Optimization of staged bioleaching of low-grade chalcopyrite ore in the presence and absence of chloride in the irrigating lixiviant: ANFIS simulation

In this investigation, copper was bioleached from a low-grade chalcopyrite ore using a chloride-containing lixiviant. In this regard, firstly, the composition of the bacterial culture media was designed to control the cost in commercial application. The bacterial culture used in this process was acclimated to the presence of chloride in the lixiviant. Practically speaking, the modified culture helped the bio-heap-leaching system operate in the chloridic media. Compared to the copper recovery from the low-grade chalcopyrite by bioleaching in the absence of chloride, bioleaching in the presence of chloride resulted in improved copper recovery. The composition of the lixiviant used in this study was a modification with respect to the basal salts in 9 K medium to optimize the leaching process. When leaching the ore in columns, 76.81 % Cu (based on solid residues of bioleaching operation) was recovered by staged leaching with lixiviant containing 34.22 mM NaCl. The quantitative findings were supported by SEM/EDS observations, X-ray elemental mapping, and mineralogical analysis of the ore before and after leaching. Finally, Adaptive neuro-fuzzy inference system (ANFIS) was used to simulate the operational parameters affecting the bioleaching operation in chloride–sulfate system.     

Intravenous immunoglobulin G treatment increases live birth rate in women with recurrent miscarriage and modulates regulatory and exhausted regulatory T cells frequency and function

Exhausted T cells and regulatory T (Treg) cells have been recently proposed to be new risk factors for recurrent miscarriage (RM). Intravenous immunoglobulin G (IVIG) treatment reported to modulate various immune cells. In this study, the effects of IVIG on the frequency and function of exhausted T cells, exhausted Tregs, and Treg cells, as well as pregnancy outcome in women with unexplained RM (URM), were investigated. Ninety-four pregnant women with RM were enrolled. At the time of positive pregnancy, blood samples were drawn. Forty-four patients with URM were included as IVIG receiving treated group and received 400 mg/kg of IVIG and the rest fifty patients were considered as a control group and received no IVIG administration. IVIG was given intravenously every 4 weeks during 32 weeks of gestation. Blood samples of patients were collected after the latest administration. Exhausted T cells, exhausted Tregs, and Treg cells were evaluated pre- and posttreatment in both groups. IVIG induced a significant decrease in the frequency of exhausted Tregs population and function as well as a significant increase in Treg cells population, however, IVIG failed to affect population and the function of exhausted T cells. Pregnancy outcome was successful in IVIG treated women (86.3%) and were significantly different (P = 0.0006) in compared with the untreated URM subjects (42%). Therefore, employing of IVIG increases Treg cells and diminishes exhausted Tregs responses in RM patients with cellular immune anomalies throughout the pregnancy. Immunemodulatory effects of IVIG are probably associated with successful pregnancy outcome.     

Tank bioleaching of copper from combined flotation concentrate and smelter dust

Bioleaching studies were conducted to evaluate the extraction of copper from combined flotation concentrate and smelter dust using two different dust-addition strategies, non-fractional (simultaneously with concentrate) and fractional (step-wise dust addition) in stirred tank reactors. The highest copper extraction obtained with the fractional dust addition was up to 94% while extraction using the non-fractional method leveled off at approximately 44%. Thus, an increased copper recovery of about 50% was achieved with the fractional dust-addition method. It seems that the main reason for increased copper recovery using fractional dust addition could be the control and prevention of chalcopyrite passivation (according to SEM/EDS, XRD, and quantitative mineralogy data). This leads to its improved dissolution.     

Large deforming buoyant embolus passing through a stenotic common carotid artery: a computational simulation

Arterial embolism is responsible for the death of lots of people who suffers from heart diseases. The major risk of embolism in upper limbs is that the ruptured particles are brought into the brain, thus stimulating neurological symptoms or causing the stroke. We presented a computational model using fluid-structure interactions (FSI) to investigate the physical motion of a blood clot inside the human common carotid artery. We simulated transportation of a buoyant embolus in an unsteady flow within a finite length tube having stenosis. Effects of stenosis severity and embolus size on arterial hemodynamics were investigated. To fulfill realistic nonlinear property of a blood clot, a rubber/foam model was used. The arbitrary Lagrangian-Eulerian formulation (ALE) and adaptive mesh method were used inside fluid domain to capture the large structural interfacial movements. The problem was solved by simultaneous solution of the fluid and the structure equations. Stress distribution and deformation of the clot were analyzed and hence, the regions of the embolus prone to lysis were localized. The maximum magnitude of arterial wall shear stress during embolism occurred at a short distance proximal to the throat of the stenosis. Through embolism, arterial maximum wall shear stress is more sensitive to stenosis severity than the embolus size whereas role of embolus size is more significant than the effect of stenosis severity on spatial and temporal gradients of wall shear stress downstream of the stenosis and on probability of clot lysis due to clot stresses while passing through the stenosis.     

A mathematical simulation of the ureter: effects of the model parameters on ureteral pressure/flow relations

Ureteral peristaltic mechanism facilitates urine transport from the kidney to the bladder. Numerical analysis of the peristaltic flow in the ureter aims to further our understanding of the reflux phenomenon and other ureteral abnormalities. Fluid-structure interaction (FSI) plays an important role in accuracy of this approach and the arbitrary Lagrangian-Eulerian (ALE) formulation is a strong method to analyze the coupled fluid-structure interaction between the compliant wall and the surrounding fluid. This formulation, however, was not used in previous studies of peristalsis in living organisms. In the present investigation, a numerical simulation is introduced and solved through ALE formulation to perform the ureteral flow and stress analysis. The incompressible Navier-Stokes equations are used as the governing equations for the fluid, and a linear elastic model is utilized for the compliant wall. The wall stimulation is modeled by nonlinear contact analysis using a rigid contact surface since an appropriate model for simulation of ureteral peristalsis needs to contain cell-to-cell wall stimulation. In contrast to previous studies, the wall displacements are not predetermined in the presented model of this finite-length compliant tube, neither the peristalsis needs to be periodic. Moreover, the temporal changes of ureteral wall intraluminal shear stress during peristalsis are included in our study. Iterative computing of two-way coupling is used to solve the governing equations. Two phases of nonperistaltic and peristaltic transport of urine in the ureter are discussed. Results are obtained following an analysis of the effects of the ureteral wall compliance, the pressure difference between the ureteral inlet and outlet, the maximum height of the contraction wave, the contraction wave velocity, and the number of contraction waves on the ureteral outlet flow. The results indicate that the proximal part of the ureter is prone to a higher shear stress during peristalsis compared with its middle and distal parts. It is also shown that the peristalsis is more efficient as the maximum height of the contraction wave increases. Finally, it is concluded that improper function of ureteropelvic junction results in the passage of part of urine back flow even in the case of slow start-up of the peristaltic contraction wave.     

Repeats and subrepeats in the intergenic spacer of rDNA from the nematode Meloidogyne arenaria

Summary Ribosomal DNA (rDNA) repeats of the plant-parasitic nematode Meloidogyne arenaria are heterogeneous in size and appear to contain 5S rRNA gene sequences. Moreover, in a recA ⁺ bacterial host, plasmid clones of a 9 kb rDNA repeat show deletion events within a 2 kb intergenic spacer (IGS), between 28S and 5S DNA sequences. These deletions appear to result from a reduction in the number of tandem 129 by repeats in the IGS. The loss of such repeats might explain how rDNA length heterogeneity, observed in the Meloidogyne genome, could have arisen. Each 129 by repeat also contains three copies of an 8 by subrepeat, which has sequence similarity to an element found in the IGS repeats of some plant rDNAs.     

Twelve year experience of laparoscopic gastric plication in morbid obesity: development of the technique and patient outcomes

ABSTRACT: BACKGROUND: Laparoscopic Gastric Plication (LGP) is a new restrictive bariatric surgery, previously introduced by the author. The aim of this study is to explain the modifications and to present the 12-year experience, regarding early and long term results, complications and cost. METHODS: We used LGP for morbid obesity during the past 12 years. Anterior plication (10 cases), one-row bilateral plication while right gastroepiploic artery included (42 cases), and excluded from the plication (104 cases) and two-row plication (644 cases). The gastric greater curvature was plicated using 2/0 prolen from fundus at the level of diaphragm preserving the His angle to just proximal to the pylorus. The anatomic and functional volume of stomach was 50cc and 25cc respectively in two-row method. Ordered postop visits also included evaluation of weight loss, complications, change of diet and control of exercise. RESULTS: LGP was performed in 800 cases (mean age: 27.5, range: 12 to 65 years, nine under 18). Female to male ratio was 81% to 19% and average BMI was 42.1 (35-59). The mean excess weight loss (EWL) was 70% (40% to 100%) after 24 months and 55% (28% to 100%) after 5 years following surgery. 134 cases (16.7%) did not completed long term follow-up. The average time of follow up was 5 years (1 month to 12 years). 5.5% and 31% of cases complained from weight regain respectively during 4 and 12 years after LGP. The mean time of operation was 72 (49--152) minutes and average hospitalization time was 72 hours (24 hours to 45 days). The cost of operation was 2000 $ less than gastric banding or sleeve and 2500 $ less than gastric bypass. Eight patients out of 800 cases (1%) required reoperation due to complications like: micro perforation, obstruction and vomiting following adhesion of His angle. Other complications included hepatitis pneumonia, self-limiting intra-abdominal bleeding and hypocalcaemia. CONCLUSION: The percentage of EWL in this technique is comparable to other restrictive methods. The technique is safe with 1.6% complication (1% reoperated), and 31% regain during 12 years. The cost of operation is less than the other methods.     

Non-plasma bonding of PDMS for inexpensive fabrication of microfluidic devices

In this video, we demonstrate how to use the neuron microfluidic device without plasma bonding. In some cases it may be desirable to reversibly bond devices to the Corning No. 1 cover glass. This could be due, perhaps, to a plasma cleaner not being available. In other instances, it may be desirable to remove the device from the glass after the culturing of neurons for certain types of microscopy or for immunostaining, though it is not necessary to remove the device for immunostaining since the neurons can be stained in the device. Some researchers, however, still prefer to remove the device. In this case, reversible bonding of the device to the cover glass makes that possible. There are some disadvantages to non-plasma bonding of the devices in that not as tight of a seal is formed. In some cases axons may grow under the grooves rather than through them. Also, because the glass and PDMS are hydrophobic, liquids do not readily enter the device making it necessary at times to force media and other reagents into the device. Liquids will enter the device via capillary action, but it takes significantly longer as compared to devices that have been plasma bonded. The plasma cleaner creates temporary hydrophilic charges on the glass and device that facilitate the flow of liquids through the device after bonding within seconds. For non-plasma bound devices, liquid flow through the devices takes several minutes. It is also important to note that the devices to be used with non-plasma bonding need to be sterilized first, whereas plasma treated devices do not need to be sterilized prior to use because the plasma cleaner will sterilize them.     

Unbiased identification of cysteine S-nitrosylation sites on proteins

Covalent addition of nitric oxide (NO) to Cys-sulfur in proteins, or S-nitrosylation, plays pervasive roles in the physiological and pathophysiological modulation of mammalian protein functions. Knowledge of the specific protein Cys residues that undergo NO addition in different biological settings is fundamental to understanding NO-mediated signal transduction. Here, we describe in detail an MS-based proteomic protocol for facile, high-throughput and unbiased discovery of SNO-Cys residues in proteins from complex biological samples. The approach, termed SNOSID (SNO-Cys site identification), can be used to identify endogenous and chemically induced S-nitrosylation sites in proteins from tissues or cells. Identified SNO-Cys sites may provide insights into novel mechanisms and proteins that mediate NO bioactivities in health and disease. SNOSID builds on the biotin-switch method for covalent addition of disulfide-linked biotin at S-nitrosylation sites on proteins. Biotinylated proteins are then subjected to trypsinolysis and the resulting biotin-tagged peptides are affinity-captured on streptavidin-agarose. After selective elution with beta-mercaptoethanol, the peptides are sequenced using nanoflow liquid chromatography tandem mass spectrometry (nLC-MS/MS). Validation that identified peptide ions as originating from authentic NO-Cys-containing precursor proteins can be provided by establishing that these peptide ions are absent from control samples where S-NO bonds were subjected to prior photolysis, using a UV transilluminator. The protocol requires approximately 2 days for sample processing, including the incubation time for proteolysis. An additional 1-2 days is needed for sample analysis by nLC-MS/MS and data analysis/interpretation.     

Cytokine gene polymorphisms involved in chronicity and complications of anterior uveitis

The aim of this study was to identify key cytokine polymorphisms associated with disease susceptibility, clinical phenotype, and outcome in patients with chronic anterior uveitis (CAU) as compared to those with recurrent self-limiting anterior uveitis (RAU). One hundred fifty seven British Caucasian patients with anterior uveitis were identified and divided into those where the inflammatory process lasted less than 3 months (RAU=118) and those where the inflammation persisted longer than 3 months (CAU=39). Patients with CAU were further sub-divided into idiopathic CAU, CAU associated with systemic disease, CAU with and without complications (posterior synechiae, posterior subcapsular lens opacity, raised intraocular pressure, cystoid macular oedema, and poor response to treatment). Sixty-six healthy controls were ethnically matched. TaqMan PCR amplification was used to genotype five single nucleotide polymorphisms in cytokine genes; IL-1RN+2018, IL-6-174, IL-10-1082, TNF-238, TNF-308 and these were correlated with clinical phenotype.