Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Cerebrovasc Endovasc Neurosurg ; 26(2): 223-226, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38528441

RESUMO

Percutaneous techniques for femoral arterial access are increasingly being performed due to advances in endovascular cerebral procedures, as they provide a less morbid and minimally invasive approach than open procedures. Common complications associated with this peripheral puncture include hematoma, bleeding, pseudoaneurysm, arteriovenous fistula, retroperitoneal bleeding, inadvertent venous puncture, dissection, etc. The retrograde femoral access is currently the most frequently used arterial access as it is technically straightforward, allows for the use of larger size sheaths and catheters, allows repeated attempts, etc. Although being technically less challenging, grave complications can occur due to hardware failure. Here, we present a case of unruptured posterior inferior cerebellar artery (PICA) aneurysm, who underwent uneventful diagnostic cerebral digital substraction angiography (DSA) via right femoral artery route on first attempt, but on second attempt for therapeutic intervention, landed up with stuck guide wire and faced decannulation difficulty due to unravelling of guide wire and multiple knot formation, which was finally removed after multiple attempts at pulling and improvised manoeuvres. Such cannulation and decannulation difficulties have been reported multiple times for central venous access, but extremely rarely for femoral routes, making this case a rarity and worth reporting.

3.
Surg Neurol Int ; 14: 327, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37810289

RESUMO

Background: Colloid cysts, common benign lesions of the third ventricle, have rarely been reported in uncommon extraventricular locations such as the pituitary fossa. Even in the sellar region, it is usually seen between the anterior and posterior pituitary lobes (pars intermedia). Case Description: Here, we report a case of a female patient, who was incidentally diagnosed with a sellar colloid cyst, while being evaluated for nonspecific holocranial headache. On imaging, there was a lesion located in the anterior sellar region, compressing the whole pituitary gland posteriorly (first reported case to the best of our knowledge), that was found to be a colloid cyst intraoperatively during microsurgical excision through transnasal transsphenoidal route. Conclusion: This rare entity should be kept in mind while considering lesions of the pituitary region, as evident by typical radiological features, in spite of being located in a less likely site.

4.
J Cerebrovasc Endovasc Neurosurg ; 25(4): 447-451, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37583079

RESUMO

Developmental anomalies of internal carotid artery (ICA), being rare entities, are mostly asymptomatic by themselves because of good collateral supply. However, when present with other associated intracranial anomalies requiring treatment, there can be catastrophic consequences, if special attention is not paid to this condition. We present a case of 36 years old male, who reported to our emergency department with complaints of headache and loss of consciousness. He was diagnosed as a case of ruptured anterior communicating aneurysm with subarachnoid hemorrhage and agenesis of left ICA with trans-cavernous anastomosis. He underwent clipping of aneurysm and was discharged uneventfully. This report highlights the importance of skillful microsurgical clipping in extremely high-risk conditions, in contemporary era of hybrid neurosurgeons.

5.
J Colloid Interface Sci ; 650(Pt B): 1619-1637, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37494859

RESUMO

Over time, the interest in developing stable photosensitizers (PS) which both absorb and emit light in the red region (650 and 950 nm) has gained noticeable interest. Recently, carbon dots (CDs) have become the material of focus to act as a PS due to their high extinction coefficient, low cytotoxicity, and both high photo and thermal stability. In this work, a Federal and Drug Association (FDA) approved Near Infra-Red (NIR) organic fluorophore used for photo-imaging, indocyanine green (ICG), has been explored as a precursor to develop water-soluble red emissive CDs which possess red emission at 697 nm. Furthermore, our material was found to yield favorable red-imaging capabilities of glioblastoma stem-like cells (GSCs) meanwhile boasting low toxicity. Additionally with post modifications, our CDs have been found to have selectivity towards tumors over healthy tissue as well as crossing the blood-brain barrier (BBB) in zebrafish models.


Assuntos
Glioblastoma , Pontos Quânticos , Animais , Carbono , Glioblastoma/diagnóstico por imagem , Peixe-Zebra , Corantes Fluorescentes
6.
Surg Neurol Int ; 14: 215, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37404502

RESUMO

Background: Encephalocele is herniation of cranial contents through a skull defect, classified according to their contents and location, and is usually seen in pediatric age group. The transsphenoidal type represents <5% of all basal meningoencephaloceles. Of them, the presentation in adulthood is even rarer. Case Description: A 19-year-old female complaining of breathing difficulties during sleep and exertional dyspnea was diagnosed with a transsphenoidal meningoencephalocele, likely representing patent craniopharyngeal canal. On exploration through bifrontal craniotomy, the defect was identified in the sellar floor after completely reducing the contents into the cranial cavity and was repaired. She had immediate symptomatic relief and an uneventful postoperative course. Conclusion: There can be significant symptomatic relief with minimal postoperative morbidity after transcranial repair of such large transsphenoidal meningoencephaloceles, through traditional skull base approaches.

7.
Molecules ; 28(4)2023 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-36838742

RESUMO

In this work, a NIR emitting dye, p-toluenesulfonate (IR-813) was explored as a model precursor to develop red emissive carbon dots (813-CD) with solvatochromic behavior with a red-shift observed with increasing solvent polarity. The 813-CDs produced had emission peaks at 610 and 698 nm, respectively, in water with blue shifts of emission as solvent polarity decreased. Subsequently, 813-CD was synthesized with increasing nitrogen content with polyethyleneimine (PEI) to elucidate the change in band gap energy. With increased nitrogen content, the CDs produced emissions as far as 776 nm. Additionally, a CD nanocomposite polyvinylpyrrolidone (PVP) film was synthesized to assess the phenomenon of solid-state fluorescence. Furthermore, the CDs were found to have electrochemical properties to be used as an additive doping agent for PVP film coatings.


Assuntos
Carbono , Pontos Quânticos , Solventes/química , Carbono/química , Pontos Quânticos/química , Corantes Fluorescentes/química , Nitrogênio/química
8.
Molecules ; 26(20)2021 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-34684750

RESUMO

The utilization of nanoparticles for a variety of applications has raised much interest in recent years as new knowledge has emerged in nanochemistry. New and diverse methods for synthesis, characterization, and application of these particles have been discovered with differing degrees of ease and reproducibility. Post-synthetic modification of nanoparticles is often a required step to facilitate their use in applications. The reaction conditions and chemical environment for the nanoparticle synthesis may not support or may conflict with further reactions. For this reason, it is beneficial to have phase transfer methods for nanoparticles to allow for their dispersion in a variety of solvents. Phase transfer methods are often limited in the types and sizes of particles that can be effectively dispersed in an immiscible solvent. Currently, general transfer methods for a wide variety of nanoparticles have not been identified. New routes for phase transfer allow for utilization of a larger range of particles in applications which were previously limited by solubility and reactivity issues. In this work, we will describe the fundamental methods for the phase transfer of metallic nanoparticles. We will look at the major problems and pitfalls of these methods. The applications of phase transfer will also be reviewed, mainly focusing on catalysis and drug delivery.

9.
Molecules ; 26(12)2021 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-34207751

RESUMO

In this review, we present an assessment of recent advances in alkyne functionalization reactions, classified according to different classes of recyclable catalysts. In this work, we have incorporated and reviewed the activity and selectivity of recyclable catalytic systems such as polysiloxane-encapsulated novel metal nanoparticle-based catalysts, silica-copper-supported nanocatalysts, graphitic carbon-supported nanocatalysts, metal organic framework (MOF) catalysts, porous organic framework (POP) catalysts, bio-material-supported catalysts, and metal/solvent free recyclable catalysts. In addition, several alkyne functionalization reactions have been elucidated to demonstrate the success and efficiency of recyclable catalysts. In addition, this review also provides the fundamental knowledge required for utilization of green catalysts, which can combine the advantageous features of both homogeneous (catalyst modulation) and heterogeneous (catalyst recycling) catalysis.

10.
Sex Reprod Health Matters ; 29(2): 2059898, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35486102

RESUMO

In this paper, we present the results of a qualitative study by a non-profit organisation implementing a community-based urban adolescent development programme. The study highlights the sexual and reproductive health and rights (SRHR) situation of marginalised young women in a developed state of India. Our findings, based on in-depth interviews with young women and frontline health providers, show that structural factors, such as economic and social stratifiers, gender norms and cultural beliefs, result in further marginalisation of young women. In turn, marginalisation adversely affects the realisation of SRHR through discriminatory practices around menstruation and lack of control in matters related to sexuality, contraception, pregnancy and safe abortion. Rights to the highest standards of sexual and reproductive health (SRH) care are compromised. Health system factors like providers' attitudes and knowledge, commodity supplies, and indifference to ensuring delivery of contraceptives and other services often result in unplanned pregnancies and affect the quality of young women's SRH care. Whatever information and support adolescents and young women get is from local community-based organisations. We conclude that structural determinants and violations of fundamental rights to education, equal opportunities and participation constitute a significant barrier to the enjoyment of SRHR by the marginalised young women in the study. Unless these are addressed, government policies and programmes to promote young people's SRHR will not benefit young women from disadvantaged communities. Partnership and complementarity between government programmes, adolescents and health rights civil society organisations are recommended to promote rights-based, equitable adolescent and youth-friendly services to this vulnerable population.


Assuntos
Saúde Reprodutiva , Direito à Saúde , Adolescente , Feminino , Acessibilidade aos Serviços de Saúde , Humanos , Índia , Gravidez , Direitos Sexuais e Reprodutivos , Populações Vulneráveis
12.
Molecules ; 23(8)2018 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-30060483

RESUMO

Amino-bridged gel polymer P1 was discovered to catalyze alkyne halo-functionalization in excellent yields, regioselectivity, functional group compatibility, and recyclability. We have observed that both aromatic and aliphatic alkynes can be converted to α,α-dihalogenated ketones in the presence of polymer P1 under metal-free conditions at room temperature within a short reaction time.


Assuntos
Alcinos/química , Cetonas/síntese química , Polímeros/química , Catálise , Halogenação , Cetonas/química , Estrutura Molecular , Reciclagem , Estereoisomerismo
13.
ACS Omega ; 3(9): 10974-10979, 2018 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31459207

RESUMO

In this publication, a copper acetate-mediated rhodanine polymerization reaction is examined. It is demonstrated that at room temperature, Cu(II) acetate complexes with rhodanine generate solid nanospheres, which, upon heating in a microwave, results in polyrhodanine core-shell nano- and microsphere particles. The structural analysis of the polyrhodanine nanosphere produced by this efficient microwave-initiated method was conducted by Fourier transform infrared spectroscopy, UV-vis spectroscopy, scanning electron microscopy, and transmission electron microscopy. In addition, it is verified that this template-free, efficient, and versatile synthesis of polyrhodanine nanospheres can also be accomplished by introducing a strong oxidant KMnO4 as a cocatalyst with copper acetate without compromising the morphology of the resulting core-shell nanospheres. It is also demonstrated that the polyrhodanine nanospheres can be used to adsorb methyl orange dye, a known contaminant in industrial wastewater.

14.
Dalton Trans ; 46(27): 8709-8715, 2017 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-28426075

RESUMO

A mild, selective and facile synthesis of vinylsilanes via a recyclable platinum nanoparticle catalysed hydrosilylation of alkynes is reported. Various functionalized alkynes are selectively hydrosilylated to furnish functional ß-E vinylsilanes in high yields. The catalytic effectiveness, ease of catalyst recovery and recyclability of the polysiloxane stabilized Pt-nanoparticle catalyst are the major achievements of this work. Detailed in situ characterization using Electron Microscopy and controlled poisoning experiments supports the participation of Pt-nanoparticles as active catalysts.

15.
J Vis Exp ; (108): e53507, 2016 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-26890450

RESUMO

In this work, a facile one-pot reaction for the formation of metal nanoparticles in a water solution through the use of n-(2-aminoethyl)-3-aminosilanetriol is presented. This compound can be used to effectively reduce and complex metal salts into metal core nanoparticles coated with the compound. By controlling the concentrations of salt and silane one is able to control reaction rates, particle size, and nanoparticle coating. The effects of these changes were characterized through transmission electron microscopy (TEM), UV-Vis spectrometry (UV-Vis), Nuclear Magnetic Resonance spectroscopy (NMR) and Fourier Transform Infrared spectroscopy (FTIR). A unique aspect to this reaction is that usually silanes hydrolyze and cross-link in water; however, in this system the silane is water-soluble and stable. It is known that silicon and amino moieties can form complexes with metal salts. The silicon is known to extend its coordination sphere to form penta- or hexa-coordinated species. Furthermore, the silanol group can undergo hydrolysis to form a Si-O-Si silica network, thereby transforming the metal nanoparticles into a functionalized nanocomposites.


Assuntos
Nanopartículas Metálicas/química , Nanocompostos/química , Tamanho da Partícula , Silanos/química , Dióxido de Silício/química , Espectroscopia de Ressonância Magnética , Nanopartículas Metálicas/ultraestrutura , Microscopia Eletrônica de Transmissão , Nanocompostos/ultraestrutura , Espectroscopia de Infravermelho com Transformada de Fourier
16.
J Am Chem Soc ; 127(16): 5790-1, 2005 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-15839668

RESUMO

The first example of "Pt"-nanocluster-catalyzed regioselective generation of hybrid polymers via attachment of organic functionalities to evenly distributed Si-H bonds of poly(methylhydro)siloxane is described. In addition, participation of Pt-nanoclusters as an active catalyst was evidenced by various spectroscopic techniques during the catalytic transformations.

17.
J Am Chem Soc ; 126(27): 8493-500, 2004 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-15238006

RESUMO

Polysiloxane-encapsulated "Pd"-nanoclusters were generated by reduction of Pd(OAc)(2) with polymethylhydrosiloxane, which functions as a reducing agent as well as a capping material for production and stabilization of catalytically active "Pd"-nanoparticles. Chemoselective hydrogenation of functional conjugated alkenes was achieved by in-situ- or ex-situ-generated polysiloxane-stabilized "Pd"-nanoclusters under mild reaction conditions in high yields. Electron microscopy, UV-vis, and NMR studies of the reaction mixture during the catalytic transformation were performed and, in conjunction with catalyst poisoning experiments, demonstrated unequivocally the role of polysiloxane-encapsulated "Pd"-nanoclusters as the real catalytic species. The recyclability of the "Pd"-nanoclusters was established by reusing the solid left after the reaction.

18.
J Am Chem Soc ; 125(10): 2876-7, 2003 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-12617645

RESUMO

The role of "Pd" colloids in Pd(OAc)2 -catalyzed silaesterification reactions was investigated. The first example of the generation and utilizations of recyclable polysiloxane network stabilized palladium nanoparticles is described. We also provide the evidence that the silicon polymers play the role of stabilizing agents, preventing the generation of bulk palladium without compromising the activity of the catalyst.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...