Efficient generation of single photons by quantum dots embedded in bullseye cavities with backside dielectric mirrors.

Single photons are pivotal building blocks for photonic quantum technologies. Semiconductor quantum dots are promising candidates for optimal single photon sources in terms of purity, brightness and indistinguishability. Here we embed quantum dots into bullseye cavities with a backside dielectric mirror to enhance the collection efficiency up to near 90%. Experimentally, we achieve a collection efficiency of 30%. The auto-correlation measurements reveal a multiphoton probability below 0.05±0.005. A moderate Purcell factor of 3.1 is observed. Furthermore, we propose a scheme for laser integration as well as fiber coupling. Our results represent a step forward to the practical plug-and-play single photon sources.

Generation of Polarization-Entangled Photons from Self-Assembled Quantum Dots in a Hybrid Quantum Photonic Chip.

Integration of entangled photon sources in a quantum photonic chip has enabled the most envisioned quantum photonic technologies to be performed in a compact platform with enhanced complexity and stability as compared to bulk optics. However, the technology to generate entangled photon states in a quantum photonic chip that are neither probabilistic nor restricted to low efficiency is still missing. Here, we introduce a hybrid quantum photonic chip where waveguide-coupled self-assembled quantum dots (QDs) are heterogeneously integrated onto a piezoelectric actuator. By exerting an anisotropic stress, we experimentally show that the fine structure splitting of waveguide-coupled quantum dots can be effectively eliminated. This allows for the demonstration of chip-integrated self-assembled QDs for generating and routing polarization-entangled photon pairs. Our results presented here would open up an avenue for implementing on-demand quantum information processing in a quantum photonic chip by employing all-solid-state self-assembled quantum dot emitters.

The effect of different screw-rod design on the anti-rotational torque: a biomechanical comparison of three conventional screw-rod constructs.

BACKGROUND: Screw-rod constructs have been widely used to correct spinal deformities, but the effects of different screw-rod systems on anti-rotational torque have not been determined. This study aimed to analyze the biomechanical effect of different rod-screw constructs on anti-rotational torque. METHODS: Three conventional spinal screw-rod systems (Legacy, RF-F-10 and USSII) were used to test the anti-rotational torque in the material test machine. ANOVA was performed to evaluate the anti-rotational capacity of different pedicle screws-rod constructs. RESULTS: The anti-rotational torque of Legacy group, RF-F-10 group and USSII group were 12.3 ± 1.9 Nm, 6.8 ± 0.4 Nm, and 3.9 ± 0.8 Nm, with a P value lower than 0.05. This results indicated that the Legacy screws-rod construct could provide a highest anti-rotation capacity, which is 68% and 210% greater than RF-F-10 screw-rod construct and USSII screw-rod respectively. CONCLUSIONS: The anti-rotational torque may be mainly affected by screw cap and groove design. Our result showed the anti-rotational torque are: Legacy system > RF-F-10 system > USSII system, suggesting that appropriate rod-screw constructs selection in surgery may be vital for anti-rotational torque improvement and preventing derotation correction loss.

Radiographic and clinical assessment on the accuracy and complications of C1 anterior lateral mass and C2 anterior pedicle screw placement in the TARP-III procedure: a study of 106 patients.

PURPOSE: To investigate the (1) radiographic and clinical accuracy of C1 anterior lateral mass screw (C1ALMS) and C2 anterior pedicle screw (C2APS) placement in the transoral atlantoaxial reduction plate (TARP)-III procedure, (2) screw insertion-associated clinical complications and (3) fusion status between C1 and C2. METHODS: Radiographic and clinical data were obtained from the electronic medical record system. Studies were carried out to assess the accuracy of C1ALMS and C2APS placement, the screw insertion-associated clinical complications and the fusion status between C1 and C2. Placement of the screws was assessed using the modified All India Institute of Medical Sciences outcome-based classification. RESULTS: Two-hundred and twelve C1ALMS and 207 C2APS in 106 patients were assessed. The ideal accurate rates were 92.0% (195) and 53.1% (110), and the acceptable accurate rates were 97.6% (207) and 87.0% (180), respectively. One patient died postoperatively due to C2 screw misplacement. There were no symptoms of neurologic and vertebral artery injuries in the rest of the patients. 102 patients (97.1%) achieved solid fusion between C1 and C2. No instrumentation failure due to delayed union or nonunion was observed. CONCLUSION: C1ALMS placement in TARP-III procedures appears to be safe. The cortical breach rate of C2APS is high though clinically the neurovascular complication rate is similar to that of posterior atlantoaxial procedures. Advanced navigation strategies may help improve the accuracy of C2APS placement and decrease potential complications.

A Novel Laryngopharyngeal Reflux Disease Model for Bama Pigs.

OBJECTIVE: To develop a novel Laryngopharyngeal Reflux Disease (LPRD) model in Bama pigs through endoscopic cricopharyngeal myotomy. METHODS: A total of eight 8-month-old Bama pigs were randomly assigned to either the control or surgery group. Prior to intervention, upper esophageal sphincter (UES) manometry and laryngopharyngeal Dx-pH monitoring were conducted to establish baseline physiological parameters for each pig. Subsequently, the surgery group underwent endoscopic cricopharyngeal myotomy, while the control group did not. Two weeks postintervention, these procedures were repeated to evaluate changes in UES contractility and the occurrence of reflux events. At week eight postsurgery, mucosal tissues from both groups were harvested for histological analysis. Hematoxylin and eosin (H&E) staining was used to assess inflammation, while transmission electron microscopy (TEM) examined alterations in intercellular spaces and desmosomes. RESULTS: The mean UES pressures in the control and surgery groups were 59 ± 9 mmHg and 68 ± 12 mmHg, respectively. In the surgery group, there was a significant decrease in UES pressure 2weeks after the operation compared to preoperative values (P = 0.005), whereas no significant change was observed in the control group (P = 0.488). Laryngopharyngeal reflux (LPR) was successfully induced in the surgery group as evidenced by reflux events with pH <5.0, which were not detected in the control group. HE staining revealed marked inflammatory cell infiltration and submucosal gland expansion in throat tissues of the surgery group Bama pigs. TEM further showed enlarged intercellular spaces and reduced desmosome numbers in the laryngopharyngeal epithelium compared to controls. CONCLUSION: Given analogous throat epithelial structures to humans, Bama pigs are an appropriate species for an LPRD animal model. Endoscopic cricopharyngeal myotomy effectively induces LPR and observable pathological changes in Bama pigs, providing a valuable platform for further research into LPRD pathophysiology.

Continuous and efficient elastocaloric air cooling by coil-bending.

Elastocaloric cooling has emerged as an eco-friendly technology capable of eliminating greenhouse-gas refrigerants. However, its development is limited by the large driving force and low efficiency in uniaxial loading modes. Here, we present a low-force and energy-efficient elastocaloric air cooling approach based on coil-bending of NiTi ribbons/wires. Our air cooler achieves continuous cold outlet air with a temperature drop of 10.6 K and a specific cooling power of 2.5 W g-1 at a low specific driving force of 26 N g-1. Notably, the cooler shows a system coefficient of performance of 3.7 (ratio of cooling power to rotational mechanical power). These values are realized by the large specific heat transfer area (12.6 cm2 g-1) and the constant cold zone of NiTi wires. Our coil-bending system exhibits a competitive performance among caloric air coolers.

Individual treatment strategy of thyroglossal duct cyst carcinoma: a case report.

Background: Neoplasia of ectopic thyroid components is relatively rare in thyroglossal duct cysts. We report a case of histopathologically confirmed papillary thyroid carcinoma in a thyroglossal duct cyst, discuss its clinical characteristics of, and provide reference for diagnosis and treatment. Case Description: We presented a 25-year-old female went to hospital because of "a tumor in her neck". She was preoperatively diagnosed with thyroglossal duct cyst by cervical ultrasound, and enhanced computed tomography (CT). However, the solid component of the mass suggested intracystic neoplasia. She underwent Sistrunk surgical resection, and postoperative histopathology showed thyroglossal duct cyst, and papillary thyroid carcinoma in the cyst wall. The patient had no high-risk factors and had a low risk of recurrence. After full disclosure, the patient chose close follow-up, and to date there has been no recurrence. Conclusions: There are controversies regarding the origin of thyroglossal duct cyst carcinoma and the extent of surgery required, and a lack of unified treatment guidelines. We recommend tailoring individualized treatment based on individual risk stratification. By reporting this case, we hope to inform surgeons of the various abnormalities that may occur in ectopic thyroid tissue.

Bright semiconductor single-photon sources pumped by heterogeneously integrated micropillar lasers with electrical injections.

The emerging hybrid integrated quantum photonics combines the advantages of different functional components into a single chip to meet the stringent requirements for quantum information processing. Despite the tremendous progress in hybrid integrations of III-V quantum emitters with silicon-based photonic circuits and superconducting single-photon detectors, on-chip optical excitations of quantum emitters via miniaturized lasers towards single-photon sources (SPSs) with low power consumptions, small device footprints, and excellent coherence properties is highly desirable yet illusive. In this work, we present realizations of bright semiconductor SPSs heterogeneously integrated with on-chip electrically-injected microlasers. Different from previous one-by-one transfer printing technique implemented in hybrid quantum dot (QD) photonic devices, multiple deterministically coupled QD-circular Bragg Grating (CBG) SPSs were integrated with electrically-injected micropillar lasers at one time via a potentially scalable transfer printing process assisted by the wide-field photoluminescence (PL) imaging technique. Optically pumped by electrically-injected microlasers, pure single photons are generated with a high-brightness of a count rate of 3.8 M/s and an extraction efficiency of 25.44%. Such a high-brightness is due to the enhancement by the cavity mode of the CBG, which is confirmed by a Purcell factor of 2.5. Our work provides a powerful tool for advancing hybrid integrated quantum photonics in general and boosts the developments for realizing highly-compact, energy-efficient and coherent SPSs in particular.

In-situ growth of metal phosphide-black phosphorus heterojunction for highly selective and efficient photocatalytic carbon dioxide conversion.

Two-dimensional black phosphorus-based nanomaterials with distinct properties have emerged as fascinating semiconductor photocatalysts. In this work, metal phosphide (M-P: Co2P, Ni-P and Cu-P) in-situ growth on black phosphorus (BP) nanosheets is developed for photocatalytic carbon dioxide conversion. The M-P/BP heterojunction, especially Co2P/BP materials, show largely improved carbon dioxide capturing ability and charge separation efficiency. More importantly, the catalytic active Co in Co2P/BP can activate the adsorbed CO2 molecules and further boost the electron-hole separation process, which improves the photocatalytic activity for carbon dioxide reduction. The obtained Co2P/BP presented a photocatalytic CO production rate of 255.1 µmol/g∙h, which was almost two times higher than that of bulk BP (141.8 µmol/g∙h). This work shows that M-P/BP materials have high potential in photocatalytic CO2 reduction due to their high stability and performance.

Efficient second harmonic generation by harnessing bound states in the continuum in semi-nonlinear etchless lithium niobate waveguides.

Integrated photonics provides unprecedented opportunities to pursue advanced nonlinear light sources with low-power consumptions and small footprints in a scalable manner, such as microcombs, chip-scale optical parametric oscillators and integrated quantum light sources. Among a variety of nonlinear optical processes, high-efficiency second harmonic generation (SHG) on-chip is particularly appealing and yet challenging. In this work, we present efficient SHG in highly engineerable semi-nonlinear waveguides consisting of electron-beam resist waveguides and thin-film silicon nitride (SiN)/lithium niobate (LN). By carefully designing octave-separating bound states in the continuum (BICs) for the nonlinear interacting waves in such a hybrid structure, we have simultaneously optimized the losses for both fundamental frequency (FF) and second harmonic (SH) waves and achieved modal phasing matching and maximized the nonlinear modal overlap between the FF and SH waves, which results in an experimental conversion efficiency up to 4.05% W-1cm-2. Our work provides a versatile and fabrication-friendly platform to explore on-chip nonlinear optical processes with high efficiency in the context of nanophotonics and quantum optics.

The clinical characteristics and anatomical variations in patients with intractable unilateral Meniere's disease with and without migraine.

BACKGROUND: Migraine is more common in Meniere's disease patients, who have some certain anatomical variations. But there are limited studies focusing on the anatomical variations in patients with Meniere's disease and migraine. OBJECTIVE: To explore the clinical and anatomical features in Meniere's disease patients with and without migraine, determining whether the coexistence of migraine can be used as a basis for clinical subtyping of Meniere's disease. METHODS: Ninety-five Meniere's disease patients and ninety-five healthy subjects matched with age, sex were selected. A detailed questionnaire based on the diagnosis criteria of Meniere's disease and migraine was designed. According to the CT scan, we divided the mastoid cell system of all the subjects into two types: well-pneumatization type and poor-pneumatization type. Meanwhile, the shortest distance between the sigmoid sinus and the posterior wall of the external acoustic canal was measured. RESULTS: Compared with those without migraine, Meniere's disease patients with migraine had a higher female comorbidity, poorer mastoid pneumatization, shorter distance between the sigmoid sinus and posterior wall of the external acoustic canal, longer history, higher frequency of vertigo attacks and better average hearing threshold. CONCLUSIONS: In our study, anatomical features as well as several clinical manifestations were proved to differ significantly between Meniere's disease patients with and without migraine, indicating the coexistence of migraine may be one standard for the clinical subtyping of Meniere's disease.

Tailoring solid-state single-photon sources with stimulated emissions.

The coherent interaction of electromagnetic fields with solid-state two-level systems can yield deterministic quantum light sources for photonic quantum technologies. To date, the performance of semiconductor single-photon sources based on three-level systems is limited mainly due to a lack of high photon indistinguishability. Here we tailor the cavity-enhanced spontaneous emission from a ladder-type three-level system in a single epitaxial quantum dot through stimulated emission. After populating the biexciton (XX) of the quantum dot through two-photon resonant excitation, we use another laser pulse to selectively depopulate the XX state into an exciton (X) state with a predefined polarization. The stimulated XX-X emission modifies the X decay dynamics and improves the characteristics of a polarized single-photon source, such as a source brightness of 0.030(2), a single-photon purity of 0.998(1) and an indistinguishability of 0.926(4). Our method can be readily applied to existing quantum dot single-photon sources and expands the capabilities of three-level systems for advanced quantum photonic functionalities.

IL-1ß-activated mTORC2 promotes accumulation of IFN-γ+ γδ T cells by upregulating CXCR3 to restrict hepatic fibrosis.

Liver fibrosis represents a severe stage of liver damage, with hallmarks of inflammation, hepatic stellate cell activation, and extracellular matrix accumulation. Although previous studies demonstrated γδ T cells are involved in liver fibrosis, the precise role and mechanisms of γδ T cells migrating to fibrotic liver have not been elucidated. Here, we aim to investigate the functional subsets of γδ T cells in hepatic fibrosis and to further explore the underlying causes and drivers of migration. In this study, we observed that γδ T cells accumulate in fibrotic liver. Adoptive transfer of γδ T, especially Vγ4 γδ T subset, can significantly alleviate liver fibrosis. In addition, CCl4 treatment also leads to activation of mTOR signaling in γδ T cells. Genetic deletion of the Rictor gene, but not Raptor, in γδ T cells markedly exacerbated liver fibrosis. Mechanistically, CCl4-induced liver injury causes macrophage accumulation in the liver, and IL-1ß produced by macrophages promotes mTORC2 signaling activation in γδ T cells, which upregulates T-bet expression and eventually promotes CXCR3 transcription to drive γδ T cell migration. Moreover, hepatic γδ T cells ameliorated liver fibrosis by cytotoxicity against activated hepatic stellate cells in FasL-dependent manner, and secrete IFN-γ to inhibit the differentiation of pro-fibrotic Th17 cells. Thus, IL-1ß-activated mTORC2 signaling in γδ T cells upregulates CXCR3 expression, which is critical for IFN-γ+ γδ T cells migration into the liver and amelioration of liver fibrosis. Our findings indicate that targeting the mTORC2 or CXCR3 in γδ T cells could be considered as a promising approach for γδ T cell immunotherapy against liver fibrosis.

Dual-resonance enhanced quantum light-matter interactions in deterministically coupled quantum-dot-micropillars.

Optical microcavities have widely been employed to enhance either the optical excitation or the photon emission processes for boosting light-matter interactions at the nanoscale. When both the excitation and emission processes are simultaneously facilitated by the optical resonances provided by the microcavities, as referred to the dual-resonance condition in this article, the performances of many nanophotonic devices approach to the optima. In this work, we present versatile accessing of dual-resonance conditions in deterministically coupled quantum-dot (QD)-micropillars, which enables emission from neutral exciton (X)-charged exciton (CX) transition with improved single-photon purity. In addition, the rarely observed up-converted single-photon emission process is achieved under dual-resonance conditions. We further exploit the vectorial nature of the high-order cavity modes to significantly improve the excitation efficiency under the dual-resonance condition. The dual-resonance enhanced light-matter interactions in the quantum regime provide a viable path for developing integrated quantum photonic devices based on cavity quantum electrodynamics (QED) effect, e.g., highly efficient quantum light sources and quantum logical gates.

Role of laryngopharyngeal reflux (LPR) in complications after tonsillectomy in adult patients.

BACKGROUND: Tonsillectomy and tonsillectomy with adenoidectomy are among the most common surgical procedures in otolaryngology practice, but the complications, especially the postoperative bleeding, are seriously troubling surgeons. Some authors had identified that gastroesophageal reflux and LPR are both risk factors for complications in tonsillectomy of children patients. AIMS/OBJECTIVES: Therefore, we designed this prospective study to assess the role of LPR in the development of complications following tonsillectomy in adult patients. We want to provide a basis for future clinical practice. MATERIAL AND METHODS: We recruited a totally of 150 adult patients (18-60 years old) who had an indication of tonsillectomy because of recurrent tonsillitis and divided them into two groups, the laryngopharyngeal reflux (LPR) group and the control group identified by the results of Reflux Symptom Index (RSI) and Reflux Finding Score (RFS). The complications that were observed and evaluated were pain, hemorrhage, fever, infection, and pulmonary problems. RESULT: All the patients complained of pain after surgery. The duration of the pain in the LPR group was much longer than that of the control group. In the LPR group, patients had a similar pain level on the first day after surgery. However, on the 7th day and 14th day after surgery, the pain level was obviously higher than that of the control group. We found that the body temperature mildly rose on the 1st day after surgery and gradually fell to normal level in both groups. No cases had bleeding within 24 h after surgery. There were nine cases of bleeding in the LPR group, while only one case of bleeding occurred in the control group. There were no cases of infection or pulmonary complications in either group. CONCLUSIONS AND SIGNIFICANCE: LPR is closely related to the complications followed by tonsillectomy and we also suggest that high dosages of proton pump inhibitors (PPI), alkaline water, and alginates should be prescribed to the patients with LPR during the perioperative period.

Clinical outcomes of epidural and intradural decompression for treatment of degenerative cervical myelopathy.

OBJECTIVE: This study was performed to examine the clinical outcomes of epidural and intradural decompression for degenerative cervical myelopathy. METHODS: The data for 13 patients who underwent epidural and intradural decompression for treatment of degenerative cervical myelopathy (study group) and 20 patients who underwent only cervical laminoplasty, fusion, and epidural decompression (historical control group) were retrospectively reviewed. The preoperative and postoperative neurological status was evaluated using the Japanese Orthopaedic Association (JOA) score. RESULTS: All patients' neurological symptoms were significantly improved at the final follow-up. In the study group, the patients' mean preoperative JOA score was 8.07 ± 1.80, and the final score improved by 70.88% ± 21.18%. The blood loss and operation time were significantly greater in the study group than control group. The recovery time was shorter in the study group than control group. The improvement rate was not significantly different between the two groups. CONCLUSIONS: A pia mater incision with separation of the arachnoid adhesion can significantly improve the cerebrospinal fluid flow and spinal blood flow in degenerative cervical myelopathy. Arachnoid adhesion can lead to intradural spinal scar compression. The surgical intervention described herein can achieve satisfactory neurological outcomes and shorten the recovery time.

Multilevel Lumbar Stenosis Caused by Large Tophi Involving Both Spinal Canal and Posterior Spinal Elements: A Rare Case Report and Literature Review.

Tophus is a characteristic manifestation of gout entering the chronic phase, which usually deposits in the joints of the extremities, skin mucosa, etc. A gout tophus that involves the spine causing spinal stenosis is rare and it can be misdiagnosed as a spinal tumor preoperatively. We report the case of a 35-year-old man who presented with lumbar stenosis symptoms, and suffered multiple-site gout tophi involvement throughout his body. Radiographic examinations showed that the large tophi infiltrated the posterior elements of the spine and encroached the lumbar spinal canal, resulting in neurologic compression from the second to the fifth lumbar level. Urate could be observed on a dual-energy computed tomography. A posterior-based procedure was performed to eradicate the tophi and stabilize the spine. Finally, urate crystal was confirmed by postoperative pathological examination. Here, the clinical manifestations, radiological, pathological and surgical features for this case are reported.

The Treatment of Severe Congenital Scoliosis Associated With Type I Split Cord Malformation: Is a Preliminary Bony Septum Resection Always Necessary?

BACKGROUND: Single-stage spine-shortening osteotomy without treating spinal cord malformations may have potential advantages for the treatment of severe congenital scoliosis (CS) with type I split spinal cord malformation (SSCM); however, the study of this technique was limited. OBJECTIVE: To evaluate the safety and efficacy of a single-stage spine-shortening osteotomy in the treatment of severe CS associated with type I SSCM. METHODS: A retrospective study was designed to compare 2 case series including 12 severe CS patients with type I SSCM and 26 patients with type A cord function (without spinal cord malformations, evoked potential abnormalities, and neurological dysfunctions preoperatively) treated with a single-stage spine-shortening posterior vertebral column resection (PVCR). Patient demographic, clinical, operative, and radiographic data were obtained and compared between groups. RESULTS: The surgical procedure was successfully performed in both groups, and the patients were observed for an average of 44.9 mo (range 25-78 mo) after the initial surgery. The radiographic parameters, intraoperative data, and new neurological deficits showed no difference, while deformity angular ratio (SSCM group: control group = 16.6 ± 3.6: 20.1 ± 3.9, P = .01) and corrective rate (SSCM group: control group = 50%: 58%, P = .046) of the main curve were statistically different between groups. All of the new neurological deficits were recovered within 1 yr. CONCLUSION: The single-stage spine-shortening PVCR with moderate correction could be applied to the treatment of CS associated with type I SSCM. This strategy can achieve safe spinal deformity correction while obviate the neurological complications brought by the detethering procedures, which merits further clinical investigation.

Predictive Value of Spinal Cord Function Classification and Sagittal Deformity Angular Ratio for Neurologic Risk Stratification in Patients with Severe and Stiff Kyphoscoliosis.

BACKGROUND: Three-column osteotomies were developed to treat severe spinal deformities but result in high neurologic complications and require further risk stratification. The present study investigated whether the combination of spinal cord function classification (SCFC) and deformity angular ratio (DAR) could further stratify the neurologic risks in the surgical correction of severe and stiff kyphoscoliosis. METHODS: The patients with kyphoscoliosis who had undergone posterior 3-column osteotomies at the spinal cord level were reviewed. Using our SCFC system, the preoperative neurologic function (type A, B, or C) was classified. The sagittal DAR (S-DAR), coronal, and total DARs were calculated. Intraoperative monitoring events and new neurologic deficits (NNDs) postoperatively were documented and analyzed using the SCFC and DAR or both combined. RESULTS: The NND rates increased significantly from type A to C (P = 0.000) and increased exponentially with an increase in S-DAR in types B and C but not type A. They also increased exponentially with aggravation of the SCFC in the medium and high but not low S-DAR group. All NNDs had recovered at 3 months for type A and most had recovered at 6 months for type B or C. CONCLUSIONS: The NNDs in type A SCFC usually experienced better recovery even with high S-DARs. Type B SCFC with an S-DAR >20° and type C SCFC with any S-DAR resulted in significantly greater intra- and postoperative neurologic risks. The combination of SCFC and S-DAR can further stratify the intra- and postoperative neurologic risks with these procedures.