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استخراج مایع-مایع ذرات ویروسی با مایعات یونی
سال انتشار: 2021 - تعداد صفحات فایل pdf انگلیسی: 8 - تعداد صفحات فایل doc فارسی: 23 درحالیکه مایعات یونی (IL ها) قبلاً برای استخراج انواع مولکولهای زیستی از سیستمهای آبپوش استفاده میشدند، تاکنون استفاده از آنها بریا استخراج ذرات ویروسی به ندرت مورد بررسی قرار گرفته است. از آنجاکه روشهای کنونی برای استخراج ذرات ویروسی بسیار زمانبر، طاقتفرسا و نیازمند تجهیزات خاص هستند یا بازیابی بسیار اندکی دارند، هدف این پژوهش اثبات مفهومی، بررسی IL ها به عنوان راهحل احتمالی برای استخراج کل ذرات ویروسی است. در این مقاله تعداد 11 IL با روش پلاک و qPCR مورد ارزیابی قرار گرفتند تا مشخص شود آیا آنها ویژگیهای استخراجی کافی را دارند یا خیر. از غربالگری نخست توانستیم حداقل 4 مایع با ویژگیهای مناسب استخراج در حد 2 تا 4 لگاریتم واحد را شناسایی نماییم. امیدوارکنندهترین مایع یعنی [C4C1Pyr][NTf2] به کاهش بیش از 4 لگاریتم واحدی ویروس P100 و بیش از 3 لگاریتم واحدی برای PRD1 ختم شد. این IL با بررسی پایداری استخراج برای گسترههای مختلف pH و غلظت نمک و در حضور آلایندههای طبیعی، با جزئیات بیشتر ارزیابی شد. این بررسیها وابستگی به pH و عوامل متغیر بازدهی استخراج را نشان داد، در نتیجه بهترین نتایج در pH طبیعی برابر با 7.5 به دست آمد. علاوه بر مقدار ژنوم ویروسی در فاز آبپوش، وجود ویروسهای عفونی نیز مشخص شد. در نتیجه، این پژوهش اثبات مفهومی، برخی IL های دارای مشخصههای مناسب استخراج ویروس را شناسایی کرد و یک گام ارزشمند در تیمار آمادهسازی نمونههای آبی ارائه نمود.
کلیدواژه ها: مایعات یونی | ذرات ویروسی | ویروس | نمونههای آبپوش | استخراج مایع-مایع |
مقاله ترجمه شده |
2 |
To Hop or not to Hop: Exceptions in the FCS Diffusion Law
به هاپ آری یا نه : استثنائات در قانون پخش FCS-2020 Diffusion obstacles in membranes have not been directly visualized because of fast membrane dynamics and the
occurrence of subresolution molecular complexes. To understand the obstacle characteristics, mobility-based methods are
often used as an indirect way of assessing the membrane structure. Molecular movement in biological plasma membranes is
often characterized by anomalous diffusion, but the exact underlying mechanisms are still elusive. Imaging total internal reflection
fluorescence correlation spectroscopy (ITIR-FCS) is a well-established mobility-based method that provides spatially
resolved diffusion coefficient maps and is combined with FCS diffusion law analysis to examine subresolution membrane organization.
In recent years, although FCS diffusion law analysis has been instrumental in providing new insights into the membrane
structure below the optical diffraction limit, there are certain exceptions and anomalies that require further clarification. To this
end, we correlate the membrane structural features imaged by atomic force microscopy (AFM) with the dynamics measured using
ITIR-FCS. We perform ITIR-FCS measurements on supported lipid bilayers (SLBs) of various lipid compositions to characterize
the anomalous diffusion of lipid molecules in distinct obstacle configurations, along with the high-resolution imaging of the
membrane structures with AFM. Furthermore, we validate our experimental results by performing simulations on image grids
with experimentally determined obstacle configurations. This study demonstrates that FCS diffusion law analysis is a powerful
tool to determine membrane heterogeneities implied from dynamics measurements. Our results corroborate the commonly
accepted interpretations of imaging FCS diffusion law analysis, and we show that exceptions happen when domains reach
the percolation threshold in a biphasic membrane and a network of domains behaves rather like a meshwork, resulting in
hop diffusion. |
مقاله انگلیسی |
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Synaptic Specificity, Recognition Molecules, and Assembly of Neural Circuits
ویژگی سیناپسی ، مولکولهای تشخیص و مونتاژ مدارهای عصبی-2020 Developing neurons connect in specific and stereotyped ways to form the complex circuits that underlie
brain function. By comparison to earlier steps in neural development, progress has been slow
in identifying the cell surface recognition molecules that mediate these synaptic choices, but new
high-throughput imaging, genetic, and molecular methods are accelerating progress. Over the past
decade, numerous large and small gene families have been implicated in target recognition,
including members of the immunoglobulin, cadherin, and leucine-rich repeat superfamilies. We review
these advances and propose ways in which combinatorial use of multifunctional recognition
molecules enables the complex neuron-neuron interactions that underlie synaptic specificity. |
مقاله انگلیسی |
4 |
Light trapping induced flexible wrinkled nanocone SERS substrate for highly sensitive explosive detection
بستر SERS nanocone چین خورده انعطاف پذیر ناشی از به دام انداختن نور برای تشخیص مواد منفجره بسیار حساس-2020 We reported an ultrasensitive TNT detection method via a novel light trapping induced wrinkled nanocone
flexible SERS substrate, which was fabricated by colloidal lithography and oxygen plasma etching on transparent
PET film. Especially, a set of nanowrinkles with 50−60 nm was found on the sidewall of nanocone after etching.
By coating 30 nm gold film, this flexible SERS substrate provided uniform hot spots, which demonstrated high
reproducibility and sensitivity. 4-ATP molecules based Meisenheimer complex, which is a well-known chargetransfer
interaction between electron-poor TNT and electron-rich amino group, was taken to detect ultra-low
concentration of TNT explosive. The Raman signal of TNT was significantly enhanced by charge-transfer, light
trapping effect and coupled electromagnetic field. The detection sensitivity of TNT molecules was as low as
10−13mol/L, and show a good linear response in the range from 10−8 to 10−13mol/L. Consequently, by
brushing this flexible SERS substrate onto a cloth bag, trace amount of TNT residues with concentration as low as
10-10mol/L can be easily analyzed. It is believed that the proposed highly sensitive and uniform flexible substrate
provides a significant solution for trace analysis of TNT residue in criminal forensic, military and security check. Keywords: Nanocone | Nanowrinkle | Flexible materials | Light trapping | SERS |
مقاله انگلیسی |
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Vascularized neural constructs for ex-vivo reconstitution of blood-brain barrier function
سازه های عصبی عروقی برای بازسازی قبلی در داخل بدن و عملکرد سد خونی مغز-2020 Ex-vivo blood-brain barrier (BBB) model is of great value for studying brain function and drug development, but
it is still challenging to engineer macroscale three-dimensional (3D) tissue constructs to recapitulate physiological
and functional aspects of BBB. Here, we describe a delicate 3D vascularized neural constructs for ex-vivo
reconstitution of BBB function. The tissue-engineered tissue construct is based on a multicomponent 3D coculture
of four types of cells, which typically exist in the BBB and were spatially defined and organized to mimic
the in vivo BBB structure and function. A porous polycaprolactone/poly (D,L-lactide-co-glycolide) (PCL/PLGA)
microfluidic perfusion system works as the vasculature network, which was made by freeze-coating a 3D-printed
sacrificial template. Endothelial cells were seeded inside the channels of the network to form 3D interconnected
blood vessels; while other types of cells, including pericytes, astrocytes, and neurons, were co-cultured in a
collagen matrix wrapping the vasculature network to derive a vascularized neural construct that recapitulates in
vivo BBB function with great complexity and delicacy. Using this model, we successfully reconstituted BBB
function with parameters that are similar to the in vivo condition, and demonstrated the identification of BBBpenetrating
therapeutics by examining the molecular delivery to neuronal cells when relevant biologic molecules
were applied to the vasculature circulation system of the neural construct. Keywords: Tissue engineering | 3D printing | Organ on a chip | Blood-brain barrier | Vasculature network | Neuro-engineering | Drug screening |
مقاله انگلیسی |
6 |
Serotonin induces Arcadlin in hippocampal neurons
سروتونین آرکادلین را در سلول های عصبی هیپوکامپ القا می کند-2020 The monoamine hypothesis does not fully explain the delayed onset of recovery after antidepressant treatment or
the mechanisms of recovery after electroconvulsive therapy (ECT). The common mechanism that operates both
in ECT and monoaminergic treatment presumably involves molecules induced in both of these conditions. A
spine density modulator, Arcadlin (Acad), the rat orthologue of human Protocadherin-8 (PCDH8) and of Xenopus
and zebrafish Paraxial protocadherin (PAPC), is induced by both electroconvulsive seizure (ECS) and antidepressants;
however, its cellular mechanism remains elusive. Here we confirm induction of Arcadlin upon
stimulation of an N-methyl-D-aspartate (NMDA) receptor in cultured hippocampal neurons. Stimulation of an
NMDA receptor also induced acute (20 min) and delayed (2 h) phosphorylation of the p38 mitogen-activated
protein (MAP) kinase; the delayed phosphorylation was not obvious in Acad–/– neurons, suggesting that it depends
on Arcadlin induction. Exposure of highly mature cultured hippocampal neurons to 1–10 μM serotonin for
4 h resulted in Arcadlin induction and p38 MAP kinase phosphorylation. Co-application of the NMDA receptor
antagonist D-(-)-2-amino-5-phosphonopentanoic acid (APV) completely blocked Arcadlin induction and p38
MAP kinase phosphorylation. Finally, administration of antidepressant fluoxetine in mice for 16 days induced
Arcadlin expression in the hippocampus. Our data indicate that the Arcadlin-p38 MAP kinase pathway is a
candidate neural network modulator that is activated in hippocampal neurons under the dual regulation of
serotonin and glutamate and, hence, may play a role in antidepressant therapies. Keywords: Serotonin | Protocadherin | Adhesion | Synaptic plasticity | Antidepressant | Mitogen-activated protein kinase |
مقاله انگلیسی |
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Refinement of cerebellar network organization by extracellular signaling during development
پالایش سازمان شبکه مخچه با سیگنالینگ خارج سلولی در حین توسعه-2020 The cerebellum forms regular neural network structures consisting of a few major
types of neurons, such as Purkinje cells, granule cells, and molecular layer
interneurons, and receives two major inputs from climbing fibers and mossy fibers. Its
regular structures consist of three well-defined layers, with each type of neuron
designated to a specific location and forming specific synaptic connections. During the
first few weeks of postnatal development in rodents, the cerebellum goes through
dynamic changes via proliferation, migration, differentiation, synaptogenesis, and
maturation, to create such a network structure. The development of this organized
network structure presumably relies on the communication between developing
elements in the network, including not only individual neurons, but also their dendrites,
axons, and synapses. Therefore, it is reasonable that extracellular signaling via
synaptic transmission, secreted molecules, and cell adhesion molecules, plays
important roles in cerebellar network development. Although it is not yet clear as to
how overall cerebellar development is orchestrated, there is indeed accumulating lines
of evidence that extracellular signaling acts toward the development of individual
elements in the cerebellar networks. In this article, we introduce what we have learned
from many studies regarding the extracellular signaling required for cerebellar network
development, including our recent study suggesting the importance of unbiased
synaptic inputs from parallel fibers Keywords : synaptic inputs | extracellular signaling | Purkinje cells | cerebellar granule cells | molecular layer interneurons | climbing fibers |
مقاله انگلیسی |
8 |
Correlation and prediction of surface tension of highly non-ideal hydrous binary mixtures using artificial neural network
همبستگی و پیش بینی تنش سطحی مخلوطهای باینری هیدروژن غیر ایده آل با استفاده از شبکه عصبی مصنوعی-2020 Prediction of surface tension of highly non-ideal binary aqueous–organic mixtures is crucial for interpreting the
interaction between the molecules. In this regard, a multi-layer perceptron (MLP) artificial neural network
(ANN) model is developed to predict the binary aqueous–organic surface tension as a function of mixture
composition and temperature while the organic compounds are very dissimilar in size and type. To correlate the
binary surface tension, gathered experimental surface tension data consisted of 30 binary mixtures containing
2271 data points in the wide temperature range of 273–471.15 K are randomly divided into three different
subsets namely training (70 % of total data), validation (15 % of total data) and testing (15 % of total data)
subsets. Different input variables are examined and the number of hidden neurons is optimized. The obtained
results revealed that it is possible to correlate the binary surface tension with the best MLP network with 27
neurons in the hidden layer and inputs variables of temperature, mole fraction, molecular weight and critical
pressure of non-water component with the average absolute relative deviation (AARD %) of lower than 1.43 %.
Comparison of accuracy of the MLP model with several common models such as Jouyban-Acree model, Wilson
equation, Paquette and Rasmussen areas and several equations of state including SRK, PR and CPA revealed
more accuracy of the proposed MLP based model. Keywords: Surface tension | Modeling | Binary mixture | Non-ideal | ANN |
مقاله انگلیسی |
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A self-assembled layer-by-layer surface modification to fabricate the neuron-rich model from neural stem/precursor cells
اصلاح سطح لایه به لایه خود مونتاژ برای ساخت مدل غنی از نورون از سلولهای بنیادی / پیش ساز عصبی-2020 Background/Purpose: In vitro neural cell-based models have been widely used to mimic the
in vivo neural tissue environments and quantitatively understand the effects of pharmaceutical
molecules on neural diseases. Recently, several biomimetic neural tissue models have
been widely developed by using biomaterials or surface modification. However, the complex
protocols of material synthesis or surface modification lack an easy execution to fabricate
the neuron favorite environment.
Methods: In this study, we utilized a layer-by-layer technique as a surface modification method
for regulating the behaviors of neural stem/precursor cells (NSPCs) on material surfaces. Polyelectrolyte
multilayers (PEMs) via alternate deposition of poly (allylamine hydrochloride) (PAH)
and poly (sodium-4-styrenesulfonate) (PSS) were used to culture NSPCs. After incubation for 7
days, the neuronal differentiation of NSPCs and synapse function of differentiated neurons
were identified by immunocytochemistry for lineage specific markers.
Results: Compared with the only PAH film, the PSS-ending film (neuron-rich model) was
shown to significantly promote differentiation of NSPCs into neurons (more than 50%), form
a neuronal network structure; and differentiated neurons exhibiting functional synaptic
activity. KEYWORDS : Polyelectrolyte multilayer (PEM) | Neural stem/ precursor cells | (NSPCs) | Neuronal | differentiation | Neurite outgrowth |
مقاله انگلیسی |
10 |
Visualizing Mitochondrial Form and Function within the Cell
تجسم فرم و عملکرد میتوکندری در سلول-2020 The specific cellular role of mitochondria is influenced by the surrounding environment because
effective mitochondrial function requires the delivery of inputs (e.g., oxygen) and export of
products (e.g., signaling molecules) to and from other cellular components, respectively. Recent
technological developments in mitochondrial imaging have led to a more precise and comprehensive
understanding of the spatial relationships governing the function of this complex organelle,
opening a new era of mitochondrial research. Here, I highlight current imaging approaches
for visualizing mitochondrial form and function within complex cellular environments. Increasing
clarity of mitochondrial behavior within cells will continue to lend mechanistic insights into the
role of mitochondria under normal and pathological conditions and point to spatially regulated
processes that can be targeted to improve cellular function |
مقاله انگلیسی |