Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 39
Filtrar
Más filtros

Bases de datos
Tipo del documento
Intervalo de año de publicación
1.
Anal Chem ; 96(21): 8221-8233, 2024 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-38740384

RESUMEN

Compared with traditional "lock-key mode" biosensors, a sensor array consists of a series of sensing elements based on intermolecular interactions (typically hydrogen bonds, van der Waals forces, and electrostatic interactions). At the same time, sensor arrays also have the advantages of fast response, high sensitivity, low energy consumption, low cost, rich output signals, and imageability, which have attracted widespread attention from researchers. Nanozymes are nanomaterials which own enzyme-like properties. Because of the adjustable activity, high stability, and cost effectiveness of nanozymes, they are potential candidates for construction of sensor arrays to output different signals from analytes through the chemoresponse of colorants, which solves the shortcomings of traditional sensors that they cannot support multiple detection and lack universality. Recently, a sensor array based on nanozymes as nonspecific recognition receptors has attracted much more attention from researchers and has been applied to precise recognition of proteins, bacteria, and heavy metals. In this perspective, attention is given to nanozymes and the regulation of their enzyme-like activity. Particularly, the building principles and methods for sensor arrays based on nanozymes are analyzed, and the applications are summarized. Finally, the approaches to overcome the challenges and perspectives are also presented and analyzed for facilitating further research and development of nanozyme sensor arrays. This perspective should be helpful for gaining insight into research ideas within the field of nanozyme sensor arrays.


Asunto(s)
Técnicas Biosensibles , Nanoestructuras , Nanoestructuras/química , Enzimas/metabolismo , Enzimas/química
2.
J Neuroophthalmol ; 43(4): 541-546, 2023 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-37166977

RESUMEN

BACKGROUND: The utilization of flow diverters (FDs) in the treatment of high-flow Type A carotid cavernous fistulas (CCFs) has been described before mainly as an adjunct to the traditional endovascular techniques and rarely as a stand-alone treatment. In this study, we retrospectively evaluated our experience with FDs as the solo nonadjunctive treatment of Type A CCF with severe cortical venous reflux (CVR). METHODS: A retrospective review was performed of patients with Type A CCFs who were treated using FDs' patch technique (PT). Patients' demographics, clinical data, and preoperative and postoperative ocular examination were recorded. The procedure technique, pipeline embolization device (PED) diameters, and immediate and late procedure outcomes were described. RESULTS: Three patients were included in this case series. All patients had history of trauma and presented with decreased visual acuity, cranial nerve II deficit, limited extraocular muscles' movement, and increased intraocular pressure (IOP). Diagnostic angiography was performed, which confirmed high-flow Type A CCF. Endovascular treatment was performed through distal radial access in 2 patients and femoral access in 1 patient by deploying 4 sequentially enlarging PEDs with immediate resolution of the ocular symptoms. Follow-up angiography confirmed complete resolution of CCF in 2 patients. One patient was lost to follow-up; however, angiogram at 4 months demonstrated residual small CCF with significant improvement from postprocedure angiogram. CONCLUSIONS: The patch technique using sequentially enlarging FDs is a reasonable alternative solo technique for the treatment of direct CCF symptoms and results in immediate resolution of CVR while preserving the cavernous sinus anatomy.


Asunto(s)
Fístula del Seno Cavernoso de la Carótida , Seno Cavernoso , Embolización Terapéutica , Procedimientos Endovasculares , Humanos , Fístula del Seno Cavernoso de la Carótida/diagnóstico , Fístula del Seno Cavernoso de la Carótida/terapia , Estudios Retrospectivos , Resultado del Tratamiento
3.
Pak J Med Sci ; 38(8): 2202-2207, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36415281

RESUMEN

Objectives: To compare the levels of glycated albumin and angiopoietin-2 in Type-Two diabetics with and without diabetic retinopathy. Methods: It was a cross-sectional comparative study done at University of Health Sciences, Lahore after collecting data from recruited patients from the outpatient department of Layton Rahmatulla Benevolent Trust Eye Hospital, Lahore from 1st July, 2016 to 30th Aug., 2017. A total of 80 type two diabetics of both genders fulfilling the inclusion criteria were included and divided in two groups based on absence and presence of diabetic retinopathy. Obtained data were analyzed using IBM SPSS for Windows software (version 22). For comparison of both groups, Independent "t" Test or Mann-Whitney U tests were applied accordingly. For correlation of quantitative variables in each group, Spearman rho correlation and Pearson correlation test were applied depending upon normality of data. Results: Among 80 type-two diabetics, 42 (52.5%) patients had diabetic retinopathy and 38 (47.5%) were without diabetic retinopathy. Overall, females (62.5%) outnumbered males (37.5%). Both study group were age matched (p=0.45). Mean serum albumin in diabetic retinopathy and non-diabetic retinopathy group was 4.20 ±0.56 gm/dL and 4.43 ±0.39 gm/dL respectively (p=0.031). In diabetic retinopathy group, mean glycated albumin was 1.48 (0.63-1.76) gm/dL and median IQR in non-diabetic retinopathy was 0.52 (0.23-1.10) gm/dL (p=0.003). In diabetic retinopathy group, mean glycated albumin (percent) was 30.71±18.63% and in non-diabetic retinopathy group, the median IQR was 11.80 (5.06-27.25) (p= 0.001). The angiopoietin-2 median IQR in diabetic retinopathy group 5.70 (5.47-5.80) was significantly different (p=0.033) from diabetics without diabetic retinopathy groups 5.40 (4.97-5.60). Conclusion: Our study reported raised levels of glycated albumin (percent) and angiopoietin-2 in type-two diabetics, highlighting their possible involvement in disease and its progression.

4.
Neurosurg Focus ; 46(2): E14, 2019 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-30717064

RESUMEN

OBJECTIVESteno-occlusive diseases of the cerebral vasculature have been associated with cognitive decline. The authors performed a systematic review of the existing literature on intracranial steno-occlusive disease, including intracranial atherosclerosis and moyamoya disease (MMD), to determine the extent and quality of evidence for the effect of revascularization on cognitive performance.METHODSA systematic search of PubMed/MEDLINE, the Thomson Reuters Web of Science Core Collection, and the KCI Korean Journal Database was performed to identify randomized controlled trials (RCTs) in the English-language literature and observational studies that compared cognitive outcomes before and after revascularization in patients with steno-occlusive disease of the intracranial vasculature, from which data were extracted and analyzed.RESULTSNine papers were included, consisting of 2 RCTs and 7 observational cohort studies. Results from 2 randomized trials including 142 patients with symptomatic intracranial atherosclerotic steno-occlusion found no additional benefit to revascularization when added to maximal medical therapy. The certainty in the results of these trials was limited by concerns for bias and indirectness. Results from 7 observational trials including 282 patients found some cognitive benefit for revascularization for symptomatic atherosclerotic steno-occlusion and for steno-occlusion related to MMD in children. The certainty of these conclusions was low to very low, due to both inherent limitations in observational studies for inferring causality and concerns for added risk of bias and indirectness in some studies.CONCLUSIONSThe effects of revascularization on cognitive performance in intracranial steno-occlusive disease remain uncertain due to limitations in existing studies. More well-designed randomized trials and observational studies are needed to determine if revascularization can arrest or reverse cognitive decline in these patients.


Asunto(s)
Revascularización Cerebral/tendencias , Trastornos Cerebrovasculares/psicología , Trastornos Cerebrovasculares/cirugía , Cognición/fisiología , Revascularización Cerebral/métodos , Trastornos Cerebrovasculares/diagnóstico por imagen , Humanos , Arteriosclerosis Intracraneal/diagnóstico por imagen , Arteriosclerosis Intracraneal/psicología , Arteriosclerosis Intracraneal/cirugía , Enfermedad de Moyamoya/diagnóstico por imagen , Enfermedad de Moyamoya/psicología , Enfermedad de Moyamoya/cirugía , Estudios Observacionales como Asunto/métodos , Ensayos Clínicos Controlados Aleatorios como Asunto/métodos , Resultado del Tratamiento
5.
Childs Nerv Syst ; 33(6): 999-1003, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28251324

RESUMEN

INTRODUCTION: Arterial cerebral aneurysms in the neonatal population are rare, and while the association of interrupted aortic arch and intracranial aneurysm has been reported in the adult and pediatric population (three cases each), to date, it has not been reported in the neonate. CASE REPORT: We report the case of a 26-day-old girl who presented with a generalized seizure 2 weeks after undergoing congenital heart surgery. Head CT revealed diffuse SAH with a 1.7 × 2.9-cm frontal intra-parenchymal hematoma with subdural extension producing 3 mm of midline shift. CTA evidenced a 2-mm left MCA bifurcation aneurysm, and the patient was taken to the operating room for clipping. Twenty-four-hour post-operative head CT showed ventriculomegaly and an EVD was placed. It was removed 4 days later without the need for permanent CSF diversion, and after this, her hospital stay was uneventful and she was discharged home. At 25 months of age, she was meeting developmental milestones. At this time, she underwent further heart surgery and expired shortly thereafter due to cardiomyopathy. CONCLUSION: Here, we report the successful treatment of a ruptured neonatal aneurysm, and the first known case associated with interrupted aortic arch. Given the time and presentation, this patient likely illustrates the role of hemodynamic factors in the rupture of neonatal aneurysms. In reviewing all of the reported cases of neonatal aneurysms, promptly securing the aneurysm by either open clipping, parent vessel occlusion, or endovascular coiling is strongly preferable to no surgical intervention.


Asunto(s)
Aneurisma Roto/diagnóstico por imagen , Aorta Torácica/anomalías , Aorta Torácica/diagnóstico por imagen , Aneurisma Intracraneal/diagnóstico por imagen , Aneurisma Roto/cirugía , Aorta Torácica/cirugía , Femenino , Humanos , Recién Nacido , Aneurisma Intracraneal/cirugía
6.
J Phys Chem A ; 120(1): 118-27, 2016 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-26673943

RESUMEN

In the present study, a novel TiO2/Ti film with enhanced {001} facets was synthesized by the hydrothermal technique followed by calcination for studying the removal of bezafibrate (BZF), from an aqueous environment. The synthesized photocatalyst was characterized by FE-SEM, XRD, HR-TEM, and PL-technique. The second-order rate constant of (•)OH with BZF was found to be 5.66 × 10(9) M(-1) s(-1). The steady state [(•)OH] was measured as 1.16 × 10(-11) M, on the basis of oxidation of terephthalic acid. The photocatalytic degradation of BZF followed pseudo-first-order kinetics according to the Langmuir-Hinshelwood model (k1 = 2.617 mg L(-1) min(-1) and k2 = 0.0796 (mg L(-1))(-1)). The effects of concentration and the nature of various additives including inorganic anions (NO3(-), NO2(-), HCO3(-), CO3(2-), Cl(-)) and organic species (fulvic acid) and initial solution pHs (2, 4, 6, 9) on photocatalytic degradation of BZF were investigated. It was found that the nature and concentration of studied additives significantly affected the photocatalytic degradation of BZF. The efficiency of the photocatalytic degradation process in terms of electrical energy per order was estimated. Degradation schemes were proposed on the basis of the identified degradation byproducts by ultraperformance liquid chromatography.

7.
J Phys Chem A ; 120(50): 9916-9931, 2016 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-27959545

RESUMEN

In this study, a novel immobilized TiO2/Ti film with exposed {001} facets was prepared via a facile one-pot hydrothermal route for the degradation of norfloxacin from aqueous media. The effects of various hydrothermal conditions (i.e., solution pH, hydrothermal time (HT) and HF concentration) on the growth of {001} faceted TiO2/Ti film were investigated. The maximum photocatalytic performance of {001} faceted TiO2/Ti film was observed when prepared at pH 2.62, HT of 3 h and at HF concentration of 0.02 M. The as-prepared {001} faceted TiO2/Ti films were fully characterized by field-emission scanning electron microscope (FE-SEM), X-ray diffraction (XRD), high resolution transmission electron microscope (HR-TEM), and X-ray photoelectron spectroscopy (XPS). More importantly, the as-prepared {001} faceted TiO2/Ti film exhibited excellent photocatalytic performance toward degradation of norfloxacin in various water matrices (Milli-Q water, tap water, river water and synthetic wastewater). The individual influence of various anions (SO42-, HCO3-, NO3-, Cl-) and cations (K+, Ca2+, Mg2+, Cu2+, Na+, Fe3+) usually present in the real water samples on the photocatalytic performance of as-prepared TiO2/Ti film with exposed {001} facet was investigated. The mechanistic studies revealed that •OH is mainly involved in the photocatalytic degradation of norfloxacin by {001} faceted TiO2/Ti film. In addition, norfloxacin degradation byproducts were investigated, on the basis of which degradation schemes were proposed.


Asunto(s)
Calor , Norfloxacino/química , Titanio/química , Catálisis , Estructura Molecular , Fotoquímica , Agua/química
8.
Int J Biol Macromol ; 260(Pt 1): 129376, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38262825

RESUMEN

Currently, hydrogel-based flexible devices become hot areas for scientists in the field of electronic devices, artificial intelligence, human motion detection, and electronic skin. These devices show responses to external stimuli (mechanical signals) and convert them into electrical signals (resistance, current, and voltage). However, the applications of the hydrogel-based sensor are hampered due to low mechanical properties, high time response, low fatigue resistance, low self-healing nature, and low sensing range. Herein, a strain sensing conductive hydrogel constructed from the CNCs (cellulose nanocrystal) reinforced, in which acrylamide and butyl acrylate work as hydrophilic and hydrophobic monomers respectively. The incorporation of CNCs in the polymeric system has a direct effect on their mechanical properties. The hydrogel having a high amount of CNCs (C4), its fracture stress and fracture strain reached 371.2 kPa and 2108 % respectively as well as self-healing of C4 hydrogel Broke at 499 % strain and bore 197 kPa stress. The elastic behavior of the hydrogels was confirmed by the rheological parameter frequency sweep and strain amplitude. Besides this our designed hydrogel shows an excellent response to deformation with conductivity 420 mS m-1, shows response to small strain (10 %) and large (400 %) strain, and has excellent anti-fatigue resistance with continuous stretching for 700 s at 300 % strain, with 140 msec response time, and gauge factor 7.4 at 750 % strain. The C4 hydrogel can also work as electronic skin when it is applied to different joints like the finger, elbow, neck, etc. The prepared hydrogel can also work as an electronic pen when it is worn to a plastic pen cover.


Asunto(s)
Celulosa , Hidrogeles , Humanos , Inteligencia Artificial , Conductividad Eléctrica , Cinacalcet , Electrónica
9.
ACS Omega ; 9(7): 7692-7704, 2024 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-38405485

RESUMEN

A novel adsorbent designated as terpolymer hydrogel (gellan gum-co-acrylamide-co-methacrylic acid) was prepared by free radical polymerization of gellan gum (GG), methacrylic acid (MAA), and acrylamide (AAm) using N,N-methylene bis-acrylamide (MBA) as cross-linker and ammonium per sulfate (APS) as the initiator of the reaction. The synthesized gel was characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), and thermogravimetric analysis (TGA) and was used for the adsorptive removal of methyl violet (MV) and Fuchsin Basic (FB) dyes from aqueous solution. The effect of temperature, contact time, pH, and concentration on them under the study adsorption process was evaluated. Freundlich isotherm and pseudo-second-order kinetic models were found to be best in fitting the isothermal and kinetics data. The water diffusion and % swelling of hydrogel were studied at various pH in distilled water and at neutral pH in tap water. The diffusion was found to be of Fickian type with a maximum swelling of 5132%. The maximum adsorption capacity was 233 mg/g against MV and 200 mg/g against FB dyes. The swelling and adsorption were pH dependent and increased with increase in pH. The enthalpy, Gibbs free energy, and entropy changes of adsorption for both the dyes indicated the adsorption process to be exothermic, feasible, and spontaneous. The hydrogel was successfully regenerated using acetone and distilled water for five cycles and still, its dye removal efficiency was 80% of its original value. The poly(GG-co-AAm-co-MAA) hydrogel successfully removed the selected dyes from water and could thus be used as an efficient alternative sorbent for cationic dye removal from aqueous solutions.

10.
J Mater Chem B ; 12(25): 6190-6202, 2024 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-38832839

RESUMEN

Metal organic frameworks (MOFs) have garnered significant attention in the development of stretchable and wearable conductive hydrogels for flexible transducers. However, MOFs used in hydrogel networks have been hampered by low mechanical performance and poor dispersibility in aqueous solutions, which affect the performance of hydrogels, including low toughness, limited self-recovery, short working ranges, low conductivity, and prolonged response-recovery times. To address these shortcomings, a novel approach was adopted in which micelle co-polymerization was used for the ex situ synthesis of Zn-MOF-based hydrogels with exceptional stretchability, robust toughness, anti-fatigue properties, and commendable conductivity. This breakthrough involved the ex situ integration of Zn-MOFs into hydrophobically cross-linked polymer chains. Here the micelles of EHDDAB had two functions, first they uniformly dispersed the Zn-MOFs and secondly they dynamically cross-linked the polymer chains, profoundly influencing the mechanical characteristics of the hydrogels. The non-covalent synergistic interactions introduced by Zn-MOFs endowed the hydrogels with the capacity for high stretchability, high stress, rapid self-recovery, anti-fatigue properties, and conductivity, all achieved without external stimuli. Furthermore, hydrogels based on Zn-MOFs can serve as durable and highly sensitive flexible transducers, adept at detecting diverse mechanical deformations with swift response-recovery times and high gauge factor values. Consequently, these hydrogels can be tailored to function as wearable strain sensors capable of sensing significant human joint movements, such as wrist bending, and motions involving the wrist, fingers, and elbows. Similarly, they excel at monitoring subtle human motions, such as speech pronunciation, distinguishing between different words, as well as detecting swallowing and larynx vibrations during various activities. Beyond these applications, the hydrogels exhibit proficiency in distinguishing and reproducing various written words with reliability. The Zn-MOF-based hydrogels hold promising potential for development in electronic skin, medical monitoring, soft robotics, and flexible touch panels.


Asunto(s)
Conductividad Eléctrica , Hidrogeles , Estructuras Metalorgánicas , Dispositivos Electrónicos Vestibles , Hidrogeles/química , Humanos , Estructuras Metalorgánicas/química , Zinc/química , Transductores
11.
Heliyon ; 10(4): e25836, 2024 Feb 29.
Artículo en Inglés | MEDLINE | ID: mdl-38375313

RESUMEN

Most of the dyes used in various industries are non-biodegradable and carcinogenic in nature. Therefore, elimination of dyes from textile wastes is mandatory to safeguard the life of human, aquatic animals and aquatic plants. In this connection an effective and eco-friendly hydrogel was synthesized from acrylamide, cellulose, clay, and copper salt abbreviated as AMPS(PHE-Ce)/MC-Cu. The fabricated hydrogel was used as sorbent and catalyst for the adsorption and catalytic reduction of basic blue 3. SEM analysis showed granular texture with small holes or cracks which is basic criteria for an adsorbent surface. The results showed that the BET surface area and the Langmuir surface area were, respectively, 27.87 and 40.32 m2/g. The FTIR analysis confirmed the synthesis of hydrogel, as is evident from peaks at 3500, 3439, 2996, 2414, and 1650 cm-1, which indicated the presence of OH or NH, -C-O-C-, CH3, (C[bond, double bond]O), C-N bonds correspondingly. Thermal stability was confirmed by TGA analysis where weight loss in three stages has been observed. The presence of copper was confirmed through EDX (5.02%) indicating the incorporation of cupper nanoparticles in hydrogel surface. The high adsorption capability of 1590 mg/g as recorded for basic blue-3 dye indicates it to be an efficient adsorbent. The swelling behavior characterized by Fickian diffusion up to 7898% clearly indicated significant swelling. Pseudo 2nd-order kinetics and the Langmuir isotherm models were more fit in unfolding kinetics and isothermal data indicating chemisorption with monolayer sorption as evident from the high R2 values (0.999) of each model. Thermodynamics considerations indicated that the adsorption process is endothermic with a positive enthalpy value of 1371.32 Jmol-1. The positive entropy value of 19.70 J/mol.K signifies a higher degree of disorder at the solid-liquid interface. The findings provided a valuable insights into the hydrogel's capacity to adsorb cationic dyes and reduce them catalytically, pointing towards its potential applications in addressing environmental challenges.

12.
Heliyon ; 10(7): e28290, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38689953

RESUMEN

In this work there was investigated the synergistic effect of the nanomaterials-the Montmorillonite (MMT) and the vanadium pentoxide (V2O5) on the polyvinyl alcohol (PVA)/starch composite. The composite films were prepared by the solvent casting method. The characterization of the composites showed that the addition of the MMT and the V2O5 to PVA/starch composite decreased the water solubility and water absorption capacity of the film. Both of the reinforcement materials enriched values of thermal conductivity and thermal stability of the composite. The TG/DTA and universal testing machine (UTM) analysis exhibited that MMT and V2O5 augmented the thermal robustness and tensile strength of composites and decreased the strain to break. It was also observed that greater MMT concentration accelerates mechanical strength deterioration of the film owing to agglomeration. The scanning electron microscopy (SEM) analysis reflected great change in the surface morphology of the films in the presence and absence of MMT and V2O5. This was due to the interaction amid constituents of the composite. The chemical interaction between the PVA, Starch, MMT and the V2O5 was also established via Fourier-transform infrared spectroscopy (FTIR) analysis, which revealed fluctuations in the absorbance position and intensity of the PVA/Starch. Antimicrobial activities against seven different cultures of bacteria (both-gram positive and -negative) and one fungus (Candida albicans), exposed that antimicrobial performance of the PVA amplified upon addition of the starch, MMT and V2O5, making these composites prospective candidates for the biodegradable packaging materials.

13.
Int J Biol Macromol ; 246: 125666, 2023 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-37406904

RESUMEN

Hydrophobically associated conductive hydrogels got great attention due to their excellent properties like stretchability, energy dissipation mechanism, and strain sensor. But hydrophobically associated hydrogels have poor mechanical properties and time response to external stimuli. To enhance the mechanical properties and response to stimuli, Acrylamide- co-Butyl acrylate/Gum based conductive hydrogels were prepared. SDS works as a cross-linker and micelle-forming agent while NaCl makes hydrogel as conductive. The results show that our % strain sensing reached up to 400 %, and fracture stress and fracture strain reached to 0.5 MPa and 401 % respectively. Besides this, it's having an excellent response to continuous stretching and unstretching multiple cycles without any fracture up to 180 s and an excellent time response of 190 s. The conductivity of the hydrogel was 0.20 Sm-1. The hydrophobic hydrogels showed a clear and quick response to human motions like finger, wresting, writing, speaking, etc. Interestingly, our prepared hydrogels can detect the mood of the human face. Similarly, the hydrogels were found efficient in bridging the surface of electronic devices with human skin. This indicates that our prepared hydrogels can monitor human body motion and will replace the existing materials used in strain sensors in the near future.


Asunto(s)
Galactanos , Hidrogeles , Humanos , Mananos , Conductividad Eléctrica , Electrónica
14.
J Mech Behav Biomed Mater ; 138: 105610, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36509014

RESUMEN

Conductive hydrogels attract the attention of researchers worldwide, especially in the field of flexible sensors like strain and pressure. These flexible materials have potential applications in the field of electronic skin, soft robotics, energy storage, and human motion detection. However, its practical application is limited due to low stretchability, high hysteresis energy, low conductivity, long-range strain sensitivity, and high response time. It's still a challenging job to endow all these properties in a single hydrogel network. In the present work, cellulose nano crystals (CNCs) reinforced hydrophobically associated gels were developed using APS as a source of radical polymerization, acrylamide and lauryl methacrylate were used as a monomer. CNCs reinforced the hydrophobically associated hydrogels through hydrogen bonding to retain the hydrogel's network structure. Hydrogels consist of dual crosslinking, which demonstrate exceptional mechanical performance (fracture stress and strain, toughness, and Young's modulus). The low hysteresis energy (10.9 kJm-3) and high conductivity (22.97 mS/cm) make the hydrogels a strong candidate for strain sensors with high sensitivity (GF = 19.25 at 700% strain) and a fast response time of 200 ms. Cyclic performance was also investigated up to 300 continuous cycles. After 300 cycles, the hydrogels were still stable and no considerable change was observed. These hydrogels are capable of sensing different human motions like wrist, finger bending, and neck (up-down and straight and right/left motion of neck). The hydrogels also demonstrate changes in current in response to swallowing, different speaking words, and writing different alphabets. These results suggest that our prepared materials can sense different small and large human motions, and also could be used in any electronic device where strain sensing is required.


Asunto(s)
Celulosa , Nanopartículas , Humanos , Polímeros , Hidrogeles , Movimiento (Física) , Cinacalcet , Conductividad Eléctrica
15.
Heliyon ; 9(9): e19780, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37809951

RESUMEN

Textile effluent's treatment is highly desired due to the presence of hazardous, water-soluble and non-biodegradable dyes that not only have harmful effect on the environment but on living beings as well. Treatment of these pollutants by sorption through biosorbents is considered to be a best method of choice due to greener nature of the processes. In this connection hydrogel sorbents might be an intriguing option due to its straightforward application, great efficacy, easy synthesis, rapid turnaround, and potential of recycling. Herein, novel hydrogel was prepared using Gellan Gum and acrylic acid (GG-co-AAc) which were then characterized by instrumental techniques like UV/visible and FTIR spectroscopy, SEM, EDX and XRD. The anionic hydrogel's adsorption capacity, swelling behavior, and sorption potential were determined using Rhodamine-B as potential environmental pollutant. The hydrogel exhibited an impressive adsorption capacity of 1250 mg/g. Swelling experiments were performed in Milli-Q distilled water at different pH levels, reaching maximum swelling of 3230% after 23 h as determined through Fickian diffusion. At pH 7, the anionic hydrogel's sorption potential was thoroughly studied in the subsequent experiments. The adsorption process was found to follow the Langmuir isotherm, indicating a monolayer adsorption mechanism supported by higher R2 values compared to the Freundlich isotherm. Thermodynamic analysis revealed the exothermic nature of the adsorption process, with a negative enthalpy value of -11371 KJmol-1 and negative entropy value of -26.39 Jmol-1K-1, suggesting a less ordered system. These findings provide valuable insights into the adsorption characteristics and potential applications of the synthesized anionic hydrogel.

16.
Environ Technol ; 44(7): 911-920, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34586969

RESUMEN

Nitrate as an important water pollutant, causing eutrophication was analyzed in Pakistan at different water sources (hand pump (HP), bore hole (BH) and tube well (TW)) to assess the contamination level caused by NO3-. NO3- concentrations in the HP water samples were 31 mg L-1 to 59 mg L-1, in BH 20 mg L-1 to 79 mg L-1 while in TW water samples it was between 29 to 55 mg L-1. The association of NO3- with other selected parameter in groundwater can be determined by using statistical approaches. Different physicochemical parameters (pH, electrical conductivity (EC), temperature and dissolved oxygen (DO)) were studied in groundwater samples of the research district. The Pearson correlation coefficient (r) for groundwater characteristics were calculated. Hierarchical Cluster Analysis (HCA) was used to categorize samples based on their groundwater quality similarities and to find links between groundwater quality factors. The key relationship of the groundwater for HP samples on EC and TDS (r = 1) had a great correlation, while all other parameters correlations were lower (r = 0.40), BH's parameters on WT and WSD (r = 0.57), WT and pH (r = 0.57), EC and DO (r = 0.50), DO and TDS (0.50), EC and TDS (r = 1) had a quite high correlation, while all other parameters correlations were less than (r = 0.40), on the other hand, tube well parameters on TDS and EC (r = 1) had a perfect correlation, DO and pH (r = 0.75) parameters correlations were less than (r = 0.40).


Asunto(s)
Agua Subterránea , Contaminantes Químicos del Agua , Nitratos/análisis , Calidad del Agua , Monitoreo del Ambiente , Agua Subterránea/análisis , Compuestos Orgánicos , Agua , Contaminantes Químicos del Agua/análisis
17.
J Neurosurg Case Lessons ; 4(13)2022 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-36164672

RESUMEN

BACKGROUND: Frontal mucoceles develop due to accumulation of mucoid secretions within the frontal sinuses. They can lead to serious consequences with further expansion and destruction of the surrounding bones or infection that might spread intracranially. OBSERVATIONS: The authors present a case of a 37-year-old male with a frontal mucocele and the rare presentation of Pott's puffy tumor and an epidural-cutaneous fistula, as well as a literature review of previously reported cases of epidural cutaneous fistula and sinocutaneous fistula, their predisposing factors, and their management. LESSONS: A mucocele is a benign entity that can rarely present with potentially significant complications. Open surgery is required in patients who have frontal sinus posterior wall involvement, osteomyelitis, or intracranial involvement.

18.
RSC Adv ; 12(30): 19072-19085, 2022 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-35865600

RESUMEN

Previously, solid-state electrode materials have been utilized for the fabrication of energy storage devices; however, their application is impeded by their brittle nature and ion mobility problems. To address issues faced in such a modern era where energy saving and utility is of prior importance, a novel approach has been applied for the preparation of electrode materials based on polyacrylamide hydrogels embedded with reduced graphene oxide and transition metals, namely, Cu2+ and Zn2+. The fabricated hydrogel exhibits high electrical properties and flexibility that make it a favorable candidate to be used in energy storage devices, where both elastic and electrical properties are desired. For the first time, a multi-cross-linked polyacrylamide hydrogel was constructed and compared in the presence of other electro-active materials such as reduced graphene oxide and transition metals. Polyacrylamide hydrogels embedded with reduced graphene oxide demonstrate excellent electrical properties such as specific capacitance, least impedance, low phase angle shift and AC conductivity of 22.92 F g-1, 2115 Ω, 2.88° and 0.67 µÎ´ m-1 respectively as compared to Cu2+- and Zn2+-loaded hydrogels, which block all available active sites causing an increase in impedance with a parallel decrease in capacitance. The capacitance retention and coulombic efficiency calculated were 88.22% and 77.23% respectively, indicating high stability up to 150 cycles at 0.1 A g-1. Storage moduli obtained were 10.52 kPa, which infers the more elastic nature of the hydrogel loaded with graphene oxide than that of other synthesized hydrogels.

19.
Curr Radiol Rep ; 9(4): 4, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33717661

RESUMEN

PURPOSE: Despite an overall reduction in the number of stroke cases presenting to hospitals during the COVID-19 pandemic, a remarkably high incidence of acute cerebrovascular disease associated with the infection has been reported. In this systematic review, we assess the neurological outcomes and complications of endovascular thrombectomy (EVT) for large vessel occlusions (LVO) in COVID-19 patients. METHODS: A literature search was performed in PubMed from December 1, 2019 through September 1st, 2020 using different combinations of suitable keywords. Ten studies reporting EVT outcomes and complications were identified. Two studies that included non-LVO pathologies and COVID-19 negative patients with the outcomes analysis were excluded. Patient demographics, comorbidities, anatomic thrombus location, neurological and angiographic outcomes were assessed. RESULTS: A total of 8 studies, in addition to our institutional case series, were ultimately included in this review. The mean age was 62.2 years, of which 67.6% were males. M1 segment involvement was the most commonly reported (53.8%) thrombus location. The mean NIHSS at presentation was 20.4 with no significant change at 24 h. Successful revascularization (TICI ≥ 2b) was achieved in 89%. Early proximal cerebral re-occlusion was reported in 6 patients (11%) and cerebral hemorrhage in 3 patients (4%). In hospital mortality was reported in 15 patients (28.8%). CONCLUSION: Despite angiographically successful EVT of LVOs in the majority of patients, this literature analysis demonstrates overall poor outcomes and high mortality in COVID-19 patients post EVT. An unusual incidence of early intracerebral proximal arterial re-occlusion was notable.

20.
Microsc Res Tech ; 84(8): 1673-1684, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33576066

RESUMEN

We report novel gum acacia (GA) based microgels composites for multifunctional biomedical application. High yield of spherical GA microgels particles within 5-50 µm size range was obtained via crosslinking the polymer in the reverse micelles of surfactant-sodium bis (2-ethylhexyl) sulfosuccinate (NBSS) in gasoline medium. The prepared microgels were then utilized for in situ silver (Ag) and cobalt (Co) nanoparticles (NPs) synthesis to subsequently produce GNAg and GNCo nanocomposite microgels, respectively. Ag and Co NPs of particle of almost less than 40 nm sizes were homogenously distributed over the matrices of the prepared microgels, and therefore, negligible agglomeration effect was observed. Pristine GA microgels, and the nanocomposite microgels were thoroughly characterized through FTIR, DSC, TGA, XRD, SEM, EDS, and TEM. The well-characterized pristine GA microgels and the nanocomposite microgels were then subjected to multiple in vitro bioassays including antioxidant, antidiabetic, and antimicrobial activities as well as biocompatibility investigation. Our results demonstrate that the prepared nanocomposites in particular GNAg microgels exhibited excellent biomedical properties as compared to pristine GA microgels. Among the prepared samples, GNAg nanocomposites were highly active against Fusarium oxysporum and Aspergillus niger that show 47.73% ± 0.25 inhibition and 32.3% ± 2.0 with IC-50 of 220 µg ml-1 and 343 µg ml-1 , respectively. Moderate antidiabetic activity was also observed for GNAg nanocomposites with considerable inhibition of 15.34% ± 0.20 and 14.7% ± 0.44 for both α-glucosidase and α-amylase, respectively. Moreover, excellent antioxidant properties were found for both the GNAg and GNCo nanocomposites as compared to pristine GA microgels. A remarkable biocompatible nature of the nanocomposites in particular GNAg makes the novel GA composites, to be exploited for diverse biomedical applications.


Asunto(s)
Nanopartículas del Metal , Microgeles , Nanocompuestos , Antibacterianos/farmacología , Fusarium , Goma Arábiga , Plata/farmacología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA