RESUMEN

Polluted water has become a concern for the scientific community as it causes many severe threats to living beings. Detection or removal of contaminants present in wastewater and attaining purity of water that can be used for various purposes are a primary responsibility. Different treatment methods have already been used for the purification of sewage. There is a need for low-cost, highly selective, and reusable materials that can efficiently remove pollutants or purify contaminated water. In this regard, MOFs have shown significant potential for applications such as supercapacitors, drug delivery, gas storage, pollutant adsorption, etc. The outstanding structural diversity, substantial surface areas, and adjustable pore sizes of MOFs make them superior candidates for wastewater treatment. This Review provides an overview of the interaction science and engineering (kinetic and thermodynamic aspects with interactions) underpinning MOFs for water purification. First, fundamental strategies for the synthesis methods of MOFs, different categories, and their applicability in wastewater treatment are summarized, followed by a detailed explanation of various interaction mechanisms. Finally, current challenges and future outlooks for research on MOF materials toward the adsorption of hazardous components are discussed. A new avenue for modifying their structural characteristics for the adsorption and separation of hazardous materials, which will undoubtedly direct future work, is also summarized.

RESUMEN

The rational construction of free-standing and flexible electrodes for application in electrochemical energy storage devices and next-generation supercapacitors is an emerging research focus. Herein, we prepared a redox-active ferrocene dicarboxylic acid (Fc)-based nickel metal-organic framework (MOF) on electrospun carbon nanofibers (NiFc-MOF@CNFs) via an in situ approach. This in situ approach avoided the aggregation of the MOF. The NiFc-MOF@CNF flexible electrode showed a high redox-active behavior owing to the presence of ferrocene and flexible carbon nanofibers, which led to unique properties, including high flexibility and lightweight. Furthermore, the prepared electrode was utilized in a supercapacitors (SC) without the use of any binder, which achieved a specific capacity of 460 C g-1 at 1 A g-1 with an excellent cyclic retention of 82.2% after 25 000 cycles and a good rate capability. A flexible asymmetric supercapacitor device was assembled, which delivered a high energy density of 56.25 W h kg-1 and a long-lasting cycling performance. Also, the prepared electrode could be used as a freestanding electrode in flexible devices at different bending angles. The obtained cyclic voltammetry curves showed negligible changes, indicating the high stability and good flexibility of the electrode. Thus, the use of the in situ strategy can lead to the uniform growth of redox-active MOFs or other porous materials on CNFs.

RESUMEN

A highly conductive and rationally constructed metal-organic framework (MOF)-derived metal phosphide with a carbonaceous nanostructure is a meticulous architecture toward the development of electrode materials for energy storage devices. Herein, we report a facile strategy to design and construct a new three-dimensional (3D) Cu-MOF via a solvent diffusion method at ambient temperature, which was authenticated by a single-crystal X-ray diffraction study, revealing a novel topology of (2,4,7)-connected three-nodal net named smm4. Nevertheless, the poor conductivity of pristine MOFs is a major bottleneck hindering their capacitance. To overcome this, we demonstrated an MOF-derived Cu3P/Cu@NC heterostructure via low-temperature phosphorization of Cu-MOF. The electronic and ionic diffusion kinetics in Cu3P/Cu@NC were improved due to the synergistic effects of the heterostructure. The as-prepared Cu3P/Cu@NC heterostructure electrode delivers a specific capacity of 540 C g-1 at 1 A g-1 with outstanding rate performance (190 C g-1 at 20 A g-1) and cycle stability (91% capacity retention after 10,000 cycles). Moreover, the assembled asymmetric solid-state supercapacitor (ASC) achieved a high energy density/power density of 45.5 Wh kg-1/7.98 kW kg-1 with a wide operating voltage (1.6 V). Long-term stable capacity retention (87.2%) was accomplished after 5000 cycles. These robust electrochemical performances suggest that the Cu3P/Cu@NC heterostructure is a suitable electrode material for supercapacitor applications.

RESUMEN

MXenes are a large family of two dimensional (2D) materials with high conductivity, redox activity and compositional diversity that have become front-runners in the materials world for a diverse range of energy storage applications. High-performing supercapacitors require electrode materials with high charge storage capabilities, excellent electrical conductivity for fast electron transfer, and the ability of fast charging/discharging with good cyclability. While MXenes show many of these properties, their energy storage capability is limited by a narrow electrochemically stable potential window due to irreversible oxidation under anodic potentials. Although transition metal oxides (TMOs) are often high-capacity materials with high redox activity, their cyclability and poor rate performance are persistent challenges because of their dissolution in aqueous electrolytes and mediocre conductivity. Forming heterostructures of MXenes with TMOs and using hybrid electrodes is a feasible approach to simultaneously increase the charge storage capacity of MXenes and improve the cyclability and rate performance of oxides. MXenes could also act as conductive substrates for the growth of oxides, which could perform as spacers to stop the aggregation of MXene sheets during charging/discharging and help in improving the supercapacitor performance. Moreover, TMOs could increase the interfacial contact between MXene sheets and help in providing short-diffusion ion channels. Hence, MXene/TMO heterostructures are promising for energy storage. This review summarizes the most recent developments in MXene/oxide heterostructures for supercapacitors and highlights the roles of individual components.

RESUMEN

The development of a MOFs-derived multilevel hierarchy in a single step still remains a challenging task. Herein, we have synthesized novel Cu-MOF via a slow diffusion method at ambient temperature and further utilized it as a precursor source for MOF-derived multilevel hierarchy (Cu/CuxO@NC, x = 1 and 2). This studies suggest that the organic ligands served as a source of an N-doped carbon matrix encapsulated with metal oxide nanoparticles which were confirmed by various characterization techniques; further BET analysis reveals a surface area of 178.46 m2/g. The synthesized multilevel hierarchy was utilized as an electro-active material in a supercapacitor that achieved a specific capacitance of 546.6 F g-1 at a current density of 1 A g-1 with a higher cyclic retention of 91.81% after 10 000 GCD cycles. Furthermore, the ASC device was fabricated using Cu/CuxO@NC as the positive electrode and carbon black as the negative electrode and utilized to enlighten the commercially available LED bulb. The fabricated ASC device was further employed for a two-electrode study which achieved a specific capacitance of 68 F g-1 along with a comparable energy density of 13.6 Wh kg-1. Furthermore, the electrode material was also explored for the oxygen evolution reaction (OER) in an alkaline medium with a low overpotential of 170 mV along with a Tafel slope of 95 mV dec-1 having long-term stability. The MOF-derived material has high durability, chemical stability, and efficient electrochemical performance. This work provides some new thoughts for the design and preparation of a multilevel hierarchy (Cu/CuxO@NC) via a single precursor source in a single step and explored multifunctional applications in energy storage and an energy conversion system.

RESUMEN

Purpose: To report the incidence, clinical features, potential risk factors, and outcomes of intraocular inflammation (IOI) following brolucizumab in Indian eyes. Methods: All consecutive patients diagnosed with brolucizumab-induced IOI from 10 centers in eastern India between October 2020 and April 2022 were included. Results: Of 758 injections given during the study period across centers, 13 IOI events (1.7%) were recorded attributable to brolucizumab. The IOI occurred after the first dose in two eyes (15%) (median 45 days after brolucizumab), second dose in six eyes (46%) (median = 8.5 days), and third dose (39%) in the remaining five eyes (median 7 days). Reinjections of brolucizumab were administered at a median interval of 6 weeks (interquartile range = 4-10 weeks) in the 11 eyes, where IOI occurred after the second or third dose. Eyes that experienced IOI after the third dose had received a significantly greater number of previous antivascular endothelial growth factor injections (median = 8) compared to those who developed it after the first or second dose (median = 4) (P = 0.001). Anterior chamber cells were seen in almost all eyes (n = 11, 85%), while peripheral retinal hemorrhages were seen in two eyes, and one eye showed branch artery occlusion. Two-thirds of patients (n = 8, 62%) recovered with a combination of topical and oral steroids, while remaining recovered with topical steroids alone. Irreversible visual loss was not seen in any eye, and median vision recovered to pre-IOI levels by 3 months' time point. Conclusion: Brolucizumab-induced IOI was relatively rare, occurring in 1.7% of eyes, was more common after the second or third injection, especially in those who required frequent reinjections every 6 weeks, and occurred earlier with increasing number of previous brolucizumab injections. Continued surveillance is necessary even after repeated doses of brolucizumab.

Asunto(s)

RESUMEN

Being cognizant of modern electronic devices, the scientists are continuing to investigate renewable green-energy resources for a decade. Amid different energy harvesting systems, the triboelectric nanogenerators (TENGs) have been found to be the most promising mechanical harvesting technology and have drawn attention to generate electrical energy. Thanks to its instant output power, choice to opt for wide-ranging materials, low maintenance cost, easy fabrication process and environmentally friendly nature. Due to numerous working modes of TENGs, it is dedicated to desired application at ambient conditions. In this review, an advance correlation of TENGs have been explained based on the variety of nanostructures, including 0D, 1D, 2D, 3D, metal organic frameworks (MOFs), coordination polymers (CPs), covalent organic frameworks (COFs), and perovskite materials. Moreover, an overview of previous and current perspectives of various nanomaterials, synthesis, fabrication and their applications in potential fields have been discussed in detail.

RESUMEN

The overuse of antibiotics in recent years presents a huge challenge to society for their removal from the environment. The prolonged presence of antibiotics as environmental pollutants results in the emergence of drug-resistant bacteria faster than new antibiotics to treat diseases they cause. Therefore, a rapid, sensitive, and cost-effective method is urgently required to detect and degrade antibiotics. Given this, a novel strategy has been devised for synthesizing Fe-doped carbon dots (Fe-N@CDs) and iron oxide-carbon dot hybrid nanoparticles (Fe3O4-CDs) in a single step for doxycycline detection and its degradation. For the very first time, the formation of two simultaneous products, i.e., Fe-N@CDs (0 D fluorescent carbon dots) and Fe3O4-CDs (magnetic nanoparticles) in a single step hydrothermal carbonization process by using a sole iron salt (FeCl2) and carbon precursor (citric acid) in the presence of ethylenediamine is reported. The as prepared Fe-N@CDs selectively detect doxycycline with a limit of detection value of 66 ng mL-1 and in the linear range from 0 mg mL-1 to 50 mg mL-1, whereas the other formed products, i.e., Fe3O4-CDs, degrade doxycycline by 70.26% in just 5 min by applying shear force using simply a kitchen blender. The results demonstrated the suitability and application scope in food and environment safety.

Asunto(s)

RESUMEN

STUDY DESIGN: Retrospective study. OBJECTIVE: To evaluate and compare the outcomes of single stage surgery for Tandem Spinal Stenosis (TSS) in elderly (Age ≥65 years) and younger patients (Age <65 years). SUMMARY OF BACKGROUND DATA: Tandem spinal stenosis among elderly is common and often missed diagnosed with delayed presentation. Literature evaluating efficacy and safety of single staged surgery for TSS in elderly patients is scanty. METHODS: Analysis of 74 patients with TSS managed with single stage posterior surgery from 2007 to 2016 was done. A total of 62 patients who satisfied our inclusion criteria were evaluated and subdivided into two groups based on age; Study group (age ≥65years)] (n = 32) and control group (age <65years) (n = 30). Perioperative, clinical/radiological parameters and postoperative complications and recovery rate were noted. RESULTS: The Mean ODI and mJOA showed significant improvement post-operatively in both groups however there was no significant difference between the two groups at final follow-up. There was no statistical difference in operative time, blood loss and hospital stay between the groups. As per Odom's criteria, 78.1% had excellent to good results in study group, while 83.3% had excellent to good results in control group. Postoperative complications were more in elderly group however, there was no significant difference among neurological or cardiopulmonary complications between both groups. CONCLUSIONS: Single stage surgery is safe & efficacious modality with less morbidity and optimal results in elderly patients with proper preoperative risk assessment. Our study showed that increased age does not proved to be deterrent in the outcome of single staged surgery in tandem spinal stenosis.

RESUMEN

BACKGROUND: Macular edema secondary to retinal vein occlusion (RVO) is an important cause of loss of vision. Intravitreal injections (IVI) of anti-vascular endothelial growth factor (VEGF) are the standard of care in this disease, as shown in numerous randomized controlled trials. The purpose of this study was to study the efficacy and safety of ranibizumab, an anti-VEGF agent, in the real-world setting. METHODS: This was 48 weeks, open-label, prospective, multicentre, observational study. Patients diagnosed with ME secondary to RVO were treated with IVI of Ranibizumab 0.5 mg in real-world conditions. Efficacy was measured by improvement seen in best-corrected visual acuity (BCVA) in terms of Early Treatment of Diabetic Retinopathy Study (ETDRS) Letter Scores and change in central retinal thickness (CRT) measured by optical coherence tomography. RESULTS: One hundred eyes of 100 patients (79 with branch retinal vein occlusion and 21 with central retinal vein occlusion) were recruited in the study. The mean (standard deviation, SD) BCVA was 52.8 (21.99) letters at baseline and 62.3 (24.40) letters at week 48. From baseline, there was a significant improvement in BCVA by 7.7 letters (p = 0.001) at 48 weeks. The mean (SD) of CRT was 479.9 (216.25) µm at baseline and it decreased significantly to 284.9 (171.35) µm at week 48 (p < 0.001). During the study period, the average number of intravitreal injections was 3.5 per patient. There was no report of endophthalmitis in any eye. CONCLUSIONS: Ranibizumab is well tolerated and effective in treating macular edema secondary to RVO in real-world clinical settings. However, there is under-treatment compared to controlled clinical trials, and the gain in vision is sub-optimal with under-treatment. TRIAL REGISTRATION: Clinical Trials Registry - India: CTRI/2015/07/005985 .

Asunto(s)

Asunto(s)

RESUMEN

PURPOSE: To compare the safety and efficacy of different methods of posterior subtenon (PST) injection of corticosteroids in the treatment of cystoid macular edema secondary to intermediate uveitis. DESIGN: Prospective comparative randomized interventional study. PARTICIPANTS: A total number of 30 eyes with cystoid macular edema secondary to intermediate uveitis were examined. METHODS: Patients were randomized into 3 treatment groups of 10 eyes each. Each group received PST injection of triamcinolone acetonide 0.5 mL (20 mg) by one of three methods: cannula method (group 1), Smith and Nozik method (group 2), or orbital floor injection method (group 3). Patients underwent Snellen's and ETDRS visual acuity (VA) testing, clinical evaluation, optical coherence tomography (OCT), and fundus fluorescein angiography (FFA) at baseline and follow-up visits. OUTCOME MEASURES: Changes in Snellen and ETDRS VA, OCT retinal thickness and assessments of safety were recorded in follow-up visits. RESULTS: Postintervention patients were followed up at the 1st, 2nd, 6th, and 12th weeks. Statistically significant (p = .00) improvement in VA was present in group1 from 0.25 +/- 0.08 (mean +/- standard deviation) to 0.75 +/- 0.24, in group 2 from 0.29 +/- 0.12 to 0.78 +/- 0.23, and in group 3 from 0.24 +/- 0.10 to 0.72 +/- 0.27. Statistically significant decrease in OCT central macular thickness (43.97% in group 1, 32.46% in group 2, and 29.75% in group 3) was noted at 12 weeks. However, the difference between individual groups at each visit did not reach statistical significance. Steroid-induced rise in intraocular pressure was observed in all the three groups with no statistical difference between individual groups. CONCLUSIONS: The different methods of PST injection are equally efficacious in terms of improving visual acuity. However, the cannula method achieves the greatest quantitative reduction in macular thickness. As the cannula method is as efficacious as Smith and Nozik method it may be a preferable method to deliver posterior subtenon injection of corticosteroids.

Asunto(s)

RESUMEN

BACKGROUND: To evaluate the efficacy and safety of intravitreal bevacizumab (Avastin) in the treatment of subretinal neovascularization (SRNV) secondary to type 2A idiopathic juxtafoveal telangiectasia (IJT). METHODS: Intravitreal bevacizumab (1.25 mg/0.05 ml) was injected as primary treatment into six eyes of six patients with SRNV due to IJT in this nonrandomized, interventional case series. The best-corrected visual acuity (BCVA) was measured and the optical coherence tomography (OCT) and fundus fluorescein angiography (FFA) findings were examined before and after treatment. The patients were followed up for 3-6 months. RESULTS: Pre-injection BCVA measured 20/400 to 20/120 (mean 20/200). After a mean follow-up of 4.2 months, post-injection BCVA measured 20/200 to 20/50 (mean 20/100). At last visit BCVA improved two or more lines in five eyes (83%) and remained the same in one eye (17%). The mean central foveal thickness improved from 263 microm (range, 165 to 393 microm) to 201 microm (range, 126 to 351 microm), representing an average reduction of 62 mum. Only one eye received more than one (2) bevacizumab injections. No significant complications were observed. CONCLUSIONS: In this small series, intravitreal bevacizumab appears to be a safe and effective treatment for SRNV secondary to type 2A IJT.

Asunto(s)