570 research outputs found

    MAT-731: MECHANICAL & DURABILITY PROPERTIES OF ENGINEERED CEMENTITIOUS COMPOSITES WITH DIFFERENT AGGREGATES

    Get PDF
    This paper presents the outcome of a study conducted to exhibit the effect of micro-silica sand and mortar sand on fresh, mechanical and durability properties of Engineered Cementitious Composites (ECCs). ECC is a ductile concrete characterized by strain hardening and multiple-cracking behavior under tension and shear. This study used locally available aggregates instead of standard micro-silica sand to produce cost-effective, sustainable and green ECC mixtures to be used for construction applications. ECCs prepared by both types of sands exhibited almost similar behaviour in terms of fresh, mechanical and durability properties which indicated the viability of producing ECC mixtures with mortar sand. In addition, the behaviour of a standard ECC can still be achieved when producing ECCs made of high volume fly ash (up to 70% cement replacement) along with local mortar sand. By employing results of this research, correlations were derived between mechanical and durability properties

    Ultrasonographic Appearance and Echo-pattern Characterization of Donkeys’ Internal Reproductive Organs

    Get PDF
    The current study was achieved to designate the accessory sex glands, ampullae and urethra of 25 healthy male donkeys using the ultrasonography. Animals were classified according to their age into young peri-mature (i.e. ≤2 years; n=7) and old mature (>3 years; n=18). The examination was done per rectum by using Magic 2200 scanner with a 6 MHz linear transrectal transducer. The position of each gland was allocated, and length and width were measured. The dimensions of prostate gland lobes and ampulla ductus deferens significantly differed between the examined groups. The echo-pattern analysis of vesicular gland and ampulla ductus deferens, in terms of mean pixel value (MPV), pixel intensity (PI) and pixel number (PN), significantly differed between premature and mature donkeys. Age was significantly correlated with all sex glands measurements. There was a substantial confident relationship between MPV and PI and the dimensions of vesicular and ampulla ductus deferens. In the meantime, PN was clearly negatively correlated with vesicular gland length and width. In conclusions, ultrasound is a feasible non-invasive diagnostic tool that could be used to characterize the accessory glands along the course of the pelvic urethra of male donkeys reared in Egypt. The addressed measures as well as acoustic physiognomies of the secondary sex organs are considered a promising guide in fertility potential prediction and/or the discrimination of the pathological conditions of male reproductive organs

    Elucidation of the effects of a high fat diet on trace elements in rabbit tissues using atomic absorption spectroscopy

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The mechanism of atherogenesis is not yet fully understood despite intense study in this area. The effects of high fat diet (HFD) on the changes of trace elements [iron (Fe), copper (Cu) and zinc (Zn)] in several tissues of rabbits have not been documented before. Thus, the aim of this study was to elucidate the changes in trace elements in several tissues of rabbits fed on HFD for a period of feeding of 10 weeks.</p> <p>Results</p> <p>The HFD group was fed a NOR rabbit chow supplemented with 1.0% cholesterol plus 1.0% olive oil. Fe, Cu and Zn concentrations were measured in four types of tissue from control and HFD rabbits using atomic absorption spectroscopy (AAS). Comparing HFD rabbits to control rabbits, we found that the highest percentage change of increase of Fe was 95% in lung tissue, while the lowest percentage change of increase of Fe was 7% in kidney tissue; the highest percentage change of decrease of Cu was 16% in aortic tissue, while the lowest percentage change of decrease of Cu was 6% in kidney tissue; and the highest percentage change of decrease of Zn was 71% in kidney tissue, while the lowest percentage change of decrease of Zn was 8% in lung tissue.</p> <p>Conclusions</p> <p>These results suggest that Fe plays a major role in atherogenesis; it may accelerate the process of atherosclerosis probably through the production of free radicals, deposition and absorption of intracellular and extracellular lipids in the intima, connective tissue formation, smooth muscle proliferation, lower matrix degradation capacity and increased plaque stability. Furthermore, inducing anemia in HFD rabbits may delay or inhibit the progression of atherosclerosis. Cu plays a minor role in atherogenesis and Cu supplements may inhibit the progression of atherogenesis, perhaps by reducing the migration of smooth muscle cells from the media to the intima. Zn plays a major role in atherogenesis and that it may act as an endogenous protective factor against atherosclerosis perhaps by reducing lesion Fe content, intracellular and extracellular lipids in the intima, connective tissue formation, and smooth muscle proliferation. These results suggest that it may be possible to use the measurement of changes in trace elements in different tissues of rabbits as an important risk factor during the progression of atherosclerosis.</p

    Fecal Lactoferrin As A Diagnostic and Prognostic Marker in Egyptian IBD Patients

    Get PDF
    Background: Inflammatory bowel diseases (IBD) are organic chronic inflammation of the gastrointestinal tract characterized by variable disease activity with repeated periods of remission and exacerbation. Irritable bowel syndrome (IBS) is prevalent in up to fifth of population; diarrhea type has the broadest differential diagnosis. To distinguish inflammatory versus functional disorder fecal biomarkers as fecal lactoferrin (FL), being non-invasive acute phase proteins produced by inflamed mucosa, can help to avoid invasive procedures. Objective: The aim of this study was to assess sensitivity and specificity of fecal lactoferrin as a non-invasive biomarker in Egyptian patients with IBD and to detect its role in assessment of disease severity. Patients and methods: This comparative case control study was held through one year duration. Patients were recruited from Internal Medicine and Hepatology Department at a University Hospital. 50 subjects were classified into 3 groups: Group I included 30 patients with inflammatory bowel disease, Group II included 10 patients with irritable bowel syndrome, Group III included 10 healthy subjects as control group. Results: fecal lactoferrin assay (FLA) levels were highest in patients with IBD in comparison with IBS patients and healthy group. Moreover FLA levels also correlated significantly with disease severity in patients with IBD as higher levels of FLA were found in patients with severe ulcerative colitis (UC) or Crohn`s disease. Conclusion: Fecal lactoferrin can be used to differentiate IBD from IBS with 96.7% sensitivity and 100% specificity at cutoff value of 37 ug/ml while at cutoff value 7.2 ug/ml FLA has 100% sensitivity and specificity in differentiating IBD patients from healthy subjects in Egyptian population. Yet it can’t differentiate ulcerative colitis versus Crohn’s disease

    REMOVAL OF FERRIC IONS (Fe+3) FROM NEUTRAL SOLUTIONS USING MODIFIED CHITOSAN

    Get PDF
    The object of this study is to assess the removal of Fe(III) ions from aqueous solutions onto modified chitosan. The effect of various parameters has been investigated by the following batch adsorption technique. The various variables studied include initial concentration of the adsorbate, agitation time, adsorbent dosage, kinetics, influence of temperature. The experimental data was fit well to the Freundlich isotherm. Thermodynamic parameters such as ΔH, ΔS and ΔG were calculated, indicating that the adsorption was spontaneous and endothermic nature

    Impaired endogenous fibrinolysis at high shear using a point-of-care test in STEMI is associated with alterations in clot architecture

    Get PDF
    © The Author(s) 2019Impaired endogenous fibrinolysis is an adverse prognostic biomarker in acute coronary syndrome (ACS). Abnormally dense in vitro fibrin thrombi have been demonstrated in ACS patients and related to hypofibrinolysis using cumbersome, laboratory-based methods. We aimed to assess endogenous fibrinolysis using a point-of-care technique and relate this to clot architecture. From patients with ST-segment elevation myocardial infarction (STEMI), venous blood was drawn immediately on arrival to assess thrombotic status. Blood was assessed using the point-of-care Global Thrombosis Test which measures occlusive thrombus formation under high shear and subsequently endogenous fibrinolysis (lysis time, LT). Two samples per patient were run in parallel. In one channel, the measurement was allowed to proceed as normal. In the other, after occlusion, thrombus was extracted, washed, fixed in glutaraldehyde, dried, sputter-coated, and assessed using scanning electron microscope. Endogenous fibrinolysis was strongly associated fibrin fibre thickness (p = 0.0001). As LT increased (less efficient fibrinolysis), the fibrin network of the thrombus was significantly more compact and dense, with thinner fibrin fibres and smaller gaps. Fibrin fibre thickness correlated inversely with LT (r = - 0.89, p = 0.001). Adverse clot architecture in vitro is directly related to impaired endogenous fibrinolysis using a relatively new point-of-care technique in patients with STEMI. This may transform the relevance of fibrin clot architecture from an off-line laboratory association to being directly relevant to endogenous fibrinolysis at the patient bedside, which could be used as a near-patient test to guide prognosis and assess the effect of treatment.Peer reviewedFinal Published versio

    Influence of Number of Implants and Attachment Type on Stress Distribution in Mandibular Implant-Retained Overdentures: Finite Element Analysis

    Get PDF
    AIM: This study aimed to compare the stresses generated by using two or four root form dental implants supporting mandibular overdentures that were retained with ball and locator attachments.METHODS: Under ANSYS environment, four 3D finite element models were prepared. These models simulated complete overdentures supported by two or four implants with either ball or locator attachments as a connection mechanism. The models’ components were created by CAD/CAM package then were imported to ANSYS. Load of 100 N was applied at the right premolar/molar region vertically and at an oblique angle of 110° from lingual direction.RESULTS: Within the conditions of this research, in all cases, it was found that cortical and cancellous bone regions were the least to be stressed. Also, the ball attachment produced higher stresses.CONCLUSION: Caps deformation and stresses are negligible in cases of using locator attachment in comparison to ball attachments. This may indicate longer lifetime and less repair/maintenance operations in implant overdentures retained by locator attachments. Although the study revealed that bone was insensitive to a number of implants or attachment type, it may be recommended to use two implants in the canine region than using four, where the locator attachments were found to be better

    Melasma and Associated Factors in Arar City, Kingdom of Saudi Arabia (KSA)

    Get PDF
    Melasma is a common dermatological disorder characterized by irregular brownish patches with unclear etiology and a variety of factors may be associated with its occurrence. Melasma patients suffer significant emotional and psychological problems making assessment of their quality of life is increasingly necessary. Aim of the study: This study was conducted to identify the frequency and factors associated with occurrence of Melasma in in Arar, KSA and its effect on some determinant of quality of life in the affected patients. Subjects and methods: A population based cross sectional study was conducted from January 2016 to January 2017. It included 470 individuals attended five randomly selected primary healthcare centers in Arar city in the Northern Province of Kingdom of Saudi Arabia and were selected by systemic random sampling. Data were collected by means of personal interview with the sampled population using a predesigned questionnaire. Results: Findings revealed that18.7 % of the studied population suffered from Melasma. Age and positive family history were significantly associated with the development of Melasma among the studied patients while gender, skin color, sun exposure and cosmetic use had no significant effect. Most of the studied determinants of quality of life were not affected by suffering from Melasma while lack of self-confidence was significantly associated with the presence of Melasma. Conclusion: less than on fifth (18.7%) of the studied patients suffered from Melasma. Age and positive family history are the most common associations. Melasma had a significant impact on self-confidence of the affected patients.Keywords: Melasma, risk factor, quality of life

    Pattern of Congenital Dislocation of the Hip in Arar City, Northern Saudi Arabia

    Get PDF
    Background: Developmental dysplasia of the hip (DDH) is one of the most widely discussed abnormalities in neonates. The etiology of DDH is unknown. There are many insights, however, from epidemiologic/demographic information. Aim of the study: To determine the incidence, risk factors and treatment modalities of congenital dislocation of the hip (CDH) in Arar city, Northern Saudi Arabia. Methods: This is prospective study involve 955(19100hips) infants referred to Arar central hospital. During the period from 1 January 2014, to 31 December 2016, each infant was evaluated by history taking, clinical and sonographic examination for hip abnormality. Results: The incidence of (CDH) was 3.1% (73.3% were females), 70.0% of the affected had positive family history and in 46.7% there was consanguinity between parents. In 80.0% there was regular follow up during pregnancy. 16.7% had history of oligohydramnios. Breech presentation was found in 26.7% and 15.0% delivered by caesarian section. First born children constituted 25.0%. The left hip joint was more affected( 41.6%) , the right hip joint affected in  28.3% and bilateral CDH were involved in 13.3%. In the studied cases, 40.0% of the infants were treated surgically, 30% conservatively, 16% by both and 14% were referred to higher centers. Conclusion and recommendations: CDH in Arar, Central hospital and by inference in Northern region of Saudi Arabia was found to be 3.1%. Awareness programs, routine neonatal hip joint examination at birth and up to one year of age as well as ultrasound examination of pelvis in high-risk babies are strongly recommended
    • …
    corecore