scholarly journals THE PENETRATION OF AMMONIA INTO FROG MUSCLE

1944 ◽  
Vol 28 (1) ◽  
pp. 53-77 ◽  
Author(s):  
Wallace O. Fenn ◽  
Lorraine F. Haege ◽  
Eugenia Sheridan ◽  
John B. Flick
Keyword(s):  
Smooth Muscle ◽  
Blood Plasma ◽  
Chloride Content ◽  
Ringer Solution ◽  
Frog Muscle ◽  
Rate Of Penetration ◽  
Ringer’S Solution ◽  
Muscle Ph ◽  
And Control ◽  
Made In

1. A study was made of the electrolyte changes which occur when frog muscles are immersed in a Ringer solution with 1/5 of the Na replaced by NH4Cl. Analyses were made in the solution and in the muscles for K and NH3, and the muscles were also analyzed for Cl, HCO3, and Na. Control muscles were immersed in normal Ringer's solution and similarly analyzed. 2. The amount of ammonia taken up was about equal to the K and Na lost. There was also a small increase in chloride content. The bicarbonate content was the same in both experimental and control muscles, indicating no change in the muscle pH due to the NH3 which penetrated. An increased loss of K due to the penetration of NH3 was also demonstrated by the use of radioactive K. 3. After 5 hours, the concentration of ammonia per gram of muscle is about the same as the concentration in the solution. After 4 or 5 days, the concentration in the muscle is about 1.5 times that in the solution. The inside to outside NH3 ratio is about equal to the corresponding H ion ratio, but is much less than the K ratio. 4. The rate of penetration of the NH3 is increased by a rise of temperature, by stirring the solution, and by decrease in the concentration of Na, K, Ca, or Mg in the solution; it is decreased by increasing the size of the muscles or by killing them with chloroform or boiling. 5. Liver, smooth muscle, skin, and kidney, in a few experiments, behaved much like muscle except that there was a formation of urea in the case of liver. 6. The injection of NH4Cl into anesthetized cats causes an increase in the level of K in the blood plasma.

An Efficient Approach for Modeling and Control of a Quadrotor

2016 ◽  
Vol 4 (2) ◽  
pp. 1-16
Author(s):  
Ahmed S. Khusheef
Keyword(s):  
Pid Control ◽  
Control Method ◽  
Mechanical Design ◽  
Loop Control ◽  
Modeling And Control ◽  
Loop Control System ◽  
And Control ◽  
Close Loop Control ◽  
Close Loop Control System ◽  
Made In

 A quadrotor is a four-rotor aircraft capable of vertical take-off and landing, hovering, forward flight, and having great maneuverability. Its platform can be made in a small size make it convenient for indoor applications as well as for outdoor uses. In model there are four input forces that are essentially the thrust provided by each propeller attached to each motor with a fixed angle. The quadrotor is basically considered an unstable system because of the aerodynamic effects; consequently, a close-loop control system is required to achieve stability and autonomy. Such system must enable the quadrotor to reach the desired attitude as fast as possible without any steady state error. In this paper, an optimal controller is designed based on a Proportional Integral Derivative (PID) control method to obtain stability in flying the quadrotor. The dynamic model of this vehicle will be also explained by using Euler-Newton method. The mechanical design was performed along with the design of the controlling algorithm. Matlab Simulink was used to test and analyze the performance of the proposed control strategy. The experimental results on the quadrotor demonstrated the effectiveness of the methodology used.

scholarly journals Microbial-Driven Stabilisation of Archaeological Iron Artefacts

2021 ◽  
Vol 2 (2) ◽  
pp. 274-292
Author(s):  
Sarah James ◽  
Edith Joseph
Keyword(s):  
Health And Safety ◽  
Chloride Content ◽  
Key Factors ◽  
Passivation Layers ◽  
Archaeological Iron ◽  
Initial Results ◽  
Sulphur Species ◽  
Partial Success ◽  
Made In

The instability of iron artefacts is rooted in salt contamination during burial and damages associated with exposure to alternative oxygen levels and high relative humidity once excavated. While a combination of chemical and mechanical treatments is utilised to remove the harmful ions (chlorides, sulphur species) and excess bulky corrosion products, these methods can be hazardous for conservation staff’s health, have limited success, or require extensive treatment times. Bio-based treatments provide a potentially greener alternative for removing damaging corrosion and creating biogenic mineral passivation layers, thus remediating concerns over costs, duration, and health and safety. Pseudomonas putida mt-2 (KT2440) is capable of utilising iron under certain conditions and for phosphating mild steel; however, applications have not been made in the cultural heritage sector. To address the potential of using bacteria for conservation purposes, Pseudomonas was assessed for both the bioremediation of salt contaminates and the production of a passivation layer suitable for iron artefacts, with specific conservation concerns in mind. Key factors for optimisation include the role of agitation, chloride content, and oxygen content on bacterial growth and biomineralisation. The initial results indicate a growth preference, not reliance, for NaCl and agitation with partial success of bioconversion of a mineral source.

scholarly journals Diagnosis and Therapeutic Management of Liver Fibrosis by microRNA

2021 ◽  
Vol 22 (15) ◽  
pp. 8139
Author(s):  
Tomoko Tadokoro ◽  
Asahiro Morishita ◽  
Tsutomu Masaki
Keyword(s):  
Liver Fibrosis ◽  
Viral Infections ◽  
Primary Biliary Cholangitis ◽  
Medical Need ◽  
Key Factor ◽  
Complications Of Cirrhosis ◽  
And Control ◽  
Functional Rnas ◽  
Remarkable Progress ◽  
Made In

Remarkable progress has been made in the treatment and control of hepatitis B and C viral infections. However, fundamental treatments for diseases in which liver fibrosis is a key factor, such as cirrhosis, alcoholic/nonalcoholic steatohepatitis, autoimmune hepatitis, primary biliary cholangitis, and primary sclerosing cholangitis, are still under development and remain an unmet medical need. To solve this problem, it is essential to elucidate the pathogenesis of liver fibrosis in detail from a molecular and cellular perspective and to develop targeted therapeutic agents based on this information. Recently, microRNAs (miRNAs), functional RNAs of 22 nucleotides, have been shown to be involved in the pathogenesis of liver fibrosis. In addition, extracellular vesicles called “exosomes” have been attracting attention, and research is being conducted to establish noninvasive and extremely sensitive biomarkers using miRNAs in exosomes. In this review, we summarize miRNAs directly involved in liver fibrosis, miRNAs associated with diseases leading to liver fibrosis, and miRNAs related to complications of cirrhosis. We will also discuss the efficacy of each miRNA as a biomarker of liver fibrosis and pathology, and its potential application as a therapeutic agent.

Elevated levels of activin A in clinical and experimental pulmonary hypertension

2009 ◽  
Vol 106 (4) ◽  
pp. 1356-1364 ◽  
Author(s):  
Arne Yndestad ◽  
Karl-Otto Larsen ◽  
Erik Øie ◽  
Thor Ueland ◽  
Camilla Smith ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Transforming Growth Factor ◽  
Experimental Studies ◽  
Plasminogen Activator Inhibitor ◽  
Muscle Cells ◽  
Activin A ◽  
Plasminogen Activator Inhibitor 1 ◽  
And Control

Activin A, a member of the transforming growth factor (TGF)-β superfamily, is involved in regulation of tissue remodeling and inflammation. Herein, we wanted to explore a role for activin A in pulmonary hypertension (PH). Circulating levels of activin A and its binding protein follistatin were measured in patients with PH ( n = 47) and control subjects ( n = 14). To investigate synthesis and localization of pulmonary activin A, we utilized an experimental model of hypoxia-induced PH. In mouse lungs, we also explored signaling pathways that can be activated by activin A, such as phosphorylation of Smads, which are mediators of TGF-β signaling. Possible pathophysiological mechanisms initiated by activin A were explored by exposing pulmonary arterial smooth muscle cells in culture to this cytokine. Elevated levels of activin A and follistatin were found in patients with PH, and activin A levels were significantly related to mortality. Immunohistochemistry of lung autopsies from PH patients and lungs with experimental PH localized activin A primarily to alveolar macrophages and bronchial epithelial cells. Mice with PH exhibited increased pulmonary levels of mRNA for activin A and follistatin in the lungs, and also elevated pulmonary levels of phosphorylated Smad2. Finally, we found that activin A increased proliferation and induced gene expression of endothelin-1 and plasminogen activator inhibitor-1 in pulmonary artery smooth muscle cells, mediators that could contribute to vascular remodeling. Our findings in both clinical and experimental studies suggest a role for activin A in the development of various types of PH.

Smooth Muscle Contraction: Recent Advances

1994 ◽  
Vol 72 (11) ◽  
pp. 1317-1319
Author(s):  
Newman L. Stephens
Keyword(s):  
Smooth Muscle ◽  
Muscle Contraction ◽  
Myosin Light Chain ◽  
Kinase Activity ◽  
Smooth Muscle Contraction ◽  
Recent Advances ◽  
Regulation Of Contraction ◽  
Muscle Biochemistry ◽  
Remarkable Progress ◽  
Made In

Research in smooth muscle contraction has shown remarkable progress over the last 5 years. Striking advances have been made in the areas of biochemical regulation of contraction, centering on myosin light chain kinase activity, and of biophysical delineation of the contractile process at the actomyosin level by use of the newly developed motility assay. The purpose of the symposium held at Minaki, Ont., was to obtain a comprehensive reporting of the recent advances made in the area of smooth muscle contraction. Specifically, advances in the areas of biophysics of contraction, energetics, and contractile and regulator proteins (including the interesting newcomers caldesmon and calponin) and the changes that occur in pathophysiological entities such as asthma, hypertension, anaphylactic shock, high-altitude hypoxia, and persistent pulmonary hypertension of the newborn were presented.Key words: smooth muscle biophysics, smooth muscle biochemistry, energetics of smooth muscle, pathophysiology of smooth muscle.

Postscript: prescribing for acute diarrhea (30 December 1983, p 101–4)

1984 ◽  
Vol 22 (16) ◽  
pp. 64-64
Keyword(s):  
Acute Diarrhea ◽  
Clinical Presentation ◽  
Health Workers ◽  
Teaching Tool ◽  
London School ◽  
Infectious Agents ◽  
Basic Information ◽  
Professional Health ◽  
And Control ◽  
Made In

A CHART – Most of the points made in our article are also summarised in an information chart “Coping with Diarrhoea”, produced last year by the Ross Institute. It is intended as a teaching tool for professional health workers involved in the clinical management of diarrhoea, and gives basic information on clinical presentation, treatment, epidemiology and control of the most common agents of diarrhoea. A second chart summarises scientific knowledge of the major infectious agents of diarrhoea, and is intended for reference. The charts can be obtained from Miss S. O’Driscoll, Ross Institute, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT (cost £1 for the first and £2 for the second chart).

Effect of Hypertonicity on Augmentation and Potentiation and on Corresponding Quantal Parameters of Transmitter Release

1999 ◽  
Vol 81 (3) ◽  
pp. 1428-1431 ◽  
Author(s):  
Hong Cheng ◽  
Michael D. Miyamoto
Keyword(s):  
Nerve Stimulation ◽  
Transmitter Release ◽  
Ringer Solution ◽  
Hypertonic Solution ◽  
Repetitive Nerve Stimulation ◽  
Quantal Transmitter Release ◽  
Before And After ◽  
Miniature Endplate Potentials ◽  
Endplate Potentials ◽  
Made In

Effect of hypertonicity on augmentation and potentiation and on corresponding quantal parameters of transmitter release. Augmentation and (posttetanic) potentiation are two of the four components comprising the enhanced release of transmitter following repetitive nerve stimulation. To examine the quantal basis of these components under isotonic and hypertonic conditions, we recorded miniature endplate potentials (MEPPs) from isolated frog ( Rana pipiens) cutaneous pectoris muscles, before and after repetitive nerve stimulation (40 s at 80 Hz). Continuous recordings were made in low Ca2+ high Mg2+ isotonic Ringer solution, in Ringer that was made hypertonic with 100 mM sucrose, and in wash solution. Estimates were obtained of m (no. of quanta released), n (no. of functional release sites), p (mean probability of release), and vars p (spatial variance in p), using a method that employed MEPP counts. Hypertonicity abolished augmentation without affecting potentiation. There were prolonged poststimulation increases in m, n,and p and a marked but transient increase in vars p in the hypertonic solution. All effects were completely reversed with wash. The time constants of decay for potentiation and for vars p were virtually identical. The results are consistent with the notion that augmentation is caused by Ca2+ influx through voltage-gated calcium channels and that potentiation is due to Na+-induced Ca2+ release from mitochondria. The results also demonstrate the utility of this approach for analyzing the dynamics of quantal transmitter release.

scholarly journals Extracorporal modified ascitic fluid reinfusion in treatment of resistant ascites in liver cirrhosis

2017 ◽  
Vol 176 (3) ◽  
pp. 32-37
Author(s):  
I. E. Onnintsev ◽  
S. Ya. Ivanusa ◽  
A. V. Khokhlov ◽  
A. A. Sokolov ◽  
A. V. Yankovskiy
Keyword(s):  
Liver Cirrhosis ◽  
Portal Hypertension ◽  
Blood Plasma ◽  
Ascitic Fluid ◽  
Intravenous Infusion ◽  
Sodium Excretion ◽  
Albumin Level ◽  
New Method ◽  
Diuretic Resistance ◽  
Made In

OBJECTIVE. The aim of the study was to estimate the efficacy of new method of reinfusion of extracorporeal modified ascitic fluid in therapy of diuretic resistance ascites in patients with liver cirrhosis and portal hypertension syndrome. MATERIAL AND METHODS. An analysis of treatment was made in 83 patients, who underwent laparocentesis and ascitic fluid evacuation. The patients were divided into two groups. Laparocentesis and fractional evacuation of ascitic fluid were carried out for the patients of the first group (n=40). This procedure was followed by intravenous infusion of 25 % albumin (10 g of albumin on each 2 litres of removed fluid) in order to make up losses of protein. Laparocentesis and ascitic fluid evacuation with following extracorporal processing and reinfusion were performed for the second group of patients (n=43). RESULTS. There was noted an increase of day diuresis from (620,0 ± 110,0) ml to (2,2 ± 0,4) l compared with the first group from (780 ± 80) ml to (1,2 ± 0,5) l and rise of sodium excretion (132 ± 7) mmol/l compared with the first group - (120 ± 6) mmol/l. An average molecular peptide concentration was decreased in blood plasma to (0,254 ± 0,098) units in the second group and it counted (0,298 ± 0,045) units in the first group. CONCLUSIONS. Reinfusion of extracorporeal modified ascitic fluid was more effective than conventional correction of albumin level and electrolytes disturbances against a background of ascitic fluid evacuation.

scholarly journals Synthesis of novel heterocyclic Quinolone compound for anti -tubercular activity

2018 ◽  
Vol 4 (3) ◽  
pp. 44-49
Author(s):  
Rahul K. Godge ◽  
Rahul Kunkulol
Keyword(s):  
Control Strategies ◽  
Secondary Amines ◽  
Organic Reaction ◽  
Severe Problem ◽  
Mycobacterium Tuberculosis H37rv ◽  
Monitoring Tools ◽  
H37rv Strain ◽  
And Control ◽  
Quinolone Derivatives ◽  
Made In

In last few decades, though significant progress has been made in the treatment and control strategies of tubercular infections by introducing new diagnostic and monitoring tools and combination therapy, it still continues to be severe problem. The need of study was only because of there are many drugs in market to treat infection but most of the drugs are showing resistance because of the same it is difficult to treat the infection. In this study we chosen quinolone nucleus for study and over it.  Thus with the aim of developing novel molecule with improved potency for treating Mycobacterium tuberculosis H37Rv strain infections and with decreased probability of developing drug resistance. Methodology: The synthesis of Quinolone derivatives, starting from substituted aniline and ethyl acetoacetate, by conventional organic reaction and results of investigations of their anti-mycobacterial activity. Results: MICs of the synthesized compounds are compared with existing drugs Cytotoxicity. The substituted quinolones are synthesized by taking mixture of 7-substituted-2-(3-chloro-2-oxopropyl) quinolin-4(1H)-one and different secondary amines.  Many compounds have shown promising activity while some were inactive. Conclusion: It was found that Compound A1, A3, B1, B3, have shown promising anti tubercular activity whereas compound A2, A4,B2,B4 were showing moderate anti tubercular activity  against std. Streptomycin. 

scholarly journals Asthmatic Bronchial Matrices Determine the Gene Expression and Behavior of Smooth Muscle Cells in a 3D Culture Model

2021 ◽  
Vol 2 ◽  
Author(s):  
Selma Ben Hamouda ◽  
Maria Angélica Miglino ◽  
Gustavo de Sá Schiavo Matias ◽  
Guy Beauchamp ◽  
Jean-Pierre Lavoie
Keyword(s):  
Gene Expression ◽  
Smooth Muscle ◽  
Control Cell ◽  
3D Culture ◽  
Matrix Group ◽  
Cell Phenotype ◽  
Cell Control ◽  
Control Matrix ◽  
And Control

Asthma is associated with increased deposition and altered phenotype of airway smooth muscle (ASM) cells. However, little is known about the processes responsible for these changes. It has been suggested that alterations of the extracellular matrix (ECM) contribute to the remodeling of ASM cells in asthma. Three-dimensional matrices allow the in vitro study of complex cellular responses to different stimuli in a close-to-natural environment. Thus, we investigated the ultrastructural and genic variations of ASM cells cultured on acellular asthmatic and control bronchial matrices. We studied horses, as they spontaneously develop a human asthma-like condition (heaves) with similarities to chronic pulmonary changes observed in human asthma. Primary bronchial ASM cells from asthmatic (n = 3) and control (n = 3) horses were cultured on decellularized bronchi from control (n = 3) and asthmatic (n = 3) horses. Each cell lineage was used to recellularize six different bronchi for 41 days. Histomorphometry on HEPS-stained-recellularized matrices revealed an increased ASM cell number in the control cell/control matrix (p = 0.02) and asthmatic cell/control matrix group (p = 0.04) compared with the asthmatic cell/asthmatic matrix group. Scan electron microscopy revealed a cell invasion of the ECM. While ASM cells showed high adhesion and proliferation processes on the control ECM, the presence of senescent cells and cellular debris in the asthmatic ECM with control or asthmatic ASM cells suggested cell death. When comparing asthmatic with control cell/matrix combinations by targeted next generation sequencing, only AGC1 (p = 0.04), MYO10 (p = 0.009), JAM3 (p = 0.02), and TAGLN (p = 0.001) were differentially expressed out of a 70-gene pool previously associated with smooth muscle remodeling. To our knowledge, this is the first attempt to evaluate the effects of asthmatic ECM on an ASM cell phenotype using a biological bronchial matrix. Our results indicate that bronchial ECM health status contributes to ASM cell gene expression and, possibly, its survival.

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