Computational version of the correlation light-field camera.

Light-field cameras allow the acquisition of both the spatial and angular components of the light-field. The conventional way to perform such acquisitions leads to a strong spatio-angular resolution limitation but correlation-enabled plenoptic cameras have been introduced recently that relax this constraint. Here we use a computational version of this concept to acquire realistic light-fields images using a commercial DSLR Camera lens as an imaging system. By placing the image sensor in the focal plane of a lens, within the camera we ensure the acquisition of pure angular components together with the spatial information. We perform an acquisition presenting a high spatio-angular rays resolution obtained through a trade off of the temporal resolution. The acquisition reported is photo-realistic and the acquisition of diffraction limited features is observed with the setup. Finally, we demonstrate the refocusing abilities of the camera.

Imaging Bell-type nonlocal behavior.

The violation of a Bell inequality not only attests to the nonclassical nature of a system but also holds a very unique status within the quantum world. The amount by which the inequality is violated often provides a good benchmark on how a quantum protocol will perform. Acquiring images of such a fundamental quantum effect is a demonstration that images can capture and exploit the essence of the quantum world. Here, we report an experiment demonstrating the violation of a Bell inequality within observed images. It is based on acquiring full-field coincidence images of a phase object probed by photons from an entangled pair source. The image exhibits a violation of a Bell inequality with S = 2.44 ± 0.04. This result both opens the way to new quantum imaging schemes based on the violation of a Bell inequality and suggests promise for quantum information schemes based on spatial variables.

Phase and amplitude imaging with quantum correlations through Fourier Ptychography.

Extracting as much information as possible about an object when probing with a limited number of photons is an important goal with applications from biology and security to metrology. Imaging with a few photons is a challenging task as the detector noise and stray light are then predominant, which precludes the use of conventional imaging methods. Quantum correlations between photon pairs has been exploited in a so called 'heralded imaging scheme' to eliminate this problem. However these implementations have so-far been limited to intensity imaging and the crucial phase information is lost in these methods. In this work, we propose a novel quantum-correlation enabled Fourier Ptychography technique, to capture high-resolution amplitude and phase images with a few photons. This is enabled by the heralding of single photons combined with Fourier ptychographic reconstruction. We provide experimental validation and discuss the advantages of our technique that include the possibility of reaching a higher signal to noise ratio and non-scanning Fourier Ptychographic acquisition.

Characteristics and clinical outcomes after treatment of a national cohort of PCR-positive Lyme arthritis.

OBJECTIVES: To describe the clinical and microbiological characteristics and outcomes after antibiotic treatment of a national cohort of patients with Lyme arthritis confirmed by PCR testing on synovial fluid and by serology, when available. METHODS: Using the French National Reference Center for Borrelia database, patients with a positive PCR on synovial fluid for Borrelia were identified. Patient clinical and biological characteristics were reviewed from patient records. Long-term outcomes after treatment were studied through a questionnaire and with follow-up data. RESULTS: Among 357 synovial fluid testing by PCR between 2010 and 2016, 37 (10.4%) were positive for Borrelia. Patients' median age was 36 years (range 6-78) with 61% of men and 28% patients under 18. The presentation was monoarticular in 92% and the knee was involved in 97%. Contrary to the Borrelia species repartition in European ticks, B. burgdorferi sensu stricto was the most prevalent species found in synovial fluid (54%) followed by B. azfelii (29%) and B. garinii (17%). Antibiotic treatments were mainly composed of doxycycline (n = 24), ceftriaxone (n = 10) and amoxicillin (n = 6), for a median duration of 4 weeks (range 3-12). Despite a properly conducted treatment, 34% of patients (n = 12) developed persistent synovitis for at least 2 months (median duration 3 months, range 2-16). Among those, 3 developed systemic inflammatory oligo- or polyarthritis in previously unaffected joints with no signs of persistent infection (repeated PCR testing negative), which mandated Disease-Modifying Antirheumatic Drugs (DMARD) introduction, leading to remission. CONCLUSION: In France and contrary to ticks ecology, Lyme arthritis is mainly caused by B. burgdorferi sensu stricto. Despite proper antibiotic therapy, roughly one third of patients may present persistent inflammatory synovitis and a small proportion may develop systemic arthritis. In such cases, complete remission can be reached using DMARD.

Experimental Limits of Ghost Diffraction: Popper's Thought Experiment.

Quantum ghost diffraction harnesses quantum correlations to record diffraction or interference features using photons that have never interacted with the diffractive element. By designing an optical system in which the diffraction pattern can be produced by double slits of variable width either through a conventional diffraction scheme or a ghost diffraction scheme, we can explore the transition between the case where ghost diffraction behaves as conventional diffraction and the case where it does not. For conventional diffraction the angular extent increases as the scale of the diffracting object is reduced. By contrast, we show that no matter how small the scale of the diffracting object, the angular extent of the ghost diffraction is limited (by the transverse extent of the spatial correlations between beams). Our study is an experimental realisation of Popper's thought experiment on the validity of the Copenhagen interpretation of quantum mechanics. We discuss the implication of our results in this context and explain that it is compatible with, but not proof of, the Copenhagen interpretation.

Resolution limits of quantum ghost imaging.

Quantum ghost imaging uses photon pairs produced from parametric downconversion to enable an alternative method of image acquisition. Information from either one of the photons does not yield an image, but an image can be obtained by harnessing the correlations between them. Here we present an examination of the resolution limits of such ghost imaging systems. In both conventional imaging and quantum ghost imaging the resolution of the image is limited by the point-spread function of the optics associated with the spatially resolving detector. However, whereas in conventional imaging systems the resolution is limited only by this point spread function, in ghost imaging we show that the resolution can be further degraded by reducing the strength of the spatial correlations inherent in the downconversion process.

Sub-shot-noise shadow sensing with quantum correlations.

The quantised nature of the electromagnetic field sets the classical limit to the sensitivity of position measurements. However, techniques based on the properties of quantum states can be exploited to accurately measure the relative displacement of a physical object beyond this classical limit. In this work, we use a simple scheme based on the split-detection of quantum correlations to measure the position of a shadow at the single-photon light level, with a precision that exceeds the shot-noise limit. This result is obtained by analysing the correlated signals of bi-photon pairs, created in parametric downconversion and detected by an electron multiplying CCD (EMCCD) camera employed as a split-detector. By comparing the measured statistics of spatially anticorrelated and uncorrelated photons we were able to observe a significant noise reduction corresponding to an improvement in position sensitivity of up to 17% (0.8dB). Our straightforward approach to sub-shot-noise position measurement is compatible with conventional shadow-sensing techniques based on the split-detection of light-fields, and yields an improvement that scales favourably with the detector's quantum efficiency.

Demonstrating an absolute quantum advantage in direct absorption measurement.

Engineering apparatus that harness quantum theory promises to offer practical advantages over current technology. A fundamentally more powerful prospect is that such quantum technologies could out-perform any future iteration of their classical counterparts, no matter how well the attributes of those classical strategies can be improved. Here, for optical direct absorption measurement, we experimentally demonstrate such an instance of an absolute advantage per photon probe that is exposed to the absorbative sample. We use correlated intensity measurements of spontaneous parametric downconversion using a commercially available air-cooled CCD, a new estimator for data analysis and a high heralding efficiency photon-pair source. We show this enables improvement in the precision of measurement, per photon probe, beyond what is achievable with an ideal coherent state (a perfect laser) detected with 100% efficient and noiseless detection. We see this absolute improvement for up to 50% absorption, with a maximum observed factor of improvement of 1.46. This equates to around 32% reduction in the total number of photons traversing an optical sample, compared to any future direct optical absorption measurement using classical light.

Long-term efficacy and safety of antitumour necrosis factor alpha treatment in rhupus: an open-label study of 15 patients.

BACKGROUND: The efficacy of antitumour necrosis factor alpha (anti-TNF-α) treatment is well recognised in rheumatoid arthritis (RA) but remains controversial in systemic lupus erythematosus (SLE). Therefore, the role of anti-TNF-α treatment in 'Rhupus', a disease sharing features of RA and SLE, is still debated. OBJECTIVE: To evaluate the efficacy and tolerance of anti-TNF-α in patients with rhupus. METHODS: Fifteen patients with rhupus with Disease Activity Score 28 (DAS 28) >3.2 despite conventional disease-modifying anti-rheumatic drugs were included in an open-label study. Patients were monitored at months (M) 3, 6, 12, 24 and 60 with SLE Disease Activity Index (SLEDAI) and DAS 28. Statistical analyses were performed using Bayesian methods and Prob >97.5% was considered significant. RESULTS: Twelve patients were treated with etanercept for a median duration of 62.5 (range: 6-112) months and three patients by adalimumab during 36.0 (range: 4-52) months. At baseline, median DAS 28 and SLEDAI were 5.94 (4.83-8.09) and 6 (4-8), respectively. DAS 28 and SLEDAI decreased significantly after 3 months, respectively, to 3.70 (1.80-6.42) and 4 (0-6) (Prob >99.9%, for both). These changes persisted at M6, M12, M24 and M60 (Prob >99.9%, for all). Median prednisone dose decreased significantly from 15 (5-35) mg/day to 5 (0-20) mg/day after 6 months and over the follow-up (Prob >99.9%, for all). Tolerance was acceptable, with a severe infection rate of 3.0 per 100 patient-years. CONCLUSION: This pilot study suggests that anti-TNF-α is effective in patients with rhupus with refractive arthritis and has an acceptable safety profile.

Einstein-Podolsky-Rosen paradox in single pairs of images.

Spatially entangled twin photons provide a test of the Einstein-Podolsky-Rosen (EPR) paradox in its original form of position (image plane) versus impulsion (Fourier plane). We show that recording a single pair of images in each plane is sufficient to safely demonstrate an EPR paradox. On each pair of images, we have retrieved the fluctuations by subtracting the fitted deterministic intensity shape and then have obtained an intercorrelation peak with a sufficient signal to noise ratio to safely distinguish this peak from random fluctuations. A 95% confidence interval has been determined, confirming a high degree of paradox whatever the considered single pairs. Last, we have verified that the value of the variance of the difference between twin images is always below the quantum (poissonian) limit, in order to ensure the particle character of the demonstration. Our demonstration shows that a single image pattern can reveal the quantum and non-local behavior of light.

Einstein-Podolsky-Rosen paradox in twin images.

Spatially entangled twin photons provide both promising resources for modern quantum information protocols, because of the high dimensionality of transverse entanglement, and a test of the Einstein-Podolsky-Rosen paradox in its original form of position versus impulsion. Usually, photons in temporal coincidence are selected and their positions recorded, resulting in a priori assumptions on their spatiotemporal behavior. In this Letter, we record, on two separate electron-multiplying charge coupled devices cameras, twin images of the entire flux of spontaneous down-conversion. This ensures a strict equivalence between the subsystems corresponding to the detection of either position (image or near-field plane) or momentum (Fourier or far-field plane). We report the highest degree of paradox ever reported and show that this degree corresponds to the number of independent degrees of freedom, or resolution cells, of the images.

Gemcitabine-induced myopathy.

BACKGROUND: There have been few studies on muscle injury caused by cytotoxic agents used in cancer. In particular, only four cases of muscle manifestations have been reported in patients who received gemcitabine as single chemotherapy without adjuvant radiotherapy. In only one of these observations gemcitabine was considered to be the causative agent. METHODS: We report the case of a patient without comorbidity treated with gemcitabine monotherapy for 2 months for pancreatic adenocarcinoma, who developed a proximal motor deficiency of the lower limbs and myolysis (creatinine kinase 1858 IU/L) associated with an erythema of both thighs. RESULTS: Muscle MRI revealed the presence of edema on both the quadriceps muscles. A muscle biopsy showed post-necrotic regeneration and significant vascular proliferation. Only three small inflammatory infiltrates were observed, while expression of the major histocompatibility complex class I in muscle fibers was normal. There was no recurrence of cancer, anti-TIF-1γ antibodies tested negative, and discontinuation of gemcitabine, without further treatment, resulted in complete disappearance of symptoms. CONCLUSIONS: The present observation suggests that gemcitabine monotherapy without adjuvant radiotherapy can cause myopathy through vascular lesions, a mechanism which also underlies the more common side effects of this treatment. These findings have obvious therapeutic implications.

Acute hepatitis E during biotherapy.

Hepatitis E is a rare and usually asymptomatic infection. However, its incidence is rising in France, and it can cause severe or chronic manifestations in immunocompromised patients. Here, we report a case of hepatitis E in a patient with rheumatoid arthritis who had immunosuppression due to treatment with a biological agent.

Second reported case of human infection with Streptococcus equi subsp. ruminatorum.

The field of zoonoses changes constantly. Streptococcus equi subsp. ruminatorum is a group C Streptococcus subspecies first identified in 2004. The first case of human infection with this agent was reported in 2007. Here, we report a second case. A 70-year-old man had acute spondylodiscitis and endocarditis involving the anterior mitral valve leaflet. S. equi subsp. ruminatorum was identified in the blood cultures. Antibiotic therapy was successful in eradicating the infection. The workup showed hypogammaglobulinemia with stage I myeloma. He reported frequent contacts with horses including two that exhibited symptoms of upper airway infection a few days before his symptoms started. Serological tests indicated S. equi infection in both animals. This unusual case confirms that S. equi subsp. ruminatorum can cause human disease. In addition, our patient was probably contaminated via the skin, a mode of transmission that has not been described previously. It also highlights the usefulness of molecular biology tests, which should be performed routinely in patients with group C streptococcus infections and evidence suggesting a zoonosis.

Malignant fibrous histiocytoma: a retrospective study of 109 cases.

The purpose of this report is to assess the prognostic factors that could influence management and clinical outcome of malignant fibrous histiocytoma (MFH) of soft tissues. Between 1975 and 1998, 109 patients diagnosed with MFH of the soft tissues, seen at King Faisal Specialist Hospital and Research Center, have been reviewed. Of the 109 patients, 75 were men and 34 were women. The median age at presentation was 48 years (range: 3-94). Seven patients (6%) had regional nodal disease and 10 other patients (9%) with distant metastases were excluded from survival analysis. The remaining 92 patients had localized disease and had surgery as the primary treatment modality with or without radiotherapy and/or chemotherapy. Extremities were the most common location (58%). Tumors less than 5 cm represented 32%, whereas 68% had tumors 5 cm or more. Low-grade tumors constituted 46%, and the remaining 54% were high grade. Thirty-seven percent of patients had positive surgical margins histologically after complete gross resection. The 5- and 10-year relapse-free survival (RFS) rates were 39% and 36%, respectively. Isolated local recurrence occurred in 20 patients (22%), isolated metastatic disease without local recurrence in 9 patients (10%), and combined local and metastatic disease occurred in 20 patients (22%). The overall 5- and 10-year overall survival (OS) rates were 50% and 43%, respectively. On multivariate analysis, tumor size and radiation dose were significant factors for RFS (p = 0.04 and 0.0005, respectively). In terms of OS, size, histologic grade, and surgical margins were significant factors on multivariate analysis (p = 0.001. 0.006, and 0.0001, respectively). Complete surgical resection at the time of primary tumor presentation is likely to afford the best chance for RFS and OS. Radiation therapy plays an important role, in combination with surgery for better local control, particularly in high-grade lesions, and in cases with positive surgical margins after wide complete gross excision. The role of adjuvant chemotherapy remains investigational.