Validation of the Polish version of the Johns Hopkins Learning Environment Scale-a confirmatory factor analysis.

The Johns Hopkins Learning Environment Scale (JHLES) was developed by Robert B. Shochet, Jorie M. Colbert and Scott M. Wright of the Johns hopkins university school of medicine and consists of 28 items used to evaluate perception of the academic environment. The objective was to translate and adapt the JHLES to Polish cultural conditions and to validate the Polish version of the tool. The JHLES questionnaire was completed by students of all years (first-fifth) of the faculties of dental medicine at the Medical University of Lublin and the Medical University of Gdansk. The total surveyed population consisted of 597 students. The overall reliability of the tool was excellent. Confirmatory factor analysis was performed in order to confirm structural consistency with the original JHLES tool. Consequently, all indices had acceptable values (close to 1 or 0, depending on the case), and there was consistency in the results, which shows that the JHLES model is supported by the data. In the present study, the JHLES has been validated in a sample of dental students for the first time in Poland and Europe. Our study provided good evidence for the reliability and validity of the Polish version of the JHLES. In conclusion, the Polish-language version of the JHLES questionnaire is a reliable and valid instrument for analysing the learning environment for students, and its factor structure is supported by the data.

Validation of the Polish version of the DREEM questionnaire - a confirmatory factor analysis.

AIM: The aim of our study was to translate and adapt the Dundee Ready Education Environment Measure (DREEM) questionnaire developed by Roff et al. to the cultural conditions in Poland and also to validate it. Studying the learning environment is beneficial because it can identify students' perceptions of their environment and support the staff in reflecting on, planning for and combining proper teaching approaches to improve it. METHODS: The DREEM questionnaire was completed by students of all years (first-fifth) in the faculties of dental medicine at the Medical University of Lublin and the Medical University of Gdansk. The total surveyed population consisted of 650 students. Validity was separated into four phases: (1) translation validity, (2) confirmatory factor analysis, (3) concurrent validity and (4) criterion-related validity. RESULTS: Our study confirmed the original structure of the DREEM tool (GFI = 0.955, AGFI = 0.951, NFI = 0.931, TLI = 0.962, CFI = 0.964, RNI = 0.964, IFI = 0.964, RFI = 0.928, PNFI = 0.885, SRMR = 0.062, RMSEA = 0.043, 90% CI = 0.041-0.046) and obtained very good reliability rates, with Cronbach's alpha > 0.7 for all scales. Only Subscale V achieved a lower Cronbach's alpha of > 0.5. The study was conducted using the test-retest method, which is why the intraclass correlation coefficients for reliability were also calculated; individual items showed both medium and good correspondence. CONCLUSIONS: Our study provided good evidence for the reliability and validity of the Polish version of the DREEM. In conclusion, the Polish-language version of the DREEM questionnaire is a reliable and valid instrument for analysing the learning environment for dental students and its factor structure is supported by the data.

3D Characterization of the Molecular Neighborhood of •OH Radical in High Temperature Water by MD Simulation and Voronoi Polyhedra.

Understanding the properties of the •OH radical in aqueous environments is essential for biochemistry, atmospheric chemistry, and the development of green chemistry technologies. In particular, the technological applications involve knowledge of microsolvation of the •OH radical in high temperature water. In this study, the classical molecular dynamics (MD) simulation and the technique based on the construction of Voronoi polyhedra were used to provide 3D characteristics of the molecular vicinity of the aqueous hydroxyl radical (•OHaq). The statistical distribution functions of metric and topological features of solvation shells represented by the constructed Voronoi polyhedra are reported for several thermodynamic states of water, including the pressurized high-temperature liquid and supercritical fluid. Calculations showed a decisive influence of the water density on the geometrical properties of the •OH solvation shell in the sub- and supercritical region: with the decreasing density, the span and asymmetry of the solvation shell increase. We also showed that the 1D analysis based on the oxygen-oxygen radial distribution functions (RDFs) overestimates the solvation number of •OH and insufficiently reflects the influence of transformations in the hydrogen-bonded network of water on the structure of the solvation shell.

Predictors of stress among dentists during the COVID-19 epidemic.

The aim of the study was to assess the relationship between personality traits, self-esteem and life satisfaction, and also the stress level, among dentists during the COVID-19 outbreak. In order to confirm our hypotheses, 310 active dentists aged 25-64 years who were practising during the first wave of COVID-19 in Poland were examined. The IPIP-BFM-20 self-report questionnaire was used to measure personality traits, the popular Rosenberg Self-Esteem Scale was used to assess self-esteem, the five-item Satisfaction with Life Scale was used to measure life satisfaction and the four-item version of the Perceived Stress Scale was used to measure stress. The dependent variable-stress-correlates negatively with traits in relation to the dimensions of extraversion (r = -0.17, p < 0.01), emotional stability (r = -0.35, p < 0.01) and intellect (r = -0.16, p < 0.01); it also has a negative correlation with self-esteem (r = -0.37, p < 0.01) and life satisfaction (r = -0.35, p < 0.01). Among the analysed variables, the highest correlations are observed for the following: self-esteem and emotional stability (r = 0.51, p < 0.01); self-esteem and life satisfaction (r = 0.49, p < 0.01); extraversion and intellect (r = 0.47, p < 0.01). Considering the measures of mediation relevance and pathway relevance, it can be assumed that both self-esteem and life satisfaction have a mediating function in the relationship between agreeableness, emotional stability and stress: the relationship between emotional stability and stress is negative whereas that between agreeableness and stress is positive.

The Norwegian childhood cancer biobank.

BACKGROUND: The rapidly expanding era of "omics" research is highly dependent on the availability of quality-proven biological material, especially for rare conditions such as pediatric malignancies. Professional biobanks provide such material, focusing on standardized collection and handling procedures, distinctive quality measurements, traceability of storage conditions, and accessibility. For pediatric malignancies, traditional tumor biobanking is challenging due to the rareness and limited amount of tissue and blood samples. The higher molecular heterogeneity, lower mutation rates, and unique genomic landscapes, however, renders biobanking of this tissue even more crucial. AIM: The aim of this study was to test and establish methods for a prospective and centralized biobank for infants, children, and adolescents up to 18 years of age diagnosed with cancer in Norway. METHODS: Obtain judicial and ethical approvals and administration through a consortium, steering committee, and advisory board. Develop pipelines including SOPs for all aspects in the biobank process, including collection, processing and storing of samples and data, as well of quality controlling, safeguarding, distributing, and transport. RESULTS: The childhood cancer biobanking started at Oslo University Hospital in March 2017 and was from 2019 run as a national Norwegian Childhood Cancer Biobank. Informed consent and biological samples are collected regionally and stored centrally. Approximately 12 000 samples from 510 patients and have been included by January 1, 2021, representing a 96% consent and participation rate among our newly diagnosed patients. CONCLUSION: A well-functioning nationwide collection and centralized biobank with standardized procedures and national storage for pediatric malignancies has been established with a high acceptance among families.

How the Duration and Mode of Photopolymerization Affect the Mechanical Properties of a Dental Composite Resin.

Composite materials are the most common materials in use in modern dentistry. Over the years, the methods of photopolymerization of composite materials have been improved with the use of various devices, such as quartz tungsten halogen lamps (QTHs), light-emitting diode units (LEDs), plasma-arc lamps and argon-ion lasers. This study aimed to compare the mechanical properties of a composite material, depending on the time and mode of photopolymerization. One hundred and forty rectangular specimens (25 × 2 × 2 mm) and forty-two disc-shaped samples (5 mm diameter and 2 mm thickness) were prepared from shade A2 Boston composite resin. Samples were cured using the following seven photopolymerization protocols: four fast-cure modes (full power for 3, 5, 10, and 20 s), two pulse-cure modes (5 and 10 shots of 1 s exposures at full power), and one step-cure mode (soft start with a progressive cycle lasting 9 s). Specimens were subjected to a flexural strength test, Vickers microhardness test, and FTIR spectroscopy test. A 2-factor ANOVA and post-hoc tests were carried out to assess the differences in the flexural strength parameter between the tested groups of samples before and after aging. A mixed-model ANOVA was carried out to assess the differences in the Vickers microhardness parameter between the tested groups of samples before and after aging. The lowest values of flexural strength (p < 0.001) and Vickers microhardness (p < 0.001) were obtained for the 3 s mode for the pre- and post-aging groups. The FTIR mapping tests showed a much more homogeneous chemical structure of the composite after 20 s of continuous irradiation, compared to the sample irradiated for 5 s in the continuous mode. The mode and cure time affects the mechanical properties of the composite resin. Appropriate selection of the cure mode and time ensures better mechanical properties of composite resin. This suggests that the survival of dental restorations within the oral cavity could be extended by using longer photopolymerization durations.

Microstructure and In Vitro Evaluation of Extruded and Hot Drawn Alloy MgCa0.7 for Biodegradable Surgical Wires.

The MgCa0.7 alloy may be a promising material for biodegradable surgical wires. In this paper, the technology for producing surgical wires from this alloy has been developed, based both on finite element modelling and experimental study. In particular, the extrusion and hot-drawing effects on the mechanical properties, microstructures, in-vitro rates of biocorrosion, and cytotoxicity to human cancer cells (SaOS-2) and healthy (hPDL) ones, have been determined. An approximately 30-40% increase in corrosion rate due to increasing hot-drawing temperature was observed. An effect of hot-drawing temperature on cytotoxicity was also found. Notably, at various stages of the final wires' production, the MgCa0.7 alloy became toxic to cancer cells. This cytotoxicity depended on the alloys' processing parameters and was maximal for the as-extruded rod and for the wires immediately after hot drawing at 440 °C. Thus, the careful selection of processing parameters makes it possible to obtain a product that is not only a promising candidate for biodegradable surgical wires, but one which also has intrinsic bioactive properties that produce antitumor activity.

Dynamics of Ion Pairing in Dilute Aqueous HCl Solutions by Spectroscopic Measurements of Hydroxyl Radical Conversion into Dichloride Radical Anions.

The rate of formation of dichloride anions (Cl2•-) in dilute aqueous solutions of HCl (2-100 mmol·kg-1) was measured by the technique of pulse radiolysis over the temperature range of 288-373 K. The obtained Arrhenius dependence shows a concentration averaged activation energy of 7.3 ± 1.8 kJ·mol-1, being half of that expected from the mechanism assuming the •OHCl- intermediate and supporting the ionic equilibrium-based mechanism, i.e., the formation of Cl2•- in the reaction of •OH with a hydronium-chloride (Cl-·H3O+) contact ion pair. Assuming diffusion-controlled encounter of the hydronium and chloride ions and including the effect of the ionic atmosphere, we showed that the reciprocal of τ, the lifetime of (Cl-·H3O+), follows an Arrhenius dependence with an activation energy of 23 ± 4 kJ·mol-1, independent of the acid concentration. This result indicates that the contact pair is stabilized by hydrogen bonding interaction of the solvent molecules. We also found that at a fixed temperature, τ is noticeably increased in less-concentrated solutions (mHCl < 0.01 m). Since this concentration effect is particularly pronounced at near ambient temperatures, the increasing pair lifetime may result from the solvent cage effect enhanced by the presence of large supramolecular structures (patches) formed by continuously connected four-bonded water molecules.

Flow cytometric analysis of cerebrospinal fluid improves detection of leukaemic blasts in infants with acute lymphoblastic leukaemia.

Infants with acute lymphoblastic leukaemia (ALL) have a high frequency of central nervous system (CNS) involvement. Flow cytometric analysis of cerebrospinal fluid (CSF) was recently demonstrated to be a sensitive method for detecting CNS involvement in childhood ALL. In the present study, CSF from 14 infants was collected at routine lumbar punctures and analysed by multicolour flow cytometry. At initial diagnosis, leukaemic blasts were detected in CSF by flow cytometry in 11 patients (78·6%) compared to seven patients (50%) by cytospin. Larger studies are needed to determine if CSF flow cytometry has prognostic value in infant ALL.

The Influence of Popular Beverages on Mechanical Properties of Composite Resins.

Currently, composite resins are used in many restorative procedures. Previous studies showed that drinking beverages may affect the mechanical properties such as microhardness or flexural strength of dental composite resins. The aim of the present study was to investigate the influence of common beverages on the mechanical properties of composite resins. Samples of the materials were prepared according to the ISO 4049:2010 standard and producer's recommendations. The samples were next conditioned in tested fluids: distilled water, sparkling water, Coca-Cola, Red Bull and orange juice for 7 days. Vickers microhardness and flexural strength testing was performed after 7 days. Performed statistic tests confirmed the significance of microhardness changes of the tested materials in terms of both different conditioning of the samples and different composite materials. The mean flexural strength of composites was highest in distilled water and it was reduced after one week in different beverages. We conclude that all tested beverages influenced on Vickers microhardness of tested composite resins. Flexural strength only in one material was statistically significantly influenced by tested beverages. The results of this study should be taken into consideration by a dentist preparing recommendations for the patients after dental treatment with usage of composite material or after cementing composite based fixed dentures.

Water-Triggered Photoinduced Electron Transfer in Acetonitrile-Water Binary Solvent. Solvent Microstructure-Tuned Reactivity of Hydrophobic Solutes.

The solvent-composition dependence of quenching triplet states of benzophenone (3BP) by anisole in acetonitrile-water (ACN-H2O) mixtures was investigated by laser flash photolysis over the water mole fraction (xw) increasing from 0 to 0.92. Single exponential decay of 3BP was observed over the whole composition range. The quenching rate constant consistently increased with the water content but increased far more rapidly with xw > 0.7. The water-triggered electron-transfer (ET) mechanism was confirmed by a steeply growing quantum yield of the benzophenone ketyl radical anion, escaping back-ET when the partial water volume exceeded the acetonitrile one. The water-content influence on the 3BP quenching rate was described by a kinetic model accounting for the microheterogeneous structure of the ACN-H2O mixtures and the very different solubility of the reactants in the solvent components. According to the model, the ET mechanism occurs at a rate constant of 1.46 × 109 M-1 s-1 and is presumably assisted by the ACN-H2O hydrogen-bonding interaction.

Craniofacial Morphology in Children with Growth Hormone Deficiency and Turner Syndrome.

The review aims to collect and demonstrate recent knowledge about craniofacial morphology in growth hormone (GH)-deficient children and children with Turner syndrome. The review describes also the effects of growth hormone treatment on craniofacial morphology of children with growth hormone deficiency and Turner syndrome. Regardless of the disorder it accompanies, short stature is associated with similar craniofacial features characteristic of all short-statured children. Characteristic craniofacial features involve lesser dimensions of the cranial base and mandibular length, proportionately smaller posterior than anterior facial height, retrognathic face, and posterior rotation of the mandible. We also analyze orthodontic treatment in children affected by disorders associated with GH deficiency or provided with growth hormone treatment in the aspect of craniofacial growth. Recent publications show also the connection between growth hormone receptor polymorphism and craniofacial growth. Specialists and orthodontists treating short-statured children must be aware of the results of studies on craniofacial morphology and educate themselves on the topic of craniofacial growth in children with short stature. Moreover, knowledge of the influence of GH therapy on growth of craniofacial structures is necessary to decide the proper timing and planning of orthodontic treatment.

Vitamin D3 and Dental Caries in Children with Growth Hormone Deficiency.

Vitamin D deficiency is a common risk factor for multifactorial diseases, and it seems to be associated with growth hormone deficiency (GHD). Vitamin D could prevent dental caries. The goal of this study was to identify whether there is an association between hormonal therapy with growth hormone (GH), vitamin D3 supplementation, vitamin D3 levels, and the occurrence of caries among children affected by GHD. The study group consisted of patients from the Department of Endocrinology and Diabetology of the University Paediatric Hospital at the Medical University of Lublin treated with recombinant human GH for pituitary GHD. It was conducted between October 2014 and June 2015. The study group included 121 children and adolescents aged 6 to 18 years, with 56 children from rural areas and 65 from urban areas. The study group was stratified by the area of residence. We found the statistically significant impact of vitamin D3 concentration on the average value of the DMFT (decayed, missed, and filled teeth) index and its component-DT (decayed teeth), which was noted in subjects from rural areas. Among patients from urban areas, we found a statistically significant correlation between duration of therapy and the DMFT index. An increase in duration of GH therapy by 10 months leads to a mean increase in DMFT index by 0.70. Based on multiple regression analysis, we developed the following model: value of DT = 3.10 - 0.73∗category of vitamin D3 concentration - 0.07∗duration of supplementation (in months). In this model, variables with a significant impact on the value of DT in the group of patients from rural areas include time of vitamin D3 supplementation and category of vitamin D3 concentration. Greater emphasis should be placed on promoting vitamin D3 as a potentially effective agent reducing the number of dental caries, especially among patients with GHD.

Ionic-Equilibrium-Based Mechanism of •OH Conversion to Dichloride Radical Anion in Aqueous Acidic Solutions by Kinetic and Theoretical Studies.

A new mechanism for the dichloride radical anion (Cl2•-) formation in diluted acidic chloride solutions is proposed on the grounds of pulse radiolysis measurements of the optical absorption growth at 340 nm and the density functional theory and Hartree-Fock computations. We show that the rate of •OH conversion into Cl2•- is determined by the equilibrium concentration of the ionic pair H3O+·Cl-. According to the proposed mechanism, the diffusional encounter of •OH and H3O+·Cl- is followed by fast concerted charge/proton transfer ( k(25 °C) = 6.2 × 1012 s-1) to yield Cl•, which then reacts with Cl- to produce Cl2•-. The mechanism has been confirmed by the observed first-order growth of the Cl2•- absorption and a direct proportionality of the rate constant to the activities of H3O+ and Cl- ions. The salt effect on the rate of Cl2•- formation is due to the ionic strength effect on the equilibrium H3O+ + Cl- ⇄ H3O+·Cl-.

Dental caries and vitamin D3 in children with growth hormone deficiency: A STROBE compliant study.

Vitamin D may prevent dental caries. To date, no attempts have been made to examine the correlation between the incidence of caries and the concentrations of vitamin D in children with pituitary growth hormone deficiency.The study observed patients of the Department of Endocrinology and Diabetology of the University Paediatric Hospital of the Medical University of Lublin treated with human recombinant growth hormone for pituitary growth hormone deficiency (GHD). The study was conducted between October 2014 and June 2015. The study group consisted of 121 children and adolescents (6-17 years old), including 56 children from rural areas and 65 children from urban areas. The study group was stratified by area of residence.In our study, the increase in vitamin D3 [25(OH)D] levels reduced the D component by 0.66 per each 10 ng/mL of vitamin D3 concentration. The percentage of children with active caries in rural areas is 91.07% (n = 51), which is significantly higher than the percentage of children with active caries in urban areas (81.54%, n = 53).To date, information regarding the potential possibility of reducing the incidence of dental caries by means of increasing the levels of vitamin D was sidelined by paediatricians and dentists alike. Therefore, this aspect of caries prevention should be highlighted.

Recovery of Lemna minor after exposure to sulfadimethoxine irradiated and non-irradiated in a solar simulator.

Sulfonamides are the second most widely used group of veterinary antibiotics which are often detected in the environment. They are eliminated from freshwaters mainly through photochemical degradation. The toxicity of sulfadimethoxine (SDM) was evaluated with the use of Lemna minor before and after 1- and 4-h irradiation in a SunTest CPS+ solar simulator. Eight endpoints consisting of: number and total area of fronds, fresh weight, chlorophylls a and b, carotenoids, activity of catalase and guaiacol peroxidase, and protein content were determined. The total frond area and chlorophyll b content were the most sensitive endpoints with EC50 of 478 and 554 µg  L-1, respectively. The activity of guaiacol peroxidase and catalase increased at SDM concentrations higher than 125 and 500 µg  L-1, respectively. The SDM photodegradation rate for first order kinetics and the half-life were 0.259 h-1 and 2.67  h, respectively. The results show that the toxicity of irradiated solutions was caused by SDM only, and the photoproducts appeared to be either non-toxic or much less toxic to L. minor than the parent compound. To study the recovery potential of L. minor, after 7 days exposure in SDM solutions, the plants were transferred to fresh medium and incubated for the next 7 days. L. minor has the ability to regenerate, but a 7-day recovery phase is not sufficient for it to return to an optimal physiological state.

[Correlation between generalized joint laxity and symptoms of temporomandibular disorders]. / Zwiazek miedzy wystepowaniem uogólnionej wiotkosci stawowej oraz zaburzen czynnosciowych ukladu ruchowego narzadu zucia.

UNLABELLED: Generalized joint hypermobility (GJH) is an increase of joints mobility over accepted norms. Many authors include GJH to etiologic factors of temporomandibular disorders (TMD). AIM: The aim of the study was to verify if there is an association between GJH and TMD. MATERIAL AND METHODS: Study was performed on 126 subjects (95 females and 31 males) aged 12-46 years. In order to find signs and symptoms of TMD Polish version of RDC/TMD questionnaire was used. GJH was assessed using Beighton's scale. Using r-Pearson's correlation an association between GHJ and TMD signs and symptoms was verified. RESULTS: No statistically significant association between TMD sings and symptoms and GJH was found. CONCLUSIONS: Presence of GJH is not associated with TMD signs and symptoms (in group of young adults).

Radiation therapy and concurrent topotecan followed by maintenance triple anti-angiogenic therapy with thalidomide, etoposide, and celecoxib for pediatric diffuse intrinsic pontine glioma.

BACKGROUND: Despite major treatment attempts, the prognosis for pediatric diffuse intrinsic pontine gliomas (DIPGs) remains dismal. Gliomas are highly vascularized tumors, suggesting that the prevention of vessel formation by anti-angiogenic treatment might be effective. PROCEDURE: Forty-one pediatric patients with DIPG were treated according to the Angiocomb protocol, starting with radiotherapy combined with topotecan and followed by anti-angiogenic triple medication consisting of thalidomide, etoposide, and celecoxib. Overall survival, radiological response, quality of life, requirement of corticosteroids, and adverse effects were monitored. Eight patients treated with only radiotherapy were used as controls. RESULTS: For study patients, the 12 and 24 months overall survival was 61% and 17%, respectively. The median overall survival was 12 months (range 4-60 months). Four radiological complete responses were seen, of which two were transient. Radiologically, 56% of the tumors reduced in size and 78% in signal intensity. Study patients were able to visit school or daycare and walk for a significantly longer time compared to controls (Log Rank 0.036 and 0.008, respectively). Adverse effects were generally minor. CONCLUSIONS: The Angiocomb protocol created a noticeable share of long-term survivors and was well tolerated, suggesting that anti-angiogenic therapy for patients with DIPG should be studied more in the future.

Mechanism of OH radical hydration: a comparative computational study of liquid and supercritical solvent.

Flexible models of the radical and water molecules including short-range interaction of hydrogen atoms have been employed in molecular dynamic simulation to understand mechanism of (●)OH hydration in aqueous systems of technological importance. A key role of H-bond connectivity patterns of water molecules has been identified. The behavior of (●)OH(aq) strongly depends on water density and correlates with topological changes in the hydrogen-bonded structure of water driven by thermodynamic conditions. Liquid and supercritical water above the critical density exhibit the radical localization in cavities existing in the solvent structure. A change of mechanism has been found at supercritical conditions below the critical density. Instead of cavity localization, we have identified accumulation of water molecules around (●)OH associated with the formation of a strong H-donor bond and diminution of non-homogeneity in the solvent structure. For all the systems investigated, the computed hydration number and the internal energy of hydration Δ(h)U showed approximately linear decrease with decreasing density of the solvent but a degree of radical-water hydrogen bonding exhibited non-monotonic dependence on density. The increase in the number of radical-water H-acceptor bonds is associated with diminution of extended nets of four-bonded water molecules in compressed solution at ~473 K. Up to 473 K, the isobaric heat of hydration in compressed liquid water remains constant and equal to -40 ± 1 kJ mol(-1).

Molecular dynamics study of the hydration of the hydroxyl radical at body temperature.

Classical molecular dynamics (MD) simulation of ˙OH in liquid water at 37 °C has been performed using flexible models of the solute and solvent molecules. We derived the Morse function describing the bond stretching of the radical and the potential for ˙OH-H(2)O interactions, including short-range interactions of hydrogen atoms. Scans of the potential energy surface of the ˙OH-H(2)O complex have been performed using the DFT method with the B3LYP functional and the 6-311G(d,p) basis set. The DFT-derived partial charges, ±0.375e, and the equilibrium bond-length, 0.975 Å, of ˙OH resulted in the dipole moment of 1.76 D. The radical-water radial distribution functions revealed that ˙OH is not built into the solvent structure but it rather occupies distortions or cavities in the hydrogen-bonded network. The solvent structure at 37 °C has been found to be the same as that of pure water. The hydration cage of the radical comprises 13-14 water molecules. The estimated hydration enthalpy -42 ± 5 kJ mol(-1) is comparable with the experimental value -39 ± 6 kJ mol(-1) for 25 °C. Inspection of hydrogen bonds showed the importance of short-range interaction of hydrogen atoms and indicated that neglect of the angular condition greatly overestimates the number of the H-acceptor radical-water bonds. The mean number ̅n = 0.85 of radical-water H-bonds has been calculated using geometric definition of H-bond and ̅n = 0.62 has been obtained when the energetic condition, E(da)≤-8 kJ mol(-1), was additionally considered. The continuous lifetimes of 0.033 ps and 0.024 ps have been estimated for the radical H-donor and the H-acceptor bonds, respectively. Within statistical uncertainty the radical self-diffusion coefficient, (2.9 ± 0.6) × 10(-9) m(2) s(-1), is the same as (3.1 ± 0.5) × 10(-9) m(2) s(-1) calculated for water in solution and in pure solvent. To the best of our knowledge, this is the first study of the ˙OH(aq) properties at a biologically relevant body temperature.