396 research outputs found
Prostate radiation in non-metastatic castrate refractory prostate cancer provides an interesting insight into biology of prostate cancer
<p>Abstract</p> <p>Background</p> <p>The natural history of non-metastatic castrate refractory prostate cancer is unknown and treatment options are limited. We present a retrospective review of 13 patients with locally advanced or high risk prostate cancer, initially treated with hormone monotherapy and then treated with prostate radiation after becoming castration refractory.</p> <p>Findings</p> <p>Median PSA response following prostate radiation was 67.4%. Median time to biochemical progression following radiotherapy was 15 months and to detection of metastatic disease was 18.5 months. Median survival from castration resistance (to date of death or November 2011) was 60 months, with median survival from RT 42 months.</p> <p>Conclusion</p> <p>Prostate radiation appears to be beneficial even in patients with potential micrometastatic disease, which supports the hypothesis that the primary tumour is important in the progression of prostate cancer. These results are an interesting addition to the literature on the biology of prostate cancer especially as this data is unlikely to be available in the future due to combined prostate radiation and androgen deprivation therapy now being the standard of care.</p
Cohesive properties of alkali halides
We calculate cohesive properties of LiF, NaF, KF, LiCl, NaCl, and KCl with
ab-initio quantum chemical methods. The coupled-cluster approach is used to
correct the Hartree-Fock crystal results for correlations and to systematically
improve cohesive energies, lattice constants and bulk moduli. After inclusion
of correlations, we recover 95-98 % of the total cohesive energies. The lattice
constants deviate from experiment by at most 1.1 %, bulk moduli by at most 8 %.
We also find good agreement for spectroscopic properties of the corresponding
diatomic molecules.Comment: LaTeX, 10 pages, 1 figure, accepted by Phys. Rev.
Interpolated wave functions for nonadiabatic simulations with the fixed-node quantum Monte Carlo method
Simulating nonadiabatic effects with many-body wave function approaches is an
open field with many challenges. Recent interest has been driven by new
algorithmic developments and improved theoretical understanding of properties
unique to electron-ion wave functions. Fixed-node diffusion Monte Caro is one
technique that has shown promising results for simulating electron-ion systems.
In particular, we focus on the CH molecule for which previous results suggested
a relatively significant contribution to the energy from nonadiabatic effects.
We propose a new wave function ansatz for diatomic systems which involves
interpolating the determinant coefficients calculated from configuration
interaction methods. We find this to be an improvement beyond previous wave
function forms that have been considered. The calculated nonadiabatic
contribution to the energy in the CH molecule is reduced compared to our
previous results, but still remains the largest among the molecules under
consideration.Comment: 7 pages, 3 figure
Dentin dysplasia type I: a challenge for treatment with dental implants
<p>Abstract</p> <p>Background</p> <p>Dentin dysplasia type I is characterized by a defect of dentin development with clinical normal appearance of the permanent teeth but no or only rudimentary root formation. Early loss of all teeth and concomitant underdevelopment of the jaws are challenging for successful treatment with dental implants.</p> <p>Methods</p> <p>A combination of sinus lifting and onlay bone augmentation based on treatment planning using stereolithographic templates was used in a patient with dentin dysplasia type I to rehabilitate the masticatory function.</p> <p>Results</p> <p>(i) a predisposition for an increased and accelerated bone resorption was observed in our patient, (ii) bone augmentation was successful using a mixture of allogenic graft material with autogenous bone preventing fast bone resorption, (iii) surgical planning, based on stereolithographic models and surgical templates, facilitated the accurate placement of dental implants.</p> <p>Conclusion</p> <p>Bony augmentation and elaborate treatment planning is helpful for oral rehabilitation of patients with dentin dysplasia type I.</p
Trends in non-metastatic prostate cancer management in the Northern and Yorkshire region of England, 2000–2006
Background:
Our objective was to analyse variation in non-metastatic prostate cancer management in the Northern and Yorkshire region of England.
Methods:
We included 21 334 men aged ⩾55, diagnosed between 2000 and 2006. Principal treatment received was categorised into radical prostatectomy (11%), brachytherapy (2%), external beam radiotherapy (16%), hormone therapy (42%) and no treatment (29%).
Results:
The odds ratio (OR) for receiving a radical prostatectomy was 1.53 in 2006 compared with 2000 (95% CI 1.26–1.86), whereas the OR for receiving hormone therapy was 0.57 (0.51–0.64). Age was strongly associated with treatment received; radical treatments were significantly less likely in men aged ⩾75 compared with men aged 55–64 years, whereas the odds of receiving hormone therapy or no treatment were significantly higher in the older age group. The OR for receiving radical prostatectomy, brachytherapy or external beam radiotherapy were all significantly lower in the most deprived areas when compared with the most affluent (0.64 (0.55–0.75), 0.32 (0.22–0.47) and 0.83 (0.74–0.94), respectively) whereas the OR for receiving hormone therapy was 1.56 (1.42–1.71).
Conclusions:
This study highlights the variation and inequalities that exist in the management of non-metastatic prostate cancer in the Northern and Yorkshire region of England
Theoretical investigation of the electronic structure of Fe(II) complexes at spin-state transitions
The electronic structure relevant to low spin (LS)high spin (HS) transitions in Fe(II) coordination compounds with a FeN6 core are studied. The selected [Fe(tz)6]2+(1) (tz=1H-tetrazole), [Fe(bipy)3]2+(2) (bipy=2,2’-bipyridine) and [Fe(terpy)2]2+ (3) (terpy=2,2’:6’,2’’-terpyridine) complexes have been actively studied experimentally, and with their respective mono-, bi-, and tridentate ligands, they constitute a comprehensive set for theoretical case studies. The methods in this work include density functional theory (DFT), time-dependent DFT (TD-DFT) and multiconfigurational second order perturbation theory (CASPT2). We determine the structural parameters as well as the energy splitting of the LS-HS states (ΔEHL) applying the above methods, and comparing their performance. We also determine the potential energy curves representing the ground and low-energy excited singlet, triplet, and quintet d6 states along the mode(s) that connect the LS and HS states. The results indicate that while DFT is well suited for the prediction of structural parameters, an accurate multiconfigurational approach is essential for the quantitative determination of ΔEHL. In addition, a good qualitative agreement is found between the TD-DFT and CASPT2 potential energy curves. Although the TD-DFT results might differ in some respect (in our case, we found a discrepancy at the triplet states), our results suggest that this approach, with due care, is very promising as an alternative for the very expensive CASPT2 method. Finally, the two dimensional (2D) potential energy surfaces above the plane spanned by the two relevant configuration coordinates in [Fe(terpy)2]2+ were computed both at the DFT and CASPT2 levels. These 2D surfaces indicate that the singlet-triplet and triplet-quintet states are separated along different coordinates, i.e. different vibration modes. Our results confirm that in contrast to the case of complexes with mono- and bidentate ligands, the singlet-quintet transitions in [Fe(terpy)2]2+ cannot be described using a single configuration coordinate
Outcome after surgery for metastatic spinal cord compression in 54 patients with prostate cancer
Tailored treatment including radical prostatectomy and radiation therapy + androgen deprivation therapy versus exclusive radical prostatectomy in high-risk prostate cancer patients: results from a prospective study
Purpose To evaluate outcomes of patients with high risk prostate cancer (PCa) who underwent radical prostatectomy (RP) in a context of a multidisciplinary approach including adjuvant radiation (RT) + androgen deprivation therapy (ADT). Matherials and Methods 244 consecutive patients with high risk localized PCa underwent RP and bilateral extended pelvic lymph node dissection at our institution. Adjuvant RT + 24 months ADT was carried out in subjects with pathological stage ≥ T3N0 and/or positive surgical margins or in patients with local relapse. Results After a median follow-up was 54.17 months (range 5.4-117.16), 13 (5.3%) subjects had biochemical progression, 21 (8.6%) had clinical progression, 7 (2.9%) died due to prostate cancer and 15 (6.1%) died due to other causes. 136 (55.7%) patients did not receive any adjuvant treatment while 108 (44.3%) received respectively adjuvant or salvage RT+ADT. Multivariate Cox proportional hazard analysis showed that pre-operative PSA value at diagnosis is a significant predictive factor for BCR (HR: 1.04, p < 0.05) and that Gleason Score 8-10 (HR: 2.4; p<0.05) and PSMs (HR: 2.01; p < 0.01) were significant predictors for clinical progression. Radical prostatectomy group was associated with BPFS, CPFS, CSS and OS at 5-years of 97%, 90%, 95% and 86% respectively, while adjuvant radiation + androgen deprivation therapy group was associated with a BPFS, CPFS and CSS at 5-years of 91%, 83%, 95% and 88%, without any statistical difference. Conclusions Multimodality tailored treatment based on RP and adjuvant therapy with RT+ADT achieve similar results in terms of OS after 5-years of follow-up
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