Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros








Base de dados
Assunto principal
Intervalo de ano de publicação
1.
Interface Focus ; 14(3): 20230066, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-39257631

RESUMO

This study presents a novel hierarchical nested honeycomb drawing inspiration from the hierarchical structures found in energy-absorbing citrus peels. Our investigation reveals that integrating secondary hierarchical units into primary honeycomb cells results in energy absorption profiles featuring two distinct plateaus. Notably, we found that these profiles can be finely tuned by adjusting the thickness of primary and secondary cell walls. Additionally, our study demonstrates a strategic removal of cell walls at key positions, reducing material consumption without compromising specific energy absorption. By establishing comprehensive structure-property relationships, we offer valuable insights into the design and optimization of hierarchical cellular materials. Compared with traditional honeycomb structures, the nested honeycomb structure shows a twofold increase in compressive strength and a fivefold increase in specific energy absorption, positioning them as promising candidates for applications requiring two-step impact protection and tunable performance, ranging from packaging to high-speed automobiles.

2.
Indian J Otolaryngol Head Neck Surg ; 75(4): 4071-4074, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37974689

RESUMO

Hemangioma of the paranasal sinus is an infrequent condition. Two types of hemangioma are present at the nose; cavernous and capillary. Capillary hemangioma is rare in the sinonasal tract. Patients presented with massive epistaxis should think of nasal hemangioma. Resuscitation of patients is important and urgent Computerized Tomography scans should be performed which will help character and extension of any mass present at the nasal cavity. Initial nasal packing may help to prevent bleeding. We report a case of capillary hemangioma of a 30-year lady present with massive epistaxis initially controlled by Nasal packing. Her CT scan shows a homogenous mass at left maxillary sinuses and underwent left endoscopic sphenopalatine artery ligation and removal of the mass. Supplementary Information: The online version contains supplementary material available at 10.1007/s12070-023-04046-z.

3.
Acta Biomater ; 138: 430-442, 2022 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-34728425

RESUMO

Be it animals or plants, most of the organism's offspring come into existence after their embryos develop inside a protective shell. In plants, these hard protective shells are called endocarps. They serve the function of nourishing and protecting the seeds from external mechanical damage. Through evolution, endocarps of plants have developed various structural strategies to protect the enclosed seeds from external threats, and these strategies can vary according to the habitat or lifestyle of a particular plant. One such intriguing hard plant shell is the endocarp of the Elaeocarpus ganitrus fruit. It mostly grows in South Asia's mountainous forests, and its endocarps are known in the local communities as unbreakable and everlasting prayer beads. We report an in-depth investigation on microstructure, tomography, and mechanical properties to cast light on its performance and the underlying structure-property relation. The 3D structural quantifications by micro-CT demonstrate that the endocarp has gradient microarchitecture. In addition, the endocarp also exhibits gradient hardness and stiffness. The toughening mechanisms arising from the layered cellular structure enable the endocarps to withstand higher loads up to 5000 N before they fracture. Our findings provide experimental evidence of outstanding fracture tolerance and seed protection strategies developed by Elaeocarpus ganitrus endocarp that encourage the design of synthetic fracture tolerant structures. STATEMENT OF SIGNIFICANCE: Endocarps are low-density plant shells that exhibit remarkable fracture resistance and energy absorption when they encounter impact by falling from high trees and prolonged compression and abrasion by the predators. Such outstanding mechanical performance originates through structural design strategies developed to protect their seeds. Here we demonstrate previously undiscovered structural features and mechanical properties of Elaeocarpus ganitrus endocarp. We scrutinize the microstructure using high-resolution x-ray tomography scans and the 3D structural quantifications reveal a gradient microstructure which is in agreement with the gradient hardness and stiffness. The multiscale hierarchical structures combined with the gradient motif yield impressive fracture tolerance in Elaeocarpus ganitrus endocarp. These findings advance the knowledge of the structure-property relation in hard plant shells, and the procured structural design strategies can be utilized to design fracture-resistant structures.


Assuntos
Elaeocarpaceae , Animais
4.
Neurol Res Int ; 2019: 3867946, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31275647

RESUMO

INTRODUCTION: Guillain-Barre syndrome is the most common cause of acute flaccid paralysis in the adult population. It occurs at the rate of 0.34 to 4 per 100000 individuals. This study was conducted to determine the clinicoepidemiological profile and outcome of the patients with Guillain-Barre syndrome. MATERIALS AND METHODS: We conducted a retrospective study of patients with Guillain-Barre syndrome, presented at B.P. Koirala Institute of Health Sciences, a tertiary care centre in eastern Nepal, from January 2013 to December 2017. All patients diagnosed with Guillain-Barre syndrome were included in this study. The handwritten case record files of the study population were retrieved from medical record section of the institute. RESULTS: Of 31 patients with Guillain-Barre syndrome, the mean age of patients was 17±12 years. The most common presenting symptom of study population was ascending paralysis (93.5%). Respiratory failure requiring mechanical ventilation occurred in 16.1%. The common variants are AIDP and AMAN. Respiratory tract infection (29%) was the most common antecedent event. The in-hospital mortality of Guillain-Barre syndrome was 6.45%. CONCLUSION: Guillain-Barre syndrome is commonly seen in the young population. The most common symptom of Guillain-Barre syndrome was ascending paralysis. The in-hospital mortality rate of patients with GBS was 6.45%.

5.
Indian J Crit Care Med ; 20(7): 417-20, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27555697

RESUMO

AIM: C-reactive protein (CRP) is a commonly used biomarker of sepsis, the leading cause of mortality in Intensive Care Units (ICUs). However, sufficient data are still lacking to strongly recommend it in clinical practice. The present study is aimed to find out its reliability in diagnosing sepsis. MATERIALS AND METHODS: CRP was measured in ICU-admitted patients with systemic inflammatory response syndrome and compared using a cutoff of 50 mg/L with the gold standard for diagnosing sepsis, taken as isolation of organism from a suspected source of infection or the Centers for Disease Control criteria for clinical sepsis. RESULTS: CRP had a sensitivity and specificity of 84.3% and 46.15%, respectively. Area under the receiver operating characteristics curve was calculated to be 0.683 (±0.153, P < 0.05). The cutoff value with the best diagnostic accuracy was found to be 61 mg/L. CONCLUSION: CRP is a sensitive marker of sepsis, but it is not specific.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA