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1.
Molecules ; 29(11)2024 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-38893494

RESUMO

Syzgium cumini (L.) Skeels powder (S. cumini powder), also known as Jamun, is well-known for its various medical and health benefits. It is especially recognized for its antidiabetic and antioxidant properties. Thus, S. cumini powder is used in various industries, such as the food and cosmetic industries. In this work, the fruit of S. cumini was utilized; its seeds were extracted, dried, and ground into powder. The ground powders were subjected to various techniques such as physicochemical tests, Fourier transform infrared (FTIR) spectroscopy, X-ray diffractometry (XRD), particle size analysis, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and antioxidant analysis. From the physicochemical tests, it was revealed that the jamun seed filler contained cellulose (43.28%), hemicellulose (19.88%), lignin (23.28%), pectin (12.58%), and wax (0.98%). The FTIR analysis supported these results. For instance, a peak at 2889 cm-1 was observed and associated with CH stretching, typically found in methyl and methylene groups, characteristic of cellulose and hemicellulose structures. The XRD results demonstrated that the crystallinity index of the jamun seed filler was 42.63%. The particle analysis indicated that the mean (average) particle size was 25.34 µm. This observation was ensured with SEM results. The EDX spectrum results showed the elemental composition of the fillers. Regarding thermal degradation, the jamun seed filler had the ability to withstand temperatures of up to 316.5 °C. Furthermore, endothermic and exothermic peaks were observed at 305 °C and 400 °C, respectively. Furthermore, the antioxidant property of the powder displayed a peak scavenging activity of 91.4%. This comprehensive study not only underscores the viability of S. cumini powder as a sustainable and effective particulate filler in polymer composites but also demonstrates its potential to enhance the mechanical properties of composites, thereby offering significant implications for the development of eco-friendly materials in various industrial applications.

2.
Molecules ; 27(22)2022 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-36432134

RESUMO

Recently, considerable interest has been focused on developing greener and biodegradable materials due to growing environmental concerns. Owing to their low cost, biodegradability, and good mechanical properties, plant fibers have substituted synthetic fibers in the preparation of composites. However, the poor interfacial adhesion due to the hydrophilic nature and high-water absorption limits the use of plant fibers as a reinforcing agent in polymer matrices. The hydrophilic nature of the plant fibers can be overcome by chemical treatments. Cellulose the most abundant natural polymer obtained from sources such as plants, wood, and bacteria has gained wider attention these days. Different methods, such as mechanical, chemical, and chemical treatments in combination with mechanical treatments, have been adopted by researchers for the extraction of cellulose from plants, bacteria, algae, etc. Cellulose nanocrystals (CNC), cellulose nanofibrils (CNF), and microcrystalline cellulose (MCC) have been extracted and used for different applications such as food packaging, water purification, drug delivery, and in composites. In this review, updated information on the methods of isolation of nanocellulose, classification, characterization, and application of nanocellulose has been highlighted. The characteristics and the current status of cellulose-based fiber-reinforced polymer composites in the industry have also been discussed in detail.


Assuntos
Celulose , Nanopartículas , Celulose/química , Tecnologia , Nanopartículas/química , Embalagem de Alimentos , Fenômenos Químicos
3.
Biomater Adv ; 162: 213921, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38870740

RESUMO

Eco-friendly nanotechnology-enabled biopolymers are one of the novel concepts of packaging materials to substitute traditional synthetic polymers and their composites. This article succinctly reviews the recent developments of introducing additional functionalities to biopolymers using metal and metal oxide nanoparticles. The functionality of metal nanoparticles such as silver, zinc oxide, titanium dioxide, copper oxide, gold, and magnesium oxide, as food packaging materials were discussed. The addition of nanoparticles in biopolymers improves mechanical properties, gas barrier properties, durability, temperature stability, moisture stability, antimicrobial activity, antioxidant property, and UV absorbance and can prevent the presence of ethylene and oxygen, hence extending the shelf life of foodstuffs. Other than this, the functional activity of these biopolymer composite films helps them to act like smart or intelligent packaging. The selection of metal nanoparticles, particle migration, toxicological effect, and potential future scope in the food packaging industry are also reviewed.


Assuntos
Embalagem de Alimentos , Nanopartículas Metálicas , Embalagem de Alimentos/métodos , Biopolímeros/química , Nanopartículas Metálicas/química , Nanocompostos/química , Humanos , Antioxidantes/química , Antioxidantes/farmacologia
4.
Artigo em Inglês | MEDLINE | ID: mdl-36541667

RESUMO

Summary: The spectrum of endocrine-related complications of COVID-19 infection is expanding; one of the most concerning of which is adrenal haemorrhage due to the risk of catastrophic adrenal crisis. In this study, we present a case that highlights the challenging management of a large, indeterminate unilateral adrenal mass during pregnancy and draws attention to a rare yet probably underestimated complication of COVID-19. During hospitalization for severe COVID-19 pneumonia, a 26-year-old woman was incidentally found to have a 12.5 cm heterogeneous left adrenal mass. Soon after the discovery, she became pregnant and upon referral, she was in the seventh week of gestation, without clinical or biochemical features of hormonal excess. The uncertainty of the diagnosis and the risks of malignancy and surgical intervention were discussed with the patient, and a period of radiological surveillance was agreed upon. An MRI scan performed 3 months later showed a size reduction of the adrenal lesion to 7.9 cm, which was against malignancy. A Doppler ultrasound showed a non-vascular, well-defined round lesion consistent with an adrenal haematoma, likely a complication of the recent COVID-19 infection. The multidisciplinary team recommended further radiological follow-up. The patient then spontaneously had miscarriage at 12 weeks gestation. Subsequent radiological surveillance showed a further size reduction of the adrenal lesion to 5.5 cm. The patient conceived again during follow-up, and the repeated Doppler ultrasound showed stable appearances of the adrenal mass, and thus, it was agreed to continue radiological monitoring after delivery. The pregnancy was uneventful, and the patient delivered a healthy baby. An MRI scan performed after delivery showed a stable but persistent lesion consistent with a likely underlying adrenal lesion. Learning points: Unilateral adrenal haemorrhage can occur as a complication of COVID-19 and should be considered in the differential diagnosis of heterogeneous adrenal masses if there is a history of recent infection. Management of large indeterminate adrenal masses during pregnancy poses several challenges and should be led by an experienced multidisciplinary team. Underlying adrenal tumours may trigger non-traumatic haemorrhages, especially if exacerbated by stressful illness.

5.
Cureus ; 12(8): e10155, 2020 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-32905188

RESUMO

Introduction Primary hyperparathyroidism is a common endocrine condition requiring parathyroidectomy for curative management. Localization of parathyroid gland by ultrasound and Tc99m-SESTAMIBI is important to opt for less invasive and comparatively lower complication risk surgery minimal invasive parathyroidectomy (MIP) instead of four-gland exploration surgery. Aim To evaluate ultrasound and Tc99m-SESTAMIBI in localization of abnormal parathyroid gland before surgery. Method and materials All patients of primary hyperparathyroidism (PHPT) that presented to a secondary care hospital (endocrinology department) from 2015-2019 were recruited retrospectively from electronic fusion system of hospital. Results of ultrasound parathyroid and Tc99m-SESTAMIBI done for localization of abnormal parathyroid gland were analyzed. Results Total PHPT patients recruited were 59, mean age 64.2 years, male 11 (18.64%) and female 48 (81.3%). Ultrasound parathyroid was done in 44 patients, Tc 99m-SESTAMIBI was done in 31, both tests were done in 31 patients. Combined concordant adenoma in both tests was seen in 11 (35%) cases which can opt for minimal invasive parathyroidectomy (MIP) with confidence whereas 65% of cases would require either four-gland exploration or further testing like single-photon emission computed tomography-computed tomography (SPECT-CT) or intraoperative parathyroid hormone measurement to opt for MIP. Conclusion Combined ultrasound parathyroid and Tc 99m-SESTAMIBI scan was useful in localization of parathyroid adenoma in 11 (35%) patients that can opt for MIP which is a lower complication risk surgery whereas 20 (65%) patients would need further investigation with SPECT-CT or intraoperative parathyroid hormone measurement or four-gland exploration surgery. Recommendation Third modality of investigation such as SPECT-CT or intraoperative parathyroid hormone measurement needs evaluation so that more patients can benefit from MIP instead of four-gland exploration surgery.

6.
Int J Biol Macromol ; 140: 637-646, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31437507

RESUMO

This work focuses on the fabrication of hybrid bio-composites using green epoxy as the matrix material, hemp (H) and sisal (S) fibre mats as the reinforcements. The hybrid composite with sisal/hemp fibres were fabricated by cost effective hand lay-up technique, followed by hot press with different stacking sequences. Static properties of the composites such as tensile, compressive, inter-laminar shear strengths (ILSS) and hardness were examined. The physical properties such as density, void content, water absorption and thickness swelling were also analyzed. The experimental results indicate that hybrid composites exhibited minor variation in tensile strength when the stacking sequence was altered. The hybrid composite with the intercalated arrangement (HSHS) exhibited the highest tensile modulus when compared with the other hybrid counterparts. Hybrid composites (SHHS and HSSH) offered 40% higher values of compressive strength than the other layering arrangements. HHHH sample exhibited the highest ILSS value of 4.08 MPa. Typical failure characteristics of the short beam test such as inter-laminar shear cracks in the transverse direction, micro-buckling and fibre rupture were also observed.


Assuntos
Cannabis/química , Resinas Epóxi/química , Força Compressiva , Dureza , Teste de Materiais/métodos , Pressão , Resistência ao Cisalhamento , Resistência à Tração , Água/química
7.
Int J Biol Macromol ; 141: 1-13, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31472211

RESUMO

Bio-composites are easy to manufacture and environmentally friendly, could reduce the overall cost and provide lightweight due to the low density of the natural fibers. In a bid to compete with the synthetic fiber reinforced composites, a single natural fiber composite may not be a good choice to obtain optimal properties. Hence, hybrid composites are produced by adding two or more natural fibers together to obtain improved properties, such as mechanical, physical, thermal, water absorption, acoustic and dynamic, among others. Regarding thermal stability, the composites showed a significant change by varying the individual fiber compositions, fiber surface treatments, addition of fillers and coupling agents. The glass transition temperature and melting point obtained from the thermomechanical analysis and differential scanning calorimetry are not the same values for several hybrid composites, since the volume variation was not always parallel with the enthalpy change. However, the difference between the temperature calculated from the thermomechanical analysis and differential scanning calorimetry was lower. Significantly, this critical reviewed study has a potential of guiding all composite designers, manufacturers and users on right selection of composite materials for thermal applications, such as engine components (covers), heat shields and brake ducts, among others.


Assuntos
Celulose/química , Vidro/química , Teste de Materiais , Estresse Mecânico , Resistência à Tração
8.
Eur J Case Rep Intern Med ; 5(1): 000713, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30755972

RESUMO

This case demonstrates the therapeutic challenges encountered when managing an acute pulmonary embolism in a cancer patient with thrombocytopenia. A 64-year-old man with a history of lung cancer receiving chemotherapy was admitted to Walsall Manor Hospital with haemodynamic instability consistent with a pulmonary embolism, proven on computed tomographic pulmonary angiogram. His platelet count was noted to be 35×109/l (chemotherapy-induced thrombocytopenia). After discussions, he was deemed not suitable for thrombolysis based on risk versus benefits. The patient was initially transfused one adult dose of platelets and treated with half the therapeutic dose of low molecular weight heparin (LMWH). The same management plan was followed until the platelet count exceeded 50×109/l, after which the patient was established on the full therapeutic dose of LMWH. Clinically, the patient improved and was discharged. Three months after discharge, follow-up revealed sustained clinical improvement while the patient continued to be on the full therapeutic dose of LMWH with a stable platelet count. LEARNING POINTS: Cancer patients have a three-fold higher risk of venous thromboembolism compared with non-cancer patients, but also a higher risk of bleeding, hence neoplasm is considered an absolute contraindication to thrombolysis by the European Society of Cardiologists.The management of an acute pulmonary embolism in cancer patients with thrombocytopenia is still debated. However, a few recognised medical societies and expert opinions have established recommendations on this specific area, such as the British Committee for Standards in Haematology, the American Society of Clinical Oncology and the International Society of Thrombosis and Haemostasis.Expert opinion agrees on: giving the full therapeutic dose of low molecular weight heparin (LMWH) if the platelet count is above 50×109/l; if it drops below 50×109/l, halving the dose of LMWH with or without platelet transfusion until the platelet count improves above 50×109/l; and when the platelet count is below 20-30×109/l, withholding anticoagulation and considering the insertion of an inferior vena cava filter.

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