| 1. |
- Schael, S, et al.
(författare)
-
Precision electroweak measurements on the Z resonance
- 2006
-
Ingår i: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 427:5-6, s. 257-454
-
Forskningsöversikt (refereegranskat)abstract
- We report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electron-positron colliders SLC and LEP. The data consist of 17 million Z decays accumulated by the ALEPH, DELPHI, L3 and OPAL experiments at LEP, and 600 thousand Z decays by the SLID experiment using a polarised beam at SLC. The measurements include cross-sections, forward-backward asymmetries and polarised asymmetries. The mass and width of the Z boson, m(Z) and Gamma(Z), and its couplings to fermions, for example the p parameter and the effective electroweak mixing angle for leptons, are precisely measured: m(Z) = 91.1875 +/- 0.0021 GeV, Gamma(Z) = 2.4952 +/- 0.0023 GeV, rho(l) = 1.0050 +/- 0.0010, sin(2)theta(eff)(lept) = 0.23153 +/- 0.00016. The number of light neutrino species is determined to be 2.9840 +/- 0.0082, in agreement with the three observed generations of fundamental fermions. The results are compared to the predictions of the Standard Model (SM). At the Z-pole, electroweak radiative corrections beyond the running of the QED and QCD coupling constants are observed with a significance of five standard deviations, and in agreement with the Standard Model. Of the many Z-pole measurements, the forward-backward asymmetry in b-quark production shows the largest difference with respect to its SM expectation, at the level of 2.8 standard deviations. Through radiative corrections evaluated in the framework of the Standard Model, the Z-pole data are also used to predict the mass of the top quark, m(t) = 173(+10)(+13) GeV, and the mass of the W boson, m(W) = 80.363 +/- 0.032 GeV. These indirect constraints are compared to the direct measurements, providing a stringent test of the SM. Using in addition the direct measurements of m(t) and m(W), the mass of the as yet unobserved SM Higgs boson is predicted with a relative uncertainty of about 50% and found to be less than 285 GeV at 95% confidence level. (c) 2006 Elsevier B.V. All rights reserved.
|
|
| 2. |
|
|
| 3. |
- Abe, O, et al.
(författare)
-
Effects of chemotherapy and hormonal therapy for early breast cancer on recurrence and 15-year survival: an overview of the randomised trials
- 2005
-
Ingår i: The Lancet. - 1474-547X. ; 365:9472, s. 1687-1717
-
Tidskriftsartikel (refereegranskat)abstract
- Background Quinquennial overviews (1985-2000) of the randomised trials in early breast cancer have assessed the 5-year and 10-year effects of various systemic adjuvant therapies on breast cancer recurrence and survival. Here, we report the 10-year and 15-year effects. Methods Collaborative meta-analyses were undertaken of 194 unconfounded randomised trials of adjuvant chemotherapy or hormonal therapy that began by 1995. Many trials involved CMF (cyclophosphamide, methotrexate, fluorouracil), anthracycline-based combinations such as FAC (fluorouracil, doxombicin, cyclophosphamide) or FEC (fluorouracil, epirubicin, cyclophosphamide), tamoxifen, or ovarian suppression: none involved taxanes, trastuzumab, raloxifene, or modem aromatase inhibitors. Findings Allocation to about 6 months of anthracycline-based polychemotherapy (eg, with FAC or FEC) reduces the annual breast cancer death rate by about 38% (SE 5) for women younger than 50 years of age when diagnosed and by about 20% (SE 4) for those of age 50-69 years when diagnosed, largely irrespective of the use of tamoxifen and of oestrogen receptor (ER) status, nodal status, or other tumour characteristics. Such regimens are significantly (2p=0 . 0001 for recurrence, 2p<0 . 00001 for breast cancer mortality) more effective than CMF chemotherapy. Few women of age 70 years or older entered these chemotherapy trials. For ER-positive disease only, allocation to about 5 years of adjuvant tamoxifen reduces the annual breast cancer death rate by 31% (SE 3), largely irrespective of the use of chemotherapy and of age (<50, 50-69, &GE; 70 years), progesterone receptor status, or other tumour characteristics. 5 years is significantly (2p<0 . 00001 for recurrence, 2p=0 . 01 for breast cancer mortality) more effective than just 1-2 years of tamoxifen. For ER-positive tumours, the annual breast cancer mortality rates are similar during years 0-4 and 5-14, as are the proportional reductions in them by 5 years of tamoxifen, so the cumulative reduction in mortality is more than twice as big at 15 years as at 5 years after diagnosis. These results combine six meta-analyses: anthracycline-based versus no chemotherapy (8000 women); CMF-based versus no chemotherapy (14 000); anthracycline-based versus CMF-based chemotherapy (14 000); about 5 years of tamoxifen versus none (15 000); about 1-2 years of tamoxifen versus none (33 000); and about 5 years versus 1-2 years of tamoxifen (18 000). Finally, allocation to ovarian ablation or suppression (8000 women) also significantly reduces breast cancer mortality, but appears to do so only in the absence of other systemic treatments. For middle-aged women with ER-positive disease (the commonest type of breast cancer), the breast cancer mortality rate throughout the next 15 years would be approximately halved by 6 months of anthracycline-based chemotherapy (with a combination such as FAC or FEC) followed by 5 years of adjuvant tamoxifen. For, if mortality reductions of 38% (age <50 years) and 20% (age 50-69 years) from such chemotherapy were followed by a further reduction of 31% from tamoxifen in the risks that remain, the final mortality reductions would be 57% and 45%, respectively (and, the trial results could well have been somewhat stronger if there had been full compliance with the allocated treatments). Overall survival would be comparably improved, since these treatments have relatively small effects on mortality from the aggregate of all other causes. Interpretation Some of the widely practicable adjuvant drug treatments that were being tested in the 1980s, which substantially reduced 5-year recurrence rates (but had somewhat less effect on 5-year mortality rates), also substantially reduce 15-year mortality rates. Further improvements in long-term survival could well be available from newer drugs, or better use of older drugs.
|
|
| 4. |
- Akalin, S., et al.
(författare)
-
Intensive glucose therapy and clinical implications of recent data: a consensus statement from the Global Task Force on Glycaemic Control
- 2009
-
Ingår i: International Journal of Clinical Practice. - : Hindawi Limited. - 1742-1241 .- 1368-5031. ; 63:10, s. 1421-1425
-
Tidskriftsartikel (refereegranskat)abstract
- Background: There is compelling evidence showing that achieving good glycaemic control reduces the risk of microvascular complications in people with type 1 and type 2 diabetes. Likewise, there is clear evidence to show that achieving good glycaemic control reduces the risk of macrovascular complications in type 1 diabetes. The UKPDS 10-year follow up suggests that good glycaemic control also reduces the risk of macrovascular complications in type 2 diabetes. Despite this, recent results from ACCORD, ADVANCE and VADT present conflicting results and data from the ACCORD trial appear to suggest that very low HbA(1c) targets (< 6.0%) may, in fact, be dangerous in certain patient populations. Aim: To review recent results from ACCORD, ADVANCE and VADT and provide clear guidance on the clinical significance of the new data and their implications for the practising physician treating patients with type 2 diabetes. Methods: A Pubmed search was used to identify major randomised clinical trials examining the association between glycaemic control and diabetes-associated complications. The data was reviewed and discussed by the GTF through a consensus meeting. The recommendations for clinical practice in this statement are the conclusions of these analyses and discussions. Results: Evidence from ACCORD, ADVANCE, VADT and UKPDS suggests that certain patient populations, such as those with moderate diabetes duration and/or no pre-existing CVD, may benefit from intensive blood glucose control. These trials highlight the benefit of a multifactorial treatment approach to diabetes. However, ACCORD results indicate that aggressive HbA(1c) targets (< 6.0%) may not be beneficial in patients with existing CVD and a longer duration of diabetes. Conclusions: Glycaemic control remains a very important component of treatment for type 2 diabetes and contrasting results from the ACCORD, ADVANCE and VADT should not discourage physicians from controlling blood glucose levels.
|
|
| 5. |
- Zhao, Zhi, et al.
(författare)
-
Experimental realization of optimal asymmetric cloning and telecloning via partial teleportation
- 2005
-
Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 95:3, s. 030502-
-
Tidskriftsartikel (refereegranskat)abstract
- We report an experimental realization of both optimal asymmetric cloning and telecloning of single photons by making use of partial teleportation of an unknown state. In the experiment, we demonstrate that, conditioned on the success of partial teleportation of single photons, not only the optimal asymmetric cloning can be accomplished, but also one of two outputs can be transferred to a distant location, realizing the telecloning. The experimental results represent a novel way to achieve quantum cloning and may have potential applications in the context of quantum communication.
|
|
| 6. |
- Chen, Weimin, 1959-, et al.
(författare)
-
Efficient spin relaxation in InGaN/GaN and InGaN/GaMnN quantum wells : An obstacle to spin detection
- 2005
-
Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 87:19, s. 192107-
-
Tidskriftsartikel (refereegranskat)abstract
- Transient magneto-optical spectroscopy of InGaNGaN and InGaNGaMnN quantum wells reveals a spin relaxation process with a characteristic time of 50 ps. We show that the observed spin relaxation is mediated by spin flips of individual carriers rather than by direct exciton spin flips, and is proposed to occur near the bottom of the exciton band (K=0). Nearly complete thermalization between spin sublevels of the excitons, observed immediately after the pulsed photoexcitation, is attributed to even faster spin relaxation of photogenerated hot carriers/excitons accompanying momentum and energy relaxation at high K vectors. © 2005 American Institute of Physics.
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
- Chen, Weimin, 1959-, et al.
(författare)
-
Spin relaxation in InGaN/Ga(Mn)N quantum wells
- 2005
-
Ingår i: Bulletin of the American physical society. - 0003-0503. ; 50, s. 609-609
-
Tidskriftsartikel (refereegranskat)abstract
- Proc. 2005 APS March Meeting, March 21-25, 2005; Los Angeles, CA, USA
|
|
| 10. |
|
|
