Clinical predictors of Covid-19 mortality in a tertiary hospital in Lagos, Nigeria: A retrospective cohort study.

Background: The predictors of mortality among patients presenting with severe to critical disease in Nigeria are presently unknown. Aim: The aim of this study was to identify the predictors of mortality among patients with COVID-19 presenting for admission in a tertiary referral hospital in Lagos, Nigeria. Patients and Methods: The study was a retrospective study. Patients' sociodemographics, clinical characteristics, comorbidities, complications, treatment outcomes, and hospital duration were documented. Pearson's Chi-square, Fischer's Exact test, or Student's t-test were used to assess the relationship between the variables and mortality. To compare the survival experience across medical comorbidities, Kaplan Meir plots and life tables were used. Univariable and multivariable Cox-proportional hazard analyses were conducted. Results: A total of 734 patients were recruited. Participants' age ranged from five months to 92 years, with a mean ± SD of 47.4 ± 17.2 years, and a male preponderance (58.5% vs. 41.5%). The mortality rate was 9.07 per thousand person-days. About 73.9% (n = 51/69) of the deceased had one or more co-morbidities, compared to 41.6% (252/606) of those discharged. Patients who were older than 50 years, with diabetes mellitus, hypertension, chronic renal illness, and cancer had a statistically significant relationship with mortality. Conclusion: These findings call for a more comprehensive approach to the control of non-communicable diseases, the allocation of sufficient resources for ICU care during outbreaks, an improvement in the quality of health care available to Nigerians, and further research into the relationship between obesity and COVID-19 in Nigerians.

Immersion vaccines against Yersinia ruckeri infection in rainbow trout: Comparative effects of strain differences.

The protective effects of autogenous and commercial ERM immersion vaccines (bacterins based on Yersinia ruckeri, serotype O1, biotypes 1 and 2) for rainbow trout (Oncorhynchus mykiss) were compared in order to evaluate whether the use of local pathogen strains for immunization can improve protection. In addition, the effect of the bacterin concentration was established for the commercial product. Following sublethal challenge of vaccinated and non-vaccinated control fish with live bacteria, we followed the bacterial count in the fish (gills, liver and spleen). The expression of genes encoding immune factors (IL-1ß, IL-6, IL-8, IL-10, IFN-γ, MHCI, MHCII, CD4, CD8, TCRß, IgM, IgT, IgD, cathelicidins 1 and 2, SAA and C3) and densities of immune cells in organs were recorded. Both vaccines conferred protection as judged from the reduced bacterial load in exposed fish. Innate immune genes were upregulated in all groups following bacterial challenge but significantly more in non-vaccinated naive fish in which densities of SAA-positive immune cells increased. Immunoglobulin genes were upregulated on day 5 post-challenge, and fish vaccinated with the high commercial bacterin dosage showed increased IgM levels by ELISA on day 14 post-challenge, reflecting that the vaccine dosage was correlated to protection. In conclusion, both vaccine types offered protection to rainbow trout when exposed to live Y. ruckeri and no significant difference between commercial and autogenous vaccines was established.

Covid 19: A Prospective Observational Study on the Cutaneous Manifestations of Patients in Lagos, Nigeria.

BACKGROUND: Cutaneous manifestations of COVID-19 have been documented from Europe, USA, and China but none from Africa to date. Skin findings among Africans differ from Caucasians and it is important to report these in Nigerians with COVID-19. METHODS: A prospective observational review involving patients seen at the Emergency triage, and Isolation wards of the Lagos University Teaching Hospital. Demographic and clinical data were captured; skin and appendages were examined by a dermatologist between 0800hrs and 1600hours to minimise visual errors of artificial light masking cutaneous lesions. RESULTS: Of 235 participants, 17 (7.23%) had recent onset skin rash, with 7 (41.2%) experienced itching and 11 confirmed with COVID-19. There was a male: female ratio of 97:43 (2.3:1) among COVID-19 patients. Cutaneous findings were seen in 12 (5.1%) participants, with the face and trunk mostly affected and acne plus papular eruptions predominating. There was no significant relationship between COVID-19 and recent onset skin rash (χ2, p = 0.87). Only 2 of the 17 participants had a previously existing dermatoses ((χ2, p = 0.84). There was no significant relation between use of medications and onset of rashes (χ2, p = 0.72) or between those with co-morbidities and onset of rashes (χ2, p = 0.51). CONCLUSION: Cutaneous manifestations were found among Nigerian patients with SARS-CoV-2 infection. Most presented with pruritus and papular eruptions and no morphologic pattern was demonstrated. Physicians and dermatologists need to be aware and look out for skin changes in SARS-CoV-2 infection as they may be early pointers to COVID-19. Keywords: Cutaneous findings, manifestations, Skin, COVID-19, Nigeria.

CONTEXTE: Des manifestations cutanées du COVID-19 ont été documentées en Europe, aux Etats-Unis et en Chine, mais aucune en Afrique à ce jour. Les manifestations cutanées chez les Africains diffèrent de celles des Caucasiens et il est important de les signaler chez les Nigérians atteints de COVID-19. MÉTHODES: Une étude observationnelle prospective impliquant des patients vus au triage des urgences et dans les services d'isolement de l'hôpital universitaire de Lagos. Les données démographiques et cliniques ont été saisies ; la peau et les appendices ont été examinés par un dermatologue entre 8h00 et 16h00 pour minimiser les erreurs visuelles de la lumière artificielle masquant les lésions cutanées. RÉSULTATS: Sur 235 participants, 17 (7,23 %) ont présenté une éruption cutanée d'apparition récente, dont 7 (41,2 %) ont eu des démangeaisons et 11 ont été confirmées par le COVID-19. Il y avait un rapport hommes/femmes de 97:43 (2,3:1) parmi les patients atteints de COVID-19. Des signes cutanés ont été observés chez 12 (5,1 %) participants, le visage et le tronc étant les plus touchés, avec une prédominance de l'acné et des éruptions papuleuses. Il n'y avait pas de relation significative entre le COVID-19 et les éruptions cutanées d'apparition récente (χ2, p = 0,87). Seulement 2 des 17 participants avaient une dermatose déjà existante ((χ2, p = 0,84). Il n'y avait pas de relation significative entre la prise de médicaments et l'apparition d'éruptions cutanées (χ2, p = 0,72) ou entre les personnes présentant des comorbidités et l'apparition d'éruptions cutanées (χ2, p = 0,51). CONCLUSION: Des manifestations cutanées ont été constatées chez les patients nigérians atteints d'une infection par le SRAS-CoV-2. La plupart d'entre eux présentaient un prurit et des éruptions papuleuses et aucun modèle morphologique n'a été mis en évidence. Les médecins et les dermatologues doivent être attentifs et rechercher les modifications cutanées dans l'infection par le SRAS-CoV-2, car elles peuvent être des signes précurseurs du COVID-19. MOTS CLÉS: Résultats cutanés, manifestations, Peau, COVID-19, Nigéria.

One-way sound propagation via spatio-temporal modulation of magnetorheological fluid.

This manuscript details the possibility of achieving one-way sound propagation using a smart fluid such as magnetorheological fluid (MRF) by subjecting it to a spatio-temporally varying magnetic field. The local speed of sound in MRF is dependent on applied magnetic field as demonstrated in several experimental works and this property of MRF has been leveraged, in this work, to induce one-way bandgaps. Initially, a general wave equation pertaining to fluid with space-and-time-varying material properties was derived. Assuming plane wave propagation in one dimension, an approximate Floquet solution was imposed and the dispersion relationship was obtained. A comprehensive finite element analysis was conducted and good agreement was noted between the numerical and theoretical dispersion relations. It was concluded that space-time periodic modulation of fluid density and local sound speed is necessary to induce asymmetry in the band diagram around the ω axis. The feasibility of real-world implementation using MRF has been discussed. A parametric study detailing the effect of viscosity on the one-way bandgaps has been undertaken. It was found that one-way bandgaps formed at relatively lower frequencies are more robust to viscous corruption. A real-world implementation may be feasible if the viscosity of MRF is less than 3000 Pa-s.

Conjugate unscented transformation-based uncertainty analysis of energy harvesters.

This article presents a probabilistic approach to investigate the effect of parametric uncertainties on the mean power, tip deflection, and tip velocity of linear and nonlinear energy harvesting systems. Recently developed conjugate unscented transformation algorithm is used to compute the statistical moments of the output variables with multidimensional Gaussian uncertainty in parameters. The principle of maximum entropy is used to construct the probability density function of output variables from the knowledge of obtained statistical moments. The probability density functions for mean power were significantly complicated in shape with two and three distinct peaks for the nonlinear monostable and nonlinear bistable harvesters, respectively. Monte-Carlo simulations with N = 8 × 104 samples for monostable harvester and N = 6.5 × 104 samples for bistable harvester were used for validating the probability density functions. It is concluded that conjugate unscented transformation methodology affords a significant computational advantage without compromising accuracy. In addition, using conjugate unscented transformation method, we show that the dependence of mean power on parameters (excitation frequency, excitation amplitude, etc.), when multidimensional uncertainties are present, is decidedly different relative to a purely deterministic trend. The discrepancy in predicted power between the deterministic and uncertain trends for the monostable harvester, for instance, reach a maximum of 100%, 234%, and 110% for base frequency, base acceleration, and magnet gap, respectively. The deterministic trend consistently overestimates the harvested power relative to the uncertain trends. This work, therefore, may have applications in evaluating "worst case scenario" for harvested power. The major advantage of the presented methodology relative to extant techniques in energy harvesting literature is the accurate and computationally effective applicability to multidimensional uncertainty in parameters.

A sub-cc nonlinear piezoelectric energy harvester for powering leadless pacemakers.

A miniature nonlinear piezoelectric energy harvester is developed to power state of the art leadless cardiac pacemakers from cardiac motions. The energy harvester is integrated in the leadless pacemaker and is connected to the myocardium. The energy harvester converts myocardial motions to electricity to power leadless pacemakers. The energy is stored in a battery or supercapacitor and is used for pacing. The device is composed of a bimorph piezoelectric beam confined in a gray iron frame. The system is assembled at high temperature and operated at the body temperature. The mismatch in the coefficients of thermal expansion of the beam and the frame causes the beam to buckle in body temperature. This intentional buckling makes the beam unstable and improves the power production and robustness of the device. Having high natural frequency is a major problem in microelectromechanical systems energy harvesters. Considering the small size of the energy harvester, 0.5 cm3, the natural frequency is expected to be high. In our design, the natural frequency is lowered significantly using a buckled beam and a proof mass. Since the beam is buckled, the design is bistable and nonlinear, which could increase the output power. In this article, the device is analytically modeled, and the natural frequencies and mode shapes of the energy harvester are analytically derived. The terms corresponding to geometric nonlinearities are included in the electromechanical coupled governing equations. The simulations show that the device generates sufficient electricity to power leadless pacemakers.

Nanoscale plasmonically enhanced photodetector based on a gold nanoring.

A nanoscale germanium-gold Schottky photodetector (PD) is proposed based on a nanoring supporting localized surface plasmon excitation. A design methodology is presented based on maximizing resonant transmission power throughput of light from the active region of the PD. Numerical calculations show significant field enhancement of about 200 times in the near-field zone inside of the nanoring, which is utilized to compensate the responsivity decrease due to PD active region volume shrinkage, providing the responsivity of 338 mA/W at a 1310 nm detection wavelength. In addition, the incident wavelength is detected in about one-seventh of the absorption length of bulk germanium, yielding about 33% of the external quantum efficiency. The ratio of responsivity to the active region volume of the PD is calculated to be approximately 100 times that of similar studies.

Modeling and analysis of optical properties of a gold nanoring based on electric and magnetic dipoles.

The optical behavior of a plane-wave excited gold nanoring (NR), originated from localized surface plasmon resonance is modeled by two coupled electric- and magnetic-point dipoles. Considering the extinction cross-section spectrum, it is found that the electric-dipole effect is dominant in comparison with the magnetic-dipole effect although the magnetic-dipole signature is observable in the near-field response of the NR. In addition, the far-field electromagnetic radiation pattern of the NR verifies the corresponding radiation pattern of the point dipoles. The numerical simulation near-field results are in agreement with the proposed electric- and magnetic-dipole theory.

Comparison antinociceptive activity of the aqueous methanolic extracts of Salvia Hypoleuca and Phytolacca americana in mice.

OBJECTIVES: Anti-nociceptive activity of aerial parts of Phytolacca (P.) americana and Salvia Hypoleuca were investigated, using the hot plate method in mice. MATERIALS AND METHODS: Antinociceptive activity of aerial parts of Phytolacca americana and Salvia Hypoleuca were investigated using the hot plate method. In addition, the effect of its aerial parts on morphine dependence was investigated in mice. After induction of dependence by morphine, different concentrations of plants aerial parts extract were injected to treated groups. To assess morphine withdrawal, mice were injected naloxone (5 mg/kg) i.p. on the 5th day. After four consecutive days of morphine injection, withdrawal syndrome was assessed by placing each mouse in a 30 cm high glass box and recording the frequency of escape jumps for 60 minutes. RESULTS: The aqueous methanolic extract of aerial parts of P. Americana and S. Hypoleuca produced a statistically significant increase in pain threshold after 30 min of i.p. injection of extract, in comparison with the control groups, at adose of 190 and doses of 500, 1000 and 1500 mg/kg (p < 0.001) respectibility. The activity was comparable to that of morphine (30 mg/kg i.p., p > 0.05). The anti-nociceptive activity of P. Americana and S. Hypoleuca increased until the 60th min (p < 0.05 compared to morphine). CONCLUSIONS: The results of this study support the extensive use of S. Hypoleuca and P. americana in Western Asia and America. The LD50 of extracts S. Hypoleuca and P. americana following a 14 days acute toxicity study were calculated to be a bout 1800 and 208 mg kg-1 i.p. respectability.

Predictive factors of response to phase I complete decongestive therapy in upper extremity lymphedema following breast carcinoma in Iran.

Post-mastectomy chronic lymphedema as a complication of breast cancer treatment is primarily managed with Complete Decongestive Therapy (CDT). We examined various factors for correlating with results of Phase I CDT treatment in controlling the upper extremity lymphedema. Study population consisted of patients with lymphedema referred to the Lymphedema Clinic of the Iranian Breast Cancer Research Center for control of arm edema. After obtaining the demographic and clinical data, patients were treated with CDT for 2 - 3 weeks. One hundred and thirty seven patients (mean age +/- SD; 53.5 +/- 10 years) were studied. In 48.7% of patients, the affected arm was the dominant limb. Fifty percent of patients experienced lymphedema during the first year after surgery, and mean duration of lymphedema was 35 +/- 43 months. Mean volume reduction was 43% +/- 14.87% (p = 0.03). There was a significant relationship between the percent of volume reduction and initial lymphedema volume (p=0.003) as well as duration of lymphedema (p=0.002). Our results demonstrate that Phase I CDT treatment is very effective for post mastectomy lymphedema, and particularly if it is provided in earlier stages of disease. In addition, CDT also has an important role in reducing clinical symptoms and improving limb function. In the appropriate setting, Phase I CDT has been an effective method of controlling post mastectomy lymphedema in this Iranian population.

[Periapical regeneration. About one case of necrotic immature tooth treated with mineral trioxide aggregate (MTA)]. / La régénération périapicale. A propos d'un cas de dent immature nécrosée traitée au minéral trioxyde aggregate (MTA).

Therapeutic of apexification with calcium hydroxide has been extensively used in clinical practice, but this technique has some drawbacks (long duration of treatment, weakening of the radicular walls). Different studies have proposed to close the apex opened with MTA (Mineral trioxide Aggregate) which is biocompatible, bacteriostatic, this material induces regeneration of the periapical region through the formation of cementum, bone and periodontal ligament (1, 2). This case report describes the technique of setting up in a single step of the Mineral trioxide Aggregate as an apical barrier for immature permanent roots. This method has allowed us an immediate apical sealing and a root canal filling and a coronary restore permanently as soon as possible. The radiological control confirmed that this type of apexification could be successful with periapical regeneration ad-integrum.

The effect of participatory community-based diabetes cares on the control of diabetes and its risk factors in western suburb of Yasouj, Iran.

This study aimed to investigate whether a community-based participatory diabetes care program could efficiently improve diabetic care and reduce its risk factors. To induce a participatory approach, a local group was established in partnership with academics, local leaders, health providers and public representatives. The group conducted community needs assessment and priority setting process. Diabetes was identified as the first priority health problem in this area. A total of 2569 30- to 65-year-old residents were screened for diabetes and 405 of them took part in a 13-week nutrition education and physical exercise intervention. Out of 1336 high-risk individuals, 17% had fasting blood sugar (FBS) ≥126 mg/dl and 13.5% with FBS between 110 and 125 mg/dl. Percentages of participants with triglycerides (TG) ≥150 mg/dl and cholesterol ≥200 mg/dl were 33.8% and 23.5%, respectively. After completion of the intervention, the mean FBS, HbA1C, TG and cholesterol were decreased significantly. Although systolic and diastolic blood pressure and body mass index were decreased too, the differences were not statistically significant. The mean physical activity increased and consumption of fried foods and saturated oil decreased significantly. The results suggest that participatory community-based care could be a feasible model for control of diabetes and its risk factors.

Antinociceptive activity and effect of methanol extract of Salvia limbata on withdrawal syndrome in mice.

OBJECTIVES: Salvia (S.) is an important genus consisting of about 900 species in the Lamiaceae family. They are several reports that some Salvia spp. has effects on the central nervous system (CNS). The present experiments were undertaken to study the protective effect of S. limbata on the development of dependence to morphine in mice. MATERIAL AND METHODS: Antinociceptive activity of aerial parts of S. limbata was investigated using the hot plate method. In addition, the effect of its aerial parts on morphine dependence was investigated in mice. After induction of dependence by morphine, different concentrations of plant aerial parts extract were injected to treated groups. To assess morphine withdrawal, mice were injected naloxone (5 mg/kg) i.p. on the 5th day. After four consecutive days of morphine injection, withdrawal syndrome was assessed by placing each mouse in a 30 cm high glass box and recording the frequency of escape jumps for 60 minutes. RESULTS: Animal receiving acute treatment with morphine displayed dependence. The animals treated with different extract concentrations could decrease frequency of escape jumps in number or decrease development of morphine dependence. Addiction was observed following naloxone administration. Methanol extract of S. limbata produced a statistically significant inhibition of pain induced by hot plate latency at 500, 1000 and 1500 mg/kg i.p. A significant increase in pain threshold was observed after 30 and 60 min (p < 0.001). The activity was comparable to that of morphine (30 mg kg(-1) i.p., p > 0.05). The anti-nociceptive activity of S. limbata increased until the 60th min (p < 0.05 compared to morphine). CONCLUSIONS: S. limbata extract produced statistically significant inhibition of pain and development of morphine dependence in mice.

Incorporation of Lactobacillus casei in Iranian ultrafiltered Feta cheese made by partial replacement of NaCl with KCl.

Probiotic Iranian ultrafiltered Feta cheese was produced from ultrafiltration of milk with a volumetric concentration factor of 4.5:1. The heat-treated retentates were inoculated with 10(7) cfu of Lactobacillus casei LAFTI L26/mL. A mesophilic-thermophilic mixed culture of Lactococcus lactis ssp. lactis, Lactococcus lactis ssp. cremoris, and Streptococcus thermophilus was also used. Three percent (wt/wt) salt with different ratios of NaCl:KCl (100% NaCl, 50% NaCl:50% KCl, 75% NaCl:25% KCl, and 25% NaCl:75% KCl) were used in cheese formulation. The viability of L. casei was determined in treatments during the ripening period (90d at 5°C) within 15-d intervals. The pH, titratable acidity, and redox potential changes were monitored throughout the mentioned period. The mean pH drop rate, mean acidity increase rate, and mean redox potential increase rate were calculated at the end of the storage period. Also, total nitrogen, water-soluble nitrogen, lactic acid, and acetic acid concentrations, and syneresis and sensory characteristics of the product were measured during the mentioned period every 30d. The maximum viability of L. casei was observed within d 15 to 30 of the ripening period in the treatment containing the lowest amount of sodium. Addition of KCl enhanced syneresis. Cheeses with NaCl alone and with only 25% replacement by KCl have the highest sensory acceptability.

Phylogenetic status of brown trout Salmo trutta populations in five rivers from the southern Caspian Sea and two inland lake basins, Iran: a morphogenetic approach.

Interrelationships, origin and phylogenetic affinities of brown trout Salmo trutta populations from the southern Caspian Sea basin, Orumieh and Namak Lake basins in Iran were analysed from complete mtDNA control region sequences, 12 microsatellite loci and morphological characters. Among 129 specimens from six populations, seven haplotypes were observed. Based on mtDNA haplotype data, the Orumieh and southern Caspian populations did not differ significantly, but the Namak basin-Karaj population presented a unique haplotype closely related to the haplotypes of the other populations (0·1% Kimura two-parameter, K2P divergence). All Iranian haplotypes clustered as a distinct group within the Danube phylogenetic grouping, with an average K2P distance of 0·41% relative to other Danubian haplotypes. The Karaj haplotype in the Namak basin was related to a haplotype (Da26) formerly identified in the Tigris basin in Turkey, to a Salmo trutta oxianus haplotype from the Aral Sea basin, and to haplotype Da1a with two mutational steps, as well as to other Iranian haplotypes with one to two mutational steps, which may indicate a centre of origin in the Caspian basin. In contrast to results of the mtDNA analysis, more pronounced differentiation was observed among the populations studied in the morphological and microsatellite DNA data, except for the two populations from the Orumieh basin, which were similar, possibly due to anthropogenic causes.

Osteoprotegerin changes in saliva and serum of patients with knee osteoarthritis. / Cambios de osteoprotegerina en saliva y suero de pacientes con osteoartritis de rodilla.

OBJECTIVE: The scope of this study was to assess salivary and serum osteoprotegerin (OPG) levels in knee osteoarthritis (OA). METHODS: Serum and saliva OPG levels of 30 knee OA and 30 matched healthy controls in this cross-sectional study was assessed by ELISA. Knee pain was assessed by WOMAC. Data were analyzed by Student's t-test, Spearman correlation test and ROC. RESULTS: The mean serum but not saliva OPG level was lower in knee OA than that of the healthy group. WOMAC negatively correlated with serum OPG (r = -0.501; P = 0.000). The serum OPG cutoff value was 237.5 pg/ml for the diagnosis of knee OA. CONCLUSIONS: As serum OPG was lower in knee OA and negatively correlated with WOMAC, it seems that detection of OPG in serum but not in saliva may be a probable marker to the diagnosis of knee OA. KEY MESSAGES: Osteoprotegerin decreases in knee osteoarthritis.

Thin Split Thickness Skin Grafting on Human Acellular Dermal Matrix Scaffold for the Treatment of Deep Burn Wounds.

BACKGROUND: Use of AlloDerm™ is highly suggested for the treatment of deep burns and burn sequela reconstruction. Scar formation and contracture are recognized as long-term consequences of split-thickness skin autografting, which is applied for full-thickness burn injuries. Mature fibroblasts, in the absence of dermis, seem to secrete collagen in the reformed scar pattern. OBJECTIVE: To process AlloDerm™ from fresh allograft and use it as a dermal substitute for covering deep wounds in burn patients and evaluate its effectiveness. METHODS: In this case-series, 7 patients with deep burn wounds involving different locations on the body surface were exposed to combined AlloDerm™ (processed from fresh human allograft) with thin split thickness skin autograft on it. On the 5th post-operative day, wound dressings were changed to evaluate the graft survival with the human acellular dermal matrix scaffold. To determine the skin profiles, follow-ups continued for at least 6 months. RESULTS: The results showed excellent graft take, good elasticity, acceptable thickness, and little contracture and scarring according to fix surgeon assessment in 6 patients. Graft rejection happened only in one patient with chronic electrical injury. CONCLUSION: AlloDerm™ derived from cadaver skin and combination of it with thin split thickness skin auto grafting constitute a cost-effective and favorable option for the treatment of deep burn wounds in our center, considering the increased tendency of the population towards organ donation in the event of brain death.

Investigation of fine nanoparticles syngas catalyst (POM) considering their various morphology.

Ni/SiO2 fine nanoparticles were prepared by coprecipitation method using various nonionic surfactants as templates with Tylose as a binder dispersant. Scanning Electron Microscope (SEM) and X-ray Diffraction (XRD) have been used to study the templates influence on the morphology of the produced samples. Although the phase structure remained as a tetrahedron amorphous cristobalite-sin-SiO2 (101,100), rhombohedron and cubic NiO, but samples with different morphology (homogeneous nano spherical, nano rose flower and nano cubic shapes) have been achieved. These fine nanoparticles as syngas catalysts in Partial Oxidation of Methane to Hydrogen and Carbon Monoxide (POM) have been studied. Because of high Hydrogen production, it is a candidate to be a green fuel. A fixed-bed reactor at P = 1 atm, T = 800 degrees C, H2/CO = 1.8, GHSV (CH4) = 6000/hr and BET = 25, 63.5 and 87.1 m2/gr have been used as POM catalyst. From other hand these fine compounds could be converted to metallic nanotube (nanofiber) at above 850 degrees C and also bamboo shape tip mode carbon nanotube by thermal chemical vapor deposition at 800 degrees C. Transmission Electron Microscopy confirmed the metallic nanotube or single nano crystal growth. The Raman spectroscopy of all samples has been studied to confirm the different formation of Ni-Si. Choosing different templates for production of these nanoparticles could create width range of medical and industrial applications.

Effect of Fe2+ and Fe3+ ions on human plasma cholinesterase activity.

OBJECTIVES: Metals such as iron are needed for physiological functions of the body. However, their excess may cause serious damage including poisoning. The effects of Fe2+ and Fe3+ ions on human plasma cholinesterase activity were investigated. MATERIAL AND METHODS: Plasma were obtained (n = 24) from healthy male volunteers, and treated with five various concentrations of Fe2+ and Fe3+ ions. Activity of butyryl cholinesterase (BChE) was assayed according to colorimetric EIIman procedure. The activity was calculated as micromole of hydrolyzed substrate, per minute in each ml. RESULTS: Both ferric (Fe3+) and ferrous (Fe2+) ions significantly decreased the BChE activity in all tested concentrations. The effect of ferric (Fe3+) ions on the reduction of plasma enzyme activity was more pronounced than ferrous (Fe2+) ions (p < 0.001, respect to control group). CONCLUSIONS: The present paper represents the effect of Fe2+ and Fe3+ ions on ButyrylChE activity in human plasma. It reveals that both ions suppress BChE activity.