eXplainable Artificial Intelligence (XAI) in aging clock models

eXplainable Artificial Intelligence (XAI) is a rapidly progressing field of machine learning, aiming to unravel the predictions of complex models. XAI is especially required in sensitive applications, e.g. in health care, when diagnosis, recommendations and treatment choices might rely on the decisions made by artificial intelligence systems. AI approaches have become widely used in aging research as well, in particular, in developing biological clock models and identifying biomarkers of aging and age-related diseases. However, the potential of XAI here awaits to be fully appreciated. We discuss the application of XAI for developing the "aging clocks" and present a comprehensive analysis of the literature categorized by the focus on particular physiological systems

Ultrasound-guided intramural inoculation of orthotopic bladder cancer xenografts: a novel high-precision approach

Orthotopic bladder cancer xenografts are essential for testing novel therapies and molecular manipulations of cell lines in vivo. Current xenografts rely on tumor cell inoculation by intravesical instillation or direct injection into the bladder wall. Instillation is limited by the lack of cell lines that are tumorigenic when delivered in this manner. The invasive model inflicts morbidity on the mice by the need for laparotomy and mobilization of the bladder. Furthermore this procedure is complex and time-consuming. Three bladder cancer cell lines (UM-UC1, UM-UC3, UM-UC13) were inoculated into 50 athymic nude mice by percutaneous injection under ultrasound guidance. PBS was first injected between the muscle wall and the mucosa to separate these layers, and tumor cells were subsequently injected into this space. Bioluminescence and ultrasound were used to monitor tumor growth. Contrast-enhanced ultrasound was used to study changes in tumor perfusion after systemic gemcitabine/cisplatin treatment. To demonstrate proof of principle that therapeutic agents can be injected into established xenografts under ultrasound guidance, oncolytic virus (VSV) was injected into UM-UC3 tumors. Xenograft tissue was harvested for immunohistochemistry after 23–37 days. Percutaneous injection of tumor cells into the bladder wall was performed efficiently (mean time: 5.7 min) and without complications in all 50 animals. Ultrasound and bioluminescence confirmed presence of tumor in the anterior bladder wall in all animals 3 days later. The average tumor volumes increased steadily over the study period. UM-UC13 tumors showed a marked decrease in volume and perfusion after chemotherapy. Immunohistochemical staining for VSV-G demonstrated virus uptake in all UM-UC3 tumors after intratumoral injection. We have developed a novel method for creating orthotopic bladder cancer xenograft in a minimally invasive fashion. In our hands this has replaced the traditional model requiring laparotomy, because this model is more time efficient, more precise and associated with less morbidity for the mice

Vive la radiorésistance!: converging research in radiobiology and biogerontology to enhance human radioresistance for deep space exploration and colonization.

While many efforts have been made to pave the way toward human space colonization, little consideration has been given to the methods of protecting spacefarers against harsh cosmic and local radioactive environments and the high costs associated with protection from the deleterious physiological effects of exposure to high-Linear energy transfer (high-LET) radiation. Herein, we lay the foundations of a roadmap toward enhancing human radioresistance for the purposes of deep space colonization and exploration. We outline future research directions toward the goal of enhancing human radioresistance, including upregulation of endogenous repair and radioprotective mechanisms, possible leeways into gene therapy in order to enhance radioresistance via the translation of exogenous and engineered DNA repair and radioprotective mechanisms, the substitution of organic molecules with fortified isoforms, and methods of slowing metabolic activity while preserving cognitive function. We conclude by presenting the known associations between radioresistance and longevity, and articulating the position that enhancing human radioresistance is likely to extend the healthspan of human spacefarers as well

Half-Watt Average Power Femtosecond Source Spanning 3–8 µm Based On Subharmonic Generation In Gaas

Frequency combs with a wide instantaneous spectral span covering the 3–20 µm molecular fingerprint region are highly desirable for broadband and high-resolution frequency comb spectroscopy, trace molecular detection, and remote sensing. We demonstrate a novel approach for generating high-average-power middle-infrared (MIR) output suitable for producing frequency combs with an instantaneous spectral coverage close to 1.5 octaves. Our method is based on utilizing a highly-efficient and compact Kerr-lens mode-locked Cr2+:ZnS laser operating at 2.35-µm central wavelength with 6-W average power, 77-fs pulse duration, and high 0.9-GHz repetition rate; to pump a degenerate (subharmonic) optical parametric oscillator (OPO) based on a quasi-phase-matched GaAs crystal. Such subharmonic OPO is a nearly ideal frequency converter capable of extending the benefits of frequency combs based on well-established mode-locked pump lasers to the MIR region through rigorous, phase- and frequency-locked down conversion. We report a 0.5-W output in the form of an ultra-broadband spectrum spanning 3–8 µm measured at 50-dB level

Sub-Watt Femtosecond Laser Source With The Spectrum Spanning 3-8 Μm

We demonstrate an approach to a middle-IR frequency comb generator, which uniquely combines Watt-level power, exceptionally broad spectrum and small footprint. The source is based on an OP-GaAs OPO synchronously pumped by a Cr:ZnS femtosecond MOPA

Half-Watt Average Power Compact Femtosecond Source With A Bandwidth Of 3-8 Μm Based On Subharmonic Gaas Opo

High-power (0.5 W) mid-IR output suitable for ultra-broadband frequency comb generation was produced in a subharmonic GaAs optical parametric oscillator that was synchronously pumped by a compact 0.9 GHz, 6 W femtosecond Cr:ZnS (2.35μm) MOPA

Half-Watt Average Power Compact Femtosecond Source With A Bandwidth Of 3-8 Μm Based On Subharmonic Gaas Opo

High-power (0.5 W) mid-IR output suitable for ultra-broadband frequency comb generation was produced in a subharmonic GaAs optical parametric oscillator that was synchronously pumped by a compact 0.9 GHz, 6 W femtosecond Cr:ZnS (2.35μm) MOPA

Predictors of Unfavorable Outcomes in Patients with Atrial Fibrillation and Concomitant Heart Failure with Different Ejection Fractions: RIF-CHF Register One-Year Follow-Up

Background. Atrial fibrillation (AF) and heart failure (HF) are tightly interrelated. The concurrence of these pathologies can aggravate the pathological process. The geographic and ethnic characteristics of patients may significantly affect the efficacy of different types of therapy and patients’ compliance. The objective of this study was to analyze how the features of the course of the diseases and management of HF + AF influence the clinical outcomes. Methods. The data of 1,003 patients from the first Russian register of patients with chronic heart failure and atrial fibrillation (RIF-CHF) were analyzed. The endpoints included hospitalization due to HF worsening, mortality, thromboembolic events, and hemorrhage. Predictors of unfavorable outcomes were analyzed separately for patients with HF and preserved ejection fraction (AF + HFpEF), midrange ejection fraction (AF + HFmrEF), and reduced ejection fraction (AF + HFrEF). Prevalence of HF + AF and compliance with long-term treatment of this pathology during one year were evaluated for each patient. Results. The study involved 39% AF + HFpEF patients, 15% AF + HFmrEF patients, and 46% AF + HFrEF patients. AF + HFpEF patients were significantly older than patients in two other groups (40.6% of patients were older than ≥75 years vs. 24.8%, respectively, p<0.001) and had the lowest rate of prior myocardial infarctions (25.3% vs. 46.1%, p<0.001) and the lowest adherence to rational therapy of HF (27.4% vs. 47.1%, p<0.001). AF + HFmrEF patients had the highest percentage of cases of HF onset after AF (61.3% vs. 49.2% in other patient groups, p=0.021). Among patients with AF + HFrEF, there was the highest percentage of males (74.2% vs. 41% in other patient groups, p<0.001) and the highest percentage of ever-smokers (51.9% vs. 29.4% in other patient groups, p<0.001). A total of 57.2% of patients were rehospitalized for decompensation of chronic heart failure within one year; the risk was the highest for AF + HFmrEF patients (66%, p=0.017). Reduced ejection fraction was associated with the increased risk of cardiovascular mortality (15.5% vs. 5.4% in other patient groups, p<0.001) rather than ischemic stroke (2.4% vs. 3%, p=0.776). Patients with AF + HFpEF had lower risk to achieve the combination point (stroke + IM + CV death) as compared to patients with AF + HFmrEF and AF + HFrEF (12.7% vs. 22% and 25.5%, p<0.001). Regression logistic analysis revealed that factors such as demographic characteristics, disease severity, and administered treatment had different effects on the risk of unfavorable outcomes depending on ejection fraction group. The clinical features and symptoms were found to be significant risk factors of cardiovascular mortality in AF + HFmrEF, while therapy characteristics were not associated with it. Conclusions. Each group of patients with different ejection fractions is characterized by its own pattern of factors associated with the development of unfavorable outcomes. The demographic and clinical characteristics of patients with midrange ejection fraction demonstrate that these patients need to be studied as a separate cohort

Role of Bacterial Surface Components in the Pathogenicity of <i>Proteus mirabilis</i> in a Murine Model of Catheter-Associated Urinary Tract Infection

Proteus mirabilis (PM) is a Gram-negative, rod-shaped bacterium that causes catheter-associated urinary tract infections (CAUTIs). The specific roles of bacterial surface components (BSCs) in PM pathogenicity and CAUTIs remain unknown. To address this knowledge gap, we utilized relevant in vitro adhesion/invasion models and a well-established murine model of CAUTI to assess the ability of wildtype (WT) and seven mutant strains (MSs) of PM with deficiencies in various genes encoding BSCs to undergo the infectious process (including adhesion to catheters) in both model systems. Overall, MSs adhesion to catheters and the different cell types tested was significantly reduced compared to WT, while no invasion of cells was evident at 24 h. In vivo, WT showed a greater number of planktonic (urine) bacteria, bacteria adherent to catheters, and bacteria adherent to/invading bladder tissue when compared to the MSs. Bacterial counts in urine for PMI3191 and waaE mutants were lower than that for WT and other MSs. The complementation of mutated BSC genes resulting in the biggest defects restored the invasion phenotype both in vitro and in vivo. BSCs play a critical role at various steps in the pathogenicity of PM including adhesion to indwelling medical devices and adhesion/invasion of urinary tissue in vivo