scholarly journals OBSERVATIONS BY ELECTRON MICROSCOPY ON CONTRACTION OF SKELETAL MYOFIBRILS INDUCED WITH ADENOSINETRIPHOSPHATE

1951 ◽  
Vol 94 (1) ◽  
pp. 9-20 ◽  
Author(s):  
Charles A. Ashley ◽  
Keith R. Porter ◽  
Delbert E. Philpott ◽  
George M. Hass
Keyword(s):  
Structural Changes ◽  
Contractile Response ◽  
Gradual Increase ◽  
Enzymatic Modification ◽  
Buffer Solution ◽  
Solution Ph ◽  
Apparent Increase ◽  
Mean Diameter ◽  
Parallel Arrangement ◽  
The Mean

Skeletal myofibrils isolated either by tryptic digestion at 0° C. or by a colloid mill and suspended in buffer solution (pH 7.0, µ; 0.154) containing 20 per cent glycerin and 0.0025 M adenosinetriphosphate at –5° C. contracted slowly and progressively when the temperature was raised above 0° C. Formalin fixation halted this contraction. With the aid of these procedures myofibrils in progressive stages of contraction were then studied with the electron microscope. Electron micrographs showed that uncontracted fibrils isolated by the colloid mill were structurally similar to those described by other workers. Treatment of fibrils with trypsin removed the Z bands and disorganized the I bands. This enzymatic modification of structure did not impair the contractile response. The principal structural changes during contraction consisted of a migration of dense material from the A band into the A-I junction or the Z band, a gradual increase in width of the fibril, a gradual decrease in length of sarcomeres, an apparent increase in the mean diameter of filaments, and a disorientation of these latter from their parallel arrangement.

scholarly journals Comparative characteristics of the manifestations of damage and reparative processes in the mucous membrane of the duodenum of rats under the conditions of skin burns and skin burns associated with diabetes

2020 ◽  
Vol 26 (2) ◽  
pp. 39-44
Author(s):  
I.A. Tymoshenko ◽  
L.M. Sokurenko ◽  
A.Ya. Yanchyshyn ◽  
V.A. Pastukhova
Keyword(s):  
Diabetes Mellitus ◽  
Mucous Membrane ◽  
Structural Changes ◽  
Burn Injury ◽  
Experimental Diabetes ◽  
Male Rats ◽  
Control Group ◽  
Experimental Diabetes Mellitus ◽  
Buffer Solution ◽  
Solution Ph

Currently, severe thermal injury is becoming one of the most important problems of practical medicine. Diabetes is also recognized as another global medical and social challenge of our century. The emergency situation for the treatment and prevention of the consequences of these pathologies is a consequence of the lack of a reliable theoretical basis for solving specific clinical problems regarding the course of burns, diabetes and their complications. The aim of the study is to establish the patterns of structural changes in the mucous membrane of the duodenum after burn injury of the skin of rats under conditions of experimental diabetes mellitus. The study was performed on 63 laboratory white adult male rats weighing 180-210 g, which were divided into 3 groups: intact animals, rats with skin burns and rats with skin burns on the background of diabetes. The model of experimental diabetes mellitus was reproduced by administering Streptozotocin to rats intraperitoneally once at a dose of 50 mg/kg, pre-dissolved in 0.1 M citrate buffer solution (pH=4.5). The control of the development of hyperglycemia in the experimental groups was the level of glucose in the blood 24.24±0.79 mmol/l. In the control group this index was 8.03±0.4 mmol/l. Rats with skin burns revealed destructive manifestations, which are accompanied by an active inflammatory reaction and corresponding necrotic changes, while rats with skin burns on the background of diabetes mellitus pathological processes are not just “summed up”, but in some way adaptively modified with the involvement of stress mechanisms of the endoplasmic reticulum and associated autophagy.

scholarly journals Collagenous Tissues upon Lithium Treatment: A Quantitative Ultrastructural Study

2004 ◽  
Vol 4 ◽  
pp. 605-621 ◽  
Author(s):  
Margaret Tzaphlidou
Keyword(s):  
Structural Changes ◽  
Lithium Treatment ◽  
Ultrastructural Level ◽  
Collagen Fibrils ◽  
Experimental Conditions ◽  
Banding Patterns ◽  
Rabbit Skin ◽  
Mean Diameter ◽  
The Mean ◽  
Collagenous Tissues

In this review, the influence of lithium treatment in mouse, rat, and rabbit skin, liver, bone, and aorta, as well as arachnoid and dura mater collagen fibrils, is examined using electron microscopy and image processing. Structural changes (fibril architecture and diameter) are detected at the ultrastructural level in specimens from all lithium-treated tissues. The overall collagen fibril architecture is disturbed as compared with specimens from normal species. The mean diameter values of treated collagen fibrils are significantly smaller than those from controls in all tissues examined. The banding patterns of fibrils are normal in all cases. Measurements by a computerized method of measuring axial periodicity of fibrils indicate no effect of lithium on this parameter. Computer analysis shows no differences in charged amino acid composition between lithium-treated and -untreated samples. Under the present experimental conditions, lithium can induce permanent structural collagen alterations.

Detection of Hepatitis a Virus in Drinking Water by Enzyme -Immunoassay Using Ultracentrifugation for Virus Concentration

1985 ◽  
Vol 17 (10) ◽  
pp. 39-41 ◽  
Author(s):  
A. Schnattinger
Keyword(s):  
Membrane Filtration ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Solid Phase ◽  
Phosphate Buffer Solution ◽  
Enzyme Linked Immunosorbent Assay ◽  
Virus Concentration ◽  
Buffer Solution ◽  
Solution Ph ◽  
Two Stage

Ten litres of tapwater were seeded with 200 µl (8×108 HAV particles) of a commercial (Organon Teknika) suspension of hepatitis A virus. Following WALTER and RÜDIGER (1981), the contaminated tapwater was treated with a two-stage technique for concentration of viruses from solutions with low virus titers. The two-stage technique consists of aluminium hydroxideflocculation (200 mg/l Al2(SO4)3. 18 H2O, pH 5,4-5,6) as first stage, the second stage of a lysis of aluminium hydroxidegel with citric acid/sodium citrate-buffer (pH 4,7; 1 ml/l sample), separation of viruses from the lysate by ultracentrifugation and suspension in 1 ml phosphate buffer solution (pH 7,2). A commercial solid phase enzyme-linked immunosorbent assay (ELISA) was used for the detection of HAV. HAV was detecterl in the 10.000:1 concentrates, but not in the seeded 101 samples. Approximately 4×108 of the inoculated 8×108 HAV particles were found in the 1 ml concentrates. The efficiency of detection is about 50%, the virus concentration 5000-fold. Although the percentage loss of HAV in comparison with concentration by means of membrane filtration is similar, the ultracentrifugation method yields a larger sample/concentrate ratio, so that smaller amounts of HAV can be detected more efficiently because of the smaller end-volume.

Development and Validation of Stability Indicating HPLC Method for the Determination of Impurities in the Sterile Mixture of Cefoperazone and Sulbactam

2019 ◽  
Vol 15 (7) ◽  
pp. 762-775
Author(s):  
Ramu Ivaturi ◽  
Thuttagunta Manikya Sastry ◽  
Satyaveni Sunkara
Keyword(s):  
Quantitative Estimation ◽  
Ammonium Hydroxide ◽  
Hplc Method ◽  
Forced Degradation ◽  
Buffer Solution ◽  
Solution Ph ◽  
Pharmaceutical Dosage Forms ◽  
Stability Indicating ◽  
Validation Parameters ◽  
Abdominal Infections

Background: Cefoperazone Sulbactam injection is a cephalosporin antibiotic with a β- lactamase inhibitor used in the treatment for intra abdominal infections, Urinary track infections, surgical infections, etc. The combination is not official in any of the pharmacopeia for their content and impurities determination. Introduction: The present study involves the development of a simple, rapid, accurate, sensitive and stability indicating RP-HPLC method for the quantitative estimation of Cefoperazone Sulbactam mixture and its impurities in bulk and pharmaceutical dosage forms. Methods: 0.005 M Tetrabutyl ammonium hydroxide buffer solution pH adjusted to 6.80 and Acetonitrile combination has been used in a gradient programme with a flow rate of 1.0 ml/min. The retention time of Cefoperazone and Sulbactam were observed at around 8.5 and 19.5 minutes respectively. The UV detection was carried out at a wavelength of 230 nm. The chromatographic separation was achieved using Waters xbridge C18-150*4.6 mm, 3.5 µm HPLC column. The method has been validated according to the current International Council for Harmonization (ICH) guidelines for the method validation parameters such as Specificity, linearity, range, accuracy, precision, robustness and sensitivity. Results: The validation results indicate that the method is specific, as the known impurities and other impurities formed during the forced degradation studies were not co-eluting with the main components. Moreover, all these impurities were found to be spectrally pure, proving the stability indicating power of the method. The linearity and range of the method is in the range of 0.01-150%, highly accurate (100.2%), precise (<1%) and robust. Conclusion: The proposed method was accurate and specific for the quantitative analysis of Cefoperazone and Sulbactam and their related impurities in the sterile mixture. Hence the proposed method can be used for the quantification of impurities in routine as well as stability analysis in the development as well as quality control laboratories.

Non-enzymatic determination of purine nucleotides using a carbon dot modified glassy carbon electrode

2019 ◽  
Vol 11 (30) ◽  
pp. 3866-3873 ◽  
Author(s):  
R. Karthikeyan ◽  
D. James Nelson ◽  
S. Abraham John
Keyword(s):  
Glassy Carbon ◽  
Low Cost ◽  
Phosphate Buffer Solution ◽  
Purine Nucleotides ◽  
Buffer Solution ◽  
Solution Ph ◽  
Carbon Dot ◽  
Enzymatic Determination ◽  
Sensitive Determination

Selective and sensitive determination of one of the purine nucleotides, inosine (INO) using a low cost carbon dot (CD) modified glassy carbon (GC) electrode in 0.2 M phosphate buffer solution (pH 7.2) was demonstrated in this paper.

Non-isothermal crystallization behavior of spinel crystals in FeO-SiO2-TiO2-V2O3-Cr2O3 slag

2018 ◽  
Vol 116 (1) ◽  
pp. 110
Author(s):  
Lixiong Shao ◽  
Jiang Diao ◽  
Wang Zhou ◽  
Tao Zhang ◽  
Bing Xie
Keyword(s):  
Cooling Rate ◽  
Crystallization Behavior ◽  
Crystal Size ◽  
Growth Mechanisms ◽  
Vanadium Slag ◽  
Growth Behaviour ◽  
Temperature Range ◽  
Chromium Spinel ◽  
Mean Diameter ◽  
The Mean

The growth behaviour of spinel crystals in vanadium slag with high Cr2O3 content was investigated and clarified by statistical analyses based on the Crystal Size Distribution (CSD) theory. The results indicate that low cooling rate and Cr2O3 content benefit the growth of spinel crystals. The chromium spinel crystals firstly precipitated and then acted as the heterogeneous nuclei of vanadium and titanium spinel crystals. The growth mechanisms of the spinel crystals at the cooling rate of 5 K/min consist two regimes: firstly, nucleation control in the temperature range of 1873 to 1773 K, in which the shapes of CSD curves are asymptotic; secondly, surface and supply control within the temperature range of 1773 to 1473 K, in which the shapes of CSD curves are lognormal. The mean diameter of spinel crystals increases from 3.97 to 52.21 µm with the decrease of temperature from 1873 to 1473 K.

The evolution of star formation in QSOs according to WISE

2020 ◽  
Vol 15 (S359) ◽  
pp. 33-34
Author(s):  
K. A. Cutiva-Alvarez ◽  
R. Coziol ◽  
J. P. Torres-Papaqui ◽  
H. Andernach ◽  
A. C. Robleto-Orús
Keyword(s):  
Star Formation ◽  
Gradual Increase ◽  
A Value ◽  
Star Formation Activity ◽  
The Mean ◽  
Lower Redshift

AbstractUsing WISE data, we calibrated the W2-W3 colors in terms of star formation rates (SFRs) and applied this calibration to a sample of 1285 QSOs with the highest flux quality, covering a range in redshift from z ˜ 0.3 to z ˜ 3.8. According to our calibration, the SFR increases continuously, reaching a value at z ˜ 3.8 about 3 times higher on average than at lower redshift. This increase in SFR is accompanied by an increase of the BH mass by a factor 100 and a gradual increase of the mean Eddington ratio from 0.1 to 0.3 up to z ˜ 1.5 – 2.0, above which the ratio stays constant, despite a significant increase in BH mass. Therefore, QSOs at high redshifts have both more active BHs and higher levels of star formation activity.

scholarly journals Electro-Polymerized Titan Yellow Modified Carbon Paste Electrode for the Analysis of Curcumin

Surfaces ◽  
2021 ◽  
Vol 4 (3) ◽  
pp. 191-204
Author(s):  
Edwin S. D’Souza ◽  
Jamballi G. Manjunatha ◽  
Chenthattil Raril ◽  
Girish Tigari ◽  
Huligerepura J. Arpitha ◽  
...  
Keyword(s):  
Carbon Paste Electrode ◽  
Limit Of Detection ◽  
Phosphate Buffer Solution ◽  
Modified Carbon Paste Electrode ◽  
Carbon Paste ◽  
Buffer Solution ◽  
Solution Ph ◽  
Real Sample Analysis ◽  
Titan Yellow ◽  
Paste Electrode

A modest, efficient, and sensitive chemically modified electrode was fabricated for sensing curcumin (CRC) through an electrochemically polymerized titan yellow (TY) modified carbon paste electrode (PTYMCPE) in phosphate buffer solution (pH 7.0). Cyclic voltammetry (CV) linear sweep voltammetry (LSV) and differential pulse voltammetry (DPV) approaches were used for CRC detection. PTYMCPE interaction with CRC suggests that the electrode exhibits admirable electrochemical response as compared to bare carbon paste electrode (BCPE). Under the optimized circumstances, a linear response of the electrode was observed for CRC in the concentration range 2 × 10−6 M to 10 × 10−6 M with a limit of detection (LOD) of 10.94 × 10−7 M. Moreover, the effort explains that the PTYMCPE electrode has a hopeful approach for the electrochemical resolution of biologically significant compounds. Additionally, the proposed electrode has demonstrated many advantages such as easy preparation, elevated sensitivity, stability, and enhanced catalytic activity, and can be successfully applied in real sample analysis.

scholarly journals POS1018 IMPORTANCE OF LATERAL SPINE VIEW IN DXA BONE DENSITOMETRY IN PATIENTS WITH SPONDYLOARTHRITIS

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 776.3-777
Author(s):  
S. Miri ◽  
H. Ferjani ◽  
K. Maatallah ◽  
A. Kasraoui ◽  
D. Kaffel ◽  
...  
Keyword(s):  
Femoral Neck ◽  
Structural Changes ◽  
Age Of Onset ◽  
Posterior Part ◽  
Lateral View ◽  
Mineral Density ◽  
Lateral Spine ◽  
Male Predominance ◽  
T Score ◽  
The Mean

Background:Osteoporosis is an increasingly important health problem among patients with spondyloarthritis (SPA). The Measure of Bone Mineral Density BMD is routinely carried out in an anteroposterior (AP) view of the spine. However, the syndesmophytes, ligaments calcifications, and the posterior part of vertebrae affect AP scanning. A lateral spine view is a more sensitive tool in assessing bone loss in trabecular bone.Objectives:We aimed to evaluate the association between lateral lumbar DXA and syndesmophyte grading in patients with SPA.Methods:We conducted a retrospective study including 75 patients with SPA. Bone density of the hip and lumbar spine was measured with a GE Lunar Prodigy Advance Bone Densitometer equipment. All patients had lumbar lateral, AP, and proximal femur DXA scans. The T-score, which measures the difference between a patient’s BMD and young-normal subjects, was computed and age-matched.Results:The mean age of the patients was 36±11 years. Male predominance was noted with a sex ratio of 4.76. The mean BMI was 25±5 kg/m2. Eight percent were obese. Fifty-two percent had Vitamin D deficiency.Forty-eight percent of the patients had axial SPA, while 52% had axial and peripheral symptoms.The mean age of onset was 27±7 years. Fifty-two percent of the patients had high inflammatory biomarkers. The BASDAI, ASDAS-VS, and ASDAS-CRP mean levels were respectively: 3.5±2.4, 3.1±0.9, and 3±0.8. The mean BASRI and mass were respectively 8 + 4.8 and 16.4 + 19.4. Analyses of T-score values obtained over the femoral neck revealed osteoporosis in 18.7% of the cases and osteopenia in 32% of the cases. On the other hand, analyses of AP, spine views revealed osteoporosis in 25.3% and osteopenia in 45.3% of patients (p=0.028, r=0.254). We detected the highest percentage of osteoporosis in lateral lumbar view and T-scores matched more closely with femoral neck values; osteoporosis in 29.3%, and osteopenia in 22.7% of the patients (p<10-3, r=0.562). BMD measured in AP, and lateral views were in good agreement (p<10-3, p=0.592). Age was inversely but not significantly associated with BMD in lateral (p=0.442, r=-0.09), AP (p=0.319, r=-0.117) and femoral neck projections (p=0.179, r=-0.157). Femoral neck BMD was associated with the activity of SPA (ASDAS vs (p=0.027, r= -0.295), and the mobility limitation BASMI (p=0.032, r= -0.247). Coxitis, BASRI, or mSASS were independent of BMD.Conclusion:We conclude that spine lateral view in DXA accurately measures BMD exceeding the AP spine views and femoral neck values. Therefore, structural changes do not affect this measurementDisclosure of Interests:None declared.

scholarly journals Bark proportion of Scots pine industrial wood

2021 ◽  
Author(s):  
Ferréol Berendt ◽  
Erik Pegel ◽  
Lubomir Blasko ◽  
Tobias Cremer
Keyword(s):  
Supply Chain ◽  
Scots Pine ◽  
Bark Thickness ◽  
Wood Supply ◽  
Volume Proportion ◽  
Bark Damage ◽  
Mass Proportion ◽  
Mean Diameter ◽  
The Mean

AbstractBark characteristics are not only used in the forest-wood supply chain, for example to calculate standing volumes, but also to transform wood volumes and masses. In this study, bark thickness, bark volume and bark mass were analyzed on the basis of 150 Scots pine discs, with a mean diameter of 13 cm. The mean double bark thickness was 3.02 mm, the mean bark volume proportion was 5.6% and mean bark mass proportion was 3.3%. Bark proportions were significantly affected by the log-specific variables ‘diameter over bark’, ‘proportion of bark damage’ and ‘double bark thickness’.

Sign in / Sign up

Export Citation Format

Share Document