Comparative analysis of web applications implemented in: PHP and Python

This article presents a comparative analysis of two web applications implemented in PHP and Python. Test applications were created and equipped with the same functionality used in tests consisting in measuring the server response times to INSERT, SELECT, UPDATE and DELETE requests - handling database operations. The purpose of the research was to compare both languages in terms of selected criteria. Their performance, source code volume and popularity were compared

Fractionation of human red blood cells based on intrinsic magnetization

Red blood cell (RBC) transfusion is clinically used to treat hemodynamic instability and O2 carrying deficits in patients with acute blood loss, and patients with chronic anemia caused by bone marrow failure/suppression. Currently, cold storage of human RBCs (hRBCs) can preserve hRBCs for a maximum of six weeks (i.e. 42 days), set by the United States Food and Drug Administration (US FDA). However, as stored RBCs age, they undergo biochemical and biophysical changes that are often referred to as the storage lesion, which decreases the efficacy of transfusion while increasing the risk for transfusion-associated adverse effects. It is well known that upon transfusion of stored RBCs, there is a population of RBCs (i.e. healthy RBCs) that circulate for more than 24 hours, and another smaller population (i.e. damaged RBCs) that are cleared within 24 hours post transfusion. This population of cells destined to be cleared quickly can be higher than 25% in units stored for a mean of 30 days. The objective of our current project is to remove aged RBCs based on hemoglobin content. Under the influence of ultra-high magnetic fields and gradients, we have demonstrated that it is possible to fractionate RBCs into multiple factions based solely on difference in the intrinsic magnetization of the deoxygenated form of hemoglobin inside the RBCs (i.e. labeless separation). We hypothesize for our currently funded National Institute of Heart Lung and Blood project that healthy RBCs with higher Hb content correlate with longer half lives in transfused animal models than unhealthy RBCs which have lost some of their hemoglobin. In addition, material balances are being performed to track the hemoglobin molecules that are lost during the extended periods of storage. This work will reveal the mechanism behind the lost hemoglobin during RBC storage, deepen the knowledge about aged RBCs and RBC-associated exosomes, and facilitate bulk separation of RBCs without labeling the cells. Therefore, it could be clinically beneficial if the damaged RBCs in any unit of RBCs could be separated leaving a population of only healthy RBCs behind for transfusion. When a recipient is transfused with a dose of RBCs that overwhelms their circulatory system’s ability to compensate for the increased intravascular volume, heart failure can ensue. This condition is known as Transfusion Associated Circulatory Overload (TACO). It is the second leading cause of death related to transfusion reported to the FDA

LEAVES: Lofted Environmental and Atmospheric Venus Sensors

LEAVES (Lofted Environmental Atmospheric Venus Sensors) is a design exercise with the goal of dramatically decreasing the cost of obtaining prioritized chemical and physical data in planetary atmospheres. Through the application of a swarm approach this concept parallelizes atmospheric exploration, with geographic coverage far exceeding what is possible with conventional monolithic platforms or sondes. Each unit in the swarm is exceptionally compact, with a powered payload mass of only a few tens of grams and a high-drag, semi-rigid structure that acts to slow each probe as it descends through the atmosphere. This structural design can collapse into a planar form to allow for efficient stowage prior to arrival at the target body. With a total per-unit mass of only 120 g, a fleet of 100 (or more) units can be very reasonably accommodated on a carrier spacecraft.Science operations, which begin when the LEAVES probes reach an altitude of 100 km, are targeted for the cloud-bearing region of Venus' atmosphere. During the roughly 9 hour, terminal velocity descent through the atmosphere, LEAVES collects data of the state and composition of the atmosphere in parallel across multiple units. These data would represent an unprecedented constraint on the distribution and concentration of targeted chemical species, and the detection of local and regional variations in both chemistry and physical properties.A novel and compelling result of this exercise was that the same optimization that produced a structure with an exceptionally low areal mass density (0.126 kg/m2) also resulted in a probe that can be deployed directly from an aerobraking orbit (~140 km at 5 km/s) without the need for aeroshell protection. This translates to a tremendous mass savings and gives LEAVES the flexibility to be carried as a secondary payload aboard either a descending surface probe or an orbital radar mapper. Because such missions are under active development or have already been proposed (but not flown), we infer that LEAVES is well positioned as a technolog

Erythrocyte enrichment in hematopoietic progenitor cell cultures based on magnetic susceptibility of the hemoglobin

Using novel media formulations, it has been demonstrated that human placenta and umbilical cord blood-derived CD34+ cells can be expanded and differentiated into erythroid cells with high efficiency. However, obtaining mature and functional erythrocytes from the immature cell cultures with high purity and in an efficient manner remains a significant challenge. A distinguishing feature of a reticulocyte and maturing erythrocyte is the increasing concentration of hemoglobin and decreasing cell volume that results in increased cell magnetophoretic mobility (MM) when exposed to high magnetic fields and gradients, under anoxic conditions. Taking advantage of these initial observations, we studied a noninvasive (label-free) magnetic separation and analysis process to enrich and identify cultured functional erythrocytes. In addition to the magnetic cell separation and cell motion analysis in the magnetic field, the cell cultures were characterized for cell sedimentation rate, cell volume distributions using differential interference microscopy, immunophenotyping (glycophorin A), hemoglobin concentration and shear-induced deformability (elongation index, EI, by ektacytometry) to test for mature erythrocyte attributes. A commercial, packed column high-gradient magnetic separator (HGMS) was used for magnetic separation. The magnetically enriched fraction comprised 80% of the maturing cells (predominantly reticulocytes) that showed near 70% overlap of EI with the reference cord blood-derived RBC and over 50% overlap with the adult donor RBCs. The results demonstrate feasibility of label-free magnetic enrichment of erythrocyte fraction of CD34+ progenitor-derived cultures based on the presence of paramagnetic hemoglobin in the maturing erythrocytes. © 2012 Jin et al

Recovery of magnetic catalysts: advanced design for process intensification

The design of microdevices in which components with magnetic character must be separated and recovered from reactive media benefits from the advantages of microfluidics and meets the criteria for process intensification; however, there are open questions, such as the design of the most appropriate magnet arrangement, that need further research in order to increase the magnetic gradient exerted on the particles. Herein, we focus on the continuous recovery of magnetic microparticles, that can be used as support to facilitate the recovery of biocatalysts (magnetic microcatalysts, MMCs) from biological fluids. We analyze and compare the performance of two typical magnetophoretic microdevices for addressing bead recovery: (i) annular channels with a quadrupole orientation of the permanent magnets (quadrupole magnetic sorter, QMS) and (ii) the standard design, which consists of rectangular channels with a single permanent magnet to generate the magnetic field. To this end, an experimentally validated computational fluid dynamics (CFD) numerical model has been employed. Our results reveal that for devices with the same width and length, the micro QMS, in comparison to a rectangular channel, could accomplish the complete particle retrieval while (i) processing more than 4 times higher fluid velocities, treating more than 360 times higher flow rates or (ii) working with smaller particles, thus reducing by 55% the particle mass. Additionally, the parallel performance of +/-300 micro-QMSs fulfills the processing of flow rates as high as 200 L·h-1 while entirely capturing the magnetic beads. Thereby, this work shows the potential of the QMS advanced design in the intensification of the recovery of catalysts supports of magnetic character.Financial support from the Spanish Ministry of Science, Innovation and Universities under the project RTI2018- 093310-B-I00 is gratefully acknowledged. Cristina González-Fernández acknowledges the FPU (FPU18/03525) postgraduate research grants. We also wish to thank the United States National Institutes of Health (1R01HL131720-01A1, CA62349) and the United States Defense Advanced Research Projects Agency (BAA07-21) for financial assistance

Enhanced detection of gametocytes by magnetic deposition microscopy predicts higher potential for Plasmodium falciparum transmission

<p>Abstract</p> <p>Background</p> <p>Aggregated haemozoin crystals within malaria-infected erythrocytes confer susceptibility of parasitized cells to a magnetic field. Here the utility of this method for diagnosis of human malaria is evaluated in a malaria-endemic region of Papua New Guinea (PNG).</p> <p>Methods and findings</p> <p>Individuals with <it>Plasmodium falciparum </it>malaria symptoms (n = 55) provided samples for conventional blood smear (CBS) and magnetic deposition microscopy (MDM) diagnosis. Standard Giemsa staining and light microscopy was performed to evaluate all preparations. <it>Plasmodium falciparum </it>parasitaemia observed on MDM slides was consistently higher than parasitaemia observed by (CBS) for ring (CBS = 2.6 vs. MDM = 3.4%; t-test P-value = 0.13), trophozoite (CBS = 0.5 vs. MDM = 1.6%; t-test P-value = 0.01), schizont (CBS = 0.003 vs. MDM = 0.1%; t-test P-value = 0.08) and gametocyte (CBS = 0.001 vs. MDM = 0.4%; t-test P-value = 0.0002) parasitaemias. Gametocyte prevalence determined by CBS compared to MDM increased from 7.3% to 45%, respectively.</p> <p>Conclusion</p> <p>MDM increased detection sensitivity of <it>P. falciparum</it>-infected, haemozoin-containing erythrocytes from infected humans while maintaining detection of ring-stage parasites. Gametocyte prevalence five-fold higher than observed by CBS suggests higher malaria transmission potential in PNG endemic sites compared to previous estimates.</p

Inverted Linear Halbach Array for Separation of Magnetic Nanoparticles

A linear array of Nd-Fe-B magnets has been designed and constructed in an inverted Halbach configuration for use in separating magnetic nanoparticles. The array provides a large region of relatively low magnetic field, yet high magnetic field gradient in agreement with finite element modeling calculations. The magnet assembly has been combined with a flow channel for magnetic nanoparticle suspensions, such that for an appropriate distance away from the assembly, nanoparticles of higher moment aggregate and accumulate against the channel wall, with lower moment nanoparticles flowing unaffected. The device is demonstrated for iron oxide nanoparticles with diameters of ~5 and 20 nm. In comparison to other approaches, the inverted Halbach array is more amenable to modeling and to scaling up to preparative quantities of particles

Magnetic separation of algae genetically modified for increased intracellular iron uptake

a b s t r a c t Algae were investigated in the past as a potential source of biofuel and other useful chemical derivatives. Magnetic separation of algae by iron oxide nanoparticle binding to cells has been proposed by others for dewatering of cellular mass prior to lipid extraction. We have investigated feasibility of magnetic separation based on the presence of natural iron stores in the cell, such as the ferritin in Auxenochlorella protothecoides (A. protothecoides) strains. The A. protothecoides cell constructs were tested for inserted genes and for increased intracellular iron concentration by inductively coupled plasma atomic absorption (ICP-AA). They were grown in Sueoka&apos;s modified high salt media with added vitamin B1 and increasing concentration of soluble iron compound (FeCl 3 EDTA, from 1 Â to 8 Â compared to baseline). The cell magnetic separation conditions were tested using a thin rectangular flow channel pressed against interpolar gaps of a permanent magnet forming a separation system of a well-defined fluid flow and magnetic fringing field geometry (up to 2.2 T and 1000 T/m) dubbed &quot;magnetic deposition microscopy&quot;, or MDM. The presence of magnetic cells in suspension was detected by formation of characteristic deposition bands at the edges of the magnet interpolar gaps, amenable to optical scanning and microscopic examination. The results demonstrated increasing cellular Fe uptake with increasing Fe concentration in the culture media in wild type strain and in selected genetically-modified constructs, leading to magnetic separation without magnetic particle binding. The throughput in this study is not sufficient for an economical scale harvest

A subpopulation of monocytes in normal human blood has significant magnetic susceptibility : quantification and potential implications

The presence of iron in circulating monocytes is well known as they play essential roles in iron recycling. Also, the storage of this metal as well as its incorrect uptake and/or release are important data to diagnose different pathologies. It has been demonstrated that iron storage in human blood cells can be measured through their magnetic behavior with high accuracy; however, the magnetic characteristics of monocytes have not been reported so far to the best of our knowledge. Therefore, in this work, we report, for the first time, the physical and magnetic properties of human monocytes, along with plasma platelets, oxyhemoglobin red blood cells (oxyHb‐RBCs), and methemoglobin red blood cells (metHb‐RBCs). The different cell populations were separated by Ficoll‐density gradient centrifugation, followed by a flow sorting step to isolate monocytes from peripheral blood mononuclear cells. The different fractions were analyzed by Coulter Counter (for determining the size distribution and concentration) and the sorted monocytes were qualitatively analyzed on ImageStream, a state‐of‐the‐art imaging cytometer. The analysis of the Coulter Counter and ImageStream data suggests that although there exists contamination in the monocyte fraction, the integrity of the sorted monocytes appears to be intact and the concentration was high enough to precisely measure their magnetic velocity by Cell Tracking Velocimetry. Surprisingly, monocytes reported the highest magnetic mobility from the four fractions under analysis, with an average magnetic velocity 7.8 times higher than MetHb‐RBCs, which is the only type of cells with positive magnetic velocities. This value is equivalent to a susceptibility 2.5 times higher than the value reported by fresh MetHb‐RBCs. It should be noted that this is the first study that reports that a subpopulation of human monocytes is much more magnetic than MetHb‐RBCs, opening the door to the possible isolation of human monocytes by label‐free magnetic techniques. Further, it is suggested that these magnetic monocytes could “contaminate” positively selected, immunomagnetically labeled blood cells (i.e., during a process using magnetically conjugated antibodies targeting cells, such as CD34 positive cells). Conversely, these magnetic monocytes could be inadvertently removed from a desired blood population when one is using a negative magnetic isolation technique to target cells for removal.The National Heart, Lung, and Blood Institute (1R01HL131720-01A1) and DARPA (BAA07-21).https://onlinelibrary.wiley.com/journal/155249302020-05-01hj2019BiochemistryGeneticsMicrobiology and Plant PathologyPlant Production and Soil Scienc