Low-loss polarization control in fiber systems for quantum computation.

Optical quantum information processing requires low loss interference of quantum light. Also, when the interferometer is composed of optical fibers, degradation of interference visibility due to the finite polarization extinction ratio becomes a problem. Here we propose a low loss method to optimize interference visibility by controlling the polarizations to a crosspoint of two circular trajectories on the Poincaré sphere. Our method maximizes visibility with low optical loss by using fiber stretchers as polarization controllers on both paths of the interferometer. We also experimentally demonstrate our method, where the visibility was maintained basically above 99.9% for three hours using fiber stretchers with an optical loss of 0.02 dB (0.5%). Our method makes fiber systems promising for practical fault-tolerant optical quantum computers.

Generation of highly pure single-photon state at telecommunication wavelength.

Telecommunication wavelength with well-developed optical communication technologies and low losses in the waveguide are advantageous for quantum applications. However, an experimental generation of non-classical states called non-Gaussian states at the telecommunication wavelength is still underdeveloped. Here, we generate highly-pure-single-photon states, one of the most primitive non-Gaussian states, by using a heralding scheme with an optical parametric oscillator and a superconducting nano-strip photon detector. The Wigner negativity, the indicator of non-classicality, of the generated single photon state is -0.228 ± 0.004, corresponded to 85.1 ± 0.7% of single photon and the best record of the minimum value at all wavelengths. The quantum-optics-technology we establish can be easily applied to the generation of various types of quantum states, opening up the possibility of continuous-variable-quantum-information processing at the telecommunication wavelength.

Generation of Schrödinger cat states with Wigner negativity using a continuous-wave low-loss waveguide optical parametric amplifier.

Continuous-wave (CW) squeezed light is used in the generation of various optical quantum states, and thus is a fundamental resource of fault-tolerant universal quantum computation using optical continuous variables. To realize a practical quantum computer, a waveguide optical parametric amplifier (OPA) is an attractive CW squeezed light source in terms of its THz-order bandwidth and suitability for modularization. The usages of a waveguide OPA in quantum applications thus far, however, are limited due to the difficulty of the generation of the squeezed light with a high purity. In this paper, we report the first observation of Wigner negativity of the states generated by a heralding method using a waveguide OPA. We generate Schrödinger cat states at the wavelength of 1545 nm with Wigner negativity using a quasi-single-mode ZnO-doped periodically poled LiNbO3 waveguide module we developed. Wigner negativity is regarded as an important indicator of the usefulness of the quantum states as it is essential in the fault-tolerant universal quantum computation. Our result shows that our waveguide OPA can be used in wide range of quantum applications leading to a THz-clock optical quantum computer.

Efficient Backcasting Search for Optical Quantum State Synthesis.

Non-Gaussian states are essential for many optical quantum technologies. The so-called optical quantum state synthesizer (OQSS), consisting of Gaussian input states, linear optics, and photon-number resolving detectors, is a promising method for non-Gaussian state preparation. However, an inevitable and crucial problem is the complexity of the numerical simulation of the state preparation on a classical computer. This problem makes it very challenging to generate important non-Gaussian states required for advanced quantum information processing. Thus, an efficient method to design OQSS circuits is highly desirable. To circumvent the problem, we offer a scheme employing a backcasting approach, where the circuit of OQSS is divided into some sublayers, and we simulate the OQSS backwards from final to first layers. Moreover, our results show that the detected photon number by each detector is at most 2, which can significantly reduce the requirements for the photon-number resolving detector. By virtue of the potential for the preparation of a wide variety of non-Gaussian states, the proposed OQSS can be a key ingredient in general optical quantum information processing.

Laparoscopic isolated liver segmentectomy 8 for malignant tumors: techniques and comparison of surgical results with the open approach using a propensity score-matched study.

PURPOSE: Anatomic isolated liver segmentectomy 8 (ILSeg8) for malignancies remains technically challenging. The feasibility, safety, and oncologic validity of laparoscopic ILSeg8 are undefined, and thus were evaluated in comparison with the open approach. METHODS: This study enrolled 35 open and 29 laparoscopic ILSeg8 cases of hepatocellular carcinoma (n = 47), metastatic liver tumors (n = 16), and intrahepatic cholangiocarcinoma (n = 1) at our institution. The surgical techniques were based on the pre-hepatectomy extrahepatic Glissonian pedicle control, followed by cranial-to-caudal parenchymal dissection from the hepatic vein root side. The short- and long-term outcomes after ILSeg8 were retrospectively evaluated and compared between the open and laparoscopic approaches using 1:1 propensity score matching (PSM). RESULTS: Both before and after PSM, the laparoscopic ILSeg8 group had significantly less blood loss, lower postoperative serum bilirubin level, and a shorter postoperative hospital stay than the open group. The overall survival rates were comparable between the laparoscopic and open groups before (P = 0.017) and after (P = 0.043) PSM, with the similar recurrence-free survival rates between the groups. In a multivariable analysis of the cohort before PSM (n = 64), the laparoscopic approach was identified to be an independent factor for favorable overall survival (hazard ratio = 0.20, P = 0.039). CONCLUSION: Laparoscopic ILSeg8 using the extrahepatic Glissonian approach and hepatic vein root at first parenchymal dissection was feasible, safe, and oncologically acceptable. In ILSeg8 for malignancy, the laparoscopic approach potentially confers short-term advantages over the open approach with comparable long-term outcomes in select patients.

The impact of chronic Epstein-Barr virus infection on the liver graft of pediatric liver transplant recipients: A retrospective observational study.

BACKGROUND: Chronic high Epstein-Barr virus loads (CHEBV) are commonly observed in pediatric liver transplant patients. However, it is unclear how CHEBV impacts the liver graft. The aim of this study was to clarify the clinical and pathological impacts of CHEBV on the liver graft. METHODS: From 2012 to 2020, we retrospectively investigated 46 pediatric liver transplant patients (under 16 years) who survived ≥6 months. The patients were divided into two groups: CHEBV group (EBV DNA >10 000 IU/ml of whole blood for ≥6 months) and nonchronic high EBV (NCHEBV) group (patients who did not meet CHEBV criteria). Tacrolimus was reduced to <3.0 ng/ml in patients with EBV DNA >5000 IU/ml. Blood biochemistry data and pathological findings, obtained at the time of protocol and episodic biopsies, were compared between the two groups. RESULTS: Out of 46 patients, 28 CHEBV and 18 NCHEBV patients were enrolled. The blood biochemical examination did not show a significant difference between the two groups. In addition, no significant differences between the two groups were found in the pathological findings, including frequency of late acute rejection and the progression of fibrosis at the time of both protocol and episodic biopsies. Appropriate adjustment of immunosuppression for CHEBV management may have contributed to the prevention of the progression of fibrosis. CONCLUSION: CHEBV had little adverse effect on the liver graft. Graft fibrosis might have been avoided through optimal dose modification of tacrolimus. Further long-term monitoring is necessary because CHEBV may affect the pediatric liver graft in the long term.

Phase Locking between Two All-Optical Quantum Memories.

Optical approaches to quantum computation require the creation of multimode photonic quantum states in a controlled fashion. Here we experimentally demonstrate phase locking of two all-optical quantum memories, based on a concatenated cavity system with phase reference beams, for the time-controlled release of two-mode entangled single-photon states. The release time for each mode can be independently determined. The generated states are characterized by two-mode optical homodyne tomography. Entanglement and nonclassicality are preserved for release-time differences up to 400 ns, confirmed by logarithmic negativities and Wigner-function negativities, respectively.

All-Optical Storage of Phase-Sensitive Quantum States of Light.

We experimentally demonstrate storage and on-demand release of phase-sensitive, photon-number superposition states of the form α|0⟩+ße^{iθ}|1⟩ for an optical quantized oscillator mode. For this purpose, we newly developed a phase-probing mechanism compatible with a storage system composed of two concatenated optical cavities, which was previously employed for storage of phase-insensitive single-photon states [Phys. Rev. X 3, 041028 (2013)PRXHAE2160-330810.1103/PhysRevX.3.041028]. This is the first demonstration of all-optically storing highly nonclassical and phase-sensitive quantum states of light. The strong nonclassicality of the states after storage becomes manifest as a negative region in the corresponding Wigner function shifted away from the origin in phase space. This negativity is otherwise, without the phase information of the memory system, unobtainable. While our scheme includes the possibility of optical storage, on-demand release and synchronization of arbitrary single-rail qubit states, it is not limited to such states. In fact, our technique is extendible to more general phase-sensitive states such as multiphoton superposition or entangled states, and thus it represents a significant step toward advanced optical quantum information processing, where highly nonclassical states are utilized as resources.

Impact of Donor Age on Recipient Survival in Adult-to-Adult Living-donor Liver Transplantation.

OBJECTIVE: To investigate the influence of donor age on recipient outcome after living-donor partial liver transplantation (LDLT). BACKGROUND: Donor age is a well-known prognostic factor in deceased donor liver transplantation; however, its role in LDLT remains unclear. METHODS: We retrospectively analyzed 315 consecutive cases of primary adult-to-adult LDLT in our center between April 2006 and March 2014. Recipients were divided into 5 groups according to the donor age: D-20s (n = 60); D-30s (n = 72); D-40s (n = 57); D-50s (n = 94); and D-60s (n = 32). The recipient survival and the association with various clinical factors were investigated. RESULTS: Recipient survival proportions were significantly higher in D-20s compared with all the other groups (P = 0.008, < 0.001, < 0.001, and = 0.006, vs D-30s, -40s, -50s, and -60s, respectively), whereas there was no association between recipient survival and their own age. There are 3 typical relationships between donors and recipients in adult-to-adult LDLT: from child-to-parent, between spouses/siblings, and from parent-to-child. The overall survival in child-to-parent was significantly higher than in spouses/siblings (P = 0.002) and in parent-to-child (P = 0.005), despite significantly higher recipient age in child-to-parent [59 (42-69) years, P < 0.001]. Contrastingly, parent-to-child exhibited the lowest survival, despite the youngest recipient age [26 (20-43) years, P < 0.001]. In addition, younger donor age exhibited significantly better recipient survival both in hepatitis C virus-related and in non-hepatitis C virus diseases. Univariate and multivariate analyses both demonstrated that donor age and graft-type (right-sided livers) are independent prognostic factors for recipient survival. CONCLUSIONS: Donor age is an independent, strong prognostic factor in adult-to-adult LDLT.

Hydrogen Flush After Cold Storage as a New End-Ischemic Ex Vivo Treatment for Liver Grafts Against Ischemia/Reperfusion Injury.

Cold storage (CS) remains the gold standard for organ preservation worldwide, although it is inevitably associated with ischemia/reperfusion injury (IRI). Molecular hydrogen (H2 ) is well known to have antioxidative properties. However, its unfavorable features, ie, inflammability, low solubility, and high tissue/substance permeability, have hampered its clinical application. To overcome such obstacles, we developed a novel reconditioning method for donor organs named hydrogen flush after cold storage (HyFACS), which is just an end-ischemic H2 flush directly to donor organs ex vivo, and, herein, we report its therapeutic impact against hepatic IRI. Whole liver grafts were retrieved from Wistar rats. After 24-hour CS in UW solution, livers were cold-flushed with H2 solution (1.0 ppm) via the portal vein (PV), the hepatic artery (HA), or both (PV + HA). Functional integrity and morphological damages were then evaluated by 2-hour oxygenated reperfusion at 37°C. HyFACS significantly lowered portal venous pressure, transaminase, and high mobility group box protein 1 release compared with vehicle-treated controls (P < 0.01). Hyaluronic acid clearance was significantly higher in the HyFACS-PV and -PV + HA groups when compared with the others (P < 0.01), demonstrating the efficacy of the PV route to maintain the sinusoidal endothelia. In contrast, bile production and lactate dehydrogenase leakage therein were both significantly improved in HyFACS-HA and -PV + HA (P < 0.01), representing the superiority of the arterial route to attenuate biliary damage. Electron microscopy consistently revealed that sinusoidal ultrastructures were well maintained by portal HyFACS, while microvilli in bile canaliculi were well preserved by arterial flush. As an underlying mechanism, HyFACS significantly lowered oxidative damages, thus improving the glutathione/glutathione disulfide ratio in liver tissue. In conclusion, HyFACS significantly protected liver grafts from IRI by ameliorating oxidative damage upon reperfusion in the characteristic manner with its route of administration. Given its safety, simplicity, and cost-effectiveness, end-ischemic HyFACS may be a novel pretransplant conditioning for cold-stored donor organs.

Generation of a Cat State in an Optical Sideband.

We propose a method to subtract a photon from a double sideband mode of continuous-wave light. The central idea is to use phase modulation as a frequency sideband beam splitter in the heralding photon subtraction scheme, where a small portion of the sideband mode is down-converted to 0 Hz to provide a trigger photon. An optical cat state is created by applying the proposed method to a squeezed state at 500 MHz sideband, which is generated by an optical parametric oscillator. The Wigner function of the cat state reconstructed from a direct homodyne measurement of the 500 MHz sideband modes shows the negativity of W(0,0)=-0.088±0.001 without any loss corrections.

High-sensitive cardiac troponin T as a novel predictor for recurrence of atrial fibrillation after radiofrequency catheter ablation.

AIMS: We aimed to determine whether elevated serum high-sensitive cardiac troponin T (hs-TnT) levels predict atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI). METHODS AND RESULTS: We included 125 consecutive patients with AF (paroxysmal, n = 79; persistent, n = 46) who underwent first-time PVI. Serum hs-TnT, high-sensitive C-reactive protein (hs-CRP), atrial natriuretic peptide, and plasma B-type natriuretic peptide levels were measured in venous samples collected before PVI. Elevated hs-TnT was diagnosed in patients with levels ≥0.014 µg/L. All patients underwent multidetector computed tomographic examinations before PVI to measure left atrial volume (LAV) and left ventricular (LV) mass, which were indexed to body surface area. Arrhythmia recurrence was defined as AF/atrial tachycardia episodes lasting for ≥30 s after a 2-month blanking period from the PVI procedure. Elevated hs-TnT levels were observed in 22 (17.6%) patients. Age, diabetes mellitus, LV mass index, estimated glomerular filtration rate, and hs-CRP were independently associated with serum hs-TnT levels (all P < 0.05). During a mean follow-up of 12.9 ± 8.5 months after a single PVI procedure, the clinical recurrence rate was 33% (n = 41). Multivariate Cox proportional hazard analysis revealed that a greater LAV index (P = 0.01) and elevated serum hs-TnT level (P = 0.01) were significant predictors of AF recurrence after PVI. CONCLUSION: This study demonstrated that elevated serum hs-TnT levels are associated with AF recurrence independent of traditional risk factors and left atrial enlargement.

Coronary plaque rupture with subsequent thrombosis typifies the culprit lesion of non-ST-segment-elevation myocardial infarction, not unstable angina: non-ST-segment-elevation acute coronary syndrome study.

Recently, unstable angina pectoris (UAP) and non-ST-segment-elevation myocardial infarction (NSTEMI) have been considered together because they exhibit indistinguishable clinical and electrocardiogram features, and constitute non-ST-segment-elevation acute coronary syndrome (NSTE-ACS). However, no optical coherence tomography (OCT) studies have reported the association between vulnerable plaque morphology and clinical characteristics in NSTE-ACS patients based on assessment of clinical symptoms and myocardial necrosis. The aim of this study was to investigate the differences in clinical characteristics and plaque morphology assessed by OCT between patients with UAP and NSTEMI. Preinterventional OCT images of 84 NSTE-ACS patients were studied, 19 with NSTEMI and 65 with UAP, according to levels of high-sensitivity troponin T. The frequency of plaque rupture and thrombus in patients with NSTEMI was higher than in UAP patients with either class I or II + III (rupture: NSTEMI, 68 %; UAP classes II + III, 30 %; UAP class I, 19 %, thrombus: NSTEMI, 73 %; UAP classes II + III, 22 %; UAP class I, 14 %). In NSTEMI patients, the frequency of occurrence of both thrombus and rupture was the highest. Conversely, patients with UAP class I or those with UAP classes II + III most frequently had no thrombus and rupture, and the frequencies of the presence of thrombus were only 14 and 22 %, respectively. Multivariate analysis revealed that thrombus and plaque rupture were independently associated with NSTEMI. This study demonstrates that the morphological features of culprit lesions could be related to clinical severity in NSTE-ACS patients.

[The Role of Laboratory Medicine in Hematopoietic Stem Cell Transplantation "Echocardiogram"].

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a curative therapy for hematologic ma- lignancies. However, there are some potentially fatal complications, including graft-versus-host disease or infections, and transplant-related mortality is still high. One of the life-threatening complications related to allo-HSCT is cardiotoxicity. There are several causes of cardiotoxicity, such as pre-transplant chemothera- py, conditioning chemotherapy, cytokine storms due to sepsis or allogeneic immune reactions, rapid altera- tion of body fluid, and ischemic heart disease caused by transplant-associated thrombotic microangiopathy or calcineurin inhibitors. Echocardiography is a very useful and convenient method when assessing the cardiac function in daily clin- ics. The ejection fraction is a useful surrogate marker of the cardiac systolic function, and the trans-mitral valve inflow pattern is a useful surrogate marker of the cardiac diastolic function. There are several causes of cardiotoxicity during the course of allo-HSCT. In the pre-phase of allo-HSCT, the cumulative dose of anthracycline before transplantation is correlated with the rate of cardiac complications. In the acute phase of allo-HSCT, we should bear in mind cyclophosphamide-induced cardiotoxicity. Since these cardiotoxicities sometimes cannot be detected in the cardiac systolic function but can in the diastolic one, we should evaluate the cardiac diastolic function such as trans-mitral valve inflow pattern with echocar- diograms. In addition, some types of conditioning chemotherapies could have significant impacts on cardiac functions even in the chronic phase of allo-HSCT. In conclusion, it is very important to assess cardiac systolic and diastolic functions using echocardiograms for the improved management of cardiotoxicity in allo-HSCT recipients. [Review].

[A Case of Malignant Lymphoma of the Jejunum That Developed Stenosis and Perforation after a Complete Response to Chemotherapy].

A 57-year-old woman was admitted owing to epigastric pain.Abdominal computed tomography demonstrated a tumor in the origin of the jejunum.After an endoscopic biopsy, we diagnosed diffuse large B-cell lymphoma.We treated her with CHOP chemotherapy because pancreaticoduodenectomy is highly invasive.After 1 course of chemotherapy, the tumor was reduced.However, she developed a jejunal stenosis; therefore, we performed laparoscopic gastrojejunostomy.Furthermore, she developed perforated peritonitis on the sixth day after the surgery, and therefore, an emergency partial jejunum resection was performed.Histopathologically, viable lymphoma cells were not found in the resected intestine.She had a complete response 10 months after the surgery.Chemotherapy may cause intestinal stenosis and perforation requiring surgery; therefore, decisions about surgical procedures must be made carefully.

Creation and measurement of broadband squeezed vacuum from a ring optical parametric oscillator.

We report a 65 MHz-bandwidth triangular-shaped optical parametric oscillator (OPO) for squeezed vacuum generation at 860 nm. The triangle structure of our OPO enables the round-trip length to reach 45 mm as a ring cavity, which provides a counter circulating optical path available for introducing a probe beam or generating another squeezed vacuum. Hence our OPO is suitable for the applications in high-speed quantum information processing where two or more squeezed vacua form a complicated interferometer, like continuous-variable quantum teleportation. With a homemade, broadband and low-loss homodyne detector, a direct measurement shows 8.4 dB of squeezing at 3 MHz and also 2.4 dB of squeezing at 100 MHz.

Real-Time Quadrature Measurement of a Single-Photon Wave Packet with Continuous Temporal-Mode Matching.

Real-time controls based on quantum measurements are powerful tools for various quantum protocols. However, their experimental realization has been limited by mode mismatch between the temporal mode of quadrature measurement and that heralded by photon detection. Here, we demonstrate real-time quadrature measurement of a single-photon wave packet induced by photon detection by utilizing continuous temporal-mode matching between homodyne detection and an exponentially rising temporal mode. Single photons in exponentially rising modes are also expected to be useful resources for interactions with other quantum systems.

Epicardial Adipose Tissue Accumulation Is Associated With Renal Dysfunction and Coronary Plaque Morphology on Multidetector Computed Tomography.

BACKGROUND: Chronic kidney disease (CKD) is strongly associated with coronary artery disease (CAD), although the underlying pathophysiological mechanism remains unclear. Epicardial adipose tissue (EAT) has recently been recognized as an important source of various pro-inflammatory cytokines causing coronary atherosclerosis. This study investigated the relationship between CKD and EAT volume in association with high-risk plaque. METHODS AND RESULTS: The study included 275 patients with an estimated glomerular filtration rate (eGFR) ≥30 ml/min/1.73 m(2)who underwent multidetector computed tomography (MDCT) for the evaluation of CAD. Patients were classified, according to eGFR, into a CKD group (30≤eGFR<60 ml/min/1.73 m(2)) or a non-CKD group (eGFR ≥60 ml/min/1.73 m(2)). MDCT was used to assess coronary plaque morphology and EAT volume. One hundred and ten patients with CKD were more likely to be older, have higher prevalence of hypertension, lower serum HDL-C, higher serum CRP, and larger EAT volume, than those without CKD (all P<0.01). On multivariate analysis age, hypertension, and EAT volume were significantly associated with eGFR (all P<0.01). EAT volume was associated with the presence of high-risk plaque, independent of traditional CAD risk factors (P=0.003). CONCLUSIONS: Patients with CKD had significantly increased EAT volume, which could be associated with the presence of high-risk plaque.

Effect of Diuretic or Calcium-Channel Blocker Plus Angiotensin-Receptor Blocker on Diastolic Function in Hypertensive Patients.

BACKGROUND: Hypertension increases the risk of left ventricular (LV) diastolic dysfunction, and anti-hypertensive therapy may improve LV relaxation. The aim of this study was to investigate whether combining an angiotensin-receptor blocker (ARB) with either hydrochlorothiazide (HCTZ) or a calcium-channel blocker (CCB) improves LV relaxation in patients with hypertension and diastolic dysfunction. METHODS AND RESULTS: Hypertensive patients who had not achieved their target blood pressure with at least 4 weeks of ARB therapy were randomly assigned to receive either a fixed-dose combination of losartan and HCTZ (losartan/HCTZ; n=110) or a combination of amlodipine and a typical ARB dosage (CCB/ARB; n=121) and followed for 24 weeks. The primary endpoint was change in early diastolic mitral annular velocity (e', cm/s). Systolic blood pressure decreased in both groups after switch to the combination therapies. E' velocity increased both in the losartan/HCTZ (0.52 cm/s) and in the CCB/ARB (0.59 cm/s) groups. The mean (95% CI) treatment difference was -0.02 (-0.37 to 0.34) cm/s, indicating that improvement in LV relaxation was similar between the groups. The ratio of early mitral inflow velocity to e' velocity and left atrial volume index were significantly decreased in the losartan/HCTZ group. CONCLUSIONS: The combination of losartan and HCTZ is as effective as amlodipine plus ARB in improving LV relaxation in hypertensive patients.