Death rates of bacterial spores: nonlinear survivor curves

1975 ◽  
Vol 21 (10) ◽  
pp. 1464-1467 ◽  
Author(s):  
Youn W. Han
Keyword(s):  
Heat Resistance ◽  
Bacillus Cereus ◽  
Saline Solution ◽  
Physiological Saline ◽  
Bacterial Spores ◽  
Death Rates ◽  
Physiological Saline Solution ◽  
Spore Population

Nonlinear survivor curves were obtained when spores of Bacillus cereus were heated in physiological saline solution. Curvilinear survivor curves did not appear to be caused by experimental artifacts but by the heterogeneity of spore population with regard to heat resistance.

Death rates of bacterial spores: mathematical models

1976 ◽  
Vol 22 (2) ◽  
pp. 295-300 ◽  
Author(s):  
Youn W. Han ◽  
Hwe Ik Zhang ◽  
John M. Krochta
Keyword(s):  
Heat Resistance ◽  
Mathematical Models ◽  
Bacterial Spores ◽  
Heating Process ◽  
Death Rates ◽  
Spore Population ◽  
Survivor Curve

The concave survivor curves produced as a result of spore heterogeneity were analyzed to determine whether they were caused by innate characteristics of the spores or by the acquisition of heat resistance during the heating process. Mathematical models developed for the two hypotheses revealed that the concave survivor curve (on semi-log paper) caused by innate heterogeneity is parabolic and that caused by acquired heat resistance is exponential. The mathematical models were applied to several published survivor curves of different organisms, and heat resistance parameters and the cause of curvilinearity were determined. For the cases studied, the cause of curvilinearity appears to be acquisition of heat resistance rather than innate heterogeneity of spore population.

Sem Studies of Co-Cr-Mo Surgical Implant Alloy Corrosion Behavior

1982 ◽  
Vol 40 ◽  
pp. 520-521
Author(s):  
Ann Chidester Van Orden ◽  
John L. Chidester ◽  
Anna C. Fraker ◽  
Pei Sung
Keyword(s):  
Electron Microscopy ◽  
Corrosion Behavior ◽  
Anodic Polarization ◽  
Saline Solution ◽  
Saturated Calomel Electrode ◽  
Physiological Saline ◽  
X Ray ◽  
Physiological Saline Solution ◽  
Scanning Electron

The influence of small variations in the composition on the corrosion behavior of Co-Cr-Mo alloys has been studied using scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDX), and electrochemical measurements. SEM and EDX data were correlated with data from in vitro corrosion measurements involving repassivation and also potentiostatic anodic polarization measurements. Specimens studied included the four alloys shown in Table 1. Corrosion tests were conducted in Hanks' physiological saline solution which has a pH of 7.4 and was held at a temperature of 37°C. Specimens were mechanically polished to a surface finish with 0.05 µm A1203, then exposed to the solution and anodically polarized at a rate of 0.006 v/min. All voltages were measured vs. the saturated calomel electrode (s.c.e.).. Specimens had breakdown potentials near 0.47V vs. s.c.e.

Erythrophagocytosis by Entamoeba histolytica.- Ultrastructural Study

1972 ◽  
Vol 30 ◽  
pp. 156-157 ◽  
Author(s):  
Norberto Treviño ◽  
Alfredo Feria-Velasco ◽  
I. Ruiz de Chávez
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Entamoeba Histolytica ◽  
Ultrastructural Study ◽  
Saline Solution ◽  
Physiological Saline ◽  
Ultrastructural Level ◽  
Hot Plate ◽  
Physiological Saline Solution ◽  
Axenic Conditions

Although erythrophagocytosis by various species of Entamoeba is a well known phenomenon this has not yet been studied in detail at the ultrastructural level. The present work deals with the description of the incorporation process of erythrocytes by trophozoites of E. histolytica. For this study, trophozoites of E. histolytica, HK-9:NIH strain cultured in axenic conditions and washed human erythrocytes were placed on a hot plate at 37°C in physiological saline solution. After 5 minutes, 2.5% glutarldehyde was added and the samples were processed according to conventional techniques for electron microscopy.Based upon light microscopy studies on living trophozoites in contact with erythrocytes, it seems that erythrophagocytosis only takes place in one pole of the parasite.

Resection of bone by sagittal saw: Investigation of effects of blade speed, feed rate, and irrigation on temperature rise

2021 ◽  
pp. 095441192199948
Author(s):  
Ehsan Shakouri ◽  
Pezhman Ghorbani ◽  
Pedram Pourheidari ◽  
Saeed Fotuhi
Keyword(s):  
Temperature Rise ◽  
Feed Rate ◽  
Saline Solution ◽  
Physiological Saline ◽  
The State ◽  
Physiological Saline Solution ◽  
Allowable Range ◽  
Dry Conditions ◽  
Saw Blade ◽  
Oscillation Rate

Heat generation during bone cutting by sagittal saw may lead to temperature rise and possible incidence of thermal necrosis. The aim of the present research is to examine the effect of saw blade oscillation rate, blade feed rate, and irrigation by physiological saline solution on the bone temperature rise during sawing in order to determine the desired conditions for reducing the extent of thermal damage. For this purpose, empirical tests of bovine femur cutting were performed in 15 states, including five levels for the blade oscillation rate (10,000–18,000 cpm with 2000 cpm intervals) and three levels for the feed rate (10–30 mm.min−1 with 10 mm.min−1 intervals) for dry conditions; and five states, including five levels for the blade oscillation rate (10,000–18,000 cpm with 2000 cpm intervals) and one level in feed rate of 20 mm.min−1 for the irrigation conditions. The results indicated that the bone temperature rise had a direct relationship with the blade oscillation rate and an inverse relationship with its feed rate. In the state of no cooling, the minimum temperature rise (Δ T = 65.45°C) occurred at the blade speed of 10,000 cpm and feed rate of 30 mm.min−1, while in the state of sawing with irrigation, the temperature rise almost did not exceed the allowable range (Δ T ≤ 10°C). The results suggested that to lower the possibility of incidence of osteonecrosis in the bone resection by sagittal saw, cooling with physiological saline solution or application of the minimum blade oscillation rate and maximum feed rate is recommended.

scholarly journals A Study of the Diverse Races of Entamoeba histolytica distinguishable from one another by the dimensions of their Cysts

Parasitology ◽  
1918 ◽  
Vol 10 (3) ◽  
pp. 320-351 ◽  
Author(s):  
Clifford Dobell ◽  
Margaret W. Jepps
Keyword(s):  
Entamoeba Histolytica ◽  
Saline Solution ◽  
Practical Importance ◽  
Physiological Saline ◽  
E Coli ◽  
True Value ◽  
Apparent Loss ◽  
Physiological Saline Solution ◽  
Apparent Reduction ◽  
Pure Lines

1. Entamoeba histolytica Schaudinn (vel E. dysenteriae Councilman and Lafleur), the human dysentery amoeba, is a collective species. It comprises a number of distinct races, strains, or pure lines, distinguishable from one another by the size of the cysts which they produce.2. How many such distinct races exist is still undetermined; but we have demonstrated the existence of at least five.3. There is no evidence that the different races differ in their geographical distribution, or in any character save size.4. These races remain constant in character within a given host; and the dimensions of the cysts are not determined by the action of the host upon the parasite, since two different races may coexist side by side in the same host.5. Different values for the dimensions of the cysts are obtained when these are measured in different media. Taking the measurements of living cysts suspended in physiological saline solution as representing the true value, we find that the dimensions of cysts in iodine solution are approximately the same; but that cysts which have been suitably fixed, stained, and mounted in balsam, have undergone an apparent reduction of approximately 10% from the true diameter.6. The most suitable fixative for E. histolytica cysts we have found to be a modification of Schaudinn's fluid. (Saturated aqueous solution of corrosive sublimate, two parts; absolute alcohol, one part; glacial acetic acid, 4–5%.) Cysts fixed in this fluid undergo no measurable shrinkage or swelling in the process.7. The apparent loss of size observed in cysts which have been fixed, stained, and mounted in balsam, is due chiefly to the invisibility of the cyst wall in the mounting medium.8. It follows from what has been said above (5 and 6) that to obtain an approximately true value for the dimensions of the living cysts from measurements made upon those suitably fixed, stained, and mounted in balsam, these measurements should be multiplied by the factor 9. We find no evidence of the existence of a sexual dimorphism in the cysts belonging to a single race, such as has been described by Mathis and Mercier.10. Since cysts of E. histolytica may be found with all diameters from about 5μ. to about 20μ—a range overlapping or covering the dimensions of the cysts of the two common harmless intestinal amoebae of man (E. coli and E. nana) and of other cysts and cyst-like bodies occurring in human faeces—it is of considerable practical importance to recognize and distinguish the diverse races of E. histolytica which differ from one another in the dimensions of the cysts which they produce.

On intravenous infusions for blood loss

1927 ◽  
Vol 23 (3) ◽  
pp. 350-350
Author(s):  
N. D. Perumov
Keyword(s):  
Blood Loss ◽  
Saline Solution ◽  
Physiological Saline ◽  
Physiological Solution ◽  
Single Infusion ◽  
Intravenous Infusions ◽  
Physiological Saline Solution

The author believes that the infusion of gummy-arabic solution and the drip method of intravenous infusions of physiological saline solution are approximately equivalent and superior to a simple single infusion of physiological solution.

scholarly journals Comparison of the effectiveness and safety of intravenous and topical regimens of tranexamic acid in complex tibial plateau fracture: a retrospective study

2020 ◽  
Author(s):  
Zhimeng Wang ◽  
Yao Lu ◽  
Qian Wang ◽  
Leilei Song ◽  
Teng Ma ◽  
...  
Keyword(s):  
Blood Loss ◽  
Tibial Plateau ◽  
Adverse Reactions ◽  
Saline Solution ◽  
Physiological Saline ◽  
Wound Complications ◽  
Control Group ◽  
Vascular Events ◽  
Physiological Saline Solution ◽  
Plateau Fracture

Abstract Background Previous studies have demonstrated the effectiveness and safety of tranexamic acid (TXA) in orthopedic surgery. However, no study has investigated TXA in complex tibial plateau fracture surgery. Therefore, the purpose of this study was to confirm the safety and effectiveness of i.v. (intravenous) TXA and topical TXA.Material and methods This was a retrospective analysis of prospectively collected data. The control group received an equal amount of placebo (physiological saline solution); the i.v. group received 1.0 g TXA by intravenous injection before the tourniquet was inflated and before the surgical incision was closed, and the topical group received 3.0 g TXA in 75 mL of physiological saline solution 5 minutes prior to the final tourniquet release. Perioperative blood loss, vascular events, wound complications, and adverse reactions were compared among the three groups. The pain, knee function, and quality of life (QoL) assessments were based on their corresponding scoring systems.Results Baseline data were comparable for all groups. The i.v. group showed the best results for total blood loss (TBL) and hidden blood loss (HBL) (424.5 ± 49.4 mL and 219.3 ± 33.4 mL, respectively, all P values < 0.001). Patients in the i.v. group had lesser real Hb decrease than those in the control group (0.9 vs 1.5, P＜0.001) and topical group (0.9 vs 1.2, P = 0.026). The blood coagulation level as measured using fibrinolysis (D-dimer) was lower in the i.v. group than in the control and topical groups on POD1 and POD3; however, this difference was not significant; the fibrin-degradation products also showed a similar trend. Patients in the topical group experienced less pain than those in the control group on POD2, POD4, and PO6W. The VAS pain score was 3.6 vs. 4.4 (POD2, P＜0.05), 2.8 vs 3.3 (POD4, P＜0.05), and 2.1 vs. 2.6 (PO6W, P＜0.001) in the topical group vs control group, respectively. No significant differences were identified in vascular events, wound complications, adverse reactions, knee function, and QoL among the three groups.Conclusion To our knowledge, this is the first study that showed both i.v. TXA and topical TXA are safe and effective for complex tibial plateau fractures. The i.v. regimen effectively reduced blood loss during the perioperative period, whereas patients under the topical regimen had less vascular events, wound complications, and a lower incidence of adverse reactions compared to those in the i.v. group.

scholarly journals Comparison of Corrosion Resistance in Physiological Saline Solution of Two Austenitic Stainless Steels – 316LV and REX734

2017 ◽  
Vol 11 (2) ◽  
pp. 91-95 ◽  
Author(s):  
Eliza Romańczuk ◽  
Zbigniew Oksiuta
Keyword(s):  
Corrosion Resistance ◽  
Stainless Steels ◽  
Saline Solution ◽  
Austenitic Stainless Steels ◽  
Physiological Saline ◽  
Nacl Solution ◽  
Corrosion Properties ◽  
Physiological Saline Solution ◽  
Superior Corrosion Resistance ◽  
Lower Nickel

AbstractIn this work two austenitic stainless steels, REX734 and 316LV were tested in terms of their microstructure and corrosion properties. The REX734 is a newer generation stainless steel, with modified chemical composition, in comparison to the 316LV grade. Potentiodynamic study of corrosion resistance was conducted in physiological saline solution (0.9% NaCl solution). In spite of the similarities of microstructure, grain size and phase structure in both materials, the corrosion tests revealed that the REX734, with lower nickel and higher nitrogen content, had better corrosion resistance than 316LV. Repassivation potential in the REX734 was almost six times higher than for the 316LV steel. Superior corrosion resistance of the REX734 steel was also confirmed by surface observations of both materials, since bigger and more densely distributed pits were detected in 316LV alloy.

scholarly journals Ziziphus spina-christi Leaf Extract Suppressed Mercury Chloride-Induced Nephrotoxicity via Nrf2-Antioxidant Pathway Activation and Inhibition of Inflammatory and Apoptotic Signaling

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Rafa S. Almeer ◽  
Gadah Albasher ◽  
Fatimah Alotibi ◽  
Saud Alarifi ◽  
Daoud Ali ◽  
...  
Keyword(s):  
Leaf Extract ◽  
Saline Solution ◽  
Physiological Saline ◽  
Antioxidant Response ◽  
Renal Tissue ◽  
Protective Role ◽  
Control Group ◽  
Mercury Chloride ◽  
Beneficial Effects ◽  
Physiological Saline Solution

Exposure to heavy metals, including mercury chloride (HgCl2), is associated with severe health problems. This study was designed to investigate HgCl2-induced nephrotoxicity and evaluate the protective role of Ziziphus spina-christi leaf extract (ZSCLE). Four randomly selected groups containing seven rats were used. For a period of 28 days, the control group was administered 0.9% saline solution; the second group was administered 300 mg/kg ZSCLE; the third group was administered 0.4 mg/kg HgCl2 dissolved in 0.9% physiological saline solution; and the fourth group was administered an oral supplement of 300 mg/kg ZSCLE one hour after HgCl2 administration. HgCl2 intoxication resulted in Hg accumulation in renal tissue; decreases in body weight, kidney index, and glutathione content and superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase activities; increases in creatinine, urea, Kim-1 expression, lipid peroxidation, and nitric oxide production; suppression of the Nrf2-antioxidant response pathway; upregulation of Il1β, Tnfα, and Nos2; and potentiation of proapoptotic activity. ZSCLE exerted beneficial effects against mercury-induced renal toxicity and significantly reversed these alterations to near normal values. These effects resulted from its chelation and antioxidant, anti-inflammatory, and antiapoptotic activities. ZSCLE may prevent or minimize the pathological changes induced by mercury in the kidney.

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