The prognostic significance of minimal residual disease in adult Egyptian patients with precursor acute lymphoblastic leukemia

AbstractBackgroundMinimal residual disease (MRD) studies in adult acute lymphoblastic leukemia (ALL) give highly significant prognostic information superior to other standard criteria as age, gender and total leucocytic count (TLC) in distinguishing patients at high and low risk of relapse.ObjectivesWe aimed to determine the value of MRD monitoring by flowcytometry (FCM) in predicting outcome in adult Precursor ALL patients.Patients and methodsBone marrow (BM) samples were analyzed by 4-color FCM collected at diagnosis and after induction therapy (MRD1) to correlate MRD positivity with disease free survival (DFS) and overall survival (OS).ResultsStudy included 57 adult ALL patients (44 males and 13 females) with a median age of 22years (18–49). DFS showed no significant difference with age, gender and initial TLC (p=0.838, 0.888 and 0.743, respectively). Cumulative DFS at 2years was 34% for B-lineage ALL (n: 35) and 57% for T-lineage ALL (n: 18) (p=0.057). Cumulative DFS at 2years was 7% for MRD1 positive (high risk, HR) versus 57% for MRD1 negative patients (Low risk, LR) (p<0.001). Cumulative DFS at 2years was 29% for HR patients (n: 26) versus 55% for LR (n: 27) according to GMALL classification (p=0.064). Cumulative OS did not differ according to age, gender and TLC (p=0.526, 0.594 and 0.513, respectively). Cumulative OS at 2years was 36% for B ALL (n: 39) versus 77% for TALL (n: 18) (p=0.016) and was 49% for Philadelphia chromosome (Ph) negative patients versus 0% for Ph-positive patients (p<0.001). Regarding MRD1, OS at 2years was 18% for MRD1 HR (n: 17) versus 65% for MRD1 LR (n: 38) (p<0.001). OS was 35% for high-risk patients (n: 30) and 62% for low-risk patients (n: 27) classified according to GMALL risk stratification (p=0.017).ConclusionMRD by FCM is a strong independent predictor of outcome in terms of DFS and OS and is a powerful informative parameter in guiding individual treatment in ALL patients

Role of hydrodynamic factors in controlling the formation and location of unconformity-related uranium deposits: insights from reactive-flow modeling

The role of hydrodynamic factors in controlling the formation and location of unconformity-related uranium (URU) deposits in sedimentary basins during tectonically quiet periods is investigated. A number of reactive-flow modeling experiments at the deposit scale were carried out by assigning different dip angles and directions to a fault and various permeabilities to hydrostratigraphic units). The results show that the fault dip angle and direction, and permeability of the hydrostratigraphic units govern the convection pattern, temperature distribution, and uranium mineralization. Avertical fault results in uranium mineralization at the bottom of the fault within the basement, while a dipping fault leads to precipitation of uraninite below the unconformity either away from or along the plane of the fault, depending on the fault permeability. A more permeable fault causes uraninite precipitates along the fault plane,whereas a less permeable one gives rise to the precipitation of uraninite away from it. No economic ore mineralization can form when either very low or very high permeabilities are assigned to the sandstone or basement suggesting that these units seem to have an optimal window of permeability for the formation of uranium deposits. Physicochemical parameters also exert an additional control in both the location and grade of URU deposits. These results indicate that the difference in size and grade of different URU deposits may result from variation in fluid flow pattern and physicochemical conditions, caused by the change in structural features and hydraulic properties of the stratigraphic units involved

Absolute evaluation of ferrous and ferric concentration in Ca amphibole

Studies are made of M?sshauer absorption of 57Fe in a Ca-amphibole schist sample at room and liquid nitrogen temperatures. The absolute concentration and the recoilless fraction for ferrous and ferric cations are determined using a method, basically concerned to adapt the M?ssbauer effect areas at two different temperatures with the actual concentration of Mossbauer nuclei in the absorbers. The method gets its effectiveness, when the recoilless fractions of iron in different sites are not the same. Methods of calculations and required standard curves are reported.Wiley Online Librar

دراسة حديديات الزنك والكوبالت باستخدام ظاهرتى الحيود ا لنيوتروني وتأثير موسباور

The mixed cubic ferrite Zno.g5 €00.15 Fez 04 is studied by neutron diffraction and Mossbauer effect techniques at the temperature range 4.2 - 293 °K. The obtained spectra by both methods at low temperature show a long range magnetic ordering. The neutron pattern at 4.2 °K is successfully indexed on the basis of a magnetic unit cell obtained by doubling the chemical unit cell in one direction. A non collinear model is proposed for the magnetic structure of this compound. The Mossbauer effect data favour the proposed model and indicate that the magnetic moments are aligned at an angle of about 55° relative to the [112] direction in the magnetic unit cell.لقد تم دراسة حديديات الزنك والكوبالت باستخدام ظاهرتي الحيود النيوتروني وتأثير موسباور في المدى الحراري 4.2 – 293 ‏درجة مطلقة . وأظهرت الأطياف التي تم الحصول عليها عند درجات الحرارة المنخفضة التحول المغناطيسي للعينات تحت الدراسة وقد تبين من دراسة نموذج الحيود النيوتروني عند درجة حرارة الهليوم السائل 4.2 ‏درجة مطلقة ان الخلية المغناطيسية تعادل ضعف الخلية الكيمائية وقد أمكن الحصول على موديل يصف ترتيب الحركة المغزلية داخل وحدة الخلية المغناطيسية للمركب تحت الدراسة .أمكن الحصول على موديل يصف ترتيب الحركة المغزلية داخل وحدة الخلية المغناطيسية للمركب تحت الدراسة

On the Valence State of Iron in Sr0.52+Ca0.52+Fe0.54+ Me0.54+O32−

Powder samples of Sr0.5Ca0.5Fe0.5Me0.5O3 (Me = Co, Zr or Mn) and Sr0.3La0.7FeO3 are investigated by X-ray diffraction and Mossbauer effect spectroscopy. Analysis of the completely ordered spectra suggested three kinds of iron ions coexist in general where the resolution into the different valence state is clearly seen. The Mossbauer effect parameters values are found to be close to those expected for Fe3+, Fe4+ and Fe5+ indicating that some of the tetravalent iron ions in its high spin state disproportionate into Fe3+ and Fe5+ ions passing through temperature dependent intermediate valence states.Wiley Online Librar

دراسة موسباور في المجتيتايت المطعم بالكوبالت

The Mossbauer effect has been studied in the mixed ferrites CoxFe3_x04 (for x = 0.8, 0.9 and 1) with the spinel structure in the temperature range between 78 and 830K. The composition with x = 1, showed an expected Zeeman spectrum with two overlapping magnetic hyperfine patterns related to the Fe34' ions in tetrahedral and octahedral sites. While for samples with x = 0.8 and 0.9 the Mossbauer spectrum for each compound was successfully analysed into three different patterns corresponding to the ferric ions placed at the tetrahedral and octahedral sites and ferrous ions at the octahedral sites, indicating no electron transfer between Fe^ and Fe24", where the quantity of cobalt sufficiently large to be located at the six nearest neighbours to ferrous ions. The Mossbauer effect parameters were calculated for these observed sites and their variation with temperature reported. The reduced hyperfine magnetic fields of the Fe^ (B) ions were found to follow the one third power law. The magnetic ordering temperature was determined to be == 815 K and the possible magnetic interactions were discussed.لقد تم دراسة تأثير موسباور في مجموعة الحديديات كو س ح3-س أ4 (حيث س = 0.8، 0.9، 1) ذات التركيب البللورى للاسبنيل في درجات الحرارة (78-830) درجة مطلقة . وقد ظهر طيف زيمان للعينة ذات قيمة س = 1 وله مجموعتان منطبقتان للتركيب المغناطيسي فوق الدقيق تنتمي إلى الحديد الثلاثي في مواقع رباعية وثمانية الأسطح . وقد تم بنجاح تحليل طيف موسمبار للعينات ذات قيم س =0.8 ، 0.9 إلى ثلاث مركبات اثنين منها تنتمي للحديد الثلاثي أما الثالث فينتمي للحديد الثنائي في موقع ثماني الأسطح. وقد تم تعيين درجة حرارة التحول المغناطيسي لهذه العينات وحساب كل بارامترات موسباور لها ومناقشة قيمتها في ظل التفاعلات المغناطيسية الممكنة

البارامترات البللورية والدقيقة للحديديات السداسية

The alkaline earth monoferrites BaCaxSr1-xFe4O8 with X = 0,0.5and 1, were studied by Mossbauer spectroscopy and neutron diffractometry over a wide range of temperatures (78 - 900 K). The lattice constants were obtained from X-ray powder patterns. The nuclear intensities of coherent Bragg reflections above the magnetic transition temperatures were successfully interpreted according to the space group P31m with one formula unit per unit cell. Neutron magnetic intensities and magnetically split Mossbauer spectra showed that all compositions to be antiferro-magnetic due to interactions between nearest neighbour Fe3" ions with magnetic unit cell has the same periodicity as the crystallographic one. The reduced hyperfine magnetic fields of the Fet ions were found to follow the Briliouin curve for S = 5/2. Crystallographic and Mossbauer parameters were reported and relationships between structural and magnetic properties were discussedتم دراسة المركبات الحديدية ذات التركيب الكيمائي باكا ست ح أ س 1- س 84 بواسطة ظاهرتي الموسباور وحيود النيوترونات في المدى الحراري (78 - 900 درجة مطلقة) . وقد أمكن حساب ثوابت الخلية لهذه المركبات من نماذج حيود الأشعة السينية لها . كذلك أظهرت الشدة النووية لانعكاسات براج البناءة أن هذه الحديديات تنتمي إلى التركيب البللوري ذي التنظيم P3 Lm وتحتوى على جزء لكل وحدة خلية . وأوضحت قياسات البعثرة المغناطيسية للنيوترونات والانقلاقات المغناطيسية لنماذج موسباور أن هذه المركبات ذات ترتيب انتيفيرو مغناطيسي داخل خلية مغناطيسية مساوية للخلية البلورية وذلك نتيجة التفاعلات المغناطيسية لأيونات الحديد الثلاثية مع جيرانها والتي تبعت قيم مجالاتها المغناطيسية الدقيقة منحنى بريلون . هذ ا وقد نوقشت الخواص البللورية والمغناطيسية لهذه الحديديات السداسية في ظل النتائج العملية التي تم الحصول عليها

دراسة الحيود النيوترني وظاهرة موسباور لمركب الجارنت المطعم بالعناصر الأرضية النادرة

A powder sample of Y^YbFesO,; was prepared using the ceramic technique. X-ray diffraction pattern showed a single phase of the garnet type structure with a lattice constant 12.323 A". Specific heat for this composition was found to change anomously at a transition point 555±5K. Neutron diffraction and Mossbauer effect measurements were obtained over a wide range of temperature (600-4.2K) and supported the existence of a collinear ferrimagnetic spin model below the point down to 4.2K. Curie. Crystallographic, magnetic and hyperfine parameters were determined and discussed.تم تحضير عينة نقية من مسحوق مركب جارنت الأيتريوم المطعم بالايتربيوم Y2YbFe5O12 واختبارها بالأشعة السينية وحساب ثابت الخلية لها .(12.323 انجستروم) ومن قياس الحرارة النوعية لهذا المركب تبين أنها تتغير عند درجة انتقال 555 درجة مطلقة . وقد أظهر نموذج الأشعة تحت الحمراء لهذا المركب ثلاثة خطوط امتصاص في مدى تردد قيمته 1000 سم-1 واستخدمت لتعيين درجة حرارة ديباى الخاصة به . وتم كذلك قياس نماذج الحيود النيوتروني وأطياف موسباور في مدى حرارى واسمع . أمكن من تحليلها تأكيد وجود تركيب فيريمغناطيسى تكون فيه العزوم المغناطيسية المغزلية متوازية وقد نوقشت النتائج في ظل البارمترات البللورية والمغناطيسية والفرق دقيقة التي تم الحصول عليها