474 research outputs found
Determining radius of influence of the face in EPB shield tunneling by finite difference method
For the purpose of understanding the three-dimensional behavior of face tunnel, a
three-dimensional finite difference simulation model, which includes all relevant shield tunneling
components and allows for the modeling of the step-by-step construction process of the tunnel
advance. The soil-structure interaction in shield tunneling is investigated by numerical solution. The
results of three-dimensional ground displacements and stress pattern around a tunnel face and at the
ground surface are examined. Results obtained from these analyses indicate that the general threedimensional stress and displacement patterns around a tunnel heading are very different from that at
the plane strain transverse section. The distance required for the ground displacement to reach the
plane strain condition will depend on the amount of plasticity developed around the tunnel opening.
Consequently, face is the most important zone for the design engineer in EPB tunneling
An investigation on fish parasites in Hanna Wetland, Semirom, Isfahan Province
As a part of a major ecological study of Hanna Wetland, Semirum Region, Isfahan Province, parasitic infestation of 3 native and one introduced fish species were investigated. A total of 120 fish specimens were collected by both cast net and a series of gillnets between fall and winter 2007, and spring and summer 2008. Some of the observed parasites are reported for the first time as new host records of: Trichodina perforata on gill and skin of Carassius auratus auratus and three species of leeches namely: Glossiphonia heteroclite, Thromyzon tessulatum and Hemiclepsis marginata on the skin and fin bases of Capoeta damascina. Moreover, 14 internal and external parasites including: one protozoan; Ichthyophthirius multifiliis and two myxosporeans; Myxobolus varicorhini, Myxobolus sp., three monogeneans; Dactylogyrus lenkoran, Dactylogyrus intermedius and Gyrodactylus sp., two immature digeneans; Diplostomum spathaceum, Tylodephys sp., two mature digeneans; Allocreadium isoporum and A. layman, one unknown cyst, one Acanthocephalan; Acanthocephalorhynchoides sp., one cestoda; Khawia armeniaca. The highest prevalence of Diplostomum spathaceum (100%) was observed in Aphanius isfahanensis and Alburnus sp. However, the lowest prevalence was related to A. layman in Capoeta damascina in winter (0%), and autumn and spring (11%). Leeches infections were only observed in Capoeta damascina and Alburnus sp. in winter and summer, respectively. The maximum average (±SD) infection intensity belonged to K. armeniaca in intestine of C. damascina in spring (12.50±3.40, range: 8-16). Among the parasites identified in the region, D. spathaceum showed the highest mean (±SD) abundance (41.67±11.79) in C. auratus auratus in spring. In general, a relatively high diversity of fish parasitic fauna exists in this water body which could jeopardize fish populations and the whole ecosystem if the ecological status of the Hanna Wetland is neglected
Diagnosis of premature rupture of membranes by the detection of thyroid hormones in vaginal secretions
Background: Premature rupture of membranes (PROM) and preterm PROM (PPROM) are the rupture of the fetal chorioamniotic membranes before the onset of labor contractions. Objectives: To evaluate whether detection of thyroid hormones in vaginal washouts can be used to diagnose premature rupture of membranes (PROM). Patients and Methods: Total T4 (thyroxin), total T3 (triiodothyronine), and free T4 concentrations in vaginal washouts were analyzed in 45 women with the diagnosis of PROM and compared with 45 normal pregnancies (controls). A Student�s t-test was used for comparison of thyroid hormone values and a ROC curve was used for analyzing the diagnostic accuracy Results: There were no differences between the patients with PROM and the control women regarding maternal age, gestational age, and parity. The mean concentration of total T4 in the PROM group and the control subjects were 2.1 ± 1.3 jig/mL and 1.55 ± 0.58 jig/, respectively (P = 0.01). Total T3 concentration in the PROM group was significantly higher compared to the controls (1.28 ± 0.42 ng/ vs. 0.8 ± 0.26 ng/, P < 0.0001). Also, free T4 concentration was significantly higher in the PROM group as compared with the controls (0.026 ± 0.034 ng/ vs.0.007 ± 0.004 ng/, P < 0.0001). The ROC curve analysis showed that total T4=1.685 jig/ had a sensitivity of 62, specificity of 76, positive predictive value (PPV) of 71.8, and negative predictive value (NPV) of 66.7. Total T3 = 0.82 ng/ gave a sensitivity of 91, specificity of 64, PPV of 72, and NPV of 87.8. Free T4 = 0.01 ng/ gave a sensitivity of 51, specificity of 82, PPV of 74.2, and NPV of 62.7. The best cutoff values were total T4 = 1.685 ng/, total T3 = 0.82 ng/, and free T4 = 0.01 ng/. Conclusions: Detecting total T4, total T3, and free T4 in vaginal washouts of patients suspected of PROM suspected is a simple, available, rapid, and inexpensive method for the diagnosis of PROM. However, a combination of three tests is recommended. © 2015, Shiraz University of Medical Sciences
Production of Sn02 nano-particles by hydrogel thermal decomposition method
SnO2 is an important functional material having a wide range of applications in
gas sensors and optoelectronic devices. There is a great interest for finding new costeffective
and straight-forward methods for production of these particles. In this research,
hydrogel thermal decomposition method (HTDM) is used for production of high purity
SnO2nano-particles. Cost effective reactants and green routs of production are the advantages
of polysaccharide based hydrogel as starting material for this method. Visual
observations indicated that there is very little tendency for agglomeration in the
SnO2nano-particles produced by this method which can be considered as an advantage
for this method over other methods for production of SnO2nano-particles. SnO2nanoparticles
are also characterized by X-ray diffraction (XRD) in terms of purity and the
sizes. It is found that high purity SnO2nano-particles in the size range of 25 – 36 nm can
be produced by HTDM.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2068
Guillian-Barre syndrome , Childhood, Epidemiology, Electrodiagnosis, Clinical features, East Azarbaijan
ObjectiveThis study aims at determining the epidemiologic, presenting symptoms, clinical course and electrophysiologic features of childhood Guillain-Barre Syndrome (GBS) in the East Azarbaijan province over a period of five years.Materials & Methods All the patients, aged< 15 years, referred/admitted to Tabriz Children Hospital with GBS between January 2001 and December 2005 were investigated.ResultsOne hundred and twelve subjects were enrolled during this period. The average annual incidence rate was 2.21 per 100000 population of children agedConclusion The axonal type of GBS is a relatively common form of childhood GBS occurring in East Azerbaijan.
Myxobolus spp. (Myxosporea: Myxobolidea) from fishes of the Zayandeh-rud River (Esfahan, Iran); new hosts and locality record
In a parasitic survey of the native and introduced fishes in the Zayandeh-rud River, 5 Myxobolus spp. were found in the gills, fins and skin of examined fish specimens. They include M. varicorhini from fin and M. samgoricus from skin of Capoeta damascina, M. musajevi from gills of Capoeta capoeta gracilis, Myxobolus cristatus from Capoeta aculeata, and M. saidovi from Alburnus sp. Data on the location in the hosts comparing with previous records are provided. The epidemiological importance of Myxobolus spp. in Zayandeh-rud River is also presented. In the present paper the occurrence of five Myxobolus spp. all from endemic fishes from Zayandeh-rud River (a new locality) are recorded from two new hosts; Capoeta damascina, Capoeta aculeata. M. varicorhini and M. saidovi are recorded for the first time from Iranian freshwater fishes
Proton-Coupled Electron-Transfer Mechanism for the Radical Scavenging Activity of Cardiovascular Drug Dipyridamole
Dipyridamole (DIP) is a well-known pharmaceutical drug used as a coronary vasodilator and anti-platelet agent in clinics for treating several cardiovascular diseases. Primarily, the therapeutic effects of the drug are attributed to its antioxidant potency. In this research, we aim to declare the unknown antioxidant mechanism of DIP as well as its potent chain-breaking antioxidant activity in polar aqueous medium inside the cells, using different experimental methods and theoretical quantum calculations. Data demonstrated the higher antioxidant capacity of DIP against ROS and free radicals in polar cell's interior. DIP is capable of generating long living and noninvasive DIP• radicals in oxidant condition that leads to an effective “chain-breaking antioxidant” activity. Quantum computational data indicated that DIP antioxidant has more favorable ionization potential than trolox which means DIP has higher antioxidant activity. Also, data showed that the direct hydrogen-transfer is not a favorable process to construct DIP• because of high barrier energy, though electron-transfer process can more easily to produce DIP•+ with the lowest barrier energy. Altogether, the electron donating potency of DIP to reduce ferric ion, having the low anodic oxidation peak potential, producing long lived stable DIP• radicals and protecting myoblast cells from oxidation, proposed the excellent “chain-breaking antioxidant” potency via electron-transfer mechanism of this vasodilator DIP drug in polar aqueous medium
Cryoprotectants and their changes in cabbage aphid, Brevicoryne brassicae (Hem.: Aphididae)
Cabbage aphid, Brevicoryne brassicae (L.), is an important pest of cabbage, especially ornamental cabbages, due to its voracity and population build-up on these plants in wintertime. The cryoprotectants of B. brassicae and their changes were investigated during the cold seasons. Adult aphids were collected monthly on ornamental cabbages from October 2008 through May 2009. The amount of sugars and polyols were measured by high performance liquid chromatography (HPLC) and the amount of glycogen was spectrophotometrically determined. The identified compounds were as follows: glucose, mannitol, myo-inositol and trehalose. Mannitol, myo-inositol and trehalose were significantly correlated with average temperature. The total amount of these compounds increased from the lowest amount (11.90 ± 3.07 µmol/g f.w.) in October to its highest (55.8 ± 8.83 µmol/g f.w.) in the coldest month, January. There appears that these three compounds, especially mannitol, play important roles in enhancing cold tolerance of B. brassicae during cold seasons. The amount of glycogen showed no significant differences during those months and varied from 4.8 ± 0.58 mg/g f.w. in October to 3.3 ± 0.98 mg/g f.w. in December. There was no significant correlation between glycogen and the cryoprotectants
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