34 research outputs found
Luminescence of Agrellite Specimen from the Kipawa River Locality
Using steady-state luminescence measurements, the luminescence spectra of Ce3+, Pr3+,
Nd3+, Sm3+, Eu3+, Dy3+, Er3+ and Yb3+ for the agrellite sample from the Kipawa River region have
been measured. The emission spectra of Eu3+ and Dy3+ next to those of Sm3+ and Pr3+ have been
measured for characteristic excitation conditions. The most efficient luminescence activator in the
studied sample was Ce3+. This ion was also a sensitizer of Pr3+, Sm3+, Eu3+, and Dy3+ luminescence
Neoadjuvant treatment in a patient with HER2-positive breast cancer — a case study and review of recent recommendations
Leczenie przedoperacyjne (neoadiuwantowe czy indukcyjne) w przebiegu raka piersi jest zarezerwowane dla miejscowo zaawansowanych guzów pierwotnie operacyjnych (leczenie neoadiuwantowe) lub pierwotnie nieoperacyjnych — w celu osiągnięcia operacyjności (leczenie indukcyjne). Leczenie to ma zastosowanie we wszystkich fenotypach raka piersi. Największą korzyść z leczenia przedoperacyjnego odnoszą chore z potrójnie ujemnym rakiem piersi (TNBC) lub z HER2 dodatnim (nadekspresja bądź amplifikacja genu receptora ludzkiego naskórkowego czynnika wzrostu typu 2). W tej grupie pacjentek najczęściej uzyskuje się całkowitą odpowiedź potwierdzoną patologicznie (pCR), co przekłada się na poprawę rokowania. W niniejszej pracy przedstawiono przypadek chorej z całkowitą regresją guza pierwotnego po indukcyjnej chemioterapii w skojarzeniu z trastuzumabem (obecnie wskazanie nierefundowane w Polsce) oraz przegląd piśmiennictwa poświęconego temu zagadnieniu.Pre-operative breast cancer therapy (neoadjuvant or induction) is reserved for patients with locally advanced tumours primarily amenable to surgery (neoadjuvant treatment) or subjects with initially unresectable disease in whom respectability may be achieved following upfront systemic treatment (induction therapy). Initial systemic treatment may be used in all phenotypes of breast cancer. Patients with “triple-negative” breast cancer (TNBC) or human epidermal growth factor receptor 2 (HER-2)-positive tumours benefit most from preoperative therapy. Patients in this group most often achieve pathological complete response (pCR), which results in an improved prognosis. In this report, we present a case of complete tumour regression following neoadjuvant chemotherapy combined with trastuzumab (currently a non-reimbursed indication in Poland) and we review the literature on this issue
The absorption- and luminescence spectra of Mn3+ in beryl and vesuvianite
This research project was supported by the Polish National Science Centre (Grant DEC-2011/03/B/ ST10/06320) and by statutory funding from the Faculty of Earth Sciences at the University of Silesia. Dr. Padhraig S. Kennan (University College Dublin, Ireland) is thanked for help with language.The electron absorption-, photoluminescence- and electron paramagnetic-resonance spectra of Mn3+ in red beryl from Wah Wah Mountains (Utah USA) and of pink- and purple vesuvianite from Jeffrey Mine (Asbestos, Canada) were measured at room- and low temperatures. The crystal field stabilization energies are equal to 130.9 kJ/mol for the red beryl, and 151.5–158.0 and 168.0 kJ/mol for for the pink- and the purple vesuvianite, respectively. The red photoluminescence of Mn3+ was not intensive either at room- or at low temperatures. The high Mn content in the crystals caused the emergence of an additional emission band and short photoluminescence-decay lifetimes. The latter are only 183 μs for beryl and 17 μs for vesuvianite.Narodowe Centrum Nauk
Luminescence and other spectroscopic properties of purple and green Cr-clinochlore
For the first time ever, the luminescence spectra of Cr3+ centers in two chlorite crystals are presented. Chromium ions occupy the strong crystal-field site M4 in the brucite sheet and the intermediate crystal-field site in the inner octahedral sheet for purple and green chlorite, respectively. We discuss the influence of an effective positive charge on the Cr3+ ion and an effective negative charge of ligands on the differences in the values of the Dq and B parameters. It is concluded that the presence of Fe2+ ions and other point defects, as well as concentration quenching, causes the very short luminescence lifetimes of chromium ions
Prognostic significance, diagnosis and treatment in patients with gastric cancer and positive peritoneal washings. A review of the literature
Peritoneal dissemination is a common consequence of a relapse following a radical surgical treatment of gastric cancer. The development of the disease in the peritoneum depends not only on its stage, but also on free cancer cells exfoliated from the tumor mass or from involved lymph nodes, and which are capable of being implanted in the peritoneum. According to the latest TNM (7 edition; 2010) classification, patients with free cancer cells in the peritoneal washings qualify for stage IV of the disease. Patients in whom free cancer cells were found during the operation – have a recurrence of gastric cancer – mainly in the peritoneum, and the majority of them die within two years of the diagnosis. To properly assess the prognosis, it is vital to determine the stage of cancer by additionally assessing the washings for the presence of free cancer cells before taking a therapeutic decision. This also allows identifying those patients who require different medical procedures to obtain the best treatment results possible. Medical literature describes various methods of examining peritoneal washings aimed at detecting free cancer cells. The methods apply different cancer cell detection rates, sensitivity and specificity in prediction of a peritoneal relapse. Oncological Departments performing the evaluation of the washings employ non-standard methods of treatment in this group of patients and the results presented are promising
Luminescence properties of tetrahedral coordinated Mn2+ : genthelvite and willemite examples
The cause of the split of4A4E(4G) Mn2+ excited level measured on minerals spectra is discussed. It is our view that ∆E = |4E(4G) - 4A(4G)| should be considered an important spectroscopic parameter. Among the possible reasons for the energy levels splitting taken under consideration, such as the covalent bond theory, the geometric deformation of the coordination polyhedron and the lattice site’s symmetry, the first one was found to be inappropriate. Two studied willemite samples showed that the impurities occur in one of the two available lattice sites differently in both crystals. Moreover, it was revealed that the calculated crystal field Dq parameter can indicate which of the two non-equivalent lattice sites positions in the willemite crystal structure was occupied by Mn2+ . The above conclusions were confirmed by X-ray structure measurements. Significant differences were also noted in the Raman spectra of these willemites
Some complementary data about the spectroscopic properties of manganese ions in spodumene crystals
The color change of the pink and colorless LiAlSi2O6 spodumene crystal due to irradiation
and heating is explained. The hypothesis about the change of Mn3+ to Mn4+ after irradiation was
rejected. For the studied crystals, it was shown that both Mn2+ and Mn3+ occupy the M2 (not the M1)
crystal site. Spodumene crystals which are primary pink (kunzite) contain Mn3+ (and Mn2+) at the
M1 site. By contrast, those that become pink due to irradiation and heating contain Mn3+ and Mn2+
at the M2 site. The emission band of the former is 625 nm, and for the latter, it is 591 nm
Broadband near-infrared luminescence in lead germanate glass triply doped with Yb3+/Er3+/Tm3+
This paper deals with broadband near-infrared luminescence properties of lead germanate
glass triply doped with Yb3+/Er3+/Tm3+. Samples were excited at 800 nm and 975 nm. Their
emission intensities and lifetimes depend significantly on Er3+ and Tm3+ concentrations. For samples
excited at 800 nm, broadband emissions corresponding to the overlapped 3H4 ! 3F4 (Tm3+) and
4I13/2 ! 4I15/2 (Er3+) transitions centered at 1.45 m and 1.5 m was identified. Measurements of
decay curves confirm reduction of 3H4 (Tm3+), 2F5/2 (Yb3+) and 4I13/2 (Er3+) luminescence lifetimes
and the presence of energy-transfer processes. The maximal spectral bandwidth equal to 269 nm for
the 3F4 ! 3H6 transition of Tm3+ suggests that our glass co-doped with Yb3+/Er3+/Tm3+ is a good
candidate for broadband near-infrared emission. The energy transfer from 4I13/2 (Er3+) to 3F4 (Tm3+)
and cross-relaxation processes are responsible for the enhancement of broadband luminescence near
1.8 m attributed to the 3F4 !3H6 transition of thulium ions in lead germanate glass under excitation
of Yb3+ ions at 975 nm
Laser refrigeration by an Ytterbium-doped NaYF4 microspinner
Thermal control of liquids with high (micrometric) spatial resolution is required for advanced research such as single molecule/cell studies (where temperature is a key factor) or for the development of advanced microfluidic devices (based on the creation of thermal gradients at the microscale). Local and remote heating of liquids is easily achieved by focusing a laser beam with wavelength adjusted to absorption bands of the liquid medium or of the embedded colloidal absorbers. The opposite effect, that is highly localized cooling, is much more difficult to achieve. It requires the use of a refrigerating micro-/nanoparticle which should overcome the intrinsic liquid heating. Remote monitoring of such localized cooling, typically of a few degrees, is even more challenging. In this work, a solution to both problems is provided. Remote cooling in D2O is achieved via anti-Stokes emission by using an optically driven ytterbium-doped NaYF4 microparticle. Simultaneously, the magnitude of cooling is determined by mechanical thermometry based on the analysis of the spinning dynamics of the same NaYF4 microparticle. The angular deceleration of the NaYF4 particle, caused by the cooling-induced increase of medium viscosity, reveals liquid refrigeration by over −6 K below ambient conditionsThis work was supported by the Ministerio de Ciencia e Innovación
de España (PID2019-106211RB-I00 and PID2019-105195RA-I00) and
by Universidad Autónoma de Madrid and Comunidad Autónoma de
Madrid (SI1/PJI/2019-00052). E.O.R gratefully acknowledges the financial
support provided by the Spanish Ministerio de Universidades, through
the FPU program (FPU19/04803). K.P. acknowledges financial support
from NCN, Poland, grant number 2018/31/D/ST5/0132
Spectroscopic and structural investigations of blue afwillite from Ma’ale Adummim locality, Palestinian Autonomy
Until now, only the colourless crystals of mineral afwillite, Ca3(HSiO4)2$2H2O, were known from several
localities around the world. Present work focuses on blue afwillite counterparts from the Ma’ale
Adummim locality in Palestine. Using the wide spectrum of analytical methods we attempted to identify
the causes of this unusual colour. Structural investigation confirms the presence of two tetrahedral
SiO3OH units connected by hydrogen bonds. The Raman spectrum of afwillite, obtained for the first time,
shows the increased number of bands in the range of 785-970 cm-1, whose assignation was correlated
with the presence of two different kinds of structural units: (SiO3OH)3- and its deprotonated counterpart
(SiO4)4-. The heating process at 250 C, in addition to the colour changes from blue to pastel green, shows
the intensity reduction and disappearing of some Raman bands attributed mainly to SiO3OH units. The IR
investigation confirms also the presence of that unit and provides information that the position and
designation of infrared bands above ~2300 cm-1 is related to the strength of hydrogen bonds within the
structure. The stretching and bending OH vibrations of afwillite sample show the partial shift to the
lower spectral frequencies after the H/D isotopic exchange in OH or H2O groups. Based on the results of
the electron absorption and luminescence analyses it has been proposed that the blue colour of afwillite
is caused by hole oxygen defect, most probably SiO3 -