642 research outputs found
Crystal structure of the high-pressure phase of the oxonitridosilicate chloride Ce4[Si4O3 + xN7 − x]Cl1 − xOx, x≃0.2
The structural compression mechanism of Ce4[Si4O3 + xN7 − x]Cl1 − xOx, x≃ 0.2, was investigated by in situ single-crystal synchrotron X-ray diffraction at pressures of 3.0, 8.5 and 8.6 GPa using the diamond–anvil cell technique. On increasing pressure the low-pressure cubic structure first undergoes only minor structural changes. Between 8.5 and 8.6 GPa a first-order phase transition occurs, accompanied by a change of the single-crystal colour from light orange to dark red. The main structural mechanisms, leading to a volume reduction of about 5% at the phase transition, are an increase in and a rearrangement of the Ce coordination, the loss of the Ce2, Ce3 split position, and a bending of some of the inter-polyhedral Si—N—Si angles in the arrangement of the corner-sharing Si tetrahedra. The latter is responsible for the short c axis of the orthorhombic high-pressure structure compared with the cell parameter of the cubic low-pressure structure
High-Pressure Phase Transition of the Oxonitridosilicate Chloride Ce4[Si4O3+xN7-x]Cl1-xOx with x = 0.12 and 0.18
The high-pressure behaviour of the oxonitridosilicate chlorides Ce4[Si4O3þxN7-x]Cl1-xOx, x = 0.12 and 0.18, is investigated by in situ powder synchrotron X-ray diffraction. Pressures up to 28 GPa are generated using the diamond-anvil cell technique. A reversible phase transition of first order occurs at pressures between 8 and 10 GPa. Within this pressure range the high- and the low-pressure phases are observed concomitantly. At the phase transition the unit cell volume is reduced by about 5%, and the cubic symmetry (space group P213) is reduced to orthorhombic (space group P212121) following a translationengleiche group-subgroup relationship of index 3. A fit of a third-order Birch-Murnaghan equation of state to the p-V data results in a bulk modulus B0 = 124(5) GPa with its pressure derivative B0 = 5(1) at V0 = 1134.3(4) Å3 for the low-pressure phase and in B0 = 153(10) GPa with B0 = 3.0(6) at V0 = 1071(3) Å3 for the high-pressure phase. The orthorhombic phase shows an anisotropic axial compression with the a axis (which is the shortest axis) being more compressible (k(a) = 0.0143(4) 1/GPa) than the b and c axes (k(b) = 0.0045(2), k(c) = 0.0058(2) 1/GPa). The experimental results confirm an earlier prediction of the pressureinduced instability of isotypic Ce4[Si4O4N6]O, and also show that the bulk modulus was predicted reasonably well
An Elementary Rigorous Introduction to Exact Sampling
We introduce coupling from the past, a recently developed method for exact sampling from a given distribution. Focus is on rigour and thorough proofs. We stay on an elementary level which requires little or no prior knowledge from probability theory. This should fill an obvious gap between innumerable intuitive and incomplete reviews, and few precise derivations on an abstract level
Compressibility of the nitridosilicate SrYb[Si4N7] and the oxonitridoaluminosilicates MYb[Si4−xAlxOxN7−x] (x = 2; M = Sr, Ba)
The compressibilities of the nitridosilicate SrYb[Si4N7] and the oxonitridoaluminosilicates MYb[Si4−xAlxOxN7−x] (x = 2; M = Sr, Ba) were investigated by in situ high-pressure X-ray powder diffraction. Pressures up to 42 GPa were generated using the diamond–anvil cell technique. The title compounds are structurally stable to the highest pressure obtained. A fit of a third-order Birch–Murnaghan equation-of-state to the p–V data results in V0 = 302.91 (6) Å3, B0 = 176 (2) GPa and B′ = 4.4 (2) for SrYb[Si4N7]; V0 = 310.4 (1) Å3, B0 = 161 (2) GPa and B′ = 4.6 (2) for SrYb[Si4−xAlxOxN7−x]; and V0 = 317.3 (5) Å3, B0 = 168 (2) GPa and B′ = 4.7 (2) for BaYb[Si4−xAlxOxN7−x]. While the linear compressibilities of the a and c axes of BaYb[Si4−xAlxOxN7−x] are very similar up to 30 GPa, distinct differences were observed for SrYb[Si4N7] and SrYb[Si4−xAlxOxN7−x], with the c axis being the most compressible axis. In all of the investigated compounds the bulk compressibility is dominated by the compression behaviour of the tetrahedral network, while the size of the substituted cation plays a minor role
The level of interleukin-1after intravesical klh instillation in patients with superficial transitional cell cancer of the urinary bladder
Ova studija potvrđuje mišljenje da instilacija KLH-a stimulira produkciju citokina, koji se zatim izlučuju putem mokraće. Interleukin 1(IL-1) koji proizvode aktivirani makrofagi, domino-efektom stimulira niz imunih reakcija. lnstilacijski program započinje 5 do 7 dana nakon TUR-a primarnoga površnog karcinoma mjehura. Taj program obuhvaća intravezikalnu instilaciju 20 mg KLH-a, razvodnjenoga u 20 ml fiziološke otopine, jedanput tjedno, ukupno 6 puta, a zatim jedanput mjesečno tijekom godine dana. Nakon instilacije KLH-a u mjehur, IL-alfa izlučuje se u mokraći. U svrhu analize korišten je specifični enzimski imunosorbent esej (ELISA). ELISA za IL-1 a, utemeljen u našem laboratoriju, pokazuje graničnu vrijednost otkrivanja od 5 pg/ml. Taj IL-la ELISA varira od 3 do 7% unutar naših mogućnosti mjerenja, a 5 do 15% od serije do serije. U terapijskoj skupini sekrecija IL-la varira u rasponu od 0 do 30.905 pg/24h, dok u kontrolnoj skupim taj se raspon kreće između 0 (razdoblje sakupljanja) i 2.472 pg/4h. Sekrecija IL-la nakon instilacije KLH-a u mjehur bolesnika s karcinomom, značajno raste, uz napomenu da visina te sekrecije znatno varira od bolesnika do bolesnika. Maksimum je izlučivanja postignut tijekom 4 do 8 sati nakon mstilacije, nakon čega to izlučivanje postupno opada. Pritom se pokazala neuobičajeno izražena razlika u količini izlučenoga IL-la tijekom 24 sata u kontrolnoj skupini, od skupine kojoj je instiliran KLH. Osam od 14 bolesnika (57%) koliko ih je reagiralo na KLH, imali su nakon šestotjedne terapije veću koncentraciju IL-la u mokraći nego oni bolesnici koji tijekom 12 mjeseci nisu reagirali na KLH, uz napomenu da razlike nisu bile statistički značajne. Smatra se da sekrecija IL-1 alfa u mokraći predstavlja biološki odgovor mjehura na antigenski stimulus KLH-a. U primjercima mokraće nije nađen IL-2. Preostaje da se dodatnim ispitivanjima utvrdi prisustvo IL-2 citokina, uz napomenu da je možda količina citokina bila ispod granice detekcije koju zahtijeva ELISA. Potrebno je utvrditi stimulira li intravezikalno instiliran Keyhole limpet haemocyanin (KLH) lokalni odgovor stanica sluznice mokraćnoga mjehura u bolesnika s površnim karcinomom mjehura.Our study confirms the theory that instillation of KLH stimulates production of cytokines, resulting in their secretion in urine. Interleukin- 1 (IL-1) stimulates the immune cascade through a domino effect and is produced mainly by activated macrophages. The instillation program was started 5-7 days after TUR of primary superficial cell carcinoma. Twenty mg KLH in 20 ml of 0.9%
NaCl was instilled into the bladder each week for 6 consecutive weeks and then monthly for one year. When KLH is instilled into the bladder, IL-1alpha is secreted in the urine. A specific enzyme-linked immunosorbent assay (ELISA) was used for analysis. The ELISA for IL-1a was established in our laboratory and showed a detection limit of 5 pg/ml. This IL-1a ELISA deviation amounts to 3-7% within a series of measurements, and 5-15% from series to series. In the therapy group the IL-1a secretion ranged from 0 to 30,905 pg/24 h and in the control group from 0 (collection period) to 2,472 pg/4 h. IL 1a production increased significantly after KLH instillation in bladder cancer patients; however, the level varied considerably from patient to patient. Maximum production was achieved within a period of 4-8 h, decreasing within 24 h. There was a striking difference between the amount of IL-1a produced over the 24-hour period in the control group and that of the KLH group. 8 of 14 patients (57%) who responded to KLH therapy, had higher urine IL-1a levels after 6 weeks of KLH treatment than those who failed to respond within 12 months, but the levels were not of statistical significance. The secretion of IL-1a in urine is the biological response of the bladder to the antigen stimulus of KLH. No IL-2 was detected in the urine samples. It remains to be determined whether no IL-2 cytokine was present, or whether the amount was smaller than the minimal detection limit required for the ELISA
Antibody response to intravesical klh instillation in patients with superfical transitional cell cancer of the urinary bladder
Analizirana je bila dinamika specifične produkcije KLH-antitijela nakon intrakutane i intravezikalne instilacije KLH-a. U razmatranju je bilo 9 bolesnika, i to 7 muškaraca i 2 žene, u dobi od 45 do 75 (prosječna vrijednost 68.6 god.), svi s primamim površnim karcinomom mjehura. Ti su bolesnici nakon kompletne resekcije tumora bili imunizirani intrakutanom injekcijom 1 mg Keyhole limpet haemocyanin (KLH). Postupak je nastavljen intravezikalnom aplikacijom 20 mg KLH-a u 20 ml fiziološke otopine jedanput tjedno, tijekom sljedećih 6 tjedana, a zatim tijekom godine dana, jedanput mjesečno i konačno, svaka 2 mjeseca tijekom sljedeće 2 godine. Antitijela prema KLH-u bila su u serumu ovih bolesnika određivana pomoću posebno razvijenoga i direktno povezanoga imunosorbentnoga eseja (ELISA: prema H. von Kammer. Max Planck Institute for Biophysical Chemistry, Göttingen, Njemačka). Primjerak krvi uzet je za ispitivanje titra antitijela prije postupka i 8 tjedana nakon postupka. Titar KLH-antitijela u bolesnika s karcinomom mjehura signifikantno je porastao nakon terapije KLH-om (Mann Whitney test P=0.02), uz napomenu da je ta razina u većem rasponu varirala od bolesnika do bolesnika. Od tih je 9 bolesnika 6 (67%) pokazivalo povišeni serumski titar antitijela prema KLH-u, dok su 4 bolesnika (44.4%) bila bez tumora tijekom promatranja koje je trajalo od 10 do 45 mjeseci (srednja vrijednost 30.7 mjeseci). Jedan bolesnik koji nije imao povišeni titar antitijela prema KLH-u bio je također bez recidiva, dok su daljnja 2 bolesnika doživjela recidiv tumora, i to nakon aplikacije KLH-a. Dva su bolesnika pokazala recidiv tumora, unatoč povišenom titm antitijela. Ni u jednoga bolesnika s recidivom nakon primjene KLH-a, nije bilo progresije tumora. Četvorica od 5 bolesnika (80%) bez recidiva pokazivali su pozitivni kožni test. Od bolesnika pak s recidivom tumora 50% ih je imalo negativni kožni test. Recidiv tumora imalo je 44.4% bolesnika tretiranih s KLH-om. Stupanj recidiva iznosio je 1.6, dok je vrijeme pojave recidiva bilo 8.75 mjeseci. Instilacija KLH-a nije uzrokovala značajnije negativne posljedice. Pozitivni kožni test i odgovor antitijela na KLH više su registrirani u bolesnika s pozitivnim odgovorom, tj. u onih koji nakon terapije nisu više imali tumor nego u onih bolesnika koji su bili bez odgovora. Produkcija antitijela na KLH čini se daje biološki odgovor na antigenski stimulus KLH-a.The dynamics of the specific KLH-antibody production after intracutaneous and intravesical instillation was analysed. Nine patients (male n=7; female n=2 mean 68.6 years, range 47-75) with primary superficial carcinomas of the bladder, were intracutaneously immunized with 1 mg Keyhole Limpet Haemocyanin (KLH) after the complete resection of tumors. Treatment consisting of 20 mg KLH in 20 ml saline introduced intravesically was continued once a week during the next 6 weeks, then once a month during one year and finally once every two months during the next 2 years. Antibodies against KLH in patients\u27 sera were determined by means of specially developed direct enzyme-linked immunosorbent assay (ELISA: according to H. von der Kammer, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany). Blood was taken for antibody-titer examination before the treatment and 8 weeks after the treatment. The KLH-antibody titer increased significantly after KLH therapy (Mann-Whitney-Test P=0.02) in bladder cancer patients, however the level varied considerably from patient to patient. Six out of 9 patients (67%) presented increased serum antibody titers to KLH after immunotherapy, 4 patients (44.4%) remained free of tumor during the established follow-up period of 10-45 months (median 30.7 months). One patient without increased antibody titer to KLH was free of tumor. Two patients however, suffered from tumor recurrence after the KLH course. Two patients presented tumor recurrence in spite of increased antibody titers. No evidence of tumor progression occurred in patients with recurrence after KLH therapy. Four out of 5 patients (80%) without tumor recurrence presented positive skin test. In patients with tumor recurrence, 50% of them had a negative skin test. 44.4% KLH-treated patients had tumor recurrence. The recurrence rate was 1.6. Time span of recurrence was 8.75 months. KLH instillation did not induce major side effects. Positive skin test reactivity and KLH antibody response were more commonly seen in responding patients (i.e. those who remained tumor-free after the therapy) than in non-responders. The production of KLH antibodies apparently is the biological response to the antigen stimulus of KLH
Finite rank perturbations of linear relations and matrix pencils
We elaborate on the deviation of the Jordan structures of two linear relations that are finite-dimensional perturbations of each other. We compare their number of Jordan chains of length at least n. In the operator case, it was recently proved that the difference of these numbers is independent of n and is at most the defect between the operators. One of the main results of this paper shows that in the case of linear relations this number has to be multiplied by n+ 1 and that this bound is sharp. The reason for this behavior is the existence of singular chains. We apply our results to one-dimensional perturbations of singular and regular matrix pencils. This is done by representing matrix pencils via linear relations. This technique allows for both proving known results for regular pencils as well as new results for singular ones.Fil: Leben, Leslie. Technische Universität Ilmenau; AlemaniaFil: Martinez Peria, Francisco Dardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Argentino de Matemática Alberto Calderón; Argentina. Universidad Nacional de la Plata. Facultad de Cs.exactas. Centro de Matematica de la Plata.; ArgentinaFil: Philipp, Friedrich. Technische Universität Ilmenau; AlemaniaFil: Trunk, Carsten. Technische Universität Ilmenau; Alemania. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Argentino de Matemática Alberto Calderón; ArgentinaFil: Winkler, Henrik. Technische Universität Ilmenau; Alemani
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