Large microwave generation from d.c. driven magnetic vortex oscillators in magnetic tunnel junctions

Spin polarized current can excite the magnetization of a ferromagnet through the transfer of spin angular momentum to the local spin system. This pure spin-related transport phenomena leads to alluring possibilities for the achievement of a nanometer scale, CMOS compatible and tunable microwave generator operating at low bias for future wireless communications. Microwave emission generated by the persitent motion of magnetic vortices induced by spin transfer effect seems to be a unique manner to reach appropriate spectral linewidth. However, in metallic systems, where such vortex oscillations have been observed, the resulting microwave power is much too small. Here we present experimental evidences of spin-transfer induced core vortex precessions in MgO-based magnetic tunnel junctions with similar good spectral quality but an emitted power at least one order of magnitude stronger. More importantly, unlike to others spin transfer excitations, the thorough comparison between experimental results and models provide a clear textbook illustration of the mechanisms of vortex precessions induced by spin transfer

Modeling the power consumption of Ethernet switch

International audienceAt present, one of the main concerns of green network is to minimize the power consumption of network infrastructure. Surveys show that, the highest amount of power is consumed by the network devices during its runtime. However to control this power consumption it is important to know which factors has highest impact on this matter. This paper is focused on the measurement and modeling of the power consumption of an Ethernet switch during its runtime, considering various types of input parameters with all possible combinations. For the experiment, three input parameters are chosen. They are bandwidth, traffic and number of connections. The output to be measured is the power consumption of the Ethernet switch. Due to the uncertain power consuming pattern of the Ethernet switch a fully-comprehensive experimental evaluation would require an unfeasible and cumbersome experimental phase. Because of that, a design of experiment (DoE) method has been applied to obtain adequate information on the effects of each of the input parameters on the power consumption. The whole work consists of three parts. In the first part a test bed is planned with input parameters and the power consumption of the switch is measured. The second part is about generating a mathematical model with the help of design of experiment tools. This model can be used for measuring precise power consumption in different scenarios and also pinpoint the parameters with higher influence in power consumption. And in the last part, the mathematical model is evaluated by comparison with the experimental values

Bilateral undisplaced insufficiency neck of femur fractures associated with short-term steroid use: a case report

<p>Abstract</p> <p>Introduction</p> <p>We present an interesting and unusual case of a 61-year-old woman with bilateral, undisplaced, stress neck of femur fractures associated with short-term steroid use. Insufficiency fractures of the neck of femur without preceding trauma have been described in the literature, although bilateral involvement is infrequent. These fractures have been associated with strenuous exercise, seizures, renal osteodystrophy, fluoride treatment, long-term corticosteroid use, amenorrhoea, abnormal anatomy and osteomalacia due to nutritional and/or hormonal factors.</p> <p>Case Presentation</p> <p>The case we present differs from other published reports, in that the patient's symptoms developed acutely after only a short course of steroids and with no associated trauma or strenuous exercise. It is also the only case described where no operative intervention was required.</p> <p>Conclusion</p> <p>Our case reiterates the importance of considering insufficiency or stress fractures in high-risk patients who present with musculoskeletal pain. Institution of bone protection should also be considered in these patients. Morbidity related to delayed treatment has been well documented, so a high level of clinical suspicion is imperative.</p

Mineral maturity and crystallinity index are distinct characteristics of bone mineral

The purpose of this study was to test the hypothesis that mineral maturity and crystallinity index are two different characteristics of bone mineral. To this end, Fourier transform infrared microspectroscopy (FTIRM) was used. To test our hypothesis, synthetic apatites and human bone samples were used for the validation of the two parameters using FTIRM. Iliac crest samples from seven human controls and two with skeletal fluorosis were analyzed at the bone structural unit (BSU) level by FTIRM on sections 2–4 lm thick. Mineral maturity and crystallinity index were highly correlated in synthetic apatites but poorly correlated in normal human bone. In skeletal fluorosis, crystallinity index was increased and maturity decreased, supporting the fact of separate measurement of these two parameters. Moreover, results obtained in fluorosis suggested that mineral characteristics can be modified independently of bone remodeling. In conclusion, mineral maturity and crystallinity index are two different parameters measured separately by FTIRM and offering new perspectives to assess bone mineral traits in osteoporosis

2002; 01

DLI is feasible with rapid engraftment and minimizes the risk of severe GVHD. Large prospective trials are required to prove that it preserves the GVL effect fully. ©2002, Ferrata Storti Foundation Key words: allogeneic transplantation, GVHD, GVL, CD34 selection, donor lymphocyte infusions. plication of DLI is GVHD, which is often associated with response to DLI. © F e r r a t a S t o r t i F o u n d a t i o n Design and Methods Patients and donors Twenty-four patients with hematologic malignancies, 18 males and 6 females, aged 14 to 56 years (median 46 years) were included. Their clinical characteristics are summarized in © F e r r a t a S t o r t i F o u n d a t i o n obtained from patients and donors and our institution&apos;s Ethical Committee approved the protocol. Clinical management The conditioning regimen depended on the clinical diagnosis. The following regimens were used: 1) Ara-C (12 g/m 2 ), cyclophosphamide (120 mg/m 2 ) and single dose total body irradiation-TBI (8 Gy) (AML and MDS patients); 2) Ara-C (18 g/m 2 ), melphalan (140 mg/m 2 ) and fractionated TBI (12 Gy) (ALL patients); 3) busulfan (16 mg/kg) and cyclophosphamide (120 mg/kg) (CML and 2 nd transplant patients); 4) cyclophosphamide (120 mg/kg) and fractionated TBI (12 Gy) (NHL and CLL patients). All patients were treated with 5 µg/kg/d lenograstim (Granocyte®) from day +1 until the granulocyte count was &gt; 10 9 /L for three consecutive days or &gt; 10 10 /L for one day. Six early patients (4 not HLA-identical to their donor and 2 AML in CR1) received a short course of methotrexate in addition to cyclosporine (CyA). Because of the low incidence of acute GVHD observed in the first 9 patients, GVHD prophylaxis was carried out with CyA alone for patients 10 to 24. The diagnosis and grading of acute and chronic GVHD was established as previously reported. Stem cell mobilization, collection and selection Donors received human granulocyte colonystimulating factor (G-CSF) (Granocyte®, kindly provided by Rhône-Poulenc-Rorer, Brussels, Belgium) at a dose of 10-15 µg/kg from day -5 through day -1 before transplant. Collection of PBSC was carried out on days -1 and 0, using a continuous flow blood cell separator (CS3000+, Baxter-Fenwall Laboratories, Deerfield, IL, or Cobe Spectra, Lakewood, CO, USA). The volume of blood processed was 12-16 liters. The PBSC from the first day of harvest were stored overnight in the patient&apos;s own plasma. Immediately after the second harvest, PBSC from the first and the second days of harvest were pooled. CD34 + cell selection was carried out using the Isolex 300i® magnetic cell separator (Nexell International, Wemmel, Belgium), according to the manufacturer&apos;s recommendations. Donor lymphocyte infusions Around day 60 post-transplantation, donors underwent 12-16 liter leukophereses on 2 consecutive days to collect lymphocytes. The collection from the first day of harvest was stored overnight in the patient&apos;s own plasma and pooled with the second harvest before processing by CD8 + selection using the Nexell Isolex 300i®. The CD8-negative fraction was recovered and divided into 3 aliquots containing 2×10 6 , 1×10 7 and 5×10 7 CD3 + cells/kg recipient for patients from #1 to #13. The 2 nd and 3 rd aliquots were cryopreserved in 10% DMSO in a controlled-rate freezer. After an interim analysis showed little acute or chronic GVHD associated with DLI, the schedule of DLI was changed to 2 aliquots of 1×10 7 and 5×10 7 CD3 + cells/kg recipient for patients 14 to 21. Aliquot 1 was injected fresh immediately after the CD8 depletion procedure (around day 60). Around day 100 (and 140 for patients 1 to 13), aliquot 2 (and 3) were thawed and infused into the patient. CD8-depleted DLI were not to be infused in case of an antecedent grade III or IV acute GVHD, or an antecedent extensive chronic GVHD, or active GVHD at the time of the scheduled infusion. Laboratory analyses Aliquots of the pooled PBSC as well as the CD34 + selected fraction were incubated with phycoerythrin-conjugated anti-CD34 monoclonal antibody (HPCA2; Becton-Dickinson, Palo-Alto, CA, USA) for 20 minutes at 20°C, washed and fixed. A total of 1×10 5 cells was analyzed using a FACS-scan analyzer (Becton-Dickinson). The percentage of CD34 + cells was defined with dot plot analysis using the whole nucleated cell population. The percentage of positive cells in the isotype control was subtracted from the CD34 + percentage to give the final percentage of CD34 + cells. Data acquisition was performed with the Cellquest software (BectonDickinson). Donor lymphocytes (before and after CD8 depletion) were similarly examined using double labeling with FITC-and PE-conjugated antibodies after treatment with a lysing solution. Complete blood counts were determined using a Technicon H2 cell counter (Bayer Diagnostics, Diegem, Belgium). Percentages of reticulocytes were obtained by an automated cytofluorometric method using the thiazole orange analog DEQTC. Statistical analyses Student&apos;s t-tests were used to compare cell subsets before and after CD8 depletion. The probability of GVHD, relapse, and survival as well as the speed of engraftment were studied by life-table analyses and Wilcoxon rank tests were used for comparisons between groups. Statistical analyses were carried out with Graphpad Prism (Graphpad Software, San Diego, CA, USA). Results Collection of PBSC, CD34 selection and engraftment kinetics PBSC were collected by leukophereses on two consecutive days, except in one 70-year old donor (patient #6) who had to undergo 4 consecutive leukophereses (and two CD34 selection procedures) because of poor yields. Most donors experienced bone pain and/or cephalalgia that were easily controlled with paracetamol, but no other complication was noted. A median of 10.15 (5.59 to 21.02) ×10 6 CD34 + cells/kg and 375 (127 to 656)×10 6 CD3 + cells/kg were collected CD8-depleted DLI after CD34-selected allo-PBSCT © F e r r a t a S t o r t i F o u n d a t i o n Collection of donor lymphocytes, CD8 depletion and CD8-depleted DLI Donor lymphocytes were collected on day 60 from all but 5 donors whose recipients died before or experienced serious complications Clinical data (Figure 1 and Table 4) Five patients died before receiving DLI. Patients #6 (second transplant) and #4 developed many early serious complications and died on day 81 of influenza pneumonia and on day 99 of a polymicrobial infection, respectively. Patient #19 developed severe renal and respiratory failure and died of infection at day 195. Patient #16 died of CLL and veno-occlusive disease of the liver on day 44 and patient #17 died of leukemia on day 38. The other 19 patients were in CR on day 60 and received the first DLI. Two ALL patients (patients #7 and 10) relapsed between days 60 and 100 and received the pooled 2 nd and 3 rd aliquots. Patient #7 achieved a CR with chemotherapy and DLI but relapsed later and died on day 313. Patient #10 died of leukemia on day 100. In addition, patient #12 died suddenly at home of unknown reason while enjoying continuous CR and presenting no complication other than depression. The other 16 received the scheduled 2 nd (and the 3 rd for patients #1, 2, 3, 5, 8, 9, 10, 13) DLI on days 100 (and 140). Fourteen of the 16 patients remain in CR 126 to 1344 (median 400) days post-transplantation. Patient #15 developed a central nervous system relapse on day 135, was reinduced into remission with chemotherapy and radiotherapy but relapsed again and died on day 309. Patient #3 experienced a biopsyproven massive relapse in the thymus on day 315 that completely regressed after cyclosporine discontinuation, but later relapsed again and she died on day 950. Finally, 3 patients died in CR after day 100: patient #13 died of pulmonary aspergillosis on day 351, patient #18 died suddenly at home of unknown reason on day 288 and patient #21 of acute grade IV GVHD on day 150. The remaining 11 patients were alive and disease-free 126 to 1344 (median 550) days after transplantation. Bone marrow chimerism Evaluation of bone marrow chimerism was performed in 6/7 patients with a donor of the opposite sex (n=7) by FISH with X and Y probes ( Acute and chronic GVHD (Figure 3) Acute GVHD occurred in 15 patients. It was of grade I in 9 patients, of grade II in 5 patients (3 with 1 HLA mismatch) and of grade IV in 1 patient (HLA mismatch). Thus, grade II-IV acute GVHD occurred more frequently in HLA-mismatched (4/8 or 50%) than HLA-matched (2/16 or 13%) transplants (p&lt;0.05). Before DLI, the 60-day actuarial incidence of grade II-IV GVHD was 17% (4 patients) but 2 additional patients developed grade II and IV GVHD after DLI to produce a 150-day (after DLI) incidence of 28%. For HLA-identical sibling transplants, the 60-and 150-day actuarial incidences of grade II-IV acute GVHD were 0 and 13%, respectively ( CMV reactivation Eleven of the 24 patients experienced CMV reactivation (PCR positivity) before day 60 that was successfully reversed by ganciclovir treatment and none of them presented a clinical CMV infection. Relapse and survival (Figure 4) There was no relapse in the 12 standard risk patients but 6 of the high-risk patients relapsed (p&lt;0.005) ( Discussion In agreement with previous studies, 17,19,21 CD34-selection resulted in our study in a 3.3 log elimination of T-cells while preserving hematologic reconstitution. Engraftment of neutrophils and platelets was prompt and significantly faster in patients who did not receive methotrexate. However, within the range studied, the number of © F e r r a t a S t o r t i F o u n d a t i o n CD34 + cells did not influence the speed of engraftment significantly. Prompt engraftment occurred with CD34 + cell doses as low as 1.46×10 6 /kg. Therefore, CD34 -selection preserved the engraftment capability of allogeneic PBSC. As previously suggested by others, 17,22 our results evidenced that CD34 selection reduces the risk of acute GVHD. The actuarial 60-day (before DLI) probability of grade II-IV acute GVHD was 17% in our study. This rate compares very favorably with results from studies of HLA-identical siblings receiving unmanipulated PBSC or BM. Moreover, our results also compared favorably with those of previous studies of pre-emptive DLI after T-cell-depleted BMT or PBSC transplantation. A few other studies have investigated the feasibility of adding T-cells back, also to heterogeneous groups of patients, a few weeks to a few months after T-cell-depleted (TCD) transplantation. Barrett gave either 2×10 6 /kg on day 30 and 5×10 7 /kg on day 45 or 1×10 7 /kg on day 30 to HLA-identical siblings after TCD BMT. Contributions and Acknowledgments YB designed the study and wrote the paper. FB analyzed the data and wrote the paper. JS © F e r r a t a S t o r t i F o u n d a t i o n PEER REVIEW OUTCOMES What is already known on this topic Transplantation of CD34 + selected cells from peripheral blood of allogeneic donors associates with a lower risk of acute and chronic graft-versus-host disease than unmanipulated transplants. Relapse risk may be increased in this setting, as a consequence of T-cell depletion, which leads to a decreased graft-versusleukemia effect. What this study adds CD8-depleted lymphocyte infusions starting on day 60 may be safely administered without triggering acute or chronic graft-versus-host disease. The relapse rate after this approach was similar to that observed in a control group of non-T-cell depleted transplants. Manuscript processing Potential implications for clinical practice This report demonstrates the feasibility of allogeneic CD34 + selected stem cell transplantation followed by the infusion of engineered cell-depleted fractions. Jordi Sierra Gil, Deputy Editor © F e r r a t a S t o r t i F o u n d a t i o