70 research outputs found
Numerical model of the diode laser overlapped remelting of structural steel
This paper presents a simulation of laser surface remelting with the SYSWELD finite element method software. Micro-structural changes, increase of hardness, and surface profile modification of the remelted samples are evaluated.The model input file was edited to involve laser track overlapping with a time delay. Temperature field distribution and metallographic phase proportions were extracted from output data in graphical form to demonstrate the influence of repeated melting on phase development in the overlapped region. The stored model is ready to be modified for other materials or process parameters
Metrics of perineal support (MOPS) study
Background: Manual perineal protection (MPP) is an intrapartum intervention suggested to protect perineal integrity during childbirth. Proper execution of MPP is complex and evaluation of its true contribution is difficult in the clinical setting because of the large number of obstetric variables, some of which are hardly quantifiable. In this study we aimed to gather initial data on the forces executed by the accoucheur's thumb, index and middle fingers during MPP at the time of fetal head expulsion, quantify the duration of the intervention and investigate the timely interaction of the different components of MPP. Methods: Two bespoke right-handed measurement gloves (MG), with built in sensors, were designed and produced. The MG allowed the electronic real-time measurement of applied forces during MPP and transferred this data wirelessly to an integrated computer system. Sterile gloves were worn over the MG when used at the time of birth. The study was undertaken between January and December 2019. Singleton, term pregnant women having their first vaginal birth who provided a valid written consent were enrolled into this prospective pilot study. All deliveries were undertaken by one of two obstetricians experienced in MPP Results: Twenty women were enrolled. The mean duration of execution of MPP during the last contraction was 13.6 s. In 20% it lasted < 5 s. The overall means of the mean and maximum forces of the thumb, index and middle fingers were 26.7 N; 25.5 N; 20.2 N and 34.3 N; 32.6 N; and 27.6 N respectively. The onset of fingers and thumb activity was simultaneous in 13 cases (65%), while in seven (35%) deliveries the middle finger's force activity was initiated later. Conclusions: MPP during fetal head expulsion happens over a short period of time. In the majority of cases the thumb and fingers actions started simultaneously. There were differences in the duration of application and the forces executed by the fingers and thumb between the two practitioners, however this was only significant for thumb measurements. The results obtained will aid in improving further MPP modeling studies to optimize the technique
Genetics of Host Response to Leishmania tropica in Mice – Different Control of Skin Pathology, Chemokine Reaction, and Invasion into Spleen and Liver
Several hundred million people are exposed to the risk of leishmaniasis, a disease caused by intracellular protozoan parasites of several Leishmania species and transmitted by phlebotomine sand flies. In humans, L. tropica causes cutaneous form of leishmaniasis with painful and long-persisting lesions in the site of the insect bite, but the parasites can also penetrate to internal organs. The relationship between the host genes and development of the disease was demonstrated for numerous infectious diseases. However, the search for susceptibility genes in the human population could be a difficult task. In such cases, animal models may help to discover the role of different genes in interactions between the parasite and the host. Unfortunately, the literature contains only a few publications about the use of animals for L. tropica studies. Here, we report an animal model suitable for genetic, pathological and drug studies in L. tropica infection. We show how the host genotype influences different disease symptoms: skin lesions, parasite dissemination to the lymph nodes, spleen and liver, and increase of levels of chemokines CCL2, CCL3 and CCL5 in serum
Distinct genetic control of parasite elimination, dissemination, and disease after Leishmania major infection
Elimination of pathogens is the basis of host resistance to infections; however, relationship between persisting pathogens and disease has not been clarified. Leishmania major infection in mice is an important model of host–pathogen relationship. Infected BALB/c mice exhibit high parasite numbers in lymph nodes and spleens, and a chronic disease with skin lesions, splenomegaly, and hepatomegaly, increased serum IgE levels and cytokine imbalance. Although numerous gene loci affecting these disease symptoms have been reported, genes controlling parasites’ elimination or dissemination have never been mapped. We therefore compared genetics of the clinical and immunologic symptomatology with parasite load in (BALB/c × CcS-11) F2 hybrids and mapped five loci, two of which control parasite elimination or dissemination. Lmr5 influences parasite loads in spleens (and skin lesions, splenomegaly, and serum IgE, IL-4, and IFNγ levels), and Lmr20 determines parasite numbers in draining lymph nodes (and serum levels of IgE and IFNγ), but no skin or visceral pathology. Three additional loci do not affect parasite numbers but influence significantly the disease phenotype—Lmr21: skin lesions and IFNγ levels, Lmr22: IL-4 levels, Lmr23: IFNγ levels, indicating that development of L. major-caused disease includes critical regulations additional to control of parasite spread
Genetic Control of Resistance to Trypanosoma brucei brucei Infection in Mice
Trypanosoma brucei are extracellular protozoa transmitted to mammalian host by the tsetse fly. They developed several mechanisms that subvert host's immune defenses. Therefore analysis of genes affecting host's resistance to infection can reveal critical aspects of host-parasite interactions. Trypanosoma brucei brucei infects many animal species including livestock, with particularly severe effects in horses and dogs. Mouse strains differ greatly in susceptibility to T. b. brucei. However, genes controlling susceptibility to this parasite have not been mapped. We analyzed the genetic control of survival after T. b. brucei infection using CcS/Dem recombinant congenic (RC) strains, each of which contains a different random set of 12.5% genes of their donor parental strain STS/A on the BALB/c genetic background. The RC strain CcS-11 is even more susceptible to parasites than BALB/c or STS/A. In F2 hybrids between BALB/c and CcS-11 we detected and mapped four loci, Tbbr1-4 (Trypanosoma brucei brucei response 1–4), that control survival after T. b. brucei infection. Tbbr1 (chromosome 3) and Tbbr2 (chromosome 12) have independent effects, Tbbr3 (chromosome 7) and Tbbr4 (chromosome 19) were detected by their mutual inter-genic interaction. Tbbr2 was precision mapped to a segment of 2.15 Mb that contains 26 genes
Pd-catalysed amidation of 2,6-dihalopurine nucleosides. Replacement of iodine at 0 ºC
Pd-catalysed reactions of 2-Cl, 2-Br and 2-I derivatives of a 6-chloropurine nucleoside with benzamide have been compared, using Pd2dba3, Xantphos and Cs2CO3 in toluene, between 20 and 80 °C. The reactivity order was 2-I > 2-Br > 6-Cl ≫ 2-Cl. The 2-I substituent could be replaced even at 0 °C, under conditions disclosed here for the first time. On the other hand, the replacement of the chlorine atom at position 2 (2-Cl) required 110 °C
2008b) Organic pollutant contamination of the river Ticha Orlice as assessed by biochemical markers. Acta Vet Brno 77: 133–141
Abstract Havelková M., Z. Svobodová, J. Kolářová, J. Krijt, D. Némethová, J. Jarkovský, R. Pospíšil: Organic Pollutant Contamination of the River Tichá Orlice as Assessed by Biochemical Markers. Acta Vet. Brno 2008, 77: 133-141. This study used biochemical markers to assess contamination at two contaminated sites (Králíky and Lichkov) and one control site (Červená Voda) on the River Tichá Orlice, a left-side tributary of the River Elbe. The brown trout (Salmo trutta fario) was selected as an indicator species. Enzymes of the first stage of xenobiotic conversion, namely cytochrome P450 (CYP 450) and ethoxyresorufin-O-deethylase (EROD) in the liver were selected as biochemical markers. Blood plasma vitellogenin concentrations were used to evaluate xenoestrogenic effects of contamination. Results were compared with the most important inductors of these markers, i.e. with organic pollutants (PCB, HCH, HCB, OCS and DDT and their metabolites in fish muscle and with PAH concentrations in bottom sediments). The highest contamination with organic pollutants was at Králíky, and this was reflected in increased cytochrome P450, EROD activity and vitellogenin concentrations. Significant differences were demonstrated in EROD activity and vitellogenin concentrations between Králíky and Červená Voda (P < 0.001). At the most contaminated site (Králíky), a significant negative correlation (r s = -0.964) between EROD activity and vitellogenin concentrations was demonstrated. This relationship was discussed from the point of view of a possible induction or inhibition of the assessed biomarkers at persistently highly contaminated sites. Cytochrome P450, EROD, vitellogenin, Salmo trutta fario, PCB, river contamination The River Tichá Orlice (Czech Republic) is a tributary of the River Elbe. The River Tichá Orlice is 107.5 km long and its basin covers 755.4 km 2 . Broodstock of brown trout (Salmo trutta fario) and European grayling (Thymallus thymallus) from the upper reaches of the river and its tributary, the Kralický brook, have been used for artificial reproduction. Fish reproductive problems were detected for the first time in the early 1990s, including low effectiveness of spawning. The results of reproduction were not satisfactory and high losses of spawners were noticed. Monitoring the River Tichá Orlice and its tributary Kralický Brook has been proceeding since 1989. The presence of organic pollutants (PCB; DDT and its metabolites, HCB and HCH) and heavy metals in brown trout muscle have been investigate
DNA fingerprint analysis of drug resistant Mycobacterium tuberculosis strains isolated in the Czech republic
Analysis of stretch and stress distribution in pelvic floor structures during vaginal delivery using computer modeling
This work was supported by the project n. 182 Obstetrics 2.0 Virtual models for the prevention of injuries during childbirth realised within the frame of the Program INTERREG V-A: Cross-border cooperation between the Czech Republic and the Federal State of Germany Bavaria, Aim European Cross-border cooperation 2014-2020. The realisation is supported by financial means of the European Regional Development Fund (85 % of the costs) and the state budget of the Czech Republic (5 %).Female pelvic floor dysfunction, such as urinary incontinence, fecal urgency or pelvic organ prolapse, is very often associated with injuries of pelvic floor structures during childbirth. This trauma usually causes lifelong complications leading to poorer social or/and sexual life. The paper from Great Britain published that only 9.6 % of primipara and 31.2 % of sekundipara deliver with intact perineum [5]. In addition, the older study showed that 85 % women are suffering from injury of perineum during vaginal delivery [4]. Therefore, it is essential to understand the anatomy and physiology of these structures to avoid or at least to decrease the trauma of vaginal delivery. The computer modeling is a sophisticated tool how to achieve that
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