First-order optical coherence of photonic-dimer coherent states.

Photon-photon correlations assume a pivotal significance in optical coherence. Recently, a new, to the best of our knowledge, type of quantum photonic states, the coherent state of photonic dimers, has been introduced, wherein the fundamental building blocks are two-photon bound states, instead of individual photons as in conventional lasers. In this Letter, we investigate the first-order coherence properties of the photonic-dimer coherent states, as well as the interference patterns in a double-slit interferometer setup, and compare with the coherence properties of other optical light sources, e.g., the conventional laser and the thermal light.

The impact of secondhand smoke on the development of kidney stone disease is not inferior to that of smoking: a longitudinal cohort study.

BACKGROUND: Tobacco use and secondhand smoke (SHS) are risk factors of kidney stone disease (KSD). The hypothesis is that tobacco produces chemicals that increase oxidative stress and vasopressin, which leads to decreased urine output, and contributes to stone formation. The aim of this study was to examine the effects of smoking and SHS on the development of KSD. MATERIALS AND METHODS: We analyzed a total of 25,256 volunteers with no history of KSD participated in the Taiwan Biobank. The presence of underlying and follow-up KSD was surveyed by a self-administrated questionnaire. They were classified into three groups on the basis of smoking and SHS exposure, accessed with survey questionnaires; never-smokers with no SHS exposure, never-smokers with SHS exposure and ever-smokers groups. RESULTS: KSD was noted in 352 (2.0%), 50 (3.3%) and 240 (4.1%) subjects in the never-smokers with no SHS exposure, never-smokers with SHS exposure and ever-smokers groups, respectively, with a mean follow-up of 4 years. The odds ratio (OR) of KSD was higher in the never-smokers with SHS exposure (OR, 1.622; 95% confidence interval [95% CI], 1.225 to 2.255) and ever-smokers groups (OR, 1.282; 95% CI, 1.044 to 1.574) than in the never-smokers with no SHS exposure group after adjustment of confounders. In addition, never-smokers with SHS exposure had similar effects on the development of KSD than ever-smokers (OR, 1.223; 95% CI, 0.852 to 1.756). CONCLUSION: Our study suggests that both smoking and SHS are a risk factor for developing KSD and that the impact of SHS is not inferior to that of smoking. TRIAL REGISTRATION: The study was conducted in accordance with the Declaration of Helsinki and approved by the Institutional Review Board of Kaohsiung Medical University Hospital (KMUHIRB-E(I)-20,210,058).

Photonic Fock state generation using superradiance.

Photonic Fock states are the most basic quantum states of a radiation field, but arbitrary number states are still difficult to produce. Here we propose to use superradiant atoms in a chiral waveguide to generate multi-photon Fock states deterministically. We calculate the explicit forms of the output quantum photonic states and their correlation functions. We further establish the conditions for the output optical fields to approach the Fock states asymptotically.

Ultrafast reconfigurable optical logic gates using a nonlinear metallodielectric grating.

Reconfigurable optical logic gates are developed through the design and optimization of a metallic grating with a colloidal nonlinear dielectric. The device has a structurally enhanced nonlinearity, improving power consumption and speed. Detailed design strategy and simulations for several common logic gates are provided. Using materials readily available in common CMOS processing technologies, the gates switch in sub-picosecond scales with a driving irradiance of around $200\; {{\rm MW/cm}^2}$.

Correlation signatures for a coherent three-photon scattering in waveguide quantum electrodynamics.

We study the correlation signatures of a coherent three-photon scattering process by computationally investigating scattering photon wavefunctions, correlation functions, and nonlinear conditional phases. It is shown that both the three-photon bound states and the hybrid states, which consist of two-photon bound states and one unbound photon, contribute to all the correlation signatures. All computational correlation signatures are in good agreement with a recent experiment, wherein a weak coherent photonic state propagates through a quantum nonlinear Rydberg medium [Liang et al., Science359, 783 (2018)SCIEAS0036-807510.1126/science.aao7293].

Efficient two-photon excitation by photonic dimers.

In this Letter, we show that photonic dimers, the quantum mechanical bound states of two photons, enable efficient nonlinear two-photon excitation, primarily due to the Lorentzian energy anti-correlation and to the temporal proximity between the constituent photons. We analytically and numerically demonstrate the order-of-magnitude improvement of the excitation efficiency per photon by the photonic dimers over the ultrashort pulses from a laser. We further show that, owing to the high excitation efficiency, the two-photon transition rate by photonic dimers deviates from the well-known linear intensity dependence at low intensities. Possible approaches for generating the photonic dimers in semiconductor platforms are also investigated.

Exact dissipation model for arbitrary photonic Fock state transport in waveguide QED systems.

We present an exact dissipation model for correlated photon transport in waveguide QED systems. This model rigorously incorporates the infinitely many degrees of freedom of the full three-dimensional photonic scattering channels in the non-excitable ambient environment. We show that the photon leakages to the scattering channels can be accounted for by a reduced Hamiltonian and a restricted eigen-state, with a resultant atomic dissipation. This model is valid for arbitrary photonic Fock and coherent states.

Photon antibunching and bunching in a ring-resonator waveguide quantum electrodynamics system.

We numerically investigate the photonic state generation and its nonclassical correlations in a ring-resonator waveguide quantum electrodynamics system. Specifically, we discuss photon antibunching and bunching in various scenarios, including the imperfect resonator with backscattering and dissipations. Our numerical results indicate that an imperfect ring resonator with backscattering can enhance the quality of antibunching. In addition, we also identify the quantum photonic halo phenomenon in the photon scattering dynamics and the shoulder effect in the second-order correlation function.

Numerical approach to statistical properties of resonance fluorescence.

We formulate a numerical scheme to investigate the correlation of photons scattered by a two-level atom coupled to a waveguide, and compute the second-order correlation function. We also show that a three-dimensional resonance fluorescence experiment can be mapped into the one-dimensional situation studied here. The correlation functions for both cases show excellent agreement.

Ultralong photonic nanojet formed by a two-layer dielectric microsphere.

A photonic nanojet is a highly focused optical beam with a subwavelength waist on the shadow side of the sphere. Successful far-field applications require long nanojets that extend afar. Using the exact Mie theory, we show that ultralong nanojets can be generated using a simple two-layer microsphere structure, using conventional optical materials that are readily available. In particular, we show that for a glass-based two-layer microsphere, the nanojet has an extension of 22 wavelengths. We also show that long nanojets can be formed using semiconductors at infrared frequencies in free space.

Low-threshold optical bistabilities in ultrathin nonlinear metamaterials.

Optical bistability typically occurs only when the optical thickness in the device or the input light power is unfavorably large. Here we show that, for a class of plasmonic metamaterials consisting of ultrathin holey metallic plates filled with nonlinear materials, the optical bistability can occur with an ultralow excitation power. We present a realistic design working at 0.2 THz and perform full-wave simulations to quantitatively study its optical bistability properties. An analytical model is developed to explain the inherent physics and provides a general design guideline for future development.

Pituitary apoplexy induced by Gonadotropin-releasing hormone agonists for treating prostate cancer-report of first Asian case.

We present the first Asian case of a 77-year-old man who developed pituitary apoplexy (PA) soon after gonadotropin-releasing hormone agonist (GnRHa) (leuprorelin) injection to treat prostate cancer. Headache, ophthalmoplegia, visual field deficit, nausea, and vomiting are the typical characteristics of pituitary apoplexy. Though the occurrence rate is rare, the consequence of this condition can vary from mild symptoms such as headache to life-threatening scenarios like conscious change. Magnetic resonance imaging is the best imaging modality to detect PA and sublabial trans-sphenoid pituitary tumor removal can resolve most of PA symptoms and is so far the best solution in consensus. We also review 11 previous reported cases receiving GnRHa for androgen deprivation therapy of prostate cancer, and hope to alert clinicians to use GnRHa with caution.

Primary small cell carcinoma of kidney after renal transplantation: a case report and literature review.

Extrapulmonary small cell carcinoma (EPSCC) is a rare neoplasm comprising 2.5% to 5% of small cell carcinomas (SCCs). Bladder SCC is the most common site of genitourinary tract. Primary renal SCC is extremely rare. We report a case of primary SCC of the kidney which is rarely reported in the urinary tract and presents an aggressive clinical picture. A 59-year-old female visited a urologic clinic with complaint of persistent left flank soreness 10 years after undergoing renal transplantation. Abdominal computed tomography showed a left renal pelvis tumor. After the patient received left nephroureterectomy with bladder cuff resection, her pathology results showed SCC. After surgery, she received adjuvant systemic chemotherapy, and her recovery has been uneventful as of 8 months. Primary renal SCC presents with an advanced tumor stage and a short median survival period, therefore early intervention and close follow-up are recommended.

Penile squamous cell carcinoma originating from a silicone granuloma.

Penile enlargement has been a controversial issue throughout history. We presented a patient who had undergone a procedure involving the injection of subcutaneous liquid silicone over the penile shaft four years prior. He developed long-term negative consequences from inflammatory granulomas. The patient's condition worsened over time, causing pain and impairing his sexual function. Eventually, he was diagnosed with penile SCC caused by chronic inflammation. Although it is rare, it is important to be aware of this probability because, compared to penile granuloma resection for symptom relief, penile SCC requires a comprehensive survey and more aggressive surgical intervention.

The association between menopause, postmenopausal hormone therapy, and kidney stone disease in Taiwanese women.

PURPOSE: The association between menopause, postmenopausal hormone therapy, and kidney stone disease has long been a topic of discussion and is still unclear. Moreover, most previous research has focused on Caucasians. Therefore, we aimed to explore this issue in an Asian population. METHODS: In this cross-sectional study, we enrolled female participants aged between 30 and 70 years from the Taiwan Biobank. The presence of kidney stone disease (KSD) was defined through a self-reported questionnaire. The participants were divided into two groups according to the presence of menopause; premenopausal and postmenopausal groups. The associations among menopause, postmenopausal hormone therapy, and KSD were examined using binary logistic regression models. RESULTS: A total of 17,460 women with available information were recruited, including 5976 in the premenopausal group and 11,484 in the postmenopausal group. Compared to the premenopausal group, the postmenopausal group had a significantly higher prevalence of KSD (3% vs. 6%). The odds ratio for KSD was higher in the postmenopausal group than in the premenopausal group (odds ratio = 1.50; 95% confidence interval = 1.17-1.92) after adjusting for confounders. We also examined associations between the type of menopause (natural and surgical) and KSD, and found that both types of menopause were associated with KSD in age-adjusted and multivariable models. Compared with those who had never received postmenopausal hormone therapy, those who had received postmenopausal hormone therapy were not associated with a higher risk of KSD. CONCLUSIONS: Our study suggests that natural and surgical menopause were associated with KSD. However, we found no association between the postmenopausal hormone therapy and KSD in the postmenopausal women.

Efficient single-photon frequency conversion using a Sagnac interferometer.

We propose a scheme for efficient optical frequency conversion at the single-photon power level. The scheme exploits the quantum interference of single-photon states at a three-level quantum emitter coupled to a Sagnac interferometer. We show that this device can achieve single-photon frequency up- or down-conversion with near unity efficiency.

Abdominal fat distribution on computed tomography predicts ureteric calculus fragmentation by shock wave lithotripsy.

OBJECTIVES: To assess the effects of abdominal fat on shock wave lithotripsy (SWL). We used pre-SWL unenhanced computed tomography (CT) to evaluate the impact of abdominal fat distribution and calculus characteristics on the outcome of SWL. METHODS: One hundred and eighty-five patients with a solitary ureteric calculus treated with SWL were retrospectively reviewed. Each patient underwent unenhanced CT within 1 month before SWL treatment. Treatment outcomes were evaluated 1 month later. Unenhanced CT parameters, including calculus surface area, Hounsfield unit (HU) density, abdominal fat area and skin to calculus distance (SSD) were analysed. RESULTS: One hundred and twenty-eight of the 185 patients were found to be calculus-free following treatment. HU density, total fat area, visceral fat area and SSD were identified as significant variables on multivariate logistic regression analysis. The receiver-operating characteristic analyses showed that total fat area, para/perirenal fat area and visceral fat area were sensitive predictors of SWL outcomes. CONCLUSION: This study revealed that higher quantities of abdominal fat, especially visceral fat, are associated with a lower calculus-free rate following SWL treatment. Unenhanced CT is a convenient technique for diagnosing the presence of a calculus, assessing the intra-abdominal fat distribution and thereby helping to predict the outcome of SWL. KEY POINTS: • Unenhanced CT is now widely used to assess ureteric calculi. • The same CT protocol can provide measurements of abdominal fat distribution. • Ureteric calculi are usually treated by shock wave lithotripsy (SWL). • Greater intra-abdominal fat stores are generally associated with poorer SWL results.

The Safety and Efficacy of Vela Laser En-Bloc Endoscopic Resection versus Conventional Transurethral Resection of Bladder Tumor-A Single Center Experience.

(1) Background: The current gold standard treatment of bladder cancer is conventional transurethral resection of the bladder tumor (CTURBT) using monopolar or bipolar resectoscopes. Laser en-bloc resection of the bladder tumor (LERBT) could achieve a higher quality of the specimen, reduce perioperative complications, and decrease the recurrence rate. Here, we compare the efficacy and safety of en-bloc Vela laser resection versus the conventional monopolar/bipolar resection; (2) Methods: A total of 100 clinically cT1-2 patients with bladder cancer were retrospectively reviewed in this study. Among these patients, 50 patients received LERBT, and 50 patients received CTURBT. The baseline characteristics, operation variables, and clinical outcomes were collected. The primary performance was the presence of muscle layer in the specimen. Perioperative complications and recurrence-free survival (RFS) were also compared. Independent t-test, Chi-square test, Kaplan-Meier curves, and the Cox-regression model were used in the analysis; (3) Results: The median age of the patients in the laser and resectoscope groups was 69.2 and 68.0 years old, respectively. The statistical difference in the presence of the detrusor muscle was 92.0% in the laser group and 70.0% in the CTURBT group (p = 0.005). A lower incidence of bladder perforation (p = 0.041) and major surgical complications (p = 0.046) in the LEBRT group was observed. We found no differences in operation duration, catheterization time, and hospitalization time after adjustment. Additionally, there was no statistical difference in RFS after a median follow-up time of 25 months; (4) Conclusions: Endoscopic laser en-bloc resection of bladder tumor with Vela laser is an effective method with higher muscle inclusion rate and fewer complications.

Betel Nut Chewing Is Associated with the Risk of Kidney Stone Disease.

(1) Background: Betel nut chewing injures bodily health. Although, the relationship between betel nut chewing and kidney stone disease (KSD) is unknown. (2) Methods: We analyzed 43,636 men from Taiwan Biobank. We divided them into two groups on the status of betel nut chewing, the never-chewer and ever-chewer groups. Self-reported diagnosed KSD was defined as the subject's medical history of KSD in the questionnaire. Logistic regression was used to analyze the association of betel nut chewing and the risk of KSD. (3) Results: The mean age of subjects in the present study was 50 years, and 16% were ever-chewers. KSD was observed in 3759 (10.3%) and 894 (12.6%) participants in the group of never-chewer and ever-chewer groups, respectively. Higher risk of KSD was found in participants with betel nut chewing compared with to without betel nut chewing (odds ratio (OR), 1.094; 95% confidence interval (95% CI), 1.001 to 1.196). Furthermore, the daily amounts of betel nut chewing >30 quids was associated with a more than 1.5-fold increase (OR, 1.571; 95% CI, 1.186 to 2.079) in the odds of KSD; (4) Conclusions: Our study suggests that betel nut chewing is associated with the risk of KSD and warrants further attention to this problem.

Single-photon diode by exploiting the photon polarization in a waveguide.

A single-photon optical diode operates on individual photons and allows unidirectional propagation of photons. By exploiting the unique polarization configuration in a waveguide, we show here that a single-photon optical diode can be accomplished by coupling a quantum impurity to a passive, linear optical waveguide which possesses a locally planar, circular polarization. We further show that the diode provides a near unitary contrast for an input pulse with finite frequency bandwidth and can be implemented in a variety of types of waveguides. Moreover, the performance of the diode is not sensitive to the intrinsic dissipation of the quantum impurity.