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991.
Shakeel Ahmed Wang Rui Faizah Altaf Jahanzeb Khan Patrizia Bocchetta Han Zhang 《Materials》2022,15(15)
Two-dimensional (2D) tri-TMDCs carrier dynamics provide a platform for studying excitons through Ultrafast Pump-Probe Transient Absorption Spectroscopy. Here we studied the ZrTe3 nanosheets (NTs) exciton dynamics by transient absorption (TA) spectrometer. We observed different carrier dynamics in the ZrTe3 NTs sample at different pump powers and with many wavelengths in the transient absorption spectrometer. The shorter life decay constant is associated with electron-phonon relaxation. Similarly, the longer-life decay constant represents the long live process that is associated with charge separation. The interactions between carrier-phonons at nanoscale materials can be changed by phonons quantum confinements. The hot carrier lifetime determined the strength of carrier phonon interactions. The value of fast decay in the conduction band is due to carrier relaxation or the carrier gets trapped due to surface states or localized defects. The value of slow decay is due to the recombination of surface state and localized defects processes. The lifetime declines for long wavelengths as size decreases. Whereas, during short wavelength-independent decay, carrier characteristics have been observed. TA spectroscopy is employed to investigate insight information of the carrier’s dynamical processes such as carrier lifetime, cooling dynamics, carrier diffusion, and carrier excitations. The absorption enhanced along excitons density with the increase of pump power, which caused a greater number of carriers in the excited state than in the ground state. The TA signals consist of trap carriers and (electron-hole) constituents, which can be increased by TA changes that rely on photoexcitation and carrier properties. 相似文献
992.
Fouad Damiri Swetha Andra Nagavendra Kommineni Satheesh Kumar Balu Raviteja Bulusu Amira A. Boseila Damilola O. Akamo Zubair Ahmad Farhat S. Khan Md. Habibur Rahman Mohammed Berrada Simona Cavalu 《Materials》2022,15(15)
Water contamination is one of the most urgent concerns confronting the world today. Heavy metal poisoning of aquatic systems has piqued the interest of various researchers due to the high toxicity and carcinogenic consequences it has on living organisms. Due to their exceptional attributes such as strong reactivity, huge surface area, and outstanding mechanical properties, nanomaterials are being produced and employed in water treatment. In this review, recent advances in the use of nanomaterials in nanoadsorptive membrane systems for wastewater treatment and heavy metal removal are extensively discussed. These materials include carbon-based nanostructures, metal nanoparticles, metal oxide nanoparticles, nanocomposites, and layered double hydroxide-based compounds. Furthermore, the relevant properties of the nanostructures and the implications on their performance for water treatment and contamination removal are highlighted. The hydrophilicity, pore size, skin thickness, porosity, and surface roughness of these nanostructures can help the water permeability of the nanoadsorptive membrane. Other properties such as surface charge modification and mechanical strength can improve the metal adsorption effectiveness of nanoadsorptive membranes during wastewater treatment. Various nanocomposite membrane fabrication techniques are also reviewed. This study is important because it gives important information on the roles of nanomaterials and nanostructures in heavy metal removal and wastewater treatment. 相似文献
993.
Arsalan Raza Imran Khan Rana Faisal Tufail Jana Frankovska Muhammad Umar Mushtaq Abdellatif Salmi Youssef Ahmed Awad Muhammad Faisal Javed 《Materials》2022,15(15)
To enhance the moisture damage performance of hot mix asphalt (HMA), treating the aggregate surface with a suitable additive was a more convenient approach. In this research, two types of aggregate modifiers were used to study the effect of moisture damage on HMA. Three different aggregate sources were selected based on their abundance of use in HMA. To study the impact of these aggregate modifiers on moisture susceptibility of HMA, the indirect tensile strength test and indirect tensile modulus test were used as the performance tests. Moisture conditioning of specimens was carried out to simulate the effect of moisture on HMA. The prepared samples’ tensile strength ratio (TSR) and stiffness modulus (Sm) results indicated a decrease in the strength of the HMA after moisture conditioning. After treating the aggregate surface with additives, an improvement was seen in dry and wet strength and stiffness. Moreover, an increasing trend was observed for both additives. The correlation between TSR and strength loss reveals a strong correlation (R2 = 0.7219). Also, the two additives indicate increased wettability of asphalt binder over aggregate, thus improving the adhesion between aggregate and asphalt binder. 相似文献
994.
Hammad Ahmed Shah Moncef L. Nehdi Muhammad Imtiaz Khan Usman Akmal Hisham Alabduljabbar Abdullah Mohamed Muhammad Sheraz 《Materials》2022,15(15)
Compressive strength (CS) and splitting tensile strength (STS) are paramount parameters in the design of reinforced concrete structures and are required by pertinent standard provisions. Robust prediction models for these properties can save time and cost by reducing the number of laboratory trial batches and experiments needed to generate suitable design data. Silica fume (SF) is often used in concrete owing to its substantial enhancements of the engineering properties of concrete and its environmental benefits. In the present study, the M5P model tree algorithm was used to develop models for the prediction of the CS and STS of concrete incorporating SF. Accordingly, large databases comprising 796 data points for CS and 156 data records for STS were compiled from peer-reviewed published literature. The predictions of the M5P models were compared with linear regression analysis and gene expression programming. Different statistical metrics, including the coefficient of determination, correlation coefficient, root mean squared error, mean absolute error, relative squared error, and discrepancy ratio, were deployed to appraise the performance of the developed models. Moreover, parametric analysis was carried out to investigate the influence of different input parameters, such as the SF content, water-to-binder ratio, and age of the specimen, on the CS and STS. The trained models offer a rapid and accurate tool that can assist the designer in the effective proportioning of silica fume concrete. 相似文献
995.
Sequential effects of cadmium on genotoxicity and lipoperoxidation in <Emphasis Type="Italic">Vicia faba</Emphasis> roots 总被引:1,自引:0,他引:1
Kinetics of stress responses to Cd exposure (50, 100 and 200 μM) expanding from 12 to 48 h were studied in roots of hydroponically
cultivated-Vicia faba seedlings. The heavy metal induced toxicity symptoms and growth arrest of Vicia roots gradually to the Cd concentration and duration of the treatment. The intracellular oxidative stress was evaluated with
the H2O2 production. The H2O2 content increased gradually with the sequestered Cd and root growth inhibition. Lipid peroxidation—evidenced by malondialdehyde
(MDA) content and Evans blue uptake—and genotoxicity—evidenced by mitotic index (MI) and micronuclei (MCN) values—were concomitantly
investigated in root tips. By 12 h, root meristematic cells lost 15% of their mitotic activity under 50 or 100 μM Cd treatment
and 50% under 200 μM Cd treatment and led cells with MCN, while the MDA content and Evans blue absorption were not affected.
The loss of membrane integrity occurred subsequently by 24 h. The increase in MDA content in root cells treated with 50, 100
and 200 μM Cd was significantly higher than the control. By 48 h, the MDA content increased 134, 178 or 208% in root cells
treated with 50, 100 and 200 μM Cd, respectively. The Evans blue absorption was also affected by 24 h in roots when treated
with 200 μM Cd and gradually increase by 48 h with the Cd concentration of the treatment. The decrease of mitotic activity
triggered by 12 h was even higher by 24 h and the MI reduced to 44, 56 or 80% compared to the control in the three different
Cd concentrations tested. The different kinetics of early in vivo physiological and cytogenetic responses to Cd might be relevant
to the characterization of its toxicity mechanisms in disrupting primarily the mitosis process. 相似文献
996.
PURPOSE: To compare higher order wavefront aberrations in eyes implanted with acrylic aspherical intraocular lenses (IOLs) with a modified prolate anterior surface with conventional acrylic spherical IOLs by using the optical path difference method. METHODS: In a nonrandomized parallel cohort investigation, 36 eyes of 31 patients implanted with aspherical IOLs (Tecnis ZA9003) and 37 eyes of 23 age-matched patients implanted with spherical IOLs (SENSOR AR40e) were evaluated with a wavefront analyzer (OPD-Scan II) preoperatively and 1 month after surgery. The higher order aberrations for a 4.0-mm pupil diameter were expanded into Zernike's polynomial expression. Coma aberration, spherical aberration, and total higher order aberrations were evaluated as root mean square values. RESULTS: Postoperatively, coma and total higher order aberrations of spherical and aspherical IOLs significantly improved in both eyes. Spherical aberration improved in eyes with aspherical IOLs only (P < 0.01). CONCLUSION: After implantation of acrylic aspherical IOLs, postoperative higher order aberrations were not necessarily lower than after implantation of acrylic spherical IOLs, but compared with levels following implantation of acrylic spherical IOLs, a significant reduction in spherical aberration was achieved. 相似文献
997.
Shimada H Yuzawa M Hirose T Nakashizuka H Hattori T Kazato Y 《Japanese journal of ophthalmology》2008,52(4):282-288
PURPOSE: To compare the pathological findings between multifocal choroiditis with panuveitis (MCP) and punctate inner choroidopathy (PIC). METHODS: Fourteen eyes of 14 patients clinically diagnosed as having MCP or PIC who underwent surgical excision of choroidal neovascularization (CNV) were studied. Immunohistochemical findings of the excised CNV in MCP (eight eyes) and PIC (six eyes) cases were compared. Antibodies against vascular endothelial growth factor (VEGF), CD68, CD3, and CD20 were used as primary antibodies. RESULTS: Expression of VEGF and CD68 in the CNV was observed in all MCF and PIC cases. In three of eight eyes with MCP, intraocular inflammatory findings were found clinically, while immunohistochemical study demonstrated infiltration of CD20-positive B lymphocytes in the CNV. No B lymphocyte infiltration was found in the six eyes with PIC. No differences in pathological findings were found between the five MCP eyes without intraocular inflammation and the six PIC eyes, with all eyes showing no B lymphocyte infiltration. CONCLUSIONS: In MPC cases showing clinical inflammatory findings, infiltration of B lymphocytes was also observed histopathologically, suggesting that the presence of inflammatory cells in the anterior chamber or vitreous body clinically is an indicator of active inflammatory CNV. However, this study clarifies that MCP eyes without intraocular inflammation and PIC eyes are not different in histopathological findings. 相似文献
998.
Monika Maria Biernat Jolanta Rusiecka-Ziółkowska Elżbieta Piątkowska Iwona Helemejko Paweł Biernat Grażyna Gościniak 《Japanese journal of ophthalmology》2018,62(6):628-633
Purpose
Two Demodex species (eyelash mites)—D. folliculorum and D brevis—are believed to be associated with human skin and eye diseases. However, the clinical significance of infection with Demodex species remains controversial.Study design
The aim of this study was to estimate the prevalence of ocular demodicosis in patients with blepharitis as compared with the prevalence in the healthy population in Poland.Methods
This case-control prospective study was carried out from 2007 to 2016. The enrolled patients (668) were divided into 2 groups: the study group, comprising 553 patients with blepharitis (349 women and 204 men, aged 17–88 years), and the control group, comprising 115 healthy volunteers without a history of ocular pathologies (78 women and 37 men, aged 17–88 years). A sample of 10 eyelashes was taken aseptically from each eye of the examined person and later studied under a light microscope.Results
Demodex species were found in 62.4% (345/544) of the patients in the study group and in 24.3% (28/100) of the controls (P = .001, OR = 0.006). The overall prevalence was 55.8% (373/668) in all the examined participants. The presence of Demodex infection increased with age in both groups. No association of Demodex infection with gender was found (119/204 vs 226/349; P > .05, OR 1.086). A high mean number of mites was present more frequently in patients aged older than 50 years and in those who complained especially about itching (P < .05).Conclusion
The prevalence of ocular demodicosis is significantly correlated with blepharitis and increases with age.999.
1000.
BACKGROUND: Imatinib is effective for a variety of hematologic and nonhematologic malignancies. Well-known ocular side effects are periorbital edema, epiphora, extraocular muscle palsy, and blepharoconjunctivitis. However, optic disc edema has not been reported as a complication of imatinib mesylate. Herein, we describe a patient with chronic myeloid leukemia (CML) who developed optic disc edema during treatment with imatinib. CASE: A 14-year-old Korean girl was referred to ophthalmology for a 3-week history of photopsia in both eyes. She had started taking imatinib daily 2 months previously for CML. At the initial exam, slit lamp showed optic disc edema in both eyes, even though visual acuity was 20/20 and other optic nerve function evaluations were within normal limits. We recommended to the oncologist discontinuation of the imatinib treatment. OBSERVATIONS: When the patient was followed for 1 week after stopping imatinib treatment, the frequency of photopsia decreased and the optic disc edema improved. Because a second examination 3 weeks after discontinuation of imatinib revealed much improved optic disc edema, she restarted the imatinib treatment. No ocular side effects have been noted so far. CONCLUSIONS: Optic disc edema should be considered one of the complications associated with imatinib. We propose discontinuation of the treatment for a short period when optic disc edema occurs. 相似文献