CdSe nanostructured thin film by electrophoretic deposition for quantum dots sensitized solar cell.

Cadmium selenide (CdSe) quantum dots (QDs) with different size, 2.5 and 3.2 nm, were successfully deposited on mesoporous titanium dioxide (TiO2) (Degussa-P25) nanostructures by electrophoretic deposition method (EPD) at the applied voltage 100 V for 120 s deposition time. In this study, the morphology of CdSe films deposited by EPD and the performance of the film when assembled into a solar cell were investigated. From the field emission scanning electron microscopy cross-section, the thickness of the CdSe nanoparticles with size 2.5 nm films were 3.4 and 3.0µm for CdSe 3.2 nm nanoparticles film. The structure of 2.5 nm is denser than compare of 3.2 nm CdSe nanoparticles. From UV visible spectroscopy, the band gap calculated for 2.5 nm CdSe nanoparticles is 2.28 eV and for 3.2 nm is 2.12 eV. Photovoltaic characterization was performed under an illumination of 100 mW cm-2. A photovoltaic conversion efficiency of 1.81% was obtained for 2.5 nm CdSe and 2.1% was obtained for 3.2 nm CdSe nanoparticles. This result shows that the photovoltaic efficiency is dependent on CdSe nanoparticle size.

Content-based image retrieval for the diagnosis of myocardial perfusion imaging using a deep convolutional autoencoder.

BACKGROUND: Single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) plays a crucial role in the optimal treatment strategy for patients with coronary heart disease. We tested the feasibility of feature extraction from MPI using a deep convolutional autoencoder (CAE) model. METHODS: Eight hundred and forty-three pairs of stress and rest myocardial perfusion images were collected from consecutive patients who underwent cardiac scintigraphy in our hospital between December 2019 and February 2022. We trained a CAE model to reproduce the input paired image data, so as the encoder to output a 256-dimensional feature vector. The extracted feature vectors were further dimensionally reduced via principal component analysis (PCA) for data visualization. Content-based image retrieval (CBIR) was performed based on the cosine similarity of the feature vectors between the query and reference images. The agreement of the radiologist's finding between the query and retrieved MPI was evaluated using binary accuracy, precision, recall, and F1-score. RESULTS: A three-dimensional scatter plot with PCA revealed that feature vectors retained clinical information such as percent summed difference score, presence of ischemia, and the location of scar reported by radiologists. When CBIR was used as a similarity-based diagnostic tool, the binary accuracy was 81.0%. CONCLUSION: The results indicated the utility of unsupervised feature learning for CBIR in MPI.

Clinical significance of corrected relative flow reserve derived from 13N-ammonia positron emission tomography combined with coronary computed tomography angiography.

BACKGROUND: This study evaluated corrected relative flow reserve (RFR) derived from 13N-ammonia positron emission tomography (PET) combined with coronary computed tomography angiography (CTA). METHODS: We analyzed 61 patients who underwent coronary CTA, 13N-ammonia PET, and invasive coronary angiography. Triple-vessel disease were excluded. Conventional RFRs were calculated as the ratio of hyperemic myocardial blood flow (hMBF) of hypoperfusion areas to those of non-ischemic lesions. Corrected RFRs were calculated using PET and coronary CTA to adjust coronary territories to their feeding vessels. Diagnostic performance was compared to detect obstructive coronary lesions. RESULTS: Of the 180 vessels analyzed, 50 were diagnosed as obstructive lesions (≥ 70% stenosis and/or fractional flow reserve value ≤ 0.8). The coronary flow reserve (CFR), hMBF, conventional RFR, and corrected RFR of obstructive lesions were significantly lower than those of non-obstructive lesions. In receiver operating characteristic curve analysis, these quantitative PET measurements had area under the curve of 0.67, 0.71, 0.89, and 0.92, respectively. Diagnostic performance differences between corrected and conventional RFR were not statistically significant. CONCLUSION: In patients with single or double vessel disease, indices of RFR, with or without coronary angiographic guidance of the reference coronary territory, are better discriminators of flow-limiting stenoses than hMBF and CFR.

Image similarity-based cardiac rhythm device identification from X-rays using feature point matching.

AIMS: Identifying the manufacturer and the type of cardiac implantable electronic devices (CIEDs) is important in emergent clinical settings. Recent studies have illustrated that artificial neural network models can successfully recognize CIEDs from chest X-ray images. However, all existing methods require a vast amount of medical data to train the classification model. Here, we have proposed a novel method to retrieve an identical CIED image from an image database by employing the feature point matching algorithm. METHODS AND RESULTS: A total of 653 unique X-ray images from 456 patients who visited our pacemaker clinic between April 2012 and August 2020 were collected. The device images were manually square-shaped, and was thereafter resized to 224 × 224 pixels. A scale-invariant feature transform (SIFT) algorithm was used to extract the keypoints from the query image and reference images. Paired feature points were selected via brute-force matching, and the average Euclidean distance was calculated. The image with the shortest average distance was defined as the most similar image. The classification performance was indicated by accuracy, precision, recall, and F1-score for detecting the manufacturers and model groups, respectively. The average accuracy, precision, recall, and F-1 score for the manufacturer classification were 97.0%, 0.97, 0.96, and 0.96, respectively. For the model classification task, the average accuracy, precision, recall, and F-1 score were 93.2%, 0.94, 0.92, and 0.93, respectively, all of which were higher than those of the previously reported machine learning models. CONCLUSION: Feature point matching is useful for identifying CIEDs from X-ray images.

Influence of Ce3+ Substitution on Antimicrobial and Antibiofilm Properties of ZnCexFe2-xO4 Nanoparticles (X = 0.0, 0.02, 0.04, 0.06, and 0.08) Conjugated with Ebselen and Its Role Subsidised with γ-Radiation in Mitigating Human TNBC and Colorectal Adenocarcinoma Proliferation In Vitro.

Cancers are a major challenge to health worldwide. Spinel ferrites have attracted attention due to their broad theranostic applications. This study aimed at investigating the antimicrobial, antibiofilm, and anticancer activities of ebselen (Eb) and cerium-nanoparticles (Ce-NPs) in the form of ZnCexFe2-XO4 on human breast and colon cancer cell lines. Bioassays of the cytotoxic concentrations of Eb and ZnCexFe2-XO4, oxidative stress and inflammatory milieu, autophagy, apoptosis, related signalling effectors, the distribution of cells through the cell-cycle phases, and the percentage of cells with apoptosis were evaluated in cancer cell lines. Additionally, the antimicrobial and antibiofilm potential have been investigated against different pathogenic microbes. The ZOI, and MIC results indicated that ZnCexFe2-XO4; X = 0.06 specimen reduced the activity of a wide range of bacteria and unicellular fungi at low concentration including P. aeruginosa (9.5 mm; 6.250 µg/mL), S. aureus (13.2 mm; 0.390 µg/mL), and Candida albicans (13.5 mm; 0.195 µg/mL). Reaction mechanism determination indicated that after ZnCexFe2-xO4; X = 0.06 treatment, morphological differences in S.aureus were apparent with complete lysis of bacterial cells, a concomitant decrease in the viable number, and the growth of biofilm was inhibited. The combination of Eb with ZFO or ZnCexFe2-XO4 with γ-radiation exposure showed marked anti-proliferative efficacy in both cell lines, through modulating the oxidant/antioxidant machinery imbalance, restoring the fine-tuning of redox status, and promoting an anti-inflammatory milieu to prevent cancer progression, which may be a valuable therapeutic approach to cancer therapy and as a promising antimicrobial agent to reduce the pathogenic potential of the invading microbes.

Formation of grassy TiO2 nanotube thin film by anodisation in peroxide electrolyte for Cr(VI) removal under ultraviolet radiation.

Arrays of TiO2 nanotubes (TiO2 NTs) with grassy surfaces were observed on titanium foil anodised at 60 V in fluorinated ethylene glycol (EG) with added hydrogen peroxide (H2O2). The grassy surface was generated by the chemical etching and dissolution of the surface of the TiO2 NTs walls, which was accelerated by the temperature increase on the addition of H2O2 . Upon annealing at 600 °C, the grassy part of the TiO2 NTs was found to consist of mostly anatase TiO2 whereas the bottom part of the anodic oxide comprised a mixture of anatase and rutile TiO2. The TiO2 NTs were then used to reduce hexavalent chromium (Cr(VI)) under ultraviolet radiation. They exhibited a rather efficient photocatalytic effect, with 100% removal of Cr(VI) after 30 min of irradiation. The fast removal of Cr(VI) was due to the anatase dominance at the grassy part of the TiO2 NTs as well as the higher surface area the structure may have. This work provides a novel insight into the photocatalytic reduction of Cr(VI) on grassy anatase TiO2 NTs.

Sunlight activated anodic freestanding ZrO2 nanotube arrays for Cr(VI) photoreduction.

Visible-light-active freestanding zirconia (ZrO2) nanotube (FSZNT) arrays were fabricated by a facile electrochemical anodization method in fluoride containing ethylene glycol electrolyte added to it was 1 vol% of potassium carbonate (K2CO3) at 60 V for 1 h. Poor adhesion at the metal∣oxide interface was induced by K2CO3 leading to the formation of FSZNT flakes. The effect of the crystal structures of the FSZNTs e.g., amorphous, amorphous/tetragonal, and tetragonal/monoclinic was investigated towards the photocatalytic reduction of 10 ppm hexavalent chromium, Cr(VI) at pH 2 under sunlight. The results demonstrate the amorphous FSZNTs exhibited the highest Cr(VI) removal efficiency than the crystalline FSZNTs (95% versus 33% after 5 h). The high photocatalytic activity of the amorphous FSZNTs can be attributed to enhanced Cr(VI) adsorption, high visible light absorption, and better charge carrier separation. The low photocatalytic activity of the crystalline FSZNTs annealed at 500 °C was mainly attributed to poor Cr(VI) adsorption, low visible light absorption, and less photoactive monoclinic-ZrO2.

Clinical Usefulness of Coronary Flow Reserve Ratio for the Detection of Significant Coronary Artery Disease on 13N-Ammonia Positron Emission Tomography.

BACKGROUND: This study aimed to evaluate the diagnostic performance of coronary flow reserve (CFR), hyperemic myocardial blood flow (hMBF), and CFR ratio for detecting significant coronary artery disease (CAD) on 13N-ammonia positron emission tomography (PET).Methods and Results:We analyzed 63 patients (mean age, 71±9 years; 43 males) with suspected CAD who underwent both pharmacological stress/rest 13N-ammonia PET and coronary angiography. CFR and hMBF for PET were calculated automatically using quantitative PET software, and the CFR ratio was defined as the ratio of per-vessel CFR to maximum CFR in a standard 17-segment model. We compared the diagnostic performance among the 3 quantitative values. In the per-vessel analysis, 55 vessels were diagnosed as significant CAD (≥70% stenosis and/or fraction flow reserve ≤0.8). CFR, hMBF, and CFR ratio of significant CAD were significantly lower than for non-significant CAD (1.85±0.69 vs. 2.38±0.69; P<0.01, 1.67±0.54 vs. 2.19±0.52 mL·min-1·g-1; P<0.01, and 0.66±0.15 vs. 0.82±0.09; P<0.01, respectively). In the receiver-operating characteristic curve analysis, CFR, hMBF, and CFR ratio had areas under the curve of 0.71, 0.75, and 0.85 respectively, and the CFR ratio was significantly higher than CFR and hMBF (P<0.05). The sensitivity, specificity, and accuracy of the CFR ratio with an optimal cutoff value of 0.75 were 75%, 85%, and 82%, respectively. CONCLUSIONS: Clinically, the CFR ratio in 13N-ammonia PET was more effective in detecting significant CAD.

Favorable effects of early tolvaptan administration in very elderly patients after repeat hospitalizations for acute decompensated heart failure.

Tolvaptan (TLV) is an oral selective vasopressin 2 receptor antagonist that acts on the distal nephrons, causing a loss of electrolyte-free water. To date, its early administration in very elderly patients after repeat hospitalizations for acute decompensated heart failure (ADHF) despite receiving optimal medical therapy has not been evaluated. Fifty-six ADHF patients who were >80 years old and had been repeatedly hospitalized were retrospectively enrolled in this study. Twenty-five patients (14 men; mean age 86.7 ± 5.3 years; control group) received standard therapy and 31 patients (15 men; mean age 85.5 ± 4.5 years; TLV group) received oral TLV within 24 h of admission. The rate of worsening renal function was significantly lower in the TLV group than in the control group (13 vs. 40%, P < 0.05). The duration of the return to body weight at a steady state was significantly shorter in the TLV group (5.3 ± 2.8 days) than in the control group (13.9 ± 9.2 days, P < 0.01). Consequently, the hospitalization period in the TLV group (13.5 ± 5.9 days) was significantly shorter than that in the control group (24.7 ± 12.3 days, P < 0.01). In conclusion, the early administration of TLV to very elderly patients who underwent repeat hospitalizations for ADHF resulted in immediate decongestion and thus reduced the hospitalization period with a lower incidence of worsening renal function.

Beneficial effects of adaptive servo-ventilation therapy on readmission and medical costs in patients with chronic heart failure.

Adaptive servo-ventilation (ASV) therapy is a novel modality of noninvasive positive pressure ventilation and is now widely utilized to treat patients with chronic heart failure (CHF). However, there has been no clinical study of the effect of ASV therapy on readmission and cost-effectiveness for the treatment of CHF. The present study was conducted to evaluate the clinical efficacy and cost-effectiveness of home ASV therapy in 45 patients with a history of two or more admissions a year for worsening CHF. Seven patients refused to undergo chronic ASV therapy and three died. Thus, 35 patients were eventually enrolled in the present study. New York Heart Association class (2.8 ± 0.4 versus 2.3 ± 0.5, p < 0.001), log plasma B-type natriuretic peptide level (2.53 ± 0.44 versus 2.29 ± 0.40 pg/mL, p < 0.0001), left atrial dimension (47.5 ± 7.0 versus 44.9 ± 7.6 mm, p = 0.014), and mitral regurgitation area ratio (20.3 ± 12.1 versus 16.9 ± 8.9%, p = 0.007) decreased significantly after 12 months of ASV therapy. The frequency of hospitalization after ASV was significantly lower than before ASV (1.0 ± 1.0 versus 2.3 ± 0.5 times/year/patient, p < 0.0001). ASV also decreased the duration of hospitalization from 64.4 ± 46.5 to 22.8 ± 27.5 days/year/patient (p < 0.0001). Consequently, the total medical costs were reduced by 37% after ASV (1.95 ± 1.37 versus 3.11 ± 1.75 million yen/patient, p = 0.003). ASV therapy reduced readmissions and medical costs in patients with CHF.

Multiferroic nanocomposite fabrication via liquid phase using anodic alumina template.

We report a novel and inexpensive fabrication process of multiferroic nanocomposite via liquid phase using an anodic alumina template. The sol-gel spin-coating technique was used to coat the template with ferrimagnetic CoFe2O4. By dissolving the template with NaOH aqueous solution, a unique nanotube array structure of CoFe2O4 was obtained. The CoFe2O4 nanotube arrays were filled with, and sandwiched in, ferroelectric BaTiO3 layers by a sol-gel spin-coating method to obtain the composite. Its multiferroicity was confirmed by measuring the magnetic and dielectric hysteresis loops.

Ag nanoparticle-filled TiO2 nanotube arrays prepared by anodization and electrophoretic deposition for dye-sensitized solar cells.

A layer of TiO2 nanotube (TNT) arrays with a thickness of 13 µm is synthesized by a two-step anodic oxidation from Ti metal foil. Surface charged Ag nanoparticles (NPs) are prepared by chemical reduction. After a pretreatment of the TNT arrays by acetone vapor, Ag NP filled TNT arrays can be achieved by electrophoretic deposition (EPD). Effects of the applied voltage during EPD such as DC-AC difference, frequency and waveform are investigated by quantitative analysis using atomic absorption spectroscopy. The results show that the best EPD condition is using DC 2 V + AC 4 V and a square wave of 1 Hz as the applied voltage. Back illuminated dye-sensitized solar cells are fabricated from TNT arrays with and without Ag NPs. The efficiency increased from 3.70% to 5.01% by the deposition of Ag NPs.

Photocatalytic performance of freestanding tetragonal zirconia nanotubes formed in H2O2/NH4F/ethylene glycol electrolyte by anodisation of zirconium.

ZrO2 nanotubes (ZrNTs) were produced by anodisation of zirconium foil in H2O2/NH4F/ethylene glycol electrolyte. The as-anodised foils were then soaked in the anodising electrolyte for 12 h. Soaking weakens the adherence of the anodic layer from the substrate resulting in freestanding ZrNTs (FS-ZrNTs). Moreover, the presence of H2O2 in the electrolyte also aids in weakening the adhesion of the film from the foil, as foil anodised in electrolyte without H2O2 has good film adherence. The as-anodised FS-ZrNTs film was amorphous and crystallised to predominantly tetragonal phase upon annealing at >300 °C. Annealing must, however, be done at <500 °C to avoid monoclinic ZrO2 formation and nanotubes disintegration. FS-ZrNTs annealed at 450 °C exhibited the highest photocatalytic ability to degrade methyl orange (MO), whereby 82% MO degradation was observed after 5 h, whereas FS-ZrNTs with a mixture of monoclinic and tetragonal degraded 70% of MO after 5 h.

Anodic Ag/TiO2 nanotube array formation in NaOH/fluoride/ethylene glycol electrolyte as a photoanode for dye-sensitized solar cells.

Self-organized, 23 µm-thick anodic TiO2 nanotube (TNT) arrays were formed in sodium hydroxide/fluoride/ethylene glycol (EG) electrolyte at 60 V for 60 min. The presence of sodium hydroxide (NaOH) in the fluoride/EG electrolyte accelerates the formation of the TiO2 nanotube arrays. The anodic film was then decorated with silver nanoparticles (Ag NPs) by the photodeposition process and used as a photoanode in a rear-side-illuminated dye-sensitized solar cell. The Ag NPs decorated TNT arrays, with the former having diameters of 10-30 nm formed from 0.2 M of Ag-precursor solution and exhibiting the highest photoconversion efficiency (η) of 3.7% and a short-circuit current density of 12.2 mA cm(-2) compared to η = 3% and short-circuit current density of 9.1 mA cm(-2) for a sample without Ag NPs. The increase in η is thought to be due to the surface plasmon resonance and excess electrons from the nanoparticles.

Visible-light-induced photocatalysis of 2D-hexagonal mesoporous SiO2-TiO2 deposited with Au nanoparticles.

Au nanoparticles (NPs) are deposited using a couple of methods onto a sol-gel-derived mesoporous SiO2-TiO2 template. A modification of the template with 3-aminopropyltriethoxysilane (APTES) before the deposition of Au leads to the formation of Au nanorods instead of Au nanospheres in the tubular mesopores. The modification also causes a deterioration of visible-light-induced photocatalytic activity. Heat treatment of this sample to remove APTES results in an amelioration of the photocatalytic activity. The detailed mechanism of the deterioration and amelioration of the activity is discussed on the accessibility of the reactant to the sample and the easiness of the charge carrier transfer between TiO2 and Au NPs.

Formation of two-dimensional ZnO nanosheets by rapid thermal oxidation in oxygenated environment.

Crystalline 2-D (dimensional) ZnO nanosheets were formed by rapid thermal oxidation of etched Zn foil in oxygen at 300 degrees C and 400 degrees C. Short oxidation time was varied from 10, 20 and 30 min. The morphologies and optical properties of the ZnO nanosheets evolved with the oxidation temperature and time. At 300 degrees C, ZnO nanosheets with thickness ranging from 32 nm to 80 nm were obtained while at 400 degrees C, the thickness of the nanosheets increased from 88 nm to approximately 200 nm after 10 and 30 min of oxidation, respectively. The surface roughness of the ZnO nanosheets and grain size increased with oxidation time and temperature. Photoluminescence of the oxidized samples shows ultraviolet (UV) and visible emissions indicating good crystallinity of ZnO which was further confirmed by high-resolution transmission electron microscope observation of ZnO wurtzite interplanar spacing. Photocatalytic activity of ZnO was also investigated by using degradation of methyl orange (MO) and all the samples exhibit photocatalytic activity. The sample oxidized at 400 degrees C for 10 min show better MO degradation after 2 h of exposure due to higher surface area and better crystallinity of the ZnO nanosheets obtained.

Enhanced Photoelectrochemical Property of TiO2 Nanotube Array Photoanode Deposited with Al,Cr-Codoped SrTiO3 Nanocubes.

There is a demand for the effective utilization of solar energy with highly functional photoelectrodes for photoelectrochemical (PEC) applications, such as water splitting and CO2 reduction. TiO2 nanotube arrays (TNTA) with a large surface area have been studied as potential photoelectrodes mainly due to their strong oxidation potential. However, it has disadvantages of fast charge recombination and little responsivity to visible light. In this study, we prepared TNTA by anodizing a Ti plate and decorated the TNTA with Al,Cr-codoped SrTiO3 (STO) nanocubes through a hydrothermal treatment to enhance the PEC properties. We also prepared pristine and undoped STO-decorated TNTA for comparison. The hydrothermal treatment duration was optimized for the TNTA-STO:Al,Cr sample to achieve the best PEC performance. Finally, the possible PEC reaction mechanism was proposed based on the obtained experimental results.

Bottom-up synthesis of ion-pair-bridged metal-organic framework for H+ conduction.

As a novel conceptual synthesis of a metal-organic framework (MOF)-based proton conductor, UiO-66 based on a pyridinedicarboxylic acid phosphate (PyDC-PA) ion pair linker has been developed, in which the phosphoric acid is fixed to the N donor moiety of pyridine via an ionic bond.

Tube length optimization of titania nanotube array for efficient photoelectrochemical water splitting.

Anodic TiO2 nanotube arrays (TNTAs) have attracted much attention due to their excellent photoelectrochemical (PEC) properties. In this work, the tube length of TNTAs was optimized for efficient PEC water splitting under two different conditions, in which very few or a massive amount of gas bubbles were generated on the electrodes. As a result, relatively longer TNTAs were found to be preferable for higher PEC performance when a larger number of bubbles were generated. This suggests that the mass transport in the electrolyte is assisted by the generated bubbles, so that the electrode surfaces are more easily exposed to the fresh electrolyte, leading to the higher PEC performance.