The Effect of Botanical Tinctures and Essential Oils on the Growth and Morphogenesis of Candida albicans

Objective: Candida albicans is an opportunistic and polymorphic fungal pathogen that affects mucosal membranes and squamous epithelia as well as being part of the normal human flora. Historically, there have been many botanical-based remedies used to treat fungal conditions, including C. albicans. This study examined the efficacy of both botanical tinctures and essential oils on the growth and morphological differentiation of C. albicans. Methods: The in vitro growth and differentiation of C. albicans was monitored following treatment with ethanol-based tinctures and essential oils prepared from several commonly used botanicals. Results: Results demonstrated that all ethanol-based botanical tinctures tested did not inhibit the growth of C. albicans, but several tinctures, including Marsdenia condurango, Juglans nigra (Black walnut), Anemopsis californica (Yerba mansa) and Piper cubeba (Cubeb berry), significantly reduced the morphological differentiation of the yeast into the invasive hyphae form. Alternatively, several botanical essential oils, including those from Thymus vulgaris (Thyme), Rosmarinus officinalis (Rosemary) and Cymbopogon citratus (Lemon grass) had a dramatic effect on inhibiting the growth of C. albicans. Conclusions: These results suggest that botanical tinctures commonly used in the treatment of C. albicans infections may act by blocking the differentiation of the yeast into a more virulent hyphal form while not affecting the growth rate. In comparison, therapeutic essential oils may target both the differentiation and growth rate of C. albicans. The results support that different active constituents are present in botanical tinctures as compared to oils thereby contributing to our understanding of how these botanicals may be effective therapeutics in the treatment of C. albicans infections

Mechanisms of Manganese-Assisted Nonradiative Recombination in Cd(Mn)Se/Zn(Mn)Se Quantum Dots

Mechanisms of nonradiative recombination of electron-hole complexes in Cd(Mn)Se/Zn(Mn)Se quantum dots accompanied by interconfigurational excitations of Mn$^{2+}$ ions are analyzed within the framework of single electron model of deep {\it 3d}-levels in semiconductors. In addition to the mechanisms caused by Coulomb and exchange interactions, which are related because of the Pauli principle, another mechanism due to {\it sp-d} mixing is considered. It is shown that the Coulomb mechanism reduces to long-range dipole-dipole energy transfer from photoexcited quantum dots to Mn$^{2+}$ ions. The recombination due to the Coulomb mechanism is allowed for any states of Mn$^{2+}$ ions and {\it e-h} complexes. In contrast, short-range exchange and ${\it sp-d}$ recombinations are subject to spin selection rules, which are the result of strong {\it lh-hh} splitting of hole states in quantum dots. Estimates show that efficiency of the {\it sp-d} mechanism can considerably exceed that of the Coulomb mechanism. The phonon-assisted recombination and processes involving upper excited states of Mn$^{2+}$ ions are studied. The increase in PL intensity of an ensemble of quantum dots in a magnetic field perpendicular to the sample growth plane observed earlier is analyzed as a possible manifestation of the spin-dependent recombination.Comment: 14 pages, 2 figure

Cell encapsulation systems toward modular tissue regeneration: from immunoisolation to multifunctional devices

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Electrophysiological Guidance of Epidural Electrode Array Implantation over the Human Lumbosacral Spinal Cord to Enable Motor Function after Chronic Paralysis.

Epidural electrical stimulation (EES) of the spinal cord has been shown to restore function after spinal cord injury (SCI). Characterization of EES-evoked motor responses has provided a basic understanding of spinal sensorimotor network activity related to EES-enabled motor activity of the lower extremities. However, the use of EES-evoked motor responses to guide EES system implantation over the spinal cord and their relation to post-operative EES-enabled function in humans with chronic paralysis attributed to SCI has yet to be described. Herein, we describe the surgical and intraoperative electrophysiological approach used, followed by initial EES-enabled results observed in 2 human subjects with motor complete paralysis who were enrolled in a clinical trial investigating the use of EES to enable motor functions after SCI. The 16-contact electrode array was initially positioned under fluoroscopic guidance. Then, EES-evoked motor responses were recorded from select leg muscles and displayed in real time to determine electrode array proximity to spinal cord regions associated with motor activity of the lower extremities. Acceptable array positioning was determined based on achievement of selective proximal or distal leg muscle activity, as well as bilateral muscle activation. Motor response latencies were not significantly different between intraoperative recordings and post-operative recordings, indicating that array positioning remained stable. Additionally, EES enabled intentional control of step-like activity in both subjects within the first 5 days of testing. These results suggest that the use of EES-evoked motor responses may guide intraoperative positioning of epidural electrodes to target spinal cord circuitry to enable motor functions after SCI

Geometric Path Integrals. A Language for Multiscale Biology and Systems Robustness

In this paper we suggest that, under suitable conditions, supervised learning can provide the basis to formulate at the microscopic level quantitative questions on the phenotype structure of multicellular organisms. The problem of explaining the robustness of the phenotype structure is rephrased as a real geometrical problem on a fixed domain. We further suggest a generalization of path integrals that reduces the problem of deciding whether a given molecular network can generate specific phenotypes to a numerical property of a robustness function with complex output, for which we give heuristic justification. Finally, we use our formalism to interpret a pointedly quantitative developmental biology problem on the allowed number of pairs of legs in centipedes