Adsorption of lead by Microalgae Chaetoceros Sp. and Chlorella Sp. from Aqueous Solution

Introduction: Using bio-sorbents is regarded as one of the effective methods to remove heavy metals. Therefore, this study aimed to investigate Pbadsorption from contaminated water by Chaetoceros sp. and Chlorella sp. algae. Materials &Methods: This experimental study was conducted in a batch reactor. The amount of Pbadsorption by Chaetoceros sp. and Chlorella sp. algae was studied under such conditions as different adsorbent dosages (0.2, 0.5, 1.5 and 2 g/L), different pH (3, 4, 5, 6, 7, 8), different temperatures (20, 25, 30, 35, 40 °C), different contact times (30, 60, 90, 180, 360 minutes), different particle sizes (20, 40, 60, 100, 140 mesh) and different Pb concentrations(20, 40, 60 mg/L). Then adsorption isotherms and kinetic models of metal ions were determined based on Langmuir and Freundlich isotherms as well as first and second order kinetic models. Results: The efficiency of Pb removal by Chlorella sp. and Chaetoceros sp. algae was reported 78% and 60% respectively. The maximum adsorption was observed at optimal conditions including 25°C, pH of 6, 180 minutesof contact time, particle size of 20 mesh, 1.5 gr/L of adsorbent and 20 mg/L concentration of Pb.Chlorella algae was observed to remove Pb more than Chaetoceros algae. Based on the study results, Pbadsorption by Chlorella algae complies with Langmuir adsorption isotherm model, whereas Chaetoceros algae follows Freundlich model. The kinetic models of algae adsorption followed a second order equation. Conclusion: The study findings revealed that Chlorella algae can be effectively used in order to adsorb Pb from contaminated water due to its high efficiency of Pb adsorption

Buoyant microplastics in freshwater sediments – How do they get there?

The accumulation of microplastics (MPs) in the sediments of a stormwater treatment pond was studied to gain knowledge on how these facilities protect the natural environment against this emerging pollutant. Thirteen sediment samples were analyzed for MPs down to 10 μm, mapping the pattern of accumulation in the pond. The average abundance in terms of MP-number and mass was 11.8 μg kg−1 and 44,383 item kg−1, respectively. They were rather unevenly distributed, with concentrations varying up to two orders of magnitude within the pond, showing that a trustworthy quantification of MPs retained by such units must rely on many and well-distributed subsamples. Buoyant MPs made up 95.4 % of the MP-mass and 83.5 % of the MP-number and in most of the sampled locations, polypropylene dominated the polymer fingerprint, followed by polyethylene. No spatial pattern in the distribution of MPs in the pond was identified. Instead, the MP content correlated to the organic matter and silt content, indicating that the processes leading to deposition could be similar. A computational fluid dynamics model was set up and used to simulate the transport mechanisms governing the conveyance of MPs in the pond from water to sediments. The results showed that the combination of advection and dispersion were likely the driving mechanism for buoyant (and non-buoyant) MPs to get in contact with the sediment bed and spread over the pond. Once in contact with the sediments, the MPs would have some probability of being permanently incorporated and hereby preventing them from entering the downstream aquatic environment.</p

Comparative Study of Internal Assessment in the Department of Environmental Health for the School of Public Health in Kerman University of Medical Sciences, Iran, during 2008-2013

Background & Objective: The aim of this study was to compare the condition in the Department of Environmental Health Engineering from different viewpoints and determining its changes during the period under study, as well as reviewing their strengths and weaknesses, opportunities and threats to enhance the level of quality. Methods: This was a descriptive study that was done for six years from 2008 untill 2013 by Environmental Health Department. Goals, faculty members, students, courses and curriculum, the teaching, learning and graduates groups were evaluated. Then criteria and indicators were developed. Results: Interviews, observation, questionnaires and check list for each evaluation criteria according to their importance in comparison with other markers were weighted. Finally, the overall results obtained at the minimum and maximum weight of each criterion was determined, based on scores according to Likert scale. Conclusion: Environmental Health Department has been earned 302 out of the total 361 points. State of Department of Environmental Health, a total of six years was satisfactory and has been growing. The only unfavorable case was the lack of credit given to groups that operate in the area of group decision making is not straight. Identifying the bottlenecks recommended to be taken in order to focus on improving the challenging situations. Keywords Internal evaluation Environmental Health Department Kerman University of Medical Sciences Ira

What is hiding below the surface – MPs including TWP in an urban lake

Inland lakes play an important role as habitats for local species and are often essential drinking water reservoirs. However, there is limited information about the presence of microplastics (MPs) in these water bodies. Thirteen sediment samples were collected across a Danish urban lake to map MPs, including tyre wear particles (TWP). The lower size detection limit was 10 µm. MPs were quantified as counts, size, and polymer type by Fourier-transform infrared microspectroscopy (µFTIR) and mass estimated from the 2D projections of the MPs. As TWP cannot be determined by µFTIR, counts and sizes could not be quantified by this technique. Instead, TWP mass was determined by pyrolysis gas chromatography mass spectrometry (Py-GC/MS). The average MP abundance was 279 mg kg−1 (µFTIR), of which 19 mg kg−1 (Py-GC/MS) were TWP. For MPs other than tyre wear, the average MP count concentration was 11,312 counts kg−1. Urban runoff from combined sewer overflows and separate stormwater outlets combined with outflow from a wastewater treatment plant were potential point sources. The spatial variation was substantial, with concentrations varying several orders of magnitude. There was no pattern in concentration across the lake, and the distribution of high and low values seemed random. This indicates that large sampling campaigns encompassing the entire lake are key to an accurate quantification. No preferential spatial trend in polymer characteristics was identified. For MPs other than TWP, the size of buoyant and non-buoyant polymers showed no significant difference across the lake, suggesting that the same processes brought them to the sediment, regardless of their density. Moreover, MP abundance was not correlated to sediment properties, further indicating a random occurrence of MPs in the lake sediments. These findings shed light on the occurrence and distribution of MPs, including TWP, in an inland lake, improving the basis for making mitigation decisions.</p

Evaluation the Effect of Photon Beam Energies on Organ at Risk Doses in Three- Dimensional Conformal Radiation Therapy 1

Abstract: As regards, the selection of appropriate energy in radiotherapy tumors that are placed in non-homogen areas is important, so the aim of the present study is evaluating the effect of 6 and 15MV photon beam energies on dose distribution in 3D-CRT for lower esophageal and rectal cancers. 12 patients with lower esophageal cancer and 12 patients with rectal cancer respectively, with the prescription dose of 7000 cGy and 5040 cGy were studied. For treatment of esophagus the three-field technique and for treatment of rectum the four-field technique was used. In the thoracic area, the spinal cord and in the pelvis, the bladder and head of femurs were considered as OARs. For comparing the results, all parameters used for treatment planning except the photon beam energy were kept constant. After performing the treatment planning with two different energies in each region, the received dose rate of spinal cord, bladder and head of femurs as OARs and dose distribution in PTVs were studied. The results of this study showed that the difference between doses received by OARs in 6MV and 15MV therapeutic plans, resulted 5.2, 5.06 and -9.14%, respectively. Also the PTVs received dose difference of esophagus and rectum in the performed therapeutic plans with energy of 6 MV than energy of 15MV is 1.52 and -0.63%, respectively. We found that using of low energy photons in lower esophageal treatment and high energy photons in the rectal treatment provides the better dose coverage. Finally, with such as therapeutic plans the cumulative dose of organs at risk will be reduced

The Use of Microalgae for Coupling Wastewater Treatment With CO2 Biofixation

Production and emission of CO2 from different sources have caused significant changes in the climate, which is the major concern related to global warming. Among other CO2 removal approaches, microalgae can efficiently remove CO2 through the rapid production of algal biomass. In addition, microalgae have the potential to be used in wastewater treatment. Although, wastewater treatment and CO2 removal by microalgae have been studied separately for a long time, there is no detailed information available on combining both processes. In this review article, microalgae-based CO2 biofixation, various microalgae cultivation systems,̄ and microalgae-derived wastewater treatment are separately discussed, followed by the concept of integration of CO2 biofixation process and wastewater treatment. In each section, details of energy efficiency and differences across microalgae species are also given

Intravenous immunoglobulin treatment for acute attacks in myelin oligodendrocyte glycoprotein antibody disease

BACKGROUND: The potential therapeutic benefit of intravenous immunoglobulins (IVIGs) for acute attacks of myelin oligodendrocyte glycoprotein antibody disease (MOGAD) is unknown. OBJECTIVE: The objective was to describe the outcomes of IVIG treatment for acute MOGAD attacks. METHODS: A retrospective observational study involving seven tertiary neuroimmunology centers. Data collection included patients' demographics, Expanded Disability Status Scale (EDSS), and visual acuity (VA) before the attack, at the nadir of the attack before IVIG treatment, and at follow-up visits ⩾3 months after treatment. RESULTS: Thirty-nine patients were included, of which 21 (53.8%) were female. The median age was 23 years (range 5-74 years), and the median disease duration was 4 months (range 0-93 months). The most common type of attack treated with IVIG was isolated optic neuritis (ON) (unilateral n = 14, bilateral n = 5, associated with transverse myelitis (TM), n = 1), followed by acute disseminated encephalomyelitis (ADEM) (n = 8), multifocal (n = 7), TM (n = 3), brainstem (n = 1), and other encephalitis (n = 1). A significant improvement in both the EDSS and VA measures was observed at follow-up compared to the time of IVIG treatment initiation (p < 0.0001 for both outcome measures). CONCLUSION: IVIG may be an effective treatment option for acute MOGAD attacks. Further prospective studies are warranted to validate our results

Iterative Learning Control Methods for Hybrid Wearable Robots

In this dissertation, iterative learning control methods for a hybrid exoskeleton to produce sitting-to-standing and walking in people with paraplegia are investigated. The hybrid exoskeleton combines a lower limb powered exoskeleton and functional electrical stimulation (FES). Limited research has been done to design control methods that provide shared modulation of FES and the powered exoskeleton. A major technical challenge to the implementation of control algorithms is their need to identify a user's musculoskeletal dynamics. Further, currently, setting desired regulation points or desired limb trajectories during sitting-to-standing and walking movements is a daunting task as it requires separate and coordinated design for each lower-limb. An inaccurate regulation of set-points or desired trajectories can possibly cause uncoordinated standing-up movements, potentially destabilizing the user. Goal: The goal of this research is to design robust and adaptive control algorithms for hybrid exoskeletons that overcome the difficulty in model identification, can dynamically allocate the shared use of FES and the powered exoskeleton, and produce coordinated joint movements. Objectives: The primary objective of this research is to develop robust control methods that iteratively learn modeling uncertainties in the hybrid exoskeleton (i.e., addressing model identification), while facilitating allocation of FES and motor input (i.e., resolving actuator redundancy) in the hybrid exoskeleton. The proposed control methods are experimentally validated for a sitting to standing task with the hybrid exoskeleton. The experiments are performed on human participants with no disabilities and a participant with spinal cord injury. The tasks that are accomplished to achieve the objectives are listed as: 1- Design and implement time-invariant desired joint trajectories by using virtual constraints for sitting-to-standing and walking motion 2- Derive and experimentally validate a robust control method that uses an arbitrarily switched allocation strategy to coordinate motor and FES. 3- Derive a control method that iteratively learns the system nonlinear dynamics and control gains. 4- Using an optimal and cooperative model predictive control method, instead of switched control, to allocate between motors and FES

Molecular Epidemiology Study of Suspected Meningitis Cases in Tehran and Alborz Provinces

Background and Objective: Meningitis is a medical emergency requiring immediate diagnosis and treatment. Bacterial and viral causative agents play a role in meningitis appearance to various degrees. Thus, effective vaccines and antimicrobial and supportive treatments need to be developed and monitoring should be performed in different regions for controlling this disease. Most previous studies have focused on a small number of bacterial agents, and the viral profile of this disease is not precisely monitored in Iran, especially in overpopulated regions. Moreover, limited new applied methods with high precision and sensitivity for the detection of meningitis agents indicate the necessity of determining meningitis agents by rapid molecular methods, which was the aim of the current study.     Materials and Methods: Overall, 148 samples obtained from suspected meningitis patients from different age groups admitted to Tehran and Karaj hospitals were evaluated by new methods involving specific primers for 16s rRNA, PCR, and Real-time PCR tests.  Results:  It was found that viral infection, especially infection with human enterovirus, remains the main cause of meningitis in Iran, and Neisseria meningitides is the most common bacterial isolate detected in meningitis cases. Conclusion: Despite the decreasing trend in meningitis incidence, according to World Health Organization recommendation, implementing an enhanced surveillance system to provide high-quality data on the epidemiological profile of meningitis per each region is necessary

The significance of the left atrial volume index in prediction of atrial fibrillation recurrence after electrical cardioversion

Introduction: Electrical cardioversion (ECV) is a safe method for the treatment of atrial fibrillation. It seems that left atrial volume index (LAVI) could be a good marker in predicting the success of ECV. The purpose of this study is to assess of the significance of LAVI measurement before ECV in predicting the recurrence of the AF. Methods: Fifty-one patients with AF, selected for ECV were studied in the cardiology department of Tabriz University of medical sciences. The clinical and demographic data of all the patients were obtained. Echocardiography was performed before and also three months after ECV. Patients were separated into two groups: those who maintained SR and those with relapse of AF diagnosed by clinical manifestations and electrocardiography (ECG). Results: Sinus rhythm (SR) was maintained in 76.5 percent of the patients following the three months after ECV. The age, sex and the body mass index (BMI) were not significantly different between SR and AF groups. Two groups showed no significant differences considering pre-ECV medical history including medications and systemic diseases. The initial LAVI of SR group was 42.21±12.4 mL/m2 and AF group was 96.08±52.21 mL/m2, the initial LAVI was significantly different between two groups (P = 0.000). The LAVI of SR group decreased significantly (5.69±0.74 mL/m2) after three months, LAVI decreased from 42.21 ± 12.4 ml/m2 to 37.51 ± 10.52 mL/m2. (P = 0.000). The cut-off point of LAVI value in predicting the maintenance of SR was 55 mL/m2. Conclusion: The present study indicates that LAVI is a powerful forecaster of the recurrence of AF after ECV. The LAVI measurement could be a useful method in the selection of the patients with AF for ECV