9 research outputs found
Enhancement of mechanical and tribological properties of SiC- and CB-reinforced aluminium 7075 hybrid composites through friction stir processing
<p>Aluminium alloy has wide application in both aircraft and automobile industry due to its high strength and light weight benefits. In this research work, stir casting process was used for fabricating aluminium alloy 7075 reinforced by silicon carbide (SiC) and carbon black (CB) particulates. X-ray diffraction analysis, energy dispersive X-Rays analysis and field emission scanning electron microscopy (FE-SEM) confirmed the presence of SiC and CB particles and there uniform distribution in aluminium matrix. Further, as-cast composites have been processed by friction stir processing (FSP) technique with the appropriate processing parameter: tool speed, feed rate and tool tilt angle. Mechanical and microstructural properties of the composites before and after FSP were investigated through universal testing machine and optical microscopy. The novel feature of as-cast AA7075/SiC/CB is that it demonstrates a 2.5 times increment in the ultimate tensile strength and at the same time, significant amount of increased ductility. Ductile failure may be possible fracture mechanism as shown in FE-SEM analysis. Further, the tribological behaviour of the synthesized composites studied under dry sliding conditions before and after FSP and the results indicates significant improvement in wearing capacity of the composites. Also, weight loss of the various composites by varying three input variable process parameters were investigated followed by analysis of variance and regression analysis. The presence of 5 wt.% SiC and 5 wt.% CB in the composites can exhibit superior mechanical as well as wear property as compared to base alloy.</p
MOESM2 of Lactococcus lactis provides an efficient platform for production of disulfide-rich recombinant proteins from Plasmodium falciparum
Additional file 2. Successful expression of different P. falciparum antigen derived recombinant proteins in L. lactis. Purity profile of different target recombinant proteins as determined by SDS-PAGE analysis as shown by Coomassie blue staining (top panel) or Western Blot analysis (bottom panel) observed with anti-His antibody
MOESM3 of Lactococcus lactis provides an efficient platform for production of disulfide-rich recombinant proteins from Plasmodium falciparum
Additional file 3. Anomalous migration by SDS-PAGE is related to protein disorder. Anomalous mobility was determined as the ratio between the apparent molecular weight as determined by SDS-PAGE and the molecular weight calculated from the deduced amino acid sequence (Table 1). Protein disorder was predicted using the IUPred software [41]. The protein disorder score was estimated by calculating the percentage of residues with a disorder score above 0.7
MOESM1 of Lactococcus lactis provides an efficient platform for production of disulfide-rich recombinant proteins from Plasmodium falciparum
Additional file 1. Success rate of obtaining expression of target recombinant protein in L. lactis is not dependent on its biophysical characteristics. Success rate of expression of different target recombinant proteins in L. lactis have been grouped into High, Medium or Low depending on the yield of the respective expression. Yields show poor co-relations with the protein disorder score and presence of cysteine residues (a) and iso-electric point and the predicted molecular weight of the target recombinant proteins (b)
In Vitro Antiparasitic Effect of the Volunteers' Antibodies in ADCI Assay
<p>Shown are results obtained with volunteers' serum samples collected either at month 5 (A) or at month 12 (B), as compared to the African immune IgG pool able to transfer clinical protection in humans (dark bars, pool of immune African globulin-positive control). Each bar represents the mean value obtained with each volunteer serum, in three separate experiments ± SD. The results from WB assays (performed with months 5 and 12 samples side by side with a positive control) are shown below those of the ADCI assay for each individual volunteer and are expressed as either negative (−) or positive (+ or ++). For each group, the increasing grey colour corresponds to increasing immunisation doses, e.g., from left to right, Montanide (unhatched bars) 10–10–10, 20–20–20, 30–30–10, and 100–10–10, and for alum (hatched bars) 30–30–30 and 100–10–10. SGI values 30% or greater are considered positive. Dotted line indicates the threshold of positivity of the ADCI assay.</p
Mean Biological Effect of Antibodies in Either Direct or Monocyte-Dependent Fashion, at Various Time Points with Each Adjuvant
<p>Shown are the means ± standard error of the mean of the effects of sera from all volunteers in direct growth inhibition assays (used as a control in each ADCI assay; see Methods) and in monocyte-dependent ADCI assays (sera from 30 volunteers were analyzed at each time point, i.e., the figure summarizes results from 90 sera). Triangles, Montanide-adjuvated vaccine; circles, alum-adjuvated vaccine. Open symbols, direct growth inhibition by antibodies; solid symbols, monocyte-dependent ADCI assays. Months 0, 5, and 12: sera collected before immunisation, 1 mo after the last immunisation, and 12 mo after the first immunisation, respectively.</p
In Vivo Passive Transfer of the Volunteers' Antibodies in <i>P. falciparum–</i>Infected Humanised Mice
<div><p>Shown are representative examples of results obtained by passive transfer of Western Blot positive sera collected at month 5 (A), or of control sera (B), and of WB-positive sera collected at month 12 (C).</p>
<p>(A) <i>P. falciparum</i> infected SCID mice received 200 μl of sera delivered IP from three WB-positive volunteers, collected at month 5, 1 mo after the last immunisation. Shown are results from two mice that received, first, normal monocytes (MN), then monocytes with preimmunisation control sera (month 0), followed by month 5 sera with monocytes (solid arrows corresponding to volunteers 14 and 16, open and solid squares, respectively), one mouse receiving first monocytes followed by monocytes with month 5 serum (dotted arrows, dotted line, open circles)</p>
<p>(B) <i>P. falciparum–</i>infected SCID mice received 200 μl of sera from controls. Either monocytes followed by monocytes with serum from a WB-negative volunteer (dotted arrows, dotted line, open circles), or monocytes with preimmunisation samples from two volunteers followed by serum alone, repeated twice (plain arrows, solid and open squares).</p>
<p>(C) <i>P. falciparum–</i>infected SCID mice received 200 μl of sera from three WB-positive volunteers, collected at month 12. All animals received monocytes first, followed by monocytes with the 12-mo serum, followed by serum alone. Reproducibility is shown in two animals receiving the serum from a single donor (volunteer 21, solid squares and open circles). Transfer of serum alone was ineffective (solid squares, days 6 and 7) indicating that the strong in vivo antiparasitic effect depends on monocyte-antibody cooperation.</p></div
Immunogenicity of the MSP3-LSP in Volunteers Receiving the Vaccine Adjuvated by Montanide or Alum
<div><p>(A) Scheme of immunisation (arrows) and of sampling (plain circles). Samples for immunoassays were taken 1 mo after each immunisation.</p>
<p>(B) Lymphoproliferative responses (bars) and IFN-γ secretion (*), ± SD, as compared to controls. PHA, phytohemagglutinin; TT, tetanus toxoid. IFN-γ values for TT and PHA are those obtained using month 5 samples.</p>
<p>(C) Mean ELISA IgG titres to the MSP3-LSP at various time points during and after immunisation (months 1, 5, and 12 after the first immunisation).</p>
<p>(D) Proportion of WB-positive individuals in each group at different time points ± 95% confidence intervals.</p>
<p>(E) Isotype distribution of antibodies measured in ELISA with IgG subclass-specific secondary antibodies (data from samples collected at month 5).</p>
<p>In each graph, the increasing grey colour corresponds to increasing immunisation doses, e.g., for Montanide (unhatched bars) from left to right, 10–10–10, 20–20–20, 30–30–10, 100–10–10, and for alum (hatched bars) 30–30–30 and 100–10–10.</p></div
Amalgamation of Synthetic Biology and Chemistry for High-Throughput Nonconventional Synthesis of the Antimalarial Drug Artemisinin
The development of
a cost-effective process for the production
of artemisinin, the precursor of all artemisinin-derived drugs, the
first-line treatment for malaria, has been a long-pursued endeavor.
The breakthrough achievement of coaxing genetically engineered yeast
to express Artemisia annua genes for
the commercial production of artemisinic acid, an advanced intermediate
in the synthesis of artemisinin, has yet to fully realize an affordable
malaria treatment for the poor because of the lack of a cost-effective
chemical conversion into artemisinin. We describe herein a commercially
feasible and pragmatic synthesis of artemisinin from amorpha-4,11-diene,
an early-stage intermediate produced in 2-fold higher molar yield
than engineered yeast cells can process into artemisinic acid. The
key to this novel approach is an exceedingly effective functionalization
of the isopropenyl group of amorphadiene via <i>endo</i>-epoxyamorphadiene to give dihydroartemisinic acid, which upon esterification
followed by oxidation and cyclicization furnishes pure artemisinin
in approximately 60% yield