Factors associated with preventive behaviours of COVID-19 among hospital staff in Iran in 2020: an application of the Protection Motivation Theory.

This study was conducted to predict the preventive behaviours of healthcare workers (HCWs) towards COVID-19 based on the Protection Motivation Theory (PMT). This cross-sectional and analytical study was conducted on 761 HCWs in Hamadan, Iran, using multi-stage random sampling. The preventive behaviours against COVID-19 among HCWs were assessed at a relatively desirable level. Based on the PMT, threat and coping appraisal were predictors of protection motivation to conduct COVID-19 preventive behaviours (P<0.001). The intention was also predictive of COVID-19 preventive behaviours (P<0.001). Consideration of personnel's self-efficacy and their knowledge regarding the effectiveness of protective behaviours in designing staff training programmes are recommended.

Phononic thermal conductivity in silicene: the role of vacancy defects and boundary scattering.

We calculate the thermal conductivity of free-standing silicene using the phonon Boltzmann transport equation within the relaxation time approximation. In this calculation, we investigate the effects of sample size and different scattering mechanisms such as phonon-phonon, phonon-boundary, phonon-isotope and phonon-vacancy defect. We obtain some similar results to earlier works using a different model and provide a more detailed analysis of the phonon conduction behavior and various mode contributions. We show that the dominant contribution to the thermal conductivity of silicene, which originates from the in-plane acoustic branches, is about 70% at room temperature and this contribution becomes larger by considering vacancy defects. Our results indicate that while the thermal conductivity of silicene is significantly suppressed by the vacancy defects, the effect of isotopes on the phononic transport is small. Our calculations demonstrate that by removing only one of every 400 silicon atoms, a substantial reduction of about 58% in thermal conductivity is achieved. Furthermore, we find that the phonon-boundary scattering is important in defectless and small-size silicene samples, especially at low temperatures.

Prevalence of Neospora caninum and Toxoplasma gondii Antibodies in Bulk Milk of Dairy Cattle, Mashhad, Iran.

Neospora caninum (N. caninum) and Toxoplasma gondii (T. gondii) are both obligate intracellular protozoan parasites, which have gained considerable attention because of their role in bovine abortion. This study aimed to detect anti-N. caninum and -T. gondii in bulk milk of dairy cattle, Mashhad, Iran. The bulk milk samples were collected from July 2014 to June 2015 and analyzed for anti-N. caninum and -T.gondii antibodies using enzyme-linked immunosorbent assay (ELISA). Out of 123 bulk milk samples, 44 (35%), 14 (11.38%), and 3 (2.4%) samples had N. caninum, T. gondii, and mixed infection with these two parasites, respectively. According to the results, the prevalence of N. caninum infection was more than T.gondii infection in dairy cattle of Mashhad, Iran.

Molecular Detection of Hepatozoon canis in Dogs of Ardabil Province, Northwest of Iran.

Hepatozoon species are protozoan parasites that infect some animals such as birds, reptiles, amphibians, and carnivores. Previous studies performed on canine hepatozoonosis in Iran have never used molecular techniques for diagnosis of this disease. The main objective of the present study was to detect Hepatozoon canis in the blood of dogs using polymerase chain reaction (PCR) method and sequencing. A total of 104 blood samples were collected from dogs of Meshginshahr County (Ardabil Province), and DNA was extracted from blood samples by dint of DNG-plus Extraction Kit. Then, 18S rRNA gene was amplified by using the conventional PCR methods. PCR products yielded an amplicon of the approximate length of 897 bp for all the positive samples. Twenty-four out of the 104 (23.07%) samples were found to be positive for H. canis. This rate of infection is relatively high among dogs in Ardabil Province. Sequence analysis confirmed the molecular identity of 99% of the samples by comparison with GenBank profiles. This is the first report of molecular detection of H. canis from Iran.

Comparison of effects of age and sex on serum protein electrophoretic pattern in one-humped camels (Camelus dromedarius) in Semnan, Iran.

The aim of this study was to evaluate the influence of age and sex on the concentration of total serum protein measured by the biuret method and protein fractions determined using cellulose acetate electrophoresis in apparently healthy camels (Camelus dromedarius). Blood samples were collected from 21 camels (12 males and 9 females). The camels were further divided into two groups: 12 young camels at the age of 3 months to 2 years and 9 adult camels at the age of 3-15 years. Cellulose acetate electrophoresis of serum proteins identified five protein fractions in adult camels as young camels, these five protein fractions include albumin, α1 and α2, ß and γ-globulins. In adult camels, serum levels (g/l) of total protein, albumin, α1-globulins, α2-globulins, ß-globulins and γ-globulins were 80.9±3.10, 42.9±3.10, 1.3±0.22, 2.2±0.30, 11.8±0.30 and 22.6±0.20, respectively. However, in young camels, these levels (g/l) were 66.8±2.90, 40.2±2.40, 1.0±0.14, 2.6±0.30, 10.6±0.80 and 12.3±1.20, respectively. The albumin/globulin (A/G) ratio was 2.08±0.28 in adult camels and 3.77±0.53 in young ones. The mean serum concentrations of total protein and γ-globulins were significantly (P<0.05) higher and the A/G ratio was significantly lower in adult camels compared to young camels. The mean concentrations of γ-globulins were significantly higher and the A/G ratio was significantly (P<0.05) lower in females compared to male camels. The results of the present study indicate a significant effect of age and sex on the concentrations of some of the serum protein fractions in dromedary camels.

Canine visceral leishmaniasis: a comparative study of real-time PCR, conventional PCR, and direct agglutination on sera for the detection of Leishmania infantum infection.

Canine visceral leishmaniasis (CVL) is endemic in northwestern Iran. This study aimed to compare real-time PCR, conventional PCR, and the direct agglutination test (DAT) for the diagnosis Leishmania infantum infection in 167 serum samples of domestic dog. Bone marrow was used for parasitological examination (smears and/or culture) in symptomatic visceral leishmaniasis, and serum was used for detection of L. infantum kinetoplast DNA (kDNA) by both conventional PCR and real-time PCR, while anti-L. infantum antibodies in sera were measured by DAT. The sera were collected from 37 symptomatic and 112 asymptomatic dogs during April to May 2011. Eighteen presumed negative samples were obtained from healthy dogs kept in non-endemic areas with no history of CVL and used as controls. All 18 samples were negative by DAT and Dipstick rK39. DAT confirmed previous exposure to L. infantum for all 149 serum samples collected from symptomatic and asymptomatic dogs in CVL endemic areas of Iran. Among the 37 symptomatic dogs, 20 (54%), 25 (67.6%), 36 (97.3%), and 37 (100%) showed L. infantum infection by parasitological methods, conventional PCR, real-time PCR, and DAT (≥ 1:80), respectively. Of 112 asymptomatic dogs, 79 (70.5%), 111 (99.1%), and 112 (100%) were shown to be positive by conventional PCR, and DAT (≥ 1:80), respectively. For ethical reasons, no asymptomatic or healthy control dogs were examined by parasitological methods. Three (16.7%) control dogs were positive by real-time PCR, but were negative by DAT, dipstick rK39, and conventional PCR methods. Parasitemia levels were measured by real-time PCR targeting kDNA using SYBR(®) green assay. This quantitative technique detected infection in 89.9% (150/167) of the domestic dogs that harbored L. infantum kDNA, ranging from 0.01 49 to 310.1 parasites/ml. The average was 16.60 parasites/ml. A good agreement (0.97) was found between real-time PCR and DAT at ≥ 1:80 titer, used as cut-off value by Kappa analysis. Thus, real-time PCR as a quantitative PCR assay on serum samples represents a valuable tool for initial diagnosis of CVL when whole blood is not available.

Intensive Care Unit nosocomial sinusitis at the Rasoul Akram Hospital: Tehran, Iran, 2007-2008.

BACKGROUND: Nosocomial rhino sinusitis causes major problems in all Intensive Care Units (ICUs). OBJECTIVE: To describe incidence, epidemiologic, clinical manifestations, and microbiologic findings in ICUs admitted cases with nosocomial sinusitis. METHODS#ENTITYSTARTX00026; MATERIALS: A prospective, cross sectional study done in Pediatric & Adult ICUs in Rasoul Akram Hospital; Tehran Iran (2007-2008). Para-nasal sinus computed tomography (CT) was performed in all adults with fever of unknown origin (FUO) within 48h of admission and repeated thereafter (4-7 days). Infectious sinusitis was diagnosed by microbiological analysis of sinus fluid aspirates. RESULTS: Acute bacterial nosocomial sinusitis proved in 82% (51/ 63) of all cases. Head trauma was the most common cause; (n = 22, 45%) of cases. The results of culture were positive for 45 cases (82%). Of 45 culture positives, 19 yielded Gram negative organisms (41%) and 9 (22%) gave Gram positives (S. aureous, Streptococus spp). The remainders (n = 17, 37%) consisted of mixed aerobic/anaerobic bacteria. Seven cases, were positive in gram staining of sinus drainage and these were positive in culture for S. pneumonia (n = 5), Hemophilus influenza (n = 2). The type of organisms were not related to Glasgow Coma Scale in cases (P = 0.3). CONCLUSION: Nosocomial organisms isolated were quite different from community acquired rhino sinusitis cases. Investigation of CT scan and drainage of Para-nasal sinuses would be helpful in undiagnosed FUO cases, especially in traumatic patients. Optimal treatment usually consists of removal of the tubes, mobilizing the patient, and administration the broad-spectrum antibiotics.

Evaluation of an interferon-gamma release assay in young contacts of active tuberculosis cases.

In a cross-sectional study in a hospital in Tehran in 2006-08 the QuantiFERON-TB interferon-gamma release assay (QTB) was compared with the tuberculin skin test (TST) in 59 young people (aged < 20 years) with close contact with immunocompetent cases of proven pulmonary tuberculosis. After 1 year follow-up 10 subjects had progressed to tuberculosis disease and received treatment; TSTwas positive in 30% and QTB in 100%. Of the 49 non-progressive subjects, TST was positive in 10.4% and QTB in 16.3%. The agreement between TST and QTB assay in non-progressive subjects was poor (K = 0.43). False positive and false negative rates for TST were 40.0% and 9.3% respectively; positive and predictive values were 60.0% and 90.7%. We suggest adding the interferon assay to the skin test in the decision to perform chest X-ray or to start chemoprophylaxis at least in younger subjects (aged < 20 years).

Evaluation of an interferon-gamma release assay in young contacts of active tuberculosis cases

In a cross-sectional study in a hospital in Tehran in 2006-08 the QuantiFERON[Registered]-TB interferon-gamma release assay [QTB] was compared with the tuberculin skin test [TST] in 59 young people [aged<20 years] with close contact with immunocompetent cases of proven pulmonary tuberculosis. After 1 year follow-up 10 subjects had progressed to tuberculosis disease and received treatment; TST was positive in 30% and QTB in 100%. Of the 49 non-progressive subjects, TST was positive in 10.4% and QTB in 16.3%. The agreement between TST and QTB assay in non-progressive subjects was poor [Kappa=0.43]. False positive and false negative rates for TST were 40.0% and 9.3% respectively; positive and predictive values were 60.0% and 90.7%. We suggest adding the interferon assay to the skin test in the decision to perform chest X-ray or to start chemoprophylaxis at least in younger subjects [aged<20 years]

Effect of thermal bond excitations on the critical properties of covalent Ising networks.

We introduce a bond-diluted Ising model with temperature-dependent concentration of bonds, which is intended to simulate the excitations of bond degrees of freedom as in covalently bonded network liquids arising from the thermal electronic transitions between bonding and antibonding electronic states. The critical behavior of this simplified model system, called the thermalized-bond Ising model, is investigated in terms of the Monte Carlo simulation results of finite-size regular Ising systems, as input for the method of chemical potentials that is generally used to obtain the thermodynamic properties of annealed impurity models. A finite-size scaling analysis of the susceptibility and the fourth-order cumulant results in a reliable estimation of the renormalized critical exponents. The exponents are found to be consistent with the phenomenological renormalization relations, due to Fisher, despite the temperature-dependent bond dilution.

Bacterial infections in children with visceral leishmaniasis: observations made in Kerman province, southern Iran, between 1997 and 2007.

Cases of human visceral leishmaniasis (VL) are often found to have bacterial infections. Between 1997 and 2007, 60 cases of VL were admitted to the paediatric ward of the Afzalipour Medical Centre, which forms part of the Kerman University of Medical Sciences, in southern Iran. On admission, the 60 cases (39 boys and 21 girls), each of which was confirmed by the demonstration of amastigotes in a bone-marrow aspirate, had a mean (S.D.) age of 48.8 (44.4) months and a mean (S.D.) erythrocyte sedimentation rate of 53.2 (34.2) mm/h. Twenty-five (42%) of the cases (14 boys and 11 girls) were found to have bacterial infections. Urinary infections (seen in 36% of the cases with bacterial infection) were the most common, followed by blood (28%), respiratory (16%), gastro-intestinal (12%) and skin infections (8%). Despite treatment of all the VL cases with meglumine antimoniate, four (7%) died on the paediatric ward, all four having concurrent bacterial infections. The leucopenia and immunosuppression associated with VL probably facilitate the development of fatal bacterial co-infections. The prompt diagnosis and treatment of both the VL and any bacterial co-infections should therefore reduce mortality among VL cases.

Bone blood flow and vascular reactivity.

Blood flow is essential for normal bone growth and bone repair. Like other organs, the regulation of blood flow to bone is complex and involves numerous physiologic mechanisms including the sympathetic nervous system, circulating hormones, and local metabolic factors. Our studies addressed the following questions: (1) Which endogenous vasoconstrictor agents regulate in vivo blood flow to bone? (2) Does a decrease in bone vascular reactivity to vasoconstrictor hormones account for the increase in blood flow during bone healing? (3) Does the endothelium influence bone arteriolar function? An intact bone model was developed in the rat to assess hormonal regulation of in vivo bone blood flow and in vivo bone vascular reactivity. An isolated, perfused bone arteriole preparation was employed to characterize the responsiveness of small resistance-size arterioles (diameter < 100 microm) to vasoconstrictor hormones and to evaluate the role of the vascular endothelium to modulate vascular smooth muscle reactivity. Our results indicate that: (1) though exogenous endothelin is a potent constrictor of the in vivo bone vasculature, endogenous endothelin does not actively regulate in vivo blood flow; (2) the increase in blood flow to a bone injury site is not due to a decrease in bone vascular sensitivity to norepinephrine, and (3) isolated bone arterioles of young rats are very sensitive to vasoconstrictor hormones but exhibit only modest endothelium-mediated vasodilation.

Angiotensin II-induced constrictions are masked by bovine retinal vessels.

PURPOSE: To unmask the vasoconstricting effect of angiotensin II (Ang II) on retinal smooth muscle by studying its interaction with endothelium-derived paracrine substances. This study focused specifically on determining the changes in vascular diameter and the release of endothelial-derived vasodilators, nitric oxide (NO) and prostaglandin (PG) I2, from isolated retinal microvessels. METHODS: Bovine retinal central artery and vein were cannulated, and arterioles and venules were perfused with oxygenated/heparinized physiological salt solution at 37 degrees C. This ex vivo perfused retinal microcirculation model was used to observe the contractile effects of Ang II on arterioles and venules of different diameters. The NO and PGI2 synthase inhibitors, 1-NOARG and flurbiprofen, respectively, were used to unmask Ang II vasoconstriction; the changes in vascular diameters were then measured. Enzyme immunoassays were used to measure the release of cGMP (an index of NO release) and 6-keto-PG-F1alpha (a stable metabolite of PGI2) from isolated bovine retinal vessels. RESULTS: Topically applied Ang II (10(-10) M to 10(-4) M) caused significant (P < 0.05) arteriolar and venular constrictions in a dose-dependent manner, with the smallest retinal arterioles (7+/-0.2 microm luminal diameter) and venules (12+/-2 microm luminal diameter) significantly more sensitive than larger vessels. After the inhibition of endogenous NO and PGI2 synthesis by 1-NOARG and flurbiprofen, respectively, the vasoconstriction effects of Ang II became more pronounced. Again, the smallest vessels tested were significantly more sensitive, and synthesis of endothelial-derived relaxing factor (EDRF), therefore, may be most important in these vessels. Vasoactive doses of Ang II (10(-10) M to 10(-4) M) caused a dose-dependent increase in the release of NO and PGI2 from isolated bovine retinal vessels, indicating that the increase in EDRF may nullify direct Ang II-induced vasoconstriction. Interestingly, intraluminal administration of Ang II caused only vasodilation. CONCLUSIONS: This study demonstrates that the retinal vascular endothelium acts as a buffer against the vasoconstricting agent Ang II via release of vasodilators NO and PGI2, and the vasoconstriction effects due to Ang II are most prominent in the smallest diameter vessels.