Photon-pair source working in a silicon-based detector wavelength range using tapered micro/nanofibers.

The development of quantum photonic information technology demands high-quality photon sources. Here we demonstrate a low-noise and high-speed photon source generated by the spontaneous four-wave mixing process in a micro/nanofiber (MNF). The pair generation in a MNF is tailorable by controlling its diameter and designed for creating signal and idler photons in the silicon-based detector wavelength range, yielding high detection efficiency and coincidence count rate. This MNF photon source can be coupled to other fiber systems with negligible coupling loss and can be efficiently exploited as fiber-based quantum light sources for quantum information applications.

Stark Tuning of Single-Photon Emitters in Hexagonal Boron Nitride.

Single-photon emitters play an essential role in quantum technologies, including quantum computing and quantum communications. Atomic defects in hexagonal boron nitride ( h-BN) have recently emerged as new room-temperature single-photon emitters in solid-state systems, but the development of scalable and tunable h-BN single-photon emitters requires external methods that can control the emission energy of individual defects. Here, by fabricating van der Waals heterostructures of h-BN and graphene, we demonstrate the electrical control of single-photon emission from atomic defects in h-BN via the Stark effect. By applying an out-of-plane electric field through graphene gates, we observed Stark shifts as large as 5.4 nm per GV/m. The Stark shift generated upon a vertical electric field suggests the existence of out-of-plane dipole moments associated with atomic defect emitters, which is supported by first-principles theoretical calculations. Furthermore, we found field-induced discrete modification and stabilization of emission intensity, which were reversibly controllable with an external electric field.

Switching between transparent and translucent states of a two-dimensional liquid crystal phase grating device with crossed interdigitated electrodes.

We report an electrically-switchable two-dimensional liquid crystal (LC) phase grating device for window display applications. The device consists of the top and bottom substrates with crossed interdigitated electrodes and vertically-aligned LCs sandwiched between the two substrates. The device, switchable between the transparent and translucent states by applying an electric field, can provide high haze by the strong diffraction effect thanks to a large spatial phase difference with little dependence on the azimuth angle. We found that the device has outstanding features, such as a low operating voltage, high transparency, and wide viewing angle characteristics in the transparent state and high haze in the translucent state. Moreover, we achieved submillisecond switching between transparent and translucent states by employing the overdrive scheme and a vertical trigger pulse.

Increase in harm avoidance by genetic loading of schizophrenia.

BACKGROUND: Schizophrenia is highly familial neuropsychiatric disorder with heritability estimated at 60% to 90%. Even unaffected first-degree relatives of schizophrenia manifested some neuropsychologic abnormalities, neurologic soft sign, and morphologic anomalies. Because personality traits are under genetic influence and considerable heritability, we intended to evaluate temperament and character of first-degree relatives of schizophrenia and the influence of schizophrenia genetic loading on their temperament and character. METHODS: Temperament and Character Inventory was completed by 97 first-degree relatives of schizophrenia or schizoaffective disorder, 48 schizophrenic probands (44 patients with schizophrenia and 4 patients with schizoaffective disorder), and 106 control subjects. Within first-degree relatives, parents who have additional probands with schizophrenia spectrum disorder in their ascendant or collateral pedigree and siblings who have offspring with schizophrenia spectrum disorder were defined as presumed carriers (n = 20). Group differences in Temperament and Character Inventory scores were compared using a mixed-model analysis of variance with family as a random effect and age as a covariate. RESULTS: Harm avoidance (HA) scores increased in the order of control subjects, the first-degree relatives, and probands. Among the relatives, presumed carriers, but not presumed noncarriers, had higher HA compared with control subjects. In addition, probands showed significantly low reward dependence, low self-directedness, and low cooperativeness scores compared with the first-degree relatives and control subjects. Probands had also higher self-transcendence scores than the first-degree relatives and had lower persistence scores than control subjects. CONCLUSIONS: Our findings that HA increases in proportion to the genetic loading of schizophrenia suggest that it may be a potential endophenotype of schizophrenia.

Interactive effects of background facial emotion stimulus and target salience on sustained attention performance in schizophrenia.

Schizophrenia impairs both facial emotion processing and sustained attention. Through separate studies, it is known that the presence of a task-irrelevant facial stimulus disproportionately interferes with performance, whereas increasing the salience of task stimulus improves performance during a sustained attention task in patients with schizophrenia. We wished to investigate a potential interaction effect of background facial emotion expression (black and white happy faces vs. grey oval) and target stimulus salience (bright white vs. grey) using the Continuous Performance Test-Identical Pairs version (CPT-IP) in patients with schizophrenia. Thirty-six patients with schizophrenia and 28 healthy control subjects completed 4 different versions of the CPT-IP. We found that healthy controls exhibited higher signal detection sensitivity (d') when salient target stimuli were presented on the facial background than when the same stimuli were presented on the grey-oval background. By contrast, patients were not affected by background stimuli when target number stimuli were salient. When target number stimuli were not salient, both patients and controls showed higher d' in the grey-oval background condition compared with the facial background condition. This study highlight the significance of stimulus salience during CPT-IP in schizophrenia as background stimuli did not produce a differential effect on performance. Our results suggest that, in the situations where facial emotion stimuli are present, patients' sustained attention can be deteriorated and that the use of salient materials is important in improving performance in schizophrenia.

Temporary placement of a newly designed, fully covered, self-expandable metal stent for refractory bile leaks.

Bile leaks remain a significant cause of morbidity for patients undergoing laparoscopic cholecystectomy. Leakage from an injured duct of Luschka (subvesical duct) follows the cystic duct as the most common cause of postcholecystectomy bile leaks. Although endoscopic sphincterotomy, plastic-stent placement, or nasobiliary-drain placement are effective in healing biliary leaks, in patients in whom leakage persists and the symptoms worsen despite conventional endoscopic treatment, re-exploration with laparoscopy and ligation of the injured subvesical duct should be considered. We present herein the case of a 31-year-old woman with refractory bile leakage from a disrupted subvesical duct after cholecystectomy that could not be managed with endoscopic sphincterotomy and plastic-stent placement. A newly designed, fully covered, self-expandable metal stent (FC-SEMS) was successfully placed for the treatment of refractory bile leaks in this patient. It appears that temporary placement of an FC-SEMS is technically feasible and provides an effective alternative to surgical therapy for refractory bile leaks after cholecystectomy.

Sustained attention in the context of emotional processing in patients with schizophrenia.

Patients with schizophrenia show dysfunction in sustained attention and facial emotion processing. We investigated the interplay between sustained attention and emotion by presenting emotional faces as background during AX-CPT in patients with schizophrenia. Nineteen schizophrenia patients and 21 healthy control subjects participated. We presented AX-CPT number stimuli superimposed on the nose of background facial expressions (happy, neutral or sad) over three experimental blocks for each emotion. Signal detection sensitivity (A') and reaction time were measured. Patients showed a steeper sensitivity decline when happy faces (compared with sad faces) were presented as background stimuli. By contrast, controls' sensitivity was not affected by the background facial emotion stimuli. Across the emotion conditions, the decline of sensitivity over time was evident in patients, but not in controls. To our knowledge, the present study is the first to explore a change in sustained attention accompanied by simultaneous processing of emotional faces in schizophrenia patients. Our findings suggest that mechanisms underlying continuous performance test (CPT) performance decline over time and facial emotion deficit may interact with each other in patients with schizophrenia.

Accept or refuse? A pilot study of patients' perspective on participating as imaginary research subjects in schizophrenia.

OBJECTIVE: The goal of the present study was to evaluate demographic and clinical factors that affect the intention to participate in commonly-conducted research in patients with schizophrenia. METHODS: Thirty-four outpatients with a diagnosis of schizophrenia were enrolled in this study. They were asked whether they would have any intention to participate in four imaginary studies: a simple questionnaire, a genetic study, a study of complex tasks and a risky study. We analyzed the differences in general psychopathology, insight and demographic characteristics of the participants according to their responses (acceptance or refusal) to the four proposed studies. RESULTS: Younger and better-educated patients tended to decline participation in a risky study. Patients with a longer duration of regular psychiatric follow-ups tended to willingly participate in the simple questionnaire. There were no overall statistical differences in general psychopathology and insight between patients who agreed or declined to participate in studies. CONCLUSION: Age and education level may be factors that influence decisions to participate in schizophrenia studies. Further research is needed to confirm and expand on the current findings.

Time to rehospitalization of clozapine versus risperidone in the naturalistic treatment of comorbid alcohol use disorder and schizophrenia.

Clozapine is known to be effective in treating schizophrenia patients with comorbid alcohol use disorders (AUD). However, few prospective studies have examined the effect of clozapine on community survival of the patient, which is one of the most important indicators of success for patients with schizophrenia. In this prospective, naturalistic, observational, community-survival-analysis study, we compared the effect of clozapine and risperidone on two-year psychiatric hospitalization rate and time to hospitalization in the treatment of patients with schizophrenia and comorbid AUD. We found that the clozapine treated patients were readmitted to hospital significantly later (mean survival=526.5 days, n=25 patients) than the risperidone treated patients (mean survival=420.4 days, n=36 patients). The survival curve for the clozapine-treated patients was significantly different from that of the risperidone treated patients (log-rank test, df=1, p=.045). At the end of the two-year study period, 75% of the risperidone treated patients had been admitted to the hospital, compared to only 48% of the clozapine treated patients. These findings suggest that clozapine should be considered for the treatment of schizophrenia patients with comorbid AUD. However, due to the limitations of this study, further studies will be required to confirm these findings.

Novelty-seeking among schizophrenia patients with comorbid alcohol abuse.

Since characterological characteristics of patients with schizophrenia and comorbid alcohol abuse are not well established, we compared outpatients with DSM-IV schizophrenia, with (n = 51) and without alcohol-abuse (n = 51), matched for sex, age, IQ, and symptom severity, using the Temperament and Character Inventory. Dual-diagnosis patients showed highly selective greater novelty seeking.