Frequency-comb spectroscopy on pure quantum states of a single molecular ion

Spectroscopy is a powerful tool for studying molecules and is commonly performed on large thermal molecular ensembles that are perturbed by motional shifts and interactions with the environment and one another, resulting in convoluted spectra and limited resolution. Here, we use quantum-logic techniques to prepare a trapped molecular ion in a single quantum state, drive terahertz rotational transitions with an optical frequency comb, and read out the final state nondestructively, leaving the molecule ready for further manipulation. We can resolve rotational transitions to 11 significant digits and derive the rotational constant of 40CaH+ to be B R = 142 501 777.9(1.7) kilohertz. Our approach is suited for a wide range of molecular ions, including polyatomics and species relevant for tests of fundamental physics, chemistry, and astrophysics.

The association between BMI and health-related quality of life in the US population: sex, age and ethnicity matters

BACKGROUND

Obesity is a major public health problem. Detailed knowledge about the relationship between body mass index (BMI) and health-related quality of life (HRQL) is important for deriving effective and cost-effective prevention and weight management strategies. This study aims to describe the sex-, age- and ethnicity-specific association between BMI and HRQL in the US adult population.

METHODS

Analyses are based on pooled cross-sectional data from 41 459 participants of the Medical Expenditure Panel Survey (MEPS) Household Component (HC) for the years 2000-2003. BMI was calculated using self-reported height and weight, and HRQL was assessed with the EuroQol five-dimensional questionnaire. Generalized additive models were fitted with a smooth function for BMI and a smooth-factor interaction for BMI with sex adjusted for age, ethnicity, poverty, smoking and physical activity. Models were further stratified by age and ethnicity.

RESULTS

The association between BMI and HRQL is inverse U-shaped with a HRQL high point at a BMI of 22 kg m^-2 in women and a HRQL high plateau at BMI values of 22-30 kg m^-2 in men. Men aged 50 years and older with a BMI of 29 kg m^-2 reported on average five-point higher visual analog scale (VAS) scores than peers with a BMI of 20 kg m^-2. The inverse U-shaped association is more pronounced in older people, and the BMI-HRQL relationship differs between ethnicities. In Hispanics, the BMI associated with the highest HRQL is higher than in white people and, in black women, the BMI-HRQL association has an almost linear negative slope.

CONCLUSIONS

The results show that a more differentiated use of BMI cutoffs in scientific discussions and daily practice is indicated. The findings should be considered in the design of future weight loss and weight management programs.

Comparing the biological washout of β+-activity induced in mice brain after 12C-ion and proton irradiation

In clinical ion beam therapy, protons as well as heavier ions such as carbon are used for treatment. For protons, β(+)-emitters are only induced by fragmentation reactions in the target (target fragmentation), whereas for heavy ions, they are additionally induced by fragmentations of the projectile (further referred to as autoactivation). An approach utilizing these processes for treatment verification, by comparing measured Positron Emission Tomography (PET) data to predictions from Monte Carlo simulations, has already been clinically implemented. For an accurate simulation, it is important to consider the biological washout of β(+)-emitters due to vital functions. To date, mathematical expressions for washout have mainly been determined by using radioactive beams of (10)C- and (11)C-ions, both β(+)-emitters, to enhance the counting statistics in the irradiated area. Still, the question of how the choice of projectile (autoactivating or non-autoactivating) influences the washout coefficients, has not been addressed. In this context, an experiment was carried out at the Heidelberg Ion Beam Therapy Center with the purpose of directly comparing irradiation-induced biological washout coefficients in mice for protons and (12)C-ions. To this aim, mice were irradiated in the brain region with protons and (12)C-ions and measured after irradiation with a PET/CT scanner (Siemens Biograph mCT). After an appropriate waiting time, the mice were sacrificed, then irradiated and measured again under similar conditions. The resulting data were processed and fitted numerically to deduce the main washout parameters. Despite the very low PET counting statistics, a consistent difference could be identified between (12)C-ion and proton irradiated mice, with the (12)C data being described best by a two component fit with a combined medium and slow washout fraction of 0.50 ± 0.05 and the proton mice data being described best by a one component fit with only one (slow) washout fraction of 0.73 ± 0.06.

An experimental approach to improve the Monte Carlo modelling of offline PET/CT-imaging of positron emitters induced by scanned proton beams

We report on the experimental campaign carried out at the Heidelberg Ion-Beam Therapy Center (HIT) to optimize the Monte Carlo (MC) modelling of proton-induced positron-emitter production. The presented experimental strategy constitutes a pragmatic inverse approach to overcome the known uncertainties in the modelling of positron-emitter production due to the lack of reliable cross-section data for the relevant therapeutic energy range. This work is motivated by the clinical implementation of offline PET/CT-based treatment verification at our facility. Here, the irradiation induced tissue activation in the patient is monitored shortly after the treatment delivery by means of a commercial PET/CT scanner and compared to a MC simulated activity expectation, derived under the assumption of a correct treatment delivery. At HIT, the MC particle transport and interaction code FLUKA is used for the simulation of the expected positron-emitter yield. For this particular application, the code is coupled to externally provided cross-section data of several proton-induced reactions. Studying experimentally the positron-emitting radionuclide yield in homogeneous phantoms provides access to the fundamental production channels. Therefore, five different materials have been irradiated by monoenergetic proton pencil beams at various energies and the induced β(+) activity subsequently acquired with a commercial full-ring PET/CT scanner. With the analysis of dynamically reconstructed PET images, we are able to determine separately the spatial distribution of different radionuclide concentrations at the starting time of the PET scan. The laterally integrated radionuclide yields in depth are used to tune the input cross-section data such that the impact of both the physical production and the imaging process on the various positron-emitter yields is reproduced. The resulting cross-section data sets allow to model the absolute level of measured β(+) activity induced in the investigated targets within a few per cent. Moreover, the simulated distal activity fall-off positions, representing the central quantity for treatment monitoring in terms of beam range verification, are found to agree within 0.6 mm with the measurements at different initial beam energies in both homogeneous and heterogeneous targets.

Heralded photonic interaction between distant single ions

We establish a heralded interaction between two remotely trapped single (40)Ca(+) ions through the exchange of single photons. In the sender ion, we release single photons with a controlled temporal shape on the P(3/2) to D(5/2) transition and transmit them to the distant receiver ion. Individual absorption events in the receiver ion are detected by quantum jumps. For continuously generated photons, the absorption reduces significantly the lifetime of the long-lived D(5/2) state. For triggered single-photon transmission, we observe a coincidence between the emission at the sender and quantum jump events at the receiver.

Clinicopathological differences between breast cancer in patients with primary metastatic disease and those without: a multicentre study

OBJECTIVE

Approximately 6% of breast cancer (BC) patients present with primary metastatic disease (pmBC) at first diagnosis. The clinicopathological differences between tumours from patients who have metastatic disease and those who do not are unclear.

METHODS

This study was an exploratory analysis of patients with pmBC treated in 8 German breast cancer centres between 1998 and 2010. Phenotypes were defined using the following immunohistochemical markers: oestrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (Her2). The control arm included the group of patients who had neither local recurrence nor distant metastases at a follow-up of at least 30 months after initial diagnosis.

RESULTS

A total of 2214 patients were included. Of these, 1642 had non metastatic BC, and 572 had pmBC. Eighty-five patients (15%) with pmBC were diagnosed at stage T1. On multivariate analysis, factors associated with pmBC were as follows: positive lymph node status, grade 3, lobular histology and Luminal B phenotype (Her 2 positive). Of the sample, 197 patients (34%) with pmBC were diagnosed as stage T2, 90 patients (16%) were diagnosed as stage T3, and 200 patients (35%) were diagnosed as stage T4. Only positive lymph node status and grade 3 were reported as risk factors for distant metastases in patients with stage T3 and T4 cancer.

CONCLUSION

There are differences in the clinicopathological features among breast cancer patients with primary metastases and those without. Receptor expression and histological type play a minor role in the risk for metastasis in patients with stage T3 and T4 disease when compared to patients with T1 pmBC tumours. On initial diagnosis, lobular histology and Luminal B positivity (Her 2 positive) in T1 pmBC were determined to be risk factors for primary metastatic disease.

Parameters for calcium metabolism in women with polycystic ovary syndrome who undergo clomiphene citrate stimulation: a prospective cohort study

OBJECTIVE

To evaluate whether parameters for calcium metabolism were associated with characteristics of polycystic ovary syndrome (PCOS).

DESIGN

A prospective cohort study.

METHODS

Ninety-one anovulatory, infertile women with PCOS patients underwent clomiphene citrate (CC) stimulation. Main outcome measures were parathyroid hormone (PTH); 25-hydroxyvitamin D3 (25OHD3); serum levels of calcium, phosphorus, magnesium, albumin, and total protein; the serum calcium-phosphorus product; LH; FSH; sexual hormone binding globulin; testosterone; and androstenedione.

RESULTS

PTH correlated inversely with serum calcium (r=-0.235; P=0.004) and 25OHD3 (r=-0.664; P<0.001), whereas positive correlations were found between PTH and body mass index (BMI; r=0.270; P=0.010) and between PTH and testosterone (r=0.347; P=0.001). After stimulation with 50 mg CC, 57.1% (52/91) developed a follicle, whereas 26.4% (24/91) became pregnant. In a multivariate model to predict both follicle development and pregnancy, BMI and 25OHD3 deficiency were significant predictive parameters.

CONCLUSIONS

25OHD3 deficiency was an independent predictive parameter of CC stimulation outcome, in terms of follicle development and pregnancy. Our results suggest a substantial role of vitamin D in PCOS and infertility treatment in these patients.

P4-10-07: Clinico-Pathologic Features of Breast Cancer Patients with Primary Metastatic Disease Versus Localized Disease: A Multicenter Study

Objective: Approximately 6% of breast cancer patients present with primary metastatic disease (pmBC) at first diagnosis. Clinicopathological differences to non-metastatic patients are undetermined.

Methods: Exploratory analysis of patients with pmBC treated in 8 breast cancer units between 1998 and 2010. Tumor characteristics of these patients were compared with non-metastatic breast cancer patients (BC) of one breast cancer center who had neither local-recurrence nor distant metastases during 30 months of follow-up after first diagnosis. Standard staging in patients with first diagnosis of BC included chest X-ray, abdominal ultrasonography and bone scan. Molecular subtypes were analyzed and defined by immunohistochemical markers (ER, PR, Her2-receptor).

Results: 2.214 patients were included, 1.642 with BC and 572 with pmBC, respectively. Patients with pmBC were 7 years older (BC 58 years of age vs. pmBC 65 years; p=0.000) and were more likely to be postmenopausal (74% vs. 83%; p=0.000). Most common localizations of distant first metastases were bone (61,5%), liver (24%), lung (21%) and non-axillary lymph nodes (12%).

85 (15%) patients with pmBC were diagnosed in stage T1. Factors associated with pmBC in multivariate analysis for this group were positive lymph node status (OR 3.4; 95%CI 2.3−6.0; p=0.000), grading 3 (OR 2.3; 95%CI 1.3−4.0; p=0.003), lobular histology (OR 2.3; 95%CI 1.2−4.5; p=0,010) and phenotype Luminal B (OR 2.4; 95%CI 1.25−5.0; p=0.014). 197 (34%) patients with pmBC were diagnosed in stage T2; positive lymph node status (OR 4.8; 95%CI 1.1−3.0; p=0.017) and grading 3 (OR 1.6; 95% CI 1.6−2.3; p=0.019) were reported as risk factors for this group. 90 (16%) and 200 (35%) patients were diagnosed with stages T3 and T4, respectively. In T3/4 tumors a positive lymph node status (OR 5.2; 95% CI 2.9−9.3; p=0.000) and grading 3 (OR 2.2; 95%CI 1.2−3.9; p=0.009) could be defined as significant risk factors for distant metastases. Postmenopausal status was associated with primary metastases in stage T2 (OR 1.8; 95%CI 1.2−2.9; p=0.008) and T3/4 (OR 2.4; 95%CI 1.2−4.7; p=0.011) but not in T1 tumors (OR 1.3; 95%CI 0.7−2.1; p=0.420). There was no association with hormone or Her2 receptor status nor with a specific phenotype for T2-4 tumors.

Conclusion: The clinico-pathological features of breast cancer patients with or without primary metastases differ. In all stages positive lymph node status and higher grading were associated with pmBC significantly. Lobular histology was reported as a risk factor for T1-2 compared to patients without metastases. This feature was not found for T3/4 pmBC. T1 pmBC were likely to be associated with luminal B phenotype. T3-4 pmBC have not been associated with any phenotype or hormone receptor constellation as risk factor for metastases. Tumor biology seems to play a minor role for risk of metastases in T3-4 stages compared to patients with T1-tumors. Findings from this analysis should be considered in the choice of staging methods, especially in stage T1.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-10-07.