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1.
J Colloid Interface Sci ; 678(Pt B): 599-608, 2024 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-39265332

RESUMO

Direct methanol fuel cells rely on the efficiency of their anode/cathode electrocatalysts to facilitate the methanol oxidation reaction and oxygen reduction reaction, respectively. Platinum-based nanocatalysts are at the forefront due to their superior catalytic properties. However, the high-cost, scarcity, and low CO tolerance of platinum pose challenges for the scalable application of DMFCs. Herein, we report novel ultrathin ternary PtNiRu alloy nanowires to improve Pt utilization and CO tolerance. These novel electrocatalysts incorporate the oxophilic metal Ru into ultrathin PtNi nanowires, aiming to enhance the intrinsic activity of platinum while leveraging the long-term durability and high utilization efficiency provided by the bimetallic synergistic effect. The PtNiRu NWs significantly enhance both mass activity and specific activity for ORR, performing about 6.9 times and 3.9 times better than commercial Pt/C, respectively. After a rigorous durability test of 10,000 cycles, the PtNiRu NWs only exhibited a 25.2 % loss in mass activity. Additionally, for MOR, the MA and SA of PtNiRu NWs exceed that of Pt/C catalyst by 4.30 and 2.72 times, respectively, and exhibit exceptional resistance to CO poisoning. Theoretical insights from density functional theory calculations suggest that the introduction of Ru modulates the d-band center of the surface Pt atoms, which contributes to decreased binding strength of oxygenated species and an elevated dissolution potential, substantiating the enhanced performance metrics, and the durability enhancement stems from the stronger PtM bonds than those in PtNiRu NWs resulted from PtRu covalent interactions. These findings not only provide a new perspective on platinum-based nanocatalysts but also significantly advance the quest for more efficient and durable electrocatalysts for DMFCs, representing a substantial stride in fuel cell technology.

2.
Anal Methods ; 2024 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-39329181

RESUMO

Single-atom nanozymes (SAzymes) as a class of highly active nanozymes with the advantages of high atom utilization, high catalytic activity and stability have attracted great attention. In this work, Fe-N-C SAzymes with exceptional oxidase (OXD)-like activity were achieved utilizing polyvinylpyrrolidone (PVP) as a template. The Fe-N-C SAzymes with remarkable OXD-like activity could oxidize TMB to blue oxTMB, but 8-hydroxyquinoline (8-HQ) as a metal chelator is capable of discoloring oxTMB. Thus, the addition of 8-HQ decolorized the solution. However, upon the introduction of Cr(VI) ions, 8-HQ preferentially chelated with the Cr(VI) ions, reversing the inhibition of the color reaction and restoring the blue color. Based on this phenomenon, we constructed a novel paper-based analytical device (PAD) that exhibited a linear range of 5-1000 µM and an LOD of 1.2 µM. Importantly, the PAD used in this study shows the merits of simplicity, low preparation costs, and rapid reaction times. When combined with smartphone RGB analysis, it enables the simultaneous analysis of eight different Cr(VI) concentrations without the need for large-scale instrumentation. Moreover, the proposed PAD displays high selectivity, accuracy and utility in testing actual short-necked clam samples. This work not only provides a simple and cost-effective method to detect Cr(VI) but also makes a contribution to rapid food testing.

3.
J Hazard Mater ; 480: 135887, 2024 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-39305600

RESUMO

The rapid, precise, and high-throughput identification of multiple heavy metals ions holds immense importance in ensuring food safety and promoting public health. This study presents a novel smartphone-assisted colorimetric sensor array for the rapid and precise detection of multiple heavy metals ions. The sensor array is based on three signal recognition elements (AuPt@Fe-N-C, AuPt@N-C, and Fe-N-C) and the presence of different heavy metal ions affects the nanozymes-chromogenic substrate (TMB) catalytic color production, enabling the differentiation and quantification of various heavy metal ions. Combined with a smartphone-based RGB mode, the colorimetric sensor array can successfully identify five different heavy metal ions (Hg2+, Pb2+, Co2+, Cr6+, and Fe3+) as low as 0.5 µM and different ratios of binary and ternary mixed heavy metal ions in just 5 min. The sensor array successfully tested seawater and salmon samples with a total heavy metal content of 10 µM in the South China Sea (Haikou and Wenchang). Overall, this study highlights the potential of smartphone-assisted colorimetric sensor arrays for the rapid and precise detection of multiple heavy metal ions, which could significantly contribute to food safety and public health monitoring.

4.
Small ; : e2403878, 2024 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-39058210

RESUMO

Effective identification of multiple cariogenic bacteria in saliva samples is important for oral disease prevention and treatment. Here, a simple colorimetric sensor array is developed for the identification of cariogenic bacteria using single-atom nanozymes (SANs) assisted by machine learning. Interestingly, cariogenic bacteria can increase oxidase-like activity of iron (Fe)─nitrogen (N)─carbon (C) SANs by accelerating electron transfer, and inversely reduce the activity of Fe─N─C further reconstruction with urea. Through machine-learning-assisted sensor array, colorimetric responses are developed as "fingerprints" of cariogenic bacteria. Multiple cariogenic bacteria can be well distinguished by linear discriminant analysis and bacteria at different genera can also be distinguished by hierarchical cluster analysis. Furthermore, colorimetric sensor array has demonstrated excellent performance for the identification of mixed cariogenic bacteria in artificial saliva samples. In view of convenience, precise, and high-throughput discrimination, the developed colorimetric sensor array based on SANs assisted by machine learning, has great potential for the identification of oral cariogenic bacteria so as to serve for oral disease prevention and treatment.

5.
Microsc Res Tech ; 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-39007412

RESUMO

Herein we described the biofabrication of samarium oxide nanoparticles (HT-Sm2O3 NPs) by applying the aqueous fruit extract of Hyphaene thebaica was utilized as an eco-friendly chelating agent. The prepared NPs were subjected to various physicochemical properties and potential in biomedical applications. X-ray Diffraction (XRD) pattern revealed sharp peaks that corroborated with the Joint Committee on Powder Diffraction Standards (JCPDS) card no. 00-042-1464. Crystallite size obtained from Debye-Scherrer approximation and Williamson-Hall (W-H) plot was 28.73 and 69.3 nm, respectively. Optical bandgap was calculated by employing Kubelka-Munk (K-M) function and was found to be ~4.58 eV. Raman shift was observed at 121, 351, 424-, and 561 cm-1. Photoluminescence (PL) spectra revealed two major peaks positioned at 360 and 540 nm. The high-resolution transmission electron microscopy (HR-TEM) analysis of HT-Sm2O3 nanoparticles (NPs) showed that they predominantly have spherical to cuboidal shapes. Additionally, the selected area electron diffraction (SAED) pattern presented spotty rings, indicating a high level of crystallinity in these NPs. The potential nanomedicine applications were studied using diverse bioassays using different treatments. The antioxidant activity demonstrated 45.71% ± 1.13% inhibition at 1000 µg/mL. Brine shrimp lethality assay revealed the highest cytotoxicity of 46.67% ± 3.33% at 1000 µg/mL and LC50 value of 1081 µg/mL. HT-Sm2O3 NPs exhibited inhibition of angiogenesis (20.41% ± 1.18%) at of 1000 µg/mL. MTT assay results indicated that HT-Sm2O3 NPs exhibit inhibitory effects on cell lines. Specifically, these NPs showed an IC50 value of 104.6 µg/mL against 3T3 cells. Against MCF-7 cells, the NPs demonstrated an IC50 value of 413.25 µg/mL. Additionally, in the inhibition of acetylcholinesterase (AChE), the newly synthesized NPs showed an IC50 value of 320 µg/mL. The antidiabetic assessment through α-glucosidase and α-amylase inhibition assays revealed, an IC50 value of 380 µg/mL for α-glucosidase and 952 µg/mL for α-amylase was calculated. Overall, our study suggested that the Sm2O3 NPs possess moderate anticancer, cholinesterase inhibition, and antidiabetic potential, however, needs further assessment. RESEARCH HIGHLIGHTS: In this work, nano-samaria is synthesized using an eco-friendly and green approach. The nanoparticles were characterized using techniques such as Raman, HR-TEM, FTIR, DRS, XRD, and so on, and the applications were studied using multiple in vitro bioassays for Diabetes, Alzheimer, and Cancer. The nano-samaria revealed good potential for potential biomedical applications.

6.
Biomed Pharmacother ; 174: 116544, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38599058

RESUMO

The current study was designed to investigate the potential of a synthetic therapeutic agent for better management of pain and inflammation, exhibiting minimal to non-existent ulcerogenic effects. The effect of 1-(2-chlorobenzoyl)-3-(2,3-dichlorophenyl) thiourea was assessed through model systems of nociception and anti-inflammatory activities in mice. In addition, the ulcerogenic potential was evaluated in rats using the NSAID-induced pyloric ligation model, followed by histopathological and biochemical analysis. The test was conducted on eight groups of albino rats, comprising of group I (normal saline), groups II and III (aspirin® at doses of 100 mg/kg and 150 mg/kg, respectively), groups IV and V (indomethacin at doses of 100 mg/kg and 150 mg/kg, respectively), and groups VI, VII, and VIII (lead-compound at 15 mg/kg, 30 mg/kg and 45 mg/kg doses, respectively). Furthermore, molecular docking analyses were performed to predict potential molecular target site interactions. The results showed that the lead-compound, administered at doses of 15, 30, and 45 mg/kg, yielded significant reductions in chemically and thermally induced nociceptive pain, aligning with the levels observed for aspirin® and tramadol. The compound also effectively suppressed inflammatory response in the carrageenan-induced paw edema model. As for the ulcerogenic effects, the compound groups displayed no considerable alterations compared to the aspirin® and indomethacin groups, which displayed substantial increases in ulcer scores, total acidity, free acidity, and gastric juice volume, and a decrease in gastric juice pH. In conclusion, these findings suggest that our test compound exhibits potent antinociceptive, anti-inflammatory properties and is devoid of ulcerogenic effects.


Assuntos
Inflamação , Simulação de Acoplamento Molecular , Nociceptividade , Úlcera Gástrica , Tioureia , Animais , Úlcera Gástrica/induzido quimicamente , Úlcera Gástrica/patologia , Úlcera Gástrica/tratamento farmacológico , Tioureia/análogos & derivados , Tioureia/farmacologia , Masculino , Nociceptividade/efeitos dos fármacos , Camundongos , Inflamação/tratamento farmacológico , Inflamação/patologia , Ratos , Ratos Wistar , Analgésicos/farmacologia , Analgésicos/química , Anti-Inflamatórios não Esteroides/farmacologia , Anti-Inflamatórios não Esteroides/química , Simulação por Computador , Mucosa Gástrica/efeitos dos fármacos , Mucosa Gástrica/patologia , Mucosa Gástrica/metabolismo , Indometacina/farmacologia , Dor/tratamento farmacológico , Dor/induzido quimicamente , Dor/patologia , Anti-Inflamatórios/farmacologia
7.
Eur J Trauma Emerg Surg ; 50(3): 829-836, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38240790

RESUMO

OBJECTIVE: To present our experience of multidisciplinary management of high-grade pediatric liver injuries. INTRODUCTION: Pediatric high-grade liver injuries pose significant challenge to management due to associated morbidity and mortality. Emergency surgical intervention to control hemorrhage and biliary leak in these patients is usually suboptimal. Conservative management in selected high-grade liver injuries is now becoming standard of care. Management of hemobilia due to pseudoaneurysm formation and traumatic bile leaks requires multidisciplinary management. METHODS: A retrospective review was undertaken for patients presenting with blunt liver injuries at two tertiary care centers in Karachi, Pakistan, from March 2021 to December 2022. Twenty-eight patients were identified, and four patients fulfilled the criteria for grade 4 and above blunt liver injury during this period. RESULTS: One case with grade 4 liver injury developed hemobilia on 7th day of injury. He required two settings of angioembolization but had recurrent leak from pseudoaneurysm. He ultimately needed right hepatic artery ligation. Second patient presented with massive biliary peritonitis 2 days following injury. He was managed initially with tube laparostomy followed by ERCP and stent placement. The third patient developed large hemoperitoneum managed conservatively. One case with grade 5 injury expired during emergency surgery. CONCLUSION: Conservative management of advanced liver injuries can result in significant morbidity and mortality due to high risk of complications. Trauma surgeons need to have multidisciplinary team for management of these patients to gain optimal outcome.


Assuntos
Fígado , Ferimentos não Penetrantes , Humanos , Masculino , Estudos Retrospectivos , Ferimentos não Penetrantes/terapia , Ferimentos não Penetrantes/complicações , Criança , Fígado/lesões , Paquistão , Feminino , Embolização Terapêutica/métodos , Adolescente , Hemobilia/etiologia , Hemobilia/terapia , Equipe de Assistência ao Paciente , Pré-Escolar , Tratamento Conservador , Traumatismos Abdominais/terapia , Traumatismos Abdominais/complicações , Traumatismos Abdominais/cirurgia , Artéria Hepática/lesões , Escala de Gravidade do Ferimento
8.
Cureus ; 15(9): e45144, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37842457

RESUMO

INTRODUCTION: Anterior displacement of the anus (ADA) is recognized as a common congenital abnormality of the anorectal region and is often associated with constipation. It is diagnosed through a physical examination by measuring the Anal Position Index (API) at birth. METHODS: A cross-sectional study was conducted utilizing non-probability consecutive sampling of all patients presenting with ADA at our institute over a six-month period. The study focused on key variables, including the measurement of scroto-anal and scroto-coccygeal distances in boys and fourchette-anal and fourchette-coccygeal distances in girls. Data collection was carried out using a structured proforma, ensuring prospective data collection from neonates meeting the selection criteria (neonates born at our center and identified by the neonatology team as having a normal anal opening, regardless of their gestational period or birthweight). RESULTS: Our study comprised a cohort of 204 neonates. The Anal Position Index was determined to be 0.36 ± 0.07 for male newborns and 0.24 ± 0.06 for female newborns. Notably, a statistically significant correlation was observed between the API and factors such as gestational age, birth weight, and advancing paternal age. CONCLUSION: The assessment of the API proves highly valuable in identifying indicators of ADA in neonates, facilitating early disease detection, and guiding the prompt management of subsequent functional symptoms, such as constipation, during later stages of life.

9.
Urol Case Rep ; 50: 102509, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37560441

RESUMO

Penile Hair Tourniquet Syndrome, a subtype of Penile Tourniquet Syndrome, is a rare condition and a pediatric surgical emergency seen in infants whereby a constricting hair coil strangulates the penis most often at the coronal sulcus, leading to edema, ischemia and necrosis, If untreated, it can potentially lead to development of a urethrocutaneous fistula or even urethral transection and penile amputation. Therefore, a well-timed intervention can prevent complications and lifelong unhappiness. Herein, we present a case of an 11-month-old boy who presented with near total amputation of the glans and underwent two-staged repair with a satisfactory outcome.

10.
J Pak Med Assoc ; 73(5): 1069-1075, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37218235

RESUMO

Osteosarcoma is the commonest primary bone malignancy occurring in patients aged <20, and humerus is the third most common site affected by it. In the past, ablative surgery with poor functional outcomes was the only option, but due to advances in chemotherapy, medical imaging and surgical techniques, patient survivorship and the rate of limb salvage surgery has increased significantly. Over the decades many treatment options have been proposed for the reconstruction of the defect following extirpation of the tumour in the proximal humerus, with every procedure having its merits and demerits. However, there is no agreement on the preferred treatment even in similar age groups, and the best way to reconstruct the proximal humerus remains debatable because the restoration of the function of the shoulder girdle remains primarily dependant on the extent of muscle-loss during tumour resection, available surgical expertise and financial constraints in different health systems. The current narrative review was planned to discuss the various reconstruction techniques with their advantages and disadvantages, and a present general review of the relevant literature.


Assuntos
Neoplasias Ósseas , Osteossarcoma , Procedimentos de Cirurgia Plástica , Humanos , Ombro , Osteossarcoma/cirurgia , Osteossarcoma/patologia , Úmero/cirurgia , Salvamento de Membro/métodos , Neoplasias Ósseas/cirurgia , Neoplasias Ósseas/patologia , Resultado do Tratamento
12.
J Ayub Med Coll Abbottabad ; 34(Suppl 1)(3): S622-S626, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36414580

RESUMO

Background: The resurgence and long duration of treatment of the Ponseti method in recent years has been punctuated by less than favourable long-term outcomes for surgically treated feet. Objectives of the study were to compare the two treatment techniques accelerated vs standard Ponseti technique among children's having Congenital Talipes Equinovarus. Methods: This was two years randomized control trial study carried out among total 104 idiopathic congenital talipes equinovarus patients in Orthopaedics and Spine Unit, Hayatabad Medical Complex, Peshawar. A convenient sampling technique was used in this study. Informed written consent was taken from each respondent. Patients in group A was subjected to accelerated ponseti technique and patients in group B was subjected to standard ponseti technique. At one month after treatment, all the patients were re assessed on the basis of pirani score. Data was collected and analyzed using SPSS version 21. Results: This study included a total 104 clinically diagnosed Congenital Talipes Equinovarus patients with mean age 5.5±2.1 months and 52 in each treatment group. Out of total 104 patients 68 (65.4%) were male and 36 (34.6%) were female. They're found significant difference in the mean ponseti scores of these two-group p=0.042 provided comparatively low mean pirani score in accelerated ponseti group. All female child in accelerated ponsati group was responded to the treatment with 100% effectiveness rate. The difference of effectiveness of treatment was significant p=0.015 for children age range 4-8 months divided in two treatment group with good effectiveness 80.8% in accelerated ponseti group. Conclusion: Accelerated ponseti technique is more effective than standard ponseti technique for Congenital Talipes Equinovarus.


Assuntos
Pé Torto Equinovaro , Procedimentos Ortopédicos , Criança , Humanos , Masculino , Feminino , Lactente , Pé Torto Equinovaro/cirurgia , Moldes Cirúrgicos , Procedimentos Ortopédicos/métodos , Fatores de Tempo , Coluna Vertebral
13.
Traffic Inj Prev ; 23(6): 333-338, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35639637

RESUMO

OBJECTIVES: On-demand ridesharing services are suggested to provide several benefits, such as improving accessibility and mobility, reducing drive-alone trips and greenhouse gas emissions. However, the impacts of these services on traffic crashes are not completely clear. This paper investigates the availability of Via- an on-demand ridesharing service in Arlington, TX, to identify the effects of this service on traffic crashes. We hypothesize that the launch of Via would result in more shared rides, fewer drive-alone trips and fewer traffic crashes. METHODS: We implement an Interrupted Time Series Analysis (ITSA) approach to study the impact of Via service availability on traffic crashes using weekly counts of all traffic crashes, the number of injuries, and serious injuries that occurred in Arlington from 2014 to 2021. RESULTS: The results show a statistically significant reduction in the weekly number of total crashes and total injuries but do not show any significant impact on the number of serious injuries. Shared Autonomous Vehicles have the potential to reduce traffic crashes caused by driver's fault. CONCLUSIONS: This study reveals the potential impacts ridesharing services can have on traffic crashes and injuries in a mid-sized city. The results of this study can help decision and policymakers to understand the full potential of ridesharing services that can contribute to making relevant decisions toward creating sustainable and safer transportation systems in cities.


Assuntos
Acidentes de Trânsito , Projetos de Pesquisa , Acidentes de Trânsito/prevenção & controle , Cidades , Humanos , Análise de Séries Temporais Interrompida , Fatores de Tempo
14.
Sens Biosensing Res ; 36: 100482, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35251937

RESUMO

The discovery of SARS-CoV-2 virus in the water bodies has been reported, and the risk of virus transmission to human via the water route due to poor wastewater management cannot be disregarded. The main source of the virus in water bodies is the sewage network systems which connects to the surface water. Wastewater-based epidemiology has been applied as an early surveillance tool to sense SARS-CoV-2 virus in the sewage network. This review discussed possible transmission routes of the SARS-CoV-2 virus and the challenges of the existing method in detecting the virus in wastewater. One significant challenge for the detection of the virus is that the high virus loading is diluted by the sheer volume of the wastewater. Hence, virus preconcentration from water samples prior to the application of virus assay is essential to accurately detect traceable virus loading. The preparation time, materials and conditions, virus type, recovery percentage, and various virus recovery techniques are comprehensively discussed in this review. The practicability of molecular methods such as Polymer-Chain-Reaction (PCR) for the detection of SARS-CoV-2 in wastewater will be revealed. The conventional virus detection techniques have several shortcomings and the potential of biosensors as an alternative is also considered. Biosensing techniques have also been proposed as an alternative to PCR and have reported detection limits of 10 pg/µl. This review serves to guide the reader on the future designs and development of highly sensitive, robust and, cost effective SARS-CoV-2 lab-on-a-chip biosensors for use in complex wastewater.

15.
Biosens Bioelectron ; 205: 114097, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35219019

RESUMO

Machine learning algorithms as a powerful tool can efficiently utilize and process large quantities of data generated by high-throughput experiments in various fields. In this work, we used a general ionic salt-assisted synthesis method to prepare oxidase-like Fe-N-C SANs. The possible reason for the excellent enzyme-mimicking activity and affinity of Fe-N-C SANs was further verified by density functional theory calculations. Due to the remarkable oxidase-mimicking activity, the prepared Fe-N-C SANs were used to detect ascorbic acid (AA) with a detection limit of 0.5 µM. Based on the machine learning algorithms, we successfully distinguished six antioxidants (ascorbic acid, glutathione, L-cysteine, dithiothreitol, uric acid, and dopamine) with the same concentration by either one kind of Fe-N-C SANs or three kinds of different Fe-N-C SANs. The usefulness of the Fe-N-C SANs sensor arrays was further validated by the hierarchal cluster analysis, where they also can be correctly identified. More importantly, a SANs-based digital-image colorimetric sensor array has also been successfully constructed and thereby achieved visual and informative colorimetric analysis for practical samples out of the lab. This work not only provides a design synthesis method to prepare SANs but also combines machine learning algorithms with SANs sensors to identify analytes with similar properties, which can further expand to the detection of proteins and cells related to diseases in the future.


Assuntos
Antioxidantes , Técnicas Biossensoriais , Ácido Ascórbico , Colorimetria , Glutationa
16.
Molecules ; 26(9)2021 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-34064537

RESUMO

In this work, advanced nanoscale surface characterization of CuO Nanoflowers synthesized by controlled hydrothermal approach for significant enhancement of catalytic properties has been investigated. The CuO nanoflower samples were characterized by field-emission scanning electron microscopy (FE-SEM), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, high-resolution transmission electron microscopy (HR-TEM), selected-area electron diffraction (SAED), high-angular annular dark field scanning transmission electron microscopy (HAADF-STEM) with elemental mapping, energy dispersive spectroscopy (STEM-EDS) and UV-Vis spectroscopy techniques. The nanoscale analysis of the surface study of monodispersed individual CuO nanoflower confirmed the fine crystalline shaped morphology composed of ultrathin leaves, monoclinic structure and purified phase. The result of HR-TEM shows that the length of one ultrathin leaf of copper oxide nanoflower is about ~650-700 nm, base is about ~300.77 ± 30 nm and the average thickness of the tip of individual ultrathin leaf of copper oxide nanoflower is about ~10 ± 2 nm. Enhanced absorption of visible light ~850 nm and larger value of band gap energy (1.68 eV) have further supported that the as-grown material (CuO nanoflowers) is an active and well-designed surface morphology at the nanoscale level. Furthermore, significant enhancement of catalytic properties of copper oxide nanoflowers in the presence of H2O2 for the degradation of methylene blue (MB) with efficiency ~96.7% after 170 min was obtained. The results showed that the superb catalytic performance of well-fabricated CuO nanoflowers can open a new way for substantial applications of dye removal from wastewater and environment fields.

17.
Mater Sci Eng C Mater Biol Appl ; 116: 111278, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32806276

RESUMO

A novel and simple strategy was designed for the synthesis of an unmodified gum arabic (GA) and acrylic acid (AA) based polymer hydrogels using Fe3+ as a physical cross-linking agent. The hydrogels showed a high mechanical strength, self-sustainability and self-healing ability, which depends on the content of GA and Fe3+ in the composition. The fracture stress increased from 0.23 to 0.841 MPa and a decrease in self-healing from 53 to 34% was observed by increasing the GA amount from 12 to 50% respectively. The self-healing performance of the hydrogels enhanced with the existence of the Fe3+ amount on the interface. Therefore, the 3% addition of Fe3+, increased the self-healing ability of up to 70%. Furthermore, the hydrogels also showed an excellent fatigue resistance up to 20 cycles without any rapture and can beard a load of 2.5 kg for a very long time. After 4 min of resting time, the percent recovery in dissipated energy reaching a high value of 95%, indicating the excellent fatigue resistance performance of the hydrogels. The hydrogels contain 3-5% of water at normal conditions and confirm its environmental stability. This work provides a new direction for the synthesis of unmodified GA based physically cross-linked polymer hydrogels systems and can be applied in bioengineering and robotic science in the future.


Assuntos
Goma Arábica , Hidrogéis , Acrilatos , Polímeros
18.
Nanomaterials (Basel) ; 10(7)2020 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-32630689

RESUMO

In the present work, a facile one-step hydrothermal synthesis of well-defined stabilized CuO nanopetals and its surface study by advanced nanocharacterization techniques for enhanced optical and catalytic properties has been investigated. Characterization by Transmission electron microscopy (TEM) analysis confirmed existence of high crystalline CuO nanopetals with average length and diameter of 1611.96 nm and 650.50 nm, respectively. The nanopetals are monodispersed with a large surface area, controlled morphology, and demonstrate the nanocrystalline nature with a monoclinic structure. The phase purity of the as-synthesized sample was confirmed by Raman spectroscopy and X-ray diffraction (XRD) patterns. A significantly wide absorption up to 800 nm and increased band gap were observed in CuO nanopetals. The valance band (VB) and conduction band (CB) positions at CuO surface are measured to be of +0.7 and -1.03 eV, respectively, using X-ray photoelectron spectroscopy (XPS), which would be very promising for efficient catalytic properties. Furthermore, the obtained CuO nanopetals in the presence of hydrogen peroxide ( H 2 O 2 ) achieved excellent catalytic activities for degradation of methylene blue (MB) under dark, with degradation rate > 99% after 90 min, which is significantly higher than reported in the literature. The enhanced catalytic activity was referred to the controlled morphology of monodispersed CuO nanopetals, co-operative role of H 2 O 2 and energy band structure. This work contributes to a new approach for extensive application opportunities in environmental improvement.

19.
J Pak Med Assoc ; 70(4): 776-779, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32296238

RESUMO

Haemangioendotheliomas (HAE), although rare but are the most common parotid gland tumours in children. We report a 4-month-old girl who presented with a progressively enlarging right sided facial swelling overlying the angle of the mandible. An Ultrasound of the lesion and a computed tomography (CT) scan of the head and neck was carried out which revealed a large lesion within the right parotid gland. CT scan further demonstrated a direct communication with the right external carotid artery and external jugular vein. Considering the clinical course and radiological findings, there was sufficient evidence to avoid any invasive testing. Due to the self-limiting nature of the disease, patient was managed expectantly.


Assuntos
Hemangioendotelioma/diagnóstico por imagem , Neoplasias Parotídeas/diagnóstico por imagem , Feminino , Humanos , Lactente , Tomografia Computadorizada por Raios X , Ultrassonografia
20.
J Pak Med Assoc ; 70(12(A)): 2244-2246, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33475605

RESUMO

A retrospective chart review was carried out in children (neonates to 18 years) who underwent acute surgical abdominal exploration during 2012-2016 at the Aga Khan University Hospital, Karachi, to evaluate the postoperative surgical site infection rates in emergency paediatric abdominal surgery. Incidence of surgical site infection (SSI) was estimated. P-value was calculated, chisquare and non-parametric tests were performed by comparing pre-surgical and post-surgical procedure pathogen occurrence and pre-procedure wound status. Pathogen occurrence related to time-trend of 98 paediatric patients who underwent emergency abdominal surgery was plotted. Of the 94 who were discharged in stable condition, it was found that there was no significant difference between pre- and postsurgical pathogens. Escherichia coli (n=10) was found to be the most common pathogen. Contaminated wounds were associated with higher SSI (p=0.036, OR 1.95 95% CI 0.7-5.4). The study found that pre-surgery wound status could be an indicator for risk of SSI in a post-operative scenario.


Assuntos
Infecção da Ferida Cirúrgica , Criança , Humanos , Incidência , Recém-Nascido , Paquistão/epidemiologia , Estudos Retrospectivos , Fatores de Risco , Infecção da Ferida Cirúrgica/epidemiologia , Centros de Atenção Terciária
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