Experimental Shot-by-Shot Estimation of Quantum Measurement Confidence.

We demonstrate the single-shot confidence estimation for individual quantum measurement outcomes using the continuous measurement theory of the quantum counting process applied to the quantum state identification problem. We experimentally obtain single-shot and average confidences for quantum measurements and show that they favorably compare to that of the idealized classical measurement. Finally, we demonstrate that single-shot confidence estimations correctly represent observed experimental outcomes for a large ensemble of measurements.

A post-processing-free single-photon random number generator with ultra-low latency.

The low-latency requirements of a practical loophole-free Bell test preclude time-consuming post-processing steps that are often used to improve the statistical quality of a physical random number generator (RNG). Here we demonstrate a post-processing-free RNG that produces a random bit within 2.4(2) ns of an input trigger. We use weak feedback to eliminate long-term drift, resulting in 24 hour operation with output that is statistically indistinguishable from a Bernoulli process. We quantify the impact of the feedback on the predictability of the output as less than 6.4×10-7 and demonstrate the utility of the Allan variance as a tool for characterizing non-idealities in RNGs.

Simple autocorrelation method for thoroughly characterizing single-photon detectors.

We introduce and demonstrate a simple and highly sensitive method for characterizing single-photon detectors. This method is based on analyzing multi-order correlations among time-tagged detection events from a device under calibrated continuous-wave illumination. First- and second-order properties such as detection efficiency, dark count rate, afterpulse probability, dead time, and reset behavior are measured with high accuracy from a single data set, as well as higher-order properties such as higher-order afterpulse effects. While the technique is applicable to any type of click/no-click detector, we apply it to two different single-photon avalanche diodes, and we find that it reveals a heretofore unreported afterpulse effect due to detection events that occur during the device reset.

Strong Loophole-Free Test of Local Realism.

We present a loophole-free violation of local realism using entangled photon pairs. We ensure that all relevant events in our Bell test are spacelike separated by placing the parties far enough apart and by using fast random number generators and high-speed polarization measurements. A high-quality polarization-entangled source of photons, combined with high-efficiency, low-noise, single-photon detectors, allows us to make measurements without requiring any fair-sampling assumptions. Using a hypothesis test, we compute p values as small as 5.9×10^{-9} for our Bell violation while maintaining the spacelike separation of our events. We estimate the degree to which a local realistic system could predict our measurement choices. Accounting for this predictability, our smallest adjusted p value is 2.3×10^{-7}. We therefore reject the hypothesis that local realism governs our experiment.

What is the incidence of biliary carcinoma in choledochal cysts, when do they develop, and how should it affect management?

The incidence of cancer in choledochal cysts (CCs) in adults was calculated to determine the timing and need for surgery. In 78 publications (1996-2010), 434 of 5780 reported CCs patients had cancer. Cholangiocarcinoma (70.4 %) and gallbladder cancer (23.5 %) were the most common malignancies. Only nine malignancies were reported before age 18 (0.42 %). In contrast, the incidence of malignancy in adults was 11.4 %. The median age for diagnosis of cancer was 42 years, and the incidence increased with each decade.

Three synchronous, sporadic and separate periampullary and pancreatic tumors: more than a coincidence?

Three sporadic, synchronous, and separate lesions in the ampulla of Vater and the head of the pancreas presented in an 81-year-old male. One was symptomatic and two were incidental. One was detected preoperatively (the ampullary lesion) and two by examination of the resected specimen (the neuroendocrine and pancreatic carcinomas). The case is summarized and the literature and the issue of commonality are reviewed.

Demonstration of particle tracking with scintillating fibres read out by a SPAD array sensor and application as a neutrino active target.

Scintillating fibre detectors combine sub-mm resolution particle tracking, precise measurements of the particle stopping power and sub-ns time resolution. Typically, fibres are read out with silicon photomultipliers (SiPM). Hence, if fibres with a few hundred µ m diameter are used, either they are grouped together and coupled with a single SiPM, losing spatial resolution, or a very large number of electronic channels is required. In this article we propose and provide a first demonstration of a novel configuration which allows each individual scintillating fibre to be read out regardless of the size of its diameter, by imaging them with Single-Photon Avalanche Diode (SPAD) array sensors. Differently from SiPMs, SPAD array sensors provide single-photon detection with single-pixel spatial resolution. In addition, O(us) or faster coincidence of detected photons allows to obtain noise-free images. Such a concept can be particularly advantageous if adopted as a neutrino active target, where scintillating fibres alternated along orthogonal directions can provide isotropic, high-resolution tracking in a dense material and reconstruct the kinematics of low-momentum protons (down to 150 MeV/c), crucial for an accurate characterisation of the neutrino-nucleus cross section. In this work the tracking capabilities of a bundle of scintillating fibres coupled to SwissSPAD2 is demonstrated. The impact of such detector configuration in GeV-neutrino experiments is studied with simulations and reported. Finally, future plans, including the development of a new SPAD array sensor optimised for neutrino detection, are discussed.

Robotic pancreatic surgery is no substitute for experience and clinical judgment: an initial experience and literature review.

Robotic pancreatic surgery offers technical advantages, and has been applied across many surgical specialties. We report an initial experience of 12 distal pancreatic resections for benign tumors from an established pancreatic center with previous general and biliary laparoscopic experience. Of a total of 12 patients, 7 were women; the mean age was 55.5 years, and the lesions included 8 distal intraductal papillary mucinous tumors, 1 insulinoma and in 3 a non-functioning neuroendocrine tumor. All operations were performed in between 90 and 180 minutes, and blood loss and hospital stay were minimal.

Pancreatic mucinous cystic neoplasm with sarcomatous stroma metastasizing to liver: a case report and review of literature.

We report a case of mucinous cystic neoplasm of pancreas with sarcomatous stroma metastasizing to the liver. The tumor occurred in a male patient aged 46 years. Symptoms included persistent epigastric and right upper quadrant pain. Radiographically, the pancreas contained four large cystic masses located in the neck, body, and tail. Histologically, the cysts were lined with benign, mucinous epithelium with underlying bland, storiform, ovarian-like stroma. An undifferentiated focally hyalinized, sarcomatous stroma composed of bland spindle cells showing short fascicular growth pattern and focal nuclear palisading was associated with the epithelial component in one of the cysts. These cells showed strong immunoreactivity with vimentin and inhibin (weak), they were negative for CD34, estrogen receptor, progesterone receptor, androgen, calretinin, S-100, CD117, melan A, chromogranin, and synaptophysin. A morphologically and immunohistochemically identical metastatic sarcomatous focus was identified in the liver without any glandular component. This case is unique in its clinically malignant behaviour and metastatic nature despite its morphologically benign epithelial and stromal components.

NIR Fluorescence lifetime macroscopic imaging with a novel time-gated SPAD camera.

SwissSPAD3 is the latest of a family of widefield time-gated SPAD imagers developed for fluorescence lifetime imaging (FLI) applications. Its distinctive features are (i) the ability to define shorter gates than its predecessors (width W < 1 ns), (ii) support for laser repetition rates up to at least 80 MHz and (iii) a dual-gate architecture providing an effective duty cycle of 100%. We present widefield macroscopic FLI measurements of short lifetime NIR dyes, analyzed using the phasor approach. The results are compared with those previously obtained with SwissSPAD2 and to theoretical predictions.

Massively parallel, real-time multispeckle diffuse correlation spectroscopy using a 500 × 500 SPAD camera.

Diffuse correlation spectroscopy (DCS) is a promising noninvasive technique for monitoring cerebral blood flow and measuring cortex functional activation tasks. Taking multiple parallel measurements has been shown to increase sensitivity, but is not easily scalable with discrete optical detectors. Here we show that with a large 500 × 500 SPAD array and an advanced FPGA design, we achieve an SNR gain of almost 500 over single-pixel mDCS performance. The system can also be reconfigured to sacrifice SNR to decrease correlation bin width, with 400 ns resolution being demonstrated over 8000 pixels.

Gas chromatograph calibration of gas mixtures using a versatile precision volumetric apparatus.

A compact, volumetric apparatus was developed for accurate automated preparation of standard gas and gas-liquid mixtures for gas chromatograph detector calibration, with accuracies comparable to those from gravimetric or Coriolis flow methods. The method developed by the principal author is not an adaptation or extension of any other apparatus or technology, and measurements involve only stepper motor steps, temperature, and pressure ratios. Mixture preparation is accomplished via the displacement of gas between chambers in a highly uniform cylinder, separated by a movable piston. Piston movement, with piston end rods of exactly equal diameter, ensures that there is no change in interior volume, and the volume of gas displaced from the bottom into the top compartment is exactly proportional to the piston travel measured to within 10 µm. The apparatus, operation, and previously unpublished measurements on common refinery gas mixtures over large concentration ranges are described in detail. These confirmed the accuracy and versatility of the apparatus and also the principle of no pressure change during mixture preparation, from sensitive pressure measurements. Conservative expanded uncertainties in prepared mixture mole fraction ranged from 0.001 to 0.002 over extended composition ranges. Absolute average deviations for the detector response factor for the mixtures ranged from 0.001 to 0.002. An exact new mathematical solution procedure permits the use of impure "pure" gases without loss of accuracy and can be applied to other procedures for standard gas mixture preparation. An exact expression is listed for determining "pure" gas purity.

Blueprint for safe transition from a low- to high-volume pancreatic surgery center.

We describe a straightforward model to implement a high volume specialty surgery program at a community hospital. Using pancreatic surgery as an example, we employed published processes in three arenas. First, mandatory multidisciplinary tumor board presentations captured all the patients considered for surgery. Then, perioperative protocols using tools such as enhanced recovery and teamwork in the perioperative arena created a reproducible and safe environment for complex surgery. We critically reviewed all complications using the Clavien-Dindo methodology, and confirmed our favorable outcomes via the targeted NSQIP program. These standard steps can be used for implementation of a new complex surgical procedure.

Hepatic actinomycosis mimicking an isolated tumor recurrence.

Actinomyces species has been described as an opportunistic pathogen, particularly in the oral cavity; however, in rare cases these bacteria can cause actinomycosis which is characterized by formation of abscesses in the mouth, lungs, or gastrointestinal tract. Actinomycosis was commonly present in the pre-antibiotic era; however, it has a low prevalence now days. It has been recognized since 150 years ago, but because of its variable clinical presentation and indolent course, its recognition is difficult and patients are often misdiagnosed. Here we present a case of primary hepatic actinomycosis presenting as a metastatic liver tumor.

Superior mesenteric artery originating from the celiac axis: a rare vascular anomaly.

The knowledge of the vascular anatomy of the concerned region is an important prerequisite for planning surgical intervention. The awareness of the existing vascular anomalies enhances the insight regarding that region. We report a patient undergoing preoperative evaluation with CTA finding of Superior Mesenteric Artery (SMA) originating from the celiac artery. This celiac-mesenteric trunk is rare (<1%).

Low-noise photon counting above 100 million counts per second with a high-efficiency reach-through single-photon avalanche diode system.

We demonstrate a method that allows a high-efficiency single-photon-avalanche diode (SPAD) with a thick absorption region (> 10 µm) to count single photons at rates significantly higher than previously demonstrated. We apply large (> 30 V) AC bias gates to the SPAD at 1 GHz and detect minute avalanches with a discrimination threshold of 5(1) mV by means of radio-frequency (RF) interferometry. We measure a reduction by a factor of ≈ 500 in the average charge per avalanche when compared to operation in its traditional active-quenching module, and a relative increase of >19 % in detection efficiency at 850 nm. The reduction in charge strongly suppresses self-heating effects in the diode that can degrade performance at high avalanche rates. We show that the single-photon detection system maintains high efficiency at count rates exceeding 108s-1.

Low-bias high-speed quantum random number generator via shaped optical pulses.

We present an optical quantum random number generator (QRNG) based on the digitized time interval between random photon arrivals. By tailoring the photon flux of the laser diode, the statistics of the waiting-time distribution are altered to approximate the ideal, uniform case. This greatly reduces the need for post-processing, and enables fast, secure quantum random number generation at rates exceeding 110 Mbit/s.

A colorimetric method for detection of K-ras codon 12 point mutations in DNA extracted from tissue and peripheral blood in pancreatic disorders.

Molecular-based methods to monitor point mutations require special and expensive equipment unavailable in most hospitals. Colorimetric-based analysis is an ideal platform for K-ras codon 12 gene point mutations because it uses commonly found hospital equipment. The colorimetric assay is sensitive and specific, detecting mutated DNA levels as low as 1% in a wild-type background. Paired genomic DNA extracts of fixed tissue and cellular fractions of peripheral blood are more sensitive and accurate than unpaired samplings. This approach has the potential to improve K-ras point mutation scans as well as to detect micrometastases in circulating tumor cells.

Preoperative evaluation and a risk assessment in patients undergoing abdominal surgery.

Patients who undergo abdominal surgery present along a variable spectrum of health. This ranges from the healthy young patient undergoing elective hemorrhoid surgery to the octogenarian in unstable health with multiple comorbidities. Regardless of a patient's current state of health, a preoperative assessment is crucial in planning the operative approach and in recognizing the possible postoperative complications for the implementation of a proper intervention if necessary. A broad evaluation of the patient includes identifying conditions that may predispose the patient to risks and the complications not directly related to the surgical procedure. The purpose of this article is to review the preoperative assessment in patients undergoing simple to complex procedures. The article provides general guidelines for the preoperative workup, which should be individualized for each patient, and the planned procedure, with the goal of reducing the postoperative complications. Risk stratification depends on a patient's condition and the extension of the planned surgical approach. It may also help to improve the postoperative outcome. A further preoperative workup should be individualized and tailored to the complexity of each case.

Central pancreatectomy without anastomosis.

BACKGROUND: Central pancreatectomy has a unique application for lesions in the neck of the pancreas. It preserves the distal pancreas and its endocrine functions. It also preserves the spleen. METHODS: This is a retrospective review of 10 patients who underwent central pancreatectomy without pancreatico-enteric anastomosis between October 2005 and May 2009. The surgical indications, operative outcomes, and pathologic findings were analyzed. RESULTS: All 10 lesions were in the neck of the pancreas and included: 2 branch intraductal papillary mucinous neoplasms (IPMNs), a mucinous cyst, a lymphoid cyst, 5 neuroendocrine tumors, and a clear cell adenoma. CONCLUSION: Central pancreatectomy without pancreatico-enteric anastomosis for lesions in the neck and proximal pancreas is a safe and effective procedure. Morbidity is low because there is no anastomosis. Long term endocrine and exocrine function has been maintained.