Mapping a 50-spin-qubit network through correlated sensing.

Spins associated to optically accessible solid-state defects have emerged as a versatile platform for exploring quantum simulation, quantum sensing and quantum communication. Pioneering experiments have shown the sensing, imaging, and control of multiple nuclear spins surrounding a single electron spin defect. However, the accessible size of these spin networks has been constrained by the spectral resolution of current methods. Here, we map a network of 50 coupled spins through high-resolution correlated sensing schemes, using a single nitrogen-vacancy center in diamond. We develop concatenated double-resonance sequences that identify spin-chains through the network. These chains reveal the characteristic spin frequencies and their interconnections with high spectral resolution, and can be fused together to map out the network. Our results provide new opportunities for quantum simulations by increasing the number of available spin qubits. Additionally, our methods might find applications in nano-scale imaging of complex spin systems external to the host crystal.

Electrical tuning of single nitrogen-vacancy center optical transitions enhanced by photoinduced fields.

We demonstrate precise control over the zero-phonon optical transition energies of individual nitrogen-vacancy (NV) centers in diamond by applying multiaxis electric fields, via the dc Stark effect. The Stark shifts display surprising asymmetries that we attribute to an enhancement and rectification of the local electric field by photoionized charge traps in the diamond. Using this effect, we tune the excited-state orbitals of strained NV centers to degeneracy and vary the resulting degenerate optical transition frequency by >10 GHz, a scale comparable to the inhomogeneous frequency distribution. This technique will facilitate the integration of NV-center spins within photonic networks.

Spin-light coherence for single-spin measurement and control in diamond.

The exceptional spin coherence of nitrogen-vacancy centers in diamond motivates their function in emerging quantum technologies. Traditionally, the spin state of individual centers is measured optically and destructively. We demonstrate dispersive, single-spin coupling to light for both nondestructive spin measurement, through the Faraday effect, and coherent spin manipulation, through the optical Stark effect. These interactions can enable the coherent exchange of quantum information between single nitrogen-vacancy spins and light, facilitating coherent measurement, control, and entanglement that is scalable over large distances.

Social protection to support vulnerable children and families: the potential of cash transfers to protect education, health and nutrition.

Investing in social protection in sub-Saharan Africa has taken on a new urgency as HIV and AIDS interact with other drivers of poverty to simultaneously destabilise livelihoods systems and family and community safety nets. Cash transfer programmes already reach millions of people in South Africa, and in other countries in southern and East Africa plans are underway to reach tens and eventually hundreds of thousands more. Cash transfers worldwide have demonstrated large impacts on the education, health and nutrition of children. While the strongest evidence is from conditional cash transfer evaluations in Latin America and Asia, important results are emerging in the newer African programmes. Cash transfers can be implemented in conjunction with other services involving education, health, nutrition, social welfare and others, including those related to HIV and AIDS. HIV/AIDS-affected families are diverse with respect to household structure, ability to work and access to assets, arguing for a mix of approaches, including food assistance and income-generation programmes. However, cash transfers appear to offer the best strategy for scaling up to a national system of social protection, by reaching families who are the most capacity constrained, in large numbers, relatively quickly. These are important considerations for communities hard-hit by HIV and AIDS, given the extent and nature of deprivation, the long-term risk to human capital and the current political willingness to act.

Breast imaging: mammography and ultrasonography.

Mammography is the primary imaging for breast cancer screening and diagnosis. Recent improvements in mammography are related to programs established by professional societies and government agencies to bring standardization and quality assurance in the technical improvements that have extended its contributions to breast imaging. This article addresses the current roles and limitations of mammography and ultrasonography in the detection and diagnosis of breast cancer.

Stereotactic core-needle breast biopsy: a multi-institutional prospective trial.

PURPOSE: To assess the accuracy of stereotactic core-needle biopsy (CNB) of nonpalpable breast lesions within the context of clinically important parameters of anticipated tissue-sampling error and concordance with mammographic findings. MATERIALS AND METHODS: CNB was performed in 1,003 patients, with results validated at surgery or clinical and mammographic follow-up. Mammographic findings were scored according to the American College of Radiology Breast Imaging Reporting and Data System with a similar correlative scale for histopathologic samples obtained at either CNB or surgery. Agreement of CNB findings with surgical findings or evidence of no change during clinical and mammographic follow-up (median, 24 months) for benign lesions was used to determine results. Three forms of diagnostic discrimination measures (strict, working [strict conditioned by tissue sampling error], applied [working conditioned by concordance of imaging and CNB findings) were used to evaluate the correlation of CNB, surgical, and follow-up results. RESULTS: Strict, working, and applied sensitivities were 91% +/- 1.9; 92% +/- 1.8, and 98% +/- 0.9, respectively; strict, working, and applied specificities were 100%, 98% +/- 0.8, and 73% +/- 0.9; strict, working, and applied accuracies were 97%, 96%, and 79%. CONCLUSION: Percutaneous stereotactic CNB is an accurate method to establish a histopathologic diagnosis of nonpalpable breast lesions. Accuracy increases when additional surgery is performed for lesions with anticipated sampling error or when CNB findings are discordant with mammographic findings. An understanding of the interrelationship among these parameters is necessary to properly assess results.

Decision analysis for the cost effectiveness of sestamibi scintimammography in minimizing unnecessary biopsies.

BACKGROUND: The purpose of this study was to assess if breast cancer screening using sestamibi scintimammography (SSMM) in conjunction with mammography (MM) is cost effective in avoiding biopsies in healthy patients. METHODS: Quantitative decision tree sensitivity analysis was used to compare the conventional MM alone strategy (strategy A) with two decision strategies for screening with SSMM; SSMM after an indeterminate mammogram (strategy B) or SSMM after both a positive and an indeterminate mammogram (strategy C). Cost effectiveness was measured by calculating the expected cost per patient and the average life expectancy per patient for baseline values as well as over a range of values for all of the variables of each strategy. RESULTS: Based on Medicare reimbursement values, strategies B and C showed a cost savings of $9 and $20 per patient respectively as compared to strategy A. This translates into respective savings of $189 and $420 million per year assuming 21 million females undergo screening each year. Strategies B and C did however have a loss of mean life expectancy of 0.000178 and 0.000222 years respectively as compared to strategy A due to interval progression of breast cancer in a small number of women. Strategies B and C significantly lowered the number of biopsies performed on healthy patients in the screening population by 750,063 and 1,557,915 biopsies respectively as compared to strategy A. CONCLUSIONS: These results quantitatively verify the potential utility of using SSMM in avoiding unnecessary biopsies.

Imaging of breast masses.

The American College of Radiology Breast Imaging and Reporting Data System (ACR BI-RADS) defines a mass as a space-occupying lesion seen in at least two projections. This article focuses on the management of breast masses with mammography and ultrasonography. Recommended work-up pathways are modified for nonpalpable masses, palpable masses in women over the age of 30, and palpable masses in women under the age of 30. The suggested protocols are based on scientific peer-reviewed literature whenever possible, but when evidence based studies are not available, the author relies on expert opinion.

Reasons for failure of a mammography unit at clinical image review in the American College of Radiology Mammography Accreditation Program.

PURPOSE: To identify the most common deficiencies in the quality of mammograms submitted for clinical image evaluation (evaluation of image from actual patient referred for mammography). MATERIALS AND METHODS: In 1997, the American College of Radiology Mammography Accreditation Program reviewed clinical images for 2,341 mammography units. For each mammography unit, the facility submitted bilateral mediolateral oblique and craniocaudal mammograms obtained in a woman with fatty breasts and a woman with dense breasts. Images were reviewed independently by two experienced radiologists. Reviewers listed the general categories and specific deficiencies that led to a decision to fail the unit that produced the clinical images. RESULTS: Of the 2,341 mammography units, 1,034 (44%) failed the clinical image evaluation process. Of 6,128 categories cited by reviewers as deficient, 1,250 (20%) involved problems in positioning; 944 (15%), exposure; 887 (14%), compression; 806 (13%), sharpness; 785 (13%), contrast; 703 (11%), labeling; 465 (8%), artifacts; and 288 (5%), noise. A significantly higher proportion of failures was attributed to positioning deficiencies for fatty breasts than for dense breasts (P =.028). Higher proportions of failures in dense breasts were related to compression (P <.001) and exposure (P <.001) deficiencies. CONCLUSION: Common problems in clinical image quality have been identified. This information should be useful for educators and facilities striving to improve the quality of mammography.

Functional speech outcomes after laryngectomy and pharyngolaryngectomy.

OBJECTIVE: To compare and contrast functional speech outcomes of patients having undergone total laryngectomy and pharyngolaryngectomy who use tracheoesophageal speech as their primary mode of communication. DESIGN: Group comparison design. SETTING: Adult acute tertiary care hospital. PATIENTS: Thirty patients who underwent total laryngectomy and 13 who underwent pharyngolaryngectomy with free jejunal interposition reconstruction. All patients used tracheoesophageal speech. INTERVENTION: Group comparisons across measures of speech intelligibility, voice quality, tracheoesophageal speech use, voice satisfaction and levels of perceived voice disability, handicap, and well-being/distress. MAIN OUTCOME MEASURE: The existence of any significant differences between the 2 groups on measures of intelligibility, voice quality, tracheoesophageal speech use, and voice satisfaction and levels of voice disability, handicap, and well-being/distress. RESULTS: Statistical comparisons confirmed reduced functional intelligibility (P<.05), reduced vocal quality (P<.01), and higher levels of disability (P<.05) in the pharyngolaryngectomy group. However, no significant difference was observed between the proportion of patients classified as "successful" tracheoesophageal speech users in either group. Low levels of handicap and high levels of patient well-being were recorded in both groups. CONCLUSION: Despite the perceptual differences in voice quality and intelligibility observed between the 2 groups, tracheoesophageal speech that is functional, effective, and perceived by the patients as satisfactory can be achieved after total laryngectomy and pharyngolaryngectomy with free jejunal interposition reconstruction.

Severe haemophilia A in a female: a compound heterozygote with nonrandom X-inactivation.

We report a case of severe haemophilia A (<1% factor VIII level) in a female resulting from an interesting and improbable combination of events. The patient inherited a factor VIII intron 22 inversion from her carrier mother, as well as a second factor VIII inversion involving intron 22 that arose de novo on her paternally derived X chromosome. In addition, the patient's paternally derived X chromosome had been preferentially inactivated in 95+% of her somatic cells. The patient's mother, who was clinically unaffected, carried an intron 22 inversion as well and also showed nonrandom X-inactivation. The patient's mother had a brother with severe haemophilia A. It is therefore likely that the mother's inversion was on her maternally derived X chromosome. Since she was unaffected, it is likely that her inversion-bearing X was the one that was preferentially inactivated.

Benign versus malignant solid breast masses: US differentiation.

PURPOSE: To investigate the general applicability and interobserver variability of ultrasonographic (US) features in differentiating benign from malignant solid breast masses. MATERIALS AND METHODS: One hundred sixty-two consecutive solid masses with a tissue diagnosis were reviewed. Three radiologists reviewed the masses without knowledge of clinical history or histologic examination results. RESULTS: US features that most reliably characterize masses as benign were a round or oval shape (67 of 71 [94%] were benign), circumscribed margins (95 of 104 [91%] were benign), and a width-to-anteroposterior (AP) dimension ratio greater than 1.4 (82 of 92 [89%] were benign). Features that characterize masses as malignant included irregular shape (19 of 31 [61%] were malignant), microlobulated (four of six [67%] were malignant) or spiculated (two of three [67%] were malignant) margins, and width-to-AP dimension ratio of 1.4 or less (28 of 70 [40%] were malignant). If the three most reliable criteria had been strictly applied by each radiologist, the overall cancer biopsy yield would have increased (from 23% to 39%) by 16%. When US images and mammograms were available, the increase in biopsy yield contributed by US was not statistically significant (2%, P = .73). However, in independent reviews, one to three reviewers interpreted four carcinomas as benign at US. CONCLUSION: The data confirm that certain US features can help differentiate benign from malignant masses. However, practice and interpreter variability should be further explored before these criteria are generally applied to defer biopsy of solid masses.

A study on the cost effectiveness of sestamibi scintimammography for screening women with dense breasts for breast cancer.

The potential impact of Sestamibi scintimammography (SSMM) on the cost effective management of women with dense breasts is not known. This study addresses this issue quantitatively by examining the impact of SSMM based screening strategies on the approximately 3,000,000 women over 40 with very dense breasts (DY patterns) without palpable masses and who have had one or more prior mammograms, who undergo routine screening each year. Quantitative decision tree sensitivity analysis was used to compare the conventional mammography (MM) strategy (strategy A), which does not subject patients with negative mammograms to any further examination until their next screening, with two decision strategies for screening with SSMM; SSMM after a negative mammogram (strategy B) or SSMM as the only screening test for women already identified as having dense breasts by a previous mammogram (strategy C). Cost effectiveness was measured by calculating the incremental cost effectiveness ratio (ICER) of strategies B and C, which is the cost of achieving an additional year of life in the screening population by choosing a SSMM based decision strategy rather than the conventional strategy. Strategies B and C reduced the number of false negative diagnoses by 62% and 8%, respectively. The ICER was $632,000 and $3.18M per life year for strategy B and C, respectively. To be cost effective, the pre-test probability of cancer in the study population must be greater than 3% for strategy B or the cost of SSMM must be less than $50 for strategy C. These results show the ICER of an SSMM based breast cancer screening strategy in the management of patients with dense breasts is not currently within the range (approximately $50,000 per year life saved) of other commonly performed medical interventions that are considered cost effective.

Effects of estrogen and estrogen-progestin on mammographic parenchymal density. Postmenopausal Estrogen/Progestin Interventions (PEPI) Investigators.

BACKGROUND: In longitudinal studies, greater mammographic density is associated with an increased risk for breast cancer. OBJECTIVE: To assess differences between placebo, estrogen, and three estrogen-progestin regimens on change in mammographic density. DESIGN: Subset analysis of a 3-year, multicenter, double-blind, randomized, placebo-controlled trial. SETTING: Seven ambulatory study centers. PARTICIPANTS: 307 of the 875 women in the Postmenopausal Estrogen/Progestin Interventions Trial. Participants had a baseline mammogram and at least one follow-up mammogram available, adhered to treatment, had not taken estrogen for at least 5 years before baseline, and did not have breast implants. INTERVENTION: Treatments were placebo, conjugated equine estrogens (CEE), CEE plus cyclic medroxyprogesterone acetate (MPA), CEE plus daily MPA, and CEE plus cyclic micronized progesterone (MP). MEASUREMENTS: Change in radiographic density (according to American College of Radiology Breast Imaging Reporting and Data System grades) on mammography. RESULTS: Almost all increases in mammographic density occurred within the first year. At 12 months, the percentage of women with density grade increases was 0% (95% CI, 0.0% to 4.6%) in the placebo group, 3.5% (CI, 1.0% to 12.0%) in the CEE group, 23.5% (CI, 11.9% to 35.1%) in the CEE plus cyclic MPA group, 19.4% (CI, 9.9% to 28.9%) in the CEE plus daily MPA group, and 16.4% (CI, 6.6% to 26.2%) in the CEE plus cyclic MP group. At 12 months, the odds of an increase in mammographic density were 13.1 (95% CI, 2.4 to 73.3) with CEE plus cyclic MPA, 9.0 (CI, 1.6 to 50.1) with CEE plus daily MPA, and 7.2 (CI, 1.3 to 40.0) with CEE plus cyclic micronized progesterone compared with CEE alone. CONCLUSIONS: Further study of the magnitude and meaning of increased mammographic density due to use of estrogen and estrogen-progestins is warranted because mammographic density may be a marker for risk for breast cancer.