Репозиторий Университета

Background: The aim of this paper was to systematically review the root canal configuration (RCC) and morphology literature of the mandibular second premolar (Mn2P). Methods: Systematic research of five electronic databases was performed to identify published literature concerning the root canal configuration (RCC) of the Mn2P up through July 2020. Studies were selected according to predefined search terms and keywords inclusion criteria: “root canal configuration”, “root canal system”, “root canal morphology”, “mandibular second premolar”, “mandibular premolars”, “morphology” and “anatomy”. Further possible studies were identified by cross-referencing and screening the bibliographies of the selected articles. Results: From 1622 retrieved studies, 44 studies investigating the internal morphology of 17,839 Mn2Ps were included. Most examined Mn2Ps were single-rooted (89.5–100%); two-rooted (0.1–8%) and three-rooted (0.1–3.5%) Mn2Ps at lower frequency. Most frequent RCCs reported were 1–1–1/1 (55.3–99.6%) followed by 1–1–2/2 (0.5–57%) and 2–2–2/2 (0.6–18%). The meta-analysis of seven studies demonstrated that a significantly higher number of RCC type 1–2–1/1 (OR [95%CI] = 2.05 [1.27, 3.33]) and 2–2–2/2 (OR [95%CI] = 2.32 [0.65, 8.63]) were observed in male than in female patients. Conclusions: Different RCC research methods have been reported. Whereas clearing and radiographs were commonly used in the past, CBCT has been prevalent in recent years. A globally high frequency of a 1–1–1/1 RCC in the Mn2P has been reported. Nevertheless, the probability that different, more complicated RCCs can appear in Mn2Ps should not be underestimated and, thus, should be taken into consideration when making decisions during an endodontic treatment.

Background: The existing data demonstrate the potential role of trace elements in nasal mucociliary clearance, although the association between trace element and mineral status and ciliary function in children with chronic rhinosinusitis is insufficiently studied. Therefore, the objective of the present study is evaluation of trace element and mineral status and mucociliary function in pediatric CRS patients before and after functional endoscopic sinus surgery. Methods: The present study involved 30 children with chronic rhinosinusitis without nasal polyps. During this follow-up the patients were examined preoperatively (point 0), underwent functional endoscopic sinus surgery, and were repeatedly examined at three months postoperatively (point 1). At both points the patients were subjected to quality-of-life assessment using SNOT-20 questionnaire; endoscopic and computer tomography examination of the nasal sinuses; evaluation of ciliary function and mucosal cytology using high-speed videomicroscopy; assessment of blood count and inflammatory markers; as well as analysis of trace element and mineral levels in whole blood, serum, and hair using inductively-coupled plasma mass-spectrometry. Results: The obtained data demonstrate that endoscopic sinus surgery significantly improved sinonasal pathology in children with chronic rhinosinusitis, as evidenced by significantly reduced Lund-Mackay, Lund-Kennedy, and SNOT-20 scores. At the same time, no significant improvement of ciliary functions or mucosal cytology was observed postoperatively. Trace element status assessment demonstrated that postoperative serum Zn, whole blood Mg and Cu were significantly lower as compared to preoperative values. In contrast, serum Mn and Cr, as well as whole blood Cr and hair Se were characterized by a significant increase at three months postoperatively. Multiple linear regression analysis demonstrated that serum Zn is significantly associated with the number of ciliated cells and cell viability, whereas serum Mn and whole blood Cu concentrations are inversely associated with cell viability and ciliary length, respectively. Hair Se was found to be associated with the number of neutrophils in the mucosa biopsy. Conclusion: Redistribution of trace elements and minerals may at least partially mediate prolonged recovery of mucosal ciliary function in children with chronic rhinosinusitis in three months after functional sinus surgery, although the particular mechanisms of these alterations in trace element levels are to be discovered.

Background: The existing data demonstrate the potential role of trace elements in nasal mucociliary clearance, although the association between trace element and mineral status and ciliary function in children with chronic rhinosinusitis is insufficiently studied. Therefore, the objective of the present study is evaluation of trace element and mineral status and mucociliary function in pediatric CRS patients before and after functional endoscopic sinus surgery. Methods: The present study involved 30 children with chronic rhinosinusitis without nasal polyps. During this follow-up the patients were examined preoperatively (point 0), underwent functional endoscopic sinus surgery, and were repeatedly examined at three months postoperatively (point 1). At both points the patients were subjected to quality-of-life assessment using SNOT-20 questionnaire; endoscopic and computer tomography examination of the nasal sinuses; evaluation of ciliary function and mucosal cytology using high-speed videomicroscopy; assessment of blood count and inflammatory markers; as well as analysis of trace element and mineral levels in whole blood, serum, and hair using inductively-coupled plasma mass-spectrometry. Results: The obtained data demonstrate that endoscopic sinus surgery significantly improved sinonasal pathology in children with chronic rhinosinusitis, as evidenced by significantly reduced Lund-Mackay, Lund-Kennedy, and SNOT-20 scores. At the same time, no significant improvement of ciliary functions or mucosal cytology was observed postoperatively. Trace element status assessment demonstrated that postoperative serum Zn, whole blood Mg and Cu were significantly lower as compared to preoperative values. In contrast, serum Mn and Cr, as well as whole blood Cr and hair Se were characterized by a significant increase at three months postoperatively. Multiple linear regression analysis demonstrated that serum Zn is significantly associated with the number of ciliated cells and cell viability, whereas serum Mn and whole blood Cu concentrations are inversely associated with cell viability and ciliary length, respectively. Hair Se was found to be associated with the number of neutrophils in the mucosa biopsy. Conclusion: Redistribution of trace elements and minerals may at least partially mediate prolonged recovery of mucosal ciliary function in children with chronic rhinosinusitis in three months after functional sinus surgery, although the particular mechanisms of these alterations in trace element levels are to be discovered.

Recently, mesenchymal stem/stromal cells (MSCs) due to their pro-angiogenic, anti-apoptotic, and immunoregulatory competencies along with fewer ethical issues are presented as a rational strategy for regenerative medicine. Current reports have signified that the pleiotropic effects of MSCs are not related to their differentiation potentials, but rather are exerted through the release of soluble paracrine molecules. Being nano-sized, non-toxic, biocompatible, barely immunogenic, and owning targeting capability and organotropism, exosomes are considered nanocarriers for their possible use in diagnosis and therapy. Exosomes convey functional molecules such as long non-coding RNAs (lncRNAs) and micro-RNAs (miRNAs), proteins (e.g., chemokine and cytokine), and lipids from MSCs to the target cells. They participate in intercellular interaction procedures and enable the repair of damaged or diseased tissues and organs. Findings have evidenced that exosomes alone are liable for the beneficial influences of MSCs in a myriad of experimental models, suggesting that MSC- exosomes can be utilized to establish a novel cell-free therapeutic strategy for the treatment of varied human disorders, encompassing myocardial infarction (MI), CNS-related disorders, musculoskeletal disorders (e.g. arthritis), kidney diseases, liver diseases, lung diseases, as well as cutaneous wounds. Importantly, compared with MSCs, MSC- exosomes serve more steady entities and reduced safety risks concerning the injection of live cells, such as microvasculature occlusion risk. In the current review, we will discuss the therapeutic potential of MSC- exosomes as an innovative approach in the context of regenerative medicine and highlight the recent knowledge on MSC- exosomes in translational medicine, focusing on in vivo researches.

Recently, mesenchymal stem/stromal cells (MSCs) due to their pro-angiogenic, anti-apoptotic, and immunoregulatory competencies along with fewer ethical issues are presented as a rational strategy for regenerative medicine. Current reports have signified that the pleiotropic effects of MSCs are not related to their differentiation potentials, but rather are exerted through the release of soluble paracrine molecules. Being nano-sized, non-toxic, biocompatible, barely immunogenic, and owning targeting capability and organotropism, exosomes are considered nanocarriers for their possible use in diagnosis and therapy. Exosomes convey functional molecules such as long non-coding RNAs (lncRNAs) and micro-RNAs (miRNAs), proteins (e.g., chemokine and cytokine), and lipids from MSCs to the target cells. They participate in intercellular interaction procedures and enable the repair of damaged or diseased tissues and organs. Findings have evidenced that exosomes alone are liable for the beneficial influences of MSCs in a myriad of experimental models, suggesting that MSC- exosomes can be utilized to establish a novel cell-free therapeutic strategy for the treatment of varied human disorders, encompassing myocardial infarction (MI), CNS-related disorders, musculoskeletal disorders (e.g. arthritis), kidney diseases, liver diseases, lung diseases, as well as cutaneous wounds. Importantly, compared with MSCs, MSC- exosomes serve more steady entities and reduced safety risks concerning the injection of live cells, such as microvasculature occlusion risk. In the current review, we will discuss the therapeutic potential of MSC- exosomes as an innovative approach in the context of regenerative medicine and highlight the recent knowledge on MSC- exosomes in translational medicine, focusing on in vivo researches.

In countries where headache services exist at all, their focus is usually on specialist (tertiary) care. This is clinically and economically inappropriate: most headache disorders can effectively and more efficiently (and at lower cost) be treated in educationally supported primary care. At the same time, compartmentalizing divisions between primary, secondary and tertiary care in many health-care systems create multiple inefficiencies, confronting patients attempting to navigate these levels (the “patient journey”) with perplexing obstacles. High demand for headache care, estimated here in a needs-assessment exercise, is the biggest of the challenges to reform. It is also the principal reason why reform is necessary. The structured headache services model presented here by experts from all world regions on behalf of the Global Campaign against Headache is the suggested health-care solution to headache. It develops and refines previous proposals, responding to the challenge of high demand by basing headache services in primary care, with two supporting arguments. First, only primary care can deliver headache services equitably to the large numbers of people needing it. Second, with educational supports, they can do so effectively to most of these people. The model calls for vertical integration between care levels (primary, secondary and tertiary), and protection of the more advanced levels for the minority of patients who need them. At the same time, it is amenable to horizontal integration with other care services. It is adaptable according to the broader national or regional health services in which headache services should be embedded. It is, according to evidence and argument presented, an efficient and cost-effective model, but these are claims to be tested in formal economic analyses.

Background: Risky sexual behaviour (RSB) is regarded as a major health problem during adolescence. Russia has one of the highest rates of teenage pregnancy, abortion and newly diagnosed HIV infections in the world, but research on RSB in Russian youth has been limited. To address this deficit, this study examined the role of several factors, including internalizing and externalizing symptoms, in RSB among Russian adolescents. Methods: Self-reported data were collected from 2573 Russian adolescents aged 13–17 years old (59.4 % girls; Mean age = 14.89) regarding RSB (unprotected sex, early pregnancy, multiple sexual partners and substance use during sexual encounters). Information was also obtained on externalizing (conduct problems and delinquent behaviour) and internalizing (depression, anxiety and posttraumatic stress) symptoms, as well as interpersonal risk and protective factors (affiliation with delinquent peers, parental involvement and teacher support). Hierarchical multiple binary logistic regression analysis was used to examine the associations between these variables and RSB. Results: Boys reported engaging in more RSB than girls. Externalizing symptoms and affiliation with delinquent peers were most strongly associated with RSB, whereas symptoms of anxiety were negatively associated with RSB. There was an interaction effect for sex and affiliation with delinquent peers on RSB with boys reporting RSB when having more delinquent peers. Neither parental involvement nor teacher support were protective against RSB. Conclusions: Early detection of and interventions for RSB and associated externalizing symptoms may be important for adolescent physical and mental wellbeing. Affiliation with delinquent peers should, especially among boys, be regarded as a risk marker for RSB.

Background: Risky sexual behaviour (RSB) is regarded as a major health problem during adolescence. Russia has one of the highest rates of teenage pregnancy, abortion and newly diagnosed HIV infections in the world, but research on RSB in Russian youth has been limited. To address this deficit, this study examined the role of several factors, including internalizing and externalizing symptoms, in RSB among Russian adolescents. Methods: Self-reported data were collected from 2573 Russian adolescents aged 13–17 years old (59.4 % girls; Mean age = 14.89) regarding RSB (unprotected sex, early pregnancy, multiple sexual partners and substance use during sexual encounters). Information was also obtained on externalizing (conduct problems and delinquent behaviour) and internalizing (depression, anxiety and posttraumatic stress) symptoms, as well as interpersonal risk and protective factors (affiliation with delinquent peers, parental involvement and teacher support). Hierarchical multiple binary logistic regression analysis was used to examine the associations between these variables and RSB. Results: Boys reported engaging in more RSB than girls. Externalizing symptoms and affiliation with delinquent peers were most strongly associated with RSB, whereas symptoms of anxiety were negatively associated with RSB. There was an interaction effect for sex and affiliation with delinquent peers on RSB with boys reporting RSB when having more delinquent peers. Neither parental involvement nor teacher support were protective against RSB. Conclusions: Early detection of and interventions for RSB and associated externalizing symptoms may be important for adolescent physical and mental wellbeing. Affiliation with delinquent peers should, especially among boys, be regarded as a risk marker for RSB.

A correlation between the crystal structure and magnetic properties of system (1-x)BiFeO3 – (x)BaTiO3 with compounds across the morphotropic phase boundary was studied using X-ray and neutron diffraction, magnetometry, and Mössbauer spectroscopy measurements. Increase in the dopants content leads to the structural transition from the rhombohedral phase to the cubic phase via a formation of the two-phase region (0.2 < x < 0.33), wherein the magnetic structure changes from the modulated G-type antiferromagnetic to the collinear antiferromagnetic via a stabilization of the non-collinear antiferromagnetic phase with non-zero remanent magnetization. The value of magnetic moment calculated per iron ion based on the Mössbauer and neutron diffraction data decreases from m ≈ 4.4 μB for the compound with x = 0.25 to m = 3.2 μB for the compound with x = 0.35 testifying a dominance of 3 + oxidation state of the iron ions. Increase in the amount of the cubic phase leads to a reduction in the remanent magnetization from 0.02 emu/g for the compounds with the dominant rhombohedral phase (x < 0.27) down to about 0.001 emu/g for the compounds with dominant cubic structure (x ≥ 0.27). Rapid decrease in the remanent magnetization observed in the compounds across the phase coexistence region points at no direct correlation between the type of structural distortion and non-zero remanent magnetization, while the oxygen octahedra tilting is the key factor determining the presence of non-zero remanent magnetization.

© 1995-2012 IEEE. In this review, we discuss the crucial role of cranial and the extracranial lymphatics in keeping the central nervous system (CNS) health. We talk about the important lymphatic mechanism of removal of metabolites and toxins from the brain, which orchestrates the regenerative processes in CNS. We debate a novel knowledge about the lymphatic mechanism responsible for maintaining the balance between the exit and the entrance of molecules and cells from and into CNS. Finally, we highlight the pioneering technologies of biophotonic stimulation of lymphatic drainage function that can open a new era for the development of novel bedside, readily applicable and commercially viable technologies for the treatment of brain diseases.

© 1995-2012 IEEE. In this review, we discuss the crucial role of cranial and the extracranial lymphatics in keeping the central nervous system (CNS) health. We talk about the important lymphatic mechanism of removal of metabolites and toxins from the brain, which orchestrates the regenerative processes in CNS. We debate a novel knowledge about the lymphatic mechanism responsible for maintaining the balance between the exit and the entrance of molecules and cells from and into CNS. Finally, we highlight the pioneering technologies of biophotonic stimulation of lymphatic drainage function that can open a new era for the development of novel bedside, readily applicable and commercially viable technologies for the treatment of brain diseases.

© 1995-2012 IEEE. In this review, we discuss the crucial role of cranial and the extracranial lymphatics in keeping the central nervous system (CNS) health. We talk about the important lymphatic mechanism of removal of metabolites and toxins from the brain, which orchestrates the regenerative processes in CNS. We debate a novel knowledge about the lymphatic mechanism responsible for maintaining the balance between the exit and the entrance of molecules and cells from and into CNS. Finally, we highlight the pioneering technologies of biophotonic stimulation of lymphatic drainage function that can open a new era for the development of novel bedside, readily applicable and commercially viable technologies for the treatment of brain diseases.

© 2021 Elsevier Ltd Objectives: Metabolic syndrome (MetS) and its components (high blood pressure, BMI≥30, altered fasting glucose, low HDL cholesterol and high triglycerides) may undermine early perioperative outcomes after radical prostatectomy (RP). We tested this hypothesis. Materials & methods: Within the National Inpatient Sample database (2008–2015) we identified RP patients. The effect of MetS was tested in four separate univariable analyses, as well as in multivariable regression models predicting: 1) overall complications, 2) length of stay, 3) total hospital charges and 4) non-home based discharge. All models were weighted and adjusted for clustering, as well as all available patient and hospital characteristics. Results: Of 91,618 patients: 1) 50.2% had high blood pressure, 2) 8.0% had BMI≥30, 3) 13.0% had altered fasting glucose, 4) 22.8% had high triglycerides and 5) 0.03% had low HDL cholesterol. Respectively, one vs. two vs. three vs. four MetS components were recorded in 36.2% vs. 19.0% vs. 5.5% vs. 0.8% patients. Of all patients, 6.3% exhibited ≥3 components and qualified for MetS diagnosis. The rates of MetS increased over time (EAPC:+9.8%; p < 0.001). All four tested MetS components (high blood pressure, BMI≥30, altered fasting glucose and high triglycerides) achieved independent predictor status in all four examined endpoints. Moreover, a highly statistically significant dose-response was also confirmed for all four tested endpoints. Conclusion: MetS and its components consistently and strongly predict early adverse outcomes after RP. Moreover, the strength of the effect was directly proportional to the number of MetS components exhibited by each individual patient, even if formal MetS diagnosis of ≥3 components has not been met.

© 2020 Elsevier Ltd Background: Grammar includes not only the ability to use verbs but also the ability to express and understand the relationships existing among the words in a sentence. Since the initial description of agrammatism (Kussmaul, 1877) it was proposed that there are two different types of agrammatism: Aktaphasie and Agrammatismus. The first one has been extensively studied, while the second one has been mostly overlooked. Aims: To analyze the brain areas involved in understanding the relationships existing among the words in a sentence. Its disturbances would correspond to the second type of agrammatism. Outcomes & results: Prepositions, adverbs, and grammatical cases are used to indicate the relationships among sentence words. This is a quasi-spatial ability supported by the left posterior parietal lobe. Almost one century ago a type of aphasia referred to as “semantic aphasia”, associated with left posterior parietal damage and characterized by the inability to use and understand the relationships among the language words, was described. Excepting a few papers, this type of aphasia has been usually ignored in the contemporary neuroscience literature. From the historical perspective, it has been proposed that grammar evolved in two steps: (1) proto-grammar, consisting of flat verb-noun compounds, and (2) hierarchical syntax or complex grammar. The first one is associated with the ability to use and understand verbs. The second one can be related to the ability to use verbally mediate spatial concepts. Some recently published cases of semantic aphasia corroborate its clinical manifestations and the locus of pathology. Functional studies support the participation of the left posterior parietal lobe in grammar. Conclusions: It is concluded that evidence suggests that semantic aphasia is a real type of aphasia and indeed there are two grammatical subsystems in the brain and two agrammatic types of aphasia.

© 2021 Mathematical models for complex systems under random fluctuations often certain uncertain parameters. However, quantifying model uncertainty for a stochastic differential equation with an α-stable Lévy process is still lacking. Here, we propose an approach to infer all the uncertain non-Gaussian parameters and other system parameters by minimizing the Hellinger distance over the parameter space. The Hellinger distance measures the similarity between an empirical probability density of non-Gaussian observations and a solution (as a probability density) of the associated nonlocal Fokker-Planck equation. Numerical experiments verify that our method is feasible for estimating single and multiple parameters. Meanwhile, we find an optimal estimation interval of the estimated parameters. This method is beneficial for extracting governing dynamical system models under non-Gaussian fluctuations, as in the study of abrupt climate changes in the Dansgaard-Oeschger events.

© 2021 Elsevier GmbH Background: Ultrasound is a routine procedure performed during pregnancy to monitor the status of the human fetus, including the development of the digestive tract. The aim of this publication was to determine the shape of the fetal sigmoid colon mesentery during the first and second trimester of pregnancy by means of ultrasound. Methods: The study was performed in 45 pregnant women (age: 36.4 years on average, range 25–45) during a routine ultrasound examination. The fetuses were between 12 and 22 weeks of pregnancy. The shape of the fetal sigmoid colon mesentery was analyzed. Results: We visualized the triangular shape of the mesentery in all 45 cases. A prevalence of scalene or isosceles acute triangles was found in both trimesters. At the 12−13 weeks we observed 5 different forms of mesenteric triangles – the scalene or isosceles acute triangles appeared at 33.3% and 28.6%, respectively. The obtuse scalene was present in 23.8 %. In the 2nd trimester (20−22 weeks) 4 types were found, among them 37.5 % acute scalene and 33.3 % acute isosceles. Conclusions: The fetal sigmoid colon mesentery can be visualized from the 12th week of pregnancy. The triangular shape of the sigmoid colon mesentery is easy to follow during routine ultrasound examinations.

© 2021 Elsevier B.V. Innovative Mn-containing glass ceramic (Na2O[2.00]-K2O[0.09]-MgO[3.10]-MnO[2.07]-CaO[38.78]-CaF2[2.25]-P2O5[9.66]-SiO2[41.71] [wt%]) was obtained by sol-gel. It was investigated by High Resolution Field Emission Scanning Electron Microscopy, Energy Dispersive X-Ray Spectroscopy, X-Ray fluorescence, X-Ray Diffraction, and Fourier Transform Infrared Spectroscopy. Ion release characteristics of the glass ceramic powder were quantified via Inductively Coupled Plasma Optical Emission Spectroscopy. Biological tests were performed using equine adipose tissue mesenchymal stem cells (AMSCs). MTT assay demonstrated the cytocompatibility of the prepared material. AMSCs differentiation test showed that the glass ceramic favored the stem cell differentiation in adipogenic, chondrogenic, and osteogenic lineages, the last one being qualitatively more pronounced. The antimicrobial properties were evaluated against Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa, Salmonella typhi, and Staphylococcus aureus bacteria strains and Candida albicans fungus. The inhibition of Gram-negative bacteria (S. tiphy, E. coli), Gram-positive (E. faecalis) and fungus (C. albicans) was detected, while the inhibition of P. aeruginosa and S. aureus was not significant.

© 2021 Elsevier Inc. Methylmercury (MeHg) is a persistent environmental neurotoxicant that may cause adverse neurodevelopmental effects. Previous studies showed that developmental MeHg exposure caused damage to brain functions that were unmasked after a silent period of years or decades. However, the underlying mechanisms of the latent neurotoxicity associated with MeHg exposure from earlier developmental stages have yet to be fully understood. Herein, we established a Caenorhabditis elegans (C. elegans) model of developmental MeHg latent toxicity. Synchronized L1 stage worms were exposed to MeHg (0, 0.05, 0.5 and 5 μM) for 48 h. Swimming moving speeds at adulthood were analyzed in worms exposed to MeHg exposure at early larvae stages. Worms developmentally exposed to MeHg had a significant decline in swimming moving speed on day 10 adult stage, but not on day 1 or 5 adult stage, even though the mercury level in the worms exposed to 0.05 or 0.5 μM MeHg were below the quantification limit on day 10 adult. Day 10 adult worms treated with MeHg showed a significant decrease in bending angle and bending frequency during swimming. Furthermore, their reduced moving speeds tended to increase during the 300-s swimming experiment. Dopamine signaling is known to be involved in the regulation of worms' moving speed. Accordingly, the moving speed of worms with cat-2 (mammalian tyrosine hydroxylase homolog) mutation or dat-1 deletion were assayed on day 10 adult. The cat-2 mutant worms did not show a decline in moving speeds, body bends or bending angles during swimming on day 10 adult stage. Analyses of moving speeds of worms with dat-1 deletion showed that the moving speeds were further reduced after MeHg exposure. However, the effects of MeHg and dat-1 deletion were not synergistic, as the interaction between these parameters did not attain statistical significance. Altogether, our results suggest that developmental MeHg exposure reduced moving speed, and this latent toxicity was less pronounced in the context of deficient production of dopamine synthesis. Tyrosine hydroxylase plays an important role in regulating dopamine-mediated modulation of neurobehavioral functions. These findings uncovered a pivotal role of dopamine and its metabolism in the latent neurotoxic effects of MeHg.

© 2021 Elsevier B.V. Based on a comprehensive theoretical and experimental approach, a low-defect thin film of stable dimeric phthalocyanine zinc complex (bis-[2-hydroxy-9(10),16(17), 23(24)-tri-tert-butylphthalocyanine]zinc – J-[OHPctZn]2) was prepared. It is shown that the dye forms stable amorphous edge-on monolayers at the air/water interface with an insignificant content of cylindrical 3D aggregates. These floating layers keep their structure when transferred by the Langmuir-Schaefer method onto a solid substrate, demonstrating a tendency towards ordered H-aggregation with preserving their linear molecular properties. Mixed two- and three-photon absorption of femtosecond laser pulses (280 fs) was firstly detected on this sample, as well as the ability of a material to the nonlinear attenuation of the intense irradiation, which is important for optical limiting.

© 2020, Tsinghua University Press and Springer-Verlag GmbH Germany, part of Springer Nature. One dimensional (1D) nanostructures attract considerable attention, enabling a broad application owing to their unique properties. However, the precise mechanism of 1D morphology attainment remains a matter of debate. In this study, ultrafast picosecond (ps) laser-induced treatment on upconversion nanoparticles (UCNPs) is offered as a tool for 1D-nanostructures formation. Fragmentation, reshaping through recrystallization process and bioadaptation of initially hydrophobic (β-Na1.5Y1.5F6: Yb3+, Tm3+/β-Na1.5Y1.5F6) core/shell nanoparticles by means of one-step laser treatment in water are demonstrated. “True” 1D nanostructures through “Medusa”-like structures can be obtained, maintaining anti-Stokes luminescence functionalities. A matter of the one-dimensional UCNPs based on direction of energy migration processes is debated. The proposed laser treatment approach is suitable for fast UCNP surface modification and nano-to-nano transformation, that open unique opportunities to expand UCNP applications in industry and biomedicine. [Figure not available: see fulltext.].