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We give a review of the calculations of the masses of tetraquarks with two and four heavy quarks in the framework of the relativistic quark model based on the quasipotential approach and QCD. The diquark-antidiquark picture of heavy tetraquarks is used. The quasipotentials of the quark-quark and diquark-antidiquark interactions are constructed similarly to the previous consideration of mesons and baryons. Diquarks are considered in the colour triplet state. It is assumed that the diquark and antidiquark interact in the tetraquark as a whole and the internal structure of the diquarks is taken into account by the calculated form factor of the diquark-gluon interaction. All parameters of the model are kept fixed from our previous calculations of meson and baryon properties. A detailed comparison of the obtained predictions for heavy tetraquark masses with available experimental data is given. Many candidates for tetraquarks are found. It is argued that the structures in the di-J/ψ mass spectrum observed recently by the LHCb collaboration can be interpreted as ccc¯c¯ tetraquarks.

Masses of the ground and excited (1P, 2S, 1D, 2P, 3S) states of the fully heavy tetraquarks, composed of charm (c) and bottom (b) quarks and antiquarks, are calculated in the diquark–antidiquark picture within the relativistic quark model based on the quasipotential approach and quantum chromodynamics. The quasipotentials of the quark–quark and diquark–antidiquark interactions are constructed similarly to the previous consideration of mesons and baryons. Relativistic effects are consistently taken into account. A tetraquark is considered a bound state of a diquark and an antidiquark. The finite size of the diquark is taken into account, using the form factors of the diquark–gluon interaction. It is shown that most of the investigated states of tetraquarks lie above the decay thresholds into a meson pair; as a result, they can be observed only as broad resonances. The narrow state X(6900) recently discovered in the di-J/ψ production spectrum by the LHCb, CMS and ATLAS Collaborations corresponds to an excited state of the fully charmed tetraquark. Other recently discovered exotic heavy resonances, X(6200), X(6400), X(6600), X(7200), and X(7300), can also be interpreted as the different excitations of the fully charmed tetraquark.

The paper describes a new model of a job-scheduling problem generalized for nonmonotonic reward functions. The importance of informational asymmetry is shown for the conflict under consideration, leading to a connection with “conspiracy theory.” Structurally consistent equilibria are demonstrated to be acceptable as a solution concept.

Using non-pecuniary interventions to motivate pro-environmental behavior appeals to program administrators seeking cost-effective ways to increase adoption of environmental practices. However, all good-intended interventions should not be expected to be effective and reporting when interventions fail is as important as documenting their successes. We used a framed field experiment with 308 adults from the Mid-Atlantic in the United States to test the effectiveness of an expert testimonial in encouraging adoption of native plants in residential settings. Though studies have found testimonials to be effective in other contexts, we find that the video testimonial had no effect on residents’ willingness to pay for native plants. Our analysis also shows that consumers who are younger, have higher incomes, and use other environmentally friendly practices on their lawns are more likely than other consumers to purchase native plants.

Understanding chemical reactivity and magnetism of 3 d transition metal nanoparticles is of fundamental interest for applications in fields ranging from spintronics to catalysis. Here, we present an atomistic picture of the early stage of the oxidation mechanism and its impact on the magnetism of Co nanoparticles. Our experiments reveal a two-step process characterized by (i) the initial formation of small CoO crystallites across the nanoparticle surface, until their coalescence leads to structural completion of the oxide shell passivating the metallic core; (ii) progressive conversion of the CoO shell to Co 3 O 4 and void formation due to the nanoscale Kirkendall effect. The Co nanoparticles remain highly reactive toward oxygen during phase (i), demonstrating the absence of a pressure gap whereby a low reactivity at low pressures is postulated. Our results provide an important benchmark for the development of theoretical models for the chemical reactivity in catalysis and magnetism during metal oxidation at the nanoscale. 3d transition metal nanoparticles are of interest in fields ranging from spintronics, catalysis, and biomedicine. This paper provides a detailed picture of the oxidation of cobalt nanoparticles and benchmarks the development of models for the metal oxidation and magnetic phenomena at the nanoscale.

High expectations have been set on gene therapy with an AAV-delivered shortened version of dystrophin (µDys) for Duchenne muscular dystrophy (DMD), with several drug candidates currently undergoing clinical trials. Safety concerns with this therapeutic approach include the immune response to introduced dystrophin antigens observed in some DMD patients. Recent reports highlighted microutrophin (µUtrn) as a less immunogenic functional dystrophin substitute for gene therapy. In the current study, we created a human codon-optimized µUtrn which was subjected to side-by-side characterization with previously reported mouse and human µUtrn sequences after rAAV9 intramuscular injections in mdx mice. Long-term studies with systemic delivery of rAAV9-µUtrn demonstrated robust transgene expression in muscles, with localization to the sarcolemma, functional improvement of muscle performance, decreased creatine kinase levels, and lower immunogenicity as compared to µDys. An extensive toxicity study in wild-type rats did not reveal adverse changes associated with high-dose rAAV9 administration and human codon-optimized µUtrn overexpression. Furthermore, we verified that muscle-specific promoters MHCK7 and SPc5-12 drive a sufficient level of rAAV9-µUtrn expression to ameliorate the dystrophic phenotype in mdx mice. Our results provide ground for taking human codon-optimized µUtrn combined with muscle-specific promoters into clinical development as safe and efficient gene therapy for DMD.

A methodology for calculating the consumption of combined alternative energy sources is proposed. The provision of electrical energy to the mini–workshop area for 7 hours a day with equipment that constantly consumes 5.5 kW of electricity was considered. The amount of electrical power needed to meet daily needs has been calculated. It is Rd = 38.5 kWh. Solar stations’ daily solar energy output is determined by considering the required backup power. It is Rst = Rd ·2 = 77.0 kWh. The total power of the solar panels is found. It is Rsp = 9.7 kW. The number of solar panels for the proposed Solar LR5-54HTH-435M example is calculated as several panels Nnp = 23.3 pieces. An inverter with more than 5.5 kW was selected in the given example. Anern EVO-6200 has a power of 6.2 kW and an input for connecting a 48 V battery. Its technical characteristics are presented. A scheme for connecting 24 solar panels was proposed, connecting 12 in series into one electrical circuit. There should be two such chains that are connected in parallel. The calculation is made for a Jarrett 120Ah 12V battery. Its capacity is Rb = 1440 Wh. The battery has the technical ability to store 1440 Wh of electrical energy. The batteries should be Nb = 17.4 pieces ≈ 20 to provide a mini–workshop. The choice of a storage station with 20 pieces of Jarrett 120Ah 12V batteries was justified.

Perioperative dry eye syndrome (DES) is a common ocular complication of long-term general anesthesia. Chronic DES can lead to permanent damage to the cornea and disturbance of visual function, up to total loss of vision. Here, a relationship between the duration of general anesthesia and the risk of chronic DES in patients was demonstrated. Using an experimental model of perioperative corneal abrasions in rabbits, it was found that introduction of animals to 3-h general anesthesia resulted in clinically significant chronic damage to the cornea in 50% of cases. The development of the complication was not associated with irreversible or long-term impairment of tear secretion, but it was accompanied by a decrease in tear film stability and growth of the total protein content as well as decrease in total antioxidant activity of the tear induced by low molecular weight antioxidants. In addition, anesthesia-induced changes in activity of tear antioxidant enzymes including superoxide dismutase and enzymes providing homeostasis of reduced glutathione (glutathione peroxidase, glutathione-S-transferase, glutathione reductase) were observed. All these alterations were protracted (up to 1-2 weeks) and therefore might account for transition of the perioperative DES into the chronic form. These findings can be useful in the development of novel approaches for the prevention and treatment of chronic forms of DES in the postanesthetic period.

Masses of the ground, orbitally and radially excited states of the asymmetric fully heavy tetraquarks, composed of charm ( c ) and bottom ( b ) quarks and antiquarks are calculated in the relativistic diquark–antidiquark picture. The relativistic quark model based on the quasipotential approach and quantum chromodynamics is used to construct the quasipotentials of the quark–quark and diquark–antidiquark interactions. These quasipotentials consist of the short-range one-gluon exchange and long-distance linear confinement interactions. Relativistic effects are consistently taken into account. A tetraquark is considered as a bound state of a diquark and an antidiquark which are treated as a spatially extended colored objects and interact as a whole. It is shown that most of the investigated tetraquarks states (including all ground states) lie above the fall-apart strong decay thresholds into a meson pair. As a result they could be observed as wide resonances. Nevertheless, several orbitally excited states lie slightly above or even below these fall-apart thresholds, thus they could be narrow states.

The taxonomically challenging genus Calendula L. (Asteraceae) includes lots of medicinal species characterized by their high morphological and karyological variability. For the first time, a repeatome analysis of a valuable medicinal plant Calendula officinalis L. was carried out using high-throughput genome DNA sequencing and RepeatExplorer/TAREAN pipelines. The FISH-based visualization of the 45S rDNA, 5S rDNA, and satellite DNAs of C. officinalis was performed on the chromosomes of C. officinalis, C. stellata Cav., C. tripterocarpa Rupr., and C. arvensis L. Three satellite DNAs were demonstrated to be new molecular chromosome markers to study the karyotype structure. Karyograms of the studied species were constructed, their ploidy status was specified, and their relationships were clarified. Our results showed that the C. officinalis karyotype differed from the karyotypes of the other three species, indicating its separate position in the Calendula phylogeny. However, the presence of common repeats revealed in the genomes of all the studied species could be related to their common origin. Our findings demonstrated that C. stellata contributed its genome to allotetraploid C. tripterocarpa, and C. arvensis is an allohexaploid hybrid between C. stellata and C. tripterocarpa. At the same time, further karyotype studies of various Calendula species are required to clarify the pathways of chromosomal reorganization that occurred during speciation.