and dead groups . The mortality rate was 35.1%. In terms of age, the dead group was significantly older than the alive group , malaise (30.5%), diarrhea (22.4%), appetite loss (20.1%), nausea or vomiting (13.2%), pain, including muscle, joint, and lower back pain (10.9%), disturbance of consciousness (9.2%), difficulty in moving/walking (6.3%), abdominal pain (6.3%), staggering or weakness (5.7%), chills (5.7%), headaches (5.7%), lymphadenopathy (4.0%), skin rash (3.4%), and gastrointestinal symptoms (not specified) (1.7%).p = 0.025), and skin rash was observed significantly more often in the dead group (p = 0.021). There were no significant differences between the alive and dead groups for the other symptoms , antibiotics (39.1%), conservative treatment, including fluid transfusion (18.4%), dialysis or plasma exchange (13.8%), DIC therapy (10.3%), blood transfusion (10.3%), antiviral drugs (7.5%), immunoglobulins (6.9%), respiratory management, including endotracheal intubation (6.3%), antifungal drugs (6.3%), granulocyte colony stimulating factor (G-CSF) (2.9%), immunosuppressive agents (2.3%), and no treatment or follow-up observation (1.7%).p = 0.04, 0.035, respectively). On the other hand, the number of immunoglobulins, and immunosuppressive agents used to treat SFTS cases were significantly higer in the dead group . There was no significant difference between the alive and dead groups for the other treatments  ,9. We foHaemaphysalis longicornis as well as Amblyomma testudinarium, Haemaphysalis flava, Haemaphysalis formosensis, Haemaphysalis hystricis, Haemaphysalis kitaokai, Haemaphysalis longicornis, and Haemaphysalis megaspinosa can transmit the SFTS virus to humans [This research revealed that SFTS cases were mainly observed in the West Japan area. Therefore, one should pay attention to the spread of this disease in the future. According to a survey conducted by the Japan National Institute of Infectious Diseases in 2014, ticks carrying the SFTS virus were identified not only in regions where patients were diagnosed with SFTS  but also in regions where there were no confirmed SFTS cases , suggesting that the virus-carrying ticks are widespread across Japan ,8,10,11.o humans ,8,10,11.The SFTS virus is transmitted by the ticks through a life cycle involving wild animals, including deer, wild boar, cats, and dogs ,13. A suA survey by the Ministry of the Environment reported that the habitat area of Japanese deer and wild boars was mainly West Japan, although the area had been spreading northward every year ,18,19,20This research showed a higher mortality rate (approximately 30%) for SFTS cases reported in Japan than for those reported in China and South Korea ,6. AccorThose who developed severe conditions acutely might have received a quick response from clinicians, but cases with mild to moderate symptoms may not have been fully diagnosed. Undiagnosed disease may also be associated with the fact that patients do not complain about the symptoms because of a lack of awareness of the possibility of SFTS . In termThe use of antiviral drugs can be considered in critical cases of SFTS. In this study, the numbers of patients received concervative treatment including fluid transfusion, and administered antiviral drugs were significantly higher in the group that was still alive. Previous studies have reported that there was limited evidence supporting active treatment, whereas conservative treatment administered appropriately was the most critical course of action ,17. TherConsistent with the results of the overall systematic review, the three cases treated at our hospital primarily had nonspecific symptoms, such as fever, gastrointestinal symptoms, and malaise. Of those, two cases reported no evident episodes of a tick bite, although they were diagnosed with SFTS based on laboratory test abnormalities, including cytopenia, during hospitalization. It took several days to decide to perform the PCR test for a definitive diagnosis. Many patients with SFTS have relatively mild symptoms ,28. If tThis study had some limitations. First, this study only included Japanese literature; thus, racial differences in the findings must be considered. This study focused on the present conditions for the management of SFTS in Japan, and it investigated differences in the prevalence and management of SFTS in an Asian context. Second, most of the investigation targets were case reports; thus, all cases in Japan may not have been identified. In this research, we focused on Japanese SFTS cases by comprehensively utilizing the most famous Japanese search engines to avoid overlooking rare presentations from local conferences and journals in Japan. Future studies should investigate the effectiveness of interventions based on information about the number of confirmed SFTS cases in communities and changes in mortality rates among those affected. These factors would lead to a more realistic understanding of SFTS infections and associated clinical outcomes.This study clarified the present conditions of the clinical presentation and mortality of SFTS in Japan through a systematic review of Japanese case reports. The present conditions for the management of SFTS can be negatively impacted by the low cognizance of SFTS, which can lead to misdiagnosis and delayed treatment. In addition, the mortality rate may be high because of overlooked SFTS cases with mild symptoms. In Japan, information regarding SFTS should be disseminated not only among health care professionals, but also among citizens living in places with ticks to ensure the effective diagnosis and management of SFTS in Japan.


This study aimed to investigate the immediate and short-term impact of the pandemic on the psychological well-being of Italian children and adolescents with psychiatric disorders and their families. Overall, 56 patients aged 6–18  and their parents were evaluated during the COVID-19 lockdown (T0) and after 4 months (T1). An ad hoc data sheet, Youth Self-Report 11–18 (YSR), Child Behavior Checklist 6–18 (CBCL), and Depression Anxiety Stress Scale-21 (DASS-21) were administered. Patients, mainly suffering from internalizing disorders, overall demonstrated a good adaptation to the pandemic context. Moreover, patients with behavioral disorders showed a greater psychological discomfort at both T0 and T1 compared to patients with internalizing disorders. Over time, patients presented an improvement on the emotional side, as proven by a significant decrease in internalizing and post-traumatic stress problems. Finally, no significant differences were found in the emotional-behavioral profile of patients according to the means of conducting neuropsychiatric interventions during the lockdown , thus allowing us to exclude important negative effects caused by the transition to remote therapy. Concerning parents, an inverse relationship emerged between the DASS-21 scores and the level of resilience, which therefore represents a protective factor against psychological maladjustment. Over time, an improvement in the psychological well-being of parents was observed, as shown by a significant decrease in mothers’ anxiety and fathers’ stress. After an outbreak of pneumonia of unknown etiology in the city of Wuhan in China, the World Health Organization (WHO) declared the epidemic of the novel coronavirus SARS CoV-2 COVID-19) a public health emergency of international concern on 30 January 2020. The following day, in Italy, the Council of Ministers ordered several measures to deal with the emergency nationwide. Then, on 24 February 2020, more severe measures were applied, such as school closures and quarantine for all Italian citizens. On 11 March 2020, the coronavirus disease (COVID-19) was declared a global pandemic by the WHO ).In the preliminary analyses, descriptive statistics and frequencies tables were calculated to delineate the socio-demographic and clinical characteristics of both patients and their parents. At T1, the clinical features of the sample  were described in more detail.Before performing the subsequent analyses, we checked whether the clinical subgroups of patients (at both T0 and T1), the means of conducting neuropsychiatric interventions during the lockdown, and the scores on the considered scales of YSR and CBCL (at both T0 and T1) significantly differed for age and gender. Since no significant differences emerged, and the literature strongly discourages the inclusion of several variables in the model when sample size is limited and group size is unequal   affected the psycho-behavioral profile of patients, the Kruskal–Wallis test  was condThen, the Mann–Whitney U test  was applConcerning the relationship between parents’ resilience and their level of stress, anxiety, and depression, Spearman’s rho (ρ) correlations between the DASS-21 scales and questions about resilience were conducted, considering both T0 and T1. Spearman’s rho coefficients have been directly interpreted as a measure of effect size, according to Cohen’s  criteriaFinally, to check if there was a significant change over time (T0 to T1) in the emotional-behavioral aspects of patients, the paired sample Wilcoxon rank test  was applp < 0.05.Statistical significance was set at 38 patients (67.9%) suffering from “emotional-affective disorders”, corresponding to clinical situations of mood disorders  and neurotic disorders, related to stress and somatoforms disorders .7 patients (12.5%) with “behavior and personality disorders”, with ICD-10 codes F60–69 and F90–98; personality disorders, attention deficit hyperactivity disorder (ADHD), conduct disorder (DC), and oppositional defiant disorder (PDO) are detected.11 patients (19.6%) with neurodevelopment disorders and psychosis, with ICD-10 codes F80–89 and F20–29, such as autism spectrum disorders and psychotic syndromes.With regard to the diagnostic classification of mental illness and behavior by nosographic criterion according to the ICD-10 , the samPertaining to the clinical division between presence and absence of behavioral expression, the sample consisted of 18 children (32% of the sample) with significant behavioral expression  and 38 children (68% of the sample) with poor behavioral expression . More specifically, the patients with predominantly behavioral problems were 8 boys (44.5%) and 10 girls (55.5%), with a mean age of 12.7 years (SD = 2.91); in this group, 15 patients (83.3%) were between 11 and 18 years old, and were thus the appropriate age to fill out the YSR. The patients in the internalizing category were 10 boys (26.3%) and 28 girls (73.7%), with a mean age of 13.7 years (SD = 2.68); in this group, 32 patients (84.2%) were between 11 and 18 years old, so they could complete the YSR.As for the other clinical variables evaluated, 14 children (25%) with neuropsychiatric disorders experienced a previous traumatic event, defined as stress of considerable importance in the child’s life: this is represented in 42.9% of cases by a conflicting separation of parents, in 28.8% of cases by an inability to adapt to a new environmental context, in 21.4% of cases by loss or serious pathologies in the family context, and in 7.1% of cases (1 child only) by frequent episodes of prolonged hospitalization.During home quarantine, 25% of families reported the exacerbation of some behavioral problems, such as more frequent and intense episodes of non-collaboration, indifference, physical/verbal aggression, poorly targeted/organized play, screaming/crying, social isolation, provocative attitudes towards others, attempts to escape, and self-cutting ideation.Regarding daily routines and biological functions during the lockdown, 44.6% of patients did not report changes in general habits. Moreover, only 12.5% of patients reported changes in the use of electronic devices, 21.4% described an alteration in sleep-wake rhythm, 12% experienced a change in nutrition, and 10.7% had increased in weight. Therefore, the vast majority of patients did not experience changes in daily routines and biological functions.With regard to stress-related symptoms, 53.6% of patients reported 0 symptoms of stress, 23.2% 1 to 5 symptoms of stress, 17.9% 6 to 10 stress symptoms, and 5.4% more than 10 stress symptoms. As can be noticed, the presence of stress-related symptomatology was not detected in more than half of patients.Concerning drug treatment, 25 children had ongoing psychopharmacological treatment at the end of February , and this increased to 27  as of March.Pertaining to neuropsychiatric interventions, between the pre-lockdown phase (February 2020) and lockdown (from March 2020), among the 48 patients  with an active neuropsychiatric intervention at the end of February, 44 patients maintained the intervention (79%), 5 of which were face-to-face and 39 remotely.Regarding psychological therapy, among the 31 children treated with psychotherapy in February 2020 , only 3 patients (9.7%) completely suspended this intervention during the lockdown.Then, among the 10 children  who received educational-rehabilitation treatment at the end of February, no changes in this type of intervention were observed during the lockdown.Finally, among patients and their parents, there was only one positive element to the virus: no hospitalization was experienced and only one case of quarantine took place in relatives. N = 41) and CBCL (N = 55) scale scores at T0.The socio-demographic characteristics of parents (56 mothers and 56 fathers), referring to the lockdown period, are shown in With regard to stress-related symptomatology, 61% of mothers and 75% of fathers reported the absence of stress-related symptoms, 30% of mothers and 23% of fathers reported 1 to 5 symptoms, 5% of mothers and 2% of fathers reported 6 to 10 symptoms, and 4% of mothers reported a total number of stress symptoms greater than 10.Concerning resilience, in question 1 related to commitment, 79.6% of mothers and 85.7% of fathers got a high score; in question 2 about control, 67.4% of mothers and 85.7% of fathers obtained a high score; and in question 3 about challenge, 67.4% of mothers and 77.6% of fathers reported a high score.The Kruskal–Wallis test, carried out to verify the effect of changes in neuropsychiatric interventions  on patients’ psycho-behavioral profiles evaluated through YSR and CBCL, showed no significant results.p = 0.004), while for paternal CBCLs, it had a significant effect on the total problem scale  and PTSP scale . To be more specific, higher scores were reported for patients with behavioral problems  compared to patients without such problems .On the other hand, statistically significant results emerged from comparing the CBCL scores  according to the clinical categories  by means of the Mann–Whitney test. Specifically, for maternal CBCLs, the clinical category was found to have a significant effect only on the total problem scale  and the paternal stress scale (p = 0.06). As for question 2 (“control”), low and non-significant correlations emerged only with the maternal DASS-21 stress scale (p = 0.14) and the paternal anxiety scale (p = 0.099), while the other correlations were all significant and moderate in magnitude. Finally, as regards question 3 , correlations were all significant; in particular, high correlations emerged with both maternal and paternal DASS-21 stress scales, while the other correlations were medium in magnitude. Overall, these results support an inverse relationship between resilience and psychological maladjustment.To investigate the relationship between parents’ well-being and their resilience, Spearman’s ρ correlations were carried out . As can Overall, 39 children and adolescents (and their parents) took part in the retest phase: 25 girls (64.1%) and 14 boys (35.9%), with an average age of 13.3 years (SD = 2.84). With regard to diagnostic categories , 25 (64.1%) patients were affected by internalizing disorders and 14 (35.9%) by behavioral disorders. Particularly, the patients suffering from behavioral problems were 7 (50%) boys and 7 (50%) girls, with a mean age of 12.4 years (SD = 3.16); in this group, 11 (78.6%) patients were between 11 and 18 years old, so they could complete the YSR. The internalizing problems category was composed of 18 (72%) girls and 7 (28%) boys, with a mean age of 13.8 years (SD = 2.70); in this group, 22 (88%) patients were of the right age to fill out the YSR (11–18 years).As for their therapeutic regimen at T1, 26.47% of patients had a psychiatric treatment ongoing, 32.4% a drug therapy, 38.2% a psychological therapy, and 14.7% an educational-rehabilitative therapy.Pertaining to the number of stress-related symptoms of children and adolescents, 44.4% reported 0 symptoms, 32.4% between 1 and 5, 14.7% between 6 and 10, and 8.8% more than 10 symptoms.N = 31) and CBCL (N = 39) scales at T1, these are presented in As regards the scores obtained on the YSR . In particular, higher scores were reported for patients with behavioral disorders  compared to patients with internalizing problems . Therefore, as already pointed out at T0, a greater perception of psychopathology in association to behavioral expression remains at T1, too. Moreover, as found at T0, no differences on the basis of the two clinical categories emerged considering the YSR scales.Differences in the YSR and CBCL scores at T1 according to clinical categories  were evaluated by means of the Mann–Whitney test. A statistically significant difference between the two clinical categories emerged only in the paternal CBCL total problems scale . For this reason, in interpreting results, we only considered the magnitude of a correlation, rather than its statistical significance, as suggested by the literature , the, the62])e . Thep = 0.042; MT0 = 66.9, SE = 1.67; MT1 = 64.2, SE = 1.67). There was also a reduction in T0 to T1 scores on the scale of post-traumatic stress problems (PTSP) in both mothers’  and fathers’ CBCL . On the other hand, there were no statistically significant changes in YSR scores from T0 to T1.Pertaining to change over time in the psycho-behavioral state of patients, the scores on the YSR and CBCL total problems, internalizing problems, externalizing problems, and PTSP scales in the second phase (T1) were compared, through the paired sample Wilcoxon rank test, with the scores obtained on the same scales as in the previous quarter (T0). The comparison showed a statistically significant reduction in scores on the maternal CBCL internalizing problems scale  and the paternal DASS-21 stress scale .With regard to changes over time in the psychological well-being of parents, the paired sample Wilcoxon rank test showed a statistically significant decrease in scores on the maternal DASS-21 anxiety scale  and short-term (T1) impact of the COVID-19 pandemic and quarantine on the psycho-behavioral profile of young psychiatric patients and their parents.With regard to the psychological well-being of children and adolescents with mental health disorders, no major changes were observed during the lockdown compared to the previous period. In fact, although changes in general habits were detected in more than half of the sample (55.4%), a considerable proportion of patients did not report such changes, and the vast majority (80–90%) did not present variations in biological functions, body weight, or daily exposure to screen-based media. Moreover, most patients did not report any symptoms of stress at both T0 and T1. Taken together, these results suggest a good ability of patients to adapt to a new and difficult context. Particularly, it could be hypothesized that subjects with psychiatric disorders present a kind of resistance—or maybe “habit”—to disadvantaged mental and environmental conditions, which prepares them to face difficulties. In addition, as stated by Conti et al. —who founNevertheless, this finding and its interpretation may be somewhat limited by the lack of a control group composed of children and adolescents from the general population. Consequently, to provide a full picture of this important topic, further research comparing children with and without psychiatric disorders should be undertaken. Furthermore, in the interpretation of results, it is also necessary to consider the characteristics of the sample, mainly composed of patients with disorders in the emotional-affective sphere, thus characterized by aspects that the lockdown has supported and normalized, such as social and performance anxiety, tendency to withdrawal, and avoidance.During the lockdown, a massive shift to telepsychiatry  has beenNo statistically significant differences were found in the emotional-behavioral profile of our patients according to the type of ongoing neuropsychiatric treatment . These data at least allow us to exclude important negative effects caused by the transition to remote therapy and appear to be in agreement with the arguments in favor of the use of telepsychiatry as a valid and effective methodology ,65. NevePertaining to the differences between patients belonging to the diagnostic category “internalizing” and those belonging to the diagnostic category “behavioral”, what has been observed, especially in clinical practice during the lockdown, is that children/adolescents with neurodevelopmental disorders and/or with externalizing disorders have been those most affected by the adopted restrictive measures. This clinical observation was then confirmed by higher scores in the CBCL total problems scale—which can be considered a general indicator of psycho-behavioral discomfort—in reports provided by both mothers and fathers of patients with behavioral problems. Moreover, a greater malaise for these patients was confirmed at T1, too. In fact, the CBCLs compiled by fathers report a greater presence of total problems for patients with behavioral problems compared to patients with internalizing problems. These results support the initial hypothesis that confinement within the home, and loss of rhythms, commitments, and planned therapeutic interventions may have represented significant obstacles for children/adolescents with externalizing problems . In factTherefore, our results substantiate previous findings in the literature, according to which patients with externalizing disorders, such as attention deficit hyperactivity disorder and autism spectrum disorder, are the most vulnerable to the effects of prolonged isolation and quarantine ,41. For Nevertheless, contrasting results emerged from another Italian work, conducted with pre-school children . This stAnother noteworthy aspect concerns the differences between mothers and fathers in the scores on the CBCL. In fact, mothers reported higher CBCL scores on all the scales considered at both T0 and T1 compared to fathers. Discrepancies between the CBCL scores of mothers and fathers have been already described in the literature, with higher scores reported by the former e.g., ,69,70). ,70. 69,7With regard to change over time in the psycho-behavioral state of patients compared to the lockdown period, they presented in the following months an improvement on the emotional side, proven by a significant reduction in scores at the CBCL scales regarding post-traumatic stress problems and internalizing problems. This result confirms our initial hypothesis of an improvement in the symptomatology due to the easing of the COVID-19 containment measures during the least critical phase of the pandemic in Italy. Nonetheless, this finding should be carefully interpreted; in fact, all patients had ongoing treatment, which, therefore, may have contributed to improving their psychological well-being.Another purpose of this work was to evaluate the psychological well-being of caregivers of children/adolescents with psychopathology during the different phases of the pandemic, also monitoring its change over time. The closure of schools, the strong limitations of social interactions, and the increasing of time spent together, also due to parents’ remote working, brought the family structure to a greater importance  for the Generally speaking, the vast majority of both mothers and fathers presented high levels of resilience and did not report stress symptoms at both T0 and T1. As observed for patients, it may also be that their parents present a kind of resistance to stress and/or challenge, which makes them prepared to cope with negative events. However, as previously stated for patients, future investigations involving a control group are needed in order to provide further support to this result.Then, an inverse relationship emerged between the level of anxiety, depression, and stress experienced by parents, and their resilience. This result is consistent with the literature  and furtOver time, parents showed a significant decrease in the DASS-21 scale scores; more specifically, mothers presented a decrease in anxiety, and fathers in stress symptomatology. Therefore, as hypothesized, the relaxation of the measures to contain the infection led to an improvement in the psychological well-being of both mothers and fathers.Despite the interesting findings that emerged from this work, some limitations need to be addressed. First, the small sample size, the prevalence of girls, and the inclusion of patients from a single neuropsychiatric unit in Italy did not allow for generalizing the observed results. Moreover, caution must be applied in interpreting results since the sample was mainly composed of patients with internalizing disorders. Another source for possible error which should be considered is the lack of a baseline measurement and so the retrospective collection of information about pre-emergency behaviors. An additional limitation of this study is the administration of self-report tools, which may be affected by several factors, such as social desirability, individual bias, or failure to understand questions. Finally, despite our preliminary analyses not highlighting significative differences for age and gender in the diagnostic categories, type of neuropsychiatric interventions during the lockdown, and psycho-behavioral profile defined through YSR/CBCL, further works with a larger sample size need to be carried out to clarify the role of such variables in influencing the adaptation and the psychological well-being of young patients during health emergencies.In summary, this study explored the psychological well-being of a group of young Italian patients and their parents, in relation to the considerable and sudden changes caused by the COVID-19 pandemic and the related measures to contain the risk of infection.The group of patients, mainly suffering from internalizing disorders, overall showed a good adaptation to the pandemic context. To confirm this, a greater psychological discomfort was detected in patients with behavioral problems, attributable to neurodevelopmental and conduct disorders, compared to patients with internalizing disorders at both T0 and T1.Although our data are preliminary and require further investigations, they could have an impact on the reorganization of neuropsychiatric services required by the health emergency: the temporary suspension of usual and non-urgent clinical-care activities in person and the transition to telepsychiatry may be more suitable for certain psychopathologies, such as those characterized by internalizing symptoms , while other conditions more impacting on a behavioral level should maintain specialist interventions in person, also guaranteeing more resources in terms of space and operators.With reference to what has been explained for patients characterized by disorders in the emotional-affective sphere, with an inherent avoidance component, it will be important to monitor their psychological well-being at the time of return at school, since that period could be particularly challenging for this group.As for the parental environment, both mothers and fathers showed a good adjustment to the difficult situation caused by the COVID-19 outbreak. Moreover, most parents presented high levels of resilience, which may have helped them to successfully face adverse circumstances. To support this, lower levels of stress, depression, and anxiety were assessed in parents with higher levels of resilience. Therefore, resilience was confirmed to be a significant protective factor against psychological maladjustment. This result could be particularly useful in implementing parenting support interventions, especially in periods characterized by uncertainty and burden, such as health emergencies. In fact, programs which foster resilience and promote the development of personal skills could represent a promising avenue to prevent the onset of parental stress and burn-out, thus also improving the psychological well-being of the whole family.


South Korean studies on coronavirus disease-2019 (COVID-19) treatment have described the use of community treatment centers (CTCs), which combine elements of the home and hospital, to isolate and treat mild COVID-19 patients. While the number of South Koreans diagnosed with COVID-19 cases has varied greatly by season, the number of confirmed cases in foreign nationals has shown no seasonality, with an average of around 25 to 30 per day. For foreign patients, accommodation arrangements and travel routes may be difficult; they may also have difficulty accessing medical care, so require careful management.We discuss our experience in operating and managing a CTC for foreign COVID-19 patients arriving in South Korea with mild symptoms. We also propose guidelines for efficient use of resources with respect to treating these patients in CTCs.We present the clinical findings of patients treated at the CTC between 7 October and 22 November 2020, and make some recommendations. We quarantined and treated foreign patients with mild symptoms of COVID-19 at the Ansan CTC. Discharge is determined based on clinical symptoms rather than polymerase chain reaction results. Medical and administrative staff use building A, while building B is used for isolating patients. Medical rounds are in the form of twice-daily video calls. Three kinds of foods with medication are served according to the patient's country of origin.In total, 315 patients were admitted to the Ansan CTC between 7 October and 22 November 2020; 145 of them were discharged from the CTC and 26 were transferred to other hospitals.To utilize medical resources efficiently during the pandemic, it is desirable to reserve CTCs exclusively for foreign patients. In Korea, 34,201 patients had been confirmed as COVID-19-positive by 30 November 2020, following the first case of a Chinese woman who arrived from Wuhan, China, on 19 January 2020. There have been 29,651 South Korean COVID-19 patients and 4,550 from overseas. Currently, critically ill COVID-19 patients are hospitalized and treated in designated hospitals, while those with mild or no symptoms are treated in isolation in community treatment centers (CTCs).,4 It is important to treat COVID-19 patients entering South Korea from other countries. Since 12 June 2020, all asymptomatic overseas patients have self-isolated and been tested for COVID-19 within 3 days of arrival in South Korea; those positive for COVID-19 have been divided into 2 groups: high-risk and mild/asymptomatic. The National Medical Center provides beds for high-risk patients. Mild and asymptomatic patients are mainly assigned to temporary patient facilities called CTCs, which combine elements of the home and hospital environment. Patients are isolated and monitored in the CTCs, which were designed by the Korean government. There have been several reports describing the principles and operation of CTCs in Korea.–7Coronavirus disease-2019 (COVID-19) spread around the world in 2020 after the initial outbreak in Wuhan, China in 2019. For foreign patients, accommodation arrangements and travel routes may be unknown; access to medical care may also be limited, so careful management is required.The international migrants who need to cross borders, even during the COVID-19 pandemic, are mainly students and workers. Around 1.5 million people are moving around the world. However, there have been no other reports on the management of mild and asymptomatic overseas patients. China built a new quarantine hospital for such patients, while other countries implemented self-quarantine measures without hospitalization.,11There were 769 COVID-19 patients on cruise ships in Japan in February 2020. The patients were classified according to severity and assigned to hospitals. Patients with mild or no symptoms were also treated in isolation at the hospital and categorized into the high-risk group.As discussed above, although the patient-management activities of CTCs have been reported, this has not extended to those entering South Korea from abroad. In addition, there have been no reports of non-face-to-face management of COVID-19 patients in CTCs. Thus, we present recommendations for managing mild and asymptomatic overseas COVID-19 patients.2 Existing accommodation facilities were used as CTCs beginning in March 2020. Chest X-ray and real-time polymerase chain reaction (RT-PCR) analyses were conducted, and telemedicine in the form of smartphone video calls was used to successfully minimize the spread of infection. However, the importance of managing overseas migrants has increased due to the increasing prevalence of COVID-19 in Europe, the United States, and other territories, including Asia. Overseas COVID-19 patients are classified based on symptoms (symptomatic or asymptomatic), nationality (Korean or non-Korean), stay duration (long- or short-term), and the requirement for quarantine. A diagnostic test is conducted for all non-Korean individuals arriving from overseas except flight attendants. Self-quarantine and active monitoring are performed for those who are negative for COVID-19. COVID-19-positive patients are classified as severe or mild and provided with a hospital bed.In February 2020, there was a major outbreak of COVID-19 in places of worship in Daegu, South Korea; in response, the first CTC was opened in South Korea to address the shortage of medical facilities.This study is retrospective observational study and was approved by the hospital institutional trial review board (IRB File No. 2020-12-030-001).2.1 The criteria for asymptomatic patients are as follows: alert, <50 years old, no underlying disease, nonsmoker, and body temperature <37.5°C without antipyretic drugs. The criteria for mild symptoms are as follows: alert, <50 years old, 1 or more underlying diseases, and body temperature <38°C with antipyretic drugs .The admission process is as follows. First, after being identified at a local health center, the patient is informed of the quarantine arrangements. Second, a “facility allocation request” is made after assessing disease severity. Patients are then classified and assigned to a facility. Third, the local health center transports the patient via public ambulance; the paramedics and drivers wear level D protective clothing during this process. Finally, patient care is transferred to the CTC; if the symptoms worsen, the patient is transferred to a designated hospital.Discharge is determined based on clinical symptoms rather than PCR results. Asymptomatic patients are discharged 10 days after diagnosis if no symptoms are observed during the hospitalization period. Patients with mild symptoms can be discharged if symptoms show improvement and there has been no fever for 72 hours at 10 days after symptom onset. The criteria for discharge are those of the KCDC based on the report that viral culture remaining negative at about 8 to 10 days after the onset of COVID-19 symptoms.2.2A training institute for small-to-medium-sized businesses in Ansan was converted into a CTC. Building A is used by medical and administrative staff, and building B is used for patient isolation and examination, including X-rays. Building B has a total of 4 floors; there are 42 rooms on the first floor and 54 on the second, third, and fourth floors, with a total of 204 rooms. There are 36 single rooms and 168 double rooms, all of which are occupied by a single patient. However, as an exception, infants and parents entering the CTC together are allowed to stay in the same room. The medical staff and patients are separated on the first floor by bulkheads and acrylic windows to minimize the time and effort required by medical staff to put on and take off personal protective equipment (PPE) , 1 day of nighttime duty (8 pm to 8 am), and 1 day off. Each regular nurse takes responsibility for up to 6 patients. One senior medical specialist and 4 public health doctors work in the Ansan CTC. In total, 12 emergency-medicine specialists from Soonchunhyang University Bucheon Hospital work shifts at the Ansan CTC. Four public health doctors are rotated every 2 weeks. In preparation for emergencies, the senior specialist delivers training to nurses and public health doctors in basic life support and the use of defibrillators. In addition, 1 radiographer performs chest X-rays in the CTC.In total, 13 nurses  work in the Ansan CTC. The head nurse and charge nurse perform regular daytime duties, while the 11 regular nurses have a schedule of 4 days of 1 day of daytime duty ). Patients are given a pulse oximeter, a tympanic membrane thermometer, and a sphygmomanometer, and instructions for their use are provided on the day of admission by a nurse wearing level D PPE. The drugs provided are mainly over-the-counter medications to treat symptoms .2.5pm; if the number of patients for a given day is high, a morning admission session is added. The patients’ clothes are discarded on admission. During admission, patients are instructed to open their luggage as infrequently as possible. On admission, a nurse instructs each patient in the use of personal medical equipment  and messenger applications , and asks them to fill out an epidemiological survey form. A public health doctor then obtains the medical history  are performed for all patients and those with special needs, respectively. A primary nurse checks the patient's self-recorded vital signs , mood, level of discomfort, etc. When vital signs are unstable or symptoms have worsened, the doctor in charge decides whether to transfer the patient to the hospital. Video calls are conducted using patients’ smartphones; Google Translate or a foreign language call center are used to overcome language barriers. Most patients have a smartphone, but a public phone is available in the CTC in the event of problems using messenger applications.Patients self-reported twice a day using specialized mobile application  on vital signs , chief complaints, and psychological conditions  Fig. .Two or 3 chest X-rays are performed weekly, depending on the patient volume. Chest X-ray is typically performed once immediately after hospitalization, with follow-up imaging conducted in cases with abnormal findings or worsening symptoms. The PCR test is not routinely performed, but is available for patients willing to pay for it.Patients select halal, vegetarian, or Korean meal options on admission. Military personnel wearing level D PPE serve meals 3 times a day. Medication is provided at meal times; if required at any other time, a nurse wearing level D PPE leaves the medication in front of the room.All waste (including food waste) from patients is disposed of as medical waste, that is, is sterilized, disinfected or incinerated. Disinfection of the public spaces  is performed 3 times per day. Disinfection of patient areas is performed after first ventilating the area, and takes place over the course of at least 1 hour for up to 24 hours after patient discharge. After cleaning, additional ventilation is performed for 6 to 24 hours before the arrival of new patients.Patients are divided into groups A–C; in group A, all costs associated with COVID-19 quarantine are covered, while in group B lodging expenses are covered, but living and medical expenses are not. Group C patients cover the entire cost of the CTC stay themselves ).3In total, 315 patients were admitted to the Ansan CTC between 7 October and 22 November 2020; 145 of them were discharged from the CTC and 26 were transferred to other hospitals. During this period, the number of total cases of confirmed patients gradually increased toward the end of November, but the number of foreign patients and the number of admissions at the Ansan CTC were similar  patients were admitted directly to the CTC from an airport or quarantine facility, while 52 (16.5%) were admitted from a local health center, and 127 (40.4%) were admitted from residential facilities. For 76 (24.1%) patients, the hospitalization route was unknown. Among the 315 patients, 145 (84.8%) were discharged and 26 (15.2%) were transferred to other hospitals. In total, 31 (18.5%) patients received medication, 11 were admitted with fever and myalgia, 12 were admitted with COVID-19 symptoms other than fever, 10 were admitted due to comorbidities , and 3 were admitted for dysmenorrhea , 4 with uncontrolled fever (15.4%), 4 with abnormal chest X-rays (15.4%), 3 with chest tightness (11.5%), and 3 others (11.5%) (Table In total, 8.3% of patients had symptoms for a median of 3 days before COVID-19 diagnosis, while 16.7% had symptoms at the time of diagnosis and 11.9% had symptoms for a median of 1 day after diagnosis; 63.1% of patients were asymptomatic (Fig. 4During the study period, among all overseas COVID-19 cases, 28.3% were admitted to the Ansan CTC; 84.8% of those patients were discharged and 15.2% were transferred to hospitals. The median length of stay was 10 days. Most transfers were decided within 1 to 2 days of CTC admission. In 18.5% of patients, medication was required to treat COVID-19 symptoms.The Ansan CTC ensures efficient resource use by focusing on mild and asymptomatic COVID-19 patients, especially foreigners, in an environment combining elements of the hospital and home.,15 Medical resources tend to be in particular demand during a pandemic.,17 Victims of other types of disasters tend to be treated only once, whereas for pandemics at least 2 weeks of isolation and treatment may be needed. As a lack of medical resources increases casualties, effective preparation and deployment thereof is important.,19 Recent reports have discussed pandemic situations in Korea and other countries in the context of surge capacity.,10–12,20It can be disastrous if medical resource demand exceeds availability.,11 However, to prevent the spread of infection effectively, Korea has instead established CTCs in existing accommodation facilities to quarantine patients. Medical staff use video calls to monitor patients and provide the necessary treatment. Korea had achieved a low COVID-19 mortality rate of 2% by August 2020 due to the provision of both CTC and hospital care.During the COVID-19 pandemic, most countries have established self-quarantine procedures for the management of mild and asymptomatic patients. Managing the constant stream of COVID-19-infected individuals from other countries remains a challenge. Few studies have explored the management of foreign patients, but it has been demonstrated that mild and asymptomatic patients can be safely managed in CTCs.,4,7,12 Thus, the Ansan CTC is designed exclusively for mild and asymptomatic foreign patients.Even during a pandemic, some people will continue to travel between countries. Third, the Ansan CTC provides patients with a variety of dietary options, including halal, vegetarian, and Korean. This is important because Muslims eat only halal food, Hindus cannot eat beef, and vegetarians obviously eat only vegetarian food.The Ansan CTC differs from other CTCs due to its use of non-face-to-face telemedicine to discuss all treatments with patients. Medical staff do not enter the patient zone, except in emergency situations; this reduces their workload. Second, routine PCR testing is not performed at the Ansan CTC due to the difficulties for medical staff of wearing level D PPE and the necessity of contacting patients for tests on an individual basis. At the Ansan CTC, patients are released from quarantine based on their clinical progress. To this end, chest X-ray is performed 2 or 3 times a week, depending on the volume of patients. For the Seoul CTC, which is used for South Korean patients and has a much higher workload than the Ansan CTC, PCR tests and chest X-rays are typically performed every 2 days.,4,7,12 Compared to patients who are discharged, the patients transferred to other hospitals are older and have significantly higher systolic blood pressure. In more than half of the cases, patients are transferred either due to uncontrolled blood pressure or worsening COVID-19 symptoms. Along with stratifying by severity, comorbidities should also be considered. According to the KCDC criteria, patients with mild symptoms and 1 or more comorbidities are admitted to the Ansan CTC, but it is difficult to control high blood pressure with oral medications alone. Other reasons for transfer include mastitis, anxiety, and depressive episodes. There have been no reported deaths among patients discharged from CTCs, including the Ansan CTC.,4,7,12 During the transfer process, it is difficult to determine bed availability because the medical staff at the Ansan CTC do not have access to real-time information on bed or hospital availability.Nearly 85% of patients are discharged from the Ansan CTC; around 15% are transferred to other hospitals, far higher than the rate of 2% to 10% reported by other studies.; CTCs better prevent COVID-19 transmission in South Korea compared to the measures used in other countries.Based on the patient transfers at our CTC, pre-triage and resource availability are important considerations in the response to a disaster. Triage failure can lead to unnecessary transfer of patients, resulting in wasted medical resources. Through triage, CTCs can easily quarantine and manage mild and asymptomatic patients, thereby preventing overuse of hospital resources. CTCs use more resources compared to simply quarantining mild and asymptomatic symptoms in their own homes, as done in other countries. However, such self-quarantine may fail to prevent the transmission of infectionCurrently, the movement of citizens between countries is limited, but this should improve on resolution of the COVID-19 pandemic. However, this may increase the transmission of infections. This report could be instructive to that end, by demonstrating that a hybrid self-quarantine and hospitalization environment is an effective way to care for patients. It is important to provide suitable food for foreign COVID-19 patients in accordance with their country of origin, and to establish admission criteria and monitor their condition daily, including through video calls.4.1The first limitation of this study is that the patients do not undergo blood tests, that is, there are no laboratory findings and the degree of viral load is unknown, so decisions regarding patient transfer are made based on symptoms alone. In addition, patients may give a false report of their symptoms and body temperature to ensure discharge. This could be addressed in the future by using Bluetooth devices to measure vital signs. Second, our CTC, located near Incheon International Airport, is designed for foreign patients, so the results may not be generalizable to other CTCs. Third, unlike some other CTCs, our center does not provide psychiatric counseling or medication due to difficulties with the storage of psychotropic drugs and communication in foreign languages. Patients with psychiatric issues are transferred to another hospital. Finally, to determine the need for surge capacity, further studies are required.5Even during the COVID-19 pandemic, individuals may have to travel between countries for various reasons, so a continuous influx of foreign patients with COVID-19 into South Korea is likely. CTCs can be an effective option for providing foreign patients with medical resources. This report should be instructive with respect to the operation of CTCs for foreign patients with COVID-19.Conceptualization: Hyun Noh.Data curation: Han Bit Kim, Sangsoo Han, Heejun Shin, Young Hwan Lee, Kyung Min Lee, Jae Ryoung Kwak, Young Soon Cho, Hojung Kim, Hoon Lim, Gi Woon Kim, Eunkyung Eo, Hyun Noh.Formal analysis: Han Bit Kim.Investigation: Han Bit Kim.Supervision: Hyun Noh.Writing – original draft: Han Bit Kim.Writing – review & editing: Han Bit Kim, Hyun Noh.