Soft Quantum Control for Highly Selective Interactions among Joint Quantum Systems

We propose a quantum control scheme aimed at interacting systems that gives rise to highly selective coupling among their near-to-resonance constituents. Our protocol implements temporal control of the interaction strength, switching it on and off again adiabatically. This soft temporal modulation significantly suppresses off-resonant contributions in the interactions. Among the applications of our method we show that it allows us to perform an efficient rotating-wave approximation in a wide parameter regime, the elimination of side peaks in quantum sensing experiments, and selective high-fidelity entanglement gates on nuclear spins with close frequencies. We apply our theory to nitrogen-vacancy centers in diamond and demonstrate the possibility for the detection of weak electron-nuclear coupling under the presence of strong perturbations.

PCA3 as a second-line biomarker in a prospective controlled randomized opportunistic prostate cancer screening programme

OBJECTIVES

PCA3 performance as a single second line biomarker is compared to the European Randomised Study of Screening for Prostate Cancer risk calculator model 3 (ERSPC RC-3) in an opportunistic screening in prostate cancer (PCa).

MATERIAL AND METHODS

5,199 men, aged 40-75y, underwent prostate-specific antigen (PSA) screening and digital rectal examination (DRE). Men with a normal DRE and PSA ≥3ng/ml had a PCA3 test done. All men with PCA3 ≥35 underwent an initial biopsy (IBx) -12 cores-. Men with PCA3 <35 were randomized 1:1 to either IBx or observation. We compared them to those obtained with ERSPC RC-3.

RESULTS

PCA3 test was performed on 838 men (16.1%). In PCA3(+) and PCA3(-) groups, global PCa detection rates were 40.9% and 14.7% with a median follow-up (FU) of 21.7 months (P<.001). In the PCA3(+) arm (n=301, 35.9%), PCa was identified in 115 men at IBx (38.2%). In the randomized arm, 256 underwent IBx and PCa was found in 46 (18.0%) (P<.001). The biopsy-sparing potential would have been 64.1% as opposed to 76.6% if we had used ERSPC RC-3. However, the estimated false negative cases for HGPCa would have been reduced by 37.1% (89 to 56 patients). Moreover, if we had applied PCA3-35 to avoid IBx, 14.7% PCa and 9.1% of clinical significant PCa patients would not have been diagnosed during this FU.

CONCLUSIONS

When PCA3-35 is used as a second-line biomarker when PSA ≥3ng/ml and DRE is normal, IBx could be avoided in 12.5% less than if ERSPC RC-3 is used and would reduce the false negative cases by 36.2%. At a FU of 21.7 months, this dual protocol would miss 9.1% of clinically significant PCa, so strict FU is mandatory with established biopsy criteria based on PSA and DRE in cases with PCA3 <35.

Extraskeletal osteosarcoma: A European Musculoskeletal Oncology Society study on 266 patients

PURPOSE

Prognosis of extraskeletal osteosarcoma (ESOS) is reported to be poorer than that of skeletal osteosarcoma. This multicenter retrospective study aimed to evaluate factors influencing ESOS prognosis.

PATIENTS AND METHODS

Members of the European Musculoskeletal Oncology Society (EMSOS) submitted institutional data on patients with ESOS.

RESULTS

Data from 274 patients treated from 1981 to 2014 were collected from 16 EMSOS centres; 266 patients were eligible. Fifty (18.7%) had metastases at diagnosis. Of 216 patients with localised disease, 211 (98%) underwent surgery (R0 = 70.6%, R1 = 27%). Five-year overall survival (OS) for all 266 patients was 47% (95% CI 40-54%). Five-year OS for metastatic patients was 27% (95% CI 13-41%). In the analysis restricted to the 211 localised patients who achieved complete remission after surgery 5-year OS was 51.4% (95% CI 44-59%) and 5-year disease-free survival (DFS) was 43% (95% CI 35-51%). One hundred twenty-one patients (57.3%) received adjuvant or neoadjuvant chemotherapy and 80 patients (37.9%) received radiotherapy. A favourable trend was seen for osteosarcoma-type chemotherapy versus soft tissue sarcoma-type (doxorubicin ± ifosfamide) regimens. For the 211 patients in complete remission after surgery, patient age, tumour size, margins and chemotherapy were positive prognostic factors for DFS and OS by univariate analysis. At multivariate analysis, patient age (≤40 years versus >40 years) (P = 0.05), tumour size (P = 0.0001) and receipt of chemotherapy (P = 0.006) were statistically significant prognostic factors for survival.

CONCLUSION

Patient age and tumour size are factors influencing ESOS prognosis. Higher survival was observed in patients who received perioperative chemotherapy with a trend in favour of multiagent osteosarcoma-type regimen which included doxorubicin, ifosfamide and cisplatin.

Congenital pulmonary lymphangiectasia and chylothorax - a case series

Congenital pulmonary lymphangiectasia (CPL) and chylothorax (CC) are rare lymphatic developmental disorders. We report six clinical cases of CPL and CC that were admitted to our level III neonatal intensive care unit over the last 20 years. One case of unilateral CC was successfully treated with pleuro-amniotic shunt; three cases of bilateral CC were associated to lung hypoplasia, hydrops fetalis, and generalized lymphangiectasias; one case of CPL was associated with obstructive congenital heart defect; one case of unilateral CC was successfully treated with thoracocentesis and medium-chain triglyceride diet. Mortality was high (66.6%).

Noise-Resilient Quantum Computing with a Nitrogen-Vacancy Center and Nuclear Spins

Selective control of qubits in a quantum register for the purposes of quantum information processing represents a critical challenge for dense spin ensembles in solid-state systems. Here we present a protocol that achieves a complete set of selective electron-nuclear gates and single nuclear rotations in such an ensemble in diamond facilitated by a nearby nitrogen-vacancy (NV) center. The protocol suppresses internuclear interactions as well as unwanted coupling between the NV center and other spins of the ensemble to achieve quantum gate fidelities well exceeding 99%. Notably, our method can be applied to weakly coupled, distant spins representing a scalable procedure that exploits the exceptional properties of nuclear spins in diamond as robust quantum memories.

Indocyanine Green Guided Pelvic Lymph Node Dissection: An Efficient Technique to Classify the Lymph Node Status of Patients with Prostate Cancer Who Underwent Radical Prostatectomy

PURPOSE

We evaluated the effectiveness of indocyanine green guided pelvic lymph node dissection for the optimal staging of prostate cancer and analyzed whether the technique could replace extended pelvic lymph node dissection.

MATERIALS AND METHODS

A solution of 25 mg indocyanine green in 5 ml sterile water was transperineally injected. Pelvic lymph node dissection was started with the indocyanine green stained nodes followed by extended pelvic lymph node dissection. Primary outcome measures were sensitivity, specificity, predictive value and likelihood ratio of a negative test of indocyanine green guided pelvic lymph node dissection.

RESULTS

A total of 84 patients with a median age of 63.55 years and a median prostate specific antigen of 8.48 ng/ml were included in the study. Of these patients 60.7% had intermediate risk disease and 25% had high or very high risk disease. A median of 7 indocyanine green stained nodes per patient was detected (range 2 to 18) with a median of 22 nodes excised during extended pelvic lymph node dissection. Lymph node metastasis was identified in 25 patients, 23 of whom had disease properly classified by indocyanine green guided pelvic lymph node dissection. The most frequent location of indocyanine green stained nodes was the proximal internal iliac artery followed by the fossa of Marcille. The negative predictive value was 96.7% and the likelihood ratio of a negative test was 8%. Overall 1,856 nodes were removed and 603 were stained indocyanine green. Pathological examination revealed 82 metastatic nodes, of which 60% were indocyanine green stained. The negative predictive value was 97.4% but the likelihood ratio of a negative test was 58.5%.

CONCLUSIONS

Indocyanine green guided pelvic lymph node dissection correctly staged 97% of cases. However, according to our data it cannot replace extended pelvic lymph node dissection. Nevertheless, its high negative predictive value could allow us to avoid extended pelvic lymph node dissection if we had an accurate intraoperative lymph fluorescent analysis.

Measuring Entanglement in a Photonic Embedding Quantum Simulator

Measuring entanglement is a demanding task that usually requires full tomography of a quantum system, involving a number of observables that grows exponentially with the number of parties. Recently, it was suggested that adding a single ancillary qubit would allow for the efficient measurement of concurrence, and indeed any entanglement monotone associated with antilinear operations. Here, we report on the experimental implementation of such a device-an embedding quantum simulator-in photonics, encoding the entangling dynamics of a bipartite system into a tripartite one. We show that bipartite concurrence can be efficiently extracted from the measurement of merely two observables, instead of 15, without full tomographic information.

Optimizing the clinical utility of PCA3 to diagnose prostate cancer in initial prostate biopsy

Background

PCA3 has been included in a nomogram outperforming previous clinical models for the prediction of any prostate cancer (PCa) and high grade PCa (HGPCa) at the initial prostate biopsy (IBx). Our objective is to validate such IBx-specific PCA3-based nomogram. We also aim to optimize the use of this nomogram in clinical practice through the definition of risk groups.

Methods

Independent external validation. Clinical and biopsy data from a contemporary cohort of 401 men with the same inclusion criteria to those used to build up the reference’s nomogram in IBx. The predictive value of the nomogram was assessed by means of calibration curves and discrimination ability through the area under the curve (AUC). Clinical utility of the nomogram was analyzed by choosing thresholds points that minimize the overlapping between probability density functions (PDF) in PCa and no PCa and HGPCa and no HGPCa groups, and net benefit was assessed by decision curves.

Results

We detect 28 % of PCa and 11 % of HGPCa in IBx, contrasting to the 46 and 20 % at the reference series. Due to this, there is an overestimation of the nomogram probabilities shown in the calibration curve for PCa. The AUC values are 0.736 for PCa (C.I.95 %:0.68–0.79) and 0.786 for HGPCa (C.I.95 %:0.71–0.87) showing an adequate discrimination ability. PDF show differences in the distributions of nomogram probabilities in PCa and not PCa patient groups. A minimization of the overlapping between these curves confirms the threshold probability of harboring PCa >30 % proposed by Hansen is useful to indicate a IBx, but a cut-off > 40 % could be better in series of opportunistic screening like ours. Similar results appear in HGPCa analysis. The decision curve also shows a net benefit of 6.31 % for the threshold probability of 40 %.

Conclusions

PCA3 is an useful tool to select patients for IBx. Patients with a calculated probability of having PCa over 40 % should be counseled to undergo an IBx if opportunistic screening is required.

[Dynamic sentinel node biopsy in penile cancer. Indications, technique and results in a Spanish oncological center]

OBJECTIVE

Penile cancer has a predominantly lymphatic dissemination. Lymph nodes metastatic involvement conditions disease prognosis and inguinal lymph node dissection has both prognostic and therapeutic value. High and intermediate risk patients with non-palpable lymph nodes will benefit of a precise diagnosis by means of selective sentinel node biopsy with minimal surgical aggressiveness.

METHODS

Retrospective review of our experience on dynamic sentinel node biopsy in penile cancer from November 1999 to July 2014.

RESULTS

We performed this procedure in 33 patients, technically successful in 29 (88%). The patients who did not undergo lymph node dissection due to positive sentinel node biopsy have been followed a mean of 60.4 months (Median 59, range 5-145). 20 patients underwent simultaneous sentinel node biopsy and surgical treatment of the primary lesion and in 13 it was performed posteriorly. In these cases the time lapse was 5.5 months (median 5, range 2-12). In 6 (18.9%) of the 29 patients successfully biopsied, metastasis was founded in any of the lymph nodes identified as sentinel. Two patients were false negative (6,25%). Sensitivity (S), specificity (Sp), positive predictive value (PPV) and negative predictive value (NPV) of successfully performed sentinel node biopsies were 66, 100, 100 and 93%, respectively.

CONCLUSION

Sentinel node biopsy enables a correct lymph node staging avoiding the morbidity of inguinal lymph node dissection. The rate of technical failure and false negative results is low and it may be considered the diagnostic technique of choice in high and intermediate risk penile cancer with non-palpable lymph nodes.

Fermion-fermion scattering in quantum field theory with superconducting circuits

We propose an analog-digital quantum simulation of fermion-fermion scattering mediated by a continuum of bosonic modes within a circuit quantum electrodynamics scenario. This quantum technology naturally provides strong coupling of superconducting qubits with a continuum of electromagnetic modes in an open transmission line. In this way, we propose qubits to efficiently simulate fermionic modes via digital techniques, while we consider the continuum complexity of an open transmission line to simulate the continuum complexity of bosonic modes in quantum field theories. Therefore, we believe that the complexity-simulating-complexity concept should become a leading paradigm in any effort towards scalable quantum simulations.

Obligatory information that a patient diagnosed of prostate cancer and candidate for an active surveillance protocol must know

OBJECTIVES

To know the necessary information to reproduce the results found in the literature on active surveillance (AS) in prostate cancer (PCa) in our own center so that the information would be objective and correctly given to the patients. We have aimed to study the percentage of candidates for AS chosen in our setting, and the data on infrastaging, subgrading and prediction of insignificant PCa, debugging the predictive value of clinical variables to improve our selection criteria and finally to analyze the results of our patients enrolled in AS.

MATERIALS AND METHODS

A retro- and prospective review of our data bases was performed. A one-year period was analyzed to know AS candidates. Analysis of our radical prostatectomy specimens for infrastaging, subgrading and prediction of insignificant PCa (Epstein's criteria) was made as well as a uni/multivariate analysis of clinical variables in patients with insignificant PCa in the specimen. A prospective validation was performed with overall survival and survival free of active treatment (SFAT) as endpoints in patients enrolled in AS.

RESULTS

Between October-2010/October-2011, 44.7% of our PCa were candidates for AS, but only 11.2% choose it. The percentages found for infrastaging, subgrading and prediction of insignificant PCa were 14%, 31.4% and 55.7%, respectively. However, only just 6 patients (6.97%) had≥pT3a+Gleason≥7+volume>0.5cc PCa. The multivariate analysis showed that PSA density and number of affected cores were independent predictors of insignificant PCa. With a mean follow-up of 36±39months, 63 out of 232 patients enrolled in AS went on to active treatment (27.1%), with only 13 due to anxiety without pathologic progression. Median time of SFAT was 72.7 months (CI 95% 30.9-114.4). SFAT at 24 months was 76.4% (69.7-83.1%) and at 48 months 58.1% (48.8-67.4%). Only 10 patients died (4.3%), 9 due to causes different of PCa. Estimated overall survival at 5 years was 92.8% (CI 95% 86.7-98.9%).

CONCLUSIONS

It should be mandatory to have the exact knowledge of the local data of each Center in order to objectively inform patients about prostate biopsy efficiency, and if percentages of infrastaging, subgrading and prediction of insignificant PCa are in accordance with the literature. At 3 years, we reproduced the results of the longest series of AS, so we have ascertained that our AS protocol can be implemented with increasingly more patients.

Efficient quantum algorithm for computing n-time correlation functions

We propose a method for computing n-time correlation functions of arbitrary spinorial, fermionic, and bosonic operators, consisting of an efficient quantum algorithm that encodes these correlations in an initially added ancillary qubit for probe and control tasks. For spinorial and fermionic systems, the reconstruction of arbitrary n-time correlation functions requires the measurement of two ancilla observables, while for bosonic variables time derivatives of the same observables are needed. Finally, we provide examples applicable to different quantum platforms in the frame of the linear response theory.

Optimizing prostate cancer screening; prospective randomized controlled study of the role of PSA and PCA3 testing in a sequential manner in an opportunistic screening program

OBJECTIVES

To reduce unnecessary biopsies (Bx) in an opportunistic screening programme of prostate cancer.

MATERIAL AND METHODS

We perform a prospective evaluation of PCA3 as a second line biomarker in an opportunistic screening for prostate cancer (PCa). From September-2010 until September-2012, 2,366 men, aged 40-74 years and with >10 years life expectancy, were initially screened with PSA/digital rectal examination (DRE). Men with previous Bx or with recent urine infections were excluded. Men with abnormal DRE and/or PSA >3 ng/ml were submitted for PCA3. All men with PCA3 ≥ 35 underwent an initial biopsy (IBx) -12cores-. Men with PCA3 < 35 were randomized 1:1 to either IBx or observation. Re-biopsy(16-18 cores) criteria were PSA increase >.5 ng/ml at 4-6 months or PSAv > .75 ng/ml/year.

RESULTS

With median follow-up (FU) of 10.1 months, PCA3 was performed in 321/2366 men (13.57%), 289 at first visit and 32 during FU. All 110 PCA3+ men (34.3%) were biopsied and PCa was identified in 43 men in IBx (39.1%). In the randomized arm, 110 were observed and 101 underwent biopsy, finding 12 PCa (11.9%), showing a statistically significant reduction of PCa detection rate in this cohort (P<.001). Global PCa detection rates were 40.9% and 9.5% for the PCA3+ and PCA3- branches, respectively (P<.001). Area under the curve for PSA and PCA3 were .601 and .74, respectively. This is an ongoing prospective study limited by its short follow-up period and still limited enrolment.

CONCLUSIONS

PCA3 as a second line biomarker within an opportunistic dual screening protocol, can potentially avoid 65.7% and 50.1% biopsies at first round and at median FU of 10.1 months, respectively, just missing around 3.2% of high grade PCa.

From transistor to trapped-ion computers for quantum chemistry

Over the last few decades, quantum chemistry has progressed through the development of computational methods based on modern digital computers. However, these methods can hardly fulfill the exponentially-growing resource requirements when applied to large quantum systems. As pointed out by Feynman, this restriction is intrinsic to all computational models based on classical physics. Recently, the rapid advancement of trapped-ion technologies has opened new possibilities for quantum control and quantum simulations. Here, we present an efficient toolkit that exploits both the internal and motional degrees of freedom of trapped ions for solving problems in quantum chemistry, including molecular electronic structure, molecular dynamics, and vibronic coupling. We focus on applications that go beyond the capacity of classical computers, but may be realizable on state-of-the-art trapped-ion systems. These results allow us to envision a new paradigm of quantum chemistry that shifts from the current transistor to a near-future trapped-ion-based technology.

Radical prostatectomy is a reasonable treatment for patients over 70 years of age

OBJECTIVE

To compare the tumor nature and oncological course of patients operated on by radical prostatectomy in three age groups.

MATERIAL AND METHOD

From the prospective completion of the data base of our department, we analyzed 1012 patients operated on between 1986 and December 2009. Patients with neo- or adjuvant treatment and those with pre-operative PSA over 50 were excluded. The sample was divided into three groups: younger than 60, 60 to 69 and over 70. The clinical, pathological variables, biochemical course and need for rescue treatment were analyzed. We consider biochemical relapse as when the PSA values reached values greater than 0.4 in two consecutive measurements. Rescue was defined as the need for hormone treatment or radiotherapy. We then made a comparative study, a univariate survival analysis by Kaplan and Meyer Curves and multivariate by Cox's regression.

RESULTS

The median follow-up was 55.1 months. Of the 1012 patients included in the study, 317 patients (31.3%) had biochemical progression and 259 (25.6%) required rescue treatment. We observed that the groups with the older age had a significantly higher PSA and higher stages than the rest. No differences were observed in the Gleason score of the surgical specimen or in the state of the surgical margins. Biochemical relapse free survival at 5 years was 72.3% (CI 66.4-78.2) in patients under 60 years, 65.3% (CI 60.6-70.0) for patients under 70 and 62.2% (CI 53.2-71.1) for patients of 70 years or older; P<.05. In the univariate study, age was a factor that was significantly associated to biochemical relapse. However, it loses interest in the multivariate study and PSA, pathological state and Gleason score regain interest. Rescue treatment free survival did not differ by age groups.

CONCLUSIONS

In the current study, worse biochemical evolution of patients over 70 was observed. However, this worse biochemical course was conditioned by clinically more aggressive tumors that, in our opinion, justifies the decision made in regards to the surgical approach taken with these patients.

Embedding quantum simulators for quantum computation of entanglement

We introduce the concept of embedding quantum simulators, a paradigm allowing the efficient quantum computation of a class of bipartite and multipartite entanglement monotones. It consists in the suitable encoding of a simulated quantum dynamics in the enlarged Hilbert space of an embedding quantum simulator. In this manner, entanglement monotones are conveniently mapped onto physical observables, overcoming the necessity of full tomography and reducing drastically the experimental requirements. Furthermore, this method is directly applicable to pure states and, assisted by classical algorithms, to the mixed-state case. Finally, we expect that the proposed embedding framework paves the way for a general theory of enhanced one-to-one quantum simulators.

Quantum simulation of noncausal kinematic transformations

We propose the implementation of Galileo group symmetry operations or, in general, linear coordinate transformations in a quantum simulator. With an appropriate encoding, unitary gates applied to our quantum system give rise to Galilean boosts or spatial and time parity operations in the simulated dynamics. This framework provides us with a flexible toolbox that enhances the versatility of quantum simulation theory, allowing the direct access to dynamical quantities that would otherwise require full tomography. Furthermore, this method enables the study of noncausal kinematics and phenomena beyond special relativity in a quantum controllable system.