Variability and temperature dependence of the velocity of retrograde particle transport in myelinated axons

1981 ◽  
Vol 59 (8) ◽  
pp. 857-863 ◽  
Author(s):  
Richard S. Smith ◽  
Paul D. Cooper
Keyword(s):  
Temperature Dependence ◽  
Particle Velocity ◽  
Coefficient Of Variation ◽  
Room Temperature ◽  
Common Mechanism ◽  
Morphological Evidence ◽  
Myelinated Axons ◽  
Wide Range ◽  
Significant Difference ◽  
The Mean

The velocity of the retrograde transport of optically detectable particles was studied in isolated myelinated axons from Xenopus laevis at room temperature and with varying temperature. At room temperature (22–23.1 °C) the mean particle velocity was significantly different in some axons of the same animal. Results pooled from a number of axons did not indicate any significant difference in the average particle velocity in different animals. At room temperature, even though the mean particle velocity might differ between axons, the coefficient of variation of particle velocity in separate fibers tended to remain constant.The temperature dependence of mean particle velocity (V) could be adequately described by the relationship V = 0.26 exp 0.073T – 0.33, where V is in micrometres per second and T is degrees Celsius. Throughout the temperature range at which transport took place (approximately 5–35 °C) the coefficient of variation of particle velocity remained approximately constant at 0.40. All particles ceased their motion abruptly, and to some extent reversibly, at 37 °C. On morphological evidence, none of the effects of temperature appeared to be related to microtubule depolymerization.The results indicate that retrogradely transported particles with a wide range of velocities respond homogeneously to temperature changes. This supports the view that a common mechanism may underlie the motion of all the particles. No evidence was obtained that the differences between axons at room temperature could be attributed to the presence in separate axons of dissimilar proportions of faster and slower particles. Nor was the velocity–temperature characteristic in the region of room temperature sufficiently steep to explain the differences between axons. It is suggested that axons may differ in general mechanical or chemical properties so that the motion of all particles is affected uniformly.

Consumer Prices for Surgical Management of End-Stage Hallux Rigidus

2019 ◽  
Vol 13 (4) ◽  
pp. 276-280
Author(s):  
Niall A. Smyth ◽  
Vaishnavi Krishnan ◽  
Johnathon R. McCormick ◽  
Jonathan R. Kaplan ◽  
Amiethab A. Aiyer
Keyword(s):  
Health Care ◽  
Hallux Rigidus ◽  
Treatment Modalities ◽  
Potential Cost ◽  
First Metatarsophalangeal Joint ◽  
Consumer Prices ◽  
Wide Range ◽  
Significant Difference ◽  
The Mean ◽  
End Stage

Background. Hallux rigidus is the most prevalent arthritic condition of the foot. Treatment of end-stage disease traditionally consists of a first metatarsophalangeal joint (MTPJ) arthrodesis; however, the use of a synthetic cartilage implant is becoming more common. With the high prevalence of disease and implementation of new treatment modalities, health care consumers should be aware of the costs associated with management. The purpose of this study was to determine access to the cost and variability in price of first MTPJ arthrodesis and synthetic cartilage implantation. Methods. Forty academic centers were contacted using a standardized patient script. The patient was a 59-year-old female who had failed conservative treatment of hallux rigidus. Each institution was contacted up to 3 times in an attempt to obtain a full bundled operative quote for a first MTPJ arthrodesis and synthetic cartilage implantation. Results. Twenty centers (50%) provided a quote for first MTPJ arthrodesis and 15 centers (38%) provided a quote for synthetic cartilage implantation. Only 14 centers (35%) were able to provide a quote for both procedures. The mean bundled price for MTPJ arthrodesis was $21 767 (range $8417 to $39 265). The mean bundled price for synthetic cartilage implantation was $21 546 (range $4903 to $74 145). There was no statistically significant difference between the bundled price for first MTPJ arthrodesis and synthetic cartilage implantation. Conclusions. There was limited availability of consumer prices for first MTPJ arthrodesis and synthetic implantation, thus impeding health care consumers’ decision making. There was a wide range of quotes for both procedures, indicating potential cost savings. Levels of Evidence: IV, basic science

scholarly journals The duration of pubertal growth peak among three skeletal classes

2016 ◽  
Vol 21 (5) ◽  
pp. 67-74 ◽  
Author(s):  
Waqar Jeelani ◽  
◽  
Mubassar Fida ◽  
Attiya Shaikh ◽  
◽  
...  
Keyword(s):  
Class Ii ◽  
Growth Potential ◽  
Class I ◽  
Maturation Stage ◽  
Class Iii ◽  
Pubertal Growth ◽  
Lateral Cephalograms ◽  
Wide Range ◽  
Significant Difference ◽  
The Mean

ABSTRACT Introduction: Pubertal growth peak is closely associated with a rapid increase in mandibular length and offers a wide range of therapeutic modifiability. Objective: The aim of the present study was to determine and compare the mean ages of onset and duration of pubertal growth peak among three skeletal classes. Methods: A retrospective cross-sectional study was conducted using lateral cephalograms of 230 subjects with growth potential (110 males, 120 females). Subjects were categorized into three classes (Class I = 81, Class II = 82, Class III = 67), according to the sagittal relationship established between the maxilla and the mandible. The cervical vertebral maturation stage was recorded by means of Baccetti's method. The mean ages at CS3 and CS4 and the CS3-CS4 age interval were compared between boys and girls and among three skeletal classes. Results: Pubertal growth peak occurred on average four months earlier in girls than boys (p = 0.050). The average duration of pubertal growth peak was 11 months in Class I, seven months in Class II and 17 months in Class III subjects. Interclass differences were highly significant (Cohen's d > 0.08). However, no significant difference was found in the timing of pubertal growth peak onset among three skeletal classes (p = 0.126 in boys, p = 0.262 in girls). Conclusions: Girls enter pubertal growth peak on average four months earlier than boys. Moreover, the duration of pubertal growth peak is on average four months shorter in Class II and six months longer in Class III subjects as compared to Class I subjects.

Notiz: Temperature Dependence of the Proton NMR Spectra of Bitumen

1997 ◽  
Vol 52 (4) ◽  
pp. 373-376 ◽  
Author(s):  
J. Dolinšek ◽  
G. Lahajnar ◽  
B. Marin ◽  
J. Pirš ◽  
A. Sepe ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Transition Region ◽  
Nmr Spectra ◽  
Room Temperature ◽  
Proton Nmr ◽  
Significant Difference ◽  
Different Origin

Abstract The temperature dependence of the proton NMR spectra of bitumen samples of different origin and quality has been measured between 400 K and 80 K. Whereas the linewidths of different samples are essentially identical above 340 K and below 240 K, there is a significant difference in the linewidth transition region around room temperature.The results show that it is possible to discriminate between bitumen samples of different composition and quality by simply measuring the proton NMR linewidth at room temperature.

Dielectric Properties of Pulsed Excimer Laser Ablated BaBi2Nb2O9 Thin Films

2002 ◽  
Vol 748 ◽  
Author(s):  
Apurba Laha ◽  
S. B. Krupanidhi ◽  
S. Saha
Keyword(s):  
Thin Films ◽  
Phase Transition ◽  
Dielectric Constant ◽  
Temperature Dependence ◽  
Loss Tangent ◽  
Dielectric Response ◽  
Room Temperature ◽  
Dielectric Constant And Loss ◽  
Wide Range ◽  
Room Temperature Dielectric Constant

ABSTRACTThe dielectric response of BaBi2Nb2O9 (BBN) thin films has been studied as a function of frequency over a wide range of temperatures. Both dielectric constant and loss tangent of BBN thin films showed a ‘power law’ dependence with frequency, which was analyzed using the Jonscher's universal dielectric response model. Theoretical fits were utilized to compare the experimental results and also to estimate the value of temperature dependence parameters such as n(T) and a(T) used in the Jonscher's model. The room temperature dielectric constant (ε') of the BBN thin films was 214 with a loss tangent (tanδ) of 0.04 at a frequency of 100 kHz. The films exhibited the second order dielectric phase transition from ferroelectric to paraelectric state at a temperature of 220 °C. The nature of phase transition was confirmed from the temperature dependence of dielectric constant and sponteneous polarization,respectively. The calculated Currie constant for BBN thin films was 4 × 105°C.

scholarly journals Dosimetry of Critical Organs in Maxillofacial Imaging with Cone-beam Computed Tomography

2019 ◽  
Vol 9 (1Feb) ◽  
Author(s):  
R Ghanbarnezhad Farshi ◽  
A Mesbahi ◽  
M Johari ◽  
Ü Kara ◽  
N Gharehaghaji
Keyword(s):  
Computed Tomography ◽  
Cone Beam Computed Tomography ◽  
Cone Beam ◽  
Radiation Doses ◽  
Parotid Glands ◽  
Thermoluminescent Dosimeters ◽  
Wide Range ◽  
Significant Difference ◽  
The Mean ◽  
Selection Of

Background: While the benefits of cone-beam computed tomography (CBCT) are well known in maxillofacial imaging, the use of this modality is not risk-free.Objective: The aim of this study was to evaluate the exposure doses received by patients during maxillofacial imaging with CBCT.Methods: Entrance surface dose (ESD) was measured by using thermoluminescent dosimeters (TLDs) attached to the eyes lids, parotid glands and thyroid of 64 patients in two imaging centers (A and B). Phantom dosimetry was performed by a cylindrical poly-methyl methacrylate (PMMA) head-size phantom and an ionization chamber for different exposure parameters. NewTom VGi and Planmeca Promax 3D CBCT scanners were used at centers A and B, respectively.Results: The mean ESD of the eyes, parotid glands and thyroid were 2.57, 2.33 and 0.28 mGy in center A, 0.35, 2.11 and 0.37 mGy in center B, respectively. ESD of the eyes revealed a significant difference in two centers; in center B, it was 86.4% lower than center A. In the phantom dosimetry, the measured doses of NewTom VGi were 2.63 and 2.08 mGy, respectively by changing field of view (FOV) size from 8×8 cm2 (height × diameter) to 6×6 cm2. For Planmeca Promax 3D, it ranged from 0.98 to 3.24 mGy depending on exposure parameters.Conclusion: There is a wide range of radiation doses dependent on the units, patients and selected scan parameters. Inappropriate selection of exposure settings, especially FOV size, can seriously increase patient dose.

scholarly journals Evaluation of Iodine in Distributed Salts in Abarkouh City in 2017-2018

2018 ◽  
pp. 659-665
Author(s):  
Mahrokh Mahrokh Jalili ◽  
Ali Asghar Ebrahimi ◽  
Mohammad Hassan Ehrampoush ◽  
Fariba Abbasi ◽  
Eslami Hadi Eslami ◽  
...  
Keyword(s):  
Iodine Deficiency ◽  
Random Sampling ◽  
Clinical Manifestations ◽  
Iodine Concentration ◽  
T Test ◽  
British Pharmacopoeia ◽  
Wide Range ◽  
Significant Difference ◽  
The Mean ◽  
The City

Introduction: Iodine deficiency and associated disorders, which lead to a wide range of clinical manifestations, have been raised as one of the health and nutritional problems in Iran. Therefore, this study was aimed to investigate the amount of iodine in distributed salts in Abarkouh city in 2017-2018. Materials and Methods: Random sampling was done by census on all 30 distributed brands in Abarkouh city in the different stores across the city. Sixty samples (30 samples after one month from the production date and 30 samples after 6 months from the production date) were collected and transferred to the laboratory. The measurement of iodine was done according to the British Pharmacopoeia recommended method. T-test was used to analyze the data. Results: The Mean iodine concentration in the salts supplied in the Abarkouh was 29.83 ± 19.9 ppm, which was 50% less than the Iran's standard, with a statistically significant difference (P ≤ 0.001). 66.6% of the studied brands did not contain adequate iodine. Six months after production date, the average iodine amount in salts was reduced to 24.26 ± 16.94 ppm, but the reduction was not statistically significant (P = 0.224). Conclusion: Average iodine amount in most of the salts supplied across the Abarkouh city was not acceptable and some salts lacked iodine. Therefore, careful and continuous supervision and monitoring the process of iodized salts production in factories is recommended.

Room-Temperature Nanoimprint Lithography

2006 ◽  
Vol 961 ◽  
Author(s):  
Ken-Ichiro Matsui ◽  
Shinji Matsui
Keyword(s):  
Liquid Phase ◽  
Temperature Dependence ◽  
Nanoimprint Lithography ◽  
Room Temperature ◽  
Hydrogen Silsesquioxane ◽  
Wide Range ◽  
One Step

ABSTRACTRoom-temperature nanoimprint lithography (RT-NIL) using spin-coated hydrogen silsesquioxane (HSQ) resin as the replication material was developed. HSQ pattern with 50 nm linewidth was successfully obtained by the RT-NIL. Postbaking temperature dependence of a HSQ imprinted depth on a mold linewidth was investigated. HSQ imprinted depth had a dependence on the mold linewidth. This revealed that the RT-NIL is suitable for the linewidths of below 1 mm. Furthermore, we have also developed a new imprinting technique that uses liquid-phase hydrogen silsesquioxane (HSQ) as an alternative to the spin-coated HSQ resin. The liquid-phase HSQ imprint technique enabled fabrication of various HSQ patterns with a wide range of linewidths from 25 nm to 300 mm. Arbitrary patterns, including both submicron and greater than 100 micron patterns, were simultaneously replicated with a one-step imprint process, something very difficult to accomplish with spin-coated HSQ. Moreover, after imprinting, the residual HSQ layer in the compressed area was less than 10 nm thick.

81Br and 127 I NQR Studies of (CH3NH3)2HgBr4 and (CH3NH3)2HgI4

1992 ◽  
Vol 47 (1-2) ◽  
pp. 99-105
Author(s):  
Hiromitsu Terao ◽  
Tsutomu Okuda ◽  
Aya Minami ◽  
Takashi Matsumoto ◽  
Yoshio Takeda
Keyword(s):  
Temperature Dependence ◽  
Room Temperature ◽  
Isotope Effects ◽  
Molecular Motions ◽  
Resonance Frequencies ◽  
Wide Range ◽  
Large Asymmetry ◽  
Increasing Temperature ◽  
Asymmetry Parameters ◽  
Positive Frequency

AbstractThe 81Br and 127I NQR frequencies in (CH3NH3 ) 2HgBr4 and (CH3NH3 ) 2HgI4 , respectively, have been recorded from above 77 K to around room temperature. The resonance lines exist in a wide range of frequencies. An unusual temperature dependence of the resonance frequencies has been observed. Small 1H - 2D isotope effects have been observed between (CH3ND3 )2HgBr4 and (CH3NH3 ) 2HgBr4 . Both negative and positive frequency differences between the deuterated and the nondeuterated compound have been observed at 77 K. The relatively large asymmetry parameters in the iodine compound decrease with increasing temperature, indicating the existence of H-bonds. The present results are interpreted qualitatively by considering the effects of H-bonding, N - H • • • X, between the halogen atoms and the CH3NH3 ions which may undergo large molecular motions. It is suggested that not only frequency-lowering but also frequency-rising effects may be produced, depending on the direction of the H-bond, i.e., the angle between the Hg -X bond and the X • • • H bond.

scholarly journals Consumer Prices for Surgical Management of End-Stage Hallux Rigidus

2019 ◽  
Vol 4 (4) ◽  
pp. 2473011419S0007
Author(s):  
Niall A. Smyth ◽  
Vaishnavi Krishnan ◽  
Johnathon R. McCormick ◽  
Jonathan R. Kaplan ◽  
Amiethab A. Aiyer
Keyword(s):  
Metatarsophalangeal Joint ◽  
Hallux Rigidus ◽  
Treatment Modalities ◽  
Potential Cost ◽  
First Metatarsophalangeal Joint ◽  
Consumer Prices ◽  
Wide Range ◽  
Significant Difference ◽  
The Mean ◽  
End Stage

Category: Midfoot/Forefoot, Healthcare economics Introduction/Purpose: Hallux rigidus is the most prevalent arthritic condition of the foot. Treatment of end-stage disease traditionally consists of a first metatarsophalangeal joint (MTPJ) arthrodesis, however the use of a synthetic cartilage implant is becoming more common. With the high prevalence of disease and implementation of new treatment modalities, healthcare consumers should be aware of the costs associated with management. The purpose of this study was to determine access to the cost and variability in price of first MTPJ arthrodesis and synthetic cartilage implantation. Methods: Forty academic centers were contacted using a standardized patient script. The patient was a 59-year-old female who had failed conservative treatment of hallux rigidus. Each institution was contacted up to three times in an attempt to obtain a full bundled operative quote for a first MTPJ arthrodesis and synthetic cartilage implantation. Results: Twenty centers (50%) provided a quote for first MTPJ arthrodesis and 15 centers (38%) provided a quote for synthetic cartilage implantation. Only 14 centers (35%) were able to provide a quote for both procedures. The mean bundled price for MTPJ arthrodesis was $21,767 (range, $8,417 – $39,265). The mean bundled price for synthetic cartilage implantation was $21,546 (range, $4,903 – $74,145). There was no statistically significant difference between the bundled price for first MTPJ arthrodesis and synthetic cartilage implantation. Conclusion: There was limited availability of consumer prices for first MTPJ arthrodesis and synthetic implantation, therefore impeding healthcare consumers’ decision making. There was a wide range of quotes for both procedures, indicating potential cost savings.

scholarly journals Prospective comparison of chilled versus room temperature saline irrigation in alcohol-assisted photorefractive keratectomy

2013 ◽  
Vol 5 (2) ◽  
pp. 154-160 ◽  
Author(s):  
Marcus C Neuffer ◽  
YM Khalifa ◽  
M Moshirfar ◽  
MD Mifflin
Keyword(s):  
Ocular Surface ◽  
Room Temperature ◽  
Photorefractive Keratectomy ◽  
Spherical Equivalent ◽  
Saline Irrigation ◽  
Prospective Comparison ◽  
Significant Difference ◽  
Manifest Refraction ◽  
The Mean ◽  
Contralateral Eye

Introduction: Chilled saline is commonly used to irrigate the ocular surface after photorefractive keratectomy (PRK) and is often considered by the patients to be uncomfortable. Room temperature (non-chilled) saline may be a safe and less painful alternative. Objectives: To compare pain and visual outcomes after irrigating the ocular surface with chilled saline versus room temperature saline in alcohol assisted PRK. Materials and methods: In this prospective, single-masked, randomized, contralateral eye study, myopic eyes were treated with PRK. Immediately after laser ablation one eye was irrigated with chilled saline and the other with non-chilled saline. Primary outcomes measured were pain, haze, uncorrected (UCVA) and best-corrected (BCVA) visual acuities, and manifest refraction. Results: Each group comprised of 40 eyes. There was no significant difference in pain between the groups at any point during five days after surgery. At 6 months the mean UCVA was -0.08 logMAR ± .077 [SD] (20/17) and -0.07 ± .074 logMAR (20/17) in the chilled and non-chilled groups respectively (p =.35). Both groups achieved 95% UCVA of 20/20 or better. The manifest refraction spherical equivalent (MRSE) was -0.05 ± 0.21 D and -0.025 ± 0.27 D respectively (p = .79). There were no lines lost of BCVA and no haze observed. Similar outcomes were observed with regard to pain and vision in both groups. Conclusion: The use of room temperature saline irrigation during PRK appears to be safe and effective. Nepal J Ophthalmol 2013; 5(10): 154-160 DOI: http://dx.doi.org/10.3126/nepjoph.v5i2.8706

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