Cellular Deformations Induced by Conical Silicon Nanowire Arrays Facilitate Gene Delivery

Engineered cell–nanostructured interfaces generated by vertically aligned silicon nanowire (SiNW) arrays have become a promising platform for orchestrating cell behavior, function, and fate. However, the underlying mechanism in SiNW-mediated intracellular access and delivery is still poorly understood. This study demonstrates the development of a gene delivery platform based on conical SiNW arrays for mechanical cell transfection, assisted by centrifugal force, for both adherent and nonadherent cells in vitro. Cells form focal adhesions on SiNWs within 6 h, and maintain high viability and motility. Such a functional and dynamic cell–SiNW interface features conformational changes in the plasma membrane and in some cases the nucleus, promoting both direct penetration and endocytosis; this synergistically facilitates SiNW-mediated delivery of nucleic acids into immortalized cell lines, and into difficult-to-transfect primary immune T cells without pre-activation. Moreover, transfected cells retrieved from SiNWs retain the capacity to proliferate—crucial to future biomedical applications. The results indicate that SiNW-mediated intracellular delivery holds great promise for developing increasingly sophisticated investigative and therapeutic tools. © 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinhei

Light-induced reflectivity transients in black-Si nanoneedles

© 2015 Elsevier B.V. All rights reserved. The change in reflectivity of black-Si (b-Si) upon optical excitation was measured by the pump-probe technique using picosecond laser pulses at 532 (pump) and 1064 nm (probe) wavelengths. The specular reflection from the random pattern of plasma-etched b-Si nano-needles was dominated by the photo-excited free-carrier contribution to the reflectivity. The kinetics of the reflectivity were found to be consistent with surface structural and chemical analysis, performed by scanning and transmission electron microscopy, and spectroscopic ellipsometry. The surface recombination velocity on the b-Si needles was estimated to be ~102cm/s. Metalization of b-Si led to much faster recombination and alteration of reflectivity. The reflectivity spectra of random b-Si surfaces with different needle lengths was modeled by a multi-step refractive index profile in the Drude formalism. The dip in the reflectivity spectra and the sign reversal in the differential reflectivity signal at certain b-Si needle sizes is explained by the model

Arable soil layer overturn angle influence on spring barley crop weediness applying non-chemical weed control system

Weed management still remains one of the biggest problems in agriculture, especially in organic farming, where usage of synthetic herbicides is prohibited. Ploughing is considered as best way to solve this issue. Topsoil overturn angle is very important ploughing parameter, as it determines incorporation of plant residues and weed seeds into soil. There are several different plough types depending on their construction, work abilities and topsoil overturn angle. As a control treatment the most common plough's in Lithuania overturning angle - 135 degrees - was taken. Generally it overturns soil not efficiently enough to achieve qualitative weed control in non-chemical weed control system. Four different soil overturn angles were studied in model experiment carried out at the Experimental Station of Lithuanian University of Agriculture during 2009-2010. The smallest amount of weed seeds after overturn in 2009 within 0-20 cm soil layer was found in no tillage treatment. The top soil layer (0-5 cm) had least weed seed amount at turning soil by 135 and 180 degrees. The highest weed taken with spring barley crop at hard stage of maturity number and mass was found in treatment where soil had been overturned by 180 degreesVytauto Didžiojo universitetasŽemės ūkio akademij

The Influence of Arable Soil Turnover Angle on Spring Barley Crop Yield and Weediness

Tyrimo tikslas – nustatyti armens apvertimo kokybės įtaką vasarinių miežių (Hordeum vulgare L.) pasėlio piktžolėtumui modeliniame lauko tyrime. Modelinis lauko tyrimas vykdytas LŽŪU bandymų stotyje 2009-2010. Tirti keturi armens apvertimo variantai: armuo apverstas 135° (kontrolinis variantas), 157,5º ir 180° kampu bei neverčiamas (0°). Įrengti stacionarūs 0,25 m2 modeliniai laukeliai Nustatyta piktžolių vasarinių miežių derliuje, rūšinė sudėtis, biomasė ir skaičius, miežių antžeminės dalies biomasė ir stiebų skaičius, derlius, 1000 grūdų masė ir kiti parametrai. Pasėlio piktžolėtumo ir piktžolių sėklų pasiskirstymo armenyje duomenys vertinami dispersinės analizės metodu, nustatant esminio skirtumo ribą (R05, R01) ir vidurkių vidutinę kvadratinę paklaidą Apibendrinus tyrimo duomenis, gauti rezultatai parodė, kad esant skirtingam armens apvertimo kampui piktžolių biomasė pasėlyje skyrėsi iki 3 kartų. Piktžolių sėklų atsargose dirvoje vyravo trumpaamžės piktžolės, daugiausiai baltoji balanda (Chenopodium album L.). Paviršiniame dirvos sluoksnyje piktžolių sėklų pasiskirstymas tarp variantų buvo nevienodas (skyrėsi kelis kartus) skirtingais metais. Eksperimento rezultatai iš esmės patvirtino hipotezę, kad nuo armens apvertimo kampo priklauso pasėlio piktžolėtumas, tačiau reikėtų atlikti papildomus tyrimus ir nustatyti optimalų armens apvertimo kampą mūsų klimato ir dirvožemių sąlygomis.The aim of the investigation was to estimate the influence of arable soil turnover angle on spring barley (Hordeum vulgare L.) crop yield and weediness in model field experiment. The model field experiment carried out at the Experimental Station of LŽŪU in 2009-2010. Four arable soil turnover angle treatments were investigated: 135° (control treatment), 157.5° and 180° and not overturned (0°). Stationary 0.25 m-2 model fields were equipped. The following parameters were measured: weeds harvested along with barley (weed species composition, weed biomass and number), spring barley density, and stem density, yield, 1000 grain weight and other parameters. Weediness and weed seed distribution in the arable soil layer were assessed by variance method by determining the LSD05, LSD01 and the average SEM Summarized survey data revealed that weed biomass in the spring barley crop differed by three times at the different arable soil turnover angle, short-living weeds dominated in the seed bank, mostly Chenopodium album L., weed seed distribution in top soil layer as well as spring barley yield has been uneven between the treatments (several times) in different years. Experimental results broadly confirmed the hypothesis that the arable soil overturning angle has influence on the crop yield and weediness, but further studies should be carried out to determine the optimum turnover angle for our climate and soil conditions.Žemės ūkio akademijaVytauto Didžiojo universiteta

Investigation and evaluation of epizootic situation of porcine proliferative enteropathy

Porcine proliferative enteropathy (PE) is a common cause of digestive tract disease of weaned piglets and fattening pigs in all parts of the world. It is caused by intracellular bacteria L. intracellularis, and this disease manifests by varying degrees of diarrhea, small bowel lesions and alterations, high morbidity and mortality, which causes significant economic losses. Therefore, the aim of this work is to determine the epizootic situation of pig proliferative enteropathy caused by L. intracellularis in piglets of weaned and fattening age groups, to compare the etiology of clinically healthy, diseased and dead pigs. The research was carried out in Lithuanian University of Health Sciences, Microbiology and Virology during 2014-2017. From 2003 to 2012 fifty three cases of digestive tract disorders were analyzed (357 faeces samples were tested). The studies were carried using nested PCR method to identify L.intracellularis. It has been determined that, 53.8 % dead weaned pigs and 19.3 % fattening ones were infected with L. intracellularis in the cases of gastrointestinal diseases. In samples of sick weaned and fattening pigs L. intracellularis was found in 16.2 % and 14.1 % respectively. Analogous data were obtained from the same groups of pigs in the case of PE outbreaks. In dead weaned and fattening pig groups positive samples were in 77.8% and 47.8% of cases respectively. In sick weaned and fattening pig group positive samples were in 57.1% and 43.5% cases respectively. L. intracellularis was more prevalent in weaned piglets than the fattening pig group. Investigation of clinically healthy Lithuanian pigs showed that the prevalence of L. intracellularis ranged from 4.7 % to 50.0 % in different pig farm groups. Investigation of imported Danish and Estonian pigs (n=40) showed that one Danish pig was infected with L. intracellularis

Sensing platforms: nano-fabrication, characterization and integration

Gediminas has started his PhD studies in 2010 here at Swinburne in the Centre for Micro-photonics in the group of Applied plasmonics under the supervision of professor Juodkazis. At that time, brand new, state-of-the-art clean-room was being built and he was one of the lucky few students to perform his research at these facilities. Using latest technologies, Gediminas soon started pushing the boundaries of modern nanotechnology. Currently, co-author of more than 30 scientific papers, Gediminas continues his career as an engineer in one of the largest open access clean-rooms in Australia

Ion-beam and plasma etching of a conical-pores photonic crystal for thin-film solar cell

Conical holes bored in the active layer of a thin-film silicon solar cell by ion-beam lithography (IBL) show increase of effective optical absorption in the underlying silicon active layer. The optical properties are numerically simulated by the 3D finite-difference time-domain method (3D-FDTD), showing wideband increase of the UV, visible, and IR quantum efficiency. An experimental fabrication procedure is developed using IBL for high wide-area repeatability. A further optimization on the cone shapes is performed in order to make fabrication feasible with plasma etching techniques

High-precision interferometric monitoring of polymer swelling in an one-dollar optofluidic sensor

Swelling of poly-methylmethacrylate (PMMA) in weak solvents: water, ethanol and methanol was investigated by interferometry using a simple microfluidic sensor. A change of channel width by ±20 nm, comparable with the surface roughness of the polymer surface, is reliably detected and its temporal evolution was monitored in situ. Dynamics of polymer swelling over time periods from a few seconds to a few days were obtained. An optimized in-expensive microfluidic sensor design using hot embossing with gold sputtering is presented. Such a sensor can be used for high-fidelity adsorption-desorption interferometric sensing and its cost can be optimized for a single use