Multipronged heat-exchanger based on femtosecond laser-nano/microstructured Aluminum for thermoelectric heat scavengers.

Femtosecond (fs) laser processing can significantly alter the optical, thermal, mechanical, and electrical properties of materials. Here, we show that fs-laser processing transforms aluminum (Al) to a highly efficient and multipronged heat exchanger. By optimizing the formed surface nano- and microstructures, we increase the Al emissivity and surface area by 700% and 300%, respectively. Accordingly, we show that fs-laser treated Al (fs-Al) increases the radiative and convective cooling power of fs-Al by 2100% and 300%, respectively, at 200 °C. As a direct application, we use fs-Al as a heat sink for a thermoelectric generator (TEG) and demonstrate a 280% increase in the TEG output power compared to a TEG with an untreated Al heat exchanger at 200 °C. The multipronged enhancement in fs-Al heat exchange properties lead to an increase in the TEG output power over a wide temperature ( T ) range ( T > 50 °C ). Conversely, a simple radiative cooling heat exchanger increases the TEG output power within a limited temperature range ( T > 150 °C ) . We investigate the laser processing parameters necessary to maximize the spectral emissivity and surface area of fs-Al. Fs-Al promises to be a widely used and compact heat exchanger for passive cooling of computers and data centers as well as to increase the efficiency of TEGs incorporated in sensors and handheld electronics.

Pulse Duration and Wavelength Effects of Laser Ablation on the Oxidation, Hydrolysis, and Aging of Aluminum Nanoparticles in Water.

We analyzed the formation of the aluminum (Al) nanoparticles (NPs) with triangular shape obtained by ablating Al bulk in liquid using pulses with different durations (5 ns, 200 ps, and 30 fs) and wavelengths (355 nm, 800 nm, and 1064 nm). We report three stages of synthesis and aging of Al NPs: Formation, transformation, and stable stage. The NPs prepared by different pulses are almost identical at the initial stage. The effects of duration and wavelength of the ablation pulses on the aging of NPs are revealed. Pulse duration is determined to be essential for morphological transformation of NPs, while pulse wavelength strongly influences particle sizes. NPs produced by ultra-short pulses have smaller sizes and narrow size distribution. We demonstrate that oxidation and hydrolysis of Al in water are the results of ablation for all pulse durations and wavelengths, which also strongly modify the preferable reaction path of NPs in water, thus affecting the composition and morphology of triangle NPs. The results of modeling of the NPs generation in water due to a 50 ps laser pulse interacting with a thick Al target are presented. Water-based effects in the formation of NPs, their evolution, and solidification are considered from the mechanical and thermophysical points of view. The detailed analysis of the modeling results allowed for determination of the main mechanism responsible for the ablation process followed by the NPs formation.

How To Obtain Six Different Superwettabilities on a Same Microstructured Pattern: Relationship between Various Superwettabilities in Different Solid/Liquid/Gas Systems.

A range of different superwettabilities were obtained on femtosecond laser-structured Al surfaces. The formation mechanism of each superwetting state is discussed in this paper. It is revealed that the underwater oil droplet and bubble wettabilities of a solid surface have a close relationship with its water wettability. The laser-induced hierarchical microstructures showed superhydrophilicity in air but showed superoleophobicity/superaerophobicity after immersion in water. When such microstructures were further modified with a low-surface-energy monolayer, the wettability of the resultant surface would turn to superhydrophobicity with ultralow water adhesion in air and superoleophilicity/superaerophilicity in water. The understanding of the relationship among the above-mentioned six different superwettabilities is highly important in the design of various superwetting microstructures, transforming the structures from one superwetting state to another state and better using the artificial superwetting materials.

The shikimate pathway enzyme that generates chorismate is not required for the development of Plasmodium berghei in the mammalian host nor the mosquito vector.

In Plasmodium, the shikimate pathway is a potential target for malaria chemotherapy owing to its absence in the mammalian host. Chorismate, the end product of this pathway, serves as a precursor for aromatic amino acids, Para-aminobenzoic acid and ubiquinone, and is synthesised by Chorismate synthase (CS). Therefore, it follows that the Cs locus may be refractory to genetic manipulation. By utilising a conditional mutagenesis system of yeast Flp/FRT, we demonstrate an unexpectedly dispensable role of CS in Plasmodium. Our studies reiterate the need to establish an obligate reliance on Plasmodium metabolic enzymes through genetic approaches before their selection as drug targets.

A promising anticancer and antimalarial component from the leaves of Bidens pilosa.

Bidens pilosa is used in folk medicine for various applications due to the presence of polyacetylenes, flavonoids, terpenoids, phenylpropanoids and others. Bioactivity-guided fractionation of different extracts of B. pilosa leaf showed potential in vitro anticancer and antimalarial activity and led to the identification of a potential marker compound, phenyl-1,3,5-heptatriyne. Erythrocyte osmotic fragility experiments revealed the various extracts as well as the marker component's toxicity profiles on normal blood cells.

A malaria vaccine that elicits in humans antibodies able to kill Plasmodium falciparum.

BACKGROUND: Plasmodium falciparum merozoite surface protein 3 is a malaria vaccine candidate that was identified, characterised, and developed based on a unique immuno-clinical approach. The vaccine construct was derived from regions fully conserved among various strains and containing B cell epitopes targeted by human antibodies (from malaria-immune adults) that are able to mediate a monocyte-dependent parasite killing effect. The corresponding long synthetic peptide was administered to 36 volunteers, with either alum or Montanide ISA720 as adjuvant. METHODS AND FINDINGS: Both formulations induced cellular and humoral immune responses. With alum, the responses lasted up to 12 mo. The vaccine-induced antibodies were predominantly of cytophilic classes, i.e., able to cooperate with effector cells. In vitro, the antibodies induced an inhibition of the P. falciparum erythrocytic growth in a monocyte-dependent manner, which was in most instances as high as or greater than that induced by natural antibodies from immune African adults. In vivo transfer of the volunteers' sera into P. falciparum-infected humanized SCID mice profoundly reduced or abrogated parasitaemia. These inhibitory effects were related to the antibody reactivity with the parasite native protein, which was seen in 60% of the volunteers, and remained in samples taken 12 mo postimmunisation. CONCLUSION: This is the first malaria vaccine clinical trial to clearly demonstrate antiparasitic activity by vaccine-induced antibodies by both in vitro and in vivo methods. The results, showing the induction of long-lasting antibodies directed to a fully conserved polypeptide, also challenge current concepts about malaria vaccines, such as unavoidable polymorphism, low antigenicity, and poor induction of immune memory.

Chronomics: circadian and circaseptan timing of radiotherapy, drugs, calories, perhaps nutriceuticals and beyond.

We suggest a putative benefit from timing nutriceuticals (substances that are both nutrients and pharmaceuticals) such as antioxidants for preventive or curative health care, based on the proven merits of timing nutrients, drugs, and other treatments, as documented, i.a., in India. The necessity of timing melatonin, a major antioxidant, is noted. A protocol to extend the scope of chronoradiotherapy awaits testing. Imaging in time by mapping rhythms and broader time structures, chronomes, for earliest diagnoses, for example detection of vascular disease risk, is recommended. The study of rhythms and broader chronomes leads to a dynamic functional genomics, guided by imaging in time of free radicals and antioxidants, amongst many other variables.