Intraindividual variability of semen quality, proteome, and sncRNA profiles in a healthy cohort of young adults.

BACKGROUND: Within-subject variability of semen parameters and molecular components of ejaculates in young men remains poorly understood. OBJECTIVES: To investigate intraindividual variability (IIV) of semen parameters and molecular markers in repeated ejaculates from young men. MATERIALS AND METHODS: Semen parameters were assessed in samples collected 6-8 days apart from 164 18-19-year old participants of the Russian Children's Study, a prospective cohort. Subsets of paired samples were used for label-free quantitation and targeted mass-spectrometry of proteins in seminal plasma (SP) and seminal extracellular vesicles (EVs), and for small non-coding RNA (sncRNA) profiling in EVs and spermatozoa using RNA-seq. The mean difference between two ejaculates, within-subject variation, intraclass correlation, and concordance correlation were used to assess IIV for all parameters. Low variability with high reproducibility and high reliability was considered if CVw < 15% and ICC > 0.90, respectively. RESULTS: Analytical variability was low for all investigated parameters in technical replicates. IIV was assessed for basic semen parameters and proteins in SPs and EVs: 319 and 777 proteins, respectively, using untargeted analysis; 9 and 10 proteins using targeted quantification. We also described the IIV for sncRNA, including microRNA, piwi-interacting RNA, tRNA, and tRNA-derived small RNA (tsRNA) in EVs (409 sncRNA and 78 tsRNA) and in spermatozoa (265 sncRNA and 15 tsRNA). We identified 22 and 27 non-overlapping proteins in SP and EVs, respectively, and 46 and 9 sncRNA, including 5 and 0 tsRNA in seminal EVs and spermatozoa, respectively, with low variability. The fatty acid synthase (FAS) had the lowest IIV in both media in targeted protein quantification. DISCUSSION: We identified a number of proteins and sncRNA with low variability among 111 proteins, 176 sncRNA, and 12 tsRNA which were previously suggested as biomarkers of male fertility and reproductive outcomes: lactotransferrin, cysteine-rich secretory protein 3, alpha-1-antichymotrypsin, epididymal sperm-binding protein 1, glutathione S-transferase Mu 3, alpha-1-acid glycoprotein 2, serum amyloid P-component, aminopeptidase N, neprilysin, FAS, and miR-10b-3p, miR-122-5p, miR-205-5p, miR-222-3p, miR-34c-5p, miR-509-3-5p, miR-888-5p, miR-892a, miR-363-3p, miR-941, miR-146a-5p, miR-744-5p. CONCLUSION: These molecules have low IIV and may be promising candidate biomarkers of male fertility and reproductive health.

NaGaPO4F - a KTiOPO4-structured solid sodium-ion conductor.

Advanced ionic conductors are crucial for a large variety of contemporary technologies spanning solid state ion batteries, fuel cells, gas sensors, water desalination, etc. In this work, we report on a new member of KTiOPO4-structured materials, NaGaPO4F, with sodium-ion conductivity. NaGaPO4F has been obtained for the first time via a facile two-step synthesis consisting of a hydrothermal preparation of an ammonia-based precursor, NH4GaPO4F, followed by an ion exchange reaction with NaNO3. Its crystal structure was precisely refined using a combination of synchrotron X-ray powder diffraction and electron diffraction tomography. The material is thermally stable upon 450 °C showing no significant structural transformations or degradation but only a ∼1% cell volume expansion. Na-ion mobility in NaGaPO4F was investigated by a joint experimental and computational approach comprising solid-state nuclear magnetic resonance (NMR) and density functional theory (DFT). DFT and bond-valence site energy (BVSE) calculations reveal 3D diffusion of sodium in the [GaPO4F] framework with migration barriers amounting to 0.22 and 0.44 eV, respectively, while NMR yields 0.3-0.5 eV that, being coupled with a calculated bandgap of ∼4.25 eV, makes NaGaPO4F a promising fast Na-ion conductor.

Optimization of small RNA extraction and comparative study of NGS library preparation from low count sperm samples.

Recent studies demonstrate that sperm epigenome is a vehicle that conveys paternal experiences to offspring phenotype. That evidence triggers interest of both experimental and epidemiological studies of epigenetic markers in sperm. Since samples are often unique in epidemiological studies, a careful and efficient use of the material is a critical requirement. The goal of this study was to provide optimization of methods for the isolation of small RNAs from spermatozoa and library preparation for sequencing. A total 67 fractionated sperm samples from the Russian Children's Study biobank prospectively collected at 18-20 years of age were used to isolate small RNAs with median (IQR) input total sperm count 17.0 (7.4-35.9) million. Twenty-four pairs of libraries were prepared using the NEBNext and NEXTFlex kits, 19 libraries using NEBNext and 6 using NEXTFlex. All libraries were sequenced on NextSeq 500, and the results were evaluated as a function of the number of small non-coding RNA (sncRNA) detected, quality parameters of sequencing libraries, as well as technical features of sample preparation. Although the same amount of miRNA input was used for NEBNext and NEXTFlex libraries, the concentration of DNA in NEBNext libraries was significantly higher in comparison with NEXTFlex libraries. In high input (sperm count >28 million and more than 25 ng miRNA in library) NEXTFlex Small RNA-Seq kit detected more microRNAs. In low input, the NEBNext proved more effective. The tricks and traps to protocol optimization are presented, including an efficient and effector gel-based system for the removal of sequencing library adaptors.

Comparison of bioimpedance body composition in young adults in the Russian Children's Study.

BACKGROUND & AIMS: Body mass index is a simple anthropometric measure (kg/m2) used as an indirect estimate of body fat in individuals, and in assessments of population health and comparisons between populations. Bioelectrical impedance analysis (BIA) is often used to provide additional information on body fat and fat-free mass, and has been used to generate body composition reference data in national health surveys. However, BIA measurements are known to be device-specific and there are few published studies comparing results from different BIA instruments. Therefore, we compared the performance of two BIA instruments in the Russian Children's Study (RCS) of male growth, pubertal development and maturation. METHODS: Paired BIA measurements were obtained using the Tanita BC-418MA (Tanita Corp., Tokyo, Japan) and ABC-01 'Medas' (Medas Ltd, Moscow, Russia) BIA instruments. Cross-sectional data on 236 RCS subjects aged 18-22 years were used for the BIA comparison and the development of a conversion formula between measured resistances; follow-up data (n = 96) were used for validation of the conversion formula. RESULTS: Whole-body resistances were highly correlated (Spearman rho = 0.95), but fat mass (FM) estimates were significantly higher with the Medas than the Tanita device (median difference 3.3 kg, 95% CI: 2.9, 3.6 kg) with large limits of agreement (LoA) for the FM difference (-2.0, 8.6 kg). A conversion formula between the resistances (Res) was obtained: Medas Res = 0.882 × Tanita Res+26.2 (r2 = 0.91, SEE = 17.6 Ohm). After applying the conversion formula to Tanita data and application of the Medas assessment algorithm, the 'converted' Tanita FM estimates closely matched the Medas original estimates (median difference -0.1 kg, 95% CI: -0.3, 0.2 kg), with relatively small LoA for the FM difference (-2.3 to 2.1 kg), suggesting potential interchangeability of the ABC-01 'Medas' and Tanita BC-418MA data at the group level. CONCLUSIONS: Our results support the importance of cross-calibration of BIA instruments for population comparisons and proper data interpretation in clinical and epidemiological studies.

Coexistence of three types of sodium motion in double molybdate Na9Sc(MoO4)6: 23Na and 45Sc NMR data and ab initio calculations.

The rechargeable Na-ion batteries attract much attention as an alternative to the widely used but expensive Li-ion batteries. The search for materials with high sodium diffusion is important for the development of solid state electrolytes. We present the results of experimental and ab initio studies of the Na-ion diffusion mechanism in Na9Sc(MoO4)6. The ion conductivity reaches the value of 3.6 × 10-2 S cm-1 at T ∼ 850 K. The 23Na and 45Sc NMR data reveal the coexistence of three different types of Na-ion motion in the temperature range from 300 to 750 K. They are activated at different temperatures and are characterized by substantially different dynamics parameters. These features are confirmed by ab initio calculations of activation barriers for sodium diffusion along various paths.