A Simple Method for Calculation of the Composition of Type I Clathrate Hydrates

2012 ◽  
Vol 638 (3-4) ◽  
pp. 648-651
Author(s):  
László Kótai ◽  
Szabolcs Bálint ◽  
István Gács ◽  
Györgyi Lakatos ◽  
András Angyal ◽  
...  
Keyword(s):  
Clathrate Hydrates ◽  
Type I ◽  
Simple Method

scholarly journals The Regularity of Sustained Firing Reveals Two Populations of Slowly Adapting Touch Receptors in Mouse Hairy Skin

2010 ◽  
Vol 103 (6) ◽  
pp. 3378-3388 ◽  
Author(s):  
Scott A. Wellnitz ◽  
Daine R. Lesniak ◽  
Gregory J. Gerling ◽  
Ellen A. Lumpkin
Keyword(s):  
Fluorescent Protein ◽  
Ex Vivo ◽  
Receptive Fields ◽  
Receptor Subtypes ◽  
Type I ◽  
Genetic Dissection ◽  
Merkel Cells ◽  
Simple Method ◽  
Green Fluorescent ◽  
Nerve Recordings

Touch is initiated by diverse somatosensory afferents that innervate the skin. The ability to manipulate and classify receptor subtypes is prerequisite for elucidating sensory mechanisms. Merkel cell–neurite complexes, which distinguish shapes and textures, are experimentally tractable mammalian touch receptors that mediate slowly adapting type I (SAI) responses. The assessment of SAI function in mutant mice has been hindered because previous studies did not distinguish SAI responses from slowly adapting type II (SAII) responses, which are thought to arise from different end organs, such as Ruffini endings. Thus we sought methods to discriminate these afferent types. We developed an epidermis-up ex vivo skin–nerve chamber to record action potentials from afferents while imaging Merkel cells in intact receptive fields. Using model-based cluster analysis, we found that two types of slowly adapting receptors were readily distinguished based on the regularity of touch-evoked firing patterns. We identified these clusters as SAI (coefficient of variation = 0.78 ± 0.09) and SAII responses (0.21 ± 0.09). The identity of SAI afferents was confirmed by recording from transgenic mice with green fluorescent protein–expressing Merkel cells. SAI receptive fields always contained fluorescent Merkel cells ( n = 10), whereas SAII receptive fields lacked these cells ( n = 5). Consistent with reports from other vertebrates, mouse SAI and SAII responses arise from afferents exhibiting similar conduction velocities, receptive field sizes, mechanical thresholds, and firing rates. These results demonstrate that mice, like other vertebrates, have two classes of slowly adapting light-touch receptors, identify a simple method to distinguish these populations, and extend the utility of skin–nerve recordings for genetic dissection of touch receptor mechanisms.

Antegrade Transsphenoidal Vidian Neurectomy: Short-Term Surgical Outcome Analysis

2011 ◽  
Vol 25 (6) ◽  
pp. e217-e220 ◽  
Author(s):  
Wan-Fu Su ◽  
Shao-Cheng Liu ◽  
Feng-Shiang Chiu ◽  
Chia-Hsuan Lee
Keyword(s):  
Allergic Rhinitis ◽  
Surgical Outcomes ◽  
Transsphenoidal Approach ◽  
Type I ◽  
Type Ii ◽  
Short Term ◽  
Surgical Morbidity ◽  
Simple Method ◽  
Vidian Neurectomy

Background Vidian neurectomy was an option for treating allergic rhinitis in the past but outcomes varied. A modified transsphenoidal approach is proposed to simplify endoscopic vidian neurectomy. The postoperative evaluation of rhinorrhea, sneezing, and recurrence was investigated. Methods A total of 317 patients with refractory allergic rhinitis underwent 414 transsphenoidal vidian neurectomies from September 2006 to December 2010. A rigid nasal endoscope was used through a transsphenoidal approach to reach the vidian canal inside the sphenoid sinus (type I) or through its anterior opening into the pterygopalatine fossa (type II) and to cut or cauterize the vidian nerve. The surgical outcomes were analyzed for patients with at least 6 months of follow-up. Results Our approach was successful in 90.3% of the 414 vidian neurectomies. Vidian neurectomy was successful via the type I approach in 27 sides and type II approach in 347 sides. The short-term surgical outcomes of 163 patients who underwent a total of 236 vidian neurectomies with at least 6 months of follow-up were analyzed. Immediate, complete cessation of sneezing and rhinorrhea occurred uniformly. Three recurrences were detected during the 1–2 years of follow-up. The symptom of dry eye was reported for 172 surgical sides, but only 6 had persistent symptoms for > 6 months. Conclusion The transsphenoidal approach in a vidian neurectomy is a simple method that removes the need for sphenopalatine artery ligation and causes less surgical morbidity. However, the possibility of recurrence of this condition in the long term needs further investigation.

scholarly journals Increased Fibroblast Metabolic Activity of Collagen Scaffolds via the Addition of Propolis Nanoparticles

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3118
Author(s):  
Jeimmy González-Masís ◽  
Jorge M. Cubero-Sesin ◽  
Yendry R. Corrales-Ureña ◽  
Sara González-Camacho ◽  
Nohelia Mora-Ugalde ◽  
...  
Keyword(s):  
Metabolic Activity ◽  
Self Assembly ◽  
Type I Collagen ◽  
Fibroblast Cell ◽  
Antimicrobial Activities ◽  
Hydrodynamic Diameter ◽  
Type I ◽  
Collagen Scaffolds ◽  
Simple Method ◽  
Socially Relevant

Propolis natural extracts have been used since ancient times due to their antioxidant, anti-inflammatory, antiviral, and antimicrobial activities. In this study, we produced scaffolds of type I collagen, extracted from Wistar Hanover rat tail tendons, and impregnated them with propolis nanoparticles (NPs) for applications in regenerative medicine. Our results show that the impregnation of propolis NPs to collagen scaffolds affected the collagen denaturation temperature and tensile strength. The changes in structural collagen self-assembly due to contact with organic nanoparticles were shown for the first time. The fibril collagen secondary structure was preserved, and the D-pattern gap increased to 135 ± 28 nm, without losing the microfiber structure. We also show that the properties of the collagen scaffolds depended on the concentration of propolis NPs. A concentration of 100 μg/mL of propolis NPs with 1 mg of collagen, with a hydrodynamic diameter of 173 nm, was found to be an optimal concentration to enhance 3T3 fibroblast cell metabolic activity and cell proliferation. The expected outcome from this research is both scientifically and socially relevant since the home scaffold using natural nanoparticles can be produced using a simple method and could be widely used for local medical care in developing communities.

scholarly journals Pilot Study on the Efficiency of the Biostimulation with Autologous Plasma Rich in Platelet Growth Factors in Otorhinolaryngology: Otologic Surgery (Tympanoplasty Type I)

ISRN Surgery ◽  
2011 ◽  
Vol 2011 ◽  
pp. 1-4 ◽  
Author(s):  
María Luisa Navarrete Álvaro ◽  
N. Ortiz ◽  
L. Rodriguez ◽  
R. Boemo ◽  
J. F. Fuentes ◽  
...  
Keyword(s):  
Growth Factors ◽  
Tympanic Membrane ◽  
Biological Tissues ◽  
Tympanic Membrane Perforation ◽  
Coagulation Cascade ◽  
Type I ◽  
Success Rates ◽  
Autologous Plasma ◽  
Simple Method ◽  
The Moment

When otologic procedures that involve tympanic membrane repairs are performed, biomaterials or biological tissues as normal as grafts are used. At the moment, biological material from the own patient is used with varying success rates. The procedure used and the patient's tissue repair capabilities tend to determine the outcome. We present a preliminary study on tympanic membrane perforation repairs using an autograft obtained by manipulating platelet degranulation and the coagulation cascade and reinforced with a seal using platelet growth factors. We present three cases in which we used this procedure. The results will be valued based on the tympanic perforation closure index. With this study, we want to assess the effectiveness of tympanic perforation repairs with this technically simple method. If this method was objectively proved to be effective, it would lead to lower patient morbidity and sanitary costs.

scholarly journals A durable and biocompatible ascorbic acid-based covalent coating method of polydimethylsiloxane for dynamic cell culture

2017 ◽  
Vol 14 (132) ◽  
pp. 20170318 ◽  
Author(s):  
Joni Leivo ◽  
Sanni Virjula ◽  
Sari Vanhatupa ◽  
Kimmo Kartasalo ◽  
Joose Kreutzer ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Cell Attachment ◽  
Collagen Type I ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Type I ◽  
Simple Method ◽  
Dynamic Conditions ◽  
Coating Method ◽  
Cross Linker

Polydimethylsiloxane (PDMS) is widely used in dynamic biological microfluidic applications. As a highly hydrophobic material, native PDMS does not support cell attachment and culture, especially in dynamic conditions. Previous covalent coating methods use glutaraldehyde (GA) which, however, is cytotoxic. This paper introduces a novel and simple method for binding collagen type I covalently on PDMS using ascorbic acid (AA) as a cross-linker instead of GA. We compare the novel method against physisorption and GA cross-linker-based methods. The coatings are characterized by immunostaining, contact angle measurement, atomic force microscopy and infrared spectroscopy, and evaluated in static and stretched human adipose stem cell (hASC) cultures up to 13 days. We found that AA can replace GA as a cross-linker in the covalent coating method and that the coating is durable after sonication and after 6 days of stretching. Furthermore, we show that hASCs attach and proliferate better on AA cross-linked samples compared with physisorbed or GA-based methods. Thus, in this paper, we provide a new PDMS coating method for studying cells, such as hASCs, in static and dynamic conditions. The proposed method is an important step in the development of PDMS-based devices in cell and tissue engineering applications.

Theoretical studies on microstructures, stabilities and formation conditions of some sour gas in the type I, II, and H clathrate hydrates

2018 ◽  
Vol 1153 ◽  
pp. 292-298
Author(s):  
Xuran Zhang ◽  
Nianxiang Qiu ◽  
Qing Huang ◽  
Xianhu Zha ◽  
Jian He ◽  
...  
Keyword(s):  
Clathrate Hydrates ◽  
Type I ◽  
Theoretical Studies ◽  
Formation Conditions ◽  
Sour Gas

scholarly journals Fiber Crimp Confers Matrix Mechanical Nonlinearity, Regulates Endothelial Cell Mechanosensing, and Promotes Microvascular Network Formation

2020 ◽  
Vol 142 (11) ◽  
Author(s):  
Christopher D. Davidson ◽  
Danica Kristen P. Jayco ◽  
William Y. Wang ◽  
Ariella Shikanov ◽  
Brendon M. Baker
Keyword(s):  
Type I Collagen ◽  
Network Formation ◽  
Critical Role ◽  
Type I ◽  
Matrix Remodeling ◽  
Simple Method ◽  
Nonlinear Stress ◽  
Nonlinear Mechanical ◽  
Hydrophilic Peptide ◽  
Fibrous Matrices

Abstract Mechanical interactions between cells and their surrounding extracellular matrix (ECM) guide many fundamental cell behaviors. Native connective tissue consists of highly organized, 3D networks of ECM fibers with complex, nonlinear mechanical properties. The most abundant stromal matrix component is fibrillar type I collagen, which often possesses a wavy, crimped morphology that confers strain- and load-dependent nonlinear mechanical behavior. Here, we established a new and simple method for engineering electrospun fibrous matrices composed of dextran vinyl sulfone (DexVS) with controllable crimped structure. A hydrophilic peptide was functionalized to DexVS matrices to trigger swelling of individual hydrogel fibers, resulting in crimped microstructure due to the fixed anchorage of fibers. Mechanical characterization of these matrices under tension confirmed orthogonal control over nonlinear stress–strain responses and matrix stiffness. We next examined ECM mechanosensing of individual endothelial cells (ECs) and found that fiber crimp promoted physical matrix remodeling alongside decreases in cell spreading, focal adhesion area, and nuclear localization of Yes-associated protein (YAP). These changes corresponded to an increase in migration speed, along with evidence for long-range interactions between neighboring cells in crimped matrices. Interestingly, when ECs were seeded at high density in crimped matrices, capillary-like networks rapidly assembled and contained tube-like cellular structures wrapped around bundles of synthetic matrix fibers due to increased physical reorganization of matrix fibers. Our work provides an additional level of mechanical and architectural tunability to synthetic fibrous matrices and implicates a critical role for mechanical nonlinearity in EC mechanosensing and network formation.

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