27 research outputs found

    Tribological Aspects of the Process of Winding the Steel Rope Around the Winch Drum

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    Proper winding of the steel rope around the winch drum is great importance, mostly for: prolonging the service life of the rope, reduction of deformations of the body and the sides of the drum if the winding of the rope is multilayered, increasing of the safety factors, easier unwinding of the rope while lowering the load, even running of the drive unit, etc. The focus of this paper is on the analysis of the friction which occurs in the process of winding and unwinding the rope around the winch drum. Friction force is in its highest intensity when the rope passes from one layer to another, if the winding of the rope is multilayered. As the result of the research, certain mechanisms of winding of the rope from the aspects of the friction force were obtained, and the effects of the forces on the sides of the drum were analyzed

    Strength Analysis of Eight-Wheel Bogie of Bucket Wheel Excavator

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    Crawler travel gear is a type of heavy vehicle propulsion that is commonly found in tanks, excavators, and specialized off-road vehicles. They have an advantage over wheels when it comes to robust vehicle weight distribution over soft terrain, and some disadvantages as well. They can damage paved roads and have complex design so, considering the enormous weight they must carry, their reliability must be determined and verified. The main parts of the assembly are the drive wheels, which move the crawler, and the supporting structure that holds four-wheel bogies and two-wheel bogies. In this paper, we present a methodology for FEM analysis of parts of an eight-wheel bogie according to DIN 22261-2 standard

    Insulin responses to acute glucose infusions in BuŔa and Holstein-Friesian cattle breed during the peripartum period: Comparative study

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    The aim of this study was to compare insulin responsevness to acute glucose infusion in cows of Holstein Friesian (HF) and BuŔa breeds during the peripartal period. Eight cows per each group (HF and BuŔa), were chosen. At day 7 prior to calving (ante partum) and day 14 after calving (post partum) animals were subjected to a glucose tolerance test (GTT). Blood samples were taken immediately before infusion and 15, 30, 60, 120 and 180 min thereafter. Glucose and insulin concentrations were measured in each blood sample, while BHBA and NEFA were measured only in samples taken before the infusion. QUICKY an indicator of insulin resistance in cows was calculated. Basal glycemia did not significantly differ between the breeds. Basal insulinemia was significantly higher in BuŔa than in HF cows in both examined periods (p<0.001, respectively). Basal NEFA levels tended (p=0.06) to be higher in BuŔa cows compared with those of HF ante partum, and was significantly higher (p<0.001) post partum. Basal BHBA was significantly lower in BuŔa than HF cows in both examined periods (p<0.01; p<0.001). QUICKI was significantly lower in BuŔa compared to HF cows both ante partum and post partum periods (p<0.001, respectively). Glycemia determined during GTT were higher in BuŔa than HF cows, both ante partum and post partum, but significantly starting from minute 15 ante partum i.e. minute 30 post partum. Insulinemia determined during GTT was significantly lower at min 15, and significantly higher starting from min 90 in BuŔa than HF cows, both ante partum and post partum. Results obtained in this study indicate on difference in insulin responsevness to acute glucose infusion between the examined breeds, which is probably a consequence of the difference in the degree of negative energy balance rather than of selection on high milk production. Namely, decreased insulin tissues sensitivity and decreased insulin responsiveness in BuŔa compared to HF cows is probably the consequence of inadequate energy intake from alimentary sources which leads to enhanced usage of energy from body reserves. [Projekat Ministarstva nauke Republike Srbije, br. 46002

    New insights into body condition score and its association with fatty liver in Holstein dairy cows

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    The aim of this study was to estimate the association between body condition and fatty liver in high-yielding dairy cows. One hundred dry Holstein cows were selected. Cows were scored once for body condition during the dry period, puerperium and month 2 of lactation, according to the system provided by Elanco Animal Health Buletin Al 8478. Body condition loss was determined as marked if loss was over 0.7 points between two consecutive phases of cycles and over 1.5 points between puerperium and month 2 of lactation. Liver tissue samples were taken 12 d after calving and tested for lipid content. 50% of cows had mild (3.92 +/- 3.33% fat), 33% moderate (19.28 +/- 5.18% fat), and 17% severe fatty liver (36.21 +/- 4.55% fat). The mean body condition scores were 3.79 +/- 0.55 (dry period), 3.18 +/- 0.34 (puerperium) and 2.90 +/- 0.29 (month 2 of lactation). Marked body condition loss from the dry period to puerperium had 38% of cows, 20% from dry period to month 2 of lactation and 8% from puerperium to month 2 of lactation. Body condition scores out of the physiological range had 39% dry cows, 49 % cows in puerperium and 9% cows at month 2 of lactation. After dividing cows into groups according to fatty liver degree, it was shown that only cows with severe fatty liver were obese during the dry period and that 76.47% of cows from this group had marked condition loss from the dry period to puerperium, 47.06% from dry period to month 2 of lactation and 23.53% from puerperium to month 2 of lactation. These indicate that in cows with severe fatty liver lipomobilisation is intensive and starts around calving, before milk production enhacement. Our results indicate a strong association between body condition and fatty liver in cows, which can be estimated only when body condition is analyzed in details. Besides, our results clearly indicate that body condition is not the only etiological factor that leads to fatty liver in dairy cows

    DISLOKACIJA SIRIÅ TA KOD GOVEDA

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    Promena položaja je najvažnija bolest siriÅ”ta goveda. U zapatima visoko-mlečnihkrava pojavlјivanje bolesti varira u Å”irokom rasponu od 1 do 18 posto, kod krava istočno-frizijske rase dislokacija siriÅ”ta je dijagnostikovana u 1 do 3 posto životinja, a uzapatima krava holÅ”tajn rase ustanovlјena je kod 5 do 18 posto životinja. Kod kravasimentalske rase promena pol

    Variability of blood serum biochemical parameters in Karakachan sheep

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    Karakachan sheep represents an endangered, indigenous sheep breed from Balkan Peninsula. There is relatively little information about the characteristics of this sheep breed in the veterinary scientific literature. The aim of this research was an examination of certain metabolic profile parameters of the Karakachan sheep blood serum, and variability of their concentrations in comparison to age and some other indigenous sheep breeds from Balkans. Examination was conducted on 14 clinically healthy sheep divided in two age groups. Blood samples were collected by puncture of v. jugularis and blood serum was separated after spontaneous coagulation. The concentrations of total protein, albumin, calcium, inorganic phosphorus, aspartate amino transferase (AST) and Ī³- glutamyl transferase (GGT) were determined. In relation to age of Karakachan sheep, statistically significant difference between the calculated mean values of examined parameters was not observed. A statistically significant difference was found between the mean concentrations of the studied parameters in Karakachan sheep and other breeds in total protein (Tsigai, Dubrovnik and Dalmatian sheep), albumin (Dalmatian), calcium and inorganic phosphorus (Tsigai, Dubrovnik) and AST's (Dalmatian, Karakachan sheep from Bulgaria)

    Heat shock factor-1 modulates p53 activity in the transcriptional response to DNA damage

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    Here we define an important role for heat shock factor 1 (HSF1) in the cellular response to genotoxic agents. We demonstrate for the first time that HSF1 can complex with nuclear p53 and that both proteins are co-operatively recruited to p53-responsive genes such as p21. Analysis of natural and synthetic cis elements demonstrates that HSF1 can enhance p53-mediated transcription, whilst depletion of HSF1 reduces the expression of p53-responsive transcripts. We find that HSF1 is required for optimal p21 expression and p53-mediated cell-cycle arrest in response to genotoxins while loss of HSF1 attenuates apoptosis in response to these agents. To explain these novel properties of HSF1 we show that HSF1 can complex with DNA damage kinases ATR and Chk1 to effect p53 phosphorylation in response to DNA damage. Our data reveal HSF1 as a key transcriptional regulator in response to genotoxic compounds widely used in the clinical setting, and suggest that HSF1 will contribute to the efficacy of these agents

    Elective Cancer Surgery in COVID-19-Free Surgical Pathways During the SARS-CoV-2 Pandemic: An International, Multicenter, Comparative Cohort Study.

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    PURPOSE: As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS: This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS: Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION: Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

    Elective cancer surgery in COVID-19-free surgical pathways during the SARS-CoV-2 pandemic: An international, multicenter, comparative cohort study

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    PURPOSE As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19ā€“free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19ā€“free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19ā€“free surgical pathways. Patients who underwent surgery within COVID-19ā€“free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19ā€“free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity scoreā€“matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19ā€“free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION Within available resources, dedicated COVID-19ā€“free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

    The disruption of proteostasis in neurodegenerative diseases

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    Cells count on surveillance systems to monitor and protect the cellular proteome which, besides being highly heterogeneous, is constantly being challenged by intrinsic and environmental factors. In this context, the proteostasis network (PN) is essential to achieve a stable and functional proteome. Disruption of the PN is associated with aging and can lead to and/or potentiate the occurrence of many neurodegenerative diseases (ND). This not only emphasizes the importance of the PN in health span and aging but also how its modulation can be a potential target for intervention and treatment of human diseases.info:eu-repo/semantics/publishedVersio
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