274 results match your criteria: "St. Petersburg University[Affiliation]"

Quantitative determination of albumin and immunoglobulin in human serum using gold nanoclusters.

Spectrochim Acta A Mol Biomol Spectrosc

October 2023

Department of Molecular Biophysics and Polymer Physics, St Petersburg University, 199034 Saint Petersburg, Russia.

In this experimental study, we developed a simple and selective approach to determine the concentrations of human serum albumin (HSA) and total amount of immunoglobulins (Ig) in real human serum (HS) sample using luminescent gold nanoclusters (Au NCs). In doing so, Au NCs were grown directly on the HS proteins without any sample pretreatment. We synthesized Au NCs on HSA and Ig and studied their photophysical properties.

View Article and Find Full Text PDF

Highly diverse but divergent microeukaryotes dwell in all types of habitats in urban park ecosystems. Extensive microbial migration occurs between both terrestrial and aquatic habitats. Microbial movement is beneficial to the maintenance of biodiversity and the exchange of functional guilds.

View Article and Find Full Text PDF

The studies on the demand for healthcare in low- and middle-income countries rarely take into consideration the fact that many people spend their income on self-treatment and professional treatment. The estimation of the income elasticity of demand for self-treatment and professional treatment can show a more precise picture of the affordability of professional care. This paper contributes to the discussion around estimates of income elasticity of health spending and discussion whether professional care and self-treatment are close to a luxury good and inferior good respectively in a middle-income country.

View Article and Find Full Text PDF

Restoration of anthropogenically disturbed soils is an urgent problem in modern ecology and soil biology. Restoration processes in northern environments are especially important, due to the small amounts of fertile land and low levels of natural succession. We analyzed the soil microbiota, which is one of the indicators of the succession process is the soil.

View Article and Find Full Text PDF

A series of compounds - bearing terminal alkynyl sites connected with a phosphonium group via different π-conjugated linkers have been synthesized. The compounds themselves are efficient push-pull emitters and exhibit bright fluorescence in blue and near-UV regions. - were used as alkynyl ligands to obtain a series of homoleptic bis-alkynyl Au(I) complexes -.

View Article and Find Full Text PDF

A novel series of cyclometalated platinum(II) complexes bearing acyclic diaminocarbene (ADC) ancillary ligands were designed and prepared. Their photophysical properties were systematically studied through experimental and theoretical investigations. All complexes exhibit green phosphorescence with a quantum efficiency of up to 45% in 2 wt% doped PMMA film at room temperature.

View Article and Find Full Text PDF

Underwater wet welding is commonly used in joining pipelines and in underwater construction. Harmful and hazardous compounds are added to many flux-cored wires for underwater welding and cutting, and can have a negative impact on marine life. The specific objective of this study was to evaluate the aquatic toxicity of two suspension samples obtained using welding electrode and flux-cored wire in marine microalgae and .

View Article and Find Full Text PDF

The provenance study of archaeological materials is an important step in understanding the cultural and economic life of ancient human communities. One of the most popular approaches in provenance studies is to obtain the chemical composition of material and process it with chemometric methods. In this paper, we describe a combination of the total-reflection X-ray fluorescence (TXRF) method and chemometric techniques (PCA, k-means cluster analysis, and SVM) to study Neolithic ceramic samples from eastern Siberia (Baikal region).

View Article and Find Full Text PDF

ZnTe Crystal Multimode Cryogenic Thermometry Using Raman and Luminescence Spectroscopy.

Materials (Basel)

February 2023

Center for Optical and Laser Materials Research, St. Petersburg University, Universitetskaya nab. 7-9, 199034 St. Petersburg, Russia.

In this study, ZnTe crystal was applied to provide precise thermal sensing for cryogenic temperatures. Multiple techniques, namely Raman and photoluminescence spectroscopies, were used to broaden the operating temperature range and improve the reliability of the proposed thermometers. Raman-based temperature sensing could be applied in the range of 20-100 K, while luminescence-based thermometry could be utilized in a narrower range of 20-70 K.

View Article and Find Full Text PDF

Objective: When performing laparoscopic intraperitoneal hernioplasty (IPOM), endoprostheses made of fluoropolymers are often used. However, there is no data in the literature on the intra-abdominal use of inexpensive polyester prostheses with a fluoropolymer coating compared to composite implants. Thus, the aim of the pilot study was a preliminary assessment of the safety profile of FTOREX mesh endoprostheses during intra-abdominal placement in large animals.

View Article and Find Full Text PDF

Metchnikovellids (Microsporidia: Metchnikovellida) are poorly studied hyperparasitic microsporidia that live in gregarines inhabiting the intestines of marine invertebrates, mostly polychaetes. Our recent studies showed that diversity of metchnikovellids might be significantly higher than previously thought, even within a single host. Four species of metchnikovellids were found in the gregarines inhabiting the gut of the polychaete Pygospio elegans from littoral populations of the White and Barents Seas: the eugregarine Polyrhabdina pygospionis is the host for Metchnikovella incurvata and M.

View Article and Find Full Text PDF

Parkinson's disease is the second most common neurodegenerative pathology. Due to the limitations of existing therapeutic approaches, novel anti-parkinsonian medicines with non-dopamine mechanisms of action are clearly needed. One of the promising pharmacological targets for anti-Parkinson drug development is phosphodiesterase (PDE) 10A.

View Article and Find Full Text PDF

Quantitative analysis of spent nuclear fuel (SNF) is a very challenging task. High radioactivity, complex chemical composition and personnel safety requirements severely limit the number of analytical tools suitable for this problem. There is an urgent need for the methods that would provide for remote on-line quantification of elements in spent nuclear fuel and its reprocessing technological solutions.

View Article and Find Full Text PDF

Photoluminescent lanthanide complexes of Eu and Tb as central atoms and ,-diisopropyl-[2,2'-bipyridine]-6,6'-dicarboxamide as ligand were synthesized. The structure of these complexes was established by single-crystal X-ray diffraction, mass spectrometry, H and C nuclear magnetic resonance, ultraviolet-visible, infrared spectroscopy, and thermogravimetry. Bipyridinic ligands provide formation of coordinatively saturated complexes of lanthanide ions and strong photoluminescence (PL).

View Article and Find Full Text PDF

Gut Microbiota Alterations in Trace Amine-Associated Receptor 9 (TAAR9) Knockout Rats.

Biomolecules

December 2022

Institute of Translational Biomedicine, Saint Petersburg State University, Universitetskaya nab. 7/9, 199034 Saint Petersburg, Russia.

Trace amine-associated receptors (TAAR1-TAAR9) are a family of G-protein-coupled monoaminergic receptors which might have great pharmacological potential. It has now been well established that TAAR1 plays an important role in the central nervous system. Interestingly, deletion of TAAR9 in rats leads to alterations in the periphery.

View Article and Find Full Text PDF

Pulsar wind nebulae are formed when outflows of relativistic electrons and positrons hit the surrounding supernova remnant or interstellar medium at a shock front. The Vela pulsar wind nebula is powered by a young pulsar (B0833-45, aged 11,000 years) and located inside an extended structure called Vela X, which is itself inside the supernova remnant. Previous X-ray observations revealed two prominent arcs that are bisected by a jet and counter jet.

View Article and Find Full Text PDF

Cocaine is a powerful psychostimulant that is one of the most widely used illicit addictive. The dopamine transporter (DAT) plays a major role in mediating cocaine's reward effect. Decreases in DAT expression increase rates of drug abuse and vulnerability to comorbid psychiatric disorders.

View Article and Find Full Text PDF

The attachment of functional DNA to gold nanoparticles via polyadenine adsorption is a well-established technology. This approach was mainly viewed through the lens of changing the DNA charge in order to reduce the electrostatic barrier created by a similarly charged gold surface. However, altering the DNA charge results in the loss of its functionality.

View Article and Find Full Text PDF

The Trace Amine-Associated Receptor 1 (TAAR1) is one of the six functional receptors belonging to the family of monoamine-related G protein-coupled receptors (TAAR1-TAAR9) found in humans. However, the exact biological mechanisms of TAAR1 central and peripheral action remain to be fully understood. TAAR1 is widely expressed in the prefrontal cortex and several limbic regions, interplaying with the dopamine system to modulate the reward circuitry.

View Article and Find Full Text PDF

Most of the light from blazars, active galactic nuclei with jets of magnetized plasma that point nearly along the line of sight, is produced by high-energy particles, up to around 1 TeV. Although the jets are known to be ultimately powered by a supermassive black hole, how the particles are accelerated to such high energies has been an unanswered question. The process must be related to the magnetic field, which can be probed by observations of the polarization of light from the jets.

View Article and Find Full Text PDF

Polarized x-rays from a magnetar.

Science

November 2022

Guangxi Key Laboratory for Relativistic Astrophysics, School of Physical Science and Technology, Guangxi University, Nanning 530004, China.

Magnetars are neutron stars with ultrastrong magnetic fields, which can be observed in x-rays. Polarization measurements could provide information on their magnetic fields and surface properties. We observed polarized x-rays from the magnetar 4U 0142+61 using the Imaging X-ray Polarimetry Explorer and found a linear polarization degree of 13.

View Article and Find Full Text PDF

nablaDFT: Large-Scale Conformational Energy and Hamiltonian Prediction benchmark and dataset.

Phys Chem Chem Phys

November 2022

AIRI, Kutuzovskiy prospect house 32 building K.1, Moscow, 121170, Russia.

Electronic wave function calculation is a fundamental task of computational quantum chemistry. Knowledge of the wave function parameters allows one to compute physical and chemical properties of molecules and materials. Unfortunately, it is infeasible to compute the wave functions analytically even for simple molecules.

View Article and Find Full Text PDF

In the USA, governors became central figures in the fight against the novel coronavirus. In many cases, state leaders were forced to choose between preserving life and protecting economic livelihood. While prior research has underscored the important role that US governors played in implementing healthcare policies at the onset of the COVID-19 pandemic, we know little about how characteristics of state leaders impacted self-employment.

View Article and Find Full Text PDF

CuAAC (Cu catalyzed azide-alkyne cycloaddition) click-reaction is a simple and powerful method for the post-synthetic modification of organometallic complexes of transition metals. This approach allows the selective introduction of additional donor sites or functional groups to the periphery of the ligand environment. This is especially important if a metalloligand with free donor sites, which are of the same nature as the primary site for the coordination of the primary metal, has to be created.

View Article and Find Full Text PDF