ABSTRACT
To present an efficient method for fabricating artificial kidney stones with acoustic and physical properties to assess their fragmentation efficiency under shock waves and laser lithotripsy for very hard stones. The mixture ratio of super-hard plaster and water was adjusted to produce artificial kidney stones for comparison with > 95% human genuine calcium oxalate monohydrate (COM) and uric acid (UA) stones. Acoustic and physical properties, such as wave speed, stone hardness, density, compressive strength, and stone-free rates under shock-wave and laser lithotripsy, were assessed. The longitudinal wave speed of artificial stones prepared at a plaster-to-water ratio of 15:3 closely matched that of COM stones. Similarly, the transverse wave speed of artificial stones prepared at a plaster-to-water ratio of 15:3 to 15:5 aligned with that of COM stones. Stone fragmentation using shock-wave of artificial stones with mixed ratios ranging from 15:3 to 15:5 resembled that of COM stones. The Vickers hardness was similar to that of artificial stones produced with a mixing ratio of 15:3, similar to that of COM stones, while that of artificial stones produced with a mixing ratio of 15:5 was similar to that of UA stones. Density-wise, artificial stones with mixing ratios of 15:4 and 15:5 resembled COM stones. Compressive strength test results did not confirm the similarity between natural and artificial stones. The stone fragmentation using laser showed that stones produced with higher moisture content at a mixing ratio of 15:6 were similar to COM stones. This novel method for fabricating artificial kidney stones could be used to provide reliable materials for lithotripsy research.
Subject(s)
Calcium Oxalate , Kidney Calculi , Lithotripsy, Laser , Kidney Calculi/therapy , Kidney Calculi/chemistry , Humans , Lithotripsy, Laser/methods , Lithotripsy, Laser/instrumentation , Calcium Oxalate/analysis , Uric Acid/analysis , Uric Acid/chemistry , Hardness , Acoustics , Lithotripsy/methods , Lithotripsy/instrumentationABSTRACT
Tumor heterogeneity and drug resistance have been invincible features of cancer for its complete cure. Despite the advent of immunotherapy, the expansion and diversification of cancer cells evolved even in the absence or presence of drug treatment discourage additional therapeutic interventions. For the eradication of cancer cells, therefore, an 'all-at-once' strategy is required, which exploits both target-selective chemotherapy and non-selective physicotherapy. Multifactorial microcapsules comprising gold nanoparticles (AuNPs) and a self-assembly protein of α-synuclein (αS) were fabricated, in which hydrophobic and hydrophilic drugs could be separately encapsulated by employing lipid-based inverted micelles (IMs). Their combined physico-chemical therapeutic effects were examined since they also contained both membrane-disrupting IMs and heat-generating AuNPs upon irradiation as physicotherapeutic agents. For the optimal enclosure of IMs containing hydrophilic drugs, a porous inner skeleton made of poly(lactic-co-glycolic acid) was introduced, which would play the roles of not only compartmentalizing the internal space but also enhancing proteolytic disintegration of the microcapsules to discharge and stabilize IMs to the outside. In fact, hydrophobic paclitaxel and hydrophilic doxorubicin showed markedly enhanced drug efficacy when delivered in the IM-containing microcapsules exhibiting the 'quantal' release of both drugs into the cells whose integrity could be also affected by the IMs. In addition, the remnants of αS-AuNP microcapsules produced via proteolysis also caused cell death through photothermal effect. The multifactorial microcapsules are therefore considered as a promising anti-cancer drug carrier capable of performing combinatorial selective and non-selective chemical and physical therapies to overcome tumor heterogeneity and drug resistance.
Subject(s)
Doxorubicin , Drug Carriers , Gold , Metal Nanoparticles , Neoplasms , Paclitaxel , Gold/chemistry , Humans , Drug Carriers/chemistry , Doxorubicin/administration & dosage , Doxorubicin/pharmacology , Doxorubicin/chemistry , Neoplasms/therapy , Neoplasms/drug therapy , Metal Nanoparticles/chemistry , Metal Nanoparticles/administration & dosage , Paclitaxel/administration & dosage , Paclitaxel/therapeutic use , alpha-Synuclein , Hydrophobic and Hydrophilic Interactions , Antineoplastic Agents/administration & dosage , Antineoplastic Agents/chemistry , Micelles , Polylactic Acid-Polyglycolic Acid Copolymer/chemistry , Cell Line, Tumor , CapsulesABSTRACT
BACKGROUND: This work aimed to identify a method to achieve improved stone targeting and safety in shockwave lithotripsy by accounting for respiration. METHODS: We set up an electromotive device simulating renal movement during respiration to place artificial stones within the phantom gel, measuring stone weight changes before and after shockwave exposure and the cavitation damage. We conducted clinical trials using respiratory masks and sensors to monitor and analyze patient respiration during shockwave lithotripsy. RESULTS: The in vitro efficiency of lithotripsy was higher when adjusted for respiration than when respiration was not adjusted for. Slow respiration showed the best efficiency with higher hit rates when not adjusted for respiration. Cavitation damage was also lowest during slow respiration. The clinical study included 52 patients. Respiratory regularity was maintained above 90% in regular respiration. When respiration was regular, the lithotripsy rate was about 65.6%, which stayed at about 40% when respiration was irregular. During the lithotripsy, the participants experienced various events, such as sleep, taking off their masks, talking, movement, coughing, pain, nervousness, and hyperventilation. The generation of shockwaves based on respiratory regularity could reduce pain in patients. CONCLUSION: These results suggest a more accurate lithotripsy should be performed according to respiratory regularity.
Subject(s)
Kidney Calculi , Lithotripsy , Humans , Kidney Calculi/therapy , Kidney , Lithotripsy/methods , Research Design , Phantoms, Imaging , Pain , Treatment OutcomeABSTRACT
OBJECTIVES: To investigate the relationship between Temporomandibular disorder (TMD) and associated comorbidities in groups matched according to age and sex. METHODS: Using data from the cross-sectional fifth Korea National Health and Nutrition Examination Survey (KNHANES). Of the 25,534 eligible KNHANES, 17,762 adults aged ≥19 years who responded to survey questionnaire on TMD and comorbidities. Subjects were classified into eight groups according to age and sex. Logistic regression analyses were performed to evaluate the association between TMD and comorbidities according to age and sex. RESULTS: Of the enrolled participants, 2,107 (11.86%) complained of ≥1 TMD symptoms. In all groups, odds ratios (ORs) for prevalence of TMD were >1 in those with tinnitus. Rhinitis was closely associated with TMD in 6 groups. ORs for TMD with comorbidities according to age and sex were as follows: hypertension, men aged 50-64 years (OR 0.62; CI 0.41-0.94); ischemic heart disease, men aged 35-49 years (4.38; 1.54-12.47); osteoarthritis, women aged 50-64 years (1.38; 1.03-1.86); diabetes mellitus, men aged 35-49 years (0.21; 0.05-0.88); depression, men aged 50-64 years (1.68; 1.00-2.83), women aged 35-49 years (1.39; 1.05-1.85) and women aged 65-80 years (2.01; 1.46-2.77); migraine, men aged 50-64 years (1.60; 1.14-2.25), women aged d35-49 years (1.44; 1.14-1.81) and women aged 35-49 years (1.43; 1.07-1.90); cold hypersensitivity in the hands and feet, men aged 19-34 years (1.64; 1.05-2.58), men aged 35-49 years (1.68; 1.04-2.70), men aged 65-80 years (1.74; 1.09-2.75) and women aged 35-49 years (1.45; 1.15-1.84); olfaction disorder, men aged 50-64 years (2.49; 1.39-4.43); voice disorder, men aged 50-64 years (2.25; 1.28-3.96) and women aged 65-80 years (1.69; 1.09-2.63). CONCLUSIONS: This study confirmed that the types and effects of comorbidities related to prevalence of TMD may differ according to the patient's age and sex and this result will increase the predictability of the onset of TMD.
Subject(s)
Sex Characteristics , Temporomandibular Joint Disorders , Adult , Humans , Male , Female , Cross-Sectional Studies , Nutrition Surveys , Temporomandibular Joint Disorders/complications , Republic of Korea/epidemiology , PrevalenceABSTRACT
In this study, we introduce a novel approach for synthesizing lignin-incorporated castor-oil-based cationic waterborne polyurethane (CWPU-LX), diverging significantly from conventional waterborne polyurethane dispersion synthesis methods. Our innovative method efficiently reduces the required solvent quantity for CWPU-LX synthesis to approximately 50% of that employed in traditional WBPU experimental procedures. By incorporating lignin into the polyurethane matrix using this efficient and reduced-solvent method, CWPU-LX demonstrates enhanced properties, rendering it a promising material for diverse applications. Dynamic interactions between lignin and polyurethane molecules contribute to improved mechanical properties, enhanced thermal stability, and increased solvent resistance. Dynamic interactions between lignin and polyurethane molecules contribute to improved tensile strength, up to 250% compared to CWPU samples. Furthermore, the inclusion of lignin enhanced thermal stability, showcasing a 4.6% increase in thermal decomposition temperature compared to conventional samples and increased solvent resistance to ethanol. Moreover, CWPU-LX exhibits desirable characteristics such as protection against ultraviolet light and antibacterial properties. These unique properties can be attributed to the presence of the polyphenolic group and the three-dimensional structure of lignin, further highlighting the versatility and potential of this material in various application domains. The integration of lignin, a renewable and abundant resource, into CWPU-LX exemplifies the commitment to environmentally conscious practices and underscores the significance of greener materials in achieving a more sustainable future.
ABSTRACT
Due to their mechanical robustness, biocompatibility, and nanoscale size, amyloid fibrils (AFs) have been considered as a potential nanomaterial for biological applications. Unfortunately, however, AFs are usually not fully extended because of their pre-mature breakage, which hampers their use to generate biocompatible suprastructures, although the amounts of AFs could be amplified via their self-propagation property. Here, we have demonstrated the full extension of AFs of α-synuclein (αS) by introducing a cysteine residue to its C-terminus which prevents the shear-induced fragmentation of AFs via site-directed disulfide bond formation on the exposed surface of AFs. These heat- and cold-resistant elongated AFs were entangled into self-healable hydrogels through a mild disulfide-exchange process in the presence of tris(2-carboxyethyl) phosphine, which subsequently developed into dye-absorbing aerogels upon freeze-drying without collapsing the three-dimensional internal fibrillar network. The resulting αS aerogel with high porosity and increased surface area was shown to be capable of absorbing both hydrophilic and hydrophobic substances. In addition, the aerogel was further engineered with 8-arm polyethylene glycol containing a sulfhydryl group to increase its drug loading capacity and protease susceptibility for drug unloading. The elongated AFs, therefore, have been suggested to play a pivotal component for the development of bio-nano-matrix for diverse biological applications including drug delivery, tissue engineering, and environmental remediation. STATEMENT OF SIGNIFICANCE: Due to accurate protein self-assembly process, α-synuclein forms an amyloid fibril which are the major component of Lewy bodies. In general, α-synuclein amyloid fibrils break under thermal fluctuations as these nanofibrils elongate to reach certain length. In this study, we have demonstrated the full extension of α-synuclein amyloid fibrils by introducing a cysteine residue to its C-terminus by forming site-directed disulfide bonds on the exposed surface of amyloid fibrils for the first time. The resulting elongated amyloid fibrils were mechanically robust and stable. By using elongated amyloid fibrils, we have made self-healable amyloid fibril hydrogel and dye-absorbing aerogel.
Subject(s)
Amyloid , alpha-Synuclein , Amyloid/chemistry , Cysteine , Disulfides , Hydrogels , alpha-Synuclein/chemistry , alpha-Synuclein/metabolismABSTRACT
BACKGROUND/AIM: Self-defense products that use high-intensity light are being developed. The intense light generated by the high-power light-emitting diodes (LEDs) of such self-defense products causes temporary blindness. However, few studies have been conducted on the visual safety of their devices. We, therefore, evaluated the effects of strong light of a short duration on the eyes of rabbits in this study. MATERIALS AND METHODS: The right eyes of 15 rabbits were irradiated for 5 s with a lighting device (25 W, 150 lm/W at 700 mA LED) and four eyes of two rabbits were non-irradiated as controls. Changes in the eye structure and function were evaluated before, and immediately, 30 min, 1 h, 24 h, 7 days and 14 days after light irradiation by full-field electroretinogram (ERG), slit-lamp biomicroscopy, and retinal camera. The thickness of the outer nuclear layer of the retina tissue was measured, and histopathological signs of retinal damage were analyzed. RESULTS: The ERG results showed that night vision was not affected. In day vision, the ERG waveform was temporarily affected immediately after light irradiation; however, it recovered within 24 h. No histopathological signs of damage were observed. CONCLUSION: Application of high-power LED light with short duration as used for self-defense was found to cause temporary phototoxicity, but safety was confirmed as vision recovered within 24 h.
Subject(s)
Electroretinography , Retinal Diseases , Animals , Light , Rabbits , RetinaABSTRACT
Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers worldwide, and its incidence is increasing. PDAC often shows resistance to several therapeutic modalities and a higher recurrence rate after surgical treatment in the early localized stage. Combination chemotherapy in advanced pancreatic cancer has minimal impact on overall survival. RNA interference (RNAi) is a promising tool for regulating target genes to achieve sequence-specific gene silencing. Here, we summarize RNAi-based therapeutics using nanomedicine-based delivery systems that are currently being tested in clinical trials and are being developed for the treatment of PDAC. Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) genome editing has been widely used for the development of cancer models as a genetic screening tool for the identification and validation of therapeutic targets, as well as for potential cancer therapeutics. This review discusses current advances in CRISPR/Cas9 technology and its application to PDAC research. Continued progress in understanding the PDAC tumor microenvironment and nanomedicine-based gene therapy will improve the clinical outcomes of patients with PDAC.
ABSTRACT
It is challenging to diagnose patients with pancreatic ductal adenocarcinoma (PDAC) early on, and their treatment is often complex. Gemcitabine (GEM) is the first-line treatment for PDAC, but its efficacy is limited in most patients due to the GEM resistance from KRAS and P53 gene mutations. We describe the correction of a double gene mutation and therapeutic effect for the GEM resistant PDAC. Bio-available nanoliposomes (NL) possessing Cas9-ribonucleoproteins and adenine-base editors were developed to conduct KRAS and P53 mutation gene editing directly. NLs were conjugated with EGFR antibodies to tumor-specific delivery, and the anti-cancer effect was verified in vitro and in vivo Model. Our GEM-combinatorial therapeutic strategies using double gene editing systems with one-shot may be a potent therapy for PDAC, overcoming chemoresistance.
Subject(s)
Carcinoma, Pancreatic Ductal , Pancreatic Neoplasms , Pharmaceutical Preparations , Carcinoma, Pancreatic Ductal/drug therapy , Carcinoma, Pancreatic Ductal/genetics , Cell Line, Tumor , Drug Resistance, Neoplasm/genetics , Gene Editing , Humans , Pancreatic Neoplasms/drug therapy , Pancreatic Neoplasms/geneticsABSTRACT
Full advantage of stretchable electronic devices can be taken when utilizing an intrinsically stretchable power source. High-performance stretchable supercapacitors with a simple structure and solid-state operation are good power sources for stretchable electronics. This study suggests a new type of intrinsically stretchable, printable, electroactive ink consisting of 1T-MoS2 and a fluoroelastomer (FE). The active material (1T-MoS2/FE) is made by fluorinating the metallic-phase MoS2 (1T-MoS2) nanosheets with the FE under high-power ultrasonication. The MoS2 in the 1T-MoS2/FE has unconventional crystal structures in which the stable cubic (1T) and distorted 2H structures were mixed. The printed line of the 1T-MoS2/FE on the porous stretchable Au collector electrodes is intrinsically stretchable at more than ε = 50% and has good specific capacitance (28 mF cm-2 at 0.2 mA cm-2) and energy density (3.15 mWh cm-3). The in-plane all-solid-state stretchable supercapacitor is stretchable at ε = 40% and retains its relative capacity (C/Co) by 80%. This printable device platform potentially opens up the in-plane fabrication of stretchable micro-supercapacitor devices for wearable electronic applications.
ABSTRACT
BACKGROUND: Recent paediatric and family medicine graduates report feeling unprepared to identify and address children and youth with developmental disorders. Developmental history taking and physical examination alone limit engagement with children and youth in an interactive manner to assess development. The paediatric developmental toolkit (PDT) was developed to provide trainees with the opportunity to interact with a child in a play-based manner. OBJECTIVES: The primary objective of this study was to determine the feasibility of PDT within clinical settings, and qualitatively explore how the PDT can be used by teachers and trainees. METHODS: Trainees and their clinical teachers participated in a qualitative study. Trainees used the PDT in clinical settings and were interviewed following their clinical encounters. Interactions between clinical teachers and trainees following the use of the PDT were also recorded. Teachers were interviewed following the trainees' case presentations and closures of clinic visits. Trainee interviews, teacher and trainee interactions, and teacher interviews were audiotaped, transcribed, and analyzed thematically. RESULTS: Nine trainees (six paediatric residents, two family medicine residents, and one clinical clerk medical student) and four developmental paediatricians participated in the study. Each trainee used the PDT twice in two different clinical encounters. All residents agreed the PDT enabled them to observe a child's developmental skills in a short period of time. Clinical teachers all felt the toolkit allowed trainees to more holistically consider a child's development and diagnosis. CONCLUSIONS: As medical education shifts to a competency-based education curriculum, the PDT is an innovative tool that can be used to enhance paediatric and family medicine residents' learning of child development by enabling opportunities for interaction with children.
ABSTRACT
Vertically aligned two-dimensional (2D) molybdenum disulfide nanoflowers (MoS2 NFs) have drawn considerable attention as a novel functional material with potential for next-generation applications owing to their inherently distinctive structure and extraordinary properties. We report a simple metal organic chemical vapor deposition (MOCVD) method that can grow high crystal quality, large-scale and highly homogeneous MoS2 NFs through precisely controlling the partial pressure ratio of H2S reaction gas, P SR, to Mo(CO)6 precursor, P MoP, at a substrate temperature of 250 °C. We investigate microscopically and spectroscopically that the S/Mo ratio, optical properties and orientation of the grown MoS2 NFs can be controlled by adjusting the partial pressure ratio, P SR/P MoP. It is also shown that the low temperature MOCVD (LT-MOCVD) growth method can regulate the petal size of MoS2 NFs through the growth time, thereby controlling photoluminescence intensity. More importantly, the MoS2 NFs/GaAs heterojunction flexible solar cell exhibiting a power conversion efficiency of â¼1.3% under air mass 1.5 G illumination demonstrates the utility of the LT-MOCVD method that enables the direct growth of MoS2 NFs on the flexible devices. Our work can pave the way for practical, easy-to-fabricate 2D materials integrated flexible devices in optical and photonic applications.
ABSTRACT
This study investigates the morphology, microstructure, compressive behavior, biocorrosion properties, and cytocompatibility of magnesium (Mg)-aluminum (Al) alloy (AE42) scaffolds for their potential use in biodegradable biomedical applications. Mg alloy scaffolds were successfully synthesized via a camphene-based freeze-casting process with precisely controlled heat treatment. The average porosity was approximately 52% and the median pore diameter was â¼13⯵m. Salient deformation mechanisms were identified using acoustic emission (AE) signals and adaptive sequential k-means (ASK) analysis. Twinning, dislocation slip, strut bending, and collapse were dominant during compressive deformation. Nonetheless, the overall compressive behavior and deformation mechanisms were similar to those of bulk Mg based on ASK analysis. The corrosion potential of the Mg alloy scaffold (-1.44â¯V) was slightly higher than that of bulk AE42 (-1.60â¯V), but the corrosion rate of the Mg alloy scaffold was faster than that of bulk AE42 due to the enhanced surface area of the Mg alloy scaffold. As a result of cytocompatibility evaluation following ISO10993-5, the concentration of the Mg alloy scaffold extract reducing cell growth rate to 50% (IC50) was 10.7%, which is higher (less toxic) than 5%, suggesting no severe inflammation by implantation into muscle.
Subject(s)
Alloys/chemistry , Aluminum/chemistry , Biocompatible Materials/chemistry , Magnesium/chemistry , Mechanical Phenomena , Corrosion , Electrochemistry , Materials TestingABSTRACT
We synthesized Fe foams using water suspensions of micrometric Fe2O3 powder by reducing and sintering the sublimated Fe oxide green body to Fe under 5% H2/Ar gas. The resultant Fe foam showed aligned lamellar macropores replicating the ice dendrites. The compressive behavior and deformation mechanism of the synthesized Fe foam were studied using an acoustic emission (AE) method, with which we detected sudden localized structural changes in the Fe foam material. The evolution of the deformation mechanism was elucidated using the adaptive sequential k-means (ASK) algorithm; specifically, the plastic deformation of the cell struts was followed by localized cell collapse, which eventually led to fracturing of the cell walls. For potential biomedical applications, the corrosion and biocompatibility characteristics of the two synthesized Fe foams with different porosities (50% vs. 44%) were examined and compared. Despite its larger porosity, the superior corrosion behavior of the Fe foam with 50% porosity can be attributed to its larger pore size and smaller microscopic surface area. Based on the cytotoxicity tests for the extracts of the foams, the Fe foam with 44% porosity showed better cytocompatibility than that with 50% porosity.
Subject(s)
Acoustics , Biocompatible Materials/chemistry , Iron/chemistry , Viscoelastic Substances/chemistry , Animals , Biocompatible Materials/toxicity , Cell Line , Compressive Strength , Corrosion , Electrochemistry/methods , Ferric Compounds/chemistry , Fibroblasts , Iron/toxicity , Materials Testing , Mice , Porosity , X-Ray DiffractionABSTRACT
OBJECTIVES: This placebo-controlled randomized double-blinded clinical study assessed the analgesic efficacy of intramuscular morphine in TMD patients with myofascial pain and sex-dependent responses of the morphine treatment. SUBJECTS AND METHODS: Men and women with TMD were treated with morphine (1.5 or 5 mg), lidocaine, or saline in the masseter muscle. VAS of pain intensity, PPT, and PPtol were compared between treatment groups and gender. An additional group was treated with morphine in the trapezius muscle to evaluate the systemic effect of morphine that may reduce pain in the masseter muscle. RESULTS: There was a significant difference in VAS scores between the morphine 5 mg group and the saline group favoring morphine, but not between the morphine 5 mg and lidocaine. Morphine 1.5 and 5 mg treatments led to consistently and significantly elevated PPT and PPtol measures in men, but not in women. Morphine administered in the trapezius muscle did not affect the outcome measures. CONCLUSION: A single dose intramuscular morphine produced analgesic effects up to 48 hr in patients with myofascial pain. Intramuscular morphine elevated mechanical pain threshold and tolerance in the masseter only in male patients, suggesting sex differences in local morphine effects. No systemic effect of intramuscular morphine was detected.
Subject(s)
Analgesics, Opioid/therapeutic use , Facial Pain/drug therapy , Morphine/therapeutic use , Pain Threshold/drug effects , Temporomandibular Joint Disorders/drug therapy , Adult , Analgesics, Opioid/administration & dosage , Anesthetics, Local/therapeutic use , Double-Blind Method , Facial Pain/etiology , Female , Humans , Injections, Intramuscular , Lidocaine/therapeutic use , Male , Masseter Muscle , Morphine/administration & dosage , Pain Measurement , Pilot Projects , Pressure/adverse effects , Sex Factors , Temporomandibular Joint Disorders/complications , Young AdultABSTRACT
Targeted drug delivery has been an important issue for tumor therapy including photodynamic therapy (PDT). The purpose of our study is to increase the targeting efficiency of photosensitizer (PS) using folate-modified nanoparticles (NPs) to tumor site in vivo. Folate receptor is over-expressed on the surface of many human cancer cells. We prepared poly (lactic-co-glycolic acid) (PLGA) NPs containing pheophorbide a (Pba), a PS that is used in PDT and generates free radical for killing cancer cells. The surface of NPs was composed of phospholipids modified with polyethylene glycol (PEG) and folate (FA). The size of the resulting FA-PLGA-Pba NPs was about 200â¯nm in PBS at pH 7.4 and they were stable for long time. They showed faster cellular uptake to MKN28 human gastric cancer cell line than control PLGA-Pba NPs by high-affinity binding with folate receptors on cell surface. In MTT assay, FA-PLGA-Pba NPs also showed enhanced tumor cell killing compared to control PLGA-Pba NPs. In vivo and ex vivo imaging showed high accumulation of FA-PLGA-Pba NPs in tumor site during 24â¯h after intravenous injection to MKN28 tumor-bearing mice model. These results demonstrate that our FA-PLGA-Pba NPs are useful for tumor-targeted delivery of PS for cancer treatment by PDT.
Subject(s)
Chlorophyll/analogs & derivatives , Folic Acid/chemistry , Lactic Acid/chemistry , Nanoparticles/chemistry , Photosensitizing Agents/administration & dosage , Polyglycolic Acid/chemistry , Stomach Neoplasms/drug therapy , Animals , Cell Line, Tumor , Chlorophyll/administration & dosage , Chlorophyll/pharmacokinetics , Chlorophyll/therapeutic use , Drug Carriers/chemistry , Drug Delivery Systems , Humans , Mice, Nude , Photochemotherapy , Photosensitizing Agents/pharmacokinetics , Photosensitizing Agents/therapeutic use , Polylactic Acid-Polyglycolic Acid Copolymer , Stomach Neoplasms/pathologyABSTRACT
Mesoscopic solar cells based on nanostructured oxide semiconductors are considered as a promising candidates to replace conventional photovoltaics employing costly materials. However, their overall performances are below the sufficient level required for practical usages. Herein, this study proposes an anodized Ti foam (ATF) with multidimensional and hierarchical architecture as a highly efficient photoelectrode for the generation of a large photocurrent. ATF photoelectrodes prepared by electrochemical anodization of freeze-cast Ti foams have three favorable characteristics: (i) large surface area for enhanced light harvesting, (ii) 1D semiconductor structure for facilitated charge collection, and (iii) 3D highly conductive metallic current collector that enables exclusion of transparent conducting oxide substrate. Based on these advantages, when ATF is utilized in dye-sensitized solar cells, short-circuit photocurrent density up to 22.0 mA cm-2 is achieved in the conventional N719 dye-I3- /I- redox electrolyte system even with an intrinsically inferior quasi-solid electrolyte.
ABSTRACT
Nanostructured metal oxide semiconductors have shown outstanding performances in photoelectrochemical (PEC) water splitting, but limitations in light harvesting and charge collection have necessitated further advances in photoelectrode design. Herein, we propose anodized Fe foams (AFFs) with multidimensional nano/micro-architectures as a highly efficient photoelectrode for PEC water splitting. Fe foams fabricated by freeze-casting and sintering were electrochemically anodized and directly used as photoanodes. We verified the superiority of our design concept by achieving an unprecedented photocurrent density in PEC water splitting over 5â mA cm-2 before the dark current onset, which originated from the large surface area and low electrical resistance of the AFFs. A photocurrent of over 6.8â mA cm-2 and an accordingly high incident photon-to-current efficiency of over 50 % at 400â nm were achieved with incorporation of Co oxygen evolution catalysts. In addition, research opportunities for further advances by structual and compositional modifications are discussed, which can resolve the low fill factoring behavior and improve the overall performance.
ABSTRACT
Semiconducting two-dimensional (2D) materials, particularly extremely thin molybdenum disulfide (MoS2) films, are attracting considerable attention from academia and industry owing to their distinctive optical and electrical properties. Here, we present the direct growth of a MoS2 monolayer with unprecedented spatial and structural uniformity across an entire 8 inch SiO2/Si wafer. The influences of growth pressure, ambient gases (Ar, H2), and S/Mo molar flow ratio on the MoS2 layered growth were explored by considering the domain size, nucleation sites, morphology, and impurity incorporation. Monolayer MoS2-based field effect transistors achieve an electron mobility of 0.47 cm2 V-1 s-1 and on/off current ratio of 5.4 × 104. This work demonstrates the potential for reliable wafer-scale production of 2D MoS2 for practical applications in next-generation electronic and optical devices.
ABSTRACT
A three-dimensional porous architecture makes an attractive electrode structure, as it has an intrinsic structural integrity and an ability to buffer stress in lithium-ion batteries caused by the large volume changes in high-capacity anode materials during cycling. Here we report the first demonstration of a SnO2-coated macroporous Cu foam anode by employing a facile and scalable combination of directional freeze-casting and sol-gel coating processes. The three-dimensional interconnected anode is composed of aligned microscale channels separated by SnO2-coated Cu walls and much finer micrometer pores, adding to surface area and providing space for volume expansion of SnO2 coating layer. With this anode, we achieve a high reversible capacity of 750 mAh g(-1) at current rate of 0.5 C after 50 cycles and an excellent rate capability of 590 mAh g(-1) at 2 C, which is close to the best performance of Sn-based nanoscale material so far.