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A comparative spectral study of the complex formation of molecules of nitro-substituted indoline spiropyrans with metal ions in acetonitrile and water–acetonitrile solutions, and also in acid-containing acetonitrile, was carried out. It was shown that metal complexes are not formed in the presence of water, due to protonation of photochromic spiropyran molecules. Spectral and photochromic properties of the protonated complexes obtained in the presence of water differ from those of protonated complexes arising upon interaction with an acid. A photochromic method for detecting metal ions in aqueous solutions was proposed.

Raman scattering spectra in single crystals of lithium tantalate at 180-degree scattering geometry in a wide spectral frequency range (50 ÷ 2800 cm−1) were studied. Raman peaks were found in 1300 ÷...

Raman scattering (RS) spectra in lithium tantalate single crystals are studied at 180-degree scattering geometry in a wide frequency spectral range (50–2500 cm–1). RS intensity peaks corresponding to fundamental transverse (TO) and longitudinal (LO) polar optical modes of this crystal are recorded. It is found that the high-frequency spectral range (1300–2000 cm–1) contains RS intensity peaks whose frequencies exceed doubled frequencies of A1- and E-type fundamental vibrations of the LiTaO3 lattice. The intensity of these peaks appeared comparable to the intensity of lines corresponding to A1- and E-type fundamental transverse and longitudinal polar optical modes. The conditions of the appearance of bound states of polar phonons in the RS spectra of lithium tantalate crystal are analyzed.

Background Patients with systemic lupus erythematous have a significantly increased risk of cardiovascular disease, which is not fully explained by traditional cardiovascular disease risk factors. Despite increasing life expectancy in patients with systemic lupus erythematous, mortality due to cardiovascular disease, the major cause of death in these patients, has not changed. Children with lupus suffer from more aggressive disease compared to their adult counterparts, and there is a growing concern for their increased risk of cardiovascular disease as they age. Body: There is an unmet need for therapies to address the increased risk of cardiovascular disease in childhood-onset lupus. Colchicine has many anti-inflammatory and cardiovascular protective properties, including inhibition of IL-1β and IL-18 activity, key proinflammatory cytokines that are predictive of future adverse cardiovascular events. In the Colchicine Cardiovascular Outcomes Trial (COLCOT), colchicine was recently found to have significant benefit with minimal risk in adults with previous myocardial infarction for prevention of secondary vascular disease. While adult studies are promising, no studies have been conducted in pediatric patients to investigate colchicine’s potential for cardiovascular protection in children and adolescents with lupus. Conclusions Studies investigating colchicine’s potential role for cardiovascular protection are needed in pediatric patients with systemic lupus erythematous.

Site-selective oxidations of carbohydrates, employing acridinium photocatalysis and quinuclidine hydrogen atom transfer catalysis, are presented. Protocols have been developed for oxidations of all-equatorial carbohydrates as well as those containing cis-1,2-diols. Site-selectivity reflects the relative rates of hydrogen atom transfer from the carbohydrate C-H bonds, and can be enhanced using a phosphate hydrogen-bonding or boronic acid catalyst.

One-dimensional ferroelectric photonic crystals have been produced by filling porous anodic aluminum oxide with sodium nitrite. Introducing sodium nitrite into the pores of the photonic crystals has been shown to cause a 40-nm bathochromic shift in the spectral position of their bandgap. The results of this study demonstrate the feasibility of using aluminum oxide-based composite photonic crystals as narrow-band selective mirrors.

A method has been demonstrated for doping carbon nanotubes (CNTs) with nitrogen during synthesis in an acetylene + ammonia atmosphere at different temperatures in the range 550–750°C, and conditions have been found for effective nitrogen doping of CNTs depending on synthesis temperature. The concentrations of various elements in the synthesized CNTs have been determined by X-ray photoelectron spectroscopy. Raman measurements with the use of a Raman microscope have made it possible to follow variations in the relative intensities of the G and D bands as functions of nitrogen dopant concentration in the CNTs. We have detected strong Raman overtone combination satellites whose parameters depend on the structural perfection of the synthesized CNTs.

Reported are the results of studying the sharp increase in the spectral intensity at the lattice soft mode near the temperature of the phase transition in the lithium tantalate crystal. The Raman scattering spectra are recorded in the x(zz)y polarization geometry corresponding to manifestation of the soft mode responsible for the ferroelectric phase transition in lithium tantalate at 898 K. The recording is performed at fixed temperatures T ( $$I(\omega {\kern 1pt} ',T)$$ , T = const) and at fixed spectrometer frequencies ( $$I(\omega {\kern 1pt} ',T)$$ , $$\omega {\kern 1pt} ' = {{\omega }_{0}} - T = {\text{const}}$$ ) under slow (1 deg./min) crystal temperature variation. Strong increase (by three orders of magnitude) is observed in the peak of the reduced spectral intensity i0(Ω) of the isofrequency temperature dependence at the fixed spectrometer frequency shift relative to the exciting radiation $$\Omega = {{\omega }_{0}} - \omega {\kern 1pt} ' = 10$$ cm–1 similar to the one earlier observed in quartz crystals.

Using pulses of multifrequency stimulated Raman scattering (SRS) in calcite, nonlinear photoluminescence in a stilbene molecular crystal is excited. When multifrequency SRS is excited by the radiation of a Nd3+ : YAG laser with a wavelength of 1064 nm, eleven anti-Stokes components are observed in the visible spectrum with an average frequency shift of 1086 cm−1 between them. Using the second harmonic of the Nd 3+ : YAG laser radiation allowed three anti-Stokes and four Stokes components to be recorded. The large spectral range of the frequency comb facilitated effective reduction in the duration and increase in the intensity of the radiation pulse of multifrequency SRS.

A recombination center formed by Ti+3 and an oxygen vacancy that plays an important role in photocatalytic processes is investigated. A photoluminescence band with a maximum at 1.236 eV was observed upon excitation of titanium oxide by laser radiation with a wavelength of 785 nm. This band appears after crystallization of an amorphous titanium-dioxide film for 30 min in vacuum at 650°С. The shape of the band was studied by the method of moments, and parameters of its electron−phonon interaction, namely, the energy of a purely electron transition equal to 1.28 eV, the Huang−Rhys factor equal to 2, and heat release of 0.04 eV, were obtained. These values can be used for calculation of parameters of kinetic coefficients of electronic transitions in strong electric fields.

High cattle productivity related with intensive metabolism and intake of all nutrients in a certain amount. The blood chemistry value of cows taken biopreparation “Albit-Bio” was determined in this study. Thus, there was a correlation between the protein composition of the cow’s blood and the colostrum. In particular, in the first batch of cow’s colostrum, the dry matter content of the control and experimental groups of cows was 32.59±1.87%, and 38.09±0.93%, respectively. Similar differences were found in the content of other components of colostrum, which was the result of differences in the intensity of protein metabolism in animals. A positive correlation was found between the total protein content in the blood and the dry matter. The highest correlation coefficients were obtained from cows of the experimental group.

The conditions for the excitation of transverse and longitudinal polar modes in the processes of Raman scattering of light in mono- and polydomain lithium tantalate single crystals are established using a backscattering geometry. The relative intensity of the overtone Raman spectrum on the longitudinal and transverse fundamental polar excitations is much higher in the polydomain sample. Unfortunately, the exact reason for the difference in the Raman spectra of the mono- and polydomain lithium tantalate samples is unknown. The frequencies of the two overtone bands exceeded the exact value of the overtone frequency corresponding to the fundamental longitudinal polar mode $4{A}_{1}(\text{LO})$, which clearly indicates the existence of bound phonon pairs (biphonons). This is consistent with theory and has been shown for both mono- and polydomain samples. On the basis of the general theory of bound states of quasiparticles, the possibility of the existence of bound states of quadrupole excitations of the antipolar type in the vibrational spectrum of a polydomain crystal of lithium tantalate is predicted.

A spectroscopic study of photochromic systems containing two-dimensional CdSe nanoparticles (colloidal quantum wells) and photochromic compounds of the thermally relaxing chromene and thermally irreversible diarylethene classes in solutions was carried out. First, the systems were found to exhibit modulation of emission of two-dimensional nanoparticles in accordance with the photochromic transformations of compounds due to Förster resonance energy transfer (FRET) from the two-dimensional nanoparticles to photoinduced photochromic isomers.

Raman spectra of tryptophan and tyrosine polycrystals have been analyzed in a wide spectral range by fiber-optic spectroscopy. The Raman spectra have been recorded with a BWS465-785H spectrometer in the spectral range of 0–2700 cm–1 using a 785-nm cw laser as an excitation source. Parameters of the Raman spectra are compared for three crystalline phase modifications of aromatic amino acids: left-handed, right-handed, and racemic phase. The presence of strong Raman satellites, the characteristics of which change depending on the type of the chiral phase state of amino acid, is found in the low-frequency Raman spectra of tryptophan and tyrosine amino acid lattices. The results obtained can be used for monitoring the chiral purity of bioactive preparations containing amino acids.

Overtone bands in the spectral range of 1300−1920 cm–1 have been found in Raman scattering spectrum of lithium tantalate single crystals. The Raman spectra were recorded in the 180° scattering geometry. The intensity of overtone transitions differs for different samples and, in some cases, is comparable with the Raman scattering intensity at the fundamental modes of a lithium tantalate single crystal.

Regularities in the Raman spectra of acetate uranyl compounds CsUO2(CH3COO)3, CsUO2(CD3COO)3, NaUO2(CH3COO)3, NaUO2(CD3COO)3, UO2(CH3COO)2, and RbUO2(CH3COO)3 have been analyzed. The Raman spectra are excited by 785-nm laser radiation and recorded using a miniature fiber-optic spectrometer with a multielement detector. It is established that the spectra of all these compounds contain a strong Raman satellite with a frequency in the range of 850–860 cm–1. This satellite corresponds to symmetric stretching vibrations (type A1) of the uranyl group. The obtained results make it possible to detect and analyze small amounts of uranyl compounds.

We have measured photoluminescence spectra of uranyl nitrate (UO2(NO3)2) crystals and a UO2(NO3)2-filled opal crystal. The spectra have been compared to the corresponding photoluminescence spectrum of photonic glass. The photoluminescence spectra were excited by semiconductor light-emitting diodes, a cw laser, and repetitive laser pulses. The excitation wavelengths were located in the resonance absorption band of the uranyl compound. This has offered the possibility of measuring the photoluminescence spectrum of UO2(NO3)2 at an acquisition time of 1 ms, using the smallest possible amount of the substance (down to 10–9 g). The spectra have been obtained in the range 200–1000 nm using a fiber-optic minispectrometer.

We have found conditions for high-speed measurements of Raman spectra of lithium niobate and lithium tantalate single crystals and ceramics. To measure Raman spectra, we used 180° scattering geometry and a minispectrometer equipped with an array detector. The Raman spectra obtained at two distinct orientations of the single crystals relative to the excitation beam direction have been shown to have different frequencies of transverse and longitudinal optical modes. The Raman spectra of the ceramics are mainly contributed by transverse optical modes.

The spectra of multifrequency parametric stimulated Raman scattering in a barium nitrate single crystal is investigated. When this single crystal is excited by ultrashort (80 ps) YAG : Nd3+ laser pulses with a wavelength of 1064 nm, a frequency comb of eight anti-Stokes components is observed in the visible spectral range. The Raman satellites are due to the totally symmetric vibrational modes of barium nitrate single crystal. The frequencies of the corresponding Raman Stokes components in the IR range (from 1193 to 9662 nm) are calculated. The results of the study open the way to form an array of laser frequencies from the IR to green spectral range with a period of 1047 cm–1.

Cerebral amyloid-β (Aβ) plaques are the hallmark biomarker of Alzheimer’s disease (AD) and are detectable decades before clinical symptoms. Modifying risk factors associated with Aβ accrual offers an opportunity for AD prevention. While midlife vascular health is linked to AD; there is minimal longitudinal evidence regarding the effect of midlife lipids on Aβ. We examined the association between midlife lipids and Aβ 20 years later. One hundred and twenty-two women had serum lipid profiles in midlife (1992, 45–57 years), and cerebral imaging, genotyping, and cognition measured 20 years later (2012/13, 66–77 years). Imaging was performed in 2012/13 via F-18 Florbetaben positron emission tomography (PET) and standard uptake value ratios (SUVR) were calculated. Lipid profiles and other predictors of high PET-SUVR levels (>1.2) were evaluated using multivariable logistic regression. Increases in low-density lipoprotein (LDL) cholesterol in midlife were associated with Aβ, adjusting for age, education, cholesterol medication, and cognition (AdjOR1.81, 95% CI 1.08–3.01, p = 0.024), but attenuated on adjustment for apolipoprotein E4 (APOE ɛ4). Aβ risk increased in women with APOE ɛ4 and midlife cholesterol >6.2 mmol/L (AdjOR9.59, 95% CI 2.94–31.31, p 3.3 mmol/L (AdjOR9.00, 95% CI 2.89–28.03, p

Diorganotin dihalides act as cocatalysts for site-selective and stereoselective couplings of diol-containing carbohydrates with electron-deficient alkenes in the presence of an Ir(III) photoredox catalyst and quinuclidine, a hydrogen atom transfer mediator. Quantum-chemical calculations support a proposed mechanism involving the formation of a cyclic stannylene acetal intermediate that shows enhanced reactivity toward hydrogen atom abstraction by the quinuclidinium radical cation. Addition of the carbon-centered radical to the alkene partner results in C-alkylation of the carbohydrate substrate.

Data on therapy of COVID-19 in immunocompetent and immunosuppressed children are scarce. We aimed to explore management strategies of pediatric rheumatologists. All subscribers to international Pediatric Rheumatology Bulletin Board were invited to take part in an online survey on therapeutic approaches to COVID-19 in healthy children and children with autoimmune/inflammatory diseases (AID). Off-label therapies would be considered by 90.3% of the 93 participating respondents. In stable patients with COVID-19 on oxygen supply (stage I), use of remdesivir (48.3%), azithromycin (26.6%), oral corticosteroids (25.4%) and/or hydroxychloroquine (21.9%) would be recommended. In case of early signs of “cytokine storm” (stage II) or in critically ill patients (stage III) (a) anakinra (79.5% stage II; 83.6% stage III) or tocilizumab (58.0% and 87.0%, respectively); (b) corticosteroids (oral 67.2% stage II, intravenously 81.7% stage III); (c) intravenous immunoglobulins (both stages 56.5%); or (d) remdesivir (both stages 46.7%) were considered. In AID, > 94.2% of the respondents would not support a preventive adaptation of the immunomodulating therapy. In case of mild COVID-19, more than 50% of the respondents would continue pre-existing treatment with immunoglobulins (100%), hydroxychloroquine (94.2%), anakinra (79.2%) or canakinumab (72.5%), or tocilizumab (69.8%). Long-term corticosteroids would be reduced by 26.9% ( 2 mg/kg/day), respectively, with only 5.8% of respondents voting to discontinue the therapy. Conversely, more than 75% of respondents would refrain from administering cyclophosphamide and anti-CD20-antibodies. As evidence on management of pediatric COVID-19 is incomplete, continuous and critical expert opinion and knowledge exchange is helpful. Supplementary Information The online version contains supplementary material available at 10.1007/s00296-021-04824-4.

The ultrahigh porosity and varied functionalities of porous metal–organic frameworks make them excellent candidates for applications that range widely from gas storage and separation to catalysis and sensing. An interesting feature of some frameworks is the ability to open their pores to a specific guest, enabling highly selective separation. A prerequisite for this is bistability of the host structure, which enables the framework to breathe, that is, to switch between two stability minima in response to its environment. Here we describe a porous framework DUT-8(Ni)—which consists of nickel paddle wheel clusters and carboxylate linkers—that adopts a configurationally degenerate family of disordered states in the presence of specific guests. This disorder originates from the nonlinear linkers arranging the clusters in closed loops of different local symmetries that in turn propagate as complex tilings. Solvent exchange stimulates the formation of distinct disordered frameworks, as demonstrated by high-resolution transmission electron microscopy and diffraction techniques. Guest exchange was shown to stimulate repeatable switching transitions between distinct disorder states. Some flexible metal–organic frameworks are known to exhibit an adaptive behaviour as they convert between two stable forms in response to their environment. Now, a metal–organic framework based on nonlinear linkers has been shown to adopt a much more complex family of degenerate disordered configurations, which can be reversibly interconverted through guest exchange.

Summary Proven reserves of «traditional» oil are on a declining trend. Therefore, it is necessary for producing companies to consider hard-to-recover reserves as a resource base in the future. Currently, the term «hard-to-recover reserves» is not defined enough. Some categories of the hard-to-recover reserves may be deleted from this list due to the development of technology, making the production of hydrocarbons much easier. However, an exploration of subsurface using modern technology makes it possible to produce these hydrocarbon reserves. That was impossible previously. The examples are the production of Permian petroleum bitumen and the development of domanic formations.

The study of the effect of chitosan succinate use on the hematological indicators of dairy cows is relevant. It has been established that there was a clear tendency to increase in the number of white blood cells by 10.12% in animals of group 3 (P < 0.1) on the 10th day of the experiment in cows receiving low-molecular-weight chitosan succinate, in the second group the increase in this indicator by 2.94% was unreliable. On the 20th day of the experiment, an intensive increase in the number of white blood cells was observed in animals of both experimental groups by 14.63–17.38% (P≤0.01), respectively, for the experimental groups of cows. On the 10th day on the background of the use of low-molecular-weight chitosan (group 3), a significant decrease in the number of red blood cells was found, compared with the background, by 8.34% (P≤0.05). On the 20th day, the decrease in the number of red blood cells was already significant in both experimental groups, and their level was 6.09±0.33...6.38±0.20·109/l (P≤0.05), respectively. On the 60th day of the study, this trend was maintained only in group 3, and the concentration of red blood cells was lower by 12.64 (P < 0.05) compared to the initial values. By the 60th day, there was an increase in the level of hemoglobin index up to 126.12±9.10 g/l.

Background & Aims Intrahepatic cholestasis of pregnancy (ICP) is associated with an increased risk of stillbirth. This study aimed to assess the relationship between bile acid concentrations and fetal cardiac dysfunction in patients with ICP who were or were not treated with ursodeoxycholic acid (UDCA). Methods Bile acid profiles and NT-proBNP, a marker of ventricular dysfunction, were assayed in umbilical venous serum from 15 controls and 76 ICP cases (36 untreated, 40 UDCA-treated). Fetal electrocardiogram traces were obtained from 43 controls and 48 ICP cases (26 untreated, 22 UDCA-treated). PR interval length and heart rate variability (HRV) parameters were measured in 2 behavioral states (quiet and active sleep). Results In untreated ICP, fetal total serum bile acid (TSBA) concentrations (r = 0.49, p = 0.019), hydrophobicity index (r = 0.20, p = 0.039), glycocholate concentrations (r = 0.56, p = 0.007) and taurocholate concentrations (r = 0.44, p = 0.039) positively correlated with fetal NT-proBNP. Maternal TSBA (r = 0.40, p = 0.026) and alanine aminotransferase (r = 0.40, p = 0.046) also positively correlated with fetal NT-proBNP. There were no significant correlations between maternal or fetal serum bile acid concentrations and fetal HRV parameters or NT-proBNP concentrations in the UDCA-treated cohort. Fetal PR interval length positively correlated with maternal TSBA in untreated (r = 0.46, p = 0.027) and UDCA-treated ICP (r = 0.54, p = 0.026). Measures of HRV in active sleep and quiet sleep were significantly higher in untreated ICP cases than controls. HRV values in UDCA-treated cases did not differ from controls. Conclusions Elevated fetal and maternal serum bile acid concentrations in untreated ICP are associated with an abnormal fetal cardiac phenotype characterized by increased NT-proBNP concentration, PR interval length and HRV. UDCA treatment partially attenuates this phenotype. Lay summary The risk of stillbirth in intrahepatic cholestasis of pregnancy (ICP) is linked to the level of bile acids in the mother which are thought to disrupt the baby’s heart rhythm. We found that babies of women with untreated ICP have abnormally functioning hearts compared to those without ICP, and the degree of abnormality is closely linked to the level of harmful bile acids in the mother and baby’s blood. Babies of women with ICP who received treatment with the drug UDCA do not have the same level of abnormality in their hearts, suggesting that UDCA could be a beneficial treatment in some ICP cases, although further clinical trials are needed to confirm this., Graphical abstract, Highlights • ICP is associated with an abnormal fetal cardiac phenotype. • Phenotype includes increased PR interval, heart rate variability and NT-proBNP level. • Degree of abnormality is associated with fetal and maternal total serum bile acid levels. • NT-proBNP level in particular is associated with fetal bile acid hydrophobicity index. • UDCA treatment partially ameliorates this phenotype.

Background The effectiveness and safety of colonoscopy are directly dependent on the quality of bowel preparation. Multiple risk factors for inadequate bowel preparation (IBP) have been identified; however, IBP is still reported in 20-30% of cases in most studies. We aimed to identify modifiable predictors of the adequacy of bowel preparation using sodium picosulfate, and to recommend easily modifiable parameters to increase the success rate of colonoscopies. Methods This was a single-center observational study of adult outpatients referred for an elective colonoscopy. Patients were interviewed prior to colonoscopy; volume of liquids consumed was calculated as number of 200-mL cups showed to the patient. Additional information, including medical history, diagnoses and regular medications, was procured from patients’ medical records. Univariate and multivariate regression analyses were performed to identify factors significantly associated with IBP in a subgroup analysis of high-risk patients. Results The rate of IBP in 1172 subjects was 19.4%. This rate decreased as fluid consumption increased, with a further drop associated with shorter intervals from end of preparation to colonoscopy. Drinking < 1.4 L significantly increased the risk of IBP (odds ratio [OR] 3.62, 95% confidence interval [CI] 2.65-4.95), while drinking ≥2 L was associated with adequate preparation (OR 0.09, 95%CI 0-0.42). These associations were stronger in high-risk individuals. Conclusion Greater fluid intake and short interval to colonoscopy are easily modifiable parameters that can substantially reduce the rate of IBP, especially among high-risk individuals.

The ability to differentiate induced-pluripotent stem cells into cardiomyocytes (iPSC-CMs) has opened up novel avenues for potential cardiac therapies. However, iPSC-CMs exhibit a range of somewhat immature functional properties. This study explored the development of the beta-adrenergic receptor (&beta, AR) pathway, which is crucial in regulating contraction and signifying the health and maturity of myocytes. We explored the compartmentation of &beta, 2AR-signalling and phosphodiesterases (PDEs) in caveolae, as functional nanodomains supporting the mature phenotype. F&ouml, rster Resonance Energy Transfer (FRET) microscopy was used to study the cyclic adenosine monophosphate (cAMP) levels in iPSC-CMs at day 30, 60, and 90 following &beta, AR subtype-specific stimulation. Subsequently, the PDE2, PDE3, and PDE4 activity was investigated using specific inhibitors. Cells were treated with methyl-&beta, cyclodextrin (M&beta, CD) to remove cholesterol as a method of decompartmentalising &beta, 2AR. As iPSC-CMs mature with a prolonged culture time, the caveolae density is increased, leading to a reduction in the overall cytoplasmic cAMP signal stimulated through &beta, 2AR (but not &beta, 1AR). Pan-phosphodiesterase inhibition or caveolae depletion leads to an increase in the &beta, 2AR-stimulated cytoplasmic cAMP. Moreover, with time in culture, the increase in the &beta, AR-dependent cytoplasmic cAMP becomes more sensitive to cholesterol removal. The regulation of the &beta, 2AR response by PDE2 and 4 is similarly increased with the time in culture. We conclude that both the &beta, 2AR and PDEs are restricted to the caveolae nanodomains, and thereby exhibit a tighter spatial restriction over the cAMP signal in late-stage compared to early iPSC-CMs.

Background The overall risk of postcontrast acute kidney injury (PC-AKI) after computerized tomography (CT) is negligible, likely because of the small volume of injected iodinated contrast media required. However, the safety of contrast media-enhanced CT in patients with advanced renal functional impairment, an established major risk factor for PC-AKI, is unknown. Materials and methods This is a retrospective study using large data analysis of hospitalized patients at a single center. Adults undergoing CT or magnetic resonance imaging were included in the study and were stratified by estimated glomerular filtration rate (eGFR) (≤30 or >30 mL/min/1.73 m) and by either contrast-enhanced or nonenhanced imaging. Only patients with serial determination of creatinine before and after imaging were included. Demographic, clinical, and laboratory data between groups were analyzed and compared using univariate analysis, propensity score matching, and multivariate logistic regression analysis. Results A total of 22,319 imaging studies were included. Patients with an eGFR of 30 mL/min/1.73 m or lower undergoing contrast-enhanced CT (n = 403) had an increased risk to develop PC-AKI than did similar patients undergoing enhanced or nonenhanced magnetic resonance imaging (n = 96) or nonenhanced CT (n = 1576) or patients undergoing contrast-enhanced CT with a preprocedural eGFR higher than 30 mL/min/1.73 m (n = 9173). These findings remained robust after propensity matching for demographic, procedural, and clinical parameters. Multivariate regression analysis of all patients undergoing CT with preimaging eGFR of 30 mL/min or lower (n = 1979) revealed that iodine-based contrast enhancement increased the likelihood of post-CT AKI by 51% (confidence interval, 1.23-2.05). Conclusion Although radiocontrast-enhanced CT is considered safe in most hospitalized patients and in ambulatory settings, the risk of PC-AKI remains significant among inpatients with substantial preimaging renal functional impairment. Caution is warranted using iodine-based enhanced CT in hospitalized patients with an eGFR of 30 mL/min/1.73 m or lower.

Multiple intra-cellular signalling pathways rely on calcium and 3′–5′ cyclic adenosine monophosphate (cAMP) to act as secondary messengers. This is especially true in cardiomyocytes which act as the force-producing units of the cardiac muscle and are required to react rapidly to environmental stimuli. The specificity of functional responses within cardiomyocytes and other cell types is produced by the organellar compartmentation of both calcium and cAMP. In this review, we assess the role of molecular localisation and relative contribution of active and passive processes in producing compartmentation. Active processes comprise the creation and destruction of signals, whereas passive processes comprise the release or sequestration of signals. Cardiomyocytes display a highly articulated membrane structure which displays significant cell-to-cell variability. Special attention is paid to the way in which cell membrane caveolae and the transverse-axial tubule system allow molecular localisation. We explore the effects of cell maturation, pathology and regional differences in the organisation of these processes. The subject of signal compartmentation has had a significant amount of attention within the cardiovascular field and has undergone a revolution over the past two decades. Advances in the area have been driven by molecular imaging using fluorescent dyes and genetically encoded constructs based upon fluorescent proteins. We also explore the use of scanning probe microscopy in the area. These techniques allow the analysis of molecular compartmentation within specific organellar compartments which gives researchers an entirely new perspective.

Cardiomyocyte β3-adrenoceptors (β3-ARs) coupled to soluble guanylyl cyclase (sGC)-dependent production of the second messenger 3’,5’-cyclic guanosine monophosphate (cGMP) have been shown to protect from heart failure. However, the exact localization of these receptors to fine membrane structures and subcellular compartmentation of β3-AR/cGMP signals underpinning this protection in health and disease remain elusive. Here, we used a Förster Resonance Energy Transfer (FRET)-based cGMP biosensor combined with scanning ion conductance microscopy (SICM) to show that functional β3-ARs are mostly confined to the T-tubules of healthy rat cardiomyocytes. Heart failure, induced via myocardial infarction, causes a decrease of the cGMP levels generated by these receptors and a change of subcellular cGMP compartmentation. Furthermore, attenuated cGMP signals led to impaired phosphodiesterase two dependent negative cGMP-to-cAMP cross-talk. In conclusion, topographic and functional reorganization of the β3-AR/cGMP signalosome happens in heart failure and should be considered when designing new therapies acting via this receptor.

Additional bands have been discovered for the first time in the Raman spectra of terbium doped lithium niobate crystals. The bands have been determined in the high-frequency region and have been attributed to the overtone states of the second order of polar fundamental modes of the crystal lattice. It has been established that Raman spectrum of terbium doped lithium niobate contains bands with frequencies exceeding the overtones of the highest-frequency fundamental polar modes of A1(Z) and E(X, Y) symmetry types. The observed features of the second-order Raman spectra have been interpreted as a manifestation of bound states of phonons – biphonons.

The excitation of an aqueous solution of uranyl chloride by a 410-nm semiconductor LED and 266- and 448-nm lasers is found to induce intense photoluminescence: several bands in the blue-green spectral range (494 to 565 nm). Upon excitation of uranyl chloride aqueous solution by a 468-nm LED, the photoluminescence spectrum is a relatively narrow strong band peaking at 508 nm, which was interpreted as the transition from spontaneous photoluminescence to superluminescence. A lasing scheme (similar to that for dye lasers) has been proposed.

We have studied the optical properties of copper-doped lithium niobate crystals using semiconductor light-emitting diodes and lasers emitting in the visible and ultraviolet spectral regions as excitation sources. The results demonstrate that, at an excitation frequency approaching the frequency of electronic absorption in copper ions, there is discrete resonance Raman scattering in the form of a frequency comb. The observed Raman satellites of discrete light scattering are due to polar longitudinal A1 optical modes of the lithium niobate single crystal. Under excitation by a light-emitting diode with a wavelength of 520 nm, we observe a sharp increase in discrete light scattering intensity in comparison with the photoluminescence excited by shorter wavelength excitation sources.

Experiments on IR Fourier spectrometry of a Nafion polymer membrane swollen in water are described. The dynamics of Nafion swelling is studied in relation to the deuterium content in water. It has turned out that, if the polymer swells in waters with different deuterium contents, a considerable confinement effect is observed, which, in this case, manifests itself in that the transmittance of IR radiation of water that is enclosed within a region with a size of ~100 μm differs from that of water that is inside nanometer pores of the polymer membrane. In addition, the transmittance of Nafion swollen in water measured at a wavelength of λ = 1.92 μm (spectral minimum) experiences a local minimum in the deuterium concentration range 102 < C < 103 ppm, irrespective of the soaking time of the polymer in deuterated water. Finally, the effect of the deuterium substitution of the residual water present in the volume of the membrane has been revealed.

We have measured photoluminescence spectra of an aqueous uranyl chloride solution under excitation by various light sources: semiconductor light-emitting diodes and cw laser. The excitation wavelength lay within a resonance absorption band of uranyl chloride, which ensured photoluminescence detection at exposure times of 10–3 s using an extremely small volume of the substance (10–9 cm3). The photoluminescence spectra were measured using a small minispectrometer, which allowed us to analyze the spectra in the range 200–1000 nm.

The ecto-nucleotide pyrophosphatase/phosphodiesterase (NPP) enzyme family modulates purinergic signaling by degrading extracellular nucleotides. CD203c (NPP3, ENPP3) regulates the inflammatory response of basophils via ATP hydrolysis and is a marker for allergen sensitivity on the surface of these cells. Multiple other roles and substrates have also been proposed for this protein. In order to gain insight into its molecular functions, we determined the crystal structure of human NPP3 as well as its complex with an ATP analog. The enzyme exhibits little preference for nucleobase type, and forms specific contacts with the alpha and beta phosphate groups of its ligands. Dimerization of the protein does not affect its catalytic activity. These findings expand our understanding of substrate recognition within the NPP family. Database Structural data are available in the Protein Data Bank under the accession numbers 6C01 (human NPP3) and 6C02 (human NPP3 T205A N594S with AMPCPP).

The photoluminescence (PL) of copper-doped lithium niobate single crystals is studied using different UV–Vis light-emitting diodes and a pulse-periodic laser with a wavelength of 266 nm as excitation radiation sources. With the resonance excitation from a 527-nm light-emitting diode, the intensity of PL increases sharply (by two orders of magnitude). When using a 467-nm light-emitting diode for excitation, the PL spectrum is characterized by the presence of multiphonon lines in the range of 520–620 nm.

Acid ceramidase (aCDase, ASAH1) hydrolyzes lysosomal membrane ceramide into sphingosine, the backbone of all sphingolipids, to regulate many cellular processes. Abnormal function of aCDase leads to Farber disease, spinal muscular atrophy with progressive myoclonic epilepsy, and is associated with Alzheimer’s, diabetes, and cancer. Here, we present crystal structures of mammalian aCDases in both proenzyme and autocleaved forms. In the proenzyme, the catalytic center is buried and protected from solvent. Autocleavage triggers a conformational change exposing a hydrophobic channel leading to the active site. Substrate modeling suggests distinct catalytic mechanisms for substrate hydrolysis versus autocleavage. A hydrophobic surface surrounding the substrate binding channel appears to be a site of membrane attachment where the enzyme accepts substrates facilitated by the accessory protein, saposin-D. Structural mapping of disease mutations reveals that most would destabilize the protein fold. These results will inform the rational design of aCDase inhibitors and recombinant aCDase for disease therapeutics., Acid ceramidase (aCDase) hydrolyzes lysosomal membrane ceramide into sphingosine and its dysfunction leads to a variety of disease phenotypes. Here, the authors present structures of aCDase in its proenzyme and autocleaved forms, which provides insight into its mechanism of action.

The possibility of covalent fixing of hydroxyl-containing photochromic compounds on the surface of polyurethane films containing excess isocyanate groups was studied. By comparing the spectral-kinetic characteristics of polyurethane films treated with solutions and films with chromene or spirooxazine derivatives introduced into the bulk polymer, it was concluded that in the first case the polymer swells and the photochromic compound becomes distributed predominantly in the bulk polymer rather than on the surface.

The evolution of Raman spectra in a wide range of temperatures that includes the ferroelectric transition point in lithium niobate single crystals is studied for polarization geometry X(ZZ)Y. In this geometry, the soft mode responsible for the phase transition distinguished by 1A1(TO)-type symmetry should appear in the spectra. Experimental studies show that the 1A1(TO) mode interacts resonantly with nonfundamental modes in the low-frequency region of the spectrum. Near the ferroelectric phase transition point, an isofrequency opalescence effect is observed that consists of an abrupt increase in Raman signal intensity at fixed frequencies near the excitation line.

Optical properties of a one-dimensional photonic-crystal film with a lattice period of ≈380 nm formed by electrochemical etching of an aluminum foil are investigated. Experimental data on the spectra of transmission and reflection in the region of the first, second, and third stop bands of anodic photonic crystal of aluminum oxide are compared with a theoretical dependence obtained from the well-known dispersion relation. The possibility of creating selective narrow-band optical filters based on mesoporous one-dimensional photonic crystals is analyzed. The conditions of enhancement of an electromagnetic field of laser radiation at 532 nm under normal incidence on a photonic-crystal surface are established. The possibility of generation of optical harmonics under the conditions of sharp increase in the effective field of the driving radiation in a mesoporous photonic crystal of anodic aluminum oxide filled with lithium iodate is analyzed.

A method for rapid identification of uranyl compounds based on resonance fiber-optic photoluminescence (PL) excitation by ultraviolet-laser or LED radiation is proposed. This method was used to measure the PL spectra of an extremely small volume (10–9 cm3) of crystalline uranyl acetate dehydrate UO2(CH3COO)2 ∙ 2H2O with an exposure of 10–3 s. Semiconductor LEDs with wavelengths of 369, 385, 410, and 466 nm and a repetitively pulsed nitrogen laser with a lasing wavelength of 337 nm served as sources of excitation radiation. The operating range of a small-sized minispectrometer used in these experiments was 200–1000 nm.

For the first time, stimulated Raman scattering is detected in microcrystalline powder of barium nitrate under excitation by ultrashort (60 ps) pulses of a YAG:Nd3+ laser operated at a wavelength of 532 nm. First and second Stokes components with a frequency shift of 1047 cm−1 are observed in the stimulated Raman scattering spectrum of the powder. Spectra observed in the microcrystalline powder were juxtaposed with the corresponding spectra of spontaneous and stimulated Raman scattering in a Ba(NO3)2 single crystal. The studies performed open the possibility for creating lasers based on stimulated Raman scattering in microcrystalline powders of inorganic compounds with various molecular groups.

Pigment Red 53:2 (P R.53:2), the calcium lake of P.R.53, in its γ-phase is a bright orange pigment suitable for printing applications and for the colouration of seeds. The γ-phase forms needle-like, long thin crystals, which are often bent, as seen by transmission electron microscopy (TEM). Its crystal structure was determined from synchrotron X-ray powder diffraction data supported by lattice-energy minimisations with dispersion-corrected density functional theory (DFT+D). The γ-phase is a dihydrate with the chemical composition Ca(C17H12ClN2O4S)2 · 2H2O. The calcium ion is coordinated by seven oxygen atoms, which come from the sulfonate groups of four anions, one carbonyl group and two water molecules. The structure contains columns which are built by the Ca2+ ions, the water molecules, and the pigment anions, with their sulfonate and carbonyl groups directed inward, and their non-polar phenyl and naphthalene groups pointing outwards. All columns are parallel. Neighbouring columns are connected by van der Waals forces only. This explains the observed bent hair-like morphology of the crystals.

The effect of UV irradiation of the surface of a Nafion polymer electrolyte membrane swollen in water in the pump grazing incidence geometry has been experimentally investigated. The photoluminescence from the Nafion surface has been measured in the spectral range characteristic of this polymer. The photoluminescence signal from a polymer with a variable isotopic composition is found to be sensitive to swelling in water. The spectral absorption lines of dry and water-swollen Nafion samples are characterized. It is shown that the luminescence centers in the polymer are sulfonic acid groups located on the ends of perfluorovinyl ether groups, which form the teflon base. Measurements of the temporal dynamics of the luminescence of these groups have revealed an informationally important and significant dependence of the luminescence parameters on the degree of Nafion swelling. A pronounced and nontrivial dependence of these parameters on the content of heavy isotope D2O in water is also found.

A technique of probe photoluminescence and Raman spectroscopy has been developed. This technique makes it possible to detect small (10−6 to 10−8 g) amounts of uranyl compounds at short exposure times (1−10 s). The photoluminescence spectra of Na[UO2CH3(COO)3] polycrystals recorded upon excitation by short-wavelength radiation of LEDs and lasers are found to contain equidistant bands with a shift of 854 cm−1, which corresponds to the frequency of totally symmetric uranyl vibration also manifesting itself in Raman spectra.

Procedure was developed for surface dyeing of polycarbonate glass with photochromic thermally relaxing compounds from the classes of spiropyrans, spirooxazines, and chromenes via diffusion of photochromic molecules from solutions in cyclohexanone. It was shown that the highest diffusion efficiency of photochromic compounds without loss of the optical surface quality of polycarbonate glass is reached at a temperature of 80°C. Samples of photochromic polycarbonate glasses were obtained and their photochromic properties were studied.