Investigation of ozone treatment on mechanical behavior of oriented carbon nanotube/epoxy nanocomposites

With the discovery of spectacular mechanical properties of carbon nanotubes (CNTs), CNTs became one of the most important reinforcement materials for composite materials. Many polymer-CNT combinations have been studied for various applications. Although, composition of an epoxy as matrix material and vertically aligned carbon nanotubes (VA-CNTs) as reinforcement is the best candidate for structural components. In this study, VA-CNTs for nanocomposite applications have been synthesized by catalytic chemical vapor deposition (CCVD) technique, and parameters such as catalyst structure and process recipe have been optimized to improve quality of VA-CNTs for further steps. To determine the quality of VA-CNTs, graphitization level, oxidation temperature, purity and morphology of CNTs have been measured. For purity and oxidation temperature tests, thermogravimetric analysis (TGA); for graphitization level measurements, RAMAN spectroscopy; for morphological analysis, scanning electron microscopy (SEM) have been employed. After synthesis and characterization steps, VA-CNTs have been treated with ozone to increase interaction between epoxy and CNTs. This interaction has been measured with contact angle measurements. Then, epoxy/CNT nanocomposites have been produced and mechanical performances have been tested to compare direct effect of ozone treatment on the mechanical properties of nanocomposites. For mechanical tests, tension mode of dynamical mechanical analysis (DMA) has been used

Plasmonic titanium nitride nanohole arrays for refractometric sensing

Group IVB metal nitrides have attracted great interest as alternative plasmonic materials. Among them, titanium nitride (TiN) stands out due to the ease of deposition and relative abundance of Ti compared to those of Zr and Hf metals. Even though they do not have Au or Ag-like plasmonic characteristics, they offer many advantages, from high mechanical stability to refractory behavior and complementary metal oxide semiconductor-compatible fabrication to tunable electrical/optical properties. In this study, we utilized reactive RF magnetron sputtering to deposit plasmonic TiN thin films. The flow rate and ratio of Ar/N2 and oxygen scavenging methods were optimized to improve the plasmonic performance of TiN thin films. The stoichiometry and structure of the TiN thin films were thoroughly investigated to assess the viability of the optimized operation procedures. To assess the plasmonic performance of TiN thin films, periodic nanohole arrays were perforated on TiN thin films by using electron beam lithography and reactive ion etching methods. The resulting TiN periodic nanohole array with varying periods was investigated by using a custom microspectroscopy setup for both reflection and transmission characteristics in various media to underline the efficacy of TiN for refractometric sensing.101111321 ; EP/Y030273/

Plasmonic Magnesium Nanoparticles Are Efficient Nanoheaters.

Publication status: PublishedUnderstanding and guiding light at the nanoscale can significantly impact society, for instance, by facilitating the development of efficient, sustainable, and/or cost-effective technologies. One emergent branch of nanotechnology exploits the conversion of light into heat, where heat is subsequently harnessed for various applications including therapeutics, heat-driven chemistries, and solar heating. Gold nanoparticles are overwhelmingly the most common material for plasmon-assisted photothermal applications; yet magnesium nanoparticles present a compelling alternative due to their low cost and superior biocompatibility. Herein, we measured the heat generated and quantified the photothermal efficiency of the gold and magnesium nanoparticle suspensions. Photothermal transduction experiments and optical and thermal simulations of different sizes and shapes of gold and magnesium nanoparticles showed that magnesium is more efficient at converting light into heat compared to gold at near-infrared wavelengths, thus demonstrating that magnesium nanoparticles are a promising new class of inexpensive, biodegradable photothermal platforms

Plasmonic Magnesium Nanoparticles Are Efficient Nanoheaters.

Understanding and guiding light at the nanoscale can significantly impact society, for instance, by facilitating the development of efficient, sustainable, and/or cost-effective technologies. One emergent branch of nanotechnology exploits the conversion of light into heat, where heat is subsequently harnessed for various applications including therapeutics, heat-driven chemistries, and solar heating. Gold nanoparticles are overwhelmingly the most common material for plasmon-assisted photothermal applications; yet magnesium nanoparticles present a compelling alternative due to their low cost and superior biocompatibility. Herein, we measured the heat generated and quantified the photothermal efficiency of the gold and magnesium nanoparticle suspensions. Photothermal transduction experiments and optical and thermal simulations of different sizes and shapes of gold and magnesium nanoparticles showed that magnesium is more efficient at converting light into heat compared to gold at near-infrared wavelengths, thus demonstrating that magnesium nanoparticles are a promising new class of inexpensive, biodegradable photothermal platforms

Aptamer and nanomaterial based FRET biosensors: a review on recent advances (2014–2019)

Fluorescence resonance energy transfer, one of the most powerful phenomena for elucidating molecular interactions, has been extensively utilized as a biosensing tool to provide accurate information at the nanoscale. Numerous aptamer- and nanomaterial-based FRET bioassays has been developed for detection of a large variety of molecules. Affinity probes are widely used in biosensors, in which aptamers have emerged as advantageous biorecognition elements, due to their chemical and structural stability. Similarly, optically active nanomaterials offer significant advantages over conventional organic dyes, such as superior photophysical properties, large surface-to-volume ratios, photostability, and longer shelf life. In this report (with 175 references), the use of aptamer-modified nanomaterials as FRET couples is reviewed: quantum dots, upconverting nanoparticles, graphene, reduced graphene oxide, gold nanoparticles, molybdenum disulfide, graphene quantum dots, carbon dots, and metal-organic frameworks. Tabulated summaries provide the reader with useful information on the current state of research in the field

Plasmonic magnesium arrays with nanosphere lithography

Magnesium is a rising alternative plasmonic metal that is potentially cheaper, more biocompatible, and less lossy in the ultraviolet-blue region of the visible spectrum than the commonly used gold and silver. Recent studies of colloidal magnesium nanoparticles demonstrated the plasmonic resonances of a variety of faceted shapes. However, applications such as refractive index sensing benefit from well-defined arrays, which have been developed for all other plasmonic metals. Here, we implement nanosphere lithography to fabricate metallic magnesium arrays that display attractive plasmonic properties. The deposition process was found to be highly vulnerable to oxidation, recrystallization, kinetic energy of the metal vapor, and substrate properties. The resulting structures obtained with 350, 500, and 750 nm hexagonally packed nanosphere masks exhibit the hallmark light–matter interactions of plasmonic metals, including strong extinction and resonance energy dependence on feature size, further securing Mg’s place as an alternative plasmonic metal

Theoretical calculations and experimental verification of the spectral signatures of metallic plates

In this study, we present theoretical calculations and experimental verification regarding the spectral distribution of emissivity constant, which plays an important role in the image formation in the hyperspectral imaging systems. In this study, the theoretical formulations regarding the spectral emissivity calculations for metal plates are provided. These metal plates are produced and their emissivity spectra are measured and compared with theoretical results. The experimental and theoretical results in this study show a good agreement. The emissivity spectrum calculations and measurement using alternative techniques is important for the development and improvement of hyperspectral imaging techniques

Determination of the accuracy ratio of palpation-guided acromioclavicular joint injection with contrast medium and fluoroscopy: A cadaver study

Amaç: Eklem içi enjeksiyonlar, kas iskelet sisteminin akut yaralanmalarında veya kronik durumlarda ağrıyı gidermede sık kullanılan tedavi yöntemlerinden biridir. Bu çalışmanın amacı, palpasyon ile kontrast madde verilerek yapılan akromiyoklaviküler (AK) eklem enjeksiyonlarının flöroskopi kontrolüyle doğruluk oranının beirlenmesidir.Gereç ve Yöntem: Bu kadavra çalışması İstanbul Adli Tıp Kurumu Etik Kurulu onayı ile gerçekleştirilmiştir. İstanbul Adli Tıp Kurumunda kadavralar enjeksiyon öncesi flöroskopi ile değerlendirilmiş ve AK eklemde artrozu olmayan 21 kadavranın 42 AK eklemi çalışmaya dâhil edilmiştir. Enjeksiyonların tamamı omuz alanında deneyimli bir ortopedist tarafından palpasyon tekniğiyle yapılmıştır. Enjeksiyonların doğruluk oranı her iki planda elde edilen flöroskopik görüntülerle değerlendirilmiştir.Bulgular: Yaş ortalaması 41 olan (Aralık: 29-48 yaş) 11 erkek ve 10 kadının her iki omzuna kontrast madde ile yapılan toplam 42 AK eklem enjeksiyonu çalışmaya dâhil edilmiştir. Yalnızca 17 enjeksiyonun AK eklemin içinde olduğu flöroskopi ile doğrulanmıştır (10'u sağ, 7'si sol, doğruluk oranı: %40,4). Doğru olan ve doğru olmayan enjeksiyonlar arasında ortalama yaş (sırasıyla 41 ve 42 yaş, p0,58), erkek/kadın oranı (p0,73) ve enjeksiyon yeri açısından anlamlı fark bulunmamıştır.Sonuç: Palpasyon ile körlemesine yapılan AK eklem enjeksiyonunun doğruluk oranı eklem patolojisi yokluğunda bile düşük bulunmuştur. Klinik uygulamada AK eklem enjeksiyonunun bir görüntüleme yöntemiyle birlikte yapılması, enjeksiyonun doğruluk oranını artırmaya yardımcı olabilir.Objective: Intra-articular injections are one of the commonly used treatment modalities for acute injuries or pain relief in chronic conditions of the musculoskeletal system. The aim of this study was to evaluate the accuracy rate of acromioclavicular (AC) joint injections made with palpation and contrast agent by fluoroscopy.Material and Methods: This cadaver study was carried out with the approval of Istanbul Forensic Medicine Institution Ethics Committee. Human cadavers were assessed by preinjection fluoroscopy at Istanbul Forensic Medicine Institute and forty-two AC joints of 21 cadavers without arthrosis were included in the study. All of the injections were made by palpation technique by an experienced orthopedist in the shoulder area. The accuracy of injections was assessed with fluoroscopic images obtained from both planes.Results: A total of 42 AC joint injections with contrast material of 11 male and 10 female patients with a mean age of 41 (range: 29-48 years) on both shoulders were included in the study. Only 17 injections were within the AC joint confirmed by fluoroscopy (10 right, 7 left, accuracy: 40.4%). There was no significant difference in the mean age (41 and 42 years, p0.58), male / female ratio (p0.73) and injection site between correct and incorrect injections.Conclusion: The accuracy rate of palpation-guided AC joint injection was found to be low even in the absence of joint pathology. In clinical practice, performing AC joint injection together with an imaging modality may help to increase the accuracy of the injection

Nanoplasmonic biosensors: Theory, structure, design, and review of recent applications

Nanoplasmonic biosensing shows an immense potential to satisfy the needs of the global health industry -low-cost, fast, and portable automated systems; highly sensitive and real-time detection; multiplexing and miniaturization. In this review, we presented the theory of nanoplasmonic biosensing for popular detection schemes -SPR, LSPR, and EOT -and underline the consideration for nanostructure design, material selection, and their effects on refractometric sensing performance. Later, we covered the bottom-up and top-down nanofabrication methods for nanoplasmonic biosensors. Subsequently, we reviewed the recent examples of nanoplasmonic biosensors over a wide range of clinically relevant analytes in the diagnosis and prognosis of a wide range of diseases and conditions such as biomarker proteins, infectious bacteria, viral agents. Finally, we discussed the challenges of nanoplasmonic biosensing toward clinical translation and proposed strategic avenues to be competitive against current clinical detection methods. Hopefully, nanoplasmonic biosensing can realize its potential through successful demonstrations of clinical translation in the upcoming years