Feasibility test of a sapphire cryoprobe with optical monitoring of tissue freezing

This article describes a sapphire cryoprobe as a promising solution to the significant problem of modern cryosurgery that is the monitoring of tissue freezing. This probe consists of a sapphire rod manufactured by the edge-defined film-fed growth technique from Al₂O₃ melt and optical fibers accommodated inside the rod and connected to the source and the detector. The probe's design enables detection of spatially resolved diffuse reflected intensities of tissue optical response, which are used for the estimation of tissue freezing depth. The current type of the 12.5-mm diameter sapphire probe cooled down by the liquid nitrogen assumes a superficial cryoablation. The experimental test made by using a gelatin-intralipid tissue phantom shows the feasibility of such concept, revealing the capabilities of monitoring the freezing depth up to 10 mm by the particular instrumentation realization of the probe. This justifies a potential of sapphire-based instruments aided by optical diagnosis in modern cryosurgery.     

In vivo detection of human cutaneous beta‐carotene using computational optical clearing

The content of dermal beta‐carotene can be a good indicator showing the body health. Because, it is involved in production of vitamin A maintaining healthy skin and mucous membranes. Also, it reduces the risk of cardiovascular diseases and its antioxidant capacity prevents the formation of cancerous cells. In this work, we use Raman spectroscopy and a low‐cost diffuse reflectance spectroscopy (DRS) to detect the dermal beta‐carotene spectra. We apply computational optical clearing (OC) method to in vivo evaluation the concentration of this chromophore. The results show that Raman spectroscopy is a good tool for in vitro detection of carotenoids but is not able to clearly discriminate the individual carotenoids in skin tissue in vivo. The results also show that using OC enhances the ability of low‐cost diffuse reflection spectroscopy for in vivo detection of dermal beta‐carotene in humans. This method can be used as a low‐cost and portable device to screening the concentration of chromophores such as melanin and carotenoid molecules for oncological studies.     

NIR spectroscopic imaging to map hemoglobin + myoglobin oxygenation,their concentration and optical pathlength across a beating pig heart during surgery

The purpose of this paper is to demonstrate that near‐infrared (NIR) spectroscopic imaging can provide spatial distribution (maps) of the absolute concentration of hemoglobin + myoglobin, oxygen saturation parameter and optical pathlength, reporting on the biochemico‐physiological status of a beating heart in vivo. The method is based on processing the NIR spectroscopic images employing a first‐derivative approach. Blood‐pressure‐controlled gating compensated the effect of heart motion on the imaging. All the maps are available simultaneously and noninvasively at a spatial resolution in the submillimeter range and can be obtained in a couple of minutes. The equipment has no mechanical contact with the tissue, thereby leaving the heart unaffected during the measurement. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Broadband spectral verification of optical clearing reversibility in lung tissue

The increase of tissue transparency through sequential optical immersion clearing treatments and treatment reversibility have high interest for clinical applications. To evaluate the clearing reversibility in a broad spectral range and the magnitude of the transparency created by a second treatment, the present study consisted on measuring the spectral collimated transmittance of lung tissues during a sequence of two treatments with electronic cigarette (e-cig) fluid, which was intercalated with an immersion in saline. The saline immersion clearly reverted the clearing effect in the lung tissue in the spectral range between 220 and 1000 nm. By a later application of a second treatment with the e-cig fluid, the magnitude of the optical clearing effect was observed to be about the double as the one observed in the first treatment, showing that the molecules of the optical clearing agent might have converted some bound water into mobile water during the first treatment.     

Genetically isolated sympatric forms of threespine stickleback,Gasterosteus aculeatus,in Lake Azabachije (Kamchatka-peninsula,USSR)

Synopsis Two sympatric morphs of threespine stickleback Gasterosteus aculeatus are found in Lake Azabachije (Kamchatka, USSR); resident low-plated leiurus and completely plated trachurus, migrating from the Bering sea into the Lake to spawn. The absence of the intermediate morph semiarmatus and significant differences in a number of characters are indicative of reproductive isolation. The results show that the leiurus morph is common in the regions other than those with mild climate and small seasonal fluctuations of temperature.     

Biosorption of heavy metals from acid mine drainage onto biopolymers (chitin and α (1,3) β-D-glucan) from industrial biowaste exhausted brewer’s yeasts (Saccharomyces cerevisiae L.)

A biosorption process has been developed for the bioremediation of heavy metal-contaminated acid drainages from Merladet and Faith open-cast mines, located in western Spain. The process is based on the physico-chemical properties for the adsorption, ion exchange, and complexation of metal ions by biopolymers (chitin and α (1,3) β-D-glucan) from industrial biowaste exhausted brewer’s yeast (Saccharomyces cerevisiae L.). Firstly, the chemical composition (U, Mn, Al, Fe, Cu, Zn, and Ni) and the physico-chemical and ecological states of these acid mine drainages were characterised. Furthermore, the selectivity for Zn, Cu, Mn, Ni, and Al the first order kinetics and the performance of the metals biosorption process by exhausted brewer’s yeast were evaluated with polluted acid synthetic waters and mine drainages. The biosorption equilibria were reached in 10 ∼ 15 min following Langmuir type isotherms with higher affinity constants for metal-biosorbent binding for synthetic waters than for acid mine drainages. The efficiency of the process with real water samples was markedly lower for the case of Mn, and zero for Zn and Al. An antagonistic interference on the biosorption of a metal due to the presence of other metals is proposed. Finally, the ecotoxicity of the acid mine drainage was removed when it was incubated with brewer’s yeast trapped in polyurethane foam.     

Synthesis of (5Z,8Z,11Z,14Z)-18- and 19-azidoeicosa-5,8,11,14-tetraenoic acids and their [5,6,8,9,11,12,14,15-H8]-analogues through a common synthetic route

Total synthesis of (5Z,8Z,11Z,14Z)-18- and 19-azidoeicosa-5,8,11,14-tetraenoic acids and their [5,6,8,9,11,12,14,15-³H₈]-analogues via the corresponding p-toluenesulphonates is reported. This synthetic approach allows the preparation of radioactively labelled arachidonic acid derivatives following a common synthetic route. Activity assays indicated that 15-lipoxygenases may tolerate the azido group in the substrate binding pocket and thus, radioactively labelled azido compounds may be used as photo-affinity probes to investigate mechanistic features of eicosanoid biosynthesis.     

Simple Method for Preparation of Nanostructurally Organized Spines of Sand Dollar Scaphechinus mirabilis (Agassiz, 1863)

Unique skeletal formations of marine invertebrates, including representatives of Echinodermata, have the unique potential to serve as templates for bio-inspired materials chemistry, biomimetics, and materials science. The sand dollar Scaphechinus mirabilis (Agassiz, 1983) is widely distributed in the northwest of the Pacific Ocean from southern Japan to the Aleutian Islands. This animal is the main source of naphtochinone-based substances. These compounds have recently drawn medical attention for their use as cardiological and ophthalmological drugs. Unfortunately, after extraction of the naphtochinones, the residual skeletons and spines of the sand dollars were usually discarded. Here, we report the first method for the preparation of nanostructurally organized spines of S. mirabilis, using a simple enzymatic and hydrogen peroxide-based treatment. Application of this method opens the way for development of non-wasteful environmentally clean technology of sand dollars as well-known industrial marine invertebrates.     

Interaction of spermine with different forms of DNA. A conformational study

The energy of interaction of a spermine molecule with the A - and B -forms of DNA has been calculated, assuming that the molecule of spermine is fixed in the narrow groove of the DNA helix with the formation of hydrogen bonds between the amino groups of spermine and the phosphate groups of DNA. The atom–atom potentials method was used. Optimal structures for the A-DNA–spermine and B-DNA–spermine complexes are suggested. It is shown that, in agreement with the experimental data, the interaction of the spermine molecule with the A -DNA is energetically more favorable than that with the B -DNA. Two main factors are responsible for this: (1) the distance between neighboring phosphates of the chain in A -DNA (which is about 1 Å less than that in B -DNA) corresponds better to the distance between the amino groups of the propyl part of spermine; and (2) the orientation of phosphate groups in A -DNA inside the groove is preferable for complex formation with spermine to the outside groove arrangement of the phosphates in B -DNA. These conclusions are further confirmed by the calculations for DNA–propane diamine complexes.