Air-guided photonic-crystal-fiber pulse-compression delivery of multimegawatt femtosecond laser output for nonlinear-optical imaging and neurosurgery

Cataloged from PDF version of article.Large-core hollow photonic- crystal fibers (PCFs) are shown to enable a fiber-format air-guided delivery of ultrashort infrared laser pulses for neurosurgery and nonlinear-optical imaging. With an appropriate dispersion precompensation, an anomalously dispersive 15-mu m-core hollow PCF compresses 510-fs, 1070-nm light pulses to a pulse width of about 110 fs, providing a peak power in excess of 5 MW. The compressed PCF output is employed to induce a local photodisruption of corpus callosum tissues in mouse brain and is used to generate the third harmonic in brain tissues, which is captured by the PCF and delivered to a detector through the PCF cladding. (C) 2012 American Institute of Physics

Implantable fiber-optic interface for parallel multisite long-term optical dynamic brain interrogation in freely moving mice

Seeing the big picture of functional responses within large neural networks in a freely functioning brain is crucial for understanding the cellular mechanisms behind the higher nervous activity, including the most complex brain functions, such as cognition and memory. As a breakthrough toward meeting this challenge, implantable fiber-optic interfaces integrating advanced optogenetic technologies and cutting-edge fiber-optic solutions have been demonstrated, enabling a long-term optogenetic manipulation of neural circuits in freely moving mice. Here, we show that a specifically designed implantable fiber-optic interface provides a powerful tool for parallel long-term optical interrogation of distinctly separate, functionally different sites in the brain of freely moving mice. This interface allows the same groups of neurons lying deeply in the brain of a freely behaving mouse to be reproducibly accessed and optically interrogated over many weeks, providing a long-term dynamic detection of genome activity in response to a broad variety of pharmacological and physiological stimuli

The mRubyFT Protein, Genetically Encoded Blue-to-Red Fluorescent Timer.

peer reviewedGenetically encoded monomeric blue-to-red fluorescent timers (mFTs) change their fluorescent color over time. mCherry-derived mFTs were used for the tracking of the protein age, visualization of the protein trafficking, and labeling of engram cells. However, the brightness of the blue and red forms of mFTs are 2-3- and 5-7-fold dimmer compared to the brightness of the enhanced green fluorescent protein (EGFP). To address this limitation, we developed a blue-to-red fluorescent timer, named mRubyFT, derived from the bright mRuby2 red fluorescent protein. The blue form of mRubyFT reached its maximum at 5.7 h and completely transformed into the red form that had a maturation half-time of 15 h. Blue and red forms of purified mRubyFT were 4.1-fold brighter and 1.3-fold dimmer than the respective forms of the mCherry-derived Fast-FT timer in vitro. When expressed in mammalian cells, both forms of mRubyFT were 1.3-fold brighter than the respective forms of Fast-FT. The violet light-induced blue-to-red photoconversion was 4.2-fold less efficient in the case of mRubyFT timer compared to the same photoconversion of the Fast-FT timer. The timer behavior of mRubyFT was confirmed in mammalian cells. The monomeric properties of mRubyFT allowed the labeling and confocal imaging of cytoskeleton proteins in live mammalian cells. The X-ray structure of the red form of mRubyFT at 1.5 Å resolution was obtained and analyzed. The role of the residues from the chromophore surrounding was studied using site-directed mutagenesis

Practical Recommendations of Scientific Society for the Study of Human Microbiome and Russian Gastroenterological Association (RGA) for Probiotics in Treatment and Prevention of Gastroenterological Diseases in Adults

Aim. To provide practical recommendations on the use of probiotics for the treatment and prevention of gastroenterological diseases in adults.General provisions. Probiotics are living microorganisms that benefit the health of the host when administered in adequate amounts. The main functions of probiotics include the support for colonisation resistance, the metabolism of food substrates and utilisation of end metabolites, the production of substrates necessary for the macro-organism, as well as the regulation of local and adaptive immune responses. Probiotics can be registered in the Russian Federation as biologically active food additives (BAFA) or as pharmaceutical products (drugs) in accordance with the microbiological standards and legislative requirements of the Russian Federation. The probiotics registered in the Russian Federation as BAFA for adults include bacteria of the Lactobacillus, Bifidobacterium, Enterococcus, Pediococcus, Lactococcus, Streptococcus, Bacillus, and Escherichia genera, and fungi of the Saccharomyces genus; probiotics registered as drugs — bacteria of Lactobid, Lactobacid, Escherichia and Enterococcus genera and fungi of the Saccharomyces genus. Some probiotics registered in the Russian Federation include probiotic strains that have proved to be effective for the prevention and treatment of antibiotic-associated diarrhea, the prevention of C. difficile-associated disease, the eradication of H. pylori infection, as well as for the treatment of irritable bowel syndrome and functional constipation.Conclusions. The clinical efficacy of probiotics depends on the probiotic strains included in their composition and is confirmed by a comparative analysis of the results of appropriate clinical studies. Not all probiotics registered in the Russian Federation as BAFA or drugs contain bacterial or fungal strains; as a result, the expected clinical effect may not be achieved

LSSmScarlet, dCyRFP2s, dCyOFP2s and CRISPRed2s, Genetically Encoded Red Fluorescent Proteins with a Large Stokes Shift

Genetically encoded red fluorescent proteins with a large Stokes shift (LSSRFPs) can be efficiently co-excited with common green FPs both under single- and two-photon microscopy, thus enabling dual-color imaging using a single laser. Recent progress in protein development resulted in a great variety of novel LSSRFPs; however, the selection of the right LSSRFP for a given application is hampered by the lack of a side-by-side comparison of the LSSRFPs’ performance. In this study, we employed rational design and random mutagenesis to convert conventional bright RFP mScarlet into LSSRFP, called LSSmScarlet, characterized by excitation/emission maxima at 470/598 nm. In addition, we utilized the previously reported LSSRFPs mCyRFP1, CyOFP1, and mCRISPRed as templates for directed molecular evolution to develop their optimized versions, called dCyRFP2s, dCyOFP2s and CRISPRed2s. We performed a quantitative assessment of the developed LSSRFPs and their precursors in vitro on purified proteins and compared their brightness at 488 nm excitation in the mammalian cells. The monomeric LSSmScarlet protein was successfully utilized for the confocal imaging of the structural proteins in live mammalian cells and multicolor confocal imaging in conjugation with other FPs. LSSmScarlet was successfully applied for dual-color two-photon imaging in live mammalian cells. We also solved the X-ray structure of the LSSmScarlet protein at the resolution of 1.4 Å that revealed a hydrogen bond network supporting excited-state proton transfer (ESPT). Quantum mechanics/molecular mechanics molecular dynamic simulations confirmed the ESPT mechanism of a large Stokes shift. Structure-guided mutagenesis revealed the role of R198 residue in ESPT that allowed us to generate a variant with improved pH stability. Finally, we showed that LSSmScarlet protein is not appropriate for STED microscopy as a consequence of LSSRed-to-Red photoconversion with high-power 775 nm depletion light

Practical Recommendations of Scientific Society for the Study of Human Microbiome and the Russian Gastroenterological Association on Use of Probiotics, Prebiotics, Synbiotics and Functional Foods in Treatment and Prevention of Gastroenterological Diseases in Children and Adults

Aim. The practical guidelines are intended for primary care physicians, general practitioners, paediatricians, gastroenterologists and general internists to advance the treatment and prevention of gastroenterological diseases in adults and children in therapies with probiotics, prebiotics, synbiotics and their enriched functional foods.Key points. Probiotics are live microorganisms that sustain health of the host when supplied in adequate amounts. Prebiotics include human-indigestible but accessible to gut microbiota substances expediting specific changes in the composition and/or activity of gastrointestinal microbiota that favour the host health. The mechanism of probiotic action comprises the quorum resistance maintenance, nutrient substrate metabolism and end metabolite recycling, macroorganism-sustaining substrate production, as well as the mediation of local and adaptive immune responses.The Russian Federation regulates market differently for biologically active food additives (BAFA), medicinal products (drugs) and functional food products (FFP). We overview the probiotic strains regulated in Russia as BAFAs, drugs and FFPs and provide recommendations on the use of these strains in treatment and prevention of gastroenterological diseases in children and adults.Conclusion. The clinical efficacy of probiotics, prebiotics, synbiotics and fortified functional foods depends on the prebiotic and strain properties and is verified in appropriate comparative clinical trials. Not all probiotics registered in Russia as BAFAs, drugs and FFPs have a strain identity, which provides no warranty of the clinical effect expected. The FFP legislation demands improved regulation mechanisms and control for therapeutic efficacy

Practical Recommendations of Scientific Society for the Study of Human Microbiome and the Russian Gastroenterological Association on Use of Probiotics, Prebiotics, Synbiotics and Functional Foods in Treatment and Prevention of Gastroenterological Diseases in Children and Adults

Aim. The practical guidelines are intended for primary care physicians, general practitioners, paediatricians, gastroenterologists and general internists to advance the treatment and prevention of gastroenterological diseases in adults and children in therapies with probiotics, prebiotics, synbiotics and their enriched functional foods.Key points. Probiotics are live microorganisms that sustain health of the host when supplied in adequate amounts. Prebiotics include human-indigestible but accessible to gut microbiota substances expediting specific changes in the composition and/or activity of gastrointestinal microbiota that favour the host health. The mechanism of probiotic action comprises the quorum resistance maintenance, nutrient substrate metabolism and end metabolite recycling, macroorganism-sustaining substrate production, as well as the mediation of local and adaptive immune responses.The Russian Federation regulates market differently for biologically active food additives (BAFA), medicinal products (drugs) and functional food products (FFP). We overview the probiotic strains regulated in Russia as BAFAs, drugs and FFPs and provide recommendations on the use of these strains in treatment and prevention of gastroenterological diseases in children and adults.Conclusion. The clinical efficacy of probiotics, prebiotics, synbiotics and fortified functional foods depends on the prebiotic and strain properties and is verified in appropriate comparative clinical trials. Not all probiotics registered in Russia as BAFAs, drugs and FFPs have a strain identity, which provides no warranty of the clinical effect expected. The FFP legislation demands improved regulation mechanisms and control for therapeutic efficacy