Radioiodination and biodistribution of Leucurolysin-B isolated from Bothrops Leucurus in mice bearing Ehrlich

International Nuclear Information System (INIS)

Gabriel, L.M.; Soares, M.A.; Bicalho, M.S.; Santos, R.G.; Sanchez, E.O.F.; Silva, S.G.

2009-01-01

Integrins are family of heterodimeric cell surface adhesion receptors able to recognize and bind to proteins in the extracellular matrix (ECM). This recognition is mainly through the RGD domain present in both the cell surface as the protein in the ECM. Various integrins have been identified as regulators of tumor progression. The RGD domain is also found in some snake venoms named disintegrins. Disintegrins inhibit cell-matrix and a cell-cell interaction mediated by integrin and has been shown that these proteins are able to inhibit metastasis in processes dependent on integrin. The disintegrin-like (ECD), as well as RGD-disintegrin are also able to bind to cell surface integrins and inhibit their adherence to the natural ligands. Leucurolysin-B (Leuc-B) is a metalloproteinase class P-III isolated from Bothrops leucurus (BLV) and possesses a disintegrin-like domain (ECD). The goals of this work were to synthesize a radioactive probe analog to Leuc-B using radioiodine 125 I and evaluate the interaction of 125 I-Leuc-B in tumor cells through the study of biodistribution in animals bearing Ehrlich tumor.125I-Leuc-B was synthesized using lactoperoxidase with high yield (90%) and specific activity of 1.2x10-7Bq/mmol. It was observed that 125 I-Leuc-B had very fast clearance from the blood stream (T1/2= 0.01 h). Tumor uptake of 125I-Leuc-B gradually increased up to (2 min) and remained for a quite long period. The tumor/normal tissue uptake ratios of 125 I-Leuc-B were 1.77 (tumor/normal paw) and 8.44 tumor/skeletal muscle. The results suggest that 125 I-Leuc- B may constitute a good template for development of a tool for detection of solid tumors. (author)

Antitumor effectiveness of different amounts of electrical charge in Ehrlich and fibrosarcoma Sa-37 tumors

International Nuclear Information System (INIS)

Ciria, HC; Quevedo, MS; Cabrales, LB; Bruzón, RP; Salas, MF; Pena, OG; González, TR; López, DS; Flores, JM

2004-01-01

In vivo studies were conducted to quantify the effectiveness of low-level direct electric current for different amounts of electrical charge and the survival rate in fibrosarcoma Sa-37 and Ehrlich tumors, also the effect of direct electric in Ehrlich tumor was evaluate through the measurements of tumor volume and the peritumoral and tumoral findings. BALB/c male mice, 7–8 week old and 20–22 g weight were used. Ehrlich and fibrosarcoma Sa-37 cell lines, growing in BALB/c mice. Solid and subcutaneous Ehrlich and fibrosarcoma Sa-37 tumors, located dorsolaterally in animals, were initiated by the inoculation of 5 × 10 6 and 1 × 10 5 viable tumor cells, respectively. For each type of tumor four groups (one control group and three treated groups) consisting of 10 mice randomly divided were formed. When the tumors reached approximately 0.5 cm 3 , four platinum electrodes were inserted into their bases. The electric charge delivered to the tumors was varied in the range of 5.5 to 110 C/cm 3 for a constant time of 45 minutes. An additional experiment was performed in BALB/c male mice bearing Ehrlich tumor to examine from a histolological point of view the effects of direct electric current. A control group and a treated group with 77 C/cm 3 (27.0 C in 0.35 cm 3 ) and 10 mA for 45 min were formed. In this experiment when the tumor volumes reached 0.35 cm 3 , two anodes and two cathodes were inserted into the base perpendicular to the tumor long axis. Significant tumor growth delay and survival rate were achieved after electrotherapy and both were dependent on direct electric current intensity, being more marked in fibrosarcoma Sa-37 tumor. Complete regressions for fibrosarcoma Sa-37 and Ehrlich tumors were observed for electrical charges of 80 and 92 C/cm 3 , respectively. Histopathological and peritumoral findings in Ehrlich tumor revealed in the treated group marked tumor necrosis, vascular congestion, peritumoral neutrophil infiltration, an acute inflammatory

Use of raw Euphorbia tirucalli extract for inhibition of ascitic Ehrlich tumor

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Orlando José dos Santos

Full Text Available Objective: to evaluate the effect of the Euphorbia tirucalli hydroalcoholic extract (ETHE on the development of Ehrlich Tumor, in its ascitic form. Methods: we intraperitoneally inoculated 15 Swiss mice with 10.44 x 107 cells of Ehrlich Tumor and divided them in two groups one day after: ETHE Group (eight mice, treated with a dosage of 125 mg/kg/day of EHTE for five days; and Control Group (seven mice, treated only with 0.9% isotonic saline solution over the same period. The treatment was done by gavage. Ten days after inoculation, four mice from each group were sacrificed for quantification of tumor cell number, ascitic fluid volume and bone marrow cell number. The remaining animals were maintained to evaluate survival. Results: The ascitic fluid volume and the tumor cell number were decreased in the ETHE group when compared with the control group, but with no statistical significance. On the other hand, survival was higher in the ETHE group, as well as the number of bone marrow cells. Conclusion: Treatment with ETHE after inoculation of Ehrlich Tumor decreases its development and increases survival and the bone marrow cellularity, thus reducing the myelosuppression present in the Ehrlich Tumor bearing mice.

Antitumor effect of vitamin D-binding protein-derived macrophage activating factor on Ehrlich ascites tumor-bearing mice.

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Koga, Y; Naraparaju, V R; Yamamoto, N

1999-01-01

Cancerous cells secrete alpha-N-acetylgalactosaminidase (NaGalase) into the blood stream, resulting in deglycosylation of serum vitamin D3-binding protein (known as Gc protein), which is a precursor for macrophage activating factor (MAF). Incubation of Gc protein with immobilized beta-galactosidase and sialidase generates the most potent macrophage activating factor (designated GcMAF). Administration of GcMAF to cancer-bearing hosts can bypass the inactivated MAF precursor and act directly on macrophages for efficient activation. Therapeutic effects of GcMAF on Ehrlich ascites tumor-bearing mice were assessed by survival time and serum NaGalase activity, because serum NaGalase activity was proportional to tumor burden. A single administration of GcMAF (100 pg/mouse) to eight mice on the same day after transplantation of the tumor (5 x 10(5) cells) showed a mean survival time of 21 +/- 3 days for seven mice, with one mouse surviving more than 60 days, whereas tumor-bearing controls had a mean survival time of 13 +/- 2 days. Six of the eight mice that received two GcMAF administrations, at Day 0 and Day 4 after transplantation, survived up to 31 +/- 4 days whereas, the remaining two mice survived for more than 60 days. Further, six of the eight mice that received three GcMAF administrations with 4-day intervals showed an extended survival of at least 60 days, and serum NaGalase levels were as low as those of control mice throughout the survival period. The cure with subthreshold GcMAF-treatments (administered once or twice) of tumor-bearing mice appeared to be a consequence of sustained macrophage activation by inflammation resulting from the macrophage-mediated tumoricidal process. Therefore, a protracted macrophage activation induced by a few administrations of minute amounts of GcMAF eradicated the murine ascites tumor.

Acanthus ilicifolius plant extract prevents DNA alterations in a transplantable Ehrlich ascites carcinoma-bearing murine model.

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Chakraborty, Tridib; Bhuniya, Dipak; Chatterjee, Mary; Rahaman, Mosiur; Singha, Dipak; Chatterjee, Baidya Nath; Datta, Subrata; Rana, Ajay; Samanta, Kartick; Srivastawa, Sunil; Maitra, Sankar K; Chatterjee, Malay

2007-12-28

To investigate the chemopreventive efficacy of the Indian medicinal plant Acanthus ilicifolius L Acanthaceae in a transplantable Ehrlich ascites carcinoma (EAC)-bearing murine model. Male Swiss albino mice were divided into four groups: Group A was the untreated normal control; Group B was the EAC control mice group that received serial, intraperitoneal (ip) inoculations of rapidly proliferating 2 x 10(5) viable EAC cells in 0.2 mL of sterile phosphate buffered saline; Group C was the plant extract-treated group that received the aqueous leaf extract (ALE) of the plant at a dose of 2.5 mg/kg body weight by single ip injections, once daily for 10, 20 and 30 consecutive days following tumour inoculation (ALE control); and Group D was the EAC + ALE-treatment group. The chemopreventive potential of the ALE was evaluated in a murine model by studying various biological parameters and genotoxic markers, such as tumour cell count, mean survival of the animals, haematological indices, hepatocellular histology, immunohistochemical expression of liver metallothionein (MT) protein, sister-chromatid exchanges (SCEs), and DNA alterations. Treatment of the EAC-bearing mice with the ALE significantly (P decrement (P single-strand breaks (SSBs) by 38.53% (3.14 +/- 0.31 vs 1.93 +/- 0.23, P < 0.01) in EAC-bearing murine liver. Our data indicate that, ALE is beneficial in restoring haematological and hepatic histological profiles and in lengthening the survival of the animals against the proliferation of ascites tumour in vivo. Finally, the chemopreventive efficacy of the ALE is manifested in limiting MT expression and in preventing DNA alterations in murine liver. The promising results of this study suggest further investigation into the chemopreventive mechanisms of the medicinal plant A. ilicifolius in vivo and in vitro.

Polyphenon-E encapsulated into chitosan nanoparticles inhibited proliferation and growth of Ehrlich solid tumor in mice

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Azza I. Othman

2018-03-01

Full Text Available Limited bioavailability of green tea polyphenols hampered their delivery to tumor and hence therapeutic effectiveness. This study investigated the antitumor activity of polyphenon-E (PE encapsulated into chitosan nanoparticles (CSNPs in Ehrlich solid tumor in mice. CSNPs-PE, with a particle size of 53–69 nm showed 83% entrapment efficiency and a sustained release of PE in pH = 7.4 at 37 °C. The data demonstrated a higher percentage of released drug in case of less crosslinked formulations. Ehrlich ascites carcinoma (EAC cells (2.5 × 106/0.2 ml/mouse were injected subcutaneously in the back of mice. Oral administration of CSNPs-PE for 30 days produced a significant decrease in tumor volume (53% and weight (60% compared with free PE and voids CSNPs (72%. Compared with free PE and control, cell cycle revealed G0/G1 arrest associated with decrease in proliferating cell nuclear antigen (PCNA. In tumor tissue of CSNPs-PE treated mice, compared with free PE, there were; 1 induction of Bax and p53, 2 activation of caspases-3,-8 and -9, and CD95, 3 decrease in Bcl-2 expression of 4 inhibition of VEGF and CD31 expressions in tumor tissue. In conclusion, encapsulation of PE into CSNPs provided a good platform for cancer chemotherapy and raised existing application of different polyphenols for nanochemotherapy/prevention.

Protective role of coriandrum sativum oily extracts on ehrlich tumour bearing mice subjected to gamma irradiation

International Nuclear Information System (INIS)

El-Sayed Aly, S.M.

2000-01-01

This study was planned to evaluate the potency of coriandrum, sativum oily extract [in a dose of 1 mg/kg body weight; for six successive doses] as a chemopreventive agent against solid ehrlich tumour transplanted to the thigh of the left leg of mice subjected or not to gamma irradiation. The protective role of coriander oil was assessed through studying the level of serum phosphorus, calcium, prostaglandins, and anti-thyroid antibodies levels. Meanwhile, the content of cholesterol and triacylglycerols both in hepatic and tumor tissues were also measured. The levels of serum calcium ions revealed significant decline in the tested groups as compared with the control ones. Measurements of serum PGE 2 and anti-thyroid antibodies levels exhibited significant fluctuated changes as compared with the control levels. Serum phosphorus levels induced only non-significant changes. The contents of cholesterol both in hepatic and tumor tissues induced significant decline in the tested proups as compared with the control ones

Formation and utilization of acetoin, an unusual product of pyruvate metabolism by Ehrlich and AS30-D tumor mitochondria.

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Baggetto, L G; Lehninger, A L

1987-07-15

[14C]Pyruvate was rapidly non-oxidatively decarboxylated by Ehrlich tumor mitochondria at a rate of 40 nmol/min/mg of protein in the presence or absence of ADP. A search for decarboxylation products led to significant amounts of acetoin formed when Ehrlich tumor mitochondria were incubated with 1 mM [14C] pyruvate in the presence of ATP. Added acetoin to aerobic tumor mitochondria was rapidly utilized in the presence of ATP at a rate of 65 nmol/min/mg of protein. Citrate has been found as a product of acetoin utilization and was exported from the tumor mitochondria. Acetoin has been found in the ascitic liquid of Ehrlich and AS30-D tumor-bearing animals. These unusual reactions were not observed in control rat liver mitochondria.

The return of Ehrlich's 'Therapia magna sterilisans' and other Ehrlich concepts?. Series of papers honoring Paul Ehrlich on the occasion of his 150th birthday.

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Sörgel, F

2004-04-01

On March 14th of this year, the birthday of Paul Ehrlich, the great German researcher and 'founder of chemotherapy', returned for the 150th time. Interestingly, his later colleague Emil von Behring was born one day later in 1854. Both were coworkers in Robert Koch's laboratory and became Nobel Prize laureates (for their work in immunology), making great contributions to antiinfectious treatments. Emil von Behring's approach was through the use of immunological agents, while Ehrlich favored an approach of antiinfectious treatment by chemical agents. Through an ingenious concept that was a clear continuation of his early days in research with dyes, he found the first chemotherapeutic agents. From his dye work, he had concluded the following: if there are dyes that one can use to stain cells, why not develop pharmacological agents that, like stains, also attach to a structure in the living pathogen and kill them. He gave these agents the emotionally charged name 'magic bullets'. This introductory review will initiate a series of papers on the occasion of Ehrlich's 150th birthday and the 'World Conference on Dosing of Antiinfectives: Dosing the Magic Bullets', which is going to be held in Nürnberg, Germany, from September 9 to 11, 2004 (see www.ehrlich2004.org). Apart from the conference topic, this conference will also commemorate a real science giant of the last century and yet a modest human being whom, as Robert Koch put it, 'one had to like'. This article recalls Ehrlich's ingenious concepts, including modern syphilis treatment, one-dose treatment ('therapia magna sterilisans') of Helicobacter pylori infections and introduction of an arsenic compound, arsenic trioxide, as well as experiments and new exciting data on Congo red, a well-known 'non-Ehrlich dye'. Copyright 2004 S. Karger AG, Basel

Apigenin potentiates the antitumor activity of 5-FU on solid Ehrlich carcinoma: Crosstalk between apoptotic and JNK-mediated autophagic cell death platforms

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Gaballah, Hanaa H., E-mail: hanaahibishy@hotmail.com [Medical Biochemistry and Molecular Biology Department, Faculty of Medicine, Tanta University, Tanta, 3111 (Egypt); Gaber, Rasha A. [Medical Biochemistry and Molecular Biology Department, Faculty of Medicine, Tanta University, Tanta, 3111 (Egypt); Mohamed, Darin A. [Histopathology Department, Faculty of Medicine, Tanta University, Tanta, 3111 (Egypt)

2017-02-01

Background: Although 5- Fluorouracil (5-FU) has exhibited effectiveness against cancer, novel therapeutic strategies are needed to enhance its antitumor efficiency and modulate its cytotoxity. Apigenin, a flavonoid present in fruits and vegetables, is a potent dietary phytochemical effective in cancer chemoprevention. Aim: This study was undertaken to investigate the potential synergistic antitumor activity of apigenin and 5-FU on Solid Ehrlich carcinoma (SEC). Methods: Eighty Swiss albino male mice were divided into four equal groups: vehicle treated control SEC, SEC + 5-FU, SEC + apigenin, SEC + 5-FU + apigenin. Beclin-1 and caspases 3, 9 and JNK activities were estimated by ELISA; mRNA expression levels of the antiapoptotic gene Mcl-1 were estimated using quantitative real-time RT-PCR, while tissue malondialdehyde (MDA), glutathione peroxidase and total antioxidant capacity were evaluated spectrophotometrically. A part of the tumor was examined for histopathological and Ki-67 immunohistochemistry analysis. Results: 5-FU and/or apigenin caused significant increase in tissue levels of Beclin-1, caspases 3, 9 and JNK activities, MDA with significant decrease in tumor volume, Mcl-1expression, tissue glutathione peroxidase and total antioxidant capacity and alleviated the histopathological changes with significant decrease of Ki-67 proliferation index compared to vehicle treated SEC control group. In conclusion: The combination of 5-FU and apigenin had a greater effect than each of 5-FU or apigenin alone against solid Ehrlich carcinoma in mice. - Highlights: • Apigenin potentiated 5-FU cytotoxicity in EAC solid tumor models in vivo. • It acted via autophagy stimulation, downregulating MCL-1 and Ki-67 expression. • It caused JNK activation and ROS accumulation; resulted in tumor growth inhibition. • Apigenin can be used as a co-adjuvant agent in cancer therapy.

The synergistic effect between vanillin and doxorubicin in ehrlich ascites carcinoma solid tumor and MCF-7 human breast cancer cell line.

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Elsherbiny, Nehal M; Younis, Nahla N; Shaheen, Mohamed A; Elseweidy, Mohamed M

2016-09-01

Despite the remarkable anti-tumor activity of doxorubicin (DOX), its clinical application is limited due to multiple organ toxicities. Products with less side effects are therefore highly requested. The current study investigated the anti-cancer activities of vanillin against breast cancer and possible synergistic potentiation of DOX chemotherapeutic effects by vanillin. Vanillin (100mg/kg), DOX (2mg/kg) and their combination were administered i.p. to solid Ehrlich tumor-bearing mice for 21days. MCF-7 human breast cancer cell line was treated with vanillin (1 and 2mM), DOX (100μM) or their combination. Protection against DOX-induced nephrotoxicity was studied in rats that received vanillin (100mg/kg, ip) for 10days with a single dose of DOX (15mg/kg) on day 6. Vanillin exerted anticancer effects comparable to DOX and synergesticlly potentiated DOX anticancer effects both in-vivo and in-vitro. The anticancer potency of vanillin in-vivo was mediated via apoptosis and antioxidant capacity. It also offered an in-vitro growth inhibitory effect and cytotoxicity mediated by apoptosis (increased caspase-9 and Bax:Bcl-2 ratio) along with anti-metasasis effect. Vanillin protected against DOX-induced nephrotoxicity in rats. In conclusion, vanillin can be a potential lead molecule for the development of non-toxic agents for the treatment of breast cancer either alone or combined with DOX. Copyright © 2016. Published by Elsevier GmbH.

Effect of Bidens pilosa extract on renal functions and some tumor markers of Ehrlich Ascites Carcinoma bearing mice exposed to γ-radiation

International Nuclear Information System (INIS)

El-Kabany, H.; Ibrahim, S.I.

2013-01-01

The Ethanolic extract of Bidens pilosa (EtBP) was tested in Swiss albino mice transplanted with Ehrlich ascites carcinoma (EAC) and exposed to γ-radiation. EAC mice received intraperitoneal (i.p) 250 mg/kg body weight EtBP for nine days , 24hr after tumor inoculation. Mice exposed to 4 Gy γ-radiation 30 min after the first dose of EtBP. Seventy female mice were classified into 6 groups (15 mice in each group) as follows, control, mice treated with EtBP for 9 consecutive days, mice bearing EAC cells, EAC bearing mice treated with EtBP, 24 hour after tumor inoculation, EAC bearing mice and irradiated, and EAC bearing mice treated with EtBP and exposed to γ-radiation. Five animals from each group were sacrificed 18 hr after administration of the last EtBP dose. Blood and ascetic fluid were collected and kidneys were removed for biochemical and histopathological studies. The remaining animals were observed daily for recording survival percentage and body weight. Results showed that treatment of EAC bearing mice with EtBP and/or exposure to γ- radiation increased the survival percentage of the animals and decreased their body weight compared to EAC group. Inoculation of mice with EAC cells resulted in biochemical and histopathological changes leading to kidney damage. Animals of EAC bearing mice with EtBP and /or exposure to γ- radiation significantly restored the elevated levels of serum urea and creatinine, tumor necrosis factor-alpha (TNF-α), metalo matrix protein (mmp-2 and mmp9), also the elevated level of lipid peroxidation (MDA) in kidneys tissue, compared to EAC group. On the other hand, a significantly decline was observed in glutathione (GSH) and super oxide dismutase (SOD) contents in kidney tissue of EAC group. Treatment of EAC bearing mice with EtBP and/or exposure to γ-radiation resulted in increase GSH and SOD in kidney tissue and increased caspase-3 in ascetic fluid, comparing to EAC group. It could be concluded that EtBP through its antioxidant

Solid lubricant mass contact transfer technology usage for vacuum ball bearings longevity increasing

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Arzymatov, B.; Deulin, E.

2016-07-01

A contact mass transfer technological method of solid lubricant deposition on components of vacuum ball bearings is presented. Physics-mathematical model of process contact mass transfer is being considered. The experimental results of ball bearings covered with solid lubricant longevity in vacuum are presented. It is shown that solid lubricant of contact mass transfer method deposition is prospective for ball bearing longevity increasing.

The anti-tumor effect of bee honey in Ehrlich ascite tumor model of mice is coincided with stimulation of the immune cells.

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Attia, W Y; Gabry, M S; El-Shaikh, K A; Othman, G A

2008-01-01

Honey is thought to exhibit a broad spectrum of therapeutic properties including antibacterial, antifungal, cytostatic and anti-inflammatory activity and has been used for the treatment of gastric ulcers, burns, and for storage of skin grafts. The present study investigated the antitumor effect of bee honey against Ehrlich ascites tumor in mice and the possible mode of antitumor action. Peroral administration of mice with honey (10, 100 or 1000 mg/ 100 g BW) every other day for 4 weeks before intraperitoneal inoculation with Ehrlich ascites tumor (EAT, 1 x 10(6) cells) increased the number bone marrow cells as well as peritoneal macrophages, but not peripheral blood leukocytes nor splenocytes. The phagocytic function of macrophages as well as the T- and B-cell functions were also increased. Honey pre-treatment also recovered the total lipids, total proteins, as well as liver and kidney enzyme activities in EAT-bearing mice. In vitro studies on EAT cells demonstrated inhibitory effect of honey on tumor cell proliferation, viability % of tumor cells as well as the size of solid tumor. The present results indicate that the preventive treatment with honey is considerably effective against EAT in mice both in vivo and in vitro. The antitumor activity of honey may occur through the activation of macrophages, T-cells and B-cells.

Effects of daily treatment with a radioprotector WR-2721 on Ehrlich's ascites tumors in mice

International Nuclear Information System (INIS)

Ikebuchi, Makoto; Shinohara, Shigeo; Kimura, Hiroshi; Morimoto, Kunio; Shima, Akihiro

1981-01-01

Mice were injected daily with a radioprotector WR-2721 (S-2-[3-aminopropyl-amino]ethylphosphorothioic acid) after inoculation with Ehrlich's ascites tumor cells. Increases in weight of mice, volume of ascitic fluid and number of ascitic cells per mouse were reduced by the daily administration of 5 mg/mouse of the drug, indicating a suppressive effect of WR-2721 on growth of ascitic cells. But daily treatment with 5 mg/mouse of WR-2721 caused earlier death of tumor-bearing mice. (author)

Paul Ehrlich: the Nobel Prize in physiology or medicine 1908.

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Piro, Anna; Tagarelli, Antonio; Tagarelli, Giuseppe; Lagonia, Paolo; Quattrone, Aldo

2008-01-01

We wish to commemorate Paul Ehrlich on the centennial of his being awarded the Nobel Prize in Physiology or Medicine in 1908. His studies are now considered as milestones in immunology: the morphology of leukocytes; his side-chain theory where he defined the cellular receptor for first time; and his clarification of the difference between serum therapy and chemotherapy. Ehrlich also invented the first chemotherapeutic drug: compound 606, or Salvarsan. We have used some original documents from the Royal Society of London, where Ehrlich was a fellow, and from Leipzig University, where he took a degree in medicine.

Serum hepatic biochemistry and electrophoretic protein profile of healthy and Ehrlich tumor-bearing mice treated with extracts of Agaricus blazei Murill

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Durval Verçosa Junior

2016-04-01

Full Text Available Compounds isolated from Agaricus blazei Murill represent a group of promising natural immunomodulators for use in the treatment of neoplasms. We have evaluated the serum biochemical profile of healthy and Ehrlich tumor-bearing mice treated with different extracts of A. blazei. Total, supernatant, and polysaccharide extracts of A. blazei were obtained from suspensions (at acidic or neutral pH kept in a water bath at 60 °C or in an ultrasonic bath at 37 °C. After oral administering the extracts to mice for 21 days, blood samples were collected for determination of aspartate aminotransferase (AST, alanine aminotransferase (ALT, creatine kinase (CK, urea, total protein, albumin, globulins, and alpha-, beta- and gamma-globulin fractions. The presence of the tumor led to a significant increase in serum CK and AST activities and in the concentrations of total globulin and the gamma-globulin fraction, and to a decrease in the albumin and alpha2-globulin levels. The polysaccharide extracts of A. blazei reduced the serum AST and ALT activities, probably due to a hepatoprotective effect. In addition, polysaccharide and supernatant extracts inhibited the tumor-induced increase in gamma-globulin levels. Thus, the supernatant and polysaccharide fractions of the extract of A. blazei have potential for use in complementary antineoplastic treatments.

Downregulation of taurine uptake in multidrug resistant Ehrlich ascites tumor cells

DEFF Research Database (Denmark)

Poulsen, K A; Litman, Thomas; Eriksen, J

2002-01-01

In daunorubicin resistant Ehrlich ascites tumor cells (DNR), the initial taurine uptake was reduced by 56% as compared to the parental, drug sensitive Ehrlich cells. Kinetic experiments indicated that taurine uptake in Ehrlich cells occurs via both high- and low-affinity transporters. The maximal...... rate constant for the initial taurine uptake was reduced by 45% (high-affinity system) and 49% (low affinity system) in the resistant subline whereas the affinity of the transporters to taurine was unchanged. By immunoblotting we identified 3 TauT protein bands in the 50-70 kDa region. A visible...... reduction in the intensity of the band with the lowest molecular weight was observed in resistant cells. Quantitative RT-PCR indicated a significant reduction in the amount of taurine transporter mRNA in the resistant cells. Drug resistance in DNR Ehrlich cells is associated with overexpression of the mdr1...

An experimental study on the anti-Ehrlich ascites carcinoma effect of ...

African Journals Online (AJOL)

The objective of this paper was to study the anti-Ehrlich ascites carcinoma effect of purified toad venom extract and its mechanism. Mouse model of Ehrlich ascites carcinoma was established with cisplatin as the control to observe the inhibitory effect of purified toad venom extract on malignant peritoneal effusion in mice.

The Ehrlich Tumor Induces Pain-Like Behavior in Mice: A Novel Model of Cancer Pain for Pathophysiological Studies and Pharmacological Screening

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Cassia Calixto-Campos

2013-01-01

Full Text Available The Ehrlich tumor is a mammary adenocarcinoma of mice that can be developed in solid and ascitic forms depending on its administration in tissues or cavities, respectively. The present study investigates whether the subcutaneous plantar administration of the Ehrlich tumor cells induces pain-like behavior and initial pharmacological susceptibility characteristics. The Ehrlich tumor cells (1 × 104–107 cells induced dose-dependent mechanical hyperalgesia (electronic version of the von Frey filaments, paw edema/tumor growth (caliper, and flinches compared with the saline group between days 2 and 12. There was no difference between doses of cells regarding thermal hyperalgesia in the hot-plate test. Indomethacin (a cyclooxygenase inhibitor and amitriptyline hydrochloride (a tricyclic antidepressant treatments did not affect flinches or thermal and mechanical hyperalgesia. On the other hand, morphine (an opioid inhibited the flinch behavior and the thermal and mechanical hyperalgesia. These effects of morphine on pain-like behavior were prevented by naloxone (an opioid receptor antagonist treatment. None of the treatments affected paw edema/tumor growth. The results showed that, in addition to tumor growth, administration of the Ehrlich tumor cells may represent a novel model for the study of cancer pain, specially the pain that is susceptible to treatment with opioids, but not to cyclooxygenase inhibitor or to tricyclic antidepressant.

Transport of calcium ions by Ehrlich ascites-tumour cells.

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Landry, Y; Lehninger, A L

1976-01-01

Ehrlich ascites-tumour cells accumulate Ca2+ when incubated aerobically with succinate, phosphate and rotenone, as revealed by isotopic and atomic-absorption measurements. Ca2+ does not stimulate oxygen consumption by carefully prepared Ehrlich cells, but des so when the cells are placed in a hypo-osmotic medium. Neither glutamate nor malate support Ca2+ uptake in 'intact' Ehrlich cells, nor does the endogenous NAD-linked respiration. Ca2+ uptake is completely dependent on mitochondrial energy-coupling mechansims. It was an unexpected finding that maximal Ca2+ uptake supported by succinate requires rotenone, which blocks oxidation of enogenous NAD-linked substrates. Phosphate functions as co-anion for entry of Ca2+. Ca2+ uptake is also supported by extra-cellular ATP; no other nucleoside 5'-di- or tri-phosphate was active. The accumulation of Ca2+ apparently takes place in the mitochondria, since oligomycin and atractyloside inhibit ATP-supported Ca2+ uptake. Glycolysis does not support Ca2+ uptake. Neither free mitochondria released from disrupted cells nor permeability-damaged cells capable of absorbing Trypan Blue were responsible for any large fraction of the total observed energy-coupled Ca2+ uptake. The observations reported also indicate that electron flow through energy-conserving site 1 promotes Ca2+ release from Ehrlich cells and that extra-cellular ATP increase permeability of the cell membrane, allowing both ATP and Ca2+ to enter the cells more readily. PMID:988829

A Systems Approach to the Solid Lubrication of Foil Air Bearings for Oil-Free Turbomachinery

Science.gov (United States)

DellaCorte, Christopher; Zaldana, Antonio R.; Radil, Kevin C.

2002-01-01

Foil air bearings are self-acting hydrodynamic bearings which rely upon solid lubricants to reduce friction and minimize wear during sliding which occurs at start-up and shut-down when surface speeds are too low to allow the formation of a hydrodynamic air film. This solid lubrication is typically accomplished by coating the non-moving foil surface with a thin, soft polymeric film. The following paper introduces a systems approach in which the solid lubrication is provided by a combination of self lubricating shaft coatings coupled with various wear resistant and lubricating foil coatings. The use of multiple materials, each providing different functions is modeled after oil-lubricated hydrodynamic sleeve bearing technology which utilizes various coatings and surface treatments in conjunction with oil lubricants to achieve optimum performance. In this study, room temperature load capacity tests are performed on journal foil air bearings operating at 14,000 rpm. Different shaft and foil coating technologies such as plasma sprayed composites, ceramic, polymer and inorganic lubricant coatings are evaluated as foil bearing lubricants. The results indicate that bearing performance is improved through the individual use of the lubricants and treatments tested. Further, combining several solid lubricants together yielded synergistically better results than any material alone.

PGE from Octopus aegina Induces Apoptosis in Ehrlich's Ascites Carcinoma of Mice.

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Karthigayan, S; Balasubashini, M Sri; Balasubramanian, T; Somasundaram, S T

2007-01-01

ABSTRACT The present study was carried out to assess the antitumor effect of venomous peptide from the cephalopod Octopus aegina on Ehrlich's ascites carcinoma (EAC). Male albino Swiss mice were used in the present study. Four groups of animals were treated with three doses of the sublethal dose of venom, 15, 75, and 150 mug/kg body weight (intraperitoneal injection), along with the standard drug 5-fluorouracil (20 mg/kg b.w.). After 10 days of treatment, six animals from each group were sacrificed for the biochemical analysis and the rest were left to calculate the mean survival time. In EAC-bearing mice, mean lifespan, tumor volume, hemoglobin, red blood cells, and lymphocytes were significantly decreased when compared to the normal animals. While body weight, neutrophils, and viable tumor cell count were increased in the EAC-bearing mice, these changes were brought back to near normal levels in different treatment groups. The macromolecule concentration of peritoneal cells, such as DNA, RNA, and protein, were altered in the EAC-bearing mice and observed to be near normal in the treatment groups. The caspase-3 activity was significantly increased in the peritoneal cells of the treatment groups when compared to the EAC-bearing mice. The role of apoptotic cascade in EAC cell death was confirmed by the DNA fragmentation on agarose gel. Apart from the antitumor effect, octopus venom reduced the tumor burden on the liver and altered the changes in the activities of alanine transaminase (ALT), aspartate transaminase (AST), and alkaline phosphatase (ALP). Therefore, the venom from O. aegina has a potential antitumor effect on the EAC-bearing mice.

Some genetic profiles in liver of Ehrlich ascites tumor-bearing mice under the stress of irradiation

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Amal I. Hassan

2014-04-01

Full Text Available Radiation therapy aims to kill cancer cells with a minimum of normal tissue exposure. In an attempt to define the molecular and biochemical changes associated with exposure to radiotherapy, the objective of the present study is to explore the effect of gamma (γ irradiation on nuclear factor, erythroid 2 (NFE2, P53, stromelysin-1 (matrix metalloproteinase-3 (MMP3, BCL-2 and BAX genes expression in Ehrlich ascites carcinoma (EAC bearing mice. Various biochemical parameters such as liver function, H2O2, B% and T% lymphocytes, total antioxidants and MDA were investigated to evaluate their usefulness as possible during cancer treatment with radiotherapy. Rats were irradiated with a single whole body Cobalt 60-gamma radiation dose of 0.5 Gy. Sixty-four female mice, weighing 20–25 g were used in this study and divided into three main groups. The first group served as control group, while the second were injected intraperitoneally with EAC then was subdivided into two groups, II A and II B. The latter one (group II B, the animals were exposed to a single dose of 0.5 Gy whole body γ irradiation. The third main group, were irradiated with a single dose of 0.5 Gy whole body γ irradiation. Blood and liver tissue samples were collected at 4, 24 and 96 h post-irradiation. The gene expression levels in the livers of animals from each exposure group were compared individually with that of pooled sham-irradiated animals. MMP3 and NFE2 were overexpressed in liver samples of EAC group post 4, 24 and 96 h of γ irradiation (IIB. On the other hand, P53 and BCL-2 genes were downregulated by using RT-PCR analysis post 4, 24 and 96 h of γ irradiation (IIB. As well as, liver function and MDA were increased significantly in the γ - irradiation group (3rd group when compared to control mice (1st group. Gamma irradiation 3rd group revealed increase in the level of T% and B% lymphocytes. According to the obtained results, both γ rays and time period alter

Effect of misonidazole on radiosensitivity of Ehrlich ascites tumor cells

International Nuclear Information System (INIS)

Takeuchi, Hiroshi

1986-01-01

The effect of Misonidazole on radiosensitivity of Ehrlich ascites tumor cells was studied in vivo. Ehrlich ascites tumor cells growing intraperitoneally (ICR/SIC mice) for either 1, 4, 6 or 10 days were irradiated in vivo (whole body irradiation) with or without Misonidazole. Immediately after irradiation tumor cells were transplanted intraperitoneally into new animals. Four days later, the propagated surviving cells were removed and counted for analyses. Enhancement ratio of Misonidazole at the surviving fraction of 0.1 were 1.0 (for 1-day-old), 1.3 (for 4-day-old), 1.9 (for 6-day-old), 1.9 (for 10-day-old) and 2.8 (for anoxic cells) respectively. The gradual increase of the enhancement ratio of the ascites tumore cells during intraperitoneal growth from 1 through 10 days might be attributed to an increase of hypoxic tumor cells. Cytotoxicity was not observed at 0.1 mg per gram body weight of Misonidazole but was at 1 mg per gram body weight of Misonidazole in 6-day-old and 10-day-old Ehrlich ascites tumor cells which were supposed to contain hypoxic cells. These results suggest that Misonidazole may prove an effective radiosensitizer for hypoxic tumor cells. (author)

Study of the cellular uptake and distribution of 57cobalt bleomycin in Ehrlich ascites tumor cells

International Nuclear Information System (INIS)

Metelmann, H.R.

1980-01-01

We investigated the dependence of the cellular uptake of 57 cobalt-bleomycin on the exposure time and on the dose. In addition we observed the influences due to the incubation temperature, to the growth phase of the tumor cells and due to the composition of the suspensory medium. In supplementary experiments we investigated the binding of the labelled cytostatic agent to erythrocytes, its adsorption to broken Ehrlich ascites tumor cells and the 57 cobalt-bleomycin outflow from pre-loaded intact Ehrlich ascites tumor cells. The 57 cobalt-bleomycin uptake of intact Ehrlich ascites tumor cells is determined by characteristic kinetics. Moreover, the erythrocytes and injured Ehrlich ascites tumor cells show a qualitatively similar graph of the 57 cobalt-bleomycin binding, which can clearly be distinguished from the kinetics found with intact Ehrlich ascites tumor cells. The uptake of this cytostatic agent depends on an unequivocal time-dose-temperature relationship. The transport mechanism of the 57 cobalt-bleomycin uptake was considered as endocytosis. An endocytosis-stimulating inducer could not be detected. However, we obtained indications that the cell-bound cytostatic agent is taken up in two compartments: on the cellular surface and in the interior of the cell. (orig./MG) [de

Ehrlich ascites carcinoma | Ozaslan | African Journal of Biotechnology

African Journals Online (AJOL)

Experimental tumors have great importance in modeling, and Ehrlich ascites carcinoma (EAC) is one of the commonest tumors. EAC is referred to as an undifferentiated carcinoma and is originally hyperdiploid, has high transplantable capability, no-regression, rapid proliferation, shorter life span, 100% malignancy and also ...

Immune mechanisms in Ehrlich ascites tumor growth in mice

International Nuclear Information System (INIS)

Marusic, M.

1979-01-01

Normal mice immunised with irradiated Ehrlich ascites tumor (EAT) cells rejected EAT challenge given 2 weeks later but T-cell-deficient thymectomised lethally irradiated, and bone-marrow-reconstituted (TIR) mice succumbed. However, when TIR mice were injected i.v. with thymus, lymph node, or spleen cells from normalsyngetic donors immediately following i.p. injection of irradiated EAT cells, they rejected the subsequent tumor challenge. This induction of immunity in TIR mice was shown to be T-cell dependent. Spleen cells from EAT- bearing mice given immediately after irradiated tumor cells were also able to promote rejection of EAT challenge in TIR mice. Spleen cells from EAT-immune mice inhibited EAT growth when admixed with tumor cells prior to i.p. injection into normal recipients, but had no effect on progressive tumor growth when given i.v. immediately after i.p. tumor injection. Immune serum inhibited i.p. EAT growth when given either i.p. or i.v. Whereas inhibition of EAT growth by admixed spleen cells was shown to be T-cell independent. The data indicate that T lymphocytes are required only in the induction phase of the immune reponse of mice against EAT, while the efferent phase of the response is accomplished by serum antibodies, perhaps through an interaction with host macrophages. (author)

Surface Modification Of The High Temperature Porous Sliding Bearings With Solid Lubricant Nanoparticles

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Wiśniewska-Weinert H.

2015-09-01

Full Text Available A surface modification of stainless steel bearing sleeves is developed to improve the tribology characteristics at high temperature. Solid lubricant nano- and microparticles are applied for this purpose. To create the quasi-hydrodynamic lubrication regimes, the solid lubricant powder layer is made by developed pressure impregnation technique. Porous sliding bearing sleeve prototypes were made by powder metallurgy technique. The purpose of the paper is to define the friction and wear characteristics of the sleeves and to determine the influence of sealing of the sliding interface on these characteristics. It is found that application of WS2 sold lubricant nano- and micro-particles and preservation of a particle leakage out of interface allows to achieve at the high temperature the friction coefficients comparable to those at ambient temperature.

On the experience of the management of solid alpha-bearing wastes

International Nuclear Information System (INIS)

Kryuchkov, V.A.; Rakov, N.A.; Romanovskii, V.N.; Yakushev, M.F.

1978-01-01

Spent fuel reprocessing is studied in a pilot plant. Low and high level radioactive wastes handling is described. Liquid wastes are solidified. Combustible solid wastes are incinerated. Non-combustible and ashes are send to disposal site. Volume reduction of alpha-bearing wastes is obtained by optimisation of the reprocessing and development of remote control methods

Antitumor Properties of Modified Detonation Nanodiamonds and Sorbed Doxorubicin on the Model of Ehrlich Ascites Carcinoma.

Science.gov (United States)

Medvedeva, N N; Zhukov, E L; Inzhevatkin, E V; Bezzabotnov, V E

2016-01-01

We studied antitumor properties of modified detonation nanodiamonds loaded with doxorubicin on in vivo model of Ehrlich ascites carcinoma. The type of tumor development and morphological characteristics of the liver, kidneys, and spleen were evaluated in experimental animals. Modified nanodiamonds injected intraperitoneally produced no antitumor effect on Ehrlich carcinoma. However, doxorubicin did not lose antitumor activity after sorption on modified nanodiamonds.

Numerical Simulation and Experimental Study on the Gas-Solid Coupling of the Aerostatic Thrust Bearing with Elastic Equalizing Pressure Groove

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Zhao Xiao-long

2017-01-01

Full Text Available Aiming at the problem of low stiffness of aerostatic bearing, according to the principle of gas-solid coupling, this paper designs a kind of aerostatic thrust bearing with elastic equalizing pressure groove (EEPG and investigates the effect of elastic equalizing pressure groove (EEPG on the stiffness of aerostatic bearing. According to the physical model of the bearing, one deduces the deformation control equation of the elastic equalizing pressure groove and the control equation of gas lubrication, using finite difference method to derive the control equations and coupling calculation. The bearing capacity and stiffness of aerostatic bearing with EEPG in different gas film clearance are obtained. The calculation results show that the stiffness increased by 59%. The results of numerical calculation and experimental results have good consistency, proving the gas-solid coupling method can improve the bearing stiffness.

Cell kinetics of Ehrlich ascites carcinoma transplanted in mice with different degrees of tumor resistance

International Nuclear Information System (INIS)

Brandt, K.L.B.

1974-01-01

Cell proliferation kinetics of Ehrlich ascites carcinoma grown in two strains of mice with different degrees of resistance to this tumor were examined. In the first portion of the study, growth of Ehrlich ascites carcinoma in nonresistant Swiss (Iowa) and slightly resistant CF1 mice was examined by measuring animal weight gain and host survival time after intraperitoneal injection of tumor cells. Since it appeared that CF1 mice were inherently more resistant than Swiss mice to the Ehrlich carcinoma, the second part of this investigation involved attempts to immunize CF1 mice against the tumor. Subcutaneous injections of Ehrlich cells previously exposed in vitro to 5000 R of 250 kVp x rays were utilized. One immunizing inoculation of lethally irradiated tumor cells afforded protection against an intraperitoneal challenge of 40 thousand Ehrlich cells. By varying the number and timing of immunizing inoculations it was possible to induce different degrees of tumor resistance in these mice. The most effective immunizing procedure utilized multiple inoculations of lethally irradiated tumor cells (LITC), followed by challenges with viable tumor cells (less than 1 million) which were rejected. These mice could then resist challenge inocula of 4 million viable tumor cells. In a few animals the immunizing procedures were ineffective; these animals, when challenged, developed even larger tumors than control mice. Tumor cell proliferation kinetics in these animals as well as in mice that were rejecting the tumor were examined in the third phase of the project. A shortening of the cell cycle was observed in almost all LITC-treated mice, whether tumor growth was eventually inhibited or stimulated. Decreased duration of the DNA-synthesis phase (S) of the tumor cell cycle was also a consistent finding. The role of the immune response in stimulating mitosis as well as in killing foreign cells was discussed. (U.S.)

Altered thymidylate synthetase in 5-fluorodeoxyuridine-resistant Ehrlich ascites carcinoma cells.

Science.gov (United States)

Jastreboff, M M; Kedzierska, B; Rode, W

1983-07-15

Thymidylate synthetase from 5-fluorodeoxyuridine-resistant Ehrlich ascites carcinoma cells was purified to a state close to electrophoretical homogeneity (sp. act. = 1.3 mumoles/min/mg protein) and studied in parallel with the homogeneous preparation of the enzyme from the parental Ehrlich ascites carcinoma cells. The enzyme from the resistant cells compared to that from the parental cells showed: (i) a higher turnover number (at least 91 against 31 min-1), (ii) a higher inhibition constant (19 against 1.9 nM) for FdUMP (a tight-binding inhibitor of both enzymes), (iii) a lower activation energy at temps above 36 degrees (1.37 against 2.59 kcal/mole), and (iv) a lower inhibition constant (26 against 108 microM) for dTMP, inhibiting both enzymes competitively vs dUMP.

Studies on the interaction between the Ehrlich ascites tumor cell and its fluid environment

International Nuclear Information System (INIS)

Magnani, B.

1984-01-01

In this dissertation, the glycolytic nature of the Ehrlich ascites tumor (EAT) cell is disclosed both in vivo and in vitro by experiments challenging it with glucose. It is demonstrated that EAT cells can cause the extracellular pH to drop to values sufficiently acidic so as to inhibit EAT glycolysis. However, the extracellular fluid or the Ascites Supernatant Fluid (ASF) reduced the extent to which the pH dropped during EAT cell glycolysis. A comparison of the activities of the sera from tumor-bearing mice and normal mice revealed that the serumfrom the tumor-bearing mice reduced the pH fall generated by the EAT cell in the same way as did ASF; normal mouse serum had no such effect. The metabolic pathways utilized during glucose catabolism were examined by radio-respirometry and the results demonstrated that the high percentage of the glucose conversion to lactate occurred because of partial blockade of the TCA cycle. The databolism of glutamine, glutamic acid, asparagine, aspartic acid, and alanine was enhanced by ASF as determined by measuring 14 CO 2 from 14 C-labelled amino acids, with glutamine catabolism enhanced about three-fold. Fractionation experiments revealed that ASF contained a factor(s) responsible for this enhancement that had a molecular weight greater than 300,000 daltons and was heat-labile

Differential response of human melanoma and Ehrlich ascites cells in vitro to the ribosome-inactivating protein luffin.

Science.gov (United States)

Poma, A; Miranda, M; Spanò, L

1998-10-01

The cytotoxicity and inhibitory effect on proliferation of the type 1 ribosome-inactivating protein luffin purified from the seeds of Luffa aegyptiaca were investigated both in human metastatic melanoma cells and in murine Ehrlich ascites tumour cells. Results indicate that luffin from the seeds of Luffa aegyptiaca is cytotoxic to the cell lines tested, with approximately 10 times greater potency in Ehrlich cells. Luffin was found to induce an increase in cytosolic oligonucleosome-bound DNA in both melanoma and Ehrlich ascites tumour cells, the level of DNA fragmentation in the former cell line being higher than in the latter. Experiments with melanoma cells indicate that an increase in cytosolic nucleosomes could be supportive of apoptosis as the type of cell death induced by luffin.

CYTOTOXICITY OF ARTEMISININ-RELATED ENDOPEROXIDES TO EHRLICH ASCITES TUMOR-CELLS

NARCIS (Netherlands)

WOERDENBAG, HJ; MOSKAL, TA; PRAS, N; MALINGRE, TM; ELFERALY, FS; KAMPINGA, HH; KONINGS, AWT

A series of artemisinin-related endoperoxides was tested for cytotoxicity to Ehrlich ascites tumor (EAT) cells using the microculture tetrazolium (MTT) assay. Artemisinin [1] had an IC50 value of 29.8 muM. Derivatives of dihydroartemisinin [2], being developed as antimalarial drugs (artemether [3],

Ultrastructural identification of Ehrlich ia sp in an experimentally infected dog in Venezuela

International Nuclear Information System (INIS)

Gutierrez, N.; Martinez, M.; Arraga Alvarado, C.; Bretana, A.; Pacheco, I.; Comach, G.

1999-01-01

This study is the first report made in Venezuela concerning the ultrastructural characteristics of Ehrlich ia sp in mononuclear blood cells from an experimentally infected dog. The animal developed clinical manifestations characteristic of the infection, and typical intracytoplasmic inclusion bodies were clearly seen in blood smears stained with modified Giemsa examined by light microscopy. Microorganisms were visualized by transmission electron microscopy. The cytoplasmic inclusions, consisted of membrane-lined vacuole-containing elementary bodies. The organisms were extremely pleomorphic. Elementary bodies were surrounded by two distinct membranes and each was constituted by electro-dense granules. These findings corresponded to the described electron microscopy morphology which characterizes the Ehrlich ia genus

[Ilya Ilich Metchnikov and Paul Ehrlich: 1908 Nobel Prize winners for their research on immunity].

Science.gov (United States)

Lokaj, J; John, C

2008-11-01

The Nobel Prize in Physiology or Medicine in 1908 was awarded to Ilya I. Mechnikov and Paul Ehrlich for recognition of their work on immunity. Mechnikov have discovered phagocytes and phagocytosis as the basis of natural cellular immunity. His ,,phagocytic theory" is the principle of immunological concept "self and not self" as the prerequisition of physiological inflammation, and selfmaintaining of organism. Ehrlich developed the methods for standardization of antibody activity in immune sera, described neutralizing and complement-depending effect of antibodies and enunciated the ,"ide-chain" theory of the formation of antibodies. Their concept of the key-stone of immunity was different, but they expressed the basic paradigma of immunology: immunity imply the protection of identity and guarantee the integrity of organism. Both are the founders of immunology as the scientific discipline. Discoveries and conceptions of I. Mechnikov and P. Ehrlich exceedingly influenced development of immunology and are also applicable, instructive and suggestive in contemporary immunology and microbiology.

Cell Swelling Activates Phospholipase A2 in Ehrlich Ascites Tumor Cells

DEFF Research Database (Denmark)

Thoroed, S.M.; Lauritzen, L.; Lambert, I.H.

1997-01-01

Ehrlich ascites tumor cells! loaded with H-labeled arachidonic acid and C-labeled stearic acid for two hours, were washed and transferred to either isotonic or hypotonic media containing BSA to scavenge the labeled fatty acids released from the cells. During the first two minutes of hypo......-osmotic exposure the rate of H-labeled arachidonic acid release is 3.3 times higher than that observed at normal osmolality. Cell swelling also causes an increase in the production of C-stearic acid-labeled lysophosphatidylcholine. This indicates that a phospholipase A is activated by cell swelling in the Ehrlich...... cells. Within the same time frame there is no swelling-induced increase in C-labeled stearic acid release nor in the synthesis of phosphatidyl C-butanol in the presence of C-butanol. Furthermore, U7312, an inhibitor of phospholipase C, does not affect the swelling induced release of C...

Combination effect of cisplatin and radiation in murine solid tumors

International Nuclear Information System (INIS)

Egawa, Shin; Lee, Kan-ei; Ishibashi, Akira; Komiyama, Hiroki; Umezawa, Iwao.

1986-01-01

The combination effect of cisplatin and radiation was studied using the two different murine systems of sarcoma 180 and Ehrlich solid tumors. In sarcoma 180 solid tumor the minimal effective doses (MED) of cisplatin and radiation were 19.5 mg/kg and 10375 rad respectively whereas these doses did not show any effective antitumor activity practically. Administration of cisplatin with a doses of 9 mg/kg given 24 hours before radiation (1000 rad), however, showed synergistic antitumor activity. In Ehrlich solid tumor the MED of cisplatin and radiation were 13.8 mg/kg and 2892 rad respectively. Treatment with cisplatin, 3, 6 or 9 mg/kg, given 24 hours before radiation (1000 rad) showed also synergistic antitumor activity also. Sodium thiosulfate (STS) rescue was effective in reducing toxicity of cisplatin on combined use of the drug with radiation. Cell kinetics of sarcoma 180 solid tumor in vivo after the combined treatment was analyzed by computer aided flowcytometry. Accumulation of cells in the radiosensitive G 2 + M phase was observed 18 to 42 hours after a single intraperitoneal administration of 9 mg/kg of cisplatin. It is strongly suggested that this synchronization is one of the mechanisms of the synergism in the combination therapy. (author)

Biological Effect of Ganoderma lucidum in Mice Suffering from Ehrlich Carcinoma and Gamma Radiation

International Nuclear Information System (INIS)

Fahim, Th.M.; Sherif, N.H.; Abd El-Azime, A.Sh.

2013-01-01

The popular edible mushroom Ganoderma lucidum (G. lucidum) has been widely used for the general promotion of health and longevity in oriental countries. The present study was performed to investigate the antitumor effect of G. lucidum on Ehrlich carcinoma (EC) cells and/or gamma radiation-induced oxidative stress, kidney dysfunction and histopathological changes in the albino mouse. G. lucidum was orally administered via gavages to mice for a period of 3 weeks at a dose of 100 mg/kg body weight begins on the 10th day of tumor inoculation. Animals were exposed to 4 Gy whole body γ radiation after 2 weeks of tumor inoculation. The antitumor effect of G. lucidum was evident in terms of a reduction in tumor viable cells count, inhibited both weight loss and tumor growth rate of EC-tumor bearing mice alone and in combination with gamma-radiation. Inoculation of mice with EC cells resulted in biochemical and histopathological changes leading to kidney damage. Oral administration of G. lucidum improved kidney functions through a recovery of the elevated levels of serum urea, creatinine, uric acid and increased albumin level and decreased the levels of tumor markers. Also, treatment of mice with G. lucidum induced a reduction of lipid peroxidation (MDA) level, improvement in glutathione content (GSH) and superoxide dismutase (SOD) activity in the kidney compared with those EC and /or irradiated damaged mice. On the other hand, treatment EC bearing mice with gamma radiation or G. lucidum combined showed increase in MDA level and decrease in GSH content and SOD activity, as compared to EC bearing mice. Histopathological studies showed that suffering from EC caused fatty degeneration, presence of necrosis and enlargement of kidney cells nuclei. Furthermore, an elevation of tail DNA % was recorded in the tumor tissue of mice treated with G. lucidum and/or γ radiation compared to EC control group. Treatment of EC bearing mice with G. lucidum and/or γ radiation exhibited

Regulating ehrlich and demethiolation pathways for alcohols production by the expression of ubiquitin-protein ligase gene HUWE1.

Science.gov (United States)

Zhang, Quan; Jia, Kai-Zhi; Xia, Shi-Tao; Xu, Yang-Hua; Liu, Rui-Sang; Li, Hong-Mei; Tang, Ya-Jie

2016-02-10

Ehrlich and demethiolation pathways as two competing branches converted amino acid into alcohols. Controlling both pathways offers considerable potential for industrial applications including alcohols overproduction, flavor-quality control and developing new flavors. While how to regulate ehrlich and demethiolation pathways is still not applicable. Taking the conversion of methionine into methionol and methanethiol for example, we constructed two suppression subtractive cDNA libraries of Clonostachys rosea by using suppression subtractive hybridization (SSH) technology for screening regulators controlling the conversion. E3 ubiquitin-protein ligase gene HUWE1 screened from forward SSH library was validated to be related with the biosynthesis of end products. Overexpressing HUWE1 in C. rosea and S. cerevisiae significantly increased the biosynthesis of methanethiol and its derivatives in demethiolation pathway, while suppressed the biosynthesis of methional and methionol in ehrlich pathway. These results attained the directional regulation of both pathways by overexpressing HUWE1. Thus, HUWE1 has potential to be a key target for controlling and enhancing alcohols production by metabolic engineering.

pH regulation in sensitive and multidrug resistant Ehrlich ascites tumor cells

DEFF Research Database (Denmark)

Litman, Thomas; Pedersen, S F; Kramhøft, B

1998-01-01

Maintenance and regulation of intracellular pH (pHi) was studied in wild-type Ehrlich ascites tumor cells (EHR2) and five progressively daunorubicin-resistant, P-glycoprotein (P-gp)-expressing strains, the maximally resistant of which is EHR2/1.3. Steady-state pHi was similar in cells expressing...

Anticancer Potential of Aqueous Ethanol Seed Extract of Ziziphus mauritiana against Cancer Cell Lines and Ehrlich Ascites Carcinoma

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Tulika Mishra

2011-01-01

Full Text Available Ziziphus mauritiana (Lamk. is a fruit tree that has folkloric implications against many ailments and diseases. In the present study, anticancer potential of seed extract of Ziziphus mauritiana in vitro against different cell lines (HL-60, Molt-4, HeLa, and normal cell line HGF by MTT assay as well as in vivo against Ehrich ascites carcinoma bearing Swiss albino mice was investigated. The extract was found to markedly inhibit the proliferation of HL-60 cells. Annexin and PI binding of treated HL-60 cells indicated apoptosis induction by extract in a dose-dependent manner. The cell cycle analysis revealed a prominent increase in sub Go population at concentration of 20 μg/ml and above. Agarose gel electrophoresis confirmed DNA fragmentation in HL-60 cells after 3 h incubation with extract. The extract also exhibited potent anticancer potential in vivo. Treatment of Ehrlich ascites carcinoma bearing Swiss albino mice with varied doses (100–800 mg/kg b.wt. of plant extract significantly reduced tumor volume and viable tumor cell count and improved haemoglobin content, RBC count, mean survival time, tumor inhibition, and percentage life span. The enhanced antioxidant status in extract-treated animals was evident from decline in levels of lipid peroxidation and increased levels of glutathione, catalase, and superoxide dismutase.

A comparative study of 99mTc-HL91 and 99mTc-MIBI imaging in experimental tumor and inflammatory models

International Nuclear Information System (INIS)

Cao, W.; Zhang, X.Y.; An, R.

2002-01-01

Aim: 99m Tc-HL91 is a newly developed hypoxic imaging agent for ischemic myocardium and tumor imaging. 99m Tc-MIBI is one of imaging agent for mammary tumor imaging. The aim of this experiment is to evaluate the diagnostic value of 99m Tc-HL91 in detection of solid tumor in experimental tumor and inflammatory models, via comparative study with 99m Tc-MIBI. Material and Methods: HL91 kits was provided by China Nine Star Co. Three kinds of bearing solid neoplasm mice groups (bearing Ehrlich carcinoma mice, bearing H 22 carcinoma mice and bearing human ovarian COC 1 neoplasm nude mice) and two inflammatory model groups (chemical and bacterial inflammation) underwent static whole body planar images at 1 and 4 hours post injection of 99m Tc-HL91. Two kinds of bearing neoplasm mice groups (bearing Ehrlich carcinoma mice, bearing H 22 carcinoma mice) and two inflammatory model groups (chemical and bacterial inflammation) underwent static planar images post injection of 99m Tc-MIBI, at early phase (10∼20 minutes) and delayed phase (2 hrs). All of mice were sacrificed at 4 hrs. The tumors, or inflammatory lesions, blood and contralateral muscles were removed, weighed and the radioactivity was measured. Regions of interesting (ROIs) were drawn around tumor, inflammatory lesions and contralateral muscles in planar images, and the radioactivity ratios of target (tumor or inflammatory lesions)-to-blood (T/B), target-to-non target (contralateral muscles) i. e. T/NT was calculated. Results: Neoplasm can be clearly visible in planar images at 1hr and 4 hrs post injection of 99m Tc-HL91 in all tumor models. At same time inflammatory lesions cannot be seen clearly. Neoplasm can be seen in delayed phase in 99m Tc-MIBI groups, but not easy to distinguish them from inflammation. Conclusion: Compared with 99m Tc-MIBI imaging, 99m Tc-HL91 has much more diagnostic value in detection of solid neoplasm, and can distinguish neoplasm from inflammation

Activation and inactivation of the volume-sensitive taurine leak pathway in NIH3T3 fibroblasts and Ehrlich Lettre ascites cells

DEFF Research Database (Denmark)

Lambert, Ian Henry

2007-01-01

Hypotonic exposure provokes the mobilization of arachidonic acid, production of ROS, and a transient increase in taurine release in Ehrlich Lettre cells. The taurine release is potentiated by H(2)O(2) and the tyrosine phosphatase inhibitor vanadate and reduced by the phospholipase A(2) (PLA(2......)) inhibitors bromoenol lactone (BEL) and manoalide, the 5-lipoxygenase (5-LO) inhibitor ETH-615139, the NADPH oxidase inhibitor diphenyl iodonium (DPI), and antioxidants. Thus, swelling-induced taurine efflux in Ehrlich Lettre cells involves Ca(2+)-independent (iPLA(2))/secretory PLA(2) (sPLA(2)) plus 5-LO...... activity and modulation by ROS. Vanadate and H(2)O(2) stimulate arachidonic acid mobilization and vanadate potentiates ROS production in Ehrlich Lettre cells and NIH3T3 fibroblasts under hypotonic conditions. However, vanadate-induced potentiation of the volume-sensitive taurine efflux is, in both cell...

Relationship between strains of tumor-bearing animals and the tumor affinity of /sup 169/Yb and /sup 67/Ga

Energy Technology Data Exchange (ETDEWEB)

Ando, A; Hiraki, T [Kanazawa Univ. (Japan). School of Paramedicine; Hisada, K; Ando, I; Ugiie, T

1975-02-01

It is well a well-known fact that ytterbium-169 is a strong bone seeking element. We have already reported that this element was concentrated in nonosseous tumor tissues and that its tumor affinity was stronger than that of gallium-67 in our previous experiment using Yoshida sarcoma-bearing rats. Ytterbium-169 citrate and gallium-67 citrate were compared in four strains of tumor-bearing rats and mice. The uptake rate of ytterbium-169 in tumor tissues was much larger than that of gallium-67 in Ehrlich cancer-bearing mice, but these values of ytterbium-169 were slightly smaller than those of gallium-67 in Yoshida sarcoma-bearing rats, Walker carcinosarcoma 256-bearing rats and sarcoma 180-bearing mice. Tumor to organ ratios of ytterbium-169, which were most important for tumor scanning agents, were much larger than those of gallium-67 in all four strains except for the tumor to bone ratio of ytterbium-169. From the above-described facts, it was shown that ytterbium-169 citrate had a stronger tumor affinity than did gallium-67 citrate and that the tumor affinity of ytterbium-169 citrate was similar in each of these four strains of tumor-bearing animals.

Effect of anhydrosophoradiol-3-acetate of Calotropis gigantea (Linn.) flower as antitumoric agent against Ehrlich's ascites carcinoma in mice.

Science.gov (United States)

Habib, Muhammad R; Karim, Muhammad R

2013-01-01

Over 60% of currently used anti-cancer agents are derived in one-way or another from natural sources, including plants, marine organisms and microorganisms. Calotropis gigantea (Linn.) (Family: Asclepiadaceae) is a perennial shrub and it is used as a traditional folk medicine for the treatment of various health complications. But there is no report on isolation of anticancerous chemicals from the flower of Calotropis gigantea. The objective of the present study is to explore the antitumor effect of anhydrosophoradiol-3-acetate (A3A), isolated from the flower of Calotropis gigantea (Linn.) against Ehrlich's ascites carcinoma (EAC) in Swiss albino mice. Antitumoric effect of A3A was assessed by evaluating viable tumor cell count, survival time, body weight gain due to tumor burden, hematological and biochemical (glucose, cholesterol, triglyceride, blood urea, SALP, SGPT and SGOT) parameters of EAC bearing host at doses of 10 and 20 mg/kg body weight. Treatment with A3A decreased the viable tumor cells and body weight gain thereby increasing the life span of EAC bearing mice. A3A also brought back the altered hematological (Hb, total RBC and total WBC) and biochemical parameters more or less to normal level. Results of this study conclude that in vivo the A3A was effective in inhibiting the growth of EAC with improving in cancer induced complications.

Sensing sulfur oxides and other sulfur bearing pollutants with solid electrolyte pellets. I. Gas concentration cells

Energy Technology Data Exchange (ETDEWEB)

Chamberland, A M; Gauthier, J M

1977-01-01

A new sensing technique using a solid electrolyte has been demonstrated for sulfur-bearing pollutants. Based on potentiometric measurements across a pellet of potassium sulfate, this sensor allows concentrations of sulfur dioxides, sulfur trioxide, hydrogen sulfide, methyl mercaptan and carbonyl sulfide in air to be measured with accuracy. Its operational concentration range at the present time is 0.1 ppM up to at least 10,000 ppM. The presence of other common pollutants such as carbon dioxide, methane, nitric oxide and nitrogen dioxide does not interfere with the measurement of air samples containing sulfur-bearing pollutants.

Cell swelling activates separate taurine and chloride channels in Ehrlich mouse ascites tumor cells

DEFF Research Database (Denmark)

Lambert, Ian Henry; Hoffmann, Else Kay

1994-01-01

The taurine efflux from Ehrlich ascites tumor cells is stimulated by hypotonic cell swelling. The swelling-activated taurine efflux is unaffected by substitution of gluconate for extracellular Cl– but inhibited by addition of MK196 (anion channel blocker) and 4,4 -diisothiocyanostilbene-2......,2 -disulfonic acid (DIDS; anion channel and anion exchange blocker) and by depolarization of the cell membrane. This is taken to indicate that taurine does not leave the osmotically swollen Ehrlich cells in exchange for extracellular Cl–, i.e., via the anion exchanger but via a MK196- and DIDS-sensitive channel...... that is potential dependent. An additional stimulation of the swelling-activated taurine efflux is seen after addition of arachidonic acid and oleic acid. Cell swelling also activates a Mini Cl– channel. The Cl– efflux via this Cl– channel, in contrast to the swelling-activated taurine efflux, is unaffected by DIDS...

Exposure of tumor-bearing mice to extremely high-frequency electromagnetic radiation modifies the composition of fatty acids in thymocytes and tumor tissue.

Science.gov (United States)

Gapeyev, Andrew B; Kulagina, Tatiana P; Aripovsky, Alexander V

2013-08-01

To test the participation of fatty acids (FA) in antitumor effects of extremely high-frequency electromagnetic radiation (EHF EMR), the changes in the FA composition in the thymus, liver, blood plasma, muscle tissue, and tumor tissue in mice with Ehrlich solid carcinoma exposed to EHF EMR were studied. Normal and tumor-bearing mice were exposed to EHF EMR with effective parameters (42.2 GHz, 0.1 mW/cm2, 20 min daily during five consecutive days beginning the first day after the inoculation of tumor cells). Fatty acid composition of various organs and tissues of mice were determined using a gas chromatography. It was shown that the exposure of normal mice to EHF EMR or tumor growth significantly increased the content of monounsaturated FA (MUFA) and decreased the content of polyunsaturated FA (PUFA) in all tissues examined. Exposure of tumor-bearing mice to EHF EMR led to the recovery of FA composition in thymocytes to the state that is typical for normal animals. In other tissues of tumor-bearing mice, the exposure to EHF EMR did not induce considerable changes that would be significantly distinguished between disturbances caused by EHF EMR exposure or tumor growth separately. In tumor tissue which is characterized by elevated level of MUFA, the exposure to EHF EMR significantly decreased the summary content of MUFA and increased the summary content of PUFA. The recovery of the FA composition in thymocytes and the modification of the FA composition in the tumor under the influence of EHF EMR on tumor-bearing animals may have crucial importance for elucidating the mechanisms of antitumor effects of the electromagnetic radiation.

Evaluation of antitumour activity of Calotropis gigantea L. root bark against Ehrlich ascites carcinoma in Swiss albino mice.

Science.gov (United States)

Habib, M Rowshahul; Karim, M Rezaul

2011-10-01

To investigate experimentally the possible antitumor effect of methanol extract (ME) of Calotropis gigantea L. (C. gigantean) root bark and its petroleum ether (PEF) and chloroform (CF) soluble fractions against Ehrlich ascites carcinoma (EAC) in Swiss albino mice. The effects of ME (10 and 20 mg/kg), PEF (40 and 80 mg/kg) and CF (20 and 40 mg/kg) on the growth of EAC and life span of EAC bearing mice were studied. Hematological profile and biochemical parameters (SALP, SGPT and SGOT) were also estimated. Results of in vivo study showed a significant decrease in viable tumor cell count and a significant increase of life span in the ME and CF treated group compared to untreated one. The life span of ME and CF treated animals was significantly (PSALP) and serum glutamate oxaloacetate transaminase (SGOT). Methanol extract (ME) of C. gigantea root bark and its chloroform soluble fraction (CF) possesses significant antitumor activity. Copyright © 2011 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

Monovalent ions control proliferation of Ehrlich Lettre ascites cells

DEFF Research Database (Denmark)

Klausen, Thomas Kjaer; Preisler, Sarah; Pedersen, Stine Helene Falsig

2010-01-01

of Ehrlich Lettre ascites (ELA) cells. We measured the intracellular concentration of each ion in G(0), G(1), and S phases of the cell cycle following synchronization by serum starvation and release. We show that intracellular concentrations and content of Na+ and Cl(-) were reduced in the G(0)-G(1) phase...... effect. Western blots showed reduced chloride intracellular channel CLIC1 and chloride channel ClC-2 expression in the plasma membrane in S compared with G(1). Our results suggest that Na+ regulates ELA cell proliferation by regulating intracellular pH while Cl(-) may regulate proliferation by fine...

L-lactate transport in Ehrlich ascites-tumour cells.

Science.gov (United States)

Spencer, T L; Lehninger, A L

1976-01-01

Ehrlich ascites-tumour cells were investigated with regard to their stability to transport L-lactate by measuring either the distribution of [14C]lactate or concomitant H+ ion movements. The movement of lactate was dependent on the pH difference across the cell membrane and was electroneutral, as evidenced by an observed 1:1 antiport for OH- ions or 1:1 symport with H+ ions. 2. Kinetic experiments showed that lactate transport was saturable, with an apparent Km of approx. 4.68 mM and a Vmax. as high as 680 nmol/min per mg of protein at pH 6.2 and 37 degrees C. 3. Lactate transport exhibited a high temperature dependence (activation energy = 139 kJ/mol). 4. Lactate transport was inhibited competitively by (a) a variety of other substituted monocarboxylic acids (e.g. pyruvate, Ki = 6.3 mM), which were themselves transported, (b) the non-transportable analogues alpha-cyano-4-hydroxycinnamate (Ki = 0.5 mM), alpha-cyano-3-hydroxycinnamate (Ki = 2mM) and DL-p-hydroxyphenyl-lactate (Ki = 3.6 mM) and (c) the thiol-group reagent mersalyl (Ki = 125 muM). 5. Transport of simple monocarboxylic acids, including acetate and propionate, was insensitive to these inhibitors; they presumably cross the membrane by means of a different mechanism. 6. Experiments using saturating amounts of mersalyl as an "inhibitor stop" allowed measurements of the initial rates of net influx and of net efflux of [14C]lactate. Influx and efflux of lactate were judged to be symmetrical reactions in that they exhibited similar concentration dependence. 7. It is concluded that lactate transport in Ehrlich ascites-tumour cells is mediated by a carrier capable of transporting a number of other substituted monocarboxylic acids, but not unsubstituted short-chain aliphatic acids. PMID:7237

Effect of cyhalothrin on Ehrlich tumor growth and macrophage activity in mice

Directory of Open Access Journals (Sweden)

W.M. Quinteiro-Filho

2009-10-01

Full Text Available Cyhalothrin, a pyrethroid insecticide, induces stress-like symptoms, increases c-fos immunoreactivity in the paraventricular nucleus of the hypothalamus, and decreases innate immune responses in laboratory animals. Macrophages are key elements in cellular immune responses and operate at the tumor-host interface. This study investigated the relationship among cyhalothrin effects on Ehrlich tumor growth, serum corticosterone levels and peritoneal macrophage activity in mice. Three experiments were done with 10 experimental (single gavage administration of 3.0 mg/kg cyhalothrin daily for 7 days and 10 control (single gavage administration of 1.0 mL/kg vehicle of cyhalothrin preparation daily for 7 days isogenic BALB/c mice in each experiment. Cyhalothrin i increased Ehrlich ascitic tumor growth after ip administration of 5.0 x 106 tumor cells, i.e., ascitic fluid volume (control = 1.97 ± 0.39 mL and experimental = 2.71 ± 0.92 mL; P < 0.05, concentration of tumor cells/mL in the ascitic fluid (control = 111.95 ± 16.73 x 106 and experimental = 144.60 ± 33.18 x 106; P < 0.05, and total number of tumor cells in the ascitic fluid (control = 226.91 ± 43.22 x 106 and experimental = 349.40 ± 106.38 x 106; P < 0.05; ii increased serum corticosterone levels (control = 200.0 ± 48.3 ng/mL and experimental = 420.0 ± 75.5 ng/mL; P < 0.05, and iii decreased the intensity of macrophage phagocytosis (control = 132.3 ± 19.7 and experimental = 116.2 ± 4.6; P < 0.05 and oxidative burst (control = 173.7 ± 40.8 and experimental= 99.58 ± 41.7; P < 0.05 in vitro in the presence of Staphylococcus aureus. These data provide evidence that cyhalothrin simultaneously alters host resistance to Ehrlich tumor growth, hypothalamic-pituitary-adrenocortical (HPA axis function, and peritoneal macrophage activity. The results are discussed in terms of data suggesting a link between stress, HPA axis activation and resistance to tumor growth.

Development of new engine bearings with overlay consisting of solid lubricants; Kotai junkatsu overlay tsuki engine yo suberi jikuuke zairyo no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Kanayama, H; Kawakami, S; Gohara, C [Taiho Kogyo Co. Ltd., Aichi (Japan); Fuwa, Y; Michioka, H [Toyota Motor Corp., Aichi (Japan)

1997-10-01

Recently, modern engines have a tendency for higher output and longer periods. As a result , higher bearing performance is required. For this reason, we have developed the new conceptual overlay consisting of solid lubricants and thermosetting plastics. This paper describes the performance of engine bearings with the new overlay. 5 refs., 13 figs., 5 tabs.

Developments in the treatment of solid alpha-bearing wastes at the PNC plutonium fuel facilities

International Nuclear Information System (INIS)

Ohtsuka, K.; Miyo, H.; Ohuchi, J.; Shiga, K.; Muto, T.

1978-01-01

Some results of experiments done in PNC are presented on volume reduction technics for alpha-bearing wastes. A pilot wood milling machine automatically mills the plywood frames of nipple connected HEPA filters, which result in fine sized wooden chips, two nipples and the filter components. The filter components are melted in an induction furnace to be homogeneous solids. These methods and incineration of wooden chips reduce the stored volume of HEPA filters to 1/50 -- 1/100. PVC and neoprene rubber are decomposed in concentrated sulfuric acid, followed by oxidation with nitric acid. The acid digestion process generates chlorine-rich gas, from which only chlorine is selectively absorbed in water. An alpha-bearing vessel and a glovebox are cut at their installed places without spread of plutonium contamination outside the greenhouses. (auth.)

Activity monitoring of alpha-bearing wastes

International Nuclear Information System (INIS)

Birkhoff, G.; Bondar, L.

1980-01-01

The paper aims at the survey on the actual situation in activity monitoring of alpha-bearing wastes. Homogeneous materials such as liquid-, gaseous- and homogeneous solid wastes are amenable to destructive analyses of representative samples. Available destructive analyses methods are sensitive and precise enough to cope with all requirements in alpha-waste monitoring. The more difficult problems are encountered with alpha-contaminated solids, when representative sampling is not practicable. Non-destructive analysis techniques are applied for monitoring this category of solid wastes. The techniques for nondestructive analysis of alpha-bearing wastes are based on the detection of gamma and/or neutron-emission of actinides. Principles and a theory of non-destructive radiometric assay of plutonium contaminated solid waste streams are explained. Guidelines for the calibration of instruments and interpretation of experimental data are given. Current theoretical and experimental development work in this problem area is reviewed. Evaluations concerning capabilities and limitations of monitoring systems for alpha-bearing solid wastes are very complex and out of the scope of this paper

The evaluation of in vitro effect of daunorubicin and tamoxifen in ehrlich ascites tumour (EAT) cells

International Nuclear Information System (INIS)

Topcul, M.; Topcul, F.; Oezalpan, A.

2001-01-01

In the most countries, breast cancer is still the most important cancer among women. It is known that Ehrlich Ascites Tumour is experimental breast cancer model in animal. The cells used in the study are hyper diploid line of Ehrlich Ascites Tumour (EAT) cells, initially provided to us from Institute of Pathology, Koln University. In the present study, an hyper diploid line which is estrogen receptor positive was used. An anthracycline-derived antibiotic, Daunorubicin (DNR, Cerubidine) is one of the clinically used anticancer drugs. DNR has been used alone or in combination with other cytotoxic agents against a variety of animal and human tumours. In vitro cell culture studies show that DNR enters the cell nuclei, inhibits nucleic acid synthesis, and arrest cell division. Tamoxifen (TAM, Nolvadex) is a semi-synthetical estrogen antagonist, used in the management of pre and post menopausal breast cancer. This drug bind to intracellular estrogen receptors, and prevents endogenous estrogens from binding to their own receptors. It is known that Ehrlich Ascites Tumour is experimental breast cancer model in animal. The cells used in the study are hyper diploid line of EAT cells initially provided to us from Institute of Pathology, Koln University. In the present study, an hyper diploid line which is Estrogen Receptor (+) was used. Estrogen Receptor levels were studied by the methods of Lippman and Huff and Raynaud et al. with minor modifications. Estrogen Receptor activity as demonstrated by dextran-coated charcoal technique is closely correlated with the clinical ability of Tamoxifen to inhibit tumour growth

A novel copper complex induces ROS generation in doxorubicin resistant Ehrlich ascitis carcinoma cells and increases activity of antioxidant enzymes in vital organs in vivo

International Nuclear Information System (INIS)

Mookerjee, Ananda; Roy, Syamal; Choudhuri, Soumitra K; Basu, Jayati Mookerjee; Majumder, Surajit; Chatterjee, Shilpak; Panda, Gouri S; Dutta, Pranabananda; Pal, Smarajit; Mukherjee, Pratima; Efferth, Thomas

2006-01-01

In search of a suitable GSH-depleting agent, a novel copper complex viz., copper N-(2-hydroxyacetophenone) glycinate (CuNG) has been synthesized, which was initially found to be a potential resistance modifying agent and later found to be an immunomodulator in mice model in different doses. The objective of the present work was to decipher the effect of CuNG on reactive oxygen species (ROS) generation and antioxidant enzymes in normal and doxorubicin-resistant Ehrlich ascites carcinoma (EAC/Dox)-bearing Swiss albino mice. The effect of CuNG has been studied on ROS generation, multidrug resistance-associated protein1 (MRP1) expression and on activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx). CuNG increased ROS generation and reduced MRP1 expression in EAC/Dox cells while only temporarily depleted glutathione (GSH) within 2 h in heart, kidney, liver and lung of EAC/Dox bearing mice, which were restored within 24 h. The level of liver Cu was observed to be inversely proportional to the level of GSH. Moreover, CuNG modulated SOD, CAT and GPx in different organs and thereby reduced oxidative stress. Thus nontoxic dose of CuNG may be utilized to reduce MRP1 expression and thus sensitize EAC/Dox cells to standard chemotherapy. Moreover, CuNG modulated SOD, CAT and and GPx activities to reduce oxidative stress in some vital organs of EAC/Dox bearing mice. CuNG treatment also helped to recover liver and renal function in EAC/Dox bearing mice. Based on our studies, we conclude that CuNG may be a promising candidate to sensitize drug resistant cancers in the clinic

Effect of Au-dextran NPs as anti-tumor agent against EAC and solid tumor in mice by biochemical evaluations and histopathological investigations.

Science.gov (United States)

Medhat, Dalia; Hussein, Jihan; El-Naggar, Mehrez E; Attia, Mohamed F; Anwar, Mona; Latif, Yasmine Abdel; Booles, Hoda F; Morsy, Safaa; Farrag, Abdel Razik; Khalil, Wagdy K B; El-Khayat, Zakaria

2017-07-01

Dextran-capped gold nanoparticles (Au-dextran NPs) were prepared exploiting the natural polysaccharide polymer as both reducing and stabilizing agent in the synthesis process, aiming at studying their antitumor effect on solid carcinoma and EAC-bearing mice. To this end, Au-dextran NPs were designed via simple eco-friendly chemical reaction and they were characterized revealing the monodispersed particles with narrow distributed size of around 49nm with high negative charge. In vivo experiments were performed on mice. Biochemical analysis of liver and kidney functions and oxidation stress ratio in addition to histopathological investigations of such tumor tissues were done demonstrating the potentiality of Au-dextran NPs as antitumor agent. The obtained results revealed that EAC and solid tumors caused significant increase in liver and kidney functions, liver oxidant parameters, alpha feto protein levels and diminished liver antioxidant accompanied by positive expression of tumor protein p53 of liver while the treatment with Au-dextran NPs for both types caused improvement in liver and kidney functions, increased liver antioxidant, increased the expression level of B-cell lymphoma 2 gene and subsequently suppressed the apoptotic pathway. As a result, the obtained data provides significant antitumor effects of the Au-dextran NPs in both Ehrlich ascites and solid tumor in mice models. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

GROWTH FACTORS AND COX2 IN WOUND HEALING: AN EXPERIMENTAL STUDY WITH EHRLICH TUMORS.

Science.gov (United States)

Salgado, Flávio L L; Artigiani-Neto, Ricardo; Lopes-Filho, Gaspar de Jesus

2016-01-01

Healing is an innate biological phenomenon, and carcinogenesis acquired, but with common humoral and cellular elements. Carcinogenesis interferes negatively in healing. To evaluate the histological changes in laparotomy scars of healthy Balb/c mice and with an Ehrlich tumor in its various forms of presentation. Fifty-four mice were divided into three groups of 18 animals. First group was the control; the second had Ehrlich tumor with ascites; and the third had the subcutaneous form of this tumor. Seven days after tumor inoculation, all 54 mice were submitted to laparotomy. All of the animals in the experiment were operated on again on 7th day after surgery, with resection of the scar and subsequent euthanasia of the animal. The scars were sent for histological assessment using immunohistochemical techniques to evaluate Cox-2 (cyclooxygenase 2), VEGF (vascular endothelial growth factor) and FGF (fibroblast growth factor). Semi-quantitatively analysis was done in the laparotomy scars and in the abdominal walls far away from the site of the operation. Assessing the weight of the animals, the correct inoculation of the tumor and weight gain in the group with tumoral ascites was observed. The histological studies showed that groups with the tumor showed a statistically significant higher presence of Cox-2 compared to the control. In the Cox-2 analysis of the abdominal wall, the ascites group showed the most significant difference. VEGF did not present any significant differences between the three groups, regardless of the site. The FGF showed a significant increase in animals with the tumor. Histological findings in both laparotomy scar and the abdominal wall showed that with Ehrlich's neoplasia there was an exacerbated inflammatory response, translated by more intense expression of Cox-2 and greater fibroblast proliferation, translated by more intense expression of FGF, that is, it stimulated both the immediate inflammatory reactions, observed with Cox-2 reactions, and

Hydrostatic bearing with a stepped duct

International Nuclear Information System (INIS)

Krevsun, Eh.P.; Ivanov, A.A.

1975-01-01

A method for calculating and experimental data from tests on a hydrostatic bearing whose operating hydraulic channel is formed by two cylincrical surfaces, are presented. Unlike currently used hydrostatic bearings, the bearing described has no capillary choke or diaphragm choke at the entrance. This simplifies the construction and increases the reliability, especially when it is operated with corrosive liquids or liquids containing solid suspensoids and causing erosion and blockage of the choke structures. In order to obtain the calculated relations, the flow of a liquid from the bearing in the axial direction to one side through a part of an aperture of unit width was examined. The effect of rotating the axle, of flow in the circumferential direction, and curvature of the aperture was not considered. Isothermal and laminar flows were considered. Because of the simplicity of the hydraulic circuit and the satisfactory properties (bearing capability and flow rate), the bearing described may be used in pumps operating with corrosive liquids, with those containing solid suspensoids and in nuclear energy establishments. (author)

A poly (U) polymerase in ribosome preparations from Ehrlich ascites tumor cells

International Nuclear Information System (INIS)

Guimaraes, R.C.; Bloch, D.P.

1981-01-01

A ribosome-bound poly (U) polymerase from Ehrlich ascites tumor cells is partially characterized. It adds UMPs to RNAs terminating in U-(3')-OH. The UMP-rich segments added reach average sizes of up to 18 nucleotides. CTP is strongly inhibitory to the enzyme. The main endogenous primers are low molecular weight RNAs which are found, after the addition of UMPs, mostly in the 6-8 S range. Some evidence suggests that a 5 S rRNA or polysome-associated 7 S RNA could be the main endogenous primers. (Author) [pt

Histological and histoenzymatic studies on the cellular immunoreaction in Ehrlich tumor-bearing C3H/He mice exposed to various doses of local irradiation

International Nuclear Information System (INIS)

Imanaka, Kazufumi; Gose, Kyuhei; Ogawa, Yasuhiro; Imajo, Yoshinari; Kimura, Shuji; Itoh, Hiroshi.

1982-01-01

To examine the relationship between the degree of stromal reaction and the dose of irradiation applied locally to the tumor tissue, Ehrlich tumor was transplanted into the right thighs of C3H/He mice, which were subsequently irradiated with a single dose of 1,000, 2,000, 3,000 or 4,000 rad. The mice were killed 1, 3, 5, 7, 10 or 14 days after irradiation, and the resected tumor tissues were examined histologically and enzymohistochemically. The number of peripheral lymphocytes was also counted. The higher the dose of irradiation, the smaller the number of peripheral lymphocytes was observed. Lymphocytic infiltration around the tumor tissue was most intensive about 7 days after irradiation of any dose. The most intensive lymphocytic reaction was observed in the group exposed to 3,000 rad at 7 day after irradiation. Enzymohistochemical study revealed that the infiltrating lymphocytes were mostly T-lymphocytes. These results suggest that there is an optimal dose that produces the most effective cellular immune response against topical tumor cells. (author)

Chronobiological organization of reproduction of Ehrlich's ascites tumor cells

International Nuclear Information System (INIS)

Romanov, Qu.A.; Stepanenko, V.A.

1986-01-01

The rhythms of cell proliferation and DNA synthesis were studied in a hypotetraploid strain of Ehrlich's ascites tumor (EAT) and compared with data obtained previously on the hyperdiploid strain of EAT. Eighty-five noninbred male albino mice were used. An injection of tritium-thymidine, with specific radioactivity of 4.1 Ci/mmole, was given to the mice one hour before sacrifice. The results obtained are presented; it is shown that the number of DNA-synthesizing cells in the hypotetraploid strain during the 5th and 6th days of growth of EAT was 503 and 479 0 /00, respectively. Fluctuations of the radioactive index during these days were not significant. Only a significant fall in the radioactive index toward noon on the seventh day of development of the hypotetraploid strain of EAT was observed

Ameliorative influence of Urtica dioica L against cisplatin-induced toxicity in mice bearing Ehrlich ascites carcinoma.

Science.gov (United States)

Özkol, Halil; Musa, Davut; Tuluce, Yasin; Koyuncu, Ismail

2012-07-01

Cisplatin (CP) is a widely used cytotoxic agent against cancer, and high doses of CP have been known to cause nephrotoxicity and hepatotoxicity. Some reports claim that antioxidants can reduce CP-induced toxicity. This study investigated the hepatoprotective, nephroprotective, and antioxidant activity of Urtica dioica L methanolic extract (UDME) against CP toxicity in Erhlich ascites tumor (EAT)-bearing mice. Levels of serum hepatic enzymes, renal function markers, and oxidant/antioxidant parameters of liver tissue were measured. Mice were inoculated with EAT on day 0 and treated with nothing else for 24 hours. After a single dose of CP administration on day 1, the extract was given at the doses of 50, 100, 200, and 400 mg/kg body weight daily during 6 days. Almost all doses of UDME performed a significant (P < 0.05) preventive role against CP toxicity by decreasing aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, blood urea nitrogen, creatinine, lipid peroxidation, protein oxidation levels, and myeloperoxidase activity, as well as increasing reduced glutathione content, superoxide dismutase, catalase, glutathione S-transferase, and glutathione peroxidase activities. This suggests that UDME has a protective capacity and antioxidant activity against CP toxicity in EAT-bearing mice, probably by promoting antioxidative defense systems.

Incineration technology for alpha-bearing radioactive waste in Germany

International Nuclear Information System (INIS)

Dirks, Friedlich; Pfeiffer, Reinhard

1997-01-01

Since 1971 the Karlsruhe Research Center has developed and operated plants for the incineration of radioactive waste. Three incineration plants for pure β/γ solid, α-bearing solid and radioactive liquid waste have been successfully utilized during last two decades. Recently more than 20 year-old β/γ plant was shut down with the economic point of view, mainly due to the recently reduced volume of burnable β/γ waste. Burnable β/γ solid waste is now being treated with α-bearing waste in a α solid incineration plant. The status of incineration technology for α-bearing waste and other radioactive waste treatment technologies, which are now utilized in Karlsruhe Research Center, such as conditioning of incineration ash, supercompaction, scrapping, and decontamination of solid radioactive waste, etc. are introduced in this presentation. Additionally, operational results of the recently installed new dioxin adsorber and fluidized-bed drier for scrubber liquid in α incineration plant are also described in this presentation. (author) 1 tab., 13 figs

Efficiency of calcium phosphate composite nanoparticles in targeting Ehrlich carcinoma cells transplanted in mice

Directory of Open Access Journals (Sweden)

Eman I. Abdel-Gawad

2016-01-01

Full Text Available The present study aimed to investigate the mode of action of nano-CaPs in vivo as a therapy for solid tumor in mice. To achieve this goal, Ehrlich Ascites Carcinoma (EAC was transplanted into 85 Swiss male albino mice. After nine days, the mice were divided into 9 groups. Groups 1 and 2 were allocated as the EAC control. Groups 3 and 4 were injected once intratumorally (IT by nano-calcium phosphate (nano-CaP. Groups 5 and 6 received once intraperitoneal injection (IP of nano-CaP. Groups 7, 8, and 9 received nano-CaP (IP weekly. Blood samples and thigh skeletal muscle were collected after three weeks from groups 1, 3, 5, and 7 and after four weeks from groups 2, 4, 6, and 8. On the other hand, group 9 received nano-CaP (IP for four weeks and lasted for three months to follow up the recurrence of tumor and to ensure the safety of muscle by histopathological analysis. Tumor growth was monitored twice a week throughout the experiment. DNA fragmentation of tumor cells was evaluated. In thigh tissue, noradrenaline, dopamine, serotonin (5HT, and gamma-aminobutyric acid (GABA were measured. In serum, 8-Hydroxy-deoxyguanosine (8-OHDG, adenosine triphosphate (ATP, and vascular endothelial growth factor (VEGF were analyzed. Histopathological and biochemical results showed a significant therapeutic effect of nano-CaP on implanted solid tumor and this effect was more pronounced in the animals treated IP for four weeks. This improvement was evident from the repair of fragmented DNA, the significant decrease of caspase-3, 8-OHDG, myosin, and VEGF, and the significant increase of neurotransmitters (NA, DA, 5HT, and GABA. Additionally, histopathological examination showed complete recovery of cancer cells in the thigh muscle after three months.

A comparison of the performance of solid and liquid lubricants in oscillating spacecraft ball bearings

Science.gov (United States)

Gill, S.

1994-01-01

The European Space Tribology Laboratory (ESTL) has been engaged in a program to compare the performance of oscillating ball bearings when lubricated by a number of space lubricants, both liquid and solid. The results have shown that mean torque levels are increased by up to a factor of five above the normal running torque, and that often torque peaks of even greater magnitudes are present at the ends of travel. It is believed that these effects are caused by a build-up of compacted debris in the contact zone, thus reducing the ball/race conformity ratio.

Acute cholesterol depletion leads to net loss of the organic osmolyte taurine in Ehrlich Lettré tumor cells

DEFF Research Database (Denmark)

Villumsen, Kasper Rømer; Duelund, Lars; Lambert, Ian Henry

2010-01-01

In mammalian cells, the organic osmolyte taurine is accumulated by the Na-dependent taurine transporter TauT and released though the volume- and DIDS-sensitive organic anion channel. Incubating Ehrlich Lettré tumor cells with methyl-ß-cyclodextrin (5 mM, 1 h) reduces the total cholesterol pool to...

Distillation of oil-bearing minerals

Energy Technology Data Exchange (ETDEWEB)

1952-05-21

In the process of distilling oil-bearing minerals such as oil shale which disintegrates during distillation, wherein the subdivided minerals are subjected to a distillation temperature in the form of a highly turbulent dense mass fluidized by an upwardly flowing gasiform medium in a distillation zone and the heat required by the distillation is supplied by burning solid distillation residue with a combustion-supporting gas in the form of a fluidized mass of solids in a separate combustion zone at a temperature substantially higher than the distillation temperature and returning solid combustion residue substantially at the higher temperature to the distillation zone. The steps of starting up the process which consists of maintaining in the distillation and combustion zones dense turbulent fluidized beds of non-disintegrating solids, circulating the non-disintegrating solids between said beds, heating the circulating solids by an auxiliary heat supply until the bed in the distillation zone has reached at least the distillation temperature, thereafter charging fresh oil-bearing minerals to the bed in the distillation zone, continuing the circulation, withdrawing solids which have passed through the combustion zone at a rate adequate to maintain a solids balance, supplying the combustion-supporting gas to the combustion zone to cause the combustion of the residue, and discontinuing the auxilary heating when sufficient heat for the distillation is being generated in the combustion zone.

Response of the tumor and organs of the tumor-bearing animal to the action of an ionizing radiation

International Nuclear Information System (INIS)

Burlakova, E.B.; Gaintseva, V.D.; Pal'mina, N.P.; Sezina, N.P.

1977-01-01

Changes in the antioxigenic activity (AOA) of the liver of the tumor-bearing animals and the tumor have been studied after a single whole-body exposure of animals to a dose of 600 R. AOA of the liver of animals having hepatoma 22-a and Ehrlich ascites tumor (EAT) was found to decrease immediately after irradiation while that of the tumor itself can both increase (hepatoma 22-a) and decrease (EAT). Proceeding from the assumption that AOA is connected with tissue radiosensitivity it is suggested that the observed variations in the response of tumor cells and normal tissue to the action of ionizing radiation should be taken into account when developing the schemes of radiation effect on the tumor

Study of Antitumor Activity of Sodium Phenylbutyrate, Histon Deacetylase Inhibitor, on Ehrlich Carcinoma Model.

Science.gov (United States)

Fadeev, N P; Kharisov, R I; Kovan'ko, E G; Pustovalov, Yu I

2015-09-01

Antitumor activity of sodium phenylbutyrate was studied on 120 outbred female mice with transplanted Ehrlich ascites carcinoma. The animals received the drug in doses of 400, 800, and 1200 mg/kg with drinking water daily for 21 days. The antitumor effect was evaluated by tumor growth inhibition and lifespan prolongation. Phenylbutyrate in the dose of 800 mg/kg was most effective. The drug inhibited the tumor growth by 71%, prolonged the lifespan of animals by 28, and was low-toxic.

The inhibition effect of 211At-Te colloid and Na211 at injections on murine Ehrlich ascites tumor cells

International Nuclear Information System (INIS)

Wang Juan; Wang Xizhong; Zhang Jiazao

1992-01-01

Na 211 At and 211 At-Te colloid injections are prepared. It has been demonstrated that the 211 At-Te colloid is stable in vivo and in vitro, and can be applied in the study of biology and medicine. In the report, the model of Murine Ehrlich Ascites Cells cultured in vivo and in vitro is elected for a series of experiments. It has been proved that Na 211 At and 211 At-Te colloid injections possess an inhibition effect on tumor cells. The inhibition effect was expressed in surviving of the mice and inhibiting growth of tumor as well as the changes of enzyme activity. Meanwhile, it was also noticed that Na 211 At and 211 At-Te colloid injections of various dose inhibited the absorb of pyrimidine nucleosides in Murine Ehrlich Ascites Cells. And the effect is not reversible. It is closely related to the dose administrated and 50% inhibition rate needs about 1.48 x 10 5 Bq/ml culture

Application of lectins to tumor imaging radiopharmaceuticals

International Nuclear Information System (INIS)

Kojima, Shuji; Jay, M.

1986-01-01

We investigated the in vitro binding of 125 I-lectins to Ehrlich ascites tumor (EAT) cells and in vivo uptake of 125 I-lectins in Ehrlich solid tumor (EST) bearing mice. In in vitro binding assays, phaseolus vulgaris agglutinin (PHA), pisum sativum agglutinin (PSA), and concanavalia agglutinin (Con A) showed a high affinity for EAT cells. The in vivo biodistribution of 125 I-lectins showed 125 I-PSA to be significantly taken up into EST tissues 24 h postinjection. After IV injection of 125 I-PSA, uptake of the radioactivity into the tumor tissues reached a maximum at 6 h, and thereafter decreased. Rapid disappearance of the radioactivity from blood and its excretion into kidney soon after injection of 125 I-PSA were observed. When compared with the biodistribution of 67 Ga-citrate in EST bearing mice 24 h postinjection, tumor to liver (T/B), tumor to muscle (T/M), and tumor to blood (T/B) ratios were superior for 125 I-PSA. At 6 h postinjection, the T/B-ratio of 125 I-PSA was 2.5, and this value may be sufficient to enable discernable diagnostic images. Our results suggest that PSA might be a useful tumor imaging radiopharmaceutical. (orig.)

Converting Simulated Sodium-bearing Waste into a Single Solid Waste Form by Evaporation: Laboratory- and Pilot-Scale Test Results on Recycling Evaporator Overheads

Energy Technology Data Exchange (ETDEWEB)

Griffith, D.; D. L. Griffith; R. J. Kirkham; L. G. Olson; S. J. Losinski

2004-01-01

Conversion of Idaho National Engineering and Environmental Laboratory radioactive sodium-bearing waste into a single solid waste form by evaporation was demonstrated in both flask-scale and pilot-scale agitated thin film evaporator tests. A sodium-bearing waste simulant was adjusted to represent an evaporator feed in which the acid from the distillate is concentrated, neutralized, and recycled back through the evaporator. The advantage to this flowsheet is that a single remote-handled transuranic waste form is produced in the evaporator bottoms without the generation of any low-level mixed secondary waste. However, use of a recycle flowsheet in sodium-bearing waste evaporation results in a 50% increase in remote-handled transuranic volume in comparison to a non-recycle flowsheet.

Site selection factors for repositories of solid high-level and alpha-bearing wastes in geological formations

International Nuclear Information System (INIS)

1977-01-01

The purpose of this report is to provide guidelines for the selection and evaluation of suitable areas and sites for the disposal of solid high-level and alpha-bearing wastes into geological formations. This report is also intended to provide summary information on many types of geological formations underlying the land masses that might be considered as well as guidance on the geological and hydrological factors that should be investigated to demonstrate the suitability of the formations. In addition, other factors that should be considered in selecting a site for a radioactive waste repository are discussed briefly. The information, as presented, was developed to the extent of current technology for application to the evaluation of deep (greater than about 300 metres below ground level) geological formations in the selection of suitable areas for the disposal of solid or solidified high-level and alpha-bearing wastes. The extreme complexity of many geological environments and of the rock features that govern the presence and circulation of groundwater does not make it feasible to derive strict criteria for the selection of a site for a radioactive waste repository in a geological formation. Each potential repository location must be evaluated according to its own unique geological and hydrological setting. Therefore, only general guidance is offered, and this is done through discussion of the many factors that need to be considered in order to obtain the necessary assurances that the radionuclides will be confined in the geological repository over the required period of time

Site selection factors for repositories of solid high-level and alpha-bearing wastes in geological formations

Energy Technology Data Exchange (ETDEWEB)

1977-01-01

The purpose of this report is to provide guidelines for the selection and evaluation of suitable areas and sites for the disposal of solid high-level and alpha-bearing wastes into geological formations. This report is also intended to provide summary information on many types of geological formations underlying the land masses that might be considered as well as guidance on the geological and hydrological factors that should be investigated to demonstrate the suitability of the formations. In addition, other factors that should be considered in selecting a site for a radioactive waste repository are discussed briefly. The information, as presented, was developed to the extent of current technology for application to the evaluation of deep (greater than about 300 meters below ground level) geological formations in the selection of suitable areas for the disposal of solid or solidified high-level and alpha-bearing wastes. The extreme complexity of many geological environments and of the rock features that govern the presence and circulation of groundwater does not make it feasible to derive strict criteria for the selection of a site for a radioactive waste repository in a geological formation. Each potential repository location must be evaluated according to its own unique geological and hydrological setting. Therefore, only general guidance is offered, and this is done through discussion of the many factors that need to be considered in order to obtain the necessary assurances that the radionuclides will be confined in the geological repository over the required period of time.

On indicators of genetic relation between uranium-bearing bitumen with oil-like substances

International Nuclear Information System (INIS)

Pen'kov, V.F.

1980-01-01

Mineralogical indicators are considered which confirm that uranium-bearing (containing pitchblende) solid carbon substrates in the process of their formation had a stage of liquid-viscous state, and were sedimented in a close association with solid oil bitumens. The following cases are studied: 1) in concentrated macroextracts of uranium-bearing bitumens fine relicts of coloured oreless bitumens, less oxidated and carbonizated, are found sporadically in the passing light; 2) indicators of the development of black uranium-bearing bitumen along separate extracts or joint agregates of kerito- and asphalt-like substrates are observed in passing light within the veinlets of solid bitumens being in carbonate rocks; 3) linses of solid bitumens of fragmentary rock have zone structure according to the observation in passing light. The direct relation between black uranium-bearing bitumens and solid hydrocarbons which can form out of oil-like substances. Initial substances for them were defferent; resinous bitumens in the first case, kerito- and asphalt-like substances - in the second one, and paraffin substances - in the third one. It shows the nonselective character of the formation out of them of black uranium-bearing bitumens due to the processes of oxidation and carbonization [ru

Natural killer cell activity, lymphocyte proliferation, and cytokine profile in tumor-bearing mice treated with MAPA, a magnesium aggregated polymer from Aspergillus oryzae.

Science.gov (United States)

Justo, G Z; Durán, N; Queiroz, M L S

2003-08-01

The present study examined the effects of MAPA, an antitumor aggregated polymer of protein magnesium ammonium phospholinoleate-palmitoleate anhydride, isolated from Aspergillus oryzae, on concanavalin A (Con A)-induced spleen cell proliferation, cytokine production and on natural killer (NK) cell activity in Ehrlich ascites tumor-bearing mice. The Ehrlich ascites tumor (EAT) growth led to diminished mitogen-induced expansion of spleen cell populations and total NK activity. This was accompanied by striking spleen enlargement, with a marked increase in total cell counts. Moreover, a substantial enhancement in IL-10 levels, paralleled by a significant decrease in IL-2 was observed, while production of IL-4 and interferon-gamma (IFN-gamma) was not altered. Treatment of mice with 5 mg/kg MAPA for 7 days promoted spleen cell proliferation, IL-2 production and NK cell activity regardless of tumor outgrowth. In addition, MAPA treatment markedly enhanced IFN-gamma levels and reduced IL-10 production relative to EAT mice. A 35% reduction in splenomegaly with normal number of nucleated cells was also found. Altogether, our results suggest that MAPA directly and/or indirectly modulates immune cell activity, and probably disengages tumor-induced suppression of these responses. Clearly, MAPA has an impact and may delay tumor outgrowth through immunotherapeutic mechanisms.

L-Arginine Increases Cytotoxicity in Irradiated Ehrlich Carcinoma Cell Line: Possible Potential Role of Nitric Oxide

International Nuclear Information System (INIS)

Noaman, E.

2008-01-01

Cancer cells possess nitric oxide syntheses (NOS) which metabolize L-Arginine (L-Arg) for producing nitric oxide (NO) The present study investigates the relations between NO and ionizing radiation in the Ehrlich ascites carcinoma (EAC) cell line. NOS activity was stimulated by exposure of cells to L-Arg just after irradiation. L-Arg (5 m M) supply led to an increase in ionizing radiation induced cytotoxicity (% of viability 18± 3 %) whereas, neither L-Arg itself nor ionizing irradiation caused cell death at the doses used in this study. Also, cells were treated either with L-Thio citrulline (L-Thio), an irreversible inhibitor of NOS or with exogenous superoxide dismutase (SOD) and catalase. L-Thio and SOD prevented L-Arg mediated deleterious effects on Irradiated cells, whereas catalase was ineffective. Intracellular antioxidant enzyme activity was also determined. Ionizing radiation + L-Arg stress altered the activity of catalase (66 % decrease) and glutathione peroxidase (83 % decrease). Our findings demonstrated that L-Arg induces increase the radiation-mediated deleterious effects in Ehrlich ascites carcinoma cells cytotoxicity and that the ratio NO/ O 2 plays a key role in these processes. NO could participate the deleterious effect of irradiation, in conjugation with others reactive oxygen species (ROS) produced during the oxidation of intracellular components by ionizing radiation (dose 6 Gy)

Repair in Ehrlich ascites tumor cells

International Nuclear Information System (INIS)

Wanna-Nakamura, S.S.

1981-01-01

Unscheduled DNA synthesis (UDS), an indicator of excision repair, was induced in freshly drawn Ehrlich ascites tumor cells (EAT), using ionizing radiation, far ultraviolet light (254 nm) or near uv light (365 nm) in combination with 8-methoxypsoralen. UDS was scored by grain counts in autoradiographs following the incorporation of tritium-labelled thymidine. The amount of UDS after each of these agents was expressed in terms of two parameters, viz. numer of cells showing repair and the mean number of grains per nucleus. The influence of radiation dose and of the duration of radioactive thymidine incubation were also examined. To test for a possible relationship between low mitotic index and repair capability, EAT cells were incubated in buffered salt media to lower the mitotic index. Cells kept in a buffered salt solution for 7 h show a marked drop in mitotic index compared to those incubated in minimal medium containing 15% fetal calf serum (MEM + FCS). This drop in mitotic index was reversible for up to 5 h, if cells were returned to MEM + FCS. Cells incubated in MEM + FCS also showed a decrease in mitotic activity compared to freshly drawn cells. This reduced mitotic index is approximately constant for up to 24 h. With the drop in mitotic index, EAT cells also show a drop in repair compared to freshly drawn cells. The repair capability of cells incubated in buffer can be restored by returning cells to MEM + FCS

In vitro binding of 67Ga to Ehrlich ascites tumor cells

International Nuclear Information System (INIS)

Kojima, S.; Kubodera, A.

1984-01-01

The binding of 67 Ga to Ehrlich ascites tumor cells (ETC) was studied in vitro. Acid mucopolysaccharide (AMPS) present at the cell surface of ETC was identified as heparan sulfate (HS). The extent of 67 Ga binding to ETC reached a plateau (ca. 10% of the added dose) at 1-2 h after the start of incubation. The binding was higher under neutral or alkaline conditions than under acidic conditions. Heparin and heparitinase treatment both significantly decreased the extent of 67 Ga binding to ETC. Mild treatment with protease, including trypsin or papain, also decreased the binding. On the contrary, the treatment with trypsin under severe conditions markedly increased the extent of 67 Ga binding to ETC. These results support the hypothesis that HS plays an important role as a 67 Ga receptor in the mechanism of gallium binding to ETC. (orig.)

Characterisation of non-P-glycoprotein multidrug-resistant Ehrlich ascites tumour cells selected for resistance to mitoxantrone

DEFF Research Database (Denmark)

Nielsen, D; Eriksen, J; Maare, C

2000-01-01

An Ehrlich ascites tumour cell line (EHR2) was selected in vivo for resistance to mitoxantrone (MITOX). The resistant cell line (EHR2/MITOX) was 6123-, 33-, and 30-fold-resistant to mitoxantrone, daunorubicin, and etoposide, respectively, but retained sensitivity to vincristine. The resistant cel...... to be associated with: 1) a quantitative reduction in topoisomerase IIalpha and beta protein; 2) reduced drug accumulation, probably as a result of increased expression of a novel transport protein with ATPase activity; and 3) increased expression of MRP mRNA....

Natural and semi-synthetic clerodanes of Croton cajucara and their cytotoxic effects against ehrlich carcinoma and human K562 leukemia cells

Energy Technology Data Exchange (ETDEWEB)

Maciel, Maria Aparecida M. [Universidade Federal do Rio Grande do Norte, Natal, RN (Brazil). Dept. de Quimica; Martins, Jenilce R.; Pinto, Angelo C.; Kaiser, Carlos R. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Quimica; Esteves-Souza, Andressa; Echevarria, Aurea [Universidade Federal Rural do Rio de Janeiro, Seropedica, RJ (Brazil). Dept. de Quimica]. E-mail: echevarr@ufrrj.br

2007-03-15

The clerodane-type diterpene, trans-dehydrocrotonin (1) the major component of Croton cajucara has shown striking correlation with its therapeutic use in traditional folk medicine. Phytochemical investigations led to the isolation of the metabolites 1, cajucarinolide (6), isocajucarinolide (7), trans-crotonin (2), trans-cajucarin B (3), cis-cajucarin B (4), trans-cajucarin A (5), N-methyltyrosine, vanillic acid and 4-hydroxy-benzoic acid. 6 and 7 were synthesized in good yield by regiospecific oxidation of 1 using singlet-oxygen. All clerodanes were studied for their cytotoxic effects against human K562 leukemia and Ehrlich carcinoma cells. Ehrlich carcinoma assays with IC{sub 50} = 166 {mu}M (1), 164 {mu}M (2), 65 {mu}M (6) and 10 {mu}M (7) related to cell growth inhibitory effects were dose dependent. Furthermore, moderate cytotoxic activity against K562 leukemia cells was observed with IC{sub 50} = 38 {mu}M (3), 33 {mu}M (5), 36 {mu}M (6) and 43 {mu}M (7). The semi-synthetic 2, 6 and 7 showed similar results when compared to the corresponding natural clerodanes. (author)

Natural and semi-synthetic clerodanes of Croton cajucara and their cytotoxic effects against ehrlich carcinoma and human K562 leukemia cells

International Nuclear Information System (INIS)

Maciel, Maria Aparecida M.; Martins, Jenilce R.; Pinto, Angelo C.; Kaiser, Carlos R.; Esteves-Souza, Andressa; Echevarria, Aurea

2007-01-01

The clerodane-type diterpene, trans-dehydrocrotonin (1) the major component of Croton cajucara has shown striking correlation with its therapeutic use in traditional folk medicine. Phytochemical investigations led to the isolation of the metabolites 1, cajucarinolide (6), isocajucarinolide (7), trans-crotonin (2), trans-cajucarin B (3), cis-cajucarin B (4), trans-cajucarin A (5), N-methyltyrosine, vanillic acid and 4-hydroxy-benzoic acid. 6 and 7 were synthesized in good yield by regiospecific oxidation of 1 using singlet-oxygen. All clerodanes were studied for their cytotoxic effects against human K562 leukemia and Ehrlich carcinoma cells. Ehrlich carcinoma assays with IC 50 = 166 μM (1), 164 μM (2), 65 μM (6) and 10 μM (7) related to cell growth inhibitory effects were dose dependent. Furthermore, moderate cytotoxic activity against K562 leukemia cells was observed with IC 50 = 38 μM (3), 33 μM (5), 36 μM (6) and 43 μM (7). The semi-synthetic 2, 6 and 7 showed similar results when compared to the corresponding natural clerodanes. (author)

The relationship between DNA synthesis and incorporation of (14C) lysine into different histone fractions in Ehrlich ascites tumour cells

International Nuclear Information System (INIS)

Malec, J.; Kornacka, L.; Wojnarowska, M.; Moscicka, M.

1974-01-01

The effect of inhibition of DNA synthesis by hydroxyurea on ( 14 C) lysine incorporation into the main four histone fractions in Ehrlich ascites tumor cells, was examined in vitro. The radioactivity of lysine-rich histones, especially of histone f1, was preferentially decreased. The smallest decrease was observed for histone f3. The incorporation into other cellular proteins was but slightly affected. (author)

New volume reduction conditioning options for solid alpha-bearing waste

International Nuclear Information System (INIS)

Jouan, A.; Jacquet-Francillon, N.; Kertesz, C.; Frotscher, H.; Ganser, B.; Klein, M.

1990-01-01

The current and future development of nuclear energy requires increasing allowance for nuclear waste treatment: α-bearing wastes destined for geological storage are already conditioned, generally in a cement matrix. Other containment processes producing higher quality matrices and allowing volume reduction have been investigated over the last five years by the General Directorate for Science Research and Development of the Commission of the European Communities. This paper discusses the work on conditioning α-bearing ashes produced by incineration of contaminated combustible materials, and on fuel cladding hulls resulting from spent fuel reprocessing

Diagnostic evaluation of rolling behavior in ball bearings by ultrasonic technique

International Nuclear Information System (INIS)

Wakabayashi, T

2012-01-01

Failures of machines having rotating parts are mostly caused by damage to bearings and there exist increasing demands for detecting damaged bearings at an early stage. However, conventional diagnostic methods, such as measuring temperature and observing vibration, have found difficulties in performing the early detection, so that more advanced diagnosis is necessary. This study therefore applies an ultrasonic technique as an advanced diagnostic method to bearing life tests. Ultrasonic wave pulses (UWP) emitted from a piezoelectric UWP generator can partially reflect from the interfaces of contact zones within the housing and the bearing with regard to the different acoustic impedance between a solid-to-solid contact and a contact dominated by some fluid layers. Hence, the intensity of the resultant UWP echoes can be determined by the real contact area formed at the interfaces. The experimental results of UWP echoes under the different operating conditions have demonstrated that the time intervals between peaks of UWP echoes varied in accordance with the movement of rolling balls and the lubricating phenomena in bearings. This behavior has further suggested the possibility of the early detection of abnormalities in ball bearings by using the variation in UWP echoes.

Dynamics of Ca2+i and pHi in Ehrlich ascites tumor cells after Ca2+-mobilizing agonists or exposure to hypertonic solution

DEFF Research Database (Denmark)

Pedersen, Stine F.; Jørgensen, Nanna K.; Hoffmann, Else Kay

1998-01-01

Intracellular free calcium concentration ([Ca2+]i) and intracellular pH (pHi) were monitored in Ehrlich ascites tumor cells using Fura-2 or 2',7',-bis-(2-carboxyethyl)-5,6-carboxyfluorescein (BCECF), or both probes in combination. An increase in [Ca2+]i induced by thrombin or bradykinin, agonists...

RNA and protein synthesis of irradiated Ehrlich ascites tumour cells. Pt. 2

International Nuclear Information System (INIS)

Skog, S.; Tribukait, B.; Nygard, O.; Wenner-Gren-Center foer Vetenskaplig Forskning, Stockholm

1985-01-01

Poly(A)-containing RNA (m-RNA) was studied in in vivo growing Ehrlich ascites tumour cells following a roentgen irradiation dose of 5 Gy. m-RNA increased significantly during the first 12 hours after irradiation. Thus, the observed decrease in protein synthesis rate during this time seems not to be due to radiation induced changes at the transcriptional level. The protein synthesis rate of in vivo irradiated cells incubated in vitro in culture medium was unchanged. On the other hand, the protein synthesis rate of non-irradiated cells incubated in vitro in ascites fluid from irradiated animals was decreased. We concluded that factor(s) inhibiting protein synthesis or the lack of factor(s) promoting protein synthesis in the ascites fluid is(are) of significance for the reduced protein synthesis of tumour cells found in irradiated in vivo growing cells. (orig.)

The R and D D's bearing test benches

International Nuclear Information System (INIS)

Vialettes, J.M.

1997-01-01

In power generation plants, rotating machines are involved in energy transformation processes and safety systems. The bearings supporting the rotors and the thrust bearings play a crucial role in the reliability of these machines. The phenomena encountered straddle several disciplines: hydrodynamics, tribology, thermomechanics, materials and vibrations in a specific environment, namely: thin fluid film, solid mechanical components and shaft rotation. Means of analysing the behaviour of these components (bearings and thrust bearings) have been developed and implemented. These consists of the EDYOS (Etude Dynamique des Organes de Supportage) code for dynamically studying bearing devices and several related bench tests. In reality, in order to understand the complex physical phenomena encountered in these components, it is vital to carry out analyses and experimental validations. Since these investigations cannot be carried out on actual machines, test benches have been built which can subject the sample bearings to the equivalent stresses. (author)

Isotope inequilibrium of glucose metabolites in intact cells and particlefree supernatants of Ehrlich ascites tumor

International Nuclear Information System (INIS)

Daehnfeldt, J.L.; Winge, P.

1975-01-01

With an enzyme degradative technique, isotope inequilibrium of glucose metabolites was demonstrated in intact cells and particle-free supernatants of Ehrlich ascites tumor using I- 14 C-glucose as tracer. Inequilibrium was found between glucose and glucose-6-phosphate, glucose and fructose-6-phosphate, glucose and 6-phosphogluconate, while glucose-6-phosphate and fructose-6-phosphate were found to be in near equilibrium within the incubation time investigated. Glucose and lactate were found to be in near equilibrium after 8 min in intact cells. Calculations based on the equilibrium levels found, showed that these inequilibria could not be explained by the effects of the pentose cycle. (U.S.)

A cell shrinkage-induced non-selective cation conductance with a novel pharmacology in Ehrlich-Lettre-ascites tumour cells

DEFF Research Database (Denmark)

Lawonn, Peter; Hoffmann, Else K; Hougaard, Charlotte

2003-01-01

In whole-cell recordings on Ehrlich-Lettre-ascites tumour (ELA) cells, the shrinkage-induced activation of a cation conductance with a selectivity ratio P(Na):P(Li):P(K):P(choline):P(NMDG) of 1.00:0.97:0.88:0.03:0.01 was observed. In order of potency, this conductance was blocked by Gd(3+)=benzam......-sensitive and -insensitive channels. In addition, because of its pharmacological profile, it may possibly be related to epithelial Na+ channels (ENaCs)....

Characterisation of a cell swelling-activated K⁺-selective conductance of Ehrlich mouse ascites tumour cells

DEFF Research Database (Denmark)

Niemeyer, María Isabel; Hougaard, Charlotte; Hoffmann, Else Kay

2000-01-01

activated by cell swelling was measured as outward current at the Cl- equilibrium potential (ECl) under quasi-physiological gradients. It could be abolished by replacing extracellular Na+ with K+, thereby cancelling the driving force. Replacement with other cations suggested a selectivity sequence of K......+ currents of Ehrlich cells are voltage and calcium insensitive and are resistant to a range of K+ channel inhibitors. These characteristics are similar to those of the so-called background K+ channels. 6.  Noise analysis of whole-cell current was consistent with a unitary conductance of 5.5 p...

Relationship between accumulation of rare earth element in tumor and ionic radius

Energy Technology Data Exchange (ETDEWEB)

Kataoka, N [Kanazawa Univ. (Japan). School of Medicine

1975-02-01

The accumulation of rare earth elements in the different organs of Ehrlich's tumor-bearing mice at 48 hours after intraperitoneal administration was measured by a Ge(Li) semiconductor detector. Accumulation of all the rare earth elements was the highest in the pancreas. Accumulation of /sup 152/Eu in the different organs of Ehrlich's tumor-bearing mice was very high. The accumulation of rare earth elements in Ehrlich's tumor was lower than the accumulation of /sup 67/Ga and /sup 46/Sc. The tumor-organ concentration ratio of rare earth elements was remarkably lower than the accumulation of /sup 67/Ga and /sup 46/Sc. However, the accumulation of /sup 152/Eu in Ehrlich's tumor was somewhat higher than that of /sup 67/Ga. The relationship between the accumulation and the carrier content was examined. The lower the carrier content was, the higher was the accumulation in different organs. However, the carrier effect of rare earth on the uptake in different organs elements was slight. The author postulated that the elements in which the ionic radius is similar to that of Mg(0.62 A) or Ca(0.99 A) are abundant in the tumor cell membrane, and they might pass through the tumor cell membrane much more easily than would the other elements. However, the result was negative.

Fatigue Analysis of an Outer Bearing Bush of a Kaplan Turbine

Directory of Open Access Journals (Sweden)

Doina Frunzaverde

2011-01-01

Full Text Available The paper presents the fatigue analysis of an outer bearing bush of aKaplan turbine. This outer bush, together with an inner one, bear thepin lever - trunion - blade subassembly of the runner blade operatingmechanism. For modeling and simulation, SolidWorks software is used.

Luminol-dependent chemiluminescence in antibody-sensitized neutrophils stimulated with protein A-bearing staphylococci.

Science.gov (United States)

Nishihara, S; Seki, K; Ikigai, H; Masuda, S

1988-01-01

When mouse polymorphonuclear leukocytes (PMNs) sensitized with rabbit antibody to mouse Ehrlich ascites tumor cells were stimulated by Staphylococcus aureus Cowan I cells, a conspicuous luminol-dependent chemiluminescence was observed in the absence of opsonin. The profile of the chemiluminescence (CL) response evoked by staphylococcal cells from antibody-sensitized PMNs had two peaks. An initial peak, observed within 1 min after stimulation, was sharp and high and a second peak, observed about 5 min after stimulation, was low and extended. The CL response of antibody-sensitized PMNs stimulated by S. aureus Cowan I cells was dose-dependently blocked by preincubation with soluble SpA. Cells of a mutant derived from S. aureus Cowan I strain with trace amounts of cell-bound SpA failed to stimulate the antibody-sensitized PMNs to generate the CL response. The antibody-sensitized PMNs were found to phagocytize SpA-bearing S. aureus cells even in the absence of opsonic serum. These results suggest that the observation presented here might provide a useful tool for the investigation of CL response of PMNs.

Mathematical simulation of bearing ring grinding process

Science.gov (United States)

Koltunov, I. I.; Gorbunova, T. N.; Tumanova, M. B.

2018-03-01

The paper suggests the method of forming a solid finite element model of the bearing ring. Implementation of the model allowed one to evaluate the influence of the inner cylindrical surface grinding scheme on the ring shape error.

On-line surveillance of lubricants in bearings by means of surface acoustic waves.

Science.gov (United States)

Lindner, Gerhard; Schmitt, Martin; Schubert, Josephine; Krempel, Sandro; Faustmann, Hendrik

2010-01-01

The acoustic wave propagation in bearings filled with lubricants and driven by pulsed excitation of surface acoustic waves has been investigated with respect to the presence and the distribution of different lubricants. Experimental setups, which are based on the mode conversion between surface acoustic waves and compression waves at the interface between a solid substrate of the bearing and a lubricant are described. The results of preliminary measurements at linear friction bearings, rotation ball bearings and axial cylinder roller bearings are presented.

Effect of fast electrons and menadione on the structural and functional status of Ehrlich ascites tumor cells at early periods following irradiation

International Nuclear Information System (INIS)

Sejlanov, A.S.

1989-01-01

Irradiation of Ehrlich ascites tumor cells stimulates oxygen consumption, and menadione supresses cell respiration. The combined effect of the two factors produces an additional, in comparison with the effect of menadione alone, inhibition of the rate of oxygen consumption by cells. There is an additive effect of radiation and menadione with regard to the level of cell thiols and interphase cell death

The effect of phosphoethanolamine intake on mortality and macrophage activity in mice with solid ehrlich tumors

Directory of Open Access Journals (Sweden)

Maria Sueli Parreira de Arruda

2011-12-01

Full Text Available The aim of the present study was to examine the effect of a diet rich in synthetic PEtn on the metabolism macrophages of tumor-bearing mice. The results demonstrated that PEtn increased the animals' survival time. In addition, the treated animals released smaller amounts of hydrogen peroxide (H2O2 and nitric oxide (NO than the non-treated animals, particularly after day 14. From the results it could be concluded that H2O2 and NO were important in the modulation of neoplastic growth, and pointed to a promising role of PEtn in the control of human neoplasms.

O tumor experimental de Ehrlich induz comportamento nociceptivo em camundongos : padronização de um novo modelo para o estudo da fisiopatologia da dor no câncer e triagem de analgésicos

OpenAIRE

Cássia Calixto de Campos

2013-01-01

A dor afeta diretamente a qualidade de vida dos pacientes com câncer o que ressalta a importância deste campo de pesquisa. O tumor de Ehrlich foi descrito em 1905 como um adenocarcinoma mamário de camundongos fêmeas e pode ser desenvolvido em formas sólidas e ascítica, dependendo da administração em tecidos ou cavidades, respectivamente. O presente estudo investigou se a administração subcutânea plantar das células tumorais de Ehrlich induz o comportamento da dor manifesta (agitação da pata),...

Mechanisms of activation of NHE by cell shrinkage and by calyculin A in Ehrlich ascites tumor cells

DEFF Research Database (Denmark)

Pedersen, Stine Helene Falsig; Varming, Camilla; Hoffmann, E K

2002-01-01

The Na+/H+ exchanger isoforms NHE1, NHE2, and NHE3 were all found to be expressed in Ehrlich ascites tumor cells, as evaluated by Western blotting and confocal microscopy. Under unstimulated conditions, NHE1 was found predominantly in the plasma membrane, NHE3 intracellularly, and NHE2 in both co....... It is concluded that shrinkage-induced NHE activation is dependent on PKC and p38 MAPK, but not on MLCK or ERK1/2. NHE activity under both iso- and hypertonic conditions is increased by inhibition of serine/threonine phosphatases, and this effect appears to be PKC-dependent....

Selective incorporation of various C-22 polyunsaturated fatty acids in Ehrlich ascites tumor cells

International Nuclear Information System (INIS)

Masuzawa, Y.; Okano, S.; Waku, K.; Sprecher, H.; Lands, W.E.

1986-01-01

Three 14 C-labeled 22-carbon polyunsaturated fatty acids, 7,10,13,16-[ 14 C]docosatetraenoic acid (22:4(n-6)), 7,10,13,16,19-[ 14 C]docosapentaenoic acid (22:5(n-3)), and 4,7,10,13,16,19-[ 14 C]docosahexaenoic acid (22:6(n-3)), were compared with [ 3 H]arachidonic acid (20:4(n-6] and [14C]linoleic acid (18:2(n-6)) to characterize their incorporation into the lipids of Ehrlich ascites cells. The relatively rapid incorporation of the labeled 22-carbon acids into phosphatidic acid indicated that substantial amounts of these acids may be incorporated through the de novo pathway of phospholipid synthesis. In marked contrast to 20:4(n-6), the 22-carbon acids were incorporated much less into choline glycerophospholipids (CGP) and inositol glycerophospholipids (IGP). No selective preference was apparent for the (n-3) or (n-6) type of fatty acids. The amounts of the acids incorporated into diacylglycerophosphoethanolamine were in the order of: 22:6(n-3) greater than 20:4(n-6) much greater than 22:5(n-3) greater than or equal to 22:4(n-6) greater than 18:2(n-6), whereas for alkylacylglycerophosphoethanolamine they were in the order of: 22:4(n-6) greater than 22:6(n-3) greater than 22:5(n-3) much greater than 20:4(n-6) greater than 18:2(n-6). Of the mechanisms possibly responsible for the selective entry of 22-carbon acids into ethanolamine glycerophospholipids, the most reasonable explanation was that the cytidine-mediated ethanolamine phosphotransferase may have a unique double selectivity: for hexaenoic species of diacylglycerol and for 22-carbon polyunsaturated fatty acid-containing species of alkylacylglycerol. The relative distribution of fatty acids between newly incorporated and already maintained lipid classes suggested that IGP may function in Ehrlich cells as an intermediate pool for the retention of polyunsaturated fatty acids in glycerolipids

Distillation of oil-bearing minerals

Energy Technology Data Exchange (ETDEWEB)

1952-12-03

A process of distilling oil-bearing minerals of the type of oil shale which disintegrate during distillation consists of subjecting the subdivided minerals to a distillation temperature in the form of a highly turbulent dense mass fluidized by an upwardly flowing gasiform medium in a distillation zone and supplying the heat required for the distillation by burning solid distillation residue with a combustion-supporting gas in the form of a fluidized mass of solids in a separate combustion zone at a combustion temperature and returning solid combustion residue substantially at the combustion temperature to the distillation zone. Combustion temperature is positively maintained at a figure not exceeding 1,200/sup 0/F and at a figure which is not substantially more than 50/sup 0/F higher than the distillation temperature.

Anti-tumour action of 64Cu-bleomycin on Ehrlich ascites tumour cells in vivo

International Nuclear Information System (INIS)

Maki, Hirotoshi; Kawai, Kenichi; Akaboshi, Mitsuhiko

1979-01-01

The anti-tumor action of the complex of Bleomycin (BLM) with high specific-radioactivity 64 Cu on Ehrlich ascites tumour (EAT) was studied in vivo. The 64 Cu-BLM was administered into intraperitoneal cavity of mice from 1 to 4 days after inoculation of EAT cells. The effect of 64 Cu-BLM to suppress the tumour growth as demonstrated by prolonging life span was observed. The amounts of 64 Cu-BLM (800 μCi-8 mg/Kg) were administered at 4, 8 and 16 times separately. Then, the shorter the time interval and the less the amounts of drugs at a time, the higher the suppressing effect for the tumour growth was. It was confirmed that anti-tumour action of 64 Cu-BLM was in all the cases higher than that of BLM alone. (author)

ROS activate KCl cotransport in nonadherent Ehrlich ascites cells but K⁺ and Cl^- channels in adherent Ehrlich Lettré and NIH3T3 cells

DEFF Research Database (Denmark)

Lambert, Ian Henry; Klausen, Thomas Kjær; Bergdahl, Andreas

2009-01-01

Addition of H2O2 (0.5 mM) to Ehrlich ascites tumor cells under isotonic conditions results within 25 min in a substantial (22 +/- 1 %) reduction in cell volume. The cell shrinkage is paralleled by net loss of K(+), which was significant within 8 min, whereas no concomitant increase in the K......(+) or Cl(-) conductances could be observed. The H2O2-induced cell shrinkage was unaffected by the presence of clofilium and clotrimazole, that block volume-sensitive and Ca(2+)-activated K(+) channels, respectively, and unaffected by a raise in extracellular K(+) concentration to a value which eliminates...... the electrochemical driving force for K(+). On the other hand, the H2O2-induced cell shrinkage was impaired in the presence of the KCl cotransport inhibitor DIOA, following substitution of NO3(-) for Cl(-), and when the driving force for KCl cotransport was omitted. It is suggested that H2O2 activates electro neutral...

Evaluation of antitumor activity and in vivo antioxidant status of Anthocephalus cadamba on Ehrlich ascites carcinoma treated mice.

Science.gov (United States)

Dolai, Narayan; Karmakar, Indrajit; Suresh Kumar, R B; Kar, Biswakanth; Bala, Asis; Haldar, Pallab Kanti

2012-08-01

Anthocephalus cadamba (Roxb.) Miq. (Family: Rubiaceae) is commonly known as "Kadamba" in Sanskrit and Hindi in India. Various parts of this plant have been used as a folk medicine for the treatment of tumor, wound healing, inflammation and as a hypoglycemic agent. The purpose of this investigation was to evaluate the antitumor activity and antioxidant status of defatted methanol extract of A. cadamba (MEAC) on Ehrlich ascites carcinoma (EAC) treated mice. In vitro cytotoxicity assay has been evaluated by using the trypan blue method. The determination of in vivo antitumor activity was performed by using different EAC cells (2 × 10(6) cells, i.p.) inoculated mice groups (n=12). The groups were treated for 9 consecutive days with MEAC at the doses of 200 and 400 mg/kg b.w. respectively. After 24h of last dose and 18 h of fasting, half of the mice were sacrificed and the rest were kept alive for assessment of increase in life span. The antitumor potential of MEAC was assessed by evaluating tumor volume, viable and nonviable tumor cell count, tumor weight, hematological parameters and biochemical estimations. Furthermore, antioxidant parameters were assayed by estimating liver and kidney tissue enzymes. MEAC showed direct cytotoxicity on EAC cell line in a dose dependant manner. MEAC exhibited significant (P<0.01) decrease in the tumor volume, viable cell count, tumor weight and elevated the life span of EAC tumor bearing mice. The hematological profile, biochemical estimations and tissue antioxidant assay were reverted to normal level in MEAC treated mice. Experimental results revealed that MEAC possesses potent antitumor and antioxidant properties. Further research is going on to find out the active principle(s) of MEAC for better understanding of mechanism of its antitumor and antioxidant activity. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Effect of Bearing Housings on Centrifugal Pump Rotor Dynamics

Science.gov (United States)

Yashchenko, A. S.; Rudenko, A. A.; Simonovskiy, V. I.; Kozlov, O. M.

2017-08-01

The article deals with the effect of a bearing housing on rotor dynamics of a barrel casing centrifugal boiler feed pump rotor. The calculation of the rotor model including the bearing housing has been performed by the method of initial parameters. The calculation of a rotor solid model including the bearing housing has been performed by the finite element method. Results of both calculations highlight the need to add bearing housings into dynamic analyses of the pump rotor. The calculation performed by modern software packages is more a time-taking process, at the same time it is a preferred one due to a graphic editor that is employed for creating a numerical model. When it is necessary to view many variants of design parameters, programs for beam modeling should be used.

Decontamination of alpha-bearing solid wastes and plutonium recovery

International Nuclear Information System (INIS)

Koehly, G.; Madic, C.; Lecomte, M.; Bourges, J.; Saulze, J.L.; Broudic, J.C.

1993-01-01

Nuclear activities in the Radiochemistry building of Fontenay-aux-Roses Nuclear Research Center concern principally the study of fuel reprocessing and the production of transuranium isotopes. During these activities solid wastes are produced. In order to improve the management of these wastes, it has been decided to build new facilities: a group of three glove-boxes named ELISE for the treatment of α active solid waste and a hot-cell, PROLIXE, for the treatment of solid wastes. Leaching processes were developed in order to: decontaminate these wastes and recover actinide elements, particularly the highly valuable plutonium, from the leachates. The processes developed are sufficiently flexible to be able to accommodate solid wastes produced in other facilities. Laboratory studies were conducted to develop the leaching process based on the use of electrogenerated Ag(II) species which is particularly suitable to provoke the dissolution of PuO 2 . Successful exhaustive Pu decontaminations with DF(Pu) higher than 10 4 were achieved for the first time during the treatment of stainless steel PuO 2 cans (future MELOX plant) by electrogenerated Ag (II) in nitric acid medium

Experimental study on combination of chemotherapy and radiotherapy

International Nuclear Information System (INIS)

Tanaka, Juichi

1986-01-01

Recently, by applying multidrug therapy using cisplatin and bleomycin to the treatment of head and neck cancer, the response rate of chemotherapy has been markedly increased and thus, chemotherapy has taken an important part in the treatment of head and neck cancer. In this paper a clinical application of chemotherapy in combination with radiotherapy was evaluated from the point of the cure rate and also preservation of the structures and the functions of the head and neck region. In order to test the advantage or usefulness of initial chemotherapy followed by radiotherapy (= pre-radiation chemotherapy), the experimental study on combination of chemotherapy and radiotherapy was designed by using ICR mice and Ehrlich solid carcinoma. Cisplatin and peplomycin, a newly developed derivative of bleomycin, were used as chemotherapeutic agents. Tumor growth delay rate was chosen as a parameter to indicate the effectiveness. Results obtained are as follows. 1. Combination chemotherapy of cisplatin and peplomycin was more effective than each single agent on Ehrlich solid carcinoma. Synergistic effect was obtained by higher dose. So, the combination of cisplatin and peplomycin was proved to be eligible for pre-radiation chemotherapy. 2. Synergistic effect of chemotherapy and radiotherapy was observed when chemotherapy was used prior to radiotherapy on Ehrlich solid carcinoma. 3. Even their additional effect was not recognized when radiotherapy preceded to chemotherapy on Ehrlich solid carcinoma. 4. No severe toxic effect was seen in the mice. The experimental results made it clear that pre-radiation chemotherapy is beneficial to the treatment of head and neck cancer. (author)

Candida glabrata tryptophan-based pigment production via the Ehrlich pathway.

Science.gov (United States)

Brunke, Sascha; Seider, Katja; Almeida, Ricardo Sergio; Heyken, Antje; Fleck, Christian Benjamin; Brock, Matthias; Barz, Dagmar; Rupp, Steffen; Hube, Bernhard

2010-04-01

Pigments contribute to the pathogenicity of many fungi, mainly by protecting fungal cells from host defence activities. Here, we have dissected the biosynthetic pathway of a tryptophan-derived pigment of the human pathogen Candida glabrata, identified key genes involved in pigment production and have begun to elucidate the possible biological function of the pigment. Using transcriptional analyses and a transposon insertion library, we have identified genes associated with pigment production. Targeted deletion mutants revealed that the pigment is a by-product of the Ehrlich pathway of tryptophan degradation: a mutant lacking a tryptophan-upregulated aromatic aminotransferase (Aro8) displayed significantly reduced pigmentation and a recombinantly expressed version of this protein was sufficient for pigment production in vitro. Pigment production is tightly regulated as the synthesis is affected by the presence of alternative nitrogen sources, carbon sources, cyclic AMP and oxygen. Growth of C. glabrata on pigment inducing medium leads to an increased resistance to hydrogen peroxide, an effect which was not observed with a mutant defective in pigmentation. Furthermore, pigmented yeast cells had a higher survival rate when exposed to human neutrophils and caused increased damage in a monolayer model of human epithelia, indicating a possible role of pigmentation during interactions with host cells.

A unique DNA found in post-mitochondrial fraction from Ehrlich ascites tumor cells

International Nuclear Information System (INIS)

Guimaraes, R.C.; Bloch, D.P.

1982-01-01

A DNA found in post-mitochondrial fractions from Ehrlich ascites cells, comprising 0.2% of the total cellular DNA, is partially characterized. It appears in cytoplasmic homogenates as a 14.6 S molecule, and is eluted from hydroxyapatite with 0.24 M sodium phosphate buffer. Its Cs 2 SO 4 buoyant density is lower than Erlich ascites tumor nuclear DNA and it has low dG+dC content, as determined by chromatography of hydrolysates of 32 P-labelled DNA. It is enriched in sequences which reassociate rapidly in the presence of excess nuclear DNA. It can be used as promoter for DNA synthesis by an endogenous DNA-dependent DNA polymerase found in association with the post-mitochondrial preparations. It is found to be associated with newly incorporated radioactivity following incubation in vitro with labelled UTP. Its localization in situ has not yet been attempled. It is thought to represent viral A-type particle associated, or plasma membrane associated DNA. (author) [pt

Hyperbolastic modeling of tumor growth with a combined treatment of iodoacetate and dimethylsulphoxide

International Nuclear Information System (INIS)

Eby, Wayne M; Tabatabai, Mohammad A; Bursac, Zoran

2010-01-01

An understanding of growth dynamics of tumors is important in understanding progression of cancer and designing appropriate treatment strategies. We perform a comparative study of the hyperbolastic growth models with the Weibull and Gompertz models, which are prevalently used in the field of tumor growth. The hyperbolastic growth models H1, H2, and H3 are applied to growth of solid Ehrlich carcinoma under several different treatments. These are compared with results from Gompertz and Weibull models for the combined treatment. The growth dynamics of the solid Ehrlich carcinoma with the combined treatment are studied using models H1, H2, and H3, and the models are highly accurate in representing the growth. The growth dynamics are also compared with the untreated tumor, the tumor treated with only iodoacetate, and the tumor treated with only dimethylsulfoxide, and the combined treatment. The hyperbolastic models prove to be effective in representing and analyzing the growth dynamics of the solid Ehrlich carcinoma. These models are more precise than Gompertz and Weibull and show less error for this data set. The precision of H3 allows for its use in a comparative analysis of tumor growth rates between the various treatments

Isolation of nucleoli from Ehrlich ascites tumor cells and dynamics of nascent RNA within isolated nucleoli.

Science.gov (United States)

Thiry, Marc; Ploton, Dominique

2008-01-01

Here we describe a new, rapid method for isolating nucleoli from Ehrlich tumor cells that preserves their morphological integrity and high transcriptional activity. Until now, methods for isolation of nucleoli were generally assumed to empty one of their three main compartments, the fibrillar center, of its contents. This new method consists of sonicating cells in an isotonic medium containing MgSO(4), spermidine, and spermine, followed by separation of nucleoli through a Percoll density gradient. Using the nonisotopic approach of labelling with BrUTP, we have further investigated the dynamics of nascent ribosomal RNAs (rRNAs) within morphologically intact isolated nucleoli at the electron microscope level. We show that ribosomal transcripts are elongated in the cortex of the fibrillar center and then enter the surrounding dense fibrillar component.

Anti-tumor therapy with macroencapsulated endostatin producer cells

Directory of Open Access Journals (Sweden)

Balduino Keli N

2010-03-01

Full Text Available Abstract Background Theracyte is a polytetrafluoroethylene membrane macroencapsulation system designed to induce neovascularization at the tissue interface, protecting the cells from host's immune rejection, thereby circumventing the problem of limited half-life and variation in circulating levels. Endostatin is a potent inhibitor of angiogenesis and tumor growth. Continuous delivery of endostatin improves the efficacy and potency of the antitumoral therapy. The purpose of this study was to determine whether recombinant fibroblasts expressing endostatin encapsulated in Theracyte immunoisolation devices can be used for delivery of this therapeutic protein for treatment of mice bearing B16F10 melanoma and Ehrlich tumors. Results Mice were inoculated subcutaneously with melanoma (B16F10 cells or Ehrlich tumor cells at the foot pads. Treatment began when tumor thickness had reached 0.5 mm, by subcutaneous implantation of 107 recombinant encapsulated or non-encapsulated endostatin producer cells. Similar melanoma growth inhibition was obtained for mice treated with encapsulated or non-encapsulated endostatin-expressing cells. The treatment of mice bearing melanoma tumor with encapsulated endostatin-expressing cells was decreased by 50.0%, whereas a decrease of 56.7% in tumor thickness was obtained for mice treated with non-encapsulated cells. Treatment of Ehrlich tumor-bearing mice with non-encapsulated endostatin-expressing cells reduced tumor thickness by 52.4%, whereas lower tumor growth inhibition was obtained for mice treated with encapsulated endostatin-expressing cells: 24.2%. Encapsulated endostatin-secreting fibroblasts failed to survive until the end of the treatment. However, endostatin release from the devices to the surrounding tissues was confirmed by immunostaining. Decrease in vascular structures, functional vessels and extension of the vascular area were observed in melanoma microenvironments. Conclusions This study indicates that

Anti-tumor therapy with macroencapsulated endostatin producer cells.

Science.gov (United States)

Rodrigues, Danielle B; Chammas, Roger; Malavasi, Natália V; da Costa, Patrícia L N; Chura-Chambi, Rosa M; Balduino, Keli N; Morganti, Ligia

2010-03-02

Theracyte is a polytetrafluoroethylene membrane macroencapsulation system designed to induce neovascularization at the tissue interface, protecting the cells from host's immune rejection, thereby circumventing the problem of limited half-life and variation in circulating levels. Endostatin is a potent inhibitor of angiogenesis and tumor growth. Continuous delivery of endostatin improves the efficacy and potency of the antitumoral therapy. The purpose of this study was to determine whether recombinant fibroblasts expressing endostatin encapsulated in Theracyte immunoisolation devices can be used for delivery of this therapeutic protein for treatment of mice bearing B16F10 melanoma and Ehrlich tumors. Mice were inoculated subcutaneously with melanoma (B16F10 cells) or Ehrlich tumor cells at the foot pads. Treatment began when tumor thickness had reached 0.5 mm, by subcutaneous implantation of 107 recombinant encapsulated or non-encapsulated endostatin producer cells. Similar melanoma growth inhibition was obtained for mice treated with encapsulated or non-encapsulated endostatin-expressing cells. The treatment of mice bearing melanoma tumor with encapsulated endostatin-expressing cells was decreased by 50.0%, whereas a decrease of 56.7% in tumor thickness was obtained for mice treated with non-encapsulated cells. Treatment of Ehrlich tumor-bearing mice with non-encapsulated endostatin-expressing cells reduced tumor thickness by 52.4%, whereas lower tumor growth inhibition was obtained for mice treated with encapsulated endostatin-expressing cells: 24.2%. Encapsulated endostatin-secreting fibroblasts failed to survive until the end of the treatment. However, endostatin release from the devices to the surrounding tissues was confirmed by immunostaining. Decrease in vascular structures, functional vessels and extension of the vascular area were observed in melanoma microenvironments. This study indicates that immunoisolation devices containing endostatin

Analysis of grease contamination influence on the internal radial clearance of ball bearings by thermographic inspection

Directory of Open Access Journals (Sweden)

Mišković Žarko Z.

2016-01-01

Full Text Available One of the most important factors influencing ball bearings service life is its internal radial clearance. However, this parameter is also very complex because it depends on applied radial load and ball bearings dimensions, surface finish and manufacturing materials. Thermal condition of ball bearings also significantly affects internal radial clearance. Despite many researches performed in order to find out relevant facts about different aspects of ball bearings thermal behaviour, only few of them are dealing with the real working conditions, where high concentration of solid contaminant particles is present. That’s why the main goal of research presented in this paper was to establish statistically significant correlation between ball bearings temperatures, their working time and concentration of contaminant particles in their grease. Because of especially difficult working conditions, the typical conveyor idlers bearings were selected as representative test samples and appropriate solid particles from open pit coal mines were used as artificial contaminants. Applied experimental methodology included thermographic inspection, as well as usage of custom designed test rig for ball bearings service life testing. Finally, by obtained experimental data processing in advanced software, statistically significant mathematical correlation between mentioned bearings characteristics was determined and applied in commonly used internal radial clearance equation. That is the most important contribution of performed research - the new equation and methodology for ball bearings internal clearance determination which could be used for eventual improvement of existing bearings service life equations. [Projekat Ministarstva nauke Republike Srbije, br. TR35029 i br. TR14033

Protective effect of pantothenic acid and related compounds against permeabilization of Ehrlich ascites tumour cells by digitonin

Energy Technology Data Exchange (ETDEWEB)

Slyshenkov, Vyacheslav S.; Rakowska, Mariola; Wojtczak, Lech [Polska Akademia Nauk, Warsaw (Poland). Inst. Biologii Doswiadczalnej

1996-12-31

Preincubation of Ehrlich ascites tumour cells with millimolar concentrations of pantothenic acid, pantothenol or panthethine, but not with homopantothenic acid, at 22 C or 32 C, but not at 0 C, makes the plasma membrane more resistant to the damaging effect of submillimolar concentrations of digitonin. It is proposed that this increased resistance is due to the increased rate of cholesterol biosynthesis. In fact, incorporation of [{sup 14}C]acetate into cholesterol is by 45% increased in the cells preincubated with pantothenic acid; this probably reflects elevation of the content of CoA in such cells [Slyshenkov, V.S., Rakowska, M., Moiseenok, A.G and Wojtczak, L. (1995) Free Radical Biol. Med. 19, 767-772]. (author). 9 refs, 2 figs, 1 tab.

Effect of infrared and X-ray radiation on thymus cells and the rate of growth of Ehrlich carcinoma.

Science.gov (United States)

Dyukina, A R; Zaichkina, S I; Rozanova, O M; Aptikaeva, G F; Romanchenko, S P; Sorokina, S S

2012-09-01

We studied the effect of infrared light with a wavelength of 850 nm and modulated frequency of 101 Hz and X-ray radiation on the induction of cross-adaptive and radiation responses in the thymus and on the rate of tumor growth in mice in vivo. Preliminary exposure to infrared and X-ray radiation was shown to result in recovery in thymus weight after irradiation in a dose of 1.5 Gy and also inhibited the growth rate of Ehrlich carcinoma. These data attest to common mechanisms of the adaptive response induced by infrared and X-ray radiation in mice. Infrared light can be used as an adaptogen to adapt the animals to adverse factors.

Inhibition by derivatives of diguanidines of cell proliferation in Ehrlich ascites cells grown in cultures.

Science.gov (United States)

Alhonen-Hongisto, L; Pösö, H; Jänne, J

1980-01-01

The anti-proliferative effects of 1,1'-[(methylethanediylidene)dinitrilo]diguanidine [methylglyoxal bis(guanylhydrazone)] and 1,1'-[(metHYLETHANEDIYLIDENE)dinitrilo]bis-(3-aminoguaNIDINE) HAVE BEEN STUDIED IN Ehrlich ascites carcinoma cells grown in suspension cultures. Both compounds are potent inhibitors of S-adenosyl-L-methionine decarboxylase from the tumour cells. In the presence of putrescine (but not in its absence), the inhibition produced by 1,1'-[methylethanediylidene)dinitrilo]bis-(3-aminoguanadine) was apparently irreversible, as judged by persistent depression of the enzyme activity even after extensive dialysis. The two compounds produced similar increases in adenosylmethionine decarboxylase activity, which resulted from a striking stabilization of the enzyme in cells grown in the presence of the drugs. The inhibitory effect of the two diguanidine derivatives on the synthesis of DNA and protein became evident after an exposure of 4--8 h. At that time, the only change seen in tumour polyamines in cells grown in the presence of the inhibitors was an increase in cellular putrescine. To find out whether the compounds initially interfered with the energy production of the tumour cells, the cultures were grown in the presence of uniformly labelled glucose, and the formation of lactate, as well as the oxidation of the sugar into CO2, were measured. The activation of glycolysis upon dilution of the tumour cells with fresh medium and the subsequent formation of labelled CO2 were siliar in control cells and in cells exposed to methylglyoxal bis(buanylhydrazone), 1,1'-[(methylethanediylidene)dinitrilo]bis-(3-aminoguanidine) or diaminopropanol. Only a marginal decrease in the cellular content of ATP was found in cells exposed to the inhibitors for 24 h. The diguanidine-induced growth inhibition was fully reversed by low concentrations of exogenous polyamines. However, the possibility remained that the reversal by polyamines was due to a decrease of intracellular

Inactivation of Ehrlich ascites tumor cells by heavy ions

International Nuclear Information System (INIS)

Bertsche, U.; Iliakis, G.; Kraft, G.

1983-01-01

Exponentially growing and plateau-phase cultures of Ehrlich ascites tumor cells were irradiated with heavy ions (Z greater than or equal to 20) and assayed for loss of reproductive capacity either immediately or at delayed times after irradiation. The results indicated no modification of the exponential dose response due to conditions which usually favor the repair of potentially lethal damage at low ionization density. Postirradiation treatment of the cells with a DNA synthesis inhibitor known to act on PLD repair resulted in effects similar to those observed without this drug and confirmed the hypothesis that at such high values of ionization density only lethal, unmodifiable damage can be expressed. The inactivation cross-section values calculated from the slope of the measured survival curves showed no significant correlations with commonly used parameters of radiation quality. Instead, a functional dependence on the primary ion energy was indicated, being smaller by a factor of two at low energies (less than or equal to 2 MeV/amu) compared with values at energies above 4 MeV/amu, where agreement with the morphological nuclear cross section of the culture was found. This suggests that at higher specific ion energies energetic secondary electrons contribute to the induction of lethal damage, and that interaction of damaged sites between the primary track and the track ends of delta electrons may occur. The data are therefore also discussed in terms of the penumbra model which emphasizes the role of delta electrons in cell killing when radiations with very high ionization density are applied

Influence of neuraminidase and X-ray irradiation (2 Gy and 8 Gy) on microvilli and membrane invaginations of Ehrlich ascites tumor cells in monolayer culture

International Nuclear Information System (INIS)

Laudenbach, G.; Baganz, O.; Pfab, R.; Hess, F.; Schachtschabel, D.O.

1987-01-01

A monolayer culture (Eagle basal medium plus 10% of fetal calf serum) of Ehrlich ascites tumor cells was exposed to X-radiation with 2 Gy and 8 Gy and treated with Vibrio cholerae neuraminidase alone or combined with sublethal X-ray irradiation (2 Gy). Pictures of the Ehrlich ascites tumor cells taken with the electron microscope were investigated in order to find out any cell surface modifications due to membrane invaginations and microvilli. The results showed that the rate of microvilli as well as that of membrane invaginations became higher with the increasing X-ray dose (2 Gy; 8 Gy). Following to neuraminidase treatment there was a considerable augmentation of membran invaginations as compared to control cells, whereas the number of microvilli was slightly reduced. As it has been already described before, the influence of neuraminidase produced an increased endocytosis activity and a strengthening of the cytoskeleton. Combined treatment with neuraminidase and sublethal X-radiation (2 Gy) caused a higher rate of membrane invaginations than each method alone; the number of microvilli was slightly increased by combined treatment. The conclusion is drawn that these structure modifications are due to reparation processes induced by radiation on the one hand and to an enzymic action of neuraminidase on the cell surface on the other hand. (orig.) [de

Hyperosmotic stress strongly potentiates serum response factor (SRF)-dependent transcriptional activity in ehrlich lettré ascites cells through a mechanism involving p38 mitogen-activated protein kinase

DEFF Research Database (Denmark)

Gorbatenko, Andrej; Wiwel, Maria; Klingberg, Henrik

2011-01-01

Long-term osmotic stress results in altered gene transcription, however, with the exception of the TonE/TonEBP system, the underlying mechanisms are poorly understood. We previously showed that upon osmotic shrinkage of Ehrlich Lettré Ascites (ELA) fibroblasts, the MEK1-ERK1/2 pathway is transien......Long-term osmotic stress results in altered gene transcription, however, with the exception of the TonE/TonEBP system, the underlying mechanisms are poorly understood. We previously showed that upon osmotic shrinkage of Ehrlich Lettré Ascites (ELA) fibroblasts, the MEK1-ERK1/2 pathway......) and cAMP response element-binding protein (CREB) are differentially regulated in ELA cells. SRF Ser103 phosphorylation and SRF-dependent transcriptional activity were strongly augmented 5–30¿min and 24¿h, respectively, after hyperosmotic stress (50% increase in extracellular ionic strength), in a p38...... dephosphorylated within 5¿min of shrinkage. MSK1 phosphorylation recovered within 30¿min in a p38-MAPK-dependent manner. CREB was transiently dephosphorylated after shrinkage in a manner exacerbated by p38 MAPK inhibition or MSK1 knockdown, but unaffected by inhibition of RSK. In conclusion, in ELA cells...

Investigations of Slip Effect on the Performance of Micro Gas Bearings and Stability of Micro Rotor-Bearing Systems

Directory of Open Access Journals (Sweden)

Jieyu Chen

2007-08-01

Full Text Available Incorporating the velocity slip effect of the gas flow at the solid boundary, theperformance and dynamic response of a micro gas-bearing-rotor system are investigated inthis paper. For the characteristic length scale of the micro gas bearing, the gas flow in thebearing resides in the slip regime rather than in the continuum regime. The modifiedReynolds equations of different slip models are presented. Gas pressure distribution and loadcarrying capacity are obtained by solving the Reynolds equations with finite differentmethod (FDM. Comparing results from different models, it is found that the second orderslip model agrees reasonably well with the benchmarked solutions obtained from thelinearized Boltzmann equation. Therefore, dynamic coefficients derived from the secondorder slip model are employed to evaluate the linear dynamic stability and vibrationcharacteristics of the system. Compared with the continuum flow model, the slip effectreduces dynamic coefficients of the micro gas bearing, and the threshold speed for stableoperation is consequently raised. Also, dynamic analysis shows that the system responseschange with variation of the operating parameters including the eccentricity ratio, therotational speed, and the unbalance ratio.

Planetary Suit Hip Bearing Model for Predicting Design vs. Performance

Science.gov (United States)

Cowley, Matthew S.; Margerum, Sarah; Harvil, Lauren; Rajulu, Sudhakar

2011-01-01

Designing a planetary suit is very complex and often requires difficult trade-offs between performance, cost, mass, and system complexity. In order to verifying that new suit designs meet requirements, full prototypes must eventually be built and tested with human subjects. Using computer models early in the design phase of new hardware development can be advantageous, allowing virtual prototyping to take place. Having easily modifiable models of the suit hard sections may reduce the time it takes to make changes to the hardware designs and then to understand their impact on suit and human performance. A virtual design environment gives designers the ability to think outside the box and exhaust design possibilities before building and testing physical prototypes with human subjects. Reductions in prototyping and testing may eventually reduce development costs. This study is an attempt to develop computer models of the hard components of the suit with known physical characteristics, supplemented with human subject performance data. Objectives: The primary objective was to develop an articulating solid model of the Mark III hip bearings to be used for evaluating suit design performance of the hip joint. Methods: Solid models of a planetary prototype (Mark III) suit s hip bearings and brief section were reverse-engineered from the prototype. The performance of the models was then compared by evaluating the mobility performance differences between the nominal hardware configuration and hardware modifications. This was accomplished by gathering data from specific suited tasks. Subjects performed maximum flexion and abduction tasks while in a nominal suit bearing configuration and in three off-nominal configurations. Performance data for the hip were recorded using state-of-the-art motion capture technology. Results: The results demonstrate that solid models of planetary suit hard segments for use as a performance design tool is feasible. From a general trend perspective

On the action of radioprotective agents on the endogenous serotonin content and radiosensitivity of isolated Ehrlich ascites tumour and E. coli B. cells

International Nuclear Information System (INIS)

Goncharenko, E.N.; Gorskaya, T.G.; Gusareva, Eh.V.; Konstantinova, M.M.; Panyushkina, N.V.; AN SSSR, Moscow. Inst. Biologii Razvitiya)

1976-01-01

At a higher radioresistance level attained by incubation of isolated Ehrlich ascites tumour and E. coli B. cells with MEA or noradrenaline, the endogenous serotonin content of these cells was found to increase. The extent of radioresistance increase and the serotonin content of the cells were interrelated, i.e. washing the protector off cells decreased both the radioresistance and the content of endogenous serotonin. It is concluded that radioresistance of cells is connected with the content of biologically active substances (serotonin) that possess radioprotective action

Development and characteristics of a subline of Ehrlich ascites carcinoma cells persistently resistant to 5-fluoro-2'-deoxyuridine.

Science.gov (United States)

Jastreboff, M M; Zielińska, Z M

1983-01-01

A subline of Ehrlich ascites carcinoma (EAC) cells resistant to 5-fluoro-2'-deoxy-uridine (FdUrd) was developed by continuous exposure to progressively increasing concentrations of the drug (35-75 mg/kg per day) during 15 passages through mice. Since then, the EAC cells have been retransplanted more than 80 times through drug-untreated mice and continue to be resistant. After adaptation to growth in suspension culture the drug-adapted cells were 1000 times more resistant to FdUrd in comparison with parental ones, and remained near-tetraploid with doubling time longer than in parental line. The activity of thymidine kinase was deeply depressed (100-fold) whereas that of thymidylate synthetase several-fold increased in the resistant EAC cells, both grown in vivo and in vitro.

Bearing system

Science.gov (United States)

Kapich, Davorin D.

1987-01-01

A bearing system includes backup bearings for supporting a rotating shaft upon failure of primary bearings. In the preferred embodiment, the backup bearings are rolling element bearings having their rolling elements disposed out of contact with their associated respective inner races during normal functioning of the primary bearings. Displacement detection sensors are provided for detecting displacement of the shaft upon failure of the primary bearings. Upon detection of the failure of the primary bearings, the rolling elements and inner races of the backup bearings are brought into mutual contact by axial displacement of the shaft.

Author Details

African Journals Online (AJOL)

Ahmed, Hanaa H. Vol 10, No 1 (2001) - Articles POTENTIATION OF THE PROTECTIVE EFFECTS OF MELATONIN AND CELL PROTECT IN EHRLICH ASCITES CARINOMA BEARING MICE Abstract. ISSN: 1110-5593. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's ...

Author Details

African Journals Online (AJOL)

Mannaa, Fathia. Vol 10, No 1 (2001) - Articles POTENTIATION OF THE PROTECTIVE EFFECTS OF MELATONIN AND CELL PROTECT IN EHRLICH ASCITES CARINOMA BEARING MICE Abstract. ISSN: 1110-5593. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's ...

Modelling of epitaxial film growth with an Ehrlich-Schwoebel barrier dependent on the step height

International Nuclear Information System (INIS)

Leal, F F; Ferreira, S C; Ferreira, S O

2011-01-01

The formation of mounded surfaces in epitaxial growth is attributed to the presence of barriers against interlayer diffusion in the terrace edges, known as Ehrlich-Schwoebel (ES) barriers. We investigate a model for epitaxial growth using an ES barrier explicitly dependent on the step height. Our model has an intrinsic topological step barrier even in the absence of an explicit ES barrier. We show that mounded morphologies can be obtained even for a small barrier while a self-affine growth, consistent with the Villain-Lai-Das Sarma equation, is observed in the absence of an explicit step barrier. The mounded surfaces are described by a super-roughness dynamical scaling characterized by locally smooth (facetted) surfaces and a global roughness exponent α > 1. The thin film limit is featured by surfaces with self-assembled three-dimensional structures having an aspect ratio (height/width) that may increase or decrease with temperature depending on the strength of the step barrier. (fast track communication)

Inactivation of Ehrlich ascites tumor cells by heavy ions

International Nuclear Information System (INIS)

Bertsche, U.; Iliakis, G.; Kraft, G.

1983-01-01

Exponentially growing and plateau-phase cultures of Ehrlich ascites tumor cells were irradiated with heavy ions (Z greater than or equal to 20) and assayed for loss of reproductive capacity either immediately or at delayed times after irradiation. The results indicated no modification of the exponential dose response due to conditions which usually favor the repair of potentially lethal damage at low ionization density. Postirradiation treatment of the cells with beta-arabinofuranosyladenine, a DNA synthesis inhibitor known to act on PLD repair, resulted in effects similar to those observed without this drug and confirmed the hypothesis that at such high values of ionization density only lethal, unmodifiable damage can be expressed. The inactivation cross-section values calculated from the slope of the measured survival curves showed no significant correlations with commonly used parameters of radiation quality such as LET or z 2 /beta 2. Instead, a functional dependence on the primary ion energy was indicated, being smaller by a factor of two at low energies (less than or equal to 2 MeV/amu) compared with values at energies above 4 MeV/amu, where agreement with the morphological nuclear cross section of the culture was found. This suggests that at higher specific ion energies energetic secondary electrons contribute to the induction of lethal damage, and that interaction of damaged sites between the primary track and the track ends of delta electrons may occur. The data are therefore also discussed in terms of the ''penumbra model'' which emphasizes the role of delta electrons in cell killing when radiations with very high ionization density are applied

Membrane damage effect of therapeutic ultrasound on Ehrlich ascitic tumor cells.

Science.gov (United States)

Hao, Qiao; Liu, Quanhong; Wang, Xiaobing; Wang, Pan; Li, Tao; Tong, Wan Yan

2009-02-01

The biologic effects and the underlying mechanisms of Ehrlich ascitic tumor (EAT) cells induced by ultrasound were investigated in this study. Cells were subjected to ultrasonic irradiation with a frequency of 2.17 MHz and an intensity of 3 W/cm(2) for variable periods of time. Trypan blue exclusion was used to detect the integrity of cellular membrane; the membrane permeability was investigated by the incorporation of fluorescein isothiocyanate dextran during ultrasound exposure; and the cell membrane ultrastructure changes were observed under a scanning electron microscope. The potential mechanism was estimated from the generation of hydroxyl radicals, the lipid peroxidation levels, and intracellular reactive oxygen radicals production. The cell membrane damage effects induced by ultrasound increased with a prolonged exposure time; the fluorescent rates of the cells irradiated with ultrasound for 30 and 60 seconds were 11.46% and 18.50%, respectively; the amount of hydroxyl radicals in 30 (26.10 U/mL) and 60 seconds (28.47 U/mL) were significantly enhanced, compared with the control group (24.44 U/mL); then, the level of lipid peroxidation was also changed from 0.27 to 0.54 (30 seconds) and 1.21 nmol/mL (60 seconds). Shear forces and free radicals produced by acoustic cavitation may play important roles in these actions.

Solid radwaste processing and conditioning. The SGN experience

International Nuclear Information System (INIS)

Tucoulat, D.; Tchemitcheff, E.

1993-01-01

Solid wastes are generated in the operation of the installations in France. These solid wastes display different levels of radioactivity. Some of them arising from research centres or reprocessing plants even contain relatively significant quantities of alpha-bearing radionuclides. In order to produce an ultimate waste package that satisfies the requirements set by safety authorities and the organizations in charge of final waste disposal in the concerned countries, solid waste conditioning takes place in a number of successive steps

Sintered Cathodes for All-Solid-State Structural Lithium-Ion Batteries

Science.gov (United States)

Huddleston, William; Dynys, Frederick; Sehirlioglu, Alp

2017-01-01

All-solid-state structural lithium ion batteries serve as both structural load-bearing components and as electrical energy storage devices to achieve system level weight savings in aerospace and other transportation applications. This multifunctional design goal is critical for the realization of next generation hybrid or all-electric propulsion systems. Additionally, transitioning to solid state technology improves upon battery safety from previous volatile architectures. This research established baseline solid state processing conditions and performance benchmarks for intercalation-type layered oxide materials for multifunctional application. Under consideration were lithium cobalt oxide and lithium nickel manganese cobalt oxide. Pertinent characteristics such as electrical conductivity, strength, chemical stability, and microstructure were characterized for future application in all-solid-state structural battery cathodes. The study includes characterization by XRD, ICP, SEM, ring-on-ring mechanical testing, and electrical impedance spectroscopy to elucidate optimal processing parameters, material characteristics, and multifunctional performance benchmarks. These findings provide initial conditions for implementing existing cathode materials in load bearing applications.

Ultrasonic methods in solid state physics

CERN Document Server

Truell, John; Elbaum, Charles

1969-01-01

Ultrasonic Methods in Solid State Physics is devoted to studies of energy loss and velocity of ultrasonic waves which have a bearing on present-day problems in solid-state physics. The discussion is particularly concerned with the type of investigation that can be carried out in the megacycle range of frequencies from a few megacycles to kilomegacycles; it deals almost entirely with short-duration pulse methods rather than with standing-wave methods. The book opens with a chapter on a classical treatment of wave propagation in solids. This is followed by separate chapters on methods and techni

Antares alignment gimbal positioner linear bearing tests

International Nuclear Information System (INIS)

Day, R.D.; McKay, M.D.; Pierce, D.D.; Lujan, R.E.

1981-01-01

The data indicate that of the six configurations tested, the solid circular rails with either the wet or dry lubricant are superior to the other configurations. Therefore, these two will undergo additional tests. These tests will consist of (1) modifying the testing procedure to obtain a better estimation of the limits of precision; and (2) subjecting the bearings to moments more closely approximating the actual conditions they will undergo on the AGP

Expression of P-glycoprotein and multidrug resistance associated protein in Ehrlich ascites tumor cells after fractionated irradiation

DEFF Research Database (Denmark)

Nielsen, D; Maare, C; Eriksen, J

2001-01-01

PURPOSE: To characterize irradiated murine tumor cells with respect to drug resistance, drug kinetics, and ATPase activity, and to evaluate the possible role of P-glycoprotein (PGP) and murine multidrug resistance associated protein (Mrp1) in the drug-resistant phenotype of these cells. METHODS...... AND MATERIALS: Sensitive Ehrlich ascites tumor cells (EHR2) were in vitro exposed to fractionated irradiation (60 Gy). Western blot analysis was performed for determination of PGP and Mrp1, reverse transcriptase-polymerase chain reaction (RT-PCR) for determination of mdr1a + b mRNA, and semiquantitative RT......-PCR for Mrp1 mRNA. The clonogenic assay was applied to investigate sensitivity, whereas the steady-state drug accumulation of daunorubicin (DNR), 3H-vincristine (VCR), and 3H-etoposide (VP16) was measured by spectrofluorometry and scintillation counting, respectively. For determining of ATPase activity...

Effect of misonidazole (Ro-07-0582) on the incidence of micronuclei in irradiated Ehrlich tumour ascites cells

Energy Technology Data Exchange (ETDEWEB)

Olinici, C D; Mustea, I [Institute of Oncology, Cluj (Romania)

1978-12-01

Misonidazole (1-(2-nitro-1-imidazole)-3-methoxy-2-propanol) was injected intraperitoneally into mice on the fifth day of development of Ehrlich ascites tumours. The animals were then /sup 60/Co ..gamma..-irradiated (100 to 400 R) and killed at 24 to 72 hours post-irradiation. Ascites tumour cells from the mice were stained by the Feulgen reaction and the incidence of micronuclei determined. Pretreatment with misonidazole induced an increase in the incidence of micronuclei in the irradiated tumour cells. This increase was most conspicuous at higher radiation doses and at 48 hours post-irradiation. The results suggest the possibility of using the micronucleus assay for the screening of substances with radio-sensitizing potential. The method would be especially suitable for the study of tumours irradiated in vivo with high doses of radiation, since cytogenetic methods present difficulties under these conditions.

Journal bearing

Science.gov (United States)

Menke, John R.; Boeker, Gilbert F.

1976-05-11

1. An improved journal bearing comprising in combination a non-rotatable cylindrical bearing member having a first bearing surface, a rotatable cylindrical bearing member having a confronting second bearing surface having a plurality of bearing elements, a source of lubricant adjacent said bearing elements for supplying lubricant thereto, each bearing element consisting of a pair of elongated relatively shallowly depressed surfaces lying in a cylindrical surface co-axial with the non-depressed surface and diverging from one another in the direction of rotation and obliquely arranged with respect to the axis of rotation of said rotatable member to cause a flow of lubricant longitudinally along said depressed surfaces from their distal ends toward their proximal ends as said bearing members are rotated relative to one another, each depressed surface subtending a radial angle of less than 360.degree., and means for rotating said rotatable bearing member to cause the lubricant to flow across and along said depressed surfaces, the flow of lubricant being impeded by the non-depressed portions of said second bearing surface to cause an increase in the lubricant pressure.

Study of blood plasma optical properties in mice grafted with Ehrlich carcinoma in the frequency range 0.1-1.0 THz

Science.gov (United States)

Smolyanskaya, O. A.; Kravtsenyuk, O. V.; Panchenko, A. V.; Odlyanitskiy, E. L.; Guillet, J. P.; Cherkasova, O. P.; Khodzitsky, M. K.

2017-12-01

In the course of in vitro studies of blood of laboratory animals with progressing Ehrlich carcinoma, we have revealed the change of the blood plasma optical properties in the THz range, which can be used for developing the express diagnostics of the presence of oncological diseases. An applied software package is elaborated that allows the phantoms of biological samples having a complex structure to be numerically simulated and the parameters of the electromagnetic wave reflected from these samples in the THz frequency range to be calculated. Presented at the Fundamentals of Laser Micro- and Nanotechnologies (FLAMN-16) International Symposium (Pushkin, Leningrad oblast, 27 June to 1 July 2016).

Camshaft bearing arrangement

Energy Technology Data Exchange (ETDEWEB)

Aoi, K.; Ozawa, T.

1986-06-10

A bearing arrangement is described for the camshaft of an internal combustion engine or the like which camshaft is formed along its length in axial order with a first bearing surface, a first cam lobe, a second bearing surface, a second cam lobe, a third bearing surface, a third cam lobe and a fourth bearing surface, the improvement comprising first bearing means extending around substantially the full circumference of the first bearing surface and journaling the first bearing surface, second bearing means extending around substantially less than the circumference of the second bearing surface and journaling the second bearing surface, third bearing means extending around substantially less than the circumference of the third bearing surface and journaling the third bearing surface, and fourth bearing means extending around substantially the full circumference of the fourth bearing surface and journaling the first bearing surface.

Ehrlich and sarcoma 180 tumour characterisation and early detection by 1H NMR-based metabonomics of mice serum

International Nuclear Information System (INIS)

Grandizoli, Caroline W.P. da S.; Simonelli, Fabio; Nagata, Noemi; Barison, Andersson; Carrenho, Luise Z.B.; Francisco, Thais M.G. de; Campos, Francinete R.; Santana Filho, Arquimedes P. de; Sassaki, Guilherme L.; Kreuger, Maria R.O.

2014-01-01

The success of cancer treatment is directly related to early detection before symptoms emerge, although nowadays few cancers can be detected early. In this sense, 1 H nuclear magnetic resonance ( 1 H NMR)-based metabonomics was used to identify metabolic changes in biofluid as a consequence of tumours growing in mice. Through partial least squares discriminant analysis (PLS-DA) analysis of 1 H NMR spectra from serum samples it was possible to diagnose Ehrlich ascites and Sarcoma 180 tumours five and ten days after cell inoculation, respectively. Lipids, lipoproteins and lactate were the main biomarkers at onset as well as in the progress of carcinogenic process. Thus, NMR-based metabonomics can be a valuable tool to study the effects of tumour establishment on the chemical composition of biofluids. (author)

Graphene quantum dots as the electrolyte for solid state supercapacitors

Science.gov (United States)

Zhang, Su; Li, Yutong; Song, Huaihe; Chen, Xiaohong; Zhou, Jisheng; Hong, Song; Huang, Minglu

2016-01-01

We propose that graphene quantum dots (GQDs) with a sufficient number of acidic oxygen-bearing functional groups such as -COOH and -OH can serve as solution- and solid- type electrolytes for supercapacitors. Moreover, we found that the ionic conductivity and ion-donating ability of the GQDs could be markedly improved by simply neutralizing their acidic functional groups by using KOH. These neutralized GQDs as the solution- or solid-type electrolytes greatly enhanced the capacitive performance and rate capability of the supercapacitors. The reason for the enhancement can be ascribed to the fully ionization of the weak acidic oxygen-bearing functional groups after neutralization. PMID:26763275

Investigation of Combined Action of Food Supplement's and Ionizing Radiation on the Cytogenetic Damage Induction and Ehrlich Ascite Carcinoma Growth on Mice in Vivo

Science.gov (United States)

Sorokina, Svetlana; Zaichkina, Svetlana; Dyukina, Alsu; Rozanova, Olga; Balakin, Vladimir; Peleshko, Vladimir; Romanchenko, Sergey; Smirnova, Helena; Aptikaeva, Gella; Shemyakov, Alexander

. The relation of the amount of the food supplement to the quantity of standard food was selected experimentally. In order to determine the level of radiosensitivity all groups of mice were subjected to X-radiation with the dose of 1,5 Gy and for induction of RAR the animals were irradiated according to the standard scheme (10 cGy+1,5 Gy). The influence of food supplement on the growth of solid tumor was estimated by measuring the size of the tumor at different times after the inoculation of ascitic cells s.c. into the femur. The percent of polychromatic erythrocytes (PCE) with micronucleus (MN) in marrow served as definition criteria of cytogenetic level of damage. The results of the study indicate that: 1) Due to influence of high-LET radiation with the dose of 11,6 Gy, mice who had dietary supplement demonstrated reduction of PCE with MN to the level of natural background radiation comparing with mice who had only standard food; 2) Diet containing soybeam, buckwheat or greens unlike cod-liver oil reduces the sensitivity of mice to X-radiation with the dose of 1,5 Gy and causes significant slowdown in growth of Ehrlich carcinoma; 3) The combined effect of high-LET radiation and the food supplements (except for cod-liver oil) reduces the sensitivity of mice to irradiation with the dose of 1,5 Gy, which demonstrate ability of RAR induction unlike the mice only irradiated with high-LET radiation and causes the slowdown in growth speed of Ehrlich carcinoma in contrast to the mice only irradiated with high-LET with the dose of 11,6 Gy; 4) The combined effect of high-LET radiation and the food supplements (except for cod-liver oil) does not influence the quantity of RAR according to the standard scheme (10 cGy+1,5 Gy).

Properties of thymidylate synthetase from Ehrlich ascites carcinoma cells. Effect of Mg2/ and MgATP2-.

Science.gov (United States)

Jastreboff, M; Kedzierska, B; Rode, W

1982-01-15

Ehrlich ascites carcinoma thymidylate synthetase was purified to electrophoretic homogeneity by affinity chromatography on 10-formyl-5,8-dideazofolate-ethyl-Sepharose. Electrophoretic analysis of the formation of the enzyme-5-fluorodeoxyuridylate-5,10-methylenetetrahydrofolate complexes showed the presence of two binding sites for 5-fluorodeoxyuridylate on the enzyme molecule. Molecular weight of the native enzyme was found to be 78,5000, whereas that of its monomer was 38, 500. The apparent Michaelis constants for dUMP and (+/-)-L-5,10-methylenetetrahydrofolate were 1.3 +/- 0.4 and 32.2 +/- 0.7 micrometers respectively. Phosphate acted as a weak inhibitor, competitive toward dUMP. The enzyme reaction exhibited a temperature-dependent change of activation energy, reflected in the binding affinity of dUMP, with a transitional temperature of 35.8 degrees. Both Mg2+ and MgATP2- were strong activators of the enzyme, MgATP2- being more effective.

Effect of paclitaxel, epirubicin and tamoxifen on labelling index in cultured ehrlich ascites tumor cells

International Nuclear Information System (INIS)

Arican, G. Oe.; Oezalpan, A.

2001-01-01

The effect of Paclitaxel (PAC), Epirubicin (EPR) and Tamoxifen (TAM) on ''3H-thymidine labelling index (''3H-TdR LI) of Ehrlich ascites tumor cells (EAT) was investigated in cultured. In the present study, an estrogen receptor positive ER(+) hyper diploid cell lines were studied. We used optimum doses of PAC, EPR and TAM (12 mg/ml, 12 mg/ml and 2 mg/ml, respectively). Cells were treated with these doses for 0, 4, 8, 16 and 32 hours. At the end of these periods, both control and treated cells were labelled for 5 mCi/ml 3H-thymidine for 30 minutes. The results showed that inhibition of DNA synthesis in cultured EAT cells were increased in the combined treatment of two drugs when compared to the treatment of a single drug (p<0.01). In the treatment of three drugs, however, this effect reached a maximum (p<0.001). As a result, PAC+EPR+TAM treatment's had a maximum synergistic effect at 4 hours treatment

Genetic constraints in the induction of the immune response to Ehrlich ascites tumor in mice

International Nuclear Information System (INIS)

Marusic, M.; Perkins, E.H.

1981-01-01

A single injection of irradiated Ehrlich ascites tumor (EAT) cells induces immunity in normal mice but fails to do so in T-cell-deficient-thymectomized, lethally irradiated, bone marrow-reconstituted (TIR) mice. TIR mice injected with normal syngeneic T cells develop an immune response to EAT when injected with irradiated EAT cells and reject a subsequent tumor cell challenge. In the present studies allogeneic T cells were unable to protect against EAT in TIR recipients even if harvested from donors tolerant to the recipient's transplantation antigens and injected into the TIR mice tolerant to the transplantation antigens of the injected T cells. Tolerance was produced by establishing long-term radiation chimeras of the P → F 1 type. Semiallogeneic T cells also failed to afford protection against EAT in TIR recipients. Whereas tolerance to other parental-strain transplantation antigens did not reverse the inability of parental T cells (cells from P → F 1 chimeric donors) to protect against EAT in F 1 TIR mice, it did enable F 1 T cells to afford protection in P → F 1 TIR mice

RNA and protein synthesis of irradiated Ehrlich ascites tumour cells. Pt. 1

International Nuclear Information System (INIS)

Skog, S.; Tribukait, B.; Sundius, G.

1985-01-01

The effects of roentgen irradiation on the incorporation of 3 H-uridine and 14 C-leucine into RNA and protein and the RNA and protein contents of in vivo growing Ehrlich ascites tumour cells were studied. The results were related to changes in the composition of cells in cell cycle and compared with the synthesis of RNA and protein in cell material from various parts of the cell cycle obtained by means of elutriator centrifuging. The incorporation expressed by the ratio between acid insoluble/acid soluble activity was unchanged for RNA during the observation period up to 24 hours after a dose of 5.0 Gy. The ratio for protein was markedly decreased between 4 and 24 hours. This decrease was partly due to a decrease of the pool size of leucine as studied by changing the amounts of 14 C leucine used. From these studies, the existence of at least two pools, an expandable and a non-expandable fixed pool can be concluded. There were no differences in the decrease of protein-synthesis between cells from the various parts of the cell cycle. The RNA and protein contents of the irradiated cells from various parts of the cell cycle corresponded to those of non-irradiated cells except for G 1 /early S-phase cells at 15 and 24 hours after irradiation. Possible reasons for this discrepancy are discussed. (orig.)

Ehrlich and sarcoma 180 tumour characterisation and early detection by {sup 1}H NMR-based metabonomics of mice serum

Energy Technology Data Exchange (ETDEWEB)

Grandizoli, Caroline W.P. da S.; Simonelli, Fabio; Nagata, Noemi; Barison, Andersson [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Quimica; Carrenho, Luise Z.B.; Francisco, Thais M.G. de; Campos, Francinete R. [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Farmacia; Santana Filho, Arquimedes P. de; Sassaki, Guilherme L. [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Bioquimica; Kreuger, Maria R.O. [Universidade do Vale do Itajai (UNIVALI), (Brazil). Centro de Ciencias da Saude

2014-05-15

The success of cancer treatment is directly related to early detection before symptoms emerge, although nowadays few cancers can be detected early. In this sense, {sup 1}H nuclear magnetic resonance ({sup 1}H NMR)-based metabonomics was used to identify metabolic changes in biofluid as a consequence of tumours growing in mice. Through partial least squares discriminant analysis (PLS-DA) analysis of {sup 1}H NMR spectra from serum samples it was possible to diagnose Ehrlich ascites and Sarcoma 180 tumours five and ten days after cell inoculation, respectively. Lipids, lipoproteins and lactate were the main biomarkers at onset as well as in the progress of carcinogenic process. Thus, NMR-based metabonomics can be a valuable tool to study the effects of tumour establishment on the chemical composition of biofluids. (author)

Grizzly bear

Science.gov (United States)

Schwartz, C.C.; Miller, S.D.; Haroldson, M.A.; Feldhamer, G.; Thompson, B.; Chapman, J.

2003-01-01

The grizzly bear inspires fear, awe, and respect in humans to a degree unmatched by any other North American wild mammal. Like other bear species, it can inflict serious injury and death on humans and sometimes does. Unlike the polar bear (Ursus maritimus) of the sparsely inhabited northern arctic, however, grizzly bears still live in areas visited by crowds of people, where presence of the grizzly remains physically real and emotionally dominant. A hike in the wilderness that includes grizzly bears is different from a stroll in a forest from which grizzly bears have been purged; nighttime conversations around the campfire and dreams in the tent reflect the presence of the great bear. Contributing to the aura of the grizzly bear is the mixture of myth and reality about its ferocity. unpredictable disposition, large size, strength, huge canines, long claws, keen senses, swiftness, and playfulness. They share characteristics with humans such as generalist life history strategies. extended periods of maternal care, and omnivorous diets. These factors capture the human imagination in ways distinct from other North American mammals. Precontact Native American legends reflected the same fascination with the grizzly bear as modern stories and legends (Rockwell 1991).

Steady state characteristics of a tilting pad journal bearing with controllable lubrication: Comparison between theoretical and experimental results

DEFF Research Database (Denmark)

Cerda Varela, Alejandro Javier; Nielsen, Bo Bjerregaard; Santos, Ilmar

2013-01-01

direction. The modification of the injection pressure enables to modify the bearing static and dynamic properties according to the operational needs. The results presented are obtained using a theoretical model, which considers all the effects that determine the bearing behavior (controllable......This paper is aimed at presenting results regarding the static and thermal behavior of a tilting-pad journal bearing operating under controllable regime. The bearing is rendered controllable by injecting high pressure oil into the clearance using holes drilled across the bearing pads in the radial...... elastothermohydrodynamic lubrication regime), as well as using a test rig designed and built to this effect. The comparison between experimental and theoretical results provides solid ground to determine the accuracy of the available model for the the prediction of the steady-state behavior of the tilting-pad bearing...

Xenoestrogenic and dioxin-like activity in blood of East Greenland polar bears (Ursus maritimus)

DEFF Research Database (Denmark)

Erdmann, Simon Erik; Dietz, Rune; Sonne, Christian

2013-01-01

The aims of the project were to (i) extract the lipophilic persistent organic pollutants (POPs) from the blood of 99 East Greenland polar bears and assess the combined mixture effect on the estrogen receptor (ER) and the aryl hydrocarbon receptor (AhR) mediated transactivity; (ii) To evaluate...... whether the receptor transactivities were associated with selected POP markers, and (iii) compare the receptor transactivities in polar bears with earlier studies on Greenlandic Inuit. Lipophilic POPs were extracted using a combination of solid-phase extraction (SPE) and high performance liquid...... induced ER response. Positive correlations were found in subadult bears between XER and several POP biomarkers. XER and XERcomp correlated positively to each other. A total of 91% of the polar bear blood extracts elicited agonistic AhR transactivity. The AhR-TCDD equivalent (AhR-TEQ) median levels were...

Flavonoids from Annona dioica leaves and their effects in Ehrlich carcinoma cells, DNA-topoisomerase I and II

International Nuclear Information System (INIS)

Vega, Maria R.G.; Esteves-Souza, Andressa; Echevarria, Aurea; Vieira, Ivo J.C.; Mathias, Leda; Braz-Filho, Raimundo

2007-01-01

Chemical investigation of methanol extract leaves from Annona dioica (Annonaceae) resulted in the identification of flavonoids kaempferol (1), 3-O-[3'',6''-di-O-p-hydroxycinnamoyl]-β- galactopyranosyl-kaempferol (2), 6''-O-p-hydroxycinnamoyl-β-galactopyranosyl-kaempferol (3) and 3-O-β-galactopyranosyl-kaempferol (4). The structures were unequivocally characterized by 1 H and 13 C NMR spectroscopic analyses using 1D and 2D experiments. The cytotoxic effects of the flavonoids and flavonoid fraction (FF) were evaluated by MTT (3-(4,5-dimethylthiazole-2- yl)-2,5-diphenyltetrazolium bromide) assay against Ehrlich carcinoma cells. The results indicated that 1, 2, 3 and FF exhibit significant antiproliferative action when compared to quercetin. The inhibitory action on DNA-topoisomerase I and II of all the flavonoids was evaluated by relaxation assays on pBR322 plasmid DNA. The results indicated the inhibitory and non-selective effects of the flavonoids on DNA-topoisomerase I and II. (author)

Flavonoids from Annona dioica leaves and their effects in Ehrlich carcinoma cells, DNA-topoisomerase I and II

Energy Technology Data Exchange (ETDEWEB)

Vega, Maria R.G.; Esteves-Souza, Andressa; Echevarria, Aurea [Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropedica, RJ (Brazil). Dept. de Quimica]. E-mail: echevarr@ufrrj.br; Vieira, Ivo J.C.; Mathias, Leda; Braz-Filho, Raimundo [Universidade Estadual do Norte Fluminense (UENF), Campos dos Goytacases, RJ (Brazil). Lab. de Ciencias Quimicas

2007-07-01

Chemical investigation of methanol extract leaves from Annona dioica (Annonaceae) resulted in the identification of flavonoids kaempferol (1), 3-O-[3'',6''-di-O-p-hydroxycinnamoyl]-{beta}- galactopyranosyl-kaempferol (2), 6''-O-p-hydroxycinnamoyl-{beta}-galactopyranosyl-kaempferol (3) and 3-O-{beta}-galactopyranosyl-kaempferol (4). The structures were unequivocally characterized by {sup 1}H and {sup 13}C NMR spectroscopic analyses using 1D and 2D experiments. The cytotoxic effects of the flavonoids and flavonoid fraction (FF) were evaluated by MTT (3-(4,5-dimethylthiazole-2- yl)-2,5-diphenyltetrazolium bromide) assay against Ehrlich carcinoma cells. The results indicated that 1, 2, 3 and FF exhibit significant antiproliferative action when compared to quercetin. The inhibitory action on DNA-topoisomerase I and II of all the flavonoids was evaluated by relaxation assays on pBR322 plasmid DNA. The results indicated the inhibitory and non-selective effects of the flavonoids on DNA-topoisomerase I and II. (author)

77 FR 70423 - Black Bear Hydro Partners, LLC and Black Bear Development Holdings, LLC and Black Bear SO, LLC...

Science.gov (United States)

2012-11-26

... Bear Hydro Partners, LLC and Black Bear Development Holdings, LLC and Black Bear SO, LLC; Notice of..., 2012, Black Bear Hydro Partners, LLC, sole licensee (transferor) and Black Bear Development Holdings, LLC and Black Bear SO, LLC (transferees) filed an application for the partial the transfer of licenses...

Thermal conductivity of hydrate-bearing sediments

Science.gov (United States)

Cortes, Douglas D.; Martin, Ana I.; Yun, Tae Sup; Francisca, Franco M.; Santamarina, J. Carlos; Ruppel, Carolyn D.

2009-01-01

A thorough understanding of the thermal conductivity of hydrate-bearing sediments is necessary for evaluating phase transformation processes that would accompany energy production from gas hydrate deposits and for estimating regional heat flow based on the observed depth to the base of the gas hydrate stability zone. The coexistence of multiple phases (gas hydrate, liquid and gas pore fill, and solid sediment grains) and their complex spatial arrangement hinder the a priori prediction of the thermal conductivity of hydrate-bearing sediments. Previous studies have been unable to capture the full parameter space covered by variations in grain size, specific surface, degree of saturation, nature of pore filling material, and effective stress for hydrate-bearing samples. Here we report on systematic measurements of the thermal conductivity of air dry, water- and tetrohydrofuran (THF)-saturated, and THF hydrate–saturated sand and clay samples at vertical effective stress of 0.05 to 1 MPa (corresponding to depths as great as 100 m below seafloor). Results reveal that the bulk thermal conductivity of the samples in every case reflects a complex interplay among particle size, effective stress, porosity, and fluid-versus-hydrate filled pore spaces. The thermal conductivity of THF hydrate–bearing soils increases upon hydrate formation although the thermal conductivities of THF solution and THF hydrate are almost the same. Several mechanisms can contribute to this effect including cryogenic suction during hydrate crystal growth and the ensuing porosity reduction in the surrounding sediment, increased mean effective stress due to hydrate formation under zero lateral strain conditions, and decreased interface thermal impedance as grain-liquid interfaces are transformed into grain-hydrate interfaces.

Phylogeography of mitochondrial DNA variation in brown bears and polar bears.

Science.gov (United States)

Shields, G F; Adams, D; Garner, G; Labelle, M; Pietsch, J; Ramsay, M; Schwartz, C; Titus, K; Williamson, S

2000-05-01

We analyzed 286 nucleotides of the middle portion of the mitochondrial cytochrome b gene of 61 brown bears from three locations in Alaska and 55 polar bears from Arctic Canada and Arctic Siberia to test our earlier observations of paraphyly between polar bears and brown bears as well as to test the extreme uniqueness of mitochondrial DNA types of brown bears on Admiralty, Baranof, and Chichagof (ABC) islands of southeastern Alaska. We also investigated the phylogeography of brown bears of Alaska's Kenai Peninsula in relation to other Alaskan brown bears because the former are being threatened by increased human development. We predicted that: (1) mtDNA paraphyly between brown bears and polar bears would be upheld, (2) the mtDNA uniqueness of brown bears of the ABC islands would be upheld, and (3) brown bears of the Kenai Peninsula would belong to either clade II or clade III of brown bears of our earlier studies of mtDNA. All of our predictions were upheld through the analysis of these additional samples. Copyright 2000 Academic Press.

Phylogeography of mitochondrial DNA variation in brown bears and polar bears

Science.gov (United States)

Shields, Gerald F.; Adams, Deborah; Garner, Gerald W.; Labelle, Martine; Pietsch, Jacy; Ramsay, Malcolm; Schwartz, Charles; Titus, Kimberly; Williamson, Scott

2000-01-01

We analyzed 286 nucleotides of the middle portion of the mitochondrial cytochrome b gene of 61 brown bears from three locations in Alaska and 55 polar bears from Arctic Canada and Arctic Siberia to test our earlier observations of paraphyly between polar bears and brown bears as well as to test the extreme uniqueness of mitochondrial DNA types of brown bears on Admiralty, Baranof, and Chichagof (ABC) islands of southeastern Alaska. We also investigated the phylogeography of brown bears of Alaska's Kenai Peninsula in relation to other Alaskan brown bears because the former are being threatened by increased human development. We predicted that: (1) mtDNA paraphyly between brown bears and polar bears would be upheld, (2) the mtDNA uniqueness of brown bears of the ABC islands would be upheld, and (3) brown bears of the Kenai Peninsula would belong to either clade II or clade III of brown bears of our earlier studies of mtDNA. All of our predictions were upheld through the analysis of these additional samples.

Targeting doxorubicin encapsulated in stealth liposomes to solid tumors by non thermal diode laser.

Science.gov (United States)

Ghannam, Magdy M; El Gebaly, Reem; Fadel, Maha

2016-04-05

The use of liposomes as drug delivery systems is the most promising technique for targeting drug especially for anticancer therapy. In this study sterically stabilized liposomes was prepared from DPPC/Cholesterol/PEG-PE encapsulated doxorubicin. The effect of lyophilization on liposomal stability and hence expiration date were studied. Moreover, the effect of diode laser on the drug released from liposomesin vitro and in vivo in mice carrying implanted solid tumor were also studied. The results indicated that lyophilization of the prepared liposomes encapsulating doxorubicin led to marked stability when stored at 5 °C and it is possible to use the re-hydrated lyophilized liposomes within 12 days post reconstitution. Moreover, the use of low energy diode laser for targeting anticancer drug to the tumor cells is a promising method in cancer therapy. We can conclude that lyophilization of the liposomes encapsulating doxorubicin lead to marked stability for the liposomes when stored at 5 °C. Moreover, the use of low energy diode laser for targeting anticancer drug to the tumor cells through the use of photosensitive sterically stabilized liposomes loaded with doxorubicin is a promising method. It proved to be applicable and successful for treatment of Ehrlich solid tumors implanted in mice and eliminated toxic side effects of doxorubicin.

Cell cycle-dependent activity of the volume- and Ca2+-activated anion currents in Ehrlich lettre ascites cells

DEFF Research Database (Denmark)

Klausen, Thomas Kjaer; Bergdahl, Andreas; Christophersen, Palle

2007-01-01

Recent evidence implicates the volume-regulated anion current (VRAC) and other anion currents in control or modulation of cell cycle progression; however, the precise involvement of anion channels in this process is unclear. Here, Cl- currents in Ehrlich Lettre Ascites (ELA) cells were monitored...... during cell cycle progression, under three conditions: (i) after osmotic swelling (i.e., VRAC), (ii) after an increase in the free intracellular Ca2+ concentration (i.e., the Ca2+-activated Cl- current, CaCC), and (iii) under steady-state isotonic conditions. The maximal swelling-activated VRAC current......+ in the pipette), was unaltered from G0 to G1, but decreased in early S phase. A novel high-affinity anion channel inhibitor, the acidic di-aryl-urea NS3728, which inhibited both VRAC and CaCC, attenuated ELA cell growth, suggesting a possible mechanistic link between cell cycle progression and cell cycle...

Comparisons of labeling efficiency, biological activity and biodistribution among 125I, 67Ga-DTPA- and 67Ga-DFO-lectins

International Nuclear Information System (INIS)

Kojima, Shuji; Jay, M.

1987-01-01

The labeling efficiency, biological activity and biodistribution of 125 I labeled and 67 Ga chelating agent conjugated lectins were investigated. Pisum sativum agglutinin (PSA) and Lens culinaris agglutinin (LCH) were efficiently labeled with 67 Ga using bifunctional chelating agents such as diethylenetriaminepentaacetic acid (DTPA) and deferoxamine (DFO), whereas labeling with 125 I was significantly less efficient. The agglutinating activity of these lectins towards Ehrlich ascites tumor (EAT) cells was retained on conjugation with DFO, but not with DTPA. The in vitro binding ratio of 67 Ga-DFO-lectins for EAT cells was almost the same as that of 125 I-lectins. However, the value was significantly decreased in the case of 67 Ga-DTPA-lectins. In the biodistribution study of radiolabeled lectins in Ehrlich solid tumor (EST) bearing mice, the accumulation of radioactivity in tumor tissue was very much less with 67 Ga-DTPA-lectins than with 125 I-lectins. However, the concentration was significantly elevated in the case of 67 Ga-DFO-lectins. While, these lectins accumulated in liver, spleen, lung, and kidney to a greater extent than 67 Ga citrate, the tumor to organ ratios became very low. These low tumor to organ ratios, in contrast to 67 Ga citrate, will certainly inhibit the tumor delineation, and therefore it seems that in spite of a high accumulation ratio of 67 Ga-DFO-lectins in tumor tissue, these agents are not useful in tumor detection. (orig.)

Introgressive hybridization: brown bears as vectors for polar bear alleles.

Science.gov (United States)

Hailer, Frank

2015-03-01

The dynamics and consequences of introgression can inform about numerous evolutionary processes. Biologists have therefore long been interested in hybridization. One challenge, however, lies in the identification of nonadmixed genotypes that can serve as a baseline for accurate quantification of admixture. In this issue of Molecular Ecology, Cahill et al. (2015) analyse a genomic data set of 28 polar bears, eight brown bears and one American black bear. Polar bear alleles are found to be introgressed into brown bears not only near a previously identified admixture zone on the Alaskan Admiralty, Baranof and Chichagof (ABC) Islands, but also far into the North American mainland. Elegantly contrasting admixture levels at autosomal and X chromosomal markers, Cahill and colleagues infer that male-biased dispersal has spread these introgressed alleles away from the Late Pleistocene contact zone. Compared to a previous study on the ABC Island population in which an Alaskan brown bear served as a putatively admixture-free reference, Cahill et al. (2015) utilize a newly sequenced Swedish brown bear as admixture baseline. This approach reveals that brown bears have been impacted by introgression from polar bears to a larger extent (up to 8.8% of their genome), than previously known, including the bear that had previously served as admixture baseline. No evidence for introgression of brown bear into polar bear is found, which the authors argue could be a consequence of selection. Besides adding new exciting pieces to the puzzle of polar/brown bear evolutionary history, the study by Cahill and colleagues highlights that wildlife genomics is moving from analysing single genomes towards a landscape genomics approach. © 2015 John Wiley & Sons Ltd.

Ganoderma lucidum total triterpenes attenuate DLA induced ascites and EAC induced solid tumours in Swiss albino mice.

Science.gov (United States)

Smina, T P; Mathew, J; Janardhanan, K K

2016-04-30

G. lucidum total triterpenes were assessed for its apoptosis-inducing and anti-tumour activities. The ability of the total triterpenes to induce apoptosis was evaluated in Dalton's lymphoma ascites (DLA) and Ehrlich's ascites carcinoma (EAC) cell lines. Total triterpenes were found to be highly cytotoxic to DLA and EAC cell lines with IC50 values 5 ± 0.32 and 7.9 ± 0.2 µg/ml respectively. Total triterpenes induced apoptosis in both cell lines which is evident from the DNA fragmentation assay. Anti-tumour activity was accessed using DLA induced solid and EAC induced ascites tumour models in Swiss albino mice. Administration of 10, 50 and 100 mg/kg b. wt. total triterpenes showed 11.86, 27.27 and 40.57% increase in life span of animals in ascites tumour model. Treatment with 10, 50 and 100 mg/kg b. wt. total triterpenes exhibited 76.86, 85.01 and 91.03% inhibition in tumour volume and 67.96, 72.38 and 77.90% inhibition in tumour weight respectively in the solid tumour model. The study reveals the significant dose-dependent anti-tumour activity of total triterpenes in both models. Total triterpenes were more active against the solid tumour than the ascites tumour. The anti-oxidant potential and ability to induce cell-specific apoptosis could be contributing to its anti-tumour activities.

Disseminated pleomorphic myofibrosarcoma in a grizzly bear (Ursus arctos horribilis).

Science.gov (United States)

Mete, A; Woods, L; Famini, D; Anderson, M

2012-01-01

The pathological and diagnostic features of a widely disseminated pleomorphic high-grade myofibroblastic sarcoma are described in a 23-year-old male brown bear (Ursus arctos horribilis). Firm, solid, white to tan neoplastic nodules, often with cavitated or soft grey-red necrotic centres, were observed throughout most internal organs, subcutaneous tissues and skeletal muscles on gross examination. Microscopically, the tumour consisted of pleomorphic spindle cells forming interlacing fascicles with a focal storiform pattern with large numbers of bizarre polygonal multinucleate cells, frequently within a collagenous stroma. Immunohistochemistry, Masson's trichrome stain and transmission electron microscopy designated the myofibroblast as the cell of origin. This is the first case of a high-grade myofibrosarcoma in a grizzly bear. Published by Elsevier Ltd.

Recovery of plutonium from the combustion residues of alpha-bearing solid wastes

International Nuclear Information System (INIS)

Gompper, K.; Wieczorek, H.

1991-01-01

Experimental researches on plutonium dioxide dissolution in nitric acid in inactive and alpha-bearing wastes are presented in this report. After a review of the literature published on dissolution methods of PuO 2 combustion residues. Then results obtained in the ALONA plant on the dissolution of plutonium containing ashes in sulfuric acid and nitric acid are presented. Plutonium purification is studied. At last a simplified scheme of processing based on results obtained

In vitro antitumour activity, safety testing and subcellular distribution of two poly[oxyethylene(aminophosphonate-co-H-phosphonate]s in Ehrlich ascites carcinoma and BALB/c 3T3 cell culture systems

Directory of Open Access Journals (Sweden)

Ani Georgieva

2016-01-01

Full Text Available Two polyphosphoesters containing anthracene-derived aminophosphonate and hydrophilic H-phosphonate repeating units, poly[oxyethylene(aminophosphonate-co-H-phosphonate]s (1 and 2, were tested for the in vitro antitumour activity on cell cultures derived from ascitic form of Ehrlich mammary adenocarcinoma by 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT-dye reduction assay. The in vitro safety testing of the copolymers was performed by BALB/c 3T3 neutral red uptake assay. A study on their uptake and subcellular distribution in non-tumourigenic and tumour cells was performed by means of fluorescence microscopy. Both copolymers showed significant antitumour activity towards Ehrlich ascites carcinoma (EAC cells. However, the in vitro safety testing revealed significant toxicity of polymer 2 to BALB/c 3T3 mouse embryo cells. In contrast, polymer 1 showed complete absence of cytotoxicity to BALB/c 3T3 cells. The fluorescent studies showed that the substances were diffusely distributed in the cytoplasm in both cell culture systems. As opposed to BALB/c 3T3 cells, in EAC cells, intense fluorescent signal was observed in the nuclei and in the perinuclear region. The tested polyphosphoesters are expected to act under physiological conditions as prodrugs of aminophosphonates.

Chaotic Dynamics of Cage Behavior in a High-Speed Cylindrical Roller Bearing

Directory of Open Access Journals (Sweden)

Long Chen

2016-01-01

Full Text Available This paper presents a mathematical model to investigate the nonlinear dynamic behavior of cage in high-speed cylindrical bearing. Variations of cage behavior due to varying cage eccentricity and cage guidance gap are observed. Hydrodynamic behavior in cage contacts is taken into consideration for a more realistic calculation of acting forces owing to high working speed. Analysis of real-time cage dynamic behavior on radial plane is carried out using chaos theory based on the theoretical and mathematical model established in the paper. The analytical results of this paper provide a solid foundation for designing and manufacturing of high-speed cylindrical roller bearing.

The R and D D`s bearing test benches; Les bancs d`essais de paliers de la DER

Energy Technology Data Exchange (ETDEWEB)

Vialettes, J.M. [Service Ensembles de Production, Departement Machines, Direction des Etudes et Recherches, Electricite de France (EDF), 92 - Clamart (France)

1997-01-01

In power generation plants, rotating machines are involved in energy transformation processes and safety systems. The bearings supporting the rotors and the thrust bearings play a crucial role in the reliability of these machines. The phenomena encountered straddle several disciplines: hydrodynamics, tribology, thermomechanics, materials and vibrations in a specific environment, namely: thin fluid film, solid mechanical components and shaft rotation. Means of analysing the behaviour of these components (bearings and thrust bearings) have been developed and implemented. These consists of the EDYOS (Etude Dynamique des Organes de Supportage) code for dynamically studying bearing devices and several related bench tests. In reality, in order to understand the complex physical phenomena encountered in these components, it is vital to carry out analyses and experimental validations. Since these investigations cannot be carried out on actual machines, test benches have been built which can subject the sample bearings to the equivalent stresses. (author) 14 figs.

Production of fungal antibiotics using polymeric solid supports in solid-state and liquid fermentation.

Science.gov (United States)

Bigelis, Ramunas; He, Haiyin; Yang, Hui Y; Chang, Li-Ping; Greenstein, Michael

2006-10-01

The use of inert absorbent polymeric supports for cellular attachment in solid-state fungal fermentation influenced growth, morphology, and production of bioactive secondary metabolites. Two filamentous fungi exemplified the utility of this approach to facilitate the discovery of new antimicrobial compounds. Cylindrocarpon sp. LL-Cyan426 produced pyrrocidines A and B and Acremonium sp. LL-Cyan416 produced acremonidins A-E when grown on agar bearing moist polyester-cellulose paper and generated distinctly different metabolite profiles than the conventional shaken or stationary liquid fermentations. Differences were also apparent when tenfold concentrated methanol extracts from these fermentations were tested against antibiotic-susceptible and antibiotic-resistant Gram-positive bacteria, and zones of inhibition were compared. Shaken broth cultures of Acremonium sp. or Cylindrocarpon sp. showed complex HPLC patterns, lower levels of target compounds, and high levels of unwanted compounds and medium components, while agar/solid support cultures showed significantly increased yields of pyrrocidines A and B and acremonidins A-E, respectively. This method, mixed-phase fermentation (fermentation with an inert solid support bearing liquid medium), exploited the increase in surface area available for fungal growth on the supports and the tendency of some microorganisms to adhere to solid surfaces, possibly mimicking their natural growth habits. The production of dimeric anthraquinones by Penicillium sp. LL-WF159 was investigated in liquid fermentation using various inert polymeric immobilization supports composed of polypropylene, polypropylene cellulose, polyester-cellulose, or polyurethane. This culture produced rugulosin, skyrin, flavomannin, and a new bisanthracene, WF159-A, after fermentation in the presence and absence of polymeric supports for mycelial attachment. The physical nature of the different support systems influenced culture morphology and relative

Laboratory Studies on the Formation of Carbon-Bearing Molecules in Extraterrestrial Environments: From the Gas Phase to the Solid State

Science.gov (United States)

Jamieson, C. S.; Guo, Y.; Gu, X.; Zhang, F.; Bennett, C. J.; Kaiser, R. I.

2006-01-01

A detailed knowledge of the formation of carbon-bearing molecules in interstellar ices and in the gas phase of the interstellar medium is of paramount interest to understand the astrochemical evolution of extraterrestrial environments (1). This research also holds strong implications to comprehend the chemical processing of Solar System environments such as icy planets and their moons together with the atmospheres of planets and their satellites (2). Since the present composition of each interstellar and Solar System environment reflects the matter from which it was formed and the processes which have changed the chemical nature since the origin (solar wind, planetary magnetospheres, cosmic ray exposure, photolysis, chemical reactions), a detailed investigation of the physicochemical mechanisms altering the pristine environment is of paramount importance to grasp the contemporary composition. Once these underlying processes have been unraveled, we can identify those molecules, which belonged to the nascent setting, distinguish molecular species synthesized in a later stage, and predict the imminent chemical evolution of, for instance, molecular clouds. Laboratory experiments under controlled physicochemical conditions (temperature, pressure, chemical composition, high energy components) present ideal tools for simulating the chemical evolution of interstellar and Solar System environments. Here, laboratory experiments can predict where and how (reaction mechanisms; chemicals necessary) in extraterrestrial environments and in the interstellar medium complex, carbon bearing molecules can be formed on interstellar grains and in the gas phase. This paper overviews the experimental setups utilized in our laboratory to mimic the chemical processing of gas phase and solid state (ices) environments. These are a crossed molecular beams machine (3) and a surface scattering setup (4). We also present typical results of each setup (formation of amino acids, aldehydes, epoxides

Muonium atoms in liquid and solid neopentane

International Nuclear Information System (INIS)

Ng, B.W.; Stadlbauer, J.M.; Jean, Y.C.; Walker, D.C.

1982-10-01

Relatively long-lived muonium atoms have been observed in neopentane (2,2-dimethylpropane). The yields of all muon states are found to be essentially the same in liquid and solid neopentane and the same as those in water. These results have bearings on three matters of current interest in muonium chemistry: the origin of the 'background' spin relaxation; the formation mechanisms; and the change in yields at the liquid-solid phase transition. These data were obtained by the μSR technique (muon spin rotation) at the TRIUMF accelerator

EcoBears

DEFF Research Database (Denmark)

Nielsen, Nick; Pedersen, Sandra Bleuenn; Sørensen, Jens Ager

2015-01-01

In this paper, we introduce the EcoBears concept that aims to augment household appliances with functional and aesthetic features to promote their "use'' and "longevity of use'' to prevent their disposal. The EcoBears also aim to support the communication of environmental issues in the home setting....... We present our initial design and implementation of the EcoBears that consist of two bear modules (a mother and her cub). We also present our preliminary concept validations and lessons learned to be considered for future directions....

Solid-Phase Synthesis of PEGylated Lipopeptides Using Click Chemistry

DEFF Research Database (Denmark)

Jølck, Rasmus Irming; Berg, Rolf Henrik; Andresen, Thomas Lars

2010-01-01

A versatile methodology for efficient synthesis of PEGylated lipopeptides via CuAAC “Click” conjugation between alkyne-bearing solid-supported lipopeptides and azido-functionalized PEGs is described. This new and very robust method offers a unique platform for synthesizing PEGylated lipopeptides ...

Stable isotopes to detect food-conditioned bears and to evaluate human-bear management

Science.gov (United States)

Hopkins, John B.; Koch, Paul L.; Schwartz, Charles C.; Ferguson, Jake M.; Greenleaf, Schuyler S.; Kalinowski, Steven T.

2012-01-01

We used genetic and stable isotope analysis of hair from free-ranging black bears (Ursus americanus) in Yosemite National Park, California, USA to: 1) identify bears that consume human food, 2) estimate the diets of these bears, and 3) evaluate the Yosemite human–bear management program. Specifically, we analyzed the isotopic composition of hair from bears known a priori to be food-conditioned or non-food-conditioned and used these data to predict whether bears with an unknown management status were food-conditioned (FC) or non-food-conditioned (NFC). We used a stable isotope mixing model to estimate the proportional contribution of natural foods (plants and animals) versus human food in the diets of FC bears. We then used results from both analyses to evaluate proactive (population-level) and reactive (individual-level) human–bear management, and discussed new metrics to evaluate the overall human–bear management program in Yosemite. Our results indicated that 19 out of 145 (13%) unknown bears sampled from 2005 to 2007 were food-conditioned. The proportion of human food in the diets of known FC bears likely declined from 2001–2003 to 2005–2007, suggesting proactive management was successful in reducing the amount of human food available to bears. In contrast, reactive management was not successful in changing the management status of known FC bears to NFC bears, or in reducing the contribution of human food to the diets of FC bears. Nine known FC bears were recaptured on 14 occasions from 2001 to 2007; all bears were classified as FC during subsequent recaptures, and human–bear management did not reduce the amount of human food in the diets of FC bears. Based on our results, we suggest Yosemite continue implementing proactive human–bear management, reevaluate reactive management, and consider removing problem bears (those involved in repeated bear incidents) from the population.

In vitro and in vivo studies of gadolinium-159 liposomes in cancer treatment

International Nuclear Information System (INIS)

Soares, Daniel Cristian Ferreira

2011-01-01

revealed an increase of about three times the tumor uptake. However, we observed that the two formulations were also significantly accumulated in the liver and spleen. Therefore, studies were conducted biochemical and hematological, which revealed acute changes in hepatocytes and transient bone marrow. To study the antitumor activity, tumor bearing Swiss mice solid Ehrlich received three doses of 159 Gd-SpHL and three levels of 159 Gd-FTSpHL (each dose = 236mg/kg). The treatment inhibited the increase in the 3 volume of tumors compared with animals treated with NaCl (0.9% w/v). There was also inhibition of body mass gain and an increased survival of animals studied. Considering ali results, the pH-sensitive liposomes containing the radioactive complex 159 Gd-DTPA- BMA can be considered a potential therapeutic agent for cancer. (author)

State Space Formulation of Nonlinear Vibration Responses Collected from a Dynamic Rotor-Bearing System: An Extension of Bearing Diagnostics to Bearing Prognostics.

Science.gov (United States)

Tse, Peter W; Wang, Dong

2017-02-14

Bearings are widely used in various industries to support rotating shafts. Their failures accelerate failures of other adjacent components and may cause unexpected machine breakdowns. In recent years, nonlinear vibration responses collected from a dynamic rotor-bearing system have been widely analyzed for bearing diagnostics. Numerous methods have been proposed to identify different bearing faults. However, these methods are unable to predict the future health conditions of bearings. To extend bearing diagnostics to bearing prognostics, this paper reports the design of a state space formulation of nonlinear vibration responses collected from a dynamic rotor-bearing system in order to intelligently predict bearing remaining useful life (RUL). Firstly, analyses of nonlinear vibration responses were conducted to construct a bearing health indicator (BHI) so as to assess the current bearing health condition. Secondly, a state space model of the BHI was developed to mathematically track the health evolution of the BHI. Thirdly, unscented particle filtering was used to predict bearing RUL. Lastly, a new bearing acceleration life testing setup was designed to collect natural bearing degradation data, which were used to validate the effectiveness of the proposed bearing prognostic method. Results show that the prediction accuracy of the proposed bearing prognostic method is promising and the proposed bearing prognostic method is able to reflect future bearing health conditions.

State Space Formulation of Nonlinear Vibration Responses Collected from a Dynamic Rotor-Bearing System: An Extension of Bearing Diagnostics to Bearing Prognostics

Directory of Open Access Journals (Sweden)

Peter W. Tse

2017-02-01

Full Text Available Bearings are widely used in various industries to support rotating shafts. Their failures accelerate failures of other adjacent components and may cause unexpected machine breakdowns. In recent years, nonlinear vibration responses collected from a dynamic rotor-bearing system have been widely analyzed for bearing diagnostics. Numerous methods have been proposed to identify different bearing faults. However, these methods are unable to predict the future health conditions of bearings. To extend bearing diagnostics to bearing prognostics, this paper reports the design of a state space formulation of nonlinear vibration responses collected from a dynamic rotor-bearing system in order to intelligently predict bearing remaining useful life (RUL. Firstly, analyses of nonlinear vibration responses were conducted to construct a bearing health indicator (BHI so as to assess the current bearing health condition. Secondly, a state space model of the BHI was developed to mathematically track the health evolution of the BHI. Thirdly, unscented particle filtering was used to predict bearing RUL. Lastly, a new bearing acceleration life testing setup was designed to collect natural bearing degradation data, which were used to validate the effectiveness of the proposed bearing prognostic method. Results show that the prediction accuracy of the proposed bearing prognostic method is promising and the proposed bearing prognostic method is able to reflect future bearing health conditions.

Comparison of Alignment Correction Angles Between Fixed-Bearing and Mobile-Bearing UKA.

Science.gov (United States)

Inoue, Atsuo; Arai, Yuji; Nakagawa, Shuji; Inoue, Hiroaki; Yamazoe, Shoichi; Kubo, Toshikazu

2016-01-01

Good outcomes have been reported with both fixed-bearing and mobile-bearing unicompartmental knee arthroplasty (UKA). However, overcorrected alignment could induce the progression of arthritis on the non-arthroplasty side. Changes of limb alignment after UKA with both types of bearings (fixed bearing: 24 knees, mobile bearing: 28 knees) were investigated. The mean difference between the preoperative standing femoral-tibial angle (FTA) and postoperative standing FTA was significantly larger in mobile bearing UKA group. In fixed-bearing UKA, there must be some laxity in MCL tension so that a 2-mm tension gauge can be inserted. In mobile-bearing UKA, appropriate MCL tension is needed to prevent bearing dislocation. This difference in MCL tension may have caused the difference in the correction angle between the groups. Copyright © 2016 Elsevier Inc. All rights reserved.

Kint3-4 protein from human plasminogen delays Ehrlich tumor growth in mice Efeito da proteína Kint3-4 do plasminogênio humano no crescimento do tumor de Ehrlich

Directory of Open Access Journals (Sweden)

Cristina Maria de Souza

2011-08-01

Full Text Available INTRODUCTION AND OBJECTIVE: Kint3-4 protein, originated from a genetic recombination of K1-3 and K1-4 human plasminogen segments, is recognized for its antiangiogenic and anti-inflammatory potential. This study aimed to evaluate the effect of Kint3-4 protein on tumor development in Swiss mice previously inoculated with Ehrlich tumor cells. METHODS: The protein fragment was obtained from Pichia pastoris cloning and transformation. After tumor cell inoculation three different protocols were used to assess tumor growth: beginning (0-6 days, peak (0-12 days and after peak (0-18 days. We analyzed tumor growth, histomorphological characteristics and immunohistochemistry by use of CDC47 (cellular proliferation marker and CD31 (blood vessel marker. RESULTS: Animals treated with Kint3-4 protein (150 µg/kg/48 h showed lower tumor growth in all protocols. Based on histological assessment, inflammation and tumor areas were also reduced. Moreover, both the lowest rate of tumor cell proliferation and low microvessel density were observed in animals treated with Kint3-4 protein compared with the untreated control group. CONCLUSION: The effect of Kint3-4 recombinant protein on tumor angiogenesis and control of malignant cell proliferation enhances the prospects of its use in clinical and antiangiogenic treatment.INTRODUÇÃO E OBJETIVO: A proteína Kint3-4 originou-se a partir de uma recombinação genética dos segmentos K1-3 e K1--4 do plasminogênio humano e é reconhecida por seu potencial anti-inflamatório e antiangiogênico. Este estudo teve como objetivo avaliar o efeito da proteína Kint3-4 no desenvolvimento de tumores em camundongos inoculados com células do tumor de Ehrlich. MÉTODOS: O fragmento de proteína foi obtido por uma técnica de clonagem e transformação de Pichia pastoris. Três diferentes protocolos foram avaliados após a inoculação das células tumorais: no início (0-6 dias, no pico (0-12 dias e após o pico (0-18 dias de

Analytical evaluation of the roller bearing service life

Directory of Open Access Journals (Sweden)

Antsupov Aleksey

2017-01-01

Full Text Available An analytical method has been developed for the design evaluation of the service life of roller bearings by the criterion of contact endurance of elements that does not require carrying out the experimental studies. It is based on the kinetic approach to the description of the solids destruction process and the theory of parametric reliability of machine parts. In contradistinction to the standard empirical dependence, which is currently used, the method allows one to take into account the effect of the material properties, and basic design and operational parameters on the service life. The results of the theoretical studies of the service life of roller bearing No. 212 (DIN 5412 T1 are presented for the quantitative assessment of this effect. They showed that the temperature-force loading conditions or material properties that were not taken into account might result in the prediction error of 1.5 or more times.

Supply of clean water to the bearings and mechanical seals of the backup pumps

International Nuclear Information System (INIS)

Jolas, C.

1997-01-01

The purpose of the backup pumps is to cool the primary circuit and pressurised water reactor containment in the case of a primary cooler loss accident. The water taken in by these pumps in the case of accident is loaded with solid particles. In order to ensure correct operation of the bearings and mechanical seals of these machines, they must be supplied with clean water. In other words, the solid particles must be removed from the water intake. Manufacturers generally use cyclonic separators to achieve this. (author)

A review of bear farming and bear trade in Lao People's Democratic Republic

Directory of Open Access Journals (Sweden)

E. Livingstone

2018-01-01

Full Text Available This study reviews the bear farming industry in Lao PDR with the objective of documenting the current number of commercial bear facilities (i.e. captive bear facilities judged to be trading in bear bile and/or bears and bear parts and the number of bears contained within these facilities, noting changes since it was last examined between 2000 and 2012 by Livingstone and Shepherd (2014. We surveyed all known commercial bear facilities and searched for previously unrecorded facilities. We compared our records with Livingstone and Shepherd (2014 and corrected some duplicate records from their study. In 2017, we recorded seven commercial facilities; four dedicated bear farms, and three tiger farms that were reportedly also keeping bears. We found that between 2012 and 2017 the recorded number of dedicated bear farms reduced by two, and the recorded number of tiger farms also keeping bears increased by one. Within the same period, the total number of captive bears among all facilities in Lao PDR hardly changed (+one, but the number of bears within each facility did. The northern facilities, owned by ethnic Chinese, have expanded since 2012, and central and southern facilities have downsized or closed. While bear farming appears to be downsizing in Lao PDR overall, efforts to phase it out are undermined by the expansion of foreign owned facilities in the north, within Special and Specific Economic Zones that largely cater to a Chinese market, and where the Lao government's efforts to enforce laws and protect wildlife appear to be lacking. Closing the facilities in the north will require political will and decisive law enforcement. Keywords: Bear farms, Bear bile, Gall bladder, Urso-deoxycholic acid, Bear bile extraction facilities, Lao PDR, Ursus thibetanus

Molecular phylogeny and SNP variation of polar bears (Ursus maritimus), brown bears (U. arctos), and black bears (U. americanus) derived from genome sequences.

Science.gov (United States)

Cronin, Matthew A; Rincon, Gonzalo; Meredith, Robert W; MacNeil, Michael D; Islas-Trejo, Alma; Cánovas, Angela; Medrano, Juan F

2014-01-01

We assessed the relationships of polar bears (Ursus maritimus), brown bears (U. arctos), and black bears (U. americanus) with high throughput genomic sequencing data with an average coverage of 25× for each species. A total of 1.4 billion 100-bp paired-end reads were assembled using the polar bear and annotated giant panda (Ailuropoda melanoleuca) genome sequences as references. We identified 13.8 million single nucleotide polymorphisms (SNP) in the 3 species aligned to the polar bear genome. These data indicate that polar bears and brown bears share more SNP with each other than either does with black bears. Concatenation and coalescence-based analysis of consensus sequences of approximately 1 million base pairs of ultraconserved elements in the nuclear genome resulted in a phylogeny with black bears as the sister group to brown and polar bears, and all brown bears are in a separate clade from polar bears. Genotypes for 162 SNP loci of 336 bears from Alaska and Montana showed that the species are genetically differentiated and there is geographic population structure of brown and black bears but not polar bears.

Teddy Bear Stories

DEFF Research Database (Denmark)

van Leeuwen, Theo; Caldas-Coulthardt, Carmen

2014-01-01

This paper presents a semiotic analysis of a key cultural artefact, the teddy bear. After introducing the iconography of the teddy bear, it analyses different kinds of stories to show how teddy bears are endowed with meaning in everyday life: stories from children's books, reminiscenses by adults...... bears have traditionally centred on interpersonal relations within the nuclear family, but have recently been institutionalized and commercialized....

“Bear-ly” learning: Limits of abstraction in black bear cognition

Directory of Open Access Journals (Sweden)

Jennifer Vonk

2018-02-01

Full Text Available We presented two American black bears (Ursus americanus with a serial list learning memory task, and one of the bears with a matching-to-sample task. After extended training, both bears demonstrated some success with the memory task but failed to generalize the overarching rule of the task to novel stimuli. Matching to sample proved even more difficult for our bear to learn. We conclude that, despite previous success in training bears to respond to natural categories, quantity discriminations, and other related tasks, that bears may possess a cognitive limitation with regards to learning abstract rules. Future tests using different procedures are necessary to determine whether this is a limit of bears’ cognitive capacities, or a limitation of the current tasks as presented. Future tests should present a larger number of varying stimuli. Ideally, bears of various species should be tested on these tasks to demonstrate species as well as individual differences.

GAS BEARING

Science.gov (United States)

Skarstrom, C.W.

1960-09-01

A gas lubricated bearing for a rotating shaft is described. The assembly comprises a stationary collar having an annular member resiliently supported thereon. The collar and annular member are provided with cooperating gas passages arranged for admission of pressurized gas which supports and lubricates a bearing block fixed to the rotatable shaft. The resilient means for the annular member support the latter against movement away from the bearing block when the assembly is in operation.

Controlled-air incineration of alpha-bearing solid wastes

International Nuclear Information System (INIS)

Koenig, R.A.; Draper, W.E.; Neuls, A.S.; Newmyer, J.M.

1980-01-01

The Los Alamos Scientific Laboratory is completing a study of controlled-air incineration (CAI) as a technique for volume reduction and stabilization of combustible transuranic-contaminated solid wastes. To demonstrate feasibility, a process has been assembled and operated on synthetic and contaminated combustibles. This paper summarizes the CAI project history, process design, provisions for radioactive operation, experimental results to date, and future plans. Achievements include operation at the design feed rate as well as combustion of separate feed compositions including cellulosics, polyethylene, polyvinyl chloride (PVC) and latex rubber. Refractory life has been satisfactory to date, with studies continuing. The offgas cleanup system has proven to be extremely effective; the final high-efficiency filters showing virtually no pressure drop increase. The ability of the system to process high concentrations of PVC has been demonstrated with no chloride-induced degradation detected. Chloride and sulfate removal from the offgas has been excellent with concentrations reaching 8 and 10 ppM maximum, respectively, in the process condensate

Genomic evidence of geographically widespread effect of gene flow from polar bears into brown bears.

Science.gov (United States)

Cahill, James A; Stirling, Ian; Kistler, Logan; Salamzade, Rauf; Ersmark, Erik; Fulton, Tara L; Stiller, Mathias; Green, Richard E; Shapiro, Beth

2015-03-01

Polar bears are an arctic, marine adapted species that is closely related to brown bears. Genome analyses have shown that polar bears are distinct and genetically homogeneous in comparison to brown bears. However, these analyses have also revealed a remarkable episode of polar bear gene flow into the population of brown bears that colonized the Admiralty, Baranof and Chichagof islands (ABC islands) of Alaska. Here, we present an analysis of data from a large panel of polar bear and brown bear genomes that includes brown bears from the ABC islands, the Alaskan mainland and Europe. Our results provide clear evidence that gene flow between the two species had a geographically wide impact, with polar bear DNA found within the genomes of brown bears living both on the ABC islands and in the Alaskan mainland. Intriguingly, while brown bear genomes contain up to 8.8% polar bear ancestry, polar bear genomes appear to be devoid of brown bear ancestry, suggesting the presence of a barrier to gene flow in that direction. © 2014 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd.

EFFECT OF CLEARANCE THE BALL BEARINGS ON INCORRECT WORK OF THREE-SUPORT BEARING SHAFT

Directory of Open Access Journals (Sweden)

Jarosław KACZOR

2014-06-01

Full Text Available Durability deep groove ball bearings depends on factors (called attributes design, technological and operational. Among the design features one of the most important is play in the bearings. Polish Norm shows five groups of looseness in the bearings, in which the play range from 0 to 105 microns. Manufacturers of rolling bearings they only play group, which has a bearing data, without giving the exact value of the slack. Aim of this study is to determine how it affects the play in the bearings to work three-bearing shafts, including elasticity and resilience three-bearing shafts.

Study of crotoxin mechanism of action to mammary carcinomas and evaluation of its potential as a radiopharmaceutical

International Nuclear Information System (INIS)

Silveira, Marina Bicalho

2010-01-01

Crotoxin, the main component of Crotalus durissus terrificus snake venom, has been studied since 1938. It is a natural polypeptidic complex with pharmacological potential because of its antitumoral properties which has attracted great interest for diagnosis and therapy of oncological diseases. However, Crotoxin mechanism of action and sites of specific interaction on tumor cells are still misunderstood. Breast cancer is the second most frequent type in the world and the most common cancer in women. About 30 to 60% of mammary tumors overexpress epidermal growth factor receptor (EGFR), a transmembrane protein related to cell proliferation. Since literature has reported that Crotoxin antitumoral effect is more potent on cells with EGFR overexpression the objectives of this work were to evaluate Crotoxin cytotoxic effects on mammary tumor cells human breast carcinoma (MCF-7) and Ehrlich tumor cells (murine ascitics carcinoma), and to investigate the specific molecular interaction of Crotoxin on Ehrlich tumor cells. Initially, Crotoxin was radiolabelled with iodine-125 ( 125 I-Crotoxin) and iodine-131 ( 131 I-Crotoxin). Saturation and competition assay were carried out to characterize Crotoxin in vitro interaction; Crotoxin biodistribution studies and singlephoton emission computed tomography (SPECT) of mice bearing Ehrlich tumor have been evaluated to describe in vivo interaction. Our results showed that Crotoxin presented cytotoxic effect against Ehrlich with DL 50 in vitro (concentration of compound which is lethal for 50% of cells) of about one micromolar, but did not present significant effect against MCF-7. Morphological alterations characteristic of apoptosis suggests programmed cell death. 125 I-Crotoxin interaction with Ehrlich tumor cells was saturable with approximately 70% specificity, and presented K d =24.98 nmol/L and B max =16,570 sites/cell for low affinity binding sites and K d =0.06 nmol/L and B max =210 sites/cell high affinity binding sites

Management of metal-bearing industrial solid waste by stabilization/solidification process

Energy Technology Data Exchange (ETDEWEB)

Sunitha, C.; Palanivelu, K. [Anna University, Chennai (India). Centre for Environmental Studies

2005-07-01

Metal-bearing sludge from an electroplating industry was immobilised by the solidification stabilisation treatment method. Reduction of the leachability of metals from the waste was studied in different combinations of waste and additives - cement, lime and fly ash. The study revealed that the optimum proportion for cement: metal hydroxide sludge: fly ash as 1:2:2 is the best. The encapsulation efficiency calculated for the metals such as Cu, Cr, Ni, Pb, and Zn was above 92%. The unconfined compressive strength (UCS) for the developed block was found to be 11.5 kg/cm{sup 2} after curing. The toxicity characteristic leach test (TCLP) test reveals that the heavy metal content in the leachate was well below the maximum permissible limit of WHO drinking water standard. 10 refs., 6 tabs.

Geology and geomorphology of Bear Lake Valley and upper Bear River, Utah and Idaho

Science.gov (United States)

Reheis, M.C.; Laabs, B.J.C.; Kaufman, D.S.

2009-01-01

Bear Lake, on the Idaho-Utah border, lies in a fault-bounded valley through which the Bear River flows en route to the Great Salt Lake. Surficial deposits in the Bear Lake drainage basin provide a geologic context for interpretation of cores from Bear Lake deposits. In addition to groundwater discharge, Bear Lake received water and sediment from its own small drainage basin and sometimes from the Bear River and its glaciated headwaters. The lake basin interacts with the river in complex ways that are modulated by climatically induced lake-level changes, by the distribution of active Quaternary faults, and by the migration of the river across its fluvial fan north of the present lake. The upper Bear River flows northward for ???150 km from its headwaters in the northwestern Uinta Mountains, generally following the strike of regional Laramide and late Cenozoic structures. These structures likely also control the flow paths of groundwater that feeds Bear Lake, and groundwater-fed streams are the largest source of water when the lake is isolated from the Bear River. The present configuration of the Bear River with respect to Bear Lake Valley may not have been established until the late Pliocene. The absence of Uinta Range-derived quartzites in fluvial gravel on the crest of the Bear Lake Plateau east of Bear Lake suggests that the present headwaters were not part of the drainage basin in the late Tertiary. Newly mapped glacial deposits in the Bear River Range west of Bear Lake indicate several advances of valley glaciers that were probably coeval with glaciations in the Uinta Mountains. Much of the meltwater from these glaciers may have reached Bear Lake via groundwater pathways through infiltration in the karst terrain of the Bear River Range. At times during the Pleistocene, the Bear River flowed into Bear Lake and water level rose to the valley threshold at Nounan narrows. This threshold has been modified by aggradation, downcutting, and tectonics. Maximum lake

State Space Formulation of Nonlinear Vibration Responses Collected from a Dynamic Rotor-Bearing System: An Extension of Bearing Diagnostics to Bearing Prognostics

OpenAIRE

Peter W. Tse; Dong Wang

2017-01-01

Bearings are widely used in various industries to support rotating shafts. Their failures accelerate failures of other adjacent components and may cause unexpected machine breakdowns. In recent years, nonlinear vibration responses collected from a dynamic rotor-bearing system have been widely analyzed for bearing diagnostics. Numerous methods have been proposed to identify different bearing faults. However, these methods are unable to predict the future health conditions of bearings. To exten...

Continuous distillation of oil-bearing rocks

Energy Technology Data Exchange (ETDEWEB)

1923-11-14

A continuous process of distilling petroleum-bearing, asphaltic, or bituminous rocks to free bitumen is characterized by vaporizing hydrocarbons solid, pasty, or liquid from petroleum-containing asphaltic or bituminous rocks to free bitumen without ever reaching the temperatures at which they can produce decomposition, the necessary heat being furnished by combustion of part of the hydrocarbons of the treated rocks. A furnace for carrying out the process of claim 1 is characterized by consisting of a cavity lined inside with reflector, of variable section and with a throat at the upper part for charging the material to be treated and means for blowing the lower part of the furnace with the air necessary for combustion and inert gas for regulating the combustion and removal of the hydrocarbons.

Evaluation of bearing configurations using the single bearing tester in liquid nitrogen

Science.gov (United States)

Jett, T.; Hall, P.; Thom, R.

1991-01-01

Various bearing configurations were tested using the Marshall Space Flight Center single bearing tester with LN2 as the cryogenic coolant. The baseline was one Rocketdyne phase one high pressure oxidizer turbopump (HPOTP) pump end 45-mm bore bearing. The bearing configurations that were tested included a Salox/M cage configuration, a silicon nitride ball configuration, an elongated cage configuration, and a Bray 601 grease configuration.

An investigation of the shedding of macromolecules from the Ehrlich mouse ascites tumor cell

International Nuclear Information System (INIS)

Edwards, E.H.

1984-01-01

The spontaneous release, or shedding, of cell surface components into the extracellular medium may be important in the determination of several features of the cancer cell phenotype. The release of macromolecules from the Erhlich mouse ascites tumor cell was studied under a variety of experimental conditions to elucidate the origin and the underlying mechanisms of release. The extrinsic macromolecules are a diverse group with apparent molecular weights ranging from 13,500 to 400,000 daltons. External labeling of the cell surface with tritiated 4,4'-diisothiocyano-1,2-diphenylethane-2,2-disulfonic acid ([ 3 H]H 2 DIDS) reveals a slow loss of labeled components at 4 degrees C, while at 21 degrees C and 37 degrees C an initial rapid loss is followed by a slower release. In vitro metabolic labeling with [1- 14 C]-D-glucosamine hydrochloride, D-[2- 3 H]-mannose and various [ 3 H]-L-amino acids results in the appearance of labeled macromolecules in the medium suggesting tumor, not mouse, origin. These data suggest that the extrinsic macromolecules originate from the cell surface. Macromolecules are shed by a temperature and pH sensitive process. These results suggest that a limited proteolytic digestion, or sublethal autolysis, of the cell surface may occur in this system. The macromolecules shed by the Ehrlich cell originate from the surface and are probably released by sublethal autolysis, direct secretion and a passive process

Improvement of journal bearing operation at heavy misalignment using bearing flexibility and compliant liners

DEFF Research Database (Denmark)

Thomsen, Kim; Klit, Peder

2012-01-01

A flexure journal bearing design is proposed that will improve operational behaviour of a journal bearing at pronounced misalignment. Using a thermoelastohydrodynamic model, it is shown that the proposed flexure journal bearing has vastly increased the hydrodynamic performance compared to the stiff...... bearing when misaligned. The hydrodynamic performance is evaluated on lubricant film thickness, pressure and temperature. Furthermore, the influence of a compliant bearing liner is investigated and it is found that it increases the hydrodynamic performance when applied to a stiff bearing, whereas...... the liner has practically no influence on the flexure journal bearing's performance....

Effects of a combined Bleomycin/radiotherapy on the increase of cell numbers in Ehrlich ascitic carcinoma

International Nuclear Information System (INIS)

Mueller, W.A.

1980-01-01

The effects of separate and combined application of the cytostatic Bleomycin and X-radiation on the multiplication of the Ehrlich ascitic tumour cells in vivo and on the survival time of tumourous mice was examined by applying automatic, electronic cell counting. If this cytostatic is administered alone up to 100 mg/kg the growth curve of the EAT-cells shows, after a 24 hours' delay, hardly any difference to that of untreated tumour cells. The separate administration of such Bleomycin doses and the separate X-radiation of the EAT cells with doses of up to 1000 rad had no significant influence on the survival time of tumourous mice. The combined application of Bleomycin and X-radiation elongates the 50%-survival time of the tumourous mice. If the X-radiation takes place 12 hours after the Bleomycin treatment the animals survive longer than is the case with simultaneous treatment. Although no dose effect curves could be set up the results obtained let assume a synergistic effect of Bleomycin and irradiation which is especially significant if the radiation is carried out 12 hours after a Bleomycin treatment. The reasons of this are assumed to lie in the increased radiation sensitivity of the tumour cells caused by the bleomycin-induced partial synchronisation of the EAT cells. (orig.) [de

Nuclear genomic sequences reveal that polar bears are an old and distinct bear lineage.

Science.gov (United States)

Hailer, Frank; Kutschera, Verena E; Hallström, Björn M; Klassert, Denise; Fain, Steven R; Leonard, Jennifer A; Arnason, Ulfur; Janke, Axel

2012-04-20

Recent studies have shown that the polar bear matriline (mitochondrial DNA) evolved from a brown bear lineage since the late Pleistocene, potentially indicating rapid speciation and adaption to arctic conditions. Here, we present a high-resolution data set from multiple independent loci across the nuclear genomes of a broad sample of polar, brown, and black bears. Bayesian coalescent analyses place polar bears outside the brown bear clade and date the divergence much earlier, in the middle Pleistocene, about 600 (338 to 934) thousand years ago. This provides more time for polar bear evolution and confirms previous suggestions that polar bears carry introgressed brown bear mitochondrial DNA due to past hybridization. Our results highlight that multilocus genomic analyses are crucial for an accurate understanding of evolutionary history.

Vibration model of rolling element bearings in a rotor-bearing system for fault diagnosis

Science.gov (United States)

Cong, Feiyun; Chen, Jin; Dong, Guangming; Pecht, Michael

2013-04-01

Rolling element bearing faults are among the main causes of breakdown in rotating machines. In this paper, a rolling bearing fault model is proposed based on the dynamic load analysis of a rotor-bearing system. The rotor impact factor is taken into consideration in the rolling bearing fault signal model. The defect load on the surface of the bearing is divided into two parts, the alternate load and the determinate load. The vibration response of the proposed fault signal model is investigated and the fault signal calculating equation is derived through dynamic and kinematic analysis. Outer race and inner race fault simulations are realized in the paper. The simulation process includes consideration of several parameters, such as the gravity of the rotor-bearing system, the imbalance of the rotor, and the location of the defect on the surface. The simulation results show that different amplitude contributions of the alternate load and determinate load will cause different envelope spectrum expressions. The rotating frequency sidebands will occur in the envelope spectrum in addition to the fault characteristic frequency. This appearance of sidebands will increase the difficulty of fault recognition in intelligent fault diagnosis. The experiments given in the paper have successfully verified the proposed signal model simulation results. The test rig design of the rotor bearing system simulated several operating conditions: (1) rotor bearing only; (2) rotor bearing with loader added; (3) rotor bearing with loader and rotor disk; and (4) bearing fault simulation without rotor influence. The results of the experiments have verified that the proposed rolling bearing signal model is important to the rolling bearing fault diagnosis of rotor-bearing systems.

Polar bears at risk

Energy Technology Data Exchange (ETDEWEB)

Norris, S.; Rosentrater, L.; Eid, P.M. [WWF International Arctic Programme, Oslo (Norway)

2002-05-01

Polar bears, the world's largest terrestrial carnivore, spend much of their lives on the arctic sea ice. This is where they hunt and move between feeding, denning, and resting areas. The world population, estimated at 22,000 bears, is made up of 20 relatively distinct populations varying in size from a few hundred to a few thousand animals. About 60 per cent of all polar bears are found in Canada. In general, the status of this species is stable, although there are pronounced differences between populations. Reductions in the extent and thickness of sea ice has lead the IUCN Polar Bear Specialist Group to describe climate change as one of the major threats facing polar bears today. Though the long-term effects of climate change will vary in different areas of the Arctic, impacts on the condition and reproductive success of polar bears and their prey are likely to be negative. Longer ice-free periods resulting from earlier break-up of sea ice in the spring and later formation in the fall is already impacting polar bears in the southern portions of their range. In Canada's Hudson Bay, for example, bears hunt on the ice through the winter and into early summer, after which the ice melts completely, forcing bears ashore to fast on stored fat until freeze-up in the fall. The time bears have on the ice to hunt and build up their body condition is cut short when the ice melts early. Studies from Hudson Bay show that for every week earlier that ice break-up occurs, bears will come ashore 10 kg lighter and in poorer condition. It is likely that populations of polar bears dividing their time between land and sea will be severely reduced and local extinctions may occur as greenhouse gas emissions continue to rise and sea ice melts. Expected changes in regional weather patterns will also impact polar bears. Rain in the late winter can cause maternity dens to collapse before females and cubs have departed, thus exposing occupants to the elements and to predators. Such

Ambient Pressure Test Rig Developed for Testing Oil-Free Bearings in Alternate Gases and Variable Pressures

Science.gov (United States)

Bauman, Steven W.

1990-01-01

The Oil-Free Turbomachinery research team at the NASA Glenn Research Center is conducting research to develop turbomachinery systems that utilize high-speed, high temperature foil (air) bearings that do not require an oil lubrication system. Such systems combine the most advanced foil bearings from industry with NASA-developed hightemperature solid-lubricant technology. New applications are being pursued, such as Oil- Free turbochargers, auxiliary power units, and turbine propulsion systems for aircraft. An Oil-Free business jet engine, for example, would be simpler, lighter, more reliable, and less costly to purchase and maintain than current engines. Another application is NASA's Prometheus mission, where gas bearings will be required for the closed-cycle turbine based power-conversion system of a nuclear power generator for deep space. To support these applications, Glenn's Oil-Free Turbomachinery research team developed the Ambient Pressure Test Rig. Using this facility, researchers can load and heat a bearing and evaluate its performance with reduced air pressure to simulate high altitude conditions. For the nuclear application, the test chamber can be purged with gases such as helium to study foil gas bearing operation in working fluids other than air.

Transient Vibration Prediction for Rotors on Ball Bearings Using Load-dependent Non-linear Bearing Stiffness

Science.gov (United States)

Fleming, David P.; Poplawski, J. V.

2002-01-01

Rolling-element bearing forces vary nonlinearly with bearing deflection. Thus an accurate rotordynamic transient analysis requires bearing forces to be determined at each step of the transient solution. Analyses have been carried out to show the effect of accurate bearing transient forces (accounting for non-linear speed and load dependent bearing stiffness) as compared to conventional use of average rolling-element bearing stiffness. Bearing forces were calculated by COBRA-AHS (Computer Optimized Ball and Roller Bearing Analysis - Advanced High Speed) and supplied to the rotordynamics code ARDS (Analysis of Rotor Dynamic Systems) for accurate simulation of rotor transient behavior. COBRA-AHS is a fast-running 5 degree-of-freedom computer code able to calculate high speed rolling-element bearing load-displacement data for radial and angular contact ball bearings and also for cylindrical and tapered roller beatings. Results show that use of nonlinear bearing characteristics is essential for accurate prediction of rotordynamic behavior.

Local Attitudes towards Bear Management after Illegal Feeding and Problem Bear Activity.

Science.gov (United States)

Dubois, Sara; Fraser, David

2013-09-12

The "pot bears" received international media attention in 2010 after police discovered the intentional feeding of over 20 black bears during the investigation of an alleged marijuana-growing operation in Christina Lake, British Columbia, Canada. A two-phase random digit dialing survey of the community was conducted in 2011 to understand local perspectives on bear policy and management, before and after a summer of problem bear activity and government interventions. Of the 159 households surveyed in February 2011, most had neutral or positive attitudes towards bears in general, and supported the initial decision to feed the food-conditioned bears until the autumn hibernation. In contrast to wildlife experts however, most participants supported relocating the problem bears, or allowing them to remain in the area, ahead of killing; in part this arose from notions of fairness despite the acknowledged problems of relocation. Most locals were aware of the years of feeding but did not report it, evidently failing to see it as a serious form of harm, even after many bears had been killed. This underscores the importance of preventive action on wildlife feeding and the need to narrow the gap between public and expert opinion on the likely effects of relocation versus killing.

Methane Flux and Authigenic Carbonate in Shallow Sediments Overlying Methane Hydrate Bearing Strata in Alaminos Canyon, Gulf of Mexico

Directory of Open Access Journals (Sweden)

Joseph P. Smith

2014-09-01

Full Text Available In June 2007 sediment cores were collected in Alaminos Canyon, Gulf of Mexico across a series of seismic data profiles indicating rapid transitions between the presence of methane hydrates and vertical gas flux. Vertical profiles of dissolved sulfate, chloride, calcium, magnesium, and dissolved inorganic carbon (DIC concentrations in porewaters, headspace methane, and solid phase carbonate concentrations were measured at each core location to investigate the cycling of methane-derived carbon in shallow sediments overlying the hydrate bearing strata. When integrated with stable carbon isotope ratios of DIC, geochemical results suggest a significant fraction of the methane flux at this site is cycled into the inorganic carbon pool. The incorporation of methane-derived carbon into dissolved and solid inorganic carbon phases represents a significant sink in local carbon cycling and plays a role in regulating the flux of methane to the overlying water column at Alaminos Canyon. Targeted, high-resolution geochemical characterization of the biogeochemical cycling of methane-derived carbon in shallow sediments overlying hydrate bearing strata like those in Alaminos Canyon is critical to quantifying methane flux and estimating methane hydrate distributions in gas hydrate bearing marine sediments.

Benchmarking the DFT+U method for thermochemical calculations of uranium molecular compounds and solids.

Science.gov (United States)

Beridze, George; Kowalski, Piotr M

2014-12-18

Ability to perform a feasible and reliable computation of thermochemical properties of chemically complex actinide-bearing materials would be of great importance for nuclear engineering. Unfortunately, density functional theory (DFT), which on many instances is the only affordable ab initio method, often fails for actinides. Among various shortcomings, it leads to the wrong estimate of enthalpies of reactions between actinide-bearing compounds, putting the applicability of the DFT approach to the modeling of thermochemical properties of actinide-bearing materials into question. Here we test the performance of DFT+U method--a computationally affordable extension of DFT that explicitly accounts for the correlations between f-electrons - for prediction of the thermochemical properties of simple uranium-bearing molecular compounds and solids. We demonstrate that the DFT+U approach significantly improves the description of reaction enthalpies for the uranium-bearing gas-phase molecular compounds and solids and the deviations from the experimental values are comparable to those obtained with much more computationally demanding methods. Good results are obtained with the Hubbard U parameter values derived using the linear response method of Cococcioni and de Gironcoli. We found that the value of Coulomb on-site repulsion, represented by the Hubbard U parameter, strongly depends on the oxidation state of uranium atom. Last, but not least, we demonstrate that the thermochemistry data can be successfully used to estimate the value of the Hubbard U parameter needed for DFT+U calculations.

Genetic relationships of extant brown bears (Ursus arctos) and polar bears (Ursus maritimus).

Science.gov (United States)

Cronin, Matthew A; MacNeil, Michael D

2012-01-01

Polar bears (Ursus maritimus) and brown bears (Ursus arctos) are closely related species for which extensive mitochondrial and nuclear phylogenetic comparisons have been made. We used previously published genotype data for 8 microsatellite DNA loci from 930 brown bears in 19 populations and 473 polar bears in 16 populations to compare the population genetic relationships of extant populations of the species. Genetic distances (Nei standard distance = 1.157), the proportion of private alleles (52% of alleles are not shared by the species), and Bayesian cluster analysis are consistent with morphological and life-history characteristics that distinguish polar bears and brown bears as different species with little or no gene flow among extant populations.

Bear Creek Valley Floodplain Hot Spot Removal Action Project Plan, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

1998-01-01

The Bear Creek Valley Floodplain Hot Spot Removal Action Project Plan, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee (Y/ER-301) was prepared (1) to safely, cost-effectively, and efficiently evaluate the environmental impact of solid material in the two debris areas in the context of industrial land uses (as defined in the Bear Creek Valley Feasibility Study) to support the Engineering Evaluation/Cost Assessment and (2) to evaluate, define, and implement the actions to mitigate these impacts. This work was performed under Work Breakdown Structure 1.x.01.20.01.08

The Ehrlich-Schwoebel barrier on an oxide surface: a combined Monte-Carlo and in situ scanning tunneling microscopy approach.

Science.gov (United States)

Gianfrancesco, Anthony G; Tselev, Alexander; Baddorf, Arthur P; Kalinin, Sergei V; Vasudevan, Rama K

2015-11-13

The controlled growth of epitaxial films of complex oxides requires an atomistic understanding of key parameters determining final film morphology, such as termination dependence on adatom diffusion, and height of the Ehrlich-Schwoebel (ES) barrier. Here, through an in situ scanning tunneling microscopy study of mixed-terminated La5/8Ca3/8MnO3 (LCMO) films, we image adatoms and observe pile-up at island edges. Image analysis allows determination of the population of adatoms at the edge of islands and fractions on A-site and B-site terminations. A simple Monte-Carlo model, simulating the random walk of adatoms on a sinusoidal potential landscape using Boltzmann statistics is used to reproduce the experimental data, and provides an estimate of the ES barrier as ∼0.18 ± 0.04 eV at T = 1023 K, similar to those of metal adatoms on metallic surfaces. These studies highlight the utility of in situ imaging, in combination with basic Monte-Carlo methods, in elucidating the factors which control the final film growth in complex oxides.

The Ehrlich-Schwoebel barrier on an oxide surface: a combined Monte-Carlo and in situ scanning tunneling microscopy approach

Science.gov (United States)

Gianfrancesco, Anthony G.; Tselev, Alexander; Baddorf, Arthur P.; Kalinin, Sergei V.; Vasudevan, Rama K.

2015-11-01

The controlled growth of epitaxial films of complex oxides requires an atomistic understanding of key parameters determining final film morphology, such as termination dependence on adatom diffusion, and height of the Ehrlich-Schwoebel (ES) barrier. Here, through an in situ scanning tunneling microscopy study of mixed-terminated La5/8Ca3/8MnO3 (LCMO) films, we image adatoms and observe pile-up at island edges. Image analysis allows determination of the population of adatoms at the edge of islands and fractions on A-site and B-site terminations. A simple Monte-Carlo model, simulating the random walk of adatoms on a sinusoidal potential landscape using Boltzmann statistics is used to reproduce the experimental data, and provides an estimate of the ES barrier as ˜0.18 ± 0.04 eV at T = 1023 K, similar to those of metal adatoms on metallic surfaces. These studies highlight the utility of in situ imaging, in combination with basic Monte-Carlo methods, in elucidating the factors which control the final film growth in complex oxides.

The influence of whole body 60Co-irradiation on distribution of 67Ga in tumor-bearing mice

International Nuclear Information System (INIS)

Wakao, Hiromi; Shimura, Akira; Higashi, Tomomitsu

1981-01-01

Since the initial findings that 67 Ga has a preferential affinity for soft tissue tumors, in humans numerous suggestions have been advanced for the basic mechanism involved. The effects produced by whole-body X-irradiation on the excretion and tissue distribution of 67 Ga have been reported by Swartzendruber and others. Bradley and coworkers have shown that these irradiation effects were associated with an increase in serum iron. The present investigation was undertaken in order to study the relationships between the change in the serum iron concentration and 67 Ga accumulation in the tumor and soft tissues in mice bearing Ehrlich's ascites tumor. The following results were obtained. (1) The serum iron concentration was significantly decreased between 3 and 6 hours after 10 Gy (1,000 rad) dose of whole-body 60 Co-irradiation. Subsequently, the serum iron levels were slowly elevated. (2) The uptake of 67 Ga in the tumor and soft tissues was increased if the serum iron concentration was decreased by whole-body 60 Co-irradiation during the early phase. On the contrary, if the serum iron concentration was high, the uptake of 67 Ga in the tumor was decreased. (3) The excretion of 67 Ga from the body was delayed if the serum iron concentration was decreased by whole-body 60 Co-irradiation. However, if the serum iron concentration was high, the excretion of 67 Ga from the body significantly increased. (author)

R+D works for the further development of high temperature reactors. (1) Captive bearing experiments for active magnetic bearings. (2) Captive bearing test for HTR blowers

International Nuclear Information System (INIS)

1991-01-01

When using active magnetic bearings as blower shaft bearings, blower motors and bearings must be protected against mechanical damage in case of faults (example: total electrical supply failure due to the supply cables breaking). So-called captive bearings are provided, in order to be able to shut the blowers down safely in such faults. These captive bearings are roller bearings which are additionally fitted in the area of the blower shaft bearings, to prevent mechanical contact between the blower rotor and stator. As there was little experience available for the given boundary conditions, such as - speed, - acceleration, - bearing load, - bearing dimensions, - ambient conditions, appropriate development and tests had to be carried out. It was important to determine suitable captive bearings and the necessary ambient conditions, which will make it possible to support the failures of the magnetic bearings to be expected in 40 years' operation of the reactor without damage and to meet the requirements of the captive bearings. (orig./GL) [de

EFFECT OF BEARING MACROGEOMETRY ON BEARING PERFORMANCE IN ELASTOHYDRODYNAMIC LUBRICATION

Directory of Open Access Journals (Sweden)

Emin GÜLLÜ

2000-01-01

Full Text Available During manufacturing, ideal dimension and mutual positioning of machine elements proposed in project desing can be achieved only within certain range of tolerances. These tolerances, being classified in two groups, related to micro and macro geometry of machine elements, don't have to effect the functioning of these elements. So, as for all machine elements, investigation of the effects of macro and micro tolerances for journal bearings is important. In this study, we have investigated the effect of macro geometric irregularities of journal bearings on performance characteristics. In this regard, we have studied the change of bearing performance in respect to deviation from ideal circle for an elliptic shaft with small ovality rolling in circular journal bearing.

Passive magnetic bearing configurations

Science.gov (United States)

Post, Richard F [Walnut Creek, CA

2011-01-25

A journal bearing provides vertical and radial stability to a rotor of a passive magnetic bearing system when the rotor is not rotating and when it is rotating. In the passive magnetic bearing system, the rotor has a vertical axis of rotation. Without the journal bearing, the rotor is vertically and radially unstable when stationary, and is vertically stable and radially unstable when rotating.

Affinity of 169Yb, 67Ga and 111In for malignant tumor, (1)

International Nuclear Information System (INIS)

Ando, Itsuko

1975-01-01

The tumor affinity of 169 Yb-citrate, 67 Ga-citrate and 111 In-citrate was examined by using Yoshida sarcoma-bearing rats, and the affinity of these compounds for inflammation was also tested using rats with inflammation induced by croton oil injection. In this investigation there was no great difference in uptake by the tumor tissue of these compounds, but a great difference was observed in the retention value of the blood and uptake rate in the bone. 169 Yb-citrate was cleared rapidly from the blood and was taken mostly into the bone. So the retention values in the soft tissues became very small. On the other hand, 111 In-citrate was slowly and only slightly taken into the bone from the blood, so the retention values in the soft tissue remained relatively high. 67 Ga-citrate showed the intermediate value between the bone uptake rate of 169 Yb-citrate and that of 111 In-citrate. In the following experiments, 169 Yb-citrate and 67 Ga-citrate were compared in four strains: Yoshida sarcoma, Walker carcinosarcoma 256, Sarcoma 180, and Ehrlich tumor. The uptake rate of 169 Yb in tumor tissue was much larger than that of 67 Ga in Ehrlich tumor-bearing mice, but the value of 169 Yb was slightly smaller than those of 67 Ga in Yoshida sarcoma-bearing rats, Walker carcinosarcoma 256-bearing rats and Sarcoma 180-bearing mice. Tumor to organ ratios of 169 Yb, which were most important for tumor scanning, were much larger than those of 67 Ga in all four strains except tumor to bone ratios of 169 Yb. From the above-described facts, it was shown that 169 Yb-citrate had a stronger tumor affinity than 67 Ga-citrate and that the tumor affinity of 169 Yb-citrate was similar in these four strains of tumor bearing animals. These three compounds had a relatively strong affinity with the inflammatory tissue. (auth.)

Comparison of fixed-bearing and mobile-bearing total knee arthroplasty after high tibial osteotomy.

Science.gov (United States)

Hernigou, Philippe; Huys, Maxime; Pariat, Jacques; Roubineau, François; Flouzat Lachaniette, Charles Henri; Dubory, Arnaud

2018-02-01

There is no information comparing the results of fixed-bearing total knee replacement and mobile-bearing total knee replacement in the same patients previously treated by high tibial osteotomy. The purpose was therefore to compare fixed-bearing and mobile-bearing total knee replacements in patients treated with previous high tibial osteotomy. We compared the results of 57 patients with osteoarthritis who had received a fixed-bearing prosthesis after high tibial osteotomy with the results of 41 matched patients who had received a rotating platform after high tibial osteotomy. The match was made for length of follow-up period. The mean follow-up was 17 years (range, 15-20 years). The patients were assessed clinically and radiographically. The pre-operative knee scores had no statistically significant differences between the two groups. So was the case with the intra-operative releases, blood loss, thromboembolic complications and infection rates in either group. There was significant improvement in both groups of knees, and no significant difference was observed between the groups (i.e., fixed-bearing and mobile-bearing knees) for the mean Knee Society knee clinical score (95 and 92 points, respectively), or the Knee Society knee functional score (82 and 83 points, respectively) at the latest follow-up. However, the mean post-operative knee motion was higher for the fixed-bearing group (117° versus 110°). In the fixed-bearing group, one knee was revised because of periprosthetic fracture. In the rotating platform mobile-bearing group, one knee was revised because of aseptic loosening of the tibial component. The Kaplan-Meier survivorship for revision at ten years of follow-up was 95.2% for the fixed bearing prosthesis and 91.1% for the rotating platform mobile-bearing prosthesis. Although we did manage to detect significant differences mainly in clinical and radiographic results between the two groups, we found no superiority or inferiority of the mobile-bearing

Evaluating the cement stabilization of arsenic-bearing iron wastes from drinking water treatment.

Science.gov (United States)

Clancy, Tara M; Snyder, Kathryn V; Reddy, Raghav; Lanzirotti, Antonio; Amrose, Susan E; Raskin, Lutgarde; Hayes, Kim F

2015-12-30

Cement stabilization of arsenic-bearing wastes is recommended to limit arsenic release from wastes following disposal. Such stabilization has been demonstrated to reduce the arsenic concentration in the Toxicity Characteristic Leaching Procedure (TCLP), which regulates landfill disposal of arsenic waste. However, few studies have evaluated leaching from actual wastes under conditions similar to ultimate disposal environments. In this study, land disposal in areas where flooding is likely was simulated to test arsenic release from cement stabilized arsenic-bearing iron oxide wastes. After 406 days submersed in chemically simulated rainwater, wastes. Presenting the first characterization of cement stabilized waste using μXRF, these results revealed the majority of arsenic in cement stabilized waste remained associated with iron. This distribution of arsenic differed from previous observations of calcium-arsenic solid phases when arsenic salts were stabilized with cement, illustrating that the initial waste form influences the stabilized form. Overall, cement stabilization is effective for arsenic-bearing wastes when acidic conditions can be avoided. Copyright © 2015 Elsevier B.V. All rights reserved.

Hydrodynamic sliding bearings vs. roller bearings. Segmented sliding bearings for higher rotational speed; Hydrodynamische Gleitlager versus Waelzlager. Segmentgleitlager fuer hoehere Drehzahlen

Energy Technology Data Exchange (ETDEWEB)

Hagenhoff, M.; Sauer, M. [Main-Metall-Giesserei Fritz Schorr GmbH und Co. KG, Altenglan (Germany)

2004-10-01

Hydrodynamic sliding bearings are considered only in cases when roller bearings reach their speed limits and there is no other solution. However, this view neglects the fact that there are modern, optimised sliding bearings which have more advantages over roller bearings than should be expected. Many producers of sliding bearings also have computer programs enabling them to offer customised solutions, i.e. optimal adaptation of the bearings to their specific operating conditions. (orig.) [German] Hydrodynamische Gleitlager werden oft erst dann in Betracht gezogen, wenn man an die Drehzahlgrenzen von Waelzlagern stoesst und keine andere sinnvolle Alternative mehr in Frage kommt. Dabei uebersieht man leicht, dass es moderne, optimierte Gleitlagerkonstruktionen gibt, die weitaus haeufiger ihre Staerken im Vergleich zu Waelzlagern ausspielen koennen als zunaechst vermutet. Viele Gleitlagerhersteller haben zudem heute Berechnungsprogramme zur Verfuegung, die eine optimale Anpassung der Lager an die speziellen Betriebsbedingungen erlauben. (orig.)

Genomic evidence of geographically widespread effect of gene flow from polar bears into brown bears

OpenAIRE

Cahill, James A; Stirling, Ian; Kistler, Logan; Salamzade, Rauf; Ersmark, Erik; Fulton, Tara L; Stiller, Mathias; Green, Richard E; Shapiro, Beth

2015-01-01

© 2014 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd. Polar bears are an arctic, marine adapted species that is closely related to brown bears. Genome analyses have shown that polar bears are distinct and genetically homogeneous in comparison to brown bears. However, these analyses have also revealed a remarkable episode of polar bear gene flow into the population of brown bears that colonized the Admiralty, Baranof and Chichagof islands (ABC islands) of Alaska. Here, we...

Amino Acids in the Asteroidal Water-Bearing Salt Crystals Hosted in the Zag Meteorite

Science.gov (United States)

Chan, Q. H. S.; Zolensky, M. E.; Burton, A. S.; Locke, D. R.

2016-01-01

Solid evidence of liquid water in primitive meteorites is given by the ordinary chondrites H5 Monahans (1998) and H3-6 Zag. Aqueous fluid inclusion-bearing halite (NaCl) crystals were shown to be common in Zag. These striking blue/purple crystals (Figure 1), which gained the coloration from electron-trapping in the Cl-vacancies through exposure to ionizing radiation, were determined to be over 4.0-4.7 billion years old by I-Xe dating. The halite grains are present as discrete grains within an H-chondrite matrix with no evidence for aqueous alteration that indicates a xenogenic source, possibly ancient cryovolcanism. They were proposed to be formed from the cryovolcanic plumes on icy C-type asteroids (possibly Ceres), and were transferred and incorporated into the H chondrite parent asteroid following the eruption event(s). A unique aspect of these halites is that they contain abundant solid inclusions hosted within the halites alongside the water inclusions. The solid inclusions were suggested to be entrained within the fluid erupted from the cryovolcanic event(s), and were shown to be comprised of abundant organics. Spectrofluorometric study and Raman imaging of the halites have identified macromolecular carbon and aliphatic carbon compounds. In order to investigate the type of organics present in Zag and in particular within the fluid-bearing halites, we studied for the first time the amino acid contents of a selected mineral (halite) phase in a meteorite sample.

The role of human outdoor recreation in shaping patterns of grizzly bear-black bear co-occurrence.

Directory of Open Access Journals (Sweden)

Andrew Ladle

Full Text Available Species' distributions are influenced by a combination of landscape variables and biotic interactions with other species, including people. Grizzly bears and black bears are sympatric, competing omnivores that also share habitats with human recreationists. By adapting models for multi-species occupancy analysis, we analyzed trail camera data from 192 trail camera locations in and around Jasper National Park, Canada to estimate grizzly bear and black bear occurrence and intensity of trail use. We documented (a occurrence of grizzly bears and black bears relative to habitat variables (b occurrence and intensity of use relative to competing bear species and motorised and non-motorised recreational activity, and (c temporal overlap in activity patterns among the two bear species and recreationists. Grizzly bears were spatially separated from black bears, selecting higher elevations and locations farther from roads. Both species co-occurred with motorised and non-motorised recreation, however, grizzly bears reduced their intensity of use of sites with motorised recreation present. Black bears showed higher temporal activity overlap with recreational activity than grizzly bears, however differences in bear daily activity patterns between sites with and without motorised and non-motorised recreation were not significant. Reduced intensity of use by grizzly bears of sites where motorised recreation was present is a concern given off-road recreation is becoming increasingly popular in North America, and can negatively influence grizzly bear recovery by reducing foraging opportunities near or on trails. Camera traps and multi-species occurrence models offer non-invasive methods for identifying how habitat use by animals changes relative to sympatric species, including humans. These conclusions emphasise the need for integrated land-use planning, access management, and grizzly bear conservation efforts to consider the implications of continued access for

The role of human outdoor recreation in shaping patterns of grizzly bear-black bear co-occurrence.

Science.gov (United States)

Ladle, Andrew; Steenweg, Robin; Shepherd, Brenda; Boyce, Mark S

2018-01-01

Species' distributions are influenced by a combination of landscape variables and biotic interactions with other species, including people. Grizzly bears and black bears are sympatric, competing omnivores that also share habitats with human recreationists. By adapting models for multi-species occupancy analysis, we analyzed trail camera data from 192 trail camera locations in and around Jasper National Park, Canada to estimate grizzly bear and black bear occurrence and intensity of trail use. We documented (a) occurrence of grizzly bears and black bears relative to habitat variables (b) occurrence and intensity of use relative to competing bear species and motorised and non-motorised recreational activity, and (c) temporal overlap in activity patterns among the two bear species and recreationists. Grizzly bears were spatially separated from black bears, selecting higher elevations and locations farther from roads. Both species co-occurred with motorised and non-motorised recreation, however, grizzly bears reduced their intensity of use of sites with motorised recreation present. Black bears showed higher temporal activity overlap with recreational activity than grizzly bears, however differences in bear daily activity patterns between sites with and without motorised and non-motorised recreation were not significant. Reduced intensity of use by grizzly bears of sites where motorised recreation was present is a concern given off-road recreation is becoming increasingly popular in North America, and can negatively influence grizzly bear recovery by reducing foraging opportunities near or on trails. Camera traps and multi-species occurrence models offer non-invasive methods for identifying how habitat use by animals changes relative to sympatric species, including humans. These conclusions emphasise the need for integrated land-use planning, access management, and grizzly bear conservation efforts to consider the implications of continued access for motorised

Unbalance Response Prediction for Rotors on Ball Bearings Using Speed and Load Dependent Nonlinear Bearing Stiffness

Science.gov (United States)

Fleming, David P.; Poplawski, J. V.

2003-01-01

Rolling-element bearing forces vary nonlinearly with bearing deflection. Thus an accurate rotordynamic analysis requires that bearing forces corresponding to the actual bearing deflection be utilized. For this work bearing forces were calculated by COBRA-AHS, a recently developed rolling-element bearing analysis code. Bearing stiffness was found to be a strong function of bearing deflection, with higher deflection producing markedly higher stiffness. Curves fitted to the bearing data for a range of speeds and loads were supplied to a flexible rotor unbalance response analysis. The rotordynamic analysis showed that vibration response varied nonlinearly with the amount of rotor imbalance. Moreover, the increase in stiffness as critical speeds were approached caused a large increase in rotor and bearing vibration amplitude over part of the speed range compared to the case of constant bearing stiffness. Regions of bistable operation were possible, in which the amplitude at a given speed was much larger during rotor acceleration than during deceleration. A moderate amount of damping will eliminate the bistable region, but this damping is not inherent in ball bearings.

Organic Matter in Extraterrestrial Water-Bearing Salt Crystals

Science.gov (United States)

Chan, Q. H. S.; Zolensky, M. E.; Kebukwa, Y.; Fries, M.; Steele, A.

2017-01-01

Introduction: Direct samples of early Solar System fluids are present in two thermally-metamorphosed ordinary chondrite regolith breccias (Monahans (1998) [H5] and Zag [H3-6]), which were found to contain brine-bearing halite (NaCl) crystals that have been added to the regolith of an S-type asteroid following asteroidal metamorphism [1, 2]. The brine-bearing halite grains were proposed to be formed on an icy C-type asteroids (possibly Ceres), and transferred to an S-type asteroid via cryovolcanic event(s) [3]. A unique aspect of these halites is that they contain abundant organic rich solid inclusions hosted within the halites alongside the water inclusions. Methods: We analyzed in detail the compositions of the organic solids and the amino acid content of the halite crystals with two-step laser desorption/laser ionization mass spectrometry (L(sup 2) MS), Raman spectroscopy, X-ray absorption near edge structure (XANES), nanoscale secondary ion mass spectrometry (NanoSIMS), and ultra-performance liquid chromatography fluorescence detection and quadrupole time of flight hybrid mass spectrometry (UPLC-FD/QToF-MS). Results and Discussion: The L(sup 2) MS results show signatures of low-mass polyaromatic hydro-carbons (PAHs) indicated by sequences of peaks separated by 14 atomic mass units (amu) due to successive addition of methylene (CH2) groups to the PAH skeletons [4]. Raman spectra of the micron-sized solid inclusions of the halites indicate the presence of abundant and highly variable organic matter that include a mixture of short-chain aliphatic compounds and macromolecular carbon. C-XANES analysis identified C-rich areas with peaks at 285.0 eV (aromatic C=C) and 286.6 eV (vinyl-keto C=O). However, there is no 1s-sigma* exciton peak (291.7 eV) that is indicative of the development of graphene structure [5], which suggests the organics were synthesized cold. Na-noSIMS analyses show C-rich and N-rich areas that exhibit similar isotopic values with that of the IOM in

Optimizing the dosing schedule of l-asparaginase improves its anti-tumor activity in breast tumor-bearing mice

Directory of Open Access Journals (Sweden)

Shoya Shiromizu

2018-04-01

Full Text Available Proliferation of acute lymphoblastic leukemic cells is nutritionally dependent on the external supply of asparagine. l-asparaginase, an enzyme hydrolyzing l-asparagine in blood, is used for treatment of acute lymphoblastic leukemic and other related blood cancers. Although previous studies demonstrated that l-asparaginase suppresses the proliferation of cultured solid tumor cells, it remains unclear whether this enzyme prevents the growth of solid tumors in vivo. In this study, we demonstrated the importance of optimizing dosing schedules for the anti-tumor activity of l-asparaginase in 4T1 breast tumor-bearing mice. Cultures of several types of murine solid tumor cells were dependent on the external supply of asparagine. Among them, we selected murine 4T1 breast cancer cells and implanted them into BALB/c female mice kept under standardized light/dark cycle conditions. The growth of 4T1 tumor cells implanted in mice was significantly suppressed by intravenous administration of l-asparaginase during the light phase, whereas its administration during the dark phase failed to show significant anti-tumor activity. Decreases in plasma asparagine levels due to the administration of l-asparaginase were closely related to the dosing time-dependency of its anti-tumor effects. These results suggest that the anti-tumor efficacy of l-asparaginase in breast tumor-bearing mice is improved by optimizing the dosing schedule. Keywords: l-asparaginase, Asparagine, Solid tumor, Chrono-pharmacotherapy

Local Attitudes towards Bear Management after Illegal Feeding and Problem Bear Activity

Directory of Open Access Journals (Sweden)

David Fraser

2013-09-01

Full Text Available The “pot bears” received international media attention in 2010 after police discovered the intentional feeding of over 20 black bears during the investigation of an alleged marijuana-growing operation in Christina Lake, British Columbia, Canada. A two-phase random digit dialing survey of the community was conducted in 2011 to understand local perspectives on bear policy and management, before and after a summer of problem bear activity and government interventions. Of the 159 households surveyed in February 2011, most had neutral or positive attitudes towards bears in general, and supported the initial decision to feed the food-conditioned bears until the autumn hibernation. In contrast to wildlife experts however, most participants supported relocating the problem bears, or allowing them to remain in the area, ahead of killing; in part this arose from notions of fairness despite the acknowledged problems of relocation. Most locals were aware of the years of feeding but did not report it, evidently failing to see it as a serious form of harm, even after many bears had been killed. This underscores the importance of preventive action on wildlife feeding and the need to narrow the gap between public and expert opinion on the likely effects of relocation versus killing.

Bearing construction for refrigeration compresssor

Science.gov (United States)

Middleton, Marc G.; Nelson, Richard T.

1988-01-01

A hermetic refrigeration compressor has a cylinder block and a crankshaft rotatable about a vertical axis to reciprocate a piston in a cylinder on the cylinder block. A separate bearing housing is secured to the central portion of the cylinder block and extends vertically along the crankshaft, where it carries a pair of roller bearings to journal the crankshaft. The crankshaft has a radially extending flange which is journaled by a thrust-type roller bearing above the bearing housing to absorb the vertical forces on the crankshaft so that all three of the roller bearings are between the crankshaft and the bearing housing to maintain and control the close tolerances required by such bearings.

A semi-analytical bearing model considering outer race flexibility for model based bearing load monitoring

Science.gov (United States)

Kerst, Stijn; Shyrokau, Barys; Holweg, Edward

2018-05-01

This paper proposes a novel semi-analytical bearing model addressing flexibility of the bearing outer race structure. It furthermore presents the application of this model in a bearing load condition monitoring approach. The bearing model is developed as current computational low cost bearing models fail to provide an accurate description of the more and more common flexible size and weight optimized bearing designs due to their assumptions of rigidity. In the proposed bearing model raceway flexibility is described by the use of static deformation shapes. The excitation of the deformation shapes is calculated based on the modelled rolling element loads and a Fourier series based compliance approximation. The resulting model is computational low cost and provides an accurate description of the rolling element loads for flexible outer raceway structures. The latter is validated by a simulation-based comparison study with a well-established bearing simulation software tool. An experimental study finally shows the potential of the proposed model in a bearing load monitoring approach.

Xenoestrogenic and dioxin-like activity in blood of East Greenland polar bears (Ursus maritimus).

Science.gov (United States)

Erdmann, Simon E; Dietz, Rune; Sonne, Christian; Bechshøft, Thea Ø; Vorkamp, Katrin; Letcher, Robert J; Long, Manhai; Bonefeld-Jørgensen, Eva C

2013-07-01

The aims of the project were to (i) extract the lipophilic persistent organic pollutants (POPs) from the blood of 99 East Greenland polar bears and assess the combined mixture effect on the estrogen receptor (ER) and the aryl hydrocarbon receptor (AhR) mediated transactivity; (ii) To evaluate whether the receptor transactivities were associated with selected POP markers, and (iii) compare the receptor transactivities in polar bears with earlier studies on Greenlandic Inuit. Lipophilic POPs were extracted using a combination of solid-phase extraction (SPE) and high performance liquid chromatography (HPLC). ER mediated transactivity was determined using the ER luciferase reporter MVLN cell assay. The extracts were tested alone (XER) and together with 17β-estradiol (E2) as a physiological mimic (XERcomp). Dioxins and dioxin-like (DL) compounds were extracted by a combination of SPE and the Supelco Dioxin Prep System®. AhR mediated dioxin-like transactivity was determined using the AhR luciferase reporter Hepa 1.12cR cell assay. Agonistic ER transactivity was elicited by 19% of the samples, and a further increased E2 induced ER response was found for 52%, whereas 17% antagonized the E2 induced ER response. Positive correlations were found in subadult bears between XER and several POP biomarkers. XER and XERcomp correlated positively to each other. A total of 91% of the polar bear blood extracts elicited agonistic AhR transactivity. The AhR-TCDD equivalent (AhR-TEQ) median levels were higher among adult bears compared to subadult bears, but not significantly. Copyright © 2013 Elsevier Ltd. All rights reserved.

Binding studies of the antitumoral radiopharmaceutical 125I-Crotoxin to Ehrlich ascites tumor cells

International Nuclear Information System (INIS)

Silveira, Marina B.; Santos, Raquel G. dos; Dias, Consuelo L. Fortes; Cassali, Geovanni D.

2009-01-01

The development of tools for functional diagnostic imaging is mainly based on radiopharmaceuticals that specifically target membrane receptors. Crotoxin (Crtx), a polypeptide isolated from Crotalus durissus terrificus venom, has been shown to have an antitumoral activity and is a promising bioactive tracer for tumor detection. More specific radiopharmaceuticals are being studied to complement the techniques applied in the conventional medicine against breast cancer, the most frequent cause of death from malignant disease in women. Crtx's effect has been shown to be related with the overexpression of epidermal growth factor receptor (EGFR), present in high levels in 30 to 60% of breast tumor cells. Our objective was to evaluate Crtx as a tracer for cancer diagnosis, investigating its properties as an EGFR-targeting agent. Ehrlich ascites tumor cells (EAT cells) were used due to its origin and similar characteristics to breast tumor cells, specially the presence of EGFR. Crtx was labeled with 125I and binding experiments were performed. To evaluate the specific binding in vitro of Crtx, competition binding assay was carried out in the presence of increasing concentrations of non-labelled crotoxin and epidermal growth factor (EGF). Specific binding of 125I-Crtx to EAT cells was determined and the binding was considered saturable, with approximately 70% of specificity, high affinity (Kd = 19.7 nM) and IC50 = 1.6 x 10-11 M. Our results indicate that Crtx's interaction with EAT cells is partially related with EGFR and increases the biotechnological potential of Crtx as a template for radiopharmaceutical design for cancer diagnosis. (author)

Binding studies of the antitumoral radiopharmaceutical 125I-Crotoxin to Ehrlich ascites tumor cells

Energy Technology Data Exchange (ETDEWEB)

Silveira, Marina B.; Santos, Raquel G. dos [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Dias, Consuelo L. Fortes [Fundacao Ezequiel Dias (FUNED), Belo Horizonte, MG (Brazil)], e-mail: consuelo@pq.cnpq.br; Cassali, Geovanni D. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Lab. de Patologia Comparada], e-mail: cassalig@icb.ufmg.br

2009-07-01

The development of tools for functional diagnostic imaging is mainly based on radiopharmaceuticals that specifically target membrane receptors. Crotoxin (Crtx), a polypeptide isolated from Crotalus durissus terrificus venom, has been shown to have an antitumoral activity and is a promising bioactive tracer for tumor detection. More specific radiopharmaceuticals are being studied to complement the techniques applied in the conventional medicine against breast cancer, the most frequent cause of death from malignant disease in women. Crtx's effect has been shown to be related with the overexpression of epidermal growth factor receptor (EGFR), present in high levels in 30 to 60% of breast tumor cells. Our objective was to evaluate Crtx as a tracer for cancer diagnosis, investigating its properties as an EGFR-targeting agent. Ehrlich ascites tumor cells (EAT cells) were used due to its origin and similar characteristics to breast tumor cells, specially the presence of EGFR. Crtx was labeled with 125I and binding experiments were performed. To evaluate the specific binding in vitro of Crtx, competition binding assay was carried out in the presence of increasing concentrations of non-labelled crotoxin and epidermal growth factor (EGF). Specific binding of 125I-Crtx to EAT cells was determined and the binding was considered saturable, with approximately 70% of specificity, high affinity (Kd = 19.7 nM) and IC50 = 1.6 x 10-11 M. Our results indicate that Crtx's interaction with EAT cells is partially related with EGFR and increases the biotechnological potential of Crtx as a template for radiopharmaceutical design for cancer diagnosis. (author)

Ultrastructural changes produced in Ehrlich ascites carcinoma cells by ultraviolet-visible radiation in the presence of melanins

Energy Technology Data Exchange (ETDEWEB)

Lea, P.J.; Pawlowski, A.; Persad, S.D.; Menon, I.A.; Haberman, H.F.

1988-01-01

Irradiation of Ehrlich ascites carcinoma (EAC) cells in the presence of pheomelanin, i.e., red hair melanin (RHM), has been reported to produce extensive cell lysis. Irradiation in the presence of eumelanin, i.e., black hair melanin (BHM), or irradiation in the absence of either type of melanin did not produce this effect. We observed that RHM particles penetrated the cell membrane without apparent structural damage to the cell or the cell membrane. Irradiation of the cells in the absence of melanin did not produce any changes in the ultrastructure of the cells. Incubation of the cells in the dark in the presence of RHM produced only minor structural, mainly cytoplasmic changes. Irradiation of the cells in the presence of RHM produced extensive ultrastructural changes prior to complete cell lysis; these changes were more severe than the effects of incubation of the cells in the dark in the presence of RHM. When the cells incubated in the dark or irradiated in the presence of latex particles or either one of the eumelanins particles, viz. BHM or synthetic dopa melanin, these particles did not penetrate into the cells or produce any ultrastructural changes. These particles were in fact not even ingested by the cells.

EFFECT OF CLEARANCE THE BALL BEARINGS ON INCORRECT WORK OF THREE-SUPORT BEARING SHAFT

OpenAIRE

Jarosław KACZOR

2014-01-01

Durability deep groove ball bearings depends on factors (called attributes) design, technological and operational. Among the design features one of the most important is play in the bearings. Polish Norm shows five groups of looseness in the bearings, in which the play range from 0 to 105 microns. Manufacturers of rolling bearings they only play group, which has a bearing data, without giving the exact value of the slack. Aim of this study is to determine how it affects the play in the bea...

Study of solid phase kinetics during cyanidation using the 198 Au radioactive tracer

International Nuclear Information System (INIS)

Barbus, A.; Pop, I.I.; Gaspar, E.

1995-01-01

During cyanidation, the various gold bearing pyrite sorts exhibit different behaviour, that sometimes cause increased cyanidation times influencing the reagent and power consumption, in the same time generating fluctuations in the recovery efficiencies. The introduction of the 198 Au radioactive tracer into the cyanidation circuit enabled us to follow several parameters of the cyanidation kinetics: the average residence time of the gold bearing pyrite in the technological equipment, information about the homogenization process, dispersion of solids and gold dissolution efficiency on each technological stage. (author)

Study of crotoxin mechanism of action to mammary carcinomas and evaluation of its potential as a radiopharmaceutical; Estudo do mecanismo de acao da crotoxina em tumores mamarios e avaliacao do seu potenctial radiofarmaceutico

Energy Technology Data Exchange (ETDEWEB)

Silveira, Marina Bicalho

2010-07-01

Crotoxin, the main component of Crotalus durissus terrificus snake venom, has been studied since 1938. It is a natural polypeptidic complex with pharmacological potential because of its antitumoral properties which has attracted great interest for diagnosis and therapy of oncological diseases. However, Crotoxin mechanism of action and sites of specific interaction on tumor cells are still misunderstood. Breast cancer is the second most frequent type in the world and the most common cancer in women. About 30 to 60% of mammary tumors overexpress epidermal growth factor receptor (EGFR), a transmembrane protein related to cell proliferation. Since literature has reported that Crotoxin antitumoral effect is more potent on cells with EGFR overexpression the objectives of this work were to evaluate Crotoxin cytotoxic effects on mammary tumor cells human breast carcinoma (MCF-7) and Ehrlich tumor cells (murine ascitics carcinoma), and to investigate the specific molecular interaction of Crotoxin on Ehrlich tumor cells. Initially, Crotoxin was radiolabelled with iodine-125 ({sup 125}I-Crotoxin) and iodine-131 ({sup 131}I-Crotoxin). Saturation and competition assay were carried out to characterize Crotoxin in vitro interaction; Crotoxin biodistribution studies and singlephoton emission computed tomography (SPECT) of mice bearing Ehrlich tumor have been evaluated to describe in vivo interaction. Our results showed that Crotoxin presented cytotoxic effect against Ehrlich with DL{sub 50} in vitro (concentration of compound which is lethal for 50% of cells) of about one micromolar, but did not present significant effect against MCF-7. Morphological alterations characteristic of apoptosis suggests programmed cell death. {sup 125}I-Crotoxin interaction with Ehrlich tumor cells was saturable with approximately 70% specificity, and presented K{sub d}=24.98 nmol/L and B{sub max}=16,570 sites/cell for low affinity binding sites and K{sub d}=0.06 nmol/L and B{sub max}=210 sites

Bearing restoration by grinding

Science.gov (United States)

Hanau, H.; Parker, R. J.; Zaretsky, E. V.; Chen, S. M.; Bull, H. L.

1976-01-01

A joint program was undertaken by the NASA Lewis Research Center and the Army Aviation Systems Command to restore by grinding those rolling-element bearings which are currently being discarded at aircraft engine and transmission overhaul. Three bearing types were selected from the UH-1 helicopter engine (T-53) and transmission for the pilot program. No bearing failures occurred related to the restoration by grinding process. The risk and cost of a bearing restoration by grinding programs was analyzed. A microeconomic impact analysis was performed.

Impact of Fixed-Bearing and Mobile-Bearing Tibial Insert in Unicondylar Knee Arthroplasty

Directory of Open Access Journals (Sweden)

Mehmet Faruk Çatma

2016-06-01

Full Text Available INTRODUCTION: The aim of the study is to investigate the impact of fixed or mobile-bearing tibial inserts on patellofemoral arthrosis and evaluate which one to be preferred for patients with patellofemoral arthrosis. METHODS: Operated in our clinic between January 2009 and February 2013, 33 with patellofemoral arthritis together with anteromedial compartment arthritis were included in the study. Patellofemoral joints of patients were evaluated according to the scoring system defined by Fulkerson-Shea. RESULTS: Unicondylar knee arthroplasty with fixed-bearing tibial insertsand 22 (66,6% (male: 3, female: 19 and unicondylar knee arthroplasty with mobile-bearing tibial inserts 11 (33,9 % (male: 2, female: 9 were implanted.Average knee flexion was found to be 116,5 (100-135 degrees in 22 patients with mobile-bearing tibial inserts, and 114,5 (95-135 in 11 patients with fixed-bearing tibial inserts. DISCUSSION AND CONCLUSION: Patellofemoral arthrosis is an important factor for unicondylar knee arthroplasty prognosis and one of the determinants of patient satisfaction. Significantly less patellofemoral complaints were seen with UKA with fixed-bearing tibial insert compared to mobile-bearing tibial insert.

Influences of preload on the friction and wear properties of high-speed instrument angular contact ball bearings

Directory of Open Access Journals (Sweden)

Tao ZHANG

2018-03-01

Full Text Available For starved-oil or solid lubrication of high-speed instrument angular contact ball bearings, friction heating and wear are the main reasons of bearing failures. This paper presents a dynamic wear simulation model to investigate the impacts of different preload methods and the changes of preload caused by wear on bearing wear life. The integral value QV of stress and sliding velocity in the contact ellipses between a ball and the inner and outer races determines friction heating and wear. The changes of QV with the friction coefficient and the wear volume under constant-force preload and fixed-position preload are analyzed. Results show that under the same initial preload, the QV decreases with an increase of the friction coefficient for both preload methods, and the latter is slightly larger. The wear of the ball and the race is equivalent to the ball diameter reduction. The QV of constant-force preload is almost not changed with a decrease of the ball diameter, but for fixed-position preload, the value decreases firstly and then increases substantially due to insufficient preload, and slipping occurs, the ball diameter is reduced by 0.025%, while the preload is reduced by 60.33%. An estimation of the bearing wear life under different preload methods requires a consideration of the changes in the wear rate of bearing parts. Keywords: Angular contact ball bearings, Bearing life, Dynamic model, Preload methods, Wear rate

Climate Drives Polar Bear Origins

Science.gov (United States)

In their provocative analysis of northern bears (“Nuclear genomic sequences reveal that polar bears are an old and distinct bear lineage,” Reports, 20 April, p. 344), F. Hailer et al. use independent nuclear loci to show that polar bears originated during the middle Pleistocene, rather than during t...

Tribological performance of hard carbon coatings on 440C bearing steel

Energy Technology Data Exchange (ETDEWEB)

Kustas, F M; Misra, M S; Shepard, D F; Froechtenigt, J F [Martin Marietta Astronautics Group, Denver, CO (United States)

1991-11-01

Hard carbon coatings such as amorphous carbon, diamond and diamond-like carbon have received considerable attention for tribological applications owing to their high hardness, high modulus and desirable surface properties. Unfortunately, most of the deposition techniques induce high substrate temperatures that would temper traditional bearing steels and reduce the substrate load-carrying capability. Therefore, to effectively use these desirable coatings, a lower temperature deposition technique is required. Ion beam deposition can provide essentially ambient temperature conditions, accurate control of process parameters and good coating-substrate adhesion. To use these attributes, a test program was initiated to deposit mass-analyzed, high purity C{sup +} and CH{sub 4}{sup +} ions on molybdenum and 440C bearing steel for subsequent characterization by Raman spectroscopy and friction-wear tests. Results for a coating deposited from a carbon monoxide source showed an amorphous carbon-microcrystalline graphtie structure which exhibited very high microhardness and a three fold reduction in coefficient of friction for unlubricated tests compared to untreated 440C steel. In addition, incrementally increasing the applied load (by up to a factor of 5) resulted in progressively lower coefficients of friction, which conforms to solid lubrication theory. End-of-travel wear debris and some limited coating delamination were observed within thinner areas of the coating. Therefore an amorphous carbon-graphite coating applied to 440C steel at ambient temperature exhibits solid lubricating film characteristics with high load-carrying capability. (orig.).

Ancestral polymorphisms and sex-biased migration shaped the demographic history of brown bears and polar bears.

Directory of Open Access Journals (Sweden)

Shigeki Nakagome

Full Text Available Recent studies have reported discordant gene trees in the evolution of brown bears and polar bears. Genealogical histories are different among independent nuclear loci and between biparentally inherited autosomal DNA (aDNA and matrilineal mitochondrial DNA (mtDNA. Based on multi-locus genomic sequences from aDNA and mtDNA, we inferred the population demography of brown and polar bears and found that brown bears have 6 times (aDNA or more than 14 times (mtDNA larger population sizes than polar bears and that polar bear lineage is derived from within brown bear diversity. In brown bears, the effective population size ratio of mtDNA to aDNA was at least 0.62, which deviated from the expected value of 0.25, suggesting matriarchal population due to female philopatry and male-biased migration. These results emphasize that ancestral polymorphisms and sex-biased migration may have contributed to conflicting branching patterns in brown and polar bears across aDNA genes and mtDNA.

Ancestral polymorphisms and sex-biased migration shaped the demographic history of brown bears and polar bears.

Science.gov (United States)

Nakagome, Shigeki; Mano, Shuhei; Hasegawa, Masami

2013-01-01

Recent studies have reported discordant gene trees in the evolution of brown bears and polar bears. Genealogical histories are different among independent nuclear loci and between biparentally inherited autosomal DNA (aDNA) and matrilineal mitochondrial DNA (mtDNA). Based on multi-locus genomic sequences from aDNA and mtDNA, we inferred the population demography of brown and polar bears and found that brown bears have 6 times (aDNA) or more than 14 times (mtDNA) larger population sizes than polar bears and that polar bear lineage is derived from within brown bear diversity. In brown bears, the effective population size ratio of mtDNA to aDNA was at least 0.62, which deviated from the expected value of 0.25, suggesting matriarchal population due to female philopatry and male-biased migration. These results emphasize that ancestral polymorphisms and sex-biased migration may have contributed to conflicting branching patterns in brown and polar bears across aDNA genes and mtDNA.

Bearing for liquid metal pump

International Nuclear Information System (INIS)

Dickinson, R.J.; Pennell, W.E.; Wasko, J.

1984-01-01

A liquid metal pump bearing support comprises a series of tangentially oriented spokes that connect the bearing cylinder to the pump internals structure. The spokes may be arranged in a plurality of planes extending from the bearing cylinder to the pump internals with the spokes in one plane being arranged alternately with those in the next plane. The bearing support structure provides the pump with sufficient lateral support for the bearing structure together with the capability of accommodating differential thermal expansion without adversely affecting pump performance

Ultra-precision bearings

CERN Document Server

Wardle, F

2015-01-01

Ultra-precision bearings can achieve extreme accuracy of rotation, making them ideal for use in numerous applications across a variety of fields, including hard disk drives, roundness measuring machines and optical scanners. Ultraprecision Bearings provides a detailed review of the different types of bearing and their properties, as well as an analysis of the factors that influence motion error, stiffness and damping. Following an introduction to basic principles of motion error, each chapter of the book is then devoted to the basic principles and properties of a specific type of bearin

Watchable Wildlife: The Black Bear

Science.gov (United States)

Lynn L. Rogers

1992-01-01

Black bears are the bears people most often encounter. Black bears live in forests over much of North America, unlike grizzlies that live only in Alaska, northern and western Canada, and the northern Rocky Mountains. This brochure presents the latest information on black bear life and how this species responds to an ever-increasing number of campers, hikers, and...

Active magnetic bearings used as exciters for rolling element bearing outer race defect diagnosis.

Science.gov (United States)

Xu, Yuanping; Di, Long; Zhou, Jin; Jin, Chaowu; Guo, Qintao

2016-03-01

The active health monitoring of rotordynamic systems in the presence of bearing outer race defect is considered in this paper. The shaft is assumed to be supported by conventional mechanical bearings and an active magnetic bearing (AMB) is used in the mid of the shaft location as an exciter to apply electromagnetic force to the system. We investigate a nonlinear bearing-pedestal system model with the outer race defect under the electromagnetic force. The nonlinear differential equations are integrated using the fourth-order Runge-Kutta algorithm. The simulation and experimental results show that the characteristic signal of outer race incipient defect is significantly amplified under the electromagnetic force through the AMBs, which is helpful to improve the diagnosis accuracy of rolling element bearing׳s incipient outer race defect. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

Genomic Evidence of Widespread Admixture from Polar Bears into Brown Bears during the Last Ice Age.

Science.gov (United States)

Cahill, James A; Heintzman, Peter D; Harris, Kelley; Teasdale, Matthew D; Kapp, Joshua; Soares, Andre E R; Stirling, Ian; Bradley, Daniel; Edwards, Ceiridwen J; Graim, Kiley; Kisleika, Aliaksandr A; Malev, Alexander V; Monaghan, Nigel; Green, Richard E; Shapiro, Beth

2018-05-01

Recent genomic analyses have provided substantial evidence for past periods of gene flow from polar bears (Ursus maritimus) into Alaskan brown bears (Ursus arctos), with some analyses suggesting a link between climate change and genomic introgression. However, because it has mainly been possible to sample bears from the present day, the timing, frequency, and evolutionary significance of this admixture remains unknown. Here, we analyze genomic DNA from three additional and geographically distinct brown bear populations, including two that lived temporally close to the peak of the last ice age. We find evidence of admixture in all three populations, suggesting that admixture between these species has been common in their recent evolutionary history. In addition, analyses of ten fossil bears from the now-extinct Irish population indicate that admixture peaked during the last ice age, whereas brown bear and polar bear ranges overlapped. Following this peak, the proportion of polar bear ancestry in Irish brown bears declined rapidly until their extinction. Our results support a model in which ice age climate change created geographically widespread conditions conducive to admixture between polar bears and brown bears, as is again occurring today. We postulate that this model will be informative for many admixing species pairs impacted by climate change. Our results highlight the power of paleogenomics to reveal patterns of evolutionary change that are otherwise masked in contemporary data.

Scaling laws for radial foil bearings

Science.gov (United States)

Honavara Prasad, Srikanth

The effects of fluid pressurization, structural deformation of the compliant members and heat generation in foil bearings make the design and analysis of foil bearings very complicated. The complex fluid-structural-thermal interactions in foil bearings also make modeling efforts challenging because these phenomena are governed by highly non-linear partial differential equations. Consequently, comparison of various bearing designs require detailed calculation of the flow fields (velocities, pressures), bump deflections (structural compliance) and heat transfer phenomena (viscous dissipation in the fluid, frictional heating, temperature profile etc.,) resulting in extensive computational effort (time/hardware). To obviate rigorous computations and aid in feasibility assessments of foil bearings of various sizes, NASA developed the "rule of thumb" design guidelines for estimation of journal bearing load capacity. The guidelines are based on extensive experimental data. The goal of the current work is the development of scaling laws for radial foil bearings to establish an analytical "rule of thumb" for bearing clearance and bump stiffness. The use of scale invariant Reynolds equation and experimentally observed NASA "rule of thumb" yield scale factors which can be deduced from first principles. Power-law relationships between: a. Bearing clearance and bearing radius, and b. bump stiffness and bearing radius, are obtained. The clearance and bump stiffness values obtained from scaling laws are used as inputs for Orbit simulation to study various cases. As the clearance of the bearing reaches the dimensions of the material surface roughness, asperity contact breaks the fluid film which results in wear. Similarly, as the rotor diameter increases (requiring larger bearing diameters), the load capacity of the fluid film should increase to prevent dry rubbing. This imposes limits on the size of the rotor diameter and consequently bearing diameter. Therefore, this thesis aims

Bears and pipeline construction in Alaska

Energy Technology Data Exchange (ETDEWEB)

Follmann, E.H.; Hechtel, J.L. (Univ. of Alaska Fairbanks, AK (USA))

1990-06-01

Serious problems were encountered with bears during construction of the 1274-km trans-Alaska oil pipeline between Prudhoe Bay and Valdez. This multi-billion-dollar project traversed both black bear (Ursus americanus Pallas) and grizzly bear (U. arctos L.) habitat throughtout its entire length. Plans for dealing with anticipated problems with bears were often inadequate. Most (71%) problems occurred north of the Yukon River in a previously roadless wilderness where inadequate refuse disposal and widespread animal feeding created dangerous situations. Of the 192 officially reported bear problems associated with the Trans-Alaska Pipeline System (TAPS) (1971-1979), about 65% involved the presence of bears in camps or dumps, 13% the feeding of bears on garbage or handouts, 10% property damage or economic loss, 7% bears under and in buildings, and only 5% charges by bears. Remarkably, no bear-related injuries were reported, suggesting that bears became accustomed to people and did not regard them as a threat. Following construction of the TAPS there have been proposals for pipelines to transport natural gas from Prudhoe Bay to southern and Pacific-rim markets. Based on past experience, some animal control measures were developed during the planning phase for the authorized gas pipeline route in Alaska. Fences installed around 100-person survey camps were found to be effective in deterring bears in two traditionally troublesome areas. 16 refs., 7 figs., 1 tab.

Computational design of rolling bearings

CERN Document Server

Nguyen-Schäfer, Hung

2016-01-01

This book comprehensively presents the computational design of rolling bearings dealing with many interdisciplinary difficult working fields. They encompass elastohydrodynamics (EHD), Hertzian contact theory, oil-film thickness in elastohydrodynamic lubrication (EHL), bearing dynamics, tribology of surface textures, fatigue failure mechanisms, fatigue lifetimes of rolling bearings and lubricating greases, Weibull distribution, rotor balancing, and airborne noises (NVH) in the rolling bearings. Furthermore, the readers are provided with hands-on essential formulas based on the up-to-date DIN ISO norms and helpful examples for computational design of rolling bearings. The topics are intended for undergraduate and graduate students in mechanical and material engineering, research scientists, and practicing engineers who want to understand the interactions between these working fields and to know how to design the rolling bearings for automotive industry and many other industries.

The use of double-decker catcher bearing with face-to-face installed inner layer bearings

Science.gov (United States)

Zhu, Yi-Li; Zheng, Zhong-Qiao

2017-07-01

In active magnetic bearing (AMB) system, the catcher bearings (CB) are indispensable to temporarily support the rotor from directly impacting the stators. In most cases, traditional CB cannot bear the ultra-high speed, vibrations and impacts after a rotor drop event. To address the shortcomings, a double-decker ball bearing (DDBB) with inner two face-to-face angular contact ball bearings are proposed to be used as CB in an AMB system, and the dynamic response of the rotor after a rotor drop event is experimentally analyzed. The results indicate that using a DDBB as a CB helps to reduce the following collision forces after a rotor drop. Larger ball initial contact angles and smaller pre-load force on the inner layer bearings, larger radial clearance of the outer layer bearing and choosing AISI 10AISI 1045 steel which has a larger density for the adapter ring can effectively reduce the maximum impact force after a rotor drop event.

Polar bears, Ursus maritimus

Science.gov (United States)

Rode, Karyn D.; Stirling, Ian

2017-01-01

Polar bears are the largest of the eight species of bears found worldwide and are covered in a pigment-free fur giving them the appearance of being white. They are the most carnivorous of bear species consuming a high-fat diet, primarily of ice-associated seals and other marine mammals. They range throughout the circumpolar Arctic to the southernmost extent of seasonal pack ice.

Acoustic Emission Monitoring of Incipient in Journal Bearings - Part I : Detectability and measurement for bearing damages

International Nuclear Information System (INIS)

Yoon, Dong Jin; Kwon, Oh Yang; Chung, Min Hwa; Kim, Kyung Woong

1994-01-01

In contrast to the machinery using rolling element bearings, systems with journal bearings generally operate in large scale and under severe loading condition such as steam generator turbines and internal combustion engines. Failure of the bearings in these machinery can result in the system breakdown. To avoid the time consuming repair and considerable economic loss, the detection of incipient failure in journal bearings becomes very important. In this experimental approach, acoustic emission monitoring is applied to the detection of incipient failure caused by several types of abnormal operating condition most probable in the journal bearing systems. It has been known that the intervention of foreign materials, insufficient lubrication and misassembly etc. are principal factors to cause bearing failure and distress. The experiment was conducted under such designed conditions as hard particles in the lubrication layer, insufficient lubrication, and metallic contact in the simulated journal bearing system. The results showed that acoustic emission could be an effective tool to detect the incipient failure in journal bearings

Migration and clinical outcome of mobile-bearing versus fixed-bearing single-radius total knee arthroplasty.

Science.gov (United States)

Van Hamersveld, Koen T; Marang-Van De Mheen, Perla J; Van Der Heide, Huub J L; Van Der Linden-Van Der Zwaag, Henrica M J; Valstar, Edward R; Nelissen, Rob G H H

2018-04-01

Background and purpose - Mobile-bearing total knee prostheses (TKPs) were developed in the 1970s in an attempt to increase function and improve implant longevity. However, modern fixed-bearing designs like the single-radius TKP may provide similar advantages. We compared tibial component migration measured with radiostereometric analysis (RSA) and clinical outcome of otherwise similarly designed cemented fixed-bearing and mobile-bearing single-radius TKPs. Patients and methods - RSA measurements and clinical scores were assessed in 46 randomized patients at baseline, 6 months, 1 year, and annually thereafter up to 6 years postoperatively. A linear mixed-effects model was used to analyze the repeated measurements. Results - Both groups showed comparable migration (p = 0.3), with a mean migration at 6-year follow-up of 0.90 mm (95% CI 0.49-1.41) for the fixed-bearing group compared with 1.22 mm (95% CI 0.75-1.80) for the mobile-bearing group. Clinical outcomes were similar between groups. 1 fixed-bearing knee was revised for aseptic loosening after 6 years and 2 knees (1 in each group) were revised for late infection. 2 knees (1 in each group) were suspected for loosening due to excessive migration. Another mobile-bearing knee was revised after an insert dislocation due to failure of the locking mechanism 6 weeks postoperatively, after which study inclusion was preliminary terminated. Interpretation - Fixed-bearing and mobile-bearing single-radius TKPs showed similar migration. The latter may, however, expose patients to more complex surgical techniques and risks such as insert dislocations inherent to this rotating-platform design.

Cell swelling activates K⁺ and Cl^- channels as well as nonselective, stretch-activated cation channels in ehrlich ascites tumor cells

DEFF Research Database (Denmark)

Christensen, Ove; Hoffmann, Else Kay

1992-01-01

Cell-attached patch-clamp recordings from Ehrlich ascites tumor cells reveal nonselective cation channels which are activated by mechanical deformation of the membrane. These channels are seen when suction is applied to the patch pipette or after osmotic cell swelling. The channel activation does...... system. In isolated insideout patches a Ca2+-dependent, inwardly rectifying K+ channel is demonstrated. The single-channel conductance recorded with symmetrical 150 mm K+ solutions is for inward current estimated at 40 pS and for outward current at 15 pS. Activation of the K+ channel takes place after...... by membrane stretch (suction). The time-averaged number of open K+ channels during regulatory volume decrease (RVD) can be estimated at 40 per cell. The number of open K+ channels following addition of Ca2+ plus ionophore A23187 was estimated at 250 per cell. Concurrent activation in cell-attached patches...

Inducible Protective Processes in Animal Systems XIII: Comparative Analysis of Induction of Adaptive Response by EMS and MMS in Ehrlich Ascites Carcinoma Cells

Directory of Open Access Journals (Sweden)

Periyapatna Vishwaprakash Mahadimane

2014-01-01

Full Text Available In order to investigate the presence of adaptive response in cancerous cells, two monofunctional alkylating agents, namely, ethyl methanesulfonate (EMS and methyl methanesulfonate (MMS, were employed to treat Ehrlich ascites carcinoma (EAC cells in vivo. Conditioning dose of 80 mg/kg body weight of EMS or 50 mg/kg body weight of MMS and challenging dose of 240 mg/kg body weight of EMS or 150 mg/kg body weight of MMS were selected by pilot toxicity studies. Conditioned EAC cells when challenged after 8 h time lag resulted in significant reduction in chromosomal aberrations compared to challenging dose of respective agents. As has been proved in earlier studies with normal organisms, even in cancerous cells (EAC, there is presence of adaptive response to methylating and ethylating agents. Furthermore, it is also interesting to note in the present studies that the methylating agent, MMS, is a stronger inducer of the adaptive response than the ethylating agent, EMS.

Inducible Protective Processes in Animal Systems XIII: Comparative Analysis of Induction of Adaptive Response by EMS and MMS in Ehrlich Ascites Carcinoma Cells.

Science.gov (United States)

Mahadimane, Periyapatna Vishwaprakash; Vasudev, Venkateshaiah

2014-01-01

In order to investigate the presence of adaptive response in cancerous cells, two monofunctional alkylating agents, namely, ethyl methanesulfonate (EMS) and methyl methanesulfonate (MMS), were employed to treat Ehrlich ascites carcinoma (EAC) cells in vivo. Conditioning dose of 80 mg/kg body weight of EMS or 50 mg/kg body weight of MMS and challenging dose of 240 mg/kg body weight of EMS or 150 mg/kg body weight of MMS were selected by pilot toxicity studies. Conditioned EAC cells when challenged after 8 h time lag resulted in significant reduction in chromosomal aberrations compared to challenging dose of respective agents. As has been proved in earlier studies with normal organisms, even in cancerous cells (EAC), there is presence of adaptive response to methylating and ethylating agents. Furthermore, it is also interesting to note in the present studies that the methylating agent, MMS, is a stronger inducer of the adaptive response than the ethylating agent, EMS.

Ancient DNA reveals differences in behaviour and sociality between brown bears and extinct cave bears.

Science.gov (United States)

Fortes, Gloria G; Grandal-d'Anglade, Aurora; Kolbe, Ben; Fernandes, Daniel; Meleg, Ioana N; García-Vázquez, Ana; Pinto-Llona, Ana C; Constantin, Silviu; de Torres, Trino J; Ortiz, Jose E; Frischauf, Christine; Rabeder, Gernot; Hofreiter, Michael; Barlow, Axel

2016-10-01

Ancient DNA studies have revolutionized the study of extinct species and populations, providing insights on phylogeny, phylogeography, admixture and demographic history. However, inferences on behaviour and sociality have been far less frequent. Here, we investigate the complete mitochondrial genomes of extinct Late Pleistocene cave bears and middle Holocene brown bears that each inhabited multiple geographically proximate caves in northern Spain. In cave bears, we find that, although most caves were occupied simultaneously, each cave almost exclusively contains a unique lineage of closely related haplotypes. This remarkable pattern suggests extreme fidelity to their birth site in cave bears, best described as homing behaviour, and that cave bears formed stable maternal social groups at least for hibernation. In contrast, brown bears do not show any strong association of mitochondrial lineage and cave, suggesting that these two closely related species differed in aspects of their behaviour and sociality. This difference is likely to have contributed to cave bear extinction, which occurred at a time in which competition for caves between bears and humans was likely intense and the ability to rapidly colonize new hibernation sites would have been crucial for the survival of a species so dependent on caves for hibernation as cave bears. Our study demonstrates the potential of ancient DNA to uncover patterns of behaviour and sociality in ancient species and populations, even those that went extinct many tens of thousands of years ago. © 2016 John Wiley & Sons Ltd.

Inhibitory efficacy of the quantified prunellae spica extract on H22 tumor bearing mice

Science.gov (United States)

Wang, Zhi-ping; Chen, Tong-sheng

2013-02-01

Hepatocarcinoma, a malignant cancer, threaten human life badly. It is a current issue to seek the effective natural remedy from plant to treat cancer due to the resistence of the advanced hepatocarcinoma to chemotherapy. In this report, we assessed the antitumor activity of a prunellae spica aqueous extract (PSE) in vitro and in vivo. PSE was quantified by HPLC and UV. MTT assay showed that PSE did not effectively inhibit the growth of H22 cells. The in vivo anti-tumor activity was assessed by using the mice bearing H22 tumor. In vivo studies showed the higher antitumor efficacy of PSE without significant side effect assessed by the reduced tumor weight, and the extended survival time of the mice bearing H22 solid and ascites tumor. Collectively, PSE is a promising Chinese medicinal herb for treating hepatocarcinoma.

Non-contacting "snubber bearing" for passive magnetic bearing systems

Science.gov (United States)

Post, Richard F

2017-08-22

A new non-contacting magnetic "snubber" bearing is provided for application to rotating systems such as vehicular electromechanical battery systems subject to frequent accelerations. The design is such that in the equilibrium position the drag force of the snubber is very small (milliwatts). However in a typical case, if the rotor is displaced by as little as 2 millimeters a large restoring force is generated without any physical contact between the stationary and rotating parts of the snubber bearing.

Journal and Wave Bearing Impedance Calculation Software

Science.gov (United States)

Hanford, Amanda; Campbell, Robert

2012-01-01

The wave bearing software suite is a MALTA application that computes bearing properties for user-specified wave bearing conditions, as well as plain journal bearings. Wave bearings are fluid film journal bearings with multi-lobed wave patterns around the circumference of the bearing surface. In this software suite, the dynamic coefficients are outputted in a way for easy implementation in a finite element model used in rotor dynamics analysis. The software has a graphical user interface (GUI) for inputting bearing geometry parameters, and uses MATLAB s structure interface for ease of interpreting data. This innovation was developed to provide the stiffness and damping components of wave bearing impedances. The computational method for computing bearing coefficients was originally designed for plain journal bearings and tilting pad bearings. Modifications to include a wave bearing profile consisted of changing the film thickness profile given by an equation, and writing an algorithm to locate the integration limits for each fluid region. Careful consideration was needed to implement the correct integration limits while computing the dynamic coefficients, depending on the form of the input/output variables specified in the algorithm.

Bears, Big and Little. Young Discovery Library Series.

Science.gov (United States)

Pfeffer, Pierre

This book is written for children 5 through 10. Part of a series designed to develop their curiosity, fascinate them and educate them, this volume describes: (1) the eight species of bears, including black bear, brown bear, grizzly bear, spectacled bear, sun bear, sloth bear, polar bear, and giant panda; (2) geographical habitats of bears; (3)…

Effect of mixing geopolymer and peat on bearing capacity in Ogan Komering Ilir (OKI) by California bearing ratio (CBR) test

Science.gov (United States)

Raharja, Danang S.; Hadiwardoyo, Sigit P.; Rahayu, Wiwik; Zain, Nasuhi

2017-06-01

Geopolymer is binder material that consists of solid material and the activator solution. Geopolymer material has successfully replaced cement in the manufacture of concrete with aluminosilicate bonding system. Geopolymer concrete has properties similar to cement concrete with high compressive strength, low shrinkage value, relatively low creep value, as well as acid-resistant. Based on these, the addition of polymers in peat soils is expected to improve the bearing capacity of peat soils. A study on the influence of geopolymer addition in peat soils was done by comparing before and after the peat soil was mixed with geopolymer using CBR (California Bearing Ratio) test in unsoaked and soaked conditions. 10% mixture content of the peat dry was used, weighted with a variety of curing time 4 hours, 5 days, and 10 days. There were two methods of mixing: first, peat was mixed with fly ash geopolymer activators and mixed solution (waterglass, NaOH, water), and second, peat was mixed with fly ash and mixed geopolymer (waterglass, NaOH, water, fly ash). Changes were observed in specific gravity, dry density, acidity (pH), and the microscopic structure with Scanning Electron Microscope (SEM). Curing time did not significantly affect the CBR value. It even shows a tendency to decline with longer curing time. The first type mixture obtained CBR value of: 5.4% for 4 hours curing, 4.6% for 5 days curing and 3.6% for 10 days curing. The second type mixture obtained CBR value of: 6.1% for 4 hours curing, 5.2% for 5 days curing and 5.2% for 10 days curing. Furthermore, the specific gravity value, dry density, pH near neutral and swelling percentage increased. From both variants, the second type mixture shows better results than the first type mixture. The results of SEM (Scanning Electron Microscopy) show the structure of the peat which became denser with the fly ash particles filling the peat microporous. Also, the reaction of fly ash with geopolymer is indicated by the solid

Bearing tester data compilation analysis, and reporting and bearing math modeling

Science.gov (United States)

Cody, J. C.

1986-01-01

Integration of heat transfer coefficients, modified to account for local vapor quality, into the 45 mm bearing model has been completed. The model has been evaluated with two flow rates and subcooled and saturated coolant. The evaluation showed that by increasing the flow from 3.6 to 7.0 lbs/sec the average ball temperature was decreased by 102 F, using a coolant temperature of -230 F. The average ball temperature was decreased by 63 F by decreasing the inlet coolant temperature from saturated to -230 F at a flow rate of 7.0 lbs/sec. Since other factors such as friction, cage heating, etc., affect bearing temperatures, the above bearing temperature effects should be considered as trends and not absolute values. The two phase heat transfer modification has been installed in the 57 mm bearing model and the effects on bearing temperatures have been evaluated. The average ball temperature was decreased by 60 F by increasing the flow rate from 4.6 to 9.0 lbs/sec for the subcooled case. By decreasing the inlet coolant temperature from saturation to -24 F, the average ball temperature was decreased 57 F for a flow rate of 9.0 lbs/sec. The technique of relating the two phase heat transfer coefficient to local vapor quality will be applied to the tester model and compared with test data.

HemoHIM enhances the therapeutic efficacy of ionizing radiation treatment in tumor-bearing mice.

Science.gov (United States)

Park, Hae-Ran; Ju, Eun-Jin; Jo, Sung-Kee; Jung, Uhee; Kim, Sung-Ho

2010-02-01

Although radiotherapy is commonly used for a variety of cancers, radiotherapy alone does not achieve a satisfactory therapeutic outcome. In this study, we examined the possibility that HemoHIM can enhance the anticancer effects of ionizing radiation (IR) in melanoma-bearing mice. The HemoHIM was prepared by adding the ethanol-insoluble fraction to the total water extract of a mixture of three edible herbs-Angelica Radix, Cnidium Rhizoma, and Paeonia Radix. Anticancer effects of HemoHIM were evaluated in melanoma-bearing mice exposed to IR. IR treatment (5 Gy at 7 days after melanoma cell injection) reduced the weight of the solid tumors, and HemoHIM supplementation with IR enhanced the decreases in tumor weight (P HemoHIM administration also increased the activity of natural killer cells and cytotoxic T cells, although the proportions of these cells in spleen were not different. In addition, HemoHIM administration increased the interleukin-2 and tumor necrosis factor-alpha secretion from lymphocytes stimulated with concanavalin A, which seemed to contribute to the enhanced efficacy of HemoHIM in tumor-bearing mice treated with IR. In conclusion, HemoHIM may be a beneficial supplement during radiotherapy for enhancing the antitumor efficacy.

Tribology of alternative bearings.

Science.gov (United States)

Fisher, John; Jin, Zhongmin; Tipper, Joanne; Stone, Martin; Ingham, Eileen

2006-12-01

The tribological performance and biological activity of the wear debris produced has been compared for highly cross-linked polyethylene, ceramic-on-ceramic, metal-on-metal, and modified metal bearings in a series of in vitro studies from a single laboratory. The functional lifetime demand of young and active patients is 10-fold greater than the estimated functional lifetime of traditional polyethylene. There is considerable interest in using larger diameter heads in these high demand patients. Highly cross-linked polyethylene show a four-fold reduction in functional biological activity. Ceramic-on-ceramic bearings have the lowest wear rates and least reactive wear debris. The functional biological activity is 20-fold lower than with highly cross-linked polyethylene. Hence, ceramic-on-ceramic bearings address the tribological lifetime demand of highly active patients. Metal-on-metal bearings have substantially lower wear rates than highly cross-linked polyethylene and wear decreases with head diameter. Bedding in wear is also lower with reduced radial clearance. Differential hardness ceramic-on-metal bearings and the application of ceramic-like coatings reduce metal wear and ion levels.

Linking high harmonics from gases and solids.

Science.gov (United States)

Vampa, G; Hammond, T J; Thiré, N; Schmidt, B E; Légaré, F; McDonald, C R; Brabec, T; Corkum, P B

2015-06-25

When intense light interacts with an atomic gas, recollision between an ionizing electron and its parent ion creates high-order harmonics of the fundamental laser frequency. This sub-cycle effect generates coherent soft X-rays and attosecond pulses, and provides a means to image molecular orbitals. Recently, high harmonics have been generated from bulk crystals, but what mechanism dominates the emission remains uncertain. To resolve this issue, we adapt measurement methods from gas-phase research to solid zinc oxide driven by mid-infrared laser fields of 0.25 volts per ångström. We find that when we alter the generation process with a second-harmonic beam, the modified harmonic spectrum bears the signature of a generalized recollision between an electron and its associated hole. In addition, we find that solid-state high harmonics are perturbed by fields so weak that they are present in conventional electronic circuits, thus opening a route to integrate electronics with attosecond and high-harmonic technology. Future experiments will permit the band structure of a solid to be tomographically reconstructed.

Journal bearing impedance descriptions for rotordynamic applications

NARCIS (Netherlands)

Childs, D.W.; Moes, H.; Leeuwen, van H.J.

1977-01-01

Bearing impedance vectors are introduced for plain journal bearings which define the bearing reaction force components as a function of the bearing motion. Impedance descriptions are developed directly for the approximate Ocvirk (short) and Sommerfeld (long) bearing solutions. The impedance vector

TOOL ASSEMBLY WITH BI-DIRECTIONAL BEARING

Science.gov (United States)

Longhurst, G.E.

1961-07-11

A two-direction motion bearing which is incorporated in a refueling nuclear fuel element trsnsfer tool assembly is described. A plurality of bi- directional bearing assembliesare fixed equi-distantly about the circumference of the transfer tool assembly to provide the tool assembly with a bearing surface- for both axial and rotational motion. Each bi-directional bearing assembly contains a plurality of circumferentially bulged rollers mounted in a unique arrangement which will provide a bearing surface for rotational movement of the tool assembly within a bore. The bi-direc tional bearing assembly itself is capable of rational motion and thus provides for longitudinal movement of the tool assembly.

Estimating Wear Of Installed Ball Bearings

Science.gov (United States)

Keba, John E.; Mcvey, Scott E.

1993-01-01

Simple inspection and measurement technique makes possible to estimate wear of balls in ball bearing, without removing bearing from shaft on which installed. To perform measurement, one observes bearing cage while turning shaft by hand to obtain integral number of cage rotations and to measure, to nearest 2 degrees, number of shaft rotations producing cage rotations. Ratio between numbers of cages and shaft rotations depends only on internal geometry of bearing and applied load. Changes in turns ratio reflect changes in internal geometry of bearing provided measurements made with similar bearing loads. By assuming all wear occurs on balls, one computes effective value for this wear from change in turns ratio.

Efeitos do reiki na evolução do granuloma induzido através da inoculação do BCG em hamsters e do tumor ascítico de Ehrlich induzido em camundongos

OpenAIRE

Ricardo Rodrigues Garé

2008-01-01

Estudaram-se os efeitos da influência do Reiki na evolução do granuloma induzido experimentalmente pela inoculação do BCG no coxim plantar de hamsters, assim como os efeitos da mesma terapia em camundongos portadores do tumor ascítico de Ehrlich in vivo e in vitro. No modelo de inflamação granulomatosa crônica, utilizou-se 40 hamsters machos, os quais após serem inoculados com BCG no dia 0 no coxim da pata posterior direita, foram separados em dois grupos contendo 20 animais em cada. Um grupo...

Noise of oil lubricated journal bearings

International Nuclear Information System (INIS)

Rho, Byoung Hoo; Kim, Kyung Woong

2002-01-01

The purpose of the paper is to provide a procedure to calculate the noise of oil lubricated journal bearings. To do this, the nonlinear transient analysis of rotor-bearing system including rotor imbalance is performed. Acoustical properties of the bearing are investigated through frequency analysis of the pressure fluctuation of the fluid film calculated from the nonlinear analysis. Furthermore, a transmission theory of plane waves on a boundary of the outer surface of the bearing is used to obtain the sound pressure level of the bearing. Results show that the sound pressure level of the bearing can be increased with the rotational speed of the rotor although the whirl amplitude of the rotor is decreased at high speed. Noise estimating procedures presented in this paper could be an aid in the evaluation and understanding of acoustical properties of oil lubricated journal bearings

Grizzly bears (Ursus arctos horribilis) and black bears (Ursus americanus) prevent trabecular bone loss during disuse (hibernation).

Science.gov (United States)

McGee-Lawrence, Meghan E; Wojda, Samantha J; Barlow, Lindsay N; Drummer, Thomas D; Castillo, Alesha B; Kennedy, Oran; Condon, Keith W; Auger, Janene; Black, Hal L; Nelson, O Lynne; Robbins, Charles T; Donahue, Seth W

2009-12-01

Disuse typically causes an imbalance in bone formation and bone resorption, leading to losses of cortical and trabecular bone. In contrast, bears maintain balanced intracortical remodeling and prevent cortical bone loss during disuse (hibernation). Trabecular bone, however, is more detrimentally affected than cortical bone in other animal models of disuse. Here we investigated the effects of hibernation on bone remodeling, architectural properties, and mineral density of grizzly bear (Ursus arctos horribilis) and black bear (Ursus americanus) trabecular bone in several skeletal locations. There were no differences in bone volume fraction or tissue mineral density between hibernating and active bears or between pre- and post-hibernation bears in the ilium, distal femur, or calcaneus. Though indices of cellular activity level (mineral apposition rate, osteoid thickness) decreased, trabecular bone resorption and formation indices remained balanced in hibernating grizzly bears. These data suggest that bears prevent bone loss during disuse by maintaining a balance between bone formation and bone resorption, which consequently preserves bone structure and strength. Further investigation of bone metabolism in hibernating bears may lead to the translation of mechanisms preventing disuse-induced bone loss in bears into novel treatments for osteoporosis.

Prevalence of Trichinella spp. in black bears, grizzly bears, and wolves in the Dehcho Region, Northwest Territories, Canada, including the first report of T. nativa in a grizzly bear from Canada.

Science.gov (United States)

Larter, Nicholas C; Forbes, Lorry B; Elkin, Brett T; Allaire, Danny G

2011-07-01

Samples of muscle from 120 black bears (Ursus americanus), 11 grizzly bears (Ursus arctos), and 27 wolves (Canis lupus) collected in the Dehcho Region of the Northwest Territories from 2001 to 2010 were examined for the presence of Trichinella spp. larvae using a pepsin-HCl digestion assay. Trichinella spp. larvae were found in eight of 11 (73%) grizzly bears, 14 of 27 (52%) wolves, and seven of 120 (5.8%) black bears. The average age of positive grizzly bears, black bears, and wolves was 13.5, 9.9, and approximately 4 yr, respectively. Larvae from 11 wolves, six black bears, and seven grizzly bears were genotyped. Six wolves were infected with T. nativa and five with Trichinella T6, four black bears were infected with T. nativa and two with Trichinella T6, and all seven grizzly bears were infected with Trichinella T6 and one of them had a coinfection with T. nativa. This is the first report of T. nativa in a grizzly bear from Canada. Bears have been linked to trichinellosis outbreaks in humans in Canada, and black bears are a subsistence food source for residents of the Dehcho region. In order to assess food safety risk it is important to monitor the prevalence of Trichinella spp. in both species of bear and their cohabiting mammalian food sources.

Optimizing the dosing schedule of l-asparaginase improves its anti-tumor activity in breast tumor-bearing mice.

Science.gov (United States)

Shiromizu, Shoya; Kusunose, Naoki; Matsunaga, Naoya; Koyanagi, Satoru; Ohdo, Shigehiro

2018-04-01

Proliferation of acute lymphoblastic leukemic cells is nutritionally dependent on the external supply of asparagine. l-asparaginase, an enzyme hydrolyzing l-asparagine in blood, is used for treatment of acute lymphoblastic leukemic and other related blood cancers. Although previous studies demonstrated that l-asparaginase suppresses the proliferation of cultured solid tumor cells, it remains unclear whether this enzyme prevents the growth of solid tumors in vivo. In this study, we demonstrated the importance of optimizing dosing schedules for the anti-tumor activity of l-asparaginase in 4T1 breast tumor-bearing mice. Cultures of several types of murine solid tumor cells were dependent on the external supply of asparagine. Among them, we selected murine 4T1 breast cancer cells and implanted them into BALB/c female mice kept under standardized light/dark cycle conditions. The growth of 4T1 tumor cells implanted in mice was significantly suppressed by intravenous administration of l-asparaginase during the light phase, whereas its administration during the dark phase failed to show significant anti-tumor activity. Decreases in plasma asparagine levels due to the administration of l-asparaginase were closely related to the dosing time-dependency of its anti-tumor effects. These results suggest that the anti-tumor efficacy of l-asparaginase in breast tumor-bearing mice is improved by optimizing the dosing schedule. Copyright © 2018 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

Hydrostatic and hybrid bearing design

CERN Document Server

Rowe, W B

1983-01-01

Hydrostatic and Hybrid Bearing Design is a 15-chapter book that focuses on the bearing design and testing. This book first describes the application of hydrostatic bearings, as well as the device pressure, flow, force, power, and temperature. Subsequent chapters discuss the load and flow rate of thrust pads; circuit design, flow control, load, and stiffness; and the basis of the design procedures and selection of tolerances. The specific types of bearings, their design, dynamics, and experimental methods and testing are also shown. This book will be very valuable to students of engineering des

49 CFR 229.69 - Side bearings.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Side bearings. 229.69 Section 229.69....69 Side bearings. (a) Friction side bearings with springs designed to carry weight may not have more than 25 percent of the springs in any one nest broken. (b) Friction side bearings may not be run in...

Electron beam melting of bearing materials

Energy Technology Data Exchange (ETDEWEB)

Goldschmied, G.; Schuler, A. (Technische Univ., Vienna (Austria). Inst. fuer Allgemeine Elektrotechnik); Elsinger, G.; Koroschetz, F. (MIBA Gleitlager AG, Laakirchen (Austria)); Tschegg, E.K. (Technische Univ., Vienna (Austria). Inst. fuer Angewandte und Technische Physik)

1990-06-01

This paper reports on a surface treatment method for the bearing materials AlSn6 which permits the use of this material without the overlay usually required. Microstructural refinement is achieved by means of a surface melting technique using an electron beam with successive rapid solidification. Extremely fine tin precipitates are formed in the melted surface layer which lead to significantly better tribological properties of the bearing material. Tests compared the tribological properties for AlSn6 bearings treated by the surface melting technique with those of untreated bearings. Whereas all untreated bearings failed by seizure after only 2 h of testing, 30% of the tested bearings which had been surface melted survived the entire testing program without damage.

Treatment, conditioning and storage of solid alpha-bearing waste and cladding hulls. Paris, 5-7 December 1977

International Nuclear Information System (INIS)

1978-01-01

A synthesis of the current practices and research and development work in the area of alpha-bearing waste and cladding hulls management is presented in 27 papers. After a review of national programmes, general management aspects of radioactive wastes are presented and different techniques are exposed, mainly incineration, volume reduction, conditioning concepts and cladding hulls

Flywheel Challenge: HTS Magnetic Bearing

International Nuclear Information System (INIS)

Werfel, F N; Floegel-Delor, U; Riedel, T; Rothfeld, R; Wippich, D; Goebel, B

2006-01-01

A 200 mm cylindrical engineering prototype high temperature superconducting (HTS) was designed and fabricated. Measurements show that the 17 kg PM rotor can suspend safely 1000 kg in axial direction and 470 kg radially. The rationale for the bearing performance is to stabilize a 400 kg rotor of a new compact 5 kWh/280 kW flywheel energy storage system (COM - FESS). Measurements of the magnetic bearing force, stiffness and drag-torque are presented indicated the successful targeting a milestone in the HTS bearing technology. The influence of the PM configuration and the YBCO temperature on the bearing performance was experimentally studied, providing high-force or high-stiffness behaviour. The axial stiffness 5 kN/mm at 0.5 mm displacement is the highest value of a HTS bearing we know

Micromechanical investigation of sand migration in gas hydrate-bearing sediments

Science.gov (United States)

Uchida, S.; Klar, A.; Cohen, E.

2017-12-01

Past field gas production tests from hydrate bearing sediments have indicated that sand migration is an important phenomenon that needs to be considered for successful long-term gas production. The authors previously developed the continuum based analytical thermo-hydro-mechanical sand migration model that can be applied to predict wellbore responses during gas production. However, the model parameters involved in the model still needs to be calibrated and studied thoroughly and it still remains a challenge to conduct well-defined laboratory experiments of sand migration, especially in hydrate-bearing sediments. Taking the advantage of capability of micromechanical modelling approach through discrete element method (DEM), this work presents a first step towards quantifying one of the model parameters that governs stresses reduction due to grain detachment. Grains represented by DEM particles are randomly removed from an isotropically loaded DEM specimen and statistical analyses reveal that linear proportionality exists between the normalized volume of detached solids and normalized reduced stresses. The DEM specimen with different porosities (different packing densities) are also considered and statistical analyses show that there is a clear transition between loose sand behavior and dense sand behavior, characterized by the relative density.

Eastern slopes grizzly bear project

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-01-01

The cumulative effects of human activities on the grizzly bears in the central Canadian Rockies are not well known. As a result, a project was initiated in 1994 to address the urgent requirement for accurate scientific information on the habitat and populations of grizzly bears in the area of the Banff National Park and Kananaskis Country. This area is probably the most heavily used and developed area where the grizzly still survives. The information gathered throughout the course of this study will be used to better protect and manage the bears and other sensitive carnivores in the region. Using telemetry, researchers are monitoring 25 grizzly bears which were radio-collared in a 22,000 square-kilometer area in the upper Bow Valley drainage of the eastern Alberta slopes. The researchers involved in the project are working with representatives from Husky Oil and Talisman Energy on the sound development of the Moose Mountain oil and gas field without adversely affecting the grizzly bear population. Information collected over seven years indicated that the grizzly bears have few and infrequent offspring. Using the information gathered so far, the location of the Moose Mountain to Jumping Pound pipeline was carefully selected, since the bears recover very slowly from high mortality, and also considering that the food and cover had already been compromised by the high number of roads, trails and other human activities in the area. The status of the population and habitat of the grizzly bear will be assessed upon the conclusion of the field research phase in 2001. Models will be updated using the data obtained during eight years and will assist in the understanding of complex variables that affect grizzly bears.

A novel method for analysing key corticosteroids in polar bear (Ursus maritimus) hair using liquid chromatography tandem mass spectrometry.

Science.gov (United States)

Weisser, Johan J; Hansen, Martin; Björklund, Erland; Sonne, Christian; Dietz, Rune; Styrishave, Bjarne

2016-04-01

This paper presents the development and evaluation of a methodology for extraction, clean-up and analysis of three key corticosteroids (aldosterone, cortisol and corticosterone) in polar bear hair. Such a methodology can be used to monitor stress biomarkers in polar bears and may provide as a useful tool for long-term and retrospective information. We developed a combined pressurized liquid extraction (PLE)-solid phase extraction (SPE) procedure for corticosteroid extraction and clean-up followed by high pressure liquid chromatography tandem mass spectrometry (HPLC-MS/MS) analysis. This procedure allows for the simultaneous determination of multiple steroids, which is in contrast to previous polar bear studies based on ELISA techniques. Absolute method recoveries were 81%, 75% and 60% for cortisol, corticosterone and aldosterone, respectively. We applied the developed method on a hair sample pooled from four East Greenland polar bears. Herein cortisol and corticosterone were successfully determined in levels of 0.32±0.02ng/g hair and 0.13±0.02ng/g hair, respectively. Aldosterone was below limit of detection (LODpolar bears was consistent with cortisol levels previously determined in the Southern Hudson Bay and James Bay in Canada using ELISA kits. Copyright © 2016 Elsevier B.V. All rights reserved.

Aqueous extract from pecan nut [Carya illinoinensis (Wangenh) C. Koch] shell show activity against breast cancer cell line MCF-7 and Ehrlich ascites tumor in Balb-C mice.

Science.gov (United States)

Hilbig, Josiane; Policarpi, Priscila de Britto; Grinevicius, Valdelúcia Maria Alves de Souza; Mota, Nádia Sandrine Ramos Santos; Toaldo, Isabela Maia; Luiz, Marilde Terezinha Bordignon; Pedrosa, Rozangela Curi; Block, Jane Mara

2018-01-30

In Brazil many health disorders are treated with the consumption of different varieties of tea. Shell extracts of pecan nut (Carya illinoinensis), which have significant amounts of phenolic compounds in their composition, are popularly taken as tea to prevent diverse pathologies. Phenolic compounds from pecan nut shell extract have been associated with diverse biological effects but the effect on tumor cells has not been reported yet. The aim of the current work was to evaluate the relationship between DNA fragmentation, cell cycle arrest and apoptosis induced by pecan nut shell extract and its antitumor activity. Cytotoxicity, proliferation, cell death and cell cycle were evaluated in MCF-7 cells by MTT, colony assay, differential coloring and flow cytometry assays, respectively. DNA damage effects were evaluated through intercalation into CT-DNA and plasmid DNA cleavage. Tumor growth inhibition, survival time increase, apoptosis and cell cycle arrest were assessed in Ehrlich ascites tumor in Balb/C mice. The cytotoxic effect of pecan nut shell extracts, the induction of cell death by apoptosis and also the cell cycle arrest in MCF-7 cells have been demonstrated. The survival time in mice with Ehrlich ascites tumor increased by 67%. DNA damage was observed in the CT-DNA, plasmid DNA and comet assays. The mechanism involved in the antitumor effect of pecan nut shell extracts may be related to the activation of key proteins involved in apoptosis cell death (Bcl-XL, Bax and p53) and on the cell cycle regulation (cyclin A, cyclin B and CDK2). These results were attributed to the phenolic profile of the extract, which presented compounds such as gallic, 4-hydroxybenzoic, chlorogenic, vanillic, caffeic and ellagic acid, and catechin, epicatechin, epigallocatechin and epicatechin gallate. The results indicated that pecan nut shell extracts are effective against tumor cells growth and may be considered as an alternative to the treatment of cancer. Copyright © 2017

Conflict bear translocation: investigating population genetics and fate of bear translocation in Dachigam National Park, Jammu and Kashmir, India.

Science.gov (United States)

Mukesh; Sharma, Lalit Kumar; Charoo, Samina Amin; Sathyakumar, Sambandam

2015-01-01

The Asiatic black bear population in Dachigam landscape, Jammu and Kashmir is well recognized as one of the highest density bear populations in India. Increasing incidences of bear-human interactions and the resultant retaliatory killings by locals have become a serious threat to the survivorship of black bears in the Dachigam landscape. The Department of Wildlife Protection in Jammu and Kashmir has been translocating bears involved in conflicts, henceforth 'conflict bears' from different sites in Dachigam landscape to Dachigam National Park as a flagship activity to mitigate conflicts. We undertook this study to investigate the population genetics and the fate of bear translocation in Dachigam National Park. We identified 109 unique genotypes in an area of ca. 650 km2 and observed bear population under panmixia that showed sound genetic variability. Molecular tracking of translocated bears revealed that mostly bears (7 out of 11 bears) returned to their capture sites, possibly due to homing instincts or habituation to the high quality food available in agricultural croplands and orchards, while only four bears remained in Dachigam National Park after translocation. Results indicated that translocation success was most likely to be season dependent as bears translocated during spring and late autumn returned to their capture sites, perhaps due to the scarcity of food inside Dachigam National Park while bears translocated in summer remained in Dachigam National Park due to availability of surplus food resources. Thus, the current management practices of translocating conflict bears, without taking into account spatio-temporal variability of food resources in Dachigam landscape seemed to be ineffective in mitigating conflicts on a long-term basis. However, the study highlighted the importance of molecular tracking of bears to understand their movement patterns and socio-biology in tough terrains like Dachigam landscape.

Conflict bear translocation: investigating population genetics and fate of bear translocation in Dachigam National Park, Jammu and Kashmir, India.

Directory of Open Access Journals (Sweden)

Mukesh

Full Text Available The Asiatic black bear population in Dachigam landscape, Jammu and Kashmir is well recognized as one of the highest density bear populations in India. Increasing incidences of bear-human interactions and the resultant retaliatory killings by locals have become a serious threat to the survivorship of black bears in the Dachigam landscape. The Department of Wildlife Protection in Jammu and Kashmir has been translocating bears involved in conflicts, henceforth 'conflict bears' from different sites in Dachigam landscape to Dachigam National Park as a flagship activity to mitigate conflicts. We undertook this study to investigate the population genetics and the fate of bear translocation in Dachigam National Park. We identified 109 unique genotypes in an area of ca. 650 km2 and observed bear population under panmixia that showed sound genetic variability. Molecular tracking of translocated bears revealed that mostly bears (7 out of 11 bears returned to their capture sites, possibly due to homing instincts or habituation to the high quality food available in agricultural croplands and orchards, while only four bears remained in Dachigam National Park after translocation. Results indicated that translocation success was most likely to be season dependent as bears translocated during spring and late autumn returned to their capture sites, perhaps due to the scarcity of food inside Dachigam National Park while bears translocated in summer remained in Dachigam National Park due to availability of surplus food resources. Thus, the current management practices of translocating conflict bears, without taking into account spatio-temporal variability of food resources in Dachigam landscape seemed to be ineffective in mitigating conflicts on a long-term basis. However, the study highlighted the importance of molecular tracking of bears to understand their movement patterns and socio-biology in tough terrains like Dachigam landscape.

The role of human outdoor recreation in shaping patterns of grizzly bear-black bear co-occurrence

OpenAIRE

Ladle, Andrew; Steenweg, Robin; Shepherd, Brenda; Boyce, Mark S.

2018-01-01

Species' distributions are influenced by a combination of landscape variables and biotic interactions with other species, including people. Grizzly bears and black bears are sympatric, competing omnivores that also share habitats with human recreationists. By adapting models for multi-species occupancy analysis, we analyzed trail camera data from 192 trail camera locations in and around Jasper National Park, Canada to estimate grizzly bear and black bear occurrence and intensity of trail use....

The role of human outdoor recreation in shaping patterns of grizzly bear-black bear co-occurrence

OpenAIRE

Ladle, Andrew; Steenweg, Robin; Shepherd, Brenda; Boyce, Mark S.

2018-01-01

Species’ distributions are influenced by a combination of landscape variables and biotic interactions with other species, including people. Grizzly bears and black bears are sympatric, competing omnivores that also share habitats with human recreationists. By adapting models for multi-species occupancy analysis, we analyzed trail camera data from 192 trail camera locations in and around Jasper National Park, Canada to estimate grizzly bear and black bear occurrence and intensity of trail use....

Load responsive hydrodynamic bearing

Science.gov (United States)

Kalsi, Manmohan S.; Somogyi, Dezso; Dietle, Lannie L.

2002-01-01

A load responsive hydrodynamic bearing is provided in the form of a thrust bearing or journal bearing for supporting, guiding and lubricating a relatively rotatable member to minimize wear thereof responsive to relative rotation under severe load. In the space between spaced relatively rotatable members and in the presence of a liquid or grease lubricant, one or more continuous ring shaped integral generally circular bearing bodies each define at least one dynamic surface and a plurality of support regions. Each of the support regions defines a static surface which is oriented in generally opposed relation with the dynamic surface for contact with one of the relatively rotatable members. A plurality of flexing regions are defined by the generally circular body of the bearing and are integral with and located between adjacent support regions. Each of the flexing regions has a first beam-like element being connected by an integral flexible hinge with one of the support regions and a second beam-like element having an integral flexible hinge connection with an adjacent support region. A least one local weakening geometry of the flexing region is located intermediate the first and second beam-like elements. In response to application of load from one of the relatively rotatable elements to the bearing, the beam-like elements and the local weakening geometry become flexed, causing the dynamic surface to deform and establish a hydrodynamic geometry for wedging lubricant into the dynamic interface.

Diet and Co-ecology of Pleistocene Short-Faced Bears and Brown Bears in Eastern Beringia

Science.gov (United States)

Matheus, Paul E.

1995-11-01

Carbon and nitrogen stable isotope analysis of fossil bone collagen reveals that Pleistocene short-faced bears ( Arctodus simus) of Beringia were highly carnivorous, while contemporaneous brown bears ( Ursus arctos) had highly variable diets that included varying amounts of terrestrial vegetation, salmon, and small amounts of terrestrial meat. A reconsideration of the short-faced bear's highly derived morphology indicates that they foraged as scavengers of widely dispersed large mammal carcasses and were simultaneously designed both for highly efficient locomotion and for intimidating other large carnivores. This allowed Arctodus to forage economically over a large home range and seek out, procure, and defend carcasses from other large carnivores. The isotope data and this reconstruction of Arctodus' foraging behavior refute the hypothesis that competition from brown bears was a significant factor in the extinction of short-faced bears.

Bearing Change to Metal-On-Polyethylene for Ceramic Bearing Fracture in Total Hip Arthroplasty; Does It Work?

Science.gov (United States)

Lee, Soong Joon; Kwak, Hong Suk; Yoo, Jeong Joon; Kim, Hee Joong

2016-01-01

We evaluated the short-term to midterm results of reoperation with bearing change to metal-on-polyethylene (MoP) after ceramic bearing fracture in ceramic-on-ceramic total hip arthroplasty. Nine third-generation ceramic bearing fractures (6 heads and 3 liners) were treated with bearing change to MoP. Mean age at reoperation was 52.7 years. Mean follow-up was 4.3 years. During follow-up, 2 of 3 liner-fractured hips and 1 of 6 head-fractured hips showed radiologic signs of metallosis and elevated serum chromium levels. Re-reoperation with bearing rechange to a ceramic head was performed for the hips with metallosis. One liner-fractured hip had periprosthetic joint infection. Dislocation occurred in 3 hips. From our experience, bearing change to MoP is not a recommended treatment option for ceramic bearing fracture in total hip arthroplasty. Copyright © 2016 Elsevier Inc. All rights reserved.

Seismic isolation rubber bearings for nuclear facilities

International Nuclear Information System (INIS)

Fujita, Takafumi

1991-01-01

This paper describes results of biaxial breaking tests by compression and shear and by tension and shear for seismic isolation rubber bearings with bolted-type connections. The bearings used in the tests were low-damping rubber bearings, high-damping rubber bearings, and lead-rubber bearings. Three modes of failure of the bolted-type bearings were observed in the tests. They are the breaking failure by tension and shear; the breaking failure by compression and shear; and the buckling failure by compression and shear. The first and the second modes of failures are almost independent of the types and the sizes of the bearings. The breaking conditions of those failure modes are described in the axial-stress-shear-strain plane. This expression is useful for the evaluation of safety margins of the bearings. The paper outlines the basic design of the nuclear-grade bearings which were used for large-scale rubber bearing tests in a research project for seismic isolation of FBR plants. It also discusses the protection method against aging and the quality control which are important for implementation. (orig./HP)

Seismic isolation rubber bearings for nuclear facilities

International Nuclear Information System (INIS)

Fujita, Takafumi

1989-01-01

This paper describes results of biaxial breaking tests by compression and shear and by tension and shear for seismic isolation rubber bearings with bolted-type connections. The bearings used in the tests were low-damping rubber bearings, high-damping rubber bearings, and lead-rubber bearings. Three modes of failure of the bolted-type bearings were observed in the tests. They are the breaking failure by tension and shear; the breaking failure by compression and shear; and the buckling failure by compression and shear. The first and the second modes of failures are almost independent of the types and the sizes of the bearings. The breaking conditions of those failure modes are described in the axial stress-shear strain plane. This expression is useful for the evaluation of safety margins of the bearings. The paper outlines the basic design of the nuclear-grade bearings which were used for large-scale rubber bearing tests in a research project for seismic isolation of fast breeder reactor (FBR) plants. The paper also discusses the protection method against aging and the quality control which are important for implementation

Space Station alpha joint bearing

Science.gov (United States)

Everman, Michael R.; Jones, P. Alan; Spencer, Porter A.

1987-01-01

Perhaps the most critical structural system aboard the Space Station is the Solar Alpha Rotary Joint which helps align the power generation system with the sun. The joint must provide structural support and controlled rotation to the outboard transverse booms as well as power and data transfer across the joint. The Solar Alpha Rotary Joint is composed of two transition sections and an integral, large diameter bearing. Alpha joint bearing design presents a particularly interesting problem because of its large size and need for high reliability, stiffness, and on orbit maintability. The discrete roller bearing developed is a novel refinement to cam follower technology. It offers thermal compensation and ease of on-orbit maintenance that are not found in conventional rolling element bearings. How the bearing design evolved is summarized. Driving requirements are reviewed, alternative concepts assessed, and the selected design is described.

Reduced Bearing Excursion After Mobile-Bearing Unicompartmental Knee Arthroplasty is Associated With Poor Functional Outcomes.

Science.gov (United States)

Wahal, Naman; Gaba, Sahil; Malhotra, Rajesh; Kumar, Vijay; Pegg, Elise C; Pandit, Hemant

2018-02-01

A small proportion of patients with mobile unicompartmental knee arthroplasty (UKA) report poor functional outcomes in spite of optimal component alignment on postoperative radiographs. The purpose of this study is to assess whether there is a correlation between functional outcome and knee kinematics. From a cohort of consecutive cases of 150 Oxford medial UKA, patients with fair/poor functional outcome at 1-year postsurgery (Oxford Knee Score [OKS] bearing position with knee flexion angle. Mean OKS in the fair/poor group was 29.9 and the mean OKS in the good/excellent group was 41.1. The tibial slope, time taken to complete the exercises, and patellar tendon angle trend over the flexion range were similar in both the groups; however, bearing position and the extent of bearing excursion differed significantly. The total bearing excursion in the OKS bearing was positioned 1.7 mm more posterior on the tibia in the OKS bearing excursion and positioning, are associated with worse functional outcomes after mobile UKA. Copyright © 2017 Elsevier Inc. All rights reserved.

Rolling bearing analysis

CERN Document Server

Harris, Tedric A

2001-01-01

One of the most well-known experts in the field brings cutting-edge research to practitioners in the new edition of this important reference. Covers the improved mathematical calculations for rolling bearing endurance developed by the American Society of Mechanical Engineers and the Society of Lubrication and Tribology Engineers. Updated with new material on Condition-Based Maintenance, new testing methods, and new bearing materials.

Treatment of alpha bearing wastes

International Nuclear Information System (INIS)

1988-01-01

This report deals with the current state of the art of alpha waste treatment, which is an integral part of the overall nuclear waste management system. The International Atomic Energy Agency (IAEA) defines alpha bearing waste as 'waste containing one or more alpha emitting radionuclides, usually actinides, in quantities above acceptable limits'. The limits are established by national regulatory bodies. The limits above which wastes are considered as alpha contaminated refer to the concentrations of alpha emitters that need special consideration for occupational exposures and/or potential safety, health, or environmental impact during one or more steps from generation through disposal. Owing to the widespread use of waste segregation by source - that is, based upon the 'suspect origin' of the material - significant volumes of waste are being handled as alpha contaminated which, in fact, do not require such consideration by reason of risk or environmental concern. The quantification of de minimis concepts by national regulatory bodies could largely contribute to the safe reduction of waste volumes and associated costs. Other factors which could significantly contribute to the reduction of alpha waste arisings are an increased application of assaying and sorting, instrumentation and the use of feedback mechanisms to control or modify the processes which generate these wastes. Alpha bearing wastes are generated during fabrication and reprocessing of nuclear fuels, decommissioning of alpha contaminated facilities, and other activities. Most alpha wastes are contact handled, but a small portion may require shielding or remote handling because of high levels of neutron (n), beta (β), or gamma (γ) emissions associated with the waste material. This report describes the sources and characteristics of alpha wastes and strategies for alpha waste management. General descriptions of treatment processes for solid and liquid alpha wastes are included. 71 refs, 14 figs, 9 tabs

[The Innovation Office of the Paul-Ehrlich-Institut. Regulatory support during the scientific development of ATMP].

Science.gov (United States)

Ziegele, B; Dahl, L; Müller, A T

2011-07-01

In conformity with Regulation (EC) No. 1394/2007, advanced therapy medicinal products (ATMP) are now subject to the centralized marketing authorization procedure. This also applies to most medicinal products in regenerative medicine. ATMP that have been marketed in a member state by the end of 2008 must be centrally authorized by the end of 2012 at the latest. In exceptional cases, a national authorization is acceptable. Developers of these medicinal products are usually academic institutions or small- and medium-sized enterprises (SME). They focus on scientific aspects and usually have little experience with pharmaceutical law. The Innovation Office of the Paul-Ehrlich-Institut (PEI) is designed to support developers of medicinal products in the areas between research and development, on the one hand, and regulatory requirements, on the other. Its main role is supportive advice in the regulatory field with an emphasis on ATMP. For this purpose, the Innovation Office makes use of core competences from various experts at the PEI in order to provide a quality consulting service to those companies who are seeking advice as early as possible and hand in hand with the development process. The aim is to support the developer to identify the appropriate regulatory pathway and to provide advice for each individual medicinal product at its corresponding stage of development in order to develop a high-quality ATMP manufactured on the basis of positive nonclinical results and appropriate clinical studies that meet all the necessary requirements for the application of a marketing authorization.

Modeling of Hybrid Permanent Magnetic-Gas Bearings

DEFF Research Database (Denmark)

Morosi, Stefano; Santos, Ilmar

2009-01-01

Modern turbomachinery applications require nowadays ever-growing rotational speeds and high degree of reliability. It then becomes natural to focus the attention of the research to contact-free bearings elements. The present alternatives focus on gas lubricated journal bearings or magnetic bearings....... In the present paper, a detailed mathematical modeling of the gas bearing based on the compressible form of the Reynolds equation is presented. Perturbation theory is applied in order to identify the dynamic characteristic of the bearing. Due to the simple design of the magnetic bearings elements - being...... the rotor equilibrium position can be made independent on the rotational speed and applied load; it becomes function of the passive magnetic bearing offset. By adjusting the offset it is possible to significantly influence the dynamic coefficients of the hybrid bearing....

FY 1975 Report on results of Sunshine Project. Development of techniques of digging high-temperature beds (Development of solid bits and air-friction bearings); 1975 nendo koon chiso kussaku gijutsu no kaihatsu. Solid bit oyobi air friction bearing no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

NONE

1976-03-31

A combination of superhard alloy and diamond powder has been widely used as the solid type edge. The solid type with only a superhard alloy edge is no better than the traditional metal bit. It is ironical to admit that one of the most important items in the development of solid bits for digging high-temperature beds is not related to high temperature itself but development of highly efficient, long serviceable bits, growing out of the inefficient digging mechanisms for the conventional solid bits. It is considered that use of a superhard alloy edge is disadvantageous for digging hard rocks in the so-called scratching manner, for the two major reasons: (1) a superhard alloy is certainly resistant to wear, but nothing to that of diamond, and (2) it is homogeneous and lacks directional properties, such as the cleavage plane of diamond, which is effective for cutting. This project is aimed at development, on a trial basis, and eventual commercialization of new types of solid bits serviceable for extended periods by drastically improving suerhard alloys to provide them with new structures, e.g., those corresponding to the crystal axes of diamond, and also introducing a concept of crushing. (NEDO)

A motor with superconducting magnetic bearings

International Nuclear Information System (INIS)

Gladun, A.; Stoye, P.; Verges, P.; Gawalek, W.; Habisreuther, T.; Goernert, P.

1993-01-01

Superconducting bearings may be one of the most promising near term applications of HTSC. For use at liquid nitrogen temperature and below, they offer the advantage of lower energy consumption and higher reliability. Different bearing configurations have been proposed. But in order to substitute for conventional bearings a further increase in the critical current density of the superconductor and improved bearing concepts are necessary. For this it is necessary to take into account the peculiarities of the interaction between permanent magnets and bulk superconductors. As a contribution to this programme we present the model of a motor with superconducting magnetic bearings. (orig.)

Valve assembly having remotely replaceable bearings

International Nuclear Information System (INIS)

Johnson, E.R.; Tanner, D.E.

1980-01-01

A valve assembly having remotely replaceable bearings is disclosed wherein a valve disc is supported within a flow duct for rotation about a pair of axially aligned bearings, one of which is carried by a spindle received within a diametral bore in the valve disc, and the other of which is carried by a bearing support block releasably mounted on the duct circumferentially of an annular collar on the valve disc coaxial with its diametrical bore. The spindle and bearing support block are adapted for remote removal to facilitate servicing or replacement of the valve disc support bearings

Transient response of two lobe aerodynamic journal bearing

Directory of Open Access Journals (Sweden)

Saurabh Kumar Yadav

2018-03-01

Full Text Available The dynamic behavior of a rotor-dynamic system is greatly affected by the performance of aerodynamic bearing and the performance of bearing is characterized by the stiffness and damping coefficients. In the present work, stiffness and damping coefficients of bearing are computed and the performance of the bearing is greatly changed with the change in bearing air film profile. The effect of lobe offset factors on the transient performance of aerodynamic bearing is presented. Bifurcation and Poincare diagrams of two lobe journal bearing have been presented for different offset factors. A bearing designer can judge the bearing performance based on bifurcation diagrams.

Monitoring of plutonium contaminated solid waste streams. Chapter IV: Passive neutron assay

International Nuclear Information System (INIS)

Birkhoff, G.; Bondar, L.

1978-01-01

The fundamentals of the passive neutron technique for the non destructive assay of plutonium bearing materials are summarized. A reference monitor for the passive neutron assay of Pu contaminated solids is described in terms of instrumental design principles and performances. The theoretical model of this reference monitor with pertinent nuclear data and functions for the interpretation of experimental data is given

Servo Reduces Friction In Flexure Bearing

Science.gov (United States)

Clingman, W. Dean

1991-01-01

Proposed servocontrol device reduces such resistive torques as stiction, friction, ripple, and cogging in flexure bearing described in LAR-14348, "Flexure Bearing Reduces Startup Friction". Reduces frictional "bump" torque encountered when bearing ball runs into buildup of grease on bearing race. Also used as cable follower to reduce torque caused by cable and hoses when they bend because of motion of bearing. New device includes torquer across ball race. Torquer controlled by servo striving to keep flexure at null, removing torque to outer ring. In effect, device is inner control loop reducing friction, but does not control platforms or any outer-control-loop functions.

The effect of external dynamic loads on the lifetime of rolling element bearings: accurate measurement of the bearing behaviour

International Nuclear Information System (INIS)

Jacobs, W; Boonen, R; Sas, P; Moens, D

2012-01-01

Accurate prediction of the lifetime of rolling element bearings is a crucial step towards a reliable design of many rotating machines. Recent research emphasizes an important influence of external dynamic loads on the lifetime of bearings. However, most lifetime calculations of bearings are based on the classical ISO 281 standard, neglecting this influence. For bearings subjected to highly varying loads, this leads to inaccurate estimations of the lifetime, and therefore excessive safety factors during the design and unexpected failures during operation. This paper presents a novel test rig, developed to analyse the behaviour of rolling element bearings subjected to highly varying loads. Since bearings are very precise machine components, their motion can only be measured in an accurately controlled environment. Otherwise, noise from other components and external influences such as temperature variations will dominate the measurements. The test rig is optimised to perform accurate measurements of the bearing behaviour. Also, the test bearing is fitted in a modular structure, which guarantees precise mounting and allows testing different types and sizes of bearings. Finally, a fully controlled multi-axial static and dynamic load is imposed on the bearing, while its behaviour is monitored with capacitive proximity probes.

Remedial investigation work plan for Bear Creek (Y02-S600) at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

Turner, R.R.; Bogle, M.A.; Clapp, R.B.; Dearstone, K.; Dreier, R.B.; Early, T.O.; Herbes, S.E.; Loar, J.M.; Parr, P.D.; Southworth, G.R.

1991-07-01

As part of its response to Resource Conservation and Recovery Act (RCRA), the US Department of Energy had agreed to further investigate contamination of Bear Creek and its floodplain resulting from releases of hazardous waste or hazardous constituents from the Y-12 Plant solid waste management units (SWMU) located in the Bear Creek watershed. That proposed RCRA Facility Investigation has been modified to incorporate the requirements of Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) into a Remedial Investigation (RI) Plan for Bear Creek. This document is the RI Plan for Bear Creek and its flood-of-record floodplain. The following assumptions were made in the preparation of this RI Plan: (1) That source-area groundwater monitoring will be conducted as a part of the comprehensive groundwater monitoring plan for the Bear Creek Hydrogeologic Regime; and (2) that postclosure activities associated with each SWMU do not explicitly include a comprehensive assessment of surface water, sediment, and floodplain soil contamination in Bear Creek and its tributaries. The RI Plan is thus intended to provide a more comprehensive evaluation of Bear Creek and its floodplain than that provided by the investigative monitoring and risk assessment activities associated with the ten individual SWMUs. RI activities will be carefully coordinated with other monitoring and assessment activities to avoid redundancy and to maximize the utility of data gathered during the investigation. 121 refs., 61 figs., 46 tabs

A prototype construction of bearing heater system

International Nuclear Information System (INIS)

Firman Silitonga

2007-01-01

A bearing heater system has been successfully constructed using transformer-like method of 1000 VA power, 220 V primary voltage, and 50 Hz electrical frequency. The bearing heater consists of primary coil 230 turns, U type and bar-type iron core with 36 cm 2 , 9 cm 2 ,and 3 cm 2 cross-section, and electrical isolation. The bearing heater is used to enlarge the diameter of the bearing so that it can be easily fixed on an electric motor shaft during replacement because the heating is conducted by treated the bearing as a secondary coil of a transformer. This bearing heater can be used for bearing with 3 and 6 cm of inner diameter and 12 cm of maximum outside diameter. (author)

Roller bearing geometry design

Science.gov (United States)

Savage, M.; Pinkston, B. H. W.

1976-01-01

A theory of kinematic stabilization of rolling cylinders is extended and applied to the design of cylindrical roller bearings. The kinematic stabilization mechanism puts a reverse skew into the rolling elements by changing the roller taper. Twelve basic bearing modification designs are identified amd modeled. Four have single transverse convex curvature in their rollers while eight have rollers which have compound transverse curvature made up of a central cylindrical band surrounded by symmetric bands with slope and transverse curvature. The bearing designs are modeled for restoring torque per unit axial displacement, contact stress capacity, and contact area including dynamic loading, misalignment sensitivity and roller proportion. Design programs are available which size the single transverse curvature roller designs for a series of roller slopes and load separations and which design the compound roller bearings for a series of slopes and transverse radii of curvature. The compound rollers are proportioned to have equal contact stresses and minimum size. Design examples are also given.

Gear bearing drive

Science.gov (United States)

Mavroidis, Constantinos (Inventor); Vranish, John M. (Inventor); Weinberg, Brian (Inventor)

2011-01-01

A gear bearing drive provides a compact mechanism that operates as an actuator providing torque and as a joint providing support. The drive includes a gear arrangement integrating an external rotor DC motor within a sun gear. Locking surfaces maintain the components of the drive in alignment and provide support for axial loads and moments. The gear bearing drive has a variety of applications, including as a joint in robotic arms and prosthetic limbs.

The Effect of Non-Circular Bearing Shapes in Hydrodynamic Journal Bearings on the Vibration Behavior of Turbocharger Structures

Directory of Open Access Journals (Sweden)

Lukas Bernhauser

2017-03-01

Full Text Available Increasing quality demands of combustion engines require, amongst others, improvements of the engine’s acoustics and all (subcomponents mounted to the latter. A significant impact to the audible tonal noise spectrum results from the vibratory motions of fast-rotating turbocharger rotor systems in multiple hydrodynamic bearings such as floating bearing rings. Particularly, the study of self-excited non-linear vibrations of the rotor-bearing systems is crucial for the understanding, prevention or reduction of the noise and, consequently, for a sustainable engine acoustics development. This work presents an efficient modeling approach for the investigation, optimization, and design improvement of complex turbocharger rotors in hydrodynamic journal bearings, including floating bearing rings with circular and non-circular bearing geometries. The capability of tonal non-synchronous vibration prevention using non-circular bearing shapes is demonstrated with dynamic run-up simulations of the presented model. These findings and the performance of our model are compared and validated with results of a classical Laval/Jeffcott rotor-bearing model and a specific turbocharger model found in the literature. It is shown that the presented simulation method yields fast and accurate results and furthermore, that non-circular bearing shapes are an effective measure to reduce or even prevent self-excited tonal noise.

LIGHT-WEIGHT LOAD-BEARING STRUCTURE

DEFF Research Database (Denmark)

2009-01-01

The invention relates to a light-weight load-bearing structure (1) with optimized compression zone (2), where along one or more compression zones (2) in the structure (1) to be cast a core (3) of strong concrete is provided, which core (3) is surrounded by concrete of less strength (4) compared...... to the core (3) of strong concrete. The invention also relates to a method of casting of light-weight load-bearing structures (1) with optimized compression zone (2) where one or more channels, grooves, ducts, pipes and/or hoses (5) formed in the load-bearing structure (1) serves as moulds for moulding one...... or more cores (3) of strong concrete in the light-weight load-bearing structure (1)....

Development and Evaluation of Titanium Spacesuit Bearings

Science.gov (United States)

Rhodes, Richard; Battisti, Brian; Ytuarte, Raymond, Jr.; Schultz, Bradley

2016-01-01

The Z-2 Prototype Planetary Extravehicular Space Suit Assembly is a continuation of NASA's Z-series of spacesuits, designed with the intent of meeting a wide variety of exploration mission objectives, including human exploration of the Martian surface. Incorporating titanium bearings into the Z-series space suit architecture allows us to reduce mass by an estimated 23 lbs per suit system compared to the previously used stainless steel bearing race designs, without compromising suit functionality. There are two obstacles to overcome when using titanium for a bearing race- 1) titanium is flammable when exposed to the oxygen wetted environment inside the space suit and 2) titanium's poor wear properties are often challenging to overcome in tribology applications. In order to evaluate the ignitability of a titanium space suit bearing, a series of tests were conducted at White Sands Test Facility (WSTF) that introduced the bearings to an extreme test profile, with multiple failures imbedded into the test bearings. The testing showed no signs of ignition in the most extreme test cases; however, substantial wear of the bearing races was observed. In order to design a bearing that can last an entire exploration mission (approx. 3 years), design parameters for maximum contact stress need to be identified. To identify these design parameters, bearing test rigs were developed that allow for the quick evaluation of various bearing ball loads, ball diameters, lubricants, and surface treatments. This test data will allow designers to minimize the titanium bearing mass for a specific material and lubricant combination and design around a cycle life requirement for an exploration mission. This paper reviews the current research and testing that has been performed on titanium bearing races to evaluate the use of such materials in an enriched oxygen environment and to optimize the bearing assembly mass and tribological properties to accommodate for the high bearing cycle life for an

The thermodynamic properties of a new type catcher bearing used in active magnetic bearings system

International Nuclear Information System (INIS)

Jin, Chaowu; Zhu, Yili; Xu, Longxiang; Xu, Yuanping; Zheng, Yantong

2015-01-01

Normally a rotor levitated by active magnetic bearings (AMBs) system would rotate without contacting with any stator component, but the possibility still remains that the supporting force might lose temporarily or permanently, thus requiring the Catcher bearings (CBs) to provide backup protection in case of the failure of AMBs. A new type CB with two separate rolling element bearing series could have the speed distribution between the inner race and intermediate race according to certain ratio, in which the speed of each roller element bearing decreases with the limit speed of the whole CB increasing, offering high capability to sustain its initial rotation speed. Based on the theory of heat transfer, tribology, and rotor dynamics, this paper analyzes the thermal structure of double-decker catcher bearing (DDCB) and single-decker catcher bearing (SDCB), respectively. Through this structure, the thermal resistances and equations of heat transfer can be obtained. Then we calculate the friction heat and temperature distribution in the various CBs upon rotor's dropping on SDCB or DDCB, followed by the discussion on the CBs temperature rise's effects on lubrication conditions and rotor dynamics parameters. Finally various experiments are carried out to measure the temperature rise of different CBs. The results obtained validate the theoretical analysis and also provide main methods to reduce heat generation. Using DDCB is proved to be effective to reduce the temperature rise. - Highlights: • The DDCB is a more suitable catcher bearing for AMBs. • Compared to SDCB, using DDCB, the temperature rise can decrease in the same states. • A lower viscosity of lubricant may induce a lower temperature rise. • The inner raceway temperature of the first layer bearing is the highest. • Reducing the unbalance mass of the rotor is a method to decrease the temperature rise

Noise estimation of oil lubricated journal bearings

International Nuclear Information System (INIS)

Rho, Byoung Hoo; Kim, Kyung Woong

2003-01-01

Noise estimating procedures of oil lubricated journal bearings are presented. Nonlinear analysis of rotor-bearing system including unbalance mass of the rotor is performed in order to obtain acoustical properties of the bearing. Acoustical properties of the bearing are investigated through frequency analysis of the pressure fluctuation of the fluid film calculated from the nonlinear analysis. Noise estimating procedures presented in this paper could aid in the evaluation and understanding of acoustical properties of oil lubricated journal bearings

Individual effects of seasonal changes, visitor density, and concurrent bear behavior on stereotypical behaviors in captive polar bears (Ursus maritimus).

Science.gov (United States)

Kelly, Krista R; Harrison, Michelle L; Size, Daniele D; MacDonald, Suzanne E

2015-01-01

Stereotypical behaviors in captive polar bears (Ursus maritimus) can be detrimental to their welfare. These behaviors can be reduced through enrichment programs but are often not completely eliminated, so identifying potential triggers is important. The present study investigated the influences of seasonal changes, visitor density, and concurrent bear activity on stereotypical behaviors exhibited by 3 captive polar bears at the Toronto Zoo. All bears exhibited these behaviors; however, individual differences were found in duration and form. The male exhibited less stereotypical behavior during spring, and the females exhibited less stereotypical behavior during winter. An increase in visitor density was associated with more stereotypical behavior in 1 female but less stereotypical behavior in the other 2 bears. All bears engaged in more stereotypical behaviors when the other bears were inactive, and 1 female engaged in more stereotypical behaviors when the other bears were out of sight. Further, when conspecifics were active, all bears engaged in less stereotypical behaviors. Given the variability among individual bears, future enrichment programs must be tailored to the needs of individuals to maximize efficacy.

49 CFR 229.64 - Plain bearings.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Plain bearings. 229.64 Section 229.64 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION....64 Plain bearings. A plain bearing box shall contain visible free oil and may not be cracked to the...

Ceramic Rail-Race Ball Bearings

Science.gov (United States)

Balzer, Mark A.; Mungas, Greg S.; Peters, Gregory H.

2010-01-01

Non-lubricated ball bearings featuring rail races have been proposed for use in mechanisms that are required to function in the presence of mineral dust particles in very low-pressure, dry environments with extended life. Like a conventional ball bearing, the proposed bearing would include an inner and an outer ring separated by balls in rolling contact with the races. However, unlike a conventional ball bearing, the balls would not roll in semi-circular or gothic arch race grooves in the rings: instead, the races would be shaped to form two or more rails (see figure). During operation, the motion of the balls would push dust particles into the spaces between the rails where the particles could not generate rolling resistance for the balls

Identification of Bearing Failure Using Signal Vibrations

Science.gov (United States)

Yani, Irsyadi; Resti, Yulia; Burlian, Firmansyah

2018-04-01

Vibration analysis can be used to identify damage to mechanical systems such as journal bearings. Identification of failure can be done by observing the resulting vibration spectrum by measuring the vibration signal occurring in a mechanical system Bearing is one of the engine elements commonly used in mechanical systems. The main purpose of this research is to monitor the bearing condition and to identify bearing failure on a mechanical system by observing the resulting vibration. Data collection techniques based on recordings of sound caused by the vibration of the mechanical system were used in this study, then created a database system based bearing failure due to vibration signal recording sounds on a mechanical system The next step is to group the bearing damage by type based on the databases obtained. The results show the percentage of success in identifying bearing damage is 98 %.

Management of brown bears (Ursus arctos) in Europe.

OpenAIRE

Klenzendorf, Sybille A.

1997-01-01

Management of Brown Bears (Ursus arctos) in Europe. Sybille A. Klenzendorf (Abstract) Successful conservation of brown bears (Ursus arctos) in Europe is associated with public acceptance of damages caused by bears. Recent increases in sheep depredation and beehive damage in central Austria resulted in the deaths of two bears there. Since bear numbers are low in most European populations, alternatives to the elimination of problem bears associated with dam...

Conservation of brown bear in the Alps: space use and settlement behavior of reintroduced bears

Science.gov (United States)

Preatoni, Damiano; Mustoni, Andrea; Martinoli, Adriano; Carlini, Eugenio; Chiarenzi, Barbara; Chiozzini, Simonetta; Van Dongen, Stefan; Wauters, Luc A.; Tosi, Guido

2005-11-01

Large carnivores typically need large home ranges containing habitats patches of different quality. Consequently, their conservation requires habitat protection and management at the landscape scale. In some cases, reintroduction might be used to support remnant or restore extinct populations. This is the case for the brown bear ( Ursus arctos) in the Italian Alps. We monitored spacing behavior and settlement of reintroduced brown bears in Adamello-Brenta Natural Park, North-Italy, using radio-tracking. Habitat use, dispersion and survival were studied to evaluate the success of reintroduction and possible conflicts with man. All three males and five of seven females settled in the study area. Most bears roamed widely the first months after release, exploring the new habitat. Patterns of home range overlap between seasons and years revealed that home range use stabilized the year after first hibernation. Home ranges were larger in the mating season (May-July) than in spring or autumn. Home ranges varied between 34 and 1813 km 2 the year after release, but core-areas, where feeding activity was concentrated, were much smaller. Some bears had exclusive core-areas in summer and autumn, but most showed considerable core-area overlap with animals of the same and/or the opposite sex. Bears selected deciduous forests, mixed and conifer forests were used according to availability, and areas with anthropogenic disturbance were avoided. Most bears settled and some reproduced successfully at the release site, causing high initial population growth, suggesting that reintroduction can help to re-establish a brown bear population in the Italian Alps.

2-Acetylpyridine N4-Phenyl- Thiosemicarbazone as a new tool for tumour diagnosis

International Nuclear Information System (INIS)

Soares, Marcella Araugio; Pesquero, Jorge Luiz

2009-01-01

The aim of this work was to determine in vivo biodistribution of radiolabelled 2-acetylpyridine N4 phenyl thiosemicarbazone (Ph) and to evaluate its applicability for tumour diagnosis. Ph was labelled with 125 I using lactoperoxidase method and radiochemical analysis was performed by chromatography. 125 I-Ph production was successful with 86 ± 9.2% of radiochemical purity and high specific activity (17.6 TBq /mmol). 125 I-Ph was used for biodistribution and pharmacokinetics studies on Swiss mice bearing Ehrlich solid tumour. 125 I-Ph presented a rapid blood clearance (T 1/2 = 97.2 min.) and the kidneys were the main excretion pathway (CL0.01 mL/min). 125 I-Ph uptake was significant in tumour (2.5%ID/g) and tumour-to-normal tissue uptake was more than 20-fold higher depending on the organ. The uptake by the organs like heart, lungs, stomach and liver followed the blood perfusion. Our results suggest that 125 I-Ph possess indispensable characteristics for an efficient radiopharmaceutical for tumour diagnosis. The next step will be to evaluate the quality of tumour SPECT images provided by 131 I-Ph. (author)

2-Acetylpyridine N4-Phenyl- Thiosemicarbazone as a new tool for tumour diagnosis

Energy Technology Data Exchange (ETDEWEB)

Soares, Marcella Araugio; Pesquero, Jorge Luiz [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Fisiologia e Biofisica], e-mail: marcellaaraugio@yahoo.com.br; Costa, Pryscila R. da; Mendes, Isolda M.C.; Beraldo, Heloisa; Santos, Raquel Gouvea dos [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)], e-mail: santosr@cdtn.br

2009-07-01

The aim of this work was to determine in vivo biodistribution of radiolabelled 2-acetylpyridine N4 phenyl thiosemicarbazone (Ph) and to evaluate its applicability for tumour diagnosis. Ph was labelled with {sup 125}I using lactoperoxidase method and radiochemical analysis was performed by chromatography. {sup 125}I-Ph production was successful with 86 {+-} 9.2% of radiochemical purity and high specific activity (17.6 TBq /mmol). {sup 125}I-Ph was used for biodistribution and pharmacokinetics studies on Swiss mice bearing Ehrlich solid tumour. {sup 125}I-Ph presented a rapid blood clearance (T{sub 1/2}= 97.2 min.) and the kidneys were the main excretion pathway (CL0.01 mL/min). {sup 125}I-Ph uptake was significant in tumour (2.5%ID/g) and tumour-to-normal tissue uptake was more than 20-fold higher depending on the organ. The uptake by the organs like heart, lungs, stomach and liver followed the blood perfusion. Our results suggest that {sup 125}I-Ph possess indispensable characteristics for an efficient radiopharmaceutical for tumour diagnosis. The next step will be to evaluate the quality of tumour SPECT images provided by {sup 131}I-Ph. (author)

Difference of ore-bearing and non-ore-bearing pegmatite in the Guangshigou area and its research significance

International Nuclear Information System (INIS)

Zuo Wenqian; Zhang Zhanshi; Sha Yazhou; Rao Chaojun

2011-01-01

Guangshigou uranium deposit is one of the typical granite-pegmatite uranium deposits in China, the ore-body are located in the density zone of the outside contact zone of granite pluton. To distinguish the ore-bearing and Non-ore-bearing pegmatite is one of the most practices and have great significance for the effect of mineral exploration. Based on the field investigation and former research results, contrast research on the characteristics of the pegmatite on petrology, geophysical, geochemistry and stable isotopes have been carried out. It is pointed out that the ore-bearing pegmatite differ from the non-ore-bearing one from macro-and-micro-view in Guangshigou Uranium deposits, the main characteristics are summarized; the macro-and-micro signs are established, the genetic difference between the ore-bearing and non-ore-bearing pegmatite are discussed primarily. The achievements would be helpful for prospecting and researching of this type uranium deposits in China. (authors)

Accuracy of Spindle Units with Hydrostatic Bearings

Directory of Open Access Journals (Sweden)

Fedorynenko Dmytro

2016-06-01

Full Text Available The work is devoted to the research of precision regularities in a spindle unit by the trajectory of the spindle installed on hydrostatic bearings. The mathematical model of trajectories spindle with lumped parameters that allows to define the position of the spindle with regard the simultaneous influence of design parameters, geometrical deviations ofform, temperature deformation bearing surfaces, the random nature of operational parameters and technical loads of hydrostatic bearings has been developed. Based on the results of numerical modeling the influence of shape errors of bearing surface of hydrostatic bearing on the statistical characteristics of the radius vector trajectories of the spindle by varying the values rotational speed of the spindle and oil pressure in front hydrostatic bearing has been developed. The obtained statistical regularities of precision spindle unit have been confirmed experimentally. It has been shown that an effective way to increase the precision of spindle units is to regulate the size of the gap in hydrostatic spindle bearings. The new design of an adjustable hydrostatic bearing, which can improve the accuracy of regulation size gap has been proposed.

36 CFR 13.1236 - Bear orientation.

Science.gov (United States)

2010-07-01

... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Bear orientation. 13.1236 Section 13.1236 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR... Developed Area § 13.1236 Bear orientation. All persons visiting the BCDA must receive an NPS-approved Bear...

14 CFR 29.623 - Bearing factors.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Bearing factors. 29.623 Section 29.623... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction General § 29.623 Bearing factors. (a... subject to pounding or vibration, must have a bearing factor large enough to provide for the effects of...

[Advances in studies on bear bile powder].

Science.gov (United States)

Zhou, Chao-fan; Gao, Guo-jian; Liu, Ying

2015-04-01

In this paper, a detailed analysis was made on relevant literatures about bear bile powder in terms of chemical component, pharmacological effect and clinical efficacy, indicating bear bile powder's significant pharmacological effects and clinical application in treating various diseases. Due to the complex composition, bear bile powder is relatively toxic. Therefore, efforts shall be made to study bear bile powder's pharmacological effects, clinical application, chemical composition and toxic side-effects, with the aim to provide a scientific basis for widespread reasonable clinical application of bear bile powder.

Magnetically leviated superconducting bearing

Science.gov (United States)

Weinberger, Bernard R.; Lynds, Jr., Lahmer

1993-01-01

A magnetically levitated superconducting bearing includes a magnet (2) mounted on a shaft (12) that is rotatable around an axis of rotation and a Type II superconductor (6) supported on a stator (14) in proximity to the magnet (2). The superconductor (6) is positioned so that when it is cooled to its superconducting state in the presence of a magnetic field, it interacts with the magnet (2) to produce an attractive force that levitates the magnet (2) and supports a load on the shaft (12). The interaction between the superconductor (6) and magnet(2) also produces surface screening currents (8) that generate a repulsive force perpendicular to the load. The bearing also has means for maintaining the superconductor at a temperature below its critical temperature (16, 18). The bearing could also be constructed so the magnet (2) is supported on the stator (14) and the superconductor (6) is mounted on the shaft (12). The bearing can be operated by cooling the superconductor (6) to its superconducting state in the presence of a magnetic field.

A theoretical-experimental study of backup bearings

DEFF Research Database (Denmark)

Lampe Linhares da Fonseca, Cesar Augusto

of two types of backup bearings, which are investigated experimentally and theoretically. The first type is a conventional ball bearing commonly used in industrial applications. The second is an unconventional bearing that, which contains pins inside the clearance for the rotor to impact on. The main...... both types of bearings for further investigation. Also, a full failure of the control and a rotor drop on the ball bearing as backup bearing is investigated by removing the magnetic forces. The nonlinear features of the dynamics of the rotor are assessed for different levels of unbalance. It has been...... radial forces. Remaining in this condition, it may lead to permanent damage or total failure of the machine. This is why the backup bearing design has to be carefully planned and investigated as to whether it helps to protect the integrity of the machine. This PhD thesis provides a comprehensive study...

Genomic sequencing of Pleistocene cave bears

Energy Technology Data Exchange (ETDEWEB)

Noonan, James P.; Hofreiter, Michael; Smith, Doug; Priest, JamesR.; Rohland, Nadin; Rabeder, Gernot; Krause, Johannes; Detter, J. Chris; Paabo, Svante; Rubin, Edward M.

2005-04-01

Despite the information content of genomic DNA, ancient DNA studies to date have largely been limited to amplification of mitochondrial DNA due to technical hurdles such as contamination and degradation of ancient DNAs. In this study, we describe two metagenomic libraries constructed using unamplified DNA extracted from the bones of two 40,000-year-old extinct cave bears. Analysis of {approx}1 Mb of sequence from each library showed that, despite significant microbial contamination, 5.8 percent and 1.1 percent of clones in the libraries contain cave bear inserts, yielding 26,861 bp of cave bear genome sequence. Alignment of this sequence to the dog genome, the closest sequenced genome to cave bear in terms of evolutionary distance, revealed roughly the expected ratio of cave bear exons, repeats and conserved noncoding sequences. Only 0.04 percent of all clones sequenced were derived from contamination with modern human DNA. Comparison of cave bear with orthologous sequences from several modern bear species revealed the evolutionary relationship of these lineages. Using the metagenomic approach described here, we have recovered substantial quantities of mammalian genomic sequence more than twice as old as any previously reported, establishing the feasibility of ancient DNA genomic sequencing programs.

14 CFR 27.623 - Bearing factors.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Bearing factors. 27.623 Section 27.623... STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction General § 27.623 Bearing factors. (a) Except... subject to pounding or vibration, must have a bearing factor large enough to provide for the effects of...

14 CFR 25.623 - Bearing factors.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Bearing factors. 25.623 Section 25.623... STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction General § 25.623 Bearing factors. (a) Except... subject to pounding or vibration, must have a bearing factor large enough to provide for the effects of...

Grease lubrication in rolling bearings

CERN Document Server

Lugt, Piet M

2012-01-01

The definitive book on the science of grease lubrication for roller and needle bearings in industrial and vehicle engineering. Grease Lubrication in Rolling Bearings provides an overview of the existing knowledge on the various aspects of grease lubrication (including lubrication systems) and the state of the art models that exist today. The book reviews the physical and chemical aspects of grease lubrication, primarily directed towards lubrication of rolling bearings. The first part of the book covers grease composition, properties and rheology, including thermal

Variation in Scent Compounds of Oil-Bearing Rose (Rosa damascena Mill. Produced by Headspace Solid Phase Microextraction, Hydrodistillation and Solvent Extraction

Directory of Open Access Journals (Sweden)

Sabri Erbaş

2016-03-01

Full Text Available In this research, rose oil and rose water were hydro-distilled from the fresh oil-bearing rose flowers (Rosa damascena Mill. using Clevenger-type apparatus. Rose concretes were extracted from the fresh rose flowers by using non-polar solvents, e.g. diethyl ether, petroleum ether, cyclo-hexane, chloroform and n-hexane, and subsequently by evaporation of the solvents under vacuum. Absolutes were produced from the concretes with ethyl alcohol extraction at -20°C, leaving behind the wax and other paraffinic substances. Scent compounds of all these products detected by gas chromatography (GC-FID/GC-MS were compared with the natural scent compounds of fresh rose flower detected by using headspace solid phase microextraction (HS-SPME with carboxen/polydimethylsiloxane (CAR/PDMS fiber. A total of 46 compounds analysis were identified by HS-SPME-GC-MS in the fresh flower, and a total of 15 compounds were identified by GC-MS in the hydrodistilled rose oil. While main compounds in rose oil were geraniol (35.4%, citronellol (31.6%, and nerol (15.3%, major compound in fresh rose flower, rose water and residue water was phenylethyl alcohol (43.2, 35.6 and 98.2%, respectively. While the highest concrete yield (0.7% was obtained from diethyl ether extraction, the highest absolute yield (70.9% was obtained from the n-hexane concrete. The diethyl ether concrete gave the highest productivity of absolute, as 249.7 kg of fresh rose flowers was needed to produce 1 kg of absolute.

Magnetic translator bearings

Science.gov (United States)

Hockney, Richard L. (Inventor); Downer, James R. (Inventor); Eisenhaure, David B. (Inventor); Hawkey, Timothy J. (Inventor); Johnson, Bruce G. (Inventor)

1990-01-01

A magnetic bearing system for enabling translational motion includes a carriage and a shaft for movably supporting the carriage; a first magnetic bearing fixed to one of the carriage and shaft and slidably received in a first channel of the other of the carriage and shaft. The first channel is generally U shaped with two side walls and a back wall. The magnetic bearing includes a pair of spaced magnetic pole pieces, each pole piece having a pair of electromagnetic coils mounted on poles on opposite ends of the pole piece proximate the side walls, and a third electromagnetic coil mounted on a pole of the pole piece proximate the backwall; a motion sensor for sensing translational motion along two axes and rotationally about three axes of the carriage and shaft relative to each other; and a correction circuit responsive to the sensor for generating a correction signal to drive the coils to compensate for any misalignment sensed between the carriage and the shaft.

Delayed child-bearing.

Science.gov (United States)

Johnson, Jo-Ann; Tough, Suzanne

2012-01-01

To provide an overview of delayed child-bearing and to describe the implications for women and health care providers. Delayed child-bearing, which has increased greatly in recent decades, is associated with an increased risk of infertility, pregnancy complications, and adverse pregnancy outcome. This guideline provides information that will optimize the counselling and care of Canadian women with respect to their reproductive choices. Maternal age is the most important determinant of fertility, and obstetric and perinatal risks increase with maternal age. Many women are unaware of the success rates or limitations of assisted reproductive technology and of the increased medical risks of delayed child-bearing, including multiple births, preterm delivery, stillbirth, and Caesarean section. This guideline provides a framework to address these issues. Studies published between 2000 and August 2010 were retrieved through searches of PubMed and the Cochrane Library using appropriate key words (delayed child-bearing, deferred pregnancy, maternal age, assisted reproductive technology, infertility, and multiple births) and MeSH terms (maternal age, reproductive behaviour, fertility). The Internet was also searched using similar key words, and national and international medical specialty societies were searched for clinical practice guidelines and position statements. Data were extracted based on the aims, sample, authors, year, and results. The quality of evidence was rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care (Table 1). The Society of Obstetricians and Gynaecologists of Canada. RECOMMENDATIONS 1. Women who delay child-bearing are at increased risk of infertility. Prospective parents, especially women, should know that their fecundity and fertility begin to decline significantly after 32 years of age. Prospective parents should know that assisted reproductive technologies cannot guarantee a live birth or completely

Actuators for Active Magnetic Bearings

Directory of Open Access Journals (Sweden)

Eric H. Maslen

2017-10-01

Full Text Available The literature of active magnetic bearing (AMB technology dates back to at least 1937 when the earliest work that clearly describes an active magnetic bearing system was published by Jesse Beams [...

Positive correlation between decreased cellular uptake, NADPH-glutathione reductase activity and adriamycin resistance in Ehrlich ascites tumor lines.

Science.gov (United States)

Scheulen, M E; Hoensch, H; Kappus, H; Seeber, S; Schmidt, C G

1987-01-01

From a wild type strain of Ehrlich ascites tumor (EATWT) sublines resistant to daunorubicin (EATDNM), etoposide (EATETO), and cisplatinum (EATCIS) have been developed in vivo. Increase in survival and cure rate caused by adriamycin (doxorubicin) have been determined in female NMRI mice which were inoculated i.p. with EAT cells. Adriamycin concentrations causing 50% inhibition of 3H-thymidine (ICT) and 3H-uridine incorporation (ICU) and intracellular adriamycin steady-state concentrations (SSC) were measured in vitro. Adriamycin resistance increased and SSC decreased in the following sequence: EATWT - EATCIS - EATDNM - EATETO. When ICT and ICU were corrected for intracellular adriamycin concentrations in consideration of the different SSC (ICTc, ICUc), ICTc and ICUc still varied up to the 3.2 fold in EATCIS, EATDNM and EATETO in comparison to EATWT. Thus, in addition to different SSC other factors must be responsible for adriamycin resistance. Therefore, enzymes which may play a role in the cytotoxicity related to adriamycin metabolism (NADPH-cytochrome P-450 reductase, NADPH-glutathione reductase, NADP-glucose-6-phosphate dehydrogenase, NADP-isocitrate dehydrogenase) were measured. In contrast to the other parameters determined, NADPH-glutathione reductase was significantly (p less than 0.01) increased up to the 3.2 fold parallel to adriamycin resistance as determined by increase in life span, cure rate, ICTc, and ICUc, respectively. It is concluded that high activities of NADPH-glutathione reductase may contribute to an increase in adriamycin resistance of malignant tumors.

Effects of β-arabinofuranosyladenine on the growth and repair of potentially lethal damage in Ehrlich ascites tumor cells

International Nuclear Information System (INIS)

Iliakis, G.

1980-01-01

β-D-Arabinofuranosyladenine (β-araA) inhibit the growth of Ehrlich ascites tumor cells by selective inhibition of DNA polymerases. RNA and protein synthesis are not significantly affected. Addition of β-araA to the cells after irradiation resulted in a concentration-dependent decrease in survival, presumably due to the inhibition of the repair of potentially lethal damage. Since β-araA selectively inhibits DNA polymerases it is suggested that repair of potentially lethal damage involves steps at the DNA level which require some polymerization. These repair steps take place in the DNA with a velocity comparable to that of the repair of potentially lethal damage. The inhibition of the repair of potentially lethal damage by β-araA was modified by the addition of deoxyadenosine; this supports the finding that β-araA acts competitively against dATP at the molecular level. The inhibition of the repair of potentially lethal damage by β-araA, which is partly reversible, resulted in a concentration-dependent modification of the survival curve. At low concentrations of β-araA a dose-modifying decrease in survival was observed. At higher concentrations (more than 12 μM) the decrease in survival resulted in a decrease of the shoulder width of the survival curve. Eventually an exponential curve was obtained. We suggest therefore that the shoulder of the survival curve results from some repair or potentially lethal damage. Preliminary information has been obtained on the time course of this repair

Performance of gas-lubricated cruciform-mounted tilting-pad journal bearings and a damped flexibly mounted spiral-groove thrust bearing

Science.gov (United States)

Ream, L. W.

1974-01-01

A test program was conducted to determine the performance characteristics of gas-lubricated cruciform-mounted tilting-pad journal bearings and a damped spiral-groove thrust bearing designed for the Brayton cycle rotating unit (BRU). Hydrostatic, hybrid (simultaneously hydrostatic and hydrodynamic), and hydrodynamic tests were conducted in argon gas at ambient pressure and temperature ranges representative of operation to the 10.5 kWe BRU power-generating level. Performance of the gas lubricated bearings is presented including hydrostatic gas flow rates, bearing clearances, bearing temperatures, and transient performance.

14 CFR 23.623 - Bearing factors.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Bearing factors. 23.623 Section 23.623... Bearing factors. (a) Each part that has clearance (free fit), and that is subject to pounding or vibration, must have a bearing factor large enough to provide for the effects of normal relative motion. (b) For...

DW_BEAR

Data.gov (United States)

Department of Homeland Security — Subset of BEAR (Bi-Weekly Examination Analysis and Reporting) data used for financial audit remediation reporting within the Coast Guard Business Intelligence (CGBI)...

Bearing-Mounting Concept Accommodates Thermal Expansion

Science.gov (United States)

Nespodzany, Robert; Davis, Toren S.

1995-01-01

Pins or splines allow radial expansion without slippage. Design concept for mounting rotary bearing accommodates differential thermal expansion between bearing and any structure(s) to which bearing connected. Prevents buildup of thermal stresses by allowing thermal expansion to occur freely but accommodating expansion in such way not to introduce looseness. Pin-in-slot configuration also maintains concentricity.

Blade Bearing Friction Estimation of Operating Wind Turbines

DEFF Research Database (Denmark)

Perisic, Nevena; Pedersen, Bo Juul; Kirkegaard, Poul Henning

2012-01-01

Blade root bearing on a wind turbine (WTG) enables pitching of blades for power control and rotor braking and is a WTG critical component. As the size of modern WTGs is constantly increasing, this leads to relatively less rigid bearings, more sensitive to deformations, thus WTG operational...... reliability can be increased by continuous monitoring of blade bearing. High blade bearing friction is undesirable, as it may be associated with excessive heating of the surfaces, damage and/or inefficient operation. Thus, continuous observation of bearing friction level is crucial for blade bearing health...... monitoring systems. A novel algorithm for online monitoring of bearing friction level is developed combining physical knowledge about pitch system dynamics with state estimator, i.e. observer theory and signal processing assuming realistic sensor availability. Results show estimation of bearing friction...

Arsenic waste management: a critical review of testing and disposal of arsenic-bearing solid wastes generated during arsenic removal from drinking water.

Science.gov (United States)

Clancy, Tara M; Hayes, Kim F; Raskin, Lutgarde

2013-10-01

Water treatment technologies for arsenic removal from groundwater have been extensively studied due to widespread arsenic contamination of drinking water sources. Central to the successful application of arsenic water treatment systems is the consideration of appropriate disposal methods for arsenic-bearing wastes generated during treatment. However, specific recommendations for arsenic waste disposal are often lacking or mentioned as an area for future research and the proper disposal and stabilization of arsenic-bearing waste remains a barrier to the successful implementation of arsenic removal technologies. This review summarizes current disposal options for arsenic-bearing wastes, including landfilling, stabilization, cow dung mixing, passive aeration, pond disposal, and soil disposal. The findings from studies that simulate these disposal conditions are included and compared to results from shorter, regulatory tests. In many instances, short-term leaching tests do not adequately address the range of conditions encountered in disposal environments. Future research directions are highlighted and include establishing regulatory test conditions that align with actual disposal conditions and evaluating nonlandfill disposal options for developing countries.

The Dynamic Characteristic Analysis of the Water Lubricated Bearing-Rotor System in Seawater Desalination Pump

Directory of Open Access Journals (Sweden)

Xiaoyan Ye

2014-05-01

Full Text Available In order to study the water lubricated bearing-rotor system in seawater desalination pump, this paper is based on the coupling between the lubricating flow field and the rotor dynamics. The fluid-solid interaction (FSI method, Rigid Body, was adopted to study the journal orbit of the bearing-rotor system under the periodic unbalancing load. The influences of geometric and working parameter to the journal orbit were combined to analyze the stability and reliability of the bearing-rotor system. The result shows that increasing the rotating speed would increase the journal whirling amplitude and the system sensitivity to the external excitation and unbalancing load were promoted; increasing the aspect ratio would reduce the journal whirling amplitude and cause the system to be more unstable; increasing the inlet pressure would reduce the journal whirling amplitude and cause the system to be more unstable; increasing the unbalancing load would reduce the stability margin and the system is easy to be unstable if obstructed; increasing the radial clearance would reduce the journal whirling amplitude and cause the system to be more unstable. The attitude angle has no influence on the journal whirling amplitude but would influence the stability of system and the value of attitude angle should not be large.

The shared preference niche of sympatric Asiatic black bears and sun bears in a tropical forest mosaic.

Science.gov (United States)

Steinmetz, Robert; Garshelis, David L; Chutipong, Wanlop; Seuaturien, Naret

2011-01-20

Ecologically similar species often coexist by partitioning use of habitats or resources. Such partitioning can occur through divergent or shared niches. We investigated overlap in habitat use and spatial co-occurrence by sympatric Asiatic black bears and sun bears in three habitats in Thailand, and thereby assessed which niche model best accounts for their coexistence. We used density of species-specific signs to assess habitat use. Signs of both bear species occurred in all three habitats, and on >60% of sampling transects. Both species fed mostly on fruit; insect feeding signs were uncommon, and were mostly from sun bears. Significant differences in habitat use occurred only in montane forest, the habitat in which fruit was most abundant; incidence of black bear sign there was six times higher than that of sun bears. Habitat use was similar between the two species in the other habitats, which comprised 85% of the area. Of 10 habitat attributes examined, fruiting tree density was the best predictor of occurrence for both species. Models that included interspecific competition (fresh foraging activity of the other species) were less supported than the top models without competition. Bear species co-occurrence at both coarse and fine spatial scales and use of the same resources (fruit trees) indicated common niche preferences. However, their habitat use differed in ways expected from their physical differences: larger black bears dominated in the most fruit-rich habitat, and smaller sun bears used less-preferred insects. These results indicate broadly overlapping fundamental niches combined with asymmetric competition-features consistent with the concept of shared preference niches. This model of the niche has received little attention in ecology, but appears to be relatively common in nature.

The shared preference niche of sympatric Asiatic black bears and sun bears in a tropical forest mosaic.

Directory of Open Access Journals (Sweden)

Robert Steinmetz

2011-01-01

Full Text Available Ecologically similar species often coexist by partitioning use of habitats or resources. Such partitioning can occur through divergent or shared niches. We investigated overlap in habitat use and spatial co-occurrence by sympatric Asiatic black bears and sun bears in three habitats in Thailand, and thereby assessed which niche model best accounts for their coexistence.We used density of species-specific signs to assess habitat use. Signs of both bear species occurred in all three habitats, and on >60% of sampling transects. Both species fed mostly on fruit; insect feeding signs were uncommon, and were mostly from sun bears. Significant differences in habitat use occurred only in montane forest, the habitat in which fruit was most abundant; incidence of black bear sign there was six times higher than that of sun bears. Habitat use was similar between the two species in the other habitats, which comprised 85% of the area. Of 10 habitat attributes examined, fruiting tree density was the best predictor of occurrence for both species. Models that included interspecific competition (fresh foraging activity of the other species were less supported than the top models without competition.Bear species co-occurrence at both coarse and fine spatial scales and use of the same resources (fruit trees indicated common niche preferences. However, their habitat use differed in ways expected from their physical differences: larger black bears dominated in the most fruit-rich habitat, and smaller sun bears used less-preferred insects. These results indicate broadly overlapping fundamental niches combined with asymmetric competition-features consistent with the concept of shared preference niches. This model of the niche has received little attention in ecology, but appears to be relatively common in nature.

77 FR 59639 - Bear Lake National Wildlife Refuge, Bear Lake County, ID and Oxford Slough Waterfowl Production...

Science.gov (United States)

2012-09-28

... by 2020 to reduce the sedimentation rate of Bear River water diversions and to better exclude carp... sedimentation rate of Bear River water diversions and better exclude carp from Refuge wetlands. As in... DEPARTMENT OF THE INTERIOR Fish and Wildlife Service [FWS-R1-R-2012-N095; 1265-0000-10137-S3] Bear...

Rotor Rolling over a Water-Lubricated Bearing

Science.gov (United States)

Shatokhin, V. F.

2018-02-01

The article presents the results of studying the effect of forces associated with secondary damping coefficients (gyroscopic forces) on the development of asynchronous rolling of the rotor over a water-lubricated bearing. The damping forces act against the background of other exciting forces in the rotor-supports system, in particular, the exciting forces of contact interaction between the rotor and bearing. The article considers a rotor resting on supports rubbing against the bearing and the occurrence of self-excited vibration in the form of asynchronous roll-over. The rotor supports are made in the form of plain-type water-lubricated bearings. The plain-type bearing's lubrication stiffness and damping forces are determined using the wellknown algorithms taking into account the physical properties of water serving as lubrication of the bearing. The bearing sliding pair is composed of refractory materials. The lubrication layer in such bearings is thinner than that used in oil-lubricated bearings with white metal lining, and there is no white metal layer in waterlubricated bearings. In case of possible deviations from normal operation of the installation, the rotating rotor comes into direct contact with the liner's rigid body. Unsteady vibrations are modeled using a specially developed software package for calculating the vibration of rotors that rub against the turbine (pump) stator elements. The stiffness of the bearing liner with the stator support structure is specified by a dependence in the force-deformation coordinate axes. In modeling the effect of damping forces, the time moment corresponding to the onset of asynchronous rolling-over with growing vibration amplitudes is used as the assessment criterion. With a longer period of time taken for the rolling-over to develop, it becomes possible to take the necessary measures in response to actuation of the equipment set safety system, which require certain time for implementing them. It is shown that the

Rolling Bearing Life Prediction, Theory, and Application

Science.gov (United States)

Zaretsky, Erwin V.

2016-01-01

A tutorial is presented outlining the evolution, theory, and application of rolling-element bearing life prediction from that of A. Palmgren, 1924; W. Weibull, 1939; G. Lundberg and A. Palmgren, 1947 and 1952; E. Ioannides and T. Harris, 1985; and E. Zaretsky, 1987. Comparisons are made between these life models. The Ioannides-Harris model without a fatigue limit is identical to the Lundberg-Palmgren model. The Weibull model is similar to that of Zaretsky if the exponents are chosen to be identical. Both the load-life and Hertz stress-life relations of Weibull, Lundberg and Palmgren, and Ioannides and Harris reflect a strong dependence on the Weibull slope. The Zaretsky model decouples the dependence of the critical shear stress-life relation from the Weibull slope. This results in a nominal variation of the Hertz stress-life exponent. For 9th- and 8th-power Hertz stress-life exponents for ball and roller bearings, respectively, the Lundberg-Palmgren model best predicts life. However, for 12th- and 10th-power relations reflected by modern bearing steels, the Zaretsky model based on the Weibull equation is superior. Under the range of stresses examined, the use of a fatigue limit would suggest that (for most operating conditions under which a rolling-element bearing will operate) the bearing will not fail from classical rolling-element fatigue. Realistically, this is not the case. The use of a fatigue limit will significantly overpredict life over a range of normal operating Hertz stresses. (The use of ISO 281:2007 with a fatigue limit in these calculations would result in a bearing life approaching infinity.) Since the predicted lives of rolling-element bearings are high, the problem can become one of undersizing a bearing for a particular application. Rules had been developed to distinguish and compare predicted lives with those actually obtained. Based upon field and test results of 51 ball and roller bearing sets, 98 percent of these bearing sets had acceptable

Fractal analysis of polar bear hairs

Directory of Open Access Journals (Sweden)

Wang Qing-Li

2015-01-01

Full Text Available Hairs of a polar bear (Ursus maritimus are of superior properties such as the excellent thermal protection. Why do polar bears can resist such cold environment? The paper concludes that its fractal porosity plays an important role, and its fractal dimensions are very close to the golden mean, 1.618, revealing the possible optimal structure of polar bear hair.

Removable bearing arrangement for a wind turbine generator

Science.gov (United States)

Bagepalli, Bharat Sampathkumaran; Jansen, Patrick Lee; Gadre, Aniruddha Dattatraya

2010-06-15

A wind generator having removable change-out bearings includes a rotor and a stator, locking bolts configured to lock the rotor and stator, a removable bearing sub-assembly having at least one shrunk-on bearing installed, and removable mounting bolts configured to engage the bearing sub-assembly and to allow the removable bearing sub-assembly to be removed when the removable mounting bolts are removed.

Technology development for indigenous water lubricated bearings

International Nuclear Information System (INIS)

Limaye, P.K.; Soni, N.L.; Agrawal, R.G.

2010-01-01

Water Lubricated Bearings (WLB) are used in various mechanisms of fuel handling systems of PHWRs and AHWR. Availability and random failures of these bearings was a major factor in refuelling operations. Indigenous development of these bearings was taken up and 7 types of antifriction bearings in various sizes (totaling 37 variants) for PHWR, AHWR and Dhruva applications were successfully developed. This paper deals with various aspects of WLB development. (author)

Morphology and Hardness Improvement of Lead Bearing Alloy through Composite Production: 75Pb-15Sb-10Sn/ 15% V/V SiO2 Particulate Composite

Directory of Open Access Journals (Sweden)

Linus Okon ASUQUO

2013-06-01

Full Text Available The morphology and hardness improvement of lead bearing alloy through composite production: 75Pb-15Sb-10Sn/ 15%v/v SiO2 particulate composite, was studied. 75Pb-15Sb-10Sn white bearing alloy produced at the foundry shop of National Metallurgical Development Centre Jos was used for the production of the composite using stir-cast method. The reinforcing agent was 63 microns passing particles of silica. This was produced from pulverizing quartz using laboratory ball mill. The specimens of the composite produced were then subjected to metallographic to study the morphology of the structures produced both in the as cast and aged conditions of the composite. The samples were also tested for hardness and the result showed that the as cast composite had a hardness value of 33 HRB which is an improvement over the hardness value of 27.7 HRB for the 75Pb-15Sb-10Sn alloy which was used for the production of the composite. The effect of age hardening on the produced composite was also investigated; the result showed that the maximum hardness of 34 HRB was obtained after ageing for 3 hours. The micrographs revealed inter-metallic compound SbSn, eutectic of two solid solutions-one tin-rich and the other lead-rich, reinforcing particles, and solid solution of β. The results revealed that particle hardening can be used to improve the hardness of 75Pb-15Sb-10Sn white bearing alloy for use as heavy duty bearing material.

Increase of radioinduced chromosome damage by products regularly used as contrast media in radiographs

International Nuclear Information System (INIS)

Santos-Mello, R.

1982-01-01

Results are described of various experiments aiming to verify the correlation between genetic damage (chromosome aberrations) and the use of energy sources of several intensities (X-rays: 100, 125 and 250kVP; 60 Co) in conjunction with some radiopaque substances during radiographic procedures. The first attempt to employ the Hypaque - X-ray association in the treatment of Ehrlich solid tumors in SW-40 mice is described. (M.A.) [pt

Local Attitudes towards Bear Management after Illegal Feeding and Problem Bear Activity

OpenAIRE

David Fraser; Sara Dubois

2013-01-01

Simple Summary The “pot bears” received international media attention in 2010 after police discovered the intentional feeding of black bears during the investigation of an alleged marijuana-growing operation in Christina Lake, British Columbia. Residents of this small community were surveyed by phone twice over the following year, before and after government actions. This study aimed to understand local attitudes on how these bears should be managed and whether they differed from existing bea...

Uranium-bearing wastes and their radon emanation

International Nuclear Information System (INIS)

Sasaki, Tomozo; Imamura, Mitsutaka; Gunji, Yasuyoshi

2007-01-01

There are no data available with regard to radon emanation coefficients for uranium-bearing wastes; such data are needed for the assessment of radiation exposure from radon that will be generated in the distant future as one uranium progeny at shallow land disposal sites for uranium-bearing wastes. There are many kinds of uranium-bearing wastes. However, it is not necessary to measure the radon emanation coefficients for all of them for two reasons. First, the radon emanation coefficients for uranium-bearing wastes contaminated by dissolved uranium are determined by the uranium chemical form, the manner of uranium deposition on the waste matrix, and the size of the particles which constitute the waste matrix. Therefore, only a few representative measurements are sufficient for such uranium-bearing wastes. Second, it is possible to make theoretical calculations of radon emanation coefficients for uranium-bearing wastes contaminated by UO 2 particles before sintering. In the present study, simulated uranium-bearing wastes contaminated by dissolved uranium were prepared, their radon emanation coefficients were measured and radon emanation coefficients were calculated theoretically for uranium-bearing wastes contaminated by UO 2 particles before sintering. The obtained radon emanation coefficients are distributed at higher values than those for ubiquitous soils and rocks in the natural environment. Therefore, it is not correct to just compare uranium concentrations among uranium-bearing wastes, ubiquitous soils and rocks in terms of radiation exposure. The radon emanation coefficients obtained in the present study have to be employed together with the uranium concentration in uranium-bearing wastes in order to achieve proper assessment of radiation exposure. (author)

Failure of GIMBAL bearing in directional GYRO

International Nuclear Information System (INIS)

Pervaiz, R.; Baig, N.A.; Shahid, M.; Ahmad, A.; Chohan, G.Y.

2003-01-01

This paper relates to the directional gyro of a sensing device used in indigenously developed surface-to-surface missile. The assembling of more than one thousand components in the form of several sub assemblies including hundreds of silver solders of this device was done in the hundred-thousands-class clean room according to assembly procedure. Whereas more than twenty bearings including gimbals bearings were assembled in the ten-thousands-class clean room after inspection/ testing them on beating testing system as per routine. The device was entered in testing and adjustment phase after successful completion of assembly work. The directional gyro qualified all the tests except the most critical one, the drift-rate. The drift-rate of outer gimbal was 60% more than permissible limit whereas drift-rate of inner gimbal was found O.K. It was diagnosed that at least one inner gimbal bearing out of two had some problem. The results were same after rebalancing of gimbals three times. The directional gyro was disassembled in clean room and the radial-thrust-bearing was recovered and flange bearing which are inner gimbal bearings. They were checked on bearing testing system and it was found that flange-bearing had more friction than permissible limit and hence rejected but radial thrust bearing were declared O.K. The gyro was reassembled with new O.K. flange bearing and the assembly work was completed in all respects. The sensing device qualified all the tests including the drift-rate. This case study is being presented to emphasize the importance of careful assembly of gyro in clean environment. (author)

Bearing life in contaminated oil and oil passing into bearing for tapered roller bearing; Ensui koro jikuuke ni okeru ibutsu yuchu deno jumyo to kantsu yuryo

Energy Technology Data Exchange (ETDEWEB)

Asai, Y; Oshima, H; Sakamoto, K [Koyo Seiko Co. Ltd., Osaka (Japan)

1997-10-01

In this paper a relationship between depth of dents, area of dents gathered and bearing life has been investigated for tapered roller bearings used in differential gear case. It is effective for the longer bearing life to reduce hard particles of Fe especially among several contaminations existing in the gear case. It is also effective to make oil level lower in the case from the view point for reduction of number of dents. 8 refs., 8 figs., 4 tabs.

Grizzly bears and mining in the Cheviot region

Energy Technology Data Exchange (ETDEWEB)

Symbaluk, M.; Archibald, T. [Foothills Research Inst., Hinton, AB (Canada)

2008-07-01

This presentation described a grizzly bear research program conducted by the Foothill Research Institute at the Cheviot mine. The research program uses a satellite land classification protocol and remote sensing tools to map and identify the grizzly bear habitat. Modelling is also conducted to predict bear probabilities. Global information systems (GIS) are used to evaluate bear responses to human activities. Grizzly bear health and wellness is also assessed as part of the programs. Land maps are combined with global positioning systems (GPS) and resource selection function (RSF) models in order to map grizzly bear distribution. Data obtained from the program is used to inform decision-making and support policy development. Previous studies predicted that the grizzly bear population would disappear from the Cheviot mine area after 20 years of its being in operation. The research program provided real data to test predictions made during previous environmental assessments. Grizzly bear populations have actually increased in the mining area. It was concluded that the bears have moved more freely through industrial landscapes than previously predicted. tabs., figs.

Ball Bearing Analysis with the ORBIS Tool

Science.gov (United States)

Halpin, Jacob D.

2016-01-01

Ball bearing design is critical to the success of aerospace mechanisms. Key bearing performance parameters, such as load capability, stiffness, torque, and life all depend on accurate determination of the internal load distribution. Hence, a good analytical bearing tool that provides both comprehensive capabilities and reliable results becomes a significant asset to the engineer. This paper introduces the ORBIS bearing tool. A discussion of key modeling assumptions and a technical overview is provided. Numerous validation studies and case studies using the ORBIS tool are presented. All results suggest the ORBIS code closely correlates to predictions on bearing internal load distributions, stiffness, deflection and stresses.

Superconducting bearings for flywheel applications

DEFF Research Database (Denmark)

Abrahamsen, A.B.

2001-01-01

A literature study on the application of superconducting bearings in energy storage flywheel systems. The physics of magnetic levitation and superconductors are presented in the first part of the report, followed by a discussion of the literature found onthe applications of superconducting bearings...

Stochasticity in Natural Forage Production Affects Use of Urban Areas by Black Bears: Implications to Management of Human-Bear Conflicts

Science.gov (United States)

Baruch-Mordo, Sharon; Wilson, Kenneth R.; Lewis, David L.; Broderick, John; Mao, Julie S.; Breck, Stewart W.

2014-01-01

The rapid expansion of global urban development is increasing opportunities for wildlife to forage and become dependent on anthropogenic resources. Wildlife using urban areas are often perceived dichotomously as urban or not, with some individuals removed in the belief that dependency on anthropogenic resources is irreversible and can lead to increased human-wildlife conflict. For American black bears (Ursus americanus), little is known about the degree of bear urbanization and its ecological mechanisms to guide the management of human-bear conflicts. Using 6 years of GPS location and activity data from bears in Aspen, Colorado, USA, we evaluated the degree of bear urbanization and the factors that best explained its variations. We estimated space use, activity patterns, survival, and reproduction and modeled their relationship with ecological covariates related to bear characteristics and natural food availability. Space use and activity patterns were dependent on natural food availability (good or poor food years), where bears used higher human density areas and became more nocturnal in poor food years. Patterns were reversible, i.e., individuals using urban areas in poor food years used wildland areas in subsequent good food years. While reproductive output was similar across years, survival was lower in poor food years when bears used urban areas to a greater extent. Our findings suggest that bear use of urban areas is reversible and fluctuates with the availability of natural food resources, and that removal of urban individuals in times of food failures has the potential to negatively affect bear populations. Given that under current predictions urbanization is expected to increase by 11% across American black bear range, and that natural food failure years are expected to increase in frequency with global climate change, alternative methods of reducing urban human-bear conflict are required if the goal is to prevent urban areas from becoming population sinks

Stochasticity in natural forage production affects use of urban areas by black bears: implications to management of human-bear conflicts.

Directory of Open Access Journals (Sweden)

Sharon Baruch-Mordo

Full Text Available The rapid expansion of global urban development is increasing opportunities for wildlife to forage and become dependent on anthropogenic resources. Wildlife using urban areas are often perceived dichotomously as urban or not, with some individuals removed in the belief that dependency on anthropogenic resources is irreversible and can lead to increased human-wildlife conflict. For American black bears (Ursus americanus, little is known about the degree of bear urbanization and its ecological mechanisms to guide the management of human-bear conflicts. Using 6 years of GPS location and activity data from bears in Aspen, Colorado, USA, we evaluated the degree of bear urbanization and the factors that best explained its variations. We estimated space use, activity patterns, survival, and reproduction and modeled their relationship with ecological covariates related to bear characteristics and natural food availability. Space use and activity patterns were dependent on natural food availability (good or poor food years, where bears used higher human density areas and became more nocturnal in poor food years. Patterns were reversible, i.e., individuals using urban areas in poor food years used wildland areas in subsequent good food years. While reproductive output was similar across years, survival was lower in poor food years when bears used urban areas to a greater extent. Our findings suggest that bear use of urban areas is reversible and fluctuates with the availability of natural food resources, and that removal of urban individuals in times of food failures has the potential to negatively affect bear populations. Given that under current predictions urbanization is expected to increase by 11% across American black bear range, and that natural food failure years are expected to increase in frequency with global climate change, alternative methods of reducing urban human-bear conflict are required if the goal is to prevent urban areas from

Stochasticity in natural forage production affects use of urban areas by black bears: implications to management of human-bear conflicts.

Science.gov (United States)

Baruch-Mordo, Sharon; Wilson, Kenneth R; Lewis, David L; Broderick, John; Mao, Julie S; Breck, Stewart W

2014-01-01

The rapid expansion of global urban development is increasing opportunities for wildlife to forage and become dependent on anthropogenic resources. Wildlife using urban areas are often perceived dichotomously as urban or not, with some individuals removed in the belief that dependency on anthropogenic resources is irreversible and can lead to increased human-wildlife conflict. For American black bears (Ursus americanus), little is known about the degree of bear urbanization and its ecological mechanisms to guide the management of human-bear conflicts. Using 6 years of GPS location and activity data from bears in Aspen, Colorado, USA, we evaluated the degree of bear urbanization and the factors that best explained its variations. We estimated space use, activity patterns, survival, and reproduction and modeled their relationship with ecological covariates related to bear characteristics and natural food availability. Space use and activity patterns were dependent on natural food availability (good or poor food years), where bears used higher human density areas and became more nocturnal in poor food years. Patterns were reversible, i.e., individuals using urban areas in poor food years used wildland areas in subsequent good food years. While reproductive output was similar across years, survival was lower in poor food years when bears used urban areas to a greater extent. Our findings suggest that bear use of urban areas is reversible and fluctuates with the availability of natural food resources, and that removal of urban individuals in times of food failures has the potential to negatively affect bear populations. Given that under current predictions urbanization is expected to increase by 11% across American black bear range, and that natural food failure years are expected to increase in frequency with global climate change, alternative methods of reducing urban human-bear conflict are required if the goal is to prevent urban areas from becoming population sinks.

Characterization and measurement of hybrid gas journal bearings

Science.gov (United States)

Lawrence, Tom Marquis

This thesis concentrates on the study of hybrid gas journal bearings (bearings with externally pressurized mass addition). It differs from most work in that it goes back to "basics" to explore the hydrodynamic phenomena in the bearing gap. The thesis compares geometrically identical bearings with 2 configurations of external pressurization, porous liners where mass-addition compensation is varied by varying the liner's permeability, and bushings with 2 rows of 6 feedholes where the mass-addition compensation is varied by the feedhole diameter. Experimentally, prototype bearings with mass-addition compensation that spans 2 orders of magnitude with differing clearances are built and their aerostatic properties and mass addition characteristics are thoroughly tested. The fundamental equations for compressible, laminar, Poiseuille flow are used to suggest how the mass flow "compensation" should be mathematically modeled. This is back-checked against the experimental mass flow measurements and is used to determine a mass-addition compensation parameter (called Kmeas) for each prototype bushing. In so doing, the methodology of modeling and measuring the mass addition in a hybrid gas bearing is re-examined and an innovative, practical, and simple method is found that makes it possible to make an "apples-to-apples" comparison between different configurations of external pressurization. This mass addition model is used in conjunction with the Reynolds equation to perform theory-based numerical analysis of virtual hybrid gas journal bearings (CFD experiments). The first CFD experiments performed use virtual bearings modeled to be identical to the experimental prototypes and replicate the experimental work. The results are compared and the CFD model is validated. The ontological significance of appropriate dimensionless similitude parameters is re-examined and a, previously lacking, complete set of similitude factors is found for hybrid bearings. A new practical method is

Assessing bear-human conflicts in the Yukon Territory

OpenAIRE

Lukie, Raechel Dawn

2010-01-01

Managing conflicts between bears and humans is vital for human safety and for the conservation of bears. This study investigated black bear (Ursus americanus) and grizzly bear (Ursus arctos) interactions with humans in 18 major communities of the Yukon Territory. I used an information theoretic approach to generate predictive models of the relative potential of bear-human interaction for the 9 conservation officer management regions in the Yukon Territory. I independently modeled interactions...

77 FR 77070 - Black Bear Hydro Partners, LLC;

Science.gov (United States)

2012-12-31

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 2727-086] Black Bear Hydro...: October 24, 2012. d. Submitted By: Black Bear Hydro Partners, LLC (Black Bear Hydro). e. Name of Project... designating Black Bear Hydro as the Commission's non-federal representative for carrying out informal...

Enhanced antitumor efficacy of cisplatin in combination with HemoHIM in tumor-bearing mice

Directory of Open Access Journals (Sweden)

Kim Sung-Ho

2009-03-01

Full Text Available Abstract Background Although cisplatin is one of the most effective chemotherapeutic agents, cisplatin alone does not achieve a satisfactory therapeutic outcome. Also cisplatin accumulation shows toxicity to normal tissues. In this study, we examined the possibility of HemoHIM both to enhance anticancer effect with cisplatin and to reduce the side effects of cisplatin in melanoma-bearing mice. Methods HemoHIM was prepared by adding the ethanol-insoluble fraction to the total water extract of a mixture of 3 edible herbs, Angelica Radix, Cnidium Rhizoma and Paeonia Radix. Anticancer effects of HemoHIM with cisplatin were evaluated in melanoma-bearing mice. We used a Cr51-release assay to measure the activity of NK/Tc cell and ELISA to evaluate the production of cytokines. Results In melanoma-bearing mice, cisplatin (4 mg/kg B.W. reduced the size and weight of the solid tumors, and HemoHIM supplementation with cisplatin enhanced the decrease of both the tumor size (p in vitro, and did not disturb the effects of cisplatin in vitro. However HemoHIM administration enhanced both NK cell and Tc cell activity in mice. Interestingly, HemoHIM increased the proportion of NK cells in the spleen. In melanoma-bearing mice treated with cisplatin, HemoHIM administration also increased the activity of NK cells and Tc cells and the IL-2 and IFN-γ secretion from splenocytes, which seemed to contribute to the enhanced efficacy of cisplatin by HemoHIM. Also, HemoHIM reduced nephrotoxicity as seen by tubular cell of kidney destruction. Conclusion HemoHIM may be a beneficial supplement during cisplatin chemotherapy for enhancing the anti-tumor efficacy and reducing the toxicity of cisplatin.

Effects of exotic species on Yellowstone's grizzly bears

Science.gov (United States)

Reinhart, Daniel P.; Haroldson, Mark A.; Mattson, D.J.; Gunther, Kerry A.

2001-01-01

Humans have affected grizzly bears (Ursus arctos horribilis) by direct mortality, competition for space and resources, and introduction of exotic species. Exotic organisms that have affected grizzly bears in the Greater Yellowstone Area include common dandelion (Taraxacum officinale), nonnative clovers (Trifolium spp.), domesticated livestock, bovine brucellosis (Brucella abortus), lake trout (Salvelinus namaycush), and white pine blister rust (Cronartium ribicola). Some bears consume substantial amounts of dandelion and clover. However, these exotic foods provide little digested energy compared to higher-quality bear foods. Domestic livestock are of greater energetic value, but use of this food by bears often leads to conflicts with humans and subsequent increases in bear mortality. Lake trout, blister rust, and brucellosis diminish grizzly bears foods. Lake trout prey on native cutthroat trout (Oncorhynchus clarkii) in Yellowstone Lake; white pine blister rust has the potential to destroy native whitebark pine (Pinus albicaulis) stands; and management response to bovine brucellosis, a disease found in the Yellowstone bison (Bison bison) and elk (Cervus elaphus), could reduce populations of these 2 species. Exotic species will likely cause more harm than good for Yellowstone grizzly bears. Managers have few options to mitigate or contain the impacts of exotics on Yellowstone's grizzly bears. Moreover, their potential negative impacts have only begun to unfold. Exotic species may lead to the loss of substantial highquality grizzly bear foods, including much of the bison, trout, and pine seeds that Yellowstone grizzly bears currently depend upon.

Research In Diagnosing Bearing Defects From Vibrations

Science.gov (United States)

Zoladz, T.; Earhart, E.; Fiorucci, T.

1995-01-01

Report describes research in bearing-defect signature analysis - use of vibration-signal analysis to diagnose defects in roller and ball bearings. Experiments performed on bearings in good condition and other bearings in which various parts scratched to provide known defects correlated with vibration signals. Experiments performed on highly instrumented motor-driven rotor assembly at speeds up to 10,050 r/min, using accelerometers, velocity probes, and proximity sensors mounted at various locations on assembly to measure vibrations.

The Biotribology of PEEK-on-HXLPE Bearings Is Comparable to Traditional Bearings on a Multidirectional Pin-on-disk Tester.

Science.gov (United States)

Baykal, Doruk; Siskey, Ryan S; Underwood, Richard J; Briscoe, Adam; Kurtz, Steven M

2016-11-01

All-polymer bearings involving polyetheretherketone (PEEK) have been proposed for orthopaedic applications because they may reduce stress shielding, reduce weight of the implants, reduce wear and risk of osteolysis, and prevent release of metal ions by replacing the metal articulating components. Little is known about the biotribology of all-polymer PEEK bearings, including the effects of cross-shear, which are relevant for implant longevity, especially in the hip, and increased temperature that may affect lubricant proteins and, hence, lubrication in the joint. Using pin-on-disk in vitro testing, we asked: (1) Can all-polymer bearing couples involving PEEK have a comparable or lower wear rate than highly crosslinked UHMWPE (HXLPE) on CoCr bearing couples? (2) Is the wear rate of PEEK bearing couples affected by the amount of cross-shear? (3) Is there a difference in wear mechanism and surface morphology for all-polymer bearing surfaces compared with UHMWPE (HXLPE) on CoCr? We simultaneously tested a total of 100 pin-on-disk couples (n = 10 per bearing couple) consisting of three traditional metal-on-UHMWPE and seven polymer-on-polymer bearings for 2 million cycles under physiologically relevant conditions and in accordance with ASTM F732. Using analysis of variance, we analyzed the effect of bearing surface topography and cross-shear on wear rate. The changes in surface topography were evaluated using optical microscopy. Sample size was sufficient to provide 80% power to detect a difference of 1.4 mm 3 /MC in average wear rates of bearing couples. The combined wear rates of all-polymer bearing couples were not different than traditional bearing couples. With the numbers available, the PEEK and HXLPE bearing couple had a mean wear rate (WR: mean ± SD) of 0.9 ± 1.1 mm 3 /MC (95% confidence interval [CI], 0.2-1.5 mm 3 /MC), which was not different than the wear rate of the CoCr and HXLPE bearing couple (1.6 ± 2.0 mm 3 /MC; 95% CI, 0.4-2.8 mm 3 /MC; mean difference

Bearing assemblies, apparatuses, and motor assemblies using the same

Science.gov (United States)

Sexton, Timothy N.; Cooley, Craig H.; Knuteson, Cody W.

2015-12-29

Various embodiments of the invention relate to bearing assemblies, apparatuses and motor assemblies that include geometric features configured to impart a selected amount of heat transfer and/or hydrodynamic film formation. In an embodiment, a bearing assembly may include a plurality of superhard bearing pads distributed circumferentially about an axis. At least some of the plurality of superhard bearing pads may include a plurality of sub-superhard bearing elements defining a bearing surface. At least some of the plurality of sub-superhard bearing elements may be spaced from one another by one or more voids to impart a selected amount of heat transfer and hydrodynamic film formation thereon during operation. The bearing assembly may also include a support ring that carries the plurality of superhard bearing pads. In addition, at least a portion of the sub-superhard bearing elements may extend beyond the support ring.

Vertically loaded pivot bearing for high-speed shafts

International Nuclear Information System (INIS)

Zippe, G.; Werner, D.; Keller, A.; Stephan, E.

1974-01-01

The pivot bearing subjected to vertical loads has a pivot with a rounded end and a diametral slot and a cup-shaped recess in the bearing box. The end of the pivot and the recess constitute a gap which widens towards the periphery of the bearing. The bearing box carries an attachment with a clearance, the shape of a hollow cylinder and accomodating the pivot and its shaft. To feed the lubricating oil surrounding and filling the bearing there is a groove either in the wall of the clearance or at the end of the pivot in the direction of rotation of the shaft or against it. The oil carried to the support point flows back into the oil bath surrounding the bearing through a slot in the bearing box. (DG) [de

Non-Weight-Bearing and Weight-Bearing Ultrasonography of Select Foot Muscles in Young, Asymptomatic Participants: A Descriptive and Reliability Study.

Science.gov (United States)

Battaglia, Patrick J; Mattox, Ross; Winchester, Brett; Kettner, Norman W

The primary aim of this study was to determine the reliability of diagnostic ultrasound imaging for select intrinsic foot muscles using both non-weight-bearing and weight-bearing postures. Our secondary aim was to describe the change in muscle cross-sectional area (CSA) and dorsoplantar thickness when bearing weight. An ultrasound examination was performed with a linear ultrasound transducer operating between 9 and 12 MHz. Long-axis and short-axis ultrasound images of the abductor hallucis, flexor digitorum brevis, and quadratus plantae were obtained in both the non-weight-bearing and weight-bearing postures. Two examiners independently collected ultrasound images to allow for interexaminer and intraexaminer reliability calculation. The change in muscle CSA and dorsoplantar thickness when bearing weight was also studied. There were 26 participants (17 female) with a mean age of 25.5 ± 3.8 years and a mean body mass index of 28.0 ± 7.8 kg/m 2 . Inter-examiner reliability was excellent when measuring the muscles in short axis (intraclass correlation coefficient >0.75) and fair to good in long axis (intraclass correlation coefficient >0.4). Intraexaminer reliability was excellent for the abductor hallucis and flexor digitorum brevis and ranged from fair to good to excellent for the quadratus plantae. Bearing weight did not reduce interexaminer or intraexaminer reliability. All muscles exhibited a significant increase in CSA when bearing weight. This is the first report to describe weight-bearing diagnostic ultrasound of the intrinsic foot muscles. Ultrasound imaging is reliable when imaging these muscles bearing weight. Furthermore, muscle CSA increases in the weight-bearing posture. Copyright © 2016. Published by Elsevier Inc.

Eastern slopes grizzly bear project : project update

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-01-01

This report updates a study to examine the cumulative effects of human activities on the grizzly bears in the central Canadian Rockies. The project was initiated in 1994 to acquire accurate scientific information on the habitat and populations of grizzly bears in the area of the Banff National Park and Kananaskis Country. This area is probably the most heavily used and developed area where the grizzly still survives. The information gathered throughout the course of the study is used to better protect and manage the bears and other sensitive carnivores in the region. Using telemetry, researchers monitored 25 grizzly bears which were radio-collared in a 22,000 square-kilometer area in the upper Bow Valley drainage of the eastern Alberta slopes. The researchers worked with representatives from Husky Oil and Rigel Energy on the development of the Moose Mountain oil and gas field without adversely affecting the grizzly bear population. Information collected over eight years indicates that the grizzly bears have few and infrequent offspring. Using the information gathered thus far, the location of the Moose Mountain to Jumping Pound pipeline was carefully selected, since the bears suffer from high mortality, and the food and cover had already been compromised by the high number of roads, trails and other human activities in the area. The research concluded in November 2001 provides sufficient information to accurately asses the status of the grizzly bear population and habitat. The data will be analyzed and integrated in 2002 into models that reflect the variables affecting grizzly bears and a final report will be published.

Nonlinear Dynamic Response of Compliant Journal Bearings

Directory of Open Access Journals (Sweden)

Glavatskih S.

2012-07-01

Full Text Available This paper investigates the dynamic response of the compliant tilting pad journal bearings subjected to synchronous excitation. Bearing compliance is affected by the properties of pad liner and pad support geometry. Different unbalance eccentricities are considered. It is shown that bearing dynamic response is non-linear. Journal orbit complexity increases with pad compliance though the orbit amplitudes are marginally affected at low loads. At high loads, the journal is forced to operate outside the bearing clearance. The polymer liner reduces the maximum oil film pressure by a factor of 2 when compared to the white metal liner. The nonlinear dynamic response of compliant tilting pad journal bearings is thoroughly discussed.

Grizzly bear density in Glacier National Park, Montana

Science.gov (United States)

Kendall, K.C.; Stetz, J.B.; Roon, David A.; Waits, L.P.; Boulanger, J.B.; Paetkau, David

2008-01-01

We present the first rigorous estimate of grizzly bear (Ursus arctos) population density and distribution in and around Glacier National Park (GNP), Montana, USA. We used genetic analysis to identify individual bears from hair samples collected via 2 concurrent sampling methods: 1) systematically distributed, baited, barbed-wire hair traps and 2) unbaited bear rub trees found along trails. We used Huggins closed mixture models in Program MARK to estimate total population size and developed a method to account for heterogeneity caused by unequal access to rub trees. We corrected our estimate for lack of geographic closure using a new method that utilizes information from radiocollared bears and the distribution of bears captured with DNA sampling. Adjusted for closure, the average number of grizzly bears in our study area was 240.7 (95% CI = 202–303) in 1998 and 240.6 (95% CI = 205–304) in 2000. Average grizzly bear density was 30 bears/1,000 km2, with 2.4 times more bears detected per hair trap inside than outside GNP. We provide baseline information important for managing one of the few remaining populations of grizzlies in the contiguous United States.

Research on Bored Bearing Characteristics in Xi’an

Directory of Open Access Journals (Sweden)

Zhang Lipeng

2015-01-01

Full Text Available To analyze the influence of different soil properties on pile foundation load-bearing characteristics, taking a section of railway in Xi’an and a bridge of Xi’an as test area, and by field static load test to study load transfer characteristics after the test piles under axial pressure, including the distribution of axial force, pile lateral friction, tip resistance traits, ultimate bearing capacity determine, and compare with the theory bearing capacity. Experimental results show that, adjacent soil properties change large, axial force and lateral friction mutation at the junction of corresponding soil layer. Silty clay in different parts is below ground, and its lateral friction plays much difference. Pile lateral friction plays an important role in bearing capacity, but the role of round gravel soil end bearing capacity to pile bearing capacity can’t be ignored. Tests calculate pile bearing capacity significantly larger than standardized formula calculation bearing capacity, which are respectively 55.35% and 119.1%. And give the similar project condition the suggested values of pile bearing capacity and soil friction, to provide reference for similar pile foundation design.

On the future of controllable fluid film bearings

DEFF Research Database (Denmark)

Santos, Ilmar

2011-01-01

lubrication regimes, i.e., as tilting-pad journal bearings, multi-recess journal bearings and plain journal bearings. After a comprehensive overview of the theoretical and experimental technological advancements achieved in university laboratories, the feasibility of industrial applications is highlighted......This work gives an overview of the theoretical and experimental achievements of mechatronics applied to fluid film bearings. Compressible and uncompressible fluids are addressed. Rigid and elastic (deformable) bearing profiles are investigated. Hydraulic, pneumatic, magnetic and piezoelectric...

Hard Chrome-Coated and Fullerene-Doped Metal Surfaces in Orthopedic Bearings.

Science.gov (United States)

Sonntag, Robert; Feige, Katja; Dos Santos, Claudia Beatriz; Kretzer, Jan Philippe

2017-12-20

Metal-on-metal bearings for total hip replacements have been introduced as an alternative to polyethylene in young and more active patients. These have, however, been shown to be prone to implant malpositioning and have been limited by some specific design features. In that context, coatings present an option to increase wear resistance by keeping the high fracture strength of the metal substrate. A custom-made electroplating setup was designed for the coating of CoCr substrates using (a) an industrial standard chromium electrolyte; (b) a custom-made hexavalent chromium (Cr 6+ ) electrolyte with a reduced chromium trioxide (CrO₃) content, both without solid additives and (c) with the addition of fullerene (C 60 ) nanoparticles; and (d) a trivalent chromium (Cr 3+ ) electrolyte with C 60 addition. All coatings showed an increase in microhardness compared with the metal substrate. Trivalent coatings were thinner (10 µm) than the hexavalent coatings (23-40 µm) and resulted in increased roughness and crack density. Wear was found to be reduced for the hexavalent chromium coatings by 70-84% compared with the CoCr-CoCr reference bearing while the trivalent chromium coating even increased wear by more than 300%. The addition of fullerenes to the electrolyte did not show any further tribological effect.

Hard Chrome-Coated and Fullerene-Doped Metal Surfaces in Orthopedic Bearings

Directory of Open Access Journals (Sweden)

Robert Sonntag

2017-12-01

Full Text Available Metal-on-metal bearings for total hip replacements have been introduced as an alternative to polyethylene in young and more active patients. These have, however, been shown to be prone to implant malpositioning and have been limited by some specific design features. In that context, coatings present an option to increase wear resistance by keeping the high fracture strength of the metal substrate. A custom-made electroplating setup was designed for the coating of CoCr substrates using (a an industrial standard chromium electrolyte; (b a custom-made hexavalent chromium (Cr6+ electrolyte with a reduced chromium trioxide (CrO3 content, both without solid additives and (c with the addition of fullerene (C60 nanoparticles; and (d a trivalent chromium (Cr3+ electrolyte with C60 addition. All coatings showed an increase in microhardness compared with the metal substrate. Trivalent coatings were thinner (10 µm than the hexavalent coatings (23–40 µm and resulted in increased roughness and crack density. Wear was found to be reduced for the hexavalent chromium coatings by 70–84% compared with the CoCr–CoCr reference bearing while the trivalent chromium coating even increased wear by more than 300%. The addition of fullerenes to the electrolyte did not show any further tribological effect.

Superconducting bearings for flywheel applications

Energy Technology Data Exchange (ETDEWEB)

Abrahamsen, Asger Bech

2001-05-01

A literature study on the application of superconducting bearings in energy storage flywheel systems. The physics of magnetic levitation and superconductors are presented in the first part of the report, followed by a discussion of the literature found on the applications of superconducting bearings in flywheels. (au)

Wear numbers for ball cup and journal bearings

NARCIS (Netherlands)

Ligterink, D.J.; Moes, H.

1980-01-01

A wear number is defined for ball cup bearings and for journal bearings where the cup and the cylindrical bearing are made of soft material. This dimensionless wear number provides a relation between the following five quantities: the radius of the ball or the length of the journal bearing in

Comparison of High-Flexion Fixed-Bearing and High-Flexion Mobile-Bearing Total Knee Arthroplasties-A Prospective Randomized Study.

Science.gov (United States)

Kim, Young-Hoo; Park, Jang-Won; Kim, Jun-Shik

2018-01-01

There is none, to our knowledge, about comparison of high-flexion fixed-bearing and high-flexion mobile-bearing total knee arthroplasties (TKAs) in the same patients. The purpose of this study was to determine whether clinical results; radiographic and computed tomographic scan results; and the survival rate of a high-flexion mobile-bearing TKA is better than that of a high-flexion fixed-bearing TKA. The present study consisted of 92 patients (184 knees) who underwent same-day bilateral TKA. Of those, 17 were men and 75 were women. The mean age at the time of index arthroplasty was 61.5 ± 8.3 years (range 52-65 years). The mean body mass index was 26.2 ± 3.3 kg/m 2 (range 23-34 kg/m 2 ). The mean follow-up was 11.2 years (range 10-12 years). The Knee Society knee scores (93 vs 92 points; P = .531) and function scores (80 vs 80 points; P = 1.000), WOMAC scores (14 vs 15 points; P = .972), and UCLA activity scores (6 vs 6 points; P = 1.000) were not different between the 2 groups at 12 years follow-up. There were no differences in any radiographic and CT scan parameters between the 2 groups. Kaplan-Meier survivorship of the TKA component was 98% (95% confidence interval, 93-100) in the high-flexion fixed-bearing TKA group and 99% (95% confidence interval, 94-100) in the high-flexion mobile-bearing TKA group 12 years after the operation. We found no benefit to mobile-bearing TKA in terms of pain, function, radiographic and CT scan results, and survivorship. Longer-term follow-up is necessary to prove the benefit of the high-flexion mobile-bearing TKA over the high-flexion fixed-bearing TKA. Copyright © 2017 Elsevier Inc. All rights reserved.

Action of the antitumor and antispermatogenic agent lonidamine on electron transport in Ehrlich ascites tumor mitochondria.

Science.gov (United States)

Floridi, A; Lehninger, A L

1983-10-01

The effect of lonidamine, an antispermatogenic and antitumor drug, on the oxygen consumption, ATPase activity, and redox state of the electron carriers of Ehrlich ascites tumor mitochondria has been studied. Lonidamine inhibits ADP- and uncoupler-stimulated respiration on various NAD- and FAD-linked substrates, but does not affect state 4 respiration. Experiments to determine its site of action showed that lonidamine does not significantly inhibit electron flow through cytochrome oxidase. Electron flow through site 2, the ubiquinone-cytochrome b-cytochrome c1 complex, also was unaffected by lonidamine, which failed to inhibit the oxidation of duroquinol. Moreover, inhibition of electron flow through site 2 was also excluded because of the inability of the N,N,N',N'-tetramethyl-p-phenylenediamine bypass to relieve the lonidamine inhibition of the oxidation of pyruvate + malate. The F0F1ATPase activity and vectorial H+ ejection are also unaffected by lonidamine. The inhibition of succinate oxidation by lonidamine was found to take place at a point between succinate and iron-sulfur center S3. Spectroscopic experiments demonstrated that lonidamine inhibits the reduction of mitochondrial NAD+ by pyruvate + malate and other NAD-linked substrates in the transition from state 1 to state 4. However, lonidamine does not inhibit reduction of added NAD+ by submitochondrial vesicles or by soluble purified NAD-linked dehydrogenases. These observations, together with other evidence, suggest that electron transport in tumor mitochondria is inhibited by lonidamine at the dehydrogenase-coenzyme level, particularly when the electron carriers are in a relatively oxidized state and/or when the inner membrane-matrix compartment is in the condensed state. The action of lonidamine in several respects resembles the selective inhibition of electron transport in tumor cells produced by cytotoxic macrophages (D. L. Granger and A. L. Lehninger (1982) J. Cell Biol. 95, 527).

Measurement of lower limb alignment: there are within-person differences between weight-bearing and non-weight-bearing measurement modalities.

Science.gov (United States)

Schoenmakers, Daphne A L; Feczko, Peter Z; Boonen, Bert; Schotanus, Martijn G M; Kort, Nanne P; Emans, Pieter J

2017-11-01

Previous studies have compared weight-bearing mechanical leg axis (MLA) measurements to non-weight-bearing measurement modalities. Most of these studies compared mean or median values and did not analyse within-person differences between measurements. This study evaluates the within-person agreement of MLA measurements between weight-bearing full-length radiographs (FLR) and non-weight-bearing measurement modalities (computer-assisted surgery (CAS) navigation or MRI). Two independent observers measured the MLA on pre- and postoperative weight-bearing FLR in 168 patients. These measurements were compared to non-weight-bearing measurements obtained by CAS navigation or MRI. Absolute differences in individual subjects were calculated to determine the agreement between measurement modalities. Linear regression was used to evaluate the possibility that other independent variables impact the differences in measurements. A difference was found in preoperative measurements between FLR and CAS navigation (mean of 2.5° with limit of agreement (1.96 SD) of 6.4°), as well as between FLR and MRI measurements (mean of 2.4° with limit of agreement (1.96 SD) of 6.9°). Postoperatively, the mean difference between MLA measured on FLR compared to CAS navigation was 1.5° (limit of agreement (1.96 SD) of 4.6°). Linear regression analysis showed that weight-bearing MLA measurements vary significantly from non-weight-bearing MLA measurements. Differences were more severe in patients with mediolateral instability (p = 0.010), age (p = 0.049) and ≥3° varus or valgus alignment (p = 0.008). The clinical importance of this study lies in the finding that there are within-person differences between weight-bearing and non-weight-bearing measurement modalities. This has implications for preoperative planning, performing total knee arthroplasty (TKA), and clinical follow-up after TKA surgery using CAS navigation or patient-specific instrumentation. III.

Cool Polar Bears: Dabbing on the Texture

Science.gov (United States)

O'Connell, Jean

2011-01-01

In this article, the author describes how her second-graders created their cool polar bears. The students used the elements of shape and texture to create the bears. They used Monet's technique of dabbing paint so as to give the bear some texture on his fur.

Superior long-term survival for fixed bearing compared with mobile bearing in ligament-balanced total knee arthroplasty.

Science.gov (United States)

Heesterbeek, P J C; van Houten, A H; Klenk, J S; Eijer, H; Christen, B; Wymenga, A B; Schuster, A J

2018-05-01

Only few long-term data on ligament-balanced cruciate-retaining total knee arthroplasty (CR TKA) are currently available. Either a mobile- or fixed-bearing insert can be chosen, which showed good mid-term outcome and few complications and revisions. This multi-centre retrospective cross-sectional cohort study investigated the 12-year results of primary TKA using a balancing gap technique and compared survival and clinical outcome between fixed and mobile inserts. In this retrospective cross-sectional cohort study, 557 cases of three clinics (2 Swiss, 1 Dutch) operated between 1998 and 2003 with the first series of a TKA implanted with a balanced gap technique (433 (77.7%) fixed, 124 (22.3%) mobile (anterior-posterior gliding (7-9 mm) and rotational (15°) degrees of freedom) inserts) were included for survival analysis (Kaplan-Meier, by insert type). At the 12-year follow-up (FU) examination of 189 cases, range of motion, knee society score (KSS), numeric rating scale (NRS) for pain and satisfaction were determined and radiographs were evaluated by median tests, by insert type. Of 521 cases available for analysis, 28 (5.4%; 11 fixed, 17 mobile bearing) were revised. Mean cumulative survival after 12.4 years was 97.0% (95% CI 94.7-98.4) for fixed bearings and 85.4% (95% CI 77.5-90.7) after 12.2 years for mobile bearings, p bearings. This study showed a superior survival for fixed bearing compared with mobile bearing in a CR TKA using a ligament-balanced technique after more than 12 years. Clinical outcomes are excellent to good after long-term follow-up, and similar for fixed and mobile bearing. Therapeutic studies-retrospective cohort study, Level III.

On the Design of Tilting-Pad Thrust Bearings

DEFF Research Database (Denmark)

Heinrichson, Niels

2007-01-01

Pockets are often machined in the surfaces of tilting-pad thrust bearings to allow for hydrostatic jacking in the start-up phase. Pockets and other recesses in the surfaces of bearing pads influence the pressure distribution and thereby the position of the pivot resulting in the most advantageous...... based on the Reynolds equation are used. They include the effects of variations of viscosity with temperature and the deformation of the bearing pads due to pressure and thermal gradients. The models are validated using measurements. Tilting-pad bearings of standard design are studied and the influences...... of the friction loss. Both this bearing and the bearing design with enclosed recesses in the high-pressure regions of the pads suffer from a higher sensitivity to the position of the pivot. The design of such bearing is therefore no trivial task....

Bearing Health Assessment Based on Chaotic Characteristics

Directory of Open Access Journals (Sweden)

Chen Lu

2013-01-01

Full Text Available Vibration signals extracted from rotating parts of machinery carry a lot of useful information about the condition of operating machine. Due to the strong non-linear, complex and non-stationary characteristics of vibration signals from working bearings, an accurate and reliable health assessment method for bearing is necessary. This paper proposes to utilize the selected chaotic characteristics of vibration signal for health assessment of a bearing by using self-organizing map (SOM. Both Grassberger-Procaccia algorithm and Takens' theory are employed to calculate the characteristic vector which includes three chaotic characteristics, such as correlation dimension, largest Lyapunov exponent and Kolmogorov entropy. After that, SOM is used to map the three corresponding characteristics into a confidence value (CV which represents the health state of the bearing. Finally, a case study based on vibration datasets of a group of testing bearings was conducted to demonstrate that the proposed method can reliably assess the health state of bearing.

Mechanical design problems associated with turbopump fluid film bearings

Science.gov (United States)

Evces, Charles R.

1990-01-01

Most high speed cryogenic turbopumps for liquid propulsion rocket engines currently use ball or roller contact bearings for rotor support. The operating speeds, loads, clearances, and environments of these pumps combine to make bearing wear a limiting factor on turbopump life. An example is the high pressure oxygen turbopump (HPOTP) used in the Space Shuttle Main Engine (SSME). Although the HPOTP design life is 27,000 seconds at 30,000 rpms, or approximately 50 missions, bearings must currently be replaced after 2 missions. One solution to the bearing wear problem in the HPOTP, as well as in future turbopump designs, is the utilization of fluid film bearings in lieu of continuous contact bearings. Hydrostatic, hydrodynamic, and damping seal bearings are all replacement candidates for contact bearings in rocket engine high speed turbomachinery. These three types of fluid film bearings have different operating characteristics, but they share a common set of mechanical design opportunities and difficulties. Results of research to define some of the mechanical design issues are given. Problems considered include transient strat/stop rub, non-operational rotor support, bearing wear inspection and measurement, and bearing fluid supply route. Emphasis is given to the HPOTP preburner pump (PBP) bearing, but the results are pertinent to high-speed cryogenic turbomachinery in general.

Studies on combination effects of peplomycin and x-ray irradiation

International Nuclear Information System (INIS)

Munenaga, Yasuichi

1984-01-01

In order to study effects and methods of combination of peplomycin (PEP) and x-ray irradiation, inhibitory effects on DNA synthesis were investigated with synchronized cells from the parotid gland of mice treated with isoproterenol (IPR) and inhibitory effects on cell proliferation were investigated with Ehrlich solid tumor cells. PEP had dose-dependent effects on the inhibition of DNA synthesis and on the prolongation of cell cycles in the IPR-treated mouse cells. When 3.0 and 5.0 mg/kg of PEP were combined with 200 rad of x-ray irradiation at the early phase of G 1 , synergistic effects on the inhibition of DNA synthesis were seen. This was most noted in the group with PEP 30 minutes before irradiation. PEP had also dose-dependent inhibitory effects on the proliferation of Ehrlich solid tumor cells. This was increased when x-ray irradiation was combined with PEP. Inhibitory effects on the proliferation of tumor cells were greater when PEP was given before x-ray irradiation than after x-ray irradiation, regardless of the amount. The greatest effect was seen in the group with PEP 30 minutes before irradiation, as well as in the experiment with IPR-treated mouse cells. (Namekawa, K.)

Partial tooth gear bearings

Science.gov (United States)

Vranish, John M. (Inventor)

2010-01-01

A partial gear bearing including an upper half, comprising peak partial teeth, and a lower, or bottom, half, comprising valley partial teeth. The upper half also has an integrated roller section between each of the peak partial teeth with a radius equal to the gear pitch radius of the radially outwardly extending peak partial teeth. Conversely, the lower half has an integrated roller section between each of the valley half teeth with a radius also equal to the gear pitch radius of the peak partial teeth. The valley partial teeth extend radially inwardly from its roller section. The peak and valley partial teeth are exactly out of phase with each other, as are the roller sections of the upper and lower halves. Essentially, the end roller bearing of the typical gear bearing has been integrated into the normal gear tooth pattern.

What Can We Learn?--The Algonquin Bear Attack.

Science.gov (United States)

Strickland, Dan

1992-01-01

Describes a bear attack in Algonquin Park in Lake Opeongo (Canada) in which a man and woman were killed. Hypothesizes that the bear deliberately preyed on its victims and concludes that the bear was physically normal. Despite this isolated attack, the chance of being attacked by a black bear when camping is virtually nonexistent. (KS)

7 CFR 761.53 - Interest bearing accounts.

Science.gov (United States)

2010-01-01

... 7 Agriculture 7 2010-01-01 2010-01-01 false Interest bearing accounts. 761.53 Section 761.53... AGRICULTURE SPECIAL PROGRAMS GENERAL PROGRAM ADMINISTRATION Supervised Bank Accounts § 761.53 Interest bearing accounts. (a) A supervised bank account, if possible, will be established as an interest bearing deposit...

Active magnetic bearings: As applied to centrifugal pumps

Science.gov (United States)

Nelik, Lev; Cooper, Paul; Jones, Graham; Galecki, Dennis; Pinckney, Frank; Kirk, Gordon

1992-05-01

Application of magnetic bearings to boiler feed pumps presents various attractive features, such as longer bearing life, lower maintenance costs, and improved operability through control of the rotordynamics. Magnetic bearings were fitted to an eight-stage, 600 hp boiler feed pump, which generates 2600 ft of heat at 680 gpm and 3560 rpm. In addition to the varied and severe operating environment in steady state operation of this pump in a power plant, it is also subjected to transient loads during frequent starts and stops. These loads can now be measured by the in-built instrumentation of the magnetic bearings. Following site installation, a follow-up bearing tune-up was performed, and pump transient response testing was conducted. The bearing response was completely satisfactory, ensuring trouble-free pump operation even in the range of reduced load. The experience gained so far through design and testing proves feasibility of magnetic bearings for boiler feed pumps, which sets the stage for application of even higher energy centrifugal pumps equipped with magnetic bearings.

Lixiviation of plutonium contaminated solid wastes by aqueous solution of electro-generated reducing agents

International Nuclear Information System (INIS)

Agarande, Michelle

1991-01-01

This study concerns the development of the new concept for the decontamination of plutonium bearing solid wastes, based on the lixiviation of the wastes using electro-generated reducing agents. First, a comparative study of the kinetics of the dissolution of pure PuO 2 (prepared by calcination of Pu (IV) oxalate at 450 C) in sulfuric acid media, with different reducing agents, was realized. Qualitatively these reagents can be sorted in three groups: 1 / fast kinetics for Cr(II), V(II) and U(III); 2 / slow kinetics for Ti(III); 3 / very slow kinetics for V(III) and U(VI). In order to contribute to the design of an electrochemical reactor for the generation of the reducing agents usable for the lixiviation of plutonium bearing solid wastes, the study of the diffusion coefficients of both oxidized and reduced forms of different redox couples, at different temperatures, was undertaken. The results of this study also permits, from the knowledge of the diffusional activation energy of the ions, to conclude that the dissolution of pure plutonium dioxide under the action of these reducing agents is not diffusion limited. The feasibility of the plutonium decontamination treatment of synthetic or real solid wastes was then studied at laboratory scale using electro-generated V(II), which is with Cr(II) among the best reagents. The efficiency of the treatment was good, (80 pc Pu solubilisation yield), especially in the case of cellulosic or miscellaneous organic wastes. (author) [fr

[Induction of glutathione and activation of immune functions by low-dose, whole-body irradiation with gamma-rays].

Science.gov (United States)

Kojima, Shuji

2006-10-01

We first examined the relation between the induction of glutathione and immune functions in mice after low-dose gamma-ray irradiation. Thereafter, inhibition of tumor growth by radiation was confirmed in Ehrlich solid tumor (EST)-bearing mice. The total glutathione level of the splenocytes transiently increased soon after irradiation and reached a maximum at around 4 h postirradiation. Thereafter, the level reverted to the 0 h value by 24 h postirradiation. A significantly high splenocyte proliferative response was also recognized 4 h postirradiation. Natural killer (NK) activity was also increased significantly in a similar manner. The time at which the response reached the maximum coincided well with that of maximum total glutathione levels of the splenocytes in the gamma-ray-irradiated mice. Reduced glutathione exogenously added to splenocytes obtained from normal mice enhanced the proliferative response and NK activity in a dose-dependent manner. The inhibitory effects of radiation on tumor growth was then examined in EST-bearing mice. Repeated low-dose irradiation (0.5 Gy, four times, before and within an early time after inoculation) significantly delayed the tumor growth. Finally, the effect of single low-dose (0.5 Gy), whole-body gamma-ray irradiation on immune balance was examined to elucidate the mechanism underlying the antitumor immunity. The percentage of B cells in blood lymphocytes was selectively decreased after radiation, concomitant with an increase in that of the helper T cell population. The IFN-gamma level in splenocyte culture prepared from EST-bearing mice was significantly increased 48 h after radiation, although the level of IL-4 was unchanged. IL-12 secretion from macrophages was also enhanced by radiation. These results suggest that low-dose gamma-rays induce Th1 polarization and enhance the activities of tumoricidal effector cells, leading to an inhibition of tumor growth.

49 CFR 230.102 - Tender plain bearing journal boxes.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Tender plain bearing journal boxes. 230.102... Locomotives and Tenders Running Gear § 230.102 Tender plain bearing journal boxes. Plain bearing journal boxes... expected to damage the bearing; or have a detrimental effect on the lubrication of the journal and bearing...

Trichinella and polar bears: a limited risk for humans.

Science.gov (United States)

Dupouy-Camet, J; Bourée, P; Yera, H

2017-07-01

In this review, we identified 63 cases reported since World War II of human trichinellosis linked to the consumption of parasitized polar bear (Ursus maritimus) meat. This low number contrasts to the numerous cases of human trichinellosis related to consumption of the meat of black (U. americanus) or brown bears (U. arctos). The prevalence of Trichinella infection is high in bears, but larval muscular burden is usually lower in polar bears compared to other bear species. Polar bears, therefore, seem to play a limited role in the transmission of trichinellosis to humans, as native residents living in the Arctic traditionally consume well-cooked bear meat, and travellers and foreign hunters have only limited access to this protected species due to the declining polar bear population.

Public Perceptions of Bears and Management Interventions in Japan

OpenAIRE

Sakurai, Ryo; Jacobson, Susan K.

2011-01-01

Conservation of bears is a challenge globally. In Japan, Asiatic black bears (Ursus thibetanus) and brown bears (Ursus arctos) are considered a nuisance because of agricultural and property damage and personal human danger due to occasional human casualties. Reduction of human–bear conflicts in Japan would improve long-term conservation of bears and reduce risks to human health and safety. To understand Japanese perceptions of and experience with bears, we analyzed results of 5 public surveys...

Geometric modeling in the problem of ball bearing accuracy

Science.gov (United States)

Glukhov, V. I.; Pushkarev, V. V.; Khomchenko, V. G.

2017-06-01

The manufacturing quality of ball bearings is an urgent problem for machine-building industry. The aim of the research is to improve the geometric specifications accuracy of bearings based on evidence-based systematic approach and the method of adequate size, location and form deviations modeling of the rings and assembled ball bearings. The present work addressed the problem of bearing geometric specifications identification and the study of these specifications. The deviation from symmetric planar of rings and bearings assembly and mounting width are among these specifications. A systematic approach to geometric specifications values and ball bearings tolerances normalization in coordinate systems will improve the quality of bearings by optimizing and minimizing the number of specifications. The introduction of systematic approach to the international standards on rolling bearings is a guarantee of a significant increase in accuracy of bearings and the quality of products where they are applied.

Foothills model forest grizzly bear study : project update

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-01-01

This report updates a five year study launched in 1999 to ensure the continued healthy existence of grizzly bears in west-central Alberta by integrating their needs into land management decisions. The objective was to gather better information and to develop computer-based maps and models regarding grizzly bear migration, habitat use and response to human activities. The study area covers 9,700 square km in west-central Alberta where 66 to 147 grizzly bears exist. During the first 3 field seasons, researchers captured and radio collared 60 bears. Researchers at the University of Calgary used remote sensing tools and satellite images to develop grizzly bear habitat maps. Collaborators at the University of Washington used trained dogs to find bear scat which was analyzed for DNA, stress levels and reproductive hormones. Resource Selection Function models are being developed by researchers at the University of Alberta to identify bear locations and to see how habitat is influenced by vegetation cover and oil, gas, forestry and mining activities. The health of the bears is being studied by researchers at the University of Saskatchewan and the Canadian Cooperative Wildlife Health Centre. The study has already advanced the scientific knowledge of grizzly bear behaviour. Preliminary results indicate that grizzlies continue to find mates, reproduce and gain weight and establish dens. These are all good indicators of a healthy population. Most bear deaths have been related to poaching. The study will continue for another two years. 1 fig.

Superconductor bearings, flywheels and transportation

International Nuclear Information System (INIS)

Werfel, F N; Floegel-Delor, U; Rothfeld, R; Riedel, T; Goebel, B; Wippich, D; Schirrmeister, P

2012-01-01

This paper describes the present status of high temperature superconductors (HTS) and of bulk superconducting magnet devices, their use in bearings, in flywheel energy storage systems (FESS) and linear transport magnetic levitation (Maglev) systems. We report and review the concepts of multi-seeded REBCO bulk superconductor fabrication. The multi-grain bulks increase the averaged trapped magnetic flux density up to 40% compared to single-grain assembly in large-scale applications. HTS magnetic bearings with permanent magnet (PM) excitation were studied and scaled up to maximum forces of 10 kN axially and 4.5 kN radially. We examine the technology of the high-gradient magnetic bearing concept and verify it experimentally. A large HTS bearing is tested for stabilizing a 600 kg rotor of a 5 kWh/250 kW flywheel system. The flywheel rotor tests show the requirement for additional damping. Our compact flywheel system is compared with similar HTS–FESS projects. A small-scale compact YBCO bearing with in situ Stirling cryocooler is constructed and investigated for mobile applications. Next we show a successfully developed modular linear Maglev system for magnetic train operation. Each module levitates 0.25t at 10 mm distance during one-day operation without refilling LN 2 . More than 30 vacuum cryostats containing multi-seeded YBCO blocks are fabricated and are tested now in Germany, China and Brazil.

Superconducting Meissner effect bearings for cryogenic turbomachines, phase 2

Science.gov (United States)

Valenzuela, Javier A.; Martin, Jerry L.

1994-02-01

This is the final report of a Phase 2 SBIR project to develop Meissner effect bearings for miniature cryogenic turbomachines. The bearing system was designed for use in miniature cryogenic turboexpanders in reverse-Brayton-cycle cryocoolers. The cryocoolers are designed to cool sensors on satellites. Existing gas bearings for this application run in a relatively warm state. The heat loss from the bearings into the shaft and into the cold process gas imposes a penalty on the cycle efficiency. By using cold Meissner effect bearings, this heat loss could be minimized, and the input power per unit of cooling for these cryocoolers could be reduced. Two bearing concepts were explored in this project. The first used an all-magnetic passive radial suspension to position the shaft over a range of temperatures from room temperature to 77 K. This bearing concept was proven to be feasible, but impractical for the miniature high-speed turbine application since it lacked the required shaft positioning accuracy. A second bearing concept was then developed. In this concept, the Meissner effect bearings are combined with self-acting gas bearings. The Meissner effect bearing provides the additional stiffness and damping required to stabilize the shaft at low temperature, while the gas bearing provides the necessary accuracy to allow very small turbine tip clearances (5mm) and high speeds (greater than 500,000 rpm).

29 CFR 780.124 - Raising of fur-bearing animals.

Science.gov (United States)

2010-07-01

... 29 Labor 3 2010-07-01 2010-07-01 false Raising of fur-bearing animals. 780.124 Section 780.124... General Scope of Agriculture Raising of Livestock, Bees, Fur-Bearing Animals, Or Poultry § 780.124 Raising of fur-bearing animals. (a) The term “fur-bearing animals” has reference to animals which bear fur of...

Polar bears and sea ice habitat change

Science.gov (United States)

Durner, George M.; Atwood, Todd C.; Butterworth, Andy

2017-01-01

The polar bear (Ursus maritimus) is an obligate apex predator of Arctic sea ice and as such can be affected by climate warming-induced changes in the extent and composition of pack ice and its impacts on their seal prey. Sea ice declines have negatively impacted some polar bear subpopulations through reduced energy input because of loss of hunting habitats, higher energy costs due to greater ice drift, ice fracturing and open water, and ultimately greater challenges to recruit young. Projections made from the output of global climate models suggest that polar bears in peripheral Arctic and sub-Arctic seas will be reduced in numbers or become extirpated by the end of the twenty-first century if the rate of climate warming continues on its present trajectory. The same projections also suggest that polar bears may persist in the high-latitude Arctic where heavy multiyear sea ice that has been typical in that region is being replaced by thinner annual ice. Underlying physical and biological oceanography provides clues as to why polar bear in some regions are negatively impacted, while bears in other regions have shown no apparent changes. However, continued declines in sea ice will eventually challenge the survival of polar bears and efforts to conserve them in all regions of the Arctic.

Hybrid bearings for LH2 and LO2 turbopumps

Science.gov (United States)

Butner, M. F.; Lee, F. C.

1985-01-01

Hybrid combinations of hydrostatic and ball bearings can improve bearing performance for liquid hydrogen and liquid oxygen turbopumps. Analytic studies were conducted to optimize hybrid bearing designs for the SSME-type turbopump conditions. A method to empirically determine damping coefficients was devised. Four hybrid bearing configurations were designed, and three were fabricated. Six hybrid and hydrostatic-only bearing configurations will be tested for steady-state and transient performance, and quantification of damping coefficients. The initial tests were conducted with the liquid hydrogen bearing.

Evaluation of ball and roller bearings restored by grinding

Science.gov (United States)

Parker, R. J.; Zaretsky, E. V.; Chen, S. M.

1976-01-01

A joint program was undertaken to restore by grinding those rolling-element bearings which are currently being discarded at aircraft engine and transmission overhaul. Three bearing types were selected from the UH-1 helicopter engine (T-53) and transmission for the pilot program. Groups of each of these bearings were visually and dimensionally inspected for suitability for restoration. A total of 250 bearings were restored by grinding. Of this number, 30 bearings from each type were endurance tested to a TBO of 1600 hours. No bearing failures occurred related to the restoration by grinding process. The two bearing failures which occurred were due to defective rolling elements and were typical of those which may occur in new bearings. The restorable component yield to the three groups was in excess of 90 percent.

The dynamic state monitoring of bearings system

Directory of Open Access Journals (Sweden)

Marek Krynke

2015-03-01

Full Text Available The article discusses the methods of dynamic state monitoring of bearings system. A vibration signal contains important technical information about the machine condition and is currently the most frequently used in diagnostic bearings systems. One of the main ad-vantages of machine condition monitoring is identifying the cause of failure of the bearings and taking preventative measures, otherwise the operation of such a machine will lead to frequent replacement of the bearings. Monitoring changes in the course of the operation of machin-ery repair strategies allows keeping the conditioned state of dynamic failure conditioned preventive repairs and repairs after-failure time. In addition, the paper also presents the fundamental causes of bearing failure and identifies mechanisms related to the creation of any type of damage.

Integrated smart bearings for next generation aero-engines Part 1: Development of a sensor suite for automatic bearing health monitoring

OpenAIRE

Bashir, Imran; Wang, Ling; Harvey, Terence; Zaghari, Bahareh; Weddell, Alexander; White, Neil

2017-01-01

The development of smart bearing solutions will contribute to increased aircraft engine reliability, allowing the early detection of bearing failure through robust health monitoring. This project aims to develop intelligent bearing systems for an Ultra High Propulsion Efficiency (UHPE) ground test demonstrator, where a fully integrated self-powered wireless sensing system will be developed for future aircraft. This paper provides a comprehensive review of the state-of-the-art smart bearing te...

Distributed bearing fault diagnosis based on vibration analysis

Science.gov (United States)

Dolenc, Boštjan; Boškoski, Pavle; Juričić, Đani

2016-01-01

Distributed bearing faults appear under various circumstances, for example due to electroerosion or the progression of localized faults. Bearings with distributed faults tend to generate more complex vibration patterns than those with localized faults. Despite the frequent occurrence of such faults, their diagnosis has attracted limited attention. This paper examines a method for the diagnosis of distributed bearing faults employing vibration analysis. The vibrational patterns generated are modeled by incorporating the geometrical imperfections of the bearing components. Comparing envelope spectra of vibration signals shows that one can distinguish between localized and distributed faults. Furthermore, a diagnostic procedure for the detection of distributed faults is proposed. This is evaluated on several bearings with naturally born distributed faults, which are compared with fault-free bearings and bearings with localized faults. It is shown experimentally that features extracted from vibrations in fault-free, localized and distributed fault conditions form clearly separable clusters, thus enabling diagnosis.

49 CFR 215.115 - Defective roller bearing.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Defective roller bearing. 215.115 Section 215.115... § 215.115 Defective roller bearing. (a) A railroad may not place or continue in service a car, if the car has— (1) A roller bearing that shows signs of having been overheated as evidenced by— (i...

Trends in Controllable Oil Film Bearings

DEFF Research Database (Denmark)

Santos, Ilmar

2011-01-01

This work gives an overview about the theoretical and experimental achievements of mechatronics applied to oil film bearings, with the aim of: controlling the lateral vibration of flexible rotating shafts; modifying bearing dynamic characteristics, as stiffness and damping properties; increasing......" components and be applied to rotating machines with the goal of avoiding unexpected stops of plants, performing rotordynamic tests and identifying model parameters "on site". Emphasis is given to the controllable lubrication (active lubrication) applied to different types of oil film bearings, i...

Polar bears: the fate of an icon.

Science.gov (United States)

Fitzgerald, Kevin T

2013-11-01

Polar bears are one of the most iconic animals on our planet. Worldwide, even people who would never see one are drawn to these charismatic arctic ice hunters. They are the world's largest terrestrial carnivore, and despite being born on land, they spend most of their lives out on the sea ice and are considered a marine mammal. Current global studies estimate there are around 20,000 animals in some 19 discrete circumpolar populations. Aside from pregnant females denning in the winter months to give birth, the white bears do not hibernate. They spend their winters on the sea ice hunting seals, an activity they are spectacularly adapted for. Research on these animals is incredibly difficult because of the inhospitable surroundings they inhabit and how inaccessible they make the bears. For many years, the sum of our understanding of the natural history of polar bears came from tracks, scats, the remains of their kills, abandoned dens, and anecdotal observations of native hunters, explorers, and early biologists. Nonetheless, the last 40 years have seen a much better picture of their biology emerge thanks to, first, dedicated Canadian researchers and, later, truly international efforts of workers from many countries. Veterinarians have contributed to our knowledge of the bears by delivering and monitoring anesthesia, obtaining blood samples, performing necropsies, investigating their reproduction, conducting radiotelemetry studies, and examining their behavior. Recently, new technologies have been developed that revolutionize the study of the lives and natural history of undisturbed polar bears. These advances include better satellite radiotelemetry equipment and the development of remote-controlled miniature devices equipped with high-definition cameras. Such new modalities provide dramatic new insights into the life of polar bears. The remarkable degree of specialized adaptation to life on the sea ice that allowed the bears to be successful is the very reason that

Lubrication of Space Shuttle Main Engine Turbopump Bearings

Science.gov (United States)

Gibson, Howard; Munafo, Paul (Technical Monitor)

2001-01-01

The Space Shuttle has three main engines that are used for propulsion into orbit. These engines are fed propellants by four turbopumps on each engine. A main element in the turbopump is the bearings supporting the rotor that spins the turbine blades and the pump impeller. These bearings are required to spin at very high speeds, support radial and thrust loads, and have high wear resistance without the benefit of lubrication. The liquid hydrogen and oxygen propellants flow through the bearings to cool the surfaces. The volatile nature of the propellants excludes any conventional means of lubrication. Lubrication for these bearings is provided by the ball separator inside the bearing. The separator is a composite material that supplies a transfer film of lubrication to the rings and balls. New separator materials and lubrication schemes have been investigated at Marshall Space Flight Center in a bearing test rig with promising results. Hybrid bearings with silicon nitride balls have also been evaluated. The use of hybrid, silicon nitride ball bearings in conjunction -with better separator materials has shown excellent results. The work that Marshall has done is being utilized in turbopumps flying on the space shuttle fleet and will be utilized in future space travel. This result of this work is valuable for all aerospace and commercial applications where high-speed bearings are used.

Centrifuge advances using HTS magnetic bearings

Science.gov (United States)

Werfel, F. N.; Flögel-Delor, U.; Rothfeld, R.; Wippich, D.; Riedel, T.

2001-05-01

Passive magnetic bearings are of increasing technical interest. We performed experiments with centrifugal rotors to analyze gyroscopic forces in terms imbalance, rotor elasticity and damping. Centrifuge rotors need to be operated soft and stable without whirling the sediments. In order to evaluate optimal parameters critical and resonance behaviors are investigated. Eccentricities up 2 mm are safely passed by accelerating test wheels. In a simple model we describe the effect of passing critical rotational speeds. Measurements of bearing properties and wheel performance are presented. We have constructed a first prototype centrifuge designed with a HTS double bearing which operates a titanium rotor safely up to 30 000 rpm. A 15 W Stirling cooler serves cryogenics of the YBCO stators. From the experiments design guidelines for centrifugal applications with HTS bearings are given.

Bear bile: dilemma of traditional medicinal use and animal protection

Directory of Open Access Journals (Sweden)

Nagamatsu Tadashi

2009-01-01

Full Text Available Abstract Bear bile has been used in Traditional Chinese Medicine (TCM for thousands of years. Modern investigations showed that it has a wide range of pharmacological actions with little toxicological side effect and the pure compounds have been used for curing hepatic and biliary disorders for decades. However, extensive consumption of bear bile made bears endangered species. In the 1980's, bear farming was established in China to extract bear bile from living bears with "Free-dripping Fistula Technique". Bear farming is extremely inhumane and many bears died of illness such as chronic infections and liver cancer. Efforts are now given by non-governmental organizations, mass media and Chinese government to end bear farming ultimately. At the same time, systematic research has to be done to find an alternative for bear bile. In this review, we focused on the literature, laboratory and clinical results related to bear bile and its substitutes or alternative in English and Chinese databases. We examined the substitutes or alternative of bear bile from three aspects: pure compounds derived from bear bile, biles from other animals and herbs from TCM. We then discussed the strategy for stopping the trading of bear bile and issues of bear bile related to potential alternative candidates, existing problems in alternative research and work to be done in the future.

Bear bile: dilemma of traditional medicinal use and animal protection

Science.gov (United States)

Feng, Yibin; Siu, Kayu; Wang, Ning; Ng, Kwan-Ming; Tsao, Sai-Wah; Nagamatsu, Tadashi; Tong, Yao

2009-01-01

Bear bile has been used in Traditional Chinese Medicine (TCM) for thousands of years. Modern investigations showed that it has a wide range of pharmacological actions with little toxicological side effect and the pure compounds have been used for curing hepatic and biliary disorders for decades. However, extensive consumption of bear bile made bears endangered species. In the 1980's, bear farming was established in China to extract bear bile from living bears with "Free-dripping Fistula Technique". Bear farming is extremely inhumane and many bears died of illness such as chronic infections and liver cancer. Efforts are now given by non-governmental organizations, mass media and Chinese government to end bear farming ultimately. At the same time, systematic research has to be done to find an alternative for bear bile. In this review, we focused on the literature, laboratory and clinical results related to bear bile and its substitutes or alternative in English and Chinese databases. We examined the substitutes or alternative of bear bile from three aspects: pure compounds derived from bear bile, biles from other animals and herbs from TCM. We then discussed the strategy for stopping the trading of bear bile and issues of bear bile related to potential alternative candidates, existing problems in alternative research and work to be done in the future. PMID:19138420

Big bearings. Unsung hero; Kyodaina jikuuke. Hitome ni tsukanai hatarakimono

Energy Technology Data Exchange (ETDEWEB)

Nanba, S. [Koyo Seiko Co. Ltd., Osaka (Japan)

1997-03-05

This paper introduces examples of the use of big bearings. Bearings are divided largely into those used for radial load supporting and those used for thrust load supporting, while big bearings are often used for the latter usage. Thrust bearings include a cutter heat supporting bearing for tunnel excavator working underground, in addition to those used for swing motion of parabolic antennas and tower cranes. A bearing used in an excavator has an outer diameter of about half that of the excavator. The outer diameter of a shielding machine practically used in tunnel drilling currently has an outer diameter of 14,140 mm, and the outer diameter of the bearing is 7200 mm (bearing weighing 45 tons). Other big thrust bearings may include a swing tower swinging thrust bearing used in a continuous casting facility. Big radial bearings are used in iron and steel making facilities. This paper describes two examples of bearings used in this application. A spherical roller bearing to support converter trunion should be of an ultra big size to withstand total weight of about 1400 tons composed of a converter weight and weight of steel to be processed. A four-row cylindrical roller bearing to support the backup roll of a thick plate rolling mill is a bearing with durability against large loads to support reduction rolls whose size have become increasingly large. 2 refs., 5 figs.

Oak-Black Bear Relationships in Southeastern Uplands

Science.gov (United States)

Joseph D. Clark

2004-01-01

Bears (Ursus americanus) primarily occur in upland habitats in the Southeast because uplands were the last to be developed for agriculture and were more likely to become publicly owned. National parks and forests created in the early to mid-1900s served as sources to supply surrounding uplands with bears. Bears could not survive in southeastern...

49 CFR 215.111 - Defective plain bearing.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Defective plain bearing. 215.111 Section 215.111... § 215.111 Defective plain bearing. A railroad may not place or continue in service a car, if the car has a plain bearing— (a) That is missing, cracked, or broken; (b) On which the bearing liner— (1) Is...

Technical Development Path for Gas Foil Bearings

Science.gov (United States)

Dellacorte, Christopher

2016-01-01

Foil gas bearings are in widespread commercial use in air cycle machines, turbocompressors and microturbine generators and are emerging in more challenging applications such as turbochargers, auxiliary power units and propulsion gas turbines. Though not well known, foil bearing technology is well over fifty years old. Recent technological developments indicate that their full potential has yet to be realized. This paper investigates the key technological developments that have characterized foil bearing advances. It is expected that a better understanding of foil gas bearing development path will aid in future development and progress towards more advanced applications.

Enhanced antitumor efficacy of cisplatin in combination with HemoHIM in tumor-bearing mice.

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Park, Hae-Ran; Ju, Eun-Jin; Jo, Sung-Kee; Jung, Uhee; Kim, Sung-Ho; Yee, Sung-Tae

2009-03-17

Although cisplatin is one of the most effective chemotherapeutic agents, cisplatin alone does not achieve a satisfactory therapeutic outcome. Also cisplatin accumulation shows toxicity to normal tissues. In this study, we examined the possibility of HemoHIM both to enhance anticancer effect with cisplatin and to reduce the side effects of cisplatin in melanoma-bearing mice. HemoHIM was prepared by adding the ethanol-insoluble fraction to the total water extract of a mixture of 3 edible herbs, Angelica Radix, Cnidium Rhizoma and Paeonia Radix. Anticancer effects of HemoHIM with cisplatin were evaluated in melanoma-bearing mice. We used a Cr51-release assay to measure the activity of NK/Tc cell and ELISA to evaluate the production of cytokines. In melanoma-bearing mice, cisplatin (4 mg/kg B.W.) reduced the size and weight of the solid tumors, and HemoHIM supplementation with cisplatin enhanced the decrease of both the tumor size (p HemoHIM itself did not inhibit melanoma cell growth in vitro, and did not disturb the effects of cisplatin in vitro. However HemoHIM administration enhanced both NK cell and Tc cell activity in mice. Interestingly, HemoHIM increased the proportion of NK cells in the spleen. In melanoma-bearing mice treated with cisplatin, HemoHIM administration also increased the activity of NK cells and Tc cells and the IL-2 and IFN-gamma secretion from splenocytes, which seemed to contribute to the enhanced efficacy of cisplatin by HemoHIM. Also, HemoHIM reduced nephrotoxicity as seen by tubular cell of kidney destruction. HemoHIM may be a beneficial supplement during cisplatin chemotherapy for enhancing the anti-tumor efficacy and reducing the toxicity of cisplatin.

Flywheel Energy Storage System Suspended by Hybrid Magnetic Bearing

Science.gov (United States)

Owusu-Ansah, Prince; Hu, Yefa; Misbawu, Adam

This work presents a prototype flywheel energy storage system (FESS) suspended by hybrid magnetic bearing (HMB) rotating at a speed of 20000rpm with a maximum storage power capacity of 30W with a maximum tip speed of 300m/s. The design presented is an improvement of most existing FESS, as the design incorporates a unique feature in that the upper and the lower rotor and stator core are tapered which enhances larger thrust and much lower radial force to be exerted on the system. Without any adverse effect being experienced by the model. The work also focuses on the description of developing a prototype FESS suspended by HMB using solid works as a basis of developing in the nearer future a more improved FESS suspended by HMB capable of injecting the ever increasing high energy demand situation in the 21st century and beyond.

Grizzly bear diet shifting on reclaimed mines

Directory of Open Access Journals (Sweden)

Bogdan Cristescu

2015-07-01

Full Text Available Industrial developments and reclamation change habitat, possibly altering large carnivore food base. We monitored the diet of a low-density population of grizzly bears occupying a landscape with open-pit coal mines in Canada. During 2009–2010 we instrumented 10 bears with GPS radiocollars and compared their feeding on reclaimed coal mines and neighboring Rocky Mountains and their foothills. In addition, we compared our data with historical bear diet for the same population collected in 2001–2003, before extensive mine reclamation occurred. Diet on mines (n=331 scats was dominated by non-native forbs and graminoids, while diets in the Foothills and Mountains consisted primarily of ungulates and Hedysarum spp. roots respectively, showing diet shifting with availability. Field visitation of feeding sites (n=234 GPS relocation clusters also showed that ungulates were the main diet component in the Foothills, whereas on reclaimed mines bears were least carnivorous. These differences illustrate a shift to feeding on non-native forbs while comparisons with historical diet reveal emergence of elk as an important bear food. Food resources on reclaimed mines attract bears from wilderness areas and bears may be more adaptable to landscape change than previously thought. The grizzly bear’s ready use of mines cautions the universal view of this species as umbrella indicative of biodiversity.

Diet and Macronutrient Optimization in Wild Ursids: A Comparison of Grizzly Bears with Sympatric and Allopatric Black Bears.

Science.gov (United States)

Costello, Cecily M; Cain, Steven L; Pils, Shannon; Frattaroli, Leslie; Haroldson, Mark A; van Manen, Frank T

2016-01-01

When fed ad libitum, ursids can maximize mass gain by selecting mixed diets wherein protein provides 17 ± 4% of digestible energy, relative to carbohydrates or lipids. In the wild, this ability is likely constrained by seasonal food availability, limits of intake rate as body size increases, and competition. By visiting locations of 37 individuals during 274 bear-days, we documented foods consumed by grizzly (Ursus arctos) and black bears (Ursus americanus) in Grand Teton National Park during 2004-2006. Based on published nutritional data, we estimated foods and macronutrients as percentages of daily energy intake. Using principal components and cluster analyses, we identified 14 daily diet types. Only 4 diets, accounting for 21% of days, provided protein levels within the optimal range. Nine diets (75% of days) led to over-consumption of protein, and 1 diet (3% of days) led to under-consumption. Highest protein levels were associated with animal matter (i.e., insects, vertebrates), which accounted for 46-47% of daily energy for both species. As predicted: 1) daily diets dominated by high-energy vertebrates were positively associated with grizzly bears and mean percent protein intake was positively associated with body mass; 2) diets dominated by low-protein fruits were positively associated with smaller-bodied black bears; and 3) mean protein was highest during spring, when high-energy plant foods were scarce, however it was also higher than optimal during summer and fall. Contrary to our prediction: 4) allopatric black bears did not exhibit food selection for high-energy foods similar to grizzly bears. Although optimal gain of body mass was typically constrained, bears usually opted for the energetically superior trade-off of consuming high-energy, high-protein foods. Given protein digestion efficiency similar to obligate carnivores, this choice likely supported mass gain, consistent with studies showing monthly increases in percent body fat among bears in this

Stepping-Motion Motor-Control Subsystem For Testing Bearings

Science.gov (United States)

Powers, Charles E.

1992-01-01

Control subsystem closed-loop angular-position-control system causing motor and bearing under test to undergo any of variety of continuous or stepping motions. Also used to test bearing-and-motor assemblies, motors, angular-position sensors including rotating shafts, and like. Monitoring subsystem gathers data used to evaluate performance of bearing or other article under test. Monitoring subsystem described in article, "Monitoring Subsystem For Testing Bearings" (GSC-13432).

Noise reduction of rotating machinery by viscoelastic bearing supports

NARCIS (Netherlands)

Tillema, H.G.

2003-01-01

The demand for silent rolling bearing applications, such as electric motors and gearboxes, has resulted in an investigation of viscoelastic bearing supports. By placing a thin viscoelastic layer between the bearing outer ring and the surrounding structure, vibrations of the shaft-bearing arrangement

Polar bear attacks on humans: Implications of a changing climate

Science.gov (United States)

Wilder, James; Vongraven, Dag; Atwood, Todd C.; Hansen, Bob; Jessen, Amalie; Kochnev, Anatoly A.; York, Geoff; Vallender, Rachel; Hedman, Daryll; Gibbons, Melissa

2017-01-01

Understanding causes of polar bear (Ursus maritimus) attacks on humans is critical to ensuring both human safety and polar bear conservation. Although considerable attention has been focused on understanding black (U. americanus) and grizzly (U. arctos) bear conflicts with humans, there have been few attempts to systematically collect, analyze, and interpret available information on human-polar bear conflicts across their range. To help fill this knowledge gap, a database was developed (Polar Bear-Human Information Management System [PBHIMS]) to facilitate the range-wide collection and analysis of human-polar bear conflict data. We populated the PBHIMS with data collected throughout the polar bear range, analyzed polar bear attacks on people, and found that reported attacks have been extremely rare. From 1870–2014, we documented 73 attacks by wild polar bears, distributed among the 5 polar bear Range States (Canada, Greenland, Norway, Russia, and United States), which resulted in 20 human fatalities and 63 human injuries. We found that nutritionally stressed adult male polar bears were the most likely to pose threats to human safety. Attacks by adult females were rare, and most were attributed to defense of cubs. We judged that bears acted as a predator in most attacks, and that nearly all attacks involved ≤2 people. Increased concern for both human and bear safety is warranted in light of predictions of increased numbers of nutritionally stressed bears spending longer amounts of time on land near people because of the loss of their sea ice habitat. Improved conflict investigation is needed to collect accurate and relevant data and communicate accurate bear safety messages and mitigation strategies to the public. With better information, people can take proactive measures in polar bear habitat to ensure their safety and prevent conflicts with polar bears. This work represents an important first step towards improving our understanding of factors influencing

Nuclear fuel handling grapple carriage with self-lubricating bearing

International Nuclear Information System (INIS)