Lessons learned from reviewing a hospital's disaster response to the hydrofluoric acid leak in Gumi city in 2012.

BACKGROUND: This study analyzed the characteristics of hydrogen fluoride-exposed patients (HFEPs) treated in the emergency department (ED) of a local university hospital, and reviewed the hospital's disaster response according to space, staff, supplies, and systems (4Ss). METHODS: This retrospective observational chart review and descriptive study included 199 HFEPs among 2588 total ED patients who visited a local university emergency medical center for treatment between September 27, 2012 and October 20, 2012, following a hydrofluoric acid leak at the Hube Globe factory in Gumi City, Republic of Korea. Descriptive results concerning the 4Ss were obtained by interviewing ED specialist staff physicians on duty during the study period. In accordance with American Burn Association criteria, patients requiring burn center referral were assigned to the major burn group (MBG) as severe condition. RESULTS: During the acute phase (within 8 h after leak initiation), there were 43 patients in the ED, which was staffed with 3 doctors and 3 nurses, without 4S resources. Of these 43 patients, there were 8 HFEPs (100%) in the MBG and 0 in the non-MBG (NMBG). During the subacute phase (24 h after the acute phase), there were 262 patients in the ED including 167 HFEPs, of whom 45 (26.95%) were in the MBG and 122 (73.05%) were in the NMBG. The ED was then staffed with 6 doctors (3 on day shift and 3 on night shift) and 10 nurses (3 on day shift, 4 on evening shift, and 3 on night shift), and no 4S resources were available. Throughout the study period, no 4Ss were available. First, there was no expansion of ED space or secured disaster reserve beds. Second, there was no increase in manpower with duty time adjustments or duty relocation for ED working personnel. Third, there was no logistics reinforcement (e.g., antidote or personal protective equipment). Fourth, there were no disaster-related measures for the administration department, decontamination zone setup, safety diagnostic testing, or designated disaster triage implementation. CONCLUSIONS: The hospital's disaster response was insufficient for all aspects of the 4Ss. Detailed guidance concerning a hospital disaster management plan is required.

Versatile Yolk-Shell Encapsulation: Catalytic, Photothermal, and Sensing Demonstration.

Here, a novel, versatile synthetic strategy to fabricate a yolk-shell structured material that can encapsulate virtually any functional noble metal or metal oxide nanocatalysts of any morphology in a free suspension fashion is reported. This strategy also enables encapsulation of more than one type of nanoparticle inside a single shell, including paramagnetic iron oxide used for magnetic separation. The mesoporous organosilica shell provides efficient mass transfer of small target molecules, while serving as a size exclusion barrier for larger interfering molecules. Major structural and functional advantages of this material design are demonstrated by performing three proof-of-concept applications. First, effective encapsulation of plasmonic gold nanospheres for localized photothermal heating and heat-driven reaction inside the shell is shown. Second, hydrogenation catalysis is demonstrated under spatial confinement driven by palladium nanocubes. Finally, the surface-enhanced Raman spectroscopic detection of model pollutant by gold nanorods is presented for highly sensitive environmental sensing with size exclusion.

Mechanically programmed 2D and 3D liquid crystal elastomers at macro- and microscale via two-step photocrosslinking.

Liquid crystal elastomers (LCEs) are a unique class of active materials with the largest known reversible shape transformation in the solid state. The shape change of LCEs is directed by programming their molecular orientation, and therefore, several strategies to control LC alignment have been developed. Although mechanical alignment coupled with a two-step crosslinking is commonly adopted for uniaxially-aligned monodomain LCE synthesis, the fabrication of 3D-shaped LCEs at the macro- and microscale has been rarely accomplished. Here, we report a facile processing method for fabricating 2D and 3D-shaped LCEs at the macro- and microscales at room temperature by mechanically programming (i.e., stretching, pressing, embossing and UV-imprinting) the polydomain LCE, and subsequent photocrosslinking. The programmed LCEs exhibited a reversible shape change when exposed to thermal and chemical stimuli. Besides the programmed shape changes, the actuation strain can also be preprogrammed by adjusting the extent of elongation of a polydomain LCE. Furthermore, the LCE micropillar arrays prepared by UV-imprinting displayed a substantial change in pillar height in a reversible manner during thermal actuation. Our convenient method for fabricating reversible 2D and 3D-shaped LCEs from commercially available materials may expedite the potential applications of LCEs in actuators, soft robots, smart coatings, tunable optics and medicine.

Allergic contact dermatitis of both eyes caused by alcaftadine 0.25%: a case report.

BACKGROUND: To report the first case of allergic contact dermatitis (ACD) associated with alcaftadine 0.25% ophthalmic solution. CASE PRESENTATION: The patient was a 51-year-old woman with no previous history of side effects to ophthalmic antihistamine agents. She had been prescribed alcaftadine 0.25% for allergic conjunctivitis. On first application of the medication, she did not experience any cutaneous reaction. One day later, after the second alcaftadine 0.25% application, both eyelids became swollen, and erythematous changes were evident. On slit-lamp examination, conjunctival injection was noted in the absence of conjunctival swelling or any other findings. Fundus examination was unremarkable. To evaluate the cause of ACD, a patch test was performed and 48 h later was noted to be positive for alcaftadine 0.25%. Based on the positive patch test, the patient was diagnosed with ACD caused by alcaftadine 0.25%. After 9 days of treatment, the swelling and erythema completely resolved. CONCLUSIONS: Although there have been no previous reports of alcaftadine 0.25%-associated ACD, it should be suspected in patients with swelling and erythematous change of both eyes after using alcaftadine 0.25%.

Mechanism of Silica Nanoparticle-Induced Particulate Fouling in Vacuum Membrane Distillation.

Membrane distillation (MD) is a process driven by the vapor pressure difference dependent on temperature variation, utilizing a hydrophobic porous membrane. MD operates at low pressure and temperature, exhibiting resilience to osmotic pressure. However, a challenge arises as the membrane performance diminishes due to temperature polarization (TP) occurring on the membrane surface. The vacuum MD process leverages the application of a vacuum to generate a higher vapor pressure difference, enhancing the flux and mitigating TP issues. Nevertheless, membrane fouling leads to decreased performance, causing membrane wetting and reducing the ion removal efficiency. This study investigates membrane fouling phenomena induced by various silica nanoparticle sizes (400, 900, and 1300 nm). The patterns of membrane fouling, as indicated by the flux reduction, vary depending on the particle size. Distinct MD performances are observed with changes in the feed water temperature and flow rate. When examining the membrane fouling mechanism for particles with a porosity resembling actual particulate materials, a fouling form similar to the solid type is noted. Therefore, this study elucidates the impact of particulate matter on membrane fouling under diverse conditions.

Reliability of ChatGPT for performing triage task in the emergency department using the Korean Triage and Acuity Scale.

Background: Artificial intelligence (AI) technology can enable more efficient decision-making in healthcare settings. There is a growing interest in improving the speed and accuracy of AI systems in providing responses for given tasks in healthcare settings. Objective: This study aimed to assess the reliability of ChatGPT in determining emergency department (ED) triage accuracy using the Korean Triage and Acuity Scale (KTAS). Methods: Two hundred and two virtual patient cases were built. The gold standard triage classification for each case was established by an experienced ED physician. Three other human raters (ED paramedics) were involved and rated the virtual cases individually. The virtual cases were also rated by two different versions of the chat generative pre-trained transformer (ChatGPT, 3.5 and 4.0). Inter-rater reliability was examined using Fleiss' kappa and intra-class correlation coefficient (ICC). Results: The kappa values for the agreement between the four human raters and ChatGPTs were .523 (version 4.0) and .320 (version 3.5). Of the five levels, the performance was poor when rating patients at levels 1 and 5, as well as case scenarios with additional text descriptions. There were differences in the accuracy of the different versions of GPTs. The ICC between version 3.5 and the gold standard was .520, and that between version 4.0 and the gold standard was .802. Conclusions: A substantial level of inter-rater reliability was revealed when GPTs were used as KTAS raters. The current study showed the potential of using GPT in emergency healthcare settings. Considering the shortage of experienced manpower, this AI method may help improve triaging accuracy.

Removal Efficiency of Bottom Ash and Sand Mixtures as Filter Layers for Fine Particulate Matter.

Permeable pavement is a technology that allows rainwater to infiltrate into the pavement. Permeable pavements not only help reduce surface runoff by allowing rainwater to infiltrate into the pavement, but also improve water quality with the filter layer that removes particulate matter pollutants. This study evaluated the particulate matter removal efficiency of bottom ash-sand mixtures as filter layers for removing fine (≤10 µm) or ultrafine (≤2.5 µm) particulate matter in the laboratory. Five filter media were tested: silica sand, bottom ash, and bottom ash-sand mixtures with 30:70, 50:50, and 70:30 ratios. The mixed filters exhibited more consistent and stable particulate matter removal efficiency over time than either the uniform sand or bottom ash filter. The 50:50 bottom ash-sand mixture demonstrated removal rates of 58.05% for 1.8 µm particles, 93.92% for 10 µm particles, and 92.45% for 60 µm particles. These findings highlight the potential of bottom ash-sand mixtures as effective filter media for removing PM10 road dust, although field validation with actual pavement systems is necessary.

Fabrication of Yolk-Shell Structure with Multifarious Nanoparticles via Double-Layered Encapsulation Strategy.

The post-encapsulation method (such as single-layered encapsulation) is a promising strategy to synthesize yolk-shell structures that protect functional nanoparticles by the molecular sieving effect. However, this method exhibited limited loading capacity and nonuniform encapsulation during the co-encapsulation of various nanoparticles owing to the insufficient surface area for nanoparticle attachment. To address these limitations, we proposed a double-layered encapsulation method comprising an increased number of silica template layers and separate attachment of multifarious nanoparticles to different layers. Compared with conventional methods, this strategy can precisely adjust the ratio of encapsulated nanoparticles and increase the loading amount, which improves the functionality of yolk-shell structures, such as the photothermal properties of gold nanoparticle-encapsulated yolk-shell structures (∼69%). We describe, for the first time, the precise control of the ratio of encapsulated nanoparticles and the loading of numerous nanoparticles. Consequently, this strategy has significant potential for various applications of yolk-shell structures.

A Preliminary Evaluation of the Diagnostic Performance of a Smartphone-Based Machine Learning-Assisted System for Evaluation of Clinical Activity Score in Digital Images of Thyroid-Associated Orbitopathy.

Background: We previously developed a machine learning (ML)-assisted system for predicting the clinical activity score (CAS) in thyroid-associated orbitopathy (TAO) using digital facial images taken by a digital single-lens reflex camera in a studio setting. In this study, we aimed to apply this system to smartphones and detect active TAO (CAS ≥3) using facial images captured by smartphone cameras. We evaluated the performance of our system on various smartphone models and compared it with the performance of ophthalmologists with varying clinical experience. Methods: We applied the preexisting ML architecture to classify photos taken with smartphones (Galaxy S21 Ultra, iPhone 12 pro, iPhone 11, iPhone SE 2020, Galaxy M20, and Galaxy A21S). The performance was evaluated with smartphone-captured images from 100 patients with TAO. Three ophthalmology residents, three general ophthalmologists with <5 years of clinical experience, and three oculoplastic specialists independently interpreted the same set of images taken under a studio environment and compared their results with those generated by the smartphone-based ML-assisted system. Reference CAS was determined by a consensus of three oculoplastic specialists. Results: Active TAO (CAS ≥3) was identified in 28 patients. Smartphone model used in capturing facial images influenced active TAO detection performance (F1 score 0.59-0.72). The smartphone-based system showed 74.5% sensitivity, 84.8% specificity, and F1 score 0.70 on top three smartphones. On images from all six smartphones, average sensitivity, specificity, and F1 score were 71.4%, 81.6%, and 0.66, respectively. Ophthalmology residents' values were 69.1%, 55.1%, and 0.46. General ophthalmologists' values were 61.9%, 79.6%, and 0.55. Oculoplastic specialists' values were 73.8%, 90.7%, and 0.75. This smartphone-based ML-assisted system predicted CAS within 1 point of reference CAS in 90.7% using facial images from smartphones. Conclusions: Our smartphone-based ML-assisted system shows reasonable accuracy in detecting active TAO, comparable with oculoplastic specialists and outperforming residents and general ophthalmologists. It may enable reliable self-monitoring for disease activity, but confirmatory research is needed for clinical application.

Cold-Responsive Hyaluronated Upconversion Nanoplatform for Transdermal Cryo-Photodynamic Cancer Therapy.

Cryotherapy leverages controlled freezing temperature interventions to engender a cascade of tumor-suppressing effects. However, its bottleneck lies in the standalone ineffectiveness. A promising strategy is using nanoparticle therapeutics to augment the efficacy of cryotherapy. Here, a cold-responsive nanoplatform composed of upconversion nanoparticles coated with silica - chlorin e6 - hyaluronic acid (UCNPs@SiO2-Ce6-HA) is designed. This nanoplatform is employed to integrate cryotherapy with photodynamic therapy (PDT) in order to improve skin cancer treatment efficacy in a synergistic manner. The cryotherapy appeared to enhance the upconversion brightness by suppressing the thermal quenching. The low-temperature treatment afforded a 2.45-fold enhancement in the luminescence of UCNPs and a 3.15-fold increase in the photodynamic efficacy of UCNPs@SiO2-Ce6-HA nanoplatforms. Ex vivo tests with porcine skins and the subsequent validation in mouse tumor tissues revealed the effective HA-mediated transdermal delivery of designed nanoplatforms to deep tumor tissues. After transdermal delivery, in vivo photodynamic therapy using the UCNPs@SiO2-Ce6-HA nanoplatforms resulted in the optimized efficacy of 79% in combination with cryotherapy. These findings underscore the Cryo-PDT as a truly promising integrated treatment paradigm and warrant further exploring the synergistic interplay between cryotherapy and PDT with bright upconversion to unlock their full potential in cancer therapy.

Silica-Based Advanced Nanoparticles For Treating Ischemic Disease.

Recently, various attempts have been made to apply diverse types of nanoparticles in biotechnology. Silica nanoparticles (SNPs) have been highlighted and studied for their selective accumulation in diseased parts, strong physical and chemical stability, and low cytotoxicity. SNPs, in particular, are very suitable for use in drug delivery and bioimaging, and have been sought as a treatment for ischemic diseases. In addition, mesoporous silica nanoparticles have been confirmed to efficiently deliver various types of drugs owing to their porous structure. Moreover, there have been innovative attempts to treat ischemic diseases using SNPs, which utilize the effects of Si ions on cells to improve cell viability, migration enhancement, and phenotype modulation. Recently, external stimulus-responsive treatments that control the movement of magnetic SNPs using external magnetic fields have been studied. This review addresses several original attempts to treat ischemic diseases using SNPs, including particle synthesis methods, and presents perspectives on future research directions.

Encapsulated triplet-triplet annihilation-based upconversion in the aqueous phase for sub-band-gap semiconductor photocatalysis.

We herein report the first instance of aqueous-phase photosensitization of semiconductor photocatalysts (WO(3) loaded with Pt) through triplet-triplet annihilation (TTA)-based upconversion of sub-band-gap photons. The TTA-based upconversion (UC) was achieved in the aqueous phase by encapsulating the solvent phase containing a benchmark platinum(II) octaethylporphyrin/9,10-diphenylanthracene sensitizer/acceptor pair in a rigid polymer shell in the form of aqueous dispersible microcapsules. A mixture of hexadecane and polyisobutylene was used as the inner solvent phase. This eliminated the need for the deoxygenation step that is essential for existing TTA-based UC processes and enabled stable UC to occur even after a month of exposure to the ambient environment. The photoluminescence properties were examined, and UC-assisted photochemical production of hydroxyl radical from green (532 nm) light irradiation was demonstrated for the first time.

Engineering light: advances in wavelength conversion materials for energy and environmental technologies.

Upconversion photoluminescence (UC) occurs in optical materials that are capable of absorbing low energy photons and emitting photons of higher energy and shorter wavelength, while downconversion (DC) materials may absorb one high energy photon and emit two of lower energy for quantum yields exceeding unity. These wavelength conversion processes allow us to transform electromagnetic radiation so it may be more effectively utilized by light-capturing devices and materials. Progress in designing more efficient organic and inorganic photochemical conversion systems has initiated a recent surge in attempts to apply these processes for practical uses, including enhancement of many energy and environmental technologies. In this review, we introduce important concepts in UC and DC materials and discuss the current status and challenges toward the application of wavelength conversion to solar cells, photocatalysis, and antimicrobial surfaces.

Silica-Capped and Gold-Decorated Silica Nanoparticles for Enhancing Effect of Gold Nanoparticle-Based Photothermal Therapy.

BACKGROUND: Various methods based on gold nanoparticles (AuNPs) have been applied to enhance the photothermal effect. Among these methods, combining gold nanoparticles and stem cells has been suggested as a new technique for elevating the efficiency of photothermal therapy (PT) in terms of enhancing tumor targeting effect. However, to elicit the efficiency of PT using gold nanoparticles and stem cells, delivering large amounts of AuNPs into stem cells without loss should be considered. METHODS: AuNPs, AuNPs-decorated silica nanoparticles, and silica-capped and AuNPs-decorated silica nanoparticles (SGSs) were synthesized and used to treat human mesenchymal stem cells (hMSCs). After evaluating physical properties of each nanoparticle, the concentration of each nanoparticle was estimated based on its cytotoxicity to hMSCs. The amount of AuNPs loss from each nanoparticle by exogenous physical stress was evaluated after exposing particles to a gentle shaking. After these experiments, in vitro and in vivo photothermal effects were then evaluated. RESULTS: SGS showed no cytotoxicity when it was used to treat hMSCs at concentration up to 20 µg/mL. After intravenous injection to tumor-bearing mice, SGS-laden hMSCs group showed significantly higher heat generation than other groups following laser irradiation. Furthermore, in vivo photothermal effect in the hMSC-SGS group was significantly enhanced than those in other groups in terms of tumor volume decrement and histological outcome. CONCLUSION: Our results suggest that additional silica layer in SGSs could protect AuNPs from physical stress induced AuNPs loss. The strategy applied in SGS may offer a prospective method to improve PT.

Nanoencapsulated Phase-Change Materials: Versatile and Air-Tolerant Platforms for Triplet-Triplet Annihilation Upconversion.

Efficient and long-term stable triplet-triplet annihilation upconversion (TTA-UC) can be achieved by effectively protecting the excited organic triplet ensembles from photoinduced oxygen quenching, and discovery of a new material platform that promotes TTA-UC in ambient conditions is of paramount importance for practical applications. In this study, we present the first demonstration of an organic nonparaffin phase-change material (PCM) as an air-tolerant medium for TTA-UC with a unique solid-liquid phase transition in response to temperature variation. For the proposed concept, 2,4-hexadien-1-ol is used and extensively characterized with several key features, including good solvation capacity, mild melting point (30.5 °C), and exclusive antioxidant property, enabling a high-efficiency, low-threshold, and photostable TTA-UC system without energy-intensive degassing processes. In-depth characterization reveals that the triplet diffusion among the transient species, i.e., 3sensitizer* and 3acceptor*, is efficient and well protected from oxygen quenching in both aerated liquid- and solid-phase 2,4-hexadien-1-ol. We also propose a new strategy for the nanoencapsulation of PCM by employing hollow mesoporous silica nanoparticles as vehicles. This scheme is applicable to both aqueous- and solid-phase TTA-UC systems as well as suitable for various applications, such as thermal energy storage and smart drug delivery.

Enzyme-immobilized nanofiltration membrane to mitigate biofouling based on quorum quenching.

Recently, enzymatic quorum quenching (in the form of a free enzyme or an immobilized form on a bead) was successfully applied to a submerged membrane bioreactor with a microfiltration membrane for wastewater treatment as a novel approach to control membrane biofouling. In this study, a quorum quenching enzyme (acylase) was directly immobilized onto a nanofiltration membrane to mitigate biofouling in a nanofiltration process. In a flow cell experiment, the acylase-immobilized membrane with quorum quenching activity prohibited the formation of mushroom-shaped mature biofilm due to the reduced secretion of extracellular polymeric substances (EPS). The acylase-immobilized membrane maintained more than 90% of its initial enzyme activity for more than 20 iterative cycles of reaction and washing procedure. In the lab-scale continuous crossflow nanofiltration system operated at a constant pressure of 2 bar, the flux with the acylase-immobilized nanofiltration (NF) membrane was maintained at more than 90% of its initial flux after a 38-h operation, whereas that with the raw NF membrane decreased to 60% accompanied with severe biofouling. The quorum quenching activity of the acylase-immobilized membrane was also confirmed by visualizing the spatial distribution of cells and polysaccharides on the surface of each membrane using confocal laser scanning microscopy (CLSM) image analysis technique.

Recent Advances in Hollow Gold Nanostructures for Biomedical Applications.

The localized surface plasmon resonance of metallic nanoparticles has attracted much attention owing to its unique characteristics, including the enhancement of signals in sensors and photothermal effects. In particular, hollow gold nanostructures are highly promising for practical applications, with significant advantages being found in their material properties and structures: 1) the interaction between the outer surface plasmon mode and inner cavity mode leads to a greater resonance, allowing it to absorb near-infrared light, which can readily penetrate tissue; 2) it has anti-corrosiveness and good biocompatibility, which makes it suitable for biomedical applications; 3) it shows a reduced net density and large surface area, allowing the possibility of nanocarriers for drug delivery. In this review, we present information on the classification, characteristics, and synthetic methods of hollow gold nanostructures; discuss the recent advances in hollow gold nanostructures in biomedical applications, including biosensing, bioimaging, photothermal therapy, and drug delivery; and report on the existing challenges and prospects for hollow gold nanostructures.

Evaluating the Effectiveness of the Chemical-Mass Casualty Incident Response Education Module (C-MCIREM): A Pilot Simulation Study With a Before and After Design.

Background With the occurrence of a number of major disasters around the world, there is growing interest in chemical disaster medicine. In South Korea, there is a training program for mass casualty incidents (MCI) and backup by legal regulations by the Framework Act on the Management of Disasters and Safety. However, there is no program focusing on chemical disasters. Thus, the authors newly created a program, the Chemical-Mass Casualty Incident Response Education Module (C-MCIREM) in September 2019. This was a pilot study to verify the educational effect of the program. Method A pre/post study was conducted of a chemical MCI training program based on simulation. A total of 25 representative and qualified participants were recruited from fire departments, administrative staff of public health centers, and healthcare workers of hospitals in the Gyeonggi-do province of South Korea. They participated in a one-day training program. A knowledge test and confidence survey were provided to participants just before training, and again immediately following the training online. The authors compared improvements of pre/post-test results. In the tabletop drill exercise, quantified qualitative analyses were used to measure the educational effect on the participants. Results In the knowledge test, the mean (standard deviation) scores for all 25 participants at baseline and after training were 41.72 (15.186) and 77.96 (11.227), respectively (p < 0.001). In the confidence survey for chemical MCI response for all 25 participants, all the sub-items concerning personal protective equipment selection, antidote selection, antidote stockpiling and passing on knowledge to colleagues, zone setup and decontamination, and chemical triage were improved compared to the baseline score (p < 0.001). The tabletop exercise represented a prehospital setting and had 11 participants. The self-efficacy qualitative survey showed pre- and post-exercise scores of 64/100 and 84/100 respectively. For a hospital setting exercise, it had 14 participants. The survey showed pre/post-exercise scores of 26/100 and 73/100 respectively. Twenty-two (88%) participants responded to the final satisfaction survey, and their overall mean scores regarding willingness to recommend this training program to others, overall satisfaction with theoretical education, overall satisfaction with tabletop drill simulation, and opinion about whether policymakers need this training were all over 8 out of 10 respectively. Conclusion C-MCIREM, the newly created chemical MCI program, provided effective education to the selected 25 participants among Korean chemical MCI responders in terms of both knowledge and practice at a single pilot trial. Participants were highly satisfied with the educational material and their confidence in disaster preparedness was clearly improved. In order to prove the universal educational effect of this C-MCIREM in the future, more education is needed.

Yolk-Shell-Type Gold Nanoaggregates for Chemo- and Photothermal Combination Therapy for Drug-Resistant Cancers.

Epithelial ovarian cancer is a gynecological cancer with the highest mortality rate, and it exhibits resistance to conventional drugs. Gold nanospheres have gained increasing attention over the years as photothermal therapeutic nanoparticles, owing to their excellent biocompatibility, chemical stability, and ease of synthesis; however, their practical application has been hampered by their low colloidal stability and photothermal effects. In the present study, we developed a yolk-shell-structured silica nanocapsule encapsulating aggregated gold nanospheres (aAuYSs) and examined the photothermal effects of aAuYSs on cell death in drug-resistant ovarian cancers both in vitro and in vivo. The aAuYSs were synthesized using stepwise silica seed synthesis, surface amino functionalization, gold nanosphere decoration, mesoporous organosilica coating, and selective etching of the silica template. Gold nanospheres were agglomerated in the confined silica interior of aAuYSs, resulting in the red-shifting of absorbance and enhancement of the photothermal effect under 808 nm laser irradiation. The efficiency of photothermal therapy was first evaluated by inducing aAuYS-mediated cell death in A2780 ovarian cancer cells, which were cultured in a two-dimensional culture and a three-dimensional spheroid culture. We observed that photothermal therapy using aAuYSs together with doxorubicin treatment synergistically induced the cell death of doxorubicin-resistant A2780 cancer cells in vitro. Furthermore, this type of combinatorial treatment with photothermal therapy and doxorubicin synergistically inhibited the in vivo tumor growth of doxorubicin-resistant A2780 cancer cells in a xenograft transplantation model. These results suggest that photothermal therapy using aAuYSs is highly effective in the treatment of drug-resistant cancers.

Effects of the formation of reactive chlorine species on oxidation process using persulfate and nano zero-valent iron.

The chloride ion (Cl-) is a matrix ion that plays crucial roles in radical-based oxidation processes used to treat brackish or saline water. Here, the effects of the formation of reactive chlorine species on the performance of and reaction mechanisms involved in persulfate/nano zero-valent iron process were evaluated by investigating the reaction kinetics and performing reactive species scavenging tests. The phenol oxidation rate increased markedly in the early reaction stage in the presence of 25-200 mM of Cl-. This was because excess sulfate radicals (SO4-) reacted with Cl- to produce short-lived reactive chlorine species such as Cl and Cl2- rather than being scavenged by Fe2+ or other SO4-. The reactive chlorine species caused OH to form through radical propagation reactions. The total numbers of reactive species involved in phenol oxidation were higher at brackish to weakly saline Cl- concentrations than at lower and higher Cl- concentrations. At high Cl- concentrations (>400 mM), the phenol oxidation rate decreased because most of the SO4- reacted with Cl- to give large amounts of weaker oxidants such as Cl2- and HOCl. Acceleration of Fe corrosion by Cl- negligibly affected the persulfate/nano zero-valent iron oxidation process.