415 research outputs found
PF191012 Myszyniec - highest Orionid meteor ever recorded
On the night of Oct 18/19, 2012 at 00:23 UT a -14.7 mag Orionid fireball
occurred over northeastern Poland. The precise orbit and atmospheric trajectory
of the event is presented, based on the data collected by five video and one
photographic Polish Fireball Network (PFN) stations. The beginning height of
the meteor is 168.4 +\- 0.6 km which makes the PF191012 Myszyniec fireball the
highest ever observed, well documented meteor not belonging to the Leonid
shower. The ablation became the dominant source of light of the meteor at a
height of around 115 km. The thermalization of sputtered particles is suggested
to be the source of radiation above that value. The transition height of 115 km
is 10-15 km below the transition heights derived for Leonids and it might
suggest that the material of Leonids should be more fragile and have probably
smaller bulk density than in case of Orionids.Comment: 5 pages, 5 figures, accpeted for publication in Astronomy &
Astrophysic
16 Eskalowane hiperfrakcjonowanie w radioterapii nowotworów regionu głowy i szyi – 5-letnie wyniki leczenia
Cel pracyOcena 5-letnich wyników leczenia nowotworów regionu głowy i szyi w aspekcie wyleczalności miejscowej i późnych powikłań popromiennych.Materiał i metodykaW latach 1988–1992 w Centrum Onkologii-Instytucie w Gliwicach leczono promieniami wg systemu eskalowanego Hiperfrakconowania 48 chorych na płaskonabtonkowego raka jamy ustnej (34 pts), garłta środkowego (11 pts) i krtani (3 pts). U 4 chorych kliniczne zaàwansowanie raka ocenionego jako stopień T1, u 27 na T2 i u 2 na T4; u czterechnie moźna było określićc zaawansowania – TX.U wszystkich chorych radioterapia była jedynym leczeniem, a jego technika polegała na napromienianiu dwóch pól boznych na przeciwległych. W pierwszym etapie chorzy otrzymywali dawkę 32 Gy w 20 frakcjach po 1,6 Gy (2×1,6 Gy/ tydzień), wyłąctczają soboty i niedziele. Eskalacja dawki – co drugi dzień leczenia o 0,2 Gy/dzień – następowała po planowanej przerwie (po dawce 32 Gy). Dawka całkowita mieściła się w zakresie 62,2 – 74 Gy.WynikiPomimo stosunkowo wysokiego odsetka całkowitych regresji zanotowanych bezpośrednio po zakończeniu leczenia (75%), 5-letnia wyleczalnoąć miejscowa w całej grupie pacjentów wyniosła 58% i w zależności od stopnia zawansowania przedstawia się następująco: 100% dla T1 i TX, 55% dla T2, 45% dla T3 i 0% dla T4. Przebieg ostrego odczynu popromiennego był u większości chorych znacznie bardziej nasilony w porównaniu do typowego odczynu występujątcego przy konwencjonalnym napromienianiu. U wszystkich pacjentów wystątPiło rozlane popromienne zapalenie błony śluzowej, a jego przebieg w zwiątzku z obecnościąt przerwy był dwufazowy.WnioskiZastosowanie eskalowanego hiperfrakcjonowania w radioterapii nowotworów regionu głowy i szyi nie przyniosło poprawy wyników leczenia w porównaniu do konwencjonalnych schematów napromieniania.Możliwe przyczyny takiego wyniku to: dłuzsza niż zaplanowana przerwa pomiędzy dwoma etapami leczenia, jej umiejscowienie (w 13 dniu od rozpoczęcia radioterapii), ryzyko błędu geograficznego w drugiej (eskalowanej) części leczenia
The activity and immunoexpression of cathepsin D in rat male reproductive organs
Cathepsin D is a cysteine endopeptidase that belongs to the lysosomal enzyme
family. The aim of the study was to evaluate the enzyme immunoexpression and
activity in selected male genital organs in mature Wistar rats. The activity of
cathepsin D was measured spectrophotometrically in homogenates of the testis,
epididymis, seminal vesicle and prostate. Immunohistochemical staining was
also performed in the ductus deferens. Enzyme activity was found in the following
sequence: testis>epididymis>dorsal prostatic lobe>seminal
vesicle>lateral prostatic lobe>ventral prostatic lobe. Although there were differences
in enzyme activity between various organs of the male reproductive
system, cathepsin D immunoreactivity was seen exclusively in the Sertoli and
Leydig cells in the testis
What do clinicians think of the anatomical knowledge of medical students? Results of a survey
Human anatomy is one of basic courses in medical education. It usually takes place during the first year of the medical school syllabus. However, the results of the course, if defined as profound anatomical knowledge, are not applied by the students until several years after the final anatomy examination. The aim of the study was to evaluate the anatomical knowledge of senior medical students. For this reason a survey was distributed among teachers responsible for clinical rotas. The results of the study were intended to give the answer to the question, "What do students remember several years after the anatomy examination?" as expressed by their clinical teachers. The
questionnaire included four closed questions and one open question. The closed questions concerned general anatomical knowledge, whether the anatomy course should be extended and whether additional courses should be introduced and included a question about student knowledge of particular systems. The open question concerned ways of improving anatomical education.
As a result of the survey it was observed that surgical specialists had a significantly lower opinion of the medical knowledge of their students than had medical specialists. Most of the suggestions for improving anatomical education were related to introducing clinical applications of anatomical knowledge
UVSat: a concept of an ultraviolet/optical photometric satellite
Time-series photometry from space in the ultraviolet can be presently done
with only a few platforms, none of which is able to provide wide-field
long-term high-cadence photometry. We present a concept of UVSat, a twin space
telescope which will be capable to perform this kind of photometry, filling an
observational niche. The satellite will host two telescopes, one for
observations in the ultraviolet, the other for observations in the optical
band. We also briefly show what science can be done with UVSat.Comment: 6 pages, 2 figures, accepted for publication in the Proceedings of
the PAS (Proc. of the 2nd BRITE Science conference, Innsbruck
Photochemical properties of the cyclopentadienyliron complex of phenothiazine
Publisher's version/PDFPhotolysis of [([eta superscript 6]-phenothiazine)([eta superscript 5]-cyclopentadienyl)]iron(II) hexafluorophosphate (1) has been examined in various solvents such as MeOH, DMSO, THF, MeCN, furan, CH[subscript 2]Cl[subscript 2], CF[subscript 3]CH[subscript 2]OH and (CF[subscript 3])[subscript 2]CHOH. Photoreactions are induced by excitation at [lambda] = 254, 313, 337, 366, 514.5 and 647.5 nm. The major reaction leads to the photorelease of phenothiazine (2) which does not react further under the reaction conditions. Quantum yields of photolysis of 1, [phi](1), and photorelease of 2, [phi]([subscript 2]), are independent of concentration in the range of 1 × 10[superscript –4]–1 × 10[superscript–2] mol dm[superscript–3], wavelength of excitation and light intensity and in MeOH, MeCN, furan and THF, [phi]([subscript 1]) = [phi]([subscript 2]) = ca. 1. The quantum yields are lower in solvents of lower nucleophilicity and in CH[subscript 2]Cl[subscript 2], CF[subscript 3]CH[subscript 2]OH and (CF[subscript 3])[subscript 2]CHOH the [phi]([subscript 1]) values are 0.45, 0.26 and 0.03, respectively. In some solvents ferrocene formation is also observed. Applying oxygen as a quencher it is found that photochemical decay of 1 takes place from the excited state [superscript 3]E[subscript 1], with a lifetime of [tau][subscript 3][Epsilon][subscript 1] < 10[superscript –8]s and leads to formation of 2
YETI observations of the young transiting planet candidate CVSO 30 b
CVSO 30 is a unique young low-mass system, because, for the first time, a
close-in transiting and a wide directly imaged planet candidates are found
around a common host star. The inner companion, CVSO 30 b, is the first
possible young transiting planet orbiting a previously known weak-lined T-Tauri
star. With five telescopes of the 'Young Exoplanet Transit Initiative' (YETI)
located in Asia, Europe and South America we monitored CVSO 30 over three years
in a total of 144 nights and detected 33 fading events. In two more seasons we
carried out follow-up observations with three telescopes. We can confirm that
there is a change in the shape of the fading event between different
observations and that the fading event even disappears and reappears. A total
of 38 fading event light curves were simultaneously modelled. We derived the
planetary, stellar, and geometrical properties of the system and found them
slightly smaller but in agreement with the values from the discovery paper. The
period of the fading event was found to be 1.36 s shorter and 100 times more
precise than the previous published value. If CVSO 30 b would be a giant planet
on a precessing orbit, which we cannot confirm, yet, the precession period may
be shorter than previously thought. But if confirmed as a planet it would be
the youngest transiting planet ever detected and will provide important
constraints on planet formation and migration time-scales.Comment: 14 pages (20 with appendix), 7 figures (16 with appendix), 6 tables
(7 with appendix
- …