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Nowadays, investigations of the existence of global classical solutions for non linear evolution equations is a topic of active mathematical research. In this article, we are concerned with a classical system of shallow water equations which describes long surface waves in a fluid of variable depth. This system was proposed in 1871 by Adh\'{e}mar Jean-Claude Barr\'{e} de Saint-Venant. Namely, we investigate an initial value problem for the one dimensional Saint-Venant equations. We are especially interested in question of what sufficient conditions the initial data and the topography of the bottom must verify in~order that the considered system has global classical solutions. In order to prove our main results we use a~new topological approach based on the fixed point abstract theory of the sum of two operators in Banach spaces. This basic and new idea yields global existence theorems for many of the interesting equations of mathematical physics.

Summary In the last decade, the Holmium Laser Enucleation of the Prostate (HoLEP) has become the new gold standard for surgical treatment of benign prostatic hyperplasia (BPH). This treatment has several modifications, and the latest one is en bloc (single piece) enucleation. This new method reduces the operative time and risk of early incontinence. The long-term effect is much better than transurethral resection of the prostate (TURP). We applied an effective method for treating benign prostatic hyperplasia with maximum safety, minimal hospital stays, short operative time, and minimal complications. We operated on 50 patients with BPH with a prostate volume between 30-120 cc. Transrectal ultrasound, uroflowmetry, PSA test, IPSS (International Prostate Symptom Score), residual urine, digital rectal examination, and laboratory blood and urine tests were performed preoperatively. We used Holmium laser (Auriga XL) 50 W, 600 μm fiber and morcellator (Richard Wolf PIRANHA). During the procedure, the laser’s operating power was 36 W. En bloc Holmium enucleation was performed in all patients, followed by morcellation of the prostatic tissue. The time for enucleation was 11-52 min, morcellation time - 1-10 min, the weight of the enucleated tissue - 15-100 g, enucleation efficiency - 0.67-3.03 g/min, postoperative catheterization time - 24-72h, and hospital stay was 1 to 3 days. One blood transfusion was required. There were no patients with postoperative incontinence or other complications. We conclude that еn bloc Holmium enucleation in BPH is an effective method of treatment that offers maximum performance combined with short operative time, shorter hospital stays, and minimal risk of complications. The learning curve requires at least twenty cases. The recommended prostate gland size for the initial trial should be between 50-60 cc. Starting with small-sized glands increases the risk of capsule perforation, and the enucleation plane is more difficult to find.

In this article we investigate the generalized Kawahara-KdV system. A new topological approach is applied to prove the existence of at least one classical solution and at least two nonnegative classical solutions. The arguments are based upon recent theoretical results.

International audience; We investigated the non-uniformity of the response of the photocathodes of some PMTs and their potential influence on the results of scintillation measurements. We have developed an experimental system which allows us to study the non-uniformity of the photocathode response and its influence on the shape of alpha spectra obtained after pulse-shape discrimination. The system is presented together with the first tests of a Hamamatsu R7600U-200 PMT. A degradation of the counting efficiency and a shift of the peak position towards small values was identified in the measurements near the edges of the photocathode where the energy resolution is significantly worse than the energy resolution at the central region of the PMT. Such non-uniformity also affects absolute activity measurements based on the free parameter model, i.e., the Triple to Double coincidence Ratio (TDCR) method and the CIEMAT/NIST efficiency tracing method. The traditional free parameter model assumes a Poisson distribution of the number of emitted photons but the non-uniformity leads to a compound Poisson distribution, where the mean value of the distribution is a random variable. This introduces an extra variance of the calculated detection efficiency which should be taken into account in the measurement uncertainty budget. Experimental results are presented in the paper, together with their practical influence in scintillation measurements and absolute calibration of radionuclides.

Weakly sufficient conditions that guarantee the existence of positive bounded solutions are obtained for the equation: $$\left(\phi_{p}\left(u^{\prime}(t)\right)\right)^{\prime}+f(u(t))=\theta$$ , $$0

Development of novel technologies for the discovery of human monoclonal antibodies has proven invaluable in the fight against infectious diseases. Among the diverse antibody repertoires elicited by infection or vaccination, often only rare antibodies targeting specific epitopes of interest are of potential therapeutic value. Current antibody discovery efforts are capable of identifying B cells specific for a given antigen; however, epitope specificity information is usually only obtained after subsequent monoclonal antibody production and characterization. Here we describe LIBRA-seq with epitope mapping, a next-generation sequencing technology that enables residue-level epitope determination for thousands of single B cells simultaneously. By utilizing an antigen panel of point mutants within the HIV-1 Env glycoprotein, we identified and confirmed antibodies targeting multiple sites of vulnerability on Env, including the CD4-binding site and the V3-glycan site. LIBRA-seq with epitope mapping is an efficient tool for high-throughput identification of antibodies against epitopes of interest on a given antigen target.

The protective human antibody response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) focuses on the spike (S) protein, which decorates the virion surface and mediates cell binding and entry. Most SARS-CoV-2 protective antibodies target the receptor-binding domain or a single dominant epitope ("supersite") on the N-terminal domain (NTD). Using the single B cell technology called linking B cell receptor to antigen specificity through sequencing (LIBRA-Seq), we isolated a large panel of NTD-reactive and SARS-CoV-2-neutralizing antibodies from an individual who had recovered from COVID-19. We found that neutralizing antibodies against the NTD supersite were commonly encoded by the IGHV1-24 gene, forming a genetic cluster representing a public B cell clonotype. However, we also discovered a rare human antibody, COV2-3434, that recognizes a site of vulnerability on the SARS-CoV-2 S protein in the trimer interface (TI) and possesses a distinct class of functional activity. COV2-3434 disrupted the integrity of S protein trimers, inhibited the cell-to-cell spread of the virus in culture, and conferred protection in human angiotensin-converting enzyme 2-transgenic (ACE2-transgenic) mice against the SARS-CoV-2 challenge. This study provides insight into antibody targeting of the S protein TI region, suggesting this region may be a site of virus vulnerability.

Broadly neutralizing antibodies (bNAbs) may constitute an essential component of a protective vaccine against HIV-1, yet no immunogen has been able to elicit them. To characterize the development of bNAbs in HIV-1 subtype C infected individuals, a panel of 18 Env-pseudotyped viruses was used to screen 18 study participants. The specificity of plasma neutralization was mapped against Env mutants and MPER chimeras. Envelope (env) gene sequence evolution was characterized by single genome amplification and sequencing. Three out of eighteen individuals developed broad plasma neutralizing activity (>60% breadth). Two of the three participants may target epitopes comprising glycans at position 276 of the D loop in the CD4 binding site and 332 glycan supersite, respectively. Deletion of these glycans was associated with neutralization resistance. Our study describes the kinetics of the development of plasma neutralizing activity and identified amino acid residue changes suggestive of immune pressure on putative epitopes. The study enhances our understanding of how neutralization breadth develops in the course of HIV-1 subtype C infection.

Zika virus (ZIKV) has caused significant disease, with widespread cases of neurological pathology and congenital neurologic defects. Rapid vaccine development has led to a number of candidates capable of eliciting potent ZIKV-neutralizing antibodies (reviewed in refs. 1–3). Despite advances in vaccine development, it remains unclear how ZIKV vaccination affects immune responses in humans with prior flavivirus immunity. Here we show that a single-dose immunization of ZIKV purified inactivated vaccine (ZPIV)4–7 in a dengue virus (DENV)-experienced human elicited potent cross-neutralizing antibodies to both ZIKV and DENV. Using a unique ZIKV virion-based sorting strategy, we isolated and characterized multiple antibodies, including one termed MZ4, which targets a novel site of vulnerability centered on the Envelope (E) domain I/III linker region and protects mice from viremia and viral dissemination following ZIKV or DENV-2 challenge. These data demonstrate that Zika vaccination in a DENV-experienced individual can boost pre-existing flavivirus immunity and elicit protective responses against both ZIKV and DENV. ZPIV vaccination in Puerto Rican individuals with prior flavivirus experience yielded similar cross-neutralizing potency after a single vaccination, highlighting the potential benefit of ZIKV vaccination in flavivirus-endemic areas., Zika virus vaccination elicits Zika and dengue virus cross-neutralizing antibodies in flavivirus-exposed individuals, potentially enhancing the protective efficacy of the vaccine in flavivirus-endemic regions.

Understanding convection in red supergiants and the mechanisms that trigger the mass loss from these evolved stars are the general goals of most observations of Betelgeuse and its inner circumstellar environment. Linear spectropolarimetry of the atomic lines of the spectrum of Betelgeuse reveals information about the three-dimensional (3D) distribution of brightness in its atmosphere. We model the distribution of plasma and its velocities and use inversion algorithms to fit the observed linear polarization. We obtain the first 3D images of the photosphere of Betelgeuse. Within the limits of the used approximations, we recover vertical convective flows and measure the velocity of the rising plasma at different heights in the photosphere. In several cases, we find this velocity to be constant with height, indicating the presence of forces other than gravity acting on the plasma and counteracting it. In some cases, these forces are sufficient to maintain plasma rising at 60\,\kms to heights where this velocity is comparable to the escape velocity. Forces are present in the photosphere of Betelgeuse that allow plasma to reach velocities close to the escape velocity. These mechanisms may suffice to trigger mass loss and sustain the observed large stellar winds of these evolved stars., Comment: 15 pages, 10 figures. In press with A&A

The doping of dilute nitrides is an important point of the growth and processing technology for different optoelectronic devices based on these compounds. In this paper, both intentional and nonintentional doping of InGaAsN and GaAsSbN have been investigated by temperature-dependent Hall effect measurements. Dilute nitrides layers have been grown by low-temperature (Tcryst < 600 °C) liquid-phase epitaxy (LPE). The chemical elements Sn and Mg have been chosen as n-type and p-type dopants, respectively. All nominally undoped InGaAsN layers are n-type with free carrier concentration about one order of magnitude higher than layers not containing nitrogen and grown by LPE. This makes it difficult to obtain epitaxial layers with p-type conductivity with these compounds. However, high-quality n-type, p-type and nearly compensated GaAsSbN layers have been successfully grown covering a large range of carrier concentrations from 1015 to 6×1018 cm−3. The quality of the GaAsSbN layers has been evidenced by a good photoresponse with a low energy threshold extended down to 1.2 eV as obtained by surface photovoltage spectroscopy.

Dengue is a major public health threat. There are four serotypes of dengue virus (DENV), therefore efforts are focused on development of safe and effective tetravalent DENV vaccines. While neutralizing antibodies contribute to protective immunity, there are still important gaps in understanding of immune responses elicited by dengue infection and vaccination, including defining immune correlates of protection. To that end, here we present a computational modeling framework for evaluating the specificities of neutralizing antibodies elicited to tetravalent DENV vaccines, based on the concept of antibody-virus neutralization fingerprints. We developed and applied this framework to samples from clinical studies of TAK-003, a tetravalent vaccine candidate currently in phase 3 trials, to characterize the effect of prior dengue infection (baseline) on the specificities of vaccine-elicited antibody responses. Our results suggested a similarity of neutralizing antibody specificities in baseline-seronegative individuals. In contrast, amplification of pre-existing neutralizing antibody specificities was predicted for baseline-seropositive individuals, thus quantifying the role of immunologic imprinting in driving antibody responses to DENV vaccines. The analysis framework proposed here can apply to studies of sequential dengue infections and other tetravalent DENV vaccines and can contribute to understanding dengue immune correlates of protection to help guide further vaccine development and optimization.

The report examines the possibilities and the challenges of transition from mobile learning to mobile research in different stages of education - from primary school through secondary school to university. Available sensors in modern smartphones are analysed. A classification of existing solutions for using smartphones as research devices has been made. The use of smartphones and mobile learning at different stages of education is also analysed. A study of the readiness of the students from the University of Ruse to engage in mobile research is conducted. At the end of this paper, relevant conclusions and recommendations for the use of mobile devices as research tools are made.

Background Transcatheter pulmonary valve implantation (TPVI) is indicated to treat right-ventricular outflow tract dysfunction related to congenital heart disease. Long-term outcomes following TPVI with the new-generation SAPIEN 3 valve are not well documented. Purpose We investigated mid-term outcomes in a large cohort of patients who underwent TPVI using the SAPIEN 3 valve. Methods We retrospectively analysed data from a multicentre observational registry of patients who underwent TPVI with SAPIEN 3 in 30 centres in 12 countries from Europe, the Middle East, and Canada. Patient-related, procedural, and mid-term-outcome data were assessed. Results We obtained data for 713 patients treated in 2014–2021. Number of procedures performed among centres varied from 1 to 190 with a median of 15. Median age was 29.4-year-old [19.0–42.8]. The most common underlying diagnosis was cono-truncal defect (68.9%), with a native or patched right-ventricular outflow tract, a bioprosthetic valve, a homograft and a conduit, in 50.8%, 19.6%, 16.5% and 13.2% patients, respectively. Pre-stenting was performed in 74.8% patients. The 20-mm, 23-mm, 26-mm, and 29-mm valves were used in 0.4%, 28.2%, 31.2%, and 40.2% of patients, respectively. Valve implantation was successful in 98.6% patients. Life-threatening peri-procedural adverse events occurred in 3.7% patients, including 0.6% peri-procedural death. Median follow-up was 1.4 years (maximum, 5.9 years; 1160 patient-years), At last follow-up, pulmonary regurgitation grade 2, 3 and 4 was noted in 6.9%, 0.9% and 0.0% patients, respectively. Median maximal gradient at last follow-up was 18 mmHg. Six patients experienced infective endocarditis (0.5 per 100 patient-years) of whom 1 died and 2 required pulmonary valve replacement. Nine patients (0.8 per 100 patient-years) had secondary pulmonary valve replacement (including 2 by valve-in-valve TPVI; 7 patients had 23-mm and 2 had 26-mm valves). Four patients experienced pulmonary valve thrombosis (0.6 per 100 patient-year) of whom one died and 3 resolved under anticoagulation therapy. Cumulative incidences of infective endocarditis, secondary pulmonary valve replacement and valve thrombosis were 0.7%, 1.3% and 1.3%; 0.4%, 1.3% and 4.6%; 0.5%, 0.5% and 0.8% at 1, 3 and 5 years after TPVI respectively. Conclusion TPVI with the SAPIEN 3 valve was feasible and safe in a wide range of patients with congenital heart defects, most of whom had large native right-ventricular outflow tracts. Mid-term outcomes were favourable. Funding Acknowledgement Type of funding sources: Public hospital(s). Main funding source(s): The study is promoted and financially supported by a Research grant of the Groupe Hospitalier Paris Saint Joseph

SUMMARYRNA-based vaccines against SARS-CoV-2 are critical to limiting COVID-19 severity and spread. Cellular mechanisms driving antigen-specific responses to these vaccines, however, remain uncertain. We used single-cell technologies to identify and characterized antigen-specific cells and antibody responses to the RNA vaccine BNT162b2 in longitudinal samples from a cohort of healthy donors. Mass cytometry and machine learning pinpointed a novel expanding, population of antigen-specific non-canonical memory CD4+ and CD8+ T cells. B cell sequencing suggested progression from IgM, with apparent cross-reactivity to endemic coronaviruses, to SARS-CoV-2-specific IgA and IgG memory B cells and plasmablasts. Responding lymphocyte populations correlated with eventual SARS-CoV-2 IgG and a donor lacking these cell populations failed to sustain SARS-CoV-2-specific antibodies and experienced breakthrough infection. These integrated proteomic and genomic platforms reveal an antigen-specific cellular basis of RNA vaccine-based immunity.ONE SENTENCE SUMMARYSingle-cell profiling reveals the cellular basis of the antigen-specific response to the BNT162b2 SARS-CoV-2 RNA vaccine.

A leading strategy for developing a prophylactic HIV-1 vaccine is the elicitation of antibodies that can neutralize a large fraction of circulating HIV-1 variants. However, a major challenge that has limited the effectiveness of current vaccine candidates is the extensive global diversity of the HIV-1 envelope protein (Env), the sole target for HIV-neutralizing antibodies. To address this challenge, various strategies incorporating Env diversity into the vaccine formulation have been proposed. Here, we assessed the potential of two such strategies that utilize a nanoparticle-based vaccine platform to elicit broadly neutralizing antibody responses. The nanoparticle immunogens developed here consisted of different formulations of Envs from strains BG505 (clade A) and CZA97 (clade C), attached to the N-termini of bacterial ferritin. Single—antigen nanoparticle cocktails, as well as mosaic nanoparticles bearing both Env trimers, elicited high antibody titers in mice and guinea pigs. Furthermore, serum from guinea pigs immunized with nanoparticle immunogens achieved autologous, and in some cases heterologous, tier 2 neutralization, although significant differences between mosaic and single—antigen nanoparticles were not observed. These results provide insights into the ability of different vaccine strategies for incorporating Env sequence diversity to elicit neutralizing antibodies, with implications for the development of broadly protective HIV-1 vaccines.

SARS-CoV-2 therapeutic antibody discovery efforts have met with notable success but have been associated with a generally inefficient process, requiring the production and characterization of exceptionally large numbers of candidates for the identification of a small set of leads. Here, we show that incorporating antibody–ligand blocking as part of LIBRA-seq, the high-throughput sequencing platform for antibody discovery, results in efficient identification of ultra-potent neutralizing antibodies against SARS-CoV-2. LIBRA-seq with ligand blocking is a general platform for functional antibody discovery targeting the disruption of antigen–ligand interactions.

Although several monoclonal antibodies (mAbs) targeting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been approved for coronavirus disease 2019 (COVID-19) therapy, development was generally inefficient, with lead generation often requiring the production and testing of numerous antibody candidates. Here, we report that the integration of target-ligand blocking with a previously described B cell receptor-sequencing approach (linking B cell receptor to antigen specificity through sequencing (LIBRA-seq)) enables the rapid and efficient identification of multiple neutralizing mAbs that prevent the binding of SARS-CoV-2 spike (S) protein to angiotensin-converting enzyme 2 (ACE2). The combination of target-ligand blocking and high-throughput antibody sequencing promises to increase the throughput of programs aimed at discovering new neutralizing antibodies.

The continual emergence of novel coronaviruses (CoV), such as severe acute respiratory syndrome-(SARS)-CoV-2, highlights the critical need for broadly reactive therapeutics and vaccines against this family of viruses. From a recovered SARS-CoV donor sample, we identify and characterize a panel of six monoclonal antibodies that cross-react with CoV spike (S) proteins from the highly pathogenic SARS-CoV and SARS-CoV-2, and demonstrate a spectrum of reactivity against other CoVs. Epitope mapping reveals that these antibodies recognize multiple epitopes on SARS-CoV-2 S, including the receptor-binding domain, the N-terminal domain, and the S2 subunit. Functional characterization demonstrates that the antibodies mediate phagocytosis—and in some cases trogocytosis—but not neutralization in vitro. When tested in vivo in murine models, two of the antibodies demonstrate a reduction in hemorrhagic pathology in the lungs. The identification of cross-reactive epitopes recognized by functional antibodies expands the repertoire of targets for pan-coronavirus vaccine design strategies., Graphical abstract, Shiakolas et al. demonstrate that cross-reactive coronavirus antibodies induced by natural infection display a spectrum of epitope specificities across the spike protein and exhibit in vitro and in vivo antiviral functions.

This paper reports on liquid phase epitaxy (LPE) growth and characterization of monocrystalline dilute nitride InGaAs(Sb)N and GaAsSbN layers in view of their photovoltaic applications. To obtain high quality epitaxial layers without phase separation the low-temperature variant of the LPE method is used. The structural characterization of the samples is carried out by means of scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction measurements. The optical bandgap is studied by photoluminescence (PL) spectroscopy at low and room temperature. Surface photovoltage spectroscopy (SPV) is applied to determine the optical absorption edge. Both PL and SPV spectra reveal a decrease of the band gap of GaAsSbN as compared to InGaAs(Sb)N, which is of value for its application in solar cells.

The emergence of novel SARS-CoV-2 lineages that are more transmissible and resistant to currently approved antibody therapies poses a considerable challenge to the clinical treatment of COVID-19. Therefore, the need for ongoing discovery efforts to identify broadly reactive monoclonal antibodies to SARS-CoV-2 is of utmost importance. Here, we report a panel of SARS-CoV-2 antibodies isolated using the LIBRA-seq technology from an individual who recovered from COVID-19. Of these antibodies, 54042-4 showed potent neutralization against authentic SARS-CoV-2 viruses, including variants of concern (VOCs). A cryo-EM structure of 54042-4 in complex with the SARS-CoV-2 spike revealed an epitope composed of residues that are highly conserved in currently circulating SARS-CoV-2 lineages. Further, 54042-4 possesses unique genetic and structural characteristics that distinguish it from other potently neutralizing SARS-CoV-2 antibodies. Together, these findings motivate 54042-4 as a lead candidate for clinical development to counteract current and future SARS-CoV-2 VOCs.

Introduction: A lot of clinical studies have shown that during prolonged surgery protective ventilation strategy, including low tidal volume, PEEP and recruitment maneuvers (RM) can reduce the rate of postoperative pulmonary complications, which are the second most common cause for postoperative mortality. Therefore, it is important to investigate clinical methods for preventing them. The strategy of protective ventilation is easy and safe for the patients and inexpensive for application during prolonged surgery. Aims: The objective of this trial was to study whether application of PEEP in patients during prolonged gynecological surgery could decrease the postoperative complications. Material and Methods: We compared the rates of postoperative complications in patients after prolonged open gynecological surgery, who were divided into 2 groups – group A, which was the control group on non-protective ventilation (35 patients) and group B on protective ventilation (35 patients). The patients in the control group were ventilated with tidal volume (VT) of 8-10 ml/kg without PEEP and RM; the patients in group B were ventilated with VT = 6-8 ml/kg according to their Predicted Body Weight, with a PEEP of 6 cm H2O and RM, which consisted of applying continuous positive airway pressure of 30 cm H2O for 30 seconds. RM was performed after intubation, after every disconnection from ventilator and before extubation. The study was successfully performed without a need for a change in the type of ventilation strategy because of hypoxia or hemodynamic instability. Statistical nonparametric test (e.g. chi-square) was applied. Results: Total rate of all postoperative complications observed in both groups was 27,1%. We found a significant relationship between application of PEEP and lower rates of postoperative pulmonary complications in group A (39,4%) compared to group B (12,1%), lower rate of respiratory failure (33,3% in group A vs. 9,1% in group B -) and atelectasis (21,2% in group A vs. 0% in group B). Conclusion: The protective ventilation strategy (low VT, PEEP and RM) in patients during prolonged gynecological surgery can reduce the rate of postoperative pulmonary complications such as respiratory failure and atelectasis.

The present vaccine against influenza virus has the inevitable risk of antigenic discordance between the vaccine and the circulating strains, which diminishes vaccine efficacy. This necessitates new approaches that provide broader protection against influenza. Here we designed a vaccine using the hypervariable receptor-binding domain (RBD) of viral hemagglutinin displayed on a nanoparticle (np) able to elicit antibody responses that neutralize H1N1 influenza viruses spanning over 90 years. Co-display of RBDs from multiple strains across time, so that the adjacent RBDs are heterotypic, provides an avidity advantage to cross-reactive B cells. Immunization with the mosaic RBD–np elicited broader antibody responses than those induced by an admixture of nanoparticles encompassing the same set of RBDs as separate homotypic arrays. Furthermore, we identified a broadly neutralizing monoclonal antibody in a mouse immunized with mosaic RBD–np. The mosaic antigen array signifies a unique approach that subverts monotypic immunodominance and allows otherwise subdominant cross-reactive B cell responses to emerge. Antigenic variation of influenza A viruses necessitates the annual reformulation of vaccines. Kanekiyo et al. develop a mosaic nanoparticle vaccine against influenza virus that is able to elicit neutralizing antibodies that span nearly 100 years of variation of influenza A virus.

Summary Determining which immunological mechanisms contribute to the development of broad neutralizing antibodies (bNAbs) during HIV-1 infection is a major goal to inform vaccine design. Using samples from a longitudinal HIV-1 acute infection cohort, we found key B cell determinants within the first 14–43 days of viremia that predict the development of bNAbs years later. Individuals who develop neutralization breadth had significantly higher B cell engagement with the autologous founder HIV envelope (Env) within 1 month of initial viremia. A higher frequency of founder-Env-specific naive B cells was associated with increased B cell activation and differentiation and predictive of bNAb development. These data demonstrate that the initial B cell interaction with the founder HIV Env is important for the development of broadly neutralizing antibodies and provide evidence that events within HIV acute infection lead to downstream functional outcomes.

[This corrects the article DOI: 10.1371/journal.ppat.1009101.].

Dilute nitrides are semiconductor alloys, obtained from the conventional III-V compounds by incorporating a small amount of nitrogen. In this work, we focus on GaAsSbN considered as a perspective material for incorporation in multijunction solar cells. Nitrogen creates a localized level inside the conduction band continuum. The interaction of this level with the conduction band is usually described by the single band anti-crossing (BAC) model. The double BAC model of GaAsSbN considers both the N and the Sb localized levels in the conduction and the valence band, respectively. We calculate the bandgap energy of GaAsSbN employing the double BAC model for different concentrations of Sb and N. Parameters of the BAC model taken from different literature sources are used in the calculations and their influence on the final result is explored. Finally, the calculated bandgap energies are compared to experimental data of GaAsSbN layers grown on n-GaAs substrates by low-temperature liquid phase epitaxy. These data include the optical absorption edge of the material determined by surface photovoltage spectroscopy and the energy position of the photoluminescence peak at room temperature.