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Manganese-Enhanced MRI for Preclinical Evaluation of Retinal Degeneration Treatments
摘要： PURPOSE. Apply manganese-enhanced magnetic resonance imaging (MEMRI) to assess ion channel activity and structure of retinas from mice subject to light-induced retinal degeneration treated with prophylactic agents. METHODS. Abca4?/?Rdh8?/? double knockout mice with and without prophylactic retinylamine (Ret-NH2) treatment were illuminated with strong light. Manganese-enhanced MRI was used to image the retina 2 hours after intravitreous injection of MnCl2 into one eye. Contrast-enhanced MRIs of the retina and vitreous humor in each experimental group were assessed and correlated with the treatment. Findings were compared with standard structural and functional assessments of the retina by optical coherence tomography (OCT), histology, and electroretinography (ERG). RESULTS. Manganese-enhanced MRI contrast in the retina was high in nonilluminated and illuminated Ret-NH2–treated mice, whereas no enhancement was evident in the retina of the light-illuminated mice without Ret-NH2 treatment (P < 0.0005). A relatively high signal enhancement was also observed in the vitreous humor of mice treated with Ret-NH2. Strong MEMRI signal enhancement in the retinas of mice treated with retinylamine was correlated with their structural integrity and function evidenced by OCT, histology, and a strong ERG light response. CONCLUSIONS. Manganese-enhanced MRI has the potential to assess the response of the retina to prophylactic treatment based on the measurement of ion channel activity. This approach could be used as a complementary tool in preclinical development of new prophylactic therapies for retinopathies.
关键词： manganese-enhanced MRI,efficacy evaluation,retinal degeneration,retinylamine
更新于2025-09-23 15:22:29
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Determining the efficacy of corneal crosslinking in progressive keratoconus
摘要： Objective: To determine the Efficacy of Corneal Crosslinkage (CXL), using Corneal Topography, in eyes with progressive Keratoconus. Methods: This randomized control trial was conducted at Armed Forces Institute of Ophthalmology, Rawalpindi, Pakistan from October 2013 to April 2014. A total of 60 eyes of 30 patients were included who presented with bilateral progressive Keratoconus. Each eye of the patient was randomized either to a treatment group (Group-A) or control untreated group (GroupB) of 30 eyes each. A written informed consent was obtained from each patient, following which corneal crosslinkage (CXL) with topical riboflavin eye drops was performed. Follow up visit was done at three months post operatively, Corneal topography was repeated and recorded. Results: The mean age of the patients was 23.13±7.62 years (range 13 to 39 years). There were 26 males and 34 females patients. The mean simK value at the start of study was 50.94±4.84 diopters in Group-A and 49.73±5.24 diopters in Group-B. At three months follow-up, the mean simK value was significantly lower in Group-A (48.28±4.47) as compared to Group-B (51.11±4.85). Keratoconus improved/ remained stable in 34 (56.7%) eyes while progressive disease was noted in 26 (43.3%) eyes. When compared between the groups, the frequency of efficacy was significantly higher in Group-A (86.7% vs. 26.7%; p=.000) as compared to Group-B. Conclusion: Corneal Crosslinking was found effective in causing regression or halting the progression of disease in patients with progressive Keratoconus at three months follow-up , however, the efficacy of corneal crosslinking was unaffected by patient’s age and gender.
关键词： Corneal Crosslinking,Efficacy,Keratoconus
更新于2025-09-23 15:22:29
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Perioperative Safety and Efficacy of Holmium Laser Enucleation of the Prostate in Patients Receiving Antithrombotic Therapy: A Prospective Cohort Study
摘要： We investigated the efficacy of and risk from holmium laser enucleation of the prostate (HoLEP) due to discontinuation of antithrombotics in patients with benign prostatic hyperplasia (BPH). Patients in the prospective SNUH-BPH Database Registry who underwent HoLEP between December 2010 and December 2017 were enrolled. Preoperative evaluation included symptom score questionnaires, laboratory tests, urine tests, prostate-specific antigens, urodynamic study, and transrectal ultrasonography. Postoperative evaluation was performed at 2 weeks, 3 months, and 6 months. Information regarding the types of antithrombotics and their use, underlying disease, and antithrombotic management during surgery was collected. The study included 55 patients. The mean age and preoperative prostate volume were 68.7 ± 6.4 years and 70.3 ± 32.2 mL, respectively. The mean preoperative hemoglobin level was 13.5 ± 2.6 g/dL in the patients receiving antithrombotics. Of the patients, 71% were taking aspirin. Seventy-five (66.5%) and 70 patients (28.2%) discontinued the antithrombotic therapy 5–7 days and <1 week preoperatively, respectively. Three patients (1.21%) were switched to low-molecular-weight heparin therapy, and 10 (4.03%) continued antithrombotic therapy. No significant differences were found in the incidence rates of postoperative transfusion (p = 0.894) or complications from antithrombotic use, thrombosis (p = 0.946), haemorrhage requiring bladder irrigation (p = 0.959), transurethral coagulation (p = 0.894), cardiovascular events (p = 0.845), and cerebrovascular events (p = 0.848). Efficacy and complications related to the short-term antithrombotic withdrawal before and after HoLEP also showed no significant differences. HoLEP may be a beneficial surgical technique for patients with BPH who are receiving antithrombotics.
关键词： Benign Prostatic Hyperplasia,Perioperative Safety,Antithrombotic Therapy,Holmium Laser Enucleation of the Prostate,Efficacy
更新于2025-09-23 15:21:01
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New Unsymmetrical Bisacridine Derivatives Noncovalently Attached to Quaternary Quantum Dots Improve Cancer Therapy by Enhancing Cytotoxicity toward Cancer Cells and Protecting Normal Cells
摘要： The use of nanoparticles for the controlled drug delivery to cells has emerged as a good alternative to traditional systemic delivery. Quantum dots (QDs) offer potentially invaluable societal benefits such as drug targeting and in vivo biomedical imaging. In contrast, QDs may also pose risks to human health and the environment under certain conditions. Here, we demonstrated that a unique combination of nanocrystals core components (Ag-In-Zn-S) would eliminate the toxicity problem and increase their biomedical applications. The alloyed quaternary nanocrystals Ag-In-Zn-S (QDgreen, Ag1.0In1.2Zn5.6S9.4; QDred, Ag1.0In1.0Zn1.0S3.5) were used to transport new unsymmetrical bisacridine derivatives (UAs, C-2028 and C-2045) into lung H460 and colon HCT116 cancer cells for improving the cytotoxic and antitumor action of these compounds. UAs were coupled with QD through physical adsorption. The obtained results clearly indicate that the synthesized nanoconjugates exhibited higher cytotoxic activity than unbound compounds, especially toward lung H460 cancer cells. Importantly, unsymmetrical bisacridines noncovalently attached to QD strongly protect normal cells from the drug action. It is worth pointing out that QDgreen or QDred without UAs did not influence the growth of cancer and normal cells, which is consistent with in vivo results. In noncellular systems, at pH 5.5 and 4.0, which relates to the conditions of endosomes and lysosomes, the UAs were released from QD-UAs nanoconjugates. An increase of total lysosomes content was observed in H460 cells treated with QDs-UAs which can affect the release of the UAs from the conjugates. Moreover, confocal laser scanning microscopy analyses revealed that QD-UAs nanoconjugates enter H460 cells more efficiently than to HCT116 and normal cells, which may be the reason for their higher cytotoxicity against lung cancer. Summarizing, the noncovalent attachment of UAs to QDs increases the therapeutic efficiency of UAs by improving cytotoxicity toward lung H460 cancer cells and having protecting effects on normal cells.
关键词： lung and colon cancer cells,unsymmetrical bisacridine derivatives,drug-carrier degradation pathway,pH-dependent release,cellular uptake,in vivo antitumor efficacy,Ag-In-Zn-S nanocrystals,cytotoxic activity
更新于2025-09-23 15:21:01
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Measurement setup for differential spectral responsivity of solar cells
摘要： We have developed a setup for measuring differential spectral responsivities of unifacial and bifacial solar cells under bias light conditions. The setup uses 30 high-brightness LEDs for generating a quasi-monochromatic light source covering the wavelength range 290–1300 nm. Halogen lamps are used to generate bias-lighting conditions up to the irradiance level of 1000 W/m2. The setup has been fully characterized for spectral irradiances and spatial uniformities of all light sources. Validation measurements carried out using a reference cell of 2 × 2 cm2 area from Fraunhofer ISE demonstrated an agreement better than 2% over the wavelength range of 425–940 nm, with an expanded uncertainty of 2.6%. In the UV and IR regions, the discrepancies are higher but still within estimated uncertainties. The setup is also tested in measuring spectral responsivities of large 15 × 15 cm2 bifacial solar cells. The associated problems are discussed.
关键词： Radiometry,Bifacial,Solar cell,Spectral responsivity,Electricity,Efficacy
更新于2025-09-23 15:21:01
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Al2O3-Ce:GdYAG composite ceramic phosphors for high-power white light-emitting-diode applications
摘要： In order to meet the increasing demand of high-power light-emitting-diode (LED) lighting, state-of-the-art white light-emitting diode technology needs phosphors with high thermal conductivity and high luminous efficacy as color converters. In this work, translucent Al2O3-Ce:GdYAG composite phosphors were prepared by solid-state reactive sintering. The microstructure shows that the Al2O3 particles are uniformly dispersed in the Ce:GdYAG matrix. These particles can not only improve the thermal conductivity of the ceramics, but also promote the extraction efficacy. The luminous characteristics of the Ce:GdYAG and Al2O3-Ce:GdYAG ceramics were analyzed after being packaged with blue LED. When the molar ratio of Al2O3/Ce:GdYAG is 0.8, a high luminous efficacy value of 112.6 lm/W is achieved by the Al2O3-Ce:GdYAG composite ceramic phosphor with the thickness of 0.4 mm, as well as the highest CRI valve of 71.4. The appropriate photoelectric properties of this kind of ceramic phosphor make it a promising candidate for high-power LED device.
关键词： luminous efficacy,white-LED,color coordinates,composite ceramic phosphors,Al2O3-Ce:GdYAG
更新于2025-09-19 17:15:36
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From physics to fixtures to food: current and potential LED efficacy
摘要： Light-emitting diodes (LEDs) have enabled a historic increase in the conversion of electric energy to photons, but this is approaching a physical limit. The theoretical maximum efficiency occurs when all input energy is converted to energy in photosynthetic photons. Blue LEDs can be 93% efficient, phosphor-converted “whites” 76% efficient, and red LEDs 81% efficient. These improvements open new opportunities for horticultural lighting. Here we review (1) fundamental physics and efficiency of LEDs, (2) the current efficacy of LEDs, (3) the effect of spectral quality on crop yield, and (4) the potential efficacy of horticultural fixtures. Advances in the conversion of photons to yield can be achieved by optimization of spectral effects on plant morphology, which vary among species. Conversely, spectral effects on photosynthesis are remarkably similar across species, but the photons conventional (400–700 nm) may need to be modified. The upper limit of LED fixture efficacy is determined by the LED package efficacy multiplied by four factors inherent to all fixtures: thermal droop, driver (power supply) current droop, inefficiencies, and optical losses. With current LED technology, the calculations indicate efficacy limits of 3.4 μmol J?1 for white + red fixtures, and 4.1 μmol J?1 for blue + red fixtures. Adding optical protection from water and high humidity reduces these values by ~10%. We describe tradeoffs between peak efficacy and cost.
关键词： spectral quality,fixture efficacy,horticultural lighting,LEDs,photosynthetic photons
更新于2025-09-19 17:13:59
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Optimization of a spectrally tunable daylight simulator using four quantum dot light‐emitting diodes for visual appraisal of color
摘要： An optimization model for luminous efficacy of a spectrally tunable light-emitting diode (LED) daylight simulator under constraint of metamerism index was developed. It was first reported that the optimal spectrally tunable LED daylight simulator of AA grade for D50, D55, D65, and D75 standard illuminants could consist of two quantum dot-integrated LEDs (QDLEDs) with the ultraviolet chip and two other QDLEDs with the blue chip. The optimized spectral parameters of each QDLED, as well as photometric and colorimetric performances of D50, D55, D65, and D75 daylight simulators, were obtained by maximizing luminous efficacy under the metamerism index for both a visible and ultraviolet range less than 0.25. The limit luminous efficacies of four daylight simulators using four QDLEDs under the ideal case will reach 181 lm/W to 205 lm/luminous efficacies with a radiant efficiency of both the ultraviolet and blue chips of 60%, as well as a quantum efficiency of a quantum dots layer of 90%, will reach 100 lm/W to 112 lm/W.
关键词： daylight simulator,metamerism index,optimization,luminous efficacy,quantum dot LED
更新于2025-09-19 17:13:59
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A retrospective analysis for facial telangiectasia treatment using pulsed dye laser and intense pulsed light configured with different wavelength bands
摘要： Background: Facial telangiectasia is one of the common skin vascular lesions characterized by dilated cutaneous vasculatures. The variety of diameters and difference in depths of lesional blood vessels are the major challenges for effective treatments for Facial telangiectasia. Aims: To compare the efficacy and safety profiles of pulsed dye laser (PDL, 595 nm) with intense pulsed light (IPL) configured by three different wavelength bands in the treatment for facial telangiectasia in Asian populations. Patients/Methods: A retrospective analysis of hospital records and review on photographs were performed for those subjects with facial telangiectasia (n = 160) who were treated in our department from January 2017 to January 2019. Patients were received two sessions of one of the four following laser treatments: PDL (595 nm, n = 38), IPL with M22 vascular filter (530‐650 nm and 900‐1200 nm, n = 39), M22 560 (560‐1200 nm, n = 42), and M22 590 (590‐1200 nm, n = 41). Results: The patients in all the four groups showed an overall and significant improvement of indexes of lesional severity and subjective discomfort as well as improvement score of facial telangiectasia after treatment as compared to baseline. In addition, PDL (595 nm) and IPL with vascular filter (530‐650 nm and 900‐1200 nm) treatments showed significantly better indexes of lesional severity, subjective discomfort, and improvement score of facial telangiectasia as compared with other two treatments. Conclusion: Light devices with various wavelength ranges showed different efficacies of treatment for facial telangiectasia, among which PDL (595 nm) and IPL with M22 vascular filter (530‐650 nm and 900‐1200 nm) had similar and the best clinical efficacy as compared to IPL with other wavelength bands.
关键词： pulsed dye laser,intense pulse light,facial telangiectasia,efficacy,retrospective analysis
更新于2025-09-19 17:13:59
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A poly(urethane)-encapsulated benzo[2,3- <i>d</i> :6,7- <i>d</i> a?2]diimidazole organic down-converter for green hybrid LEDs
摘要： The development of organic down-converting materials continues to attract attention in hybrid LED technology by obviating the need for non-sustainable rare-earth elements. In this work, a benzodiimidazole-based system (TPA-BDI) has been employed as a down-converting layer in a hybrid organic–inorganic LED device. A commercially available poly(urethane)-based resin is used as the encapsulating material, providing a dilute layer of TPA-BDI that is deposited on top of the GaN-based LED. Crucially, the solution-state emissive performance is generally maintained when encapsulated at low concentrations within this resin. A maximum luminous efficacy of 87 lm W?1 was demonstrated using a 1.0 mg ml?1 concentration of TPA-BDI in the resin. The suitability of using organic down-converters to produce green light from hybrid devices was demonstrated by the excellent repeatability of the device characteristics across a series of encapsulated LEDs.
关键词： poly(urethane)-based resin,hybrid LED technology,luminous efficacy,benzodiimidazole-based system,GaN-based LED,organic down-converting materials
更新于2025-09-19 17:13:59