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Absorption and transmittance of macroporous silicon and nanowires are calculated using the proposed analytical model. The analytical model takes into account the absorption and transmission of the macroporous layer and the monocrystalline substrate. The influence of the pore volume fraction and pore depth on the absorption and transmittance of macroporous silicon is calculated. The macroporous layer and the nanowire layer are considered as an effective medium. The structured surfaces of the macroporous layer are considered as Lambert surfaces. Absorption and transmittance of macroporous silicon and silicon nanowires are calculated according to formulas found analytically. Reflection from the surfaces of macroporous silicon affects the absorption, transmission, and trapping of light by the macroporous silicon. The absorption of macroporous silicon increases with an increase in the volume fraction of pores, due to a decrease in the effective refractive index of the macroporous silicon layer. The absorption of macroporous silicon begins to decrease at high pore volume fraction due to the increase in reflection from the boundary of the layer of macroporous silicon with a monocrystalline substrate. The absorption spectrum of macroporous silicon does not depend on the pore depth when the pore volume fraction is less than 0.25. The transmittance of macroporous silicon increases with an increase in the volume fraction of pores in relation to single crystal silicon. An increase in the thickness of the macroporous silicon and a decrease in the thickness of the monocristalline substrate lead to an increase in the transmittance of macroporous silicon. [ABSTRACT FROM AUTHOR]

The paper presents the theory and calculation of transmission, reflection, and absorption of macroporous silicon with through pores. Macroporous silicon with through pores is considered as an effective medium, the surface of which scatters electromagnetic waves. Scattering by the surface of macroporous silicon is taken into account using the effective scattering angle. The effective complex refractive index and the effective absorption coefficient are calculated using the mixing formulas. Derived analytical formulas for calculating transmittance, reflection and absorption of macroporous silicon with through pores take into account multiple reflections from the inner sides of the front and back surfaces. The influence of the volume fraction of pores and the thickness of macroporous silicon with through-pores on its reflection, transmission, and absorption was analyzed. The reflection and transmittance of the front and back surfaces and the absorption by the effective volume of macroporous silicon depend on the volume fraction of pores and affect the optical properties of macroporous silicon with through pores. [ABSTRACT FROM AUTHOR]

The kinetics of charge carriers in bilateral macroporous silicon with macroporous layers of equal thicknesses is calculated by the finite difference method. A diffusion equation for a monocrystalline substrate and macroporous layers is solved. The boundary conditions are defined at the boundaries between the monocrystalline substrate and the macroporous silicon layers on both sides. Stationary distribution of excess charge carriers in the bilateral macroporous silicon with the macroporous layers of equal thicknesses calculated by the finite difference method is set as the initial condition. Under stationary conditions, excess charge carriers are generated by light with the wavelengths of 0.95 μm and 1.05 μm. It is shown that at the counting times much longer than the relaxation time, all the distributions of the concentration of excess minority carriers generated by light with any wavelength approach the same distribution with exponentially decreasing value. [ABSTRACT FROM AUTHOR]

The resistance of Chronic Lymphocytic Leukemia (CLL) B-cells to cell death is mainly attributed to interactions within their microenvironment, where they interact with various types of cells. Within this microenvironment, CLL-B-cells produce and bind cytokines, growth factors, and extracellular vesicles (EVs). In the present study, EVs purified from nurse-like cells and M2-polarized THP1 cell (M2-THP1) cultures were added to CLL-B-cells cultures. EVs were rapidly internalized by B-cells, leading to a decrease in apoptosis (P = 0.0162 and 0.0469, respectively) and an increased proliferation (P = 0.0335 and 0.0109). Additionally, they induced an increase in the resistance of CLL-B-cells to Ibrutinib, the Bruton kinase inhibitor in vitro (P = 0.0344). A transcriptomic analysis showed an increase in the expression of anti-apoptotic gene BCL-2 (P = 0.0286) but not MCL-1 and an increase in the expression of proliferation-inducing gene APRIL (P = 0.0286) following treatment with EVs. Meanwhile, an analysis of apoptotic protein markers revealed increased amounts of IGFBP-2 (P = 0.0338), CD40 (P = 0.0338), p53 (P = 0.0219) and BCL-2 (P = 0.0338). Finally, exploration of EVs protein content by mass spectrometry revealed they carry various proteins involved in known oncogenic pathways and the RNAseq analysis of CLL-B-cells treated or not with NLCs EVs show various differentially expressed genes., (© 2024. The Author(s).)

Current therapies that target the B-cell receptor pathway or the inhibition of anti-apoptotic proteins do not prevent the progressive forms of chronic lymphocytic leukemia (CLL), have low long-term efficacy and are subject to therapeutic resistance. Deciphering the mechanisms of leukemic cell survival and searching for new specific targets therefore remain major challenges to improve the management of this disease. It was evidenced that NTSR2 (neurotensin receptor 2), through the recruitment of TRKB (tropomyosin related kinase B), induces survival pathways in leukemic B cells. We have investigated the therapeutic potential of this protein complex as a new target. The binding domain of NTSR2 and TRKB was identified and a peptide targeting the latter was designed. The peptide binds TRKB and efficiently decreases the interaction of the two proteins. It is also effectively internalized by CLL-B cells in which it notably affects Src family kinase signaling and anti-apoptotic proteins levels. It demonstrated a cytotoxic effect both in vitro on the MEC-1 cell line and ex vivo on a cohort of 30 CLL patients. Altogether, these results underline the therapeutic potential of the NTSR2/TRKB protein complex as a target in CLL and open new perspectives for the development of targeted therapies., (© 2024. The Author(s).)

Non-beta-hemolytic streptococci (NBHS), also referred to as viridans streptococci, represent an underestimated cause of human invasive diseases. Their resistance to antibiotics, including beta-lactam agents, often complicate their therapeutic management. A prospective multicenter study was conducted by the French National Reference Center for Streptococci between March and April 2021 to describe the clinical and microbiological epidemiology of invasive infections due to NBHS, excluding pneumococcus. A total of 522 NBHS invasive cases were collected. Distribution among streptococcal groups was: Streptococcus anginosus (33%), Streptococcus mitis (28%), Streptococcus sanguinis (16%), Streptococcus bovis /equinus (15%), Streptococcus salivarius (8%), and Streptococcus mutans (<1%). Median age of infection was 68 years old (range <1 day to 100 years). Cases were more frequent in male patients (gender ratio M/F 2.1:1) and manifested mainly as bacteremia without focus (46%), intra-abdominal infections (18%) and endocarditis (11%). All isolates were susceptible to glycopeptides and displayed low-level inherent gentamicin resistance. All isolates of the S. bovis /equinus , S. anginosus , and S. mutans groups were susceptible to beta-lactams. Conversely, nonsusceptibility to beta-lactams was found in 31%, 28%, and 52% of S. mitis, S. salivarius , and S. sanguinis isolates, respectively. The screening for beta-lactam resistance using the recommended one unit benzylpenicillin disk screening failed to detect 21% of resistant isolates (21/99). Last, overall resistance rates to the alternative anti-streptococcal molecules clindamycin and moxifloxacin were 29% (149/522) and 1.6% (8/505), respectively. IMPORTANCE NBHS are recognized as opportunistic pathogens particularly involved in infections of the elderly and immunocompromised patients. This study underlines their importance as common causes of severe and difficult-to-treat infections such as endocarditis. Although species of the S. anginosus and S. bovis/ equinus groups remain constantly susceptible to beta-lams, resistance in oral streptococci exceeds 30% and screening techniques are not fully reliable. Therefore, accurate species identification and antimicrobial susceptibility testing by MICs determination appears essential for the treatment of NBHS invasive infections, together with continued epidemiological surveillance., Competing Interests: The authors declare no conflict of interest.

Group B Streptococcus (GBS) is the leading cause of neonatal infections and an important pathogen in pregnancy. However, the features of pregnancy-associated infections are poorly reported. We analyzed 336 cases of GBS invasive infections in women aged 18-50 years, including 242 (72.0%) pregnancy-associated infections. In pregnancy, most cases were intra-amniotic infections (55.8%), occurred preterm (61.3%), and were associated with obstetrical and neonatal complications (81.7%). The GBS clone CC-17 (18.8% of the cases) was overrepresented intrapartum (35.2%; odds ratio, 5.1 [95% confidence interval, 1.6-19.3]). This work highlights the burden of GBS and of the CC-17 clone infections during pregnancy., (© The Author(s) 2022. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Background: Differential diagnosis of Waldenström macroglobulinemia (WM) with other indolent B-cell malignancies is still a challenge. Here, we propose an original and simple analysis of routine flow cytometry (FCM) unraveling the characteristic ongoing plasma cell (PC) differentiation of WM tumor B-cells., Methods: FCM analysis of both B-cells and PC was performed on a series of 77 patients with IgM peak. MYD88 and CXCR4 mutations were studied using an allele-specific PCR and by high throughput sequencing., Results: Twenty seven (35%), 46 (58%) and 4 (5%) patients were classified as WM, IgM monoclonal gammopathy of undetermined significance (MGUS) or other B-NHL respectively. MYD88 mutation was found in 25/27 WM (93%) and in 29/46 MGUS (63%). Using FCM, monotypic B-cells were found in 27/27 WM (100%) and 34/46 MGUS (74%). Monotypic CD138pos/CD38pos PCs were detected in 23/27 WM (85%) and 25/46 MGUS (54%). Highlighting the ongoing PC differentiation of WM tumor B-cells by FCM, we evidenced a CD138 expression continuum between monotypic B-cells and PCs. This pattern remained absent in control samples and was significantly associated with higher IgM peaks (p = 6.10 -5 ) and MYD88 mutations (p = 10 -3 ) in both WM and MGUS cases., Conclusions: FCM exploration of both B-cells and PC led to identify a CD138 expression continuum as an objective marker of ongoing PC differentiation of WM tumor cells and was strongly associated with increased IgM peak levels and MYD88 mutations. This approach could contribute to place FCM at the forefront of WM diagnosis., (© 2021 International Clinical Cytometry Society.)