Spatial Modulation Microscopy for Real-Time Imaging of Plasmonic Nanoparticles and Cells

Spatial modulation microscopy is a technique originally developed for quantitative spectroscopy of individual nano-objects. Here, a parallel implementation of the spatial modulation microscopy technique is demonstrated based on a line detector capable of demodulation at kHz frequencies. The capabilities of the imaging system are shown using an array of plasmonic nanoantennas and dendritic cells incubated with gold nanoparticles.Comment: 3 pages, 4 figure

Optical detection of single non-absorbing molecules using the surface plasmon of a gold nanorod

Current optical detection schemes for single molecules require light absorption, either to produce fluorescence or direct absorption signals. This severely limits the range of molecules that can be detected, because most molecules are purely refractive. Metal nanoparticles or dielectric resonators detect non-absorbing molecules by a resonance shift in response to a local perturbation of the refractive index, but neither has reached single-protein sensitivity. The most sensitive plasmon sensors to date detect single molecules only when the plasmon shift is amplified by a highly polarizable label or by a localized precipitation reaction on the particle's surface. Without amplification, the sensitivity only allows for the statistical detection of single molecules. Here we demonstrate plasmonic detection of single molecules in realtime, without the need for labeling or amplification. We monitor the plasmon resonance of a single gold nanorod with a sensitive photothermal assay and achieve a ~ 700-fold increase in sensitivity compared to state-of-the-art plasmon sensors. We find that the sensitivity of the sensor is intrinsically limited due to spectral diffusion of the SPR. We believe this is the first optical technique that detects single molecules purely by their refractive index, without any need for photon absorption by the molecule. The small size, bio-compatibility and straightforward surface chemistry of gold nanorods may open the way to the selective and local detection of purely refractive proteins in live cells

Трансформированный вариант диффузной В-клеточной крупноклеточной лимфомы желудка у пациентки с сочетанием болезни Шегрена и системной склеродермии (описание случая и обзор литературы)

This article describes a case of a transformed diffuse large B-cell lymphoma of the stomach in a patient with Sjogren’s disease (SjD) and systemic sclerosis (SSc), as well as a brief review of the literature on lymphoproliferative diseases in SjD and SSc.Представлены описание случая трансформированного варианта диффузной В-клеточной крупноклеточной лимфомы желудка у пациентки с болезнью Шегрена (БШ) и лимитированной системной склеродермией (ССД), а также краткий обзор литературы, посвященной лимфопролиферативным заболеваниям при БШ и ССД. Обсуждаются связи между указанными состояниями

Manipulating Protein Conformations By Single-molecule Afm-fret Nanoscopy

Combining atomic force microscopy and fluorescence resonance energy transfer spectroscopy (AFM-FRET), we have developed a single-molecule AFM-FRET nanoscopy approach capable of effectively pinpointing and mechanically manipulating a targeted dye-labeled single protein in a large sampling area and simultaneously monitoring the conformational changes of the targeted protein by recording single-molecule FRET time trajectories. We have further demonstrated an application of using this nanoscopy on manipulation of single-molecule protein conformation and simultaneous single-molecule FRET measurement of a Cy3-Cy5-labeled kinase enzyme, HPPK (6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase). By analyzing time-resolved FRET trajectories and correlated AFM force pulling curves of the targeted single-molecule enzyme, we are able to observe the protein conformational changes of a specific coordination by AFM mechanic force pulling

Diagnosis of IgG4 - related ophthalmic disease in a group of patients with various lesions of the eye and orbits

Purpose of the study. To provide demographic, clinical, laboratory, ultrasound, radiological, morphological/ immunomorphological phenotype of IgG4-related ophthalmic diseases, which allowsmaking a differential diagnosis with granulomatous, autoimmune, inflammatory, endocrine and hematologic diseases affecting the eye and orbits. Materials and methods. From 2004 to 2016 108 (78.2%) of the 138 patients were diagnosed with non-tumoral lesions of eye and orbits. In 48 patients (35%) at admission and 5 patients in the follow were diagnosed IgG4-related ophthalmic disease. In the analysis of 82 (f-44, m-38) patients with IgG4-related disease, localization of lesions in orbit observed in 53 (f-36, m-17) and it was the most frequent involvement in patients with IgG4-related disease (64.5%). Only 7 patients had isolated IgG4-related ophthalmic disease, whereas 46 patients (87%) had involvement of 2-7 locations, as a manifestation of IgG4-related systemic disease.During the examination, the average age of patients with IgG4-related ophthalmic disease was 47.5 years (19-73 years). Median time to diagnosis was 52.8 months before 2004 and 36 months 2004-2016. Results. We noted the predominance of females in the ratio 2: 1 inthe group of patients with IgG4-related ophthalmic disease. Edema of the eyelids, nasal congestion (55-60%), tumor-like formations of the upper eyelids and increased lacrimation prevailed at the onset of the disease, whereas such functional impairment like limited mobility and pain in eyeballs, exophthalmos, ptosis and diplopia appeared later at 15-38% with a loss visual acuity in one case. Bilateral lesion (86%), mainly affecting the lacrimal glands (93.5%), infiltration of the extraocular muscles (83.5%) and retrobulbar tissue with a thickening of the optic nerve in one third of patients were the main localizations IgG4-related ophthalmic disease. Clinical symptoms were accompanied by the appearance of moderate inflammatory activity (38%), increased levels IgG (44%), IgG4(88%) and IgE (61%). Indicators of autoimmune disorders observed in 6-22% of patients, most often in patients with simultaneous involvement of the salivary glands. Significant lymphoplasmacytic infiltration (94%) with a ratio of plasma cells (IgG4/IgG) secreting IgG4> 40% (90%) with fibrosis formation (94%) and follicle formation (71%) with a moderate amount of eosinophils (34%) were the major morphological / immunomorphological manifestations of IgG4-related ophthalmic disease. Signs of vasculitis and obliterative phlebitis were found in a small amount of patients. Conclusion. Determination of elevated levels of IgG-4 / IgE in patients with edema, pseudotumor of the eyelid, sinusitis and increase of the palpebral lobe of the lacrimal gland suggests the presence of IgG4-related ophthalmic disease. Minimally invasive incisional biopsy of lacrimal glands and salivary glands followed by morphological / immunomorphological research is needed for the correct diagnosis. Diagnostic orbitotomy in ophthalmic hospitals in such cases is inexpedient, since it leads to the development of dry eye. Massive lymphoplasmacytic infiltration with IgG4 / IgG ratio more than 40%, advanced fibrosis in biopsiesof the orbits tissue or salivary glands when combined lesions are required for the making the diagnosis of IgG4-related ophthalmic disease

Femtosecond Coherence and Quantum Control of Single Molecules at Room Temperature

Quantum mechanical phenomena, such as electronic coherence and entanglement, play a key role in achieving the unrivalled efficiencies of light-energy conversion in natural photosynthetic light-harvesting complexes, and triggered the growing interest in the possibility of organic quantum computing. Since biological systems are intrinsically heterogeneous, clear relations between structural and quantum-mechanical properties can only be obtained by investigating individual assemblies. However, single-molecule techniques to access ultrafast coherences at physiological conditions were not available so far. Here we show by employing femtosecond pulse-shaping techniques that quantum coherences in single organic molecules can be created, probed, and manipulated at ambient conditions even in highly disordered solid environments. We find broadly distributed coherence decay times for different individual molecules giving direct insight into the structural heterogeneity of the local surroundings. Most importantly, we induce Rabi-oscillations and control the coherent superposition state in a single molecule, thus performing a basic femtosecond single-qubit operation at room temperature

Database-driven High-Throughput Calculations and Machine Learning Models for Materials Design

This paper reviews past and ongoing efforts in using high-throughput ab-inito calculations in combination with machine learning models for materials design. The primary focus is on bulk materials, i.e., materials with fixed, ordered, crystal structures, although the methods naturally extend into more complicated configurations. Efficient and robust computational methods, computational power, and reliable methods for automated database-driven high-throughput computation are combined to produce high-quality data sets. This data can be used to train machine learning models for predicting the stability of bulk materials and their properties. The underlying computational methods and the tools for automated calculations are discussed in some detail. Various machine learning models and, in particular, descriptors for general use in materials design are also covered.Comment: 19 pages, 2 figure

Electrons, Photons, and Force: Quantitative Single-Molecule Measurements from Physics to Biology

Single-molecule measurement techniques have illuminated unprecedented details of chemical behavior, including observations of the motion of a single molecule on a surface, and even the vibration of a single bond within a molecule. Such measurements are critical to our understanding of entities ranging from single atoms to the most complex protein assemblies. We provide an overview of the strikingly diverse classes of measurements that can be used to quantify single-molecule properties, including those of single macromolecules and single molecular assemblies, and discuss the quantitative insights they provide. Examples are drawn from across the single-molecule literature, ranging from ultrahigh vacuum scanning tunneling microscopy studies of adsorbate diffusion on surfaces to fluorescence studies of protein conformational changes in solution