Coherence of femtosecond single electrons exceeds biomolecular dimensions

Time-resolved diffraction and microscopy with femtosecond electron pulses provide four-dimensional recordings of atomic motion in space and time. However, the limited coherence of electron pulses, reported in the range of 2–3 nm, has so far prevented the study of complex organic molecules with relevance to chemistry and biology. Here we characterize the coherence of femtosecond single-electron pulses that are generated by laser photoemission. We show how the absence of space charge and the minimization of the source size allow the transverse coherence to be extended to 20 nm at the sample position while maintaining a useful beam diameter. The extraordinary coherence is experimentally demonstrated by recording singleelectron diffraction snapshots from a complex organic molecular crystal and identifying more than 80 sharp Bragg reflections. Further optimization affords promise for coherences of 100 nm. These advances will allow time-resolved imaging of functional dynamics in biological systems, uniting picometre and femtosecond resolutions in a compact, table-top instrumentation.publishe

Особенности формирования кадрового обеспечения профессиональных футбольных клубов на основе международного опыта (на примере Томской области)

Цель работы – оптимизировать процесс отбора игроков в системе кадрового обеспечения «ФК Томь». Актуальность работы данного исследования заключается в том, что опыт спортивной практики и экспериментальные исследования, посвященные методике спортивного отбора футболистов, требуют поиска новых, более эффективных методических путей. Теоретическая и практическая значимость работы: для эффективной работы системы кадрового обеспечения «ФК Томь», с целью сократить процесс отбора игрока с 30 дней до 16 дней, предлагается ввести в структуру организации селекционный отдел (скаут, тренер-селекционер). Предложенное решение основывается на анализе зарубежного опыта кадрового обеспечения иностранных футбольных клубов.Purpose of work - optimize the process of selection of players in the system of staffing "FC Tom." The relevance of the work of this study is that the experience of sports practice and experimental studies on the method of selection of sports players need to find new, more effective methodical ways. Theoretical and practical significance of the work: for the effective operation of the system of staffing "FC Tom", in order to reduce the player selection process from 30 days to 16 days, offered to enter into the structure of the organization of the selection department (scout). The proposed solution is based on the analysis of foreign experience in the staffing system of foreign football clubs

Stone clearance in lower pole nephrolithiasis after extra corporeal shock wave lithotripsy – the controversy continues

BACKGROUND: To determine factors influencing the clearance of fragments after extra-corporeal shock wave lithotripsy (ESWL) for lower pole calyceal (LPC) stones. METHODS: In the period between July 1998 and Oct 2001, 100 patients with isolated lower polar calyceal calculi ≤ 20 mm, in patients aged ≥ 14 years, were included in the study. Intravenous urograms (IVU) were reviewed to define the LPC anatomy (width of the infundibulum and pelvicalyceal angle). Study end points i.e. stone free status; number of shock waves used and number of sessions were correlated with variables like LPC anatomy, body mass index and stone size. RESULTS: At three months follow up the clearance for stone size ≤ 10 mm, 11–15 mm and 16–20 mm were 95, 96 and 90% respectively. Patients with acute LPC (<90°) and obtuse angle (>90°) had stone clearance of 94 and 100% respectively. For the infundibular width of < 4 mm, the stone clearance was 93% were as for > 4 mm, it was 100%. For body mass index (BMI) less than and > 30 kg/m(2), the stone clearance was 92 and 95% respectively. CONCLUSIONS: There is a trend towards more ESWL sessions and shock wave requirement in patients with acute pelvi-calyceal angle and narrow infundibulum but it is not statistically significant. Size (≤ 20 mm) and BMI has no relation with stone clearance. With modern lithotripter, stones up to 20 mm could primarily be treated by ESWL, irrespective of an un-favorable lower polar calyceal anatomy and body habitus

Factors impacting on menstrual hygiene and their implications for health promotion

BACKGROUND: In the lives of women, puberty is marked by the onset of menarche. From this stage onwards until menopause, reproductive health and menstrual hygiene are important aspects of women’s lives. In Zambia’s Western Province, the natural process of menstruation is a taboo and dealt with secretly. Information and knowledge about menstruation and menstrual hygiene among adolescent girls is inadequate. This paper explores the factors influencing the understanding, experiences and practices of menstrual hygiene among adolescent girls in Mongu District, Western Province of Zambia. METHODS: An explorative study design was used by means of six focus group discussions conducted with 51 respondents, aged 13–20 years, from three secondary schools. Their age at menarche was 11–15. For data analysis thematic content analysis was used. RESULTS: The paper shows that the girls suffer from poor menstrual hygiene, originating from lack of knowledge, culture and tradition, and socio-economic and environmental constraints, leading to inconveniences, humiliation and stress. This leads to reduced school attendance and poor academic performance, or even drop outs, and ultimately infringes upon the girls’ human rights. CONCLUSION: To address these shortcomings, a ‘super setting approach’ is recommended, in which a Health Promoting School could improve the girls’ individual and group needs, and a community setting which would address the broader socio-economic, cultural and environmental conditions. This would enable creating a supportive environment for the girls to manage their periods. To successfully utilize the approach, all stakeholders (parents, teachers, children, governments and communities) should cooperate to generate context-specific solutions for creating safe menstrual care, and better and dignified conditions for adolescent girls. Therefore, this calls for comprehensive, strident advocacy for policy changes at national level, and mediation and involvement at community level. (Global Health Promotion, 2018; 25(1): 54–62

Pediatric urolithiasis: the current surgical management

Children represent about 1% of all patients with urolithiasis, but 100% of these children are considered high risk for recurrent stone formation, and it is crucial for them to receive a therapy that will render them stone free. In addition, a metabolic workup is necessary to ensure a tailored metaphylaxis to prevent or delay recurrence. The appropriate therapy depends on localization, size, and composition of the calculus, as well as on the anatomy of the urinary tract. In specialized centers, the whole range of extracorporeal shock-wave lithotripsy (ESWL), ureterorenoscopy (URS), and percutaneous nephrolithotomy (PCNL) are available for children, with the same efficiency and safety as in adults